775 research outputs found
Morning Increase in Onset of Ischemic Stroke
The Time of Onset of Ischemic Stroke Was Determined for 1,167 of 1,273 Patients during the Collection of Data by Four Academic Hospital Centers between June 30, 1983, and June 30, 1986. More Strokes Occurred in Awake Patients from 10:00 Am to Noon Than during Any Other 2-Hour Interval. the Incidence of Stroke Onset Declined Steadily during the Remainder of the Day and Early Evening. the Onset of Stroke is Least Likely to Occur in the Late Evening, Before Midnight. © 1989 American Heart Association, Inc
Perspectives on Astrophysics Based on Atomic, Molecular, and Optical (AMO) Techniques
About two generations ago, a large part of AMO science was dominated by
experimental high energy collision studies and perturbative theoretical
methods. Since then, AMO science has undergone a transition and is now
dominated by quantum, ultracold, and ultrafast studies. But in the process, the
field has passed over the complexity that lies between these two extremes. Most
of the Universe resides in this intermediate region. We put forward that the
next frontier for AMO science is to explore the AMO complexity that describes
most of the Cosmos.Comment: White paper submission to the Decadal Assessment and Outlook Report
on Atomic, Molecular, and Optical (AMO) Science (AMO 2020
Variation in the Meaning of Alarm Calls in Verreaux’s and Coquerel’s Sifakas (Propithecus verreauxi, P. coquereli)
The comprehension and usage of primate alarm calls appear to be influenced by social learning. Thus, alarm calls provide flexible behavioral mechanisms that may allow animals to develop appropriate responses to locally present predators. To study this potential flexibility, we compared the usage and function of 3 alarm calls common to 2 closely related sifaka species (Propithecus verreauxi and P. coquereli), in each of 2 different populations with different sets of predators. Playback studies revealed that both species in both of their respective populations emitted roaring barks in response to raptors, and playbacks of this call elicited a specific anti-raptor response (look up and climb down). However, in Verreaux’s sifakas, tchi-faks elicited anti-terrestrial predator responses (look down, climb up) in the population with a higher potential predation threat by terrestrial predators, whereas tchi-faks in the other population were associated with nonspecific flight responses. In both populations of Coquerel’s sifakas, tchi-fak playbacks elicited anti-terrestrial predator responses. More strikingly, Verreaux’s sifakas exhibited anti-terrestrial predator responses after playbacks of growls in the population with a higher threat of predation by terrestrial predators, whereas Coquerel’s sifakas in the raptor-dominated habitat seemed to associate growls with a threat by raptors; the 2 other populations of each species associated a mild disturbance with growls. We interpret this differential comprehension and usage of alarm calls as the result of social learning processes that caused changes in signal content in response to changes in the set of predators to which these populations have been exposed since they last shared a common ancestor
Gender equality and religion:a multi-faith exploration of young adults’ narratives
This paper presents findings from research on young adults in the UK from diverse religious backgrounds. Utilizing questionnaires, interviews, and video diaries it assesses how religious young adults understood and managed the tensions in popular discourse between gender equality as an enshrined value and aspirational narrative, and religion as purportedly instituting gender inequality. We show that, despite varied understandings, and the ambivalence and tension in managing ideal and practice, participants of different religious traditions and genders were committed to gender equality. Thus, they viewed gender-unequal practices within their religious cultures as an aberration from the essence of religion. In this way, they firmly rejected the dominant discourse that religion is inherently antithetical to gender equality
A Standard Platform for Testing and Comparison of MDAO Architectures
The Multidisciplinary Design Analysis and Optimization (MDAO) community has developed a multitude of algorithms and techniques, called architectures, for performing optimizations on complex engineering systems which involve coupling between multiple discipline analyses. These architectures seek to efficiently handle optimizations with computationally expensive analyses including multiple disciplines. We propose a new testing procedure that can provide a quantitative and qualitative means of comparison among architectures. The proposed test procedure is implemented within the open source framework, OpenMDAO, and comparative results are presented for five well-known architectures: MDF, IDF, CO, BLISS, and BLISS-2000. We also demonstrate how using open source soft- ware development methods can allow the MDAO community to submit new problems and architectures to keep the test suite relevant
The European Legal Framework on Cybercrime
This article analyzes the European legal framework on cybercrime. Initially, it argues the challenges of cybercrime to traditional criminal justice systems. Subsequently, it focuses on the criminal law framework on cybercrime with a mainly European perspective. The European legal framework provides a three-path solution: the reduction of frictions among national legislations, the introduction of new investigative powers and the facilitation of international cooperation. The article presents and discusses each solution. Further, it argues that the effective implementation of the main legal instruments does not seem to depend on the legal enforceability of these international measures. Contrarily, other, non legal, factors such as national security, politics, the economy and the public opinion appear to stimulate the spontaneous implementation of the European legal framework. In this context, the added value of the EU action is rather low, although the Treaty of Lisbon and the Stockholm Programme may improve this situation in the long ter
Scheduling M2M traffic over LTE uplink of a dense small cell network
We present an approach to schedule Long Term Evolution (LTE) uplink (UL) Machine-to-Machine (M2M) traffic in a densely deployed heterogeneous network, over the street lights of a big boulevard for smart city applications. The small cells operate with frequency reuse 1, and inter-cell interference (ICI) is a critical issue to manage. We consider a 3rd Generation Partnership Project (3GPP) compliant scenario, where single-carrier frequency-division multiple access (SC-FDMA) is selected as the multiple access scheme, which requires that all resource blocks (RBs) allocated to a single user have to be contiguous in the frequency within each time slot. This adjacency constraint limits the flexibility of the frequency-domain packet scheduling (FDPS) and inter-cell interference coordination (ICIC), when trying to maximize the scheduling objectives, and this makes the problem NP-hard. We aim to solve a multi-objective optimization problem, to maximize the overall throughput, maximize the radio resource usage and minimize the ICI. This can be modelled through a mixed-integer linear programming (MILP) and solved through a heuristic implementable in the standards. We propose two models. The first one allocates resources based on the three optimization criteria, while the second model is more compact and is demonstrated through numerical evaluation in CPLEX, to be equivalent in the complexity, while it performs better and executes faster. We present simulation results in a 3GPP compliant network simulator, implementing the overall protocol stack, which support the effectiveness of our algorithm, for different M2M applications, with respect to the state-of-the-art approaches
Pareto optimality solution of the multi-objective photogrammetric resection-intersection problem
Reconstruction of architectural structures from photographs has recently experienced intensive efforts in computer vision research. This is achieved through the solution of nonlinear least squares (NLS) problems to obtain accurate structure and motion estimates. In Photogrammetry, NLS contribute to the determination of the 3-dimensional (3D) terrain models from the images taken from photographs. The traditional NLS approach for solving the resection-intersection problem based on implicit formulation on the one hand suffers from the lack of provision by which the involved variables can be weighted. On the other hand, incorporation of explicit formulation expresses the objectives to be minimized in different forms, thus resulting in different parametric values for the estimated parameters at non-zero residuals. Sometimes, these objectives may conflict in a Pareto sense, namely, a small change in the parameters results in the increase of one objective and a decrease of the other, as is often the case in multi-objective problems. Such is often the case with error-in-all-variable (EIV) models, e.g., in the resection-intersection problem where such change in the parameters could be caused by errors in both image and reference coordinates.This study proposes the Pareto optimal approach as a possible improvement to the solution of the resection-intersection problem, where it provides simultaneous estimation of the coordinates and orientation parameters of the cameras in a two or multistation camera system on the basis of a properly weighted multi-objective function. This objective represents the weighted sum of the square of the direct explicit differences of the measured and computed ground as well as the image coordinates. The effectiveness of the proposed method is demonstrated by two camera calibration problems, where the internal and external orientation parameters are estimated on the basis of the collinearity equations, employing the data of a Manhattan-type test field as well as the data of an outdoor, real case experiment. In addition, an architectural structural reconstruction of the Merton college court in Oxford (UK) via estimation of camera matrices is also presented. Although these two problems are different, where the first case considers the error reduction of the image and spatial coordinates, while the second case considers the precision of the space coordinates, the Pareto optimality can handle both problems in a general and flexible way
Combinatoriality in the vocal systems of nonhuman animals
A key challenge in the field of human language evolution is the identification of the selective conditions that gave rise to language's generative nature. Comparative data on nonhuman animals provides a powerful tool to investigate similarities and differences among nonhuman and human communication systems and to reveal convergent evolutionary mechanisms. In this article, we provide an overview of the current evidence for combinatorial structures found in the vocal system of diverse species. We show that considerable structural diversity exits across and within species in the forms of combinatorial structures used. Based on this we suggest that a fine‐grained classification and differentiation of combinatoriality is a useful approach permitting systematic comparisons across animals. Specifically, this will help to identify factors that might promote the emergence of combinatoriality and, crucially, whether differences in combinatorial mechanisms might be driven by variations in social and ecological conditions or cognitive capacities
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