Zona pellucida from fertilised human oocytes induces a voltage-dependent calcium influx and the acrosome reaction in spermatozoa, but cannot be penetrated by sperm

BACKGROUND: The functions of three zona glycoproteins, ZP1, ZP2 and ZP3 during the sperm-zona pellucida (ZP) interaction are now well established in mice. The expression of an additional zona glycoprotein, ZPB/4, in humans, led us to reconsider the classical mouse model of gamete interaction. We investigated the various functions of human ZP (hZP) during the interaction of spermatozoa with fertilised and unfertilised oocytes. RESULTS: The hZP of fertilised oocytes retained their ability to bind sperm (albeit less strongly than that from unfertilised oocytes), to induce an intraspermatic calcium influx through voltage-dependent channels similar to that observed with hZP from unfertilised oocytes and to promote the acrosome reaction at a rate similar to that induced by the ZP of unfertilised oocytes (61.6 ± 6.2% vs60.7 ± 9.1% respectively). Conversely, the rate of hZP penetrated by sperm was much lower for fertilised than for unfertilised oocytes (19% vs 57% respectively, p < 0.01). We investigated the status of ZP2 in the oocytes used in the functional tests, and demonstrated that sperm binding and acrosome reaction induction, but not ZP penetration, occurred whether or not ZP2 was cleaved. CONCLUSION: The change in ZP function induced by fertilisation could be different in human and mouse species. Our results suggest a zona blocking to polyspermy based at the sperm penetration level in humans

Landslide dams in the Central Andes of Argentina: showing the need of revising the established landslide dam classification

The Andean cordillera of Argentina is more than 3500 km long and 50 to 550 km wide and characterized by steep relief contrasts throughout. Except for a few valleys, most of this region is scarcely populated. Hence geologic mapping was mainly carried out on a scale (1:250000), which is often too small to map out various Quaternary units and therefore to highlight relations of landslide deposits with lakes or lake deposits. However, in the last years various studies have been carried out, concentrating on large landslides and their relations with valley impoundments (GONZÁLEZ DIAZ & MON, 1996; HERMANNS & STRECKER, 1999; TRAUTH & STRECKER, 1999; GONZÁLEZ DÍAZ et alii, 2000; HERMANNS et alii, 2000; TRAUTH et alii, 2000; FAUQUE et alii, 2000; FAUQUÉ & TCHILINGUIRIAN, 2002; TRAUTH et alii, 2003; HERMANNS et alii, 2003; HERMANNS et alii, 2005; FAUQUE et alii, 2005; PENNA et alii, 2005; GONZÁLEZ DÍAZ et alii, 2005). Before that, most attention was given to the catastrophic rock avalanche dam failure in the Barrancas valley causing the 1914 Río Colorado flood (GROEBER, 1916; GONZÁLEZ DÍAZ et alii, 2001; SCHUSTER et alii, 2002; HERMANNS et alii, 2004a). In this paper we will focus on two regions: one in the NW Argentine (24° - 27.5° S) and one in northern Patagonia (36° – 38° S). In both regions the authors have carried out systematic studies related to landslides with volumes in excess of 106 m3. These landslides formed at least 16 and 48 landslide dams in the two regions, respectively (Figure 1). In the following, due to the briefness of this paper, only peculiarities of the various cases will be described which will help to better understand large landslide dams in other regions as well. For the complete data set of both study areas we refer to the comprehensive paper, which will be published within the related NATO Science Series book. Likewise, we omit a setting description of the regions and refer here to the papers cited above.Fil: Hermanns, R. L.. Canadian Geological Survey; CanadáFil: Folguera Telichevsky, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Gonzalez Diaz, E. F.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Fauque, L.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; Argentin

Anisotropic and strong negative magneto-resistance in the three-dimensional topological insulator Bi2Se3

We report on high-field angle-dependent magneto-transport measurements on epitaxial thin films of Bi2Se3, a three-dimensional topological insulator. At low temperature, we observe quantum oscillations that demonstrate the simultaneous presence of bulk and surface carriers. The magneto- resistance of Bi2Se3 is found to be highly anisotropic. In the presence of a parallel electric and magnetic field, we observe a strong negative longitudinal magneto-resistance that has been consid- ered as a smoking-gun for the presence of chiral fermions in a certain class of semi-metals due to the so-called axial anomaly. Its observation in a three-dimensional topological insulator implies that the axial anomaly may be in fact a far more generic phenomenon than originally thought.Comment: 6 pages, 4 figure

Origin of the Pseudogap in High-Temperature Cuprate Superconductors

Cuprate high-temperature superconductors exhibit a pseudogap in the normal state that decreases monotonically with increasing hole doping and closes at x \approx 0.19 holes per planar CuO2 while the superconducting doping range is 0.05 < x < 0.27 with optimal Tc at x \approx 0.16. Using ab initio quantum calculations at the level that leads to accurate band gaps, we found that four-Cu-site plaquettes are created in the vicinity of dopants. At x \approx 0.05 the plaquettes percolate, so that the Cu dx2y2/O p{\sigma} orbitals inside the plaquettes now form a band of states along the percolating swath. This leads to metallic conductivity and below Tc to superconductivity. Plaquettes disconnected from the percolating swath are found to have degenerate states at the Fermi level that split and lead to the pseudogap. The pseudogap can be calculated by simply counting the spatial distribution of isolated plaquettes, leading to an excellent fit to experiment. This provides strong evidence in favor of inhomogeneous plaquettes in cuprates.Comment: 24 pages (4 pages main text plus 20 pages supplement

Hoja Geológica 2969-IV, Villa Unión

La Hoja Geológica 2969-IV Villa Unión abarca parte de la región noroccidental de la Provincia de La Rioja y el sector occidentalde la Hoja comprende una porción del noreste de la provincia de San Juan. Se extiende entre los paralelos 29º y 30º de latitud sur yentre los meridianos 67º 30 y 69º de longitud oeste, cubriendo una superfi cie aproximada de 18.000 km2. La Hoja toma el nombrede la localidad más importante del oeste riojano, Villa Unión. Otra localidad importante del mismo sector es Villa Castelli, como laanterior, a orillas del río Vinchina-Bermejo, en el límite norte de la Hoja. La localidad más occidental de la Hoja es Guandacol enla depresión tectónica recorrida por el río homónimo. Finalmente al naciente de la sierra de Famatina y dentro del área de la Hojase ubican, de norte a sur las localidades de: Las Higueritas, Chilecito, Sañogasta y Vichigasta. La Hoja Villa Unión incluye partede tres provincias geológicas argentinas, de este a oeste: Sistema de Famatina, Sierras Pampeanas occidentales y Precordillera.En la Hoja Villa Unión afl oran basamentos metamórfi cos muy distintos como consecuencia de las colisiones y acreciones dediferentes terrenos (Famatina, Cuyania y Chilenia) ocurridas durante el Proterozoico superior y el Paleozoico inferior. Los terrenosmetamórfi cos del Sistema de Famatina son de muy bajo a bajo grado, mientras que los terrenos metamórfi cos de Sierras PampeanasOccidentales son de grado medio a alto. El basamento correspondiente a Sierras Pampeanas Occidentales, afl orante en la Hoja VillaUnión, conforma los bloques serranos de Umango, Maz, Espinal y Las Ramaditas, elevados como consecuencia de la tectónicaterciaria-cuaternaria. En ellos las litologías predominantes son: gneises, esquistos, calizas, anfi bolitas y granitoides. En la sierra deFamatina el basamento esta representado por la Formación Negro Peinado, compuesta por leptometamorfi tas. Sobre ellas se apoyanen discordancia sedimentitas ordovícicas de la Formación Suri que se interdigitan con rocas volcánicas. Estas rocas están intruidaspor una secuencia de cuerpos plutónicos calcoalcalinos de la Formación Ñuñorco, caracterizada por gabros, tonalitas, granodioritas ygranitos, con un clímax de actividad magmática en el Ordovícico medio a superior. Ellas representan un arco magmático desarrolladoen un margen continental activo. Cuyania es un terreno compuesto, con suturas internas representadas por una faja ofi olítica de edadGrenville. Los terrenos amalgamados (Precordillera y Pie de Palo) para formar Cuyania serían posibles arcos de islas intraoceánicosrepresentados por anfi bolitas y gneises. Sobre Cuyania se desarrolló una plataforma calcárea de edad cambro-ordovícica. Las rocasmás antiguas de esta secuencia afloran al noroeste de Guandacol, estan constituidas por depósitos continentales rojos y evaporitasde edad cámbrica inferior (Formación Cerro Totora). En discordancia se apoyan los depósitos de plataforma carbonática (FormaciónSan Juan), además de secuencias ordovícicas clásticas (Formación Guandacol, Formación Yerba Loca) y fi nalmente secuenciasclásticas con niveles conglomerádicos (Grupo Trapiche) del Ordovícico superior.Fil: Fauque, Luis Enrique. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Limarino, Carlos Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Vujovich, G.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Cegarra, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Yamín, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Tedesco, A.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Ecosteguy, L.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Cardó, R.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Díaz, I.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Franchi, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Etcheverría, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; Argentin

The Intensity of IUGR-Induced Transcriptome Deregulations Is Inversely Correlated with the Onset of Organ Function in a Rat Model

A low-protein diet applied during pregnancy in the rat results in intrauterine growth restricted (IUGR) fetuses. In humans, IUGR is associated with increased perinatal morbidity, higher incidence of neuro-developmental defects and increased risk of adult metabolic anomalies, such as diabetes and cardiovascular disease. Development and function of many organs are affected by environmental conditions such as those inducing fetal and early postnatal growth restriction. This phenomenon, termed “fetal programming” has been studied unconnectedly in some organs, but very few studies (if any) have investigated at the same time several organs, on a more comparative basis. However, it is quite probable that IUGR affects differentially most organ systems, with possible persistent changes in gene expression. In this study we address transcriptional alterations induced by IUGR in a multi-organ perspective, by systematic analysis of 20-days rat fetuses. We show that (1) expressional alterations are apparently stronger in organs functioning late in foetal or postnatal life than in organs that are functioning early (2) hierarchical classification of the deregulations put together kidney and placenta in one cluster, liver, lungs and heart in another; (3) the epigenetic machinery is set up especially in the placenta, while its alterations are rather mild in other organs; (4) the genes appear deregulated in chromosome clusters; (5) the altered expression cascades varies from organ to organ, with noticeably a very significant modification of the complement and coagulation cascades in the kidney; (6) we found a significant increase in TF binding site for HNF4 proteins specifically for liver genes that are down-regulated in IUGR, suggesting that this decrease is achieved through the action of HNF transcription factors, that are themselves transcriptionnally induced in the liver by IUGR (x 1.84 fold). Altogether, our study suggests that a combination of tissue-specific mechanisms contributes to bring about tissue-driven modifications of gene cascades. The question of these cascades being activated to adapt the organ to harsh environmental condition, or as an endpoint consequence is still raised

Petri Net computational modelling of Langerhans cell Interferon Regulatory Factor Network predicts their role in T cell activation

Langerhans cells (LCs) are able to orchestrate adaptive immune responses in the skin by interpreting the microenvironmental context in which they encounter foreign substances, but the regulatory basis for this has not been established. Utilising systems immunology approaches combining in silico modelling of a reconstructed gene regulatory network (GRN) with in vitro validation of the predictions, we sought to determine the mechanisms of regulation of immune responses in human primary LCs. The key role of Interferon regulatory factors (IRFs) as controllers of the human Langerhans cell response to epidermal cytokines was revealed by whole transcriptome analysis. Applying Boolean logic we assembled a Petri net-based model of the IRF-GRN which provides molecular pathway predictions for the induction of different transcriptional programmes in LCs. In silico simulations performed after model parameterisation with transcription factor expression values predicted that human LC activation of antigen-specific CD8 T cells would be differentially regulated by epidermal cytokine induction of specific IRF-controlled pathways. This was confirmed by in vitro measurement of IFN-g production by activated T cells. As a proof of concept, this approach shows that stochastic modelling of a specific immune networks renders transcriptome data valuable for the prediction of functional outcomes of immune responses

Localized Fetomaternal Hyperglycemia: Spatial and Kinetic Definition by Positron Emission Tomography

to isolated hyperglycemia in the pregnant rat. mg/dL) localized to the left uterine artery was sustained for at least 48 hours while maternal euglycemia was maintained. fetal effects of isolated hyperglycemia. Broadly, this approach can be extended to study a variety of maternal-sided perturbations suspected to directly affect fetal health