1,409 research outputs found
The ARGUS Vertex Trigger
A fast second level trigger has been developed for the ARGUS experiment which
recognizes tracks originating from the interaction region. The processor
compares the hits in the ARGUS Micro Vertex Drift Chamber to 245760 masks
stored in random access memories. The masks which are fully defined in three
dimensions are able to reject tracks originating in the wall of the narrow
beampipe of 10.5\,mm radius.Comment: gzipped Postscript, 27 page
Test exploration and validation using transaction level models
The complexity of the test infrastructure and test strategies in systems-on-chip approaches the complexity of the functional design space. This paper presents test design space exploration and validation of test strategies and schedules using transaction level models (TLMs). Since many aspects of testing involve the transfer of a significant amount of test stimuli and responses, the communication-centric view of TLMs suits this purpose exceptionally wel
Near-Surface Scattering From High Velocity Carbonates In West Texas
Seismic data acquired directly over near-surface limestone formations are commonly
observed to be of inferior quality. A possible cause for this degradation is scattering
in the near-subsurface by, e.g., the weathering layer, rough free-surface topography,
or heterogeneities such as cavities or clusters of vugs. We applied different numerical
scattering schemes to study the effects of each of these three scattering mechanisms.
For a particular dataset acquired in West Texas, we find that a weathering layer is
the dominant cause of noise on records acquired in valleys. However on mesas, nearsubsurface heterogeneity is the primary cause of scattered wave-energy. Topography
turned out to be of only secondary importance.
As additional attributes, we use energy-density and energy-flux vectors to study
the frequency dependence of the different scattering models. These attributes allow
us to study where energy concentrates and in which direction it flows. For example,
we observed that near sub-surface heterogeneities build up waveguides which efficiently
trap seismic energy near the surface.Massachusetts Institute of Technology. Borehole Acoustics and Logging Consortiu
Stochasticity and evolutionary stability
In stochastic dynamical systems, different concepts of stability can be
obtained in different limits. A particularly interesting example is
evolutionary game theory, which is traditionally based on infinite populations,
where strict Nash equilibria correspond to stable fixed points that are always
evolutionarily stable. However, in finite populations stochastic effects can
drive the system away from strict Nash equilibria, which gives rise to a new
concept for evolutionary stability. The conventional and the new stability
concepts may apparently contradict each other leading to conflicting
predictions in large yet finite populations. We show that the two concepts can
be derived from the frequency dependent Moran process in different limits. Our
results help to determine the appropriate stability concept in large finite
populations. The general validity of our findings is demonstrated showing that
the same results are valid employing vastly different co-evolutionary
processes
Junctional adhesion molecule (JAM)-C deficient C57BL/6 mice develop a severe hydrocephalus
The junctional adhesion molecule (JAM)-C is a widely expressed adhesion molecule regulating cell adhesion, cell polarity and inflammation. JAM-C expression and function in the central nervous system (CNS) has been poorly characterized to date. Here we show that JAM-C−/− mice backcrossed onto the C57BL/6 genetic background developed a severe hydrocephalus. An in depth immunohistochemical study revealed specific immunostaining for JAM-C in vascular endothelial cells in the CNS parenchyma, the meninges and in the choroid plexus of healthy C57BL/6 mice. Additional JAM-C immunostaining was detected on ependymal cells lining the ventricles and on choroid plexus epithelial cells. Despite the presence of hemorrhages in the brains of JAM-C−/− mice, our study demonstrates that development of the hydrocephalus was not due to a vascular function of JAM-C as endothelial re-expression of JAM-C failed to rescue the hydrocephalus phenotype of JAM-C−/− C57BL/6 mice. Evaluation of cerebrospinal fluid (CSF) circulation within the ventricular system of JAM-C−/− mice excluded occlusion of the cerebral aqueduct as the cause of hydrocephalus development but showed the acquisition of a block or reduction of CSF drainage from the lateral to the 3rd ventricle in JAM-C−/− C57BL/6 mice. Taken together, our study suggests that JAM-C−/− C57BL/6 mice model the important role for JAM-C in brain development and CSF homeostasis as recently observed in humans with a loss-of-function mutation in JAM-C
Епос літературознавчого ноесису
Рецензія на книгу: Сулима Микола. Книжиця у семи розділах: Літературно-критичні статті й дослідження. – К., 2006. – 424 с
Penetration of cefuroxime into the cerebrospinal fluid of patients with traumatic brain injury
Cefuroxime levels were measured in cerebrospinal fluid (CSF) and serum of four patients with traumatic brain injury following the implantation of intraventricular catheters. The levels ranged from 0.15 to 2.03 μg/mL in CSF and from 1.8 to 66.9 μg/mL in serum. No ventriculostomy related infections were detecte
Анализ влияния глобальных угроз на устойчивое развитие стран и регионов мира с помощью байесовских сетей доверия
Застосовано байєсівські мережі довіри для встановлення на якісному рівні причинно-наслідкових залежностей між глобальними загрозами і індексами сталого розвитку. Використання запропонованих в роботі методів синтезу мережі довіри та узагальнення результатів моделвання дозволило отримати цілісну інтерпетацію процесів впливу глобальних загроз на сталий розвиток країн і регіонів світу.Belief Bayesian Networks are used to establish the qualitative cause-effect relationships between global threats and indices of sustainable development. The method of belief network synthesis and the method of final results generalization were proposed. This made it possible to obtain a holistic understanding of effects of global threats to the sustainable development of countries and regions of the world
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