cssi/SciSciGPT-SciSciNet huggingface dataset:
Management-Based Regulation: Using Private Management to Achieve Public Goals

We examine a rapidly emerging regulatory approach that we label management-based regulation. Management-based regulation shifts the locus of policy discretion from the government regulator to the regulated entity. Government directs private firms to incorporate public goals into their management practices, and provides general guidelines by which private management will be judged. We outline the conditions under which management-based regulation is likely to be an appropriate government strategy and discuss three applications of this approach.
The purification and characterization of glutathione S-transferase from the hepatopancreas of the blue crab, Callinectes sapidus.

High glutathione S-transferase activity was found in the cytosol of F-cells from the hepatopancreas of the blue crab (Callinectes sapidus). Purification of glutathione S-transferase from hepatopancreas extracts by Sephadex G-200, DEAE-Sephacel, and chromatofocusing resulted in the isolation of two isozymes with isoelectric points of 5.9 and 5.7, as determined by analytical isoelectric focusing. Using 1-chloro-2,4-dinitrobenzene as the substrate the specific activities of the two purified isozymes were 222 and 182 μmol/min/mg, respectively. There was no evidence for basic transferase isozymes. In addition to 1-chloro-2,4-dinitrobenzene the purified glutathione S-transferase isozymes showed activity with p-nitrophenyl acetate, p-nitrobenzyl chloride, bromosulfophthalein, and benzopyrene oxide. Thus, both substitution and addition reactions associated with vertebrate glutathione S-transferase were found in the crab transferases. There was no activity when ethacrynic acid, methyl iodide, trans-4-phenyl-3-buten-2-one, 1,2-epoxy-(p-nitrophenoxy)propane, cumene hydroperoxide, and t-butyl hydroperoxide were used as substrates. The lack of peroxidase activity is of interest since this activity is commonly found in vertebrate transferase isozymes. The two transferases had a dimeric Mr of 40,800 with similar amino acid compositions and similar kinetic parameters (Vmax, Km, and pH maxima) with 1-chloro-2,4-dinitrobenzene as substrate. The two transferases could be distinguished by their isoelectric points, molecular mass of the monomers (22,300 for GST 1 and 22,300 and 22,400 for GST 2), and different inhibitor mechanisms with hematin and bromosulfophthalein.
Heating Thermal/Structural Analysis of a Thin Beam Window of Ultra Cold Neutron Test Facility

This paper is an analytical investigation of a proposed vacuum barrier window that isolates the proton beam transport vacuum envelope from the Ultra Cold Neutron (UCN) experimental target system at atmospheric pressure. The window is subjected to static pressure and cyclic thermal stresses as the accelerated particle beam passes through it and deposits a small amount of energy in the window. The analysis investigates various beam rms sizes for two beam delivery time structures. The 0.1-mm thick, 52 mm diameter window is made of inconel alloy 718 and is welded to the beamline tube at its outer edge. For some combinations of delivery time structure and beam size, the window under differential pressure and proton beam heating experiences stress that is well above yield and possibly large enough to break the inconel foil. In order to analyze the induced temperature and stress, a finite element model has been developed. The model has been written parametrically to allow the beam characteristics, window material properties, dimensions and mesh densities to be easily adjusted. The heat load is applied to the model through the use of a 3-dimentional table containing the calculated volumetric heat rates. The heat load is based on a radial distribution for a circular Gaussian beam under both normal and extensional operation cases. In this analysis, a radial-centered, circular beam is assumed. The results of several analyses are presented in this paper.Copyright © 2004 by ASME
Psychobiology of personality

1. Basic dimensions of personality 2. Consistency of personality 3. Behaviour genetics and personality traits 4. Neuropsychology 5. Psychopharmacology 6. Psychophysiology 7. Learning 8. Anxiety disorders 9. Antisocial personality and other disinhibitory disorders 10. Measures and models, problems and progress References Figure captions.
A new technique for pet slice orientation and MRI‐PET coregistration

We report and validate a technique for magnetic resonace imaging (MRI) positron emission tomography (PET) coregistration and the optimization of PET slice orientation that enhances and complements existing techniques. The technique depends on an external fiducial system and on software that models the relationship of the PET gantry with respect to a three-dimensional (3D) MR reconstruction of each subject's brain anatomy. The technique offers the possibility of using individual neuroanatomical information to plan PET activation studies. Estimated 3D errors average 3 mm in [15O]H2O PET activation studies. In-plane interinjection movement averages less than 1 mm. The resulting MRI-PET coregistration provides a basis for bringing neuroanatomical information to bear on a number of issues critical for the interpretation of functional imaging studies. © 1995 Wiley-Liss, Inc.
Instantaneous hyperemic flow-versus-pressure slope index. Microsphere validation of an alternative to measures of coronary reserve.

BACKGROUND The instantaneous hyperemic flow-versus-pressure (i-HFVP) slope index is a new method of assessing maximal coronary conductance and can be used as an alternative to conventional measures of coronary reserve. The i-HFVP slope index is determined by measuring the slope of the linear diastolic segment of the relation between instantaneous aortic pressure and hyperemic coronary flow. METHODS AND RESULTS To validate the i-HFVP slope index as a measure of maximal coronary conductance, we compared this method with a microsphere-derived measurement of maximal coronary conductance (m-HFVP slope index) by determining the slope of the least-squares regression line of the data points for coronary flow during maximal hyperemia and four or five steady-state alterations of aortic pressure in 43 dogs (open-chest, anesthetized preparations) with or without coronary stenoses. The i-HFVP slope index demonstrated no dependence on heart rate, left ventricular end-diastolic pressure, or mean aortic pressure and was highly reproducible within the groups studied (intraclass correlation coefficient, 0.86 for normal arteries, 0.87 for stenotic arteries, and 0.93 for combined groups; for all coefficients, p less than 0.001). The i-HFVP slope index was significantly decreased in the presence of a stenosis (10.3 +/- 3.9 for normal arteries versus 3.6 +/- 1.6 for stenotic arteries, p less than 0.001) as was the transmural m-HFVP slope index (8.9 +/- 4.6 for normal arteries versus 5.3 +/- 3.1, p less than 0.01). Of special importance, the i-HFVP slope index measurement for normal arteries was not significantly different from the transmural and subendocardial m-HFVP slope index measurements (10.3 +/- 3.9 versus 8.9 +/- 4.6 and 9.2 +/- 5.7, respectively). For stenotic arteries, the i-HFVP slope index measurement was also not significantly different from the transmural and subendocardial m-HFVP slope index measurements (3.6 +/- 1.6 versus 5.3 +/- 3.1 and 4.1 +/- 2.3, respectively). The i-HFVP slope index correlated best with subendocardial m-HFVP slope index measurements (correlation coefficient, 0.57; p less than 0.001). When the 95% confidence intervals for the transmural (or subendocardial) m-HFVP slope index in normal arteries were compared with the i-HFVP slope index values, the latter demonstrated a systematic trend to overestimate the m-HFVP slope index. In the presence of a stenosis, this effect was minimized, and the slope values were nearly identical. CONCLUSIONS The i-HFVP slope index correlates most closely with subendocardial coronary conductance; the index is a hemodynamically independent measure of coronary reserve that is reproducible over a broad range of aortic pressures; and the methodology is applicable to an intact circulation in experimental preparations and may with future developments also prove useful in humans.
How African American Men decide Whether or Not to Get Prostate Cancer Screening

Prostate cancer is the most commonly diagnosed cancer in men in the United States and affects African Americans disproportionately when compared to other ethnic groups. There are unclear reasons for this disparity, but several factors may include race, nutrition, family history of cancer, and screening. With early detection of prostate cancer, survival is much better; thus, screening may be helpful, especially for high-risk individuals. Prostate cancer screening continues to be controversial. A paucity of data exists on what prostate cancer screening means to African Americans, particularly in rural areas, and how they make the decision whether or not to undergo prostate cancer screening. This study interviewed 17 African American men to explore how and when they decided about prostate cancer screening. Most of the men (n = 9) said that they had prostate cancer screening. Three themes emerged from the data: (1) these men had information on prostate cancer; (2) family and friends played an important role in the men's decision-making process; and (3) for screening, it was necessary for the men to have a trusting relationship with their healthcare provider. These findings confirm that the decision-making process is not a simple process. The study's results can help healthcare providers understand some of the important decision-making factors in prostate cancer screening for African American men.
Urogenital Surgery Performed with the Mare Standing

Many urogenital procedures of the mare are commonly performed with the mare standing. Ovariectomy via colpotomy was described as early as 1903, and the Caslick vulvoplasty was first described in 1937. As knowledge expands and instruments become more specialized, techniques will improve. With the introduction of laparoscopy, clinicians have not only been able to improve the previously described urogenital procedures but also to devise new procedures. This article describes multiple surgeries of the female urogenital tract, all of which can be performed with the mare standing, and describes a variety of approaches to some portions of the female urogenital tract.
Force measurements of single and double barrier DBD plasma actuators in quiescent air

We present the results of our experimental measurements of how variations in the discharge geometry of surface-mounted dielectric barrier discharges (DBDs) affect the force transferred to atmospheric pressure air. Our studies include both single barrier plasma actuators (one electrode insulated) and double barrier plasma actuators (both electrodes insulated) operated in quiescent air. Stagnation probe measurements of the induced air flow and direct force measurements using an electronic balance show that, for both actuator types, parallel time-averaged forces increase as the high voltage electrode diameter decreases. For single barrier actuators, this increase is exponential rather than linear as previously reported in the literature. The data from the two measurement techniques are directly proportional to one another. When the variation of velocity and pressure on all sides of an actuator are considered, the techniques show quantitative agreement.
When can a classical electron accelerate without radiating

A classical point electron radiates when it accelerates. However, there are classical electron models with extended charge distributions which can accelerate and/or deform without radiating. Can a model be contrived that will undergo radiationless motion while accelerating (on the average) over a distance large compared to its size? The answer is no: we prove that the “center” of the electron is always closer than the electron “diameter” to a fictitious point undergoing constant-velocity motion, if the electron's motion is radiationless.
Ignimbrites, trachytes, and sedimentary rocks of the Precambrian Thunderbird Group, Franklin Mountains, El Paso, Texas

Metamorphosed trachytes, ignimbrites of rhyolitic composition, and volcaniclastic rocks are recognized in the Precambrian Thunderbird Group, Franklin Mountains, near El Paso, Texas. Chemically, both the trachytes and pyroclastic rocks are alkalic. Contact metamorphism due to intrusion of the Red Bluff Granite recrystallized the Thunderbird Group to the albite-epidote hornfels facies. However, primary igneous and sedimentary structures are well preserved, as seen both in outcrops and thin sections, throughout most of the Thunderbird Group.
Numerical investigation of cosmological singularities.

A primary unresolved issue for cosmological singularities is whether or not their behavior is locally of the Mixmaster type [as conjectured by Belinskii, Khalatnikov, and Lifshitz (BKL)]. The Mixmaster dynamics first appears in spatially homogeneous cosmologies of Bianchi types VIII and IX. A multiple of the spatial scalar curvature acts as a closed potential leading, in the evolution toward the singularity (say τ → ∞), to an (almost certainly) infinite sequence of bounces whose parameters exhibit the sensitivity to the initial conditions usually associated with chaos. Other homogeneous cosmologies are characterized by open (or no) potentials leading to a last bounce as τ → ∞ . Such models are called asymptotically velocity term dominated (AVTD). Here we shall describe a numerical approach to address the BKL conjecture. Starting with a symplectic numerical method ideally suited to this problem, we shall consider application of the method to three models of increasing complexity. The first application is to spatially homogeneous (vacuum) Mixmaster cosmologies where we compare the symplectic ODE solver to a Runge-Kutta one. The second application is to the (plane symmetric, vacuum) Gowdy universe on T3 × R. The dynamical degrees of freedom satisfy nonlinearly coupled PDEs in one spatial dimension and time. We demonstrate support for conjectured AVTD behavior for this model and explain its observed nonlinear small-scale spatial structure. Finally, we study U(1) symmetric, vacuum cosmologies on T3 × R. These are the simplest spatially inhomogeneous universes in which local Mixmaster dynamics is allowed. The Gowdy code is easily generalized to this model, although the spatial differencing needed in the symplectic method is not trivial. For AVTD models, we expect the potential-like term in the Hamiltonian constraint to vanish as τ → ∞ while in local Mixmaster it becomes (locally) large from time to time. We show how the potential behaves for a variety of generic U(l) models.
Sometimes there is nothing wrong with letting a child drown

Peter Singer argues that we�re obligated to donate our entire expendable income to aid organizations. One premiss of his argument is "If it is in your power to prevent something bad from happening, without sacrificing anything nearly as important, it is wrong not to do so." Singer defends this by noting that commonsense morality requires us to save a child we find drowning in a shallow pond. I argue that Singer�s Drowning Child thought experiment doesn�t justify this premiss. I offer my own Drowning Children thought experiment, which should reveal that commonsense morality entails that premiss two is actually false.
Efficacy of albendazole and mebendazole against Hymenolepis microstoma and Hymenolepis diminuta

An investigation of the chemotherapeutic effects of 2 anthelmintics, albendazole (ABZ, methyl 5-[propylthio]benzimidazole-2- carbamate) and mebendazole (MBZ, methyl 5-[benzoyl]benzimidazole-2-carbamate), on Hymenolepis microstoma and Hymenolepis diminuta in experimentally infected mice and rats is reported. Single (50 mg/kg) or multiple daily oral doses (50 mg kg-1 day-1 for 3 consecutive days) of MBZ had no effect on H. microstoma; at necropsy, the drug treated mice harbored appreciable numbers of the parasite in the bile duct and biliary passages. ABZ was also inactive when given as a single oral 50 mg/kg dose on day 27 PI. Better results were obtained when ABZ was administered at a dosage of 50 mg kg-1 day-1 for 3 consecutive days; the reduction in worm burden obtained with this treatment regimen was 50%. These results are in marked contrast to those obtained with the same anthelmintics against enteral H. diminuta in rats which succumbed at lower dosages. A review was made of the published reports on the pharmacokinetic behavior of these benzimidazole carbamate anthelmintics and a hypothesis for the inactivity of MBZ against H. microstoma is proposed.
U(1) gauge theory of the Heisenberg antiferromagnet.

The low-energy spin excitations in the flux phase of the (2+1)-dimensional large-$n$ $\mathrm{SU}(n)$Heisenberg antiferromagnet are relativistic fermions coupled to a U(1) gauge field. These excitations are studied in the physical $n=2$ case with the use of a $\frac{1}{n}$ expansion. A Chern-Simons term is included to remove gauge configurations forbidden in the $n=2$ theory.
Ammonia cometabolism and product inhibition vary considerably among species of methanotrophic bacteria.

Ecological studies have indicated that relative abundances of Gammaproteobacteria methanotrophs (Gamma-MOB) vs. Alphaproteobacteria methanotrophs (Alpha-MOB) in nitrogen (N) impacted soils are dictated in part by their abilities to tolerate inhibitory effects of ammonium and nitrite. In particular, ammonia is a cometabolic substrate and competitive inhibitor of methane monooxygenase. The rates of ammonia and hydroxylamine oxidation and inhibition of methane-oxidizing activity by ammonium and nitrite were compared among two Gamma-MOB and two Alpha-MOB to determine whether methanotrophs of the same class shared similar physiological profiles. Each isolate exhibited unique Km(app) for ammonia and Vmax for nitrite production with or without reductant (methane or sodium formate). The rates of nitrite production from hydroxylamine followed similar trends to rates of ammonia oxidation, indicating that hydroxylamine-oxidizing enzymes were central participants in the ammonia-oxidizing pathway. Methylomonas methanica was incapable of either ammonia or hydroxylamine oxidation. A broad range of sensitivities to ammonium and nitrite inhibition were measured with little consistency between isolates of the same class. The results indicate that physiological responses, and perhaps environmental adaptations, to N compounds are organism specific for methanotrophs.
Teratogenicity of 2-methoxyethanol applied as a single dermal dose to rats.

2-Methoxyethanol (2-ME) was applied as a single dermal dose on the backs of collared, pregnant Sprague-Dawley rats on Gestation Days (GD) 10, 11, 12, 13, or 14 at doses of 0 and 2000 mg/kg, and at doses of 0,250, 500, and 1000 mg/kg on GD 12. Except for a transient loss in body weight observed the day after 2-ME administration, no signs of maternal toxicity were observed. On GD 20, dams were necropsied and the fetuses evaluated for normal development. Resorptions were significantly (p < 0.05) increased in dams exposed to 2-ME on GD 10. Fetal body weights were reduced at dose levels of 1000 and 2000 mg/kg, but statistically significant differences were found only on GD 10 and 12. Significant increases in external, visceral, and skeletal malformations were observed in fetuses exposed to 2-ME at dose levels of 500 mg/kg or greater. Defects of the cardiovascular and urinary systems were the prominent visceral malformations observed. Limb defects (especially those pertaining to the digits) and vertebral column defects (primarily of the tail) were the most frequently observed skeletal defects. At the 2000 mg/kg dose level, 2-ME was teratogenic regardless of the GD of administration. Based on the results of this study, the no observed adverse effect level for developmental toxicity for a single dermal dose of 2-ME applied on GD 12 was determined to be 250 mg/kg.
Pulmonary edema; a complication of diabetic ketoacidosis

Hemodynamic evaluation in two patients and analysis of pulmonary edema fluid in one patient with diabetic ketoacidosis and acute pulmonary edema were performed. Pulmonary arterial wedge pressures in both patients were low or normal (1 and 9 mm Hg). In one patient the colloid osmotic pressure of the pulmonary edema fluid was 68 percent of the value of the serum. The serum colloid osmotic pressure-pulmonary arterial wedge pressure gradient in the second patient was markedly reduced. Pulmonary edema complicating diabetic ketoacidosis may be the result of increased permeability of pulmonary capillary membranes and altered intravascular colloid-hydrostatic forces.
Novel Nafion®/ORMOSIL hybrids via in situ sol-gel reactions: 2. Probe of ORMOSIL phase nanostructure by 29Si solid state NMR spectroscopy

Perfluorosulfonic Acid (PFSA)]/[Organically-Modified Silicon Oxide (ORMOSIL)] hybrids were formulated via sol-gel reactions of mixtures of tetraethoxysilane (TEOS) and diethoxydimethylsilane (DEDMS) in the nanophase-separated morphology of a PFSA membrane (Nafion®). The molecular structures of the ORMOSIL phases were investigated by 29Si solid state NMR spectroscopy and the spectra compared with those of corresponding bulk ORMOSILs. PFSA-in situ ORMOSIL composition can be tailored by manipulating TEOS/DEDMS source solution composition and quantified by 29Si solid state NMR spectroscopy. Copolymerization of TEOS and DEDMS monomers, rather than block formation, occurs within the PFSA as well as in the bulk. As DEDMS feed concentration increases, ORMOSIL nanostructures are more hydrophobic and more flexible. Dimethylsiloxane rings are dominant in PFSAs in which hydrolysis + condensation of pure DEDMS occurs.
Some new 2-resolvable Steiner quadruple systems

Zaicev, Zinoviev and Semakov [12] and, independently, Baker [1], constructed 2-resolvableS(3, 4, 4n) for all ℕ. However, no 2-resolvableS(3, 4,v),v≥4, were known for any other value ofv. In this paper, we construct infinite classes of 2-resolvableS(3, 4,v) for values ofv that are not a power of 4. In particular, we construct a 2-resolvableS(3, 4, 100).
Advisees' Expectations for Support as Moderator Between Advisor Behavior and Advisee Perceptions of Advisor Behavior

We tested relationships between students' expectations of psychosocial and career support through a peer advising program, the frequency of advisor behaviors consistent with these types of support ...
Texas Gains on NAEP: Points of Light?

The 1992-1996 gain in mathematics scores on NAEP from 4th to 8th grades in Texas is placed in perspective. The "miracle" in Texas looks much like the median elsewhere. Of 35 states and two districts (Guam and D.C.), the 52-point gain of Texas was good enough to earn Texas a rank of 17th or about the 46th percentile. Taking into consideration the wealth of states, Texas stands in the middle of the packno worse than most other states in delivering educational services to students.
Finite Element Method for Stochastic Beams Based on Variational Principles

This paper proposes a new version (fundamentally different from the existing ones) of finite element method for the mean and covariance functions of the displacement for bending beams with spatially random stiffness. Apart from the conventional finite element method for stochastic problems, which utilizes either perturbation or series expansion technique or the Monte Carlo simulation, the present method is based on the newly established variational principles. The finite element scheme is formulated directly with respect to the mean function and covariance function, rather than perturbed components of the displacement. It takes into account an information on joint probability distribution function of the random stiffness to obtain the covariance function of the displacement. Therefore, the accurate solution can be obtained even if the coefficient of variation of the random stiffness is large, in contrast to conventional technique. Several examples are given to illustrate the advantage of the proposed method, compared with the conventional ones.
Simple theory of double-barrier tunneling

The author analyzes resonant electron tunneling in parallel-plane heterostructures that have a central well region enclosed by two generalized barriers, which are reflectors of the Bloch waves. A single Bloch pair is assumed for the central region as well as in the surrounding semi-infinite semiconductors. The transmission probability versus electron energy is obtained for this model in terms of the transmission probabilities of the two barrier elements taken separately and the quasi-classical transit time for the trapped electron to make one circuit of the central well layer. The implications and limitations of these results are briefly discussed. >
Association between serum vitamin D levels and colonic carcinomatous polyps.

Vitamin D has been postulated to play a role in colonic carcinogenesis by modulation of apoptosis and inhibition of angiogenesis. However, data supporting this theory are conflicting, and most studies include only Asians and Caucasians. This retrospective study aims to determine whether there is a correlation between an increased total vitamin D level and a lower incidence of carcinomatous polyps in a multi-race but predominantly Hispanic population in East Harlem, New York City. A case–control study was conducted involving all patients who underwent colonoscopy at Metropolitan Hospital Center in 2011 and who also had serum total vitamin D levels taken within 1 month before or after the date of colonoscopy. Total vitamin D levels and the presence of carcinomatous polyps were the main variables studied. Colonic polyp-positive (CP+) samples were designated as the case group, while colonic polyp-negative (CP−) samples were assigned to the control group. Logistic regression analysis was used to estimate odds ratio at a 95 % confidence interval. Adjusted variables were chosen a priori and included age, sex, race, smoking and alcohol history, body mass index, and folate and aspirin use. We identified 1,640 patients who underwent colonoscopy from January 1 to December 31, 2011. Of these, 136 also had a vitamin D serum level drawn within 1 month before or after the colonoscopy. Forty-three were CP+ and assigned to the cases group, and 93 were CP− and assigned to the control group. Thirty-five percent of the sample had total serum vitamin D levels of <20 ng/ml, and 65 % had total serum vitamin D levels 20–29 ng/ml. Using <20 ng/ml as a cutoff point, the association of vitamin D with CP+ was statistically nonsignificant. In a multivariate model using vitamin D levels of <20 and <30, the association with CP+ appeared stronger, though, here too, the associations were not statistically not significant. A post hoc analysis was done excluding vitamin D levels of 20–29. In this analysis, the association between vitamin D levels and colonic polyps grew stronger with increased cutoff levels with vitamin D level of <20, suggesting a threshold effect. Vitamin D levels, using two established cutoffs, are not significantly associated with increased odds of membership in the CP+ group. However, our data suggest a possible threshold effect of vitamin D at <30 ng/ml associated with increasing odds of being CP+.
The effect of vitamin D on aldosterone and health status in patients with heart failure

Abstract Background Vitamin D deficiency is associated with heart failure (HF) events, and in animal models vitamin D down-regulates renin-angiotensin-aldosterone system hormones. Methods Patients with New York Heart Association (NYHA) functional class II–IV HF and a 25OH-D level ≤37.5 ng/mL received 50,000 IU vitamin D3 weekly (n = 31) or placebo (n = 33) for 6 months. Serum aldosterone, renin, echocardiography, and health status were determined at baseline and 6 months. Results Mean age of participants was 65.9 ± 10.4 years, 48% were women, 64% were African American, mean ejection fraction was 37.6 ± 13.9%, 36% were in NYHA functional class III, and 64% were in class II. The vitamin D group increased serum 25OH-D (19.1 ± 9.3 to 61.7 ± 20.3 ng/mL) and the placebo group did not (17.8 ± 9.0 to 17.4 ± 9.8 ng/mL). Aldosterone decreased in the vitamin D group (10.0 ± 11.9 to 6.2 ± 11.6 ng/dL) and not in the placebo group (8.9 ± 8.6 to 9.0 ± 12.4 ng/dL; P = .02). There was no difference between groups in renin, echocardiographic measures, or health status from baseline to 6 months. Modeling indicated that variables which predicted change in aldosterone included receiving vitamin D, increasing age, African American race, and lower glomerular filtration rate. Conclusions Vitamin D3 repletion decreases aldosterone in patients with HF and low serum vitamin D. Vitamin D may be an important adjunct to standard HF therapy. Further study will assess if vitamin D provides long-term benefit for patients with HF.
Sickle-Cell Trait and Physical Training: Evidence for Improved Fitness

Sickle cell anemia is the first disease to be understood on a molecular level. 1 The amino acid valine replaces the normal glutamic acid residue at the sixth position of the β-globin chain, the consequence of a GAG to GTG codon mutation. The resultant sickle hemoglobin, or HbS (α 2 β s 2 ) has a peculiar tendency to self-associate and form long strands of polymer on deoxygenation, which leads to red cell morphologic changes and to abnormal rheologic properties in the microcirculation. 2 See also p 1140. The primary determinants of the rate and extent of hemoglobin S polymerization, at any given oxygen saturation, are the intracellular hemoglobin concentration and hemoglobin composition (fraction of S and non-S hemoglobins). In addition, the ambient temperature, 2,3-diphosphoglycerate concentration, and pH can affect the polymerization tendency, albeit to a lesser extent, under normal physiologic conditions. 2,3 Thus, the hemolytic and overall clinical severity of
Thermal stability of InN

Abstract The vapor pressure of InN has been determined experimentally using a static pressure measurement technique. The measurements give log 10 P N 2 = 9.78−13649/ T , and are in excellent agreement with previous calculations and, we believe, represent a significantly more accurate estimate of the thermal stability of InN. We estimate heats and entropies of formation to be -31.4 ± 1.6 kcal/mole and 22.4 ± 1.9 cal/K-mole, respectively.
FAD2 and FAD3 desaturases form heterodimers that facilitate metabolic channeling in vivo.

Plant desaturases comprise two independently evolved classes, a structurally well characterized soluble class responsible for the production of monoenes in the plastids of higher plants and the poorly structurally characterized integral membrane class that has members in the plastid and endoplasmic reticulum that are responsible for producing mono- and polyunsaturated fatty acids. Both require iron and oxygen for activity and are inhibited by azide and cyanide underscoring their common chemical imperatives. We previously showed that the Δ9 acyl-CoA integral membrane desaturase Ole1p from Saccharomyces cerevisiae exhibits dimeric organization, like the soluble plastidial acyl-ACP desaturases. Here we use two independent bimolecular complementation assays, i.e. yeast two-hybrid analysis and Arabidopsis leaf protoplast split luciferase assay, to demonstrate that members of the plant integral membrane fatty acid desaturase (FAD) family, FAD2, FAD3, FAD6, FAD7, and FAD8, self-associate. Further, the endoplasmic reticulum-localized desaturase FAD2 can associate with FAD3, as can the plastid-localized FAD6 desaturase with either FAD7 or FAD8. These pairings appear to be specific because pairs such as FAD3 and FAD7 (or FAD8) and FAD2 and FAD6 do not interact despite their high amino acid similarity. These results are consistent also with their known endoplasmic reticulum and plastid subcellular localizations. Chemical cross-linking experiments confirm that FAD2 and FAD3 can form dimers like the yeast Ole1p and, when coexpressed, can form FAD2-FAD3 heterodimers. Metabolic flux analysis of yeast coexpressing FAD2 and FAD3 indicates that heterodimers can form a metabolic channel in which 18:1-PC is converted to 18:3-PC without releasing a free 18:2-PC intermediate.
Suggestions for the Creation and Implementation of Tobacco Policy

When making policy suggestions regarding tobacco use, it is important to consider why tobacco use has proved such a difficult behavior to eradicate. The articles in this issue have identified a number of variables that we would be well served to consider when creating tobacco policy. First, tobacco use has been difficult to eradicate because of the addictive nature of nicotine. Even though many smokers wish to quit, the addictive nature of the product makes this difficult. A second variable that compounds this problem is that tobacco addiction typically begins in adolescence. The decision-making process used by adolescents that may lead to tobacco use may be particularly difficult to alter, thus making smoking initiation a difficult process in which to intervene. Finally, it is important to consider the political power of the tobacco industry and to identify promising methods of overcoming this power when creating policy. These might include innovative legal strategies and searching for compromises that can reduce tobacco use while protecting important tobacco constituencies.
Species Differences in the Induction of Time-Dependent Potentiation of Insulin Secretion*

The secretory responsiveness of the pancreatic beta-cell can be markedly improved by prior short term exposure to a stimulatory glucose level. Termed time-dependent potentiation (TDP), priming, or sensitization, this phenomenon has been documented to occur in both human and rat islets and my involve, at least in part, information flow in the phospholipase C and protein kinase C (PKC) signal transduction pathway. In contrast to human and rat islets, however, mouse islets fail to exhibit TDP in response to priming with high glucose. In the present series of studies, we explored in more detail the conditions and stimulants necessary for the induction of TDP in mouse islets and compared these responses with those obtained in rat islets. In agreement with previous reports, high (15 mM) glucose alone primed the rat beta-cell, but not the mouse beta-cell, to subsequent restimulation with 15 mM glucose. However, muscarinic stimulation of mouse islets with carbachol (100 microM) in the presence of 15 mM glucose pr...
Prevention of early-onset invasive neonatal group B streptococcal disease in a private hospital setting: the superiority of culture-based protocols.

Abstract Objective: In a large private tertiary care hospital we compared the two different approaches to group B streptococcal screening and intrapartum chemoprophylaxis suggested by The American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, and the Centers for Disease Control and Prevention: risk factor–based protocol and culture-based protocol. Study Design: A 2-year baseline period was followed by sequential prospective observational studies of the impacts of two different group B streptococcal management protocols, 3 years with the risk-based approach and 2 years with the culture-based approach of universal screening at 35 to 37 weeks' gestation. Results: During the baseline period the rate of early-onset group B streptococcal infection was 1.1 cases per 1000 births (n = 8 cases per 6829 births). With the risk-based strategy the rate was also 1.1 cases per 1000 births (15 cases/13,270 births). After we switched to the culture-based protocol for 2 years, there were no cases of early-onset group B streptococcal infections among 9304 births ( P =.001; χ 2 = 10.9). There were no increases in other early-onset infections or in antibiotic resistance. Conclusions: In our setting, which included good prenatal care and good communication between laboratories and the hospital, the approach based on maternal culture at 35 to 37 weeks' gestation and treatment during labor of all patients with positive results significantly reduced early-onset group B streptococcal infections without increasing infections from resistant organisms. (Am J Obstet Gynecol 2000;182:1344-54.)
Neutralizing Ageism in Critical Care via Outcomes Research

Ageism, as a mind-set, amplifies a belief that intensive care for the elderly is ineffectual. However, there are little data to support the notion that advanced chronological age alone predicts unfavorable outcomes in response to intensive care. A lack of outcome data, combined with ageism, may place older patients at risk for rationing of intensive care. Currently, neither public policy nor cultural norms directly support a limitation in services to the elderly. However, as pressure to reduce health care costs increases, critically ill elderly patients may be targeted for rationing. In this context, outcomes research involving elderly populations is crucial. The purpose of this report is to explicate the risk of ageism in the delivery of intensive care and to describe methods for implementing outcomes assessment for critically ill elderly patients as an essential element in a continuum of care.
Proinflammatory cytokines regulate FcαR expression by human mesangial cells in vitro

IgA nephropathy (IgAN) is defined by the predominant deposition of IgA immune complexes (IC) in the glomerular mesangium. Interaction between IgA immune complexes and mesangial cells (MC) could be a linchpin for the genesis of IgAN. We studied the modulation of MC expression of IgA receptors (Fc alphaR) by selected cytokines. Binding of 125I-IgA to quiescent human MC showed 2.55 x 10(5) sites/cell with an affinity (Ka) of 3.2 x 10(7) M(-1). Addition of selected recombinant cytokines had no significant influence on Ka, but increased the number of sites/cell relative to unstimulated cells. Northern hybridization using the pHuFc alphaR cDNA probe showed time-dependent increases in mRNA expression in stimulated versus control cells. IL-6 and tumour necrosis factor-alpha (TNF-alpha) had a biphasic effect on the Fc alphaR mRNA level; at 48 h, IL-6 increased steady state mRNA levels about six-fold relative to control, TNF-alpha increased mRNA four-fold, and interferon-gamma (IFN-gamma) induced Fc alphaR mRNA two-fold. By reverse transcriptase-polymerase chain reaction (RT-PCR), the Fc alphaR expressed on human MC appears highly homologous to that expressed by U937 cells. Altered Fc alphaR expression in response to cytokines may influence the pathogenesis of IgAN by affecting deposition and/or clearance of IgA-IC in the mesangium.
Selective production of sealed plasma membrane vesicles from red beet (Bete vulgaris L.) storage tissue

Abstract Modification of our previous procedure for the isolation of microsomal membrane vesicles from red beet (Beta vulgaris L.) storage tissue allowed the recovery of sealed membrane vesicles displaying proton transport activity sensitive to both nitrate and orthovanadate. In the absence of a high salt concentration in the homogenization medium, contributions of nitrate-sensitive (tonoplast) and vanadate-sensitive (plasma membrane) proton transport were roughly equal. The addition of 0.25 m KCl to the homogenization medium increased the relative amount of nitrate-inhibited proton transport activity while the addition of 0.25 m KI resulted in proton pumping vesicles displaying inhibition by vanadate but stimulation by nitrate. These effects appeared to result from selective sealing of either plasma membrane or tonoplast membrane vesicles during homogenization in the presence of the two salts. Following centrifugation on linear sucrose gradients it was shown that the nitrate-sensitive, proton-transporting vesicles banded at low density and comigrated with nitrate-sensitive ATPase activity while the vanadate-sensitive, proton-transporting vesicles banded at a much higher density and comigrated with vanadate-sensitive ATPase. The properties of the vanadate-sensitive proton pumping vesicles were further characterized in microsomal membrane fractions produced by homogenization in the presence of 0.25 m KI and centrifugation on discontinuous sucrose density gradients. Proton transport was substrate specific for ATP, displayed a sharp pH optimum at 6.5, and was insensitive to azide but inhibited by N′-N-dicyclohexylcarbodiimide, diethylstilbestrol, and fluoride. The Km of proton transport for Mg:ATP was 0.67 m m and the K0.5 for vanadate inhibition was at about 50 μ m . These properties are identical to those displayed by the plasma membrane ATPase and confirm a plasma membrane origin for the vesicles.
Analysis of the pediatric outcomes data collection instrument in ambulatory children with cerebral palsy using confirmatory factor analysis and item response theory methods.

Background: Traditional use of the Pediatric Outcomes Data Collection Instrument (PODCI) assumes that all items have the same structure, are measuring the intended constructs, and assess the right levels of function to show change after orthopaedic or neurological intervention. Item response theory (IRT) methods can statistically account for inherent differences in PODCI item characteristics and thus reveal attributes of the measure important to effectiveness research. Our study uses IRT methods to determine whether PODCI items fit the projected dimensional structure of the PODCI, assess function on each dimension at the right level for a population of ambulatory children with cerebral palsy (CP), and reveal changes after intervention in this population. Methods: Proxy-reported PODCI questionnaires for 570 ambulatory children with CP were randomly divided into 2 groups for model creation and model testing using exploratory and then confirmatory factor analysis. The resulting model was compared with the projected dimensional structure, tested for fit of individual items, and examined for gaps and ceiling effects. Response changes at 1 year were compared between those with (n = 91) and without (n = 284) surgical intervention using paired t tests. Results: Factor analysis reduced the projected dimensions from 5 to 4 for this population, resulting in dimensions for mobility, upper extremity function (UEF), comfort and general health, and self-worth. All but 3 items fit their respective dimensions; ceiling effects were noted in 3 dimensions. Responses showed changes in the comfort and general health, mobility, and UEF dimensions in those who had surgery; in those children who did not have surgery, only the UEF responses changed. Conclusions: The PODCI can show change after intervention when data are analyzed using IRT methods. Ceiling effects in 3 dimensions may limit the amount of change the PODCI can show in a population of ambulatory children with CP. Level of Evidence: Level II. This was a retrospective investigation of a diagnostic tool, the PODCI, using a randomized cross-sectional design for model development, and a case-control design to assess sensitivity to change.
Patient navigation: a community centered approach to reducing cancer mortality.

Background Profound advances in biomedical science have contributed to increased longevity and improved quality of life for many Americans. Despite this progress, a heavier burden of disease is borne by some population groups in the United States, particularly the poor and underserved. Landmark reports published since 1973 have highlighted these health disparities, explored their causal factors, and outlined strategies to reduce them. More recent research studies underscore the results of these early reports that identify social position, economic status, culture, and environment as critical determinants of who develops and survives cancer and of the quality of life of cancer survivors. Methods The Patient Navigation Program was established in Harlem, New York, in 1990 to address the dramatic disparities in breast cancer mortality among minority women in the community. Results and conclusions The success of the Harlem Patient Navigation Program has provided the impetus for the development of many similar patient navigation programs across the country and for federal support for Patient Navigation research to address the critical need for effective interventions to eliminate cancer health disparities, particularly among minorities and the underserved.
Computation of vision operators in hypercube processors

Abstract Five low-level vision algorithms have been implemented on a 16-node iAPX 286/287 processor-based hypercube system (AMETEK S-14) by exploitation of its network embedding feature. This includes edge detection with the Sobel operator, histogramming, one-pass parallel binary image thinning, and noise-cleaning. The primary objective is to parallelize these algorithms in the ring and mesh networks of the S-14 hypercube system and to determine the actual speedup factor of parallel implementation over the sequential programming. Four 512 × 512 gray-level images have been processed concurrently in S-14 and a tenfold improvement in the speedup has been obtained compared to the sequential implementation in an iAPX 286/287 uniprocessor system (e.g. a single processor of S-14). This result implies that parallel implementation of vision operators on the relatively inexpensive array processor S-14 is ten times faster than sequential execution. It is also shown that the mesh topology of S-14 is more suitable for window convolution than the ring network of S-14.
Pi-donor intercalate polymers: synthesis, charge-transfer interactions, and applications

When low-ionization-potential organic donor molecules D such as tetrathiafulvalene, ferrocene, or triarylpyrazolines are chemically attached to a polymer backbone, a number of interesting and potentially useful phenomena are observed in films of the resulting polymers. For example, chemical oxidation, irradiation, or electrochemical treatment of these materials leads to a series of polymers, poly[D x (D + A − ) 1-x ], where D is the polymer-coupled organic molecule, x is the extent of oxidation, and A − is the charge-compensating anion. Depending on the nature of the bound donor group, these polymers exhibit two kinds of electronic interactions between donor sites which are of charge-transfer origin. These phenomena are responsible for several important properties of this new class of materials that make them interesting as polymer-modified electrodes, as semiconducting polymers, and a high-resolution electron-beam (or x-ray) resists.
Wideband 3-mm SIS mixers operated with partial saturation

We built fixed-tuned SIS mixers for use between 70 and 115 GHz on the Berkeley-Illinois-Maryland Association (BIMA) array. The mixers are similar to 215 GHz SIS devices designed by R. Blundell et al. Our 1.4 X 1.4 micrometer Nb/Al-Al2O3/Nb junctions have extremely sharp I-V characteristics, with Rsg/Rn approximately 40, and (omega) RC approximately 2. Heterodyne tests were made with a temperature-regulated vane mounted in the input waveguide to the mixer block. With vane temperatures of 20 and 35 K, we measure double sideband receiver temperatures Trcvr of 17 K from 80 to 115 GHz. Some gain compression occurs for input load temperatures greater than 50 K. Hence, with vane temperatures of 85 and 280 K we measure Trcvr approximately 35 K. Similar noise temperatures are measured with 77 and 295 K loads mounted outside the dewar. Because the mixers are partially saturated, we bias the junctions approximately 0.1 mV above or below the gain maximum, where the receiver response is a nearly linear function of the input signal level. This yields Trcvr of 35 - 40 K and makes it possible to calibrate the receivers on the telescopes using the standard chopper wheel method. With no LO power applied to the mixer, we observe a small IF signal which is proportional to the square of the input load temperature; we believe this is due to self-mixing of blackbody photons in the junction.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.