cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of nicotinic therapies on attention and executive functions in chronic low-dose MPTP-treated monkeys

Chronic administration of low doses of the neurotoxin MPTP to nonhuman primates induces cognitive deficits similar to those seen in early Parkinson's disease (PD) patients, without the confounding effect of significant motor impairment. The present study assessed the extent to which specific attentional and central executive deficits in chronic low dose (CLD) MPTP-treated monkeys could be modified by nicotinic therapies. Four adult male rhesus monkeys were trained to perform attention and executive function tasks and were then administered low doses of MPTP (dose range: 0.025-0.1 mg/kg, i.v.) over 98-158 days until stable cognitive deficits appeared. Results showed that both nicotine and the alpha4beta4 subtype-selective nAChR agonist SIB-1553A could improve certain aspects of attentional and central executive functioning in this model of early Parkinsonism. Nicotine failed to improve performance of CLD-MPTP-treated animals on an attention set-shifting task while SIB-1553A significantly improved at least some aspects of performance, suggesting that the compound increased the animals' ability to maintain a previously formed response set and restored cognitive flexibility. Both nicotine and SIB-1553A caused a dose-dependent enhancement of performance on the focused attention (cued reaction time) task, decreasing reaction times on both cued and noncued trials. Nicotine caused a significant reduction in reaction times but did not alter the error profile on an impulse (motor readiness) task. SIB-1553A reduced reaction times but caused an increase in bar release (i.e. impulsivity) errors. These data suggest that nicotinic drugs may have therapeutic potential for treating cognitive dysfunction in PD.
Success of ERCP at a referral center after a previously unsuccessful attempt

Background: The diagnostic and therapeutic success of endoscopic retrograde cholangiopancreatography (ERCP) depends on a number of factors. When an attempt at ERCP fails, the physician must decide whether to repeat the procedure, rely on another imaging procedure (noninvasive or invasive), or refer to another endoscopist/center. Our aim in this prospective study was to determine the role of a second attempt at ERCP at a referral ERCP center. Methods: Five hundred sixty-two patients were referred for ERCP after having undergone a previous unsuccessful attempt to visualize the clinically relevant duct(s). Results: The overall success in visualizing the desired duct was 96.4% (542 of 562). Advanced techniques for cannulation were used in 41% (229 of 562). Anatomic abnormalities possibly contributing to the previous lack of success were present in 27% of cases. ERCP with or without manometry identified a cause or potential cause for the signs and symptoms in 86% of patients. Sixty complications occurred in 57 patients (10.1%). ERCP was unsuccessful in 20 patients (3.6%). Conclusions: The cannulation success rate and diagnostic yield of further ERCP with an acceptable complication rate warrant consideration of referral to centers with available resources and expertise. (Gastrointest Endosc 2000;52:478-83.)
Network control as a distributed object application

We describe our experiences and performance figures from an open-switching approach to broadband (ATM) connection management. The control system described is the lowest layer of a general connection management architecture such as TINA or Xbind.
Protein kinase C downregulates IKs by stimulating KCNQ1-KCNE1 potassium channel endocytosis

Background The slow-activating cardiac repolarization K + current ( I Ks ), generated by the KCNQ1-KCNE1 potassium channel complex, is controlled via sympathetic and parasympathetic regulation in vivo. Inherited KCNQ1 and KCNE1 mutations predispose to ventricular fibrillation and sudden death, often triggered by exercise or emotional stress. Protein kinase C (PKC), which is activated by α1 adrenergic receptor stimulation, is known to downregulate I Ks via phosphorylation of KCNE1 serine 102, but the underlying mechanism has remained enigmatic. We previously showed that KCNE1 mediates dynamin-dependent endocytosis of KCNQ1-KCNE1 complexes. Objective This study sought to determine the potential role of endocytosis in I Ks downregulation by PKC. Methods We utilized patch clamping and fluorescence microscopy to study Chinese hamster ovary (CHO) cells coexpressing KCNQ1, KCNE1, and wild-type or dominant-negative mutant (K44A) dynamin 2, and neonatal mouse ventricular myocytes. Results The PKC activator phorbol 12-myristate 13-acetate (PMA) decreased I Ks density by >60% ( P I Ks by PKC activation. PMA increased KCNQ1-KCNE1 endocytosis in CHO cells expressing wild-type dynamin 2, but had no effect on KCNQ1-KCNE1 endocytosis in CHO cells expressing K44A-dynamin 2, determined using the Pearson correlation coefficient to quantify endosomal colocalization of KCNQ1 and KCNE1 with internalized fluorescent transferrin. KCNE1-S102A abolished the effect of PMA on I Ks currents and endocytosis. Importantly, PMA similarly stimulated endocytosis of endogenous KCNQ1 and KCNE1 in neonatal mouse myocytes. Conclusion PKC activation downregulates I Ks by stimulating KCNQ1-KCNE1 channel endocytosis.
Radiation tolerance of type-II strained layer superlattice-based interband cascade infrared photodetectors (ICIP)

For space-based imaging systems radiation tolerance to both displacement damage and total ionizing dose (TID) radiation effects continues to be a major performance concern. Here, the TID and proton irradiance tolerance of mid wave infrared interband cascade infrared photodetectors (ICIPs) based on InAs/GaSb type II strained-layer superlattice (T2SLS) absorbers is presented. Protons of energy of 63 MeV were used to irradiate the unbiased ICIP detectors at room temperature to a proton fluence of 7.5 x 1011 protons/cm2, corresponding to a TID of 100 kRads(Si). A comparison of the detector performance of a variety of ICIPs with different numbers of electron barrier sizes cascade stages is presented. Performance of detectors of varying size was characterized by dark current and quantum efficiency measurements at different temperatures. Results show changes, increase in dark current and a reduction in the quantum efficiency, consistent with an increase in the trap density.
Teaching the Statement of Changes in Financial Position—A Worksheet Approach

(1986). Teaching the Statement of Changes in Financial Position—A Worksheet Approach. Journal of Education for Business: Vol. 61, No. 6, pp. 275-280.
Fuels for Heat Engines From Mild Gasification of Coal

The amount of oil imported into the United States in the last few years has increased sharply, and has again reached the point where the U.S. may be faced with an oil embargo by foreign oil suppliers. A large part of this oil is used in heat engines, for transportation and for the production of power during periods of peak demand.Copyright © 1989 by ASME
Retrogressive failures recorded in mass transport deposits in the Ursa Basin, Northern Gulf of Mexico

[1] Clay-rich mass transport deposits (MTDs) in the Ursa Basin, Gulf of Mexico, record failures that mobilized along extensional failure planes and transformed into long runout flows. Failure proceeded retrogressively: scarp formation unloaded adjacent sediment causing extensional failure that drove successive scarp formation updip. This model is developed from three-dimensional seismic reflection data, core and log data from Integrated Ocean Drilling Project (IODP) Expedition 308, and triaxial shear experiments. MTDs are imaged seismically as low-amplitude zones above continuous, grooved, high-amplitude basal reflections and are characterized by two seismic facies. A Chaotic facies typifies the downdip interior, and a Discontinuous Stratified facies typifies the headwalls/sidewalls. The Chaotic facies contains discontinuous, high-amplitude reflections that correspond to flow-like features in amplitude maps: it has higher bulk density, resistivity, and shear strength, than bounding sediment. In contrast, the Discontinuous Stratified facies contains relatively dim reflections that abut against intact pinnacles of parallel-stratified reflections: it has only slightly higher bulk density, resistivity, and shear strength than bounding sediment, and deformation is limited. In both facies, densification is greatest at the base, resulting in a strong basal reflection. Undrained shear tests document strain weakening (sensitivity = 3). We estimate that failure at 30 meters below seafloor will occur when overpressure = 70% of the hydrostatic effective stress: under these conditions soil will liquefy and result in long runout flows.
Cryogenic leak test procedure for a large superconducting cyclotron helium vessel

Abstract A procedure for testing the vacuum integrity of very large stainless steel weldments used at cryogenic temperatures has been developed at Michigan State University. This development, which uses large quantities of liquid nitrogen, is a modification of a technique commonly applied to small devices and involves cooling the cryostat's liquid helium vessel (bobbin) to liquid nitrogen temperature, and then proceeding immediately with leak testing. This method was applied to the K800 superconducting magnet helium vessel, which seemed leak tight at room temperature, but was found to have an easily detectable helium leak when cooled. After repairing the leak, retesting revealed no leaks, where upon the K800 cryostat construction was completed; i.e. the bobbin was wrapped with superinsulation, a liquid nitrogen radiation shield was added, and the assembly was inserted into the vacuum jacket. The final leak test occurred when the cryostat was cooled to liquid helium temperature and was found to be helium leak tight.
Gallbladder cancer: the role of laparoscopy and radical resection.

Objectives:We assess how laparoscopy has altered the presentation of patients with gallbladder cancer and determine whether radical resection in patients with gallbladder cancer is beneficial.Summary Background Data:The widespread adoption of laparoscopic cholecystectomy has led to an increased freq
Family intervention for Asian Americans with a schizophrenic patient in the family.

A family intervention model designed to meet the unique sociocultural needs of Asian-American schizophrenia patients and their families is proposed. This five-stage model consists of: preparation, engagement, psychoeducational (i.e., survivor skills) workshop, family sessions, and an ending stage. Guidelines and specific suggestions for implementing each of these stages are offered as a means of dealing effectively With Asian Americans' differential value orientations and cultural characteristics.
Cryo-EM structure of the small subunit of the mammalian mitochondrial ribosome.

The mammalian mitochondrial ribosomes (mitoribosomes) are responsible for synthesizing 13 membrane proteins that form essential components of the complexes involved in oxidative phosphorylation or ATP generation for the eukaryotic cell. The mammalian 55S mitoribosome contains significantly smaller rRNAs and a large mass of mitochondrial ribosomal proteins (MRPs), including large mito-specific amino acid extensions and insertions in MRPs that are homologous to bacterial ribosomal proteins and an additional 35 mito-specific MRPs. Here we present the cryo-EM structure analysis of the small (28S) subunit (SSU) of the 55S mitoribosome. We find that the mito-specific extensions in homologous MRPs generally are involved in inter-MRP contacts and in contacts with mito-specific MRPs, suggesting a stepwise evolution of the current architecture of the mitoribosome. Although most of the mito-specific MRPs and extensions of homologous MRPs are situated on the peripheral regions, they also contribute significantly to the formation of linings of the mRNA and tRNA paths, suggesting a tailor-made structural organization of the mito-SSU for the recruitment of mito-specific mRNAs, most of which do not possess a 5′ leader sequence. In addition, docking of previously published coordinates of the large (39S) subunit (LSU) into the cryo-EM map of the 55S mitoribosome reveals that mito-specific MRPs of both the SSU and LSU are involved directly in the formation of six of the 15 intersubunit bridges.
Methodology and apparatus for rapid power cycle accumulation and in-situ incipient failure monitoring for power electronic modules

Power cycling lifetime is a topic of continued interest in the power electronic module industry. For inverter power modules consisting of IGBT and diode power devices, wear-out mechanisms usually encountered are wirebond lift and solder joint degradation. Wirebond failures typically manifest in an upward shift in V ce(sat) well before an open circuit condition occurs. Solder joint degradation usually manifests as an increase in die temperature that may be detected by a calculation of thermal impedance. Design and manufacturing processes have matured so that highly reliable, high quality modules are available from numerous manufacturers. However, the burden still remains on manufacturers to demonstrate the power cycling lifetime of their products. Given the range of application conditions to which power modules may be exposed, it is beneficial to customers for manufacturers to provide power cycling lifetime data in terms of number of cycles to failure for various levels of delta-T j and various starting temperatures, T 0 . It is also beneficial, during design cycles, for module designers and manufacturing engineers to obtain quantified failure data on prototype designs regarding onset of the failure mechanisms mentioned. In this paper, we describe and demonstrate a method for the rapid accumulation of delta-T j cycles under various conditions and develop in-situ monitoring methods for V ce(sat) and V f which are of sufficient accuracy to detect incipient failures in the module, and which do not require the cessation of power cycling to perform a readout. In particular, a three phase inverter module consisting of six IGBTs and six anti-parallel diodes is tested in a multimodule, multi-operating point test stand. Three phase inductive loading with typical switching frequency and various amplitude sinusoidal current profiles is carried out under controlled starting temperatures for each module, while monitoring V ce(sat) , diode V f , and module substrate temperature. The V ce(sat) and V f are sampled at instants of known phase current so as to correlate with nominal device behavior in order to determine health of the wirebond and solder interfaces. Module control, data acquisition, load determination, failure detection, and data logging are described. Simulation techniques used to target the operating conditions necessary to achieve a particular delta-T j are shown, along with experimental data used to validate these simulations. Experimental results from the power cycling to date are shown.
A migration inhibition-factor assay for tumor immunity in man.

Abstract A migration inhibition factor (MIF) assay to detect cellular immunity to tumor antigens in man is described. This assay utilizes a 48-hr incubation period of lymphocytes with the tissue homogenate and subsequent assay of the supernate for inhibition of the migration of guinea pig peritoneal macrophages. With this method MIF is not demonstrable in the supernate of lymphocytes cultured with histoincompatible tissue homogenates and the assay can be applied to homologous as well as autologous tumor homogenates. It can thus be used to detect tumor immunity in patients and their healthy relatives or contacts.
Thermochemotherapy (combined cyclophosphamide and hyperthermia) with or without hyperglycemia as an adjuvant to radiotherapy

Abstract Our previous study demonstrated the presence of a thermochemotherapy-resistant cell fraction in a tumor. The present study investigated whether thermochemotherapy-resistant cells are radioresistant and whether thermochemotherapy changes the size of hypoxic cell fraction in the tumor. Early generation isotransplants of a spontaneous fibrosarcoma, FSa-II tumors, were used. A radiation dose that yields 50% tumor control rate in 150 days after local irradiation, TCD 50 , was determined. Cyclophosphamide (CY) was the test agent. TCD 50 values of the 4 mm tumor following γ-ray alone given under hypoxic conditions or in air were 80.9 or 65.8 Gy, respectively. Thermochemotherapy reduced TCD 50 values ≅ 20 Gy, suggesting that thermochemotherapy resistant cells are not identical to the radioresistant cells. Glucose administered 60 min before thermochemotherapy further reduced TCD 50 values. Foot-reaction scored in the tumor-controlled animals was significantly less severe following combined thermochemo-and radiotherapy compared to that following radiotherapy alone. Acute foot reaction studies also supported this observation. These results indicated that thermochemotherapy could be an excellent adjuvant to radiotherapy. Further studies using a 6 mm tumor indicated that thermochemotherapy was less effective on the large tumor than on the small tumor. Indirect analysis showed no significant changes in the size of hypoxic cell fraction following thermochemotherapy.
Hydrodynamic phase in cylindrically symmetric ultrarelativistic heavy ion collisions.

We carry out a numerical simulation of the hydrodynamic evolution of a cylindrically symmetric quark-gluon plasma of finite extent, as formed in a central collision of two identical ultrarelativistic heavy ions, assuming inviscid flow with Lorentz-invariant initial conditions within the plasma and an ideal gas equation of state. For the central collisions of /sup 238/U+ /sup 238/U at a center-of-mass energy of 30 GeV per nucleon, the critical temperature for hadronization is reached just 1.5 fm/c after the onset of hydrodynamic expansion, at which time the expansion is still predominantly longitudinal.
A Case Report on the Effect of Everolimus in Renal Angiomyolipoma Associated With Tuberous Sclerosis Complex

Tuberous Sclerosis (TS) is a well known disorder which manifests with benign tumors in various organ systems, including angiomyolipomas (AML) of the kidneys. The mTOR inhibitors have emerged as a potential systemic treatment strategy to halt the growth of renal angiomyolipomas and to prevent life threatening complications such as bleeding. This report shows that everolimus treatment may have an impact on size and density of renal AML lesions which may lead to prevention or delay the development of renal cell carcinoma as well as prevent bleeding from the renal AML lesions. A 20-year-old Hispanic female and a 24-year-old Asian female both with sporadic TS were administered daily oral everolimus therapy. Both showed stability in their renal AML lesions and notable improvement of their extra-renal TS manifestations. Treatment with daily everolimus may lead to reduction in size and/or decreases in density or renal AML lesions. This may have an impact on the risk of developing renal cell carcinoma as well as preventing bleeding from renal AML lesions. J Med Cases. 2014;5(3):129-136 doi: http://dx.doi.org/10.14740/jmc1665w
Effect of extreme exposure frequencies on different affective ratings of stimuli.

Two experiments examined the effects of extreme number of exposures on reactions to stimuli rated on several dimensions. The first experiment gave a positive monotone relationship between affective ratings on the GOOD-BAD scale and the frequency of stimulus exposure, with frequencies as high as 243. The second experiment obtained ratings for the same exposure frequencies on four scales, some of which measured affinitive approach while others measured exploratory approach reactions. The former tended to show an increase with frequency of exposure and the latter a decrease. Theoretical analysis attempted to reconcile experimental evidence which indicates increasing affect with increasing exposure and evidence for an inverted-U relationship.
Test of principle of an optical trigger for beauty

Abstract We have carried out a test of the principle of the Optical Trigger for Beauty proposed by Charpak, Giomataris, and Lederman. We measure the production and trapping by total internal reflection of Cherenkov light produced in a flat crystal of MgF2 by the passage of high-energy muons. Using an array of drift tubes to measure the trajectories of the muons, we observe a threshold in the production of trapped Cherenkov light as a function of muon incident angle. The shape of the threshold curve is consistent with that expected from a simple optical calculation. An angle-independent component of trapped Cherenkov light, apparently due to delta rays, is also observed. We discuss prospects for a practical device.
The Management of Established Glaucoma

The author reviews, from a conservative standpoint, present day opinions as to the safest and most reliable lines of treatment of various types of glaucoma. Read before the Kansas City Eye, Ear, Nose, and Throat Society.
Towards a specialized shell for diagnostic expert systems for chemical plant

Abstract Recent developments on the application of artificial intelligence (Al) concepts and techniques for the automation of chemical process fault diagnosis has met with some success. However, the process of developing such systems, called knowledge engineering, is time-consuming and expensive involving specialized labour. This bottleneck presents a serious barrier that must be overcome if the benefits of Al-based approaches are to be realized at large in the process industry. Towards that goal, we present an analysis of the knowledge engineering process in the context of process diagnosis and a possible solution strategy. By viewing the knowledge engineering activity at different levels of abstraction, one is able to identify how the different aspects of the bottleneck emerge and also clarify methodological issues from formalization- and implementation-related ones. The analysis suggests that a specialized environment or shell, that already possesses the diagnostic methodology and the related modelling constructs, is the natural way of circumventing the bottleneck. As a potential knowledge core of such a shell, a diagnostic methodology that has the characteristics to facilitate rapid prototyping, easy modification, and maintenance of diagnostic expert systems is described.
Studies of cross-resistance, synergistic combinations and blocking of activity of platinum derivatives

Summary Certain 1,2-diamino saturated cyclic platinum derivatives have a high degree of activity against transplanted mouse leukemias and show no cross-resistance to DDP. DDP and these cyclic compounds combine synergistically with derivatives of ara-C, VP16, and adriamycin. The toxic effects of both DDP and the diamino cyclic compounds can be blocked by certain thio containing compounds such as thiourea and methionine. Preliminary data suggest that thio rescue may improve the therapeutic index of the platinum derivatives.
Scheduling to Minimize the Number of Late Jobs When Set-Up and Processing Times are Uncertain

The n job, one-machine scheduling problem is considered where set-up and processing times are random and the objective is to minimize the number of late jobs. In the deterministic case, Moore's algorithm is known to produce an optimal schedule. A chance-constrained formulation of the nondeterministic problem is derived in which a job is processed if the probability that it will be completed prior to its due date is greater than a specified level. A deterministic equivalent problem is achieved to which application of a modification of Moore's algorithm is proven to produce an optimal schedule.
The geochemical cycling of stable Pb, 210Pb, and 210Po in seasonally anoxic Lake Sammamish, Washington, USA

Abstract The geochemical processes controlling the behavior of stable Pb, 210 Pb, and 210 po in seasonally anoxic Lake Sammamish, Washington were identified from water column distributions and box model calculations. Total (sum of dissolved and particulate) inventories of stable Pb, 210 Pb, and 210 Po increased in the whole lake during the latter part of the oxic stage of the lake and were attributed to diffusion from sediments. Large decreases in the total inventories of these elements occurred during the transition from oxic to anoxic conditions, and the lowest inventories were observed during the sulfidic stage of stratification. The cycling of stable Pb and 210 Pb during oxic periods appeared to be linked to Fe cycling while 210 Po cycling was more closely linked to the cycling of Mn. The behavior of stable and radioactive Pb and, possibly, 210 Po during anoxia was influenced by sulfur cycling. Thermodynamic calculations indicated that dissolved Pb concentrations might be controlled by PbS precipitation during anoxia. Flux balance calculations during stratification indicated that atmospheric deposition was the major source of both 210 Pb and 210 Po to the lake and fluvial input was more important for 210 Po than for 210 Pb. 210 Pb and 210 Po supplied by atmospheric deposition were scavenged and removed by sedimentation from the epilimnion. Residence times with respect to scavenging and sedimentation in the epilimnion were 1–3 and 617 days, respectively, for 210 Pb and 9–22 and 9–26 days for 210 Po. Model results in the hypolimnion indicated that at certain times the radionuclides diffused out of the sediments and at other times into the sediments. Residence times with respect to sedimentation of particulate nuclides in the hypolimnion were 2–124 days for 210 Pb and 8–48 days for 210 Po. The behavior of 210 Pb and 210 Po in Lake Sammamish was compared to that in B~' kford Reservoir, Massachusetts. Although the comparison indicated similarities (e.g., links to Fe and Mn cycling, larger scavenging rates for 210 Pb than for 210 Po), the major differences between the systems were that atmospheric inputs were greater than fluvial inputs, activities of the radionuclides were lower, and the presence of sulfide in the hypolimnion during anoxia affected the cycling of stable Pb, 210 Pb, and 210 Po in Lake Sammamish.
Evaluation of a multi-wavelength laser array with diffuse optical tomography

Diffuse Optical Tomography (DOT) is a new and promising medical imaging modality which uses near-infrared light to probe tissue properties. Using multiple wavelengths of light can provide important information about tissue metabolism and cancer malignancy. Unfortunately, in most DOT acquisition schemes, acquiring data for each wavelength has a multiplicative effect on the overall imaging time. In this paper, we evaluate a new multiple wavelength laser module (Praevium Research Inc.) with 12 laser diodes all coupled to a single output fiber. When used in conjunction with a cooled spectrometer, it allows simultaneous multi-wavelength data acquisition and hence, higher temporal resolution.
Farm size, land yields and the agricultural production function: An analysis for fifteen developing countries

Abstract The paper analyzes the relationship between factor inputs, land yields and labor productivity for farms of different size on the basis of FAO farm management data for 15 developing countries. For all but three countries a strong negative correlation is found between farm size on the one side, and factor inputs and yields per hectare on the other. The fitting of unconstrained production functions to the above data suggests that in only few cases the decline in yields for increasing farm size can be attributed to decreasing returns to scale. The higher yields observed in small farms are mainly to be ascribed to higher factor inputs and to a more intensive use of land. Therefore, where conspicuous labor surpluses exist, the superiority of small farming provides solid arguments in favor of land redistribution. Such an agrarian reform would determine higher output, higher labor absorption and a more equitable income distribution, thus contributing in a decisive manner to the alleviation of rural poverty. The paper also provides estimates of cross-sectional production functions for the 15 countries analyzed. Empirical relations are found between the output elasticities of land, labor and intermediate inputs and physical indicators of their scarcity. The paper concludes by proposing a simple method for deriving a long-term production function for agriculture.
Previewing and the Therapeutic Use of Metaphor

This paper proposes a new technique for diagnosing and treating conflict in adult patients. Referred to as previewing, the technique is grounded in the developmental progression from somatic modes of representation to symbolic modes of representation. During early life, infants experience the world primarily through sensory phenomena. Later in childhood, however, symbolic modes of representation become pre-eminent. The manner in which an individual represents conflict reflects this developmental progression. For example, if the patient manifests a psychosomatic symptom, it is likely that the conflict has been represented on a physical level and thus emerges in somatic form; if the conflict is expressed as a metaphor, however, it has probably been represented on a cognitive level and thus emerges as a symbol. Previewing, a technique derived from early life interaction between mother and infant, incorporates both the somatic and symbolic components of psychological disorganization and may therefore be of benefit in psychotherapy.
A numerical study of the marine stratocumulus cloud layer

A one-dimensional grid-level model including longwave radiative transfer and a level-4 second-order turbulent transfer closure which contains prognostic equations for turbulent quantities, is used to study the physics and dynamics of inversion-capped marine stratocumulus clouds.
Coupling of excitons with excitations of the Fermi sea in asymmetric quantum wells.

In asymmetric quantum wells, optical transitions couple a hole state with several conduction-band states. The coupling of excitons associated with higher subbands and free electrons in the lowest subband are investigated using a two-band Mahan--Nozi\`eres--De Dominicis Hamiltonian. The emission spectrum for carriers in the lowest subband shows a very weak Fermi edge singularity at the Fermi level. When the Fermi level approaches the second subband, coupling of excitons with excitations of the Fermi sea leads to a large enhancement of the emission spectrum at the Fermi level.
Imagewise model fitting for generating parametric images in dynamic PET studies

In this study, we explore the use of non-linear regression for model fitting of PET measured kinetics on a pixel-by-pixel basis for generating parametric images of micro-parameters of kinetic models. We evaluate quantitatively the noise propagation of two regression methods using computer simulated data, and examine the feasibility of generating parametric images for two different real PET studies -- a human FDG study and a monkey FDOPA study. The results demonstrated that general image-wise model fitting is practically feasible for dynamic PET studies.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Vibrational branching ratios and photoionization dynamics for N2O

Abstract Vibrational resolved constant-ionic-state spectroscopy is used to study photoionization of N2O We determine the ratio of partial photoionization cross sections for alternative vibrational levels of the N2O+ (A 2σ+) state and these vibrational branching ratios are dependent on excitation energy, implying that there is a breakdown of the Franck-Condon approximation. These results may be sampling the wings of a shape resonance.
Automation in American libraries

Despite its concentration on technical developments in library science, this survey is offered here because it is relevant to humanists for two reasons: first, that humanists all use libraries and therefore need to encourage their evolution to higher levels of efficiency, and, second, that the procedures outlined here may be of help to humanists in establishing procedures for their own research.
Intracisternal injection of CRF antagonist blocks surgical stress-induced inhibition of gastric secretion in the rat.

Abstract The effects of intracisternal injection of CRF antagonist, α-CRF 9–41, on the inhibition of gastric acid secretion elicited by intracisternal injection of corticotropin-releasing factor (CRF) and stress were investigated in conscious pylorus-ligated rats. Intracisternal injection of the α-helical CRF 9–41 (50 μg) did not influence basal gastric secretion, but injected concomitantly with intracisternal CRF (5 μg), completely blocked CRF (5 μg)-induced inhibition of gastric secretory volume, acid concentration and output. Intracisternal injection of α-helical CRF 9–41 (3, 10, 50 μg) produced a dose-related reversal (0, 52 and 100%) of brain surgery-induced inhibition of gastric acid output. By contrast intravenous injection of CRF antagonist (50 μg) did not inhibit gastric hyposecretory response to brain surgery. These data suggest that endogenous CRF in the brain may mediate stress-induced gastric hyposecretion in the rat.
Multiple Micellization and Dissociation Transitions of Thermo- and Light-Sensitive Poly(ethylene oxide)-b-poly(ethoxytri(ethylene glycol) acrylate-co-o-nitrobenzyl acrylate) in Water

This article reports on the synthesis of thermo- and light-sensitive hydrophilic block copolymers, poly(ethylene oxide)-b-poly(ethoxytri(ethylene glycol) acrylate-co-o-nitrobenzyl acrylate), and the study of their micellization/dissociation transitions in water in response to temperature changes and UV irradiation. The block copolymers with controlled molecular weights and narrow polydispersities were synthesized by atom transfer radical polymerization of a mixture of ethoxytri(ethylene glycol) acrylate and o-nitrobenzyl acrylate with a molar ratio of 100:10 from a PEO macroinitiator. Dynamic light scattering and fluorescence spectroscopy studies showed that these copolymers were molecularly dissolved in water at lower temperatures and self-assembled into micelles with the thermosensitive block associating into the core and the PEO block forming the corona when the temperature was above the lower critical solution temperature (LCST) of the thermosensitive block. Upon UV irradiation, the o-nitrobenzyl grou...
The manufacture of thin self-supporting 238U foils☆

Abstract A method is described for the manufacture of self-supporting 238U foils of thickness within the range 400−1400 μg cm−2.
MSIS‐86 Thermospheric Model

The MSIS-86 empirical model of thermospheric temperature, density and composition uses new temperature and composition data from the Dynamics Explorer satellite to improve the representation of polar region morphology over that in the MSIS-83 model. Terms were added or changed to better represent seasonal variations in the polar regions under both quiet and magnetically disturbed conditions. Local time variations in the magnetic activity effect were added. In addition a new species, atomic nitrogen, was added to the previous list of N2, O2, He, O, H, and Ar covered by the model.
Photoemission Studies of CdTe

CdTe photoemission absolute energies determined by correlating electron energy distribution structure with structure in optical data
A study of blind drawing practice: creating graphical information without the visual channel

Existing drawing tools for blind users give inadequate contextual feedback on the state of the drawing, leaving blind users unable to comprehend and successfully produce graphical information. We have investigated a tactile method of drawing used by blind users that mimics drawing with a pencil and a paper. Our study revealed a set of properties that must be incorporated into drawing tools for blind users, including giving feedback for relocating important points, determining angles, and communicating the overall structure of the drawing. We describe a grid- based model that provides these properties in a primitive- based 2D graphics environment, and we introduce its use in drawing and other graphical interactions.
Using Structural Analysis of Social Behavior (SASB) measures of self- and social perception to give interpersonal meaning to symptoms: anxiety as an exemplar.

Current symptom-based diagnosis, although important, lacks theoretical underpinning that might give meaning to psychiatric symptoms. The structural analysis of social behavior (SASB) fills this void, operationalizing interpersonal theory for investigation of relational aspects of psychopathology. To provide an example of how SASB may be utilized to this end, participants with (n = 40) and without (n = 40) uncontrollable worry and anxiety completed SASB Intrex Questionnaires to explore self-perceptions and perceptions of strangers in a social interaction task. Based on SASB principles and past research on familial factors in childhood anxiety, it was hypothesized that self- and other perceptions would discriminate participant groups along the lines of disrupted and normal attachment. To demonstrate the versatility of SASB, analyses incorporated indexes of varying specificity. Largely, results supported predictions, suggesting the sensitivity of SASB Intrex to assess social perceptions even in a first-meeti...
Liquefaction Sand Boils in San Francisco during 1989 loma prieta earthquake

This paper presents and analyzes the observations of the sand boils that emerged in the Marina District of San Francisco after the Loma Prieta Earthquake of October 17, 1989. The sand boils were located within the boundary of an old lagoon, the periphery of which was severely damaged in the 1906 San Francisco earthquake. During the 1989 Loma Prieta Earthquake, the soils underlying the Marina District amplified the ground motion as in 1906 and caused the liquefaction of the superficial sandy materials that were used to fill the old lagoon in 1915. Damage in the Marina District was concentrated along the edges of the old lagoon. The sand boils left behind by liquefaction were useful to delineate the liquefied area and to understand the ground displacement in the Marina District. The sand boils covered uniformly the liquefied area that experienced lateral spreading and settlement. The present work also indicates the high damage potential of transition zones between liquefiable and nonliquefiable soils.
A self-calibrating PARACEST MRI contrast agent that detects esterase enzyme activity

The CEST effect of many PARACEST MRI contrast agents changes in response to a molecular biomarker. However, other molecular biomarkers or environmental factors can influence CEST, so that a change in CEST is not conclusive proof for detecting the biomarker. To overcome this problem, a second control CEST effect may be included in the same PARACEST agent, which is responsive to all factors that alter the first CEST effect except for the biomarker to be measured. To investigate this approach, a PARACEST MRI contrast agent was developed with one CEST effect that is responsive to esterase enzyme activity and a second control CEST effect. The ratio of the two CEST effects was independent of concentration and T1 relaxation, so that this agent was self-calibrating with respect to these factors. This ratiometric method was dependent on temperature and was influenced by MR coalescence as the chemical exchange rates approached the chemical shifts of the exchangable protons as temperature was increased. The two CEST effects also showed evidence of having different pH dependencies, so that this agent was not self-calibrating with respect to pH. Therefore, a self-calibrating PARACEST MRI contrast agent can more accurately detect a molecular biomarker such as esterase enzyme activity, as long as temperature and pH are within an acceptable physiological range and remain constant. Copyright © 2010 John Wiley & Sons, Ltd.
Low-energy ground-state electron/positron source

Abstract The confinement of electrons and the partial thermalization of their energies has been observed in a prototype cryogenic source in which the energy of charged particles can be thermalized to 4° K.
Integral and peripheral protein composition of the apical and basolateral membrane domains in MDCK cells.

Selective biotinylation of the apical or basolateral domains of confluent MDCK monolayers grown on polycarbonate filters with a water soluble biotin analog, sulfo-NHS-biotin, was employed to reveal strikingly distinct patterns of endogenous “peripheral” and “integral” membrane proteins. “Peripheral” proteins were found to be approximately fivefold more abundant with this procedure than “integral” membrane proteins, both on the apical and on the basolateral surface. The distinct apical and basal patterns were shown to depend upon the integrity of the monolayer; when the tight junctions were disrupted by preincubation in calcium-depleted medium, the patterns appeared practically indistinguishable. Two-dimensional gel electrophoresis demonstrated that only a very small percentage of the biotinylated proteins were found in similar amounts on both apical and basolateral domains. These results indicate that the sorting mechanisms that segregate apical and basolateral epithelial proteins are very strict. The simple procedure described here has clear advantages over other methods available to label apical and basal epithelial surface domains, namely, higher accessibility of the biotin probe to the basolateral membrane, possibility of purifying biotinylated proteins via immobilized streptavidin and minimal exposure of the researcher to isotopes. It should be very useful in characterizing the apical and basolateral protein compositions of other epithelial cells and in studies on the development of epithelial cell polarity.
Thermo-mechanically coupled superelastic response of initially-textured Ti-Ni sheet

Abstract A three-dimensional crystal-mechanics based model for the thermo-mechanically coupled superelastic response of initially-textured polycrystalline shape-memory materials is used to simulate the response of Ti-Ni shape-memory alloy in sheet form. Both manifestations of superelasticity: stress-strain response at a fixed temperature, and strain-temperature response at a fixed stress have been experimentally studied. The model, when suitably numerically implemented and calibrated, is shown to accurately predict the anisotropic superelastic response of tension specimens which were cut along different directions to the rolling direction of the sheet. Also, the strain-temperature cycling experiments under different constant axial stresses are predicted with reasonable accuracy. The effects of self-heating and cooling due to the exothermic and endothermic nature of the austenite-to-martensite and martensite-to-austenite transformations were investigated by performing superelastic tension experiments at strain rates which are high enough to result in non-isothermal testing conditions. The thermo-mechanically coupled theory is able to capture the resulting inhomogenous deformation associated with the nucleation and propagation of transformation fronts, and also the ‘apparent hardening’ of the nominal stress-strain curves observed in the experiments.
Segregation of NGF receptor in sensory receptors, nerves and local cells of teeth and periodontium demonstrated by EM immunocytochemistry

Nerve growth factor receptor immunoreactivity (NGFR-IR) in sensory nerves and somatosensory receptors of adult rat dental and periodontal tissue was analysed using a monoclonal antibody (192-IgG) and electron microscopy. In dental and periodontal nerves, the unmyelinated axons and their Schwann cells had occasional labelling of their cell membranes, and myelinated axons had none. Dental free nerve endings in predentin had varied NGFR-IR: 15% were unlabelled, 25% had some axonal membrane NGFR-IR, and 60% had intense membrane label and cytoplasmic staining. In periodontal ligament there were two types of NGFR-IR somatosensory receptors: Ruffini mechanoreceptors had extensive NGFR-IR on apposed membranes of the terminal Schwann cell and nerve endings, but no labelling of the neural fingers which extended out into the ligament tissue; and thin fibres had intense membrane NGFR-IR and cytoplasmic stain. Non-neuronal NGFR-IR had cell specific patterns: perineurial and endoneurial cells and Ruffini terminal Schwann cells had NGFR-IR on cell membranes and inside numerous pinocytotic vesicles; Schwann cells along unmyelinated axons had NGFR-IR cell membrane intensities which varied depending on the NGFR-IR intensity of the enclosed axons; odontoblasts were unlabelled except at sites of contact with the NGFR-IR pulpal or neural cells; pulp fibroblasts in the subodontoblast zone had intense NGFR-IR all along their cell membrane; and ligament fibroblasts were unlabelled. The diverse NGFR-IR patterns described here suggest that there are specific categories of cellular expression and localization which correlate with somatosensory receptor type, and that specific patterns also characterize various non-neuronal cells in dental and periodontal tissue. Only the endoneurial cells, perineurial cells, and Ruffini terminal Schwann cells had NGFR-IR endocytotic vesicles, suggesting NGF internalization by high-affinity receptors.
Wnt/β-Catenin Signaling in Murine Hepatic Transit Amplifying Progenitor Cells

Background & Aims: Oval cells are postnatal hepatic progenitors with high proliferative potential and bipotent differentiation ability to become hepatocytes and cholangiocytes. Because Wnt/β-catenin signaling is a known regulatory pathway for liver development and regeneration, we studied the role of Wnt signaling in oval cells using a mouse model of chronic liver injury. Methods: A 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-enriched diet was used to stimulate oval cell proliferation. Livers were harvested for histologic analysis and determination of Wnt family gene expression by quantitative reverse transcription-polymerase chain reaction and in situ hybridization. The transgenic β-catenin reporter mouse (TOPGAL) was use to confirm canonical Wnt/β-catenin signal transduction in proliferating oval cells within atypical ductal proliferations (ADPs). Confocal fluorescence microscopy and immunohistochemistry was used to confirm colocalization of β-catenin with the oval cell antigen A-6. Results: Several Wnt ligands were significantly induced in the liver of DDC-fed mice and localized to proliferating cells in and adjacent to the ADPs. Oval cells isolated from DDC-fed mouse livers showed the presence of active β-catenin in the nucleus along with cell-cycle entry in response to purified Wnt3a in vitro. Moreover, Wnt3a-induced β-catenin/T-cell factor/lymphoid enhancer factor (TCF/LEF) transcriptional activation was quantified by TCF/LEF luciferase reporter assays. Conclusions: From these data, we conclude that oval cells respond to Wnt ligands (Wnt3a) in vitro with an increase in amino-terminus dephosphorylated β-catenin and cell-cycle entry and that canonical Wnt/β-catenin/TCF signaling is active in proliferating facultative hepatic progenitor cells in vivo. These findings may lend insight to the consequences of increased canonical Wnt signaling during periods of chronic liver injury.
Developing Smoking Cessation Programs for Chronically Ill Teens: Lessons Learned from Research with Healthy Adolescent Smokers

Objective Medically fragile teens who smoke need access to smoking cessation programs, because they are at even higher risk than their healthy peers for smoking-related complications. Methods To date, no studies on the outcome of smoking cessation programs for medically ill teens have been conducted. To suggest directions for future research, we turn to the literature on smoking cessation in the general population of teens and occasionally to the literature on adult smokers. Results Four areas are explored: (a) the prevalence of unaided cessation in healthy teens; (b) the outcomes of various treatments for smoking cessation in healthy adolescents; (c) special issues that should be considered when designing programs for medically ill teens; and (d) lessons learned from previous research. Conclusions Medically ill teens face a number of medical, emotional, social, and developmental challenges that can affect the quitting process. Research is sorely needed to address the unique needs of this population.