Bayesian Model Selection for Beta Autoregressive Processes

We deal with Bayesian inference for Beta autoregressive processes. We restrict our attention to the class of conditionally linear processes. These processes are particularly suitable for forecasting purposes, but are difficult to estimate due to the constraints on the parameter space. We provide a full Bayesian approach to the estimation and include the parameter restrictions in the inference problem by a suitable specification of the prior distributions. Moreover in a Bayesian framework parameter estimation and model choice can be solved simultaneously. In particular we suggest a Markov-Chain Monte Carlo (MCMC) procedure based on a Metropolis-Hastings within Gibbs algorithm and solve the model selection problem following a reversible jump MCMC approach

A copula-based approach for the estimation of wave height records through spatial correlation

publisher: Elsevier articletitle: A copula-based approach for the estimation of wave height records through spatial correlation journaltitle: Coastal Engineering articlelink: http://dx.doi.org/10.1016/j.coastaleng.2016.06.008 content_type: article copyright: © 2016 The Authors. Published by Elsevier B.V

Intratumor Regulatory Noncytotoxic NK Cells in Patients with Hepatocellular Carcinoma

Previous studies support the role of natural killer (NK) cells in controlling hepatocellular carcinoma (HCC) progression. However, ambiguity remains about the multiplicity and the role of different NK cell subsets, as a pro-oncogenic function has been suggested. We performed phenotypic and functional characterization of NK cells infiltrating HCC, with the corresponding nontumorous tissue and liver from patients undergoing liver resection for colorectal liver metastasis used as controls. We identified a reduced number of NK cells in tumors with higher frequency of CD56(BRIGHT)CD16(-) NK cells associated with higher expression of NKG2A, NKp44, and NKp30 and downregulation of NKG2D. Liver-resident (CXCR6(+)) NK cells were reduced in the tumors where T-bet(hi)Eomes(lo) expression was predominant. HCCs showed higher expression of CD49a with particular enrichment in CD49a(+)Eomes(+) NK cells, a subset typically represented in the decidua and playing a proangiogenic function. Functional analysis showed reduced TNF-alpha production along with impaired cytotoxic capacity that was inversely related to CXCR6(-), T-bet(hi)Eomes(lo), and CD49a(+)Eomes(+) NK cells. In conclusion, we identified a subset of NK cells infiltrating HCC, including non-liver-resident cells that coexpressed CD49a and Eomes and showed reduced cytotoxic potential. This NK cell subset likely plays a regulatory role in proangiogenic function

Sub-surface modifications in silicon with ultra-short pulsed lasers above 2 µm

Nonlinear optical phenomena in silicon such as self-focusing and multi-photon absorption are strongly dependent on the wavelength, energy, and duration of the exciting pulse, especially for wavelengths >2µm. We investigate the sub-surface modification of silicon using ultra-short pulsed lasers at wavelengths in the range of 1950–2400 nm, at a pulse duration between 2 and 10 ps and pulse energy varying from 1 µJ to 1 mJ. We perform numerical simulations and experiments using fiber-based lasers built in-house that operate in this wavelength range for the surface and sub-surface processing of Si-wafers. The results are compared to the literature data at 1550 nm. Due to a dip in the nonlinear absorption spectrum and a peak in the spectrum of the third-order nonlinearity, the wavelengths between 2000 and 2200 nm prove to be more favorable for creating sub-surface modifications in silicon. This is the case even though those wavelengths do not allow as tight focusing as those at 1550 nm. This is compensated for by an increased self-focusing due to the nonlinear Kerr-effect around 2100 nm at high light intensities, characteristic for ultra-short pulses

The late Pleistocene Po River lowstand wedge in the Adriatic Sea : Controls on architecture variability and sediment partitioning

The authors dedicate this study to their colleague Giovanni Bortoluzzi, who passed away in 2015. A special tanks is due to Marco Ligi and Nevio Zitellini for geophysical data acquisition and processing; Marco Pastore and Filippo D'Oriano for their support during the cruise LSD2014 and processing of geophysical data. Elisabetta Campiani provided additional support for processing the multibeam bathymetry. A particular thank goes to Cpt. Emanuele Gentile and the crew of the R/V Urania during cruise LSD 2014. We thank Ronald Steel and an anonymous Reviewer for their constructive comments. This project was funded by ExxonMobil Upstream Research Company and by the Flagship Project RITMARE–The Italian Research for the Sea. We acknowledge the European Union Project PROMESS-1 (contract EVR1-2001-41) for borehole PRAD 1-2. This is ISMAR-CNR contribution number 1959.Peer reviewedPostprin

A Bayesian Survival Analysis of a Historical Dataset: How Long Do Popes Live?

University courses in statistical modeling often place great emphasis on methodological theory, illustrating it only briefly by means of limited and repeatedly used standard examples. Unfortunately, this approach often fails to actively engage and motivate students in their learning process. The teaching of statistical topics such as Bayesian survival analysis can be enhanced by focusing on innovative applications. Here we discuss the visualization and modelling of a data set of historical events comprising the post–election survival times of popes. Inference, prediction and model checking are performed in the Bayesian framework, with comparisons being made with the frequentist approach. Further opportunities for similar statistical investigations are outlined

A novel DSP zebrafish model reveals training- and drug-induced modulation of arrhythmogenic cardiomyopathy phenotypes

Arrhythmogenic cardiomyopathy (AC) is an inherited disorder characterized by progressive loss of the ventricular myocardium causing life-threatening ventricular arrhythmias, syncope and sudden cardiac death in young and athletes. About 40% of AC cases carry one or more mutations in genes encoding for desmosomal proteins, including Desmoplakin (Dsp). We present here the first stable Dsp knock-out (KO) zebrafish line able to model cardiac alterations and cell signalling dysregulation, characteristic of the AC disease, on which environmental factors and candidate drugs can be tested. Our stable Dsp knock-out (KO) zebrafish line was characterized by cardiac alterations, oedema and bradycardia at larval stages. Histological analysis of mutated adult hearts showed reduced contractile structures and abnormal shape of the ventricle, with thinning of the myocardial layer, vessels dilation and presence of adipocytes within the myocardium. Moreover, TEM analysis revealed “pale”, disorganized and delocalized desmosomes. Intensive physical training protocol caused a global worsening of the cardiac phenotype, accelerating the progression of the disease. Of note, we detected a decrease of Wnt/β-catenin signalling, recently associated with AC pathogenesis, as well as Hippo/YAP-TAZ and TGF-β pathway dysregulation. Pharmacological treatment of mutated larvae with SB216763, a Wnt/β-catenin agonist, rescued pathway expression and cardiac abnormalities, stabilizing the heart rhythm. Overall, our Dsp KO zebrafish line recapitulates many AC features observed in human patients, pointing at zebrafish as a suitable system for in vivo analysis of environmental modulators, such as the physical exercise, and the screening of pathway-targeted drugs, especially related to the Wnt/β-catenin signalling cascade

Efficient clofilium tosylate-mediated rescue of POLG-related disease phenotypes in zebrafish

The DNA polymerase gamma (Polg) is a nuclear-encoded enzyme involved in DNA replication in animal mitochondria. In humans, mutations in the POLG gene underlie a set of mitochondrial diseases characterized by mitochondrial DNA (mtDNA) depletion or deletion and multiorgan defects, named POLG disorders, for which an effective therapy is still needed. By applying antisense strategies, ENU- and CRISPR/Cas9-based mutagenesis, we have generated embryonic, larval-lethal and adult-viable zebrafish Polg models. Morphological and functional characterizations detected a set of phenotypes remarkably associated to POLG disorders, including cardiac, skeletal muscle, hepatic and gonadal defects, as well as mitochondrial dysfunctions and, notably, a perturbed mitochondria-to-nucleus retrograde signaling (CREB and Hypoxia pathways). Next, taking advantage of preliminary evidence on the candidate molecule Clofilium tosylate (CLO), we tested CLO toxicity and then its efficacy in our zebrafish lines. Interestingly, at well tolerated doses, the CLO drug could successfully rescue mtDNA and Complex I respiratory activity to normal levels, even in mutant phenotypes worsened by treatment with Ethidium Bromide. In addition, the CLO drug could efficiently restore cardio-skeletal parameters and mitochondrial mass back to normal values. Altogether, these evidences point to zebrafish as a valuable vertebrate organism to faithfully phenocopy multiple defects detected in POLG patients. Moreover, this model represents an excellent platform to screen, at the whole-animal level, candidate molecules with therapeutic effects in POLG disorders