1,721,154 research outputs found
Maxillary expansion effects on mandibular transverse dimension: Comparison of different activation protocols
No full textThe purpose of this prospective study was to investigate medium-term indirect effects of Maxillary Expansion (RME) therapy on mandibular arch dimensions using two different clinical protocol activation. Sixty patients in mixed dentition (mean age 7.8 y) showing maxillary deficiency and/or unilateral or bilateral cross-bite were treated with RPE (Haas type) on second deciduous molars. For patient in RME group (rapid maxillary expansion), treatment protocol consisted of 2 turns per day: For patient in SME (slow maxillary expansion) group treatment protocol consisted of 2 turns per week. Study models were taken before (T1) and after expansion (T2) with 12 ± 4 months interval. Dental cast were digitized with a 3D scanner (3Shape, DK) and a set of landmarks was digitized on each digital model. Mandibular intermolar distance (MID), mandibular molar torque (MMT), mandibular intercanine distance (MIcD) and mandibular canine torque (MCT) were assessed. At T1, no differences at baseline were found between groups. At T2, in RME group, mandibular intermolar distance (MID) increased 1.2 mm and MMT increased 6.5°. In SME group MID increased 1.3 mm and mandibular molar torque (MMT) increased 6.2°. There was a significant effect on mandibular intercanine distance (MIcD) (RME +0.8 mm, SME +0.9 mm) and on and mandibular canine torque (MCT) (RME +3.4°, SME +3.8°). The improvement in transversal and torque measurement did not differ between groups. In conclusion, both rapid and slow maxillary expansion protocols have a significant medium-term widening effect on the mandibular first molars and canines
Rheumatoid factor: a novel determiner in cancer history
Full text linkThe possible interplay between autoimmunity and cancer is a topic that still needs to be deeply explored. Rheumatoid factors are autoantibodies that are able to bind the constant regions (Fc) of immunoglobulins class G (IgGs). In physiological conditions, their production is a transient event aimed at contributing to the elimination of pathogens as well as limiting a redundant immune response by facilitating the clearance of antibodies and immune complexes. Their production can become persistent in case of different chronic infections or diseases, being for instance a fundamental marker for the diagnosis and prognosis of rheumatoid arthritis. Their presence is also associated with aging. Some studies highlighted how elevated levels of rheumatoid factors (RFs) in the blood of patients are correlated with an increased cancer risk, tumor recurrence, and load and with a reduced response to anti-tumor immunotherapies. In line with their physiological roles, RFs showed in different works the ability to impair in vitro anti-cancer immune responses and effector functions, suggesting their potential immunosuppressive activity in the context of tumor immunity. Thus, the aim of this review is to investigate the emerging role of RFs as determiners of cancer faith
New methodologies for the documentation of fortified architecture in the state of ruins
No full textFortresses and castles are important symbols of social and cultural identity providing tangible evidence of cultural unity in Europe. They are items for which it is always difficult to outline a credible prospect of reuse, their old raison d'être- namely the military, political and economic purposes for which they were built- having been lost. In recent years a Research Unit of the University of Bologna composed of architects from different disciplines has conducted a series of studies on fortified heritage in the Emilia Romagna region (and not only) often characterized by buildings in ruins. The purpose of this study is mainly to document a legacy, which has already been studied in depth by historians, and previously lacked reliable architectural surveys for the definition of a credible as well as sustainable conservation project. Our contribution will focus on different techniques and methods used for the survey of these architectures, the characteristics of which- in the past- have made an effective survey of these buildings difficult, if not impossible. The survey of a ruin requires, much more than the evaluation of an intact building, reading skills and an interpretation of architectural spaces to better manage the stages of documentation and data processing. Through a series of case studies of fortified buildings in ruins, we intend to describe the reasons that guided the choice of the methods and tools used and to highlight the potentials and the limits of these choices in financial terms
The impact of energy prices on clean energy stock prices. A multivariate quantile dependence approach
No full textWe assess the impact of quantile price movements in oil, gas, coal and electricity on the quantiles of clean energy stock returns using a multivariate vine-copula dependence setup. For the period 2009 – 2016, our evidence shows that oil and electricity prices were major contributors to the dynamics of clean energy stock returns in the USA and the EU, respectively, whereas the other energy prices played a minor role in shaping clean energy stock returns. Furthermore, we find evidence of a symmetric energy price impact, so extreme upward and downward energy price movements had a similar impact on clean energy stock returns. This evidence has potential implications for risk management decision making by energy investors and for policy maker decisions regarding support for clean energy deployment
Downside/upside price spillovers between precious metals: A vine copula approach
No full textWe studied downside and upside price spillovers between four precious metals (gold, silver, platinum and palladium), characterizing the multivariate dependence structure using a vine copula model and computing downside and upside value-at-risk and conditional value-at-risk. We found that the dependence structure differed across precious metals, all of which displayed different average and tail dependence features. Gold and silver prices were highly dependent except at the upper tail, whereas silver prices were integrated with those for platinum and palladium except at the upper tail. The gold market was very little integrated with the platinum and palladium markets. We document asymmetric downside and upside price spillover effects that differed in magnitude across precious metals; silver, in particular, had a greater downside and upside price impact on gold. Our results, indicating that precious metals do not behave as a single asset class, have implications for risk management, trading and hedging strategies for portfolios that include precious metals
The impact of Twitter sentiment on renewable energy stocks
No full textWe study the impact of Twitter sentiment and sentiment divergence on returns, volatility and trading volumes for renewable energy stocks. Based on daily time series for Twitter sentiment and Twitter sentiment divergence, we estimate VAR models and evaluate spillovers between sentiment and renewable energy stock pricing and trading. We find that whereas Twitter sentiment has no sizeable impact on returns, volatility or trading volumes, Twitter sentiment divergence generates feedback effects on volatility and trading volumes. Our evidence would indicate that the wisdom of the Twitter crowd is not substantial in shaping prices and trading for renewable energy companies
Quantile causality between gold commodity and gold stock prices
No full textWe found mixed evidence regarding quantile causality from gold commodity to gold stock returns for global, regional and individual country gold stock price indices. More specifically, gold prices Granger-caused Australian gold stock returns in all quantiles, but there was no quantile causality for either gold stock returns for companies located in the Europe-Middle East-Africa regions or the upper quantiles of companies located in America. In contrast, we found consistent evidence of quantile causality from gold stock returns to gold prices. These results would indicate that gold price shocks do not translate directly into wealth shocks for gold companies and that investors and risk managers could use the information regarding gold commodity and gold stock prices to improve decision making
Price connectedness between green bond and financial markets
No full textWe study price connectedness between the green bond and financial markets using a structural vector autoregressive (VAR) model that captures direct and indirect transmission of financial shocks across markets. Using heteroskedasticity to identify the structural VAR model parameters, our empirical findings reveal that the green bond market is closely linked to the fixed-income and currency markets, receiving sizeable price spillovers from those markets and transmitting negligible reverse effects. We also show that, in contrast, the green bond market is weakly tied to the stock, energy and high-yield corporate bond markets. These findings have implications in terms of portfolio and risk management decisions for environmentally aware investors holding positions in green bonds
Systemic risk of Spanish listed banks: a vine copula CoVaR approach
No full textWe measured the systemic impact of financial distress in a Spanish listed bank on other listed banks and on the European financial system, using conditional value at risk (CoVaR) as a systemic risk measure. We modelled multivariate dependence between listed banks using a hierarchical tree structure given by a vine copula model and, using bivariate copulas, dependence between listed banks and the European financial system. For the period January 2003 to March 2015, systemic risk dramatically increased around the time of the recent global financial crisis and, to a lesser extent, around the time of the European debt crisis. BBVA played a predominant role as it both transmitted and received systemic risk to and from the remaining listed banks. Santander played a minor role and the smallest banks, Sabadell and Bankinter, did not play any pivotal role, not even between themselves. Finally, the main systemic impact of the Spanish banks on the European financial systems originated in BBVA, Popular and Santander, with the other listed banks playing a minor role in risk transmission. These results have implications for the regulation of capital in financial institutions and for investor risk management decisions
The impact of downward/upward oil price movements on metal prices
No full textWe examine the impact of large upward/downward oil price movements on metal prices and the asymmetric response of metal prices to large oil price movements. We use copulas to characterize dependence between oil and metal price returns and we quantify spillover effects by computing the unconditional and conditional value-at-risk. Taking price data for ten metals - six industrial (aluminium, copper, lead, nickel, tin and zinc) and four precious (gold, silver, palladium and platinum) - widely traded on the London Metal Exchange for the period 2000 to 2015, our empirical evidence indicates that large downward and upward oil price movements had spillover effects on all these metals both before and after the outbreak of the global financial crisis. The fact that spillovers for upward oil price movements were larger than for downward oil price movements provides evidence of asymmetric spillover effects. Our results have implications for downside and upside risk management for investors and manufacturers
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