423 research outputs found
Freshwater fungal diversity along an anthropogenic gradient in Hawaiian streams
Aquatic fungi play a pivotal role in detrital decomposition in freshwaters. The Hawaiian archipelago is the most geographically isolated group of islands on Earth, and knowledge about its aquatic fungal diversity is scarce. We assessed the diversity of fungi colonizing Hau leaves (Hibiscus tiliaceus) placed in 11 streams on Oahu, representing a gradient of anthropogenic pollution. Fungal diversity was assessed by high throughput sequencing of the internal transcribed spacer 2 region (ITS2) of rDNA. The majority of operational taxonomic units (OTUs) belonged to Ascomycota, and several species are new records for the Hawaiian archipelago. The number of OTUs varied by an order of magnitude between streams, and the structure of fungal communities also differ significantly between streams. Variables indicative of human influence, namely nutrient concentration in stream water and anthropogenic land cover, were strong correlates in the community ordination. Overall, human disturbance seems to be a driver of structural variability of fungal communities in Hawaiian streams
Characterization of the photosynthetic conditions and pigment profiles of the colour strains of Hypnea musciformis from field-collected and in vitro cultured samples
Articulando gênero e polÃtica: a proposta do coletivo de mulheres negras Anastácia Bantu
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Diet-induced Obesity In Rats Leads To A Decrease In Sperm Motility.
Obesity is rapidly becoming a worldwide epidemic that affects children and adults. Some studies have shown a relationship between obesity and infertility, but until now it remains controversial. Thus, the aim of the present study was to investigate the effect of high-fat diet-induced obesity on male reproductive parameters. In a first experiment, male Wistar rats were fed a high-fat diet (HFD) or standard chow (SD) for 15, 30 or 45 weeks, after which they were evaluated by adiposity index, serum leptin levels, reproductive organ weights and sperm counts. In a second experiment, rats received HFD or SD only for 15 weeks, long enough to cause obesity. Sexual hormones and sexual behavior were evaluated in these animals, as well as fertility after natural mating. Another group of rats was submitted to motility analysis and fertility evaluation after in utero insemination. After 15, 30 or 45 weeks, HFD-fed animals presented significant increases in obesity index and serum leptin levels. Reproductive organ weights and sperm counts in the testis and epididymis were similar between the two groups at all timepoints studied. Sexual behavior was not altered by the diet regimen, and HFD fertility after natural mating was also similar to SD-fed animals. Intergroup testosterone levels were also comparable, but estradiol levels were increased in HFD rats. Furthermore, sperm quality was reduced in HFD animals as evidenced by their decreased percentage of sperm with progressive movement. This altered motility parameter was followed by a trend toward reduction in fertility potential after artificial in utero insemination. The results reported herein showed that obesity can affect sperm quality, by reducing sperm motility, without affecting other sperm parameters. The low sperm quality caused a slight reduction in fertility potential, showing that obesity may lead to impairment in male fertility.93
Profiling microglia in a mouse model of Machado-Joseph disease
Microglia have been increasingly implicated in neurodegenerative diseases (NDs), and specific disease associated microglia (DAM) profiles have been defined for several of these NDs. Yet, the microglial profile in Machado–Joseph disease (MJD) remains unexplored. Here, we characterized the profile of microglia in the CMVMJD135 mouse model of MJD. This characterization was performed using primary microglial cultures and microglial cells obtained from disease-relevant brain regions of neonatal and adult CMVMJD135 mice, respectively. Machine learning models were implemented to identify potential clusters of microglia based on their morphological features, and an RNA-sequencing analysis was performed to identify molecular perturbations and potential therapeutic targets. Our findings reveal morphological alterations that point to an increased activation state of microglia in CMVMJD135 mice and a disease-specific transcriptional profile of MJD microglia, encompassing a total of 101 differentially expressed genes, with enrichment in molecular pathways related to oxidative stress, immune response, cell proliferation, cell death, and lipid metabolism. Overall, these results allowed us to define the cellular and molecular profile of MJD-associated microglia and to identify genes and pathways that might represent potential therapeutic targets for this disorder.This work was supported by Fundação para a Ciência e a Tecnologia (FCT) (PTDC/NEUNMC/3648/2014) and COMPETE-FEDER (POCI-01-0145-FEDER-016818). It was also supported
by Portuguese funds through FCT in the framework of the Project POCI-01-0145-FEDER-031987
(PTDC/MED-OUT/31987/2017). A.B.C. was supported by a doctoral fellowship from FCT (PD/BD/
127828/2016). S.P.N. was also supported by FCT (PD/BD/114120/2015). Work in the JBR laboratory
was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operational Programme for Competitiveness and Internationalization (POCI), Portugal
2020, and by Portuguese funds through FCT in the framework of the Project POCI-01-0145- FEDER030647 (PTDC/MED-NEU/31318/2017). This work was funded by ICVS Scientific Microscopy
Platform, member of the national infrastructure PPBI (Portuguese Platform of Bioimaging) (PPBIPOCI-01-0145-FEDER-022122), and by National funds, through FCT—project UIDB/50026/2020 and
UIDP/50026/2020
Heme oxygenase 1 improves glucoses metabolism and kidney histological alterations in diabetic rats
One important concern in the treatment of diabetes is the maintenance of glycemic levels and the prevention of diabetic nephropathy. Inducible heme oxygenase 1 (HO-1) is a rate-limiting enzyme thought to have antioxidant and cytoprotective roles. the goal of the present study was to analyze the effect of HO-1 induction in chronically hyperglycemic rats. the hyperglycemic rats were divided into two groups: one group, called STZ, was given a single injection of streptozotocin; and the other group was given a single streptozotocin injection as well as daily injections of hemin, an HO-1 inducer, over 60 days (STZ + HEME). A group of normoglycemic, untreated rats was used as the control (CTL).Body weight, diuresis, serum glucose levels, microalbuminuria, creatinine clearance rate, urea levels, sodium excretion, and lipid peroxidation were analyzed. Histological alterations and immunohistochemistry for HO-1 and inducible nitric oxide synthase (iNOS) were assessed. After 60 days, the STZ group exhibited an increase in blood glucose, diuresis, urea, microalbuminuria, and sodium excretion. There was no weight gain, and there was a decrease in creatinine clearance in comparison to the CTL group. in the STZ + HEME group there was an improvement in the metabolic parameters and kidney function, a decrease in blood glucose, serum urea, and microalbuminuria, and an increase of creatinine clearance, in comparison to the STZ group.There was glomerulosclerosis, collagen deposition in the STZ rats and increase in iNOS and HO-1 expression. in the STZ + HEME group, the glomerulosclerosis and fibrosis was prevented and there was an increase in the expression of HO-1, but decrease in iNOS expression and lipid peroxidation. in conclusion, our data suggest that chronic induction of HO-1 reduces hyperglycemia, improves glucose metabolism and, at least in part, protects the renal tissue from hyperglycemic injury, possibly through the antioxidant activity of HO-1.Universidade Federal de São Paulo UNIFESP, Div Nephrol, Dept Med, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Morphol Dept, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Div Nephrol, Dept Med, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Morphol Dept, São Paulo, BrazilWeb of Scienc
Blocking Zika virus vertical transmission.
The outbreak of the Zika virus (ZIKV) has been associated with increased incidence of congenital malformations. Although recent efforts have focused on vaccine development, treatments for infected individuals are needed urgently. Sofosbuvir (SOF), an FDA-approved nucleotide analog inhibitor of the Hepatitis C (HCV) RNA-dependent RNA polymerase (RdRp) was recently shown to be protective against ZIKV both in vitro and in vivo. Here, we show that SOF protected human neural progenitor cells (NPC) and 3D neurospheres from ZIKV infection-mediated cell death and importantly restored the antiviral immune response in NPCs. In vivo, SOF treatment post-infection (p.i.) decreased viral burden in an immunodeficient mouse model. Finally, we show for the first time that acute SOF treatment of pregnant dams p.i. was well-tolerated and prevented vertical transmission of the virus to the fetus. Taken together, our data confirmed SOF-mediated sparing of human neural cell types from ZIKV-mediated cell death in vitro and reduced viral burden in vivo in animal models of chronic infection and vertical transmission, strengthening the growing body of evidence for SOF anti-ZIKV activity
Firefly Penalty-based Algorithm for Bound Constrained Mixed-Integer Nonlinear Programming
In this article, we aim to extend the firefly algorithm (FA) to solve bound constrained mixedinteger nonlinear programming (MINLP) problems. An exact penalty continuous formulation of the MINLP problem is used. The continuous penalty problem comes out by relaxing the integrality constraints and by adding a penalty term to the objective function that aims to penalize integrality constraint violation. Two penalty terms are proposed, one is based on the hyperbolic tangent function and the other on the inverse hyperbolic sine function. We prove that both penalties can be used to define the continuous penalty problem, in the sense that it is equivalent to the MINLP problem. The solutions of the penalty problem are obtained using a variant of the metaheuristic FA for global optimization. Numerical experiments are given on a set of benchmark problems aiming to analyze the quality of the obtained solutions and the convergence speed. We show that the firefly penalty-based algorithm compares favorably with the penalty algorithm when the deterministic DIRECT or the simulated annealing solvers are invoked, in terms of convergence speed
Leaf-cutting ants toxicity of limonexic acid and degraded limonoids from Raulinoa echinata.: X-ray structure of epoxy-fraxinellone
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