cssi/SciSciGPT-SciSciNet huggingface dataset:
Explicit Instruction and Next Generation Science Standards Aligned Classrooms: A Fit or a Split?

The purpose of this article is to discuss the use of explicit instruction in the curriculum area of science where non-explicit approaches (e.g., discovery learning) are often used. While there has been a relative paucity of research on explicit instruction in science classrooms, we argue that explicit instruction, particularly when it is embedded within an inquiry approach aligned to the Next Generation Science Standards, has the potential to increase achievement in science for students with LD. Based on previous research, we provide potential ways to implement the five core instructional components of explicit instruction in today's inquiry-based science classrooms.
Developing gene drive technologies to eradicate invasive rodents from islands

Island ecosystems are highly threatened by invasive rats and mice. Currently, the only effective technology for eradicating rodents from islands is toxicants. Though effective, they are expensive a...
Ultralow power acoustic feature-scoring using gaussian I-V transistors

This paper discusses energy-efficient acoustic feature-scoring using transistors with Gaussian-shaped I DS –V GS . Acoustic feature-scoring is a critical step in speech recognition tasks such as speaker recognition. Suited to the transistor, we discuss a novel acoustic model based on the harmonic mean of Gaussian functions, yielding a much-simplified physical implementation. Compared to digital CMOS, the discussed implementation reduces energy dissipation of a 13-dimensional mixture function by 45×. For a test-case recognizing among seven speakers, the design reduces power dissipation by 7.8× than digital CMOS. Exploiting the simplified mixture function, we present algorithmic overdesigning for resiliency against hardware imperfections.
DNA Markers in Huntington’s Disease

Huntington’s disease (HD) is an autosomal dominant human disease that represents a truly fascinating biological problem (1–4). Individuals bearing the HD gene display normal central nervous system development as far as can be determined with currently available technology. Initially they are biochemically, neurologically and behaviorally indistinguishable from non-gene carriers. The gene is fully penetrant, however, and eventually, the HD victim begins to show signs of the disorder. This usually occurs in middle age but can be as early as two years in the rarer juvenile cases. The most striking feature of HD is the movement disorder that starts subtly as clumsiness or awkwardness of gait and inevitably progresses to exaggerated involuntary “dance like” (choreiform) movements or extreme rigidity. The disease was originally termed Huntington’s chorea subsequent to its description in 1872 by George Huntington, a Long Island physician (1). The name was later changed to Huntington’s disease when it was appreciated that psychological and intellectual changes are also commonly seen and sometimes precede the onset of the movement disorder.
Colorectal cancer characteristics and outcomes after solid organ transplantation.

e24131Background: Individuals post-solid organ transplant can develop several secondary malignancies. We noted an increasing number of individuals seen over the last several years who developed col...
Bat biosonar study using spatial audio techniques

Bats have highly specialized hearing adaptations that give them target detection, localization, and interception abilities that far surpass any man-made SONAR. There is a large body of research that has studied and attempted to mimic this remarkable natural sonar system using various methodologies. In many studies, multiple microphones and time difference of arrival were used for bat ultrasonic wave measurements. In this work, a new method using spatial audio techniques is introduced for bat biosonar measurements and analyses. A custom-built tetrahedral soundfield microphone that captures high-frequency sound up to 80 kHz from all directions was developed to acquire bat ultrasonic echoes in Ambisonic B-format. The recorded sound was processed using the HARPEx (High Angular Resolution Planewave Expansion) technique that decodes the 1st order spherical harmonics of the soundfield at the microphone into two plane waves in each time-frequency bin. The use of the soundfield microphone and associated processing provides new tools for analysis of bat echoes from the perspective of the bat. This talk will present details of the hardware and software development along with experimental validation results.
Civilian victimization and international military intervention in civil wars

Civil wars are particularly destructive and asymmetric in nature. As a result, humanitarian crises and episodes of one-sided violence against civilians are likely to emerge. In the post-Cold War er...
Optogenetic control of Bacillus subtilis gene expression

The Gram-positive bacterium Bacillus subtilis exhibits complex spatial and temporal gene expression signals. Although optogenetic tools are ideal for studying such processes, none has been engineered for this organism. Here, we port a cyanobacterial light sensor pathway comprising the green/red photoreversible two-component system CcaSR, two metabolic enzymes for production of the chromophore phycocyanobilin (PCB), and an output promoter to control transcription of a gene of interest into B. subtilis. Following an initial non-functional design, we optimize expression of pathway genes, enhance PCB production via a translational fusion of the biosynthetic enzymes, engineer a strong chimeric output promoter, and increase dynamic range with a miniaturized photosensor kinase. Our final design exhibits over 70-fold activation and rapid response dynamics, making it well-suited to studying a wide range of gene regulatory processes. In addition, the synthetic biology methods we develop to port this pathway should make B. subtilis easier to engineer in the future. Bacillus subtilis has complex spatial and temporal gene expression patterns but currently lacks optogenetic tools to explore these processes. Here the authors import and debug a cyanobacterial green light sensor pathway and show that it enables precise optical control of gene expression.
The Case for Comparative and Development Public Administration in the Energy Sector

This paper argues for the need for a Comparative and Development Administration framework for the benefit of the energy sector of developing countries. It emphasizes the need to learn from the challenges faced by the early editions of such frameworks while laying out the different options of aid and assistance available for developing countries to build their local institution and governance structures.
A Theory of Firm Value Capture from Employee Job Performance: A Multidisciplinary Perspective

Understanding the impact that employee job performance has on firm value creation and capture has been an enduring challenge. Micro management scholarship has focused on employee job performance be...
Quantification of uncertainty in a new network model of pulmonary arterial adventitial fibroblast pro-fibrotic signalling

Here, we present a novel network model of the pulmonary arterial adventitial fibroblast (PAAF) that represents seven signalling pathways, confirmed to be important in pulmonary arterial fibrosis, as 92 reactions and 64 state variables. Without optimizing parameters, the model correctly predicted 80% of 39 results of input-output and inhibition experiments reported in 20 independent papers not used to formulate the original network. Parameter uncertainty quantification (UQ) showed that this measure of model accuracy is robust to changes in input weights and half-maximal activation levels (EC50), but is more affected by uncertainty in the Hill coefficient (n), which governs the biochemical cooperativity or steepness of the sigmoidal activation function of each state variable. Epistemic uncertainty in model structure, due to the reliance of some network components and interactions on experiments using non-PAAF cell types, suggested that this source of uncertainty had a smaller impact on model accuracy than the alternative of reducing the network to only those interactions reported in PAAFs. UQ highlighted model parameters that can be optimized to improve prediction accuracy and network modules where there is the greatest need for new experiments. This article is part of the theme issue 'Uncertainty quantification in cardiac and cardiovascular modelling and simulation'.
A review on 3D printing techniques for medical applications

Additive manufacturing, or three-dimensional (3D) printing, joins materials layer-by-layer under the control of a computer to create three-dimensional objects. 3D printing is used in many applications, including the automotive industry, the environment, electronics, airplane engines, agriculture, and even architecture. One of the most critical applications of this ultra-modern technology is medicine. 3D printing permits new methods of surgical planning and tissue regeneration, as well as personalization of medical devices and implants. With the development of materials that are both biocompatible and printable, additive manufacturing is becoming increasingly useful in medicine.
Gender differences in tibial fractures healing in normal and muscular dystrophic mice

Duchenne muscular dystrophy (DMD) patients have a high fracture risk and poor fracture healing. The dystrophin-/- (mdx) mouse is a murine model of DMD and exhibits delayed bone fracture healing. Since our research team has shown that adult stem cells, such as muscle-derived stem cells, display a gender difference in their osteogenic potential with the male cells being more osteogenic, we hypothesize that a potential gender differences may exist during bone healing in normal and mdx mice. To test this hypothesis, wild-type (WT) and mdx mice underwent tibial fracture surgery and microCT live scanning biweekly. The mice were sacrificed at 6 weeks post-surgery and the calluses were collected for histological analysis. To further investigate the mechanism, another two sets of mice were sacrificed at 10 days after fracture for RNA extraction and gene expression analysis and histology. MicroCT results showed, at 6 weeks post- surgery, the calluses were larger but showed less remodeling in both normal and mdx male mice when compared to females, at the same time point. However, females had higher callus bone volume density and an increase in osteoclast (OCs) number. At 10 days after fracture surgery, male mice had formed larger calluses, whereas females formed well-remodeled calluses with more osteoblasts and a greater bone area for both WT and mdx mice. Higher IGF-1 expression was observed in male mdx mice when compared to their female counterparts, whereas female WT mice had higher BMP-9 expression when compared to WT males. In conclusion, male mice formed larger bone calluses than females during tibial fracture healing for both WT and mdx mice. This may be attributed to higher IGF-1 expression, activation of Wnt/β-catennin signaling pathway and greater OB numbers during callus formation. Female mice achieved better bone remodeling in the regenerated bone with higher bone quality due to increased OC numbers that promote faster remodeling of the fracture calluses, and higher BMP-9 expression levels. Therefore, gender is one of many factors that need to be considered for both animal and human bone research.
Prevalence and Predictors of Compromised Bone Mineral Density in Pediatric Eosinophilic Esophagitis.

OBJECTIVES The aim of the study was to determine whether patients with eosinophilic esophagitis (EoE) have lower bone mineral density (BMD) than expected and if bone deficits are more pronounced in subgroups of patients according to comorbidities (atopic disease and joint hypermobility) or treatments (dietary restriction, medication exposure). STUDY DESIGN Retrospective chart review was performed to obtain clinical data, including length of diagnosis, comorbidities, and methods of treatment for patients with EoE ages 3 to 21 years who had a lumbar spine dual-energy x-ray absorptiometry scan performed between 2014 and 2017. BMD was standardized by calculation of age, sex, and race-specific z scores. RESULTS A total of 269 patients met study criteria. The mean BMD z score (-0.55, 95% confidence interval: -0.68, -0.42) was lower than expected (P < 0.0001), and the prevalence of low BMD z score (≤-2.0) was higher than expected (8.5%, 95% confidence interval: 5.2%-11.9%, P < 0.0001). In multivariable regression models, BMD z scores were -0.27 lower among those following an elimination diet and -0.65 lower among those with any lifetime use of a proton pump inhibitor (93% of the sample). There was no association with swallowed steroid use. CONCLUSIONS In our sample, pediatric patients with EoE had a slightly lower BMD z score compared to peers, and the prevalence of low BMD was higher than expected. Taken cautiously given the limitations of our sample, risk factors for bone deficits included any lifetime use of proton pump inhibitor and a restrictive elimination diet, but not swallowed steroid use. Larger prospective studies are needed to better characterize risk factors for low BMD to help inform screening, selection of therapies, and provide appropriate anticipatory guidance for patients with EoE.
Repeated sampling facilitates within- and between-subject modeling of the human sperm transcriptome to identify dynamic and stress-responsive sncRNAs.

Epidemiological studies from the last century have drawn strong associations between paternal life experiences and offspring health and disease outcomes. Recent studies have demonstrated sperm small non-coding RNA (sncRNA) populations vary in response to diverse paternal insults. However, for studies in retrospective or prospective human cohorts to identify changes in paternal germ cell epigenetics in association with offspring disease risk, a framework must first be built with insight into the expected biological variation inherent in human populations. In other words, how will we know what to look for if we don’t first know what is stable and what is dynamic, and what is consistent within and between men over time? From sperm samples from a ‘normative’ cohort of healthy human subjects collected repeatedly from each subject over 6 months, 17 healthy male participants met inclusion criteria and completed donations and psychological evaluations of perceived stress monthly. sncRNAs (including miRNA, piRNA, and tRNA) isolated from mature sperm from these samples were subjected to Illumina small RNA sequencing, aligned to subtype-specific reference transcriptomes, and quantified. The repeated measures design allowed us to define both within- and between-subject variation in the expression of 254 miRNA, 194 tRNA, and 937 piRNA in sperm over time. We developed screening criteria to identify a subset of potential environmentally responsive ‘dynamic’ sperm sncRNA. Implementing complex modeling of the relationships between individual dynamic sncRNA and perceived stress states in these data, we identified 5 miRNA (including let-7f-5p and miR-181a-5p) and 4 tRNA that are responsive to the dynamics of prior stress experience and fit our established mouse model. In the current study, we aligned repeated sampling of human sperm sncRNA expression data with concurrent measures of perceived stress as a novel framework that can now be applied across a range of studies focused on diverse environmental factors able to influence germ cell programming and potentially impact offspring development.
Submarine channel and lobe hidden inside mass-transport deposits in the northern Gulf of Mexico

Abstract Despite numerous subsurface studies of mass-transport deposits (MTDs) using seismic data, internal characters of MTDs at the seismic scale are still not well understood, largely because of the limitation of seismic resolution. This study investigates Miocene-Pliocene MTDs in an understudied, hydrocarbon-rich region of the northern Gulf of Mexico. With the help of quantitative seismic geomorphology techniques, we utilized a high-quality 3D seismic dataset. We document sinuous channel and lobe features hidden within individual MTDs. This provides evidence for considering a seismically-defined MTD unit as amalgamated deposits of multiple events with different flow types (e.g., turbidity currents and cohesive flows), rather than an en masse deposit of a singular event. Additionally, we document an unshielded erosional remnant, which is generated by the bifurcation of a megascour marking the base of an MTD unit. Remnant strata are interpreted as sandy sediment waves. Channel, lobe, and erosional remnant features examined in this study demonstrate the presence of reservoir-prone facies encased within MTD units, forming stratigraphic traps. This research enhances our understanding of the intermingling nature of MTDs and other typical deep-water deposits, and the reservoir potential of MTDs and associated strata.
Transformation-based high-level synthesis of fault-tolerant ASICs

The authors present a transformation-based approach to the high-level synthesis of fault-tolerant application-specific ICs (ASICs) satisfying a given performance constraint but requiring less than proportional increase in hardware over their nonredundant counterparts. They propose a synthesis methodology to exploit hardware minimizing transformations. A simple set of transformations are identified that minimize the fault-tolerance overhead. The selected transformations make the final design resilient to common mode failures. These transformations can be composed to form a rich set of complex transformations. An algorithm is presented to automatically identify structures in a flow graph where transformations can improve hardware utilization, and transformations that suit the structure best are applied. The system has been used to schedule several flow graphs.
A power law network in an evolutionary hawk–dove game

Abstract Evolutionary game theory has attracted the attention of researchers studying game theory as a model of conflict between two players. In this game model, the benefit of an individual player depends on the strategy used by their opponent. Spatial game theory involves the extension of network systems where players can interact with their neighbours, thus expanding the complexity of the system. Cooperation appears to be more dominant in these power-law networks than in the lattices and depends on the network structure. However, little is known about how typical networks emerge using spatial game theories in network systems. Here, I focus on how networks in a spatial hawk-dove game evolve using the connection/disconnection of links. In this study, I develop a novel spatial hawk–dove model that focuses on link evolution. In the proposed model, players connect/disconnect their link with each other, resulting in changing the network structure of an initially regular lattice. In other words, the player sometimes disconnects a link with a neighbour who is a good partner or selects one node as a new partner when the player doubts their position within the local hierarchy. The proposed model generated a characteristic network structure, while demonstrating critical behaviour.
Optimizing Data Intensive Flows for Networks on Chips

A novel framework is proposed to find efficient data intensive flow distributions on Networks on Chip (NoC). Voronoi diagram techniques are used to divide a NoC array of homogeneous processors and ...
GABAA1a Receptors

γ-Aminobutyric acid (GABA) is the most prevalent inhibitory neurotransmitter in the mammalian brain, and it may play an important role in sleep regulation. The effects of GABA are mediated by activation of two classes of receptors, i.e. GABAA and GABAB receptors. GABAA receptors are assumed to have a pentameric glycoprotein structure, composed of different polypeptide subunits and, as a result, are highly heterogeneous. The GABAA1a receptor subclass (previously termed the benzodiazepine BDZ1 receptor) represents approximately half of all GABAA receptors.
Guillain-Barré syndrome after bortezomib therapy in a child with relapsed acute lymphoblastic leukemia.

A 12-year-old male being treated for a high-risk relapsed T-acute lymphoblastic leukemia presented progressive weakness and numbness of both legs after having received a chemotherapy regimen that included bortezomib. Diagnosis of acute Guillain-Barre syndrome-like inflammatory demyelinating polyneuropathy was made following clinical examination, cerebrospinal fluid analysis, electrodiagnostic studies, magnetic resonance imaging, and serum immunoglobulin antibodies to anti-ganglioside. Intravenous immunoglobulin treatment was started, resulting in complete clinical recovery. Although in rare cases, Guillain-Barre syndrome after bortezomib therapy has been reported; this paper suggests that GBS may occur when bortezomib is administered and high‑dose intravenous immunoglobulin lead to a resolution of the symptoms.
Adipose stem cell homing and routes of delivery

Abstract Adipose stem cells (ASCs) are multipotent mesenchymal stem cells that are involved in regenerative tissue repair. Upon injury, a gradient of signals promotes migration and homing of ASCs at the site of injury. Toward applying ASCs for regenerative therapies, several homing strategies are investigated including magnetically guiding ASCs to target tissues upon labeling with magnetic nanoparticles. Alternatively, targeted delivery of ASCs at the site of injury is also assessed. While the intravenous delivery has been tested in both preclinical and clinical studies, efficacy of localized delivery via intraarterial, intraparenchymal, and intramyocardial injections is currently tested for cell-based regenerative therapies.
Voters’ behavior: Probing the salience of Manifestoes, Debates, Ideology and Celebrity Endorsement

The transition from military to democratic rule has inter alia culminated in entrenching elections as a political culture. This has sparked longstanding debate about voting behavior determinants in Ghana. Therefore, this study probes voters behavior infleuncers using a conceptual model anchored on the theory of reasoned action. Data was drawn using questionnaires. Data (n = 401) analysis results using the structural equation modelling technique revealed a significant relationship between celebrity endorsement, ideology, manifesto and debate, and attitude. Further, celebrity endorsement, debate and attitude were revealed to significantly relate voters’ voting intention. Given these outcomes, implications and suggestions for further research, are outlined.
Are deep infections that present before and after 90 days from orthopaedic trauma different? An analysis of the validity of the recent change in CDC criteria for infections.

Abstract Background In 2016, the Centers for Disease Control and Prevention (CDC) changed the time frame for their definition of deep surgical site infection (SSI) from within 1 year to within 90 days of surgery. We hypothesized that a substantial number of infections in patients who have undergone fracture fixation present beyond 90 days and that there are patient factors that can predict who is more likely to present with SSI after 90 days. Methods A retrospective review yielded 452 deep SSI after fracture fixation. These patients were divided into two groups—those infected within 90 days of surgery (308 patients) and those infected beyond 90 days (144 patients). Data were collected on risk factors for infection. Univariate and multiple logistic regression analyses were performed to compare the two groups. A randomly selected control group was used to build infection prediction models for both outcomes. The two outcomes were then modeled against each other to determine whether differences in predictors for early versus late infection exist. Results Of the 452 infections, 144 occurred beyond 90 days (32%). No statistically significant patient factors were found in univariate analysis between the early and late infection groups. The need for flap coverage was the only injury characteristic that differed significantly between groups, with patients in the late infection group more likely to have needed a flap. In models of early versus late infection, there are no statistically significant predictors. When modeled against the control group and directly comparing the two models, predictors for early infection include male sex and fractures of the pelvis, acetabulum, or hip, whereas predictors of late infection include hepatitis C and/or human immunodeficiency virus (HIV) and admission to the intensive care unit (ICU). Conclusion Use of the recent CDC definition will underestimate the rate of actual postoperative infections when applied to orthopaedic trauma patients. Hepatitis C and/or HIV and ICU admission are predictors of late infection, whereas male sex and pelvis, acetabulum, or hip fractures are predictors of early infection. Patients who receive flap coverage may be more likely to present with late infection.
Evaluation of an Integrated Traffic Flow Management Decision Making Approach

Traffic flow management in the United States is currently accomplished through a varied collection of controls such as miles-in-trail restrictions, playbook reroutes, air-space flow programs, and ground delay programs that are implemented independently of one another. An integrated traffic flow management decision-making approach that sequentially schedules and reroutes flights according to actual and forecast weather-induced airspace capacity constraints is described. The study tests the integrated system under 80 six-hour, fast-time simulation experiments. The authors describe the overall decision-making approach, discuss the implemented models, flight schedules, weather scenarios, and airspace capacity constraints, and present results of fast-time simulations used to explore trade-offs between optimization and heuristic-based models, strategic versus tactical flight controls, and system versus fleet preferences.
Random Processes with Evolutionary Power

In a recent paper, Hammond demonstrated a use of the evolutionary power spectral density, which was originally introduced by Priestley, for slowly varying random processes appearing in engineering applications. The purpose herein is to show that the form of input-output relationships derived by Hammond under certain assumed asymptotic forms of the responses is also valid without such restrictions, and that it can be derived in a much more straightforward fashion.
Atmospheric Diffusion Theory

Publisher Summary This chapter outlines the development of the key elements of atmospheric diffusion theory leading to the formulas in common use for carrying out atmospheric diffusion calculations. It introduces the principal ideas and illustrates the important derivations of atmospheric diffusion theory. It also presents the formulas for performing atmospheric diffusion calculations. Lagrangian approach and Eulerian approach are used in the chapter to discuss atmospheric diffusion theory with the help of equations of turbulent diffusion, mean concentration, point source diffusion formulas, Gaussian distribution, Monin–Obukhov length, and steady-state equation.
Multiple Comparison Techniques

In analyzing a linear model we can examine as many single degree of freedom hypotheses as we want. If we test all of these hypotheses at, say, the .05 level, then the (weak) experimentwise error rate (the probability of rejecting at least one of these hypotheses when all are true) will be greater than .05. Multiple comparison techniques are methods of performing the tests so that if all the hypotheses are true, then the probability of rejecting any of the hypotheses is no greater than some specified value, i.e., the experimentwise error rate is controlled.
The professionalization of software engineering and its significance for ethics education

In May of 1993, the Board of Governors of the IEEE-CS established a steering committee for evaluating, planning, and coordinating actions related to establishing software engineering as a profession. In that same year the ACM Council endorsed the establishment of a Commission on Software Engineering. By January of 1994, both societies formed a joint committee "To establish the appropriate set(s) of standards for professional practice of Software Engineering upon which industrial decisions, professional certification, and educational curricula can be based." To accomplish these tasks they made the following recommendations: (1) adopt standard definitions; (2) define required body of knowledge and recommended practices; (3) define ethical standards; and (4) define educational curricula for undergraduate, graduate (MS) and continuing education (for retraining and migration).
Survey of Tall-Fescue Pasture: Correlation of Toxicity of Fusarium Isolates to Known Toxins

Several aspects of fescue foot in cattle suggest that this disease is caused by fungi growing on fescue grass. Certain fungi isolated from winter pasture yield toxins when grown on synthetic medium. Most of these toxin producers belong to the genus Fusarium. All but 1 of the 21 toxic and 7 questionably toxic Fusarium isolates produce either 4-acetamido-4-hydroxy-2-butenoic acid γ-lactone, or 4β, 15-diacetoxy-8α-(3-methylbutyryloxy)-12, 13-epoxytrichothec-9-en-3α-ol, or both.
Life distribution analysis based on Lévy subordinators for degradation with random jumps

For a component or a system subject to stochastic degradation with sporadic jumps that occur at random times and have random sizes, we propose to model the cumulative degradation with random jumps using a single stochastic process based on the characteristics of Levy subordinators, the class of nondecreasing Levy processes. Based on the inverse Fourier transform, we derive a new closed-form reliability function and probability density function for lifetime, represented by Levy measures. The reliability function derived using the traditional convolution approach for common stochastic models such as gamma degradation process with random jumps, is revealed to be a special case of our general model. Numerical experiments are used to demonstrate that our model performs well for different applications, when compared with the traditional convolution method. More importantly, it is a general and useful tool for life distribution analysis of stochastic degradation with random jumps in multidimensional cases. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 483–492, 2015
Natural selection on floral morphology can be influenced by climate

Climate has the potential to influence evolution, but how it influences the strength or direction of natural selection is largely unknown. We quantified the strength of selection on four floral traits of the subalpine herb Ipomopsis sp. in 10 years that differed in precipitation, causing extreme temporal variation in the date of snowmelt in the Colorado Rocky Mountains. The chosen floral traits were under selection by hummingbird and hawkmoth pollinators, with hawkmoth abundance highly variable across years. Selection for flower length showed environmental sensitivity, with stronger selection in years with later snowmelt, as higher water resources can allow translation of pollination success into fitness based on seed production. Selection on corolla width also varied across years, favouring narrower corolla tubes in two unusual years with hawkmoths, and wider corollas in another late snowmelt year. Our results illustrate how changes in climate could alter natural selection even when the primary selective agent is not directly influenced.
PATHWAYS FOR BIOSYNTHESIS OF A BACTERIAL CAPSULAR POLYSACCHARIDE. IV. CAPSULE RESYNTHESIS BY DECAPSULATED RESTING-CELL SUSPENSIONS.

Abstract Juni, Elliot (Emory University, Atlanta, Ga.), and Gloria A. Heym. Pathways for biosynthesis of a bacterial capsular polysaccharide. IV. Capsule resynthesis by decapsulated resting-cell suspensions. J. Bacteriol. 87:461–467. 1964.—Methods were devised for stripping capsules from encapsulated bacteria. By use of stripped resting-cell suspensions of a gram-negative capsule-forming coccus, it was shown that polysaccharide capsule resynthesis depends upon the presence of air and an oxidizable substrate. Capsule resynthesis proceeds linearly with time. For a given quantity of stripped cells, the net amount of polysaccharide capsule synthesized is a linear function of the amount of substrate oxidized. The only factor that appears to limit the extent of capsule synthesis by resting cells is the amount of substrate utilized. A series of photomicrographs of wet mounts made in India ink show the appearance of stripped cells and resynthesized capsules formed during oxidation of pyruvate and glucose by stripped resting-cell suspensions.
Obligatory role for complex I inhibition in the dopaminergic neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)

Administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to mice and nonhuman primates causes a parkinsonian disorder characterized by a loss of dopamine-producing neurons in the substantia nigra and corresponding motor deficits. MPTP has been proposed to exert its neurotoxic effects through a variety of mechanisms, including inhibition of complex I of the mitochondrial respiratory chain, displacement of dopamine from vesicular stores, and formation of reactive oxygen species from mitochondrial or cytosolic sources. However, the mechanism of MPTP-induced neurotoxicity is still a matter of debate. Recently, we reported that the yeast single-subunit nicotinamide adenine dinucleotide (reduced) dehydrogenase (NDI1) is resistant to rotenone, a complex I inhibitor that produces a parkinsonian syndrome in rats, and that overexpression of NDI1 in SK-N-MC cells prevents the toxicity of rotenone. In this study, we used viral-mediated overexpression of NDI1 in SK-N-MC cells and animals to determine the relative contribution of complex I inhibition in the toxicity of MPTP. In cell culture, NDI1 overexpression abolished the toxicity of 1-methyl-4-phenylpyridinium, the active metabolite of MPTP. Overexpression of NDI1 through stereotactic administration of a viral vector harboring the NDI1 gene into the substantia nigra protected mice from both the neurochemical and behavioral deficits elicited by MPTP. These data identify inhibition of complex I as a requirement for dopaminergic neurodegeneration and subsequent behavioral deficits produced by MPTP. Furthermore, combined with reports of a complex I defect in Parkinson's disease (PD) patients, the present study affirms the utility of MPTP in understanding the molecular mechanisms underlying dopaminergic neurodegeneration in PD.
Disruption of PPARβ results in distinct gender differences in mouse brain phospholipid

A homozygous PPARβ-null mouse has been developed in which the ligand-binding domain of the PPARβ receptor is disrupted. Analysis of brains from these animals show that female null mice have a 24 and 17% increase of plasmenylethanolamine and phosphatidylserine and a 9% decrease in the level of phosphatidylinositol when compared to controls. The phospholipid changes found in female null mice were associated with significant increases in esterified 18:1n-9, 20:1n-9, 20:4n-6, and 22:5n-3 in plasmenylethanolamine, 20:1n-9 in phosphatidylinositol, and 18:0, 18:1n-9, 18:3n-6, 20:1n-9, and 20:4n-6 in phosphatidylserine. Increased esterified 18:1n-9, 18:2n-6, 18:3n-6, and 20:1n-9 were also found in the phosphatidylethanolamine fraction despite its cellular content remaining unchanged. Brain phospholipid content in male PPARβ-null mice was not different than controls, but increased levels of 20:1n-9 in the phosphatidylinositol and 18:1n-9 in the phosphatidylserine fractions were observed. No changes were found in the content of brain cholesterol, triglycerides, and free fatty acid in either female or male PPARβ-null mice. These data suggests that the peroxisomal proliferator-activated receptor beta is involved in maintaining fatty acid and phospholipid levels in adult female mouse brain and provides strong evidence suggesting a role for PPARβ in peroxisomal acyl-CoA utilization.
Comparison principles for strongly coupled reaction diffusion equations in unbounded domains

Comparison principles for systems of reaction–diffusion equations in unbounded domains and coupledvia both reaction and diffusion terms are considered. Applications are made to the FitzHugh–Nagumo equations and models of coupled nerve fibres.
Neutron irradiation effect studies at IPNS

Abstract Radiation effect studies at IPNS have continued over the past five years at a relatively low but persistent level. Reduced from an initial facility consisting of a dedicated spallation target system optimized for radiation effects, the current program utilizes two thimbles in the Neutron Scattering Facility. One of the thimbles, located in the H2 beam line, is restricted to ambienttemperature irradiations; the second, located in Vertical Thimble 3, has been outfitted with a vacuum-isolated inner volume that permits irradiation at controlled temperatures up to 600T. This second thimble, called the Radiation Effects Module (REM), began operations in 1992. The energy required to achieve the desired temperature is supplied by electrical heaters on experimental inserts. Since the energy deposited in the thimble from the neutron and gamma fluxes is very low, temperature control in the thimble (independent of IPNS operation) is better than 1°C far superior to any other neutron irradiation facility. The ...
CaMKII-Induced Shift in Modal Gating Explains L-Type Ca2+ Current Facilitation: A Modeling Study

Ca2+/calmodulin-dependent protein kinase II (CaMKII) plays an important role in L-type Ca2+ channel (LCC) facilitation: the Ca2+-dependent augmentation of Ca2+ current (ICaL) exhibited during rapid repeated depolarization. Multiple mechanisms may underlie facilitation, including an increased rate of recovery from Ca2+-dependent inactivation and a shift in modal gating distribution from mode 1, the dominant mode of LCC gating, to mode 2, a mode in which openings are prolonged. We hypothesized that the primary mechanism underlying facilitation is the shift in modal gating distribution resulting from CaMKII-mediated LCC phosphorylation. We developed a stochastic model describing the dynamic interactions among CaMKII, LCCs, and phosphatases as a function of dyadic Ca2+ and calmodulin levels, and we incorporated it into an integrative model of the canine ventricular myocyte. The model reproduces behaviors at physiologic protein levels and allows for dynamic transition between modes, depending on the LCC phosphorylation state. Simulations showed that a CaMKII-dependent shift in LCC distribution toward mode 2 accounted for the ICaL positive staircase. Moreover, simulations demonstrated that experimentally observed changes in LCC inactivation and recovery kinetics may arise from modal gating shifts, rather than from changes in intrinsic inactivation properties. The model therefore serves as a powerful tool for interpreting ICaL experiments.
Beyond google: the invisible web in the academic library

This article analyzes the concept of the Invisible Web and its implication for academic librarianship. It offers a guide to tools that can be used to mine the Invisible Web and discusses the benefits of using the Invisible Web to promote interest in library services. In addition, the article includes an expanded definition, a literature review, and suggestions for ways in which to incorporate the Invisible Web in reference work and library promotion.
Distribution of phytoplankton pigments in the North Pacific Ocean in relation to physical and optical variability

Abstract To investigate phytoplankton distributions in the North Pacific Ocean, samples of suspended particulate material were collected from the upper 300 m during two cruises in 1985 for detailed analysis of algal pigments by high-performance liquid chromatography (HPLC). Transpacific Leg I along 24°N in April and May, crossed three prominent hydrographic features: the California Coastal Current, the North Pacific Central Gyre and Kuroshio Current. Transpacific Leg II, along 47°N in August and September, crossed the Kuroshio extension, the Subarctic Gyre and the North Pacific Current. Individual pigments were partitioned vertically in the water column, showing distinct spatial patterns across the Pacific Ocean which reflected the large-scale circulation. Vertical distributions of phytoplankton pigments displayed consistent patterns over spatial scales of thousands of kilometers. In near-surface, nitrate-rich waters, fucoxanthin was the dominant carotenoid. In nitrate-poor surface waters, zeaxanthin was the dominant carotenoid at the surface, and 19′-hexanoyloxyfucoxanthin and chlorophyll b concentrations were elevated near the base of the euphotic zone. Phacopigment concentrations greater than a few tens of nanograms per liter were never encountered. Based on Principal Component Analysis, station clustered into three general pigment categories which followed specific hydrographic characteristics of oligotrophic, highly productive and transitional regions.
The effects of spatial and temporal factors on the perception of stroboscopic rotation simulations.

In the present two experiments subjects viewed discontinuous, i.e. stroboscopic, simulations of a transparent sphere partially filled with randomly positioned luminous dots and rotating about the y axis in depth. Over a range of stimulus conditions, such simulations elicited coherent sensations of continuous rotation and internal volume of the sphere. By manipulating both spatial and temporal variables in the simulations, it was attempted to define the boundary conditions for which corresponding elements of a simulation are perceptually paired from frame to frame to yield coherent sensations of rotation and depth. The results indicated that the process that matches or pairs corresponding elements in a three-dimensional simulation cannot be identified with the process that matches corresponding elements in similar two-dimensional displays. Furthermore, temporal factors influenced the perception of these simulations more than did spatial factors, and rotation-judgment accuracy and perceived depth were diffe...
Properties and electrokinetic behavior of non-dilute colloidal suspensions

Abstract This paper is a critical review of how the fluid properties (e.g., density, viscosity, conductivity, and permittivity) and behaviors (e.g., electrophoretic motion, electrokinetic aggregation, chaining, and instabilities) depend on colloid volume fraction. The review focuses on electrokinetic flows in aqueous solutions with suspensions on the order of a few percent that are not considered concentrated, yet may exhibit several behaviors distinct from dilute systems such as non-linear dependence on the particle volume fraction and unexpected behavior such as chaining, aggregation, and instabilities. This non-dilute regime is applicable to a variety of emerging applications such as field induced pattern formations in colloidal dispersions, electrophoretic deposition of colloidal films, nanofluid based thermal management, micron resolution particle image velocimetry, and field induced separations in lab-on-a-chip devices. These applications are often treated as dilute when in fact they may contain considerable volume fractions of particles with significant variations in the particle mobility, fluid electrical conductivity and permittivity, as well as the fluid behavior. Original results on electric field induced particle chaining and aggregation as well as fluid instabilities that may develop due to variations in conductivity and permittivity fields are briefly presented.
Weight concerns and smoking: A literature review

Cigarette smoking has established effects on body weight. The effects of weight concerns on smoking initiation, maintenance, cessation, and relapse, however, are less clear. This review shows that weight concerns are related to smoking behavior in complex ways that differ depending on the smoking outcome (initiation, cessation, relapse), gender, and age. Dieting behaviors and general weight concerns appear to be positively related both cross-sectionally and prospectively to smoking in White adolescent females. In adults, weight concerns specific to smoking cessation appear to be higher in current smokers and may have a negative influence on cessation and relapse. General weight concerns, however, do not differ by smoking status, nor do they appear to hinder cessation or promote relapse. Dieting behavior is most prevalent in former smokers, least prevalent in current smokers, and intermediate in never smokers, suggesting that ex-smokers may be dieting to control cessation-related weight gain. Smoking cessation interventions that promote dieting to control weight have not been successful in preventing cessation-related weight gain, nor have they increased smoking cessation rates. Population-based prospective studies are needed to determine the broader significance of weight concerns in relationship to smoking cessation in adults. Efforts to address weight concerns in smoking intervention programs may need to target a small subset of individuals for whom weight control smoking is a significant barrier to cessation.
Role of AMPA and GluR5 kainate receptors in the development and expression of amygdala kindling in the mouse

The role of AMPA and GluR5-containing kainate receptors in the development and expression of amygdala kindling was examined using the selective 2,3-benzodiazepine AMPA receptor antagonist GYKI 52466 [(1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy5H-2,3-benzodiazepine] and the decahydroisoquinoline mixed AMPA receptor and GluR5 kainate receptor antagonist LY293558 {(3S,4aR,6R,8aR)-6-[2-(1(2)H-tetrazole-5-yl)ethyl]decahydroisoquinoline-3-carboxylic acid)}. Administration of GYKI 52466 (5‐ 40 mg/kg, intraperitoneally) and LY293558 (10‐40 mg/kg, intraperitoneally) prior to daily kindling stimulation in mice produced a dose-dependent suppression of the rate of development of behavioral kindled seizure activity and reduced the duration of the stimulation-induced electrographic afterdischarge. In drug-free stimulation sessions after the initial drug-treatment sessions, there was an acceleration in the rate of kindling development compared with the rate during the preceding drug-administration period; the “rebound” rate was also greater than the kindling rate in saline-treated control animals. In fully kindled animals, both GYKI 52466 and LY293558 produced a dose-dependent suppression of evoked seizures (ED50, 19.3 and 16.7 mg/kg, respectively). Although AMPA receptors appear to be critical to the expression of kindled seizures, since kindling development progressed despite the suppression of behavioral seizure activity, AMPA receptors are less important to the kindling process. LY293558 was modestly less effective at suppressing behavioral seizures during kindling and was not superior to GYKI 52466 in retarding the overall extent of kindling development, indicating that GluR5 kainate receptors do not contribute to epileptogenesis in this model. Published by Elsevier Science Ltd.
Freedom of foreign movement, economic opportunities abroad, and protest in non-democratic regimes

Allowing or restricting foreign movement is a crucial policy choice for leaders. We argue that freedom of foreign movement reduces the level of civil unrest under non-democratic regimes, but only i...