995 resultados para Rb fountain frequency standard


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OBJECTIVE: The cause precipitating intracranial aneurysm rupture remains unknown in many cases. It has been observed that aneurysm ruptures are clustered in time, but the trigger mechanism remains obscure. Because solar activity has been associated with cardiovascular mortality and morbidity, we decided to study its association to aneurysm rupture in the Swiss population. METHODS: Patient data were extracted from the Swiss SOS database, at time of analysis covering 918 consecutive patients with angiography-proven aneurysmal subarachnoid hemorrhage treated at 7 Swiss neurovascular centers between January 1, 2009, and December 31, 2011. The daily rupture frequency (RF) was correlated to the absolute amount and the change in various parameters of interest representing continuous measurements of solar activity (radioflux [F10.7 index], solar proton flux, solar flare occurrence, planetary K-index/planetary A-index, Space Environment Services Center [SESC] sunspot number and sunspot area) using Poisson regression analysis. RESULTS: During the period of interest, there were 517 days without recorded aneurysm rupture. There were 398, 139, 27, 12, 1, and 1 days with 1, 2, 3, 4, 5, and 6 ruptures per day. Poisson regression analysis demonstrated a significant correlation of F10.7 index and RF (incidence rate ratio [IRR] = 1.006303; standard error (SE) 0.0013201; 95% confidence interval (CI) 1.003719-1.008894; P < 0.001), according to which every 1-unit increase of the F10.7 index increased the count for an aneurysm to rupture by 0.63%. A likewise statistically significant relationship of both the SESC sunspot number (IRR 1.003413; SE 0.0007913; 95% CI 1.001864-1.004965; P < 0.001) and the sunspot area (IRR 1.000419; SE 0.0000866; 95% CI 1.000249-1.000589; P < 0.001) emerged. All other variables analyzed showed no significant correlation with RF. CONCLUSIONS: We found greater radioflux, SESC sunspot number, and sunspot area to be associated with an increased count of aneurysm rupture. The clinical meaningfulness of this statistical association must be interpreted carefully and future studies are warranted to rule out a type-1 error.

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Latinalaisen Amerikan osuus maailmantaloudesta on pieni verrattuna sen maantieteelliseen kokoon, väkilukuun ja luonnonvaroihin. Aluetta pidetään kuitenkin yhtenä tulevaisuuden merkittävistä kasvumarkkinoista. Useissa Latinalaisen Amerikan maissa on teollisuutta, joka hyödyntää luonnonvaroja ja tuottaa raaka-aineita sekä kotimaan että ulkomaiden markkinoille. Tällaisia tyypillisiä teollisuudenaloja Latinalaisessa Amerikassa ovat kaivos- ja metsäteollisuus sekä öljyn ja maakaasun tuotanto. Näiden teollisuudenalojen tuotantolaitteiden ja koneiden valmistusta ei Latinalaisessa Amerikassa juurikaan ole. Ne tuodaan yleensä Pohjois-Amerikasta ja Euroopasta. Tässä diplomityössä tutkitaan sähkömoottorien ja taajuusmuuttajien markkinapotentiaalia Latinalaisessa Amerikassa. Tutkimuksessa perehdytään Latinalaisen Amerikan maiden kansantalouksien tilaan sekä arvioidaan sähkömoottorien ja taajuusmuuttajien markkinoiden kokoa tullitilastojen avulla. Chilen kaivosteollisuudessa arvioidaan olevan erityistä potentiaalia. Diplomityössä selvitetään ostoprosessin kulkua Chilen kaivosteollisuudessa ja eri asiakastyyppien roolia siinä sekä tärkeimpiä päätöskriteerejä toimittaja- ja teknologiavalinnoissa.

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Työn tavoitteena oli arvioida ja selvittää toimittajasuhteeseen vaikuttavia tekijöitä JOT Automation Group Oyj.n ja sen alihankkijoiden välisessä yhteistyössä ja muodostaa yrityksen kilpailukykyä parantava toimittaja-arviointiprosessi. Työssä keskityttiin tarkastelemaan yleisillä materiaali- ja komponenttimarkkinoilla toimivia toimittajia elektroniikkateollisuuden tuotantojärjestelmien valmistuksessa. Ensin tutustuttiin toimittajasuhdetta ja sen arviointia käsitelleeseen kirjallisuuteen. Teorian tueksi tehtiin haastatteluja ja kartoitettiin ensisijaisia tarpeita ja tavoitteita arviointiprosessille. Valmis prosessi testattiin käytännössä kahden eri case-esimerkin avulla. Prosessista muodostui kahteen eri työkaluun jakautunut kokonaisuus, joista auditointi arvioi toimittajan kyvykkyyttä vastatta sille asetettuihin vaatimuksiin. Toimittajan suorituskyvyn mittaaminen puolestaan testaa ja vertaa jatkuvasti toiminnan todellista tasoa auditoinnissa saatuihin tuloksiin. Työ sisältää selvityksen ja ohjeistuksen toimittaja-arviointiprosessin käytöstä. Prosessin käyttö alentaa toimittajaan kohdistuvaa materiaalien saatavuuteen ja hankintaan liittyviä riskejä. Esimerkeistä saadut kokemukset osoittivat, että prosessin avulla päästään pureutumaan tärkeisiin ydinalueisiin ja kehittämään niitä sekä toimittajalle, että ostajayritykselle edullisella tavalla. Toimittaja-arviointiprosessista kehittyy toimintatapa yrityksen ja sen toimittajan välisen suhteen ylläpitämiseksi.

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Next-generation sequencing (NGS) technologies have become the standard for data generation in studies of population genomics, as the 1000 Genomes Project (1000G). However, these techniques are known to be problematic when applied to highly polymorphic genomic regions, such as the human leukocyte antigen (HLA) genes. Because accurate genotype calls and allele frequency estimations are crucial to population genomics analyses, it is important to assess the reliability of NGS data. Here, we evaluate the reliability of genotype calls and allele frequency estimates of the single-nucleotide polymorphisms (SNPs) reported by 1000G (phase I) at five HLA genes (HLA-A, -B, -C, -DRB1, and -DQB1). We take advantage of the availability of HLA Sanger sequencing of 930 of the 1092 1000G samples and use this as a gold standard to benchmark the 1000G data. We document that 18.6% of SNP genotype calls in HLA genes are incorrect and that allele frequencies are estimated with an error greater than ±0.1 at approximately 25% of the SNPs in HLA genes. We found a bias toward overestimation of reference allele frequency for the 1000G data, indicating mapping bias is an important cause of error in frequency estimation in this dataset. We provide a list of sites that have poor allele frequency estimates and discuss the outcomes of including those sites in different kinds of analyses. Because the HLA region is the most polymorphic in the human genome, our results provide insights into the challenges of using of NGS data at other genomic regions of high diversity.

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OBJECTIVE: In contrast to conventional (CONV) neuromuscular electrical stimulation (NMES), the use of "wide-pulse, high-frequencies" (WPHF) can generate higher forces than expected by the direct activation of motor axons alone. We aimed at investigating the occurrence, magnitude, variability and underlying neuromuscular mechanisms of these "Extra Forces" (EF). METHODS: Electrically-evoked isometric plantar flexion force was recorded in 42 healthy subjects. Additionally, twitch potentiation, H-reflex and M-wave responses were assessed in 13 participants. CONV (25Hz, 0.05ms) and WPHF (100Hz, 1ms) NMES consisted of five stimulation trains (20s on-90s off). RESULTS: K-means clustering analysis disclosed a responder rate of almost 60%. Within this group of responders, force significantly increased from 4% to 16% of the maximal voluntary contraction force and H-reflexes were depressed after WPHF NMES. In contrast, non-responders showed neither EF nor H-reflex depression. Twitch potentiation and resting EMG data were similar between groups. Interestingly, a large inter- and intrasubject variability of EF was observed. CONCLUSION: The responder percentage was overestimated in previous studies. SIGNIFICANCE: This study proposes a novel methodological framework for unraveling the neurophysiological mechanisms involved in EF and provides further evidence for a central contribution to EF in responders.

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Flood simulation studies use spatial-temporal rainfall data input into distributed hydrological models. A correct description of rainfall in space and in time contributes to improvements on hydrological modelling and design. This work is focused on the analysis of 2-D convective structures (rain cells), whose contribution is especially significant in most flood events. The objective of this paper is to provide statistical descriptors and distribution functions for convective structure characteristics of precipitation systems producing floods in Catalonia (NE Spain). To achieve this purpose heavy rainfall events recorded between 1996 and 2000 have been analysed. By means of weather radar, and applying 2-D radar algorithms a distinction between convective and stratiform precipitation is made. These data are introduced and analyzed with a GIS. In a first step different groups of connected pixels with convective precipitation are identified. Only convective structures with an area greater than 32 km2 are selected. Then, geometric characteristics (area, perimeter, orientation and dimensions of the ellipse), and rainfall statistics (maximum, mean, minimum, range, standard deviation, and sum) of these structures are obtained and stored in a database. Finally, descriptive statistics for selected characteristics are calculated and statistical distributions are fitted to the observed frequency distributions. Statistical analyses reveal that the Generalized Pareto distribution for the area and the Generalized Extreme Value distribution for the perimeter, dimensions, orientation and mean areal precipitation are the statistical distributions that best fit the observed ones of these parameters. The statistical descriptors and the probability distribution functions obtained are of direct use as an input in spatial rainfall generators.

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BACKGROUND: Survival outcomes for patients with glioblastoma remain poor, particularly for patients with unmethylated O(6)-methylguanine-DNA methyltransferase (MGMT) gene promoter. This phase II, randomized, open-label, multicenter trial investigated the efficacy and safety of 2 dose regimens of the selective integrin inhibitor cilengitide combined with standard chemoradiotherapy in patients with newly diagnosed glioblastoma and an unmethylated MGMT promoter. METHODS: Overall, 265 patients were randomized (1:1:1) to standard cilengitide (2000 mg 2×/wk; n = 88), intensive cilengitide (2000 mg 5×/wk during wk 1-6, thereafter 2×/wk; n = 88), or a control arm (chemoradiotherapy alone; n = 89). Cilengitide was administered intravenously in combination with daily temozolomide (TMZ) and concomitant radiotherapy (RT; wk 1-6), followed by TMZ maintenance therapy (TMZ/RT→TMZ). The primary endpoint was overall survival; secondary endpoints included progression-free survival, pharmacokinetics, and safety and tolerability. RESULTS: Median overall survival was 16.3 months in the standard cilengitide arm (hazard ratio [HR], 0.686; 95% CI: 0.484, 0.972; P = .032) and 14.5 months in the intensive cilengitide arm (HR, 0.858; 95% CI: 0.612, 1.204; P = .3771) versus 13.4 months in the control arm. Median progression-free survival assessed per independent review committee was 5.6 months (HR, 0.822; 95% CI: 0.595, 1.134) and 5.9 months (HR, 0.794; 95% CI: 0.575, 1.096) in the standard and intensive cilengitide arms, respectively, versus 4.1 months in the control arm. Cilengitide was well tolerated. CONCLUSIONS: Standard and intensive cilengitide dose regimens were well tolerated in combination with TMZ/RT→TMZ. Inconsistent overall survival and progression-free survival outcomes and a limited sample size did not allow firm conclusions regarding clinical efficacy in this exploratory phase II study.

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Pienitehoisessa taajuusmuuttajassa verkkojännite tasasuunnataan yleisesti diodisillalla. Taajuusmuuttajaa kuormitettaessa diodisilta aiheuttaa sen, että verkosta otettava virta on epäsinimuotoista ja sisältää runsaasti eri kertalukujen yliaaltoja. Tällainen virta vääristää verkon jännitettä sekä aiheuttaa häviöitä, resonansseja ja toimintaepävarmuutta sähkönjakeluverkkoon liitetyissä laitteissa ja komponenteissa. Työssä on tarkasteltu pienitehoisen kolmivaiheisen taajuusmuuttajan tulovirrassa esiintyviä yliaaltoja ja keinoja niiden rajoittamiseksi. Laitevalmistajien osalta syynä aiheen tutkimiseen ja kiinnostavuuteen ovat lähinnä uudet yliaaltoja käsittelevät standardit. Työssä onkin tutustuttu tarvittavin osin standardoinnin nykytilaan sekä seurattu standardeja valmistelevien työryhmien työtä ja tätä kautta perehdytty alaa käsittelevien standardien tulevaisuudennäkymiin Euroopan Unionin alueella. Käsittely on kohdistettu kolmivaiheisiin laitteisiin. Standardi IEC 61000-3-2 asettaa yliaaltorajat ammattikäyttöön tarkoitetuille laitteille, kun laitteen tuloteho on korkeintaan 1 kW. Tällä tehoalueella riittää kolmivaihelaitteille kuristimilla suoritettu passiivinen suodatus täyttämään asetetut viranomaisvaatimukset. Tähän liittyen on suunniteltu kolmivaihekuristin, joka on tarkoitettu käytettäväksi taajuusmuuttajasarjan lisävarusteena tehoalueella 0.12…2.2 kW.

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This paper describes an evaluation framework that allows a standardized and quantitative comparison of IVUS lumen and media segmentation algorithms. This framework has been introduced at the MICCAI 2011 Computing and Visualization for (Intra)Vascular Imaging (CVII) workshop, comparing the results of eight teams that participated. We describe the available data-base comprising of multi-center, multi-vendor and multi-frequency IVUS datasets, their acquisition, the creation of the reference standard and the evaluation measures. The approaches address segmentation of the lumen, the media, or both borders; semi- or fully-automatic operation; and 2-D vs. 3-D methodology. Three performance measures for quantitative analysis have been proposed. The results of the evaluation indicate that segmentation of the vessel lumen and media is possible with an accuracy that is comparable to manual annotation when semi-automatic methods are used, as well as encouraging results can be obtained also in case of fully-automatic segmentation. The analysis performed in this paper also highlights the challenges in IVUS segmentation that remains to be solved.

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Several clinical studies have reported that EEG synchrony is affected by Alzheimer’s disease (AD). In this paper a frequency band analysis of AD EEG signals is presented, with the aim of improving the diagnosis of AD using EEG signals. In this paper, multiple synchrony measures are assessed through statistical tests (Mann–Whitney U test), including correlation, phase synchrony and Granger causality measures. Moreover, linear discriminant analysis (LDA) is conducted with those synchrony measures as features. For the data set at hand, the frequency range (5-6Hz) yields the best accuracy for diagnosing AD, which lies within the classical theta band (4-8Hz). The corresponding classification error is 4.88% for directed transfer function (DTF) Granger causality measure. Interestingly, results show that EEG of AD patients is more synchronous than in healthy subjects within the optimized range 5-6Hz, which is in sharp contrast with the loss of synchrony in AD EEG reported in many earlier studies. This new finding may provide new insights about the neurophysiology of AD. Additional testing on larger AD datasets is required to verify the effectiveness of the proposed approach.

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RESUMO A podridão-olho-de-boi (Cryptosporiosis perennans) e a podridão-branca (Botryosphaeria dothidea) estão entre as principais doenças de verão da macieira no Brasil. O objetivo deste trabalho foi avaliar o efeito de uma película protetora constituída de cera de carnaúba e argilas (Raynox® ), nas doses de 2,5 e 5,0%, na infecção por C. perennans e por B. dothidea em maçãs das cultivares Fuji Standard e Pink Lady. As macieiras foram pulverizadas cinco vezes de dezembro de 2007 a março de 2008, conforme previsão de condições adequadas para ocorrência dos danos e crescimento dos frutos. Na colheita, as maçãs foram inoculadas com os dois patógenos e avaliadas quanto à incidência das podridões. Indiferente à dose, o uso de Raynox® reduziu a incidência da podridão-branca e da podridão-olho-de-boi em 67% e 42% na ‘Fuji Standard’, e 43% e 42% na ‘Pink Lady’, respectivamente. O incremento da dose aumentou a eficiência do produto para o controle da podridão-olho-de-boi. Na dose de 2,5%, o controle da podridão-olho-de-boi foi de 19% e 20%, respectivamente, em maçãs ‘Fuji Standard’ e ‘Pink Lady’, enquanto para as mesmas cultivares, mas com a dose de 5,0%, estes valores foram de 65% e 63%. Mais estudos são necessários para o ajuste de dose e critérios de aplicação para que o protetor solar possa ser recomendado.

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One of the most important reference groups for Mycenaean pottery is the Mycenae/Berbati (MB). In several studies, a second group has been identified (MBKR). The chemical compositions were similar to MB, but with important differences in the Na, K and Rb contents. The present study suggests that these differences are due to selective alteration and contamination processes that are indirectly determined by the original firing temperature. Therefore, groups MB and MBKR should be considered as a single reference group.