cssi/SciSciGPT-SciSciNet huggingface dataset:
Esophageal distension induced gastric relaxation is mediated in part by vagal peripheral reflex mechanism in rats

Abstract The effect of short-term lower esophageal distension on intragastric pressure (IGP) and the related neural pathways involved were investigated in urethane-anesthetized rats in which enteric nervous system connections were interrupted by ligations of the pylorus and the gastroesophageal junction while keeping the gastric vagus nerve trunks intact. Under these conditions, lower esophageal distension with a bolus of 0.2 to 0.5 ml saline in 0.1 ml step increments, raised the inside esophagus balloon pressure from 1.89±0.17 to 4.21±0.13 cm H 2 O and reduced IGP from −0.42±0.08 to −0.77±0.12 cm H 2 O, respectively. Bilateral cervical vagotomy partly blocked the gastric relaxation induced by 0.5 ml esophageal distension from −0.77±0.12 to −0.34±0.02 cm H 2 O; in contrast, a further bilateral splanchnectomy partly rebounded the effect of 0.5 ml esophageal distension from −0.34±0.02 to −0.46±0.05 cm H 2 O. These results suggest that the enteric nervous system may not play a prominent role in acute esophageal distension induced-gastric relaxation. However, more than 50% of this effect is central nervous system mediated (via the long vago–vagal reflex). The other 40% can be maintained without central and enteric nervous systems involvement, probably via a proposed gastric vagal afferent–esophageal collateral reflex.
Livestock, soil compaction and water infiltration rate: Evaluating a potential desertification recovery mechanism

Models predict that desertification, the loss of perennial grasses in arid and semiarid environments, will be difficult to reverse due to the positive feedback between plant cover and water infiltration; reductions in plant cover concurrently reduce water infiltration to a level that is insufficient for grass growth and recruitment. Thus, a desertified state becomes stable. However, these models cannot account for recently reported perennial grass recovery in desertified habitats. Here, we suggest a novel mechanism to explain these observations: the natural increase in water infiltration rate associated with recovery from livestock-induced soil compaction. We empirically evaluate this mechanism by comparing vegetation, water infiltration rates and soil compaction at three nearby, desertified livestock exclosures that differ in time since livestock removal and perennial grass recovery; the oldest exclosure (54 years) has experienced a significant increase in perennial grasses, while there has been no such increase at the two younger exclosures (25 and 10 years). Across sites, relative differences (inside compared to outside) in water infiltration rate and soil compaction increased across each grazing fence with time since livestock removal. The relative difference in soil compaction and relative difference in water infiltration rate were significantly greatest at the sole exclosure in which perennial grasses have recovered. These data support a key aspect of desertification models: the importance of water infiltration rate for resilience of vegetation in desertified systems. Although water infiltration rate plays a critical role in understanding the stability of desertified systems, theoretical models of desertification have only incorporated plant cover as the key mechanism affecting infiltration rate. Our work suggests soil compaction may also be an important mechanism.
Correlates of later-onset cannabis use in the National Epidemiological Survey on Alcohol and Related Conditions (NESARC).

Background Much of the research surrounding correlates of cannabis initiation has focused on adolescent and young adult populations. However, there is growing evidence that cannabis onset occurs later in life as well and little is known of the risk and protective influences that are associated with late-onset cannabis initiation.
A uniqueness-theorem for “linear” thermal baths

Abstract We consider systems in contact with a “linear” thermal bath, modeled by an additive thermal noise and an additive dissipation term which depends linearly on the system velocity. It is shown that the dissipation term and the bath temperature uniquely fix all statistical properties of the noise, without referring to any microscopic details of the bath. While the fluctuation dissipation theorem fixes only the second moment (correlation) of the noise, our present theorem extends to all moments. As a consequence, any linear thermal bath can be imitated by a harmonic oscillator bath model and the noise statistics is always Gaussian.
On left cancellative semigroups

In this note we shall describe the structure of left cancellative semigroups. We shall also investigate the existence of idempotents and show that the existence of idempotents is related to the existence of maximal proper right ideals.
Localization of the Distal Tip in the Colonoscopy Training Model Using Light Sensors

colon. This information also helps the student if he requires inserting a surgical tool along with the colonoscope. In the present study, the distal end of colonoscope is localized using photocells. The colonoscope has a light source for the camera at its distal end. These photocells are connected in basic comparator circuit. The photocells are fitted at specific locations on rubber colon, whose voltage changes on reception of light beam. The photocells are interfaced with a data acquisition system, using which data are acquired. While tracking the distal end, noise created in some photocells at particular instant yields misleading information. In order to avert such occurrence, an algorithm is written separately for advancement and retraction. Using these data, distal end is accurately localized and also specific time required during the test, to pass the colonoscope through specific parts of colon for further analysis.
THE IMPACT OF SUBURBAN GROWTH RESTRICTIONS ON U.S. HOUSING PRICE INFLATION, 1975–1978

The paper estimates a simultaneous equations model of housing price inflation 1975-1978 for a cross-section of 51 metropolitan areas. A two-stage least squares procedure is used to estimate the demand-side and supply-side determinants of price changes. One of the major sources of inflation is shown to be a variable reporting suburban growth restrictions—the fraction of potentially developed land just beyond the margin of urban settlement that is sequestered from growth. Nearly two-thirds of the SMSAs in our sample had growth restrictions, with an average of 12% of available suburban land set off-limits to growth. Some cities barred growth from as much as 30 to 40% of the nearby surrounding land. Such controls were found to have contributed significantly to inflation. The growth-controlled cities experienced an inflation rate that was about 17% higher than those that did not restrict, ceteris paribus- 12.5% instead of 10.8% annually, 1975-1978.
Behaviour of RC beams under combined shear and torsion according to AASHTO LRFD and ACI equations

In this study, the AASHTO LRFD provisions for combined shear and torsion have been investigated and their accuracy has been validated against experimental data. AASHTO LRFD (2008) provisions on combined shear and torsion have also been compared to the pertinent ACI code requirements for the behaviour of reinforced concrete beams subjected to combined shear and torsion. In this comprehensive comparison, different sections with high strength and normal strength concrete as well as over-reinforced, moderately-reinforced and, under-reinforced solid and hollow sections were analysed. This study resulted in findings on the applicability of both code procedures to different sectional material and geometry values under these load combinations.
The interaction of acetylene with Ni(111), chemisorbed oxygen on Ni(111), and NiO(111); the formation of CH species on chemically modified Ni(111) surfaces

Abstract Ultraviolet photoelectron spectroscopy, temperature programmed thermal desorption and low-energy electron diffraction have been used to study the interaction of acetylene with a clean Ni(111) surface, with a Ni(111) surface having co-adsorbed oxygen and with an epitaxially grown NiO(111) surface produced by room temperature oxidation ofNi(111). The adsorption of a (2 × 2) overiayer of π-bonded acetylene or oxygen on the Ni(111) surface markedly alters the subsequent interaction and reaction of the surface with incident acetylene. We find that in the presence of either a (2 × 2) overiayer of oxygen or π-bonded acetylene, a new more strongly bound hydrocarbon phase forms at room temperature. We identify this new phase from its ionization levels as a CH species, and for saturation coverages we find approximately twice as many of these species as the number of π-bonded acetylene molecules in the (2 × 2) structure. Preadsorption of oxygen limits the adsorption of π-bonded acetylene but does not affect the subsequent formation of this CH species. Exposure of acetylene to NiO at room temperature produces only CH species. Based upon these results we propose idealized models for the bonding geometry of π-bonded acetylene and CH species on the Ni(111) surface. The conditions for the formation of CH species and the significance of CH species to surface reactions on Ni are also discussed.
Measurements of absolute electron-emission spectra from grazing-incidence ion-surface collisions

Convoy electron spectra have been measured in coincidence with specularly reflected ions in grazing-incidence collisions of carbon ions with a silicon (100) surface. Absolute yields of convoy electrons have been determined experimentally and compared with the results obtained from a classical trajectory Monte Carlo simulation. By comparing the velocity dependence of the convoy yields with theory, we are able to assess the relative contribution to convoy emission from valence and core electron capture to continuum states of the projectile. {copyright} {ital 1998} {ital The American Physical Society}
Noncovalent probes for the investigation of structure and dynamics of protein‐nucleic acid assemblies: The case of NC‐mediated dimerization of genomic RNA in HIV‐1

The nature of specific RNA-RNA and protein-RNA interactions involved in the process of genome dimerization and isomerization in HIV-1, which is mediated in vitro by stemloop 1 (SL1) of the packaging signal and by the nucleocapsid (NC) domain of the viral Gag polyprotein, was investigated by using archetypical nucleic acid ligands as noncovalent probes. Small-molecule ligands make contact with their target substrates through complex combinations of H-bonds, salt bridges, and hydrophobic interactions. Therefore, their binding patterns assessed by electrospray ionization mass spectrometry can provide valuable insights into the factors determining specific recognition between species involved in biopolymer assemblies. In the case of SL1, dimerization and isomerization create unique structural features capable of sustaining stable interactions with classic nucleic acid ligands. The binding modes exhibited by intercalators and minor groove binders were adversely affected by the significant distortion of the duplex formed by palindrome annealing in the kissing-loop (KL) dimer, whereas the modes observed for the corresponding extended duplex (ED) confirmed a more regular helical structure. Consistent with the ability to establish electrostatic interactions with highly negative pockets typical of helix anomalies, polycationic aminoglycosides bound to the stem-bulge motif conserved in all SL1 conformers, to the unpaired nucleotides located at the hinge between kissing hairpins in KL, and to the exposed bases flanking the palindrome duplex in ED. The patterns afforded by intercalators and minor groove binders did not display detectable variations when the corresponding NC-SL1 complexes were submitted to probing. In contrast, aminoglycosides displayed the ability to compete with the protein for overlapping sites, producing opposite effects on the isomerization process. Indeed, displacing NC from the stem-bulges of the KL dimer induced inhibition of stem melting and decreased the efficiency of isomerization. Competition for the hinge region, instead, eliminated the NC stabilization of a grip motif formed by nucleobases of opposite strands, thus facilitating the strand-exchange required for isomerization. These noncovalent probes provided further evidence that the structural context of the actual binding sites has significant influence on the chaperone activities of NC, which should be taken in account when developing potential drug candidates aimed at disrupting genome dimerization and isomerization in HIV-1.
Estrogen priming affects the sensitivity of midbrain central gray neurons to microiontophoretically applied LHRH but not beta-endorphin.

In vivo single-unit extracellular recording was used to assess neuronal membrane sensitivity at the level of the midbrain central gray (MCG) to the iontophoresis of luteinizing hormone releasing hormo
Effect of Spatial Confinement on the Glass-Transition Temperature of Patterned Polymer Nanostructures

Poly(methyl methacrylate) (PMMA) nanostructures embedded with a fluorescence tag are fabricated using electron beam lithography on oxidized silicon substrates. The glass transition temperatures (Tgs) of these one-dimensional (1-D) nanostructures (parallel lines) are measured by monitoring their temperature-dependent fluorescence intensities, revealing substantial differences between the Tgs of the nanostructures and the thin films from which they were fabricated. For example, the Tg of 50-nm-wide PMMA nanolines on silica is ∼15 K lower than that of a PMMA film on silica of the same 18 nm thickness. Attractive PMMA−silica interfacial interactions increase the Tg, while free surfaces decrease the Tg of PMMA in ultrathin films relative to bulk PMMA. Thus, the significant differences between the Tgs of the 1-D and two-dimensional (2-D) forms of PMMA on silica are the result of a substantial increase in the ratio of free-surface area to interfacial area in the PMMA nanolines relative to ultrathin films.
Comparing a new algorithm with the classic methods for estimating the number of factors

Abstract This paper presents and compares a new algorithm for finding the number of factors in a data analytic model. After we describe the new method, called NUMFACT, we compare it with standard methods for finding the number of factors to use in a model. The standard methods that we compare NUMFACT with are Malinowski's indicator function, Wold's cross-validation approach, Bartlett's test, scree plots, the rule-of-one, and using the number of factors (eigenvectors) needed to explain 90% of the trace of a correlation matrix. Using a diverse set of real applications, NUMFACT is shown to be the clear method of choice.
A new Approach to Active‐Site Binding Analysis. Inhibitors of Acetylcholinesterase

Receptor site binding is shown to be localized in selected atoms or substructures with relatively minor contributions from the remaining molecular framework. Related compounds can be overlayed to form a lowest common structure or hyper-molecule that defines every possible binding site for the series. Any attempt to analyze binding data on an atom-by-atom basis would clearly fail if all or most of the positions were involved in the energetics. In most data sets, analysis becomes feasible when most of the variance depends on a minority of the total occupied positions. This appears to be the case in most of the sets analyzed to date, providing us with a unique opportunity. By using atomic descriptors to model lipophilicity, London forces, steric repulsion and charge interactions, the binding site can be mapped by regression analysis. Each important site of interaction and the nature of the binding force can be clearly identified. This procedure provides a statistical method based on measured data that fully complements the visual fitting of modeled drugs into defined receptor sites by computer graphics. It has enormous potential for analysis of drug, agrochemical and toxicological binding data where crystallized enzymes and fully defined sites are unknown and may long remain so. The method is illustrated by examples drawn from acetylcholinesterase receptor site binding.
Protracted QTc Prolongation following Treadmill Testing Identifies a Type 1 Long QT Mutation that is Resistant to PKA Activation

Background Type 1 long QT syndrome (LQT1) is caused by loss-of-function mutations in KCNQ1, the gene that encodes the pore-forming α-subunit of the slowly activating delayed rectifier K + current (I Ks ). During β-adrenergic stimulation, protein kinase A (PKA) activation increases I Ks to prevent a dangerous prolongation of the ventricular action potential. LQT1 patients with mutations resistant to PKA activation are at greater risk for life-threatening arrhythmias. The purpose of this study is to identify LQT1 mutations resistant to PKA activation. Methods Retrospective analyses of the treadmill stress test results of LQT1 patients indicated that KCNQ1-I235N (p.Iso235Asn) exacerbated the delay in QTc latency recovery following treadmill stress testing. We used voltage-clamping techniques to study KCNQ1 current (I KCNQ1 ) in HEK293 cells expressing wild-type KCNQ1 (WT) or WT+I235N (to mimic the patients' genotype), the I Ks β-subunit KCNE1, and the I Ks PKA regulatory protein AKAP9 (Yotiao). Results LQT1 patients typically show a peak in QTc prolongation at 3 minutes during their recovery from treadmill stress testing. The change in QTc between the first and fifth minutes of recovery (ΔQTc) is typically KCNQ1 similar to native-like I Ks (n = 11). Compared with WT, cells coexpressing WT+I235N conducted maximal I KCNQ1 that was 32% smaller ( P P KCNQ1 in cells expressing WT by 64% (n = 4, P KCNQ1 only increased 23% in cells expressing WT+I235N (n = 4 each, P >.05). Conclusions LQT1 patients with delayed recovery in QTc prolongation following treadmill testing might indicate mutations that are resistant to PKA activation. These patients could be at high risk for life-threatening events but may derive a pronounced benefit from β-blocker therapy.
Elemental carbon in sediments: Determination and isotopic analysis in the presence of kerogen

Abstract A procedure has been developed for separate measurement and isotopic analysis of kerogen and elemental C (soot, charcoal) in sedimentary rocks. The carbonaceous residue left after HF-HCl dissolution is oxidized with 0.10 MCr2O7= in 2 MH2SO4 at 50°C. Kerogen reacts with a half-life of 6–180 hrs, depending on maturity, and thus can be quantitatively removed from elemental C, which reacts more slowly ( t 1 2 ≈ 600–2000 hr ). The amount and isotopic composition of kerogen and elemental C are then obtained by measurement of etched and unetched samples, after applying a correction for the loss of elemental C in the etch. The rate of the oxidation reaction has been studied in detail for carbon black and for carbonaceous residues from 2 K-T boundary clays, and less extensively for 12 samples of charcoal and kerogen. Most materials obey first-order kinetics to a fair approximation, but carbon black and K-T soot—both consisting of spherules—show a sudden, 4.0 or 1.7-fold increase in the rate after a mass loss of 23 or 82%, respectively. Apparently the interiors of soot spherules are more reactive than the exteriors.
Suddenly expanding recirculating and non-recirculating viscoplastic non-newtonian flows

Viscoplastic non-Newtonian flows through axisymmetric 1:5 and 1:2 sudden expansions have been studied numerically by solving the mass and momentum conservation equations and the Bingham constitutive equation. Two distinct viscoplastic flow regimes are observed. For a given Reynolds number, increasing the yield number, a non-dimensional yield stress results in transitioning from a recirculating to a non-recirculating viscoplastic flow regime. For Newtonian fluids, a typical separating and reattaching flow field with a large corner recirculation region and a reattachment point is observed. For a low yield number viscoplastic non-Newtonian flow, the incoming flow separates, creating a weak recirculation region, and unyielded attached-to-the wall, corner and impingement regions. For a high yield number, a non-separating viscoplastic flow field forms, resulting in the elimination of flow recirculation and the formation of significant unyielded region behind the expansion plane. For Newtonian and low yield number viscoplastic flows, axisymmetric 1:5 expansion flows result in more intense recirculation, larger reattachment, and flow redevelopment lengths in comparison with axisymmetric 1:2 expansion flows.
Functional responses from guinea pigs with cochlear implants. I. Electrophysiological and psychophysical measures

We examined electrophysiological and psychophysical measures of the electrically stimulated auditory system of guinea pigs implanted with chronic intracochlear electrodes. Guinea pigs were trained to detect low-level acoustic stimuli and then unilaterally deafened and implanted with one extracochlear and two intracochlear electrodes. Electrically evoked auditory brainstem responses (EABRs) and psychophysical detection thresholds were obtained from the same animals using pulsatile stimuli. Supplementary EABR data were obtained from additional, untrained, animals. Thresholds were obtained as a function of stimulus phase duration and monopolar and longitudinal-bipolar electrode configurations. The slopes of the EABR and psychophysical functions for bipolar stimulation, averaged across subjects within 1 month after implantation, were -5.25 and -6.18 dB per doubling of pulse duration, respectively. These slopes were obtained with pulse durations ranging from 20 to 400 microseconds/phase; slope was reduced at longer pulse durations. Strength-duration slope also varied as a function of electrode configuration: monopolar stimulation produced steeper functions than did bipolar stimulation. Differences between EABR and psychophysical strength-duration measures suggest the existence of central mechanisms of stimulus integration in addition to that occurring at the level of the auditory nerve. Differences observed with variation of stimulus parameters (e.g., monopolar vs. bipolar stimulation modes) suggest that the specific mode of intracochlear electrical stimulation can influence stimulus integration. Such observations may be useful in the design of prosthetic devices and furthering our understanding of electrical excitation of the auditory system.
On the effects of macroeconomic policy in a maximizing model of a small open economy

Abstract This paper investigates the effects of government policies in a small open economy. Determination of the exchange rate and the effects of macroeconomic policies on the balance-of-payments accounts are examined in a model of infinitely lived, utility-maximizing agents who have perfect foresight. Residents of the country and the government borrow and lend in a world capital market which constrains them to live within their means. The dependence of consumption, leisure, and real-balance holdings on the present discounted value of government expenditure and real debt is demonstrated. Government policies must be dynamically consistent.
MachineSense: detecting and monitoring active machines using smart phone

Comparison of actual running machine and recognized running machine using our prototype system for 25 minutes of time. Multivariate Gaussian Acoustic Model Naive Bayes classifier with equal prior probability Circle 1,2,3 shows the position of a microwave, a fan and a vacuum cleaner respectively at our lab office. Square 1,2,3,4 and 5 shows the position from we have identified the current running machine using our prototype application. We develop a prototype system in Android phone (Nexus S)
Characterization and modeling for forging deformation of Ti-6Ai-2Sn-4Zr-2Mo-0.1 Si

The deformation behavior during upset forging has been determined for Ti-6242 in both the (α + β) and β starting microstructures. For (α + β), flow softening attributed to deformation heating was observed. Deformation heating accounted for only a fraction of the extensive flow softening of the β microstructure. The dependence of log σ on 1/T was linear for (α + β) and bilinear for the β microstructure, with an approximate transition temperature of 930 °C. The two temperature regimes for β corresponded to distinct deformed microstructures which were manifestations of different softening mechanisms, all promoting the flow-induced transformation of metastable β microstructure to the equilibrium (α + β) microstructure. Based on the experimental data, flow stress equations for both microstructures, and empirical equations describing the flow softening behavior of β have been developed. WithT and ġe as the only input variables, these equations can accurately predict the σ - e relationships for process modeling of this alloy.
Drosophila p53 Binds a Damage Response Element at the reaper Locus

The tumor suppressor gene p53 regulates multiple cellular responses to DNA damage, but the transcriptional targets that specify these responses are incompletely understood. We describe a Drosophila p53 homolog and demonstrate that it can activate transcription from a promoter containing binding sites for human p53. Dominant-negative forms of Drosophila p53 inhibit both transactivation in cultured cells and radiation-induced apoptosis in developing tissues. The cis-regulatory region of the proapoptotic gene reaper contains a radiation-inducible enhancer that includes a consensus p53 binding site. Drosophila p53 can activate transcription from this site in yeast and a multimer of this site is sufficient for radiation induction in vivo. These results indicate that reaper is a direct transcriptional target of Drosophila p53 following DNA damage.
Quality and petrographic characteristics of Paleocene coals from the Hanna basin, Wyoming

Coal beds from the Ferris and Hanna Formations, in the Hanna basin, south-central Wyoming, exhibit distinct differences in ash yield, sulfur content, and petrographic and palynologic constituents. These differences are interpreted to be controlled by tectonic changes of the Hanna basin and adjoining uplifts during evolutionary development, which, in turn, controlled mire chemistry and sedimentation. These conditions created two very different settings under which the peats developed during deposition of the Ferris and the Hanna Formations. In addition, there appears to be a geographic (latitudinal) and/or climatic control on the coal characteristics manifested by major differences of Paleocene coals in the Hanna basin compared to those in the Raton basin in Colorado and New Mexico and the Powder River basin in Wyoming.
A NUMERICAL STUDY OF NON-DARCIAN NATURAL CONVECTION IN A VERTICAL ENCLOSURE FILLED WITH A POROUS MEDIUM

A numerical study of non-Darcian natural convection in a vertical enclosure filled with a porous medium is performed. The flow is modeled using the Brinkman-Forchheimer-extended Darcy equations. The governing equations are solved with the SIMPLER algorithm and good agreement with previously reported numerical and experimental results is found. An order of magnitude analysis and the numerical results demonstrate the importance of non-Darcian effects. For high Darcy numbers (Da > 10−4), both extensions are of the same order of magnitude and must be used simultaneously. In addition, Forch-heimer's extension must be included for Pr ≤ 1.0 and all Darcy numbers. Finally, Nusselt number correlations are presented for three different ranges of the Darcy number covering wide ranges of the governing parameters.
Data reuse and the open data citation advantage

Background. Attribution to the original contributor upon reuse of published data is important both as a reward for data creators and to document the provenance of research findings. Previous studies have found that papers with publicly available datasets receive a higher number of citations than similar studies without available data. However, few previous analyses have had the statistical power to control for the many variables known to predict citation rate, which has led to uncertain estimates of the “citation benefit”. Furthermore, little is known about patterns in data reuse over time and across datasets. Method and Results. Here, we look at citation rates while controlling for many known citation predictors and investigate the variability of data reuse. In a multivariate regression on 10,555 studies that created gene expression microarray data, we found that studies that made data available in a public repository received 9% (95% confidence interval: 5% to 13%) more citations than similar studies for which the data was not made available. Date of publication, journal impact factor, open access status, number of authors, first and last author publication history, corresponding author country, institution citation history, and study topic were included as covariates. The citation benefit varied with date of dataset deposition: a citation benefit was most clear for papers published in 2004 and 2005, at about 30%. Authors published most papers using their own datasets within two years of their first publication on the dataset, whereas data reuse papers published by third-party investigators continued to accumulate for at least six years. To study patterns of data reuse directly, we compiled 9,724 instances of third party data reuse via mention of GEO or ArrayExpress accession numbers in the full text of papers. The level of third-party data use was high: for 100 datasets deposited in year 0, we estimated that 40 papers in PubMed reused a dataset by year 2, 100 by year 4, and more than 150 data reuse papers had been published by year 5. Data reuse was distributed across a broad base of datasets: a very conservative estimate found that 20% of the datasets deposited between 2003 and 2007 had been reused at least once by third parties. Conclusion. After accounting for other factors affecting citation rate, we find a robust citation benefit from open data, although a smaller one than previously reported. We conclude there is a direct effect of third-party data reuse that persists for years beyond the time when researchers have published most of the papers reusing their own data. Other factors that may also contribute to the citation benefit are considered. We further conclude that, at least for gene expression microarray data, a substantial fraction of archived datasets are reused, and that the intensity of dataset reuse has been steadily increasing since 2003.
Velocity-Modulated Reflex Oscillator

A mathematical analysis of the mechanism utilized by the microwave reflex oscillator in producing high-frequency oscillations from a direct-current beam of electrons is presented. A simplified small-signal theory is postulated in which the electrodes are assumed to be ideal parallel planes and the electron motion is rectilinear, uninfluenced by space charge. The finite transit time of the electrons in traversing the modulator gap is taken into consideration. From this theory are derived expressions for the velocity modulation and the resultant current-density modulation of the beam by action of a retarding field. An equation is derived for the fundamental-frequency component of the current induced in the tank circuit. The necessary conditions for the self-starting of oscillations are determined, and the minimum starting current is given as a function of the tank-circuit characteristics and the optimum transit-angle values. Equations are derived for the rate of change of oscillating frequency with reflector voltage and beam voltage. To determine the amount of electronic tuning possible, calculations are made of the range over which the reflector voltage can be varied for a particular mode and oscillations maintained. An efficiency curve is given for the conversion of beam-current power to high-frequency power, and optimum efficiencies are calculated for conditions in which the amplitude of oscillation is small. Efficiency curves are also presented for the case of large amplitudes when the transit angle of the modulator gap is negligibly small.
An O(n) algorithm for width determination of power/ground routes for VLSI circuits

Abstract This paper deals with one aspect of routing power and ground nets in integrated circuits composed of modules, where the nets are routed in the channels between the modules. Constraints on allowable voltage drops along these routes exist in order to maintain proper logic levels and switching speed. An O( n ) procedure for determining the width of routes in power and ground trees is presented, where the objective is to minimize the area of the power and ground routes subject to the voltage drop constraints.
Olfactory Bulb Removal Eliminates Mating Behavior in the Male Golden Hamster

Mating behavior in sexually naive and sexually experienced male golden hamsters was totally eliminated by removing their olfactory bulbs. In contrast, the mating behavior in blinded, unilaterally bulbectomized, and sham-operated controls was essentially normal. Testosterone injections restored normal sexual behavior in castrated controls but had no effect on the bilaterally bulbectomized animals.
Leukocyte Adhesion to the Coronary Microvasculature During Ischemia and Reperfusion in an In Vivo Canine Model

Background Prompt reperfusion of ischemic myocardium or myocardium that is in the process of becoming infarcted is a cornerstone of current therapy for coronary artery disease. Paradoxically, experimental evidence suggests that cardiac damage may be caused by the reperfusion itself. Leukocyte attachment to the coronary vascular endothelium during reperfusion may be an initiating step in this detrimental process. Leukocyte adhesion to microvascular endothelium has never been demonstrated directly in a cardiac model of ischemia and reperfusion. Methods and Results Fluorescent videomicroscopy through a special “floating” objective that allows a series of lenses to move in unison with the beating dog heart was used on the left ventricular surface of open-chest dogs. Epicardial microvessels (25 to 130 μm), in focus throughout the cardiac cycle, were recorded after infusion of acridine orange (to fluorescently label leukocytes) during either 1 hour of ischemia followed by 2 hours of reperfusion, 3 hours of isch...
Clinical trial of folinic acid to reduce vincristine neurotoxicity.

In a murine model system, folinic acid demonstrated host-protective properties during administration of repetitive and lethal doses of vincristine (VCR). Subsequently, folinic acid was evaluated in patients receiving VCR during an adjuvant chemotherapy program for stage II carcinoma of the breast. The toxicities, cumulative VCR dosage, and percentage of ideal dosage observed in 18 patients receiving folinic acid have been compared with those observed in 70 patients who previously received VCR without folinic acid in the same chemotherapy program. All patients ideally were intended to receive VCR 1.0 mg/m2 weekly for 6 weeks, with dose modification for neurotoxicity. Treatment patients received folinic acid 800 mg PO daily in three divided doses during the 6-week course. The degree of neurotoxic manifestations of VCR was similar in the treatment and comparison patients. Absent to mild neurotoxicity was observed in approximately 70% of patients in both groups; moderate or greater neurotoxicity occurred in about 30% of patients in both groups. Full dosage (6.0 mg/m2) was attained in 7 (39%) treatment patients and 17 (24%) comparison patients (P=0.21). The mean percentage of the ideal dosage of VCR was 73.7±28.7 in patients receiving folinic acid and 76.1±20.5 in those given only VCR (P=0.69). Hematologic toxicities were similar in both groups, but nausea occurred more frequently in the folinic acid group. Folinic acid in this dose and schedule afforded no protection from the neurotoxic side effects of VCR.
Relevance of the small crack problem to lifetime prediction in gas turbines

Abstract The anomalous behaviour of ‘small’ fatigue cracks is summarized, and the current bases for understanding this phenomenon are discussed. The limited literature pertaining to small cracks in nickel-base superalloys is reviewed, and the consequences of this behaviour upon the lifetime prediction of gas turbines are evaluated for a typical case. Evaluation of lifetimes using large crack data is found to be non-conservative, especially at lower stress (longer lifetimes). It is shown that improvement in the resolution of non-destructive inspection techniques leads to even greater discrepancy between lifetime estimates based on small crack or large crack growth rate data.
Traction force microscopy in Dictyostelium reveals distinct roles for myosin II motor and actin-crosslinking activity in polarized cell movement.

Continuous cell movement requires the coordination of protrusive forces at the leading edge with contractile forces at the rear of the cell. Myosin II is required to generate the necessary contractile force to facilitate retraction; however, Dictyostelium cells that lack myosin II ( mhcA – ) are still motile. To directly investigate the role of myosin II in contractility we used a gelatin traction force assay to measure the magnitude and dynamic redistribution of traction stresses generated by randomly moving wild-type, myosin II essential light chain null ( mlcE – ) and mhcA – cells. Our data show that for each cell type, periods of rapid, directed cell movement occur when an asymmetrical distribution of traction stress is present, in which traction stresses at the rear are significantly higher than those at the front. We found that the major determinants of cell speed are the rate and frequency at which traction stress asymmetry develops, not the absolute magnitude of traction stress. We conclude that traction stress asymmetry is important for rapid, polarized cell movement because high traction stresses at the rear promote retraction, whereas low traction at the front allows protrusion. We propose that myosin II motor activity increases the rate and frequency at which traction stress asymmetry develops, whereas actin crosslinking activity is important for stabilizing it.
Effects of Phonological Complexity Training on Pseudoword Reading in Acquired Phonological Dyslexia

Individuals with acquired phonological dyslexia experience difficulty associating written letters with corresponding sounds, especially with pseudowords. In training studies with children, when phonologically “more complex” consonant clusters were trained, improvement was noted on trained clusters and untrained “less complex” clusters, but not vice versa. To date, no treatment studies for acquired phonological dyslexia have systematically manipulated phonological complexity to improve reading ability. The present study applied principles of phonological complexity to letter-sound training in acquired phonological dyslexia. Our findings suggest phonological complexity can be used to improve generalization to untrained phonologically related words in this population.
Paternal Absence and Its Effect On Adolescent Self-Esteem:

Recent research has indicated that father absence is significantly related to self-concept of black adolescent males. Results suggest that where paternal absence exists in the home situation, the level of self-esteem tended to be affected more for males than for females. Where father was absent in the home, males tended also to have lower levels of self-esteem than females. Where self-esteem of the child and core-facilitative conditions in mother were correlated significantly (p less than .05), male self-esteem was likely to be affected negatively. Therefore, presence of maternal core-facilitative conditions can favourably effect self-esteem of both male and female adolescents in father-absent homes.
SU-C-224-09: Energy and Dose Calibration of a Synchrotron-Produced Monochromatic X-Ray Beam

Purpose: This work describes planned enhancements to a synchrotron medical radiological beamline, which will improve its efficacy for therapeutic and diagnostic radiological research using monochromatic x‐rays. The primary focus of the present study was the beamline's energy and dosecalibrations prior to sample irradiation. This work is crucial for an ongoing study of cell survival of IUdR‐laden cells undergoing photoactivated Auger electron therapy using monochromatic x‐rays. Methods: Calibrations of the monochromatic x‐ray beam are essential for checking the beam energy as well as understanding the variability of the beam quality and dose output. Energy measurements have been performed using Bragg diffraction of a collimated beam from a crystalline siliconpowder sample (Si640c). The resulting Debye‐Scherrer diffraction rings were recorded using a digital x‐ray detector. This detector has replaced the use of radiographic film utilized for earlier measurements.Dosemeasurements of the beam have been performed in a PMMA phantom, using a cylindrical air‐equivalent chamber to measure the dose to water for depths of 0.6 – 10.1 cm. Results: Current results suggest that the beam energy can be measured to within < 0.1 keV. Exposure times of 2 seconds were used to record the Debye‐Scherrer rings, and this has greatly improved upon the 30 – 60 minute exposure times required using radiographic film. The dose rate has been calibrated as a function of the decaying synchrotron ring current, and changes in the beam quality following synchrotron re‐injection have been demonstrated. Conclusions: The use of a digital x‐ray detector has improved the efficiency of the energy measurements. The dosecalibrationmeasurements provide a reliable test of the variability of the beam quality and dose output. This research was supported by contract W81XWH‐10‐1‐0005 awarded by The U.S. Army Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702‐5014. This report does not necessarily reflect the position or policy of the Government, and no official endorsement should be inferred.
A macrophage Fc gamma receptor and the mast cell receptor for IgE share an identical subunit.

Fc receptors for immunoglobulins are found on many immune cells and trigger essential functions of the immune defence system. With the exception of the high-affinity receptor for immunoglobulin E (FcɛRI), these receptors were thought to consist of single polypeptides. FceRI is a tetrameric complex of one α-subunit, one β -subunit and two γ-subunits. Here we report the cloning of a polypeptide identical to the γ-chains of FcɛRI, from mouse macrophages that do not express this receptor. Biosynthetic labelling and gene transfer together show that these γ-chains associate with one of the macrophage receptors (FcγRIIa). The human homologue, FcγRIII (CD 16), from natural killer cells is also expected to associate with γ-chains. It is possible that these e-chains and the homologous ζ-chains of the T-cell antigen receptor belong to a new family of related proteins which share a common role in the signal transducing pathway.
Formulation of a mmaA4 gene deletion mutant of Mycobacterium bovis BCG in cationic liposomes significantly enhances protection against tuberculosis.

A new vaccination strategy is urgently needed for improved control of the global tuberculosis (TB) epidemic. Using a mouse aerosol Mycobacterium tuberculosis challenge model, we investigated the protective efficacy of a mmaA4 gene deletion mutant of Mycobacterium bovis BCG (ΔmmaA4BCG) formulated in dimethyl dioctadecyl ammonium bromide (DDA) – D(+) trehalose 6,6 dibenenate (TDB) (DDA/TDB) adjuvant. In previous studies, deletion of the mmaA4 gene was shown to reduce the suppression of IL-12 production often seen after mycobacterial infections. While the non-adjuvanted ΔmmaA4BCG strain did not protect mice substantially better than conventional BCG against a tuberculous challenge in four protection experiments, the protective responses induced by the ΔmmaA4BCG vaccine formulated in DDA/TDB adjuvant was consistently increased relative to nonadjuvanted BCG controls. Furthermore, the ΔmmaA4BCG-DDA/TDB vaccine induced significantly higher frequencies of multifunctional (MFT) CD4 T cells expressing both IFNγ and TNFα (double positive) or IFNγ, TNFα and IL-2 (triple positive) than CD4 T cells derived from mice vaccinated with BCG. These MFT cells were characterized by having higher IFNγ and TNFα median fluorescence intensity (MFI) values than monofunctional CD4 T cells. Interestingly, both BCG/adjuvant and ΔmmaA4BCG/adjuvant formulations induced significantly higher frequencies of CD4 T cells expressing TNFα and IL-2 than nonadjuvanted BCG or ΔmmaA4BCG vaccines indicating that BCG/adjuvant mixtures may be more effective at inducing central memory T cells. Importantly, when either conventional BCG or the mutant were formulated in adjuvant and administered to SCID mice or immunocompromised mice depleted of IFNγ, significantly lower vaccine-derived mycobacterial CFU were detected relative to immunodeficient mice injected with non-adjuvanted BCG. Overall, these data suggest that immunization with the ΔmmaA4BCG/adjuvant formulation may be an effective, safe, and relatively inexpensive alternative to vaccination with conventional BCG.
Supervised language modeling for temporal resolution of texts

We investigate temporal resolution of documents, such as determining the date of publication of a story based on its text. We describe and evaluate a model that build histograms encoding the probability of different temporal periods for a document. We construct histograms based on the Kullback-Leibler Divergence between the language model for a test document and supervised language models for each interval. Initial results indicate this language modeling approach is effective for predicting the dates of publication of short stories, which contain few explicit mentions of years.
Resource-advantage theory: A snake swallowing its tail or a general theory of competition?

Deligonul and cavusgil (1997) conduct a paradigm-level analysis of resource-advantage (R-A) theory. They argue that (1) Hunt and Morgan (1995) offer resource-advantage theory as a replacement for p...
Pyroelectric properties of the modified triglycine sulphate (TGS) single crystals

Abstract Several doping substitutions (Li+, Mn+, D+, P+5, As+5) in the TGS structure have been studied and the pyroelectric and dielectric properties measured. In the case of TGS single crystals modified by partial substitution of (P04 −3 and (As04)−3 groups for the (S04)−2. higher pyroelectric coefficients and an enhancement of the pyroelectric material figure of merit (p/K) > 2 x TGS have been observed.
Medical and osteopathic boards' positions on chaperones during gynecologic examinations.

Abstract Objective: The objective of this study was to determine whether United States medical or osteopathic boards have opinions, position statements, or policies on chaperone use, and whether any state laws regulate chaperone use. Methods: United States Medical and Osteopathic Boards were surveyed by mail to determine whether policies, opinions,positions, or laws exist regarding use of chaperones during gynecologic examinations. We sent the survey to executives at 67 state boards, identified by a list from The Federation of State Medical Boards. Our main outcome measure was positive response to the survey questions. Results: Of 67 targeted sites, 61 responded (91%). Fourteen sites (23%) reported having informal or unpublished opinionsrecommending chaperones. Eleven sites (18%) reported having positions related to chaperones that have been published fortheir physicians. Four sites (6.5%) reported having policies specifically related to chaperone use. Thirty-two sites (52.5%) reported that they do not have opinions, positions, orpolicies related to chaperone use. No site reported state laws governing chaperone use. Conclusion: Response to our survey showed no concensus among state medical boards on the use of chaperones, leaving doctors and patients to decide for themselves whether they want or need chaperones present during gynecologicexaminations.