cssi/SciSciGPT-SciSciNet huggingface dataset:
The effect of actual and imaginary handgrip on postural stability during different balance conditions

The stabilizing effect of holding an object on upright posture has been demonstrated in a variety of settings. The mechanism of this effect is unknown but could be attributed to either additional sensorimotor activity triggered by a hand contact or cognitive efforts related to performance of a supra-postural task. A potential mechanism was investigated by comparing postural stability in young healthy individuals while gripping a custom instrumented wooden stick with a 5N force and while imagining holding the same stick in the hand. Twenty subjects were tested during three standing balance conditions: on a stationary surface, on a freely moving rockerboard, and with an unexpected perturbation of 10° forward rockerboard tipping. Postural stability was evaluated as velocity of the center of mass (COM) and center of pressure (COP) compared across all experimental conditions. COM and COP velocities were equally reduced when subjects gripped the stick and imagined gripping while standing stationary and on the rockerboard. When perturbed, subjects failed to show any postural stability improvements regardless of handgrip task. Results indicate a stabilizing effect of focusing attention on motor task performance. This cognitive strategy does not appear to contribute any additional stabilization when subjects are perturbed. This study adds to the current understanding of postural stabilization strategies.
Cell Cycle-Dependent Localization of Voltage-Dependent Calcium Channels and the Mitotic Apparatus in a Neuroendocrine Cell Line(AtT-20)

Changes in intracellular calcium are necessary for the successful progression of mitosis in many cells. Both elevation and reduction in intracellular calcium can disrupt mitosis by mechanisms that remain ill defined. In this study we explore the role of transmembrane voltage-gated calcium channels (CaV channels) as regulators of mitosis in the mouse corticotroph cell line (AtT-20). We report that the nifedipine-sensitive isoform CaV1.2 is localized to the “poleward side” of kinetechores during metaphase and at the midbody during cytokinesis. A second nifedipine-sensitive isoform, CaV1.3, is present at the mid-spindle zone in telophase, but is also seen at the midbody. Nifedipine reduces the rate of cell proliferation, and, utilizing time-lapse microscopy, we show that this is due to a block at the prometaphase stage of the cell cycle. Using Fluo-4 we detect calcium fluxes at sites corresponding to the mid-spindle zone and the midbody region. Another calcium dye, Fura PE3/AM, causes an inhibition of mitosis prior to anaphase that we attribute to a chelation of intracellular calcium. Our results demonstrate a novel, isoform-specific localization of CaV1 channels during cell division and suggest a possible role for these channels in the calcium-dependent events underlying mitotic progression in pituitary corticotrophs.
Evidence that central nervous system depression by 1,4-butanediol is mediated through a metabolite, gamma-hydroxybutyrate

Abstract Gas chromatographic analysis of blood and brain extracts from rats anesthetized with 1,4-butanediol (BD) revealed that BD was metabolized to γ-hydroxybutyrate (GHB), since the latter compound was found in both blood and brain. Further, there appeared to be a correlation between the brain concentration of GHB and the “sleep” induced by BD. (β-hydroxybutyrate, a known antagonist of GHB-induced “sleep” was found also to antagonize BD-induced “sleep” as well as to cause a reduction in the brain concentration of GHB. This evidence is taken to support the view that GHB is the active metabolite involved in the production of the “sleep” induced by BD.
EXITING A BUILDING: AN INFORMAL LOOK

Dur~ng a recent study conducted to provide some insight into the practice of business students m holhng doors open for those behind them when entering or exiting a building (I), it was noted that many seemed to avail themselves of the path of least resistance, using, if available. an ooen rather than a closed door. , . To gather better understanding of this impression, an inquiry was conducted in the summer of 1989 at the same large business school which is located in an urban setting in the Northeast. Using a convenience sample, notation was made of the door preferences of those exiting a building through a doorway consisting of four inner and four outer self-dosing doors. During the observation periods, one of the two center outer doon was restrained in the open position: the balance of the outer doors, and all of the inner doors, were left in their normally closed position. A total of 64 unobtrusive citings of 10 min. each were made, at varying times between the houn of 0900 and 1700, Mondays through Thursdays. While double counting was possible, it was felt that the volume of traffic, the occurrence of varvina situations, and the dispersion of . observation times minimized the probability of occurrence. A total of 819 instances were observed. AU things being equal-there being no waiting he for any door-about 7 out of 10 people opted to exit via the open door. When clustering built up around the open door, generally approximately two to three people, subsequent departees seemed to choose one of the closed doors. Differences between women and men, day of the week, time of day, and prevailing weather conditions did not appear to be marked. The only weather-related effect appeared to be a slowing of the flow of traffic when conditions outside were inclement: in particular, heavy rain. Recognizing the limitations of the method, the intrinsic subjectivity involved in the observations, the presence of local cultural biasing, and the inherent restraint on replication of the work, the results seem to suggest that the convenience of not having to open a door is valued by a sizable number of people. However, there appears to be an indifference point, measured in terms of the length of the que: if it is too long, the potential loss in time seems to become the determinant, and a closed door is used. Why people choose to exit a building via an open, rather than closed, door may well be due to a number of reasons, such as: desire to conserve personal energy, wish to evade the risk of selecting a door which is inoperable, being tired, or desire to avoid possible injury when manipulating a door. While the "why" is of interest, possibly of more interest is that there appears to be a point at which saving time seems to become the overriding situational consideration. As the saving is relatively small, perhaps a few seconds at the most, it is interesting to ponder what makes it so valued, and how it is subsequently used-or, it could just simply be a patience issue.
A proof of Shelah's partition theorem

A self contained proof of Shelah's theorem is presented: If μ is a strong limit singular cardinal of uncountable cofinality and 2μ > μ+ then\(\left( {\begin{array}{*{20}c} {\mu ^ + } \\ \mu \\ \end{array} } \right) \to \left( {\begin{array}{*{20}c} {\mu ^ + } \\ {\mu + 1} \\ \end{array} } \right)_{< cf\mu } \).
Saturated mono-unsaturated long-chain hydrocarbon profiles of sweet oranges

Abstract Three varieties of midseason oranges, viz. Jaffa, Homosassa and Queen, were examined for their saturated and mono-unsaturated hydrocarbon composition in juice sacs. Hydrocarbons were isolated by lipid extraction of the juice sac powders followed by column, thin-layer and AgNO 3 -TLC. After hydrogenation, the mono-unsaturated fraction and the saturated fraction were analyzed by GC. In the saturated fraction, the dominant linear hydrocarbon was C 23 while C 25 predominated in the monoene fraction. iso - And anteiso -branched hydrocarbons comprised between 53 and 63 % of the saturated fraction and only 20–26 % of the monoene fraction. Queen differed from Homosassa and Jaffa in the accumulation of higher percentages of saturated iso - and anteiso -branched hydrocarbons and conversely, showed lower percentages for these branched structures in the monoene fraction. Based on the total relative percentages of the three isomeric hydrocarbons, Homosassa could not be differentiated from Jaffa. The overall profiles for these two oranges, however. showed noticeable differences.
An overview of the results of the EPIC trial

The Evaluation of 7E3 for the Prevention of Ischaemic Complications (EPIC) trial assessed the use of abciximab in the treatment of patients at high risk undergoing percutaneous revascularization procedures. Abciximab (c7E3) is a chimeric monoclonal antibody targeted to block the glycoprotein IIb/IIIa receptor on the surface of the platelet; this receptor is believed to be the final common pathway of platelet aggregation. Administered at the time of angioplasty or directional coronary atherectomy, abciximab had a beneficial effect in the population studied, which included patients considered to be at high risk from complications of the procedure, based on the presence of acute or recent myocardial infarction, severe unstable angina or adverse coronary morphological characteristics. Abciximab reduced the risk of the primary endpoint at 30 days (death, myocardial infarction, repeat angioplasty or bypass surgery for recurrent ischaemia, balloon pump or stent insertion for ischaemia) by 35%: from 12.8% in the placebo group to 8.3% in patients treated with abciximab bolus and infusion. This trend was observed as a whole and in each component of the primary endpoint. At 6 months follow-up, the effect of the treatment was modestly enhanced beyond 30 days. A variety of substudies have documented substantial evidence of treatment benefit in patients with acute myocardial infarction and unstable angina. Non-fatal infarction, observed as beyond that normally expected in other studies with directional coronary atherectomy, was not above normal in patients treated with abciximab, and there was evidence of a treatment benefit in the elderly, although more information would be helpful in patients over the age of 70. The substantial site-to-site variability indicates that standardization of percutaneous revascularization could enhance the benefit of abciximab, while reducing bleeding complications.
Re-Mediating Second Language Acquisition: A Sociocultural Perspective for Language Development

This article provides a cultural-historical (CHAT) analysis of the practices used by an effective teacher of Latino/a children previously classified as “underachieving” and “beginning/novice” English Language Learners. Although the teacher would not describe her practices in strict CHAT, or sociocultural theory (SCT) terms, our analysis shows that teaching practices in this classroom are better understood using a SCT model rather than more prevalent second language acquisition (SLA) models that dominate the field of bilingual/English as a Second Language education. We describe the fundamental limitations of SLA assumptions about learners vis-a-vis a SCT perspective and use classroom and case study data to illustrate how a CHAT perspective illuminates this teacher's practices. From a CHAT perspective, teaching and learning are socially reorganized around the mediation of dynamic learner identities and include shifts in expert–novice status, dialogic interactions, and the use of innovative mediational tools...
Water Based Silicone Elastomer Controlled Release Tablet Film Coating III - Drug Release Mechanisms

AbstractThe release of potassium chloride from polyethylene glycol-silicone elastomer coated tablets was achieved by the diffusion through water-filled pores formed in the hydrated coating and the osmotic pumping generated by the saturated salt solution. The relative contribution of these two mechanisms to the overall drug release rate was shown to be a function of the polyethylene glycol loading in the coating. As the polyethylene glycol loading level increased, the transpore diffusion became the predominant release mechanism. The capability of the polyethylene glycol-silicone elastomer coatings to provide controlled release for therapeutic agents of different water solubilities and dose levels was also demonstrated. Both the rate and extent of release of the active ingredients could be altered by the type of diluent used in the tablet matrix
Stochastic developmental variation in the ratio of allelic rDNAs among newly differentiated, heterozygous macronuclei of Tetrahymena thermophila.

Ciliates possess nuclear dimorphism, i.e., they carry two structurally and functionally differentiated types of nuclei. The micronucleus and macronucleus serve as the germline and somatic nuclei, respectively, of the cell. The macronucleus differentiates from a mitotic sister of the micronucleus once per life cycle. Macronuclear differentiation is accompanied by a developmentally programmed set of DNA rearrangements, including chromosome fragmentation, telomere addition, and amplification. Given the diploidy of the MAC anlage, are both homologous copies of a chromosome processed and amplified equally and simultaneously in an individual differentiating MAC? We have approached this question for the case of the rDNA, exploiting previously identified DNA polymorphisms and the sensitivity of PCR. We determined allelic ratios in individual caryonide cells, i.e., the cells carrying the primary products of MAC differentiation, prior to the first division of the newly differentiated MAC. We observed stochastic variability in allelic ratios among caryonides that start with genetically identical heterozygous MACs. Either rDNA type can be in the majority. Appropriate controls make it unlikely that the ratios observed were significantly affected by variation in the assay itself. The variability may well result from the statistical variation associated with the relative timing of individual biochemical events initiating the processing and/or amplification of a few rDNA precursor molecules, presumably 4–8 at the most, in a MAC anlage. In addition to this stochastic variability, we observed a small but distinct bias in favor of the C3 rDNA. Thus the replication advantage of C3 relative to B rDNA in heterozygous MACs, previously detected during vegetative multiplication, may begin to be expressed during developmental amplification. We discuss the relevance of this stochastic developmental variability to classical genetic observations of Nanney and their collaborators on other T. thermophila loci. © 1992 Wiley-Liss, Inc.
Licorice-derived compounds inhibit linoleic acid (C:18:2ω6) desaturation in soybean chloroplasts

Although glycyrrhizic acid, a major constituent of licorice root, has important pharmacological effects in humans, the biological activity of glycyrrhizic acid and its aglycone glycyrrhetinic acid in plants is unknown. Here we report that these licorice-derived compounds and the analog carbenoxolone inhibit desaturation of linoleic acid (C18:2ω6) in soybean chloroplasts using monogalactosyldiacylglycerol and phosphatidylcholine substrates in an in vitro assay for desaturase activity. At 10 nM glycyrrhetinic acid, there is significant inhibition of desaturation of linoleic acid suggesting that licorice-derived compounds could prove useful in investigating biochemical pathways of linoleic acid desaturation in plant chloroplasts and plant desaturase regulation, which has application in modification of plant response to environmental stress, as well as optimization of oil seed composition.
Three-component layer double hydroxides by urea precipitation: structural stability and electrochemistry

Abstract Three-component layer double hydroxides (LDHs) with varying compositions were produced by urea precipitation, and tested for their stability and electrochemical performance. Optimum initial metal ion concentrations in the starting solutions were established. Initial Al 3+ concentration in the solution needs to be at least 0.015 M for the LDH formation. From the solutions with initial Al 3+ concentration of 0.025 M, higher fractions of Ni 2+ and Co 2+ could be recovered. Co 2+ could be incorporated at various levels without disturbing the LDH structure. LDH structure proved stable once it formed. Cyanate in the LDHs was dominantly N-bonded which contributed to the stability of the structure. Highest specific discharge capacity delivered by a LDH was 336 mAh/g, which was about 30% higher than that by β-Ni(OH) 2 . LDHs reached their stable capacities at a lower rate than either β-Ni(OH) 2 or the interstratified-Ni(OH) 2 (α+β). The interstratified sample delivered the highest capacity compared to any of the tested compositions.
Simplifying the Development and Usage of Fixtures for Sheet Metal and Composite Aircraft Parts

Based on a survey of small- to medium-sized companies that supply sheet metal parts to the major aircraft manufacturers, there is a need for a more simplified, flexible and inexpensive method to design, fabricate and register part fixtures used for CNC post forming operations (e.g., trimming, drilling). Consequently a method has been developed that bases fixture development completely on the CAD model, eliminates the need for datum surfaces and registration features on the CNC machine workbed, and makes fixture fabrication as easy and inexpensive as possible while still maintaining high geometrical accuracy. Practical implementation of this simplified method and an actual case study are discussed.
Lovastatin release from polycaprolactone coated β-tricalcium phosphate: Effects of pH, concentration and drug–polymer interactions

The approach of local drug delivery from polymeric coating is currently getting significant attention for both soft and hard tissue engineering applications for sustained and controlled release. The chemistry of the polymer and the drug, and their interactions influence the release kinetics to a great extent. Here, we examine lovastatin release behaviour from polycaprolactone (PCL) coating on β-tricalcium phosphate (β-TCP). Lovastatin was incorporated into biodegradable water insoluble PCL coating. A burst and uncontrolled lovastatin release was observed from bare β-TCP, whereas controlled and sustained release was observed from PCL coating. A higher lovastatin release was observed pH7.4 as compared to pH5.0. Effect of PCL concentration on lovastatin release was opposite at pH7.4 and 5.0. At pH5.0 lovastatin release was decreased with increasing PCL concentration, whereas release was increased with increasing PCL concentration at pH7.4. High Ca(2+) ion concentration due to high solubility of β-TCP and degradation of PCL coating were observed at pH5.0 compared to no detectable Ca(2+) ion release and visible degradation of PCL coating at pH7.4. The hydrophilic-hydrophobic and hydrophobic-hydrophobic interactions between lovastatin and PCL were found to be the key factors controlling the diffusion dominated release kinetics of lovastatin from PCL coating over dissolution and degradation processes. Understanding the lovastatin release chemistry from PCL will be beneficial for designing drug delivery devices from polymeric coating or scaffolds.
Reactive ion etching of indium tin oxide by SiCl4-based plasmas—substrate temperature effect

Abstract In this paper, plasma etching of ITO over a large temperature range, i.e., 25°C to 250°C, based on the SiCl4 gas has been studied. CF4 and CH4 have been added into the plasma to examine the gas mixture effect. The result shows that, for each gas stream, there is a threshold temperature in the etch rate vs. temperature curve. Temperature has a drastic effect on the etch rate above the threshold temperature. This is because that the high substrate temperature enhances the etch reaction rate as well as the residue removal rate. Below the threshold temperature, the etch rate is slightly influenced by the temperature. This is probably due to the low residue removal rate. Even when the substrate temperature is higher than the threshold temperature, there exists a threshold power for each gas stream. This demonstrates that ion bombardment effect is not negligible at high temperature. Residue components on the etched surfaces have been identified with electron spectroscope for chemical analysis (ESCA). The residue formation mechanism can be used to explain the etch rate difference among various feed streams.
Filaroidiasis in the dog: a review

— —Two Metastrongyloid nematodes are known to be parasitic in the dog. One, Filaroides osleri, produces verminous nodules in the trachea and main bronchi and may interfere with normal respiration. The other, Filaroides milksi, has selected as final habitat the lung parenchyma, and is usually an incidental rinding on histologic examination. Resume— —Deux nematodes metastrongyloides connus comme etant parasites chez le chien. L'un, Filaroide osleri, produit des modules vermineuses dans la trachee et les bronches et peut gener la respiration normale. L'autre, Filaroide milksi, a choisi comme habitat final le parenchyme des bronches et est d'habitude une decouverte fortuite dans l'examen histologique. Zusammenfassung— —Zwei Metafadenwurmnematoden sind als Parasiten in Hunden bekannt. Der eine—Filaroides osleri—verursacht verseuchte Knotchen in der Luftrohre und in den Haupt-bronchien und kann den normalen Atmungsvorgang storen. Der andere—Filaroides milksi—hat als endgultigen Standort das Lungenorgangewebe gewahlt und wird gewohnlich im Laufe histologischer Untersuchungen zufallig entdeckt.
Measuring and monitoring heavy-oil reservoir properties

The level of interest in heavy-oil and bitumen reservoirs has dramatically increased in recent times, stimulating research on their properties under various conditions. Rock physics provides the crucial link between the physical properties of the reservoir and seismic properties that can be remotely measured; however, there is currently no robust model to predict or infer the properties of heavy-oil or bitumen sands from seismic data, nor is there sufficient experimental data to calibrate such models. This is due to the particularly challenging nature of experimental measurements of heavy-oil sands.
Activation of DOPA decarboxylase by pyridoxal phosphate.

Abstract DOPA decarboxylase from rat liver was purified by chromatography on DEAE-Sephadex. The purified enzyme decarboxylates o-tryosine, m-tyrosine, DOPA and 5-hydroxytryptophan at different rates. The pH optimum for all substrates was found to be 7.2. The enzyme has the characteristic absorption spectrum of other pyridoxal enzymes, thus indicating that pyridoxal phosphate is probably a prosthetic group. The activity of DOPA decarboxylase is increased by the addition of pyridoxal phosphate even though this substance is already present probably as a prosthetic group. The degree of activation varies with the substrate and also with the pH of the reaction. It appears that the cofactor requirement is independent of the pyridoxal phosphate which is present as a prosthetic group.
Complications related to the administration of general anesthesia in 600 developmentally disabled dental patients.

A retrospective survey was made of complications that occurred in a series of 600 developmentally disabled patients after the administration o f general anesthetics for dental treatment. A retrospective survey of complications related to the administration of general anesthesia in the dental treatment of 600 developmentally disabled patients is presented. Thorough preoperative evaluation, appropriate anesthetic management, and close postoperative observation are emphasized in the treatment of these patients.
Idiopathic familial myocardiopathy in three generations: A clinical and pathologic study

A peculiar non-hypertrophic myocardiopathy is described which occurred in three and possibly five generations of a single family. Clinical features included systolic murmurs, electrocardiographic abnormalities, and sudden cardiac death with a paucity of symptoms of cardiac dysfunction. Pathological studies in three generations showed a striking similarity of cardiac findings including globular and dilated ventricles, endocardial fibroelastosis, and mitral valve thickening. Myocardium in two showed basophilic degeneration and fibrosis. A retrospective genealogic analysis and a prospective clinical evaluation of living family members suggested an autosomal dominant mode of inheritance with variable penetrance. The cause of this heritable myocardiopathy is presumably a mutant gene; the biochemical defect to which the mutant gene gives rise remains unknown.
A 33S enrichment in ureilite meteorites: evidence for a nebular sulfur component

Abstract Acid volatile sulfur extracted from ureilite meteorites carries a small 33 S enrichment relative to carbonaceous chondrites, enstatite chondrites, ordinary chondrites, and troilite from iron meteorites: Δ 33 S (=δ 33 S − 1,000 × (1 δ 34 S/1,000) 0.515 − 1) = 0.042‰ ± 0.007‰ (standard error of 22 analyses). In situ production of sulfur by cosmic-ray spallation reactions involving Fe is unlikely to cause the enrichment because the ureilites have short cosmic-ray exposure ages, low Fe/S relative to the only documented phases that contain spallogenic sulfur (the metal phase in iron meteorites), and no corresponding 36 S enrichment. Sulfur derived from cosmic-ray spallation has been documented in the metal phase in iron meteorites, and it is characterized by Δ 36 S/Δ 33 S ∼ 8, inconsistent with present observations. We argue that this enrichment derives from heterogeneity in the presolar nebula. A 33 S enrichment in the presolar reservoir may derive from mixing among diverse nucleosynthetic sources or from mass-independent fractionations caused by gas-phase chemistry. In addition, several gas-phase reactions have been shown to produce mass-independent compositions for sulfur isotopes. One that both matches fractionations for all sulfur isotopes and is relevant to the presolar nebula has yet to be identified. An appropriate additive nucleosynthetic component has also not been identified.
Evaluation of a CO2 partial rebreathing functional residual capacity measurement method for use during mechanical ventilation.

Objective There is a need for an automated bedside functional residual capacity (FRC) measurement method that does not require a step change in inspired oxygen fraction. Such a method can be used for patients who require a high inspired oxygen fraction to maintain arterial oxygenation and for patients ventilated using a circle breathing system commonly found in operating rooms, which is not capable of step changes in oxygen. We developed a CO2 rebreathing method for FRC measurement that is based on the change in partial pressure of end-tidal carbon dioxide and volume of CO2 eliminated at the end of a partial rebreathing period. This study was designed to assess the accuracy and precision of the proposed FRC measurement system compared to body plethysmography and nitrogen washout FRC.
Inertial instability of large Rossby number horizontal shear flows in a thin homogeneous layer

Abstract A horizontal shear flow having a Rossby number, Ro, greater than unity on a rotating plane can become unstable when its shear value is less than −f, the Coriolis frequency. In this paper, this instability is investigated for an O(10 km) submesoscale, sinusoidal shear flow in a thin homogeneous fluid layer as in an oceanic mixed layer or a shallow sea. The most unstable mode is shown by a linear analysis to occur in a narrow localized region centered around the maximum anticyclonic current shear. However, nonlinear numerical calculations show that the instability can grow to encompass both unstable and stable regions of the current. A consequence of this finite-amplitude evolution is the formation of surface convergence/shear fronts. The possibility that inertial instability mechanism is a source of some surface convergence/shear features seen in remote sensing images of the sea surface is discussed. A comparison is made with the shear-flow instability that can occur concurrently in a sinusoidal shear current, and inertial instability is shown to be the dominant instability mechanism in the immediate range above Ro=2.
Platelet-derived Growth Factor (PDGF) Stimulates the Association of SH2-Bβ with PDGF Receptor and Phosphorylation of SH2-Bβ

We recently identified SH2-Bβ as a JAK2-binding protein and substrate involved in the signaling of receptors for growth hormone and interferon-γ. In this work, we report that SH2-Bβ also functions as a signaling molecule for platelet-derived growth factor (PDGF). SH2-Bβ fused to glutathione S-transferase (GST) bound PDGF receptor (PDGFR) from PDGF-treated but not control cells. GST fusion protein containing only the SH2 domain of SH2-Bβ also bound PDGFR from PDGF-treated cells. An Arg to Glu mutation within the FLVRQS motif in the SH2 domain of SH2-Bβ inhibited GST-SH2-Bβ binding to tyrosyl-phosphorylated PDGFR. The N-terminal truncated SH2-Bβ containing the entire SH2 domain interacted directly with tyrosyl-phosphorylated PDGFR from PDGF-treated cells but not unphosphorylated PDGFR from control cells in a Far Western assay. These results suggest that the SH2 domain of SH2-Bβ is necessary and sufficient to mediate the interaction between SH2-Bβ and PDGFR. PDGF stimulated coimmunoprecipitation of endogenous SH2-Bβ with endogenous PDGFR in both 3T3-F442A and NIH3T3 cells. PDGF stimulated the rapid and transient phosphorylation of SH2-Bβ on tyrosines and most likely on serines and/or threonines. Similarly, epidermal growth factor stimulated the phosphorylation of SH2-Bβ; however, phosphorylation appears to be predominantly on serines and/or threonines. In response to PDGF, SH2-Bβ associated with multiple tyrosyl-phosphorylated proteins, at least one of which (designated p84) does not bind to PDGFR. Taken together, these data strongly argue that, in response to PDGF, SH2-Bβ directly interacts with PDGFR and is phosphorylated on tyrosine and most likely on serines and/or threonines, and acts as a signaling protein for PDGFR.
Effects of density-dependent inhibition of growth on phospholipid metabolism in monolayer cultures of animal cells.

Abstract The onset of density-dependent inhibition of growth is correlated with a change in the synthesis of the major phospholipids of either BHK-21 (hamster) and 3T3 (mouse) cells. The change consists of inhibition of phosphatidylcholine synthesis while the synthesis of phosphatidylethanolamine remains constant or increases. The incorporation of radioactive precursors reflects turnover rates, since no significant differences were observed in phospholipid composition. No major differences in fatty acyl chains of these same phospholipids were observed as a function of growth rate despite considerable individuality of relative patterns of polar lipids in both cell lines. No other density-dependent differences in phospholipid metabolism were observed which were common to both cell lines. These results suggest that major aspects of growth regulation may be metabolic rather than compositional and that regulation of the enzymes of lipid metabolism may be useful probes of effector mechanisms in growth control.
Evaluation of exercise-induced bronchospasm in the adult asthmatic

Abstract It has been shown that most asthmatics respond to exercise with bronchospasm. This study was undertaken to develop a safe and reliable method for quantifying exercise-induced bronchospasm in the asthmatic adult. Five normal adult volunteers and 12 stable asthmatics were exercised to 80% of their predicted maximal heart rate according to a multistage branching treadmill protocol. Their responses in terms of forced expiratory volume in 1 sec (FEV 1 ) and maximum midexpiratory flow rate (MMEFR) at 5, 15, and 30 min after exercise were assessed, while standing, with a Jones Pulmonar II waterless spirometer. This submaximal stress test was chosen because 80% of predicted maximal heart rate could be obtained by all individuals and allowed the asthmatics to exercise long enough for inducible bronchospasm to occur. Audible wheezing was induced in 100% of the asthmatics and in none of the nonasthmatics. In the normal individuals, FEV 1 and MMEFR increased significantly during the postexercise period. When compared to normal subjects, the 12 asthmatic patients demonstrated a significant reduction in FEV 1 an MMEFR (ΔFEV 1 : 5 min, −300; 15 min, −304; 30 min, −208 ml; −18%, −17%, and −15%; ΔMMEFR: 5 min, −15; 15 min, −9; 30 min, −1L/M; −23%, −18%, and −6%) (p 1 and MMEFR in the postexercise period appears to be a useful tool in assessing the presence and severity of exercise-induced bronchospasm in the adult asthmatic.
A membrane filter method for the enumeration of aquatic ammonifiers

Abstract A standard procedure for the enumeration of heterotrophic bacteria, utilizing heterotrophic plate count medium (m-HPC), has been modified to allow bacterial ammonifier populations also to be counted. Nessler's reagent was included as an outside indicator to ascertain what portion of the population is capable of ammonification. Typically the ammonifier population varied among aquatic habitats, ranging from 0.08 to 37.0% of the heterotrophic population in river water samples, 0.2 to 10.6% for irrigation water samples, and 1.4 to 3.0% for pond and lake water samples.
Ozone-induced ethylene production is dependent on salicylic acid, and both salicylic acid and ethylene act in concert to regulate ozone-induced cell death.

Summary Ethylene is known to influence plant defense responses including cell death in response to both biotic and abiotic stress factors. However, whether ethylene acts alone or in conjunction with other signaling pathways is not clearly understood. Ethylene overproducer mutants, eto1 and eto3, produced high levels of ethylene and developed necrotic lesions in response to an acute O3 exposure that does not induce lesions in O3-tolerant wild-type Col-0 plants. Treatment of plants with ethylene inhibitors completely blocked O3-induced ethylene production and partially attenuated O3-induced cell death. Analyses of the responses of molecular markers of specific signaling pathways indicated a relationship between salicylic acid (SA)- and ethylene-signaling pathways and O3 sensitivity. Both eto1 and eto3 plants constitutively accumulated threefold higher levels of total SA and exhibited a rapid increase in free SA and ethylene levels prior to lesion formation in response to O3 exposure. SA pre-treatments increased O3 sensitivity of Col-0, suggesting that constitutive high SA levels prime leaf tissue to exhibit increased magnitude of O3-induced cell death. NahG and npr1 plants compromised in SA signaling failed to produce ethylene in response to O3 and other stress factors suggesting that SA is required for stress-induced ethylene production. Furthermore, NahG expression in the dominant eto3 mutant attenuated ethylene-dependent PR4 expression and rescued the O3-induced HR (hypersensitive response) cell death phenotype exhibited by eto3 plants. Our results suggest that both SA and ethylene act in concert to influence cell death in O3-sensitive genotypes, and that O3-induced ethylene production is dependent on SA.
Seismic waveform tomography with multicomponent data at a groundwater contamination site

Summary We have developed an SH-wave version of frequencydomain full waveform tomography. Acoustic and SH waveform tomography are applied to a multicomponent seismic data set acquired over a shallow contaminated aquifer at Hill Air Force Base, Utah. We present synthetic tests of the method and field data inversions. Synthetic waveform tomography tests reveal fundamental differences in the interaction of acoustic and SH-waves with subsurface velocity perturbations, and illustrate potential benefits of SH-wave imaging at the field site such as significantly higher resolution associated with lower velocity. Highresolution velocity models from inversion of the field data are interpreted in terms of lithology and water saturation, which are better constrained by the availability of both Pand S-wave velocity.
Impact of Providing Off-Site Economic Development Funds to Dependent Regions Surrounding the U.S. DOE's Major Nuclear Weapons Sites

Abstract Using an interregional econometric simulation model, a comparative analysis was made of the economic impacts of providing funds for environmental management, education, and infrastructure to the regions surrounding four of the United States Department of Energy's massive former nuclear weapons sites in Idaho, Tennessee, South Carolina, and Washington. Infrastructure funds were used to build sewers, water lines, roads, bridges, and maintain existing infrastructure. Education funds were invested in higher education, primary and vocational schools, books, and libraries. Environmental management funds were invested in on-site remediation. Education produced the most jobs and personal income per dollar of investment, followed by environmental management. Infrastructure, by far, produced the least impact. An important reason for these results is that the relatively small regional economies surrounding these sites are unable to supply the goods and services required for major expansions. Hence, there is considerable leakage of investments to other regions. The limitations of these models to capture feedbacks from investments is emphasized.
Application of the Moving Boundary Truncation Method to Reactive Scattering : H + H2, O + H2, O + HD

The moving boundary truncation (MBT) method is a time-dependent adaptive method that can significantly reduce the number of grid points needed to perform accurate wave packet propagation while maintaining stability. This work presents a more robust variation of the method. Significant improvements have been made that allow the MBT method to be applied to any potential energy surface and used with any propagation method. The new variation of MBT is applied to the collinear H + H 2 reaction (using a LEPS potential) to demonstrate the stability and accuracy. Reaction probabilities are calculated for the three-dimensional nonrotating O( 3 P) + H 2 and O( 3 P) + HD reactions to demonstrate that the MBT can be used with a variety of numerical propagation techniques.
Hematopoietic stem cell transplantation for severe combined immunodeficiency in the neonatal period leads to superior thymic output and improved survival

All genetic types of severe combined immunodeficiency (SCID) can be cured by stem cell transplantation from related donors. The survival rate approaches 80%, and most deaths result from opportunistic infections acquired before transplantation. It was hypothesized that the survival rate and kinetics of immune reconstitution would be improved for infants receiving transplants in the neonatal period (first 28 days of life), prior to the development of infections. A 19.2-year retrospective/prospective analysis compared immune function in 21 SCID infants receiving transplants in the neonatal period with that in 70 SCID infants receiving transplants later. Lymphocyte phenotypes, proliferative responses to mitogens, immunoglobulin levels, and T-cell antigen receptor excision circles (TRECs) were measured before transplantation and sequentially after transplantation. Of 21 SCID infants with transplantations in the neonatal period, 20 (95%) survive. Neonates were lymphopenic at birth (1118 ± 128 lymphocytes per cubic millimeter). Infants receiving transplants early developed higher lymphocyte responses to phytohemagglutinin and higher numbers of CD3+ and CD45RA+ T cells in the first 3 years of life than those receiving transplants late ( P < .05). TRECs peaked earlier and with higher values ( P < .01) in the neonatal transplantations (181 days to 1 year) than in the late transplantations (1 to 3 years). SCID recipients of allogeneic, related hematopoietic stem cells in the neonatal period had higher levels of T-cell reconstitution and thymic output and a higher survival rate than those receiving transplants after 28 days of life. An improved outcome for this otherwise fatal syndrome could be achieved with newborn screening for lymphopenia so that transplantation could be performed under favorable thymopoietic conditions.
Sterilization: an option for all women.

Surgical sterilization generally tubal ligation is the most widely used contraceptive method in the United States. The permanence high efficacy and lack of hormonal side effects are attractive features of tubal ligation. With laparoscopic techniques the incidence of a significant medical complication is 0.1% to 0.5%. Unfortunately the family of a woman with a cognitive disability faces significant barriers to obtaining this procedure for her.
ExBox: A Polycyclic Aromatic Hydrocarbon Scavenger

A template-directed protocol, which capitalizes on donor–acceptor interactions, is employed to synthesize a semi-rigid cyclophane (ExBox4+) that adopts a box-like geometry and is comprised of π-electron-poor 1,4-phenylene-bridged (“extended”) bipyridinium units (ExBIPY2+). ExBox4+ functions as a high-affinity scavenger of an array of different polycyclic aromatic hydrocarbons (PAHs), ranging from two to seven fused rings, as a result of its large, accommodating cavity (approximately 3.5 A in width and 11.2 A in length when considering the van der Waals radii) and its ability to form strong non-covalent bonding interactions with π-electron-rich PAHs in either organic or aqueous media. In all, 11 PAH guests were observed to form inclusion complexes with ExBox4+, with coronene being the largest included guest. Single-crystal X-ray diffraction data for the 11 inclusion complexes ExBox4+⊂PAH as well as UV/vis spectroscopic data for 10 of the complexes provide evidence of the promiscuity of ExBox4+ for the vari...
Characterization of metallic multilayers for X-ray optics

Abstract X-ray reflectivity is a sensitive tool for characterizing interfaces in multilayers. Using an appropriate model, the low-angle θ-2θ spectra can be fit to yield the thickness and roughness of each layer. For Si/Mo, a model that includes an interlayer at the Mo on Si interface gives much better results than a simple bilayer model. Non-specular X-ray scattering measurements are particularly sensitive to roughness that is correlated from layer to layer because correlated roughness gives rise to reasonant scattering in particular non-specular directions. The non-specular behavior can be understood in terms of current theories of X-ray scattering from multilayers. Structural parameters, such as spatial frequencies of the correlated roughness and a coherence length for the correlations can be determined from these data. For the Si/Mo multilayers studied, spatial frequencies below 1/200 A-1 are correlated throughout the multilayer.
Political Disequilibrium and Scientific Inquiry: A Comment on William Riker's “Implications from the Disequilibrium of Majority Rule for the Study of Institutions”

representations of economic markets, he infers that political scientists are disadvantaged in their "science" in contrast to economists, whose paradigm Riker has borrowed. But this claim seems less than compelling. First, the presumed stability of markets is an abstract fiction that most economists recognize as a theoretical impossibility. Second, traditional definitions of equilibria may provide inadequate predictions and explanations. Third, thefiction that most economists recognize as a theoretical impossibility. Second, traditional definitions of equilibria may provide inadequate predictions and explanations. Third, the presence of an equilibrium in a static model does not guarantee its presence in more robust dynamic conceptualizations. Finally, disequilibrium of the traditional sort does not preclude explanation and science. The presumed stability of markets resides principally in our abstract description of them and not necessarily in reality. That description is largely static and thereby precludes the "disequilibrium" occasioned by changing tastes and technologies. Neither economists nor anyone else knows much about tastes, how they are formed, and the laws governing their change. And, while abstract descriptions of markets might predict how the introduction of new technologies affects prices and consumption, these descriptions cannot anticipate that technology. Indeed, we can think of the firm
Oscillatory zoning of Mn in solution-grown calcite crystals

Abstract Oscillatory zoning of Mn in calcite was produced in free-drift solution growth experiments. The repetitive Mn-doped subzones, imaged using cathodoluminescence microscopy, are not correlated with external controls or perturbations, and they generally cannot be correlated between crystals. The fluctuations causing the oscillatory zoning form autonomously in a system far from equilibrium and represent an example of self-organization.
A Statistical Analysis of the Earth's Internal Magnetic Field

The earth's internal magnetic field consists of the field of a large dipole and an irregular part which is of the order of a few percent of the main dipole field. The field may be represented by a series of spherical harmonics and 42 coefficients are numerically known. The coefficients which characterize the irregular part of the field are here statistically compared with a simple model for this field. It is assumed that an arbitrary number of dipoles are thrown at random inside a spherical shell and mean values are calculated for the probabilities with which the various spherical harmonics appear in the field produced. It is shown that a statistical agreement between the observed and calculated coefficients can be obtained only if the outer radius of the spherical shell is approximately $0.50R$ and is definitely not in excess of the radius of the earth's core, $0.55R$ ($R$, earth's radius). The result is independent of the number of dipoles producing the field. It seems that if the latter number is not very large, the result does not depend too critically upon the assumption of completely random distribution of the dipoles.
Performance of super-resolution enhancement for LADAR camera data

Laser detection and ranging (LADAR) camera systems are increasingly used in robotics applications for autonomous navigation and obstacle avoidance. Their compact size, high frame rate, wide field-of-view, and low cost are key advantages over traditional scanning LADAR devices. However, these benefits are achieved at the cost of spatial resolution. Therefore super-resolution image reconstruction technology can be applied to improve the resolution of LADAR camera data. Previous work by Rosenbush et al. applied the super-resolution algorithm of Vandewalle et al. to LADAR camera data, and observed quantitative improvement in image quality in terms of number of edges detected. This study uses the super-resolution algorithm of Young et al. to enhance the resolution of range data acquired from a commercial available LADAR camera. This work applies a preprocessing stage that increases the accuracy of sub-pixel shift estimation for improved registration of multiple LADAR camera frames and uses the triangle orientation discrimination methodology for a subjective evaluation. The objective is to measure the improvement in probabilities of target discrimination at various ranges achieved by super-resolution enhancement of LADAR camera data.
A Comparison of Cyclonic Ring Structures in the Northern Sargasso Sea

Abstract Field observations provide a data base that supports a comparison of ring structures in terms of the background Sargasso Sea environment. Five ring surveys, three from the 1967 sequence, a big baby ring and ring AL, were selected for this study. Anomalies of temperature, salinity, transport potential energy density, heat content and sound velocity have been examined using a reference which closely approximates Iselin's characteristic T-S relation for the western gyre. The results for the 1967 sequence demonstrate an initial reduction in anomaly strengths followed by strong ring stability. Comparison of two different rings, possibly equal in age, show the effect of the initial water mass conditions on anomaly strengths. Comparison of a cyclonic ring and the big baby ring reveals similar anomaly strengths and sizes in the same geographical region for rings that are assumed to be two and eleven months in age, respectively. This suggests that big baby rings can initially represent more intense pertur...