Bayesian unit root testing

Η στασιμότητα μίας χρονοσειράς εξετάζεται από τους ελέγχους μοναδιαίας ρίζας. Η ύπαρξη μοναδιαίας ρίζας υποδηλώνει ότι η χρονοσειρά δεν είναι στάσιμη και γίνεται τυχαίος περίπατος. Η παρούσα διπλωματική εργασία ασχολείται με τον έλεγχο μοναδιαίας ρίζας σε αυτοπαλίνδρομα μοντέλα χρησιμοποιώντας μπεϋζιανές μεθόδους.The current dissertation analyzes the Bayesian unit root tests in autoregressive processes as an alternate to the classical autoregressive unit root tests. The Bayesian approach to unit root testing was mainly motivated by the power and size distortions of the classical tests under the Dickey-Fuller distribution. Initially, basic principles and theory concerning time series and Bayesian analysis are introduced which are then followed by the structure of the classical autoregressive tests and the Dickey- Fuller distribution. The subsequent chapter is devoted to the methods applied in the Bayesian unit root testing. Simulation results and conclusions based on two Bayesian methods are finally reported

HCV Defective Genomes Promote Persistent Infection by Modulating the Viral Life Cycle

Defective interfering (DI) RNAs have been detected in several human viruses. HCV in-frame deletions mutants (IFDMs), missing mainly the envelope proteins, have been found in patient sera and liver tissues. IFDMs replicate independently and can be trans-packaged into infectious virions in the presence of full length viral genome. So far, their biological role is unclear. In this study, we have isolated and cloned IFDMs from sera samples and liver tissues of patients infected with HCV genotypes 1b, 2a, and 3a. IFDMs were present in up to 26% of samples tested. Using the in vitro HCV cell culture system, co-expression of the wild type (wt) HCV replicon with HCV IFDMs RNA resulted in increased HCV replication. Additionally, co-transfection of the HCV full length genome RNA and a defective mutant missing the envelope region led to increased viral release, collectively suggesting an important biological role for IFDMs in the virus life cycle. Recently, exosomes, masters of intercellular communication, have been implicated in the transport of HCV viral genomes. We report for the first time that exosomal RNA isolated from HCV sera samples contains HCV defective genomes. We also demonstrate that inhibition of exosomal biogenesis and release influences HCV viral replication. Overall, we provide evidence that the presence of HCV IFDMs affects both viral replication and release. IFDMs exploit exosomes as means of transport, a way to evade the immune system, to spread more efficiently and possibly maintain persistent infection

A Case Report of Pulmonary Exacerbation after Initiation of Lumacaftor/Ivacaftor Therapy in a CF Female with Complicated Lung Disease

Novel targeted treatments for Cystic Fibrosis give rise to new hope for an ever-growing number of CF patients with various mutations. However, very little evidence and guidelines exist to steer clinical decisions regarding patients whose illness takes an unexpected course. In such cases, the benefits and risks of discontinuing these treatments must be carefully and individually weighed, since their long-term effects remain mainly uncharted territory. In this report we document the case of a homozygous F508del CF patient with severe lung disease who presented with a pulmonary exacerbation shortly after the beginning of treatment with lumacaftor/ivacaftor and the complicated initial phase of therapy, which was followed by significant improvements

Middle mesial canal in mandibular molars:review and clinical case reports

Aim: The purpose of this study was to emphasise the importance of familiarisation with the internal anatomy of the mesial root of human permanent mandibular molars. Materials and methods: A literature review was conducted and four clinical cases of mandibular molars exhibiting an additional middle mesial canal are presented. Non-surgical treatment and retreatment procedures are described. Results: The middle mesial canals in all cases demonstrated a merging configuration with either the mesiobuccal or the mesiolingual canal. Acknowledgement of this configuration bears significant clinical implications. Enhanced magnification and illumination were indispensable for the detection and negotiation of the intermediate canal. Conclusions: The middle mesial canal constitutes an anatomic component that needs to be acknowledged during endodontic treatment of the mandibular molars. Awareness of its occurrence along with visual augmentation may aid a higher detection rate. Keywords: mandibular molars, middle mesial canal, root canal anatom

Insights into the Diversity and Population Structure of Predominant <i>Typhlocybinae</i> Species Existing in Vineyards in Greece

Insects of the subfamily Typhlocybinae (Hemiptera: Cicadellidae) are pests of economically important agricultural and horticultural crops. They damage the plants directly or indirectly by transmitting plant pathogens, resulting in significant yield loss. Several leafhoppers of this subfamily use vines as hosts. Accurate and rapid identification is the key to their successful management. The aim of this study is to determine the Typhlocybinae species that exist in vineyards all over Greece and investigate the relationship between them. For this purpose, yellow sticky traps were placed, morphological and molecular data were collected, and phylogenetic models were analyzed. The mitochondrial marker Cytochrome Oxidase Subunit I (mtCOI) was applied for the DNA and phylogenetic analysis. The combination of morphological and molecular data resulted in identifying the existence of six different species all over Greece: Arboridia adanae, Asymmetrasca decedens, Hebata decipiens, Hebata vitis, Jacobiasca lybica and Zygina rhamni. Forty-eight different haplotypes were found to exist in the different regions of the country

Primary aldosteronism in patients with adrenal incidentaloma: Is screening appropriate for everyone?

Primary aldosteronism (PA) is a common form of secondary hypertension. Several guidelines recommend that patients with adrenal incidentaloma have a high probability of suffering from PA. We conducted a prospective study of 269 consecutive adults with adrenal incidentaloma to investigate the prevalence and clinical characteristics of PA. In total, 9 participants were detected with PA, suggesting a prevalence of 3.35% among the study population. PA participants had a higher blood pressure level by 14/20.8 mm Hg and a lower serum potassium level by 0.8 mmol/L (P < .05). Importantly, all patients with PA presented with concurrent indications (hypertension with or without hypokalemia) for screening of the disease, but they have not undergone relative screening by the referring physician, thus casting doubts about the appropriate implementation of current guidelines in real‐life practice. Intense efforts are needed to familiarize physicians with recommendations for PA to minimize undiagnosed cases and the detrimental sequelae of this endocrine form of hypertension

Altered Expression of Intestinal Tight Junctions in Patients with Chronic Kidney Disease: A Pathogenetic Mechanism of Intestinal Hyperpermeability

Background: Systemic inflammation in chronic kidney disease (CKD) is associated (as a cause or effect) with intestinal barrier dysfunction and increased gut permeability, with mechanisms not yet fully understood. This study investigated different parameters of the intestinal barrier in CKD patients, especially tight junction (TJ) proteins and their possible association with systemic endotoxemia and inflammation. Methods: Thirty-three patients with stage I–IV CKD (n = 17) or end-stage kidney disease (ESKD) (n = 16) and 11 healthy controls underwent duodenal biopsy. Samples were examined histologically, the presence of CD3+ T-lymphocytes and the expression of occludin and claudin-1 in the intestinal epithelium was evaluated by means of immunohistochemistry, circulating endotoxin concentrations were determined by means of ELISA and the concentrations of the cytokines IL-1β, IL-6, IL-8, IL-10 and TNF-α in serum were measured using flow cytometry. Results: Patients with stage I–IV CKD or ESKD had significantly higher serum endotoxin, IL-6, IL-8 and IL-10 levels compared to controls. Intestinal occludin and claudin-1 were significantly decreased, and their expression was inversely correlated with systemic endotoxemia. Regarding occludin, a specific expression pattern was observed, with a gradually increasing loss of its expression from the crypt to the tip of the villi. Conclusion: The expression of occludin and claudin-1 in enterocytes is significantly reduced in patients with CKD, contributing to systemic endotoxemia and inflammatory responses in these patients