oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Search Results: 1 - 10 of 817 matches for " Leonel; Tiberti "
All listed articles are free for downloading (OA Articles)
Page 1 /817
Display every page Item
Widespread bacterial infection affecting Rana temporaria tadpoles in mountain areas
Rocco Tiberti
Acta Herpetologica , 2011,
Abstract: Periodic mass die-offs of Rana temporaria tadpole populations have occurred in the ponds of prealpine mountain areas of Brescia (northern Italy) since the early 2000s. The author reports some observational data and analytical results from three sites: tadpoles from mortality events had erythema, especially on the legs, suggestive of septicemia. Bacterial culture of these tadpoles revealed Aeromonas hydrophila and Aeromonas sobria, two organisms often associated with Red leg disease. Egg mass counts from 29 pastureland ponds did not revealed breeding activity declines over five years in the Monte Guglielmo area. Aeromonas hydrophila and Aeromonas sobria usually behave as opportunistic bacteria that can become pathogenic after suppression of the immune system by endogenous or exogenous stressors. Thus, a plurality of environmental factors may contribute to mortality events; some of them are discussed, including loss of high altitude breeding ponds resulting in overcrowding and poor water quality in remaining ponds and the presence of other pathogens.
Morphology and ecology of Daphnia middendorffiana, Fisher 1851 (Crustacea, Daphniidae) from four new populations in the Alps
Rocco TIBERTI
Journal of Limnology , 2011, DOI: 10.4081/jlimnol.2011.239
Abstract: Daphnia middendorffiana has an arctic, circumpolar distribution, with some isolated southerly populations restricted to mountainous areas, including the Alps. In this paper, new records of Daphnia middendorffiana on the Alps are reported. The species was regularly recorded in several samples collected from 2006 to 2009 in four high altitude lakes in the Gran Paradiso National Park (GPNP) during the ice free period. This is the third finding for the Alps and the described populations are the largest. Chemical and morphometric features of the lakes are provided, the morphology of the Daphnia middendorffiana from GPNP is described as well as some aspects concerning its ecology. The studied lakes are small, oligotrophic (total phosphorus ranged from 0 to 7 μg L-1) and well preserved from acidification risk (pH ranged from 6.45 to 8.14). D. middendorffiana is the largest zooplanktonic crustacean inhabiting the Alpine lakes in GPNP reaching 3.43 mm in length; the morphological analysis noted some differences within the studied populations; however there is a clear resemblance to the only Alpine population previously described (from Central Alps, Bognanco Valley, Lake Campo IV) and to the arctic populations. D. middendorffiana in GPNP lives at low density levels, reaching higher densities in late August and early September. No males have been found during the sample campaign confirming its ability to produce asexual viable diapauses eggs. This study confirms the attitude of this species for cold and oligotrophic waters and increases the current knowledge on the geographical distribution, morphology and ecology of this species in Alpine environments. The finding of D. middendordorffiana in the GPNP poses interesting issues concerning the phylogeography of Alpine Daphnia middendorffiana, as well as raising need for conservation efforts aimed at keeping the populations safe from several global and local threats, such as climate warming and the ecological impact of alien species.
First report of freshwater leech Helobdella stagnalis (Rhyncobdellida: Glossiphoniidae) as a parasite of an anuran amphibian
Rocco Tiberti,Augusto Gentilli
Acta Herpetologica , 2010,
Abstract: The authors describe the first case of parasitism on anuran amphibian, Rana temporaria, by the freshwater leech Helobdella stagnalis, in a mountainous area of northwestern Italy. The presence of skin abrasions and haemorrhages attributable to leech attack discards the hypothesis of a simple phoretic relationship between leech and frog.
Diabetes autoinmune del adulto en diabéticos tipo 2: frecuencia y características
Cabrera-Rode,Eduardo; Perich Amador,Pedro; Díaz Horta,Oscar; Molina Matos,Gisela; Suárez Fonseca,Leonel; Tiberti,Claudio; Arranz Calzado,Celeste; Licea Puig,Manuel; Puig Domingo,Manuel; de Leiva,Alberto; Di Mario,Umberto;
Revista Cubana de Endocrinolog?-a , 2001,
Abstract: this paper was aimed at knowing the frequency, clinico-biochemical, immunologic and genetic characteristics of autoimmune diabetes in adults (lada) in 1 000 type 2 diabetic patients aged 35 or over with different times of duration of diabetes. glycemia, anti-pancreatic islet cell antibodies (ica), anti-gad65 antibodies, anti-ica512bdc/ia2 antibodies, anti-microsomal thyroid antibodies (amt), anti-gastric parietal antibodies (agp), antinuclear antibodies (an), microalbuminuria and peptide c during fasting were determined. these patients were surveyed and some clinical characteristics were registered. they were divided into 2 groups according to the presence of ica. all the type 2 + diabetics for anti-islet cell autoantibodies (ica and/or antigad65) were identified as lada. 3.4 % of type 2 ica + were detected. 22.0 % of type 2 ica - diabetics had anti-gad65 antibodies. it was found that type 2 ica + diabetics were younger, that their diabetes was shorter, that they had lower bmi, reduced levels of fasting peptide c, less dm2 history family (parents), lower values of diastolic and systolic arterial pressure, higher presence of anti-gad65 antibodies, amt and agp in comparison with type 2 ica - diabetics. it was observed that type 2 ica+ diabetics (lada) have specific characteristics that make them similar to type 1 diabetics, which would lead to important variations in their treatment and evolution as regards type 2 ica - diabetics. among the cuban type 2 diabetics it was detected a low frequency of ica and a high frequency of gad, which were different to those found in the caucasian populations. the anti-gad65 antibodies were higher than ica to detect lada. the clinical and immunological characteristics of these patients show the slow progression of the autoimmune destruction of b-cells with therapeutic implications.
Mechanisms of Intramolecular Communication in a Hyperthermophilic Acylaminoacyl Peptidase: A Molecular Dynamics Investigation
Elena Papaleo, Giulia Renzetti, Matteo Tiberti
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0035686
Abstract: Protein dynamics and the underlying networks of intramolecular interactions and communicating residues within the three-dimensional (3D) structure are known to influence protein function and stability, as well as to modulate conformational changes and allostery. Acylaminoacyl peptidase (AAP) subfamily of enzymes belongs to a unique class of serine proteases, the prolyl oligopeptidase (POP) family, which has not been thoroughly investigated yet. POPs have a characteristic multidomain three-dimensional architecture with the active site at the interface of the C-terminal catalytic domain and a β-propeller domain, whose N-terminal region acts as a bridge to the hydrolase domain. In the present contribution, protein dynamics signatures of a hyperthermophilic acylaminoacyl peptidase (AAP) of the prolyl oligopeptidase (POP) family, as well as of a deletion variant and alanine mutants (I12A, V13A, V16A, L19A, I20A) are reported. In particular, we aimed at identifying crucial residues for long range communications to the catalytic site or promoting the conformational changes to switch from closed to open ApAAP conformations. Our investigation shows that the N-terminal α1-helix mediates structural intramolecular communication to the catalytic site, concurring to the maintenance of a proper functional architecture of the catalytic triad. Main determinants of the effects induced by α1-helix are a subset of hydrophobic residues (V16, L19 and I20). Moreover, a subset of residues characterized by relevant interaction networks or coupled motions have been identified, which are likely to modulate the conformational properties at the interdomain interface.
Focus on coal power station installations and population health
Valenti,Marco; Masedu,Francesco; Tiberti,Sergio;
Annali dell'Istituto Superiore di Sanità , 2011, DOI: 10.4415/ANN_11_03_11
Abstract: damage to health associated with emissions from coal power stations can vary greatly from one location to another depending on the size of the plant, location and the characteristics of the population. population-based studies conducted by independent groups in different locations around the world show effects on health in populations at higher risk, but failed to definitely demonstrate direct effects on morbidity and mortality, to be exclusively attributed to the presence of active power stations. however, evidence on the role of micropollutants from power station activities suggests that a complete and thorough analysis should be made on the environmental cycle. therefore danger should in any case be assessed as carefully as possible while assuming, at most, that all micropollutants may come into direct contact with man through the various potential pathways throughout their entire lifetime, regardless of the factors that reduce their presence.
Geomorphology and hydrochemistry of 12 Alpine lakes in the Gran Paradiso National Park, Italy
Rocco TIBERTI,Gabriele A. TARTARI,Aldo MARCHETTO
Journal of Limnology , 2010, DOI: 10.4081/jlimnol.2010.242
Abstract: Twelve Alpine lakes located in the Gran Paradiso National Park, in the western Italian Alps, were sampled during the ice free period in 2008 and analysed for the main morphological, chemical and physical variables in relation to the characteristics of their watershed, with the aim to create a reference database for present and future ecological studies and to support conservation politics with scientific data. The results highlighted that weathering process and direct precipitation input are the main factors determining the hydrochemistry of the studied lakes; moreover the morphological characteristics highly affects the physical properties of the lakes starting from stratification process. The acidification status, the atmospheric input of N compounds and the supply of nutrients were considered in detail. The studied lakes seem to be well preserved by acidification risk. Comparing data from Gran Paradiso National Park with data from European mountain regions ranging in N deposition rates, allows to consider long range anthropogenic impact: the detection of relative low Total Nitrogen (TN) concentration is not necessarily a synonym of a soft impact of long range pollutants, being the final nitrogen concentration dependent from retention process, closely related to catchment characteristics, besides N deposition rates; moreover the dominance of Inorganic Nitrogen (IN) on Organic Nitrogen (ON) highlights that the lakes are interested by N deposition and probably by long range transport of pollutants produced in the urbanized area surrounding the massif. However the Gran Paradiso National Park area is by far less affected by atmospheric pollutants than other Alpine regions, as the Central Alps. Total Phosphorus (TP) concentration in Gran Paradiso lakes (1-13 μg L-1, mean level = 4 μg L-1) is an index of oligotrophic and ultraoligotrophic conditions and according to Redfield's ratio phosphorus is mainly the phytoplankton growth limiting element, assuming a key role in biological processes and food-web dynamics; the high TN:TP ratio values detected in the studied lakes reflects the low N retention capacity of alpine sparse vegetation by comparison with prairies or forests.
Bio-sociodiversidade: preserva??o e mercado
Leonel, Mauro;
Estudos Avan?ados , 2000, DOI: 10.1590/S0103-40142000000100019
Abstract: several studies have been revealing prospects of capitalizing on native knowledge and traditional cultures in order to launch new market products, such as drugs, cosmetics, new materials, foods, seeds and preservers. the market has adopted the practice of appropriating such cultural goods, which after slight adaptation are registered and turned out as patent-protected products and sold even to the countries where that knowledge was first developed, south of the equator as a rule. vis-à-vis the social and evironmental degradation scale, as is the case of the amazon area, a new optimism has risen: the hope that financial results from such products could benefit the native peoples, through the alteration of international legislation and the association of producers cooperatives with transnational companies. the market, the main opponent of bio- and sociodiversity, would thus be invited - both producers and consumers - to support the maintenance of the standing forest and cultural difference, for example, by means of origin certificates. nevertheless, many are the obstacles preventing the native peoples from making a breakthrough either in the market or in the patent registration international systems vis-à-vis the capital and technology concentration logic.
Análise da forma e tamanho de granulos de amidos de diferentes fontes botanicas
Leonel, Magali;
Ciência e Tecnologia de Alimentos , 2007, DOI: 10.1590/S0101-20612007000300024
Abstract: an analysis was made of the shape and size of starch grains from different botanical species, aiming to improve the potential applicability of these species as starch raw materials. the starches were obtained from the processing of tubers in a pilot extraction plant. the shape of the starch grains was analyzed by scanning electron microscopy (sem), to which end the samples were mounted on sem stubs and coated with gold. the size of the starch grains was determined by optical microscopy, for which the samples were diluted in a water and glycerin solution. the sizes of 500 grains of each botanical species were measured to determine the largest and smallest diameters and the difference between diameters. the results revealed different starch grain shapes and sizes, with xanthosoma sp showing the smallest (12.87 μm) and canna edulis the largest grain size (56.61 μm). the yam bean tuber pachyrhizus ahipa showed the most uniform starch grain distribution.
GEST O DE CUSTOS: UMA ABORDAGEM INTEGRADA ENTRE CONTABILIDADE, ENGENHARIA E ADMINISTRA O
Leonel Mazzalli
Gest?o & Regionalidade , 2009,
Abstract:
Page 1 /817
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.