cssi/SciSciGPT-SciSciNet huggingface dataset:
Obstructive Sleep Apnea and Pain Intensity in Young Adults

Rationale: Prior research studies on the association of obstructive sleep apnea (OSA) and pain intensity have examined older patients; there is a need to understand the relationship between OSA and...
Elevated CO2 Levels Delay Skeletal Muscle Repair by Increasing Fatty Acid Oxidation

Muscle dysfunction often occurs in patients with chronic obstructive pulmonary diseases (COPD) and affects ventilatory and non-ventilatory skeletal muscles. We have previously reported that hypercapnia (elevated CO2 levels) causes muscle atrophy through the activation of the AMPKα2-FoxO3a-MuRF1 pathway. In the present study, we investigated the effect of normoxic hypercapnia on skeletal muscle regeneration. We found that mouse C2C12 myoblasts exposed to elevated CO2 levels had decreased fusion index compared to myoblasts exposed to normal CO2. Metabolic analyses of C2C12 myoblasts exposed to high CO2 showed increased oxidative phosphorylation due to increased fatty acid oxidation. We utilized the cardiotoxin-induced muscle injury model in mice exposed to normoxia and 10% CO2 for 21 days and observed that muscle regeneration was delayed. High CO2-delayed differentiation in both mouse C2C12 myoblasts and skeletal muscle after injury and was restored to control levels when cells or mice were treated with a carnitine palmitoyltransfearse-1 (CPT1) inhibitor. Taken together, our data suggest that hypercapnia leads to changes in the metabolic activity of skeletal muscle cells, which results in impaired muscle regeneration and recovery after injury.
Affine reduced-order model for radiation transport problems in cylindrical coordinates

Abstract This article focuses on parametric reduced-order models to decrease the computational cost of large-scale neutron transport problems in the atmosphere. The atmospheric humidity content and neutron source spectrum are considered as uncertain parameters throughout the problem. We first present our full-order model, including an axisymmetric S N transport methodology, a geopotential model for computing the thermophysical properties of the atmosphere, and a support vector regression method for rapidly generating one-group cross sections at every point. Then, reduction of the full-order problem using the POD-Galerkin and least-squares POD-Petrov-Galerkin methods is presented. The reduced-order models implemented introduce mean relative errors between 0.06% and 0.4% with acceleration factors between 3.6 × 10 3 - 8.4 × 10 4 , respectively.
Small leap forward: Emergence of new economic elites

The collapse of Communism is often explained as resulting primarily from those economies' inherent inability to adjust to global change, to provide sustained economic growth, and to satisfy increasing consumer demand. Thus, many observers have expected rapid and farreaching structural changes in the economy and the quick replacement of economic leadership during the transition from state socialism.
The hepatitis A virus polyprotein expressed by a recombinant vaccinia virus undergoes proteolytic processing and assembly into viruslike particles.

Hepatitis A virus (HAV) contains a single-stranded, plus-sense RNA genome with a single long open reading frame encoding a polyprotein of approximately 250 kDa. Viral structural proteins are generated by posttranslational proteolytic processing of this polyprotein. We constructed recombinant vaccinia viruses which expressed the HAV polyprotein (rV-ORF) and the P1 structural region (rV-P1). rV-ORF-infected cell lysates demonstrated that the polyprotein was cleaved into immunoreactive 29- and 33-kDa proteins which comigrated with HAV capsid proteins VP0 and VP1. The rV-P1 construct produced a 90-kDa protein which showed no evidence of posttranslational processing. Solid-phase radioimmunoassays with human polyclonal anti-HAV sera and with murine or human neutralizing monoclonal anti-HAV antibodies recognized the rV-ORF-infected cell lysates. Sucrose density gradients of rV-ORF-infected cell lysates contained peaks of HAV antigen with sedimentation coefficients of approximately 70S and 15S, similar to those of HAV empty capsids and pentamers. Immune electron microscopy also demonstrated the presence of viruslike particles in rV-ORF-infected cell lysates. Thus, the HAV polyprotein expressed by a recombinant vaccinia virus demonstrated posttranslational processing into mature capsid proteins which assembled into antigenic viruslike particles. Images
Communication and Human Performance

The communication to which the present paper refers is the flow of information in and out of the human operator while he is performing a well-defined task. The steps in this process, the types of measures required in its analysis, and some recent data in human information processing are outlined. The paper ends with a brief evaluation of the function and the future of computer simulation in improving man-machine communications.
Computing with strategic agents

This dissertation studies mechanism design for various combinatorial problems in the presence of strategic agents. A mechanism is an algorithm for allocating a resource among a group of participants, each of which has a privately-known value for any particular allocation. A mechanism is truthful if it is in each participant's best interest to reveal his private information truthfully regardless of the strategies of the other participants. First, we explore a competitive auction framework for truthful mechanism design in the setting of multi-unit auctions, or auctions which sell multiple identical copies of a good. In this framework, the goal is to design a truthful auction whose revenue approximates that of an omniscient auction for any set of bids. We focus on two natural settings---the limited demand setting where bidders desire at most a fixed number of copies and the limited budget setting where bidders can spend at most a fixed amount of money. In the limit demand setting, all prior auctions employed the use of randomization in the computation of the allocation and prices. Randomization in truthful mechanism design is undesirable because, in arguing the truthfulness of the mechanism, we employ an underlying assumption that the bidders trust the random coin flips of the auctioneer. Next, we consider abandoning truthfulness in order to improve the revenue properties of procurement auctions, or auctions that are used to hire a team of agents to complete a task. We study first-price procurement auctions and their variants and argue that in certain settings the payment is never significantly more than, and sometimes much less than, truthful mechanisms. Then we consider the setting of cost-sharing auctions. In a cost-sharing auction, agents bid to receive some service, such as connectivity to the internet. A subset of agents is then selected for service and charged prices to approximately recover the cost of servicing them. We ask what can be achieved by cost-sharing auctions satisfying a strengthening of truthfulness called group-strategyproofness. Finally, we study centralized two-sided markets, or markets that form a matching between participants based on preference lists. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.) (Abstract shortened by UMI.)
Secularism, Liberalism, and Relativism

This chapter explores the issue of relativism in ethics and politics by looking to a specific form of ethical and political conflict – secular liberalism versus identify politics mobilized on religious identity – and asking whether only certain forms of “externalism” about reason and value (in Bernard William’s sense of that term ) can repudiate relativism. It is argued that this need not be so. There is scope for turning one’s back on relativism even within what Williams calls “internalism” about reason about reason and value.
Synthesizing physically-realistic environmental models from robot exploration

In previous work [4] a framework was demonstrated that allows an autonomous robot to automatically synthesize physically-realistic models of its own body. Here it is demonstrated how the same approach can be applied to empower a robot to synthesize physically-realistic models of its surroundings. Robots which build numerical or other nonphysical models of their environments are limited in the kinds of predictions they can make about the repercussions of future actions. In this paper it is shown that a robot equipped with a self-made, physicallyrealistic model can extrapolate: a slow-moving robot consistently predicts the much faster top speed at which it can safely drive across a terrain.
The Relationship Between Age, Anxiety, and Depression in Older Adults With Cancer

By the year 2030 older adults will account for 20% of the U.S. population1, almost doubled from 20052. Cancer is a disease of aging; over half of all cancer diagnoses and almost three quarters of cancer deaths occur in patients older than 653. The development and progression of comorbid conditions and the accelerating loss of spouses, friends and loved ones may make older adults with cancer more vulnerable to anxiety and depression4. The rate of anxiety in older oncology patients has been cited to be as high as 23%5, while depression in older oncology patients ranges from 17–26%6. Despite the various challenges faced by geriatric oncology patients, recent studies have suggested that age may actually serve as a protective factor against cancer-related psychological distress7. Distress is an umbrella term encompassing factors such as quality of life, anxiety, and depression. When teasing apart distress, age may not buffer against all facets of distress. For example, in a study of older men (age 50 and older) with prostate cancer, while increased age was associated with reduced anxiety (p < 0.01), increased age was also associated with greater depressive symptoms (p < .01)8. The percentage of men scoring above the cut-off for depression consistently increased with age. Despite the burgeoning geriatric oncology population and the importance of understanding how age may be related to constructs such as anxiety and depression, there has been limited further exploration of changes in anxiety and depression related to age within an older population of patients. Depression and anxiety are associated with poorer treatment outcomes9, reduced ability to make treatment decisions, decreased adherence to lengthy treatment and longer hospital stays10–14, and suicide1,15. Given the serious consequences of unrecognized and untreated depression and anxiety, it is important for clinicians to know if older adults are more vulnerable, and which variables might serve as signals to screen for depression and anxiety among this population. The current study seeks to explore the relationship between age, anxiety and depression within an older oncology population. Based on the literature, we hypothesized that anxiety would decrease with age while depression would increase with age.
Complex survey data analysis: Estimation of standard errors using pseudostrata

A proper analysis of data from complex sample surveys requires special consideration for estimating standard errors. Special techniques and software packages are available, including Taylor series linearization (delta method), balanced re­ peated replication, and jackknife. Before their use, it is often necessary to make certain modifications in original data structure, to conform to computing method requirements. The most common modifi­ cation is to form pseudostrata by collapsing sub­ strata or partitioning a string of geographic clusters. This paper examines the performance of the delta method when it is applied to a complex community survey data set in which sequentially drawn clusters of households are partitioned to form pseudostrata. Standard errors of rates, regression coefficients, and odds ratios are compared with those computed from the variation of replicates built into the sample de­ sign. The results demonstrate that an analysis of complex survey data should use an appropriate method for estimating standard errors, and that pseudostrata would produce reasonable estimates of standard errors for rates and regression coeffi­ cients, with mixed results for odds ratios.
Induction of mouse CYP2J by pyrazole in the eye, kidney, liver, lung, olfactory mucosa, and small intestine, but not in the heart.

We have recently shown that rat CYP2J4 is inducible by pyrazole in liver, small intestine, and olfactory mucosa. The aim of the present study was to determine whether mouse CYP2Js are also inducible by pyrazole, which was known to induce CYP2A5 in mouse liver and kidney, but not in lung or olfactory mucosa. CYP2J proteins were detected in mouse liver, lung, kidney, heart, eye, olfactory mucosa, and small intestine by immunoblot analysis with an anti-CYP2J4 antibody. The microsomal level of the CYP2J4-related P450s in various mouse tissues ranked in the order of small intestine > olfactory mucosa > liver > kidney ≥ heart > lung > eye. Induction of the CYP2J proteins was observed in the eye, liver, lung, kidney, olfactory mucosa, and small intestine, but not in the heart, after daily i.p. injection of pyrazole at 120 or 200 mg/kg for 3 days. CYP2J proteins were induced similarly in C57BL/6 and DBA/2 mice. CYP2A5 was detected in the small intestine in addition to liver and olfactory mucosa; however, treatment with pyrazole induced CYP2A5 in the liver, but not in the olfactory mucosa or the small intestine. Induction of CYP2J mRNAs was also observed by RNA blot analysis with a CYP2J4 cDNA probe. RNA-polymerase chain reaction analysis showed that, in both untreated and pyrazole-treated mice, CYP2J5 was expressed in the kidney and liver, but not in the other tissues examined, whereas CYP2J6 was detected in all tissues examined. The different tissue selectivities in CYP2A5 and CYP2J induction by pyrazole suggest involvement of different regulatory mechanisms.
Routine histopathology in uncomplicated sinus surgery: is it necessary?

Objective To evaluate the incidence of occult pathology in routine, uncomplicated endoscopic sinus surgery, and to suggest guidelines for when to send specimens for histopathologic exam. Study design and setting Retrospective analysis of case records of 790 patients who underwent 868 endoscopic sinus surgeries at a tertiary care center from 1986 to 2003. Indications were chronic sinusitis, recurrent acute sinusitis, nasal polyposis, or combinations of these diagnoses. All cases were considered routine and did not involve preoperative suspicion of neoplasm or other complicating factors. Charts were reviewed for surgical indication, patient age, laterality of disease, history of prior sinus surgery, intraoperative suspicion of tumor, and final histopathology. Results In 868 cases of endoscopic sinus surgery, occult neoplasm was diagnosed in 2 patients (0.23%). In one patient, the initial surgery cured the lesion. Final histopathology of the remaining 866 (99.8%) specimens was consistent with inflammation and/or nasal polyposis. In 121 cases of unilateral sinusitis, none was positive for neoplasm. In 277 cases involving bilateral nasal polyposis and 13 involving unilateral polyposis, no neoplasms were found. Intraoperative suspicion of neoplasm occurred in 12 cases, with all specimens read as consistent with sinusitis and/or polyposis. Conclusions Histopathologic review of every specimen obtained in routine sinus surgery for sinusitis and/or nasal polyposis is not indicated. Submission of specimen is indicated in routine cases when: 1) there is intraoperative suspicion of tumor, 2) unilateral nasal polyposis is present, 3) unilateral sinus opacification is present, and 4) additional diagnostic information is needed (eg, presence of eosinophils, fungal forms, etc.). Significance Establishes a safe and reasonable standard of care, with potential cost savings and medico-legal ramifications.
Genetic and environmental influences on illicit drug use and tobacco use across birth cohorts.

Background. The prevalence of use of many psychoactive substances has changed considerably in recent years. While genetic factors impact on overall risk for substance use, we know little about whether the etiological importance of these factors differs across birth cohorts. One theory, which postulates that heritability of deviant traits increases in permissive environments, predicts a positive relationship across cohorts between prevalence and heritability of substance use.Method. The lifetime history of use of tobacco, cannabis, cocaine, sedatives and stimulants were assessed in 4826 twins from male–male and female–female pairs born in Virginia from 1934 to 1974. Using empirical methods based on prevalence by birth year, these twins were divided into three cohorts for each substance (e.g. for cannabis 1934–1953, 1954–1968 and 1969–1974). Structural equation modeling was performed using the Mx software package.Results. Prevalence rates for psychoactive substance use differed substantially across cohorts, most markedly for cocaine, sedatives and stimulants, which were highest in the 1958–1963 cohort. However, for all substances, the best-fit model constrained estimates of the etiological role of genetic and environmental risk factors to be equal across both sex and cohort.Conclusions. We found no evidence in this sample for any systematic relationship between heritability and prevalence of psychoactive substance use – which should be a rough index of drug availability and/or acceptability. This sample had reasonable power to detect large changes in heritability across cohorts and at least moderate power to detect relatively small changes.
Backbone assignment of the catalytic core of a Y-family DNA polymerase

Sulfolobus solfataricus DNA polymerase IV (Dpo4), a model Y-family DNA polymerase, bypasses DNA lesions. Here, we report the assignments for the backbone nitrogen, carbon, and amide proton NMR signals of Dpo4’s catalytic core consisting of the finger, palm, and thumb domains. Our work provides the basis for further NMR spectroscopic studies of the interactions among Dpo4, DNA, and an incoming nucleotide.
An intense Z-pinch aurora horn mapped by surveys of recordings from antiquity

Summary form only given. The GPS locations and survey field-of view data of some four million rock carvings at petroglyph sites world-wide is allowing the visual reconstruction of a sub-gigaampere auroral Z-pinch column whose plasma flow was bent inward towards the south polar axis, subsequently flowing around the Earth. This data is analyzed by means of two and three dimensional satellite and aerial orthophotography with side looking radar sets allowing near ground level to vertical inspection of all-terrain views from each site. It is found that petroglyphs, shown to be depictions of synchrotron light from MHD instabilities, possess southerly preferred orientations and right-ascension-declination information. The computer model of the reconstructed Z-pinch, via high-speed, high-fidelity three-dimensional PIC simulations, add new petroglyph comparisons as shown by oblique views of the incoming Z-pinch. The reconstruction figure shows the incoming 56 current sheath with two pinches (egg-shaped plasmoids) approximately 300,000 km from Earth. Closer in, the 56 currents have merged to 28. Two 'bonnet' petroglyphs from the plethora of such at the Columbia River Gorge, found at the same locations as the 'Stonehenge' variety petroglyphs are also shown
Part design using manufacturing features

This paper presents a methodology by which manufacturability data is used to drive the design process. The system allows a designer to determine the features to be considered. He provides the basic geometric parameters for each feature and passes them to the modeling system for instantiations. Tolerances and surface finish allow the system to derive manufacturing implications used by the designer to review the design. The physical parameters, in addition to the processing information, lead to an integrated model which may be used by both the designer and the manufacturing personnel. This procedure may be invoked at any level of the design process and contribute to a final manufacturable design. The philosophy employed in the development of this work is to define manufacturing features as instances of generic ones with specific properties and processing methods. The design features obtain their geometric superclasses from a commercially available package of solid primitives thus allowing for the part to be graphically displayed.
Potent Circadian Effects of Dim Illumination at Night in Hamsters

Conventional wisdom holds that the circadian pacemaker of rodents and humans is minimally responsive to light of the intensity provided by dim moonlight and starlight. However, dim illumination (<0.005 lux) provided during the daily dark periods markedly alters entrainment in hamsters. Under dimly lit scotophases, compared to completely dark ones phases, the upper range of entrainment is increased by ∼4 h, and re‐entrainment is accelerated following transfer from long to short day lengths. Moreover, the incidence of bimodal entrainment to 24 h light:dark:light:dark cycles is increased fourfold. Notably, the nocturnal illumination inducing these pronounced effects is equivalent in photic energy to that of a 2 sec, 100 lux light pulse. These effects may be parsimoniously interpreted as an action of dim light on the phase relations between multiple oscillators comprising the circadian pacemaker. An action of dim light distinct from that underlying bright‐light phase‐resetting may promote more effective entra...
Use of the aspartate aminotransferase to platelet ratio index to follow liver fibrosis progression in infants with short gut.

Abstract Background Infants with parenteral nutrition dependence may develop liver dysfunction and progress to liver failure requiring transplantation. The aspartate aminotransferase–to-platelet ratio index (APRI) has good correlation with liver fibrosis progression in adults. This study applies APRI scoring to parenteral nutrition-dependant, short-gut infants to determine hepatic fibrosis progression. Methods Laboratory values and biopsies were collected from initial intestinal resection (time 0) up to transplantation (end). Fibrosis scoring ranged from F0 (normal) to F4 (cirrhosis). Children were divided into 3 groups: (1) isolated intestine; and combined liver/intestine with gestational age (2) 34 weeks or greater and (3) 30 weeks or less. Liver function values over time, including calculated APRI, were analyzed as predictors of fibrosis. Results Fifteen children who had 33 biopsies were included. Median APRI by fibrosis grade was F ≤ 2: 1.88, F3: 3.23, and F4: 14.16 ( P P = .04). Conclusion Progression of APRI up to 60 days initially demonstrates similar values among study groups, but over time the score distinguishes those children with impending liver cirrhosis and differentiates fibrosis grade and study group.
X-ray crystallographic structure of the angiogenesis inhibitor, angiostatin, bound to a peptide from the group A streptococcal surface protein PAM

The crystal structure of the human Pg-derived angiogenesis inhibitor, angiostatin, complexed to VEK-30, a peptide from the group A streptococcal surface protein, PAM, was determined and refined to 2.3 A resolution. This is the first structure of angiostatin bound to a ligand and provides a model of the interaction between Pg and streptococcal-derived pathogenic proteins. VEK-30 contains a "through-space isostere" for C-terminal lysine, wherein Arg and Glu side chains, separated by one helical turn, bind within the bipolar angiostatin kringle 2 (K2) domain lysine-binding site. VEK-30 also makes several contacts with K2 residues that exist outside of the canonical LBS and are not conserved among the other Pg kringles, thus providing a molecular basis for the selectivity of VEK-30 for K2. The structure also shows that Pg kringle domains undergo significant structural rearrangement relative to one another and reveals dimerization between two molecules of angiostatin and VEK-30 related by crystallographic symmetry. This dimerization, which exists only in the crystal structure, is consistent with the parallel coiled-coil full-length PAM dimer expected from sequence similarities and homology modeling.
Extracorporeal Shock Wave Lithotripsy for the Treatment of Urinary Calculi in the Elderly

Renal calculus in the elderly patient is associated with the same symptoms and risks as in other patient populations. With the recent development of extracorporeal shock wave lithotripsy (ESWL), many older patients can now be treated for renal calculi. The Department of Urology at the University of Iowa Hospitals and Clinics has performed 107 ESWL treatments on a total of 96 patients over 70 years of age. This represents 1over 12% of all patients treated at our institution. No deaths related to ESWL treatment have occurred in this group, nor has increased morbidity been observed in comparison to all patients treated. In spite of the increased age and associated medical problems of this patient population, ESWL offers a safe and effective means of treating upper tract urinary calculi in the geriatric age group.
Instructional supervision from a situational perspective

Abstract This article explores the ramifications of a situational perspective for instructional supervision. Included is a brief historical overview of supervision. A view of context as mutually constructed by participants—students, teachers, supervisors, and other administrators, in this case—provides the underpinning for a new approach, tentatively termed Situational Supervision. From a situational perspective, supervisors and teachers would attempt to affect the contexts of teaching and learning. Implications for the nature of school, teachers' and supervisors' roles, and other professional relationships are discussed. Participatory, action-oriented research is suggested as a means to understand and change the contexts of learning.
On observer-based Active Vibration Control of two-inertia systems

The two-inertial system is a typical motion control problem with compliance between the motor and load, where the resonance makes it very challenging to regulate the load response and stabilize the motor at the same time. Concerned with setpoint tracking, disturbance rejection, and internal stability, an observer based Active Vibration Control solution is formulated, tested and analyzed in this paper. Simulation results show that the proposed method is an effective solution in obtaining desirable responses from both the motor and the load sides simultaneously. Furthermore, the controller is easy to implement and to tune, with much tolerance of internal dynamic variations and external disturbances. Finally, comparing with the existing solutions, the wear and tear of motors and transmission is much reduced.
Induced current in a Bi2Sr2CaCu2Ox superconductor tube

Abstract Experiments were conducted to measure the induced current in a high-temperature Bi 2 Sr 2 CaCu 2 O x superconductor tube that was excited by an external coil driven by an AC sinusoidal voltage source. Experimental data were obtained for tests without and with an iron core inside the superconductor tube. All of the tests were conducted at 77 K and an excitation frequency of 60 Hz. The results showed that immediately after field penetration, the induced current (RMS value) decreased from the critical current, then began to recover, and eventually approached the critical current again at a high excitation current. Before field penetration, the induced current was mainly shielding current, which is 180 ° out of phase with the excitation current. After field penetration, the induced current consisted of two parts, a shielding current that led the excitation current by 180 ° and an inductive current (Faraday's law) that led the excitation current by 90 °. The presence of the iron core amplified the drop in induced current immediately after field penetration and delayed the growth of the inductive current after field penetration.
Endothelial damage associated with intraocular lenses.

Summary We examined the corneal endothelium of five patients with the clinical specular microscope before and at intervals after a combined cataract extraction and intraocular lens implantation. There was a severe loss of endothelial cells postoperatively in all five patients despite clear, thin corneas. We observed no significant endothelial regeneration (increased number of cells) or continued cell loss during 15 weeks of postoperative observation. The clinical specular microscope was useful in assessing the endothelial effects of ocular surgical procedures.
Dissecting the role of putative CD81 binding regions of E2 in mediating HCV entry: Putative CD81 binding region 1 is not involved in CD81 binding

Hepatitis C virus (HCV) encodes two transmembrane glycoproteins E1 and E2 which form a heterodimer. E1 is believed to mediate fusion while E2 has been shown to bind cellular receptors including CD81. In this study, alanine substitutions in E2 were generated within putative CD81 binding regions to define residues critical for viral entry. The effect of each mutation was tested by challenging susceptible cell lines with mutant HCV E1E2 pseudotyped viruses generated using a lentiviral system (HCVpp). In addition to assaying infectivity, producer cell expression and HCVpp incorporation of HCV E1 and E2 proteins, CD81 binding profiles, and E1E2 association of mutants were examined. Based on these characteristics, mutants either displayed wt characteristics (high infectivity [≥ 50% of wt HCVpp], CD81 binding, E1E2 expression, association, and incorporation into viral particles and proper conformation) or segregated into 4 distinct low infectivity (≤ 50% of wt HCVpp) mutant phenotypes: (I) CD81 binding deficient (despite wt E1E2 expression, incorporation and association and proper conformation); (II) CD81 binding competent, but lack of E1 detection on the viral particle, (despite adequate E1E2 expression in producer cell lysates and proper conformation); (III) CD81 binding competent, with adequate E1E2 expression, incorporation, association, and proper E2 conformation (i.e. no defect identified to explain the reduced infectivity observed); (IV) CD81 binding deficient due to disruption of E2 mutant protein conformation. Although most alanine substitutions within the putative CD81 binding region 1 (amino acids 474–492) displayed greatly reduced HCVpp infectivity, they retained soluble CD81 binding, proper E2 conformation, E1E2 association and incorporation into HCVpp suggesting that region 1 of E2 does not mediate binding to CD81. In contrast, conformationally correct E2 mutants (Y527 and W529) within the second putative CD81 binding region (amino acids 522–551) disrupted binding of E2 to CD81-GST, suggesting that region 2 is critical to CD81 binding. Likewise, all conformationally intact mutants within the third putative CD81 binding region (amino acids 612–619), except L615A, were important for E2 binding to CD81-GST. This region is highly conserved across genotypes, underlining its importance in mediating viral entry.
Effects of chronic nicotinic ligand exposure on functional activity of nicotinic acetylcholine receptors expressed by cells of the PC12 rat pheochromocytoma or the TE671/RD human clonal line.

: Studies were conducted to ascertain the temporal and dose-dependent effects of nicotinic ligand exposure on functional activity of different nicotinic acetylcholine receptor (nAChR) subtypes, as expressed by cells of the PC12 rat pheochromocytoma (ganglia-type nAChR) or the TE671/RD human (muscle-type nAChR) clonal line. Chronic (3–72-h) agonist (nicotine or carbamylcholine) treatment of cells led to a complete (TE671) or nearly complete (PC12) loss of functional nAChR responses, which is referred to as “functional inactivation.”Some inactivation of nAChR function was also observed for the nicotinic ligands d-tubocurarine (d-TC), mecamylamine, and decamethonium. Half-maximal inactivation of nAChR function was observed within 3 min for TE671 cells and within 10 min for PC12 cells treated with inactivating ligands. Functional inactivation occurred with dose dependencies that could not always be reconciled with those obtained for acute agonist activation of nAChR function or for acute inhibition of those responses by d-TC, decamethonium, or mecamylamine. Treatment of TE671 or PC12 cells with the nicotinic antagonist pancuronium or alcuronium alone had no effect on levels of expression of functional nAChRs. However, evidence was obtained that either of these antagonists protected TE671 cell muscle-type nAChRs or PC12 cell ganglia-type nAChRs from functional inactivation on long-term treatment with agonists. Recovery of TE671 cell nAChR function following treatment with carbamylcholine, nicotine, or d-TC occurred with half-times of 1–3 days whether cells were maintained in situ or harvested and replated after removal of ligand. By contrast, 50% recovery of functional nAChRs on PC12 cells occurred within 2–6 h after drug removal. In either case the time course for recovery from nAChR functional inactivation is much slower than recovery from nAChR “functional desensitization,”which is a reversible process that occurs on shorter-term (0–5-min) agonist exposure of cells. These results indicate that ganglia-type and muscle-type nAChRs are similar in their sensitivities to functional inactivation by nicotinic ligands but differ in their rates of recovery from and onset of those effects. The ability of drugs such as the agonists d-TC, decamethonium, and mecamylamine to induce functional inactivation may relate to their activities as partial/full agonists, channel blockers, and/or allosteric regulators. Effects of drugs such as pancuronium and alcuronium are likely to reflect simple competitive inhibition of primary ligand binding at functional activation sites. Agonist-induced functional inactivation of TE671 cell nAChRs occurs under conditions previously shown to induce increases in numbers of nAChR ligand binding sites expressed on the cell surface and in total membrane pools and contrasts with coordinate down-regulation of nAChR ligand binding and function following chronic agonist treatment of nAChR-bearing cells in the periphery.
Intercommunication of processors and memory

Many computer systems include one or more high transfer rate secondary storage devices in addition to numerous input-output (I/O) devices. When the processors which manage these devices (frequently referred to as I/O controllers or channels), together with the central processing unit (CPU), communicate almost exclusively with a single primary memory, as in the configuration illustrated in Figure 1, the problem of providing these processors with adequate data transfer capability becomes formidable. Ideally, each processor should be able to transfer a datum to or from primary memory at its convenience without regard to the ability of the memory to accept or supply the datum at that particular moment, or the ability of the processor-to-memory transfer path (memory bus) to effect the transfer. Unfortunately, economic and technical considerations dictate that memory systems of the capability implied must be relegated to the role of standards with which more practical systems may be compared. With practical memory systems, the rate at which data can be transferred between processors and primary memory is limited by the transfer capabilities, or bandwidths, of the memory itself and of the memory busses over which the transfers are made. Furthermore, since the memory system is shared by several processors, care must be taken to keep performance from being degraded excessively by interference caused by simultaneous attempts on the part of several processors to utilize a facility, such as a memory bus, which is capable of handling only a single data transfer at any given moment.
Synthesis of dibenzo[b, f]silepins

Abstract The reaction of o,o′-dilithiobibenzyl with substituted silicon halides results in the formation of previously unreported 10,11-dihydro-5H-dibenzo[b,f]silepins. The bromination of the dihydrodibenzosilepins followed by dehydrobromination with potassium acetate and 1,5-diazabicylo[4.3.0]non-5-ene results in the formation of the symmetrical dibenzosilepin derivatives. The spectral data for these new compounds are discussed.
Inelastic electron scattering from organic compounds

In calculations of possible superconductivity in a system, knowledge of certain matrix elements determines whether or not bound electron pairs can exist and thus lead to superconductivity. These matrix elements involve ground and excited state wave functions. We are presently attempting to experimentally determine such matrix elements in certain organic compounds by measuring differential cross sections for inelastic electron scattering. Such cross sections involve the square of the matrix elements of interest. To do this we are using a crossed beam technique with an electrostatic electron spectrometer for the production of the incident electron beam and analysis of the scattered beam. The apparatus is described, as well as the present status of the experiment.
The effect of temperature and wavelength on the measurement of creatinine with the jaffe procedure

Studies were conducted to determine the effect of temperature and wavelength on the absorbance of alkaline solutions of picric acid in the presence and absence of creatinine. Absorbance values of an alkaline solution of picric acid were found to be influenced by temperature. At wavelength settings between 475 and 520 nm, absorbance values increased as the temperature increased. The magnitude of the thermochromic response (temperature-induced increase in absorbance) was found to be a function of wavelength: At 490 nm, the response was about three times greater than it was at 500 nm and about fifteen times greater than it was at 520 nm. Other experiments demonstrated that the response was: quantitatively related to picric acid concentration, reversible, rapid, and independent of creatinine concentration.
The macrocyclic domain of phorboxazole A. A stereoselective synthesis of the C1C32 macrolactone

A stereoselective synthesis of the C1C32 macrocyclic domain of phorboxazole A is described. Key steps have examined the convergent linkage of two major components for the formation of the C19C20 (E)-alkene, and the subsequent intramolecular (Z)-olefination at C2C3 for ring closure of the macrocycle.
A glucose oxidase reagent for maltase assay.

Abstract Inhibition of maltase contamination of glucose oxidase used for glucose assay is described, which provides a glucose oxidase reagent suitable for routine maltase assay of chromatographic fractions.
Stability and Photochemistry of Vitamin D2 in Model System

Oxidation of vitamin D 2 in a model system of 12% water and 88% acetone in the presence of 15 ppm riboflavin under light and dark was studied by measuring the depleted headspace oxygen. Riboflavin accelerated the oxidation of vitamin D 2 by singlet oxygen under light, but did not affect the vitamin D 2 oxidation under dark. The effect of 0 and 15 ppm riboflavin on the stability of vitamin D 2 during storage at 25 and 60°C was studied by measuring the contents of vitamin D 2 during 48h. Results indicated that photosensitized singlet oxygen oxidation of vitamin D 2 under light was temperature-independent, and triplet oxygen oxidation of vitamin D 2 both under light and in the dark was temperature-dependent.
Influence of nitroglycerin on collateral blood flow during acute ischaemia in the dog.

To investigate the effects of nitroglycerin on collateral blood flow 10 open chest dogs underwent coronary occlusion followed by nitroglycerin infusion (80 to 300 μ g·min−1) to lower mean systemic blood pressure by 20 mmHg, followed by phenylephrine infusion (10 to 40 μ g·min−1) to restore blood pressure to the pre-nitroglycerin level. Myocardial blood flow was measured with microspheres. The contribution of overlapping normal zone tissue in the ischaemic zone was evaluated with the balloon perfusion technique. Collateral flow was measured with microspheres in the most ischaemic tissue. In addition "load line" analysis was used to calculate collateral flow from retrograde flow. Nitroglycerin lowered blood flow to non-ischaemic tissue, and tended to lower blood flow to ischaemic tissue. Phenylephrine restored blood flow to the value after coronary occlusion. Load line analysis data was similar to data on myocardial blood flow from the microspheres. Collateral resistance changed little during the experiment. The effects of nitroglycerin on collateral blood flow are, thus, minimal. While it is possible that under special circumstances there may be some decrease in collateral resistance, the bulk of data from this study and others do not support the idea that systemic infusion of nitroglycerin in the setting of an acute myocardial infarction will affect collateral flow.
Dynamic equations in descriptor form

This paper studies a general form of sets of equations that is often the product of problem formulation in large-scale systems, especially when the equations are expressed in terms of the natural describing variables of the system. Such equations represent a broad class of time-evolutionary phenomena, and include as special cases ordinary static equations of arbitrary dimension, ordinary state-space equations, combinations of static and dynamic equations, and noncausal systems. The main thrust of the paper is to show (for sets of linear equations) that familiar concepts of dynamic system theory can be extended to this more general class, although sometimes with significant modification. Two new (and essentially dual) concepts, that of solvable and conditionable sets of equations, are found to be fundamental to the study of equations of this form. The notion of initial conditions, although not directly related to a state, is used as a general solution method for equations of this type. In addition a set of necessary and sufficient conditions for a set of dynamic equations to contain an embedded state-space representation is derived.
Hydrogen behavior in Mg+-implanted graphite

A graphite wafer has been implanted with Mg+ to produce a uniform Mg concentration. Subsequent H+ implantation covered both the Mg+-implanted and unimplanted regions. Ion-beam analysis shows a higher H retention in graphite embedded with Mg than in regions without Mg. A small amount of H diffuses out of the H+ implanted graphite during thermal annealing at temperatures up to 300°C. However, significant H release from the region implanted with both Mg+ and H+ ions occurs at 150°C; further release is also observed at 300°C. The results suggest that there are efficient H trapping centers and fast pathways for H diffusion in the Mg+ implanted graphite, which may prove highly desirable for reversible H storage.implanted graphite, which may prove highly desirable for reversible H storage.
A Fast Approximate Karhunen-Loève Transform (AKLT) for Data Compression

Abstract The Karhunen-Loeve transform is known to be the optimal transform for data compression. However, since it is signal dependent and lacks a fast algorithm, it is not used in practice. In this paper, a fast approximate Karhunen-Loeve transform (AKLT) is presented. This new transform is derived using perturbation theory of linear operators. Both the forward and inverse AKLT are analytically derived in closed forms. In addition, fast computational algorithms are developed for both the forward and inverse transforms. Performance comparisons reveal for a first-order Markov sequence that the AKLT performs better than the DCT in its energy compaction and signal decorrelation capabilities. Experiments on real images also demonstrate a definite superiority of the AKLT over the DCT when an adaptive scheme is used.
Update on noncardiac chest pain.

Patients with recurrent angina-like chest pain with normal coronary vessels are deemed to have the syndrome of noncardiac chest pain (NCCP). These patients, despite having significant cardiac disease
Pulsatile luteinizing hormone release during pregnancy in the rat.

The present studies were designed to characterize LH release during pregnancy in the rat. Unanesthetized animals with jugular cannulae were bled for 3 h between 1000–1300 h on days 6–8, 14–16 or 22 of gestation (50 lμ whole blood/5 min). Plasma estradiol and progesterone values both increased from days 6–8 to days 14–16. However, while plasma estradiol levels increased further between days 14–16 and day 22, plasma P levels had declined 86%. The percent coefficients of variation obtained for alterations in blood LH levels at each stage of pregnancy were all significantly greater than intraassay variation, indicating that LH release was pulsatile at each stage. Although there were no significant differences in mean blood LH levels, pulse amplitude, or frequency between days 6–8 and 14–16, the individual patterns of LH release clearly varied between these 2 groups, and most notably within the 14–16 day group. Fifty-three percent (9 of 17) of the LH records in rats on days 14–16 were nonpulsatile compared to ...
The generation of a colE1-Apr cloning vehicle which allows detection of inserted DNA

A 3.2 Mdal sequence of DNA, TnA, which contains the ampicillin (Ap) resistance determinant has been translocated from an R plasmid to the plasmid ColE1. A total of 12 isolates were studied. There are at least 8 sites in ColE1 at which TnA has inserted. Insertion at five of these has resulted in a Col-phenotype. One ColE1-Apr plasmid, RSF2124, was examined further and its replication properties are found to be similar to that of the parent plasmid. RSF2124 appears to be a useful plasmid vehicle for the molecular cloning of DNA from diverse prokaryotic sources: it codes for readily detectable Ap resistance and contains a single EcoRI site in a gene affecting colicin biosynthesis so that it is unable to produce colicin upon ligation to other DNA.
The risk experience: the social effects of health screening and the emergence of a proto‐illness

Those who undergo health screening often experience physical and emotional effects as a result of the screening process. However, the effects of health screening go beyond these physical and mental complications, often having profound social effects for those who are screened. This study explores the social implications of health screening for people who undergo it and are designated as being at risk for potential disease. Through a qualitative analysis of the experiences of individuals with elevated cholesterol levels and men with elevated prostate-specific antigen (PSA) levels, this research offers a description of the experience of being at risk, identifying three primary components: increased medical contact, a restructuring of everyday routines and altered social relationships. Whereas the at-risk health status engendered by current clinical approaches to screening and surveillance has been characterised as proto-disease, this study develops a companion definition of proto-illness to characterise the social experience of life with an identified health risk. Those who are at risk act in ways that are similar to those who are ill. The concept of proto-illness implies that the experience of risk is parallel to the experience of illness and contributes to the sociology of medical screening by establishing a much needed bridge between the two experiences.