3,551 research outputs found
Low-temperature anomalies of a vapor deposited glass
We investigate the low temperature properties of two-dimensional
Lennard-Jones glass films, prepared in silico both by liquid cooling and by
physical vapor deposition. We identify deep in the solid phase a crossover
temperature , at which slow dynamics and enhanced heterogeneity emerge.
Around , localized defects become visible, leading to vibrational
anomalies as compared to standard solids. We find that on average,
decreases in samples with lower inherent structure energy, suggesting that such
anomalies will be suppressed in ultra-stable glass films, prepared both by very
slow liquid cooling and vapor deposition.Comment: 10 pages including appendices, 8 figures. Version accepted for
Physical Review Material
q-State Potts model metastability study using optimized GPU-based Monte Carlo algorithms
We implemented a GPU based parallel code to perform Monte Carlo simulations
of the two dimensional q-state Potts model. The algorithm is based on a
checkerboard update scheme and assigns independent random numbers generators to
each thread. The implementation allows to simulate systems up to ~10^9 spins
with an average time per spin flip of 0.147ns on the fastest GPU card tested,
representing a speedup up to 155x, compared with an optimized serial code
running on a high-end CPU. The possibility of performing high speed simulations
at large enough system sizes allowed us to provide a positive numerical
evidence about the existence of metastability on very large systems based on
Binder's criterion, namely, on the existence or not of specific heat
singularities at spinodal temperatures different of the transition one.Comment: 30 pages, 7 figures. Accepted in Computer Physics Communications.
code available at:
http://www.famaf.unc.edu.ar/grupos/GPGPU/Potts/CUDAPotts.htm
Rhinoxenus (Dactylogyridae) parasitizing piranhas (Serrasalmidae) at its southernmost limit of distribution (Paraná River, Argentina), with the description of two new species
Three piranha species, Serrasalmus maculatus, S. marginatus and Pygocentrus nattereri, living sympatrically in the lower Paraná River (Argentina) were examined searching for nasal monogeneans to know its diversity and distribution. Four species of monogeneans belonging to Rhinoxenus were found parasitizing the nasal cavities. Two new species are described, and new morphological data of 2 previously described species is provided. Rhinoxenus argentinensis n. sp. is characterized by having the male copulatory organ (MCO) as a coiled tube with a reel shaped-base; an elongated accessory piece articulated to base of MCO; a sinistral vagina with a sclerotized vestibule, and a sclerotized cap of the ventral anchor laterally modified forming a triangular expansion. Rhinoxenus paranaensis n. sp. is characterized by having a MCO as a coiled tube with a reel-shaped base; an accessory piece with an elongate proximal portion, a dilated distal portion with digitiform projections articulated to base of MCO; a sinistral vagina with 5-6 cuticular spine-shaped processes, and a sclerotized cap of the ventral anchor modified laterally forming a bilobate expansion. Additionally, multivariate discriminant analyses showed significant morphometric differences in the ventral anchors among Rhinoxenus species parasitizing ‘piranhas’.Fil: Rossin, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: de Francesco, Pablo Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Irigoitia, Manuel Marcial. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Scarabotti, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Taglioretti, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin
Maintenance of photosynthetic capacity in flooded tomato plants with reduced ethylene sensitivity
Ethylene is considered one of the most important plant hormones orchestrating plant responses to flooding stress. However, ethylene may induce deleterious effects on plants, especially when produced at high rates in response to stress. In this paper, we explored the effect of attenuated ethylene sensitivity in the Never ripe (Nr) mutant on leaf photosynthetic capacity of flooded tomato plants. We found out that reduced ethylene perception in Nr plants was associated with a more efficient photochemical and non-photochemical radiative energy dissipation capability in response to flooding. The data correlated with the retention of chlorophyll and carotenoids content in flooded Nr leaves. Moreover, leaf area and specific leaf area were higher in Nr, indicating that ethylene would exert a negative role in leaf growth and expansion under flooded conditions. Although stomatal conductance was hampered in flooded Nr plants, carboxylation activity was not affected by flooding in the mutant, suggesting that ethylene is responsible for inducing non-stomatal limitations to photosynthetic CO2 uptake. Upregulation of several cysteine protease genes and high protease activity led to Rubisco protein loss in response to ethylene under flooding. Reduction of Rubisco content would, at least in part, account for the reduction of its carboxylation efficiency in response to ethylene in flooded plants. Therefore, besides its role as a trigger of many adaptive responses, perception of ethylene entails limitations in light and dark photosynthetic reactions by speeding up the senescence process that leads to a progressive disassembly of the photosynthetic machinery in leaves of flooded tomato plants.Fil: de Pedro, Leandro Federico. Universidad Nacional de Formosa. Facultad de la Producción y El Medioambiente; ArgentinaFil: Mignolli, Francesco. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Scartazza, Andrea. Consiglio Nazionale delle Ricerche; ItaliaFil: Melana Colavita, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Bouzo, Carlos Alberto. Universidad Nacional del Litoral; ArgentinaFil: Vidoz, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin
Global, regional, and national trends in haemoglobin concentration and prevalence of total and severe anaemia in children and pregnant and non-pregnant women for 1995–2011: a systematic analysis of population-representative data
Background Low haemoglobin concentrations and anaemia are important risk factors for the health and development
of women and children. We estimated trends in the distributions of haemoglobin concentration and in the prevalence
of anaemia and severe anaemia in young children and pregnant and non-pregnant women between 1995 and 2011.
Methods We obtained data about haemoglobin and anaemia for children aged 6–59 months and women of
childbearing age (15–49 years) from 257 population-representative data sources from 107 countries worldwide. We
used health, nutrition, and household surveys; summary statistics from WHO’s Vitamin and Mineral Nutrition
Information System; and summary statistics reported by other national and international agencies. We used a
Bayesian hierarchical mixture model to estimate haemoglobin distributions and systematically addressed missing
data, non-linear time trends, and representativeness of data sources. We quantifi ed the uncertainty of our estimates.
Findings Global mean haemoglobin improved slightly between 1995 and 2011, from 125 g/L (95% credibility interval
123–126) to 126 g/L (124–128) in non-pregnant women, from 112 g/L (111–113) to 114 g/L (112–116) in pregnant
women, and from 109 g/L (107–111) to 111 g/L (110–113) in children. Anaemia prevalence decreased from 33% (29–37)
to 29% (24–35) in non-pregnant women, from 43% (39–47) to 38% (34–43) in pregnant women, and from 47%
(43–51) to 43% (38–47) in children. These prevalences translated to 496 million (409–595 million) non-pregnant
women, 32 million (28–36 million) pregnant women, and 273 million (242–304 million) children with anaemia in
2011. In 2011, concentrations of mean haemoglobin were lowest and anaemia prevalence was highest in south Asia
and central and west Africa.
Interpretation Children’s and women’s haemoglobin statuses improved in some regions where concentrations had
been low in the 1990s, leading to a modest global increase in mean haemoglobin and a reduction in anaemia
prevalence. Further improvements are needed in some regions, particularly south Asia and central and west Africa, to
improve the health of women and children and achieve global targets for reducing anaemia.
Funding Bill & Melinda Gates Foundation, Grand Challenges Canada, and the UK Medical Research Council
Systemic thrombotic microangiopathy associated with complement pathway mutations in living donor kidney transplant: case report
El síndrome urémico hemolítico (SUH) se caracteriza por la presencia de anemia hemolítica,plaquetopenia e insuficiencia renal aguda. Si bien se distingue clásicamente en típico o infeccioso y atípico, es menester reconocer situacionesclínicas en las que se pone de manifiesto, como por ejemplo, embarazo, puerperio inmediato,tumores, trasplante, drogas, etc., condiciones clínicas que han sido denominadas amplificadoras del complemento.La recurrencia postrasplante del síndrome urémico hemolítico atípico (SUHa) ha sido descrita en porcentajes variables en pacientes con mutaciones del factor H, factor B, factor I y C3, y gen de la trombomodulina, en reportes de casos aislados. Se presenta el caso de una paciente con enfermedad renal crónica (ERC) secundaria a agenesia renal, receptora preemptive de un riñón de donante vivo relacionado que presentó disfunción del injerto renal secundaria a microangiopatía trombótica, asociado acomplicación neurológica, hemorragias, disfunción orgánica múltiple y óbito. Se describen los hallazgos del estudio genético yanatomopatológico de necropsia.Hemolytic uremic syndrome (HUS) is characterized by the presence of hemolytic anemia, thrombocytopenia and acute kidney injury. Although it is usually distinguished as typical or infectious and atypical, it is necessary to recognize clinical situations in which it is revealed, such as pregnancy, immediate postpartum period, tumors, transplantation, drugs, etc., i.e. clinical conditions that have been called complement-amplifying conditions. Post-transplantation recurrence of atypical hemolytic uremic syndrome (aHUS) has been described in variable percentages in patients with mutations of factor H, factor B, factor I and C3, and thrombomodulin gene, in reports of isolated cases. We present the case of a patient with chronic kidney disease (CKD) secondary to renal agenesis, a preemptive recipient of a related living donor kidney, which presented renal graft dysfunction secondary to thrombotic microangiopathy, associated with neurological complications, hemorrhages, multiple organ dysfunction and death. The findings of the genetic and pathological autopsy study are described.Fil: Gutierrez, Roberto. Fundación Favaloro; ArgentinaFil: Fortunato, Rita Marcela. Fundación Favaloro; ArgentinaFil: Vigliano, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Espinoza, Álvaro. Fundación Favaloro; ArgentinaFil: Nava, Alison. Fundación Favaloro; ArgentinaFil: De Francesco, Juan. Fundación Favaloro; ArgentinaFil: Raffaele, Pablo Miguel. Fundación Favaloro; Argentin
Reliability of enzyme assays in dried blood spots for diagnosis of 4 lysosomal storage disorders
Introduction: Lysosomal storage disorders (LSD) are inherited diseases caused, in the majority of them, by the deficiency of lysosomal enzymatic activities. Ob-jectives: We aimed to analyze the usefulness of DBS samples for diagnosis of 4 LSDs, with the availability of a large quantity of patient samples. Design and methods: Blood samples from previously diagnosed patients with Fabry, Gaucher, Hunter, and Maro-teaux-Lamy syndromes and normal control indi-viduals, were collected and dispen-sed in filter paper, and used for enzymatic activity determination. Re-sults: Diagnosis of hemi/homo-zygous patients with Fabry, Hunter and Maroteaux-Lamy diseases using DBS samples showed ideal parameters of 100% sen-sitivity and specificity. DBS assay for Gaucher dis-ease would need a posterior confirmatory step. Con-clusions: Leukocyte measu-rement is the only reli-able way to diagnose Gaucher disease. For Hunter, Fabry and Maroteaux-Lamy disorders discrimina-tion between patients and controls seems adequate by DBS.Laboratorio de Investigaciones del Sistema Inmun
Alteraciones en proteínas asociadas al manejo del calcio intracelular en corazón del modelo murino de enfermedad de Fabry
La Enfermedad de Fabry es una patología de almacenamiento lisosomal genética que entre varios órganos, afecta también al tejido cardíaco. Resultados previos de nuestro grupo revelaron menor contractilidad del ventrículo izquierdo, de músculos papilares y de miocitos aislados, asociado a menor amplitud del transitorio de calcio (Ca2+) en el modelo murino de Enfermedad de Fabry (knockout para el gen de alfagalactosidasa A) (RF) en comparación con los de la cepa salvaje (RWT). El objetivo del presente trabajo es analizar el estado de las proteínas asociadas a la homeostasis del Ca2+ miocárdico en corazones de ratones RF y RWT.Facultad de Ciencias Médica
Evaluación de la disfunción cardíaca en el modelo murino de enfermedad de Fabry
Los objetivos del presente trabajo son analizar la función cardíaca mediante ecocardiograma y la actividad contráctil de músculos papilares aislados y cardiomiocitos del corazón de ratones Fabry (RF) en comparación con los de cepa salvaje (RWT).Facultad de Ciencias Médica
LALINET: The First Latin American–Born Regional Atmospheric Observational Network
Sustained and coordinated efforts of lidar teams in Latin America at the beginning of the 21st century have built LALINET (Latin American Lidar NETwork), the only observational network in Latin America created by the agreement and commitment of Latin American scientists. They worked with limited funding but an abundance of enthusiasm and commitment toward their joint goal. Before LALINET, there were a few pioneering lidar stations operating in Latin America, described briefly here. Bi-annual Latin American Lidar Workshops, held from 2001 to the present, supported both the development of the regional lidar community and LALINET. At those meetings, lidar researchers from Latin America meet to conduct regular scientific and technical exchanges among themselves and with experts from the rest of the world. Regional and international scientific cooperation has played an important role for the development of both the individual teams and the network. The current LALINET status and activities are described, emphasizing the processes of standardization of the measurements, methodologies, calibration protocols, and retrieval algorithms. Failures and successes achieved in the buildup of LALINET are presented. In addition, the first LALINET joint measurement campaign and a set of aerosol extinction profile measurements obtained from the aerosol plume produced by the Calbuco volcano eruption on April 22, 2015, are described and discussed.Fil: Antuña Marrero, Juan Carlos. Centro Meteorológico de Camagüey; CubaFil: Landulfo, Eduardo. Instituto de Pesquisas Energéticas e Nucleares; BrasilFil: Estevan, René. Centro Meteorológico de Camagüey; CubaFil: Barja, Boris. Centro Meteorológico de Camagüey; Cuba. Universidade de Sao Paulo; BrasilFil: Robock, Alan. State University of New Jersey; Estados UnidosFil: Wolfram, Elian Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Ristori, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Clemesha, Barclay. Upper Atmosphere Research Group; BrasilFil: Zaratti, Francesco. Universidad Mayor de San Andrés; BoliviaFil: Forno, Ricardo. Universidad Mayor de San Andrés; BoliviaFil: Armandillo, Errico. ESTEC; Países BajosFil: Bastidas, Álvaro E.. Universidad Nacional de Colombia. Sede Medellin; ColombiaFil: de Frutos Baraja, Ángel Máximo. Universidad de Valladolid; EspañaFil: Whiteman, David N.. National Aeronautics and Space Administration; Estados UnidosFil: Quel, Eduardo Jaime. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Barbosa, Henrique M. J.. Universidade de Sao Paulo; BrasilFil: Lopes, Fabio. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energeticas e Nucleares.; BrasilFil: Montilla-Rosero, Elena. Universidad de Concepción; Chile. Universidad Escuela de Administración, Finanzas e Instituto Tecnológico; ColombiaFil: Guerrero Rascado, Juan L.. Comissao Nacional de Energia Nuclear. Centro de Lasers e Aplicacoes. Instituto de Pesquisas Energeticas e Nucleares.; Brasil. Universidad de Granada; Españ
- …