737 research outputs found

    Uncorrected land-use planning highlighted by flooding: the Alba case study (Piedmont, Italy)

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    Alba is a town of over 30 000 inhabitants located along the Tanaro River (Piedmont, northwestern Italy) and is famous for its wine and white truffles. Many important industries and companies are based in Alba, including the famous confectionery group Ferrero. <br><br> The town suffered considerably from a flood that occurred on 5–6 November 1994. Forty-eight percent of the urban area was inundated, causing severe damage and killing nine people. After the flood, the Alba area was analysed in detail to determine the reasons for its vulnerability. <br><br> Information on serious floods in this area since 1800 was gathered from official records, state technical office reports, unpublished documents in the municipal archives, and articles published in local and national newspapers. Maps, plans and aerial photographs (since 1954) were examined to reconstruct Alba's urban development over the last two centuries and the planform changes of the Tanaro River. <br><br> The results were compared with the effects of the November 1994 flood, which was mapped from aerial photographs taken immediately after the flood, field surveys and eyewitness reports. <br><br> The territory of Alba was subdivided into six categories: residential; public service; industrial, commercial and hotels; sports areas, utilities and standards (public gardens, parks, athletics grounds, private and public sport clubs); aggregate plants and dumps; and agriculture and riverine strip. The six categories were then grouped into three classes with different flooding-vulnerability levels according to various parameters. Using GIS, the three river corridors along the Tanaro identified by the Autorità di Bacino del Fiume Po were overlaid on the three classes to produce a final map of the risk areas. <br><br> This study shows that the historic floods and their dynamics have not been duly considered in the land-use planning of Alba. The zones that were most heavily damaged in the 1994 flood were those that were frequently affected in the past and sites of more recent urbanisation. Despite recurrent severe flooding of the Tanaro River and its tributaries, areas along the riverbed and its paleochannels have been increasingly used for infrastructure and building (e.g., roads, a municipal dump, a prison, natural aggregate plants, a nomad camp), which has often interfered with the natural spread of the floodwaters. Since the 1994 flood, many remedial projects have been completed along the Tanaro and its tributaries, including levees, bank protection, concrete walls and floodway channels. In spite of these costly projects, some areas remain at high risk for flooding. <br><br> The method used, which considered historical data, river corridors identified by hydraulic calculations, geomorphological aspects and land-use planning, can indicate with good accuracy flood-prone areas and in consequence to be an useful tool for the coherent planning of urban expansion and the mitigation of flood risk

    Geo-hydrological risk mitigation in a terraced landscape: LiDAR data analysis in the Portofino natural Park, Italy

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    Modification of steep slopes with man-made terraces is an ancient and widespread habit in many areas of the world. If the modification assures agricultural practices in mountainous areas, it results even as an important interference with the geomorphic processes: important quantities of soil and sediments are subtracted to the degradation processes and, in case of total abandonment of terraces, they result again available to erosion. Intense rain event may cause partial instability or even collapse of the anthropogenic structures, configuring terraces as an additional source of Geo-hydrological hazard. Recent events in Liguria - northern Italy, in Cinque Terre 2011 and Leivi (Chiavari) 2014, caused damages and even casualties due to the sudden collapse of terraced slopes. A crucial point in assessing the potential hazard caused by abandoned terraced slopes is identifying their real extension. LiDAR data analysis is an important assessment tool particularly in strong steepness areas due to the capability of recognizing linear regular structures. In the present research LiDAR data analysis has been used to identify terraces in the Portofino Natural Park area (Liguria region, Italy) as one of the preliminary activities of the RECONECT European Union\u2019s Horizon 2020 Research and Innovation Programme project. The project plans to realize nature based solutions to mitigate geohydrological risk in two pilot areas in the Portofino promontory and the recovery of terraces is one of the foreseen actions. Mapping terraces is the first step to evaluate the potential risk associated to the possible instability processes and the interventions to be realized. Land use evolution in the area from 1800 to present have been indeed found through historical maps examination and used in conjunction with LiDAR analysis results

    A spatial multicriteria prioritizing approach for geo-hydrological risk mitigation planning in small and densely urbanized Mediterranean basins

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    Landslides and floods, particularly flash floods, occurred recently in many Mediterranean catchments as a consequence of heavy rainfall events, causing damage and sometimes casualties. The high hazard is often associated with high vulnerability deriving from intense urbanization, in particular along the coastline where streams are habitually culverted. The necessary risk mitigation strategies should be applied at the catchment scale with a holistic approach, avoiding spot interventions. In the present work, a high-risk area, hit in the past by several floods and concurrent superficial landslides due to extremely localized and intense rain events, has been studied. A total of 21 small catchments have been identified: only some of them have been hit by extremely damaging past events, but all lie in the intense-rain high-hazard area and are strongly urbanized in the lower coastal zone. The question is what would happen if an intense rain event should strike one of the not previously hit catchments; some situations could be worse or not, so attention has been focused on the comparison among catchments. The aim of the research has been identifying a priority scale among catchments, pointing out the more critical ones and giving a quantitative comparison tool for decision makers to support strong scheduling of long-time planning interventions at the catchment scale. The past events' effects and the geomorphic process analysis together with the field survey allowed us to select three sets of parameters: one describing the morphometric–morphological features related to flood and landslide hazard, another describing the degree of urbanization and of anthropogenic modifications at the catchment scale and the last related to the elements that are exposed to risk. The realized geodatabase allowed us to apply the spatial multicriteria analysis technique (S-MCA) to the descriptive parameters and to obtain a priority scale among the analyzed catchments. The scale can be used to plan risk mitigation interventions starting from the more critical catchments, then focusing economic resources primarily on them and obtaining an effective prevention strategy. The methodology could be useful even to check how the priority scale is modified during the progress of the mitigation work realization. In addition, this approach could be applied in a similar context, even among sub-catchments, after identifying a suitable set of descriptive parameters depending on the active geomorphological processes and the kind of anthropogenic modification. The prioritization would allow to invest economic resources in risk mitigation interventions priory in the more critical catchments.</p

    Nutritional and Plasma Antioxidant Status Assessment in a Group of Old Alzheimer\u2019s Inpatients

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    This study was carried out to assess the nutritional and plasma antioxidant status of Alzheimer\u2019s inpatients compared to age-matched controls by means of anthropometric measurements, neuropsychological and nutritional tests and plasma biomarkers. Assessment of nutritional biomarkers of prooxidant/antioxidant balance in patients with AD as well as nutritional status and neuropsychological evaluation are important since many studies have demonstrated their association with cognitive impairment. This cross sectional study was carried out in 35 subjects recruited in a geriatric institution in Pavia, Northern Italy. Cases mean Body Mass Index (BMI) was lower than controls\u2019 one as well as mid arm circumference, triceps skinfold and arm muscle circumference. Both inpatients MNA and MMSE mean scores were lower than controls ones. Plasma levels of lutein plus zeaxanthin, beta-cryptoxanthin, lycopene, alfa tocopherol, ascorbic acid were significantly lower (p < 0.05) in AD in patients as well as superoxide desmutase and glutathione peroxidase concentrations, while all the other biochemical markers levels did not differ. Plasma antioxidant levels and activities were decreased in AD and could be biologically predictive of an early mild cognitive decline, suggesting early intervention on dietary antioxidant intake

    A meta-analysis of peripheral tocopherol levels in age-related cognitive decline and Alzheimer's disease.

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    Objectives: Findings from observational studies and clinical trials on the associations between vitamin E and dementia remain controversial. Here we conducted a meta-analysis to determine the difference in blood tocopherols levels between patients with Alzheimer's disease (AD) or age-related poor cognitive function and healthy controls.Methods: Standardised mean difference (SMD) and 95% confidence intervals (CIs) were calculated and entered into a random effects model. Study quality, heterogeneity and publication bias were also investigated.Results: Thirty-one articles were included in the meta-analysis, which included analyses for α-, β-, γ- and δ-tocopherols. These results indicated that individuals with AD or age-related cognitive deficits and mild cognitive impairment (MCI) had lower circulatory concentrations of α-tocophenol compared with healthy controls (AD: SMD = -0.97, 95% confidence interval [CI] = -1.27 to -0.68, Z = 6.45, P < 0.00001; age-related cognitive deficits and MCI: SMD = -0.72, 95% CI = -1.12 to -0.32, Z = -3., P < 0.0005). Levels of β-, γ- and δ-tocophenols did not significantly differ between groups of AD and age-related cognitive deficits compared to controls.Discussion: These results suggest that lower α-tocopherol levels have a strong association with AD and MCI supporting evidence for the role of diet and vitamin E in AD risk and age-related cognitive decline

    Processing Ordinality and Quantity: The Case of Developmental Dyscalculia

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    In contrast to quantity processing, up to date, the nature of ordinality has received little attention from researchers despite the fact that both quantity and ordinality are embodied in numerical information. Here we ask if there are two separate core systems that lie at the foundations of numerical cognition: (1) the traditionally and well accepted numerical magnitude system but also (2) core system for representing ordinal information. We report two novel experiments of ordinal processing that explored the relation between ordinal and numerical information processing in typically developing adults and adults with developmental dyscalculia (DD). Participants made “ordered” or “non-ordered” judgments about 3 groups of dots (non-symbolic numerical stimuli; in Experiment 1) and 3 numbers (symbolic task: Experiment 2). In contrast to previous findings and arguments about quantity deficit in DD participants, when quantity and ordinality are dissociated (as in the current tasks), DD participants exhibited a normal ratio effect in the non-symbolic ordinal task. They did not show, however, the ordinality effect. Ordinality effect in DD appeared only when area and density were randomized, but only in the descending direction. In the symbolic task, the ordinality effect was modulated by ratio and direction in both groups. These findings suggest that there might be two separate cognitive representations of ordinal and quantity information and that linguistic knowledge may facilitate estimation of ordinal information

    A Prognostic Model for Estimating the Time to Virologic Failure in HIV-1 Infected Patients Undergoing a New Combination Antiretroviral Therapy Regimen

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    <p>Abstract</p> <p>Background</p> <p>HIV-1 genotypic susceptibility scores (GSSs) were proven to be significant prognostic factors of fixed time-point virologic outcomes after combination antiretroviral therapy (cART) switch/initiation. However, their relative-hazard for the time to virologic failure has not been thoroughly investigated, and an expert system that is able to predict how long a new cART regimen will remain effective has never been designed.</p> <p>Methods</p> <p>We analyzed patients of the Italian ARCA cohort starting a new cART from 1999 onwards either after virologic failure or as treatment-naïve. The time to virologic failure was the endpoint, from the 90<sup>th </sup>day after treatment start, defined as the first HIV-1 RNA > 400 copies/ml, censoring at last available HIV-1 RNA before treatment discontinuation. We assessed the relative hazard/importance of GSSs according to distinct interpretation systems (Rega, ANRS and HIVdb) and other covariates by means of Cox regression and random survival forests (RSF). Prediction models were validated via the bootstrap and c-index measure.</p> <p>Results</p> <p>The dataset included 2337 regimens from 2182 patients, of which 733 were previously treatment-naïve. We observed 1067 virologic failures over 2820 persons-years. Multivariable analysis revealed that low GSSs of cART were independently associated with the hazard of a virologic failure, along with several other covariates. Evaluation of predictive performance yielded a modest ability of the Cox regression to predict the virologic endpoint (c-index≈0.70), while RSF showed a better performance (c-index≈0.73, p < 0.0001 vs. Cox regression). Variable importance according to RSF was concordant with the Cox hazards.</p> <p>Conclusions</p> <p>GSSs of cART and several other covariates were investigated using linear and non-linear survival analysis. RSF models are a promising approach for the development of a reliable system that predicts time to virologic failure better than Cox regression. Such models might represent a significant improvement over the current methods for monitoring and optimization of cART.</p

    Digalactosyl-diacylglycerol-deficiency lowers the thermal stability of thylakoid membranes

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    We investigated the effects of digalactosyl-diacylglycerol (DGDG) on the organization and thermal stability of thylakoid membranes, using wild-type Arabidopsis thaliana and the DGDG-deficient mutant, dgd1. Circular-dichroism measurements reveal that DGDG-deficiency hampers the formation of the chirally organized macrodomains containing the main chlorophyll a/b light-harvesting complexes. The mutation also brings about changes in the overall chlorophyll fluorescence lifetimes, measured in whole leaves as well as in isolated thylakoids. As shown by time-resolved measurements, using the lipophylic fluorescence probe Merocyanine 540 (MC540), the altered lipid composition affects the packing of lipids in the thylakoid membranes but, as revealed by flash-induced electrochromic absorbance changes, the membranes retain their ability for energization. Thermal stability measurements revealed more significant differences. The disassembly of the chiral macrodomains around 55°C, the thermal destabilization of photosystem I complex at 61°C as detected by green gel electrophoresis, as well as the sharp drop in the overall chlorophyll fluorescence lifetime above 45°C (values for the wild type—WT) occur at 4–7°C lower temperatures in dgd1. Similar differences are revealed in the temperature dependence of the lipid packing and the membrane permeability: at elevated temperatures MC540 appears to be extruded from the dgd1 membrane bilayer around 35°C, whereas in WT, it remains lipid-bound up to 45°C and dgd1 and WT membranes become leaky around 35 and 45°C, respectively. It is concluded that DGDG plays important roles in the overall organization of thylakoid membranes especially at elevated temperatures

    Is Mn-Bound Substrate Water Protonated in the S2 State of Photosystem II?

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    In spite of great progress in resolving the geometric structure of the water-splitting Mn4OxCa cluster in photosystem II, the binding sites and modes of the two substrate water molecules are still insufficiently characterized. While time-resolved membrane-inlet mass spectrometry measurements indicate that both substrate water molecules are bound to the oxygen-evolving complex (OEC) in the S2 and S3 states (Hendry and Wydrzynski in Biochemistry 41:13328–13334, 2002), it is not known (1) if they are both Mn-bound, (2) if they are terminal or bridging ligands, and (3) in what protonation state they are bound in the different oxidation states Si (i = 0, 1, 2, 3, 4) of the OEC. By employing 17O hyperfine sublevel correlation (HYSCORE) spectroscopy we recently demonstrated that in the S2 state there is only one (type of) Mn-bound oxygen that is water exchangeable. We therefore tentatively identified this oxygen as one substrate ‘water’ molecule, and on the basis of the finding that it has a hyperfine interaction of about 10 MHz with the electron spin of the Mn4OxCa cluster, we suggest that it is bound as a Mn–O–Mn bridge within a bis-μ2 oxo-bridged unit (Su et al. in J Am Chem Soc 130:786–787, 2008). Employing pulse electron paramagnetic resonance, 1H/2H Mims electron-nuclear double resonance and 2H-HYSCORE spectroscopies together with 1H/2H-exchange here, we test this hypothesis by probing the protonation state of this exchangeable oxygen. We conclude that this oxygen is fully deprotonated. This result is discussed in the light of earlier reports in the literature
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