Biogeographic classification of the Caspian Sea

Like other inland seas, the Caspian Sea (CS) has been influenced by climate change and anthropogenic disturbance during recent decades, yet the scientific understanding of this water body remains poor. In this study, an eco-geographical classification of the CS based on physical information derived from space and in situ data is developed and tested against a set of biological observations. We used a two-step classification procedure, consisting of (i) a data reduction with self-organizing maps (SOMs) and (ii) a synthesis of the most relevant features into a reduced number of marine ecoregions using the hierarchical agglomerative clustering (HAC) method. From an initial set of 12 potential physical variables, 6 independent variables were selected for the classification algorithm, i.e., sea surface temperature (SST), bathymetry, sea ice, seasonal variation of sea surface salinity (DSSS), total suspended matter (TSM) and its seasonal variation (DTSM). The classification results reveal a robust separation between the northern and the middle/southern basins as well as a separation of the shallow nearshore waters from those offshore. The observed patterns in ecoregions can be attributed to differences in climate and geochemical factors such as distance from river, water depth and currents. A comparison of the annual and monthly mean Chl <i>a</i> concentrations between the different ecoregions shows significant differences (one-way ANOVA, <i>P</i> < 0.05). In particular, we found differences in phytoplankton phenology, with differences in the date of bloom initiation, its duration and amplitude between ecoregions. A first qualitative evaluation of differences in community composition based on recorded presence–absence patterns of 25 different species of plankton, fish and benthic invertebrate also confirms the relevance of the ecoregions as proxies for habitats with common biological characteristics

Overexpression of stathmin in breast carcinomas points out to highly proliferative tumours

We recently discovered that stathmin was overexpressed in a subgroup of human breast carcinomas. Stathmin is a cytosolic phosphoprotein proposed to act as a relay integrating diverse cell signalling pathways, notably during the control of cell growth and differentiation. It may also be considered as one of the key regulators of cell division for its ability to destabilize microtubules in a phosphorylation-dependent manner. To assess the significance of stathmin overexpression in breast cancer, we evaluated the correlation of stathmin expression, quantified by reverse transcription polymerase chain reaction, with several disease parameters in a large series of human primary breast cancer (n = 133), obtained in strictly followed up women, whose clinico-pathological data were fully available. In agreement with our preliminary survey, stathmin was found overexpressed in a subgroup of tumours (22%). In addition, overexpression was correlated to the loss of steroid receptors (oestrogen, P = 0.0006; progesterone, P = 0.008), and to the Scarff–Bloom–Richardson histopathological grade III (P = 0.002), this latter being ascribable to the mitotic index component (P = 0.02). Furthermore studies at the DNA level indicated that stathmin is overexpressed irrespective of its genomic status. Our findings raise important questions concerning the causes and consequences of stathmin overexpression, and the reasons of its inability to counteract cell proliferation in the overexpression group. © 2000 Cancer Research Campaig

Séminome Spermatocytaire: à Propos d’un Cas et Revue de La Littérature Spermatocytic Seminoma

Le séminome spermatocytaire est une tumeur rare, représentant moins de 2% des cancers du testicule, survenant essentiellement chez le sujet âgé. Nous rapportons une nouvelle observation d’un patient âgé de 48 ans. La tumeur se présentait comme une prolifération de cellules en nappescompactes, avec 3 types cellulaires, des cellules de petite taille, des cellules intermédiaires et des grandes cellules. Il n’a été retrouvé ni contingent sarcomateux, ni séminome classique. L’analyse en immun histochimie n’a retrouvé aucune expression des cellules tumorales pour les anticorpsclassiques testés, notamment l’Ac anti PLAP et les marqueurs lymphoïdes. Le séminome spermatocytaire doit être reconnu, car son évolution est très favorable et ne nécessite qu’une simple orchidectomie, en l’absence d’un exceptionnel contingent sarcomateux ou de métastase où une chimiothérapie s’impose

Synthesis, crystal structure, physical and catalytic oxidation studies of a new hybrid phosphate [(N2H5)2Co(HPO4)2]

A new one-dimensional coordination polymer [(N2H5)2Co(HPO4)2] was synthesized by slow evaporation method and characterized by means of single-crystal X-ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). Its catalytic activity was tested using UV–visible absorption measurements. The compound crystallizes in the monoclinic system (S.G: P21/c) with the cell parameters (Å, °): a = 5.3665(3), b = 11.1271(6), c = 7.7017(4), β = 104.843(4), V = 444.55(4) Å3 and Z = 2. The crystal structure, consisting of a linear chain, is made of rings of [CoN2O4] octahedra and [PO3(OH)] tetrahedra sharing vertices via oxygen atoms coordinated to cobalt centers. The rings are linked to chains running along [100] and form thereby polymeric chains that are connected by hydrogen bonds in a three-dimensional arrangement. The FTIR spectroscopy shows the expected bands of hydrazine and phosphate groups. The thermal behavior consists mainly of the loss of hydrazine moieties leading thus to the formation of anhydrous cobalt phosphate. The phosphate complex exhibits efficiency in catalytic oxidation and degradation of methylene blue dye. The ac magnetic susceptibility shows a peak indicating antiferromagnetic order with a Néel temperature of 5.5 K. Fitting the Curie-Weiss equation to the ac magnetic susceptibility above 50 K gives the average Curie-Weiss Constant to be −11.8 K

The evaluation of experimental data in fast range for n + 56

Iron is one of the five materials selected for evaluation within the pilot international evaluation project CIELO. Analysis of experimental data for n+56Fe reaction is the basis for constraining theoretical calculations and eventual creation of the evaluated file. The detail analysis was performed for inelastic cross sections of neutron induced reactions with 56Fe in the fast range up to 20 MeV where there are significant differences among the main evaluated libraries, mainly caused by the different inelastic scattering cross section measurements. Gamma-ray production cross sections provide a way to gain experimental information about the inelastic cross section. Large discrepancies between experimental data for the 847-keV gamma ray produced in the 56Fe(n,n1'γ) reaction were analyzed. In addition, experimental data for elastic scattering cross section between 9.41∼11 MeV were used to deduce the inelastic cross section from the unitarity constrain

Nodes of Ranvier and Paranodes in Chronic Acquired Neuropathies

Chronic acquired neuropathies of unknown origin are classified as chronic inflammatory demyelinating polyneuropathies (CIDP) and chronic idiopathic axonal polyneuropathies (CIAP). The diagnosis can be very difficult, although it has important therapeutic implications since CIDP can be improved by immunomodulating treatment. The aim of this study was to examine the possible abnormalities of nodal and paranodal regions in these two types of neuropathies. Longitudinal sections of superficial peroneal nerves were obtained from biopsy material from 12 patients with CIDP and 10 patients with CIAP and studied by immunofluorescence and in some cases electron microscopy. Electron microscopy revealed multiple alterations in the nodal and paranodal regions which predominated in Schwann cells in CIDP and in axons in CIAP. In CIDP paranodin/Caspr immunofluorescence was more widespread than in control nerves, extending along the axon in internodes where it appeared intense. Nodal channels Nav and KCNQ2 were less altered but were also detected in the internodes. In CIAP paranodes, paranodin labeling was irregular and/or decreased. To test the consequences of acquired primary Schwann cells alteration on axonal proteins, we used a mouse model based on induced deletion of the transcription factor Krox-20 gene. In the demyelinated sciatic nerves of these mice we observed alterations similar to those found in CIDP by immunofluorescence, and immunoblotting demonstrated increased levels of paranodin. Finally we examined whether the alterations in paranodin immunoreactivity could have a diagnosis value. In a sample of 16 biopsies, the study of paranodin immunofluorescence by blind evaluators led to correct diagnosis in 70±4% of the cases. This study characterizes for the first time the abnormalities of nodes of Ranvier in CIAP and CIDP, and the altered expression and distribution of nodal and paranodal proteins. Marked differences were observed between CIDP and CIAP and the alterations in paranodin immunofluorescence may be an interesting tool for their differential diagnosis

Brain architecture in the terrestrial hermit crab Coenobita clypeatus (Anomura, Coenobitidae), a crustacean with a good aerial sense of smell

<p>Abstract</p> <p>Background</p> <p>During the evolutionary radiation of Crustacea, several lineages in this taxon convergently succeeded in meeting the physiological challenges connected to establishing a fully terrestrial life style. These physiological adaptations include the need for sensory organs of terrestrial species to function in air rather than in water. Previous behavioral and neuroethological studies have provided solid evidence that the land hermit crabs (Coenobitidae, Anomura) are a group of crustaceans that have evolved a good sense of aerial olfaction during the conquest of land. We wanted to study the central olfactory processing areas in the brains of these organisms and to that end analyzed the brain of <it>Coenobita clypeatus </it>(Herbst, 1791; Anomura, Coenobitidae), a fully terrestrial tropical hermit crab, by immunohistochemistry against synaptic proteins, serotonin, FMRFamide-related peptides, and glutamine synthetase.</p> <p>Results</p> <p>The primary olfactory centers in this species dominate the brain and are composed of many elongate olfactory glomeruli. The secondary olfactory centers that receive an input from olfactory projection neurons are almost equally large as the olfactory lobes and are organized into parallel neuropil lamellae. The architecture of the optic neuropils and those areas associated with antenna two suggest that <it>C. clypeatus </it>has visual and mechanosensory skills that are comparable to those of marine Crustacea.</p> <p>Conclusion</p> <p>In parallel to previous behavioral findings of a good sense of aerial olfaction in C. clypeatus, our results indicate that in fact their central olfactory pathway is most prominent, indicating that olfaction is a major sensory modality that these brains process. Interestingly, the secondary olfactory neuropils of insects, the mushroom bodies, also display a layered structure (vertical and medial lobes), superficially similar to the lamellae in the secondary olfactory centers of <it>C. clypeatus</it>. More detailed analyses with additional markers will be necessary to explore the question if these similarities have evolved convergently with the establishment of superb aerial olfactory abilities or if this design goes back to a shared principle in the common ancestor of Crustacea and Hexapoda.</p