Singh Method Research Articles

Morphological characterization and analysis of genetic variability among pepper accessions

ABSTRACT: The peppers of the genus Capsicumhave economic potential and elevated genetic variability. The objective of the study was to characterize morpho-agronomically and estimate the genetic divergence among pepper accessions of the active germplasm bank of Capsicumof the Instituto Federal do Espírito Santo, Campus Alegre. Thirty accessions were characterized based on ten morphological descriptors being the experimental design completely randomized, with six repetitions. Genetic diversity among the accessions was estimated by the Tocher grouping method as a measurement of dissimilarity and formed eight groups. The Singh method, used to estimate the relative contribution of each character in the expression of genetic divergence, indicated that the diameter of the produce (20.19%) and the height of the plant (19.46%) were the ones to contribute most to the total divergence (39.65%) among the accessions of pepper being studied. The study evidenced the existence of high genetic variability among the accessions of C. annuumcollected in the south region of the state of Espírito Santo. No correlation was detected between the genetic distance and location of collections.

In vitro enhancement of psoralen as an important anticancer compound in Psoralea corylifolia through precursor feeding

Context: Psoralea corylifolia L. (Fabacese) is rich source of bioactive compounds, which endows the plant with immense value for its use in pharmaceuticals, health, and body-care products.Objective: The current study was designed (i) for the determination of psoralen from callus derived from different plant parts, and (ii) for the enhancement of psoralen in in vitro condition with the treatment of various psoralen pathway precursors.Materials and methods: B5 media were employed for raising the cultures from different plant parts such as leaf, node, root, and green seeds. Cotyledons’ calluses were derived from cotyledon of green seeds that were elicited on MS + 10 µM BA + 5 µM IBA medium supplemented at 0.1, 1, 2.5, 5, 25, and 50 mg/L of various psoralen pathway precursors such as umbelliferone, cinnamic acid, and NADPH. The method for extraction of psoralen was modified from the Singh method and the content of psoralen was measured using HPLC.Results: HPLC analysis of callus derived from different parts of P. corylifolia revealed that a maximum of psoralen (2601.8 µg/g fresh wt.) was recorded in cotyledons’ callus. Cotyledonary callus was chosen for the enhancement of psoralens because of higher amount of psoralen in it. In vitro evaluation showed that all the precursors enhanced the psoralen amount dramatically so that the optimum amount of psoralen (2518.8 µg/g fresh wt.) was obtained at 2.5 mg/L cinnamic acid.Discussion and conclusion: The results obtained indicate that cinnamic acid is one of the important precursors of psoralen pathway that induced a maximum amount of psoralen with in vitro conditions.

OC-061 Rates Of Post Colonoscopy Colorectal Cancer (pccrc) Are Significantly Affected By Methodology, But Are Nevertheless Declining In The Nhs

IntroductionIt is recognised that post-colonoscopy colorectal cancer (PCCRC) can be due to missed cancer, or cancer arising from missed or incompletely removed polyps. Thus the rate of post-colonoscopy colorectal cancer...

Genetic divergence of tomato subsamples

Understanding the genetic variability of a species is crucial for the progress of a genetic breeding program and requires characterization and evaluation of germplasm. This study aimed to characterize and evaluate 101 tomato subsamples of the Salad group (fresh market) and two commercial controls, one of the Salad group (cv. Fanny) and another of the Santa Cruz group (cv. Santa Clara). Four experiments were conducted in a randomized block design with three replications and five plants per plot. The joint analysis of variance was performed and characteristics with significant complex interaction between control and experiment were excluded. Subsequently, the multicollinearity diagnostic test was carried out and characteristics that contributed to severe multicollinearity were excluded. The relative importance of each characteristics for genetic divergence was calculated by the Singh's method (Singh, 1981), and the less important ones were excluded according to Garcia (1998). Results showed large genetic divergence among the subsamples for morphological, agronomic and organoleptic characteristics, indicating potential for genetic improvement. The characteristics total soluble solids, mean number of good fruits per plant, endocarp thickness, mean mass of marketable fruit per plant, total acidity, mean number of unmarketable fruit per plant, internode diameter, internode length, main stem thickness and leaf width contributed little to the genetic divergence between the subsamples and may be excluded in future studies.

Definition of morpho-agronomic descriptors for the characterization of yellow passion fruit

A varietal description should help to resolve the conflicts of identification that may arise in the registration and protection of cultivars. The objective of this study was to evaluate the discriminatory capacity and to select minimum descriptors for the characterization and evaluation of yellow passion fruit varieties (Passiflora edulis Sims f. flavicarpa Deg.). Twenty quantitative and eight qualitative descriptors related to plant, leaves, flowers and fruits traits were analyzed in 24 genotypes of yellow passion fruit. The quantitative descriptors were subjected to a principal components analysis, and the selection of descriptors was based on direct selection and Singh method, whereas the qualitative descriptors were analyzed by correlation. Eight quantitative descriptors were discarded by direct selection, and seven were discarded using Singh method. However, only four descriptors common to both methods were considered to be redundant. Of the eight qualitative descriptors evaluated, two were discarded because they were correlated with the others. Therefore, the list of minimum descriptors to describe yellow passion fruit varieties can be composed of 22 descriptors, 16 quantitative and six qualitative, with a high contribution to the total variance and low correlation with the others. There was no loss of information with the elimination of those descriptors. In addition to the smaller number of descriptors providing valuable information, it will also allow a reduction in the labor, time and resources spent in the characterization of new varieties of yellow passion fruit.

Comparison of two sequential extraction procedures for the fractionation of zinc in agricultural calcareous soils

Twenty soil samples with a wide range of chemical and physical properties were collected from typical uncontaminated soils of south-west Iran, characterised by their high calcium carbonate contents (mean value of 321 g kg−1) and zinc deficiency (mean value of 0.2 mg kg−1 for DTPA-extractable Zn). The extractability and solid-phase fractionation of Zn in the soils was determined by the single extraction procedure (DTPA extractability) and two different sequential extraction procedures: a seven-step Singh method (procedure A) and the modification of three-step BCR (Community Bureau of Reference) method (procedure B). The DTPA extractable zinc levels were low (on average 3.34%). Zinc was mainly contained in the residual fraction (91.43% for procedure A and 75.25% for procedure B). In comparison with procedure B, few relationships were established between the zinc fractions isolated by procedure A and the soil properties. The Singh scheme provided better information than the BCR scheme about Zn distribution in the soils studied.

Características anatômicas e morfofisiológicas de lâminas foliares de genótipos de Panicum maximum

O objetivo deste trabalho foi avaliar as características anatômicas e morfofisiológicas de lâminas foliares de genótipos de Panicum maximum e determinar quais as mais relevantes para a discriminação precoce do valor nutritivo de genótipos promissores. O experimento foi realizado entre janeiro de 2006 e novembro de 2007, em Dourados, MS. Foram avaliados 23 genótipos de P. maximum pré-selecionados do programa de melhoramento da Embrapa Gado de Corte. Utilizou-se o delineamento experimental de blocos ao acaso, com três repetições. Foram avaliadas 27 características anatômicas e morfofisiológicas de lâminas foliares em cada genótipo. Para cada característica estudada, os resultados foram agrupados pelo teste de Scott-Knott. A importância relativa das características avaliadas para a avaliação da divergência genética foi determinada pelo método de Singh. As características que melhor discriminaram os genótipos foram as proporções - na seção transversal das lâminas - das epidermes adaxial, abaxial, adaxial + abaxial, do mesofilo e do tecido vascular + esclerênquima. A área foliar específica, a área foliar e o comprimento de lâmina foram as características morfofisiológicas que mais contribuíram para a discriminação dos genótipos; porém, sua importância relativa foi muito menor que a das características anatômicas. A proporção ocupada pela bainha parenquimática dos feixes e a largura das lâminas apresentam instabilidade fenotípica.

A new algorithm for optimum tolerance allocation of complex assemblies with alternative processes selection

Allocating tolerance to sub-components of a complex assembly with alternative processes selection by using Lagrange’s multiplier method is tedious as well as difficult. The present work is aims to solve the problem with simple effort in three stages. In the first stage, the maximum of two processes are selected from the alternative processes of each component and these two processes correspond to the smaller sum of difference in manufacturing cost. A hybrid optimum tolerance allocation method is developed in a second and third stage by combining Tabu search (TS) and heuristic approach. Application of the proposed algorithm is demonstrated on complex tolerancing products like knuckle joint and wheel mounting assembly. For the same manufacturing conditions, compared with tolerance synthesis by Singh method, the proposed method saved nearly $74,880 and $479,520, respectively, per year in manufacturing costs of knuckle joint and wheel mounting assembly.

Landslide Hazard and Risk Assessment on the Northern Slope of Mt. Changbai, China

Abstract: Landslide hazard and risk assessment on the northern slope of Mt. Changbai, a well‐known tourist attraction near the North Korean‐Chinese border, are assessed. This study is divided into two parts, namely, landslide hazard zonation and risk assessment. The 1992 Anbalagan and Singh method of landslide hazard zonation (LHZ) was modified and used in this area. In this way, an Associative Analysis Method was used in representative areas to get a measure for controlling factors (slope gradient, relative relief, vegetation, geology, discontinuity development, weak layer thickness and ground water). For the membership degree of factor to slope failure, the middle range of limited values was used to calculate LHZ. Based on an estimation of the potential damage from slope failure, a reasonable risk assessment map was obtained using the relationship of potential damage and probable hazard to aid future planning and prediction and to avert loss of life.

Divergência genética entre acessos de tomateiro infestados por diferentes populações da traça-do-tomateiro

Neste trabalho estudou-se a divergência genética entre acessos de Lycopersicon spp. com relação à resistência a populações da traça-do-tomateiro, Tuta absoluta, e verificou-se a importância relativa dos caracteres da traça-do-tomateiro para a divergência. Foi conduzido experimento envolvendo quatro populações do inseto procedentes de Uberlândia (MG), Viçosa (MG), Camocim de São Félix (PE) e Santa Teresa (ES) e cinco acessos de tomateiro, 'Santa Clara', 'Moneymaker', TOM-601, PI 126445 (L. hirsutum f. typicum) e PI 134417 (L. hirsutum f. glabratum). Foram realizados testes de médias de Tukey e método de agrupamento de Tocher, e verificada a importância relativa dos caracteres da traça-do-tomateiro para a divergência entre acessos por meio do método de Singh. Verificou-se a existência de variabilidade genética entre os acessos de tomateiro quando infestados pelas populações da traça-do-tomateiro provenientes das diferentes regiões do Brasil. O acesso Santa Clara foi o mais suscetível à população de Santa Teresa. 'Moneymaker' e 'TOM-601' foram mais resistentes às populações provenientes de Camocim de São Félix e Santa Teresa, respectivamente. PI 126445 foi mais resistente às populações de Santa Teresa e Viçosa. PI 134417 foi mais resistente à população de Viçosa. 'Moneymaker' e TOM-601 mostraram-se boas fontes a serem utilizadas em programas de melhoramento que visem à obtenção de cultivars de tomate resistentes à traça-do-tomateiro. Os caracteres que mais contribuíram para a divergência entre os acessos de tomateiro foram mortalidade larval, número de pupas fêmea e número de pupas macho. Os caracteres período larval e peso de pupas macho não podem ser eliminados em futuras avaliações de resistência à população da traça-do-tomateiro proveniente de Uberlândia.

Avaliação de caracteres morfológicos úteis na identificação de plantas poliplóides de melancia

Visando ao estudo da variação quantitativa de caracteres morfológicos em genótipos diplóides, triplóides e tetraplóides de melancia [Citrullus lanatus (Thunb.) Matsum. & Nakai], três linhagens diplóides, três linhagens tetraplóides e três híbridos triplóides foram avaliados quanto ao número de cloroplastos por estômato foliar (NCF); largura e comprimento foliar (LFH e CFH); relação largura/comprimento foliar (LF/CF); diâmetro de caule (DCE); diâmetro da corola em flores masculinas e femininas (DCM e DCF); diâmetro do ovário (DOV); peso de fruto (PMF), diâmetro transversal e longitudinal de fruto (DTF e DLF); relação diâmetro transversal/diâmetro longitudinal (DT/DL) e espessura média da casca (EMC). Foi utilizado delineamento de blocos casualizados com três repetições e parcelas de cinco plantas. Realizou-se análise univariada, segundo o modelo hierárquico, considerando-se o nível de ploidia como o fator principal. Os genótipos foram agrupados em dendrograma baseado na distância generalizada de Mahalanobis e também dispostos em um plano cartesiano, utilizando-se os escores das duas primeiras variáveis canônicas. A contribuição relativa das variáveis para a composição dos grupos de divergência foi estimada por meio do método de Singh e a matriz de correlação foi obtida utilizando a análise de componentes principais. O NCF apresentou maior importância relativa (41%) para a formação dos grupos de divergência, enquanto, os caracteres DMF, EMC e PMF apresentaram contribuição inferior a 1,0%. As variáveis NCF, LF/CF, DCP, DCF, DCM, DOV e DT/DL, analisadas conjuntamente, mostraram-se eficientes para a discriminação de plantas diplóides, triplóides e tetraplóides, e, portanto são recomendadas para auxiliar nos programas de melhoramento de melancia, que visem à obtenção de plantas poliplóides.

Divergência genética e subcoleção representativa de populações da traça-do-tomateiro

O objetivo deste trabalho foi estudar a divergência genética e propor uma subcoleção representativa da traça-do-tomateiro, Tuta absoluta (TDT). O experimento foi conduzido com quatro populações do inseto procedentes de Uberlândia, MG, Viçosa, MG, Camocim de São Félix, PE, e Santa Teresa, ES, e cinco acessos de tomateiro, 'Santa Clara', 'Moneymaker', TOM-601, PI 126445 (Lycopersicon hirsutum f. typicum) e PI 134417 (L. hirsutum f. glabratum). Foi realizada análise de agrupamento (método de Tocher, usando a distância de Mahalanobis como medida de dissimilaridade) e verificada a importância relativa dos caracteres da TDT para a divergência genética entre populações por meio do método de Singh. As populações de cada grupo obtido pela análise de agrupamento foram combinadas e, para cada caráter, foi realizado o teste t de Student para uma média. Existe variabilidade genética entre populações da TDT provenientes de diferentes localidades do Brasil, quando estão infestando Lycopersicon spp. A mortalidade larval teve maior contribuição para a divergência genética entre as populações, com exceção de PI 134417, cujo caráter de maior contribuição foi o número de pupas fêmeas. Propõe-se uma subcoleção da TDT tomando-se por base a combinação das populações de Santa Teresa e Uberlândia.

Genetic diversity analysis of peppers: a comparison of discarding variable methods

There are a lot of variables in genetic diversity studies, and it is necessary to know whether or not they are all important and which ones can be discarded. There are often little changes in clustering patterns if a subset of these variables is used, because the discarded variables are redundant or of little contribution to the variability. This study aimed at comparing two discards of variables methods – the Singh method and the principal components method – as well as evaluating the effect of the discards on the cluster analysis. In this analysis data of six ripe fruits traits were used. Other characters with previously known variability or collinearity were added to the analysis. The method considered being the most efficient was the one, which indicated variables that did not alter the initial clustering pattern when discarded. The Singh method did not detect variation differences when standardized data were used. When the distance was obtained by the non-standardized data, the pericarp thickness (0.018%), total soluble solids (0.1668%) and minimum width (2.99%) had the lowest contribution to the divergence. The principal components pointed out that the characteristics fruit length, total soluble solids and seeds yield/fruit were considered as dispensable variables. There were changes in the initial clustering pattern when the variable pericarp thickness was discarded, and the Singh method was not efficient in detecting the importance of this variable. There were no changes in the initial clustering pattern when fruit length was discarded. The data showed that the two compared methods differed, since Singh’s and principal component methods showed different variables to be discarded. The Singh method was not efficient in detecting multicollinearity among variables. The principal component method was more efficient in pointing out the variables that can be discarded. It is advisable that the genetic divergence is calculated based on the scores of the principal components. In future studies, when there is no replicated data, the genetic divergence and the pinpoint of characters should be calculated based on the principal component scores to avoid discarding some important variables when determining divergence. However, if the variable values differ independently, the Singh method based on Euclidean distance is appropriate.

A new stochastic randomized response model

The collection of data through personal interview surveys on sensitive issues such as induced abortions, drug abuse and family income is a serious issue in social sciences. Warner (1965) was the first to propose an ingenious method to collect information on such questions without disclosing the privacy of the respondents, which is called randomized response technique. In the present investigation, a new stochastic randomized response technique is proposed that elicits greater cooperation from the respondents, and can be made more efficient than Warner's (1965) and Mangat and Singh (1990) method by selecting certain parameters of the proposed randomization device.

Pattern of bone loss of the proximal femur: A radiologic, densitometric, and histomorphometric study

The pattern of bone loss in the proximal femur was studied in 141 cadaveric femora from 36 women and 39 men ranging from 27 to 89 years of age. Bone mineral density (BMD) of the femoral neck, greater trochanter, Ward's triangle, and tensile and compressive stress regions were measured by dual photon absorptiometry. Radiographs were graded by Singh's method. Histomorphometry of tensile and compressive trabecular areas was performed on ground midsection of the methylmethacrylate-embedded whole proximal femur. Although Singh index had some correlation with BMD of the femoral neck, the various BMD measurements showed that all regions lost bone to the same extent; in particular, no selective bone loss was found at low stress regions (tensile trabeculae or Ward's triangle). Histomorphometry revealed that most of the trabecular bone loss of the proximal femur is attributable to a decrease in thickness of individual trabeculae.

Serotonin-storing cells of the chicken duodenum: light, fluorescence and electron microscopy, and immunohistochemistry.

In an attempt to identify duodenal endocrine cells emitting formaldehyde-induced fluorescence (FIF), chicken duodena were studied by combined fluorescence, ultrastructural, silver impregnation and immunohistochemical methods in the same or consecutive sections. Our results show that: (1) Almost all the cells emitting yellow fluorescence by both the Falck-Hillarp and the Furness methods exhibit an immunohistochemical reaction with serotonin (5-HT) antiserum. (2) Almost all cells radiating yellow fluorescence by the Furness method stain with toluidine blue in Epon-embedded sections, but, by high-voltage electron microscopy, can be subdivided into two types of cell containing either small round or polymorphous types of granules. (3) In the sections from which resin had been removed, all the cells emitting yellow FIF show argentaffinity by the Singh method, but not all cells display argyrophilia with the Grimelius method. (4) Cells exhibiting both argyrophil and argentaffin reactions in deresined serial sections are also separated into two types of cell, containing either small spherical or polymorphous types of granules by conventional electron microscopy in thin sections. Therefore, chicken enterochromaffin cells emit yellow FIF, store 5-HT, show both argentaffinity and argyrophilia, but are ultrastructurally classified into two types of granule-containing cells which may be related to polypeptides coexisting with 5-HT.

A comparison of some lower bounds for eigenvalues of Schrodinger's equation

A method proposed recently by Singh (1981) of finding lower bounds to the eigen-energies of Schrodinger's equation is reviewed and compared with the methods of Bazley and Fox (1961) and of Lowdin (1965). Numerical results for an anharmonic oscillator suggest that the Singh method is less accurate than the others, but unlike the Lowdin single bracketing function technique does not suffer from any eigenvalue ordering problems.