cssi/SciSciGPT-SciSciNet huggingface dataset:
TGF‐β1 perturbation of the fibroblast cell cycle during exponential growth: switching between negative and positive regulation*

We have demonstrated previously that SV40 T antigen and serum regulate the length of G1 in exponentially growing NIH-3T3 cells in part by inhibiting density dependent negative cell cycle regulation. In these studies it was suggested that T antigen positively regulated G1 in a density independent manner as well. In this report we show that, 24 h after treatment, TGF-beta 1 perturbs the cell cycle of exponentially growing fibroblasts in a manner similar to T antigen. However, prior to 24 h, TGF-beta 1 produced a negative response, elongating the G1 phase of the cell cycle that was followed by a positive response, both of which were density independent. This biphasic response was measured between 0 and 12 h post-treatment and was relative to responses from serum. This switch from an early inhibitory effect to a late stimulatory effect was associated with changes in Rb phosphorylation, the timing and magnitude of which indicated that Rb may be directly regulating TG1 rather than reporting changes in the population. This is further substantiated by abrogation of the inhibitory effect by expression of wild-type SV40 T antigen and retention of the effect in cells that express an Rb-binding mutant of T antigen (K1). The biphasic regulatory effects of TGF-beta 1 were also displayed in WI-38 and IMR-90 human fibroblasts. This suggests that this biphasic effect is a property of fibroblasts.
Computational Modeling Predicts Phosphatase Oxidation as an Important Axis of Redox Regulation in IL-4 Signaling

Reactive oxygen species (ROS) are produced following activation of several types of cell surface receptors and can play an important role in modulating cell signaling. How simultaneous oxidative modifications of multiple proteins, sometimes with potentially opposite effects, regulate cell signaling is not well understood at the system level. We are using computational modeling based on quantitative experimental measurements to develop a systemic understanding of redox regulation of cell signaling in the context of the IL-4 signaling pathway. We observe that IL-4 signaling in Jurkat cells is accompanied by transient ROS production, and ROS augment signaling activity as measured by STAT6 phosphorylation. A number of candidate redox-regulated mechanisms exist in the IL-4 pathway that could contribute to the observed outcomes; however, it is technically challenging to directly measure redox modifications of the possibly redox-regulated proteins. To circumvent this issue, we have developed kinetic models of IL-4 signaling that incorporate competing hypotheses regarding redox regulatory mechanisms. With the guidance of measurable experimental data we are using innovative model selection strategies to determine the best candidate models. We have also acquired time course data for processes not directly related to redox regulation, such as transcriptional negative feedback regulation and proteasomal degradation as mechanisms for downregulating IL-4 signaling, that aid model selection and validation. Our results so far indicate that reversible oxidative inhibition of phosphatases and compartmentation of phosphatase activity between subcellular compartments may be the primary redox regulatory mechanisms in IL-4 signaling. These studies will help evolve an understanding of how oxidative modifications of different components of the signaling pathway operate in parallel along with better studied post-translational modification mechanisms of protein regulation to determine the overall dynamics of cell signaling.
Molecular Dynamics Simulations of the Complete Satellite Tobacco Mosaic Virus

This work presents an all-atom molecular dynamics simulation of a complete virus, the satellite tobacco mosaic virus. Simulations with up to 1 million atoms for over 50 ns demonstrate the stability of the entire virion and of the RNA core alone, while the capsid without RNA exhibits a pronounced instability. Physical properties of the simulated virus particle including electrostatic potential, radial distribution of viral components, and patterns of correlated motion are analyzed, and the implications for the assembly and infection mechanism of the virus are discussed.
Covert Penetration Systems

This paper discusses past, present, and future strategic aircraft requirements for ingress and egress, then focuses on the technologies of the CO 2 Laser Radar and the Automatic Target Recognizer. Present systems currently consist of a mix of various sensors which are not correlated until each is presented to the operator. Additionally, active sensors are highly detectable by threat warning systems, while passive sensors do not provide critical range information. CO 2 Laser and ATR technologies will significantly contribute to the resolution of these issues.
Aquaporin-1 Tunes Pain Perception by Interaction with Nav1.8 Na+ Channels in Dorsal Root Ganglion Neurons

Aquaporin-1 (AQP1) water channels are expressed in the plasma membrane of dorsal root ganglion (DRG) neurons. We found reduced osmotic water permeability in freshly isolated DRG neurons from AQP1−/− versus AQP1+/+ mice. Behavioral studies showed greatly reduced thermal inflammatory pain perception in AQP1−/− mice evoked by bradykinin, prostaglandin E2, and capsaicin as well as reduced cold pain perception. Patch clamp of freshly isolated DRG neurons showed reduced action potential firing in response to current injections. Single action potentials after pulse current injections showed reduced maximum inward current, suggesting impaired Nav1.8 Na+ function. Whole-cell Nav1.8 Na+ currents in Nav1.8-expressing ND7-23 cells showed slowed frequency-dependent inactivation after AQP1 transfection. Immunoprecipitation studies showed AQP1- Nav1.8 Na+ interaction, which was verified in live cells by single-particle tracking of quantum dot-labeled AQP1. Our results implicate the involvement of AQP1 in DRG neurons for the perception of inflammatory thermal pain and cold pain, whose molecular basis is accounted for, in part, by reduced Nav1.8-dependent membrane Na+ current. AQP1 is, thus, a novel target for pain management.
Excitability and conduction in neurons of dissociated ganglionic cell cultures.

Abstract The presence of 7S Nerve Growth Factor in cultures of dissociated 11-day chick embryo spinal sensory ganglia, besides permitting the survival of a sizable population of smaller neurons, affected the population of the larger ganglionic neurons by considerably accelerating the appearance and increasing the number of cells exhibiting cytotypic maturation, and also by markedly increasing the number of cells from which electrophysiological recordings could be obtained. Neurons and Schwann cells lay in a monolayer over the pluri-layered floor of capsule cells, and thus permitted optimal visibility of, and access to, cell somata and processes. Complete electrical maturation was displayed by most larger neurons by 8–10, and occasionally as early as 3, days in culture. Spike configurations were quite similar to those reported for other neurons, both in explant cultures and in vivo . A few cells excibited a complex spike segmentation, whose detailed analysis suggests a number of distinct electrogenic zones, probably located in different processes or process branches, and triggered across the soma membrane in a defined sequence. Neither spontaneous activity nor synaptic potentials have, thus far, been observed.
A semiparametric likelihood approach to joint modeling of longitudinal and time-to-event data.

Joint models for a time-to-event (e.g., survival) and a longitudinal response have generated considerable recent interest. The longitudinal data are assumed to follow a mixed effects model, and a proportional hazards model depending on the longitudinal random effects and other covariates is assumed for the survival endpoint. Interest may focus on inference on the longitudinal data process, which is informatively censored, or on the hazard relationship. Several methods for fitting such models have been proposed, most requiring a parametric distributional assumption (normality) on the random effects. A natural concern is sensitivity to violation of this assumption; moreover, a restrictive distributional assumption may obscure key features in the data. We investigate these issues through our proposal of a likelihood-based approach that requires only the assumption that the random effects have a smooth density. Implementation via the EM algorithm is described, and performance and the benefits for uncovering noteworthy features are illustrated by application to data from an HIV clinical trial and by simulation.
Crystallization kinetics of polyetheretherketone (PEEK) matrices

Differential scanning calorimetry (DSC) and the density gradient technique (DGT) were used to determine, both isothermally and dynamically, the crystallization kinetics of polyetheretherketone (PEEK). The data were analyzed by a model utilizing, for the first time, two crystal nucleation and growth processes which were observed experimentally in a typical Avrami plot of the isothermal data. Thus, by modeling the data as two separate Avrami type crystallization processes occurring in parallel, both isothermal and dynamic data could be predicted with the same model constants. The first process provided an Avrami exponent of 2.5 and an onset temperature of 320°C. The second process displayed an Avrami exponent of 1.5 and an onset temperature of 342°C. The validity of this dual mechanism crystallization model was proven in practice by predicting with best fit model constants, a wide range of crystallinities of both neat and carbon fiber-reinforced PEEK samples that had been made at different cooling rates from the melt.
This Little Piggy Went to Market: The Xenotransplantation and Xenozoonose Debate

New technologies are changing our lives radically and quickly. New biotechnologies are moving to commercial uses faster than government regulators or private citizens can monitor. This tension manifests itself in the current debates over xenotransplantation technologies in medicine. The possibility of removing cells, tissues, and organs from animals and transplanting them into human beings is startling and unnerving. Natural immunesystem barriers between species, and even between individuals within a species, are formidable. Typically, transplantation results in violent rejection and death of the grafted organ. But despite the natural barriers to transplantation, xenotransplantation aims specifically to overcome them. In this paper, I will discuss applications of xenograft technology, which raises clinical risks, ethical concerns, and policy issues. I conclude with a set of specific recommendations. As a recent letter to the journal Nature puts it, there is a “split between those who want to get it right, and those who want to get it right now.” No one knows what all the risks, benefits, and unintended consequences of xenotransplantation will be.
Strongly inequivalent representations and Tutte polynomials of matroids

We develop constructive techniques to show that non-isomorphic 3-connected matroids that are representable over a fixed finite field and that have the same Tutte polynomial abound. In particular, for most prime powers q, we construct infinite families of sets of 3-connected matroids for which the matroids in a given set are non-isomorphic, are representable over GF(q), and have the same Tutte polynomial. Furthermore, the cardinalities of the sets of matroids in a given family grow exponentially as a function of rank, and there are many such families.
Carbon source nutrition of rapamycin biosynthesis in Streptomyces hygroscopicus

Chemically-defined media were developed for rapamycin production byStreptomyces hygroscopicus. Thirty-five carbon sources were tested for their effect on production. Eight failed to support growth and seven appeared to repress or inhibit rapamycin formation. The best combination of two carbon sources were 2% fructose and 0.5% mannose. Acetate and propionate, which are known to contribute most of the carbon atoms of the lactone ring, were unsatisfactory for growth and/or rapamycin production.
Functional outcome after incomplete spinal cord injuries due to blunt injury

During a 3-year period, 19 patients with incomplete spinal cord injuries caused by blunt trauma were admitted to a single rural referral centre. The mean age was 50 years. Injury mechanisms included falls in eight, road traffic accidents in five, diving mishaps in two, and miscellaneous in four. The level of spinal cord injury was cervical in 11, thoracic in five, and thoracolumbar in three. Initial management included a standard high-dose methylprednisolone protocol for 24 h after injury in eight patients treated since May, 1990. Neurosurgical procedures were performed in 11 patients. There were three deaths, all in patients over 75 years of age with pulmonary complications. Of 16 survivors, 10 demonstrated significant functional neurological improvement by the time of hospital discharge, and 11 by late follow up. Complete recovery occurred in five of the survivors. Complications occurred in 11 patients, including pulmonary (nine), infectious (six), and gastrointestinal (three), but could not be associated specifically with the high-dose steroid protocol. In conclusion, incomplete spinal cord injuries after blunt injury were relatively uncommon in this setting. No significant increase in complications was observed after institution of the high-dose methylprednisolone protocol in May, 1990. However, pulmonary, gastrointestinal, and infectious complications were common. Of the 16 survivors, 11 demonstrated significant functional improvement. Mortality appeared to be related to advanced age and to pulmonary complications.
A fast non-conforming DP-FETI domain decomposition method for the solution of large EM problems

The paper presents an efficient finite element based domain decomposition method (DDM) (Benamou, J-D and Despre/spl grave/s, B., J Comput. Phys., vol.136, p.68-82. 1997; Stupfel, B. and Mognot, M., IEEE Trans. Antennas Propagat., vol.48, p.653-60, 2000) for the analysis of large electromagnetic problems with a finite number of different building blocks. Such problems arise in important engineering applications such as antenna arrays, frequency selective surfaces, photonic crystals and metamaterials. The method is general enough to analyze arbitrary geometries. The proposed method is based on three key ingredients: (a) the optimized Robin transmission condition across interfaces; (b) the new mortar method for nonconforming triangulations; (c) a fast dual-primal finite element tearing and interconnecting (DP-FETI) algorithm similar to that of Wolfe, C.T. et al. (see IEEE Trans. Antennas Propagat., vol.48, no.2, p.278-84, 2000).
Non-uniform noise spatial distribution in CT myocardial perfusion and a potential solution: statistical image reconstruction

Myocardial perfusion scans are an important tool in the assessment of myocardial viability following an infarction. Cardiac perfusion analysis using CT datasets is limited by the presence of so-called partial scan artifacts. These artifacts are due to variations in beam hardening and scatter between different short-scan angular ranges. In this research, another angular range dependent effect is investigated: non-uniform noise spatial distribution. Images reconstructed using filtered backprojection (FBP) are subject to this effect. Statistical image reconstruction (SIR) is proposed as a potential solution. A numerical phantom with added Poisson noise was simulated and two swines were scanned in vivo to study the effect of FBP and SIR on the spatial uniformity of the noise distribution. It was demonstrated that images reconstructed using FBP often show variations in noise on the order of 50% between different time frames. This variation is mitigated to about 10% using SIR. The noise level is also reduced by a factor of 2 in SIR images. Finally, it is demonstrated that the measurement of quantitative perfusion metrics are generally more accurate when SIR is used instead of FBP.
A LABORATORY INVESTIGATION OF SOCIAL CLASS AND NATIONAL DIFFERENCES IN HELPING BEHAVIOR

Etude au laboratoire des differences dans le comportement d'entraide selon la nationalite et la classe sociale. —Le meme plan d'experience a ete realise a Madison (Wisconsin) et a Oxford (Angleterre) pour determiner si les adolescents appartenant a differentes classes sociales obeissent aux memes principes dans l'aide qu'ils apportent aux camarades qui dependent d'eux. Les adolescents de Madison appartiennent a des families de la classe moyenne ((I) petits industriels, commercants, artisans, (2) employes de bureau) ou de la classe ouvriere. Les adolescents d'Oxford proviennent seulement de la classe moyenne des employes ou de la classe ouvriere. Dans les deux echantillons, le sujet est d'abord amene a croire qu'un camarade lui a apporte beaucoup ou peu d'aide quand lui-meme en avait besoin pour gagner un concours. Dans la phase suivante qui est supposee impliquer un concours sans rapport avec le premier, le sujet a l'occasion d'aider la personne qui a ete son partenaire ou une tout autre personne. Les resultats de Madison montrent, conformement a l'hypothese, que les sujets appartenant a la classe des petits industriels, commercants et artisans ont plus tendance a agir selon une conception de simple echange. Plus que les adolescents de la classe des employes ou de la classe ouvriere, ils croient que les gens s'attendent a ce qu'ils travaillent dur pour une autre personne seulement dans la mesure ou ils ont eux-memes beneficie d'une telle situation et ils font des efforts au profit du camarade qui depend d'eux, dans l'attente d'une reciprocite de type « donner et recevoir ». A Oxford, les sujets de la classe ouvriere sont plus orientes vers la reciprocite que les fils d'employes. Quelques difficultes d'ordre methodologique sont discutees, mais l'A. pense que les tentatives actuelles pour analyser l'interaction sociale en termes d'echange economique ne peuvent etre egalement appliquees a toutes les classes sociales.
The effect of administration time on malformations induced by three anticonvulsant agents in C57BL/6J mice with emphasis on forelimb ectrodactyly.

Exposure of C57BL/6J mice to three anticonvulsant derivatives, namely, dimethadione, sodium valproate, and sodium diphenylhydantoin, each induced postaxial forelimb ectrodactyly. The agents were administered at gestational days 9, 9 1/3, 9 2/3, and 10. It was determined that administration at day 9 2/3 induced the highest percentage of forelimb ectrodactyly for each of the three agents. The forelimb ectrodactyly response in the C57BL/6J strain was compared with the A/J strain (Collins et al., Teratology, 41:61–70, 1990); it was found that the C57BL/6J strain was more sensitive to dimethadione and the A/J strain was more sensitive to diphenylhydantoin and sodium valproate. The position of vertebral defects induced by sodium valproate correlated with the time of drug administration. The overall syndrome of malformations induced by the three anticonvulsant agents was relatively similar in the two mouse strains and differed between each of the anticonvulsant agents.
Caring for the Patient With AIDS

ACQUIRED immunodeficiency syndrome (AIDS) is emerging as one of the most dreadful of human diseases. The way in which the disease recurrently savages its victims before killing them is now well known. So are the feelings of profound depression, anger, loneliness, and hopelessness so often seen in those afflicted with this miserable malady. So too is the fear, sometimes bordering on panic, felt by most of society regarding AIDS. Less well recognized are the troublesome feelings often harbored by health professionals that tend to interfere with the care of patients with AIDS. The way a physician or a nurse feels about a patient is often important in determining the quality of the outcome of a medical transaction. Communicating one's unconditional positive regard for a patient has long been one of the healer's most powerful therapeutic tools. Science has not been able to quantitate the precious positive things that seem to
Cytologic subtypes of grade 3 follicular lymphoma

Histologic grading of follicular lymphoma poses a dilemma. On one hand, there are data to support the notion that histologic grade (no matter what system of grading is used) correlates to some extent with clinical outcome. Furthermore, those patients with the highest grade of follicular lymphoma (
Financial Restatements, Audit Fees, and the Moderating Effect of CFO Turnover

SUMMARY: We examine post‐restatement audit fees and executive turnover for a sample of firms that restated their 2003 financial statements. We investigate and find evidence that audit fees are higher for restatement firms compared with a matched‐pair control group of non‐restatement firms. We propose that the higher audit fees reflect a cost of both an increase in perceived audit risk and a loss of organizational legitimacy. Prior literature suggests that changing top management is a response to a legitimacy crisis; thus we expect to find that executive turnover moderates the positive relationship between restatement and audit fees. Our results indicate that a change in CFO for a restatement firm moderates the increased audit fee, but a change in CEO does not.
Non-Contact Measurements Of Refractive Index And Surface Curvature

A simple system geometry using a low power laser has been designed to measure the surface curvature of a lens or a mirror or the refractive index of a slab of a transparent material by using the Fresnel reflection from its surfaces. By comparing our measurements of the surface curvature to those using a precision spherometer, we found this method accurate to ±0.1 mm for curvatures from 25 to 75 mm. If the thickness of a parallel plate can be measured, this technique can determine the refractive index of the plate without resorting to demounting or cutting a sample to be measured. Measurements of fused and crystalline quartz flats determined the refractive indices of the samples to ±0.001. The application of this technique to in situ measurements of optical systems and its limitations will be discussed.
The radiation therapy of early stage cutaneous T-cell lymphoma

Abstract Results of different radiotherapy schedules used for early stage (T1-2, N0-1, M0) cutaneous T-cell lymphoma (CTCL) are compared in a series of 45 patients (22 patients treated with high dose total skin electron beam therapy (TSEB) with curative intent, 18 patients treated with palliative radiotherapy, and 5 patients treated with high dose local electron beam). At 3, 5, and 10 years after diagnosis the high dose TSEB treatment group had a probability of overall survival of 91%, 86%, and 75%, respectively, compared with 94%, 88%, and 88% for the palliative treatment group. The complete response (CR) rate for the high dose TSEB treatment group was 82% (1822), compared with a 57% (47) complete response rate for seven patients in the palliative group who received low dose TSEB (
Rules of probability in quantum mechanics

We show that the quantum mechanical rules for manipulating probabilities follow naturally from standard probability theory. We do this by generalizing a result of Khinchin regarding characteristic functions. From standard probability theory we obtain the methods usually associated with quantum theory; that is, the operator method, eigenvalues, the Born rule, and the fact that only the eigenvalues of the operator have nonzero probability. We discuss the general question as to why quantum mechanics seemingly necessitates different methods than standard probability theory and argue that the quantum mechanical method is much richer in its ability to generate a wide variety of probability distributions which are inaccessibe by way of standard probability theory.
Flow attachment to solid surfaces: The Coanda effect

The phenomenon of flow attachment to solid surfaces, occurring with both liquids and gases, is the long-known though inadequately understood Coanda effect. A flow visualization study was made using a birefringent milling yellow dye solutions flowing over a deflection surface consisting of flat plates. A two-dimensional flow channel with transparent side walls was used. Photographic observations of the development of the Coanda effect reveal the method of flow attachment and confirm a number of literature predictions. One of the most interesting of these phenomena is the existence of a well defined mixing region along the deflection surface. A simplified model of the flow field has been proposed in order to described the mechanism governing the Coanda effect. The model is supported by experimental data consisting of pressure profiles obtained along the deflection surface and secondary flow entrainment measurements.
Effect of steroids or tissue preceding on edema and tissue thermal coagulation after CO2 laser impact

The carbon dioxide laser is frequently used in laryngeal microsurgery. Some surgeons have empirically used preoperative steroids or precooling with ice prior to laser impact to limit the resultant tissue thermal coagulation and/or edema. An animal model was designed to quantitatively test these effects. Depillated areas of rat skin were exposed to a CO2 beam of 1 mm diameter at 15 W for 0.1 sec after either administration of Decadron (0.25 mg/kg) immediately prior to impact or precooling more than 10oC below basal body temperature. Measurement of edema was quantitated as extravasation of Evan's blue dye that had been injected intravenously. Tissue thermal coagulation was measured on hematoxylin and eosin stained histologic sections. In comparison to controls, statistically significant reduction in edema was seen only at the 24 hour time period after laser exposure for the steroid group (P<.002) but not for the precooling group. Tissue thermal coagulation was significantly smaller for both the steroid and the ice group (P < .006 and P < .001, respectively) when compared to controls. © 1992 Wiley-Liss, Inc.
The Dedekind-Mertens lemma and the contents of polynomials

Let R be a commutative ring, let X be an indeterminate, and let g E R[X]. There has been much recent work concerned with determining the Dedekind-Mertens number P,R(g)=min{k E N I cR(f)k-lcR(fg) = CR(f)kCR(g) for all f E R[X]}, especially on determining when [LR(g) = 1. In this note we introduce a universal Dedekind-Mertens number WUR(g), which takes into account the fact that pus(g) < deg(g) + 1 for any ring S containing R as a subring, and show that uPR(g) behaves more predictably than PRO(g).
Dissolution of aragonite, Mg-calcite, and calcite in the North Atlantic Ocean

Direct measurements indicate that rapid dissolution of aragonite and Mg-calcite in the central Sargasso Sea begins 1,000 m deeper (3,500 and 4,400 m, respectively) than observed carbonate dissolution depths for these two minerals. Thus, whereas the rate of dissolution appears to be controlled by the degree of saturation, the carbonate content of sediment is also related to other oceanographic parameters.
Contrasting modes of photosynthetic enzyme regulation in oxygenic and anoxygenic prokaryotes

Enzymes that are regulated by the ferredoxin/thioredoxin system in chloroplasts — fructose-1,6-bisphosphatase (FBPase), sedoheptulose-1,7-bisphosphatase purified from two different types of photosynthetic prokaryotes (cyanobacteria, purple sulfur bacteria) and tested for a response to thioredoxins. Each of the enzymes from the cyanobacterium Nostoc muscorum, an oxygenic organism known to contain the ferredoxin/thioredoxin system, was activated by thioredoxins that had been reduced either chemically by dithiothreitol or photochemically by reduced ferredoxin and ferredoxin-thioredoxin reductase. Like their chloroplast counterparts, N. muscorum FBPase and SBPase were activated preferentially by reduced thioredoxin f. SBPase was also partially activated by thioredoxin m. PRK, which was present in two regulatory forms in N. muscorum, was activated similarly by thioredoxins f and m. Despite sharing the capacity for regulation by thioredoxins, the cyanobacterial FBPase and SBPase target enzymes differed antigenically from their chloroplast counterparts. The corresponding enzymes from Chromatium vinosum, an anoxygenic photosynthetic purple bacterium found recently to contain the NADP/thioredoxin sytem, differed from both those of cyanobacteria and chloroplasts in showing no response to reduced thioredoxin. Instead, C. vinosum FBPase, SBPase, and PRK activities were regulated by a metabolite effector, 5′-AMP. The evidence is in accord with the conclusion that thioredoxins function in regulating the reductive pentose phosphate cycle in oxygenic prokaryotes (cyanobacteria) that contain the ferredoxin/thioredoxin system, but not in anoxygenic prokaryotes (photosynthetic purple bacteria) that contain the NADP/thioredoxin system. In organisms of the latter type, enzyme effectors seem to play a dominant role in regulating photosynthetic carbon dioxide assimilation.
Surgery for obesity.

As were most types of gastrointestinal surgery, antiobesity surgery was dominated by the development of laparoscopic techniques during the last decade. The feasibility of performing any primary antiobesity operation safely laparoscopically was convincingly demonstrated during the last 2 years. This represents a significant continued improvement in the perioperative safety of "bariatric" surgery. However, antiobesity surgery entails very much more than technique. Unfortunately, little progress has been made in optimizing patient selection, improving follow-up, and devising strategies for reoperative antiobesity surgery. The latest publications in the field are mainly confirmatory, demonstrating durable medically significant weight loss resulting in comorbidity reduction with increased life expectancy. The most interesting contribution of this surgery is provision of "experimental models" using gastrointestinal physiology to study the pathophysiology of obesity and undernutrition by guaranteeing substantial weight loss maintained long-term. It is unfortunate that surgery for obesity is seriously underutilized.
The life cycle of alternative agricultural research

The acceptance and utility of alternative agricultural research can be enhanced by better incorporating social sciences and issues and by broadening its scope to the entire food system rather than focusing only on food production. Researchers have made strong contributions in developing and evaluating alternative agricultural technologies, but research attention also is needed to articulate strategies for synthesizing those technologies into coherent strategies, to examine the social effects of different scenarios, and to create better decisionmaking processes for ensuring broad-based knowledgeable participation in the choices among alternative strategies. Research that addresses human needs beyond food and fiber will help build truly alternative and desirable agricultural systems.
Extra-Esophageal Manifestations of Gastroesophageal Reflux Disease: Diagnosis and Treatment

Gastroesophageal reflux disease (GERD) is a common disease that is often diagnosed based on typical symptoms of heartburn and regurgitation. In addition to these more classic manifestations, GERD is increasingly associated with extra-esophageal symptoms, including chronic cough, asthma, laryngitis, and dental erosions. Due to the poor sensitivity of endoscopy and pH monitoring, and the poor specificity of laryngoscopy, empiric therapy with proton pump inhibitors (PPIs) is now considered the initial diagnostic step in patients suspected of having GERD-related symptoms. For those who improve with PPIs, GERD is the presumed etiology, but for those who remain unresponsive to such therapy, further diagnostic testing with impedance/pH monitoring may be necessary in order to exclude refractory acid or weakly acid reflux. In those with normal test results despite PPI therapy and continued symptoms, causes other than GERD may be pursued. Recent data suggest that in patients with extra-esophageal symptoms, objective findings of moderate-sized hiatal hernia and moderate reflux on pH testing may predict response to acid suppressive therapy. PPI-unresponsive patients usually have causes other than GERD for their extra-esophageal symptoms and continued PPI therapy in this group is not recommended.
Nutrient intakes and adenocarcinoma of the esophagus and distal stomach.

We studied the relationship between nutrient intakes and adenocarcinoma of the esophagus and distal stomach among 124 esophageal adenocarcinoma cases, 124 distal stomach cancer cases, and 449 controls in a population-based case-control study in eastern Nebraska. The residual method was used to adjust nutrient intake quartiles or tertiles for energy intake. We observed significant inverse associations with risk of esophageal adenocarcinoma for dietary intakes of total vitamin A [highest vs. lowest quartile, multivariate odds ratio (OR) = 0.5, P for trend = 0.05], β-cryptoxanthin (OR = 0.5, P = 0.05), riboflavin (OR = 0.5, P = 0.01), folate (OR = 0.5, P = 0.03), zinc (OR = 0.5, P = 0.05), dietary fiber (OR = 0.5, P = 0.05), protein (OR = 0.5, P = 0.02), and carbohydrate (OR = 0.4, P = 0.02). For distal stomach cancer, only vitamin C (OR = 0.6, P = 0.04), dietary fiber (OR = 0.4, P = 0.007), and carbohydrate (OR = 0.4, P = 0.004) were inversely associated with risk. Our analyses showed significant interactio...
Determinants of role-sharing behavior: A study of egalitarian couples

This article reports on an intensive study of couples engaged in a deliberate attempt to institute complete sex-role equality within their marriages (not to be confused with the dual-career pattern, where couples merely share an interest in employment). Because role-sharing couples are so uncommon, a strategic nonrandom sampling technique appropriate for generating insights about emerging lifestyles was employed to locate couples for study. Several factors related to the adoption of a shared role marital arrangement are described. These are grouped into two categories: (1) background and personality characteristics of role-sharing individuals and (2) contemporary factors in the couples' social environment which facilitate role-sharing. The article ends with a discussion of the possible reasons for the increased incidence of role-sharing.
Correlates of unplanned and unwanted pregnancy among African-American female teens

Abstract Background Evidence suggests that unplanned/unwanted pregnancy may be an important antecedent of negative birth outcomes, such as low birth weight. This study identified correlates of perceiving a current pregnancy as both unplanned and unwanted among unmarried African-American adolescents aged 14–20 years. Methods One hundred seventy pregnant adolescents were recruited during their first prenatal visit. Adolescents completed a face-to-face interview administered in private examination rooms. Adolescents also completed an in-depth self-administered survey. Measures were selected based on two potential influences: (1) relationships with boyfriends and (2) parent/family involvement. Age and parity were also assessed. Contingency table analyses were used to identify significant bivariate associations. Correlates achieving bivariate significance were entered into a forward stepwise logistic regression model. Results Pregnancy was reported as unplanned and unwanted by 51.2% of the study population. In a multivariate analysis, adolescents indicating lower levels of parental involvement were about twice as likely (adjusted odds ratio [AOR]=2.05; 95% confidence interval [CI], 1.1–3.9, p p p p =0.052). Conclusions Findings provide initial evidence for specifically targeting intensified prenatal care programs to teens perceiving their pregnancy as unplanned and unwanted.
A Legal Perspective on Unanswered Questions in Tax Research

INTRODUCTION The goal of this paper is to provide an interdisciplinary perspective on some of the important topics that accounting researchers might take on. In one sense, we need to be very careful in advising non-legal entry academics on questions of interest to lawyers and economists. The most important advice might be to first succeed within the traditional boundaries of your field (e.g., finish your Ph.D., obtain an academic position, and earn tenure) before worrying about branching out. On the other hand, an interdisciplinary focus might help young academics find questions that are new to a field and apply new ways of thinking to help answer them. Before getting to the questions, we should start with a few caveats. First, researchers in any field should always think in terms of comparative advantage: ‘‘What skill do I bring to the table that others may not have that can help answer a question?’’ The three fields most central to taxation—economics, accounting, and law—each have unique comparative advantages. Economists bring a mathematically based theoretical foundation to their work. This foundation has several advantages. First, a rigorous mathematical foundation often helps to illustrate aspects of the problem that would not otherwise be noticed. An example of this approach in action is the optimal tax literature: while intuition suggests that the proper tax rate schedule must balance redistribution and disincentives to work, the optimal tax literature illustrates how subtle this balance is. Second, a mathematical foundation also forces basic assumptions to be stated explicitly (although often less explicitly than one might hope because assumptions are often embedded in utility functions, production functions, and the like). Finally, a rigorous mathematical approach helps to generate well-defined testable hypotheses, facilitated by a set of statistical tools used in empirical work. Lawyers possess a detailed knowledge about how the tax law actually works. Lawyers often know about interactions and imperfections that are not captured in economics models, or that cannot be easily stated in mathematical terms. Indeed, it is standard among tax lawyers to think that the economists’ models are hopelessly simplistic, notwithstanding the pages of detailed (and often impenetrable) math. Lawyers often use their institutional knowledge to write articles about how best to design the ‘‘plumbing’’ of the tax system— how best (within the legal framework) to fit the various pieces together, and how to get the various rules to properly interact. Such work is extremely important, but it rarely focuses on the big issues. At other times, however, lawyers’ understanding of broad legal principles
Simvastatin Induces Heme Oxygenase-1 A Novel Mechanism of Vessel Protection

Background— Evidence from experimental and clinical studies indicates that statins can protect the vessel wall through cholesterol-independent mechanisms. The “pleiotropic” effects include the prevention of inflammation and proliferation of vascular cells. Here, we studied whether heme oxygenase-1 (HO-1), an important cytoprotective molecule, is induced by simvastatin and the role of HO-1 in the pleiotropic effects of simvastatin. Methods and Results— Human and rat aortic smooth muscle cells treated with simvastatin showed an elevated level of HO-1 for up to 24 hours. The induction of HO-1 by simvastatin was not found in cultured endothelial cells and macrophages. Injecting C57BL/6J mice intraperitoneally with simvastatin increased the level of HO-1 in vascular SMCs (VSMCs) in the tunica media. Treating VSMCs with zinc protoporphyrin, an HO-1 inhibitor, or HO-1 small interfering RNA (siRNA) blocked the antiinflammatory effect of simvastatin, including the inhibition of nuclear factor-κB activation and nit...
Inducible nitric oxide synthase gene deficiency counteracts multiple manifestations of peripheral neuropathy in a streptozotocin-induced mouse model of diabetes

Aims/hypothesis Evidence for the importance of peroxynitrite, a product of superoxide anion radical reaction with nitric oxide, in peripheral diabetic neuropathy is emerging. The role of specific nitric oxide synthase isoforms in diabetes-associated nitrosative stress and nerve fibre dysfunction and degeneration remains unknown. This study evaluated the contribution of inducible nitric oxide synthase (iNOS) to peroxynitrite injury to peripheral nerve and dorsal root ganglia and development of peripheral diabetic neuropathy.
Acquisition of a temporal discrimination by human subjects

Acquisition of a button-pressing response for three values of a DRL schedule was observed for 12 human Ss under instructions to win as many points, indicated by a flashing light, as possible. All Ss showed a rapid development of a temporal discrimination and a rapid transition from DRL 3 sec. to DRL 6 sec. to DRL 10 sec. Several characteristics of stable DRL behavior were observed to be similar to those found with animal Ss.
Design of a Tele-Operated Robot for the Maintenance of Boiler Hoppers in Electric Power Plants

The design of a novel tele-robotic device for clearing undesirable residues from boiler hoppers in electric power plants is presented. A key aspect of the problem that drives the design process is the fact that the environment inside the hopper is harsh and unstructured. This has led to a robot design which has all its sophisticated mechanical and control hardware located outside the hopper access port. Results from experimental testing of a prototype are included.
Transbronchial Lung Biopsy: Can Specimen Quality Be Predicted at the Time of Biopsy?

Study objectives To determine the bronchoscopist's ability to predict specimen quality at the time of transbronchial biopsy and to determine the influence of biopsy specimen size and alveolar content on diagnostic value. Design Prospective, blinded, observational analysis. Setting Tertiary care academic hospital-based pulmonary practice. Patients Forty-three adult patients who underwent transbronchial lung biopsy. Interventions Each of 170 biopsy specimens was rated as to likelihood of containing diagnostic tissue, size and ability to float, tissue types present, number of alveoli, and pathologic diagnosis. Results Fifteen percent of biopsy specimens were small and 40% were large. Seventy-six percent of specimens floated; 61.8% of the 170 biopsy specimens contained abnormal lung tissue; and 14.7% of individual specimens were diagnostic. Fifty-two percent of specimens contained >20 alveoli. Larger biopsy specimens were more likely to contain diagnostic tissue (r=0.29, p=0.001). Cup forceps retrieved smaller pieces of tissue (p=0.007) and were less likely to obtain diagnostic tissue (p=0.06). Physician ratings of specimen quality (mean±SD) did not differ between specimens containing normal and abnormal tissue (5.98±2.3 vs 5.46±5.5; p=0.24) or between specimens containing diagnostic vs nondiagnostic tissue (5.56±2.5 vs 6.25±2.1; p=0.14). Specimens that floated were no more likely to be diagnostic or abnormal than specimens that sank (p Conclusions Physician estimate of biopsy specimen quality and the float sign are not helpful in predicting that the biopsy specimen contains abnormal or diagnostic tissue. Diagnostic biopsy specimen will likely be obtained if the size of the specimen fills the forceps, 2 to 4 biopsies are performed, and toothed forceps are used.
Dynamics of collaborative document rating systems

The rise of social media sites, such as blogs, wikis, Digg and Flickr among others, underscores a transformation of the Web to a participatory medium in which users are actively creating, evaluating and distributing information. The social news aggregator Digg allows users to submit links to and vote on news stories. Like other social media sites, Digg also allows users to designate others as "friends" and easily track friends' activities: what new stories they submitted, commented on or liked. Each day Digg selects a handful of stories to feature on its front page. Rather than rely on the opinion of a few editors, Digg aggregates opinions of thousands of its users to decide which stories to promote to the front page. We construct a mathematical model to study how collaborative rating and promotion of news stories emerges from independent decisions made by many users. The model takes into account user behavior: e.g., whether they read stories on the front page or through the Friends interface. Solutions of the model qualitatively reproduce the observed dynamics of votes received by actual stories on Digg.Digg also ranks users according to how successful they are in getting their stories promoted to the front page. We create a model that describes how a user's rank changes in time as he gets more stories to the front page and becomes more influential in the community. We find qualitative agreement between predictions of the model and the evolution of rank for Digg users.The Digg model of allowing users to collectively evaluate how interesting the news stories are can be generalized to collaborative evaluation of the quality of information. Mathematical analysis can be used as a tool to explore different voting methods to select the most effective one before the method is ever implemented in a real system.
Density estimation for linear processes

LetXt, ...,Xn be random variables forming a realization from a linear process\(X_t = \sum\limits_{r = 0}^\infty {g_r Z_{t - r} } \) where {Zt} is a sequence of independent and identically distributed random variables with E|Zt| 0, andgr→0 asr→∞ at some specified rate. LetX1 have a probability density functionf. It is then established that for every realx, the standard kernel type estimator\(\hat f_n (x)\) based onXt (1≦t≦n) is, under some general regularity conditions, asymptotically normal and converges a.s. tof(x) asn→∞.
Free H2 Rotation vs Jahn–Teller Constraints in the Nonclassical Trigonal (TPB)Co–H2 Complex

Proton exchange within the M–H_2 moiety of (TPB)Co(H_2) (Co–H_2; TPB = B(o-C_6H_4PiPr_2)_3) by 2-fold rotation about the M–H_2 axis is probed through EPR/ENDOR studies and a neutron diffraction crystal structure. This complex is compared with previously studied (SiP^(iPr)_3)Fe(H_2) (Fe–H_2) (SiP^(iPr)_3 = [Si(o-C_6H_4PiPr_2)_3]). The g-values for Co–H_2 and Fe–H_2 show that both have the Jahn–Teller (JT)-active ^2E ground state (idealized C_3 symmetry) with doubly degenerate frontier orbitals, (e)^3 = [|m_L ± 2>]^3 = [x^2 – y^2, xy]^3, but with stronger linear vibronic coupling for Co–H_2. The observation of ^1H ENDOR signals from the Co–HD complex, ^2H signals from the Co–D_2/HD complexes, but no ^1H signals from the Co–H_2 complex establishes that H_2 undergoes proton exchange at 2 K through rotation around the Co–H_2 axis, which introduces a quantum-statistical (Pauli-principle) requirement that the overall nuclear wave function be antisymmetric to exchange of identical protons (I = 1/2; Fermions), symmetric for identical deuterons (I = 1; Bosons). Analysis of the 1-D rotor problem indicates that Co–H_2 exhibits rotor-like behavior in solution because the underlying C_3 molecular symmetry combined with H_2 exchange creates a dominant 6-fold barrier to H_2 rotation. Fe–H_2 instead shows H_2 localization at 2 K because a dominant 2-fold barrier is introduced by strong Fe(3d)→ H_2(σ^*) π-backbonding that becomes dependent on the H_2 orientation through quadratic JT distortion. ENDOR sensitively probes bonding along the L_2–M–E axis (E = Si for Fe–H_2; E = B for Co–H_2). Notably, the isotropic ^1H/^2H hyperfine coupling to the diatomic of Co–H_2 is nearly 4-fold smaller than for Fe–H_2.