Expression of the 70 kDa Heat shock protein family in Alpine freshwater chironomids (Diptera, Chironomidae) under natural conditions.

Chironomidae represent up to 100% of the fauna of Alpine streams. Because they survive stress conditions such as extremely low temperature (annual mean < 4°C), these organisms represent a good organism model to analyze the relationship between adaptations to cold and expression of stress proteins such as the 70 kDa Heat shock protein family. Fourth instar larvae of ten species of cold-stenothermal chironomids (Pseudodiamesa branickii, Diamesa latitarsis, Diamesa laticauda, Diamesa cinerella, Diamesa insignipes, Diamesa zernyi, Diamesa vaillanti, Orthocladius (Orthocladius) frigidus, Orthocladius (Euorthocladius) thienemanni and Paratriclocladius nivalis) were collected in a glacier-fed stream in N.E. Italy at two stations (1300 and 2600 m a.s.l.) and in two seasons (summer 2005 and spring 2006). Immunodetection and quantification of therelative levels of Hsp70 family were performed via Western blotting. Significantly different levels of Hsp70 were detected among species. The highest amounts were recorded in P. nivalis and D. insignipes, the lowest in P. branickii. Within the genus Diamesa, lower levels of Hsp70 were observed in the most cold stenothermal species than in the less cold stenothermal ones. These differences are explained by different autoecology. The results provide information on biochemical strategies of alpine midges to face cold temperatures under natural conditions and new insights into their possible response to global warming

Nature, Source and Function of Pigments in Tardigrades: In Vivo Raman Imaging of Carotenoids in Echiniscus blumi

Tardigrades are microscopic aquatic animals with remarkable abilities to withstand harsh physical conditions such as dehydration or exposure to harmful highly energetic radiation. The mechanisms responsible for such robustness are presently little known, but protection against oxidative stresses is thought to play a role. Despite the fact that many tardigrade species are variously pigmented, scarce information is available about this characteristic. By applying Raman micro-spectroscopy on living specimens, pigments in the tardigrade Echiniscus blumi are identified as carotenoids, and their distribution within the animal body is visualized. The dietary origin of these pigments is demonstrated, as well as their presence in the eggs and in eye-spots of these animals, together with their absence in the outer layer of the animal (i.e., cuticle and epidermis). Using in-vivo semi-quantitative Raman micro-spectroscopy, a decrease in carotenoid content is detected after inducing oxidative stress, demonstrating that this approach can be used for studying the role of carotenoids in oxidative stress-related processes in tardigrades. This approach could be thus used in further investigations to test several hypotheses concerning the function of these carotenoids in tardigrades as photo-protective pigments against ionizing radiations or as antioxidants defending these organisms against the oxidative stress occurring during desiccation processes

Stress response of a boreo-alpine species of tardigrade, Borealibius zetlandicus (Eutardigrada, Hypsibiidae)

Invertebrates living in extreme environments as well as those living under unpredictable habitat conditions must be able to survive severe environmental stresses bound to their habitats. Tardigrades represent a good animal model to analyze responses evolved by organisms to overcome extreme environmental stresses or to colonize extreme environments because they respond to desiccation or freezing in their habitats by entering cryptobiosis. The responses to environmental stresses have been evaluated almost exclusively in terrestrial tardigrades, while very little is known about the ability of limnic species to tolerate those stresses. This study evaluates the responses of the limnic boreo-alpine species Borealibius zetlandicus, under lab conditions, to stresses imposed by desiccation and temperature variation (freezing and heating). Our results indicate that active specimens are able to freeze, confirming the cryobiotic ability of this species. There is a negative correlation between survival and cooling rates. In contrast, no specimens of B. zetlandicus are able to survive desiccation. With regard to thermal tolerance, the animals show a high ability to resist heat-shock (LT50 = 33.0 0.5°C) for a short time. This wide tolerance to different environmental parameters could be the reason for the wide distribution of the species. Due to the disjunct distribution of the species and to the presence of cryptic tardigrade species that could have different ecological and physiological responses, we decided to characterize the population studied from a molecular point of view by investigating its COI mtDNA sequences

Asymmetric correlation matrices: an analysis of financial data

We analyze the spectral properties of correlation matrices between distinct statistical systems. Such matrices are intrinsically non symmetric, and lend themselves to extend the spectral analyses usually performed on standard Pearson correlation matrices to the realm of complex eigenvalues. We employ some recent random matrix theory results on the average eigenvalue density of this type of matrices to distinguish between noise and non trivial correlation structures, and we focus on financial data as a case study. Namely, we employ daily prices of stocks belonging to the American and British stock exchanges, and look for the emergence of correlations between two such markets in the eigenvalue spectrum of their non symmetric correlation matrix. We find several non trivial results, also when considering time-lagged correlations over short lags, and we corroborate our findings by additionally studying the asymmetric correlation matrix of the principal components of our datasets.Comment: Revised version; 11 pages, 13 figure

ACTA OTORHINOLARYNGOLOGICA ITALICA

La malattia MYH9-correlata è una rara sindrome genetica caratterizzata da piastrinopenia congenita associata al rischio di sviluppare, durante linfanzia o letà adulta, ipoacusia neurosensoriale, nefropatia e cataratta presenile ad andamento evolutivo. Furono inclusi in uno studio retrospettivo tutti i casi con sordità da severa a profonda arruolati consecutivamente nel Registro Italiano dei pazienti affetti da malattia MYH9-correlata. La popolazione esaminata coinvolse 147 pazienti Italiani con malattia MYH9-correlata: lipoacusia fu identificata nel 52% dei casi e solo 4 pazienti (6%) presentarono un quadro di sordità da severa a profonda alletà media di 33 anni. In tutti i 4 pazienti, la sordità fu associata ad un lieve sanguinamento spontaneo e in 3 pazienti fu accompagnata da un coinvolgimento renale. Limpianto cocleare fu eseguito in 3 casi, con beneficio, in assenza di complicanze maggiori. La diagnosi di malattia MYH9-correlata fu eseguita circa 28 anni dopo la prima manifestazione clinica della malattia che non fu mai sospettata da un otorinolaringoiatra. Saranno discussi gli aspetti clinici e diagnostici di 4 pazienti con sordità da severa a profonda affetti da malattia MYH)-correlata, focalizzando anche le implicazioni terapeutiche

Studio della meiofauna nei pressi di un rigassificatore offshore

We report herein an investigation of spatial and temporal variations of meiofauna around an offshore regasification terminal located about 22 km offshore the coast of Livorno and Pisa (Ligurian Sea). Samples were collected in 12 sites located at three different distances from the plant. A total of six surveys were carried out, starting before the installation of the terminal. The investigation revealed the presence of 29 major taxa, with total meiofauna average densities ranging from 69 to 360 ind./10 cm2. The meiobenthic community varied significantly over years, irrespective to the distance from the terminal. No significant spatial variations of meiofauna around the regasification terminal were detected

Phospholipase C-eta enzymes as putative protein kinase C and Ca2+ signalling components in neuronal and neuroendocrine tissues

Phosphoinositol-specific phospholipase C enzymes (PLCs) are central to inositol lipid signalling pathways, facilitating intracellular Ca2+ release and protein kinase C activation. A sixth class of phosphoinositol-specific PLC with a novel domain structure, PLC-eta (PLCeta) has recently been discovered in mammals. Recent research, reviewed here, shows that this class consists of two enzymes, PLCeta1 and PLCeta2. Both enzymes hydrolyze phosphatidylinositol 4,5-bisphosphate and are more sensitive to Ca2+ than other PLC isozymes and are likely to mediate G-protein-coupled receptor (GPCR) signalling pathways. Both enzymes are expressed in neuron-enriched regions, being abundant in the brain. We demonstrate that they are also expressed in neuroendocrine cell lines. PLCeta enzymes therefore represent novel proteins influencing intracellular Ca2+ dynamics and protein kinase C activation in the brain and neuroendocrine systems as putative mediation of GPCR regulation

Determination of the b quark mass at the M_Z scale with the DELPHI detector at LEP

An experimental study of the normalized three-jet rate of b quark events with respect to light quarks events (light= \ell \equiv u,d,s) has been performed using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are found to agree with theoretical predictions treating mass corrections at next-to-leading order. Measurements of the b quark mass have also been performed for both the b pole mass: M_b and the b running mass: m_b(M_Z). Data are found to be better described when using the running mass. The measurement yields: m_b(M_Z) = 2.85 +/- 0.18 (stat) +/- 0.13 (exp) +/- 0.19 (had) +/- 0.12 (theo) GeV/c^2 for the CAMBRIDGE algorithm. This result is the most precise measurement of the b mass derived from a high energy process. When compared to other b mass determinations by experiments at lower energy scales, this value agrees with the prediction of Quantum Chromodynamics for the energy evolution of the running mass. The mass measurement is equivalent to a test of the flavour independence of the strong coupling constant with an accuracy of 7 permil.Comment: 24 pages, 10 figures, Accepted by Eur. Phys. J.