Extracting samples of high diversity from thematic collections of large gene banks using a genetic-distance based approach.

Background Breeding programs are usually reluctant to evaluate and use germplasm accessions other than the elite materials belonging to their advanced populations. The concept of core collections has been proposed to facilitate the access of potential users to samples of small sizes, representative of the genetic variability contained within the gene pool of a specific crop. The eventual large size of a core collection perpetuates the problem it was originally proposed to solve. The present study suggests that, in addition to the classic core collection concept, thematic core collections should be also developed for a specific crop, composed of a limited number of accessions, with a manageable size. Results The thematic core collection obtained meets the minimum requirements for a core sample - maintenance of at least 80% of the allelic richness of the thematic collection, with, approximately, 15% of its size. The method was compared with other methodologies based on the M strategy, and also with a core collection generated by random sampling. Higher proportions of retained alleles (in a core collection of equal size) or similar proportions of retained alleles (in a core collection of smaller size) were detected in the two methods based on the M strategy compared to the proposed methodology. Core sub-collections constructed by different methods were compared regarding the increase or maintenance of phenotypic diversity. No change on phenotypic diversity was detected by measuring the trait "Weight of 100 Seeds", for the tested sampling methods. Effects on linkage disequilibrium between unlinked microsatellite loci, due to sampling, are discussed. Conclusions Building of a thematic core collection was here defined by prior selection of accessions which are diverse for the trait of interest, and then by pairwise genetic distances, estimated by DNA polymorphism analysis at molecular marker loci. The resulting thematic core collection potentially reflects the maximum allele richness with the smallest sample size from a larger thematic collection. As an example, we used the development of a thematic core collection for drought tolerance in rice. It is expected that such thematic collections increase the use of germplasm by breeding programs and facilitate the study of the traits under consideration. The definition of a core collection to study drought resistance is a valuable contribution towards the understanding of the genetic control and the physiological mechanisms involved in water use efficiency in plants

Metagenômica e sua aplicação no estudo de diversidade e função de microrganismos de solos do Cerrado.

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Lumbosacral column arthtodesis with a system's implant

Lumbosacral column arthrodesis with bone graft and metallic fixation (A-Systems implant) was carried out in 40 patients with spondylolisthesis and lumbosacral instability of the following types: isthmic-lytic in 13, degenerative in 19, traumatic in 2, pathological in 1, and surgical in 5. Preoperative, immediate postoperative, and late postoperative clinical and radiological evaluation was carried out. Clinical follow-up ranged from 10 to 46 months (mean follow-up: 11 months). Patient's and Physician's overall evaluation showed the following results: good results in 36 (39%) patients; improvement as compared to preoperative condition in 3 (7.5%); unchanged condition in 1 (2.5%); normalized labor capability in 29 (72.5%) patients; improvement of 75% in labor capability in 9 (22.5%) patients; and improvement of 50% in 2 (5%) patients. As for the Prolo rate, an increase to 9-10 (excellent) was seen in 21 (52.5%) patients; an increase to 7 and 8 (good) was seen in 14 (35%); an increase to 5 to 6 (moderate) was found in 5 (12.5%) patients. No patient had a Prolo rate of 2, 3, or 4 (poor). Mean time until return to normal activities ranged from 3 to 12 months (mean: 7 months). As compared to similar methods reported in literature, the implant has been shown to be equaally effective, with the following advantages: simplicity, use at different levels; rigidity following assembly.Foram avaliados 40 pacientes com espondilolistese e instabilidade lombossacra: 13 pacientes do tipo ístmica-lítica, 19 do tipo degenerativa, 2 pacientes do tipo traumática, 1 tipo do patológica, e 5 do tipo cirúrgica, nos quais foram realizadas 40 artrodeses da coluna lombossacra com enxerto ósseo e fixação metálica com o implante A-Systems. A avaliação dos pacientes foi realizada clínica e radiograficamente, nos períodos pré-operatório, pós-operatório imediato e pós-operatório tardio. O tempo de acompanhamento clínico máximo foi de 46 meses, o mínimo de 10 meses, obtendo-se um acompanhamento médio de 11 meses. A avaliação global tanto do ponto vista do paciente como da equipe médica mostrou que: 36 (90%) dos pacientes obtiveram bom resultado; três pacientes (7,5%) apresentaram melhora em relação ao pré-operatório e um paciente (2,5%) não obteve melhora. Vinte e nove pacientes (72,5%) tiveram sua capacidade de trabalho normalizada, nove (22,5%) pacientes tiveram sua capacidade melhorada em 75% e dois (5%) pacientes tiveram a capacidade melhorada em 50%. Vinte e um pacientes (52,5%) tiveram o índice de Prolo aumentado entre 9 e 10 (excelente); 14 (35%) tiveram índice de Prolo aumentado para 7 e 8 (bom); em 5 (12,5%) o índice ficou entre 5 e 6 (regular) e nenhum paciente teve índice 2, 3 ou 4 (mau). O tempo médio de retorno para as atividades normais variou de três a doze meses, com uma média de sete meses. Em comparação com métodos similares relatados pela literatura, o implante mostrou-se tão eficiente quanto eles, com as vantagens da simplicidade, da possibilidade de ser usado em vários níveis e da rigidez após montado.Pontíficia Universidade Católica do Rio Grande do Sul Hospital São Lucas Serviço de Ortopedia e TraumatologiaUniversidade de São Paulo Faculdade de MedicinaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Ortopedia e TraumatologiaUNIFESP, EPM, Depto. de Ortopedia e TraumatologiaSciEL

Coupling in-depth genome annotations with genome editing technology for harnessing genomic variation to promote precision breeding in tropical soybean.

ABSTRACT: Directional selection during crop domestication and advanced breeding has resulted in significant changes in plant genomes. The extent of intraspecific variation in a crop documents domestication and highlights variants underlying complex traits. Studies demonstrate that most naturally occurring variants in crops are low frequency, and only a small fraction of those might have important functions to trait variation. To understand the inheritance of quantitative traits, diversity panels have become available by crossing inbred lines to produce genomic maps that relate phenotypic variation to recombination and ultimately to genome structure. Using these resources, genomics studies have suggested that selection performs poorly in pericentromeric regions because of reduced recombination frequency (RF). Thus, manipulating RF and meiotic crossover location is an appealing issue to advance crop breeding. In our study, we are using genomic analysis to characterize intragenomic diversity of tropical elite soybean lines in terms of heterozygosity, RF, chromatin structure and accessibility. Our results to date include the generation of draft genome assemblies for two soybean advanced lines using PACBIO long-read sequencing, Chromium Linked-Reads sequencing and an approach rooted in polymer physics that determines the most likely genome structure using chromosomal contact data. In-depth genome-wide characterization is ongoing using ATAC-Seq and Parent-Progeny resequencing. We also present our efforts to apply DNA-free editing tools in implementing genetic alterations that are expected to engineer desirable traits in soybeans by modifying meiotic specific expression. These changes are expected to increase genetic and epigenetic variations with favorable outcomes in seed oil and protein pathway regulation. Financial support: Embrapa-Monsanto Fund/Project:03.17.03.002.00.0

Delirium in Hospitalized Elderly Patients and Post-Discharge Mortality

OBJECTIVE: To determine the impact of delirium on post-discharge mortality in hospitalized older patients. INTRODUCTION: Delirium is frequent in hospitalized older patients and correlates with high hospital mortality. There are only a few studies about its impact on post-discharge mortality. METHODS: This is a prospective study of patients over 60 years old who were hospitalized in the Geriatric Unit at Hospital das Clínicas of São Paulo between May 2006 and March 2007. Upon admission, demographics, comorbidities, number of drugs taken, and serum albumin concentration were evaluated for each patient. Delirium was diagnosed according to the DSM-IV criteria. Patients were divided into group A (with delirium) and group B (without delirium). One year after discharge, the patients or their caregivers were contacted to assess days of survival. RESULTS: The sample included 199 patients, 66 (33%) of whom developed delirium (Group A). After one year, 33 (50%) group A patients had died, and 45 (33.8%) group B patients had died (p = 0.03). There was a significant statistical difference in average age (p = 0.001) and immobility (p <0.001) between groups A and B. There were no statistically significant differences between groups A and B in number of drugs taken greater than four (p = 0.62), sex (p = 0.54) and number of diagnoses greater than four (p = 0.21). According to a multivariate analysis, delirium was not an independent predictor of post-discharge mortality. The predictors of post-discharge mortality were age > 80 years (p = 0.029), albumin concentration < 3.5 g/dl (p = 0.001) and immobility (p = 0.007). CONCLUSION: Delirium is associated with higher post-discharge mortality as a dependent predictor