626 research outputs found

    Generalized Convolution Roots of Positive Definite Kernels on Complex Spheres

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    Convolution is an important tool in the construction of positive definite kernels on a manifold. This contribution provides conditions on an L2L^2-positive definite and zonal kernel on the unit sphere of Cq\mathbb{C}^q in order that the kernel can be recovered as a generalized convolution root of an equally positive definite and zonal kernel

    Estimate of body growth curve and feed intake of free-range chickens receiving different levels of digestible lysine

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    Aim of the study: To adjust nonlinear Gompertz model to describe the body growth and feed intake (FI) of free-range chickens of the CPK (Color Plumé) strain, receiving different levels of digestible lysine (dig-Lys), from 21 to 77 days of age.Area of study: São Cristovão, Sergipe, Brazil.Material and methods: A total of 432 one-day-old unsexed chickens were used in the study. At 21 days of age, the birds were assigned to four treatments (0.85%; 0.97%; 1.09%; 1.21%) of dig-Lys, in a completely randomized design with four replicates, with 27 birds per experimental unit. The Gompertz model was used to estimate bird growth curves related to body weight (BW) and FI at each Lys level.Main results: The tests of comparison between the parameters of the Gompertz model for each Lys level showed that parameter A varied, while parameters B (0.0329) and C (45.819) did not differ significantly. In parameter A, the dig-Lys level of 0.97% provided the highest BW estimate at maturity and maximum BW at the inflection point.Research highlights: Use of non-linear models to predict nutritional requirements, helps farmers to optimize management decisions and, thus, maximize their profit. According to Gompertz model, it was possible to infer that the inclusion of 0.97% dig-Lys in the diet of mixed batches of free-range chickens of the CPK strain meets their nutritional requirements

    Regional differences of testicular artery blood flow in post pubertal and pre-pubertal dogs

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    Background Measurement of testicular artery blood flow is used in several species to evaluate reproductive function and testicular and scrotal pathology. In dogs there are inconsistent reports about normal flow in post-pubertal dogs and no information concerning pre-pubertal dogs. The aim of this study was to describe regional differences in testicular artery blood flow in clinically normal post-pubertal and pre-pubertal dogs with no history of reproductive tract disease. Results The post-pubertal dogs produced normal ejaculates throughout the study. In all dogs the three different regions of the artery were imaged and monophasic flow with an obvious systolic peak and flow throughout diastole was observed on every occasion. The highest peak systolic velocity (PSV) and end diastolic velocity (EDV) were measured within the distal supra-testicular artery and marginal artery whilst the lowest PSV and EDV were measured within the intra-testicular arteries. Flow measurements were not different between left and right testes and were consistent between dogs on different examination days. Calculated resistance index (RI) and pulsatility index (PI) were lowest in the intra-testicular arteries. The pre-pubertal dogs had significantly smaller testes than the post-pubertal dogs (p < 0.05) and were unable to ejaculate during the study. The three different artery regions were imaged at every examination time point, and flow profiles had a similar appearance to those of the post-pubertal dogs. PSV, EDV, RI and PI showed a similar trend to the post-pubertal dogs in that values were lowest in the intra-testicular arteries. Notably, values of PSV, EDV, RI and PI were significantly lower (p < 0.05) in pre-pubertal dogs compared with post-pubertal dogs. Conclusions This study demonstrated important regional and pubertal differences in testicular artery blood flow of dogs, and form the basis for establishing baseline reference values that may be employed for the purposes of clinical diagnosis

    The emergence of arboviruses changes the profile of viral meningitis in Salvador, Bahia: A case series

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    Background: Recently, different arboviruses became endemic in Brazil mostlycausing acute febrile illnesses, however, neurological manifestations have alsobeen reported. This study aimed to investigate which viruses were involved inthe meningitis etiology and the contribution of the circulating arboviruses inSalvador, Bahia, Brazil.Methods: From June 2014 to February 2016, 170 patients with suspected viralmeningitis were identified in Couto Maia Hospital, Salvador-BA, Brazil. TheirCSF samples were investigated for possible viral etiology by reversetranscription-PCR (RT-PCR) for different arboviruses: DENV, ZIKV and CHIKV;and for the EV; and by PCR for the HHV1-5 complex (HSV1-2, VZV, EBV andCMV). Also, ELISA was carried out in a subgroup of remaining samples fordetection of DENV IgM and NS1 antigen, CHIKV IgM and ZIKV IgM.Results: Thirty-seven patients were PCR or ELISA positive for at least one of thestudied viruses (overall positivity 21.8%). EV was the agent most frequentlydetected (10 cases; 27.0%), along with all four DENV serotypes (10 cases;27.0%); followed by CHIKV (6 cases; 16.2%), ZIKV (6 cases; 16.2%), and Varicellazoster virus (VZV) (1 case; 2.7%). Four cases (10.8%) presented viral co-infectiondetected: DENV1 + CHIKV, DENV1 + EV, DENV4 + ZIKV, and CHIKV + ZIKV.Arboviruses (DENV, CHIKV and ZIKV) accounted for the great majority of cases(26 cases; 70.3%) of all single and co-infections: DENV has been the mostfrequently detected arbovirus (13 cases; 35.1%). Among non-arboviralmeningitis,the most common etiology was the EV (11 cases; 29.7%).Conclusions: Arboviruses accounted for the majority of identified virusesamong patients with suspected viral meningitis. In areas where they areendemic it is crucial to increase viral surveillance and consider them in thedifferential diagnosis of meningitis.Fil: Dias, Tamiris T.. Fundación Oswaldo Cruz; BrasilFil: Tauro, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Macêdo, Lara E. N.. Fundación Oswaldo Cruz; BrasilFil: Brito, Liz O.. Fundación Oswaldo Cruz; BrasilFil: Ribeiro, Victor H. O.. Fundación Oswaldo Cruz; BrasilFil: Santos, Cleiton S.. Fundación Oswaldo Cruz; BrasilFil: Jacob-Nascimento, Leile C.. Fundación Oswaldo Cruz; BrasilFil: Vilas-Boas, Letícia S.. Fundación Oswaldo Cruz; BrasilFil: Amado, Caio. Fundación Oswaldo Cruz; BrasilFil: Barbosa, Paula S.. Fundación Oswaldo Cruz; BrasilFil: Reis, Joice N.. Fundación Oswaldo Cruz; BrasilFil: Soares Campos, Gubio. Fundación Oswaldo Cruz; BrasilFil: Ribeiro, Guilherme S.. Fundación Oswaldo Cruz; BrasilFil: Siqueira, Isadora C.. Fundación Oswaldo Cruz; BrasilFil: Silva, Luciano K.. Fundación Oswaldo Cruz; BrasilFil: Reis, Mitermayer G.. Fundación Oswaldo Cruz; Brasi

    Genotype-phenotype Correlations In Cyp1b1-associated Primary Congenital Glaucoma Patients Representing Two Large Cohorts From India And Brazil

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background Primary congenital glaucoma (PCG), occurs due to the developmental defects in the trabecular meshwork and anterior chamber angle in children. PCG exhibits genetic heterogeneity and the CYP1B1 gene has been widely implicated worldwide. Despite the diverse mutation spectra, the clinical implications of these mutations are yet unclear. The present study attempted to delineate the clinical profile of PCG in the background of CYP1B1 mutations from a large cohort of 901 subjects from India (n=601) and Brazil (n=300). Methods Genotype-phenotype correlations was undertaken on clinically well characterized PCG cases from India (n=301) and Brazil (n=150) to assess the contributions of CYP1B1 mutation on a set of demographic and clinical parameters. The demographic (gender, and history of consanguinity) and quantitative clinical (presenting intraocular pressure [IOP] and corneal diameter [CD]) parameters were considered as binary and continuous variables, respectively, for PCG patients in the background of the overall mutation spectra and also with respect to the prevalent mutations in India (R368H) and Brazil (4340delG). All these variables were fitted in a multivariate logistic regression model using the Akaike Information Criterion (AIC) to estimate the adjusted odds ratio (OR) using the R software (version 2.14.1). Results The overall mutation spectrum were similar across the Indian and Brazilian PCG cases, despite significantly higher number of homozygous mutations in the former (p=0.024) and compound heterozygous mutations in the later (p=0.012). A wide allelic heterogeneity was observed and only 6 mutations were infrequently shared between these two populations. The adjusted ORs for the binary (demographic) and continuous (clinical) variables did not indicate any susceptibility to the observed mutations (p>0.05). Conclusions The present study demonstrated a lack of genotype-phenotype correlation of the demographic and clinical traits to CYP1B1 mutations in PCG at presentation. However, the susceptibility of these mutations to the long-term progression of these traits are yet to be deciphered.105Department of Science and Technology, Government of India [DST/INT/BRAZIL/RPO-01/2008]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [EU475687/20094

    Physical activity prevents alterations in mitochondrial ultrastructure and glucometabolic parameters in a high-sugar diet model.

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    Endurance exercise is a remarkable intervention for the treatment of many diseases. Mitochondrial changes on skeletal muscle are likely important for many of the benefits provided by exercise. In this study, we aimed to evaluate the effects that a regular physical activity (swimming without workload) has on mitochondrial morphological alterations and glucometabolic parameters induced by a high-sugar diet (HSD). Weaned male Wistar rats fed with a standard diet or a HSD (68% carbohydrate) were subjected to 60 minutes of regular physical activity by swimming (without workload) for four- (20 sessions) or eight-week (40 sessions) periods. After training, animals were euthanized and the sera, adipose tissues, and skeletal muscles were collected for further analysis. The HSD increased body weight after an 8- week period; it also increased the fat pads and the adipose index, resulting in glucose intolerance and insulin resistance (IR). Transmission electron microscopy showed an increase in alterations of mitochondrial ultrastructure in the gastrocnemius muscle, as well as a decrease in superoxide dismutase (SOD) activity, and an increase in protein carbonylation. Regular physical activity partially reverted these alterations in rats fed a HSD, preventing mitochondrial morphological alterations and IR. Moreover, we observed a decrease in Pgc1? expression (qPCR analysis) in STD-EXE group and a less pronounced reduction in HSD-EXE group after an 8-week period. Thus, regular physical activity (swimming without workload) in rats fed a HSD can prevent mitochondrial dysfunction and IR, highlighting the crucial role for physical activity on metabolic homeostasis

    Impairment of the Plasmodium falciparum Erythrocytic Cycle Induced by Angiotensin Peptides

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    Plasmodium falciparum causes the most serious complications of malaria and is a public health problem worldwide with over 2 million deaths each year. The erythrocyte invasion mechanisms by Plasmodium sp. have been well described, however the physiological aspects involving host components in this process are still poorly understood. Here, we provide evidence for the role of renin-angiotensin system (RAS) components in reducing erythrocyte invasion by P. falciparum. Angiotensin II (Ang II) reduced erythrocyte invasion in an enriched schizont culture of P. falciparum in a dose-dependent manner. Using mass spectroscopy, we showed that Ang II was metabolized by erythrocytes to Ang IV and Ang-(1–7). Parasite infection decreased Ang-(1–7) and completely abolished Ang IV formation. Similar to Ang II, Ang-(1–7) decreased the level of infection in an A779 (specific antagonist of Ang-(1–7) receptor, MAS)-sensitive manner. 10−7 M PD123319, an AT2 receptor antagonist, partially reversed the effects of Ang-(1–7) and Ang II. However, 10−6 M losartan, an antagonist of the AT1 receptor, had no effect. Gs protein is a crucial player in the Plasmodium falciparum blood cycle and angiotensin peptides can modulate protein kinase A (PKA) activity; 10−8 M Ang II or 10−8 M Ang-(1–7) inhibited this activity in erythrocytes by 60% and this effect was reversed by 10−7 M A779. 10−6 M dibutyryl-cAMP increased the level of infection and 10−7 M PKA inhibitor decreased the level of infection by 30%. These results indicate that the effect of Ang-(1–7) on P. falciparum blood stage involves a MAS-mediated PKA inhibition. Our results indicate a crucial role for Ang II conversion into Ang-(1–7) in controlling the erythrocytic cycle of the malaria parasite, adding new functions to peptides initially described to be involved in the regulation of vascular tonus

    Impairment of the Plasmodium falciparum Erythrocytic Cycle Induced by Angiotensin Peptides

    Get PDF
    Plasmodium falciparum causes the most serious complications of malaria and is a public health problem worldwide with over 2 million deaths each year. The erythrocyte invasion mechanisms by Plasmodium sp. have been well described, however the physiological aspects involving host components in this process are still poorly understood. Here, we provide evidence for the role of renin-angiotensin system (RAS) components in reducing erythrocyte invasion by P. falciparum. Angiotensin II (Ang II) reduced erythrocyte invasion in an enriched schizont culture of P. falciparum in a dose-dependent manner. Using mass spectroscopy, we showed that Ang II was metabolized by erythrocytes to Ang IV and Ang-(1–7). Parasite infection decreased Ang-(1–7) and completely abolished Ang IV formation. Similar to Ang II, Ang-(1–7) decreased the level of infection in an A779 (specific antagonist of Ang-(1–7) receptor, MAS)-sensitive manner. 10−7 M PD123319, an AT2 receptor antagonist, partially reversed the effects of Ang-(1–7) and Ang II. However, 10−6 M losartan, an antagonist of the AT1 receptor, had no effect. Gs protein is a crucial player in the Plasmodium falciparum blood cycle and angiotensin peptides can modulate protein kinase A (PKA) activity; 10−8 M Ang II or 10−8 M Ang-(1–7) inhibited this activity in erythrocytes by 60% and this effect was reversed by 10−7 M A779. 10−6 M dibutyryl-cAMP increased the level of infection and 10−7 M PKA inhibitor decreased the level of infection by 30%. These results indicate that the effect of Ang-(1–7) on P. falciparum blood stage involves a MAS-mediated PKA inhibition. Our results indicate a crucial role for Ang II conversion into Ang-(1–7) in controlling the erythrocytic cycle of the malaria parasite, adding new functions to peptides initially described to be involved in the regulation of vascular tonus
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