Sunday, February 22, 2015



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía

rss_1.0 Recursos de colección

CiteSeerX Scientific Literature Digital Library and Search Engine (3,324,511 recursos)
CiteSeerX is a scientific literature digital library and search engine that focuses primarily on the literature in computer and information science. CiteSeerx aims to improve the dissemination of scientific literature and to provide improvements in functionality, usability, availability, cost, comprehensiveness, efficiency, and timeliness in the access of scientific and scholarly knowledge

Mostrando recursos 1 - 20 de 3,208,552

1. Review Chaos in blood pressure control - Cd. Wagner; B. Nafz; P. B. Persson
A number of control mechanisms are comprised within blood pressure regulation, ranging from events on the cellular level up to circulating hormones. Despite their vast number, blood pressure fluctuations occur preferably within a certain range (under physiological conditions). A specific class of dynamic systems has been extensively studied over the past several years: nonlinear coupled systems, which often reveal a characteristic form of motion termed “chaos”. The system is restricted to a certain range in phase space, but the motion is never periodic. The attractor the system moves on has a non-integer dimension. What all chaotic systems have in common...

2. $rec.titulo
Areport in CMAJ characterized the 1997 deregulationof medical tuition in Ontario as “a nightmare formany medical students, ” and the dean of one medical school predicted that “the higher fees will create barriers.”1 When my students asked if the tuition hikes were unprece-dented, I was surprised to discover that medical historians and educators have ignored this question, and that few have asked how tuition influences who becomes a doctor. In this paper I review the actual and relative costs of medical tuition at 3 Ontario schools over the past 150 years, relating them to government funding and public ac-cess. My...

3. POPULATION ECOLOGY - Kenneth A. Schmidt; Æ Richard; S. Ostfeld; Kristina N. Smyth
Spatial heterogeneity in predator activity, nest survivorship,

4. $rec.titulo
The neutral model posits that random variation in extinction and speciation events, coupled with limited dispersal, can account for many community properties, including the relative abundance distribution. There are important analogies between this model in ecology and a three-tiered hierarchy of models in evolution (Hardy Weinburg, drift, drift and selection). Because it invokes random processes and is used in statistical tests of empirical data, the neutral model can be interpreted as a specialized form of a null model. However, the application and interpretation of neutral models differs from that of standard null models in three important ways: 1) whereas most...

5. Statistical Study of Speaker’s Peculiarities of Utterances into Phrases Segmentation - Boris Lobanov; Liliya Tsirulnik
The report is concerned with the experimental study of the idiosyncrasy of utterance-into-phrase segmentation observed in the speech of a popular Russian TV-anchorman and two TV-news readers. Comparative statistical estimation of relative frequencies of occurrence of pauses of various duration, frequencies of occurrence of phrases and pairs of phrases with a different number of accent units were computed, as well as frequencies of occurrence of phrase break between different consecutive parts of speech. On the basis of the results obtained a stochastic algorithm of personalized utterance-into-phrase segmentation is developed. The algorithm is intended to be implemented to the system of...

6. $rec.titulo - Y. Choie; Y. Chung Linear relations of theta series of genera of quadratic forms ✩

7. Journal of Leukocyte Biology 49:369-379 (1991) © 1991 Wiley-Liss, Inc. Distinct Patterns of Chemotactic Peptide-Induced Calcium Mobilization in Differentiated Myeloid Leukemia Cells and - Peripheral Blood Neutrophils; Debra L. Laskin; Andrea A. Sirak; Fredika M. Robertson; Jeftrey D. Laskin
Flow cytometry was used to compare intracellular calcium mobilization in mature neutrophilic granulocytes (PMN) with HL-60 promyelocytic leukemia cells induced to differentiate with dibutyryl cyclic adenosine 3’,5’-monophosphate (dbcAMP). Using the calcium-specific probe indo-1 acetoxymethyl ester, we found that the ability of differen-tiating HL-60 cells to mobilize calcium in response to N-formyl-methionyl-leucyl-phen-ylalanine (fMLP) developed concomitantly with expression of receptors on the cells for this peptide. Mobilization of calcium in HL-60 cells, as well as in PMN, in response to fMLP was dose dependent and was related to the presence of calcium in the culture medium. In calcium-free medium, tenfold higher concentrations...

8. Tandem Internal Carotid Artery/Middle Cerebral - José Alvarez-sabín; Carlos A. Molina; Marta Rubiera; Marc Ribo; Raquel Delgado-mederos; Esteban Santamarina; Pilar Delgado
The online version of this article, along with updated information and services, is located on the

9. Creek Experimental Forest, later renamed Sierra Ancha Experimental Forest, for watershed research. - Daniel G. Neary; Gerald J. Gottfried; Peter F. Ffolliott; Leonard F. Debano; Malchus B. Baker; Castle Creek; Thomas Creek; Willow Creek The
Forest watershed research in the Southwest started in Arizona because of concerns about sediment inputs into the newly constructed Roosevelt Reservoir. The Summit Plots were established in 1925 to study the effects of vegetation establishment and mechanical soil stabilization on stormflow and sediment yields.

10. focus of Isfahan Province, Iran - F. Jaffarya; S. H. Hejazia; N. Shareghie; M. Ghaneie; M. Ar; S. H. Moradia
Karyosystematic and morphometric characterization of the rodents as

11. Imaging Moving Targets from Scattered Waves This version includes a Jacobian that is missing in the version published in Inverse Problems 24 (2008) 035005 - Margaret Cheney; Brett Borden
Abstract. We develop a linearized imaging theory that combines the spatial, temporal, and spectral aspects of scattered waves. We consider the case of fixed sensors and a general distribution of objects, each undergoing linear motion; thus the theory deals with imaging distributions in phase space. We derive a model for the data that is appropriate for any waveform, and show how it specializes to familiar results in the cases when: a) the targets are moving slowly, b) the targets are far from the antennas, and c) narrowband waveforms are used. From these models, we develop a phase-space imaging formula that...

12. CONTENT ALERTS - J. S. Maritz; D. A. Mitchison; F. J. Botha; D. P. Parkin; H. I. Seifart; B. W. Van De; P. R. Donald; F. A. Sirgel; T. P. Kanyok; L. H. Danziger; Early Bactericidal; Activity Paromomycin
This article cites 15 articles, 8 of which can be accessed free at:

13. $rec.titulo
Prone position improves expiratory airway mechanics in severe chronic bronchitis S.D. Mentzelopoulos*, C. Roussos # and S.G. Zakynthinos# ABSTRACT: Based on lung parenchyma-airways ’ interdependence, the present authors hypothesised that prone positioning may reduce airway resistance in severe chronic bronchitis. A total of 10 anaesthetised/mechanically ventilated patients were enrolled. Partitioned respiratory system (RS) mechanics during iso-flow experiments (flow50.91 L?s-1, tidal volume (VT) varied within 0.2–1.2 L), haemodynamics, gas-exchange, expiratory airway resistance (Raw,exp), functional residual capacity (FRC), change in FRC (DFRC), end-expiratory lung volume (EELV), expiratory airway resistance at EELV (Raw,exp,EELV), intrinsic positive end-expiratory pressure (PEEPi), and mean end-expiratory flow were...

14. The Therapeutic Benefit of Repeat Percutaneous Vertebroplasty at Previously Treated Vertebral Levels - John R. Gaughen; Mary E. Jensen; Patricia A. Schweickert; William F. Marx; David F. Kallmes
BACKGROUND AND PURPOSE: Recurrent pain after vertebroplasty is relatively common, usually representing a new fracture at a different vertebral level. In a small cohort described herein, clinical and imaging findings indicated that recurrent pain arose from abnormality of the previously treated level. Our purpose was to demonstrate that repeat percutaneous verte-broplasty performed within the same fractured vertebra can offer therapeutic benefit for patients with recurrent pain after initial treatment. METHODS: We conducted a retrospective review of consecutive vertebroplasty procedures performed at our institution to define a patient population that underwent repeat vertebro-plasty for recurrent pain at previously treated vertebral levels....

15. The phonetics of emphasis - Klaus J. Kohler; Oliver Niebuhr
kjk AT; on AT Research is reported in a framework linking pho-netic exponents to communicative functions. From the heterogeneous field of ‘emphasis’, two areas are selected: ‘positive/negative expressive intensi-fication ’ of verbal meaning, e.g. it’s delicious! vs it stinks! German data are collected in controlled monologues and dialogues. On the hypothesis that ‘positive emphasis ’ strengthens sonority, ‘negative emphasis ’ weakens it, aspects of f0, acoustic en-ergy, duration, voice quality are tested statistically. 1.

16. Internal kink mode dynamics in high-beta NSTX plasmas - J. E. Menard; R. E. Bell; E. D. Fredrickson; D. A. Gates; S. M. Kaye; B. P. Leblanc; R. Maingi; S. S. Medley; W. Park; S. A. Sabbagh; A. Sontag; D. Stutman; K. Tritz
Saturated internal kink modes have been observed in many of the highest toroidal β discharges of the National Spherical Torus Experiment (NSTX). These modes often cause rotation flattening in the plasma core, can degrade fast-ion confinement, and in some cases contribute to the complete loss of plasma angular momentum and stored energy. Characteristics of the modes are measured using soft X-ray, kinetic profile, and magnetic diagnostics. Toroidal flows approaching Alfvénic speeds, island pressure peaking, and enhanced viscous and diamagnetic effects associated with high-β may contribute to mode non-linear stabilization. These saturation mechanisms are investigated for NSTX parameters and compared to...

17. Prepared for inclusion in Research in Global Strategic Management, Vol. 13: Regional Aspects of - Vlerick Leuven; Harry P. Bowen; Harry P. Bowen; Vlerick Leuven; Gent Management School; Performance Alan; Rugman Elsevier; Harry P. Bowen
3 The relationship between a firm’s degree of multinationality and its performance is perhaps the most studied relationship in the field of international business. In this paper I address issues concerning the empirical estimation of this relationship. I argue for greater delineation of the underlying nature of firms ’ multinationality and I point to several statistical issues regarding estimation that appear to need resolution, but which appear to have been largely neglected in the international business literature. Among these are endogeneity of the multinationality construct in the performance relationship and the likelihood that the multinationality-performance relationship is heterogeneous across firms.

18. High-Rate Laser Ablation For Through-Wafer Via
Abstract —CO2 laser ablation rates for bulk 4H-SiC substrates and GaN/AlN/SiC templates in the range 229-870 µm.min-1 were obtained for pulse energies of 7.5-30 mJ over diameters of 50-500 µm with a Q-switched pulse width of ~30 nsec and a pulse frequency of 8 Hz. The laser drilling produces much higher etch rates than conventional dry plasma etching (0.2 – 1.3 µm/min) making this an attractive maskless option for creating through-wafer via holes in SiC or GaN/AlN/SiC templates for power metal-semiconductor field effect transistor applications. The via entry can be tapered to facilitate subsequent metallization by control of the laser...

19. Wind Wave Effect on the Sea Surface Measurements - Yuri Trokhimovski
L-band brightness temperature of the sea surface as a function of wind speed was studied only in a few experiments. Such measurements are of high importance for appropriate determining the ocean salinity by microwave radiometers. During Russian experiments at aircraft AN-12 (1981-1989) L-band radiometer was mounted at nadir view angle. Fig. 1 shows an example of the sea surface brightness temperature variation caused by variable wind speed at different wavelengths. All measurements were made at nadir view angle. It is seen, that amplitude registered at L-band is a few times smaller, than amplitude at K- and K-u band. Using similar...

20. Revisiting the Tidal Activation of Seismicity with a Damage Mechanics and Friction Point of View - Stewart W. Smith; Charles G. Sammis
Do Earth tides activate seismicity? Since the peak semi-diurnal tidal stresses are as large as the expected tectonic stress changes over a month’s time, they would easily activate seismicity if it were a simple threshold process. The better question to ask might be, “why don’t we see a very obvious tidal correlation?” Could it be that the rate of tectonic stress accumulation is not uniform, but remains quite low until a rapid increase occurs shortly before the earthquake? Or could it be that a self-driven nucleation process occurs on a time scale longer than the diurnal tide, thus destroying the...

Página de resultados:

Busque un recurso