Causal mechanisms underlying host specificity in bat ectoparasites

In parasites, host specificity may result either from restricted dispersal capacity or from fixed coevolutionary host-parasite adaptations. Knowledge of those proximal mechanisms leading to particular host specificity is fundamental to understand host-parasite interactions and potential coevolution of parasites and hosts. The relative importance of these two mechanisms was quantified through infection and cross-infection experiments using mites and bats as a model. Monospecific pools of parasitic mites (Spinturnix myoti and S. andegavinus) were subjected either to individual bats belonging to their traditional, native bat host species, or to another substitute host species within the same bat genus (Myotis). The two parasite species reacted differently to these treatments. S. myoti exhibited a clear preference for, and had a higher fitness on, its native host, Myotis myotis. In contrast, S. andegavinus showed no host choice, although its fitness was higher on its native host M. daubentoni. The causal mechanisms mediating host specificity can apparently differ within closely related host-parasite system

The energetic grooming costs imposed by a parasitic mite (Spinturnix myoti) upon its bat host (Myotis myotis).

Parasites often exert severe negative effects upon their host's fitness. Natural selection has therefore prompted the evolution of anti-parasite mechanisms such as grooming. Grooming is efficient at reducing parasitic loads in both birds and mammals, but the energetic costs it entails have not been properly quantified. We measured both the energetic metabolism and behaviour of greater mouse-eared bats submitted to three different parasite loads (no, 20 and 40 mites) during whole daily cycles. Mites greatly affected their time and energy budgets. They caused increased grooming activity, reduced the overall time devoted to resting and provoked a dramatic shortening of resting bout duration. Correspondingly, the bats' overall metabolism (oxygen consumption) increased drastically with parasite intensity and, during the course of experiments, the bats lost more weight when infested with 40 rather than 20 or no parasites. The short-term energetic constraints induced by anti-parasite grooming are probably associated with long-term detrimental effects such as a decrease in survival and overall reproductive value

Studies on adsorption of propiconazole on modified carbons

International audienceThe adsorption capacity and kinetics of propiconazole in aqueous solution using untreated and treated activated carbons as adsorbents have been studied, providing new experimental data at different temperatures which were obtained using the bottle-point method. Untreated carbon was oxidized with HNO3, H2O2, NaOCl and NaOH to produce a series of samples with different surface chemical properties. The surface chemistry was characterized by the determination of the point of zero charge. It was found that the physical morphology of the sample is affected by the strength of the oxidizing agent and the operating conditions. The surface chemistry of the activated carbon plays a key role in pollutant adsorption performance. Results of sorption experiments showed that carbon modified with NaOH is the best material for the adsorption of propiconazole at pH 6.5. Sorption of propiconazole reached equilibrium in 120 min. The maximum adsorption onto untreated activated carbon was 101 mg/g. As expected, the adsorption increased with increasing temperature. Adsorption kinetics obeyed a second-order kinetic model

Patients’ Experiences, Expectations, Motivations, and Perspectives around Urinary Tract Infection Care in General Practice: A Qualitative Interview Study

While there are many alternatives to antibiotics for the symptomatic treatment of urinary tract infections (UTIs), their application in practice is limited. Among other things, general practitioners (GPs) often feel pressure from patients to prescribe antibiotics. To gain a better understanding of why this happens and where this pressure originates from, we investigated experiences, expectations, motivations, and perspectives of patients with UTIs in general practice. During this qualitative study we performed 14 semi-structured online interviews among female UTI patients in general practice. Interviews were based on a topic list derived from sensitising concepts. All the interviews were recorded, transcribed, and analysed using a constant comparative technique. Three main categories emerged from the data; (1) experienced versus unexperienced patients with UTI, (2) patient’s lack of knowledge, and (3) patients feeling understood. Inexperienced patients consult a general practitioner for both diagnosis and symptom relief, while experienced patients seem to consult specifically to obtain antibiotics. In addition, patients have a lack of knowledge with regard to the diagnosis, treatment, self-care, and cause of UTIs. Finally, patients’ satisfaction is increased by involving them more in the process of decision making, so they feel understood and taken seriously. Patients’ expectations in UTI management in general practice often arise during their first experience(s) and play a major role in subsequent episodes. In conclusion, preventing misconceptions is especially important in the inexperienced patient group, as this may prevent future overtreatment of UTIs. In addition, involving patients in the decision making process will lead to greater understanding of the GP’s treatment choices

Patients’ Experiences, Expectations, Motivations, and Perspectives around Urinary Tract Infection Care in General Practice: A Qualitative Interview Study

While there are many alternatives to antibiotics for the symptomatic treatment of urinary tract infections (UTIs), their application in practice is limited. Among other things, general practitioners (GPs) often feel pressure from patients to prescribe antibiotics. To gain a better understanding of why this happens and where this pressure originates from, we investigated experiences, expectations, motivations, and perspectives of patients with UTIs in general practice. During this qualitative study we performed 14 semi-structured online interviews among female UTI patients in general practice. Interviews were based on a topic list derived from sensitising concepts. All the interviews were recorded, transcribed, and analysed using a constant comparative technique. Three main categories emerged from the data; (1) experienced versus unexperienced patients with UTI, (2) patient’s lack of knowledge, and (3) patients feeling understood. Inexperienced patients consult a general practitioner for both diagnosis and symptom relief, while experienced patients seem to consult specifically to obtain antibiotics. In addition, patients have a lack of knowledge with regard to the diagnosis, treatment, self-care, and cause of UTIs. Finally, patients’ satisfaction is increased by involving them more in the process of decision making, so they feel understood and taken seriously. Patients’ expectations in UTI management in general practice often arise during their first experience(s) and play a major role in subsequent episodes. In conclusion, preventing misconceptions is especially important in the inexperienced patient group, as this may prevent future overtreatment of UTIs. In addition, involving patients in the decision making process will lead to greater understanding of the GP’s treatment choices

Differential species-specific ectoparasitic mite intensities in two intimately coexisting sibling bat species: resource-mediated host attractiveness or parasite specialization?

1. The mechanisms underlying host choice strategies by parasites remain poorly understood. We address two main questions: (i) do parasites prefer vulnerable or well-fed hosts, and (ii) to what extent is a parasite species specialized towards a given host species? 2. To answer these questions, we investigated, both in the field and in the lab, a host-parasite system comprising one ectoparasitic mite (Spinturnix myoti) and its major hosts, two sibling species of bats (Myotis myotis and M blythii), which coexist intimately in colonial nursery roosts. We exploited the close physical associations between host species in colonial roosts as well as naturally occurring annual variation in food abundance to investigate the relationships between parasite intensities and (i) host species and (ii) individual nutritional status. 3. Although horizontal transmission of parasites was facilitated by the intimate aggregation of bats within their colonial clusters, we found significant interspecific differences in degree of infestation throughout the 6 years of the study, with M. myotis always more heavily parasitized than M. blythii. This pattern was replicated in a laboratory experiment in which any species-specific resistance induced by exploitation of different trophic niches in nature was removed. 4. Within both host species, S. myoti showed a clear preference for individuals with higher nutritional status. In years with high resource abundance, both bat hosts harboured more parasites than in low-resource years, although the relative difference in parasite burden across species was maintained. This pattern of host choice was also replicated in the laboratory. When offered a choice, parasites always colonized better-fed individuals. 5. These results show first that host specialization in our study system occurred. Second, immediate parasite choice clearly operated towards the selection of hosts in good nutritional state

Il partito di massa

Il saggio affronta la lunzione del Pci in quanto partito di massa nella ricostruzione della democrazia e della nazione italiana, e il paradosso per cui una radicale contrapposizione col passato e la costruzione di una comunità internazionalista "immaginata" portano alla progressiva dissoluzione della fede nel partito che ne anima la vita almeno fino alla fine degli anni settanta. Si propone in conseguenza una periodizzazione del partito di massa diversa da quella del partito elettorale che invece emerge all'incirca dagli anni sessanta in poi e finisce per sostituire il primo.The essay suggests that in retrospective the construction of a mass party was the most important feature of the ICP history after 1944. The paradox of an international "imagined community" that helped relegitimizing a natiomal democracy can be explained by the important cultural and social functions of integration played by the mass party in the early phase of the Republic, until at least the Seventies. The article deals also with the outgrowth of an electoral party that contradicted the integrative mass party and suggests that the inability of the ICP leadership at keeping the two together should be investigated as one reason for the dissolution of the party after 1989

Article 8 MSFD Assessment Guidance

International audienc