cssi/SciSciGPT-SciSciNet huggingface dataset:
Photometric scanning of centrifuged density gradient columns.

Abstract Results obtained with an apparatus for recording the ultraviolet absorbance at all depths in a centrifuged density gradient column and for collecting consecutive samples are presented. A heavy sucrose solution is forced from a motor-driven syringe into the bottom of a gradient column. The gradient column floats on the heavy sucrose solution and is slowly forced up through a plastic adapter shaped like an inverted funnel and through a cell 1 cm thick with silica windows. As the solution passes through the cell, the light absorption at 253.6 mμ is measured and automatically recorded on a chart as absorbance. Samples of effluent from the optical cell may be collected manually or with an automatic fraction collector. The areas under the virus peaks on the charts recording absorbance were reproducible with a standard error corresponding to 4.4 μg of virus and were directly proportional to the concentration of southern bean mosaic virus up to 0.6 mg. As little as 0.01 mg of tobacco mosaic virus could be detected.
BLADDER NECK RECONSTRUCTION IN CHILDREN

Bladder neck reconstruction in children is a challenging undertaking. Goals must be established for each patient, either continence or dryness. Knowledge of the various types of bladder neck reconstructive procedures and what they are designed to do is important when considering bladder neck reconstruction. A detailed description of urethral lengthening, reimplantation, and other bladder neck reconstructive procedures is presented.
The clinical trial imperative

As clinical judgment has joined forces with evidence-based medicine, nephrologists critically assess the validity of the data available to support therapeutic decisions for children with kidney disease. Unfortunately, a paucity of data often prevents the practice of evidence-based medicine. Three scenarios illustrating the status of evidence and clinical decision making are provided. A review of the pediatric nephrology literature supports a call for general support of ongoing clinical trials and encourages the creation of additional feasible clinical trials to improve the practice of medicine.
In vitro activity of LY146032 (daptomycin), a new peptolide.

The in vitro activity of LY146032, a new peptolide antibiotic, was compared with those of vancomycin, teicoplanin, imipenem, amoxicillin and erythromycin. LY146032 inhibited 90% ofStaphylococcus aureus andStaphylococcus epidermidis, including methicillin-resistant isolates at ⩽ 1μg/ml. Its activity was comparableto those of vancomycin and teicoplanin. MIC90s for the beta-hemolytic streptococci varied from 0.25 μg/ml for group B streptococci to 4μg/ml for some group C and F streptococci. MICs forStreptococcus faecaliswere in the range of 0.5 to 8μg/ml,and the MIC90 4μg/ml,compared to 4μg/ml for vancomycin and 1μg/ml for teicoplanin. For some viridans streptococci the MICs were 4μg/ml, whereasStreptococcus pneumoniae were inhibited by 0. 5μg/ml.Corynebacterium JK species were inhibited by 0. 5μg/ml, similar to vancomycin, andListeria monocytogenes by 4μg/ml.Neisseria species,Haemophilus species and enteric species were not inhibited. Most MBCs were within two-fold of the respective MICs. After 14 days passage in subinhibitory concentrations of LY146032,Staphylococcus aureus, Staphylococcus epidermidis andStreptococcus faecalis showed minimal increase in MICs. The activity of LY 146032 was increased by adding Ca2+ and was reduced in an anaerobic environment. Overall, LY146032 is an extremely interesting new agent that inhibits gram-positive species.
The long-term bioeconomic impacts of grazing on plant succession in a rangeland ecosystem

Abstract The on-site environmental impacts of for-profit livestock grazing on private rangeland are conceptualized as an interdependent pair of interrelated-species models defined over different time scales. Slow-manifold theory links the fast (annual) dynamics of an optimization-based grazing-decision submodel (formulating the predator-prey relationship between livestock and vegetation), with the slow (decade) dynamics of a species-competition submodel (specifying grazing-induced succession from perennial grasses to less environmentally-desirable annual species). A stable manifold (partitioning phase space into basins-of-attraction to equilibria representing plant states of differing social desirability) is analytically approximated, and the approximation is analyzed for its mathematical accuracy under various bioeconomic conditions. The approximated stable manifold represents a ‘successional threshold’ measuring the resilience of the rangeland ecosystem in recovering from historic overgrazing. The successional threshold provides a means of evaluating the environmental efficacy of agricultural programs which would promote recovery of private rangeland by offering financial incentives to induce for-profit livestock enterprises to reduce grazing
EVIDENCE-BASED 3D OBJECT RECOGNITION.

An evidence-based recognition technique is defined which identifies 3D objects by looking for notable features of objects. 3D surface patch information is used to derive a representation of objects from their range images. A list of salient or evidence features with corresponding degrees of evidence of the various objects in the database forms the core of an object recognition system. Occurrences of these salient features are interpreted as evidence for or against the hypothesis that a given object occurs in the scene. A measure of similarity between the set of observed features and the set of salient features for a given object in the database is used to determine the identity of an object in the scene or reject the object(s) in the scene as unknown. This procedure has polynomial time complexity and correctly identifies a variety of objects in both synthetic and real range images.
A characterization of a universally optimal design within a class of block designs

Abstract It is shown that within the class of connected binary designs with arbitrary block sizes and arbitrary replications only a symmetic balanced incomplete block design produces a completely symmetric information matrix for the treatment effects whenever the number of blocks is equal to the number of treatments and the number of experimental units is an integer multiple of the number of treatments. Such a design is known to be universally optimal.
The effect of immersion disinfection of elastomeric impressions on the surface detail reproduction of improved gypsum casts

Abstract This investigation examined improved gypsum casts for surface roughness and line-detail reproduction after the immersion disinfection of elastomeric impression materials in an acid glutaraldehyde, an alkaline glutaraldehyde, and a phenol. Impressions were made of a surface roughness standard (R a = 3.08 μm) that was custom made to include engraved grooves following American Dental Association specification No. 19. Mean surface roughness (R a ) values for all casts of all combinations of disinfectant treatments, impression materials, and improved gypsum stones were obtained with a surface analyzer. Untreated impressions served as controls. Data examined by an analysis of variance indicated that the addition silicone and polyether impression materials provided a surface roughness similar to the precision displacement specimen standard. The acid glutaraldehyde disinfectant demonstrated enhanced line-detail reproduction compared with the standard. Addition silicone and polyether impression materials combined with the acid glutaraldehyde provided the model system closest to the mean surface roughness of the reference standard. These combinations revealed differences in the surface roughness reproduction among the represented improved dental stones.
NATURE OF THE PLANT COMMUNITY. VI. TEXAS GRASSLAND COMMUNITIES UNDER TRANSPLANTED CONDITIONS

the latest-flowering clones from the coast of southern Texas. Clones of Stipa leucotricha Trin. and Rupr. from a broad area in Texas lacked a flowering gradient. Grassland communities of western Texas and the Panhandle, attuned to short growing seasons and low rainfall, were composed of opportunists, the Bouteloua species, and early-flowering variants within the widespread species. Communities of central Texas in habitats of highly unpredictable moisture pattern and a relatively long growing season contained later-flowering variants. Coastal communities attuned to a long growing season contained the latest-flowering variants.
Spin separation in a metal overlayer.

The electronic properties of a ferromagnetic Fe monolayer epitaxially adsorbed on a Ag{100} substrate have been computed fully self-consistently. The minority $d$-band spin states of the Fe overlayer were found to be separated energetically from the majority-spin band. The magnetic moment per overlayer atom is 3.0${\mathrm{\ensuremath{\mu}}}_{\mathrm{B}}$, 36% larger than that of bulk iron.
Lagrange's equation for continua

Lagrange’s equation provides the cornerstone for the generalized methods of classical mechanics [l-5]. Despite the unnecessary assumptions of many existing derivations, the excess of specialized terminology regarding kinematic constraints, and the questionable procedure of regarding a rigid body as an “infinite number” of particles, there may appear to be little point to yet another derivation of Lagrange’s equation. However, this view proves erroneous when we consider the dynamics of nonrigid continua. At present there simply does not exist a Lagrangian formulation which applies to nonrigid continua, ignoring certain physically and mathematically questionable extended versions of what is known as Hamilton’s principle [5-71. Thus, the dynamic equations for a given nonrigid continuum are commonly obtained by considering a small element, applying Newton’s law for a particle, and taking limits as the size of the element approaches zero. This elemental procedure generally requires very strong assumptions regarding spatial continuity and differentiability of the velocity and displacement functions, and often there is no apparent physical reason why these assumptions should hold. In deriving the one-dimensional wave equation for the simple string by using the elemental method, we assume the existence of two spatial derivatives of the deflection curve. However, we violate this assumption immediately upon considering a triangular initial deflection curve. Even if we consider only twice-differentiable initial deflection curves, we may still have difficulties. In the multidimensional wave equation, for example, twice-differentiable intial data do not necessarily produce a twice-differentiable solution due to focusing effects [&lo]. A great deal of study has been devoted to a generalized version of the multidimensional wave equation [9, lo]. The generalized solution obtained does not have the strong continuity and differentiability required of the classical solution and, when restricted to an appropriate Sobolev space,
Effect of Single-Bit Digitization in Adaptive Array Control Loops

The properties of an adaptive array antenna, including transient response rate and control loop noise, depend on the intensity of the external noise field. The dependence can be reduced by 1-bit digitization of the real and imaginary parts of the signals from which the envelopes in the control loops are formed. This can be done without degrading the performance of the adaptive array.
Defect formation in hafnium dioxide thin films

Hafnium dioxide thin films were deposited by reactive electron-beam evaporation at six different substrate temperatures on fused-silica substrates. During the depositions, the scattering of light caused by the growth of defects in the films was recorded with in situ total internal reflection microscopy. After deposition the films were analyzed by angle-resolved scatterometery, spectrophotometric measurement of film reflectance and transmittance, atomic force microscopy, and x-ray diffraction. We explore the effects of film defect formation on film optical properties and film surface topography using these data.
Posterior neocortical systems subserving awareness and neglect. Neglect associated with superior temporal sulcus but not area 7 lesions.

Objective: In humans and monkeys, the intraparietal sulcus separates the superior parietal lobule from the inferior parietal lobule (IPL). Whereas in humans Brodmann's area 7 is above this sulcus, in monkeys it is below and therefore part of the IPL. In humans, the IPL consists of Brodmann's areas 39 and 40. Some investigators contend that the monkey homologue of the human IPL (areas 39 and 40) is the monkey's IPL (area 7). Others contend that it is, at least in part, in the monkey's superior temporal sulcus (STS). In humans, IPL lesions induce neglect. Although IPL lesions in monkeys also have been reported to induce neglect, the STS was involved in these lesions. We sought to learn which of these two areas, when ablated, produces neglect. Design: Study of five adult stump-tailed macaque monkeys by making five isolated STS and six IPL lesions. Results: Inferior parietal lobule lesions were associated with misreaching but not with unilateral neglect. Neglect was observed in association with five of the six STS lesions. Conclusions: With regard to neglect, STS may be the monkey homologue of the human IPL. Animals with STS lesions and humans with IPL lesions may manifest unilateral neglect because these areas are necessary for normal awareness of external stimuli. This awareness may result from the integration of the areas important in stimulus localization (the "where is it?" system) and stimulus identification (the "what is it?" system), as well as the areas important in defining the biologic importance of stimuli, such as the frontal lobes and limbic areas.
Time-frequency characteristics of electromagnetic interference in 500kv switch operation

Discussed the electromagnetic interference of secondary system in operating the isolating switch of various 500kV AC systems. Summarized the time-frequency characteristics of the interference by analysis the time doming and frequency doming characteristics of them.
Evolution of the Continental Shelf and Slope: ABSTRACT

Further explanations of the origin of the continental slope, such as ascribing it to catastrophism, normal faulting, a wave-built terrace, or marginal downwarping, appear to be unsatisfactory. Instead, the writer considers continental slopes to have been constructed by the folding of the continental rise against the continental block, forming a eugeosynclinal orogen. Accordingly, continental slopes would be the flanks of such orogens; a secondary cause for some continental slopes may be the modified scarp left after a rifting-apart of a continental mass by continental drifting. Once formed, initial continental slopes undergo modification by erosion and sedimentation. A proposed mode for such geomorphic evolution is presented. Continental shelf formation is a part of this volution. End_of_Article - Last_Page 355------------
A minimal Cantor set in the space of 3-generated groups

We construct and study a family of 3-generated groups \(\mathcal{D}_w\) parametrized by infinite binary sequences w. We show that two groups of the family are isomorphic if and only if the sequences are cofinal and that two groups cannot be distinguished by finite sets of relations. We show a connection of the family with 2-dimensional holomorphic dynamics.
Characterization of an extracellular azo dye-oxidizing peroxidase from Flavobacterium sp. ATCC 39723

Abstract A peroxidase from Flavobacterium sp. ATCC 39723 was selected from nine peroxidase-producing bacterial strains for its highest azo dye-oxidizing capacity among the peroxidases examined. Comparison of azo dye No. 1 (3,5-dimethyl-4-hydroxyazobenzene-4′-sulfonic acid) oxidation with native and heat-inactivated enzyme preparations, and with and without H2O2, confirmed the involvement of this peroxidatic enzyme in azo dye decolorization. The peroxidase activity in this gram-negative Flavobacterium sp. was predominantly extracellular. The enzyme was actively expressed in a minimal medium with sodium glutamate as sole carbon source. The addition of either pentachlorophenol or azo dye No. I into culture media did not enhance enzyme production. The Flavobacterium peroxidase was concentrated by ultrafiltration and partially purified by Q-Sepharose column chromatography. The optimal conditions for azo dye oxidation by the Flavobacterium peroxidase were pH 7–8, and 5 mM H2O2 concentration, when the azo dye concentration was held constant at 50 μM. Cobalt chloride, mercury chloride, and manganese sulfate had significant inhibitory effects on dye oxidation by the peroxidase. Although guaiacol was a strong inhibitor of dye oxidation by this enzyme, veratryl alcohol was not, even at I mM concentration. A heme protein inhibitor, potassium cyanide, showed considerable inhibition. The substrate specificity of the peroxidase toward 22 azo dyes was also examined. Specificity was compared to that of another peroxidase from the Streptomyces sp. YCED 105. The presence of syringyl or guaiacyl groups in the dye structures resulted in enhanced oxidation by both peroxidases. These data showed that azo dyes can be made more readily oxidizable by bacterial peroxidases by appropriately modifying the substitution pattern of their aromatic rings.
Metric of Yang-Mills orbit space on the lattice

We find coordinates, the metric tensor, the inverse metric tensor and the Laplace-Beltrami operator for the orbit space of Hamiltonian SU(2) gauge theory on a finite, rectangular lattice. This is done using a complete axial gauge fixing. The Gribov problem can be completely solved, with no remaining gauge ambiguities.
Value of somatostatin receptor scintigraphy: A prospective study in gastrinoma of its effect on clinical management

Abstract BACKGROUND & AIMS: Recently [111In-DTPA-D-Phe1]-octreotide was approved for somatostatin receptor scintigraphy (SRS) of gastroenteropancreatic tumors. SRS and other tumor localization methods can be time consuming, expensive, and involve patient inconvenience. The role of SRS in comparison to other tumor localization modalities remains undefined because the relative effects of these methods on management have not been studied. The aim of this study was to determine whether SRS alters clinical management in Zollinger-Ellison syndrome. METHODS: One hundred twenty-two consecutive patients were studied prospectively. Each patient was assigned to one of five different clinical categories. Conventional imaging studies (ultrasonography, computerized tomography, magnetic resonance image, angiography, and bone scan) were performed, and the management was proposed. SRS was then performed. Clinical management was reassessed, and whether SRS altered management was determined based on six criteria. RESULTS: SRS was superior to any single imaging study. SRS altered management in 47% overall and in 22%- 60% of patients in the five different clinical categories. Primary tumor localization and clarification of equivocal localization results from conventional studies were the principal reasons for altering management. SRS was equally useful in patients with or without metastatic liver disease. CONCLUSIONS: Because of the ability of SRS to alter clinical management combined with its superior sensitivity, high specificity, simplicity, and cost-effectiveness, SRS should be the initial imaging modality for patients with gastrinomas. (Gastroenterology 1997 Feb;112(2):335-47)
Ratched Filter Restoration Of Coded-Gamma And X-Ray Imagery

Recent work has stimulated considerable interest in using radar pulse compression concepts to improve the quality of medical X-ray and gamma ray photographs. (Refs. 1 and 2) These techniques involve using a coded point spread function to obtain increased resolution and reduced ex posure time. The coded point spread function allows use of a larger aperture in the X-ray camera, but requires a post-detection processing step in order to decode the data and obtain the desired image. The point spread function must be coded in such a anner that its two-dimensional autocorrelation function is very sharply peaked. In the post-detection pro cessing; the coded data are cross-correlated with the chosen point spread function to obtain the desired image.
The effect of service loading on shell growth in rails

Abstract A study is made of the relatively benign shelling fractures observed in the railhead. In particular, the tendency of these horizontal fractures to turn into a vertical detail fracture during fatigue crack propagation is considered. A two-dimensional linear elastic fracture mechanics model is combined with a proposed fatigue crack path stability model to study the effects of the complex stress state in the rail on this crack turning process. The results indicate that the leading edge of the shell will tend to turn down into the rail while the trailing edge will propagate to the surface for a short shell. However, once the shell reaches some calculated length, both ends will tend to grow to the surface. The most significant finding is that if the shell grows through the length of instability, it will grow in a stable in-plane manner. Finally, the analysis is compared to field observations.
Differential Evolution of the Osteopathic and Chiropractic Professions in the United States

Andrew Abbott in The System of Professions: An Essay on the Division of Expert Labor, one of the best books on the sociology of the professions ever written, presents systemic theory and data regarding the origin, growth, fusion, and fission of professions as they compete with each other over what he calls "workplace jurisdictions" [I]. Defining "professional power" as "the ability to retain jurisdiction when system forces imply that a profession ought to have lost it," he argues that "jurisdictional invasion generally begins in the workplace, then moves to the public mind, and then into the law." And he generalizes how long it usually takes for the system to equilibrate after a jurisdictional challenge: "Jurisdictions are renegotiated in workplaces over twoto threeyear periods, in (the public's mind) over tento twenty-year periods, in the law over twentyto fifty-year periods." That fits almost precisely osteopathy and chiropractic, both of which invaded the medical marketplace at the end of the last century, osteopathy coming first. Its founder Andrew Taylor Still was a frontier doctor who, having lost three children to an 1864 meningitis epidemic, "flung to the breeze the banner of osteopathy" in the 1870s and established the first osteopathic school in Kirksville, Missouri, in 1892 [2]. Chiropractic was "discovered" by Daniel David Palmer in 1895 at Davenport, Iowa, less than 150 miles from Kirksville, although he began using the word "chiropractic" only in the following year [3]. He began teaching it in 1898 but did not change the name of his school from "Palmer's School of Magnetic Cure" to "Palmer Infirmary and Chiropractic Institute" until 1902 [4]. Both Still and Palmer had earlier practiced magnetic healing, and Still had even advertised himself as a "lightning bonesetter" [5].
TANF Recipients' Barriers to Employability: Substance Abuse and Domestic Violence

Recipients of temporary assistance for needy families (TANF) encounter a variety of expectations and sanctions. Recipients face work requirements, limited resources, and barriers to employability, including the barrier of substance use. This article addresses the sanctions that are applied to clients who do not meet expectations of the policy, barriers to employability, disparities in resources, and factors influencing referrals for substance abuse treatment for TANF clients.
Electron impact ionization of metastable rare gases: He, Ne and Ar

Abstract Cross sections for ionization of atoms by electron impact are important quantities for modeling of low temperature plasmas and gas discharges. Although experimental and theoretical studies of ionization of atoms from their ground levels have been extensive, much less information is available about the larger cross sections for ionization from excited levels. We use the Binary–Encounter–Bethe (BEB) method of Kim and Rudd to calculate ionization cross sections from the 1s2s 3S level of He, the 2p53s 3P levels of Ne, and the 3p54s 3P levels of Ar. We compare our results with the few available experimental results and with results from other theoretical methods.
Gravity inversion of an interface above which the density contrast varies exponentially with depth

Mapping of an interface above which the density contrast varies exponentially with depth, as is common at the basement surface of sedimentary basins, is efficiently achieved by a theoretically precise gravity method which can be applied to either profile data or twodimensional data. The contrast in mass above the interface is modeled by an array of vertical rectangular prisms with density contrasts varying exponentially with depth. Gravity anomalies due to the prisms are calculated in the wavenumber domain and then converted to the space domain. The precision of the inverse numerical Fourier transform in this procedure is significantly increased by a shift‐sampling technique based on the discrete Fourier deviation equation. Depth to the interface is determined by iterative adjustment of the vertical extent of the prisms in accordance with observed gravity anomaly data. The basement surface of the Los Angeles basin, California, calculated by this method, closely duplicates the published configuration based...
Interpersonal Discrimination and the Health of Illicit Drug Users

Although discrimination has been shown to adversely affect the health of marginalized populations, there is a paucity of research on the health impacts of discrimination experienced by illicit drug users. The purpose of this study was to examine the association between interpersonal discrimination and the mental and physical health of illicit drug users taking into account several potential confounding factors. A sample of 1,008 active illicit substance users (defined as having used cocaine, crack, or heroin in the previous 2 months) were recruited in three New York City neighborhoods between August 2000 and January 2001 using street-outreach techniques. Discrimination due to illicit drug use was the most common form of interpersonal discrimination experienced and more than one-half the study participants reported experiencing discrimination due to more than one attribute. Discrimination was significantly associated with poor mental health (measured by the SF-36 mental health score), depression (measured by the CES-D), and the number of self-reported chronic physical health conditions. The presence of multiple stigmatizing characteristics was associated with poorer mental and physical health. Discrimination may contribute to poor mental and physical health in this marginalized population, potentially complicating the provision of substance abuse treatment.
Thermal analysis and modeling of a notebook computer battery

Abstract Thermal performance of an intelligent notebook computer battery-pack (IBA2+™, Hewlett Packard) was evaluated during operation at 42 °C using a combination of thermal analysis and modeling. The battery-pack was charged at 2.36 A and provided 55-W constant power during discharge. Results showed the battery-pack has reasonable heat dissipation capability except that the temperature rise of its charge control IC increases to 67 °C, which is near the critical thermal limit of the device (73–75 °C). Autopsy results showed this IC has a small die to die-pad size ratio and also large volume of mold compound causing the device self-heating during the charge control process. Thermal modeling provided a detailed understanding of the thermal response of the battery under various operating conditions that helped to reduce the product design cycle-time. The overall results indicated that the battery temperature rise during charge is dominated by the power dissipation from the control electronics and during discharge by the heat dissipation from Li-ion cells.
Simulation of premixed turbulent flames

Premixed turbulent flames are of increasing practical importance and remain a significant research challenge in the combustion community. In this paper we discuss a numerical methodology we have developed that combines a low-Mach number formulation combined with adaptive mesh refinement to exploit the variation of scales associated with premixed flame simulations. This combined approach, when implemented on parallel computing hardware, improves computational efficiency by several orders of magnitude.
Diagenesis of Oolites in Lodgepole Formation (Mississippian), Central Montana: ABSTRACT

Several cross-stratified ooid and bioclastic grainstone layers are present in the upper part of the cyclically deposited Mississippian Lodgepole Formation in central End_Page 630------------------------------ Montana. Two of those exposed in the Big Snowy Mountains were selected for a detailed study of diagenesis in ancient carbonate sandstones. Evidence suggests that these sediments were deposited in a shallow marine-shelf environment. Diagenesis of the carbonate sands began with cementation in the intertidal or submarine environment. Partial cementation was followed by partial silicification of bioclastic debris and ooids. No definite order could be determined for later diagenetic events; they may have proceeded more or less simultaneously. Dolomitization appears to have postdated silicification and shows preferential replacement of ooid coatings and mud. The sandstones are compacted and stylolitized, and pressure solution may have served as a source for the coarse, blocky calcite which fills the remaining pore space. The distinctive red color of the upper grainstone layer may be due to recent weathering. End_of_Article - Last_Page 631------------
AN ALTERNATIVE MODEL FOR OPTIMISING PAYLOADS OF BUILDING GLASS

ENGLISH ABSTRACT: This article deals with the development of a multi-stage model for optimising payload placement on a hauler-trailer rig in an environment described by physical and regulatory constraints. The model which purports to be an improvement on an earlier model provides two types of solution i.e. a feasible solution which satisfies all zone loading and axle weight constraints, or an infeasible solution giving the cause and quantification of source(s) of infeasibility which may be used to modify model inputs for further attempts at optimisation. AFRIKAANSE OPSOMMING: Die artikel handel oor die ontwikkeling van 'n multistadiummodel vir die optimisering van vragplasing op 'n sleepwa onder fisiese en regsvoorskriftelike voorwaardes. Die model wat daarop aanspraak maak dat dit 'n verbetering is op 'n vorige model, lewer as uitset twee oplossingstipes naamlik 'n gangbare oplossing wat alle sone- en aslasrandvoorwaardes eerbiedig, of 'n ongangbare oplossing wat oorsaak en kwantifisering van ongangbaarheidsbronne uitwys vir die gebruik van gewysigde modelinsette by verdere pogings tot optimisering.
Topographic studies of microsomal and pure prostaglandin H synthase.

Abstract Prostaglandin H synthase catalyzes the first step in the conversion of polyunsaturated fatty acids to prostaglandins, thromboxanes, and prostacyclins. The enzyme is normally bound to the endoplasmic reticulum membrane, but can be purified to homogeneity after solubilization with detergent. The topologies of the microsomal and the pure detergent-solubilized forms of the synthase were compared by an examination of their sensitivity to degradation by proteases, of the effect of heme on this protease sensitivity, and of the sizes of proteolytic fragments produced. For the microsomal synthase, the localization of proteolytic fragments was also determined. Analysis of the microsomal proteins after proteolytic digests involved separation by polyacrylamide gel electrophoresis and selective detection of the synthase-derived polypeptides with a polyclonal antibody against the pure synthase. With both the microsomal and the pure synthase, incubation with trypsin led to a progressive loss of cyclooxygenase activity and cleavage of the synthase subunit (70K Da) into two fragments of 38K and 33K Da. Incubation of the detergent-solubilized form of the synthase with proteinase K and chymotrypsin also produced a very similar pair of fragments (38K and 33K Da). After incubation of the microsomes with trypsin both the 38K and 33K Da fragments from the synthase remained bound to the membrane; no cyclooxygenase activity was released in soluble form from the microsomes by trypsin. Further, neither trypsin nor proteinase K released soluble radiolabeled peptides from microsomes whose synthase had been labeled with [ acetyl - 14 C]-aspirin. With the microsomal synthase the sensitivity to protease (66% of the cyclooxygenase activity was lost after 90 min incubation with proteinase K) was enhanced by depletion of heme (84% of activity lost) and was decreased by addition of heme (only 20% of activity lost), just as had been previously demonstrated for the detergent-solubilized synthase. At each of several intervals during an incubation of the pure synthase with trypsin the extent of cleavage of the synthase polypeptide correlated reasonably well with the extent of loss of cyclooxygenase activity; a similar relation between proteolytic cleavage and loss of activity was observed in digests of the pure synthase supplemented with differing amounts of heme. These results suggest that the microsomal and the pure soluble forms of the synthase share a single exposed protease-sensitive region, and that proteolytic cleavage in this region results in loss of cyclooxygenase activity; binding of the heme prosthetic group changes the structure of this region so as to reduce protease sensitivity and thus preserve cyclooxygenase activity. The rest of the polypeptide chain in the microsomal synthase is arranged so as to maintain a tight association with the endoplasmic reticulum membrane even after cleavage occurs in the protease-sensitive region.
Pressure broadening of the J = 1 ← 0 transition of carbon monoxide

Abstract The pressure broadening of the carbon monoxide line near 115 GHz was measured at liquid nitrogen, dry ice, and room temperature, with typical experimental uncertainties of about 10%. Broadening gases were carbon monoxide, hydrogen, deuterium, helium, neon, and argon. No significant lineshifts were observed.
Semi-inverse methods for obtaining partial differential equations with chaotic solutions

Abstract Semi-inverse methods are used to construct partial differential equations that have chaotic solutions. For first order P.D.E., this comes about by the natural association of the P.D.E. with the orbital equations for the characteristics. Explicit examples are given of linear, quasilinear, nonlinear and systems with the same principal part. The latter kind are used to show that there are 2-dimensional, steady, incompressible, inviscid fluid flows that exhibit chaotic behavior. Second order P.D.E. Are obtained through the requirement that they admit similarity solutions that satisfy O.D.E. With known chaotic behavior. Explicit systems of nonlinear second order P.D.E. That admit chaotic simple wave similarity solutions are constructed.
Sample Introduction Using a Tungsten Probe for Reducing Interferences in the Determination of Manganese in Clinical Samples by Atomic Absorption Spectrometry

Abstract The use of a tungsten probe for the introduction of clinical samples for determination of manganese by atomic absorption spectrometry is shown to reduce interferences associated with the complex matrix. This is due to atomization under more isothermal conditions. The system was used to determine manganese in blood and urine with a good correlation between direct and standard addition methods achieved. Accuracy was assessed by comparison with NBS standard urine and found t o be excellent.
Base-Catalyzed Hydrolysis of Flavins: Effect of Amines and the Particular Role of Position 3

The base-catalyzed hydrolysis of flavins was investigated in 50 percent water-methanol with excess sodium hydroxide or excess amines at different temperatures. Rate constants for the pseudo first-order cleavage of the pyrimidine portion of the isoalloxazine systems were measured and with sodium hydroxide shown to increase from lumiflavin to 3-ethyllumiflavin to 3-carboxyamido(phenylalanyl)lumiflavin. With amines, the size as well as basicity is of prime importance since the general order in efficacy of the nucleophile for hydrolysis of flavins is ethylamine > diethylamine > triethylamine > benzylamine > tributylamine. In general, alkylation of the 3-imino function of the flavin increases its lability because of inability to ionize and undergo resonance stabilization of the anionic tautomers. Moreover, the special case where a 3-carboxyamido function is present allows intramolecular polarization, via hydrogen bonding of the amide hydrogen to 4-carbonyl oxygen, which causes a marked increase in hydrolysis rate in sodium hydroxide. From the temperature dependencies of the rates of hydrolysis, the calculated values for energies of activation indicate the decrease expected upon 3-alkylation and further upon intramolecular enhancement with the 3-carboxyamido group. The calculated values for entropies of activation are large and negative in accord with considerable loss of degrees of freedom in the activated complexes formed in the bimolecular mechanism.
Inhibition of ornithine carbamyl transferase and the pyrimidine precursor role of L-α-aminobutyrate and propionate ni neurospora

Abstract 1. 1. L -α-Aminobutyrate and propionate are postulated to function as pyrimidine precursors in Neurospora crassa strain 1298 by inhibition of ornithine carbamyl transferase (EC 2.1.3.3) and by conversion to aspartic acid. 2. 2. L -α-Aminobutyrate and two other inhibitors. L -α,γ-diaminobutyric acid and L -norvaline, function by competition with L -ornithine. L -Norvaline also supports growth of Strain 1298. 3. 3. The α-aminobutyrate:ornithine ratio necessary for 50% inhibition is exceeded in the acid-soluble fraction of the mutant grown on L -α-aminobutyrate. 4. 4. Levels of carbamate kinase (EC 2.7.2.2) in Strain 1298 are increased in the presence of L -α-aminobutyrate, apparently by derepression. 5. 5. Propionate is a less effective inhibitor of ornithine carbamyl transferase than L -α-aminobutyrate, but the 230-fold purified enzyme is 6 times more sensitive to propionate than the crude enzyme. 6. 6. The radiocarbon of L -α[3- 14 C]aminobutyrate is preferentially utilized for aspartate and glutamate of the acid-soluble pool of Strain 1298.
Leading Academic Departments of Psychiatry

Thus it is that in war the victorious strategist Only seeks battle after the victory has been won, Whereas he who is destined to defeat first fights And afterward looks for victory (1).
STEADY-STATE FLUORESCENCE OF POLYSTYRENE PLASTICIZED BY SUPERCRITICAL CARBON DIOXIDE

A steady-state fluorescence study of low-molecular-weight polystyrene (MW = 1060 g/mol and 13,000 g/mol) plasticized in supercritical CO2 is reported. In addition to excitation wavelength, molecular weight, and polystyrene concentration dependencies, CO2 density also strongly affects the emission spectral contours. A major increase in the steady-state fluorescence intensity and a significant decrease in the polystyrene 320- to 365-nm fluorescence intensity ratio are observed when CO2 density is increased. Concentration and conformational changes in the polystyrene molecules are used to explain the observations, and these results are proposed to arise from changes in the plasticization power of supercritical CO2 over the density range studied. A theoretical model is proposed that is based on the assumption that, at low CO2 densities and low polymer concentrations, polystyrene intermolecular interactions are negligible. The proposed model is able to fit our observed fluorescence data from a CO2 reduced density of 0.3 to 1.4.
Finite Element Analysis of Woven Airbeams

The underlying mechanics of airbeam structures continues to be a topic of current research. Airbeams are attractive because they have the advantage of outstanding strength-to-weight ratios, can deform without causing irreversible damage to the structure, and the deflated storage space is small. Major challenges in the analysis of airbeams include capturing fabric wrinkling under small compressive strains and incorporating the effects of internal pressure. This paper presents results from analyses of cylindrical woven airbeams using the commercial finite element software package ABAQUS. Models are created using a combination of shell and membrane elements, and loaded in three point bending. The models are solved as quasi-static using the ABAQUS/Explicit solver. The effects of mesh density and material damping on solution accuracy are investigated. Results of the finite element models are compared to experimental data.Copyright © 2006 by ASME
Importance of confined longitudinal optical phonons in intersubband and backward scattering in rectangular AlGaAs/GaAs quantum wires

The important role of confined longitudinal optical (LO) and surface optical (SO) phonons is investigated for different types of individual scattering processes in AlGaAs/GaAs quantum wires. Electron wave function tailing due to finite barrier height has been properly taken into account. We demonstrate that for highly confined wires structures Ly=Lz=40 A, forward and backward scattering are dominated by SO phonons. For 80 A×80 A structures, forward scattering is still predominately by SO phonons while backward scattering is dominated by confined LO phonons. Finally, for 150 A×150 A, confined phonons control both forward and backward scattering. However, we demonstrate that confined LO phonons play a dominant role in intersubband transitions even in highly confined structures, and that it has the most significant effect on the backward scattering in quantum wires of Ly=Lz≳80 A.
Optimizing bone health and minimizing skeletal morbidity in men with prostate cancer

Maintaining bone health is important in the management of men with prostate cancer. Patients receiving androgen deprivation therapy are at increased risk for treatment-related osteoporosis, and patients with bone metastases are at increased risk for skeletal morbidity related to debilitating skeletal-related events (SREs). Optimizing bone health in these patients includes lifestyle modifications, calcium/vitamin D supplementation, and osteoclast-targeted agents in select high-risk patients. No agent is approved for the prevention of bone metastases. Novel systemic agents have shown a beneficial effect bone by directly affecting tumor growth. Integration of these anticancer agents with osteoclast-targeted agents warrants further investigation.
Comparative Ultrastructure of Pectoralis Fibers from Electrically Stimulated and Muscle-Tensioned Broiler Carcasses

Abstract Transmission electron microscopy was used to study the ultrastructural changes induced by high voltage post-mortem electrical stimulation (ES) (440 V, 1 A, 5 pulses of 2 s on and 1 s off) and muscle tensioning (MT) (during chilling) in broiler chicken Pectoralis harvested at 1 h post-mortem. Control fibers lacked I-bands and H-zones. Electrical stimulation reduced sarcomere shortening and inhibited Z-line dissolution. Muscle tensioning pulled M-lines apart and allowed the disappearance of Z-line protein during aging. Combining ES and MT inhibited Z-line dissolution and caused wrinkling associated with passive contraction. All ES + MT fields had intact M-lines. The results suggested that there were similarities and differences in the ultrastructural effects of ES in broiler Pectoralis and red meat muscles.
Task aware information access for diagnosis of manufacturing problems

Pinpoint is a promising first step towards using a rich model of task context in proactive and dynamic IR systems. Pinpoint allows a user to navigate decision tree representations of problem spaces, built by domain experts, while dynamically entering annotations specific to their problem. The system then automatically generates queries to information repositories based on both the user's annotations and location in the problem space, producing results that are both task focused and problem specific. Initial feedback from users and domain experts has been positive.
Why Lessons Learned From the Past Require Haertel's Expanded Scope for Test Validation

In his article, Haertel (this issue) asks a fundamental question about how use of a test is expected to cause improvements in the educational system and in learning. He also considers how test vali...
Lymphoid populations of gut mucosa in chickens

Alterations of the lymphoid populations within the gut mucosa are commonly associated with humoral immunodeficiency diseases in man. Chickens provide a unique animal model for the study of abnormalities occurring in humoral immune deficiency states since agammaglobulinemia and selective immunoglobulin deficiencies can be induced in this species. Two populations of mucosal lymphoid cells were obtained from the small intestine of chickens, using a mechanical separation technique. One population was derived from within the epithelium (intraepithelial lymphocytes), the second from within the lamina propria. Intraepithelial and lamina propria lymphocytes did not proliferate in the presence of T or B mitogens as opposed to spleen; lamina propria contained more surface Ig-bearing cells than spleen and intraepithelial lymphocytes, and using a reverse hemolytic plaque assay, lamina propria but not the intraepithelial lymphocyte population was found to be rich in immunoglobulin-secreting cells relative to spleen. These preliminary studies demonstrated that gut mucosal lymphocytes can be obtained from chickens, and the study of these populations may provide insight into the pathophysiology of human gastrointestinal diseases.
A night at the operon

The Iac Operon: A Short History of a Genetic Paradigm by Benno Muller-Hill Walter de Gruyter:1996. Pp. 207. $35.95, DM54
Echocardiographic features of congenital mitral stenosis

Abstract To determine the echocardiographic features of congenital mitral stenosis, echoeardiograms were obtained in 2 children with Isolated mitral stenosis and 28 with mitral stenosis in assoclation with other congenital heart defects. The diagnosis was confirmed at cardiac catheterization in all 30 patients and also at operation or autopsy in 12. The pattern of mitral valve motion was assessed qualitatively, and the amplitude of excursion of the anterior leaflet and the rate of early diastolic closure (E-F slope) were measured. The values were compared with those from 145 normal children, 22 children with Isolated ventricular septal defect and 16 children with Isolated coarctation of the aorta. In patients with congenital mitral stenosis, the echocardtographic findings included dlastollc anterior motion of the posterior leaflet of the mitral valve, absence of the A wave and reduction of the E-F slope. Diastollc vibration of the mitral leaflets occurred in 21 of the 30 patients with mitral stenosis and in 8 of the 145 normal children, but in none of the patients with coartation of the aorta. From the mitral valve echogram, It was not possible to determine whether the site of the inflow obstruction was the leaflets themselves, the chordae tendbleae, the papillary muscles or a supravalve membrane. Patients with severe stenosis tended to have a greater decrease in E-F slope and exhibited abnormal motion of the posterior mitral leaflet more frequently than patients with mild or only moderately severe mitral stenosis. However, the mitral valve echogram was more useful in detecting the presence of mitral stenosis, even in the presence of other cardiac malformations, than in determining the precise anatomy of the mitral valve lesion or estimating Its severity.