Early optical spectra of nova V1369 Cen show presence of Lithium

We present early high resolution spectroscopic observations of the nova V1369 Cen. We have detected an absorption feature at 6695.6 \AA\, that we have identified as blue--shifted $^7$Li I $\lambda$6708 \AA. The absorption line, moving at -550 km/s, was observed in five high-resolution spectra of the nova obtained at different epochs. On the basis of the intensity of this absorption line we infer that a single nova outburst can inject in the Galaxy $M_{Li} =$ 0.3 - 4.8 $\times 10^{-10}$ M$_{\odot}$. Given the current estimates of Galactic nova rate, this amount is sufficient to explain the puzzling origin of the overabundance of Lithium observed in young star populations.Comment: 6 pages, 5 figures, accepted for publication in ApJLetter

Assessing Physician Response Rate Using a Mixed-Mode Survey

Background. It is important to minimize time and cost of physician surveys while still achieving a reasonable response rate. Mixed-mode survey administration appears to improve response rates and decrease bias. A literature review revealed physician response rates to mixed-mode surveys averaged about 68%. However, no identified studies used the combination of e-mail, fax, and telephone. The purpose of this study was to evaluate physician response rates based on surveys first administered by e-mail, then fax, then telephone. Methods. Surveys initially were administered by e-mail to 149 physicians utilizing SurveyMonkey©. Two follow-up reminder e-mails were sent to non-respondents at two-week intervals. Surveys then were faxed to physicians who had not responded. A follow-up fax was sent to non-respondents one week later. Finally, phone interviews were attempted with physicians who had not responded by e-mail or fax; each physician was called at least twice. Results. Of the 149 eligible physicians, 102 completed the survey for a response rate of 68.5%. Of those who responded, 49 (48%) responded by e-mail, 25 (24.5%) by fax, and 28 (27.5%) by phone. Mode of response did not differ by gender, specialization, or years in practice. In addition, mode of response was not related to the primary study question, physician willingness to use text messaging for immunization reminders. Conclusions. This mix of survey methodologies appeared to be a feasible combination for achieving physician responses and may be more cost effective than other mixed methods

Comparison of work fluctuation relations

We compare two predictions regarding the microscopic fluctuations of a system that is driven away from equilibrium: one due to Crooks [J. Stat. Phys. 90, 1481 (1998)] which has gained recent attention in the context of nonequilibrium work and fluctuation theorems, and an earlier, analogous result obtained by Bochkov and Kuzovlev [Zh. Eksp. Teor. Fiz. 72(1), 238247 (1977)]. Both results quantify irreversible behavior by comparing probabilities of observing particular microscopic trajectories during thermodynamic processes related by time-reversal, and both are expressed in terms of the work performed when driving the system away from equilibrium. By deriving these two predictions within a single, Hamiltonian framework, we clarify the precise relationship between them, and discuss how the different definitions of work used by the two sets of authors gives rise to different physical interpretations. We then obtain a extended fluctuation relation that contains both the Crooks and the Bochkov-Kuzovlev results as special cases.Comment: 14 pages with 1 figure, accepted for publication in the Journal of Statistical Mechanic

Hinode/Extreme-Ultraviolet Imaging Spectrometer Observations of the Temperature Structure of the Quiet Corona

We present a Differential Emission Measure (DEM) analysis of the quiet solar corona on disk using data obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on {\it Hinode}. We show that the expected quiet Sun DEM distribution can be recovered from judiciously selected lines, and that their average intensities can be reproduced to within 30%. We present a subset of these selected lines spanning the temperature range $\log$ T = 5.6 to 6.4 K that can be used to derive the DEM distribution reliably. The subset can be used without the need for extensive measurements and the observed intensities can be reproduced to within the estimated uncertainty in the pre-launch calibration of EIS. Furthermore, using this subset, we also demonstrate that the quiet coronal DEM distribution can be recovered on size scales down to the spatial resolution of the instrument (1$"$ pixels). The subset will therefore be useful for studies of small-scale spatial inhomogeneities in the coronal temperature structure, for example, in addition to studies requiring multiple DEM derivations in space or time. We apply the subset to 45 quiet Sun datasets taken in the period 2007 January to April, and show that although the absolute magnitude of the coronal DEM may scale with the amount of released energy, the shape of the distribution is very similar up to at least $\log$ T $\sim$ 6.2 K in all cases. This result is consistent with the view that the {\it shape} of the quiet Sun DEM is mainly a function of the radiating and conducting properties of the plasma and is fairly insensitive to the location and rate of energy deposition. This {\it universal} DEM may be sensitive to other factors such as loop geometry, flows, and the heating mechanism, but if so they cannot vary significantly from quiet Sun region to region.Comment: Version accepted by ApJ and published in ApJ 705. Abridged abstrac

Effective bioreduction of hexavalent chromium–contaminated water in fixed-film bioreactors

Hexavalent chromium (Cr6+) contamination from a dolomite stone mine in Limpopo Province, South Africa, has resulted in extensive groundwater contamination. In order to circumvent any further negative environmental impact at this site, an effective and sustainable treatment strategy for the removal of up to 6.49 mg/. Cr6+ from the groundwater was developed. Laboratory-scale, continuous up-flow bioreactors were constructed to  evaluate reduction of Cr6+, with a residence time of 24 h, an efficiency  porosity of 44% and a flow rate of 1.5 m./min. Stoichiometrically balancing terminal electron acceptors in the feed water with a selected electron donor, directed reactor balance for complete Cr6+ reduction. The microbial  community shifted in relative dominance during operation to establish an optimal metal-reducing community, including Enterobacter cloacae,  Flavobacterium sp. and Ralstonia sp., which achieved 100% reduction. Evaluation after reactor termination with SEM-EDX and XRD confirmed the establishment of biofilm on the reactor matrix, as well as trivalent  chromium (Cr3+) precipitation within the reactor. Due to gravitational force, high concentrations of Cr3+ were found in the bottom third of the reactor. Based on the results from the laboratory investigation, a 24 000 .  fixed-film pilot bioreactor was designed and constructed at this site. Influent flow rates, electron donor injection and automated sampling were remotely controlled by a programmable logic controller (PLC). Similar to the laboratory column study, steady state conditions could be achieved and successful Cr6+ reduction was evident. This is the first up-scaled, effective demonstration of a biological chromium(VI) bioremediation system in South Africa.Keywords: Bioreduction, fixed-film reactor, hexavalent chromium, microbial diversit

Addressing the clumsiness loophole in a Leggett-Garg test of macrorealism

The rise of quantum information theory has lent new relevance to experimental tests for non-classicality, particularly in controversial cases such as adiabatic quantum computing superconducting circuits. The Leggett-Garg inequality is a "Bell inequality in time" designed to indicate whether a single quantum system behaves in a macrorealistic fashion. Unfortunately, a violation of the inequality can only show that the system is either (i) non-macrorealistic or (ii) macrorealistic but subjected to a measurement technique that happens to disturb the system. The "clumsiness" loophole (ii) provides reliable refuge for the stubborn macrorealist, who can invoke it to brand recent experimental and theoretical work on the Leggett-Garg test inconclusive. Here, we present a revised Leggett-Garg protocol that permits one to conclude that a system is either (i) non-macrorealistic or (ii) macrorealistic but with the property that two seemingly non-invasive measurements can somehow collude and strongly disturb the system. By providing an explicit check of the invasiveness of the measurements, the protocol replaces the clumsiness loophole with a significantly smaller "collusion" loophole.Comment: 7 pages, 3 figure

CCL3 and MMP-9 are induced by TL1A during death receptor 3 (TNFRSF25)-dependent osteoclast function and systemic bone loss

FLC was funded by an Arthritis Research UK PhD studentship (Grant code: 18598) awarded to ASW, ECYW and MDS. JOW was funded by a British Heart Foundation PhD studentship (Reference: FS/11/26/ 28750). ACB's PhD studentship was jointly funded by the School of Medicine and Rheumatology Research Fund (Cardiff University) and LJ's PhD studentship was jointly funded by the School of Medicine and the President's Scholarship Fund (Cardiff University) awarded to ASW. ECYW was additionally funded by MRC Project Grant G0901119.Peer reviewedPublisher PD

Comparison of the Standardized Video Interview and Interview Assessments of Professionalism and Interpersonal Communication Skills in Emergency Medicine

ObjectivesThe Association of American Medical Colleges Standardized Video Interview (SVI) was recently added as a component of emergency medicine (EM) residency applications to provide additional information about interpersonal communication skills (ICS) and knowledge of professionalism (PROF) behaviors. Our objective was to ascertain the correlation between the SVI and residency interviewer assessments of PROF and ICS. Secondary objectives included examination of 1) inter‐ and intrainstitutional assessments of ICS and PROF, 2) correlation of SVI scores with rank order list (ROL) positions, and 3) the potential influence of gender on interview day assessments.MethodsWe conducted an observational study using prospectively collected data from seven EM residency programs during 2017 and 2018 using a standardized instrument. Correlations between interview day PROF/ICS scores and the SVI were tested. A one‐way analysis of variance was used to analyze the association of SVI and ROL position. Gender differences were assessed with independent‐groups t‐tests.ResultsA total of 1,264 interview‐day encounters from 773 unique applicants resulted in 4,854 interviews conducted by 151 interviewers. Both PROF and ICS demonstrated a small positive correlation with the SVI score (r = 0.16 and r = 0.17, respectively). ROL position was associated with SVI score (p < 0.001), with mean SVI scores for top‐, middle‐, and bottom‐third applicants being 20.9, 20.5, and 19.8, respectively. No group differences with gender were identified on assessments of PROF or ICS.ConclusionsInterview assessments of PROF and ICS have a small, positive correlation with SVI scores. These residency selection tools may be measuring related, but not redundant, applicant characteristics. We did not identify gender differences in interview assessments.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150548/1/aet210346_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150548/2/aet210346.pd

Fast approximation of centrality and distances in hyperbolic graphs

We show that the eccentricities (and thus the centrality indices) of all vertices of a $\delta$-hyperbolic graph $G=(V,E)$ can be computed in linear time with an additive one-sided error of at most $c\delta$, i.e., after a linear time preprocessing, for every vertex $v$ of $G$ one can compute in $O(1)$ time an estimate $\hat{e}(v)$ of its eccentricity $ecc_G(v)$ such that $ecc_G(v)\leq \hat{e}(v)\leq ecc_G(v)+ c\delta$ for a small constant $c$. We prove that every $\delta$-hyperbolic graph $G$ has a shortest path tree, constructible in linear time, such that for every vertex $v$ of $G$, $ecc_G(v)\leq ecc_T(v)\leq ecc_G(v)+ c\delta$. These results are based on an interesting monotonicity property of the eccentricity function of hyperbolic graphs: the closer a vertex is to the center of $G$, the smaller its eccentricity is. We also show that the distance matrix of $G$ with an additive one-sided error of at most $c'\delta$ can be computed in $O(|V|^2\log^2|V|)$ time, where $c'< c$ is a small constant. Recent empirical studies show that many real-world graphs (including Internet application networks, web networks, collaboration networks, social networks, biological networks, and others) have small hyperbolicity. So, we analyze the performance of our algorithms for approximating centrality and distance matrix on a number of real-world networks. Our experimental results show that the obtained estimates are even better than the theoretical bounds.Comment: arXiv admin note: text overlap with arXiv:1506.01799 by other author