cssi/SciSciGPT-SciSciNet huggingface dataset:
A relationship between stochastic matrices and eigenvalues of products

Abstract Let { B 1 ,…, B n } be a set of n rank one n × n row stochastic matrices. The next two statements are equivalent: (1) If A is an n × n nonnegative matrix, then 1 is an eigenvalue of B k A for each k =1,…, n if and only if A is row stochastic. (2) The n × n row stochastic matrix S whose k th row is a row of B k for k =1,…, n is nonsingular. For any set { B 1 , B 2 ,…, B p } of fewer than n row stochastic matrices of order n × n and of any rank, there exists a nonnegative n × n matrix A which is not row stochastic such that 1 is eigenvalue of every B k A , k =1,…, p .
Anatoxin-a(s), an anticholinesterase from the cyanobacterium Anabaena flos-aquae NRC-525-17.

Anatoxin a(s) [antx-a(s)] given intraperitoneally to Sprague-Dawley rats at different doses (0.1-1.0 mg/kg) caused signs of severe cholinergic overstimulation. Assays of rat blood acetylcholinesterase (AChE) revealed a dose-dependent inhibition. The in vitro inhibition of electric eel acetylcholinesterase (AChE, E.C. 3.1.1.7) and horse serum butyrylcholinesterase (BUChE, E.C. 3.1.1.8) by antx-a(s) was time- and concentration-dependent. The inhibition of electric eel AChE follows first order kinetics, indicative of irreversible inhibition. The irreversibility of electric eel AChE inhibition was confirmed by a plot of Vmax versus total enzyme concentration [ET]. The kinetics of inhibition of cholinesterase by antx-a(s) supports the previous pharmacological findings that antx-a(s) is an anticholinesterase and that signs of intoxication by it are primarily due to cholinesterase inhibition.
Prolonged mild hypoxia alters fetal sheep electrocorticogram activity.

To assess the effects of prolonged mild hypoxemia on fetal brain electrocorticogram (ECoG) in late gestation. Fetal and maternal catheters were placed under general anesthesia and animals allocated at random to receive intratracheal maternal administration of either nitrogen (n = 8) or compressed air (n = 8). Five days after surgery (125 days’ gestational age), nitrogen infusion was adjusted to reduce fetal brachial artery PO2 by 25%. The targeted decrease in fetal oxygenation was maintained for 5 days while fetal ECoG activity and fetal and maternal cardiovascular variables were continuously recorded. Data are presented as mean ± SEM and were analyzed by two-way analysis of variance (ANOVA) or two-sample t test. Nitrogen infusion decreased fetal PO2 by 26% (20.5 ± 1.7 versus 14.3 ± 0.8) without changing fetal PCO2 or pH. Mild fetal hypoxemia was associated with fetal tachycardia and increased fetal blood pressure (P <.05). Fetal ECoG in hypoxic fetuses showed a significant decrease in the time spent in high voltage (HV) (P <.05) and an increase in the time spent in low voltage (LV) and in the number of low voltage events (P <.05). Also, a significant decrease in the proportion of 1–4 Hz and an increase in the proportion of 13–20 Hz frequencies was observed in LV events without a significant change in the frequency profile of HV events (P <.05). Prolonged mild hypoxemia significantly altered fetal homeostasis as reflected by the sustained tachycardia and increased blood pressure. Fetal ECoG activity was affected significantly in a qualitatively and quantitative manner by mild prolonged hypoxema.
The effects of lead upon collagen synthesis and proline hydroxylation in the Swiss mouse 3T6 fibroblast.

The effects of lead upon collagen synthesis and proline hydroxylation were examined in the Swiss mouse 3T6 fibroblast. The results indicate that lead reduces proline hydroxylation in stationary phase cultures of 3T6 cells, resulting in increased cellular retention of unhydroxylated procollagen. Inhibition of proline hydroxylation by lead was prevented by increasing the extracellular Fe2+Pb2+ molar ratio. Interference by lead in the hydroxylation of proline in logarithmic phase cultures of 3T6 cells resulted in increases in the 0.5 n HClO4 soluble/insoluble hydroxyproline ratio. This was attributed to an increase in the rate of breakdown of lead-induced unhydroxylated procollagen. Kinetic analysis of the lead-iron interaction with proline hydroxylase suggests that the mechanism is competitive.
Temporal Enhancement of Trapped Field in a Compact NMR Magnet Comprising YBCO Annuli

Temporal “enhancement” of trapped fields was observed in the central region of a compact NMR magnet comprising a stack of 2800 YBCO “square” annuli (YP2800), field-cooled at 4.2 K. This paper presents an analytical model to simulate the trapped field enhancement in YP2800. First, based on an inverse calculation technique, the current distributions in the 560 5-plate modules of YP2800 were computed from the measured trapped field distribution. Then, YP2800 was modeled as a set of “three magnetically-coupled subcoils”: the “bottom” coil (CB, 140 modules); the “middle” coil (CM, 280 modules); and the “top” coil (CT, 140 modules). With the index resistance of each coil included, the circuit model shows that the average current in CM “slowly” increases, induced by “fast” current decays in CB and CT. As a result, the center field in YP2800, dominated by the CM currents, increases in time. The simulation agrees reasonably well with the measurement, which validates the analytical model.
SOME NEW Dy II IDENTIFICATIONS IN THE SOLAR SPECTRUM.

Extension of the identification of singly ionized dysprosium lines in the solar chromosphere and disk has been made from a recently published laboratory analysis of the first and second spectrum.
Old Ways, New Impacts: Race, Residential Patterns, and the Home Foreclosure Crisis in the American South

The full impact of the U.S. housing crisis is still unfolding, with growing evidence that low-income groups and racial minorities have suffered the worst effects of foreclosure. This article addresses the spatial distribution of mortgage foreclosure in a Southern county that is residentially segregated in terms of race and wealth. We collected data manually from legal notices and public access property records between 2008 and 2011 and then used three basic approaches for analysis: visual identification, hot spot detection, and polygon-based spatial autocorrelation. We found that foreclosure activity followed the race–wealth divide by being heavily concentrated in older black neighborhoods, clustered in some white exurban developments, and largely absent from wealthy white areas. The results indicate that blacks and whites experience different patterns of foreclosure and that the housing crisis exacerbates geographical patterns of residential segregation.
A novel yeast histone deacetylase: partial characterization and development of an activity assay.

Abstract We have characterized a histone deacetylase activity associated with yeast nuclei. An unusual feature of the deacetylase is that it is not inhibited by the short-chain fatty acids n -butyrate and propionate. These short-chain fatty acids are typically potent inhibitors of histone deacetylases in eukaryotic systems. The deacetylase(s) were detected by monitoring the levels of acetylation of yeast histones during incubation of isolated yeast nuclei. The activity was optimal at 37°C and at 0.1 M NaCl. The enzyme did not require divalent cations and was inhibited by Zn 2+ and Cu 2+ . A simple activity assay was developed using as substrate, [ 3 H]acetate-labeled histone in chicken erythrocyte nuclei. This assay was used to demonstrate that the deacetylase(s) can be extracted from yeast nuclei with 0.5 M NaCl. A gel electrophoretic analysis of the deacetylated chicken histones verified that the solubilization of incorporated radiolabel was a result of histone deacetylation, not an artifact of histone degradation by yeast proteinases.
On the convergence of gangolli processes to brownian motion on a manifold

A stability theorem for stochastic differential equations is used to prove a result similar to one of Gangolli: let N be Riemannian manifold with the Levi-Civita connection, and let (Cn(t), O≦t≦T) ...
Expression of EGFR, VEGF, and NOTCH1 Suggest Differences in Tumor Angiogenesis in HPV-Positive and HPV-Negative Head and Neck Squamous Cell Carcinoma

There is current interest in anti-angiogenesis therapies for head and neck squamous cell carcinomas (HNSCC), although the utility of these therapies in human papillomavirus (HPV) positive and HPV-negative HNSCC is unclear. Therefore, we explored heterogeneity in expression of a distal factor in angiogenesis (EGFR, the epidermal growth factor receptor), a proximal factor in angiogenesis (VEGF, the vascular endothelial growth factor) and a putative factor in angiogenesis (NOTCH1) in a HNSCC case series using immunohistochemistry in N = 67 cases (27 HPV-positive, 40 HPV-negative, by in situ hybridization). Box plots and the Wilcoxon rank sum or Kruskal–Wallis tests were used to compare staining scores (intensity × percent of cells staining) by HPV status and lifestyle factors. Associations between EGFR, VEGF, and NOTCH1 were assessed using box plots and Spearman correlation (ρ) in all cases, and stratified by HPV status. HPV-negative HNSCC over-expressed EGFR [median (range): 30 (0–300)] relative to HPV-positive HNSCC [7.5 (0–200)] (P = 0.006). VEGF and NOTCH1 were unrelated to HPV status (P > 0.05). EGFR was associated with VEGF in HPV-negative (ρ = 0.40, P = 0.01) but not HPV-positive HNSCC (ρ = 0.25, P = 0.20). NOTCH1 and VEGF were associated in HPV-negative (ρ = 0.40, P = 0.01) but not HPV-positive tumors (ρ = −0.12, P = 0.57). NOTCH1 was not associated with EGFR (P > 0.05). Our results are suggestive of heterogeneity in HNSCC angiogenesis. Future studies should explore angiogenesis mechanisms in HPV-positive and HPV-negative HNSCC.
Flow pattern transition for gas-liquid flow in a vertical rod bundle

Abstract Experimental and analytical studies are presented directed to the prediction of flow pattern transitions in a vertical rod bundle array. The test section used consists of a 24 rod matrix on a square pitch in a cylindrical shell. Analytical models are given based on physical interpretation of the transition mechanisms. Data on rise velocities of small and large bubbles in rod bundles are also presented.
Prognostic value of exercise echocardiographyin 5,798 patients: is there a gender difference?

Abstract Objectives This study was designed to determine the effect of gender on the prognostic value of exercise echocardiography. Background Limited information exists regarding gender differences in prognostic value of exercise echocardiography. Methods We obtained follow-up (3.2 ± 1.7 years) in 5,798 consecutive patients who underwent exercise echocardiography for evaluation of known or suspected coronary artery disease. Results There were 3,322 men (mean age 62 ± 12 years) and 2,476 women (mean age 62 ± 12 years) (p = 0.7). New or worsening wall motion abnormalities developed with exercise in 35% of men and 25% of women (p = 0.001). Cardiac events, including cardiac death (107 patients) and nonfatal myocardial infarction (148 patients), occurred in 5.3% of men and 3.1% of women (p = 0.001). Addition of the percentage of ischemic segments to the clinical and rest echocardiographic model provided incremental information in predicting cardiac events for both men (X2= 137 to 143, p = 0.014) and women (X2= 72 to 76, p = 0.046). By multivariate analysis, exercise electrocardiographic and exercise echocardiographic predictors of cardiac events in both men and women were workload and exercise wall motion score index. There was no significant interaction effect of rest echocardiography (p = 0.79), exercise electrocardiography (p = 0.38) or exercise echocardiography (p = 0.67) with gender. Conclusions Although cardiac events occurred more frequently in men, the incremental value of exercise echocardiography was comparable in both genders. Of all exercise electrocardiographic and exercise echocardiographic variables, workload and exercise wall motion score index had the strongest association with outcome. The results of exercise echocardiography have comparable implications in both men and women.
Cortically induced rhythmic activities in the thalamic ventrolateral nucleus of the cat

Abstract The effect of stimulation of the anterior sigmoid gyrus on the thalamic ventrolateral nucleus (VL) was studied by recording both focal VL potentials and by intracellular activity from VL relay neurons in locally anesthetized immobilized cats, with spinal cord transection at C2 level. Single stimuli applied to the cortex evoked a sequence of negative and positive waves in VL. When double shocks were applied the short-latency negative potential evoked by the second shock was successively potentiated and depressed coincidently with the negative and positive waves induced by the first shock. The response of VL relay neurons consisted of a short-latency spike evoked antidromically or orthodromically, followed by a prolonged IPSP undergoing rhythmic changes similar to those seen in the cortically induced VL focal potential. When double shocks were applied to the cortex, the IPSP evoked by the second shock did not exceed the peak of the IPSP evoked by the first shock. At certain intervals, the second shock evoked a short-latency depolarizing wave, the nature of which was inferred to be an EPSP.
The effect of dorsal cochlear nucleus ablation on tinnitus in rats

A growing body of evidence implies that the dorsal cochlear nucleus (DCN) plays an important role in tinnitus. To test the hypothesis that the rostral output of the DCN is necessary for the experience of chronic tinnitus, the dorsal DCN and the dorsal acoustic stria of rats with psychophysical evidence of tinnitus was ablated. If the DCN plays a necessary role in the generation of chronic tinnitus, ablating the DCN should decrease the evidence of tinnitus in subjects previously shown to have tinnitus. Contrary to prediction, bilateral dorsal DCN ablation did not significantly (n=11, p=0.707) affect the psychophysical evidence of tinnitus, and ipsilateral dorsal DCN ablation appeared to increase the evidence of tinnitus (n=9, p=0.018) compared to pre-ablation performance. It was concluded that the DCN does not act as a simple feed-forward source of chronic tinnitus. Alternative hypotheses were considered, among them that elevated DCN activity following acoustic trauma triggers persistent pathological changes distributed across more than one level of the auditory system. In addition to serving as a trigger, the DCN may also modify the experience of tinnitus, since the evidence of tinnitus was enhanced by ipsilateral DCN ablation.
IS CRITICAL THINKING EPISTEMICALLY RESPONSIBLE

: There are at least three strategies we might take in approaching controversial issues: (i) we might accept the conclusions of experts on their authority, (ii) we might evaluate the relevant evidence and arguments for ourselves, or (iii) we might give up on finding the answers. Students of “critical thinking” are regularly advised to follow strategy (ii). But strategies (i) and (iii) are usually superior to (ii), from the standpoint of the goal of gaining true beliefs and avoiding false ones.
Intrusion of aortic root into mitral orifice in hypertensive disease radiologic observations on living persons.

Abstract 1. 1. Fundamentals for the radiologic demonstration of anatomic relationship of the root of the aorta to the mitral ostium in living persons, in the presence of intracardial annular calcifications, are described. 2. 2. Three cases of hypertensive disease are presented, in which the radiologic examination showed that the root of the aorta intruded into the mitral ostium and caused loss of the cross-section area of the orifice. 3. 3. There is indication that the aortic root may encroach on the mitral orifice also in cases of hypertensive disease, in which absence of calcifications does not permit the radiologic demonstration of these structures.
Narrow-band expansions in the Hubbard model A comment.

The connection between a solution of the Hubbard Hamiltonian obtained by Esterling and Lange and the low-density solution is discussed. It is shown that their solution agrees to first order in the bandwidth with the exact solution for the two-electron $N$-site case. However, even this correct first-order expansion fails to adequately account for the low-frequency behavior of the Green's function and related quantities.
ENU-induced mutagenesis at a single A: T base pair in transgenic mice containing Φ X174

Abstract Transgenic mice containing the bacteriophage ΦX174 am3 as a chromosomally integrated and recoverable marker for in vivo mutation have been produced to measure spontaneous and induced substitutions at an A: T base pair among single copies. ΦX174 was chosen for its small size (5 kb), unique sequence, and the opportunity to take advantage of previously reported in vitro data on mutation and repair; the am3 site provides sequence specificity in a reversion assay for mutation of an A: T base pair. Inbred C57B1/6 mice have been made homozygous for approximately 100 copies of the phage sequence without any apparent detrimental effects on the homozygous individuals. Recoveries of phage from mouse tissues are in the range of 1–5 × 10 7 PFU per μg mouse DNA; both recovery and mutation are independent of endogenous CpG methylation. Background mutation frequencies are 2–4 × 10 −7 among phase recovered from liver, brain, spleen, and kidney. Adult mice were treated with 200 mg/kg N -ethyl- N -nitrosourea, and phage were recovered at 2 and 14 days after treatment. At 2 days after treatment we observed a slight increase only among phage isolated from the brain of one mouse out of four. At 14 days after ENU treatment, there were significant increases in mutation frequencies among phage recovered from the liver (6×) and spleen (10×). These results demonstrate (1) response of a single A: T base pair to alkylation-induced mutation in a nonexpressed gene, (2) the role of cell proliferation in somatic mutagenesis, and (3) provide a model for a transgenic approach for study of site-specific mutagenesis in vivo in higher eukaryotes.
Maximum Palatal Height in Patients with Turner's Syndrome

A specially designed palatal height gauge demonstrated the mean palatal height of the dental casts of 14 female patients with Turner's syndrome to be higher in all age categories than in a normal control population. Also, palatal height was found to increase with age in both control and experimental groups.
Within-limb somatotopy in primary motor cortex - revealed using fMRI

Abstract Introduction Controversy exists regarding within-limb somatotopy, i.e., organization of representations of within-limb segments (e.g., elbow, fingers), in the primary motor cortex (M1). While some believe that within-limb representations overlap, others postulate somatotopic distinction. The purpose of our study was to aid the resolution of this controversy by exploring a) overlap between finger and elbow representations using high-resolution functional magnetic resonance imaging (fMRI), b) somatotopic differences between the two representations with and without the overlap, c) different location markers – center of mass (COM) and peak of activation (POA) and d) intensity differences between the two representations with and without the overlap. Methods Twenty-four subjects underwent fMRI during finger and elbow tracking for definition of activation-based finger and elbow representations and their overlapping parts. Differential analysis was used to generate parts of finger and elbow representations that did not overlap. Location measures, COM and POA and fMRI signal intensity for all parts of finger and elbow representations were recorded. Results Finger and elbow representations overlap but still possess distinct somatotopic centers, i.e., finger is lateral to overlap, which is lateral to the elbow. When overlap is excluded, locations of finger and elbow representations become more distinct. COM shows distinction along x, y and z-axes, but POA only shows distinction along the x-axis. Overlap has the highest intensity, while non-overlapping finger and elbow representations have the lowest intensity during finger and elbow tracking, respectively. Conclusions Somatotopic gradients exist in M1 despite the overlap. This finding supports ‘functional somatotopy’, i.e., within-limb representations overlap for multi-joint coordination, yet possess discrete centers for individuated control. Such a flexible somatotopy might allow representational reorganization. COM could be marker for ‘location’ and POA within in a high-intensity zone could emphasize ‘reorganization’ following learning/disease. Also, fMRI intensity could be a marker of change of overlap or somatotopic distinction.
The transition from hydrostatic to greater than hydrostatic fluid pressure in presently active continental hydrothermal systems in crystalline rock

Fluid flow at hydrostatic pressure (P{sub h}) is relatively common through fractures in silicic and in mafic crystalline rocks where temperatures are less than about 350-370C. In contrast, pore-fluid pressure (P{sub f}) > P{sub h} has been encountered at the bottom of 3 geothermal exploration wells that attained temperatures >370C (at Larderello, Italy, at Nesjavellir, Iceland, and at The Geysers, California). Chemical sealing by deposition of minerals in veins appears to have allowed the development of the high P{sub f} encountered in the above wells. The upper limit for the magnitude of P{sub f} that can be attained is controlled by either the onset of shear fracturing (where differential stress is relatively high) that reopens clogged veins, or the hydraulic opening of new or old fractures (at relatively low values of differential stress). The brittle-plastic transition for silicic rocks can occur at temperatures as high as 370-400C in tectonically active regions. In regions where high-temperature geothermal systems develop and persist, it appears that either strain rates commonly are in the range 10{sup {minus}12} to 10{sup {minus}13}, or that silicic rocks in the shallow crust generally behave rheologically more like wet quartz diorite than wet Westerly granite.
The effect of carbon dioxide on cerebral arteries

The constancy of cerebral blood flow and volume relies heavily upon the cerebral arteries' intrinsic ability to respond to changes in the partial pressure of arterial CO2. The physiologic mechanisms underlying these responses have not been determined, although changes in extracellular and intracellular pH, mediation by prostanoids and neural activity have been suggested. CO2 reactivity can be influenced by oxygen status and blood pressure and can vary according to age and brain region. In certain pathological conditions or diseases, it can be severely altered. Modern techniques, which measure CBF in cases of cerebral hemodynamic insufficiency, head injury or tumor, rely on the inherent ability of the cerebral circulation to respond to changing levels of CO2.
Aggregation of risk: relationships among host-parasitoid models

We explore the relationships among host-parasitoid models involving aggregation, with particular emphasis on May's negative binomial model. Models in which parasitoid density in a patch is strictly a function of host density in the patch, with no "error" about this function, are pure-regression models. Those in which there is random variation in the number of parasitoids per patch, with no relationship between local parasitoid density and local host density, are pure-error models. The key factor in these models is not the distribution of parasitoids per se, but the distribution of the relative risk of parasitism, p, which in the present formulation can result from variation in the number of parasitoids in a patch, Pj, or from variation in host vulnerability, a. We show that May's model, and the Bailey et al. (1962) model of which it is a special case, arises naturally from pure-error models. By contrast, it is very difficult to obtain May's model from biologically plausible pure-regression models. There a...
Conformations of lysine-sensitive aspartokinase

Abstract 1. 1.|The technique of differential thermal and proteolytic inactivation has been employed as a conformational probe for the lysine-sensitive aspartokinase (EC 2.7.2.4) of Escherichia coli B. 2. 2.| l -Amino acid inhibitors of this enzyme each induce a characteristic enzyme conformation. This is evidenced by rates of thermal and proteolytic inactivation and Arrhenius activation energies for thermal inactivation which are characteristic of the amino acid present. 3. 3.|Phenylalanine and leucine binding are mutually exclusive as evidenced by competitive behavior in thermal inactivation experiments, suggesting a hydrophobic amino acid binding site with broad specificity. 4. 4.|The phenylalanine-dependent conformation and the leucine-dependent conformation differ considerably. In comparison with the native enzyme, the former is more labile to proteolysis by trypsin whereas the latter is more stable. First-order rate constants for thermal inactivation of the phenylalanine- and leucine-dependent conformations are, respectively, about one-half and one-tenth that of the native enzyme. 5. 5.|Items 3 and 4 taken together suggest that the conformations are ligand induced and do not arise via ligand stabilization of spontaneously arising conformers.
Semiclassical calculation of oscillator-strengths

We describe a simple semiclassical approximation for electron matrix-elements and oscillator strengths. The method is tested by detailed comparison with known exact results for the Coulomb potential and proves to be numerically robust and reasonably accurate for all transitions examined Nous decrivons une approximation semi-classique simple qui permet de calculer les elements de matrice electronique et les forces d'oscillateur. La methode est testee grâce a une comparaison detaillee avec des resultats exacts connus pour le potentiel coulombien; elle s'avere numeriquement fiable et raisonnablement precise pour toutes les transitions examinees
Low temperature photodissociation studies of ferrous hemoglobin and myoglobin complexes by Mössbauer spectroscopy.

Abstract 57 Fe-enriched complexes of hemoglobin and myoglobin with CO and O 2 were photodissociated at 4.2°K, and the resulting spectra were compared with those of the deoxy forms. Differences in both quadrupole splitting and isomer shift were noted for each protein, the photoproducts having smaller isomer shift and larger quadrupole splitting than the deoxy forms. The photoproducts of HbCO and HbCO 2 had narrow absorption lines, indicating a well-defined iron environment. The corresponding myoglobin species had broader absorption lines, as did both deoxy forms. The weak absorption lines of photodissociated NO complexes appeared to be wide, possibly indicating magnetic interaction with the unpaired electron of the nearby NO.
Explicit two-loop calculation of decoupling in unbroken gauge theories with fermions

Abstract Unbroken gauge theories containing light as well as heavy fermions are considered in the limit of the mass of the heavy fermions tending to infinity. The effective coupling constant of the decoupled low-energy theory thus obtained, has been calculated up to two-loop level using the light particle irreducible vertex function and the background field formalism. In addition, to simplify the computation, a background field gauge-fixing term has been used, because in such a gauge the effective coupling constant can be calculated from a two-point function only. Our analysis reveals that in the non-abelian theory, the simple algorithm proposed by Ovrut and Schnitzer for computing the effective coupling constant up to the two-loop level is valid only in the α = 0 or α = −3 background field gauge. A general procedure correct for all values of α is described.
Maintenance of relaxation-induced blood pressure reductions: the importance of continued relaxation practice.

This study examined the long-term importance of continued relaxation practice in the maintenance of relaxation-induced blood pressure reductions. An ABAB withdrawal-reinstatement design was employed with two hypertensive subjects. An objective, unobtusive measure of home relaxation practice was used to monitor compliance. Subject I showed substantial reductions in systolic and diastolic blood pressure during 3 months of relaxation practice, followed by a 60% return to baseline during withdrawal, and a subsequent decrease with reinstatement of relaxation. Subject 2 showed a pattern similar to that of Subject 1 for systolic blood pressure, though the trend for diastolic pressure was unclear owing to a marginal treatment response. These preliminary data suggest that continued relaxation practice may be an important factor in the maintenance of relaxation-induced blood pressure reductions.
Exploring the “That's-Not-All” Effect: A Test of Theoretical Explanations

The “that's-not-all” (TNA) technique is a sequential request strategy in which an offer is improved before the message receiver responds. Although the TNA procedure has been the subject of several experiments, the theoretical mechanisms responsible for TNA effects are unclear. An experiment, utilizing a 3 (Request type: large TNA, moderate TNA, control) × 2 (Requester: prosocial, commercial organization) independent groups design, was conducted to investigate the moderators of the TNA effect. Three theoretical explanations were tested: perceptual contrast, reciprocal concessions, and social responsibility. The compliance rates were consistent with the traditional perceptual contrast and social responsibility explanations; however, the perceptual data were only consistent with social responsibility. The results have practical significance to people wishing to employ the TNA technique.
Social-Ecological Constraints on Children's Communicative Strategies

This paper focuses on how the socio-ecological environment provides specific socially-defined opportunities for interaction and talk. The socially defined character of the different areas of a nurs...
HIV post-exposure prophylaxis in children and adolescents presenting for reported sexual assault

Abstract Background The appropriate use of antiretroviral medications to protect against infection with human immunodeficiency virus (HIV) is unclear in cases of sexual assault of children, for whom the perpetrator's risk of HIV is often unknown, and physical proof of sexual contact is usually absent. Objective In an effort to clarify prescribing practices for HIV post-exposure prophylaxis (PEP) at our institution, we examined records of all children tested for HIV for prevalence of infection, our experience with prescribing PEP, and follow-up rates. Design/methods Medical records at a sexual abuse clinic of all children tested for HIV during a 38-month period were reviewed for information concerning risk factors for HIV acquisition, STI test results, and PEP experience. Children were defined as PEP-eligible if they were within 96 hours of assault, and there was a report of sexual contact with the potential to transmit HIV. Results One thousand seven hundred and fifty children were tested for HIV during the study period. Five children had a positive HIV ELISA, but only one child was confirmed HIV-positive. Three hundred and three children were eligible to receive HIV-PEP, but it was only offered to 16 (5.3%), of whom 15 accepted the medications. None of the children prescribed PEP completed follow-up, but 11 children had limited follow-up. Conclusions Our results indicate that the prevalence of HIV infection among sexually abused children in our population is low, and follow-up rates are poor. Intensive efforts to try to ensure follow-up are warranted whenever PEP is prescribed. Further research may help better define the efficacy of PEP in sexually abused children and adolescents.
TUNING THE COSMOLOGICAL CONSTANT IN N=1 SUPERGRAVITY WITH AN R SYMMETRY

Abstract An explicit example of a hidden sector for the spontaneous breaking of N = 1 local supersymmetry with ah R-symmetry is constructed. It is shown that the cosmological constant of this example can be made to vanish by tuning the parameters of a non-trivial Kahler potential.
Sex-linked genes in age-structured populations

We study the progress towards equilibrium of the frequencies of sex-linked genes in elementary discrete time models of age-structured, overlapping generation populations. It is found that, if a finite upper age limit is assumed, the difference in the frequencies of an allele in males and females will oscillate as in the familiar non-overlapping generation models, although the oscillations may be irregular. Monotonic convergence of that difference, as found by Nagylaki (1975) in continuous-time overlapping generation models without age-structure, occurs in the models considered here only when there is no upper age limit and when there is “ sufficient “ overlap of generations.
Effect of Local Hypothermia on Early Wound Repair

Local hypothermia has been shown to enhance survival of pedicled skin flaps. The effect of prolonged local hypothermia on an important clinical correlate, wound healing, is examined in this study. Skin incisions were made on each flank of nine female pigs, and these incisions were closed primarily. A cooling pad was applied over the incisions on the right side of each animal, achieving an average dermal temperature of 35 degrees C vs 39 degrees C for the control side. Four animals were treated for 72 hours postoperatively; five pigs were treated for 7 days. Wound repair was evaluated by standard histologic techniques at 24 hours, 72 hours, 7 days, and 14 days. Control wounds in all animals demonstrated the normal progression of primary wound repair. We demonstrate that local hypothermia: (1) inhibits wound repair for the duration of its application; (2) is not detrimental to the early 2-week phase of wound healing if applied for 72 hours postoperatively; and (3) may have a beneficial effect by inhibiting inflammation through delay of the late inflammatory phase of wound healing.
Selection of fusion operations using rank-score diversity for robot mapping and localization

In this paper, we evaluate the use of a rank-score diversity measure for selecting sensory fusion operations for a robot localization and mapping application. Our current application involves robot mapping and navigation in an outdoor urban search and rescue situation in which we have many similar and mutually occluding landmarks. The robot is a 4-wheel direct drive platform equipped with visual, stereo depth and ultrasound sensors. In such an application it's difficult to make useful and realistic assumptions about the sensor or environment statistics. Combinatorial Fusion Analysis(CFA) is used to develop an approach to fusion with unknown sensor and environment statistics. A metric is proposed that will indicate when fusion from a set of fusion alternatives will produce a more accurate estimation of depth than either sonar or stereo alone and when not. Experimental results are reported to illustrate that two CFA criteria are viable predictors to distinguish between positive fusion cases (the combined system performs better than or equal to the individual systems) and negative cases.
The hsp90 Co-chaperone XAP2 Alters Importin β Recognition of the Bipartite Nuclear Localization Signal of the Ah Receptor and Represses Transcriptional Activity

The mouse aryl hydrocarbon receptor (mAhR) is a ligand-activated transcription factor that exists in a tetrameric, core complex with a dimer of the 90-kDa heat shock protein, and the hepatitis B virus X-associated protein 2 (XAP2). Transiently expressed mAhR-YFP (yellow fluorescent protein fused with the mAhR) localizes throughout cells, with a majority occupying nuclei. Co-expression of XAP2 with mAhR-YFP results in a distinct redistribution to the cytoplasm. We have utilized several approaches to attempt to identify the mechanism by which XAP2 modulates the sub-cellular localization of the mAhR. The nuclear export inhibitor, leptomycin B, was used to demonstrate that XAP2 inhibits ligand-independent nucleocytoplasmic shuttling of the receptor. Results from cytoskeletal disruption and the addition of an alternate nuclear localization sequence (NLS) to mAhR-YFP suggest that XAP2 does not physically tether the complex in the cytoplasm. The use of a rabbit polyclonal antibody raised against a portion of the bipartite NLS of the mAhR revealed that XAP2 does not appear to block access to the NLS. However, XAP2 hinders importin beta binding to the mAhR complex, suggesting that XAP2 alters the conformation of the bipartite NLS of mAhR. XAP2 also represses the transactivation potential of the AhR, in contrast to previously published reports, perhaps by stabilizing the receptor complex and/or blocking nucleocytoplasmic shuttling of the AhR complex.
Measurement of myocardial infarct size by technetium pyrophosphate single-photon tomography*

The primary determinant of prognosis after acute myocardial infarction (AMI) is the size of the acute infarct. The present study evaluates 46 patients with different infarct distributions and sizes to test the hypothesis that single photon emission computed tomography with technetium-99m pyrophosphate (Tc-99m-PPi) and blood pool overlay allows measurements of AMI size that provide insight into prognosis irrespective of infarct location. Identical Tc-99m-PPi and ungated blood pool projections were acquired over 180 degrees with a rotating gamma camera. Reconstructed sections were color-coded and superimposed for purposes of infarct localization. Areas of increased pyrophosphate uptake within myocardial infarcts were thresholded at 65% of peak activity. The blood pool was thresholded at 50% and subtracted so as to determine an endocardial border for the left ventricle. Using this method, myocardial infarcts weighed 2.5 to 81.2 g. The correlation of infarct mass with prognosis showed that patients without previous AMI and with acute infarcts that weighed more than 40 g had an increased frequency of death and congestive heart failure (p less than 0.001). The correlation of measured infarct mass with peak serum creatine kinase level was significant (r = 0.83, p less than 0.001; y = 0.015x + 13.20). The correlation coefficients for anterior, inferior and nontransmural AMI were not significantly different from those for the entire group. In conclusion, tomographically determined infarct mass data correlate with subsequent clinical prognosis, and Tc-99m-PPi tomography with blood pool overlay is a safe and effective means of sizing infarcts in patients with AMI.
The mammalian cdc2 protein kinase: mechanisms of regulation during the cell cycle

Recent experimental evidence has demonstrated the central role of the cdc2 protein kinase in the transition from G2 to M phase in eukaryotic cells. We shall review our knowledge of the mechanisms which coordinate activation of the kinase with cell cycle-specific events in mammalian cells.
Ecology of larval herring in relation to the oceanography of the Gulf of Maine

The dynamics of larval herring in the north-eastern Gulf of Maine are reviewed with reference to the important physical and biological oceanographic processes of the region. Particular attention is geven to the apparently conflicting hypotheses of larval drift from the tidally well-mixed spawning areas to nursery areas, and larval retention in spawning areas for a period of several months
The reliability and utility of high reported specific rotations: reports and predictions of molecules with extremely high specific rotations, and high specific rotations suggest revision of the structures of huperzines E′ and F′

A search of the literature for all compounds with [α]D>1000 found 13 molecules with reliably determined specific rotations in excess of 6500, as judged by comparison with DFT-calculated values of [α]D for the same compounds, with a maximum [α]D −11,560 for a decacyclic helicene quinone. Several reports of [α]Ds ranging from 10,000 to 44,000 were judged to be spurious. On the basis of similar computational studies, several molecules are proposed that should have very high [α]Ds but relatively modest visible absorptions, unlike the current record holders, which have strong absorption near the sodium D line. In addition, the search found two natural products, huperzines E′ and F′, that have large reported [α]Ds (−4750 and −3182, respectively), that are inconsistent with their structures. However, computational studies found epimers of the reported structures that possess [α]Ds consistent with the reported chiroptical data.
The Emergence of Non-Match-to-Sample Behavior in the Developing Rat Pup.

Between 15 and 18 days of age, rat pups develop an alternation strategy in a spatial non-match-to-sample task. Adapting the rat pups to the apparatus by housing them in it overnight, the difference in behavioral patterns can readily be observed in a single laboratory session. The opportunity of the pups to “nipple attach” to an anesthetized dam serves as the reinforcer. Discussion questions are formulated that encourage students to analyze the behaviors structurally, functionally and developmentally.
A truncated, secreted form of the epidermal growth factor receptor is encoded by an alternatively spliced transcript in normal rat tissue.

Abstract Two independent cDNA clones corresponding to a 2.7-kilobase (kb) epidermal growth factor receptor (EGF-R) mRNA were isolated from a rat liver cDNA library. Sequence analysis revealed 100% homology in the external domain when compared with the full-length rat EGF-R nucleotide sequence and 80 to 90% similarity relative to the human EGF-R. However, the 3'-terminal sequence of these clones did not match EGF-R or any other known sequence(s) and was distinct from the 3' end of the 2.8-kb mRNA, which encodes a truncated EGF-R in A431 cells. The deduced amino acid sequence revealed an open reading frame which is homologous to the external domain of the EGF-R but which terminates prior to the transmembrane region. Southern blot analysis of rat genomic DNA indicated that the 3'-terminal sequence of this transcript is derived from the EGF-R gene. Analysis of a genomic clone containing the 3' end of the 2.7-kb transcript revealed that this sequence is present as a discrete exon in the mid-region of the receptor gene in proximity to the exon encoding the transmembrane domain. Introduction of an expression vector containing the truncated EGF-R cDNA into Chinese hamster ovary (CHO) cells led to the expression of a 95-kilodalton protein which was detected in conditioned media, by using antisera directed against the EGF-R. A similarly sized protein was also detected in the media of WB cells, a continuous, nontransformed line of rat hepatic epithelial cells. Northern (RNA blot) analysis established that the truncated receptor is encoded by a 2.7-kb transcript found in normal rat liver. Furthermore, Northern analysis of rat poly(A)+ RNA showed that the 2.7-kb EGF-R transcript is expressed at differing levels in various fetal and adult tissues. These data indicate that alternative splicing of the EGF-R primary transcript yields a 2.7-kb mRNA which codes for a truncated form of the receptor. This receptor is secreted by rat hepatic epithelial cells in culture, which suggests that it may be secreted by normal rat cells or tissues and perhaps serve an as yet unknown physiological function.
Practical asynchronous controller design

The authors evaluate their proposed asynchronous state-machine synthesis method, which uses locally synthesized clocks, on two realistic examples: a DRAM controller and a small computer systems interface controller. These circuits are designed to satisfy existing interface specifications, and are substantially larger than interfaces that have been created by competing methods, such as signal transition graph synthesis. The performance of the resulting implementations is at least as good as that of comparable synchronous implementations. >
Espoused drum-buffer-rope flow control in serial lines: A comparative study of simulation models

Abstract This paper documents an investigation of drum-buffer-rope (DBR) scheduling and flow control methodology in single-product serial production lines. In particular, DBR flow control is reviewed and the importance of correctly representing this type of flow control mechanism in serial lines is discussed. Departures from valid DBR conceptual and simulation modeling are illustrated. It is shown that the model of a previously published paper is a push system not a DBR system, and that related conclusions regarding protective capacity and constraint location are unsupported. Correct modeling of DBR flow control is shown using discrete simulation experiments that compare the DBR model and a similar push model. Suggestions for additional research are offered.
On the response of an elastically supported rigid disk with a moving massive load

Abstract An analysis of the dynamic response of an elastically supported 3-degree-of-freedom rigid circular disk excited by a moving massive load is presented. A solution is obtained by transforming a set of ordinary nonlinear differential equations with periodic coefficients to a set of linear differential equations with constant coefficients. Three different types of system instability are observed. An unstable region exists immediately above the critical speed of the disk. Another unstable region arises when the load velocity is such that the frequency of two different disk modes is nearly the same. A terminal instability region exists for all load speeds above a certain limiting value. The addition of viscous damping may destabilize the system.
Electrochemical Corrosion and Protection of Molybdenum and Molybdenum Disilicide in a Molten Soda-Lime Silicate Glass Environment

Electrochemical corrosion of Mo and MoSi2 in a molten soda-lime silicate glass environment was studied using a two-electrode cell with Pt as the counterelectrode. XRD, SEM, and EDS were used to characterize the corroded specimens. When Mo was cathodically polarized (-1 V), no corrosion and a Mo surface were observed after 12 h of electrochemical corrosion. Under anodic polarization (+1 V), higher corrosion (0.42 mm) was observed due to formation of MoO2, which did not form a coherent passive layer. Cathodic protection occurred by electrostatic repulsion of oxygen ions, thus discouraging oxidation of Mo. Anodically polarized (+1 V) MoSi2 showed a significant decrease in recession at the glass line due to formation of SiO2 product which attenuated convective flow currents. Accelerated corrosion was observed under cathodic polarization (-1 V), where streams of Mo particles were observed flowing downward in the melt. MoSi2 was interpreted to decompose into neutral molybdenum and silicon anions, which were rejected into the melt.