11 research outputs found

    Trends in Taxonomy of the Rhodniini Tribe (Hemiptera, Triatominae): Reproductive Incompatibility between Rhodnius neglectus Lent, 1954 and Psammolestes spp. Confirms the Generic Status of Psammolestes Bergroth, 1911

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    The tribe Rhodniini is a monophyletic group composed of 24 species grouped in two genera: Rhodnius and Psammolestes. Rhodnius is a paraphyletic genus formed by 21 species. The event of paraphilia is supported by the greater evolutionary proximity of the species of the prolixus groups with the genus Psammolestes than with the other groups of Rhodnius. Based on this phenomenon, it was proposed the alteration of the genus of the species of Psammolestes to Rhodnius. Thus, we performed experimental crosses between Psammolestes spp. and R. neglectus to assess the degree of reproductive compatibility between Psammolestes and Rhodnius. Hybrids were not obtained for intergeneric crosses. Based on this, we have demonstrated that Rhodnius and Psammolestes have reproductive incompatibility. These data are important to confirm the validity of the specific status of Psammolestes, based on the biological concept of the species

    Karyotype Evolution in Triatominae (Hemiptera, Reduviidae): The Role of Chromosomal Rearrangements in the Diversification of Chagas Disease Vectors

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    Several cytogenetic studies have already been performed in Triatominae, such that different karyotypes could be characterized (ranging from 2n = 21 to 25 chromosomes), being the changes in the number of chromosomes related mainly to fusion and fission events. These changes have been associated with reproductive isolation and speciation events in other insect groups. Thus, we evaluated whether different karyotypes could act in the reproductive isolation of triatomines and we analyzed how the events of karyotypic evolution occurred along the diversification of these vectors. For this, experimental crosses were carried out between triatomine species with different karyotypes. Furthermore, based on a phylogeny with 88 triatomine taxa (developed with different molecular markers), a reconstruction of ancestral karyotypes and of anagenetic and cladogenetic events related to karyotypic alterations was performed through the ChromoSSE chromosomal evolution model. All crosses performed did not result in hybrids (prezygotic isolation in both directions). Our modeling results suggest that during Triatominae diversification, at least nine cladogenetic events may be associated with karyotype change. Thus, we emphasize that these alterations in the number of chromosomes can act as a prezygotic barrier in Triatominae (karyotypic isolation), being important evolutionary events during the diversification of the species of Chagas disease vectors

    Morphological, Cytological and Molecular Studies and Feeding and Defecation Pattern of Hybrids from Experimental Crosses between <i>Triatoma sordida</i> and <i>T. rosai</i> (Hemiptera, Triatominae)

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    Under laboratory conditions, Triatoma rosai and T. sordida are able to cross and produce hybrids. In the face of climate and environmental changes, the study of hybrids of triatomines has evolutionary and epidemiological implications. Therefore, we performed morphological, cytological and molecular studies and characterized the feeding and defecation pattern of hybrids from crosses between T. sordida and T. rosai. The morphological characterization of the female genitalia of the hybrids showed that characteristics of both parental species segregated in the hybrids. Cytogenetic analyzes of hybrids showed regular metaphases. According to molecular studies, the mitochondrial marker Cytochrome B (CytB) related the hybrids with T. sordida and the nuclear marker Internal Transcribed Spacer 1 (ITS-1) related the hybrids with T. rosai. Both parents and hybrids defecated during the blood meal. Thus, the hybrids resulting from the cross between T. sordida and T. rosai presented segregation of phenotypic characters of both parental species, 100% homeology between homeologous chromosomes, phylogenetic relationship with T sordida and with T. rosai (with CytB and ITS-1, respectively), and, finally, feeding and defecation patterns similar to the parents

    Você conhece a represa?

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    The Municipal Dam of São José do Rio Preto is located in downtown. As an aquatic environment inserted in the urban landscape it offers many ecosystem services such as water source and leisure location for population. Urban natural environments have been little considered in conservation projects, since they are seen only as urban facilities and not as ecosystems. This project aims bringing people to visit the park dam information about the aquatic ecosystem in order to develop an awareness of the ecosystem preservation. During several Sundays throughout the year at Dam Park we have presented present many ecological aspects of aquatic ecosystems (e.g.: the watershed, environmental conditions, plankton community, the fish community, the birds, etc.). People who participated in the project were distributed in all age groups. In individual reports, the words "health" and "life" were the most frequent, reflecting the view that the dam has high value to people's lives. The project has shown strong potential for the development of the natural environment conservation awareness of the dam.A Represa Municipal de São José do Rio Preto, localizada no centro da cidade, é um ambiente aquático inserido na paisagem urbana e oferece vários serviços ecossistêmicos, tais como fonte de água para abastecimento e local de lazer. Os ambientes naturais urbanos têm sido pouco considerados em projetos de conservação, uma vez que são vistos apenas como equipamentos urbanos e não como ecossistemas. Este projeto pretende levar à população que frequenta o parque da Represa informações sobre o ecossistema aquático da Represa, com o intuito de desenvolver nas pessoas a consciência da preservação do ecossistema. Durante vários domingos, ao longo do ano, serão realizadas exposições no parque da represa, onde são abordados vários aspectos ecológicos do ecossistema aquático (p.ex.: a bacia hidrográfica, as condições ambientais, a comunidade planctônica; a comunidade de peixes; as aves da represa e outros). As pessoas que participam do projeto estão distribuídas em todas as faixas etárias. Nos registros obtidos, as palavras 'saúde' e 'vida' foram as mais frequentes, refletindo a visão de que a represa tem alto valor para a vida das pessoas. O projeto tem demonstrado forte potencial para o desenvolvimento de uma consciência de conservação do ambiente natural da represa

    Soluble amyloid-β oligomers as synaptotoxins leading to cognitive impairment in Alzheimer’s disease

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    Characterisation of microbial attack on archaeological bone

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    As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

    Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

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    © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit
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