1,377 research outputs found
Estimating climate change effects on net primary production of rangelands in the United States
The potential effects of climate change on net primary productivity (NPP) of U.S. rangelands were evaluated using estimated climate regimes from the A1B, A2 and B2 global change scenarios imposed on the biogeochemical cycling model, Biome-BGC from 2001 to 2100. Temperature, precipitation, vapor pressure deficit, day length, solar radiation, CO2 enrichment and nitrogen deposition were evaluated as drivers of NPP. Across all three scenarios, rangeland NPP increased by 0.26 % year−1 (7 kg C ha−1 year−1) but increases were not apparent until after 2030 and significant regional variation in NPP was revealed. The Desert Southwest and Southwest assessment regions exhibited declines in NPP of about 7 % by 2100, while the Northern and Southern Great Plains, Interior West and Eastern Prairies all experienced increases over 25 %. Grasslands dominated by warm season (C4 photosynthetic pathway) species showed the greatest response to temperature while cool season (C3 photosynthetic pathway) dominated regions responded most strongly to CO2 enrichment. Modeled NPP responses compared favorably with experimental results from CO2 manipulation experiments and to NPP estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS). Collectively, these results indicate significant and asymmetric changes in NPP for U.S. rangelands may be expected
Transforming Growth Factor-β Stimulates the Expression of Fibronectin by Human Keratinocytes
abstractTransforming growth factor beta (TGF-β)is a 25-kD protein which has regulatory activity over a variety of cell types. It is distinct form epidermal growth factor (EGF) and EGF analogs, and exerts its action via a distinct receptor. Its effect on proliferation or differentiation can be positive or negative depending on the cell type and the presence of other growth factors. it also modulates the expression of cellular products. TGF-β causes fibroblasts to increase their production of the extracellular matrix components, fibronectin and collagen. human keratinocytes (HK) are known to have TGF-βreceptors. We wished to study the effect of TGF-β on the production of extracellular matrix proteins by human keratinocytes in culture.Human keratinocytes were grown in serum-free defined medium (MCDB-153) to about 70% confluence. Following a 16-h incubation in medium lacking EGF and TGF-β, cells were incubated for 12h in medium containing varying concentrations of EGF and TGF-β. Cells were then labeled with 35S-methionine for 10 h in the same conditions. Labeled proteins from the medium were analyzed by SDS-PAGE and autoradiography.TGF-β at 10 ng/ml induced a sixfold increase in the secretion of fibronectin, as well as an unidentified 50-kD protein. Thrombospondin production was also increased, but not over a generalized twofold increase in the production of all other proteins. EGF, at 10 ng/ml, caused a smaller additive effect, TGF-β may be an important stimulator of extracellular matrix production by human keratinocytes
Differentiation of primate primordial germ cell-like cells following transplantation into the adult gonadal niche.
A major challenge in stem cell differentiation is the availability of bioassays to prove cell types generated in vitro are equivalent to cells in vivo. In the mouse, differentiation of primordial germ cell-like cells (PGCLCs) from pluripotent cells was validated by transplantation, leading to the generation of spermatogenesis and to the birth of offspring. Here we report the use of xenotransplantation (monkey to mouse) and homologous transplantation (monkey to monkey) to validate our in vitro protocol for differentiating male rhesus (r) macaque PGCLCs (rPGCLCs) from induced pluripotent stem cells (riPSCs). Specifically, transplantation of aggregates containing rPGCLCs into mouse and nonhuman primate testicles overcomes a major bottleneck in rPGCLC differentiation. These findings suggest that immature rPGCLCs once transplanted into an adult gonadal niche commit to differentiate towards late rPGCs that initiate epigenetic reprogramming but do not complete the conversion into ENO2-positive spermatogonia
Maintaining exercise and healthful eating in older adults: The SENIOR project II: Study design and methodology
The Study of Exercise and Nutrition in Older Rhode Islanders (SENIOR) Project II is an intervention study to promote the maintenance of both exercise and healthful eating in older adults. It is the second phase of an earlier study, SENIOR Project I, that originally recruited 1277 community-dwelling older adults to participate in behavior-specific interventions designed to increase exercise and/or fruit and vegetable consumption. The general theoretical framework for this research is the Transtheoretical Model (TTM) of Health Behavior Change. The current intervention occurs over a 48-month period, using a manual, newsletters, and phone coaching calls. Annual assessments collect standardized data on behavioral outcomes (exercise and diet), TTM variables (stage of change and self-efficacy), psychosocial variables (social support, depression, resilience, and life satisfaction), physical activity and functioning (SF-36, Up and Go, Senior Fitness Test, and disability assessment), cognitive functioning (Trail Making Test and Forward and Backward Digit Span), physical measures (height, weight, and waist circumference), and demographics. The SENIOR Project II is designed to answer the following question as its primary objective: (1) Does an individualized active-maintenance intervention with older adults maintain greater levels of healthful exercise and dietary behaviors for 4 years, compared to a control condition? In addition, there are two secondary objectives: (2) What are the psychosocial factors associated with the maintenance of health-promoting behaviors in the very old? (3) What are the effects of the maintenance of health-promoting behaviors on reported health outcomes, psychosocial measures, anthropometrics, and cognitive status
Opportunities for Competency Support of Virginia Cooperative Extension Professionals at the Colleague Stage
This study focused on the professional development needs of Cooperative Extension agents and specialists with between four and seven years of experience, placing them roughly within the colleague career stage. Data were collected through focus groups and validated through member checking and the use of a modified World Café approach. A research team collaborated, increasing the reliability of the findings through intentional reflection in the development of the findings. Areas of competency strength and weakness vary for agents and specialists, and specific topic areas within competencies vary. While many of the emergent competencies identified in this study fit within the competency framework of Harder et al. (2011) and previous competency studies, more specific topic areas were identified. However, the top priorities identified for professional development focus included communication, educational design, leadership, and budget and fiscal management. Attention to these areas can increase the ability of these professionals to work more effectively and productively. Providing professional development in areas of need for both agents and specialists can support the development of collegiality within the Extension organization. Supporting professionals in this stage of their career growth will position them well for advancing to additional career stages within Cooperative Extension
Secondary and 2-Year Outcomes of a Sexual Assault Resistance Program for University Women
We report the secondary outcomes and longevity of efficacy from a randomized controlled trial that evaluated a novel sexual assault resistance program designed for first-year women university students. Participants (N = 893) were randomly assigned to receive the Enhanced Assess, Acknowledge, Act (EAAA) program or a selection of brochures (control). Perception of personal risk, self-defense self-efficacy, and rape myth acceptance was assessed at baseline; 1-week postintervention; and 6-, 12-, 18-, and 24-month postrandomization. Risk detection was assessed at 1 week, 6 months, and 12 months. Sexual assault experience and knowledge of effective resistance strategies were assessed at all follow-ups. The EAAA program produced significant increases in women’s perception of personal risk, self-defense self-efficacy, and knowledge of effective (forceful verbal and physical) resistance strategies; the program also produced decreases in general rape myth acceptance and woman blaming over the entire 24-month follow-up period. Risk detection was significantly improved for the intervention group at post-test. The program significantly reduced the risk of completed and attempted rape, attempted coercion, and nonconsensual sexual contact over the entire follow-up period, yielding reductions between 30% and 64% at 2 years. The EAAA program produces long-lasting changes in secondary outcomes and in the incidence of sexual assault experienced by women students. Universities can reduce the harm and the negative health consequences that young women experience as a result of campus sexual assault by implementing this program. Online slides for instructors who want to use this article for teaching are available on PWQ’s website at http://journals.sagepub.com/page/pwq/suppl/index
Efficacy of a Sexual Assault Resistance Program for University Women
Background
Young women attending university are at substantial risk for being sexually assaulted, primarily by male acquaintances, but effective strategies to reduce this risk remain elusive. Methods
We randomly assigned first-year female students at three universities in Canada to the Enhanced Assess, Acknowledge, Act Sexual Assault Resistance program (resistance group) or to a session providing access to brochures on sexual assault, as was common university practice (control group). The resistance program consists of four 3-hour units in which information is provided and skills are taught and practiced, with the goal of being able to assess risk from acquaintances, overcome emotional barriers in acknowledging danger, and engage in effective verbal and physical self-defense. The primary outcome was completed rape, as measured by the Sexual Experiences Survey–Short Form Victimization, during 1 year of follow-up. Results
A total of 451 women were assigned to the resistance group and 442 women to the control group. Of the women assigned to the resistance group, 91% attended at least three of the four units. The 1-year risk of completed rape was significantly lower in the resistance group than in the control group (5.2% vs. 9.8%; relative risk reduction, 46.3% [95% confidence interval, 6.8 to 69.1]; P=0.02). The 1-year risk of attempted rape was also significantly lower in the resistance group (3.4% vs. 9.3%, P\u3c0.001). Conclusions
A rigorously designed and executed sexual assault resistance program was successful in decreasing the occurrence of rape, attempted rape, and other forms of victimization among first-year university women. (Funded by the Canadian Institutes of Health Research and the University of Windsor; SARE ClinicalTrials.gov number, NCT01338428.
Testing a Model of How a Sexual Assault Resistance Education Program for Women Reduces Sexual Assaults
© The Author(s) 2020. The Enhanced Assess, Acknowledge, Act (EAAA) program has been shown to reduce sexual assaults experienced by university students who identify as women. Prevention researchers emphasize testing theory-based mechanisms once positive outcomes related to effectiveness are established. We assessed the process by which EAAA’s positive outcomes are achieved in a sample of 857 first year university students. EAAA’s goals are to increase risk detection in social interactions, decrease obstacles to risk detection or resistance with known men, and increase women’s use of effective self-defense. We used chained multiple mediator modeling to assess the combined effects of the primary mediators (risk detection, direct resistance, and self-defense self-efficacy) while simultaneously assessing the interrelationships among the secondary mediators (perception of personal risk, belief in the myth of female precipitation, and general rape myth acceptance). The hypothesized multiple mediation model with three primary mediators met the criterion for full mediation of the intervention effects. Together, the mediators accounted for 95% and 76% of the reductions in completed and attempted rape, respectively, demonstrating full mediation. The hypothesized secondary mediators were important in achieving improvements in personal and situational risk detection. The findings strongly support the benefit of cognitive ecological theory and the Assess, Acknowledge, Act conceptualization underlying EAAA. This evidence can be used by administrators and staff responsible for prevention policy and practice on campuses to defend the implementation of theoretically grounded, evidence-based prevention programs
Sexual violence in the lives of first-year university women in Canada: no improvements in the 21st century
Background: Summarizes the frequency, type, and context of sexual assault in a large sample of first-year university women at three Canadian universities. Methods: As part of a randomized controlled trial assessing the efficacy of a sexual assault resistance education program, baseline data were collected from women between ages of 17 and 24 using computerized surveys. Participants’ experience with sexual victimization since the age of 14 years was assessed using the Sexual Experiences Survey–Short Form Victimization (SES-SFV). Results: Among 899 first-year university women (mean age = 18.5 years), 58.7% (95% CI: 55.4%, 62.0%) had experienced one or more forms of victimization since the age of 14 years, 35.0% (95% CI: 31.9%, 38.3%) had experienced at least one completed or attempted rape, and 23.5% (95% CI: 20.7%, 26.4%) had been raped. Among the 211 rape victims, 46.4% (95% CI: 39.7%, 53.2%) had experienced more than one type of assault (oral, vaginal, anal) in a single incident or across multiple incidents. More than three-quarters (79.6%; 95% CI: 74.2%, 85.1%) of the rapes occurred while women were incapacitated by alcohol or drugs. One-third (33.3%) of women had previous self-defence training, but few (4.0%) had previous sexual assault education. Conclusions: Findings from the first large Canadian study of university women since the 1990s indicate that a large proportion of women arrive on campuses with histories of sexual victimization, and they are generally unprepared for the perpetrators they may face during their academic years. There is an urgent need for effective rape prevention programs on university campuses
Measurements of Airborne Influenza Virus in Aerosol Particles from Human Coughs
Influenza is thought to be communicated from person to person by multiple pathways. However, the relative importance of different routes of influenza transmission is unclear. To better understand the potential for the airborne spread of influenza, we measured the amount and size of aerosol particles containing influenza virus that were produced by coughing. Subjects were recruited from patients presenting at a student health clinic with influenza-like symptoms. Nasopharyngeal swabs were collected from the volunteers and they were asked to cough three times into a spirometer. After each cough, the cough-generated aerosol was collected using a NIOSH two-stage bioaerosol cyclone sampler or an SKC BioSampler. The amount of influenza viral RNA contained in the samplers was analyzed using quantitative real-time reverse-transcription PCR (qPCR) targeting the matrix gene M1. For half of the subjects, viral plaque assays were performed on the nasopharyngeal swabs and cough aerosol samples to determine if viable virus was present. Fifty-eight subjects were tested, of whom 47 were positive for influenza virus by qPCR. Influenza viral RNA was detected in coughs from 38 of these subjects (81%). Thirty-five percent of the influenza RNA was contained in particles \u3e4 µm in aerodynamic diameter, while 23% was in particles 1 to 4 µm and 42% in particles \u3c1 µm. Viable influenza virus was detected in the cough aerosols from 2 of 21 subjects with influenza. These results show that coughing by influenza patients emits aerosol particles containing influenza virus and that much of the viral RNA is contained within particles in the respirable size range. The results support the idea that the airborne route may be a pathway for influenza transmission, especially in the immediate vicinity of an influenza patient. Further research is needed on the viability of airborne influenza viruses and the risk of transmission
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