Sintesi monografica delle risorse idriche sotterranee della Sardegna

L'attenta analisi di tutti i parametri che concorrono alla stesura di un bilancio idrico, ha come facile conseguenza l'individuazione in quella regione della possibile presenza di acqua nel sottosuolo la cui consistenza può essere definita attraverso ulteriori parametri, soprattutto di tipo geofisico, che ci consentono la valutazione geometrica dei suoi acquiferi. Nel 1979 l'Istituto di Mineralogia e Geologia ha svolto un'indagine per conto della Cassa per il Mezzogiorno allo scopo di .individuare. aree di interesse idrogeologico e pertanto possibili risorse idriche da poter utilizzare in tempi brevi. . Il lavoro che interessa tutta la Sardegna è stato condotto attraverso quattro fasi distinte: A - Analisi del territorio e sua ripartizione in bacini idrografici e idrogeologici; B - Esame degli afflussi; C - Esame dei deflussi; D - Ipotesi di bilancio delle acque sotterranee per unità idrografica

Local Charge Excesses in Metallic Alloys: a Local Field Coherent Potential Approximation Theory

Electronic structure calculations performed on very large supercells have shown that the local charge excesses in metallic alloys are related through simple linear relations to the local electrostatic field resulting from distribution of charges in the whole crystal. By including local external fields in the single site Coherent Potential Approximation theory, we develop a novel theoretical scheme in which the local charge excesses for random alloys can be obtained as the responses to local external fields. Our model maintains all the computational advantages of a single site theory but allows for full charge relaxation at the impurity sites. Through applications to CuPd and CuZn alloys, we find that, as a general rule, non linear charge rearrangements occur at the impurity site as a consequence of the complex phenomena related with the electronic screening of the external potential. This nothwithstanding, we observe that linear relations hold between charge excesses and external potentials, in quantitative agreement with the mentioned supercell calculations, and well beyond the limits of linearity for any other site property.Comment: 11 pages, 1 table, 7 figure

Crystal growth as an excitable medium

Crystal growth has been widely studied for many years, and, since the pioneering work of Burton, Cabrera and Frank, spirals and target patterns on the crystal surface have been understood as forms of tangential crystal growth mediated by defects and by two-dimensional nucleation. Similar spirals and target patterns are ubiquitous in physical systems describable as excitable media. Here, we demonstrate that this is not merely a superficial resemblance, that the physics of crystal growth can be set within the framework of an excitable medium, and that appreciating this correspondence may prove useful to both fields. Apart from solid crystals, we discuss how our model applies to the biomaterial nacre, formed by layer growth of a biological liquid crystal

Some interesting features of new massive gravity

A proof that new massive gravity - the massive 3D gravity model proposed by Bergshoeff, Hohm and Townsend (BHT) - is the only unitary system at the tree level that can be constructed by augmenting planar gravity through the curvature-squared terms, is presented. Two interesting gravitational properties of the BHT model, namely, time dilation and time delay, which have no counterpart in the usual Einstein 3D gravity, are analyzed as well.Comment: Submitted to Classical and Quantum Gravit

Sagittal Abdominal Diameter As A Surrogate Marker Of Insulin Resistance In An Admixtured Population-brazilian Metabolic Syndrome Study (brams)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background Sagittal abdominal diameter (SAD) has been proposed as a surrogate marker of insulin resistance (IR). However, the utilization of SAD requires specific validation for each ethnicity. We aimed to investigate the potential use of SAD, compared with classical anthropometrical parameters, as a surrogate marker of IR and to establish the cutoff values of SAD for screening for IR. Methods A multicenter population survey on metabolic disorders was conducted. A race-admixtured sample of 824 adult women was assessed. The anthropometric parameters included: BMI, waist circumference (WC), waist-to-hip ratio and SAD. IR was determined by a hyperglycemic clamp and the HOMA-IR index. Results After adjustments for age and total body fat mass, SAD (r = 0.23 and r = -0.70) and BMI (r = 0.20 and r = -0.71) were strongly correlated with the IR measured by the HOMA-IR index and the clamp, respectively (p < 0.001). In the ROC analysis, the optimal cutoff for SAD in women was 21.0 cm. The women with an increased SAD presented 3.2 (CI 95%: 2.1-5.0) more likelihood of having IR, assessed by the HOMA-IR index compared with those with normal SAD (p < 0.001); whereas women with elevated BMI and WC were 2.1 (95% CI: 1.4-3.3) and 2.8 (95% CI: 1.7-4.5) more likely to have IR (p < 0.001), respectively. No statistically significant results were found for waist-to-hip ratio. Conclusions SAD can be a suitable surrogate marker of IR. Understanding and applying routine and simplified methods is essential because IR is associated with an increased risk of obesity-related diseases even in the presence of normal weight, slight overweight, as well as in obesity. Further prospective analysis will need to verify SAD as a determinant of clinical outcomes, such as type 2 diabetes and cardiovascular events, in the Brazilian population.105Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [563664/2010-0

Desarrollo de simulaciones numéricas para estudiar la dinámica de un concepto de aeronave X-HALE-UAV

En este trabajo se presenta una herramienta de simulación numérica que permite estudiar el comportamiento dinámico de un concepto simplificado de vehículo aéreo no tripulado (UAV) extremadamente flexible (X) que opera a gran altitud y con gran autonomía (HALE). La aeronave es modelada como una colección de cuerpos rígidos conectados entre sí por articulaciones flexibles. Las ecuaciones que gobiernan la dinámica del sistema se obtienen por medio de una formulación híbrida basada en las ecuaciones de Newton-Euler, para los grados de libertad primarios, y las ecuaciones de Lagrange, para los grados de libertad internos (i.e., aquellos que describen el movimiento relativo entre el fuselaje y las alas). La integración numérica de las ecuaciones de movimiento se realiza simultánea e interactivamente en el dominio del tiempo mediante el método modificado de Hamming, un esquema predictor-corrector de cuarto orden. Las simulaciones numéricas presentadas en este trabajo muestran que el modelo desarrollado permite captar grandes deflexiones de los tramos de ala; posibilitando un estudio integral del acoplamiento dinámico entre los "modos" de cuerpo rígido (o primarios) y los "modos" elásticos (o secundarios) de un concepto X-HALE-UAV. Este trabajo es parte de un proyecto de investigación de mayor envergadura que apunta a mejorar la comprensión de los fenómenos aeroelásticos no-lineales asociados a los vehículos aéreos de gran escala.Fil: Argüello, Marcos E.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Estructuras; ArgentinaFil: Preidikman, Sergio. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Departamento de Estructuras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; ArgentinaFil: Roccia, Bruno Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; Argentin

Tumor and circulating biomarkers in patients with second-line hepatocellular carcinoma from the randomized phase II study with tivantinib

ARQ 197-215 was a randomized placebo-controlled phase II study testing the MET inhibitor tivantinib in second-line hepatocellular carcinoma (HCC) patients. It identified tumor MET as a key biomarker in HCC. Aim of this research was to study the prognostic and predictive value of tumor (MET, the receptor tyrosine kinase encoded by the homonymous MNNG-HOS transforming gene) and circulating (MET, hepatocyte growth factor [HGF], alpha-fetoprotein [AFP], vascular endothelial growth factor [VEGF]) biomarkers in second-line HCC. Tumor MET-High status was centrally assessed by immunohistochemistry. Circulating biomarkers were centrally analyzed on serum samples collected at baseline and every 4-8 weeks, using medians as cut-off to determine High/Low status. Tumor MET, tested in 77 patients, was more frequently High after (82%) versus before (40%) sorafenib. A significant interaction (p = 0.04) between tivantinib and baseline tumor MET in terms of survival was observed. Baseline circulating MET and HGF (102 patients) High status correlated with shorter survival (HR 0.61, p = 0.03, and HR 0.60, p = 0.02, respectively), while the association between AFP (104 patients) or VEGF (103 patients) status and survival was non-significant. Conclusions: Tumor MET levels were higher in patients treated with sorafenib. Circulating biomarkers such as MET and HGF may be prognostic in second-line HCC. These results need to be confirmed in larger randomized clinical trials

Treatment of a rapidly expanding thoracoabdominal aortic aneurysm after endovascular repair of descending thoracic aortic aneurysm in an old patient.

Background: Aortic pathology progression and/or procedure related complications following endovascular repair should always be considered mostly in older patients. We herein describe a hybrid procedure for treatment of rapidly expanding thoracoabdominal aneurysm following endovascular treatment of a descending thoracic aortic aneurysm in an older patient. Case presentation: A 82-year-old man at 18 months after endovascular surgery for a contained rupture of descending thoracic aortic aneurysm revealed a type IV thoracoabdominal aneurysm with significant increase of the aortic diameters at superior mesenteric and renal artery levels. A hybrid approach consisting of preventive visceral vessel revascularization and endovascular repair of entire abdominal aorta was performed. Under general anaesthesia and by xyphopubic laparotomy, the infrarenal aneurysmatic aorta and common iliac arteries were replaced by a bifurcated woven prosthetic graf. From each of the prosthetic branches two reverse 14x7 mm bifurcated PTFE prosthetic grafts were anastomized to both renal arteries and to the celiac axis and superior mesenteric artery, respectively. Vessel ischemia was restricted to the time required for anastomosis. Three 10 cm Gore endovascular stent-grafts for a total length of 15 cm, were used. The overlapping of the stent-grafts was carried out from the bottom upwards, starting from the aorto-iliac prosthetic body up to the healthy segment of thoracic aorta, 40 mm from the previous stent-grafts. The patient was discharged on the 9th postoperative day. Conclusion: This technique offers the advantage of a less invasive treatment, reducing the risk of paraplegia, visceral ischaemia and pulmonary complications, mostly in older patients