Características físicas e químicas de frutos de pupunheira no estado do Pará.

O objetivo deste estudo foi caracterizar física e físico-quimicamente frutos de 21 matrizes de pupunheira (Bactris gasipaes Kunth), visando a obter subsídios que permitam avançar com o programa de melhoramento genético, em especial para características da polpa do fruto. Os frutos provenientes de diferentes genótipos foram caracterizados quanto à dimensão dos frutos e caroço, umidade, proteínas, lipídeos, cinzas, fibras e carotenoides totais. Os resultados obtidos para as diferentes variáveis analisadas demonstraram diferenças entre os frutos obtidos de diferentes genótipos. A análise de proteínas apresentou valores que variaram de 4,20 a 6,79%, com destaque para a matriz B04-P20, que apresentou o maior valor. Para lipídeos, os teores variaram bastante, com valores entre 8,25 e 40,83%, destacando-se a matriz B02-P30 com o maior teor de lipídeos. Os teores de carotenoides totais das matrizes de pupunheira variaram de 8,02 a 124,90µg/g, com destaque para as matrizes B02-P30 (124,90µg/g) e B05-P45 (123,04µg/g), indicando que a pupunha pode contribuir de maneira importante na ingestão de antioxidantes na dieta. De maneira geral, as análises físicas e físico-químicas dos frutos mostraram diferenças significativas entre as matrizes para os caracteres estudados, evidenciando ser um conjunto geneticamente promissor para a prática da seleçã

Latent cluster analysis of ALS phenotypes identifies prognostically differing groups

BACKGROUND Amyotrophic lateral sclerosis (ALS) is a degenerative disease predominantly affecting motor neurons and manifesting as several different phenotypes. Whether these phenotypes correspond to different underlying disease processes is unknown. We used latent cluster analysis to identify groupings of clinical variables in an objective and unbiased way to improve phenotyping for clinical and research purposes. METHODS Latent class cluster analysis was applied to a large database consisting of 1467 records of people with ALS, using discrete variables which can be readily determined at the first clinic appointment. The model was tested for clinical relevance by survival analysis of the phenotypic groupings using the Kaplan-Meier method. RESULTS The best model generated five distinct phenotypic classes that strongly predicted survival (p<0.0001). Eight variables were used for the latent class analysis, but a good estimate of the classification could be obtained using just two variables: site of first symptoms (bulbar or limb) and time from symptom onset to diagnosis (p<0.00001). CONCLUSION The five phenotypic classes identified using latent cluster analysis can predict prognosis. They could be used to stratify patients recruited into clinical trials and generating more homogeneous disease groups for genetic, proteomic and risk factor research

Pushing Taxonomy to Extiction?

Can we describe all species on Earth before they disappear? We argue that this is possible only by endowing taxonomy with professional manpower and appropriate material resources as required by big science. Contrary to Costello et al.’s (CMS) (1) statements, taxonomy is not an easy discipline accessible to all through a smartphone. It requires exhaustive training and long familiarity with field, specimens and literature (2). CMS’s argument is framed in terms of species numbers, but different, non-overlapping species concepts apply to bacteria, brambles and birds (3,4,5): “the species” as common unit of biodiversity does not exist (6). Even ignoring this conceptual and semantic issue, CMS’s estimates of undescribed biodiversity and extinction rates are based on insufficient evidence and poorly supported models. Biodiversity hotspots steadily emerge in geographic areas where diversity was long assumed to be largely described (7,8). The number of species, whatever species are, cannot be easily estimated because of the historical, rather than deterministic or teleological, nature of biological evolution (9,10). Extinction rates are highly context-sensitive (11), lineage- and region-dependant, thus generally difficult to ascertain (12) without thorough analyses of data such as IUCN’s estimates of threats and extinctions (13). However, evidence being mainly restricted to vertebrates, the extinction risks in most other groups remain terra incognita. Furthermore, recent surveys (14,15) do not support CMS’s optimistic predictions regarding extinction rates. CMS’s agenda emphasizes technology, voluntary work and recognition of subjective “morphospecies” (16). However, improvement of data storage and retrieval cannot substitute for the production of sound data. Serious taxonomists cannot describe two new species per week, as suggested by CMS’s calculations. Describing new species, even with the help of molecular data and especially in best-investigated groups, is increasingly demanding, following the “law of diminishing returns” (17). More than anything else, taxonomy requires professional manpower, unrestricted fieldwork and permanent collections

Taxonomic Review of South American Butter Frogs: Phylogeny, Geographic Patterns, and Species Delimitation in the Leptodactylus latrans Species Group (Anura: Leptodactylidae)

The Leptodactylus latrans species group currently comprises eight medium- to large-sized frog species with a convoluted taxonomic history, particularly related to the specific limits of the L. latrans complex, and the species pair Leptodactylus chaquensis–Leptodactylus macrosternum. Their homogeneous external morphology and continental geographic distribution in South America have posed severe limitations to a comprehensive review, such that taxonomic consensus and species limits remain uncertain. This is further worsened by the presence of chromatic polymorphism among coexisting species that can hardly be distinguished by external morphology. Based on a large-scale geographic sampling including multilocus DNA analyses, and acoustic and morphological data, we provide a comprehensive evaluation of the taxonomic status and species limits of the L. latrans group, focusing on the resolution of the L. latranscomplex and the species pair L. chaquensis–L. macrosternum. We gathered 728 mitochondrial sequences from 429 localities, encompassing the entire geographic distribution of the group. Both generalized mixed Yule coalescent and automatic barcode gap discovery species delimitation methods recovered four major mitochondrial evolutionary lineages within the L. latrans complex, also supported by distribution patterns, multilocus molecular, morphological and/or bioacoustic data. One lineage is linked to nominal L. latrans,one revalidated as Leptodactylus luctator, and the other two are formally named and described. Another lineage encompasses all specimens previously assigned to the species pair L. chaquensis–L. macrosternum, clustered as a single evolutionary entity and is now regarded as L. macrosternum. We provide a revised diagnosis for these species based on acoustic data, morphological/chromatic variation, and phylogenetic relationships of all species currently included in the L. latrans group. Our findings reinforce the view that Neotropical diversity is highly underestimated and stress that appropriate geographic sampling in an integrative framework is crucial for the establishment of specific limits among broadly distributed and morphologically cryptic Neotropical frogs

Biaxial stress ring applications to magneto-optical studies of semiconductor films

We present a magneto-optical system to study semiconductor heterostructures in the presence of an external biaxial tensile strain. The pressure cell is based on the deflection of a plate (the sample) placed between a sphere and a ring. This externally applied stress is easily controlled and can achieve a deformation of up to similar to0.25% for GaAs films. This device is very useful for band structure study and optical resonance experiments in heterostructures. We also present the application of the device to study the behavior of the magneto-excitons in InP epitaxial layer as a function of the biaxial strain. We observed that the diamagnetic and Zeeman effects in InP films are affected by the biaxial tensile strain. (C) 2004 American Institute of Physics.7561947195

Plasmodium falciparum isolates from Angola show the StctVMNT haplotype in the pfcrt gene

<p>Abstract</p> <p>Background</p> <p>Effective treatment remains a mainstay of malaria control, but it is unfortunately strongly compromised by drug resistance, particularly in <it>Plasmodium falciparum</it>, the most important human malaria parasite. Although <it>P. falciparum </it>chemoresistance is well recognized all over the world, limited data are available on the distribution and prevalence of <it>pfcrt </it>and <it>pfmdr1 </it>haplotypes that mediate resistance to commonly used drugs and that show distinct geographic differences.</p> <p>Methods</p> <p><it>Plasmodium falciparum</it>-infected blood samples collected in 2007 at four municipalities of Luanda, Angola, were genotyped using PCR and direct DNA sequencing. Single nucleotide polymorphisms in the <it>P. falciparum pfcrt </it>and <it>pfmdr1 </it>genes were assessed and haplotype prevalences were determined.</p> <p>Results and Discussion</p> <p>The most prevalent <it>pfcrt </it>haplotype was <b>S</b>_tctVMN<b>T </b>(representing amino acids at codons 72-76). This result was unexpected, since the <b>S</b>_tctVMN<b>T </b>haplotype has previously been seen mainly in parasites from South America and India. The CV<b>IET</b>, CVMN<b>T </b>and CV<b>I</b>N<b>T </b>drug-resistance haplotypes were also found, and one previously undescribed haplotype (CVM<b>DT</b>) was detected. Regarding <it>pfmdr1</it>, the most prevalent haplotype was <b>Y</b>EYSNVD (representing amino acids at codons 86, 130, 184, 1034, 1042, 1109 and 1246). Wild haplotypes for <it>pfcrt </it>and <it>pfmdr1 </it>were uncommon; 3% of field isolates harbored wild type <it>pfcrt </it>(CVMNK), whereas 21% had wild type <it>pfmdr1 </it>(NEYSNVD). The observed predominance of the <b>S</b>_tctVMN<b>T </b>haplotype in Angola could be a result of frequent travel between Brazil and Angola citizens in the context of selective pressure of heavy CQ use.</p> <p>Conclusions</p> <p>The high prevalence of the <it>pfcrt </it><b>S</b>VMN<b>T </b>haplotype and the <it>pfmdr1 </it>86<b>Y </b>mutation confirm high-level chloroquine resistance and might suggest reduced efficacy of amodiaquine in Angola. Further studies must be encouraged to examine the <it>in vitro </it>sensitivity of <it>pfcrt </it><b>S</b>VMN<b>T </b>parasites to artesunate and amodiaquine for better conclusive data.</p

Molecular markers of antifolate resistance in Plasmodium falciparum isolates from Luanda, Angola

Abstract Background Plasmodium falciparum malaria remains a leading health problem in Africa and its control is seriously challenged by drug resistance. Although resistance to the sulphadoxine-pyrimethamine (SP) is widespread, this combination remains an important component of malaria control programmes as intermittent preventive therapy (IPT) for pregnant women and children. In Angola, resistance patterns have been poorly characterized, and IPT has been employed for pregnant women since 2006. The aim of this study was to assess the prevalence of key antifolate resistance mediating polymorphisms in the pfdhfr and pfdhps genes in P. falciparum samples from Angola. Methods Plasmodium falciparum samples collected in Luanda, in 2007, were genotyped by amplification and DNA forward and reverse sequencing of the pfdhfr and pfdhps genes. Results The most prevalent polymorphisms identified were pfdhfr 108N (100%), 51I (93%), 59R (57%) and pfdhps 437G (93%). Resistance-mediating polymorphisms in pfdhps less commonly observed in West Africa were also identified (540E in 10%, 581G in 7% of samples). Conclusion This study documents an important prevalence of 4 P. falciparum polymorphisms that predicts an antifolate resistance in Luanda. Further, some samples presented additional mutations associated to high-level resistance. These results suggest that the use of SP for IPT may no longer be warranted in Angola

Mechanical and structural characterization of tibial prosthetic interfaces before and after aging under simulated service conditions

Prosthesis interface is one of the most important components to promote individual's health and comfort, as it establishes direct contact with the skin and transfers loads generated during gait. The aim of this study was to mechanically characterize, three commercial interfaces (block copolymer, silicone gel and silicone elestomer), under static and dynamic conditions, before and after undergoing a process of chemical aging in synthetic sweat for periods up to 90 days. Static mechanical compression tests were performed on the materials, as well as fatigue tests to assess their static and dynamic mechanical behaviors, respectively. For the second, a sinusoidal load was applied with an appropriate range of deformation for each material. Several analytical techniques were also used to characterize the materials, namely Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), and morphology characterization by Scanning Electron Microscopy (SEM). All the tested materials have strong viscoelastic behavior, showing a linear response for small deformations, followed by a nonlinear behavior for higher deformation. The block copolymer and the silicone gel are affected by aging in synthetic sweat in a similar way, with a significant increase of their rigidity after 30 days, followed by a progressive reduction. The silicone elastomer displays a continuous increase of rigidity along the 90 days of storage, being the most sensitive to aging affects. It also exhibits the lowest stiffness value, being suitable for uses that require maximum comfort. All materials demonstrate chemical and structural stability under service simulated conditions. (C) 2014 Elsevier Ltd. All rights reserved