960 resultados para Population viability analysis


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We show that an arbitrary system described by two dipole moments exhibits coherent superpositions of internal states that can be completely decoupled fi om the dissipative interactions (responsible for decoherence) and an external driving laser field. These superpositions, known as dark or trapping states, can he completely stable or can coherently interact with the remaining states. We examine the master equation describing the dissipative evolution of the system and identify conditions for population trapping and also classify processes that can transfer the population to these undriven and nondecaying states. It is shown that coherent transfers are possible only if the two systems are nonidentical, that is the transitions have different frequencies and/or decay rates. in particular, we find that the trapping conditions can involve both coherent and dissipative interactions, and depending on the energy level structure of the system, the population can be trapped in a linear superposition of two or more bare states, a dressed state corresponding to an eigenstate of the system plus external fields or, in some cases. in one of the excited states of the system. A comprehensive analysis is presented of the different processes that are responsible for population trapping, and we illustrate these ideas with three examples of two coupled systems: single V- and Lambda-type three-level atoms and two nonidentical tao-level atoms, which are known to exhibit dark states. We show that the effect of population trapping does not necessarily require decoupling of the antisymmetric superposition from the dissipative interactions. We also find that the vacuum-induced coherent coupling between the systems could be easily observed in Lambda-type atoms. Our analysis of the population trapping in two nonidentical atoms shows that the atoms can be driven into a maximally entangled state which is completely decoupled from the dissipative interaction.

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Objective To determine patterns of dental set-vices provided to a cohort of the insured population 18 years and over, in private general practice in New South Wales, Australia. Basic research design A cohort study using the person-years method and Poisson regression for analysis. Setting Data were derived from claims records submitted by members of a health insurance fund (Government Employees Health Fund-GEHF) for rebates during the study period 1 January 1992-31 December 1995. Participants There were 133,467 members aged 18 years and over from New South Wales. Main outcome measures To determine, by age group, for those members who used private general practice and made a claim (referred to as 'patients') the annual number of visits, total number of services received per year and number of services received at a visit, Results The mean number of visits per patient was 2.4 per year with patients under 45 years making fewer visits than the 45-54 age group reference category. Mean number of services utilised per patient-year was 5.9, with services provided increasing from 3.5 for the 18-24-year-old group, reaching a plateau of approximately 6.2 for those aged 45 years or more. The number of services received per visit was 2.4 and there were no differences by age. Service mix was dominated by restorative (35%), diagnostic (27%), and preventive services (18%); with age specific variations observed. Conclusions Age was found to be an important determinant in the use of dental services, independent of membership duration and gender.

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Targeting is increasingly used to manage people. It operates by segmenting populations and providing different levels of opportunities and services to these groups. Each group is subject to different levels of surveillance and scrutiny. This article examines the deployment of targeting in Australian social security. Three case studies of targeting are presented in Australia's management of benefit overpayment and fraud, the distribution of employment services and the application of workfare. In conceptualizing surveillance as governance, the analysis examines the rationalities, technologies and practices that make targeting thinkable, practicable and achievable. In the case studies, targeting is variously conceptualized and justified by calculative risk discourses, moral discourses of obligation and notions of welfare dependency Advanced information technologies are also seen as particularly important in giving rise to the capacity to think about and act on population segments.

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Loss of connectivity in impounded rivers is among the impacts imposed by dams, and mitigation measures such as fish passages might not accomplish their purpose of reestablishing an efficient bi-directional gene flow in the fish populations affected. As a consequence, fish populations remain fragmented, and a new interpopulational structure may develop, with increased risk of reduced genetic diversity and stochastic extinction. In order to evaluate the effects of the Gavio Peixoto Dam, which was constructed almost a century ago on the Jacar,-Gua double dagger u River in the Upper Parana River basin, Brazil, a comparative morphometric study was undertaken on the populations of the Neotropical migratory characid fish Salminus hilarii living up- and downstream of this dam. Population dynamics, spatial segregation, and habitat use by different age classes were monitored for 2 years. We found that segregation caused by the dam and long periods with no efficient connection by fish passages have led to fragmentation and interpopulational structuring of S. hilarii, as revealed by canonical variable analysis of morphometric features. The fish populations occupying the up- and downstream sections have succeeded in performing short-distance reproductive migrations in the main river and tributaries, have found suitable habitats for completing their life cycle, and have been able to maintain distinct small-sized populations so far.

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Objective: To compare rates of self-reported use of health services between rural, remote and urban South Australians. Methods: Secondary data analysis from a population-based survey to assess health and well-being, conducted in South Australia in 2000. In all, 2,454 adults were randomly selected and interviewed using the computer-assisted telephone interview (CATI) system. We analysed health service use by Accessibility and Remoteness Index of Australia (ARIA) category. Results: There was no statistically significant difference in the median number of uses of the four types of health services studied across ARIA categories. Significantly fewer residents of highly accessible areas reported never using primary care services (14.4% vs. 22.2% in very remote areas), and significantly more reported high use ( greater than or equal to6 visits, 29.3% vs. 21.5%). Fewer residents of remote areas reported never attending hospital (65.6% vs. 73.8% in highly accessible areas). Frequency of use of mental health services was not statistically significantly different across ARIA categories. Very remote residents were more likely to spend at least one night in a public hospital (15.8%) than were residents of other areas (e.g. 5.9% for highly accessible areas). Conclusion: The self-reported frequency of use of a range of health services in South Australia was broadly similar across ARIA categories. However, use of primary care services was higher among residents of highly accessible areas and public hospital use increased with increasing remoteness. There is no evidence for systematic rural disadvantage in terms of self-reported health service utilisation in this State.

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Study objective: To investigate the effect of the voluntary folate fortification policy in Australia on serum folate and total plasma homocysteine (tHcy) concentrations. Design: Population based cohort study. Setting: Perth, Western Australia. Participants: Men and women aged 27 to 77 years (n = 468), who were originally randomly selected from the Perth electoral roll. The cohort was surveyed in 1995/96 before widespread introduction of folate fortification of a variety of foods, and followed up on two occasions, firstly in 1998/99 and again in 2001, when a moderate number of folate fortified foods were available. Subjects with abnormal serum creatinine concentrations at baseline were excluded from this analysis. Main results: Repeated measures analysis of variance was used to determine changes in serum folate and tHcy over the three surveys and to assess whether time trends were related to age, sex, MTHFR C677T genotype, or consumption of folate fortified foods. An increase (38%) in mean serum folate (p < 0.0005) and a decrease (21%) in mean tHcy (p < 0.0005) were seen after introduction of the voluntary folate fortification policy in Australia. Serum folate was consistently higher (p = 0.032) and tHcy was consistently lower (p = 0.001) in subjects who consumed at least one folate fortified food compared with subjects who did not consume any folate fortified foods in the previous week. The time related changes in serum folate and tHcy were affected only by intake of folate fortified foods (p < 0.0005) and not by any other measured variables including age, sex, or MTHFR genotype. Conclusion: Voluntary fortification of foods with folate in Australia has been followed by a substantial increase in serum folate and decrease in tHcy in the general population.

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The squat lobster Pleuroncodes monodon is one of the most common and abundant galatheid species in the deepwater fishery of Pacific coast of America. In contrast with Peru and Chile, the red squat lobster is not commercially exploited in Costa Rica. Here we estimated the size of sexual maturity and analysed egg production in P. monodon from the Pacific of Costa Rica; the results might be important for an adequate management strategy when initiating a sustainable fishery of this resource in Costa Rica. Analyses of allometric growth revealed that females and males reached their morphological sexual maturity at 26.9 and 30.4 mm CL. respectively. The percentage of immature females captured in the present study (54%) suggests that almost half of females are able to reproduce before they are caught. Egg production was positively correlated with body size; females that measured between 24.1 and 29.0 mm CL contributed roughly 90% to the offspring production of the population. Females from Costa Rica had a considerably lower average egg volume (0.039 mm(3)) and higher fecundity (9810) than females from Chile. In comparison to other American galatheids P. monodon from Costa Rica produces numerous but small eggs, a typical strategy of species with a prolonged larval development. An analysis between our results and information published about P. monodon from Chile also revealed differences in the size-frequency distribution shape of both populations. The non-exploited character of the Costa Rican P. monodon population and a latitudinal (temperature-related) cline in body size might be associated with these differences. (C) 2010 Elsevier B.V. All rights reserved.

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Objective. To describe homicide mortality in the municipality of Sao Paulo according to type of weapon, sex, race or skin color, age, and areas of socioeconomic inequalities, between 1996 and 2008. Method. For this ecological time-series study, data about deaths in the municipality of Sao Paulo were collected from the municipal program for improvement of mortality information, using International Classification of Diseases, 10th revision (ICD-10) codes. Homicide mortality rates (HMR) were calculated for the overall population and specifically for each sex, race or skin color, age range, type of weapon, and occurrence in social deprivation/affluence areas. HMR were adjusted for age using the direct method. The percentage age of variation in HMR was calculated for the study period. For areas of socioeconomic inequalities, the relative risk of death from homicide was calculated. Results. HMR fell 73.7% between 2001 and 2008. A reduction in HMR was observed in all groups, especially males (-74.5%), young men between 15 and 24 years of age (-78.0%), and residents in areas of extreme socioeconomic deprivation (-79.3%). The reduction occurred mostly in firearm homicide rates (-74.1%). The relative risk of death from homicide in areas of extreme socioeconomic deprivation, as compared to areas with some degree of socioeconomic deprivation, was 2.77 in 1996, 3.9 in 2001, and 2.13 in 2008. In areas of high socioeconomic deprivation, the relative risk was 2.07 in 1996 and 1.96 in 2008. Conclusions. To understand the reduction in homicide rates in the municipality of Sao Paulo, it is important to take into consideration macrodeterminants that affect the entire municipality and all population subgroups, as well as micro/local determinants that have special impact on homicides committed with firearms and on subgroups such as the young, males, and residents of areas of high socioeconomic deprivation.

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Objective: To investigate: 1) the impact of clinical varicocele on reactive oxygen species (ROS) levels in neat and washed semen in a proven fertile population; and 2) the correlation between ROS levels, testicular volume, and varicocele grade in the same population of fertile men. Design: Prospective controlled clinical study. Setting: Andrology laboratory at tertiary-care hospital. Patient(s): One hundred fourteen healthy fertile men (81 normal fertile and 33 fertile with clinical varicocele) and 30 infertile patients (control subjects). Intervention(s): Standard semen analysis and measurement of sperm ROS production. Main Outcome Measure(s): Seminal parameters, seminal ROS levels, seminal leukocyte levels, clinical varicocele, and testis size. Result(s): Thirty-three of the 11.4 (29%) fertile men had clinical varicocele (grade 1, n = 14; grade 2, n = 11; and grade 3, n = 8), and the remaining 81 (71%) had a normal physical examination. Levels of ROS and semen quality did not differ significantly between the fertile men with or without varicocele. No significant differences in ROS levels in neat and washed semen were observed compared with fertile men with grades 2 and 3 varicocele and with fertile men with varicocele grade 1. The ROS levels in neat and washed semen were not significantly correlated with varicocele grade in fertile men. No significant correlations between ROS levels and testis volume were observed between the fertile groups. Conclusion(s): The presence of clinical varicocele in fertile men is not associated with higher seminal ROS levels or abnormal semen parameters. Levels of ROS are not correlated with varicocele grade or testis volume in the same population of fertile men.

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Oral squamous cell carcinoma (OSCC) is associated with high morbidity and mortality which is due, at least in part, to late detection. Precancerous and cancerous oral lesions may mimic any number of benign oral lesions, and as such may be left without investigation and treatment until they are well advanced. Over the past several years there has been renewed interest in oral cytology as an adjuvant clinical tool in the investigation of oral mucosal lesions. The purpose of the present study was to compare the usefulness of ploidy analysis after Feulgen stained cytological thin-prep specimens with traditional incisional biopsy and routine histopathological examination for the assessment of the pre-malignant potential of oral mucosal lesions. An analysis of the cytological specimens was undertaken with virtual microscopy which allowed for rapid and thorough analysis of the complete cytological specimen. 100 healthy individuals between 30 and 70 years of age, who were non-smokers, non-drinkers and not taking any medication, had cytological specimens collected from both the buccal mucosa and lateral margin of tongue to establish normal cytology parameters within a control population. Patients with a presumptive clinical diagnosis of lichen planus, leukoplakia or OSCC had lesional cytological samples taken prior to their diagnostic biopsy. Standardised thin preparations were prepared and each specimen stained by both Feuglen and Papanicolau methods. High speed scanning of the complete slide at 40X magnification was undertaken using the Aperio Scanscope TM and the green channel of the resultant image was analysed after threshold segmentation to isolate only nuclei and the integrated optical density of each nucleus taken as a gross measure of the DNA content (ploidy). Preliminary results reveal that ploidy assessment of oral cytology holds great promise as an adjunctive prognostic factor in the analysis of the malignant potential of oral mucosal lesions.

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Background The objective of this study was to evaluate the early results of the laparoscopic interposition of a segment of ileum associated with a sleeve gastrectomy (LII-SG) in order to treat patients with type 2 diabetes mellitus (T2DM) and BMI <35. Data regarding morbidly obese diabetic patients subjected to surgery has consistently been validated. To date, there is scarce information about morbidity and mortality related to the surgical treatment of a ""true"" typical diabetic population with BMI <35. Methods The procedures were performed in 454 patients (322 male, 132 female). Mean age was 53.6 +/- 8 years (range = 27-75). Mean BMI was 29.7 +/- 3.6 kg/m(2) (range = 19-34.8). All patients had the diagnosis of T2DM for at least 3 years. Insulin therapy was used by 45.6% of patients. Mean duration of T2DM was 10.8 +/- 5.9 years (range = 3-35). Mean hemoglobin A(1c) was 8.8 +/- 1.9%. Dyslipidemia was observed in 78.4%, hypertension in 64.8%, nephropathy in 28.6%, retinopathy in 32.6%, neuropathy in 34.6%, and coronary heart disease in 13%. Results There was no conversion to open surgery. All patients were evaluated postoperatively. Mortality was 0.4%. There were 29 major complications (6.4%) in 22 patients (4.8%) and 51 minor complications (11.2%). Reoperations were performed on 8 patients (1.7%). Twenty patients (4.4%) were readmitted to the hospital. Mean postoperative BMI was 25.8 +/- 3.5 kg/m(2). Mean fasting plasma glucose decreased from 198 +/- 69 to 128 +/- 67 mg/dl and mean postprandial plasma glucose decreased from 262 +/- 101 to 136 +/- 43 mg/dl. Conclusions The laparoscopic ileal interposition associated with a sleeve gastrectomy was considered a safe operation with low rates of morbidity and mortality in a diabetic population with BMI < 35. An early control of postprandial glycemia was observed.

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The classification rules of linear discriminant analysis are defined by the true mean vectors and the common covariance matrix of the populations from which the data come. Because these true parameters are generally unknown, they are commonly estimated by the sample mean vector and covariance matrix of the data in a training sample randomly drawn from each population. However, these sample statistics are notoriously susceptible to contamination by outliers, a problem compounded by the fact that the outliers may be invisible to conventional diagnostics. High-breakdown estimation is a procedure designed to remove this cause for concern by producing estimates that are immune to serious distortion by a minority of outliers, regardless of their severity. In this article we motivate and develop a high-breakdown criterion for linear discriminant analysis and give an algorithm for its implementation. The procedure is intended to supplement rather than replace the usual sample-moment methodology of discriminant analysis either by providing indications that the dataset is not seriously affected by outliers (supporting the usual analysis) or by identifying apparently aberrant points and giving resistant estimators that are not affected by them.

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Genetic population structure in the catadromous Australian bass Macquaria novemaculeata was investigated using samples from four locations spanning 600 km along the eastern Australian coastline. Both allozymes and mtDNA control region sequences were examined. Population subdivision estimates based on allozymes revealed low levels of population structuring (G(st)=0.043, P<0.05). However, mtDNA indicated moderate levels of geographic population structure (G(st)=0.146, P<0.01). Phylogenetic analysis of mtDNA control region sequences (mean sequence divergence 1.9%) indicated little phylogeographic structuring. Results suggested that genotypic variation within each river population, while bring affected primarily by genetic drift, was also prevented from more significant divergence by homogenizing levels of gene flow-synonymous with a one-dimensional stepping-stone model of population structure. The catadromous life history of Macquaria novemaculeata was considered to br influential on the pattern of population structure displayed. Results were compared to the few population genetic studies involving catadromous fishes, indicating that catadromy alone is unlikely to be a good predictor of population structure. A more comprehensive suite of biological characteristics than simple life-history traits must be considered fully to allow reliable predictive models of population structure to be formulated. (C) 1997 The Fisheries Society of the British Isles.

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To determine reference values for tissue Doppler imaging (TDI) and pulsed Doppler echocardiography for left ventricular diastolic function analysis in a healthy Brazilian adult population. Observations were based on a randomly selected healthy population from the city of Vitoria, Espirito Santo, Brazil. Healthy volunteers (n = 275, 61.7% women) without prior histories of cardiovascular disease underwent transthoracic echocardiography. We analyzed 175 individuals by TDI and evaluated mitral annulus E`- and A`-waves from the septum (S) and lateral wall (L) to calculate E`/A` ratios. Using pulsed Doppler echocardiography, we further analyzed the mitral E- and A-waves, E/A ratios, isovolumetric relaxation times (IRTs), and deceleration times (DTs) of 275 individuals. Pulsed Doppler mitral inflow mean values for men were as follows: E-wave: 71 +/- 16 cm/sec, A-wave: 68 +/- 15 cm/sec, IRT: 74.8 +/- 9.2 ms, DT: 206 +/- 32.3 ms, E/A ratio: 1.1 +/- 0.3. Pulsed Doppler mitral inflow mean values for women were as follows: E-wave: 76 +/- 17, A-wave: 69 +/- 14 cm/sec, IRT: 71.2 +/- 10.5 ms, DT: 197 +/- 33.3 ms, E/A ratio: 1.1 +/- 0.3. IRT and DT values were higher in men than in women (P = 0.04 and P = 0.007, respectively). TDI values in men were as follows: E`S: 11 +/- 3 cm/sec, A`S: 13 +/- 2 cm/sec, E`S/A`S: 0.89 +/- 0.2, E`L: 14 +/- 3 cm/sec, A`L: 14 +/- 2 cm/sec, E`L/A`L: 1.1 +/- 0.4. E-wave/ E`S ratio: 6.9 +/- 2.2; E-wave / E`L ratio: 4.9 +/- 1.7. In this study, we determined pulsed Doppler and TDI derived parameters for left ventricular diastolic function in a large sample of healthy Brazilian adults. (Echocardiography 2010;27:777-782).