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Biomedical subjects

M K Gardner

Publications and source records attributed to M K Gardner.

10 recordsLinked to original sources
PubMed2000

Negative transfer errors in sequential cognitive skills: strong-but-wrong sequence application.

Three experiments investigated the role of processing sequence knowledge in negative transfer within multistep cognitive skills. In Experiments 1 and 2, more training resulted in higher error rates when new processing sequences that resembled familiar ones were introduced in transfer. Transfer error responses were executed with the same speed as correct responses to familiar sequence trials, and the errors appeared to be undetected by the performers. Experiment 3 tested whether the effects of sequence learning were attributable to explicit or implicit knowledge of processing sequences. Evidence favored the implicit learning interpretation. Findings are discussed in relationship to earlier demonstrations of the einstellung effect and to current taxonomic theories of human error.

Adolescent↗
PubMed1990

Componential analysis as a way to investigate age-related changes in information processing.

The purpose of this paper is to alert researchers to the methods and utility of componential analysis as a means to examine age-related changes within information processing models of cognition. This analysis allows the researcher to determine which hypothesized information processing components are significant and the amount of variance shared with the dependent variable(s). Individual differences are investigated by modeling data at the individual subject level. Unstandardized regression weights are correlated with performance on a number of standardized ability tests to determine which components contribute to which abilities. The procedure combines complementary aspects of information processing analysis and psychometric analysis. Componential analysis is illustrated in this study with data from 60 individuals, aged 20 to 79, who solved verbal forced-choice analogies of the form A:B::C: (D1 or D2). Solution time and error rate data were modeled using a regression model developed by Sternberg (1977).

Adult↗
PubMed1989

Analogical reasoning abilities of recovering alcoholics.

This study investigated analogical reasoning abilities of alcoholics who had been abstinent from alcohol for at least 1 year. Their performance was compared to that of nonalcoholic controls matched as a group for education, age, and gender. Solution times and error rates were modeled using a regression model. Results showed a nonsignificant trend for alcoholics to be faster, but more error prone, than controls. The same componential model applied to both groups, and fit them equally well. Although differences have been found in analogical reasoning ability between controls and alcoholics immediately following detoxification, we find no evidence of differences after extended periods of sobriety.

Adult↗
PubMed1988

Superior leukocyte separation with a discontinuous one-step Ficoll-Hypaque gradient for the isolation of human neutrophils.

A discontinuous gradient system composed of two commercially available Ficoll-Hypaque mixtures (Mono-Poly resolving medium (MPRM) and Histopaque 1.077) is described for the purification of mononuclear and polymorphonuclear leukocytes from human blood. Like the original one-step Hypaque-Ficoll procedure (Ferrante and Thong, 1978), a single centrifugation at 500 X g for 30 min resulted in the formation of two distinct leukocyte fractions. In contrast to MPRM alone, the discontinuous system (MPRM-HP) was capable of resolving leukocyte fractions from blood volumes as small as 1 ml with excellent purity and yield. MPRM-HP was also compatible with a wider range of anticoagulants and permitted fractionation of specimens resistant to MPRM.

Adult↗
PubMed1987

Longitudinal study of rotavirus infection and gastroenteritis in families served by a pediatric medical practice: clinical and epidemiologic observations.

During 29 months of prospective longitudinal study of diarrhea in the home, human rotaviruses (HRVs) infected one or more members in 51% of 65 families, 35 of 126 children (28%) and 16 of 124 adults (13%). Within the 33 affected families, 57% of 62 children and 25% of 65 adults were infected. HRV gastroenteritis peaked at 40/100 person years at ages 12 to 23 months and decreased to 5 episodes/100 person years in adults. Among 25 children 0 through 36 months of age who had HRV infection, 88% were symptomatic. Of the 22 children with symptomatic HRV infection, 1 required hospitalization and 8 were seen by their physician for supportive care. HRVs were found in 12% of 216 stools obtained during gastrointestinal illness, but in only 0.2% of 1238 non-illness stools tested. HRV infections were noted as early as October and as late as April. Of 33 families who were studied for 2 seasons, at least 1 individual in each of 3 families experienced HRV infections in both years, but only one, an adult, shed virus and had symptoms in both seasons.

Adolescent↗
PubMed1985

Fecal adenoviruses from a longitudinal study of families in metropolitan Washington, D.C.: laboratory, clinical, and epidemiologic observations.

During a 29-month period, we studied enteric infection in 70 families from a pediatric practice in suburban Washington, D.C. Fecal adenoviruses were detected in stools of 18 patients by tissue culture and electron microscopic procedures. From 6 through 11 months of age, the incidence of fecal adenoviruses associated with enteritis was seven per 100, and of confirmed enteric adenoviruses (EAds), three per 100 individuals per year. All EAds belonged to subgenus G (type 41). All three patients with EAds had diarrhea; two had vomiting and one had fever, but none required hospitalization. Ten of the 15 patients with non-EAds were younger than 2 years, and 60% had diarrhea, 40% had vomiting, and 20% had fever. Combined gastrointestinal and respiratory symptoms occurred more often in those who shed non-EAds (three of 11) than in matched controls (two of 48, P = 0.04). An adenovirus was detected in approximately 6% of gastroenteritis episodes, and confirmed EAds were present in approximately 2% of episodes of gastroenteritis in children younger than 2 years of age. None of the contacts of patients with non-EAds shed such virus in their stools. None of nine family contacts of those with EAd appeared to shed adenovirus in stool. In contrast, rotavirus spread readily to exposed adults (25% of 65) and children (56% of 62) when a child in similar families had rotavirus infection.

Adenoviridae↗
PubMed1985

Adenoviruses and pediatric gastroenteritis.

Adenoviruses were found in 8.6% of 900 pediatric inpatients with diarrhea who were tested by electron microscopy of a fecal specimen and cell culture inoculation of a throat swab and an anal swab specimen. In 5.1% of these patients, including 13.5% of patients who were four through five months of age, adenovirus particles were visualized in the fecal specimen. Controlled study demonstrated that visualized adenoviruses, especially those that did not grow readily in conventional Hep-2 cell cultures, were significantly associated with diarrhea. About 80% of the visualized adenoviruses from patients with diarrhea or vomiting or both, including 94% of the viruses that grew in the 293 cell line but that did not grow readily in Hep-2 cultures, proved to be enteral adenoviruses--adenoviruses from either group F (type 40) or group G (type 41). Inpatients with gastroenteritis and confirmed enteral adenoviruses ranged in age from one through 16 months, with a median age of seven months. Enteral adenoviruses apparently are endemic in this locale, as one or more of these viruses have been found in every calendar month for nine successive years.

Adenoviridae Infections↗
PubMed1983

Use of electrophoresis of RNA from human rotavirus to establish the identity of strains involved in outbreaks in a tertiary care nursery.

During two nosocomial outbreaks in a tertiary care nursery, 22 of 102 infants had infections due to human rotavirus (HRV). The time sequence and proximity of the infected infants in the nursery rooms had suggested infant-to-infant spread of a single HRV strain in each outbreak. Polyacrylamide gel electrophoresis of virus permitted demonstration of four different HRV electropherotypes (strains) during the first outbreak period and seven during the second. One of the strains was detected during both outbreaks. All strains had fast-migrating RNA segments 10 and 11. Infant-to-infant spread of at least two different viruses apparently occurred in each outbreak period. Thus, electrophoretic analysis showed that infants in a tertiary care center can be infected with at least 10 different HRV strains within two months, that multiple HRV strains can spread independently and in parallel to different infants as part of a "single" outbreak, and that secondary spread of individual strains can be traced with considerable accuracy.

Cross Infection↗
PubMedDate not supplied

Changes in analogical reasoning in adulthood.

This study sought to investigate adult intellectual development through an analysis of a particular type of cognitive ability, verbal analogical reasoning. The performance of 60 individuals between the ages of 20 and 79 was compared on 100 verbal analogies. The subjects consisted of six groups of ten individuals each (five males and five females), matched as a group for education and gender. Solution times and error rates served as the dependent measures. Results showed that there was a significant trend for the older subjects (60- and 70-year-olds) to be slower than the young subjects (20-, 30-, 40-, and 50-year-olds), but not necessarily more error prone. These data suggest that verbal analogical reasoning changes with age. Supplemental data demonstrated a change in other abilities as well (i.e., decline in perceptual-motor speed and spatial skill).

Adult↗