Analysis of Regional Scale Risk of Whirling Disease in Populations of Colorado and Rio Grande Cutthroat Trout Using a Bayesian Belief Network Model

Introduction and spread of the parasite Myxobolus cerebralis, the causative agent of whirling disease, has contributed to the collapse of wild trout populations throughout the intermountain west. Of concern is the risk the disease may have on conservation and recovery of native cutthroat trout. We employed a Bayesian belief network to assess probability of whirling disease in Colorado River and Rio Grande cutthroat trout (Oncorhynchus clarkii pleuriticus and Oncorhynchus clarkii virginalis, respectively) within their current ranges in the southwest United States. Available habitat (as defined by gradient and elevation) for intermediate oligochaete worm host, Tubifex tubifex, exerted the greatest influence on the likelihood of infection, yet prevalence of stream barriers also affected the risk outcome. Management areas that had the highest likelihood of infected Colorado River cutthroat trout were in the eastern portion of their range, although the probability of infection was highest for populations in the southern, San Juan subbasin. Rio Grande cutthroat trout had a relatively low likelihood of infection, with populations in the southernmost Pecos management area predicted to be at greatest risk. The Bayesian risk assessment model predicted the likelihood of whirling disease infection from its principal transmission vector, fish movement, and suggested that barriers may be effective in reducing risk of exposure to native trout populations. Data gaps, especially with regard to location of spawning, highlighted the importance in developing monitoring plans that support future risk assessments and adaptive management for subspecies of cutthroat trout.     

Homeless Youths’ Interests in Social Action via Photovoice

Engaging homeless youth in services is challenging. Novel methods are needed to better retain and empower this population. Photovoice, an innovative form of community-based participatory research, facilitates participants’ use of photography to document their everyday lives and struggles, while advocating for social change. This study examines, among 22 homeless youth, whether and why youth would be interested in participating in Photovoice activities, the types of social issues youth would be motivated to explore, and homeless youths’ opinions about committing to a longer-term, group-oriented project. Photovoice may represent promise in engaging marginalized and difficult-to-retain populations.     

The impact of welfare reform on marriage and divorce

The goal of the 1996 Personal Responsibility and Work Opportunity Reconciliation Act was to end needy parents' dependence on governmental benefits, in part by promoting marriage. The prereform welfare system was widely believed to discourage marriage because it provided benefits primarily to single mothers. However, welfare reform may have actually decreased the incentives to be married by giving women greater financial independence via the program's new emphasis on work. This article uses vital statistics data on marriages and divorces during 1989-2000 to examine the role of welfare reform (state waivers and implementation of Temporary Assistance to Needy Families) and other state-level variables on flows into and out of marriage. The results indicate that welfare reform has led to fewer new divorces and fewer new marriages, although the latter result is sensitive to specification and the choice of data.     

A review of the challenges of achieving the goals in the African Plan of Action for people with disabilities in Nigeria

The Plan of Action (POA) document was produced at the Pan-African Conference on African Decade of Persons with Disabilities attended by representatives of all African countries in Addis Ababa, Ethiopia (4–7 February 2002). The POA is aimed at implementing priority activities to enhance the services provided to Africans with disabilities during the decade by formulating and implementing meaningful policies and programmes, creating national disability service coordination committees, supporting community-based service delivery, developing poverty alleviation programmes, enhancing preventive programmes, and promoting positive attitudes and awareness of the needs of people with disabilities. While the goals of the POA are noble, evidence raises concerns about the actions so far taken by the Nigerian Government to ensure the implementation of the programme for the benefit of citizens with disabilities. Obstacles to implementing the provisions of the POA document and the implications for strategies that could facilitate the achievement of the goals of the POA are discussed.     

Social networks and sexual risk factor differences between cisgender heterosexual and cisgender LGBQ homeless youths

ABSTRACT

Cisgender lesbian, gay, bisexual, and queer/questioning (LGBQ) homeless youths are more likely to engage in sexual risk behaviors relative to cisgender heterosexual homeless youths. Homeless youths (N = 1,046) were recruited and surveyed from three drop-in centers in Los Angeles, California. This study assessed differences in demographics, background experiences, and perceived social network norms in order to understand the disparities in rates of unprotected sex and concurrent sex between these two subgroups. Results indicate significant differences in engagement in risk factors as well as social network norms. Findings provide support for tailored sexual risk-reduction interventions that cater specifically to LGBQ homeless youths.     

The Need for Mandatory Legislations to Enhance Services to People with Disabilities in Nigeria

The promises concerning the provision of services to individuals with disabilities contained in Nigeria's National Policy on Special Education have not been implemented due to the absence of a legislative mandate to support their implementation. Consequently, the majority of individuals with disabilities in the country are not receiving educational and other relevant services. Based on the evidence of the positive impacts of legislation on special needs provision from several countries, this paper advocates for the enactment of mandatory laws in Nigeria in order to ensure that the right services would be provided to individuals with disabilities in the country. Although the process of enacting legislation on special needs provision could be problematic due to the prevailing political and economic crises in the country, it is argued, however, that effective advocacy activities by patient and professional organisations in the field of special needs could influence the government to take the needs of citizens with disabilities into consideration in policyformulation and legislative mandates.     

R-squared for Bayesian Regression Models

The usual definition of R² (variance of the predicted values divided by the variance of the data) has a problem for Bayesian fits, as the numerator can be larger than the denominator. We propose an alternative definition similar to one that has appeared in the survival analysis literature: the variance of the predicted values divided by the variance of predicted values plus the expected variance of the errors.     

Towards a critical realist epistemology?

When critical realists consider epistemology they typically start from “epistemological relativism.” We find this position necessary, but we also find it insufficient because it lacks a critique of the highly unequal social relations among observers themselves—relations that shape the very production of knowledge. While it is indeed the case that all knowledge is fallible, it is also the case that all knowledge is positioned, with a particular standpoint. What is more, the social power relations between standpoints organize the production of truth in ways that produce systematic distortions. In this paper, we propose a critical realist social epistemology. We introduce feminist standpoint theory and postcolonial theory as our suggested interventions into critical realism and we use two case studies of existing work to highlight i) the social production of truth and the real, and ii) what is at stake for radicalizing epistemology in critical realism. In so doing, our paper emphasizes the epistemic complexities that continuously shape ontology, a commitment to subaltern voices or experiences, and a thorough interrogation of the relations between positions of knowledge production.