Information literacy in an inquiry course for first-year science undergraduates: a simplified 3C approach

In this article, we describe a simplified approach to teach students to assess information obtained from diverse sources. Three broad categories (credibility, content, and currency; 3C) were used to evaluate information from textbooks, monographs, popular magazines, scholarly journals, and the World Wide Web. This 3C approach used in an inquiry course for freshmen in an undergraduate science program can be readily transferred to other settings.     

Development of a set of PCR-based anchor markers encompassing the tomato genome and evaluation of their usefulness for genetics and breeding experiments

Tomato and potato expressed sequence tag (EST) sequences contained in the solanaceae genomics network (SGN) database were screened for simple sequence repeat (SSR) motifs. A total of 609 SSRs were identified and assayed on Solanum lycopersicum LA925 (formerly Lycopersicon esculentum) and S. pennellii LA716 (formerly L. pennellii). The SSRs that did not amplify, gave multiple band products, or did not exhibit a polymorphism that could be readily detected on standard agarose gels in either of these species were eliminated. A set of 76 SSRs meeting these criteria was then placed on the S. lycopersicum (LA925) x S. pennellii (LA716) high-density map. A set of 76 selected cleaved amplified polymorphism (CAP) markers was also developed and mapped onto the same population. These 152 PCR-based anchor markers are uniformly distributed and encompass 95% of the genome with an average spacing of 10.0 cM. These PCR-based markers were further used to characterize S. pennellii introgression lines (Eshed and Zamir, Genetics 141:1147-1162, 1995) and should prove helpful in utilizing these stocks for high-resolution mapping experiments. The majority of these anchor markers also exhibit polymorphism between S. lycopersicum and two wild species commonly used as parents for mapping experiments, S. pimpinellifolium (formerly L. pimpinellifolium) and S. habrochaites (formerly L. hirsutum), indicating that they will be useful for mapping in other interspecific populations. Sixty of the mapped SSRs plus another 49 microsatellites were tested for polymorphism in seven tomato cultivars, four S. lycopersicum var. cerasiforme accessions and eight accessions of five different wild tomato species. Polymorphism information content values were highest among the wild accessions, with as many as 13 alleles detected per locus over all accessions. Most of the SSRs (90%) had accession-specific alleles, with the most unique alleles and heterozygotes usually found in accessions of self-incompatible species. The markers should be a useful resource for qualitative and quantitative trait mapping, marker-assisted selection, germplasm identification, and genetic diversity studies in tomato. The genetic map and marker information can be found on SGN (http://www.sgn.cornell.edu).     

Cancer genetics evaluation: barriers to and improvements for referral

Despite the availability of cancer susceptibility testing, little information exists regarding physicians' selection and referral of eligible patients. This study provides insight into whom, why, and when physicians refer for cancer genetics evaluation, as well as their comfort level within this role. Eighty-two physicians (51 primary care, 15 gynecology, 11 surgery and 5 oncology) completed a survey (response rate: 34%) regarding cancer genetics referral practices. Of these, 59% reported an awareness of the hospital's cancer genetics program. Program awareness was greater among oncologists, surgeons, and gynecologists than among primary care physicians (p < 0.0001). Patients were referred for enhanced risk assessment (88%), improved medical management (85%), and concern for family members (83%). Patient eligibility was based on family cancer history (96%), patient cancer history (83%), and patient request (73%). Patients were not referred mainly due to patient disinterest (54%) or physician concern about either insurance coverage (44%) or insurance discrimination (31%). Primary care physicians were less comfortable with identifying patients for referral (p < 0.001) and with discussing genetics (p < 0.002) than specialists. The largest barriers to referral were lack of program awareness and limited knowledge regarding patient eligibility, improved insurance coverage, and antidiscrimination legislation. Physician-targeted marketing and education may improve the referral process.     

OECD/PISA研究中科学素养评价的内容

根据OECD／PISA研究报告,简要介绍了OECD／PISA研究中科学素养评价的范围。     

Quantitative genetics: a promising approach for the assessment of genetic variation in endangered species

The measurement of genetic variation is often an important component of endangered species management programs. Each of several tools available to measure genetic diversity has positive and negative attributes. Quantitative genetic techniques have not received much attention in the conservation field, yet they are likely to reveal variation that is most closely associated with components of fitness. In addition, quantitative genetics may not be as logistically difficult for threatened populations as was once thought. Finally, quantitative genetic models provide a better outlook for conservation programs than single-locus models.     

An instrument for assessment of videotapes of general practitioners' performance.

OBJECTIVES--To identify those important characteristics of doctors'' and patients'' behaviour that distinguish between "good" and "bad" consultations when viewed on videotape; to use these characteristics to develop a reliable instrument for assessing general practitioners'' performance in their own consultations. DESIGN--Questionnaires completed by patients, general practitioner trainers, and general practitioner trainees. Reliability of draft instrument tested by general practitioner trainers. SETTING--All vocational training schemes for general practice in the Northern region of England. SUBJECTS--First stage: 76 patients in seven groups, 108 general practice trainers in 12 groups, and 122 general practice trainees in 10 groups. Second stage: 85 general practice trainers in 12 groups. MAIN OUTCOME MEASURES--Trainers'' ratings of importance; alpha coefficients of draft instrument by trainee, group, and consultation. RESULTS--6890 characteristics of good and bad consultations were consolidated into a draft assessment instrument consisting of 46 pairs of definitions separated by six point bipolar scales. Nine statement pairs given low importance ratings by trainers were eliminated, reducing the instrument to 37 statement pairs. To test reliability, general practitioner trainers used the instrument to assess three consultations. With the exception of one group of trainers, all alpha coefficients exceeded the acceptable level of 0.80. CONCLUSION--The instrument produced is reliable for assessing general practitioners'' performance in their own consultations.     

Development of a genetics education workshop curriculum for Native American college and university students.

The long-term goal of Genetic Education for Native Americans (GENA), a project funded by the National Human Genome Research Institute (NHGRI), is to provide a balance of scientific and cultural information about genetics and genetic research to Native Americans and thereby to improve informed decision making. The project provides culturally sensitive education about genetic research to Native American medical students and college and university students. Curriculum development included focus groups, extensive review of available curricula, and collection of information about career opportunities in genetics. Special attention was focused on genetic research to identify key concepts, instructional methods, and issues that are potentially troublesome or sensitive for Native Americans. Content on genetic research and careers in genetics was adapted from a wide variety of sources for use in the curriculum. The resulting GENA curriculum is based on 24 objectives arranged into modules customized for selected science-related conference participants. The curriculum was pretested with Native American students, medical and general university, health care professionals, and basic scientists. Implementation of the curriculum is ongoing. This article describes the development and pretesting of the genetics curriculum for the project with the expectation that the curriculum will be useful for genetics educators working in diverse settings.     

Development and evaluation of a new growth medium for Helicobacter pylori

The present study was aimed at modifying the original formulation of Commercial Eugon agar (CEA) to develop a new H. pylori growth medium. Initial studies were carried out to determine the number of H. pylori colonies recovered on in-house H. pylori agar (IHPA), IHPA without l -cysteine and sodium sulfite (IHPA-NC), IHPA without l -cysteine (IHPA-C), IHPA without sodium sulfite (IHPA-N) and CEA as the control. Significant differences ( P <0.001) in the number of colonies recovered were observed between IHPA-N, IHPA-NC and IHPA-C. Incorporation of sodium sulfite decreased the number of colonies recovered, indicating that sodium sulfite was inhibitory to H. pylori growth. Removal of l -cysteine reduced the number of colonies recovered, suggesting that l -cysteine is necessary for the growth of H. pylori . In the subsequent study, incorporation of K₂HPO₄ further increased the number of colonies recovered compared with IHPA-N ( P <0.001), and 0.25% (w/v) of K₂HPO₄ yielded the highest numbers of colonies ( P ≤0.04). Finally, thirty other H. pylori clinical isolates were evaluated for their growth in the IHPAP-N, a new medium consisting of 1.5% (w/v) pepticase, 0.5% (w/v) peptone, 0.4% (w/v) sodium chloride, 0.03% (w/v) l -cysteine, 0.55% (w/v) dextrose, 0.25% (w/v) K₂HPO₄ and 1.5% (w/v) agar. The number of colonies recovered in IHPAP-N was significantly ( P <0.005) higher than that of CEA. IHPAP-N with 0.25% K₂HPO₄ and without sodium sulfite were adequate solid media for the growth of H. pylori .     

Development and evaluation of a rapid identification test for candida albicans

Summary A new technique for the rapid identification ofC. albicans has been developed and evaluated. This yeast can be identified in one hour by the formation of germ tubes after inoculation in 1/2 ml of human or animal plasma, and commercial plasma substitutes.C. albicans also forms germ tubes within 2 to 4 hours after inoculation in human serum and incubation at 37° C.Filamentation ofC. albicans in these blood derivatives is a reliable method for the identification of this yeast. It is more rapid than the assimilation and fermentation sugar tests and chlamydospore formation.Assimilation and fermentation sugar tests are used to identify those isolates ofCandida that fail to produce filaments in plasma or serum.     

Development and application of a positive-negative selectable marker system for use in reverse genetics in Plasmodium

A limitation of transfection of malaria parasites is the availability of only a low number of positive selectable markers for selection of transformed mutants. This is exacerbated for the rodent parasite Plasmodium berghei as selection of mutants is performed in vivo in laboratory rodents. We here report the development and application of a negative selection system based upon transgenic expression of a bifunctional protein (yFCU) combining yeast cytosine deaminase and uridyl phosphoribosyl transferase (UPRT) activity in P.berghei followed by in vivo selection with the prodrug 5-fluorocytosine (5-FC). The combination of yfcu and a positive selectable marker was used to first achieve positive selection of mutant parasites with a disrupted gene in a conventional manner. Thereafter through negative selection using 5-FC, mutants were selected where the disrupted gene had been restored to its original configuration as a result of the excision of the selectable markers from the genome through homologous recombination. This procedure was carried out for a Plasmodium gene (p48/45) encoding a protein involved in fertilization, the function of which had been previously implied through gene disruption alone. Such reversible recombination can therefore be employed for both the rapid analysis of the phenotype by targeted disruption of a gene and further associate phenotype and function by genotype restoration through the use of a single plasmid and a single positive selectable marker. Furthermore the negative selection system may also be adapted to facilitate other procedures such as 'Hit and Run' and 'vector recycling' which in principle will allow unlimited manipulation of a single parasite clone. This is the first demonstration of the general use of yFCU in combination with a positive selectable marker in reverse genetics approaches and it should be possible to adapt its use to many other biological systems.     

Development of mammalian somatic cell genetics

The history of somatic cell genetics from the late 1950s to the present day is considered. Studies in this field provided for the elucidation of numerous fundamental and applied problems, including spontaneous mutagenesis, gene mapping with somatic cell hybrids, and genetic mechanisms of carcinogenesis (e.g., cell protooncogenes, oncogenes, and tumor suppressor genes were revealed). The knocking-out technique allowed the effects of various genes to be analyzed.     

Development of a risk assessment for BSE in the aquatic environment

Bovine spongiform encephalopathy (BSE) is believed to be transmitted by the ingestion of proteinaceous agents called prions which accumulate in the brain and spinal cord of infected bovines. Concern has been expressed about the risks of transmission of BSE to humans through BSE prions discharged to the aquatic environment from rendering plants, abattoirs and landfills. The disease-related form of the prion protein is relatively resistant to degradation, and infectivity decays rather slowly in the environment. Levels of disinfection used for drinking water treatment would have little effect. This paper presents the assumptions which were used to model the risks from a rendering plant disposing of cull cattle carcasses in the catchment of a chalk aquifer which is used for a drinking water abstraction. The risk assessment approach focused on identifying the hydrogeological and physical barriers which would contribute to preventing BSE infectivity gaining entry to the aquifer. These barriers included inactivation of BSE agent by the rendering process, removal from the effluent by treatment at the plant, filtration and adsorption in the clay and chalk, and dilution in the ground water. The importance in environmental risk assessment of the cow-to-man species barrier is considered. Two key conclusions about the environmental behaviour of the BSE agent are that prion proteins are 'sticky' and bind to particulates, and that the millions of BSE prion molecules comprising a human oral ID₅₀ are subject to some degree of dispersion and hence dilution in the environment. Assuming the rendering plant processes 2000 cull cattle carcasses per week, the risks to drinking water consumers were estimated to be remote. Indeed, even using worst case assumptions an individual would have to consume 2 l d⁻¹ of tap water for 45 million years to have a 50% chance of infection through drinking water drawn from the aquifer.     

Development and evaluation of a real-time quantitative PCR assay for Aspergillus flavus

Aspergillus flavus is a ubiquitous mold and the most common mold contaminating foodstuffs. Many strains of A. flavus produce aflatoxins. In addition it is an allergen and an opportunistic pathogen of animals and plants. A. flavus often is underestimated in traditional culture analyses due to the expertise required and the cost associated with speciating members of the genus Aspergillus. The goal of this study was to develop and validate a primer and probe set for the rapid detection and quantitation of A. flavus in pure culture using real-time quantitative polymerase chain reaction (QPCR) amplification. Unique DNA regions were located in the genome of the target organism by sequence comparison with the GenBank database, and several candidate oligonucleotides were identified from the scientific literature for potential use with the TaqMan QPCR technology. Three primer and probe sets were designed and validated for specificity and sensitivity in laboratory experiments. Initial screening to test for sensitivity was performed with seven A. flavus isolates and selected nontarget fungi. Specificity testing was conducted with the selected primer and probe set, which amplified all nine A. flavus isolates tested, including an aflatoxin producing strain. The primers did not amplify DNA extracted from 39 other fungal species (comprising 16 genera), including 18 other Aspergillus species and six Penicillium species. No amplification of human or bacterial DNA was observed; however cross-reactivity was observed with Aspergillus oryzae. PCR analysis of DNA dilutions and the use of an internal positive control demonstrated that 67% of the fungal DNA samples assayed contained PCR inhibitors. The assay validated for the target organism is capable of producing PCR results in less than 1 h after DNA extraction. The results of this research demonstrate the capabilities of QPCR for the enhanced detection and enumeration of fungi of significance to human health.     

Development of a construct-based risk assessment framework for genetic engineered crops

Experience gained in the risk assessment (RA) of genetically engineered (GE) crops since their first experimental introductions in the early nineties, has increased the level of familiarity with these breeding methodologies and has motivated several agencies and expert groups worldwide to revisit the scientific criteria underlying the RA process. Along these lines, the need to engage in a scientific discussion for the case of GE crops transformed with similar constructs was recently identified in Argentina. In response to this need, the Argentine branch of the International Life Sciences Institute (ILSI Argentina) convened a tripartite working group to discuss a science-based evaluation approach for transformation events developed with genetic constructs which are identical or similar to those used in previously evaluated or approved GE crops. This discussion considered new transformation events within the same or different species and covered both environmental and food safety aspects. A construct similarity concept was defined, considering the biological function of the introduced genes. Factors like environmental and dietary exposure, familiarity with both the crop and the trait as well as the crop biology, were identified as key to inform a construct-based RA process.