Resonance Raman spectra of wurtzite and zincblende CdSe nanocrystals

Resonance Raman spectra and absolute differential Raman cross-sections have been measured for CdSe nanocrystals in both the wurtzite and zincblende crystal forms at four excitation wavelengths from 457.9 to 514.5 nm. The frequency and bandshape of the longitudinal optical (LO) phonon fundamental is essentially identical for both crystal forms at each excitation wavelength. The LO phonon overtone to fundamental intensity ratio appears to be slightly higher for the wurtzite form, which may suggest slightly stronger exciton-phonon coupling from the Fröhlich mechanism in the wurtzite form. The LO fundamental Raman cross-sections are very similar for both crystal forms at each excitation wavelength. © 2012 Elsevier B.V. All rights reserved

On what scales can GOSAT flux inversions constrain anomalies in terrestrial ecosystems?

This is the final version. Available on open access from European Geosciences Union via the DOI in this recordData availability. CarbonTracker CT2016 results were provided by NOAA ESRL, Boulder, Colorado, USA, from the website at https://www.esrl.noaa.gov/gmd/ccgg/carbontracker/ (National Oceanic and Atmospheric Administration (NOAA) Earth System Laboratory (ESRL), 2019a). CASA GFED 4.1 and CASA CMS NEE fluxes were also downloaded from the CT2016 website. The GOSAT L4 product and VISIT NEE were downloaded from the GOSAT Data Archive Service (https://data2.gosat.nies.go.jp; NIES, 2019). The Dai Global Palmer Drought Severity Index was downloaded from the Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory (https://doi.org/10.5065/D6QF8R93; Dai, 2017). NASA GOME-2 SIF products were obtained from the Aura Validation Data Center (https://avdc.gsfc.nasa.gov/; Aura Validation Data Center, 2019). FLUXCOM products were obtained from the data portal of the Max Planck Institute for Biochemistry (https://www.bgc-jena.mpg.de/geodb/projects/Home.php.; Max Plank Institue for Biogeochemistry, 2019). MERRA-2 products were downloaded from MDISC (https://gmao.gsfc.nasa.gov/reanalysis/MERRA-2/; Global Modeling and Assimilation Office, 2019), managed by the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC). The GEOS-Chem forward and adjoint models are freely available to the public. Instructions for downloading and running the models can be found at http://wiki.seas.harvard.edu/geos-chem (Atmospheric Chemistry Modeling Group at Harvard University , 2019). ACOS GOSAT lite files were obtained from the CO2 Virtual Science Data Environment (https://co2.jpl.nasa.gov/; Jet Propulsion Laboratory, California Institute of Technology, 2019). The SST anomalies were downloaded from the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory (ESRL) website (https://www.esrl.noaa.gov; National Oceanic and Atmospheric Administration (NOAA) Earth System Laboratory (ESRL), 2019b).Interannual variations in temperature and precipitation impact the carbon balance of terrestrial ecosystems, leaving an imprint in atmospheric CO2. Quantifying the impact of climate anomalies on the net ecosystem exchange (NEE) of terrestrial ecosystems can provide a constraint to evaluate terrestrial biosphere models against and may provide an emergent constraint on the response of terrestrial ecosystems to climate change. We investigate the spatial scales over which interannual variability in NEE can be constrained using atmospheric CO2 observations from the Greenhouse Gases Observing Satellite (GOSAT). NEE anomalies are calculated by performing a series of inversion analyses using the GEOS-Chem adjoint model to assimilate GOSAT observations. Monthly NEE anomalies are compared to "proxies", variables that are associated with anomalies in the terrestrial carbon cycle, and to upscaled NEE estimates from FLUXCOM. Statistically significant correlations (P<0.05) are obtained between posterior NEE anomalies and anomalies in soil temperature and FLUXCOM NEE on continental and larger scales in the tropics, as well as in the northern extratropics on subcontinental scales during the summer (R2≥0.49), suggesting that GOSAT measurements provide a constraint on NEE interannual variability (IAV) on these spatial scales. Furthermore, we show that GOSAT flux inversions are generally better correlated with the environmental proxies and FLUXCOM NEE than NEE anomalies produced by a set of terrestrial biosphere models (TBMs), suggesting that GOSAT flux inversions could be used to evaluate TBM NEE fluxes.Environment and Climate Change CanadaNatural Sciences and Engineering Research Council of CanadaCanadian Space Agenc

2007 Annual progress report synopsis of the Center for Structures of Membrane Proteins

A synopsis of the 2007 annual progress report for the Center for Structures of Membrane Proteins, a specialized center of the Protein Structure Initiative

Evaluation of an interactive, case-based review session in teaching medical microbiology

<p>Abstract</p> <p>Background</p> <p>Oklahoma State University-Center for Health Sciences (OSU-CHS) has replaced its microbiology wet laboratory with a variety of tutorials including a case-based interactive session called Microbial Jeopardy!. The question remains whether the time spent by students and faculty in the interactive case-based tutorial is worthwhile? This study was designed to address this question by analyzing both student performance data and assessing students' perceptions regarding the tutorial.</p> <p>Methods</p> <p>Both quantitative and qualitative data were used in the current study. Part One of the study involved assessing student performance using archival records of seven case-based exam questions used in the 2004, 2005, 2006, and 2007 OSU-CHS Medical Microbiology course. Two sample t-tests for proportions were used to test for significant differences related to tutorial usage. Part Two used both quantitative and qualitative means to assess student's perceptions of the Microbial Jeopardy! session. First, a retrospective survey was administered to students who were enrolled in Medical Microbiology in 2006 or 2007. Second, responses to open-ended items from the 2008 course evaluations were reviewed for comments regarding the Microbial Jeopardy! session.</p> <p>Results</p> <p>Both student performance and student perception data support continued use of the tutorials. Quantitative and qualitative data converge to suggest that students like and learn from the interactive, case-based session.</p> <p>Conclusion</p> <p>The case-based tutorial appears to improve student performance on case-based exam questions. Additionally, students perceived the tutorial as helpful in preparing for exam questions and reviewing the course material. The time commitment for use of the case-based tutorial appears to be justified.</p

Considering the role of cognitive control in expert performance

© 2014, Springer Science+Business Media Dordrecht. Dreyfus and Dreyfus’ (1986) influential phenomenological analysis of skill acquisition proposes that expert performance is guided by non-cognitive responses which are fast, effortless and apparently intuitive in nature. Although this model has been criticised (e.g., by Breivik Journal of Philosophy of Sport, 34, 116–134 2007, Journal of the Philosophy of Sport, 40, 85–106 2013; Eriksen 2010; Montero Inquiry:An interdisciplinary Journal of Philosophy, 53, 105–122 2010; Montero and Evans 2011) for over-emphasising the role that intuition plays in facilitating skilled performance, it does recognise that on occasions (e.g., when performance goes awry for some reason) a form of ‘detached deliberative rationality’ may be used by experts to improve their performance. However, Dreyfus and Dreyfus (1986) see no role for calculative problem solving or deliberation (i.e., drawing on rules or mental representations) when performance is going well. In the current paper, we draw on empirical evidence, insights from athletes, and phenomenological description to argue that ‘continuous improvement’ (i.e., the phenomenon whereby certain skilled performers appear to be capable of increasing their proficiency even though they are already experts; Toner and Moran 2014) among experts is mediated by cognitive (or executive) control in three distinct sporting situations (i.e., in training, during pre-performance routines, and while engaged in on-line skill execution). We conclude by arguing that Sutton et al. Journal of the British Society for Phenomenology, 42, 78–103 (2011) ‘applying intelligence to the reflexes’ (AIR) approach may help to elucidate the process by which expert performers achieve continuous improvement through analytical/mindful behaviour during training and competition

Left-handed color-sextet diquark in Kaon system

We investigate whether a color-sextet scalar diquark (${\bf H}_6$) coupling to the left-handed quarks contributes to the $\Delta S=2$ process. It is found that the box diagrams mediated by $W$ and ${\bf H}_6$ bosons have no contributions to $\Delta S=2$ when the limit of $m_t=0$ is used, and the flavor mixing matrices for diagonalizing quark mass matrices are introduced at the same time. When the heavy top-quark mass effects are taken into account, it is found that in addition to the $W-{\bf H}_6$ box diagrams significantly contributing to $\Delta S=2$, their effects can be as large as those from the ${\bf H}_6-{\bf H}_6$ box diagrams. Using the parameters that are constrained by the $K^0-\bar K^0$ mixing parameter $\Delta M_K$ and the Kaon indirect CP violation $\epsilon_K$, we find that the left-handed color-sextet diquark can lead to the Kaon direct CP violation being $Re(\epsilon'/\epsilon) \sim 0.4 \times 10^{-3}$. In the chosen scheme, although the diquark contribution to $K_L\to \pi^0 \nu \bar\nu$ is small, the branching ratio of $K^+ \to \pi^+ \nu \bar\nu$ can reach the current experimental upper bound.Comment: 22 pages, 6 figure

Divergent roles for Eph and Ephrin in Avian Cranial Neural Crest

<p>Abstract</p> <p>Background</p> <p>As in other vertebrates, avian hindbrain neural crest migrates in streams to specific branchial arches. Signalling from Eph receptors and ephrins has been proposed to provide a molecular mechanism that guides the cells restricting them to streams. In mice and frogs, cranial neural crest express a combination of Eph receptors and ephrins that appear to exclude cells from adjacent tissues by forward and reverse signalling. The objective of this study was to provide comparative data on the distribution and function of Eph receptors and ephrins in avian embryos.</p> <p>Results</p> <p>To distinguish neural crest from bordering ectoderm and head mesenchyme, we have co-labelled embryos for Eph or ephrin RNA and a neural crest marker protein. Throughout their migration avian cranial neural crest cells express EphA3, EphA4, EphA7, EphB1, and EphB3 and move along pathways bordered by non-neural crest cells expressing ephrin-B1. In addition, avian cranial neural crest cells express ephrin-B2 and migrate along pathways bordered by non-neural crest cells expressing EphB2. Thus, the distribution of avian Eph receptors and ephrins differs from those reported in other vertebrates. In stripe assays when explanted cranial neural crest were given the choice between FN or FN plus clustered ephrin-B1 or EphB2 fusion protein, the cells strongly localize to lanes containing only FN. This preference is mitigated in the presence of soluble ephrin-B1 or EphB2 fusion protein.</p> <p>Conclusion</p> <p>These findings show that avian cranial neural crest use Eph and ephrin receptors as other vertebrates in guiding migration. However, the Eph receptors are expressed in different combinations by neural crest destined for each branchial arch and ephrin-B1 and ephrin-B2 appear to have opposite roles to those reported to guide cranial neural crest migration in mice. Unlike many of the signalling, specification, and effector pathways of neural crest, the roles of Eph receptors and ephrins have not been rigorously conserved. This suggests diversification of receptor and ligand expression is less constrained, possibly by promiscuous binding and use of common downstream pathways.</p

FTIR-based spectroscopic analysis in the identification of clinically aggressive prostate cancer

Fourier transform infrared (FTIR) spectroscopy is a vibrational spectroscopic technique that uses infrared radiation to vibrate molecular bonds within the sample that absorbs it. As different samples contain different molecular bonds or different configurations of molecular bonds, FTIR allows us to obtain chemical information on molecules within the sample. Fourier transform infrared microspectroscopy in conjunction with a principal component-discriminant function analysis (PC-DFA) algorithm was applied to the grading of prostate cancer (CaP) tissue specimens. The PC-DFA algorithm is used alongside the established diagnostic measures of Gleason grading and the tumour/node/metastasis system. Principal component-discriminant function analysis improved the sensitivity and specificity of a three-band Gleason score criterion diagnosis previously reported by attaining an overall sensitivity of 92.3% and specificity of 99.4%. For the first time, we present the use of a two-band criterion showing an association of FTIR-based spectral characteristics with clinically aggressive behaviour in CaP manifest as local and/or distal spread. This paper shows the potential for the use of spectroscopic analysis for the evaluation of the biopotential of CaP in an accurate and reproducible manner

Seatbelt use and risk of major injuries sustained by vehicle occupants during motor-vehicle crashes: A systematic review and meta-analysis of cohort studies

BackgroundIn 2004, a World Health Report on road safety called for enforcement of measures such as seatbelt use, effective at minimizing morbidity and mortality caused by road traffic accidents. However, injuries caused by seatbelt use have also been described. Over a decade after publication of the World Health Report on road safety, this study sought to investigate the relationship between seatbelt use and major injuries in belted compared to unbelted passengers.MethodsCohort studies published in English language from 2005 to 2018 were retrieved from seven databases. Critical appraisal of studies was carried out using the Scottish Intercollegiate Guidelines Network (SIGN) checklist. Pooled risk of major injuries was assessed using the random effects meta-analytic model. Heterogeneity was quantified using I-squared and Tau-squared statistics. Funnel plots and Egger's test were used to investigate publication bias. This review is registered in PROSPERO (CRD42015020309).ResultsEleven studies, all carried out in developed countries were included. Overall, the risk of any major injury was significantly lower in belted passengers compared to unbelted passengers (RR 0.47; 95%CI, 0.29 to 0.80; I-2=99.7; P=0.000). When analysed by crash types, belt use significantly reduced the risk of any injury (RR 0.35; 95%CI, 0.24 to 0.52). Seatbelt use reduces the risk of facial injuries (RR=0.56, 95% CI=0.37 to 0.84), abdominal injuries (RR=0.87; 95% CI=0.78 to 0.98) and, spinal injuries (RR=0.56, 95% CI=0.37 to 0.84). However, we found no statistically significant difference in risk of head injuries (RR=0.49; 95% CI=0.22 to 1.08), neck injuries (RR=0.69: 95%CI 0.07 to 6.44), thoracic injuries (RR 0.96, 95%CI, 0.74 to 1.24), upper limb injuries (RR=1.05, 95%CI 0.83 to 1.34) and lower limb injuries (RR=0.77, 95%CI 0.58 to 1.04) between belted and non-belted passengers.ConclusionIn sum, the risk of most major road traffic injuries is lower in seatbelt users. Findings were inconclusive regarding seatbelt use and susceptibility to thoracic, head and neck injuries during road traffic accidents. Awareness should be raised about the dangers of inadequate seatbelt use. Future research should aim to assess the effects of seatbelt use on major injuries by crash type

Dissolved organic carbon transformations and microbial community response to variations in recharge waters in a shallow carbonate aquifer

© 2016, The Author(s). In carbonate aquifers, dissolved organic carbon from the surface drives heterotrophic metabolism, generating CO2 in the subsurface. Although this has been a proposed mechanism for enhanced dissolution at the water table, respiration rates and their controlling factors have not been widely evaluated. This study investigates the composition and concentration of dissolved organic carbon (DOC) reaching the water table from different recharge pathways on a subtropical carbonate island using a combination of DOC concentration measurements, fluorescence and absorption characterisation. In addition, direct measurements of the microbial response to the differing water types were made. Interactions of rainfall with the vegetation, via throughfall and stemflow, increase the concentration of DOC. The highest DOC concentrations are associated with stemflow, overland recharge and dissolution hole waters which interact with bark lignin and exhibit strong terrestrial-derived characteristics. The groundwater samples exhibit the lowest concentrations of DOC and are comprised of refractory humic-like organic matter. The heterotrophic response seems to be controlled by the concentration of DOC in the sample. The terrestrially sourced humic-like matter in the stemflow and dissolution hole samples was highly labile, thus increasing the amount of biologically produced CO2 to drive dissolution. Based on the calculated respiration rates, microbial activity could enhance carbonate dissolution, increasing porosity generation by a maximum of 1%kyr−1 at the top of the freshwater lens