1,102 research outputs found
The submarine hydrothermal system of Panarea (Southern Italy): biogeochemical processes at the thermal fluids - sea bottom interface
Among the submarine hydrothermal systems located offshore the volcanic archipelago of the
Aeolian Islands (Southern Italy), the most active is located off the coasts of Panarea island. Thermal
waters, gases and sulfur deposits coexist at the sea bottom where hydrothermal fluids are released
from both shallow and deep vents. The chemical and isotopic composition of the fluid phase shows
the presence of a significant magmatic component and the physico-chemical conditions of the
geothermal reservoir allow the release of reduced chemical species that are microbially mediated
towards the production of organic carbon as a form of biochemical energy. Microorganisms
inhabiting this environment possess nutritional requirements and overall metabolic pathways ideally
suited to such ecosystem that represents a clear example of the close connection between geosphere
and biosphere. Microscopic examination of the white mat attached to rock surfaces showed the
presence of Thiothrix-like filamentous bacteria. Moderately thermophilic heterotrophic isolates
were identified as strains of the genus Bacillus. Although the hydrothermal system of Panarea has
to be considered a “shallow” system, it shows many characteristics that make it similar to the
“deep” oceanic systems, giving a unique opportunity for improving our knowledge on such an
unexplored world by working at this easily accessible site
1961–1990 monthly high-resolution solar radiation climatologies for Italy
Abstract. We present a methodology for estimating solar radiation climatologies from a sparse network of global radiation and/or sunshine duration records: it allows to obtain high-resolution grids of monthly normal values for global radiation (and for the direct and diffuse components), atmospheric turbidity, and surface absorbed radiation. We discuss the application of the methodology to a preliminary version of an Italian global radiation and sunshine duration data set, which completion is still in progress and present the resulting 1961–1990 monthly radiation climatologies
Extreme summer temperatures in Western Europe
Abstract. We discuss the evolution of summer temperature extremes over Western Europe during 1961–2004 in the context of current climate warming. Using a parametric approach, we investigate the role of properties and changes in probability density functions of daily temperatures in modifying the frequency of severe, isolated events. In this perspective, the recent intensification of extremely warm events over Europe turns out to be well consistent with a pure, nonuniform shift of mean values, with no room for conjectures about increasing temperature variability
Variability of orographic enhancement of precipitation in the Alpine region
Climate change impacts are non uniformly distributed over the globe. Mountains have a peculiar response to large scale variations, documented by elevation gradients of surface temperature increase observed over many mountain ranges in the last decades. Significant changes of precipitation are expected in the changing climate and orographic effects are important in determining the amount of rainfall at a given location. It thus becomes particularly important to understand how orographic precipitation responds to global warming and to anthropogenic forcing. Here, using a large rain gauge dataset over the European Alpine region, we show that the distribution of annual precipitation among the lowlands and the mountains has varied over time, with an increase of the precipitation at the high elevations compared to the low elevations starting in the mid 20 century and peaking in the 1980s. The simultaneous increase and peak of anthropogenic aerosol load is discussed as a possible source for this interdecadal change. These results provide new insights to further our understanding and improve predictions of anthropic effects on mountain precipitations, which are fundamental for water security and management
Characterisation of the global transcriptional response to heat shock and the impact of individual genetic variation
Abstract Background The heat shock transcriptional response is essential to effective cellular function under stress. This is a highly heritable trait but the nature and extent of inter-individual variation in heat shock response remains unresolved. Methods We determined global transcription profiles of the heat shock response for a panel of lymphoblastoid cell lines established from 60 founder individuals in the Yoruba HapMap population. We explore the observed differentially expressed gene sets following heat shock, establishing functional annotations, underlying networks and nodal genes involving heat shock factor 1 recruitment. We define a multivariate phenotype for the global transcriptional response to heat shock using partial least squares regression and map this quantitative trait to associated genetic variation in search of the major genomic modulators. Results A comprehensive dataset of differentially expressed genes following heat shock in humans is presented. We identify nodal genes downstream of heat shock factor 1 in this gene set, notably involving ubiquitin C and small ubiquitin-like modifiers together with transcription factors. We dissect a multivariate phenotype for the global heat shock response which reveals distinct clustering of individuals in terms of variance of the heat shock response and involves differential expression of genes involved in DNA replication and cell division in some individuals. We find evidence of genetic associations for this multivariate response phenotype that involves trans effects modulating expression of genes following heat shock, including HSF1 and UBQLN1. Conclusion This study defines gene expression following heat shock for a cohort of individuals, establishing insights into the biology of the heat shock response and hypotheses for how variation in this may be modulated by underlying genetic diversity
Estimating local records for Northern and Central Italy from a sparse secular temperature network and from 1961–1990 climatologies
The paper presents monthly 30-arc-second-resolution Northern and Central Italy temperature climatologies and discusses the procedure we adopt to superimpose the information of temperature secular records onto these climatologies. The climatologies are obtained by means of a step-wise linear regression method which aims at determining the temperature dependence on geographical and morphological variables. Such a method is applied to a database of about 800 monthly 1961–1990 temperature normals. In the first regression (temperature vs. elevation) the recorded data are considered; the further regressions concern the residuals obtained after taking into account the effect of each variable, in order of importance. An estimated secular anomaly record can be obtained for each point of the climatology grid by means of a distance-weighted average of the temperature anomaly records of the stations surrounding the grid point
Delayed chronic intracranial subdural hematoma complicating resection of a tanycytic thoracic ependymoma
Background: To demonstrate that the diagnosis of an intracranial subdural hematoma should be considered for patients presenting with acute or delayed symptoms of intracranial pathology following resection of a spinal tumor. Case Description: We present a case of a 57-year-old woman found to have a chronic subdural hematoma 1 month following resection of a thoracic extramedullary ependymoma. Evacuation of the hematoma through a burr hole relieved the presenting symptoms and signs. Resolution of the hematoma was confirmed with a computed tomography (CT) scan. Conclusion: Headache and other symptoms not referable to spinal pathology should be regarded as a warning sign of an intracranial subdural hematoma, and a CT scan of the head should be obtained. The mechanism of the development of the hematoma may be related to the leakage of cerebrospinal fluid with subsequent intracranial hypotension leading to an expanding subdural space and hemorrhage
High‐resolution monthly precipitation climatologies over Norway (1981–2010): Joining numerical model data sets and in situ observations
The 1981-2010 monthly precipitation climatologies for Norway at 1 km resolution are presented. They are computed by an interpolation procedure (HCLIM+RK) combining the output from a numerical model with the in situ observations. Specifically, the regional climate model data set HCLIM-AROME, based on the dynamical downscaling of the global ERA-Interim reanalysis onto 2.5 km resolution, is considered together with 2009 rain-gauges located within the model domain. The precipitation climatologies are defined by superimposing the grid of 1981-2010 monthly normals from the numerical model and the kriging interpolation of station residuals. The combined approach aims at improving the quality of gridded climatologies and at providing reliable precipitation gradients also over those remote Norwegian regions not covered by observations, especially over the northernmost mountainous areas. The integration of rain-gauge data greatly reduces the original HCLIM-AROME biases. The HCLIM+RK errors obtained from the leave-one-out station validation turn out to be lower than those provided by two considered interpolation schemes based on observations only: a multi-linear local regression kriging (MLRK) and a local weighted linear regression (LWLR). As average over all months, the mean absolute (percentage) error is 10.0 mm (11%) for HCLIM+RK, and 11.4 (12%) and 11.6 mm (12%) for MLRK and LWLR, respectively. In addition, by comparing the results at both station and grid cell level, the accuracy of MLRK and LWLR is more sensitive to the spatial variability of station distribution over the domain and their interpolated fields are more affected by discontinuities and outliers, especially over those areas not covered by the rain-gauge network. The obtained HCLIM+RK climatologies clearly depict the main west-to-east gradient occurring from the orographic precipitation regime of the coast to the more continental climate of the inland and it allows to point out the features of the climatic subzones of Norway
Efficacy and use of benralizumab in patients with eosinophilic chronic rhinosinusitis
Abstract Chronic rhinosinusitis has a multifactorial etiology resulting from a dysfunctional interaction between various environmental factors and the host immune system. The patient of case report is affected by chronic rhinosinusitis with nasal polyps and a type 2 molecular pattern, has comorbid asthma and symptoms resistant to adequate medical and surgical therapy. The patient was treated with benralizumab, a mAb that binds IL-5Rα. The therapy resulted in a reduction in blood and tissue eosinophilia, but this was not associated with an improvement in the clinical and objective rhinological picture. Instead, at the lung level, there was a marked improvement in the control of severe asthma. Therefore, the patient was undergoing revision Full FESS in association with biological drug therapy. The patient showed an immediately improvement in the clinical and objective rhinological picture and this association allowed for control of the disease almost one year after surgery
Prebiotic synthesis of cysteine peptides that catalyze peptide ligation in neutral water
Peptide biosynthesis is performed by ribosomes and several other classes of enzymes, but a simple chemical synthesis may have created the first peptides at the origins of life. a-Aminonitriles—prebiotic a–amino acid precursors—are generally produced by Strecker reactions. However, cysteine’s aminothiol is incompatible with nitriles. Consequently, cysteine nitrile is not stable, and cysteine has been proposed to be a product of evolution, not prebiotic chemistry. We now report a high-yielding, prebiotic synthesis of cysteine peptides. Our biomimetic pathway converts serine to cysteine by nitrile-activated dehydroalanine synthesis. We also demonstrate that N-acylcysteines catalyze peptide ligation, directly coupling kinetically stable—but energy-rich—a-amidonitriles to proteinogenic amines. This rare example of selective and efficient organocatalysis in water implicates cysteine as both catalyst and precursor in prebiotic peptide synthesis
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