Competition among conspecific males for fertilizing the ova is one of the mechanisms of sexual selection, i.e. selection that operates on maximizing the number of successful mating events rather than on maximizing survival and viability 1. Sperm competition represents the competition between males after copulating with the same female 2, in which their sperm are coincidental in time and space. This phenomenon has been reported in multiple species of plants and animals 3. For example, wild-caught D. melanogaster females usually contain sperm from 2-3 males 4. The sperm are stored in specialized organs with limited storage capacity, which might lead to the direct competition of the sperm from different males 2,5.
Comparing sperm competitive ability of different males of interest (experimental male types) has been performed through controlled double-mating experiments in the laboratory 6,7. Briefly, a single female is exposed to two different males consecutively, one experimental male and one cross-mating reference male. The same mating scheme is then followed using other experimental male types thus facilitating the indirect comparison of the competitive ability of their sperm through a common reference. The fraction of individuals fathered by the experimental and reference males is identified using markers, which allows one to estimate sperm competitive ability using simple mathematical expressions 7,8. In addition, sperm competitive ability can be estimated in two different scenarios depending on whether the experimental male is second or first to mate (offense and defense assay, respectively) 9, which is assumed to be reflective of different competence attributes.
Here, we describe an approach that helps to interrogate the role of different genetic factors that putatively underlie the phenomenon of sperm competitive ability in D. melanogaster.
26 Related JoVE Articles!
Community-based Adapted Tango Dancing for Individuals with Parkinson's Disease and Older Adults
Institutions: Emory University School of Medicine, Brigham and Woman‘s Hospital and Massachusetts General Hospital.
Adapted tango dancing improves mobility and balance in older adults and additional populations with balance impairments. It is composed of very simple step elements. Adapted tango involves movement initiation and cessation, multi-directional perturbations, varied speeds and rhythms. Focus on foot placement, whole body coordination, and attention to partner, path of movement, and aesthetics likely underlie adapted tango’s demonstrated efficacy for improving mobility and balance. In this paper, we describe the methodology to disseminate the adapted tango teaching methods to dance instructor trainees and to implement the adapted tango by the trainees in the community for older adults and individuals with Parkinson’s Disease (PD). Efficacy in improving mobility (measured with the Timed Up and Go, Tandem stance, Berg Balance Scale, Gait Speed and 30 sec chair stand), safety and fidelity of the program is maximized through targeted instructor and volunteer training and a structured detailed syllabus outlining class practices and progression.
Behavior, Issue 94, Dance, tango, balance, pedagogy, dissemination, exercise, older adults, Parkinson's Disease, mobility impairments, falls
Sex Stratified Neuronal Cultures to Study Ischemic Cell Death Pathways
Institutions: University of Colorado School of Medicine, Oregon Health & Science University, University of Colorado School of Medicine.
Sex differences in neuronal susceptibility to ischemic injury and neurodegenerative disease have long been observed, but the signaling mechanisms responsible for those differences remain unclear. Primary disassociated embryonic neuronal culture provides a simplified experimental model with which to investigate the neuronal cell signaling involved in cell death as a result of ischemia or disease; however, most neuronal cultures used in research today are mixed sex. Researchers can and do test the effects of sex steroid treatment in mixed sex neuronal cultures in models of neuronal injury and disease, but accumulating evidence suggests that the female brain responds to androgens, estrogens, and progesterone differently than the male brain. Furthermore, neonate male and female rodents respond differently to ischemic injury, with males experiencing greater injury following cerebral ischemia than females. Thus, mixed sex neuronal cultures might obscure and confound the experimental results; important information might be missed. For this reason, the Herson Lab at the University of Colorado School of Medicine routinely prepares sex-stratified primary disassociated embryonic neuronal cultures from both hippocampus and cortex. Embryos are sexed before harvesting of brain tissue and male and female tissue are disassociated separately, plated separately, and maintained separately. Using this method, the Herson Lab has demonstrated a male-specific role for the ion channel TRPM2 in ischemic cell death. In this manuscript, we share and discuss our protocol for sexing embryonic mice and preparing sex-stratified hippocampal primary disassociated neuron cultures. This method can be adapted to prepare sex-stratified cortical cultures and the method for embryo sexing can be used in conjunction with other protocols for any study in which sex is thought to be an important determinant of outcome.
Neuroscience, Issue 82, male, female, sex, neuronal culture, ischemia, cell death, neuroprotection
Transabdominal Ultrasound for Pregnancy Diagnosis in Reeves' Muntjac Deer
Institutions: Colorado State University.
Reeves' muntjac deer (Muntiacus reevesi
) are a small cervid species native to southeast Asia, and are currently being investigated as a potential model of prion disease transmission and pathogenesis. Vertical transmission is an area of interest among researchers studying infectious diseases, including prion disease, and these investigations require efficient methods for evaluating the effects of maternal infection on reproductive performance. Ultrasonographic examination is a well-established tool for diagnosing pregnancy and assessing fetal health in many animal species1-7
, including several species of farmed cervids8-19
, however this technique has not been described in Reeves' muntjac deer. Here we describe the application of transabdominal ultrasound to detect pregnancy in muntjac does and to evaluate fetal growth and development throughout the gestational period. Using this procedure, pregnant animals were identified as early as 35 days following doe-buck pairing and this was an effective means to safely monitor the pregnancy at regular intervals. Future goals of this work will include establishing normal fetal measurement references for estimation of gestational age, determining sensitivity and specificity of the technique for diagnosing pregnancy at various stages of gestation, and identifying variations in fetal growth and development under different experimental conditions.
Medicine, Issue 83, Ultrasound, Reeves' muntjac deer, Muntiacus reevesi, fetal development, fetal growth, captive cervids
Automated, Quantitative Cognitive/Behavioral Screening of Mice: For Genetics, Pharmacology, Animal Cognition and Undergraduate Instruction
Institutions: Rutgers University, Koç University, New York University, Fairfield University.
We describe a high-throughput, high-volume, fully automated, live-in 24/7 behavioral testing system for assessing the effects of genetic and pharmacological manipulations on basic mechanisms of cognition and learning in mice. A standard polypropylene mouse housing tub is connected through an acrylic tube to a standard commercial mouse test box. The test box has 3 hoppers, 2 of which are connected to pellet feeders. All are internally illuminable with an LED and monitored for head entries by infrared (IR) beams. Mice live in the environment, which eliminates handling during screening. They obtain their food during two or more daily feeding periods by performing in operant (instrumental) and Pavlovian (classical) protocols, for which we have written protocol-control software and quasi-real-time data analysis and graphing software. The data analysis and graphing routines are written in a MATLAB-based language created to simplify greatly the analysis of large time-stamped behavioral and physiological event records and to preserve a full data trail from raw data through all intermediate analyses to the published graphs and statistics within a single data structure. The data-analysis code harvests the data several times a day and subjects it to statistical and graphical analyses, which are automatically stored in the "cloud" and on in-lab computers. Thus, the progress of individual mice is visualized and quantified daily. The data-analysis code talks to the protocol-control code, permitting the automated advance from protocol to protocol of individual subjects. The behavioral protocols implemented are matching, autoshaping, timed hopper-switching, risk assessment in timed hopper-switching, impulsivity measurement, and the circadian anticipation of food availability. Open-source protocol-control and data-analysis code makes the addition of new protocols simple. Eight test environments fit in a 48 in x 24 in x 78 in cabinet; two such cabinets (16 environments) may be controlled by one computer.
Behavior, Issue 84, genetics, cognitive mechanisms, behavioral screening, learning, memory, timing
Barnes Maze Testing Strategies with Small and Large Rodent Models
Institutions: University of Missouri, Food and Drug Administration.
Spatial learning and memory of laboratory rodents is often assessed via navigational ability in mazes, most popular of which are the water and dry-land (Barnes) mazes. Improved performance over sessions or trials is thought to reflect learning and memory of the escape cage/platform location. Considered less stressful than water mazes, the Barnes maze is a relatively simple design of a circular platform top with several holes equally spaced around the perimeter edge. All but one of the holes are false-bottomed or blind-ending, while one leads to an escape cage. Mildly aversive stimuli (e.g.
bright overhead lights) provide motivation to locate the escape cage. Latency to locate the escape cage can be measured during the session; however, additional endpoints typically require video recording. From those video recordings, use of automated tracking software can generate a variety of endpoints that are similar to those produced in water mazes (e.g.
distance traveled, velocity/speed, time spent in the correct quadrant, time spent moving/resting, and confirmation of latency). Type of search strategy (i.e.
random, serial, or direct) can be categorized as well. Barnes maze construction and testing methodologies can differ for small rodents, such as mice, and large rodents, such as rats. For example, while extra-maze cues are effective for rats, smaller wild rodents may require intra-maze cues with a visual barrier around the maze. Appropriate stimuli must be identified which motivate the rodent to locate the escape cage. Both Barnes and water mazes can be time consuming as 4-7 test trials are typically required to detect improved learning and memory performance (e.g.
shorter latencies or path lengths to locate the escape platform or cage) and/or differences between experimental groups. Even so, the Barnes maze is a widely employed behavioral assessment measuring spatial navigational abilities and their potential disruption by genetic, neurobehavioral manipulations, or drug/ toxicant exposure.
Behavior, Issue 84, spatial navigation, rats, Peromyscus, mice, intra- and extra-maze cues, learning, memory, latency, search strategy, escape motivation
A Restriction Enzyme Based Cloning Method to Assess the In vitro Replication Capacity of HIV-1 Subtype C Gag-MJ4 Chimeric Viruses
Institutions: Emory University, Emory University.
The protective effect of many HLA class I alleles on HIV-1 pathogenesis and disease progression is, in part, attributed to their ability to target conserved portions of the HIV-1 genome that escape with difficulty. Sequence changes attributed to cellular immune pressure arise across the genome during infection, and if found within conserved regions of the genome such as Gag, can affect the ability of the virus to replicate in vitro
. Transmission of HLA-linked polymorphisms in Gag to HLA-mismatched recipients has been associated with reduced set point viral loads. We hypothesized this may be due to a reduced replication capacity of the virus. Here we present a novel method for assessing the in vitro
replication of HIV-1 as influenced by the gag
gene isolated from acute time points from subtype C infected Zambians. This method uses restriction enzyme based cloning to insert the gag
gene into a common subtype C HIV-1 proviral backbone, MJ4. This makes it more appropriate to the study of subtype C sequences than previous recombination based methods that have assessed the in vitro
replication of chronically derived gag-pro
sequences. Nevertheless, the protocol could be readily modified for studies of viruses from other subtypes. Moreover, this protocol details a robust and reproducible method for assessing the replication capacity of the Gag-MJ4 chimeric viruses on a CEM-based T cell line. This method was utilized for the study of Gag-MJ4 chimeric viruses derived from 149 subtype C acutely infected Zambians, and has allowed for the identification of residues in Gag that affect replication. More importantly, the implementation of this technique has facilitated a deeper understanding of how viral replication defines parameters of early HIV-1 pathogenesis such as set point viral load and longitudinal CD4+ T cell decline.
Infectious Diseases, Issue 90, HIV-1, Gag, viral replication, replication capacity, viral fitness, MJ4, CEM, GXR25
The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism
Institutions: University of Montréal, McGill University, University of Minnesota.
Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of neurological and psychiatric disorders such as stroke and depression. Yet, the mechanisms underlying its ability to modulate brain excitability to improve clinical symptoms remains poorly understood 33
. To help improve this understanding, proton magnetic resonance spectroscopy (1
H-MRS) can be used as it allows the in vivo
quantification of brain metabolites such as γ-aminobutyric acid (GABA) and glutamate in a region-specific manner 41
. In fact, a recent study demonstrated that 1
H-MRS is indeed a powerful means to better understand the effects of tDCS on neurotransmitter concentration 34
. This article aims to describe the complete protocol for combining tDCS (NeuroConn MR compatible stimulator) with 1
H-MRS at 3 T using a MEGA-PRESS sequence. We will describe the impact of a protocol that has shown great promise for the treatment of motor dysfunctions after stroke, which consists of bilateral stimulation of primary motor cortices 27,30,31
. Methodological factors to consider and possible modifications to the protocol are also discussed.
Neuroscience, Issue 93, proton magnetic resonance spectroscopy, transcranial direct current stimulation, primary motor cortex, GABA, glutamate, stroke
Effect of Male Accessory Gland Products on Egg Laying in Gastropod Molluscs
Institutions: VU University.
In internally fertilizing animals, seminal fluid is usually added to the spermatozoa, together forming the semen or ejaculate. Besides nourishing and activating sperm, the components in the seminal fluid can also influence female physiology to augment fertilization success of the sperm donor. While many studies have reported such effects in species with separate sexes, few studies have addressed this in simultaneously hermaphroditic animals. This video protocol presents a method to study effects of seminal fluid in gastropods, using a simultaneously hermaphroditic freshwater snail, the great pond snail Lymnaea stagnalis
, as model organism. While the procedure is shown using complete prostate gland extracts, individual components (i.e.
, proteins, peptides, and other compounds) of the seminal fluid can be tested in the same way. Effects of the receipt of ejaculate components on egg laying can be quantified in terms of frequency of egg laying and more subtle estimates of female reproductive performance such as egg numbers within each egg masses. Results show that seminal fluid proteins affect female reproductive output in this simultaneous hermaphrodite, highlighting their importance for sexual selection.
Physiology, Issue 88, Allohormone, Fresh-water snail, Gastropod, Lymnaea stagnalis, Mollusc, Pond snail, Prostate, Semen, Seminal fluid Sexual selection, Sperm
Production of Haploid Zebrafish Embryos by In Vitro Fertilization
Institutions: University of Notre Dame.
The zebrafish has become a mainstream vertebrate model that is relevant for many disciplines of scientific study. Zebrafish are especially well suited for forward genetic analysis of developmental processes due to their external fertilization, embryonic size, rapid ontogeny, and optical clarity – a constellation of traits that enable the direct observation of events ranging from gastrulation to organogenesis with a basic stereomicroscope. Further, zebrafish embryos can survive for several days in the haploid state. The production of haploid embryos in vitro
is a powerful tool for mutational analysis, as it enables the identification of recessive mutant alleles present in first generation (F1) female carriers following mutagenesis in the parental (P) generation. This approach eliminates the necessity to raise multiple generations (F2, F3, etc.
) which involves breeding of mutant families, thus saving the researcher time along with reducing the needs for zebrafish colony space, labor, and the husbandry costs. Although zebrafish have been used to conduct forward screens for the past several decades, there has been a steady expansion of transgenic and genome editing tools. These tools now offer a plethora of ways to create nuanced assays for next generation screens that can be used to further dissect the gene regulatory networks that drive vertebrate ontogeny. Here, we describe how to prepare haploid zebrafish embryos. This protocol can be implemented for novel future haploid screens, such as in enhancer and suppressor screens, to address the mechanisms of development for a broad number of processes and tissues that form during early embryonic stages.
Developmental Biology, Issue 89, zebrafish, haploid, in vitro fertilization, forward genetic screen, saturation, recessive mutation, mutagenesis
Cell Surface Marker Mediated Purification of iPS Cell Intermediates from a Reprogrammable Mouse Model
Institutions: Monash University, Monash University.
Mature cells can be reprogrammed to a pluripotent state. These so called induced pluripotent stem (iPS) cells are able to give rise to all cell types of the body and consequently have vast potential for regenerative medicine applications. Traditionally iPS cells are generated by viral introduction of transcription factors Oct-4, Klf-4, Sox-2, and c-Myc (OKSM) into fibroblasts. However, reprogramming is an inefficient process with only 0.1-1% of cells reverting towards a pluripotent state, making it difficult to study the reprogramming mechanism. A proven methodology that has allowed the study of the reprogramming process is to separate the rare intermediates of the reaction from the refractory bulk population. In the case of mouse embryonic fibroblasts (MEFs), we and others have previously shown that reprogramming cells undergo a distinct series of changes in the expression profile of cell surface markers which can be used for the separation of these cells. During the early stages of OKSM expression successfully reprogramming cells lose fibroblast identity marker Thy-1.2 and up-regulate pluripotency associated marker Ssea-1. The final transition of a subset of Ssea-1 positive cells towards the pluripotent state is marked by the expression of Epcam during the late stages of reprogramming. Here we provide a detailed description of the methodology used to isolate reprogramming intermediates from cultures of reprogramming MEFs. In order to increase experimental reproducibility we use a reprogrammable mouse strain that has been engineered to express a transcriptional transactivator (m2rtTA) under control of the Rosa26 locus and OKSM under control of a doxycycline responsive promoter. Cells isolated from these mice are isogenic and express OKSM homogenously upon addition of doxycycline. We describe in detail the establishment of the reprogrammable mice, the derivation of MEFs, and the subsequent isolation of intermediates during reprogramming into iPS cells via fluorescent activated cells sorting (FACS).
Stem Cell Biology, Issue 91, Induced pluripotent stem cells; reprogramming; intermediates; fluorescent activated cells sorting; cell surface marker; reprogrammable mouse model; derivation of mouse embryonic fibroblasts
Determination of Protein-ligand Interactions Using Differential Scanning Fluorimetry
Institutions: University of Exeter.
A wide range of methods are currently available for determining the dissociation constant between a protein and interacting small molecules. However, most of these require access to specialist equipment, and often require a degree of expertise to effectively establish reliable experiments and analyze data. Differential scanning fluorimetry (DSF) is being increasingly used as a robust method for initial screening of proteins for interacting small molecules, either for identifying physiological partners or for hit discovery. This technique has the advantage that it requires only a PCR machine suitable for quantitative PCR, and so suitable instrumentation is available in most institutions; an excellent range of protocols are already available; and there are strong precedents in the literature for multiple uses of the method. Past work has proposed several means of calculating dissociation constants from DSF data, but these are mathematically demanding. Here, we demonstrate a method for estimating dissociation constants from a moderate amount of DSF experimental data. These data can typically be collected and analyzed within a single day. We demonstrate how different models can be used to fit data collected from simple binding events, and where cooperative binding or independent binding sites are present. Finally, we present an example of data analysis in a case where standard models do not apply. These methods are illustrated with data collected on commercially available control proteins, and two proteins from our research program. Overall, our method provides a straightforward way for researchers to rapidly gain further insight into protein-ligand interactions using DSF.
Biophysics, Issue 91, differential scanning fluorimetry, dissociation constant, protein-ligand interactions, StepOne, cooperativity, WcbI.
The Utility of Stage-specific Mid-to-late Drosophila Follicle Isolation
Institutions: University of Iowa Carver College of Medicine.
oogenesis or follicle development has been widely used to advance the understanding of complex developmental and cell biologic processes. This methods paper describes how to isolate mid-to-late stage follicles (Stage 10B-14) and utilize them to provide new insights into the molecular and morphologic events occurring during tight windows of developmental time. Isolated follicles can be used for a variety of experimental techniques, including in vitro
development assays, live imaging, mRNA expression analysis and western blot analysis of proteins. Follicles at Stage 10B (S10B) or later will complete development in culture; this allows one to combine genetic or pharmacologic perturbations with in vitro
development to define the effects of such manipulations on the processes occurring during specific periods of development. Additionally, because these follicles develop in culture, they are ideally suited for live imaging studies, which often reveal new mechanisms that mediate morphological events. Isolated follicles can also be used for molecular analyses. For example, changes in gene expression that result from genetic perturbations can be defined for specific developmental windows. Additionally, protein level, stability, and/or posttranslational modification state during a particular stage of follicle development can be examined through western blot analyses. Thus, stage-specific isolation of Drosophila
follicles provides a rich source of information into widely conserved processes of development and morphogenesis.
Developmental Biology, Issue 82, Drosophila melanogaster, Organ Culture Techniques, Gene Expression Profiling, Microscopy, Confocal, Cell Biology, Genetic Research, Molecular Biology, Pharmacology, Drosophila, oogenesis, follicle, live-imaging, gene expression, development
Acquiring Fluorescence Time-lapse Movies of Budding Yeast and Analyzing Single-cell Dynamics using GRAFTS
Institutions: Massachusetts Institute of Technology.
Fluorescence time-lapse microscopy has become a powerful tool in the study of many biological processes at the single-cell level. In particular, movies depicting the temporal dependence of gene expression provide insight into the dynamics of its regulation; however, there are many technical challenges to obtaining and analyzing fluorescence movies of single cells. We describe here a simple protocol using a commercially available microfluidic culture device to generate such data, and a MATLAB-based, graphical user interface (GUI) -based software package to quantify the fluorescence images. The software segments and tracks cells, enables the user to visually curate errors in the data, and automatically assigns lineage and division times. The GUI further analyzes the time series to produce whole cell traces as well as their first and second time derivatives. While the software was designed for S. cerevisiae
, its modularity and versatility should allow it to serve as a platform for studying other cell types with few modifications.
Microbiology, Issue 77, Cellular Biology, Molecular Biology, Genetics, Biophysics, Saccharomyces cerevisiae, Microscopy, Fluorescence, Cell Biology, microscopy/fluorescence and time-lapse, budding yeast, gene expression dynamics, segmentation, lineage tracking, image tracking, software, yeast, cells, imaging
Perceptual and Category Processing of the Uncanny Valley Hypothesis' Dimension of Human Likeness: Some Methodological Issues
Institutions: University of Zurich.
Mori's Uncanny Valley Hypothesis1,2
proposes that the perception of humanlike characters such as robots and, by extension, avatars (computer-generated characters) can evoke negative or positive affect (valence) depending on the object's degree of visual and behavioral realism along a dimension of human likeness
) (Figure 1
). But studies of affective valence of subjective responses to variously realistic non-human characters have produced inconsistent findings 3, 4, 5, 6
. One of a number of reasons for this is that human likeness is not perceived as the hypothesis assumes. While the DHL can be defined following Mori's description as a smooth linear change in the degree of physical humanlike similarity, subjective perception of objects along the DHL can be understood in terms of the psychological effects of categorical perception (CP) 7
. Further behavioral and neuroimaging investigations of category processing and CP along the DHL and of the potential influence of the dimension's underlying category structure on affective experience are needed. This protocol therefore focuses on the DHL and allows examination of CP. Based on the protocol presented in the video as an example, issues surrounding the methodology in the protocol and the use in "uncanny" research of stimuli drawn from morph continua to represent the DHL are discussed in the article that accompanies the video. The use of neuroimaging and morph stimuli to represent the DHL in order to disentangle brain regions neurally responsive to physical human-like similarity from those responsive to category change and category processing is briefly illustrated.
Behavior, Issue 76, Neuroscience, Neurobiology, Molecular Biology, Psychology, Neuropsychology, uncanny valley, functional magnetic resonance imaging, fMRI, categorical perception, virtual reality, avatar, human likeness, Mori, uncanny valley hypothesis, perception, magnetic resonance imaging, MRI, imaging, clinical techniques
Surgical Management of Meatal Stenosis with Meatoplasty
Institutions: Johns Hopkins School of Medicine.
Meatal stenosis is a common urologic complication after circumcision. Children present to their primary care physicians with complaints of deviated urinary stream, difficult-to-aim, painful urination, and urinary frequency. Clinical exam reveals a pinpoint meatus and if the child is asked to urinate, he will usually have an upward, thin, occasionally forceful urinary stream with incomplete bladder emptying. The mainstay of management is meatoplasty (reconstruction of the distal urethra /meatus). This educational video will demonstrate how this is performed.
Medicine, Issue 45, Urinary obstruction, pediatric urology, deviated urinary stream, meatal stenosis, operative repair, meatotomy, meatoplasty
Isolation of Fidelity Variants of RNA Viruses and Characterization of Virus Mutation Frequency
Institutions: Institut Pasteur .
RNA viruses use RNA dependent RNA polymerases to replicate their genomes. The intrinsically high error rate of these enzymes is a large contributor to the generation of extreme population diversity that facilitates virus adaptation and evolution. Increasing evidence shows that the intrinsic error rates, and the resulting mutation frequencies, of RNA viruses can be modulated by subtle amino acid changes to the viral polymerase. Although biochemical assays exist for some viral RNA polymerases that permit quantitative measure of incorporation fidelity, here we describe a simple method of measuring mutation frequencies of RNA viruses that has proven to be as accurate as biochemical approaches in identifying fidelity altering mutations. The approach uses conventional virological and sequencing techniques that can be performed in most biology laboratories. Based on our experience with a number of different viruses, we have identified the key steps that must be optimized to increase the likelihood of isolating fidelity variants and generating data of statistical significance. The isolation and characterization of fidelity altering mutations can provide new insights into polymerase structure and function1-3
. Furthermore, these fidelity variants can be useful tools in characterizing mechanisms of virus adaptation and evolution4-7
Immunology, Issue 52, Polymerase fidelity, RNA virus, mutation frequency, mutagen, RNA polymerase, viral evolution
Experimental Manipulation of Body Size to Estimate Morphological Scaling Relationships in Drosophila
Institutions: University of Houston, Michigan State University.
The scaling of body parts is a central feature of animal morphology1-7
. Within species, morphological traits need to be correctly proportioned to the body for the organism to function; larger individuals typically have larger body parts and smaller individuals generally have smaller body parts, such that overall body shape is maintained across a range of adult body sizes. The requirement for correct proportions means that individuals within species usually exhibit low variation in relative trait size. In contrast, relative trait size can vary dramatically among species and is a primary mechanism by which morphological diversity is produced. Over a century of comparative work has established these intra- and interspecific patterns3,4
Perhaps the most widely used approach to describe this variation is to calculate the scaling relationship between the size of two morphological traits using the allometric equation y=bxα, where x and y are the size of the two traits, such as organ and body size8,9
. This equation describes the within-group (e.g., species, population) scaling relationship between two traits as both vary in size. Log-transformation of this equation produces a simple linear equation, log(y) = log(b) + αlog(x) and log-log plots of the size of different traits among individuals of the same species typically reveal linear scaling with an intercept of log(b) and a slope of α, called the 'allometric coefficient'9,10
. Morphological variation among groups is described by differences in scaling relationship intercepts or slopes for a given trait pair. Consequently, variation in the parameters of the allometric equation (b and α) elegantly describes the shape variation captured in the relationship between organ and body size within and among biological groups (see 11,12
Not all traits scale linearly with each other or with body size (e.g., 13,14
) Hence, morphological scaling relationships are most informative when the data are taken from the full range of trait sizes. Here we describe how simple experimental manipulation of diet can be used to produce the full range of body size in insects. This permits an estimation of the full scaling relationship for any given pair of traits, allowing a complete description of how shape covaries with size and a robust comparison of scaling relationship parameters among biological groups. Although we focus on Drosophila
, our methodology should be applicable to nearly any fully metamorphic insect.
Developmental Biology, Issue 56, Drosophila, allometry, morphology, body size, scaling, insect
Using a Comparative Species Approach to Investigate the Neurobiology of Paternal Responses
Institutions: Randolph-Macon College, Marshall University.
A goal of behavioral neuroscience is to identify underlying neurobiological factors that regulate specific behaviors. Using animal models to accomplish this goal, many methodological strategies require invasive techniques to manipulate the intensity of the behavior of interest (e.g., lesion methods, pharmacological manipulations, microdialysis techniques, genetically-engineered animal models). The utilization of a comparative species approach allows researchers to take advantage of naturally occurring differences in response strategies existing in closely related species. In our lab, we use two species of the Peromyscus
genus that differ in paternal responses. The male California deer mouse (Peromyscus californicus
) exhibits the same parental responses as the female whereas its cousin, the common deer mouse (Peromyscus maniculatus
) exhibits virtually no nurturing/parental responses in the presence of pups. Of specific interest in this article is an exploration of the neurobiological factors associated with the affiliative social responses exhibited by the paternal California deer mouse. Because the behavioral neuroscience approach is multifaceted, the following key components of the study will be briefly addressed: the identification of appropriate species for this type of research; data collection for behavioral analysis; preparation and sectioning of the brains; basic steps involved in immunocytochemistry for the quantification of vasopressin-immunoreactivity; the use of neuroimaging software to quantify the brain tissue; the use of a microsequencing video analysis to score behavior and, finally, the appropriate statistical analyses to provide the most informed interpretations of the research findings.
Neuroscience, Issue 55, Peromyscus, mouse, paternal behavior, vasopressin, immunocytochemistry, microsequencing behavioral analysis
Mass Production of Genetically Modified Aedes aegypti for Field Releases in Brazil
Institutions: Oxitec Ltd, Universidade de São Paulo, Universidade de São Paulo, Moscamed Brasil, University of Oxford, Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM).
New techniques and methods are being sought to try to win the battle against mosquitoes. Recent advances in molecular techniques have led to the development of new and innovative methods of mosquito control based around the Sterile Insect Technique (SIT)1-3
. A control method known as RIDL (Release of Insects carrying a Dominant Lethal)4
, is based around SIT, but uses genetic methods to remove the need for radiation-sterilization5-8
. A RIDL strain of Ae. aegypti
was successfully tested in the field in Grand Cayman9,10
; further field use is planned or in progress in other countries around the world.
Mass rearing of insects has been established in several insect species and to levels of billions a week. However, in mosquitoes, rearing has generally been performed on a much smaller scale, with most large scale rearing being performed in the 1970s and 80s. For a RIDL program it is desirable to release as few females as possible as they bite and transmit disease. In a mass rearing program there are several stages to produce the males to be released: egg production, rearing eggs until pupation, and then sorting males from females before release. These males are then used for a RIDL control program, released as either pupae or adults11,12
To suppress a mosquito population using RIDL a large number of high quality male adults need to be reared13,14
. The following describes the methods for the mass rearing of OX513A, a RIDL strain of Ae. aegypti 8,
for release and covers the techniques required for the production of eggs and mass rearing RIDL males for a control program.
Basic Protocol, Issue 83, Aedes aegypti, mass rearing, population suppression, transgenic, insect, mosquito, dengue
Intraductal Injection of LPS as a Mouse Model of Mastitis: Signaling Visualized via an NF-κB Reporter Transgenic
Institutions: Vanderbilt University Medical Center, Vanderbilt University Medical Center, University of Hawaii at Hilo College of Pharmacy.
Animal models of human disease are necessary in order to rigorously study stages of disease progression and associated mechanisms, and ultimately, as pre-clinical models to test interventions. In these methods, we describe a technique in which lipopolysaccharide (LPS) is injected into the lactating mouse mammary gland via the nipple, effectively modeling mastitis, or inflammation, of the gland. This simulated infection results in increased nuclear factor kappa B (NF-κB) signaling, as visualized through bioluminescent imaging of an NF-κB luciferase reporter mouse1
Our ultimate goal in developing these methods was to study the inflammation associated with mastitis in the lactating gland, which often includes redness, swelling, and immune cell infiltration2,3
. Therefore, we were keenly aware that incision or any type of wounding of the skin, the nipple, or the gland in order to introduce the LPS could not be utilized in our methods since the approach would likely confound the read-out of inflammation. We also desired a straight-forward method that did not require specially made hand-drawn pipettes or the use of micromanipulators to hold these specialized tools in place. Thus, we determined to use a commercially available insulin syringe and to inject the agent into the mammary duct of an intact nipple. This method was successful and allowed us to study the inflammation associated with LPS injection without any additional effects overlaid by the process of injection. In addition, this method also utilized an NF-κB luciferase reporter transgenic mouse and bioluminescent imaging technology to visually and quantitatively show increased NF-κB signaling within the LPS-injected gland4
These methods are of interest to researchers of many disciplines who wish to model disease within the lactating mammary gland, as ultimately, the technique described here could be utilized for injection of a number of substances, and is not limited to only LPS.
Medicine, Issue 67, mastitis, intraductal injection, NF-kappaB, reporter transgenic, LPS, bioluminescent imaging, lactation
Regular Care and Maintenance of a Zebrafish (Danio rerio) Laboratory: An Introduction
Institutions: Edith Cowan University, Graylands Hospital, University of Western Australia, McCusker Alzheimer's Research foundation, University of Western Australia , University of Adelaide, Curtin University of Technology, University of Western Australia .
This protocol describes regular care and maintenance of a zebrafish laboratory. Zebrafish are now gaining popularity in genetics, pharmacological and behavioural research. As a vertebrate, zebrafish share considerable genetic sequence similarity with humans and are being used as an animal model for various human disease conditions. The advantages of zebrafish in comparison to other common vertebrate models include high fecundity, low maintenance cost, transparent embryos, and rapid development. Due to the spur of interest in zebrafish research, the need to establish and maintain a productive zebrafish housing facility is also increasing. Although literature is available for the maintenance of a zebrafish laboratory, a concise video protocol is lacking. This video illustrates the protocol for regular housing, feeding, breeding and raising of zebrafish larvae. This process will help researchers to understand the natural behaviour and optimal conditions of zebrafish husbandry and hence troubleshoot experimental issues that originate from the fish husbandry conditions. This protocol will be of immense help to researchers planning to establish a zebrafish laboratory, and also to graduate students who are intending to use zebrafish as an animal model.
Basic Protocols, Issue 69, Biology, Marine Biology, Zebrafish, Danio rerio, maintenance, breeding, feeding, raising, larvae, animal model, aquarium
Peering into the Dynamics of Social Interactions: Measuring Play Fighting in Rats
Institutions: University of Lethbridge.
Play fighting in the rat involves attack and defense of the nape of the neck, which if contacted, is gently nuzzled with the snout. Because the movements of one animal are countered by the actions of its partner, play fighting is a complex, dynamic interaction. This dynamic complexity raises methodological problems about what to score for experimental studies. We present a scoring schema that is sensitive to the correlated nature of the actions performed. The frequency of play fighting can be measured by counting the number of playful nape attacks occurring per unit time. However, playful defense, as it can only occur in response to attack, is necessarily a contingent measure that is best measured as a percentage (#attacks defended/total # attacks X 100%). How a particular attack is defended against can involve one of several tactics, and these are contingent on defense having taken place; consequently, the type of defense is also best expressed contingently as a percentage. Two experiments illustrate how these measurements can be used to detect the effect of brain damage on play fighting even when there is no effect on overall playfulness. That is, the schema presented here is designed to detect and evaluate changes in the content
of play following an experimental treatment.
Neuroscience, Issue 71, Neurobiology, Behavior, Psychology, Anatomy, Physiology, Medicine, Play behavior, play, fighting, wrestling, grooming, allogrooming, social interaction, rat, behavioral analysis, animal model
A Strategy to Identify de Novo Mutations in Common Disorders such as Autism and Schizophrenia
Institutions: Universite de Montreal, Universite de Montreal, Universite de Montreal.
There are several lines of evidence supporting the role of de novo
mutations as a mechanism for common disorders, such as autism and schizophrenia. First, the de novo
mutation rate in humans is relatively high, so new mutations are generated at a high frequency in the population. However, de novo
mutations have not been reported in most common diseases. Mutations in genes leading to severe diseases where there is a strong negative selection against the phenotype, such as lethality in embryonic stages or reduced reproductive fitness, will not be transmitted to multiple family members, and therefore will not be detected by linkage gene mapping or association studies. The observation of very high concordance in monozygotic twins and very low concordance in dizygotic twins also strongly supports the hypothesis that a significant fraction of cases may result from new mutations. Such is the case for diseases such as autism and schizophrenia. Second, despite reduced reproductive fitness1
and extremely variable environmental factors, the incidence of some diseases is maintained worldwide at a relatively high and constant rate. This is the case for autism and schizophrenia, with an incidence of approximately 1% worldwide. Mutational load can be thought of as a balance between selection for or against a deleterious mutation and its production by de novo
mutation. Lower rates of reproduction constitute a negative selection factor that should reduce the number of mutant alleles in the population, ultimately leading to decreased disease prevalence. These selective pressures tend to be of different intensity in different environments. Nonetheless, these severe mental disorders have been maintained at a constant relatively high prevalence in the worldwide population across a wide range of cultures and countries despite a strong negative selection against them2
. This is not what one would predict in diseases with reduced reproductive fitness, unless there was a high new mutation rate. Finally, the effects of paternal age: there is a significantly increased risk of the disease with increasing paternal age, which could result from the age related increase in paternal de novo
mutations. This is the case for autism and schizophrenia3
. The male-to-female ratio of mutation rate is estimated at about 4–6:1, presumably due to a higher number of germ-cell divisions with age in males. Therefore, one would predict that de novo
mutations would more frequently come from males, particularly older males4
. A high rate of new mutations may in part explain why genetic studies have so far failed to identify many genes predisposing to complexes diseases genes, such as autism and schizophrenia, and why diseases have been identified for a mere 3% of genes in the human genome. Identification for de novo
mutations as a cause of a disease requires a targeted molecular approach, which includes studying parents and affected subjects. The process for determining if the genetic basis of a disease may result in part from de novo
mutations and the molecular approach to establish this link will be illustrated, using autism and schizophrenia as examples.
Medicine, Issue 52, de novo mutation, complex diseases, schizophrenia, autism, rare variations, DNA sequencing
Using Visual and Narrative Methods to Achieve Fair Process in Clinical Care
Institutions: Brandeis University, Brandeis University.
The Institute of Medicine has targeted patient-centeredness as an important area of quality improvement. A major dimension of patient-centeredness is respect for patient's values, preferences, and expressed needs. Yet specific approaches to gaining this understanding and translating it to quality care in the clinical setting are lacking. From a patient perspective quality is not a simple concept but is best understood in terms of five dimensions: technical outcomes; decision-making efficiency; amenities and convenience; information and emotional support; and overall patient satisfaction. Failure to consider quality from this five-pronged perspective results in a focus on medical outcomes, without considering the processes central to quality from the patient's perspective and vital to achieving good outcomes. In this paper, we argue for applying the concept of fair process in clinical settings. Fair process involves using a collaborative approach to exploring diagnostic issues and treatments with patients, explaining the rationale for decisions, setting expectations about roles and responsibilities, and implementing a core plan and ongoing evaluation. Fair process opens the door to bringing patient expertise into the clinical setting and the work of developing health care goals and strategies. This paper provides a step by step illustration of an innovative visual approach, called photovoice or photo-elicitation, to achieve fair process in clinical work with acquired brain injury survivors and others living with chronic health conditions. Applying this visual tool and methodology in the clinical setting will enhance patient-provider communication; engage patients as partners in identifying challenges, strengths, goals, and strategies; and support evaluation of progress over time. Asking patients to bring visuals of their lives into the clinical interaction can help to illuminate gaps in clinical knowledge, forge better therapeutic relationships with patients living with chronic conditions such as brain injury, and identify patient-centered goals and possibilities for healing. The process illustrated here can be used by clinicians, (primary care physicians, rehabilitation therapists, neurologists, neuropsychologists, psychologists, and others) working with people living with chronic conditions such as acquired brain injury, mental illness, physical disabilities, HIV/AIDS, substance abuse, or post-traumatic stress, and by leaders of support groups for the types of patients described above and their family members or caregivers.
Medicine, Issue 48, person-centered care, participatory visual methods, photovoice, photo-elicitation, narrative medicine, acquired brain injury, disability, rehabilitation, palliative care
Interview: Bioreactors and Surfaced-Modified 3D-Scaffolds for Stem Cell Research
Institutions: Karlsruhe Institute of Technology.
A Nature Editorial in 2003 asked the question "Good-bye, flat biology?" What does this question imply? In the past, many in vitro culture systems, mainly monolayer cultures, often suffered from the disadvantage that differentiated primary cells had a relatively short life-span and de-differentiated during culture. As a consequence, most of their organ-specific functions were lost rapidly. Thus, in order to reproduce better conditions for these cells in vitro, modifications and adaptations have been made to conventional monolayer cultures.
The last generation of CellChips -- micro-thermoformed containers -- a specific technology was developed, which offers the additional possibility to modify the whole surface of the 3D formed containers. This allows a surface-patterning on a submicron scale with distinct signalling molecules. Sensors and signal electrodes may be incorporated. Applications range from basic research in cell biology to toxicology and pharmacology. Using biodegradable polymers, clinical applications become a possibility. Furthermore, the last generation of micro-thermoformed chips has been optimized to allow for cheap mass production.
Cellular Biology, Issue 15, Interview, bioreactors, cell culture systems, 3D cell culture, stem cells
Interview: Protein Folding and Studies of Neurodegenerative Diseases
Institutions: MIT - Massachusetts Institute of Technology.
In this interview, Dr. Lindquist describes relationships between protein folding, prion diseases and neurodegenerative disorders. The problem of the protein folding is at the core of the modern biology. In addition to their traditional biochemical functions, proteins can mediate transfer of biological information and therefore can be considered a genetic material. This recently discovered function of proteins has important implications for studies of human disorders. Dr. Lindquist also describes current experimental approaches to investigate the mechanism of neurodegenerative diseases based on genetic studies in model organisms.
Neuroscience, issue 17, protein folding, brain, neuron, prion, neurodegenerative disease, yeast, screen, Translational Research


Any angler worth their salt can tell you the importance of healthy habitats for fish and wildlife. This project, conducted by researchers from the University of Florida and the Florida Fish and Wildlife Conservation Commission, evaluated how commercially and recreationally important sportfish like snook and tarpon have responded to decades of habitat restoration activities in Tampa Bay. Quarterly fish sampling and habitat assessments were completed at nine sampling locations. Key project findings demonstrated that restored areas were supportive of fish communities similar to those found at natural sites and that mosaics of created coastal wetlands are functioning as high quality habitats for juvenile sportfish.
Jul 17, 2020 | TBERF


A news item headlined “The Dragon Storm” appeared on the Cassini mission website on February 24.
The imagery of the celestial dragon in this context is an unconscious nod to an electrified universe. The new science of plasma behavior emphasizes the dominant role of the electric force and its powerful effects in the electrically charged matter that makes up 99 percent of the universe. Plasma science is re-writing the textbooks on galactic, stellar, and planetary evolution. And it throws new interdisciplinary light on the ancient “doomsday” dramas involving a celestial dragon and the “thunderbolt of the gods.” This dragon storm on Saturn connects the modern science with the ancient dramas.
A few thousand years ago, ancient artists around the world carved similar complex images on stone. The meticulous research of plasma scientist Anthony Peratt, a leading authority on the forms taken by high-energy electrical discharges in plasma, has confirmed that these images pictured heaven-spanning forms seen in the ancient sky. Stories and rituals in all ancient cultures, memorializing a catastrophe that involved heaven-shattering battles of planetary “gods” and monsters, parallel these images. Most common is the story of the fiery serpent or dragon attacking the world.
Such archetypal images seem to be burned into our collective subconscious. For example, ringed planets often feature in a young child’s primitive drawings about space. Yet they have no experience of them. In the same way, scientists seem unconsciously to draw on archetypes. And the results are often equally surprising.
The Electric Universe model may explain the connection between the dragon of legend and the storm seen in this image. But first we should hear what Cassini mission scientists had to say:
A large, bright and complex convective storm that appeared in Saturn’s southern hemisphere in mid-September 2004 was the key in solving a long-standing mystery about the ringed planet. The Dragon Storm was a powerful source of radio emissions during July and September of 2004. The radio waves from the storm resemble the short bursts of static generated by lightning on Earth. Cassini detected the bursts only when the storm was rising over the horizon on the night side of the planet as seen from the spacecraft; the bursts stopped when the storm moved into sunlight. This on/off pattern repeated for many Saturn rotations over a period of several weeks, and it was the clock-like repeatability that indicated the storm and the radio bursts are related. Scientists have concluded that the Dragon Storm is a giant thunderstorm whose precipitation generates electricity as it does on Earth. The storm may be deriving its energy from Saturn’s deep atmosphere.
One mystery is why the radio bursts start while the Dragon Storm is below the horizon on the night side and end when the storm is on the day side, still in full view of the Cassini spacecraft. A possible explanation is that the lightning source lies to the east of the visible cloud, perhaps because it is deeper where the currents are eastward relative to those at cloud top levels. If this were the case, the lightning source would come up over the night side horizon and would sink down below the day side horizon before the visible cloud. This would explain the timing of the visible storm relative to the radio bursts.
The Dragon Storm is of great interest for another reason. In examining images taken of Saturn’s atmosphere over many months, imaging scientists found that the Dragon Storm arose in the same part of Saturn’s atmosphere that had earlier produced large bright convective storms. In other words, the Dragon Storm appears to be a long-lived storm deep in the atmosphere that periodically flares up to produce dramatic bright white plumes which subside over time. One earlier sighting, in July 2004, was also associated with strong radio bursts. And another, observed in March 2004 and captured in a movie created from images of the atmosphere (PIA06082 and PIA06083) spawned three little dark oval storms that broke off from the arms of the main storm. Two of these subsequently merged with each other; the current to the north carried the third one off to the west, and Cassini lost track of it. Small dark storms like these generally get stretched out until they merge with the opposing currents to the north and south.
These little storms are the food that sustains the larger atmospheric features, including the larger ovals and the eastward and westward currents. If the little storms come from the giant thunderstorms, then together they form a food chain that harvests the energy of the deep atmosphere and helps maintain the powerful currents.
Cassini has many more chances to observe future flare-ups of the Dragon Storm, and others like it over the course of the mission. It is likely that scientists will come to solve the mystery of the radio bursts and observe storm creation and merging in the next 2 or 3 years.
Credit: NASA/JPL/Space Science Institute
Calling the dragon storm “a giant thunderstorm whose precipitation generates electricity as it does on Earth” explains nothing. The generation of lightning on Earth remains a mystery to meteorologists. It is thought to derive from vertical movement of droplets in a thundercloud “in a way or ways not yet fully understood” [Lightning, Martin A. Uman, Dover Publications]. Hence the notion that “the storm may be deriving its energy from Saturn’s deep atmosphere.” As discussed elsewhere on this website, thunderstorms are electric discharge phenomena driven by the circuits that link planets to stars and stars to the galaxy. The electrical effects at Saturn have already been outlined in an earlier Electric Universe news item.
The report does not discuss the complex shape of the dragon storm. But that shape indicates an external origin of electrical power. Similar forms occur in plasma instabilities when an intense beam of electrons strikes a ‘witness plate.’
These two images show in cross-section what happens to a beam of electrons that is following an axial magnetic field. The image on the left is due to a 90 kiloamp current striking a carbon witness plate. The other image is due to a 58 microamp current striking a fluorescent screen. So in the laboratory the effect is scaleable over 12 orders of magnitude of beam current!
The same effect occurs in the Birkeland currents that drive the aurora on Earth and is responsible for the undulating auroral curtains. Scaling up from the size of Earth’s auroras to the storm on Saturn is no problem. The two prominent “spiral galaxy” formations in the dragon storm are likely the effects of the interaction of Birkeland current pairs. In other words, plasma phenomena may be scaled up from the laboratory to planetary, and even to galactic, dimensions.
Like Jupiter’s Great Red Spot, the dragon storm on Saturn seems to be a long-lived storm center that occasionally flares up. The clock-like regularity of the radio emissions from storms on Saturn is used to judge the great planet’s actual rotation rate beneath the clouds. But this behavior is enigmatic. Why should an electrical storm attach itself to a particular spot on a planet’s surface, particularly when that surface is thought to be liquid?
The Electric Universe model of stars and planets provides the possibility of a solid surface on the giant planets. And as we find on Earth, a solid surface allows for regional electrical differences that favor electrical storm activity in one region over another. A good example is “tornado alley” in the southern U.S.A.
The Electric Universe accepts the plasma cosmology version of star formation, which postulates that a star is formed in a ‘z-pinch’ in a galactic electric discharge. It is a model that can be shown experimentally to work. In contrast, the gravity cosmology version, which postulates that a star is formed by the collapse of a cloud of gas, cannot be demonstrated experimentally nor can a collapsing cloud be identified observationally. Furthermore, this ‘nebular theory’ is beset with theoretical contradictions of angular momentum and magnetic field distribution.
In the Electric Universe, stars do not “consume themselves” to fuel their radiant output. The same galactic currents that formed them remain to light them. This means that stars are born electron deficient with respect to their galactic environment. It also means that galaxies be born similarly electron deficient with respect to their environment. It is the slow galactic charging process that maintains the steady glow of their countless starry electric lights.
Early in the Twentieth Century astronomers dismissed the notion of an external power source for stars because they thought a star would swiftly collapse under its own weight unless there was a central source of radiation pressure to prevent it. But this argument fails if charge separation occurs in massive bodies. This possibility of charge separation was considered, but it was discarded by arguing, using the ideal gas laws, that the light electrons would not rise to the top to any significant degree in a hydrogen atmosphere.
This is a prime example of an inappropriate model rendering all further theorizing worthless. The physicists would have been well advised to look to the chemists for a better model – one in which the electric dipole force between atoms and molecules plays a dominant role. Because the atoms in a strong gravitational field will be distorted, the heavy positively charged nucleus will be offset from the center of the atom toward the center of the star. The result is that each neutral atom becomes a small radial electric dipole. The effect on free electrons is to cause them to drift toward the surface, leaving positively charged ions behind in the interior. The repulsive forces among these positively charged ions prevent the gravitational collapse of the star.
Furthermore, the visible “surface” of a star, or photosphere, is an electric discharge phenomenon and therefore not controlled by gravity. The standard model of stars assumes that gravity and radiation pressure determine the size of a star. That is not so in the electrical model. So conventional calculations of the density of stars and their internal composition have no real meaning.
But there is more. Physicists assume that Newton’s law of gravity has a “universal” gravitational constant, “G,” which is the same for all bodies in the universe. But “G” is the most elusive constant in physics. It seems to be different every time the same apparatus measures it on Earth. The Electric Universe takes a different view. “G” depends on the internal electric stress of the body and is different for every body in the universe. This effect can be seen in particle accelerators where matter apparently gains in mass in response to the amount of electrical stress that is applied to it.
So deducing the composition and structure of stars and planets by measuring their gravitational fields and assuming “G” to be a fixed value will give misleading results. Conventional models assume planets are accreted from a hypothetical primordial solar nebula. They also assume that hydrogen is compressed to a metallic state in the cores of gas giants. These assumptions too are invalid in an Electric Universe.
Planets are “born” fully formed from larger bodies. They are not accreted. The process of having planetary “children” is that of electrical expulsion of a part of the positively charged matter from beneath the surface of a disturbed star or gas giant. That is why the gas giants have satellite systems that are like miniature solar systems. The British physicist Peter Warlow was moved to write:
All of the existing theories of planet formation have taken material from the surface of the Sun or from a cloud of dust outside the Sun in order to form the planets, for the ‘obvious’ reason that planets are on the outside of the Sun. We humans, equally ‘obviously,’ are outside our mothers – yet we did not start there.”
[The Reversing Earth, 1982].
Some measure of the internal composition of stars can be seen in their “children” – the gas giants. But all we can see and measure is the upper atmospheres and clouds of the gas giants. To delve deeper we need to look at the “children” of gas giants – the rocky planets and moons. Clearly, each planet and moon may have a complex history. All were not formed at about the same time in a single event. And the larger bodies must have evolved discontinuously with each birth. So it was with Saturn!
The ancients knew Saturn as “the Sun of night.” The archaic words we now associate with the Sun—Ra, Helios, Shamash, etc.—originally referred to Saturn. Saturn’s core is still hot (Saturn radiates more than twice the energy that it receives from the Sun) because of Saturn’s recent history as a radiant body. This suggests that beneath Saturn’s clouds is a large, hot, solid body practically indistinguishable in composition and physical state from Venus or Earth. Its positively charged core prevents hydrogen from being compressed to the metallic state. With a solid core and having “given birth” fairly recently – as evidenced by the ephemeral icy rings – Saturn probably still bears the birth scar, hidden beneath the clouds. We might expect some preference for continued electric discharge from that scarred region.
Saturn is the most oblate planet in the solar system. Its equatorial winds are four times faster and the “jets” twice as wide as Jupiter’s. These factors suggest an atmosphere of great depth. This may explain why the radio noise associated with the dragon storm seems to precede the storm. The tornadic discharge to the surface of Saturn must be skewed over a considerable distance by the high-speed winds and great depth of the atmosphere. Only the powerful electromagnetic forces that control a tornadic discharge could maintain the integrity of the discharge column under the onslaught of tremendous vertical wind shear. (The winds in the upper atmosphere have been estimated to exceed 1000 mph.)
The Electric Universe model provides a connection between the dragon of legend and the storm seen in the Cassini image. The model was built, not from theoretical considerations alone but from an interdisciplinary inquiry into the images of planets (represented as disks) and cosmic plasma phenomena that our ancestors felt were so important to remember. They chiselled millions of uniquely diagnostic patterns, known as petroglyphs, into solid rock. But with the context long gone, these petroglyphs have become a mere curiosity.
Meanwhile the physical clue for an intimate relationship in the past between Saturn, Mars and Earth lies in their similar axial tilts of 26˚, 24˚ and 23˚. The axis of a rapidly spinning planet has a gyroscopic stability that resists change due to external forces. The normal result of disturbance is merely to cause the axis to slowly precess.
The first civilizations sprang up in reaction to the dramatic prehistoric events. The activities of those civilizations—their organization, art, architecture and rituals—were directed toward the memorialization of the former celestial drama. It is there we first meet the inexplicable, capricious planetary gods and the world-threatening, fire-breathing celestial dragon or serpent. So it is fitting that scientists today should unconsciously associate the dragon image with a powerful plasma discharge on Saturn. However, the connection will only become consciously apparent when the electrical nature of the universe is acknowledged. Only then may scientists solve the mysteries of Saturn’s dragon storm.


Water distribution pipes installed underground have potential risks of pipe failure and burst. After years of use, pipe walls tend to be corroded due to aggressive soil environments where they are located. The present study aims to assess the degree of external corrosion of a distribution pipe network.
data obtained through test pit excavation and direct sampling are carefully collated and assessed. A statistical approach is useful to predict severity of pipe corrosion at present and in future. First, criteria functions defined by discriminant function analysis are formulated to judge whether the pipes are seriously corroded. Data utilized in the analyses are those related to soil property, i.e., soil resistivity, pH, water content, and chloride ion. Secondly, corrosion factors that significantly affect pipe wall pitting (vertical) and spread (horizontal) on the pipe surface are identified with a view to quantifying a degree of the pipe corrosion. Finally, a most reliable model represented in the form of a multiple regression equation is developed for this purpose. From these analyses, it can be concluded that our proposed model is effective to predict the severity and rate of pipe corrosion utilizing selected factors that reflect the fuzzy soil environment.
The water system plays an important role as a lifeline for our existence. It is through pipelines that water is distributed to customers for steadiness and safety. Water pipes, however, tend to be corroded as time goes by. Pipes laid underground are hardly examined without excavation. Some deteriorated pipes may be exposed to leakage or damages, resulting in the decline or interruption of water supply. In order to maintain customer service at a desirable level, replacement of such old pipelines is considered inevitable. As the replacement of pipelines requires huge costs and time, there is a pressing need to provide information on how to evaluate the pipe condition in an effective way.
Deterioration or corrosion of pipes may cause cracks and bursts, resulting in water leakage, pipe repair, and poses even the so-called water quality problem ‘red water’. Occurrence of the corrosion relates to many factors: pipe materials, pipe age, surrounding soil conditions, water quality, pipe maintenance and management
. It is, therefore, difficult to examine where the corrosion is taking place and the extent of it. Corrosion of the outer surface of the metallic pipes occurs mainly due to electrochemical reactions under the heterogeneous soil condition. The reaction rate is influenced by soil resistivity, permeability and mineral ions existing around the installed pipes
Most of the previous researches dealt with causual analysis of pipe corrosion and prediction of future corrosion for water distribution pipes. Katano et al.
found the log-normal distribution fit their pit data the best and analyzed environmental factors using regression analysis. The environmental factors (soil type, pH, resistivity, redox potential, and sulfate ion) were found to be significant in determining pit depth. Kolovich and Kiefner
developed the Monte Carlo method for determining the corrosion rate distribution in buried pipelines that uses the probability distributions of corrosion depth and initiation time. Restrepo et al.
employed statistical techniques like cluster analysis to establish the sampling design and later for data analysis and obtaining a mathematical expression for external corrosion depth as a function of several experimental variables
. In addition, various studies have reported different methodologies used to be able to predict the future trend of corrosion for water pipeline.
The present study has strengths that although data is insufficient, effective evaluation of the current condition and prediction model can obtain a clear quantitative model by statistical approach and application is easy in other areas because of high reproducibility. In order to obtain a quantitative model for measuring pipe corrosion, we propose to apply an evaluation index to fuzzy environmental soil conditions around water pipes.
The present study aims at proposing an approach and method to predict the intensiveness and probable points of pipe corrosion in the pipe network. Base data utilized for the prediction are those sampled at the site. Objectives of the study are referred to: 1) obtain evaluation indexes for external corrosion reflecting the fuzzy soil nature of installation sites; 2) develop a multiple regression model to measure the degree of pipe corrosion under the fuzzy soil conditions; and 3) evaluate future risk and timing for decision of pipeline replacement.
2. Materials and Methods
The study focuses on the existing distribution pipe network in S city, South Korea during 2009–2010
. Field data on pipe corrosions and soil conditions around pipes were obtained in the previous research project including those of the test pit excavation at 60 random locations along the water distribution pipelines (
). The study area extends to 121.05 km
with a population of approximately 1.11 million
shows relevant data for this analysis with their mean values and standard deviation. The external corrosion is measured by two indexes: external corrosion depth given as localized corrosion index (Y
), and corrosion spread on the pipe’s surface given as general corrosion index (Y
). Influential factors are grouped into two: factors related to ‘characteristic of water pipe’ and ‘soil condition’. The former contains 3 items, all of which are obtained from geographic information system (GIS) database of the distribution pipe network. The latter are 4 items as measured from soil sample testing.
The previous studies suggest synergistic effect of the external corrosion depth (Y
) and the corrosion spread (Y
) on pipe breakage
. Following the spread of general corrosion, the localized corrosion may occur at a specific point on pipes coincidentally. So we have analyzed these two types of corrosion in parallel.
Prior to the main analysis, corrosion conditions are presented in histograms to show cumulative frequency vs. corrosion level (
). No pipe corrosion is found at 47% of randomly selected sample points. Despite the pipe age of 12 to 52 years, some newer pipes (under 20 years) have deeper and/or wider spread of corrosion than the average. To the contrary, there are some uncorroded samples found in older (over 40 years) pipes. This tendency is considered to be closely related to characteristics of the surrounding soil conditions and the pipe conditions which are not protected by a polyethylene sleeve. Next, histograms are created for each of the soil properties in order to make it easy to understand a distribution of samples
Items for analysis
Sampling points in S city.
Histogram of the depth of external corrosion (Yd).
). For soil resistivity, it was identified by the American National Standards Institute (ANSI) method that only four samples had measurement values below 700 to be under the very highly corrosive soil condition, and around 72% of samples indicated values above 2,000 to be sampled from the extremely low corrosive soil condition. As pH’s histogram shows, also, only one sampling point had acidity of less than 4, whereas 7 sampling
Histogram of the spread of general corrosion (Ya).
Histogram of soil resistivity.
Histogram of pH.
points were found to have alkalinity of over 8.5. Next, in relation to water content, exactly half the samples is obtained from dry contition (water content is less than 10%). Lastly, chloride ion was detected from 87% of soil samples. These figures illustrate that the sampling points covered a wide range of soil conditions.
Then, the corrosive condition of soil samples was evaluated using the modified ANSI method and the German Waterworks Association (DVGW) method which are the most representative
Histogram of water content.
Histogram of chloride ion.
methods for evaluation of soil corrosivity. As the results, nearly 47% of soil samples were evaluated as the corrosive condition (middle and strong corrosivity) by the modified ANSI method. On the other hand, around 88% of soil samples were found to be evaluated as weak corrosivity and 12% soil samples as middle corrosivity using the DVGW method. Also, the relation between the corrosive condition of each soil sample was evaluated by two methods and the actually measured external corrosion is shown in
illustrate, there are samples that actually measured external corrosion depth and spread of general corrosion have low values with the high score of modified ANSI and also have high values with the low score of modified ANSI. Similarly, between actually measured values of external corrosion and absolute values of DVGW score don’t have definite relationship as shown in
. These results mean that there are significant differences between the actually measured external corrosion and the corrosive condition evaluated by the two methods above. Thus, it is considered that a new evaluation method of corrosivity regarding soil samples should be developed.
In this study, in order to obtain a more reliable model to predict the degree of pipe corrosion, the relationship between external corrosion and soil property is further investigated by applying discriminant function analysis (DFA). From examining the discriminant function, we quantify the soil environment corrosivity using some combination of variables in which the
Relation between score of modified ANSI and external corrosion depth. ANSI: the American National Standards Institute.
Relation between score of modified ANSI and spread of general corrosion. ANSI: the American National Standards Institute.
fuzzy soil property is reflected. The multiple regression model (MRM) is to measure the degree of pipe corrosion. In developing MRM, some of the pipe characteristics are considered effective as explanatory variables together with the selected variables in the DFA. By developing the MRM, the degree of pipe corrosion at some points is predicted for evaluation of present and future risk.
3. Results and Discussion
- 3.1. Discriminant Function Analysis
In order to distinguish the corrosive soil environment in all soil samples, DFA is applied to this analysis. Common purpose of the DFA is to predict the group membership based on a linear combination of variables using a measure of generalized square distance assuming that each group has a multivariate normal distribution. Another purpose of DFA is to acquire insight into the relationship between the group membership and variables in the prediction model which is given as a discriminant function.
At the beginning of DFA, observations for each group are made including both high-ranking and low-ranking samples reflecting a characteristic of the universe (the population of all samples). In this study, two groups, namely, a corrosive group (named BAD group) and a non-corrosive group (named GOOD group) are considered for each discriminant function corresponding
Relation between absolute value of DVGW score and external corrosion depth. DVGW: the German Waterworks Association.
Relation between absolute value of DVGW score and spread of general corrosion. DVGW: the German Waterworks Association.
to each corrosion indexes (Y
). The modeling process with the discriminant function is proposed in the following order as shown in
Step 1. Set sample condition for BAD and GOOD group
Step 2. Balance sample size between BAD and GOOD group
It is a normal procedure that DFA focuses merely on data ranked high and low (namely, the first quarter and the last quarter of the sorted samples). In this study, 16 samples (almost the last quarter) which had over 0.6 mm of corrosion depth are regarded as the BAD group corresponding to Yd, and 12 samples with over 10% area corrosion are categorized into the BAD group corresponding to Ya. On the other hand, the GOOD group consists of no external corrosion samples both for Ydand Ya. As the numbers of effective data differ between these groups, a measure to balance the sample data is required.
Step 3. Examine whether each environmental factor is logically acceptable
To ensure stability of DFA, two groups are preferably equal in data size. As the number of samples in the GOOD group is greater than sample size of the BAD group, random sampling methods are adopted to select samples for the GOOD group. Several sets of samples are arranged so that the Good group may have same sample size to the BAD group, and then the corresponding models for classification are examined as below.
Development process of discriminant function analysis model.
Step 4. Estimate discriminant function
After adjusting the sample size of both groups, the average value of each environmental factor for each group is compared. When the average value of an environmental factor in the BAD group is higher than that of the GOOD group, such a factor is judged to have logicality, excluding soil resistivity (X4), which has the opposite tendency.
As for external corrosion depth (Y
), equations obtained from the analyses are assessed as highly reliable. Eq. (1) represents a linear discriminant function. If a classification index (Z
) estimated from this equation is greater than zero, it is considered that the sample falls into the GOOD category. This implies the external corrosion depth within the range of less than 0.6 mm. Explanatory factors (X
) are standardized as expressed in Eqs. (2) and (3), respectively.
shows their mean values (m
) and standard deviations (s
). From coefficients in the Eq. (1), W
has a larger absolute value than that of W
. This indicates that the soil resistivity (X
) is more influential than the water content (X
) on the external corrosion depth.
The DFA model is developed with the aid of SAS ver. 6.03 (SAS Institute Inc., Cary, NC, USA) as a function of the selected factors, logically reasonable. For depth of external corrosion (Yd) and spread of general corrosion (Ya), 5 randomly sampled cases are analyzed respectively. The most reliable DFA models are selected for Ydand Yawhich have the highest hit ratio, respectively.
On the other hand, as for the spread of general corrosion (Y
), the soil resistivity (X
) is found as an influential factor. Eq. (4) stands for a linear discriminant function obtained for Y
. A standardized variable, W
in Eq. (4), is similar of the soil resistivity (X
) as presented in the Eq. (2) above. If Z
is greater than 0, then the sample is classified to the GOOD group. This implies that the spread of general corrosion is estimated as less than 10% of pipe surface.
- 3.2. Modeling of External Corrosion
Evaluation indexes of fuzzy soil properties can be obtained from the linear discriminant functions. From these indexes, we can assess corrosiveness of the soil properties. It is found that low resistivity and/or high water content of the soil properties accelerate the rate of external corrosion depth. In the case of the general horizontal corrosion, however, the low resistivity of the soil is considered dominant in affecting an extent of the spread area and its corrosion rate. As to external corrosion prediction, regression analysis is applied to find influential factors related to pipe characteristics. Among 60 sampled data, nearly half of the sampled data didn’t find corrosion on pipe surface. To minimize the effects on the regression model, these data are omitted in the succeeding analyses. The number of data utilized is twenty and nineteen samples for external corrosion depth and general horizontal corrosion, respectively.
It is believed that pipe characteristics and soil properties have linear and non-linear effects on pipe corrosion
. To incorporate these effects into the analyses on a same basis, this nonlinear effect is first expressed in the form of power regression equations with a variable of pipe characteristics. Then, multiple regression equations for the two types of external corrosion (Y
) are formulated as a function of the selected factors expressed in linear and/or non-linear forms.
Prior to regression analysis, the correlation coefficient for the logarithmic data of pipe characteristic factors with corrosion indexes are estimated as shown in
. Significant levels of reliability are confirmed as a result of the t-distribution test corresponding to sample size ‘n’ and statistically significant level ‘’. When an absolute value of the correlation coefficient is greater than its significance level, the factors are assessed as statistically significant. In
, the depth of external corrosion (Y
) has a non-linear relation with pipe age (X
), and spread of general corrosion (Y
) with diameter (X
). These results suggest the effectiveness of adopting each factor as one of the explanatory variables in the corrosion prediction equations.
Step 1. Power regression model for external corrosion depth
Firstly, the regression model for between depth for external corrosion (Yd) and pipe age (X3) was made in the form of power function. According to Eq. (5), the estimated power coefficient (1.670) is greater than 1.0. This implies that the pipe age would affect pipe deterioration with acceleration as seen inFig. 13.
Step 2. MRM for external corrosion depth
Following DFA and regression analysis in the form of power function, multiple regression analysis (MRA) is applied for further analysis. As the explanatory variables, the MRA utilizes pipe age expressed as 1.67thpower, soil resistivity (X4) and water content (X6) as previously verified effective by the discriminant function. This regression model expressed in Eq. (6)
Estimated trend of depth of external corrosion according to pipe age.
Estimated values of external corrosion depth.
Logarithmic correlation between items of external corrosion and pipe characteristicsr: standard value of correlation coefficient at α-significant level.**The correlation coefficient is significant at 0.05 (bilateral).
Logarithmic correlation between items of external corrosion and pipe characteristics r: standard value of correlation coefficient at α-significant level. ** The correlation coefficient is significant at 0.05 (bilateral).
is assessed statistically significant from its multiple correlation coefficient (R) obtained through the t-distribution test. The relation between the observed and the estimated values of external corrosion depth is shown in
, which indicates sufficient accuracy of our model with a mean absolute error, 0.33 mm.
Estimated trend of spread of general corrosion according to diameter.
Location where corrosion depth will exceed 2 mm by 2030.
Step 3. Power regression model for spread of general corrosion
In the same way as stated above, a prediction model for the spread of general corrosion (Ya) is expressed as a factor of the pipe diameter (X1). The negative power (i.e., -1.435) of X1implies that value Ya(the corrosion spread on pipe surface in percentage) tends to progressively decrease against an increase in value X1(the pipe diameter). This tendency is clearly seen inFig. 15.
Step 4. MRM for spread of general corrosion
Severity of the general corrosion for any pipes in the target area can be simply estimated from the equation. Data required for prediction are merely pipe diameter and soil resistivity in the targeted area. The equation is not expressed as the function of pipe age. This is due to the fact that the general corrosion rate per year is rather slower than that of the external corrosion depth. Continuous efforts are required to collect data on pipe corrosion. It may be possible to develop a more reliable prediction model based on the process as mentioned above.
The main culprit behind the general corrosion is soil resistivity (X4) among soil properties. According to the findings of regression analysis, pipe diameter (X1) is considered to have a negative relation with the general corrosion (Ya). In a multiple regression equation developed here, there are two independent variables as shown in Eq. (8). A correlation coefficient of the equation is estimated at 0.696. As examined by the tdistribution test, this value is able to ensure reliability of the equation.
- 3.3. The Corrosion Model Evaluation
In the previous paragraph, a prediction model for the external corrosion depth (Y
) represented by pipe age (X
), soil resistivity (X
), and water content (X
) was proposed.
Another method is a prediction which considers the soil environment around the pipes. Corrosion depth of 60 samples in the future is tentatively forecast in the Eq. (6), assuming that the pipes are left without any maintenance for 20 years. In this study a depth of external corrosion over 2 mm is considered serious and may result in pipe damage or leakage. Analyzing the result of forecast, a total of 27 out of 60 samples are expected to have serious external corrosion with a depth exceeding 2 mm on their pipe surface. Locations of those samples are given in
. Out of total 60 soil samples, 39 consist of soft clay and 17 of red clay, while 4 samples are of sands. Soft and red clay, accounting for nearly half of the total are causing a rapid growth of corrosion, but the remnants are rather slow in corrosion, as they are predicted not to reach 2 mm. These results indicate that future risk of corrosion closely relates not only to the soil factors but also to the pipe characteristics.
This study intended to predict the severity of pipe corrosion in the target area. The study was carried out through assessment of various data collected at survey points. Results of the analyses indicate that influential parameters on external corrosion depth (Y
) are soil resistivity (X
), water content (X
), and pipe age (X
). It is also confirmed that the soil resistivity (X
) and the pipe diameter, among others, affect the spread of general corrosion (Y
). From all the above, it can be concluded that the multiple regression equation obtained herein provides valuable information on the degree and rate of external pipe corrosion in the target area. The proposed process for future risk evaluation is also effective to decide pipeline replacement and planning. Continuing efforts for collecting and storing up field data are, however, considered important to improve the reliability of the proposed prediction model obtained through statistical analyses.
Corrosion rate evaluation and prediction for piles based on long-term field performance.
J. Geotech. Geoenviron. Eng.
Japan Ductile Iron Pipe Association (JDPA).
Technical report about the factors of corrosion and anticorrosion measures for buried pipes.
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Iron corrosion scales: model for scales growth, iron release, and colored water formation.
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Predictive model for pit growth on underground pipes.
Calculation of a corrosion rate using Monte Carlo simulation.
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Evaluation of current condition and lifespan of drinking water pipelines.
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The technical analysis of water supply system in Suwon.
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2011 Sep 27-30
Statistical analysis of the corrosion of water distribution pipes under their environmental factors.
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Probability distribution of pitting corrosion depth and rate in underground pipelines: a Monte Carlo study.


In the new documentary “Dispatches from the Gulf,” the scientists are the heroes. The film airs for the general public for the first time via livestream on April 20 at 2pm and 7pm eastern. I got a sneak peek of the film, and trust me—you won’t want to miss it.
Since the BP Deepwater Horizon oil disaster began in 2010, hundreds of scientists around the country have been documenting the impacts of the tragedy on the wildlife and habitats of the Gulf of Mexico. This documentary tells the stories of these scientists, from the University of Miami team that built the equivalent of a treadmill for mahi mahi to test their endurance and see how oil has affected their hearts, to Christopher Reddy, the Woods Hole Oceanographic Institute scientist who scours the beach for tar balls with a simple tote bag and pair of purple gloves.
Their stories are pretty inspiring. For me, the most memorable part was watching Dr. Mandy Joye, professor of marine sciences at the University of Georgia, climb into the remotely operated vehicle (ROV) “Alvin”—the same ROV that explored the wreckage of the Titanic. Dr. Joye then traveled 90 minutes in the Alvin to the bottom of the Gulf, where she found a shocking amount of oil on the seafloor.
The work these scientists are doing is important to understand how the Gulf’s wildlife and habitats are recovering—or if they’re not recovering, why. For the creatures that live in the deep, blue ecosystem of the Gulf, expanding research and monitoring is one of our only options for restoring their populations. In the case of the Exxon Valdez oil disaster, the herring fishery collapsed unexpectedly after four years. The Gulf supports a giant seafood industry, and we don’t want to see a similar crisis strike here. That’s why we need science to understand how our fish and wildlife are coping with the stress of the BP oil disaster.
If there is something to be gained from this tragedy, it is knowledge. Many of the lessons we are learning about the Gulf in the aftermath of the BP oil disaster can be applied elsewhere in the world. If a researcher from the other side of the world wants to know how fish and corals in the deep sea are affected by exposure to oil, they will turn to our scientists in the Gulf. The Gulf stands on the forefront of a unique opportunity to lead in the field of marine science, but only if we make science a priority in the effort to restore the Gulf.


Each of us sees things from our unique perspective. We understand the world around us through an unconscious thought process. We constantly form and update beliefs and values that we apply to assess the situation, formulate alternatives, make decisions and interpret the intentions of others.
But since we are constrained by our own experience, our perception of the world is inherently limited. Our understanding is imperfect. How often do we recognize this? What should we do about it?
Chris Argyris used the metaphor of the “ladder of inference” to describe the mental process for understanding what we experience. In this model, we process information through each of seven steps (starting with reality or facts) that lead to beliefs and ultimately taking action. As Argyris and his co-author Donald Schon explain in their 1974 book “Theory in Practice: Increasing Professional Effectiveness”, most individuals are not aware of this process or how pre-existing beliefs impact our interpretations and behavior.
Do we all interpret the situation in the same way? How do we know? With awareness of the limits of our single point of reference, we can slow down and actively move to increase our shared understanding with collaborators. We can ask questions and make things as explicit as possible — especially when the stakes are high.


After a long, cold winter, Hoosiers can’t wait to get outdoors during longer days of sunshine to begin long, put-off chores in the yard. But before heading out with a ladder or a shovel, looking up and down for electric power lines and equipment might save your life — or at least extend the lives of trees and other greenery you intend to plant.
“Ladders present safety issues no matter at which end you stand,” said Rick Coons, CEO at Indiana Electric Cooperatives. “Anyone who’s ever scaled a ladder has thought about a fall from the top, but there’s a danger when we’re moving the ladder on the ground that we might not immediately consider: overhead power lines.”
Here are important points to consider with overhead power lines:
- Look up and around. Always be aware of the location of overhead power lines. Ladders and other long items, like pool cleaning tools, should be carried horizontally whenever possible.
- Keep equipment and people at least 10-15 feet from lines. Never trim trees near power lines. Don’t place a ladder where it could fall into a power line.
- Never approach power lines knocked down by a storm, or try to move broken tree limbs or branches that might be entangled in power lines. Power lines, though damaged and silent, can still be fully energized and dangerous.
Overhead is not the only place electric power lines cross our yards or bring electric service to the meter on the house. In many suburban neighborhoods, buried power lines have become the norm. While this means there are no poles and wires running overhead to worry about, they still require special consideration:
- Underground power lines require those green boxes, called pad-mount transformers. Though it may be tempting to hide them with landscaping, please don’t. Your electric cooperative might have to open that equipment during a power outage or for routine maintenance.
- Keep shrubs and structures at least 12 feet from the “door” of the box, and at least 3 feet from the sides.
- If landscaping is too close, inadequate air circulation can cause equipment to overheat and fail. Plantings might have to be cut and removed.
- Keep the meter on your house visible and accessible, too.
- Never allow children to play on or around the pad-mounted transformers. They contain electrical equipment with high voltage inside.
- Do not plant near underground utility services. Tree roots can grow and interfere with underground pipes, cables and wires. Future repairs to these facilities also could damage the health and beauty of nearby plants and trees.
- At least a few days before planting, call 811, the underground utility locator service, to come out and mark the locations of underground utilities.
Indiana Electric Cooperatives also wants consumers to remember to never use electric yard tools with a power cord when the ground is wet, and always make sure your power tools are plugged into an outlet with a ground fault circuit interrupter (GFCI).
Sources: Electrical Safety Foundation, NRECA, Electric Consumer