cssi/SciSciGPT-SciSciNet huggingface dataset:
Catch-and-hold activation of muscle acetylcholine receptors having transmitter binding site mutations.

Agonists turn on receptors because their target sites have a higher affinity in the active versus resting conformation of the protein. We used single-channel electrophysiology to measure the lower-affinity (LA) and higher-affinity (HA) equilibrium dissociation constants for acetylcholine in adult-type muscle mouse nicotinic receptors (AChRs) having mutations of agonist binding site amino acids. For a series of agonists and for all mutations of αY93, αG147, αW149, αY190, αY198, eW55, and δW57, the change in LA binding energy was approximately half that in HA binding energy. The results were analyzed as a linear free energy relationship between LA and HA agonist binding, the slope of which (κ) gives the fraction of the overall binding chemical potential where the LA complex is established. The linear correlation between LA and HA binding energies suggests that the overall binding process is by an integrated mechanism (catch-and-hold). For the agonist and the above mutations, κ ∼ 0.5, but side-chain substitutions of two residues had a slope that was significantly higher (0.90; αG153) or lower (0.25; eP121). The results suggest that backbone rearrangements in loop B, loop C, and the non-α surface participate in both LA binding and the LA ↔ HA affinity switch. It appears that all of the intermediate steps in AChR activation comprise a single, energetically coupled process.
Axenic cultivation of Entamoeba dispar Brumpt 1925, Entamoeba insolita Geiman and Wichterman 1937 and Entamoeba ranarum Grassi 1879

Three species of Entamoeba have been grown in axenic culture for the first time. In two cases, novel methods for adapting the organisms to growth without bacteria were employed. While E. ranarum was axenized by the classic technique of Diamond, from a monoxenic culture with Trypanosoma cruzi as the associate, both E. dispar and E. insolita were first grown in axenic culture medium supplemented with lethally irradiated bacteria. From there, E. insolita was axenized directly, but E. dispar initially required the presence of fixed bacteria. After prolonged culture under this technically axenic but unwieldy culture system, E. dispar was eventually adapted to growth in the absence of added bacteria.
Gα12 and Gα13 Negatively Regulate the Adhesive Functions of Cadherin

Cadherins function to promote adhesion between adjacent cells and play critical roles in such cellular processes as development, tissue maintenance, and tumor suppression. We previously demonstrated that heterotrimeric G proteins of the G12 subfamily comprised of Gα12 and Gα13 interact with the cytoplasmic domain of cadherins and cause the release of the transcriptional activator β-catenin (Meigs, T. E., Fields, T. A., McKee, D. D., and Casey, P. J. (2001) Proc. Natl. Acad. Sci. U. S. A. 98, 519–524). Because of the importance of β-catenin in cadherin-mediated cell-cell adhesion, we examined whether G12 subfamily proteins could also regulate cadherin function. The introduction of mutationally activated G12proteins into K562 cells expressing E-cadherin blocked cadherin-mediated cell adhesion in steady-state assays. Also, in breast cancer cells, the introduction of activated G12 proteins blocked E-cadherin function in a fast aggregation assay. Aggregation mediated by a mutant cadherin that lacks G12 binding ability was not affected by activated G12 proteins, indicating a requirement for direct G12-cadherin interaction. Furthermore, in wound-filling assays in which ectopic expression of E-cadherin inhibits cell migration, the expression of activated G12 proteins reversed the inhibition via a mechanism that was independent of G12-mediated Rho activation. These results validate the G12-cadherin interaction as a potentially important event in cell biology and suggest novel roles for G12 proteins in the regulation of cadherin-mediated developmental events and in the loss of cadherin function that is characteristic of metastatic tumor progression.
Integrable spin-1 Heisenberg chain with impurity

We construct an integrable SU(2)-invariant model consisting of the Heisenberg chain of spin 1 interacting with an impurity of spin S. This generalizes previous results by Andrei and Johannesson for the spin-(1/2 chain. The model Hamiltonian is diagonalized and the thermodynamics is obtained. For ferromagnetic coupling at low temperatures the impurity susceptibility diverges as ${T}^{\mathrm{\ensuremath{-}}2}$ and the impurity specific heat is proportional to ${T}^{1/2}$ for all values of the impurity spin S. For antiferromagnetic coupling and T=0 the impurity susceptibility diverges proportionally to \ensuremath{\Vert}lnH\ensuremath{\Vert} as H\ensuremath{\rightarrow}0 if S=(1/2, while if Sg1 the impurity spin is only partially compensated for by the S=1 chain.
Tin and antimony valence states in BaSn0.85Sb0.15O3−δ

{sup 119}Sn and {sup 121}Sb Moessbauer spectra indicate the presence of Sb{sup 5+} and Sn{sup (4{minus}x)+} ions down to 1.2 K without evidence for disproportionation into Sn{sup 2+}, Sn{sup 4+} or Sb{sup 3+}, Sb{sup 5+}. It is argued that stabilization of Sb{sup 5+}, which means a lifting of the donor level above E{sub F}, is accomplished by a static oxide-ion displacement from Sn toward Sb in a 180{degree} Sn-O-Sb link. Placement of E{sub F} within an enhanced density of states at the bottom of the Sn-5s {sigma}* band eliminates optical excitations to the conduction band from an impurity band; it is suggested that this situation is a necessary condition for a transparent conductor like In{sub 2}O{sub 3}:Sn. The model also permits rationalization of a low, temperature-independent conductivity.
Truth and consequences of ordinal differences in statistical distributions: toward a theory of hierarchical inference.

A theory is presented that establishes a dominance hierarchy of potential distinctions (order relations) between two distributions. It is proposed that it is worthwhile for researchers to ascertain the strongest possible distinction, because all weaker distinctions are logically implied. Implications of the theory for hypothesis testing, theory construction, and scales of measurement are considered. Open problems for future research are outlined. There are many occasions in psychological research when experimenters are concerned with two or more treatments and their effects on experimental groups. In most instances, the measurements assessing the treatments are assumed to be on at least an ordinal scale. The measurements typically form a sample probability distribution. The investigator may then ask the question as to whether the two distributions differ from one another in some way. The way chosen is often through the testing of summary statistics, particularly sample means, but there are techniques that test entire distributions against one another. In this article I develop a theory that shows that some differences between the distributions are stronger than others, in that the stronger ones imply the weaker ones but not vice versa. In fact, a dominance hierarchy of distinctions between two arbitrary distributions is developed: A distinction may imply another, be implied by another, be equivalent to another, or none of these. The dominance hierarchy is put into the form of an implication graph. The power of the results is that they are, except for special cases to be specified later, general across distributions. That is, most of the relations do not depend on a particular type of distribution such as the normal distribution. Furthermore, as long as the measurements are on at least an ordinal scale, again with the exception of the special cases, they
Development of a Pediatric Cardiology Quality Improvement Collaborative: From Inception to Implementation. From the Joint Council on Congenital Heart Disease Quality Improvement Task Force

While clinical outcomes in pediatric cardiac disease have improved in recent years, marked institutional and individual cardiology practice variability exists. Quality improvement science has demonstrated that reducing process variation leads to more favorable outcomes, safer practices, cost savings, and improved operating efficiency. This report describes the process undertaken to develop the first collaborative quality improvement project of the Joint Council on Congenital Heart Disease. The project chosen aims to reduce mortality and improve the quality of life of infants with hypoplastic left heart syndrome during the interstage period between discharge from the Norwood procedure and admission for the bidirectional Glenn procedure. The objective of this special article is to inform the pediatric cardiology and cardiac surgery communities of the project to help ensure that the early work by the project pilot participants will spread to clinicians caring for children with cardiovascular disease. It is anticipated that this project will add to our understanding of care for this challenging group of children with hypoplastic left heart syndrome, identifying clinical care changes with the potential to lead to improvements in outcome. It will also introduce the field of pediatric cardiology to the science of collaborative quality improvement and assist in reducing clinical process variation and improving patient outcomes across centers. Finally, it will establish an ongoing network of pediatric cardiologists and their teams linked through a longitudinal data set and collaboration for improvement and research.
Integration of radiotherapy planning systems and radiotherapy treatment equipment: 11 years experience

Purpose: We have investigated the requirements, design, implementation, and operation of a computer-controlled medical accelerator with multileaf collimator (MLC), integrated with a radiation treatment-planning system (RTPS), and we report on the performance, benefits, and lessons learned from this experience. Methods and Materials: In 1984 the University of Washington installed a computer-controlled radiation therapy machine (the Clinical Neutron Therapy System, or CNTS) with a multileaf collimator. Since the beginning of operation the control system computer has been connected by commercially available network hardware and software to three generations of radiation treatment-planning systems. Semiautomated setup and completely computerized check and confirm were incorporated into the system from the beginning of clinical operation in 1984. The system cannot deliver a patient treatment without a computer-prepared treatment plan. Results: The CNTS has been in use for routine patient treatments for over 11 years. The cost of the network &%&ion and software was an insignificant fraction of the facility cost. Operation has been efficient and reliable. Of the 441 machine-related session reschedulings (out of 18,432 sessions total) during the past 9 years, only 20 were due to problems with data transfer between the RTPS and CNTS, associated primarily with two incidents. Close integration with the treatment-planning system allows complex treatments to be delivered. Dramatic evolution of the departmental treatment-planning system has not required any changes or redesign of either the accelerator control system or the network connection. Conclusions: Our experience shows that a large degree of automation is possible with reasonable effort, by using well-known software and hardware design strategies. The lessons we have learned from this can be carried over into photon therapy now that photon accelerators with MLC facilities are commercially available. 0 1997 Elsevier Science Inc.
Successional changes in plant species diversity and composition after clearcutting a Southern Appalachian watershed

Abstract Watershed 7, a southwest-facing watershed in the Coweeta Basin, western North Carolina, USA, was clearcut in 1977. Twenty-four permanent plots were inventoried in 1974 before cutting and in 1977, 1979, 1984, and 1993 after clearcutting. This study evaluates changes in species diversity during early succession after clearcutting and differences in overstory tree and ground flora response to disturbance by clearcutting and their interaction with previous disturbances and subsequent stand development. To quantify species diversity, we computed Shannon-Weaver's index of diversity (H′) and Pielou's evenness index (J′). Woody species diversity remained relatively stable; however, woody species richness increased in the cove-hardwoods and hardwood-pines, but remained relatively constant in the mixed-oak hardwoods. Although revegetation was rapid, forest composition has changed through succession. Opportunistic species, such as Liriodendron tulipifera, Robinia pseudoacacia, and Acer rubrum, increased in abundance, whereas Quercus velutina, Carya spp., and Q. rubra decreased. Ground flora diversity declined in the cove-hardwoods and mixed-oak hardwoods communities, but the decrease in the hardwood-pines was not significant. The abundance (g biomass m−2) of ground flora was much lower in 1993 than in 1984; 79% less in the cove-hardwoods, 90% less in the mixed-oak hardwoods, and 79% less in the hardwood-pines. Watershed 7 is apparently in a transition state between early and late successional species abundance. Early successional, shade-intolerant species, such as Erechtites, Solidago, Eupatorium, Panicum, and Aster, have declined, whereas late successional, shade-tolerant species, such as Viola, Galium, Sanguinaria, Uvularia, and Veratrum are not yet well established.
Awareness of Death among Children: Does a Life-Threatening Illness Alter the Process of Discovery?.

The authors review studies on death awareness among children who are healthy, chronically ill, and terminally ill. The review suggests that children with life-threatening diseases demonstrate increased understanding of death compared with children who are either healthy or chronically ill. In particular, children with terminal illness, especially during the end stage of their disease, show an advanced understanding of the death concepts of irreversibility and finality. In contrast, healthy and chronically ill children appear to require certain age, cognitive developmental level, or intelligence thresholds to understand these concepts. Possible explanations for the findings in this literature are discussed. The implications of death awareness research for counselors are used as a base for suggesting counseling strategies.
Addition of 1-methoxy-1-buten-3-yne to lactones: synthesis of substituted spiroketals☆

Abstract A method for the preparation of a variety of substituted spiroketals from lactones and 1-methoxy-1-buten-3-yne has been developed.
Recognition without perceptual identification: A measure of familiarity?

Previous work has shown that when items in a perceptual identification task are presented too quickly to identify, participants can still discriminate between studied and unstudied items. Such recognition without perceptual identification (RWPI) has been shown to occur in a variety of situations, including the false recognition of semantic associates of studied items. The present study investigated the utility of the RWPI paradigm for isolating instances of recognition that are familiarity based from those that are recollection based. Toward this end, the magnitude of the RWPI effect was compared in item versus associative recognition and in short versus long lists. The RWPI effect was larger in item than in associative recognition, and larger with short than with long study lists. These results are interpreted within the context of a dual-process approach to recognition and support the notion that RWPI taps familiarity-based recognition.
TESTIS HORMONE IN RELATION TO AGE

It is widely held that variations in the state of secondary sex characters in the male are due to variations in the amount of hormone produced by the testis, the transformations of puberty being regarded as a manifestation of an abrupt and great increase in testis hormone secretion and senile changes being attributed to diminution or cessation of this secretory activity. There are, however, few data on hormone production at different stages in the life cycle. Womack and Koch (1), without citing values for individual animals, report the highest concentration of testis hormone in fetal and young calves, with a progressive decrease thereafter. Funk, Harrow, and Lejwa (2) report less comb-growth promoting activity in the urine of old men than in the urine of young adults. Womack and Koch (3) state that no hormone occurs in the urine of boys under 10 years of age, whil after 10 years its concentration becomes as great as in adults. Buhler (4) also reports the absence of the hormone in urine before puberty, whi...
Effect of adenosine therapy at reperfusion on myocardial infarct size in dogs

Objectives The concept of lethal reperfusion injury in ischemic myocardium has been the subject of controversy. Adenosine administered during reperfusion has been reported to limit lethal reperfusion injury in several studies. On the contrary, it has been reported that cardioprotection may not be achieved with adenosine alone but may occur if adenosine is co-administered with lidocaine. Still other investigators have reported no beneficial effect of adenosine, given with or without lidocaine. If the positive reports are reproducible, they are important both because they provide evidence for the existence of reperfusion injury and establish a rationale for preventing it. Thus, the present study was done to determine if adenosine could limit lethal reperfusion injury in a canine model of regional myocardial ischemia and reperfusion, carefully controlled for baseline predictors of infarct size. Method Dogs ( n = 37) of either sex were subjected to 90 min of coronary occlusion followed by 3 h of reperfusion. Two groups of dogs received adenosine (150 μg/kg/min) intravenously for 155 min starting 5 min prior to the reperfusion. One treated group received adenosine only and a second group received adenosine plus lidocaine (2 mg/kg). Control dogs received a saline infusion. After 3 h of reflow, hearts were excised and infarct size was measured and expressed as a percentage of the ischemic area at risk (AAR). To control for variation in infarct size due to variation in collateral blood flow (CBF), infarct size among groups was compared using ANCOVA, using CBF as the independent variable and infarct size as the dependent variable. Results Transmural collateral blood flow and AAR were not significantly different between any of the groups. Mean infarct size (adjusted by ANCOVA) in control dogs ( n = 9) was 38.1 ± 5.3% of the AAR. Neither adenosine ( n = 9) nor adenosine plus lidocaine ( n = 7) significantly limited infarct size (35.6 ± 5.6% AAR and 38.1 ± 7.7% AAR, respectively; both P = NS). Conclusions Intravenous adenosine therapy (150 μg/kg/min) during reperfusion, whether administered alone or in dogs previously treated with lidocaine, did not limit infarct size after 90 min of regional ischemia in canine myocardium.
State Evaluation for Transformer Based on Grey System Theory

This paper proposes the modle based on Grey system theory to evaluate conditions of transformer. The model of unequal-interval GM (1,1) and GM(1,1) model including buffer operator are established to predict the values of gas dissolved in oil of transformer. According to the results of prediction,state of power transformer will be divided into five categories in order to propose corresponding repair strategy.The method is effective on providing support for transformer condition maintenance.The proposed method has been verified by the experimental data.
The New York Needle Trial: the politics of public health in the age of AIDS.

During the past 5 years, the exchange of sterile needles and syringes for dirty injecting equipment has gained increasing acceptance outside the United States as a potential means of reducing the transmission of the human immunodeficiency virus (HIV) among intravenous drug users. This article describes the controversy over attempts to establish a needle and syringe exchange scheme in New York City between 1985 and 1991. The response to a health crisis is used as an indicator of patterns of social and institutional practice. Advocates of needle exchanges had reached a stalemate with the promoters of law enforcement, and the strategic reformulation of the policy problem in terms of the research process seemed to offer a solution. The article discusses the practical limitations on designing and carrying out a controversial health promotion policy; the use (under constraint) of a restrictive research process to constitute--rather than simply to guide or monitor--public policy; and the potential ethical hazard...
A radiation-tolerant ring oscillator phase-locked loop in 0.13µm CMOS

Advanced CMOS technologies have demonstrated reduced sensitivity to radiation total-ionization-dose (TID) effect. However, the reduced device dimensions can significantly increase the circuit sensitivity to transient radiation effects. This paper presents a radiation-tolerant ring oscillator Phase-Locked Loop (PLL) designed in a commercial 0.13 µm CMOS process. The PLL is designed for radiation-tolerant high-speed serial link applications. It operates over a frequency range of 1.1 GHz to 4.4 GHz with an RMS jitter of 1.8 ps at 3.125 GHz. The phase frequency detector (PFD) and frequency divider (FD) are designed with a novel D-flip-flop (DFF) that is robust to single event radiation effects (SEEs). The voltage-controlled oscillator (VCO) is designed with two ring oscillators cross-coupled thus compensating each other with the radiation-induced transient currents. Each ring oscillator has its own control voltage driven by an independent charge pump and loop filter. The redundancy helps to mitigate radiation strikes on the VCO control voltage. Simulation results show that the proposed PLL demonstrates radiation immunity for critical charge values up to 250 fC and can recover quickly from radiation strikes on its sensitive nodes. The PLL operates under a 1.2 V power supply and consumes 40 mW of power.
Stability of carmethizole hydrochloride (NSC-602668), an experimental cytotoxic agent

Abstract The solution stability and degradation mechanism of Carmethizole HCl ( 1 , NSC-602668), an experimental anti-cancer drug, were studied. An apparent p K a value of 4.2 at 25°C and ionic strength = 0.15 M (NaCl) was determined for 1 by potentiometric titration. The degradation 1 in aqueous solution proceeds by two consecutive hydrolysis reactions of the bis-carbamate moieties at C4′ and C5′, with hydrolysis at C5′ hydrolyzing approximately 8 times faster than hydrolysis at C4′. The rates of degradation of 1 in aqueous solution were determined as a function of pH, temperature, buffer concentration, ionic strength, and co-solvent concentration. The pH of maximum stability was at pH 1 at 25°C. Analysis of the hydrolysis products by electron impact mass spectrometry showed that one 18 O atom was incorporated into the first degradation product, 2 , when the reaction was run in 18 O-enriched water. This is consistent with alkyl C-O bond cleavage rather than an addition-elimination reaction at a carbamate group. The entropy of activation ( ΔS ‡ ) was −6.71 ± 0.05 e.u.at pH 9.90, indicating a unimolecular mechanism. All observations were consistent with an SN1 mechanism.
The pre-Fermi natural reactor: A note on the periodic mode of operation

The isotopic compositions of xenon released from the Oklo reactor at temperatures below 1000°C are such that the abundances of131Xe,132Xe and134Xe relative to136Xe are markedly enhanced when compared to the relative fission yields from the thermal neutron-induced fission of235U. These anomalies can be attributed to the fact that131Xe,132Xe and134Xe have fairly long-lived precursors: 8.04-day131I, 78.2-hour132Te and 42-minute134Te, respectively. It is possible to determine the duration of the time when the reactor was turned off from the ratios of excess132Xe to excess134Xe in these anomalous xenon fractions released from the Oklo reactor. Calculations based on the available xenon isotope data that the time period during which the reactor was turned off was approximately 2 to 3 hours.
The electrical conductivity behavior of K2Pt(CN)4Br0.3 · 2.3H2O at high pressures

Abstract The mixed valence complex K2Pt(CN)4Br0.3 · 2.3H2O has been studied at pressures up to 100, 000 atm using X-ray and conductivity methods. The results of the conductivity measurements are interpreted in terms of the interatomic distance changes occurring in the solid under pressure and are discussed in the context of current theories regarding the electronic structure of this material.
KINETICS AND MECHANISM OF REDOX-COUPLED, LONG-RANGE PROTON TRANSFER IN AN IRON-SULFUR PROTEIN. INVESTIGATION BY FAST-SCAN PROTEIN-FILM VOLTAMMETRY

Fast-scan protein-film voltammetry has been used to study and deconvolute the kinetics of proton-coupled electron transfer to and from the [3Fe−4S] cluster in Azotobacter vinelandii Ferredoxin I (Av Fd I). This crystallographically defined 7Fe ferredoxin contains a [3Fe−4S] cluster which takes up a proton when in its reduced (0) state. Results conform to a model for stepwise electron and proton transfers. Electron transfer to the cluster drives its protonation, whereas the rate of reoxidation of [3Fe−4S]0-H+ is controlled by the rate of release of the proton. The cluster is buried and inaccessible to solvent water molecules; an aspartate (D15) is located on the protein surface but otherwise proton transfer occurs across an aprotic barrier. The D15N mutant, in which this aspartate is replaced by asparagine, has also been studied. Rate constants for proton transfer in each direction and the accompanying energetics (reduction potentials and interdependent pK values of the cluster and aspartate) have been det...
Effects of a sexual assault scenario on handgrip strength across the menstrual cycle

Abstract Fluctuations in handgrip strength and reaction time were examined across the menstrual cycle. For handgrip strength, there was an interaction between menstrual cycle phase and whether testing involved overtones of sexual assault. Women who were in the ovulatory phase and read a sexual assault scenario were the only ones that showed an increase in handgrip strength. These results are consistent with other evidence that women may have been selected during human evolution to behave in ways that reduce the likelihood of conception as a consequence of rape.
Baculovirus-Mediated Expression of Rat Liver CTP:Phosphocholine Cytidylyltransferase

Abstract We describe herein the expression and purification of milligram quantities of rat liver CTP:phosphocholine cytidylyltransferase in recombinant baculovirus-infected insect cells. The enzyme was purified by incorporating modifications to a previously published procedure (P. A. Weinhold and D. A. Feldman, 1992, in "Methods in Enzymology" (E. A. Dennis and II. E. Vance, Eds.), Vol. 209, pp. 248-258, Academic Press, San Diego, CA). Like cytidylyltransferase purified from rat liver, the purified recombinant cytidylyltransferase has the same molecular weight (42 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and reacts to antibodies generated against the N and C termini of rat liver cytidylyltransferase. In addition, like the purified rat liver enzyme, the recombinant cytidylyltransferase is activated by lipids. We also expressed rat liver cytidylyltransferase as a fusion protein with glutathione-S-transferase and with a thrombin cleavage site between the two enzymes for rapid isolation of cytidylyltransferase. Thrombin cleavage was, however, incomplete and prolonged exposure to thrombin resulted in the degradation of cytidylyltransferase itself.
Choosing appropriate techniques for socio-political forecasting

After defining scientific forecasting, the crucial role of assumptions in such forecasts is explicated. This is followed by a discussion of the representations upon which forecasting systems are based. Six variables are then introduced to capture differences in socio-political forecasting circumstances: level of detail, accuracy, agreement on problem representation, robustness-brittleness, number of variables and interdependencies, and disturbance. A categorization of forecasting approaches - expert based, Bayesian, extremal statistical, and rule based - is offered. These forecasting approaches are then cross-referenced with the forecasting circumstances to produce recommendations for choosing an appropriate forecasting technique in a given policy circumstance. Most examples in the article are drawn from the realm of foreign policy and international politics, and the cross-referencing section concentrates on foreign energy policy examples.
Influence of norepinephrine administration upon pituitary hormone secretion in normal men

This study has investigated the effects of 6.2, 12:5, 25, 50 and 100 ng/kg/min/60 min of NE infused to normal men. Blood samples were obtained every 10 min, before, during and after drug administration for 3 consecutive h. Plasma levels on NE, LH, FSH, PRL, and GH were measured in all samples. The administration of 12.5 ng/kg/min over 60 min of NE induced a significant increase (p< 0.001) in plasma NE levels (n = 5) from a mean (± SE) baseline of 239 ± 14 ng/Lto 706 ± 54 ng/L which peaked and plateaued at 40 min. The calculated area under the curve was 18562 ± 3537 ng/ L/h of NE and significantly higher (p < 0.001) than during the h before the infusion (2358 ± 780 ng/L/h). This increase in plasma NE correlated well with the rise in plasma LH which showed a steady increase from baseline of 7.4 ± 1.3 mlU/ml to a significant (p<0.05) peak of 11 ± 1.9 mlU/ml atthe end of the infusion. Furthermore, analysis of the area under the curve revealed a greater (p < 0.05) LH release during the NE infusion (180 ± 18 mlU/ml/h) than before the infusion (92 ± 17 mlU/ml/h). With the exception of the studies utilizing 12.5 ng/kg/min/60 min, all other doses of NE resulted in no significant and/or consistent changes in plasma concentration of LH, FSH, GH and PRL. Thus, the direct participation of NE in the control of LH secretion in humans seems to occur in a very narrow window.
Mixing of States Containing Heavy Quarks

I discuss the mixing of states containing heavy quarks with new quantum numbers. The mixing of the new states can be substantial in gauge theories with right-handed currents, even though direct neutral couplings conserve all flavors. Some experimental implications of the results are discussed.
Optical phonon spectra of GaP nanoparticles prepared by nanochemistry

Gallium phosphide (GaP) nanoparticles have been synthesized by colloidal nanochemistry with two different surfactants: trioctylphosphine oxide and dodecylamine. Transverse optical (bulk) and surface optical phonons associated with the GaP nanoparticles were observed and studied experimentally by infrared transmission spectroscopy of a solid dispersion of these nanoparticles in cesium iodide pellets. These vibrational properties of the nanoparticles were used to obtain information about the crystallinity and surface interactions. The crystallinity and the stoichiometry of the samples were also examined and characterized by transmission electron microscopy, electron diffraction, and energy dispersive x-ray spectroscopy.
Comparative effects of tetrodotoxin, lidocaine, and amiodarone on Vmax in guinea pig cardiac Purkinje and papillary muscle fibers.

Abstract 1. 1. Electrophysiological effects of three drugs (tetrodotoxin, lidocaine, and amiodarone), which are known to depress Na channels in cardiac tissues, were studied on isolated guinea pig Purkinje fibers, by means of microelectrode techniques, and compared the findings with their effects on the ventricular papillary muscle. 2. 2. Special attention was paid with regard to their effects on the maximum upstroke velocity ( V · max ) of action potentials. 3. 3. In Purkinje fibers, tetrodotoxin was the most inhibitory for V · max , then in descending order, amiodarone, and lidocaine. 4. 4. That is, half maximal inhibition (IC50) of V · max by tetrodotoxin, lidocaine and amiodarone was approximately 1.7 × 10−5M, 1.5 × 10−4M and 2.8 × 10−4M, respectively. 5. 5. As for papillary muscle, higher concentrations of the three drugs were needed to get similar potency. 6. 6. The relationships between the depression in the V · max and action potential duration are discussed in conjunction with their antiarrhythmic activities.
Comparison of different template structures for high quality and self-separation thick GaN growth

Two different template structures of dot air-bridges and nanorods were used for 300 µm GaN growth by hydride vapor phase epitaxy (HVPE). The selective growth of arrays of dot air-bridges and nanorods whose sidewalls coated with SiO 2 are identified and exploited to form a compliant layer to decouple the impact due to the different thermal expansion and lattice mismatch between 300 µm overgrown GaN layer and the host sapphire substrate. As the process temperature cooling down from 1050 °C to room temperature in HVPE system, the 300 μm freestanding GaN substrates were obtained by the self-separation. The dislocation density was estimated by both the etching pit density method and cathodoluminescence (CL). The dislocation densities of the freestanding bulk GaN were lower than 5×10 6 and 5×10 7 cm -2 for the template structure of dot air-bridges and nanorods structure, respectively.
Pollen Stratigraphy of Playa Lakes: ABSTRACT

Since the discovery 15 years ago by Sears and Clisby that the dry lakes (playa lakes) of western North America contain a rich fossil pollen record, Pleistocene specialists have hoped that a definitive chronology would be forthcoming from this largely unglaciated region. Such a chronology should indicate the number of pluvial episodes and the magnitude of each. The deepest drill cores should reveal whether the Pleistocene began with a "bang" or a "whimper." Though hopes for a continuous Pleistocene chronology go largely unrealized, the pollen record of the last glacio-pluvial maximum, the Wisconsin, is increasingly well known. It indicates a major shift in vegetation zones not once but several times during the C-14-datable part of the record. Among the areas studied to date are the San Augustin Plains, the Willcox Playa, Great Salt Lake Desert, and the Texas High Plains. Some control on the fossil pollen record can be gained from the modern pollen rain of "natural" plant communities in the southwest. Despite formidable problems of long-distance transport of certain pollen types it appears that the major vegetation zones have their own distinctive local pollen pool, End_Page 473------------------------------ making it possible to interpret Pleistocene vegetation history, at least in rough terms. The results are best illustrated in a Pleistocene full-glacial vegetation map. End_of_Article - Last_Page 474------------
Mean square error analysis of improved receivers for unipolar communications - Asymmetrically Clipped Optical OFDM

Recently, an improved receiving technique for Optical Wireless (OW) with Intensity Modulation and Direct Detection (IM-DD) communication systems, implementing Asymmetrically-Clipped Optical OFDM (ACO-OFDM) modulation, has been proposed. It uses the previously discarded (so called in the literature) “clipping noise” to generate an improved estimator for the transmitted signal, up to 3dB in the receiver performance, without a change in the modulated signal, and with negligible complexity increase at the receiver. In this work we analyze the performance of the improved receiver, as a function of the input SNR; find the optimal parameters of the proposed receiver; show a range of parameters that guarantee performance improvement over the regular receiver; and find a set of fixed parameters that give near optimal performance for all input SNR, thus establishing a simple receiver without the need to estimate the input SNR.
SURGICAL MANAGEMENT OF ECHINOCOCCAL CYSTS OF THE HEART AND PERICARDIUM.

Surgical treatment of a 27-year-old man with an echinococcal cyst of the heart is reported, illustrating some difficulties and problems manifested by this lesion. Twenty-seven other patients operated upon for cardiac hydatid disease are reviewed in tabular form. Symptomatology, diagnosis, and management of this rare cardiac lesion are reviewed.
Completeness of revascularization for multivessel coronary artery disease and its effect on one-year outcome: A report from the NHLBI Dynamic Registry

When percutaneous coronary intervention (PCI) is performed in patients with multivessel coronary disease, a targeted revascularization (TR) of diseased vessels is performed more often than complete revascularization (CR). We compared baseline characteristics and 1-year outcomes of patients undergoing TR by operator choice (n = 1,091), TR because CR was unachievable (n = 375), and CR (n = 315) in the National Heart, Lung, and Blood Institute (NHLBI) Dynamic Registry. Patients receiving TR because CR was unachievable were older, had more comorbidities, worse ejection fraction, less often received 2b/3a inhibitors and stents, and less frequently achieved complete angiographic success than either patients receiving TR by choice or CR. Despite these considerable differences, cumulative rates of 1-year mortality, the need for repeat PCI, or coronary bypass surgery were similar in patients who received CR, TR by choice, or TR because CR was unachievable. In multivariable models, after adjustment for clinical characteristics and propensity to receive CR, the hazard ratio for CR versus TR was 1.10 (95% CI: 0.58-2.10) for 1-year mortality; 0.89 (0.60-1.32) for repeat PCI, and 0.92 (0.66-1.29) for repeat PCI or coronary bypass surgery. In conclusion, despite the presence of more unfavorable characteristics, patients undergoing TR demonstrate 1-year outcomes equivalent to those having CR, supporting its continued use in selected patients.
Chemoenzymatic synthesis of a high-mannose-type N-glycopeptide analog with C-glycosidic linkage

Abstract A synthesis of the title compound by chemical synthesis of a GlcNAcCH 2 Asn containing peptide and enzymatic transfer of a Man 9 GlcNAc group to it was described.
Inhaled antisense oligonucleotide therapies: Inspiration and progress

Inhaled antisense oligonucleotides represent an emerging therapeutic approach for management of respiratory diseases. Although most attention has focused on systemic administration of antisense compounds, this class of agents is currently marketed for local therapy of ocular disease. The inhaled route provides excellent potency in animals due to direct delivery to the target tissue with good tolerability demonstrated in recent clinical trials. The stage is set for the new generation of chemically improved respired antisense oligonucleotides to offer new options for patients with pulmonary disorders.
The Language Demands of Science Reading in Middle School

The language used to construct knowledge, beliefs, and worldviews in school science is distinct from the social language that students use in their everyday ordinary life. This difference is a major source of reading difficulty for many students, especially struggling readers and English‐language learners. This article identifies some of the linguistic challenges involved in reading middle‐school science texts and suggests several teaching strategies to help students cope with these challenges. It is argued that explicit attention to the unique language of school science should be an integral part of science literacy pedagogy.
Regional simulations of the Faroe Bank Channel overflow in a level model

Abstract The work presented in this paper is part of an effort to understand and improve the representation of overflows in large scale, coarse resolution ocean climate models. To this end we developed a regional model of the Faroe Bank Channel overflow using the MITgcm (Massachusetts Institute of Technology General Circulation Model), a typical global ocean model using discrete levels as the vertical co-ordinate. In order to isolate the numerical diffusion resulting from the advection of tracers, the model is run without any turbulence closure schemes, without convective adjustment or any other physically based parameterization of mixing. Comparison between the model results and recent observations of the Faroe Bank Channel plume allows assessment of the model performance, including its ability to correctly represent the mixing and the downslope transport in the plume. It is found that at the highest resolution used in this paper (2.5 km – horizontal and 25 m – vertical) the structure of the modeled plume and the magnitude of the entrainment is comparable to the observed plume. The dependence of the mixing on various model parameters, such as vertical and horizontal resolution, vertical viscosity, drag coefficient and inflow forcing, is tested extensively. The numerical mixing in the model is found to be most sensitive to changes in the horizontal resolution, and to a lesser extent on vertical resolution and vertical viscosity. The inflow forcing and drag coefficient show only a very minor effect on the mixing. The results presented in the paper identify the shortcomings of the model at coarser resolutions which need to be addressed when attempting to represent such overflows realistically in large scale climate and ocean models.
Gaussian beams and their generalizations.

Boundary-value problems for the reduced wave equation that give rise to Gaussian and generalized Gaussian beams in paraxial regions are studied via complex ray geometrical optics. Expressions for the field valid both within and outside the paraxial region are obtained, and the results are compared with those given by paraxial wave optics and evanescent-wave theory.
A measurement of the beta-branching ratio of Lu176m

Abstract The β-branching ratio of 3.7 h Lu 176m to the 0 + (ground) and 2 + (88 keV) levels in Hf 176 has been measured by β-γ coincidence techniques using a Gerholm-type β-γ coincidence spectrometer. The intensities of the inner and ground state groups are 37±12% and 63±12%, respectively. Using a previously reported Q β − = 1314 keV, the experimental relative reduced transition probability calculated is 0.34 −0.08 +0.30 . Because the I π = 1 − for this isomer has been previously determined experimentally, the branching ratio establishes the K -quantum of the isomer as K = 0, assuming the validity of the K -intensity rules of the strong coupling model. The I π K =1−0 assignment of the isomer therefore indicates that Lu 176m has an anomalous K = 0 rotational band in which the odd spin band is displaced below the even spin band.
On stimulating productivity in the U.S.: The need to encourage innovation is broadly supported, and a program is sought

Technological innovation is the application of the industrial arts and sciences, along with the human intellect, to change the way society creates its goods and services, or the very nature of those goods and services. Despite the fact that technological innovation can secure large benefits for society, and that small businesses secure those benefits out of all proportion to their size, the rate of creation of small businesses in the United States has fallen dramatically over recent years. From 1964 to 1974, the number of new public issues for small high-technology companies dropped from $349 million to $6 million. Even more tragic is the fact that in the first half of 1975, there was not a single new issue for a small high-technology company.
Prenatal stress reduces estradiol-induced prolactin release in male and female rats

Abstract Prenatal stress is a potent disruptor of the normal course of sexual differentiation, affecting both males and females. In the present study, we wished to examine a sexually dimorphic endocrine response, estradiol (E2)-induced prolactin (Prl) release, in prenatally-stressed (P-S) males and females. Sprague-Dawley female rats were timed-mated ( + sperm=Day 1). From gestation days 15–22 one group of females was subjected to a thrice-daily regimen of heat and restraint stress (0830, 1230, and 1630 hr) consisting of placing the rats into a Plexiglas restraint tube over which were poised two 100 W floodlights. Control females remained undisturbed throughout pregnancy. At parturition all offspring were cross-fostered to untreated, recently-parturient dams and weaned at 25 days of age. Separate groups of P-S and Control males and females were gonadectomized and, for males, paired testes weights and body weights were recorded. Four days later the animals were implanted with Silastic capsules containing E2, and fitted with intra-atrial cannulae. The following day, blood samples were taken at 0900, 1300, 1500, and 1700 hr for a total of five days. Beginning with the 1700 hr sample on Day 2, and with the exception of the 1500 hr sample on Day 3, P-S males had significantly lower plasma Prl values than Control males through Day 4, and at the 1500 hr sample on Day 5. Moreover, at no point did P-S males exhibit a significant daily afternoon increase in Prl values, whereas Control males did so on Days 2 and 4. There was no difference between P-S and Control males in body weight, though P-S males had significantly heavier paired testes weights. Prenatally-stressed females were generally less responsive than Control females to the stimulatory effects of E2 on Prl release, in particular, the capacity to exhibit an afternoon Prl surge. The P-S and Control females did not differ at any time point on Days 1 and 2 of the sampling period. Nor were they different between 0900 and 1300 hr on Days 3 and 4, and 0900 hr on Day 5. P-S females exhibited significantly lower levels of Prl on the two late afternoon samples (1500–1700 hr) on Days 3–5, and had significantly higher levels at the 1300 hr sample on Day 5. These data demonstrate that prenatal stress affects the capacity of both males and females to secrete Prl in response to E2 and may indicate effects on central nervous system endocrinological functions complementary to behavioral deficits previously reported for P-S animals.
Perceptual discrimination of Thai tones by naive and experienced learners of Thai

This study investigated the ability to discriminate the middle and low tone contrasts in Thai by two groups of native English (NE) speakers and a control group of native Thai (NT) speakers. The first group was comprised of NE speakers who had no prior experience with Thai, whereas subjects in the second group were experienced learners of Thai (EE). The variables under investigation were experience with Thai, discrimination of open versus closed syllables, and the interstimulus interval (ISI) of the presentation (500 vs 1500 ms). The results obtained indicated that the NT group obtained higher discrimination scores than the NE or EE groups, the EE group obtained higher discrimination scores than the NE group, all three groups of subjects found open syllables to be more difficult to discriminate than closed syllables, and subjects in the EE group obtained higher discrimination scores for open syllables in the shorter than the longer ISI condition.
High sensitivity piezoresistive cantilever design and optimization for analyte-receptor binding

The mechanical design and optimization of piezoresistive cantilevers for biosensing applications is studied using finite element analysis. The change of relative resistivity of piezoresistive microcantilevers is analyzed in the presence of the chemical reaction at the receptor surface under the condition of oscillating flow. Chemo-mechanical binding forces have been analyzed in order to understand issues of saturation over the cantilever surface. Furthermore, the optimum design using finite element modeling is achieved by modifying the factors pertaining to the geometry of the microcantilevers under the condition of bio-binding. The introduction of stress concentration regions (SCRs) during cantilever fabrication has been discussed, which greatly enhances the detection sensitivity through increased surface stress. Finally, the optimum SCR modified 'C' piezocantilever system for biosensing is designed and the optimal parameters are set for high sensitivity.