cssi/SciSciGPT-SciSciNet huggingface dataset:
Approximating system relations from partial information

Abstract Methods are available by which one can deduce the structure of a system, presuming that a set-theoretic decription of the global system relationship is at hand. However, if the information available about the system does not include such a description but consists of bits of partial knowledge, incomplete views, scattered facts regarding possible or impossible system configurations, knowledge of constraints on the system, and so forth, how should one proceed to deduce or approximate the system relationship? This article considers this question qualitatively and quantitatively and presents several guidelines for the effective and complete use of partial information. A measure for the amount of information provided by bits of partial knowledge and an additivity relationship for this measure are discussed. The implications of the above for the experimental method, in which the experimenter seeks to discover a system relationship by means of successive tests each of which reveals partial information about the system, are also discussed. The very po werf ul method of embedding information in the representation of a system is presented. Examples are offered to make the foregoing discussion concrete.
Crystal chemistry and superconductivity of the copper oxides

Abstract This paper highlights the important roles played by crystal chemistry in controlling the superconductive properties of the intergrowth structures of the copper oxides. Bond-length matching across the intergrowth interface stabilizes at least four different structures— T O , T′, T∗, and T″—in the simplest system La2−yLnyCuO4 (Ln = lanthanide) depending upon the size of Ln and the value of y. The internal electric field created by the formal charges in the adjacent layers modulates the distribution of holes between the active and inactive layers and the influence of Pr on superconductivity. The coordination geometry preferred by different oxidation states of Cu appears to control the oxygen ordering and the Tc variation in the YBa2Cu3O6+x system. The c-axis CuO distance modulates the width of the conduction band and the electronic properties. Chemical characterization of the thallium cuprates has demonstrated that the oxidation of the Tl2−yBa2Can−1CunO2n+4−x system can be due to either solely an overlap of the Tl:6s band with the conduction band or solely Tl vacancies, depending upon the value of y; as normally prepared, both effects are operative.
Chemicals Tested as Space Repellents Against Yellow-Fever Mosquitoes I. Esters

A total of 242 esters were tested for effectiveness as space repellents by applying them to netting with openings large enough to allow yellow-fever mosquitoes, Aedes aegypti (L.). to pass through, and determining the number of days the netting prevented passage of more than 10% of the mosquitoes to a human arm. The 5 compounds that were effective more than 100 days were: dipentyl, diisopentyl, and bis (1-methylbutyl) malate, hexyl p -isopropylmandelate, and bis (2-ethylhexyl) fumarate. Esters with a hydroxyl group appeared to be more effective than those without this group.
GMR, Structural, and Magnetic Studies in NiFeCo/Ag Multilayer thin Films

Giant Magnetoresistance (GMR), crystal structure, and magnetic properties have been investigated in a series of sputtered Ni66Fe16Co18/Ag multilayer films with induced uniaxial anisotropy. The film thickness ranges studied were 20 and 25 A for NiFeCo, and 25 to 50 A for Ag. GMR was only evident in the films after post-deposition annealing. This onset of GMR is thought to be due to the breaking up of the NiFeCo layers into ferromagnetic platelets or islands by the immiscible Ag diffusing perpendicular to the film plane along the grain boundaries. The magnitude and field sensitivity of the GMR was dependent on the annealing time and temperature. High angle x-ray diffraction (HXRD) was used to reveal the overall film structure and growth texture and low angle XRD (LXRD) was used to investigate the quality of the multilayer structures. M-H hysteresis loops revealed in-plane uniaxial anisotropy in as-deposited films which is eventually eliminated with annealing. The easy axis squareness experiences a pronounced decrease with lower temperature annealing, but then increases slightly with annealing temperature.
TIMP-1 attenuates blood-brain barrier permeability in mice with acute liver failure

Blood–brain barrier (BBB) dysfunction in acute liver failure (ALF) results in increased BBB permeability that often precludes the patients from obtaining a life-saving liver transplantation. It remains controversial whether matrix metalloproteinase-9 (MMP-9) from the injured liver contributes to the deregulation of BBB function in ALF. We selectively upregulated a physiologic inhibitor of MMP-9 (TIMP-1) with a single intracerebroventricular injection of TIMP-1 cDNA plasmids at 48 and 72 hours, or with pegylatedTIMP-1 protein. Acute liver failure was induced with tumor necrosis factor-a and D-( þ )-galactosamine in mice. Permeability of BBB was assessed with sodium fluorescein (NaF) extravasation. We found a significant increase in TIMP-1 within the central nervous system (CNS) after the administration of TIMP-1 cDNA plasmids and that increased TIMP-1 within the CNS resulted in an attenuation of BBB permeability, a reduction in activation of epidermal growth factor receptor and p38 mitogen-activated protein kinase signals, and a restoration of the tight junction protein occludin in mice with experimental ALF. Pegylated TIMP-1 provided similar protection against BBB permeability in mice with ALF. Our results provided a proof of principle that MMP-9 contributes to the BBB dysfunction in ALF and suggests a potential therapeutic role of TIMP-1 in ALF.
Statistical crystallography of surface micelle spacing

The aggregation of the recently reported surface micelles of block polyelectrolytes is analyzed using techniques of statistical crystallography. A polygonal lattice (Voronoi mosaic) connects center-to-center points, yielding statistical agreement with crystallographic predictions; Aboav-Weaire's law and Lewis's law are verified. This protocol supplements the standard analysis of surface micelles leading to aggregation number determination and, when compared to numerical simulations, allows further insight into the random partitioning of surface films. In particular, agreement with Lewis's law has been linked to the geometric packing requirements of filling two-dimensional space which compete with (or balance) physical forces such as interfacial tension, electrostatic repulsion, and van der Waals attraction.
High-Resolution Multibeam and Subbottom Surveys of Submarine Canyons, Deep-Sea Fan Channels, and Gas Seeps Using the MBARI Mapping AUV

The Monterey Bay Aquarium Research Institute (MBARI) has developed an autonomous seafloor mapping capability for high resolution mapping of the deep ocean seafloor. The MBARI Mapping AUV is a 21" diameter, Dorado class autonomous underwater vehicle (AUV) equipped with a 200 kHz multibeam sonar, 110 kHz and 410 kHz sidescan sonars, and a 2-16 kHz subbottom profiler. All components of the vehicle are rated to 6000 m depth. Using precise navigation and attitude data from an laser-ring-gyro-based inertial navigation system (INS) integrated with a Doppler velocity log sonar (DVL), the Mapping AUV can image the deep-ocean seafloor and shallow subsurface structure with much greater resolution than is possible with hull-mounted sonars. The system can also be operated in an ROV-mounted configuration, allowing near-bottom surveys in very restricted terrain. The Mapping AUV has conducted several autonomous surveys of Monterey Canyon and Smooth Ridge in Monterey Bay, and ROV-mounted surveys of five sites along the Monterey Canyon axis during 2005 and 2006. During June 2006, the Mapping AUV surveyed mounds and channel deposits in the Santa Monica Basin. The bathymetric surveys have achieved a vertical precision of 0.3 m; surveys from a 20 m altitude achieve sub-meter lateral resolution and surveys from 50-100 m altitudes achieve lateral resolutions less than 2 m. The subbottom profile data provides resolution of ~0.1 m with penetrations up to 50 m in soft sediments. The combination of high-resolution bathymetry with closely spaced subbottom profiles allow us to Additional Mapping AUV expeditions are planned for 2006, including surveys of Barclay submarine canyon and the summits of Davidson and Axial seamounts
Natural orifice transluminal endoscopic surgery gastrotomy closure with an over-the-endoscope clip: a randomized, controlled porcine study (with videos).

Background Secure endoscopic closure of transgastric natural orifice transluminal endoscopic surgery (NOTES) access is of paramount importance. The over-the-scope clip (OTSC) system has previously been shown to be effective for NOTES gastrotomy closure. Objective To compare OTSC gastrotomy closure with surgical closure. Design Randomized, controlled animal study. Setting Animal facility laboratory. Animals Thirty-six female domestic pigs. Interventions Gastrotomies were created by using a needle-knife and an 18-mm balloon. The animals were subsequently randomized to either open surgical repair with interrupted sutures or endoscopic repair with 12-mm OTSCs. In addition, pressurized leak tests were performed in ex vivo specimens of 18-mm scalpel incisions closed with suture (n = 14) and of intact stomachs (n = 10). Main Outcome Measurements The mean time for endoscopic closure was 9.8 minutes (range 3-22, SD 5.5). No complications occurred during either type of gastrotomy closure. At necropsy, examination of all OTSC and surgical closures demonstrated complete sealing of gastrotomy sites without evidence of injury to adjacent organs. Pressurized leak tests showed a mean burst pressure of 83 mm Hg (range 30-140, SD 27) for OTSC closures and 67 mm Hg (range 30-130, SD 27.7) for surgical sutures. Ex vivo hand-sewn sutures of 18-mm gastrotomies (n = 14) exhibited a mean burst pressure of 65 mm Hg (range 20-140, SD 31) and intact ex vivo stomachs (n = 10) had a mean burst pressure of 126 mm Hg (range 90-170, SD 28). The burst pressure of ex vivo intact stomachs was significantly higher compared with OTSC closures ( P P P P = .063) and ex vivo hand-sewn closures ( P = .094). In vivo surgical closures demonstrated similar burst pressures compared with ex vivo hand-sewn closures ( P = .848). Limitations Nonsurvival setting. Conclusion Endoscopic closure by using the OTSC system is comparable to surgical closure in a nonsurvival porcine model. This technique is easy to perform and is suitable for NOTES gastrotomy closure.
Enzyme Behavior and Utilization in Dairy Technology

Abstract Enzymes abound in nature, and their reactions vary from the simple to the exquisitely complex. Milk and milk products as substrates invite with increasing frequency many enzyme reactions in a receptive environment. This presentation is limited to certain topics involving enzymes that are familiar to the author through personal research or are of interest to him. It leaves largely to experts the unfamiliar or exotic enzymes and their behavior. Included in this category are genetically structured enzymes for rennet curd formation and cheese flavor enhancement. Important areas dealt with in this review involve applications of lactoperoxidase, lysozyme, and lactase; behavior of protease, chymosin, and phosphatases; accelerated cheese ripening; and ultrafiltration and enzymes. Also discussed are penicillinase production in cheeses, enzymes as analytical tools, and enzymatic transformation of cholesterol.
Chromosomal Localization of Murine and Human Oligodendrocyte-Specific Protein Genes

Oligodendrocyte-specific protein (OSP) is a recently described protein present only in myelin of the central nervous system. Several inherited disorders of myelin are caused by mutations in myelin genes but the etiology of many remain unknown. We mapped the location of the mouse OSP gene to the proximal region of chromosome 3 using two sets of multilocus crosses and to human chromosome 3 using somatic cell hybrids. Fine mapping with fluorescence in situ hybridization placed the OSP gene at human chromosome 3q26.2-q26.3. To date, there are no known inherited neurological disorders that localize to these regions.
Anatomical structure and digestibility of reed canarygrass cultivars and hybrid ryegrass

Anatomical structure and fibre chemistry influence the digestibility of forage grasses. The objective of this study was to evaluate the anatomical structure, digestibility, and fibre composition of leaf blades from a high alkaloid and two low alkaloid cultivars of reed canarygrass (Phalaris arundinacea, L.) and one cultivar of tetraploid hybrid ryegrass (Lolium hybridum, Hausskn.). Cultivars were grown in a greenhouse in a randomized complete block design with four replications. Leaf blades were either cut into 10-mm sections or dried and milled to disrupt anatomical structure. Reed canarygrass had smaller cells and airspaces and slower tissue digestion than ryegrass. The in vitro disappearance of ryegrass sections in buffered rumen fluid was 60% greater (P<0·01) than that of reed canarygrass after 6, 12 and 24 h of digestion. By contrast, the in vitro disappearance of milled ryegrass was similar to or less (P<0·05) than that of reed canarygrass. In vitro dry matter digestibility and fibre composition of the grasses were similar except for acid detergent fibre, which was greater (P<0·01) in ryegrass than in reed canarygrass. Reed canarygrass cultivars were similar in anatomical structure, digestibility, and fibre composition. It was concluded that the digestion of reed canarygrass, relative to ryegrass, was reduced by the compact arrangement of tissues and that alkaloid content did not influence the digestion of reed canarygrass cultivars.
The onset of gas pull-through during dual discharge from a stratified two-phase region: Theoretical analysis

A theoretical analysis for the onset of gas pull-through (entrainment) during discharge from a stratified two-phase region through two vertically aligned side branches has been developed in this paper. Initially, a simplified point-sink model was developed, which was then followed by the acquisition of a more accurate finite-branch model. The prediction of the critical height at the onset of gas entrainment was found to be a function of the corresponding Froude number of each branch (Fr1 and Fr2), as well as the vertical distance between the centerlines of the two branches (L/d). The predicted values of the critical height were found to be consistent with the corresponding experimental data for different values of Fr1, Fr2 and L/d. From the basis of the present models, it was found that by increasing the flow through the lower branch, the critical height increases for all values of Fr1 and L/d. Furthermore, by increasing the vertical distance between the two branches, the effect of the lower branch on the determination of the critical height was decreased.
SASSY: A Petri Net Based Student-Driven Advising Support System

This paper introduces the Course-Petri net, a specialization of Petri net which is used as the foundation for development of an advising system, SASSY. The system suggests courses for an advisee based on (i) Frequency of the course offering (ii) Balancing the course load, (iii) Shortening the path length to graduation, (iv) Preference of advisee, and (v) Entertaining different scenarios of course loads for the entire duration of the advisee’s university life. A prototype of SASSY was informally evaluated by ten advisees. The preliminary findings revealed that SASSY received approval of all advisees and it has a high potential for use in a student-centered learning environment.
Expectations and Volatility of Consumption and Asset Returns

The authors find that conditional means and variances of consumption growth vary through time, and this variation appears to be associated with the business cycle. A pricing model with fluctuating means and variances of consumption growth provides implications about conditional moments of returns for both short and long investment horizons, and these implications are explored empirically. The U-shaped pattern of first-order autocorrelations of returns, as well as business cycle patterns in the price of risk, appears to be consistent with the model, but the authors' exploration suggests that other implications about conditional return moments are at odds with the data. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.
Left atrial appendage exclusion and the risk of thromboembolic events following mitral valve surgery.

Objectives: We aimed to evaluate left atrial appendage (LAA) exclusion in patients undergoing mitral valve surgery with respect to thromboembolic events. Background: LAA is the predominant source of emboli in patients with atrial fibrillation. Prophylactic LAA exclusion at the time of heart surgery has been recommended to reduce the risk of future thromboembolism. Methods: An observational cohort of 136 patients undergoing LAA exclusion during mitral valve surgery was identified between May 1993 and November 1998 at our institution. Results: During a mean follow-up of 3.6 ± 1.3 years, there were 14 (12.3%) thromboembolic events. Compared with patients who received warfarin upon hospital discharge, there were more thromboembolic events in patients not prescribed warfarin upon hospital discharge (n = 7/67, 10% vs n = 6/40, 15%, respectively). The warfarin status was not known for one patient. The majority of thromboembolic events (n = 10/14, 71%) occurred in those who underwent mitral valve repair. Conclusion: In this observational study, patients who undergo LAA exclusion during mitral valve surgery to reduce the risk of thromboembolism have a significant incidence of thromboembolic events, especially when warfarin therapy is not prescribed upon hospital discharge.
Integrated approach to 3D warping and registration from lung images

Computerized volumetric warping and registration of 3D lung images can provide objective, accurate, and reproducible measures to the understanding of human lung structure and function. It is also invaluable to the assessment of the presence of diseases and their response to therapy. However, due to the complexity of breathing motion, little work has been carried out in this research area. In this paper, we propose an integrated approach to implement volumetric lung warping and registration from 3D CT images obtained at different stages of breathing. Both feature points and lung surfaces at consecutive frames are incorporated as a priori knowledge for 3D warping to derive an initial sparse comprehensive displacement field. This comprehensive displacement field is then interpolated over the entire volume in an iterative fashion governed by a model derived from continuum mechanics and 3D optical flow. The iteration is based on an objective function defined by a weighted sum of continuity equation, brightness constraint of 3D optical flow and motion-discontinuity-preserving smoothness constraint. Therefore, the 3D warping is accomplished by minimizing such objective function. This integrated scheme is less sensitive to the distribution of feature points and is resilient to the errors introduced in the process of feature point matching. Preliminary results are visualized by overlaying the displacement field with the original images. Effectiveness of the algorithm is also evaluated according to several checking measures. We believe the proposed approach will open up new areas of research in lung image analysis that can make use of the results from lung volumes warping.
The Use of Epoxy Resins in Field Projects for Stone Stabilization

The direct application of epoxy resins to deteriorating stone often encounters problems of penetration and color formation. Conservation scientists have worked around these problems by using organic solvents as carriers and have successfully consolidated stone with epoxy resins in a large number of projects. Work in Poland, Czechoslovakia, Italy and the United States is described. In Europe the methodology has evolved to treat objects of moderate size and isolated parts of buildings while in the United States procedures have been developed for stabilizing large portions of major buildings.
On the mathematical status of the pseudo-steady state hypothesis of biochemical kinetics☆

Pseudosteady state hypothesis for enzyme reaction kinetics justified mathematically with asymptotic expansion of Michaelis-Menten kinetic equations solution
Paleotemperature Variations across the Plio-Pleistocene Boundary.

Strong variations in the O 18 /O 16 and C 13 /C 12 ratios occur through the type section for the Plio-Pleistocene boundary, but the boundary itself is not characterized by unusual isotopic gradients.
Methionine Adenosyltransferase Deficiency: New Enzymatic Defect Associated with Hypermethioninemia

A specific deficiency of methionine adenosyltransferase has been demonstrated in the liver of an infant with hypermethioninemia. Since the enzymatic activity was below that in fetal liver and the metabolic abnormality has persisted (the infant now being 1 year of age), there is probably a genetic mutation. Mass screening for hypermethioninemia may uncover more such cases.
Configuration of inter-office switch for extreme traffic with zone configuration evaluator diagram

Abstract The problem addressed by this paper is to enable a manufacturer's representative to configure an inter-office switch with a balance of desirable functionality and measured performance under several potential extremes of traffic. The zone-configuration evaluator diagram (ZCED), a decision aid that generates the tradeoffs among different configurations, is developed to enable the switch manufacturer to forego the past practice of guaranteeing absolute performance to all of its diverse customers. This guarantee was achieved in the past by the manufacturer supporting a single conservative configuration only. The ZCED simultaneously characterizes (i) customer needs in three regimes: safety-critical, business-critical, or non-critical; (ii) extremes of traffic in terms of non-peak, average, peak, and peak–peak scenarios; and (iii) measurable performance in terms of frequency of lost transactions. Thus, a manufacturer's representative selects a configuration appropriate to the customer's individual needs and the manufacturer achieves higher revenue on the sale of desirable functions and features. A demonstration of the ZCED is developed based on a performance simulation of an actual small-office switch. The ZCED concept is readily adaptable to the configuration of other communication devices with diverse customer needs, traffic loads, and optional functionalities.
Monte Carlo and deterministic calculation of the Bell and Glasstone spatial correction factor

Abstract The Bell and Glasstone correction factor is used in subcritical assembly pulsed neutron source experiments to correct the spatial dependency of the measured reactivity on the detector position. The correction factor is defined as the ratio between the reactivity obtained by computer codes in criticality mode and that obtained by computer codes in source mode. In the area method, the reactivity (in dollar units) of a subcritical assembly is given by the ratio between the prompt and the delayed areas; these areas are obtained by integrating the detector reaction rate over the pulse period. This work illustrates different methods to calculate the Bell and Glasstone spatial correction factor using both Monte Carlo (MCNPX) and deterministic (PARTISN) computer codes. The different calculation methods include: (1) the one-simulation dynamic method (which has been applied by MCNPX computer simulations); (2) the two-simulation static method (which has been applied by both MCNPX and PARTISN computer simulations); (3) the one-simulation static method (which has been applied by MCNPX computer simulations). In the one-simulation dynamic method: (1) the external neutron source is time dependent; (2) the detector reaction rate is obtained from a single pulse and it is superimposed until the delayed neutron contribution reaches the asymptotic value; (3) the prompt area is obtained as the difference between the total and delayed areas. In the two-simulation static method: (1) the external neutron source is time independent; (2) the total and prompt areas are obtained by two separate computer simulations (one with and the other without delayed neutrons); (3) the delayed area is obtained as the difference between the total and prompt areas. In the one-simulation static method, first introduced in this study, the prompt and delayed areas are tallied in the same MCNPX simulation, which halves the computing time and reduces the statistical error relative to the two-simulation static method.
Coiled Molecules in Spring Loaded Devices

A cylindrical capsule containing a coiled alkane incorporates spacers. The alkane lengthens and gauche strain is relieved. The spacer can be removed to reset the system to the original state. The system represents a spring-loaded device that operates reversibly in response to acids and bases.
Approach to and reconstruction for lesions of the posterior third of the tongue via midline labiomandibular glossotomy

Most benign and malignant lesions of the posterior third of the tongue may be approached through a median labiomandibular glossotomy. This is accomplished by splitting the lower lip, mandible, floor of the mouth, and tongue in the midline to expose such areas as the posterior tongue, pharynx, and nasopharynx. This technique is useful for lesions of the posterior third of the tongue for several reasons: 1) it provides excellent exposure, 2) it is cosmetically superior to most other approaches, 3) it allows for several alternatives to reconstruction, such as retrusion or rotation tongue flaps, 4) the procedure sustains minimum blood loss since the tongue is bisected in the midline in an avascular plane, (5) when preoperative radiation therapy has been included, this approach minimizes the amount of surgery performed through the radiated field, and 6) postoperative tongue mobility is usually sufficient to permit articulation and deglutition to approach normal. The Cleveland Clinic Foundation's experience with this approach is reviewed, the technique is described, and a variety of cases are presented to illustrate its applicability.
Attenuation-Emission Alignment in Cardiac PET/CT with Consistency Conditions

Misaligned attenuation correction factors lead to artifacts and quantitative errors in cardiac PET images, potentially resulting in inaccurate interpretation and/or incorrect clinical decisions. Artifacts from misaligned attenuation-emission scans are common with conventional PET imaging. The potential for misalignment/artifacts is further increased in dual modality PET/CT systems since CT images a snapshot of the respiratory cycle and PET images multiple respiratory cycles. In this work, we developed and tested a method for automated alignment of attenuation and emission data. The alignment process enforces the Radon consistency conditions on the emission data and is derived from previous work by Welch et al. The attenuation image volume is aligned through simple rigid body transformations with the emission data. We test the process with simulated data and measured patient data from two ammonia cardiac PET/CT exams.
The optical properties of LiNbO3

The optical constants of LiNbO3 from 0.3 to 14.5 eV are presented from a Kramers- Kronig analysis of the near normal incidence reflectivity spectrum. Comparison with the cubic perovskites suggests that the electronic transitions from 3.5 to 12 eV are between the O2-2p valence band and Nb4+ d-like conduction band states. Higher transitions are most likely into Li+ 2s states. Sum rules are applied to calculate the effective number of electrons involved; this number is found to be consistent with the above assignment. Also, the combined density of states function is found to be very similar to that calculated for the analog compound KTaO3.
Humanizing mouse folate metabolism: conversion of the dual-promoter mouse folylpolyglutamate synthetase gene to the human single-promoter structure

The mouse is extensively used to model human folate metabolism and therapeutic outcomes with antifolates. However, the folylpoly-γ-glutamate synthetase (fpgs) gene, whose product determines folate/antifolate intracellular retention and antifolate antitumor activity, displays a pronounced species difference. The human gene uses only a single promoter, whereas the mouse uses two: P2, akin to the human promoter, at low levels in most tissues; and P1, an upstream promoter used extensively in liver and kidney. We deleted the mouse P1 promoter through homologous recombination to study the dual-promoter mouse system and to create a mouse with a humanized fpgs gene structure. Despite the loss of the predominant fpgs mRNA species in liver and kidney (representing 95 and 75% of fpgs transcripts in these tissues, respectively), P1-knockout mice developed and reproduced normally. The survival of these mice was explained by increased P2 transcription due to relief of transcriptional interference, by a 3-fold more effi...
The strain energy of fluorinated cyclopropanes: quantum chemical realization of homodesmotic, diagonal and ultradiagonal approaches

Abstract The complete series of fluorinated cyclopropanes (0–6 fluorines) were studied by ab initio (Hartree–Fock) quantum chemical calculations with the 6-311G ∗∗ basis set with explicit zero-point energies and thermal corrections. From these calculated total energies (enthalpies) and those of appropriate reference species, the strain energies of these cyclopropanes were calculated using the homodesmotic, diagonal and ultradiagonal approaches. Our results are consistent with the earlier experience (both experimental and computational) that hexafluorocyclopropane is considerably more strained than the parent hydrocarbon: other comparisons between molecules and between methods is thwarted by lack of experimental data.
Role of chromium(V), glutathione thiyl radical and hydroxyl radical intermediates in Chromium(VI)‐induced DNA Damage

Abstract In vitro chromium(VI) is unreactive toward DNA under physiological conditions. Therefore, the ability of chromium(VI) to damage DNA depends on the presence of cellular components capable of forming “reactive intermediates”; upon reaction with chromium(VI). We have examined the role of glutathione and hydrogen peroxide in chromium(VI)‐induced DNA damage in vitro. Reaction of glutathione with chromium(VI) produced significant levels of two chromium(V) complexes and glutathione thiyl radical, whereas reaction of chromium(VI) with hydrogen peroxide produced hydroxyl radical without producing detectable levels of chromium(V). Reaction of DNA with chromium(VI) in the presence of glutathione resulted in Cr‐DNA adducts with little DNA strand breakage. Reaction of DNA with chromium(Vl) in the presence of hydrogen peroxide produced the 8‐hydroxydeoxyguanosine adduct and extensive DNA strand breakage in the absence of significant Cr‐DNA adduct formation. These results suggest that the nature of chromium(VI)...
Transnuclear mice with predefined T cell receptor specificities against Toxoplasma gondii obtained via SCNT.

Mice that are transgenic for rearranged antigen-specific T cell receptors (TCRs) are essential tools to study T cell development and function. Such TCRs are usually isolated from the relevant T cells after long-term culture, often after repeated antigen stimulation, which unavoidably skews the T cell population used. Random genomic integration of the TCR α and β chain and expression from nonendogenous promoters represent additional drawbacks of transgenics. Using epigenetic reprogramming via somatic cell nuclear transfer, we demonstrated that T cells with predefined specificities against Toxoplasma gondii can be used to generate mouse models that express the TCR from their endogenous loci, without experimentally introduced genetic modification. The relative ease and speed with which such transnuclear models can be obtained holds promise for the construction of other disease models.
Survey of price elasticities from economic exploration models of US oil and gas supply

Abstract Exploration for oil or gas reserves consists of searching for and finding new reserves. It begins with the study of the geology of an area followed by exploratory or wildcat drilling in promising areas. How much oil or gas is found or the supply of new reserves is a function of exploration, the geology of the area drilled along with a random component measuring the fickleness of mother nature in yielding up her treasures to mere mortals. Knowing how oil and gas prices affect this process (price elasticities) is valuable to those who are involved with this strategic industry. Economic theory suggests that the search for petroleum is affected by prices and can be characterized by functions representing geophysical activities and drilling while the finding of reserves can be characterized by some sort of discovery process. The earliest econometric approach to modeling oil and gas exploration, which yielded price elasticities, was to estimate the search process using a function for wildcat wells drilled (Ww). For example, the discovery process for oil was represented using two equations: a success rate equation % of wells that are commercially successful (W/Ww) and an average oil reserve per successful well equation (O/W). Each of these three dependent variables were dependent on price and other relevant variables. The product of these three variables (Ww ∗ W/Ww ∗ O/W) yields the supply of oil reserves (O). In this paper we survey all U.S. exploration models for oil and gas that include wells drilled, share of successful wells, average reserves per well, or total reserve equations. We focus our survey on price elasticities to capture the effect of market price on the exploration process. Drilling equation results tend to be good with drilling strongly influenced by oil price and we suspect the long run drilling oil price elasticity to be greated than 1. It is much less clear how natural gas prices have affected drilling but their effect seems to be increasing. The most important issue in drilling equations besides including the correct economic variables is more work to clarify what geological variables provide the best forecasts. The econometric estimates for successful wells and average reserves per wells are much poorer and we would recommend more systematic work on discovery models to determine which perform the best.
Strength of composite sandwich panels containing debonds

Abstract A method for determining the critical debond size between the facesheet and the core in composite sandwich panels under in-plane compression is described. The approach uses fracture mechanics together with a buckling criterion for a debonded faceskin. The technique yields predictions for the critical in-plane compressive load for debond propagation as a function of core-to-faceskin debond size, faceskin thickness, lay-up, composite material properties, and honeycomb properties and geometries. A computer program, developed in this work, calculates the critical buckling load and facesheet deformed shape by solving an eigenvalue problem. An experimental study was conducted to determine the onset of delamination buckling in composite sandwich panels containing such flaws. Sandwich panel specimens of graphite/epoxy faceskins and aluminum honeycomb core were constructed with embedded delaminations and with varying faceskin thicknesses and core sizes. Four-point bending tests were conducted such that the faceskin containing the debond was under in-plane compression. The predicted critical fracture loads, computed using the proposed theoretical models which were solved using a numerical computational scheme, closely followed the experimental measurements.
Inability to correctly identify year or month was accurate for detecting cognitive impairment in older patients

Source Citation O’Keeffe E, Mukhtar O, O’Keeffe ST. Orientation to time as a guide to the presence and severity of cognitive impairment in older hospital patients. J Neurol Neurosurg Psychiatry. 20...
Regulation of acid phosphatase activity in the ovary of Drosophila melanogaster

Acid phosphatase (Acph) activities and protein content were measured in developing ovaries of adult flies. Acph and protein increased approximately logarithmically for the first 2 days of adult life and then plateaued at about 80 and 35 times, respectively, the levels present at eclosion. The specific activity of Acph was constant for the first 15 hr and then increased by a factor of three over the next 2 days. Analysis of staged follicles showed that the specific activity of Acph starts to increase at stage 10. Ovaries from homozygotes for Acph-1n4, a null activity mutant, showed constant low specific activity, indicating that this gene codes for the major ovarian Acph. Ovarian transplantations between Acph-1n4 and wild type showed that Acph is made by the ovary. Ovaries from isolated abdomens failed to increase in Acph activity or protein, but treating isolated abdomens with ZR-515, a juvenile hormone analog, caused nearly normal levels to be attained. Ovaries of the female sterile mutant ap4 failed to develop Acph activity unless they were implanted into a normal host or treated with ZR-515. Ovaries from the female sterile mutant fs(3)L3 developed no increase in Acph activity even when treated with ZR-515. The results demonstrate that the activity of a genetically localized enzyme is controlled by a chemically defined hormone in a genetically favorable higher eucaryote.
Characterization of an adamantyl-modified silica used as a stationary phase in high-performance liquid chromatography

Abstract An adamantyl-modified silica was packed and characterized by reversed-phase liquid chromatography. Initial studies involved a liquid chromatographic comparison of the adamantyl phase versus a conventional C18 stationary phase for a range of solutes including aromatic hydrocarbons, nitrobenzenes, phenols, anilines and pyridine derivatives. The coverage density of adamantyl groups on the silica surface is critical with regard to the retention behavior of these small molecules.
Neonatal enterovirus infection.

Enterovirus infections are probably very common during pregnancy and the first month of life. While the vast majority are likely to be benign, there is significant potential for severe neonatal morbidity and mortality. Possible subtle effects of intrauterine or mild postnatal disease have not been investigated. Much further epidemiologic work must be done before the need for effective prevention can be assessed.
Obesity and urinary incontinence: epidemiology and clinical research update.

Purpose: We reviewed the epidemiological literature on the association of obesity and urinary incontinence, and summarized clinical trial data on the effect of weight loss on urinary incontinence.Materials and Methods: We systematically searched for published community based prevalence studies with bivariate or multivariate analysis of the association of urinary incontinence and overweight/obesity in women. Case series and randomized controlled trials of the effect of surgical, behavioral and pharmacological weight loss on urinary incontinence are summarized.Results: Epidemiological studies showed that obesity is a strong independent risk factor for prevalent and incident urinary incontinence. There was a clear dose-response effect of weight on urinary incontinence with each 5-unit increase in body mass index associated with about a 20% to 70% increase in the urinary incontinence risk, and the maximum effect of weight rarely exceeded an OR of greater than 4 to 5 on well controlled analyses. The odds of in...
Work plan analysis and scheduling technique (WoPAST) — A dynamic technique for engineering program planning

The work plan analysis and scheduling technique, WoPAST technique, was developed to plan and schedule complex engineering programs when early ideas and goals are still fluid and responsibilities are general and gross. The basic techniques were adapted from other planning systems, and the approach was kept as simple as possible without sacrificing any necessary detail. It lends itself well to enhancing communications among participating people and groups and in reconciling dependencies and commitments. It compartmentalizes resource planning by a responsibility element and so avoids the lengthy cycles and iterations associated with other detailed planning techniques. After an agreement and commitment to a total plan is made, detailed monitoring and tracking is handled on a personal basis and succeeds by using peer pressure and personal identification to keep plan integrity high.
Differential effects of methionine5-enkephalin on hippocampal pyramidal cells and interneurons.

While the excitatory action of opioids and opiate drugs upon pyramidal neurons in the hippocampus is well known, the mechanism by which this excitation is achieved is still argued. A popular hypothesis is that opiates reduce the activity of inhibitory interneurons, thereby indirectly exciting the pyramidal cells. To validate this idea, it is necessary to show that opiates selectively affect the population of interneurons. The present study therefore examined the effects of met-enkephalin upon pyramidal cells and interneurons located in area CA1. Extracellular action potentials were recorded using multibarrelled micropipettes. Drugs were applied locally by either pressure micro-ejection or microiontophoresis. Met-enkephalin (10 −5 M) elevated the spontaneous discharge of pyramidal cells, while interneurons were inhibited. The responses of both types of cell were blocked by the opiate antagonist naloxone. When the synaptic connections between the pyramidal cells and interneurons were disrupted by local application of magnesium or bicuculline, met-enkephalin had no effect on the pyramidal cells. However, neither magnesium nor bicuculline altered the enkaphlin-induced inhibition of theta neurons. These results support the hypothesis that opioids of the enkephalin subclass, excite pyramidal cells in the hippocampus through a disinhibition mechanism.
The design of shape-tunable hairy vesicles

Via the use of a mesoscopic simulation technique called dissipative particle dynamics, we design sterically stable biocompatible vehicles through the self-assembly of a binary mixture composed of amphiphilic molecular species, such as PEGylated lipids, and phospholipids. We examine the factors controlling the shape of the hairy vesicle, and report the shape to change with molecular stiffness, and dissimilarity in the hydrocarbon tail groups, along with the relative concentration of the species, and the functional group length. We also draw correspondence with experimental studies on the shape transformations of the hairy vesicles through phase diagrams of the reduced volume, the ratio of the minimum and maximum radii, and the interfacial line tension, as a function of the concentration of the hairy lipids and the hydrocarbon tail molecular chain stiffness. Results from our investigations can be used for the design and prediction of novel hybrid soft materials for applications in the encapsulation and delivery of therapeutic agents.
Associations Between Macronutrient Intake and Self-reported Appetite and Fasting Levels of Appetite Hormones: Results From the Optimal Macronutrient Intake Trial to Prevent Heart Disease

The authors compared effects of macronutrients on self-reported appetite and selected fasting hormone levels. The Optimal Macronutrient Intake Trial to Prevent Heart Disease (OMNI-Heart) (2003-2005) was a randomized, 3-period, crossover feeding trial (n = 164) comparing the effects of 3 diets, each rich in a different macronutrient. Percentages of kilocalories of carbohydrate, fat, and protein were 48, 27, and 25, respectively, for the protein-rich diet; 58, 27, and 15, for the carbohydrate-rich diet; and 48, 37, and 15 for the diet rich in unsaturated fat. Food and drink were provided for each isocaloric 6-week period. Appetite was measured by visual analog scales. Pairwise differences between diets were estimated using generalized estimating equations. Compared with the protein diet, premeal appetite was 14% higher on the carbohydrate (P = 0.01) and unsaturated-fat (P = 0.003) diets. Geometric mean leptin was 8% lower on the protein diet than on the carbohydrate diet (P = 0.003). Obestatin levels were 7% and 6% lower on the protein diet than on the carbohydrate (P = 0.02) and unsaturated-fat (P = 0.004) diets, respectively. There were no between-diet differences for ghrelin. A diet rich in protein from lean meat and vegetables reduces self-reported appetite compared with diets rich in carbohydrate and unsaturated fat and can be recommended in a weight-stable setting. The observed pattern of hormone changes does not explain the inverse association between protein intake and appetite.
Primary structure, chromosomal localization, and functional expression of a voltage-gated sodium channel from human brain.

Abstract A cDNA library derived from human cerebral cortex was screened for the presence of sodium channel alpha subunit-specific clones. Ligation of three overlapping clones generated a full-length cDNA clone, HBA, that provided the complete nucleotide sequence coding for a protein of 2005 amino acids. The predicted structure suggests four homologous repeats and exhibits greatest homology and structural similarity to the rat brain sodium channel II. A second cDNA clone, HBB, that encodes a different subtype of sodium channel was isolated. Hybridization of DNA fragments from the 3' untranslated region of HBA and PCR with primers derived from HBB with human-hamster somatic cell hybrids localized these clones to human chromosome 2. In situ hybridization to human metaphase chromosomes mapped the structural genes for both HBA and HBB sodium channels to chromosome 2q23-24.3. The sodium channel HBA gene product was expressed by transfection in CHO cells. Expressed HBA currents were voltage-dependent, sodium-selective, and tetrodotoxin-sensitive and, thus, exhibit the biophysical and pharmacological properties characteristic of sodium channels.
Exploring Birth Countries: The Mental Health Implications of Heritage Travel for Children/Adolescents Adopted Internationally

Heritage trips are increasingly recognized as beneficial for children adopted internationally for myriad reasons. For example, a large percentage of adults adopted transracially during childhood report birth country travel to be a critical aspect to their ultimate development of positive racial identity. Although generally perceived to be a helpful experience for youth and families, heritage travel is not always without psychological distress. This article describes the theoretical basis for heritage travel, reviews the emerging literature on the mental health impact of heritage trips, and provides anecdotal vignettes to highlight mental health considerations and implications for heritage travel.