941 resultados para cercarial emergence


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We present the first study comparing epitheliocystis in a wild and farmed salmonid in Europe. Sampling three tributaries to the Lake Geneva, including one from headwaters to river mouth, revealed an unequal distribution of epitheliocystis in brown trout (Salmo trutta). When evaluated histologically and comparing sites grouped as wild versus farm, the probability of finding infected trout is higher on farms. In contrast, the infection intensities, as estimated by the number of cysts per gill arch, were higher on average and showed maximum values in the wild trout. Sequence analysis showed the most common epitheliocystis agents were Candidatus Piscichlamydia salmonis, all clustering into a single clade, whereas Candidatus Clavichlamydia salmonicola sequences cluster in two closely related sub-species, of which one was mostly found in farmed fish and the other exclusively in wild brown trout, indicating that farms are unlikely to be the source of infections in wild trout. A detailed morphological analysis of cysts using transmission electron microscopy revealed unique features illustrating the wide divergence existing between Ca. P. salmonis and Ca. C. salmonicola within the phylum Chlamydiae

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Enzootic pneumonia (EP) caused by Mycoplasma hyopneumoniae has a significant economic impact on domestic pig production. A control program carried out from 1999 to 2003 successfully reduced disease occurrence in domestic pigs in Switzerland, but recurrent outbreaks suggested a potential role of free-ranging wild boar (Sus scrofa) as a source of re-infection. Since little is known on the epidemiology of EP in wild boar populations, our aims were: (1) to estimate the prevalence of M. hyopneumoniae infections in wild boar in Switzerland; (2) to identify risk factors for infection in wild boar; and (3) to assess whether infection in wild boar is associated with the same gross and microscopic lesions typical of EP in domestic pigs. Nasal swabs, bronchial swabs and lung samples were collected from 978 wild boar from five study areas in Switzerland between October 2011 and May 2013. Swabs were analyzed by qualitative real time PCR and a histopathological study was conducted on lung tissues. Risk factor analysis was performed using multivariable logistic regression modeling. Overall prevalence in nasal swabs was 26.2% (95% CI 23.3-29.3%) but significant geographical differences were observed. Wild boar density, occurrence of EP outbreaks in domestic pigs and young age were identified as risk factors for infection. There was a significant association between infection and lesions consistent with EP in domestic pigs. We have concluded that M. hyopneumoniae is widespread in the Swiss wild boar population, that the same risk factors for infection of domestic pigs also act as risk factors for infection of wild boar, and that infected wild boar develop lesions similar to those found in domestic pigs. However, based on our data and the outbreak pattern in domestic pigs, we propose that spillover from domestic pigs to wild boar is more likely than transmission from wild boar to pigs.

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BACKGROUND  Drug resistance is a major barrier to successful antiretroviral treatment (ART). Therefore, it is important to monitor time trends at a population level. METHODS  We included 11,084 ART-experienced patients from the Swiss HIV Cohort Study (SHCS) between 1999 and 2013. The SHCS is highly representative and includes 72% of patients receiving ART in Switzerland. Drug resistance was defined as the presence of at least one major mutation in a genotypic resistance test. To estimate the prevalence of drug resistance, data for patients with no resistance test was imputed based on patient's risk of harboring drug resistant viruses. RESULTS  The emergence of new drug resistance mutations declined dramatically from 401 to 23 patients between 1999 and 2013. The upper estimated prevalence limit of drug resistance among ART-experienced patients decreased from 57.0% in 1999 to 37.1% in 2013. The prevalence of three-class resistance decreased from 9.0% to 4.4% and was always <0.4% for patients who initiated ART after 2006. Most patients actively participating in the SHCS in 2013 with drug resistant viruses initiated ART before 1999 (59.8%). Nevertheless, in 2013, 94.5% of patients who initiated ART before 1999 had good remaining treatment options based on Stanford algorithm. CONCLUSION  HIV-1 drug resistance among ART-experienced patients in Switzerland is a well-controlled relic from the pre-combination ART era. Emergence of drug resistance can be virtually stopped with new potent therapies and close monitoring.

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In this paper I will reflect on the emergence of the distinct figure of the child asylum seeker which has entered public and political debates in Switzerland within the last 2 years. It is a figure that is identified through certain attributes such as youth, trauma, lostness or need for protection, and it is a figure that is imbued with certain rights (namely children’s rights). While this has helped young people to receive special treatment, the question arises what the repercussions are for those who do not fit within these categories. What, for example, happens, when different notions of youth, childhood and adolescence clash and disrupt ideals of innocence and childhood? And given that negative public discourses are largely focussed on the apparent danger and uncontrollability of male, single asylum seekers, what happens when categories mix and mingle? In this paper I will shed light on the interplay of institutional expectations of what constitutes a 'proper' child refugee and the ways young people themselves play with, test and contest these norms.

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Numerous theories have been advanced in the effort to explain how a given policy issue manages to take root in the public sphere and subsequently move forward on the public legislative agenda—or not. This study examined how the social determinants of health (SDOH) came to be part of the legislative policy agenda in Britain from 1980 to 2003. ^ The specific objectives of the research were: (1) to conduct a sociopolitical analysis grounded in alternative agenda-setting theories to identify the factors responsible for moving the social determinants health perspective onto the British policy agenda; and (2) to determine which of the theories and related dimensions best accounted for the emergence of this perspective. ^ A triangulated content and context analysis of British news articles, historical accounts, and research commentaries of the SDOH movement was conducted guided by relevant agenda-setting theories set within a social movement framework to chronicle the emergence of the SDOH as a significant policy issue in Britain. ^ The most influential social movement and agenda setting elements in the emergence of the SDOH in Britain were issue generation tactics, framing efforts, mobilizing structures, and political opportunities grounded in social movement and agenda setting theories. Policy content or the details of the policy had comparatively little impact on the successful emergence of the SDOH. Despite resistance by the government, from 1980 to 1996 interest groups created a political understanding of the SDOH utilizing a framing package encompassing notions of inequality, fairness, and justice. This frame transmitted a powerful idea connected to a core set of British values and beliefs. After 1996, a shift in political opportunities cemented the institutional arrangements needed to sustain an environment conducive to the development and implementation of SDOH policies and programs. ^ This research demonstrates that the U.S. emergence of the SDOH on the policy agenda will depend upon: (1) U.S. ideals and values regarding poverty, inequality, race, health, and health care that will determine issue framing; (2) political opportunities that will emerge—or not—to advance the SDOH policy agenda; and (3) the mobilizing structures that support or oppose the issue. ^

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Background. Health care associated catheter related blood stream infections (CRBSI) represent a significant public health concern in the United States. Several studies have suggested that precautions such as maximum sterile barrier and use of antimicrobial catheters are efficacious at reducing CRBSI, but there is concern within the medical community that the prolonged use of antimicrobial catheters may be associated with increased bacterial resistance. Clinical studies have been done showing no association and a significant decrease in microbial resistance with prolonged minocycline/rifampin (M/R) catheter use. One explanation is the emergence of community acquired methicillin resistant Staphylococcus aureus (MRSA), which is more susceptible to antibiotics, as a cause of CRBSI.^ Methods. Data from 323 MRSA isolates cultured from cancer patients at The University of Texas MD Anderson Cancer center from 1997-2007 displaying MRSA infection were analyzed to determine whether there is a relationship between resistance to minocycline and rifampin and prolonged wide spread use of minocycline (M/R) catheters. Analysis was also conducted to determine whether there was a significant change in the prevalence community acquired MRSA (CA-MRSA) during this time period and if this emergence act as a confounder masquerading the true relationship between microbial resistance and prolonged M/R catheter use.^ Results. Our study showed that the significant (p=0.008) change in strain type over time is a confounding variable; the adjusted model showed a significant protective effect (OR 0.000281, 95% CI 1.4x10 -4-5.5x10-4) in the relationship between MRSA resistance to minocycline and prolonged M/R catheter use. The relationship between resistance to rifampin and prolonged M/R catheter use was not significant.^ Conclusion. The emergence of CA-MRSA is a confounder and in the relationship between resistance to minocycline and rifampin and prolonged M/R catheter use. However, despite the adjustment for the more susceptible CA-MRSA the widespread use of M/R catheters does not promote microbial resistance. ^

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In deserts, seedling emergence occurs only after precipitation threshold has been exceeded, however, the presence of trees modifies microenvironmental conditions that might affect the effectiveness of a water pulse. In the Monte desert, Prosopis flexuosa trees generate different micro-environmental conditions that might influence grass seedlings establishment. The objective of this work was: a) to know the effective minimum water input event that triggers the emergence of native perennial grass seedlings; b) to relate this fact with the effect of the shade of P. flexuosa canopy and the seasonal temperatures. Three important forage species of the Monte were studied: Pappophorum caespitosum and Trichloris crinita, with C4, and Jarava ichu, with C3 metabolism. Each season, seeds of these species were sown in pots placed at two light conditions: shade (similar to P. flexuosa cover) and open area, and with seven irrigation treatments (0, 10, 20, 30, 40, 2*10 and 3*10 mm). J. ichu did not emerge in any of the treatments. Significant seedling emergence was registered for P. caespitosum and T. crinita in shade conditions with 40 mm irrigation treatment in summer. Since 40 mm precipitation events are infrequent in the Monte, seedling emergence for these species would be restricted to exceptional rainy years. The facilitating effect of P. flexuosa shade would be important during the hot season.

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Was the spread of agropastoralism from the Fertile Crescent throughout Europe influenced by rapid climatic shifts? We here generate idealized climate events using palaeoclimate records. In a mathematical model of regional sociocultural development, these events disturb the subsistence base of simulated forager and farmer societies. We evaluate the regional simulated transition timings and durations against a published large set of radiocarbon dates for western Eurasia; the model is able to realistically hindcast much of the inhomogeneous space-time evolution of regional Neolithic transitions. Our study shows that the inclusion of climate events improves the simulation of typical lags between cultural complexes, but that the overall difference to a model without climate events is not significant. Climate events may not have been as important for early sociocultural dynamics as endogenous factors.

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In the neighbourhood of Oobloyah Bay various phenomena ean be eneountered whieh point to a ularge-seale uplift of shorelines, i.e. to an emergence of 200 m. Delta terraces, deltaic fan terraces and glacio-marine sands are regarded by the author as being the most reliable evidence of this. The marine limit documented by glacio-marine sand is to be found at ~170 m a.s.l. Hints of ancient shorelines located at a higher level exist only in the shape of badly preserved raised beaches. They were classified as less reliable records of past sea-levels, due to the lack of marine fossils and/or drift wood, and furthermore because those forms had been strongly influenced by periglacial processes. Deltaic deposits are of more importance in this context. The glacio-marine deltaic sands of several terrace levels contain terrestrial plant remnants which delivered C14dates. Using these dates und the relative elevations of terraces the emergenee of the area investigated could be recorded. This occured in a series of phases (and steps) which were summarized into two periods: an early period of emergenee which took place from at least 25 300 years B.P. to later than 17 340 years B.P. and a later one from at least 12 870 years B.P. up to the present day. The emergence seems to represent a discontinuous but regular sequence of relative sea level movements without intermittent submergence. Since the deltaic fans of the early emergence period were accumulated by sediments through glacio-fluvial channels of an adjacent glacier body the appropriate location of this glacial stage for one of the glaciers delivering meltwater (Nukapingwa Glacier) could be reconstructed. This stage of the glacier appears to belong to a retreating phase of the Mid-Wisconsin (?). The later period of emergence resulted in six rather glacio-marine delta terrace generations at the mouths of the main rivers with glaciofluvial regimen debouching into the Oobloyah Bay. A connection of this emergence with the glacial history of the field area is discussed. If one may rely on the age determinations of land derived plant fossils and their application for the climatic history of the area investigated, it must be concluded that the Heidelberg Valley, to a large extent, was alreaely deglaciated 25 000 years ago. The existence of a "Cockburn"-Phase in the sense of a major readvanee in Late Wisconsin times appears to be doubtful, or has been developed rather weakly.

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Late Cenozoic benthic foraminiferal faunas from the Caribbean Deep Sea Drilling Project (DSDP) Site 502 (3052 m) and East Pacific DSDP Site 503 (3572 m) were analyzed to interpret bottom-water masses and paleoceanographic changes occurring as the Isthmus of Panama emerged. Major changes during the past 7 Myr occur at 6.7-6.2, 3.4, 2.0, and 1.1 Ma in the Caribbean and 6.7-6.4, 4.0-3.2, 2.1, 1.4, and 0.7 Ma in the Pacific. Prior to 6.7 Ma, benthic foraminiferal faunas at both sites indicate the presence of Antarctic Bottom Water (AABW). After 6.7 Ma benthic foraminiferal faunas indicate a shift to warmer water masses: North Atlantic Deep Water (NADW) in the Caribbean and Pacific Deep Water (PDW) in the Pacific. Flow of NADW may have continued across the rising sill between the Caribbean and Pacific until 5.6 Ma when the Pacific benthic foraminiferal faunas suggest a decrease in bottom-water temperatures. After 5.6 Ma deep-water to intermediate-water flow across the sill appears to have stopped as the bottom-water masses on either side of the sill diverge. The second change recorded by benthic foraminiferal faunas occurs at 3.4 Ma in the Caribbean and 4.0-3.2 Ma in the Pacific. At this time the Caribbean is flooded with cold AABW, which is either gradually warmed or is replaced by Glacial Bottom Water (GBW) at 2.0 Ma and by NADW at 1.1 Ma. These changes are related to global climatic events and to the depth of the sill between the Caribbean and Atlantic rather than the rising Isthmus of Panama. Benthic foraminiferal faunas at East Pacific Site 503 indicate a gradual change from cold PDW to warmer PDW between 4.0 and 3.2 Ma. The PDW is replaced by the warmer, poorly oxygenated PIW at 2.1 Ma. Although the PDW affects the faunas during colder intervals between 1.4 and 0.7 Ma, the PIW remains the principal bottom-water mass in the Guatemala Basin of the East Pacific.

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Starting from almost null in the late 1990s, China's mobile phone handset industry has grown to account for more than 40 percent of the current world production. While export growth has been overwhelmingly led by multi-national corporations (MNCs), increasingly fierce competition in the domestic market ignited by the advent of local handset makers has induced unique industrial evolution: (1) outgrowth of independent design houses specialized in handset development and (2) emergence of IC fabless ventures that design core ICs for handsets. In the background of this evolutionary industrial growth there are factors such as, the scale and increasing diversity of China's domestic market that advantages local firms vis-a-vis MNCs; modularization of handset and semiconductor technologies; policy interventions that supports local startups. The emergence and evolution of China's handset industry is likely to have international implications as the growth of the global demand for low-cost and multi-function mobile phone handsets is expected to accelerate. Thus, our case suggests that the conventional view of latecomer industrialization and upgrading that emphasizes the key role of international production networks organized by MNCs needs to be modified in order to accommodate China's rise into perspective.

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Before rural local government units were established in Thailand, reform debates within the country faced a crucial issue: Candidates at the rural sub-district levels might adopt electioneering methods such as vote buying and the patronage system of the local political and economic elite, the methods that had been used in the national elections. In fact, the results of the 2006 survey in this paper, which followed the introduction of direct elections in rural local government units in 2003, contrast with the result anticipated during the debates on political reform. The preliminary data of the survey shows that the decentralization process and the introduction of the direct election system in the rural areas had some effect in changing the selection process of the local elite in Thailand.

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Global G.A.P. is a one of the most influential private standards in the area of food safety and sustainability. With increasing impacts of Global G.A.P., many Asian countries have introduced the country versions of GAPs; China GAP, Japan GAP, Viet GAP, Thai GAP and ASEAN GAP. Each has been influenced by Global G.A.P. but ways of implementation, implementation bodies as well as focus differ from each other. This paper examines the development and motivation behind how the Asian GAPs have been introduced both from current situation and from historical perspectives. Then we compare current situation of different Asian GAPs.

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The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species.