931 resultados para Operaatio Iraqi Freedom
Resumo:
A series of studies was conducted to compare group differences in the goal orientations of delinquent, at-risk, and not-at-risk adolescents. An Importance of Goals Scale was developed by examining the item responses of 230 high school students and validated by administering the revised scale to 80 delinquent, 90 at-risk, and 90 not-at-risk adolescents. Results identified differences in the importance attributed to different goals by the 3 groups. Delinquent and at-risk adolescents attached significantly more importance to goals associated with developing a social image (e.g., delinquency, freedom-autonomy), whereas not-at-risk adolescents were more concerned with goals associated with an academic image (e.g., educational, interpersonal). Results are discussed in terms of their implications for school achievement, peer relations, and future life paths.
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The popular Newmark algorithm, used for implicit direct integration of structural dynamics, is extended by means of a nodal partition to permit use of different timesteps in different regions of a structural model. The algorithm developed has as a special case an explicit-explicit subcycling algorithm previously reported by Belytschko, Yen and Mullen. That algorithm has been shown, in the absence of damping or other energy dissipation, to exhibit instability over narrow timestep ranges that become narrower as the number of degrees of freedom increases, making them unlikely to be encountered in practice. The present algorithm avoids such instabilities in the case of a one to two timestep ratio (two subcycles), achieving unconditional stability in an exponential sense for a linear problem. However, with three or more subcycles, the trapezoidal rule exhibits stability that becomes conditional, falling towards that of the central difference method as the number of subcycles increases. Instabilities over narrow timestep ranges, that become narrower as the model size increases, also appear with three or more subcycles. However by moving the partition between timesteps one row of elements into the region suitable for integration with the larger timestep these the unstable timestep ranges become extremely narrow, even in simple systems with a few degrees of freedom. As well, accuracy is improved. Use of a version of the Newmark algorithm that dissipates high frequencies minimises or eliminates these narrow bands of instability. Viscous damping is also shown to remove these instabilities, at the expense of having more effect on the low frequency response.
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Familial Mediterranean fever (FMF) is a recessive disorder of inflammation caused by mutations in a gene (designated MEFV) on chromosome 16p13.3, We have recently constructed a 1-Mb cosmid contig that includes the FMF critical region. Here we show genotype data for 12 markers from our physical map, including 5 newly identified microsatellites, in FMF families. Intrafamilial recombinations placed MEFV in the similar to 285 kb between D16S468/D16S3070 and D16S3376. We observed significant linkage disequilibrium in the North African Jewish population, and historical recombinants in the founder haplotype placed MEFV between D16S3082 and D16S3373 (similar to 200 kb). In smaller panels of Iraqi Jewish, Arab, and Armenian families, there were significant allelic associations only for D16S3370 and D16S2617 among the Armenians. A sizable minority of Iraqi Jewish and Armenian carrier chromosomes appeared to be derived from the North African Jewish ancestral haplotype. We observed a unique FMF haplotype common to Iraqi Jews, Arabs, and Armenians and two other haplotypes restricted to either the Iraqi Jewish or the Armenian population. These data support the view that a few major mutations account for a large percentage of the cases of FMF and suggest that same of these mutations arose before the affected Middle Eastern populations diverged from one another. (C) 1997 Academic Press.
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In this study, hypotheses were tested that the quality of leader-member exchanges (LMX) depends on congruity of values between leader and member. Data on negotiating latitude and personal values were gathered from 160 members of 30 work groups in Australian organizations. Factor analysis revealed 5 value dimensions: Freedom, Achievement, Mateship, Obedience, and Coping. Analyses of variance supported the hypothesis that LMX quality is higher when leaders and members share achievement and obedience values. Subsequent exploratory analysis, however, indicated that a more complex model based on compatibility of leader authority and member affiliation values may provide a more complete representation.
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Conclusion. The study shows that there are differences in the measurement of the action potentials with and without the stylet in the Nucleus Freedom Contour Advance that are higher in the apex than in the base of the cochlea. Objectives. To determine if there are differences in the intraoperative impedances and in the neural response telemetry threshold values in the Nucleus Freedom Contour Advance before and after stylet removal. Subjects and methods. This was a prospective clinical study. Intraoperative impedances and neural response telemetry in users of the Freedom Contour Advance Cochlear Implant were measured before and after stylet removal. Results. There was a significant reduction in the impedance values of an average 1.5 k Omega +/- 2.3 in common ground mode and 1.3 k Omega +/- 2.3 for all monopolar modes after the stylet removal (p < 0.001). When analyzing the apical, medium, and basal electrodes, there was a statistically significant reduction in the neural response thresholds after stylet removal only in the apical electrodes (p = 0.001).
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Objective: Uncertainties about the numerous degrees of freedom in ventilator settings leave many unanswered questions about the biophysical determinants of lung injury. We investigated whether mechanical ventilation with high air flow could yield lung mechanical stress even in normal animals. Design. Prospective, randomized, controlled experimental study. Setting: University research laboratory. Subjects. Thirty normal male Wistar rats (180-230 g). Interventions: Rats were ventilated for 2 hrs with tidal volume of 10 mL/kg and either with normal inspiratory air flow (V`) of 10 mL/s (F10) or high V` of 30 mL/s (F30). In the control group, animals did not undergo mechanical ventilation. Because high flow led to elevated respiratory rate (200 breaths/min) and airway peak inspiratory pressure (PIP,aw = 17 cm H2O), two additional groups were established to rule out the potential contribution of these variables: a) normal respiratory rate = 100 breaths/min and V` = 30 mL/sec; and b) PIP,aw = 17 cm H2O and V` 10 mL/sec. Measurements and Main Results: Lung mechanics and histology (light and electron microscopy), arterial blood gas analysis, and type III procollagen messenger RNA expression in lung tissue were analyzed. Ultrastructural microscopy was similar in control and F10 groups. High air flow led to increased lung plateau and peak pressures, hypoxemia, alveolar hyperinflation and collapse, pulmonary neutrophilic infiltration, and augmented type III procollagen messenger RNA expression compared with control rats. The reduction of respiratory rate did not modify the morphofunctional behavior observed in the presence of increased air flow. Even though the increase in peak pressure yielded mechanical and histologic changes, type III procollagen messenger RNA expression remained unaltered. Conclusions: Ventilation with high inspiratory air flow may lead to high tensile and shear stresses resulting in lung functional and morphologic compromise and elevation of type III procollagen messenger RNA expression.
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Background: Oncologic outcomes in men with radiation-recurrent prostate cancer (PCa) treated with salvage radical prostatectomy (SRP) are poorly defined. Objective: To identify predictors of biochemical recurrence (BCR), metastasis, and death following SRP to help select patients who may benefit from SRP. Design, setting, and participants: This is a retrospective, international, multi-institutional cohort analysis. There was amedian follow-up of 4.4 yr following SRP performed on 404 men with radiation-recurrent PCa from 1985 to 2009 in tertiary centers. Intervention: Open SRP. Measurements: BCR after SRP was defined as a serum prostate-specific antigen (PSA) >= 0.1 or >= 0.2 ng/ml (depending on the institution). Secondary end points included progression to metastasis and cancerspecific death. Results and limitations: Median age at SRP was 65 yr of age, and median pre-SRP PSA was 4.5 ng/ml. Following SRP, 195 patients experienced BCR, 64 developed metastases, and 40 died from PCa. At 10 yr after SRP, BCR-free survival, metastasis-free survival, and cancer-specific survival (CSS) probabilities were 37% (95% confidence interval [CI], 31-43), 77% (95% CI, 71-82), and 83% (95% CI, 76-88), respectively. On preoperative multivariable analysis, pre-SRP PSA and Gleason score at postradiation prostate biopsy predicted BCR (p = 0.022; global p < 0.001) and metastasis (p = 0.022; global p < 0.001). On postoperative multivariable analysis, pre-SRP PSA and pathologic Gleason score at SRP predicted BCR (p = 0.014; global p < 0.001) and metastasis (p < 0.001; global p < 0.001). Lymph node involvement (LNI) also predicted metastasis (p = 0.017). The main limitations of this study are its retrospective design and the follow-up period. Conclusions: In a select group of patients who underwent SRP for radiation-recurrent PCa, freedom from clinical metastasis was observed in > 75% of patients 10 yr after surgery. Patients with lower pre-SRP PSA levels and lower postradiation prostate biopsy Gleason score have the highest probability of cure from SRP. (C) 2011 European Association of Urology. Published by Elsevier B. V. All rights reserved.
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This paper briefly outlines how the political scenario and the mobilization of different actors have contributed to the construction of a public health policy in response to the AIDS epidemics in Brazil. Three factors are presented and discussed: the political context of the 1980s, characterized by redemocratization, growth of social movements, and consolidation of the Brazilian health care reform; the socio-cultural context of the 1970s and 1980s, characterized by achievement of individual freedom, which was key to the organization of the AIDS movement; and finally the actions carried out in the international scenario to support the sustainability of the Brazilian domestic policy and the reinforcement of a global response to face the epidemics in lower-middle income economies.
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Purpose To describe the ictal technetium-99 m-ECD SPECT findings in polymicrogyria syndromes (PMG) during epileptic seizures. Methods We investigated 17 patients with PMG syndromes during presurgical workup, which included long-term video-electroencephalographic (EEG) monitoring, neurological and psychiatry assessments, invasive EEG, and the subtraction of ictal-interictal SPECT coregistered to magnetic resonance imaging (MRI) (SISCOM). Results The analysis of the PMG cortex, using SISCOM, revealed intense hyperperfusion in the polymicrogyric lesion during epileptic seizures in all patients. Interestingly, other localizing investigations showed heterogeneous findings. Twelve patients underwent epilepsy surgery, three achieved seizure-freedom, five have worthwhile improvement, and four patients remained unchanged. Conclusions Our study strongly suggests the involvement of PMG in seizure generation or early propagation. Both conventional ictal single-photon emission computed tomography (SPECT) and SISCOM appeared as the single contributive exam to suggest the localization of the epileptogenic zone. Despite the limited number of resective epilepsy surgery in our study (n=9), we found a strong prognostic role of SISCOM in predicting surgical outcome. This result may be of great value on surgical decision-making of whether or not the whole or part of the PMG lesion should be surgically resected.
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The divergence of quantum and classical descriptions of particle motion is clearly apparent in quantum tunnelling(1,2) between two regions of classically stable motion. An archetype of such nonclassical motion is tunnelling through an energy barrier. In the 1980s, a new process, 'dynamical' tunnelling(1-3), was predicted, involving no potential energy barrier; however, a constant of the motion (other than energy) still forbids classically the quantum-allowed motion. This process should occur, for example, in periodically driven, nonlinear hamiltonian systems with one degree of freedom(4-6). Such systems may be chaotic, consisting of regions in phase space of stable, regular motion embedded in a sea of chaos. Previous studies predicted(4) dynamical tunnelling between these stable regions. Here we observe dynamical tunnelling of ultracold atoms from a Bose-Einstein condensate in an amplitude-modulated optical standing wave. Atoms coherently tunnel back and forth between their initial state of oscillatory motion (corresponding to an island of regular motion) and the state oscillating 180 degrees out of phase with the initial state.
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We describe in detail the theory underpinning the measurement of density matrices of a pair of quantum two-level systems (qubits). Our particular emphasis is on qubits realized by the two polarization degrees of freedom of a pair of entangled photons generated in a down-conversion experiment; however, the discussion applies in general, regardless of the actual physical realization. Two techniques are discussed, namely, a tomographic reconstruction (in which the density matrix is linearly related to a set of measured quantities) and a maximum likelihood technique which requires numerical optimization (but has the advantage of producing density matrices that are always non-negative definite). In addition, a detailed error analysis is presented, allowing errors in quantities derived from the density matrix, such as the entropy or entanglement of formation, to be estimated. Examples based on down-conversion experiments are used to illustrate our results.
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In this study we use region-level panel data on rice production in Vietnam to investigate total factor productivity (TFP) growth in the period since reunification in 1975. Two significant reforms were introduced during this period, one in 1981 allowing farmers to keep part of their produce, and another in 1987 providing improved land tenure. We measure TFP growth using two modified forms of the standard Malmquist data envelopment analysis (DEA) method, which we have named the Three-year-window (TYW) and the Full Cumulative (FC) methods. We have developed these methods to deal with degrees of freedom limitations. Our empirical results indicate strong average TFP growth of between 3.3 and 3.5 per cent per annum, with the fastest growth observed in the period following the first reform. Our results support the assertion that incentive related issues have played a large role in the decline and subsequent resurgence of Vietnamese agriculture.
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The relationship between evidence-based medicine (EBM) and clinical judgement is the subject of conceptual and practical dispute. For example, EBM and clinical guidelines are seen to increasingly dominate medical decision-making at the expense of other, human elements, and to threaten the art of medicine. Clinical wisdom always remains open to question. We want to know why particular beliefs are held, and the epistemological status of claims based in wisdom or experience. The paper critically appraises a number of claims and distinctions, and attempts to clarify the connections between EBM, clinical experience and judgement, and the objective and evaluative categories of medicine. I conclude that to demystify clinical wisdom is not to devalue it. EBM ought not be conceived as needing to be limited or balanced by clinical wisdom, since if its language is translatable into terms comprehensible and applicable to individuals, it helps constitute clinical wisdom. Failure to appreciate this constitutive relation will help perpetuate medical paternalism and delay the adoption of properly evidence-based practice, which would be both unethical and unwise.
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The prevention of inherited disabilities is viewed in two contrasting ways – either as enhancing reproductive choice and improving population health, or as discriminating against disabled community members. We argue that modern clinical genetics, including preimplantation genetic diagnosis (PGD), reflects a persistent and defensible desire by the community to prevent disability, rather than as increasing discrimination or threatening to produce a 'new eugenic' society. Screening should be presented as a distinct issue for decision-making about the prevention or acceptance of disability, rather than as a routinely accepted component of antenatal care. The community must improve its understanding of the experiences of those who manage disability, and continue to debate the issues of discrimination, selective genetic prevention and enhancement, reproductive freedom, and eugenics.
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CULTURE is an Artificial Life simulation that aims to provide primary school children with opportunities to become actively engaged in the high-order thinking processes of problem solving and critical thinking. A preliminary evaluation of CULTURE has found that it offers the freedom for children to take part in process-oriented learning experiences. Through providing children with opportunities to make inferences, validate results, explain discoveries and analyse situations, CULTURE encourages the development of high-order thinking skills. The evaluation found that CULTURE allows users to autonomously explore the important scientific concepts of life and living, and energy and change within a software environment that children find enjoyable and easy to use.