440 research outputs found

    A procedure for designing natural water retention measures in new development areas under hydraulic-hydrologic invariance constraints

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    In recent years, in Italy and elsewhere, regional regulations based on hydraulic-hydrologic invariance (HHI) principles have taken hold, especially for new development areas. Natural water retention measures (NWRMs) are among the most interesting options to provide the storage and infiltration capacities that are needed to achieve the HHI objectives. A procedure for the design of NWRMs in new development areas under HHI constraints is presented and is based on a simple combination of Soil Conservation Service Curve Number (SCS-CN) method for determining rainfall excess and lag-time method for simulating runoff propagation. Three types of NWRMs can be considered: rain barrels, drainage wells and drainage trenches; five types of synthetic hyetographs can be selected and three different approaches for the determination of critical storm duration applied. The results obtained by applying the procedure in a new development area located in northern Italy are illustrated and some general conclusions are drawn. It clearly emerges that practitioners should pay particular attention to the correct determination of design storm duration in order to avoid large underestimations of NWRMs size. Moreover, different combinations of the three NWRMs can provide the required reduction of peak of runoff after the transformation, but it appears that drainage trenches are more effective with respect to harvesting systems in reducing the peak runoff value

    Changes in diet and trophic position of a top predator 10 years after a mass mortality of a key prey

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    After the disappearance of primary prey, seabirds exhibit gradually decreased breeding performance, and eventually the population size drops. Results are presented of an investigation into the diet of little penguins (Eudyptula minor) at Phillip Island, Australia, during a period when their key prey, pilchard (Sardinops sagax), declined dramatically. Data from stomach flushing (1982-2006) were used, supported by stable isotope (δ 15N, δ13C) analyses of blood samples (2003, 2004, and 2006). The effect of the pilchard mortality on penguin diet was immediate, the birds shifting to a diet almost devoid of pilchard, and this was followed by 2 years of low breeding success, with considerably fewer penguins coming ashore. During periods when pilchard was not part of the diet, penguins consumed prey of a higher trophic level, e.g. higher values of δ15N. Variability in penguin blood δ15N coincided with years of low prey diversity. The disappearance of pilchard resulted in a decrease in prey diversity and led penguins to >fish up> the foodweb, possibly because of the simplified trophic structure. After 1998, however, breeding success re-attained average levels and the numbers of penguins coming ashore increased, probably because of increased abundance of prey other than pilchard after a 3-year period of food scarcity. Although little penguins apparently compensated over time, a less-flexible diet could make them ultimately vulnerable to further changes in their foodweb. © 2010 International Council for the Exploration of the Sea.Peer Reviewe

    A novel spatio-temporal scale based on ocean currents unravels environmental drivers of reproductive timing in a marine predator

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    Life-history strategies have evolved in response to predictable patterns of environmental features. In practice, linking life-history strategies and changes in environmental conditions requires comparable space–time scales between both processes, a difficult match in most marine system studies. We propose a novel spatio-temporal and dynamic scale to explore marine productivity patterns probably driving reproductive timing in the inshore little penguin (Eudyptula minor), based on monthly data on ocean circulation in the Southern Ocean, Australia. In contrast to what occurred when considering any other fixed scales, little penguin's highly variable laying date always occurred within the annual peak of ocean productivity that emerged from our newly defined dynamic scale. Additionally, local sea surface temperature seems to have triggered the onset of reproduction, acting as an environmental cue informing on marine productivity patterns at our dynamic scale. Chlorophyll-a patterns extracted from this scale revealed that environment factors in marine ecosystems affecting breeding decisions are related to a much wider region than foraging areas that are commonly used in current studies investigating the link between animals' life history and their environment. We suggest that marine productivity patterns may be more predictable than previously thought when environmental and biological data are examined at appropriate scales.Peer reviewe

    Global approaches and local strategies for phase unwrapping

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    Phase unwrapping, i.e. the retrieval of absolute phases from wrapped, noisy measures, is a tough problem because of the presence of rotational inconsistencies (residues), randomly generated by noise and undersampling on the principal phase gradient field. These inconsistencies prevent the recovery of the absolute phase field by direct integration of the wrapped gradients. In this paper we examine the relative merit of known global approaches and then we present evidence that our approach based on “stochastic annealing” can recover the true phase field also in noisy areas with severe undersampling, where other methods fail. Then, some experiments with local approaches are presented. A fast neural filter has been trained to eliminate close residue couples by joining them in a way which takes into account the local phase information. Performances are about 60–70% of the residues. Finally, other experiments have been aimed at designing an automated method for the determination of weight matrices to use in conjunction with local phase unwrapping algorithms. The method, tested with the minimum cost flow algorithm, gives good performances over both simulated and real data

    Diet segregation between two colonies of little penguins Eudyptula minor in southeast Australia

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    We studied foraging segregation between two different sized colonies of little penguins Eudyptula minor with overlapping foraging areas in pre-laying and incubation. We used stomach contents and stable isotope measurements of nitrogen (δ 15N) and carbon (δ 13C) in blood to examine differences in trophic position, prey-size and nutritional values between the two colonies. Diet of little penguins at St Kilda (small colony) relied heavily on anchovy while at Phillip Island (large colony), the diet was more diverse and anchovies were larger than those consumed by St Kilda penguins. Higher δ 15N values at St Kilda, differences in δ 13C values and the prey composition provided further evidence of diet segregation between colonies. Penguins from each colony took anchovies from different cohorts and probably different stocks, although these sites are only 70km apart. Differences in diet were not reflected in protein levels in the blood of penguins, suggesting that variation in prey between colonies was not related to differences in nutritional value of the diet. Anchovy is currently the only available prey to penguins throughout the year and its absence could have a negative impact on penguin food supply, particularly at St Kilda where the diet is dominated by this species. While it is difficult to establish whether diet segregation is caused by inter- or intra-colony competition or spatial differences in foraging areas, we have shown that colonies with broadly overlapping foraging ranges could have significant differences in trophic position, diet composition and prey size while maintaining a diet of similar nutritional value. © 2011 The Authors. Austral Ecology © 2011 Ecological Society of Australia.Peer Reviewe

    Epidemiology and direct medical costs of human Leishmaniasis in Italy

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    INTRODUCTION: Osteoarthrosis is the most prevalent joints disorder and it is also the most frequent cause of physical disability in the elderly. When surgery is not indicated, symptomatic drugs are generally used. These treatments are frequently associated to balneotherapy. In fact, balneotherapy or spa therapy has been widely used in classical medicine as a cure for such diseases. The aim and significance of this study is to evaluate the impact of thermalism in subjects suffering from osteoarthrosis. METHODS: We randomly selected 220 osteoarthrosic subjects (STs = spa treatment subjects), aged from 40 to 90, that usually undergone mud pack therapy and balneotherapy at least once a year. They were enrolled in thermal establishments in the Euganean Basin. We also recruited, as control group, 172 osteoarthrosic subjects (NCs = normal care subjects) that never underwent any spa therapy. A questionnaire, comprehensive of a disability score, was administered by physicians to each subject. RESULTS: STs reported to suffer from osteoarthrosis for more years than NCs. Furthermore STs significantly suffered more than NCs from pain in several joints, and they also showed a more elevated average number of painful joints. In spite of that, STs used less drugs than NCs, and showed a higher degree of disability due to osteoarthrosis (p inf.0.001). CONCLUSION: The regular use of mudpack and balneotherapy seem to improve the wellness, and the spa treatment seems to help the achievement of this goal. In this regard it might be important to encourage new investigations in order to assess in which measure thermal therapy contribute to the wellness improvemen

    Appropriateness of admission and days of stay in pediatric hospital in Ancona, Italy

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    Background: In Italy, hospital admission costs account for nearly 42% of total health expenditure; in the Marche region, this share exceeds 50%. High costs of hospitalization, however, can be partly explained by inappropriate use. The aim of this research was to assess the risk factors associated with inappropriate hospital admissions and stay for acute pediatric patients. Methods: Clinical records of children from 30 days to 14 years of age admitted to the wards of orthopedics, pediatrics, pediatric isolation, pediatric surgery and pediatric oncohematology at Salesi Pediatric Hospital of Ancona throughout 2004 were reviewed. The Italian Pediatric Appropriateness Evaluation Protocol (PRUO) was used as a tool for assessing inappropriateness of admission and days of stay. Results: Overall 21.7% (95% CI = 16.1%–22.4%) of hospital admissions and 30.3% (95% CI = 26.0%–34.9%) of days of stay were judged to be inappropriate. Multiple logistic regression analysis indicated that inappropriate admission was significantly associated with type of admission, discharge ward and place of residence. Inappropriateness of stay was significantly higher if admission was to a medical ward and if admission itself was judged inappropriate. Conclusions: In a socioeconomic context in which reducing waste is necessary, ineffective health care interventions are no longer tolerable. As a tool capable of integrating each patient’s specific features with those of the health care process, the pediatric PRUO could be a valid tool in the hands of managers for monitoring the appropriateness of admission and stay

    Intra-articular administration of lidocaine plus adrenaline in dogs : pharmacokinetic profile and evaluation of toxicity in vivo and in vitro

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    The aim of this study was to evaluate the safety of intra-articular (IA) lidocaine plus adrenaline for improving peri-operative analgesia in anaesthetised dogs undergoing arthroscopy of the elbow. A solution of lidocaine (L) 1.98% plus adrenaline 1:100.000 was administered via the IA route and its safety evaluated in terms of cardio- neuro- and chondro-toxicity. No bradycardia or hypotension was recorded from induction to the last observational time point. Signs of toxicity of the nervous system could have been masked by the general anaesthesia but lidocaine concentrations detected in the blood were lower than those thought to be capable of producing toxicity. The assessment of in vitro chondrotoxicity showed a dose- and time-dependent effect of lidocaine on the viability of articular cells. Adrenaline appeared to reduce the chondrotoxicity of 1% lidocaine, following an exposure of up to 30 min
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