Ecological host fitting of Trypanosoma cruzi TcI in Bolivia: mosaic population structure, hybridization and a role for humans in Andean parasite dispersal.

An improved understanding of how a parasite species exploits its genetic repertoire to colonize novel hosts and environmental niches is crucial to establish the epidemiological risk associated with emergent pathogenic genotypes. Trypanosoma cruzi, a genetically heterogeneous, multi-host zoonosis, provides an ideal system to examine the sylvatic diversification of parasitic protozoa. In Bolivia, T. cruzi I, the oldest and most widespread genetic lineage, is pervasive across a range of ecological clines. High-resolution nuclear (26 loci) and mitochondrial (10 loci) genotyping of 199 contemporaneous sylvatic TcI clones was undertaken to provide insights into the biogeographical basis of T. cruzi evolution. Three distinct sylvatic parasite transmission cycles were identified: one highland population among terrestrial rodent and triatomine species, composed of genetically homogenous strains (Ar = 2.95; PA/L = 0.61; DAS = 0.151), and two highly diverse, parasite assemblages circulating among predominantly arboreal mammals and vectors in the lowlands (Ar = 3.40 and 3.93; PA/L = 1.12 and 0.60; DAS = 0.425 and 0.311, respectively). Very limited gene flow between neighbouring terrestrial highland and arboreal lowland areas (distance ~220 km; FST = 0.42 and 0.35) but strong connectivity between ecologically similar but geographically disparate terrestrial highland ecotopes (distance >465 km; FST = 0.016-0.084) strongly supports ecological host fitting as the predominant mechanism of parasite diversification. Dissimilar heterozygosity estimates (excess in highlands, deficit in lowlands) and mitochondrial introgression among lowland strains may indicate fundamental differences in mating strategies between populations. Finally, accelerated parasite dissemination between densely populated, highland areas, compared to uninhabited lowland foci, likely reflects passive, long-range anthroponotic dispersal. The impact of humans on the risk of epizootic Chagas disease transmission in Bolivia is discussed

Eficiência do processo de biodigestão em fossa séptica biodigestora inoculada com esterco de ovino.

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Designing a shipboard line transect survey to estimate cetacean abundance off the Azores archipelago

Management schemes dedicated to the conservation of wildlife populations rely on the effective monitoring of population size, and this may require the accurate and precise estimation of this parameter. Line transect distance sampling can be an effective approach for estimating abundance. Little information is available regarding cetacean abundance in the Azores. This paper had two aims: 1) to design a line transect shipboard survey to estimate the absolute abundance of the most common cetaceans off the Azores; and 2) to provide a set of potential survey effort scenarios to policy makers and environmental managers. Three survey scenarios are assessed, and one detailed survey design is presented. A total of 8,800 km of survey effort is recommended; at this level the expected coefficient of variation of estimates is less than 0.3 for most species. However, if logistic constraints prevent this, at least 5,000 km of survey effort should be used to achieve minimum sample size requirements; this is estimated to take 36 days of effort. It is also recommended to conduct a pilot survey. This would provide more detailed information that could be used to improve the survey design of what would be the first survey of this magnitude ever to be implemented in the Azores

Trypanosoma cruzi IIc: phylogenetic and phylogeographic insights from sequence and microsatellite analysis and potential impact on emergent Chagas disease.

Trypanosoma cruzi, the etiological agent of Chagas disease, is highly genetically diverse. Numerous lines of evidence point to the existence of six stable genetic lineages or DTUs: TcI, TcIIa, TcIIb, TcIIc, TcIId, and TcIIe. Molecular dating suggests that T. cruzi is likely to have been an endemic infection of neotropical mammalian fauna for many millions of years. Here we have applied a panel of 49 polymorphic microsatellite markers developed from the online T. cruzi genome to document genetic diversity among 53 isolates belonging to TcIIc, a lineage so far recorded almost exclusively in silvatic transmission cycles but increasingly a potential source of human infection. These data are complemented by parallel analysis of sequence variation in a fragment of the glucose-6-phosphate isomerase gene. New isolates confirm that TcIIc is associated with terrestrial transmission cycles and armadillo reservoir hosts, and demonstrate that TcIIc is far more widespread than previously thought, with a distribution at least from Western Venezuela to the Argentine Chaco. We show that TcIIc is truly a discrete T. cruzi lineage, that it could have an ancient origin and that diversity occurs within the terrestrial niche independently of the host species. We also show that spatial structure among TcIIc isolates from its principal host, the armadillo Dasypus novemcinctus, is greater than that among TcI from Didelphis spp. opossums and link this observation to differences in ecology of their respective niches. Homozygosity in TcIIc populations and some linkage indices indicate the possibility of recombination but cannot yet be effectively discriminated from a high genome-wide frequency of gene conversion. Finally, we suggest that the derived TcIIc population genetic data have a vital role in determining the origin of the epidemiologically important hybrid lineages TcIId and TcIIe

A NEW ENHANCED GOAT ALGORITHM FOR FINDING OPTIMUM SWITCHING ANGLE AND HARMONIC REDUCTION

Abstract:-Multi level inverters are used now a days at large,because they have lesser harmonics  than single level inverter. Several methodologies  have been worked out  in order  to reduce the harmonics.It has been proved that  the soft computing algorithms based switching angle calculation are more efficient than the conventional methods.In this paper  a 7 level inverter has been used  for DC to AC conversion.A new nature inspired Goat algorithm has been proposed  in this paper.This algorithm has been applied  for  a single phase  seven level inverter first. This algorithm has been tested by writing proper code  in MATLAB-Mfile and it has been found that it consumes  less computational time than the other  algorithms since several goats explore solution space at a time. The results show  that the  harmonics obtained from inverter using the switching angles calculated from the algorithm are very much reduced and THD  is almost around 12%.Key Words-7 level inverter, Goat algorithm, Switching angle ,Total harmonic distortio

Cartilage and bone regeneration: how close are we to bedside?

The treatment/regeneration of bone and cartilage diseases or defects, whether induced by rheumatism, joint dysplasia, trauma, or surgery presents great challenges that have not been fully solved by the current therapies. In the last few years, tissue engineering and regenerative medicine have been proposing advanced tools and technologies for bone and cartilage tissue regeneration, and some of which have successfully reached the market. Beyond the source of cells, the creation of superior structures for replacing defective bone and cartilage requires strong research in biomechanical signaling and synthesis of advanced biomaterials to mimic human tissues at the most varied levels. Natural and synthetic polymers, bioresorbable inorganic materials, and composites have been investigated for its potential as scaffolding materials with enhanced mechanical and biological properties. Porous scaffolds, hydrogels, and fibers are the most commonly biomimetic structures used for bone and cartilage tissue engineering. Herein, the concepts and current treatment strategies for bone and cartilage repair, as well as biomimetic strategies for bone and cartilage tissue engineering are overviewed. A global review of the ongoing clinical trials and of the scaffolds commercially available for the repair of osteochondral tissue is also presented.(undefined

Can cardiac computed tomography predict cardiovascular events in asymptomatic type-2 diabetics?: results of a long term follow-up

BACKGROUND: Doubts remain about atherosclerotic disease and risk stratification of asymptomatic type-2 diabetic patients (T2DP). This study aims to evaluate the usefulness of calcium score (CS) and coronary computed tomography (CT) angiography (CTA) to predict fatal and non fatal cardiovascular events (CVEV) in T2DP. METHODS: Eighty-five consecutive T2DP undergoing CT (Phillips Brilliance, 16-slice) with CS and CTA were prospectively enrolled in a transversal case-control study. Patients were followed for 48 months (range 18 - 68) to assess CVEV: cardiovascular death, acute coronary syndrome, revascularisation and stroke. Potential predictors of CVEV were identified. Predictive models based on clinical features, CTA and CS were created and compared. RESULTS: Performing CT impacted T2DP treatment. Cardiovascular risk was lowered during follow-up but metabolic control remained suboptimal. CVEV occurred in 11.8% T2DP (3.1%/year). CS ≥86.6 was predictor of CVEV over time, with a high negative predictive value, an 80% sensitivity and 74.7% specificity. Although its prognostic value was not independent of the presence/absence of obstructive CAD, adding CS and CTA data to clinical parameters improved the prediction of CVEV: the combined model had the highest AUC (0.888, 95%CI 0.789-0.987, p < 0.001) for the prediction of the study endpoints. CONCLUSIONS: CS showed great value in T2DP risk stratification and its prognostic value was further enhanced by CTA data. Information provided by CT may help predict CVEV in T2DP and potentially improve their outcome