Cave spiders choose optimal environmental factors with respect to the generated entropy when laying their cocoon

The choice of a suitable area to spiders where to lay eggs is promoted in terms of Darwinian fitness. Despite its importance, the underlying factors behind this key decision are generally poorly understood. Here, we designed a multidisciplinary study based both on in-field data and laboratory experiments focusing on the European cave spider Meta menardi (Araneae, Tetragnathidae) and aiming at understanding the selective forces driving the female in the choice of the depositional area. Our in-field data analysis demonstrated a major role of air velocity and distance from the cave entrance within a particular cave in driving the female choice. This has been interpreted using a model based on the Entropy Generation Minimization - EGM - method, without invoking best fit parameters and thanks to independent lab experiments, thus demonstrating that the female chooses the depositional area according to minimal level of thermo-fluid-dynamic irreversibility. This methodology may pave the way to a novel approach in understanding evolutionary strategies for other living organisms

What do young adolescents think about taking part in longitudinal self-harm research?: findings from a school-based study

Background: Research about self-harm in adolescence is important given the high incidence in youth, and strong links to suicide and other poor outcomes. Clarifying the impact of involvement in school based self-harm studies on young adolescents is an ethical priority given heightened risk at this developmental stage. Methods: Here, 594 school-based students aged mainly 13-14 years completed a survey on self-harm at baseline and again 12-weeks later. Change in mood following completion of each survey, ratings and thoughts about participation, and responses to a mood-mitigation activity were analysed using a multi-method approach. Results: Baseline participation had no overall impact on mood. However, boys and girls reacted differently to the survey depending on self-harm status. Having a history of self-harm had a negative impact on mood for girls, but a positive impact on mood for boys. In addition, participants rated the survey in mainly positive/neutral terms, and cited benefits including personal insight and altruism. At follow-up, there was a negative impact on mood following participation, but no significant effect of gender or self-harm status. Ratings at follow-up were mainly positive/neutral. Those who had self-harmed reported more positive and fewer negative ratings than at baseline: the opposite pattern of response was found for those who had not self-harmed. Mood mitigation activities were endorsed. Conclusions: Self-harm research with youth is feasible in school settings. Most young people are happy to take part and cite important benefits. However, the impact of participation in research appears to vary according to gender, self-harm risk and method/time of assessment. The impact of repeated assessment requires clarification. Simple mood-elevation techniques may usefully help to mitigate distress

The Metagenome of an Anaerobic Microbial Community Decomposing Poplar Wood Chips

This study describes the composition and metabolic potential of a lignocellulosic biomass degrading community that decays poplar wood chips under anaerobic conditions. We examined the community that developed on poplar biomass in a non-aerated bioreactor over the course of a year, with no microbial inoculation other than the naturally occurring organisms on the woody material. The composition of this community contrasts in important ways with biomass-degrading communities associated with higher organisms, which have evolved over millions of years into a symbiotic relationship. Both mammalian and insect hosts provide partial size reduction, chemical treatments (low or high pH environments), and complex enzymatic ‘secretomes’ that improve microbial access to cell wall polymers. We hypothesized that in order to efficiently degrade coarse untreated biomass, a spontaneously assembled free-living community must both employ alternative strategies, such as enzymatic lignin depolymerization, for accessing hemicellulose and cellulose and have a much broader metabolic potential than host-associated communities. This would suggest that such a community would make a valuable resource for finding new catalytic functions involved in biomass decomposition and gaining new insight into the poorly understood process of anaerobic lignin depolymerization. Therefore, in addition to determining the major players in this community, our work specifically aimed at identifying functions potentially involved in the depolymerization of cellulose, hemicelluloses, and lignin, and to assign specific roles to the prevalent community members in the collaborative process of biomass decomposition. A bacterium similar to Magnetospirillum was identified among the dominant community members, which could play a key role in the anaerobic breakdown of aromatic compounds. We suggest that these compounds are released from the lignin fraction in poplar hardwood during the decay process, which would point to lignin-modification or depolymerization under anaerobic conditions

Traditional living and cultural ways as protective factors against suicide: perceptions of Alaska Native university students

Introduction. Native peoples living in Alaska have one of the highest rates of suicide in the world. This represents a significant health disparity for indigenous populations living in Alaska. This research was part of a larger study that explored qualitatively the perceptions of Alaska Native university students from rural communities regarding suicide. This analysis explored the resilience that arose from participants’ experiences of traditional ways, including subsistence activities. Previous research has indicated the importance of traditional ways in preventing suicide and strengthening communities. Method. Semi-structured interviews were conducted with 25 university students who had migrated to Fairbanks, Alaska, from rural Alaskan communities. An interview protocol was developed in collaboration with cultural and community advisors. Interviews were audio-recorded and transcribed. Participants were asked specific questions concerning the strengthening of traditional practices towards the prevention of suicide. Transcripts were analysed using the techniques of grounded theory. Findings. Participants identified several resilience factors against suicide, including traditional practices and subsistence activities, meaningful community involvement and an active lifestyle. Traditional practices and subsistence activities were perceived to create the context for important relationships, promote healthy living to prevent suicide, contrast with current challenges and transmit important cultural values. Participants considered the strengthening of these traditional ways as important in suicide prevention efforts. However, subsistence and traditional practices were viewed as a diminishing aspect of daily living in rural Alaska. Conclusions. Many college students from rural Alaska have been affected by suicide but are strong enough to cope with such tragic events. Subsistence living and traditional practices were perceived as important social and cultural processes with meaningful lifelong benefits for participants. Future research should continue to explore the ways in which traditional practices can contribute towards suicide prevention, as well as the far-reaching benefits of subsistence living

Life experiences preceding high lethality suicide attempts in adolescents at a level I regional trauma center

ObjectiveTo describe life experiences associated with patterns of medically treated and documented self- directed violence among youth who attempted suicide using highly lethal means to understand precipitating factors among youth using such lethal means.MethodUsing data from a regional, level 1 Trauma center, we identified all youth suicide attempt survivors who received treatment from 2010 to 2018 for a suicide attempt with a firearm, hanging, or jump from height injury (n = 42). We described differences in patient demographics and life experiences associated with patterns of self- directed violence by suicide attempt mechanism. We additionally assessed mechanisms used in any prior suicide attempts to identify potential increasing lethality of mechanism selection.ResultsThere were 42 eligible patients included, of whom 40.5% attempted suicide with a firearm, 26.2% with hanging, 33.3% with jumping injury. A greater proportion of patients with firearm injuries endorsed social support and had fewer preparatory acts, history of self- harming behavior, prior suicide behaviors, and fewer prior attempts compared to patients who attempted suicide with other mechanisms.ConclusionsGiven our findings, means safety should remain a key strategy to prevent highly lethal suicidal behavior among adolescents, especially with firearms, given that such attempts may occur prior to formal contact with mental health services.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/170807/1/sltb12740_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/170807/2/sltb12740.pd