Glucosinolate breakdown products as insect fumigants and their effect on carbon dioxide emission of insects

BACKGROUND: Glucosinolate breakdown products are volatile, therefore good candidates for insect fumigants. However, although they are insecticidal, the mode of action of such natural products is not clear. We studied the insecticidal effect of these compounds as fumigants, and monitored the production of carbon dioxide by the insects as a probe to the understanding of their mode of action. RESULTS: The fumigation 24-h LC(50) against the house fly (Musca domestica L.) of allyl thiocyanate, allyl isothiocyanate, allyl cyanide, and l-cyano-2-hydroxy-3-butene was 0.1, 0.13, 3.66, and 6.2 μg cm(-3), respectively; they were 0.55, 1.57, 2.8, and > 19.60 μg cm(-3), respectively, against the lesser grain borer (Rhyzopertha dominica Fabricius). The fumigation toxicity of some of the glucosinolate products was very close to or better than that of the commercial insect fumigants such as chloropicrin (LC(50): 0.08 and 1.3 μg cm(-3) against M. domestica and R. dominica, respectively) and dichlorovos (LC(50): < 0.02 and 0.29 μg cm(-3) against M. domestica and R. dominica, respectively) in our laboratory tests. Significantly increased CO(2) expiration was found in insects exposed to the vapor of allyl isothiocyanate, allyl thiocyanate and allyl isocyanate. Allyl isothiocyanate was also found to increase the CO(2) expiration of the American cockroach (Periplaneta americana L.). CONCLUSIONS: Glucosinolate breakdown products have potential as biodegradable and safe insect fumigants. They may act on the insect respiratory system in their mode of action

The Inconsistent Work of Web Filters: Mapping Information Access in Alabama Public Schools and Libraries

Recent popular and academic discussions regarding the Internet have raised the question of whether and how networked intermediaries have a (dis)integrating social effects. In this study, we use public records of configurations of Internet filters in Alabama public schools and libraries to show how different institutions implement nominally consistent content standards inconsistently. We argue that these varying implementations are both significant and troubling for two reasons: first, they overreach the stated goals of the legislation with whic h they in principle comply; second, they may contribute to a broader epis temic breakdown by fragmenting the kind of information made available through and across public institutions. Keywords: Internet filtering, filter bubble, censorship, critical infrastructure studies, algorithms, categories, CIPA, libraries, schools, Leigh Sta

Effects of Interventions Addressing School Environments or Educational Assets on Adolescent Sexual Health: Systematic Review and Meta-analysis.

CONTEXT: School-based interventions that aim to modify sexual health knowledge, attitudes and behaviors have mixed and often unsustained effects on adolescent sexual health outcomes. However, observational evidence suggests that broader school-related factors, such as school climate and academic attainment, can influence outcomes. METHODS: Nine databases were searched in July 2017 for randomized and quasi-experimental evaluations of interventions addressing school-level environment or student-level educational assets, to examine whether such interventions can promote young people's sexual health. Searches were limited to studies published since 1990 but were not restricted by language. Studies were assessed for risk of bias and synthesized narratively and meta-analytically. RESULTS: Searches yielded 11 evaluations, published from 1999 to 2016, of interventions related to school-level environment or student-level educational assets. Because of inconsistent reporting, the risk of bias was not clear for most studies, and meta-analysis was possible for only one outcome. The meta-analysis of three randomized trials provided some evidence that school-environment interventions may delay sexual debut (pooled odds ratio, 0.5). Narrative synthesis of the remaining outcomes found mixed results, but suggests that interventions addressing school-level environment may delay sexual debut and that those addressing student-level educational assets may reduce risk of pregnancy and STDs. CONCLUSIONS: Additional and more rigorous evidence is needed to assess the probability that interventions addressing school-related factors are effective and to provide better understanding of the mechanisms by which they may work to improve adolescent sexual health

Dynamic detection of electron spin accumulation in ferromagnet-semiconductor devices by ferromagnetic resonance

A distinguishing feature of spin accumulation in ferromagnet-semiconductor devices is precession of the non-equilibrium spin population of the semiconductor in a magnetic field. This is the basis for detection techniques such as the Hanle effect, but these approaches become less effective as the spin lifetime in the semiconductor decreases. For this reason, no electrical Hanle measurement has been demonstrated in GaAs at room temperature. We show here that by forcing the magnetization in the ferromagnet (the spin injector and detector) to precess at the ferromagnetic resonance frequency, an electrically generated spin accumulation can be detected from 30 to 300 K. At low temperatures, the distinct Larmor precession of the spin accumulation in the semiconductor can be detected by ferromagnetic resonance in an oblique field. We verify the effectiveness of this new spin detection technique by comparing the injection bias and temperature dependence of the measured spin signal to the results obtained using traditional methods. We further show that this new approach enables a measurement of short spin lifetimes (< 100 psec), a regime that is not accessible in semiconductors using traditional Hanle techniques.Comment: 4 figure

School experiences and young women's pregnancy and parenthood decisions: A systematic review and synthesis of qualitative research.

Schools are considered high-potential environments for promoting adolescent sexual and reproductive health outcomes among young women. Qualitative studies provide context and meaning to how school experiences and systems contribute to pregnancy and parenthood decisions from the perspectives of youth. This systematic review screened 24,711 references from 8 databases, yielding 28 qualitative studies. Included studies were assessed for quality and synthesised using meta-ethnographic approaches. Reciprocal translation revealed that young women's education and life trajectories were at least partially shaped by a commitment to school values and expectations for academic achievement, influenced by structural and relational factors within the school. These findings resonate with Markham and Aveyard's theory of human functioning and school organisation. Future policy and practices might seek to improve teacher-student interactions, leverage young women's developing autonomy, and ensure physically and psychologically safe spaces for students

Sawflies (Hymenoptera, Symphyta) Newly Recorded from Washington State

Examination of museum specimens, unpublished collection data, and field surveys conducted between 2010 and 2014 resulted in records for 22 species of sawflies new to Washington State, seven of which are likely to be pest problems in ornamental landscapes. These data highlight the continued range expansion of exotic species across North America. These new records also indicate that our collective knowledge of Pacific Northwest arthropod biodiversity and biogeography is underdeveloped, even for a relatively well known and species-poor group of insects. Notable gaps in the knowledge of Washington State’s Symphyta remain for the Olympic Peninsula, the Cascade Mountain Range, and the arid interior of the state. Washington’s shrub-steppe appears to be particularly poorly surveyed for sawflies

Sawflies (Hymenoptera, Symphyta) Newly Recorded from Washington State

Examination of museum specimens, unpublished collection data, and field surveys conducted between 2010 and 2014 resulted in records for 22 species of sawflies new to Washington State, seven of which are likely to be pest problems in ornamental landscapes. These data highlight the continued range expansion of exotic species across North America. These new records also indicate that our collective knowledge of Pacific Northwest arthropod biodiversity and biogeography is underdeveloped, even for a relatively well known and species-poor group of insects. Notable gaps in the knowledge of Washington State’s Symphyta remain for the Olympic Peninsula, the Cascade Mountain Range, and the arid interior of the state. Washington’s shrub-steppe appears to be particularly poorly surveyed for sawflies