16 research outputs found
Uncertainty in firm valuation and a cross-sectional misvaluation measure
The degree of uncertainty associated with the value of a company plays a relevant role in valuation analysis. We propose an original and robust methodology for company market valuation, which replaces the traditional point estimate of the conventional Discounted Cash Flow model with a probability distribution of fair values that convey information about both the expected value of the company and its intrinsic uncertainty. Our methodology depends on two main ingredients: an econometric model for company revenues and a set of firm-specific balance sheet relations that are estimated using historical data. We explore the effectiveness and scope of our methodology through a series of statistical exercises on publicly traded U.S. companies. At the firm level, we show that the fair value distribution derived with our methodology constitutes a reliable predictor of the company’s future abnormal returns. At the market level, we show that a long-short valuation (LSV) factor, built using buy-sell recommendations based on the fair value distribution, contains information not accessible through the traditional market factors. The LSV factor significantly increases the explanatory and the predictive power of factor models estimated on portfolios and individual stock returns
The Impact of Heterogeneous Trading Rules on the Limit Order Book and Order Flows
In this paper we develop a model of an order-driven market where traders set bids and asks and post market or limit orders according to exogenously fixed rules. Agents are assumed to have three components to the expectation of future asset returns, namely-fundamentalist, chartist and noise trader. Furthermore agents differ in the characteristics describing these components, such as time horizon, risk aversion and the weights given to the various components. The model developed here extends a great deal of earlier literature in that the order submissions of agents are determined by utility maximisation, rather than the mechanical unit order size that is commonly assumed. In this way the order flow is better related to the ongoing evolution of the market. For the given market structure we analyze the impact of the three components of the trading strategies on the statistical properties of prices and order flows and observe that it is the chartist strategy that is mainly responsible of the fat tails and clustering in the artificial price data generated by the model. The paper provides further evidence that large price changes are likely to be generated by the presence of large gaps in the book
Pentraxin 3 plasma levels at graft-versus-host disease onset predict disease severity and response to therapy in children given haematopoietic stem cell transplantation
Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study
BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348
Imbalance between angiogenic and anti-angiogenic factors in sera from patients with large-vessel vasculitis
Objective. To investigate serum levels of a panel of angiogenic inducers (VEGF, FGF-2, Angiopoietin 1, -2, soluble
VCAM-1) and inhibitors (angiostatin, endostatin, pentraxin-3) in patients with giant cell arteritis (GCA) and Takayasu’s
arteritis (TAK), in order to gain further insights into the molecular mechanisms driving angiogenesis dysregulation in
large-vessel vasculitis (LVV).
Methods. Sera were obtained from 33 TAK patients and 14 GCA patients and from two groups of age-matched
normal controls (NC). Disease activity was assessed using 18F-FDG PET/CT and clinical indices including NIH/
Kerr criteria and ITAS. Angiogenic and anti-angiogenic factor serum levels were evaluated using commercial ELISA kits. Pentraxin 3 (PTX3) serum levels were evaluated by non-commercial ELISA, as already described.
Results. Among the angiogenic factors, only VEGF serum levels were significantly higher in TAK patients compared
to NC. No difference was found between angiogenic factor levels in GCA patients compared to those detected in NC. Anti-angiogenic factor (Angiostatin, Endostatin, PTX3) serum levels were significantly higher in both GCA and TAK
patients compared to NC. Significant associations were observed between VEGF and PTX3 levels and disease
activity evaluated using PET scan and clinical indices. Cluster analysis based on PET scan scores in TAK patients
showed significant ordered differences in VEGF and angiostatin serum levels. Indeed, we noted a progressive increase of VEGF and angiostatin from NC to the cluster including patients with the highest and more diffuse scan positivity.
Conclusion. Our overall results demonstrate a circulating molecular profile characterised by a prevailing expression
of anti-angiogenic soluble factors