cssi/SciSciGPT-SciSciNet huggingface dataset:
Kinetics and Selectivity of Deep Catalytic Oxidation of n-Hexane and Benzene

Deep (complete) catalytic combustion (oxidation) of volatile organic compounds (VOCs) is emerging as an important emission control technique. A fundamental study was carried out for low-temperature deep oxidation of n-hexane and benzene over a 0.1 % Pt, 3% Ni/γ-Al2O3 catalyst. These VOCs were subjected to oxidation as single components and as a binary mixture at temperatures ranging from 160 to 360°C. n-Hexane oxidation was significantly inhibited in the mixtures. An approach based on the Mars—Van Krevelen rate model was used to explain the results. Kinetic parameters were developed for the individual VOCs based on single component differential reactor data. These kinetic parameters were then incorporated into a proposed multicomponent Mars—Van Krevelen rate model to predict the experimental conversions in the binary mixture. The model was found to be reasonably successful in predicting the conversion of benzene and n-hexane in their binary mixture.
Occult Breast Tumor Reservoir: Biological Properties and Clinical Significance

Small, occult, undiagnosed breast cancers are found at autopsy in up to 15.6 % of women dying from unrelated causes with an average of 7 % from eight separate studies. The mammographic detection threshold of breast tumors ranges from 0.88 to 1.66 cm in diameter based on the patient’s age. Tumor growth rates, expressed as “effective doubling times,” vary from 10 to >700 days. We previously reported two models, based on iterative analysis of these parameters, to describe the biologic behavior of undiagnosed, occult breast tumors. Our models facilitate interpretation of the Women’s Health Initiative (WHI) and antiestrogen breast cancer prevention studies. A nude mouse xenograft model was used to validate our assumption that breast tumors grow in a log-linear fashion. We then used our previously reported occult tumor growth (OTG) and computer-simulated tumor growth models to analyze various clinical trial data. Parameters used in the OTG model included a 200-day effective doubling time, 7 % prevalence of occult tumors, and 1.16 cm detection threshold. These models had been validated by comparing predicted with observed incidence of breast cancer in eight different populations of women. Our model suggests that menopausal hormone therapy with estrogens plus a progestogen (E + P) in the WHI trial primarily promoted the growth of pre-existing, occult lesions and minimally initiated de novo tumors. We provide a potential explanation for the lack of an increase in breast cancer incidence in the subgroup of women in the WHI who had not received E + P prior to randomization. This result may have reflected a leftward skew in the distribution of occult tumor doublings and insufficient time for stimulated tumors to reach the detection threshold. Our model predicted that estrogen alone reduced the incidence of breast cancer as a result of apoptosis. Understanding of the biology of occult tumors suggests that breast cancer “prevention” with antiestrogens or aromatase inhibitors represents early treatment rather than a reduction in de novo tumor formation. Our models suggest that occult, undiagnosed tumors are prevalent, grow slowly, and are the biologic targets of a hormone therapy in menopausal women and of antiestrogen therapy for prevention.
Neotectonics of the Thakkhola graben and implications for recent activity on the South Tibetan fault system in the central Nepal Himalaya

The Thakkhola graben is one of many north-trending rifts that define the Neogene structural pattern of the southern Tibetan Plateau. Lying at the southern margin of the plateau and extending to the crest of the Himalaya, the graben provides an opportunity to evaluate the kinematic relationships between east-west extensional strain in southern Tibet and north-south extensional strain in the Himalaya. Neotectonic and structural mapping of the Dangardzong fault along the western margin of the graben reveals a southward-decreasing component of normal slip coupled with a southward-increasing component of right-lateral slip that affects Pleistocene basin-fill sediments. We present 14C ages for river terraces in the Thakkhola graben that provide a ca. 17.2 ka minimum age on the latest stage of Dangardzong fault movement. Near the southern termination of the graben, the Dangardzong fault apparently offsets the Annapurna detachment, an early (Miocene) strand of the east-striking South Tibetan fault system. However, the Dangardzong fault itself terminates against a young (i.e., younger than ca. 17.2 ka) strand of the South Tibetan fault system, the Dhumpu detachment. Structural relationships among the Dangardzong, Annapurna, and Dhumpu faults suggest that the Dangardzong structure is a tear fault in the South Tibetan allochthon that accommodates differential amounts and rates of displacement along the South Tibetan fault system. Thus, although the South Tibetan fault system first developed as part of the structural architecture of the Himalaya in Miocene time, at least some strands have been active as recently as the Pleistocene. In a regional context, the South Tibetan fault system serves to accommodate the strain gradient between extension in Tibet and shortening in the Himalaya.
Studies on copper metabolism. V. Storage of iron in liver of copper-deficient rats.

SummaryNo alteration from the normal in the uptake of parenterally administered radioiron into the saline-soluble and saline-insoluble fractions of liver iron was observed in copper-deficient albino rats.
An integral occuring in duration models with heterogeneity

Abstract Treatments of heterogeneity in duration models of the labor market often use a random effects specification which requires extensive numerical integration during estimation. This letter reports a rapidly computable series expansion for the integrals occuring in a wide variety of these models.
Drax's Reading in Neverwinter Nights: With a Tutor as Henchman:

This is an account of what a teacher educator learned from using the video game Neverwinter Nights with Drax, a high school student whose reading is like that of an elementary school student. Neverwinter Nights is a role-playing adventure game that requires reading print along with other meaningful signs such as sounds, artefacts, color, maps, etc. Using examples from eight hours of transcribed play, the author details the ways in which print matters to game play. Drax read walkthroughs which led to reading dialogues calling for practice with word recognition, which in turn led to acquiring new vocabulary. He also used strategies such as thinking aloud, rereading, and attending to details. Based on these findings, the author argues that it is worthwhile to explore and research opportunities for reading development within video games with print.
Cost comparison of syngas production from natural gas conversion and underground coal gasification

Underground coal gasification (UCG) is a promising technology to reduce the cost of producing syngas from coal. Coal is gasified in place, which may make it safer, cleaner and less expensive than using a surface gasifier. UCG provides an efficient approach to mitigate the tension between supplying energy and ensuring sustainable development. However, the coal gasification industry presently is facing competition from the low price of natural gas. The technology needs to be reviewed to assess its competiveness. In this paper, the production cost of syngas from an imaginary commercial-scale UCG plant was broken down and calculated. The produced syngas was assumed to be used as feedstock in liquid fuel production through the Fischer-Tropsch process or methanol synthesis. The syngas had a hydrogen (H2) to carbon monoxide (CO) ratio of 2. On this basis, its cost was compared with the cost of syngas produced from natural gas. The results indicated that the production cost of syngas from natural gas is mainly determined by the price of natural gas, and varied from $24.46 per thousand cubic meters (TCM) to $90.09/TCM, depending on the assumed price range of natural gas. The cost of producing UCG syngas is affected by the coal seam depth and thickness. Using the Harmon lignite bed in North Dakota, USA, as an example, the cost of producing syngas through UCG was between $37.27/TCM and $39.80/TCM. Therefore, the cost of UCG syngas was within the cost range of syngas produced by natural gas conversion. A sensitivity analysis was conducted to investigate how the cost varies with coal depth and thickness. It was found that by utilizing thicker coal seams, syngas production per cavity can be increased, and the number of new wells drilled per year can be reduced, therefore improving the economics of UCG. Results of this study indicate the competitiveness of UCG regarding to natural gas conversion technologies, and can be used to guide UCG site selection and to optimize the operation strategy.
SEM examination of corrosion product morphology for anodically polarized zinc

Abstract The morphology of anodic corrosion products formed under controlled conditions in sea water electrolyte was studied via scanning electron microscopy. Arrays of zinc oxide plates are observed, with a population density typically on the order of 10 6 plates/cm 2 . Individually, plates grow to about 30μm diameter and several μm thickness after one week exposure in zinc-steel couples. Plates grow with the ZnO basal planes parallel to the broad slow-growing faces. The preferred growth directions are perpendicular to prism planes.
Anthocyanin antioxidants from edible fruits

Abstract The edible fruits of 12 plants were extracted in methanol and subjected to solvent–solvent partitioning to yield three fractions, hexane, ethyl acetate, and aqueous. The semi-purified aqueous fractions were separated over Diaion HP-20SS resin to remove sugars and ascorbic acid. These fractions were then screened for antioxidant activity using the 1,1-diphenyl-2-picrylhydrazyl assay. Nine of the semi-purified fractions exhibited high antioxidant capacity. Cyanidin-3- O -β-glucopyranoside, an anthocyanin antioxidant, was identified from semi-purified aqueous fractions of the tropical fruit star apple ( Chrysophyllum cainito ), Surinam cherry ( Eugenia uniflora ), and jaboticaba ( Myrciaria cauliflora ). Delphinidin-3- O -β-glucopyranoside was identified from E. uniflora .
Transient rheology of the uppermost mantle beneath the Mojave Desert, California

Abstract Geodetic data indicate that the M7.1 Hector Mine, California, earthquake was followed by a brief period (a few weeks) of rapid deformation preceding a prolonged phase of slower deformation. We find that the signal contained in continuous and campaign global positioning system data for 2.5 years after the earthquake may be explained with a transient rheology. Quantitative modeling of these data with allowance for transient (linear biviscous) rheology in the lower crust and upper mantle demonstrates that transient rheology in the upper mantle is dominant, its material properties being typified by two characteristic relaxation times ∼0.07 and ∼2 years. The inferred mantle rheology is a Jeffreys solid in which the transient and steady-state shear moduli are equal. Consideration of a simpler viscoelastic model with a linear univiscous rheology (2 fewer parameters than a biviscous model) shows that it consistently underpredicts the amplitude of the first ∼3 months signal, and allowance for a biviscous rheology is significant at the 99.0% confidence level. Another alternative model – deep postseismic afterslip beneath the coseismic rupture – predicts a vertical velocity pattern opposite to the observed pattern at all time periods considered. Despite its plausibility, the advocated biviscous rheology model is non-unique and should be regarded as a viable alternative to the non-linear mantle rheology model for governing postseismic flow beneath the Mojave Desert.
Licensing Parents: A Response to Critics

The objections of three distinguished critics to my ‘Causes and Costs of Crime and a Controversial Cure’ (this issue) are welcomed but, in some cases, returned for further consideration.
Maternal exposure to exogenous sex hormones in relation to birth weight of offspring

Birth weight was analyzed among singleton live births (N = 665) in Upstate New York in 1974 to women who used oral contraceptives (OC) in comparison to live births to women who used no contraceptives (N = 716), within 11 months prior to last menstrual period (LMP). In addition, birth weight was examined among live births to women who received hormone support therapy (N = 97) and hormone pregnancy tests (N = 75) during pregnancy. There was no evidence for a reduction in mean birth weight, or an increase in frequency of lower weights, among births to OC users, including those who stopped using OC within 2 months of LMP. Generally similar findings held within three maternal age groups (less than 25, 25-29, and 30-39 years). There was no evidence for a reduction in birth weight among offspring of women who received hormone pregnancy tests. Mean birth weight was relatively low among male and female births to women who received hormone therapy for "threatened abortion," but this may reflect the selection of women for such treatment rather than an effect of exogenous hormones on fetal growth.
A Convenant Synthesis of 6-Formyl-5-Deazapterin

Abstract 6-Formyl-5-deazapterin, a key intermediate for the synthesis of a variety of 5-deaza analogues of folic acid, has been conveniently prepared by palladium-catalyzed coupling of 2-pivaloyl-6-bromo-5-deazapterin with siyrene, followed by ozonolysis of the resulting 6-styryl derivative, and final hydrolysis of the pivaloyl grouping. The penultimate compound in this sequence, 2-pivaloyl-6-formyl-5-deazapterin, is a partictularly convenient (and soluble) intermediate for further synthetic operations.
Proprioceptive endings in the myotomes of the pickerel (Teleostei: Esocidae)

Simple spray nerve endings of axons with a large diameter (15 μm) were located in the stratum compactum overlying the myotomal muscles in the pickerels, Esox niger and E. americanus. Based on the location of these nerve endings within the interwoven collagenous fibre matrix comprising the stratum compactum, and on the lack of reactivity to cholinesterase treatment, it is suggested that the endings are sensory in function and may be used as proprioceptors. These putative proprioceptors may aid the pickerel in monitoring the position of the body, (1) during ambush prey capture where the pickerel must lie motionless with as little disturbance in the water column as possible, and (2) in counteracting unwanted hydrodynamic forces such as pitch or roll brought about by sudden stopping of forward movement immediately following prey capture. This is the first report of proprioceptive endings associated with locomotor musculature in teleost fishes.
Inactivation of Bacillus anthracis spores in murine primary macrophages.

Summary The current model for pathogenesis of inhalation anthrax indicates that the uptake and fate of Bacillus anthracis spores in alveolar macrophages are critical to the infection process. We have employed primary macrophages, which are more efficient for spore uptake than the macrophage-like cell line RAW264.7, to investigate spore uptake and survival. We found that at a multiplicity of infection (moi) of 5, greater than 80% of the spores of the Sterne strain containing only the pXO1 plasmid were internalized within 1 h. Within 4 h post infection, viability of internalized Sterne spores decreased to approximately 40%. Intracellular vegetative bacteria represented less than 1% of the total spore inoculum throughout the course of infection suggesting effective killing of germinated spores and/or vegetative bacteria. The Sterne spores trafficked quickly to phagolysosomes as indicated by colocalization with lysosome-associated membrane protein 1 (LAMP1). Expression of a dominant-negative Rab7 that blocked lysosome fusion enhanced Sterne spore survival. Addition of d-alanine to the infection resulted in 75% inhibition of spore germination and increased survival of internalized spores of the Sterne strain and a pathogenic strain containing both the pXO1 and pXO2 plasmids. Inhibition was reversed by the addition of l-alanine, which resumed spore germination and subsequent spore killing. Our data indicate that B. anthracis spores germinate in and are subsequently killed by primary macrophages.
Impact of hydrolysis-mediated clearance on the pharmacokinetics of novel anaplastic lymphoma kinase inhibitors.

Compound 1 [(E)-4-fluoro-N-(6-((4-(2-hydroxypropan-2-yl)piperidin-1-yl)methyl)-1-((1S,4S)-4-(isopropylcarbamoyl)cyclohexyl)-1H-benzo[d]imidazol-2(3H)-ylidene)benzamide], a new, potent, selective anaplastic lymphoma kinase (ALK) inhibitor with potential application for the treatment of cancer, was selected as candidate to advance into efficacy studies in mice. However, the compound underwent mouse-specific enzymatic hydrolysis in plasma to a primary amine product (M1). Subsequent i.v. pharmacokinetics studies in mice showed that compound 1 had high clearance (CL) and a short half-life. Oral dose escalation studies in mice indicated that elimination of compound 1 was saturable, with higher doses achieving sufficient exposures above in vitro IC50. Chemistry efforts to minimize hydrolysis resulted in the discovery of several analogs that were stable in mouse plasma. Three were taken in vivo into mice and showed decreased CL corresponding to increased in vitro stability in plasma. However, the more stable compounds also showed reduced potency against ALK. Kinetic studies in NADPH-fortified and unfortified microsomes and plasma produced submicromolar Km values and could help explain the saturation of elimination observed in vivo. Predictions of CL based on kinetics from hydrolysis and NADPH-dependent pathways produced predicted hepatic CL values of 3.8, 3.0, 1.6, and 1.2 l/h⋅kg for compound 1, compound 2 [(E)-3,5-difluoro-N-(6-((4-(2-hydroxypropan-2-yl)piperidin-1-yl)methyl)-1-((1s,4s)-4-(isopropylcarbamoyl)cyclohexyl)-1H-benzo[d]imidazol-2(3H)-ylidene)benzamide], compound 3 [(E)-3-chloro-5-fluoro-N-(6-((4-(2-hydroxypropan-2-yl)piperidin-1-yl)methyl)-1-((1s,4s)-4-(isopropylcarbamoyl)cyclohexyl)-1H-benzo[d]imidazol-2(3H)-ylidene)benzamide], and compound 4 [(E)-N-(6-((4-(2-hydroxypropan-2-yl)piperidin-1-yl)methyl)-1-((1s,4s)-4-(isopropylcarbamoyl)cyclohexyl)-1H-benzo[d]imidazol-2(3H)-ylidene)-3-(trifluoromethyl)benzamide], respectively. The in vivo observed CLs for compounds 1, 2, 3, and 4 were 5.52, 3.51, 2.14, and 2.66 l/h⋅kg, respectively. These results indicate that in vitro metabolism kinetic data, incorporating contributions from both hydrolysis and NADPH-dependent metabolism, could be used to predict the systemic CL of compounds cleared via hydrolytic pathways provided that the in vitro assays thoroughly investigate the processes, including the contribution of other metabolic pathways and the possibility of saturation kinetics.
Mycobacterium tuberculosis RmlC epimerase (Rv3465): a promising drug-target structure in the rhamnose pathway.

The Mycobacterium tuberculosis rmlC gene encodes dTDP-4-­keto-6-deoxyglucose epimerase, the third enzyme in the M. tuberculosis dTDP-l-rhamnose pathway which is essential for mycobacterial cell-wall synthesis. Because it is structurally unique, highly substrate-specific and does not require a cofactor, RmlC is considered to be the most promising drug target in the pathway, and the M. tuberculosis rmlC gene was selected in the initial round of TB Structural Genomics Consortium targets for structure determination. The 1.7 A native structure determined by the consortium facilities is reported and implications for in silico screening of ligands for structure-guided drug design are discussed.
Increased alpha2 subunit-associated AMPK activity and PRKAG2 cardiomyopathy.

Background— AMP-activated protein kinase (AMPK) regulatory γ2 subunit (PRKAG2) mutations cause a human cardiomyopathy with cardiac hypertrophy, preexcitation, and glycogen deposition. PRKAG2 cardiomyopathy is recapitulated in transgenic mice overexpressing mutant PRKAG2 N488I in the heart (TGγ2N488I). AMPK is a heterotrimeric kinase consisting of 1 catalytic (α) and 2 regulatory (β and γ) subunits. Two α-subunit isoforms, α1 and α2, are expressed in the heart; however, the contribution of AMPK utilization of these subunits to PRKAG2 cardiomyopathy is unknown. Mice overexpressing a dominant-negative α2 subunit of AMPK (TGα2DN) provide a tool for selectively inhibiting α2, but not α1, subunit-associated AMPK activity. Methods and Results— In compound-heterozygous TGγ2N488I/TGα2DN mice, AMPK activity associated with α2 but not α1 was decreased compared with TGγ2N488I. The TGα2DN transgene reduced the disease phenotype of TGγ2N488I, partially or completely normalizing the ECG, cardiac function, cardiac morpho...
Cardiocerebral resuscitation: the new cardiopulmonary resuscitation.

Received August 4, 2004; revision received November 24, 2004; accepted December 10, 2004. “Why is it that every time I press on his chest he opens his eyes, and every time I stop to breathe for him he goes back to sleep?” 1 This article reviews research that shows that cardiopulmonary resuscitation (CPR) as it has been practiced and as it is presently taught and advocated is far from optimal. The International Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care , hereafter referred to as “Guidelines 2000,” were evidence based.2 During their formulation, the greatest weight of evidence was given to placebo-controlled randomized trials in humans. Unfortunately, it is extremely difficult not only to obtain informed consent but also to obtain funding for studies of the magnitude necessary to answer critically important CPR questions. It is unfortunate that controlled CPR research in animals was given the lowest priority in the evidence-based scheme.2 In our opinion, controlled animal experiments provide data that may be nearly impossible to obtain in human trials in which the circumstance, age, disease states, interventions, and response times to arrest are variable and often unknown. On the other hand, the use of swine for CPR research is not the perfect experimental solution, because they are easier to resuscitate in that they have no underlying heart disease (unless experimentally produced), they are younger, and they have more compliant chests than older adults with cardiac arrest. Since the formulation of “Guidelines 2000,” old and new research in animals and new research in humans have rendered them outdated. Although they will be revised, it is unknown when and what changes will be made. Nevertheless, in 2003, the CPR research information from both animal and humans was so compelling that we could not in good conscience wait for …
Dynamism of Stimuli-Responsive Nanohybrids: Environmental Implications

Nanomaterial science and design have shifted from generating single passive nanoparticles to more complex and adaptive multi-component nanohybrids. These adaptive nanohybrids (ANHs) are designed to simultaneously perform multiple functions, while actively responding to the surrounding environment. ANHs are engineered for use as drug delivery carriers, in tissue-engineered templates and scaffolds, adaptive clothing, smart surface coatings, electrical switches and in platforms for diversified functional applications. Such ANHs are composed of carbonaceous, metallic or polymeric materials with stimuli-responsive soft-layer coatings that enable them to perform such switchable functions. Since ANHs are engineered to dynamically transform under different exposure environments, evaluating their environmental behavior will likely require new approaches. Literature on polymer science has established a knowledge core on stimuli-responsive materials. However, translation of such knowledge to environmental health and safety (EHS) of these ANHs has not yet been realized. It is critical to investigate and categorize the potential hazards of ANHs, because exposure in an unintended or shifting environment could present uncertainty in EHS. This article presents a perspective on EHS evaluation of ANHs, proposes a principle to facilitate their identification for environmental evaluation, outlines a stimuli-based classification for ANHs and discusses emerging properties and dynamic aspects for systematic EHS evaluation.
Ecological Homogenization of Urban USA

A visually apparent but scientifically untested outcome of land-use change is homogenization across urban areas, where neighborhoods in different parts of the country have similar patterns of roads, residential lots, commercial areas, and aquatic features. We hypothesize that this homogenization extends to ecological structure and also to ecosystem functions such as carbon dynamics and microclimate, with continental-scale implications. Further, we suggest that understanding urban homogenization will provide the basis for understanding the impacts of urban land-use change from local to continental scales. Here, we show how multi-scale, multi-disciplinary datasets from six metropolitan areas that cover the major climatic regions of the US (Phoenix, AZ; Miami, FL; Baltimore, MD; Boston, MA; Minneapolis–St Paul, MN; and Los Angeles, CA) can be used to determine how household and neighborhood characteristics correlate with land-management practices, land-cover composition, and landscape structure and ecosystem functions at local, regional, and continental scales.
Quantitative myocardial perfusion in mice based on the signal intensity of flow sensitized CMR.

Background In the conventional approach to arterial spin labeling in the rodent heart, the relative difference in the apparent T1 relaxation times corresponding to selective and non-selective inversion is related to perfusion via a two compartment model of tissue. But accurate determination of T1 in small animal hearts is difficult and prone to errors due to long scan times and high heart rates. In this study we introduce the theoretical frame work for an alternative method (SI-method) based purely on the signal intensity of slice-select and non-select inversion recovery images at a single inversion time at short repetition time.
Enabling web users and developers to script accessibility with Accessmonkey

Efficient web access remains elusive for blind computer users. Previous efforts to improve web accessibility have focused on developer awareness, automated improvement, and legislation, but these approaches have left remaining concerns. First, while many tools can help produce accessible content, most are difficult to integrate into existing developer workflows and rarely offer specific suggestions that developers can implement. Second, tools that automatically improve web content for users generally solve specific problems and are difficult to combine and use on a diversity of existing assistive technology. Finally, although blind web users have proven adept at overcoming the shortcomings of the web and existing tools, they have been only marginally involved in improving the accessibility of their own web experience.In a step toward addressing these concerns, we have developed Accessmonkey, a common scripting framework that web users, web developers and web researchers can use to collaboratively improve ...
Convertibility verification and converter synthesis: two faces of the same coin

An essential problem in component-based design is how to compose components designed in isolation. Several approaches have been proposed for specifying component interfaces that capture behavioral aspects such as interaction protocols, and for verifying interface compatibility. Likewise, several approaches have been developed for synthesizing converters between incompatible protocols. In this paper, we introduce the notion of adaptability as the property that two interfaces have when they can be made compatible by communicating through a converter that meets specified requirements. We show that verifying adaptability and synthesizing an appropriate converter are two faces of the same coin: adaptability can be formalized and solved using a game-theoretic framework, and then the converter can be synthesized as a strategy that always wins the game. Finally we show that this framework can be related to the rectification problem in trace theory.
Presenting the Snowflake Video Imager (SVI)

Abstract Herein the authors introduce the Snowflake Video Imager (SVI), which is a new instrument for characterizing frozen precipitation. An SVI utilizes a video camera with sufficient frame rate, pixels, and shutter speed to record thousands of snowflake images. The camera housing and lighting produce little airflow distortion, so SVI data are quite representative of natural conditions, which is important for volumetric data products such as snowflake size distributions. Long-duration, unattended operation of an SVI is feasible because datalogging software provides data compression and the hardware can operate for months in harsh winter conditions. Details of SVI hardware and field operation are given. Snowflake size distributions (SSDs) from a storm near Boulder, Colorado, are computed. An SVI is an imaging system, so SVI data can be utilized to compute diverse data products for various applications. In this paper, the authors present visualizations of frozen particles (i.e., snowflake aggregates as we...
The Impact of Hospital Mergers on Treatment Intensity and Health Outcomes

Consolidation is a common response to financial and competitive pressures in many markets. The primary concern is often financial: will the merger increase prices? The health care sector involves additional complications. For example, both dimensions of demand for health care services are affected by third parties: treatments are prescribed by physicians while health insurance shields consumers from the full costs of care. Prices do not reflect their demand curve but are instead set by the insurer for public insurance plans or through negotiations between the insurer and providers in private insurance plans. Because of these factors, the implications of price changes on consumers may be more difficult to disentangle. Additionally, the quality of health care services is important for both survival and quality of life. Thus, the impact of consolidation in health care markets on nonprice dimensions, such as quality, may be at least as important as its impact on price. I define a hospital merger as the consolidation of two facilities into a single legal entity. The license-relinquishing facility becomes a satellite campus of the license-retaining facility and hospital boards and physician and nursing staffs are unified. Despite the intensity of this transaction, the average rate of hospital mergers doubled from 12 per year in the mid-1980s to 24 per year in the early 1990s (Bazzoli et al. 2002). Pressures along both price and quantity dimensions may have contributed to this wave of mergers. Average Medicare hospital prices fell initially with the institution of the Prospective Payment System in 1984 and again in 1988 with a strengthening in the requirements for elevated payments (Coulam and Gaumer 1991). The advent of managed care in the 1990s reduced hospital prices within the private insurance market (Cutler, McClellan, and Newhouse 2000; Dor, Grossman, and Koroukian 2004; Shen and Melnick 2006). This fall in average prices coincided with a reduction in demand for hospital services. Vogt and Town (2006) suggest that technological advances created an excess capacity through shifting many inpatient procedures to an outpatient setting and reducing length of stay for others. By creating a single legal entity, a merger enables capacity reduction through consolidating services between two facilities without being subject to state regulations (Dranove and Lindrooth 2003). Hospital mergers have the potential to affect quality of care through several mechanisms. If a merger creates financial benefits, the consolidated hospital may reinvest these gains into quality improvement. Likewise, service consolidation may increase procedure volume and consequently enhance care provision. However, reducing competition may reduce the incentive to improve quality to attract patients. Finally, the disruption caused by unifying two independent facilities may negatively affect quality, particularly in the immediate aftermath of the merger.
11.3: Temperature Effect on Polymer-stabilized Blue-phase LCDs

In this paper, temperature effects on polymer-stabilized blue-phase PSBP liquid crystal composites are analyzed. As the temperature increases, both Kerr constant and response time decrease rapidly. The proposed physical models fit well with experimental data. These results will provide valuable guidelines for optimizing PSBP material development and device performance.
Neuronal circuits that regulate feeding behavior and metabolism

Neurons within the central nervous system receive humoral and central (neurotransmitter or neuropeptide) signals that ultimately regulate ingestive behavior and metabolism. Recent advances in mouse genetics combined with neuroanatomical and electrophysiological techniques have contributed to a better understanding of these central mechanisms. This review integrates recently defined cellular mechanisms and neural circuits relevant to the regulation of feeding behavior, energy expenditure, and glucose homeostasis by metabolic signals.
Statistical management of data in clinical research.

We consider a number of prevalent problems in the design and analysis of clinical studies in dental caries and in periodontology: sample size determination, confidence intervals for important measures of treatment effectiveness, parametric vs. nonparametric methods, and the measurement of interexaminer agreement. The procedures we recommend are applicable to studies in either specialty. A problem that is unique to studies in periodontology, whether the appropriate unit of analysis is the patient or the periodontal pocket, is also considered.
Oat and rye overseeded into soybean as fall cover crops in the Upper Midwest

ABSTRACT: Oat, rye, and an oat-rye mixture were overseeded into soybean in August to determine the shoot dry matter and residue cover produced by these cover crops and their effect on subsequent soybean and corn yield. The oat cover crop reduced soybean yield in only one year and the other cover crops had no effect. Fall cover crop shoot dry matter averaged 440 kg ha−1 and did not differ among the three cover crops. Rye shoot dry matter measured in the spring averaged 1660 kg ha−1 for the rye and oat-rye mixture. Cover crops increased surface residue cover by 7 to 18% in some years. Corn yields were reduced following rye and oat-rye cover crops, but were not reduced by the oat cover crop. Oat overseeded into soybean is a viable cover crop system in Iowa and unlike rye, does not reduce yield of the following corn crop.
CORROSION MINERALOGY OF COMMON BIRD SHOT TYPES IN NORTH CAROLINA, USA, ENVIRONMENTS

This study compared corrosion of lead, steel, copper-coated lead, tungsten-steel, and bismuth varieties of shot in different sedimentary and aquatic environments in North Carolina. Sets of individual plastic vials containing all five types of shot were placed in the following environments: marine beach, marine dune/soil, barrier island lagoonal mud, saltwater, running (stream) freshwater above and below sediment surface, still (pond) freshwater above and below sediment surface, and forest soil and surface. After approximately 4.5 years exposure, samples were collected and analyzed with scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) and powder X-ray diffraction (XRD). Samples that were placed in saltwater environments were the most severely corroded, while those in terrestrial or freshwater environments were much less corroded. Similarly, buried samples were generally more corroded than samples placed at or above the water table. Analyses reveal the production of Pb oxide, hydroxide, chloride, carbonate, sulfide, and sulfate compounds in lead and copper-coated lead shot. Steel and tungsten-steel shot exhibited a surface layer of Fe oxides/hydroxides. Bismuth shot and tungsten-steel shot showed little corrosion, limited to small amounts of oxide/chloride and oxide only in two of the sampled environments. In all shot types, 19 minerals and one non-mineral compound [Zn 4 (CO 3 )(OH) 6 •H 2 O] were identified as corrosion products.
Validation of a Physiological Day Equation: Development of the Mexican Bean Beetle on Snap Beans and Soybeans

A physiological day equation proposed by Waddill et al. (1976) of the form PD = 1/24 {[.55(TMAX−TMIN)+TMIN]−THT+[.15(TMAX−TMIN)+TMIN]−THT} where TMAX = Maximum Temperature, TMIN = Minimum Temperature and THT = Developmental Threshold, predicted development of the larvae of the Mexican bean beetle, Epilachna varivestis Mulsant, on soybeans and snap beans with only ca. a 2% error. This sine curve based equation incorporates geographical location coefficients, and predictions were accurate enough for acceptable simulation limits, especially with fluctuating temperatures such as those that occur in the field. Predictions by the equation were improved when temperatures did not approach the physiological limits of beetle development. The total number of days required for larvae to mature on snap beans ( Phaseolus ) and soybeans was 16.5 and 23.5, respectively. Extension of Mexican bean beetle developmental time when soybeans were utilized as food may have serious implications when compiling biological data for computer simulations.
Interaction of Tetraalkylammonium+ and DNA

We are interested in the interactions of monovalent cations with duplex DNA as observed by capillary electrophoresis. Here we compare the interactions of Na+ and of tetraalkylammonium+ (TXA+) with a model hairpin oligonucleotide having the sequence GA5C4T5C. As the size of the monovalent cation increases, its association with the coil conformation is enhanced and its association with the hairpin conformation is diminished. These changes can be ascribed to the hydrophobic surface of TXA+, increasingly attracted to the hydrophobic coil conformation and increasingly rejected by the hydrophilic hairpin conformation. Thus TXA+ acts as a denaturant, markedly lowering the melting temperatures of duplex DNA.
Stimulating Students’ Use of External Representations for a Distance Education Time Machine Design

As faculty members in an instructional design and technology (IDT) program, we wanted to help our graduate students better understand and experience how designers design in the real world. We aimed to design a reflective and collaborative learning environment where we sparked students to engage in reflection, ideation, and the iterative process of problem-solving. For an assignment in a graduate IDT class, we piloted using Cacoo, an online diagramming and mapping tool, to provide and simulate an authentic learning environment to create external representations. For a distance education time machine design assignment, our pilot focused on the ways in which an external representation environment was used to stimulate students’ reflective conversations with design drafts. We share our pilot story by presenting the literature that grounded our pilot, a description of the participants and design assignment, our choice to use Cacoo, the design process, the design assessments, and the pilot’s significance and next steps.
Evans functions and bifurcations of nonlinear waves of some nonlinear reaction diffusion equations

Abstract The main purposes of this paper are to accomplish the existence, stability, instability and bifurcation of the nonlinear waves of the nonlinear system of reaction diffusion equations u t = u x x + α [ β H ( u − θ ) − u ] − w , w t = e ( u − γ w ) and to establish the existence, stability, instability and bifurcation of the nonlinear waves of the nonlinear scalar reaction diffusion equation u t = u x x + α [ β H ( u − θ ) − u ] , under different conditions on the model constants. To establish the bifurcation for the system, we will study the existence and instability of a standing pulse solution if 0 2 ( 1 + α γ ) θ α β γ ; the existence and stability of two standing wave fronts if 2 ( 1 + α γ ) θ = α β γ and γ 2 e > 1 ; the existence and instability of two standing wave fronts if 2 ( 1 + α γ ) θ = α β γ and 0 γ 2 e 1 ; the existence and instability of an upside down standing pulse solution if 0 ( 1 + α γ ) θ α β γ 2 ( 1 + α γ ) θ . To establish the bifurcation for the scalar equation, we will study the existence and stability of a traveling wave front as well as the existence and instability of a standing pulse solution if 0 2 θ β ; the existence and stability of two standing wave fronts if 2 θ = β ; the existence and stability of a traveling wave front as well as the existence and instability of an upside down standing pulse solution if 0 θ β 2 θ . By the way, we will also study the existence and stability of a traveling wave back of the nonlinear scalar reaction diffusion equation u t = u x x + α [ β H ( u − θ ) − u ] − w 0 , where w 0 = α ( β − 2 θ ) > 0 is a positive constant, if 0 2 θ β . To achieve the main goals, we will make complete use of the special structures of the model equations and we will construct Evans functions and apply them to study the eigenvalues and eigenfunctions of several eigenvalue problems associated with several linear differential operators. It turns out that a complex number λ 0 is an eigenvalue of the linear differential operator, if and only if λ 0 is a zero of the Evans function. The stability, instability and bifurcations of the nonlinear waves follow from the zeros of the Evans functions. A very important motivation to study the existence, stability, instability and bifurcations of the nonlinear waves is to study the existence and stability/instability of infinitely many fast/slow multiple traveling pulse solutions of the nonlinear system of reaction diffusion equations. The existence and stability of infinitely many fast multiple traveling pulse solutions are of great interests in mathematical neuroscience.
Reversed-phase liquid chromatography

Abstract Reversed-phase liquid chromatography encompasses a family of separation techniques characterized by the distribution of compounds between a water-containing mobile phase and a relatively nonselective stationary phase. As a consequence, for method development, variation of mobile-phase properties are more influential on retention and selectivity than the variation of stationary-phase properties. Empirical models provide useful relationships to predict changes in retention for variation in solvent strength and temperature. Quantitative structure-retention relationships facilitate the selection of separation conditions for mixtures of known composition. The heterogeneous nature of the solvated stationary phase has so far, however, frustrated the development of fundamental thermodynamic retention models. In their absence, linear free energy relationship models have been developed to facilitate a global understanding of chromatographic selectivity and its variation with experimental parameters and for the classification of stationary-phase selectivity for the separation of neutral low-mass compounds. These tools are invaluable for obtaining insight into the retention mechanism in reversed-phase liquid chromatography.
Methodological considerations in comparing access to Pre-emptive renal transplantation between SLE and other ESRD causes in the USRDS.

Abstract Background We compared pre-emptive transplant rates between SLE and non-SLE end-stage renal disease (ESRD) from the U.S. Renal Data System (USRDS) and investigated the potential influence of frequency matching and primary ESRD causes in the non-SLE group. Methods 4830 adult SLE patients with incident ESRD from USRDS 2005–2009 were frequency matched by age, sex and race to 4830 patients with incident non-SLE ESRD. Multivariable logistic regression models were used to estimate the odds of pre-emptive transplantation in SLE and non-SLE, and with the non-SLE subgroups by primary ESRD cause. Results The odds ratios (OR) of receiving a pre-emptive transplant were similar among non-SLE and SLE (referent group): OR = 1.18 (95% CI: 0.92, 1.50; p = 0.20). However, the ORs for receiving a pre-emptive transplant were 0.19 (95% CI: 0.08, 0.42) in type 2 diabetes ESRD, 0.42 (95% CI: 0.23, 0.75) for hypertension-associated ESRD, 1.67 (95% CI: 1.10, 2.54) in type 1 diabetes ESRD, and 2.06 (95% CI: 1.55, 2.73) for “other” ESRD. In contrast to non-SLE, younger SLE patients were less likely to receive a pre-emptive transplant than older SLE patients. Conclusion The results of this study provide compelling evidence that major improvements need to be made in optimizing access to pre-emptive transplantation in SLE by addressing sociodemographic disparities and the unique challenges faced by SLE patients. Applying careful matching and selecting appropriate comparison groups in future studies may facilitate the development of effective strategies to address these barriers and to increase the number of pre-emptive renal transplants among SLE patients.
Prices are right: managing resources and incentives in peer-assisted content distribution

We present a novel design for a peer-assisted content distribution system that addresses two key shortcomings of existing proposals. First, our system explicitly identifies the relative demand for files: users are rewarded for sharing more popular content. Second, our system efficiently utilizes network resources, by considering resource constraints explicitly when matching downloaders and uploaders. Underlying our system is a market-based mechanism that enables the efficient allocation of network resources across multiple files. Although we price files and employ a virtual currency, these are purely an algorithmic ploy: the system clients hide the market details from the user. Nevertheless, our design also naturally incentivizes the contribution of scarce resources. More importantly, our design endogenously adapts peers' behaviors to changing environments, a critical advantage for real-world deployments in which network conditions, participation rates, resource demands, and content are continually in flux.
Analyzing Writing Styles with Coh-Metrix.

Computer scientists, linguists, stylometricians, and cognitive scientists have successfully divided corpora into modes, domains, genres, registers, and authors. The limitations for these successes, however, often result from insufficient indices with which their corpora are analyzed. In this paper, we use Coh-Metrix, a computational tool that analyzes text on over 200 indices of cohesion and difficulty. We demonstrate how, with the benefit of statistical analysis, texts can be analyzed for subtle, yet meaningful differences. In this paper, we report evidence that authors within the same register can be computationally distinguished despite evidence that stylistic markers can also shift significantly over time.
Animal Models of Human Behavior

Other contributors to this volume have described intriguing evidence about possible biological substrata for attachment and affiliative behaviors. Such evidence suffers from being of necessity correlational. A statement of John Dobbing’s (1968) in reference to research on the behavioral effects of malnutrition is applicable here: Even the most sophisticated multifactorial analysis is no substitute for the experimental testing of hypotheses, and this can only be done with animals. It should be self-evident that experimental animal and human field studies must interdigitate if any conclusions are to be reached before the end of the present interglacial period. (p. 294)