The Dilemma of Choosing Talent: Michael Jordans are Hard to Find

This paper explores the dilemma of choosing talent using NBA data from 1987-2003. We find that there is much uncertainty in selecting talent. If superstars are found they are usually identified early, however, more false positive exist than correct decisions with high draft picks. Our results suggest that the dilemma of choosing talent is not so much a winner’s curse but more like a purchase of a lottery ticket. Most times you lose but if you are going to win you must buy one.

Potential Sinks for Geologic Storage of CO2 Generated in the Carolinas

This document summarizes a scoping study of the current state of knowledge of carbon storage options for our geographic area. The focus is on one aspect of carbon capture and storage—identification of deep saline aquifers in which carbon dioxide (CO2 ) generated in the Carolinas might be stored. The study does not address other aspects of CO2 storage projects, such as capture and compression of the gas, well construction and development, or injection. Transport of CO2 is touched upon in this study but has not been fully addressed. The information contained in this document is primarily from review of published geologic literature and unpublished data. No field data collection has been completed as part of this study. Further work will be necessary to increase confidence in the suitability of the potential CO2 storage sites identified in this report. This study does not address the regulatory, environmental, or public policy issues associated with carbon storage, which are under development at this time.Duke Energy, Progress Energy, Santee Cooper Power, South Carolina Electric and Gas, Electric Power Research Institute (EPRI), Southern States Energy Board (SSEB)Bureau of Economic Geolog

Relationship between Thermodynamic Driving Force and One-Way Fluxes in Reversible Chemical Reactions

Chemical reaction systems operating in nonequilibrium open-system states arise in a great number of contexts, including the study of living organisms, in which chemical reactions, in general, are far from equilibrium. Here we introduce a theorem that relates forward and re-verse fluxes and free energy for any chemical process operating in a steady state. This rela-tionship, which is a generalization of equilibrium conditions to the case of a chemical process occurring in a nonequilibrium steady state, provides a novel equivalent definition for chemical reaction free energy. In addition, it is shown that previously unrelated theories introduced by Ussing and Hodgkin and Huxley for transport of ions across membranes, Hill for catalytic cycle fluxes, and Crooks for entropy production in microscopically reversible systems, are united in a common framework based on this relationship.Comment: 11 page

Near-Infrared Spectroscopy of Carbon-Enhanced Metal-Poor Stars. I. A SOAR/OSIRIS Pilot Study

We report on an abundance analysis for a pilot study of seven Carbon-Enhanced Metal-Poor (CEMP) stars, based on medium-resolution optical and near-infrared spectroscopy. The optical spectra are used to estimate [Fe/H], [C/Fe], [N/Fe], and [Ba/Fe] for our program stars. The near-infrared spectra, obtained during a limited early science run with the new SOAR 4.1m telescope and the Ohio State Infrared Imager and Spectrograph (OSIRIS), are used to obtain estimates of [O/Fe] and 12C/13C. The chemical abundances of CEMP stars are of importance for understanding the origin of CNO in the early Galaxy, as well as for placing constraints on the operation of the astrophysical s-process in very low-metallicity Asymptotic Giant Branch (AGB) stars. This pilot study includes a few stars with previously measured [Fe/H], [C/Fe], [N/Fe],[O/Fe], 12C/13C, and [Ba/Fe], based on high-resolution optical spectra obtained with large-aperture telescopes. Our analysis demonstrates that we are able to achieve reasonably accurate determinations of these quantities for CEMP stars from moderate-resolution optical and near-infrared spectra. This opens the pathway for the study of significantly larger samples of CEMP stars in the near future. Furthermore, the ability to measure [Ba/Fe] for (at least the cooler) CEMP stars should enable one to separate stars that are likely to be associated with s-process enhancements (the CEMP-s stars) from those that do not exhibit neutron-capture enhancements (the CEMP-no stars).Comment: 27 pages, including 5 tables, 6 figures, accepted for publication in The Astronomical Journa

Mitral leaflet anatomy revisited

ObjectiveThe aims of this work were to employ functional imaging capabilities of the Visible Heart laboratory and endoscopic visualization of mitral valves in perfusion-fixed specimens to better characterize variability in mitral valve leaflet anatomy and to provide a method to classify mitral leaflets that varies from the current nomenclature.MethodsWe gathered functional endoscopic video footage (11 isolated reanimated human hearts) and static endoscopic anatomical images (38 perfusion-fixed specimens) of mitral leaflets. Commissure and cleft locations were charted using Carpentier's accepted description.ResultsAll hearts had 2 commissures separating anterior and posterior leaflets. “Standard” clefts separating P1/P2 were found in 66% of hearts (n = 25), and standard clefts separating P2/P3 were present in 71% of hearts (n = 27). “Deviant” clefts occurred in each region of the anterior leaflet (A1, A2, A3), and their relative occurrences were 5%, 8%, and 13% (n = 2, 3, 5), respectively. Deviant clefts were found in posterior leaflets: 13.2% in P1 (n = 5), 32% in P2 (n = 12), and 21% in P3 (n = 8).ConclusionsHumans elicit complex and highly variable mitral valve anatomy. We suggest a complementary, yet simple nomenclature to address variation in mitral valve anatomy by describing clefts as either standard or deviant and locating regions in which they occur (A1 to A3 or P1 to P3)

A Search for Nitrogen-Enhanced Metal-Poor Stars

Theoretical models of very metal-poor intermediate-mass Asymptotic Giant Branch (AGB) stars predict a large overabundance of primary nitrogen. The very metal-poor, carbon-enhanced, s-process-rich stars, which are thought to be the polluted companions of now-extinct AGB stars, provide direct tests of the predictions of these models. Recent studies of the carbon and nitrogen abundances in metal-poor stars have focused on the most carbon-rich stars, leading to a potential selection bias against stars that have been polluted by AGB stars that produced large amounts of nitrogen, and hence have small [C/N] ratios. We call these stars Nitrogen-Enhanced Metal-Poor (NEMP) stars, and define them as having [N/Fe] > +0.5 and [C/N] < -0.5. In this paper, we report on the [C/N] abundances of a sample of 21 carbon-enhanced stars, all but three of which have [C/Fe] < +2.0. If NEMP stars were made as easily as Carbon-Enhanced Metal-Poor (CEMP) stars, then we expected to find between two and seven NEMP stars. Instead, we found no NEMP stars in our sample. Therefore, this observational bias is not an important contributor to the apparent dearth of N-rich stars. Our [C/N] values are in the same range as values reported previously in the literature (-0.5 to +2.0), and all stars are in disagreement with the predicted [C/N] ratios for both low-mass and high-mass AGB stars. We suggest that the decrease in [C/N] from the low-mass AGB models is due to enhanced extra-mixing, while the lack of NEMP stars may be caused by unfavorable mass ratios in binaries or the difficulty of mass transfer in binary systems with large mass ratios.Comment: 14 pages, 7 figures, to be published in Ap

Advanced Glycation End Products Acutely Impair Ca2+ Signaling in Bovine Aortic Endothelial Cells

Post-translational modification of proteins in diabetes, including formation of advanced glycation end products (AGEs) are believed to contribute to vascular dysfunction and disease. Impaired function of the endothelium is an early indicator of vascular dysfunction in diabetes and as many endothelial cell processes are dependent upon intracellular [Ca2+] and Ca2+ signalling, the aim of this study was to examine the acute effects of AGEs on Ca2+ signalling in bovine aortic endothelial cells (BAEC). Ca2+ signalling was studied using the fluorescent indicator dye Fura2-AM. AGEs were generated by incubating bovine serum albumin with 0 - 250 mM glucose or glucose-6-phosphate for 0 to 120 days at 37&#186;C. Under all conditions, the main AGE species generated was carboxymethyl lysine (CML) as assayed using both GC-MS and HPLC. In Ca2+-replete solution, exposure of BAEC to AGEs for 5 min caused an elevation in basal [Ca2+] and attenuated the increase in intracellular [Ca2+] caused by ATP (100 &#181;M). In the absence of extracellular Ca2+, exposure of BAEC to AGEs for 5 min caused an elevation in basal [Ca2+] and attenuated subsequent intracellular Ca2+ release caused by ATP, thapsigargin (0.1 &#181;M) and ionomycin (3 &#181;M), but AGEs did not affect extracellular Ca2+ entry induced by the re-addition of Ca2+ to the bathing solution in the presence of any of these agents. The anti-oxidant α-lipoic acid (2 &#181;M) and NAD(P)H oxidase inhibitors apocynin (500 &#181;M) and diphenyleneiodonium (DPI, 1 &#181;M) abolished these effects of AGEs on BAECs, as did the IP3 receptor antagonist xestospongin C (1 &#181;M). In summary, AGEs caused an acute depletion of Ca2+ from the intracellular store in BAECs, such that the Ca2+ signal stimulated by the subsequent application other agents acting upon this store is reduced. The mechanism may involve generation of ROS from NAD(P)H oxidase and possible activation of the IP3 receptor

Seasonality and outbreak of a predominant Streptococcus pneumoniae serotype 1 clone from The Gambia: expansion of ST217 hypervirulent clonal complex in West Africa.

BACKGROUND: Streptococcus pneumoniae serotype 1 causes > 20% of invasive disease, among all age groups combined, in The Gambia. In contrast, it is rarely detected in carriage studies. This study compares the molecular epidemiology of S. pneumoniae serotype 1 causing invasive disease in The Gambia between 1996 and 2005 to those carried in the nasopharynx between 2004 and 2006. RESULTS: A total of 127 invasive and 36 nasopharyngeal carriage serotype 1 isolates were recovered from individuals of all age groups and were analyzed by serotyping, antibiotic susceptibility testing and MLST. MLST analysis revealed 23 different sequence types (STs), 18 of which were novel. The most prevalent clone among the 163 isolates was ST618 (70.5%), followed by ST3575 (7.4%), ST2084 (2.5%) and ST612 (2.5%). A single ST (ST618), previously shown to belong to the ST217 hypervirulent clonal complex, was frequent among carriage (61.1%) and invasive (72.7%) serotype 1 isolates. ST618 causing both paediatric and adult disease peaked annually in the hot dry season and caused outbreak in 1997 and 2002. CONCLUSION: For over a decade, isolates of ST618 have been the dominant lineage among serotype 1 carriage and disease isolates circulating in the Gambia. This lineage shows similar epidemiological features to those of the meningococcus in the African meningitis belt being able to cause outbreaks of disease

A novel method for poly(A) fractionation reveals a large population of mRNAs with a short poly(A) tail in mammalian cells.

The length of the poly(A) tail of an mRNA plays an important role in translational efficiency, mRNA stability and mRNA degradation. Regulated polyadenylation and deadenylation of specific mRNAs is involved in oogenesis, embryonic development, spermatogenesis, cell cycle progression and synaptic plasticity. Here we report a new technique to analyse the length of poly(A) tails and to separate a mixed population of mRNAs into fractions dependent on the length of their poly(A) tails. The method can be performed on crude lysate or total RNA, is fast, highly reproducible and minor changes in poly(A) tail length distribution are easily detected. We validated the method by analysing mRNAs known to undergo cytoplasmic polyadenylation during Xenopus laevis oocyte maturation. We then separated RNA from NIH3T3 cells into two fractions with short and long poly(A) tails and compared them by microarray analysis. In combination with the validation experiments, the results indicate that approximately 25% of the expressed genes have a poly(A) tail of less than 30 residues in a significant percentage of their transcripts

Evaluating implementation of methicillin-resistant Staphylococcus aureus (MRSA) prevention guidelines in spinal cord injury centers using the PARIHS framework: a mixed methods study

BACKGROUND: To prevent methicillin-resistant Staphylococcus aureus (MRSA) in Spinal Cord Injury and Disorder (SCI/D) Centers, the Guidelines for Implementation of MRSA Prevention Initiative in the Spinal Cord Injury Centers were released in July 2008 in the Veterans Affairs (VA) Health Care System. The purpose of this study was to use the Promoting Action on Research Implementation in Health Systems (PARiHS) framework to evaluate the experiences of implementation of SCI/D MRSA prevention guidelines in VA SCI/D Centers approximately 2-3 years after the guidelines were released. METHODS: Mixed methods were used across two phases in this study. The first phase included an anonymous, web-based cross-sectional survey administered to providers at all 24 VA SCI/D Centers. The second phase included semi-structured telephone interviews with providers at 9 SCI/D Centers. The PARiHS framework was used as the foundation of both the survey questions and semi-structured interview guide. RESULTS: The survey was completed by 295 SCI/D providers (43.8 % response rate) from 22 of the 24 SCI/D Centers (91.7 % participation rate). Respondents included nurses (57.3 %), therapists (24.4 %), physicians (11.1 %), physician assistants (3.4 %), and other health care professionals (3.8 %). Approximately 36 % of the SCI/D providers surveyed had not seen, did not remember seeing, or had never heard of the MRSA SCI/D guidelines, whereas 42.3 % of providers reported that the MRSA SCI/D guidelines were fully implemented in their SCI/D Center. Data revealed numerous barriers and facilitators to guideline implementation. Facilitators included enhanced leadership support and provider education, focused guideline dissemination to reach SCI/D providers, and strong perceived evidence supporting the guidelines. Barriers included lack of awareness of the guidelines among physical therapists and physician assistants and challenges in cohorting/isolating MRSA-positive patients and following contact precautions. CONCLUSIONS: Successful implementation of MRSA infection prevention guidelines in SCI/D settings requires (1) guideline dissemination that reaches the full range of SCI/D providers working in inpatient, outpatient, and other care settings, (2) provider education that is frequent and systematic, (3) strong leadership support, and (4) that barriers unique to the recommendations are addressed. These findings may be used to inform selection of implementation strategies and optimize infection prevention beyond MRSA as well as in other specialty care populations