Mollusks (Gastropoda and Bivalvia) of the multiple-use reserve martín garcía Island, Río de la plata river: biodiversity and ecology

The Island of Martin Garcia is located in the Upper Río de la Plata, to the south of mouth the Uruguay River. The aim of the present study was to analyse the biodiversity of the island freshwater mollusks and their relationships to environmental variables. Twelve sampling sites were selected, five were along the littoral section of the island and seven were Inland ponds. Seven major environmental variables were measured: water and air temperature, percentage of oxygen saturation, dissolved oxygen, electrical conductivity, total dissolved solids and pH. Twenty-seven mollusk species were found, Antillorbis nordestensis, Biomphalaria tenagophila tenagophila, B. t. guaibensis, B. straminea, B. peregrina, Drepanotrema kermatoides, D. cimex, D. depressissimum, Chilina fluminea, C. rushii, C. megastoma, Uncancylus concentricus, Hebetancylus moricandi, Stenophysa marmorata, Heleobia piscium, H. parchappii, Potamolithus agapetus, P. buschii, P. lapidum, Pomacea canaliculata, P. megastoma Asolene platae, Corbicula fluminea, Eupera platensis, Pisidium sterkianum, P. taraguyense and Limnoperna fortunei. UPGMA clustering of species based on their occurrence in different ecological conditions revealed two main species groups. The Canonical Correspondence Analysis suggests that the species distribution is related to the physico-chemical condition of water. Axis two of the ordination diagram displayed the approximately 95.6% of the correlation between species and environmental variables. Dissolved oxygen, conductivity, water temperature and pH showed the highest fluctuations during the sampling period. The species richness (S) showed relationships mainly with water temperature and conductivity. The biodiversity of the gastropods and bivalves from Martín García Island amounts to up to 26 species. Among the Gastropoda, the Planorbidae family made the most sizeable contribution. The Lithogliphidae P. agapetus (26.28%) and P. buschii (9.50%) showed the highest relative frequencies of occurrence within the littoral environments, while the Planorbidae D. cimex (23.83%) and D. kermatoides (11.59%) likewise did so in the inland ponds

Le urgenze ematologiche

Introduzione M. Scudeletti La trombocitopenia immune M. Cavalleri, P. Pitto, S. Timitilli, M. Scudeletti Approccio dell’internista alla leucemia acuta G.L. Michelis Sindrome emolitico-uremica atipica e porpora trombotica trombocitopenica M. Brignone I linfomi aggressivi a rapida crescita M. Cavaliere L’emofilia A acquisita G.A. Berisso La gestione delle complicanze acute del paziente con mieloma multiplo R. Goretti Le complicanze trombo-emboliche nel paziente ematologico S. Panarello, C. Fioravanti, F. Raggi, G. Antonucci Come affrontare il paziente con leucocitosi e linfocitosi C. Venturino, R. Tassara Come affrontare il paziente con adenomegalia P. Gnerre, N. Artom, E. Schiavetta, L. Parodi Come affrontare il paziente con splenomegalia P. Gnerre, N. Artom, E. Schiavetta, L. Parodi Come affrontare il paziente con leucopenia G. Pastori, R. Tassara Come affrontare il paziente con trombocitosi L. Rebella, R. Tassara Policitemia vera o morbo di Vaquez E. Arboscello Approccio all’adulto con piastrinopenia R. Tassara, L. Paris La gestione delle infezioni nel paziente oncoematologico A.L. Garlaschelli, F. Artom La gammopatia di origine indeterminata S. Timitilli, M. Cavalleri, M. Scudeletti La malattia di Gaucher M. Cavaliere Come affrontare i pazienti con..

Anatomy of a high-silica eruption as observed by a local seismic network: the June 2011 Puyehue–Cordón Caulle event (southern Andes, Chile)

High-silica explosive eruptions are one of the most dangerous natural phenomena, yet it is unclear which processes are involved in this infrequent kind of event. We present the first systematic characterization of near-field seismicity associated with a large high-silica eruption analyzing data recorded before, during and after the 4 June 2011 rhyolitic eruption of Puyehue–Cordón Caulle Volcanic Complex (PCCVC). Results of a first-level data processing, developed by the Southern Andean Volcano Observatory (OVDAS) to monitor unrest and the evolution of the eruption, are complemented here with the relocation of hypocenters into a local 1D velocity model, the time series of the b value and the computation of the focal mechanism. This information allows us to define several phases before and after the onset of the eruption, describing details of the space–time evolution of seismicity, defining and characterizing the seismic sources, and identifying the structural control of the magmatic intrusion and stress variations during the eruption. Our results illuminate several underlying processes, with emphasis on the possible role that basement structures had on the storage, transport and evacuation of magma. Integrating our results with previous findings based on satellite geodesy and petrology of erupted materials, we discuss general conceptual models regarding destabilization of structurally controlled acidic magmatic systems, the pass from unrest to eruption, and changes in eruptive style and waning phases of eruptions, with broader implications for monitoring and forecast of violent silicic eruptions.</p

The Influence of Masculinity on Male Latino Adolescents’ Perceptions Regarding Dating Relationships and Dating Violence

In the United States, teen dating violence (TDV) is a concern across ethnic groups. Attitudes and correlates of violence differ by gender, culture, and acculturation. This study used a qualitative interpretive approach. Data were obtained in focus groups with 23 Latino male adolescents. Themes reflected contexts of participants’ lives, and definitions and nature of dating relationships and TDV. Participants described the importance of respecting dating partners, the destructive effects of TDV, and the pressure to display masculinity that can lead some young men to perpetrate TDV. These results may advance culturally relevant interventions to promote healthy relationships and prevent dating violence

Rapid South Atlantic spreading changes and coeval vertical motion in surrounding continents: Evidence for temporal changes of pressure-driven upper mantle flow

International audienceThe South Atlantic region displays (1) a topographic gradient across the basin, with Africa elevated relative to South America, (2) a bimodal spreading history with fast spreading rates in Late Cretaceous and Eo-Oligocene, and (3) episodic regional uplift events in the adjacent continents concentrated in Late Cretaceous and Oligocene. Here we show that these observations can be linked by dynamic processes within Earth's mantle, through temporal changes in asthenosphere flow beneath the region. The topographic gradient implies westward, pressure-driven mantle flow beneath the basin, while the rapid spreading rate changes, on order 10 million years, require significant decoupling of regional plate motion from the large-scale mantle buoyancy distribution through a mechanically weak asthenosphere. Andean topographic growth in late Miocene can explain the most recent South Atlantic spreading velocity reduction, arising from increased plate boundary forcing associated with the newly elevated topography. But this mechanism is unlikely to explain the Late Cretaceous/Tertiary spreading variations, as changes in Andean paleoelevation at the time are small. We propose an unsteady pressure-driven flow component in the asthenosphere beneath the South Atlantic region to explain the Late Cretaceous/Tertiary spreading rate variations. Temporal changes in mantle flow due to temporal changes in regional mantle pressure gradients imply a correlation of horizontal and vertical motions: we find that this prediction from our models agrees with geologic and geophysical observations of the South Atlantic region, including episodes of passive margin uplift, regional basin reactivation, and magmatic activity

Slab-derived devolatilization fluids oxidized by subducted metasedimentary rocks

Metamorphic devolatilization of subducted slabs generates aqueous fluids that ascend into the mantle wedge, driving the partial melting that produces arc magmas. These magmas have oxygen fugacities some 10–1,000 times higher than magmas generated at mid-ocean ridges. Whether this oxidized magmatic character is imparted by slab fluids or is acquired during ascent and interaction with the surrounding mantle or crust is debated. Here we study the petrology of metasedimentary rocks from two Tertiary Aegean subduction complexes in combination with reactive transport modelling to investigate the oxidative potential of the sedimentary rocks that cover slabs. We find that the metasedimentary rocks preserve evidence for fluid-mediated redox reactions and could be highly oxidized. Furthermore, the modelling demonstrates that layers of these oxidized rocks less than about 200 m thick have the capacity to oxidize the ascending slab dehydration flux via redox reactions that remove H2, CH4 and/or H2S from the fluids. These fluids can then oxidize the overlying mantle wedge at rates comparable to arc magma generation rates, primarily via reactions involving sulfur species. Oxidized metasedimentary rocks need not generate large amounts of fluid themselves but could instead oxidize slab dehydration fluids ascending through them. Proposed Phanerozoic increases in arc magma oxygen fugacity may reflect the recycling of oxidative weathering products following Neoproterozoic–Palaeozoic marine and atmospheric oxygenation

Effect of Related and Unrelated Donor Haematopoietic Stem-Cell Transplantation on Outcome in Adults With High Risk Hematological Disease: An intention-to-treat Analysis of 410 Patients at a Single Center Institution

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Efecto de Nostoc muscorum Ag. en la germinación in vitro de esporangios de Bremia lactucae Regel en Lactuca sativa L.

1-8Se analizó el efecto de extractos etéreo, metanólico y acuoso de 5 cepas de Nostoc muscorum en la germinación in vitro de esporangios de Bremia lactucae Regel durante una epifitia sobre Lactuca sativa var capitata cv gallega, en un predio hortícola intensivo de la localidad La Capilla-partido de Florencio Varela provincia Buenos Aires -Argentina (34º50'Lat sur 58º06' Long oeste). La cepa 60a promovió la germinación de esporangios, mientras que la 40g la inhibió. El estudio aleatorio de 150 plantas del lote cultivado, mostró una incidencia de 100 y una severidad de 9,9 hojas/planta y 13,8 dm2 de superficie foliar/planta, al cabo de 91 días. Rationale: la lechuga (Lactuca sativa) es el primer cultivo hortícola intensivo en la provincia de Buenos Aires, con un área sembrada de 5134 ha aproximadamente. Una de las principales causas de pérdida de la producción es la enfermedad ocasionada por Bremia lactucae, un biótrofo obligado, perteneciente al grupo de los Oomycetes. Considerando los reportes previos de actividad biológica de metabolitos provenientes de cepas de Nostoc muscorun, se consideró de interés evaluar el comportamiento de este patógeno frente a diferentes extractos de esta cianobacteria

Deep lithospheric structures along the southern central Chile Margin from wide-angle P-wave modellilng

Crustal- and upper-mantle structures of the subduction zone in south central Chile, between 42 degrees S and 46 degrees S, are determined from seismic wide-angle reflection and refraction data, using the seismic ray tracing method to calculate minimum parameter models. Three profiles along differently aged segments of the subducting Nazca Plate were analysed in order to study subduction zone structure dependencies related to the age, that is, thermal state, of the incoming plate. The age of the oceanic crust at the trench ranges from 3 Ma on the southernmost profile, immediately north of the Chile triple junction, to 6.5 Ma old about 100 km to the north, and to 14.5 Ma old another 200 km further north, off the Island of Chiloe. Remarkable similarities appear in the structures of both the incoming as well as the overriding plate. The oceanic Nazca Plate is around 5 km thick, with a slightly increasing thickness northward, reflecting temperature changes at the time of crustal generation. The trench basin is about 2 km thick except in the south where the Chile Ridge is close to the deformation front and only a small, 800-m-thick trench infill could develop. In south central Chile, typically three quarters (1.5 km) of the trench sediments subduct below the decollement in the subduction channel. To the north and south of the study area, only about one quarter to one third of the sediments subducts, the rest is accreted above. Similarities in the overriding plate are the width of the active accretionary prism, 35-50 km, and a strong lateral crustal velocity gradient zone about 75-80 km landward from the deformation front, where landward upper-crustal velocities of over 5.0-5.4 km s&lt;SU-1&lt;/SU decrease seaward to around 4.5 km s&lt;SU-1&lt;/SU within about 10 km, which possibly represents a palaeo-backstop. This zone is also accompanied by strong intraplate seismicity. Differences in the subduction zone structures exist in the outer rise region, where the northern profile exhibits a clear bulge of uplifted oceanic lithosphere prior to subduction whereas the younger structures have a less developed outer rise. This plate bending is accompanied by strongly reduced rock velocities on the northern profile due to fracturing and possible hydration of the crust and upper mantle. The southern profiles do not exhibit such a strong alteration of the lithosphere, although this effect may be counteracted by plate cooling effects, which are reflected in increasing rock velocities away from the spreading centre. Overall there appears little influence of incoming plate age on the subduction zone structure which may explain why the M-w = 9.5 great Chile earthquake from 1960 ruptured through all these differing age segments. The rupture area, however, appears to coincide with a relatively thick subduction channel