Basic notions for the analysis of large two-mode networks

Many large real-world networks actually have a two-mode nature: their nodes may be separated into two classes, the links being between nodes of different classes only. Despite this, and despite the fact that many ad hoc tools have been designed for the study of special cases, very few exist to analyse (describe, extract relevant information) such networks in a systematic way. We propose here an extension of the most basic notions used nowadays to analyse large one-mode networks (the classical case) to the two-mode case. To achieve this, we introduce a set of simple statistics, which we discuss by comparing their values on a representative set of real-world networks and on their random versions. This makes it possible to evaluate their relevance in capturing properties of interest in two-mode networks.     

Suicide Prevention Training Program for Gatekeepers Working in Community Hospice Settings

Gatekeepers in community hospice settings encounter patients and caregivers struggling with suicidal thoughts. Limited guidance is available for training staff on the prevention of suicide in hospice care. This study evaluated one promising, evidence-based, suicide prevention program with a behavioral rehearsal practice session. A pre- and post-, one group design, was utilized to measure the training impact and educational needs of staff working in community hospice settings (N =39). Training increased awareness of the risk factors for suicide, as reported by nearly 80% of participants. Self-efficacy scores showed a statistically significant Increase, t(df = 35), ?9.59, p= .00 (two-tailed), from pretraining (n=36, M=2.21, SD= .65) to posttraining (n=36, M=3.03, SD=.56). Satisfaction and the need for additional devoted time for suicide prevention training were highly rated. Suicide prevention training programs can enhance self-efficacy, knowledge, and skills for gatekeepers working in community hospice settings.     

The impact of liquidity constraints and imperfect commitment on migration decisions of offspring of rural households

This paper presents a non-cooperative model of intra-household decision-making regarding investment in migration. It is shown that the combination of liquidity constraints and imperfect commitment are a source of underinvestment in migration. More precisely, we highlight that, if remittances are unenforceable as a repayment for the parent’s contribution in migration transaction costs, then both the migrant and the parent’s liquidity constraints, rather than the household’s liquidity constraint as a whole, matter in determining the investment decision. Besides, the insurance motive for remittances is shown to generate divergence of interest over the characteristics of migration. This result calls for a theoretical approach that properly takes account of potential internalization problems, which the paper intends to offer. Plausibility checks of the model are provided by comparative statics whose outcomes are consistent with previous research on migration and remittances.     

Probabilistic evaluation of handwriting evidence: likelihood ratio for authorship

Summary.  The evaluation of handwritten characters that are selected from an anonymous letter and written material from a suspect is an open problem in forensic science. The individualization of handwriting is largely dependent on examiners who evaluate the characteristics in a qualitative and subjective way. Precise individual characterization of the shape of handwritten characters is possible through Fourier analysis: each handwritten character can be described through a set of variables such as the surface and harmonics as demonstrated by Marquis and co-workers in 2005. The assessment of the value of the evidence is performed through the derivation of a likelihood ratio for multivariate data. The methodology allows the forensic scientist to take into account the correlation between variables, and the non-constant variability within sources (i.e. individuals). Numerical procedures are implemented to handle the complexity and to compute the marginal likelihood under competing propositions.     

Combining Quantitative and Qualitative Measures of Uncertainty in Model-Based Environmental Assessment: The NUSAP System

This article discusses recent experiences with the Numeral Unit Spread Assessment Pedigree (NUSAP) system for multidimensional uncertainty assessment, based on four case studies that vary in complexity. We show that the NUSAP method is applicable not only to relatively simple calculation schemes but also to complex models in a meaningful way and that NUSAP is useful to assess not only parameter uncertainty but also (model) assumptions. A diagnostic diagram can be used to synthesize results of quantitative analysis of parameter sensitivity and qualitative review (pedigree analysis) of parameter strength. It provides an analytic tool to prioritize uncertainties according to quantitative and qualitative insights in the limitations of available knowledge. We show that extension of the pedigree scheme to include societal dimensions of uncertainty, such as problem framing and value-laden assumptions, further promotes reflexivity and collective learning. When used in a deliberative setting, NUSAP pedigree assessment has the potential to foster a deeper social debate and a negotiated management of complex environmental problems.     

Personal and Professional Knowledge of and Experience With Suicide and Suicide Prevention Among Stakeholders in Clinical and Community Practice

Community-dwelling veterans at risk for suicide may be in contact with a variety of providers in agency-based settings that offer health and human services. The study aim is to describe the perspective of agency-based clinical and community providers who may come into contact with veterans in need of suicide prevention services and to examine the nature of their personal and professional relationships to individuals at risk for suicide among this sample.

This study reports on qualitative data from a sample of Veterans’ Affairs (VA) and community providers serving veterans and military families in one Midwestern state (N = 70). Providers completed a survey assessing exposure to suicide, including contact with and relationship to someone suicidal, and organizational characteristics of the providers’ employing agencies. Semi-structured interview questions probed for the nature of how they would react with suicidal individuals. Most providers (94%) had some prior contact with someone who was suicidal, and nearly three quarters (77%) knew someone who had died by suicide. Providers reported powerful emotional responses of sadness and remorse to suicidal experiences. While these providers interact with veterans and military families as part of their jobs, they may have their own history of being exposed to suicide, both professionally and personally.     

Les usages épistémiques des réseaux de communication électronique : Le cas de l’Open-Source

The concept of “distributed cognition” is applied to analyzing communication networks on Internet in order to better understand the role of electronic communications in acquiring and producing knowledge. This case study has as its basis a mailing list to the users of the free software “Debian.user.french”. The communication networks that emerged out of discussions on “threads” determined how knowledge was distributed among persons on the list. The structure of these threads limits the transmission of knowledge and gives rise to two types of epistemic networks: advice networks and discussion networks. Electronic communication networks facilitate the coexistence of these two types in a single community. Procedures that lead to a discussion of advices serve to select informants with a reputation and to develop cooperative structures out of the relationships formed while giving advice. This coexistence of various epistemic uses characterizes open-source communities, since it combines the cooperative production of a body of knowledge and the transmission of instructions to learners.