Electron bifurcation mechanism and homoacetogenesis explain products yields in mixed culture anaerobic fermentations

Anaerobic fermentation of organic wastes using microbial mixed cultures is a promising avenue to treat residues and obtain added-value products. However, the process has some important limitations that prevented so far any industrial application. One of the main issues is that we are not able to predict reliably the product spectrum (i.e. the stoichiometry of the process) because the complex microbial community behaviour is not completely understood. To address this issue, in this work we propose a new metabolic network of glucose fermentation by microbial mixed cultures that incorporates electron bifurcation and homoacetogenesis. Our methodology uses NADH balances to analyse published experimental data and evaluate the new stoichiometry proposed. Our results prove for the first time the inclusion of electron bifurcation in the metabolic network as a better description of the experimental results. Homoacetogenesis has been used to explain the discrepancies between observed and theoretically predicted yields of gaseous H2 and CO2 and it appears as the best solution among other options studied. Overall, this work supports the consideration of electron bifurcation as an important biochemical mechanism in microbial mixed cultures fermentations and underlines the importance of considering homoacetogenesis when analysing anaerobic fermentations

Estudio de la biocompatibilidad de una nueva aleación beta-titanio de bajo módulo de elasticidad

Peer Reviewe

Solving shallow-water systems in 2D domains using Finite Volume methods and multimedia SSE instructions

AbstractThe goal of this paper is to construct efficient parallel solvers for 2D hyperbolic systems of conservation laws with source terms and nonconservative products. The method of lines is applied: at every intercell a projected Riemann problem along the normal direction is considered which is discretized by means of well-balanced Roe methods. The resulting 2D numerical scheme is explicit and first-order accurate. In [M.J. Castro, J.A. García, J.M. González, C. Pares, A parallel 2D Finite Volume scheme for solving systems of balance laws with nonconservative products: Application to shallow flows, Comput. Methods Appl. Mech. Engrg. 196 (2006) 2788–2815] a domain decomposition method was used to parallelize the resulting numerical scheme, which was implemented in a PC cluster by means of MPI techniques.In this paper, in order to optimize the computations, a new parallelization of SIMD type is performed at each MPI thread, by means of SSE (“Streaming SIMD Extensions”), which are present in common processors. More specifically, as the most costly part of the calculations performed at each processor consists of a huge number of small matrix and vector computations, we use the Intel© Integrated Performance Primitives small matrix library. To make easy the use of this library, which is implemented using assembler and SSE instructions, we have developed a C++ wrapper of this library in an efficient way. Some numerical tests were carried out to validate the performance of the C++ small matrix wrapper. The specific application of the scheme to one-layer Shallow-Water systems has been implemented on a PC’s cluster. The correct behavior of the one-layer model is assessed using laboratory data

Validación de los procesos de determinación de estándares de interpretación (EE) para pruebas de rendimiento educativo

En este trabajo se presenta una revisión del estado de la cuestión acerca de los métodos para desarrollar procesos de validación de la determinación de Estándares en pruebas de rendimiento educativo. Se analiza el concepto de Validez de los Estándares, así como estrategias de validación, y algunos indicadores de juicio

Paraganglioma of Prostatic Origin

Introduction Paragangliomas are usually benign tumors arising from chromaffin cells located outside the adrenal gland. Prostatic paraganglioma is an unusual entity in adult patients, with only 10 cases reported in the medical literature. Case Report A 34-year-old male with a history of chronic prostatitis consulted for perineal pain. On digital rectal examination the prostate was enlarged and firm, without nodules. The PSA level was 0.8 ng/mL and the catecholamines in the urine were elevated. On ultrasound a retrovesical 9 cm mass of undetermined origin measuring was present. A PET-CT scan showed a pelvic lesion measuring 9 cm with moderate increase in glucidic metabolism localized in the area of the prostate. A biopsy of the prostate revealed a neuroendocrine tumor, possibly a prostatic paraganglioma. A body scintigraphy with MIBG I-123 ruled out the presence of metastases or multifocal tumor. A radical prostatectomy with excision of the pelvic mass was performed under adrenergic blockade. One year after surgery the patient is asymptomatic and disease free. Discussion/Conclusions Prostatic paraganglioma is a rare, usually benign tumor, which should be considered in the differential diagnosis of prostate tumors in young males. Its diagnosis is based on the determination of catecholamine in blood and 24-hour urine and in imaging studies principally scintigraphy with MIBG I-123. Diagnostic confirmation is by histopathological study. The treatment consists of radical resection under adrenergic blockade and volume expansion. Given the limited number of cases reported, it is difficult to establish prognostic factors. Malignancy is defined by clinical criteria, and requires life long follow-up

Evaluación de la eficacia de un programa integral de prevención secundaria de la enfermedad cardiovascular en atención primaria: estudio PREseAP

ObjetivosEvaluar la eficacia de un programa integral de prevención secundaria para reducir la morbimortalidad en los pacientes que han tenido una enfermedad cardiovascular, controlar los factores de riesgo y el cumplimiento de la medicación profiláctica para prevenir recurrencias y mejorar la calidad de vida de los pacientes con enfermedad cardiovascular.DiseñoEnsayo clínico aleatorizado por clusters, abierto, pragmático, en atención primaria.EmplazamientoUn total de 42 centros de salud de 8 comunidades autónomas del Estado español.ParticipantesVarones y mujeres hasta 85 años de edad, diagnosticados de enfermedad coronaria y/o accidente cerebrovascular y/o enfermedad vascular periférica en el último año, y que no presenten una enfermedad grave o terminal.IntervenciónSe aleatorizarán los centros de salud para seguir la atención habitual en los pacientes diagnosticados de enfermedad cardiovascular (grupo control) o para implantar un programa integral de prevención secundaria (grupo intervención).Mediciones principalesAcontecimientos letales atribuibles a enfermedad cardiovascular, acontecimientos no letales atribuibles a enfermedad cardiovascular, acontecimientos letales por cualquier causa y calidad de vida relacionada con la salud (SF-36).ObjectivesTo assess the efficacy of a comprehensive secondary prevention programme to reduce morbidity and mortality in patients who have suffered a cardiovascular (CV) event; to control CV risk factors and prophylactic treatment in order to prevent recurrence; and to improve the quality of life of patients with cardiovascular disease.DesignRandomised, pragmatic, open clinical trial in primary care.SettingA total of 42 primary care centres of 8 different areas in Spain.ParticipantsMen and women below 86 years old, diagnosed with coronary disease and/or stroke and/or peripheral vascular disease in the preceding year, and who have no serious or terminal disease.InterventionPrimary care centres will be randomised to following usual care (control group), or to following a comprehensive programme of secondary prevention (intervention group).Main measurementsCardiovascular fatal events, cardiovascular non-fatal events, total mortality and health-related quality of life (SF-36)

Reproduction in the externally brooding sea anemone Epiactis georgiana in the Antarctic Peninsula and the Weddell Sea

14 pages, 8 figures, 2 tablesExternal parental care is uncommon among actiniarians but common in Epiactis species. Here, several aspects of reproduction are analyzed for of one of them, Epiactis georgiana. Samples were collected in December, January, February, March, and April in the Antarctic Peninsula and the eastern Weddell Sea, during 1998, 2000, 2002, and 2003. Most sexually mature individuals of E. georgiana are male or female, but some are hermaphrodites. This is the first report of hermaphroditism in E. georgiana, which is the third species of the genus with this sexual pattern. The results suggest that oogenesis starts in December and that at least two generations of oocytes overlap; a third generation is often brooded externally. Putative fertilization is likely internal, and larvae and/or embryos are externally brooded on the distal part of the adult column until an advanced developmental stage. Apparently E. georgiana reproduces seasonally, probably releasing the embryos/larvae in the last months of the austral spring (December). Inter-individual variability was observed in gametogenesis. In addition, specimens from the Antarctic Peninsula were larger than those from the Weddell Sea. This study represents the first step in understanding the reproductive mode of E. georgianaSpecial thanks are addressed to Prof. Dr. Wolf Arntz (Alfred-Wegener-Institute, Bremerhaven, Germany) who made possible our participation in several Antarctic projects and cruises. We extend our acknowledgements to the officers and crew of the R/V Polarstern and many colleagues on board during the EASIZ, ANDEEP, and BENDEX cruises for their valuable assistance. Thanks to M. Conradi (Universidad de Sevilla) who collected a considerable amount of the material analyzed in this manuscript. Comments from M. Daly, D. Fautin, and an anonymous reviewer substantially improved this manuscript. Support was provided by a MCT-CSICgrant (I3P-BPD2001-1) to E. Rodríguez and Spanish CICYT projects: ANT97-1533-E, ANT98-1739-E, ANT99-1608-E, REN2001-4269-E/ANT, REN2003-04236, and CGL2004-20141-E. This is a contribution to the SCAR program, Ecology of the Antarctic Sea Ice Zone (EASIZ) and ANDEEP contribution 159Peer reviewe

Faunal behavior in response to near bottom water dynamics in a marine protected area (Cantabrian Sea, southern Bay of Biscay)

A set of lander deployments in a deep marine protected area (MPA; El Cachucho) combining environmental sensors and a baited camera provided insight on the relationship between faunal behavior and oceanographic dynamics. Landers were deployed at different depths, ranging from 500 to 960 m for a period of 24–26 h. A total of 10,989 photographs were downloaded and synchronized using a time code with all the environmental variables recorded (pressure, temperature, salinity, water current, and direction). Total richness accounted for 41 species of different taxonomic groups (21 fishes, 11 crustaceans, 6 echinoderms, and 3 molluscs). The most abundant species were Synaphobranchus kaupii, Mora moro, Phycis blennoides, Helicolenus dactylopterus, and Etmopterus spinax. Arrival times (Tarr) and maximum number of individuals (Nmax) greatly differed among stations. Cluster analysis showed two main faunal groups in relation to depth: those close to the top of the bank and those in the flanks. Species densities were estimated using Priede's equations and compared with those obtained in previous studies using trawl samplers. The relation of species with environmental variables showed high variability depending on the location of the station and the associated variables (depth, current, and water masses). Near-bottom dynamics were consistent with previously known oceanographic patterns at the bank, dominated by background anticyclonic recirculation along the flanks overlaid by strong tidal cycles. Current and hydrography tidally driven phases showed an evident effect in the arrival of species at some locations. Species appeared during specific periods matching the beginning of the flooding phase or end of the ebb phase. Movement rates (cm s−1) were estimated for some invertebrate species, such as crabs (Bathynectes maravigna, 0.66; Pagurus sp., 0.09), the gasteropod Colus gracilis (0.15), and echinoderms (Cidaris cidaris, 0.04; Araeosoma fenestratum, 0.23)