Morphological variation between non‐native lake‐ and stream‐dwelling pumpkinseed Lepomis gibbosusin the Iberian Peninsula

The objective of this study was to test if morphological differences in pumpkinseed Lepomis gibbosus found in their native range (eastern North America) that are linked to feeding regime, competition with other species, hydrodynamic forces and habitat were also found among stream‐ and lake‐ or reservoir‐dwelling fish in Iberian systems. The species has been introduced into these systems, expanding its range, and is presumably well adapted to freshwater Iberian Peninsula ecosystems. The results show a consistent pattern for size of lateral fins, with L. gibbosus that inhabit streams in the Iberian Peninsula having longer lateral fins than those inhabiting reservoirs or lakes. Differences in fin placement, body depth and caudal peduncle dimensions do not differentiate populations of L. gibbosus from lentic and lotic water bodies and, therefore, are not consistent with functional expectations. Lepomis gibbosus from lotic and lentic habitats also do not show a consistent pattern of internal morphological differentiation, probably due to the lack of lotic–lentic differences in prey type. Overall, the univariate and multivariate analyses show that most of the external and internal morphological characters that vary among populations do not differentiate lotic from lentic Iberian populations. The lack of expected differences may be a consequence of the high seasonal flow variation in Mediterranean streams, and the resultant low‐ or no‐flow conditions during periods of summer drought.     

Peculiar H+ Homeostasis of Saccharomyces cerevisiae during the Late Stages of Wine Fermentation

Intracellular pH (pH(in)) is a tightly regulated physiological parameter, which controls cell performance in all living systems. The purpose of this work was to evaluate if and how H(+) homeostasis is accomplished by an industrial wine strain of Saccharomyces cerevisiae while fermenting real must under the harsh winery conditions prevalent in the late stages of the fermentation process, in particular low pH and high ethanol concentrations and temperature. Cells grown at 15, 25, and 30°C were harvested in exponential and early and late stationary phases. Intracellular pH remained in the range of 6.0 to 6.4, decreasing significantly only by the end of glucose fermentation, in particular at lower temperatures (pH(in) 5.2 at 15°C), although the cells remained viable and metabolically active. The cell capability of extruding H(+) via H(+)-ATPase and of keeping H(+) out by means of an impermeable membrane were evaluated as potential mechanisms of H(+) homeostasis. At 30°C, H(+) efflux was higher in all stages. The most striking observation was that cells in late stationary phase became almost impermeable to H(+). Even when these cells were challenged with high ethanol concentrations (up to 20%) added in the assay, their permeability to H(+) remained very low, being almost undetectable at 15°C. Comparatively, ethanol significantly increased the H(+) permeability of cells in exponential phase. Understanding the molecular and physiological events underlying yeast H(+) homeostasis at late stages of fermentations may contribute to the development of more robust strains suitable to efficiently produce a high-quality wine.     

Degradation of difluorobenzenes by the wild strain Labrys portucalensis

This study focuses on the biodegradation of difluorobenzenes (DFBs), compounds commonly used as intermediates in the industrial synthesis of various pharmaceutical and agricultural chemicals. A previously isolated microbial strain (strain F11), identified as Labrys portucalensis, able to degrade fluorobenzene (FB) as sole carbon and energy source, was tested for its capability to degrade 1,2-, 1,3- and 1,4-DFB in batch cultures. Strain F11 could use 1,3-DFB as a sole carbon and energy source, with quantitative release of fluoride, but 1,4-DFB was only degraded and defluorinated when FB was supplied simultaneously. Growth of strain F11 with 0.5 mM of 1,3-DFB led to stoichiometric release of fluoride ion. The same result was obtained in cultures fed with 1 mM of 1,3-DFB or 0.5 mM of 1,4-DFB, in the presence of 1 mM of FB. No growth occurred with 1,2-DFB as substrate, and degradation of FB was inhibited when supplied simultaneously with 1,2-DFB. To our knowledge, this is the first time biodegradation of 1,3-DFB as a sole carbon and energy source, and cometabolic degradation of 1,4-DFB, by a single bacterium, is reported.     

Quality of life and radiotherapy in brain metastasis patients

AimThe primary objective of this study was to assess whether there was an improvement in QoL for patients with brain metastases after radiotherapy treatments.BackgroundAssessment of quality of life (QoL) in brain metastasis patients has become increasingly recognized as an important outcome.Materials and methodsPatients treated for brain metastasis in our department during 2010 were included in our prospective study. QoL assessments were conducted at baseline, 1 month, and 3 months after completion of whole-brain radiotherapy (WBRT). Wilcoxon test for multiple comparisons was calculated to detect significant differences in global QoL scores.ResultsThirty-nine patients with brain metastases completed the EORTC QLQ-C30/BN-20 questionnaire independently. Median age was 59.9 years (from 37 to 81 years). Our results report differences between the baseline and 3 months in worsening of a global health status (p = 0.034) and cognitive function (p = 0.004), as well as drowsiness (p = 0.001), appetite loss (p = 0.031) and hair loss (p = 0.005). There is a tendency for deterioration of physical function (p = 0.004), communication deficit (p = 0.012), and weakness of legs (p = 0.024), between the baseline and 1 month evaluation. There was no difference in a global cognitive status between different evaluations. Median survival time was 3 months (CI 95% 1.85; 4.15).ConclusionsOur findings indicate a small deterioration for a global QoL status, and large deterioration for cognitive function after radiation treatments, as well as worsening of brain metastasis related symptom items. Further research is necessary to refine treatment selection for patients with brain metastases, since it may at least contribute to the stabilization of their QoL status.     

Crystal Structure of ATVORF273, a New Fold for a Thermo- and Acido-Stable Protein from the Acidianus Two-Tailed Virus

Acidianus two-tailed virus (ATV) infects crenarchaea of the genus Acidianus living in terrestrial thermal springs at extremely high temperatures and low pH. ATV is a member of the Bicaudaviridae virus family and undergoes extra-cellular development of two tails, a process that is unique in the viral world. To understand this intriguing phenomenon, we have undertaken structural studies of ATV virion proteins and here we present the crystal structure of one of these proteins, ATV. ATV forms tetramers in solution and a molecular envelope is provided for the tetramer, computed from small-angle X-ray scattering (SAXS) data. The crystal structure has properties typical of hyperthermostable proteins, including a relatively high number of salt bridges. However, the protein also exhibits flexible loops and surface pockets. Remarkably, ATV displays a new protein fold, consistent with the absence of homologues of this protein in public sequence databases.     

Mitochondrial function in Parkinson's disease cybrids containing an nt2 neuron-like nuclear background

Mitochondria likely play a role in Parkinson's disease (PD) neurodegeneration. We modelled PD by creating cytoplasmic hybrid (cybrid) cell lines in which endogenous mitochondrial DNA (mtDNA) from PD or control subject platelets was expressed within human teratocarcinoma (NT2) cells previously depleted of endogenous mtDNA. Complex I activity was reduced in both PD cybrid lines and in the platelet mitochondria used to generate them. Under basal conditions PD cybrids had less ATP, more LDH release, depolarized mitochondria, less mitochondrial cytochrome c, and higher caspase 3 activity. Equivalent MPP+ exposures are more likely to trigger programmed cell death in PD cybrid cells than in control cybrid cells. Our data support a relatively upstream role for mitochondrial dysfunction in idiopathic PD.     

Comparative Study of Chemical Approaches to the Solid-Phase Synthesis of a Tumor-Seeking α-MSH Analogue

The synthesis of a cyclic melanocortin analogue (H-pz-βAla-Nle-cyclo[Asp-His-DPhe-Arg-Trp-Lys]-NH₂), where the Boc-protected derivative of a metal-chelating pyrazolyl ligand (pz) was inserted as N-terminal residue, was addressed by several different Fmoc/tBu and Boc/Bzl solid-phase strategies. On-resin cyclization was achieved immediately following incorporation of Asp, by condensation of the Asp side chain carboxyl with the Lys side chain primary amine after selective and simultaneous removal of side chain protecting groups. The success of the synthesis was highly dependent on the chemical strategy employed, with Boc/Bzl chemistry giving the best results. On the light of our findings, Fmoc/tBu strategies are not advantageous for the solid-phase synthesis of this particular type of lactam-bridged peptides. Last, but not least, the target peptide was recently found to have promising tumor-seeking properties (J Biol Inorg Chem 13:449–459, 2008).     

Towards expanding relevance vector machines to large scale datasets

In this paper we develop and analyze methods for expanding automated learning of Relevance Vector Machines (RVM) to large scale text sets. RVM rely on Bayesian inference learning and while maintaining state-of-the-art performance, offer sparse and probabilistic solutions. However, efforts towards applying RVM to large scale sets have met with limited success in the past, due to computational constraints. We propose a diversified set of divide-and-conquer approaches where decomposition techniques promote the definition of smaller working sets that permit the use of all training examples. The rationale is that by exploring incremental, ensemble and boosting strategies, it is possible to improve classification performance, taking advantage of the large training set available. Results on Reuters-21578 and RCV1 are presented, showing performance gains and maintaining sparse solutions that can be deployed in distributed environments.