Chemosensory sensitivity reflects reproductive status in the ant Harpegnathos saltator.

Insects communicate with pheromones using sensitive antennal sensilla. Although trace amounts of pheromones can be detected by many insects, context-dependent increased costs of high sensitivity might lead to plasticity in sensillum responsiveness. We have functionally characterized basiconic sensilla of the ant Harpegnathos saltator for responses to general odors in comparison to cuticular hydrocarbons which can act as fertility signals emitted by the principal reproductive(s) of a colony to inhibit reproduction by worker colony members. When released from inhibition workers may become reproductive gamergates. We observed plasticity in olfactory sensitivity after transition to reproductive status with significant reductions in electrophysiological responses to several long-chained cuticular hydrocarbons. Although gamergates lived on average five times longer than non-reproductive workers, the shift to reproductive status rather than age differences matched the pattern of changes in olfactory sensitivity. Decreasing sensillum responsiveness to cuticular hydrocarbons could potentially reduce mutually inhibitory or self-inhibitory effects on gamergate reproduction

Scientific Literacy in Central Appalachia Through Contextually Relevant Experiences: The “Reading the River” Project

Despite the best intentions of the United States educational system, implementing science reform efforts equitably and consistently throughout the nation is still a long-term goal. The light of scientific literacy has yet to shine brightly in many rural, isolated and economically depressed regions. Using Appalachia as a case in point, this paper provides a synopsis of the challenges of quality rural science education in the United States and the hope of new contextual and culturally relevant pedagogies aimed at engaging science students in inquiry research using their environmental surroundings as cognitive scaffoldings. The program Reading the River is showcased as an exemplary use of the students’ ‘backyard’ to integrate content knowledge in biology, chemistry, geology, physical science, social studies, practical living and mathematics

Functional Connectivity Changes in the Default Mode Network in Moderate-to-Severe Traumatic Brain Injury

Traumatic brain injury (TBI) patients are known to have altered functional connectivity (FC), which has cognitive and behavioral significance and bears clinical implications. Previous literature has discovered a hyperconnectivity response to TBI, most notably in the default mode network (DMN). However, the exact pattern of changes in resting FC during the first year of recovery is unknown. We used resting-state functional magnetic resonance imaging to investigate longitudinal connectivity patterns in the DMN of 28 moderate-to-severe TBI patients as compared to 33 demographically matched healthy controls (HC). FC was assessed at 3, 6, and 12 months post-injury for patients using the posterior cingulate cortex (PCC) as the seed. The first aim of this study was to investigate the resting state FC response in the DMN in the TBI group compared to HC. The second aim involved the evolution of FC responses throughout the first year of recovery from neurotrauma in the patient group. We found in our cross-sectional analysis that patients showed hyperconnectivity responses in the right middle temporal lobe at 3 months post-injury, and hypoconnectivity in the left lateral occipital lobe at 12 months post-injury. However, when we conducted our longitudinal analysis and compared FC across the time points directly with each other, no areas showed a significant change within the TBI group. Our findings suggest a dynamic nature of FC alteration over the first year of recovery after TBI, by showing a hyperconnectivity in the subacute phase and a hypoconnectivity in posterior brain regions as patients reach a more chronic stage. The pattern of FC changes should be further extrapolated into cognitive and behavioral implications, as well as translated into mechanisms of recovery

Comparison of the Inverse Probability of Treatment Weighted (IPTW) Estimator With a Naïve Estimator in the Analysis of Longitudinal Data With Time-Dependent Confounding: A Simulation Study

A simulation study was conducted to compare estimates from a naïve estimator, using standard conditional regression, and an IPTW (Inverse Probability of Treatment Weighted) estimator, to true causal parameters for a given MSM (Marginal Structural Model). The study was extracted from a larger epidemiological study (Longitudinal Study of Effects of Physical Activity and Body Composition on Functional Limitation in the Elderly, by Tager et. al [accepted, Epidemiology, September 2003]), which examined the causal effects of physical activity and body composition on functional limitation. The simulation emulated the larger study in terms of the exposure and outcome variables of interest-- physical activity (LTPA), body composition (LNFAT), and physical limitation (PF), but used one time-dependent confounder (HEALTH) to illustrate the effects of estimating causal effects in the presence of time-dependent confounding. In addition to being a time-dependent confounder (i.e. predictor of exposure and outcome over time), HEALTH was also affected by past treatment. Under these conditions, naïve estimates are known to give biased estimates of the causal effects of interest (Robins, 2000). The true causal parameters for LNFAT (-0.61) and LTPA (-0.70) were obtained by assessing the log-odds of functional limitation for a 1-unit increase in LNFAT and participation in vigorous exercise in an ideal experiment in which the counterfactual outcomes were known for every possible combination of LNFAT and LTPA for each subject. Under conditions of moderate confounding, the IPTW estimates for LNFAT and LTPA were -0.62 and -0.94, respectively, versus the naïve estimates of -0.78 and -0.80. For increased levels of confounding of the LNFAT and LTPA variables, the IPTW estimates were -0.60 and -1.28, respectively, and the naïve estimates were -0.85 and -0.87. The bias of the IPTW estimates, particularly under increased levels of confounding, was explored and linked to violation of particular assumptions regarding the IPTW estimation of causal parameters for the MSM

Effect of HER2 Expression on NUPL2 Protein in Cervical Cancer Cells

Recurring cervical cancer patients frequently present overexpressed Human Epidermal Growth Factor Receptor 2 (HER2) protein, which promotes the growth of the cancer. Some HER2-expressing cells and cervical cancer patients have enhanced gene expression of Nucleoporin-like 2 (NUPL2). As part of the nuclear pore complex, the NUPL2 protein serves to selectively export substances from the nucleus to the cytoplasm. In this experiment, HER2 was expressed in cervical cancer cells to examine its effect on NUPL2 protein expression and localization. Interestingly, there was no difference in NUPL2 protein levels between HER2-expressing and non-expressing cells. Importantly, consistent instances of NUPL2 protein localization specific to the nucleus occurred in a large sampling of HER2-expressing cells. This is significant because it suggests a mechanism as to how HER2 promotes excessive cell growth, via changes in NUPL2 localization, potentially impacting its function and ability to selectively export substances that modulate cell growth

Transient, unsettling and creative space: Experiences of liminality through the accounts of Chinese students on a UK-based MBA

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ The Author(s) 2009.This article explores the experiences of liminality through the accounts of Chinese students on a UK-based MBA programme. The transient nature of the MBA experience, as well as the international status of the Chinese student, is resonant with conceptualizations of liminality as ‘in between’ space. Based on semi-structured interviews with 20 MBA graduates who had subsequently returned to China with their qualification, we explored their perceptions of outcomes from the course and their experiences as international students on a programme imbued with western norms and values. Results support the unsettling yet creative implications of liminality, as well as the fragmented insecure nature of identities, as individuals pass through the MBA ‘rite of passage’ in terms of ‘becoming’ a manager and entering a new phase of career. Accounts suggest the creation of hierarchical structures within liminal space whereby Chinese students, through their positioning at the margin, have uncomfortable yet illuminating encounters with alterity. At the same time, they experience levels of ambiguity and uncertainty in the post-liminal phase of China-located employments, as new western-based managerial identities collide with dominant discourses of Chinese organization

Label-Free Analysis and Sorting of Microalgae and Cyanobacteria in Microdroplets by Intrinsic Chlorophyll Fluorescence for the Identification of Fast Growing Strains.

Microalgae and cyanobacteria are promising organisms for sustainable biofuel production, but several challenges remain to make this economically viable, including identification of optimized strains with high biomass productivity. Here we report on a novel methodology for the label-free screening and sorting of cyanobacteria and microalgae in a microdroplet platform. We show for the first time that chlorophyll fluorescence can be used to measure differences in biomass between populations of picoliter microdroplets containing different species of cyanobacteria, Synechocystis PCC 6803 and Synechococcus PCC 7002, which exhibit different growth dynamics in bulk culture. The potential and robustness of this label-free screening approach is further demonstrated by the screening and sorting of cells of the green alga Chlamydomonas reinhardtii encapsulated in droplets.Author R.J.B. was supported by a Doctoral Training Grant from the Engineering and Physical Sciences Research Council (EPSRC) of the UK (Reference EP/P505445/1), and author J.J.L. was in receipt of a studentship from the Biotechnology and Biological Sciences Research Council (BBSRC) of the U.K. as part of the Cambridge BBSRC-DTP Programme (Reference BB/J014540/1). Authors S.A.-C., C.A., and A.G.S. acknowledge funding from the EC within the FP7 DEMA project, Grant Agreement No. 309086, and authors Z.Y., C.A., and A.G.S. were in receipt of funding from BBSRC sLoLa Award Reference BB/L002957/1.This is the final version of the article. It first appeared from the American Chemical Society via https://doi.org/10.1021/acs.analchem.6b0236

The 14C(n,g) cross section between 10 keV and 1 MeV

The neutron capture cross section of 14C is of relevance for several nucleosynthesis scenarios such as inhomogeneous Big Bang models, neutron induced CNO cycles, and neutrino driven wind models for the r process. The 14C(n,g) reaction is also important for the validation of the Coulomb dissociation method, where the (n,g) cross section can be indirectly obtained via the time-reversed process. So far, the example of 14C is the only case with neutrons where both, direct measurement and indirect Coulomb dissociation, have been applied. Unfortunately, the interpretation is obscured by discrepancies between several experiments and theory. Therefore, we report on new direct measurements of the 14C(n,g) reaction with neutron energies ranging from 20 to 800 keV