cssi/SciSciGPT-SciSciNet huggingface dataset:
Integrating the active process of hair cells with cochlear function

The sensitivity, frequency resolution and dynamic range of hearing depend upon the cochlear active process, a mechanical-amplification system within the cochlea. In this Review, Hudspeth summarizes evidence that these features result from the operation of hair cells near a dynamical instability, the Hopf bifurcation. Uniquely among human senses, hearing is not simply a passive response to stimulation. Our auditory system is instead enhanced by an active process in cochlear hair cells that amplifies acoustic signals several hundred-fold, sharpens frequency selectivity and broadens the ear's dynamic range. Active motility of the mechanoreceptive hair bundles underlies the active process in amphibians and some reptiles; in mammals, this mechanism operates in conjunction with prestin-based somatic motility. Both individual hair bundles and the cochlea as a whole operate near a dynamical instability, the Hopf bifurcation, which accounts for the cardinal features of the active process.
Why math matters: A quick briefer in valuing securities

Many books have been written on how to value securities that trade in the financial markets. Most of them stress quantitative analysis. But unless you're a mathematician or computer programmer, says the author, you can get away with just understanding the concepts—and knowing which computer buttons to push to get the job done. © 2000 John Wiley & Sons, Inc.
Race and IQ: Molecular genetics as deus ex machina.

During the last hundred years, the debate over the meaning of race has retained a highly consistent core, despite evolution of the technical details. Non-Europeans, and in particular, Africans, are assigned the role of deviants and outcasts, whose claim on our common humanity remains in doubt. Each time the technical facade of these racialist arguments is destroyed, the latest jargon and half-truths from the margins of science are used to rebuild them around the same core belief in Black inferiority. Because race is in part a genetic concept, the advent of molecular DNA technology has opened an important new chapter in this story. Unfortunately, the article by D. Rowe (2005, this issue) begins from mistaken premises and merely restates the racialist view using the terminology of molecular genetics. No technology-even the awe-inspiring tools now available to DNA science-can overcome the handicap of fundamental conceptual errors. Race is not a concept that emerged from within modern genetics; rather, it was imposed by history, and its meaning is inseparable from that cultural origin. By ignoring its cultural meaning the reductionist narrative about race fails-both in the narrow terms of science and as a contribution to the broader social discourse.
Kinetic Modelling of the Deposition of SiC from Methyltrichlorosilane

A kinetic model is presented for the deposition of silicon carbide through decomposition of methyltrichlorosilane (MTS). The developed model includes gas phase (homogeneous) reactions that lead to formation of deposition precursors and surface (heterogeneous) reactions that lead or can lead to deposition of silicon carbide, silicon, and carbon. The kinetic model is incorporated in a transport and reaction model for a tubular hot-wall reactor, and the overall reactor model is used to obtain some preliminary results on the effects of pressure and distance in the reactor on the rate of deposition and the composition of the deposit. The results show that the model can reproduce most of the experimental observations of the literature.
The King and Hayden Surveys Overlap of pioneering mapping in northern Colorado

Mapping by two of the great post-Civil War geological surveys of the American West overlapped in several areas, including a strip across northern Colorado [King and Hayden Surveys]. Prior to the publication of atlases [King–1876, Hayden–1877] geologists of these surveys exchanged little information, yet their final maps in areas of overlap are fairly similar. King9s construction of topographical maps to serve as the basis for portraying geology was adopted by the other surveys. While the degree of detail shown and age interpretation of some stratigraphic units vary between the maps, overall geologic trends are similar. In 1878, King justified his survey expenses, writing that: “This exploration has not duplicated other surveys made by authority of Congress.” While overlap of map areas in part reflects varied goals of survey leaders and/or imprecisely defined survey and territorial boundaries, it also reflects the strong personalities and rivalry among these men and their unwillingness to share information. This set the stage for the consolidation of western surveys under the authority of a single agency, the newly formed U. S. Geological Survey with Clarence King as its first director.
Morphological, behavioural and biological studies of Melanagromyza obtusa (Malloch) (Diptera: Agromyzidae) on Cajanus indicus Spreng1

This paper deals with the behaviour and biology of Melanagromyza obtusa (Malloch) a serious pest of Cajanus indicus Spreng, one of the staple pulse crops of Northern India. In addition to brief morphological descriptions of various instars a key for their identification is given. The incubation period has been found to vary between 51.9 to 60.0 hrs. Average duration of the 1st instar was found to be 37.3 hrs, while total larval duration was found to be 142.6 hrs. Pupal duration at controlled conditions (29°C and 86–90% RH) was 186.7 hrs while at normal laboratory conditions it was 224.4 hrs. Copulation was observed between 8.00 am and 4.00 pm, usually a day after emergence while a single pair copulated even after 30 days of emergence. Duration of copulation varied between 45 mts to 2 hrs 55 mts. 40.7% pods were infested during January while 12.2 % of seeds were infested during peak Zusammenfassung Studien zur Morphologie, Lebens- und Verhaltensweise von Melanagromyza obtusa (Malloch) (Dipt.: Agromyzidae) an Cajanus indicus Spreng Die Arbeit berichtet uber die Samenfliege M. obtusa, einem bedeutenden Schadling der Haupthulsenfrucht Nordindiens, Cajanus indicus. Zunachst werden die auβeren Merkmale der verschiedenen Entwicklungsstadien beschrieben und ein Schlussel zu ihrer Bestimmung gegeben. Die Embryonal-Entwicklung dauerte 52–60 Stunden. Die mittlere Entwicklungsdauer der Erstlarven betrug 37,3 Stunden, die gesamte Larvenzeit 142,6 Stunden. Die Puppe entwickelte sich bei 29° V in 186,7, unter normalen Laborbedingungen erst in 334,8 Stunden. Die Kopulation wurde zwischen 8 und 16 Uhr beobachtet, in der Regel am Tage nach dem Schlupfen. 40,7% der Hulsen waren wahrend des Januars befallen, dagegen nur 12,2% der Samen. Ein gesunder Samen wog i. M. 0,077 g, ein befallener 0,024 g. Der Befall war besonders hoch (63,7%) an schattigen Stellen. Als Parasiten traten uberwiegend Chalcididen mit einer Maximalparasitierung von 20% auf.
A Mutation in the Escherichia coliF0F1-ATP Synthase Rotor, γE208K, Perturbs Conformational Coupling between Transport and Catalysis

Cross-linking studies on the Escherichia coli F0F1-ATP synthase indicated a site of interaction involving γ and e subunits in F1 and subunit c in F0 (Watts, S. D., Tang, C., and Capaldi, R. A. (1996) J. Biol. Chem. 271, 28341–28347). To assess the function of these interactions, we introduced random mutations in this region of the γ subunit (γ194–213). One mutation, γGlu-208 to Lys (γE208K), caused a temperature-sensitive defect in oxidative phosphorylation-dependent growth. ATP hydrolytic rates of the γE208K F0F1 enzyme became increasingly uncoupled from H+ pumping above 28 °C. In contrast, Arrhenius plot of steady-state ATP hydrolysis of the mutant enzyme was linear from 20 to 50 °C. Analysis of this plot revealed a significant increase in the activation energy of the catalytic transition state to a value very similar to soluble, e subunit-inhibited F1 and suggested that the mutation blocked normal release of e inhibition of ATP hydrolytic activity upon binding of F1 to F0. The difference in temperature dependence suggested that the γE208K mutation perturbed release of inhibition via a different mechanism than it did energy coupling. Suppressor mutations in the polar loop of subunitc restored ATP-dependent H+ pumping and transition state thermodynamic parameters close to wild-type values indicating that interactions between γ and c subunits mediate release of e inhibition and communication of coupling information.
The Scientist's World

This paper describes the features of the world of science, and it compares that world briefly with that of politics and the law. It also discusses some “postmodern” trends in philosophy and sociology that have been undermining confidence in the objectivity of science and thus have contributed indirectly to public mistrust. The paper includes broader implications of interactions of government and science.
Supply capacity acquisition and allocation with uncertain customer demands

We study a class of capacity acquisition and assignment problems with stochastic customer demands often found in operations planning contexts. In this setting, a supplier utilizes a set of distinct facilities to satisfy the demands of different customers or markets. Our model simultaneously assigns customers to each facility and determines the best capacity level to operate or install at each facility. We propose a branch-and-price solution approach for this new class of stochastic assignment and capacity planning problems. For problem instances in which capacity levels must fall between some pre-specified limits, we offer a tailored solution approach that reduces solution time by nearly 80% over an alternative approach using a combination of commercial nonlinear optimization solvers. We have also developed a heuristic solution approach that consistently provides optimal or near-optimal solutions, where solutions within 0.01% of optimality are found on average without requiring a nonlinear optimization solver.
Curricular reform of the 4th year of medical school: the colleges model.

Background: The practice of medicine has changed dramatically over the last 3 decades. Medical education has struggled to keep up with these changes, with only limited success. The 4th year of medical school offers a tremendous opportunity for curricular innovation, but little change has occurred in the past 30 years. Description: This article traces the history of the 4th year, from the Flexnerian era in which the classic preclinical-clinical model for medical education was developed, through the 1970s, when virtually every medical school adopted a largely elective 4th year, to the present. Although the classic 4th-year curriculum has a number of strengths such as flexibility and relative autonomy of scheduling for students, it also has significant weaknesses. Evaluation: A major educational initiative for the 4th year-the "College Phase"-has been implemented at the David Geffen School of Medicine at UCLA. It is designed to remedy many of the weaknesses of the 4th-year curriculum while preserving the ben...
A proposed structure for the 330 -nm chromophore of glutamate decarboxylase and other pyridoxal 5'-phosphate dependent enzymes.

Abstract 1. 1. Pyridoxal 5′-phosphate reacts with 1,3-diaminopropane to form a cyclic aldamine structure, rather than a Schiff base. The structure of this compound was proved by direct spectral study and by analogy with the reaction of the coenzyme with n -butylamine and the reactions of pyridine-4-aldehyde with n -butylamine and with 1,3-diaminopropane. 2. 2. Evidence is presented which suggests that the 330 nm chromophore of glutamate decarboxylase is an aldamine formed by addition of a second amino group to the carbon nitrogen double bond, rather than any other sort of aldamine or a normal Schiff base structure.
Retention of choice behavior in rats following mammillothalamic tractotomy

In Experiment 1 mammillothalamic tract (MTT) lesions in rat produced no change in the performance of a preoperatively acquired contingent (successive) brightness discrimination motivated by hunger. Freezing, assessed in an unavoidable shock situation, and passive avoidance were also unaffected. In Experiment 2 comparable MTT lesions produced significant (p < 0.03) decrements in retention of shock avoidance behavior, yet had no effect on choice behavior once the rat started running. Thus, it appears that the effect of mammillothalamic tractotomy on avoidance behavior is not attributable to a direct increase in freezing or to a loss in the retention of the ability to make difficult discriminations per se.
Interactions between gene products involved in divalent cation transport in Saccharomyces cerevisiae

The COT1 and ZRC1 genes of Saccharomyces cerevisiae are structurally related dosage-dependent suppressors of metal toxicity. COT1 confers increased tolerance to high levels of cobalt; ZRC1 confers increased tolerance to high levels of zinc. The two genes are not linked and have been mapped; COT1 to chromosome XV and ZRC1 to chromosome XIII. Phenotypes related to metal homeostasis have been examined in strains with varied COT1 and ZRC1 gene doses. Overexpression of COT1 confers tolerance to moderately toxic levels of zinc and ZRC1 confers tolerance to moderately toxic levels of cobalt. Strains that carry null alleles at both loci are viable. The metal-hypersensitive phenotypes of mutations in either gene are largely unaffected by changes in dosage of the other. COT1 and ZRCI function independently in conferring tolerance to their respective metals, yet the uptake of cobalt ions by yeast cells is dependent on the gene dosage of ZRC1 as well as of COT1 Strains that overexpress ZRC1 have increased uptake of cobalt ions, while ZRCI null mutants exhibit decreased cobalt uptake. The defects in cobalt uptake due to mutations at COT1 and ZRC1 are additive, suggesting that the two genes are responsible for the majority of cobalt and zinc uptake in yeast cells. The function of either gene product seems to be more important in metal homeostasis than is the GRR1 gene product, which is also involved in metal metabolism. Mutations in the GRR1 gene have no effect on the cobalt-related phenotypes of strains that have altered gene dosage of either COT1 or ZRC1.
The xanthones of a Halenia species

Abstract Extracts of a Colombian species of Halenia (Gentianaceae) yielded three xanthones, 1-hydroxy-2,3,4,7-tetramethoxy-, 1-hydroxy-2,3,4,5-tetramethoxy-, and 1-hydroxy-2,3,5-tetramethoxyxanthone, which have also been found to be the major xanthones of Frasera caroliniensis
QQ separations in type B band envelopes of asymmetric top molecules

Abstract Unresolved type B infrared bands of asymmetric top molecules often exhibit PQQR structure. A formula for the separation of the Q branches has been developed to fit measured values as reported in the literature and also the synthetic contours calculated by B adger and Z umwalt and by U eda and S himanouchi : Δv(QQ) = p(O.93 − 0.63 |K|1.3)[(A + B + C)T] 1 2 , where A, B and C are the rotational constants in cm−1, p = (A — C)/B, and K = (2B — A — C)/ (A — C). Agreement with observed separations is quite satisfactory for molecules with asymmetry parameters in the range −1
Golgi complex fragmentation in G2/M transition: An organelle‐based cell‐cycle checkpoint

In mammalian cells, the Golgi complex is organized into a continuous membranous system known as the Golgi ribbon, which is formed by individual Golgi stacks that are laterally connected by tubular bridges. During mitosis, the Golgi ribbon undergoes extensive fragmentation through a multistage process that is required for its correct partitioning into the daughter cells. Importantly, inhibition of this Golgi disassembly results in cell-cycle arrest at the G2 stage, suggesting that accurate inheritance of the Golgi complex is monitored by a "Golgi mitotic checkpoint." Here, we discuss the mechanisms and regulation of the Golgi ribbon breakdown and briefly comment on how Golgi partitioning may inhibit G2/M transition.
Political, Economic, and Social Consequences of Foreign Military Intervention:

Foreign military intervention is one of the most common types of interstate military force used over recent decades. As war’s costliness increases and the efficacy of economic sanctions and other foreign policy tools is increasingly questioned, it may become even more prevalent. Unfortunately, the field of international relations has little systematic understanding of the types of impacts such military ventures can have on target states in the developing world. In PCSE AR1 regressions of 106 developing countries from 1960 to 2002, we find that large scale foreign military interventions, which have over 1000 intervening troops, do not leave a significant imprint on governing institutions, economic growth rates, or physical quality of life in developing democracies. The same cannot be said for non-democratic states in the developing world. Hostile interventions can help to democratize non-democratic targets, while rival interventions lay the groundwork for long-term economic growth.
Performance envelope and reliability assessment of the NGST HEC cryocooler

The Northrup Grumman Space Technologies High Efficiency Cryocooler (NGST HEC) was designed to support a 10 Watt cooling load at 95 Kelvin while rejecting heat to an effective sink interface temperature of 300 Kelvin. This design is an example of the pulse tube with inertance tube variant of the Stirling thermodynamic cycle whose compressor section uses dual opposed pistons to minimize vibration imparted to any cooling load through the cold end. The Air Force Research Laboratory has characterized the extended performance envelope of this refrigeration system, including its off nominal design point performance and efficiency, its response to transient loading and rejection temperatures, and its cool down performance from ambient. In order to assess this system's long term ability to support extended continuous duty space missions, this cryocooler has been running continuously for over two years, as part of a five year study on whether significant degradation in performance can be measured over that time. Finally, comparison of this cryocooler to other similar space qualifiable refrigeration systems has been made.
Virulence of Pythium species isolated from wheat fields in eastern Washington

Although Pythium root rot in wheat (Triticum aestivum) is well documented, limited information is available concerning which species of Pythium are most responsible for disease damage. The objective of this study was to examine the variation in virulence on wheat among isolates of Pythium collected from cereal grain fields in eastern Washington. Isolates of nine Pythium species were tested for virulence on spring wheat cultivars Chinese Spring and Spillman. Cultivars were planted in pasteurized soil infested with Pythium isolates and placed in a growth chamber maintained at a constant 16°C and ambient humidity. Plant height, length of the first true leaf, and number of seminal roots were recorded, and roots were digitally scanned to create computer files that were analyzed using WinRhizo software. Pythium isolates caused a significant reduction (P < 0.05) in the number of root tips, root length, and length of the first leaf. Differences in virulence were detected among species and among isolates within species. Isolate Pythium debaryanum 90136 and P. ultimum 90038 were the most virulent and may prove useful in future disease screening assays of Triticum germ plasm.
Comparative Effectiveness of Noninvasive Ventilation vs Invasive Mechanical Ventilation in Chronic Obstructive Pulmonary Disease Patients With Acute Respiratory Failure

BACKGROUND Limited evidence exists on the comparative effectiveness of noninvasive ventilation (NIV) vs invasive mechanical ventilation (IMV) in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients with respiratory failure. OBJECTIVES To characterize the use of NIV and IMV, and to compare the effectiveness of NIV vs IMV in AECOPD. DESIGN AND PATIENTS Retrospective cohort study using data from the 2006–2008 Nationwide Emergency Department Sample. Emergency department visits for AECOPD with acute respiratory failure were identified with codes from the International Classification of Diseases, Ninth Revision, Clinical Modification. MEASURES The outcome measures were inpatient mortality, hospital length of stay, hospital charges, and complications. RESULTS There were an estimated 101,000 visits annually for AECOPD with acute respiratory failure; 96% were admitted to the hospital. Of these, NIV use increased from 14% in 2006 to 16% in 2008 (P=0.049). Use of NIV, however, varied widely between hospitals, ranging from 0% to 100% with a median of 11%. Noninvasive ventilation was more often used in higher–case volume, Northeastern hospitals. In a propensity score analysis, NIV use, compared with IMV, was associated with lower inpatient mortality (risk ratio: 0.54, 95% confidence interval [CI]: 0.50-0.59), shortened hospital length of stay (−3.2 days; 95% CI: −3.4 to −2.9 days), lower hospital charges (−$35,012; 95% CI: −$36,848 to −$33,176), and lower risk of iatrogenic pneumothorax (0.05% vs 0.5%, P<0.001). CONCLUSIONS Although NIV use is increasing in US hospitals, its adoption remains low and varies widely between hospitals. Our observational study suggests NIV appears to be more effective and safer than IMV for AECOPD in the real-world setting. Journal of Hospital Medicine 2013;8:165–172. © 2013 Society of Hospital Medicine
Terminator 24: Or, How to Philosophize with a Hammer!

Double Theatre. 1995. 37 minutes, color. video by David and Paul. For more information, contact The Resorcerer's Apprentice, P.O. Box 1226, Middlebury, VT 05753.
Comparison of amiodarone versus ibutilide for the prevention of immediate recurrences of atrial fibrillation during pulmonary vein isolation.

During segmental ostial ablation for pulmonary vein isolation, pulmonary vein potentials are easily identified during sinus rhythm or left atrial pacing. Therefore, maintenance of atrial fibrillation (AF) during the procedure is desirable. However, cardioversion is occasionally followed by an immediate recurrence of AF. This study compared the efficacy of ibutilide and amiodarone in preventing immediate recurrences of AF in patients who underwent pulmonary vein isolation. The subjects of this study were 25 patients (mean age 56 ± 10 years) who underwent pulmonary vein isolation for AF who had an immediate recurrence of AF within 60 seconds after 2 transthoracic cardioversions. The patients were randomized to receive an infusion of either 300 mg of amiodarone over 10 minutes or 1 mg of ibutilide over 5 minutes. Cardioversion was repeated 15 minutes after the drug infusion. If immediate recurrences of AF occurred 2 more times, the alternative study drug was administered, and cardioversion was repeated. Immediate recurrences of AF were suppressed by amiodarone in 8 of 10 patients (80%), and by ibutilide in 9 of 15 patients (60%, p = 0.4). After crossover, immediate recurrence of AF was suppressed in 2 of 6 patients (33%) by amiodarone, and in 1 of 2 patients (50%) by ibutilide (p = 0.6). Ibutilide and amiodarone, when used alone or in combination, prevented immediate recurrences of AF in 20 of 25 patients (80%). There were no adverse drug effects. Ibutilide and amiodarone were equally effective in suppressing immediate recurrences of AF. Overall, immediate recurrences of AF can be prevented by amiodarone and/or ibutilide in 80% of patients.
Energy-Efficient GHz-Class Charge-Recovery Logic

In this paper, we present Boost Logic, a charge- recovery circuit family that can operate efficiently at clock frequencies in excess of 1 GHz. To achieve high energy efficiency, Boost Logic relies on a combination of aggressive voltage scaling, gate overdrive, and charge-recovery techniques. In post-layout simulations of 16-bit multipliers with a 0.13-mum CMOS process at 1GHz, a Boost Logic implementation achieves 5 times higher energy efficiency than its minimum-energy pipelined, voltage-scaled, static CMOS counterpart at the expense of 3 times longer latency. In a fully integrated test chip implemented using a 0.13-mum bulk silicon process and on-chip inductors, chains of Boost Logic gates operate at clock frequencies up to 1.3 GHz with a 1.5-V supply. When resonating at 850 MHz with a 1.2-V supply, the Boost Logic test chip achieves 60% charge-recovery
Random sampling for histogram construction: how much is enough?

Random sampling is a standard technique for constructing (approximate) histograms for query optimization. However, any real implementation in commercial products requires solving the hard problem of determining “How much sampling is enough?” We address this critical question in the context of equi-height histograms used in many commercial products, including Microsoft SQL Server. We introduce a conservative error metric capturing the intuition that for an approximate histogram to have low error, the error must be small in all regions of the histogram. We then present a result establishing an optimal bound on the amount of sampling required for pre-specified error bounds. We also describe an adaptive page sampling algorithm which achieves greater efficiency by using all values in a sampled page but adjusts the amount of sampling depending on clustering of values in pages. Next, we establish that the problem of estimating the number of distinct values is provably difficult, but propose a new error metric which has a reliable estimator and can still be exploited by query optimizers to influence the choice of execution plans. The algorithm for histogram construction was prototyped on Microsoft SQL Server 7.0 and we present experimental results showing that the adaptive algorithm accurately approximates the true histogram over different data distributions.
Uniform Consensus among Self-driven Particles

A nonconservative stability theory for switched linear systems is applied to the convergence analysis of consensus algorithms in the discrete-time domain. It is shown that the uniform-joint-connectedness condition for asymptotic consensus in distributed asynchronous algorithms and multi-particle models is in fact necessary and sufficient for uniform exponential consensus.
Unraveling the role of high mobility group box protein 1 in severe trauma

High mobility group box protein 1 (HMGB1) has been shown to participate in acute inflammatory reactions, including acute lung injury and sepsis. There is also evidence that circulating levels of HMGB1 are increased after severe trauma and are associated with clinically important outcome parameters, including mortality. Recent studies demonstrated that HMGB1 itself has little or no proinflammatory activity, but is able to potentiate inflammatory responses through binding to mediators, such as endotoxin or cytokines. Important questions are to determine the binding partners for HMGB1 in the setting of severe injury and whether inhibition of interactions of HMGB1 and associated molecules with the cell surface can affect outcome after trauma.
The w-reciprocity rule

Abstract Given a small number of choices, a matrix is a convenient way to represent a fuzzy preference relation. Usually, this matrix is reciprocal. The w-reciprocity rule is presented here as a way to relax the rigidity of the reciprocal assumption and to embody linguistic meanings for indifference and for the representation of the converse preference.
Application of Active Noise Control for Reducing Snore

This paper presents an application of active noise control (ANC) for reducing snoring noise. The proposed snore ANC system can be installed on a traditional headboard, thus has potential benefits in retrofit, convenience, and is unobtrusive. Six snore ANC structures were developed using three different filtered-x least mean square (FXLMS) algorithms to achieve better performance with lower computational complexity and overall system cost. Real-time experiments using a twin-size headboard and snore samples show a reasonable size of quiet zone with satisfactory performance achieved with a low-cost ANC system
N-nitroamines of Agaricus silvaticus

Abstract β-Nitraminoalanine and its decarboxylation product N-nitroethylenediamine were identified in Agaricus silvaticus.
3D fluorescent particle tracking with nanometer scale accuracies using a double-helix point spread function

We demonstrate parallel three-dimensional (3D) tracking of multiple fluorescent microspheres with nanometer scale accuracies by engineering the 3D point spread function of a wide-field microscope to present a double-helix along the optical axis.
Effects of patient size on radiation dose reduction and image quality in low-kVp CT pulmonary angiography performed with reduced IV contrast dose.

The purpose of the study is to evaluate image quality and radiation exposure as a function of patient size for CT pulmonary angiography (CTPA) performed at reduced tube voltage and reduced intravenous (IV) contrast dose. We reviewed consecutive CTPAs performed between 9/1/2010 and 10/31/2010 on a 128-slice Siemens AS+ scanner using automated tube current modulation with quality reference mAs 200 and IV contrast concentration 370 mg I/ml followed by a saline flush: 99 scans at 120 kVp using 75 ml of contrast at 5 ml/s and 53 scans on patients lighter than 175 lbs at 100 kVp using 50 ml of contrast at 4 ml/s. We measured patient size (mean water-equivalent diameter) using a topogram analysis tool, signal (mean CT density) and noise (standard deviation) in the main pulmonary artery (MPA) on axial images, and calculated local CTDIvol from the kVp and mAs. Linear regression models were created for dependent variables ln(CTDIvol), signal, noise, and signal to noise ratio (SNR) as a function of independent variables size, age, gender, and kVp. After controlling for other variables, scanning at 100 kVp yielded CTDIvol reduction of 33 % (p < 0.0001), signal increase of 96 HU (p < 0.0001), and increased image noise (p < 0.0001), but without significant difference in SNR (p = 0.99). Relative to 120 kVp, 100-kVp CTPA allows simultaneous reduction of radiation exposure by 33 % and IV contrast dose by 33 % while maintaining image quality. Scanning at 100 kVp is recommended in all patients for whom the required mAs does not exceed maximum X-ray tube output.
Delay guarantee of virtual clock server

In a packet switching network, each communication channel is statistically shared among many traffic flows that belong to different end-to-end sessions. We present and prove a delay guarantee for the virtual clock service discipline (inspired by time division multiplexing). The guarantee has several desirable properties, including the following firewall property: the guarantee to a flow is unaffected by the behavior of other flows sharing the same server. There is no assumption that sources are flow controlled or well behaved. We first introduce and define the concept of an active flow. The delay guarantee is then formally stated as a theorem. We show how to obtain delay bounds from the delay guarantee of a single server for different specifications.
Pressure dependent reactions for atmospheric and combustion models

In order to characterize reactions as functions of temperature, pressure (molecular density) and the nature of the species that constitute that molecular density, master equation solutions are required. In this tutorial review, the application of the Multiwell suite of codes to some reactions of interest in atmospheric and combustion chemistry is discussed, with attention given to the details of the molecular and energy transfer values. Uncertainties in data and in structural and energetic molecular parameters combine to assure the need for optimization and collaborative processing 1,2 of the entire data base when modeling practical systems.
Cardiorespiratory fitness and physical activity in youth with type 2 diabetes.

Objective: The increased incidence of type 2 diabetes (T2D) among youth is hypothesized to be due, in part, to low levels of fitness and activity. Therefore, the purpose of this investigation was to examine whether cardiorespiratory fitness and physical activity are reduced in youth with T2D compared with overweight controls. Participants: Thirteen adolescent boys with previously diagnosed T2D (mean duration 2.4 ± 1.8 yr) were matched for age and body mass index to 13 overweight, non-diabetic controls. Methods: Cardiorespiratory fitness was assessed during a progressive exercise test to volitional fatigue and physical activity was estimated from a 7-d physical activity recall. Results: Youth with T2D reported performing ∼60% less moderate to vigorous physical activity compared with their non-diabetic counterparts (0.6 ± 0.2 vs. 1.4 ± 0.3 h/d, p = 0.04). Furthermore, diabetic youth exhibited significantly lower cardiorespiratory fitness levels compared with controls (28.7 ± 1.6 vs. 34.6 ± 2.2 mL/kg/min, p < 0.05). Conclusions: These findings support the hypothesis that cardiorespiratory fitness and physical activity are reduced in youth with T2D. Whether reduced fitness and activity contributed to the pathophysiology of the disorder cannot be determined from the cross-sectional analysis. Longitudinal studies are warranted to examine whether improvements in fitness and increased physical activity can prevent the development of T2D in high-risk youth.
Studying the use of popular destinations to enhance web search interaction

We present a novel Web search interaction feature which, for a given query, provides links to websites frequently visited by other users with similar information needs. These popular destinations complement traditional search results, allowing direct navigation to authoritative resources for the query topic. Destinations are identified using the history of search and browsing behavior of many users over an extended time period, whose collective behavior provides a basis for computing source authority. We describe a user study which compared the suggestion of destinations with the previously proposed suggestion of related queries, as well as with traditional, unaided Web search. Results show that search enhanced by destination suggestions outperforms other systems for exploratory tasks, with best performance obtained from mining past user behavior at query-level granularity.
Developing caring relationships in schools: a review of the research on caring and nurturing pedagogies

Education has been criticized for a disproportionate focus on the technical aspects of teaching with less focus on its ‘human’ aspects. Consequently, many researchers and theorists have expressed a need to answer what role care plays in education. Our purpose in this review is to examine the definition of caring pedagogies and synthesize relevant research helpful to understanding its application. We briefly consider moral development and ethical care theories pertinent to teaching and learning and synthesize the research findings related to defining and measuring caring pedagogy; as well as developing caring characteristics in teachers and students, caring classroom communities, and caring in unique and challenging contexts. Finally, we argue for more research on developing valid instruments for measuring caring pedagogy and examining under-explored contexts such as higher education and technology-mediated learning. We conclude that caring pedagogy provides a powerful means to student learning improvement, one meriting the greatest attention by educators and education researchers.
Experiences in teaching an educational user-level operating systems implementation project

The importance of a comprehensive implementation component for undergraduate Operating Systems (OS) courses cannot be understated. Students not only develop deep insight and understanding of OS fundamentals, but they also learn key software engineering skills that only a large development project, such as implementing an OS, can teach. There are clear benefits to traditional OS projects where students program or alter real (Linux) kernel source or extend educational OS implementations; however, in our experience, bootstrapping such a project is a huge undertaking that may not be accessible in many classrooms. In this paper, we describe a different approach to the OS implementation assignment: A user-level Operating System simulation based on UNIX preemptive signaling and threading constructs called ucontext. We believe that this variation of the implementation assignment provides many of the same educational benefits as traditional low-level projects without many of the expensive start-up costs. This project has been taught for a number of years at the University of Pennsylvania and was recently overhauled for the Fall 2011 semester. This paper describes the current version of the project and our experiences teaching it to a class of 54 students.
Leading from behind: democratic consolidation and the chieftaincy in South Africa

Despite the dramatic changes that have occurred in South Africa over the last fifteen years, the chieftaincy remains an important political institution that continues to exercise authority. It has not only been given official recognition and protection in the constitution, but has attempted to become more involved in activities such as development, local government, and elections. How this institution might affect the process of democratic consolidation, however, has failed to generate much research. This article explores the ways in which the chieftaincy has responded to the introduction of democratic electoral practices at the local level. While the chieftaincy has not been immune from the social and political changes that have swept through the country since the transition, it has nonetheless sought to direct, or redirect, these changes in ways that bolster its own authority. Many local communities expect the chieftaincy not only to assist with the formal electoral process, but also to allow for more participation within local level chieftaincy institutions. A close examination of chieftaincy-societal relations demonstrates that while the chieftaincy has been affected by new democratic rules and practices, it has also influenced how local communities practice and understand these same rules and practices. This mutually transformative process illustrates the complexity of democratic consolidation, as well as the ability of the chieftaincy to adapt to changing political and social environments without sacrificing its unique claims to authority.
Food Labeling for Restaurants Fact versus Fiction

Abstract Stringent food-labeling regulations control the use of nutrition-related information in describing menu items. The net result for restaurateurs may be that they give no nutrition information at all.
Pulmonary Chemokine Expression Is Coordinately Regulated by STAT1, STAT6, and IFN-γ

The expression of distinct chemokines within the asthmatic lung suggests that specific regulatory mechanisms may mediate various stages of asthmatic disease. Global transcript expression profiling was used to define the spectrum and kinetics of chemokine involvement in an experimental murine model of asthma. Seventeen chemokines were induced in the lungs of allergen-inoculated mice, as compared with saline-treated mice. Two (CXCL13 and CCL9) of the 17 identified chemokines have not previously been associated with allergic airway disease. Seven (7 of 17; CCL2, CCL7, CCL9, CCL11, CXCL1, CXCL5, CXCL10) of the allergen-induced chemokines were induced early after allergen challenge and remained induced throughout the experimental period. Three chemokines (CXCL2, CCL3, and CCL17) were induced only during the early phase of the inflammatory response after the initial allergen challenge, while seven chemokines (CCL6, CCL8, CCL12, CCL22, CXCL9, CXCL12, and CXCL13) were increased only after a second allergen exposure. Unexpectedly, expression of only three chemokines, CCL11, CCL17, and CCL22, was STAT6 dependent, and many of the identified chemokines were overexpressed in STAT6-deficient mice, providing an explanation for the enhanced neutrophilic inflammation seen in these mice. Notably, IFN-gamma and STAT1 were shown to contribute to the induction of two STAT6-independent chemokines, CXCL9 and CXCL10. Taken together, these results show that only a select panel of chemokines (those targeting Th2 cells and eosinophils) is positively regulated by STAT6; instead, many of the allergen-induced chemokines are negatively regulated by STAT6. Collectively, we demonstrate that allergen-induced inflammation involves coordinate regulation by STAT1, STAT6, and IFN-gamma.
Reliability of a field-based drop vertical jump screening test for ACL injury risk assessment

Objectives: There is an epidemic of anterior cruciate ligament (ACL) injuries in youth athletes. Poor neuromuscular control is an easily modifiable risk factor for ACL injury, and can be screened f...
Introduction to the Symposium on Empirical and Experimental Methods in Law

In April, 2001, the University of Illinois College of Law hosted a symposium on empirical and experimental methods in legal scholarship. This introduction explains that the organizers deemed the symposium to be timely in that there has been a significant increase in the volume and importance of empirical work related to legal topics and the first tentative steps in applying experimental methods to the study of law. The authors of this introduction elaborate on these trends and then briefly describe the articles that were presented at the symposium and subsequently published in the University of Illinois Law Review. The symposium had two principal parts. The articles in the first part lay out the general case for empirical and experimental work in law, explain some of the relevant techniques, and predict future trends in empirical legal research. The articles in the second part concentrate on empirical and experimental work in particular areas of the law, such as contract law, tort law, corporation law, legal history, criminal law and procedure, and public choice. Those articles summarize the work done thus far and the issues that that work has resolved and then lays out the questions that further empirical and experimental work must seek to answer. The symposium is dedicated to the memory of Professor Gary Schwartz, who participated and whose contribution on empirical work in tort law graces the proceedings.
National Geographics: Toward a 'Federalism Function' of American Tort Law

Scholars of tort law are in apparent agreement over its dominant public law functions. Typically among those are corrective justice, loss distribution, and optimal deterrence. Inter-subjective dispute functions such as victim compensation are generally considered “secondary”, a fact which first-year law students often find perplexing. Meanwhile, tort doctrine — traditionally subject of state common law adjudication — has itself has come under increasing influence form federal constitutional, statutory, and regulatory authority. As this influence grows, should we be comfortable with increasing federalization of this immanently community-based norm system within civil justice? In this article, I argue that current contours in the federalization of tort law support what political theorists have referred to as “cooperative federalism” — a pattern of shared federal-state rule where authority remains divided based on competence and complementarity. Inviting state court adjudicators into contemporary debates on cooperative federalism, tort law itself becomes a new site for this intensive public law reflection. This role, the “federalism function” as this article terms it, should be recognized among the preeminent public law priorities interacting in Torts disputes today.
Guns, Bullets, Death: Reform

On March 8, 1998, my brother, Henry Lee Baber III, was shot 14 times and died instantly in Los Angeles, California by an unknown suspect, leaving behind a devastated mother, a child, a brother, a twin sister, and a sister who uses his tragedy to give a sense of urgency about why gun control needs to become next on the agenda for reforming current gun policy. Guns and the lack of control lead to the culture of violence seen in so many communities throughout the United States of America, especially in the Black community and this is an urgent matter. Multiple deaths and an intensifying violent culture have led thinkers to conclude that we need increased gun control. However, many conservative politicians and the gun industry argue that the regulation for gun control of the Second Amendment of the United States Constitution is unconstitutional. The amendment states: A well-regulated militia, necessary being to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.2 In a historical context, the Second Amendment grants the right to bear arms, but originally was founded to protect citizens from a tyrannical government from British rule; not against other citizens. The Second Amendment states that the right to bear arms shall not be infringed, but it does not say it cannot be regulated. Therefore, gun control does not violate the Second Amendment.
ATP-promoted interaction between Clp A and Clp P in activation of Clp protease from Escherichia coli.

Summary Clp protease is a high relative molecular mass, ATP-dependent protease found in the cytoplasm of Escherichia coli. Clp protease is composed of two protein components, Clp A, which has ATPase activity, and Clp P, which has the proteolytic active site and is activated by Clp A in the presence of ATP. Clp P subunits ( M r = 21 500) are arranged in two hexagonal rings directly superimposed on each other, and under low salt conditions two dodecamers associate to form a particle with M r ~ 440 000. Clp A (subunit M r = 83 000) and Clp P do not associate in the absence of nucleotide, but Clp A with ATP bound associates with Clp P to form an active proteolytic complex with M r ~ 700 000. Although adenosine 5′-[βγ-imido]triphosphate (AMPPNP) weakly promotes association between Clp A and Clp P, non-hydrolysable analogues of ATP do not activate proteolysis, indicating that association between the components is not sufficient to allow proteolysis. Association between Clp A and Clp P does not alter the basal ATPase activity of Clp A, but addition of protein substrates is accompanied by an increase in ATP hydrolysis by Clp A. Chemically-inactivated Clp P or inactive mutants of Clp P also associate with Clp A, but no increase in the ATPase activity of Clp A is observed, either in the presence or absence of protein substrates, when Clp P is inactive. Thus the increased ATP hydrolysis is dependent on active proteolysis. These data indicate that ATP has two functions in activating Clp protease: an allosteric role in promoting association between the subunits and a mechanistically undefined role in promoting continuous rounds of peptide bond cleavage. These functions may be separately fulfilled by the two ATP-binding sites identified by sequence analysis on each Clp A subunit.
Regional Economic Accounting (REAcct). A software tool for rapidly approximating economic impacts

This paper describes the Regional Economic Accounting (REAcct) analysis tool that has been in use for the last 5 years to rapidly estimate approximate economic impacts for disruptions due to natural or manmade events. It is based on and derived from the well-known and extensively documented input-output modeling technique initially presented by Leontief and more recently further developed by numerous contributors. REAcct provides county-level economic impact estimates in terms of gross domestic product (GDP) and employment for any area in the United States. The process for using REAcct incorporates geospatial computational tools and site-specific economic data, permitting the identification of geographic impact zones that allow differential magnitude and duration estimates to be specified for regions affected by a simulated or actual event. Using these data as input to REAcct, the number of employees for 39 directly affected economic sectors (including 37 industry production sectors and 2 government sectors) are calculated and aggregated to provide direct impact estimates. Indirect estimates are then calculated using Regional Input-Output Modeling System (RIMS II) multipliers. The interdependent relationships between critical infrastructures, industries, and markets are captured by the relationships embedded in the inputoutput modeling structure.