Stigma scale of epilepsy - Validation process

Purpose: To validate a Stigma Scale of Epilepsy (SSE). Methods: The SSE was completed by 40 adult with epilepsy attending an Outpatient Epilepsy Clinic at the University Hospital of UNICAMP, and by 40 people from the community. People were interviewed on an individual basis; a psychologist read the questions to the subjects who wrote the answers in a sheet. The procedure was the same for all the subjects and completion took around ten minutes. Results: The SSE has 24 items. The internal consistency of the SSE showed alpha. Cronbach's coefficient 0.88 for the patients with epilepsy and 0.81 for the community. The overall mean scores of the Stigma Scale of Epilepsy formula were: 46 (SD=18.22) for patients and 49 (SD=13.25) for the community where a score of 0 would suggest no stigma, and 100 maximum stigma. Discussion: The SSE has satisfactory content validity and high internal consistency. It allows the quantification of the perception of stigma by patients and people from community; this can then be used for interventional studies, such as mass media campaign in minimizing the negative facets of stigma

Preparation of C2-Symmetric Biaryl Bisiminium Salts and Their Use as Organocatalysts for Asymmetric Epoxidation

Two C2-symmetric bisiminium salt species containing biphenylazepinium units and derived from two chiral diamines were prepared and tested as organocatalysts for asymmetric epoxidation

Muscle strength and mortality while on a liver transplant waiting list

OBJETIVO: Avaliar a força de músculos respiratórios e de mão em pacientes na lista de espera para o transplante de fígado e associá-los a mortalidade. MATERIAIS E MÉTODOS: Foram estudados retrospectivamente 132 pacientes submetidos à avaliação fisioterapêutica de rotina e que esperavam o transplante de fígado. A força dos músculos ventilatórios foi avaliada por meio das pressões inspiratória e expiratória máximas e a força do membro superior por meio de dinamometria. Os pacientes foram divididos em dois grupos: grupo A, com 51 pacientes (14 mulheres, 50,1±12,3 anos) que morreram enquanto estavam na lista de espera e grupo B, com 81 pacientes (31 mulheres, 45,0±3,8 anos) que sobreviveram até o transplante de fígado. Foi utilizado o teste de t de Student com nível de significância de 5%. RESULTADOS: Os valores médios da pressão inspiratória máxima (PImax) dos grupos A e B foram 65,7±28,0 e 77,5±33,8mmHg (p=0,04), respectivamente, e as pressões expiratórias máximas foram 72,9±32,9 e 84,4±33,1mmHg (p=0,07), respectivamente. Os valores médios da força da mão esquerda dos grupos A e B foram 18,5±8,1 e 21,5±10,5kgf (p=0,08), respectivamente, e da força da mão direita foram 20,2±9,7 e 23,5±12,5kgf (p=0,10), respectivamente. CONCLUSÕES: A PImax é menor nos pacientes que morreram enquanto aguardavam o transplante. No mesmo grupo, foi observado que a pressão expiratória máxima e a força da mão direita e esquerda foram menores, apesar de não apresentarem diferenças estatisticamente significante.OBJECTIVE: To evaluate respiratory muscle strength and hand strength in patients on a liver transplant waiting list and to associate these with mortality. METHODS: one hundred and thirty-two patients who underwent routine physical therapy evaluation while waiting for liver transplantation were studied retrospectively. Respiratory muscle strength was assessed by measuring the maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), and upper-limb strength was evaluated by dynamometry. The patients were divided into two groups: group A, consisting of 51 patients (14 females, 50.1±12.3 years) who died while on the waiting list; and group B, consisting of 81 patients (31 females, 45.0±3.8 years) who survived until the time of liver transplant. Student’s t test was used with a 5% significance level. RESULTS: The mean MIP values for groups A and B were 65.7±28.0 and 77.5±33.8mmHg (p=0.04), respectively, and the mean MEP values were 72.9±32.9 and 84.4±33.1mmHg (p=0.07), respectively. The mean values for left-hand strength in groups A and B were 18.5±8.1 and 21.5±10.5kgf (p=0.08), and the mean values for right-hand strength were 20.2±9.7 and 23.5±12.5kgf (p=0.10), respectively. CONCLUSIONS: MIP was lower in the patients who died while waiting for liver transplantation. In the same group, it was observed that the MEP values and right and left-hand strength were numerically lower, although they did not reach statistically significant differences

The US stock market leads the Federal funds rate and Treasury bond yields

Using a recently introduced method to quantify the time varying lead-lag dependencies between pairs of economic time series (the thermal optimal path method), we test two fundamental tenets of the theory of fixed income: (i) the stock market variations and the yield changes should be anti-correlated; (ii) the change in central bank rates, as a proxy of the monetary policy of the central bank, should be a predictor of the future stock market direction. Using both monthly and weekly data, we found very similar lead-lag dependence between the S&P500 stock market index and the yields of bonds inside two groups: bond yields of short-term maturities (Federal funds rate (FFR), 3M, 6M, 1Y, 2Y, and 3Y) and bond yields of long-term maturities (5Y, 7Y, 10Y, and 20Y). In all cases, we observe the opposite of (i) and (ii). First, the stock market and yields move in the same direction. Second, the stock market leads the yields, including and especially the FFR. Moreover, we find that the short-term yields in the first group lead the long-term yields in the second group before the financial crisis that started mid-2007 and the inverse relationship holds afterwards. These results suggest that the Federal Reserve is increasingly mindful of the stock market behavior, seen at key to the recovery and health of the economy. Long-term investors seem also to have been more reactive and mindful of the signals provided by the financial stock markets than the Federal Reserve itself after the start of the financial crisis. The lead of the S&P500 stock market index over the bond yields of all maturities is confirmed by the traditional lagged cross-correlation analysis.Comment: 12 pages, 7 figures, 1 tabl

Multiple shifts and fractional integration in the us and uk unemployment rates

This paper analyses the long-run behaviour of the US and UK unemployment rates by testing for possibly fractional orders of integration and multiple shifts using a sample of over 100 annual observations. The results show that the orders of integration are higher than 0 in both series, which implies long memory. If we assume that the underlying disturbances are white noise, the values are higher than 0.5, i.e., nonstationary. However, if the disturbances are autocorrelated, the orders of integration are in the interval (0, 0.5), implying stationarity and mean-reverting behaviour. Moreover, when multiple shifts are taken into account, unemployment is more persistent in the US than in the UK, implying the need for stronger policy action in the former to bring unemployment back to its original level

Dynamic modeling of mean-reverting spreads for statistical arbitrage

Statistical arbitrage strategies, such as pairs trading and its generalizations, rely on the construction of mean-reverting spreads enjoying a certain degree of predictability. Gaussian linear state-space processes have recently been proposed as a model for such spreads under the assumption that the observed process is a noisy realization of some hidden states. Real-time estimation of the unobserved spread process can reveal temporary market inefficiencies which can then be exploited to generate excess returns. Building on previous work, we embrace the state-space framework for modeling spread processes and extend this methodology along three different directions. First, we introduce time-dependency in the model parameters, which allows for quick adaptation to changes in the data generating process. Second, we provide an on-line estimation algorithm that can be constantly run in real-time. Being computationally fast, the algorithm is particularly suitable for building aggressive trading strategies based on high-frequency data and may be used as a monitoring device for mean-reversion. Finally, our framework naturally provides informative uncertainty measures of all the estimated parameters. Experimental results based on Monte Carlo simulations and historical equity data are discussed, including a co-integration relationship involving two exchange-traded funds.Comment: 34 pages, 6 figures. Submitte

Is eco-efficiency in greenhouse gas emissions converging among European Union countries?

Eco-efficiency refers to the ability to produce more goods and services with less impact on the environment and less consumption of natural resources. This issue has become a matter of concern that is receiving increasing attention from politicians, scientists and researchers. Furthermore, greenhouse gases emitted as a result of production processes have a marked impact on the environment and are also the foremost culprit of global warming and climate change. This paper assesses convergence in eco-efficiency in greenhouse gas emissions in the European Union. Eco-efficiency is assessed at both country and greenhouse-gas-specific levels using Data Envelopment Analysis techniques and directional distance functions, as recently proposed by Picazo-Tadeo et al. (Eur J Oper Res, 220:798–809, 2012). Convergence is then evaluated using the Phillips and Sul (Econometrica, 75:1771–1855, 2007) approach that allows testing for the existence of convergence groups. Although the results point to the existence of different convergence clubs depending on the specific pollutant considered, they signal the existence of at least four clear groups of countries. The first two groups are core European Union high-income countries (Benelux, Germany, Italy, Austria, the United Kingdom and Scandinavian countries). A third club is made up of peripheral countries (Spain, Ireland, Portugal and Greece) together with some Eastern countries (Latvia and Slovenia), while the remaining clubs consist of groups containing Eastern European countries

Fixed bandwidth inference for fractional cointegration

In a fractional cointegration setting we derive the fixed bandwidth limiting theory of a class of estimators of the cointegrating parameter which are constructed as ratios of weighted periodogram averages. These estimators offer improved limiting properties over those of more standard approaches like OLS or NBLS estimation. These advantages have been justified by means of traditional asymptotic theory and here we explore whether these improvements still hold when considering the alternative fixed bandwidth theory and, more importantly, whether this latter approach provides a more accurate approximation to the sampling distribution of the corresponding test statistics. This appears to be relevant, especially in view of the typical oversizing displayed by Wald statistics when confronted to the standard limiting theory. A Monte Carlo study of finite-sample behaviour is included

Boundary limit theory for functional local to unity regression

This paper studies functional local unit root models (FLURs) in which the autoregressive coefficient may vary with time in the vicinity of unity. We extend conventional local to unity (LUR) models by allowing the localizing coefficient to be a function which characterizes departures from unity that may occur within the sample in both stationary and explosive directions. Such models enhance the flexibility of the LUR framework by including break point, trending, and multi-directional departures from unit autoregressive coefficients. We study the behavior of this model as the localizing function diverges, thereby determining the impact on the time series and on inference from the time series as the limits of the domain of definition of the autoregressive coefficient are approached. This boundary limit theory enables us to characterize the asymptotic form of power functions for associated unit root tests against functional alternatives. Both sequential and simultaneous limits (as the sample size and localizing coefficient diverge) are developed. We find that asymptotics for the process, the autoregressive estimate, and its $t$ statistic have boundary limit behavior that differs from standard limit theory in both explosive and stationary cases. Some novel features of the boundary limit theory are the presence of a segmented limit process for the time series in the stationary direction and a degenerate process in the explosive direction. These features have material implications for autoregressive estimation and inference which are examined in the paper