The evaluation of CloudSat and CALIPSO ice microphysical products using ground-based cloud radar and lidar observations

In this paper, the statistical properties of tropical ice clouds (ice water content, visible extinction, effective radius, and total number concentration) derived from 3 yr of ground-based radar–lidar retrievals from the U.S. Department of Energy Atmospheric Radiation Measurement Climate Research Facility in Darwin, Australia, are compared with the same properties derived using the official CloudSat microphysical retrieval methods and from a simpler statistical method using radar reflectivity and air temperature. It is shown that the two official CloudSat microphysical products (2B-CWC-RO and 2B-CWC-RVOD) are statistically virtually identical. The comparison with the ground-based radar–lidar retrievals shows that all satellite methods produce ice water contents and extinctions in a much narrower range than the ground-based method and overestimate the mean vertical profiles of microphysical parameters below 10-km height by over a factor of 2. Better agreements are obtained above 10-km height. Ways to improve these estimates are suggested in this study. Effective radii retrievals from the standard CloudSat algorithms are characterized by a large positive bias of 8–12 μm. A sensitivity test shows that in response to such a bias the cloud longwave forcing is increased from 44.6 to 46.9 W m−2 (implying an error of about 5%), whereas the negative cloud shortwave forcing is increased from −81.6 to −82.8 W m−2. Further analysis reveals that these modest effects (although not insignificant) can be much larger for optically thick clouds. The statistical method using CloudSat reflectivities and air temperature was found to produce inaccurate mean vertical profiles and probability distribution functions of effective radius. This study also shows that the retrieval of the total number concentration needs to be improved in the official CloudSat microphysical methods prior to a quantitative use for the characterization of tropical ice clouds. Finally, the statistical relationship used to produce ice water content from extinction and air temperature obtained by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite is evaluated for tropical ice clouds. It is suggested that the CALIPSO ice water content retrieval is robust for tropical ice clouds, but that the temperature dependence of the statistical relationship used should be slightly refined to better reproduce the radar–lidar retrievals.

Quantitative precipitation estimation over ocean using Bayesian approach from microwave observations during the typhoon season

We have developed a new Bayesian approach to retrieve oceanic rain rate from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), with an emphasis on typhoon cases in the West Pacific. Retrieved rain rates are validated with measurements of rain gauges located on Japanese islands. To demonstrate improvement, retrievals are also compared with those from the TRMM/Precipitation Radar (PR), the Goddard Profiling Algorithm (GPROF), and a multi-channel linear regression statistical method (MLRS). We have found that qualitatively, all methods retrieved similar horizontal distributions in terms of locations of eyes and rain bands of typhoons. Quantitatively, our new Bayesian retrievals have the best linearity and the smallest root mean square (RMS) error against rain gauge data for 16 typhoon overpasses in 2004. The correlation coefficient and RMS of our retrievals are 0.95 and ~2 mm hr-1, respectively. In particular, at heavy rain rates, our Bayesian retrievals outperform those retrieved from GPROF and MLRS. Overall, the new Bayesian approach accurately retrieves surface rain rate for typhoon cases. Accurate rain rate estimates from this method can be assimilated in models to improve forecast and prevent potential damages in Taiwan during typhoon seasons.

Assessment of inter-examiner agreement and variability in the manual classification of auditory brainstem response

Abstract Background: The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behaviour, though its interpretation has a subjective nature because of the manual process employed in its study and the clinical experience required for its analysis. When analysing the ABR, clinicians are often interested in the identification of ABR signal components referred to as Jewett waves. In particular, the detection and study of the time when these waves occur (i.e., the wave latency) is a practical tool for the diagnosis of disorders affecting the auditory system. Significant differences in inter-examiner results may lead to completely distinct clinical interpretations of the state of the auditory system. In this context, the aim of this research was to evaluate the inter-examiner agreement and variability in the manual classification of ABR. Methods: A total of 160 ABR data samples were collected, for four different stimulus intensity (80dBHL, 60dBHL, 40dBHL and 20dBHL), from 10 normal-hearing subjects (5 men and 5 women, from 20 to 52 years). Four examiners with expertise in the manual classification of ABR components participated in the study. The Bland-Altman statistical method was employed for the assessment of inter-examiner agreement and variability. The mean, standard deviation and error for the bias, which is the difference between examiners’ annotations, were estimated for each pair of examiners. Scatter plots and histograms were employed for data visualization and analysis. Results: In most comparisons the differences between examiner’s annotations were below 0.1 ms, which is clinically acceptable. In four cases, it was found a large error and standard deviation (>0.1 ms) that indicate the presence of outliers and thus, discrepancies between examiners. Conclusions: Our results quantify the inter-examiner agreement and variability of the manual analysis of ABR data, and they also allows for the determination of different patterns of manual ABR analysis.

Exploiting satellite-based rainfall for weather index insurance: the challenges of spatial and temporal aggregation

Lack of access to insurance exacerbates the impact of climate variability on smallholder famers in Africa. Unlike traditional insurance, which compensates proven agricultural losses, weather index insurance (WII) pays out in the event that a weather index is breached. In principle, WII could be provided to farmers throughout Africa. There are two data-related hurdles to this. First, most farmers do not live close enough to a rain gauge with sufficiently long record of observations. Second, mismatches between weather indices and yield may expose farmers to uncompensated losses, and insurers to unfair payouts – a phenomenon known as basis risk. In essence, basis risk results from complexities in the progression from meteorological drought (rainfall deficit) to agricultural drought (low soil moisture). In this study, we use a land-surface model to describe the transition from meteorological to agricultural drought. We demonstrate that spatial and temporal aggregation of rainfall results in a clearer link with soil moisture, and hence a reduction in basis risk. We then use an advanced statistical method to show how optimal aggregation of satellite-based rainfall estimates can reduce basis risk, enabling remotely sensed data to be utilized robustly for WII.

Balanced polymorphism in bottlenecked populations: The case of the CCR5 5 ` cis-regulatory region in Amazonian Amerindians

The 5` cis-regulatory region of the CCR5 gene exhibits a strong signature of balancing selection in several human populations. Here we analyze the polymorphism of this region in Amerindians from Amazonia, who have a complex demographic history, including recent bottlenecks that are known to reduce genetic variability. Amerindians show high nucleotide diversity (pi = 0.27%) and significantly positive Tajima`s D, and carry haplotypes associated with weak and strong gene expression. To evaluate whether these signatures of balancing selection could be explained by demography, we perform neutrality tests based on empiric and simulated data. The observed Tajima`s D was higher than that of other world populations: higher than that found for 18 noncoding regions of South Amerindians, and higher than 99.6% of simulated genealogies, which assume nonequilibrium conditions. Moreover, comparing Amerindians and Asians, the Fst for CCR5 cis-regulatory region was unusually low, in relation to neutral markers. These findings indicate that, despite their complex demographic history, South Amerindians carry a detectable signature of selection on the CCR5 cis-regulatory region. (C) 2010 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

The genetic effects of Late Quaternary climatic changes over a tropical latitudinal gradient: diversification of an Atlantic Forest passerine

The increase in biodiversity from high to low latitudes is a widely recognized biogeographical pattern. According to the latitudinal gradient hypothesis (LGH), this pattern was shaped by differential effects of Late Quaternary climatic changes across a latitudinal gradient. Here, we evaluate the effects of climatic changes across a tropical latitudinal gradient and its implications to diversification of an Atlantic Forest (AF) endemic passerine. We studied the intraspecific diversification and historical demography of Sclerurus scansor, based on mitochondrial (ND2, ND3 and cytb) and nuclear (FIB7) gene sequences. Phylogenetic analyses recovered three well-supported clades associated with distinct latitudinal zones. Coalescent-based methods were applied to estimate divergence times and changes in effective population sizes. Estimates of divergence times indicate that intraspecific diversification took place during Middle-Late Pleistocene. Distinct demographic scenarios were identified, with the southern lineage exhibiting a clear signature of demographic expansion, while the central one remained more stable. The northern lineage, contrasting with LGH predictions, exhibited a clear sign of a recent bottleneck. Our results suggest that different AF regions reacted distinctly, even in opposite ways, under the same climatic period, producing simultaneously favourable scenarios for isolation and contact among populations.

Estimation of genetic variance for macro- and micro-environmental sensitivity using double hierarchical generalized linear models

Background: Genetic variation for environmental sensitivity indicates that animals are genetically different in their response to environmental factors. Environmental factors are either identifiable (e.g. temperature) and called macro-environmental or unknown and called micro-environmental. The objectives of this study were to develop a statistical method to estimate genetic parameters for macro- and micro-environmental sensitivities simultaneously, to investigate bias and precision of resulting estimates of genetic parameters and to develop and evaluate use of Akaike’s information criterion using h-likelihood to select the best fitting model. Methods: We assumed that genetic variation in macro- and micro-environmental sensitivities is expressed as genetic variance in the slope of a linear reaction norm and environmental variance, respectively. A reaction norm model to estimate genetic variance for macro-environmental sensitivity was combined with a structural model for residual variance to estimate genetic variance for micro-environmental sensitivity using a double hierarchical generalized linear model in ASReml. Akaike’s information criterion was constructed as model selection criterion using approximated h-likelihood. Populations of sires with large half-sib offspring groups were simulated to investigate bias and precision of estimated genetic parameters. Results: Designs with 100 sires, each with at least 100 offspring, are required to have standard deviations of estimated variances lower than 50% of the true value. When the number of offspring increased, standard deviations of estimates across replicates decreased substantially, especially for genetic variances of macro- and micro-environmental sensitivities. Standard deviations of estimated genetic correlations across replicates were quite large (between 0.1 and 0.4), especially when sires had few offspring. Practically, no bias was observed for estimates of any of the parameters. Using Akaike’s information criterion the true genetic model was selected as the best statistical model in at least 90% of 100 replicates when the number of offspring per sire was 100. Application of the model to lactation milk yield in dairy cattle showed that genetic variance for micro- and macro-environmental sensitivities existed. Conclusion: The algorithm and model selection criterion presented here can contribute to better understand genetic control of macro- and micro-environmental sensitivities. Designs or datasets should have at least 100 sires each with 100 offspring.

Decision Tree Classification Model In Water Supply Network

With the service life of water supply network (WSN) growth, the growing phenomenon of aging pipe network has become exceedingly serious. As urban water supply network is hidden underground asset, it is difficult for monitoring staff to make a direct classification towards the faults of pipe network by means of the modern detecting technology. In this paper, based on the basic property data (e.g. diameter, material, pressure, distance to pump, distance to tank, load, etc.) of water supply network, decision tree algorithm (C4.5) has been carried out to classify the specific situation of water supply pipeline. Part of the historical data was used to establish a decision tree classification model, and the remaining historical data was used to validate this established model. Adopting statistical methods were used to access the decision tree model including basic statistical method, Receiver Operating Characteristic (ROC) and Recall-Precision Curves (RPC). These methods has been successfully used to assess the accuracy of this established classification model of water pipe network. The purpose of classification model was to classify the specific condition of water pipe network. It is important to maintain the pipeline according to the classification results including asset unserviceable (AU), near perfect condition (NPC) and serious deterioration (SD). Finally, this research focused on pipe classification which plays a significant role in maintaining water supply networks in the future.

Programa PNAD: uma construção científica

Estudo sobre o processo de revisão dos parâmetros conceituais e metodológicos norteadores da Pesquisa Nacional por Amostra de Domicilios - PNAD, da Fundação Instituto Brasileiro de Geografia e Estatistica IBGE, abrangendo o periodo de 1989 a 1992. Objetiva-se mostrar o processo de produção estatistica, bem como compreender as relações entre objeto, teoria e método em investigações voltadas para a mensuração do real. A luz de reflexões sobre a construção do conhecimento cientifico e o papel do método no processo de pesquisa, discute-se a especificidade do método estatistico. Os resultados indicam que o processo de construção da PNAD se afirma como um fazer cientifico.

A avaliação institucional docente e seus resultados como fonte de informações à gestão do ensino superior: um estudo de caso no curso de administração da Faculdade do Pará.

Esta dissertação foi desenvolvida no curso de Administração de instituição de ensino superior, na cidade de Belém, com o intuito de compreender as principais variáveis que envolvem a avaliação institucional docente. Motivada principalmente pela preocupação com a qualidade do ensino atualmente ofertado em todo o país e buscando entender de que forma a avaliação institucional docente pode servir como fonte de informações para a tomada de decisão por parte da gestão dos cursos. Para tanto, foi feita uma pesquisa descritiva do tipo estudo de caso com abordagem quantitativa, por meio de entrevistas estruturadas, aplicadas aos alunos e a seus respectivos professores Administradores, com a utilização do método estatístico multivariado Análise de Correspondência para confrontação dos dados coletados. Com o suporte teórico do referencial selecionado de diversos autores, os resultados possibilitaram identificar, a partir do cruzamento da avaliação institucional docente realizada pelos alunos e da auto-avaliação respondida pelos professores, seis perguntas passíveis de conclusões, gerando informações importantes para a coordenação do curso em questão. Portanto, avaliar os caminhos percorridos visa uma pequena contribuição na transformação do processo de avaliação docente em processo cada vez mais respeitado e atualizado de acordo com o novo contexto e exigências organizacionais, governamentais e mercadológicas, na medida em que corresponde à importante fonte de medição e informações para tomadas de decisão por parte dos gestores universitários.

A evolução das práticas de governança corporativa nas empresas brasileiras de capital aberto

O objetivo deste trabalho é avaliar se houve evolução nas práticas de governança corporativa entre os anos de 2005 a 2012 nas empresas brasileiras que abriram capital entre 2004 e 2006, e se esta evolução ocorreu no sentido de melhoria das práticas de governança. Busca-se também entender se esta evolução ocorreu continuamente em todo o período estudado ou se somente nos primeiros anos após seu IPO. Também busca-se compreender se a evolução ocorreu somente nos requisitos mandatórios por lei ou se houve uma real mudança de cultura nas empresas após abrirem seu capital. Para mensurar a qualidade das práticas de governança foi utilizado o Corporate Governance Index – CGI desenvolvido por Leal e Carvalhal-da-Silva (2007) para avaliar as práticas de governança em empresas brasileiras. O índice é composto de 24 questões binárias, e considera-se uma evolução nas práticas quanto mais o índice da empresa se aproxima dos 24 pontos. O índice foi calculado ano a ano para o período e empresas estudadas. Em seguida, o índice foi dividido em duas partes, questões diretamente relacionadas a leis e regulamentações e questões não diretamente relacionadas a leis e regulamentações. Utilizando os testes estatísticos T-student e W de Kendall, comprovou-se estatisticamente que houve evolução nas práticas de governança corporativa entre os anos de 2005 a 2012, entretanto, prova-se estatisticamente que esta melhora está concentrada no período de 2005 a 2008, sendo que não foi constatada uma alteração significativa nas práticas no período de 2009 a 2012. Identificou-se também que houve uma evolução positiva nas práticas de governança não diretamente relacionadas a leis e regulamentações entre os anos de 2005 a 2012, entretanto, quando retira-se deste teste as questões que foram indiretamente impactadas por mudanças nas instruções da CVM que ocorreram no período, encontra-se uma piora nas práticas de governança entre 2005 e 2012. Estes resultados sugerem que as empresas estão trabalhando em um movimento de “check the box” das boas práticas de governança, cumprindo o que é mandatório por lei e regulamentações, e questiona se as evoluções de leis, regulamentações e códigos de boas práticas de governança corporativa no Brasil estão cumprindo o seu objetivo final de desenvolver uma cultura de boa governança nas empresas brasileiras.

The failure of early-stage technology startups in Brazil: a study about the contributing factors to the early-death of startups between 2009 and 2014 in Southeastern Brazil

This research aimed to find out which are the main factors that lead technology startups to fail. The study focused on companies located in the Southeast region of Brazil that operated between 2009 and 2014. In the beginning, a review of the literature was done to have a better understanding of basic concepts of entrepreneurship as well as modern techniques for developing entrepreneurship. Furthermore, an analysis of the entrepreneurial scenario in Brazil, with a focus on the Southeast, was also done. After this phase, the qualitative study began, in which 24 specialists from startups were interviewed and asked about which factors were crucial in leading a technology startup to fail. After analyzing the results, four main factors were identified and these factors were validated through a quantitative survey. A questionnaire was then formulated based on the answers from the respondents and distributed to founders and executives of startups, which both failed and succeeded. The questionnaire was answered by 56 companies and their answers were treated with the factor analysis statistical method to check the validity of the questionnaire. Finally, the logistical regression method was used to know the extent to which the factors led to the startups’ failure. In the end, the results obtained suggest that the most significant factor that leads technology startups in southeastern Brazil to fail are problems with interpersonal relationship between partners or investors.

Qualidade do gasto público em educação para os municípios da região metropolitana de Natal-2007

The aim of this thesis is to evaluate the quality of public spending on education for the municipalities of the Metropolitan Region of Natal (RMN) in 2009 by use of two theories: The Theory of Welfare (Welfare State) and the Public Choice Theory (TEP), both important to understand the relationship between education and economics. The study also uses principles of microeconomics and public sector economics to get a better idea of the role of education in economy and society. It describes the development of the educational policy in Brazil from 1988 to the Federal Constitution of 2010, following the major changes in basic education during each government. The characteristics of the RMN municipalities were illustrated with socioeconomic indicators, while educational indicators were used to characterize each municipality regarding education. The model used in this study was developed by Bertê, Brunet and Borges, the data was collected on the back of the School Census 2009 and the Brazil Exam 2009 and it was processed quantitavely in the Information System on Public Budgets in Education (SIOPE) by use of the statistical method called standardized score of the normal cumulative distribution function. The quality of public spending on education is the result of the relation between performance indicator ratio and expense ratio. For the qualitative analysis of results, the criteria of efficiency, efficacy and effectiveness were used. The study found that municipalities with higher expenses showed a worse quality of spending and failed to convert the expenditure incurred into performance, thus confirming ineffectiveness

Medição de satisfação e fidelidade do cliente :um estudo com pacientes de clínica particular

This Thesis deals with a study on customer satisfaction and loyalty measurement focusing on a model of factors antecedents of customer satisfaction and loyalty. The model is based on a Satisfaction Index model adopted in Norway developed by Johnson et al.(2001) and the service quality drivers from the literature. It is surveyed a sample of 130 patients of a gynecology clinical. It is used a multiple regression analysis as the main statistical method in order to verify the factors affecting satisfaction and loyalty. The main findings are that the quality model explain 54% of the satisfaction but the whole model explain only 31% of the loyalty. Although the results are consistent with the literature in term of quality as the main driver of the satisfaction and that the satisfaction is not only one factor to explain loyalty, both the quality model to satisfaction and the factors model affecting loyalty should be improved to explain better the satisfaction and loyalty in health care service

A gestão da qualidade nos cursos de graduação a distância da UFRN/SEDIS : a percepção dos discentes

This dissertation has as objective at analyzing the students' perception about the quality of graduate courses distance of the Federal University of Rio Grande do Norte, which was motivated by the following research problem: the perception that graduate students of the distance of the UFRN have on the quality of the undergraduate? To this end, we sought to gather evidence for a satisfactory approach that addresses the complexity of the subject studied: quality management, distance learning and quality in the Higher Education Institutions. We chose to adopt as a research method, case study on the procedure of the research, exploratory research-descriptive about the objective and quantitative research when tackling the problem. The object of the study were six graduate courses distance UFRN/SEDIS, having as target the students of the courses. The sample was calculated using the Stratified sampling on which 217 students, the courses surveyed were selected. The survey instrument consisted of 21 structured questions, of which seven questions designed to identify the profile of students, seven issues of perceptions (manifest variables) on quality management in distance learning, where students have given values (responses) for 24 statements (which address the central theme of this dissertation) composite based on a 5-point Likert s scale, and six questions about general characteristics that may interfere with students' perception about the quality. Was used as statistical method (data analysis), descriptive statistics and exploratory factor analysis. The results show the identification of four latent factors (obtained by exploratory factor analysis), namely: (1) infrastructure and management - polo presence, (2) teaching-learning processes, (3) communication tools and integration; (4) tutors. We also observed that aspects related to infrastructure and management at the pole face had the lowest score among the factors observed, requiring special attention by the education institution. On the other hand, teachers and teaching learning processes were the items with better performance in the perception of students. It is concluded that the perception of students in relation to quality in distance education courses, the median is trending positive perception, ie the perception of overall quality of the courses is not assertive and unison, but tends to positive perception. Thus, the results, it is expected that the managers of the institution to focus attention on critical points in order to minimize them (or eliminate them) and maximize the positive aspects that are perceived by the students