913 resultados para grouping estimators
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In recent years, there has been an increasing number of studies on carrion fly communities due to their medical importance and as a consequence of the large number of studies on forensic entomology. Surprisingly few studies have adressed with the asynantropic flies of the Amazon, and none were done in Colombia. A faunistic study of asynantropic flies of the families Calliphoridae, Sarcophagidae, Muscidae and Fannidae in three different landscapes of the Colombian Amazon is presented, trapping effectiveness is assessed, and the first record of Mesembrinella batesi (Aldrich, 1922) and Fannia femoralis (Stein, 1897) from Colombia is reported.
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Phlebotomine sand flies are insects of medical importance. Species in the Neotropical region are highly diverse. Some of these species are considered cryptic species because of their morphological similarity between adult females of different species make identification especially difficult. The aim of this study was to analyze and describe the armature in the genital atrium (AGA) of some adult female sand flies, in order to discover new taxonomic characters that make it possible to distinguish between species that would otherwise be treated as cryptic by analysis of the AGA. The AGA of 16 Phlebotomine sand fly species are described. Distinct differences were found in relation to the shape and size of the armature, the presence or absence of spines on the armature, and the shape, size, and grouping patterns of the spines. These characters made it possible to distinguish between the species studied.
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This research aims to advance blinking detection in the context of work activity. Rather than patients having to attend a clinic, blinking videos can be acquired in a work environment, and further automatically analyzed. Therefore, this paper presents a methodology to perform the automatic detection of eye blink using consumer videos acquired with low-cost web cameras. This methodology includes the detection of the face and eyes of the recorded person, and then it analyzes the low-level features of the eye region to create a quantitative vector. Finally, this vector is classified into one of the two categories considered —open and closed eyes— by using machine learning algorithms. The effectiveness of the proposed methodology was demonstrated since it provides unbiased results with classification errors under 5%
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Dissertação de mestrado em Ciências da Comunicação (área de especialização em Publicidade e Relações Públicas)
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Dissertação de mestrado em Estatística
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ნაშრომში დამტკიცებულია აუცილებელი და საკმარისი პირობები, თუ როდის უშვებს ფიშერის სტატისტიკური სტრუქტურა პარამეტრების ძალდებულ შეფასებას.
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Similarity-based operations, similarity join, similarity grouping, data integration
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The purpose of this work was to determine the diversity and population fluctuations of calliphorid flies in the Biological Reserve of Tinguá (ReBio-Tinguá), Nova Iguaçu, state of Rio de Janeiro, Brazil and to correlate their occurrence with the environmental variables of temperature, rainfall and relative air humidity. Specimens of Diptera were collected monthly between June 2002 and January 2005 using four traps placed at four points along a trail and exposed for 48 hours. The traps were baited with sardines and the trapped insects were stored in 70% alcohol. It was collected 8,528 calliphorids, thirteen species were identified among the blowflies including Laneela nigripes Guimarães 1977, Chrysomya megacephala (Fabricius, 1794), C. albiceps (Wiedemann, 1819), C. putoria (Wiedemann, 1830), Chloroprocta idioidea (Robineau-Devoidy, 1830), Cochliomyia macellaria (Fabricius, 1775), Hemilucilia semidiaphana (Rondani, 1850), H. segmentaria (Fabricius, 1805), Lucilia eximia (Wiedemann,1819), L. cuprina (Wiedemann, 1830), Paralucilia pseudolyrcea (Mello, 1969), Mesembrinella sp. and Eumesembrinella pauciseta (Aldrich, 1922). No significant correlation was found between the abundance of blowflies and the temperature and relative air humidity. Only C. megacephala and C. albiceps showed a positive and significant correlation with rainfall. An analysis of grouping by month (UPGMA) revealed no seasonal difference in the composition of the community, indicating that the community of calliphorid flies is probably more influenced by the ecological niches occupied by each species than by the seasons of the year.
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Brazilian fauna of drosophilids has been researched in various ecosystems, but those in mangrove forests remain overlooked in Brazil and elsewhere. The present study attempts to characterise the assemblages of drosophilids of this environment, based on 28 collections taken in three mangrove areas in Santa Catarina Island, southern Brazil. The three mangroves surveyed were different in their surroundings, which varied from highly urbanised areas to conservation areas with natural vegetation. Overall, 69 species were collected, and no remarkable difference was detected in species composition and abundances or in the richness, evenness and heterogeneity between sites. The species abundance distribution observed fitted to a theoretical lognormal distribution in the three mangroves. The species richness scored and the performance of the species richness estimators showed an unexpectedly high diversity, considering the very low floristic diversity and the harsh conditions of the environment. Regarding species composition and abundances, the drosophilid mangrove assemblages were shown to be more similar to those found in open environments, with a marked dominance of exotic species. Finally, considering the apparent lack of feeding and breeding sites, we suggest that mangrove forests are acting as sink habitats for the drosophilids populations.
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A spindle-cell sarcoma (fig. 5) apparently originating from the dura (fig. 4) was found at the autopsy of a male, mulato, 17 years of age. The bones of the skull (occipital and both parietals) were penetrated and destroyed (fig. 1 and 2). The nervous tissue was not penetrated, the only change in the brain being a depressed area where the tumor was included. Metastatic nodules were found in the liver (fig. 3),hepatic lymphnodes (fig. 14), spleen (fig. 12) and suprarenal bodies (fig. 15). The structure, however, in all those different locations was that of a typical endothelioma (figs. 8, 11 and 13). The cells are of large and moderate size, of polyhedral form, with vesicular nuclei, diminutive nucleoli and clear cytoplasm. (Figs. 6 and 8). They are arranged about a central lumen which represents a rudimentary vessel (figs. 9 and 13). Other areas are composed of cells without concentric arrangement (figs. 4 and 10). In small areas, the colums of liver cells are marginated in one side by typical sinusoids, while in the other side tumor cells arranged about a narrow lumen are seen suggesting a pathological (neoplastic) sinusoid (figs. 7 and 9). The case is considered as a multiple diffuse endothelioma. The origin of the tumor is referred to the reticulo-endothelial apparatus of the liver, the spleen, the suprarenal bodies and the lymph nodes, the structure being rather uniform in those organs. In the dura, the endothelioma reproduces the structure and presents the general character of a fibroblastic sarcoma; in some places, however, the structure of endothelioma could be found (fig.6). It corresponds to the reticulo-endotheliomatosis maligna according to Puhr's grouping of progressive changes in the reticulo-endothelial apparatus which is a follows: 1. HYPERPLASTIC - 1. Mnnocytic leukemia. 2. a) Aleukemic reticulosis (Goldschmid and Isaac). b) Idiopathic sarcoma of skin (Kaposi). c) Cutaneous sarcoid (Spiegler). 3. Secretory reticulosis. a) Gaucher's disease. b) Generalized xanthomatosis. c) Spleno-hepatomegaly with lipoidic cells (Pick). II. BLASTOMATOSUS OR NEOPLASTIC - 1. Benign - a) Circumscribed tumors. a) Epulis sarcomatosa; b) Benign giant-cells sarcoma of the bone - marrow of long bones. b) Generalized brown tumors of osteitis fibrosa. 2. Malignant - a) Circumscribed haemangio - endothelioma (reticulo- endothelioma (maligum). of {liver, spleen, bone-marrow. b) Generalized haemangio-endotheliomatosis (reticulo-endotheliomatosis maligna) (Grabowski).
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The primary purpose of this exploratory empirical study is to examine the structural stability of a limited number of alternative explanatory factors of strategic change. On the basis of theoretical arguments and prior empirical evidence from two traditional perspectives, we propose an original empirical framework to analyse whether these potential explanatory factors have remained stable over time in a highly turbulent environment. This original question is explored in a particular setting: the population of Spanish private banks. The firms of this industry have experienced a high level of strategic mobility as a consequence of fundamental changes undergone in their environmental conditions over the last two decades (mainly changes related to the new banking and financial regulation process). Our results consistently support that the effect of most explanatory factors of strategic mobility considered did not remain stable over the whole period of analysis. From this point of view, the study sheds new light on major debates and dilemmas in the field of strategy regarding why firms change their competitive patterns over time and, hence, to what extent the "contextdependency" of alternative views of strategic change as their relative validation can vary over time for a given population. Methodologically, this research makes two major contributions to the study of potential determinants of strategic change. First, the definition and measurement of strategic change employing a new grouping method, the Model-based Cluster Method or MCLUST. Second, in order to asses the possible effect of determinants of strategic mobility we have controlled the non-observable heterogeneity using logistic regression models for panel data.
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Ever since the appearance of the ARCH model [Engle(1982a)], an impressive array of variance specifications belonging to the same class of models has emerged [i.e. Bollerslev's (1986) GARCH; Nelson's (1990) EGARCH]. This recent domain has achieved very successful developments. Nevertheless, several empirical studies seem to show that the performance of such models is not always appropriate [Boulier(1992)]. In this paper we propose a new specification: the Quadratic Moving Average Conditional heteroskedasticity model. Its statistical properties, such as the kurtosis and the symmetry, as well as two estimators (Method of Moments and Maximum Likelihood) are studied. Two statistical tests are presented, the first one tests for homoskedasticity and the second one, discriminates between ARCH and QMACH specification. A Monte Carlo study is presented in order to illustrate some of the theoretical results. An empirical study is undertaken for the DM-US exchange rate.
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It is well known that the culture media used in the presumptive diagnosis of suspiciuous colonies from plates inoculated with stools for isolation of enteric organisms do not always correctly indicate the major groups of enterobacteria. In an effort to obtain a medium affording more exact indications, several media (1-9) have been tested. Modifications of some of these media have also been tested with the result that a satisfactory modification of Monteverde's medium was finaly selected. This proved to be most satisfactory, affording, as a result of only one inoculation, a complete series of basic indications. The modification involves changes in the formula, in the method of preparation and in the manner of storage. The formulae are: A. Thymol blue indicator: NaOH 0.1/N .............. 34.4 ml; Thymol blue .............. 1.6 g; Water .................... 65.6 ml. B. Andrade's indicator. C. Urea and sugar solution: Urea ..................... 20 g; Lactose ................... 30 g; Sucrose ................... 30 g; Water .................... 100 ml. The mixture (C.) should be warmed slightly in order to dissolve the ingredients rapidly. Sterilise by filtration (Seitz). Keep stock in refrigeratior. The modification of Monteverde's medium is prepared in two parts. Semi-solid part - Peptone (Difco) 2.0 g; NaCl 0.5 g; Agar 0.5 g; Water 100.0 ml. Boil to dissolve the ingredients. Adjust pH with NaOH to 7.3-7.4. Boil again for precipitation. Filter through cotton. Ad indicators "A" 0.3 ml and "B" 1.0 ml. Sterilise in autoclave 115ºC, 15 minutes in amounts not higher than 200 ml. Just before using, add solution "C" asseptically in amounts of 10 ml to 200 ml of the melted semi-solid medium, maintained at 48-50ºC. Solid part - Peptone (Difco) 1.5 g; Trypticase (BBL) 0.5 g; Agar 2.0 g; Water 100,00 ml. Boil to dissolve the ingredients. Adjust pH with NaOH to 7.3-7.4. Boils again. Filter through cotton. Add indicators "A" 0.3 ml and "B" 1.0 ml; ferrous ammonium sulfate 0.02 g; sodiun thiosulfate 0.02 g. Sterilise in autoclave 115ºC, 15 minutes in amounts not higher than 200 ml. Just before using, add solution "C" asseptically in amounts of 10 ml to 200 ml of the melted solid medium, maintained at 48-50ºC. Final medium - The semi-solid part is dispensed first (tubes about 12 x 120 mm) in 2.5 ml amounts and left to harden at room temperature, in vertical position. The solid part is dispensed over the hardened semi-solid one in amounts from 2.0 ml to 2.5 ml and left to harden in slant position, affording a butt of 12 to 15 mm. The tubes of medium should be subjected to a sterility test in the incubator, overnight. Tubes showing spontaneous gas bubbles (air) should then be discarded. The medium should be stored in the incubator (37ºC), for not more than 2 to 4 days. Storage of the tubes in the ice-box produces the absorption of air which is released as bubbles when the tubes are incubated at 37ºC after inoculation. This fact confirmed the observation of ARCHAMBAULT & McCRADY (10) who worked with liquid media and the aplication of their observation was found to be essential to the proper working conditions of this double-layer medium. Inoculation - The inoculation is made by means of a long straight needle, as is usually done on the triple sugar, but the needel should penetrate only to about half of the height of the semi-solid column. Indol detection - After inoculation, a strip of sterelized filter papaer previously moistened with Ehrlich's reagent, is suspended above the surface of the medium, being held between the cotton plug and the tube. Indications given - In addition to providing a mass of organisms on the slant for serological invetigations, the medium gives the following indications: 1. Acid from lactose and/or sucrose (red, of yellowsh with strains which reduce the indicators). 2. Gas from lactose and/or sucrose (bubbles). 3. H[2]S production, observed on the solid part (black). 4. Motility observed on the semi-solid part (tubidity). 5. Urease production, observed on solid and semi-solid parts (blue). 6. Indol production, observed on the strip of filter paper (red or purplish). Indol production is not observed with indol positive strains which rapidly acidify the surface o the slant, and the use of oxalic acid has proved to give less sensitive reaction (11). Reading of results - In most cases overnight incubation is enough; sometimes the reactions appear within only a few hours of incubation, affording a definitive orientation of the diagnosis. With some cultures it is necessary to observe the medium during 48 hours of incubation. A description showing typical differential reaction follows: Salmonella: Color of the medium unchanged, with blackening of the solid part when H[2]S is positive. The slant tends to alkalinity (greenish of bluish). Gas always absent. Indol negative. Motility positive or negative. Shigella: Color of the medium unchanged at the beginning of incubation period, but acquiring a red color when the strain is late lactose/sucrose positive. Slant tending to alkalinity (greenish or purplish). Indol positive or negative. Motility, gas and H[2]S always negative. Proteus: Color of the medium generally changes entirely to blue or sometimes to green (urease positive delayed), with blackening of solid part when H[2]S is positive. Motility positive of negative. Indol positive. Gas positive or negative. The strains which attack rapidly sucrose may give a yellow-greenish color to the medium. Sometimes the intense blue color of the medium renders difficult the reading of the H[2]S production. Escherichiae and Klebsiellae: Color of the medium red or yellow (acid) with great and rapid production of gas. Motility positive or negative. Indol generally impossible to observe. Paracoli: Those lactose of sucrose positive give the same reaction as Esherichia. Those lactose or sucrose negatives give the same reactions as Salmonellae. Sometimes indol positive and H[2]S negative. Pseudomonas: Color of the medium unchanged. The slant tends to alkalinity. It is impossible to observe motility because there is no growth in the bottom. Alkaligenes: Color of the medium unchanged. The slant tends to alkalinity. The medium does not alter the antigenic properties of the strains and with the mass of organisms on the slant we can make the serologic diagnosis. It is admitted that this medium is somewhat more laborious to prepare than others used for similar purposes. Nevertheless it can give informations generally obtained by two or three other media. Its use represents much saving in time, labor and material, and we suggest it for routine laboratory work in which a quick presumptive preliminary grouping of enteric organisms is needed.
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Given a model that can be simulated, conditional moments at a trial parameter value can be calculated with high accuracy by applying kernel smoothing methods to a long simulation. With such conditional moments in hand, standard method of moments techniques can be used to estimate the parameter. Since conditional moments are calculated using kernel smoothing rather than simple averaging, it is not necessary that the model be simulable subject to the conditioning information that is used to define the moment conditions. For this reason, the proposed estimator is applicable to general dynamic latent variable models. Monte Carlo results show that the estimator performs well in comparison to other estimators that have been proposed for estimation of general DLV models.
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Culex siphanulatus, sp. n. is described from specimens collected in bromeliads of the coast of Rio de Janeiro State, Brazil. The description includes illustrations of female, male genitalia and chaetotaxy of pupa and larva. This species is easily distinguished from the others of subgenus Microculex and does not belong to any of the four series proposed for the grouping of its species.