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Terms modified by Latter Selected AbstractsRenal Adenocarcinoma with Intramyopericardial and Right Atrial Metastasis, Latter via Coronary Sinus: Report of a CaseECHOCARDIOGRAPHY, Issue 4 2005Morteza Rohani M.D. Primary renal tumors with intracardiac metastasis are not infrequent. Most of the secondary spread is blood-borne and occurs via inferior vena cava. Patients with such a spread often present with cardiac symptoms. We presume that a metastatic spread in the right atrium through coronary sinus has never been reported in the literature according to the result of a Medline search at the time of writing this report. [source] Fixed Exchange Rates and Banking Crises: When Does the Former Prevent the Latter?ECONOMIC NOTES, Issue 3 2009Victoria Miller Because monetary policy is constrained in fixed exchange rate regimes, banks should expect fewer money-financed bailouts and therefore manage their risks more carefully when exchange rates are fixed than when they are flexible. It follows that we should observe fewer banking crises in countries with formal currency pegs. The 1990s however are littered with occurrences of banking crises in countries with fixed exchange rates. This paper asks whether banks in those countries could have adopted excess risk expecting money-financed bailouts or whether their pegs discouraged such moral hazard-type risks. [source] Soil organic matter beyond molecular structure Part II: Amorphous nature and physical agingJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2006Gabriele E. Schaumann Abstract Glassy, rubbery, and crystalline phases are representatives of supramolecular structures which strongly differ in order, density, and other characteristics. In this contribution, the amorphous nature of soil organic matter (SOM) is reviewed with respect to the glassy/rubbery model, glass transition mechanisms, interactions of SOM with water, and physical aging. Glass-transition behavior and physical aging are inherent properties of amorphous solids, and numerous spectroscopic investigations give insights into different domain mobilities of humic substances (HS). The correlation between sorption nonlinearity and glassiness of polymers and HS supports a relation between sorption and amorphicity in Aldrich humic acid. Further evidence is still required for the transfer to soil HS and SOM. Sorption and differential scanning calorimetry (DSC) data suggest a correlation between aromaticity and glassiness in HS, and the available data do currently not allow to decide unambiguously between specific sorption and hole filling as explanation. This needs to be verified in future research. Although parts of the investigations have up to now only been conducted with humic substances, the collectivity of available data give strong support for the glassy/rubbery conception of SOM. They clearly indicate that amorphous characteristics cannot be excluded in SOM. This is further supported by the observation of different types of glass-transition behavior in samples of whole humous soil. In addition to classical glass transitions in water-free soil samples, water surprisingly acts in an antagonistic way as short-term plasticizer and long-term antiplasticizer in a second, nonclassical transition type. Latter is closely connected with physico-chemical interactions with water and suggests water bridges between structural elements of SOM (HBCL-model). The gradual increase of Tg* in SOM indicates physico-chemical aging processes, which are not restricted to polymers. They may be responsible for contaminant aging, changes in surface properties and increased soil compaction in agricultural soils. [source] Automatic muscle generation for character skin deformationCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2006Xiaosong Yang Abstract As skin shape depends on the underlying anatomical structure, the anatomy-based techniques usually afford greater realism than the traditional skeleton-driven approach. On the downside, however, it is against the current animation workflow, as the animator has to model many individual muscles before the final skin layer arrives, resulting in an unintuitive modelling process. In this paper, we present a new anatomy-based technique that allows the animator to start from an already modelled character. Muscles having visible influence on the skin shape at the rest pose are extracted automatically by studying the surface geometry of the skin. The extracted muscles are then used to deform the skin in areas where there exist complex deformations. The remaining skin areas, unaffected or hardly affected by the muscles, are handled by the skeleton-driven technique, allowing both techniques to play their strengths. In order for the extracted muscles to produce realistic local skin deformation during animation, muscle bulging and special movements are both represented. Whereas the former ensues volume preservation, the latter allows a muscle not only to deform along a straight path, but also to slide and bend around joints and bones, resulting in the production of sophisticated muscle movements and deformations. Copyright © 2006 John Wiley & Sons, Ltd. [source] Guidelines for treatment of neonatal jaundice.ACTA PAEDIATRICA, Issue 3 2001Is there a place for evidence-based medicine? Treatment of neonatal jaundice continues to be a controversial issue. Arguments that traditional practice results in over-treatment have led to the adoption of more liberal guidelines in some countries. The importation of liberal guidelines from one country to the next, however, is fraught with danger, because differences in epidemiology, sociology and healthcare delivery systems between countries may not be adequately reflected. The unreflected extension of liberalization to non-target groups of patients can expose the latter to significant risk. It is not clear that the evidence on which guidelines for treatment of neonatal jaundice are based satisfy the requirements for evidence-based medicine. Evidence of adequate quality may be hard to obtain. Conclusions: Introduction of more liberal guidelines for the treatment of neonatal jaundice, if at all contemplated, must be adapted to local circumstances, and any available evidence pertaining to local epidemiology, sociology and healthcare organization has to be carefully weighed and incorporated. The time is ripe for a joint international effort to secure adequate funding for basic and applied research within the mechanisms of bilirubin encephalopathy in the newborn. [source] Automatic Light Source Placement for Maximum Visual Information RecoveryCOMPUTER GRAPHICS FORUM, Issue 2 2007P.-P. Vázquez Abstract The automatic selection of good viewing parameters is a very complex problem. In most cases, the notion of good strongly depends on the concrete application. Moreover, when an intuitive definition of good view is available, it is often difficult to establish a measure that brings it to the practice. Commonly, two kinds of viewing parameters must be set: camera parameters (position and orientation) and lighting parameters (number of light sources, its position and eventually the orientation of the spot). The first parameters will determine how much of the geometry can be captured and the latter will influence on how much of it is revealed (i.e., illuminated) to the user. Unfortunately, ensuring that certain parts of a scene are lit does not make sure that the details will be communicated to the user, as the amount of illumination might be too small or too high. In this paper we define a metric to calculate the amount of information relative to an object that is effectively communicated to the user given a fixed camera position. This measure is based on an information-based concept, the Shannon entropy, and will be applied to the problem of automatic selection of light positions in order to adequately illuminate an object. In order to validate the results, we have carried out an experiment on users, this experiment helped us to explore other related measures. [source] Evaluation of Uncertainties Associated with Geocoding TechniquesCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2004Hassan A. Karimi Geocoded data play a major role in numerous engineering applications such as transportation and environmental studies where geospatial information systems (GIS) are used for spatial modeling and analysis as they contain spatial information (e.g., latitude and longitude) about objects. The information that a GIS produces is impacted by the quality of the geocoded data (e.g., coordinates) stored in its database. To make appropriate and reasonable decisions using geocoded data, it is important to understand the sources of uncertainty in geocoding. There are two major sources of uncertainty in geocoding, one related to the database that is used as a reference data set to geocode objects and one related to the interpolation technique used. Factors such as completeness, correctness, consistency, currency, and accuracy of the data in the reference database contribute to the uncertainty of the former whereas the specific logic and assumptions used in an interpolation technique contribute to the latter. The primary purpose of this article is to understand uncertainties associated with interpolation techniques used for geocoding. In doing so, three geocoding algorithms were used and tested and the results were compared with the data collected by the Global Positioning System (GPS). The result of the overall comparison indicated no significant differences between the three algorithms. [source] NMR diffusion measurements under chemical exchange between sites involving a large chemical shift differenceCONCEPTS IN MAGNETIC RESONANCE, Issue 2 2010S. Leclerc Abstract This study concerns the thallium-205 cation in aqueous solution in the presence of a calixarene molecule. Although the measurement of the self-diffusion coefficient of pure thallium (without calixarene in the aqueous solution) does not pose any particular problem, major difficulties are encountered with the standard method using gradient strength increment as soon as thallium is partly complexed by calixarene. With static magnetic field gradients, the NMR signal is so weak that it prevents any reliable measurement, whereas radio frequency (rf) field gradients lead to an unrealistic value of the diffusion coefficient. This failure is explained by the fact that thallium is in fast exchange between two sites (complexed and free thallium) thus exhibiting a single NMR signal although, in the course of the experiment, two signals, with an important difference in resonance frequencies (due to the large thallium chemical shift range), are effectively involved. With the objective to understand these quite unexpected observations, the theory underlying NMR diffusion experiments is first reviewed, and criteria of fast exchange are discussed for three parameters: chemical shifts, relaxation rates, and diffusion coefficients. It turns out that off-resonance effects are responsible for unwanted defocusing due to rf pulses in the static magnetic field gradient method and for time-dependent gradients in the rf field gradient method. Concerning the latter, a remedy is proposed which consists in applying the stronger gradient and incrementing the gradient pulse durations. After correction for relaxation, the expected value of the diffusion coefficient is retrieved. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part A 36A: 127,137, 2010. [source] The origins and present status of the radio wave controversy in NMRCONCEPTS IN MAGNETIC RESONANCE, Issue 4 2009D.I. Hoult Abstract The origins, history, and present status of the controversy surrounding a quantum description of the NMR signal as being due to radio waves are traced. With the Principle of Relativity and Coulomb's Law as formal starting points and the minimum of mathematics needed for understanding, the derivation of a classical electromagnetic theory of signal reception is first given. The agreement between that classical theory and a recent NMR experiment is then presented, leading to proof that, except for the highest field imaging experiments, there is no significant contribution of radio waves to the signal. Attention is drawn to the very different properties of the near and far energy, momenta, and fields inherent in the derivation. The role of the Correspondence Principle in formulating a quantum description is then emphasized and it is shown that the standard NMR interpretation of Dicke's theory of coherent spontaneous emission,that the latter is responsible for the NMR signal,cannot be correct. Finally, the author speculates on some of the intriguing relationships found in the classical electrodynamics of NMR signal reception and attempts to relate them to a common quantum electrodynamic precept of near field interaction: that the free induction decay voltage present at the terminals of an open-circuit receiving coil is based on an exchange of virtual photons between the nuclei in a sample and the free electrons in a receiving coil. © 2009 Crown in the right of Canada. Concepts Magn Reson Part A 34A: 193,216, 2009. [source] Magnetic susceptibility: Further insights into macroscopic and microscopic fields and the sphere of LorentzCONCEPTS IN MAGNETIC RESONANCE, Issue 1 2003C.J. Durrant Abstract To make certain quantitative interpretations of spectra from NMR experiments carried out on heterogeneous samples, such as cells and tissues, we must be able to estimate the magnetic and electric fields experienced by the resonant nuclei of atoms in the sample. Here, we analyze the relationships between these fields and the fields obtained by solving the Maxwell equations that describe the bulk properties of the materials present. This analysis separates the contribution to these fields of the molecule in which the atom in question is bonded, the "host" fields, from the contribution of all the other molecules in the system, the "external" fields. We discuss the circumstances under which the latter can be found by determining the macroscopic fields in the sample and then removing the averaged contribution of the host molecule. We demonstrate that the results produced by the, so-called, "sphere of Lorentz" construction are of general validity in both static and time-varying cases. This analytic construct, however, is not "mystical" and its justification rests not on any sphericity in the system but on the local uniformity and isotropy, i.e., spherical symmetry, of the medium when averaged over random microscopic configurations. This local averaging is precisely that which defines the equations that describe the macroscopic fields. Hence, the external microscopic fields, in a suitably averaged sense, can be estimated from the macroscopic fields. We then discuss the calculation of the external fields and that of the resonant nucleus in NMR experiments. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson Part A 18A: 72,95, 2003 [source] A test suite for parallel performance analysis toolsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11 2007Michael Gerndt Abstract Parallel performance analysis tools must be tested as to whether they perform their task correctly, which comprises at least three aspects. First, it must be ensured that the tools neither alter the semantics nor distort the run-time behavior of the application under investigation. Next, it must be verified that the tools collect the correct performance data as required by their specification. Finally, it must be checked that the tools perform their intended tasks and detect relevant performance problems. Focusing on the latter (correctness) aspect, testing can be done using synthetic test functions with controllable performance properties, possibly complemented by real-world applications with known performance behavior. A systematic test suite can be built from synthetic test functions and other components, possibly with the help of tools to assist the user in putting the pieces together into executable test programs. Clearly, such a test suite can be highly useful to builders of performance analysis tools. It is surprising that, up until now, no systematic effort has been undertaken to provide such a suite. In this paper we describe the APART Test Suite (ATS) for checking the correctness (in the above sense) of parallel performance analysis tools. In particular, we describe a collection of synthetic test functions which allows one to easily construct both simple and more complex test programs with desired performance properties. We briefly report on experience with MPI and OpenMP performance tools when applied to the test cases generated by ATS. Copyright © 2006 John Wiley & Sons, Ltd. [source] Impact of mixed-parallelism on parallel implementations of the Strassen and Winograd matrix multiplication algorithmsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2004F. Desprez Abstract In this paper we study the impact of the simultaneous exploitation of data- and task-parallelism, so called mixed-parallelism, on the Strassen and Winograd matrix multiplication algorithms. This work takes place in the context of Grid computing and, in particular, in the Client,Agent(s),Server(s) model, where data can already be distributed on the platform. For each of those algorithms, we propose two mixed-parallel implementations. The former follows the phases of the original algorithms while the latter has been designed as the result of a list scheduling algorithm. We give a theoretical comparison, in terms of memory usage and execution time, between our algorithms and classical data-parallel implementations. This analysis is corroborated by experiments. Finally, we give some hints about heterogeneous and recursive versions of our algorithms. Copyright © 2004 John Wiley & Sons, Ltd. [source] Loop Diuretic Therapy, Thiamine Balance, and Heart FailureCONGESTIVE HEART FAILURE, Issue 4 2007Domenic A. Sica MD Thiamine, or vitamin B1, is a water-soluble B complex vitamin that was first discovered in 1910 in the process of exploring how rice bran cured patients of beriberi. Thiamine is not synthesized in humans, therefore its availability for necessary cellular processes hinges on its continual ingestion. The amount of thiamine one needs to ingest to maintain balance is disease state-dependent or medication-dependent. Severe chronic thiamine deficiency can have significant neurologic and cardiac effects, the latter is reflected in a particular type of heart failure called wet beriberi. This form of heart failure clearly benefits from thiamine supplementation. It is unclear, however, whether thiamine supplementation offers any benefit in other forms of heart failure. Despite this, it is not unreasonable for heart failure patients to routinely ingest a thiamine-containing multivitamin; patients using diuretics have an increased urinary excretion of thiamine and thus are at a higher risk for developing thiamine deficiency. The role of thiamine in heart failure, however, remains arguable. [source] Management and Recovery Options for Ural River Beluga SturgeonCONSERVATION BIOLOGY, Issue 3 2010PHAEDRA DOUKAKIS caviar; CITES; criadero; Mar Caspio; puntos de referencia; sobrepesca Abstract:,Management of declining fisheries of anadromous species sometimes relies heavily on supplementation of populations with captive breeding, despite evidence that captive breeding can have negative consequences and may not address the root cause of decline. The beluga sturgeon (Huso huso), a species threatened by the market for black caviar and reductions in habitat quality, is managed through harvest control and hatchery supplementation, with an emphasis on the latter. We used yield per recruit and elasticity analyses to evaluate the population status and current levels of fishing and to identify the life-history stages that are the best targets for conservation of beluga of the Ural River. Harvest rates in recent years were four to five times higher than rates that would sustain population abundance. Sustainable rates of fishing mortality are similar to those for other long-lived marine species such as sharks and mammals. Yield per recruit, which is maximized if fish are first harvested at age 31 years, would be greatly enhanced by raising minimum size limits or reducing illegal take of subadults. Improving the survival of subadult and adult females would increase population productivity by 10 times that achieved by improving fecundity and survival from egg to age 1 year (i.e., hatchery supplementation). These results suggest that reducing mortality of subadults and adult wild fish is a more effective conservation strategy than hatchery supplementation. Because genetics is not factored into hatchery management practices, supplementation may even reduce the viability of the beluga sturgeon. Resumen:,El manejo de pesquerías de peces anádromos en declinación a veces depende estrechamente de la suplementación de poblaciones mediante la reproducción en cautiverio, no obstante la evidencia de que la reproducción en cautiverio puede tener consecuencias negativas y no abordar la causa principal de la declinación. El esturión beluga (Huso huso), una especie amenazada por el mercado de caviar negro y por reducciones en la calidad del hábitat, es manejado mediante el control de la cosecha y suplementación de poblaciones, con énfasis en esta. Utilizamos análisis de producción por recluta y de elasticidad para evaluar el estatus de la población y los niveles de pesca actuales y para identificar las etapas de la historia de vida que son los mejores blancos para la conservación del beluga en el Río Ural. Las tasas de cosecha en años recientes fueron cuatro a cinco veces mayores que las tasas que sustentarían la abundancia de la población. Las tasas sustentables de mortalidad por pesca son similares a las de otras especies marinas longevas como tiburones y mamíferos. La producción por recluta, que es maximizada si los peces son cosechados a la edad de 31 años, podría incrementar significativamente elevando los límites de talla mínima o reduciendo la captura ilegal de subadultos. La mejora de la supervivencia de hembras subadultas y adultas incrementaría la productividad de la población 10 veces más que la mejora obtenida incrementando la fecundidad y supervivencia de huevo a 1 año de edad (i. e., suplementación de poblaciones mediante reproducción en cautiverio). Estos resultados sugieren que la reducción de la mortalidad de peces silvestres subadultos y adultos es una mejor estrategia de conservación que la suplementación. Debido a que la genética no es considerada en las prácticas de manejo en los criaderos, la suplementación incluso puede reducir la viabilidad del esturión beluga. [source] A Nationwide Assessment of the Biodiversity Value of Uganda's Important Bird Areas NetworkCONSERVATION BIOLOGY, Issue 1 2006HERBERT TUSHABE AIAs; complementariedad; congruencia trans-taxón; selección de sitios de conservación Abstract:,BirdLife International's Important Bird Areas (IBA) program is the most developed global system for identifying sites of conservation priority. There have been few assessments, however, of the conservation value of IBAs for nonavian taxa. We combined past data with extensive new survey results for Uganda's IBAs in the most comprehensive assessment to date of the wider biodiversity value of a tropical country's IBA network. The combined data set included more than 35,000 site × species records for birds, butterflies, and woody plants at 86 Ugandan sites (23,400 km2), including 29 of the country's 30 IBAs, with data on additional taxa for many sites. Uganda's IBAs contained at least 70% of the country's butterfly and woody plant species, 86% of its dragonflies and 97% of its birds. They also included 21 of Uganda's 22 major vegetation types. For butterflies, dragonflies, and some families of plants assessed, species of high conservation concern were well represented (less so for the latter). The IBAs successfully represented wider biodiversity largely because many have distinctive avifaunas and, as shown by high cross-taxon congruence in complementarity, such sites tended to be distinctive for other groups too. Cross-taxon congruence in overall species richness was weaker and mainly associated with differences in site size. When compared with alternative sets of sites selected using complementarity-based, area-based, or random site-selection algorithms, the IBA network was efficient in terms of the number of sites required to represent species but inefficient in terms of total area. This was mainly because IBA selection considers factors other than area, however, which probably improves both the cost-effectiveness of the network and the persistence of represented species. Resumen:,El programa de Áreas de Importancia para las Aves (AIAs) de Birdlife International es el sistema global más desarrollado para la identificación de sitios de prioridad para la conservación. Sin embargo, ha habido pocas evaluaciones del valor de conservación de las AIAs para taxa no aviares. En la evaluación más integral, hasta la fecha, del valor de la biodiversidad en general de la red de AIAs de un país tropical, combinamos datos antiguos con los resultados de muestreos extensivos recientes de las AIAs de Uganda. El conjunto de datos combinados incluyó más de 35000 registros de sitios x especies de aves, mariposas y plantas leñosas en 86 sitios en Uganda (23400 km2), incluyendo 29 de las 30 AIAs del país, con datos sobre taxa adicionales en muchos sitios. Las AIAs de Uganda contenían por lo menos un 70% de las especies de mariposas y plantas leñosas del país, 86% de sus libélulas y 97% de sus aves. También incluyeron 21 de los 22 principales tipos de vegetación. En las mariposas, libélulas y algunas de las familias de plantas evaluadas, la representación de especies de alto interés para la conservación fue buena (menor en las plantas). Las Áreas de Importancia para las Aves representaron exitosamente a la biodiversidad en general principalmente porque muchas tienen avifaunas distintivas y, como muestra la alta congruencia trans-taxón en complementariedad, tales sitios tendieron a ser distintivos para otros grupos también. La congruencia trans-taxón en la riqueza de especies total fue más débil y se asoció principalmente con diferencias en el tamaño del sitio. Cuando se compara con conjuntos alternativos de sitios seleccionados mediante algoritmos basados en complementariedad, área o selección aleatoria de sitios, la red de AIAs fue eficiente en términos del número de sitios requeridos para representar especies, pero ineficiente en términos del área total. Sin embargo, esto se debió principalmente a que la selección de AIA considera factores distintos al área que probablemente mejoran tanto la efectividad de la red como la persistencia de las especies representadas. [source] Shade-Coffee Plantations as Refuges for Tropical Wild Orchids in Central Veracruz, MexicoCONSERVATION BIOLOGY, Issue 3 2005LISLIE SOLIS-MONTERO biología reproductiva; epifitas vasculares; estratificación vertical; estructura poblacional; limitación de polinizador Abstract:,In central Veracruz, Mexico, coffee plantations have replaced large areas of lower montane cloud forest. Shade-coffee plantations with high levels of structural diversity provide refuge for forest-dependent biota (e.g., birds and insects). Orchids typical of natural forest may also be found in the canopy of shade-coffee agroecosystems. It is not known, however, whether these are relicts from the original forest vegetation or if the plantations themselves provide the necessary conditions to support a self-sustained orchid population. We studied the population structure of the epiphytic orchids Jacquiniella teretifolia (Sw.) Britton & Willson, Scaphyglottis livida (Lindl.) Schltr., and Maxillaria densa Lindl. in a shade-coffee plantation (commercial polyculture) in central Veracruz. We also studied the previously undescribed reproductive biology of the latter two species. Our results show that the three orchid species had high population densities (>800 plants/ha). In our study site, 50% to 68% of the orchid plants of the target species were young individuals (less than five shoots). Reproductive structures were present in 80% of individuals larger than 30 shoots in the three species. M. densa is self-incompatible, and the fruit set obtained from cross pollination (42.7%) was higher than that obtained from natural pollination (18.2%), suggesting that this species could be pollinator limited. S. livida is autocompatible, not autogamous, and was not pollinator limited. Our results show that the coffee plantation had abundant orchid populations with log-normal size/age structures. Two of the target species, M. densa and S. livida, depend on pollinators to reproduce. It is clear that pollinators that allow orchids to set a high proportion of fruits persist in shade-coffee plantations. Coffee plantations may not replace the original conditions of a forest, but it is possible that these and other orchid species survive and reproduce in coffee plantations that provide appropriate microclimate conditions for the plants, including pollinators. Resumen:,En el centro de Veracruz, México, las plantaciones de café han reemplazado a extensas áreas de bosque nublado montano. Las plantaciones cafetaleras de sombra con altos niveles de diversidad estructural proporcionan refugio a biota dependiente de bosques (e. g., aves e insectos). En el dosel de agroecosistemas de café de sombra también se pueden encontrar orquídeas típicas de bosques naturales. Sin embargo, no se conoce si son relictos de la vegetación del bosque original o si las plantaciones mismas proporcionan los recursos necesarios para soportar a una población de orquídeas auto sostenida. Estudiamos la estructura de la población de orquídeas epifitas Jacquiniella teretifolia (Sw.) Britton & Willson, Scaphyglottis livida (Lindl.) Schltr y Maxillaria densa Lindl en una plantación de café de sombra (policultivo comercial) en el centro de Veracruz. También estudiamos la biología reproductiva, no descrita previamente, de las últimas dos especies. Nuestros resultados muestran que las tres especies de orquídea tuvieron densidades poblacionales altas (>800 plantas/ha). En nuestro sitio de estudio, entre 50% y 68% de las plantas de las especies estudiadas eran individuos jóvenes (menos de cinco rebrotes). En las tres especies hubo presencia de estructuras reproductivas en 80% de los individuos con más de 30 rebrotes. M. densa es auto incompatible, y el conjunto de frutos obtenido por polinización cruzada (42.7%) fue mayor que el obtenido por polinización natural (18.2%), lo que sugiere que esta especie puede estar limitada por polinizadores. S. livida es autocompatible no autogama, y no fue limitada por polinizadores. Nuestros resultados muestran que la plantación de café tenía poblaciones de orquídeas abundantes con estructuras tamaño/edad log normales. Dos de las especies, M. densa y S. livida, dependen de polinizadores para su reproducción. Es claro que los polinizadores que permiten una alta proporción de frutos a las orquídeas persisten en las plantaciones. Puede que las plantaciones de café no sustituyan las condiciones originales de un bosque, pero es posible que estas, y otras, especies de orquídeas sobrevivan y se reproduzcan en plantaciones de café que proporcionen condiciones microclimáticas adecuadas, incluyendo polinizadores, para las plantas. [source] Orexins and the regulation of the hypothalamic-pituitary-testicular axisACTA PHYSIOLOGICA, Issue 3 2010M. Nurmio Abstract Orexins (OX), OX-A and OX-B, were initially identified as hypothalamic neuropeptides primarily involved in the control of food intake and states of arousal. Thereafter, orexins have been substantiated as putative pleiotropic regulators of a wide diversity of biological systems, including different neuroendocrine axes. Among the latter, compelling experimental evidence has recently been documented that orexins, mainly OX-A, may act at different levels of the hypothalamic-pituitary-gonadal (HPG) axis to modulate reproductive function. These actions are likely to include regulatory effects on the hypothalamic centres governing the HPG axis, as well as direct actions at the gonadal level. We review herein the experimental evidence, gathered in recent years, supporting a reproductive ,facet' of orexins, with special emphasis on our current knowledge of their patterns of expression and potential functional roles in the testis. Overall, the available data strongly suggest that, by acting at different levels of the HPG axis, orexins may operate as putative neuroendocrine and autocrine/paracrine regulators of gonadal function. [source] Investigation of the Start Transient in a Hall ThrusterCONTRIBUTIONS TO PLASMA PHYSICS, Issue 9-10 2008H. Liu Abstract A two dimensional axisymmetric fully kinetic Particle-in-Cell/Monte Carlo Collision (PIC-MCC) model is used to describe the ignition process in a Hall thruster. A current peak and latter the periodic oscillation of current and electric potential are found. The corresponding evolutions of plasma density, electric potential and atom density during the ignition process are introduced in the paper. In addition, influences of mass flow rate and discharge potential on current peak are modeled and analyzed. The simulated results are consistent with former experimental results. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Similarity of permeabilities for Ficoll, pullulan, charge-modified albumin and native albumin across the rat peritoneal membraneACTA PHYSIOLOGICA, Issue 4 2009D. Asgeirsson Abstract Aim:, Compared to neutral globular proteins, neutral polysaccharides, such as dextran, pullulan and Ficoll, appear hyperpermeable across the glomerular filtration barrier. This has been attributed to an increased flexibility and/or asymmetry of polysaccharides. The present study investigates whether polysaccharides are hyperpermeable also across the continuous capillaries in the rat peritoneum. Methods:, In anaesthetized Wistar rats, FITC,Ficoll or FITC,pullulan together with 125I-human serum albumin (RISA) or neutralized 125I-bovine serum albumin (nBSA) were given intravenously, after which peritoneal dialysis (PD) using conventional PD fluid (Gambrosol 1.5%) was performed for 120 min. Concentrations of FITC-polysaccharides and radioactive albumin species in plasma and dialysis fluid were analysed with high-performance size exclusion chromatography and a gamma counter respectively. Transperitoneal clearance values were calculated for polysaccharides in the molecular radius range 36,150 Å, and for RISA and nBSA. Results:, Ficoll and pullulan showed more or less identical permeabilities, compared to RISA and nBSA, across the peritoneal membrane. Although RISA-clearance, 5.50 ± 0.28 (,L min,1; ±SEM), tended to be lower than the clearances of Ficoll36Å (6.55 ± 0.25), pullulan36Å (6.08 ± 0.22) and nBSA (6.56 ± 0.23), the difference was not statistically significant. This is in contrast to the hyperpermeability exhibited by polysaccharides across the glomerular filtration barrier and also contrasts with the charge selectivity of the latter. Conclusion:, The phenomenon of molecular flexibility is more important for a macromolecule's permeability through the glomerular filter than across the continuous peritoneal capillary endothelium. Furthermore, it seems that charge plays a subordinate role in the steady-state transport across the combined peritoneal capillary,interstitial barrier. [source] Impaired oxygen kinetics in beta-thalassaemia major patientsACTA PHYSIOLOGICA, Issue 3 2009I. Vasileiadis Abstract Aim:, Beta-thalassaemia major (TM) affects oxygen flow and utilization and reduces patients' exercise capacity. The aim of this study was to assess phase I and phase II oxygen kinetics during submaximal exercise test in thalassaemics and make possible considerations about the pathophysiology of the energy-producing mechanisms and their expected exercise limitation. Methods:, Twelve TM patients with no clinical evidence of cardiac or respiratory disease and 10 healthy subjects performed incremental, symptom-limited cardiopulmonary exercise testing (CPET) and submaximal, constant workload CPET. Oxygen uptake (Vo2), carbon dioxide output and ventilation were measured breath-by-breath. Results:, Peak Vo2 was reduced in TM patients (22.3 ± 7.4 vs. 28.8 ± 4.8 mL kg,1 min,1, P < 0.05) as was anaerobic threshold (13.1 ± 2.7 vs. 17.4 ± 2.6 mL kg,1 min,1, P = 0.002). There was no difference in oxygen cost of work at peak exercise (11.7 ± 1.9 vs. 12.6 ± 1.9 mL min,1 W,1 for patients and controls respectively, P = ns). Phase I duration was similar in TM patients and controls (24.6 ± 7.3 vs. 23.3 ± 6.6 s respectively, P = ns) whereas phase II time constant in patients was significantly prolonged (42.8 ± 12.0 vs. 32.0 ± 9.8 s, P < 0.05). Conclusion:, TM patients present prolonged phase II on-transient oxygen kinetics during submaximal, constant workload exercise, compared with healthy controls, possibly suggesting a slower rate of high energy phosphate production and utilization and reduced oxidative capacity of myocytes; the latter could also account for their significantly limited exercise tolerance. [source] Oversight and Delegation in Corporate Governance: deciding what the board should decideCORPORATE GOVERNANCE, Issue 1 2006Michael Useem American boards of directors increasingly treat their delegation of authority to management as a careful and self-conscious decision. Numerically dominated by non-executives, boards recognize that they cannot run the company, and many are now seeking to provide stronger oversight of the company without crossing the line into management. Based on interviews with informants at 31 major companies, we find that annual calendars and written protocols are often used to allocate decision rights between the board and management. Written protocols vary widely, ranging from detailed and comprehensive to skeletal and limited in scope. While useful, such calendars and protocols do not negate the need for executives to make frequent judgement calls on what issues should go to the board and what should remain within management. Executives still set much of the board's decision-making agenda, and despite increasingly asserting their sovereignty in recent years, directors remain substantially dependent upon the executives' judgement on what should come to the board. At the same time, a norm is emerging among directors and executives that the latter must be mindful of what directors want to hear and believe they should decide. [source] Behaviour problems in childhood and adolescence in psychotic offenders: an exploratory studyCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 3 2008Kris Goethals Background,Several studies have shown that adults who develop schizophrenia and commit a criminal offence may already have shown behaviour problems in childhood or adolescence. It is less clear whether such problems follow a particular pattern in such patients. Aims,To examine the utility of the Child Behavior Checklist (CBCL) among offenders, to test whether externalizing behaviour problems, as measured by the CBCL, are more frequent in psychotic offenders than in non-offenders with psychosis, and to investigate relationships between early behavioural problems and adult personality disorder in psychotic offenders. Methods,Three groups of violent offenders detained under the Dutch Entrustment Act (TBS-detainees)(n = 78) and one group of psychotic patients in general psychiatry (n = 16) were rated from case records on the CBCL. Results,There was a significant difference between psychotic offenders with a personality disorder (n = 25) and the non-offender patients with psychosis (n = 16) on the ,delinquent behavior' scale, but no such difference between psychotic offenders with (n = 25) and without (n = 21) personality disorder. A hierarchic cluster analysis revealed significantly higher scores for externalizing behaviour in all TBS-detainees with a personality disorder. Those starting to offend early had higher scores for externalizing behaviour than late starters. Conclusions,Psychotic and non-psychotic offenders with personality disorder resemble one another in their early childhood behaviour problems; psychotic offenders without a personality disorder differ from these two groups but resemble non-offenders with psychosis. In contrast to findings in non-forensic populations, there were no differences on other problem scales of the CBCL. Given the small sample sizes, replication is needed, but the findings lend weight to treatment models which focus on the psychosis in the latter two groups but extend also to personality disorder in the former. Copyright © 2008 John Wiley & Sons, Ltd. [source] An exploration of research into substance misuse and psychiatric disorder in the UK: what can we learn from history?CRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 4 2007Ilana B. Crome Background and aim,This review explores UK-based research developments in substance misuse and mental illness over the last 25 years. The main body of work comprises policy-orientated projects funded by the Department of Health from the late 1990s. Early research tended to focus on alcohol, especially alcoholic hallucinosis: the relationship of the latter with schizophrenia-like illness was examined, with the finding that very few cases did develop into schizophrenia. Method and implications,Parallels are drawn with the current debate around the link between cannabis and psychosis, urging caution in too rapid an assertion that cannabis is necessarily ,causal'. The clinical and policy implications of the misinterpretation of evidence are discussed. A proposal is put forward that the genesis of psychotic illness in alcohol misuse be revisited using more sophisticated research methodologies. Given the changing landscape of substance use in the UK, particularly the fashion of polysubstance use and the recognition that this is associated with psychotic illness, other drugs that are associated with psychotic illness should be similarly investigated to determine whether there is a common mechanism that might throw light on understanding the relationship between substance use and psychotic illness or schizophrenia. Copyright © 2007 John Wiley & Sons, Ltd. [source] Does personality change and, if so, what changes?,CRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 1 2004Conor Duggan Background Although the question of whether or not personality changes is fundamental to much of what clinicians do, we do not appear to be very curious about the question itself. Method This paper considers three separate but related issues: (a) Does personality change? (b) If it does, then what changes? (c) How can we show that change has taken place? Costa and McCrea have produced a model of personality that helps to answer (a) and (b), as it distinguishes ,Basic Tendencies' from ,Characteristic Adaptations'. The former are largely innate, fixed dispositions that produce the latter (which are highly variable) depending on its interaction with differing environments. Thus, personality is both static and dynamic depending on its definition. It will also be argued that detecting change is complex as there are many alternative definitions of the relevant outcome variable. Moreover, measuring several different outcomes does not help as change in one measure is often not matched by a concordant change in another. Some practical examples are provided to support this position. Conclusions In the absence of a firm theoretical base, the author believes that only limited conclusions can be drawn about the efficacy of treatment in personality disorder. Copyright © 2004 Whurr Publishers Ltd. [source] ESTIMATING A DOSE-RESPONSE RELATIONSHIP BETWEEN LENGTH OF STAY AND FUTURE RECIDIVISM IN SERIOUS JUVENILE OFFENDERS,CRIMINOLOGY, Issue 3 2009THOMAS A. LOUGHRAN The effect of sanctions on subsequent criminal activity is of central theoretical importance in criminology. A key question for juvenile justice policy is the degree to which serious juvenile offenders respond to sanctions and/or treatment administered by the juvenile court. The policy question germane to this debate is finding the level of confinement within the juvenile justice system that maximizes the public safety and therapeutic benefits of institutional confinement. Unfortunately, research on this issue has been limited with regard to serious juvenile offenders. We use longitudinal data from a large sample of serious juvenile offenders from two large cities to 1) estimate a causal treatment effect of institutional placement, as opposed to probation, on future rate of rearrest and 2) investigate the existence of a marginal effect (i.e., benefit) for longer length of stay once the institutional placement decision had been made. We accomplish the latter by determining a dose-response relationship between the length of stay and future rates of rearrest and self-reported offending. The results suggest that an overall null effect of placement exists on future rates of rearrest or self-reported offending for serious juvenile offenders. We also find that, for the group placed out of the community, it is apparent that little or no marginal benefit exists for longer lengths of stay. Theoretical, empirical, and policy issues are outlined. [source] THE INTERACTION OF ANTISOCIAL PROPENSITY AND LIFE-COURSE VARYING PREDICTORS OF DELINQUENT BEHAVIOR: DIFFERENCES BY METHOD OF ESTIMATION AND IMPLICATIONS FOR THEORY,CRIMINOLOGY, Issue 2 2007GRAHAM C. OUSEY Recent criminological research has explored the extent to which stable propensity and life-course perspectives may be integrated to provide a more comprehensive explanation of variation in individual criminal offending. One line of these integrative efforts focuses on the ways that stable individual characteristics may interact with, or modify, the effects of life-course varying social factors. Given their consistency with the long-standing view that person,environment interactions contribute to variation in human social behavior, these theoretical integration attempts have great intuitive appeal. However, a review of past criminological research suggests that conceptual and empirical complexities have, so far, somewhat dampened the development of a coherent theoretical understanding of the nature of interaction effects between stable individual antisocial propensity and time-varying social variables. In this study, we outline and empirically assess several of the sometimes conflicting hypotheses regarding the ways that antisocial propensity moderates the influence of time-varying social factors on delinquent offending. Unlike some prior studies, however, we explicitly measure the interactive effects of stable antisocial propensity and time-varying measures of selected social variables on changes in delinquent offending. In addition, drawing on recent research that suggests that the relative ubiquity of interaction effects in past studies may be partly from the poorly suited application of linear statistical models to delinquency data, we alternatively test our interaction hypotheses using least-squares and tobit estimation frameworks. Our findings suggest that method of estimation matters, with interaction effects appearing readily in the former but not in the latter. The implications of these findings for future conceptual and empirical work on stable propensity/time-varying social variable interaction effects are discussed. [source] When is high-Ca2+ microdomain required for mitochondrial Ca2+ uptake?,ACTA PHYSIOLOGICA, Issue 1 2009A. Spät Abstract Ca2+ release from IP3 -sensitive stores in the endoplasmic reticulum (ER) induced by Ca2+ -mobilizing agonists generates high-Ca2+ microdomains between ER vesicles and neighbouring mitochondria. Here we present a model that describes when such microdomains are required and when submicromolar [Ca2+] is sufficient for mitochondrial Ca2+ uptake. Mitochondrial Ca2+ uptake rate in angiotensin II-stimulated H295R adrenocortical cells correlates with the proximity between ER vesicles and the mitochondrion, reflecting the uptake promoting effect of high-Ca2+ peri-mitochondrial microdomains. Silencing or inhibition of p38 mitogen-activated protein kinase (MAPK) or inhibition of the novel isoforms of protein kinase C enhances mitochondrial Ca2+ uptake and abolishes the positive correlation between Ca2+ uptake and ER-mitochondrion proximity. Inhibition of protein phosphatases attenuates mitochondrial Ca2+ uptake and also abolishes its positive correlation with ER-mitochondrion proximity. We postulate that during IP3 -induced Ca2+ release, Ca2+ uptake is confined to ER-close mitochondria, because of the simultaneous activation of the protein kinases. Attenuation of Ca2+ uptake prevents Ca2+ overload of mitochondria and thus protects the cell against apoptosis. On the other hand, all the mitochondria accumulate Ca2+ at a non-inhibited rate during physiological Ca2+ influx through the plasma membrane. Membrane potential is higher in ER-distant mitochondria, providing a bigger driving force for Ca2+ uptake. Our model explains why comparable mitochondrial Ca2+ signals are formed in response to K+ and angiotensin II (equipotent in respect to global cytosolic Ca2+ signals), although only the latter generates high-Ca2+ microdomains. [source] The Art and Science of Surge: Experience from Israel and the U.S. MilitaryACADEMIC EMERGENCY MEDICINE, Issue 11 2006Boaz Tadmor MD In a disaster or mass casualty incident, health care resources may be exceeded and systems may be challenged by unusual requirements. These resources may include pharmaceuticals, supplies, and equipment as well as certain types of academic and administrative expertise. New agencies and decision makers may need to work together in an unfamiliar environment. Furthermore, large numbers of casualties needing treatment, newer therapies required to care for these casualties, and increased workforce and space available for these casualties all contribute to what is often referred to as "surge." Surge capacity in emergency care can be described in technical, scientific terms that are measured by numbers and benchmarks (e.g., beds, patients, and medications) or can take on a more conceptual and abstract form (e.g., decisions, authority, and responsibility). The former may be referred to as the "science" of surge, whereas the latter, an equal if not more important component of surge systems that is more conceptual and abstract, can be considered the "art" of surge. The experiences from Israel and the U.S. military may serve to educate colleagues who may be required to respond or react to an event that taxes the current health care system. This report presents concrete examples of surge capacity strategies used by both Israel and the U.S. military and provides solutions that may be applied to other health care systems when faced with similar situations. [source] The use of p63 as an effective immunomarker in the diagnosis of pulmonary squamous cell carcinomas on de-stained bronchial lavage cytological smearsCYTOPATHOLOGY, Issue 1 2010M. Uke M. Uke, B. Rekhi, D. Ajit and N. A. Jambhekar The use of p63 as an effective immunomarker in the diagnosis of pulmonary squamous cell carcinomas on de-stained bronchial lavage cytological smears Objectives:, A diagnosis in pulmonary onco-cytopathology primarily necessitates distinguishing small cell carcinoma (SCLC) from non-small cell carcinoma (NSCLC), which includes squamous cell carcinoma and adenocarcinoma. Lately, p63 antibody has been used for distinguishing squamous cell carcinoma from SCLC and adenocarcinoma. We present an analysis of p63 expression in cytological smears from 100 bronchial lavage specimens comprising 51 cases of SCLC and 49 cases of NSCLC. Methods:, A single Papanicolaou-stained conventional smear was de-stained and re-fixed with cold acetone and methanol for immunocytochemical staining with p63 antibody. Staining results were graded as 0 (nil), 1+ (focal), 2+ (moderate, diffuse) and 3+ (strong, diffuse). Results:, Out of 100 cases, 21 were cytologically diagnosed as squamous cell carcinoma. Twenty of these showed 2+ or 3+ p63 positivity, whereas one, which was adenocarcinoma on histology, showed 1+ staining. Of seven cases cytologically diagnosed as adenocarcinoma, six showed no p63 staining, whereas one, which was squamous cell carcinoma on histology, showed 1+ staining. All 48 cases cytologically diagnosed as SCLC were confirmed as such on histology and showed no p63 staining. Four cases were cytologically designated as poorly differentiated carcinomas, of which three showed no p63 staining and one showed 3+ staining. The former three were found to be SCLC on histology while the latter was squamous cell carcinoma. The remaining 20 cases were cytologically designated as NSCLC. Of these, eight showed no p63 staining, whereas 10 showed 1+ and two showed 2+ staining. The former eight were adenocarcinoma on histology and the latter two were squamous cell carcinoma. The 10 cases that showed 1+ p63 staining were adenocarcinomas (n = 5), squamous cell carcinoma (n = 4) and NSCLC, not otherwise specified (n = 1). Positive staining was seen in normal basal cells, which acted as an internal control. Overall sensitivity of p63 for squamous cell carcinoma was 100% and specificity was 90.4%. Conclusions:, p63 immunostaining on processed cytology smears can be used to help identify squamous cell carcinoma. Its diffuse expression was specific for squamous cell carcinoma while focal staining was also seen in adenocarcinoma. [source] Langerhans cell histiocytosis in lymph nodes , cytomorphological diagnosis and pitfallsCYTOPATHOLOGY, Issue 6 2000S. Kakkar Background Langerhans cell histiocytosis (LCH) is a rare disorder of unknown aetiology that may present as a multisystem or unisystem disease. The Lymph nodes can be involved as part of disseminated disease, as a metastatic site draining a focus of LCH or may be a unisystem involvement. Paucity of literature on the cytomorphology of LCH in lymph nodes led us to undertake this study. Materials and methods Nine cases with a confirmed histological diagnosis of LCH and a prior lymph node aspirate were retrieved over a 12 year period (1988,1999). Five more cases were reviewed where the cytological diagnosis of LCH was rendered on a background of clinical and radiological findings. Papanicolaou and May Grunwald,Giemsa-stained smears were examined. S-100 protein staining was available in four cases. Results and conclusions Nine cases had multisystem involvement, while in five cases only lymph nodes were involved. There were eleven males and three females; age ranged from five months to 27 years. The cytological diagnosis of LCH had been rendered in six, suspected in four and missed in four. Of the latter, two were reclassified as LCH on review, one as reactive lymphadenitis and in one a necrotising lesion was suspected. The pathognomonic ,LCH cell' was identified in 12 of 14 cases along with varying numbers of eosinophils, polymorphs and lymphocytes. Giant cells were seen in only six cases. In conclusion lymph node involvement by LCH can be identified on aspirates. However, LCH must be differentiated from dermatopathic lymphadenitis, sinus histiocytosis with massive lymphadenopathy and Hodgkin's disease. 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