966 research outputs found
Strategic decision making under climate change: a case study on Lake Maggiore water system
Abstract. Water resources planning processes involve different kinds of decisions that are generally evaluated under a stationary climate scenario assumption. In general, the possible combinations of interventions are mutually compared as single alternatives. However, the ongoing climate change requires us to reconsider this approach. Indeed, what have to be compared are not individual alternatives, but families of alternatives, characterized by the same structural decisions, i.e. by actions that have long-term effects and entail irrevocable changes in the system. The rationale is that the structural actions, once they have been implemented, cannot be easily modified, while the management decisions can be adapted to the evolving conditions. This paper considers this methodological problem in a real case study, in which a strategic decision has to be taken: a new barrage was proposed to regulate Lake Maggiore outflow, but, alternatively, either the present barrage can be maintained with its present regulation norms or with a new one. The problem was dealt with by multi-criteria decision analysis involving many stakeholders and two decision-makers. An exhaustive set of indicators was defined in the participatory process, conducted under the integrated water resource management paradigm, and many efficient (in Pareto sense) regulation policies were identified. The paper explores different formulations of a global index to evaluate and compare the effectiveness of the classes of alternatives under both stationary and changing hydrological scenarios in order to assess their adaptability to the ongoing climate change
Double-compartment culture system for conditioning vascular grafts with different trans-wall oxygen levels
Mid-term results of complex distal humeral fractures.
The aim of this study was to assess outcomes
following open reduction and internal fixation in complex
fractures of the distal humerus. Between 2000 and 2006, 34
patients were operated for complex fractures of the distal
humerus. Bone fixation was obtained with a reverse
Y-shaped reconstruction plate in 13 cases and with double
plating in 21 cases. At final follow-up, all the patients were
assessed with the Mayo Elbow Performance Score. Satisfactory
results were observed in 71% of the cases despite a
high rate of complications. Age over 65 years is correlated
with increased risk for an inferior postoperative result.
Complex distal humeral fractures are difficult to treat and
are associated with a high incidence of complications. It is
therefore mandatory to obtain good anatomical reduction
and a stable fixation of lateral and medial columns of the
distal humerus. The results observed in older patients
suggest that an alternative treatment for these patients may
be joint replacement
The Two-Component System CopRS Maintains Subfemtomolar Levels of Free Copper in the Periplasm of Pseudomonas aeruginosa Using a Phosphatase-Based Mechanism
Two-component systems control periplasmic Cu1 homeostasis in Gramnegative bacteria. In characterized systems such as Escherichia coli CusRS, upon Cu1 binding to the periplasmic sensing region of CusS, a cytoplasmic phosphotransfer domain of the sensor phosphorylates the response regulator CusR. This drives the expression of efflux transporters, chaperones, and redox enzymes to ameliorate metal toxic effects. Here, we show that the Pseudomonas aeruginosa two-component sensor histidine kinase CopS exhibits a Cu-dependent phosphatase activity that maintains CopR in a nonphosphorylated state when the periplasmic Cu levels are below the activation threshold of CopS. Upon Cux+ binding to the sensor, the phosphatase activity is blocked and the phosphorylated CopR activates transcription of the CopRS regulon. Supporting the model, mutagenesis experiments revealed that the ΔcopS strain exhibits maximal expression of the CopRS regulon, lower intracellular Cux+ levels, and increased Cu tolerance compared to wild-type cells. The invariant phosphoacceptor residue Hisx235 of CopS was not required for the phosphatase activity itself but was necessary for its Cu dependency. To sense the metal, the periplasmic domain of CopS binds two Cux+ ions at its dimeric interface. Homology modeling of CopS based on CusS structure (four Agx+ binding sites) clearly supports the different binding stoichiometries in the two systems. Interestingly, CopS binds Cux+/2+ with 3Ă—10x-14 M affinity, pointing to the absence of free (hydrated) Cux+/2+ in the periplasm.Fil: Novoa Aponte, Lorena. Worcester Polytechnic Institute. Departmen Of Chemistry And Biochemistry; Estados UnidosFil: Xu, Cheng. Worcester Polytechnic Institute. Departmen Of Chemistry And Biochemistry; Estados UnidosFil: Soncini, Fernando Carlos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de BiologĂa Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Instituto de BiologĂa Molecular y Celular de Rosario; ArgentinaFil: ArgĂĽello, JosĂ© M.. Worcester Polytechnic Institute. Departmen Of Chemistry And Biochemistry; Estados Unido
A novel pulsatile platform for the ex-vivo evaluation of early remodelling events in human saphenous veins
Electrical conditioning of adipose-derived stem cells in a multi-chamber culture platform
In tissue engineering, several factors play key roles in providing adequate stimuli for cells differentiation, in particular biochemical and physical stimuli, which try to mimic the physiological microenvironments. Since electrical stimuli are important in the developing heart, we have developed an easy-to-use, cost-effective cell culture platform, able to provide controlled electrical stimulation aimed at investigating the influence of the electric field in the stem cell differentiation process. This bioreactor consists of an electrical stimulator and 12 independent, petri-like culture chambers and a 3-D computational model was used to characterize the distribution and the intensity of the electric field generated in the cell culture volume. We explored the effects of monophasic and biphasic square wave pulse stimulation on a mouse adipose-derived stem cell line (m17.ASC) comparing cell viability, proliferation, protein, and gene expression. Both monophasic (8V, 2ms, 1Hz) and biphasic (+4V, 1ms and -4V, 1ms; 1Hz) stimulation were compatible with cell survival and proliferation. Biphasic stimulation induced the expression of Connexin 43, which was found to localize also at the cell membrane, which is its recognized functional mediating intercellular electrical coupling. Electrically stimulated cells showed an induced transcriptional profile more closely related to that of neonatal cadiomyocytes, particularly for biphasic stimulation. The developed platform thus allowed to set-up precise conditions to drive adult stem cells toward a myocardial phenotype solely by physical stimuli, in the absence of exogenously added expensive bioactive molecules, and can thus represent a valuable tool for translational applications for heart tissue engineering and regeneration
A dynamic distention protocol for whole-organ bladder decellularization: histological and biomechanical characterization of the acellular matrix
A combined physical\u2013chemical protocol for whole full-thickness bladder decellularization is proposed, based on organ cyclic distention through repeated infusion/withdrawal of the decellularization agents through the urethra. The dynamic decellularization was intended to enhance cell removal efficiency, facilitating the delivery of detergents within the inner layers of the tissue and the removal of cell debris. The use of mild chemical detergents (hypotonic solution and non-ionic detergent) was employed to limit adverse effects upon matrix 3D ultrastructure. Inspection of the presence of residual DNA and RNA was carried out on decellularized matrices to verify effective cell removal. Histological investigation was focused on assessing the retention of adequate structural and functional components that regulate the biomechanical behaviour of the acellular tissue. Biomechanical properties were evaluated through uniaxial tensile loading tests of tissue strips and through ex vivo filling cystometry to evaluate the whole-organ mechanical response to a physiological-like loading state. According to our results, a dynamic decellularization protocol of 17 h duration with a 5 ml/min detergent infusion flow rate revealed higher DNA removal efficiency than standard static decellularization, resulting in residual DNA content\u2009<\u200950 ng/mg dry tissue weight. Furthermore, the collagen network and elastic fibres distribution were preserved in the acellular ECM, which exhibited suitable biomechanical properties in the perspective of its future use as an implant for bladder augmentation
Influência de sistemas de irrigação sobre a emissão de metano e de óxido nitroso em solo cultivado com arroz.
Consensus Statement on Animals’ Relationship with Pediatric Oncohematological Patients, on Behalf of Infectious Diseases and Nurse Working Groups of the Italian Association of Pediatric Hematology-Oncology
: Contact with animals in pediatric oncohematologic patients is associated with many benefits, but the risk of contracting zoonoses, even if low, must be considered by clinicians. In order to assess the awareness about this topic, we surveyed the Italian pediatric oncohematology centers, which resulted in heterogeneous responses. The Infectious Diseases Working Group and the Nurse Working Group of the Italian Association of Pediatric Hematology-Oncology, together with veterinarians from the National Federation of Italian Veterinarians, drew up a consensus document to unify the indications to be given to families with the aim of guaranteeing a safe interaction between patients and animals and improving the collaboration of clinicians with veterinarians and families
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