cssi/SciSciGPT-SciSciNet huggingface dataset:
Echocardiography at the American Heart Association Scientific Sessions: an editorial perspective.

Echocardiography remains the primary imaging modality used by clinical cardiologists for investi­ gation of a wide range of heart abnormalities. It is considered a routine examination for pericardia!, val­ vular, congenital, and coronary heart disease. In an effort to assess the spectrum of abnormalities under investigation in echocardiography, a tabulation was made ofabstracts dealing with echocardiography and Doppler techniques from the American Heart As­ sociation Scientific Sessions, Anaheim, California, November 1987. The following is a brief synopsis of this tabulation and following it are a number of comments concerning several recent developments. The referenced abstracts are not meant to be a com­ plete tabulation but only to allow reference to specific points. Of the 2204 abstracts listed in Circulation (sup­ plement IV)/ 287 (13%) were at least in part based on echocardiographic studies. Although this per­ centage may not · reflect the utilization of echocar­ diography in clinical practice, this number of ab­ stracts in a scientific session relatively predominated by the basic sciences remains a respectable showing. Five continents and over 20 different countries were represented. The largest number of abstracts was not unexpectedly from the United States (192), with European countries contributing 45 (18 from West Germany). Japanese universities and medical centers contributed 28 abstracts, and 13 came from Canadian institutions. The type ofabstract presented had some geographic basis, with the majority of the transesophageal presentations originating in Euro­ pean countries and with Japanese investigators more often contributing work in Doppler techniques. As expected, the majority of the abstracts dealt with topics in adult cardiology. Table 1 outlines a crude breakdown of the types of studies reported.
Comparison of age-extended norms for the Wechsler Adult Intelligence Scale-Revised in patients with Alzheimer's disease

Recent studies (R. J. Ivnik et al., 1992; J. F. Malec et al., 1992; J. J. Ryan, A. M. Paolo, & T. M. Brungardt, 1990) have provided age-extended norms for the Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981). The current study compared IQ scores based on these newer age-extended norms in 216 elderly Alzheimer's disease patients. Results showed that when the norms from Ryan et al. were used, IQ scores were consistently the same as or higher than when WAIS-R manual norms were used. When the norms provided by Ivnik et al. and Malec et al. were used, IQ scores tended to be lower than WAIS-R manual norms for younger patients with more intellectual impairment
Operational Behavior of an Injection-Locked Quantum-Dash Fabry-Perot Laser at Zero-Detuning

The behavior of a zero-detuned injection-locked Quantum-Dash Fabry-Perot laser under varied injected field ratios is investigated theoretically and experimentally. A low slave laser linewidth enhancement factor is found to inhibit chaotic/Period-2 operation.
Alginate Hydrogels for Three-Dimensional Organ Culture of Ovaries and Oviducts

Ovarian cancer is the fifth leading cause of cancer deaths in women and has a 63% mortality rate in the United States(1). The cell type of origin for ovarian cancers is still in question and might be either the ovarian surface epithelium (OSE) or the distal epithelium of the fallopian tube fimbriae(2,3). Culturing the normal cells as a primary culture in vitro will enable scientists to model specific changes that might lead to ovarian cancer in the distinct epithelium, thereby definitively determining the cell type of origin. This will allow development of more accurate biomarkers, animal models with tissue-specific gene changes, and better prevention strategies targeted to this disease. Maintaining normal cells in alginate hydrogels promotes short term in vitro culture of cells in their three-dimensional context and permits introduction of plasmid DNA, siRNA, and small molecules. By culturing organs in pieces that are derived from strategic cuts using a scalpel, several cultures from a single organ can be generated, increasing the number of experiments from a single animal. These cuts model aspects of ovulation leading to proliferation of the OSE, which is associated with ovarian cancer formation. Cell types such as the OSE that do not grow well on plastic surfaces can be cultured using this method and facilitate investigation into normal cellular processes or the earliest events in cancer formation(4). Alginate hydrogels can be used to support the growth of many types of tissues(5). Alginate is a linear polysaccharide composed of repeating units of β-D-mannuronic acid and α-L-guluronic acid that can be crosslinked with calcium ions, resulting in a gentle gelling action that does not damage tissues(6,7). Like other three-dimensional cell culture matrices such as Matrigel, alginate provides mechanical support for tissues; however, proteins are not reactive with the alginate matrix, and therefore alginate functions as a synthetic extracellular matrix that does not initiate cell signaling(5). The alginate hydrogel floats in standard cell culture medium and supports the architecture of the tissue growth in vitro. A method is presented for the preparation, separation, and embedding of ovarian and oviductal organ pieces into alginate hydrogels, which can be maintained in culture for up to two weeks. The enzymatic release of cells for analysis of proteins and RNA samples from the organ culture is also described. Finally, the growth of primary cell types is possible without genetic immortalization from mice and permits investigators to use knockout and transgenic mice.
The Role of Theory and Experiment in Language Design--A 15 Year Perspective

This paper highlights a 15-year research effort during which the executable specification language SequenceL has been researched and developed. The paper covers early insights into how iterative control structures are used as well as advances involving simple and general semantics.
Are you enjoying globalization yet? The surprising implications for business

Purpose – Globalization is changing the nature of competition and value creation in ways more subtle and fundamental than simply cost. By incubating scores of new business models that can unseat established companies, globalization is creating opportunities for new value creation and highly profitable growth at the two ends of the value chain – new customer connections at one end and new models of innovation at the other. This article discusses globalization and the changing nature of competition and value creation.Design/methodology/approach – Provides a viewpoint of globalization and the changing nature of competition and value creation.Findings – For many companies, the most powerful moves will be to take advantage of university alliances and global talent sourcing. Every company today, large or small, has to draw the global map of the key talent pools for its business, whether that talent consists of software programmers, machinists, biotechnologists, materials scientists, cinematographers, financial ...
CO ADSORPTION AS A PROBE OF ACID SITES AND THE ELECTRIC FIELD IN ALKALINE EARTH EXCHANGED ZEOLITE BETA USING FT-IR AND AB INITIO QUANTUM CALCULATIONS

Fourier transform infrared (FT-IR) spectra were obtained for carbon monoxide adsorbed on a series of alkaline earth exchanged beta zeolites. A cation-dependent vibrational band was observed at 2184, 2190, 2195, and 2210 cm-1 for CO adsorbed on Ba-beta, Sr-beta, Ca-beta, and Mg-beta, respectively. Using the experimental CO vibrational frequencies, the calculated electric fields ranged from 7.3 V/nm (Ba-beta) to 12.9 V/nm (Mg-beta). A vibrational band at 2228 cm-1 was observed in all of the IR spectra and was assigned to CO adsorbed on Lewis acid sites. A shoulder observed at 2188 cm-1 in some of the infrared spectra was assigned to CO interacting with Bronsted acid sites. The FT-IR experimental studies were combined with ab initio calculations to understand the effect of the different alkaline earth cations on the observed vibrational frequencies. Model compounds M(OH)2−CO (where M = an alkaline earth cation) and Al(OH)3−CO were used in the calculations to approximate the zeolitic environment. The computat...
Characterization of muscarinic cholinergic receptors in the crab nervous system.

: The selective muscarinic antagonist L-[3H]-quinuclidinyl benzilate (L-[3H]QNB) binds reversibly and with high affinity (KD= 0.3 nM) to a single population (Bmax= 105 fmol/mg protein) of specific sites in nervous tissue of the crab Cancer magister. The binding site is stereoselective; (-)QNB is over 200 times more potent than (+)QNB as an inhibitor of specific L-[3H]QNB binding. The muscarinic antagonists scopolamine and atropine are over 10,000 times more potent inhibitors of L-[3H]QNB binding than the nicotinic antagonists deca-methonium and d-tubocurarine. The muscarinic agonists oxotremorine, pilocarpine, arecoline, and carbachol also compete effectively for the L-[3H]QNB binding site. This pharmacological profile strongly suggests the presence of classical muscarinic receptors in the crab nervous system. These receptors are localized to nervous tissue containing cell bodies and neuropil, whereas specific L-[3H]QNB binding is low or absent in peripheral nerve, skeletal muscle, and artery.
The political economy of agrarian reform in Yucatán, Mexico

Abstract Fundamental land tenure reform in Yucatan has been characterized by declining productivity in the henequen ejidos (collectives), and the Banco Rural — which supervises and finances the ejidos — has sustained chronic, burgeoning operational losses. Several related causes account for the economic failure of the Reforma Agraria : (1) the disruption of the spatial unity and organizational integrity of the expropriated agroindustrial estates, (2) the perverse incentive structure facing the ejidatarios , the presumed ‘owners’ of the collective ejidos , (3) the debilitating corruption that has characterized the official bank's management of the ejidos , (4) the primacy of the federal government's and the official party's political/ social goals in the state over economic/market considerations.
Synchronous expression of individual metacyclic variant surface glycoprotein genes in Trypanosoma brucei

One distinctive feature of the Trypanosoma brucei life cycle is the presence of two discrete populations that are based on differential expression of variant surface glycoproteins (VSGs). Both are adapted to the environmental pressures they face and more importantly, both contribute directly to transmission. Metacyclics in the tsetse fly enable transmission to a new mammalian host, whereas bloodstream trypanosomes must avoid immune destruction to the extent that sufficient numbers are available for transmission, when the insect vector takes a blood meal. At present, there are few investigations on the molecular aspects of parasite biology in the tsetse vector and specifically about the activation of metacyclic VSG gene expression. Here we used an established in vitro differentiation system based on the overexpression of the RNA-binding protein 6 (RBP6), to monitor two metacyclic VSGs (VSG 397 and VSG 653) during development from procyclics to infectious metacyclic forms. We observed that activation of these two mVSGs was simultaneous both at the transcript and protein level, and manifested by the appearance of only one of the mVSGs in individual cells.
Communication of Intentions in Agonistic Contexts By the Pigeon Guillemot, Cepphus Columba

This observational study of communication behavior of the pigeon guillemot (Cepphus columba) in agonistic contexts studied two questions: (1) What factors influence the outcome of interactions between male territory owners and intruders? and (2) Is information about the signaller's intention contained in signals? Pigeon guillemots nest in rock crevices which they defend against conspecifics. Intruders tend to visit single birds on territories as opposed to pairs or unoccupied territories. Male territory owners give a long (mean = 85 sec) series of whistled notes, the Hunch-whistle display, and enter the nest crevice when a female visits. Males also Hunch-whistle "spontaneously" and females approach, enter the nest, and appear to inspect the male's nest-site. Mutual Hunch-whistles usually involve male owners and male intruders, and tend to occur soon after a bird occupies a territory. The outcome of interactions between male territory owners and non-mate intruders was independent of the intruder's sex. Intruders retreated without escalation occurring in 51 % of cases and the owner attacked in 2 % of the cases. Fights involving both birds were rare and tended to occur early in the breeding season when both males had spent time on the territory in the previous week. No injuries were witnessed in over 600 aggressive interactions. Territory owners won 21 of 23 fights with male intruders. Size and age did not appear to contribute to fighting success. A pay-off asymmetry in favor of owners best explains the dominance of owners over intruders. Analysis of behavior sequences using a three-dimensional contingency table revealed that displays were significantly associated with different responses by recipients and with different subsequent behaviors by the signaller. The response also had an effect on the displayer's subsequent behavior. Flight by recipients decreased the probability of subsequent attack by signallers but other, less predictable forms of interaction between response and subequent behavior also occurred. Territory intruders flew after 43 % of the occurrences of the Neck-stretched display; no owner display preceded attack more than 14% of the time. Variation in the length and frequency of Hunch-whistle notes reflect changing probabilities that the signaller will sit, move, or attack. The owner/intruder dichotomy best explains which bird attacks/flies in an interaction. Variability in the bird's vocalization provides information about when flight or attack will occur. Differences in costs associated with attack versus flight may explain why flight is potentially more predictable than attack.
Cytokines in dementia of the Alzheimer's type (DAT): relevance to research and treatment

There is indirect evidence suggesting that some cytokines may be involved in the pathophysiology of dementia of the Alzheimer type (DAT). Measurement of proinflammatory cytokines in the biologic fluids and brain tissues of DAT patients have provided some support for such a role. However, these studies are limited in scope and have included a relatively small number of patients. Future studies are needed to elucidate the role of cytokines in the pathogenesis and treatment of DAT.
Response of a Macrotidal Estuary to Changes in Anthropogenic Mercury Loading between 1850 and 2000

Methylmercury (MeHg) bioaccumulation in marine food webs poses risks to fish-consuming populations and wildlife. Here we develop and test an estuarine mercury cycling model for a coastal embayment of the Bay of Fundy, Canada. Mass budget calculations reveal that MeHg fluxes into sediments from settling solids exceed losses from sediment-to-water diffusion and resuspension. Although measured methylation rates in benthic sediments are high, rapid demethylation results in negligible net in situ production of MeHg. These results suggest that inflowing fluvial and tidal waters, rather than coastal sediments, are the dominant MeHg sources for pelagic marine food webs in this region. Model simulations show water column MeHg concentrations peaked in the 1960s and declined by almost 40% by the year 2000. Water column MeHg concentrations respond rapidly to changes in mercury inputs, reaching 95% of steady state in approximately 2 months. Thus, MeHg concentrations in pelagic organisms can be expected to respond rapi...
Planar Platinum Metallacyclynes Containing One and Two Trialkyne Pockets

Efficient syntheses and characterization of a platinum metallacyclyne containing one cyclic enyne pocket (3), the first dinuclear platinum metallacyclyne containing two cyclic enyne pockets (4), and 2,2‘,6,6‘-tetraethynyltolan (2) are reported. Syntheses of 3 and 4 employ bidentate phosphines or cis-platinum starting materials and high dilution techniques to effect high yields.
Requirement for Positive Selection of γδ Receptor-Bearing T Cells

The alpha beta and gamma delta T cell receptors for antigen (TCR) delineate distinct T cell populations. TCR alpha beta-bearing thymocytes must be positively selected by binding of the TCR to major histocompatibility complex (MHC) molecules on thymic epithelium. To examine the requirement for positive selection of TCR gamma delta T cells, mice bearing a class I MHC-specific gamma delta transgene (Tg) were crossed to mice with disrupted beta 2 microglobulin (beta 2M) genes. The Tg+beta 2M- (class I MHC-) offspring had Tg+ thymocytes that did not proliferate to antigen or Tg-specific monoclonal antibody and few peripheral Tg+ cells. This is evidence for positive selection within the gamma delta T cell subset.
Effects of rapid changes in oxygen concentration on the respiration of carrot roots

Rates of CO2 production and O2 consumption from aged disks of carrot (Daucus carota L.) root tissues were measured for 4 h after they were transferred from 21% to 0, 1, 2, 4 or 8% O2 in gas mixtures. A transient peak in the rate of CO2 production started 5 to 7 min after transfer to 2% or lower O2 mixtures and peaked at 50 min. After the peaks in CO2 production from the 0, 1 and 2% O2 treatments and after the stable production from the 4 and 8% O2 treatments, the rate of CO2 production from all low O2 treatments started to decline at 50 min, reaching stable rates by 160 to 240 min. Concentrations of lactate and ethanol that were significantly higher than the 21% O2 controls had started to accumulate in disks between 10 and 50 min after exposure to atmospheres containing 2% or less O2. Production of CO2 started to increase 5 to 7 min after transfer to 0, 1 and 2% O2, while the initial decline and then rise in pH and the accumulation of ethanol did not occur until 30 min after the change in atmosphere. Ethanol accumulation paralleled the increase in pH; first at 0.4 μmol g−1 h−1 from 30 to 60 min as the pH shifted from 5.97 to 6.11, and then at 0.08 μmol g−1 h−1 from 60 to 100 min as the pH stablized around 6.12. The peak at 50 min in CO2 production roughly coincided with the shift from the rapid to the slow change in pH and ethanol accumulation.
Severe hypoxia produced by concomitant intoxication with sublethal doses of carbon monoxide and cyanide.

Abstract It has long been known that a number of tissue hypoxicants are generated in the fire scenario. However, until recently few investigators have undertaken to correlate smoke inhalation deaths with the simultaneous exposure to histoxic hypoxicants. Carbon monoxide and hydrogen cyanide are two histotoxic hypoxicants that are generated in nearly every fire. Prior studies performed in our laboratory have demonstrated that death can result from concomitant exposure to otherwise sublethal concentrations of carbon monoxide and cyanide. Since most smoke inhalation victims exhibit acid/base anomalies, we sought to investigate whether the death associated with simultaneous exposure to these two hypoxicants, at concentrations widely held to be nonlethal, could be explained by acid/base imbalances. Male ICR mice were exposed to 0.35% carbon monoxide immediately after having been injected ip with potassium cyanide solution, or were challenged with either agent alone. Animals challenged with cyanide or carbon monoxide alone demonstrated significant hypoxia. However, animals challenged with both agents demonstrated much greater hypoxia than could be explained by an additive effect alone. Controls demonstrated no alteration in acid/base homeostasis. Blood pH perturbations were found to be due to severe lactic acidosis coupled with inadequate respiratory compensation. Thus, it appears that the synergistic lethal effect of simultaneous administration of carbon monoxide and cyanide are related to a precipitous decrease in blood pH, the tissue hypoxia and its resulting complications.
Orientation of synaptic plasma membrane vesicles containing calcium pump and sodium-calcium exchange activities

Sidedness of synaptic plasma membrane vesicles isolated from brain synaptosomes has been assessed by two distinct experimental approaches: first, analysis of (Na+ + K+)-ATPase, Mg2+-ATPase, and (Ca2+ + Mg2+)-ATPase activities before and after permeabilization of vesicles; second, analysis of Ca2+ fluxes via the Na+/Ca2+ exchanger, before and after modification of an imposed Na+ gradient by penetrating or nonpenetrating Na+ channel-modifying drugs. 0.05% saponin, which completely permeabilizes the vesicles, increases digitoxigenin-sensitive (Na+ + K+)-ATPase, basal Mg2+-ATPase, and (Ca2+ + Mg2+)-ATPase activities by 51.0, 47.4, and 83.6%, respectively. Saponin increases only the Vmax of the latter activity, the Km for Ca2+ (0.13 microM; the same as that for Ca2+-pumping) being unaltered by saponin. An increment of 20.5% in the Vmax of (Ca2+ + Mg2+)-ATPase activity with 10 microM A23187, reveals that the enzyme activity in nonpermeabilized vesicles is limited by the formation of a Ca2+ gradient. Thus, the saponin-induced increment in (Ca2+ + Mg2+)-ATPase due only to exposure of occluded sites (as opposed to Ca2+ gradient dissipation) is actually 52%, which is similar to values for both other ATPases, and suggests that 32-35% of plasma membranes exist in an inverted orientation. Vesicle orientation was independently assessed by the differential actions of tetrodotoxin (a membrane impermeant blocker) and veratridine (a membrane permeant agonist) on Na+-channel opening measured indirectly by dissipation of an imposed Na+ gradient utilized to drive a large 45Ca2+ accumulation via the Na+/Ca2+ exchanger. Tetrodotoxin reverses 35-44% of veratridine-mediated Na+ gradient-dissipation, the relative membrane-permeability of the two channel modifiers, suggesting that 56-65% of sealed vesicles are inverted. The concurrence of these two independent measurements of vesicle orientation reinforces their validity.
Estimates of extreme sperm production: morphological and experimental evidence from reproductively promiscuous fairy-wrens (Malurus)

Abstract When females mate multiply, the competition among males for fertilizations occurs cryptically within the reproductive tract of the female. Under such sperm competition, the amount of spermatogenic tissue, the efficiency of sperm production and the capacity for sperm storage should all be under strong selection. Males of several species of fairy-wrens (Malurus) have been found to store large numbers of sperm for ejaculation, a suggested adaptation to male-biased sex ratios and high levels of reproductive promiscuity. In this study we examined the histology of testes of three species of fairy-wren: the splendid, Malurus splendens melanotus, variegated, M. lamberti assimilis, and white-winged fairy-wren, M. leucopterus leuconotus, as well as the quantity and quality (viability) of sperm in captive male splendid fairy-wrens to estimate the temporal pattern of sperm production and depletion. The daily rates of sperm production in all three species were high: 306×10 6 sperm / day for splendid, 125×10 6 sperm / day for variegated and 204×10 6 sperm / day for white-winged fairy-wrens, and the efficiency of sperm production (sperm per day per g of body mass) was several orders of magnitude greater than values reported for other domestic and wild species. For splendid fairy-wrens, the estimates of sperm production varied with the method used for estimation (range of estimates 306×10 6 –1367×10 6 sperm / day ). Splendid fairy-wren males held in captivity replenished their sperm reserves within 12 h, which is faster than that reported for most other species thus far. There was a negative correlation between length of sampling interval and the proportion of live sperm in ejaculate samples, indicating that males that copulate more frequently have higher-quality ejaculates. Together, both experimental and morphological estimates suggest that all three species of fairy-wren invest considerable energy in the production as well as the storage of massive numbers of sperm. Intra- and interspecific variation in the rates of sperm production is most likely linked to differences in the operational sex ratios of social groups and the opportunity for extragroup parentage.
Embryonic fibroblasts from Gpx4+/- mice: a novel model for studying the role of membrane peroxidation in biological processes.

Abstract A previous study using mice null for Gpx4 indicates that PHGPx plays a critical role in antioxidant defense and is essential for the survival of the mouse. In the present study, we further analyzed the stress response of MEFs (murine embryonic fibroblasts) derived from mice heterozygous for the Gpx4 gene (Gpx4+/− mice). MEFs from Gpx4+/− mice have a 50% reduction in PHGPx expression without any changes in the activities of other major antioxidant defense enzymes. Compared to MEFs from Gpx4+/+ mice, MEFs from Gpx4+/− mice were more sensitive to exposure to the oxidizing agent t-butyl hydroperoxide (t-BuOOH), and t-BuOOH exposure induced increased apoptosis in MEFs from Gpx4+/− mice. When cultured at low cell density, MEFs from Gpx4+/− mice also showed retarded growth under normal culture conditions (20% oxygen) that was reversed by culturing under low oxygen (2% oxygen). In addition, oxidative damage was increased in the MEFs from the Gpx4+/− mice, as indicated by increased levels of F2-isoprostanes and 8-oxo-2-deoxyguanosine in these cells. Our data demonstrate that MEFs from Gpx4+/− mice are more sensitive to oxidative stress because of reduced expression of PHGPx.
High-Stakes Volunteer Commitment: A Qualitative Analysis

This study examines the social network ties, motivations, and experiences of high-stakes volunteers (HSVs): individuals who fulfill long-term, consistent, and intense time commitments providing med...
CXC and CC Chemokines Form Mixed Heterodimers ASSOCIATION FREE ENERGIES FROM MOLECULAR DYNAMICS SIMULATIONS AND EXPERIMENTAL CORRELATIONS

CXC and CC chemokines are involved in numerous biological processes, and their function in situ may be significantly influenced by heterodimer formation, as was recently reported, for example, for CXC chemokines CXCL4/PF4 and CXCL8/IL8 that interact to form heterodimers that modulate chemotactic and cell proliferation activities. Here we used molecular dynamics simulations to determine relative association free energies (overall average and per residue) for homo- and heterodimer pairs of CXC (CXCL4/PF4, CXCL8/IL8, CXCL1/Gro-α, and CXCL7/NAP-2) and CC (CCL5/RANTES, CCL2/MCP-1, and CCL8/MCP-2) chemokines. Even though structural homology among monomer folds of all CXC and CC chemokines permits heterodimer assembly, our calculated association free energies depend upon the particular pair of chemokines in terms of the net electrostatic and nonelectrostatic forces involved, as well as (for CC/CXC mixed chemokines) the selection of dimer type (CC or CXC). These relative free energies indicate that association of some pairs of chemokines is more favorable than others. Our approach is validated by correlation of calculated and experimentally determined free energies. Results are discussed in terms of CXC and CC chemokine function and have significant biological implications.
The effect of bisulfite on the dehalogenation of 5-chloro-, 5-bromo-, and 5-iodouracil.

Abstract The 5-chloro-, bromo-, and iodo-analogs of uracil are dehalogenated in the presence of sodium bisulfite to yield 5,6 dihydrouracil-6-sulfonate as the final product. Under similar conditions, 5-fluorouracil adds bisulfite to yield 5-fluoro-5,6 dihydrouracil-6-sulfonate but is not dehalogenated. Ultraviolet absorption spectra of 5-bromouracil and 5-iodouracil reacting under pseudo first-order conditions with bisulfite indicate that dehalogenation proceeds via a pathway which has 5-halo-5,6-dihydrouracil-6-sulfonate and uracil as intermediates. In the case of 5-chlorouracil, the rate of bisulfite attack on the 6-position of the chlorouracil ring system is very slow relative to the rate of bisulfite addition to uracil. Hence, although dechlorination does occur, ultraviolet absorption spectra of reaction mixtures containing bisulfite and 5-chlorouracil do not reveal the uracil absorption peak observed with both 5-iodouracil and 5-bromouracil. Fluorine and proton nmr spectra indicate that bisulfite addition to 5-fluorouracil is stereoselective as is the case of bisulfite addition to uracil.
CHANGING SALES PATTERNS IN MAJOR AMERICAN METROPOLISES, 1963-1982

This study analyzes changing levels of retail sales (in constant dollars to control for inflation) between 1963 and 1982 in 17 American metropolises, in 39 major retail centers in outlying parts of those metropolises, and in the central business districts of those metropolises. At the metropolitan level, growth in retail sales was highly correlated with growth in population and personal incomes. Patterns of sales growth for the outlying major retail centers were more varied. The most successful major retail centers focused on large regional shopping centers and occupied favorable locations with respect to metropolitan transportation systems. The swift establishment of competing centers often meant that periods of rapid sales increases were brief for major retail centers, some of which also experienced significant changes in their retail mixes. Central business districts generally had slower sales-growth rates than outlying centers, although the widely varying situations of different downtowns were reflect...
Seasonal responses of avian communities to invasive bush honeysuckles ( Lonicera spp.)

Invasive bush honeysuckles, Lonicera spp., are widely viewed as undesirable; however, the effects of Lonicera spp. on native fauna are largely unknown. We investigated how breeding and overwintering bird communities respond to the presence of Lonicera spp. by comparing communities in forested areas with Lonicera spp. to those with a native shrub understory. The dense understory created by Lonicera spp. was associated with a change in the breeding bird community. We found large increases in the densities of understory bird species (e.g. northern cardinals) and decreases in select canopy species (e.g. eastern wood-pewees) in Lonicera spp. sites. In winter, we observed greater densities of frugivorous birds (e.g. American robins) likely due to the fruits that remain on Lonicera spp.; however, there was no difference in the community composition between sites with and without Lonicera spp. Given the widespread distribution of Lonicera spp., this invasive species may facilitate the population increase and range expansion of selected bird species. Many bird species appear to utilize Lonicera spp. for nesting and foraging; therefore, its removal should be accompanied by restoring native shrubs that provide needed resources.
Diluted magnetic semiconductors as a tool for wave-function mapping in semiconductor heterostructures

Abstract Conduction and valence band edges in diluted magnetic semiconductors (e.g., Zn 1 − x Mn x Se) undergo enormous Zeeman shifts when a magnetic field is applied, reaching values in excess of 100 meV at low temperatures. By performing magneto-optical studies on semiconductor heterostructures consisting of diluted magnetic and non-magnetic layers (e.g., a ZnMnSe/ZnSe superlattice), one can exploit the drastic differences in the Zeeman splitting occuring in different layers to pinpoint the localization in space of specific electronic states. In particular, we discuss the spatial localization of states whose energy exceeds the potential barriers. We illustrate this by the investigation of above-barrier excitons localized in the barriers of type-I ZnSe/ZnMnSe superlattices, and of type-I (spatially direct) excitons in ZnTe/CdMnSe and ZnMnTe/CdSe type-II superlattices. We also discuss quasi-localization of states in a single barrier .
Conformational analysis of furanose rings with PSEUROT: parametrization for rings possessing the arabino, lyxo, ribo, and xylo stereochemistry and application to arabinofuranosides.

The solution conformation of a furanose ring can be assessed through PSEUROT analysis of three-bond 1H−1H coupling constants (3JHH) of the ring hydrogens. For each coupling constant, PSEUROT requires two parameters, A and B, which are used to translate the H−C−C−H dihedral angle predicted from the 3JHH into an endocyclic torsion angle from which the identity of the conformers can be determined. In this paper, we have used density functional theory methods to generate a family of envelope conformers for methyl furanosides 1−8. From these structures, A and B were calculated for each H−C−C−H fragment. In turn, the values of these parameters for the arabinofuranose ring were used in PSEUROT calculations to determine the conformers populated by monosaccharides 1 and 2 as well as the furanose rings in oligosaccharides 9−15. The results of these analyses are consistent with the low-energy conformers identified from previous computational and X-ray crystallographic studies of 1 and 2.
Disulfide Cross-Linked Hyaluronan Hydrogels

A new disulfide cross-linking strategy was developed to prepare hyaluronic acid (HA) hydrogel from thiol-modified HA. First, dithiobis(propanoic dihydrazide) (DTP) and dithiobis(butyric dihydrazide) (DTB) were synthesized and then coupled to HA with carbodiimide chemistry. Next, disulfide bonds of the initially formed gel were reduced using dithiothreitol (DTT) to give, after exhaustive dialysis, the corresponding thiol-modified macromolecular derivatives HA-DTPH and HA-DTBH. The degree of substitution of HA-DTPH and HA-DTBH could be controlled from 20% to 70% of available glucuronate carboxylic acid groups. The pK(a) values of the HA-thiol derivatives were determined spectrophotometrically to be pK(a) = 8.87 (HA-DTPH) and pK(a) = 9.01 (HA-DTBH). The thiol groups could be oxidized in air to reform disulfide linkages, which resulted in HA-DTPH and HA-DTBH hydrogel films. Further oxidation of these hydrogels with dilute H(2)O(2) created additional cross-links and afforded poorly swellable films. The disulfide cross-linking was reversible, and films could be again reduced to sols with DTT. Release of blue dextran from cross-linked films was used as a model for drug release. The rapid gelation of the HA-DTPH solution under physiological conditions was also achieved, which demonstrated the capacity for in situ cell encapsulation. Thus, L-929 murine fibroblasts were encapsulated in HA-DTPH hydrogel; these cells remained viable and proliferated during 3 days of culture in vitro.
Group Membership and Preference for Information about Others

This experiment tested the hypothesis that preference for information about persons is affected by the structure of the social environment. Subjects were either categorized into one of two competitive groups, one of two noncompetitive groups, a single group, or not assigned to a group at all. Each subject ranked his preference for seeing information concerning the similarity or dissimilarity of other persons' attitudes to his own. Subjects in the ingroup/outgroup conditions preferred information indicating similarity with the ingroup and dissimilarity with the outgroup. Subjects who were either all members of a single group or who were not categorized into a group expressed no preference regarding information about others.
Disturb mechanisms in coupled-film bulk memory elements

Performance of magnetic film memory arrays is limited by various disturb mechanisms that can completely erode written information if the array design inadequately provides for process variations, strip line attenuation, power supply variations, etc. This paper reports on several particularly relevant disturb mechanisms in coupled-film closed-easy-axis (CFCEA) arrays [1] intended for large capacity NDRO multiple-write bulk memory application. Two new design guidelines for densities \gsim 25 000 bit/in2are presented: 1) minimization of creep sensitivity to alternating interrogate and bit disturbs and 2) prevention of the formation of uncoupled interbit domains. Both can be achieved by mismatching the effective coercive fields of the coupled films in the same ratio as the applied easy-axis fields.
Rapid manual sequencing of multiple peptide samples in a nitrogen chamber.

Abstract Automatic protein sequenators are very expensive. Most laboratories must rely on slower manual methods. This paper describes an inexpensive nitrogen chamber in which multiple peptide samples may be sequenced manually and yet rapidly. The nitrogen environment keeps samples free from oxygen, water vapor, and dust. A complete, simple procedure for degrading peptides is also included. From six to twelve peptide samples may be degraded through one cycle of Edman degradation in a single morning. Several pieces of new equipment and procedures are described which simplify the manipulations involved in protein sequencing.
Apelin-13 inhibits large-conductance Ca2+-activated K+ channels in cerebral artery smooth muscle cells via a PI3-kinase dependent mechanism.

Apelin-13 causes vasoconstriction by acting directly on APJ receptors in vascular smooth muscle (VSM) cells; however, the ionic mechanisms underlying this action at the cellular level remain unclear. Large-conductance Ca2+-activated K+ (BKCa) channels in VSM cells are critical regulators of membrane potential and vascular tone. In the present study, we examined the effect of apelin-13 on BKCa channel activity in VSM cells, freshly isolated from rat middle cerebral arteries. In whole-cell patch clamp mode, apelin-13 (0.001-1 μM) caused concentration-dependent inhibition of BKCa in VSM cells. Apelin-13 (0.1 µM) significantly decreased BKCa current density from 71.25±8.14 pA/pF to 44.52±7.10 pA/pF (n=14 cells, P<0.05). This inhibitory effect of apelin-13 was confirmed by single channel recording in cell-attached patches, in which extracellular application of apelin-13 (0.1 µM) decreased the open-state probability (NPo) of BKCa channels in freshly isolated VSM cells. However, in inside-out patches, extracellular application of apelin-13 (0.1µM) did not alter the NPo of BKCa channels, suggesting that the inhibitory effect of apelin-13 on BKCa is not mediated by a direct action on BKCa. In whole cell patches, pretreatment of VSM cells with LY-294002, a PI3-kinase inhibitor, markedly attenuated the apelin-13-induced decrease in BKCa current density. In addition, treatment of arteries with apelin-13 (0.1 µM) significantly increased the ratio of phosphorylated-Akt/total Akt, indicating that apelin-13 significantly increases PI3-kinase activity. Taken together, the data suggest that apelin-13 inhibits BKCa channel via a PI3-kinase-dependent signaling pathway in cerebral artery VSM cells, which may contribute to its regulatory action in the control of vascular tone.
Recent Wyoming temperature trends, their drivers, and impacts in a 14,000-year context

Wyoming provides more fossil fuels to the remainder of the United States than any other state or country, and its citizens remain skeptical of anthropogenic influences on their climate. However, much of the state including Yellowstone National Park and the headwaters of several major river systems, may have already been affected by rising temperatures. This paper examines the historic climate record from Wyoming in the context of ∼14,000-year temperature reconstructions based on fossil pollen data. The analysis shows that 24 of 30 U.S. Historical Climatology Network records from the state show an increase in the frequency of unusually warm years since 1978. Statewide temperatures have included 15 years (50%) from 1978 to 2007 that were greater than 1σ above the mean annual temperature for 1895–1978. The frequent warm years coincide with a reduction in the frequency of extremely low ( 1°C) is greater than any time in the past 6,000 years. Recent temperatures have become as high as those experienced from 11,000 to 6,000 years ago when summer insolation was >6% higher than today and when regional ecosystems experienced frequent severe disturbances.
Identification of Phosphorylation Sites within the Signaling Adaptor APPL1 by Mass Spectrometry

APPL1 is a membrane-associated adaptor protein implicated in various cellular processes, including apoptosis, proliferation, and survival. Although there is increasing interest in the biological roles as well as the protein and membrane interactions of APPL1, a comprehensive phosphorylation profile has not been generated. In this study, we use mass spectrometry (MS) to identify 13 phosphorylated residues within APPL1. By using multiple proteases (trypsin, chymotrypsin, and Glu C) and replicate experiments of linear ion trap (LTQ) MS and LTQ-Orbitrap-MS, a combined sequence coverage of 99.6% is achieved. Four of the identified sites are located in important functional domains, suggesting a potential role in regulating APPL1. One of these sites is within the BAR domain, two cluster near the edge of the PH domain, and one is located within the PTB domain. These phosphorylation sites may control APPL1 function by regulating the ability of APPL1 domains to interact with other proteins and membranes.
Chemical informatics and target identification in a zebrafish phenotypic screen

Target identification is a core challenge in chemical genetics. Here we use chemical similarity to computationally predict the targets of 586 compounds that were active in a zebrafish behavioral assay. Among 20 predictions tested, 11 compounds had activities ranging from 1 nM to 10,000 nM on the predicted targets. The roles of two of these targets were tested in the original zebrafish phenotype. Prediction of targets from chemotype is rapid and may be generally applicable.
Establishing concrete cracking strength interval using possibility theory with an application to predict the possible reinforced concrete deflection interval

Concrete cracking is a challenging and uncertain design criterion that significantly affects our ability to predict the serviceability of reinforced concrete (RC) structures. It is evident that the concrete cracking strength depends on the test method, such as flexural strength, splitting tensile strength and direct tension. Moreover, prediction models proposed by design codes have wide variation. The uncertainty of the cracking strength determined experimentally or numerically reduces confidence in serviceability limit state design when compared with strength limit state design. However, this uncertainty cannot be claimed as a random uncertainty but rather as an epistemic uncertainty. Intervals can be used to describe this uncertainty using possibility theory, a mathematical framework to represent a kind of epistemic uncertainty known as non-specificity. A methodology is introduced here to establish a concrete cracking strength interval. A case study to use this cracking strength interval to predict an RC deflection interval is presented.
The science of spinal motion palpation: a review and update with implications for assessment and intervention.

Spinal motion palpation (SMP) is a standard component of a manual therapy examination despite questionable reliability. The present research is inconclusive as to the relevance of the findings from SMP, with respect to the patient’s pain complaints. Differences in the testing methods and interpretation of spinal mobility testing are problematic. If SMP is to be a meaningful component of a spinal examination, the methods for testing and interpretation must be carefully scrutinized. The intent of this narrative review is to facilitate a better understanding of how SMP should provide the examiner with relevant information for assessment and treatment of patients with spinal pain disorders. The concept of just noticeable difference is presented and applied to SMP as a suggestion for determining the neutral zone behavior of a spinal segment. In addition, the use of a lighter, or more passive receptive palpation technique, is considered as a means for increasing tactile discrimination of spinal movement behavior. Further understanding of the scientific basis of testing SMP may improve intra- and inter-examiner reliability. The significance of the findings from SMP should be considered in context of the patient’s functional problem. Methodological changes may be indicated for the performance of SMP techniques, such as central posterior-anterior (PA) pressure and passive intervertebral motion tests, in order to improve reliability. Instructors of manual therapy involved in teaching SMP should be knowledgeable of the neurophysiological processes of touch sensation so as to best advise students in the application of the various testing techniques.
Comparative studies of thyroxine binding proteins in turtle plasma using column chromatography

Thyroxine (T4) binding proteins in turtle plasma were compared with those of various mammalian and nonmammalian (fish, birds) species using gel filtration chromatography (Bio-Gel). High-affinity T4 binding was observed in all mammals studied, in the chicken, and in one species of turtle, Trachemys scripta. This high affinity T4 binding protein (TBP) appears to be the major component of T4 transport in the turtle; selective removal of this TBP greatly diminished binding activity in T. scripta plasma. In all other nonmammalian species studied (including other turtles), T4 binding appeared to be associated primarily with relatively low affinity components such as albumin. Albumin concentrations in turtle (T. scripta, and Chelydra serpentina) plasmas were examined by measurement of dry weight, protein assay (Bradford), radioimmunoassay, and electrophoretic densitometry. While C. serpentina may have total protein concentrations approaching that of human plasma, albumin content in both turtles was estimated at about 3-4 mg/ml, less than 10% that of human plasma albumin; larger molecular weight components that do not bind T4 comprise a greater proportion of turtle plasma protein. Additionally, purified T. scripta albumin exhibits lower T4 binding than does human albumin; binding to turtle albumin is also reduced by fatty acids. Taken together, these results indicate a lesser role for albumin in plasma T4 binding in T. scripta than in humans, and, thus, a larger role for the T4 binding protein, TBP. Other turtles lacking a TBP may rely wholly on low affinity albumin binding that also has a lower capacity than that in mammals.
A 73-Year-Old Man With Symptomatic Benign Prostatic Hyperplasia

Dr Parker: Mr B is a 73-year-old man who has had "prostate trouble" for several years. A former government employee, he lives in a suburb of Boston with his wife and daughter, and is covered by Medicare. He sees Dr N at a primary care practice at the Beth Israel Deaconess Medical Center. On a routine physical examination in 1993, he was noted to have a "firm" large prostate with a possible right prostatic nodule. At that time, he had no urinary symptoms. A prostate-specific antigen (PSA) level was 1.4 ng/mL. By the time of his urologic evaluation in early 1994, Mr B was complaining of nocturia every hour. Six biopsy specimens of the prostate were negative for malignancy, and the results of an ultrasound of the prostate were normal. Postbiopsy prostatitis was treated with a 6-week course of ciprofloxacin. Doxazosin (1 mg at bed-time) was prescribed to help alleviate