Edad, crecimiento, mortalidad e incidencia de las variaciones del nivel hidrométrico del río Paraná en la abundancia del surubí pintado (Pseudoplatystoma corruscans)

Los objetivos son determinar los parámetros de crecimiento, índice de mortalidad e incidencia de las variaciones del nivel hidrométrico en la abundancia de las poblaciones del surubí pintado. Se analizaron las tallas de 3.332 ejemplares capturados en 34 concursos de pesca desde 1996 a 2008. Participaron 32.766 pescadores que totalizaron 369.044 horas de pesca. Se dispuso información de pesquerías comerciales desde 1976. La edad y el crecimiento se determinaron en base a la descomposición de las polimodales de las pseudocohortes de los concursos de pesca Reconquista y Goya y se validaron con lecturas de las marcas anuales en los radios duros de las aletas pectorales. Los parámetros de la ecuación de von Bertalanffy determinados, fueron: L∞ de 185 cm, K: 0.0653; t0: - 3.4. El surubí nace en primavera-verano y marcan los anillos en invierno, el primero a los 6 meses. En el período de crecimiento a los 4+ años reabsorbe el primer anillo y luego a los 5+, 7+ y 9+ años con el segundo, tercero y cuarto anillo respectivamente. Las variaciones de la mortalidad (Z) se asocian a las capturas de sábalo. El análisis de la CPUE mostró la disminución de tallas superiores a la primera reproducción (91 cm). El porcentaje de reproductores en 1976-77 era del 63%, en el 2002-03 diminuyó al 30% y en los concursos de Goya y Reconquista desde el 2004, no supera el 11%. El mejor ajuste de los surubíes pintado de edad 4+ capturados en Goya y Reconquista (cohortes 1999 al 2004) se dio con el promedio del nivel hidrométrico de octubre a diciembre. Niveles hidrométricos más elevados producirían cohortes más abundantes.Age, growth, mortality and incidence of the variations of the Paraná River hydrometric level in abundance of "spotted sorubim" (Pseudoplatystoma corruscans). The goals are to determine the growth patterns, mortality rate and incidence of the hydrometric level variations in the abundance of Pseudoplatystoma corruscans populations. We analyzed the sizes of 3,332 fish caught in 34 fishing tournaments from 1996-2008. Age and growth were determined based on the decomposition of the pseudo-cohort polimodals of the Reconquista and Goya fishing tournaments and were validated with readings of the annual markers at the hard radius of the pectoral fin. The P. corruscans is born in spring-summer and marks the growing rings in winter, towards the first 6 months. During growing period to the 4+ years it reabsorbs the first mark and then towards the 5+, 7+ and 9+ years it reabsorbs with the second, third and fourth marks respectively. Mortality variations (Z) are related with Prochilodus lineatus captures. The percentage of breeders in 1976-77 was 63%, in the period 2002-03 it decreased to 30% and in the Goya and Reconquista tournaments since 2004, does not exceed 11%. The best adjustment of the 'spotted sorubim’ of 4+ years caught is Goya and Reconquista (1999-2004 cohorts) was achieved with the average hydrometric level on spring. Higher hydrometric levels would allow more abundant cohortsFil: Oldani, Norberto Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Ecclesia, Ovidio. Subdirección de Fauna y Flora de Corrientes; ArgentinaFil: Baigún, Claudio Rafael M.. Universidad Nacional de General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico Chascomús. Instituto de Investigaciones Biotecnológicas (sede Chascomús); Argentin

Study on ammonia transport and separation in Aquivion® perfluoro sulfonated acid membranes

The present study reports the results of a series of sorption and permeation tests of pure ammonia as well as nitrogen and hydrogen carried out on Aquivion C87-05 (short-side chain perfluoro sulfonic acid ionomer). Such material is indeed of interest for possible applications in sustainable processes for ammonia production, either as base material for polymer electrolyte membranes in low-temperature electrochemical ammonia synthesis or as a membrane for effective product separation. NH3, N2, and H2 permeation tests are performed at different temperatures (20, 35, and 50 ◦C) and both in dry and humid conditions (R.H. up to 80%), aiming to assess the influence of these parameters on the resulting permeabilities, while ammonia sorption is inspected at the same temperatures, and pressures up to near saturation conditions. Pure ammonia permeability reached outstanding values around 7000 Barrer in dry Aquivion membranes, revealing an increasing trend with upstream pressure, while it decreased with temperature. The same behavior is recorded for NH3 solubility, indicating that sorption drives the ammonia transport through the membrane. The obtained separation performances are found to be significantly better than those of other polymeric membranes proposed for the same separations, as compared to a permeability-selectivity plot

Fish passage system in an irrigation dam (Pilcomayo River basin): When engineering designs do not match ecohydraulic criteria.

The Route 28 Dam has the potential to block fish movements from La Estrella marsh to the Pilcomayo River. In addition, themany fish that concentrate immediately downstream of the dam may suffer high mortality when they are stranded duringlow water periods. The goals of this study are to determine if fish are able to pass the spillway and to assess if the designof the installed ladders (pool and weir type) effectively supports upstream migration of Prochilodus lineatus (sábalo).Results showed that only fish longer than 39 cm should be able to ascend the spillway chute, but when water levels on thespillway crest are over 0.4 m. Fish are also unable to jump from spillway toe to spillway crest because the downstreamdissipation pool does not meet the minimum depth criterion for fish to accelerate to sufficient velocity. Fish ladders haveinsufficient number of pools and some pool dimensions and designs depart from accepted standard designs. Volumetricdissipation power in the upper pool of each fish ladder is too low for fish to rest. Also, attraction flows relative to totalspillway discharge at the entrance to each fishway are insufficient. Fish passage failures of both the spillway and pool andweir systems in La Estrella marsh can be traced to the ?salmon-centric? concept used by the designers. We conclude thatthe Route 28 Dam design including its fish passage systems, do not follow criteria to cope with the strong hydrologicalvariability and bioecological characteristics of fish inhabiting pulsatile systems such as La Estrella marsh.Fil: Baigún, Claudio Rafael M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Nestler, John. University of Iowa; Estados UnidosFil: Minotti, Priscilla Gail. Universidad Nacional de San Martín; ArgentinaFil: Oldani, Norberto Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Machine learning approach to the safety assessment of a prestressed concrete railway bridge

Early structural anomalies identification allows to hold maintenance activities that avoid loss of both economic resources and human life. This is extremely important for crucial infrastructures like railway bridges. This paper illustrates the structural health monitoring approach applied to a simply supported prestressed concrete railway bridge. In the framework of long-term monitoring, both static quantities (displacements, strains, and rotations) and environmental measurements (temperatures) have been recorded. Machine learning techniques, Extreme Gradient boosting machine and Multi-Layer Perceptron, have been exploited to build regression correlation models associated with the undamaged structural condition after adequate pre-processing operations. In this way, alarm thresholds based on the expected residuals between the predicted structural quantities and the measured ones, have been defined. The thresholds turned out to be able to catch early-stage anomalies not pointed out by traditional damage thresholds based on the design values. The proposed damage index is chosen as the moving median of the residuals, allowing a significant reduction of false alarms. The used correlation models and the obtained results represent a starting point for the generalization of this approach to the bridges belonging to the same static typology

Chemically stabilised extruded and recast short side chain Aquivion proton exchange membranes for high current density operation in water electrolysis

Membrane-electrode assemblies based on chemically stabilised short-side-chain proton exchange Aquivion® membranes, prepared by extrusion or recast methods, have been investigated for operation at high current density (3-4 A cm -2 ) in water electrolysis cells. A thickness of 90 µm was selected for these perfluorosulfonic acid membranes in order to provide proper resilience to hydrogen crossover under differential pressure operation while allowing operation at high currents. The membranes showed proper mechanical strength for high-pressure operation and suitable conductivity to reduce ohmic losses at high current densities. Both membranes showed excellent performance in electrolysis cells by achieving a voltage efficiency better than 85% and 80% (1.85 V) at 3 and 4 A cm -2 , respectively, in polarisation curves at 90 °C. A smaller surface roughness was observed from atomic force microscopy for the recast membrane compared to the extruded one. This may affect the intimate contact between the ionic clusters of the membrane and the catalyst agglomerate at the interface producing a catalytic enhancement in the activation region of the polarisation curves in the case of the recast membrane. At high cell voltages, the polarisation resistance was instead slightly lower for the cell based on the extruded membrane. Interestingly, the different characteristics of the membrane-electrodes interface produced lower recoverable losses in durability studies for the recast membrane-based electrolyser allowing stable operation at both 3 and 4 A cm -2 . Hydrogen crossover analysis at a differential pressure of 20 bar showed low gas permeation through both membranes allowing for a wide load range (15-100 %) and high faradaic efficiency >99% at practical current densities (1-4 A cm -2 )

Pre-retrieval reperfusion decreases cancer recurrence after rat ischemic liver graft transplantation

Background & Aims Liver transplantation from marginal donors is associated with ischemia/reperfusion (I/R) lesions, which may increase the risk of post-transplant hepatocellular carcinoma (HCC) recurrence. Graft reperfusion prior to retrieval (as for extracorporeal membrane oxygenation – ECMO) can prevent I/R lesions. The impact of I/R on the risk of cancer recurrence was assessed on a syngeneic Fischer-rat liver transplantation model. Methods HCC cells were injected into the vena porta of all recipients at the end of an orthotopic liver transplantation (OLT). Control donors were standard heart-beating, ischemic ones (ISC), underwent 10min or 30min inflow liver clamping prior to retrieval, and ischemic/reperfused (ISC/R) donors underwent 2h liver reperfusion after the clamping. Results I/R lesions were confirmed in the ISC group, with the presence of endothelial and hepatocyte injury, and increased liver function tests. These lesions were in part reversed by the 2h reperfusion in the ISC/R group. HCC growth was higher in the 10min and 30min ISC recipients ( p =0.018 and 0.004 vs. control, as assessed by MRI difference between weeks one and two), and was prevented in the ISC/Rs ( p =0.04 and 0.01 vs. ISC). These observations were associated with a stronger pro-inflammatory cytokine profile in the ISC recipients only, and the expression of hypoxia and HCC growth-enhancer genes, including Hmox1 , Hif1a and Serpine1 . Conclusions This experiment suggests that ischemia/reperfusion lesions lead to an increased risk of post-transplant HCC recurrence and growth. This observation can be reversed by graft reperfusion prior to retrieval

Accuracy of self-assessment of real-life functioning in schizophrenia

A consensus has not yet been reached regarding the accuracy of people with schizophrenia in self-reporting their real-life functioning. In a large (n=618) cohort of stable, community-dwelling schizophrenia patients we sought to: (1) examine the concordance of patients' reports of their real-life functioning with the reports of their key caregiver; (2) identify which patient characteristics are associated to the differences between patients and informants. Patient-caregiver concordance of the ratings in three Specific Level of Functioning Scale (SLOF) domains (interpersonal relationships, everyday life skills, work skills) was evaluated with matched-pair t tests, the Lin's concordance correlation, Somers' D, and Bland-Altman plots with limits of agreement (LOA). Predictors of the patient-caregiver differences in SLOF ratings were assessed with a linear regression with multivariable fractional polynomials. Patients' self-evaluation of functioning was higher than caregivers' in all the evaluated domains of the SLOF and 17.6% of the patients exceeded the LOA, thus providing a self-evaluation discordant from their key caregivers. The strongest predictors of patient-caregiver discrepancies were caregivers' ratings in each SLOF domain. In clinically stable outpatients with a moderate degree of functional impairment, self-evaluation with the SLOF scale can become a useful, informative and reliable clinical tool to design a tailored rehabilitation program

The interplay among psychopathology, personal resources, context-related factors and real-life functioning in schizophrenia: stability in relationships after 4 years and differences in network structure between recovered and non-recovered patients

Improving real-life functioning is the main goal of the most advanced integrated treatment programs in people with schizophrenia. The Italian Network for Research on Psychoses previously explored, by using network analysis, the interplay among illness-related variables, personal resources, context-related factors and real-life functioning in a large sample of patients with schizophrenia. The same research network has now completed a 4-year follow-up of the original sample. In the present study, we used network analysis to test whether the pattern of relationships among all variables investigated at baseline was similar at follow-up. In addition, we compared the network structure of patients who were classified as recovered at follow-up versus those who did not recover. Six hundred eighteen subjects recruited at baseline could be assessed in the follow-up study. The network structure did not change significantly from baseline to follow-up, and the overall strength of the connections among variables increased slightly, but not significantly. Functional capacity and everyday life skills had a high betweenness and closeness in the network at follow-up, as they had at baseline, while psychopathological variables remained more peripheral. The network structure and connectivity of non-recovered patients were similar to those observed in the whole sample, but very different from those in recovered subjects, in which we found few connections only. These data strongly suggest that tightly coupled symptoms/dysfunctions tend to maintain each other's activation, contributing to poor outcome in schizophrenia. Early and integrated treatment plans, targeting variables with high centrality, might prevent the emergence of self-reinforcing networks of symptoms and dysfunctions in people with schizophrenia

The interplay among psychopathology, personal resources, context-related factors and real-life functioning in schizophrenia: stability in relationships after 4 years and differences in network structure between recovered and non-recovered patients

Improving real-life functioning is the main goal of the most advanced integrated treatment programs in people with schizophrenia. The Italian Network for Research on Psychoses previously explored, by using network analysis, the interplay among illness-related variables, personal resources, context-related factors and real-life functioning in a large sample of patients with schizophrenia. The same research network has now completed a 4-year follow-up of the original sample. In the present study, we used network analysis to test whether the pattern of relationships among all variables investigated at baseline was similar at follow-up. In addition, we compared the network structure of patients who were classified as recovered at follow-up versus those who did not recover. Six hundred eighteen subjects recruited at baseline could be assessed in the follow-up study. The network structure did not change significantly from baseline to follow-up, and the overall strength of the connections among variables increased slightly, but not significantly. Functional capacity and everyday life skills had a high betweenness and closeness in the network at follow-up, as they had at baseline, while psychopathological variables remained more peripheral. The network structure and connectivity of non-recovered patients were similar to those observed in the whole sample, but very different from those in recovered subjects, in which we found few connections only. These data strongly suggest that tightly coupled symptoms/dysfunctions tend to maintain each other's activation, contributing to poor outcome in schizophrenia. Early and integrated treatment plans, targeting variables with high centrality, might prevent the emergence of self-reinforcing networks of symptoms and dysfunctions in people with schizophrenia