cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of high dose angiotensin-converting enzyme inhibition on restenosis: Final results of the MARCATOR study, a multicenter, double-blind, placebo-controlled trial of cilazapril

Objectives. We conducted a randomized, double-blind, placebo-controlled trial to assess the effect of low and high dose angiotensin-converting enzyme inhibition with cilazapril on angiographic restenosis prevention after percutaneous transluminal coronary angioplasty. Background. Angiotensin-converting enzyme inhibitors possess antiproliferative effects in animal models of vascular injury. However, a recent clinical trial using low dose cilazapril, a long-acting angiotensin-converting enzyme inhibitor, failed to prevent restenosis. Methods. Patients received either cilazapril (1 or 2.5 mg in the evening after successful coronary angioplasty, then 1, 5 or 10 mg twice daily for 6 months) or matched placebo. All patients received aspirin for 6 months. Coronary angiograms before and after angioplasty and at 6-month follow-up were quantitatively analyzed. In addition, the clinical, procedural and angiographic factors associated with restenosis were determined with the use of stepwise logistic analysis. Results. A total of 1,436 patients with a successful coronary angioplasty were recruited. As assessed by an intention-to-treat analysis, the mean difference in minimal coronary lumen diameter (mean ± 1 SD) between the postangioplasty and follow-up angiogram at 6 months (primary end point) was −0.35 ± 0.51 for the placebo group and −0.37 ± 0.52, −0.45 ± 0.52 and −0.412 ± 0.53, respectively, for the 1-, 5- and 10-mg twice daily cilazapril groups (p = NS). Clinical events during follow-up did not differ among the four study groups. Multivariate analysis revealed only six variables as independent predictors of the loss of minimal lumen diameter: duration of angina <6 months, history of myocardial infarction, minimal lumen diameter before and after angioplasty as well as a proximal lesion location and reference diameters. Traditional risk factors for atherosclerosis did not relate to restenosis. Conclusions. Long-term angiotensin-converting enzyme inhibition with cilazapril in high as well as low dosages does not prevent restenosis and does not favorably influence the overall clinical and angiographic outcome after coronary angioplasty. Few factors are predictive of restenosis.
Apoptosis in the digestive tract of herbivorous Rana pipiens larvae and carnivorous Ceratophrys ornata larvae: an immunohistochemical study.

The lifespan of herbivorous Rana pipiens larvae is ∼3 months, while that of carnivorous Ceratophrys ornata larvae is only about 2 weeks. During metamorphic climax, the larval gut shortens dramatically, especially in R. pipiens, and its luminal epithelium is replaced by adult-type epithelium. To determine when programmed cell death occurs during the metamorphic restructuring of the gut, we prepared cross-sections of the stomach, small intestine, and large intestine from representative larval stages and from juvenile frogs of both species. The sections were incubated with monoclonal antibody against active caspase-3, one of the key enzymes in the apoptotic cascade. We observed apoptosis in some luminal epithelial cells in each of the three regions of the larval gastrointestinal tract of both species. However, apoptotic cells appeared earlier in larval stages of R. pipiens than C. ornata and few were seen in juvenile frogs of either species. The results demonstrate the occurrence of apoptosis in the metamorphic remodeling of the gut of both R. pipiens larvae and C. ornata larvae. J. Morphol., 2011. © 2011 Wiley Periodicals, Inc.
Numerical analysis of blast-induced wave propagation using FSI and ALEmulti-material formulations

Abstract As explosive blasts continue to cause casualties in both civil and military environments, there is a need to identify the dynamic interaction of blast loading with structures, to know the shock mitigating mechanisms and, most importantly, to identify the mechanisms of blast trauma. This paper examines the air-blast simulation using Arbitrary Lagrangian Eulerian (ALE) multi-material formulation. It will explain how the fluid–structure interaction (FSI) can be simulated using a coupling algorithm for the treatment of the fluid as a moving media by a moving mesh using ALE formulation and how the structure is treated on a deformable mesh using a Lagrangian formulation. To validate the numerical approach, as well as to prove its ability to simulate complicated scenarios, comparison of three distinct blast scenarios, i.e., blast from C-4 and TNT in open space and blast on a circular steel plate, with the experimental data was performed. The predicted numerical results match very well with those of experiments. This computational approach is able to accurately predict the relevant aspects of the blast–structure interaction problem, including the blast wave propagation in the medium and the response of the structure to blast loading.
Epidemiology of neonatal necrotising enterocolitis: a population-based study

We examined the birthweight-, gender- and race-specific incidence as well as the biodemographic and clinical correlates of necrotising enterocolitis (NEC) in a well-defined six-county perinatal region in upstate New York. We conducted a retrospective, 8-year population-based survey to identify all cases of proven NEC (modified Bell stage II and above) in the area's regional neonatal intensive care unit (NICU). The denominator used to calculate the incidence was obtained from the Statewide Planning Research Cooperative System. Incidence was expressed as cases per 1000 live births. A total of 85 documented cases of proven NEC was identified in a six-county perinatal region that experienced 117 892 live births during the 8-year period. The average annual incidence was 0.72 cases per 1000 live births [95% CI 0.57, 0.87 per 1000 live births]. The highest incidence of NEC occurred among infants weighing 750-1000 g at birth and declined with increasing birthweight. The urban county had a 1.53 times higher risk of NEC than rural counties [95% CI 0.9, 2.6]. The overall incidence of NEC for non-Hispanic blacks was significantly greater than that for non- Hispanic whites (2.2 vs. 0.5 cases per 1000 live births, P = 0.00). The differences remained statistically significant even after correction for birthweight. Most cases (93%) in this series were preterm (gestational age <37 weeks). Only two patients were never fed before the diagnosis of NEC was confirmed. Positive blood cultures were documented in 27% of the cases with a predominance of Gram-negative enteric micro-organisms. NEC remains an important health problem especially for preterm infants and the non-Hispanic black population.
Stealth Bombers, Advanced Cruise Missiles, and Superpower Deterrence Stability

Projected technical improvements in the "air-breathing" portion of the strategic force structure may work to destabilize superpower deterrence. This article examines potential threats to nuclear deterrence stability posed by the introduction of the advanced cruise missile and the advanced technology bomber, two technical improvements expected to arrive in superpower arsenals by the mid-1990s. While advanced technology bombers may not degrade strategic warning time, the advanced cruise missile does threaten to reduce warning and reaction time to the point where it increases the risks to deterrence stability.
Downstream boundary effects on the frequency of self-excited oscillations in transonic diffuser flows

An investigation of downstream boundary effects on the frequency of self-excited oscillations in two-dimensional, separated transonic diffuser flows has been conducted numerically by solving the compressible, Reynolds-averaged, thin-layer Navier-Stokes equation with a two-equation turbulence model. It was found that the unsteady diffuser flowfields are very sensitive to the location of the downstream boundary. Extension of the diffuser downstream boundary significantly reduces the frequency and amplitude of oscillations for pressure, velocity and shock. Computational results suggest that the mechanism causing the self-excited oscillation changes from viscous convective wave dominated oscillations to inviscid acoustic wave dominated oscillations when the location of downstream boundary varies from 8.66 to 134.7 throat height. The existence of a suction slot in the experimental setup obscures the physical downstream boundary and, therefore, presents a difficulty for quantitative comparisons between computation and experiment.
Electrocatalysis of anodic, oxygen-transfer reactions at noble metal electrodes

A large number of anodic oxygen-transfer reactions were studied at Au electrodes in both acidic and alkaline media. Results of competitive adsorption studies are interpreted to support the conclusion that adsorption is a prerequisite to subsequent oxygenand electron-transfer steps. Many of these oxidation reactions gave the voltammetric appearance of reversible waves, even though the observed half-wave potential values were shifted hundreds of millivolts positive of the thermodynamic potentials. A catalytic mechanism is proposed in which adsorbed hydroxyl radicals (AuOH) participate in the oxygen-transfer step. The absence of pH effects on half-wave potentials for several inorganic compounds suggests that the electron transfer precedes the deprotonation step for these reactants.
The Awful Truth: Unflattering Portraits in A Serious Man, and Precious

Minority groups are often justified in being watchful for the difficulties that negative reputations can bring on them. The necessity for discovery and discussion of serious issues within a minority community is real, but the resistance to such a candid approach is founded in their position of vulnerability and the power of old stereotypes. Two recent movies, A Serious Man and Precious, in spite of their enthusiastic reception by movie critics and audiences, are viewed with uneasiness by some commentators in the Jewish and African-American communities. This negative view is predictable and unavoidable. It reminds us that even hyper-sensitive minorities have real enemies.
Application Of A Digital Beam Attenuator To Chest Radiography

Although image quality in chest radiography can be improved dramatically with compensating attenuators, it is difficult to match attenuator geometry to that of the patient and to properly position the filter in the x-ray beam. We are developing a system which will fabricate a compensating filter specific for individual patient anatomy and position the filter automatically. A low-dose image is acquired from which the attenuator is designed using a hardwired algorithm. The attenuator then is typed in multiple layers of a cerium oxide material onto a sheet of paper with a dotmatrix printer. Following positioning of the attenuator in the x-ray beam, the final compensated image is acquired with a photographic or electronic detector. Initial studies with our prototype digital beam attenuator have produced images with improved image quality. The improvement occurs because the attenuator allows the entire image to be placed in the linear portion of the film characteristic curve. In addition, decreased scatter fractions and increased signal-to-noise contribute to improved visualization of low-contrast signals behind the most attenuating regions of the patient.
A New Method for Quantitative Real-Time Polymerase Chain Reaction Data Analysis

Quantitative real-time polymerase chain reaction (qPCR) is a sensitive gene quantification method that has been extensively used in biological and biomedical fields. The currently used methods for PCR data analysis, including the threshold cycle method and linear and nonlinear model-fitting methods, all require subtracting background fluorescence. However, the removal of background fluorescence can hardly be accurate and therefore can distort results. We propose a new method, the taking-difference linear regression method, to overcome this limitation. Briefly, for each two consecutive PCR cycles, we subtract the fluorescence in the former cycle from that in the latter cycle, transforming the n cycle raw data into n-1 cycle data. Then, linear regression is applied to the natural logarithm of the transformed data. Finally, PCR amplification efficiencies and the initial DNA molecular numbers are calculated for each reaction. This taking-difference method avoids the error in subtracting an unknown background, and thus it is more accurate and reliable. This method is easy to perform, and this strategy can be extended to all current methods for PCR data analysis.
"Worthless female material": nursemaids and governesses in Freud's cases.

The figure of the governess, central in Freud’s own history, is present in most of his cases. Freud described his nursemaid as “the prime originator” of his neuroses. Well after Freud’s abandonment of the seduction theory, female servants were consistently portrayed as seducing boys, while their relationship with girls consisted of identification and rivalry. The role of Freud’s own surrogate mother in his life and writing is examined, and two cases, Lucy R. and Dora, are looked at through the lens of female caretaking. A review and integration of relevant literature is followed by an exploration of the perplexing adherence in Freud’s writing to the reality of seduction by a governess, even after he had abandoned the seduction theory. It is argued that it is in the figure of the female maid that the “shadowy” early history of Freud’s mothering experiences may actually be engaged, however indirectly and unconsciously. This figure, and Freud’s powerful, problematic identification with her, is a thread that ...
The heat capacity of lead from 300 to 850 °K: Experimental data

The heat capacity of high purity solid and liquid lead has been measured, using adiabatic calorimetry, from 300 to 850 °K. The data for the solid and the liquid have each been fitted to a polynomial and at least 92 per cent of the data points lie within ±1% of each polynomial. The error of the measurements is considered to be within ±1%. The data of solid lead were obtained on both a single crystal and a polycrystalline specimen; no significant difference in the heat capacity was obtained. The heat capacity of the liquid decreased monotonically from the melting point to the upper limit of measurement, 850 °K. Es wurden die spezifischen Warmen von festem und flussigem Blei mit hohen Reinheitsgrad unter Benutzung eines adiabatischen Kalorimeters von 300 bis 850 °K gemessen. Die Ergebnisse wurden durch eine endliche Reihe dargestellt, wobei mindestens 92% der Meswerte nur um ±1% von der Kurve abwichen. Der Fehler der Messungen durfte bei ±1% liegen. Die Meswerte fur festes Blei wurden an Einzelkristallen und auch an polykristallinen Proben ermittelt, ohne das sich merkbare Unterschiede fur die spezifische Warme ergaben. Die spezifische Warme von flussigem Blei verminderte sich laufend vom Schmelzpunkt bis zu der oberen Grenze der Messungen, die bei 850 °K lag.
Promoter Architecture Dictates Variability in Gene Expression

Recent experimental studies have reported that cell-to-cell variability in gene expression is a universal function of mean gene expression levels, implying that knowledge of mean levels of gene expression alone is sufficient to determine the level of variability. This result seems at odds with the physical intuition underlying efforts in the literature to predict the level of variability for different promoter architectures (where we take “promoter architecture” to mean the numbers, positions, and strengths of transcription factor and RNA polymerase binding sites). For instance, we would expect slow TF binding/unbinding kinetics to yield a relatively higher level of variability at a given mean than fast kinetics, as the switching between distinct transcriptional states will yield a broad distribution in mRNA production. To address this apparent conundrum, we constructed a set of 18 constitutive (unregulated) promoters with expression levels spanning a range of 2.5 orders of magnitude, and found that the observed mRNA distributions were consistent with Poissonian production of mRNA. We then placed one of these promoters under regulation by the repressor transcription factor LacI, and measured the resulting mRNA distributions at a range of LacI concentrations. We found that, for the regulated promoter, the level of variability as a function of mean expression followed a distinct, promoter architecture dependent curve as compared with the unregulated promoter. These results demonstrate that the level of variability in gene expression depends on the specific promoter architecture in play.
Scalar coupling across the hydrogen bond in 1,3- and 1,4-diols.

Scalar coupling between hydroxyl groups sharing a 1,4- or 1,3-intramolecular hydrogen bond can be readily detected using standard 2D NMR techniques. Analyses of isotopically perturbed 2D J-resolved spectra have revealed h2J to be on the order of 0.3 Hz in systems such as diols 2 and 3. A standard 2D COSY experiment, modified to detect small coupling constants, is shown to be a convenient method for detecting h2J in these systems. Couplings derived from density functional finite perturbation theory (DFT/FPT) are found to be in general agreement with experimental data.
Wetting of SiC, Si3N4, and Carbon by Si and Binary Si Alloys

The wetting of several new materials for gas turbine engines, e.g. SiC, Si3N4, and C, by liquid Si and binary Si alloys containing Cu, Fe, and B was determined by the sessile drop method. All contact angles measured were < 90°. Hot-pressed SiC, Si3N4, and Refel SiC are easily wet by Si; wetting is controlled by the balance of interfacial energies. Carbon is wet well by Si, but wetting is controlled by reaction and, in some carbons, by infiltration of Si into C. Additives to Si such as B and Fe can form compounds in reaction zones during wetting at interfacial areas.
A new ant genus from the Greater Antilles and Central America, Zatania (Hymenoptera: Formicidae), exemplifies the utility of male and molecular character systems

The ant genus Prenolepis (Hymenoptera: Formicidae) is the nominal member of the recently established Prenolepis genus-group within the subfamily Formicinae. Our molecular phylogenetic analyses using fragments from five nuclear genes (arginine kinase, carbomoylphosphate synthase, elongation factor 1-alpha F1, elongation factor 1-alpha F2, wingless) and one mitochondrial gene (cytochrome oxidase I) indicate that this genus is polyphyletic. Although the majority of Prenolepis species was found to belong to the same monophyletic group (Prenolepis sensu stricto), a smaller subset of Prenolepis species, all found in either Central America or the Greater Antilles, was robustly inferred to comprise a distinct lineage that is sister to the Old World genus Paraparatrechina. Here we describe this newly discovered lineage within the larger Prenolepis genus-group clade. The genus Zatania, gen.n. is composed of five extant species (Zatania albimaculata, Zatania cisipa, Zatania gibberosa, Zatania gloriosa, sp.n. and Zatania karstica) and one Dominican amber fossil species (Zatania electra†, sp.n.). These are medium-sized ants (generally between 2.5 and 3 mm in total length) that are characterized by having long scapes and legs, and elongated mesosomata. A reliance on worker-based taxonomy has previously prevented the discovery of this new lineage because of worker convergence consisting of various combinations of elongated mesosomata, long scapes and legs, and a constriction immediately behind the pronotum, observed in several distinct lineages within the Prenolepis genus-group. However, we did find that male morphology complements our molecular results in revealing important diagnostic and potentially phylogenetically informative characters. Our study highlights the value for ant systematics to expand beyond its traditional foundation of worker-based morphology and embrace character systems from other castes and molecular data.
Mechanism of Simultaneous Iodination and Coupling Catalyzed by Thyroid Peroxidase

Abstract Thyroid peroxidase (TPO) simultaneously catalyzes two very different types of reaction in the thyroid gland—iodination and coupling. The present study addresses the mechanism of this simultaneous dual activity. Compound I, the two-electron oxidation product of TPO, exists in two different forms—an oxoferryl porphyrin π-cation radical and an oxoferryl protein radical. It has been proposed that iodination is mediated by the porphyrin π-cation radical form of TPO compound I, while coupling is mediated by the protein radical form. However, results obtained in the present study favor the view that both iodination and coupling are mediated by the porphyrin π-cation radical form of compound I. In the first part of the study, we compared coupling and iodination activities of two peroxidases with very similar crystal structures—cytochrome c peroxidase (CcP) and lignin peroxidase (LiP). Although these two peroxidases have very similar three-dimensional structures, CcP forms a compound I only of the protein radical type, whereas compound I of LiP exists only as a porphyrin π-cation radical. Comparison of the catalytic activities of the two enzymes showed that diiodotyrosine (DIT)-stimulated coupling activity of LiP was significantly greater than that of CcP. Moreover, lignin peroxidase displayed very significant iodinating activity at acid pHs, whereas iodination with CcP was negligible at all pHs tested. Our findings with these two structurally similar peroxidases suggested that TPO-catalyzed iodination and coupling could both be mediated by the porphyrin π-cation radical form of compound I. More direct evidence in support of this view was obtained in the second part of this study, employing TPO and lactoperoxidase (LPO) model systems in which iodination and coupling occurred simultaneously. Heme spectral analysis was used to correlate formation of the protein radical form of compound I with the kinetics of the iodination and coupling reactions. Formation of the compound I protein radical was not observed until the iodination and coupling reactions had almost been completed. In separate experiments it was shown that the spontaneous conversion of the porphyrin π-cation radical form of TPO or LPO compound I to the protein radical form was markedly inhibited by a low concentration of iodide, especially in the presence of an iodide acceptor. These studies provide compelling evidence that both iodination and coupling are mediated by the porphyrin π-cation radical form of compound I. This was further substantiated by the finding that coupling was inhibited in the presence of excess iodide, an observation readily explained by competition between iodide and DIT residues in thyroglobulin for oxidation by the porphyrin π-cation radical.
A heart model for understanding three‐dimensional cardiac anatomy

A simple procedure for making cardiac casts has been described. These casts aid in the understainging of the special relationships of the ventricles, valves and coronary arteries as they appear at the time of cardiac angiography.
Formic Acid Modified Carbon Dioxide as a Mobile Phase in Capillary Supercritical Fluid Chromatography

A small percentage (0.3 % w/w) of formic acid was added to supercritical carbon dioxide to increase mobile phase polarity and improve separation of polar solutes on three different commercially available capillary columns. Formic acid reduced retention and altered selectivity for several polar compounds. Thermodynamic studies revealed that the enthalpy of solvation was as much as 27 kcal mol-' more negative when formic acid was added due to increased solute-solvent interactions. Entropy measurements show that formic acid modified mobile phase is more ordered than a pure carbon dioxide mobile phase, apparently as a result of modifier clustering around polar solutes. Van't Hoff plots for some very polar solutes showed a region of retrograde behavior at low temperatures and pressures, indicating an increase in modifier clustering. Comparisons between pure and modified mobile phases were also made by examining practical separations obtained with each, revealing differences in retention, selectivity and peak shape.
Objective Standard Setting for Judge-Mediated Examinations

Judge-mediated examinations are defined as those for which expert evaluation (using rubrics) is required to determine correctness, completeness, and reasonability of test-taker responses. The use of multifaceted Rasch modeling has led to improvements in the reliability of scoring such examinations. The establishment of criterion-referenced standards for these assessments has, however, remained a labor-intensive practice. This article explores a method for incorporating the establishment of minimal competency within the measurement model itself. Two high-stakes testing boards participated in a controlled experiment comparing a multifaceted Rasch modeled approach to a traditional modified borderline approach often used for standard setting in judge-mediated situations. Criterion points from each were compared to assess differences and support validity. Results of the experiment suggest that modeling standard setting as part of the performance evaluation is an effective and efficient way to define minimal co...
Field and laboratory studies on the pathogenicity of the fungus Beauveria bassiana to three genera of mosquitoes.

The ability of the fungus Beauveria bassiana to kill mosquito larvae, adults, and eggs was challenged with Culex tarsalis, Culex pipiens, Anopheles albimanus, Aedes aegypti, Aedes sierrensis, and Aedes nigromaculis. B. bassiana was found most effective in killing larvae when applied as a conidial dust to the surface of the water. This was attributed to the primary sites of invasion being the perispiracular lobes of the larval siphon. During May and June of 1966, the mortality of C. pipiens larvae in outdoor test ponds ranged from 70% to 95% following an application of 3 lb. of viable conidia per acre. The Anopheles and Culex larvae tested all proved to be susceptible to the fungus while the Aedes larvae were not. In laboratory tests against the adults of C. tarsalis, C. pipiens, A. aegypti, A. sierrensis, A. nigromaculis, and A. albimanus, conidia of B. bassiana produced 100% mortality within 5 days after exposure, while less than 50% occurred in corresponding controls. Outdoor tests against the adults of A. nigromaculis in screen cages were less successful, yielding only 58% mortality. In this case, the fact that adults rested on the screen walls of their test cages, rather than in the dusted grass that had been provided, may explain the low mortality. Eggs of Culex and Aedes exposed to the conidia of B. bassiana hatched normally.
Mannose and the ‘Crowding effect’ of Hymenolepis in rats

Abstract Hymenolepis diminuta from rats infected with 10 cysticercoids and fed on a diet containing 3% (w/w) mannose for 4 weeks were found to be, on average, much heavier in terms of dry weight (46 mg) than those from rats fed on diets containing an equivalent concentration of either galactose, glucose or fructose (18 mg). Subsequently, the numbers, egg production and dry weights of worms were determined from rats which had been infected with doses varying from 0 to 160 cysticercoids per rat and fed on diets containing either 0, 1, 4, or 8% mannose (w/w). Density-dependent decreases in both worm dry weight and egg production were detected at 5 weeks post-infection, but both the number of worms recovered and their prepatent period appeared to be independent of cysticercoid dose. Differences in the distribution pattern of individual worm dry weights were observed between rats harbouring low (1–15) and high (16–135) worm burdens. Worms recovered from rats infected with 10 cysticercoids and fed on a diet containing 4% mannose (w/w) for 3 weeks were found to be, on average, more than twice as heavy (37 mg) as those from rats fed on diets containing 1, 2, or 8% mannose (w/w) for equivalent periods of time (16 mg). The results indicate that the ‘crowding effect’ cannot be explained simply in terms of inter-worm competition for carbohydrate.
Estimating Classification Error to Identify Biomarkers in Time Series Expression Data

One of the primary objectives in the study of human diseases is the development of accurate and early diagnostic tests using molecular profiling technology. These investigations usually focus on feature selection with the goal of building a classifier using only the most clinically relevant features. With time series molecular profiles, each patient's assay contains observations measured at several time points. Using traditional time series classification methods, we can only determine a patient's diagnosis after obtaining all time points, eliminating the possibility of early diagnosis. This problem can be alleviated by dividing the time series into smaller overlapping sub-series. Unfortunately, these sub-series are not independent and identically distributed (iid). Consequently, when we estimate classification error for feature selection using traditional methods, we may encounter estimation bias. In response, we have developed a novel method that ranks time series biomarkers using specialized blocked error estimation methods designed to reduce estimation bias. Our investigation applies special cross validation and bootstrap methods, including h-block, hv-block cross validation, and blocked bootstrap to synthetic and clinical time series data. Results indicate a clear decrease in estimation bias using these methods on synthetic time series data. Similar results for a drug treatment dataset show further evidence that these blocked algorithms can improve biomarker identification.
Structural and regenerative changes in old-growth piñon–juniper woodlands following drought-induced mortality

Abstract Two decades of drought and rising temperatures have triggered bark beetle outbreaks and extensive mortality of Colorado pinon (Pinus edulis) and Utah juniper (Juniperus osteosperma) across the southwest US. For example from 2002 to 2005, over one-third of the pinons in Mesa Verde National Park’s old-growth woodlands were killed by the bark beetle Ips confusus and other drought-related factors. Extensive wildfires have also burned through the Park over the last two decades, reducing the extent of old-growth woodlands by nearly one-half. We compared historical (1970–1990s) and recent (2005–2011) data to gauge the effects of the 2002–2005 mortality event on canopy structure, woody surface fuels, and tree recruitment. Large, mature pinons were the most susceptible to mortality; we measured significant reductions in pinon cover and diameter. Due to the loss of large trees, woodlands that were subjected to substantial mortality had reduced structural complexity relative to nearby unaffected stands. In a longitudinal fuels comparison, 2010–2011 fuels were compared to historical 1993 values in the same plots; we could not detect a change in woody fuel load. However when the 2010–2011 fuels are compared across mortality severity classes, there was a trend toward slightly greater 1–100 h, greater 1000 h fuel loads, and more litter in stands with higher levels of tree mortality. However, modeled surface fire behavior did not differ across mortality severity classes. Modeled crown fires needed higher wind speeds to spread from tree to tree in stands without tree mortality, but this is likely due to the inherently more open canopy structure in stands that resisted mortality rather than due to tree mortality per se. Post-mortality pinon reproduction and recruitment were recorded from 2005 to 2011 and compared with NPS monitoring data from 1975 to 1995. Cone production in 2005 was comparable to historical trends, but recent seedling and sapling densities were significantly below historical values. Yearly seedling and sapling density in 1975–2011 was positively correlated with precipitation during the sampling year and two years prior. The largest proportion of seedlings and saplings occurred under pinon or juniper canopies, and a smaller proportion under native shrubs. Given the loss of a substantial component of the adult trees, reduced stand structural complexity, and demonstrated need for moist conditions and nurse plants for effective recruitment, these old-growth woodlands may be vulnerable to decline under future warm and dry climate projections. Management strategies focusing on maintaining structural features of both the overstory and understory could help provide conditions for sustainable recruitment and contribute to the goal of conservation of rare old-growth pinon–juniper woodlands.
Conformal and reconfigurable fractal antennas

The fractal antennas with multi-band and multi-functional capabilities have been very actively studied in the recent years. In contrast, the fractal antenna presented here combines properties of the dielectric substrates with the well-known characteristics of fractal patterns, to result in a wideband conformal antenna. The input characteristics of the antenna is experimentally found to be better than -10 dB for a very band of frequencies from MHz to few GHz band. Another important characteristics of the fractal antennas introduced her is the possibility of making a reconfigurable antenna with this approach. Preliminary simulation results for a fractal reconfigurable antenna are presented here.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The nature of general surgery resident performance problems.

Background Residents with performance problems are challenging to program directors and complicate the work of other residents and health care providers. Having an effective, targeted remediation process to address these problems is dependent on being able to diagnose their nature. The purpose of this study was to identify residents who had serious, substantive, and recurring academic, clinical, and/or professional behavior problems, and to describe and classify their nature. Methods Raters performed a retrospective record review of general surgery categorical residents in one program over 30 years. Residents with substantial problems were reviewed, described, and classified independently by 3 raters. Results Seventeen residents had serious enough performance problems to be included. Four had only 1 class of problem (3 were professional behavior problems). Eight residents had 2 problems each (5 academic and clinical performance problems; 3 clinical performance and professional behavior problems). Five residents had 3 problems. The number of performance problem facets per case varied from 11 to 2 with an average of 5.9 facets. Relations with health care workers was identified most frequently, followed closely by insufficient knowledge. Poor communication was third. Performance problems of 14 residents (82%) were identified in their first year. For 15 cases, the resident had unresolved performance problems at the end of the program. Conclusion There are 2 possible explanations for our findings: (1) resident problems similar to these are refractory to remediation; (2) treatments used historically are not well designed for the problems. Choosing among the 2 explanations will require developing remediation strategies targeted to specific patterns of performance problems.
THE ROLE OF COMPETITIVE GROUPS IN STRATEGY FORMULATION: A DYNAMIC INTEGRATION OF TWO COMPETING MODELS*

Alternative conceptualizations of competitive groups have been developed in the strategic management literature, namely, the ‘strategic group’and the ‘cognitive group’. These two views each have their own paradigm base and are often seen as incompatible explanations of intra-industry structure. This article analyses these two views and presents a model for each. It then goes on to develop an integrated model which uses both concepts as tools in framing strategy research. Propositions about the new model are also presented.
Too Cold for a Jog? Weather, Exercise, and Socioeconomic Status

This study examines how exercise responds to plausibly exogenous "price shocks," in the form of weather conditions. Most notably, we find that within cold temperature ranges, a decrease in past-month temperature causes a significant decrease in past-month exercise, and this effect is generally larger for lower education and income groups. In large part this differential by socioeconomic group appears to be due to smaller increases in indoor activity during cold weather. These results suggest that interventions and policies aiming to increase exercise participation, particularly among lower socioeconomic populations, could do so in part by increasing the availability and attractiveness of indoor facilities and activities. Furthermore, to the extent that the higher elasticity of behavior for lower socioeconomic groups reflects a more general sensitivity to external factors, these results highlight the promise of interventions that address such factors more broadly.
Investigation of a Technique for Providing a Pseudo-Continuous Detector Ring for Positron Tomography

The use of small bismuth germanate (BGO) detectors (2.5-4.5 mm wide) and a simple coding technique for identification of the crystal of interaction with the impinging gamma-ray was investigated in terms of a technique for providing a positron tomography system of the highest possible intrinsic resolution with the additional capability of providing an artifact free image in a stationary system. The technique employs one photomultiplier per two BGO crystals in a scheme of alternating single PMT/crystal and shared PMT/crystal combinations to form a pseudo-continuous ring. Problems of crosstalk between detectors, nonuniform sensitivities and variable resolution are shown to be minimized once discriminator thresholds are clearly above the energy of the bismuth x-rays induced in the BGO crystals by the 511 keV gammas from the positron annihilations. A stationary circular system employing 4.5 mm wide BGO detectors can provide transverse sampling equal to 1/2 the center to center crystal distance or 2.5 mm sampling. The measured intrinsic resolution of a bench top version of this system is 5 to 6 mm FWHH for a 30cm diameter field of view for a 100 cm system diameter. The 2.5 mm sampling with reconstruction filter of appropriate frequency response should provide a high resolution image on the order of 7 to 8 mm FWHM with good signal to noise characteristics which is free of significant aliasing artifacts.
Bovine growth hormone treatment of channel catfish: strain and temperature effects on growth, plasma IGF-I levels, feed intake and efficiency and body composition

Channel catfish from two strains, USDA-103 and Norris, were reared in circular 800-l tanks and injected once weekly with 2.5 μg recombinant bovine growth hormone (rbGH) per gram body weight, or the saline vehicle. In addition to the rbGH, and strain treatments, half the tanks were supplied with well water of 26.0°C and the other half received water of 21.7°C. Growth rate, plasma insulin-like growth factor I (IGF-I) levels, feed consumption and body fatness of the fish injected with rbGH were higher than in saline-injected controls. Strain and temperature effects were also significant. Feed consumption was significantly greater with growth hormone treatment, higher temperature, and in the USDA-103 strain of catfish. Feed efficiency was significantly better in rbGH-injected fish. The effect of temperature on feed efficiency was also significant, higher temperature treatments performed better. Growth hormone enabled channel catfish to grow better at lower and higher temperatures than saline-treated counterparts.
An Ecological Perspective on Learning Progressions as Road Maps for Learning

The Black, Wilson, and Yao (this issue) provide a wide-ranging commentary and vision of the interrelationships among curriculum, pedagogy, and assessment. Specifically, they describe how the Berkel...
A bit‐pushing shortest distance algorithm

A bit manipulation method is given for finding shortest distances from an origin in an unweighted graph, or alternatively, for finding connected components. The basic approach is similar to some component algorithms already in the literature but an easy implementation is given that overcomes the problem which prevents the others from being efficient–namely, the problem of identifying the ones in a sparse bit string without checking all the bits. The algorithm would be most effective for moderate sized graphs (about 20–100 nodes). Computational results are given.
Collective Self-Esteem and Africultural Coping Styles in African American Adolescents

The authors examine the relationships between dimensions of collective self-esteem and Africultural coping styles in a sample of African American adolescents. They found that African American adole...
Simulating the initial stage of phenolic resin carbonization via the ReaxFF reactive force field.

Pyrolysis of phenolic resins leads to carbon formation. Simulating this resin-to-carbon process atomistically is a daunting task. In this paper, we attempt to model the initial stage of this process by using the ReaxFF reactive force field, which bridges quantum mechanical and molecular mechanical methods. We run molecular dynamics simulations to examine the evolution of small molecules at different temperatures. The main small-molecule products found include H_2O, H_2, CO, and C_2H_2. We find multiple pathways leading to H_2O formation, including a frequent channel via β-H elimination, which has not been proposed before. We determine the reaction barrier for H_2O formation from the reaction rates obtained at different temperatures. We also discuss the relevance of our simulations to previous experimental observations. This work represents a first attempt to model the resin-to-carbon process atomistically.
Approximating spheroid inductive responses using spheres

The response of high permeability ({mu}{sub r} {ge} 50) conductive spheroids of moderate aspect ratios (0.25 to 4) to excitation by uniform magnetic fields in the axial or transverse directions is approximated by the response of spheres of appropriate diameters, of the same conductivity and permeability, with magnitude rescaled based on the differing volumes, D.C. magnetizations, and high frequency limit responses of the spheres and modeled spheroids.
Cellular structures of carbon nanotubes in a polymer matrix improve properties relative to composites with dispersed nanotubes

Abstract A new processing method has been developed to combine a polymer and single wall carbon nanotubes (SWCNTs) to form electrically conductive composites with desirable rheological and mechanical properties. The process involves coating polystyrene (PS) pellets with SWCNTs and then hot pressing to make a contiguous, cellular SWCNT structure. By this method, the electrical percolation threshold decreases and the electrical conductivity increases significantly as compared to composites with well-dispersed SWCNTs. For example, a SWCNT/PS composite with 0.5 wt% nanotubes made by this coated particle process (CPP) has an electrical conductivity of ∼3 × 10 −4 S/cm, while a well-dispersed composite made by a coagulation method with the same SWCNT amount has an electrical conductivity of only ∼10 −8 S/cm. The rheological properties of the composite with a macroscopic cellular SWCNT structure are comparable to PS, while the well-dispersed composite exhibits a solid-like behavior, indicating that the composites made by this new CPP are more processable. In addition, the mechanical properties of the CPP-made composite decrease only slightly, as compared with PS. Relative to the common approach of seeking better dispersion, this new fabrication method provides an important alternative means to higher electrical conductivity in SWCNT/polymer composites. Our straightforward particle coating and pressing method avoids organic solvents and is suitable for large-scale, inexpensive processing using a wide variety of polymers and nanoparticles.
Vibrational frequencies and structural determination of dicyanodifluorosulfur.

Abstract The normal mode frequencies and corresponding vibrational assignments of dicyanodifluorosulfur are examined theoretically using the Gaussian03 set of quantum chemistry codes. Each of the vibrational modes was assigned to one of six types of motion predicted by a group theoretical analysis (C N stretch, S C stretch, S F stretch, F S C bend, S C N bend, and C S C bend) utilizing the C 2v symmetry of the molecule. A set of uniform scaling factors was derived for each type of motion. Predicted infrared and Raman intensities are reported.
The Production of Popular Music as a Confidence Game: The Case of the Chicago Blues

In this article I argue that the production of live music shares many formal properties with that of confidence games: specifically, (1) a set of structural relationships in which operators, ropers, insiders, shills and marks are enmeshed, (2) the deployment of carefully planned strategies of deception, and (3) a pattern of success owed in part to the moral and financial motivations of insiders, the willingness of the state to assist in the enterprise, and the desire among victims to be swayed by the production. Drawing on ethnographic research conducted in some of Chicago's most popular blues clubs, I examine these three components of live music production qua confidence game. I also briefly discuss how one group of participants—local blues musicians—reacts to their own performances as musicians/confidence artists. Finally, I conclude by exploring the broader implications this case suggests regarding other types of live music production.
Cementing a liner into a stable cementless acetabular shell: the double-socket technique.

Background: During revision hip replacement surgery, the cementless acetabular shell is often well fixed but the locking mechanism may be ineffective. Cementing a new liner into the existing acetabular shell (the double-socket technique) can provide a simple solution. The purposes of the present study were to review our initial clinical results and to define the potential limitations of this technique. Methods: Thirty-two hips with a preexisting well-fixed acetabular socket that had been in situ for an average of 8.6 years were treated with the insertion of a new polyethylene liner (seventeen hips) or a metal liner (fifteen hips) with use of cement. The indication for this technique was a deficient locking mechanism in twenty-two hips and the unavailability of a matching liner in ten hips. Anteroposterior radiographs of all hips were analyzed by a single independent reviewer. Results: The mean duration of follow-up was 5.1 years. Six hips required a reoperation after a mean of 29.7 months; the reasons for the reoperations included aseptic failure of the acetabular construct (four hips), instability (one hip), and sepsis (one hip). The University of California at Los Angeles hip scores improved significantly (p < 0.001) compared with the preoperative values; specifically, the mean score improved from 6.2 to 9.1 for pain, from 6.3 to 8.3 for walking, from 6.2 to 7.8 for function, and from 4.7 to 5.8 for activity. The prevalence of dislocation was 22%. Kaplan-Meier analysis with revision as the end point revealed a five-year survival rate of 78% (95% confidence interval, 55% to 91%). Conclusions: The double-socket technique is a good alternative to acetabular socket removal for suitable candidates who have a well-fixed cementless socket with an inner diameter that is larger than the outer diameter of the cemented liner. This technique preserves acetabular bone stock and permits conversion to alternate bearing surfaces. We believe, however, that removal of a well-fixed acetabular shell or the use of a constrained liner should be strongly considered for patients with a history of hip instability. Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.