573 research outputs found
No Man Is An Island In Defense Procurement: Developments In EU Defense Procurement Regulation And Its Implications For The U.S.
The Russian invasion of Ukraine and the United Kingdomâs exit from the European Union have focused minds on the EUâs role as a defense actor. In the context of defense procurement, this includes whether the EU should itself co-fund cooperative programmes with Member States (through the European Defense Fund, for example, and Permanent Structured Cooperation (PESCO) initiatives among Member States), what can be commonly procured (and what cannot, e.g., due to prohibitions against offsets), and how (for example, under the competing constraints of Article 346 of the Treaty on Functioning of the European Union (TFEU) and the 2009 European Defense Directive). The United States faces the obvious dilemma of needing to be seen to encourage EU initiatives which, if successful, would reduce reliance on the United States within the North Atlantic Treaty Organization (NATO) while also securing U.S. industryâs continued access to the European defence market(s), for example through Foreign Military Sales (FMS) and under the reciprocal defense procurement agreements which open transatlantic defense markets. In the hope of advancing transatlantic cooperation in the broader procurement law community, this piece explores the latest EU initiatives in defense and security, with a particular emphasis on implications for the United States
Tale of Three Regulatory Regimes -- Dynamic, Distracted and Dysfunctional: Sweden, the United Kingdom and the United States
It was the best of times, it was the worst of times -- a year marked by genuine progress in public procurement law in some nations, and partial paralysis in others. This article presents the experience of Sweden (as part of the European Union), the United Kingdom (which is slated soon to depart from the EU, via âBrexitâ), and the United States (in the first year of the Trump administration). While Sweden and other members of the European Union continue to develop a vital and evolving body of public procurement law, the United Kingdom has been distracted by Brexit, and the United States made, in 2017, almost no regulatory progress at all -- though stasis itself yielded some interesting insights. This piece proceeds in three parts, prepared primarily by Andrea Sundstrand (Part II, on Sweden and the European Union), Michael Bowsher (Part III, on the United Kingdom) and Christopher Yukins (Introduction, Part IV on the United States, and Conclusion)
The fidelity of dynamic signaling by noisy biomolecular networks
This is the final version of the article. Available from Public Library of Science via the DOI in this record.Cells live in changing, dynamic environments. To understand cellular decision-making, we must therefore understand how fluctuating inputs are processed by noisy biomolecular networks. Here we present a general methodology for analyzing the fidelity with which different statistics of a fluctuating input are represented, or encoded, in the output of a signaling system over time. We identify two orthogonal sources of error that corrupt perfect representation of the signal: dynamical error, which occurs when the network responds on average to other features of the input trajectory as well as to the signal of interest, and mechanistic error, which occurs because biochemical reactions comprising the signaling mechanism are stochastic. Trade-offs between these two errors can determine the system's fidelity. By developing mathematical approaches to derive dynamics conditional on input trajectories we can show, for example, that increased biochemical noise (mechanistic error) can improve fidelity and that both negative and positive feedback degrade fidelity, for standard models of genetic autoregulation. For a group of cells, the fidelity of the collective output exceeds that of an individual cell and negative feedback then typically becomes beneficial. We can also predict the dynamic signal for which a given system has highest fidelity and, conversely, how to modify the network design to maximize fidelity for a given dynamic signal. Our approach is general, has applications to both systems and synthetic biology, and will help underpin studies of cellular behavior in natural, dynamic environments.We acknowledge support from a Medical Research Council and Engineering and Physical Sciences Council funded Fellowship in Biomedical Informatics (CGB) and a Scottish Universities Life Sciences Alliance chair in Systems Biology (PSS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
A High-Resolution Study of the HI Content of Local Group Dwarf Irregular Galaxy WLM
Dwarf irregular galaxies are unique laboratories for studying the interaction
between stars and the interstellar medium in low mass environments. We present
the highest spatial resolution observations to date of the neutral hydrogen
content of the Local Group dwarf irregular galaxy WLM. We find that WLM's
neutral hydrogen distribution is typical for a galaxy of its type and size and
derive an HI mass of 6.3e7 Msun for WLM. In addition, we derive an HI extent
for WLM of 30 arcmin, which is much less than the 45 arcmin extent found by
Huchtmeier, Seiradakis, and Materne (1981). We show that the broken ring of
high column density neutral hydrogen surrounding the center of WLM is likely
the result of star formation propagating out from the center of the galaxy. The
young stars and Ha emission in this galaxy are mostly correlated with the high
column density neutral hydrogen. The gap in the central ring is the result of
star formation in that region using up, blowing out, or ionizing all of the
neutral hydrogen. Like many late-type galaxies, WLM's velocity field is
asymmetric with the approaching (northern) side appearing to be warped and a
steeper velocity gradient for the approaching side than for the receding side
in the inner region of the galaxy. We derive a dynamical mass for WLM of 2.16e9
Msun.Comment: 38 pages, 15 figures, 5 tables, accepted by AJ, high resolution
version at http://www.astro.wisc.edu/~kepley/kepley_wlm.p
The Factory and the Beehive. II. Activity and Rotation is Praesepe and the Hyades
Open clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star\u27s lifetime. We present the results of a comparative study of the relationship between stellar rotation and activity in two benchmark open clusters: Praesepe and the Hyades. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at 600 Myr. We have compiled a sample of 720 spectraâmore than half of which are new observationsâfor 516 high-confidence members of Praesepe; we have also obtained 139 new spectra for 130 high-confidence Hyads. We have also collected rotation periods (P rot) for 135 Praesepe members and 87 Hyads. To compare Hα emission, an indicator of chromospheric activity, as a function of color, mass, and Rossby number Ro , we first calculate an expanded set of Ï values, with which we can obtain the Hα to bolometric luminosity ratio, L Hα/L bol, even when spectra are not flux-calibrated and/or stars lack reliable distances. Our Ï values cover a broader range of stellar masses and colors (roughly equivalent to spectral types from K0 to M9), and exhibit better agreement between independent calculations, than existing values. Unlike previous authors, we find no difference between the two clusters in their Hα equivalent width or L Hα/L bol distributions, and therefore take the merged Hα and P rot data to be representative of 600 Myr old stars. Our analysis shows that Hα activity in these stars is saturated for . Above that value activity declines as a power-law with slope , before dropping off rapidly at Ro 0.4. These data provide a useful anchor for calibrating the age-activity-rotation relation beyond 600 Myr
Beyond simultaneity: temporal interdependence of behaviour is key to affiliative effects of interpersonal synchrony in children
Interpersonal synchrony (IS) is the temporal co-ordination of behavior during social interactions. IS acts as a social cue signifying affiliation, both when children witness IS between others and when they experience it themselves. However, it is unclear which temporal qualities of IS produce these effects, and why. We hypothesized that the simultaneity and temporal regularity of partnersâ actions would each influence affiliation judgements, and that subjective perceptions of IS (âtogethernessâ) would play a role in mediating these relations. In two online studies, children aged 4-11 years listened to a pair of children tapping together (witnessed IS; N=68) or themselves tapped with another child (experienced IS; N=63). Tapping partners were presented as real but were virtual. The simultaneity and regularity of their tapping was systematically manipulated across trials. For witnessed IS, both the simultaneity and regularity of partnersâ tapping significantly positively affected the perceived degree of affiliation between them. These effects were mediated by the perceived togetherness of the tapping. No affiliative effects of IS were found in the experienced IS condition. Our findings suggest that both the simultaneity and regularity of partnersâ actions influence childrenâs affiliation judgements when witnessing IS, via elicited perceptions of togetherness. We conclude that temporal interdependence â which includes but is not limited to simultaneity of action â is responsible for inducing perceptions of affiliation during witnessed IS
PRIVATE SAVINGS IN TRANSITION ECONOMIES: ARE THERE TERMS OF TRADE SHOCKS?
The paper examines the impact of terms of trade shocks on private savings in the transition economies after accounting for the effect of other determinants. Economic agents in the transition economies are subject to tight credit constraints which are more pronounced during bad state of nature. Thus, adverse shocks to commodity prices in the world market can force them to reduce savings by a larger amount than they would otherwise have. Empirical analysis using a dynamic panel model and data from twenty one transition economies confirm that most of the determinants of savings identified in the literature also apply to the transition economies. Favorable movements in both the permanent and transitory components of the terms of trade have a significant positive impact on private savings with transitory movements having a larger impact than the permanent component. This reflects the lack of access to foreign borrowing that many of the transition economies have faced during the last decade. Although the impact of terms of trade shocks are found to be asymmetric, the magnitude of the impact appears to be small. The results are robust for alternative estimators, determinants, and country groupings.http://deepblue.lib.umich.edu/bitstream/2027.42/39958/3/wp572.pd
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Smoking and vaping alter genes related to mechanisms of SARS-CoV-2 susceptibility and severity.
Evidence for the impact of smoking on COVID-19 is contradictory, and there is little research on vaping. Here we provide greater clarity on mechanisms perturbed by tobacco cigarette, electronic cigarette and nicotine exposures that may impact the risks of infection and/or disease severity.Following PRISMA guidelines, OVID and Web of Science databases were searched. Study design and exposure-induced gene expression changes were extracted. Each study was quality assessed and higher confidence scores were assigned to genes consistently changed across multiple studies following the same exposure. These genes were used to explore pathways significantly altered following exposure.125 studies provided data on 480 genes altered by exposure to tobacco cigarettes, e-cigarettes, nicotine or SARS-CoV-2. Genes involved in both SARS-CoV-2 viral-entry and inflammation were changed following exposure. Pathway analysis revealed that many of those genes with high confidence scores are involved in common cellular processes relating to hyperinflammatory immune responses.Exposure to tobacco cigarettes, e-cigarettes, or nicotine, may therefore impact initial host-pathogen interactions and disease severity. Smokers and vapers of e-cigarettes with nicotine, could potentially be at increased risk of SARS-CoV-2 infection, associated cytokine storm, and acute respiratory distress syndrome. However, further research is required, particularly on e-cigarettes, to determine the biological mechanisms involved in perturbation of viral-entry genes and host-pathogen interactions and subsequent responses within the respiratory tract. This will improve our physiological understanding of the impact of smoking and vaping on COVID-19, informing public health advice and providing improved guidance for management of SARS-CoV-2 and other respiratory viruses
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