cssi/SciSciGPT-SciSciNet huggingface dataset:
Silicon and gallium arsenide field-effect transistors with Schottky-barrier gate

Abstract Field-effect transistors with Schottky-barrier gates have been produced using epitaxial layers of n-type silicon on p-type substrates, and n-type gallium arsenide on semi-insulating substrates. Some simple design considerations are presented and the fabrication processes are discussed in detail. Comparisons are made between two different device geometries and between silicon and gallium arsenide devices.
Altered Myofilament Targeting with Differential PKCδ Activation

Post-translational modification of troponin (Tn) and other myofilament proteins by protein kinase C (PKC) isozymes plays a prominent role in regulating myocardial contraction. Conventionally, phosphorylation of conserved serine and threonine residues in the c-terminus activates PKCdelta, a novel calcium independent isozyme. Several recent investigations including our work (Sumandea et al. J Biol Chem. 2008;283(33):22680-9) have led to the probability of alternative activation of PKCdelta by tyrosine residue phosphorylation through a redox-sensitive mechanism. Previous work determined PKCdelta phosphorylation of adult, cardiac rat myocytes in vitro reduces skinned myocyte tension generation at sub-maximum with no change at maximum calcium concentrations. Conversely, tyrosine phosphorylated PKCdelta reduces the maximal Ca-activated tension with no decrease in submaximal tension production. Biochemical data indicated a shift in TnI residue targeting with tyrosine phosphorylated PKCdelta from exclusive phosphorylation of S23/24, to include T144. To test the hypothesis that kinase targeting to TnI-T144 was sufficient to blunt effects of conventional PKCdelta targeting to TnI-S23/24, myofibrillar function was assessed following exchange of TnI with pseudo-phosphorylated residues. Pseudo-phosphorylation at residues S23/24 decreased Ca-sensitivity of force production and increased tension cost. Pseudo-phosphorylation at TnI-144 had minimal affect on mechanical parameters. However, the combination of pseudo-phosphorylations at residues S23/24 and T144 did not successfully blunt desensitization. Further biochemical assessments have determined differential PKCdelta targeting to multiple myofibrillar proteins other than TnI. Further elucidation of alternative PKCdelta signaling to the myofilments is on-going. Our results suggest Src-dependent phosphorylation of PKCdelta constitutes an alternative mechanism that allows for stimulus-specific PKCdelta ezymology and myofibrillar targeting within the myocardium.
Sensitization of group III and IV muscle afferents in the mouse after ischemia and reperfusion injury.

Abstract Ischemic myalgia is a unique type of muscle pain in the patient population. The role that discrete muscle afferent subpopulations play in the generation of pain during ischemic events, however, has yet to be determined. Using 2 brachial artery occlusion models to compare prolonged ischemia or transient ischemia with reperfusion of the muscles, we found that both injuries caused behavioral decrements in grip strength, as well as increased spontaneous pain behaviors. Using our ex vivo forepaw muscles, median and ulnar nerves, dorsal root ganglion, and spinal cord recording preparation, we found after both prolonged and transient ischemia that there was a significant increase in the number of afferents that responded to both noxious and non-noxious chemical (lactate, adenosine triphosphate, varying pH) stimulation of the muscles compared to uninjured controls. However, we found an increase in firing to heat stimuli specifically in muscle afferents during prolonged ischemia, but a distinct increase in afferent firing to non-noxious chemicals and decreased mechanical thresholds after transient ischemia. The unique changes in afferent function observed also corresponded with distinct patterns of gene expression in the dorsal root ganglia. Thus, the development of ischemic myalgia may be generated by unique afferent-based mechanisms during prolonged and transient ischemia. Perspective This study analyzed the response properties of thinly myelinated group III and unmyelinated group IV muscle afferents during prolonged and transient ischemia in addition to pain behaviors and alterations in DRG gene expression in the mouse. Results suggest that mechanisms of pain generation during prolonged ischemia may be different from ischemia/reperfusion.
Non-stationary structural model with time-varying demand elasticities

Abstract The paper considers local linear regression of a time series model with non-stationary regressors and errors. Asymptotic property of the local linear estimator is derived under a new dependence measure of non-stationary time series. We apply the local linear regression method to estimate the “time-varying” coefficients of an economic-causal model for the industrial sector of the U.S. economy. Nonparametric bootstrap test on the time-varying coefficients strongly suggests that the price/income elasticities of the U.S. durable goods demand are time-varying.
Second-order accurate interface- and discontinuity-aware diffusion solvers in two and three dimensions

A numerical scheme is developed for two- and three-dimensional time-dependent diffusion equations in numerical simulations involving mixed cells. The focus of the development is on the formulations for both transient and steady states, the property for large time steps, second-order accuracy in both space and time, the correct treatment of the discontinuity in material properties, and the handling of mixed cells. For a mixed cell, interfaces between materials are reconstructed within the cell so that each of resulting sub-cells contains only one material and the material properties of each sub-cell are known. Diffusion equations are solved on the resulting polyhedral mesh even if the original mesh is structured. The discontinuity of material properties between different materials is correctly treated based on governing physics principles. The treatment is exact for arbitrarily strong discontinuity. The formulae for effective diffusion coefficients across interfaces between materials are derived for general polyhedral meshes. The scheme is general in two and three dimensions. Since the scheme to be developed in this paper is intended for multi-physics code with adaptive mesh refinement (AMR), we present the scheme on mesh generated from AMR. The correctness and features of the scheme are demonstrated for transient problems and steady states in one-, two-, and three-dimensional simulations for heat conduction and radiation heat transfer. The test problems involve dramatically different materials.
PARADIGMS, POLICIES, AND PEOPLE: EXPLORING THE LINKAGES BETWEEN NORMATIVE BELIEFS, PUBLIC POLICIES AND UTILITY CONSUMER PAYMENT PROBLEMS

This article takes a step toward unifying normative and empirical policy analysis by examining the convergence of societal metatheories, public policy models, and empirical data on consumers. It begins with the premise that policies rest on a foundation of normative beliefs or metatheories that, in turn, put boundaries around the possible and give social meaning to the policies and programs that flow from them. The interaction of social metatheories about poverty and existing policies to deal with people with utility payment problems is examined. The article continues with the idea that good policy arguments are supported with empirical data and factual evidence. An empirical cluster analysis of a representative sample of consumers provides a basis for identifying the extent to which the empirical clusters conform to any or all of the metatheory-policy linkages. The ultimate message is that theory and practice ought to demarcate where they are deductively metaphysical, based on beliefs about a subject, where they are inductively empirical, based on objective measurements relevant to the situation to which applied, and where a mixed approach is used. Linkage of the three types of information allows policy research to identify options in light of the values and metatheories on which they are based and the objective characteristics and effects on their objects of action. The implications are that when policies are based on beliefs that reflect only a part of empirical reality, implementation may fail or be inefficient and ineffective.
Environmental effects on the near ultraviolet absorption and emission spectra of benzene in a crystalline matrix of cyclohexane

Abstract The emission and absorption of benzene in a crystalline matrix of cyclohexane has been found to be markedly dependent on the manner in which the sample is frozen. Cyclohexane is known to undergo a solid-solid phase transition from a cubic to a monoclinic crystal structure as the temperature is lowered past 186°K. The spectrum observed for low benzene concentration fast-frozen samples is attributed to benzene molecules occluded in the cubic cyclohexane lattice; the spectrum observed for low benzene concentration slowly frozen samples is attributed to benzene molecules occluded in the monoclinic cylclohexane lattice. With increasing benzene concentration small crystals of essentially pure benzene segregate out upon freezing, and their emission or absorption becomes the dominant contribution to the spectrum. Vibrational analyses of all three absorption spectra are made, assuming that the D6h selection rules apply to a high degree, being slightly modified by environmental perturbation.
Limitations of therapy and a guarded prognosis in an American cohort of Takayasu arteritis patients.

Objective To describe the clinical, laboratory, and radiographic manifestations of Takayasu arteritis (TA) in a cohort from the US, evaluate the response to interventions, remission and relapse rates, and disease progression, and compare these observations with those from other cohorts in the US, Japan, India, Italy, and Mexico. Methods Seventy-five patients were retrospectively studied using a uniform database that included clinical, laboratory, and imaging data. Vascular imaging studies were performed at least yearly to monitor disease progression. Results Common manifestations at disease onset included loss or asymmetry of pulses (57%), limb blood pressure discrepancy (53%), and bruits (53%). Eleven percent of patients were asymptomatic prior to disease diagnosis. Initial angiographic studies showed aortic abnormalities in 79% of patients and frequent involvement of the subclavian (65%) and carotid (43%) arteries. Ninety-three percent of longitudinally followed patients attained disease remission of any duration, but only 28% sustained remission of at least 6 months' duration after prednisone was tapered to <10 mg daily. Both angioplasty and vascular surgery were initially successful, but recurrent stenosis occurred in 78% of angioplasty and 36% of bypass/reconstruction procedures. More than two-thirds of patients had difficulty performing routine daily activities and approximately one-fourth of all patients were unable to work. Our cohort was similar to the National Institutes of Health, Italian, Japanese, and Mexican cohorts in terms of the predominance of female subjects and disease manifestations, but differed from the Indian cohort in that the latter group had a higher frequency of male subjects, abdominal aorta and renal artery involvement, and hypertension. Conclusion Although improvement of symptoms in TA usually follows glucocorticoid therapy, relapses usually occur with dosage reduction. Attempts to restore vascular patency are often initially successful, but restenosis occurs frequently. Chronic morbidity and disability occur in most patients with TA in the US.
Cytoskeletal elements in mycoplasmas and other prokaryotes

This paper reviews the relationship of mycoplasmas to eubacteria, the question of whether mycoplasmas and eubacteria have a cytoskeleton, and whether the unique ultrastructural features of certain mycoplasmas function as a mitotic-like apparatus. Although cytochalasins have inhibitory effects on some mycoplasmas and eubacteria, there are no data indicating that eubacteria have an actin-like protein or other cytoskeletal element. However, the situation for the mycoplasmas remain confusing. While mycoplasma may not contain actin, the data do suggest the presence of other cytoskeletal elements.
The swirling radial free jet

A general similarity solution suggested by Watson for the problem of the laminar, radial, free-jet with swirl has been previously discussed by Riley who also calculated the order to which the solution was valid. That problem is considered in more detail here and higher order terms are given. It is shown that a perturbation scheme for the stream function consisting of a series of inverse powers of ξ and which uses the asymptotic similarity solution as the basic solution is inadequate, and a modification to the series so as to include terms like ξn(ln ζ)m must be adopted in order to satisfy the boundary conditions. It is also shown that the general similarity solution may be obtained from the asymptotic series representing the general case with swirl for certain special values of the free constants and also for the no-swirl or free-jet problem. The asymptotic series is given to order ξ−13 for the case of swirl and to order ζ−29 when there is no swirl.
The Failure of Physiologic Doses of Reverse T3 to Effect Thyroid-Pituitary Function in Man

Reverse T3 (3,3',5'-triiodothyronine, rT3), a major product of the peripheral monodeiodination of thyroxine (T4), was administered to normal male volunteers in doses sufficient to sustain an elevated serum rT3 concentration similar to that frequently observed in patients with nonthyroidal illness. No changes in basal serum T4, T3, TSH and prolactin concentrations, nor in the T3, TSH and prolactin responses to iv TRH were observed during rT3 administration. These findings suggest that physiologic increases in serum rT3 concentration probably do not inhibit T4 to T3 conversion or the anterior pituitary TSH and prolactin responses to thyrotropin-releasing hormone (TRH).
The intracellular signaling pathways involved in MCP-1-stimulated T cell migration across microvascular endothelium.

Abstract The adherence and transmigration of T cells through microvascular endothelium is an essential step for recruitment into inflammatory lesions, although the factors that stimulate the directional migration of T cells have not been fully characterized. In the present study we investigated the capacity of chemokines to induce migration of T cells across dermal microvascular endothelial cell monolayer. The results showed that recombinant MCP-1 significantly induced transendothelial migration of both resting and activated T cells. Maximal induction of migration was observed at a concentration of 10 ng/ml and a 3- to 4-hr incubation period. In contrast, the chemokines IL-8, RANTES, and MIP-1α failed to stimulate T cell migration at doses as high as 100 ng/ml. In studies designed to investigate the intracellular signaling pathways mediating the MCP-1 effect, the results showed that MCP-1 at doses ranging from 10 to 100 ng/ml did not cause an increase in intracellular calcium ions in T cells, even though this chemokine induced rapid calcium mobilization in monocytes. Furthermore, pretreatment of T cells with either bisindolymaleimide HCl, a specific inhibitor of protein kinase C, or genistein, a protein tyrosine kinase inhibitor, significantly decreased the MCP-1-induced transmigration in a dose-dependent manner. In contrast, T cells pretreated with the protein kinase A-specific inhibitor H89 responded normally to MCP-1 stimulation. Finally, T cell transmigration was inhibited by antibodies against CD11a, thereby confirming the importance of β2-integrin in the transmigration process.
Afferent and efferent activity in single units of the cat's optic nerve

Abstract Auditory and somatic stimuli have been shown in a previous study to elicit efferent activity in the optic nerve of cats; this activity was recorded with gross electrodes. This study was undertaken with the purpose of identifying efferent activity at the single unit level. Afferent units and the changes induced in their activity by auditory and somatic stimulation were also analyzed. Twenty healthy, adult cats were used; records were taken from 300 units. Twenty-nine of these units were found to be selectively activated by the nonvisual stimuli and classified as efferent. Among the afferent fibers, forty-eight were modified in their activity by auditory and somatic stimulation. Two types of afferent units with characteristics not previously reported for the cat's retina were indentified during the course of this work. These were units responsive to the light flux, and units responsive to the direction of movement of a spot of light.
Integrating Robot Mapping and Augmented Building Simulation

This paper discusses a framework for integrated augmented reality (AR) architecture for indoor thermal performance data visualization that utilizes a mobile robot to generate environment maps. It consists of three modules: robot mapping, computational fluid dynamics (CFD) simulation, and AR visualization. The robot mapping module enables the modeling of spatial geometry using a mobile robot. In order to generate steady approximations to scanned three-dimensional data sets, the paper presents a novel "split-and-merge expectation-maximization patch fitting" (SMEMPF) planar approximation method. It allows for precise adjustment of patches independent from the initial model. The final result is a set of patches identifying planar macrostructures that consist of a collection of supported tiles. These patches are used to model the spatial geometry under investigation. The CFD simulation module facilitates the prediction of building performance databased on the spatial data generated using the SMEMPF method. The AR visualization module assists in interactive and immersive visualization of CFD simulation results. Such an integrated AR architecture will facilitate rapid multiroom mobile AR visualizations.
Understanding formaldehyde toxicity with the delivered dose concept

Abstract The demonstration that chronic exposure to formaldehyde vapor causes nasal cancer in rats has aroused concern over potential human health effects. It has also sparked a vigorous scientific debate regarding how to make full use of available toxicity data in assessing human cancer risk from exposure to this - and other - chemicals. The relationship between administered and delivered dose has not been elucidated fully for any chemical. However, this relationship cannot be assumed to be linear; the importance of this concept to the determination of risk estimates for various chemicals is self-evident. This review is concerned with research designed to clarify the proportion of an administered dose of formaldehyde that arrives at, or in, target tissues. Some surprising results are described, not least of which is the large interspecies difference observed in the administered: delivered dose ratio. These studies imply that regulatory agency estimates of human risk from chemical exposures (determined only from tumor incidence data v. administered dose) are too simplistic. The possibility that these estimates may actually be inaccurate may give cause for concern, and certainly justifies further research into more accurate assessment of risk.
Depression, smoking, and nicotine : Toward a bioinformational situation by trait model

Associations of psychological depression and negative affect with smoking are well established but need further explanation. Evidence supports the view that neuroticism is an important psychological variable mediating the relationship of genes, depression, and smoking. Both neuroticism and depression are associated with decreased left-frontal and/or increased right-frontal cortical activation and information processing that predispose individuals to negative affect, negative associative processes, withdrawal, and passive coping. In such individuals, nicotine appears to normalize frontal cortical activation asymmetries, and to have antidepressant and anxiolytic effects. Mechanisms that may mediate the antidepressant effects of nicotine and the association of smoking with depression are reviewed and discussed within a bioinformational situation by trait model.
Some thoughts on averaging techniques in stochastic dynamics

Stochastic averaging and quasi-conservative averaging are used essentially to obtain a one-dimensional Markov approximation describing the response of a randomly excited one-degree-of-freedom system. Difficulties arise when the original physical system is more than one degree of freedom with both low and high damping modes, or/and it has a strongly nonlinear stiffness and the stochastic excitation is non-white. The ways in which such difficulties can be overcome are discussed.
Archaeal Clusters of Orthologous Genes (arCOGs): An Update and Application for Analysis of Shared Features between Thermococcales, Methanococcales, and Methanobacteriales

With the continuously accelerating genome sequencing from diverse groups of archaea and bacteria, accurate identification of gene orthology and availability of readily expandable clusters of orthologous genes are essential for the functional annotation of new genomes. We report an update of the collection of archaeal Clusters of Orthologous Genes (arCOGs) to cover, on average, 91% of the protein-coding genes in 168 archaeal genomes. The new arCOGs were constructed using refined algorithms for orthology identification combined with extensive manual curation, including incorporation of the results of several completed and ongoing research projects in archaeal genomics. A new level of classification is introduced, superclusters that untie two or more arCOGs and more completely reflect gene family evolution than individual, disconnected arCOGs. Assessment of the current archaeal genome annotation in public databases indicates that consistent use of arCOGs can significantly improve the annotation quality. In addition to their utility for genome annotation, arCOGs also are a platform for phylogenomic analysis. We explore this aspect of arCOGs by performing a phylogenomic study of the Thermococci that are traditionally viewed as the basal branch of the Euryarchaeota. The results of phylogenomic analysis that involved both comparison of multiple phylogenetic trees and a search for putative derived shared characters by using phyletic patterns extracted from the arCOGs reveal a likely evolutionary relationship between the Thermococci, Methanococci, and Methanobacteria. The arCOGs are expected to be instrumental for a comprehensive phylogenomic study of the archaea.
Protein expression, vascular reactivity and soluble guanylate cyclase activity in mice lacking the endothelial cell nitric oxide synthase: contributions of NOS isoforms to blood pressure and heart rate control

Objective: Both disruption of the endothelial nitric oxide synthase (eNOS) gene and pharmacological inhibition of the NOS produce modest hypertension. It is unclear if and to what extent NOS isoforms other than eNOS contribute to this effect and how loss of one copy of the eNOS gene might impact on vascular reactivity or eNOS protein expression. Methods: We examined protein expression, vascular reactivity, activity of soluble guanylate cyclase, blood pressure and heart rate in mice completely lacking the eNOS gene (eNOS−/−), wild-type mice (eNOS+/+) and mice heterozygotic for the eNOS gene (eNOS+/−). Results: While eNOS−/− mice had mild hypertension and bradycardia, eNOS+/− mice were normotensive. In control mice, oral administration of l-NAME (approximately 100 mg/kg/day×21 days) increased blood pressure to levels observed in eNOS−/− mice. In eNOS−/− mice, chronic oral administration of l-NAME had no effect on blood pressure, suggesting that inhibition of other NOS isoforms unlikely contribute to hypertension. l-NAME treatment induced bradycardia in both control and eNOS−/− mice, suggesting that both eNOS and other isoforms of NOS might be involved in heart rate control. Studies of aortic rings from eNOS−/− mice revealed a complete lack of endothelium-dependent vascular relaxation in response to acetylcholine and the calcium ionophore A23187 and an increase in sensitivity to phenylephrine, serotonin and nitroglycerin. Aortic rings from eNOS+/− mice demonstrated only minor alterations of responses to nitroglycerin and a normal relaxation to either acetylcholine or A23187 compared to vessels from eNOS+/+. Western analysis demonstrated that eNOS expression was virtually identical between eNOS+/+ and eNOS+/− mice and was absent in eNOS−/− mice. The activity of lung-isolated soluble guanylate cyclase was identical in the three strains of mice. Conclusions : We conclude that loss of one copy of the eNOS gene, as observed in heterozygotic animals, has no effect on vascular reactivity, blood pressure or eNOS protein expression. Isoforms of NOS, other than eNOS are unlikely involved in blood pressure regulation but may participate in heart rate control.
Perturbation Theories Using Normal Forms (

Perturbation theories that are based on normal-form techniques are studied within a rigorous Hilbert-space formalism in the context of Schrodinger initial-value problems associated with Hamiltonians having time-independent perturbations to arrive at approximations that deviate in norm from the exact solution by a term of order em + 1t, provided the initial vector is restricted to an appropriate linear submanifold. A new method of approximations is developed and compared with two methods explained recently by Kummer and the present author. It turns out that the operators involved in the new method have simpler construction similar to the second method and the associated error resembles that in the first method. The theory is applied to the one-dimensional quantum-mechanical harmonic oscillator coupled via an interaction of the form e timesAq4, whereq is the position operator, to obtain an explicit construction of a fourth-order approximation.
Stress, behavior and experimental hypertension

Abstract Over the past twenty-five years, several animal models of human essential hypertension have been produced through the development of inbred strains or lines of laboratory rats. The general availability of laboratory rats with genetically determined increases in arterial blood pressure has stimulated an impressive volume of research in the pathophysiology of experimental hypertension. In contrast, relatively little attention has been devoted to the study of behavioral correlates of experimental hypertension. In this review, I will evaluate the advantages and limitations of studying animal models of essential hypertension. Emphasis will then be placed on the relationship between stressful stimulation and behavioral and physiological responsiveness in two animal models of essential hypertension. Specifically, studies from my laboratory have examined sympathetic nervous system activity and behaviors of rats under basal conditions and following acute or chronic exposure to stressful stimulation. These findings indicate that the spontaneously hypertensive (SHR) strain is excessively responsive behaviorally and physiologically to a variety of stressful simuli when compared to its Wistar-Kyoto (WKY) normotensive control strain. In contrast, the behavioral and physiological responses of New Zealand genetically hypertensive (GH) and normotensive (N) rats do not differ following acute exposure to stress. Thus, the hyperreactivity of SHR rats to stressful stimulation is not necessarily related to the development of hypertension but may be a valuable marker of the predisposition to develop high blood pressure in rats of the SHR strain. An experimental approach is outlined for examining the causal relationship between a genetically determined physiological or behavioral marker and the development of hypertension
Psychological issues and treatments for people with diabetes

This article examines psychological issues and their treatment among people with diabetes. The paper contains two main sections, one dealing with diagnosable clinical disorders, and the other with more mundane but nevertheless important subclinical problems in living with diabetes. We review the published literature on prevalence, manifestation, consequences, and treatment of psychological disorders in persons with diabetes, primarily depression, anxiety, and eating disorders. In describing everyday problems in living with diabetes we expand our sources beyond the published literature to include our own clinical and consulting experiences as well as our unpublished qualitative research. These problems include dietary restrictions, self-monitoring of blood glucose, taking insulin injections, and lack of support from family and health care professionals. We describe methods for dealing with such problems and discuss the tension between focusing on emotional distress versus practical issues of disease management. Finally, we briefly present some potentially positive consequences of living with diabetes so that readers can be aware of the inspirational aspects of personal experience with this disease. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 457–478, 2001
IL-22 Production Is Regulated by IL-23 During Listeria monocytogenes Infection but Is Not Required for Bacterial Clearance or Tissue Protection

Listeria monocytogenes (LM) is a gram-positive bacterium that is a common contaminant of processed meats and dairy products. In humans, ingestion of LM can result in intracellular infection of the spleen and liver, which can ultimately lead to septicemia, meningitis, and spontaneous abortion. Interleukin (IL)-23 is a cytokine that regulates innate and adaptive immune responses by inducing the production of IL-17A, IL-17F, and IL-22. We have recently demonstrated that the IL-23/IL-17 axis is required for optimal recruitment of neutrophils to the liver, but not the spleen, during LM infection. Furthermore, these cytokines are required for the clearance of LM during systemic infection. In other infectious models, IL-22 induces the secretion of anti-microbial peptides and protects tissues from damage by preventing apoptosis. However, the role of IL-22 has not been thoroughly investigated during LM infection. In the present study, we show that LM induces the production of IL-22 in vivo. Interestingly, IL-23 is required for the production of IL-22 during primary, but not secondary, LM infection. Our findings suggest that IL-22 is not required for clearance of LM during primary or secondary infection, using both systemic and mucosal models of infection. IL-22 is also not required for the protection of LM infected spleens and livers from organ damage. Collectively, these data indicate that IL-22 produced during LM infection must play a role other than clearance of LM or protection of tissues from pathogen- or immune-mediated damage.
Sports and Performing Arts Medicine: 6. Tendinopathy

Objective This self-directed learning module highlights tendinopathy associated with sports and performing arts. It is part of the study guide on sports and performing arts medicine in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Using a case vignette format, this article specifically focuses on the etiology, pathophysiology, clinical presentation, diagnostic imaging, and management recommendations for tendinopathy. The goal of this article is to allow the learner to better describe the pathophysiology and diagnostic imaging characteristics of tendinopathy, and to formulate an appropriate nonsurgical management algorithm for tendinopathies.
Trends in sonographic fetal organ visualization.

In order to assess changes in sonographic visualization over the last 6 years, 7092 second- and third-trimester ultrasound examinations from separate pregnancies in three individual years (1451 in 1985, 3016 in 1988, and 2625 in 1991) were compared. Overall, visualization across all gestational ages improved from 63.9% (1985) to 85.8% (1988) to 87.3% (1991), with the year in which the scan was performed explaining 19.6% of the variance in visualization. Maternal size (as determined by body mass index) remained the major determinant of ultrasound visualization in 1991 (r² = 11.2%), with gestational age explaining only 5.2% additional variance. Overall organ visualization was maximal at 21–23 weeks' gestation, with the decline in later gestation primarily accounted for by worsened visualization of fetal extremities and spine. Improved fetal visualization earlier in the second trimester and the advent of embryonic visualization in the first trimester may allow a continuum of prenatal sonographic diagnosis. Copyright © 1993 International Society of Ultrasound in Obstetrics and Gynecology
Preschool Outcome of Less Than 801-Gram Preterm Infants Compared With Full-Term Siblings

Objective. Extremely low birth weight (ELBW) infants are at greater risk for neurodevelopmental delay than full-term infants. Outcomes may be compromised secondary to abnormal brain development associated with complications of prematurity. Long-term cognitive outcome has also been reported to be significantly influenced by postnatal factors. The objective of this study was to clarify the effects of prematurity separate from environmental factors on growth and neurodevelopmental outcomes by comparing ELBW children with their full-term siblings. Methods. The study consisted of 25 ELBW children, a subset selected from a larger population of infants who were Results. At follow-up, ELBW children were lighter, were shorter, and had smaller head circumference. The ELBW children had lower Stanford-Binet IQs (85 ± 12 [mean ± SD] and 95 ± 11), with lower Stanford-Binet subtests except short-term memory and quantitative reasoning, lower spelling scores on the Wide Range Achievement Test, and lower Peabody motor quotients (79 ± 11 and 92 ± 17). Preschool Language Scale quotients were not different, but other receptive language measures were lower for ELBW children. High SES seemed to modify the impact of preterm status on cognitive and language but not motor scores. The mean IQ for high-SES ELBW children was equivalent to that of the low-SES term siblings. Conclusions. Preschool-age cognitive and language functioning in ELBW children seemed to be affected by both prenatal and birth influences (preterm status) and postnatal influences (SES variables). Motor scores were significantly related to preterm status but not to SES.
Differentiation and maturation of zebrafish dorsal root and sympathetic ganglion neurons.

The trunk neural crest of vertebrate embryos gives rise to dorsal root ganglion (DRG) sensory neurons and autonomic sympathetic neurons, among other derivatives. We have examined the development of DRG and sympathetic neurons during development in the zebrafish. We found that sensory neurons differentiate rapidly and that their overt neuronal differentiation significantly precedes that of sympathetic neurons in the trunk. Sympathetic neurons in different regions differentiate at different times. The most rostral population, which we call the cervical ganglion, differentiates several days before trunk sympathetic neurons. After undergoing overt neuronal differentiation, sympathetic neurons subsequently express the adrenergic differentiation markers dopamine beta-hydroxylase and tyrosine hydroxylase. A second population of adrenergic nonneuronal cells initially localized with cervical sympathetic neurons appears to represent adrenal chromaffin cells. In more mature fish, these cells were present in clusters within the kidneys. Individual DRG and sympathetic ganglia initially contain few neurons. However, the number of neurons in DRG and sympathetic ganglia increases continuously at least up to 4 weeks of age. Analysis of phosphohistone H3 expression and bromodeoxyuridine incorporation studies suggests that the increases in DRG and sympathetic ganglion neuronal cell number are due wholly or in part to the division of neuronal cells within the ganglia.
Identifiability of path-specific effects

Counterfactual quantities representing path-specific effects arise in cases where we are interested in computing the effect of one variable on another only along certain causal paths in the graph (in other words by excluding a set of edges from consideration). A recent paper [Pearl, 2001] details a method by which such an exclusion can be specified formally by fixing the value of the parent node of each excluded edge. In this paper we derive simple, graphical conditions for experimental identifiability of path-specific effects, namely, conditions under which path-specific effects can be estimated consistently from data obtained from controlled experiments.
Treating Hypertension in the Very Old

Hypertension is prevalent and accounts for a large proportion of cardiovascular morbidity and mortality worldwide.1 There is a continuous, approximately linear, increase in systolic blood pressure ...
Simulating international disarmament negotiations

Although the "era of negotiation" has already begun, we know very little about processes of international negotiation. Discussions about the future of Vietnam are being conducted in Paris, Strategic Arms Limitation Talks are continuing in Vienna and Helsinki, and in Brussels and Luxembourg negotiations to enlarge the European Community have made substantial progress, but scholarly research on negotiation is still in the "pre-theory" stage. Most of the literature on international negotiation is descriptive and anecdotal, consisting of case studies of specific negotiations and negotiators' memoirs.2 While the absence of systematic research on international negotiation may be attributed, in part, to the disinterest and skepticism of social scientists, especially with respect to disarmament negotiations, research has been impeded by the difficulty of gaining access to negotiations that are conducted in private.
Function of various intestinal bacteria in converting germfree mice to the normal state.

Earlier work had shown that a collection of anaerobic bacteria, in conjunction with facultative anaerobes, may be implanted into germfree mice, thereby rendering the animals “normal” with respect to a variety of parameters tested. The present experiments indicate that a different collection of anaerobic bacteria, isolated from the cecum of normal mice, was necessary to convert germfree mice to the “normal” state when the animals were fed a crude diet, rather than the refined food which had been used in the earlier work. The nature and level of short-chain fatty acids associated with various natural or synthetic “normal” floras in the ceca of mice did not always correlate with the Escherichia coli population present, indicating that fatty acids were not the sole agents inhibiting bacterial populations in the intestine. Experiments are reported which indicate that intestinal anaerobes may under certain circumstances be sufficient to control the populations of other intestinal bacteria such as E. coli. In other instances, such as control of Shigella populations in the mouse intestine, intestinal anaerobes appeared to act synergistically with an E. coli strain, in spite of the fact that the population of the latter was itself suppressed by the anaerobes.
Frequency Domain-Based Pseudosliding Mode Flight Control Design

A flight control system design technique previously introduced in the literature is applied to four challenging synthesis problems: (1) design of a hypersonic vehicle autopilot, (2) design of a stability augmentation system for a fighter aircraft, including human-in-the-loop desktop simulator evaluation, (3) design of an autopilot for a cruise missile, and (4) design of a control system for an uninhabited rotorcraft. The vehicle models used in the first and third problems have been employed by other researchers using competing design approaches. Human-in-the-loop desktop simulation of the design in the second problem provides a novel evaluation of the resulting stability and command augmentation system’s ability to accommodate system failures from the standpoint of their effect upon operator dynamics. Finally, the ability of the design procedure to accommodate velocity dependent changes in vehicle dynamics is demonstrated in the rotorcraft example The nine-step synthesis procedure to be exercised is based in the frequency domain and evolves from sliding mode control theory.
Micropixel-Level Image Position Sensing Testbed

The search for Earth-mass planets in the habitable zones of nearby Sun-like stars is an important goal of astrophysics. This search is not feasible with the current slate of astronomical instruments. We propose a new concept for microarcsecond astrometry which uses a simplified instrument and hence promises to be low cost. The concept employs a telescope with only a primary, laser metrology applied to the focal plane array, and new algorithms for measuring image position and displacement on the focal plane. The required level of accuracy in both the metrology and image position sensing is at a few micro-pixels. We have begun a detailed investigation of the feasibility of our approach using simulations and a micro-pixel image position sensing testbed called MCT. So far we have been able to demonstrate that the pixel-to-pixel distances in a focal plane can be measured with a precision of 20 micro-pixels and image-to-image distances with a precision of 30 micro-pixels. We have also shown using simulations that our image position algorithm can achieve accuracy of 4 micro-pixels in the presence of λ/20 wavefront errors.
SHIP: A Scalable Hierarchical Power Control Architecture for Large-Scale Data Centers

In today's data centers, precisely controlling server power consumption is an essential way to avoid system failures caused by power capacity overload or overheating due to increasingly high server density. While various power control strategies have been recently proposed, existing solutions are not scalable to control the power consumption of an entire large-scale data center, because these solutions are designed only for a single server or a rack enclosure. In a modern data center, however, power control needs to be enforced at three levels: rack enclosure, power distribution unit, and the entire data center, due to the physical and contractual power limits at each level. This paper presents SHIP, a highly scalable hierarchical power control architecture for large-scale data centers. SHIP is designed based on well-established control theory for analytical assurance of control accuracy and system stability. Empirical results on a physical testbed show that our control solution can provide precise power control, as well as power differentiations for optimized system performance and desired server priorities. In addition, our extensive simulation results based on a real trace file demonstrate the efficacy of our control solution in large-scale data centers composed of 5,415 servers.
Learning by Reading by Learning to Read

Knowledge-based natural language processing systems learn by reading, i.e., they process texts to extract knowledge. The performance of these systems crucially depends on knowledge about the domain of language itself, such as lexicons and ontologies to ground the semantics of the texts. In this paper we describe the architecture of the GIBRALTAR system, which is based on the OntoSem semantic analyzer, which learns by reading by learning to read. That is, while processing texts GIBRALTAR extracts both knowledge about the topics of the texts and knowledge about language (e.g., new ontological concepts and semantic mappings from previously unknown words to ontological concepts) that enables improved text processing. We present the results of initial experiments with GIBRALTAR and directions for future research.
Approach to the Diagnosis of the Uveitides

Purpose To describe an approach to diagnosing the uveitides, a collection of about 30 separate diseases characterized by intraocular inflammation. Design Perspective. Methods Integration of clinical approach with a more formal, informatics-derived approach to characterization and a Bayesian approach to laboratory testing. Results The patient's uveitis is characterized along several dimensions: course, laterality, anatomic location of the inflammation, morphology, presence of active infection, and the host (age, presence of a systemic disease). Posterior uveitis can be characterized further by whether it is primarily a retinitis, choroiditis, or retinal vasculitis; by whether it is paucifocal or multifocal; and by the morphology of the lesions. This characterization narrows the differential diagnosis to 1 or, at most, a few diseases. Laboratory screening (ie, testing all patients) should be reserved for those diseases that can present as any type of uveitis, whereas targeted testing (ie, testing a subset with specific features) is used selectively. Laboratory testing should be used to identify an infection (which will alter therapy) or a systemic disease that will affect the patient's health. A uveitis that is not one of the established diagnoses is designated as “undifferentiated” with the course, laterality, and anatomic location (eg, undifferentiated bilateral chronic anterior uveitis). We avoid the term “idiopathic” uveitis as most identified noninfectious uveitic diseases are idiopathic, and most systemic diseases associated with uveitis also are idiopathic (eg, juvenile idiopathic arthritis). Conclusion This approach should lead to the correct diagnosis of the specific uveitic disease in the large majority of cases without overuse of laboratory testing.
PATH INTEGRATION AND COGNITIVE MAPPING IN A CONTINUOUS ATTRACTOR NEURAL NETWORK MODEL

A minimal synaptic architecture is proposed for how the brain might perform path integration by computing the next internal representation of self-location from the current representation and from the perceived velocity of motion. In the model, a place-cell assembly called a “chart” contains a two-dimensional attractor set called an “attractor map” that can be used to represent coordinates in any arbitrary environment, once associative binding has occurred between chart locations and sensory inputs. In hippocampus, there are different spatial relations among place fields in different environments and behavioral contexts. Thus, the same units may participate in many charts, and it is shown that the number of uncorrelated charts that can be encoded in the same recurrent network is potentially quite large. According to this theory, the firing of a given place cell is primarily a cooperative effect of the activity of its neighbors on the currently active chart. Therefore, it is not particularly useful to think of place cells as encoding any particular external object or event. Because of its recurrent connections, hippocampal field CA3 is proposed as a possible location for this “multichart” architecture; however, other implementations in anatomy would not invalidate the main concepts. The model is implemented numerically both as a network of integrate-and-fire units and as a “macroscopic” (with respect to the space of states) description of the system, based on a continuous approximation defined by a system of stochastic differential equations. It provides an explanation for a number of hitherto perplexing observations on hippocampal place fields, including doubling, vanishing, reshaping in distorted environments, acquiring directionality in a two-goal shuttling task, rapid formation in a novel environment, and slow rotation after disorientation. The model makes several new predictions about the expected properties of hippocampal place cells and other cells of the proposed network.