cssi/SciSciGPT-SciSciNet huggingface dataset:
Temporal adaptive algorithm for TRAC-BF1/NEM/COBRA-TF coupled calculations in BWR safety analysis

Abstract A temporal adaptive algorithm was developed to perform the synchronization and optimization of the performance of TRAC-BF1/NEM/COBRA-TF three-dimensional neutron/thermal-hydraulics sub-channel analysis coupled code system. The multi-level coupling scheme for time synchronization of the TRAC-BF1/NEM and COBRA-TF under PVM is developed considering the different time-step selection algorithms of TRAC-BF1, NEM and COBRA-TF codes. The developed methodology allows one to synchronize the codes in time without doing significant code modifications to the time-step selection logic of the involved codes. The advantage of this approach is that COBRA-TF can capture the nature of a given transient, without losing any time-dependent data. Results for steady state and transient calculations that show how the implemented temporal adaptive algorithm works are presented. In addition selected results are presented to illustrate dynamic behavior and the type of thermal-hydraulic boundary conditions provided by the system code.
Basic and clinical pharmacology of the acetylcholine receptor: implications for the use of neuromuscular relaxants.

Multiple factors alter the interaction of muscle relaxants with the neuromuscular (NM) junction. This review focused on the aberrant responses caused, principally, by alterations in acetylcholine receptor (AChR)s. It should be emphasized that prejunctional and post AChR factors also may alter sensitivity to muscle relaxants and also cause functional changes, including muscle weakness. The pharmacokinetic and pharmacogenetic factors which cause aberrant responses have not been discussed. Many pathological states increase or decrease AChRs and this has been enumerated in Table 1. Increased AChRs is associated with resistance to the NM effects of nondepolarizing (ND)MR. With proliferation of AChR, the exaggerated release of potassium with depolarization from succinylcholine (SCh) can be attributed to increased AChR number; qualitative changes in AChR number may also play a role. Preliminary studies using potassium channel inhibitors indicate that potassium channels do not play a major role in the hyperkalimic response to SCh. During acute organophosphorus poisoning, SCh should be avoided because its metabolic breakdown would be impared;1 the requirement for NDMR may be increased because of increased competition with high leels of ACh at the neuromuscular junction. With the chronic presence of ACh at the neuromuscular junction there would be down regulation and the responses would be similar to that seen in myasthenia gravis. All of these responses to SCh and NDMR which are associated with concomitant changes in AChR are analogus to drug-receptor interactions observed in other biological systems.
Long-Term Effects of Poultry Litter, Alum-Treated Litter, and Ammonium Nitrate on Phosphorus Availability in Soils

Alum (Al2(SO4)314H2O) additions to poultry litter result in lower ammonia (NH3) volatilization and phosphorus (P) runoff; however, the long-term effects of alum on soil P behavior have been unknown. The objectives of this study were to evaluate the long-term effects of poultry litter, alum-treated litter, and ammonium nitrate (NH4NO3 )o n P availability in soils and P runoff. Two studies were initiated in 1995: a smallplot(1.533.0m)studyandapairedwatershed(0.405ha)study.In the small plot study 13 treatments (control, four rates of normal litter, fourratesofalum-treatedlitter,andfourratesofNH4NO3)wereapplied to tall fescue (Festuca arundinacea Schreb.) plots. Results show that after 7 yr water-extractable P (WEP) in surface soil samples was greater withnormallitter, butMehlichIIIPwasgreaterinsurfacesoils fertilized withalum-treatedlitter.Whensoilsamplesweretakenatdepthintervals to 50 cm in Year 7, Mehlich III P was only greater in the surface 5 cm for soils fertilizedwithalum-treatedlitter. AtlowerdepthsMehlichIII P was greater with normal litter, and WEP was up to 288% greater when normal litter was used, indicating that alum significantly reduced P leaching. Uptake of P by fescue was not affected by alum. Results from
MEASUREMENT OF TISSUE ABSORPTION COEFFICIENTS BY USE OF INTERFEROMETRIC PHOTOTHERMAL SPECTROSCOPY

We describe a spectroscopic technique called interferometric photothermal spectroscopy (IPTS) that can measure the absorption coefficient of pulsed laser radiation in nonscattering tissue samples. The technique is suitable for measuring effective absorption coefficients from 10(3) to 10(5) cm(-1). IPTS is particularly attractive because it requires minimal disturbance of the sample. These features indicate potential use for in vivo measurements of tissue absorption coefficients. To validate the technique, the absorption coefficient of pulsed Q-switched Er:YSGG (2.79-microm) radiation in pure water was measured to be 5200 (+/-500) cm(-1) when IPTS was used, in agreement with other published values. IPTS was also used to measure the absorption coefficient of pulsed ArF excimer laser radiation (193 nm) in bovine corneal stroma (in vitro), giving a value of 1.9 (+/-0.4) x 10(4) cm(-1).
Molecular Structures of the Buried Interfaces between Silicone Elastomer and Silane Adhesion Promoters Probed by Sum Frequency Generation Vibrational Spectroscopy and Molecular Dynamics Simulations

Silane adhesion promoters are commonly used to enhance the adhesion of elastomeric materials to polymers in many industrial applications. However, it is difficult to study the molecular-level mechanisms underlying adhesion promotion because adhesion occurs at the boundary between two layers, a buried interface that is difficult to probe with most techniques. Here, a surface/interface-sensitive optical technique, sum frequency generation vibrational spectroscopy, was used to probe the buried interfaces between the silicone elastomer and (3-glycidoxypropyl)trimethoxysilane (γ-GPS) as well as a known silane adhesion-promoting mixture of γ-GPS and methylvinylsiloxane (MVS). The γ-GPS methoxy groups were found to order at the silicone interface both in the neat silane and in the mixture with MVS. The interfacial structures between the silicone elastomer and two other silanes not used as adhesion promoters, n-octadecyltrimethoxysilane (OTMS) and (tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane (TDFTMS), ...
Anomalous density of states in multiband superconductors near the Lifshitz transition

The authors describe anomalous superconducting properties in a shallow band in which Cooper pairing is induced by deep bands. They demonstrate that the thermodynamic topological phase transition is eliminated by superconductivity, but nevertheless the density of states shows likely detectable qualitative changes with variation of the chemical potential. The authors argue that the proposed physical scenario provides the most natural interpretation for the gap structure recently observed in some iron pnictides and chalcogenides with shallow bands.
Economic aspects of pharmacokinetic services.

Clinical pharmacokinclics has been used \0 optimise drug therapy si nce the early 1970s. The ap. plica lion of these mathematical principles has been used to assess drug therapy and optimise serum concentrations. The reasons that these principles have gained acceptance include: (a) the develop-. ment of rapid and easy drug monitoring assays; (b) the principle thai serum concentrations of drugs correlate to a greater degree with effi cacy and toxicity than drug dosages; and (c) an understanding of the science of drug absorption, distribution, metabolism and excretion (Levy 1986). Si nce thc 1970s, these principles have given rise to the development of the C linical Pharmacokinetic Service (CPS) within many hospitals. The goal ofa CPS is to assist in the provision of quality pharmaceutical care for patients receiving therapy with drugs which have a narrow therapeutic range. Pharmacy departments o f hospitals that have developed a CPS have had to justify its cost, because it is outside the practice of dispensing or distributing drugs to hospitalised patients. Hospital administrators have therefore required an objecti ve measure of benefit for patients when a CPS is involved with drug therapy. This is particularly important at the present time w hen fiscal profitability of many hospitals has tended to diminish. Cost justification ofa CPS may also help maintain CPS staffing levels when budgetary constraints are being implemented. One method of performing a cost-benefit analysis is to compare differences in outcomes between 2 groups of patients during a specific time period when Ihe o nl y difference is t hat I group is assigned to a C PS while the other group acts as the control. The speci fi c time period could be the s tart of Ihe fi scal year or the start of a calendar year. The benefit-to-cost (B/C) ratio is defined as Ihe amount of money saved (8) divided by the amount of money spent on the CPS (C):
Partial Protection in Optical WDM Networks: Enhanced Support for Dynamic Traffic

In this paper, we consider a circuit-switched optical wavelength division multiplexed (WDM) network that offers protection services to the connections established in the network. A dynamic traffic model, where connection requests arrive based on some stochastic arrival process, is considered. In earlier work, the notion of partial protection was introduced for a WDM network with sub-wavelength capacity allocation capabilities, as in TDM-WDM networks, for a dynamic traffic model. Here, instead of setting up a backup path with the same capacity as the primary, the backup path is established with capacity that is less than the primary path's capacity, where the amount of backup path capacity is specified by the user. Intuitively, this will reduce backup path requirements, thereby increasing the number of connections accepted. In (J. Fang et al., 2005), the mechanism presented attempted to provide the maximum available protection bandwidth while ensuring that the minimum backup requirements are met. However, this can still result in wasted protection bandwidth if failures do not occur. In this paper, we present a mechanism to further improve the performance of partial protection schemes for dynamic traffic. When failure occurs, the connection is carried on the backup with reduced capacity. However, the system tries to identify additional spare capacity on the same backup path, on either the same wavelength or a different wavelength. The objective is to increase the amount of backup capacity at the time of failure, so that the connection's end user does not see a noticeable drop in bandwidth allocated. We present a heuristic connection admission control algorithm that prevents backup contention that occurs when backup paths of connections affected by a failure contend (share) for resources. A detailed performance evaluation of the mechanisms for different network topologies and other system parameters is presented. For one of the cases studied, the connection acceptance probability is increased from 95% to 99%, while providing nearly 100% backup capacity, when failure occurred. The mechanism proposed to counter backup contention is seen to provide an average of 120% reduction in the contention among backup paths of connections traversing a link, especially when the number of wavelengths in each link is small.
Oxygen consumption in infants with bronchopulmonarydysplasia

2. Ostrow JD: Photocatabolism of labeled bilirubin in the congenitally jaundiced (Gunn) rat, J Clin Invest 50:707, 1971. 3. Lightner DA, Wooldridge TA, and McDonagh AF: Photobilirubin: An early bilirubin photoproduct detected by absorbance difference spectroscopy, Proc Natl Acad Sci USA 76:29, 1979. 4. McDonagh AF. Palma LA, and Ligbmer DA: Blue light and bilirubin excretion, Sciencc 208:145, 1980. 5. Onishi S, Isobe K, ltoh S, Kawade N, and Sugiyama S: Demonstration of a geometric isomer of bilirubin-IXa in the serum of a hyperbilirubinemic newborn infant and the mechanism of jaundice phototherapy, Biochem J 190:533, 1980. 6. Jendrassik L, and Grof P: Vereinfachte photonetrische method zur besdtimmung des blutibilirubin, Biochem Z 297:8I, 1938. 7. Nosslin B: The direct diazo reaction of bile pigments in serum, Scand J Clin Lab Invest 12 (Suppl 49):1, 1960. 8. Winer B J, editor: Statistical principles in experimental design, ed 2, New York, 1971, McGraw Hill Book Company. 9. Kopelman AE, Brown RS, and Odell GB: The "bronze" baby syndrome: A complication of phototherapy, J PFmATR 81:466, 1972.
Application of Polarization of Fluorescence Technique to Protein Studies. I. The Rotatory Properties of β-lactoglobulin

Summary A study was conducted using the polarization of fluorescence method to characterize β -lactoglobulin. The method involved forming a fluorescent dye conjugate of the protein molecule with a dye molecule (1-dimethylaminonaphthalene-5-sulfonyl chloride) which imparted fluorescent properties to the conjugate. Only minor alteration in the physical properties of the protein was produced by the conjugation process. Curves of reciprocal polarization vs. T/η for β -lactoglobulin yielded an average slope of 1.02×10 −4 at 0.02 ionic strength and 0.72×10 −4 at 0.10 ionic strength. The apparent molecular volume of a spherical protein molecule, having the same relaxation time as the slightly elongated β -lactoglobulin molecule, was 98,310 cm3 at 0.10 ionic strength and 64,580cm 3 at ionic strength 0.02. The mean harmonic relaxation time for β -lactoglobulin was 6.85×10 −8 sec at 0.02 ionic strength and 10.91×10 −8 sec at 0.10 ionic strength. Addition of sucrose to protein solutions to increase the viscosity and, thereby, reduce the rate of rotatory diffusion of the fluorescent β -lactoglobulin molecule, resulted in substantial reduction in the apparent molecular volume.
Interplay of maturation-promoting factor and mitogen-activated protein kinase inactivation during metaphase-to-interphase transition of activated bovine oocytes

The objective of the present study was to examine the activity changes in histone H1 kinase (also known as maturation-promoting factor [MPF]) and mitogen-activated protein kinase (MAPK) and their constituent proteins in in vitro-matured bovine oocytes after in vitro fertilization (IVF) or after parthenogenetic activation induced by calcium ionophore A23187 alone or by the ionophore followed by either 6-dimethylaminopurine (6-DMAP) or cycloheximide (CHX). Inactivation of both H1 kinase and MAPK occurred after both A23187+6-DMAP treatment and IVF; inactivation of H1 kinase preceded inactivation of MAPK. However, MAPK was inactivated much earlier in 6-DMAP-treated oocytes. Further analysis of constituent cell cycle proteins of these kinases by Western blot showed that A23187 alone could not induce changes in cdc2, cdc25, or ERK2 but induced reduction of cyclin B1. IVF and A23187+CHX induced similar changes: cyclin B1 was destroyed shortly after activation followed by accumulation of cyclin B1, phosphorylation of cdc2, and dephosphorylation of ERK2 at pronuclear formation 15 h after activation. No change in cdc25 was observed at this time. In contrast, A23187+6-DMAP treatment resulted in earlier phosphorylation of cdc2 and dephosphorylation of ERK2 at 4 h after treatment when the pronucleus formed. Moreover, accumulation of both cdc25 and cyclin B1 was detected at 15 h. Microinjection of ERK2 antibody into A23187-treated oocytes resulted in pronuclear formation. In conclusion, activation of bovine oocytes with 6-DMAP led to earlier inactivation of MAPK, while CHX induced inactivation of MAPK parallel to that following sperm-induced oocyte activation. Destruction of cyclin B is responsible for inactivation of MPF, while phosphorylation of cdc2 is likely responsible for maintaining its low activity. Inactivation of MAPK is closely associated with pronuclear development regardless of the activation protocol used.
Brevetoxin-2 induces an inflammatory response in an alveolar macrophage cell line.

Abstract Brevetoxins, the algal toxins produced by Karenia brevis during red tide blooms, adversely impact health following ingestion or inhalation. Inhalation of brevetoxins results in a variety of acute symptoms including coughing, wheezing, and shortness of breath. Analysis of manatee lungs following death by purported brevetoxicosis has identified brevetoxin accumulation within macrophages, with pathological manifestions of lung congestion, inflammation, and edema. The goals of this work were to specifically examine effects of brevetoxin-2 on alveolar macrophages, a key cell in responding to toxins in the lung, as well as to determine if brevetoxin-2 results in an inflammatory response and/or direct cytotoxicity. Exposure of an alveolar macrophage cell line (MH-S) to an environmentally and physiologically relevant dose of brevetoxin-2 (0.5 μg/ml) did not significantly alter cellular growth over a 24 h time period. However, exposure of MH-S cells to brevetoxin-2 for 6 h increased phagocytosis of latex beads, increased secretion of interleukin (IL)-2, IL-4, and tumor necrosis factor-α, and decreased secretion of IL-5. Very few changes were seen in gene expression following 3 or 6 h exposure to brevetoxin-2. These results show that brevetoxin-2 induced an immune response indicative of inflammation in an alveolar macrophage cell line, indicating that inhalation of brevetoxin-2 may lead to lung inflammation through an alveolar macrophage-initiated pathway.
The Ni-containing carbon monoxide dehydrogenase family: light at the end of the tunnel?

OAK-B135 Metalloenzymes seem to ''come of age'' when their structures are known at atomic resolution, spectroscopic and catalytic properties are basically understood, and genetic expression systems are available. Such foundations allow detailed mechanistic and spectroscopic properties to be probed and correlated to structure. The objective of this article is to summarize what is known about the title group of enzymes, and show that, to a large degree, they have come of age.
Effect of Frequency Excitation on Force Coefficients of Spiral Groove Gas Seals

An analysis for compressible fluid spiral groove thrust bearings (SGTBs) and face seals (SGFSs) is presented. Zeroth- and first-order equations rendering the static and dynamic performance of SGFSs, respectively, are solved using the finite element method with a successive approximation scheme. Comparison of the present isothermal compressible fluid model for static and dynamic SGTB and SGFS performance validates previous narrow groove theory, finite difference, and finite element analyses. A discussion follows to indicate the importance of using a small number of grooves to prevent instabilities from negative damping in SGTBs and SGFSs when pressurization is lost. Force coefficients are shown to reach asymptotic limits as the axial excitation frequency increases.
The Performance Effects of Squeeze Film Stiffness on Non-Resonate Interferometric Inertial Sensors

This paper studies the nonlinear effects of squeeze film stiffening on the performance of a high resolution MEMS nonresonant inertial sensor. It is shown that these effects introduce a surprising dynamic response that extends the operational frequency range of the devices by retarding the resonate response. In addition, this performance advantage will occur without the traditional gain trade-off associated with linear systems of this type. A method is introduced to experimentally characterize the squeeze film stiffness of a passive inertial sensor through the resonant characterization of a Fabry-Perot interferometric accelerometer under reduced pressure. Such passive devices are uniquely suited for the study of squeeze films and, due to the dependence of both the sensitivity and bandwidth on the device structural stiffness, variation of the stiffness with frequency must be considered to accurately predict sensor performance. The characterization confirms established analytical squeeze film stiffness theory in the continuous gas regime for conditions of Knudsen numbers less then one. As the Knudsen number equal to one is approached, it is shown that ideal kinetic gas theory and continuous squeeze film theory converge yielding a simplified stiffness estimate under the resonant response under reduced pressure. These analytical results are used to predict the performance gains due to the nonlinear, frequency dependent total stiffness of the sensor during non-resonant operation.Copyright © 2007 by ASME
Nucleon-nucleon on-shell and off-shell contributions to the triton binding energy in an energy-dependent potential model formulation

Abstract An energy-dependent nucleon-nucleon (NN) potential model is presented which allows an unambiguous separation of NN on-shell and off-shell contributions to trinucleon observables. A potential of the form V(E; p, p′) = λ (E) V (p, p′) is constructed at negative energies by comparison with various hermitian potentials. The latter comparison suggests a symmetric choice of λ ( E ) with respect to E = 0. It is shown that the force model constructed according to the present study is more reasonable and less ambiguous than the hermitian potential model, for which the negative-energy dependence of the corresponding t -matrix is generated in an arbitrary way by the accidental choice of the off-shell behavior of the potential. The pertinent shortcomings of the conventional potential model are elucidated by their inconsistent predictions for two- and three-nucleon systems. In the case of the proposed energy-dependent potential model the on-shell information is decoupled from the off-shell behavior at positive and negative energies. This allows one to eliminate the two-body off-shell contributions within the three-body equations in a continuous process by taking the range of forces to zero while keeping at each step the two-body on-shell information unaltered.
The Stories We Tell Ourselves

Storytelling involves weaving abstractions about fundamental truths regarding the world and the human experience to entertain and educate. When it comes to movies and television, producers and directors often make computer technology look like magic. It doesn't have to be that way. The Web extra at http://youtu.be/DqpL0q5LRlk is an audio podcast of author Grady Booch reading his On Computing column, in which he discusses how movies and television programs often make computer technology look like magic when it's really not.
A comparative analysis of obsolescence patterns of the U.S. Geoscience literature

The United States (U.S.) geoscience literature is employed as a vehicle to study the phenomenon of obsolescence. Problems investigated include the classical and ephemeral aspects of subject literatures, diversity among narrowly defined literatures within broadly defined subject literatures, and the effect of literature growth on obsolescence. Comparisons are made: 1. among time-frequency bibliographs based on citation counts from each of twelve major journals published in 1969; 2. between bibliographs of three major journals for the years 1969 and 1949; and 3. between uncorrected and corrected obsolescence curves. Each journal yields citation patterns comprised of both an ephemeral and a classical literature component. Within this framework apparent obsolescence varies across a broad spectrum, from physics/chemistry-oriented geoscience subdisciplines with relatively short “half-lives,” to those biology-oriented with relatively long “half-lives.” Obsolescence rates of traditional geoscience fields seem to vary little between 1949 and 1969 in contrast to those of fast-changing fields such as solid earth geophysics. The relationship between obsolescence curves uncorrected and corrected for growth suggests the operation of factors that control research fronts. The effect of literature size on obsolescence, though minor for the recent literature, is more pronounced for the classical literature.
High-frequency production of respiratory mutants in yeast under nutritional deficiencies.

Abstract Production of respiration-deficient mutants in unusually high frequencies up to 100% was observed when an originally stable, normal culture of yeast was grown in Schopfer 's medium which is very simple and lacking in vitamines. The mutant production was significantly reversed, often to the minimal spontaneous level by addition of biotin, pantothenate, yeast extract and several amino acids, and also by substitution of the asparagine in Schoffer 's medium with several nitrogenous nutrients. Such a production of respiratory mutants under nitritional deficiencies was found to be dependent largely upon the yeast species and strain. Two strains of Saccharomyces cerevisiae var. ellipsoideus readily produced 100% mutants. A few others produced close to 100% mutants after successive transfers, repeated 3 to 4 times, in Schopfer 's medium. Yet other species remained normal even after repeated passages. Nutritional background conditions for hereditary maintenance of respiratory competence are discussed.
Efficacy and effectiveness issues in the NIDA cooperative agreement : Interventions for out-of-treatment drug users

Abstract This paper examines the Cooperative Agreement (CA) HIV intervention studies for active drug users, sponsored by the National Institute on Drug Abuse, in terms of the constructs of prevention efficacy and effectiveness. A rationale is presented for conservatively interpreting outcome findings of these studies as indicative of intervention efficacy, as opposed to effectiveness. It is argued that the CA studies fall more within the domain of efficacy owing to the high degree of control and optimization that occurred with respect to intervention recruitment, participation, process monitoring, and staff training. Because the interventions were implemented and evaluated in community-based, noninstitutional settings with many real-world constraints, it is suggested that minimal shrinkage of their effects would occur if they were implemented in uncontrolled community settings. The relationship of intervention structure, content, process, dose, and participant characteristics to intervention efficacy is r...
A Systematic Approach to Evaluating the Effects of Collaborative Negotiation Training on Individuals and Groups

Negotiation training evaluation tends to be short-term, aspectual and piecemeal; evaluations often focus on only one or two salient outcomes of training. This essay presents a model for negotiation training evaluation research that offers a broad conceptualization of the hypothesized individual and group-level effects of training in collaborative negotiation. The model assesses change at the individual level in conflict-related cognitions, attitudes, affect and behaviors; and at the group level in conflict outcomes and work climate. The Negotiation Evaluation Survey (NES), a time-delayed, multi-source feedback approach to assessment and development, is presented as a means of addressing some of the conceptual and methodological problems inherent in more common methods of training evaluation. An illustrative assessment of one model of collaborative negotiation training for adults, the Coleman/Raider Model, is presented. The results, implications, and future research challenges are discussed.
Effects of progesterone treatment on smoked cocaine response in women.

Abstract The effects of female sex hormones on responses to cocaine have not been systematically investigated in women. In this study, the safety and efficacy of acute progesterone treatment on smoked cocaine response was examined in female cocaine users. Five women had two experimental sessions during the early follicular phase, within 3–9 days after the beginning of their menses. In each experimental session, subjects received a single 200-mg dose of progesterone or placebo orally. Starting 2 h after the medication treatment, subjects received three deliveries of 0.4-mg/kg smoked cocaine 30 min apart. Progesterone treatment, compared to placebo, did not affect the blood pressure and heart rate changes in response to cocaine deliveries. For subjective responses to cocaine, the average of five-item Cocaine Effects Questionnaire (CEQ) was attenuated under progesterone treatment compared to placebo. For individual items of CEQ, progesterone treatment was associated with diminished rating of “feel the effect of last dose” in response to cocaine. These preliminary results suggest that acute progesterone treatment, given during the early follicular phase, may attenuate some of the subjective effects of cocaine. Further studies are warranted to examine the effects of progesterone treatment on cocaine dependence.
Co-translational Localization of an LTR-Retrotransposon RNA to the Endoplasmic Reticulum Nucleates Virus-Like Particle Assembly Sites

The transcript of retrovirus-like transposons functions as an mRNA for synthesis of capsid and replication proteins and as the genomic RNA of virus-like particles (VLPs), wherein the genome is replicated. Retrotransposon RNA and proteins coalesce in a cytoplasmic focus, or retrosome, to initiate VLP assembly, but it is not known how the retrosome is nucleated. We determined how the RNA and Gag protein of the Saccharomyces cerevisiae Ty1 retrotransposon are directed to the retrosome. We found that Ty1 RNA is translated in association with signal recognition particle (SRP), a universally conserved chaperone that binds specific ribosome-nascent chain (RNC) complexes and targets the nascent peptide to the endoplasmic reticulum (ER). Gag is translocated to the ER lumen; yet, it is also found in the cytoplasm, associated with SRP-RNC complexes. In the absence of ER translocation, Gag is synthesized but rapidly degraded, and Ty1 RNA does not coalesce in retrosomes. These findings suggest that Gag adopts a stable conformation in the ER lumen, is retrotranslocated to the cytoplasm, binds to Ty1 RNA on SRP-RNC complexes and multimerizes to nucleate retrosomes. Consistent with this model, we show that slowing the rate of co-translational ER translocation by limiting SRP increases the prevalence of retrosomes, while suppressing the translocation defect of srp hypomorphs by slowing translational elongation rapidly decreases retrosome formation. Thus, retrosomes are dynamic foci of Ty1 RNA-RNC complexes whose formation is modulated by the rate of co-translational ER translocation. Together, these findings suggest that translating Ty1 mRNA and the genomic RNA of VLPs originate in a single pool and moreover, that co-translational localization of Ty1 RNA nucleates the presumptive VLP assembly site. The separation of nascent Gag from its RNA template by transit through the ER allows Gag to bind translating Ty1 RNA without displaying a cis-preference for its encoding RNA.
Inhibitors of the 25-hydroxylation of vitamin D3 in the rat

Abstract Two new sidechain-modified analogs of vitamin D 3 , 25-azavitamin D 3 and 25-fluorovitamin D 3 , were prepared; both compounds were found to inhibit the in vivo 25-hydroxylation of vitamin D 3 in the rat. 25-Azavitamin D 3 was chemically synthesized from a degradation product of stigmasterol by a six-step process. The desired carbon skeleton was efficiently assembled by alkylation of a suitably protected C-20 bromomethylpregnane with the enolate of N,N -dimethylacetamide (70%). The completion of the synthesis utilized the known photochemistry of steroidal 5,7-dienes to prepare the vitamin D triene system. In contrast, 25-fluorovitamin D 3 was prepared by direct vitamin modification. 25-Hydroxyvitamin D 3 3-acetate was fluorinated with diethylaminosulfur trifluoride to give 25-fluorovitamin D 3 3-acetate (59%); saponification provided the desired analog. When vitamin D-deficient rats on a low calcium diet were dosed with [3- 3 H]vitamin D 3 (0.05 μg), 10% of the dose was found in serum as 25-hydroxyvitamin D 3 4 hr after administration. If 25-azavitamin D 3 (50 or 200 μg) was given 2 hr before the radiolabeled vitamin D 3 , however, serum 25-hydroxyvitamin D 3 concentration was markedly reduced. 25-Fluorovitamin D 3 caused similar reduction when administered at much lower doses.
Reservation Prices on Credit Use: A Measure of Response to Uncertainty

Liquidity in the form of reserved credit is valuable to a business manager because it is available to counter uncertain expectations. This paper investigates the definition and method of estimating values or reservation prices associated with firm liquidity provided by unused credit. A multiperiod linear programming model is taken to reflect the behavior of decision makers in empirically observed situations. Credit reservation prices of decision makers were inferred by comparing growth information for real borrowers with growth information generated by the comparable model at alternative reservation prices. This method succeeded in associating a high credit reservation price with the conservative borrower and low credit reservation prices with a more liberal borrower.
[3H]Glutamate uptake at insect neuromuscular junctions: effect of chlorpromazine

Abstract Previous studies have shown that in an isolated cockroach nerve-muscle preparation, nerve stimulation causes an increase in uptake of [ 3 H]glutamate during subsequent incubation in a medium containing this amino acid 21,50 . The enhanced glutamate uptake is largest in the tracheole cells, sheath cells, especially in the junctional regions, and in the postsynaptic regions of the muscle. This differential effect suggests that nerve stimulation affects more than one glutamate pool, and since glutamate is the presumed transmitter in this system, the uptake at the junction may be involved in transmitter inactivation by re-uptake. In the present study chlorpromazine, which is known to interfere with transmitter re-uptake in a variety of systems, was added to the [ 3 H]glutamate incubation medium after prolonged nerve stimulation. It was found that chlorpromazine decreased the stimulation-enhanced uptao a varying to extent in the different muscle and sheath compartments. It did not affect uptake by tracheole cells and had its major effect at the neuromuscular junctions. Chlorpromazine decreased the junctional sheath uptake to the level of the non-junctional sheath, thus eliminating the differential sheath uptake. In the muscle, chlorpromazine did not completely eliminate the difference between junctional and non-junctional uptake, but decreased it greatly. The data suggest that the various pools depleted by nerve stimulation are replenished by different uptake mechanisms. The finding that chlorpromazine has its major effect on the uptake into junctional compartments is consistent with the hypothesis that the junctional sheath and postsynaptic muscle regions are sites of transmitter inactivation by re-uptake.
Labeling of fatty acids with 4-bromomethyl-7-methoxycoumarin via crown ether catalyst for fluorimetric detection in high-performance liquid chromatography

Abstract A method for the fluorescence labeling of fatty acids with 4-bromomethyl-7-methoxycoumarin using 18-crown-6 as a catalyst is described. The procedure is rapid, simple and requires little or no experience in derivatization techniques. The amounts of the derivatives are linearly related to the amount of the starting fatty acids and the procedure can therefore be used in the quantitative analysis of these solutes. Using reversed-phase chromatography, detection levels as low as 9 pmole could be realized. The separations of several derivatives using a reversed-phase system are discussed.
Diagnosis of Adult Hereditary Pulmonary Disease and the Role of Genetic Testing

Genetic testing is becoming a common component of medical practice and is used to determine definitive diagnoses for several adult pulmonary diseases. It is important for pulmonologists to know when to use genetic tests for diagnosis and medical management. This article describes diagnosis of rare hereditary pulmonary disease in adults and the role of genetic testing. A summary on coding and reimbursement is included.
The effect of chronic cocaine on self-stimulation train-duration thresholds ☆

Abstract The effect of chronic cocaine treatment on brain stimulation reward was assessed by examining self-stimulation train-duration thresholds. Following a predrug, saline injection period, cocaine hydrochloride (10 or 15 mg/kg) was injected (IP) across 18 consecutive days of testing. Cocaine lowered thresholds across the entire period of drug administration, with the magnitude of cocaine's effect remaining stable during this time. The subjects returned to predrug, saline levels during a postdrug test conducted immediately following chronic cocaine treatment. In a final attempt to modify cocaine's effects, the subjects received 25 mg/kg cocaine HCl three times/day for three consecutive days. Subsequent testing at the original dosage levels revealed no change in the magnitude of cocaine's effect. It was concluded that cocaine's effect on brain stimulation reward does not slow tolerance or sensitization with chronic use. Similar effects have been reported for morphine and amphetamine's effect on brain stimulation reward.
Color appearance with sparse chromatic context

We compared changes in the appearance of a test region caused by introducing an inhomogeneous chromatic background to changes caused by a space-averaged equivalent uniform background. Subjects adjusted a test field presented on a CRT so that it appeared neither reddish nor greenish. Sparse "white" or "green" dots, randomly scattered throughout a "red" background field, caused a large decrease (up to 15 nm) in the dominant wavelength of the red/green equilibrium setting, compared to measurements with a uniform "red" background. A uniform background with the same space-averaged chromaticity and luminance as the complex background had an effect similar to the uniform "red" background. These results contradict theories of color constancy that rely on the "gray world" assumption, and indicate the significance for color perception of individual chromaticities within discrete, noncontiguous regions.
Intraarticular bupivacaine-clonidine-morphine versus femoral-sciatic nerve block in pediatric patients undergoing anterior cruciate ligament reconstruction

We hypothesized that combined femoral-sciatic nerve block (FSNB) offers better analgesia with fewer side effects than intraarticular infiltration (IA) in children undergoing anterior cruciate ligament (ACL) reconstruction. Thirty-six children undergoing ACL reconstruction were randomized to FSNB or IA. FSNB patients had FSNB with bupivacaine (0.125%)-clonidine (2 microg/kg), whereas IA patients received bupivacaine (0.25%)-clonidine (1 microg/kg)-morphine (5 mg). Postoperatively, analgesia was provided with patient-controlled analgesia and rescue morphine. Patient demographics were similar. FSNB patients required less intraoperative fentanyl (50 +/- 40 microg versus 80 +/- 50 microg; P = 0.04). Visual analog scale score for FSNB was smaller than IA in the recovery room (1.8 +/- 3 versus 5.4 +/- 3; P = 0.0002) and during the first 24 h (1.6 +/- 1 versus 2.9 +/- 2; P = 0.01)). FSNB morphine use in the first 18 h was less (7 +/- 13 mg versus 21 +/- 21 mg; P = 0.03). Fewer FSNB patients vomited (11% versus 50%; P = 0.03). IA patients required morphine patient-controlled analgesia sooner. After ACL reconstruction in children, FSNB with bupivacaine-clonidine provides better analgesia with fewer side effects than IA with bupivacaine-clonidine-morphine.
The Identification and Quantitation of Malondialdehyde, Formaldehyde, Acetaldehyde, and Acetone in Serum of Rats

A high-pressure liquid chromatographic (HPLC) method has been developed for the simultaneous determination of serum levels of malondialdehyde, formaldehyde, acetaldehyde, and acetone. Serum samples were derivatized with 2,4-dinitrophenylhydrazine (DNPH) to form the corresponding hydrazones of the four lipid metabolites. The hydrazones were extracted with pentane and chromato-graphed on a μ Bondapak C18 column. Acetonitrile-water (49:51 v/v) was used as the mobile phase. Treatment of rats with 2, 4, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) (50 μg/kg) resulted in marked time-dependent increases in the serum levels of the four metabolites. This HPLC method for identifying and quantitating formaldehyde, malondialdehyde, acetaldehyde, and acetone is rapid and highly reproducible. The method has widespread applicability to the assessment of metabolic alterations produced by drugs, disease states, and toxicants.
The Thermostructural Response of Electic Contacts Having Brazy Defects

The thermostructural response of an electric contact having planar type defects at the brazed interface was investigated using a finite element model. The results of the analysis have indicated that the presence of a defect alters the temperature field. This perturbation of the temperature by the defect produces localized stresses that can affect the life of the contactor.
Information Sharing Needs for National Security

The speed of today's networks has significantly increased in the last decade as has the speed intruders and malicious code can affect these networks. Society has become increasingly connected and dependent on the Internet. At the same time, effectively addressing attacks on the Internet and the critical infrastructures is becoming increasingly complex. Sharing security-related information has been a hot topic since the events of September 11, 2001. Much has been said about the need to transform the attitudes of the intelligence and security communities to foster information sharing. The mechanisms to accomplish this, however, have not been fully developed especially in the cyber arena. To deal with cyber attacks conducted on high-speed networks requires an organized approach from local cyber first-responders to national-level federal agencies. This paper examines the need for high-speed mechanisms to share information between industry and various levels of the government to address national security issues.
The effects of operational characteristics of catalytic cracking reactors on the closed-loop performance of linear model predictive controllers

In closed-loop simulations of the Amoco catalytic cracker under MPC, it was observed that the step response model identified at a low throughput operating point provided a better closed-loop performance when used on the high throughput operating point than a model identified at the latter operating point (Kalra and Georgakis, Ind. Engng Chem. Res. 33, 3063, 1994). The present paper reports on further simulation experiments and analysis that was performed to determine if it is the nonlinear nature of the process or deficiencies in model identification that caused the unexpected closed-loop behavior. When output error models identified from PRBS signals were used in the MPC algorithm this behavior was not observed, ruling out that nonlinearities might have been the cause. A closed-loop stability analysis of the process under MPC, with truth models as those derived via PRBS tests, confirms what is seen in simulations. A comparison of the models obtained from the two types of tests indicates that the step tests contained inadequate power to excite frequencies of interest to closed-loop control. Furthermore, the step test data from the high throughput operating point was adversely affected by the presence of noise cause by the numerical calculations in this complex model. The conclusion was that the use of step tests to directly determine the step response coefficients, as is commonly done, may not in some cases be a safe approach.
Parental egg care behavior and fanning activity for the orange chromide, Etroplus maculatus

Physiological studies revealed that agitation (simulated fanning) of the brood results in increased oxygen consumption, increased developmental rate and general promotion of brood success. It was also found that the more intense the agitation (excursions per minute) the greater the metabolic rate is enhanced. Embryos exposed to continual agitation hatched approximately twenty hours in advance of non-agitated eggs. Temporal studies of fanning activity in Etroplus maculatus showed significant differences between pairs breeding in colonial situations as compared to those breeding in isolation. Parental behaviors were recorded throughout egg care until hatching. Two types of ventilatory behaviors were described: active fanning and passive fanning. Pairs breeding in isolation invested more time in long passive bouts and less time in short active bouts. Conversely, colonial parents fanned predominately with short active bouts and displayed no prolonged passive fanning. Surprisingly, no differences were apparent in either reproductive success or hatching time between isolated and colonial pairs in this study. Orange chromides readily nested in two extremely different situations. They also displayed significantly different fanning regimes, behavioral time budgets and transitions of behavior; yet they were equally successful. Parental orange chromides can modulate their ventilatory activities in response to the contingencies of their nesting situation which ultimately allows them maximization of reproductive success.
Obscurin regulates the organization of myosin into A bands.

Obscurin is a giant sarcomeric protein composed of adhesion modules and signaling domains. It surrounds myofibrils at the level of the Z disk and the M line. To study the role of obscurin during my...
Efficient side-chain and backbone assignment in large proteins: application to tGCN5.

In determining the structure of large proteins by NMR, it would be desirable to obtain complete backbone, side-chain, and NOE assignments efficiently, with a minimum number of experiments and samples. Although new strategies have made backbone assignment highly efficient, side-chain assignment has remained more difficult. Faced with the task of assigning side-chains in a protein with poor relaxation properties, the Tetrahymena histone acetyltransferase tGCN5, we have developed an assignment strategy that would provide complete side-chain assignments in cases where fast 13C transverse relaxation causes HCCH-TOCSY experiments to fail. Using the strategy presented here, the majority of aliphatic side-chain proton and carbon resonances can be efficiently obtained using optimized H(CC-CO)NH-TOCSY and (H)C(C-CO)NH-TOCSY experiments on a partially deuterated protein sample. Assignments can be completed readily using additional information from a 13 C-dispersed NOESY-HSQC spectrum. Combination of these experiments with H(CC)NH-TOCSY and (H)C(C)NH-TOCSY may provide complete backbone and side-chain assignments for large proteins using only one or two samples.
Antinuclear autoantibodies in prostate cancer: immunity to LEDGF/p75, a survival protein highly expressed in prostate tumors and cleaved during apoptosis.

BACKGROUND Cancer patients produce autoantibodies to self-proteins called tumor-associated antigens (TAA). These autoantibodies represent potentially valuable tools for identifying novel biomarkers and therapeutic targets. This study was designed to identify TAA in prostate cancer (PCa). METHODS Serum autoantibodies to the survival protein lens epithelium-derived growth factor p75 (LEDGF/p75) were detected by immunofluorescence microscopy, ELISA, and immunoblotting. Expression of LEDGF/p75 in prostate cells and tumors was evaluated by immunoblotting or immunohistochemistry. Apoptotic cleavage of LEDGF/p75 was detected by immunoblotting. RESULTS Anti-LEDGF/p75 autoantibodies were detected by ELISA in 18.4% of PCa patients and 5.5% of matched controls (P < 0.001) but not in patients with benign prostatic hyperplasia (BPH). LEDGF/p75 expression was detected in 93% of prostate tumors but not in normal prostate. Strong expression of the protein was observed in 61% of prostate tumors. Moderate to high expression was also detected in BPH tissue. Cleavage of LEDGF/p75 was detected in apoptotic prostate cells. CONCLUSIONS The high expression of LEDGF/p75 in prostate tumors and BPH could be induced by inflammation and oxidative stress. LEDGF/p75 cleavage fragments generated during prostate tumor cell death might trigger autoantibodies under inflammatory conditions in certain patients. © 2004 Wiley-Liss, Inc.