1,320 research outputs found
The effects of Hordeum spontaneum C. Koch. germplasm on barley production
Several studies have shown that Hordeum spontaneum contains potentially useful genes for improving agronomic traits of cultivated barley. In this study, the value of seven accessions of H. spontaneum C. Koch as donors of both cytoplasmic and nuclear genes affecting agronomic traits of barley were investigated;Favorable effects of H. spontaneum cytoplasm were found for straw yield, unit straw weight, and vegetative growth index. These favorable effects were actually attributed to nuclear-cytoplasmic interactions as indicated by the presence of cytoplasm-mating interactions and absence of cytoplasmic-generation interactions. Thus, H. spontaneum cytoplasmic genome must have interacted with H. vulgare nuclear genome. H. vulgare cytoplasmic effects were found to be superior to H. spontaneum for grain yield and harvest index. These cytoplasmic effects were attributed to nuclear-cytoplasmic interactions as indicated by the presence of cytoplasm-generation interactions. Therefore, H. vulgare cytoplasm must have interacted with either (a) H. spontaneum nuclear genes alone, or (b) specific combinations of H. spontaneum and H. vulgare nuclear genes;The seven accessions used in this study were assigned to four ecotypes and tested for variability among and within ecotypes by evaluating ecotype segregates. Superior performance for specific traits was, at least in part, a result of specific ecotypes. The most obvious effect was the superior straw yield performance from coastal ecotype segregates; however, these ecotype segregates also had the poorest harvest index. Segregates from matings involving northern and southern ecotypes had the highest harvest index. Based on the small sample size, variability among and within ecotype segregates suggests the possibility of obtaining superior progenies by sampling a larger number of accessions among and within ecotype categories. Results also further verify the utility of H. spontaneum ecotypes as donors of genes for agronomic traits in barley
Dispersal Dynamics of the Bivalve Gemma Gemma in a Patchy Environment
The purpose of this study was to analyze the dispersal dynamics of the ovoviviparous bivalve Gemma gemma (hereafter referred to as Gemma) in an environment disturbed by the pit-digging activities of horseshoe crabs, Limulus polyphemus. Gemma broods its young and has no planktonic larval stage, so all dispersal is the result of juvenile and adult movement. Animal movement was measured using natural crab pits, hand-dug simulated crab pits, and cylindrical bottom traps in the intertidal zone at Tom\u27s Cove, Virginia, USA.
This study demonstrated that horseshoe crabs create localized patches with reduced densities of Gemma, that all sizes and ages of Gemma quickly disperse into these low density patches, and that the mechanism of dispersal is passive bedload and suspended load transport. Freshly excavated natural pits had significantly lower Gemma densities than did undisturbed background sediment, but there were no significant differences in total density of other species, number of species, and species diversity (H\u27). Equitability (J\u27) was greater in pits than in controls because of the reduced abundance of Gemma, the numerically dominant species. Newly dug simulated crab pits also had significantly lower Gemma densities than controls and returned to control levels by the next day. Density recovery trajectories for individually marked pits showed consistent responses in summer and fall, but not in winter when low Gemma abundance resulted in greater variability among pits.
Significant positive correlations between the volume of sediment and the number of Gemma collected per bottom trap support the hypothesis that Gemma dispersal is a passive transport phenomenon. Assuming no active, density-dependent movement, the product of the Gemma density frequency distribution in undisturbed background sediment and the frequency distribution of sediment volume collected per trap created a predicted Gemma frequency distribution in traps that matched the actual distribution. Absolute dispersal rates and relative dispersal rates (absolute dispersal rate divided by background density in undisturbed sediment) into pits and traps were greater in summer than winter. Dispersal rate results suggest that increased horseshoe crab disturbance in summer may cause an increase in Gemma transport. Because Gemma individuals are dispersed by hydrodynamic action, it was expected that small, young individuals would be most easily transported in the bedload. There was, however, little evidence that movement into pits and traps was size- or age-selective.
Most recent benthic dispersal research has focused on the large-scale movement and settlement patterns of invertebrate larvae. The results from this study illustrate that dispersal of bottom-dwelling juveniles and adults plays an important role in regulating the local distribution and abundance of Gemma. Previous workers have shown that young Gemma live in dense aggregations and that growth and fecundity are reduced at such high densities, leading to population crashes. This study demonstrated a mechanism by which Gemma disperses into low-density patches where intraspecific competition may be mitigated, possibly resulting in enhanced individual reproductive success and population fitness
Analysis of Cell-Mediated Immune Responses in Support of Dengue Vaccine Development Efforts
Dengue vaccine development has made significant strides, but a better understanding of how vaccine-induced immune responses correlate with vaccine efficacy can greatly accelerate development, testing, and deployment as well as ameliorate potential risks and safety concerns. Advances in basic immunology knowledge and techniques have already improved our understanding of cell-mediated immunity of natural dengue virus infection and vaccination. We conclude that the evidence base is adequate to argue for inclusion of assessments of cell-mediated immunity as part of clinical trials of dengue vaccines, although further research to identify useful correlates of protective immunity is needed
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Untangling the Effects of Scheduled Exercise on Child Engagement, Stereotypy, and Challenging Behavior
There is limited research pertaining to the effects of exercise on the behavior of children with autism. Previous researchers focused on exploring the dimensions of the exercise itself, leaving a functional account of the effects of exercise undetermined. There is recent evidence that exercise suppresses responses maintained by automatic reinforcement. The purpose of the present study was to better identify the relevant independent variable in such research and to assess if there were differential effects of exercise across functional response classes. The experimenter conducted a trial-based functional analysis and then implemented a sedentary or vigorous activity on alternating days to determine the impact of exercise on engagement, stereotypy, and challenging behavior. Results across functional response classes were variable as were data across individual sessions. There was a mean suppression of behavior maintained by nonsocial reinforcement during post-sedentary (4.3%) and post-exercise sessions (2.3%). A discussion of the role of matched stimulation and heart rate as a pertinent variable follows
Defining epitope coverage requirements for T cell-based HIV vaccines: Theoretical considerations and practical applications
<p>Abstract</p> <p>Background</p> <p>HIV vaccine development must address the genetic diversity and plasticity of the virus that permits the presentation of diverse genetic forms to the immune system and subsequent escape from immune pressure. Assessment of potential HIV strain coverage by candidate T cell-based vaccines (whether natural sequence or computationally optimized products) is now a critical component in interpreting candidate vaccine suitability.</p> <p>Methods</p> <p>We have utilized an N-mer identity algorithm to represent T cell epitopes and explore potential coverage of the global HIV pandemic using natural sequences derived from candidate HIV vaccines. Breadth (the number of T cell epitopes generated) and depth (the variant coverage within a T cell epitope) analyses have been incorporated into the model to explore vaccine coverage requirements in terms of the number of discrete T cell epitopes generated.</p> <p>Results</p> <p>We show that when multiple epitope generation by a vaccine product is considered a far more nuanced appraisal of the potential HIV strain coverage of the vaccine product emerges. By considering epitope breadth and depth several important observations were made: (1) epitope breadth requirements to reach particular levels of vaccine coverage, even for natural sequence-based vaccine products is not necessarily an intractable problem for the immune system; (2) increasing the valency (number of T cell epitope variants present) of vaccine products dramatically decreases the epitope requirements to reach particular coverage levels for any epidemic; (3) considering multiple-hit models (more than one exact epitope match with an incoming HIV strain) places a significantly higher requirement upon epitope breadth in order to reach a given level of coverage, to the point where low valency natural sequence based products would not practically be able to generate sufficient epitopes.</p> <p>Conclusions</p> <p>When HIV vaccine sequences are compared against datasets of potential incoming viruses important metrics such as the minimum epitope count required to reach a desired level of coverage can be easily calculated. We propose that such analyses can be applied early in the planning stages and during the execution phase of a vaccine trial to explore theoretical and empirical suitability of a vaccine product to a particular epidemic setting.</p
The Impact of Sexual or Physical Abuse History on Pain‐Related Outcomes Among Blacks and Whites with Chronic Pain: Gender Influence
Objectives. Physical and sexual abuses commonly co‐occur with chronic pain. We hypothesized that: 1) abuse history questions would form distinct factors that relate differently to pain perceptions and pain outcomes; 2) abuse history consequences on physical and mental health differ by gender; and 3) different abuse types and age of occurrence (childhood vs adolescent/adulthood) predict different negative outcomes. Methods. Chronic pain patients at a tertiary care pain center provided data (64% women, 50% black) through a confidential survey. Factors were formed for abuse type and age. Linear regression, controlling for socio‐demographic information, was used to examine the relationship between abuse and abuse by sex interactions with pain‐related outcomes. Results. Six 3‐item abuse factors (α = 0.77–0.91)—sexual molestation, sexual penetration, and physical abuse—were identified in both childhood and adulthood. Lifetime prevalence of abuse was 70% for men and 65% for women. Women experienced lower physical abuse ( P = 0.01) in childhood, and higher penetration ( P = 0.02) in adulthood. Decreased general health was associated with all abuse types ( P < 0.05) in childhood. Affective pain was associated with all childhood abuse scales and adulthood molestation, though childhood molestation only for men ( P = 0.04). Disability was associated with childhood ( P = 0.02) and adulthood rape ( P = 0.04). Men with childhood or adulthood molestation ( P = 0.02; P = 0.02) reported higher post‐traumatic stress disorder. Conclusions. Our study confirms physical and mental health, and pain‐related outcomes are affected by abuse history for men and women. These results support screening all patients for abuse to improve the survivor's overall health and well‐being.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90270/1/j.1526-4637.2011.01312.x.pd
Core Health Outcomes In Childhood Epilepsy (CHOICE):Protocol for the selection of a core outcome set
This is the final version of the article. Available from BioMed Central via the DOI in this record.BACKGROUND: There is increasing recognition that establishing a core set of outcomes to be evaluated and reported in trials of interventions for particular conditions will improve the usefulness of health research. There is no established core outcome set for childhood epilepsy. The aim of this work is to select a core outcome set to be used in evaluative research of interventions for children with rolandic epilepsy, as an exemplar of common childhood epilepsy syndromes. METHODS: First we will identify what outcomes should be measured; then we will decide how to measure those outcomes. We will engage relevant UK charities and health professional societies as partners, and convene advisory panels for young people with epilepsy and parents of children with epilepsy. We will identify candidate outcomes from a search for trials of interventions for childhood epilepsy, statutory guidance and consultation with our advisory panels. Families, charities and health, education and neuropsychology professionals will be invited to participate in a Delphi survey following recommended practices in the development of core outcome sets. Participants will be able to recommend additional outcome domains. Over three rounds of Delphi survey participants will rate the importance of candidate outcome domains and state the rationale for their decisions. Over the three rounds we will seek consensus across and between families and health professionals on the more important outcomes. A face-to-face meeting will be convened to ratify the core outcome set. We will then review and recommend ways to measure the shortlisted outcomes using clinical assessment and/or patient-reported outcome measures. DISCUSSION: Our methodology is a proportionate and pragmatic approach to expediently produce a core outcome set for evaluative research of interventions aiming to improve the health of children with epilepsy. A number of decisions have to be made when designing a study to develop a core outcome set including defining the scope, choosing which stakeholders to engage, most effective ways to elicit their views, especially children and a potential role for qualitative research.This study is part of Changing Agendas on Sleep, Treatment and Learning in Childhood Epilepsy (CASTLE), which is funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research RP-PG-0615-20007
Predator telemetry informs temporal and spatial overlap with stocked salmonids in Lake Huron
Double-Crested Cormorants (Phalacrocorax auratus), Walleyes (Sander vitreus), and Lake Trout (Salvelinus namaycush) are migratory predators that undergo extensive movements in Lake Huron. Stocking of juvenile salmonid fish (Oncorhynchus and Salmo sp.) is an important component of fishery management in Lake Huron and assessing the spatial and temporal extent of predator movements is a useful consideration for determining when and where to stock juvenile fish to reduce predation and maximize survival. Previous investigation indicated that some Walleyes migrate to the main basin of Lake Huron in spring from Saginaw Bay. Similarly, telemetry studies of Lake Trout movement in Lake Huron have indicated an onshore movement in the spring. We used detection histories of Walleyes implanted with acoustic transmitters tagged in Saginaw Bay and Lake Trout implanted in northern Lake Huron to estimate the arrival date of migrating adults at eight ports in Lake Huron, where hatchery reared juvenile salmonids are stocked. Satellite telemetry of Cormorants that return to nesting grounds in northern Lake Huron were used to estimate their arrival dates at the same Lake Huron ports. Arrival of Walleye at Lake Huron ports ranged from April 10th to May 7th. Cormorants arrived earlier than Walleye at most Lake Huron ports (April 11th–April 18th). Lake Trout were more variable with a range of onshore movement from March 28th to May 16th. Our results suggested stocking efforts at these ports should generally occur before April 14th to decrease predatory impact from Cormorants, Walleyes, and Lake Trout
Nutrient Status and perceptions of energy and macronutrient intake in a Group of Collegiate Female Lacrosse Athletes
Background
The purpose of this study was to compare nutritional intakes against recommended values as well as between the perceived intake and needs of female lacrosse players. Methods
Twenty female NCAA Division II lacrosse players (20.0 ± 1.7 yrs., 169.7 ± 6.4 cm; 69.9 ± 10.7 kg; 27.5 ± 3.3% fat) completed a four-day monitoring period during in-season. Athletes were outfitted with an activity monitor over four consecutive days and completed four-day food records to assess total daily energy expenditure (TDEE) and dietary intake. Body composition was assessed and used to calculate recommended dietary intakes. Actual intake was self-reported using a commercially available food tracking program (MyFitnessPal©, USA). Daily average values were calculated for total and relative energy, protein, carbohydrate, and fat intake. These values were then compared to published nutritional recommendations established by the International Society of Sports Nutrition. Appropriate pairwise comparisons were made depending on the normality of the distribution. Results
Athletes ate significantly less than recommended values for energy, carbohydrates and protein. (p \u3c 0.001). Significant discrepancies (p \u3c 0.001) were also observed between perceptions of intake versus actual intake. Conclusions
Athletes significantly underestimated perceived intake of dietary fat and carbohydrate when compared to perceived needs. Massive standard deviations and ranges were observed, suggesting that some athletes lack a basic understanding of their daily needs. Results from this data suggest that collegiate athletes lack appropriate understanding of basic nutrition needs and could benefit from basic nutrition education as it pertains to their health and performance
Dengue virus downregulates TNFR1- and TLR3-stimulated NF-kB activation by targeting RIPK1
Dengue virus (DENV) infection is the most prevalent arthropod-borne virus disease and is endemic in more than 100 countries. Several DENV proteins have been shown to target crucial human host proteins to evade innate immune responses and establish a productive infection. Here we report that the DENV NS3 protein targets RIPK1 (Receptor Interacting Protein Kinase I), a central mediator of inflammation and cell death, and decreases intracellular RIPK1 levels during DENV infection. The interaction of NS3 with RIPK1 results in the inhibition of NF-κB activation in response to TNFR or TLR3 stimulation. Also, we observed that the effects of NS3 on RIPK1 were independent of NS3 protease activity. Our data demonstrate a novel mechanism by which DENV suppresses normal cellular functions to evade host innate immune response
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