14 resultados para Roberts, Callum
em Scielo Saúde Pública - SP
Resumo:
Bicotylophora trachinoti (Mac Callum, 1921) from Trachinotus carolinus L.; Pseudanthocotyloides heterocotyle (Van Beneden, 1871) from Cetengraulis edentulus (Cuvier), and Decapterus punctatus (Cuvier), new host records; Pseudomazocraes selene Hargis, 1957 from Selene vomer (L.) and Caranx latus Agassiz, new host record, are reported for the first time in Brazil from the coast of Rio de Janeiro State. The marine fishes Diplectrum sp. and Pomatomus saltatrix (L.) are respectively new host records for Pseudotagia cupida (Hargis, 1956) and Macrovalvitrema sinaloense Caballero & Bravo Hollis, 1955. Measurements, original figures and photos in scanning electron microscopy of B. trachinoti are presented. The egg with filaments is reffered for the first time in the genus Pseudanthocotyloides.
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OBJETIVO: A tuberculose é uma das maiores causas de mortalidade no mundo, porém seus efeitos econômicos são pouco conhecidos. O objetivo do estudo foi o de estimar os custos do tratamento e prevenção da tuberculose para o sistema de saúde (público e privado) e para as famílias. MÉTODOS: O estudo foi realizado no município de Salvador, BA, em 1999. Os dados para estimação dos custos para o sistema de saúde foram coletados nas secretarias de saúde, centros de saúde e em uma entidade filantrópica. Os custos públicos e privados foram estimados pela metodologia da contabilidade de custos. Os dados de custos para as famílias foram coletados por meio de questionários e incluem despesas com transporte, alimentação e outros, bem como as perdas de renda associadas à doença. RESULTADOS: O custo médio para tratamento de um caso novo de tuberculose foi de aproximadamente R$186,00 (US$103); para o tratamento de um paciente multiresistente o custo foi 27 vezes mais alto. Os custos para o serviço público corresponderam a 65% em internações, 32% em tratamento e apenas 3% em prevenção. As famílias comprometeram cerca de 33% da sua renda com despesas relacionadas a tuberculose. CONCLUSÕES: Apesar do fato das famílias não terem que pagar por medicamentos e tratamento, dado que este serviço é oferecido pelo Estado, os custos familiares ligados a perda de rendimentos devido a doença foram muito elevados. A proporção utilizada em prevenção pelo serviço público é pequena. Um maior investimento em campanhas de prevenção poderia não somente diminuir o número de casos, mas também, levar a um diagnósticos precoce, diminuindo os custos associados à hospitalização. A falta de um sistema integrado de custos não permite a visualização dos custos nos diversos setores.
Resumo:
OBJECTIVE: To assess factors associated with depression symptoms in high school students. METHODS: A cross-sectional study involving high school students was conducted in the city of São Paulo, Brazil, 2001. A total of 724 students aged 14-18 years answered questionnaires on life and health conditions. Another questionnaire was applied to working (44.8%) and unemployed (22.9%) students to collect information on working conditions. Factors associated to depressive disorders were analyzed using multiple logistic regression controlled for occupational status. RESULTS: Overall prevalence rate of depression was 7.5%. Rates according to gender were 39 (10.3%) in females and 15 (4.3%) in males. The multiple logistic regression analysis showed that factors associated with depressive disorders were: poor self-perception of health (OR=5.78), being female (OR = 2.45), and alcohol consumption (OR=2.35). CONCLUSIONS: The study results showed that sociodemographic, lifestyle and health variables were associated with symptoms of depression in this population. These ndings suggest that it is important to have mental health professionals available in high schools for early detection of mental conditions and student counseling.
Resumo:
Atypical P. vivax cases reported in Manaus municipality led us to detect a genetic isolate of P. vivax. Variable regions of SSUrRNA were examined from the initial time of infection and in the two recrudescences/relapses from a patient exhibiting chloroquine and primaquine resistance. A unique isolate, found at all stages of infection, suggests the presence of a clonal expansion.
Resumo:
Neste trabalho foi realizada a estimativa da condutância superficial para transferência de vapor d'agua, característica de uma floresta primária próxima a Manaus, à partir de dois diferentes métodos baseados em equações de regressão que procuram associar essa condutância a diferentes variáveis físicas. A equação proposta por Allen (1986) foi estabelecida através da correlação com a radiação líquida média diária, enquanto a estimativa proposta por Roberts et al. (1990) procurou correlacionar a condutância estomática com o déficit de umidade específica e a radiação solar, utilizando dados médios horários e, neste caso, estes valores foram reunidos para representar a média diária correspondente. Uma comparação entre os resultados estimados por tais métodos apresentou o primeiro (Allen) com estimativas sempre inferiores ao segundo (Roberts), da ordem de 30%(±8) na média. Os desvios de ambos também foram relativamente diferentes e, embora tivesse apresentado índices mais elevados de condutância, os desvios do método de Roberts foram de magnitude inferior aos do método de Allen c, portanto, seus valores mostraram-se mais estáveis. As diferenças menores foram observadas no período relativo à estação seca, principalmente nos meses de agosto, setembro e outubro, quando estiveram dentro do limite determinado pela soma dos desvios padrões de ambos.
Resumo:
Este artigo se propõe a apresentar exemplos de questões científicas que puderam ser respondidas no contexto do Projeto LBA (Large Sale Biosphere-Atmosphere Experiment in Amazonia) graças à contribuição de informações derivadas de sensoriamento remoto. Os métodos de sensoriamento remoto permitem integrar informações sobre os vários processos físicos e biológicos em diferentes escalas de tempo e espaço. Nesse artigo, são enfatizados aqueles avanços de conhecimento que jamais seriam alcançados sem a concorrência da informação derivada de sensoriamento.
Resumo:
This paper deals with problems on population genetics in Hymenoptera and particularly in social Apidae. 1) The studies on populations of Hymenoptera were made according to the two basic types of reproduction: endogamy and panmixia. The populations of social Apinae have a mixed method of reproduction with higher percentage of panmixia and a lower of endogamy. This is shown by the following a) males can enter any hive in swarming time; b) males of Meliponini are expelled from hives which does not need them, and thus, are forced to look for some other place; c) Meliponini males were seen powdering themselves with pollen, thus becoming more acceptable in any other hive. The panmixia is not complete owing to the fact that the density of the breeding population as very low, even in the more frequent species as low as about 2 females and 160 males per reproductive area. We adopted as selection values (or survival indices) the expressions according to Brieger (1948,1950) which may be summarised as follows; a population: p2AA + ²pq Aa + q2aa became after selection: x p2AA + 2pq Aa + z q²aa. For alge-braics facilities Brieger divided the three selective values by y giving thus: x/y p2 AA + y/y 2 pq Aa + z/y q²aa. He called x/y of RA and z/y of Ra, that are survival or selective index, calculated in relation to the heterozygote. In our case all index were calculated in relation to the heterozygote, including the ones for haploid males; thus we have: RA surveval index of genotype AA Ra surveval index of genotype aa R'A surveval index of genotype A R'a surveval index of genotype a 1 surveval index of genotype Aa The index R'A ande R'a were equalized to RA and Ra, respectively, for facilities in the conclusions. 2) Panmitic populations of Hymenoptera, barring mutations, migrations and selection, should follow the Hardy-Weinberg law, thus all gens will be present in the population in the inicial frequency (see Graphifc 1). 3) Heterotic genes: If mutation for heterotic gene ( 1 > RA > Ra) occurs, an equilibrium will be reached in a population when: P = R A + Ra - 2R²a _____________ (9) 2(R A + Ra - R²A - R²a q = R A + Ra - 2R²A _____________ (10) 2(R A + Ra - R²A - R²a A heterotic gene in an hymenopteran population may be maintained without the aid of new mutation only if the survival index of the most viable mutant (RA) does not exced the limiting value given by the formula: R A = 1 + √1+Ra _________ 4 If RA has a value higher thah the one permitted by the formula, then only the more viable gene will remain present in the population (see Graphic 10). The only direct proof for heterotic genes in Hymenoptera was given by Mackensen and Roberts, who obtained offspring from Apis mellefera L. queens fertilized by their own sons. Such inbreeding resulted in a rapid loss of vigor the colony; inbred lines intercrossed gave a high hybrid vigor. Other fats correlated with the "heterosis" problem are; a) In a colony M. quadrifasciata Lep., which suffered severely from heat, the percentage of deths omong males was greater .than among females; b) Casteel and Phillips had shown that in their samples (Apis melifera L). the males had 7 times more abnormalities tian the workers (see Quadros IV to VIII); c) just after emerging the males have great variation, but the older ones show a variation equal to that of workers; d) The tongue lenght of males of Apis mellifera L., of Bombus rubicundus Smith (Quadro X), of Melipona marginata Lep. (Quadro XI), and of Melipona quadrifasciata Lep. Quadro IX, show greater variationthan that of workers of the respective species. If such variation were only caused by subviables genes a rapid increasse of homozigoty for the most viable alleles should be expected; then, these .wild populations, supposed to be in equilibrium, could .not show such variability among males. Thus we conclude that heterotic genes have a grat importance in these cases. 4) By means of mathematical models, we came to the conclusion tht isolating genes (Ra ^ Ra > 1), even in the case of mutations with more adaptability, have only the opor-tunity of survival when the population number is very low (thus the frequency of the gene in the breeding population will be large just after its appearence). A pair of such alleles can only remain present in a population when in border regions of two races or subspecies. For more details see Graphics 5 to 8. 5) Sex-limited genes affecting only females, are of great importance toHymenoptera, being subject to the same limits and formulas as diploid panmitic populations (see formulas 12 and 13). The following examples of these genes were given: a) caste-determining genes in the genus Melipona; b) genes permiting an easy response of females to differences in feeding in almost all social Hymenoptera; c) two genes, found in wild populations, one in Trigona (Plebéia) mosquito F. SMITH (quadro XII) and other in Melipona marginata marginata LEP. (Quadro XIII, colonies 76 and 56) showing sex-limited effects. Sex-limited genes affecting only males do not contribute to the plasticity or genie reserve in hymenopteran populations (see formula 14). 6) The factor time (life span) in Hymenoptera has a particular importance for heterotic genes. Supposing one year to be the time unit and a pair of heterotic genes with respective survival indice equal to RA = 0, 90 and Ra = 0,70 to be present; then if the life time of a population is either one or two years, only the more viable gene will remain present (see formula 11). If the species has a life time of three years, then both alleles will be maintained. Thus we conclude that in specis with long lif-time, the heterotic genes have more importance, and should be found more easily. 7) The colonies of social Hymenoptera behave as units in competition, thus in the studies of populations one must determine the survival index, of these units which may be subdivided in indice for egg-laying, for adaptive value of the queen, for working capacity of workers, etc. 8) A study of endogamic hymenopteran populations, reproduced by sister x brother mating (fig. 2), lead us to the following conclusions: a) without selection, a population, heterozygous for one pair of alleles, will consist after some generations (theoretically after an infinite number of generation) of females AA fecundated with males A and females aa fecundated with males a (see Quadro I). b) Even in endogamic population there is the theoretical possibility of the presence of heterotic genes, at equilibrium without the aid of new mutations (see Graphics 11 and 12), but the following! conditions must be satisfied: I - surveval index of both homozygotes (RA e Ra) should be below 0,75 (see Graphic 13); II - The most viable allele must riot exced the less viable one by more than is permited by the following formula (Pimentel Gomes 1950) (see Gra-fic 14) : 4 R5A + 8 Ra R4A - 4 Ra R³A (Ra - 1) R²A - - R²a (4 R²a + 4 Ra - 1) R A + 2 R³a < o Considering these two conditions, the existance of heterotic genes in endogamic populations of Hymenoptera \>ecames very improbable though not - impossible. 9) Genie mutation offects more hymenopteran than diploid populations. Thus we have for lethal genes in diploid populations: u = q2, and in Hymenoptera: u = s, being u the mutation ratio and s the frequency of the mutant in the male population. 10) Three factors, important to competition among species of Meliponini were analysed: flying capacity of workers, food gathering capacity of workers, egg-laying of the queen. In this connection we refer to the variability of the tongue lenght observed in colonies from several localites, to the method of transporting the pollen in the stomach, from some pots (Melliponi-ni storage alveolus) to others (e. g. in cases of pillage), and to the observation that the species with the most populous hives are almost always the most frequent ones also. 11) Several defensive ways used for Meliponini to avoid predation are cited, but special references are made upon the camouflage of both hive (fig. 5) and hive entrance (fig. 4) and on the mimetism (see list in page ). Also under the same heading we described the method of Lestrimelitta for pillage. 12) As mechanisms important for promoting genetic plasticity of hymenopteran species we cited: a) cytological variations and b) genie reserve. As to the former, duplications and numerical variations of chromosomes were studied. Diprion simile ATC was cited as example for polyploidy. Apis mellife-ra L. (n = 16) also sugests polyploid origen since: a) The genus Melipona, which belongs to a" related tribe, presents in all species so far studied n = 9 chromosomes and b) there occurs formation of dyads in the firt spermatocyte division. It is su-gested that the origin of the sex-chromosome of Apis mellifera It. may be related to the possible origin of diplo-tetraploidy in this species. With regards to the genie reserve, several possible types of mutants were discussed. They were classified according to their survival indices; the heterotic and neutral mutants must be considered as more important for the genie reserve. 13) The mean radius from a mother to a daghter colony was estimated as 100 meters. Since the Meliponini hives swarm only once a year we may take 100 meters a year as the average dispersion of female Meliponini in ocordance to data obtained from Trigona (tetragonisca) jaty F. SMITH and Melipona marginata LEP., while other species may give different values. For males the flying distance was roughly estimated to be 10 times that for females. A review of the bibliography on Meliponini swarm was made (pg. 43 to 47) and new facts added. The population desity (breeding population) corresponds in may species of Meliponini to one male and one female per 10.000 square meters. Apparently the males are more frequent than the females, because there are sometimes many thousands, of males in a swarm; but for the genie frequency the individuals which have descendants are the ones computed. In the case of Apini and Meliponini, only one queen per hive and the males represented by. the spermatozoos in its spermateca are computed. In Meliponini only one male mate with the queen, while queens of Apis mellijera L. are fecundated by an average of about 1, 5 males. (Roberts, 1944). From the date cited, one clearly sees that, on the whole, populations of wild social bees (Meliponini) are so small that the Sewall Wright effect may become of great importance. In fact applying the Wright's formula: f = ( 1/aN♂ + 1/aN♀) (1 - 1/aN♂ + 1/aN♀) which measures the fixation and loss of genes per generation, we see that the fixation or loss of genes is of about 7% in the more frequent species, and rarer species about 11%. The variation in size, tergite color, background color, etc, of Melipona marginata Lep. is atributed to this genetic drift. A detail, important to the survival of Meliponini species, is the Constance of their breeding population. This Constance is due to the social organization, i. e., to the care given to the reproductive individuals (the queen with its sperm pack), to the way of swarming, to the food storage intended to control variations of feeding supply, etc. 14) Some species of the Meliponini are adapted to various ecological conditions and inhabit large geographical areas (e. g. T. (Tetragonisca jaty F. SMITH), and Trigona (Nanno-trigona testaceicornis LEP.) while others are limited to narrow regions with special ecological conditions (e. g. M. fuscata me-lanoventer SCHWARZ). Other species still, within the same geographical region, profit different ecological conditions, as do M. marginata LEP. and M. quadrifasciata LEP. The geographical distribution of Melipona quadrifasciata LEP. is different according to the subspecies: a) subsp anthidio-des LEP. (represented in Fig. 7 by black squares) inhabits a region fron the North of the S. Paulo State to Northeastern Brazil, ,b) subspecies quadrifasciata LEP., (marked in Fig. 7 with black triangles) accurs from the South of S. Paulo State to the middle of the State of Rio Grande do Sul (South Brazil). In the margined region between these two areas of distribution, hi-brid colonies were found (Fig. 7, white circles); they are shown with more details in fig. 8, while the zone of hybridization is roughly indicated in fig. 9 (gray zone). The subspecies quadrifasciata LEP., has 4 complete yellow bands on the abdominal tergites while anthidioides LEP. has interrupted ones. This character is determined by one or two genes and gives different adaptative properties to the subspecies. Figs. 10 shows certains meteorological isoclines which have aproximately the same configuration as the limits of the hybrid zone, suggesting different climatic adaptabilities for both genotypes. The exis-tance of a border zone between the areas of both subspecies, where were found a high frequency of hybrids, is explained as follows: being each subspecies adapted to a special climatic zone, we may suppose a poor adaptation of either one in the border region, which is also a region of intermediate climatic conditions. Thus, the hybrids, having a combination of the parent qualities, will be best adapted to the transition zone. Thus, the hybrids will become heterotic and an equilibrium will be reached with all genotypes present in the population in the border region.
Resumo:
1) Inicialmente foi dado um breve resumo dos métodos básicos do melhoramento no milho os quais podem ser reunidos em dois grupos principais: o processo do milho híbrido, com as suas variantes, e os processos dos sintéticos. Estes últimos podem ainda ser subdivididos em duas categorias: os sintéticos simples e os sintéticos balançados. Na obtenção dos sintéticos simples toma-se inicialmente em consideração a capacidade combinatória das linhagens a serem misturadas, e se executa em cada geração de sintético uma seleção massal de conservação. Nos balançados devemos acrescentar uma forte seleção, na fase preparatória, contra todos os híbridos que dão segregações mendelianas fortes demais. 2) No curso de um breve resumo histórico ficou evidente que a idéia de se aproveitarem os sintéticos no melhoramento do milho, formulada pela primeira vez por Hayes e Garber (1919) deu resultados práticos apreciáveis. Assim Hayes, Rinke e Tsinang (1944) obtiveram produções de sintéticos que eram equivalentes de um híbrido duplo, Minhybrid 403. Lonnquist (1949) registrou produções de sintéticos idênticos ao híbrido duplo, US 13. Roberts, Wellhausen, Palácios e Guaves (1949) e Wellhausen (1950) relataram resultados bastante satisfatórios, obtidos no México. 3) Ficou demonstrado que as fórmulas de Sewall Wright (1932) e de Mangelsdorf (1939) não podem ser consideradas como explicações gerais do método, pois pela sua derivação pode-se mostrar facilmente que elas exigem certas premissas que nem sempre são justificáveis. 4) Para eliminar confusões na terminologia foi desenvolvido um esquema básico da constituição de sintéticos supondo que se parte de linhagens autofecundadas e que foram plantadas em conjunto para a reprodução de cruzamento livre. A geração que consiste das plantas autofecundadas, plantadas em mistura, é denominada SyO. A geração seguinte, a qual contém uma maior percentagem de híbridos simples e uma menor per-centagem de descendentes de cruzamentos dentro de mesma linhagem (descendentes consanguíneos) representa assim a geração Syl. A geração que segue depois de novo cruzamento livre, Sy2, será então composta de híbridos entre quatro linhagens (híbridos duplos"), entre três linhagens ("three way crosses"), entre duas linhagens ("híbridos simples") e descendentes de combinações consanguíneas, ("inbreds"). Porém se houver uma seleção em Sy1 que elimina todos os descendentes de combinações consanguíneas, sobrevivendo apenas híbridos simples, então a geração Sy2 será composta de híbridos entre plantas que não tem nenhuma das linhagens originais em comum, os que têm uma linhagem em comum e finalmente aqueles que têm duas linhagens em comum. 5) Empregando esta classificação das gerações, podemos verificar que a geração Sy1 de Lonnquist corresponde à geração Sy1 do esquema básico, a geração Sy1 deHayes et al corresponde à geração Sy2 do esquema básico é a geração Sy1 de Wellhausen et al corresponde aproximadamente à geração Sy3 do esquema básico. 6) Uma teoria mais correta dos sintéticos deve-se basear nas regras da genética em populações, as quais foram empregadas por Brieger para justificar o processo dos sintéticos balançados. Uma discussão mais detalhada desta teoria será assim dada numa outra publicação que se ocupara especialmente com ossintéticos balançados.
Resumo:
Neste presente trabalho os autores criam uma nova espécie para o subgênero Plagioporus (Plagioporus) Stafford, 1904, P. (P.) dollfusi sp. n. fica no grupo "b" da distribuição de travassos & cols. (1966), mais se aproximando de P. (P.) multilobatus Travassos & cols. 1966, distinguindo-se principalmente por possuir o limite anterior dos vitelinos na zona acetabular, poro genital bifurcal, bolsa do cirro alcançando a zona acetabular e ovos menores. Apresentam como novas ocorrências Enenterum pimelopteri Nagaty 1942 e Pseudopecoelus priacanthi (Mac Callum, 1921) manter, 1947. Apresentam ainda Garrupa sp. como novo hospedeiro de Pseudopecoelus priacanthi. Referem a presença de Hysterolecitha elongata manter, 1931, Bucephalus varicus manter, 1940, Metadena spectanda travassos, Freitas & Bührnheim, 1967 e uma fêmea jovem de Echinorhynchideae Southwell & Macfie, 1925 (Acanthocephala).
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Development of vaccines against Toxoplasma gondii infection in humans is of high priority, given the high burden of disease in some areas of the world like South America, and the lack of effective drugs with few adverse effects. Rodent models have been used in research on vaccines against T. gondii over the past decades. However, regardless of the vaccine construct, the vaccines have not been able to induce protective immunity when the organism is challenged with T. gondii, either directly or via a vector. Only a few live, attenuated T. gondii strains used for immunization have been able to confer protective immunity, which is measured by a lack of tissue cysts after challenge. Furthermore, challenge with low virulence strains, especially strains with genotype II, will probably be insufficient to provide protection against the more virulent T. gondii strains, such as those with genotypes I or II, or those genotypes from South America not belonging to genotype I, II or III. Future studies should use animal models besides rodents, and challenges should be performed with at least one genotype II T. gondii and one of the more virulent genotypes. Endpoints like maternal-foetal transmission and prevention of eye disease are important in addition to the traditional endpoint of survival or reduction in numbers of brain cysts after challenge.
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A equação de Ellis & Roberts utiliza a temperatura, a umidade e a qualidade inicial da semente para predizer sua longevidade, porém exige experimentos complexos e demorados. O objetivo deste trabalho foi simplificar a equação de viabilidade para predizer a longevidade da semente de milho e soja em condições de armazenamento aberto. A equação simplificada é explicada pelo modelo Vp = Vi - (tgbeta).p, em que Vp é a viabilidade em probit no período p, Vi é a germinação inicial do lote e tgb é a taxa de deterioração da semente para cada espécie. Sementes de milho BRS201 e BRS206 e soja cultivar IAC-8 e MG/BR 46 (Conquista) foram embaladas em sacos de papel e armazenadas por 0, 30, 60, 90, 120, 150, 180, 240, 300 e 360 dias, em galpões abertos, em Sete Lagoas, MG, e Brasília, DF. Os dados foram transformados em 'probit' e a declividade da reta (tgbeta) foi calculada entre 0 e 30 dias. O coeficiente (tgbeta) variou de 1,4767.10-3 a 2,687.10-3 em milho e de 2,868.10-3 a 3,617.10-3 em soja, dependendo das condições climáticas do armazém. A germinação da semente de soja declinou mais rapidamente que a de milho. O modelo prediz com precisão a longevidade das sementes de milho e soja em armazém aberto.
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The objective of this work was to determine the viability equation constants for cottonseed and to detect the occurrence and depletion of hardseededness. Three seedlots of Brazilian cultivars IAC-19 and IAC-20 were tested, using 12 moisture content levels, ranging from 2.2 to 21.7% and three storage temperatures, 40, 50 and 65ºC. Seed moisture content level was reached from the initial value (around 8.8%) either by rehydration, in a closed container, or by drying in desiccators containing silica gel, both at 20ºC. Twelve seed subsamples for each moisture content/temperature treatment were sealed in laminated aluminium-foil packets and stored in incubators at those temperatures, until complete survival curves were obtained. Seed equilibrium relative humidity was recorded. Hardseededness was detected at moisture content levels below 6% and its releasing was achieved either naturally, during storage period, or artificially through seed coat removal. The viability equation quantified the response of seed longevity to storage environment well with K E = 9.240, C W = 5.190, C H = 0.03965 and C Q = 0.000426. The lower limit estimated for application of this equation at 65ºC was 3.6% moisture content.