943 resultados para 933


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Among the negative consequences of video gaming disorder, decreased participation in sport and exercise has received little attention. This study aimed to assess the longitudinal association between video gaming disorder and the level of sport and exercise in emerging adult men. A questionnaire was completed at baseline and 15-month follow-up by a representative national sample of 4,933 respondents. The seven items of the Game Addiction Scale were used to construct a latent variable representing video gaming disorder. Level of sport and exercise was also self-reported. Cross-lagged path modeling indicated a reciprocal causality between video gaming disorder and the level of sport and exercise, even after adjusting for a large set of confounders. These findings support the need for better promotion of sport and exercise among emerging adults in order to contribute to the prevention of video gaming disorder, and to raise the level of sport and exercise activity in addicted gamers.

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Abstract Objective: To assess the cutoff values established by ROC curves to classify18F-NaF uptake as normal or malignant. Materials and Methods: PET/CT images were acquired 1 hour after administration of 185 MBq of18F-NaF. Volumes of interest (VOIs) were drawn on three regions of the skeleton as follows: proximal right humerus diaphysis (HD), proximal right femoral diaphysis (FD) and first vertebral body (VB1), in a total of 254 patients, totalling 762 VOIs. The uptake in the VOIs was classified as normal or malignant on the basis of the radiopharmaceutical distribution pattern and of the CT images. A total of 675 volumes were classified as normal and 52 were classified as malignant. Thirty-five VOIs classified as indeterminate or nonmalignant lesions were excluded from analysis. The standardized uptake value (SUV) measured on the VOIs were plotted on an ROC curve for each one of the three regions. The area under the ROC (AUC) as well as the best cutoff SUVs to classify the VOIs were calculated. The best cutoff values were established as the ones with higher result of the sum of sensitivity and specificity. Results: The AUCs were 0.933, 0.889 and 0.975 for UD, FD and VB1, respectively. The best SUV cutoffs were 9.0 (sensitivity: 73%; specificity: 99%), 8.4 (sensitivity: 79%; specificity: 94%) and 21.0 (sensitivity: 93%; specificity: 95%) for UD, FD and VB1, respectively. Conclusion: The best cutoff value varies according to bone region of analysis and it is not possible to establish one value for the whole body.

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Some bilingual societies exhibit a distribution of language skills that can- not be explained by economic theories that portray languages as pure commu- nication devices. Such distribution of skills are typically the result of public policies that promote bilingualism among members of both speech commu- nities (reciprocal bilingualism). In this paper I argue that these policies are likely to increase social welfare by diminishing economic and social segmenta- tion between the two communities. However, these gains tend to be unequally distributed over the two communities. As a result, in a large range of circum- stances these policies might not draw su¢ cient support. The model is built upon the communicative value of languages, but also emphasizes the role of linguistic preferences in the behavior of bilingual individuals.

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Inv: I.J.N.

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Soitinnus: piano.

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Multilevel converters provide an attractive solution to bring the benefits of speed-controlled rotational movement to high-power applications. Therefore, multilevel inverters have attracted wide interest in both the academic community and in the industry for the past two decades. In this doctoral thesis, modulation methods suitable especially for series connected H-bridge multilevel inverters are discussed. A concept of duty cycle modulation is presented and its modification is proposed. These methods are compared with other well-known modulation schemes, such as space-vector pulse width modulation and carrier-based modulation schemes. The advantage of the modified duty-cycle modulation is its algorithmic simplicity. A similar mathematical formulation for the original duty cycle modulation is proposed. The modified duty cycle modulation is shown to produce well-formed phase-to-neutral voltages that have lower total harmonic distortion than the space-vector pulse width modulation and the duty cycle modulation. The space-vector-based solution and the duty cycle modulation, on the other hand, result in a better-quality line-to-line voltage and current waveform. The voltage of the DC links in the modules of the series-connected H-bridge inverter are shown to fluctuate while they are under load. The fluctuation causes inaccuracies in the voltage production, which may result in a failure of the flux estimator in the controller. An extension for upper-level modulation schemes, which changes the switching instants of the inverter so that the output voltage meets the reference voltage accurately regardless of the DC link voltages, is proposed. The method is shown to reduce the error to a very low level when a sufficient switching frequency is used. An appropriate way to organize the switching instants of the multilevel inverter is to make only one-level steps at a time. This causes restrictions on the dynamical features of the modulation schemes. The produced voltage vector cannot be rotated several tens of degrees in a single switching period without violating the above-mentioned one-level-step rule. The dynamical capabilities of multilevel inverters are analyzed in this doctoral thesis, and it is shown that the multilevel inverters are capable of operating even in dynamically demanding metal industry applications. In addition to the discussion on modulation schemes, an overvoltage in multilevel converter drives caused by cable reflection is addressed. The voltage reflection phenomenon in drives with long feeder cables causes premature insulation deterioration and also affects the commonmode voltage, which is one of the main reasons for bearing currents. Bearing currents, on the other hand, cause fluting in the bearings, which results in premature bearing failure. The reflection phenomenon is traditionally prevented by filtering, but in this thesis, a modulationbased filterless method to mitigate the overvoltage in multilevel drives is proposed. Moreover, the mitigation method can be implemented as an extension for upper-level modulation schemes. The method exploits the oscillations caused by two consecutive voltage edges so that the sum of the oscillations results in a mitigated peak of the overvoltage. The applicability of the method is verified by simulations together with experiments with a full-scale prototype.

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1869/11/21 (Numéro 933).

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During mitotic cell division, the genetic material packed into chromosomes is divided equally between two daughter cells. Before the separation of the two copies of a chromosome (sister chromatids), each chromosome has to be properly connected with microtubules of the mitotic spindle apparatus and aligned to the centre of the cell. The spindle assembly checkpoint (SAC) monitors connections between microtubules and chromosomes as well as tension applied across the centromere. Microtubules connect to a chromosome via kinetochores, which are proteinaceous organelles assembled onto the centromeric region of the sister chromatids. Improper kinetochore-microtubule attachments activate the SAC and block chromosome segregation until errors are corrected and all chromosomes are connected to the mitotic spindle in a bipolar manner. The purpose of this surveillance mechanism is to prevent loss or gain of chromosomes in daughter cells that according to current understanding contributes to cancer formation. Numerous proteins participate in the regulation of mitotic progression. In this thesis, the mitotic tasks of three kinetochore proteins, Shugoshin 1 (Sgo1), INCENP, and p38 MAP kinase (p38 MAPK), were investigated. Sgo1 is a protector of centromeric cohesion. It is also described in the tension-sensing mechanism of the SAC and in the regulation of kinetochore-microtubule connections. Our results revealed a central role for Sgo1 in a novel branch of kinetochore assembly. INCENP constitutes part of the chromosomal passenger complex (CPC). The other members of the core complex are the Aurora B kinase, Survivin and Borealin. CPC is an important regulatory element of cell division having several roles at various stages of mitosis. Our results indicated that INCENP and Aurora B are highly dynamic proteins at the mitotic centromeres and suggested a new role for CPC in regulation of chromosome movements and spindle structure during late mitosis. The p38 MAPK has been implicated in G1 and G2 checkpoints during the cell cycle. However, its role in mitotic progression and control of SAC signaling has been controversial. In this thesis, we discovered a novel function for p38γ MAPK in chromosome orientation and spindle structure as well as in promotion of viability of mitotic cells.

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Scarcity of long-term series of sediment-related variables has led watershed managers to apply mathematical models to simulate sediment fluxes. Due to the high efforts for installation and maintenance of sedimentological gauges, tracers have been pointed out as an alternative to validate soil redistribution modelling. In this study, the 137Cs technique was used to assess the WASA-SED model performance at the Benguê watershed (933 km²), in the Brazilian semiarid. Qualitatively, good agreement was found among the 137Cs technique and the WASA-SED model results. Nonetheless, quantitatively great differences, up to two orders of magnitude, were found between the two methods. Among the uncertainties inherent to the 137Cs technique, definition of the reference inventory seems to be a major source of imprecision. In addition, estimations of water and sediment fluxes with mathematical models usually also present high uncertainty, contributing to the quantitative differences of the soil redistribution estimates with the two methods.

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OBJETIVO: avaliar os resultados perinatais em gestantes com mais de 35 anos e verificar diferenças nos grupos entre 35 e 39 anos e acima de 40 anos. MÉTODOS: entre janeiro de 2000 e julho de 2003, realizou-se estudo retrospectivo por análise de fichas obstétricas de 3093 gestantes, excluindo-se 933 gestantes. As pacientes foram divididas em 3 grupos: 18 a 29 anos (grupo controle), 30 a 39 anos e mais de 40 anos. A coleta de dados foi realizada por meio de formulário padronizado e os dados foram transferidos para uma planilha eletrônica (Excel - Microsoft Office 2000). Para a análise estatística, foram utilizados o teste do chi2 e o teste de Fisher, sendo considerado risco a (alfa) menor ou igual a 5% e intervalo de confiança de 95%. RESULTADOS: a via de parto mais utilizada para essas pacientes foi a cesárea, tanto no grupo de 35 a 39 anos (438/792; 55,3%), quanto nas gestantes com mais de 40 anos (153/236; 64,8%). A taxa de prematuridade (39/236; 16,5%), o baixo peso ao nascer (37/236; 15,7%) e a restrição de crescimento fetal (38/236; 16,1%) foram mais altas entre as gestantes tardias, com mais de 40 anos, com diferença significante em relação aos demais grupos. Quanto à ocorrência de óbito fetal, foi constatado nas gestantes de 40 anos incidência cinco vezes maior quando comparado aos outros grupos (diferença estatisticamente significante). CONCLUSÃO: a comparação entre o grupo de gestantes de 35 a 39 anos com o grupo controle apenas diferiu significantemente quanto ao índice de cesáreas, o que nos permite sugerir acompanhamento pré-natal diferenciado para o grupo de gestantes acima de 40 anos.

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OBJETIVOS: avaliar e comparar os efeitos do índice de massa corporal (IMC) sobre severidade da incontinência urinária (IU) feminina por meio do questionário de qualidade de vida King's Health Questionnaire (KHQ), variáveis do estudo urodinâmico e dados da anamnese. MÉTODOS: estudo clínico transversal. Foram selecionados 65 pacientes com incontinência urinária de esforço (IUE) que foram divididas em três grupos: Grupo I (IMC entre 18 e 25 kg/m²); Grupo II (IMC entre 25 e 30 kg/m²) e Grupo III (IMC>30 kg/m²). Os domínios do KHQ foram comparados entre esses grupos. Além disso, alguns dados da anamnese e do estudo urodinâmico (presença de noctúria, enurese, urgência e urge-incontinência) foram também relacionados ao IMC calculando-se o OR (Odds Ratio). O IMC, na presença e na ausência de contrações não inibidas do detrusor, bem como no VLPP (valsalva leak point pressure) <60 ou >60 cmH2O foi avaliado. Por fim, foram realizados testes de correlação do IMC com os nove domínios do KHQ a fim de se evidenciar alguma associação. RESULTADOS: o KHQ foi incapaz de registrar, em qualquer um de seus domínios, deterioração da qualidade de vida das mulheres com IU na medida em que ocorreu elevação do IMC. Encontramos OR para a presença de enurese em relação ao IMC de 1,003 [IC: 0,897-1,121], valor p=0,962. Para a noctúria, o OR foi de 1,049 (IC: 0,933-1,18), valor p=0,425. O valor de OR=0,975 (IC: 0,826-1,151), valor p=0,762 foi encontrado para a urgência. No que se refere à urge-incontinência, encontrou-se OR=0,978 (IC: 0,85-1,126), valor p=0,76. Estudou-se o IMC nos grupos com e sem contrações não-inibidas do músculo detrusor e foram encontradas, respectivamente, medianas de 26,4±4,8 e 28,3±5,7 kg/m² (p=0,6). De forma semelhante, as medianas do IMC nos grupos com VLPP<60 e>60 cmH2O foram, respectivamente, de 29,6±4,1 e 27,7±5,7 kg/m² (p=0,2). Finalmente, não tivemos êxito em demonstrar associação do IMC com qualquer um dos nove domínios do KHQ por meio da correlação de Spearman. CONCLUSÃO: não houve associação dos escores do KHQ com o IMC. Também não houve correlação entre os parâmetros clínicos da anamnese e do estudo urodinâmico com o IMC.

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The agouti is a species intensively hunted throughout the Amazon and the semi-arid regions of northeastern Brazil. Considering the current trend in conservation management of wild species, the aim of this study was to determine the morphometric reference to the heart of agouti raised in captivity, based on thoracic and cardiac measurements in these animals. Thirty adult agoutis, 1 to 3 years of age, without clinical signs of cardiac disease were selected. The animals were physically restrained and radiographies in laterolateral (LL) and ventrodorsal (VD) recumbence were produced. The following measures were taken: the apicobasilar length of the heart (at the most cranial height of the Carina region to the heart apex) (AB), maximum width of the heart perpendicular to AB (CD), heart inclination angle (AIC), trachea inclination angle (AIT), distance from the right heart wall (DPTd), distance from the left heart wall (DPTe) and vertical depth of the thorax, and the ventral face of the vertebral column to the dorsal border of the sternum at the level of the trachea bifurcation (H). The ratios between AB/CD, AB/H and CD/H were also analyzed. To calculate the vertebral heart scale (VHS), the AB and CD measurements were laid over the thoracic vertebra starting at T4. Radiographic evaluation showed values consistent with those reported in small animals and some wild and exotic species. The main biometric values in the chest cavity and heart of agouti are arranged as follows: (1) The ratios between AB/H ratio and CD/H were not sensitive for identifying heart increases (p>0.05), while the ratio AB/CD was more sensitive in this identification (p<0.05); (2) AIC: 21.2±6.4º (mean between male and famale); (3) AIT for males and females: 9.93±3.23° and 8.4±3.94°; (4) DPTd and DPTe for males: 0.97±0.40cm and 0.7±0.30cm; (5) DPTd and DPTe for females: 1.12±0.42cm and 01.02±0.43cm; (6) VHS for males and females: 7.75±0.48v e 7.61±0.34v; (7) The caudal vena cava (CVC) was visualized dorsal-cranially and located right of the midline. The data obtained allowed the acquisition of the first reference values for biometry of the heart of agoutis, contributing to better understanding of cardiac morphology and identification of cardiomyopathy in these animals.

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Maatiloilla luonnon monimuotoisuudesta huolehtimisesta hyötyy niin viljelijä kuin ympäröivä luontokin. Jokaiselta tilalta löytyy joitakin luonnonhoitokohteita, joiden hoidosta voi olla viljelyn kannalta taloudellistakin hyötyä. Monimuotoisuuden säilyttäminen maatalousmaisemassa ja peltomaassa on kestävän maataloustuotannon perusta. Tässä oppaassa esitellään maatilan arkiluonnon tunnistamista ja kuvaillaan mahdollisuuksia luonnonhoitotoimenpiteisiin niin pelloilla, metsäsaarekkeilla, reunavyöhykkeillä, perinnebiotoopeilla kuin kosteikoillakin. Tunnistamista havainnollistamaan oppaassa on käytetty valokuvia ja indikaattorilajeja. Tämä opas on osa TEHO Plus -hankkeen tuottamaa materiaalia viljelijöiden ja neuvojien käyttöön, mikä täydentää hankkeen laatimaa Maatilan ympäristökäsikirjaa.

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The purpose of the present study was to examine the factor structure and psychometric properties of the Social Phobia and Anxiety Inventory for Children (SPAI-C), an instrument developed in the United States and applied to a sample of Brazilian schoolchildren. The process included the translation of the original material from English into Portuguese by two bilingual psychiatrists and a back translation by a bilingual physician. Both the front and back translations were revised by a bilingual child psychiatrist. The study was performed using a cross-sectional design and the Portuguese version of the SPAI-C was applied to a sample of 1954 children enrolled in 3rd to 8th grade attending 2 private and 11 public schools. Eighty-one subjects were excluded due to an incomplete questionnaire and 2 children refused to participate. The final sample consisted of 1871 children, 938 girls (50.1%) and 933 boys (49.8%), ranging in age from 9 to 14 years. The majority of the students were Caucasian (89.0%) and the remainder were African-Brazilian (11.0%). The Pearson product-moment correlation showed that the two-week test-retest reliability coefficient was r = 0.780 and Cronbach's alpha was 0.946. The factor structure was almost similar to that reported in previous studies. The results regarding the internal consistency, the test-retest reliability and the factor structure were similar to the findings obtained in studies performed on English speaking children. The present study showed that the Portuguese language version of SPAI-C is a reliable and valid measure of social anxiety for Brazilian children.