928 resultados para SIZE-RAMSEY NUMBER
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Nitric oxide (NO) mediates a variety of physiological functions in the central nervous system and acts as an important developmental regulator. Striatal interneurons expressing neuronal nitric oxide synthase (nNOS) have been described to be relatively spared from the progressive cell loss in Huntington's disease (HD). We have recently shown that creatine, which supports the phosphagen energy system, induces the differentiation of GABAergic cells in cultured striatal tissue. Moreover, neurotrophin-4/5 (NT-4/5) has been found to promote the survival and differentiation of cultured striatal neurons. In the present study, we assessed the effects of creatine and NT-4/5 on nNOS-immunoreactive (-ir) neurons of E14 rat ganglionic eminences grown for 1 week in culture. Chronic administration of creatine [5mM], NT-4/5 [10ng/ml], or a combination of both factors significantly increased numbers of nNOS-ir neurons. NT-4/5 exposure also robustly increased levels of nNOS protein. Interestingly, only NT-4/5 and combined treatment significantly increased general viability but no effects were seen for creatine supplementation alone. In addition, NT-4/5 and combined treatment resulted in a significant larger soma size and number of primary neurites of nNOS-ir neurons while creatine administration alone exerted no effects. Double-immunolabeling studies revealed that all nNOS-ir cells co-localized with GABA. In summary, our findings suggest that creatine and NT-4/5 affect differentiation and/or survival of striatal nNOS-ir GABAergic interneurons. These findings provide novel insights into the biology of developing striatal neurons and highlight the potential of both creatine and NT-4/5 as therapeutics for HD.
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OBJECTIVES: To determine sample sizes in studies on diagnostic accuracy and the proportion of studies that report calculations of sample size. DESIGN: Literature survey. DATA SOURCES: All issues of eight leading journals published in 2002. METHODS: Sample sizes, number of subgroup analyses, and how often studies reported calculations of sample size were extracted. RESULTS: 43 of 8999 articles were non-screening studies on diagnostic accuracy. The median sample size was 118 (interquartile range 71-350) and the median prevalence of the target condition was 43% (27-61%). The median number of patients with the target condition--needed to calculate a test's sensitivity--was 49 (28-91). The median number of patients without the target condition--needed to determine a test's specificity--was 76 (27-209). Two of the 43 studies (5%) reported a priori calculations of sample size. Twenty articles (47%) reported results for patient subgroups. The number of subgroups ranged from two to 19 (median four). No studies reported that sample size was calculated on the basis of preplanned analyses of subgroups. CONCLUSION: Few studies on diagnostic accuracy report considerations of sample size. The number of participants in most studies on diagnostic accuracy is probably too small to analyse variability of measures of accuracy across patient subgroups.
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Satellite measurement validations, climate models, atmospheric radiative transfer models and cloud models, all depend on accurate measurements of cloud particle size distributions, number densities, spatial distributions, and other parameters relevant to cloud microphysical processes. And many airborne instruments designed to measure size distributions and concentrations of cloud particles have large uncertainties in measuring number densities and size distributions of small ice crystals. HOLODEC (Holographic Detector for Clouds) is a new instrument that does not have many of these uncertainties and makes possible measurements that other probes have never made. The advantages of HOLODEC are inherent to the holographic method. In this dissertation, I describe HOLODEC, its in-situ measurements of cloud particles, and the results of its test flights. I present a hologram reconstruction algorithm that has a sample spacing that does not vary with reconstruction distance. This reconstruction algorithm accurately reconstructs the field to all distances inside a typical holographic measurement volume as proven by comparison with analytical solutions to the Huygens-Fresnel diffraction integral. It is fast to compute, and has diffraction limited resolution. Further, described herein is an algorithm that can find the position along the optical axis of small particles as well as large complex-shaped particles. I explain an implementation of these algorithms that is an efficient, robust, automated program that allows us to process holograms on a computer cluster in a reasonable time. I show size distributions and number densities of cloud particles, and show that they are within the uncertainty of independent measurements made with another measurement method. The feasibility of another cloud particle instrument that has advantages over new standard instruments is proven. These advantages include a unique ability to detect shattered particles using three-dimensional positions, and a sample volume size that does not vary with particle size or airspeed. It also is able to yield two-dimensional particle profiles using the same measurements.
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The ectoparasitic mite Varroa destructor acting as a virus vector constitutes a central mechanism for losses of managed honey bee, Apis mellifera, colonies. This creates demand for an easy, accurate and cheap diagnostic tool to estimate the impact of viruliferous mites in the field. Here we evaluated whether the clinical signs of the ubiquitous and mite-transmitted deformed wing virus (DWV) can be predictive markers of winter losses. In fall and winter 2007/2008, A.m. carnica workers with apparent wing deformities were counted daily in traps installed on 29 queenright colonies. The data show that colonies which later died had a significantly higher proportion of workers with wing deformities than did those which survived. There was a significant positive correlation between V. destructor infestation levels and the number of workers displaying DWV clinical signs, further supporting the mite's impact on virus infections at the colony level. A logistic regression model suggests that colony size, the number of workers with wing deformities and V. destructor infestation levels constitute predictive markers for winter colony losses in this order of importance and ease of evaluation.
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Background: Bernese mountain dogs are reported to have a shorter life expectancy than other breeds. A Major reason for this has been assigned to a high tumour prevalence, especially of histiocytic sarcoma. The efforts made by the breeding clubs to improve the longevity with the help of genetic tests and breeding value estimations are impeded by insufficiently reliable diagnoses regarding the cause of death. The current standard for post mortem examination in animals is performance of an autopsy. In human forensic medicine, imaging modalities, such as computed tomography and magnetic resonance imaging, are used with increasing frequency as a complement to autopsy. The present study investigates, whether post mortem computed tomography in combination with core needle biopsy is able to provide a definitive diagnosis of histiocytic sarcoma. For this purpose we have analysed the results of post mortem computed tomography and core needle biopsy in eleven Bernese mountain dogs. In the subsequent autopsy, every dog had a definitive diagnosis of histiocytic sarcoma, based on immunohistochemistry. Results: Computed tomography revealed space-occupying lesions in all dogs. Lesion detection by post mortem computed tomography was similar to lesion detection in autopsy for lung tissue (9 cases in computed tomography / 8 cases in autopsy), thoracic lymph nodes (9/8), spleen (6/7), kidney (2/2) and bone (3/3). Hepatic nodules, however, were difficult to detect with our scanning protocol (2/7). Histology of the core needle biopsies provided definitive diagnoses of histiocytic sarcoma in ten dogs, including confirmation by immunohistochemistry in six dogs. The biopsy samples of the remaining dog did not contain any identifiable neoplastic cells. Autolysis was the main reason for uncertain histological diagnoses. Conclusions: Post mortem computed tomography is a fast and effective method for the detection of lesions suspicious for histiocytic sarcoma in pulmonary, thoracic lymphatic, splenic, osseous and renal tissue. Optimization of the procedure regarding the scanning protocol and tissue sample size and number will improve the accuracy of the method. Keywords: Post mortem computed tomography, Core needle biopsy, Bernese mountain dog, Histiocytic sarcoma, Autopsy
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Luego de un período de desmantelamiento de la estructura productiva nacional desde fines de 2002 la economía argentina comenzó lentamente a recuperarse, con una incipiente revitalización de la industria. En este escenario, el trabajo describe el perfil y las características de la estructura industrial de la provincia de Mendoza con el fin de trazar el punto de partida para el potencial desarrollo económico local, en relación con la distribución geográfica de las unidades productivas, los sectores más dinámicos y su concentración, diferenciando a aquellas según tamaño definido por cantidad de ocupados. Los datos analizados provienen del Censo Industrial Provincial, 2002/2003.
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Soft-sediment deformation structures have been analyzed at six sites of the Kathmandu valley. Microgranulometric study (this Supplement and Fig. 3B of Mugnier et al., Tectonophysics, 2011) reveals that silty levels (60 to 80% silt) favor the development of soft-sediment deformation structures, while sandy levels (60 to 80% sand) are passively deformed. Nonetheless well sorted sand levels (more than 80% sand) generate over-fluid pressure during compaction if located beneath a silty cap, leading to fluidization and dike development. 3-D geometry of seismites indicates a very strong horizontal shearing during their development. Using a physical approach based on soil liquefaction during horizontal acceleration, we show that the fluidization zone progressively grows down-section during the shaking, but does not exactly begin at the surface. The comparison of bed-thickness and strength/depth evolution indicates three cases: i) no soft-sediment deformation occurs for thin (few centimeters) silty beds; ii) the thickness of soft-sediment deformation above sandy beds is controlled by the lithological contrast; iii) the thickness of soft-sediment deformation depends on the shaking intensity for very thick silty beds. These 3 cases are evidenced in the Kathmandu basin. We use the 30 cm-thick soft-sediment deformation level formed during the 1833 earthquake as a reference: the 1833 earthquake rupture zone extended very close to Kathmandu, inducing there MMI IX-X damages. A 90 cm-thick sediment deformation has therefore to be induced by an event greater than MMI X. From a compilation of paleo and historic seismology studies, it is found that the great (M ~ 8.1) historical earthquakes are not characteristic of the greatest earthquakes of Himalaya; hence earthquakes greater than M ~ 8.6 occurred. Kathmandu is located above one of the asperities that laterally limits the extent of mega-earthquake ruptures and two successive catastrophic events already affected Kathmandu, in 1255 located to the west of this asperity and in ~ 1100 to the east.
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At the NW-slope of Eckernforder Bay (Western Baltic) between 14 and 21 m water depth 7 sand cores were taken with a vibrocorer. The cores were between 85 and 250 cm long. The sand was analysed for grain size distribution, proportions of organic carbon and carbonate, and contents of microfossils. The radiometric age and stable carbon isotope ratios were determined on organic material from 14 sample. With regard to benthic foraminifera and other microorganisms four different types of depositional conditions could be distinguished: Types 1 and 2: two types of offshore sand areas. Type 3: lagoon and nearshore. Type 4: subaerial or limnic. Using sedimentological and geochemical parameters two formation areas could be distinguished with the aid of a discriminant analysis: offshore (types 1 and 2) and nearshore (types 3 and 4). A juxtaposition of core sections indicated two distinct profiles. Their ages fit into the picture of the assumed postglacial sea-level rise. The lagoon- and nearshore sands are interpreted as the result of sea-level stagnation at 17-18 m below present sea-level. The accumulation rates of the sand in the offshore areas are, with a maximum of 0.15 mm/yr., an order of magnitude smaller than in the mud areas, located several hundred metres away.
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Twenty-one narwhals tagged in 2003 and 2004 in Admiralty Inlet showed a different summer distributional pattern than previous narwhal-tracking studies from Somerset Island, Eclipse Sound and Melville Bay. The migration of the narwhals tracked from Admiralty Inlet moved out through Lancaster Sound 15 days earlier (P <0.0001) than the narwhals summering around Eclipse Sound, whereas the Admiralty Inlet narwhals reached the mouths of Eclipse Sound 18 days later (P <0.0001) than the Eclipse Sound summering population. The winter range of the Admiralty Inlet narwhals overlapped with the winter range of narwhals from Melville Bay and Eclipse Sound in central southern Baffin Bay and Northern Davis Strait, but not with the winter range of narwhals from Somerset Island that wintered further north. Distribution size of range, and population size did not appear to be related. An example of considerable year to year variation between area of summer and winter distribution in the 2 years was believed to be related to the sample size and number of pods of whales tagged, rather than to differences in sex or age classes.
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Endolithic bioerosion is difficult to analyse and to describe, and it usually requires damaging of the sample material. Sponge erosion (Entobia) may be one of the most difficult to evaluate as it is simultaneously macroscopically inhomogeneous and microstructurally intricate. We studied the bioerosion traces of the two Australian sponges Cliona celata Grant, 1826 (sensu Schönberg 2000) and Cliona orientalis Thiele, 1900 with a newly available radiographic technology: high resolution X-ray micro-computed tomography (MCT). MCT allows non-destructive visualisation of live and dead structures in three dimensions and was compared to traditional microscopic methods. MCT and microscopy showed that C. celata bioerosion was more intense in the centre and branched out in the periphery. In contrast, C. orientalis produced a dense, even trace meshwork and caused an overall more intense erosion pattern than C. celata. Extended pioneering filaments were not usually found at the margins of the studied sponge erosion, but branches ended abruptly or tapered to points. Results obtained with MCT were similar in quality to observations from transparent optical spar under the dissecting microscope. Microstructures could not be resolved as well as with e.g. scanning electron microscopy (SEM). Even though sponge scars and sponge chips were easily recognisable on maximum magnification MCT images, they lacked the detail that is available from SEM. Other drawbacks of MCT involve high costs and presently limited access. Even though MCT cannot presently replace traditional techniques such as corrosion casts viewed by SEM, we obtained valuable information. Especially for the possibility to measure endolithic pore volumes, we regard MCT as a very promising tool that will continue to be optimised. A combination of different methods will produce the best results in the study of Entobia.
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This paper describes a 1 : 2 500 000 scale aeromagnetic anomaly map produced by the joint efforts of VNIIOkeangeologia, Polar Marine Geological Research Expedition (PMGRE) and the Alfred Wegener Institute for Polar and Marine Research (AWl) for the Weddell Sea region covering 1 850 000 km' of West Antarctica. Extensive regional magnetic survey flights with line-spacing of about 20 km and 5 km were carried out by the PMGRE between 1977 and 1989. In course of these investigations the PMGRE flew 9 surveys with flight-line spacing of 20 km and 6 surveys with flight-line spacing of 5 km mainly over the mountain areas of southern Palmer Land, western Dronning Maud Land, Coats Land and Pensacola Mountains, over the Ronne lee Shelf and the Filchner Ice Shelf and the central part of the Weddell Sea. More than 215 000 line-kilometers of total field aeromagnetic data have been acquired by using an Ilyushin Il-14 ski-equipped aircraft. Survey operations were centered on the field base stations Druzhnaya-1, -2, and -3, from which the majority of the Weddell Sea region network was completed. The composite map of the Weddell Sea region is prepared in colour, showing magnetic anomaly contours at intervals of 50-100 nT with supplemental contours at an interval of 25 nT in low gradient areas, on a polar stereographic projection. The compiled colour magnetic anomaly map of the Weddell Sea region demonstrates that features of large areal extent, such as geologic provinces, fold-belts, ancient eratonic fragments and other regional structural features can be readily delineated. The map allows a comparison of regional magnetic features with similar-scale geological structures on geological and geophysical maps. It also provides a database for the future production of the ''Digital Magnetic Anomaly Map of Antarctica'' in the framework of the Scientific Committee on Antarctic Research/International Association of Geomagnetism and Aeronomy (SCAR/IAGA) compilation.
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The Box corer is a marine geological and biological sampling tool for soft sediments in lakes or oceans. It is deployed from a research vessel with a deep sea wire and suitable for any water depth. It is designed for a minimum of disturbance of the sediment surface by bow wave effects which is important for quantitative investigations of the benthos micro- to macrofauna, geochemical processes, sampling of bottom water or sedimentology. The large box corer version with an area of 2,500 cm? is frequently used on research vessels since the 1980th years. This data set is a publication of the engeneering drawings.