A food chain ecoepidemic model: infection at the bottom trophic level

In this paper we consider a three level food web subject to a disease affecting the bottom prey. The resulting dynamics is much richer with respect to the purely demographic model, in that it contains more transcritical bifurcations, gluing together the various equilibria, as well as persistent limit cycles, which are shown to be absent in the classical case. Finally, bistability is discovered among some equilibria, leading to situations in which the computation of their basins of attraction is relevant for the system outcome in terms of its biological implications

Incorporation of aptamers in the terminal loop of shRNAs yields an effective and novel combinatorial targeting strategy.

Gene therapy by engineering patient's own blood cells to confer HIV resistance can potentially lead to a functional cure for AIDS. Toward this goal, we have previously developed an anti-HIV lentivirus vector that deploys a combination of shRNA, ribozyme and RNA decoy. To further improve this therapeutic vector against viral escape, we sought an additional reagent to target HIV integrase. Here, we report the development of a new strategy for selection and expression of aptamer for gene therapy. We developed a SELEX protocol (multi-tag SELEX) for selecting RNA aptamers against proteins with low solubility or stability, such as integrase. More importantly, we expressed these aptamers in vivo by incorporating them in the terminal loop of shRNAs. This novel strategy allowed efficient expression of the shRNA-aptamer fusions that targeted RNAs and proteins simultaneously. Expressed shRNA-aptamer fusions targeting HIV integrase or reverse transcriptase inhibited HIV replication in cell cultures. Viral inhibition was further enhanced by combining an anti-integrase aptamer with an anti-HIV Tat-Rev shRNA. This construct exhibited efficacy comparable to that of integrase inhibitor Raltegravir. Our strategy for the selection and expression of RNA aptamers can potentially extend to other gene therapy applications

Gendered Violence, HIV Acquisition, and Clinical/Behavioral Research

HIV incidence and prevalence rates for US women continue to increase, especially among Black and Latina women. In addition, the link between violence and HIV acquisition has been well documented. However, the interaction between violence, HIV risk, and HIV acquisition remains an under-addressed issue in current clinical and behavioral HIV research designs. Because violence against women plays an important role in HIV acquisition and transmission, it is imperative for clinical research to address violence in trial design and implementation. In this article, we discuss the prevalence of violence in women’s lives; the role violence plays in HIV acquisition; and the absence of violence in clinical research designs. We conclude with recommendations for integrating concerns about HIV and violence against women into sponsor- and investigator-driven HIV research priorities and clinical trial design

College Students\u27 Perceptions of Professor/Instructor Bullying: Questionnaire Development and Psychometric Properties

Objective: This study developed and examined the psychometric properties of a newly formed measure designed to assess professor/instructor bullying, as well as teacher bullying occurring prior to college. Additionally, prevalence of instructor bullying and characteristics related to victims of instructor bullying were examined. Participants: Participants were 337 college students recruited in 2012 from a northeastern university. Methods: An online questionnaire was administered to college students. A split-half, cross-validation approach was employed for measurement development. Results: The measure demonstrated strong criterion validity and internal consistency. Approximately half of students reported witnessing professor/instructor bullying and 18% reported being bullied by a professor/instructor. Report of teacher bullying occurring prior to college was related to professor/instructor bullying in college, and sex was a moderating variable. Conclusion: College students perceive instructor bullying as occurring but may not know how to properly address it. Prevention efforts should be made by university administrators, faculty, and staff

Measuring Positive Psychology Constructs to Determine the Effect of a Well-being Intervention at GateWay Community College

In partnership with GateWay Community College (GWCC), the following service-learning project outlines an application plan to implement validated measures of positive psychology constructs through GWCC’s Strategies for College Success (CPD150) course. Supported by a situation analysis and literature review, constructs of Hope, Grit and Career Decision Self-Efficacy were identified as key constructs to be measured in alignment with the course curriculum and research demonstrating a positive correlation to student achievement and well-being outcomes. The application plan describes the identified measures for each construct, resources to support implementation within CPD150, and recommendations for additional measures and limitations

Neurocognitive enhancement or impairment? A systematic meta-analysis of prescription stimulant effects on processing speed, decision-making, planning, and cognitive perseveration

Increasing numbers of adults, particularly college students, are misusing prescription stimulants primarily for cognitive/academic enhancement, so it is critical to explore whether empirical findings support neurocognitive benefits of prescription stimulants. Previous meta-analytic studies have supported small benefits from prescription stimulants for the cognitive domains of inhibitory control and memory; however, no meta-analytic studies have examined the effects on processing speed or the potential impairment on other domains of cognition, including planning, decision-making, and cognitive perseveration. Therefore, the present study conducted a meta-analysis of the available literature examining the effects of prescription stimulants on specific measures of processing speed, planning, decision-making, and cognitive perseveration among healthy adult populations. The meta-analysis results indicated a positive influence of prescription stimulant medication on processing speed accuracy, with an overall mean effect size of g = 0.282 (95% CI [0.077, 0.488]; n = 345). Neither improvements nor impairments were revealed for planning time, planning accuracy, advantageous decision-making, or cognitive perseveration; however, findings are limited by the small number of studies examining these outcomes. Findings support that prescription stimulant medication may indeed act as a neurocognitive enhancer for accuracy measures of processing speed without impeding other areas of cognition. Considering that adults are already engaging in illegal use of prescription stimulants for academic enhancement, as well as the potential for stimulant misuse to have serious side effects, the establishment of public policies informed by interdisciplinary research surrounding this issue, whether restrictive or liberal, is of critical importance

Niche Recycling through Division-Independent Egress of Hematopoietic Stem Cells

Hematopoietic stem cells (HSCs) are thought to reside in discrete niches through stable adhesion, yet previous studies have suggested that host HSCs can be replaced by transplanted donor HSCs, even in the absence of cytoreductive conditioning. To explain this apparent paradox, we calculated, through cell surface phenotyping and transplantation of unfractionated blood, that ∼1–5% of the total pool of HSCs enters into the circulation each day. Bromodeoxyuridine (BrdU) feeding experiments demonstrated that HSCs in the peripheral blood incorporate BrdU at the same rate as do HSCs in the bone marrow, suggesting that egress from the bone marrow to the blood can occur without cell division and can leave behind vacant HSC niches. Consistent with this, repetitive daily transplantations of small numbers of HSCs administered as new niches became available over the course of 7 d led to significantly higher levels of engraftment than did large, single-bolus transplantations of the same total number of HSCs. These data provide insight as to how HSC replacement can occur despite the residence of endogenous HSCs in niches, and suggest therapeutic interventions that capitalize upon physiological HSC egress

Optimizing the Heavy Metal Ion Sensing Properties of Functionalized Silver Nanoparticles: The Role of Surface Coating Density

We present a colorimetric sensor based on functionalized silver nanoparticles for the detection of metal ions in aqueous solutions. The interaction between the target metal ion and the functionalizing agent triggers the aggregation of these nanoparticles, and the consequent change in optical properties allows the detection/quantification of the analyte. In detail, this work describes the synthesis of AgNPs by a chemical reduction method, and the production of mercaptoundecanoic acid functionalized NPs with different surface densities (multi-, full-, and two partial layers). UV-Vis spectroscopy was used to monitor the functionalization processes, and to investigate the aggregation behavior of each AgNPs@11MUA sensor upon titration with the metal ions of interest, namely Ni2+, Zn2+, Co2+, Cd2+, Mn2+, and Cu2+. The resulting UV-Vis raw data obtained for each layer density were submitted to principal component analysis to dissect the role of the metal ions in NP aggregation and in establishing the sensitivity and selectivity of the AgNPs@11MUA sensor. Interestingly, we observed an increase in sensor sensitivity and selectivity at a lower density of the functionalizing agent on the AgNPs’ surface, which results in characteristic colors of the NP suspension upon titration with each metal ion

Comparative analysis of hybridized solutions to water resources management in Burkina Faso, India and Peru

Hybridization of ‘green’ and engineered infrastructure, informed by protecting or restoring catchment processes, can resolve interconnected demands on catchment ecosystems, potentially also reversing historic degradation of socio-ecological systems. Pressures are acute in water-scarce, developing regions with episodic rainfall, exacerbated by historic presumptions favouring engineered management. Comparing conditions, histories and emerging approaches in contrasting regions – the Central Plateau of Burkina Faso, Rajasthan State (India) and Ayacucho Region (Peru) – reveals similar yet distinct approaches reflecting different starting regimes. Transferrable learning about hybridising localised, nature-based solutions and engineered technology informs the necessary transition towards a sustainable approach these and other regions