503 research outputs found
Both cetaceans in the Brazilian Amazon show sustained, profound population declines over two decades
<div><p>Obligate river dolphins occur only in the rivers of Asia and South America, where they are increasingly subject to damaging pressures such as habitat degradation, food competition and entanglement in fishing gear as human populations expand. The Amazon basin hosts two, very different, dolphins—the boto or Amazon river dolphin (<i>Inia geoffrensis</i>) and the smaller tucuxi (<i>Sotalia fluviatilis</i>). Both species have wide geographical ranges and were once considered to be relatively abundant. Their IUCN Red List conservation status of Data Deficient (DD), due to limited information on threats, ecology, population numbers and trends, did not initially cause alarm. However, the development of dolphin hunting to provide fish bait at around the beginning of this millennium broadly coincided with the onset of a widespread perception that numbers of both species were in decline. Consequently, the need for population trend data to inform conservation advice and measures became urgent. This paper presents a 22-year time series of standardised surveys for both dolphins within the Mamirauá Reserve, Amazonas State, Brazil. Analysis of these data show that both species are in steep decline, with their populations halving every 10 years (botos) and 9 years (tucuxis) at current rates. These results are consistent with published, independent information on survival rates of botos in this area, which demonstrated a substantial drop in annual survival, commencing at around the year 2000. Mamirauá is a protected area, and is subject to fewer environmental pressures than elsewhere in the region, so there is no reason to suspect that the decline in dolphins within the Reserve is more pronounced than outside it. If South America's freshwater cetaceans are to avoid following their Asian counterparts on the path to a perilous conservation status, effective conservation measures are required immediately. Enforcement of existing fishery laws would greatly assist in achieving this.</p></div
Two-Parton Contribution to the Heavy-Quark Forward-Backward Asymmetry in NNLO QCD
Forward-backward asymmetries, , are important observables for the
determination of the neutral-current couplings of heavy quarks in inclusive
heavy quark production, . In view of the
measurement perspectives on at a future linear collider, precise
predictions of are required for massive quarks. We compute the
contribution of the final state to to order \as^2 in
the QCD coupling. We provide general formulae, and we show that this
contribution to is infrared-finite. We evaluate these two-parton
contributions for and quarks on and near the resonance, and for
quarks above threshold. Moreover, near the threshold we obtain, by
expanding in the heavy-quark velocity , an expression for to order \as^2 and NNLL in . This quantity is equal, to this
order in , to the complete forward-backward asymmetry .Comment: latex, 26 pages, 2 tables, 17 figure
Prolonged use of Kinesiotaping does not enhance functional performance and joint proprioception in healthy young males: Randomized controlled trial
S6Ks isoforms contribute to viability, migration, docetaxel resistance and tumor formation of prostate cancer cells
Background: The S6 Kinase (S6K) proteins are some of the main downstream effectors of the mammalian Target Of Rapamycin (mTOR) and act as key regulators of protein synthesis and cell growth. S6K is overexpressed in a variety of human tumors and is correlated to poor prognosis in prostate cancer. Due to the current urgency to identify factors involved in prostate cancer progression, we aimed to reveal the cellular functions of three S6K isoforms-p70-S6K1, p85-S6K1 and p54-S6K2-in prostate cancer, as well as their potential as therapeutic targets. Methods: In this study we performed S6K knockdown and overexpression and investigated its role in prostate cancer cell proliferation, colony formation, viability, migration and resistance to docetaxel treatment. In addition, we measured tumor growth in Nude mice injected with PC3 cells overexpressing S6K isoforms and tested the efficacy of a new available S6K1 inhibitor in vitro. Results: S6Ks overexpression enhanced PC3-luc cell line viability, migration, resistance to docetaxel and tumor formation in Nude mice. Only S6K2 knockdown rendered prostate cancer cells more sensitive to docetaxel. S6K1 inhibitor PF-4708671 was particularly effective for reducing migration and proliferation of PC3 cell line. Conclusions: These findings demonstrate that S6Ks play an important role in prostate cancer progression, enhancing cell viability, migration and chemotherapy resistance, and place both S6K1 and S6K2 as a potential targets in advanced prostate cancer. We also provide evidence that S6K1 inhibitor PF-4708671 may be considered as a potential drug for prostate cancer treatment16CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2012/13558-
Snake Venom: Any Clue for Antibiotics and CAM?
Lately several naturally occurring peptides presenting antimicrobial activity have been described in the literature. However, snake venoms, which are an enormous source of peptides, have not been fully explored for searching such molecules. The aim of this work is to review the basis of antimicrobial mechanisms revealing snake venom as a feasible source for searching an antibiotic prototype. Therefore, it includes (i) a description of the constituents of the snake venoms involved in their main biological effects during the envenomation process; (ii) examples of snake venom molecules of commercial use; (iii) mechanisms of action of known antibiotics; and (iv) how the microorganisms can be resistant to antibiotics. This review also shows that snake venoms are not totally unexplored sources for antibiotics and complementary and alternative medicine (CAM)
Lamivudine’s hypersensitivity in an HIV infected patient: case report
Importância do problema: Relatar um caso de hipersensibilidade à lamivudina, droga considerada segura e antirretroviral indicado como de primeira linha para início de tratamento para pacientes infectados pelo HIV. Comentários: É relatado o caso de paciente infectada pelo HIV que evoluiu com farmacodermia associada à terapia antirretroviral (TARV) utilizando tenofovir, lamivudina e efavirenz. Inicialmente, a hipersensibilidade foi atribuída ao efavirenz, pela maior incidência de eventos desta natureza com este medicamento e este foi substituído por fosamprenavir/ ritonavir. Apesar da substitui- ção, paciente desenvolveu síndrome de Stevens-Johnson. Foi hospitalizada e iniciou novo esquema, com introdução de droga a droga, com atazanavir/ritonavir, seguido de zidovudina e lamivudina, desenvolvendo manifestação de eritema multiforme após a última droga, sendo esta considerada a responsá- vel pela hipersensibilidadeRelevance: To report a case of hypersensitivity to lamivudine, a medicine that is considered safe and is indicated as part of the initial therapy for HIV infected patients. Comments: It is reported the evolution of an HIV patient who developed a drug eruption due to the following antirretroviral therapy: tenofovir, lamivudine and efavirenz. It initially was attributed to efavirenz, due to its higher incidence in these adverse reactions and it was replaced by fosamprenavir/ritonavir. In spite of the replacement, the patient developed Stevens-Johnson's Syndrome. She was hospitalized and began a new therapy with atazanavir/ritonavir, followed by zidovudine and lamivudine and presented a drug reaction with the last one, which was considered to be the responsible for the hypersensitivit
Optimization of plastic polymers for shellfish aquaculture infrastructures: in situ antifouling performance assessment
Biofouling poses a significant challenge to bivalve aquaculture affecting both the target culture and/or the immersed infrastructure. In suspended bivalve cultures (e.g., oysters and scallops), biofouling accumulation leads to additional labor demands and increased costs for the maintenance of underwater structures. Given that the inherent properties of materials used in farming infrastructure influence the formation of fouling communities, evaluating how these materials perform under diverse environmental conditions can help the industry select the most effective materials for preventing or minimizing biofouling growth. This study evaluates the impact of aquaculture material and environmental conditions on biofouling, focusing on two commonly used plastic polymers in marine aquaculture: polyamide (PA) and high-density polyethylene (PE). Both untreated and color-additive treated polymers were tested for their response to fouling development. Performance was gauged by total fouling wet weight and the extent of fouling-induced mesh occlusion. Experimental panels were deployed for 4 months (from May to September 2021) in estuarine (oyster farm) and marine (port) environments on the northern coast of Portugal. The marine sites exhibited greater fouling species diversity, while higher biofouling loads were found in the subtidal estuarine area. Within 3 months, complete mesh occlusion occurred mainly due to colonial hydroids (Obelia dichotoma) in the subtidal site. In contrast, panels deployed in the intertidal estuarine area had lower fouling biomass and mesh occlusion. Notably, significant differences between polymer types and treatments were only evident in the estuarine intertidal area, with long air exposure during low tide. White panels outperformed orange ones in fouling biomass, and PA panels outperformed PE panels in mesh occlusion. These differences were attributed to the settlement and growth of the acorn barnacle Austrominius modestus, known to favor dark-colored and less hydrophilic surfaces. Considering that oyster production in intertidal areas is one of the most important aquaculture industries globally, these findings offer valuable insights into material selection and characteristics that can mitigate fouling loads and their associated impacts. These results could also be relevant for other forms of bivalve aquaculture where infrastructure-related biofouling presents a challenge
Reactivation of latent HIV-1 in vitro using an ethanolic extract from Euphorbia umbellata (Euphorbiaceae) latex
Euphorbia umbellata (E. umbellata) belongs to Euphorbiaceae family, popularly known as Janauba, and its latex contains a combination of phorbol esters with biological activities described to different cellular protein kinase C (PKC) isoforms. Here, we identified deoxi-phorbol esters present in E. umbellata latex alcoholic extract that are able to increase HIV transcription and reactivate virus from latency models. This activity is probably mediated by NF-kB activation followed by nuclear translocation and binding to the HIV LTR promoter. In addition, E. umbellata latex extract induced the production of pro inflammatory cytokines in vitro in human PBMC cultures. This latex extract also activates latent virus in human PBMCs isolated from HIV positive patients as well as latent SIV in non-human primate primary CD4+ T lymphocytes. Together, these results indicate that the phorbol esters present in E. umbellata latex are promising candidate compounds for future clinical trials for shock and kill therapies to promote HIV cure and eradication.Research and experimental expenses were funded by the grant E26/2015064289 from FAPERJinfo:eu-repo/semantics/publishedVersio
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