904 research outputs found
Assessment of a stochastic downscaling methodology in generating an ensemble of hourly future climate time series
This study extends a stochastic downscaling methodology to generation of an ensemble of hourly time series of meteorological variables that express possible future climate conditions at a point-scale. The stochastic downscaling uses general circulation model (GCM) realizations and an hourly weather generator, the Advanced WEather GENerator (AWE-GEN). Marginal distributions of factors of change are computed for several climate statistics using a Bayesian methodology that can weight GCM realizations based on the model relative performance with respect to a historical climate and a degree of disagreement in projecting future conditions. A Monte Carlo technique is used to sample the factors of change from their respective marginal distributions. As a comparison with traditional approaches, factors of change are also estimated by averaging GCM realizations. With either approach, the derived factors of change are applied to the climate statistics inferred from historical observations to re-evaluate parameters of the weather generator. The re-parameterized generator yields hourly time series of meteorological variables that can be considered to be representative of future climate conditions. In this study, the time series are generated in an ensemble mode to fully reflect the uncertainty of GCM projections, climate stochasticity, as well as uncertainties of the downscaling procedure. Applications of the methodology in reproducing future climate conditions for the periods of 2000-2009, 2046-2065 and 2081-2100, using the period of 1962-1992 as the historical baseline are discussed for the location of Firenze (Italy). The inferences of the methodology for the period of 2000-2009 are tested against observations to assess reliability of the stochastic downscaling procedure in reproducing statistics of meteorological variables at different time scale
Legumes for Organic Cropping Systems
A field experiment which focuses on the yield performance of both durum wheat and sunflower included in a twoyear rotation between wheat/subterranean clover and sunflower was carried out in an organic farm in Central Italy. Three factors were included in the experiment according to a factorial design: a) two different previous crop sequences (four years of alfalfa, four years of annual crops); b) three fertilization levels (without and with animal manure incorporated at 15 or 40 cm depth); c) three durum wheat genotypes (Appulo, Arcangelo and Daunia cvs). The results obtained show that a previous alfalfa meadow allows the succeeding crops (wheat and sunflower) to achieve an appropriate and stable grain yield (about 4 and 3 t ha-1, respectively) even without organic manure for two consecutive cycles. When the durum wheat follows an annual crop sequence, grain yield appears unstable and the different levels of organic fertilizer determine a negative effect in the first cycle and a positive effect in the second cycle. The reseeding capability of sunflower was reduced by animal manure treatments and, consequently, the subclover biomass and its nitrogen content were generally lower in fertilized plots. Anyway, subclover biomass, which was ploughed in after reseeding as a green manure for sunflower, proved to be effective in stabilizing sunflower grain yield, especially in plots without any organic fertilization
Dr. Favalli, et al. reply
We thank Dr. So, et al1 for the interest in our letter2 and for sharing the results about the coronavirus disease 2019 (COVID-19) in patients with systemic lupus erythematosus (SLE) in Hong Kong1 We agree that the quantification of the risk of infection with severe acute respiratory coronaviruses-2 (SARS-CoV-2) in patients with SLE is a major concern
Alternative Cropping Systems with Self Reseeding Annual Legumes in a Mediterranean Environment
Self-reseeding winter annual legumes (subclover and snail medic) have the potential to induce a significant shift towards a less energy-intensive and more environmentally friendly management in the modern and specialized cereal cropping systems. Nevertheless their use is practically unknown in mixed stands with winter cereals, where they can contribute to supply nitrogen and to reduce herbicides input. We conceived an alternative cropping system where an annual legume performs, respectively, as living mulch in a winter cereal (winter wheat), as a cover crop after reseeding and as dry mulch for the succeeding summer cereal (corn). Trials carried out at the Tuscia University (Central Italy) in the period 1995-1997 showed that almost all the tested legumes cultivars were able both to grow sufficiently as a living mulch in the wheat and to provide a good re-establishment and an abundant mulch after the wheat harvest for the next corn. Trifolium yanninicum cv Trikkala and Trifolium subterraneum cvs Karridale and Mount Barker ranked first in reseeding capacity (up to 400 seedlings m-2) and mulch production (up to 5 t ha-1). No difference in grain yield between wheat with a living mulch and wheat in pure stand was found when legumes, such as Trifolium yanninicum cvs Trikkala and Larisa, Trifolium brachycalycinum cv Clare, Trifolium subterraneum cv Nungarin and Medicago scutellata cv Kelson, were grown in binary mixture with wheat. The aboveground biomass production of the succeeding irrigated corn crop was largely dependent on the amount of legume dry mulch left upon the ground
Water Values: Participatory Water Ecosystem Services Assessment in the Arno River Basin, Italy
Habitat Patch Diversity Evaluation for Sustainability: a Case Study of a Rural Area in Central Italy
Landscape analysis is regarded as a new tool for monitoring and judging land use patterns in terms of sustainability of human activity systems at local level. A case study of evaluation for sustainability based on habitat patch diversity in an ecoregion of Central Italy is presented. In this region, ongoing land use patterns reflect both historical adaptation to local environmental constraints and positive, social-oriented management. More protective land use patterns are mostly widespread in fragile physiographic conditions like those of the mountain areas, where woodland, shrub, and grassland patches are larger and cover more than 90% of the land. This situation is regarded as a positive outcome of the traditional public ownership regime, because public lands amount to more than 70% in the mountain areas. The hilly areas, where public property drops to 28%, presents landscape metrics showing a well balanced situation between agricultural land use and protective native woods and grasslands, which provides a fine-grained and harmonious Mediterranean landscape. In the low-land areas, with anthropic pressure and more favourable conditions for crop productivity, there is much more agricultural land, even if some mitigation in terms of biodiversity maintenance is offered by the presence of hedgerow ecotones. In these areas, landscape analysis is not able to supply meaningful information about cropping system design and practices which can maintain a sustainable level of soil fertility and quality of natural resources and processes, and further analysis at cropping system level should be carried out
A review of water-energy-food-ecosystems Nexus research in the Mediterranean: evolution, gaps and applications
The water-energy-food-ecosystems (WEFE) Nexus has gained recognition as an innovative approach for analysing the interconnectedness of global resource systems and achieving sustainability goals. In the Mediterranean, where water scarcity, climate change, and ecosystem degradation pose significant challenges, implementing an integrated WEFE Nexus approach is crucial. We conducted a comprehensive review of scientific literature through the lenses of Nexus ‘ideas’, ‘relationship’ and ‘practices’. A total of 142 research articles were selected and characterized in terms of WEFE interlinkages being investigated, explored topics, methods and scales of analysis, and contexts of operationalization. We found that water-energy interdependences dominate WEFE Nexus research in the Mediterranean, driven by the large presence of energy-intensive water abstraction and distribution systems to meet drinking and irrigation water demands. At the same time, the expansion of the Nexus approach to additional components is only partial, mostly focusing on assessing impacts on the physical environment and climate, without capturing feedback dynamics. Geographically, Nexus research in the Mediterranean is primarily conducted in isolated case studies, with few large scale assessments developed at the entire Mediterranean scale, and with some countries not yet represented, in particular the Western Balkans. Although WEFE Nexus research in the Mediterranean is recognizing the importance of transdisciplinarity moving beyond biophysical assessments to encompass societal and governance dynamics, further research is needed on understanding the economic implications of WEFE Nexus interactions. To advance Nexus implementation in the region, sustainable technology, and natural resources management, which are key fields of WEFE Nexus research operationalization, would benefit from harmonization in their design objectives. This would enable a more comprehensive and coherent approach towards achieving water, food, and energy security while preserving the environment in the Mediterranean region
OPA1-related auditory neuropathy: site of lesion and outcome of cochlear implantation.
Hearing impairment is the second most prevalent clinical feature after optic atrophy in Dominant Optic Atrophy associated with mutations in the OPA1 gene. In this study we characterized the hearing dysfunction in OPA1-linked disorders and provided effective rehabilitative options to improve speech perception.
We studied two groups of OPA1 subjects, one comprising 11 patients (7 males; age range 13-79 years) carrying OPA1 mutations inducing haploinsufficiency, the other, 10 subjects (3 males; age range 5-58 years) carrying OPA1 missense mutations. Both groups underwent audiometric assessment with pure tone and speech perception evaluation, and otoacoustic emissions and auditory brainstem response recording. Cochlear potentials were recorded through transtympanic electrocochleography from the group of patients harboring OPA1 missense mutations and were compared to recordings obtained from 20 normally-hearing controls and from 19 subjects with cochlear hearing loss. Eight patients carrying OPA1 missense mutations underwent cochlear implantation. Speech perception measures and electrically-evoked auditory nerve and brainstem responses were obtained after one year of cochlear implant use.
Nine out of 11 patients carrying OPA1 mutations inducing haploinsufficiency had normal hearing function. In contrast, all but one subject harboring OPA1 missense mutations displayed impaired speech perception, abnormal brainstem responses and presence of otoacoustic emissions consistent with auditory neuropathy. In electrocochleography recordings, cochlear microphonic had enhanced amplitudes while summating potential showed normal latency and peak amplitude consistent with preservation of both outer and inner hair cell activities. After cancelling the cochlear microphonic, the synchronized neural response seen in both normally-hearing controls and subjects with cochlear hearing loss was replaced by a prolonged, low-amplitude negative potential that decreased in both amplitude and duration during rapid stimulation consistent with neural generation. The use of cochlear implant improved speech perception in all but one patient. Brainstem potentials were recorded in response to electrical stimulation in five subjects out of six, whereas no compound action potential was evoked from the auditory nerve through the cochlear implant.
These findings indicate that underlying the hearing impairment in patients carrying OPA1 missense mutations is a disordered synchrony in auditory nerve fiber activity resulting from neural degeneration affecting the terminal dendrites. Cochlear implantation improves speech perception and synchronous activation of auditory pathways by by-passing the site of lesion
Finite Elements Analysis of an Electrochemical Coating Process of an Irregularly Shaped Cathode with COMSOL Multiphysics(R)
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