1,355 research outputs found
Formation and evaluation of the filterability of aerobic granules in a granular sludge membrane bioreactor
The technologies of aerobic granular sludge sequencing batch reactor (SBR) and membrane bioreactor (MBR) were combined in an attempt to develop an aerobic granular sludge membrane bioreactor (GMBR). The objectives were to determine the mechanisms controlling the formation of granules and granule stability in the GMBR as well as to evaluate the filterability of the granular sludge. The GMBR was operated in parallel with a SBR. In the SBR granulation was achieved after 16 days while no granulation was observed in the GMBR even after 10 weeks of operation. Filterability of the GMBR biomass, which was dominated by flocs, was compared with the filterability of granules cultivated in the SBR. The results showed no significant difference in filterability of granular sludge versus flocular sludge. Also, the clean water flux obtained after filtering flocular sludge was higher than after filtering granular sludge, suggesting that irreversible membrane fouling caused by adsorption of soluble extracellular polymeric substances (sEPS) was more important in the granules than in the flocs. According to the results of this study, granular sludge might not be able to alleviate the membrane fouling problem in MBRs. Furthermore, it could lead to irreversible membrane fouling in a major extent than that produced by conventional flocular sludge
Technology adoption and the investment climate : firm-level evidence for Eastern Europe and Central Asia
The international diffusion of technology presents an opportunity for developing economies distant from the world technological frontier to reduce their income gap relative to advanced economies. It is therefore crucial to understand why, when faced with similar technological alternatives different firms in different countries choose to adopt different vintages of capital. This paper examines technology adoption across firms in Eastern Europe and Central Asia. The findings show that access to complementary inputs - managerial capacity, skilled labor, finance, and good infrastructure - and to international knowledge - through foreign direct investment or exports - is an important correlate of technology adoption. The link between market incentives and technology adoption is more nuanced. Although consumer pressure results in technology adoption, competitor pressure does not, suggesting that only firms with rents are able to adopt technology given substantial resource constraints. Privatized firms exhibit better technology adoption outcomes but only when a clear private owner with a profit incentive is present. Better governance is associated with technology adoption only in the countries that joined the European Union in 2004. Future increases in technology adoption by firms in the region will require complementary reforms of the investment climate.E-Business,Technology Industry,ICT Policy and Strategies,Microfinance,
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Centrolene savagei
Number of Pages: 11Geological SciencesIntegrative Biolog
Politización del sufrimiento. Aproximación desde procesos de investigación e intervención
El proyecto de indagación “Producción de sentidos y subjetividad en el espacio
carcelar” examina y analiza en los acontecimientos generados la interferencia
de política de derechos humanos en la institución cárcel. Reconociendo desde las narrativas de los sujetos en su posición subjetiva y social, la disputa de
sentidos y resistencia y límites al poder del Estado. Algo de lo instituido ya
no funciona como se espera o debiera según la lógica unívoca carcelaria y, el
dolor soportado se hace audible públicamente interpelando saberes naturalizados, conceptos disciplinares, dispositivos y prácticas. El sufrimiento expresa
la diferencia y la multiplicidad de sentidos en el encierro. Un sufrimiento que
se derrama en lo social fuera de los muros a las redes de familias, allegados,
profesionales, educadores, otros interpelando lo negativo de la existencia de
ciertos sujetos capturados por la selectividad del sistema penal. Dar visibilidad
al sufrimiento posibilitará cartografiar las intensidades del derrame del control
social punitivo como operatoria de gubernamentalidad de la excedencia y, así
mismo, se posibilitará al hacer del dolor personal una cuestión pública un trabajo crítico de distinción entre el sufrimiento inevitable y el sufrimiento evitable (inadmisible), indagar las condiciones y atribuir responsabilidades.Fil: Correa, Ana M. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Centro de Investigaciones María Saleme de Burnichon; Argentina.Fil: Correa, Ana M. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina
Gating of the Bacterial Sodium Channel, NaChBac: Voltage-dependent Charge Movement and Gating Currents
The bacterial sodium channel, NaChBac, from Bacillus halodurans provides an excellent model to study structure–function relationships of voltage-gated ion channels. It can be expressed in mammalian cells for functional studies as well as in bacterial cultures as starting material for protein purification for fine biochemical and biophysical studies. Macroscopic functional properties of NaChBac have been described previously (Ren, D., B. Navarro, H. Xu, L. Yue, Q. Shi, and D.E. Clapham. 2001. Science. 294:2372–2375). In this study, we report gating current properties of NaChBac expressed in COS-1 cells. Upon depolarization of the membrane, gating currents appeared as upward inflections preceding the ionic currents. Gating currents were detectable at −90 mV while holding at −150 mV. Charge–voltage (Q–V) curves showed sigmoidal dependence on voltage with gating charge saturating at −10 mV. Charge movement was shifted by −22 mV relative to the conductance–voltage curve, indicating the presence of more than one closed state. Consistent with this was the Cole-Moore shift of 533 μs observed for a change in preconditioning voltage from −160 to −80 mV. The total gating charge was estimated to be 16 elementary charges per channel. Charge immobilization caused by prolonged depolarization was also observed; Q–V curves were shifted by approximately −60 mV to hyperpolarized potentials when cells were held at 0 mV. The kinetic properties of NaChBac were simulated by simultaneous fit of sodium currents at various voltages to a sequential kinetic model. Gating current kinetics predicted from ionic current experiments resembled the experimental data, indicating that gating currents are coupled to activation of NaChBac and confirming the assertion that this channel undergoes several transitions between closed states before channel opening. The results indicate that NaChBac has several closed states with voltage-dependent transitions between them realized by translocation of gating charge that causes activation of the channel
Oral alterations and oral care in bone marrow transplant patients
Os cuidados gerais relativos ao paciente submetido ao transplante de medula óssea (TMO) incluem avaliações odontológicas rotineiras, as quais devem estar inseridas em um contexto multiprofissional. A cavidade oral constitui um sítio propício a infecções com grande potencial de desenvolvimento de bacteremia, sendo que lesões infecciosas devem ser previamente tratadas e controladas pelo cirurgião-dentista. O objetivo desta revisão é discutir questões em destaque na literatura nacional e internacional referentes aos quadros inflamatórios e infecciosos orais de importância para o paciente transplantado de medula óssea, tanto os predisponentes a complicações durante o transplante, quanto os que ocorrem durante e após a terapia mielossupressora. Destaca-se na literatura a doença periodontal avançada, a qual constitui um quadro infeccioso crônico que deve ser evitado ou controlado durante o TMO, principalmente devido à presença de S. viridans. Os fatores de risco para mucosite oral (OM), doença do enxerto contra o hospedeiro (DECH) e xerostomia ainda não estão definidos, principalmente para OM e DECH. São citadas na literatura alternativas promissoras de tratamento para OM, tais como crioterapia, administração de fatores de crescimento e laserterapia. O risco aumentado de cárie é controverso e, dentre as lesões fúngicas e virais, destacam-se as infecções orais e de orofaringe por Candida e pela família de herpesvírus, de importância clínica considerável. Em pacientes pediátricos são relevantes as alterações craniofaciais e dentárias, decorrentes principalmente da radioterapia.General care in bone marrow transplant (BMT) patients includes routine dental evaluations, which must be included in a multi-professional context. The oral cavity is a site that favors infections with high potential for consequent bacteremia and so infectious lesions must be treated or controlled by the dentist. The aim of this review is to discuss key questions in national and international literature with reference to oral inflammatory conditions of BMT patients, both those with predisposition to complications during the transplant and those that emerge during and after myelosuppression therapy. The literature emphasizes advanced periodontal disease, which is a chronic infectious condition that must be avoided or controlled during BMT, particularly because of the presence of S. viridans. The risk factors for oral mucositis, graft-versus-host disease (GVHD) and xerostomia have not yet been defined, particularly for oral mucositis and GVHD. Promising alternatives in the treatment of oral mucositis, including cryotherapy, administration of growth factors and laser therapy, are emphatically mentioned. In children, craniofacial and dental alterations, particularly resulting from radiotherapy are relevant. The increased risk of caries is controversial, and among fungal and viral lesions, oral and oropharyngeal infections by Candida and the herpes virus are identified as being of considerable clinical importance
Differential renal effects of candesartan at high-and ultra-high doses in diabetic mice: potential role of ACE2/AT2R/Mas
High doses of Ang II receptor (AT1R) blockers (ARBs) are renoprotective in diabetes. Underlying mechanisms remain unclear. We evaluated whether high/ultra-high doses of candesartan (ARB) up-regulate angiotensin-converting enzyme 2 (ACE2)/Ang II type 2 receptor (AT2R)/Mas receptor [protective axis of the of the renin–angiotensin system (RAS)] in diabetic mice. Systolic blood pressure (SBP), albuminuria and expression/activity of RAS components were assessed in diabetic db/db and control db/+ mice treated with increasing candesartan doses (intermediate, 1 mg/kg/d; high, 5 mg/kg/d; ultra-high, 25 and 75 mg/kg/d; 4 weeks). Lower doses candesartan did not influence SBP, but ultra-high doses reduced SBP in both groups. Plasma glucose and albuminuria were increased in db/db compared with db/+ mice. In diabetic mice treated with intermediate dose candesartan, renal tubular damage and albuminuria were ameliorated and expression of ACE2, AT2R and Mas and activity of ACE2 were increased, effects associated with reduced ERK1/2 phosphorylation, decreased fibrosis and renal protection. Ultra-high doses did not influence the ACE2/AT2R/Mas axis and promoted renal injury with increased renal ERK1/2 activation and exaggerated fibronectin expression in db/db mice. Our study demonstrates dose-related effects of candesartan in diabetic nephropathy: intermediate–high dose candesartan is renoprotective, whereas ultra-high dose candesartan induces renal damage. Molecular processes associated with these effects involve differential modulation of the ACE2/AT2R/Mas axis: intermediate–high dose candesartan up-regulating RAS protective components and attenuating pro-fibrotic processes, and ultra-high doses having opposite effects. These findings suggest novel mechanisms through the protective RAS axis, whereby candesartan may ameliorate diabetic nephropathy. Our findings also highlight potential injurious renal effects of ultra-high dose candesartan in diabetes
Microbialite-like structures in Cladophora sp. (Ulvophyceae) mats from a subtropical Andean basin: ecological implications
The solubility equilibrium of calcite is influenced by physicochemical, climatic and biological factors. Annual cycles of exceptionally prolonged drought, in conjunction with naturally occurring diffuse organic pollution, generate the unique conditions for the precipitation of lithified carbonate structures (microbialites). The aim of this article is to analyze the possible implications of calcite precipitation produced in mats of Cladophora sp. in an Andean subtropical basin, considering it is the first time this phenomenon is described for the region. We collected samples from selected sites at the Lules River Basin, in four sampling dates between the years 2003 and 2004, within a monitoring work of 15 years. Samples were analyzed using an electron microscope and X-ray diffraction analysis. We found that Gomphonema sp. attached to Cladophora sp. contributes to precipitation of calcite and formation of microbialite like structures, in the studied area. This work presents an initial discussion of the discovery of microbialites-like structures attached to Cladophora sp. mats in a subtropical Andean stream and the environmental conditions that lead to their production, as well as the possible ecological implications of these microbialites.Fil: Fernandez, Hugo Rafael. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; ArgentinaFil: González Achem, Ana L.. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Invertebrados; ArgentinaFil: Correa, M.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Albarracín, Virginia Helena. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin
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