Errors of Upright Perception in Patients With Vestibular Migraine

Patients with vestibular migraine (VM) often report dizziness with changes in the head or body position. Such symptoms raise the possibility of dysfunction in neural mechanisms underlying spatial orientation in these patients. Here we addressed this issue by investigating the effect of static head tilts on errors of upright perception in a group of 27 VM patients in comparison with a group of 27 healthy controls. Perception of upright was measured in a dark room using a subjective visual vertical (SVV) paradigm at three head tilt positions (upright, ±20°). VM patients were also surveyed about the quality of their dizziness and spatial symptoms during daily activities. In the upright head position, SVV errors were within the normal range for VM patients and healthy controls (within 2° from true vertical). During the static head tilts of 20° to the right, VM patients showed larger SVV errors consistent with overestimation of the tilt magnitude (i.e., as if they felt further tilted toward the right side) (VM: −3.21° ± 0.93 vs. Control: 0.52° ± 0.70; p = 0.002). During the head tilt to the left, SVV errors in VM patients did not differ significantly from controls (VM: 0.77° ± 1.05 vs. Control: −0.04° ± 0.68; p = 0.52). There was no significant difference in SVV precision between the VM patients and healthy controls at any head tilt position. Consistent with the direction of the SVV errors in VM patients, they largely reported spatial symptoms toward the right side. These findings suggest an abnormal sensory integration for spatial orientation in vestibular migraine, related to daily dizziness in these patients

Does the Combination of Acute Hearing Loss and Vertigo Increase Stroke Risk?

Hearing loss is often thought of as an inner ear ("peripheral") symptom, but SHL can be an initial manifestation of posterior circulation stroke ("central"), especially when co-occurring with vertigo. To date, no large-scale study has compared stroke risk across the following populations: (1) "sudden hearing loss (SHL) alone;" (2) "vertigo alone;" and (3) "SHL with vertigo." Here we compare long-term stroke risk among these patients using a large national healthcare database

Evaluating the Context-Dependent Total-Factor Energy Efficiency of Counties and Cities in Taiwan

This paper applies the context-dependent total-factor energy efficiency (CD-TFEE) to determine the multi-layer disaggregate energy efficiency frontiers of twenty administrative regions in Taiwan for the year of 2016. The CD-TFEE overcomes the shortcoming of conventional TFEE index that TFEE is not able to find the “closest target” for each inefficient region in the short run. Furthermore, the CD-TFEE scores here deal with four types of energy inputs (electricity for production, electricity for household and non-household lighting, diesel sales, and gasoline sales), illustrating that multi-layer TFEE frontiers for each energy input in the case of Taiwan can be computed. Empirical results indicate that there are three levels of TFEE frontiers for electricity for production and four levels for other types of energy inputs. In addition, New Taipei City, Taipei City, Keelung City, and Penghu County are at the top level of TFEE frontier for all four energy inputs. This paper also demonstrates that the CD-TFEE procedure generates results different from the CD-DEA introduced by Seiford and Zhu (2003)

A comprehensive analysis of the effects of risk measures on bank efficiency: Evidence from emerging Asian countries

This study investigates the role of risk in determining the cost efficiency of international banks in eight emerging Asian countries. Researchers of this paper consider three distinct risk aspects under a total of eight risk measures: credit risk, operational risk, and market risk. We apply a heteroscedastic stochastic frontier model to estimate bank cost efficiency in our analysis. Additionally, this study analyzes the marginal effects of all risk measures on the inefficiency effect in order to explore a more detailed relationship between risks and efficiency. The empirical results indicate that the risk measures represent significant effects on both the level and variability of bank efficiency. We also find that these effects vary across countries and over time.Credit risk Operational risk Market risk Cost efficiency Stochastic frontier analysis Marginal effects

Decomposition of mutual fund underperformance

This article follows a three-stage data envelopment analysis (DEA) approach proposed by Fried et al. (2002) to decompose mutual fund underperformance, in order to obtain pure managerial performance. In the first stage, DEA is used to compute each fund's performance. In the second stage, a stochastic frontier regression decomposes fund underperformance into characteristics (including fund and management attributes), managerial inefficiency, and statistical noise. In the third stage, DEA with slack-adjusted data is used to find out the pure performance. It is found that a fund's performance significantly increases with its size, previous performance, manager's tenure and education, while it decreases with the age of the fund and number of managed funds.

Incorporating a leading indicator into the trading rule through the Markov-switching vector autoregression model

This article examines the profitability of trading rules based on the smoothed probability of Markov-switching models and executes two models in Taiwan's case. The results present that both proposed models can earn excess returns over the buy-and-hold strategy and support that both can be used to trade. However, the univariate Markov-switching model, which only uses daily returns series does not successfully capture the trend in the stock market, especially during a bull market. This implies that high-frequency returns series contain lots of noises. In order to overcome this problem, the Markov-switching vector autoregression model that combines a leading indicator and returns is performed in this study. The results indicate a better trading pattern. We conclude that the leading indicator chosen from open interest in the future market increases useful information and reduces noises to improve model estimation, which can well identify the position of bull and bear markets.

Causal relationship between spot and futures prices with multiple time horizons: A nonparametric wavelet Granger causality test

This study investigates the causal information flow between 45 major daily spot returns and their corresponding futures in developing, emerging, and commodity indices through a novel nonparametric wavelet Granger causality test (NWGC) that is capable of detecting causality patterns in various time scales without any stationarity assumption or multivariate autoregressive modeling requirement. We provide new evidence for a complex causality pattern phenomenon. First, there may not be just one dichotomous answer about the Granger causality test for each market data in a time domain, as markets exhibit different causal information flows for different time scales. Second, each market may show distinct causality patterns compared to other markets

The effect of the movement in 52-week high on momentum profit: The evidence from Taiwan

Purpose: This paper aims to examine the impact of price movements in 52-week highs on a 52-week high momentum strategy. This study refers to the upward or downward movement in 52- week highs as an updating effect and determines how this effect influences the profitability of the original 52-week high momentum strategy. Design/methodology/approach: This paper decomposes the ratio of stock price to 52-week high into denoted two components: price change and updating components. We construct two momentum strategies, each focusing on adjusting either the price change or the updating component. Additionally, we employ a portfolio approach and Fama-MacBeth regression analysis to investigate the profitability of each proposed momentum strategy. Findings: The empirical results reveal that removing the price change component (updating component) from the original 52-week high measure can increases (decreases) the momentum profit, implying that the updating component dominates the price change component. Moreover, our analysis shows that when a high ratio of stock price to 52-week high is driven by a downward updating event, the subsequent positive momentum for a winner portfolio is more substantial. Research limitations/implications: This paper investigates the influence of 52-week highs movement on momentum strategies, utilizing data from Taiwan stock market. The findings reveal that accounting for the updating effect of 52-week highs can enhance the profitability of the original momentum strategy. However, it is important to note that this conclusion is currently limited to relatively inefficient stock markets. The impact on relatively efficient markets remains an area that requires further research for a comprehensive understanding. Originality/value: The finance literature widely acknowledges the 52-week high price as a reference point that can impact investors' trading psychology. Numerous empirical studies have confirmed the profitability of the 52-week high momentum investing strategy. However, these studies have not thoroughly explored the implications and effects of price movements within the scope of a 52-week high momentum strategy. Taking behavioral perspectives into account, this paper considers that the updating of 52-week high prices can influence investors' attention and subsequently impact the profitability of the momentum strategy