262 research outputs found

    Transovarial Transmission of Babesia ovis by Rhipicephalus sanguineus and Hyalomma marginatum

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    Background: Rhipicephalus sanguineus and Hyalomma marginatum are the most common spe­cies in sheep herds in Northeast of Iran. There is preliminary evidence that these species may be the vectors of Babesia ovis in Iran. We carried out two experiments in Mashhad area, Khorasan Razavi Province to determine whether B. ovis could be transovarially transmitted by R. san­guineus and H. marginatum.Methods: In experiment 1, adults of laboratory reared H. marginatum and R.sanguineus were infected with B. ovis isolated from naturally infected sheep in Mashhad area by feeding the ticks on the sheep inoculated intravenously by infected blood samples. The inoculated sheep showed clinical signs with parasitaemia while the adult ticks were engorging on them. The engorged fe­males were collected and kept at 28°C and 85% relative humidity in incubator. Then, larval, nym­phal and adult stages derived from engorged females were used to infest the clean sheep. In experiment 2, two splenectomized sheep were infested only with the same adult ticks of two spe­cies.Results: Examination of smears and PCR of blood samples to detect of B. ovis in infested sheep in two experiments were negative.Conclusion: It seems that R. sanguineus and H. marginatum can not transovarially transmit B. ovis in sheep

    Competing for Information: A Duopoly of Personalized Service Provision under Privacy Concerns

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    There is “no free disposal” (NFD) in the consumption of online personalization services, as this activity inherently involves sharing of personal and preference information that creates disutilities to the consumer. Not only are more services not necessarily better for the consumer, but these services are also provided for free as firms extract value from the usage of consumer information rather than from directly pricing the services. Firms may offer personalization through a “take-it or leave-it” approach (the fixed-services strategy) or allow consumers to choose a subset of the portfolio of services offered (the variable-services strategy). We model a duopoly of firms that are heterogeneous in their marginal value for consumer information (MVI) and interact through a two-stage dynamic game, where the firms choose a fixed- or variable-services strategy in the first stage and the corresponding level of services in the second. Our findings suggest that when the MVIs of competing firms are sufficiently different, there is a unique subgame-perfect Nash equilibrium (SPNE) in pure strategies where both firms offer fixed-services such that they segment the market. As the difference in their MVIs increase, the high MVI firm continues to offer fixed-services while the low MVI firm enjoys the option of offering variable services. A duopoly of high MVI firms results in both firms offering variable services as long as one firm has very large MVI, and both offering fixed-services otherwise. Interestingly, while the former is consumer welfare maximizing, the latter results in a third of the market (consisting of privacy seekers) not being served. Our results lead to important managerial and policy implications, as well as interesting extensions to extant location models.published_or_final_versio

    The Problem of Mixing up of Leishmania Isolates in the Laboratory: Suggestion of ITS1 Gene Sequencing for Verification of Species

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    Background: Leishmaniasis is endemic in Iran. Different species of Leishmania (L.) parasites are causative agents of this disease. Correct identification of Leishmania species is important for clinical studies,prevention, and control of the diseases. Mix up of Leishmania isolates is possible in the laboratory, so there is need for verification of species for isolates of uncertain identity. Different methods may be used for this purpose including isoenzyme electrophoresis and molecular methods. The isoenzyme lectrophoresis, due to its drawbacks, is feasible only in specialized laboratories while molecular methods may be more feasible. The aim of this research was to study the application of the internal transcribedspacer 1 (ITS1) sequencing method, in comparison to isoenzyme electrophoresis method, for verification of Leishmania species.Methods: Six Leishmania isolates were received from different research institutions in Iran. The species of these isolates were known by donating institution according to their isoenzyme profile. The species of these isolates were re-identified in Pasteur Institute of Iran by PCR amplification of ITS1 followed bysequencing and comparison of these sequences with Leishmania sequences in GenBank. Isoenzyme electrophoresis was performed for confirmation of the results of ITS1.Results: ITS1 sequence showed that some isolates were mixed up or contaminated with Crithidia. Isoenzyme electrophoresis confirmed the results of ITS1 sequences.Conclusion: ITS1 sequencing is relatively more feasible than the traditional isoenzyme electrophoresismethod and is suggested for verification of Leishmania species

    CYP2C19 Genotype Prevalence and Association With Recurrent Myocardial Infarction in British–South Asians Treated With Clopidogrel

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    BACKGROUND: Cytochrome P450 family 2 subfamily C member 19 (CYP2C19) is a hepatic enzyme involved in the metabolism of clopidogrel from a prodrug to its active metabolite. Prior studies of genetic polymorphisms in CYP2C19 and their relationship with clinical efficacy have not included South Asian populations. OBJECTIVES: The objective of this study was to assess prevalence of common CYP2C19 genotype polymorphisms in a British-South Asian population and correlate these with recurrent myocardial infarction risk in participants prescribed clopidogrel. METHODS: The Genes & Health cohort of British Bangladeshi and Pakistani ancestry participants were studied. CYP2C19 diplotypes were assessed using array data. Multivariable logistic regression was used to test for association between genetically inferred CYP2C19 metabolizer status and recurrent myocardial infarction, controlling for known cardiovascular disease risk factors, percutaneous coronary intervention, age, sex, and population stratification. RESULTS: Genes & Health cohort participants (N = 44,396) have a high prevalence (57%) of intermediate or poor CYP2C19 metabolizers, with at least 1 loss-of-function CYP2C19 allele. The prevalence of poor metabolizers carrying 2 CYP2C19 loss-of-function alleles is 13%, which is higher than that in previously studied European (2.4%) and Central/South Asian populations (8.2%). Sixty-nine percent of the cohort who were diagnosed with an acute myocardial infarction were prescribed clopidogrel. Poor metabolizers were significantly more likely to have a recurrent myocardial infarction (OR: 3.1; P = 0.019). CONCLUSIONS: A pharmacogenomic-driven approach to clopidogrel prescribing has the potential to impact significantly on clinical management and outcomes in individuals of Bangladeshi and Pakistani ancestry

    Leibniz, Acosmism, and Incompossibility

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    Leibniz claims that God acts in the best possible way, and that this includes creating exactly one world. But worlds are aggregates, and aggregates have a low degree of reality or metaphysical perfection, perhaps none at all. This is Leibniz’s tendency toward acosmism, or the view that there this no such thing as creation-as-a-whole. Many interpreters reconcile Leibniz’s acosmist tendency with the high value of worlds by proposing that God sums the value of each substance created, so that the best world is just the world with the most substances. I call this way of determining the value of a world the Additive Theory of Value (ATV), and argue that it leads to the current and insoluble form of the problem of incompossibility. To avoid the problem, I read “possible worlds” in “God chooses the best of all possible worlds” as referring to God’s ideas of worlds. These ideas, though built up from essences, are themselves unities and so well suited to be the value bearers that Leibniz’s theodicy requires. They have their own value, thanks to their unity, and that unity is not preserved when more essences are added

    EuCARE-hospitalised study protocol: a cohort study of patients hospitalised with COVID-19 in the EuCARE project

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    Background: Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), can lead to hospitalisation, particularly in elderly, immunocompromised, and non-vaccinated or partially vaccinated individuals. Although vaccination provides protection, the duration of this protection wanes over time. Additional doses can restore immunity, but the influence of viral variants, specific sequences, and vaccine-induced immune responses on disease severity remains unclear. Moreover, the efficacy of therapeutic interventions during hospitalisation requires further investigation. The study aims to analyse the clinical course of COVID-19 in hospitalised patients, taking into account SARS-CoV-2 variants, viral sequences, and the impact of different vaccines. The primary outcome is all-cause in-hospital mortality, while secondary outcomes include admission to intensive care unit and length of stay, duration of hospitalisation, and the level of respiratory support required. Methods: This ongoing multicentre study observes hospitalised adult patients with confirmed SARS-CoV-2 infection, utilising a combination of retrospective and prospective data collection. It aims to gather clinical and laboratory variables from around 35,000 patients, with potential for a larger sample size. Data analysis will involve biostatistical and machine-learning techniques. Selected patients will provide biological material. The study started on October 14, 2021 and is scheduled to end on October 13, 2026. Discussion: The analysis of a large sample of retrospective and prospective data about the acute phase of SARS CoV-2 infection in hospitalised patients, viral variants and vaccination in several European and non-European countries will help us to better understand risk factors for disease severity and the interplay between SARS CoV-2 variants, immune responses and vaccine efficacy. The main strengths of this study are the large sample size, the long study duration covering different waves of COVID-19 and the collection of biological samples that allows future research. Trial registration: The trial has been registered on ClinicalTrials.gov. The unique identifier assigned to this trial is NCT05463380

    Respiratory research funding is inadequate, inequitable, and a missed opportunity

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    COVID-19 has placed respiratory medicine at the centre of health responses worldwide, but lung health was a major global challenge long before the current pandemic. More than 1000 people die of asthma and more than 2000 children die of pneumonia daily, and lung cancer is the most common cancer type in terms of incidence and mortality. Most of this enormous burden has fallen on people in the south and vulnerable populations in high-income economies. These are diseases of poverty, and disadvantages further compound inequity through increased disability, loss of productivity, and high health costs.1 As a major driver of ill health and poverty, the burden of respiratory disease remains a global rate-limiting step towards achieving health equity, economic growth, and Sustainable Development Goals.
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