7,956 research outputs found
Three-dimensional structure of the Upper Scorpius association with the Gaia first data release
Using new proper motion data from recently published catalogs, we revisit the
membership of previously identified members of the Upper Scorpius association.
We confirmed 750 of them as cluster members based on the convergent point
method, compute their kinematic parallaxes and combined them with Gaia
parallaxes to investigate the 3D structure and geometry of the association
using a robust covariance method. We find a mean distance of ~pc
and show that the morphology of the association defined by the brightest (and
most massive) stars yields a prolate ellipsoid with dimensions of
~pc, while the faintest cluster members define a more
elongated structure with dimensions of ~pc. We
suggest that the different properties of both populations is an imprint of the
star formation history in this region.Comment: 5 pages, 1 figure, MNRAS letters (in press
Alien Registration- Landen, Isabelle B. (Millinocket, Penobscot County)
https://digitalmaine.com/alien_docs/8154/thumbnail.jp
Spindle-E acts antivirally against alphaviruses in mosquito cells
Mosquitoes transmit several human- and animal-pathogenic alphaviruses (Togaviridae
family). In alphavirus-infected mosquito cells two different types of virus-specific small RNAs are
produced as part of the RNA interference response: short-interfering (si)RNAs and
PIWI-interacting (pi)RNAs. The siRNA pathway is generally thought to be the main antiviral
pathway. Although an antiviral activity has been suggested for the piRNA pathway its role in host
defences is not clear. Knock down of key proteins of the piRNA pathway (Ago3 and Piwi5) in Aedes
aegypti-derived cells reduced the production of alphavirus chikungunya virus (CHIKV)-specific
piRNAs but had no effect on virus replication. In contrast, knock down of the siRNA pathway key
protein Ago2 resulted in an increase in virus replication. Similar results were obtained when
expression of Piwi4 was silenced. Knock down of the helicase Spindle-E (SpnE), an essential
co-factor of the piRNA pathway in Drosophila melanogaster, resulted in increased virus replication
indicating that SpnE acts as an antiviral against alphaviruses such as CHIKV and the related
Semliki Forest virus (SFV). Surprisingly, this effect was found to be independent of the siRNA and
piRNA pathways in Ae. aegypti cells and specific for alphaviruses. This suggests a small
RNA-independent antiviral function for this protein in mosquitoes
Not wacky vs. definitely wacky: a study of scalar adverbs in pretrained language models
Vector-space models of word meaning all assume that words occurring in similar contexts have similar meanings. Words that are similar in their topical associations but differ in their logical force tend to emerge as semantically close – creating well-known challenges for NLP applications that involve logical reasoning. Pretrained language models such as BERT, RoBERTa, GPT-2, and GPT-3 hold the promise of performing better on logical tasks than classic static word embeddings. However, reports are mixed about their success. Here, we advance this discussion through a systematic study of scalar adverbs, an under-explored class of words with strong logical force. Using three different tasks involving both naturalistic social media data and constructed examples, we investigate the extent to which BERT, RoBERTa, GPT-2 and GPT-3 exhibit knowledge of these common words. We ask: 1) Do the models distinguish amongst the three semantic categories of MODALITY, FREQUENCY and DEGREE? 2) Do they have implicit representations of full scales from maximally negative to maximally positive? 3) How do word frequency and contextual factors impact model performance? We find that despite capturing some aspects of logical meaning, the models still have obvious shortfalls
Inheritable Effect of Unpredictable Maternal Separation on Behavioral Responses in Mice
The long-term impact of early stress on behavior and emotions is well documented in humans, and can be modeled in experimental animals. In mice, maternal separation during early postnatal development induces poor and disorganized maternal care, and results in behavioral deficits that persist through adulthood. Here, we examined the long-term effect of unpredictable maternal separation combined with maternal stress on behavior and its transmissibility. We report that unpredictable maternal separation from birth to postnatal day 14 in C57Bl/6J mice has mild behavioral effects in the animals when adult, but that its combination with maternal stress exacerbates this effect. Further, the behavioral deficits are transmitted to the following generation through females, an effect that is independent of maternal care and is not affected by cross-fostering. The combined manipulation does not alter basic components of the hypothalamic–pituitary–adrenal axis but decreases the expression of the corticotropin releasing factor receptor 2 (CRFR2) in several nuclei of the amygdala and the hypothalamus in the brain of maternal-separated females. These results suggest a non-genomic mode of transmission of the impact of early stress in mice
The impact of the grazing animal on phosphorus, nitrogen, potassium and suspended solids loss from grazed pastures, Part A
Teagasc wishes to acknowledge the support of the Environmental Research Technological
Development and Innovation (ERTDI) Programme under the Productive Sector Operational
Programme which was financed by the Irish Government under the National Development
Plan 2000-2006.End of project reportIn Ireland 90% of the 4.2 million ha of farmland is grassland. Phosphorus deficiency limited grassland production in Ireland and this was corrected by chemical fertiliser use in the 1960s and 1970s. The increased inputs of fertilisers led to increased intensification of grassland with a doubling of grass yield and of grazing animal numbers, from about 3 million to over 6 million livestock units. There is little information on relative contribution of increased chemical fertiliser use compared to increased grazing animal numbers on phosphorus loss to water. The main objective of this study was to obtain information on nutrient loss, particularly phosphorus, in overland flow from cut and grazed grassland plots, with a range of soil test phosphorus levels over three years and implications.Environmental Protection Agenc
Key economic performance indicator
The East Africa Dairy Development (EADD) project is a regional industry development program and implemented by a consortium of partners. It is currently being piloted
in 18 sites in Kenya, 8 in Rwanda and 27 in Uganda. The overall goal of the project is to transform the lives of 179,000 families, or about 1 million people, by doubling
household dairy income in 10 years through integrated interventions in dairy production, market access and knowledge application. This brief highlights key results of a baseline survey of
the economic performance analysis of dairy farms in project sites in Kenya, Rwanda and Uganda. The focus is on production and marketing aspects to establish a benchmark against which future economic performances
of the project beneficiaries will be assessed during the project monitoring, review and final impact evaluations.
Details are available in the baseline survey report No. 5
Influence of Fluid-Structure Interaction on Microcantilever Vibrations: Applications to Rheological Fluid Measurement and Chemical Detection
At the microscale, cantilever vibrations depend not only on the microstructure’s properties and geometry but also on the properties of the surrounding medium. In fact, when a microcantilever vibrates in a fluid, the fluid offers resistance to the motion of the beam. The study of the influence of the hydrodynamic force on the microcantilever’s vibrational spectrum can be used to either (1) optimize the use of microcantilevers for chemical detection in liquid media or (2) extract the mechanical properties of the fluid. The classical method for application (1) in gas is to operate the microcantilever in the dynamic transverse bending mode for chemical detection. However, the performance of microcantilevers excited in this standard out-of-plane dynamic mode drastically decreases in viscous liquid media. When immersed in liquids, in order to limit the decrease of both the resonant frequency and the quality factor, alternative vibration modes that primarily shear the fluid (rather than involving motion normal to the fluid/beam interface) have been studied and tested: these include inplane vibration modes (lateral bending mode and elongation mode). For application (2), the classical method to measure the rheological properties of fluids is to use a rheometer. To overcome the limitations of this classical method, an alternative method based on the use of silicon microcantilevers is presented. The method, which is based on the use of analytical equations for the hydrodynamic force, permits the measurement of the complex shear modulus of viscoelastic fluids over a wide frequency range
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