100 research outputs found
Lysosomes in Biology and Pathology; Volume 6 Frontiers of Biology, 48 Edited by J. T. Dingle, P. J. Jacques and I. H. Shaw Elsevier/North-Holland; Amsterdam, New York, 1979 xxii + 720 pages. $109.75; Dfl 225.00
Secondary School Students' Knowledge and Opinions on Astrobiology Topics and Related Social Issues
Astrobiology is the study of the origin of life on Earth and the distribution of life in the Universe. Its multidisciplinary approach, social and philosophical implications, and appeal within the discipline and beyond make astrobiology a uniquely qualified subject for general science education. In this study, student knowledge and opinions on astrobiology topics were investigated. Eighty-nine students in their last year of compulsory education (age 15) completed a written questionnaire that consisted of 10 open questions on the topic of astrobiology. The results indicate that students have significant difficulties understanding the origin of life on Earth, despite exposure to the topic by way of the assigned textbooks. The students were often unaware of past or present achievements in the search for life within the Solar System and beyond, topics that are far less commonly seen in textbooks. Student questionnaire answers also indicated that students had problems in reasoning and critical thinking when asked for their opinions on issues such as the potential for life beyond Earth, the question of whether UFOs exist, or what our place is in the Universe. Astrobiology might help initiate student awareness as to current thinking on these matters and should be considered for general science educatio
Oxidação lipídica em alimentos e sistemas biológicos: mecanismos gerais e implicações nutricionais e patológicas
The Conceptual Astronomy and Physics Education Research (CAPER) Team
An overview of the research done by the Conceptual Astronomy and Physics Education Research (CAPER) Team is presented.
CAPER conducts rigorous educational research into student understanding and learning difficulties in the areas of astronomy,
astrobiology, physics, planetary science, and earth & space science. The results of this research are used to inform the
development, evaluation and dissemination of innovative instructional interventions and public outreach activities that
promote learners’ intellectual engagement through collaborative learning strategies. Additional targeted areas of effort
include conducting systematic evaluation of educational projects, exhibits and programs, providing professional
development programs for elementary and secondary science teachers, conducting teaching excellence workshops for
university faculty, and partnering with museums and science centers to effectively bring science to the general public. Work
is primarily supported by the US National Science Foundation (NSF), NASA, and the US Department of Education
523 Lipid peroxidation in animal tumours : a disturbance in the control of cell division?
Analysis of the Astronomy Diagnostic Test
Seventy undergraduate class sections were examined from the database of Astronomy Diagnostic Test
(ADT) results of Deming and Hufnagel to determine if course format correlated with ADT normalized
gain scores. Normalized gains were calculated for four different classroom scenarios: lecture, lecture with
discussion, lecture with lab, and lecture with both lab and discussion. Statistical analysis shows that there
are no significant differences in normalized gain among the self- reported classroom formats. Prerequisites
related to mathematics courses did show differences in normalized gain. Of all reported course activities,
only the lecture and the readings for the course correlate significantly with the normalized gain. This
analysis suggests that the ADT may not have enough sensitivity to measure differences in the
effectiveness of different course formats because of the wide range of topics that the ADT addresses with
few questions. Different measures of gain and their biases are discussed. We argue that the use of the
normalized gain is not always warranted because of its strong bias toward high pretest scores
Carbon tetrachloride toxicity as a model for studying free-radical mediated liver injury [and discussion]
A single dose of CCl4 when administered to a rat produces centrilobular necrosis and fatty degeneration of the liver. These hepatotoxic effects of CCl4 are dependent upon its metabolic activation in the liver endoplasmic reticulum to reactive intermediates, including the trichloromethyl free radical. Positive identification of the formation of this free radical in vivo, in isolated liver cells and in microsomal suspensions in vitro has been achieved by e.s.r. spin-trapping techniques. The trichloromethyl radical has been found to be relatively unreactive in comparison with the secondarily derived peroxy radical CCl3O2., although each free radical species contributes significantly to the biological disturbances that occur. Major early perturbations produced to liver endoplasmic reticulum by exposure in vivo or in vitro to CCl4 include covalent binding and lipid peroxidation; studies of these processes occurring during CCl4 intoxication have uncovered a number of concepts of general relevance to free-radical mediated tissue injury. Lipid peroxidation produces a variety of substances that have high biological activities, including effects on cell division; many liver tumours have a much reduced rate of lipid peroxidation compared with normal liver. A discussion of this rather general feature of liver tumours is given in relation to the liver cell division that follows partial hepatectomy.Peer reviewed: YesNRC publication: Ye
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