cssi/SciSciGPT-SciSciNet huggingface dataset:
Cervical length at 16-22 weeks' gestation and risk for preterm delivery.

Abstract Objective: To determine whether cervical length, as measured by transvaginal sonogram in asymptomatic gravidas at 16–22 weeks, is associated with risk of spontaneous preterm delivery. Methods: In a prospective observational study in an unselected urban tertiary care population, cervical length was measured by transvaginal ultrasound during routine anatomic surveys in 760 gravidas at 16 0/7 to 22 6/7 weeks. The predictor variable was cervical length and the outcome variable was gestational age at delivery. Care providers were not masked to the results. Spontaneous preterm delivery was analyzed as before 37, 35, and 32 weeks. Shortened cervical length was defined by the tenth, fifth, and two and a half percentiles for our population. Yates-corrected χ2 was used to evaluate the significance on univariate analysis of the relative risk (RR) and 95% confidence intervals (CI). Multiple logistic regression analysis was used to control for background variables in evaluating the probability of preterm delivery at less than 35 weeks. Sensitivity, specificity, positive and negative predictive values also were calculated. Results: Cervical lengths were normally distributed (mean 38.5 ± 8.0 mm at 19.9 ± 1.5 weeks) independent of gestational age at measurement, and the tenth, fifth, and two and a half percentiles were 30, 27, and 22 mm, respectively. Eighty-five women delivered before 37 weeks, 51 before 35 weeks, and 27 before 32 weeks. Relative risks (95% CI) for spontaneous preterm delivery before 37 weeks were 3.8 (2.6, 5.6), 5.4 (3.3, 9.0), and 6.3 (3.0, 13.0) for the tenth, fifth, and two and a half percentiles, respectively; RRs for before 35 weeks were 4.5 (2.9, 6.9), 7.5 (4.5, 12.5), and 7.8 (3.6, 16.7); and for before 32 weeks were 5.2 (3.3, 8.3), 9.7 (5.8, 16.1), and 8.4 (3.6, 19.9), respectively. Multiple logistic regression analysis confirmed that cervical length was a significant predictor of preterm birth before 35 weeks, and that paras had a 43% greater risk compared with nulliparas. Sensitivity ranged from 13–44%, specificity 90–99%, positive predictive value 15–47%, and negative predictive value 80–98%. Conclusion: Transvaginal measurement of cervical length during routine ultrasound at 16–22 weeks’ gestation in asymptomatic gravidas might help identify women at risk for spontaneous preterm delivery.
Microwave radio emissions of negative cloud-to-ground lightning flashes

Abstract We report preliminary results of a new observational study of microwave-frequency electromagnetic radiation that is emitted by lightning discharge processes. Radiation was observed with a ceramic patch antenna and a digital radio receiver tuned to a center frequency of 1.63 GHz and a bandwidth of 2 MHz. The recorded radiation waveforms are compared with data collected by the Oklahoma Lightning Mapping Array (OKLMA) lightning mapping system and the co-located Earth Networks Total Lightning Network (ENTLN) broadband electric field antenna. Microwave radiation was observed to occur during preliminary breakdown, negative stepped leader breakdown, negative dart leader breakdown, and return strokes. Characteristic radiation signatures were observed, including trains of individually resolvable impulses during breakdown and brief but intense trains of noise-like bursts during return strokes.
Critical care cardiovascular nurse expert and novice diagnostic cue utilization.

Aim. Critical care cardiovascular (CCCV) nursing diagnostic expertise was the focus of this research. The purpose of the study was to compare diagnostic cue utilization between expert and novice CCCV nurses. Background. Knowledge related to objective measures of clinical nursing diagnostic expertise would enhance effective and efficient recognition, utilization, and reward of clinical expertise. Methods. Five CCCV written simulations served as instruments in the study. Diagnostic content areas included left ventricular dysfunction, cardiac tamponade, sepsis, right ventricular failure, and hypovolemia related to internal abdominal haemorrhage. The sample was composed of 23 expert and 23 novice nurses. After reading each simulation, subjects were asked to verbally recall the simulation, give an impression of the predominant problem or diagnosis, and give a diagnostic explanation. Verbal recalls were audio-taped for protocol analysis. Diagnostic accuracy and cue utilization were determined through comparisons of subjects' recalled diagnoses and cues with results from an expert panel review consensus. The major variable was the mean recalled proportion of highly relevant cues to total cues (HRC/TC) on accurately diagnosed simulations. Chi-square analysis revealed that diagnostic accuracy was greater with experts than with novices. Differences between and among simulations, expertise, accuracy and the mean proportion of highly relevant cues to total cues were examined with a 4 × 2 × 2 factorial analysis of variance. Results. When considering all accurately diagnosed simulations, experts had a higher HRC/TC than novices. The major limitations were the use of low fidelity written simulations and virgin verbal protocol methods. Conclusion. The findings generally support the idea that the development of diagnostic expertise is associated with the ability to focus on highly relevant cues.
International reserves: Adjustment dynamics

Abstract This paper presents evidence suggesting that central banks have a target level of international reserves, and that the dynamics of adjustment is rapid. The estimated speed of adjustment is faster than suggested by previous estimates.
Offers of hepatitis C care do not lead to treatment.

Since 2002, clinicians have been encouraged to offer chronic hepatitis C virus (HCV) treatment to patients with injection drug use histories. We conducted 69 baseline and 35 follow-up interviews between September 2002 and November 2004 with HCV patients who were treatment-naive and receiving regular medical care at an HIV or methadone clinic in New York City at baseline. Of the 31 patients reinterviewed, 20 (65%) were offered treatment but only 2 (7%) were treated. Reasons for failure to be reinterviewed were loss to follow-up at the original site of care (30), death (6), and refusal to be reinterviewed (2). Whereas offers of HCV treatment may be increasing, there is a need to improve continuity of care, patient–provider communication, and patient education regarding HCV treatment options for treatment rates to improve.
Auxin Activity of Isatin and Oxindole-3-Acetic Acid.

Most workers have found that oxindoles are inactive as auxins or as auxin antagonists. For example, Thimann (44) working with straight growth of Avena coleoptile cylinders and Pisum stem sections, and with growth curvature of slit Pisum stem sectionis, found the following 6 compounds to be without effect at concentrations up to 30 mg/liter, both in the absence and presence of IAA at concentrations up to 5 mg/liter: oxindole-3-acetonitrile, oxindole-3pyruvic oxime, oxindolene-3-acetonitrile, oxindolene3-pyruvic acid, 3-dehydrodioxindole and 3-methyl dioxindole. In this paper, we would like to report on the considerable growth activity elicited by isatin (indole-2, 3-dione) and oxindole-3-acetic acid (fig 1) compounds which, on the basis of past literature, would have been expected to be inactive.
Medicare and Medicaid spending variations are strongly linked within hospital regions but not at overall state level.

Proposals to move toward reducing geographic differentials in health care spending have focused on patterns of spending in Medicare. We show in this article that when considering each state as a whole, there is almost no relationship between the level of spending for Medicare beneficiaries and that for other populations. In sharp contrast to these state-level results, there is a strong relationship between Medicare and Medicaid spending in comparing Hospital Referral Regions within each state. We suggest that the strong intrastate regional correlations demonstrate the importance of the supply of hospital beds, specialists, and other health care resources as determinants of use and spending. In contrast, the lack of correlation at the state level suggests that other factors, such as state-level poverty rates, influence use and spending at the state level, and that these other factors influence Medicare and non-Medicare use and spending differently. These findings demonstrate that it is important to broaden...
Addition rules and the contribution of δ' precipitates to strengthening of aged AlLiCu alloys

Abstract The room temperature yield strength of two alloys, Al-2.30 wt% Li-2.85 Cu-0.12 Zr (the 2–3 alloy) and Al-2.90 Li-0.99 Cu-0.12Zr (the 3-1 alloy), was investigated as a function of aging time at 160 and 190°C. Reversion experiments were used to separate the contributions of the δ' and T1, precipitates to the overall strength of the aged samples. The reversion heat treatments nearly completely dissolved the δ' precipitates, leaving the dispersion of T1 precipitates essentially undisturbed and enabling its contribution, ΔτT1, to be measured experimentally. Assuming linear additivity of the precipitation hardening contribution, Δτp, and all the others (due to grain size strengthening, solid solution strengthening, etc.), the δ' contribution, Δτδ', was estimated using a generalized addition rule of the type Δτpq = Δτδ'q + ΔτT1q, where q is a constant (the shear stresses, Δτ, were obtained from the measured yield stresses using data on the textures of the alloys). These values of Δτδ', were then analysed according to a recent version of the theory of order strengthening which requires that the trailing dislocation be pulled through the sheared ordered precipitates immediately on encountering them. It was found that for the underaged alloys only q = 1.4 yielded values of the APB energy on {111}, γapb, that were identical for both the 3-1 and 2–3 alloys (0.150 J/m2). Using this value of γabp, the theoretically predicted values of Δτδ' at peak strength and the δ' particle size at peak strength were in very good agreement with the experimentally measured values, and the predicted spacings of the dislocation pairs were in excellent agreement with those measured. It is demonstrated that the value of q is not merely an empirical constant required to bring theory and experiment in agreement, but is justified by the results of computer simulation experiments on strengthening by point obstacles of two distinct strengths. The possible role of other strengthening mechanisms is discussed.
Identifying Native Vegetation for Reducing Exotic Species during the Restoration of Desert Ecosystems

There is currently much interest in restoration ecology in identifying native vegetation that can decrease the invasibility by exotic species of environments undergoing restoration. However, uncertainty remains about restoration's ability to limit exotic species, particularly in deserts where facilitative interactions between plants are prevalent. Using candidate native species for restoration in the Mojave Desert of the southwestern U.S.A., we experimentally assembled a range of plant communities from early successional forbs to late-successional shrubs and assessed which vegetation types reduced the establishment of the priority invasive annuals Bromus rubens (red brome) and Schismus spp. (Mediterranean grass) in control and N-enriched soils. Compared to early successional grass and shrub and late-successional shrub communities, an early forb community best resisted invasion, reducing exotic species biomass by 88% (N added) and 97% (no N added) relative to controls (no native plants). In native species monocultures, Sphaeralcea ambigua (desert globemallow), an early successional forb, was the least invasible, reducing exotic biomass by 91%. However, the least-invaded vegetation types did not reduce soil N or P relative to other vegetation types nor was native plant cover linked to invasibility, suggesting that other traits influenced native-exotic species interactions. This study provides experimental field evidence that native vegetation types exist that may reduce exotic grass establishment in the Mojave Desert, and that these candidates for restoration are not necessarily late-successional communities. More generally, results indicate the importance of careful native species selection when exotic species invasions must be constrained for restoration to be successful.
The effect of 1-ethyl-3(3-dimethylaminopropyl)carbodiimide on calcium binding and associated changes in chloroplast structure and chlorophyll a fluorescence in spinach chloroplasts.

Abstract 1. 1. Chemical modification of carboxyl groups on the chloroplast membrane with a water-soluble carbodiimide plus a nucleophile caused inhibition of Ca2+ binding. 2. 2. Both binding sites were affected and showed a decrease in the number of binding sites and an increase in the dissociation constant. 3. 3. Cation-induced changes in chlorophyll a fluorescence and structural changes (ΔA540) were inhibited at the same carbodiimide concentrations as Ca2+ binding, emphasizing the relationship between these processes. 4. 4. Chloroplasts that were illuminated with high intensity light for short time periods showed a decrease in the carbodiimide-mediated inhibition of Ca2+ binding.
Ocular Abnormalities in the Median Cleft Face Syndrome

An 8-month-old infant boy with median facial cleft syndrome had eyelid coloboma, symblepharon, and a cytic mass in the left upper eyelid. The mass proved to be an ectatic cornea containing a large cystic lens. Maldevelopment of the entire anterior segment of the eye was also present, although the posterior globe was well formed. We postulate that an area of localized abnormal mesodermal differentiation and fusion at the 17- to 20-mm stage of development served as a common mechanism for all the defects noted.
Color Switchable Goggle Lens Based on Electrochromic Polymer Devices

We have developed a set of new electrochromic devices (ECDs) for special application goggles, whose color can be switched between transparent and a specific color mode, i.e. blue (B). This paper will discuss the design, film deposition, device assembly and characterizations of the color switchable lens. The ECD is composed of a layer of thin film conducting polymer poly (3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDOT-Me2), a layer of thin film inorganic oxide V2O5-TiO2, and a layer of ionic conductive electrolyte. The thin films are electrochemically deposited on ITO coated flexible plastic substrate. The whole device is packaged with an UV cured flexible film sealant. The goggle lens exhibit tuneable shade in visible light wave length (380-800nm), with a maximum contrast ratio at 580nm. Meanwhile, other unique properties include fast switching speed, low driving voltage, memory function (no power needed after switching, bistable), great durability, high flexibility, light weight, and inexpensiveness.
Forced Flame Response of a Lean Premixed Multi-Nozzle Can Combustor

An experimental investigation was conducted to determine the air-forced flame response of a five-nozzle, 250 kW, lean premixed gas turbine can combustor. Operating conditions were varied over a range of inlet temperatures, inlet velocities, and equivalence ratios, while the forcing frequency was varied from 100 to 450 Hz with constant normalized velocity fluctuations of approximately 5%. The response of the flame’s rate of heat release to inlet velocity fluctuations is expressed in terms of the phase and gain of a flame transfer function. In addition, chemiluminescence imaging is used to characterize the time-averaged and phase-averaged spatial distribution of the flame’s heat release. The resulting flame transfer functions and chemiluminescence flame images are compared to each other to determine the effects of varying the operating conditions. In addition, they are compared to data obtained from a single-nozzle combustor with the same injector. The forced response of the multi-nozzle flame demonstrates a similar pattern to those obtained in a single-nozzle combustor with the same injector. An exception occurs at high frequency where the multi-nozzle flame responds to a greater degree than the single-nozzle flame. At low frequency the multi-nozzle flame dampens the perturbations while the single-nozzle flame amplifies them. A number of minima and maxima occur at certain frequencies which correspond to the interference of two mechanisms. The frequency of these minima is nearly the same for the single- and multi-nozzle cases. When plotted with respect to Strouhal number instead of frequency there is a degree of collapse that occurs around the first observed minima.© 2011 ASME
Blade Dynamic Stall Vortex Kinematics for a Horizontal Axis Wind Turbine in Yawed Conditions

Horizontal axis wind turbines routinely suffer significant time varying aerodynamic loads that adversely impact structures, mechanical components, and power production. As lighter and more flexible wind turbines are designed to reduce overall cost of energy, greater accuracy and reliability will become even more crucial in future aerodynamics models. However to render calculations tractable, current modeling approaches admit various approximations that can degrade model predictive accuracy. To help understand the impact of these modeling approximations and improve future models, the current effort seeks to document and comprehend the vortex kinematics for three-dimensional, unsteady, vortex dominated flows occurring on horizontal axis wind turbine blades during non-zero yaw conditions. To experimentally characterize these flows, the National Renewable Energy Laboratory Unsteady Aerodynamics Experiment turbine was erected in the NASA Ames 80 ft×120 ft wind tunnel. Then, under strictly-controlled inflow conditions, turbine blade surface pressures and local inflow velocities were acquired at multiple radial locations. Surface pressure histories and normal force records were used to characterize dynamic stall vortex kinematics and normal forces. Stall vortices occupied approximately two-thirds of the aerodynamically active blade span and persisted for nearly one-fourth of the blade rotation cycle. Stall vortex convection varied dramatically along the blade radius, yielding pronounced dynamic stall vortex deformation. Analysis of these data revealed systematic alterations to vortex kinematics due to changes in test section speed, yaw error, and blade span location.
In vitro toxicity of n‐hexane and 2,5‐hexanedione using isolated perfused rabbit heart

In vitro toxicity of n‐hexane and 2,5‐hexanedione using isolated perfused rabbit heart is reported. The hearts were perfused using Langendorf's procedure and modified Anderson's coronary perfusion apparatus. The force of cardiac contraction was significantly reduced following 1 h perfusion with 9.6 mg/l concentration of n‐hexane and with 0.35% v/v concentration of 2,5‐hexanedione.
The effects of logging and disease on American chestnut

Abstract Disturbance histories drive spatiotemporal patterns of species distributions, and multiple disturbances can have complex effects on these patterns of distribution. The introduction of the chestnut blight (Cryphonectria parasitica (Murril.) Barr.) to the eastern United States in the early 1900s coincided with an increase in logging, thus presenting an ideal situation for studying the effect of two disturbance events, logging and disease. The purpose of this study was to compare chestnut (Castanea dentata) abundance and the prevalence of chestnut blight among (1) sites that were and were not logged for chestnuts during the blight pandemic and (2) sites that varied in time since the last logging event. Current chestnut abundance and chestnut blight prevalence were assessed in areas where chestnut was known to occur before the blight. Elevation, soil pH, slope, aspect, age of canopy trees, and presence or absence of chestnut stumps indicating selective logging of chestnuts were recorded at each site. Chestnuts were more abundant on sites that had not been selectively logged for pre-blight chestnuts. Chestnut presence was more likely at high elevations (857 m ± 33 m). Chestnut abundance was greater at high elevations (>1000 m) and acidic soils (pH 4–5). Chestnut blight prevalence was not correlated with any measured environmental variable. Rather, 15.1% of all chestnut stems were infected with blight regardless of chestnut density. Thus, higher chestnut abundance is not due to lower mortality from the chestnut blight, although the temporal dynamics of blight infection and stem recovery were not within the scope of this study. This research shows that local rates of chestnut population decline differ between locations with different chestnut logging histories. Chestnut site preferences are better understood within the context of history, and thus teasing apart the effects of disease, logging, and environment will result in more successful chestnut restoration efforts.
The optics of colloidal silver: something old and something new

Abstract The remarkable optical properties of metallic silver give rise not only to the brilliant colors exhibited by colloidal silver but also to a variety of other phenomena. Recently noted phenomena such as absorption and scattering effects, luminescence, photophoresis, and surface-enhanced Raman scattering are reviewed. New results are presented illustrating color effects, photoelectron emission, light emission from tunnel junctions and evanescent fields at the surface of an optical fiber.
Semantic priming without association: A meta-analytic review

A meta-analysis of 26 studies indicated that automatic semantic priming can occur without association. Priming did not vary substantially with differences in variables that affect automatic versus strategic processing, such as time spent processing the prime and target, relationship proportion, and task (except that average effects were smaller in the naming task). Although category coordinates were investigated in the majority of studies, synonyms, antonyms, and script relations also demonstrated priming; functional relations showed greater priming, and essential and perceptual relations showed less. The average effect size for semantic priming was smaller than that for associative priming, suggesting that there is an “associative boost” from adding an associative relationship to a semantic one. The implications of these findings for the modularity thesis and for models of semantic priming are discussed.
Isolation and characterization of reptilian insulin: Partial amino acid sequence of rattlesnake (Crotalus atrox) insulin☆

Insulin was isolated from the pancreas of two species of rattlesnake, Crotalus atrox and C. adamanteus. The procedure involved acid-ethanol extraction, gel filtration and DEAE-Sephadex chromatography. The insulin content of the pancreata was high, approximately 20 mg/100 g pancreas. Both insulins were identical in amino acid composition but this composition differed considerably from that of bovine insulin. Insulin from C. atrox assayed at 21.6 IU/mg in the mouse convulsion assay. The amino acid sequence of C. atrox insulin was determined and found to have some uncommon substitutions in the B chain.
Renal MR angiography: A comprehensive approach

Renal artery MR angiography has now emerged as a safe, accurate approach to renal arteriography. A comprehensive examination, including both three-dimensional (3D) dynamic gadolinium-enhanced and 3D phase contrast MRA techniques, allows evaluation of both the aorta-renal and splanchnic arterial anatomy as well as the hemodynamic significance of any stenoses identified. The 3D gadolinium-enhanced MRA technique produces a contrast arteriogram but without risks of iodinated contrast or ionizing radiation. The 3D phase contrast technique is a flow-based technique, which may show dephasing in the presence of hemodynamically significant stenoses. A comprehensive examination should also include T1- and T2-weighted imaging for the assessment of potential neoplastic masses and the ubiquitous renal cysts. Through trial and error over the course of over a thousand examinations, this comprehensive approach to the MR evaluation of renal vascular pathology has emerged.
Enhancing Prostate Cancer Care Through the Multidisciplinary Clinic Approach: A 15-Year Experience

The multidisciplinary clinic approach to prostate cancer may enhance outcomes and reduce “treatment regret” through a coordinated presentation of all therapeutic options. This model serves as an interdisciplinary educational tool for patients and their families, and supports clinical trial participation.
Cardiotrophin-1 in Heart Failure

Cardiotrophin-1 (CT-1) is a 201 amino acid1 member of the interleukin (IL)-6 cytokine superfamily, which includes leukemia inhibitory factor (LIF), ciliary neurotrophic factor, IL-11, and oncostatin M.2 Cardiotrophin-1 was discovered by Pennica et al2 via expression cloning of mouse embryoid bodies, using a cardiac myocyte hypertrophy screen to identify positive clones. CT-1 has hypertrophic and cardioprotective properties and acts through LIF receptor β/glycoprotein 130 (gp130)-coupled signaling pathways. The LIF receptor binds CT-1, and then gp130 associates with the ligand-receptor complex and transduces the proximal signal. CT-1 intracellular signaling pathways include extracellular signal regulated kinases (ERK), mitogen activated protein (MAP) kinases, the janus kinase (JAK)/signal transducers and activators of transcription (STAT) system, and PI3-kinase/Akt. Downstream mediators of CT-1’s cellular effects include multiple ERK-coupled transcription factors, STAT-3, nuclear factor-κB, and heat shock proteins 56, 70, and 90. Cardiac CT-1 expression is increased by hypoxia, where it protects cardiac myocytes from ischemic and reperfusion injury and apoptosis. See p 1442 As described shortly after its discovery, CT-1 promotes cardiac myocyte hypertrophy by directing sarcomere assembly in series.3 At the ventricular structural level, in-series sarcomeric assembly leads to “eccentric” hypertrophy and chamber dilatation. Thus, increased myocardial expression of CT-1 immediately became a candidate for the molecular basis of pathological hypertrophy and remodeling in dilated cardiomyopathy phenotypes. The cardiac myocyte protective effects were also appreciated early in the investigation of CT-1’s biological properties.4 Mice with genetic ablation of gp130 have hypoplastic hearts,5 which suggests a role for CT-1 or other IL-6–type cytokines in normal cardiac development. However, mice with ventricular myocyte-restricted knockout of gp130 using a ventricular myosin light chain 2 promoter that drives a Cre/lox recombination/knockout system from early in development have no cardiac abnormalities at birth,6 indicating that the …
Influence of physical factors on the developmental stages of Hippelates collusor in relation to the activities of its natural parasites.

Investigations into the effects of temperature, moisture, pH, soil type, and food supply on developing stages of Hippelates collusor (Townsend) demonstrated varied vulnerability among different life stages. Egg hatching was dependent on temperature and amount of moisture, an “aestivating” egg appearing under certain conditions. Larval development was proportional to the amount of dry organic matter present in the form of plant roots when adequate moisture was supplied. Younger growing plants were more suitable than older plants for development. First-instar larvae remained active in distilled water in excess of 25 clays at 75°F. Excessive moisture was more severe on pupae than eggs and larvae, but pupae tolerated low temperatures longer. Both weakly acid and weakly basic environments were suitable to optimum development. Heavy soils were less suitable than lighter soils. Older larvae were more resistant to low temperatures than younger larvae, but the latter did not tolerate moisture as well. Possible explanations for the differences in adult oven-dry body weights from separate treatments are discussed. The relation of the effects of physical factors on the size and abundance of H. collusor is discussed, with the ovipositional behavior of its larval and pupal parasites. The importance to biological control of a thorough understanding of the physical factors already dynamically involved in natural control is stressed.
Dynamic Data Driven Simulations in Stochastic Environments

To improve the predictions in dynamic data driven simulations (DDDAS) for subsurface problems, we propose the permeability update based on observed measurements. Based on measurement errors and a priori information about the permeability field, such as covariance of permeability field and its values at the measurement locations, the permeability field is sampled. This sampling problem is highly nonlinear and Markov chain Monte Carlo (MCMC) method is used. We show that using the sampled realizations of the permeability field, the predictions can be significantly improved and the uncertainties can be assessed for this highly nonlinear problem.
Human ATP:Cob(I)alamin adenosyltransferase and its interaction with methionine synthase reductase.

Abstract The final step in the conversion of vitamin B12 into coenzyme B12 (adenosylcobalamin, AdoCbl) is catalyzed by ATP:cob(I)alamin adenosyltransferase (ATR). Prior studies identified the human ATR and showed that defects in its encoding gene underlie cblB methylmalonic aciduria. Here two common polymorphic variants of the ATR that are found in normal individuals are expressed in Escherichia coli, purified, and partially characterized. The specific activities of ATR variants 239K and 239M were 220 and 190 nmol min–1 mg–1, and their Km values were 6.3 and 6.9 μm for ATP and 1.2 and 1.6 μm for cob(I)alamin, respectively. These values are similar to those obtained for previously studied bacterial ATRs indicating that both human variants have sufficient activity to mediate AdoCbl synthesis in vivo. Investigations also showed that purified recombinant human methionine synthase reductase (MSR) in combination with purified ATR can convert cob(II)alamin to AdoCbl in vitro. In this system, MSR reduced cob(II)alamin to cob(I)alamin that was adenosylated to AdoCbl by ATR. The optimal stoichiometry for this reaction was ∼4 MSR/ATR and results indicated that MSR and ATR physically interacted in such a way that the highly reactive reaction intermediate [cob(I)alamin] was sequestered. The finding that MSR reduced cob(II)alamin to cob(I)alamin for AdoCbl synthesis (in conjunction with the prior finding that MSR reduced cob(II)alamin for the activation of methionine synthase) indicates a dual physiological role for MSR.
Symbolic dynamics and periodic orbits of the Lorenz attractor

The butterfly-like Lorenz attractor is one of the best known images of chaos. The computations in this paper exploit symbolic dynamics and other basic notions of hyperbolicity theory to take apart the Lorenz attractor using periodic orbits. We compute all 111011 periodic orbits corresponding to symbol sequences of length 20 or less, periodic orbits whose symbol sequences have hundreds of symbols, the Cantor leaves of the Lorenz attractor, and periodic orbits close to the saddle at the origin. We derive a method for computing periodic orbits as close as machine precision allows to a given point on the Lorenz attractor. This method gives an algorithmic realization of a basic hypothesis of hyperbolicity theory—namely, the density of periodic orbits in hyperbolic invariant sets. All periodic orbits are computed with 14 accurate digits.
The Accuracy, Consistency, and Speed of an Electron-Positron Equation of State Based on Table Interpolation of the Helmholtz Free Energy

An electron-positron equation of state based on table interpolation of the Helmholtz free energy is developed and analyzed. The interpolation scheme guarantees perfect thermodynamic consistency, independent of the interpolating function. The choice of a biquintic Hermite polynomial as the interpolating function results in accurately reproducing the underlying Helmholtz free energy data in the table, and yields derivatives of the pressure, specific entropy, and specific internal energy which are smooth and continuous. The execution speed—evaluated across several different machine architectures, compiler options, and modes of operation—suggests that the Helmholtz equation of state routine is faster than any of the five equation of state routines surveyed by Timmes & Arnett. When an optimal balance of accuracy, thermodynamic consistency, and speed is desirable then the tabular Helmholtz equation of state is an excellent choice, particularly for multidimensional models of stellar phenomena.
Context-aware statistical debugging: from bug predictors to faulty control flow paths

Effective bug localization is important for realizing automated debugging. One attractive approach is to apply statistical techniques on a collection of evaluation profiles of program properties to help localize bugs. Previous research has proposed various specialized techniques to isolate certain program predicates as bug predictors. However, because many bugs may not be directly associated with these predicates, these techniques are often ineffective in localizing bugs. Relevant control flow paths that may contain bug locations are more informative than stand-alone predicates for discovering and understanding bugs. In this paper, we propose an approach to automatically generate such faulty control flow paths that link many bug predictors together for revealing bugs. Our approach combines feature selection (to accurately select failure-related predicates as bug predictors), clustering (to group correlated predicates), and control flow graph traversal in a novel way to help generate the paths. We have evaluated our approach on code including the Siemens test suite and rhythmbox (a large music management application for GNOME). Our experiments show that the faulty control flow paths are accurate, useful for localizing many bugs, and helped to discover previously unknown errors in rhythmbox
The influence of air pollution on Thoroughbred race performance

This study examined the changing levels of air pollution at major racetracks in the United States over the past 35 years of Grade I Stakes Thoroughbred racing (n = 675) to evaluate the impact on race performance. Information on winning race times, race speed, temperature, track conditions, ozone and particulate matter was analysed using multiple regression and ANOVA. The 8, 9 and 12 furlong races showed slight improvement in winning times over the 35-year time span. Although there was no significant difference in mean race speed in terms of particulate matter (F4,112 = 0.514, α < 0.05), the few races run under ‘hazardous’ ozone levels, based on the Pollutants Standards Index, were markedly slower (F4,251 = 12.365, α < 0.05). A multiple regression analysis of six additional pollutants in the Californian races revealed no significant effects beyond a slight improvement in the 7 furlong races, with decreased nitrogen dioxide levels. Of the nine racetracks with 9 furlong races, winning times in Pimlico and Belmont were approximately 4 s slower than average. Belmont also had the greatest percentage of races with hazardous ozone conditions. Other correlations between year, pollutants and improvements in race time were of small magnitude and may be an artefact of the sample size rather than of true predictive value. While racing under high levels of certain pollutants appears detrimental to equine athletes, very few races are run under these conditions and other factors such as breeding, training and individual variation may play a more significant role than this study could document with respect to pollution.
Queries and Concept Learning

We consider the problem of using queries to learn an unknown concept. Several types of queries are described and studied: membership, equivalence, subset, superset, disjointness, and exhaustiveness queries. Examples are given of efficient learning methods using various subsets of these queries for formal domains, including the regular languages, restricted classes of context-free languages, the pattern languages, and restricted types of prepositional formulas. Some general lower bound techniques are given. Equivalence queries are compared with Valiant's criterion of probably approximately correct identification under random sampling.
Subtle differences in receptor binding specificity and gene sequences of the 2009 pandemic H1N1 influenza virus

A recent phylogenetic inference indicated that the 2009 pandemic H1N1 strains circulating from March 2009 to September 2009 could be divided into two closely related but distinct clusters. Cluster one contained most strains from Mexico, Texas, and California, and cluster two had most strains from New York, both of which were reported to co-circulate in all continents. The same study further revealed nine nucleotide changes in six gene segments of the new virus specific for the two clusters. In the current study, the informational spectrum method (ISM), a bioinformatics technique, was employed to study the receptor binding patterns of the two clusters. It discovered that while both groups shared the same primary human binding affinity, their secondary binding preferences were different. Cluster one favored swine binding as its secondary binding pattern, whereas cluster two mostly exhibited the binding specificity of A/South Carolina/1/18 (H1N1) (one of the 1918 flu pandemic strains) as its secondary binding pattern. Besides all the nine nucleotide changes found in the previous study, Random Forests were applied to uncover several new nucleotide polymorphisms in 10 genes of the strains between the two clusters, and several amino acid changes in the HA protein that might be accountable for the discrepancy of the secondary receptor binding patterns of the two clusters. Finally, entropy analysis was conducted to present a global view of gene sequence variations between the two clusters, which illustrated that cluster one had much higher genetic divergence than cluster two. Furthermore, it suggested a significant overall correspondence between the nucleotide positions of high importance in differentiating the two clusters and nucleotide positions of high entropy in cluster one.
“His Mind Aglow”: The Biological Undercurrent in Fitzgerald's Gatsby and Other Works

Readers familiar with F. Scott Fitzgerald's early work might recall that in those years just before the Scopes trial he wrote of Victorians who "shuddered when they found what Mr. Darwin was about"; or that he joined in the fashionable comic attacks on people who could not accept their "most animal existence," describing one such character as "a hairless ape with two dozen tricks. "* But few would guess the extent to which his interest in evolutionary biology shaped his work. He was particularly concerned with three interrelated biological problems: (1) the question of eugenics as a possible solution to civilization's many ills, (2) the linked principles of accident and heredity (as he understood these through the lens of Ernst Haeckel's biogenetic law), and (3) the revolutionary theory of sexual selection that Darwin had presented in The Descent of Man and Selection in delation to Sex (1871). As I hope to show in the following pages, his concern with these issues underlies such well known features in the Fitzgerald landscape as his insecurity in the " social hierarchy" (his sense of its "terrifying fluidity"), his emphasis on the element of time, his interest in "the musk of money," his interest in Spengler and the naturalists, and his negative portraiture of male
The association between preoperative patient characteristics and both clinical and economic outcomes after abdominal aortic surgery

Objective: To evaluate the association between patient characteristics and both clinical and economic outcomes in patients having abdominal aortic surgery in Maryland between 1994 and 1996. Design: Retrospective study using an administrative data set. Setting: All Maryland hospitals that performed abdominal aortic surgery from 1994 through 1996 (n = 46). Participants: All patients who had abdominal aortic surgery in Maryland from 1994 through 1996 (n = 2,987). Interventions: None. Measurements and Main Results: The authors obtained discharge abstracts from the Maryland Health Services Cost Review Commission for patients with a primary procedure code for abdominal aortic surgery. Primary outcome variables were in-hospital mortality, hospital length of stay, and intensive care unit (ICU) days. The authors evaluated the following groups of independent variables: demographic characteristics, severity of illness, comorbid disease, and preoperative admission days. In multivariate analysis, independent predictors of in-hospital mortality were age 61 to 70 years (odds ratio [or], 3.1; confidence interval [ci], 1.4 to 6.9), age 71 to 84 years (OR, 7.2; CI, 3.7 to 14.1), age 85 years or older (OR, 9.3; CI, 3.9 to 21.9), ruptured aneurysm (OR, 5.3; CI, 3.5 to 8.2), urgent operation (OR, 2.3; CI, 1.1 to 5.2), emergent operation (OR, 3.0; Cl, 1.9 to 4.7), mild liver disease (OR, 4.6; CI, 2.0 to 10.9), and chronic renal disease (OR, 6.9; CI, 3.9 to 12.1). Hospital admission 1 to 2 days preoperatively was not associated with a difference in in-hospital mortality but was associated with a 31% increase in hospital days (CI, 23% to 40%) and a 38% increase in ICU days (Cl, 19% to 60%). Conclusion: In patients having aortic surgery, several patient characteristics such as mild liver disease and chronic renal failure, were associated with increased in-hospital mortality and length of stay. The practice of admitting patients to the hospital 1 to 2 days before surgery should be reevaluated because this was not associated with reduced in-hospital mortality but was associated with increased hospital and ICU stay.
Plasmonic nanotweezers: Strong influence of adhesion layer and nanostructure orientation on trapping performance

Using Au bowtie nanoantennas arrays (BNAs), we demonstrate that the performance and capability of plasmonic nanotweezers is strongly influenced by both the material comprising the thin adhesion layer used to fix Au to a glass substrate and the nanostructure orientation with respect to incident illumination. We find that a Ti adhesion layer provides up to 30% larger trap stiffness and efficiency compared to a Cr layer of equal thickness. Orientation causes the BNAs to operate as either (1) a 2D optical trap capable of efficient trapping and manipulation of particles as small as 300 nm in diameter, or (2) a quasi-3D trap, with the additional capacity for size-dependent particle sorting utilizing axial Rayleigh-Benard convection currents caused by heat generation. We show that heat generation is not necessarily deleterious to plasmonic nanotweezers and achieve dexterous manipulation of nanoparticles with non-resonant illumination of BNAs.
Multiorgan system failure caused by valproic acid toxicity

Valproic acid is an effective antiseizure medication that is also used for other indications such as migraine prophylaxis. It is known to sometimes cause hepatic injury, both a mild dose-related form and an idiosyncratic, fulminant, usually fatal type. A case is reported of multiorgan failure caused by valproic acid toxicity in an adult who survived. Such multisystem toxicity has not been previously reported.
Peristomal pyoderma gangrenosum

Pyoderma gangrenosum (PG) is an idiopathic ulcerative skin disease that may be the cutaneous manifestation of many systemic diseases. Although the ulcers usually appear on the lower extremities, we report a case of peristomal pyoderma gangrenosum in a 25-year-old white female after proctocolectomy and ileostomy for ulcerative colitis. A total of 17 other cases of peristomal PG have been reported to date. In addition to the site of the ulcers, the case is remarkable because the patient was refractory to multiple trials of systemic therapy, including cyclosporine, until issues of local wound care were addressed. Effective local treatment was achieved using a calcium alginate dressing overlying pulverized sucralfate applied to the ulcers as well as enlarging the size of the ostomy bag opening. These local measures combined with systemic cyclosprine and prednisone led to complete ulcer healing in 9 weeks.
Unfreezing the Flexnerian Model: introducing longitudinal integrated clerkships in rural communities.

Introduction: Physician shortages in rural areas remain severe but may be ameliorated by recent expansions in medical school class sizes. Expanding student exposure to rural medicine by increasing the amount of prolonged clinical experiences in rural areas may increase the likelihood of students pursuing a career in rural medicine. This research sought to investigate the perspective of rural physicians on the introduction of a rurally based nine-month Longitudinal Integrated Clerkship (LIC). Methods: In this mixed-methods study, nine physician leaders were interviewed from five Maine, USA, rural hospitals participating in an LIC. Semi-structured interviews were audiotaped and transcribed. Qualitative analysis techniques were used to code the transcripts and develop themes. Forty-seven participating rural LIC preceptors were also surveyed through an online survey. Results: Four major themes related to implementing the LIC model emerged: (1) melting old ways, (2) overcoming fears, (3) synergy of energy, and (4) benefits all-around. The faculty were very positive about the LIC, with increased job satisfaction, practice morale, and ongoing learning, but concerned about the financial impact on productivity. Conclusions: The importance of these themes and perceptions are discussed within the three-stage model of change by Lewin. These results describe how the innovative LIC model can conceptually unfreeze the traditional Flexnerian construct for rural physicians. Highlighting the many stakeholder benefits and addressing the anxieties and fears of rural faculty may facilitate the implementation of a rural LIC. Given the net favorable perception of rural faculty of the LIC, this educational model has the potential to play a major role in increasing the rural workforce.
Exploring Mental Representations for Literal Symbols Using Priming and Comparison Distance Effects.

Higher-level mathematics requires a connection between literal symbols (e.g., ‘x’) and their mental representations. The current study probes the nature of mental representations for literal symbols using both the priming distance effect, in which ease of comparing a target number to a fixed standard is a function of prime-target distance, and the comparison distance effect, in which ease of comparing two numbers depends on the distance between them. Can literal symbols that have been assigned magnitude access mental representations of quantity to produce distance effects? Forty participants completed number comparison tasks involving Arabic numerals and literal symbols, a training task, and a working memory task. While both distance effects were present with Arabic numerals, there was no evidence of either with literal symbols. Results suggest that literal symbols may not share the same mental representations of magnitude as other number formats or may access them differently. Additional research is needed to understand mental representations utilized in higher-level mathematics (e.g., algebra), which includes both Arabic numerals and literal symbols.
Introduction to the OR Forum Article: “An Algorithmic Approach to Linear Regression”.

Comment on “An Algorithmic Approach to Linear Regression” by Dimitris Bertsimas and Angela King.