Plagiarism in science education: Preventing cheating via online auctions

This paper describes a relatively new, but rapidly expanding, cause for concern for academics and administrators, that of students plagiarizing by using online auctions, a practice also known as “contract cheating”. The prevention and detection of such plagiarism in the context of science education presents particular difficulties. The paper suggests possible methods to minimize the number of occurrences, ensuring that as few students cheat as possible, and describes various techniques to aid in the detection of those that do

EMG amplitude in maximal and submaximal exercise is dependent on signal capture rate

This study analysed the effect of different electromyographic (EMG) capture rates during maximal voluntary contraction, submaximal and maximal dynamic cycling activity on EMG amplitude and signal characteristics. Ten healthy subjects participated in this study. Peak power output (PPO) and maximal isometric force output (MVC) were measured, followed by a progressive cycle ride on a cycle ergometer. Electromyographic (EMG) data were simultaneously captured during the MVC and cycling activities at frequencies of 32, 64, 128, 256, 512, 1024 and 1984 Hz. Significant differences in amplitude were found (p < 0.01) between MVC, submaximal (SUB) and maximal cycling activities (PWATT) for all capture rates. Asymptote values for IEMG amplitude occurred at EMG capture rates of 1604 ± 235.6 Hz during MVC, 503.1 ± 236.2 Hz during PWATT and 326.2 ± 105.4 Hz during SUB cycling activity and were significantly different (p < 0.01). No significant differences were found for force/EMG ratios between PWATT and MVC at 1984 Hz capture rates (3.8 ± 1.7 N/V vs 2.5 ± 0.9 N/V) while significant differences occurred at 32 Hz capture rate (6.2 ± 3.8 vs 16.0 ± 8.0; p < 0.01). Low correlations were found between EMG activity captured at 1984 Hz during PWATT and lean thigh volume (r = 0.36) and MVC (r = 0.32). Asymptote values found on this study suggest that data captured below 326 Hz for SUB, 503 Hz for PWATT and 1604 Hz for MVC are not reliable. Therefore apparatus capturing EMG data at low frequencies from these values cannot be used for quantitative data analyses

Satellite-detected fluorescence reveals global physiology of ocean phytoplankton

© 2009 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Biogeosciences 6 (2009): 779-794, doi: 10.5194/bg-6-779-2009Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence. The three dominant factors influencing fluorescence distributions are chlorophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes. After accounting for these three factors, resultant global distributions of quenching-corrected fluorescence quantum yields reveal a striking consistency with anticipated patterns of iron availability. High fluorescence quantum yields are typically found in low iron waters, while low quantum yields dominate regions where other environmental factors are most limiting to phytoplankton growth. Specific properties of photosynthetic membranes are discussed that provide a mechanistic view linking iron stress to satellite-detected fluorescence. Our results present satellite-based fluorescence as a valuable tool for evaluating nutrient stress predictions in ocean ecosystem models and give the first synoptic observational evidence that iron plays an important role in seasonal phytoplankton dynamics of the Indian Ocean. Satellite fluorescence may also provide a path for monitoring climate-phytoplankton physiology interactions and improving descriptions of phytoplankton light use efficiencies in ocean productivity models.This work was supported by grants from the NASA Ocean Biology and Biogeochemistry Program and the NSF Biological Oceanography Program

MyD88-dependent expansion of an immature GR-1+CD11b+ population induces T cell suppression and Th2 polarization in sepsis

Polymicrobial sepsis alters the adaptive immune response and induces T cell suppression and Th2 immune polarization. We identify a GR-1+CD11b+ population whose numbers dramatically increase and remain elevated in the spleen, lymph nodes, and bone marrow during polymicrobial sepsis. Phenotypically, these cells are heterogeneous, immature, predominantly myeloid progenitors that express interleukin 10 and several other cytokines and chemokines. Splenic GR-1+ cells effectively suppress antigen-specific CD8+ T cell interferon (IFN) γ production but only modestly suppress antigen-specific and nonspecific CD4+ T cell proliferation. GR-1+ cell depletion in vivo prevents both the sepsis-induced augmentation of Th2 cell–dependent and depression of Th1 cell–dependent antibody production. Signaling through MyD88, but not Toll-like receptor 4, TIR domain–containing adaptor-inducing IFN-β, or the IFN-α/β receptor, is required for complete GR-1+CD11b+ expansion. GR-1+CD11b+ cells contribute to sepsis-induced T cell suppression and preferential Th2 polarization

Future Directions for Postdoctoral Training in Cancer Prevention: Insights from a Panel of Experts

Cancer prevention postdoctoral fellowships have existed since the 1970s. The National Cancer Institute facilitated a meeting by a panel of experts in April 2013 to consider four important topics for future directions for cancer prevention postdoctoral training programs: 1) future research needs; 2) underrepresented disciplines; 3) curriculum; and 4) career preparation. Panelists proffered several areas needing more research or emphasis, ranging from computational science to culture. Health care providers, along with persons from non-traditional disciplines such as engineers and lawyers, were among disciplines recognized as being underrepresented in training programs. Curriculum suggestions were that fellows receive training in topics such as leadership and human relations, in addition to learning the principles of epidemiology, cancer biological mechanisms, and behavioral science. For career preparation, there was a clear recognition of the diversity of employment options available besides academic positions, and that program leaders should do more to help fellows identify and prepare for different career paths. The major topics and strategies covered at this meeting can help form the basis for cancer prevention training program leaders to consider modifications or new directions, and keep them current with the changing scientific and employment climate for doctoral degree recipients and postdoctoral fellows

Colorectal cancer screening among African American church members: A qualitative and quantitative study of patient-provider communication

BACKGROUND: A healthcare provider's recommendation to undergo screening has been shown to be one of the strongest predictors of completing a colorectal cancer (CRC) screening test. We sought to determine the relationship between the general quality of self-rated patient-provider communication and the completion of CRC screening. METHODS: A formative study using qualitative data from focus groups and quantitative data from a cross-sectional survey of church members about the quality of their communication with their healthcare provider, their CRC risk knowledge, and whether they had completed CRC screening tests. Focus group participants were a convenience sample of African American church members. Participants for the survey were recruited by telephone from membership lists of 12 African American churches located in rural counties of North Carolina to participate in the WATCH (Wellness for African Americans Through Churches) Project. RESULTS: Focus Groups. Six focus groups (n = 45) were conducted prior to the baseline survey. Discussions focused on CRC knowledge, and perceived barriers/motivators to CRC screening. A theme that emerged during each groups' discussion about CRC screening was the quality of the participants' communication with their health care provider. Survey. Among the 397 participants over age 50, 31% reported CRC screening within the recommended guidelines. Participants who self-rated their communication as good were more likely to have been screened (36%) within the recommended guidelines than were participants with poor communication (17%) (OR = 2.8, 95% CI 1.2, 6.4; p = 0.013). Participants who had adequate CRC knowledge completed CRC screening at a higher rate than those with inadequate knowledge (p = 0.011). The percentage of participants with CRC screening in the recommended guidelines, stratified by communication and knowledge group were: 42% for good communication/adequate knowledge; 27% for good communication/inadequate knowledge; 29% for poor communication/adequate knowledge; and 5% for poor communication/inadequate knowledge. CONCLUSIONS: Participants who rated their patient-provider communication as good were more likely to have completed CRC screening tests than those reporting poor communication. Among participants reporting good communication, knowledge about colorectal cancer was also associated with test completion. Interventions to improve patient-provider communication may be important to increase low rates of CRC screening test completion among African Americans

Testing an Emerging Paradigm in Migration Ecology Shows Surprising Differences in Efficiency between Flight Modes

To maximize fitness, flying animals should maximize flight speed while minimizing energetic expenditure. Soaring speeds of large-bodied birds are determined by flight routes and tradeoffs between minimizing time and energetic costs. Large raptors migrating in eastern North America predominantly glide between thermals that provide lift or soar along slopes or ridgelines using orographic lift (slope soaring). It is usually assumed that slope soaring is faster than thermal gliding because forward progress is constant compared to interrupted progress when birds pause to regain altitude in thermals. We tested this slope-soaring hypothesis using high-frequency GPS-GSM telemetry devices to track golden eagles during northbound migration. In contrast to expectations, flight speed was slower when slope soaring and eagles also were diverted from their migratory path, incurring possible energetic costs and reducing speed of progress towards a migratory endpoint. When gliding between thermals, eagles stayed on track and fast gliding speeds compensated for lack of progress during thermal soaring. When thermals were not available, eagles minimized migration time, not energy, by choosing energetically expensive slope soaring instead of waiting for thermals to develop. Sites suited to slope soaring include ridges preferred for wind-energy generation, thus avian risk of collision with wind turbines is associated with evolutionary trade-offs required to maximize fitness of time-minimizing migratory raptors

Roles of Coactivators in Hypoxic Induction of the Erythropoietin Gene

Hypoxia-inducible expression of the erythropoietin (EPO) gene is mediated principally by hypoxia-inducible factor 2alpha (HIF-2alpha) in Hep3B cells under physiologic conditions. How/whether p300/CBP and the members of p160 coactivator family potentiate hypoxic induction of endogenous EPO and other HIF-2alpha and hypoxia-inducible factor 1alpha (HIF-1alpha) target genes remains unclear.We demonstrate, using chromatin immunoprecipitation (ChIP) analysis, that the histone acetyl transferase (HAT) coactivators p300, SRC-1 and SRC-3 are recruited to the 3' enhancer of the EPO gene upon hypoxic stimulation, and that each associates with the enhancer in a periodic fashion. Hypoxia induced acetylation of the EPO gene 5' promoter at histone 4 and lysine 23 of histone 3. Knocking down SRC-3, but not SRC-1 or SRC-2, using short interfering RNAs (siRNAs), reduced EPO transcriptional activity. Knocking down p300 resulted in dramatic down-regulation of hypoxic stimulation of EPO gene transcription, negated recruitment of RNA polymerase II to the gene's promoter, and eliminated hypoxia-stimulated acetylation at the promoter and recruitments of SRC-1 and SRC-3 to the enhancer. The inhibitory effects of knocking down p300 and the chromatin remodeling coactivator, Brm/Brg-1, on EPO transcription were additive, suggesting that p300 and Brm/Brg-1 act independently. p300 was also required for hypoxia induced transcription of the HIF-1alpha target gene, VEGF, but was dispensable for induction of two other HIF-1alpha target genes, PGK and LDHA. Knocking down CBP, a homolog of p300, augmented hypoxic induction of VEGF, LDHA and PGK. Different HIF target genes also exhibited different requirements for members of the p160 coactivator family.p300 plays a central coactivator role in hypoxic induction of EPO. The coactivators exhibit different specificities for different HIF target genes and each can behave differently in transcriptional regulation of different target genes mediated by the same transcription factor