536 research outputs found

    Bionomy and Nesting Behavior of the Bee Epanthidium tigrinum (Schrottky, 1905) (Hymenoptera: Megachilidae) in Trap-Nests

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    About 85% of pollinating bees are solitary, but few are used for agricultural pollination. The Anthidiini tribe looks very promising in Brazil, in the light of ecosystem utility, but  it is still a species with poorly scientific research[EdM1] . To fill this gap studies on the bionomics of this species may collaborate on future studies on use of Epanthidium tigrinum as pollinator. Presented research results aims to describe the bionomy and the biological cycle of the bee E. tigrinum (SCHROTTKY, 1905) in pre-existing cavities. Conventional trap-nests inserted in wooden blocks were placed in covered spaces and daily observations of spontaneous nesting as well as individually tagged bees and nests incubated in B.O.D. were carried out during 11 months in Fortaleza-CE. The results showed that the competition with other species of bees for the pre-existing cavities and the lack of food resources or nest building materials are limiting factors for the establishment of E. tigrinum populations. However, once these problems were remedied, the bees showed multivoltine behavior, nesting throughout the experimental period. Data from 16 nests studied showed that bee foraging began on average at 7:50 a.m., foragers collected pollen in the morning and resin in the afternoon, took on average 15 days to complete a nest and there was a negative correlation with the temperature for the number of nests and for the number of cells constructed. The offspring took 43 days for the emergency, presented sexual ratio of 1.2: 1 (n = 66 emerged bees) and a mortality rate of 18.5%. The number of nests constructed per female ranged from 1 to 4 with an average size of 7.97 mm. It is concluded that E. tigrinum shows potential to rational rearing in trap nests aiming crop pollination. [EdM1

    Pollen Niche from Tetrapedia diversipes Klug (Hymenoptera: Apidae: Tetrapediini) in a Brazilian Semi-deciduous Lowland Forest

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    Tetrapedia diversipes Klug (Apidae) is a solitary bee with wide geographical distribution. Females of this species usually nest in pre-existing cavities and although their biology is relatively well known, studies on their trophic niche are still scarce. Thus, the present study aimed to identify the plant species used in the diet of immature T. diversipes through the analysis of residual pollen material. The nests used in the study were obtained through the use of trap nests during the period between December 2014 and October 2015, distributed in an area of coastal forest in northeastern Brazil. For the study of the trophic niche, samples of post-emergency residue (feces) from cells of offspring of males (n = 31) and females (n = 66) of T. diversipes were analyzed. In total, 29 pollen types were identified in the feeding of T. diversipes, being of the pollen types identified, only seven were not used by both sexes. Although a significant difference was found in the amplitude in the trophic niche between the sexes, there was a high overlap for Horn-Morisita index (CH = 0.989), with no significant difference being found in the frequency distribution of male and female food items (D = 0.214; p = 0.341). In this study we concluded that the diet of T. diversipes in coastal forest is polyletic, similarly to the pattern found in other studies of pollen resources in different vegetation in Brazil, with a predominance of pollen from the families Euphorbiaceae, Asteraceae and Onagraceae

    Distinct variation in vector competence among nine field populations of Aedes aegypti from a Brazilian dengue-endemic risk city

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    Background: In Brazil, dengue epidemics erupt sporadically throughout the country and it is unclear if outbreaks may initiate a sustainable transmission cycle. There are few studies evaluating the ability of Brazilian Aedes aegypti populations to transmit dengue virus (DENV). The aim of this study was to compare DENV susceptibility of field-captured Ae. aegypti populations from nine distinct geographic areas of the city of Belo Horizonte in 2009 and 2011. Infection Rate (IR), Vector Competence (VC) and Disseminated Infection Rate (DIR) were determined. Methods: Aedes aegypti eggs from each region were collected and reared separately in an insectary. Adult females were experimentally infected with DENV-2 and the virus was detected by qPCR in body and head samples. Data were analyzed with the Statistical Package for the Social Sciences version 17. Results: IR varied from 40.0% to 82.5% in 2009 and 60.0% to 100.0% in 2011. VC ranged from 25.0% to 77.5% in 2009 and 25.0% to 80.0% in 2011. DIR oscillated from 68.7% to 100.0% in 2009 and 38.4% to 86.8 in 2011. When the results were evaluated by a logistic model using IR as covariate, North, Barreiro, South-Central and Venda Nova showed the strongest association in 2009. In 2011, a similar association was observed for South-Central, Venda Nova, West and Northeast regions. Using VC as covariate, South-Central and Venda Nova showed the most relevant association in 2009. In 2011, South-Central, Venda Nova and Barreiro presented the greatest revelation associations. When DIR data were analyzed by logistic regression models, Pampulha, South-Central, Venda Nova, West, Northeast and East (2009) as well as South-Central, Venda Nova and West (2011) were the districts showing the strongest associations. Conclusions: We conclude that Ae. aegypti populations from Belo Horizonte exhibit wide variation in vector competence to transmit dengue. Therefore, vector control strategies should be adapted to the available data for each region. Further analysis should be conducted to better understand the reasons for this large variability in vector competence and how these parameters correlate with epidemiological findings in subsequent years

    Factors Associated with Quality of Life in Patients with Systemic Arterial Hypertension

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    Background: Hypertensive patients present, in addition to worse cardiovascular health, lower health-related quality of life compared to normotensive subjects. Factors such as functional capacity, functional status, pain, participation in social activities, mental and emotional health, fatigue and energy level, along with perception of general health, seem to be relevant for evaluation in this population. However, evidence is unclear in hypertensive patients. Objective: To analyze the factors associated with quality of life in hypertensive patients. Methods: Forty-five patients were recruited. The dependent variables of the present study are the quality of life domains. Demographic data and clinical conditions were considered independent variables. The Medical Outcomes Short-Form Health Survey (SF-36) questionnaire was used to measure quality of life. Handgrip strength, blood pressure and anthropometric indicators were evaluated. Crude and adjusted linear regression analysis was used. Results: It was verified that education level, body mass index and muscle strength were associated with the functional capacity domain (p < 0,05), whereas systolic blood pressure was associated with the physical domain (p < 0,05). Women presented lower quality of life on the pain domain compared to men and educational level was associated with the social domain (p < 0,05). Conclusion: Hypertensive patients with lower levels of body mass index, higher levels of education and muscle strength presented a better quality of life on the physical domain, while the social aspects presented a positive relationship with education level. Women presented a worse quality of life on the pain domain compared to men

    A tetravalent dengue nanoparticle stimulates antibody production in mice

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    <p>Abstract</p> <p>Background</p> <p>Dengue is a major public health problem worldwide, especially in the tropical and subtropical regions of the world. Infection with a single <it>Dengue virus </it>(DENV) serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients experiencing secondary infection with a different serotype progresses to the severe form of the disease, dengue hemorrhagic fever/dengue shock syndrome. Currently, there are no licensed vaccines or antiviral drugs to prevent or treat dengue infections. Biodegradable nanoparticles coated with proteins represent a promising method for in vivo delivery of vaccines.</p> <p>Findings</p> <p>Here, we used a murine model to evaluate the IgG production after administration of inactivated DENV corresponding to all four serotypes adsorbed to bovine serum albumin nanoparticles. This formulation induced a production of anti-DENV IgG antibodies (p < 0.001). However, plaque reduction neutralization assays with the four DENV serotypes revealed that these antibodies have no neutralizing activity in the dilutions tested.</p> <p>Conclusions</p> <p>Our results show that while the nanoparticle system induces humoral responses against DENV, further investigation with different DENV antigens will be required to improve immunogenicity, epitope specicity, and functional activity to make this platform a viable option for DENV vaccines.</p

    Association of molecular senescence markers in late-life depression with clinical characteristics and treatment outcome

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    Importance: Many older adults with depression do not experience remission with antidepressant treatment, and markers of cellular senescence in late-life depression (LLD) are associated with greater severity of depression, greater executive dysfunction, and higher medical illness burden. Since these clinical characteristics are associated with remission in LLD, molecular and cellular senescence abnormalities could be a possible biological mechanism underlying poor treatment response in this population. Objective: To examine whether the senescence-associated secretory phenotype (SASP) index was associated with the likelihood of remission from a depressive episode in older adults. Design, Setting, and Participants: A nonrandomized, open-label clinical trial was conducted between August 2009 and August 2014 in Pittsburgh, Pennsylvania; St Louis, Missouri; and Toronto, Ontario, Canada, with older adults in a current major depressive episode according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) diagnostic criteria. Data from biomarker analyses were reported according to the clinical trial archived plasma samples run in March 2021. Data were analyzed from June to November 2021. Exposure: Venlafaxine extended release (dose ranging from 37.5 mg to 300 mg daily) for up to 12 weeks. Main Outcomes and Measures: The association between a composite biomarker-based index (SASP index) and treatment remission in older adults with major depression was measured using clinical data and blood samples. Results: There were 416 participants with a mean (SD) age of 60.02 (7.13) years; 64% (265 participants) were self-reported female, and the mean (SD) Montgomery-Asberg Depression Rating Scale score was 26.6 (5.7). Higher SASP index scores were independently associated with higher rates of nonremission, with an increase of 1 unit in the SASP index score increasing the odds of nonremission by 19% (adjusted odds ratio, 1.19; 95% CI, 1.05-1.35; P = .006). In contrast, no individual SASP factors were associated with remission in LLD. Conclusions and Relevance: Using clinical data and blood samples from a nonrandomized clinical trial, the results of this study suggest that molecular and cellular senescence, as measured with the SASP index, is associated with worse treatment outcomes in LLD. Combining this index score reflecting interrelated biological processes with other molecular, clinical, and neuroimaging markers may be useful in evaluating antidepressant treatment outcomes. These findings inform a path forward for geroscience-guided interventions targeting senescence to improve remission rates in LLD. Trial Registration: ClinicalTrials.gov Identifier: NCT00892047

    Is there cardiac autonomic dysfunction in children and adolescents with exercise-induced bronchospasm?

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    The pulmonary impairment in patients with bronchoconstriction induced by eucapnic voluntary hyperpnea(EVH) goes beyond the respiratory system, also impairing autonomic nervous modulation. This study aimed to evaluate the behavior of cardiac autonomic modulation in young asthmatics with and without EIB after the EVH test. Research design and methods A cross-sectional study design using 54 asthmatics(51.9% female), aged between 10 and 19 years, investigated with the EVH test. Forced expiratory volume in one second(FEV1) was measured at 5, 10, 15, and 30 min after EVH. Heart rate variability(HRV) measures of time were assessed pre and 30 min-post EVH. The diagnosis of Exercise-Induced bronchoconstriction with underlying clinical asthma(EIBA) was confirmed by a fall in FEV1 ≥10% compared to baseline. Results Thirty(55.5%) asthmatics had EIBA. Subjects with EIBA have reduced mean of the R-R intervals in relation to baseline until 15 minutes after EVH. Individuals without EIBA had increased parasympathetic activity compared to baseline(rMSSD) from 5 min after EVH(p < 0.05). This parasympathetic activity increase in relation to baseline was seen in individuals with EIBA after 25 minutes (rMSSD = 49.9 ± 5.3 vs 63.5 ± 7.2, p < 0.05). Conclusion Young asthmatics with EIBA present a delay in the increase of the parasympathetic component after EVH when compared to asthmatics without EIBA

    Biocides used as additives to biodiesels and their risks to the environment and public health : a review

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    One of the advantages of using biodiesel and its blends with diesel oil is the lower levels of emissions of particulate matter, sulfur dioxide, carbon monoxide, among others, making it less harmful to the environment and to humans. However, this biofuel is susceptible to microbial contamination and biodeterioration. In this sense, studies on the use of effective low toxicity biocides are being carried out, and this work aims to present the latest information (2008–2018) available in the scientific databases, on the use of biocides in biodiesel, mainly concerning their toxicity to the environment and public health. The results showed that in relation to the control of microbial contamination, the current scenario is limited, with seven publications, in which the most studied additives were isothiazolinones, oxazolidines, thiocyanates, morpholines, oxaborinanes, thiocarbamates and phenolic antioxidants. Studies regarding direct experiments with humans have not been found, showing the need for more studies in this area, since the potential growth of biodiesel production and consumption in the world is evident. Thus, there are need for more studies on antimicrobial products for use in biodiesel, with good broad-spectrum activity (bactericidal and fungicidal), and further toxicological tests to ensure no or little impact on the environment

    Evaluation of the efficacy and safety of endovascular management for transplant renal artery stenosis

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    OBJECTIVES: To evaluate the safety and efficacy of endovascular intervention with angioplasty and stent placement in patients with transplant renal artery stenosis. METHODS: All patients diagnosed with transplant renal artery stenosis and graft dysfunction or resistant systemic hypertension who underwent endovascular treatment with stenting from February 2011 to April 2016 were included in this study. The primary endpoint was clinical success, and the secondary endpoints were technical success, complication rate and stent patency. RESULTS: Twenty-four patients with transplant renal artery stenosis underwent endovascular treatment, and three of them required reinterventions, resulting in a total of 27 procedures. The clinical success rate was 100%. All graft dysfunction patients showed decreased serum creatinine levels and improved estimated glomerular filtration rates and creatinine levels. Patients with high blood pressure also showed improved control of systemic blood pressure and decreased use of antihypertensive drugs. The technical success rate of the procedure was 97%. Primary patency and assisted primary patency rates at one year were 90.5% and 100%, respectively. The mean follow-up time of patients was 794.04 days after angioplasty. CONCLUSION: Angioplasty with stent placement for the treatment of transplant renal artery stenosis is a safe and effective technique with good results in both the short and long term
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