559 research outputs found

    How to recreate a Viking funeral – minus the human sacrifice

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    First paragraph: When most people think of Vikings, they think of the usual stuff: longships, raiding, fighting, loot, burial and paganism. Scholars are increasingly aware that the reality was more complicated, but no doubt the popular associations will remain – and are reinforced by the likes of last year’s Viking exhibition at the British Museum in London. Access this article at The Conversation webpage: https://theconversation.com/how-to-recreate-a-viking-funeral-minus-the-human-sacrifice-3909

    Research groups: How big should they be?

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    Understanding the relationship between scientific productivity and research group size is important for deciding how science should be funded. We have investigated the relationship between these variables in the life sciences in the United Kingdom using data from 398 principle investigators (PIs). We show that three measures of productivity, the number of publications, the impact factor of the journals in which papers are published and the number of citations, are all positively correlated to group size, although they all show a pattern of diminishing returns—doubling group size leads to less than a doubling in productivity. The relationships for the impact factor and the number of citations are extremely weak. Our analyses suggest that an increase in productivity will be achieved by funding more PIs with small research groups, unless the cost of employing post-docs and PhD students is less than 20% the cost of a PI. We also provide evidence that post-docs are more productive than PhD students both in terms of the number of papers they produce and where those papers are published

    Modelado espacial para peligro de incendios forestales con predicción diaria en la cuenca del Río Balsas

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    La cuenca del río Balsas es una zona con disponibilidad hí - drica limitada, sin embargo exporta anualmente 490 hm 3 de agua a la cuenca del Valle de México por medio del sistema Cutzamala. Si los bosques de esta cuenca se deterioran, los recursos hídricos disminuirán y en consecuencia su volumen exportado también, por lo cual se debe identificar factores que favorecen la probabilidad de ocurrencia de incendios fo - restales en la cuenca. Así, podrá intervenirse de manera pre - ventiva en el manejo de estos fenómenos para aminorar la vulnerabilidad y deterioro de los recursos en la región. De manera equilibrada, los incendios forestales son necesarios para el restablecimiento natural de los ecosistemas, pero su frecuencia ha aumentado por causas antropógenas y la diná - mica climática. El objetivo de este estudio fue construir un modelo de regresión logística para la detección diaria de zo - nas con peligro de incendios forestales. Esta propuesta con - sideró variables topográficas, meteorológicas y antropógenas para el periodo de 2006 a 2009. Los resultados proporciona - ron una efectividad espacial y temporal mayor a 86 %. Una escala de peligro (bajo, moderado, alto y muy alto) fue pro - puesta de acuerdo con su probabilidad de ocurrencia. En el análisis, más de 85 % de los incendios ocurridos diariamen - te tuvieron categoría de alto y muy alto peligro de ignición. El mayor peligro se encontró en las cuencas de captación de las presas Valle de Bravo, Colorines-Chilesdo e Ixtapan del Oro, del sistema Cutzamala. Los resultados de este estudio sugieren que la metodología puede usarse para mejorar sis - temas de alerta contra incendios y complementar el diseño e ubicación estratégica de centros de mando, campamentos, torres-observatorio, y prioridades para equipamiento

    Spawning time of Acanthaster cf. solaris on the Great Barrier Reef inferred using qPCR quantification of embryos and larvae: do they know it’s Christmas?

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    Outbreaks of crown-of-thorns seastars (CoTS; Acanthaster spp.) are a major contributor to degradation of Indo-Pacific coral reefs. Understanding the dispersal and fate of planktonic life stages is crucial to understand and manage outbreaks, but visual detection of CoTS larvae is challenging. We apply a quantitative PCR (qPCR) assay to enumerate CoTS larvae in a 3-year time series of plankton samples from two reefs (Agincourt and Moore Reefs) on the Great Barrier Reef. Plankton surveys were complemented with settlement assays, and benthic surveys of juvenile and adult densities over time. Only one out of 109 plankton samples from Agincourt Reef had detectable CoTS mtDNA compared to 41 out of 575 samples from Moore Reef. This may be explained by differences in adult densities, or differences in connectivity and larval retention. Detections of larval CoTS were restricted to summer (November–February), with first detections each year coinciding with water temperatures reaching 28 °C and peak detections late December. A disproportionate number of larval detections occurred in 7 days around full moon. Complementary sampling of settlement and post-settlement life stages confirmed that elevated densities of CoTS larvae at Moore Reef translated to high rates of settlement adding to infestations at this reef. Moreover, there were declines in the detection of larvae, as well densities of juvenile and adult CoTS at Moore Reef, in 2017 and 2018. This study demonstrates that qPCR for genetic identification and quantification of larvae can assist to elucidate life history parameters of nuisance species difficult to obtain with other tools

    How AP CS A Matches College Courses

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    ABSTRACT The Advanced Placement (AP) Program provides a framework for high school students to obtain college credit and/or placement for work done in high school. Toward this end, the College Board outlines course descriptions and organizes examinations in several dozen disciplines, including computer science. To meet its goals, each AP course must align with college courses, so students taking an AP course will master needed content Several approaches are used to monitor this connection between AP courses and collegelevel courses. This session will review these approaches, considering how the AP CS A course matches introductory college computer science courses

    Comparison of different sources of platelet-rich plasma as treatment option for infertility-causing endometrial pathologies

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    Objective. To study the effect of human plasma from different sources such as umbilical cord blood and adult blood platelet-rich plasma (PRP) on the regeneration of endometrial damage. Design. Composition analysis, in vitro approaches and a pre-clinical murine model using plasma to promote endometrial regeneration. Setting. Hospital and university laboratories. Patients/Animals. Adult plasma from 4 Atrophy patients and one fertile woman, commercial umbilical cord plasma and uterine-damaged NOD/SCID mice model were used. Intervention(s). Endometrial stromal cells from primary culture and an endometrial stem cell line were cultured in vitro and uterine-damaged NOD/SCID mice were treated with plasma samples from several origins. Main Outcome Measure(s). All plasma samples contain molecules with a high potential for regeneration (SCF, PDGFBB, THBS1, VWF). Furthermore, the highest increase in in vitro proliferation and migration rate was found when endometrial stromal cells were treated with umbilical cord plasma, adult PRP also revealed a significant increment. In the mouse model, a higher expression of Ki67 and Hoxa10 in the endometrium was detected after applying adult PRP and the proteomic analysis revealed a specific protein expression profile depending on the treatment. The damaged uterine tissue showed more pro22 regenerative markers after applying umbilical cord plasma (Stat5a, Uba3, Thy1) in comparison to the other treatments (non-activated umbilical cord plasma, activated adult PRP and not treatment). Conclusion. Human PRP possesses regeneration properties usable for endometrial pathologies. Besides that, these regenerative effects seem to be more apparent when the source of obtaining is umbilical cord blood

    Mapping the specific pathways to early-onset mental health disorders : the "Watch Me Grow for REAL" study protocol

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    Background: From birth, the human propensity to selectively attend and respond to critical super-stimuli forms the basis of future socio-emotional development and health. In particular, the first super-stimuli to preferentially engage and elicit responses in the healthy newborn are the physical touch, voice and face/eyes of caregivers. From this grows selective attention and responsiveness to emotional expression, scaffolding the development of empathy, social cognition, and other higher human capacities. In this paper, the protocol for a longitudinal, prospective birth-cohort study is presented. The major aim of this study is to map the emergence of individual differences and disturbances in the system of social-Responsiveness, Emotional Attention, and Learning (REAL) through the first 3 years of life to predict the specific emergence of the major childhood mental health problems, as well as social adjustment and impairment more generally. A further aim of this study is to examine how the REAL variables interact with the quality of environment/caregiver interactions. Methods/Design: A prospective, longitudinal birth-cohort study will be conducted. Data will be collected from four assessments and mothers' electronic medical records. Discussion: This study will be the first to test a clear developmental map of both the unique and specific causes of childhood psychopathology and will identify more precise early intervention targets for children with complex comorbid conditions

    Bats Use Magnetite to Detect the Earth's Magnetic Field

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    While the role of magnetic cues for compass orientation has been confirmed in numerous animals, the mechanism of detection is still debated. Two hypotheses have been proposed, one based on a light dependent mechanism, apparently used by birds and another based on a “compass organelle” containing the iron oxide particles magnetite (Fe3O4). Bats have recently been shown to use magnetic cues for compass orientation but the method by which they detect the Earth's magnetic field remains unknown. Here we use the classic “Kalmijn-Blakemore” pulse re-magnetization experiment, whereby the polarity of cellular magnetite is reversed. The results demonstrate that the big brown bat Eptesicus fuscus uses single domain magnetite to detect the Earths magnetic field and the response indicates a polarity based receptor. Polarity detection is a prerequisite for the use of magnetite as a compass and suggests that big brown bats use magnetite to detect the magnetic field as a compass. Our results indicate the possibility that sensory cells in bats contain freely rotating magnetite particles, which appears not to be the case in birds. It is crucial that the ultrastructure of the magnetite containing magnetoreceptors is described for our understanding of magnetoreception in animals
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