cssi/SciSciGPT-SciSciNet huggingface dataset:
Race disparities in genetic alterations within Wilms tumor specimens.

Abstract Background Wilms tumor (WT) affects Black children disproportionately. Genetic aberrations within WT specimens that contribute to this disparity have not been reported. Methods The Therapeutically Applied Research to Generate Effective Treatments (TARGET) database was queried for WT patient and genomic features. Clinical and genetic variables were compared by race. Results Within the discovery set (enriched for adverse events; N = 94 White, 19 Black, 14 Other/unreported patients), Black children were more likely to present with advanced stage disease (p = 0.019). Within the validation set (primarily a random sampling of NWTS-5; N = 360 White, 92 Black, 72 Other/Unreported), Black children appeared older at diagnosis (p = 0.050), had decreased median follow-up time (p Conclusion Within the TARGET database, Black children were over-represented and harbored WT specimens containing more frequent ACTB and DICER1 mutations. In contrast, WT from White children contained overall more mutations in targeted genes and specifically in DGCR8. Level of Evidence III.
Robotic Left Ventricular Lead Placement

In this chapter we detail a robotic method for implantation of epicardial pacing leads for resynchronization therapy. As 10–15 % of pacing leads cannot be placed along the lateral ventricular wall via the coronary sinus, this method is ideal because of the efficacy and minimal invasiveness. Herein, we describe the indications, patient selection, and robotic technique for this approach to resynchronization therapy.
Security and International Relations

This textbook presents security studies as a branch of international relations theory, providing readers with the critical conceptual tools to develop their expertise. The author evaluates the claims of rival theories - realism, neorealism, liberal institutionalism, classical economic liberalism, and Marxism - to explain why international actors choose or eschew force and coercive threats in order to elicit favorable outcomes in their interdependent exchanges. Also discussed are behaviorism and constructivism, contesting approaches to validate prevailing security paradigms. The author argues that only an interdisciplinary approach to security, drawing on the insights of each perspective, can meet the rigorous requirements of testable theory and the practical needs of actors in an increasingly globalizing world. The book will provide students and scholars of international relations and security studies with a valuable survey of the subject, and includes essay questions and guides to further reading.
TH-C-BRD-02: Optimization of CT Simulation Imaging in Radiation Therapy: Strategies and Tools

IGRT has significantly improved the accuracy of radiation treatment by utilizing CT scans for contouring target and organ during treatment planning and x-ray imaging devices integrated to treatment units for patient positioning during radiation delivery. A significant progress has been made recently to improve CT image quality in treatment planning and to reduce daily imaging guidance dose. This course is designed to provide educational guidance on these two important imaging issues. I) Optimization of CT Simulation Imaging. This part will provide guidance on optimizing CT image quality in radiation therapy. There have been many publications on optimizing CT protocols for diagnostic imaging purposes. However, the effort to optimize CT protocols for imaging applications in radiation therapy has been limited. Although some lessons we learn from diagnostic CT imaging can be applied to CT imaging in radiation therapy, there should be more emphasis on task-based image quality. In addition, there are imaging features widely used in diagnostic CT imaging (e.g., metal artifact reduction) may not be well known in radiation therapy community but can play critical roles for accurate radiation treatment planning. This part of the session will feature a conversation between a radiation therapy physicist and a diagnostic imaging physicist focusing on the needs specific to CT simulation imaging in radiation therapy and the approaches to address these needs. II) Techniques to reduce radiation dose resulting from daily imaging guidance procedures. This part will provide an overview of radiation dose to patients resulting from different image devices used in image-guided procedures and provide guidance on the techniques available to reduce imaging dose resulting from daily imaging guidance procedures. Depending on the image modality including MV and kV imaging devices, a variety of techniques are available to significantly reduce daily imaging guidance dose to organs at risk. Different methods of accounting for the imaging doses will be discussed. Learning Objectives: 1. Understand CT image quality needs specific to imaging applications in radiation therapy 2. Learn the imaging acquisition and reconstruction optimization for CT imaging applications in radiation therapy 3. Discuss appropriate approaches to optimize CT protocols in radiation therapy; 4. Briefly review the typical radiation dose to patients resulting from different image-guided procedures MV and kV imaging modalities; 5. Understand the techniques available to reduce imaging dose 6. Discuss different methods of accounting for the imaging doses
Gutta-percha root canal fillings. An in vitro analysis. I.

Abstract Eighty-seven extracted teeth were prepared with endodontic instruments, stored in 2.5 per cent sodium hypochlorite to remove organic debris, and then filled with gutta-percha by means of the lateral condensation method. The teeth were then decalcified and dissolved away, leaving the gutta-percha fillings. Examination of these fillings revealed (1) many irregularities in form and condensation, (2) inadequate sealer dispersion, (3) lack of demonstration of canal variations, such as fins and lateral canals, (4) lack of correlation with radiographs, and (5) roughness and pitting, in contrast to the smooth surfaces of previously described silicone models.
Quality Child Care: At Whose Expense?

Quality child care is related to the number of adequately prepared practitioners who are available to children on a long-term basis. Unfortunately, child care practitioners subsidize the true cost of quality child care by working for substandard wages, few benefits, and little recognition of their true worth. The need for adequate compensation for qualified caregivers is the most critical issue facing the profession, because adequate compensation enables trained and educated caregivers to remain in the field, invest in professional development, and it also attracts new students into the field. The true cost of quality should be shared by all members of society, for everyone benefits from investing in the citizens of the future.
Measurement and modeling of user transitioning among networks

Physical human mobility has played an important role in the design and operation of mobile networks. Physical mobility, however, differs from user identity (name) mobility in both traditional mobility management protocols such as Mobile-IP and in new architectures, such as XIA and MobilityFirst, that support identity mobility and location independence as first class objects. A multi-homed stationary user or a stationary user shifting among multiple devices attached to different networks will persistently keep his/her identity but will change access networks and the IP address to which his/her identity is associated. We perform a measurement study of such user transitioning among networks from a network-level point of view, characterizing the sequence of networks to which a user is attached and discuss insights and implications drawn from these measurements. We characterize network transitioning in terms of network residency time, degree of multi-homing, transition rates and more. We find that users typically spend time attached to a small number of access networks, and that a surprisingly large number of users access two networks contemporaneously. We develop and validate a parsimonious Markov chain model of canonical user transitioning among networks that can be used to provision network services and to analyze mobility protocols.
From Giant Robots to Mobile Money Platforms: The Rise of ICT Services in Developing Countries

In a world of outstanding diversity, perhaps one unifying theme is the desire to solve societal issues through technology. The momentum for success hinges on deploying these solutions in a market-appropriate way.
Configurational Design of Superconductive Energy Storage Magnets

The concept of magnetic energy storage is well known, but the engineering task of developing economical superconductive storage units is a relatively new endeavor. Much of this effort depends on the large-scale production of high-current conductors, large refrigeration systems, etc. However, it is also vital to determine magnet configurations that use these materials in the most efficient ways. This paper discusses the relations which connect energy and magnetic field to a variety of cost-related parameters.
Measurements of Resonance in a Forward-Facing Cavity at Mach Six

An experimental study of the resonance of a cylindrical forward-facing cavity was conducted in a Mach 6 quiet-flow wind tunnel. The diameter of this cavity was fixed and the depth was varied in order to find the critical depth at which the cavity resonance became self-sustained. At Mach 6, this critical depth was 1.2 diameters deep, regardless of the freestream noise levels. For cavities deeper than 1.2 diameters, measurements of root-mean-square pressure fluctuations were orders of magnitude larger than those in shallower cavities. In quiet flow, this increase was about 2.5 orders of magnitude. In noisy flow, this increase was only about one order of magnitude. However, the magnitude of the pressure fluctuations within deep cavities was about the same in quiet flow as it was in noisy flow. The damping characteristics of a shallow cavity (depth less than 1.2 diameters) were also studied by observing the cavity response to a freestream laser-generated perturbation. The perturbation convects with the flow a...
Compensation at Level 3 Communications

SYNOPSIS: The compensation committee of Level 3 Communications will soon meet to re-evaluate the indexed executive stock option plan used to compensate its top managers and other employees. This review takes place within the context of a troubled telecommunications industry; like many firms in that industry, Level 3 has seen its stock price drop by more than 50% over the previous year. TEACHING OBJECTIVES: The purpose of this case is to explore the desirability and structure of relative-performance-based compensation, specifically focusing on the indexed option plan adopted at Level 3 Communications. The case is taught in the second-year MBA-level corporate finance course as part of a module focused on compensation. Alternatively, it could be taught in a financial engineering class by narrowing its focus to emphasize the valuation and structure of the financial instrument, a "levered" indexed option, used to implement the plan.
Currency Futures, Options, Derivatives, and Swaps

Forward exchange contracts had been available for decades, but it was not until the breakdown of the Bretton Woods system of fixed exchange rates and the resulting heightened volatility in currency prices that new foreign exchange risk management products started to appear. Futures contracts on foreign exchange were first introduced in May 1972 when the International Money Market of the Chicago Mercantile Exchange began trading contracts on the British pound, Canadian dollar, Deutsche mark, Japanese yen, and Swiss franc.
Ultrafast electronic dynamics in unipolar n-doped InAs/GaAs quantum dot structures

Time-resolved mid-infrared-pump, optical-probe differential transmission spectroscopy on n-doped quantum dots directly reveals electron dynamics relevant to unipolar devices. Capture times into excited and ground states are found to be 7.1 and 116 ps.
Cryotherapy in prostate cancer

Review objectives:Cryotherapy use has increased due to technological advances. A review of the literature was performed to evaluate the efficacy and outcomes of whole gland, salvage and targeted fo...
Unbounded derivations in operator algebras

Abstract Unbounded derivations in uniformly hyperfinite C ∗ -algebras will be studied. Various conditions, under which normal ∗ -derivations in the C ∗ -algebras can be extended to the infinitesimal generators of the approximately inner strongly continuous one-parameter subgroups of ∗ -automorphisms on the algebras, will be given.
A Question of Taste: Crypsis and Warning Coloration in Freshwater Zooplankton Communities

Visual predation by fishes appear to have driven prey towards divergent extremes, with two of the alternative avenues dependent upon initial palatability. On the one hand, selective predation upon initially large—bodied, strongly pigmented, and highly palatable zooplankton has selected for reduced conspicuousness (smaller body size at maturity, increased transparency of tissues). On the other hand, selective predation upon initially pigmented, yet mildly unpalatable groups (e.g., water mites), has selected for enhanced conspicuousness and increased distastefulness. At the basis of these two diverging selective responses lies the initial mouthing experiences of the predator, i.e., whether the image of the prey is associated with pleasure (reward) or with pain (punishment). While aposematic coloration seems limited among zooplankters to special cases, chemical defenses appear to be more widespread than commonly believed. See full-text article at JSTOR
The Structure of Witnessed Community Violence amongst Urban African American Mothers: Latent Class Analysis of a Community Sample

The prevalence of witnessed community violence (WCV) amongst urban populations in the USA is striking. WCV can be harmful to one's psychological health, and for mothers, the consequences may be more far-reaching as their mental health affects parenting and child development. This study used telephone interviews (n = 209) to explore the patterns and covariates of WCV amongst a sample of urban, African American mothers of infants. Mothers reported whether they had witnessed 11 different forms of violence in their current neighborhoods. A latent class analysis revealed two distinct groups of mothers, those with higher versus lower-exposure to WCV. Mothers in the higher-exposure group were more likely to be low-income, to have a high school education or less, and to have higher anxiety scores than those in the lower-exposure group. Depression was not associated with higher exposure to WCV. Distinguishing between higher- and lower-exposure samples can inform the development of targeted prevention and intervention strategies for metropolitan areas.
Soil Penetration Modeling in Microtunneling Projects

As the need for utility service line replacement or repairs with minimum disruption to the surface have increased, so has the demand for trenchless excavation methods, in particular, microtunneling. Microtunneling is a trenchless technique that is used to install new pipelines. Microtunneling can be applied in gravity and pressure lines, permanent ducts for cables, and crossings under rails or roads. When bidding a microtunneling project, the main concern of microtunneling contractors is predicting the underground behavior of the machine. In other words, the productivity of microtunneling is the key to profit in microtunneling projects. Contractors generally predict approximate productivity based on experience, which risks cost estimation accuracy for microtunneling projects. Contractors lack a productivity model that helps them to predict driving time. This paper is a part of a series of papers covering the productivity of microtunneling projects. This paper focuses on predicting the penetration time of the microtunneling machine.
Fetal surgery for sacrococcygeal teratoma

A great deal has been learned regarding the natural history and pathophysiology of fetal SCT. The logic behind fetal intervention for SCT and hydrops appears to be correct, and open and minimal access techniques of fetal intervention have been shown to be feasible. The development of fetal intervention for SCT has mirrored those developed for other diseases such as congenital diaphragmatic hernia. In a recent presentation, Harrison, the original pioneer in fetal surgery, outlined trends in fetal intervention. The first trend is that of moving from open, invasive techniques to minimally invasive techniques. In the case of SCT surgeons are moving from open resection to RFA and possibly to fetoscopic resection. The second trend outlined by Harrison is a movement away from total in utero repair of a defect that recapitulates postnatal treatment and toward manipulation of fetal pathophysiology to reverse life-threatening events. In SCT surgeons employ RFA to ablate causative blood vessels to reverse fetal hydrops with the knowledge that these fetuses will require postnatal resection of the tumor. In contrast to resection, RFA requires less time and significantly less maternal morbidity than open resection. Further study is required to determine the role of minimal access techniques in SCT. Future directions for treatment of fetal SCT with hydrops might include fetoscopic resection or high-intensity ultrasound ablation.
Conflict Theory, Economic Conditions, and Homicide A Time-Series Analysis

Conflict theorists often specify an inverse relationship between economic conditions and crime. Empirical support for this contention in time-series analyses, however, has been inconsistently revealed in the literature, where positive, inverse, and null results have all been found. Part of the problem may be attributed to the inability of traditional measures of economic deprivation to fully capture the dynamics of a changing economic market. Accordingly, this article contains a specific empirical test of the economics-crime relationship using a different measure of economic conditions (a composite measure of coincidental economic indicators)and examining its relationship with homicides over time for total homicides, felony murders ,and acquaintance homicides. Consistent with the tenets of conflict theory, the analysis reveals considerable support for an inverse relationship between economic conditions and homicide rates. Furthermore, although changes in economic conditions significantly predicted levels of both total and acquaintance homicides, the effect was strongest in the model predicting instrumental homicides (felony murders).
Direction-selective adaptation and simultaneous contrast induced by stereoscopic (cyclopean) motion

Across four experiments, this study investigated direction-specific adaptation and simultaneous contrast induced by moving binocular disparity information (stereoscopic motion). The stimuli were moving arrays of stereoscopic dots created from dynamic random-element stereograms. Experiments 1 and 2 examined the effects of adaptation to motion in a given direction on the apparent direction of test motion. Results showed that the direction of test motion appeared repulsed away from the direction of adapting motion (repulsion aftereffect) by as much as 20 deg or more when directions of adapt and test were similar. Experiment 3 investigated transfer of the repulsion aftereffect across the stereoscopic and luminance domains by employing stereoscopic adapting motion and luminance test motion or vice versa. Results showed that the repulsion aftereffect transferred across the two stimulus domains. Experiment 4 investigated direction-specific contrast by measuring the perceived direction of two stereoscopic arrays presented simultaneously and moving in different directions. Results showed that the directions of the arrays appeared repulsed away from one another when their directions were similar. Taken together, these results suggest that the direction of stereoscopic motion is coded in the activity of directionally selective mechanisms, as is the case for luminance-domain motion. Transfer of the repulsion aftereffect between stereoscopic and luminance domains indicates the two kinds of motion perception are mediated by a common substrate.
Excitation of Al K and Hf M X-Ray Lines by 70-400-keV H + , He ++ , N ++ , O ++ , and Ar ++ Ions

The $K$ shell of aluminum and the $M$ shell of hafnium have been excited using H, He, N, O, and Ar ions in the energy range 70-400 keV. The appearance of an excitation mechanism is observed for N, O, and Ar projectiles, which results in ionization cross sections several orders of magnitude greater than those predicted by a direct-scattering interaction such as is assumed for H and He ions. The results are examined in the light of the electron promotion mechanism of molecular-orbital theory as suggested by Der et al. The similar increases in cross sections for the hafnium $M$ shell and the aluminum $K$ shell using incident ions heavier than He suggest that an electron promotion mechanism does not provide a satisfactory explanation of the anomalous cross sections. It is felt that other factors, such as polarization of the relevant atomic shells of both the target atom and the projectile at close impact distances, must be considered in terms of the direct-scattering theory.
Image Feature Extraction For Automatic Terrain Classification

In a previous paper,1 an approach to automatic classification of terrain types in aerial photographs was described. Experiments verifying the approach were conducted on a computer-controlled cathode ray tube scanner system called the Natural Image Computer (NIC). The system simulated in serial fashion concepts of parallel local image shape extraction and decision derived from prior optical experiments.2,3 Classification experiments were performed on terrain samples of orchards, woods, lakes, oil tank farms, and railroad yards on 1:50,000 scale imagery, with a resolution corresponding to four feet on the ground.
Optical pattern generator for visual research.

A method for generating a wide variety of visual patterns on a cathode ray tube (c.r.t.) is described. It is easily implemented with readily available integrated circuits and provides a high degree of precision and flexibility.
Temporal organization of sleep-wake states in preterm infants.

The development of temporal organization of sleep–wake states during the preterm period was examined. Seventy-one high-risk preterms from two cohorts were observed from 7 to 11 p.m. weekly from the time they were no longer critical until discharge. Mixed general linear model analyses found that with increasing postconceptional age, quiet waking, active waking, and sleep–wake transition bouts occurred more frequently, quiet sleep bouts occurred less frequently, and active waking and quiet sleep bouts increased in length. However, these developmental patterns were not stable over cohorts. On the other hand, the transitional probabilities between states were similar in both cohorts, providing evidence for biological bases for some aspects of temporal organization. Active sleep was pivotal in state transitions. Younger infants showed fewer transitions that did not involve active sleep. Thus, temporal organization is an early characteristic of sleep–wake states but is not a unitary phenomenon. Transitional probabilities remain relatively invariant, whereas bouts lengths and frequencies may be altered in different populations or by differing environmental conditions. © 1998 John Wiley & Sons, Inc. Dev Psychobiol 33: 257–269, 1998
Biological after-effect and long-lived free radicals in irradiated seeds.

Biological damage in irradiated barley seeds was measured as damage to seedling growth, survival of the seed to a mature plant, chromosomal aberrations, or mutation. The various damages were found to be related. It is postulated that the biological after-effect in irradiated dry seeds is due to decay of the long-lived free radicals, derived from radicals initially generated by the radiation, and persisting after the irradiation is over. Results are reported from studies on the effects of various treatments, such as water, oxygen, other gases, and temperature, on postirradiation free radicals and on the after-effect phenomena in irradiated barley seed. (C.H.)
Pre-steady-state and stopped-flow fluorescence analysis of Escherichia coli ribonuclease III: insights into mechanism and conformational changes associated with binding and catalysis.

Abstract To better understand substrate recognition and catalysis by RNase III, we examined steady-state and pre-steady-state reaction kinetics, and changes in intrinsic enzyme fluorescence. The multiple turnover cleavage of a model RNA substrate shows a pre-steady-state burst of product formation followed by a slower phase, indicating that the steady-state reaction rate is not limited by substrate cleavage. RNase III catalyzed hydrolysis is slower at low pH, permitting the use of pre-steady-state kinetics to measure the dissociation constant for formation of the enzyme-substrate complex (Kd=5.4(±0.6) nM), and the rate constant for phosphodiester bond cleavage (kc=1.160(±0.001) min−1, pH 5.4). Isotope incorporation analysis shows that a single solvent oxygen atom is incorporated into the 5′ phosphate of the RNA product, which demonstrates that the cleavage step is irreversible. Analysis of the pH dependence of the single turnover rate constant, kc, fits best to a model for two or more titratable groups with pKa of ca 5.6, suggesting a role for conserved acidic residues in catalysis. Additionally, we find that kc is dependent on the pKa value of the hydrated divalent metal ion included in the reaction, providing evidence for participation of a metal ion hydroxide in catalysis, potentially in developing the nucleophile for the hydrolysis reaction. In order to assess whether conformational changes also contribute to the enzyme mechanism, we monitored intrinsic tryptophan fluorescence. During a single round of binding and cleavage by the enzyme we detect a biphasic change in fluorescence. The rate of the initial increase in fluorescence was dependent on substrate concentration yielding a second-order rate constant of 1.0(±0.1)×108 M−1 s−1, while the rate constant of the second phase was concentration independent (6.4(±0.8) s−1; pH 7.3). These data, together with the unique dependence of each phase on divalent metal ion identity and pH, support the hypothesis that the two fluorescence transitions, which we attribute to conformational changes, correlate with substrate binding and catalysis.
Black hole evaporation with separated fermions.

In models with a low quantum gravity scale, fast proton decay can be avoided by localizing quarks and leptons to separated positions in an extra $1/\mathrm{T}\mathrm{e}\mathrm{V}$ sized dimension with gauge and Higgs fields living throughout. Black holes with masses of the order of the quantum gravity scale are therefore expected to evaporate nonuniversally, preferentially radiating directly into quarks or leptons but not both. Should black holes be copiously produced at a future hadron collider, we find the ratio of final state jets to charged leptons to photons is $113\ensuremath{\mathbin:}8\ensuremath{\mathbin:}1$, which differs from previous analyses that assumed all standard model fields live at the same point in the extra dimensional space.
Electrochemical and Adsorption Properties of PAMAM Dendrimers Surface-Functionalized with Polypyridyl Cobalt Complexes

Polyamidoamine dendrimers (generations 1 and 3) surface-modified with terpyridyl cobalt complexes have been prepared and characterized by electrochemical and EQCM (electrochemical quartz crystal microbalance) techniques. EQCM studies of the dendrimer complexes show that they deposit onto a Pt electrode following the Co(II/I) reduction process and that the resulting films prevent further deposition upon successive potential scanning. The effects of electron self-exchange were observed for Co(I/II) redox processes for adsorbed layers of the dendrimers. Further, the thermodynamics and kinetics of adsorption of the dendrimers have been studied using electrochemical methods. These metallodendrimers adsorb (up to a monolayer equivalent) onto Pt electrodes at −0.20 V vs Ag/AgCl, where the Co sites have +2 charges, and the adsorption thermodynamics is well characterized by the Langmuir adsorption isotherm. The kinetics of adsorption is activation-controlled and the rate constant is larger for the higher generatio...
Transition and transport in a buoyancy driven flow in water adjacent to a vertical uniform flux surface

Abstract This experiment, in water at room temperature, accurately maps changes in the mean temperature distribution from laminar flow, through changes during transition, to full turbulent flow. Temperature disturbance levels are also determined. Simultaneously, very accurate measurements of local heat-transfer parameters were made to high Rayleigh numbers. Our objective was to interrelate different past criteria for the beginning of thermal transition and to find any characteristic patterns during transition. It was found that such criteria are internally consistent but some systematically disagree with others because of differences in methodology. Mean profiles and transport are relatively unambiguous. Further, some events during transition may also be correlated, from our measurements, both in terms of mean profiles and heat transfer. Transport in laminar, in transition and in turbulent flow are mapped. In the first regime, it agrees with theory and in the last, with the correlation of Vliet and Liu [1]. Mean temperature distributions in full turbulence are in very close agreement with the new transport theory of George and Capp [2].
COMPARISON OF ROC AND LIKELIHOOD DECISION METHODS IN AUTOMATIC FINGERPRINT VERIFICATION

The biometric verification task is to determine whether or not an input and a template belong to the same individual. In the context of automatic fingerprint verification the task consists of three steps: feature extraction, where features (typically minutiae) are extracted from each fingerprint, scoring, where the degree of match between the two sets of features is determined, and decision, where the score is used to accept or reject the hypothesis that the input and template belong to the same individual. The paper focuses on the final decision step, which is a binary classification problem involving a single score variable. The commonly used decision method is to learn a score threshold from a labeled set of inputs and templates, by first determining the receiver operating characteristic (ROC) of the task. The ROC method works well when there is a well-registered fingerprint image. The paper shows that when there is uncertainty due to fingerprint quality, e.g. the input is a latent print or a partial print, the decision method can be improved by using the likelihood ratio of match/non match. The likelihood ratio is obtained by modeling the distributions of same finger and different finger scores using parametric distributions. The parametric forms considered are Gaussian and Gamma distributions whose parameters are learnt from labeled training samples. The performances of the likelihood and ROC methods are compared for varying numbers of minutiae points available for verification. Using either Gaussian or Gamma parametric distributions, the likelihood method has a lower error rate than the ROC method when few minutiae points are available. Likelihood and ROC methods converge to the same accuracy as more minutiae points are available.
Type curves and effective parameters for unsaturated flow systems with structured heterogeneities

Unsaturated flow simulation requires identification of soil parameters at length scales that usually subsume smaller-scale heterogeneities. The standard two-parameter constitutive model performs well for predictions of moisture plume evolution in homogeneous soils but may not be as successful in capturing the flow and dispersion of soil water in heterogeneous domains. The first step in evaluating the limitations of this model is to develop a clear understanding of the effects of the constitutive parameters on moisture plume evolution. One approach is to define type curves derived from multiple homogeneous simulations. These type curves are based on bulk measures of system behavior, suitable for comparison to responses of heterogeneous systems. Simulation results for a range of heterogeneities defined on a specific test system indicate that some heterogeneity patterns allow definition of effective parameters for use in the two-parameter constitutive model, while others do not. For those heterogeneity patterns, the mathematical structure of the governing equations applied at the large scale must have a form that is different from the equation that underlies the type curves.
On the use of a structured technique in facilitating systems interventions

Abstract The paper discusses the effect of the systems age on problem solving. The problem which exist in organizations usually require discussions among the decision makers. Such discussions are intended to lead to a dialogue which hopefully results in effective corrective actions. This paper suggests that a structured information processing model can be used to help motivate the dialogue necessary to develop a design to cope with the systems problem. A case is discussed.
A new measure of placebo response and patient satisfaction in office encounters.

OBJECTIVES: Placebo response is defined as a change in health status resulting from the symbolic significance attributed by the patient or proxy to the physician encounter. Our goals were to validate the PR12 survey as a measure of placebo response and to analyze the placebo response as a discrete and measurable component of everyday office encounters with the otolaryngologist.STUDY DESIGN: This was a prospective, before-and-after clinical outcomes study of 95 children aged 6 months to 12 years conducted in an academic metropolitan pediatric otolaryngology practice. Caregivers completed the PR-12 survey at entry and at least 4 weeks later. The survey included 3 domains (4 questions each) reflecting the main components of the placebo response: meaningful explanation, care and concern, and mastery and control. PR-12 was correlated with longitudinal change in health status at least 1 to 2 months after the baseline visit. Outcome measures included direct and indirect measures of change in disease-specific qua...
Neurotrophin-4/5 treatment reduces infarct size in rats with middle cerebral artery occlusion

The aim of this study was to determine whether neurotrophin-4/5 (NT-4/5) treatment alters infarction volume following permanent focal cerebral ischemia in the rat. Permanent focal cerebral ischemia was produced in adult male rats by intraluminal occlusion of the right middle cerebral artery. NT-4/5 was administered intraventricularly one day before and immediately following occlusion. Rats were sacrificed at 1, 4 and 7 days after occlusion. NT-4/5 treatment reduced infarction volume by 34% when compared to control rats 1 day after occlusion. Infarction volume was unaltered by treatment 4 to 7 days after occlusion. Middle cerebral artery occlusion led to a significant reduction in levels of mRNAs coding for catalytic and truncated TrkB receptors. This expression was unaffected by NT-4/5 treatment.
Synthesis and mechanistic investigations of the decomposition of β-hydrogen containing W(VI) dialkyl complexes: β-H elimination vs. β-H abstraction

Abstract The dialkyl complexes containing β-hydrogen atoms:W(NPh)[o-(Me3SiN)2C6H4]R2 (R = Et, n-Pr, i-Bu, CH2CH2Ph) have been prepared.These compounds are indefinitely stable in solution at room temperature in the absence of air and moisture.The diethyl complex reacts with PMe3 at room temperature (t1/2 = 12 min) to give ethane and the W(IV) ethylene complex, W(NPh)[o-(Me3SiN)2C6H4](η2-CH2CH2)(PMe3)2.A mechanistic study of this reaction has revealed that the reaction is first order in W and PMe3, with ΔH‡ = 5.1(0.6) kcal mol−1 and ΔS‡ = −54.9(2.0) cal mol−1 K−1.A large primary kinetic isotope effect (kH/kD = 6.1(0.5) at 20 °C) was observed for the transformation.These observations are consistent with the reaction proceeding via direct H transfer from the β-carbon of one ethyl group to the α-carbon of the other ethyl group.The (bis)phenethyl complex reacts with PMe3 at elevated temperature to give ethylbenzene and the W(IV) styrene complex, W(NPh)[o-(Me3SiN)2C6H4](η2-CH2CHPh)(PMe3)2.Significantly different activation parameters (ΔH‡ = 13.7(0.8) kcal mol−1 and ΔS‡ = −36.7(2.3) cal mol−1 K−1) and a phosphine concentration dependent kinetic isotope effect (kH/kD = 6.4(5), [PMe3] = 0 M; kH/kD = 4.3(3), [PMe3] = 0.4 M; kH/kD = 2.4(4), [PMe3] = 0.8 M; extrapolated to room temperature) were observed, suggesting two competing pathways (β-hydride elimination and β-H abstraction) are accountable for the transformation.
A method for modeling the winding pattern of a large scale superconducting cable [ITER magnet]

To find the behavior of a large scale cable, one must find an accurate method for describing the inner geometry of these cables. A new approach has been developed which uses the idea that subcomponents of the cable rotate about a center of inertia. This methodology can be used for a variety of geometries where compaction due to the manufacturing process makes the geometry difficult to model. Finally, this algorithm is applied to the design of the cable-in-conduit conductor for the proposed ITER magnet.
An EELS and TPD study of the adsorption and decomposition of acetic acid on the Al(111) surface

Abstract The adsorption and decomposition of acetic acid on Al(111) have been studied using electron energy loss spectroscopy (EELS), temperature programmed desorption (TPD), and Auger electron spectroscopy (AES). Acetic acid reacts with clean Al(111) at 120 K to form a surface acetate species. The adsorbed acetate bonds to the surface in a symmetric configuration with C s symmetry at 120 K. The adsorption of molecular acetic acid occurs at this temperature only after saturation of the surface acetate layer; this physisorbed multilayer desorbs molecularly at 167 K. Thermal decomposition of the adsorbed acetate leads to a carbon- and oxygen-covered surface; the only detectable thermal decomposition product is H 2 . Electron irradiation induces a similar decomposition process of the surface acetate.
How can we improve tracking of transplanted tissue in the United States

Currently an estimated two million tissues are distributed for transplantation annually. With increasing use of recovered tissue, clusters of transplant-transmitted infection have shown the difficulty of tracking tissues from an infected donor to the recipient. The challenge of tissue tracking to multiple transplant recipients was illustrated in a recent investigation of transmission of hepatitis C virus infection from a donor of organs and tissues. When a tissue bank issued a recall of the donated tissue, the Centers for Disease Control and Prevention was notified to assist public health authorities; the mean time to locate and notify the physicians who had transplanted the tissue was 13 days, while the mean time to notify, inform, and test the patients was 29 days. Lack of common coding and nomenclature was one of the key challenges in tracking tissue to the recipient. Some changes that could improve timeliness in the event of a recall includes: (1) standardized tissue nomenclature and coding through unique donor identifiers; (2) tissue traceability requirements using systems similar to that used for blood products; (3) a surveillance system for adverse events that provides feedback at the provider level.
NMR Studies of Polyaldehydes

Abstract The large differences in chemical shifts that result from oxygen's being incorporated into the polymer backbone yield more accurate qualitative and quantitative analysis through NMR than those polymers that do not have oxygen in the backbone. Configuration effects are observed without interference from methylene groups that frequently interfere in the analysis of polymers. However, the results obtained on polyacetaldehyde with the new 200-MHz Varian Instrument at ambient temperature show a much more complete definition of the configuration than can be obtained with lower-frequency instruments. They show that there are more isotactic triads than syndiotactic triads for the methyl group in “atactic” polyacetaldehyde and that this polyacetaldehyde is nearly a random polymer. By means of the new 220-MHz Varian Instrument and heating of the samples to elevated temperatures for better-resolved lines complete configurational analysis of polyacetaldehyde should become possible.
Effects of early-postmortem glycolytic rate on beef tenderness.

Electrical stimulation (ES) was applied at 500 V to one side from each of 60 beef carcasses at 30 to 40 min postmortem. Wide ranges of early-postmortem glycolytic and cooling rates were produced in the musculature by use of three different forms of ES (in addition to non-ES treatment of the contralateral sides) and application of chilling routines of four different degrees of severity. Panel and Warner-Bratzler shear evaluations of loin steaks from all 120 sides showed that tenderness was highest when glycolysis had proceeded at an intermediate rate (corresponding to the attainment of a 3-h pH of about 6·1) and was appreciably lower on both sides of this mid-value. The toughening effect of rapid glycolysis (relative to that of a moderately increased glycolytic rate) persisted through 14 days of aging at 2°C. These observations appear to be incompatible with the view that lysosomal enzymes contribute significantly to ES-induced tenderization. They also indicate that the effect of ES on tenderness is highly dependent on the subsequent cooling rate, very slow chilling sometimes accelerating the already high rate of pH fall to such an extent that the tissue is significantly toughened. Finally, they suggest that the goal of maximizing the early-postmortem rate of pH decline in bovine muscle is misguided and, if attained, will cause sub-optimal tenderness.
Comparative Pathogenesis of Autographa californica M Nuclear Polyhedrosis Virus in Larvae of Trichoplusia ni and Heliothis virescens

Abstract We compared early viral pathogenesis and dose mortality relationships for larvae of two highly susceptible hosts, Trichoplusia ni and Heliothis virescens, using a construct of AcMNPV containing the lacZ reporter gene. Larvae were inoculated either as newly molted fourth instars (40) or 15 hr after the molt (415). In 40-inoculated larvae, first lacZ expression was detected in the midgut epithelium of T. ni at 4 hr postinoculation (hpi) compared to 18 hpi in H. virescens, and systemic infections were initiated from tracheole cells servicing the midgut epithelia beginning at 12 and 20 hpi, respectively. The longer viral tenure within the midgut and the slower progression of systemic infections within H. virescens ultimately contributed to its longer time to death. For 40-inoculated H. virescens, proportions of lacZ-expressing larvae increased from 18 hpi until the onset of the molt to the fifth instar at 36 bpi; at this time point, the proportion of signaling insects equaled the final larval mortality. Viral infections within the midgut epithelium of H. virescens were lost during the molt to the fifth instar. Dose-mortality relationships suggested that the peritrophic membrane provided little protection from AcMNPV infections for either species.
Nucleosome dynamics regulate Neurospora circadian clock

How are circadian rhythms epigenetically regulated? Liu and colleagues have discovered a critical circadian clock component, CATP, that regulates rhythmic nucleosome occupancy at the clock gene frequency in Neurospora.
Simulation study of several solar heating systems with offpeak auxiliary

In essentially all climates, solar heating systems for buildings must incorporate back-up conventional (auxiliary) heating equipment sized to meet the maximum load of the building. In areas with high densities of solar heated buildings using auxiliary energy supplied by utilities, unacceptable peaks in auxiliary energy demand (during cloudy weather) can be prevented via limited on-site storage of the utility supplied energy. In this paper several ''offpeak auxiliary'' solar air heating systems are compared using simulation methods. Two basic types of offpeak systems have been studied; Systems I and II, which separate the storage of auxiliary and solar energy, and Systems III and IV, which store all energy in the same pebble bed. Simulation methods are used to determine the effect of system configuration, collector loss coefficient, controls, storage size, and collector flow rate on system performance.
The α-glucosidases of Streptococcus pyogenes and derived l form

Abstract Two α-gluclosidases, maltase and isomaltase, were detected and isolated from mid-logarithmic grown cells of Streptococcus pyogenes and from the derived stable l form. These enzymes were localized in the cytoplasm of each organism and were resolved by gel filtration. It was found that in the presence of α-methylglucoside, the induced synthesis of these α-glucosidases was significantly greater (from 1.5 times or more) in the l form than in the parental coccus. l -form whole cells were found to accumulate this inducer to levels more than twice as high and at a faster rate than did S. pyogenes . Induction also occurred when maltose replace α-methyl-glucoside as the inducer. Induction of maltase and isomaltase leveled off or decreased in the coccus but continued within the l form as the concentration of either inducer was increased. Growth of S. pyogenes in l -form medium in the presence of either inducer proved that continued and increased enzymatic induction withi the l form was not due to an osmotic effect. These induction and labeled α-methylglucoside-uptake studies together with the observation that induced α-glucosidase synthesis is markedly inhibited by coccal cell wall carbohydrates in the streptococcus but not in the l form suggest that an alteration in the regulatory mechanism of α-glucosidase synthesis has occurred upon conversion of S. pyogenes to the l form. The possibility of these results being related to an inability by the l form to form a rigid cell wall is discussed.
Physical adsorption of xenon on Pd(100)

The interaction of xenon with the (110) surface of palladium has been examined by LEED, work function and Auger electron spectroscopy. At 77 °K the sticking coefficient is near unity up to a maximum coverage of 5.8 × 1014 atoms per cm2. The overlayer is highly disordered except near maximum coverage where a close-packed hexagonal structure is formed. From variations in the work function with coverage, it is found that the polarizability of adsorbed Xe is 8.2 × 10−24 cm3, or twice that of the isolated Xe atom. The isosteric heat of adsorption decreases monotonically from 0.33 eV at zero coverage to about 0.28 eV at monolayer coverage, indicating that the lateral XeXe interaction is repulsive.
To be consumed with moderation

Abstract We study the optimal behavior of a hyperbolic discounting agent who has incomplete information about his own preferences and can only learn them through consumption. We show that, even if moderate current consumption and moderate future consumption always dominates abstinence, the agent may optimally decide not to consume as a commitment device against inefficient learning that would lead to future excesses. This provides a rationale for why smokers, gamblers or compulsive buyers stick to second-best personal rules of behavior – such as “abstinence” – without invoking standard habit formation arguments. We also study how urges modify the strategy of the individual.