993 resultados para Zero-One Matrices


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Neodexiopsis Malloch from Bolivia with the description of one new species (Diptera, Muscidae). Neodexiopsis Malloch (Diptera, Muscidae, Coenosiinae) is a very well represented genus in the Neotropical Region, known from almost 100 species. In Bolivia, it is known only from four species: N. declivis, N. incurva, N. oculata and N. recedens, all described by Stein. The study of material from South America deposited at Muséum national d'Histoire naturelle (Paris, France), enabled the description of one new species to science. A key for the recognition of the five species known to Bolivia is given.

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This paper studies how firms make layoff decisions in the presence of adverse shocks. In this uncertain environment, workers' expectations about their job security affect their on-the-job performance. This productivity effect on job insecurity forces firms to strike a balance between laying off redundant workers and maintaining survivors' commitment when deciding on the amount and timing of downsizing. This framework offers an explanation of conservative employment practices (such as zero or reduced layoffs) based on firms having private information about their future profits. High retention rates and wages can signal that the firm has a bright future, boosting workers' confidence. Moreover, the model provides clear predictions about when waves of downsizing will occur as opposed to one-time massive cuts.

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In Switzerland, a two-tier system based on impairment by any psychoactive substances which affect the capacity to drive safely and zero tolerance for certain illicit drugs came into force on 1 January 2005. According to the new legislation, the offender is sanctioned if Delta(9)-tetrahydrocannabinol THC is >or=1.5ng/ml or amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA), cocaine, free morphine are >or=15ng/ml in whole blood (confidence interval+/-30%). For all other psychoactive substances, impairment must be proven in applying the so-called "three pillars expertise". At the same time the legal blood alcohol concentration (BAC) limit for driving was lowered from 0.80 to 0.50g/kg. The purpose of this study was to analyze the prevalence of drugs in the first year after the introduction of the revision of the Swiss Traffic Law in the population of drivers suspected of driving under the influence of drugs (DUID). A database was developed to collect the data from all DUID cases submitted by the police or the Justice to the eight Swiss authorized laboratories between January and December 2005. Data collected were anonymous and included the age, gender, date and time of the event, the type of vehicle, the circumstances, the sampling time and the results of all the performed toxicological analyses. The focus was explicitly on DUID; cases of drivers who were suspected to be under the influence of ethanol only were not considered. The final study population included 4794 DUID offenders (4243 males, 543 females). The mean age of all drivers was 31+/-12 years (range 14-92 years). One or more psychoactive drugs were detected in 89% of all analyzed blood samples. In 11% (N=530) of the samples, neither alcohol nor drugs were present. The most frequently encountered drugs in whole blood were cannabinoids (48% of total number of cases), ethanol (35%), cocaine (25%), opiates (10%), amphetamines (7%), benzodiazepines (6%) and methadone (5%). Other medicinal drugs such as antidepressants and benzodiazepine-like were detected less frequently. Poly-drug use was prevalent but it may be underestimated because the laboratories do not always analyze all drugs in a blood sample. This first Swiss study points out that DUID is a serious problem on the roads in Switzerland. Further investigations will show if this situation has changed in the following years.

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We consider adaptive sequential lossy coding of bounded individual sequences when the performance is measured by the sequentially accumulated mean squared distortion. Theencoder and the decoder are connected via a noiseless channel of capacity $R$ and both are assumed to have zero delay. No probabilistic assumptions are made on how the sequence to be encoded is generated. For any bounded sequence of length $n$, the distortion redundancy is defined as the normalized cumulative distortion of the sequential scheme minus the normalized cumulative distortion of the best scalarquantizer of rate $R$ which is matched to this particular sequence. We demonstrate the existence of a zero-delay sequential scheme which uses common randomization in the encoder and the decoder such that the normalized maximum distortion redundancy converges to zero at a rate $n^{-1/5}\log n$ as the length of the encoded sequence $n$ increases without bound.

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From the year of its foundation, until the foundation of Revista deContabilidad in 1997, REFC has been the only referred accounting journalin Spain. Published by the Spanish Association for Accounting and BusinessAdministration (AECA), this journal is at the heart of the emergence ofa distinctly Spanish academic accounting community.Our study is based on:1. An analysis of 100 issues of REFC covering the period from 1985 to 1999.2. A questionnaire to Spanish accounting academics on their perceptionsand experience of the journal.Key points emerging from this study include:a) A move away from interest in accounting concepts and rules, as wellas accounting history, and towards positive accounting theory, the impactof accounting information on capital markets, and financial analysis.b) The emergence of a small number of universities as the driving forcein Spanish accounting research.c) Spanish academics rate REFC highly compared to other Spanish journalsfor publication status, as a support for research, and as a support forteaching. A number of English language journals are rated more highly forboth publication status and as a support for teaching.

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The aim of this study was to analyze the psychometric properties of the Career Adapt-Abilities Scale (CAAS) in a French-speaking Swiss sample and its relationship with personality dimensions and work engagement. The heterogeneous sample of 391 participants (Mage = 39.59, SD = 12.30) completed the CAAS-International and a short version of the Utrecht Work Engagement Scale. To assess personality dimensions, participants completed either the Zuckerman-Kuhlman-Aluja Personality Questionnaire (n=283) or the NEO-FFI-R (n=108). The internal consistencies for the four subscales and total scores of the CAAS ranged from good to excellent, and skewness and kurtosis values indicated that scores were normally distributed. Gender differences and cor- relations with age were small or negligible. Several CFA models confirmed the factor structure of the French version of the CAAS-International, with loadings very similar to the ones observed for the international form. Adaptability was related to different personality dimensions, particularly neuroticism and conscientiousness, and also to work engagement. When predicting work engage- ment, career adaptability had a significant incremental validity over personality dimensions. Fi- nally, career adaptability partially moderated the relationship between personality and work engagement, suggesting that career adaptability also contributes to regulating the expression of personality dispositions.

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In many research areas (such as public health, environmental contamination, and others) one deals with the necessity of using data to infer whether some proportion (%) of a population of interest is (or one wants it to be) below and/or over some threshold, through the computation of tolerance interval. The idea is, once a threshold is given, one computes the tolerance interval or limit (which might be one or two - sided bounded) and then to check if it satisfies the given threshold. Since in this work we deal with the computation of one - sided tolerance interval, for the two-sided case we recomend, for instance, Krishnamoorthy and Mathew [5]. Krishnamoorthy and Mathew [4] performed the computation of upper tolerance limit in balanced and unbalanced one-way random effects models, whereas Fonseca et al [3] performed it based in a similar ideas but in a tow-way nested mixed or random effects model. In case of random effects model, Fonseca et al [3] performed the computation of such interval only for the balanced data, whereas in the mixed effects case they dit it only for the unbalanced data. For the computation of twosided tolerance interval in models with mixed and/or random effects we recomend, for instance, Sharma and Mathew [7]. The purpose of this paper is the computation of upper and lower tolerance interval in a two-way nested mixed effects models in balanced data. For the case of unbalanced data, as mentioned above, Fonseca et al [3] have already computed upper tolerance interval. Hence, using the notions persented in Fonseca et al [3] and Krishnamoorthy and Mathew [4], we present some results on the construction of one-sided tolerance interval for the balanced case. Thus, in order to do so at first instance we perform the construction for the upper case, and then the construction for the lower case.

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BACKGROUND: Interventions have been developed to reduce overestimations of substance use among others, especially for alcohol and among students. Nevertheless, there is a lack of knowledge on misperceptions of use for substances other than alcohol. We studied the prevalence of misperceptions of use for tobacco, cannabis, and alcohol and whether the perception of tobacco, cannabis, and alcohol use by others is associated with one's own use. METHODS: Participants (n=5216) in a cohort study from a census of 20-year-old men (N=11,819) estimated the prevalence of tobacco and cannabis use among peers of the same age and sex and the percentage of their peers drinking more alcohol than they did. Using the census data, we determined whether participants overestimated, accurately estimated, or underestimated substance use by others. Regression models were used to compare substance use by those who overestimated or underestimated peer substance with those who accurately estimated peer use. Other variables included in the analyses were the presence of close friends with alcohol or other drug problems and family history of substance use. RESULTS: Tobacco use by others was overestimated by 46.1% and accurately estimated by 37.3% of participants. Cannabis use by others was overestimated by 21.8% and accurately estimated by 31.6% of participants. Alcohol use by others was overestimated by more than half (53.4%) of participants and accurately estimated by 31.0%. In multivariable models, compared with participants who accurately estimated tobacco use by others, those who overestimated it reported smoking more cigarettes per week (incidence rate ratio [IRR] [95% CI], 1.17 [range, 1.05, 1.32]). There was no difference in the number of cigarettes smoked per week between those underestimating and those accurately estimating tobacco use by others (IRR [95% CI], 0.99 [range, 0.84, 1.17]). Compared with participants accurately estimating cannabis use by others, those who overestimated it reported more days of cannabis use per month (IRR [95% CI], 1.43 [range, 1.21, 1.70]), whereas those who underestimated it reported fewer days of cannabis use per month (IRR [95% CI], 0.62 [range, 0.23, 0.75]). Compared with participants accurately estimating alcohol use by others, those who overestimated it reported consuming more drinks per week (IRR [95% CI], 1.57 [range, 1.43, 1.72]), whereas those who underestimated it reported consuming fewer drinks per week (IRR [95% CI], 0.41 [range, 0.34, 0.50]). CONCLUSIONS: Perceptions of substance use by others are associated with one's own use. In particular, overestimating use by others is frequent among young men and is associated with one's own greater consumption. This association is independent of the substance use environment, indicating that, even in the case of proximity to a heavy-usage group, perception of use by others may influence one's own use. If preventive interventions are to be based on normative feedback, and their aim is to reduce overestimations of use by others, then the prevalence of overestimation indicates that they may be of benefit to roughly half the population; or, in the case of cannabis, to as few as 20%. Such interventions should take into account differing strengths of association across substances.

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L'objectiu del desenvolupament d'aquest Treball de Final de Carrera és la introducció d'un sistema ERP en una empresa fictícia del sector auxiliar de l'automoció, la qual anomenarem NBJ Automotive.

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ABSTRACT Moncini is the tribe of Hesperiidae that comprises the greatest diversity of small, brown, hard to identify skippers. The group is peculiarly classified as having many monotypic genera, thus offering low informative value to its systematics. This study presents a review of the genus Gallio Evans, 1955, a genus formerly recognized as monotypic, and describes three new species, Gallio imperatriz sp. nov. from Maranhão, Brazil, Gallio furtadoi sp. nov. from Mato Grosso, Brazil and Gallio eti sp. nov. from Madre de Díos, Peru and Acre, Brazil (type locality). A lectotype for Vehilius carasta Schaus, 1902 is designated. Gallio is therefore redescribed and illustrations and diagnosis to its species are provided.

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Résumé : Erythropoietin (EPO) is a glycoprotein hormone endogenously produced by the kidney, whose main physiological role is the stimulation of erythropoiesis. Since the beginning of the nineties, recombinant human EPO (rhEPO), a potent anti-anaemia treatment drug, has been manufactured by pharmaceutical industries. However, the erythropoiesis stimulating power of rhEPO was rapidly misused by unscrupulous athletes in order to improve their performances in endurance sports. Endogenous EPO has the same amino-acid backbone as most of recombinant forms; the molecules however differ through their respective glycosylation patterns. This difference constitutes the basis of the usual EPO screening test (IEF) developed in 2000 and still currently used in all anti-doping laboratories of the world. Nowadays, 3 EPO generations have been commercialized. The fight against EPO abuse is a continuous challenge for anti-doping laboratories. The diversity of recombinant EPO forms and the continuous development of new ones considerably confuse the identification of EPO doping. Several facets of this fight were investigated in this work. One of the limiting aspects of doping agents screening is the availability of positive samples. Therefore, 2nd and 3rd generation EPOS, namely NESP and C.E.R.A., were injected to healthy subjects in the frame of pilot clinical studies. These latter allowed to review the current EPO identification criteria defined by the World Anti-Doping Agency (WADA) in the case of NESP and to validate and implement a new assay targeting C.E.R.A. in human serum. Both studies resulted in the determination of the respective detection windows of NESP and C.E.R.A. in biological fluids. Following that, Dynepo, a 1st generation EPO presenting similarities with the endogenous form, was also in the centre of a similar clinical study. Our work aimed to overcome the actual identification criteria, which are not adapted to Dynpeo, and to propose an alternative pattern classification method based on the discriminant analysis of IEF EPO profiles. This method might be validated for other EPO forms in the future. The detection window of this molecule was also determined. Under particular conditions, confounding effects can complicate the identification of EPO in biological matrices. For example, athletes having performed a strenuous physical effort can excrete modified isoforms of endogenous EPO, making it very similar to some recombinant forms. Such phenomena, called effort urines, were reproduced under controlled conditions and, after characterization of effort EPO, an urinary biochemical marker was proposed to unequivocally identify effort urines. It also happens that EPO analyses fail to detect endogenous levels of EPO. Such profiles were thoroughly investigated and potential causes identified. Natural reasons relying on urine properties and test specificity were underlined, but the possible addition of adulterant agents in urine samples was also considered. Therefore, a simple biochemical assay targeting the suspected substances was set up. Our work was based on the characterization of atypical EPO profiles from different origins. Therefore, 3 EPO molecules representing the 3 generations of the drug and 2 confounding effects confusing the results interpretation were studied. These studies resulted in tangible applications for the laboratory, the best example of which being the C.E.R.A. assay, but also in scientific findings allowing to improve our comprehension of EPO doping in sport.

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OBJECTIVE: To set-up an international cohort of patients suspected with Behçet's disease (BD). The cohort is aimed at defining an algorithm for definition of the disease in children. METHODS: International experts have defined the inclusion criteria as follows: recurrent oral aphthosis (ROA) plus one of following-genital ulceration, erythema nodosum, folliculitis, pustulous/acneiform lesions, positive pathergy test, uveitis, venous/arterial thrombosis and family history of BD. Onset of disease is <16 years, disease duration is ≤3 years, future follow-up duration is ≥4 years and informed consent is obtained. The expert committee has classified the included patients into: definite paediatric BD (PED-BD), probable PED-BD and no PED-BD. Statistical analysis is performed to compare the three groups of patients. Centres document their patients into a single database. RESULTS: At January 2010, 110 patients (56 males/54 females) have been included. Mean age at first symptom: 8.1 years (median 8.2 years). At inclusion, 38% had only one symptom associated with ROA, 31% had two and 31% had three or more symptoms. A total of 106 first evaluations have been done. Seventeen patients underwent the first-year evaluation, and 36 had no new symptoms, 12 had one and 9 had two. Experts have examined 48 files and classified 30 as definite and 18 as probable. Twenty-six patients classified as definite fulfilled the International Study Group criteria. Seventeen patients classified as probable did not meet the international criteria. CONCLUSION: The expert committee has classified the majority of patients in the BD group although they presented with few symptoms independently of BD classification criteria.

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