cssi/SciSciGPT-SciSciNet huggingface dataset:
A comparison of integral formulations for the analysis of low Reynolds number flows

Abstract Integral formulations for the analysis of low Reynolds number flows have been developed over the past 25 years. These formulations can typically be categorized as being either direct or indirect and either velocity integral equations or traction integral equations. Depending on the boundary conditions imposed for a given problem, the resulting integral formulation will result in either a Fredholm integral equation of the first kind, second kind or mixed. In general, Fredholm integral equations of the first kind lead to unstable numerical schemes based upon discretization and can result in low-order accuracy. For most practical problems, the direct velocity integral equation results in a Fredholm equation of the first kind. Nevertheless, many researchers have used this integral formulation with great success and any potential matrix ill-conditioning seems to have little influence on the accuracy of the numerical solutions. In this research, three integral formulations are compared, namely, the direct velocity integral equation, the indirect velocity integral equation, and the direct traction integral equation. Three benchmark problems are chosen for which there are analytic solutions. Although the discretized matrix condition numbers are in some cases orders of magnitude larger for the direct velocity integral formulation, there is little to distinguish between the three methods in terms of accuracy. In fact, the results for the direct velocity integral equation were slightly more accurate in most cases for the three benchmark problems considered in this research.
Technical Note: Performance of Two Hoe-Type Air Drills Sowing Green Peas in a Conservation Tillage System

A one year experiment was conducted in eastern Oregon to evaluate the performance of two different types of hoe-type air drills in terms of seeding depth uniformity, emergence, early plant growth, and crop yield when sowing green peas (Pisum sativum L.) in a tilled, leveled field. The seeding systems studied included a banded-row, flex frame air drill with seeding depth controlled by frame elevation and a single-row air drill with individual seeding unit depth control. Experimental design was a randomized complete block design with four replications. At the time of seeding, the field had approximately 5.6 t/ha of winter wheat (Triticum aestivum L.) residue on the soil surface. Depth of seed placement and date of emergence were recorded for 998 plants, while crop yield was determined by hand harvesting a 9.2-m2 area. Despite the significant differences in drill configuration, few differences in performance were found. The banded-row, flex frame air drill without individual depth gauge wheels placed seeds as accurately as the single-row air drill equipped with individual seeding unit depth control. Standard deviation of the mean seeding depth, speed of emergence index, and the percentage of sown seeds that emerged were not significantly different between the two drills. Crop yield and crop yield components including plant population, pods per plant, peas per pod, and pea weight were also not significantly different. The results of this study suggest that in leveled field conditions, there is no benefit to drills equipped with individual seeding unit depth control in terms of seed depth uniformity, seedling emergence, stand establishment, or crop yield.
Vertical-horizontal transport and fate of low water solubility chemicals in unsaturated soils

Abstract This model basically extends to two space-dimensions, all the transport and fate assumptions on the moisture, heat, and toxic chemical fields in a shallow unconfined aquifer, previously given for the vertical transport and fate model, ODWHCX (Lindstrom and Piver, 1985b).
High-level algebraic Petri nets

Abstract In this paper, a formal method for specifying and verifying concurrent and distributed systems is presented. The formal method has adapted and extended the recent research results in integrating Petri nets with algebraic specifications by incorporating guarded functions explicitly into the net definition, and offers a new technique for specification construction using the decision table technique and a new analysis technique employing logical, algebraic, and structural reasoning. The new results are illustrated through the specification and verification of a simplified lift system.
Seismic stratigraphy of the oceanic Moho based on ophiolite models

Synthetic seismograms that model vertical-incidence seismic reflections from the oceanic Moho were calculated from detailed laterally varying velocity-depth models of two ophiolite complexes. The synthetic seismograms reproduce the rapid lateral variability of waveforms, amplitudes, and two-way travel times of reflections from the oceanic Moho that are observed in existing MCS data. The large variations observed in the synthetic seismograms were caused solely by horizontal changes in the geologic structure along the crust/mantle boundary because focusing or defocusing of seismic energy by the upper crustal units was not modeled. The petrologic contrast producing the strongest reflector from the oceanic crust/mantle transition is highly variable, so it is difficult to identify what the particular Moho reflections represent geologically, although with broad-band data, velocity gradients can be distinguished from laminated zones. More important, however, is our finding that the seismic-refraction oceanic Moho and the seismic-reflection oceanic Moho usually do not coincide and that either or both may cross major geologic contacts.
A simple TOPMODEL-based runoff parameterization (SIMTOP) for use in global climate models

[1] This paper develops a simple TOPMODEL-based runoff parameterization (hereinafter SIMTOP) for use in global climate models (GCMs) that improves the runoff production and the partitioning of runoff between surface and subsurface components. SIMTOP simplifies the TOPMODEL runoff formulations in two ways: (1) SIMTOP represents the discrete distribution of the topographic index as an exponential function, not as a three-parameter gamma distribution; this change improves the parameterization of the fractional saturated area, especially in mountainous regions. (2) SIMTOP treats subsurface runoff as a product of an exponential function of the water table depth and a single coefficient, not as a product of several parameters that depend on topography and soil properties; this change facilitates applying TOPMODEL-based runoff schemes on global scale. SIMTOP is incorporated into the National Center for Atmospheric Research (NCAR) Community Land Model version 2.0 (CLM 2.0). SIMTOP is validated at a watershed scale using data from the Sleepers River watershed in Vermont, USA. It is also validated on a global scale using the monthly runoff data from the University of New Hampshire Global Runoff Data Center (UNH-GRDC). SIMTOP performs favorably when compared to the baseline runoff formulation used in CLM2.0. Realistic simulations can be obtained using two distinct saturated hydraulic conductivity (Ksat) profiles. These profiles include (1) exponential decay of Ksat with depth (as is typically done in TOPMODEL-based runoff schemes) and (2) the definition of Ksat using the soil texture profile data (as is typically done in climate models) and the concordant reduction of the gravitational drainage from the bottom of the soil column.
Hormonal control of glycogen in the heart and other tissues in rats.

THE glycogen of the heart, unlike that of other tissues, has often been found to be greater in amount in the fasting animal than in the fully fed subject (Macleod and Prendergest, 1921; Evans, 1934; Bong, Junkersdorf and Steinborn, 1934; Lackey, Bunde, and Harris, 1946). Illingworth and Russell (1951) observed further that the cardiac glycogen of fasting hypophysectomized rats was lower than that of normal animals similarly fasted and that this difference could be overcome to a considerable degree by treatment with purified growth hormone during the fasting period. Also the cardiac glycogen of intact fasting rats was increased after the acute administration of growth hormone. These observations suggested that the activity of one or more pituitary hormones might be concerned with the increase in cardiac glycogen which is induced by fasting, and the experiments below were undertaken primarily as a further investigation of this point. In the same animals, glycogen was determined also in the gastrocnemius mus...
Evaluating the impact of non-lethal DNA sampling on two butterflies, Vanessa cardui and Satyrodes eurydice

Genetic sampling of endangered species can inform conservation management and potentially aid the long-term survival of a species. However, when dealing with very small populations of rare species, the sacrifice of whole animals may not be desirable or permitted. We set out to develop a demonstrably non-lethal method of obtaining DNA from the federally-endangered Mitchell’s satyr butterfly, Neonympha mitchellii mitchellii. Because of its endangered status we developed our methods on related species. In greenhouse and fields trials, we demonstrate that removal of small amounts of hind wing (2–3 mm2) has no significant impact on the behavior or survival of Vanessa cardui and Satyrodes eurydice. Based on these studies we were successful in obtaining a permit from the US Fish and Wildlife Service to sample DNA from N. m. mitchellii populations. We suggest that our results can be extended to the sampling of other rare butterfly species.
Potentiation of ethanol-induced lipid peroxidation of biological membranes by vitamin C.

The hydroxyl free radical (/sup ./OH) was generated by the system of ADP-Fe/sup + +/ and H/sub 2/O/sub 2/, trapped by 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and analyzed by electron spin resonance (ESR) spectroscopy. The addition of vitamin C to the system decreased considerably the amount of hydroxyl adduct of DMPO formed. In the presence of ethanol, the ESR spectrum observed was a composite signal of the hydroxyl and hydroxyethyl (HE) adducts of DMPO. However, in the presence of vitamin C and ethanol, pure HE adduct of DMPO was detected. We also detected the increase in lipid peroxidation in the presence of ethanol and vitamin C. These data lead us to hypothesize that in the biological system, formation of these long-lived HE free radicals may result in membrane damage due to an increase in lipid peroxidation.
An extension of Fibonaccian search to several variables

A technique which uses Fibonaccion search concepts has been developed to solve optimization problems involving unimodal functions of several variables. The technique has not been proven to be optimal in the sense that the one-dimensional Fibonaccion search is. However, it is valuable for certain kinds of calculations.
Center-manifold reduction for laser equations with detuning

An improved adiabatic elimination technique, previously applied to resonant-laser equations for a small population decay rate, is extended to the general detuned case. The initial five-dimensional system is approximated with a set of only two differential equations. This allows an analytical investigation of the bifurcation properties of the second laser threshold. The final two-dimensional model represents a substantial improvement in the correct description of many lasers, from ${\mathrm{CO}}_{2}$ to Nd:YAG (YAG denotes yttrium aluminum garnet), from semiconductor to NMR lasers.
PMN-kinin and kinin metabolizing enzymes in normal and malignant leucocytes

1. Studies have been carried out on the kinin-forming and kinin destroying activity of rabbit macrophages obtained from the lung before and after BCG injection and from the peritoneal cavity following mineral oil injection. A similar study was carried out with L-1210 leukaemic cells obtained from the peritoneal cavity of mice. 2. The macrophages and leukaemic cells contain enzymes that form kinins from purified kininogen substrates at acid pH. The kinin-forming activity is not limited to the lysosomal fraction of the cell since it is found in extralysosomal compartments. Delta-guanidovaleryl benzyl ester partially inhibits the kinin-forming activity. Trasylol does not inhibit the kinin-forming activity of these cells, but does inhibit the kininases of these cells. The lack of effectiveness of this agent as a general anti-inflammatory agent is thus explained. 3. The kininases of the normal and malignant cells are also inhibited by chloromethyl ketones such as tosyl-lysine chloromethyl ketone (TLCK) and tosyl-phenylalanine-chloromethyl ketone (TPCK) as well as by copper salts. Hydroxyquinoline has no inhibitory action on these cells, indicating that they differ from the plasma kininases. 4. Investigation of the kinins produced by enzymes in rabbit and human polymorphonuclear (PMN) cells has demonstrated the formation of a kinin that differs from bradykinin and other known mammalian kinins in its pharmacological properties, molecular weight, and amino-terminal end group. This peptide has been named PMN-kinin. 5. Overall, the investigation has demonstrated the importance of white cells in contributing to the formation and destruction of “extra-plasma” sources of kinins by enzymes which differ from plasma enzymes. Anti-inflammatory agents may have different actions on these cell enzymes from those on plasma enzymes.
Atmospheric mercury over the NE Pacific during spring 2002: Gradients, residence time, upper troposphere lower stratosphere loss, and long-range transport

[1] Gaseous elemental mercury (GEM) was measured over the North Pacific and coastal California, Oregon and Washington in spring 2002 during the Intercontinental Transport and Chemical Transformation Experiment–2002 (ITCT2K2). Observations were made from the NOAA WP3 on 11 flights which spanned an altitude range of 0–8 km and latitudes between 35 and 55°N. GEM was determined using a Tekran 2537A mercury instrument modified for airborne use to collect and analyze samples every 2.5 min under variable ambient temperature and pressure conditions. GEM concentrations were in general at the low end of previous measurements made over continents and in fresh continental outflow over the ocean. They showed (1) a significant vertical gradient in GEM between the lower sample altitudes and the upper altitudes, with median concentrations decreasing from 1.2 to 0.5 ng m−3; (2) GEM was depleted in upper troposphere lower stratospheric air and indicated this region is a sink for GEM; (3) GEM concentrations were ∼1/2 at the surface to ∼1/4 at midaltitudes of those observed immediately downwind of Asia during ACE-Asia, however; (4) highest GEM concentrations (∼4 ng m−3) were found in plume layers at concentrations comparable to those observed off the Asian coast in ACE-Asia; and (5) the observed variance in GEM suggested a lifetime on the order of 100 days, which was shorter than the previously accepted nominal lifetime of 1 year.
Structural Insights into Riboswitch Control of the Biosynthesis of Queuosine, a Modified Nucleotide Found in the Anticodon of tRNA

Summary The modified nucleotide queuosine (Q) is almost universally found in the anticodon wobble position of specific tRNAs. In many bacteria, biosynthesis of Q is modulated by a class of regulatory mRNA elements called riboswitches. The preQ 1 riboswitch, found in the 5′UTR of bacterial genes involved in synthesis of the Q precursors preQ 0 and preQ 1 , contains the smallest known aptamer domain. We report the solution structure of the preQ 1 riboswitch aptamer domain from Bacillus subtilis bound to preQ 1 , which is a unique compact pseudoknot with three loops and two stems that encapsulates preQ 1 at the junction between the two stems. The pseudoknot only forms in the presence of preQ 1 , and the 3′ A-rich tail of the aptamer domain is an integral part of the pseudoknot. In the absence of preQ 1 , the A-rich tail forms part of the antiterminator. These structural studies provide insight into riboswitch transcriptional control of preQ 1 biosynthesis.
Enforcing Information Flow Security Properties in Cyber-Physical Systems: A Generalized Framework Based on Compensation

This paper presents a general theory of event compensation as an information flow security enforcement mechanism for Cyber-Physical Systems (CPSs). The fundamental research problem being investigated is that externally observable events in modern CPSs have the propensity to divulge sensitive settings to adversaries, resulting in a confidentiality violation. This is a less studied yet emerging concern in modern system security. A viable method to mitigate such violations is to use information flow security based enforcement mechanisms since access control based security models cannot impose restrictions on information propagation. Further, the disjoint nature of security analysis is not appropriate for systems with highly integrated physical and cyber infrastructures. The proposed compensation based security framework is foundational work that unifies cyber and physical aspects of security through the shared semantics of information flow. A DC circuit example is presented to demonstrate this concept.
Newly described, difficult-to-identify, catalase-negative, gram-positive cocci

Abstract Although the frequency at which these newly described gram-positive cocci occur in human infections is unknown, it is fairly certain that they are significant pathogens for humans. In addition, there is some indication that there may be differences in the antimicrobial susceptibility of the different species; therefore, identification of the species may be important for management of infections. The number of conventional tests needed for presumptive identification at this time is not great and would fit into the workload of most clinical microbiology laboratories. Until more isolates of the newly described species are examined, the identification procedures should be treated as presumptive. Additional antimicrobial susceptibility testing and standardization of antimicrobial susceptibility tests should give a more clear answer as to whether or not identification to the species level is important for these groups of bacteria.
Theoretical phosphorylation rates after addition of a small amount of glucose to intact ascites tumor cells.

Abstract Changes were measured in glycolytic and respiratory rates during the entire period of glycolysis and respiratory inhibition after addition of 0.08 or 0.15 mM glucose to Ehrlich ascites carcinoma cells in 54 mM phosphate buffer (pH 7.3) at 37°. Glycolytic products fully accounted for the glucose utilized. Theoretical rates of glycolytic ATP synthesis were calculated from the rates of accumulation of glycolytic products, and rates of oxidative phosphorylation were calculated from respiratory rates, assuming a P:O ratio of 3.0. The maximum in the glycolytic phosphorylation rate curve preceded the minimum in the respiratory phosphorylation rate curve. As a consequence, the total phosphorylation rate curve was biphasic, first rising above, then falling below, and finally returning to the initial, pre-glucose rate. The area under the early rise approximately equalled the area above the later dip and corresponded to between 1 and 2 μmoles of ATP/ml cells. The low rate of change in the ATP content of the cells indicated that most of the change in phosphorylation rate represented changes in both ATP synthesis and ATP utilization. It is hypothesized that ATP synthesized by glycolysis is more readily available to the ATP-utilizing systems. On addition of glucose, ATP is shifted from a respiratory to a glycolytic reservoir and a period of more rapid ATP utilization associated with a decrease in the level of endogenous substrates involved in the ATP-utilizing reactions ensues; after cessation of glycolysis, the process is reversed, and ATP utilization is slowed for a period while the endogenous substrates increase again.
Perceptions of early childhood teachers and parents of teacher–parent interactions in an Indian context

The study assessed the nature of parent–teacher interactions of preschool teachers in India with parents of preschool children. Specifically, the impact of teacher training, satisfaction with training and the job, years of experience and class size on the nature of interactions with parents were examined. Perceptions of both parents and teachers were sought. Sixty‐five preschool teachers and 173 parents from an urban city in India comprised the total sample. Results using teacher reports indicated that 32% of the variance was accounted for. Satisfaction with training and the job emerged as significant, while the amount of training, years of experience and class size did not. According to parent reports, 24% of variance was accounted, and where only one variable emerged significant. Amount of training of teachers inversely impacted the nature of teacher–parent interactions. These findings suggested the interplay of specific factors like limited space, finances and cultural notions of teaching/education, an...
Measurement of the contributions of high- n satellite lines to the K β lines of He-like Ar 1 6 +

We have measured the contributions from high-n dielectronic satellite lines to the 1${\mathit{s}}^{2}$--1s3p${\mathrm{}}^{1}$${\mathit{P}}_{1}$ resonance line of heliumlike ${\mathrm{Ar}}^{16+}$. Using a high-resolution crystal spectrometer to analyze the x-ray emission of ions trapped and excited in an electron-beam ion trap, contributions from satellite levels of the type 1s3${\mathit{lnl}}^{\ensuremath{'}}$-1${\mathit{s}}^{2}$${\mathit{nl}}^{\ensuremath{'}}$, for n=3,4,5 and n\ensuremath{\ge}6, have been recorded. The resonance strength of the n=3 satellites was measured to be (4.65\ifmmode\pm\else\textpm\fi{}0.67)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}21}$ ${\mathrm{cm}}^{2}$ eV. The resonance strength of the n=4 satellites was determined to be larger than that of the n=3 satellites and that of the n=5 satellites was found to be nearly equal to the resonance strength of the n=3 satellites. The ${\mathit{n}}^{\mathrm{\ensuremath{-}}3}$ dependence of resonance strengths expected from the n scaling of the Auger rates is thus shown to not be valid for the satellites studied in our measurements. \textcopyright{} 1996 The American Physical Society.
Effect of thrombin on cyclic AMP content in glomeruli isolated from rat kidney

Effect of thrombin on cyclic AMP content in glomeruli isolated from rat kidney. Localized thrombin-mediated intravascular coagulation has been implicated as an important pathogenetic factor in a variety of glomerular and vascular diseases of the kidney. Recent studies indicate that glomerular function is affected by several hormonal agents which alter the cyclic AMP or cyclic GMP content in the glomeruli. Although thrombin has been shown to affect several metabolic processes in other cellular systems the possibility that thrombin may cause a reduction in glomerular function by altering cyclic nucleotide metabolism has not been previously considered. We therefore examined the effect of thrombin on the cyclic AMP and cyclic GMP content in glomeruli isolated from rat renal cortex. Thrombin caused a dose dependent (0.01 to 1 U/ml) increase in the cyclic AMP content in the glomeruli but had no effect on the cyclic GMP content. The effect was first observed at 30 seconds and reached a peak at five minutes. Tubules isolated from the same rats had no response to thrombin. The glomerular cyclic AMP response to thrombin inactivated with diisopropylfluorophosphate was markedly impaired, indicating the requirement for the protease activity of thrombin for the observed effect. Thrombin did not affect the cyclic AMP phosphodiesterase activity in glomeruli Thrombin-mediated increase in glomerular cyclic AMP may play an important role in the reduction in glomerular function that is observed in a variety of glomerular and vascular renal diseases in which intravascular coagulation plays a prominent role.
Neoplastic risk among workers exposed to vinyl chloride.

As early as 1930 the first adverse health effects of vinyl chloride (VC) were reported.' Since then, numerous observations and studies have indicated a wide range of toxicity attributable to the effects of VC on the central nervous system, the liver, the bones of the fingers, and the Lately, the spectrum of known toxic effects of VC broadened to include malignant neoplasms. Viola et al.," in 1971, reported the induction of tumors of the skin, lungs, and bones in rats exposed by inhalation to 30,000 ppm of VC for twelve months. However, widespread acceptance of the carcinogenic activity of VC did not occur until early in 1974 after the announcement of three cases of liver angiosarcoma among workers at a single VC polymerization facility in the U.S.A." About the same time, Maltoni reported the same cancerous hepatic effect in animals following exposure by inhalation to VC.13 Shortly thereafter, Maltoni and Lefemine l 4 and Keplinger et al.15 reported the induction of tumors of the brain, kidney, liver, lung, and lymphatic system in mice, rats, and hamsters exposed to VC by inhalation. Consequently, an epidemiological evaluation was undertaken by the National Institute for Occupational Safety and Health (NIOSH) to assess the magnitude and spectrum of neoplastic effects in workers exposed to VC. This study included industrial hygiene surveys, retrospective cohort analyses of mortality patterns, and histopathologic evaluation of tumors.
Occurrence and predictors of dexmedetomidine infusion intolerance and failure.

AbstractBackground: Dexmedetomidine, a selective α2 adrenergic receptor agonist, exhibits sedative, analgesic, anxiolytic, and sympatholytic effects, and may aid in controlling agitation in the intensive care unit (ICU). At our hospital (Barnes-Jewish Hospital, St. Louis, MO), dexmedetomidine is commonly used as a sedative in the medical ICU. Predictors of dexmedetomidine intolerance or failure have not yet been defined. Objective: Describe the rate of dexmedetomidine infusion intolerance/failure and identify patient predictors of intolerance/failure. Methods: This retrospective single-center cohort study evaluated 75 mechanically ventilated adults who received dexmedetomidine infusion. Patients were included in the study if they were aged ≥ 18 years; mechanically ventilated for > 24 hours; received dexmedetomidine infusion for ≥ 1 hour following > 24 hours of continuous infusions of midazolam, fentanyl, or propofol; and were admitted to our medical ICU between August 1, 2009 and August 1, 2010. Multivari...
Equimomental system of rigidly connected equal particles

Introduction T WO rigid systems are said to be equimomental if their dynamic behaviors are identical. More specifically, equimomental dynamic systems possess the same total mass, location of center of mass, principal directions, and mass moments of inertia. For a three-dimensional rigid body, it is necessary to have at least four particles to represent its dynamic behavior. However, for a two-dimensional rigid body only three particles are needed in the equimomental system. The study of the equimomental system is not new. Routh investigated the problem of equimomental system of particles nearly a century ago. He concluded that the equimomental particles must lie on the surface of an equimomental ellipsoid which is centered at the center of mass of the rigid body. Routh pointed out that the equimomental system formed a tetrahedron with four equal particles. Each particle has a mass equal to one-fourth of the total mass and is placed at the vertex of the tetrahedron. If the equimomental ellipsoid is mapped onto a sphere by changing scales in the directions of coordinate axes, then the tetrahedron would be mapped onto a regular tetrahedron inscribed in the sphere. As the result of spherical symmetry, the orientation of the image tetrahedron remains arbitrary. Thus, the location of equimomental particles is not unique. The number of degrees of freedom is three in the three-dimensional problem and is one in the two-dimensional problem. Routh gave some examples of determination of the position of a particular set of equimomental particles through some simple mathematical manipulations. However, no procedure is presented for locating the general position of equimomental particles. Other particular solutions of equimomental systems are also given by Whittaker and Greenwood. This Note presents a general procedure for locating the equimomental particles. Our solution will be expressed in terms of orientation parameters corresponding to the degree of freedom of the problem.
Plasticity effects on frame member reliability

Abstract This paper proposes a computational procedure to correctly construct the nonlinear limit state and estimate the reliability of members in ductile framed structures. Due to the uncertainties in loads and structural properties, the structure could be in one of many different damage states before failure occurs in the member of interest. Since the enumeration of all these damage states and the computation of their effect on member reliability is tedious, the proposed method uses three criteria based on the statistical relationships among the members to efficiently identify those damage states that significantly affect the reliability of the desired member. This is used to determine the polyhedral envelope of the entire failure domain, corresponding to various levels of cumulative damage. The failure probability is then estimated through the union of failure domains defined by each of the linear segments of this polyhedral surface, using second-order bounds.
Light Quanta and Wave Mechanics

Light quanta are treated by wave mechanics by analogy with electrons. It is shown that their wave equation is the ordinary optical wave equation. Heisenberg's principle of indeterminateness becomes a description of diffraction. In problems in which localization of quanta is found experimentally, wave packets are to be set up; these are applied to the experiments of Bothe and Geiger, and of Compton. The paths of quanta coincide with the rays of geometrical optics, with a deviation of the error in geometrical optics; by the principle of indeterminateness, more accurate laws for the paths are neither necessary nor possible.
Cost effective analysis of prenephrectomy radioisotope scans in renal cell carcinoma ARIE LINDNER, M.D.

To evaluate the cost-effectiveness of liver and bone isotope scans, results of scans were reviewed in 60 patients with renal cell carcinoma. In no patient did the results of the scans influence or change the treatment plan. Routine utilization of radioisotope scans as part of the preoperative evaluation of patients with renal cell carcinoma should be discouraged.
Transgenic animals: current and alternative strategies.

Transgenic animal technology is one of the most fascinating technologies developed in the last two decades. It allows us to address questions in life sciences that no other methods have achieved. The impact on biomedical and biological research, as well as commercial interests are overwhelming. The questions accompanying this fast growing technology and its diversified applications attract the attention from a variety of entities. Still, one of the most fundamental problems remaining is the search for an efficient and reliable gene delivery system for creating transgenic animals. The traditional method of pronuclear microinjection has displayed great variability in success among species. While an acceptable efficiency in the production of transgenic mice has been attained, the relative low efficiency (<1%) in creating transgenic livestock has become one of the barriers for its application. In the past decades, improvements in producing transgenic livestock have made a slow progression, however, the recent...
U.S. and Australian public libraries and the Internet: connectivity issues and policy implications

This paper presents findings from two separate public library Internet connectivity surveys conducted in the United States and Victoria, Australia. The primary survey goals were to assess U.S. and Victoria public library involvement with and use of the Internet. The surveys found considerable progress in U.S. and Victoria public library Internet connectivity. This article argues, however, that connectivity is not the same as the provision of network-based services. Thus, this article identifies issues that public librarians, policy makers, and researchers should consider as public libraries make the transition to the electronic networked environment and increasingly provide electronic services.
Reconstructions in impedance and optical tomography with singular interfaces

Singular layers modelled by a tangential diffusion process supported on an embedded closed surface (of co-dimension 1) have found applications in tomography problems. In optical tomography they may model the propagation of photons in thin clear layers, which are known to hamper the use of classical diffusion approximations. In impedance tomography they may be used to model thin regions of very high conductivity profile. In this paper we show that such surfaces can be reconstructed from boundary measurements (more precisely, from a local Neumann-to-Dirichlet operator) provided that the material properties between the measurement surface and the embedded surface are known. The method is based on the factorization technique introduced by Kirsch. Once the location of the surface is reconstructed, we show under appropriate assumptions that the full tangential diffusion process and the material properties in the region enclosed by the surface can also uniquely be determined.
The use of self-mating PEEK as an alternative bearing material for cervical disc arthroplasty: a comparison of different simulator inputs and tribological environments

Purpose The hypothesis for this study was that the simulated wear behavior of a hydroxyapatite coated, self-mating PEEK cervical disc arthroplasty device would be dependent on the simulated testing environment.
Charles W. Bachman: Database Software Pioneer

Bachman's career was long, varied, and distinguished. He ran a chemical plant, created a capital accounting systems, headed an early data processing group, pioneered the application of computers to manufacturing control, led efforts to standardize database and computer communication concepts, won the highest honor in computer science, and founded a publicly traded company. Innovation is a collaborative process, but by creating IDS and advocating forcefully for the concepts behind it Bachman did more than any other person to invent the DBMS as we know it today. Through all of this he retained an engineer's zest for the elegant solution of difficult problems and faith in the power of careful analysis and the systems approach to make the world a better place.
RLIP76 is the major ATP-dependent transporter of glutathione-conjugates and doxorubicin in human erythrocytes.

Abstract We have recently demonstrated that RLIP76, a Ral-binding GTPase activating protein mediates ATP-dependent transport of glutathione (GSH) conjugates of electrophiles (GS-E) as well as doxorubicin (DOX), and that it is identical with DNP-SG ATPase, a GS-E transporter previously characterized by us in erythrocyte membranes (Awasthi et al. Biochemistry 39, 9327–9334). Multidrug resistance-associated protein (MRP1) belonging to the family of the ABC-transporters has also been suggested to be a GS-E transporter in human erythrocytes. Using immunological approaches, the present studies were designed to elucidate the relative contributions of RLIP76, MRP1, and P-glycoprotein (Pgp), in the ATP-dependent transport of GS-E and DOX in human erythrocytes. In Western blot analyses using antibodies against RLIP76, a strong expression of RLIP76 was observed in erythrocytes. Immunohistochemical studies using a fluorescent probe showed association of RLIP76 with erythrocyte membrane, which was consistent with its transport function. Neither MRP1 nor Pgp were detected in erythrocytes when the antibodies against MRP1 or Pgp were used. In erythrocyte inside-out vesicles (IOVs) coated with antibodies against RLIP76, a dose-dependent inhibition of the ATP-dependent transport of DOX and GS-E, including S -(dinitrophenyl)glutathione (DNP-SG), leukotriene C 4 , and the GSH conjugate of 4-hydroxynonenal, was observed with a maximal inhibition of about 70%. On the contrary, in the IOVs coated with the antibodies against MRP1 or Pgp no significant inhibition of the ATP-dependent transport of these compounds was observed. These findings suggest that RLIP76 is the major ATP-dependent transporter of GS-E and DOX in human erythrocytes.
A BIBLIOGRAPHICAL NOTE ON ENERGY CONSERVATION AND HISTORIC PRESERVATION

Old buildings generally have been preserved or restored in order to maintain the heritage of the American people. Buildings with historical significance in design or architecture have been preserved. Basically, preservation has centered on the cultural and aesthetic. Recently, much of the historic preservation literature has begun to delineate the economic benefits of preservation. There are three basic areas of preservation economics. They are a) adaptive use, b) taxation, and c) energy conservation. Much of the literature is concerned with adaptive use although there are certain tax benefits from preservation as well as energy savings. Each of these areas is outlined, but the emphasis of this paper is to review the literature concerning energy conservation.
Discourse Patterns During Children’s Collaborative Online Discussions

This article examines the discourse of 10 groups of children during text-based online discussions. Analysis of the discourse in the discussions showed that 8 different rhetorical moves, or argument stratagems, were used by most groups of children, whereas 3 other stratagems were used by 1 group. The use of argument stratagems snowballed; that is, once an argument stratagem emerged in a discussion, it tended to spread to other children in the Web group, and the likelihood that it would occur again remained high over the course of the discussion. Most stratagems began to spread when initiated by other children but not when introduced by the adult moderator. Children were eager to participate and displayed a high rate of participation in discussions with Webmates from distant classrooms. These findings suggest that collaborative online discussions may provide an effective instructional medium for promoting children's learning of reasoning strategies and thinking skills. We wish to acknowledge the contributio...
Antibiotic prescribing for presumed nonbacterial acute respiratory tract infections.

Abstract Objective The objective of the study was to identify patient and provider factors associated with prescribing antibiotics for outpatients with acute respiratory tract infections of likely nonbacterial etiology. Methods We identified outpatients who were diagnosed in the emergency department with nonspecific upper respiratory tract infections (URIs) and acute bronchitis at the VA Pittsburgh Healthcare System from June 15, 2003, to June 14, 2004, and the Philadelphia VA Medical Center from November 30, 2003, to March 31, 2004. Stepwise logistic regression was used to identify factors independently associated with antibiotic prescribing. Results Overall, 26% of the 667 eligible patients with URIs and/or acute bronchitis received antibiotics. Antibiotics were prescribed significantly more frequently for acute bronchitis at one site (97% vs 65%, P Conclusions Antibiotic use was high and varied substantially for URIs and acute bronchitis. Specific signs and symptoms, a diagnosis of acute bronchitis, and provider age and specialty were associated with antibiotic prescribing. Interventions to decrease inappropriate prescribing should address the perceived utility of antibiotics in acute bronchitis and the accuracy of signs and symptoms in diagnosing a bacterial respiratory infection.
Cholinergic modulation of synaptic integration and dendritic excitability in the striatum

Modulatory interneurons such as, the cholinergic interneuron, are always a perplexing subject to study. Far from clear-cut distinctions such as excitatory or inhibitory, modulating interneurons can have many, often contradictory effects. The striatum is one of the most densely expressing brain areas for cholinergic markers, and actylcholine (ACh) plays an important role in regulating synaptic transmission and cellular excitability. Every cell type in the striatum has receptors for ACh. Yet even for a given cell type, ACh affecting different receptors can have seemingly opposing roles. This review highlights relevant effects of ACh on medium spiny neurons (MSNs) of the striatum and suggests how its many effects may work in concert to modulate MSN firing properties.
Long-term c i / c a response of trees in western North America to atmospheric CO 2 concentration derived from carbon isotope chronologies

To evaluate how the land carbon reservoir has been responding to the rising CO2 concentration of the atmosphere, it is important to study how plants in natural forests adjust physiologically to the changing atmospheric conditions. Many experimental studies have addressed this issue, but it has been difficult to scale short-term experimental observations to long-term ecosystem-level responses. This paper derives carbon-isotope-related variables for the past 100–200 years from measurements on trees from natural forests. Calculations show that the c i/c a ratios [c i/c a is the ratio of the CO2 concentration (μmol mol−1) in the intercellular space of leaves to that in the atmosphere] of the trees were constant or increased slightly before the 20th century, but changed more rapidly in the 20th century; some increased, some decreased, and some stayed constant. In contrast, the CO2 concentration inside plant leaves increased monotonically for all trees.
An incidental case of dihydropyrimidine dehydrogenase deficiency: One case, multiple challenges

Dihydropyrimidine dehydrogenase (DPD) deficiency is an autosomal recessive disorder that shows large phenotypical variability, ranging from no symptoms to intellectual disability, motor retardation, and convulsions. In addition, homozygous and heterozygous mutation carriers can develop severe 5-fluorouracil (5-FU) toxicity. The lack of genotype-phenotype correlation and the possibility of other factors playing a role in the manifestation of the neurological abnormalities, make the management and education of asymptomatic DPD individuals more challenging. We describe a 3-month-old baby who was incidentally found by urine organic acid testing (done as part of positive newborn screen) to have very high level of thymine and uracil, consistent with DPD deficiency. Since the prevalence of asymptomatic DPD deficiency in the general population is fairly significant (1 in 10,000), we emphasize in this case study the importance of developing a guideline in genetic counseling and patient education for this condition as well as other incidental laboratory findings.
Reproduction in spirorbis (spirorbella) marioni Caullery & Mesnil (polychaeta: Serpulidae)

Abstract Reproductive activity in Spirorbis marioni Caullery & Mesnil living on the alga Earegia laevigata Setchell in offshore beds was monitored for thirteen months by collecting freshly beached wrack at La Jolla, California, in 1968–1969. There was production of eggs and brooded embryos throughout the year. An average of 82 % of adults larger than 1 mm greatest diameter were reproductively active at all times. A low but significant correlation was observed between seasonal sea surface temperature variation and seasonal fluctuations in breeding activity. Short term fluctuations in breeding activity were monitored with daily samples for seven months. There were periodic peaks in the spawning of eggs and release of larvae which coincided to a high degree with tidal extremes.
Synthesis and characterization of ester-based prodrugs of glucagon-like peptide 1

Peptides represent a rich natural source of potential medicines with one notable pharmaceutical limitation being their relatively short duration of action. A particularly good example of this phenomenon is glucagon-like peptide 1 (GLP), a hormone of appreciable interest for the treatment of type II diabetes. In the native form, GLP demonstrates an extremely short half-life in plasma and a relatively narrow therapeutic index with gastrointestinal adverse pharmacology. We envisioned a prodrug of GLP as a means to extend the duration of action and broaden the therapeutic index of this peptide hormone. We designed, synthesized, and characterized ester-based prodrugs of GLP that differentially convert to the parent drug under physiological conditions driven by their inherent chemical instability. In a set of dipeptide extended GLP-analogs we explored the rate of diketopiperazine (DKP) and diketomorpholine (DMP) formation, and the release of the active peptide. The rate of cleavage was observed to be a function of the conformation of the dipeptide promoiety and the strength of the cyclization nucleophile. Through the careful selection of chemical functionality, a set of GLP ester prodrugs of variable half-lives has been identified.
Calcification and proteoglycan accumulation following balloon angioplasty and stenting.

PURPOSE To examine in a porcine model if a correlation exists between calcification and the hyperplastic response of arteries to balloon angioplasty and stenting. METHODS Eleven Sinclair miniature swine on an atherogenic diet underwent balloon angioplasty or endovascular stenting in nondiseased external iliac arteries using standard procedures. Ninety days postoperatively, the animals were euthanized, and histological sections of the dilated, stented, and control arteries were examined for evidence of calcification and increased proteoglycan accumulation. RESULTS An increase in proteoglycan accumulation and the loss of integrity of the internal elastic lamina were observed in both the dilated and stented arteries. Diffuse calcification was seen in the media/neomedia of both groups, and large calcium salt deposits were observed in the dilated arteries at the site of the internal elastic lamina and near the stent struts in stented arteries. CONCLUSIONS Internal elastic lamina loss of integrity appears to be related to an increase in proteoglycans through the formation of a neointima, and the arterial hyperplastic response to balloon angioplasty and stenting seems to lead to calcification.
The synthesis and structure of some trimethylgermyl amides

Abstract A series of trimethylgermyl amides of the type (where R = H, Ch 3 ; R′ = H, aryl) were prepared and the amide structures established by IR and NMR measurements. The barriers to rotation and isomer rations were determined and are discussed in relation to those for the carbon and silicon homologs.
Natural Experiments Indicate That Geomagnetic Variations Cause Spatial and Temporal Variations in Coconut Palm Asymmetry

In plants with alternately arranged foliage, such as the coconut palm ( Cocos nucifera ), leaves are attached to the stem in either an ascending clockwise (left handed [L]) or counterclockwise (right handed [R]) spiral ([Fig. 1][1] ). Foliar spiral direction (FSD) is not genetically determined in
Negotiation-based routing between neighboring ISPs

We explore negotiation as the basis for cooperation between competing entities, for the specific case of routing between two neighboring ISPs. Interdomain routing is often driven by self-interest and based on a limited view of the internetwork, which hurts the stability and efficiency of routing. We present a negotiation framework in which adjacent ISPs share information using coarse preferences and jointly decide the paths for the traffic flows they exchange. Our framework enables pairs of ISPs to agree on routing paths based on their specific relationship, even if they have different optimization criteria. We use simulation with over sixty measured ISP topologies to evaluate our framework. We find that the quality of negotiated routing is close to that of globally optimal routing that uses complete, detailed information about both ISPs. We also find that ISPs have incentive to negotiate because both of them benefit compared to routing independently based on local information.