cssi/SciSciGPT-SciSciNet huggingface dataset:
Electron attachment to the hydrogenated Watson-Crick guanine cytosine base pair (GC+H): conventional and proton-transferred structures.

The anionic species resulting from hydride addition to the Watson−Crick guanine−cytosine (GC) DNA base pair are investigated theoretically. Proton-transferred structures of GC hydride, in which proton H1 of guanine or proton H4 of cytosine migrates to the complementary base-pair side, have been studied also. All optimized geometrical structures are confirmed to be minima via vibrational frequency analyses. The lowest energy structure places the additional hydride on the C6 position of cytosine coupled with proton transfer, resulting in the closed-shell anion designated 1T (G−C(C6)). Energetically, the major groove side of the GC pair has a greater propensity toward hydride/hydrogen addition than does the minor grove side. The pairing (dissociation) energy and electron-attracting ability of each anionic structure are predicted and compared with those of the neutral GC and the hydrogenated GC base pairs. Anion 8T (G(O6)C−) is a water-extracting complex and has the largest dissociation energy. Anion 2 (GC(C4...
Tillage and dicyandiamide influence on nitrogen fertilizer immobilization, remineralization, and utilization by maize (Zea mays L.)

Both tillage and nitrification inhibitors such as dicyandiamide (DCD) have the potential to influence N availability and thus plant N uptake. A field experiment was conducted to investigate the impact of DCD and tillage (rototillage and no-tillage) on N immobilization and the subsequent impact of residual and fertilizer N on N availability to maize (Zea mays L.) 15N-labeled urea and urea-DCD were surface applied at the rate of 16 g N m-2, in either 1987 or 1988, to small plots which had been planted to maize (Zea mays L.). Soil samples were collected four times during the 1988 growing season and analyzed for the 15N and 14N components of inorganic N, organic N, and hydrolyzable (6 M HCl) amino acid N, hydrolyzable NHinf4sup+-N, and non-hydrolyzable N. Plant samples were collected three times during the 1988 growing season, and analyzed for the 15N and 14N components of total N. The total amount of NOinf3sup-percolating through the profile was less than 15 kg N ha-1 in 1987 and 1988. N uptake by maize was reduced under notillage and when the urea was treated with DCD. The tillage treatments had no effect on the uptake of N fertilizer applied in 1988 or on N immobilization. However, no-till-age reduced the uptake of residual N fertilizer. The reduced use of N fertilizer was attributed to a reduction in the actual mineralization rates of immobilized residual N. DCD reduced the uptake of N fertilizer applied in 1988. The reduced uptake was attributed to increased N immobilization or to organic matter fixation.
Pragmatic agency in technology standards setting: The case of Ethernet

Abstract Technology standards refer to the specifications that provide users and vendors with a common platform and ensure compatibility between components of a technological system. These technical “rules of the game” are being increasingly set in standards development organizations (SDOs). In this paper, I ask the question: how do actors operating in these venues address the challenges posed by the anticipatory and collective nature of the specifications they are establishing? Through an in-depth analytic narrative of the Ethernet LAN (local area network) standard, I indicate how actors engage in an ongoing process of extension generation, ratification and incorporation. In imagining alterations to a specification, approving timely modifications and crafting an identity for a rule even as it changes, they manifest “pragmatic agency” in these contexts. In exercising such agency, SDO's substantially increase the functionality of an existing standard as well as boost its long-term competitive viability.
Studies in the synthesis of C-ring bridged morphinans 3—13C NMR analysis of some simple and complex bicyclooctane derivatives†

The 13C NMR spectra of eight novel derivatives of bicyclo[2.2.2]- and -[3.2.1]octane have been recorded and analysed. These compounds were isolated and characterized as intermediates in the synthesis of a unique derivative of 1,2,3,3a,11b,11c-hexahydroaporphine. Carbon chemical shift assignments of the molecules under investigation were based on 13C NMR theory including splitting patterns, differences in chemical shift values of carbons α and β to amino nitrogens in their protonated and non-protonated forms, and through the anticipated shielding effects of γ-syn and γ-anti heteroatoms. This latter method of analysis was particularly useful in assigning the chemical shift values of carbons in the bicyclooctane region of the simpler molecules.
The Behavioral and Emotional Rating Scale-2 (BERS-2): Providing a Comprehensive Approach to Strength-Based Assessment

Identification of strengths is considered an important part of school psychological practice. However, few instruments are available to school psychologists that allow for systematic and comprehensive evaluation of a student’s emotional and behavioral strengths. School psychologists must be provided with psychometrically sound instruments that will measure students’ emotional and behavioral skills and competencies. The Behavioral and Emotional Ratings Scale (BERS) was developed in response to the need for a valid and reliable instrument for assessing and evaluating strengths, but it became evident that the single instrument was not comprehensive. The BERS has now been restandardized to create two additional scales: a parent rating scale and a youth self-report scale. The Behavioral and Emotional Rating Scale-2nd Edition (BERS-2) scales now provide school psychologists with a comprehensive set of standardized instruments to assess children’s emotional and behavioral strengths. The purpose of this article is threefold: (a) to provide a brief overview of strength-based assessment in school psychological practice, (b) to discuss the development of the BERS-2, and (c) to discuss the use of the BERS-2 in school psychological practice.
The effects of the electoral calendar on terrorist attacks

The goal of this paper is to study the linkages between the timing of terrorist events and elections. As strategic actors terrorists may respond to electoral environments by altering the frequency of their attacks around election times. Focusing on democracies, we examine variations in transnational and domestic terrorist incidents before elections over a 40 year span. We find distinct pre-electoral changes in the incidence of terrorist events. In the ITERATE data set, where only transnational terrorist events are included, terrorist activities decline in election months, while in the partitioned GTD data set, where only domestic terrorist events are kept, terrorist activities rise in election months. The findings suggest electoral calendars can dissuade and attract terrorist threats, depending on the origin of the threat, but these effects occur only very close to election time.
An image theory of instrumental conditioning.

According to theories of classical conditioning and images, an image of the goal for an instrumentally conditioned response occurs by way of classically conditioned associations between the stimuli of the learning situation and the stimuli produced by the instrumentally conditioned response and between these response-produced stimuli and the goal. Also, the animal is viewed as behaving in order to change the vividness of the image of the reinforcer, associated with a change in the “reinforcing effect” of the image of the reinforcer, and does so by producing successively closer approximations to the stimuli produced by the instrumentally conditioned response via a feedback process, this response thereby eventuating. Image approaches to some instrumental conditioning results and some theories of instrumental conditioning are also discussed.
What's the Control in Studies Measuring the Effect of Computer-Aided Detection (CAD) on Observer Performance?

Rationale and Objectives The goal of many multiple-observer computer-aided detection (CADe) studies is to estimate the change in observers' diagnostic performance with CADe from their unaided performance. A key issue in these studies is the method for estimating the observers' unaided performance. The crossover design is considered the most valid. The sequential design takes less time and is less expensive but may be biased. We conducted a study to investigate the differences between these two designs. Materials and Methods Data from two large CADe studies using both types of unaided reads were analyzed. The first study involved three radiologists examining the chest x-rays of 200 patients for lung nodules. The second study involved 19 observers interpreting the computed tomography colonography images of 100 patients for polyps. Observers' sensitivity, specificity, and receiver operating characteristic areas were estimated while unaided in both designs and compared to their accuracy with CADe. Bias, inter-observer variability, and correlations between unaided and aided results were assessed. Results Observers tend to perform better while unaided in the sequential design than while unaided in the crossover design, but the differences are small. The inter-observer variability is larger in the sequential design. The correlations between unaided and aided results are larger in the sequential design. 95% CIs for the change with CADe are narrower with the sequential design. Conclusion The estimated effect of CADe on observer performance is similar regardless of the study design. Use of the sequential design may save investigators time and resources.
Achromaticity vs. Isochronicity

An achromatic system is one where the transfer matrix elements for the transverse coordinates do not depend on momentum. An isochronous system is one where the transit time of a trajectory through the system does not depend on the initial coordinates. It is well known that a first-order achromatic system is also isochronous, except for pure momentum dependence. The converse is also true. This result is entended to higher orders. Conditions are found so that for a system whose chromatic terms all vanish up to a certain order the transit time will be independent of the transverse coordinates up the same order. Under the same conditions, the converse will also be true.
Statistical estimation of the intrinsic dimensionality of data collections

A realization f i (·) from a class F (·) can be represented as a point in a metric space and the locus of all points belonging to F (·) lie on a surface in this space. The intrinsic dimensionality of F (·), defined as the least number of parameters needed to identify any f i (·) belonging to F (·), is equal to the topological dimensionality of this surface. Given a sample set of realizations f i (·) from F (·), a statistical method is presented for estimating the intrinsic dimensionality of F(·).
Distribution of α-aminoisobutyric-C14 acid in rats deficient in thiamine, pantothenate, fatty acids, or potassium.

A nutritional deficiency of fatty acids in young rats resulted in a marked elevation of the steady-state serum level of an injected dose of ol-aminoisclbutyric acid, and in a decrease in the transport of this model amino acid into skeletal muscle, heart, and intestine. The liver level was greatly increased. Adrenalectomy of the deficient rats reduced the uptake in both liver and kidney. These changes were similar to those reported earlier for rats deficient in vitamin Be. No consistent pattern of change in distribution of the model amino acid was found in rats deficient in thiamine, pantothenate, or potassium. The extremely high liver levels of the amino acid seen in thiamine-deficient rats could be returned toward normal by removing the adrenal glands. All of the changes found in the K+-deficient animals were brought essentially to normal by bilateral adrenalectomy. No consistent relationship was found between the uptake of the amino acid and the Kf level in the heart or skeletal muscle of the rats in the control, K+-deficient, and the Kc-deficientadrenalectomized groups. The accumulation of amino acids by taken from vitamin Be-deficient mice (l), Ehrlich mouse ascites tumor cells in vitro and for normal uptake of the model amino has been found to be increased by a number acid, a-aminoisobutyric acid, by all tissues of unrelated biological agents, including examined in rats in vivo (5; cf. Ref. (6) for a pyridoxal and pyridoxal phosphate (l), more detailed discussion of the relations e&radio1 disulfate and estrone sulfate (2), between vitamin Be and amino acid transand several auxins (1). In addition, the port). Estradiol-170, on the other hand, accumulation is dependent upon the normal alters the distribution of model amino acids K+ and Na+ content of the tumor cells (3). in vivo only in those tissues that are suscepti
An Evaluation of an HIV Testing Program in the Jail Setting: Results and Recommendations

Prison and jail inmates tend to be involved disproportionately in behavior that places them at risk for HIV transmission. The state of New Jersey, and its urban areas in particular, has a high rate of African American residents living with HIV or AIDS. In an effort to reach several urban areas where individuals have not yet been diagnosed, a southern New Jersey county jail has begun offering free rapid HIV tests on a voluntary basis. Results indicate that correctional facilities were among the most common places for inmates to receive testing and that those tested were involved in numerous high-risk sexual and/or drug activities. Recommendations for future testing and education programs are provided.
Transit and Carpool Commuting and Household Vehicle Trip Making: Panel Data Analysis

Most of the evaluation of commute trip reduction programs centers on the effect on reducing driveway trips at the work site. Little has been done to explore the effects of such programs on overall trip making. This work is meant to help understand this relationship by determining the association between transit and carpool commuting and overall household vehicle trip making. Household activity models have indicated that an individual's travel decisions influence (and are influenced by) the decisions of other household members. It is thus postulated that one household member's choice of transit or carpool for the morning trip to work will affect the mode choices of the other household members. In addition, the choice of mode to work will affect the individual's mode choices for trips other than the morning trip to work. The analysis uses the first four waves of the Puget Sound Transportation Panel survey to construct linear econometric longitudinal trip generation models (random effects models). The results of the modeling indicate that one household member's mode choice to work does affect overall household vehicle travel. Compared with driving alone to work, if one household member chooses transit to work, overall household vehicle trips are reduced (on average). Carpooling by one household member is associated with little change in overall household travel, with average daily household vehicle trips ranging between one trip fewer and one trip greater than households where each driver in the household drives to work in a separate, single-occupant vehicle. The analysis strengthens the associations to imply causal links. The model results suggest that an improved understanding of interactions among household members is necessary to define strategies in support of commute trip reduction policies to better meet air quality and congestion-management goals.
Contact problem for elastic spheres: Applicability of the Hertz theory to non-small contact areas

The problem of normal contact of two identical elastic spheres is considered. The corresponding mixed boundary-value problem is formulated at the surface of the sphere, thereby relaxing the assumption of the Hertz theory about small size of the contact area compared to the sizes of the contacting bodies. A general solution in the form of Legendre series expansions is used to reduce the problem to dual series equations, and, subsequently, to a Fredholm integral equation of the second kind. Analysis of the contact stress and surface displacements of the sphere is carried out. Comparison of the results with the Hertz theory shows that the latter predicts contact stresses with high accuracy even for relatively large contact areas.
Developmental exposure to diethylstilbestrol alters uterine gene expression that may be associated with uterine neoplasia later in life.

Previously, we described a mouse model where the well-known reproductive carcinogen with estrogenic activity, diethylstilbestrol (DES), caused uterine adenocarcinoma following neonatal treatment. Tumor incidence was dose-dependent reaching >90% by 18 mo following neonatal treatment with 1000 μg/kg/d of DES. These tumors followed the initiation/promotion model of hormonal carcinogenesis with developmental exposure as initiator, and exposure to ovarian hormones at puberty as the promoter. To identify molecular pathways involved in DES-initiation events, uterine gene expression profiles were examined in prepubertal mice exposed to DES (1, 10, or 1000 μg/kg/d) on days 1–5 and compared to controls. Of more than 20 000 transcripts, approximately 3% were differentially expressed in at least one DES treatment group compared to controls; some transcripts demonstrated dose–responsiveness. Assessment of gene ontology annotation revealed alterations in genes associated with cell growth, differentiation, and adhesion. When expression profiles were compared to published studies of uteri from 5-d-old DES-treated mice, or adult mice treated with 17β estradiol, similarities were seen suggesting persistent differential expression of estrogen responsive genes following developmental DES exposure. Moreover, several altered genes were identified in human uterine adenocarcinomas. Four altered genes [lactotransferrin (Ltf), transforming growth factor beta inducible (Tgfb1), cyclin D1 (Ccnd1), and secreted frizzledrelated protein 4 (Sfrp4)], selected for real-time RT-PCR analysis, correlated well with the directionality of the microarray data. These data suggested altered gene expression profiles observed 2 wk after treatment ceased, were established at the time of developmental exposure and maybe related to the initiation events resulting in carcinogenesis.
Radiation Tolerance of Bubble-Domain Materials and Devices

Following a brief outline of magnetic bubble domain technology and possible radiation effects, the results of radiation effects experiments are presented. Permanent damage experiments on materials consisted of characterizing samples of Y3 (FeGa)5O12, Er3(FeGa)5O12, and (YGdTm)3 (FeGa)5O12 films before and after exposure to neutrons from a TRIGA reactor and to Co60 gammas. Parameter measurements included saturation magnetization, wall energy, defect density, wall mobility, coercivity, and saturation velocity. No significant changes in these parameters were observed after 1015 n/cm2 (1 MeV equivalent) and 5 × 107 rads. Permanent damage experiments on devices included measurements of propagation and annihilation margins, and domain sensor output (for shift registers) before and after exposure to reactor neutrons and Co60 gammas. Again no significant change was found after 4 × 1014 n/cm2 (1 MeV equivalent) and 5 × 107 rads for devices with hard-bubble suppression. Magnetoresistive parameters of a thin, permalloy domainsensor film were also unchanged after 1015 n/cm2 and 5 × 107 rads. Information stored in a shift register was read electrically immediately before and after exposure to a 30 ns pulse of 1.5 MeV electrons with a dose of 3 × 104 rads(Si) and found unchanged. A similar experiment, using optical determination of the stored information, indicated no change after a 1.7 × 105 rad pulse.
MyoD-positive epiblast cells regulate skeletal muscle differentiation in the embryo

MyoD mRNA is expressed in a subpopulation of cells within the embryonic epiblast. Most of these cells are incorporated into somites and synthesize Noggin. Ablation of MyoD-positive cells in the epiblast subsequently results in the herniation of organs through the ventral body wall, a decrease in the expression of Noggin, MyoD, Myf5, and myosin in the somites and limbs, and an increase in Pax-3–positive myogenic precursors. The addition of Noggin lateral to the somites compensates for the loss of MyoD-positive epiblast cells. Skeletal muscle stem cells that arise in the epiblast are utilized in the somites to promote muscle differentiation by serving as a source of Noggin.
CHARACTERISTICS OF RIBOSOMES ISOLATED FROM ROOTS OF ZEA MAYS.

Ribosomes were isolated from root tips of corn (Zea mays) and their properties studied. Five ribosomal components (40 S, 60 S, 80 S, 120 S, and 150 S), with the 80-S component predominating, were present in the cytoplasmic extract. Sedimentation coefficients at infinite dilution were determined for all except the 150-S component. Purified ribosomes contained 43% RNA which was characterized by a high guanine and relatively high cytosine content. The 80-S component dissociated into 60-S and 40-S particles when pH of the medium was increased from 6.5 to 8.0 or higher. Magnesium (0.5–2 mM) prevented the dissociation. In marked contrast to the 70-S ribosome of Escherichia coli, the 80-S ribosome of corn did not require added magnesium to maintain its integrity in a solution of nearly neutral pH and low ionic strength. In fact, 5 mM magnesium in such a solution caused the association of corn ribosomes into large random aggregates. Ribosomes of different organisms differ in the level of magnesium required to preserve their 70–80-S component and may be divided accordingly into three broad groups exemplified by E. coli, yeast, and corn ribosomes.
The biomedical ethics ontology proposal: excellent aims, questionable methods.

Koepsell et al. (2009) Describe a world much better than ours, a world with electronic and universal IRB application forms and consent templates, automated decision-trees, and broad sharing of IRB data. We should work to make that world a reality. However, it is unclear that a biomedical ethics ontology (BMEO) is the best path toward this goal for reasons that applied ontologists have identified elsewhere. I will focus on only two features of any applied ontology that are problematic for the development of a useful BMEO: (1) an ontology is a description of a domain of reality; and (2) the description is subject to ongoing revision as it is developed through open- source processes within a wiki community. To summarize, I argue that a BMEO needs to address two kinds of entities—ethical concepts and regulatory definitions—and it is ill suited to both. Ethical concepts within pluralistic societies are social constructs—not a priori concepts or biological natural kinds—and accordingly the prospects of generating intuitive (and thus easy-to-use) definitions that enjoy broad acceptance across cultures and institutional settings are slim. Regulatory definitions are fiats and ought to be adopted verbatim to enable compliance, but in such cases we do not need the assistance of ontologists, and their modes of working (constant revision within open wiki-based communities) might even be counterproductive. In making these arguments, I draw from writings of leading applied ontologists and Koepsell et al.’s own proof of concept.
Uterovaginal sperm-host gland homogenates and respiratory rate of cock spermatozoa.

Abstract 1. 1. Oxygen utilization rates were determined for semen samples incubated in phosphate buffer diluent, diluent with added magnum homogenates and diluent with added uterovaginal sperm-host gland homogenates. 2. 2. Both homogenates caused significant increases in spermatozoal oxygen utilization rates. 3. 3. In addition, the sperm-host gland homogenates led to significantly greater spermatozoal oxygen utilization rates than did the magnum homogenates. 4. 4. No differences in spermatozoal survival rates, motility estimates and hydrogen ion increases were detected. 5. 5. Spermatozoa when residing within the sperm-host glands are presumably stimulated in a similar manner.
Adaptation of amplitude structure of songs to propagation in field habitat in song sparrows

We examined the influence of two habitats, old field and small islands on a river, on the propagation of amplitude and frequency characteristics of song sparrow songs. At 27 m from the source, songs originally recorded in the field degraded significantly less there than over water in the river. At that distance, songs recorded on the river also degraded less in the field than over water, but the differences were not significant. At 54 m from the source, songs recorded at both sites also tended to degrade more on the river than in the field, but the differences were not significant. Songs from the two habitats differed significantly in the total number of amplitude peaks in a song, in song duration, in maximum frequency, and frequency range. They did not differ significantly in the fraction of peaks in the upper amplitude range, and in the width of the amplitude range. The results suggest that, in fields, a more typical habitat, songs are locally adapted to communication at about 30 m but poorly so at 60 m from the source. We suggest that this is related to the territory size of birds in the field. The results are discussed in relation to the ranging hypothesis (Morton 1982) that predicts that the least degraded song types would be selected for, and that listeners use degradation to estimate their distance from singers.
Nonlinear mechanics of MEMS plates with a total Lagrangian approach

The subject of this paper is a fully Lagrangian approach for coupled (mechanical deformations caused by applied electric fields) analysis of Micro-Electro-Mechanical (MEM) plates. The analysis is carried out by employing the two-dimensional (2-D) Finite Element Method (FEM) to analyze mechanical deformations in the plate and the three-dimensional (3-D) Boundary Element Method (BEM) to obtain the electric field (and then tractions on the plate surface) in the region exterior to the plate. Self-consistent solutions to the coupled problem are obtained by the relaxation method. Such simulations, especially their dynamic version, has many potential applications such as to understand and design synthetic microjets.
Simultaneous shifts in reward magnitude and level of food deprivation

Rats were employed in a 2 by 2 factorial design varying deprivation level (11 vs 20 g of food per day) and reward magnitude (1 vs 10 pellets) in Phase 1. In Phase 2, all groups were run to 10 pellets under low deprivation. Both Phase 1 deprivation level and Phase 1 reward magnitude exerted a significant effect on running speed in Phase 2. More importantly, the interaction of these two variables was not significant. The effect of Phase 1 reward magnitude decreased over the rewarded trials of Phase 2, while the effect of Phase 1 deprivation level did not. However, in a subsequent extinction phase, the effects of Phase 1 deprivation level disappeared.
Environmental Influences on Early Development and Year-Class Strength of Northern Pike in Lakes Oahe and Sharpe, South Dakota

Abstract Survival of artificially-fertilized ova and larvae of northern pike, Esox lucius, was estimated from embryos held in natural spawning areas in Lake Oahe and Lake Sharpe, two main stem Missouri River reservoirs. Mortalities approaching 100% during early embryonic development were associated with sudden drops in water temperature below 10 C or prolonged temperatures near 5 C. Silt deposition of 1.0 mm per day was associated with mortality of 97% or above. Following hatching available food appeared to be a more important factor in survival than temperature change or silt deposition. Estimates of year-class strength of northern pike in the two reservoirs suggest that large year classes were associated with stable to rising water level and temperature, flooded vegetation, and calm weather during the spawning season. Small year classes have been associated with abrupt water temperature fluctuations, dropping water level, and high silt deposits.
Measurement accuracy enhancements for wideband modulated signals

Time-domain waveform measurements of wideband modulated signals, although attractive for communication systems modeling applications, have until now lacked the required accuracy for quantitative analysis. New developments described here enhance the accuracy of these measurements, enabling their application to communication system characterization and modeling. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 32–39, 2003.
Selection and recognition of landmarks using terrain spatiograms

A team of robots working to explore and map an area may need to share information about landmarks so as to register their local maps and to plan effective exploration strategies. In previous papers we have introduced a combined image and spatial representation for landmarks: terrain spatiograms. We have shown that for manually selected views, terrain spatiograms provide an effective, shared representation for occlusion filtering and for combination of multiple views. In this paper, we present a landmark saliency architecture (LSA) that will automatically select candidate landmarks given some preference settings. Using a dataset of 21 outdoor stereo images generated by LSA, we show that the terrain spatiogram representation reliably recognizes automatically selected landmarks. The terrain spatiogram results are shown to improve on two purely appearance based approaches: template matching and image histogram matching.
Nylon surface modification. Part 1. Targeting the amide groups for selective introduction of reactive functionalities

Abstract Nylon is a widely used synthetic polymer because it has a combination of strength, flexibility, toughness, and abrasion resistance. For a variety of applications, however, it is necessary to impart desired surface properties by introducing specific functional groups in specific locations and densities. Several chemical modification methods were developed for the introduction of functional groups to nylon surfaces using amide-selective reactions without cleaving the polymer chains. Activation of amides by reaction with potassium tert-butoxide (t-BuOK) facilitates the N-alkylation of surface amides. When 2-bromoethylamine hydrobromide (BEA–HBr) was employed as an alkylating agent, surfaces with a mixture of primary/secondary/tertiary amine groups were obtained. Alkylation with (3-glycidoxypropyl)triethoxysilane (GPTES) was utilized to prepare surfaces with silica-like reactivity. Chemical reduction with borane–THF complex (BH3-THF) results in a 69% conversion of surface amide groups to the corresponding secondary amines. A kinetic study of this reaction for different types of nylon films revealed that the yield was dependent on the segmental mobility of the polymer. These surfaces are useful substrates for the fabrication of nylon-supported composite films.
Serum leptin and weight gain over 8 years in African American and Caucasian young adults.

FOLSOM, AARON R., MICHAEL D. JENSEN, DAVID R. JACOBS, JR., JOAN E. HILNER, ALBERT W. TSAI, AND PAMELA J. SCHREINER. Serum leptin and weight gain over 8 years in African American and Caucasian young adults. Obes Res. 1999;7:1–8. Objective: There is considerable interest in how to prevent weight gain in adulthood. Leptin, a peptide hormone expressed in adipose tissue, is believed to signal the central nervous system about the level of body fat stores, and thereby may control appetite. Little information exists on whether the serum leptin concentration influences long-term weight changes in the free-living population. Research Methods and Procedures: From an ongoing cohort study of young African American and white adults, we selected a sample of participants (n=492), stratified on sex, race, and weight changes over 8 years. Serum leptin was measured on stored specimens using a radioimmunoassay. Weight change was modeled in relation to baseline leptin concentrations. Results: Cross-sectionally, leptin concentration was associated positively with body mass index, negatively with physical activity level, and was higher in women than men. These variables explained 72% of the variance in serum leptin. Over the 8 years, the sample gained an average of 7.8 kg (standard deviation = 10.8). There was no evidence that 8-year weight change was associated with initial leptin concentration: 8-year weight change was only 0.5 kg less (95% confidence interval = −1.8 to 0.8, p = 0.47) per each 10 ng/ mL increment (approximately one standard deviation) of baseline leptin. In contrast, leptin change correlated highly (r = 0.62) with weight change. Discussion: Our data corroborate evidence that adiposity determines leptin levels but do not support the hypothesis that leptin deficiency plays an important role in obesity in the general population.
Regulation and the market for corporate control: Hostile tender offers for electric and gas utilities

We document that regulation significantly constrains takeover activity. Of the twenty-one hostile offers for utilities between 1960 and 1990, only one was successful. In spite of this low rate of completion, announcement period returns to target utilities are positive and significant, although substantially smaller than average returns to nonregulated targets. We examine post-offer events and find that control-market effects are not entirely eliminated. One-third of hostile offers are followed by additional bids, control changes and/or divestitures. The regulatory and political environment changed during the period of this study and the frequency of hostile offers increased. Utility regulation, however, remains a substantial impediment to the completion of hostile takeovers.
Evaluation of an automatic cardiac activation detector for bipolar electrograms

The identification of local activation events in bipolar cardiac electrograms, the first step of isochronal map construction, is a time-consuming and difficult process. Owing to the variability among bipolar activation complexes and the lack of practical knowledge concerning the relationship of the bipolar waveform to action potential characteristics, a set of empirical rules to guide the assignment of local activation times have been adopted. A computer program, called AP, has been designed, which implements these rules in the form of a syntactic analyser. Canine epicardial recordings were used to evaluate AP by comparing local activation times, assigned by AP, with times assigned independently by three investigators. The Hermes-Cox model for detector evaluation and a bootstrap statistical method were used in conjunction with ROC analysis to evaluate the ability of AP to detect events. Analysis of discrepancies among investigator-assigned times showed that the reliabilities of AP event detection and AP-assigned times were comparable to those of the investigators. The methods used in system design and evaluation are applicable to a broad range of problems in the detection and localisation of waveform components.
Respiratory and cardiac effects on venous return.

Abstract Cardiac activity and respiration markedly alter the venous flow patterns in the major thoracic systemic veins. Cardiac activity ( vis a fronte ) is associated with two periods of increased and two periods of decreased venous flow, corresponding to changes in atrial pressure. Respiratory activity predominates in most instances, however, producing a large increase in venous return during inspiration. Alterations in respiratory activity produced by procedures such as positive pressure ventilation, airway occlusion, whining, etc., cause much greater changes in venous return and cardiac output than do changes in posture or passive tilting. Excitement, exercise, and pentobarbital anesthesia can produce marked changes in venous return. Pentobarbital can increase the percentage of blood returning to the right heart via the inferior vena cava. Gravity apparently is relatively unimportant in returning blood to the heart.
The effect of potassium diethyldithiophosphate on the electrochemical properties of platinum, copper and copper sulfide in aqueous solutions

Summary Linear sweep voltammetry has been used to study the electrochemical properties of platinum, copper and copper sulfide electrodes in the absence and in the presence of potassium diethyldithiophosphate. The influence of several variables, namely, sweep rate, solution pH, dithiophosphate concentration, etc. has been studied. Oxidation-reduction reactions at platinum, copper and copper sulfide electrodes are postulated to explain the observations. In the absence of any dithiophosphate in solution, the initial oxidation reaction is probably the discharge of hydroxyl ions. Dithiophosphate ions inhibit the oxidation reaction. Under suitable conditions, bis(diethoxythiophosphoryl)disulfide forms at platinum, whereas cuprous and cupric dithiophosphates form at copper and copper sulfide. The oxidation products can be reduced at the respective electrodes, however, the reactions are generally irreversible.
Evaluation of model-based processing algorithms for averaged transmitral spectral Doppler images

In an effort to characterize more fully diastolic function using Doppler echocardiography, we have previously developed an automated method of model-based image processing for spectral Doppler images of transmitral blood flow. In this method, maximum velocity envelopes (MVEs) extracted from individual Doppler images are aligned and averaged over several cardiac cycles. The averaged waveform is fit by the solution of a kinematic model of diastolic filling. The results are estimates of the model parameters. As expected, the mean and standard deviation of the model parameter estimates depend on many factors such as noise, the number of cardiac cycles averaged, beat-to-beat variation, waveform shape, observation time and the processing methods used, among others. A comprehensive evaluation of these effects has not been performed to date. A simulation was developed to evaluate the performance of three automated processing methods and to measure the influence of noise, beat-to-beat variation and observation time on the model parameter estimates. The simulation's design and a description and analysis of the three automated processing methods are presented. Of the three methods evaluated, using the inflection point in the acceleration portion of the velocity contour as the first data point to be fit was found to be the most robust method for processing averaged E-wave MVE waveforms. Using this method under nominal conditions, the average bias was measured to be < 3% for each of the model parameters. As expected, the biases and standard deviations of the estimates increased as a result of increased noise levels, increased beat-to-beat variation and decreased observation time. Another important finding was that the effects of noise, beat-to-beat variation and waveform observation time on the parameter estimates are dependent on the location in model parameter space.
TNF-α Receptor Knockout Mice Are Protected from the Fibroproliferative Effects of Inhaled Asbestos Fibers

We have demonstrated that C57BL/6–129 hybrid mice with genes for both the 55kd and 75kd receptors for TNF-α knocked out (TNF-αRKO) fail to develop fibroproliferative lesions after asbestos exposure. There is good evidence that TNF-α plays a major role in mediating interstitial pulmonary fibrosis. Our findings support this view and we present here new data obtained by in situ hybridization showing that expression of the genes coding for transforming growth factor α (TGF-α) and platelet-derived growth factor A-chain (PDGF-A) is reduced in the TNF-αRKO mice compared with control animals. In accordance with this observation, data on bromodeoxyuridine (BrdU) incorporation in the lungs of the TNF-αRKO mice show no increases over unexposed control animals. In contrast, wild-type control mice exposed to asbestos exhibit 15- to 20-fold increases in BrdU uptake and consequently develop fibrogenic lesions. Even though the levels of TNF-α gene expression and protein production were increased in the asbestos-exposed TNF-αRKO mice, the lack of receptor signaling protected the mice from developing fibroproliferative lesions. We agree with the view that TNF-α is essential for the development of interstitial pulmonary fibrosis and postulate that TNF-α mediates its effects through activation of other growth factors such as PDGF and TGF-α that control cell growth and matrix production.
Efficiency of static and computer adaptive short forms compared to full-length measures of depressive symptoms

Purpose Short-form patient-reported outcome measures are popular because they minimize patient burden. We assessed the efficiency of static short forms and computer adaptive testing (CAT) using data from the Patient-Reported Outcomes Measurement Information System (PROMIS) project.
Designing Low-Pressure Turbine Blades With Integrated Flow Control

A low pressure turbine blade was designed to produce a 17% increase in blade loading over an industry-standard airfoil using integrated flow control to prevent separation. The design was accomplished using two-dimensional CFD predictions of blade performance coupled with insight gleaned from recently published work in transition modeling and from previous experiments with flow control using vortex generator jets (VGJs). In order to mitigate the Reynolds number lapse in efficiency associated with LPT airfoils, a mid-loaded blade was selected. Also, separation predictions from the computations were used to guide the placement of control actuators on the blade suction surface. Three blades were fabricated using the new design and installed in a two-passage linear cascade facility. Flow velocity and surface pressure measurements taken without activating the VGJs indicate a large separation bubble centered at 68% axial chord on the suction surface. The size of the separation and its growth with decreasing Reynolds number agree well with CFD predictions. The separation bubble reattaches to the blade over a wide range of inlet Reynolds numbers from 150,000 down to below 20,000. This represents a marked improvement in separation resistance compared to the original blade profile which separates without reattachment below a Reynolds number of 40,000. This enhanced performance is achieved by increasing the blade spacing while simultaneously adjusting the blade shape to make it less aft-loaded but with a higher peak cp . This reduces the severity of the adverse pressure gradient in the uncovered portion of the modified blade passage. With the use of pulsed VGJs, the design blade loading was achieved while providing attached flow over the entire range of Re. Detailed phase-locked flow measurements using three-component PIV show the trajectory of the jet and its interaction with the unsteady separation bubble. Results illustrate the importance of integrating flow control into the turbine blade design process and the potential for enhanced turbine performance.Copyright © 2005 by ASME
The Data Acquisition System for the HHIRF Spin Spectrometer

The Spin Spectrometer at the Holifield Heavy Ion Research Facility (HHIRF) is a multidetector ..gamma..-ray spectrometer consisting of 72 separate NaI detector elements closely packed in a 4..pi.. geometry. The basic apparatus was constructed at Washington University and has been installed and implemented at the HHIRF at Oak Ridge National Laboratory. The spectrometer was designed especially for the investigation of the mechanisms of heavy-ion induced nuclear reactions and of the structure of nuclei with high angular momentum. The data acquisition system is described. (WHK)
Abrupt change in magma generation processes across the Central American arc in southeastern Guatemala: flux-dominated melting near the base of the wedge to decompression melting near the top of the wedge

Lavas erupted behind the volcanic front in southeastern Guatemala have many important distinctions from lavas erupted on the volcanic front. These include: generally higher MgO, Nb, Sr, TiO2, and rare earth element concentrations; higher La/Yb and Nb/Y ratios; and lower Ba/La, La/Nb, Ba/Zr and Zr/Nb ratios. These major and trace element distinctions are caused by reduced fractionation during ascent and storage in the crust, lower degrees of melting in the source, and greatly reduced contributions from the subducted Cocos plate in the source. In addition, because all of these important distinctions are even borne in lavas erupted within 20 km of the front, there is little apparent petrogenetic continuity between front and behind-the-front magmas. What little geochemical continuity exists is in radiogenic isotopes: 143Nd/144Nd falls across the arc, Pb isotopic ratios (except 206Pb/204Pb) rise across the arc, and 87Sr/86Sr rise across the arc after an initial discontinuity within 20 km of the front. These continuous across-arc changes in radiogenic isotopes are caused by increased contamination with older, more isotopically disparate rocks, away from the front. Once the effects of crustal contamination are removed, the remaining isotopic variability behind the front is non-systematic and reflects the inherent isotopic heterogeneity of the source, the mantle wedge. Geochemical disconnection in southeastern Guatemala suggests that behind-the-front magmas are produced by decompression melting near the top of the wedge, not by flux-dominated melting near the base of the wedge.
The physiology and brain mechanisms of feeding

This article is designed as an introduction to the major theoretical models in the field of regulation of eating behavior, and a selective review of relevant neurobiological data. We first critically consider the paradigm of homeostasis as it relates to body energy content, and argue that additional theoretical constructs will be needed to account for the complexity of eating behavior in both nonhumans and humans. We then summarize some of the methods available to the neuroscientist in this area, and address some of their limitations. We review treatments and potential mechanisms that increase food intake, including deprivation, antimetabolites, norepinephrine, and several peptides including neuropeptide Y. We next review treatments that decrease food intake, including a variety of humoral, gastrointestinal, and pancreatic factors, as well as examine central pathways of satiety. This includes a discussion of leptin and other potential anorectic agents. We conclude with a discussion of human obesity and anorexias, and prospects for pharmacotherapy of eating disorders. We emphasize throughout that most regions of the human brain probably make some contribution to feeding behavior, and so a focus on any one area of transmitter/hormone is an unrealistic approach both in basic and applied areas.
How much esmolol was administered

To the Editor, In their recent article, Lopez-Alvarez et al. compared an esmolol infusion vs ketamine-remifentanil combination for their effects on postoperative analgesia. I read the article with great interest, but I am confused about the esmolol dosing regimen that is reported. In the methods section, the dose of esmolol was reported as 0.5 mg kg iv bolus, followed by a continuous infusion titrated from 5-15 lg kg min to maintain the patient’s mean arterial pressure and heart rate within 20% of respective baseline values. Reviewing Table 1 of the article, the mean total esmolol dose administered was 5.2 mg kg, whereas the mean duration of anesthesia was 64 min. Mathematically, 4.7 mg kg of the mean total dose had to be given as an infusion (since the bolus dose was 0.5 mg kg iv in all patients). Therefore, even had the patient received the maximum stated dose of esmolol (i.e., 15 lg kg min) for the entire duration of anesthesia, this would have resulted in a mean total dose of esmolol of only 0.96 mg kg. Adding the bolus dose would then bring the total dose to 1.46 mg kg. Accordingly, there appears to be a considerable discrepancy between the esmolol dosing according to the methods (1.46 mg kg, calculated for mean anesthetic duration assuming the maximum infusion rate) and the results (5.2 mg kg). I would be curious to hear from the authors as to whether they used a much bigger dose range of esmolol or whether they miscalculated the total esmolol dose reported in Table 1 of their article.