Are Output Growth-Rate Distributions Fat-Tailed? Some Evidence from OECD Countries

This work explores some distributional properties of aggregate output growth-rate time series. We show that, in the majority of OECD countries, output growth-rate distributions are well approximated by symmetric exponential power densities with tails much fatter than those of a Gaussian (but with finite moments of any order). Fat tails robustly emerge in output growth rates independently of: (i) the way we measure aggregate output; (ii) the family of densities employed in the estimation; (iii) the length of time lags used to compute growth rates. We also show that fat tails still characterize output growth-rate distributions even after one washes away outliers, autocorrelation and heteroscedasticity

Electrochemical biosensors for tracing cyanotoxins in food and environmental matrices

The adoption of electrochemical principles to realize on-field analytical tools for detecting pollutants represents a great possibility for food safety and environmental applications. With respect to the existing transduction mechanisms, i.e., colorimetric, fluorescence, piezoelectric etc., electrochemical mechanisms offer the tremendous advantage of being easily miniaturized, connected with low cost (commercially available) readers and unaffected by the color/turbidity of real matrices. In particular, their versatility represents a powerful approach for detecting traces of emerging pollutants such as cyanotoxins. The combination of electrochemical platforms with nanomaterials, synthetic receptors and microfabrication makes electroanalysis a strong starting point towards decentralized monitoring of toxins in diverse matrices. This review gives an overview of the electrochemical biosensors that have been developed to detect four common cyanotoxins, namely microcystin-LR, anatoxin-a, saxitoxin and cylindrospermopsin. The manuscript provides the readers a quick guide to understand the main electrochemical platforms that have been realized so far, and the presence of a comprehensive table provides a perspective at a glance

Direct, precise, enzyme-free detection of miR-103–3p in real samples by microgels with highly specific molecular beacons

Low abundance, small size, and sequence similarities render microRNA (miRNAs) detection challenging, particularly in real samples, where quantifying weakly expressed miRNAs can be arduous due to interference of more abundant molecules. The standard quantitative reverse transcription polymerase chain reaction (qRT-PCR) requires multiple steps, thermal cycles, and costly enzymatic reactions that can negatively affect results. Here we present a direct, precise, enzyme-free assay based on microgels particles conjugating molecular beacons (MB) capable of optically detecting low abundant miRNAs in real samples. We validate the applicability of microgels assay using qRT-PCR as a reference technology. As a relevant case, we chose miR-103-3p, a valuable diagnostic biomarker for breast cancer, both in serum samples and MCF7 cells. As a result, microgels assay quantifies miRNA molecules at room temperature in a single step, 1 h (vs. 4 hrs for qRT-PCR) without complementary DNA synthesis, amplification, or expensive reagents. Microgels assay exhibits femtomolar sensitivity, single nucleotide specificity, and a wide linear range (10(2)-10(7) fM) (wider than qRT-PCR), with low sample consumption (2 mu L) and excellent linearity (R-2= 0.98). To test the selectivity of the microgel assay in real samples, MCF7 cells were considered where the pool of 8 other miRNAs were further upregulated with respect to miRNA 103-3p. In such complex environments, microgels assay selectively detects the miRNA target, mainly due to MB advanced stability and specificity as well as high microgel antifouling properties. These results show the reliability of microgels assay to detect miRNAs in real samples

End-of-life in the operational functioning of public healthcare: ethical and legal issues

Background and aim: The article aims to outline the current scenario relative to the medical role in end-of-life issues. In order to do this, historical-legal references have been drawn upon relating to technical, legal and scientific thought and doctrine, as it has come down to us in the medical field through the evolution of ethical and philosophical frameworks. Methods: The authors have conducted a thorough analysis of end-of-life legislative initiatives, in Italy and across the EU, and court rulings to outline possible ways to harmonize and reconcile the current medical ethics frameworks with the needs and rights of all, especially the most vulnerable among us. To that end, the necessary operational choices and adjustments have not yet been made by our legal system, from a technical, as well as moral, standpoint. Results: An operational proposal has therefore been laid out to protect both healthcare providers and patients, in a relationship that goes beyond treatment in the strict sense, which prioritizes mutual needs as an integral part of a common, essential path. Conclusions: In order for doctors to consider themselves complete, they should in fact deal not only with life, but also with death

Andreev reflection in Au/La_{2-x}Sr_{x}CuO_{4} point-contact junctions: separation between pseudogap and phase-coherence gap

We made point-contact measurements with Au tips on La_{2-x}Sr_{x}CuO_{4} samples with 0.08 < x < 0.20 to investigate the relationship between superconducting gap and pseudogap. We obtained junctions whose conductance curves presented typical Andreev reflection features at all temperatures from 4.2 K up to T_c^A close to the bulk T_c. Their fit with the BTK-Tanaka-Kashiwaya model gives good results if a (s+d)-wave gap symmetry is used. The doping dependence of the low temperature dominant isotropic gap component Delta_{s} follows very well the T_{c} vs. x curve. These results support the separation between the superconducting (Andreev) gap and the pseudogap measured by angle-resolved photoemission spectroscopy (ARPES) and tunneling.Comment: 4 pages, 5 eps figures, 1 table. SNS 2001 Conferenc

Variation of the chemical and biological properties of a Technosol during seven years after a single application of compost

Technosols are composed of natural soils mixed with artificial materials and can be an inhospitable environment for the soil microbial community. The main goal of the current research was to evaluate temporal variations of Technosol quality through an integrated approach, considering all of the evaluated chemical, physical and biological characteristics for a period of seven years after a single application of compost. The soil samples were evaluated using the following parameters: pH; water content; water holding capacity; bulk density; porosity; organic matter and N contents; C/N ratio; fungal biomass; microbial biomass; respiration; metabolic quotient (qCO 2 ); and endogenous mineralisation coefficient (CEM). The overall evaluation showed that a single application of compost improved the soil quality in the short term. A decrease in Technosol quality over the long term appears to be due to deterioration of the physical and chemical properties, rather than a change in biological properties

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