cssi/SciSciGPT-SciSciNet huggingface dataset:
A model for kinetic isotope fractionation during redox reactions

Abstract Stable isotopes are used to track redox reactions in both ancient and modern geochemical systems. However, because the magnitude and even the direction of fractionation depend on the reaction pathway, extracting information about redox conditions from isotopic signatures is difficult. Quantitative understanding of the fundamental thermodynamic controls on redox-driven fractionation may improve the reliability of fractionation models in natural systems. Here we develop a mechanistic framework based on Marcus electron transfer theory to model redox-driven kinetic isotope fractionation as a function of the corresponding equilibrium fractionation and thermodynamic parameters. The framework predicts that for related reactions, (1) kinetic fractionation during electron transfer should be proportional to and in the same direction as equilibrium fractionation and (2) the magnitude of kinetic fractionation should decrease linearly as the standard free energy of the reaction decreases and the reaction becomes more thermodynamically favorable. Furthermore, kinetic fractionation should be log-linearly correlated with the rate constant of electron transfer, such that a faster redox reaction induces less kinetic fractionation. To illustrate the application of the model to stable isotope systems, we discuss examples of kinetic isotope fractionation during reduction of chromium (VI) and nitroaromatics by aqueous and solid-phase reductants respectively. For both these systems, altering the standard reduction potential of the reductant to vary the standard free energy of the redox reaction produces large changes in the magnitude of kinetic fractionation, which can be quantitatively predicted with our model. The proposed framework thus may be valuable for modeling redox-driven kinetic isotope fractionation in a broad range of geochemically relevant systems for both traditional light stable isotopes (e.g., nitrogen) and nontraditional metal isotopes (e.g., chromium).
Inflows and Outflows in the Dwarf Starburst Galaxy NGC 5253: High-Resolution HI Observations

VLA and Parkes 64 m radiotelescope 21-cm observations of the starburst dwarf galaxy NGC 5253 reveal a multi-component non-axisymmetric HI distribution. The component associated with the stellar body shows evidence for a small amount of rotational support aligned with the major axis, in agreement with optically measured kinematics and consistent with the small galaxian mass. Approximately 20-30% of the HI emission is associated with a second component, an HI "plume" extending along the optical minor axis to the southeast. We consider outflow, inflow, and tidal origins for this feature. Outflow appears improbable, inflow is a possibility, and tidal debris is most consistent with the observations. These observations also reveal a filamentary third component that includes an 800 pc diameter HI shell or bubble to the west of the nucleus, coinciding with an Halpha shell. The mass of HI in the shell may be as large as ~4x10^6 Msun. This large mass, coupled with the lack of expansion signatures in the neutral and ionized gas (v<30 km/s), suggests that this feature may be an example of a starburst-blown bubble stalled by interaction with a massive neutral envelope. Many other HI kinematic features closely resemble those seen in Halpha emission from the ionized gas, supporting the interpretation of neutral and ionized gas outflow at velocities of ~30 km/s. Comparison between extinction estimates from the Balmer emission-line decrement and the HI column densities suggest a gas-to-dust ratio 2-3 times the Galactic value in this low-metallicity (Z=1/4 Zsun) galaxy.
Gender Differences in Quality of Life and Preferences for Location‐specific Amenities across Cities

The quality of life literature revealed the role that natural resources and local consumption amenities play in household preferences for cities and their growing importance in determining the success of cities. As women's control over household resources has increased, a growing body of consumer behavior literature has been documenting gender differences in preferences for consumer goods. Yet, the quality of life literature does not seem to make any distinction along gender lines in determining preferences for local consumption amenities. We estimate the quality of life across US cities separately for unmarried men and women, and using a rich set of location‐specific amenities, examine which amenities cause preferences to differ between men and women. Our results suggest that men and women's valuations of cities are correlated, suggesting commonality in preferences for many location‐based amenities, most notably natural resources, but there are also important deviations in valuations especially for local public goods and gender role attitudes.
Recursive Bivariate Probit Analysis of Injury Severity and Non-Truck Improper Actions in Large Truck-Related Crashes on Florida Suburban Roads:

This study investigated the hierarchical connection among injury severity, non-truck improper actions, and contributing factors in large-truck-involved crashes. Data for 4 years (2011–2014) of cras...
The azithromycin to prevent wheezing following severe RSV bronchiolitis-II clinical trial: Rationale, study design, methods, and characteristics of study population.

Abstract Severe respiratory syncytial virus (RSV) bronchiolitis in early life is a significant risk factor for future recurrent wheeze (RW) and asthma. The goal of the Azithromycin to Prevent Wheezing following severe RSV bronchiolitis II (APW-RSV II) clinical trial is to evaluate if azithromycin treatment in infants hospitalized with RSV bronchiolitis reduces the occurrence of RW during the preschool years. The APW-RSV II clinical trial is a double-blind, placebo-controlled, parallel-group, randomized trial, including otherwise healthy participants, ages 30 days-18 months, who are hospitalized due to RSV bronchiolitis. The study includes an active randomized treatment phase with azithromycin or placebo for 2 weeks, and an observational phase of 18–48 months. Two hundred participants were enrolled during three consecutive RSV seasons beginning in the fall of 2016 and were randomized to receive oral azithromycin 10 mg/kg/day for 7 days followed by 5 mg/kg/day for an additional 7 days, or matched placebo. The study hypothesis is that in infants hospitalized with RSV bronchiolitis, the addition of azithromycin therapy to routine bronchiolitis care would reduce the likelihood of developing post-RSV recurrent wheeze (≥3 episodes). The primary clinical outcome is the occurrence of a third episode of wheezing, which is evaluated every other month by phone questionnaires and during yearly in-person visits. A secondary objective of the APW-RSV II clinical trial is to examine how azithromycin therapy changes the upper airway microbiome composition, and to determine if these changes are related to the occurrence of post-RSV RW. Microbiome composition is characterized in nasal wash samples obtained before and after the study treatments. This clinical trial may identify the first effective intervention applied during severe RSV bronchiolitis to reduce the risk of post-RSV RW and ultimately asthma.
Reseña del libro Martin Heidegger. Metapolítica. Cuadernos Negros (1931-1938)

Resena del libro de Julio Quesada, (2019), Martin Heidegger. Metapolitica. Cuadernos Negros (1931-1938) , Editorial Aula de Humanidades, Coleccion Hermeneutica y Fenomenologia, Bogota.
Dietary supplement use and documentation in a breast cancer survivorship clinic.

Breast cancer survivors take vitamins and supplements to bolster their general health and to decrease the risk of cancer recurrence. Healthcare providers are frequently unaware of their patients non-prescription supplement use. The aim of this study was to study the type and the documentation of patients’ dietary supplements and vitamins in the electronic medical record (EMR). 50/51 female breast cancer survivors seen over a 7 week period consented to the study. Mean age was 70 and mean years since diagnosis was 13.9. Informed consent and documentation of supplement and vitamin use was obtained by the nurse practitioner the day before the visit. Study data were collected and managed using REDCap electronic data capture tools hosted at Weill Cornell Medicine. Of the 50 study patients, 90% were taking one or more vitamins and/or supplements (mean = 2.4, range = 1–9). The most common were Vitamin D, calcium, and vitamin C. Reasons for vitamin and supplement use included the recommendation by their physician or friend and prevention of bone loss or catching a cold. Five patients mentioned immunity or prevention of COVID-19. The patient reported list was compared with the medication list used by multiple providers in the electronic medical record (EMR). None of the 50 study patients had an accurate list of their vitamins and supplements in the EMR. 90% of the breast cancer survivors in our study were taking dietary supplements for a variety of reasons. None had an accurate list in the EMR. We strongly recommend more attention to accurate and easily accessed vitamin and supplement recording by providers.
Does phylogenetic distance aid in detecting environmental gradients related to species composition

Questions: How should we evaluate the success of new distance measures combining community abundance and phylogenetic information? How do we interpret ordinations using these metrics? Methods: We generated synthetic data along a known environmental gradient with two hypothetical underlying phylogenetic structures: niche phylogenetically conserved or dispersed along a gradient. We also examined tree species composition associated with gradients in elevation and longitude in Oregon, USA. NMS ordinations of plots in species space from phylogenetic (PD) and Sorensen distance (SD) matrices allowed comparison of the use of PD in different scenarios. Results: PD caused plots to cluster based on the clades that they contained, reducing stress with the synthetic data but not with the real example. Phylogenetic distance highlighted clades related to gradients when these were associated. When phylogeny was not conserved along a gradient, that gradient was less strong. Regardless of phylogenetic conservation, NMS using SD consistently extracted the strongest gradients in species composition. Conclusions: The success of PD should be evaluated on how well it extracts gradients in species composition and allows community ecologists to determine which gradients are partially explained by phylogeny and not based on its ability to reduce ordination stress. PD ordinations can help community ecologists interpret niche conservation but may obscure gradients related to species composition when niches are not conserved along the gradient of interest at the scale of the study.
Vortices in Nonlocal Condensate Models of Superfluid Helium

Nonlocal nonlinear Schrodinger equations are considered as models of superfluid helium. The models contain a nonlocal interaction potential that leads to a phonon-roton-like dispersion relation. It is shown that for any such potential the generalized Gross-Pitaevskii (GP) model has non-physical features, specifically the development of catastrophic singularities and unphysical mass concentrations. The GP equation is remedied by introducing a higher order term in the local density approximation for the correlation energy. The resulting theory is applied in two ways. The family of superfluid vortex rings is derived. The nucleation of vortex rings by a moving ion is considered.
Digital Dilemmas: How Elementary Preservice Teachers Reason about Appropriate Computer and Internet Use and Their Predictions of Students’ Judgments and Justifications

With increased computer technology use in schools, preservice teachers must be prepared to deal with ethical issues involved in a range of computer uses, such as students plagiarizing from the Internet or accessing adults-only web sites. We investigated preservice teachers’ judgments regarding several scenarios of student uses of the computer and Internet. Results show that most of the preservice teachers believed that appropriate uses of the computer and Internet involve specific classroom and school rules rather than universal considerations. We also asked the preservice teachers to predict elementary school students’ responses to the same scenarios. Preservice teachers were at times able to predict students’ judgments for whether the behavior was appropriate; however, they were unable to explain why students made those judgments. Our findings provide valuable information for teacher education programs on how preservice teachers can be better prepared for classroom incidents and, in turn, can help students understand the issues involved in various uses of the computer and Internet.
The regulation of purine utilization in bacteria. II. Adenine phosphoribosyltransferase in isolated membrane preparations and its role in transport of adenine across the membrane.

Abstract The uptake of adenine by membrane vesicles of Escherichia coli is accompanied by its conversion to AMP and is stimulated by P-ribose-PP. The pH optimum for uptake in phosphate buffer is 7.8. The Km for adenine is 20 µm and for P-ribose-PP is 200 µm. Uptake is inhibited by AMP and ATP. Adenine phosphoribosyltransferase activity is associated with membrane vesicles. A role of this enzyme in the uptake of adenine is indicated by the fact that the uptake and enzyme activity are similarly affected by variations in pH, substrates, and inhibitors; moreover, removal of the enzyme from the vesicles results in a concomitant loss of uptake activity. The enzyme isolated from membrane vesicles appears to be identical with the soluble enzyme isolated directly from cell-free extracts.
Forecasting dynamics and convergence to market fundamentals: Evidence from experimental asset markets

Abstract Subjects trade shares of a fictitious asset in a computerized double-auction market and submit one-period ahead forecasts of the mean contract price. On average, the predictions of the Rational Expectations Hypothesis are not supported and forecasts tend to be both biased and inconsistent with the specification of the process which would generate prices in a Rational Expectations Equilibrium. Nevertheless, an empirical analysis of agents' forecasting dynamics indicates that learning does occur, and that agents' forecasts evolve in a direction consistent with a Rational Expectations Equilibrium.
The Public Librarian and Service Ethics

The relationship between personal and professional ethics is examined from the standpoint of the public librarian. Librarians' personal attitudes and the service philosophy implicit in public librarianship often suggest contradictory responses to information or service requests which are personally offensive to the librarian, resulting in ethical dilemmas. Examples of such dilemmas are given: reasons for their occurrence and different opinions regarding ethical behavior are discussed. This type of conflict is itself neither good nor bad, but must be acknowledged by librarians and dealt with by the profession. Existing ethics of service guidelines are reviewed, and recommendations for resolving ethical conflict are offered.
Functional mapping of horizontal connections in developing ferret visual cortex: experiments and modeling

In cat striate cortex, patchy horizontal axonal projections link columns of similar orientation specificity. To assess the physiological correlates of such clustered projections, a new multisite stimulation technique was used to functionally map the pattern of horizontal synaptic inputs onto single layer 2/3 cells within tangential slices of developing ferret visual cortex. Twenty-four separate sets of horizontal fibers were stimulated within a 1200 microns strip of cortex, while evoked synaptic responses were recorded using whole-cell patch methods. For most cells, input maps demonstrated the presence of clustered horizontal connections in which multiple strong and weak synaptic responses were alternately evoked across the stimulated cortical region. Recordings from up to nine cells in a single slice revealed that patterns of synaptic input were closely correlated for cells in close proximity, and that this correlation decreased with distance, with no correlation at distances greater than 500 microns. To determine whether these physiological results were consistent with the known anatomical linkage of iso-orientation columns by clustered horizontal connections, mathematical analysis and computer simulations were performed upon orientation tuning maps obtained from optical imaging of activity-dependent intrinsic signals in mature ferret visual cortex. Optical imaging revealed an organization of iso-orientation domains consisting of broad regions of cortex across which orientation preference smoothly varied, together with “orientation centers” around which orientation preference was arranged in a pinwheel manner. The distribution of synaptic connections between different cortical sites was simulated by a model of functionally linked iso- orientation columns. Simulated synaptic input maps, generated by the same stimulation and recording arrangements used in our experimental protocol, accurately reproduced the observed patterns of clustered inputs onto experimentally recorded cells. These results indicate that even at the time of eye opening, prior to extensive visual experience, most cells receive patterns of synaptic inputs consistent with a clustered organization of horizontal connections that functionally link iso-orientation columns.
Role of nitric oxide resistance in erythropoietin-induced hypertension in rats with chronic renal failure

We studied the mechanism of erythropoietin (EPO)-induced hypertension (HTN) in rats with chronic renal failure (CRF). After partial nephrectomy, rats were randomized into four groups. Group A received EPO, 150 U/kg, two times weekly for 6 wk to prevent anemia; group B received placebo injections and became anemic; group C received EPO but was kept anemic by dietary iron deficiency; and group D received placebo and regular transfusions to match hematocrit (Hct) in group A. Blood pressure (BP), Hct, platelet cytosolic calcium ([Ca2+]i) and magnesium concentration, and pressor and vasodilatory responses were determined. By design, Hct in groups A and D were comparable and significantly greater (P < 0.01) than in groups B and C. Despite divergent Hct values, the EPO-treated groups A and C showed a significant rise in BP compared with the placebo-treated groups B and D. HTN occurred whether EPO therapy was begun immediately or 4 wk after nephrectomy. EPO therapy augmented the elevation of basal [Ca2+]i and restored the defective thrombin-mediated rise of platelet [Ca2+]i in CRF animals. EPO therapy did not alter caudal artery contraction in response to either 68 mM K(+)-induced depolarization, angiotensin II or alpha 1-agonist, methoxamine in vitro, or the pressor response to angiotensin II in vivo. However, EPO therapy impaired the hypotensive response to nitric oxide (NO) donors, sodium nitroprusside and S-nitroso-N-acetyl-D,L-penicillamine, and reversed the CRF-induced upregulation of guanosine 3',5'-cyclic monophosphate production by thoracic aorta in vitro. Thus EPO-induced HTN in CRF rats is Hct independent and is associated with and perhaps causally related to increased basal and stimulated [Ca2+]i and impaired vasodilatory response to NO.
Enhanced bioavailability and decreased clearance of analgesics in patients with cirrhosis.

The effect of moderate cirrhosis on the bioavailability and systemic clearance of three model analgesic compounds (pethidine, pentazocine, and salicylamide) with substantial first-pass metabolism was examined in 8 cirrhotic subjects and 4 agematched healthy controls. There was a 46% decrease in the clearance of pentazocine and a 278% increase in bioavailability. The corresponding figures for pethidine were 36% and 81%. The area under the plasma curve after oral salicylamide was increased by 551% in cirrhotic subjects compared with controls. This study demonstrated that drugs with the highest hepatic clearances will have the largest relative increases in bioavailability in cirrhotic patients due to portosystemic shunting. The decrease in clearance and increase in bioavailability will have multiplicative, rather than simply additive, effects on total area under the curve and, if related, pharmacologic response.
Cyclohept-1-en-3-yne

Abstract Cyclohept-1-en-3-yne rearranges thermally to toluene via cycloheptatriene, and to a mixture of 1- and 2-vinylcyclopentadiene an intermediate allene, 1-ethenylidenecyclo-2-pentene.
Hypoxia induces differential translation of enolase/MBP-1

Hypoxic microenvironments in tumors contribute to transformation, which may alter metabolism, growth, and therapeutic responsiveness. The α-enolase gene encodes both a glycolytic enzyme (α-enolase) and a DNA-binding tumor suppressor protein, c-myc binding protein (MBP-1). These divergent α-enolase gene products play central roles in glucose metabolism and growth regulation and their differential regulation may be critical for tumor adaptation to hypoxia. We have previously shown that MBP-1 and its binding to the c-myc P2 promoter regulates the metabolic and cellular growth changes that occur in response to altered exogenous glucose concentrations. To examine the regulation of α-enolase and MBP-1 by a hypoxic microenvironment in breast cancer, MCF-7 cells were grown in low, physiologic, or high glucose under 1% oxygen. Our results demonstrate that adaptation to hypoxia involves attenuation of MBP-1 translation and loss of MBP-1-mediated regulation of c-myc transcription, evidenced by decreased MBP-1 binding to the c-myc P2 promoter. This allows for a robust increase in c-myc expression, "early c-myc response", which stimulates aerobic glycolysis resulting in tumor acclimation to oxidative stress. Increased α-enolase mRNA and preferential translation/post-translational modification may also allow for acclimatization to low oxygen, particularly under low glucose concentrations. These results demonstrate that malignant cells adapt to hypoxia by modulating α-enolase/MBP-1 levels and suggest a mechanism for tumor cell induction of the hyperglycolytic state. This important "feedback" mechanism may help transformed cells to escape the apoptotic cascade, allowing for survival during limited glucose and oxygen availability.
Sudden cardiac arrest.

Sudden cardiac arrest continues to be a major public health challenge. Nearly 20% of all mortality in industrialized countries is due to sudden cardiac arrest. This is of epidemic proportion and remains a daunting problem. The actual incidence of sudden cardiac death is highly variable but recent prospective studies using multiple sources in the United States, Europe, and China have estimated sudden death rates ranging from 50 to 100 per one hundred thousand people in the general population. Despite the reduction in overall coronary heart disease mortality in the past thirty years, sudden cardiac death has not declined to a similar extent suggesting the percentage of deaths that are due to sudden cardiac arrest has remained fixed or actually increased as a percent of the total mortality. More than 50% of all coronary heart disease deaths are caused by sudden cardiac arrest. The exact nature of that sudden cardiac death has changed somewhat over the past two decades. While a vast majority of sudden cardiac arrest victims were felt to be due to ventricular tachycardia or fibrillation two decades ago, recent data suggests the percentage of people dying of ventricular tachycardia/fibrillation has decreased and incidence of sudden death associated with bradyarrhythmias has increased. This is probably an expression of an aging population within an increasing incidence of heart failure which demonstrates an inverse relationship to the degree of heart failure with the incidence of sudden cardiac death. Obviously death associated with end-stage heart failure is not going to be mitigated by wide spread implantation of an implantable defibrillator.
The role of direct‐care staff

This article examines the current role of direct-care staff, and their significance to individuals with disabilities living in the community. The role of staff will be redefined with respect to client normalization within the community. Finally, a framework for training staff is provided.
37°C E Rosettes in Various Malignant and Non‐malignant Disorders

Summary. T lymphocytes, forming sheep erythrocyte rosettes at 37°C, have been described in thymus glands, mitogen and allogeneic cell stimulated lymphocyte cultures, and acute T cell lymphoblastic leukaemia. This paper describes the finding of such lymphocytes in lymph nodes of a variety of disorders including Hodgkin's disease, Lennert's lymphoma, malignant lymphoma of large transformed T lymphocytes, immunoblastic lymphadenopathy, metastatic carcinoma, and other disorders. A large number of tonsils, but not reactive lymph nodes, also contained a significant number of those T lymphocytes. The significance of these findings in relation to interpretation of immune red cell rosettes and to the subclasses of T lymphocytes is discussed.
Study of the H/V spectral ratio method for determining average shear wave velocities in the Mississippi embayment

Abstract The shear wave velocity ( V S ) structure of the deep sediments in the Mississippi embayment is of interest to engineers and seismologists due to its influence on seismic wave propagation and site response during an earthquake. Although the shallow V S structure (top 30 to 60 m) is generally well characterized, information on the V S structure at greater depths (to 1000 m in some regions) is very limited. Past studies have developed relationships between the average V S ( V S,AVE ) of post-Paleozoic sediments in the embayment as a function of sediment thickness. One of these studies used converted body wave arrivals while the other used ambient noise measurements processed with the Horizontal-to-Vertical Spectral Ratio (HVSR) method. Interestingly, these two approaches yielded relationships that differed by about 25% to 30%. The objective of this study is to investigate the cause of the discrepancy between these relationships and identify the more reliable relationship for the V S structure in the Mississippi embayment. Experimental measurements of ambient noise were performed at eleven deep soil sites in the Mississippi embayment and analyzed using the HVSR method. The results from the experimental study yielded V S,AVE values that were consistent with findings from the previous HVSR study. However, simulations of body and surface wave propagation performed using estimated full-depth V S profiles at each site showed that the methodology used to develop the velocity–thickness relationship, specifically the approximate relationship used to relate site frequency, sediment thickness and V S , produces an overestimation of the true V S,AVE for the profile by 25 to 30%.
On the existence of optimal truth-dominant mechanisms

Abstract The existence of optimal dominant strategy mechanisms has been shown only for quadratic valuation functions. This paper shows that non-trivial Pareto-efficient and truth-dominant mechanisms exist for a slightly larger set of valuation functions.
Echocardiographic Pseudo Idiopathic Hypertrophic Subaortic Stenosis

chocardiography has been demonstrated to be a E very sensitive and specific noninvasive diagnostic method for the evaluation of patients with idiopathic hypertrophic subaortic stenosis ( IHSS ) It has been suggested that asymmetric hypertrophy of the left ventricle, with the interventricular septum at least 1.3 times as thick as the left ventricular free wall as identified by echocardiography, is the pathognomonic anatomic abnormality of IHSS.3.7 This finding, in conjunction with the characteristic systolic anterior motion of the anterior leaflet of the mitral valve which can also be identified by echocardiography, has been thought to be specific for the diagnosis of IHSS. The purpose of this report is to present a case of primary pulmonary hypertension simulating IHSS by the echocardiographic criteria mentioned above. on chest x-ray film. There was evidence of mild obstructive lung disease by pulmonary function tests. Cardiac catheterization revealed pulmonary hypertension with a systolic pulmonary artery pressure of 100 mm Hg. There was no evidence for an intracardiac shunt. There was no pressure gradient within the left ventricle either at rest or during provocative maneuvers and no evidence of mitral stenosis. Large central pulmonary arteries with rapid tapering of their branches was demonstrated by angiography. No evidence for pulmonary emboli was seen. Forward angiogram showed no evidence for IHSS. An echocardiogram obtained during hospitalization (Fig 1 ) showed asymmetric septal hypertrophy with gross thickening of the interventricular septum. In systole a distinct anterior motion of the anterior mitral ledet began soon after the onset of systole and returned to meet the posterior ledet before the end of systole. The right ventricular dimension ( not shown well in Fig 1 ) was enlarged.
Neutrons in the Nucleus. II

In Part I we came to the conclusion, that in several cases the lightest isotope of an element represents an arrangement of neutrons in more or less closed shells, that the heavier isotopes indicate the attachment of one neutron after the other, until with the heaviest isotope a new outer shell is completed. In the present paper we account for the number of neutrons in the nuclei by the following model. Up to Z = 16 the neutrons populate a first shell with at most two neutrons. From Z = 17 to 28 an additional shell of four neutrons is allowed. From Z = 32 to 36 we see the presence of neutrons in a third shell of eight. It is necessary to assume that between Z = 36 and 40 the inner shells are filled in with two more neutrons, and the same between Z = 50 and 54. Evidence for this filling in is seen in certain significant features of the binding energy. It is pointed out that the intensity distribution of the isotopes points to their stability with respect to a and r transformations. This can be used to give a more rational basis to the art of predicting missing isotopes.
Skewed differentiation of bone marrow CD34+ cells of tumor bearers from dendritic toward monocytic cells, and the redirection of differentiation toward dendritic cells by 1α,25-dihydroxyvitamin D3

Tumor presence is detrimental to the development of antigen-presenting dendritic cells. Since dendritic cells can arise from CD34+ precursor cells, the present study assessed the capacity of bone marrow CD34+ cells from tumor bearers to develop into dendritic cells when cultured in the absence of either tumor cells or their products. Culturing bone marrow CD34+ cells from mice bearing Lewis lung carcinomas yielded a lower number of dendritic cells than arose from CD34+ cells of normal mice. This reduced yield of dendritic cells was associated with a shift to development of monocytic cells and a reduced antigen presenting capability by the cultures. When the CD34+ cell cultures from tumor bearers were supplemented with the differentiation-inducing hormone 1alpha,25-dihydroxyvitamin D3, there was the restoration of dendritic cell development and antigen presenting ability. These results show that CD34+ cells from tumor bearers remain defective in their development into dendritic cells even when cultured outside the tumor environment, but development of dendritic cells can be restored with 1alpha,25-dihydroxyvitamin D3.
Effects of dietary interventions on incidence and progression of CKD

Traditional strategies for management of patients with chronic kidney disease (CKD) have not resulted in any change in the growing prevalence of CKD worldwide. A historic belief that eating healthily might ameliorate kidney disease still holds credibility in the 21(st) century. Dietary sodium restriction to <2.3 g daily, a diet rich in fruits and vegetables and increased water consumption corresponding to a urine output of 3-4 l daily might slow the progression of early CKD, polycystic kidney disease or recurrent kidney stones. Current evidence suggests that a reduction in dietary net acid load could be beneficial in patients with CKD, but the supremacy of any particular diet has yet to be established. More trials of dietary interventions are needed, especially in diabetic nephropathy, before evidence-based recommendations can be made. In the meantime, nephrologists should discuss healthy dietary habits with their patients and provide individualized care aimed at maximizing the potential benefits of dietary intervention, reducing the incidence of CKD and delaying its progression to end-stage renal disease. Keeping in mind the lack of data on hard outcomes, dietary recommendations should take into account barriers to adherence and be tailored to different cultures, ethnicities and geographical locations.
Mass margins spiculations: agreement between ratings by observers and a computer scheme

This study investigated the agreement between breast mass spiculation levels as rated subjectively by observers and a computer scheme. An image dataset with 1,263 mass regions was selected. First, three experienced observers independently rated subjectively the visualized spiculation levels of these mass regions and classified them into three categories (none/minimal, moderate, and severe/significant). We then developed a computerized scheme to detect mass margins and classify the spiculation levels of the suspected mass regions. The scheme applied a hybrid region growth algorithm to segment the mass regions. An edge map was computed inside a 30-pixel-wide band surrounding the mass boundary contour. The scheme then applied a threshold to convert the edge map into a binary image followed by labeling and detecting line orientation. In the original edge map the scheme computed the average local pixel value fluctuation. In the binary edge map, the scheme computed the ratio between the number of "spiculated" pixels and the number of total pixels inside the band. The scheme also computed mass region conspicuity using the original image. Using these three features, a Bayesian Belief Network (BBN) was built to classify mass regions into one of the three spiculation categories. We compared the inter-observer variation as well as agreement levels between the subjective and computerized ratings. Agreement rates between paired observers ranged from 41.3% to 58.8% (Kappa = 0.136 to 0.309). The agreement between the computer scheme and observers' average rating was 49.2% (Kappa = 0.218). This study demonstrated a large inter-observer variability in subjective rating of mass speculation levels as well as a large difference between the rating results of a computerized scheme and observers. As a result, in an Interactive Computer-Aided Diagnosis (ICAD) environment, CAD-selected reference regions may be considered "very similar" by some observers and "not similar" by others. Hence, improving the selection of actually visually similar reference regions by a computerized scheme remains an important yet unsolved task for ICAD development.
Quantitation of enzymatically generated hydrogen peroxide based on aqueous peroxyoxalate chemiluminescence

Abstract The method involves the reaction of 4,4′-{oxalyl bis[(trifluoromethylsulfonyl)imino]-ethylene}-bis(4-methylmorpholinium trifluoromethanesulfonate) with hydrogen peroxide in the presence of rhodamine-B. Precise measurements, with 1–3% relative standard deviation, can be made in both static and flow systems. In the flow system, the response to hydrogen peroxide is linear from 10−2 M hydrogen peroxide down to the limit of detection of 7 × 10−5 M.
The Politics of Culture: Race, Violence, and Democracy

The Politics of Culture: Race, Violence, and Democracy. Jung Min Choi. Karen A. Callaghan. and John W. Murphy. Westport, CT: Praeger Publishers, 1995. xii. 171 pp., notes, suggested readings, index.
Real-Time Adaptation of Mode Transition Controllers

A real-time adaptation scheme is proposed for the online customization of mode transition controllers designed offline via blending local mode controllers. It consists of the desired transition trajectory model, the active plant model, and the mode transition controller. The active plant model, which incorporates local mode information, is initially trained offline to capture the desired transition trajectory and controls. Afterward, the active plant model is adapted online via structure and parameter learning to capture the input/output relationship of the nonlinear system to be controlled. Likewise, the blending gains portion of the mode transition controller is determined offline and is adapted online via structure and parameter learning to track the desired transition trajectory. The control sensitivity matrix and the one-step-ahead predicted output of the controlled system are used to develop the desired blending gains of the mode transition. The control sensitivity matrix and the predicted output are determined from the active plant model. The proposed adaptation scheme is illustrated for a hover-to-forward-flight mode transition control of a helicopter encountering parametric changes and wind disturbances.
Sources of Generalized versus Issue-Specific Dis/Satisfaction in Service Channels of Distribution: A Review and Comparative Investigation

Abstract Service channels represent complex behavioral settings for understanding sources of dis/satisfaction between service providers and service recipients. Because of the nature of a service offering, service evaluations are frequently subjective and judgmental, making it difficult for service providers to determine precisely the sources of customer dis/satisfaction. This article empirically evaluates sources of both general and issue-specific dis/satisfactions in a health care channel setting. The effects of a series of competency-based as well as secondary predictors of dis/satisfactions are simultaneously tested for their impact on issue-specific and generalized dis/satisfaction perceptions. A meta-analytic review process is employed to isolate potential predictors of dis/satisfaction. Implications of results are discussed for both academic and practitioner communities.
Diffusion of Dioxygen in Alkanes and Cycloalkanes

The translational diffusion constant, D, of dioxygen, O2, has been measured in the odd n-alkanes n-C7H16 to n-C15H32, two branched alkanes (isooctane and squalane), and several cycloalkanes (cycloh...
Strategic Management Research in the Public Sector: A Review, Synthesis, and Future Directions

Although there is considerable literature on strategic planning and management in the public sector, there has been little effort to synthesize what has been learned concerning the extent to which these tools are used in government, how they are implemented, and the results they generate. In this article, the authors review the research on strategic planning and management in the public sector to understand what has been learned to date and what gaps in knowledge remain. In examining the 34 research articles in this area published in the major public administration journals over the past 20 years, the authors find substantial empirical testing of the impacts of environmental and institutional/organizational determinants on strategic management, but efforts to assess linkages between strategic planning processes and organizational outcomes or performance improvements are sparse. Large-N quantitative analyses and comparative case studies could improve the knowledge base in this critical area.
MinimumQ of electrically small antennas: A critical review

This paper seeks to succinctly evaluate and summarize the large body of literature on the radiation Q of electrically small antennas. The validity of the different analytic models is discussed, with key Q-dependent physical properties compared with experimental data and numerical simulations. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 28: 172–177, 2001.
What Do You Mean "Think before I Act"?: Conflict Resolution with Choices

Abstract Twenty 1st-grade students participated in an eight-week action research study. Students participated in class meetings where they discussed problem-solving solutions, particularly positive forms of conflict resolution. The “Wheel of Choice” provided the students with the choices for solutions that included 1) make an apology, 2) tell the other person to stop, 3) walk away, and 4) give an “I” message. Data was collected through 1) student pre- and post-surveys, 2) student conflict-resolution journals, 3) behavior tally sheets, 4) observational notes, and 5) teacher reflective journal. Pre- and post-surveys indicated that the students developed more positive strategies for solving conflicts. The student conflict-resolution journals demonstrated that students were able to write down positive forms of conflict resolution after thinking about the problem. Analysis of the tally sheets indicated that physical and verbal aggression decreased from the first week (22 incidents) to the eighth week (4 incide...
Helium films from two to three dimensions

Abstract Recent studies of helium films adsorbed on uniform solid surfaces reveal a rich variety of distinctive regimes. Monolayer films display several phases approximating two dimensional gases, liquids and solids as well as substrate ordered structures. Detailed theoretical models are achieving considerable quantitative success in describing and predicting properties of most of the phases. An important subset of the current studies involves the evolution from two dimensional to bulk behavior, including the onset of superfluidity.
EEG differences in ADHD-combined type during baseline and cognitive tasks

This study examines the relation between neurologic, behavioral, and performance indicators of attention-deficit-hyperactivity disorder. Twenty-three males age nine to 11 years with attention-deficit-hyperactivity disorder, including symptoms of hyperactivity, and 23 matched controls served as participants. Differences between groups were investigated using referential 19-channel quantitative electroencephalogram, behavioral rating scale data, and continuous performance test data. Results from the behavioral data were consistent with previous research. Behavioral ratings for participants with attention-deficit-hyperactivity disorder were significantly more negative than controls. Control participants performed significantly better on the continuous performance test, with fewer errors, faster reaction times, and less variability in reaction time. Electroencephalogram results indicated differences between participants with attention-deficit-hyperactivity disorder and control participants primarily in the alpha bandpass, with evidence of increased alpha in posterior regions during baseline for the group with attention-deficit-hyperactivity disorder. Additionally, participants with attention-deficit-hyperactivity disorder manifested decreased alpha in left frontal regions when reading. The results are discussed in terms of possible differences in electroencephalographic data as a function of degree of hyperactivity, as well as the impact of task specificity on the electroencephalogram.
DNA gyrase on the bacterial chromosome: DNA cleavage induced by oxolinic acid.

Treatments in vivo of Escherichia coli with oxolinic acid, a potent inhibitor of DNA gyrase and DNA synthesis, lead to DNA cleavage when extracted chromosomes are incubated with sodium dodecyl sulfate. This DNA breakage has properties similar to those obtained in vitro with DNA gyrase reaction mixtures designed to assay production of supertwists: it is oxolinic acid-dependent, sodium dodecyl sulfate-activated, and at saturating drug concentrations produces double-strand DNA cleavage with a concommitant tight association of protein and DNA. In addition, identical treatments performed on a nalA mutant strain exhibit no DNA cleavage. Thus the DNA cleavage sites probably correspond to chromosomal DNA gyrase sites. Sedimentation measurements of the DNA cleavage products indicate that there are approximately 45 DNA breaks per chromosome. This value is similar to the number of domains of supercoiling found in isolated Escherichia coli chromosomes, suggesting one gyrase site per domain. At low oxolinic acid concentrations single-strand cleavages predominate after sodium dodecyl sulfate treatment, and the inhibition of DNA synthesis parallels the number of sites that obtain a single-strand scission. Double-strand breaks arise from the accumulation of single-strand cleavages in accordance with a model where each cleavage site contains two independent drug targets, one on each DNA strand. Since the nicking-closing subunit of gyrase is the target of oxolinic acid in vitro, we suggest that each gyrase site contains two nicking-closing subunits, one on each DNA strand, and that DNA synthesis requires both to be functional.
Using the resiliency model to deliver culturally sensitive care to Chinese families.

Abstract In 1998, 4% of U.S. children were Asian/Pacific Islander; of these, 23% were Chinese. The incidence of infants with congenital heart defects (CHD) in Chinese children approximates that of Caucasian children in the United States. Parents of children with CHD are faced with caring for the children at home after surgery. Parents' roles and responsibilities expand significantly as their children return home with complex care needs. In pediatric nursing, we not only take care of the individual child but also the family as a whole. The family is the primary institution in society that preserves and transmits culture. Understanding Chinese culture and its association with health care practice helps nurses to establish culturally sensitive nursing interventions; develop appropriate discharge plans; decrease family stress; reduce future medical hospitalization costs; increase positive coping, adaptation, and family function; and improve health outcomes of the child and the family. The Resiliency Model was used to examine its applicability in caring for Chinese families in this paper. Copyright 2002, Elsevier Science (USA). All rights reserved.
population regulation, ecology, and political economy in preindustrial Iceland

Social controls on sex and marriage, rooted in the political economy, regulated population in preindustrial Iceland. Married women had high fertility, offset by low illegitimacy and a means prerequisite for marriage. The number of married householders in their childbearing years responded to changes in population pressure, adjusting fertility and moving the population toward about 50,000, a level determined by both the sub-Arctic environment and the political economy, which discouraged full use of available technology. [population regulation, population and agriculture, population and environment, population and political economy, preindustrial Iceland]
Homogeneous Catalysis with Methane. A Strategy for the Hydromethylation of Olefins Based on the Nondegenerate Exchange of Alkyl Groups and σ-Bond Metathesis at Scandium

The scandium alkyl Cp*2ScCH2CMe3 (2) was synthesized by the addition of a pentane solution of LiCH2CMe3 to Cp*2ScCl at low temperature. Compound 2 reacts with the C−H bonds of hydrocarbons including methane, benzene, and cyclopropane to yield the corresponding hydrocarbyl complex and CMe4. Kinetic studies revealed that the metalation of methane proceeds exclusively via a second-order pathway described by the rate law: rate = k[2][CH4] (k = 4.1(3) × 10-4 M-1s-1 at 26 °C). The primary inter- and intramolecular kinetic isotope effects (kH/kD = 10.2 (CH4 vs CD4) and kH/kD = 5.2(1) (CH2D2), respectively) are consistent with a linear transfer of hydrogen from methane to the neopentyl ligand in the transition state. Activation parameters indicate that the transformation involves a highly ordered transition state (ΔS‡ = −36(1) eu) and a modest enthalpic barrier (ΔH‡ = 11.4(1) kcal/mol). High selectivity toward methane activation suggested the participation of this chemistry in a catalytic hydromethylation, which...