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One method burrowing animals are hypothesized to use in adapting to the presumed hypoxic subterranean environment is increasing the oxygen-carrying capacity of blood. A number of recent studies have examined hematologic parameters in laboratory-reared naked mole-rats, but not in animals living under natural atmospheric conditions. To our knowledge, blood chemistry parameters have never been systematically assessed in a fossorial mammal. In this study we examined the blood of wild naked mole-rats in Kenya and Ethiopia to determine whether their blood chemistry differs significantly from naked mole-rats born and living in captivity. We also compared our results to published values for hystricomorphs, other subterranean rodents, and surface-dwelling rodents of similar size.

Naked mole-rats express many unusual traits for such a small rodent. Their morphology, social behaviour, physiology, and ageing have been well studied over the past half-century. Many early findings and speculations about this subterranean species persist in the literature, although some have been repeatedly questioned or refuted. While the popularity of this species as a natural-history curiosity, and oversimplified story-telling in science journalism, might have fuelled the perpetuation of such misconceptions, an accurate understanding of their biology is especially important for this new biomedical model organism. We review 28 of these persistent myths about naked mole-rat sensory abilities, ecophysiology, social behaviour, development and ageing, and where possible we explain how these misunderstandings came about.

The study of Animal Behavior is critically important in understanding our living world and is a major program within the NSF. For students, animal behavior projects offer the opportunity to explore original questions in a scientifically rigorous manner. However, animal behavior projects are under-represented in science fairs and are often discouraged by teachers and judges. We give a sample of the types of questions that students could explore and we suggest appropriate judging criteria.

Human Biology courses are typically offered for non-biology majors who, like students in high school biology courses, have varying degrees of motivation and background. The primary focus is on explaining the biology behind human health and disease, but human ecology, human evolution, and human genetics may also be covered. Hence, Human Biology tends to be a content-rich course, the content overlaps significantly with high school biology courses, and it is usually taught in frontal lecture format. Reading the text may be the only student-directed component of the course. Our goals were to transform our Human Biology course into a more student-directed course with more quantitative problem solving and critical thinking than is typical of science courses for the nonmajor. Frederiksen (1984) points out that development of problem-solving skills may indirectly foster development of pattern recognition and creativity, which are valuable skills for students in any discipline, at any level. We accomplished our goal of fostering more student-directed critical thinking and problem solving by incorporating case study exercises into a discussion section with a social and cooperative learning environment. Social Learning as a Distinct Dimension of Learning Students differ in the sensory modality that stimulates them to learn most efficiently. We often categorize students as visual, auditory, or kinesthetic learners (Fleming & Mills, 1992; Gardner & Hatch, 1989). In lecture courses, auditory learners benefit most by listening to lecture, visual learners benefit most by viewing drawings on the board or screen and by reading the text. Kinesthetic learners learn more easily by handling and manipulating materials in a laboratory setting and may have more difficulty learning in a non-lab course. In addition to these three modalities, we suggest that cooperative learning activities may activate a fourth modality which draws on these same senses, but may offer an entirely different dimension for learning. The sensory modalities involved in small group discussion of problems are mostly visual and auditory, but as in kinesthetic learning, students are active participants rather than passive recipients of information. Just as kinesthetic learning involves feedback to the student in response to what they do to a model or sample, there is repeated feedback between what the student says and what he/she hears from others in a social, cooperative learning setting. This is consistent with Johnson et al.'s (1993) conclusion that cooperative learning requires face-to-face interaction and an interpersonal relationship among the group members. Different centers of the brain are also activated in social situations than in solitary learning settings (Burton et al., 2000; Bannerman et al., 2001; Ferguson et al., 2000). Although lectures may involve large numbers of students in the same place, they are not social settings in that information mostly passes in one direction unless the students are responding to a question. Student interactions in such a setting are limited (and are rarely in the service of learning). In addition, in small social, cooperative learning groups, students appear far more alert and focused on all forms of sensory input. While students may each best learn by visual, auditory, or kinesthetic modes throughout their lives, we suggest that social learning may be especially valuable for middle school, high school, and college students. During these years students are highly focused on social situations. Rather than social interactions becoming a distraction, we have attempted to channel this social energy to the end of working together to solve case study problems. Cooperative learning settings are also exceptionally useful for learning problem-solving skills (Fogarty &: Bellanca, 1992). The increased alertness that corresponds to the social setting of group activities can help students focus attention on integrating various pieces of information necessary to solve a problem. …

Online education is being rapidly embraced as a cash cow for reputable universities. Although there are legitimate advantages to online learning, the data on learning outcomes are scarce. We point out the reasons why high quality, live classes are unlikely to be replaced by online alternatives. However, we do describe the poor teaching practices that can be inexpensively replaced by online courses. We finally point out that best practices and high quality online education are expensive and cannot generate the revenue expected by university administrators.

Every day in the USA, an estimated 50 million complete blood counts (CBC) are ordered clinically. These are ordered as part of annual physical exams, for cancer screening and management, or for diagnosis of infection or allergy. Today, CBCs are automated, although visual examination of stained blood smears is still used for identification of specific disease pathologies. Each automated CBC cytometer is uniquely calibrated, and that machine's reference range for each cell type is reported alongside the patient's cell count. Despite the fact that circulating leukocytes fall and rise predictably with circadian cortisol cycles as shown in figures 1 and 2, CBC results are compared to broad reference ranges that encompasses this temporal variation as well as normal variation among healthy adults.1––4 The crudity of broad reference ranges is well recognised and consequently, inpatient CBC monitoring protocols minimise both sources of variation: blood is drawn at the same time each day and the trend in …

The domestication of the dog has been a ripe area of evolutionary speculation for more than 150 years. A wolf ancestry and probable East Asian origin of domestication are now widely accepted. We offer a new allopatric hypothesis for the domestication of dogs that recognizes the importance of isolation in the speciation of the dog from the wolf. Although sympatric isolation during domestication of many other species would not have been problematic, it has always been difficult to keep dogs from breeding with wild canids. Furthermore, wild canids readily hybridize with one another. This would have made it very difficult for an early domestic dog lineage to diverge from the wolf and to evolve into the morphologically, developmentally, and behaviorally distinct species that we recognize today. Our allopatric model is consistent with two subhypotheses: isolation when tamer scavenger wolves followed humans south and away from hunting populations of wolves or isolation when climate forced humans and tamer scavenger wolves into isolated refugia.

As an index of permeability of the alveolar epithelium, the clearance of an inhaled aerosol of 99mTc-DTPA is increased in several disease states. However, the usefulness of the test to assess the severity of disease is limited because healthy smokers also have abnormally rapid rates of clearance. Because the stability of the 99mTc-DTPA bond might be a contributory factor, we tested the affinity of 99mTc for DTPA in vitro, and in groups of healthy smokers (n = 13) and nonsmokers (n = 7) we measured the clearances of 99mTc-DTPA and 113mIn-DTPA, which have a similar molecular shape and charge. In vitro, sodium hypochlorite or hydrogen peroxide released as much as 98% of free 99mTc from the 99mTc-DTPA complex. When incubated with human neutrophils stimulated with phorbol myristate acetate, between 4 and 7% of free 99mTc-DTPA was released after 30 min, and 12% was released after 60 min. In vivo, the clearances of both 99mTc-DTPA and 113mIn-DTPA in the smokers (n = 13) were faster than in the nonsmokers (n = 7) (p less than 0.05). Within the smokers, the mean 99mTc-DTPA clearance (T1/2 25 +/- 4 min) was faster than the mean 113mIn-DTPA clearance (34 +/- 6 min), (p less than 0.05). For nonsmokers, the difference was smaller (T1/2 99mTc-DTPA, 56 +/- 6; T1/2 113mIn-DTPA, 62 +/- 6) and not significant. During hyperinflation, smokers (n = 8) and nonsmokers (n = 8) both demonstrated an increase in 113mIn-DTPA clearance.(ABSTRACT TRUNCATED AT 250 WORDS)