730 research outputs found
Assessment of alternative land management practices using hydrological simulation and a decision support tool: Arborea agricultural region, Sardinia
Quantifying the impact of land use on water supply and quality is a primary focus of environmental management. In this work we apply a semidistributed hydrological model (SWAT) to predict the impact of different land management practices on water and agricultural chemical yield over a long period of time for a study site situated in the Arborea region of central Sardinia, Italy. The physical processes associated with water movement, crop growth, and nutrient cycling are directly modeled by SWAT. The model simulations are used to identify indicators that reflect critical processes related to the integrity and sustainability of the ecosystem. Specifically we focus on stream quality and quantity indicators associated with anthropogenic and natural sources of pollution. A multicriteria decision support system is then used to develop the analysis matrix where water quality and quantity indicators for the rivers, lagoons, and soil are combined with socio-economic variables. The DSS is used to assess four options involving alternative watersheds designated for intensive agriculture and dairy farming and the use or not of treated wastewater for irrigation. Our analysis suggests that of the four options, the most widely acceptable consists in the transfer of intensive agricultural practices to the larger watershed, which is less vulnerable, in tandem with wastewater reuse, which rates highly due to water scarcity in this region of the Mediterranean. More generally, the work demonstrates how both qualitative and quantitative methods and information can assist decision making in complex settings
Data reconstruction and homogenization for reducing uncertainties in high-resolution climate analysis in Alpine regions
Analysis of climatic series needs pre-processing
to attain spatial- and time-consistent homogeneity. The latter,
in high-resolution investigations, can rely on the strong
correlations among series, which in turn requires a strict
fulfilment of the quality standard in terms of completeness.
Fifty-nine daily precipitation and temperature series of
50 years from Trentino, northern Italy, were pre-processed
for climatic analysis. This study describes: (1) the preliminary
gap-filling protocol for daily series, based on geostatistical
correlations on both horizontal and vertical domains;
(2) an algorithm to reduce inhomogeneity owing to the
systematic snowfall underestimation of rain gauges; and
(3) the processing protocol to take into account any source
of undocumented inhomogeneity in series. This was performed
by application of the t test and F-test of R code
RHtestV2. This pre-processing shows straightforward
results; correction of snowfall measurements re-evaluates
attribution of patterns of altitudinal trends in time trends;
homogenization increases the strength of the climatic signal
and reduces the scattering of time trends, assessed over a few decades, of a factor of 2
Reproductive patterns in deep versus shallow populations of the precious Mediterranean gorgonian Corallium rubrum ( Linnaeus, 1758) ( Sardinia, Central-Western Mediterranean)
This study quanti es the main reproductive features of the long-lived red coral Corallium rubrum, an octocoral endemic to the Mediterranean Sea and neighbouring Atlantic areas and one of the most valuable of all marine species, at different depths (38-40 m versus 96-115 m) in the north-western Sardinian waters (Central-Western Mediterranean Sea). Different population structures were observed with shallow colonies smaller (in basal diameter and height) than deeper ones. Both populations were all gonochoric at polyp and colony level and fertile. The sex-ratio was balanced in the deep red corals while in the shallow ones it was signi cantly biased towards female. Deep and shallow colonies were found to have a synchronous female sexual products development in the two depth ranges investigated. C. rubrum produced large female sexual products in both depth intervals in relationship with its reproductive mode, con rming a long oogenic development. In contrast to reproductive timing, the volume occupied by female sexual products per polyp was different between the populations, being higher in the deep than in the shallow populations. C. rubrum exhibited a reproductive strategy characterized by a relative low number of female sexual products per polyp revealing signi cant differences among the two depth ranges analyzed with a lower mean value of sexual products in the shallow colonies (mean fecundity per polyp: 1.14) than in the deeper ones (mean fecundity per polyp: 2.09). These results indicate differences in reproductive parameters such as sexual products distribution and reproductive output (fecundity) which were observed between shallow and deep populations of C. rubrum, in particular within deep dwelling populations
Chemistry and clumpiness in planetary nebulae
We study the chemistry in the slow wind during the transition from AGB star
to pre-planetary nebula (PPN) and planetary nebula (PN). We show that there is
a very rich chemistry of degradation products created by photoprocessing,
driven by the gradually hardening radiation field of the central star. Most of
these products are, however, photodissociated during the PPN phase if the wind
is smooth. By contrast, if the wind is clumpy, possibly because of clumpiness
in the AGB atmosphere, then many of these degradation products survive into the
PN phase. Thus, chemistry may be used to infer the existence of clumpiness in
the AGB phase. We identify potential molecular tracers, and we note that, in
the case of clumpiness, large molecules may survive the transport from the
stellar atmosphere to the interstellar medium. We compare between our model
results with observations of three objects at differing evolutionary stages:
CRL618, NGC 7027 and the Helix nebula (NGC 7293).Comment: 7 pages, 4 figures, accepted for publication in MNRA
ENTRE CONTOS E CANTOS: A CONSTRUÇÃO DA MEMÓRIA COLETIVA DAS PRÁTICAS CULTURAIS EM REGÊNCIA AUGUSTA
Regência Augusta faz parte do município de Linhares. Trata-se de um pequeno vilarejo rodeado pela foz do Rio Doce e o mar. Em maior parte, a comunidade é descendente da miscigenação entre indígenas, negros e brancos, comumente chamados na região de nativo ou caboclo. Estes sujeitos estão intimamente ligados a duas práticas culturais locais: a pescaria e o Congo. O trabalho apresenta um estudo sobre as duas práticas culturais da vila, analisando, principalmente, a construção da memória coletiva por meio das lembranças dos moradores. Devido a caraterística da pesquisa, se fez necessário o uso da abordagem qualitativa, utilizando o meio social da vila como fonte direta de coleta de dados. A observação em campo possibilitou conhecer o dia a dia e as relações entre os sujeitos envolvidos na comunidade e as articulações orais que se constroem desses encontros. As etapas formuladas para pesquisa consistem em: levantamento bibliográfico; entrevistas em história oral temática com sujeitos envolvidos em práticas culturais na área do objeto de pesquisa e observações das ações cotidianas; e análise dos dados. A pesquisa se apoiou no referencial teórico dos autores que discutem o conceito de história e memória com Halbwachs (2003) e Le Goff (2013). Por se tratar de uma comunidade tradicional não se poderia deixar de abordar a questão cultural, deste modo as reflexões de Burke (2008) e Canclini (1983) são os suportes teóricos. Nas análises dos dados se considerou, também, as concepções de Geertz (1997) sobre a interpretação das culturas. Gramsci (1989) fundamenta o conceito de intelectuais orgânicos, identificações trabalhadas nas narrativas dos líderes comunitários da vila, e a formação\educação numa dimensão para vida prática, nos aspectos culturais e sociais da Banda de Congo Mirim. Em relação aos contadores/narradores da história, as teorias de Benjamin (1994) apoiaram as discussões. No levantamento de dados empíricos, que envolve a interrogação direta dos sujeitos participantes da comunidade de Regência Augusta cujo, as lembranças se pretenderam conhecer, utilizou-se do método da história oral temática( MEIHY, 2015) obtendo um total de 9 relatos orais. Nesse estudo, três apontamentos se mostraram expressivos: a memória coletiva que é construída a partir das lembranças em comum, as práticas culturais da pescaria do Congo e sua
relação com o rio\mar e a transmissão de conhecimentos populares por meio da contação e cantação de histórias.
Palavras-chave: Memória Coletiva. Práticas Culturais. Tradição oral
Experimental and numerical research activity on a packed bed TES system
This paper presents the results of experimental and numerical research activities on a packed bed sensible thermal energy storage (TES) system. The TES consists of a cylindrical steel tank filled with small alumina beads and crossed by air used as the heat transfer fluid. Experimental tests were carried out hile varying some operating parameters such as the mass flow rate, the inlet–outlet temperature thresholds and the aspect ratio (length over diameter). Numerical simulations were carried out using a one-dimensional model, specifically developed in the Matlab-Simulink environment and a 2D axisymmetric model based on the ANSYS-Fluent platform. Both models are based on a two-equation transient approach to calculate fluid and solid phase temperatures. Thermodynamic properties were considered to be temperature-dependent and, in the Computational Fluid Dynamics (CFD) model, variable porosity of the bed in the radial direction, thermal losses and the effective conductivity of the alumina beads were also considered. The simulation results of both models were compared to the experimental ones, showing good agreement. The one-dimensional model has the advantage of predicting the axial temperature distribution with a very low computational cost, but it does not allow calculation of the correct energy stored when the temperature distribution is strongly influenced by the wall. To overcome this problem a 2D CFD model was used in this work
A multidisciplinary diagnostic approach preliminary to the restoration of the country church "San Maurizio" located in Ittiri (SS), Italy
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An unusual finding of Sepietta oweniana (Cephalopoda: Sepiolidae) egg clutch
An unusual finding of Sepietta oweniana egg clutch at 544 m depth is described within an updating study of the reproductive aspects of the species in Sardinian waters. Egg species identity was determined by genetic analysis and morphological and biometrical data of the eggs, embryos and one newly hatched specimen are reported and discussed. Illustrations of the eggs, spermatophores and spermatangia by photographic material are also included. Data on bathymetric distribution and sexual maturity are reported and compared with data already available for the species in other geographical areas of distributio
Acquired factor V inhibitor in a context of sepsis and disseminated intravascular coagulation
International audienc
Pulmonary transit time as a marker of diastolic dysfunction in Takotsubo syndrome
AIM: To evaluate the pulmonary transit time (PTT) and its derived parameters using cardiac magnetic resonance imaging (CMRI) as markers of diastolic dysfunction in Takotsubo syndrome (TS) and its relationship with transthoracic echocardiography and CMRI parameters. MATERIALS AND METHODS: Twenty-two patients with TS, who exhibited diastolic dysfunction as assessed by transthoracic echocardiography, were enrolled retrospectively and the PTT, pulmonary transit time index (PTTI), and pulmonary blood volume index (PBVI) were evaluated using first-pass CMRI. PTT was calculated as the number of cardiac cycles required for a bolus of contrast agent to move from the right ventricle (RV) to the left ventricle (LV), whereas PTTI represents the PTT interval corrected for the heart rate. Finally, PBVI was calculated as the product of PTTI, and RV stroke volume indexed for body surface area. Normal references of PTT, PTTI, and PBVI were evaluated in a cohort of 20 age- and sex-matched healthy controls. RESULTS: Compared with healthy subjects, TS patients showed significantly higher PTT, PTTI, and PBVI (p=0.0001, p=0.0001, and p=0.002, respectively). Using multivariable logistic regression, PBVI provided the best differentiation between TS and controls (AUC 0.84). PBVI was significantly associated with the index of diastolic dysfunction and left atrial strain parameters. In addition, PBVI demonstrated a significant correlation with global T2 mapping (r=0,520, p=0,019). CONCLUSION: PTT and the derived parameters, as assessed using first-pass CMRI, are potential tools for assessing LV diastolic dysfunction in patients with TS
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