392 research outputs found

    Wolbachia in the flesh: symbiont intensities in germ-line and somatic tissues challenge the conventional view of Wolbachia transmission routes

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    Symbionts can substantially affect the evolution and ecology of their hosts. The investigation of the tissue-specific distribution of symbionts (tissue tropism) can provide important insight into host-symbiont interactions. Among other things, it can help to discern the importance of specific transmission routes and potential phenotypic effects. The intracellular bacterial symbiont Wolbachia has been described as the greatest ever panzootic, due to the wide array of arthropods that it infects. Being primarily vertically transmitted, it is expected that the transmission of Wolbachia would be enhanced by focusing infection in the reproductive tissues. In social insect hosts, this tropism would logically extend to reproductive rather than sterile castes, since the latter constitute a dead-end for vertically transmission. Here, we show that Wolbachia are not focused on reproductive tissues of eusocial insects, and that non-reproductive tissues of queens and workers of the ant Acromyrmex echinatior, harbour substantial infections. In particular, the comparatively high intensities of Wolbachia in the haemolymph, fat body, and faeces, suggest potential for horizontal transmission via parasitoids and the faecal-oral route, or a role for Wolbachia modulating the immune response of this host. It may be that somatic tissues and castes are not the evolutionary dead-end for Wolbachia that is commonly thought

    Consumer involvement in dietary guideline development: opinions from European stakeholders.

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    OBJECTIVE: The involvement of consumers in the development of dietary guidelines has been promoted by national and international bodies. Yet, few best practice guidelines have been established to assist with such involvement. DESIGN: Qualitative semi-structured interviews explored stakeholders' beliefs about consumer involvement in dietary guideline development. SETTING: Interviews were conducted in six European countries: the Czech Republic, Germany, Norway, Serbia, Spain and the UK. SUBJECTS: Seventy-seven stakeholders were interviewed. Stakeholders were grouped as government, scientific advisory body, professional and academic, industry or non-government organisations. Response rate ranged from 45 % to 95 %. RESULTS: Thematic analysis was conducted with the assistance of NVivo qualitative software. Analysis identified two main themes: (i) type of consumer involvement and (ii) pros and cons of consumer involvement. Direct consumer involvement (e.g. consumer organisations) in the decision-making process was discussed as a facilitator to guideline communication towards the end of the process. Indirect consumer involvement (e.g. consumer research data) was considered at both the beginning and the end of the process. Cons to consumer involvement included the effect of vested interests on objectivity; consumer disinterest; and complications in terms of time, finance and technical understanding. Pros related to increased credibility and trust in the process. CONCLUSIONS: Stakeholders acknowledged benefits to consumer involvement during the development of dietary guidelines, but remained unclear on the advantage of direct contributions to the scientific content of guidelines. In the absence of established best practice, clarity on the type and reasons for consumer involvement would benefit all actors

    Research for PECH Committee - Discard ban, landing obligation and MSY in the Western Mediterranean Sea - the Spanish case

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    The demersal fisheries in the Mediterranean Sea are heavily overfished but the landing obligation will not help to reach MSY because it will not decrease fishing mortality. The new proposal of the Commission introduces total allowable effort as a new way to regulate Western Mediterranean demersal fisheries by significantly reducing fishing time. However, this new management measure must be complemented with increased gear selectivity, implementation of closed areas and local co-management plans. Different approaches to reduce fishing mortality may have different socio-economic impact

    Physiological and public health basis for assessing micronutrient requirements in children and adolescents. The EURRECA network

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    This paper provides an overview of the current knowledge relating to the nutritional requirements and corresponding recommended nutrient intake values of children and adolescents for micronutrients and specificities related to these requirements in the course of childhood and adolescence in Europe. Aspects that can influence micronutrient requirements, such as physiological requirements and bioavailability of the nutrients in the organism, are discussed. The methodology used to obtain the data and also the main knowledge gaps regarding these concepts are emphasized. Methodological critical points in achieving the data and physiological aspects of children and adolescents are important in order to standardize the reference values for micronutrients among Europe for these stages of life

    Distinct tau prion strains propagate in cells and mice and define different tauopathies

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    Prion-like propagation of tau aggregation might underlie the stereotyped progression of neurodegenerative tauopathies. True prions stably maintain unique conformations (“strains”) in vivo that link structure to patterns of pathology. We now find that tau meets this criterion. Stably expressed tau repeat domain indefinitely propagates distinct amyloid conformations in a clonal fashion in culture. Reintroduction of tau from these lines into naive cells reestablishes identical clones. We produced two strains in vitro that induce distinct pathologies in vivo as determined by successive inoculations into three generations of transgenic mice. Immunopurified tau from these mice recreates the original strains in culture. We used the cell system to isolate tau strains from 29 patients with 5 different tauopathies, finding that different diseases are associated with different sets of strains. Tau thus demonstrates essential characteristics of a prion. This might explain the phenotypic diversity of tauopathies and could enable more effective diagnosis and therapy

    Implicit trust in clinical decision-making by multidisciplinary teams

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    In clinical practice, decision-making is not performed by individual knowers but by an assemblage of people and instruments in which no one member has full access to every piece of evidence. This is due to decision making teams consisting of members with different kinds of expertise, as well as to organisational and time constraints. This raises important questions for the epistemology of medicine, which is inherently social in this kind of setting, and implies epistemic dependence on others. Trust in these contexts is a highly complex social practice, involving different forms of relationships between trust and reasons for trust: based on reasons, and not based on reasons; based on reasons that are easily accessible to reflection and others that are not. In this paper, we focus on what it means to have reasons to trust colleagues in an established clinical team, collectively supporting or carrying out every day clinical decision-making. We show two important points about these reasons, firstly, they are not sought or given in advance of a situation of epistemic dependence, but are established within these situations; secondly they are implicit in the sense of being contained or nested within other actions that are not directly about trusting another person. The processes of establishing these reasons are directly about accomplishing a task, and indirectly about trusting someone else’s expertise or competence. These processes establish a space of reasons within which what it means to have reasons for trust, or not, gains a meaning and traction in these team-work settings. Based on a qualitative study of decision-making in image assisted diagnosis and treatment of a complex disease called pulmonary hypertension (PH), we show how an intersubjective framework, or ‘space of reasons’ is established through team members forging together a common way of identifying and dealing with evidence. In dealing with images as a central diagnostic tool, this also involves a common way of looking at the images, a common mode or style of perception. These frameworks are developed through many iterations of adjusting and calibrating interpretations in relation to those of others, establishing what counts as evidence, and ranking different kinds of evidence. Implicit trust is at work throughout this process. Trusting the expertise of others in clinical decision-making teams occurs while the members of the team are busy on other tasks, most importantly, building up a framework of common modes of seeing, and common ways of identifying and assessing evidence emerge. It is only in this way that trusting or mistrusting becomes meaningful in these contexts, and that a framework for epistemic dependence is established
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