949 research outputs found
Cuentos de fantasmas. Persistencia espectral de los centros de detención y tortura chilenos
The detention and torture centres of the Chilean dictatorship have disappeared or are disappearing. The memories of these places also seem to be lost. We will argue here, however, that the physical disappearance of the places does not imply the loss of all traces, since their memory survives through other means, such as oral tradition. We explore, in particular, the possibility that it is the tales of supernatural activity, the so-called "ghost stories", that serve as the public stage for the social memory, allowing it to be summoned
Enhanced lithium depletion in Sun-like stars with orbiting planets
The surface abundance of lithium on the Sun is 140 times less than
protosolar, yet the temperature at the base of the surface convective zone is
not hot enough to burn Li. A large range of Li abundances in solar type stars
of the same age, mass and metallicity is observed, but theoretically difficult
to understand. An earlier suggestion that Li is more depleted in stars with
planets was weakened by the lack of a proper comparison sample of stars without
detected planets. Here we report Li abundances for an unbiased sample of
solar-analogue stars with and without detected planets. We find that the
planet-bearing stars have less than 1 per cent of the primordial Li abundance,
while about 50 per cent of the solar analogues without detected planets have on
average 10 times more Li. The presence of planets may increase the amount of
mixing and deepen the convective zone to such an extent that the Li can be
burned.Comment: 13 pages, 2 figure
A new pathway for Mannitol metabolism in yeasts suggests a link to the evolution of alcoholic fermentation
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.The yeasts belonging to the Wickerhamiella and Starmerella genera (W/S clade) share a distinctive evolutionary history marked by loss and subsequent reinstatement of alcoholic fermentation mediated by horizontal gene transfer events. Species in this clade also share unusual features of metabolism, namely the preference for fructose over glucose as carbon source, a rare trait known as fructophily. Here we show that fructose may be the preferred sugar in W/S-clade species because, unlike glucose, it can be converted directly to mannitol in a reaction with impact on redox balance. According to our results, mannitol is excreted to the growth medium in appreciable amounts along with other fermentation products such as glycerol and ethanol but unlike the latter metabolites mannitol production increases with temperature. We used comparative genomics to find genes involved in mannitol metabolism and established the mannitol biosynthesis pathway in W/S-clade species Starmerella bombicola using molecular genetics tools. Surprisingly, mannitol production seems to be so important that St. bombicola (and other W/S-clade species) deploys a novel pathway to mediate the conversion of glucose to fructose, thereby allowing cells to produce mannitol even when glucose is the sole carbon source. Using targeted mutations and 13C-labeled glucose followed by NMR analysis of end-products, we showed that the novel mannitol biosynthesis pathway involves fructose-6-phosphate as an intermediate, implying a key role for a yet unknown fructose-6-P phosphatase. We hypothesize that mannitol production contributed to mitigate the negative effects on redox balance of the ancient loss of alcoholic fermentation in the W/S clade. Presently, mannitol also seems to play a role in stress protection.info:eu-repo/semantics/publishedVersio
Vertical Distribution of Leaves and Stems on the Sward and Forage Intake by Lambs in Tifton-85 Pasture
Sward characteristics affect the performance of grazing livestock, especially for the youngest animals. The aim of this study was to evaluate the relationship between the vertical distribution of leaves and stems on the sward and the forage intake parameters of lambs in four sheep meat production systems grazing a Bermudagrass (Cynodon dactylon) cv. Tifton-85 pasture
Infraspecific variability in the essential oil composition of Lychnophora ericoides
Variations in the composition of the leaf essential oils of wild Lychnophora ericoides, with and without scent, which were grown in three sampling sites, were examined by GC-MS. Results were submitted to principal component and cluster analysis which allowed for two groups of essential oils to be distinguished with regard to scent: cluster I with specimens exhibiting an aromatic scent and containing a high percentage of α-bisabolol (34 ± 23%) and o-cymene (8.4 ± 6.9%); cluster II with specimens without any scent and characterised by a high percentage of caryophyllene oxide (11 ± 9%) and δ-elemene (5.7 ± 6.9%). The two types of oil coexist in all the populations under study, although patterns of aromatic samples deriving from Caldas Novas' State Park reveal chemical differences in relation to the samples from Brasília's National Park and Santo Antônio do Descoberto. Such chemical variations clearly suggest, apart from a geographical influence, genetic differences between individuals in the populations. The high content of α-bisabolol supports the folk medicinal use of arnica as anti-inflammatory
Human Bocavirus Infection in Children with Gastroenteritis, Brazil
Human bocavirus (HBoV) was detected in 14 (2%) of 705 fecal specimens from Brazilian children with gastroenteritis. Coinfection with rotavirus, adenovirus, or norovirus was found in 3 (21.4%) HBoV-positive specimens. None of the HBoV-positive patients had respiratory symptoms
Severity of Ascites Is Associated with Increased Mortality in Patients with Cirrhosis Secondary to Biliary Atresia
Very few prior studies have investigated the presence of ascites as a prognostic factor in children with cirrhosis. To the best of our knowledge, there are no prior studies evaluating the relationship between severity of ascites and patient survival in children with biliary atresia and cirrhosis.Clinically detectable ascites is associated with decreased 1-year survival of children with biliary atresia. These patients should be treated with caution and prioritized for liver transplantation.Background Very few prior studies have investigated the presence of ascites as a prognostic factor in children with cirrhosis.
To the best of our knowledge, there are no prior studies evaluating the relationship between severity of ascites and patient
survival in children with biliary atresia and cirrhosis.
Aims To evaluate the association between severity of ascites and survival of children with cirrhosis and biliary atresia.
Methods All children with cirrhosis secondary to biliary atresia evaluated at our institution from 2000 to 2014 were included
in this study. Patients were classified into four groups: NA = no ascites; A1 = grade 1 ascites; A2 = grade 2 ascites; and
A3 = grade 3 ascites. The primary endpoint of the study was mortality within the first year after patient inclusion. Ninetyday
mortality was also evaluated. Prognostic factors related to both endpoints also were studied. [...]info:eu-repo/semantics/publishedVersio
Purification of antileukemic drugs through silica-based supported ionic liquids
L-asparaginase (LA) is an enzyme used as a biopharmaceutical for the treatment of acute
lymphoblastic leukemia. LA can be produced via fermentation and its purification usually
comprises several steps including precipitation, liquid-liquid extraction and
chromatography techniques. Among these, ion exchange chromatography, which is often
preceded by precipitation with salts as a first pre-chromatographic step, is the most used.
However, theses common strategies for protein purification result in low yields and
purity, requiring long processing times, while leading to a consequent increase of the
process costs. Therefore, the demand for new cost-effective production/purification
processes play now a priority role.
This work aims the development of cost-effective technologies to purify LA from the
complex fermentation medium from Bacillus Subtillis. Silica-based supported ionic
liquids (SILs) are investigated as cost-effective purification materials for the target
enzyme. The concentration of the extract from the fermentation, material/ extract from
fermentation ratio and contact time effects in the purity and yield of LA were optimized.
With this strategy, process costs, energy consumed, and waste generated, may be
significantly decreased, which may lead to this biopharmaceutical price decrease and
wider application.publishe
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