Aplicação de SIG no Processamento do Inventário Florestal Nacional – Cabo Verde

Cabo Verde desde do século passado tem envidado esforço na florestação, sobretudo depois de 1975 para atenuar os efeitos da seca e da desertificação criando deste modo grandes áreas arborizadas. Entretanto, à medida que os recursos florestais foram sendo criados, a problemática da sua avaliação e da sua gestão sustentável, passaram a merecer maior atenção das autoridades nacionais. A lei florestal, promulgada em 1998 define como uma das atribuições e acções do Estado, através dos serviços florestais, a elaboração dos planos de gestão das zonas florestais. Este plano de gestão implica a análise e a apreciação de dados concretos e actualizados sobre a situação real das zonas florestais, sendo possível apenas através do inventário florestal nacional (IFN). Neste trabalho é proposta uma metodologia de processamento do IFN em que se utilizam as potencialidades dos Sistemas de Informação Geográfica (SIG). Foram utilizados para este trabalho os programas: ArcGis 9.1, para produção cartográfica, geoprocessamento e análise espacial e o Field-Map 8.1 para a classificação de ortofotos num esquema de classificação hierárquica, em cinco níveis, adaptado a Cabo Verde (classes de uso do solo adoptado ao esquema de classificação do território europeu – CORINE Land Cover e da Organização das Nações Unidas para a Agricultura e Alimentação (FAO). Os dados utilizados foram compilados no âmbito do projecto do inventário florestal. Os resultados obtidos, para a Ilha de Santiago, constituem uma base cartográfica para o IFN com diversos temas cartográficos, nomeadamente, mapas das zonas florestadas, mapas de ocupação do solo e mapas de amostras inventariáveis cuja metodologia de elaboração poderá ser facilmente replicada para as restantes ilhas do arquipélago.

A simple permutation test for clusteredness

Hierarchical clustering is a popular method for finding structure in multivariate data,resulting in a binary tree constructed on the particular objects of the study, usually samplingunits. The user faces the decision where to cut the binary tree in order to determine the numberof clusters to interpret and there are various ad hoc rules for arriving at a decision. A simplepermutation test is presented that diagnoses whether non-random levels of clustering are presentin the set of objects and, if so, indicates the specific level at which the tree can be cut. The test isvalidated against random matrices to verify the type I error probability and a power study isperformed on data sets with known clusteredness to study the type II error.

Appropriateness of respiratory care: evidence-based guidelines.

PRINCIPLES: Respiratory care is universally recognised as useful, but its indications and practice vary markedly. In order to improve the appropriateness of respiratory care in our hospital, we developed evidence-based local guidelines in a collaborative effort involving physiotherapists, physicians and health service researchers. METHODS: Recommendations were developed using the standardised RAND appropriateness method. A literature search was conducted based on terms associated with guidelines and with respiratory care. A working group prepared proposals for recommendations which were then independently rated by a multidisciplinary expert panel. All recommendations were then discussed in common and indications for procedures were rated confidentially a second time by the experts. The recommendations were then formulated on the basis of the level of evidence in the literature and on the consensus among these experts. RESULTS: Recommendations were formulated for the following procedures: non-invasive ventilation, continuous positive airway pressure, intermittent positive pressure breathing, intrapulmonary percussive ventilation, mechanical insufflation-exsufflation, incentive spirometry, positive expiratory pressure, nasotracheal suctioning and non-instrumental airway clearance techniques. Each recommendation referred to a particular medical condition and was assigned to a hierarchical category based on the quality of the evidence from the literature supporting the recommendation and on the consensus among the experts. CONCLUSION: Despite a marked heterogeneity of scientific evidence, the method used allowed us to develop commonly agreed local guidelines for respiratory care. In addition, this work fostered a closer relationship between physiotherapists and physicians in our institution.

Testing demographic models of effective population size.

Due to practical difficulties in obtaining direct genetic estimates of effective sizes, conservation biologists have to rely on so-called 'demographic models' which combine life-history and mating-system parameters with F-statistics in order to produce indirect estimates of effective sizes. However, for the same practical reasons that prevent direct genetic estimates, the accuracy of demographic models is difficult to evaluate. Here we use individual-based, genetically explicit computer simulations in order to investigate the accuracy of two such demographic models aimed at investigating the hierarchical structure of populations. We show that, by and large, these models provide good estimates under a wide range of mating systems and dispersal patterns. However, one of the models should be avoided whenever the focal species' breeding system approaches monogamy with no sex bias in dispersal or when a substructure within social groups is suspected because effective sizes may then be strongly overestimated. The timing during the life cycle at which F-statistics are evaluated is also of crucial importance and attention should be paid to it when designing field sampling since different demographic models assume different timings. Our study shows that individual-based, genetically explicit models provide a promising way of evaluating the accuracy of demographic models of effective size and delineate their field of applicability.

Further insights on the French WISC-IV factor structure through Bayesian structural equation modeling

The interpretation of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) is based on a 4-factor model, which is only partially compatible with the mainstream Cattell-Horn-Carroll (CHC) model of intelligence measurement. The structure of cognitive batteries is frequently analyzed via exploratory factor analysis and/or confirmatory factor analysis. With classical confirmatory factor analysis, almost all crossloadings between latent variables and measures are fixed to zero in order to allow the model to be identified. However, inappropriate zero cross-loadings can contribute to poor model fit, distorted factors, and biased factor correlations; most important, they do not necessarily faithfully reflect theory. To deal with these methodological and theoretical limitations, we used a new statistical approach, Bayesian structural equation modeling (BSEM), among a sample of 249 French-speaking Swiss children (8-12 years). With BSEM, zero-fixed cross-loadings between latent variables and measures are replaced by approximate zeros, based on informative, small-variance priors. Results indicated that a direct hierarchical CHC-based model with 5 factors plus a general intelligence factor better represented the structure of the WISC-IV than did the 4-factor structure and the higher order models. Because a direct hierarchical CHC model was more adequate, it was concluded that the general factor should be considered as a breadth rather than a superordinate factor. Because it was possible for us to estimate the influence of each of the latent variables on the 15 subtest scores, BSEM allowed improvement of the understanding of the structure of intelligence tests and the clinical interpretation of the subtest scores.

A multilevel analysis on the determinants of regional health care expenditure. A note

We apply a multilevel hierarchical model to explore whether anaggregation fallacy exists in estimating the income elasticity of healthexpenditure by ignoring the regional composition of national healthexpenditure figures. We use data for 110 regions in eight OECD countriesin 1997: Australia, Canada, France, Germany, Italy, Spain, Sweden andUnited Kingdom. In doing this we have tried to identify two sources ofrandom variation: within countries and between-countries. Our resultsshow that: 1- Variability between countries amounts to (SD) 0.5433, andjust 13% of that can be attributed to income elasticity and the remaining87% to autonomous health expenditure; 2- Within countries, variabilityamounts to (SD) 1.0249; and 3- The intra-class correlation is 0.5300. Weconclude that we have to take into account the degree of fiscaldecentralisation within countries in estimating income elasticity ofhealth expenditure. Two reasons lie behind this: a) where there isdecentralisation to the regions, policies aimed at emulating diversitytend to increase national health care expenditure; and b) without fiscaldecentralisation, central monitoring of finance tends to reduce regionaldiversity and therefore decrease national health expenditure.

Why England? Demand, growth and inequality during the Industrial Revolution

Why was England first? And why Europe? We present a probabilistic model that builds on big-push models by Murphy, Shleifer and Vishny (1989), combined with hierarchical preferences. The interaction of exogenous demographic factors (in particular the English low-pressure variant of the European marriage pattern)and redistributive institutions such as the old Poor Law combined to make an Industrial Revolution more likely. Essentially, industrialization is the result of having a critical mass of consumers that is rich enough to afford (potentially) mass-produced goods. Our model is then calibrated to match the main characteristics of the English economy in 1750 and the observed transition until 1850.This allows us to address explicitly one of the key features of the British IndustrialRevolution unearthed by economic historians over the last three decades the slowness of productivity and output change. In our calibration, we find that the probability of Britain industrializing is 5 times larger than France s. Contrary to the recent argument by Pomeranz, China in the 18th century had essentially no chance to industrialize at all. This difference is decomposed into a demographic and a policy component, with the former being far more important than the latter.

Striking immunodominance hierarchy of naturally occurring CD8+ and CD4+ T cell responses to tumor antigen NY-ESO-1.

Immunodominance has been well-demonstrated in many antiviral and antibacterial systems, but much less so in the setting of immune responses against cancer. Tumor Ag-specific CD8+ T cells keep cancer cells in check via immunosurveillance and shape tumor development through immunoediting. Because most tumor Ags are self Ags, the breadth and depth of antitumor immune responses have not been well-appreciated. To design and develop antitumor vaccines, it is important to understand the immunodominance hierarchy and its underlying mechanisms, and to identify the most immunodominant tumor Ag-specific T cells. We have comprehensively analyzed spontaneous cellular immune responses of one individual and show that multiple tumor Ags are targeted by the patient's immune system, especially the "cancer-testis" tumor Ag NY-ESO-1. The pattern of anti-NY-ESO-1 T cell responses in this patient closely resembles the classical broad yet hierarchical antiviral immunity and was confirmed in a second subject.

Driver scheduling problem modelling

The Drivers Scheduling Problem (DSP) consists of selecting a set of duties for vehicle drivers, for example buses, trains, plane or boat drivers or pilots, for the transportation of passengers or goods. This is a complex problem because it involves several constraints related to labour and company rules and can also present different evaluation criteria and objectives. Being able to develop an adequate model for this problem that can represent the real problem as close as possible is an important research area.The main objective of this research work is to present new mathematical models to the DSP problem that represent all the complexity of the drivers scheduling problem, and also demonstrate that the solutions of these models can be easily implemented in real situations. This issue has been recognized by several authors and as important problem in Public Transportation. The most well-known and general formulation for the DSP is a Set Partition/Set Covering Model (SPP/SCP). However, to a large extend these models simplify some of the specific business aspects and issues of real problems. This makes it difficult to use these models as automatic planning systems because the schedules obtained must be modified manually to be implemented in real situations. Based on extensive passenger transportation experience in bus companies in Portugal, we propose new alternative models to formulate the DSP problem. These models are also based on Set Partitioning/Covering Models; however, they take into account the bus operator issues and the perspective opinions and environment of the user.We follow the steps of the Operations Research Methodology which consist of: Identify the Problem; Understand the System; Formulate a Mathematical Model; Verify the Model; Select the Best Alternative; Present the Results of theAnalysis and Implement and Evaluate. All the processes are done with close participation and involvement of the final users from different transportation companies. The planner s opinion and main criticisms are used to improve the proposed model in a continuous enrichment process. The final objective is to have a model that can be incorporated into an information system to be used as an automatic tool to produce driver schedules. Therefore, the criteria for evaluating the models is the capacity to generate real and useful schedules that can be implemented without many manual adjustments or modifications. We have considered the following as measures of the quality of the model: simplicity, solution quality and applicability. We tested the alternative models with a set of real data obtained from several different transportation companies and analyzed the optimal schedules obtained with respect to the applicability of the solution to the real situation. To do this, the schedules were analyzed by the planners to determine their quality and applicability. The main result of this work is the proposition of new mathematical models for the DSP that better represent the realities of the passenger transportation operators and lead to better schedules that can be implemented directly in real situations.

Forecasting and turning point predictions in a Bayesian panel VAR model

We provide methods for forecasting variables and predicting turning points in panel Bayesian VARs. We specify a flexible model which accounts for both interdependencies in the cross section and time variations in the parameters. Posterior distributions for the parameters are obtained for a particular type of diffuse, for Minnesota-type and for hierarchical priors. Formulas for multistep, multiunit point and average forecasts are provided. An application to the problem of forecasting the growth rate of output and of predicting turning points in the G-7 illustrates the approach. A comparison with alternative forecasting methods is also provided.

Increasing prevalence of gastroschisis in Europe 1980-2002: a phenomenon restricted to younger mothers?

Gastroschisis is an abdominal wall defect more prevalent in offspring of young mothers. It is known to be increasing in prevalence despite the general decrease in the proportion of births to young European women. We investigated whether the increase in prevalence was restricted to the high-risk younger mothers. We analysed 936 cases of gastroschisis from 25 population-based registries in 15 European countries, 1980-2002. We fitted a Bayesian Hierarchical Model which allowed us to estimate trend, to estimate which registries were significantly different from the common distribution, and to adjust simultaneously for maternal age, time (in grouped years) and the random variation between registries. The maternal age-standardised prevalence (standardised to the year 2000 European maternal age structure) increased almost fourfold from 0.54 [95% Credible Interval (CrI) 0.37, 0.75] per 10,000 births in 1980-84 to 2.12 [95% CrI 1.85, 2.40] per 10,000 births in 2000-02. The relative risk of gastroschisis for mothers <20 years of age in 1995-2002 was 7.0 [95% CrI 5.6, 8.7]. There were geographical differences within Europe, with higher rates of gastroschisis in the UK, and lower rates in Italy after adjusting for maternal age. After standardising for regional variation, our results showed that the increase in risk over time was the same for mothers of all ages--the increase for mothers <20 years was 3.96-fold compared with an increase of 3.95-fold for mothers in the other age groups. These findings indicate that the phenomenon of increasing gastroschisis prevalence is not restricted to younger mothers only.

More than one inseminated female in colonies of the independent-founding wasp Mischocyttarus cassununga von Ihering (Hymenoptera, Vespidae)

In the primitively eusocial wasps, especially Polistini and Mischocyttarini tribes, the physiological condition of each individual is strongly associated with its dominance status in the colonial hierarchy. As a rule, in independent-founding wasps, female wasps are all morphologically alike, and their role is apparently quite flexible even as adults. However, some studies have shown that differences in body size can exist between reproductive and non-reproductive females. Thus, the present study aimed at detecting differences between reproductive (inseminated) and non-reproductive (uninseminated) individuals based on morphological and physiological parameters. We tape-recorded the daily behavioural repertory of six colonies of Mischocyttarus cassununga for determining the hierarchical dominance in the field, and then collected these colonies (in different cycle stages) for measuring 13 set characters, and assessing the physiological condition of each individual by inspecting their fat bodies and ovaries. Our results revealed that inseminated and uninseminated females are not significantly different in relation to body size, in spite of first group shows higher average than second in almost all measured parts. The physiological evaluation of each individual demonstrated more than one inseminated female per colony during all stages of the colony cycle, suggesting a strategic condition of this species against difficulties (predation and parasitism of the colony) in nature.

Breeding system and genetic variance in the monogamous, semi-social shrew, Crocidura russula

The population-genetic consequences of monogamy and male philopatry (a rare breeding system in mammals) were investigated using microsatellite markers in the semisocial and anthropophilic shrew Crocidura russula. A hierarchical sampling design over a 16-km geographical transect revealed a large genetic diversity (h = 0.813) with significant differentiation among subpopulations (F-ST = 5-6%), which suggests an exchange of 4.4 migrants per generation. Demic effective-size estimates were very high, due both to this limited gene inflow and to the inner structure of subpopulations. These were made of 13-20 smaller units (breeding groups), comprising an estimate of four breeding pairs each. Members of the same breeding groups displayed significant coancestries (F-LS = 9-10%), which was essentially due to strong male kinship: syntopic males were on average related at the half-sib level. Female dispersal among breeding groups was not complete (similar to 39%), and insufficient to prevent inbreeding. From our results, the breeding strategy of C. russula seems less efficient than classical mammalian systems (polygyny and male dispersal) in disentangling coancestry from inbreeding, but more so in retaining genetic variance.

Drug utilization studies and data registries in primary care

This article reviews the methodology of the studies on drug utilization with particular emphasis on primary care. Population based studies of drug inappropriateness can be done with microdata from Health Electronic Records and e-prescriptions. Multilevel models estimate the influence of factors affecting the appropriateness of drug prescription at different hierarchical levels: patient, doctor, health care organization and regulatory environment.Work by the GIUMAP suggest that patient characteristics are the most important factor in the appropriateness of prescriptions with significant effects at the general practicioner level.

Analysis of antiviral immunity in primary and chronic infections

Several evidences in humans underscored the contribution of CD4 and CD8 T-cell responses in controlling viral and bacterial infections. However, CD4 and CD8 Τ cells have distinct and specific effector functions leading to a hierarchical importance in responding to different types of pathogens. In this context, the present work aimed to investigate distinct CD8 T-cell features potentially influencing T-cell efficacy against viral infection. To achieve this-objective, CD8 Τ cells derived from HIV-infected patients and healthy donors harbouring virus-specific immune responses or immunized with an HTV vaccine candidate were studied. In particular, we performed a comprehensive cross-sectional and longitudinal analysis to characterize the function, the phenotype and the functional avidity of HIV-specific CD8 Τ cells during acute (PHI) and chronic infection and, in particular, we investigated immunological parameters potentially associated with the functional avidity of HIV-specific CD8 Τ cells. In addition, we studied the expression pattern of co-inhibitory molecules and the influence of CD 160 on the functions of CD8 Τ cells in absence of chronic infections. From these analyses we observed that the functional avidity of HIV-specific CD8 T- cell responses was significantly lower in acute than in chronic infection, but was not different between chronic progressive and non-progressive patients. Functional avidity remained low after several years of antiretroviral therapy in PHI patients, but increased in patients experiencing a virus rebound following treatment interruption in association with a massive renewal of the global CD8 complementarity-determining region 3 of the TCR. The functional avidity was also directly associated to T-cell exhaustion. In individuals with no sign of HIV or Hepatitis A, Β or C virus infection, CD8 Τ cells expressed higher levels of co-inhibitory molecules than CD4 Τ cells and this was dependent on the stage of T-cell differentiation and activation. The expression of CD 160 impaired the proliferation capacity and IL-2 production of CD8 Τ cells and was reduced upon CD8 T-cell activation, entitling CD 160 as unique marker of CD8 T-cell exhaustion. The CD 160 blockade restored the proliferation capacity of virus-specific CD8 Τ cells providing a potential new target for immunotherapy. All together, these results expand our knowledge regarding the interplay between the immune system and the viruses. - De nombreuses études chez l'Homme ont mis en évidence la contribution des réponses cellulaires Τ CD4 et CD8 dans le contrôle des infections virales et bactériennes. En particulier, les lymphocytes Τ ont différentes fonctions effectrices spécifiques qui leur confèrent un rôle clé lors d'infections par différents pathogènes. Ce travail vise à étudier différentes caractéristiques des cellules Τ CD8 affectant l'efficacité des réponses cellulaires contre les virus. Pour atteindre cet objectif nous avons étudié les cellules Τ CD8 provenant de patients infectés par le VIH et de donneurs sains avec des réponses immunitaires naturelles ou vaccinales contre des virus. Nous avons effectué plusieurs analyses transversales et longitudinales des fonctions, du phénotype et de l'avidité fonctionnelle des lymphocytes Τ CD8 spécifiques au VIH au cours d'infections aiguës et chroniques; en particulier, nous avons étudié les paramètres immunologiques qui pourraient être associés à l'avidité fonctionnelle. De plus, nous avons investigué le profil d'expression des principales molécules co-inhibitrices et en particulier le rôle du CD 160 dans les fonctions des lymphocytes Τ CD8. Sur la base de ces analyses, nous avons constaté que l'avidité fonctionnelle des cellules Τ CD8 spécifiques au VIH était significativement plus faible lors infections aiguës que lors d'infections chroniques, mais n'était, par contre, pas différente entre les patients avec des infections chroniques progressives et non progressives. L'avidité fonctionnelle reste faible après plusieurs années de traitement antirétroviral, mais augmente chez les patients subissant un rebond viral, et donc exposés à des hautes virémies, suite à l'interruption du traitement. Cette augmentation d'avidité des lymphocytes Τ CD8, liée à un épuisement fonctionnel accru, était quantitativement directement associée à un renouvellement massif du TCR. Indépendamment de l'infection par le VIH, les cellules Τ CD8 expriment des niveaux plus élevés de molécules co-inhibitrices (PD-1, 2B4 et CD 160) par rapport aux cellules Τ CD4 et ceci dépend de leur stade de différenciation et d'activation. En particulier, CD 160 semble être un marqueur clé d'épuisement cellulaire des cellules Τ CD8, et donc une nouvelle cible potentielle pour l'immunothérapie, car a) son expression réduit la capacité proliférative et la production d'IL-2 b) CD 160 diminue suite à 1'activation et c) le blocage de CD 160 redonne la capacité proliférative aux cellules Τ CD8 spécifiques aux virus. - Le système immunitaire est un ensemble de cellules, tissus et organes indispensables pour limiter l'entrée des pathogènes à travers la peau et les muqueuses. Parmi les différentes cellules composant le système immunitaire, les cellules Τ CD4 et CD8 sont fondamentales pour le contrôle des infections virales et bactériennes. Les moyens pour combattre les différents pathogènes peuvent être cependant très variables. Les cellules Τ CD8, qui sont indispensables pour la lutte contre les virus, peuvent avoir différents niveaux de sensibilité; les cellules qui répondent à de faibles quantités d'antigène ont une forte sensibilité. Suite à une première infection virale, les cellules Τ CD8 ont une sensibilité plus faible que lors d'expositions répétées au même virus. En effet, la réexposition au pathogène induit une augmentation de sensibilité, grâce au recrutement et/ou à l'expansion de cellules Τ dotées d'une sensibilité plus élevée. Les cellules Τ CD8 avec une plus haute sensibilité semblent être caractérisées par une perte de fonctionnalité (épuisement fonctionnel associé à une haute expression de molécules dites inhibitrices). En absence d'infection, la fonction des molécules inhibitrices n'est pas encore clairement définie. Les cellules Τ CD8 montrent un niveau d'expression plus élevé de ces molécules par rapport aux cellules Τ CD4. Ceci dépend de l'état des cellules. Parmi ces molécules, le CD160 est associé à l'incapacité des cellules à proliférer et à produire de l'IL-2, une protéine importante pour la prolifération et la survie cellulaire. L'incapacité des cellules exprimant le CD 160 à proliférer en réponse à des virus peut être restaurée par le blocage fonctionnel du récepteur CD 160. Cette étude étoffe notre connaissance du rôle des cellules Τ CD8 ainsi que des conséquences induites par leur épuisement fonctionnel. Ces informations sont fondamentales pour le développement de nouvelles stratégies thérapeutiques et vaccinales.