cssi/SciSciGPT-SciSciNet huggingface dataset:
Biosynthesis of a mycobacterial lipopolysaccharide. Properties of the polysaccharide: acyl coenzyme A acyltransferase reaction.

Abstract A particulate enzyme preparation was obtained from Mycobacterium phlei cells which had the activity of a polysaccharide:acyl coenzyme A acyltransferse. We conclude that the enzyme system is involved in the biosynthesis of the methylglucose-containing lipopolysaccharide (MGLP), since it catalyzed the transfer of acetyl, propionyl, isobutyryl, octanoyl, and succinyl groups, all of which are known to be present in the lipopolysaccharide. Moreover, the enzyme preparation used α-(1→4)-d-glucooligosaccharides as acceptors, a result consistent with the fact that a major part of the polysaccharide component of the lipopolysaccharide has the same amylose-like structure. Both MGLP and its deacylated product, MGP, acted as acceptors of acyl groups, but MGP which had been partially acetylated by acetic anhydride was still more active. The random acetylation probably increased slightly the hydrophobic character of MGP and promoted its binding to the enzyme. In agreement with this idea was the fact that artificial d-glucooligosaccharide acceptors were completely inactive unless partially acetylated. Previous studies have established that five of the eight positions of acylation in MGLP-III are located on the four sugar units at the nonreducing end of the polysaccharide. From analysis of the product obtained in the enzymic reaction between [14C]acetyl-CoA and MGP, we now have evidence that at least two of the sites for acetylation occur in this tetrasaccharide unit. Removal of the four sugar units from MGP by the combined action of α-amylase and glucoamylase I destroyed the capacity of the polysaccharide to accept acetyl groups from acetyl-CoA. However, this partially degraded MGP retained acceptor activity for succinyl groups, which suggests that the sites for succinylation are located elsewhere in the polysaccharide, a result which is in agreement with direct chemical analysis of the lipopolysaccharide (Smith, W. L., and Ballou, C. E. (1973) J. Biol. Chem. 248, 7118–7125).
Hypertext : the convergence of contemporary critical theory and technology

George Landow's "Hypertext" brought together the worlds of literary theory and computer technology to explore the implications of giving readers instant, easy access to a virtual library of sources as well as unprecedented control of what and how they read. In hypermedia, Landow saw a strikingly literal embodiment of many major points of contemporary literary theory, particularly Derrida's idea of "de-centring" and Barthe's conception of the "readerly" versus "writerly" text. In this second edition, Landow shifts the focus from Intermedia to Microcosm, Storyspace and the World Wide Web. He offers new, specific information about kinds of hypertext, different modes of linking, attitudes towards technology, and the proliferation of pornography on the Internet. He also comments extensively on the rhetoric and style of writing in and with hypermedia.
Sensitivity of Hydrological Variables in the Northeast Pond River Watershed, Newfoundland, Canada, Due to Atmospheric Change

Watershed runoff modelling techniques were developed and applied for assessing climatic impacts, and tested for a watershed in the Northeast Pond River basin using atmospheric-change scenarios from a series of hypothetical scenarios. Results of this research strongly suggest that possible changes in temperature and precipitation caused by increases in atmospheric trace-gas concentrations could have major impacts on both the timing and magnitude of runoff and soil moisture in important natural resources areas. Of particular importance are predicted patterns of summer soil-moisture drying that are consistent across the entire range of tested scenarios. The decreases in summer soil moisture range from 10 to 50% for different scenarios. In addition, consistent changes were observed in the timing of runoff – specifically dramatic increases in winter runoff and decreases in summer runoff. These hydrologic results raise the possibility of major environmental and socio-economic difficulties and they will have significant implications for future water-resource planning and management.
Aurorae: Still in the dark

After decades of research, our understanding of the aurora is disturbingly incomplete. One long-held belief, that aurorae are much more common following each peak in the 11-year solar cycle, has now been overturned. It is also becoming more certain that discrete aurorae occur more often above dark regions of the atmosphere than above sunlit regions. Both of these discoveries support the idea that aurorae are discharge phenomena, but make it hard to explain what sort of electrical generator could be responsible.
SCOPE-a simultaneous contact and planarization etch process for low-cost high-performance CMOS applications

As CMOS device geometries shrink to below half micron sizes, contact and metal design rules have become the limiting factors for increasing circuit packing density. In order to reduce the contact and metal features accordingly, the process integration issues such as reduced thermal budget, minimized contact size, minimized contact enclosure, dielectric surface planarity, and metal step coverage in the contact must be investigated. In this work, a novel approach is employed to etch contacts and planarize the dielectric in one step. The technique is called SCOPE for Simultaneous COntact and Planarization Etch. The SCOPE process eliminate the need for oxide reflow, thereby minimizing the thermal budget after source/drain formation. It also avoids the need for extensive overetch due to the uniform contact depth, thereby allowing the misaligned contact edges on field oxides. >
On the formation and bonding of a surface carbonate on Ni(100)

Abstract The formation, stability, adsorption geometry and electronic structure of a surface carbonate on Ni(100) have been investigated by photoemission (XPS, UPS) and temperature-programmed reaction (TPR). The core level binding energies of 531.2 eV for 0(1s) and 289.0 eV for C(1s) are comparable to those of bulk carbonates. The He(II) spectrum of the carbonate valence levels is not well defined because of the coexisting adsorbed and oxidic oxygen. The angular dependence of the carbonate core level intensities is characteristic of the carbonate being present as an overlayer species rather than a thicker surface phase. The XPS data and isotope labelled TPR experiments indicate the oxygen atoms of the carbonate to be electronically and chemically equivalent, and on this basis we favor a structure in which the carbonate is attached to the metal via all three oxygen atoms. This is supported by comparision with the core level binding energies of HCOOab and chemisorbed CO2,ad, which are similarly attached to the surface. From the core level angular behavior, the close similarity of core level binding energies and available vibrational spectroscopic data, a (nearly) planar geometry of the CO3,ad on Ni(100) is concluded, which is comparable to the planar bulk carbonate anion and the planar carbonate species on Ag(110). The activation barrier for decomposition is estimated from the observed maximum in TPR at 420 K to be 25 ± 2 kcal/mol. CO2 does not accumulate on the clean or Oad-precovered Ni(100) surface at 130 K. The stabilized, chemisorbed CO2,ad species often observed on other metal surfaces therefore does not play a critical role for carbonate formation on Ni(100). Also a mechanism involving the disproportionation of a CO2… CO2,ad− dimer anion can be ruled out from TPR data. The evidence of the experiments discussed in this paper suggests that the carbonate is predominantly formed by reaction of CO2,ad with a less stable, defect (disordered) Oad species rather than with isolated oxygen adatoms or with ordered Oad in the major ordered phases of Oad or NiO present on the Ni(100) surface. A comparison is made to existing literature on the CO2/O2 interaction and carbonate formation on other transition metal and Ag surfaces. The different reactivity for formation of carbonate on Ni as compared with Ag surfaces is explained in terms of an activated reaction, where the activation barrier is determined mainly by the energetic position of the initial state of Oad and CO2,ad and where the much higher adsorption energy of oxygen on nickel is mainly responsible for the much lower reactivity on that surface.
The second-order moments of pressure-broadened hydrogen lines in the quasi-static approximation

We provide an approximate formula for the calculation of second-order moments of pressure-broadened hydrogen lines in the quasi-static approximation. Our derivation is based on the results of previous investigations of the algebraic second-order moments of polarized hydrogen lines in the presence of Stark broadening mechanisms. The approximation involved consists in considering a limited spectral range for the estimate of the second-order moment of the line profile. The problem of the formal divergence of the second-order moments of pressure-broadened hydrogen lines because of the infinite contribution from the wings is so avoided. The approximation we present seems to be robust enough for setting up a very direct diagnostics of charged perturber density in low-density plasmas, like solar prominences, based on the analysis of hydrogen line widths, if the conditions for a quasi-static treatment of pressure broadening are sufficiently well verified.
Differential expression of N-cadherin in pleural mesotheliomas and E-cadherin in lung adenocarcinomas in formalin-fixed, paraffin-embedded tissues

The differential diagnosis of pleural mesotheliomas and lung adenocarcinomas presents a continued challenge in the practice of surgical pathology. Paraffin immunohistochemistry (IHC) using different panels of antibodies can be helpful in some cases, but, as yet, no antigen is expressed specifically in mesotheliomas nor in adenocarcinomas. Using well characterized monoclonal antibodies (MAb) that recognized distinct mesenchymal and epithelial adhesion proteins, N-cadherin (13A9 MAb) and E-cadherin (E9 MAb), respectively, we found previously that in frozen-section IHC mesotheliomas and adenocarcinomas had distinct cadherin phenotypes: mesotheliomas were positive for N-cadherin, and lung adenocarcinomas were positive for E-cadherin. Using antigen-retrieval methods, we successfully extended our study to formalin-fixed, paraffin-embedded tissue sections. Tumors from 28 patients (14 originally diagnosed as mesotheliomas, and 14 diagnosed as adenocarcinomas) were stained with 13A9 MAb and E9 MAb. Review of hematoxylin-eosin sections excluded from analysis one case previously diagnosed as mesothelioma, which represented a hemangiopericytoma. Of the remaining 27 cases, 12 of 13 mesotheliomas were positive for N-cadherin and negative for E-cadherin. The exception was a multifocal microscopic papillary tumor of apparent mesothelial origin, which was negative for both N-cadherin and E-cadherin. Conversely, 13 of 14 adenocarcinomas were E-cadherin positive and N-cadherin negative except for one adenocarcinoma with focal N-cadherin expression. One case of a poorly differentiated adenocarcinoma invading skeletal muscle was negative for both 13A9 and E9. These studies confirmed the utility of the cadherin antibodies in distinguishing pleural mesotheliomas from lung adenocarcinomas. The reactivity of the cadherin-specific antibodies with antigens in paraffin sections make them powerful and reliable markers in the practice of diagnostic surgical pathology.
Achieving sustainability through attention to human resource factors in environmental management

Currently, many businesses are implementing a proactive, strategic tool known as an environmental management system (EMS) to gain a competitive advantage. Companies can no longer simply use compliance plans to deal with environmental concerns; consumer demands for greener products and services, and operational efficiencies require long term strategic and sustainable approaches for environmental management. An EMS includes documentation of: commitment and policy; planning; implementation; measurement and evaluation; and review and improvement. Establishment and maintenance of an EMS can be costly and time consuming, therefore implementation should be carefully structured to assure success. This paper identifies human resource (HR) factors such as top management support, environmental training, employee empowerment, teamwork, and rewards systems as key elements of the implementation process of an EMS. Furthermore, the interaction of these factors is examined in terms of the five categories of an EMS mentioned above. Finally, a conceptual model of the EMS‐HR factors is proposed to assist in proper facilitation of the environmental management program.
Interaction of the erythroid transcription factor cGATA-1 with a critical auto-regulatory element.

Abstract We have performed a mutational analysis of the promoter for the chicken erythroid-specific GATA-1 transcription factor, and have investigated in detail the interaction of the factor with an upstream auto-regulatory element (ARE). We find that a single proximal GATA binding site of the ARE is required for promoter activity in primary erythroid cells; however, this minimal promoter is inappropriately active in fibroblasts. At least two molecules of GATA-1 can interact with the ARE, and sequences outside of the consensus site appear critical for the transcriptional activity of the bound protein. Finally, we provide evidence for complex protein/DNA interactions at the ARE, including the ability of GATA-1 to bend DNA.
A Calculation of Ocean Heat Storage and Effective Ocean Surface Layer Depths for the Northern Hemisphere

Abstract In the hierarchy of simple ocean formulations available for coupling to atmospheric GCMs, a scheme whereby ocean surface-layer depths vary geographically and seasonally is deemed better than a fixed depth layer at all locations and seasons, but still is less sophisticated than dynamic ocean models. Yet such simple ocean formulations are useful for basic sensitivity studies. Here, a calculation of varying surface layer depths is done by first performing an ocean heat storage calculation using gridded, long-term mean mixed-layer depths and sea surface temperatures with a parameterized temperature structure beneath the mixed layer derived from weather ship data. Heat storage values in the midlatitudes are larger in the Atlantic than in the Pacific, which is in qualitative agreement with the weather ship data. Variants of the basic calculation show that neither mixed layer data nor SST data alone are sufficient to compute heat storage adequately. Using the results from the parameterized heat storage ...
Views of Haarlem: A Reconsideration of Ruisdael and Rembrandt

Jacob van Ruisdael's landscape views of the Haarlem vicinity juxtaposed with linen-bleaching fields and Rembrandt's Goldweigher's Field manifest pride in that city. The name “Haarlemmer bleek” (Haarlem bleach) was given to any linen bleached around Haarlem or neighboring communities. Only Haarlem-affiliated bleaching was depicted in such painted views even though the industry existed elsewhere. These images are analogous to contemporary maps in format — that of a bird's-eye view — and in function — depiction of a city's landmarks and industries. The unique market for Ruisdael's and Rembrandt's imagery resulted from the international success of the “Haarlemmer bleek” which was praised in poetry and city histories.
Relating indoor NO2 levels to infant personal exposures

Abstract We report here the results of a field survey of personal nitrogen dioxide exposure (PNO 2 ) of infants and simultaneous indoor NO 2 levels from various points throughout the infants' homes. Personal nitrogen dioxide levels can be predicted by average room NO 2 concentrations when appropriately weighted by infant presence in the room. Bedroom NO 2 concentration alone presents an alternative predictor which is more suitable for use in large scale surveys. Because of the typical infant's peculiar time-location patterns, they receive most of their NO 2 exposures in bedrooms (65 %)and living rooms (32 %), while the kitchen (5 %) and outdoor environments (> 2%)contribute only a small fraction of daily exposure. Average NO 2 exposure during cooking periods can be predicted using passive samplers placed directly over stoves and hours of stove use time.
Role of relaxation in epitaxial growth: A molecular-dynamics study.

The epitaxial growth of a Lennard-Jones system is studied as a function of substrate temperature ${T}_{s}$ and deposition rate. For all substrate temperatures the growth is into well-ordered layers. Layers become fully completed at intermediate ${T}_{s}$. At very low ${T}_{s}$ the layers contain defects and voids; however, the atoms are still arranged in close-packed islands within the layers.
Challenges in a Digital, Server-Based Broadcasting Environment

DIRECTV, Inc., initiated operations at its all-digital Castle Rock Broadcast Center (CRBC) in Colorado on June 17, 1994. The broadcast center contains a 512 x 12 SMPTE 259M serial digital router, controls more than 300 digital VTRs, and transmits nearly 200 channels via the DIRECTV geosynchronous direct broadcast satellites. This paper describes the issues and challenges facing DIRECTV in evolving the CRBC and its other facilities toward a server-based architecture. Tentative conclusions may change as requirements change and technology matures. It is also intended to provide a basis for industry discussion of key issues.
What is Different about International Lending

An attempt is made to explain how enforceability is achieved n international debt contracts. Each bank announces the policy of denying credit to borrowers who default and chooses to adhere to it to maintain its reputation of being a tough bank to discipline its other borrowers. Loans are made by syndicates of banks in order to make the penalty for default severe enough so borrowers would choose not to default voluntarily. The model predicts that the interest rate charged on loans is smaller for the larger borrowers. Also, for any given borrower, the interest rate may fall after each successive default. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.
Flow of non‐Newtonian fluids in a magnetic field

The analytical solution to the equation of motion is given for the steady laminar flow of a uniformly conducting incompressible non-Newtonian fluid between two parallel planes. The fluid is under the influence of a constant pressure gradient and is subjected to a steady magnetic field perpendicular to the direction of motion. Two non-Newtonian models are considered: the Bingham plastic model and the power-law model. Flow rates and the velocity profiles for various values of the Hartmann number and the generalized Hartmann number are presented and compared with those corresponding to Newtonian fluids.
Theory of the electrode effect

Abstract Numerical solutions to the set of first-order differential equations which govern the Earth's electric field near the surface are obtained by the Runga-Kutta method. The techniques employed are not restricted by many of the assumptions which must be made to obtain more analytic-type solutions. Solutions are presented for cases which allow a difference in mobility of the negative and positive ions, permit the ionization rate to change with height, and introduce an arbitrary number of condensation nuclei.
Monte Carlo Simulation of Particle-Cracking Damage Evolution in Metal Matrix Composites

In the modeling of microstructural damage mechanisms of composites, damage evolution plays an important role and has significant effects on the overall nonlinear behavior of composites. In this study, a microstructural Monte Carlo simulation method is proposed to predict the volume fraction evolution of damaged particles due to particle-cracking for metal matrix composites with randomly distributed spheroidal particles. The performance function is constructed using a stress-based damage criterion. A micromechanics-based elastoplastic and damage model is applied to compute the local stress field and to estimate the overall nonlinear response of the composites with particle-cracking damage mechanism. The factors that affect the damage evolution are investigated and the effects of particle shape and damage strength on damage evolution are discussed in detail. Simulation results are compared with experiments and good agreement is obtained.
Individualizing HbA1c targets for patients with diabetes: impact of an automated algorithm within a primary care network.

Landmark trials such as ACCORD,[1] ADVANCE,[2] and VADT,[3] have demonstrated that the benefits and harms of glycemic control are not equally distributed across all patient groups. There is increasing consensus that glycemic control goals should be based on individual patient factors.[4] However, quality reporting and pay-for-performance programs commonly evaluate diabetes outcomes using “one-size-fits-all” goals.[5] This approach may promote more aggressive management among older, sicker patients with less expected benefit and more expected harm from therapy[6], while discouraging aggressive management early in the disease course when therapy is safest and most effective. Recent American Diabetes Association (ADA) guidelines for control of hyperglycemia in type 2 diabetes explicitly abandon the use of a single glycemic goal for all patients.[4] Instead, drawing on an approach proposed by Ismail-Beigi et al.,[7] the ADA endorses a system of individualizing goals based the expected benefits and harms of therapy.[8] Recently, an analysis of data from a U.S. national population sample created an algorithm with the potential to individualize glycemic control goals.[9] However, this algorithm relied upon data from in-person interviews. This time-consuming method cannot be applied on a large scale for population level management in clinical care settings. Furthermore, the implication of individualizing goals for a large panel of patients within a health care system is unknown. For example, there is concern that performance measurement strategies may negatively affect certain clinic settings, such as “safety net” federally-qualified health centers, or vulnerable patient sub-groups, such as those with low socioeconomic status, and those for whom English is not their first language.[10, 11] This differential reclassification could divert resources from those who need it most. Finally, racial/ethnic minorities such as Hispanic and non-Hispanic Black patients may experience earlier diabetes onset[12] and have worse diabetes outcomes,[13] suggesting that optimal glycemic control is not achieved early in the disease course. Strategies that highlight more stringent diabetes control soon after diabetes diagnosis may be useful in combating disparities in diabetes outcomes[14]. To address these issues, we sought to individualize HbA1c goals using an automated health information technology process and to assess how these goals would reclassify diabetes patients in a large healthcare delivery system. We hypothesized that reclassifying patients from uncontrolled to controlled by individualizing glycemic goals would not negatively affect safety-net health centers or vulnerable populations.
Effect of Underpricing and Lock-Up Provisions in IPOs

This article examines two issues regarding initial equity public offerings (IPOs) of 775 firms that came to market between July 1, 1997, and December 31, 1999. First, a study of the underpricing of new issues indicates that first–day excess returns are greater for venture–backed IPOs, high–tech firms, and firms underwritten by top–rung investment bankers, and in months following high previous–month Nasdaq returns. Second, the authors look at the longer–run performance of IPOs and the effect of the so–called lock–up provision, which restricts initial founders and owners of the IPO from selling their shares for a period of time. They find a statistically significant increase in trading volume on the day following the unlock date. Prices begin to fall, however, prior to the end of the lock–up period as the market anticipates the selling that is likely to follow. There is a substantial negative excess return for shareholders who buy new issues in the open market immediately after the IPO.
The cannabinoid receptor: biochemical, anatomical and behavioral characterization

The actions of the active principle of marihuana, delta 9-tetrahydrocannabinol, are mimicked by synthetic cannabinoid agonists showing high potency and enantio-selectivity in behavioral assays. These drugs have been used to characterize cannabinoid receptor binding, biochemistry and pharmacology, leading to a better understanding of the effects of cannabinoids in the CNS of humans and experimental animals.
Mercury emission chemistry: the similarities or are they generalities of mercury and alkali combustion deposition processes?

Abstract The recent discovery of mercury’s propensity for heterogeneous deposition from flame burned gases shows a behavior that is strikingly similar to those previously seen for the alkali metals. The fact that these elements are located in different parts of the periodic table raises the question that common type behavior may be general among other metals. Both groups show a formation preference in their flame deposits and an insensitivity to the flame. As with the alkalis, if sulfur is present in a chlorine-free system, mercury deposits as mercuric sulfate. As sulfur is decreased, mercury has an option to additionally form its basic sulfate, Schuetteite, HgSO4 · 2HgO. If sulfur-free, it produces HgO. These processes all appear to be predominely driven by thermodynamic stabilities and are controlled by the surface and the species available. Interestingly, far more complex molecules can be formed as a surface deposit than can ever exist in the burned gases. The reduced dimensionality of the surface, its possible catalytic influence, and the introduction of condensed phase thermodynamics can induce very fast chemi-deposition with no or minimal activation energies. Unexpectedly, the rates of deposition of mercury and the five alkalis are seen to be extremely similar, indicating an insensitivity to atomic or molecular weights and also showing that these efficient processes are independent of gas phase speciation. Once formed, deposits are very stable within their formation window. They show a reluctance for reversibility but can be converted to a more stable composition by introducing additional species that were not previously present. The comparison of these two very different groups of elements shows such similar behavior that extrapolation and predictions may now be possible for other systems. It also reinforces the fact that the chemistry occurring on surfaces seems to be totally unrelated to that happening in the flame.
Gene duplications and the early evolution of neural crest development

Neural crest cells are an important cell type present in all vertebrates, and elaboration of the neural crest is thought to have been a key factor in their evolutionary success. Genomic comparisons suggest there were two major genome duplications in early vertebrate evolution, raising the possibility that evolution of neural crest was facilitated by gene duplications. Here, we review the process of early neural crest formation and its underlying gene regulatory network (GRN) as well as the evolution of important neural crest derivatives. In this context, we assess the likelihood that gene and genome duplications capacitated neural crest evolution, particularly in light of novel data arising from invertebrate chordates.
Diverse, endemic and polyphyletic clones in mixed populations of a freshwater snail (Potamopyrgus antipodarum)

Understanding the source and diversity of clones is necessary to resolve the complicated issues surrounding the apparent evolutionary stability of sexual reproduction. The source of clones is important because present theory is based on an “all else equal” assumption, which is predicated on the idea that clonal mutants are derived from and compete with local sexual populations. Clonal diversity is important because it reduces the advantage of sexual reproduction under either soft selection (the Tangled Bank Hypothesis) or under strict frequency-dependent selection (the Red Queen Hypothesis). In the present study, protein electrophoresis was used to determine the source and diversity of clones in a freshwater snail (Potamopyrgus antipodarum) in four glacial lakes in which sexual and clonal females were thought to coexist. The results showed (1) that the populations were mixtures of diploid sexual and triploid asexual individuals, (2) that genotypic diversity of clonal populations is very high in all four lakes (but lower than in the sympatric sexual populations), and (3) that the clones are polyphyletically derived from their sympatric sexual populations. Consequently, repeated mutation to parthenogenetic reproduction since the Pleistocene has introduced a different and diverse set of clones in all four lakes. Such diversity may provide a challenge for the ecological theories of sex that rely on frequency-dependent selection.
The intelligibility of deaf speech to experienced and inexperienced listeners.

The study examines differences between experienced and inexperienced listeners in understanding the speech of the deaf. Listeners heard test words in three conditions: in sentences, as isolated wor...
A 1.9 ns/6.3 W/256 Kb bipolar SRAM design

The authors describe the circuit design techniques used to demonstrate the feasibility of achieving a high-speed bipolar split-emitter MTL SRAM with 256 Kb density using ECL (emitter coupled logic) peripheral circuits. A simulated access time of 1.9 ns is achieved at 6.3 W total chip power dissipation, which is below the packaging limit for the intended applications. The minimum simulated cycle time is 3 ns. These results are based on an 0.8- mu m, 26-GHz f/sub T/, double-polysilicon self-aligned bipolar technology with calibrated NPN device models. To achieve this speed and power performance at 256 Kb density, several innovative circuit techniques are used, including an array architecture, an over-writing ECL logic circuit, an address decoder circuit with active pulldown, and bit-line discharge and restore schemes. >
The ethical analysis protocol

The Ethical Analysis Protocol focuses on major ethical issues in institutional research, affording an opportunity to examine one's own practice and to nurture ethical dialogue among researchers.
An aqueous thermodynamic model for a high valence 4∶2 electrolyte Th4+−SO42− in the system Na+−K+−Li+−NH4+−Th4+−SO42−−HSO4−−H2O to high concentration

An aqueous thermodynamic model that is valid from zero to high concentration is proposed for the Na+−K+−Li+−NH4+−Th4+−SO42−−HSO4−−H2O system. The model is based on the aqueous ion-interaction model of Pitzer and coworkers. The thorium sulfate complex species Th(SO4)2(aq) and Th(SO4)32− are also included in the model. The final thermodynamic model presented here accurately predicts all reliable thermodynamic data, including solvent extraction and solubility data, for the Na+−K+−Li+−NH4+−Th4+−SO42−−HSO4−−H2O system to high concentration. The aqueous thermodynamics of high-valence (3:2, 4:2), electrolytes are complicated by very strong specific ion interactions or ion pairing in dilute solution and by an effective redissociation of aqueous complex species at high concentration. Methods of treating these complications, in terms of valid aqueous thermodynamic models, are discussed in detail for the high-valence Th4+−SO42−−H2O system.
Control of Drug-Resistant Pathogens in Endemic Settings: Contact Precautions, Controversies, and a Proposal for a Less Restrictive Alternative

Contact precautions are routinely employed for the control of multidrug-resistant organisms. Robust measures, however, for the incremental benefit of contact precautions, gowns, gloves, and active detection and isolation strategies for the prevention of cross-transmission in endemic settings are lacking. Unintended consequences and adverse effects from contact precautions, including patient dissatisfaction with care, depression, medication errors, and fewer provider visits, have been reported. Universal gloving strategies in lieu of contact precautions have produced mixed results and raise concerns about a decrease in hand hygiene by glove wearers. We suggest that the use of a sound, horizontal infection prevention strategy that widely and consistently implements infection prevention best practices may be a sufficient and least restrictive alternative strategy for the control of endemic multidrug-resistant pathogens.
Optimal trajectories for aeroassisted, noncoplanar orbital transfer☆☆☆

Abstract This paper considers both classical and minimax problems of optimal control which arise in the study of noncoplanar, aeroassisted orbital transfer. The maneuver considered involves the transfer from a high planetary orbit to a low planetary orbit with a prescribed atmospheric plane change. An example is the HEO-to-LEO transfer of a spacecraft with a prescribed plane change, where HEO denotes high Earth orbit and LEO denotes low Earth orbit. In particular, HEO can be GEO, a geosynchronous Earth orbit. The basic idea is to employ the hybrid combination of propulsive maneuvers in space and aerodynamic maneuvers in the sensible atmosphere. Hence, this type of flight is also called synergetic space flight. With reference to the atmospheric part of the maneuver, trajectory control is achieved by modulating the lift coefficient (hence, the angle of attack) and the angle of bank. The presence of upper and lower bounds on the lift coefficient is considered. Within the framework of classical optimal control, the following problems are studied: (P1) minimize the energy required for orbital transfer; (P2) minimize the time integral of the heating rate; (P3) minimize the time of flight during the atmospheric portion of the trajectory; (P4) maximize the time of flight during the atmospheric portion of the trajectory; (P5) minimize the time integral of the square of the path inclination; and (P6) minimize the sum of the squares of the entry and exit path inclinations. Problems (P1)–(P6) are Bolza problems of optimal control. Within the framework of minimax optimal control, the following problems are studied: (Q1) minimize the peak heating rate; (Q2) minimize the peak dynamic pressure; and (Q3) minimize the peak altitude drop. Problems (Q1)–(Q3) are Chebyshev problems of optimal control, which can be converted into Bolza problems by suitable transformations. Numerical solutions for Problems (P1)–(P6) and Problems (Q1)–(Q3) are obtained by means of the sequential gradient-restoration algorithm for optimal control problems. The engineering implications of these solutions are discussed, and it appears that the energy solution (P1) and the nearly-grazing solution (P5) are superior to the remaining solutions. While the nearly-grazing solution (P5) requires more energy than the energy solution (P1), at the same time it involves less integrated heating rate, less peak heating rate, less peak dynamic pressure, and less peak total acceleration. Therefore, it is felt that both solutions (P1) and (P5) should be considered as candidates for flight operations, and hence candidates for spacecraft design.
The United States' health care system: problems and solutions.

The problems facing the U.S. health care system are not new; they have been discussed for the last 60 years. The problems have not been solved because, due to fears of government involvement, we have been reluctant to impose central planning and management on the system. Reliance on the free market and fee-for-service reimbursement to allocate health resources, to contain costs and to determine who has health insurance has failed. The result is that the U.S. spends more per capita on health services than any other country in the world, but lags behind many other countries on such health indicators as life expectancy and infant mortality. Several criteria for evaluating proposals for health reform are offered and ten such proposals are discussed. It is likely that, in the short run, the U.S. will adopt reforms that require the least change in the current system. However, these changes will not address adequately the fundamental problems with the system and, ultimately, major changes will have to be undertaken. [This article is followed by an editorial by Dr. Jonathan Trobe relating its concepts to the objectives set forth in the recently proposed Clinton Health Plan.]
Learning distributed representations of conceptual knowledge

Summary form only given, as follows. The authors argue that distributed representations must satisfy five criteria in order to serve as an adequate foundation for constructing and manipulating conceptual knowledge. These criteria are: automaticity, portability, structure encoding, semantic microcontent, and convergence. In the authors' approach, distributed representations of semantic relations (i.e. propositions) are formed by recirculating the hidden layer in recurrent parallel distributed processing networks. The authors' experiments show that the resulting distributed semantic representations (DSRs) satisfy all of the above criteria. They believe that DSRs can help supply an important building block in developing more complex connectionist architectures for higher level inferencing, as is required in natural language processing. >
Rat monoclonal antibodies to mouse lung components for analysis of fibrosis

Six rat monoclonal antibodies to mouse lung membrane fraction have been characterized. Each has unique binding properties and can be used to stain particular lung components in paraffin sections. One antibody, 133-13A, recognizes a 100-kDa glycoprotein on lung tumor cells, but stains only macrophage-like cells in normal or fibrotic lung sections as determined by immunogold electron microscopy. The monoclonal antibody 273-34A binds to a 112-kDa protein on the surface of normal mouse lung fibroblasts. Immunogold electron microscopy demonstrates antibody binding to capillary endothelial cells, but not to fibroblasts. Type I, or Type II cells. Staining of fibrotic sections with MoAb 273-34A is dramatically enhanced over staining of normal lung. A third antibody, 370-8A, gives a general staining pattern throughout normal lung that is intensified in fibrotic lung. Another MoAb 328-41A mediates intense nuclear fluorescence of lung tumor cells and cells in lung sections. It binds to 14- and 17-kDa proteins that may be high mobility group (HMG) nuclear proteins. Enzyme inhibition studies and immunofluorescence staining patterns on normal lung indicate that elastin may be the target of MoAb 328-35B. MoAb 327-5B binds to normal mouse lung fibroblasts and red blood cell membranes. These last three MoAbs stain macrophages in fibrotic lung, but give a general pattern of light epithelial cell stain in normal lung sections indicating macrophage engulfment of the normal cell antigen during fibrosis. These antibodies should be useful in identifying cell types and molecular mechanisms involved in early stages of fibrosis induced by different chemical insults.
GH mRNA levels are elevated by forskolin but not GH releasing hormone in GHRH receptor-expressing MtT/S somatotroph cell line

Abstract The MtT/S somatotroph cell line should be a growth hormone-releasing hormone (GHRH)-responsive model system for the study of physiological control of growth hormone (GH) transcription because GH secretion from these cells is stimulated by GHRH. To examine the GH transcriptional activity of these cells, endogenous GH mRNA levels were measured using a ribonuclease protection assay following treatment under a variety of hormonal conditions. While omission of serum led to reduction of GH mRNA to 22% of control levels by 2 days and to 8% by 5 days (P
Hospital Emergency Surge Capacity: An Empiric New York Statewide Study

Study objective National policy for emergency preparedness calls for hospitals to accommodate surges of 500 new patients per million population in a disaster, but published studies have not evaluated the ability of existing resources to meet these goals. We describe typical statewide and regional hospital occupancy and patterns of variation in occupancy and estimate the ability of hospitals to accommodate new inpatients. Methods Daily hospital occupancy for each hospital was calculated according to admission date and length of stay for each patient during the study period. Occupancy was expressed as the count of occupied beds. Peak hospital capacity was defined as the 95th percentile highest occupancy at each facility. Data obtained from the New York Statewide Planning and Research Cooperative System were analyzed for 1996 to 2002. Patients were classified as children (0 to 14 years, excluding newborns) or adults. Vacant hospital beds per million age-specific population were determined as the difference between peak capacity and average occupancy. Results In New York State, 242 hospitals cared for a peak capacity of 2,707 children and 46,613 adults. Occupancy averaged 60% of the peak for children and 82% for adults, allowing an average statewide capacity for a surge of 268 new pediatric and 555 adult patients for each million age-specific population. After the September 11, 2001, attacks, in the New York City region, a discretionary modification of admissions and discharges resulted in an 11% reduction from the expected occupancy for children and adults. Conclusion Typically, there are not enough vacant hospital beds available to serve 500 children per million population. Modified standards of hospital care to expand capacity may be necessary to serve children in a mass-casualty event.
Contact angle temperature dependence for water droplets on practical aluminum surfaces

Abstract This paper presents an experimental investigation of the temperature dependence of the quasistatic advancing contact angle of water on an aluminum surface polished in accordance with surface preparation techniques commonly employed in boiling heat transfer studies. The surface, speculated to contain aluminum oxide and organic residue left behind from the polishing process, was characterized with scanning electron microscopy, surface contact profilometry, and ellipsometry. By utilizing a pressure vessel to raise the liquid saturation temperature, contact angles were measured with the sessile drop technique for surface temperatures ranging from 25 to 170°C and pressures from 101.3 to 827.4 kPa. Two distinct temperature-dependent regimes were observed. In the lower temperature regime, below 120°C, a relatively constant contact angle of 90° was observed. In the high temperature regime, above 120°C, the contact angle decreased in a fairly linear manner. Empirical correlations were developed to describe this behavior which emulated previous experimental data for nonmetallic surfaces as well as theoretical trends.
Application-aware diagnosis of runtime hardware faults

Extreme technology scaling in silicon devices drastically affects reliability, particularly because of runtime failures induced by transistor wearout. Current online testing mechanisms focus on testing all components in a microprocessor, including hardware that has not been exercised, and thus have high performance penalties. We propose a hybrid hardware/software online testing solution where components that are heavily utilized by the software application are tested more thoroughly and frequently. Thus, our online testing approach focuses on the processor units that affect application correctness the most, and it achieves high coverage while incurring minimal performance overhead. We also introduce a new metric, Application-Aware Fault Coverage, measuring a test's capability to detect faults that might have corrupted the state or the output of an application. Test coverage is further improved through the insertion of observation points that augment the coverage of the testing system. By evaluating our technique on a Sun OpenSPARC T1, we show that our solution maintains high Application-Aware Fault Coverage while reducing the performance overhead of online testing by more than a factor of 2 when compared to solutions oblivious to application's behavior. Specifically, we found that our solution can achieve 95% fault coverage while maintaining a minimal performance overhead (1.3%) and area impact (0.4%).
Optical guiding simulations for high gain-short wavelength FELs

Abstract Optical guiding in the linear growth regime of an FEL amplifier has been reported in simulations by Scharlemann et al., using the LLNL 2D code FRED. We present the results of a parameter space investigation of optical guiding in an FEL using the FRED code with a realistic range of input parameters: optical wavelength, mode size and focus, current density, emittance, and wiggler period. We find that optical guiding has a profound impact on gain, and that within existing mirror technology and for the operating characteristics expected of the Stanford storage ring FEL now in construction, oscillation is achievable from the visible through 300 A. We also describe the relative importance of guiding in different regimes. In support of these predictions we present “FRED” benchmarking results.
On the origins of the hydrophobic effect: observations from simulations of n-dodecane in model solvents.

The importance of the small size of a water molecule as contributing to the hydrophobic effect is examined from simulations of n-dodecane in different solvents. The earlier observations of the origin of hydrophobicity, derived from cavity formations by Pratt and Pohorille (1992, Proc. Natl. Acad. Sci. USA. 89:2995–2999) and Madan and Lee (1994, Biophys. Chem, 51:279–289), are shown to be largely consistent for a hydrocarbon-induced water pocket. In effect, the small size of a water molecule limits the probability (and hence free energy) of finding an appropriate void in the fluid that will accommodate a solute. In this work a simulated collapse of an n-dodecane molecule in H2O, CCl4, and a water-like Lennard-Jones solvent indicates that the induced entropy and enthalpy changes are qualitatively similar for hydrogen-bonded and Lennard-Jones water solvents. These results suggest that a large part of the hydrophobic response of solutes in aqueous solutions is due to the small size of the solvent. Important quantitative differences between the studied water solvents indicate that the hydrogen-bonded properties for water are still needed to determine the overall hydrophobic response.
Update on New Antivirals Under Development for the Treatment of Double‐Stranded DNA Virus Infections

All of the currently available antiviral agents used to treat double-stranded (ds) DNA viruses inhibit the same target, the viral DNA polymerase, with the exception of interferon-α. With increasing reports of the development of resistance of herpes simplex virus, cytomegalovirus, and hepatitis B virus to some of these drugs, new antiviral agents are needed for these infections. Additionally, no drugs are approved to treat several DNA virus infections including those caused by adenovirus, smallpox, molluscum contagiosum, and BK virus. We report on the status of 10 new antiviral drugs for the treatment of dsDNA viruses. CMX-001 has broad activity against dsDNA viruses; 3 helicase-primase inhibitors, marabavir, and FV-100 have activity against certain herpesviruses; ST-246 inhibits poxviruses; GS-9191 inhibits papillomaviruses; and clevudine and emtricitabine are active against hepatitis B virus. Most of these drugs have completed at least phase I trials in humans and several are in additional clinical trials.