bluuebunny/crossref_metadata_2025 huggingface dataset:
Weed Community Response to Saffron–Black Zira Intercropping
Authors: Mesgaran Mohsen B. , Mashhadi Hamid R. , Khosravi Mahmood , Zand Eskandar , Mohammad-Alizadeh Hasan
Published: May 2008

Intercropping is an eco-friendly approach for reducing weed problems through nonchemical methods. Intercrop effects on weed community structure have rarely been studied. A 6-yr study was initiated in 1999 and the response of aboveground weed flora (1999–2002 and 2005) and seed bank (2005) to the intercropping of saffron and black zira, two perennial crops was investigated. Mixtures consisted of 0/100, 25/75, 50/50, 75/25, and 100/0 saffron/black zira ratios, each planted at three densities: 30, 50, and 70 plant m−2. The effect of planting density on weed populations was variable and in most cases not significant. However, mixture ratios caused drastic species compositional changes in the weed community for which univariate and multivariate analyses explored four major associations: (1) weeds that favored a higher ratio of saffron in mixtures (e.g., grasses, field bindweed, pigweeds), (2) weeds that preferred a higher ratio of black zira in mixtures (e.g., Persian speedwell, Brassicaceae complex, Polygoaceae complex, and earthsmoke), (3) weeds that were more abundant in 50/50 mixtures (e.g., Caryophyllaceae complex), and (4) weeds that showed no specific pattern (e.g., common lambsquarterss). Pigweeds, prostrate knotweed, and common lambsquarters dominated the viable seed bank with relative densities of 48, 28, and 8%, respectively. The seed bank of most weed species responded to mixture ratios in a similar manner to those of their corresponding aboveground flora. Seed density decreased as soil depth increased, leading to the accumulation of 66, 22, and 12% of viable seeds in soil layers of 0–5, 5–15 and 15–25 cm, respectively. Greater weed and seed densities were found in more pure stands of black zira. These findings contribute to improving current understanding of crop–weed community structures and may help in developing weed management practices.
Cover Crop Effects on the Activity-Density of the Weed Seed PredatorHarpalus rufipes(Coleoptera: Carabidae)
Authors: Shearin Amanda F. , Chris Reberg-Horton S. , Gallandt Eric R.
Published: May 2008

Cover crop systems were investigated in 2004 and 2005 for their effects on the activity-density (a function of movement and density) of a promising group of weed biocontrol organisms, the ground beetles collectively known as carabids, with particular emphasis on a beneficial carabid speciesHarpalus rufipesDeGeer. MarkedH. rufipesreleased into pea/oat–rye/vetch cover crop plots were more than twice as likely to be recaptured within the same plots as beetles released in nonvegetated fallow plots (18 and 8%, respectively). Marked beetles released into fallow plots were more than twice as likely to leave their plots and be recaptured in pea/oat–rye/vetch plots as vice versa (13 vs. 5%), indicating a clear preference for habitat with vegetative cover. Overall recapture rates were not different between treatments. UnmarkedH. rufipesactivity-density was also higher in pea/oat–rye/vetch compared to fallow plots. Additionally, five cover crop systems, including the fallow and pea/oat–rye/vetch treatments, and two residue management methods (conventional and zone tillage) were investigated from June to August in 2005 for their effects onH. rufipesactivity-density. Corn was planted in 2005 into residues of the five cover crop systems grown in 2004.H. rufipesactivity-density was higher in zone and conventionally tilled corn planted in pea/oat–rye/vetch residues and conventionally tilled corn planted in red clover/oat residues than in any other cover crop and residue management combination. Pea/oat–rye/vetch cover crop systems are apparently beneficial forH. rufipesduring the cover crop year as well as in subsequent crops planted into this cover crop's residues. This system was not the least disturbed system but, based on the number of tillage events, represented a medium level of disturbance among the various systems. Thus, some level of disturbance might be beneficial forH. rufipes, but how and when that soil disturbance occurs requires further research to determine the best means of conserving this species.
A Common Genetic Basis in Sweet Corn Inbred Cr1 for Cross Sensitivity to Multiple Cytochrome P450-Metabolized Herbicides
Authors: Nordby Jonathan N. , Williams Martin M. , Pataky Jerald K. , Riechers Dean E. , Lutz Joseph D.
Published: May 2008

Nicosulfuron, mesotrione, dicamba plus diflufenzopyr, and carfentrazone are postemergence herbicides from different chemical families with different modes of action. An association between the sensitivity of sweet corn to these herbicides was observed when 143 F3 : 4families (F4plants) derived from of a cross between Cr1 (sensitive inbred) and Cr2 (tolerant inbred) were evaluated in greenhouse trials. The ratio of tolerant : segregating : sensitive families was not significantly different from a 3 : 2 : 3 ratio, which would be expected if a single gene conditioned herbicide response. Families cosegregated for responses to these herbicides. In field studies with 60 F3 : 5families in 2005 and 120 F3 : 5families in 2007, responses to these herbicides and foramsulfuron and primisulfuron were associated. Responses to bentazon in field trials were similar to the aforementioned herbicides for tolerant families, but differences were noted for families that were sensitive or segregated for responses to nicosulfuron, foramsulfuron, primisulfuron, mesotrione, dicamba plus diflufenzopyr, and carfentrazone. The gene(s) affecting herbicide sensitivity in Cr1 maps to the same region of chromosome 5S as a previously sequenced cytochrome P450 gene, where alleles previously designatednsf1andben1were associated with sensitivity to nicosulfuron and bentazon and appear to be the result of a 392–base-pair insertion mutation. This work supports the hypothesis that a single recessive gene or closely linked genes in the sweet corn inbred Cr1 condition sensitivity to multiple cytochrome P450 enzyme-metabolized herbicides.
Factors Affecting Germination and Emergence of Dame's Rocket (Hesperis matronalis)
Authors: Susko David J. , Hussein Yara
Published: May 2008

Laboratory experiments were conducted to determine the effects of temperature, light, cold stratification, dry storage, solution pH, solution osmotic potential, and planting depth on germination and emergence of dame's rocket. Maximal germination (> 80%) of fresh seeds occurred at alternating temperatures ≥ 25/15 C in both alternating light/dark and continuous darkness. However, < 10% of seeds germinated at or below 20/10 C, with lower germination in the presence of light than in darkness. Cold stratification at 4 C for 4 to 16 wk enhanced germination at low alternating temperatures (≤ 20/10 C), but depressed germination at warm temperature regimes (≥ 25/15 C). After 1 yr of dry storage (after-ripening), germination exceeded 94% and did not differ significantly among temperature regimes. Germination exceeded 60% in solutions with pH 3 to 10. Germination was reduced below 50% in solutions with osmotic potentials below −0.6 MPa. Percent emergence was greater than 56% at burial depths in soil of 0 to 5 cm, with maximal emergence (93 to 99%) at 0 to 2 cm. Dame's rocket seeds possess non-deep physiological dormancy at maturity, but when dormancy is alleviated, the seeds are capable of germinating in a variety of climatic and edaphic conditions.
Genetic Variation in Invasive Populations of Yellow Toadflax (Linaria vulgaris) in the Western United States
Authors: Ward Sarah M. , Reid Scott D. , Harrington Judy , Sutton Jason , Beck K George
Published: May 2008

Intraspecific genetic variation may contribute significantly to invasiveness and control problems, but has been characterized to date in relatively few invasive weed species. We examined 56 intersimple sequence repeat (ISSR) loci in 220 individuals from 11 invading populations of yellow toadflax sampled across five western states. All populations showed high levels of genetic diversity. Estimated values for Shannon's diversity measure ranged from 0.217 to 0.388, and for expected heterozygosity from 0.178 to 0.260. Nei's total gene diversity index (HT), on the basis of all individuals across all populations, was 0.267. Partitioning of genetic variance using analysis of molecular variance revealed 1.7% of genetic variation among regional population groups, 29.1% among populations within groups, and 69.2% within populations, consistent with expectations for an outcrossing species but suggesting little geographic differentiation. Pairs of adjacent individuals identical at all ISSR loci that appeared to be ramets of a single clone were detected in only one population. This indicates that patch expansion in yellow toadflax is driven more by sexual reproduction via seed than by rhizomatous clonal spread, at least at the spatial scale of sampling for this study. Eight populations had significant values for Mantel'sRat P = 0.05, suggesting some fine-scale positive genetic structuring, possibly from restricted gene flow. Population clustering on the basis of Nei's genetic distance between populations and unweighted pair group method with arithmetic mean did not reflect geographic location. It is likely that multiple introductions of this species have occurred across the Intermountain West, followed by extensive genetic recombination. High levels of genetic diversity within yellow toadflax populations pose management challenges, as already seen in reports of variable response to herbicide application and limited impacts of biocontrol agent releases.
Barriers to Care-Seeking for Depressed African Americans
Authors: Cruz Mario , Pincus Harold Alan , Harman Jeffreys , Reynolds Charles F. , Post Edward P.
Published: May 2008

Objective:

We explored perceived barriers to mental health care-seeking for depressed, low-income African Americans who are already engaged in psychotherapy.

Methods:

During a trial to improve psychotherapy appointment adherence, we asked all African-American participants, “Research shows African Americans with emotional or psychological problems use mental health services at half the rate of whites with similar problems. Why do you think that is?” Responses were captured verbatim.

Results:

Of 53 African Americans enrolled, 43 completed the study. We analyzed their responses in the hope of identifying modifiable responses. We used qualitative analytic methods, with four raters achieving consensus in coding responses into 13 thematic categories. Stigma was the most frequent response, followed by dysfunctional coping behavior, shame, denial, and “don't know.”

Conclusion:

While this study supports several barriers to care-seeking reported in the extant literature, our data also underscores the prominence of shame and denial, together with their complex interrelationships to public stigma and depression, respectively. Future research should assess the relationships between these factors to mental health care-seeking behavior in low-income African Americans and ways of modifying them.
Reduced Relative Frequency of Knowledge of Results without Visual Feedback in Learning a Golf-Putting Task
Authors: Ishikura Tadao
Published: May 2008

This study examined the effects of reduced relative frequency of knowledge of results (KR) on learning to putt in golf. Participants (19 men and 15 women) putted a golf ball, stopping the ball on a line at a distance of 3.5 m from the starting position, which included an uphill portion. After a pretest, participants were assigned as they arrived in balanced order by sex to one of two groups (100% KR, 33% KR) and practiced 60 trials. Those in the 100% KR group performed the task in its natural context, while others assigned to the 33% KR were shown the location of the putted ball after every third trial. All participants then performed a posttest and two retention tests, done 10 min. and 24 hr. after the posttest. Analysis at posttest showed each group had a constant error and an absolute constant error (|CE|) less than those at pretest. Also, in the retention test conducted the following day, the constant error of the 33% KR group was less than that of the 100% KR group. Third, in the posttest and both retention tests, the |CE| of the 100% KR group was larger than that of the 33% KR group. These results suggest that reduced relative frequency of knowledge of results is effective in learning the accuracy of the golf putt.
Development of Children's Mental Representations: Effects of Age, Sex, and School Experience
Authors: Coulbeau Ludovic , Royer Pierre , Brouziyne Majid , Dosseville Fabrice , Molinaro Corinne
Published: May 2008

In the present study mental representations in drawings by 158 young children, ages 2 ½ to 6 yr. old were analysed. The aim was to investigate whether the accuracy of mental representations increased with age and how this development progressed. Also tested were whether the inferred mental representations differed for boys and girls and whether preschool experience affected the drawings. As expected, mental representation increased in complexity with age as measured by Goodenough's score, and girls' mental representations (drawings) were significantly more elaborate than boys. Moreover, attending school early seemed to affect mental representations of the 3-yr.-olds but not the 4-yr.-olds. Results are discussed in terms of internal and external factors in mental representation in drawing a man.
Analysis of Toddlers' Gait after Six Months of Independent Walking to Identify Autism: A Preliminary Study
Authors: Esposito Gianluca , Venuti Paola
Published: May 2008

This research analyzed gait in toddlers and tested the hypothesis that movement can be used as an early indicator of Autistic Disorder. It was proposed that an early identification method could indicate differences in the gait of toddlers with autism as opposed to those with typical development or with mental retardation. Observational methods were applied to retrospective home videos of 42 children after 6 mo. of independent walking. In particular, the Walking Observation Scale was used, which includes 11 items that analyze gait through three axes of foot movements, arm movements, and global movements. Analysis showed different distributions for the three groups, i.e., the autistic group differed from the other two on scores for the Walking Observation Scale and each axis. After 6 mo. of independent walking, different patterns in gait among groups were evident. These results agree with recently published evidence which acknowledges the importance of movement as an early indicator for differential diagnosis of autism.
Power Spectrum Characteristics of Sway Position and Velocity of the Center of Pressure during Static Upright Posture for Healthy People
Authors: Demura Shinichi , Kitabayashi Tamotsu , Noda Masahiro
Published: May 2008

This study assessed sex and individual differences in sway-position and velocity power spectra and reliability of power frequency with 30 health young people. The body sway for 1 min. was measured twice over a 1-min. rest. There were no significant sex differences in the spectra. Frequency bands with a large coefficient of variance over 10.0 appeared up to 0.6 Hz. 75% relative accumulated power frequency appeared at 1.10–1.23 Hz in the position and at 2.00–3.05 Hz in the velocity spectra. Most power was in the low frequency band (A and B frequency intervals) of the international standard. Relative accumulated power frequency of position and velocity power spectra was reasonably reliable. It may be necessary to establish a new evaluation frequency interval by direction of sway-position and velocity using relative accumulated power frequency for healthy people.
Validity Study of the Moral Judgment Test in Physical Education: Development and Preliminary Validation
Authors: Mouratidou Katerina , Chatzopoulos Dimitrios , Karamavrou Sofia
Published: May 2008

Teaching ethical behavior is an aspect of physical education. The purpose of the study was to present the construction and to estimate validity of a test which assesses physical education students' moral judgment, the Moral Judgment Test in Physical Education. The sample comprised 281 male and female participants (95 in Grades 7 to 9, 92 in Grades 10 to 12, and 94 university students), who completed Lind's Moral Judgment Test and the Moral Judgment Test-PE version. The validity of the latter was assessed using four criteria of Lind's moral theory. Analysis indicated that the Moral Judgment Test–PE had adequate construct validity and correlated positively, although relatively weakly, with the original test, so the new version has sufficient construct validity to be used in physical education.
Who Returns to Prison? A Survival Analysis of Recidivism among Adult Offenders Released in Oklahoma, 1985 – 2004
Authors: Spivak Andrew L. , Damphousse Kelly R.
Published: May 2008

Identifying and evaluating the influence of factors that predict offenders' post-release performance is central to the study of recidivism. In this project, 60,536 adult prison releases from the Oklahoma Department of Corrections between 1985 and 1999 were tracked until May 31, 2004. Recidivism was measured as a return to incarceration and cases were analyzed with a Cox Proportional Hazards Survival Regression, which allowed for the assessment of the relative hazards of returning to prison over time. Predictor variables included offense type, release type (probation, parole, discharge), number of prior incarcerations, sentence length, time served in prison, security classification, education, age, sex, and race. A greater hazard of recidivism was associated with being a property offender (as opposed to a drug, violent, or sex offender), being released to probation (as opposed to being discharged), having a violent offense history, having a greater number of past incarcerations, and being young, male, and a racial minority. Sentence length and time served in prison had weak (but significant) associations with recidivism, while security classification and proportion of sentence served (as proxies for institutional performance) indicated modestly positive, significant relationships.
Cross‐Species Genetic Toxicity Assessment Accomplished by Flow Cytometric Analysis of Blood
Authors: Bemis Jeffrey C. , Torous Dorothea K. , Tometsko Carol R. , Dertinger Stephen D.
Published: May 2008

The formation of micronuclei in blood cells has been an established indicator of genotoxicity for decades. Standard microscopy methods are time‐consuming and lack the objectivity that fully automated methods can provide. The ability of flow cytometric technology to rapidly and objectively survey thousands of cells for micronuclei can significantly improve the value of this endpoint. In addition, since many more cells can be scored, and specific populations can be targeted, species that historically have been difficult to obtain micronucleus data from, such as humans, can now be readily evaluated using this methodology. This unit describes a procedure for fixation, staining, and analysis of blood samples using materials supplied in MicroFlow kits (Litron Laboratories) and a single‐laser flow cytometer. This methodology provides a reliable, robust assessment of chromosome damage that is used in basic science research as well as drug‐safety screening programs at large pharmaceutical and chemical companies. Curr. Protoc. Toxicol. 36:2.14.1‐2.14.15. © 2008 by John Wiley & Sons, Inc.
Analysis of Modulation of Immunoglobulin Gene Expression
Authors: Sulentic Courtney E. W.
Published: May 2008

Immunoglobulins (Ig) are critical in maintaining host immunity to a variety of pathogens. Regulation of Ig expression is a complex process involving transcriptional regulation of different Ig gene loci by many transcription factors and transcriptional regulatory regions. This complexity suggests many possible molecular targets for immunotoxicants. Therefore, thorough evaluation of chemical‐induced modulation of Ig expression may necessitate multiple experimental approaches evaluating: (1) number of B cells secreting antibodies by antibody‐forming cell response or plaque assay; (2) concentration of total secreted antibodies by enzyme‐linked immunosorbent assay (ELISA); (3) cellular proliferation and viability by cell count measurements, [3H] thymidine incorporation, and trypan blue exclusion; (4) Ig mRNA expression by quantitative real‐time reverse transcriptase–polymerase chain reaction (RT‐PCR); (5) transcriptional activity of specific Ig regulatory regions by reporter gene analysis; and (6) transcription factor binding to specific Ig regulatory regions by electrophoretic mobility shift (EMSA) and chromatin immunoprecipitation (ChIP). These experimental approaches are discussed in the unit, with detailed description of EMSA, EMSA‐western analysis, and isolation of nuclear protein. Curr. Protoc. Toxicol. 36:18.14.1‐18.14.21. © 2008 by John Wiley & Sons, Inc.
Neutral Red Uptake Cytotoxicity Tests for Estimating Starting Doses for Acute Oral Toxicity Tests
Authors: Stokes William S. , Casati Silvia , Strickland Judy , Paris Michael
Published: May 2008

In vitro cytotoxicity assays can be used as alternative toxicity tests to reduce the total number of animals needed for acute oral toxicity tests. This unit describes two methods for determining the in vitro cytotoxicity of test substances using neutral red uptake (NRU) and using the in vitro data to determine starting doses for in vivo acute oral systemic toxicity tests, e.g., the up‐and‐down procedure or the acute toxic class method. The use of the NRU methods to determine starting doses for acute oral toxicity tests may reduce the number of animals required, and for relatively toxic substances, this approach may also reduce the number of animals that die or require humane euthanasia due to severe toxicity. An interlaboratory validation study has demonstrated that the methods are useful and reproducible for these purposes. Two standardized protocols provide details for performing NRU tests with rodent and human cells. Curr. Protoc. Toxicol. 36:20.4.1‐20.4.20. © 2008 by John Wiley & Sons, Inc.
Affinity Purification of Natural Ligands
Authors: Luong John H.T. , Scouten William H.
Published: May 2008

Immobilization of proteins, nucleic acids, and other bioligands is not always straightforward since they are often large molecules with numerous chemically reactive groups that can all participate in the immobilization process through physical adsorption, ionic binding, or covalent linkage. Protocols for some of the most frequently used matrix‐activation systems are described in this unit. For agarose, protocols are given for cyanogen bromide, p‐nitrophenyl chloroformate, tresyl chloride, and cyanuric chloride. Tosyl chloride is used to activate cellulose, and cyanuric chloride is also used to activate aminopropyl silica gel. Activation of magnetic beads with cyanogen bromide is described, and a protocol is provided for reacting the aldehyde groups of glyoxal agarose beads with the primary amine groups of ligands, with subsequent reduction of the formed Schiff base to yield a stable matrix‐ligand bond. Curr. Protoc. Protein Sci. 52:9.3.1‐9.3.22. © 2008 by John Wiley & Sons, Inc.
Membrane‐Based Yeast Two‐Hybrid System to Detect Protein Interactions
Authors: Lentze Nicolas , Auerbach Daniel
Published: May 2008

The classical yeast two‐hybrid system and its modifications have been successfully used over the past decade to investigate interactions between most classes of proteins expressed in a given cell or tissue. However, some proteins (e.g., integral membrane proteins or nuclear proteins) are relatively difficult to investigate by standard yeast two‐hybrid methods either because they are retained at cellular membranes or they activate the system in the absence of a true protein interaction. The membrane‐based yeast two‐hybrid (MbY2H) system presented in this unit overcomes some of these limitations. It is based on the split‐ubiquitin protein complementation assay and detects protein interactions directly at the membrane, thereby allowing the use of full‐length integral membrane proteins and membrane‐associated proteins as baits to hunt for novel interaction partners. A simple modification also allows the use of proteins that are self‐activating in a classical yeast two‐hybrid system (e.g., acidic proteins and many transcription factors). Like the yeast two‐hybrid system, the MbY2H system can also be used for interaction discovery by screening complex cDNA libraries for novel interaction partners. Curr. Protoc. Protein Sci. 52:19.7.1‐19.7.28. © 2008 by John Wiley & Sons, Inc.
Assessment of Lymphocyte Development in Radiation Bone Marrow Chimeras
Authors: Spangrude Gerald J.
Published: May 2008

Transplantation of marrow between mouse strains congenic for CD45 after lethal irradiation establishes hematopoiesis driven by genetically marked cells in recipient animals. After several weeks, peripheral blood or primary and secondary lymphoid organs of transplant recipients can be evaluated for the presence of donor‐derived cells. Two‐ or three‐color flow cytometry can be used to identify the progeny of transplanted cells, to document their cell‐surface phenotypes, and to follow development of T, B, and myeloid lineages in vivo. Curr. Protoc. Immunol. 81:4.6.1‐4.6.9. © 2008 by John Wiley & Sons, Inc.
Creation of “Humanized” Mice to Study Human Immunity
Authors: Pearson Todd , Greiner Dale L. , Shultz Leonard D.
Published: May 2008

“Humanized” mice are a promising translational model for studying human hematopoiesis and immunity. Their utility has been enhanced by the development of new stocks of immunodeficient hosts, most notably mouse strains such as NOD‐scid IL2rγnull mice that lack the IL‐2 receptor common gamma chain. These stocks of mice lack adaptive immune function, display multiple defects in innate immunity, and support heightened levels of human hematolymphoid engraftment. Humanized mice can support studies in many areas of immunology, including autoimmunity, transplantation, infectious diseases, and cancer. These models are particularly valuable in experimentation where there is no appropriate small animal model of the human disease, as in the case of certain viral infections. This unit details the creation of humanized mice by engraftment of immunodeficient mice with hematopoietic stem cells or peripheral blood mononuclear cells, provides methods for evaluating engraftment, and discusses considerations for choosing the appropriate model system to meet specific goals. Curr. Protoc. Immunol. 81:15.21.1‐15.21.21. © 2008 by John Wiley & Sons, Inc.
The K/BxN Arthritis Model
Authors: Monach Paul A. , Mathis Diane , Benoist Christophe
Published: May 2008

Mice expressing both the T cell receptor (TCR) transgene KRN and the MHC class II molecule Ag7 (K/BxN mice) develop severe inflammatory arthritis, and serum from these mice causes a similar arthritis in a wide range of mouse strains, due to autoantibodies recognizing glucose‐6‐phosphate isomerase (GPI). K/BxN transgenic mice have been useful for investigating the development of autoimmunity, and the serum transfer model has been particularly valuable in eliciting mechanisms by which anti‐GPI autoantibodies induce joint‐specific inflammation. This unit describes detailed methods for the maintenance of a K/BxN colony, induction of arthritis by serum transfer, clinical evaluation of arthritis, and measurement of anti‐GPI antibodies. Curr. Protoc. Immunol. 81:15.22.1‐15.22.12. © 2008 by John Wiley & Sons, Inc.
Paired Receptor Systems of the Innate Immune System
Authors: Yamada Eriko , McVicar Daniel W.
Published: May 2008

This appendix describes paired receptors involved in the innate immune system. “Paired Receptors” are defined as families of related membrane proteins that show the following characteristics: (1) they are encoded by different genes, but located as a gene cluster on a given chromosome; (2) they have significant homology within their extracellular domains; (3) they are expressed on overlapping immune populations; and (4) they are confirmed to have both activating and inhibitory members. For simplicity in nomenclature, the authors used the official gene nomenclature provided by NCBI and listed all other names in the alias field. Paired receptor information related to both mouse and human systems is included, as some families exist in both species whereas others are important in the study of either human or murine models of disease. Curr. Protoc. Immunol. 81:A.1X.1‐A.1X.25. © 2008 by John Wiley & Sons, Inc.
Expansion of Human Embryonic Stem Cells In Vitro
Authors: Costa Magdaline , Sourris Koula , Hatzistavrou Tanya , Elefanty Andrew G. , Stanley Edouard G.
Published: May 2008

This unit describes a protocol for the large‐scale expansion of karyotypically normal human embryonic stem cells (hESCs). hESCs can be maintained indefinitely as dense colonies that are mechanically cut into pieces, which are subsequently transferred to fresh organ culture dishes seeded with primary mouse embryonic fibroblasts (MEFs). hESCs can also be enzymatically passaged (bulk culture); however, over time, this style of culturing may lead to the acquisition of chromosomal abnormalities. Nevertheless, enzymatic passaging can be used for short periods (up to 25 passages) without the appearance of cells with abnormal karyotypes. Curr. Protoc. Stem Cell Biol. 5:1C.1.1‐1C.1.7. © 2008 by John Wiley & Sons, Inc.
Differentiation of Mouse Embryonic Stem Cells to Spinal Motor Neurons
Authors: Wichterle Hynek , Peljto Mirza
Published: May 2008

Controlled differentiation of embryonic stem (ES) cells into clinically relevant cell types is a fundamental goal of stem cell research. This unit describes one of the most efficient protocols for conversion of mouse ES cells into a defined type of nerve cells, the spinal motor neurons. ES cells are separated from feeder mouse embryonic fibroblasts and aggregated to form embryoid bodies (EBs). Two days after the withdrawal of growth factors, EBs reach a stage at which they are responsive to patterning signals and can be effectively induced with retinoic acid (RA) to differentiate into spinal nerve cells. Nascent neural cells become responsive to the ventralizing signal sonic hedgehog (Hh) that controls expression of ventral spinal progenitor markers and initiates the genetic program of motor neuron differentiation. Curr. Protoc. Stem Cell Biol. 5:1H.1.1‐1H.1.9. © 2008 by John Wiley & Sons, Inc.
Biological Sand Filters: Low‐Cost Bioremediation Technique for Production of Clean Drinking Water
Authors: Lea Michael
Published: May 2008

Approximately 1.1 billion people in rural and peri‐urban communities of developing countries do not have access to safe drinking water. The mortality from diarrheal‐related diseases amounts to ∼2.2 million people each year from the consumption of unsafe water. Most of them are children under 5 years of age—250 deaths an hour from microbiologically contaminated water. There is conclusive evidence that one low‐cost household bioremediation intervention, biological sand filters, are capable of dramatically improving the microbiological quality of drinking water. This unit will describe this relatively new and proven bioremediation technology's ability to empower at‐risk populations to use naturally occurring biology and readily available materials as a sustainable way to achieve the health benefits of safe drinking water. Curr. Protoc. Microbiol. 9:1G.1.1‐1G.1.28. © 2008 by John Wiley & Sons, Inc.
Laboratory Maintenance of Ehrlichia chaffeensis and Ehrlichia canis and Recovery of Organisms for Molecular Biology and Proteomics Studies
Authors: Cheng Chuanmin , Ganta Roman R.
Published: May 2008

Tick‐borne illnesses are emerging as a major concern for human health in recent years. These include the human monocytic ehrlichiosis caused by the Amblyomma americanum tick‐transmitted bacterium, Ehrlichia chaffeensis; human ewingii ehrlichiosis caused by Ehrlichia ewingii (also transmitted by A. americanum ticks); and human granulocytic anaplasmosis caused by the Ixodes scapularis tick‐transmitted pathogen, Anaplasma phagocytophilum. Likewise, tick‐borne rickettsial pathogens are also a major concern to the health of various vertebrates including dogs, cattle, and several wild animals. In vitro–cultured pathogens grown in a vertebrate host cell and a tick cell culture system will be useful in studies to understand the pathogenic differences as well as to perform experimental infection studies and to generate large quantities of purified antigens. In this unit, methods for culturing E. chaffeensis and Ehrlichia canis (a canine monocytic ehrlichiosis pathogen) in cell lines to represent vertebrate and tick hosts are described. The unit also includes methods useful in purifying bacteria from the host cells and to evaluate proteins by 2‐D gel electrophoresis and western blotting. Curr. Protoc. Microbiol. 9:3A.1.1‐3A.1.21. © 2008 by John Wiley & Sons, Inc.
Analysis of Bacterial Membrane Proteins Produced During Mammalian Infection Using Hydrophobic Antigen Tissue Triton Extraction (HATTREX)
Authors: Crother Timothy R. , Nally Jarlath E.
Published: May 2008

Hydrophobic antigen tissue Triton extraction (HATTREX) provides a method to extract and identify hydrophobic bacterial membrane proteins from host‐infected tissues. The non‐ionic detergent Triton X‐114 is used to solubilize host‐infected tissues at 4°C. Subsequent phase partitioning of Triton X‐114 extracted material at 37°C results in a “detergent poor” aqueous phase and a “detergent rich” detergent phase. While soluble proteins partition to the aqueous phase, hydrophobic proteins, such as proteins of the outer and inner membranes, can be found in the detergent phase. Characterization of the detergent phase sample provides insights into the proteome of bacterial membranes during infection. Curr. Protoc. Microbiol. 9:12.1.1‐12.1.5. © 2008 by John Wiley & Sons, Inc.
Laboratory Maintenance and Cultivation of Bacteroides Species
Authors: Bacic Melissa K. , Smith C. Jeffrey
Published: May 2008

Bacteroides species are Gram‐negative, obligate anaerobic bacteria. They are the predominant indigenous bacterial species in the human intestinal tract, where they play an important role in the normal physiology of the host, but they can also be significant opportunistic pathogens. The fact that these are obligate anaerobes is the prevailing feature that affects the methodology used for their cultivation. Several techniques are described for anaerobic culturing; the anaerobic glove box and anaerobic jars are the two techniques most adaptable to a range of research needs. Straightforward methods are presented for propagation on solid media and in broth cultures, and for the long‐term storage and maintenance of stock cultures. The Bacteroides species are saccharolytic, which is the second feature of their physiology that impacts cultivation methodology. Several flexible media formulations, including a defined minimal media, are provided that allow the researcher to choose the carbon source best suited for his or her work. Curr. Protoc. Microbiol. 9:13C.1.1‐13C.1.21. © 2008 by John Wiley & Sons, Inc.
Studies on Electrophilic Interaction of 2,3‐Allenols with Electrophilic Halogen Reagents: Selective Synthesis of 2,5‐Dihydrofurans, 3‐Halo‐3‐alkenals, or 2‐Halo‐2‐alkenyl Ketones
Authors: Li Jing , Fu Chunling , Chen Guofei , Chai Guobi , Ma Shengming
Published: May 2008

The reaction of primary 2,3‐allenols with iodine (I2) afforded 2,5‐dihydrofurans while that of readily available 1‐aryl or 1‐methyl substituted 2,3‐allenols with bromine (Br2), N‐bromosuccinimide (NBS), I2 or N‐iodosuccinimide (NIS) formed the not easily available but synthetically useful 3‐halo‐3‐alkenals and 2‐halo‐2‐alkenyl ketones with good selectivity and yields via a sequential electrophilic interaction of X+ with the allene moiety, 1,2‐aryl or 1,2‐proton shift, and H+ elimination process.
Chiral 1,2,3,4‐Tetrahydro‐1‐naphthylamine‐Derived Phosphine‐Phosphoramidite Ligand (THNAPhos): Application in Highly Enantioselective Hydrogenations of Functionalized CC Bonds
Authors: Qiu Min , Hu Xiang‐Ping , Wang Dao‐Yong , Deng Jun , Huang Jia‐Di , Yu Sai‐Bo , Duan Zheng‐Chao , Zheng Zhuo
Published: May 2008

We have recently reported a new chiral 1,2,3,4‐tetrahydro‐1‐naphthylamine‐derived phosphine‐phosphoramidite ligand, (Rc,Ra)‐THNAPhos, that is highly efficient in the rhodium‐catalyzed asymmetric hydrogenation of a broad range of α‐enol ester phosphonates. To further demonstrate the utility of THNAPhos in asymmetric hydrogenation, in this paper, we describe its new application in the asymmetric hydrogenation of α‐dehydroamino acid esters, enamides, dimethyl itaconate and α‐enamido phosphonates. The results disclosed that the Rh/(Rc,Ra)‐THNAPhos complex is highly effective for the enantioselective hydrogenation of these kinds of functionalized CC olefins, affording the corresponding hydrogenation product in excellent enantioselectivities (normally over 99% ee).
Dietary intake, overweight status, and perceptions of food insecurity among homeless Minnesotan youth
Authors: Smith Chery , Richards Rickelle
Published: May 2008

Youth, 9–18 years (n = 202), living in homeless shelters in Minneapolis, Minnesota, were assessed for height, weight, dietary intake, and perceptions of food insecurity. Perceptions of food security were measured by asking youth to respond to the statements (1) “There are times when we do not have enough food in the house,” (2) “I go to bed hungry at night,” (3) “I do not get enough to eat at home,” and (4) “Have you ever had to miss a meal (or not been able to eat) because there was no food at home?” Additionally, questions evaluated coping mechanisms used by children to ward off hunger. Fifty‐five percent of the children reported not enough food in the house and 25% reported going to bed hungry. Youth had inadequate intakes of vitamin D, calcium, and potassium and the majority consumed less than the estimated average requirements (EAR) for vitamins A, C, and E, phosphorus, folate, and zinc. Fruits, vegetables, and dairy were also consumed below recommended levels. Forty‐five percent of boys and 50% of girls were at risk‐for‐overweight or were overweight. Overeating, eating anything, eating disliked foods, and eating at the homes of family and friends were identified as strategies to cope with food insecurity. Overeating when food is available may explain why we see a hunger‐obesity paradigm to the magnitude that we do among the poorest Americans. These strategies protect children from the immediate negative associations of poverty and hunger, but they may contribute to long‐term weight problems currently found in the US. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
The effect of menarcheal age on anthropometric, limb length, and bone measures in Hutterite and non‐Hutterite women
Authors: Grimsrud Courtney , Binkley Teresa , Specker Bonny
Published: May 2008

The age women reach menarche may affect bone length and mass. Some studies show an earlier menarcheal age (MA) results in a shorter stature and increased body fat. We hypothesized that Hutterite women have a shorter height and limb length, but greater bone mass and areal bone mineral density (aBMD) than non‐Hutterites. Results are from a secondary analysis of 344 (198 Hutterite) healthy, pre‐menopausal women aged 20−40 years who participated in the South Dakota Rural Bone Health Study. Bone measures were obtained by DXA (spine, hip and total body) and pQCT (4 and 20% distal radius). MA correlated with year of birth (r = −0.10, P = 0.08) indicating a trend toward a younger MA for women born in more recent years. MA was inversely associated with current weight (r = −0.11, P < 0.05), percent body fat (r = −0.16, P < 0.01), femoral neck BMC (r = −0.18, P = 0.003), femoral neck aBMD (r = −0.21, P < 0.001), hip aBMD (r = −0.22, P < 0.001) and trabecular volumetric BMD (vBMD) (r = −0.14, P = 0.03). Hutterite women had a younger MA than non‐Hutterite women (12.3 ± 1.3 vs. 13.0 ± 1.3 yr, P < 0.001). In final regression models controlling for diet and activity patterns, Hutterite compared to non‐Hutterite women had shorter standing height (162 ± 0.4 vs. 166 ± 0.4 cm, P < 0.001), forearm length (258 ± 0.8 vs. 261 ± 0.9 mm, P = 0.04); and leg length (76 ± 0.2 vs. 77 ± 0.3 cm, P < 0.01) as hypothesized, but MA did not predict these outcomes. In conclusion, younger MA in Hutterite women did not explain their shorter standing height and limb lengths, but total hip aBMD was inversely associated with MA and greater in Hutterite than non‐Hutterite women. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Workplace violence against adolescent workers in the US
Authors: Rauscher Kimberly J.
Published: May 2008

Background

Workplace violence is a significant problem yet most research on this topic has focused on adults. Despite facing numerous employment conditions that raise their risk for workplace violence, adolescent workers have received inadequate attention.

Methods

Survey data from 1,171 US students ages 14–17 were analyzed using descriptive statistics to investigate the incidence and perpetrators of physical attacks, verbal threats, and sexual harassment.

Results

Nearly one‐third of respondents experienced some form of workplace violence: 25% verbally threatened, 10% physically attacked, and 10% sexually harassed. Significant demographic differences were found. The most common perpetrators of physical attacks and verbal threats were customers while sexual harassment most often came from co‐workers.

Conclusions

Many working adolescents, most with only a fewyears work experience, have already suffered workplace violence. As youth are likely to be more vulnerable to its effects, developing workplace violence prevention strategies that target adolescent workers should be made a priority. Am. J. Ind. Med. 51:539–544, 2008. © 2008 Wiley‐Liss, Inc.
Thermally stimulated depolarization current and space charge measurements on low‐density polyethylene: Influence of the presence of antioxidant
Authors: Tebani M. , Boudou L. , Guastavino J.
Published: May 2008

The purpose of this study is an investigation upstream of polymer insulator ageing and rupture. We studied the electrical and physicochemical properties of a low‐density polyethylene (LDPE) used in high‐power insulated cables. Space charge measurements using pulsed electroacoustic method and thermally stimulated depolarization current (TSDC) were carried out on LDPE samples, with and without antioxidant, at different temperatures. TSDC peaks were observed only in the presence of an antioxidant. Furthermore, a TSDC anomalous peak was revealed for the sample containing an antioxidant and polarized at 50°C. All the TSDC peaks are interpreted as trapped charges and can be explained by measuring the space charge distribution within the sample bulk. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and FTIR spectroscopic investigation of the UV curing kinetics of telechelic urethane methacrylate crosslinkers based on the renewable resource—Cardanol
Authors: Rekha N. , Asha S. K.
Published: May 2008

UV curable telechelic urethane–methacrylate crosslinkers based on the natural resource—cardanol was synthesized in a one pot synthetic step involving end capping of isophorone diisocyanate with one equivalent of hydroxyethyl methacrylate followed by condensation with cardanol. The structures of the resins were characterized by 1H and 13C NMR, fourier transform infrared (FTIR) and Matrix‐assisted laser desorption/ionization time of flight (MALDI‐TOF) spectroscopies and size exclusion chromatography (SEC). The curing process and double bond conversion in presence of 2,2‐diethoxy acetophenone as photoinitiator upon UV irradiation was followed by Fourier transform infrared spectroscopy. These hydrogen bonded crosslinkers based on cardanol and its derivatives had higher double bond conversion when compared to a nonhydrogen bonding standard such as hexanediol diacrylate (HDDA) under identical conditions. The temperature effects on the hydrogen bonding were investigated, and a decrease in the extent of double bond conversion with increase in temperature was observed for the telechelic urethane–methacrylate crosslinkers whereas a steady increase in the curing rate was observed for HDDA. This gives direct indication of the influence of hydrogen bonding on the curing process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
On adapting PQPFs to fit hydrological needs: the case of flash flood forecasting
Authors: Marty R. , Zin I. , Obled Ch.
Published: May 2008

A simple, but rather complete hydro‐meteorological system for ensemble flash flood forecasting is described. Special focus is put on the use of precipitation forecasts, essentially quantitative and overall probabilistic (PQPFs). A first issue addressed concerns the matching of the time‐step used by the meteorological forecasts providers (12 or 24 h) with the appropriate hydrological time‐step for quick responding catchments (1 h or less). A second issue concerns the forecasts management between two updating cycles of the PQPFs. Finally, ensemble discharge forecasts for a case‐study event observed in Vogüé (South‐eastern France) are illustrated as an application of our flood forecasting system. Copyright © 2008 Royal Meteorological Society
Guanine quadruplex formation by RNA/DNA hybrid analogs of Oxytricha telomere G4T4G4 fragment
Authors: Vondrušková Jitka , Kypr Jaroslav , Kejnovská Iva , Fialová Markéta , Vorlíčková Michaela
Published: May 2008

Using circular dichroism spectroscopy, gel electrophoresis, and ultraviolet absorption spectroscopy, we have studied quadruplex folding of RNA/DNA analogs of the Oxytricha telomere fragment, G4T4G4, which forms the well‐known basket‐type, antiparallel quadruplex. We have substituted riboguanines (g) for deoxyriboguanines (G) in the positions G1, G9, G4, and G12; these positions form the terminal tetrads of the G4T4G4 quadruplex and adopt syn, syn, anti, and anti glycosidic geometries, respectively. We show that substitution of a single sugar was able to change the quadruplex topology. With the exception of G4T4G3g, which adopted an antiparallel structure, all the RNA/DNA hybrid analogs formed parallel, bimolecular quadruplexes in concentrated solution at low salt. In dilute solutions (∼0.1 mM nucleoside), the RNA/DNA hybrids substituted at positions 4 or 12 adopted antiparallel quadruplexes, which were especially stable in Na+ solutions. The hybrids substituted at positions 1 and 9 preferably formed parallel quadruplexes, which were more stable than the nonmodified G4T4G4 quadruplex in K+ solutions. Substitutions near the 3′end of the molecule affected folding more than substitutions near the 5′end. The ability to control quadruplex folding will allow further studies of biophysical and biological properties of the various folding topologies. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 797–806, 2008.

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