A Comparison of Approaches and Instruments for Evaluating a Geological Sciences Research Experiences Program

This article describes a study in which changes in knowledge of science and attitudes regarding science among participants in a summer Research Experiences for Undergraduates (REU) program were examined. It was discovered that existing survey instruments could not detect changes in participants' attitudes over the course of the program and also failed to detect differences between geoscience faculty and a group of college students with limited exposure to college level science. In response to this, researchers developed a new survey instrument based on clusters of statements representing a variety of philosophical positions, from which respondents must pick one statement. It was discovered that open-ended questions about the nature of science provide a potentially richer source of information and that a survey instrument designed to probe more subtle aspects of one's beliefs about science can be used to assess adults who have had a variety of different kinds of exposure to science. The pilot survey instrument may also be able, with modifications, to assess attitude and knowledge changes caused by participation in a scientific research experience. Educational levels: Graduate or professional

Crossed reflexes of the human lower limbs: A study using the Hoffman Reflex

Knowledge of the mechanisms involved in the modulation of activity in spinal pathways has increased considerably in recent years. The way in which spinal afferent activity interacts with pattern generator networks and descending control is of particular interest. During locomotion the activity of the two lower limbs is coordinated and it would be anticipated that proprioceptive afferents from one limb might contribute to coordination of the two limbs. The purpose of the present study was to examine possible communication between the limbs. Connections between afferents in the peripheral nerves of one lower limb and the motoneurones of muscles in the opposing limb were investigated. Conditioning electrical stimuli were applied to peripheral nerves in humans at rest and changes in the H- reflexes of muscles in the contralateral limb were monitored. Four pathways have been examined, including pathways between afferents of the tibial nerve and the femoral nerve and the contralateral motoneurone pools of soleus and quadriceps. Crossed inhibitory connections have been identified in three of the four pathways and in two of these the earliest component of the inhibition has been shown to be mediated by group I afferents. A late crossed facilitation has been demonstrated, which could be explained by activity in group II afferents. In relation to the use of the H-reflex as a tool for inferring synaptic inputs to motoneurones, a study was made of the variability of the soleus H-reflex. A decrease in variability with increasing size was identified. The underlying mechanisms which may contribute to the variability changes were examined. A further comparative study was made of the behaviour of the H-reflex of gastrocnemius

Stressing out the poor: chronic physiological stress and the income-achievement gap

This article explores the link between childhood poverty and the negative effects of prolonged exposure to stressful environments.Income distribution

An evaluation of the relationship between self-esteem and pet bonding in children

Obesity has been linked to many physical as well as psychological problems. Many children who are obese suffer from low self-esteem. No studies have been published documenting the effect of owning a dog on the self-esteem of children who are obese. This study used a non-experimental, descriptive, four-group comparison design. One-hundred-twenty participants comprised the four groups: obese children with a dog, obese children without a dog, children of a healthy weight with a dog, and children of a healthy weight without a dog. Participants who were in the 85th percentile or higher for their height and weight were placed in the obese group. All participants completed the Self-Perception Profile for Children (SPPC) and participants who owned a dog that lived in the house at least 50% of the time also completed the Pet Bonding Scale (PBS). The four groups were similar on most demographic characteristics. Obese children had lower scores in the domains of Physical Appearance, Social Competence, and Self-Worth. Participants in the study who owned a dog, both obese and of a healthy weight, were more likely to have lower Physical Appearance and Behavioral Conduct scores. All 60 participants in this study who owned a dog considered the dog to be a member of their family. The findings of this study can be used as the basis for future studies evaluating the relationships between dog ownership of obese children and effects on self-esteem

Stress Axis Hormones Induce Triglyceride Filled Nodule Formation in Vascular Smooth Muscle Cells

Homeostatic stress, such as that which occurs in diabetes, is associated with increased risk for the development of atherosclerosis. Atherosclerotic plaques of the artery wall are associated with both lipid accumulation and fibrous and/or calcified tissue accumulation. Vascular smooth muscle cells (VSMC) are derived from mesenchymal stem cells (MSC) which are capable of differentiating into adipocytes, chondrocytes and osteoblasts. MSC of the bone marrow are pushed toward the chondrogenic and adipogenic phenotypes in the presence of the stress hormones glucocorticoid and adrenocorticotropin (ACTH). This led us to hypothesize that the proliferative VSMC of the Goto-Kakizaki (GK) diabetic rat, when exposed to stress hormones will present an adipocytic and/or chondrogenic-like phenotype. VSMC of the GK rat were cultured using conditions that favor the multi-potential differentiation of MSC and were either left untreated, were treated with ACTH, dexamethasone (DEXA) or both. Cells were stained for lipid using oil-red-o, proteoglycan matrix using alcian blue and cell density using methylene blue. DEXA increased lipid nodule formation above the untreated control but the combined ACTH and DEXA treatment led to a significant increase above DEXA alone (lipid nodule #’s per field, DEXA 2.56 ± 1.63 vs. A+D 6.67 ± 1.68). These data suggest that stress hormones may contribute to VSMC matrix accumulation and lipid production during atherosclerosis development in diabetes

Correction of shallow-water electromagnetic data for noise induced by instrument motion

Author Posting. © The Authors, 2004. This is the author's version of the work. It is posted here by permission of Society of Exploration Geophysicists for personal use, not for redistribution. The definitive version was published in Geophysics 70 (2005): G127–G133, doi:10.1190/1.2080748.An unexpected noise source was found in magnetic and sometimes electric field data recorded on the bottom of lakes in the Archean Slave craton (NW Canada) during warm seasons. The noise is due to instrument motion and in some instances direct induction by wind-driven surface gravity waves when the lakes are not ice covered. The noise can be reduced or eliminated by pre-filtering the data with an adaptive correlation noise cancelling filter using instrument tilt records, prior to estimation of magnetotelluric (MT) response functions. Similar effects are to be expected in other shallow water environments, and the adaptive correlation canceller is a suitable method to pre-process MT data to reduce motional noise in the magnetic field. This underscores the importance of ancillary tilt measurements in shallow water MT surveys. In coastal or lake bottom surveys, special efforts to reduce hydrodynamic effects on the instrument should also be pursued.This project was funded by NSF grant EAR-9725556 and EAR-0087699. P.L. ac- knowledges the Fundacion Andes for a postdoctoral grant

Shared Spaces: The Human and the Animal in the Works of Zora Neale Hurston, Mark Twain, and Jack London

Living in tune with nature means respecting the natural environment and realizing its power and the ways it manifests in daily life. This essay focuses on the ways in which respect for nature is expressed through animal imagery in Zora Neale Hurston's Their Eyes Were Watching God, Mark Twain's "The Stolen White Elephant," Roughing It, and Pudd'nhead Wilson, and Jack London's The Call of the Wild. Each author encouraged readers to seek the benefits of nature in order to become better human beings, forge stronger communities, and develop a more unified nation and world. By learning from the positive example of the animals, we learn how to share our world with them and with each other

Hue Discrimination as Related to Eye Color and Color Education: An Exploratory Study

This exploratory study was undertaken to develop an understanding of the relationship between the physiological aspects of the eye, color education, and the ability of the eye to discriminate color. The objective of the study was to analyze whether a relationship exists among eye color, levels of color education, and major course of study and the ability to discriminate hues. Of the three different eye colors studied in this research, the largest variability in hue discrimination appeared to be students with green eyes. Those students with green eyes in landscape architecture appeared to score better (lower) in the green-yellow area of the spectrum than any of the other majors and eye colors. However, students majoring in interior design with green eyes scored highest of any of the groups, indicating less ability to discriminate among the hues. Possibly, the concentration of work with the green palette by landscape students could account for lower scores than other groups.Home Economic