975 resultados para Sib-pair
Resumo:
Women have lower iron stores than men because of iron loss during their reproductive years. However, variation between women could result from differences in iron loss, aspects of iron homeostasis common to men and women, or a combination of both. We compared the effects of age, menopause, menstrual blood loss and the number of pregnancies (sex-specific factors), and the effects of genetic variation, on markers of iron stores. We assessed how much the same genes or other familial factors influence iron status in both men and women. Data from 2039 female twins who participated in studies of reproductive health and iron status were used to estimate the proportions of variation that could be ascribed to genes, environment and measured factors. Significant effects of age, menopausal status and magnitude of menstrual blood loss were demonstrated, accounting for up to 18% of variance in serum ferritin in this sample, but number of children had no significant effect. Genetic effects were more than twice as great as sex-specific effects. The within-pair similarity of ferritin values in dizygotic female twin pairs was greater than for dizygotic opposite-sex pairs, but this difference was not quite significant, consistent with a minor role for sex-specific factors; and the opposite-sex within-pair differences did not diminish significantly with age. We conclude that the contribution of genetic differences between women to variation in iron stores outweighs the comparatively small effects of interindividual variation in iron loss through variation in menstruation and number of pregnancies.
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In the previous two papers in this three-part series, we have examined visual pigments, ocular media transmission, and colors of the coral reef fish of Hawaii. This paper first details aspects of the light field and background colors at the microhabitat level on Hawaiian reefs and does so from the perspective and scale of fish living on the reef. Second, information from all three papers is combined in an attempt to examine trends in the visual ecology of reef inhabitants. Our goal is to begin to see fish the way they appear to other fish. Observations resulting from the combination of results in all three papers include the following. Yellow and blue colors on their own are strikingly well matched to backgrounds on the reef such as coral and bodies of horizontally viewed water. These colors, therefore, depending on context, may be important in camouflage as well as conspicuousness. The spectral characteristics of fish colors are correlated to the known spectral sensitivities in reef fish single cones and are tuned for maximum signal reliability when viewed against known backgrounds. The optimal positions of spectral sensitivity in a modeled dichromatic visual system are generally close to the sensitivities known for reef fish. Models also predict that both UV-sensitive and red-sensitive cone types are advantageous for a variety of tasks. UV-sensitive cones are known in some reef fish, red-sensitive cones have yet to be found. Labroid colors, which appear green or blue to us, may he matched to the far-red component of chlorophyll reflectance for camouflage. Red cave/hole dwelling reef fish are relatively poorly matched to the background they are often viewed against but this may be visually irrelevant. The model predicts that the task of distinguishing green algae from coral is optimized with a relatively long wavelength visual pigment pair. Herbivorous grazers whose visual pigments are known possess the longest sensitivities so far found. Labroid complex colors are highly contrasting complementary colors close up but combine, because of the spatial addition, which results from low visual resolution, at distance, to match background water colors remarkably well. Therefore, they are effective for simultaneous communication and camouflage.
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Chlorophyll fluorescence measurements have a wide range of applications from basic understanding of photosynthesis functioning to plant environmental stress responses and direct assessments of plant health. The measured signal is the fluorescence intensity (expressed in relative units) and the most meaningful data are derived from the time dependent increase in fluorescence intensity achieved upon application of continuous bright light to a previously dark adapted sample. The fluorescence response changes over time and is termed the Kautsky curve or chlorophyll fluorescence transient. Recently, Strasser and Strasser (1995) formulated a group of fluorescence parameters, called the JIP-test, that quantify the stepwise flow of energy through Photosystem II, using input data from the fluorescence transient. The purpose of this study was to establish relationships between the biochemical reactions occurring in PS II and specific JIP-test parameters. This was approached using isolated systems that facilitated the addition of modifying agents, a PS II electron transport inhibitor, an electron acceptor and an uncoupler, whose effects on PS II activity are well documented in the literature. The alteration to PS II activity caused by each of these compounds could then be monitored through the JIP-test parameters and compared and contrasted with the literature. The known alteration in PS II activity of Chenopodium album atrazine resistant and sensitive biotypes was also used to gauge the effectiveness and sensitivity of the JIP-test. The information gained from the in vitro study was successfully applied to an in situ study. This is the first in a series of four papers. It shows that the trapping parameters of the JIP-test were most affected by illumination and that the reduction in trapping had a run-on effect to inhibit electron transport. When irradiance exposure proceeded to photoinhibition, the electron transport probability parameter was greatly reduced and dissipation significantly increased. These results illustrate the advantage of monitoring a number of fluorescence parameters over the use of just one, which is often the case when the F-V/F-M ratio is used.
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The entire internal transcribed spacer ( ITS) region, including the 5.8S subunit of the nuclear ribosomal DNA ( rDNA), was sequenced by direct double-stranded sequencing of polymerase chain reaction (PCR) amplified fragments. The study included 40 Sporobolus ( Family Poaceae, subfamily Chloridoideae) seed collections from 14 putative species ( all 11 species from the S. indicus complex and three Australian native species). These sequences, along with those from two out-group species [ Pennisetum alopecuroides ( L.) Spreng. and Heteropogon contortus ( L.) P. Beauv. ex Roemer & Schultes, Poaceae, subfamily Panicoideae], were analysed by the parsimony method (PAUP; version 4.0b4a) to infer phylogenetic relationships among these species. The length of the ITS1, 5.8S subunit and ITS2 region were 222, 164 and 218 base pairs ( bp), respectively, in all species of the S. indicus complex, except for the ITS2 region of S. diandrus P. Beauv. individuals, which was 217 bp long. Of the 624 characters included in the analysis, 245 ( 39.3%) of the 330 variable sites contained potential phylogenetic information. Differences in sequences among the members of the S. pyramidalis P. Beauv., S. natalensis (Steud.) Dur & Schinz and S. jacquemontii Kunth. collections were 0%, while differences ranged from 0 to 2% between these and other species of the complex. Similarly, differences in sequences among collections of S. laxus B. K. Simon, S. sessilis B. K. Simon, S. elongatus R. Br. and S. creber De Nardi were 0%, compared with differences of 1-2% between these four species and the rest of the complex. When comparing S. fertilis ( Steud.) Clayton and S. africanus (Poir.) Robyns & Tourney, differences between collections ranged from 0 to 1%. Parsimony analysis grouped all 11 species of the S. indicus complex together, indicating a monophyletic origin. For the entire data set, pair-wise distances among members of the S. indicus complex varied from 0.00 to 1.58%, compared with a range of 20.08-21.44% among species in the complex and the Australian native species studied. A strict consensus phylogenetic tree separated 11 species of the S. indicus complex into five major clades. The phylogeny, based on ITS sequences, was found to be congruent with an earlier study on the taxonomic relationship of the weedy Sporobolus grasses revealed from random amplified polymorphic DNA ( RAPD). However, this cladistic analysis of the complex was not in agreement with that created on past morphological analyses and therefore gives a new insight into the phylogeny of the S. indicus complex.
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The mite family Stigmaeidae (Acari:Prostigmata) is of considerable importance in biological control, but its genera are often poorly defined and have never been subjected to cladistic analysis. Herein, we report the stigmaeid genus Ledermuelleriopsis Willmann from Australia for the first time, present a preliminary phylogenetic analysis that demonstrates that Eustigmaeus Berlese and Ledermuelleriopsis Willman are distinct, review the genus at the world level, and provide diagnostic characters of the adult females for each of the 21 known species. We also catalogue habitats, distributions and localities of holotypes. Four new species from Australia are described and illustrated: L. parvilla, sp. nov. from old dune sand, L. barbellata, sp. nov. from wet-sandy heath litter, and L. pustulosa, sp. nov. and L. claviseta, sp. nov. from dry eucalypt forest litter. A key to adult females of all known Ledermuelleriopsis species is provided. The Australian species and L. incisa Wood from New Zealand can be separated from all other members of the genus by a synapomorphy: the reduction of the number of setae on the aggenital shield to one pair. Results of a preliminary morphological cladistic analysis for those stigmaeid genera in which the larvae and adults of both sexes are known, indicate that Ledermuelleriopsis is basal to a clade containing Cheylostigmaeus Willman and Eustigmaeus.
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The crystal structures of a pair of cis and trans isomers of the macrocyclic chloropentaamine title complex, as their tetrachlorozincate(II) salts, [CoCl(C11H27N5)][ZnCl4], are reported. The two distinct isomeric forms lead to significant variations in the Co-N bond lengths and, furthermore, hydrogen bonding between the complex ions is influenced by the folded (cis) or planar (trans) conformations of the coordinated ligand.
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We generate a pair of entangled beams from the interference of two amplitude squeezed beams. The entanglement is quantified in terms of EPR paradox and inseparability criteria, with both results clearly beating the standard quantum limit. We experimentally analyze the effect of decoherence on each criterion and demonstrate qualitative differences. We also characterize the number of required and excess photons present in the entangled beams and provide contour plots of the efficacy of quantum information protocols in terms of these variables.
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Results of experiments recently performed are reported, in which two optical parametric amplifiers were set up to generate two independently quadrature squeezed continuous wave laser beams. The transformation of quadrature squeezed states into polarization squeezed states and into states with spatial quantum correlations is demonstrated. By utilizing two squeezed laser beams, a polarization squeezed state exhibiting three simultaneously squeezed Stokes operator variances was generated. Continuous variable polarization entanglement was generated and the Einstein-Podolsky-Rosen paradox was observed. A pair of Stokes operators satisfied both the inseparability criterion and the conditional variance criterion. Values of 0.49 and 0.77, respectively, were observed, with entanglement requiring values below unity. The inseparability measure of the observed quadrature entanglement was 0.44. This value is sufficient for a demonstration of quantum teleportation, which is the next experimental goal of the authors.
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We generate and characterize continuous variable polarization entanglement between two optical beams. We first produce quadrature entanglement, and by performing local operations we transform it into a polarization basis. We extend two entanglement criteria, the inseparability criteria proposed by Duan et al (2000 Phys. Rev. Lett. 84 2722) and the Einstein–Podolsky–Rosen (EPR) paradox criteria proposed by Reid and Drummond (1988 Phys. Rev. Lett. 60 2731), to Stokes operators; and use them to characterize the entanglement. Our results for the EPR paradox criteria are visualized in terms of uncertainty balls on the Poincaré sphere. We demonstrate theoretically that using two quadrature entangled pairs it is possible to entangle three orthogonal Stokes operators between a pair of beams, although with a bound √3 times more stringent than for the quadrature entanglement.
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Este trabalho objetivou testar a resistência natural da madeira de Eucalyptus grandis de quatro diferentes idades (10, 14, 20 e 25 anos) ao ataque de cupins de madeira seca. As amostras foram retiradas da prancha diametral, na região próxima ao cerne mais externo, em número de seis unidades por tora, de cada uma das 16 árvores (quatro de cada idade). Cada par de amostras foi colocado em contato com 40 indivíduos, da espécie Cryptotermes brevis (cupim de madeira seca), avaliando-se cada par comparativamente com corpos-de-prova de madeira altamente suscetível ao ataque de cupins, no caso a madeira de Pinus elliottii, sob idênticas condições laboratoriais, mediante observações em intervalos periódicos. Ao término do ensaio foram registrados a porcentagem de cupins mortos e o número de furos, além do desgaste produzido por esses insetos. Verificou-se que a madeira de 10 anos foi a mais severamente atacada, com desgaste semelhante ao da testemunha. As madeiras de 14, 20 e 25 anos não diferiram estatisticamente entre si, quanto à resistência natural ao ataque de cupim de madeira seca, todas classificadas como de desgaste acentuado. A madeira de todas as idades mostrou-se altamente suscetível ao ataque de cupins, revelando a baixa resistência natural da espécie.
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O interesse pelo relacionamento entre humanos e cães tem sido crescentemente refletido em produções científicas, apesar destas ainda se mostrarem incipientes no contexto latino-americano, e, por conseguinte, no brasileiro. Nestes termos, quando se toma como foco o relacionamento específico entre cães e pessoas em situação de rua, a incipiência se mostra ainda mais notória, apesar de se tratar de fenômeno que abarca questões interessantes, tanto de cunho individual quanto social e de políticas públicas. Diante disto, a realização do presente estudo se justificou por contribuir com a elucidação da temática, haja vista que teve por objetivo geral: investigar, apontar e compreender relacionamentos estabelecidos por pares que se caracterizem por pertencerem às espécies em questão e por fazerem das ruas espaços para estabelecimento de suas rotinas. Sendo estes critérios de seleção de participantes somados a idade mínima de 18 anos, foram entrevistadas 12 pessoas que nas ocasiões se encontravam em logradouros públicos dos municípios de Vitória, Serra e Vila Velha. Para guiar as entrevistas, foi utilizado roteiro semiestruturado com o intuito de coletar: dados sociais e econômicos dos participantes; conhecer aspectos dos relacionamentos interpessoais dos participantes; acessar relatos que dissessem respeito a partes das histórias de vida de moradores de rua que envolvessem relacionamento com cães; e por fim, recolher informações acerca do uso de serviços de assistência à população de rua, seja na presença ou na ausência do(s) cão(es). Em adição, foram utilizados dados provenientes de conversa informal e voluntária entre a pesquisadora e três funcionárias do Serviço Especializado em Abordagem Social do município de Vitória. A partir daí, os dados coletados foram organizados em cinco grandes itens, nos quais foram detalhadamente analisados e discutidos. Estes itens são: Caracterização sociodemográfica e econômica dos participantes; Caracterização geral dos relacionamentos; Concepções dos participantes acerca dos cães em suas vidas; Repercussões individuais e sociais do relacionamento; e “Sobre pessoas em situação de rua e cães: o "último vínculo"?”. Diante da análise destes, então, tornou-se possível inferir que o relacionamento entre humanos e cães, apesar de manter semelhanças que, por vezes, fazem com que sejam comparados ou equiparados a amizades ou a relacionamentos familiares, se trata de um tipo a parte. Além disto, quando o humano do par homem-cão se encontra em situação de rua, algumas peculiaridades se fazem bastante evidentes, dentre as quais a dificuldade de afastamento do animal, quando em situações momentâneas (por exemplo, em ocasiões de deslocamentos pelas cidades) ou duradouras (como quando por motivos de idas a instituições de abrigamento), em que não é possível tê-lo junto. Por fim, aponta-se como ponderável a recorrente colocação de que o cão seria o único e/ou último vínculo da pessoa em situação de rua com que convive, já que não raramente os participantes mencionaram rearranjos relacionais com humanos posteriores ao início da situação em questão.
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OBJETIVO: O presente trabalho teve como objetivo examinar se medidas práticas de prevenção de perdas auditivas, adotadas por indústrias de Curitiba e região metropolitana, atendem às exigências da legislação trabalhista vigente e recomendações científicas que abordam este tema. FORMA DE ESTUDO: Coorte transversal. MATERIAL E MÉTODO: Um questionário elaborado pelo instituto americano National Institute for Occupational Safety and Health (NIOSH) em 1996, para auditoria de programas de prevenção de perdas auditivas (PPPA), nos serviu de instrumento para a coleta de dados. O instrumento original possui 89 questões divididas em oito temas relacionados à prática dos programas: treinamento e educação, envolvimento do supervisor, medição do ruído, controle de Engenharia e Administrativo, monitoração audiométrica e manutenção dos registros, encaminhamentos, equipamento de proteção individual e questões administrativas. A coleta de dados foi realizada com Médicos do Trabalho, Engenheiros e/ou Técnicos de Segurança das indústrias. As empresas foram divididas em dois grupos: o das empresas que possuem um PPPA e o das que não possuem. CONCLUSÃO: Com base nos dados obtidos concluímos que não houve diferença significativa de conduta entre os grupos e que ambos cumprem parcialmente a legislação trabalhista relacionada à prevenção dos efeitos do ruído. Quanto às questões que abordam aspectos que se excedem às exigências legais, concluímos que as empresas que possuem PPPA dedicam maiores esforços à prevenção de perdas auditivas. Com estes dados identificamos pontos fortes e fracos das medidas que vêm sendo adotadas pelas indústrias da região, os quais poderão nos direcionar à elaboração de medidas preventivas mais efetivas e de propostas para revisão da legislação vigente.
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This study aimed to evaluate the efficiency of simultaneous selection (selection indices) using estimated genetic gains in yellow passion fruit and to make a comparison between the methodologies of Mulamba & Mock and Elston. The study was conducted with 26 sib progenies of yellow passion fruit for intrinsic production characteristics including fruit number, fruit mass, fruit length and diameter, and for the fruit characteristics skin thickness, soluble solids and acidity. Two methodologies were applied: first, in the joint analysis of fruit characteristics and of intrinsic production characteristics in a single phase of selection; and second, in the analysis in two phases, in which priority was given to the intrinsic production characteristics in the first phase, and later, in the second phase, the best fruit characteristics were chosen among the progenies of the first phase. The analysis of variance was applied to the data to detect genetic variability among progenies. The Elston's selection indice was unable to provide distribution of genetic gains consistent with the purposes of the study, as it selected a single progeny of passion fruit. However, the index based on the sum of ranks of Mulamba & Mock was more suitable, as it provided a balanced distribution of gains, selecting a larger number of progenies. The methodology of selection using indices is advantageous in passion fruit, since it contributes to higher genetic gains for all the traits evaluated, and the selection in a single phase was proved efficient for progeny selection.
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This paper presents Palco, a prototype system specifically designed for the production of 3D cartoon animations. The system addresses the specific problems of producing cartoon animations, where the main obj ective is not to reproduce realistic movements, but rather animate cartoon characters with predefined and characteristic body movements and facial expressions. The techniques employed in Palco are simple and easy to use, not requiring any invasive or complicated motion capture system, as both body motion and facial expression of actors are captured simultaneously, using an infrared motion detection sensor, a regular camera and a pair of electronically instrumented gloves. The animation process is completely actor-driven, with the actor controlling the character movements, gestures, facial expression and voice, all in realtime. The actor controlled cartoonification of the captured facial and body motion is a key functionality of Palco, and one that makes it specifically suited for the production of cartoon animations.
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Mestrado em Radiações Aplicadas às Tecnologias da Saúde. Área de especialização: Ressonância Magnética