70 research outputs found
The Influence of Signaling Conspecific and Heterospecific Neighbors on Eavesdropper Pressure
The study of tradeoffs between the attraction of mates and the attraction of eavesdropping predators and parasites has generally focused on a single species of prey, signaling in isolation. In nature, however, animals often signal from mixed-species aggregations, where interactions with heterospecific group members may be an important mechanism modulating tradeoffs between sexual and natural selection, and thus driving signal evolution. Although studies have shown that conspecific signalers can influence eavesdropper pressure on mating signals, the effects of signaling heterospecifics on eavesdropper pressure, and on the balance between natural and sexual selection, are likely to be different. Here, we review the role of neighboring signalers in mediating changes in eavesdropper pressure, and present a simple model that explores how selection imposed by eavesdropping enemies varies as a function of a signaling aggregation\u27s species composition, the attractiveness of aggregation members to eavesdroppers, and the eavesdroppers\u27 preferences for different member types. This approach can be used to model mixed-species signaling aggregations, as well as same-species aggregations, including those with non-signaling individuals, such as satellites or females. We discuss the implications of our model for the evolution of signal structure, signaling behavior, mixed-species aggregations, and community dynamics
Creating New Knowledge with Undergraduate Students: Institutional Incentives and Faculty Agency
Undergraduate students today face a more demanding and competitive labor market than their parentsβ generation. In response, some pursue double majors to signal breadth to potential employers and to improve their job prospects. Some students also realize that a strong signal of workplace readiness is acquiring in-demand skills through independent and collaborative research. In this article, four professors at an undergraduate-focused public university in the United States share their experiences working with undergraduate students on research, focusing on the βsupply sideβ of student research training and mentoring. We discuss how institutions can support differently situated faculty members, who face different career incentives and constraints, to integrate undergraduates in their research. We also address the limits of what is possible for facultyβstudent research and suggest ways to overcome them
SMS texts on corruption help Ugandan voters hold elected councillors accountable at the polls
Many politicians manipulate information to prevent voters from holding them accountable; however, mobile text messages may make it easier for nongovernmental organizations to credibly share information on official corruption that is difficult for politicians to counter directly. We test the potential for texts on budget management to improve democratic accountability by conducting a large (n = 16,083) randomized controlled trial during the 2016 Ugandan district elections. In cooperation with a local partner, we compiled, simplified, and text-messaged official information on irregularities in local government budgets. Verified recipients of messages that described more irregularities than expected reported voting for incumbent councillors 6% less often; verified recipients of messages conveying fewer irregularities than expected reported voting for incumbent councillors 5% more often. The messages had no observable effect on votes for incumbent council chairs, potentially due to voters\u27 greater reliance on other sources of information for higher profile elections. These mixed results suggest that text messages on budget corruption help voters hold some politicians accountable in settings where elections are not free and fair
Individualized text messages about public services fail to sway voters: evidence from a field experiment on Ugandan elections
Mobile communication technologies can provide citizens access to information that is tailored to their specific circumstances. Such technologies may therefore increase citizens' ability to vote in line with their interests and hold politicians accountable. In a large-scale randomized controlled trial in Uganda (n = 16,083), we investigated whether citizens who receive private, timely, and individualized text messages by mobile phone about public services in their community punished or rewarded incumbents in local elections in line with the information. Respondents claimed to find the messages valuable and there is evidence that they briefly updated their beliefs based on the messages; however, the treatment did not cause increased votes for incumbents where public services were better than expected nor decreased votes where public services were worse than anticipated. The considerable knowledge gaps among citizens identified in this study indicate potential for communication technologies to effectively share civic information. Yet the findings imply that when the attribution of public service outcomes is difficult, even individualized information is unlikely to affect voting behavior
Information about service provision in Uganda is insufficient to affect voting behaviour
The quality of service provision in Uganda varies greatly across regions and between villages, and yet evidence suggests citizensβ are unable to assess these differences. A research experiment used SMS messages about public services to help Ugandans make informed voting decisions, but it found no effect on voting outcomes. Here is why information alone is sometimes insufficient to affect political behaviour
The influence of signaling conspecific and heterospecific neighbors on eavesdropper pressure
Sherpa Romeo green journal. Open access article. Creative Commons Attribution License (CC BY) applies.The study of tradeoffs between the attraction of mates and the attraction of eavesdropping predators and parasites has generally focused on a single species of prey, signaling in isolation. In nature, however, animals often signal from mixed-species aggregations, where interactions with heterospeciο¬c group members may be an important mechanism modulating tradeoffs between sexual and natural selection, and thus driving signal evolution. Although studies have shown that conspeciο¬c signalers can inο¬uence eavesdropper pressure on mating signals, the effects of signaling heterospeciο¬cs on eavesdropper pressure, and on the balance between natural and sexual selection, are likely to be different. Here, we review the role of neighboring signalers in mediating changes in eavesdropper pressure, and present a simple model that explores how selection imposed by eavesdropping enemies varies as a function of a signaling aggregationβs species composition, the attractiveness of aggregation members to eavesdroppers, and the eavesdroppersβ preferences for different member types. This approach can be used to model mixed-species signaling aggregations, as well as same-species aggregations, including those with non-signaling individuals, such as satellites or females. We discuss the implications of our model for the evolution of signal structure, signaling behavior, mixed-species aggregations, and community dynamics.Ye
Informing efficient randomised controlled trials: Exploration of challenges in developing progression criteria for internal pilot studies
Objectives: Designing studies with an internal pilot phase may optimise the use of pilot work to inform more efficient randomised controlled trials (RCTs). Careful selection of preagreed decision or 'progression' criteria at the juncture between the internal pilot and main trial phases provides a valuable opportunity to evaluate the likely success of the main trial and optimise its design or, if necessary, to make the decision not to proceed with the main trial. Guidance on the appropriate selection and application of progression criteria is, however, lacking. This paper outlines the key issues to consider in the optimal development and review of operational progression criteria for RCTs with an internal pilot phase. Design: A structured literature review and exploration of stakeholders' opinions at a Medical Research Council (MRC) Hubs for Trials Methodology Research workshop. Key stakeholders included triallists, methodologists, statisticians and funders. Results: There is considerable variation in the use of progression criteria for RCTs with an internal pilot phase, although 3 common issues predominate: trial recruitment, protocol adherence and outcome data. Detailed and systematic reporting around the decisionmaking process for stopping, amending or proceeding to a main trial is uncommon, which may hamper understanding in the research community about the appropriate and optimal use of RCTs with an internal pilot phase. 10 top tips for the development, use and reporting of progression criteria for internal pilot studies are presented. Conclusions: Systematic and transparent reporting of the design, results and evaluation of internal pilot trials in the literature should be encouraged in order to facilitate understanding in the research community and to inform future trials
Genetics and complement in atypical HUS
Central to the pathogenesis of atypical hemolytic uremic syndrome (aHUS) is over-activation of the alternative pathway of complement. Following the initial discovery of mutations in the complement regulatory protein, factor H, mutations have been described in factor I, membrane cofactor protein and thrombomodulin, which also result in decreased complement regulation. Autoantibodies to factor H have also been reported to impair complement regulation in aHUS. More recently, gain of function mutations in the complement components C3 and Factor B have been seen. This review focuses on the genetic causes of aHUS, their functional consequences, and clinical effect
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