cssi/SciSciGPT-SciSciNet huggingface dataset:
Hierarchical Regional Systems and the Politics of System Boundaries

A hierarchical regional system may be defined as a regional international system composed of a single Great Power and a number of relatively small states. This article attempts to clarify the conditions under which member states of a hierarchical regional system, including both the great-power regional hegemon and the relatively small powers, seek to influence the salience that boundaries have for such a system. Scholars and policymakers alike may use several criteria in defining the boundaries of a regional system: 1) A system may be delimited geographically; 2) marked discontinuities in transactional interchanges (language, trade patterns, communication flows) may serve to set it off from the general international system as may common membership in formal international organizations; 3) boundaries may similarly be established by emphasizing behavioral criteria, i.e., by identifying norms especially pertaining to conflict management and resolution which are specific to a group of states. Unless otherwise specified, I employ the last definition throughout this article.
Spectral cascade and phase distribution of coherent structure in an incompressible circular jet

* *~aied Emami and Gerald L. Morrison Mechanical Engineering Department Texas A&M University College Station, Texas 77843 An acoustically excited (St = 0.5), Mach 0.15, free jet operating at a Reynolds number of 41,000 was studied in order to determine the overall turbulence characteristics and to quantify the contributions of the coherent structure. Axial and radial turbulence intensities were measured and were also ensemble averaged. The fluctuation levels maximizing in the shear layer when the potential core was present and on the jet centerline downstream of the potential core. Maximum turbulence levels of 12% and 11% were obtained for the axial and radial turbulence intensities respectively. These levels were based upon the exit velocity of the jet. The coherent structure maximized in amplitude before the end of the potential core and decayed rapidly. The axial fluctuations maximized at 3% of the jet exit velocity on the centerline of the jet while the radial fluctuations maximized at the same level (3%) but in the shear layer of the jet. Spectral cascades of the axial and radial coherent structure fluctuations were performed which illustrate the spatial dependence of the coherent structure's frequency content. Relative phase contours over the entire jet show that at each axial location the phase of the coherent axial flow fluctuation remained comparatively constant in the core region of the jet, but varies rapidly within the shear layers. In contrast, the relative phase distribution for the coherent radial flow fluctuations changed rapidly on the centerline of the jet but remained constant within the shear layers. These relative phase distributions are characteristic of a vortex ring structure.
Sub-Riemannian constant mean curvature surfaces in the Heisenberg group as limits

The 3-dimensional Heisenberg group H together with its standard sub-Riemannian metric g0 is viewed as the limit of a family of Riemannian manifolds, (H,g u ), u>0. For each u>0, we consider some invariant surfaces with constant mean curvature in (H,g u ). These surfaces of (H,g u ) have very nice limits as u→0. We then define the mean curvature of a hypersurface in (H,g0) to be the limit of its mean curvature in (H,g u ). We show that in a more general case, this definition is appropriate.
Low profile wideband embedded dielectric resonator

A dielectric resonator antenna (DRA) made of high dielectric constant substrate is studied. Embedding a higher dielectric disk inside the substrate disk enhances the bandwidth. A narrow slot excites the DRA. Embedded DRAs of different shapes are considered for wideband applications. An eye-shaped DRA made with a circular dielectric resonator disk embedded in an elliptical-shaped ‘host’ DRA is found to have an impedance bandwidth of 28% with stable broadside patterns.
STRUCTURAL AND FUNCTIONAL DIFFERENCES OF PLACENTAL COMPARED TO MYOENDOMETRIAL ARTERIES OF LATE GESTATION RABBITS. † 1193

STRUCTURAL AND FUNCTIONAL DIFFERENCES OF PLACENTAL COMPARED TO MYOENDOMETRIAL ARTERIES OF LATE GESTATION RABBITS. † 1193
Remarks, mostly historical, on signal detection and signal parameter estimation

Historical remarks outlining some of the evolution of the statistical theory of detecting signals in noise and of estimating signal parameters make up the greater part of the paper. The time period covered is roughly from the years of World War II to the middle 1960s. The remarks are rather severely limited in scope; they do not touch on nonparametric statistical methods, or filtering, or prediction theory, for example. The last part of the paper is a discussion of one aspect of a signal-processing problem area that is of current interest in optics and radar, and can be regarded as one of many descendants of the early parameter estimation theory. The area is object-field reconstruction or restoration, and the aspect of interest is the intrinsic relation between the inherent instability of solutions of many such problems and the precision or resolution of detail that can be attained in the construction.
A proportional air-fuel ratio zirconia oxygen sensor

Abstract A novel time-sharing control circuit is used to convert a linear lean exhaust gas oxygen sensor into a proportional extended range (lean or rich exhaust) sensor. The time-sharing oscillator allows a single electrochemical cell to act as both the voltage sensor and as an oxygen pump, thus reducing the complexity of sensor geometry and fabrication compared to the universal exhaust gas oxygen (UEGO) sensor design. The control circuit has been demonstrated in the laboratory using two forms of commercially available ZrO2 cells: (1) a design with a small chamber that opens to the exhaust by a small hole; (2) a design that provides for a limited diffusion region by use of a porous ceramic layer over the outer electrode. The porous-layer design (or a ceramic coating with one or more holes) appears to be a potential candidate for a linear exhaust gas sensor where interest is primarily in a linear response around stoichiometry.
A data adaptive reprojection technique for MR angiography

Inability to detect vessel overlap and vascular loops can compromise the interpretation of magnetic resonance angiograms. A data-adaptive ray tracing (DART) technique was developed to produce the appropriate variations in signal intensity at points of vessel overlap in order to simulate the standard angiographic representation of vessels. In this technique a threshold is utilized to identify vessels in the image slices composing a 3D angiographic data set. A mask, which defines regions slightly larger than the vessel boundaries, is obtained by blurring the vessel information surviving the initial threshold. This mask is converted to binary form prior to multiplication by the original angiographic data set. Following application of an additional threshold to the masked data, line integrals through the regions defined by the mask are performed to obtain an angiographic signal proportional to the integrated vessel signal as in conventional angiography. This integrated reprojection is then uniquely combined with a maximum intensity pixel (MIP) reprojection to produce the final DART image. The application of the DART technique to 2D time-of-flight and 3D phase-contrast angiograms successfully enabled the identification of overlapping vessels and vascular loops. DART was also found to produce less vessel narrowing than the MIP technique. © 1992 Academic Press, Inc.
Fermi transport and Weylian electromagnetism

Abstract This article describes a class of geometric structures on the cotangent bundle of space-time in which the vector potential of the electromagnetic field is related to the dilation 1-form of a semi-metric connection. These geometries satisfy a set of postulates that globalize the postulates of special relativity. When the field strength vanishes the resulting geometric structure realizes Fermi transport as parallel translation relative to a connection on the cotangent bundle
Homologous blood transfusion in dogs with and without heartworm infection.

Abstract Morphine-pentobarbitalized dogs were transfused with homologous whole blood, and both recipient and donor dogs were examined for microfilariae and heartworms. None of the 33 dogs transfused had a fall in blood pressure, and the only detectable reaction to the homologous blood was the development of urticaria in 54% of the recipients. There was no relationship between heartworm infection and the development of urticaria. Also, handling of the blood did not enhance the development of urticaria in the experiment reported here. Further, urticaria developed in a dog receiving a transfusion by an intima-to-intima arteriovenous anastomosis. When the blood from the same donor was transfused into two recipients, one developed urticaria and the other did not, suggesting that urticaria was a result of innate differences between the plasmas of recipient and donor dogs. When a heartworm extract was injected to a group of dogs, most of them had a fall in blood pressure; however, the fall in pressure was not related to the D. immitis infection. Naturally occurring antibodies in the blood of the dog against the water-soluble fraction of a heartworm antigen could not be demonstrated.
Stereoselective Radical Reactions

Radical reactions have several unique features such as high reaction rates, mild/neutral conditions, compatibility with many functional groups, and minimal need for tedious protection/deprotection steps. Radical reactions are well suited for tandem processes and are often the method of choice for synthesizing molecules with complex structures. Even though radical chemistry has been practiced for a long time, only in the past three decades have we seen the emergence of stereoselective radical reactions. This review describes progress in stereoselective radical chemistry, which includes both diastereoselective and enantioselective reactions. Recent developments in radical reactions catalyzed by organocatalysts have shown advantages of high reactivity and ecofriendliness and they are discussed in some detail. Keywords: stereoselective radical reaction; diastereoselective radical reaction; enantioselective radical reaction; substrate-controlled; chiral auxiliary; Lewis acid; organocatalysis
On the properties of optimum realizable linear filters

By means of two simple examples, two commonly held misconceptions about optimum realizable linear filters (Wiener filters) are clarified. It is shown that 1) the magnitude of the transfer function of the Wiener filter for extracting a message from an additive white noise may be greater than unity in a range of frequencies, and 2) the Wiener filter for extracting a message from an additive colored noise may not be of minimum phase.
NGAL distinguishes steroid sensitivity in idiopathic nephrotic syndrome

Background Idiopathic nephrotic syndrome (NS) is the most common glomerular disorder of childhood. Invasive biopsy remains the diagnostic method of choice for NS. Prognosis correlates with steroid responsiveness, from sensitive (SSNS) to resistant (SRNS). Neutrophil gelatinase-associated lipocalin (NGAL) has been demonstrated to be a powerful risk marker of chronic kidney disease progression. We set out to determine if urine NGAL can distinguish between patients with SRNS, SSNS, and healthy controls.
Community reinforcement therapy for cocaine-dependent outpatients.

Objective To examine the contributions of community reinforcement therapy to outcome in the community reinforcement approach (CRA) + vouchers outpatient treatment for cocaine dependence. Methods One hundred cocaine-dependent outpatients were randomly assigned to one of 2 treatment conditions: CRA + vouchers or vouchers only. All patients earned incentives in the form of vouchers exchangeable for retail items contingent on cocaine-free urinalysis results during treatment weeks 1 to 12. Incentives were combined with a 24-week course of CRA therapy designed to promote healthy lifestyle changes in the CRA + vouchers condition, while incentives represented the primary treatment in the vouchers-only condition. Patient drug use and psychosocial functioning were assessed at intake and at least every 3 months for 2 years after treatment entry. Results Patients treated with CRA + vouchers were retained better in treatment, used cocaine at a lower frequency during treatment but not follow-up, and reported a lower frequency of drinking to intoxication during treatment and follow-up compared with patients treated with vouchers only. Patients treated with CRA + vouchers also reported a higher frequency of days of paid employment during treatment and the initial 6 months of follow-up, decreased depressive symptoms during treatment only, and fewer hospitalizations and legal problems during follow-up. Conclusions Combining CRA with vouchers had therapeutic effects on substance abuse and psychosocial functioning during treatment and posttreatment follow-up in cocaine-dependent outpatients, although effects on cocaine use appear to be limited to the treatment period.
Aluminium maltol–induced neurocytoskeletal changes in fetal rabbit midbrain in matrix culture

We have developed a neuronal culture system to evaluate the neurotoxic effects of aluminium maltol on fetal rabbit midbrain sections containing the oculomotor nucleus. Cultures were treated with 5, 7, 9, 11, 13 and 15 mumol/l aluminium maltol or 39 and 45 mumol/l maltol (molal equivalents to 13 and 15 mumol/l aluminium maltol). Control cultures were maintained in nutrient medium alone. Silver-positive neuritic swellings and occasional perikaryal neurofibrillary tangles were observed in cultures treated with 11, 13 and 15 mumol/l aluminium maltol. The number of tangles (involved neurons) produced in aluminium maltol treated cultures were counted and compared to (untreated) controls. We observed a total of 3, 7 and 7% of involved neurons following treatment with 11, 13 and 15 mumol/l aluminium maltol respectively, and none in the control group. By immunohistochemistry, neurofibrillary tangles were immunoreactive with MAbs to phosphorylated (SMI-31), non-phosphorylated, phosphorylation dependent (SMI-32) and phosphorylation independent (SMI-33) epitopes of the high (-H) and middle (-M) molecular weight neurofilament subunits (NF-H/M). By contrast these lesions were nonreactive with MAbs recognizing tau, MAP2 or different beta-tubulin isotypes. The perikaryal tangles consisted of focal accumulations of 10 nm straight filaments by electron microscopy. These findings are in agreement with previous data from rabbit in vivo studies after the administration of aluminium maltol intravenously (Bertholf et al., 1989) or intraventricularly (Katsetos et al., 1990). Using this in vitro system, aluminium-induced neurofibrillary tangles can be consistently produced, and changes in the distribution of neurofilament proteins evaluated. These studies may aid in the assessment of the possible role of aluminium in the aetiology of human neurodegenerative disorders.
A longitudinal study of parenting as a protective factor for children of alcoholics.

Objective: This study examined whether maternal parenting behaviors might serve to protect, or buffer, a child from the potentially negative effects associated with an alcoholic father. Method: This hypothesis was tested with a community sample of adolescent children of alcoholics and a demographically matched comparison group of children with nonalcoholic parents (total N = 278, 55% male). Three dimensions of parenting were considered: monitoring of child behavior, consistency of discipline, and social support. These dimensions were used in both cross-sectional and longitudinal regression analyses to predict child externalizing symptomatology, alcohol use and drug use. Results: Cross-sectional results supported independent effects of parenting on child outcomes, but produced limited support for the buffering hypothesis. Longitudinal analyses revealed no prospective effects of parenting and no support for the buffering hypothesis. Conclusions: Findings suggest that both parents influence child development...
Transfer across perfused human placenta. II. Free fatty acids.

Extract: The rate of transfer of palmitic acid across human placenta was measured in an in vitro perfusion system. The rates of transfer from maternal to fetal circulation and in reverse direction were about the same, and were considerably less than those for antipyrine and leucine. The transfer rate for linoleic acid was similar to that for palmitic acid. An estimate of the absolute rate of transfer for free fatty acids was made which yielded a figure of 6.8 mmol/24 hr. which is less than that required for the deposition of fat by the fetus in the last trimester. These calculations indicate that during the period of rapid accumulation of fat the fetus converts glucose and/or amino acids to that purpose. Uptake and metabolism of palmitate by placental slices differs significantly in the human and the guinea pig. Speculation: It has been suggested that the placental capacity for transfer of some nutrients greatly exceeds requirements, whereas with respect to other nutrients, the capacity for transfer is far more limited. A general reduction in placental function may produce selective nutritional deficiencies in the fetus, beginning with those factors transferred with the smallest margin of safety.
Cross-correlation of three-dimensional images for three-dimensional three-component fluid velocity measurements

A newly conceived technique, termed holographic diffraction image velocimetry, has been investigated computationally and experimentally. The technique can capture 3D three- component velocity fields from a single observation direction. It is based on double-reference- beam double-exposure off axis holography. The independently reconstructed images are then analyzed by applying a cross-correlation technique with transplacing windows. The technique can offer experimental freedom and performance enhancement as compared with conventional techniques in addition to its ability for measuring 3D three-component velocity fields.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Care of the child assisted by technology.

1. Laurie J. Glader, MD* 2. Judith S. Palfrey, MD* 1. *Children's Hospital, Harvard University, Boston, Mass After completing this article, readers should be able to: 1. Describe children who are dependent on technology. 2. List common indications for and complications of gastrostomy tubes. 3. Define invasive and noninvasive mechanical ventilation. 4. Recognize the psychosocial effects of having a child dependent on technology. Over the past 30 years, care for children who have life-threatening conditions has become more sophisticated. As a result, a new population of children who have special health-care needs has evolved: those assisted by medical technology. By definition, such children have a chronic condition that requires daily assistance by a medical device to replace or augment a bodily function to sustain life. (1) Such technologies allow children who previously would have required highly specialized care in a hospital to live at home. Understanding the scope of this population, general concepts, trends, and complications associated with some of the technologies themselves, along with the psychosocial aspects of caring for children assisted by technology at home, is critical for the pediatrician providing a medical home for this growing population of children. Results of a recent national survey indicate that nearly 13% of children in the United States have special health-care needs. (2) These are children who “have or are at risk for chronic physical, developmental, behavioral or emotional conditions and who also require health and related services of a type or amount beyond that required by children generally.” (3) Approximately 50% of these children (6.5% of children nationally) have a disability that impairs their functional daily living. Detailed statistics relating to children dependent on technology are more challenging to obtain; estimates indicate that they comprise 0.16% of the population. (4) The types of technologies on which children who have complex needs rely vary substantially. (5) Among the most common are forms of respiratory support, such as supplemental oxygen or …
Isoproterenol reversal of antiarrhythmic effects in patients with inducible sustained ventricular tachyarrhythmias

Seventeen patients (16 men and 1 woman) were challenged with isoproterenol after their initially inducible sustained ventricular tachyarrhythmia (monomorphic tachycardia in 14 patients and fibrillation in 3) was completely suppressed by class I antiarrhythmic drugs. Coronary artery disease was documented in 11 patients, dilated cardiomyopathy in 2 and no structural heart disease in the remaining 4 patients. The initial presentation was aborted sudden cardiac death (five patients), syncope (eight patients) and symptomatic nonsustained ventricular tachycardia (four patients). The antiarrhythmic drug that rendered the initial ventricular tachyarrhythmias noninducible was class IA in 11 cases, class IC in 5 and combined class IA and IB in 1. The original ventricular tachyarrhythmia became reinducible in 10 patients (group A) and remained noninducible in 7 patients (group B) after isoproterenol infusion at a rate necessary to achieve a 20% increase in heart rate. Despite the results of isoproterenol challenge, all patients were maintained on their electrophysiologically guided antiarrhythmic regimen. During a mean follow-up period of 13 +/- 9 months, 3 of the 10 patients in group A experienced clinical recurrence of tachyarrhythmia; no recurrence was noted in group B. In conclusion, reinducibility of ventricular tachyarrhythmia after beta-adrenergic stimulation seems to identify a subgroup of patients at high risk of subsequent arrhythmic events. Beta-adrenergic blockade or surgical therapy may be indicated in some patients with a positive isoproterenol challenge.
Semiquantitative theory of resonance using Pauling bond orders

Abstract It is shown how the widely used but purely qualitative theory of resonance in organic chemistry can be extended to a semiquantitative form. The extension is accomplished for ground states by relating π electron energies to Pauling bond orders, which are derivable by inspection from Kekule-type resonance structures. For excited states ionic structures must also be considered. The model is applied mainly to hydrocarbon systems in calculations of resonance effects in electrophilic substitution, Diels-Alder reactions, radical stability, ionization potentials, and electronic spectra. Results are expressible in terms of a single parameter which plays a role essentially equivalent to that of β in simple molecular orbital theory. In a series of molecules the semiquantitative ordering of activation energies for attack at various sites, and the variations of radical stability, ionization potential, and spectroscopic red shifts are found to be in substantial agreement with results of molecular orbital calculations. For oxygen acids the approach provides a rough rationalization of Pauling's empirical rule for acid strength. Advantages and weaknesses of the Pauling order scheme are discussed. The principal virtue of the scheme is its extreme simplicity. It can be handled by anyone who can write resonance forms. For this reason there is some hope that it may be developed into a useful tool, even for chemists unschooled in mathematical arts and uninitiated in orbital theory.
Psychosocial Aspects of Pulmonary Hypertension: A Review

Pulmonary arterial hypertension (PAH) is characterized by progressive and sustained elevation of pulmonary-artery pressure, which ultimately leads to right-ventricular failure and death. The diagnosis carries with it an uncertain and historically very bleak prognosis. Although new oral and chronic parenteral (intravenous and subcutaneous) treatments have had a significant positive medical impact on the physical functioning of individuals with PAH, patients often struggle with new short- and long-term psychosocial challenges. The purpose of the current article is to 1) provide a brief review of PAH and its treatment; 2) summarize the limited literature examining the psychosocial adjustment of those with a PAH diagnosis; and 3) provide pertinent information extrapolated from the larger literature on chronic illness that might inform us on the psychosocial challenges faced by the patient diagnosed with PAH.
Correlated Spontaneous Emission Laser as an Entanglement Amplifier

We consider a two-photon correlated emission laser as a source of an entangled radiation with a large number of photons in each mode. The system consists of three-level atomic schemes inside a doubly resonant cavity. We study the dynamics of this system in the presence of cavity losses, concluding that the creation of entangled states with photon numbers up to tens of thousands seems achievable.
Exogenous hormone applications at pollination for in vitro and in vivo production of cotton interspecific hybrids

Interspecific hybridization of cotton (Gossypium) has been assisted by ovule and embryo culture. These culture methods were compared to exogenous hormone applications for efficient plant production from crosses between Upland cotton, G. hirsutum L., as the maternal parent, and various diploid and tetraploid wild species as the pollen donor. The best exogenous hormone treatment resulted in an average production of five seeds per boll and 4% boll abscission. Generally, exogenous hormones used with standard hybridization techniques were superior to in vitro methods, but for some crosses, embryo culture following hormone applications was warranted.
Spin correlations in the two-dimensional S=1 Heisenberg antiferromagnet.

${\mathrm{K}}_{2}$${\mathrm{NiF}}_{4}$ is a well-characterized planar antiferromagnet that represents a good approximation to the idealized two-dimensional (2D) S=1 Heisenberg antiferromagnet. In 1970, Birgeneau, Skalyo, and Shirane measured the 2D antiferromagnetic structure factor in ${\mathrm{K}}_{2}$${\mathrm{NiF}}_{4}$ over a wide range of temperatures. In this report we compare their experimental results with the predictions of a recent theory for the 2D quantum Heisenberg antiferromagnet by Chakravarty, Halperin, and Nelson. The theory describes the temperature dependence of both the absolute value of the correlation length and the relative structure factor peak intensity quantitatively. The crossover temperature to 2D Ising critical behavior is also properly predicted.
Phosphate fertilization reduces zinc adsorption by calcareous soils

Zinc adsorption isotherms were constructed for three calcereous soils which varied in carbonate contents, texture, and past history of phosphate fertilization. The equilibrium conditions were 25°C, 0.01 M CaCl2 and 6 days.
A positron cow.

Abstract Short-lived Ga68 can be prepared from its long-lived parent, Ge68, thus providing a convenient source of positron-emitting activity for medical or other applications. Solvent extraction is used for the rapid separation of the gallium daughter and a method for the production of the germanium parent is given. A review of the usable positron emitters serves to underscore the advantages of the GeGa68 system.
Troubled Memory: Anne Levy, the Holocaust, and David Duke's Louisiana

This powerful work tells the story of Anne Skorecki Levy, the Holocaust survivor who transformed the horrors of her childhood into a passionate mission to defeat the political menace of reputed neo-Nazi and Ku Klux Klan leader David Duke. The first book to connect the prewar and wartime experiences of Jewish survivors to the lives they subsequently made for themselves in the United States, Troubled Memory is also a dramatic testament to how the experiences of survivors as new Americans spurred their willingness to bear witness. Perhaps the only family to survive the liquidation of the Warsaw Ghetto as a group, the Skoreckis evaded deportation to Treblinka, by posing as Aryans and ultimately made their way to New Orleans, where they became part of a vibrant Jewish community. Lawrence Powell traces the family's dramatic odyssey and explores the events that eventually triggered Anne Skorecki Levy's brave decision to honor the suffering of the past by confronting the recurring specter of racist hatred. Breaking decades of silence, she played a direct role in the unmasking and defeat of Duke during his 1991 campaign for the governorship of Louisiana. |How a childhood survivor of the Holocaust found the courage to publicly confront the specter of Neo-Nazism in America. A 2000 Booklist Holocaust Literature Best of the Year Selection. Winner of the 2000 Lillian Smith Book Award, Southern Regional Council
Glutamate-stimulated phosphatidylinositol metabolism in the avian cochlear nucleus.

Abstract This study examined the ability of the excitatory amino acid glutamate and its analogs to stimulate phosphatidylinositol metabolism in isolated cochlear nucleus tissue from young chicks. In the presence of lithium chloride, glutamate and (±)-1-aminocyclopentyl-trans-1,3-dicarboxylate (ACPD) stimulated the formation of inositol phosphates to levels significantly above unstimulated control levels. Unexpectedly, quisqualate did not stimulate inositol phosphates formation. The N- methyl- d -aspartate (NMDA) receptor antagonist 2-amino-5-phosphonovalerate (APV), the ionotropic kainate/quisqualate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and the putative metabotropic glutamate receptor antagonist 2-amino-3-phosphonopropionate (AP3) had no effect on the glutamate stimulated formation of inositol phosphates. We conclude that a metabotropic glutamate receptor is present on cochlear nucleus neurons of posthatch chicks and is able to stimulate formation of inositol phosphates.
NMR studies of pH-induced transport of carboxylic acids across phospholipid vesicle membranes.

Abstract Proton NMR spectroscopy was used to demonstrate that transmembrane pH gradients across single-bilayer vesicle membranes effect the transport and concentration of carboxylic acids. The results obtained indicate that this transport occurs via selective permeation of the membrane by the protonated (uncharged) form of the acid.
Inspiration-induced vasoconstrictive responses in dominant versus non-dominant hands.

Summary Single rapid and deep inspirations (inspiratory gasps, IG) result in arteriolar vasoconstriction with concomitant transient decreases in skin blood flow that are most prominent in fingers and toes. Vascular responses (inspiratory gasp responses, IGR) are determined as the maximum percentage reduction in blood flow and have been used to assess sympathetic neurovascular function in several conditions. Previous studies have described various features of the response but there has been no reported systematic investigation of the degree of similarity between IGR obtained on dominant and non-dominant hands. This aspect is important in procedures that may use IGR to evaluate suspected unilateral sympathetic dysfunction of a limb-pair or to test the effectiveness of physiological interventions imposed on a single limb of a pair. Thus, the goal of our study was to compare IGR magnitudes that were simultaneously determined in paired-fingers of dominant and non-dominant hands. In 30 healthy seated subjects, skin blood perfusion via laser-Doppler (SBF) was measured on the dorsum of the middle finger of both hands while subjects performed three sequential IG at 3-min intervals. Analysis of variance for repeated measures revealed no significant difference in IGR between dominant (79·3 ± 11·2%) and non-dominant hands (81·9 ± 11·6%, P = 0·965) with an overall IGR of 80·6 ± 11·4%. These results indicate that hand-dominance is not a factor that is likely to significantly effect IGR differentials determined in paired-limbs.
Effects of Environmental Temperature on the Concentration of Serum Estradiol, Progesterone, and Calcium in Maturing Female Domestic Fowl

Abstract The effects of environmental temperature on serum estradiol, progesterone, and calcium concentration in White Plymouth Rock pullets were investigated from 12 to 24 weeks of age. Pullets were grown from 10 weeks of age in individual cages at constant environmental temperatures of 13 C, 25 C, or 35 C. Serum estradiol and progesterone concentrations were measured by the use of radioimmunoassay. Serum calcium was measured by an atomic absorption spectrophotometer. There were no significant differences in growth rate or concetration of serum estradiol, progesterone, or calcium between pullets kept at 13 C and 25 C. There was a marked increase in serum estradiol and calcium concentration before onset of lay. There were high correlations between serum estradiol and calcium concentration in pullets kept at 13 C (r = .803) and 25 C (r = .813). Progesterone concentration in pullets kept at 13 C and 25 C reached a peak at 20 weeks of age. By contrast, pullets kept at 35 C had significantly lower growth rates and lower concentrations of serum estradiol, progesterone and calcium than those kept at the other two environmental temperatures. The high environmental temperature of 35 C inhibited growth and delayed sexual maturation of pullets.
Was Market Socialism a Feasible Alternative for Transition Economies

According to the literature and the dominant perception of the International Monetary Fund (IMF), the World Bank, and the economic policymakers within the mature market economies, adoption of the capitalist market economy was the only possible way to avoid stagnation in Central and Eastern Europe and the former Soviet Union (CEEFSU). In reaction to the failures of Stalinism, capitalism came to be seen as the only viable alternative for the people of CEEFSU, even though a capitalist class did not exist in these economies. However, this view is not necessarily accurate. Events might have taken a different course and might have resulted in the adoption of a noncapitalist economic system. Capitalism was not necessarily the mode of production into which these societies were bound to evolve. The collapse of the centrally administered economies cleared the way for development of economies based on market relations. The use of market relations was proposed because of the advantages in the areas of information dissemination and motivation. It was argued that the market was a superior form of organization that would result in a superior outcome compared with central administration, even in the presence of market failure. But even if we take as given that the collapse of centrally administered socialism required the adoption of market relations, as the market socialists argued, did this necessarily imply the adoption of a capitalist system? Because the transition process did not automatically lead to a capitalist economic system, market socialism was worthy of serious consideration.1
Imaging methods that ensure positive images

We discuss methods of image reconstruction which lead to non-negative images: no negative values appear in the estimate or approximation to the unknown object. We describe methods which always lead to non-negative estimates of the object, characterize some regularized and non-regularized methods, and characterize those orthonormal systems whose partial series approximations to the object are always non- negative. This paper surveys the authors' recent research, adds some new results, and discusses related work.
Dyslipidemia is associated with an increased risk of nephrolithiasis

The pathophysiology of nephrolithiasis is multifactorial. Obesity, diabetes mellitus and hypertension are implicated in its formation. Dyslipidemia (DLD) recently has received attention as well. Congruent with a vascular etiology in stone formation, DLD theoretically would predispose patients to nephrolithiasis. We investigated a possible association of DLD with nephrolithiasis. A random cohort of 60,000 patients was established by collecting the first 5,000 patient charts per month in the year 2000. After excluding pediatric patients, a retrospective study was performed by reviewing age, sex, comorbidities, and last patient follow-up. Median lipid laboratory levels also were reviewed. Descriptive statistics were performed as well as Cox proportional-hazards regression analysis, and univariate and multivariate analyses. 52,184 (22,717 women/29,467 men) patient charts were reviewed. The average age was 31.0 ± 15.2 years. On univariate analysis, DLD was associated with nephrolithiasis with a hazard ratio (HR) of 2.2 [Confidence Interval (CI), 1.9–2.5; p < 0.001] and on multivariate analysis HR = 1.2 (1.0–1.5; p = 0.033). Low-density lipoprotein and triglycerides had no association with stone disease. Patients with high-density lipoprotein (HDL) values <45 for men and <60 for women had an HR of 1.4 (1.1–1.7, 95% CI, p = 0.003) on univariate analysis and on multivariate analysis; HR = 1.27 (1.03–1.56; p = 0.024) for nephrolithiasis. DLD was associated with an increased risk of stone disease though the only specific lipid panel associated with lower nephrolithiasis was HDL. Clinicians should consider obtaining lipid levels with the intent that treatment could potentially not only mitigate atherosclerotic disease but also decrease nephrolithiasis risk.
Comparison of the primary structure of class I molecules

Comparison of the primary structure of MHC class I molecules indicates that the structure of the extracellular portion of the molecules is well conserved both within a species and between species. There are 3 extracellular domains of about 90 amino acids with very similar amino acid sequence and conservation of the postion of disulfide loops. Most sites of glycosylation are also conserved. Due to these similarities, frequently the identity of the genetic locus encoding the class I molecule can not be determined from the extracellular sequence of the molecule. The transmembrane and cytoplasmic portions of the class I molecule show great variability between locus and species. However, conservation of sequence for a particular locus or subregion of the MHC such as Qa or TL is quite common, and a particular class I molecule can often be assigned to a locus based on its COOH-terminal sequence. At the present time, no functional significance of the locus-specific COOH-terminal sequences has been determined.
Efficient routing in wireless networks with random node distribution

After deriving the distribution of the distance to the n/sup th/ nearest neighbor in uniformly random networks of any dimension we establish that nearest-neighbor routing schemes perform poorly in random networks. We suggest and analyze an improved scheme that approaches the performance of regular networks.
Election in asynchronous complete networks with intermittent link failures

Considers the problem of fault-tolerant leader election in asynchronous complete (fully-connected) distributed networks. The processors are reliable, but some of the communication channels may fail intermittently before or during the execution of the algorithm. Channel failures are undetectable due to the asynchronous nature of the network. Let n be the number of processors in the network and f be the maximum number of faulty channels incident on each processor, where f/spl les/ 1/2 [n-1]. Our algorithm uses at most O(n/sup 2/+nf/sup 2/) messages to elect a unique leader of the network. Each message consists of at most O(log|T|) bits, where |T| is the cardinality of the set of processor identifiers. All previous algorithms either tolerated only benign failures such as fail-stop failures, assumed that the network is synchronous, tolerated only a small number of failures, or assumed that the faults are detectable. Our algorithm is the first election algorithm that is designed specifically for asynchronous intermittently faulty complete networks in which up to 1/4 n[n-1] channels may be faulty, where each processor is adjacent to no more than 1/2 [n-1] faulty channels, and where the faults are undetectable. >
Hydrophilic bioconjugatable trans-AB-porphyrins and peptide conjugates

Porphyrins bearing a single bioconjugatable group and a single water-solubilization motif in a trans-AB-architecture (with no other substituents) provide a compact design of value for studies in diverse disciplines. Established synthetic methods have been employed to prepare four new free base porphyrins and one Mn(III) chelate. The hydrophilic motif includes 4-N-methylpyridinium, 2,4,6-tris(carboxymethoxy)phenyl, 2,6-bis(phosphonomethoxy)phenyl, and carboxy; the bioconjugatable unit includes carboxy, maleimido, and N-hydroxysuccinimido (NHS) ester. Bioconjugation experiments with a protected porphyrin-diphosphate or unprotected porphyrin-diphosphonate were examined in organic solution or water, respectively. Both approaches were employed to conjugate to the e-amino group of Lys11 in AcKPV-NH2, a tripeptide fragment [Ac-α-MSH(11-13)-NH2] of melanocyte stimulating hormone, yielding porphyrin-peptide conjugates.
Optical preprocessing for increased system throughput

The use of optical preprocessing to increase the rate at which images are processed is examined. For partially coherent illumination, the problem is to design the pupil of the imaging system so that the number of calculations in a postdetection linear filter can be reduced, thereby increasing the rate of processing. The design of the imaging system is a nonlinear apodization problem, which is solved by using parameter-optimization techniques. The results of a numerical example indicate that optical preprocessing can be used to increase processing throughput. The results also indicate that the coherence properties of the illumination strongly influence the effectiveness of the predetection optics: the maximum effectiveness occurs in the case of incoherent illumination.
Direct numerical simulations of bubbly flows. Part 1. Low Reynolds number arrays

Direct numerical simulations of the motion of two- and three-dimensional finite Reynolds number buoyant bubbles in a periodic domain are presented. The full Navier–Stokes equations are solved by a finite difference/front tracking method that allows a fully deformable interface between the bubbles and the ambient fluid and the inclusion of surface tension. The rise Reynolds numbers are around 20–30 for the lowest volume fraction, but decrease as the volume fraction is increased. The rise of a regular array of bubbles, where the relative positions of the bubbles are fixed, is compared with the evolution of a freely evolving array. Generally, the freely evolving array rises slower than the regular one, in contrast to what has been found earlier for low Reynolds number arrays. The structure of the bubble distribution is examined and it is found that while the three-dimensional bubbles show a tendency to line up horizontally, the two-dimensional bubbles are nearly randomly distributed. The effect of the number of bubbles in each period is examined for the two-dimensional system and it is found that although the rise Reynolds number is nearly independent of the number of bubbles, the velocity fluctuations in the liquid (the Reynolds stresses) increase with the size of the system. While some aspects of the fully three-dimensional flows, such as the reduction in the rise velocity, are predicted by results for two-dimensional bubbles, the structure of the bubble distribution is not. The magnitude of the Reynolds stresses is also greatly over-predicted by the two-dimensional results.
Inhibition of acyl-coenzyme A: cholesterol acyl transferase modulates amyloid precursor protein trafficking in the early secretory pathway

Amyloid beta-peptide (Abeta) has a central role in the pathogenesis of Alzheimer's disease (AD). Cellular cholesterol homeostasis regulates endoproteolytic generation of Abeta from the amyloid precursor protein (APP). Previous studies have identified acyl-coenzyme A: cholesterol acyltransferase (ACAT), an enzyme that regulates subcellular cholesterol distribution, as a potential therapeutic target for AD. Inhibition of ACAT activity decreases Abeta generation in cell- and animal-based models of AD through an unknown mechanism. Here we show that ACAT inhibition retains a fraction of APP molecules in the early secretory pathway, limiting the availability of APP for secretase-mediated proteolytic processing. ACAT inhibitors delayed the trafficking of immature APP molecules from the endoplasmic reticulum (ER) as shown by metabolic labeling and live-cell imaging. This resulted in partial ER retention of APP and enhanced ER-associated degradation of APP by the proteasome, without activation of the unfolded protein response pathway. The ratio of mature APP to immature APP was reduced in brains of mice treated with ACAT inhibitors, and strongly correlated with reduced brain APP-C99 and cerebrospinal fluid Abeta levels in individual animals. Our results identify a novel ACAT-dependent mechanism that regulates secretory trafficking of APP, likely contributing to decreased Abeta generation in vivo.
Change/Percent Change From Baseline

Many clinical trials involve baseline and follow-up assessment of a continuous outcome, such as pain, blood pressure, or weight. Different methods are available to analyze the results of such trials, which include between-group two-sample comparisons of the follow-up measure, change score or percentage change, and linear regression of treatment on the follow-up measure with the baseline measure as a covariate [analysis of covariance (ANCOVA)]. Each method provides a statistic that may have greater or less clinical applicability, depending on the particular trial involved. ANCOVA has greatest statistical power irrespective of the correlation between baseline and follow-up measure, the nature of the treatment effect (shift or ratio), whether the control group also experiences change, and the distribution of the follow-up measure. ANCOVA has additional advantages including control for chance baseline differences and incorporation of randomization strata as covariates. If trials results are best expressed in terms other than ANCOVA, such as a percentage change, then the preferred approach is to analyze the trial using ANCOVA and then convert the results into statistics that can be readily understood by clinicians. Keywords: randomized controlled trials; repeated measures; ANCOVA; normal distribution
Elevated testosterone induces apoptosis in neuronal cells.

Abstract Testosterone plays a crucial role in neuronal function, but elevated concentrations can have deleterious effects. Here we show that supraphysiological levels of testosterone (micromolar range) initiate the apoptotic cascade. We used three criteria, annexin V labeling, caspase activity, and DNA fragmentation, to determine that apoptotic pathways were activated by testosterone. Micromolar, but not nanomolar, testosterone concentrations increased the response in all three assays of apoptosis. In addition, testosterone induced different concentration-dependent Ca2+ signaling patterns: at low concentrations of testosterone (100 nm), Ca2+ oscillations were produced, whereas high concentrations (1-10 μm) induced a sustained Ca2+ increase. Elevated testosterone concentrations increase cell death, and this effect was abolished in the presence of either inhibitors of caspases or the inositol 1,4,5-trisphosphate receptor (InsP3R)-mediated Ca2+ release. Knockdown of InsP3R type 1 with specific small interfering RNA also abolished the testosterone-induced cell death and the prolonged Ca2+ signals. In contrast, knockdown of InsP3R type 3 modified neither the apoptotic response nor the Ca2+ signals. These results support our hypothesis that elevated testosterone alters InsP3R type 1-mediated intracellular Ca2+ signaling and that the prolonged Ca2+ signals lead to apoptotic cell death. These effects of testosterone on neurons will have long term effects on brain function.