2,532 research outputs found

    Cross-temporal Probabilistic Forecast Reconciliation

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    Forecast reconciliation is a post-forecasting process that involves transforming a set of incoherent forecasts into coherent forecasts which satisfy a given set of linear constraints for a multivariate time series. In this paper we extend the current state-of-the-art cross-sectional probabilistic forecast reconciliation approach to encompass a cross-temporal framework, where temporal constraints are also applied. Our proposed methodology employs both parametric Gaussian and non-parametric bootstrap approaches to draw samples from an incoherent cross-temporal distribution. To improve the estimation of the forecast error covariance matrix, we propose using multi-step residuals, especially in the time dimension where the usual one-step residuals fail. To address high-dimensionality issues, we present four alternatives for the covariance matrix, where we exploit the two-fold nature (cross-sectional and temporal) of the cross-temporal structure, and introduce the idea of overlapping residuals. We assess the effectiveness of the proposed cross-temporal reconciliation approaches through a simulation study that investigates their theoretical and empirical properties and two empirical forecasting experiments, using the Australian GDP and the Australian Tourism Demand datasets. For both applications, the optimal cross-temporal reconciliation approaches significantly outperform the incoherent base forecasts in terms of the Continuous Ranked Probability Score and the Energy Score. Overall, our study expands and unifies the notation for cross-sectional, temporal and cross-temporal reconciliation, thus extending and deepening the probabilistic cross-temporal framework. The results highlight the potential of the proposed cross-temporal forecast reconciliation methods in improving the accuracy of probabilistic forecasting models

    Stochastic Turing patterns in the Brusselator model

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    A stochastic version of the Brusselator model is proposed and studied via the system size expansion. The mean-field equations are derived and shown to yield to organized Turing patterns within a specific parameters region. When determining the Turing condition for instability, we pay particular attention to the role of cross diffusive terms, often neglected in the heuristic derivation of reaction diffusion schemes. Stochastic fluctuations are shown to give rise to spatially ordered solutions, sharing the same quantitative characteristic of the mean-field based Turing scenario, in term of excited wavelengths. Interestingly, the region of parameter yielding to the stochastic self-organization is wider than that determined via the conventional Turing approach, suggesting that the condition for spatial order to appear can be less stringent than customarily believed.Comment: modified version submitted to Phys Rev. E. 5. 3 Figures (5 panels) adde

    Rapamycin inhibits mTOR/p70S6K activation in CA3 region of the hippocampus of the rat and impairs long term memory

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    The present study was aimed at establishing whether the mTOR pathway and its downstream effector p70S6K in CA3 pyramidal neurons are under the modulation of the cholinergic input to trigger the formation of long term memories, similar to what we demonstrated in CA1 hippocampus. We performed in vivo behavioral experiments using the step down inhibitory avoidance test in adult Wistar rats to evaluate memory formation under different conditions. We examined the effects of rapamycin, an inhibitor of mTORC1 formation, scopolamine, a muscarinic receptor antagonist or mecamylamine, a nicotinic receptor antagonist, on short and long term memory formation and on the functionality of the mTOR pathway. Acquisition was conducted 30 min after i.c.v. injection of rapamycin. Recall testing was performed 1h, 4h or 24h after acquisition. We found that (1) mTOR and p70S6K activation in CA3 pyramidal neurons were involved in long term memory formation; (2) rapamycin significantly inhibited mTOR and of p70S6K activation at 4h, and long term memory impairment 24h after acquisition; (3) scopolamine impaired short but not long term memory, with an early increase of mTOR/p70S6K activation at 1h followed by stabilization at longer times; (4) mecamylamine and scopolamine co-administration impaired short term memory at 1h and 4h and reduced the scopolamine-induced increase of mTOR/p70S6K activation at 1h and 4h; (5) mecamylamine and scopolamine treatment did not impair long term memory formation; (6) unexpectedly, rapamycin increased mTORC2 activation in microglial cells. Our results demonstrate that in CA3 pyramidal neurons the mTOR/p70S6K pathway is under the modulation of the cholinergic system and is involved in long-term memory encoding, and are consistent with the hypothesis that the CA3 region of the hippocampus is involved in memory mechanisms based on rapid, one-trial object–place learning and recall. Furthermore, our results are in accordance with previous reports that selective molecular mechanisms underlie either short term memory, long term memory, or both. Furthermore, our discovery that administration of rapamycin increased the activation of mTORC2 in microglial cells supports a reappraisal of the beneficial/adverse effects of rapamycin administration

    Topoisomerase II alpha and TLE3 as predictive markers of response to anthracycline and taxane-containing regimens for neoadjuvant chemotherapy in breast cancer.

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    PURPOSE: Anthracyclines and taxanes are considered the standard for neoadjuvant chemotherapy of breast cancer, although they are often associated with serious side effects and wide variability of individual response. In this study, we analyzed the value of topoisomerase II alpha (TOP2A) and transducin-like enhancer of split 3 (TLE3) as predictive markers of response to therapy with anthracyclines and taxanes. MATERIALS AND METHODS: TOP2A and TLE3 protein expressions were evaluated using immunohistochemistry on 28 samples, obtained by core needle biopsy in patients with locally advanced breast carcinoma, subsequently subjected to epirubicin- and paclitaxel-based neoadjuvant chemotherapy. The immunohistochemical staining was correlated with the clinical response measured by the tumor size reduction evaluated by breast magnetic resonance imaging, prior and after chemotherapy, and by pathologic evaluation of the surgical specimen. RESULTS: Neoadjuvant chemotherapy achieved a size reduction in 26/28 tumors (92.9%), with an average percentage decrease of 45.6%. A downstaging was achieved in 71.4% of the cases of locally advanced carcinoma. TOP2A positivity was correlated with a greater reduction in tumor diameter (P=0.06); negative staining for TLE3 was predictive of a better response to neoadjuvant chemotherapy (P=0.07). A higher reduction in tumor diameter (P=0.03) was also found for tumors that were concurrently TLE3-negative and TOP2A-positive. CONCLUSION: TOP2A and TLE3 showed a correlation with response to neoadjuvant chemotherapy. While TOP2A is a well-known marker of response to anthracyclines-based chemotherapy, TLE3 is a new putative predictor of response to taxanes. Data from the current study suggest that TOP2A and TLE3 warrant further investigation in a larger series as predictors of response to neoadjuvant chemotherapy for locally advanced breast carcinoma

    Anger and depressive ruminations as predictors of dysregulated behaviours in borderline personality disorder.

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    BACKGROUND: Anger and depressive ruminations have recently received empirical attention as processes related to borderline personality disorder (BPD). The Emotional Cascade Model (Selby, Anestis, & Joiner, 2008) suggests that negative affect (such as anger and sadness) may trigger rumination, which in turn may increase the duration and extent of negative affect, leading to dysregulated behaviours aimed at reducing such intense and unpleasant emotions. AIM: The aim of this study is to explore the relationships between emotional dysregulation, anger and depressive ruminations, and their role in predicting dysregulated behaviours (such as aggression and self-harm) in a clinical sample of patients with BPD. METHODS: Ninety-one patients with a diagnosis of BPD were recruited from three outpatient community mental health centres and asked to complete a comprehensive assessment for personality disorder symptoms, emotion dysregulation, anger and depressive ruminations, aggression, and self-harm. RESULTS: Anger and depressive ruminations were found to be significantly associated to, respectively, self-harm and aggression, beyond the variance accounted by emotional dysregulation. CONCLUSIONS: Rumination may act as a mediator between emotional dysregulation and dysregulated behaviours in BPD. Future research should examine whether clinical techniques aimed at reducing rumination may be helpful in reducing dysregulated behaviours in patients with BPD. "This is the pre-peer reviewed version of the following article: Martino, F., Caselli, G., Di Tommaso, J., Sassaroli, S., Spada, M.M ., Valenti, B., Berardi, D., Sasdelli, A and Menchetti, M (2017) Anger and depressive ruminations as predictors of dysregulated behaviours in borderline personality disorder. Clinical Psychology and Psychotherapy., which has been published in final form at 10.1002/cpp.2152 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

    Repression of Esophageal Neoplasia and Inflammatory Signaling by Anti-miR-31 Delivery In Vivo.

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    BACKGROUND: Overexpression of microRNA-31 (miR-31) is implicated in the pathogenesis of esophageal squamous cell carcinoma (ESCC), a deadly disease associated with dietary zinc deficiency. Using a rat model that recapitulates features of human ESCC, the mechanism whereby Zn regulates miR-31 expression to promote ESCC is examined. METHODS: To inhibit in vivo esophageal miR-31 overexpression in Zn-deficient rats (n = 12-20 per group), locked nucleic acid-modified anti-miR-31 oligonucleotides were administered over five weeks. miR-31 expression was determined by northern blotting, quantitative polymerase chain reaction, and in situ hybridization. Physiological miR-31 targets were identified by microarray analysis and verified by luciferase reporter assay. Cellular proliferation, apoptosis, and expression of inflammation genes were determined by immunoblotting, caspase assays, and immunohistochemistry. The miR-31 promoter in Zn-deficient esophagus was identified by ChIP-seq using an antibody for histone mark H3K4me3. Data were analyzed with t test and analysis of variance. All statistical tests were two-sided. RESULTS: In vivo, anti-miR-31 reduced miR-31 overexpression (P = .002) and suppressed the esophageal preneoplasia in Zn-deficient rats. At the same time, the miR-31 target Stk40 was derepressed, thereby inhibiting the STK40-NF-κΒ-controlled inflammatory pathway, with resultant decreased cellular proliferation and activated apoptosis (caspase 3/7 activities, fold change = 10.7, P = .005). This same connection between miR-31 overexpression and STK40/NF-κΒ expression was also documented in human ESCC cell lines. In Zn-deficient esophagus, the miR-31 promoter region and NF-κΒ binding site were activated. Zn replenishment restored the regulation of this genomic region and a normal esophageal phenotype. CONCLUSIONS: The data define the in vivo signaling pathway underlying interaction of Zn deficiency and miR-31 overexpression in esophageal neoplasia and provide a mechanistic rationale for miR-31 as a therapeutic target for ESCC

    ViCTree: an automated framework for taxonomic classification from protein sequences

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    Motivation: The increasing rate of submission of genetic sequences into public databases is providing a growing resource for classifying the organisms that these sequences represent. To aid viral classification, we have developed ViCTree, which automatically integrates the relevant sets of sequences in NCBI GenBank and transforms them into an interactive maximum likelihood phylogenetic tree that can be updated automatically. ViCTree incorporates ViCTreeView, which is a JavaScript-based visualisation tool that enables the tree to be explored interactively in the context of pairwise distance data. Results: To demonstrate utility, ViCTree was applied to subfamily Densovirinae of family Parvoviridae. This led to the identification of six new species of insect virus. Availability: ViCTree is open-source and can be run on any Linux- or Unix-based computer or cluster. A tutorial, the documentation and the source code are available under a GPL3 license, and can be accessed at http://bioinformatics.cvr.ac.uk/victree_web/

    Complete genome sequence of the first KPC-type carbapenemase-positive Proteus mirabilis strain from a bloodstream infection

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    Sequencing of the blaKPC-positive strain Proteus mirabilis AOUC-001 was performed using both the MiSeq and PacBio RS II platforms and yielded a single molecule of 4,272,433 bp, representing the complete chromosome. Genome analysis showed the presence of several acquired resistance determinants, including two copies of blaKPC-2 carried on a fragment of a KPC-producing plasmid previously described in Klebsiella pneumoniae

    ASS1 Overexpression: A Hallmark of Sonic Hedgehog Hepatocellular Adenomas; Recommendations for Clinical Practice.

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    Until recently, 10% of hepatocellular adenomas (HCAs) remained unclassified (UHCA). Among the UHCAs, the sonic hedgehog HCA (shHCA) was defined by focal deletions that fuse the promoter of Inhibin beta E chain with GLI1. Prostaglandin D2 synthase was proposed as immunomarker. In parallel, our previous work using proteomic analysis showed that most UHCAs constitute a homogeneous subtype associated with overexpression of argininosuccinate synthase (ASS1). To clarify the use of ASS1 in the HCA classification and avoid misinterpretations of the immunohistochemical staining, the aims of this work were to study (1) the link between shHCA and ASS1 overexpression and (2) the clinical relevance of ASS1 overexpression for diagnosis. Molecular, proteomic, and immunohistochemical analyses were performed in UHCA cases of the Bordeaux series. The clinico-pathological features, including ASS1 immunohistochemical labeling, were analyzed on a large international series of 67 cases. ASS1 overexpression and the shHCA subgroup were superimposed in 15 cases studied by molecular analysis, establishing ASS1 overexpression as a hallmark of shHCA. Moreover, the ASS1 immunomarker was better than prostaglandin D2 synthase and only found positive in 7 of 22 shHCAs. Of the 67 UHCA cases, 58 (85.3%) overexpressed ASS1, four cases were ASS1 negative, and in five cases ASS1 was noncontributory. Proteomic analysis performed in the case of doubtful interpretation of ASS1 overexpression, especially on biopsies, can be a support to interpret such cases. ASS1 overexpression is a specific hallmark of shHCA known to be at high risk of bleeding. Therefore, ASS1 is an additional tool for HCA classification and clinical diagnosis
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