A comparative integrated geophysical study of Horseshoe Chimney Cave, Colorado Bend State Park, Texas

An integrated geophysical study was performed over a known cave in Colorado Bend State Park (CBSP), Texas, where shallow karst features are common within the Ellenberger Limestone. Geophysical survey such as microgravity, ground penetrating radar (GPR), direct current (DC) resistivity, capacitively coupled (CC) resistivity, induced polarization (IP) and ground conductivity (GC) measurements were performed in an effort to distinguish which geophysical method worked most effectively and efficiently in detecting the presence of subsurface voids, caves and collapsed features. Horseshoe Chimney Cave (HCC), which is part of a larger network of cave systems, provides a good control environment for this research. A 50 x 50 meter grid, with 5 m spaced traverses was positioned around the entrance to HCC. Geophysical techniques listed above were used to collect geophysical data which were processed with the aid of commercial software packages. A traditional cave survey was conducted after geophysical data collection, to avoid any bias in initial data collection. The survey of the cave also provided ground truthing. Results indicate the microgravity followed by CC resistivity techniques worked most efficiently and were most cost effective, while the other methods showed varying levels of effectiveness

Rethinking reflective journals in teacher education

Schooling in the 21st century must embrace the need for learners to be interdisciplinary, navigate change and diversity, to learn as they go, solve problems, collaborate and be flexible and creative. That is, the curriculum must reflect the notion of New Learning (ACDE, 2001). The renewed Bachelor of Education (BEd) program was designed to promote preservice teacher knowledge through provision of opportunities for critical self-reflection in terms of alignment of personal values and beliefs with the concept of New Learning. One of the innovations within the program includes the use of Shared Journals across courses within the program. This paper describes the design of the Bachelor of Education program within one university in Australia and how its philosophical underpinnings fit with the concept of New Learning, and how the reality of implementing and using shared journals within the program to promote preservice teacher critical reflection has challenged staff to rethink their own beliefs about journaling, critical reflection, and their role in the development of critically reflective practitioners

The virtual classroom as a pedagogical space in pre-service teacher education

In preservice teacher education programs, professional practice is typically an integral part, offering a partnership between schools and universities and a space for preservice teachers to experience and experiment with theory into practice. Professional practice sites are generally familiar environments to both direct post Year 12 and mature age preservice teachers. Yet sometimes, professional practice sites, as places where information and communication technologies have changed the way we think and learn, provide little stimulus for reflecting on teaching and learning for the 21st Century. The creation of a virtual classroom in a virtual school was conceived as a means to provide a space for preservice teachers to observe, question, and challenge established schooling practices. In this paper, the virtual classroom is described and analysed

IgE and mast cells in host defense against parasites and venoms.

IgE-dependent mast cell activation is a major effector mechanism underlying the pathology associated with allergic disorders. The most dramatic of these IgE-associated disorders is the fatal anaphylaxis which can occur in some people who have developed IgE antibodies to otherwise innocuous antigens, such as those contained in certain foods and medicines. Why would such a highly "maladaptive" immune response develop in evolution and be retained to the present day? Host defense against parasites has long been considered the only beneficial function that might be conferred by IgE and mast cells. However, recent studies have provided evidence that, in addition to participating in host resistance to certain parasites, mast cells and IgE are critical components of innate (mast cells) and adaptive (mast cells and IgE) immune responses that can enhance host defense against the toxicity of certain arthropod and animal venoms, including enhancing the survival of mice injected with such venoms. Yet, in some people, developing IgE antibodies to insect or snake venoms puts them at risk for having a potentially fatal anaphylactic reaction upon subsequent exposure to such venoms. Delineating the mechanisms underlying beneficial versus detrimental innate and adaptive immune responses associated with mast cell activation and IgE is likely to enhance our ability to identify potential therapeutic targets in such settings, not only for reducing the pathology associated with allergic disorders but perhaps also for enhancing immune protection against pathogens and animal venoms

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log10 increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence