Active removal of inorganic phosphate from cerebrospinal fluid by the choroid plexus

The P-i concentration of mammalian cerebrospinal fluid (CSF) is about one-half that of plasma, a phenomenon also shown here in the spiny dogfish, Squalus acanthias. The objective of the present study was to characterize the possible role of the choroid plexus (CP) in determining CSF P-i concentration. The large sheet-like fourth CP of the shark was mounted in Ussing chambers where unidirectional P-33(i) fluxes revealed potent active transport from CSF to the blood side under short-circuited conditions. The flux ratio was 8: 1 with an average transepithelial resistance of 87 +/- 17.9 Omega . cm(2) and electrical potential difference of + 0.9 +/- 0.17 mV (CSF side positive). Active P-i absorption from CSF was inhibited by 10 mM arsenate, 0.2 mM ouabain, Na+ -free medium, and increasing the K+ concentration from 5 to 100 mM. Li+ stimulated transport twofold compared with Na+-free medium. Phosphonoformic acid (1 mM) had no effect on active Pi transport. RT-PCR revealed both P-i transporter (PiT) 1 and PiT2 (SLC20 family) gene expression, but no Na+ -P-i cotransporter II (SLC34 family) expression, in the shark CP. PiT2 immunoreactivity was shown by immunoblot analysis and localized by immunohistochemistry in (or near) the CP apical microvillar membranes of both the shark and rat. PiT1 appeared to be localized primarily to vascular endothelial cells. Taken together, these data indicate that the CP actively removes P-i from CSF. This process has transport properties consistent with a PiT2, Na+-dependent transporter that is located in the apical region of the CP epithelium.National Science Foundation [0843253]; Fundacao para a Ciencia e a Tecnologia, Portuga

Harmonic moment dynamics in Laplacian growth

Harmonic moments are integrals of integer powers of z = x+iy over a domain. Here the domain is an exterior of a bubble of air growing in an oil layer between two horizontal closely spaced plates. Harmonic moments are a natural basis for such Laplacian growth phenomena because, unlike other representations, these moments linearize the zero surface tension problem (Richardson, 1972), so that all moments except the lowest one are conserved in time. For non-zero surface tension, we show that the the harmonic moments decay in time rather than exhibiting the divergences of other representations. Our laboratory observations confirm the theoretical predictions and demonstrate that an interface dynamics description in terms of harmonic moments is physically realizable and robust. In addition, by extending the theory to include surface tension, we obtain from measurements of the time evolution of the harmonic moments a value for the surface tension that is within 20% of the accepted value.Comment: 10 pages, 7 figure

La visibilité du genre dans quelques revues de sociologie du travail : Comparaisons France et Grande-Bretagne (1987-2012)

International audienceLe travail a constitué un objet privilégié des premières recherches académiques sur les rapports sociaux de sexe en France et les ‘études genre’ y sont restées marquées par cet héritage. Peut-on affirmer pour autant que les dimensions sexuées du travail sont désormais intégrées au cœur de la sociologie du travail et que les spécialistes du genre y sont reconnu·e·s à part entière ? Pour répondre à ces questions, nous proposons une analyse comparative de l’évolution du nombre d’articles consacrés au ‘genre du travail’ dans deux revues de sociologie du travail en France et en Grande-Bretagne. Nous montrons que la part de recherches portant sur les dimensions sexuées du travail à trouver place dans ces revues est beaucoup plus réduite en France qu’outre-Manche, et ceci tout au long de la période étudiée. La ‘cécité au genre’ qui perdure au sein de la sociologie du travail en France n’occulte pas seulement la réalité laborieuse des femmes de ce pays, elle invisibilise et marginalise également les (femmes) spécialistes du genre au sein de ce champ académique [1]

New loci for body fat percentage reveal link between adiposity and cardiometabolic disease risk

To increase our understanding of the genetic basis of adiposity and its links to cardiometabolic disease risk, we conducted a genome-wide association meta-analysis of body fat percentage (BF%) in up to 100,716 individuals. Twelve loci reached genome-wide significance (P\u3c5 × 10−8), of which eight were previously associated with increased overall adiposity (BMI, BF%) and four (in or near COBLL1/GRB14, IGF2BP1, PLA2G6, CRTC1) were novel associations with BF%. Seven loci showed a larger effect on BF% than on BMI, suggestive of a primary association with adiposity, while five loci showed larger effects on BMI than on BF%, suggesting association with both fat and lean mass. In particular, the loci more strongly associated with BF% showed distinct cross-phenotype association signatures with a range of cardiometabolic traits revealing new insights in the link between adiposity and disease risk

Early Paleogene fluvial regime shift in response to global warming: A subtropical record from the Tornillo Basin, west Texas, USA

The early Paleogene was a dynamic period marked by long-term climatic trends and rapid climate events superimposed upon a hot greenhouse state. The response of the terrestrial hydrological cycle to these climate variations can be investigated at the continental scale by analysis of Paleogene strata in Laramide basins and the Gulf of Mexico. New U-Pb geochronologic data from detrital zircons in Paleogene fluvial strata of the Tornillo Basin in west Texas indicate relatively continuous deposition from 63 to 47 Ma. The combination of detrital zircon ages with existing carbon isotope chemostratigraphic data allows us to revise the age model of these strata and to correlate stratigraphic changes with Paleogene climate variations. Sedimentologic data indicate that, during the Paleocene (63-55.5 Ma), high-sinuosity, fluvial systems meandered on a forested floodplain with well-developed soils and swamps. The fluvial regime changed abruptly to lowsinuosity, braided fluvial systems with floodplains characterized by intermittent wetting at the Paleocene-Eocene thermal maximum (55.5 Ma). Braided fluvial regimes persisted thereafter and culminated during the early Eocene climate optimum (52-50 Ma) with deposition of a coarse sheet of sand and gravel. We interpret the transition from meandering to braided fluvial systems as a shift in discharge and sediment supply associated with the more seasonal precipitation of the hot, subtropical monsoonal climate of the early Eocene. After 54 Ma, this shift in fluvial regime is superimposed by an upwardcoarsening grain-size trend probably driven by enhanced regional Laramide tectonism. These data provide the first reconstruction of Paleogene subtropical fluvial dynamics in western North America and correlate with regional and global changes in Paleogene climate and landscapes

Effect of age on melanoma risk, prognosis and treatment response

As for all types of cancer, the incidence of melanoma increases with age. However, naevus counts (the principal risk factor for melanoma) decrease with age; hence the relationship between ageing and melanoma is complex. Subjects who maintain a high naevus count after the age of 50 years are more likely to be affected by melanoma, as their lesions do not senesce. Longer telomere length, which is strongly related to age, is linked to high naevus counts/melanoma risk; thus melanoma biology is influenced by factors that slow down ageing. Age is also an important prognostic factor in melanoma. Increasing age leads to worse survival in stages I, II and III. Sentinel lymph node (SLN) status, which is a strong predictor of melanoma survival, is also affected by age, as SLN positivity decreases with age. However, the prognostic value of SLN on survival increases with age, so, again, these relationships are complex. In patients with stage IV melanoma, age impacts on survival because it affects responses to treatment. This review examines the effects of age on melanoma risk, prognostic factors and responses to treatment

Glucagon receptor family in GtoPdb v.2023.1

The glucagon family of receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on the Glucagon receptor family [165]) are activated by the endogenous peptide (27-44 aa) hormones glucagon, glucagon-like peptide 1, glucagon-like peptide 2, glucose-dependent insulinotropic polypeptide (also known as gastric inhibitory polypeptide), GHRH and secretin. One common precursor (GCG) generates glucagon, glucagon-like peptide 1 and glucagon-like peptide 2 peptides [121]. For a recent review on the current understanding of the structures of GLP-1 and GLP-1R, the molecular basis of their interaction, and the associated signaling events see de Graaf et al., 2016 [90]

Care in the time of catastrophe: citizenship, community and the ecological imagination

Published without an abstract