Spatial pattern of landslides in Swiss Rhone Valley

The present study analyses the spatial pattern of quaternary gravitational slope deformations (GSD) and historical/present-day instabilities (HPI) inventoried in the Swiss Rhone Valley. The main objective is to test if these events are clustered (spatial attraction) or randomly distributed (spatial independency).Moreover, analogies with the cluster behaviour of earthquakes inventoried in the same area were examined. The Ripley's K-function was applied to measure and test for randomness. This indicator allows describing the spatial pattern of a point process at increasing distance values. To account for the non-constant intensity of the geological phenomena, a modification of the K-function for inhomogeneous point processes was adopted. The specific goal is to explore the spatial attraction (i.e. cluster behaviour) among landslide events and between gravitational slope deformations and earthquakes. To discover if the two classes of instabilities (GSD and HPI) are spatially independently distributed, the cross K-function was computed. The results show that all the geological events under study are spatially clustered at a well-defined distance range. GSD and HPI show a similar pattern distribution with clusters in the range 0.75-9 km. The cross K-function reveals an attraction between the two classes of instabilities in the range 0-4 km confirming thatHPI are more prone to occur within large-scale slope deformations. The K-function computed for GSD and earthquakes indicates that both present a cluster tendency in the range 0-10 km, suggesting that earthquakes could represent a potential predisposing factor which could influence the GSD distribution.Fil: Tonini, Marj. Universite de Lausanne; SuizaFil: Pedrazzini, Andrea. Universite de Lausanne; SuizaFil: Penna, Ivanna Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos; Argentina. Universite de Lausanne; SuizaFil: Jaboyedoff, Michel. Universite de Lausanne; Suiz

Measuring the Spins of Stellar Black Holes: A Progress Report

We use the Novikov-Thorne thin disk model to fit the thermal continuum X-ray spectra of black hole X-ray binaries, and thereby extract the dimensionless spin parameter a* = a/M of the black hole as a parameter of the fit. We summarize the results obtained to date for six systems and describe work in progress on additional systems. We also describe recent methodological advances, our current efforts to make our analysis software fully available to others, and our theoretical efforts to validate the Novikov-Thorne model.Comment: 6 pages, conference proceedings, X-ray Astronomy 2009: Present Status, Multi-Wavelength Approach and Future Perspectives, AIP, eds. A. Comastri et al.; list of authors revise

Characterization of landslide dams in the San Juan province (Argentina)

River blockages caused by landslide deposition are common phenomena in active mountain chains, influencing erosion-sedimentation patterns and acting as primary and secondary hazards. Regional scale analyses regarding their spatial distribution and morphometry allow establishing boundary conditions for their occurrence and stability, and determine differences among regions with different landscape and climatic conditions. Owing to the combination of endogenous and exogenous factors, landslide dams are frequent phenomena in the Andes. In the Argentinean NW and the Patagonian Andes, previous studies showed that stability of landslide dams determined by morphometric parameters generally matched satisfactorily with dam behavior, with some exceptions in which climatic component played an important role in dam longevity. Aiming to expand the knowledge of landslide dams in the Argentinean Andes, in this work we analyzed the stability of rock avalanche dams in the Pampeam flat slab subduction zone. In the study area, mountain dynamics creates suitable conditions for the occurrence of 34 rock avalanches with volumes up to 0.3 km3. They developed in deeply carved valleys (Cordillera) and Inter-thrust valleys (Precordillera). 22 impoundments of rivers resulted from channelized rock avalanches with long runouts (4-10 km) that blocked tributaries rivers, but most of them by rock avalanches that filled the valley bottom, with run up in the opposite slope and limited movement parallel to the valley axis. Most of the dams breached in unknown times, except for the last event that occurred on November 12th 2005. The quantification of morphometric parameters and contributing areas indicates the existence of dams with dimensionless blockage index above 2.75 (stable domain) and below 3.08 (instable domain). The Los Erizos dam in our study area and the Barrancas dam in the Patagonian Andes show that besides morphometric parameters, climatic conditions are decisive. Stable landslide dams lasting for millennia can collapse suddenly due to anomalous weather conditions, and unstable dams can have a higher longevity depending on the season controlling the inflow into the lake.Fil: Penna, Ivanna Marina. 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: Longchamp, Celine. Universite de Lausanne; SuizaFil: Derron, Marc Henri. Universite de Lausanne; SuizaFil: Jaboyedoff, Michel. Universite de Lausanne; SuizaEGU General Assembly 2013AustriaEuropean Geosciences Unio

Expression of green fluorescent protein (GFPuv) in Escherichia coli DH5-a, under different growth conditions

The recombinant green fluorescent protein (GFPuv) was expressed by transformed cells of Escherichia coli DH5-α grown in LB/amp broth at 37oC, for 8 h and 24 h. To evaluate the effectiveness of different parameters to improve the expression of GFPuv by E. coli, four variable culturing conditions were set up for assays by a fractional factorial (24-1) design at two levels: (i) the effect of storing (24-48 h) the seeded broth at 4oC prior to incubation at 37oC; (ii) the effect of agitation speed (100-200 rpm); (iii) the final concentration (0.05-0.5 mM) of IPTG (isopropyl–β-D-thiogalactopyranoside); and (iv) the addition of IPTG at set cell densities (OD660 0.01-0.8). GFPuv was extracted from cells by the three phase partitioning method (TPP) and further purified with a methyl HIC column. The cultures grown at 37oC/24 h provided the highest yields of GFPuv under the conditions: (i) pre-storage at 4oC/24 h; (ii) agitation speed at 100 rpm; (iii) 0.5 mM IPTG; (iv) IPTG addition at OD660=~0.01. On the other hand, at 37oC/ 8 h, GFPuv expression was dependent upon agitation of broth cultures at 200 rpm and the IPTG addition at the beginning of the growth exponential phase. Key Words: Green fluorescent protein (GFPuv), Escherichia coli DH5-α, growth kinetic parameters, expressed GFPuv kinetic parameters, three phase partitioning extraction (TPP). African Journal of Biotechnology Vol.3(1) 2004: 105-11

Mass wasting and catastrophic collapse of natural dams in the Andean orogenic front (36º-38ºS): The Navarrete and Río Barrancas case studies

En los Andes nor-neuquinos, existe una gran concentración de depósitos de avalanchas de roca que generan endicamientos naturales. El colapso temprano de estos diques generados por deslizamientos de ladera es el proceso evolutivo más probable. Paleocostas, profundas y agudas brechas de colapso, y depósitos de outburst flood permiten reconstruir las características de las lagunas asociadas a los respectivos diques. En esta región, el último evento glaciario ha creado pendientes abruptas y fracturación interna de los materiales, los que determinaron un aumento de la susceptibilidad al colapso de las pendientes por factores externos como sismicidad o precitaciones. La distribución de las avalanchas aparenta estar asociada a la intersección entre fallas con actividad cuaternaria y los valles glaciarios. Este trabajo mostrará actividad neotectónica en el valle del arroyo PichiNeuquén, donde se encuentra el retrocorrimiento Aguas Calientes, que presenta estratos de crecimiento cuaternarios en el labio colgante de la falla. Adicionalmente, se observan probables sismitas en la desembocadura del arroyo Colorado. Este trabajo tiene como objetivo comparar el origen, similitud de inductores (probable actividad sísmica) y ambiente geomorfológico de las avalanchas Río Barrancas y Navarrete, con énfasis en esta última. El primer dique natural mencionado ha colapsado catastróficamente (debido a un aumento del influjo de agua a la laguna) luego de 2,2 Ka de existencia. En el segundo caso, la edad del depósito de avalancha y sus causas de colapso son aún inciertas. La existencia de un flujo de detritos en la margen este de la laguna Navarrete y la similar cota entre la paleocosta y el tope del dique, permiten proponer distintas hipótesis acerca de las causas de colapso del dique.Mass wasting and catastrophic collapse of natural dams in the Andean orogenic front (36º-38ºS): The Navarrete and Río Barrancas case studies. A high concentration of rock avalanches, most of them resulting in natural dams, is possible to recognize in the Andes of the northern Neuquén. In landslide dams the most probable evolutionary process corresponds to their early collapses. Paleoshorelines, deep and narrow breaches, and outburst flood deposits permit to rebuild the characteristics of the related lakes. The last glaciation in this region, have created steep slopes and physical rock weathering. These facts determined an increase in the susceptibility to slope failure triggered by seismicity and precipitation. The distribution of rock avalanches seems to be related to the interaction between young deformation and the glacial valleys. The Aguas Calientes backthrust in the Pichi-Neuquén valley is associated with Pliocene to Quaternary growth-strata, and probable seismic triggered liquefaction of sediments in the Colorado creek, and has evidence of neotectonic activity in the entire study area. The aim of this work is to compare the Río Barrancas and Navarrete rock avalanches, with special emphasis in the last one, and establish similitude in their triggering factor (probable seismic activity) and geomorphic environment. The Río Barrancas dam has collapsed (due to an increase in the water influx into the lake) after 2,200 years of existence. For the Navarrete case, the age of slope failure and causes of the collapse of the natural dam are still unknown. The presence of a debris flow in the eastern margin of the lake, and the similar altitude between the paleoshoreline and the top of the dam, would permit to propose two different scenarios.Fil: Penna, Ivanna Marina. 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: Hermanns, Reginald 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"; Argentin

Prostorna raspodjela fizikalnih, kemijskih i bioloških oceanografskih karakteristika, fitoplanktona, hranjivih tvari i otopljene obojane organske materije (CDOM) u Bokokotorskom zaljevu na Jadranu

The temporal variations of temperature, salinity, fluorescence, dissolved oxygen concentration, Coloured Dissolved Organic Matter (CDOM) and of chemical (nutrients, chlorophyll a) and biological (phytoplankton composition) parameters in the Boka Kotorska Bay were observed during two periods. CDOM regulates the penetration of UV light into the sea and therefore plays an important role in many hydrological and biogeochemical processes in the sea surface layer including primary productivity. In the framework ADRICOSM-STAR it was possible to investigate the Boka Kotorska Bay during May and June 2008 in order to increase an understanding of optical and chemical characteristics and their evolution during these periods. In both periods station KO (located furthest from the open sea) presented different physical, chemical and biological characteristics with respect to the other stations inside the Boka Kotorska Bay. A positive correlation was found between CDOM and chlorophyll a (R = 0.7, P < 0.001, n = 15) and this implies that in this area, similarly to the open sea, the primary source of CDOM should be the biological production from phytoplankton. This is probably due to the fact that the rivers entering the Boka Kotorska Bay are not severely impacted by man.U Bokokotorskom zaljevu su mjerene vremenske promjene temperature, saliniteta, fluorescencije, koncentracije otopljenog kisika, obojene otopljene organske materije (CDOM) i kemijskih (hranjive soli, klorofila) i bioloških (sastav fitoplanktona) parametara tijekom dva razdoblja (svibanj i lipanj 2008. godine). CDOM određuje prodiranje UV svjetlosnih zraka u more i stoga igra vrlo važnu ulogu u mnogim hidrološkim i biogeokemijskim procesima u površinskom sloju mora koji uključuje primarnu produkciju. Unutar ADRICOSM-STAR projekta, bilo je moguće istražiti Bokokotorski zaljev tijekom svibnja i lipnja 2008. godine radi povećanja razumijevanja optičkih i kemijskih karakteristika i njihovog razvoja kroz ova razdoblja. Zbog dotoka krških rijeka i smanjenja razmjene s otvorenim morem, u oba razdoblja postaja KO (smještena najdalje od otvorenog mora) je pokazala različite fizikalne, kemijske i biolo{ke karakteristike u odnosu na postaje unutar Bokokotorskog zaljeva. Pronađena je pozitivna korelacija izme|u CDOM i klorofila a (R = 0.7, P < 0.001, n = 15) {to upućuje na to da bi u ovom području, slično otvorenom moru, primarni izvor CDOM trebao biti biološka produkcija od fitoplanktona. To je vjerojatno zbog toga što dotoci rijeka u Bokokotorskom zaljevu nisu ozbiljnije ugroženi ljudskim djelovanjem

Growth hormone-releasing hormone attenuates cardiac hypertrophy and improves heart function in pressure overload-induced heart failure

It has been shown that growth hormone-releasing hormone (GHRH) reduces cardiomyocyte (CM) apoptosis, prevents ischemia/reperfusion injury, and improves cardiac function in ischemic rat hearts. However, it is still not known whether GHRH would be beneficial for life-threatening pathological conditions, like cardiac hypertrophy and heart failure (HF). Thus, we tested the myocardial therapeutic potential of GHRH stimulation in vitro and in vivo, using GHRH or its agonistic analog MR-409. We show that in vitro, GHRH(1-44)NH2attenuates phenylephrine-induced hypertrophy in H9c2 cardiac cells, adult rat ventricular myocytes, and human induced pluripotent stem cell-derived CMs, decreasing expression of hypertrophic genes and regulating hypertrophic pathways. Underlying mechanisms included blockade of Gq signaling and its downstream components phospholipase Cβ, protein kinase Ce, calcineurin, and phospholamban. The receptor-dependent effects of GHRH also involved activation of Gαsand cAMP/PKA, and inhibition of increase in exchange protein directly activated by cAMP1 (Epac1). In vivo, MR-409 mitigated cardiac hypertrophy in mice subjected to transverse aortic constriction and improved cardiac function. Moreover, CMs isolated from transverse aortic constriction mice treated with MR-409 showed improved contractility and reversal of sarcolemmal structure. Overall, these results identify GHRH as an antihypertrophic regulator, underlying its therapeutic potential for HF, and suggest possible beneficial use of its analogs for treatment of pathological cardiac hypertrophy

Clamídia e infertilidade feminina: uma revisão abrangente da epidemiologia e implicações clínicas

A clamídia, causada pela bactéria Chlamydia trachomatis, é uma das infecções sexualmente transmissíveis mais prevalentes em todo o mundo. Sua associação com a infertilidade feminina é uma preocupação significativa de saúde pública, exigindo uma compreensão abrangente dos mecanismos subjacentes e estratégias de prevenção eficazes. Este estudo teve como objetivo investigar a epidemiologia da clamídia, os mecanismos pelos quais ela pode levar à infertilidade feminina, bem como o impacto desta infecção na saúde reprodutiva das mulheres. Foi realizada uma revisão abrangente da literatura científica disponível sobre clamídia e infertilidade feminina, utilizando bases de dados eletrônicas como PubMed, Scielo e LILACS. A revisão revelou uma alta prevalência de clamídia entre mulheres em idade reprodutiva e uma associação significativa com a infertilidade. Mecanismos patogênicos incluem inflamação crônica, lesões tubárias e disfunção ovariana. A detecção precoce é essencial para evitar danos irreversíveis à fertilidade. A clamídia representa uma importante causa de infertilidade feminina, destacando a necessidade de programas de rastreamento e intervenções precoces para prevenir complicações reprodutivas. Estratégias de prevenção, como educação sobre saúde sexual são fundamentais para reduzir a incidência dessa infecção. Além disso, são necessárias pesquisas contínuas para melhorar os métodos de diagnóstico, tratamento e prevenção da clamídia e suas complicações relacionadas à fertilidade

Phosphocaveolin-1 enforces tumor growth and chemoresistance in rhabdomyosarcoma

Caveolin-1 (Cav-1) can ambiguously behave as either tumor suppressor or oncogene depending on its phosphorylation state and the type of cancer. In this study we show that Cav-1 was phosphorylated on tyrosine 14 (pCav-1) by Src-kinase family members in various human cell lines and primary mouse cultures of rhabdomyosarcoma (RMS), the most frequent soft-tissue sarcoma affecting childhood. Cav-1 overexpression in the human embryonal RD or alveolar RH30 cells yielded increased pCav-1 levels and reinforced the phosphorylation state of either ERK or AKT kinase, respectively, in turn enhancing in vitro cell proliferation, migration, invasiveness and chemoresistance. In contrast, reducing the pCav-1 levels by administration of a Src-kinase inhibitor or through targeted Cav-1 silencing counteracted the malignant in vitro phenotype of RMS cells. Consistent with these results, xenotransplantation of Cav-1 overexpressing RD cells into nude mice resulted in substantial tumor growth in comparison to control cells. Taken together, these data point to pCav-1 as an important and therapeutically valuable target for overcoming the progression and multidrug resistance of RMS