977 research outputs found
Об одной математической модели мировой динамики и устойчивости развития
Викладено одну модифiкацiю моделi Форрестера свiтової динамiки. У запропонованiй моделi введено фактор невдоволення на кожному системному рiвнi моделi. Встановлено умови стiйкого розвитку вiдносно двох мiр у межах даної моделi.The paper is devoted to the discussion of a modification of Forrester’s model of the world dynamics. In the model, the “factor of discontent” is taken into account via the dynamics of public opinion on the development of separate system levels. We also established the conditions of sustainable development with respect to two measures
Cysteine 230 is essential for the structure and activity of the cytotoxic ligand TRAIL.
Unlike other tumor necrosis factor family members, the cytotoxic ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/Apo-2L contains an unpaired cysteine residue (Cys(230)) in its receptor-binding domain. Here we show that the biological activity of both soluble recombinant TRAIL and cell-associated, full-length TRAIL is critically dependent on the presence of Cys(230). Mutation of Cys(230) to alanine or serine strongly affected its ability to kill target cells. Binding to its receptors was decreased by at least 200-fold, and the stability of its trimeric structure was reduced. In recombinant TRAIL, Cys(230) was found engaged either in interchain disulfide bridge formation, resulting in poorly active TRAIL, or in the chelation of one zinc atom per TRAIL trimer in the active, pro-apoptotic form of TRAIL
The properties of glass fibres after conditioning at composite recycling temperatures
Results are presented on E-glass fibre properties after thermal conditioning up to 600°C. Thermal conditioning led to up to 70% strength degradation. Tensile strength and failure strain of silane-coated fibres were relatively stable up to 250°C but exhibited a precipitous drop at higher conditioning temperatures. Unsized fibres exhibited a linear decrease in strength with increasing conditioning temperature. Little significant strength regeneration was obtained from a range of acid and silane post-treatments of heat conditioned fibres. A simple analysis of the cumulative fibre strength probability resulted in more useful understanding than the Weibull method. The modulus of both fibre types increased linearly with conditioning temperature. Evidence was found of a slow time-dependent reduction of glass fibre modulus during storage in an uncontrolled environment. The results are discussed in terms of the changes in surface coating and bulk glass structure during heat conditioning and the role of the glass fibre water content
User-Centered Evaluation of a Discovery Layer System with Google Scholar
Discovery layer systems allow library users to obtain search results from multiple library resources and view results in a consistent format. The implementation of a discovery layer is expected to simplify users’ workflow of searching for scholarly information. Previous studies on discovery layer systems focused on functionality and content, but not quality of search results from the user’s perspective. The objective of this study was to obtain users’ assessment of search results of a discovery layer system (Ex Libris Primo®) and compare that with a widely used scholarly search tool (Google Scholar). Results showed that Primo’s search results relevancy is comparable to Google Scholar, but it received significantly lower usability and preference ratings. A number of usability issues of Primo were also identified from the study. Results of the study are used to improve the interface of Primo and adjust relevancy ranking options. The empirical method of search results assessment and feedback collection used in this study can be extended to similar user-centered system implementation and evaluation efforts
Injection testosterone and adverse cardiovascular events: A case-crossover analysis
Context: Exogenous testosterone administration may affect blood clotting, polycythaemia, and may increase atherosclerosis, though any association with cardiovascular events is unclear. While the literature is inconclusive, some studies have suggested testosterone use may increase short-term risk of cardiovascular events and stroke, and injection testosterone may convey higher risks than other dosage forms. Objective: We sought to evaluate the short-term cardiovascular risk of receiving injection testosterone. Design: We conducted a case-crossover analysis comparing injection testosterone exposure in the 7 days prior to an outcome event to referent windows in the past to estimate the acute association of cardiovascular outcomes with the receipt of testosterone injections. Patients: We identified adult male testosterone users hospitalized with myocardial infarction (MI), stroke or a composite of MI, stroke or unstable angina in US commercial claims (2000-2013) or Medicare (2007-2010) databases. Measurements: We identified testosterone use for the patients from pharmacy dispensing claims or in-office procedure codes in the insurance billing data. Results: We identified 2898 commercially insured men with events and recent testosterone use, and 339 from Medicare. Injected testosterone was associated with an increased risk of adverse events (composite outcome of myocardial infarction, stroke or unstable angina) in the immediate postinjection period for the older, Medicare population only: commercial insurance, odds ratios (OR) = 0.98 (95% confidence intervals [CI]: 0.86-1.12); Medicare, OR = 1.45 (1.07, 1.98). This association was either greatly attenuated or not present when evaluating receipt of any testosterone dosage forms (injection, gel, patch, implant): commercial insurance, OR = 1.01 (0.92, 1.11); Medicare, OR = 1.26 (95% CI: 0.98-1.63). Conclusions: Testosterone injections were uniquely associated with short-term risk of acute cardio- and cerebrovascular events in older adult men following injection receipt
Optically induced coherent intra-band dynamics in disordered semiconductors
On the basis of a tight-binding model for a strongly disordered semiconductor
with correlated conduction- and valence band disorder a new coherent dynamical
intra-band effect is analyzed. For systems that are excited by two, specially
designed ultrashort light-pulse sequences delayed by tau relatively to each
other echo-like phenomena are predicted to occur. In addition to the inter-band
photon echo which shows up at exactly t=2*tau relative to the first pulse, the
system responds with two spontaneous intra-band current pulses preceding and
following the appearance of the photon echo. The temporal splitting depends on
the electron-hole mass ratio. Calculating the population relaxation rate due to
Coulomb scattering, it is concluded that the predicted new dynamical effect
should be experimentally observable in an interacting and strongly disordered
system, such as the Quantum-Coulomb-Glass.Comment: to be published in Physical Review B15 February 200
The Myth of the Angry Atheist
Atheists are often portrayed in the media and elsewhere as angry individuals. Although atheists disagree with the pillar of many religions, namely the existence of a God, it may not necessarily be the case that they are angry individuals. The prevalence and accuracy of angry-atheist perceptions were examined in 7 studies with 1,677 participants from multiple institutions and locations in the United States. Studies 1–3 revealed that people believe atheists are angrier than believers, people in general, and other minority groups, both explicitly and implicitly. Studies 4–7 then examined the accuracy of these beliefs. Belief in God, state anger, and trait anger were assessed in multiple ways and contexts. None of these studies supported the idea that atheists are particularly angry individuals. Rather, these results support the idea that people believe atheists are angry individuals, but they do not appear to be angrier than other individuals in reality
Spatially resolved spectroscopy of monolayer graphene on SiO2
We have carried out scanning tunneling spectroscopy measurements on
exfoliated monolayer graphene on SiO to probe the correlation between its
electronic and structural properties. Maps of the local density of states are
characterized by electron and hole puddles that arise due to long range
intravalley scattering from intrinsic ripples in graphene and random charged
impurities. At low energy, we observe short range intervalley scattering which
we attribute to lattice defects. Our results demonstrate that the electronic
properties of graphene are influenced by intrinsic ripples, defects and the
underlying SiO substrate.Comment: 6 pages, 7 figures, extended versio
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