Models of Classroom Assessment for Course-Based Research Experiences.

Course-based research pedagogy involves positioning students as contributors to authentic research projects as part of an engaging educational experience that promotes their learning and persistence in science. To develop a model for assessing and grading students engaged in this type of learning experience, the assessment aims and practices of a community of experienced course-based research instructors were collected and analyzed. This approach defines four aims of course-based research assessment - 1) Assessing Laboratory Work and Scientific Thinking; 2) Evaluating Mastery of Concepts, Quantitative Thinking and Skills; 3) Appraising Forms of Scientific Communication; and 4) Metacognition of Learning - along with a set of practices for each aim.

Genetic and morphological evidence for substantial hidden biodiversity in a freshwater crayfish species complex.

North America is a center of biodiversity for freshwater crayfish, with >300 described species, mostly in the family Cambaridae. However, the phylogenetic and phylogeographic relationships among these taxa are poorly understood, despite their ubiquitous occurrence in North American freshwater habitats. Here, we target the geographically widespread Orconectesvirilis and its sister taxa for genetic and morphological investigation.

Quantitative evaluation of Enterocytozoon bieneusi infection in simian immunodeficiency virus-infected rhesus monkeys.

The association of the microsporidia Enterocytozoon bieneusi with chronic diarrhea and wasting in individuals with acquired immunodeficiency syndrome (AIDS) has been demonstrated. The disease caused by E. bieneusi has been linked to decreased levels of circulating CD4+ T lymphocytes.

Enterocytozoon bieneusi among children with diarrhea attending Mulago Hospital in Uganda.

The prevalence of Enterocytozoon bieneusi in the general population is unknown. Using genetic tools, we investigated its prevalence and contribution to diarrhea and malnutrition in hospitalized children in Uganda. A cross-sectional, case-control study involving diarrheic children who were matched for age and sex (3:1) with control children.

Genetic analysis of a Cryptosporidium parvum human genotype 1 isolate passaged through different host species.

Cryptosporidium parvum TU502, a genotype 1 isolate of human origin, was passaged through three different mammalian hosts, including humans, pigs, and calves. It was confirmed to be genotype 1 by PCR-restriction fragment length polymorphism analysis of the Cryptosporidium oocyst wall protein gene, direct sequencing of PCR fragments of the small subunit rRNA and beta-tubulin genes, and microsatellite analysis. This isolate was shown to be genetically stable when passaged through the three mammalian species, with no evidence of the emergence of new subpopulations as observed by a genotype-specific PCR assay.

Prevalence of Enterocytozoon bieneusi in swine: an 18-month survey at a slaughterhouse in Massachusetts.

Slaughterhouse pig samples were analyzed by PCR for Enterocytozoon bieneusi infection. Thirty-two percent were found to be positive, with rates being higher over the summer months. Three isolates from pigs were identical in their ribosomal internal transcribed spacer sequence to human E.

Animal propagation and genomic survey of a genotype 1 isolate of Cryptosporidium parvum.

Human cryptosporidiosis is attributed to two major Cryptosporidium parvum genotypes of which type 1 appears to be the predominant. Most laboratory investigations however are performed using genotype 2 isolates, the only type which readily infects laboratory animals. So far type 1 has only been identified in humans and primates.

Transmission and serial propagation of Enterocytozoon bieneusi from humans and Rhesus macaques in gnotobiotic piglets.

For over a decade Enterocytozoon bieneusi infections in people with AIDS have been linked with chronic diarrhea and wasting. The slow scientific progress in treating these infections is attributed to the inability of investigators to cultivate the parasite, which has also precluded evaluation of effective therapies. We report here successful serial transmissions of E.

A novel satellite/microsatellite combination in the genome of the marine shrimp, Penaeus vannamei.

In our studies of repeated sequences in the genome of the marine shrimp, Penaeus vannamei (Pv), we have discovered a novel combination of sequence elements. We inserted restriction fragments of genomic DNA into a plasmid vector and screened for recombinant plasmids containing repeated sequences. Ten of the resulting isolates contained representatives of the same repeated element, a satellite sequence present in one or more blocks of tandemly repeated units.

Improved hepatocyte culture system for studying the regulation of glycogen synthase and the effects of diabetes.

When 3-4-week-old rats (young rats) are used as a source of hepatocytes, primary culture cells express the adult, differentiated, liver-specific isoform of glycogen synthase. Synthase enzyme protein levels are relatively stable over a 3 day culture period in young but not in adult (> 150 g rat) hepatocyte cultures. Corresponding synthase enzyme activity and mRNA levels decrease over time in culture in adult but not in young hepatocyte cultures.

Transformation of adult ventricular myocytes with the temperature sensitive A58 (tsA58) mutant of the SV40 large T antigen.

Freshly isolated ventricular myocytes have been used extensively as an adult cardiac model system. Due to their inability to undergo cytokinesis in vitro and their dedifferentiated properties in long-term culture, they can not be used for extended studies. Recent reports tell of the establishment of fetal and neonatal cardiac cell lines and the development of adult cardiomyocytes from transgenic animals.

Ultraviolet light-induced plasmid-chromosome recombination in Escherichia coli: the role of recB and recF.

Bacterial host cells of different rec genotypes were used to investigate genetic requirements of ultraviolet light (UV)-induced homologous plasmid-chromosome recombination. Plasmid DNAs which contained a wt or mutant lacY gene were irradiated with UV prior to transformation into Escherichia coli host strains which contained the complementary lacY allele. Surviving transformants were screened to determine the directions of UV-induced recombinational exchange between the bacterial and plasmid lacY genes, by assaying lactose utilization.