Zero sound in a single component fermion - Bose Einstein Condensate mixture

The resonant dynamics of mediated interactions supports zero-sound in a cold atom degenerate mixture of a single component fermion gas and a Bose-Einstein condensate (BEC). We characterize the onset of instability in the phase separation of an unstable mixture and we find a rich collective mode structure for stable mixtures with one undamped mode that exhibits an avoided crossing and a Landau-damped mode that terminates.Comment: 4 pages, 2 figure

Current-induced spin polarization in InGaAs and GaAs epilayers with varying doping densities

The current-induced spin polarization and momentum-dependent spin-orbit field were measured in In$_{x}$Ga$_{1-x}$As epilayers with varying indium concentrations and silicon doping densities. Samples with higher indium concentrations and carrier concentrations and lower mobilities were found to have larger electrical spin generation efficiencies. Furthermore, current-induced spin polarization was detected in GaAs epilayers despite the absence of measurable spin-orbit fields, indicating that the extrinsic contributions to the spin polarization mechanism must be considered. Theoretical calculations based on a model that includes extrinsic contributions to the spin dephasing and the spin Hall effect, in addition to the intrinsic Rashba and Dresselhaus spin-orbit coupling, are found to qualitatively agree with the experimental results.Comment: 16 pages, 8 figure

Common features between neoplastic and preneoplastic lesions of the biliary tract and the pancreas

The bile duct system and pancreas show many similarities due to their anatomical proximity and common embryological origin. Consequently, preneoplastic and neoplastic lesions of the bile duct and pancreas share analogies in terms of molecular, histological and pathophysiological features. Intraepithelial neoplasms are reported in biliary tract, as biliary intraepithelial neoplasm (BilIN), and in pancreas, as pancreatic intraepithelial neoplasm (PanIN). Both can evolve to invasive carcinomas, respectively cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary neoplasms arise in biliary tract and pancreas. Intraductal papillary neoplasm of the biliary tract (IPNB) share common histologic and phenotypic features such as pancreatobiliary, gastric, intestinal and oncocytic types, and biological behavior with the pancreatic counterpart, the intraductal papillary mucinous neoplasm of the pancreas (IPMN). All these neoplastic lesions exhibit similar immunohistochemical phenotypes, suggesting a common carcinogenic process. Indeed, CCA and PDAC display similar clinic-pathological features as growth pattern, poor response to conventional chemotherapy and radiotherapy and, as a consequence, an unfavorable prognosis. The objective of this review is to discuss similarities and differences between the neoplastic lesions of the pancreas and biliary tract with potential implications on a common origin from similar stem/progenitor cells

Measurements of vehicle pollutants in a high-traffic urban area by a multiwavelength dial approach: Correlation between two different motor vehicle pollutants

The development and improvement of monitoring techniques to measure the concentration of pollutants in the atmosphere are a starting point to guarantee high levels of human health and environmental safety. The combination of lidar and dial techniques, by measuring backscattering signals and reconstructing the map of their concentrations, can be used to provide detailed information about the presence of aerosols, particulate and pollutions. Moreover, by using a multiwavelength approach, it is possible to increase the measurement accuracy and reliability. In this work, the dial approach is used to monitor the pollution in a very congested urban area with high trac. In order to provide a validation of the results, correlation analyses between the measured pollutants was performed. A new lidar analysis method, based on the least-square minimization technique, was introduced and demonstrated to work properly. The dial capability to detect polluted areas was shown—and by correlation analysis—also the possibility to identify the source of pollutions can be performed

NUOVE TECNOLOGIE NELL¿AMBITO DELL¿ANTROPOLOGIA FISICA E FORENSE:IMAGING E MODELLAZIONE 3D

Aim of this study is the investigation of the potentialities and limits of the new 3D technologies to be used for documentation, archiving and imaging in the context of Physical and Forensic Anthropology. The widest possible variety of anthropological material was digitally acquired: from skeletal remains into an archaeological site, skeletal elements acquired in the laboratory, to living subjects. The most effective "techniques" for the acquisition of different types of materials were studied and the limits of the scan based on the intrinsic characteristics of the material acquired and the type of instrument used were checked. The Laser Scanner technology has proved to be the most suitable and fast for the acquisition of Skull and Mandible on which to conduct studies about biological profile and identification. The 3D models acquired using Laser Scanner have been used to test a technique of craniofacial Superimposition. The results show that the use of the 3D model of the skull facilitates the process of superimposition; the persistence of a high percentage of false positives indicates that this technique should not be used to identify, it could rather be utilized to exclude. The models of the skull and mandible acquired with 3D laser scanners have been tested as a base to conduct facial reconstructions in the virtual environment. The facial reconstructions performed by two inter-operators were compared using a colorimetric map that has detected good homogeneity in morphometric terms in specific regions of the face but also discrepancies partly due to the different locations of some landmarks made by the two operators, partly due to the shortage of landmarks. New CT technologies generation were also tested: the possibility of age determination from dental volumes was studied with the cone-beam CT technology. Through the use of free software it has been possible to obtain the necessary volumes to calculate the relationship between the volume of the pulp and the volume of its corresponding tooth and carry out the study of the regression. The coefficient of correlation and determination found are comparable to those conducted by other authors using the most expensive equipment; the equation obtained still shows, however, lack of precision of the estimation age. A study that shows that the use of CBCT technology can improve the investigation of morphological stab wounds on cancellous bones was conducted. Conversely metric analysis of the lesions seems not to be very reliable. The acquisition of stab wound with pQCT technology was conducted in a real case: a 3D model was created, in order to allow the operator to define the volume of the lack of tissues related to the lesion. The application of pQCT scan proved to be a potentially useful tool for assessment of bone trauma. As regards the antemortem injury, the CBCT technology was used in the evaluation of the internal structure of the callus. The results could lay the foundation for new perspectives on bone callus evaluation and aging with cone-beam CT technique. In conclusion this study has showed and tested the various applications of 3D technologies in Physical and Forensic Anthropology, defining their limits and in awareness of the importance of the irreplaceable critical judgment of the operator

A simplified procedure for the evaluation of the seismic performance of bridge piers on caisson foundations

In this paper, a simplified procedure for the evaluation of the seismic performance of bridge piers founded on caissons subjected to strong ground motions is outlined. To this end, the up-per-bound semi-empirical relationships proposed in [1] are considered for the estimation of the seismic performance, expressed in terms of the maximum and permanent values of the deck drift ratio attained during and at the end of the seismic event. These drifts were related to the period ratio Teq/T0 between the fundamental periods of the deck-pier-caisson-soil sys-tem and of the soil column in free-field conditions. The deck drift and the period ratios were extracted from the results of an extensive parametric study, where 14 different systems were subjected to 6 real high-intensity seismic records. In the parametric study, 3D dynamic anal-yses were performed with the Finite Element Method in the time domain, in terms of effective stresses but assuming undrained conditions and adopting an elastic-plastic constitutive model to reproduce the irreversible soil behaviour under cyclic loading. As 3D dynamic numerical analyses are not expected to become an every-day design tool, the period ratios Teq/T0 are evaluated through empirical and analytical relationships available in the literature as well and then compared with the ratios obtained from the parametric study, to assess the possibil-ity of using simplified relationships while still getting a reliable estimate of the deck drift ra-tio. It is shown that these relationships can be profitably adopted provided that a fair estimate of the equivalent shear wave velocity, depending on the intensity of the seismic inputs, is used

A new class of indicators for the model selection of scaling laws in nuclear fusion

The development of computationally efficient model selection strategies represents an important problem facing the analysis of Nuclear Fusion experimental data, in particular in the field of scaling laws for the extrapolation to future machines, and image processing. In this paper, a new model selection indicator, named Model Falsification Criterion (MFC), will be presented and applied to the problem of choosing the most generalizable scaling laws for the power threshold to access the H-mode of confinement in Tokamaks. The proposed indicator is based on the properties of the model residuals, their entropy and an implementation of the data falsification principle. The model selection ability of the proposed criterion will be demonstrated in comparison with the most widely used frequentist (Akaike Information Criterion) and bayesian (Bayesian Information Criterion) indicators.Comment: 4 pages, 2 figure

The FXR agonist obeticholic acid inhibits the cancerogenic potential of human cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive cancer with high resistance to chemotherapeutics. CCA is enriched in cancer stem cells, which correlate with aggressiveness and prognosis. FXR, a member of the metabolic nuclear receptor family, is markedly down-regulated in human CCA. Our aim was to evaluate, in primary cultures of human intrahepatic CCA (iCCA), the effects of the FXR agonist obeticholic acid (OCA), a semisynthetic bile acid derivative, on their cancerogenic potential. Primary human iCCA cell cultures were prepared from surgical specimens of mucinous or mixed iCCA subtypes. Increasing concentrations (0–2.5 μM) of OCA were added to culture media and, after 3–10 days, effects on proliferation (MTS assay, cell population doubling time), apoptosis (annexin V-FITC/propidium iodide), cell migration and invasion (wound healing response and Matrigel invasion assay), and cancerogenic potential (spheroid formation, clonogenic assay, colony formation capacity) were evaluated. Results: FXR gene expression was downregulated (RT-qPCR) in iCCA cells vs normal human biliary tree stem cells (p < 0.05) and in mucinous iCCA vs mixed iCCA cells (p < 0.05) but was upregulated by addition of OCA. OCA significantly (p < 0.05) inhibited proliferation of both mucinous and mixed iCCA cells, starting at a concentration as low as 0.05 μM. Also, CDCA (but not UDCA) inhibited cell proliferation, although to a much lower extent than OCA, consistent with its different affinity for FXR. OCA significantly induced apoptosis of both iCCA subtypes and decreased their in vitro cancerogenic potential, as evaluated by impairment of colony and spheroid formation capacity and delayed wound healing and Matrigel invasion. In general, these effects were more evident in mixed than mucinous iCCA cells. When tested together with Gemcitabine and Cisplatin, OCA potentiated the anti-proliferative and pro-apoptotic effects of these chemotherapeutics, but mainly in mixed iCCA cells. OCA abolished the capacity of both mucinous and mixed iCCA cells to form colonies when administered together with Gemcitabine and Cisplatin. In subcutaneous xenografts of mixed iCCA cells, OCA alone or combined with Gemcitabine or Cisplatin markedly reduced the tumor size after 5 weeks of treatment by inducing necrosis of tumor mass and inhibiting cell proliferation. In conclusion, FXR is down-regulated in iCCA cells, and its activation by OCA results in anti-cancerogenic effects against mucinous and mixed iCCA cells, both in vitro and in vivo. The effects of OCA predominated in mixed iCCA cells, consistent with the lower aggressiveness and the higher FXR expression in this CCA subtype. These results, showing the FXR-mediated capacity of OCA to inhibit cholangiocarcinogenesis, represent the basis for testing OCA in clinical trials of CCA patients

D-dimer for risk stratification and antithrombotic treatment management in acute coronary syndrome patients: asystematic review and metanalysis

Background: Data on the prognostic role of D-dimer in patients with acute coronary syndrome (ACS) are controversial. Our aim was to summarize current evidence on the association between D-dimer levels and short/long-term poor prognosis of ACS patients. We also investigated the association between D-dimer and no-reflow phenomenon.Methods: Systematic review and metanalysis of observational studies including ACS patients and reporting data on D-dimer levels. PubMed and SCOPUS databases were searched. Data were combined with hazard ratio (HR) and metanalysed. The principal endpoint was a composite of cardiovascular events (CVEs) including myocardial infarction, all-cause and cardiovascular mortality.Results: Overall, 32 studies included in the systematic review with 28,869 patients. Of them, 6 studies investigated in-hospital and 26 studies long-term outcomes. Overall, 23 studies showed positive association of high D-dimer levels with CVEs. D-dimer levels predicted poor prognosis in all studies reporting in-hospital outcomes. Five studies satisfied inclusion criteria and were included in the metanalysis, with a total of 8616 patients. Median follow-up was 13.2 months with 626 CVEs. The pooled HR for D-dimer levels and CVEs was 1.264 (95% CI 1.134-1.409). Five out of 7 studies (4195 STEMI patients) investigating the association between D-dimer levels and no-reflow showed a positive correlation of D-dimer levels with no-reflow.Conclusions: In patients with ACS, D-dimer was associated with higher in-hospital and short/long-term complications. D-dimer was also higher in patients with no-reflow phenomenon. The use of D-dimer may help to identify patients with residual thrombotic risk after ACS