995 resultados para Integration testing
Resumo:
Finding out whether Plasmodium spp. are coevolving with their vertebrate hosts is of both theoretical and applied interest and can influence our understanding of the effects and dynamics of malaria infection. In this study, we tested for local adaptation as a signature of coevolution between malaria blood parasites, Plasmodium spp. and its host, the great tit, Parus major. We conducted a reciprocal transplant experiment of birds in the field, where we exposed birds from two populations to Plasmodium parasites. This experimental set-up also provided a unique opportunity to study the natural history of malaria infection in the wild and to assess the effects of primary malaria infection on juvenile birds. We present three main findings: i) there was no support for local adaptation; ii) there was a male-biased infection rate; iii) infection occurred towards the end of the summer and differed between sites. There were also site-specific effects of malaria infection on the hosts. Taken together, we present one of the few experimental studies of parasite-host local adaptation in a natural malaria system, and our results shed light on the effects of avian malaria infection in the wild.
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A major problem in developmental neurotoxicity (DNT) risk assessment is the lack of toxicological hazard information for most compounds. Therefore, new approaches are being considered to provide adequate experimental data that allow regulatory decisions. This process requires a matching of regulatory needs on the one hand and the opportunities provided by new test systems and methods on the other hand. Alignment of academically and industrially driven assay development with regulatory needs in the field of DNT is a core mission of the International STakeholder NETwork (ISTNET) in DNT testing. The first meeting of ISTNET was held in Zurich on 23-24 January 2014 in order to explore the concept of adverse outcome pathway (AOP) to practical DNT testing. AOPs were considered promising tools to promote test systems development according to regulatory needs. Moreover, the AOP concept was identified as an important guiding principle to assemble predictive integrated testing strategies (ITSs) for DNT. The recommendations on a road map towards AOP-based DNT testing is considered a stepwise approach, operating initially with incomplete AOPs for compound grouping, and focussing on key events of neurodevelopment. Next steps to be considered in follow-up activities are the use of case studies to further apply the AOP concept in regulatory DNT testing, making use of AOP intersections (common key events) for economic development of screening assays, and addressing the transition from qualitative descriptions to quantitative network modelling.
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Adult neurogenesis is regulated by the neurogenic niche, through mechanisms that remain poorly defined. Here, we investigated whether niche-constituting astrocytes influence the maturation of adult-born hippocampal neurons using two independent transgenic approaches to block vesicular release from astrocytes. In these models, adult-born neurons but not mature neurons showed reduced glutamatergic synaptic input and dendritic spine density that was accompanied with lower functional integration and cell survival. By taking advantage of the mosaic expression of transgenes in astrocytes, we found that spine density was reduced exclusively in segments intersecting blocked astrocytes, revealing an extrinsic, local control of spine formation. Defects in NMDA receptor (NMDAR)-mediated synaptic transmission and dendrite maturation were partially restored by exogenous D-serine, whose extracellular level was decreased in transgenic models. Together, these results reveal a critical role for adult astrocytes in local dendritic spine maturation, which is necessary for the NMDAR-dependent functional integration of newborn neurons.
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Different types of aerosolization and deagglomeration testing systems exist for studying the properties of nanomaterial powders and their aerosols. However, results are dependent on the specific methods used. In order to have well-characterized aerosols, we require a better understanding of how system parameters and testing conditions influence the properties of the aerosols generated. In the present study, four experimental setups delivering different aerosolization energies were used to test the resultant aerosols of two distinct nanomaterials (hydrophobic and hydrophilic TiO2). The reproducibility of results within each system was good. However, the number concentrations and size distributions of the aerosols created varied across the four systems; for number concentrations, e.g., from 10(3) to 10(6) #/cm(3). Moreover, distinct differences were also observed between the two materials with different surface coatings. The article discusses how system characteristics and other pertinent conditions modify the test results. We propose using air velocity as a suitable proxy for estimating energy input levels in aerosolization systems. The information derived from this work will be especially useful for establishing standard operating procedures for testing nanopowders, as well as for estimating their release rates under different energy input conditions, which is relevant for occupational exposure.
Resumo:
Many people regard the concept of hypothesis testing as fundamental to inferential statistics. Various schools of thought, in particular frequentist and Bayesian, have promoted radically different solutions for taking a decision about the plausibility of competing hypotheses. Comprehensive philosophical comparisons about their advantages and drawbacks are widely available and continue to span over large debates in the literature. More recently, controversial discussion was initiated by an editorial decision of a scientific journal [1] to refuse any paper submitted for publication containing null hypothesis testing procedures. Since the large majority of papers published in forensic journals propose the evaluation of statistical evidence based on the so called p-values, it is of interest to expose the discussion of this journal's decision within the forensic science community. This paper aims to provide forensic science researchers with a primer on the main concepts and their implications for making informed methodological choices.
Resumo:
Invasive mold infections are life-threatening diseases for which appropriate antifungal therapy is crucial. Their epidemiology is evolving, with the emergence of triazole-resistant Aspergillus spp. and multidrug-resistant non-Aspergillus molds. Despite the lack of interpretive criteria, antifungal susceptibility testing of molds may be useful in guiding antifungal therapy. The standard broth microdilution method (BMD) is demanding and requires expertise. We assessed the performance of a commercialized gradient diffusion method (Etest method) as an alternative to BMD. The MICs or minimal effective concentrations (MECs) of amphotericin B, voriconazole, posaconazole, caspofungin, and micafungin were assessed for 290 clinical isolates of the most representative pathogenic molds (154 Aspergillus and 136 non-Aspergillus isolates) with the BMD and Etest methods. Essential agreements (EAs) within ±2 dilutions of ≥90% between the two methods were considered acceptable. EAs for amphotericin B and voriconazole were >90% for most potentially susceptible species. For posaconazole, the correlation was acceptable for Mucoromycotina but Etest MIC values were consistently lower for Aspergillus spp. (EAs of <90%). Excellent EAs were found for echinocandins with highly susceptible (MECs of <0.015 μg/ml) or intrinsically resistant (MECs of >16 μg/ml) strains. However, MEC determinations lacked consistency between methods for strains exhibiting mid-range MECs for echinocandins. We concluded that the Etest method is an appropriate alternative to BMD for antifungal susceptibility testing of molds under specific circumstances, including testing with amphotericin B or triazoles for non-Aspergillus molds (Mucoromycotina and Fusarium spp.). Additional study of molecularly characterized triazole-resistant Aspergillus isolates is required to confirm the ability of the Etest method to detect voriconazole and posaconazole resistance among Aspergillus spp.
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Tampere University of Technology is undergoing a degree reform that started in 2013. One of the major changes in the reform was the integration of compulsory Finnish, Swedish and English language courses to substance courses at the bachelor level. The integration of content and language courses aims at higher quality language learning, more fluency in studies, and increased motivation toward language studies. In addition, integration is an opportunity to optimize the use of resources and to offer courses that are more tailored to the students' field of study and to the skills needed in working life. The reform also aims to increase and develop co-operation between different departments at the university and to develop scientific follow up. This paper gives an overview of the integration process conducted at TUT and gives examples of adjunct CLIL implementations in three different languages.
Resumo:
The adult hippocampus generates functional dentate granule cells (GCs) that release glutamate onto target cells in the hilus and cornus ammonis (CA)3 region, and receive glutamatergic and γ-aminobutyric acid (GABA)ergic inputs that tightly control their spiking activity. The slow and sequential development of their excitatory and inhibitory inputs makes them particularly relevant for information processing. Although they are still immature, new neurons are recruited by afferent activity and display increased excitability, enhanced activity-dependent plasticity of their input and output connections, and a high rate of synaptogenesis. Once fully mature, new GCs show all the hallmarks of neurons generated during development. In this review, we focus on how developing neurons remodel the adult dentate gyrus and discuss key aspects that illustrate the potential of neurogenesis as a mechanism for circuit plasticity and function.
Resumo:
Chromosome 22q11.2 deletion syndrome (22q11DS) is a genetic disease known to lead to cerebral structural alterations, which we study using the framework of the macroscopic white-matter connectome. We create weighted connectomes of 44 patients with 22q11DS and 44 healthy controls using diffusion tensor magnetic resonance imaging, and perform a weighted graph theoretical analysis. After confirming global network integration deficits in 22q11DS (previously identified using binary connectomes), we identify the spatial distribution of regions responsible for global deficits. Next, we further characterize the dysconnectivity of the deficient regions in terms of sub-network properties, and investigate their relevance with respect to clinical profiles. We define the subset of regions with decreased nodal integration (evaluated using the closeness centrality measure) as the affected core (A-core) of the 22q11DS structural connectome. A-core regions are broadly bilaterally symmetric and consist of numerous network hubs - chiefly parietal and frontal cortical, as well as subcortical regions. Using a simulated lesion approach, we demonstrate that these core regions and their connections are particularly important to efficient network communication. Moreover, these regions are generally densely connected, but less so in 22q11DS. These specific disturbances are associated to a rerouting of shortest network paths that circumvent the A-core in 22q11DS, "de-centralizing" the network. Finally, the efficiency and mean connectivity strength of an orbito-frontal/cingulate circuit, included in the affected regions, correlate negatively with the extent of negative symptoms in 22q11DS patients, revealing the clinical relevance of present findings. The identified A-core overlaps numerous regions previously identified as affected in 22q11DS as well as in schizophrenia, which approximately 30-40% of 22q11DS patients develop.
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We empirically applied the GrooFiWorld agent-based model (Puga-González et al. 2009) in a group of captive mangabeys (Cercocebus torquatus). We analysed several measurements related to aggression and affiliative patterns. The group adopted a combination of despotic and egalitarian behaviours resulting from the behavioural flexibility observed in the Cercopithecinae subfamily. Our study also demonstrates that the GrooFiWorld agent-based model can be extended to other members of the Cercopithecinae subfamily generating parsimonious hypotheses related to the social organization.
Resumo:
Internationally, policies for attracting highly-skilled migrants have become the guidelines mainly used by the Organisation for Economic Co-operation and Development (OECD) countries. Governments are implementing specific procedures to capture and facilitate their mobility. However, all professions are not equal when it comes to welcoming highly-skilled migrants. The medical profession, as a protective market, is one of these. Taking the case of non-EU/EEA doctors in France, this paper shows that the medical profession defined as the closed labour market, remains the most controversial in terms of professional integration of migrants, protectionist barriers to migrant competition and challenge of medical shortage. Based on the path-dependency approach, this paper argues that non-EU/EEA doctors' issues in France derive from a complex historical process of interaction between standards settled in the past, particularly the historical power of medical corporatism, the unexpected long-term effects of French hospital reforms of 1958, and budgetary pressures. Theoretically, this paper shows two significant findings. Firstly, the French medical system has undergone a series of transformations unthinkable in the strict sense of a path-dependence approach: an opening of the medical profession to foreign physicians in the context of the Europeanisation of public policy, acceptance of non-EU/EEA doctors in a context of medical shortage and budgetary pressures. Secondly, there is no change of the overall paradigm: significantly, the recruitment policies of non-EU/EEA doctors continue to highlight the imprint of the past and reveal a significant persistence of prejudices. Non-EU/EEA doctors are not considered legitimate doctors even if they have the qualifications of physicians which are legitimate in their country and which can be recognised in other receiving countries.
Resumo:
Nowadays, Wireless Sensor Networks (WSN) arealready a very important data source to obtain data about the environment. Thus, they are key to the creation of Cyber-Physical Systems (CPS). Given the popularity of P2P middlewares as ameans to efficiently process information and distribute services, being able to integrate them to WSN¿s is an interesting proposal. JXTA is a widely used P2P middleware that allows peers to easily exchange information, heavily relying on its main architectural highlight, the capability to organize peers with common interests into peer groups. However, right now, approaches to integrate WSNs to a JXTA network seldom take advantage of peer groups. For this reason, in this paper we present jxSensor, an integrationlayer for sensor motes which facilitates the deployment of CPS¿s under this architecture. This integration has been done taking into account JXTA¿s idiosyncrasies and proposing novel ideas,such as the Virtual Peer, a group of sensors that acts as a single entity within the peer group context.
Resumo:
La dermatite irritative est décrite comme une réaction réversible, non immunologique caractérisée par des lésions d'aspect très variable, allant de la simple rougeur jusqu'à la formation de bulles voire d'une nécrose, accompagnée de prurit ou d'une sensation de brûlure suite à I' application d'une substance chimique. Le teste de prédiction d'irritation cutanée est traditionnellement depuis les années 1940 le Test de Draize. Ce test consiste en l'application d'une substance chimique sur une peau rasée de lapin pendant 4h et de regarder à 24h si des signes cliniques d'irritations sont présents. Cette méthode critiquable autant d'un point de vue éthique que qualitative reste actuellement le teste le plus utilisé. Depuis le début des années 2000 de nouvelles méthodes in vitro se sont développées tel que le model d'épiderme humain recombiné (RHE). Il s agit d'une multicouche de kératinocyte bien différencié obtenu depuis une culture de don d'ovocyte. Cependant cette méthode en plus d'être très couteuse n'obtient au mieux que 76% de résultat similaire comparé au test in vivo humain. Il existe donc la nécessité de développer une nouvelle méthode in vitro qui simulerait encore mieux la réalité anatomique et physiologique retrouvée in vivo. Notre objectif a été de développer cette nouvelle méthode in vitro. Pour cela nous avons travaillé avec de la peau humaine directement prélevée après une abdominoplastie. Celle ci après préparation avec un dermatome, un couteau dont la lame est réglable pour découper l'épaisseur souhaitée de peau, est montée dans un système de diffusion cellulaire. La couche cornée est alors exposée de manière optimale à 1 ml de la substance chimique testée pendant 4h. L'échantillon de peau est alors fixé dans du formaldéhyde pour permettre la préparation de lames standards d'hématoxyline et éosine. L'irritation est alors investiguée selon des critères histopathologiques de spongioses, de nécroses et de vacuolisations cellulaires. Les résultats de ce.tte première batterie de testes sont plus que prometteurs. En effet, comparé au résultat in vivo, nous obtenons 100% de concordance pour les 4 même substances testes irritantes ou non irritantes, ce qui est supérieur au model d épiderme humain recombiné (76%). De plus le coefficient de variation entre les 3 différentes séries est inférieur à 0.1 ce qui montre une bonne reproductibilité dans un même laboratoire. Dans le futur cette méthode va devoir être testée avec un plus grand nombre de substances chimiques et sa reproductibilité évaluée dans différents laboratoires. Mais cette première evaluation, très encourageante, ouvre des pistes précieuses pour l'avenir des tests irritatifs.