994 resultados para Thermal challenge


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Fistulas are common complications in Crohn's disease, as their cumulative prevalence reaches up to two thirds of the patients in the long term. Fistulas worsen the overall patient prognosis, with permanent sphincter and perineal tissue destruction as well as professional and personal disabilities. The importance of healing these fistulas has been less well appreciated than mucosal healing for luminal disease. Management should not be left to any specialty alone, but requires an optimal combination of surgery, infection control, and immunosuppression. Outcome of therapy beyond fistula drainage is unclear and the means of assessing healing over a long time period is poorly characterized. Recent studies suggested that a substantial proportion of patients can achieve fistula healing with surgical and medical therapies. However, studies that measure the benefit of integrated approaches, of early intervention and of precise healing assessment are still missing. Such information is particularly needed in this subset of sick patients that undergo substantial physical and emotional distress because of pain, discharge, incontinence, perineal and genital disfigurement. The advent of adequate pelvic imaging, improved surgical outcomes, and potent biological therapies make it timely to develop best-management strategies and appropriateness of care criteria.

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Aim Understanding the stability of realised niches is crucial for predicting the responses of species to climate change. One approach is to evaluate the niche differences of populations of the same species that occupy regions that are geographically disconnected. Here, we assess niche conservatism along thermal gradients for 26 plant species with a disjunct distribution between the Alps and the Arctic. Location European Alps and Norwegian Finnmark. Methods We collected a comprehensive dataset of 26 arctic-alpine plant occurrences in two regions. We assessed niche conservatism through a multi-species comparison and analysed species rankings at cold and warm thermal limits along two distinct gradients corresponding to (1) air temperatures at 2 meters above ground level and (2) elevation distances to the treeline (TLD) for the two regions. We assessed whether observed relationships were close to those predicted under thermal limit conservatism. Results We found a weak similarity in species ranking at the warm thermal limits. The range of warm thermal limits for the 26 species was much larger in the Alps than in Finnmark. We found a stronger similarity in species ranking and correspondence at the cold thermal limit along the gradients of 2-m temperature and TLD. Yet, along the 2-m temperature gradient, the cold thermal limits of species in the Alps were lower on average than those in Finnmark. Main conclusion We found low conservatism of the warm thermal limits but a stronger conservatism of the cold thermal limits. We suggest that biotic interactions at the warm thermal limit likely modulate species responses more strongly than at the cold limit. The differing biotic context between the two regions is likely responsible for the observed differences in realised niches.

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Female genital mutilation (FGM) is defined as an injury of the external female genitalia for cultural or non-therapeutic reasons. FGM is mainly performed in sub-Saharan and Eastern Africa. The western health care systems are confronted with migrants from this cultural background. The aim is to offer information on how to approach this subject. The degree of FGM can vary from excision of the prepuce and clitoris to infibulation. Infections, urinary retention, pain, lesions of neighbouring organs, bleeding, psychological trauma and even death are possible acute complications. The different long-term complications include the risk of reduced fertility and difficulties during labour, which are key arguments against FGM in the migrant community. Paediatricians often have questions on how to approach the subject. With an open, neutral approach and basic knowledge, discussions with parents are constructive. Talking about the newborn, delivery or traditions may be a good starting point. Once they feel accepted, they speak surprisingly openly. FGM is performed out of love for their daughters. We have to be aware of their arguments and fears, but we should also stress the parents' responsibility in taking a health risk for their daughters. It is important to know the family's opinion on FGM. Some may need support, especially against community pressure. As FGM is often performed on newborns or at 4-9 years of age, paediatricians should have an active role in the prevention of FGM, especially as they have repeated close contact with those concerned and medical consequences are the main arguments against FGM.

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The concomitant immunity in the presence of repeated infections (with 15 cercariae) was studied in mice sacrificed on the 20th day after each infection. The comparison of the averages of immature worms, recovered from mice submitted to reinfection, with those of their respective controls (previously uninfected) showed a significantly lower worm recovery rate in the animals with previous infections (concomitant immunity). However, statiscally significant differences could not be detected among the various groups of animals, when the mice that accumulated worms in this mature stage were perfused. The theoretical projection based on the accumulation of young worms which developed to adult ones indicates a lower recovery rate of adult worms in the animals with concomitant immunity, but this projection was not corroborated by the experimental data. The visceral hemodynamic alterations that occurred in reinfections due to the pathogeny, favouring recirculation of the recent arriving worms to the other organs on the occasion of perfusion of the portal system. These results suggest that special care should be taken when one wants to investigate concomitant immunity in mice based on the distinction of the immature worms from challenge infection and the mature ones from primary infection.

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A sound statistical methodology is presented for modelling the correspondence between the characteristics of individuals, their thermal environment, and their thermal sensation. The proposed methodology substantially improves that developed by P.O. Fanger, by formulating a more general and precise model of thermal comfort. It enables us to estimate the model from a sample of data where all the parameters of comfort vary at the same time, which is not possible with that adopted by Fanger. Moreover, the present model is still valid when thermal conditions are far from optimum. (C) 1997 Elsevier Science Ltd.

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The snails Lymnaea (Radix) luteola exhibited marked variations in growth, longevity, and attaining sexual maturity at different temperatures and diets. At 10°C, irrespective of foods, pH and salinity of water, the snails had minimum life span, maximum death rate and lowest growth rate. At 15°C, the growth rate was comparatively higher and the snails survived for a few more days. But at these temperatures they failed to attain sexual maturity. Snails exposed to pH 5 and 9 at 20°, 25°, 30°, 35°C and room temperatures (19.6°-29.6°C); to 0.5, 1.5 and 2.5 NaCl ‰ at 20° and 35ºC; to 2.5 NaCl ‰ at 25°C and room temperatures failed to attain sexual maturity. The snails exposed to pH 7 and different salinity grades at 20°, 25°, 30°, 35°C and room temperatures became sexually mature between 25-93 days depending upon the type of foods used in the culture.

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A gradual increase in Earth's surface temperatures marking the transition from the late Paleocene to early Eocene (55.8±0.2Ma), represents an extraordinary warming event known as Paleocene-Eocene Thermal Maximum (PETM). Both marine and continental sedimentary records during this period reveal evidences for the massive injection of isotopically light carbon. The carbon dioxide injection from multiple potential sources may have triggered the global warming. The importance of the PETM studies is due to the fact that the PETM bears some striking resemblances to the human-caused climate change unfolding today. Most notably, the culprit behind it was a massive injection of heat-trapping greenhouse gases into the atmosphere and oceans, comparable in volume to what our persistent burning of fossil fuels could deliver in coming centuries. The exact knowledge of what went on during the PETM could help us to foresee the future climate change. The response of the oceanic and continental environments to the PETM is different. Many factors might control the response of the environments to the PETM such as paleogeography, paleotopography, paleoenvironment, and paleodepth. To better understand the mechanisms triggering PETM events, two different environments were studied: 1) shallow marine to inner shelf environment (Wadi Nukhul, Sinai; and the Dababiya GSSP, Luxor, Egypt), and 2) terrestrial environments (northwestern India lignite mines) representing wetland, and fluvial environments (Esplugafreda, Spain) both highlighting the climatic changes observed in continental conditions. In the marine realm, the PETM is characterized by negative ö13Ccar and ô13Corg excursions and shifts in Ô15N to ~0%o values above the P/E boundary and persisting along the interval suggesting a bloom and high production of atmospheric N2-fixers. Decrease in carbonate contents could be due to dissolution and/or dilution by increasing detrital input. High Ti, K and Zr and decreased Si contents at the P/E boundary indicate high weathering index (CIA), which coincides with significant kaolinite input and suggests intense chemical weathering under humid conditions at the beginning of the PETM. Two anoxic intervals are observed along the PETM. The lower one may be linked to methane released from the continental shelf with no change in the redox proxies, where the upper anoxic to euxinic conditions are revealed by increasing U, Mo, V, Fe and the presence of small size pyrite framboids (2-5fim). Productivity sensitive elements (Cu, Ni, and Cd) show their maximum concentrated within the upper anoxic interval suggesting high productivity in surface water. The obtained data highlight that intense weathering and subsequent nutrient inputs are crucial parameters in the chain of the PETM events, triggering productivity during the recovery phase. In the terrestrial environments, the establishment of wetland conditions and consequence continental climatic shift towards more humid conditions led to migration of modern mammals northward following the extension of the tropical belts. Relative ages of this mammal event based on bio-chemo- and paleomagnetic stratigraphy support a migration path originating from Asia into Europe and North America, followed by later migration from Asia into India and suggests a barrier to migration that is likely linked to the timing of the India-Asia collision. In contrast, at Esplugafereda, northeastern Spain, the terrestrial environment reacted differently. Two significant S13C shifts with the lower one linked to the PETM and the upper corresponding to the Early Eocene Thermal Maximum (ETM2); 180/160 paleothermometry performed on two different soil carbonate nodule reveal a temperature increase of around 8°C during the PETM. The prominent increase in kaolinite content within the PETM is linked to increased runoff and/or weathering of adjacent and coeval soils. These results demonstrate that the PETM coincides globally with extreme climatic fluctuations and that terrestrial environments are very likely to record such climatic changes. - La transition Paléocène-Eocène (55,8±0,2 Ma) est marquée par un réchauffement extraordinaire communément appelé « Paleocene-Eocene Thermal Maximum » (PETM). Les données géochimiques caractérisant les sédiments marins et continentaux de cette période indiquent que ce réchauffement a été déclenché par une augmentation massive de CO2 lié à la déstabilisation des hydrates de méthane stockés le long des marges océaniques. L'étude des événements PETM constitue donc un bon analogue avec le réchauffement actuel. Le volume de CO2 émis durant le PETM est comparable avec le CO2 lié à l'activité actuelle humaine. La compréhension des causes du réchauffement du PETM peut être cruciale pour prévoir et évaluer les conséquences du réchauffement anthropogénique, en particulier les répercussions d'un tel réchauffement sur les domaines continentaux et océaniques. De nombreux facteurs entrent en ligne de compte dans le cas du PETM, tels que la paléogéographie, la paléotopographie et les paléoenvironnement. Pour mieux comprendre les réponses environnementales aux événements du PETM, 2 types d'environnements ont été choisis : (1) le domaine marin ouvert mais relativement peu profond (Wadi Nukhul. Sinai, Dababiya, Luxor, Egypte), (2) le milieu continental marécageux humide (mines de lignite, Inde) et fluviatile, semi-aride (Esplugafreda, Pyrénées espagnoles). Dans le domaine marin, le PETM est caractérisé par des excursions négatives du ô13Ccar et ô13Corg et un shift persistant des valeurs de 815N à ~ 0 %o indiquant une forte activité des organismes (bactéries) fixant l'azote. La diminution des carbonates observée durant le PETM peut-être due à des phénomènes de dissolution ou une augmentation des apports terrigènes. Des taux élevés en Ti, K et Zr et une diminution des montants de Si, reflétés par des valeurs des indices d'altération (CIA) qui coïncident avec une augmentation significative des apports de kaolinite impliquent une altération chimique accrue, du fait de conditions plus humides au début du PETM. Deux événements anoxiques globaux ont été mis en évidence durant le PETM. Le premier, situé dans la partie inférieur du PETM, serait lié à la libération des hydrates de méthane stockés le long des talus continentaux et ne correspond pas à des variations significatives des éléments sensibles aux changements de conditions redox. Le second est caractérisé par une augmentation des éléments U, Mo, V et Fe et la présence de petit framboids de pyrite dont la taille varie entre 2 et 5pm. Le second épisode anoxique est caractérisé par une forte augmentation des éléments sensibles aux changements de la productivité (Cu, Ni et Co), indiquant une augmentation de la productivité dans les eaux de surface. Les données obtenues mettent en évidence le rôle crucial joué par l'altération et les apports en nutriments qui en découlent. Ces paramètres sont cruciaux pour la succession des événements qui ont conduit au PETM, et plus particulièrement l'augmentation de la productivité dans la phase de récupération. Durant le PETM, le milieu continental est caractérisé par l'établissement de conditions humides qui ont facilité voir provoqué la migration des mammifères modernes qui ont suivi le déplacement de ces ceintures climatiques. L'âge de cette migration est basé sur des arguments chimiostratigraphiques (isotopes stables), biostratigraphiques et paléomagnétiques. Les données bibliographiques ainsi que celles que nous avons récoltées en Inde, montrent que les mammifères modernes ont d'abord migré depuis l'Asie vers l'Europe, puis dans le continent Nord américain. Ces derniers ne sont arrivés en Inde que plus tardivement, suggérant que le temps de leur migration est lié à la collision Inde-Asie. Dans le Nord-Est de l'Espagne (Esplugafreda), la réponse du milieu continental aux événements PETM est assez différente. Comme en Inde, deux excursions signicatives en ô13C ont été observées. La première correspond au PETM et la seconde est corrélée avec l'optimum thermique de l'Eocène précoce (ETM2). Les isotopes stables de l'oxygène mesurés 2 différents types de nodules calcaires provenant de paléosols suggère une augmentation de 10°C pendant le PETM. Une augmentation simultanée des taux de kaolinite indique une intensification de l'altération chimique et/ou de l'érosion de sols adjacents. Ces résultats démontrent que le PETM coïncide globalement avec des variations climatiques extrêmes qui sont très aisément reconnaissables dans les dépôts continentaux.

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The detection of latent fingermarks on thermal papers proves to be particularly challenging because the application of conventional detection techniques may turn the sample dark grey or black, thus preventing the observation of fingermarks. Various approaches aiming at avoiding or solving this problem have been suggested. However, in view of the many propositions available in the literature, it gets difficult to choose the most advantageous method and to decide which processing sequence should be followed when dealing with a thermal paper. In this study, 19 detection techniques adapted to the processing of thermal papers were assessed individually and then were compared to each other. An updated processing sequence, assessed through a pseudo-operational test, is suggested.

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In this paper the two main drawbacks of the heat balance integral methods are examined. Firstly we investigate the choice of approximating function. For a standard polynomial form it is shown that combining the Heat Balance and Refined Integral methods to determine the power of the highest order term will either lead to the same, or more often, greatly improved accuracy on standard methods. Secondly we examine thermal problems with a time-dependent boundary condition. In doing so we develop a logarithmic approximating function. This new function allows us to model moving peaks in the temperature profile, a feature that previous heat balance methods cannot capture. If the boundary temperature varies so that at some time t & 0 it equals the far-field temperature, then standard methods predict that the temperature is everywhere at this constant value. The new method predicts the correct behaviour. It is also shown that this function provides even more accurate results, when coupled with the new CIM, than the polynomial profile. Analysis primarily focuses on a specified constant boundary temperature and is then extended to constant flux, Newton cooling and time dependent boundary conditions.

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Both Leishmania major and L. braziliensis induce cutaneous leishmaniasis in BALB/c mice. Whereas BALB/c mice die of infection with L. major, they cure an infection with L. braziliensis. We report here that after curing an infection with L. braziliensis, BALB/c mice are resistant to challenge with L. major. When challenged with L. major, L. braziliensis pre-treated BALB/c mice mounted a delayed-type hypersensitivity response to L. major and produced high amounts of interferon-g (IFN-g ) but low amounts of interleukin-4. The IFN-g produced by the L. braziliensis pre-infected mice was involved in the protection seen against L. major challenge since treating the mice with a neutralizing anti-IFN-g abrogated the protection. This suggests that cross-reactive antigen epitopes exist between L. braziliensis and L. major and that pre-infection with L. braziliensis primes BALB/c mice to epitopes on L. major that can elicit a protective Th1 response to the parasite.

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The economic recession with its accompanying rise in unemployment rates is linked to extremely adverse effects for men’s mental health. This research report Facing the Challenge – The Impact of the Recession and Unemployment on Men’s Health in Ireland identifies a strong expectation of increased mental health problems for men given the very strong correlation between unemployment and male mental ill health. The report is the result of a research and consultation process carried out, in Northern Ireland and the Republic of Ireland, by Nexus Research Co-operative on behalf of IPH. 93% of frontline organisations, North and South, in contact with unemployed men linked health challenges to unemployment and recession and all organisations surveyed noted adverse health challenges for men they work with. In addition to health challenges being higher for unemployed men, they were also very high for men who saw themselves as being threatened with unemployment. The organisations surveyed and the men who were interviewed identified the challenges to health as:•    High levels of stress or anxiety•    Dependency on or over-use of alcohol/other drugs•    Deterioration in physical health•    Development of conflict in family or close personal relationships•    Isolation (including sharing or communicating problems)•    A reluctance to approach services or seek help