Biomedical subjects

C W Yen

Publications and source records attributed to C W Yen.

5 recordsLinked to original sources

PubMed2002

A sieving method for collecting the metacercariae of trematode parasites from freshwater fish.

This study describes a sieving method for the collection of metacercariae from frozen (-20 degrees C) freshwater fish. Digested fish tissue is filtered through a series of sieves; the crude filtrate is then centrifuged. Centrifugation produces a sediment from which metacercariae can be removed. Half of the metracercariae that were obtained from the fish meat that had been frozen for 10 days (-20 degrees C) were dead; the other half were alive and some larvae were moving slowly.

Animals↗

PubMed1999

Prevalence and treatment of Pediculus capitis infestation among aboriginal school children in northern Taiwan.

In the present study, pediculosis was investigated among a total of 2,725 children from 35 primary schools in Hsiulin District of Hualien County, Jenai District of Nantou County, Wulai District of Taipei County, Chienshih District of Hsinchu County, Fushing District of Taoyuan County, and Nanao District of Ilan County. The overall infestation rate was 12.8%. The rates by districts were 19.7%, 17.3%, 16.7%, 15.1%, 7.9%, and 3.0%, respectively. The pediculicides including Nix (permethrin 1%) 56 gm/tube, Para aerosol (bioallethrin 0.66%) 90 gm/tube, and Perioderm (malathion 1%) cream shampoo 40 gm/tube were used to treat the head louse infestation in 83, 91, and 103 children; the cure rates were 97.3%, 94.1%, and 93.4%, respectively. No significant differences were found in these rates. The reactions were slight and transitory. A total of 636 lice was collected from the hair using fine-toothed combs before treatment and from the used towels after treatment of children in Wulai, Chienshih, Hsiulin, and Jenai Districts. Each child was found infested with a mean of 7.7 lice. The mean intensity of infestation was highest in Jenai (9.3) and Chienshih (8.7) came next. Wulai (3.7) and Hsiulin (3.6) had lower intensities.

Animals↗

PubMed1999

Urinary tract infection in children.

Two hundred and eighty-five children under 15 years old (169 boys and 116 girls) who had urinary tract infection (UTI) were admitted to our hospital during the period July 1995 to June 1998. Clinical presentation, laboratory data and image studies were recognized and analyzed. Most patients were younger than 2 years of age. Fever is the most common sign, especially in young children. With the urinary dipstick test a low positive rate of nitrite reaction (34.7%) was found. E. coli is the most common pathogen and exclusively resistant to ampicillin (90.2%). The E. coli is also relatively resistant to trimethoprim/sulfamethoxazole (57.1%). Voiding cystourethrogram was performed in 187 cases, in which 24.6% of those patients showed vesicoureteric reflux. Ninety-eight children received 99mTc-dimercaptosuccinic acid renal scans and 62 cases (63.3%) had abnormal findings compatible with pyelonephritis. The positive predictive values by renal ultrasonography for vesicoureteric reflux and pyelonephritis are 30.7% and 78.9%, respectively. In pyelonephritis patients, only 37% also had a vesicoureteric reflux. The fever duration and clinical inflammatory parameters were evaluated in all patients. Longer febrile periods are the risk of vesicoureteric reflux and pyelonephritis, and a high C-reactive protein concentration indicates the risk of pyelonephritis. In conclusion, fever was the most common sign in young UTI children who had a low positive nitrite reaction rate in the dipstick test. E. coli was the most common pathogen with a high ampicillin resistance in Taiwan. Only 37% pyelonephritis patients had refluxing nephropathy. It is indicated that pyelonephritis is not always attributed to reflux of infected urine. A longer febrile period and a high C-reactive protein level are good indicators for prediction of the risk of pyelonephritis in UTI patients.

Adolescent↗

PubMed1997

An adaptive training method for optimal interpolative neural nets.

In contrast to conventional multilayered feedforward networks which are typically trained by iterative gradient search methods, an optimal interpolative (OI) net can be trained by a noniterative least squares algorithm called RLS-OI. The basic idea of RLS-OI is to use a subset of the training set, whose inputs are called subprototypes, to constrain the OI net solution. A subset of these subprototypes, called prototypes, is then chosen as the parameter vectors of the activation functions of the OI net to satisfy the subprototype constraints in the least squares (LS) sense. By dynamically increasing the numbers of subprototypes and prototypes, RLS-OI evolves the OI net from scratch to the extent sufficient to solve a given classification problem. To improve the performance of RLS-OI, this paper addresses two important problems in OI net training: the selection of the subprototypes and the selection of the prototypes. By choosing subprototypes from poorly classified regions, this paper proposes a new subprototype selection method which is adaptive to the changing classification performance of the growing OI net. This paper also proposes a new prototype selection criterion to reduce the complexity of the OI net. For the same training accuracy, simulation results demonstrate that the proposed approach produces smaller OI net than the RLS-OI algorithm. Experimental results also show that the proposed approach is less sensitive to the variation of the training set than RLS-OI.

Algorithms↗

PubMedDate not supplied

STARDUST: finessing expensive cometary sample returns.

The STARDUST Discovery mission will collect samples of cometary coma and interstellar dust and return them to Earth. Five years after launch in February 1999, coma dust in the 1- to 100-micrometers size range will be captured by impact into ultra-low-density silica aerogel during a 6 kms-1 flyby of Comet Wild 2. The returned samples will be investigated at laboratories where the most critical information on these primitive materials is retained. The Jet Propulsion Laboratory will provide project management with Lockheed Martin Astronauts as the spacecraft industrial partner. STARDUST management will aggressively and innovatively achieve cost control through the use of Total Quality Management principles, the chief of which will be organization in a Project Engineering and Integration Team that "flattens" the traditional hierarchical structure by including all project elements from the beginning, in a concurrent engineering framework focusing on evolving Integrated Mission Capability.

Astronomy↗