The response of Carlos Botelho (Lobo, Broa) Reservoir to the passage of cold fronts as reflected by physical, chemical, and biological variables.

This paper describes and discusses the impacts of the passage of cold fronts on the vertical structure of the Carlos Botelho (Lobo-Broa) Reservoir as demonstrated by changes in physical, chemical, and biological variables. The data were obtained with a continuous system measuring 9 variables in vertical profiles in the deepest point of the reservoir (12 m) coupled with climatological information and satellite images, during a 32-day period in July and August, 2003. During periods of incidence of cold fronts the reservoir presented vertical mixing. After the dissipation of the cold fronts a period of stability followed with thermal, chemical, and biological (chlorophyll-a) stratification. Climatological data obtained during the cold front passage showed lower air temperature, higher wind speed and lower solar radiation. The response of this reservoir can exemplify a generalized process in all shallow reservoirs in the Southeast Brazil and could have several implications for management, particularly in relation to the phytoplankton population dynamics and development of cyanobacterial blooms. Using this as a basis, a predictive model will be developed with the aim of advancing management strategies specially for the drinking water reservoirs of the Metropolitan Region of S?o Paulo.     

Methane-fed microbial microcosms show differential community dynamics and pinpoint taxa involved in communal response

We report observations on the dynamics of bacterial communities in response to methane stimulus in laboratory microcosm incubations prepared with lake sediment samples. We first measured taxonomic compositions of long-term enrichment cultures and determined that, although dominated by Methylococcaceae types, these cultures also contained accompanying types belonging to a limited number of bacterial taxa, methylotrophs and non-methylotrophs. We then followed the short-term community dynamics, in two oxygen tension regimens (150 μM and 15 μM), observing rapid loss of species diversity. In all microcosms, a single type of Methylobacter represented the major methane-oxidizing partner. The accompanying members of the communities revealed different trajectories in response to different oxygen tensions, with Methylotenera species being the early responders to methane stimulus under both conditions. The communities in both conditions were convergent in terms of their assemblage, suggesting selection for specific taxa. Our results support prior observations from metagenomics on distribution of carbon from methane among diverse bacterial populations and further suggest that communities are likely responsible for methane cycling, rather than a single type of microbe.     

Co-cultivation of Thermoanaerobacter strains with a methanogenic partner enhances glycerol conversion

Glycerol-rich waste streams produced by the biodiesel, bioethanol and oleochemical industries can be treated and valorized by anaerobic microbial communities to produce methane. As current knowledge of the microorganisms involved in thermophilic glycerol conversion to methane is scarce, thermophilic glycerol-degrading methanogenic communities were enriched. A co-culture of Thermoanaerobacter and Methanothermobacter species was obtained, pointing to a non-obligately syntrophic glycerol degradation. This hypothesis was further studied by incubating Thermoanaerobacter brockii subsp. finnii and T. wiegelii with glycerol (10 mM) in pure culture and with different hydrogenotrophic methanogens. The presence of the methanogen accelerated glycerol fermentation by the two Thermoanaerobacter strains up to 3.3 mM day⁻¹, corresponding to 12 times higher volumetric glycerol depletion rates in the methanogenic co-cultures than in the pure bacterial cultures. The catabolic pathways of glycerol conversion were identified by genome analysis of the two Thermoanaerobacter strains. NADH and reduced ferredoxin formed in the pathway are linked to proton reduction, which becomes thermodynamically favourable when the hydrogen partial pressure is kept low by the hydrogenotrophic methanogenic partner.     

Novel exon nucleotide deletion causes adrenoleukodystrophy in a Brazilian family

Adrenoleukodystrophy is a neurodegenerative X-linked recessive disorder. It is characterized by abnormal function of peroxisomes, which leads to an accumulation of very long-chain fatty acids in plasma and tissues, especially in the cortex of adrenal glands and white matter of the central nervous system, causing demyelinating disease and adrenocortical insufficiency (Addison's disease). It is caused by a mutation in the ABCD1 gene (ATP-binding cassette, subfamily D, member 1), which encodes the protein adrenoleukodystrophy that is involved in the transport of fatty acids into the peroxisome for degradation. Variable expression has been recognized in families of patients who have this disease. A Brazilian family from Minas Gerais State, Brazil, was studied. The proband is an adult living in Minas Gerais State, Brazil; he had adrenomyeloneuropathy, adrenocortical insufficiency and a stable cerebral form. DNA was extracted from a blood sample and was sequenced to identify the mutation. The patient's exons were cloned for confirmation. A new mutation was found in exon 5 of the ABCD1 gene (c.1430delA), as well as a single-nucleotide polymorphism in exon 6. The mutation causes a frame shift, resulting in a truncated protein with almost total absence of the ATP binding domain.     

Comparative analysis of gonadal morphology in six fish species of the Incertae Sedis genera in Characidae of occurrence in the São Francisco River Basin,Brazil

Martins, Y.S., Arantes, F.P., Sato, Y., dos Santos, J.E., Rizzo, E. and Bazzoli, N. 2012. Comparative analysis of gonadal morphology in six fish species of the Incertae Sedis genera in Characidae of occurrence in the São Francisco River Basin, Brazil. —Acta Zoologica (Stockholm) 93 : 48–56. This study presents a comparative analysis aiming to show the remarkable differences found in gonad morphology between six fish species from the genera Incertae Sedis in the Characidae family. Maturing ovaries of Astyanax fasciatus presented grayish color whilst the other species’ were yellowish in color. The cortical alveoli of the analyzed species are small (5.20 ± 1.44–8.28 ± 2.02 μm) and are formed by various discontinuous layers of vesicles except in the Bryconops affinis, where they are large (12.87 ± 2.41 μm) and form various continuous layers of vesicles. The pellucid zone is thin and varies from 2.44 ± 0.90 to 5.79 ± 1.90 μm and is thickest in B. affinis (10.57 ± 2.08 μm). Folds in the pellucid zone were observed in Astyanax bimaculatus, A. fasciatus, Hemigrammus marginatus, and Moenkhausia costae. The follicular cells of B. affinis are columnar (28.19 ± 13.71 μm), while they are squamous in other species (1.52 ± 0.64–2.12 ± 0.78 μm). This study showed that the morphologic and biometric characteristics of the B. affinis vitellogenic oocytes are statistically different than the analyzed other ones Incertae Sedis of the Characidae family. In advanced maturing testis of A. bimaculatus and A. fasciatus, the spermatozoa were embedded in acidophilic secretion which was gradually reabsorbed in the seminiferous tubules when males were partially spent.     

The adsorption and enzyme activity profiles of specific Trichoderma reesei cellulase/xylanase components when hydrolyzing steam pretreated corn stover

Recycling of enzymes during biomass conversion is one potential strategy to reduce the cost of the hydrolysis step of cellulosic ethanol production. Devising an efficient enzyme recycling strategy requires a good understanding of how the enzymes adsorb, distribute, and interact with the substrate during hydrolysis. We investigated the interaction of individual Trichoderma reesei enzymes present in a commercial cellulase mixture during the hydrolysis of steam-pretreated corn stover (SPCS). The enzyme profiles were followed using zymograms, gel electrophoresis, enzyme activity assays and mass spectrometry. The adsorption and activity profiles of 6 specific enzymes Cel7A (CBH I), Cel7B (EG I), Cel5A (EG II), Xyn 10 (endo-1,4-β-xylanase III), Xyn 11 (endo-xylanase II), and β-glucosidase were characterized. Initially, each of the enzymes rapidly adsorbed onto the SPCS. However, this was followed by partial desorption to an adsorption equilibrium where the Cel7A, Cel7B, Xyn 10, and β-glucosidase were partially adsorbed to the SPCS and also found free in solution throughout the course of hydrolysis. In contrast, the Cel5A and Xyn 11 components remained primarily free in the supernatant. The Cel7A component also exhibited a partial desorption when the rate of hydrolysis leveled off as evidenced by MUC zymogram and SDS-PAGE. Those cellulase components that did not bind to the substrate were generally less stable and lost their activities within the first 24h when compared to enzymes that were distributed in both the liquid and solid phases. Therefore, to ensure maximum enzyme activity recovery, enzyme recycling seems to be most effective when short-term rounds of hydrolysis are combined with the recovery of enzymes from both the liquid and the solid phases and potentially enzyme supplementation to replenish lost activity.     

Moving instead of asking? Performance-based tests and BASFI-questionnaire measure different aspects of physical function in ankylosing spondylitis

Introduction

Ankylosing Spondylitis (AS) is characterised by limitations in physical function. The Bath Ankylosing Spondylitis Functional Index (BASFI) is considered to be the gold-standard to assess physical function in AS patients. However, the BASFI questionnaire is a self-reported outcome measure and susceptible to subjective interpretation (under- or over-estimation). More objective outcome measures, like performance-based tests, could provide an objective outcome measurement for the evaluation of limitations in physical function. Therefore, the primary aim of this study was to determine the association between performance-based measures and the BASFI questionnaire.

Methods

In this cross-sectional study 126 AS patients completed the BASFI questionnaire and eight performance-based tests based on BASFI-items. Each test received three scores: one for performance (time or points) and a score for exertion and pain experienced during performance (using modified Borg-scale and VAS 0-100 mm, respectively). Linear regression analyses were used to assess the associations between the BASFI questionnaire and performance-based tests.

Results

The univariable association between performance and BASFI-score was moderate with a R-square of 0.31 and Beta of 0.56 (p's < 0.05). In a multivariable analysis, the association between performance, exertion and pain on the one hand and BASFI-score on the other was assessed; R-square increased to 0.54: the Beta's for exertion and pain during performance were 0.38 and 0.26, respectively; the Beta for performance decreased to 0.19 (p's < 0.05).

Conclusions

This study demonstrates that alongside actual performance, patients seem to incorporate exertion and pain in their assessment of perceived physical function on the BASFI questionnaire. Performance-based tests could provide an objective outcome measurement for the evaluation of physical function and give relevant new information in addition to the BASFI questionnaire.     

Environmental Mapping of Paracoccidioides spp. in Brazil Reveals New Clues into Genetic Diversity,Biogeography and Wild Host Association

BackgroundParacoccidioides brasiliensis and Paracoccidioides lutzii are the etiological agents of Paracoccidioidomycosis (PCM), and are easily isolated from human patients. However, due to human migration and a long latency period, clinical isolates do not reflect the spatial distribution of these pathogens. Molecular detection of P. brasiliensis and P. lutzii from soil, as well as their isolation from wild animals such as armadillos, are important for monitoring their environmental and geographical distribution. This study aimed to detect and, for the first time, evaluate the genetic diversity of P. brasiliensis and P. lutzii for Paracoccidioidomycosis in endemic and non-endemic areas of the environment, by using Nested PCR and in situ hybridization techniques.Conclusions/SignificanceData may reflect the actual occurrence of Paracoccidioides species in their saprobic habitat, despite their absence/non-detection in seven armadillos evaluated in regions with high prevalence of PCM infection by P. lutzii. These results may indicate a possible ecological difference between P. brasiliensis and P. lutzii concerning their wild hosts.     

Scorpion venom increases mRNA expression of lung cytokines

Previous studies have demonstrated that scorpion toxins increase the serum levels of IL-1, IL-6, INF-gamma, and GM-CSF in patients with severe shock and pulmonary edema. Moreover, it has been shown that experimental models of scorpion envenomation presented an increase in serum levels of IL-1, IL-6, IFN-gamma and nitric oxide. Thus, it is possible that the cytokine release may contribute to the onset and maintenance of the pulmonary edema induced by scorpion venom. This study was designed to investigate whether inflammatory and non-inflammatory cytokines, contribute to the pulmonary injury induced by infusion of Tityus serrulatus scorpion toxin in rats. We show that scorpion venom not only increases the expression of mRNA pulmonary inflammatory cytokines but also non-inflammatory cytokines as well. Moreover, the expression of IL-1alpha, IL-1beta and IL-6 mRNA was shown to be higher among the remaining detectable cytokines. The findings of this study provide additional insight towards the understanding of the pathophysiology of the pulmonary edema induced by scorpion venom. The increased level of pulmonary cytokines observed during the pulmonary edema may be responsible for the exacerbation and maintenance of the inflammatory response to scorpion venom in the lungs.