966 resultados para Predatory mites


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Information about the population genetic structures of parasites is important for an understanding of parasite transmission pathways and ultimately the co-evolution with their hosts. If parasites cannot disperse independently of their hosts, a parasite's population structure will depend upon the host's spatial distribution. Geographical barriers affecting host dispersal can therefore lead to structured parasite populations. However, how the host's social system affects the genetic structure of parasite populations is largely unknown. We used mitochondrial DNA (mtDNA) to describe the spatio-temporal population structure of a contact-transmitted parasitic wing mite (Spinturnix bechsteini) and compared it to that of its social host, the Bechstein's bat (Myotis bechsteinii). We observed no genetic differentiation between mites living on different bats within a colony. This suggests that mites can move freely among bats of the same colony. As expected in case of restricted inter-colony dispersal, we observed a strong genetic differentiation of mites among demographically isolated bat colonies. In contrast, we found a strong genetic turnover between years when we investigated the temporal variation of mite haplotypes within colonies. This can be explained with mite dispersal occuring between colonies and bottlenecks of mite populations within colonies. The observed absence of isolation by distance could be the result from genetic drift and/or from mites dispersing even between remote bat colonies, whose members may meet at mating sites in autumn or in hibernacula in winter. Our data show that the population structure of this parasitic wing mite is influenced by its own demography and the peculiar social system of its bat host.

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Garlic mustard is a rapidly spreading, highly invasive non-native plant. It was introduced from Europe in mid-1800 for medicinal and herbal uses. Came to the United States without predatory beetles or other natural controls. Threatens to rob us of healthy, diverse native woodlands.

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Owl pellets contain a good skeletal record of the small mammals consumed, and correspond to the undigested portions of prey which are regurgitated. These pellets are easy to find at the roosting site of owls. As it has been demonstrated that amplifiable DNA can be isolated from ancient bone remains, the possibility of using owl pellets as a source of DNA for small mammal genetics studies via the polymerase chain reaction has been investigated. The main uncertainties when isolating DNA from such a material are firstly the possibility that the extracted DNA would be too degraded during the digestion in the stomach of the owl, and secondly that extensive cross-contaminations could occur among the different prey consumed. The results obtained clearly demonstrate that cross-contamination does not occur, and that mitochondrial and nuclear DNA can be amplified using skulls of small mammals found in owl pellets as a source of DNA. The relative efficiency of two methods of DNA extraction is estimated and discussed. Thus, owl pellets represent a non-invasive sampling technique which provides a valuable source of DNA for studying population genetics of small mammals.

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L’objectiu d’aquest treball és conèixer la percepció que tenen els adolescents usuaris dels centres oberts de la ciutat de Girona sobre la sexualitat, l’afectivitat, quins rols de gènere se’n deriven i quines creences els sustenten. El disseny del treball ha estat qualitatiu, observacional, grups de discussió. Pel que fa als subjectes i al mètode, la població seleccionada ha estat de 33 adolescents i joves d’edats compreses entre els 12 i els 22 anys, usuaris de quatre centres oberts de Girona: el centre obert de Taialà, el Centre Obert de Font de la Pólvora (Onyar), el Centre Obert de Santa Eugènia i el Centre Obert del Barri Vell. Es van dur a terme grups de discussió d’una hora de duració sense descans amb d’entre 6 i 8 persones a partir d’un guió format per diversos mites i frases en relació a diversos temes (El festeig, la virginitat, la curiositat pel cos i per la sexualitat, els anticonceptius i les principals fonts d’informació) sobre les que havien de dir si estaven d’acord o no i qui creien que les deia (si un noi o una noia). Sobre els resultats del treball cal dir que s’ha observat la persistència d’algunes creences del model del amor romàntic en relació al rols de gènere com la definició de la dona vinculada a papers de cura i prevenció, una dona que té accés a la sexualitat però segueix estan catalogada per la vivència d’aquesta essent una persona “respectable” o una “puta”, que pren un rol més actiu en la iniciativa però no el l’assertivitat en les relacions; i un home, més impulsiu i sexual. En relació als comportaments sexuals destacar l’embaràs no desitjat com la principal preocupació de les relacions i el desconeixement/confusió entre els mètodes anticonceptius i de barrera disponibles a la xarxa de salut. Apareix la pornografia com a model emergent de relacions sexuals i models de relació entre homes i dones, en contraposició a altres fonts de informació i consulta tradicionals com els amics que segueixen essent la més significativa, la família, els serveis socials i educatius, i Internet. Com a conclusió cal dir que queda palesa la necessitat de incorporar una perspectiva de gènere en la formació curricular dels joves i el fet de seguir replantejant les millors estratègies d’intervenció per una concepció integradora de la sexualitat

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Males of plants with separate sexes are often more prone to attack by herbivores than females. A common explanation for this pattern is that individuals with a greater male function suffer more from herbivory because they grow more quickly, drawing more heavily on resources for growth that might otherwise be allocated to defence. Here, we test this 'faster-sex' hypothesis in a species in which males in fact grow more slowly than hermaphrodites, the wind-pollinated annual herb Mercurialis annua. We expected greater herbivory in the faster-growing hermaphrodites. In contrast, we found that males, the slower sex, were significantly more heavily eaten by snails than hermaphrodites. Our results thus reject the faster-sex hypothesis and point to the importance of a trade-off between defence and reproduction rather than growth.

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The purpose of this article is two-fold. First, it provides an overview of the types of lending discrimination, discusses what laws apply to lending discrimination, and explains how to establish a prima facie case and pretext. This discussion will borrow concepts and case law from the areas of employment discrimination and the related issue of rental discrimination. Each of these areas share similar required elements as well as the need to establish pre-text. Second, this article provides an overview of predatory lending practices, applicable law, and potential remedies.

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The objective of this work was to assess the soil oribatid mite communities in four sites of the Upper Paraná Bosque Atlántico, in the Iguazú National Park, Argentina and in surrounding areas: bamboo forest, palm forest and two mixed forests. A comparison between each pair of sites, based on the presence-absence of oribatid species, was performed using Jaccard's index. This is the first systematic sampling of oribatid mites in this area. A total of 56 genera and 96 oribatid species were found, 25 and 49 of them, respectively, are new citation for Argentina. The highest similarity was found between mixed forests. Almost 68% and 34% of the genera were cited for similar biotopes in Brazil and Paraguay, respectively.

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In-lake management can be a critical need for water quality improvement for impaired recreation lakes. Biomanipulation practices to achieve the proper balance of predatory fish, zooplankton grazing of algae, and native aquatic vegetation can sometimes restore water clarity of turbid, nutrient enriched lakes. Lakewood leaders have a renovation plan for Lake Colchester, involving several common and three innovative practices. Lakewood is prepared to pay for proven practices, but seeks WIRB grant support to test innovations in collaboration with Iowa DNR biologists, and ISU limnologists, serving as advisors and monitors for the entire project.

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Identifying the factors that mediate covariation between an ornament and other phenotypic attributes is important to determine the signaling function of ornaments. Sign and magnitude of a covariation may vary across environments if the expression of the ornament or of its linked genes regulating correlated phenotypes is condition-dependent. I investigated in the barn owl Tyto alba whether sign and magnitude of covariation between body mass and two heritable melanin-based plumage ornaments change with food supply, along the reproductive cycle and from the morning to the evening. Using a dataset of 1,848 measurements of body mass in 336 breeding females, I found that females displaying large black spots were heavier than conspecifics with smaller spots in the afternoon (i.e., a long time after the last feeding) but not in the morning (i.e., a short time after the last feeding). This is consistent with the recently proposed hypothesis that eumelanin-based ornaments are associated with the ability to maintain energy balance between food intake and energy expenditure. Thus, covariation between melanin-based coloration and body mass can be detected only under specific conditions potentially explaining why it has been reported in only ten out of 28 vertebrate species. The proposition that ornamented individuals achieve a higher fitness than drab conspecifics only in specific environments should be tested for other ornaments.

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Defining the degree of host specificity in host-parasite studies can greatly inform cophylogenetic history. In a recent paper, Guiller and Deunff (2010) cast doubt on some points and conclusions drawn from a cophylogenetic study between European bats and Spinturnicid mites (Bruyndonckx et al., 2009a). Here we answer their criticisms and discuss the notion of specificity in Spinturnicid mites.

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SUMMARY IL-1R and TLRs are key players in innate immunity and inflammation. Tollip was identified as a component of IL-1RI, TLR2 and TLR4 signaling complexes that activate NF-κB and MAP kinase pathways. Tollip was previously shown as a negative regulator of NF-κB and MAP Kinase activation. We have characterized the role of Tollip in IL-R/TLRs induced signaling by the analysis of the Tollip deficient mice. We showed that NF-κB and MAPK (p38, JNK, or ERK1/2) signaling appeared normal in Tollip deficient cells following stimulation with IL-1β, lipopolysaccharide (LPS), and other TLR ligands. Also IL-1β and TLRs ligands induced activation of immune cells was indistinguishable from wild-type cells. Strikingly, in Tollip deficient mice the production of the inflammatory cytokines, IL-6 or TNF-α was significantly reduced relative to control mice after treatment with physiological doses of IL-1β or LPS, whereas no difference was observed at high doses of stimulation with LPS or in LPS induced septic shock. Therefore, Tollip could be critical for regulation of optimal responses to IL-1β and LPS, in addition to its role as negative regulator of the signaling. We also studied the role of Tollip as an endocytic adaptor for IL-1R endocytosis. We could show that Il-1R is ubiquitinated after IL-1β stimulation, and that Tollip's CUE domain binds IL-1RI in an ubiquitin-dependent manner. We followed IL-1R internalization and Tollip localization by confocal microscopy. Consistent with a role for Tollip in sorting of ubiquitinated IL-1RI, a significant amount of Tollip was also localized at the late endosomal compartment. We could show that Tollip is required for efficient lysosomal targeting of ubiquitinated IL-1R1, In the absence of Tollip or in Tollip deficient cells reconstituted with a Tollip mutant (defective in ubiquitin binding) IL-1RI accumulates in enlarged late endosomes. In addition, Tollip was shown to interact with, another endocytic adapter, Toml, and both interact with IL-1RI. In conclusion, we showed that Tollip is required for IL-1β and LPS signaling for cytokine production. In addition we showed and that Tollip has a role as an endocytic adapter, necessary for efficient trafficking and lysosomal degradation of IL-1RI. Resumé Le récepteur à l'interleukine-1 (IL-1R) et les récepteurs "Toll-like" (TLRs) sont des acteurs cruciaux de la réponse immunitaire innée et de l'inflammation. La proteine Tollip a été identifiée comme étant un élément des complexes de signalisation, induits par les récepteurs IL-1RI, TLR-2 et TLR-4, qui mènent à l'activation de la voie des MAP kinases et de NF-κB. Dans de précédentes études, il a été montré que Tollip pouvait inhiber ces deux voies de signalisation. Nous avons voulu caractériser plus précisément le rôle de Tollip dans l'activation des voies de signalisation mitées par IL-1R/TLRs en utilisant une lignée murine déficiente pour la protéine Tollip. Ainsi, en absence de Tollip, les cascades d'activation de NF-κB et MAPK (p38, JNK, or ERK1/2) ne semblent pas affectées après stimulation avec IL-1β, lipopolysaccharide (LPS) ou d' autres ligands des TLR. La réponse des cellules du système immunitaire induite par la stimulation avec IL-1β et les ligands des TLR est également comparable entre les souris sauvages et les souris deficientes pour Tollip. Par contre, dans cette lignée murine, la production de cytokines proinflammatoires IL-6 et TNFα induite par la stimulation à dose physiologique de IL-1β or LPS, est réduite. Cependant, lors de stimulation à plus hautes doses de LPS ou pendant un choc septique induit par de LPS, cette réduction n'est pas observée. Ces résultats montrent que Tollip pourrait avoir un rôle déterminant dans l'activation optimale en réponse à l' IL-1β et au LPS qui s'ajoute à sa fonction inhibitrice des mêmes voies de signalisation. Nous avons aussi étudié le rôle de Tollip comme molécule adaptatatrice du mécanisme endocytique d'internalisation de l' IL-1RI. Ainsi, l' IL-1R est ubiquitiné après stimulation par l' IL-1β , permettant à Tollip de se lier au récepteur. Cette interaction est réalisée entre le domaine CUE de Tollip et l'IL-1R via l'ubiquitine. L'internalisation et la localisation intracellulaire de l'IL-1RI et de Tollip ont été observés par microscopie confocale. En accord avec le rôle de Tollip dans le triage et la recirculation des IL-1R ubiquitiné, une quantité importante de Tollip été détectée dans l' endosome tardif. Nous avons pu démontrer que Tollip était nécessaire pour diriger efficacement ubiquitiné vers les lysosomes. Dans des cellules déficientes pour Tollip, ou reconstituées avec un mutant de Tollip (MF/AA) incapable de lier l'ubiquitine, IL-1RI s'accumule dans des vesicules anormales de l'endosome tardif. Dans ce travail, nous avons pu confirmer et préciser la fonction de la protéine Tollip dans l' activation de la production de cytokines induites par l' IL-1p and le LPS lors de l'inflammation et découvrir son rôle d'adaptateur dans l' internalisation et l'endocytose de l' IL-1RI.

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The objective of my thesis is to assess mechanisms of ecological community control in macroalgal communities in the Baltic Sea. In the top-down model, predatory fish feed on invertebrate mesograzers, releasing algae partly from grazing pressure. Such a reciprocal relationship is called trophic cascade. In the bottom-up model, nutrients increase biomass in the food chain. The nutrients are first assimilated by algae and, via food chain, increase also abundance of grazers and predators. Previous studies on oceanic shores have described these two regulative mechanisms in the grazer - alga link, but how they interact in the trophic cascades from fish to algae is still inadequately known. Because the top-down and bottom-up mechanisms are predicted to depend on environmental disturbances, such as wave stress and light, I have studied these models at two distinct water depths. There are five factorial field experiments behind the thesis, which were all conducted in the Finnish Archipelago Sea. In all the experiments, I studied macroalgal colonization - either density, filament length or biomass - on submerged colonization substrates. By excluding predatory fish and mesograzers from the algal communities, the studies compared the strength of the top-down control to natural algal communities. A part of the experimental units were, in addition, exposed to enriched nitrogen and phosphorus concentrations, which enabled testing of bottom-up control. These two models of community control were further investigated in shallow (<1 m) and deep (ca. 3 m) water. Moreover, the control mechanisms were also expected to depend on grazer species. Therefore different grazer species were enclosed into experimental units and their impacts on macroalgal communities were followed specifically. The community control in the Baltic rocky shores was found to follow theoretical predictions, which have not been confirmed by field studies before. Predatory fish limited grazing impact, which was seen as denser algal communities and longer algal filaments. Nutrient enrichment increased density and filament length of annual algae and, thus, changed the species composition of the algal community. The perennial alga Fucus vesiculosusA and the red alga Ceramium tenuicorne suffered from the increased nutrient availabilities. The enriched nutrient conditions led to denser grazer fauna, thereby causing strong top-down control over both the annual and perennial macroalgae. The strength of the top-down control seemed to depend on the density and diversity of grazers and predators as well as on the species composition of macroalgal assemblages. The nutrient enrichment led to, however, weaker limiting impact of predatory fish on grazer fauna, because fish stocks did not respond as quickly to enhanced resources in the environment as the invertebrate fauna. According to environmental stress model, environmental disturbances weaken the top-down control. For example, on a wave-exposed shore, wave stress causes more stress to animals close to the surface than deeper on the shore. Mesograzers were efficient consumers at both the depths, while predation by fish was weaker in shallow water. Thus, the results supported the environmental stress model, which predicts that environmental disturbance affects stronger the higher a species is in the food chain. This thesis assessed the mechanisms of community control in three-level food chains and did not take into account higher predators. Such predators in the Baltic Sea are, for example, cormorant, seals, white-tailed sea eagle, cod and salmon. All these predatory species were recently or are currently under intensive fishing, hunting and persecution, and their stocks have only recently increased in the region. Therefore, it is possible that future densities of top predators may yet alter the strengths of the controlling mechanisms in the Baltic littoral zone.

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The Ebro Delta holds a large seabird community, including a common tern (Sterna hirundo) local population of 3,085 pairs in 2000 which breeds scattered in several colonies. At El Canalot colony, 1,178 (1999) and 1,156 pairs (2000) of this species bred distributed in 32 and 38 sub-colonies respectively. These sub-colonies varied in size from 1 to 223 pairs and were placed near the main breeding colonies of yellow-legged gulls (Larus cachinnans) and Audouin´s gulls (L. audouinii), which are potential egg-predators of terns. We studied egg predation during 1999 (6 sub-colonies) and 2000 (27 sub-colonies). Overall, we found that 10.6% of the nests in 1999 and 16.7% in 2000 suffered partial or total egg predation, being total in 81.1% of the predatory events. Predation was significantly higher in small sub-colonies (< 11 pairs): 49.4% in 1999 and 75.5% in 2000. Only attacks from yellow-legged gulls were observed, and defence behaviour of terns was significantly more frequent against this gull species (40.5 hours of observation), suggesting that in most cases the egg predation recorded was due to this species. Probability of egg predation was significantly and negatively correlated with distance to the nearest yellow-legged gull sub-colony, although this relationship was no more significant after adjustment for sub-colony size. On the other hand, distance to the nearest Audouin´s gull sub-colony did not show any effect. Our results suggest that the impact of large gulls (at least yellow-legged gulls) upon smaller seabirds breeding in the area might be important, especially when they are breeding in small sub-colonies. Further studies are needed to analyse the general impact of large gulls upon the breeding populations of other colonial bird species in the area.

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Transposable elements (TEs) and other repetitive DNA can accumulate in the absence of recombination, a process contributing to the degeneration of Y-chromosomes and other nonrecombining genome portions. A similar accumulation of repetitive DNA is expected for asexually reproducing species, given their entire genome is effectively nonrecombining. We tested this expectation by comparing the whole-genome TE loads of five asexual arthropod lineages and their sexual relatives, including asexual and sexual lineages of crustaceans (Daphnia water fleas), insects (Leptopilina wasps), and mites (Oribatida). Surprisingly, there was no evidence for increased TE load in genomes of asexual as compared to sexual lineages, neither for all classes of repetitive elements combined nor for specific TE families. Our study therefore suggests that nonrecombining genomes do not accumulate TEs like nonrecombining genomic regions of sexual lineages. Even if a slight but undetected increase of TEs were caused by asexual reproduction, it appears to be negligible compared to variance between species caused by processes unrelated to reproductive mode. It remains to be determined if molecular mechanisms underlying genome regulation in asexuals hamper TE activity. Alternatively, the differences in TE dynamics between nonrecombining genomes in asexual lineages versus nonrecombining genome portions in sexual species might stem from selection for benign TEs in asexual lineages because of the lack of genetic conflict between TEs and their hosts and/or because asexual lineages may only arise from sexual ancestors with particularly low TE loads.

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Les últimes dades de l'estudi europeu del 2014, sobre la violència de parella indiquen que gairebé 62 milions de dones europees, havien sofert actes de violència de gènere, entre els quals es destaca els relacionats amb la violència de parella (VP). Els maltractaments constitueixen un problema molt greu que genera al nostre país cada vegada més alarma social i més actuacions legals i professionals per fer-li front. El sistema de salut és, amb freqüència, el primer lloc al que les víctimes de violència domèstica acudeixen a la recerca d'assessorament i ajuda, sent aquest el motiu pel qual els professionals de la salut tenen un paper central per a la seva assistència. Aquests formen part implicada en el sistema de detecció, atenció i actuació. Per això, els plans d'estudi de Grau d'Infermeria recullen en el BOE la formació en VP des de l’àmbit universitari. L’objectiu del nostre estudi consisteix en la identificació de la percepció i dels coneixements en relació a la violència de parella dels estudiants del Grau d’Infermeria de la Universitat de Girona durant el curs acadèmic 2012-2013. Per a dur-lo a terme es va realitzar un anàlisi quantitatiu dels resultats a través de l’administració d’una enquesta sobre sis aspectes de la VP, l’enquesta incloïa el perfil demogràfic (sexe, edat i anys d'estudi) dels estudiants i les declaracions relatives a les seves percepcions i coneixements sobre la VP: causes d'abús; la identificació de les dones objecte de VP i del seus autors; creences de les infermeres; funcions perceptibles; i la preparació educativa. Els estudiants del Grau d’Infermeria mostren tenir un bon coneixement sobre les causes del abús en VP, així com una formació adequada. També cal destacar que un 54,42% dels alumnes enquestats es veuen capacitats per afrontar un cas de VP com a infermer/a. S’observa una millora de la formació educativa en el transcurs acadèmic. En 1r curs un 40,09% té una bona formació, aquest valor augmenta fins a un 56,58% a tercer curs, baixant lleugerament fins un 44,27% a 4rt curs. Els resultats obtinguts són semblats a estudis de mostres similars en estudiants d'infermeria de Memphis (EUA) i de la University of Southern Queensland (Austràlia) quant a coneixements i percepció sobre la VP. Encara que els resultats mostren un coneixement i una percepció sobre la VP adequada, destaquem que això no succeeix en gairebé un 40% dels enquestats. La introducció de matèries específiques sobre igualtat i sobre violència contra la dona en els plans d’estudis, pot esdevenir una mesura preventiva per revisar i corregir possibles mites i creences en VP. Per tant, és necessari millorar la formació del currículum en estudiants d'infermeria per la importància d'aquest greu problema de salut pública, donant major èmfasis en la satisfacció de les necessitats emocionals i en la comprensió dels diferents enfocaments en VP, especialment en mesures de prevenció i educació