1,081 research outputs found

    Lasso Estimation of an Interval-Valued Multiple Regression Model

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    A multiple interval-valued linear regression model considering all the cross-relationships between the mids and spreads of the intervals has been introduced recently. A least-squares estimation of the regression parameters has been carried out by transforming a quadratic optimization problem with inequality constraints into a linear complementary problem and using Lemke's algorithm to solve it. Due to the irrelevance of certain cross-relationships, an alternative estimation process, the LASSO (Least Absolut Shrinkage and Selection Operator), is developed. A comparative study showing the differences between the proposed estimators is provided

    Sobrevivência e obtenção de mutantes induzidos por agentes mutagênicos em Metarhizium anisopliae

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    Uma linhagem selvagem do fungo entomopatogênico Metarhizium anisopliae foi submetida à ação de três agentes mutagênicos: radiação gama, luz ultravioleta e ácido nitroso. Curvas de sobrevivência foram obtidas para cada mutagênicos utilizado e mutantes foram selecionados a partir de doses dos mutagênicos que proporcionassem de 1 a 5% de sobrevivência. Mutantes morfológicos para a coloração de conídios e mutantes auxotróficos foram isolados. Mutantes para coloração de conidios foram agrupados em duas classes, uma com conídios amarelos e outra com conídios vinho pálido. Os mutantes auxotróficos obtidos foram deficientes para aminoácidos e vitaminas e mais de 58% deles eram auxotróficos para prolina/argmina. Radiação gama foi o mutagênico mais eficiente com uma porcentagem de obtenção de mulantes auxotróficos de aproximadamente 0,2%, seguido pela luz ultravioleta (0.12%) e pelo ácido nitroso (0.06%).Os mulantes morfológicos e auxotróficos obtidos até o momento em Metarhizium anisopliae foram revistos.A wild strain of Metarhizium anisopliae, an entomopathogenic fungus, was submitted to three mutagenic agents: gamma radiation, ultraviolet light and nitrous acid. Survival curves were obtained and mutants were selected using different mutagenic doses which gave 1 to 5% survival. Morphological and auxotrophic mutants were isolated. Morphological mutants were grouped in a class with yellow conidia and other with pale vinaceous conidia as opposed to the green wild type conidia. Auxotrophic mutants had requirements for vitamin and aminoacid biosynthesis. More than 58% of the total auxotrophk mutants required proline/aipnine. Gamma radiation showed to be the most efficient mutagenic agent giving 0.2% of auxotrophk mutants followed by ultraviolet light (0.12%) and nitrous acid (0.06%).The conidial colour and auxotrophk mutants isolated until now from M. anisopliae were reviewed

    Comunicação Cientifica - Distribuição Geopolítica da Fasciolose Hepática na Ilha de Santiago, Cabo Verde

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    O trabalho foi realizado no intuito de registrar a distribuição geopolítica da Fasciolose Hepática na Ilha de Santiago, Cabo Verde. Durante a avaliação, realizada de maio a junho de 2008, foram registrados tamanho e taxas de infecção do molusco, pH e temperatura da água e taxas de infecção de vertebrados. As amostras de moluscos e de fezes de bovinos foram coletadas, de forma aleatória, em todos os municípios da Ilha de Santiago, com exceção de Tarrafal, e, devidamente embaladas, encaminhadas para o Laboratório do Instituto Nacional de Investigação e Desenvolvimento Agrário (INIDA), onde foram analisadas. As análises demonstraram resultados positivos para a coproscopia de bovinos e a presença do hospedeiro intermediário (Lymnaea natalensis) em todos os municípios visitados. Também ficou demonstrada uma correlação positiva entre a taxa de infecção dos hospedeiros vertebrados e invertebrados, sendo que o maior índice foi registrado no Município de Santa Cruz (72,72%) e o menor no da Praia (16,66%). A taxa de infecção média verificada para os moluscos e os bovinos foi de 51,51% e 37,15%, respectivamente.GEOPOLITIC DISTRIBUITION OF HEPATIC FASCIOLOSIS ON SANTIAGO ISLAND, CAPE VERDE. A survey was carried out in order to study the geopolitical distribution of fascioliasis on Santiago Island, Cape Verde. During the evaluation, conducted from May to June 2008, measurements were made and recorded regarding the size and infection rates of the snail, pH and water temperature and vertebrate infection rates. Snails and bovine feces samples were collected at random in all municipalities of Santiago Island, except Tarrafal, properly packed, and sent to the Laboratory of National Institute of Agricultural Research and Development (INIDA) where they were analyzed. The results showed positive results for stool examinations of cattle and the presence of an intermediate host (Lymnaea natalensis) in all localities visited. A positive correlation was also found between the vertebrate and invertebrate infection rate, with the highest rate recorded in Santa Cruz (72.72%) and the lowest in Praia (16.66%). The average infection rate observed for the snails and cattle was 51.51% and 37.15%, respectively

    Selection of resistant upland cotton genotypes challenged with aggressive isolates of Meloidogyne incognita race 3

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    Received: July 11th, 2022 ; Accepted: August 19th, 2022 ; Published: August 25th, 2022 ; Correspondence: [email protected] study aimed to select populations of M. incognita race 3 for screening cotton genotypes as part of a breeding program for the development of resistant cotton cultivars. Five isolates of M. incognita race 3, collected in Western Paraná, Brazil, were tested for virulence and aggressiveness against the cotton cultivars FM966 (susceptible), IAC 24 (resistant), CD 409, and FMT 701 (moderately resistants) under greenhouse conditions, and following a factorial design with five replicates. Thirty-one cotton genotypes were screened against the three most aggressive isolates of M. incognita race 3 tested before and kept under greenhouse conditions following a factorial design with five replicates. Experiments run under greenhouse conditions had single cotton plants inoculated with 5,000 eggs/J2 of M. incognita and were assessed at 120 days after inoculation considering the variables gall index, egg mass index, total eggs, and reproduction factor. The same genotypes tested under greenhouse conditions were also grown in a field infested with M. incognita race 3 in a randomized block design with 10 replicates. In the field, the M. incognita population was monitored by the quantification of J2 forms in soil samples collected before sowing, 60 days after sowing (DAS), and 120 DAS. A gall index score was used to evaluate the roots of cotton genotypes at 120 DAS. The isolate from Umuarama was the most aggressive, followed by Moreira Sales and Iporã. The genotypes CD 05-419, CD 05-945, CD 05-1087, and CD 05-1170 showed resistance against M. incognita race 3 under greenhouse and field conditions

    Raman Spectroscopy of Amino Acid Crystals

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    In this chapter, we investigate the Raman spectra of proteinogenic amino acid crystals. Amino acids are fundamental organic molecules that compose polypeptides (a linear chain of amino acids) and proteins (folded polypeptides with specific functions) found in all living beings. Surprisingly, the number of these basic molecules is not more than 22 (20 of them commonly known as the standard amino acids, plus pyrrolysine and selenocysteine). They are defined as a molecule formed by an NH2 group, a COOH group, a lateral chain (the R group), and a hydrogen atom, all of them connected to a single carbon, the α-carbon. Interestingly, α-amino acids show chirality, i.e., they present different distributions of group of atoms around the α-carbon, being defined as l- and d-form. For amino acids and proteins found in the living beings, the l-form is the dominant form, although some exceptions have been discovered in the last decades. In this chapter, we present the Raman spectra of all standard amino acids and discuss the different kinds of vibrations found, comparing them. As complementary part of the work, we present results on vibrational properties of some amino acids using Raman spectroscopy when subjected to specific conditions, with variation in temperature or pressure. Finally, we present some perspectives as the investigation of purines, a group of molecules associated with the DNA molecule

    Analysis of access to hypertensive and diabetic drugs in the Family Health Strategy, State of Pernambuco, Brazil

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    OBJECTIVE: To evaluate the access to drugs for hypertension and diabetes and the direct cost of buying them among users of the Family Health Strategy (FHS) in the state of Pernambuco, Brazil. METHODS: Population-based, cross-sectional study of a systematic random sample of 785 patients with hypertension and 823 patients with diabetes mellitus who were registered in 208 randomly selected FHS teams in 35 municipalities of the state of Pernambuco. The selected municipalities were classified into three levels with probability proportional to municipality size (LS, large-sized; MS, medium-sized; SS, small-sized). To verify differences between the cities, we used the χ2 test. RESULTS: Pharmacological treatment was used by 91.2% patients with hypertension whereas 85.6% patients with diabetes mellitus used oral antidiabetic drugs (OADs), and 15.4% used insulin. The FHS team itself provided antihypertensive medications to 69.0% patients with hypertension, OADs to 75.0% patients with diabetes mellitus, and insulin treatment to 65.4%. The 36.9% patients with hypertension and 29.8% with diabetes mellitus that had to buy all or part of their medications reported median monthly cost of R18.30,R 18.30, R 14.00, and R$ 27.61 for antihypertensive drugs, OADs, and insulin, respectively

    Sistema tradicional de manejo de caprinos: I. Desempenho de crescimento de caprinos SRD na fase de aleitamento

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    The effects of season, sex and type of birth as well as all possible interactions were studied for birth weight (BW), weights at 41 (W1), 69 (W2), 97 (W3), and 125 (W4) days after birth and weight gains at intervals between the time of birth and 41 days of age (G1), 41 and 69 days (G2), 69 and 97 days (G3), 97 and 125 days (G4) of age after birth. Data were initialy recorded on 120 kids born in the years 1979 and 1980 and raised at the Centro Nacional de Pesquisa de Caprinos research farm, Sobral, State of Ceará, Brazil. The analysis of variance showed that season of birth had a highly significant (P<0.005) effect on alt weights analysed and on G1 and G4. The significant level was smaller (P<0.025) for G2 and G3 . Kids born in the rainy season were heavier and had higher weight gains than kids born in the dry season. Sex had a significant influence on BW, W2, W4 (P<0.05), W3 (P<0.025), W1 and G1 (P<0.005). Males were superior to females, except in G4 where an inverse trend was observed. Type of birth was significant (P<0.005) for all the weight variables studied, including G1. Single born kids showed higher weight gains than did multiple born kids. With the exception of the season X type of birth interaction which was significant (P <0.025) for BW, all other interactions analized were none significant for the variables studied.Foram estudados os efeitos da estação, sexo e tipo de nascimento, bem como os das interações possíveis, sobre os pesos ao nascimento (PN); aos 41 (P1); aos 69 (P2); aos 97 (P3) e aos 125 (P4) dias de idade e sobre os ganhos de peso do nascimento aos 41 (G1); dos 41 aos 69 (G2); dos 69 aos 97 (G3) e dos 97 aos 125 (G4) dias de idade. Foram utilizados 120 cabritos, criados na área experimental do Centro Nacional de Pesquisa de Caprinos, em Sobral, CE, nascidos entre os anos de 1979 e 1980. As análises de variância indicaram que a estação de nascimento influenciou de maneira significativa (P<0,005) todos os pesos estudados, além das variáveis G1 e G4, e ao nível de P<0,025, as variáveis G2 e G3. Os animais nascidos na estação chuvosa foram mais pesados e apresentaram maior ganho de peso, em relação aos nascidos na estação seca. O sexo influenciou o P1 e G1 (P<0,005) e o PN, P2 e P4 (P<0,05) e P3 (P<0,025), sendo que, nessas variáveis, os machos foram superiores às fêmeas, exceto em G4, nas quais se observou tendência inversa. Houve influência do tipo de nascimento sobre todos os pesos estudados, inclusive sobre o G1, (P<0,005); os animais nascidos de partos simples mostraram maior ganho de peso que os nascidos de partos múltiplos. Com exceção da interação estação X tipo de nascimento, que influenciou de maneira significativa (P<0,025) o PN, as demais interações não apresentaram efeito significativo sobre as variáveis estudadas

    Einstein energy associated with the Friedmann -Robertson -Walker metric

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    Following Einstein's definition of Lagrangian density and gravitational field energy density (Einstein, A., Ann. Phys. Lpz., 49, 806 (1916); Einstein, A., Phys. Z., 19, 115 (1918); Pauli, W., {\it Theory of Relativity}, B.I. Publications, Mumbai, 1963, Trans. by G. Field), Tolman derived a general formula for the total matter plus gravitational field energy (P0P_0) of an arbitrary system (Tolman, R.C., Phys. Rev., 35(8), 875 (1930); Tolman, R.C., {\it Relativity, Thermodynamics & Cosmology}, Clarendon Press, Oxford, 1962)); Xulu, S.S., arXiv:hep-th/0308070 (2003)). For a static isolated system, in quasi-Cartesian coordinates, this formula leads to the well known result P0=g(T00T11T22T33) d3xP_0 = \int \sqrt{-g} (T_0^0 - T_1^1 -T_2^2 -T_3^3) ~d^3 x, where gg is the determinant of the metric tensor and TbaT^a_b is the energy momentum tensor of the {\em matter}. Though in the literature, this is known as "Tolman Mass", it must be realized that this is essentially "Einstein Mass" because the underlying pseudo-tensor here is due to Einstein. In fact, Landau -Lifshitz obtained the same expression for the "inertial mass" of a static isolated system without using any pseudo-tensor at all and which points to physical significance and correctness of Einstein Mass (Landau, L.D., and Lifshitz, E.M., {\it The Classical Theory of Fields}, Pergamon Press, Oxford, 2th ed., 1962)! For the first time we apply this general formula to find an expression for P0P_0 for the Friedmann- Robertson -Walker (FRW) metric by using the same quasi-Cartesian basis. As we analyze this new result, physically, a spatially flat model having no cosmological constant is suggested. Eventually, it is seen that conservation of P0P_0 is honoured only in the a static limit.Comment: By mistake a marginally different earlier version was loaded, now the journal version is uploade

    Green manure in coffee systems in the region of Zona da Mata, Minas Gerais: characteristics and kinetics of carbon and nitrogen mineralization.

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    The use of green manure may contribute to reduce soil erosion and increase the soil organic matter content and N availability in coffee plantations in the Zona da Mata, State of Minas Gerais, in Southeastern Brazil. The potential of four legumes (A. pintoi, C. mucunoides, S. aterrimum and S. guianensis)to produce above-ground biomass, accumulate nutrients and mineralize N was studied in two coffee plantations of subsistence farmers under different climate conditions. The biomass production of C. mucunoides was influenced by the shade of the coffee plantation.C. mucunoides tended to mineralize more N than the other legumes due to the low polyphenol content and polyphenol/N ratio. In the first year, the crop establishment of A. pintoi in the area took longer than of the other legumes, resulting in lower biomass production and N2 fixation. In the long term, cellulose was the main factor controlling N mineralization. The biochemical characteristics, nutrient accumulation and biomass production of the legumes were greatly influenced by the altitude and position of the area relative to the sun
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