The learning process in biofeedback: Is it feed-forward or feedback?

Twenty participants responded to inquiries about strategies used, and thoughts during, each of three electromyograph biofeedback sessions. The purpose of the study was to learn more about what individuals report doing during biofeedback and, specifically, to determine if individuals construct a response using feedback to sense subtle differences in muscle tension (feedback processes), or select a response from an existing repertoire using feedback primarily for confirmation (feed-forward processes). Protocol analyses found considerable support for feed-forward processes and little support for feedback processes. Such results are important because early reliance on feedforward processes may result in limited control and limited transfer.     

Dispersal behaviour of African wild dogs in Kenya

Dispersal behaviour plays a key role in social organisation, demography and population genetics. We describe dispersal behaviour in a population of African wild dogs (Lycaon pictus) in Kenya. Almost all individuals, of both sexes, left their natal packs, with 45 of 46 reproductively active “alpha” individuals acquiring their status through dispersal. Dispersal age, group size and distance did not differ between males and females. However, only females embarked on secondary dispersal, probably reflecting stronger reproductive competition among females than males. When dispersing, GPS-collared wild dogs travelled further than when resident, both in daylight and by night, following routes an order of magnitude longer than the straight-line distance covered. Dispersers experienced a daily mortality risk three times that experienced by adults in resident packs. The detailed movement data provided by GPS-collars helped to reconcile differences between dispersal patterns reported previously from other wild dog populations. However, the dispersal patterns observed at this and other sites contrast with those assumed in published demographic models for this endangered species. Given the central role of dispersal in demography, models of wild dog population dynamics need to be updated to account for improved understanding of dispersal processes.     

A pluripotent human stem-cell clone isolated from the TERA-2 teratocarcinoma line lacks antigens SSEA-3 and SSEA-4 in vitro, but expresses these antigens when grown as a xenograft tumor

Human embryonal carcinoma (EC) cells generally express the cell-surface, stage-specific embryonic antigens 3 and 4 (SSEA-3 and SSEA-4), the epitopes of which are defined by two monoclonal antibodies that recognize different portions of an extended globoseries oligosaccharide. To examine further the relationship between these epitopes and the human EC phenotype, we investigated the properties of two newly isolated clones from the human teratocarcinoma cell line, TERA-2. One clone expresses SSEA-3 and SSEA-4; the other does not. Nevertheless, these clones otherwise resemble one another, and based upon their morphology, their expression of other cell-surface antigens, and their ability to form xenograft tumors containing a variety of cell types, we conclude that both clones are composed of pluripotent human EC cells. When exposed to retinoic acid in vitro, neither clone differentiates as extensively as other clones that we have previously derived from TERA-2. These observations indicate heterogeneity among stem cells derived from a single human teratocarcinoma, and suggest that SSEA-3 and SSEA-4 are not necessarily integral features of the human EC phenotype. On the other hand, EC cells in xenograft tumors derived from the SSEA-3- and SSEA-4-negative clone re-express these epitopes. Further, this re-expression is stable, since EC cell lines that are SSEA-3- and SSEA-4-positive grow out when the tumors are explanted in vitro. We conclude that the expression of these globoseries epitopes can be modulated by environmental influences.     

Sequences from the aspergillopepsin PEP gene of Aspergillus fumigatus: evidence on their use in selective PCR identification of Aspergillus species in infected clinical samples

In immunodeficient patients, Aspergillus species emerge as circumstantial pathogens. Aspergillus fumigatus is a distant first among the pathogenic aspergilli, which cause deep-seated mycoses. Sequences of the pep gene of A. fumigatus as potential PCR primers, which have not been tested before, were used to identify this species and if possible, differentiate it from other, co-identified, clinically important species of the genus. We present results of the three most promising primer pairs, pep-1/pep-22, pep-15/pep-22 and pep-21/pep32. The second pair was of better specificity when tested with DNA extracted from pure cultures of a multitude of aspergilli, whereas the first co-amplified four clinically significant Aspergillus species. The compatibility of the PCR method with the CTAB DNA extraction protocol varied according to the biological fluid tested and the primer pair used. The first two pairs showed moderate adaptability to the different commercial DNA extraction kits, which were tested in whole blood, spiked with Aspergillus fumigatus hyphae and conidia - as were all the biological fluids used. Restriction of the amplification products with MspI produced distinct patterns for different Aspergillus spp. This approach, as a potential diagnostic tool, seems reliable and sensitive due to its flexibility, speed, low cost, ease of application and selectable breadth of detection.     

The learning process in biofeedback: is it feed-forward or feedback?

Twenty participants responded to inquiries about strategies used, and thoughts during, each of three electromyograph biofeedback sessions. The purpose of the study was to learn more about what individuals report doing during biofeedback and, specifically, to determine if individuals construct a response using feedback to sense subtle differences in muscle tension (feedback processes), or select a response from an existing repertoire using feedback primarily for confirmation (feed-forward processes). Protocol analyses found considerable support for feed-forward processes and little support for feedback processes. Such results are important because early reliance on feed-forward processes may result in limited control and limited transfer.     

The equations of population growth

A solution in quadratures is found for a special class of differential equations suggested by studies in the growth of competing populations.     

An international survey of Training Needs and Career Paths of Core Facility Staff

Core facilities (CFs) provide a centralised access to costly equipment, scientific expertise, experimental design, day-to-day technical support and training of users. CFs have a tremendous impact on research outputs, skills and educational agendas, increasing the competencies of staff, researchers and students. However, the rapid development of new technologies and methodologies for the life sciences requires fast adaptation and development of existing core facilities and their technical and scientific staff. Given the scarcity of well-defined CF career paths, CF staff positions are typically filled by people having followed either academic or technical tracks. Each academic institution follows different policies and often fails to adequately recognize the merits of CF personnel and to support their training efficiently. Thus, the Core Technologies for Life Science association (CTLS), through the Training working group, has conducted an anonymous online survey to assess the training needs of CF personnel, as well as to identify common characteristics and challenges in this relatively new and dynamic career type. 275 individuals, including core managers and directors, technicians, technologists and administrators, participated in the survey. The survey was divided into 2 sections; the first, applied to all respondents, and the second, specifically targeted core management issues. Training needs in technological areas, financial and soft skills, management and administrative issues were surveyed as well. The lack of clarity and consistency regarding established career paths for CF professionals was evident from the second part of the survey, highlighting geographical or cultural differences. Gender balance was achieved and the distribution was always taken into account. The results of this survey highlight a need to develop better training resources for CF staff, to improve their recognition within academic institutions, and to establish a recognized career pathway.     

Acute moderate-intensity exercise in middle-aged men has neither an anti- nor proinflammatory effect.

Strenuous exercise induces an initial pro- and subsequent anti-inflammatory response, and it has been suggested that this may be one of the ways that regular exercise reduces chronic inflammation and therefore the risk of cardiovascular disease. However, public health recommendations emphasize moderate-intensity physical activity, and it is important to understand whether moderate-intensity exercise has a similar anti-inflammatory effect. Twelve sedentary male volunteers (age 54 +/- 4 yr) completed two main trials, moderate-intensity exercise and rest (30 min at 50% maximal oxygen uptake vs. sitting, respectively). There were no significant changes in circulating neutrophils, lymphocytes, monocytes, or serum interleukin-6, interleukin-10, and C-reactive protein concentration over the 7 days following exercise. Similarly, lymphocyte adhesion to cultured endothelial cells and heme oxygenase-1 (HO-1) expression in lymphocytes and monocytes were not affected by walking at any time point. These results suggest that the long-term anti-inflammatory and antiatherogenic effects of regular moderate-intensity physical activity must be explained by something other than a profound net anti-inflammatory response to each exercise bout since a single bout of walking did not lead to a change in various markers of inflammation or lymphocyte adherence to cultured endothelial cells.