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The study aims to evaluate the antiprotozoal activities of 20 plant metabolites on Trypanosoma cruzi and Leishmania amazonensis amastigotes. Compounds 1–20 were obtained and identified by using chromatographic and spectroscopic techniques. The antiparasitic assays were performed on the intracellular form of T. cruzi and L. amazonensis using human leukaemic THP-1 cells as the host. The mechanism of action of the most active compounds was explored in silico by molecular docking using T. cruzi trypanothione reductase (TR) as a target, whereas the in vitro studies were performed by enzymatic assay using T. cruzi recombinant TR. In addition, the mitochondrial membrane potential was evaluated by flow cytometry. Two flavonoids, one triterpene and three acetogenins showed from high to moderate trypanocidal activities with IC50 values ranging 3.6–37.2 µm while three of the metabolites were moderately leishmanicidal. The molecular docking study revealed interactions between TR and the most trypanocidal compounds 1 (abyssinone IV) and 2 (atalantoflavone). In contrast, both showed no effect on TR in vitro. For the mitochondrial membrane potential assay, atalantoflavone (2) displayed a dose-dependent depolarization. On the basis of the aforementioned results, this compound's structure could be chemically explored in order to develop more potent trypanocidal derivatives.
To compare the epidemiology, clinical characteristics, and mortality of patients with bloodstream infections (BSI) caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) versus ESBL-producing Klebsiella pneumoniae (ESBL-KP) and to examine the differences in clinical characteristics and outcome between BSIs caused by isolates with CTX-M versus other ESBL genotypes
As part of the INCREMENT project, 33 tertiary hospitals in 12 countries retrospectively collected data on adult patients diagnosed with ESBL-EC BSI or ESBL-KP BSI between 2004 and 2013. Risk factors for ESBL-EC versus ESBL-KP BSI and for 30-day mortality were examined by bivariate analysis followed by multivariable logistic regression.
The study included 909 patients: 687 with ESBL-EC BSI and 222 with ESBL-KP BSI. ESBL genotype by polymerase chain reaction amplification of 286 isolates was available. ESBL-KP BSI was associated with intensive care unit admission, cardiovascular and neurological comorbidities, length of stay to bacteremia >14 days from admission, and a nonurinary source. Overall, 30-day mortality was significantly higher in patients with ESBL-KP BSI than ESBL-EC BSI (33.7% vs 17.4%; odds ratio, 1.64; P=.016). CTX-M was the most prevalent ESBL subtype identified (218 of 286 polymerase chain reaction-tested isolates, 76%). No differences in clinical characteristics or in mortality between CTX-M and non–CTX-M ESBLs were detected.
Clinical characteristics and risk of mortality differ significantly between ESBL-EC and ESBL-KP BSI. Therefore, all ESBL-producing Enterobacteriaceae should not be considered a homogeneous group. No differences in outcomes between genotypes were detected.
Leishmaniasis are diseases caused by parasites of the genus Leishmania and transmitted to humans by the bite of infected insects of the subfamily Phlebotominae. Current drug therapy shows high toxicity and severe adverse effects. Recently, two oligopeptidases (OPBs) were identified in Leishmania amazonensis, namely oligopeptidase B (OPB) and oligopeptidase B2 (OPB2). These OPBs could be ideal targets, since both enzymes are expressed in all parasite lifecycle and were not identified in human. This work aimed to identify possible dual inhibitors of OPB and OPB2 from L. amazonensis. The three-dimensional structures of both enzymes were built by comparative modelling and used to perform a virtual screening of ZINC database by DOCK Blaster server. It is the first time that OPB models from L. amazonensis are used to virtual screening approach. Four hundred compounds were identified as possible inhibitors to each enzyme. The top scored compounds were submitted to refinement by AutoDock program. The best results suggest that compounds interact with important residues, as Tyr490, Glu612 and Arg655 (OPB numbers). The identified compounds showed better results than antipain and drugs currently used against leishmaniasis when ADMET in silico were performed. These compounds could be explored in order to find dual inhibitors of OPB and OPB2 from L. amazonensis.
The experiment, conducted at Bahia, Brazil, from May to August 2010, aimed to evaluate the nitrogen (N) balance, urea excretion and microbial protein synthesis in lactating goats fed pelleted concentrates with the addition of crude protein (CP), obtained by replacing alfalfa hay with soybean meal. The diets consisted of different levels of CP and 200 g of roughage (Tifton 85 hay)/kg. Maize and mesquite bran were used as the energy source, with maize replaced by mesquite bran in the ratio of 1·7:1. Eight female Saanen goats were used, confined in individual pens and allocated to a 4 × 4 Latin square design. The N balance in the body was positive, and loss of body weight (–0·03 g/day) was observed for the diet with 190 g CP/kg. The concentration (mg/dl) of urea in urine, milk and blood plasma was positively influenced in a linear form, and the highest rate of increase was found in urine, with 2 mg/dl for every 10 g CP/kg added to the diet. The microbial protein synthesis was not affected, but the diets reduced the microbial protein (44 g/day) and its ruminal production efficiency (30 g/kg total digestible nutrients). The levels above 190 g of CP are not recommended because of the energy expenditure required to excrete the urea.
We present the dynamical and stellar population analysis of 12 dwarf elliptical galaxies (dEs) observed using the SAURON IFU (WHT, La Palma). We demonstrate that dEs have lower angular momenta than their presumed late-type progenitors and we show that dE circular velocity curves are steeper than the rotation curves of galaxies with equal and up to an order of magnitude higher luminosity. Transformation due to tidal harassment is able to explain all of the above, unless the dE progenitors were already compact and had lower angular momenta at higher redshifts. We then look at the star formation histories (SFHs) of our galaxies and find that for the majority of them star formation activity was either still strong at a few Gyr of age or they experienced a secondary burst of star formation roughly at that time. This latter possibility would be in agreement with the scenario where tidal harassment drives the remaining gas inwards and induces a secondary star formation episode. Finally, one of our galaxies appears to be composed exclusively of an old population (≳12 Gyr). Combining this with our earlier dynamical results, we conclude that it either was ram-pressure stripped early on in its evolution in a group environment and subsequently tidally heated (which lowered its angular momentum and increased compactness), or that it evolved in situ in the cluster's central parts, compact enough to avoid tidal disruption.
To evaluate the association between weight gain in the first two years of life and the occurrence of wheezing, asthma, serum IgE, skin reactivity and pulmonary function.
The metropolitan region of Salvador, Bahia, Brazil.
The association was studied between 1997 and 2005 in 669 children up to 11 years of age. Data were collected on asthma and risk factors, both current factors and those present in the first years of life. Weight gain was considered fast when the Z-score was >0·67. Poisson regression was used in the multivariate statistical analysis.
Wheezing was reported in 25·6 % of the children. Weight gain was considered fast (Z-score >0·67) in 29·6 % of the children and slow (Z-score <−0·67) in 13·9 %. Children in the slow weight gain group had 36 % fewer symptoms of asthma (prevalence ratio = 0·65; 95 % CI 0·42, 0·99).
Slower weight gain in the early years of life may constitute a protective factor against symptoms of asthma. The relevance of this finding for public health is not yet certain, since it is known that children with slow and fast weight gain may be more likely to develop adverse health consequences related to both these situations.
To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4–12 years of age living in the city of Salvador in 2005.
Cross-sectional study nested in a cohort.
The metropolitan region of Salvador, Bahia, Brazil.
The study included 1129 children of 4–12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. Poisson's multivariate regression was adopted.
Wheezing was found in 29·1% and asthma in 22·8% of children, both conditions being more common in those under 6 years of age and 34% more common in overweight children (prevalence ratio (PR) = 1·34; 95% CI 1·07, 1·67) following adjustment. The ratio between forced expiratory volume in 1s and forced vital capacity was associated with overweight (PR = 1·35; 95% CI 1·11, 1·61). No statistically significant association was found between overweight and allergen-specific IgE or with wheezing.
These results are in agreement with the hypothesis that overweight is associated with asthma and pulmonary function, even following adjustment for intervening variables known to be associated with the pathogeny of asthma.
The Tarantula Survey is an ESO Large Programme which has obtained multi-epoch spectroscopy of over 1,000 massive stars in the 30 Doradus region of the Large Magellanic Cloud. The assembled consortium will exploit these data to address a range of fundamental questions in both stellar and cluster evolution.
The spatial distribution of Farfantepenaeus shrimp was analysed in the Laguna Madre of Tamaulipas, Mexico. Sampling was carried out on submerged aquatic vegetation (SAV) habitats at five sites located along the coastal lagoon. Two nocturnal surveys were conducted during winter in 2005 (January–February), collecting a total of 3268 shrimp individuals. SAV beds were composed of a mixture of drift algae (mainly Digenia simplex), attached algae (mainly Penicillus capitatus and Udotea occidentalis) and seagrass (mainly Halodule wrightii). Farfantepenaeus aztecus was more abundant (39.5%) than F. duorarum (36.8%), and the remaining 23.7% corresponding to small unidentified Farfantepenaeus spp. were classified as recruits. Abundance of F. aztecus was significantly higher at sites 2 and 4, whereas F. duorarum did not show significant distribution differences along the Laguna Madre. Recruits, juveniles and total shrimp tended to decrease significantly at the northern part of the lagoon (site 1), where substrate was dominated by drifting algae and seagrasses were scarce or absent. The abundance of shrimp was positively related to seagrass biomass and/or water temperature, whereas there was a negligible or negative relationship with algal biomass. With the exception of subadults, a significant positive linear relationship between seagrass and shrimp abundance was fitted, indicating an increase in number of individuals of both species with increasing seagrass biomass. This suggests that seagrass is the most important component of SAV beds influencing the abundance of F. aztecus and F. duorarum along this hypersaline coastal lagoon.
EURECA (European Underground Rare Event Calorimeter Array) is an
astro-particle physics facility aiming to directly detect galactic dark
matter. The Laboratoire Souterrain de Modane has been selected as host
laboratory. The EURECA collaboration unites CRESST, EDELWEISS and the
Spanish-French experiment ROSEBUD, thus concentrating and focussing effort
on cryogenic detector research in Europe into a single facility. EURECA will
use a target mass of up to one ton, enough to explore WIMP – nucleon scalar
scattering cross sections in the region of 10-9 – 10-10 picobarn.
A major advantage of EURECA is the planned use of more than just one target
material (multi target experiment for WIMP identification).
Dupont's lark Chersophilus duponti was categorized globally as Near Threatened on the IUCN Red List in 2005, largely because of reported declines in Spain and an estimated population of 2,000–3,000 breeding pairs in Morocco. However, the range and size of the species' North African populations were still unknown, despite being critical for assessment of the species' global conservation status. Here we report on the breeding distribution of Dupont's lark in Morocco, probably the largest population in its North African range, as well as on its preferred habitat, population density and size. Fieldwork and analysis of satellite images were combined to locate suitable habitat for the species, assess its presence (eliciting territorial calls by broadcasting the males’ songs and calls), and estimate densities using 83 km of linear censuses. Total number of birds located was 461 (305 from song playback and 156 from transects) across an extent of occurrence of c. 11,000 km2, comprising 2,067 km2 of suitable habitat and an effective area of occupancy of 1,645 km2. Mean density was 0.60 ± SD 0.52 birds per 10 ha and was highest in dense stands of Stipa tennacissima. Our estimate of Dupont's lark breeding population in Morocco is c. 15,400 singing males (lower and upper limits 11,220–20,167, respectively). Evidence of habitat loss and degradation was found in one of the main areas of the species' distribution in Morocco, although this does not seem to be a general pattern in the lark's Moroccan range. Further studies are required of the dynamics of suitable habitat for the species to prevent long-term consequences for the conservation of Dupont's lark and other bird species of the steppe.
We discuss some recent integral field spectroscopy using the SAURON instrument of a sample consisting of 24 early-type spirals, part of the SAURON Survey, and 18 late-type spirals. Using 2-dimensional maps of their stellar radial velocity, velocity dispersion, and absorption line strength, it is now much easier to understand the nature of nearby galactic bulges. We discuss a few highlights of this work, and point out some new ideas about the formation of galactic bulges.
Supermassive black holes are a key element in our understanding of how galaxies form. Most of the progress in this very active field of research is based on just ~30 determination of black hole masses, accumulated over the past decade. We illustrate how integral-field spectroscopy, and in particular our OASIS modeling effort can help improve the current situation.
Using the unique dataset obtained within the course of the SAURON project, a radically new view of the structure, dynamics and stellar populations of early-type galaxies has emerged. We show that galaxies come in two broad flavours (slow and fast rotators), depending on whether or not they exhibit clear large-scale rotation, as indicated via a robust measure of the specific angular momentum of baryons. This property is also linked with other physical characteristics of early-type galaxies, such as: the presence of dynamically decoupled cores, orbital structure and anisotropy, stellar populations and dark matter content. I here report on the observed link between this baryonic angular momentum and a mass sequence, and how this uniquely relates to the building of the red sequence via dissipative/dissipationless mergers and secular evolution.
We discuss SAURON absorption line strength maps of a sample of 24 early-type spirals, mostly Sa. From the Lick indices Hβ, Mgb and Fe 5015 we derive SSP-ages and metallicities. By comparing the scaling relations of Mg b and Hβ and central velocity dispersion with the same relation for the edge-on sample of Falcón-Barroso et al. (2002) we derive a picture in which the central regions of Sa galaxies contain at least 2 components: one (or more) thin, disc-like component, often containing recent star formation, and another, elliptical-like component, consisting of old stars and rotating more slowly, dominating the light above the plane. If one defines a bulge to be the component responsible for the light in excess of the outer exponential disc, then many Sa-bulges are dominated by a thin, disc-like component containing recent star formation.
We summarize results from McDermid et al. (2006), who present a set of follow-up observations of the sauron representative survey of early-type galaxies. We used the oasis integral-field spectrograph (while at the Canada-France-Hawaii Telescope) to obtain high spatial resolution spectra of 28 elliptical and lenticular galaxies. These seeing-limited data have on average twice the spatial resolution of the sauron data, albeit over a smaller field. These new data reveal previously unresolved features in these objects' stellar kinematics, stellar populations, and ionized gas properties. In this contribution, we focus on the discovery of a population of compact kinematically decoupled cores in a number of our sample galaxies. These compact cores are related to regions of young stars, and counter-rotate around the host galaxy's minor axis. We compare these objects to previously known decoupled components, which in contrast are composed of old stars, and which rotate around axes unrelated to the host galaxy's kinematics or shape. A key difference between these two kinds of decoupled cores are their physical size and relative mass. The compact decoupled cores are smaller than a few hundred parsec, and constitute less than a few percent of the total galaxy mass. The ‘classical’ decoupled cores exist on kiloparsec scales, and comprise around a factor 10 more mass. We suggest that the small components are only found with young ages because of their low mass-to-light ratio. We show that after a few Gyrs, these components ‘fade’ into the background galaxy, making them more difficult to detect. We draw the following conclusions: 1) young stars found in early-type galaxies are very often associated with centrally-concentrated counter-rotating components; 2) the small mass fraction and kinematic decoupling of these cores suggests that the star formation is associated to minor accretion events, which effectively drive the spread in luminosity-weighted ages found in early-type galaxies; and 3) such decoupled components may be common in all early-type galaxies, but not directly observed due to their small contribution to the total galaxy light at older ages.
In this poster contribution, we present results from high spatial resolution integral-field spectroscopy of elliptical (E) and lenticular (S0) galaxies from the SAURON representative survey, obtained with the OASIS and GMOS spectrographs. These seeing-limited observations explore the central ∼10''10″ (typically one kiloparsec diameter) regions of these galaxies using a spatial sampling four times higher than SAURON (0″27 vs. 0″94 spatial elements), resulting in almost a factor of two improvement in the median PSF. These data allow accurate study of the central regions to complement the large-scale view provided by SAURON. We derive the stellar and gas kinematics, stellar absorption-line strengths and nebular emission-line strengths for our sample, and derive maps of the luminosity-weighted stellar age, metallicity and abundance ratio via stellar population models. From these data we find a wealth of structures either not seen or poorly resolved in the SAURON data, including a number of kinematically-decoupled cores (KDCs) in the centres of some galaxies. We compare the intrinsic size and luminosity-weighted stellar age of all the visible KDCs in the full SAURON sample, and find two types of components: kiloparsec-scale KDCs, which are older than 8 Gyr, and are found in galaxies with little net rotation; and compact KDCs, which have intrinsic diameters of less than a few hundred parsec, show a range of stellar ages from 0.5 - 15 Gyr (with 5/6 younger than 5 Gyr), are found exclusively in fast-rotating galaxies, and are close to counter-rotating around the same axis as their host. Of the 7 galaxies in the SAURON sample with integrated luminosity-weighted ages less than 5 Gyr, 5 show such compact KDCs, suggesting a link between counter-rotation and recent star-formation. We show that this may be partly due to a combination of small sample size at young ages, and an observational bias, since young KDCs are easier to detect than their older and/or co-rot ating counterparts.
Proteolytic activities of 5 strains of Leishmania (Viannia) braziliensis isolated from Brazilian and Colombian patients, presenting distinct clinical manifestations, were characterized and compared using whole-promastigote extracts and extracellular secretions. Zymographic assays concerning whole-cell extracts and supernatants resulted in the detection of high molecular weight bands, ranging from 50 to 125 kDa. Proteolytic activities from both whole-cell extracts and supernatants were optimal in a pH range 5·5 to 9·0 for all analysed strains. Such protease activities were inhibited when 10 mM 1,10-phenanthroline was assayed, strongly suggesting that the enzymes responsible for hydrolysis of the substrate belong to the metalloproteases class. Distinct profiles of metalloproteases were observed among the studied L. (V.) braziliensis strains. Differences among the microorganisms might be related to the geographical origin of the strains and/or to the clinical presentation.