436 research outputs found
Four problems regarding representable functors
Let , be two rings, an -coring and the
category of left -comodules. The category of all representable functors is shown to be equivalent to the opposite of the
category . For an -bimodule we give
necessary and sufficient conditions for the induction functor to be: a representable functor, an
equivalence of categories, a separable or a Frobenius functor. The latter
results generalize and unify the classical theorems of Morita for categories of
modules over rings and the more recent theorems obtained by Brezinski,
Caenepeel et al. for categories of comodules over corings.Comment: 16 pages, the second versio
Hopf Categories
We introduce Hopf categories enriched over braided monoidal categories. The
notion is linked to several recently developed notions in Hopf algebra theory,
such as Hopf group (co)algebras, weak Hopf algebras and duoidal categories. We
generalize the fundamental theorem for Hopf modules and some of its
applications to Hopf categories.Comment: 47 pages; final version to appear in Algebras and Representation
Theor
World Association for the Advancement of Veterinary Parasitology (WAAVP) guideline: anthelmintic combination products targeting nematode infections of ruminants and horses
Increasing threats from anthelmintic resistant nematode populations warrant and motivate a reappraisal of chemotherapeutic strategies for nematode control in ruminant livestock and horses. The objective of this paper is to present a guideline for the evaluation of products containing two or more constituent anthelmintic actives in a single dosage form for the treatment of nematode infections in these animals. At present, regulatory policies on the approval of such products vary across jurisdictions, and this World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guideline should enable the harmonization of the requirements. This guideline makes clear recommendations on the minimal standards needed, but stresses that registration dossiers for combination anthelmintic products submitted for approval must conform to the standards and practices already established in existing guidelines for anthelmintics
Systematic review of studies generating individual participant data on the efficacy of drugs for treating soil-transmitted helminthiases and the case for data-sharing
Preventive chemotherapy and transmission control (PCT) by mass drug administration is the cornerstone of the World Health Organization (WHO)’s policy to control soil-transmitted helminthiases (STHs) caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm) and hookworm species (Necator americanus and Ancylostama duodenale) which affect over 1 billion people globally. Despite consensus that drug efficacies should be monitored for signs of decline that could jeopardise the effectiveness of PCT, systematic monitoring and evaluation is seldom implemented. Drug trials mostly report aggregate efficacies in groups of participants, but heterogeneities in design complicate classical meta-analyses of these data. Individual participant data (IPD) permit more detailed analysis of drug efficacies, offering increased sensitivity to identify atypical responses potentially caused by emerging drug resistance
Suitability of pesticide risk indicators for less developed countries: a comparison
Pesticide risk indicators provide simple support in the assessment of environmental and health risks
from pesticide use, and can therefore inform policies to foster a sustainable interaction of agriculture
with the environment. For their relative simplicity, indicators may be particularly useful under conditions
of limited data availability and resources, such as in Less Developed Countries (LDCs). However,
indicator complexity can vary significantly, in particular between those that rely on an exposure–toxicity
ratio (ETR) and those that do not. In addition, pesticide risk indicators are usually developed for Western
contexts, which might cause incorrect estimation in LDCs. This study investigated the appropriateness
of seven pesticide risk indicators for use in LDCs, with reference to smallholding agriculture in Colombia.
Seven farm-level indicators, among which 3 relied on an ETR (POCER, EPRIP, PIRI) and 4 on a non-ETR
approach (EIQ, PestScreen, OHRI, Dosemeci et al., 2002), were calculated and then compared by means
of the Spearman rank correlation test. Indicators were also compared with respect to key indicator characteristics,
i.e. user friendliness and ability to represent the system under study. The comparison of the
indicators in terms of the total environmental risk suggests that the indicators not relying on an ETR
approach cannot be used as a reliable proxy for more complex, i.e. ETR, indicators. ETR indicators, when
user-friendly, show a comparative advantage over non-ETR in best combining the need for a relatively
simple tool to be used in contexts of limited data availability and resources, and for a reliable estimation
of environmental risk. Non-ETR indicators remain useful and accessible tools to discriminate between
different pesticides prior to application. Concerning the human health risk, simple algorithms seem more
appropriate for assessing human health risk in LDCs. However, further research on health risk indicators
and their validation under LDC conditions is needed
Field Validity and Feasibility of Four Techniques for the Detection of Trichuris in Simians: A Model for Monitoring Drug Efficacy in Public Health?
Worldwide, millions of people are infected with soil-transmitted helminths, particularly in developing countries. Efforts to control these infections involve periodic mass drug treatment in endemic areas. Since these large-scale interventions are likely to intensify, monitoring of drug efficacy has become a key issue in order to detect the emergence of resistance. At present, the drop in infection intensity is under examination for monitoring the drug efficacy. However, studies comparing detection techniques based on infection intensities are scarce. Moreover, little attention has been addressed to their feasibility and their ability to estimate drug efficacies. We have compared different techniques for the detection of whipworm (Trichuris) in simian stool samples based on prevalence, infection intensities, feasibility and ability to estimate the ‘true’ drug efficacy. We have found that techniques often fail to detect low infection intensities and that not all techniques are appropriate for estimating infection intensities. The time needed to obtain a test result varied from 3.9 to 17.7 min/sample. Finally, accurate estimates of drug efficacy were only obtained in high pre-drug administration infection intensities. To conclude, along with accurate estimates of infection intensities, feasibility is a considerable criterion for the detection techniques used in drug efficacy monitoring programs
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