cssi/SciSciGPT-SciSciNet huggingface dataset:
Biosynthesis of the Branched-Chain Amino Acids in Yeast: a Trifluoroleucine-Resistant Mutant with Altered Regulation of Leucine Uptake

A trifluoroleucine-resistant mutant of yeast has been isolated that exhibits reduced incorporation of the analogue into protein (15%) of that in the wild type. In the mutant, uptake of the analogue and leucine into the expandable (water-extractable) pool is enhanced, passage from the expandable to the conversion (nonwater-, ethanol-extractable) pool is unaffected, and endogenous synthesis of leucine is normally regulated. Although the leucyl transfer ribonucluic acid (tRNA) synthetase appears normal, and the tRNAleu has wild-type acceptor activities in vitro and in vivo, the level of the mutant trifluoroleucyl tRNA pool is only 2 to 3% of that in the wild type. The data support the idea of a mutation affecting passage between the conversion pool and the site of charging of the analogue. The mutation is dominant and exhibits pleiotropic effects: the first leucine biosynthetic enzyme appears nonrepressible, and the leucine, valine, and tyrosine uptake systems are constitutively elevated (three- to fourfold) in the absence of exogenous amino acids.
Decision & risk based design structures; decision support needs for conceptual, concurrent design

In this paper, we elaborate on the decision support needs during conceptual, concurrent design. For this purpose, we consider the type of decision aids that might be helpful to the designers during design, and the information needed by the applications of the products of the design that could be captured and structured by these decision aid tools and processes. We explain our current thoughts and recommendations with respect to the research challenges in this area based on our experience with conceptual, concurrent design teams, as well as our synthesis of the first NASA sponsored workshop on "Decision Based Design Structures" that was held on October 6, 7, & 8/sup th/ 2004 to address some of the same issues. The design context under consideration is space missions.
Infant feeding redux.

Just when it appeared that conflicts about the proper way to feed infants had been resolved, the recent debate about the propriety of some commercial firms advertising on television as well as selling milk formulas directly to mothers in supermarkets has reenergized the issue of infant feeding.1 That infant formulas have reached a state where they may even be considered by some to be safe enough for feeding most infants without the advice of health care professionals demonstrates the huge leap forward in the evolution of infant formula feeding. A short historical review will help us to understand how we have reached our present knowledge of infant feeding practices.
Physics at a $\mu^+\mu^-$ Collider

A brief overview of the physics capabilities of a $\mu^+\mu^-$ collider is given, with particular focus on special Higgs sector opportunities.
A familial neuronal disease presenting as intestinal pseudoobstruction

The purpose of this paper is to describe 2 siblings who had a generalized neurological disease which presented as intestinal pseudoobstruction. The siblings had 40-year histories of abdominal pain, distention, and vomiting as well as gait ataxia, small, irregular, poorly reactive pupils, dysarthria, absent deep tendon reflexes, and impaired vibratory and position senses. Compared with age-matched controls, they had inappropriate blood pressure responses to phenylephrine, the Valsalva maneuver, and upright posture, lack of sweating on warming, and pupillary denervation hypersensitivity. Radiographs revealed hyperactive, nonpropulsive contractions of a dilated esophagus and small intestine and extensive colonic diverticulosis. Esophageal manometry recorded repetitive, spontaneous, nonperistaltic waves and positive Mechyolyl tests. Postmortem examinations showed degeneration of the myenteric plexuses of the esophagus, small intestine, and colon of both patients. Myenteric plexus neurons were significantly reduced in number compared with 7 controls. About one-third of the siblings' neurons contained round, eosinophilic intranuclear inclusions, which, by histochemistry, were composed of protein by lacked RNA, DNA, carbohydrate, and fat. By electron microscopy the inclusions consisted of an irregular array of nonviral, nonmembrane-bounded filaments. Neurons and glial cells of the brain, spinal cord, dorsal root, and celiac plexus ganglia contained identical intranuclear inclusions. Intestinal smooth muscle was normal. These 2 siblings represent a unique disease in which degeneration of the myenteric plexus resulted in hyperactive but uncoordinated smooth muscle activity and the clinical syndrome of intestinal pseudoobstruction, the presenting manifestation of their neurological disease.
Direct observation of vinyl hydroperoxide

Many alkyl-substituted Criegee intermediates are predicted to undergo an intramolecular 1,4-hydrogen transfer to form isomeric vinyl hydroperoxide species (CCOOH moiety), which break apart to release OH and vinoxy radicals. We report direct detection of stabilized vinyl hydroperoxides formed via carboxylic acid-catalyzed tautomerization of Criegee intermediates. A doubly hydrogen-bonded interaction between the Criegee intermediate and carboxylic acid facilitates efficient hydrogen transfer through a double hydrogen shift. Deuteration of formic or acetic acid permits migration of a D atom to yield partially deuterated vinyl hydroperoxides, which are distinguished from the CH3CHOO, (CH3)2COO, and CH3CH2CHOO Criegee intermediates by mass. Using 10.5 eV photoionization, three prototypical vinyl hydroperoxides, CH2CHOOD, CH2C(CH3)OOD, and CH3CHCHOOD, are detected directly. Complementary electronic structure calculations reveal several reaction pathways, including the barrierless acid-catalyzed tautomerization reaction predicted previously and a barrierless addition reaction that yields hydroperoxy alkyl formate.
Annealing effects on surface morphology of Si(100)

The temperature and time dependencies of Si(100) surface morphology have been investigated using in situ Auger Electron Spectroscopy and ex situ Atomic Force Microscopy. Surface carbon and oxygen concentrations are lowered below the detection limits of AES at /spl sim/900/spl deg/C while a roughening process starts before this temperature. The proportional relationship of Si(100) surface roughness to annealing temperature and time reflects that the annealing process is dominated by silicon surface evaporation. The abrupt decrease of surface roughness at above 1100/spl deg/C is attributed to the dissolution of SiC into the bulk.
Piecewise linear test functions for stability of queueing networks

Presents an algorithm that allows the computer automation of the analysis of the stability of re-entrant lines. Through various examples, it is suggested that this method may completely characterise the region of stability for the types of networks considered. For the class of non-idling and buffer priority policies, piecewise linear functions of low complexity are constructed. To construct such functions for other policies such as FIFO appears to be more difficult in general, due to the complex state representation of such models. >
Genomic analysis of metastasis reveals an essential role for RhoC

The most damaging change during cancer progression is the switch from a locally growing tumour to a metastatic killer. This switch is believed to involve numerous alterations that allow tumour cells to complete the complex series of events needed for metastasis. Relatively few genes have been implicated in these events. Here we use an in vivo selection scheme to select highly metastatic melanoma cells. By analysing these cells on DNA arrays, we define a pattern of gene expression that correlates with progression to a metastatic phenotype. In particular, we show enhanced expression of several genes involved in extracellular matrix assembly and of a second set of genes that regulate, either directly or indirectly, the actin-based cytoskeleton. One of these, the small GTPase RhoC, enhances metastasis when overexpressed, whereas a dominant-negative Rho inhibits metastasis. Analysis of the phenotype of cells expressing dominant-negative Rho or RhoC indicates that RhoC is important in tumour cell invasion. The genomic approach allows us to identify families of genes involved in a process, not just single genes, and can indicate which molecular and cellular events might be important in complex biological processes such as metastasis.
Perceived medication assignment during a placebo-controlled laboratory study of varenicline: temporal associations of treatment expectancies with smoking-related outcomes.

Expectancies regarding treatment assignment may influence outcomes in placebo-controlled trials above and beyond actual treatment assignment. For smoking pharmacotherapies, guessing enrollment in the active medication treatment is associated with higher abstinence rates. However, placebo-controlled trials of smoking pharmacotherapies rarely assess perceived treatment assignment and those that do only collect this information after reaching full dosage. To determine the temporal relationship between treatment expectancies and smoking-related variables, we assessed the impact of treatment guess during a placebo-controlled laboratory study of varenicline on measures of craving, smoking reward, and smoking reinforcement. We hypothesized that treatment guess at mid-titration would influence smoking-related measures at full dosage, above and beyond actual medication effects. We also explored factors related to guess stability and differences in blind fidelity between mid-drug titration and full dosage. Eighty-eight participants completed laboratory assessments at baseline, mid-titration, and full dosage that involved self-report and behavioral measures of tonic craving, cue-provoked craving, smoking reward, and smoking reinforcement. Participants guessed treatment assignment at mid-titration and full dosage. Generalized linear models confirmed that, beyond actual treatment assignment, treatment guess improved model fit for both self-report and behavioral smoking-related measures. Further, accuracy of treatment guess improved from titration to full dosage, and specific demographic factors (e.g., gender, race) were associated with type of treatment guess and guess stability across time. These results reinforce the importance of assessing perceived treatment assignment repeatedly during placebo-controlled trials and suggest that treatment expectancies during titration can affect outcomes once full dosage has been reached.
Inverse Problem in Ground Water: Model Development

A model to solve the inverse problem in ground water has been developed. The model consists of an unconstrained multivariable optimization algorithm and a ground-water simulation model. The optimization algorithm is a modified version of Newton's second derivative method. It is a ground-water-specific algorithm and was found to be more efficient than other more general unconstrained optimization algorithms requiring first- and/or second-order derivatives and those requiring no derivatives. The groundwater simulation model is based on a finite-difference technique but it can be replaced easily by a finite-element model. The results of an application of this model to a real aquifer are discussed in a companion paper titled “Inverse Problem in Ground Water: Model Application.”
American Indian heritage and risk factors for renal injury

American Indian heritage and risk factors for renal injury. Background Little is known about the causes and consequences of renal disease among American Indians in the Great Lakes region of the United States. Methods We examined clinical correlates of albumin/creatinine ratios among 1368 participants in the three tribal communities of the Inter-Tribal Heart Project using univariate and multivariate analysis. Results Compared to 1086 participants without albuminuria, the 240 with microalbuminuria (30 to 299mg/g) and the 42 with macroalbuminuria (>300mg/g) were more likely to report a history of a myocardial infarction (6.4%, 16.0%, and 23.8%, respectively, P P P Conclusions Urinary albumin excretion is associated with cardiovascular disease outcomes and risk factors among American Indians of the Great Lakes region. Both heredity and socioeconomic status appear to play a role in the pathogenesis of renal injury in this population.
Animal models for HIV/AIDS research

The AIDS pandemic continues to present us with unique scientific and public health challenges. Although the development of effective antiretroviral therapy has been a major triumph, the emergence of drug resistance requires active management of treatment regimens and the continued development of new antiretroviral drugs. Moreover, despite nearly 30 years of intensive investigation, we still lack the basic scientific knowledge necessary to produce a safe and effective vaccine against HIV-1. Animal models offer obvious advantages in the study of HIV/AIDS, allowing for a more invasive investigation of the disease and for preclinical testing of drugs and vaccines. Advances in humanized mouse models, non-human primate immunogenetics and recombinant challenge viruses have greatly increased the number and sophistication of available mouse and simian models. Understanding the advantages and limitations of each of these models is essential for the design of animal studies to guide the development of vaccines and antiretroviral therapies for the prevention and treatment of HIV-1 infection.
Isolation and characterization of products from the nitrosation of the alkaloid gramine

The nitrosation of gramine, a tertiary amine alkaloid present in barley malt, was carried out by reaction with sodium nitrite in buffered acetic acid (pH 3.4) for 1 hr at room temperature. Two major non-volatile products of the nitrosation reaction were isolated by preparative HPLC and characterized as indole-3-carboxylic acid and N1-nitroso-3-nitromethylindole. This interpretation was supported by spectral data. The nature of these products indicated that gramine did not undergo nitrosation by the expected mechanism of nitrosative dealkylation. A mechanism is offered to explain the labile nature of the dimethylamino group found in gramine.
The M-Health Reference Model: An Organizing Framework for Conceptualizing Mobile Health Systems

The reference model presented in this article encourages the breakdown of M-Health systems into the following five key dimensions: (1) Communication Infrastructure: a description of mobile telecommunication technologies and networks; (2) Device Type: the type of device being used, such as PDA, sensor, or tablet PC; (3) Data Display: describes how the data will be displayed to the user and transmitted, such as images, e-mail, and textual data; (4) Application Purpose: identification of the objective for the M-Health system; (5) Application Domain: definition of the area in which the system will be implemented. Healthcare stakeholders and system implementer can use the reference model presented in this article to understand the security implications of the proposed system and to identify the technological infrastructure, business requirements, and operational needs of the M-Health systems being implemented. A reference model that encapsulates the emerging M-Health field is needed for cumulative progress in this field. Currently, the M-Health field is disjointed, and it is often unclear what constitutes an M-Health system. In the future, M-Health applications will take advantage of technological advances such as device miniaturizations, device convergence, high-speed mobile networks, and improved medical sensors. This will lead to the increased diffusion of clinical M-Health systems, which will require better understanding of the components that constitute the M-Health system.
Effects of ascorbic acid on proliferation and collagen synthesis in relation to the donor age of human dermal fibroblasts

Several events are associated with cellular aging: alterations in the extracellular matrix, loss of the cell's proliferative capacity, and decreased responsiveness to growth factors. In skin, a major component of the extracellular matrix is collagen; an important regulator of collagen synthesis is ascorbic acid, which may also have growth factor-like properties. To investigate the relationship of the extracellular matrix and proliferative capacity to aging, we examined the effects of ascorbic acid on cell proliferation and collagen expression in dermal fibroblasts from donors of two age classes, newborn (3-8 d old) and elderly (78-93 years old). In the absence of ascorbic acid (control) proliferative capacities were inversely related to age; newborn cell lines proliferated faster and reached greater densities than elderly cell lines. However, in the presence of ascorbic acid both newborn and elderly cells proliferated at a faster rate and reached higher densities than controls. To determine whether there are age-related differences in extracellular matrix production and ascorbic acid responsiveness we examined and found that collagen biosynthesis (collagenase-digestible protein) was inversely related to age, but the stimulation by ascorbic acid appeared age independent. The increase in collagen synthesis was reflected by coordinate increases in steady-state pro alpha 1(I) and pro alpha 1(III) collagen mRNAs, suggesting a pretranslational mechanism. Ascorbic acid appears capable of overcoming the reduced proliferative capacity of elderly dermal fibroblasts, as well as increasing collagen synthesis in elderly cells by similar degrees as in newborn cells even though basal levels of collagen synthesis are age dependent.
Cyclic AMP (cAMP) signaling in melanocytes and melanoma

G-protein coupled receptors (GPCRs), which include melanocortin-1 receptor (MC1R), play a crucial role in melanocytes development, proliferation and differentiation. Activation of the MC1R by the α-melanocyte stimulating hormone (α-MSH) leads to the activation of the cAMP signaling pathway that is mainly associated with differentiation and pigment production. Some MC1R polymorphisms produce cAMP signaling impairment and pigmentary phenotypes such as the red head color and fair skin phenotype (RHC) that is usually associated with higher risk for melanoma development. Despite its importance in melanocyte biology, the role of cAMP signaling cutaneous melanoma is not well understood. Melanoma is primarily driven by mutations in the components of mitogen-activated protein kinases (MAPK) pathway. Increasing evidence, however, now suggests that cAMP signaling also plays an important role in melanoma even though genetic alterations in components of this pathway are note commonly found in melanoma. Here we review these new roles for cAMP in melanoma including its contribution to the notorious treatment resistance of melanoma.
Net Absorption of Glucose and Nitrogenous Compounds by Lactating Holstein Cows

Abstract Net absorptions from portal-drained viscera of glucose, ammonia nitrogen, α -amino nitrogen, and urea nitrogen were measured in four Holstein cows in first lactations. Cows were fed for ad libitum consumption a completely mixed, 60:40 corn silage:supplement diet (dry basis) in two equal feedings at 12-h intervals daily. Portal blood flow (dye dilution) and net absorption (portal-arterial difference times portal blood flow) were measured at hourly intervals for 12h for all cows 4 and 8 wk postpartum and for two cows 4, 8, 12, 16, and 20 wk postpartum. Apparent digestibilities of dry matter and nitrogen were measured immediately after net absorption. Milk yield and composition were measured with absorption and digestion. Mean daily dry matter intake and milk yield were 14.1±.6 and 23.8±1.8kg. Portal blood flow was not affected by time of day or weeks postpartum; mean was 1371±123 liters/h. Net absorption of glucose was negative, indicating no uptake of glucose from dietary sources. Means (g/day) for nitrogenous sources were: nitrogen intake 387, fecal nitrogen 121, urinary nitrogen 146, milk nitrogen 116, net ammonia nitrogen absorption 149, net α -amino nitrogen absorption 137, and net loss of urea nitrogen from blood to the gut 93. Net absorption of amino nitrogen and α -amino nitrogen in blood was greater than in plasma; corresponding losses of urea nitrogen and glucose to the gut were greater from blood than plasma.
Co-Offender Ties and the Criminal Career The Relationship between Co-Offender Group Structure and the Individual Offender

Objectives:This study aims to assess three related aspects of co-offending networks: (1) the characteristics of co-offending groups and the duration of group offending careers, (2) the impact of membership in co-offending groups on total offending and the length of individual offending careers, and (3) the impact of offender arrest (or changes in co-offending group structure) on the offending patterns of connected co-offenders.Methods:Data on sentenced burglary offenders (N = 270) in one county in Pennsylvania from 2001 to 2010 are used to examine the impact of co-offending group membership, as well as the relationship between the changing network structure and the offending patterns of connected co-offenders, within a two-level modeling framework.Results:Larger groups with more dispersed offending structures offend over the longest span. Additionally, membership in co-offending groups is associated with more total offending and a longer individual offending career. Finally, the arrest of structurally imp...
Assessing vulnerability to earthquake hazards through spatial multicriteria analysis of urban areas

Assessing urban vulnerability to natural hazards such as earthquakes can be regarded as an ill-structured problem (i.e. a problem for which there is no unique, identifiable, objectively optimal solution). A review of the literature indicates a number of contrasting definitions of what vulnerability means, as well as numerous conflicting perspectives on what should or should not be included within the broad assessment of vulnerability in cities. This paper reports on the findings from a project in which a GIS methodology has been developed to assess urban vulnerability through a spatial analytical procedure. First, we highlight the deficiencies of current GIS approaches to urban vulnerability analysis and discuss the ill-structured nature of the vulnerability problem. We then propose a working definition for vulnerability assessment in which vulnerability is thought of as a spatial decision problem under the conditions of uncertainty. Next, we present a methodology to incorporate this definition into a GIS...
Ignitor Plug Operation in a Pulsed Plasma Thruster

Results are presented of a 1-mlb pulsed plasma thruster ignition system study. An ignitor plug, producing a plasma stream is used to ignite this type of electric thruster. Parameters investigated during these tests were ignitor plug deposition, erosion, optimum plug electrical coupling to the thruster cathode, and the manner in which the ignitor plug arc is initiated. The results of these tests indicate that inductive rather than resistive coupling of the ignitor plug to the thruster cathode and the use of a high-current, short-pulse-length plug trigger circuit offer significant increases in ignitor plug lifetime.
The Angular Distribution of the Photo-Neutrons from Beryllium

The angular distribution of the photo-neutrons from beryllium has been studied for $\ensuremath{\gamma}$-ray energies of 1.70, 1.81, and 2.76 Mev. The distribution was found to be spherically symmetrical for the 1.70- and 1.81-Mev $\ensuremath{\gamma}$-rays. The 2.76-Mev gamma-ray yields a distribution of the form $a+b{sin}^{2}\ensuremath{\theta}$ with $\frac{a}{b}=1.2$.
Vasomotor reaction of retinal arterioles in hypoxic and ischemic conditions

Purpose Retinal blood flow is autoregulated by the adaptation of the vascular tone of resistance vessels (arterioles, capillaries) to changes in the perfusion pressure (PP) or metabolic needs of the tissue. The purpose of this study was to evaluate the disturbance of arteriolar reactivity, and thus of blood flow regulation, during the evolution of ischemic retinal microangiopathies. Methods Much of our basic knowledge of retinal arteriolar reactivity is based on data obtained from animal experiments through the use of invasive techniques. However, a variety of non-invasive techniques has been applied to the human eye for the investigation of retinal hemo-dynamics and, more specifically, the reactivity of the retinal arterioles in response to a number of physiologic and pharmacologic stimuli, under normal, hypoxic and ischemic conditions. Results In patients with non-proliferative diabetic retinopathy (DR), isocapnic hypoxia induces a significant increase in Vleuk in the perifoveal circulation, whereas in patients with proliferative DR, the diameter of the retinal vessels remains unchanged, indicating that blood flow regulation in response to a hypoxic challenge is blunted,consequent to the hypoxic retinal conditions. In those patients a hyperoxia-induced blunted vasoconstriction of the retinal arterioles is also observed. The ability of the retinal arterioles to respond to changes in ocular PP is altered in diabetes, while the response of retinal vessels to diffuse luminance flicker is blunted, particularly in patients suffering from insulin-dependent diabetes. Conclusion During the evolution of retinal ischemic microangiopathies, impairment of various mechanisms of retinal arteriolar reactivity leads to disturbed retinal blood flow regulation.
Rational Revolution: Extensions of the "By-Product" Model of Revolutionary Involvement

NDIVIDUALS often join revolutions for reasons that are personal, material, and immediate. To explain this, political economists have proffered the "by-product theory of revolutionary participation"-that is, revolutionary involvement is often a by-product of participation in a movement that performs other, personal functions for the individual (Tullock, 1971; Silver, 1974; Ireland, 1976). Gordon Tullock, for example, has argued that
From the historian-designing the United States' initial 'deep-space networks': choices for the Pioneer lunar-probe attempts of 1958-9

To support the series of early Pioneer lunar-probe attempts by the US Air Force and US Army, Ramo-Wooldridge's Space Technology Laboratories (STL) and Caltech's Jet Propulsion Laboratory (JPL) designed two separate networks of ground stations in 1958-9. Since the probes were means of restoring international prestige to the US, and thus were scheduled to be launched within a year of authorization, both networks had to be installed on a crash basis. The differences between the two initial networks in terms of antenna design, operating frequency, and location are described, and it is shown how the extra months afforded to JPL due to the later launches of the Army probes allowed its engineers to design and install the first elements of a system that evolved within a few years into NASA's Deep Space Network. >
A generalized front marching algorithm for the solution of the eikonal equation

A new front marching algorithm for solving the eikonal equation is presented. An important property of the algorithm is that it can be used on nodes that are located on highly distorted grids or on nodes that are randomly located. When the nodes are located on an orthogonal grid, the method is first-order accurate and is shown to be a generalization of the front marching algorithm in (Proc. Natl. Acad. Sci. 93 (4) (1996) 1591). The accuracy of the method is also shown to be dependent on the principle curvature of the wave front solution. Numerical results on a variety of node configurations as well as on shadow, nonconvex and nondifferentiable solutions are presented.
Predicting the Effectiveness of Phragmites Control Measures using a Rhizome Growth Potential Bioassay

In the last century, Phragmites australis (common reed) has expanded from a minor component of the mid-Atlantic tidal wetlands to a dominant species in many locations. Expansion of Phragmites results in decreased plant diversity and alterations to the tidal characteristics of the marsh, resulting in decreased wetland value. Management efforts have used a variety of strategies in an attempt to control its expansion. We tested a greenhouse bioassay that provided insight into the rhizome vitality of six herbicide-treated sites in the Alloway Creek Watershed, NJ well in advance of the growing season. At three sites, rhizomes were exhumed and classified by depth (0–25 cm and 25–75 cm) and appearance (color and firmness). Concurrently, the same protocol was followed, but conducted on an areal basis at three additional sites. Material was grown in sand under greenhouse conditions void of nutrient supplements for 70 days, after which shoots were removed and the rhizomes replanted for 30 days. Effectiveness of control strategies was quantified by examining rhizome color, vitality, and shoot densities in the field. Color was indicative of quality of rhizome reserves. Less than 0.2% of the firm, brown rhizomes produced shoots upon initial planting and none produced shoots upon replanting, whereas 50.9% of white rhizomes produced shoots on initial planting. Rhizome vitality was quantified by examining shoot emergence and the morphology of the shoots. Coupling rhizome vitality with observed field densities resulted in a predictive capability, and shoot density and biomass predictions were compared to field measurements in July 2001. We tested and accurately predicted the relative shoot densities and shoot biomass of the three sites for which we collected rhizome material on an areal basis. The result is a rapid, valuable, and cost-effective monitoring tool that can quickly quantify the effects of past control methods and predict future growth potential.
Limiting mechanism on rapid charging NiMH batteries

Abstract Nickel metal hydride (NiMH) battery systems are emerging as a competitive technology in the power electronics and tool market and for electric and hybrid vehicle applications. The ability to rapid charging the NiMH batteries can greatly enhance their market acceptance and penetration. We have demonstrated the possibility of rapid charging a commercial NiMH traction battery system at high rates. This paper will discuss the mechanism that limits the rapid charging capability of the system. We will further discuss how to control the charging process.
Spontaneous withdrawal in opiate-dependent Fischer 344, Lewis and Sprague–Dawley rats

Abstract The Lewis (LEW) and Fischer 344 (F344) inbred rat strains react differentially to acute morphine administration for a variety of behavioral and neurochemical measures. Investigations into effects of chronic morphine are less common, and investigations assessing dependence have been limited to those utilizing antagonist-precipitated withdrawal. The present experiment extended these assessments by examining spontaneous withdrawal in the LEW and F344 strains. In this preparation, males of the LEW, F344 and the outbred Sprague–Dawley (SD) strain were made dependent on morphine. Following this, opiate administration was terminated and animals were examined for spontaneous withdrawal by the acquisition of a withdrawal-associated taste aversion, changes in body weight loss and the display of several behaviors characteristic of opiate withdrawal. Although all morphine-treated subjects decreased body weight and avoided consumption of the withdrawal-associated solution, indicating successful induction of dependence, no difference between the strains emerged in these indices of withdrawal severity. The only strain difference to appear in the behavioral indicators of withdrawal was with diarrhea (LEW > F344). That the strains differ in acute reactivity to opioids, but not in the overall severity of withdrawal, was discussed in relation to the need to examine the relationship between neurochemical and behavioral data in a variety of neural systems and behavioral endpoints.
Effect of tryptophan on toxicity and depressant effects of barbiturates and ethanol in rats

When the fasting plasma amino acid profile of Sprague-Dawley rats was determined chromatographically, it was found that, of the essential amino acids, 1-tryptophan and 1-methionine were present in the lowest concentration. Using 1-tryptophan because of its reported antidepressant effects, it was found that pretreatment of rats with this amino acid decreased the LD50 and prolonged the sleeping times and immobility times previously determined for pentobarbital, hexobarbital, and ethanol. It is concluded that acute administration of 1-tryptophan will not reverse the toxicity of these CNS depressants.
A Model of Moral Courage: A Study of Leadership for Human Rights and Democracy in Myanmar

AbstractThis article presents a conceptual model of moral courage based on results of an exploratory, qualitative, and cross-cultural study of the moral courage of leaders of grass roots organizations working for human rights and democracy in Myanmar. Interviews were conducted in Myanmar and Thailand with 19 participants who as leaders of primarily small, local, and non-governmental organizations regularly engaged in acts of moral courage. Consistent with a definition of moral courage based on a review of the literature on moral courage, an analysis of the interview data reveals a relationship between moral motivation and the demonstration of moral courage that is mediated by political, social, and psychological factors, as well as by activist knowledge. Demonstrations of moral courage result in both positive and negative outcomes for individuals, organizations, and society. Understanding how key elements of moral courage might lead to political and social change provides leaders of civil society organiza...
Effects of hypophysectomy and corticosterone acetate treatment on hepatic lipid composition in the chick (Gallus domesticus) embryo

days of incubation in the intact chicken embryo. Hypophysectomy (partial decapitation) at 36 hr of incubation reduced liver lipid content on Days 16 and 18. The greatest losses on Day 18 were among cholesterol esters but decreased unesterified cholesterol and phospholipid were also observed. Treatment of hypaph-ysectomized embryos with corticosterone acetate (300 pg per day on Days 13, 14, 15) partially restored total hepatic lipid content to control values on Day 16, with an even greater effect on 18 days of incubation. Most of the increase in lipid occurred in the triglyceride fraction. Liver cholesterol content also increased in response to hormone but neither cholesterol esters nor phospholipids were elevated by corticosterone acetate. Hypophysectomy interferes with the absorption of lipids from yolk and with fat deposition in embryonic liver. However, treatment of hypophysectomized embryos with corticosterone acetate did not correct the major defects in hepatic lipid content. Therefore, fat metabolism and transport of yolk lipids to the embryo during the last week of incubation does not depend exclusively on adrenal glucocorticoids. Lipid metabolism in the avian embryo differs markedly from that observed in birds after hatching. This difference stems from the large amount of lipid stored in the yolk. Some yolk lipid components can be readily utilized by the embryo with only modest transformations in fatty acid composition (Noble and Moore, 1964). Lipogenesis, therefore, can be low in embryonic liver without loss of substrate required for lipid metabolism or for biosynthesis of celIular membranes (Goodridge, 1968a,b; Donaldson
Nonresonant ( Δ m = 0 ) Ultrasonic Coupling to Spin Quadrupole Modes in a Dilute Paramagnetic System

We report the first use of low-frequency, nonresonant ($\ensuremath{\Delta}m=0$) ultrasound to investigate the dominant spin-lattice relaxation processes in dilute paramagnetic systems. A theory of the interaction of paramagnetic spins with ultrasonic waves is presented which emphasizes the coupling of acoustic waves to $〈{{S}_{z}}^{2}\ensuremath{-}\frac{1}{3}S(S+1)〉$, the $l=2$, $m=0$ spin quadrupole. Results of experiments over the range 4.2 to 30 K, using 30-MHz longitudinal ultrasonic waves in single-crystal MgO: ${\mathrm{Fe}}^{2+}$, are consistent with theoretical predictions.
Explicit Finite Element Simulation of Granular Flow in an Annular Shear Cell

Explicit finite element method modeling of granular flow behavior in an annular shear cell has been studied and presented in this paper. The explicit finite element method (FEM) simulations of granular flow in an annular shear cell with around 1633 particles were performed, where the inner wheel rotated at a very high speed and the outer disk remained stationary. The material properties of the particles and the outer wheel were defined as elastic steel whereas the inner wheel was elastic aluminum. In this investigation, the explicit FEM model mimicked granular flow in an experimental set up where the inner wheel was rotated at a speed of 240 rpm. The FEM results for shearing motion and solid fraction were compared with experimental results from a granular shear cell.Copyright © 2009 by ASME
Total 17-ketosteroid excretion in normal and ovariectomized rabbits.

Summary1. Total 17-ketosteroid urinary levels have been determined for normal and ovariectomized rabbits. There is no statistical difference between them. 2. The ratio between urine volume and 17-ketosteroid excretion has been examined statistically and no correlation found.
Human Control in Rotated Frames: Anisotropies in the Misalignment Disturbance Function of Pitch, Roll, and Yaw

Comparative misalignment disturbance functions (MDF) have been measured for rotations between display and control axes for pure pitch, roll, and yaw misalignments in a high fidelity virtual environment. Twenty participants manually moved a virtual cursor using position control to touch 3-dimensionally, randomly presented nearby targets having a constant Fitts Index of Difficulty. Results show a peak disturbance near 120° of rotation for all axes with Roll being distinguishably more disturbed. Some reasons for observed anisotropies, nonlinearities and an equiaxial spiral feature are briefly discussed and modeled
Applications of the quartz crystal microbalance to electrochemistry. Measurement of ion and solvent populations in thin films of poly(vinylferrocene) as functions of redox state

Etudes du transport du solvant, au cours de l'oxydation des couches minces de polyvinylferrocene (PVC), immobilisees sur la surface d'une electrode et qui montrent la nature des processus responsables des pics multiples observes sur les voltammogrammes. Cas des electrolytes contenant des ions ClO 4 − et PF 6 −
Recurrent condyloma acuminatum in women over age 40: association with immunosuppression and malignant disease.

Sixteen women aged ⩾40 years were studied within a total population of 77 women with recalcitrant condyloma acuminatum. Six of the 16 women (38%) were found to have coincident malignant disease ( p
Markets and childhood obesity policy

Summary In examining the childhood obesity epidemic from the perspective of economics, John Cawley looks at both possible causes and possible policy solutions that work through markets. The operation of markets, says Cawley, has contributed to the recent increase in childhood overweight in three main ways. First, the real price of food fell. In particular, energy-dense foods, such as those containing fats and sugars, became relatively cheaper than less energy-dense foods, such as fresh fruits and vegetables. Second, rising wages increased the “opportunity costs” of food preparation for college graduates, encouraging them to spend less time preparing meals. Third, technological changes created incentives to use prepackaged food rather than to prepare foods. Several economic rationales justify government intervention in markets to address these problems. First, because free markets generally under-provide information, the government may intervene to provide consumers with nutrition information they need. Second, because society bears the soaring costs of obesity, the government may intervene to lower the costs to taxpayers. Third, because children are not what economists call “rational consumers”—they cannot evaluate information critically and weigh the future consequences of their actions—the government may step in to help them make better choices. The government can easily disseminate information to consumers directly, but formulating policies to address the other two rationales is more difficult. In the absence of ideal policies to combat obesity, the government must turn to “second-best” policies. For example, it could protect children from advertisements for “junk food.” It could implement taxes and subsidies that discourage the consumption of unhealthful foods or encourage physical activity. It could require schools to remove vending machines for soda and candy. From the economic perspective, policymakers should evaluate these options on the basis of cost-effectiveness studies. Researchers, however, have as yet undertaken few such studies of obesity-related policy options. Such analyses, once available, will help policymakers achieve the greatest benefit from a fixed budget.
Breastfeeding and Gender Inequality

Many feminists have argued breastfeeding is a constraint that may prevent women from realizing nonmaternal opportunities. This article presents an alternative feminist perspective, arguing that the view of breastfeeding as a constraint glosses over the mediating role that gender inequality plays in the way breastfeeding impacts women's lives. Rather than focus on breastfeeding as a constraint, attention should be focused on the ways that socially created policies and practices, often based on a gender-similarity framework, sustain gender inequities. Policies and practices based on this framework negate the needs of the body, which exaggerates gender differences, redistributes gender inequities, and raise the costs of breastfeeding. In contrast, locating the constraint in the arena of gender inequality better explains how social decisions that differentially accommodate men's nonlactating bodies privilege men over women and help us recognize how passage of polices that accommodate lactating bodies represen...
THE STIMULATION OF POST-ILLUMINATION ATP SYNTHESIS BY VALINOMYCIN

A high-energy state or intermediate (XE) is formed in illuminated chloroplasts which can drive ATP formation in a dark reaction [l] . Since the characteristics of X, and of the light-induced H+ uptake [2] are similar, it has been proposed that XE is a gradient in H+ activity across chloroplast membranes. This view is substantiated by the finding that ATP formation may be driven in total darkness by an artificiallyproduced H+ gradient [3]. Nelson et al. [4] reported that the treatment of lettuce chloroplasts with digitonin inhibited H+ uptake and post-illumination ATP synthesis more severely than photophosphorylation. In our previous studies on phosphorylation in subchloroplast particles [ 5,6] , we concluded that H+ uptake in these particles was electrogenic and, furthermore, that a membrane potential might play a role in photophosphorylation. To test this idea further, the effects of valinomycin and K+ on post-illumination ATP synthesis and H+ uptake in subchloroplast particles were tested. These reagents were found previously [7] to enhance H+ uptake in R.rubrum chromatophores. In this paper, we report that valinomycin in the presence of K+ stimulated H+ uptake as well as the formation of X, in subchloroplast particles.
Angiotensin II potentiates ACTH-stimulated adrenal androgen secretion

Abstract Several lines of evidence in animal and human studies, including measurments of elevated adrenal androgens in salt wasting syndromes suggest that adrenal androgen levels may in part be regulated by angiotensin II. This possibility was tested directly by measurement of cortisol and dehydroepiandrosterone (DHA) in canine adrenal cell suspensions after addition of angiotensin II and ACTH, separately and together. Minimal cortisol and no DHA stimulation was obtained using 4 × 10 −10 to 4 × 10 −5 M concentrations of angiotensin II alone. However, increased cortisol and DHA secretion were observed beginning at 4 × 10 −10 M concentrations of angiotensin II when it was combined with 10 13 M ACTH. These are physiological concentrations of both stimuli and may explain the increased adrenal androgens seen in some pathological situations characterized by elevated PRA.
In situ dating on Mars: A new approach to the K–Ar method utilizing cosmogenic argon

Abstract Cosmogenic argon isotopes are produced in feldspars via nuclear reactions between cosmic rays and Ca and K atoms within the lattice. These cosmogenic isotopes can be used as proxies for K and Ca, much like nuclear reactor-derived 39Ar and 37Ar are used as proxies for K and Ca, respectively, in 40Ar/39Ar geochronology. If Ca and K are uniformly distributed, then the ratio of radiogenic 40Ar (40Ar⁎) to cosmogenic 38Ar or 36Ar (38Arcos or 36Arcos) is proportional to the difference between the radioisotopic and exposure ages, as well as the K/Ca ratio of the degassing phase. Thus cosmogenic, radiogenic, and trapped Ar isotopes, all of which can be measured remotely and are stable over geologic time, are sufficient to generate an isochron-like diagram from which the isotopic composition of the trapped component may be inferred. Such data also provide a means to assess the extent to which the system has remained closed with respect to 40Ar⁎, thereby mitigating otherwise unquantifiable uncertainties that complicate the conventional K–Ar dating method.
Landing site coverage for orbital lifting re- entry vehicles

Abstract : The problem of landing site coverage of orbiting vehicles with maneuvering capability is analyzed in this report. The first part deals with the determination of the latitude coverage of a landing site per orbital period for the re-entry vehicle with a given maneuver capability defined by a rectangulaaped landing footprint. The second part relates the required latitude coverage to guarantee that within a specific waiting time in orbit the vehicle would attain a position from which it could be deboosted from orbit and subsequently land at a preselected location. Extensive numerical results are ob tained and presented in convenient graphical form.
Reaction of triphenylphosphine with phenylethanethiolate-protected Au38 nanoparticles.

The replacement of phenylethanethiolate (SC2Ph) ligands on 1.1 nm (core diameter) Au38(SC2Ph)24 monolayer-protected clusters (MPCs) with varied amounts of triphenylphosphine (PPh3) is investigated in methylene chloride. UV−vis spectra suggest that changes in the MPC Au core size occur when large amounts (>10 equiv moles per cluster) of PPh3 are reacted with Au38(SC2Ph)24. 1H and 31P NMR spectra following the addition of smaller amounts (<5 equiv moles) of PPh3 indicate that the reaction liberates a AuISC2Ph complex, as opposed to a SC2Ph thiol, disulfide, or anion. A 1H NMR kinetic study shows that the exchange is surprisingly rapid, even faster than exchanges of thiolates with other thiolates, at room temperature and in air. The reaction is slowed when cooled or conducted under Ar. The difference in potentials of the initial one-electron voltammetric reduction and oxidation of Au38(SC2Ph)24 decreases slightly upon reaction with small amounts of PPh3.