Estimating Markov-Switching ARMA Models with Extended Algorithms of Hamilton

This paper proposes two innovative algorithms to estimate a general class of N-state Markov-switching autoregressive moving-average (MS-ARMA) models with a sample of size T. To resolve the problem of NT possible routes induced by the presence of MA parameters, the first algorithm is built on Hamilton’s (1989) method and Gray’s (1996) idea of replacing the lagged error terms with their corresponding conditional expectations. We thus name it as the Hamilton-Gray (HG) algorithm. The second method refines the HG algorithm by recursively updating the conditional expectations of these errors and is named as the extended Hamilton-Gray (EHG) algorithm. The computational cost of both algorithms is very mild, because the implementation of these algorithms is very much similar to that of Hamilton (1989). The simulations show that the finite sample performance of the EHG algorithm is very satisfactory and is much better than that of the HG counterpart. We also apply the EHG algorithm to the issues of dating U.S. business cycles with the same real GNP data employed in Hamilton (1989). The turning points identified with the EHG algorithm resemble closely to those of the NBER’s Business Cycle Dating Committee and confirm the robustness of the findings in Hamilton (1989) about the effectiveness of Markov-switching models in dating U.S. business cycles.Markov-switching, ARMA process

RELATIONSHIP BETWEEN THE KINEMATICS OF THE TRUNK AND LOWER EXTREMITIES AND BALL VELOCITY DURING THE OVERHAND THROW IN MALE CANOE POLO PLAYERS

The purpose of this study was to examine the relationship between the motion of the trunk and lower extremities and ball velocity during the overhand throw in canoe polo. Fifteen male national canoe polo team players participated in this study. The overhand throwing motion was captured using a three dimensional motion analysis system. Kinematic and temporal parameters in the trunk and lower extremities were measured and analyzed. Results indicated that five variables were associated with variations in ball velocity. Specifically, as ball velocity increased, canoe polo players showed an increased maximal angular velocity in trunk-tilt sideways, upper torso rotation, and right knee flexion. In addition, the right knee flexion range of motion and time to maximum right knee flexion angular velocity increased as ball velocity increased

Bacterial infection in association with snakebite: A 10-year experience in a northern Taiwan medical center

BackgroundMicrobiological data of secondary wound infections following snakebites is rarely reported in Taiwan. The objective of this study was to assess the secondary wound infection after venomous snakebites.MethodsWe conducted a 10-year retrospective survey on patients admitted for venomous snakebites and microbiological data of wound cultures at a medical center in northern Taiwan.ResultsBetween April 2001 and April 2010, 231 patients who experienced snakebites were included. Male predominated, accounting for 62.3% (144). The age range of patients was 4–95 years. Ninety-five (41.1%) people were bitten by Trimeresurus mucrosquamatus, followed by Tstejnegeri, and cobra. A total of 61 pathogens were obtained from 21 patients. Thirty-nine (63.9%) isolates were gram-negative bacteria, 14 (23%) gram-positive pathogens, and 8 (13.1%) anaerobic pathogens. There were 17 patients bitten by cobra in these 21 patients. Morganella morganii and Enterococcus species were the most common pathogens identified in the wound cultures.ConclusionCobra bite causes more severe bacterial infection than other kinds of snakebites. Oral amoxicillin/clavulanate plus ciprofloxacin or parenteral piperacillin/tazobactam alone can be the choices for empirical or definitive treatment, and surgical intervention should be considered for established invasive soft tissue infections

Highly efficient RF power amplifier for wireless LAN applications

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

KINETIC DIFFERENCES IN LOWER EXTREMITY BETWEEN BASEBALL PITCHING FROM PITCHER’S MOUND AND FLAT-GROUND

The purpose of this study was to investigate the kinetic differences in lower extremity between pitching from a mound and flat-ground. A motion capture system and two force plates were used simultaneously to collect the dynamic data of 8 baseball male pitchers. The results revealed that pitching from the mound generated higher propulsive force at the trailing leg as well as greater braking force and vertical ground reaction force at the lead leg (p< .05). The trailing leg in the mound condition generated greater knee posterior joint force while the lead leg had greater axial joint force at ankle and knee, as well as greater extension moment at ankle, knee and hip (p< .05). It was concluded that pitching from the mound generated higher ground reaction force, which resulted in higher joint forces and moments and thus might increase stresses at lower extremity

Centella asiatica extract protects against amyloid β1–40-induced neurotoxicity in neuronal cells by activating the antioxidative defence system

AbstractCentella asiatica (雷公根 léi gōng gēn) is a traditional medicinal herb with high antioxidant activity, which decreases amyloid-β (Aβ) deposition in the brain. At the same time, aggregated Aβ-induced oxidative stress is the trigger in the pathogenesis of Alzheimer's disease (AD). Here, we investigated the ability of C. asiatica ethanol extract (CAE) to protect PC12 and IMR32 cells from Aβ1–40-induced production of reactive oxygen species (ROS) and concomitant neurotoxicity. Aggregated Aβ1–40 treatment resulted in reduced cell viability, which can be reversed by cotreatment with 25, 50, and 100 μg/mL CAE. Moreover, CAE eliminated the Aβ1–40-mediated increase in ROS production. Thus, CAE-mediated protection against aggregated Aβ1–40-induced neurotoxicity is attributable to modulation of the antioxidative defense system in cells, including the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and levels of glutathione and glutathione disulfide by CAE. This emphasizes the potential therapeutic and preventive value of CAE in the treatment of AD

The resting sites and blood-meal sources of Anopheles minimus in Taiwan

<p>Abstract</p> <p>Background</p> <p>The WHO declared Taiwan free from malaria in 1965, but in 2003 the reporting of two introduced cases in a rural area suggested a possible local transmission of this disease. Therefore, understanding the resting sites and the blood sources of <it>Anopheles minimus </it>is crucial in order to provide information for implementing vector control strategies.</p> <p>Methods</p> <p>During a two-year survey, mosquitoes were collected in houses and their surrounding areas and at the bank of larval habitats by backpack aspirators in 17 villages in rural areas of southern and eastern Taiwan for 1 hr. On the same day, blacklight traps were hung downward overnight. Blood-fed mosquito samples were analysed by PCR.</p> <p>Results</p> <p>Of the 195 total households surveyed by backpack aspirators, no <it>Anopheles </it>adults were collected inside the houses, while a single <it>Anopheles minimus </it>and a single <it>Anopheles maculatus </it>were collected outside of the houses. On the same day, 23 <it>An. minimus</it>, two <it>An. maculatus</it>, two <it>Anopheles ludlowae</it>, two <it>Anopheles sinensis</it>, and one <it>Anopheles tessellatus </it>were collected along the bank of larval habitats. In blacklight traps hung outside of the houses in the villages, 69 <it>An. minimus</it>, 62 <it>An. ludlowae</it>, 31 <it>An. sinensis</it>, and 19 <it>An. maculatus </it>were collected. In larval habitats, 98 <it>An. ludlowae</it>, 64 <it>An. minimus</it>, 49 <it>An. sinensis</it>, and 14 <it>An. maculatus </it>were collected. Of a total of 10 blood-fed samples, <it>An. minimus </it>fed on four animals including bovine (60%), dogs (20%), pig (10%), and non-chicken avian (10%).</p> <p>Conclusion</p> <p><it>Anopheles minimus</it>, an opportunist feeder in Taiwan, was not collected inside the houses, but was found outside of the houses in villages and surrounding larval habitats. Therefore, an outdoor transmission of malaria is likely to occur and, thus, the bed nets, which are favoured for controlling the late biting of <it>An. minimus</it>, should be a very efficient and effective method for those local residents who sleep outdoors. Additionally, space spray of insecticides for <it>Anopheles </it>at night, as well as residual spray inside animal huts and selective larval habitats, are also helpful to control female adults.</p