cssi/SciSciGPT-SciSciNet huggingface dataset:
In Vivo Formation of Allosteric Aspartate Transcarbamoylase Containing Circularly Permuted Catalytic Polypeptide Chains: Implications for Protein Folding and Assembly

Because the N- and C-terminal amino acids of the catalytic (c) polypeptide chains of Escherichia coli aspartate transcarbamoylase (ATCase) are in close proximity to each other, it has been possible to form in vivo five different active ATCase variants in which the terminal regions of the wild-type c chains are linked in a continuous polypeptide chain and new termini are introduced elsewhere in either of the two structural domains of the c chain. These circularly permuted (cp) chains were produced by constructing tandem pyrB genes, which encode the c chain of ATCase, followed by application of PCR. Chains expressed in this way assemble efficiently in vivo to form active, stable ATCase variants. Three such variants have been purified and shown to have the kinetic and physical properties characteristic of wild-type ATCase composed of two catalytic (C) trimers and three regulatory (R) dimers. The values of Vmax for cpATCase122, cpATCase222, and cpATCase281 ranged from 16-21 mumol carbamoylaspartate per microgram per h, compared with 15 for wild-type ATCase, and the values for K0.5 for the variants were 4-17 mM aspartate, whereas wild-type ATCase exhibited a value of 6 mM. Hill coefficients for the three variants varied from 1.8 to 2.1, compared with 1.4 for the wild-type enzyme. As observed with wild-type ATCase, ATP activated the variants containing the circularly permuted chains, as shown by the lowering of K0.5 for aspartate and a decrease in the Hill coefficient (nH). In contrast, CTP caused both an increase in K0.5 and nH for the variants, just as observed with wild-type ATCase. Thus, the enzyme containing the permuted chains with widely diverse N- and C-termini exhibited the homotropic and heterotropic effects characteristic of wild-type ATCase. The decrease in the sedimentation coefficient of the variants caused by the binding of the bisubstrate ligand N-(phosphonacetyl)-L-aspartate (PALA) was also virtually identical to that obtained with wild-type ATCase, thereby indicating that these altered ATCase molecules undergo the analogous ligand-promoted allosteric transition from the taut (T) state to the relaxed (R) conformation. These ATCase molecules with new N- and C-termini widely dispersed throughout the c chains are valuable models for studying in vivo and in vitro folding of polypeptide chains.
Luminescence-based methods for sensing and detection of explosives

The detection of explosives and related compounds is important in both forensic and environmental applications. Luminescence-based methods have been widely used for detecting explosives and their degradation products in complex matrices. Direct detection methods utilize the inherent fluorescence of explosive molecules or the luminescence generated from chemical reactions. Direct detection methods include high-energy excitation techniques such as gamma-ray and x-ray fluorescence, detection of decomposition products by fluorescence or chemiluminescence, and detection following reduction to amines or another reaction to produce fluorescent products from the explosive. Indirect detection methods utilize the interference caused by the presence of explosive compounds with traditional processes of fluorescence and fluorescence quenching. Indirect detection methods include quenching of solution-phase, immobilized, and solid-state fluorophores, displacement of fluorophores, fluorescence immunoassay, and reactions that produce fluorescent products other than the explosive. A comprehensive review of these methods is presented.
A statistical approach for full-chip gate-oxide reliability analysis

Gate oxide breakdown is a key factor limiting the useful lifetime of an integrated circuit. Unfortunately, the conventional approach for full chip oxide reliability analysis assumes a uniform oxide-thickness for all devices. In practice, however, gate-oxide thickness varies from die-to-die and within-die and as the precision of process control worsens an alternative reliability analysis approach is needed. In this work, we propose a statistical framework for chip level gate oxide reliability analysis while considering both die-to-die and within-die components of thickness variation. The thickness of each device is modeled as a distinct random variable and thus the full chip reliability estimation problem is defined on a huge sample space of several million devices. We observe that the full chip oxide reliability is independent of the relative location of the individual devices. This enables us to transform the problem such that the resulting representation can be expressed in terms of only two distinct random variables. Using this transformation we present a computationally efficient and accurate approach for estimating the full chip reliability while considering spatial correlations of gate-oxide thickness. We show that, compared to Monte Carlo simulation, the proposed method incurs an error of only 1~6% while improving the runtime by around three orders.
THE PREPARATION OF 1-(α-AMINOALKYL) - BENZOTRIAZOLES IN AQUEOUS SOLUTION

(1989). THE PREPARATION OF 1-(α-AMINOALKYL) - BENZOTRIAZOLES IN AQUEOUS SOLUTION. Organic Preparations and Procedures International: Vol. 21, No. 2, pp. 135-139.
Food habits of gray bats in Kentucky

Foods eaten by gray bats ( Myotis grisescens ) were determined from fecal samples from bats netted along foraging routes on Jessamine Creek, Jessamine Co., Kentucky. Eleven families from nine orders of insects were eaten, with Coleoptera, Trichoptera, Diptera, and Lepidoptera occurring at the highest percent volumes. Three coleopteran families (Carabidae, Chrysomelidae, and Scarabaeidae) were common in the diet of gray bats. Ephemeropterans were not observed in fecal samples, despite their availability at foraging sites. Diet shifted across sampling periods. Data indicate that gray bats foraged both opportunistically and selectively at that site.
Regime shifts in interest rate volatility

Abstract I find evidence of regime shifts in interest rate volatility using short-rate data from the U.S., the U.K., Japan, and Canada. The regime shifts, if unaccounted for, could lead to spurious volatility persistence when the volatility processes are estimated with the stochastic volatility (SVOL) model. In contrast, the apparent persistence in volatility drops sharply in three out of the four countries when I estimate the volatility processes with the regime-switching stochastic volatility (RSSV) model. I also contribute to the literature by showing how to account for correlation in the regime-switching stochastic volatility model, which is important for modeling asymmetric volatility.
The effect of the Mihalas, Hummer, and Daeppen equation of state and the molecular opacity on the standard solar model

Improvements to the Yale Rotating Stellar Evolution Code (YREC) by incorporating the Mihalas-Hummer-Daeppen equation of state, an improved opacity interpolation routine, and the effects of molecular opacities, calculated at Los Alamos, have been made. the effect of each of the improvements on the standard solar model has been tested independently by computing the corresponding solar nonradial oscillation frequencies. According to these tests, the Mihalas-Hummer-Daeppen equation of state has very little effect on the model's low l p-mode oscillation spectrum compared to the model using the existing analytical equation of state implemented in YREC. On the other hand, the molecular opacity does improve the model's oscillation spectrum. The effect of molecular opacity on the computed solar oscillation frequencies is much larger than that of the Mihalas-Hummer-Daeppen equation of state. together, the two improvements to the physics reduce the discrepancy with observations by 10 microHz for the low l modes.
Acoustic structure and propagation in highly porous, layered, fibrous materials

This work is concerned primarily with the acoustic structure and propagation of sound in highly porous, layered, fine fiber materials. Of particular interest is the utilization of the Kozeny number for determining the static flow resistance and the static structure factor based on flow permeability measurements. In this formulation the Kozeny number is a numerical constant independent of volume porosity at high porosities. The other essential parameters are then evaluated employing techniques developed earlier for open‐cell foams. [J. Acoust. Soc. Am. 72, 879–887 (1982)]. The attenuation and progressive phase characteristics in bulk samples were measured and compared with predicted values. The agreements on the whole were very satisfactory.
Inverse problem on the line without phase information

The one-dimensional Schrodinger equation is considered for real potentials that are integrable, have finite first moment, and contain no bound states. The recovery of a potential with support in a right half-line is studied in terms of the scattering data consisting of the magnitude of the reflection coefficient, a known potential placed to the left of the unknown potential, and the magnitude of the reflection coefficient of the combined potential. Several kinds of methods are described for retrieval of the reflection coefficient corresponding to the unknown potential. Some illustrative examples are provided.
Bulboventricular foramen size in infants with double-inlet left ventricle or tricuspid atresia with transposed great arteries: Influence on initial palliative operation and rate of growth

Bulboventricular foramen obstruction may complicate the management of patients with single left ventricle. Bulboventricular foramen size was measured in 28 neonates and infants greater than 5 months old and followed up for 2 to 5 years in those patients whose only systemic outflow was through the foramen. The bulboventricular foramen was measured in two planes by two-dimensional echocardiography, its area calculated and indexed to body surface area. One patient died before surgical treatment. The mean initial bulboventricular foramen area index was 0.94 cm2/m2 in 12 patients (Group A) in whom the foramen was bypassed as the first procedure in early infancy. The remaining 15 patients underwent other palliative operations but the bulboventricular foramen continued to serve as the systemic outflow tract. There was one surgical death. Six (Group B) of the 14 survivors developed bulboventricular foramen obstruction during follow-up (mean initial bulboventricular foramen area index 1.75 cm2/m2). The remaining eight patients (Group C) did not develop obstruction during follow-up and had an initial bulboventricular foramen larger than that in the other two groups (mean initial bulboventricular foramen area index 3.95 cm2/m2). All patients with an initial bulboventricular foramen area index less than 2 cm2/m2 who did not undergo early bulboventricular foramen bypass developed late obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)
The Synthesis and Crystal Structure of [BiI 2 (tpy) 2 ][Bi 2 I 7 (tpy)]: A New Metal Halide Material

[BiI2(tpy)2][Bi2I7(tpy)] (1) (tpy = 2,2′:6′2′′-terpyridine), a new compound containing a discrete bismuth halide anion, has been synthesized solvothermally and characterized by single crystal X-ray diffraction. The solvothermal reaction between BiI3, Zn(NO3)2 · 6H2O, and 2,2′:6′2′′-terpyridine in an ethanol/water solvent mixture resulted in the title compound. The anion and cation of this compound both contain bismuth, iodide ligands, and the organic ligand. The anion is composed of two face-sharing bismuth polyhedra, one of which is coordinated in a tridentate fashion to a disordered tpy ligand; and the remaining coordination sites at each Bi center are occupied by iodide ligands. The cation of the compound is a distorted, eight-coordinate polyhedron with a bismuth center, two iodide ligands, and six nitrogen atoms from two, tridentate tpy ligands. [BiI2(tpy)2][Bi2I7(tpy)] crystallizes in the triclinic space group P $$ \overline{1} $$ with the following lattice parameters: a = 10.0744(5) A, b = 16.6115(8) A, c = 18.5333(9) A, α = 102.6490(10)°, β = 101.0850(10)°, and γ = 93.9160(10)°. The title compound, [BiI2(tpy)2][Bi2I7(tpy)], was synthesized solvothermally by the reaction between BiI3 and 2,2′:6′2′′-terpyridine. Single crystal X-ray diffraction analysis reveals that the molecular structure contains one anion and one cation, both of which contain bismuth, iodine, and the tpy ligand, a situation not typically observed in these types of compounds.
Stability of Factor Structure of the WISC for Normal Negro Children from Pre-School Level to First Grade

In order to determine the changes in mental factor structure with increasing age and educational maturity, two analytic studies were made. In 1961, 111 Negro pre-school children were examined with the Wechsler Intelligence Scale for Children and 4 reference tests. This battery was repeated 1 yr. later with 103 of the same children. The 10 standard WISC subtests, except Coding, were split into 2, 3, or 4 parts to yield as many variables as possible. Kaiser's varimax rotation was applied to the 30 by 30 matrix. Evidence is presented supporting 9 statistically significant uncorrelated factors at both the pre-school level and after 1 yr. of school. At least 8 factors are readily identified by WISC subtests or by combinations of WISC subtests. By age 6 differential mental abilities are clearly discernible. Between pre-school and the end of the first grade WISC mental factors are not appreciably altered by age, education or training. Eight factors extracted at the pre-school level are stable and congruent with ...
PHOTOTAXIS IN EUGLENA—V. PHOTOSUPPRESSION OF PHOTOTACTIC ACTIVITY BY BLUE LIGHT*,†

— The phototactic response of Euglena gracilis is suppressed when the organisms are exposed to bright light of wavelength less than 650 nm. Activity returns in the dark, approximately 40 min being required for full restoration. Action spectral measurements demonstrate that the receptor pigment which mediates the suppression response may be a flavoprotein. Evidence is presented which indicates that photosuppression involves a direct action on the photo-tactic apparatus, perhaps a photobleaching of the tactic photoreceptor pigment.
Advanced practice nursing role delineation in acute and critical care: Application of the Strong Model of Advanced Practice

Abstract Purpose: This purpose of this study was to differentiate between the roles of clinical nurse specialists and acute care nurse practitioners. Background and Significance: Hypothesized blending of the clinical nurse specialist and acute care nurse practitioner roles is thought to result in an acute care clinician who integrates the clinical skills of the nurse practitioner with the systems knowledge, educational commitment, and leadership ability of the clinical nurse specialist. Ideally, this role blending would facilitate excellence in both direct and indirect patient care. The Strong Model of Advanced Practice, which incorporates practice domains of direct comprehensive care, support of systems, education, research, and publication and professional leadership, was tested to search for practical evidence of role blending. Methods: This descriptive, exploratory, pilot study included subjects (N = 18) solicited from an academic medical center and from an Internet advanced practice listserv. Questionnaires included self-ranking of expertise in practice domains, as well as valuing of role-related tasks. Content validity was judged by an expert panel of advanced practice nurses. Results: Analyses of descriptive statistics revealed that clinical nurse specialists, who had more experience both as registered nurses and in the advanced practice nurse role, self-ranked their expertise higher in all practice domains. Acute care nurse practitioners placed higher importance on tasks related to direct comprehensive care, including conducting histories and physicals, diagnosing, and performing diagnostic procedures, whereas clinical nurse specialists assigned greater importance to tasks related to education, research, and leadership. Conclusions: Levels of self-assessed clinical expertise as well as valuing of role-related tasks differed among this sample of clinical nurse specialists and acute care nurse practitioners. Groundwork has been laid for continuing exploration into differentiation in advanced practice nursing roles. Implications: As the clinical nurse specialist role changes and the acute care nurse practitioner role emerges, it is imperative that advanced practice nurses describe their contribution to health care. Associating advanced practice nursing activities with outcomes will help further characterize these 2 advanced practice roles. (Heart Lung® 2000;29:210-21.)
Formal alliances, 1815—1939 A Quantitative Description

Although students of world politics have come increasingly to speak of their empirical domain as a social system, little effort has gone into the systematic observation and measurement of its formal or informal structure. One structural attribute of the inter national system which leaves a definite trace and is therefore readily measurable, is that of alliance patterns. This paper examines all written (peacetime only) alliances among system members, describes the procedures for classifying them, and then transforms such information into quantitative indicators of alliance aggregation for various forms of the international system for every year between 1815 and 1939. Such data make it possible to treat this particular system attribute as either a dependent or an inde pendent variable for purposes of hypothesis testing or exploration in world politics.
Passive, in-home gait measurement using an inexpensive depth camera: Initial results

In-home gait measurement results from the apartments of seven older adults obtained using an environmentally mounted depth camera, the Microsoft Kinect, are presented. Previous work evaluating the use of the Kinect for in-home gait assessment in a lab setting has shown the potential of this approach. In this work, a single Kinect sensor and computer have been deployed in five apartments, two of which contain multiple residents, in an independent living facility for older adults. Data collected in the five apartments, along with techniques for generating automated gait measurements from the data, are presented.
Mechanisms of hyperbaric oxygen-induced neuroprotection in a rat model of subarachnoid hemorrhage

Acute cerebral ischemia occurs after subarachnoid hemorrhage (SAH) because of increased intracranial pressure (ICP) and decreased cerebral perfusion pressure (CPP). The effect of hyperbaric oxygen (HBO) on physiological and clinical outcomes after SAH, as well as the expressions of hypoxia-inducible factor-1alpha (HIF-1alpha) and its target genes, such as BNIP3 and VEGF was evaluated. Eighty-five male SD rats (300 to 350 g) were randomly assigned to sham, SAH, and SAH+HBO groups. Subarachnoid hemorrhage was induced by endovascular perforation. Cortical cerebral blood flow (CBF), ICP, brain water content, brain swelling, neurologic function, and mortality were assessed. HBO (100% O2, 2.8 ATA for 2 h) was initiated at 1 h after SAH. Rats were sacrificed at 24 h to harvest tissues for Western blot or for histology. Apoptotic morphology accompanied by strong immunostaining of HIF-1alpha, VEGF, and BNIP3 were observed in the hippocampus and the cortex after SAH. Increased expressions of HIF-1alpha, VEGF, and BNIP3 were quantified by Western blot. HBO reduced the expressions of HIF-1alpha, VEGF, and BNIP3, diminished neuronal damage and improved CBF and neurologic function. HBO reduced early brain injury after SAH, probably by inhibition of HIF-1alpha and its target genes, which led to the decrease of apoptosis and preservation of the blood-brain barrier function.
Glepidotin C: A minor antimicrobial bibenzyl from Glycyrrhiza lepidota

Abstract Further examination of chromatographic residues from an earlier study of the antimicrobial constituents of American licorice. Glycyrrhiza lepidota , resulted in the isolation of a small amount of a new, weakly active, bibenzyl named glepidotin C. Spectroscopic measurements led to the assignment of the structure of this compound as 2-(2-hydroxy-3-methylbut-3-enyl)-5-(1-phenylethyl)-1,3-benzenediol.
Studies on the biosynthesis of 5-ribosyluracil phosphate in Neurospora crassa 36601

Abstract 1. (1) While the pyrimidine portion of 5-ribosyluracil phosphate has been found to be derived from orotic acid in yeast, it has been found to be derived largely from cytidine of the medium in the pyrimidine requiring mutant Neurospora, Neurospora crassa 36601. 2. (2) Experiments with [2- 14 C]uracil indicate that uracil is not an intermediate in the conversion of cytidine into 5-ribosyluracil phosphate. 3. (3) Reasons are presented for the belief that a uridine phosphate, such as uridine 5′-phosphate, is an intermediate in the biosynthesis of 5-ribosyluracil phosphate. 4. (4) The possibility is discussed that 5-ribosyluracil phosphate is normally derived from a pathway in which orotic acid is first incorporated into uridine 5′-phosphate, which then forms an unknown intermediate and is finally converted to 5-ribosyluracil phosphate.
Utility of transesophageal echocardiography in interatrial septal puncture during percutaneous mitral balloon commissurotomy

Percutaneous mitral balloon commissurotomy is an alternative to surgical therapy in selected patients with symptomatic mitral stenosis.1 Transseptal cardiac catheterization is the most common approach and complications are rare with experienced personnel but include perforation of the aorta, atria and left ventricular wall.2 Transthoracic 2-dimensional echocardiography has also been used to guide balloon valvuloplasty catheters as well as the transseptal needle across the atrial septum3 but may be limited by an inadequate acoustic window, transducer and catheter images superimposed in the fluoroscopic field and suboptimal atrial septum and fossa ovalis visualization. In contrast, transesophageal echocardiography (TEE) encounters minimal acoustic impedance due to lung or skeletal tissue and yields very high quality images.4 Using TEE, successful visualization of the atrial septum and the membranous portion of fossa ovalis is practically always achieved. The purpose of the current study is to evaluate the usefulness of TEE as an aid to transseptal cardiac catheterization during balloon commissurotomy.
Presynaptic mechanisms of endocannabinoid-mediated long-term depression in the hippocampus.

Endogenous cannabinoids (eCBs) mobilized from postsynaptic cells activate presynaptic cannabinoid receptors and thereby inhibit synaptic transmitter release. The inhibition can be either brief (seconds) or long-lasting (minutes to hours). Recent studies provide insight into the presynaptic mechanisms responsible for long-lasting, eCB-mediated long-term depression. Among these, the proteins PKA and RIM1α appear to be crucial, although other possibilities are emerging.
Do we understand heavy-ion fusion reactions of importance in stellar evolution?

Since the first observation of hindrance in heavy-ion fusion, many extrapolated cross sections for astrophysically interesting fusion reactions, such as 12C + 12C, 12C + 16O, 16O + 16O, 24O etc. need to be reexamined. In this contribution, the effects of fusion hindrance at extreme low energies are discussed.
Testing the Time-Reversal Modified Universality of the Sivers Function

We derive the time-reversal modified universality for both quark and gluon Sivers functions from the parity and time-reversal invariance of QCD. We calculate the single transverse-spin asymmetry of inclusive lepton from the decay of W bosons in polarized proton-proton collision at the Brookhaven National Laboratory Relativistic Heavy Ion Collider (RHIC), in terms of the Sivers function. We find that, although the asymmetry is diluted from the W decay, the lepton asymmetry is at the level of several percent and is measurable for a good range of lepton rapidity at RHIC. We argue that this measurable lepton asymmetry at RHIC is an excellent observable for testing the time-reversal modified universality of the Sivers function.
The basis of polarity in neurons

It has been recognized since the very early studies on the cytology of vertebrate nervous systems that neurons produce two fundamentally different types of neurite, the axon and the dendrite. Contemporary studies using electron microscopy have defined in detail the many structural differences between axons and dendrites. Perhaps the best known of these differences concerns ribosomes and Golgi elements, which are present in dendrites, but are absent from axons. In this article, we present a possible explanation for this compartmentalization which is based on current understanding of organelle transport in cells and our recent demonstration of a fundamental difference in the organization of the microtubule-based transport systems that convey organelles into the axon or into the dendrite.
Coherent electron nanodiffraction from perfect and imperfect crystals

Abstract The theory of coherent electron nanodiffraction from strained crystals is developed, based on the column approximation. Contributions to the diffraction pattern from different parts of the crystal under the illumination are considered, and a treatment of high-order weak reflections and diffuse scattering is given based on perturbation theory. Ultimate limits to the spatial resolution of coherent electron nanodiffraction in electron microscopy are discussed. A relationship between higher order Laue zone line width, probe size and specimen thickness is given, based on the uncertainty principle. Failure conditions of the column approximation for coherent convergent beam electron diffraction are tested by numerical simulations using the multislice method applied to a supercell containing a simulated strain field. The results and their implications are discussed. Phase determination of dynamical beams using overlapping orders is shown to require greater source coherence than that which is needed under...
Expression vectors permitting cDNA cloning and enrichment for specific sequences by hybridization/selection.

Abstract A set of vectors is described which allow the efficient cloning of full-length cDNAs, using a modification of the method of Okayama and Berg [Mol. Cell Biol. 2 (1982) 161–170], and enrichment of specific sequences directly from cDNA libraries by hybridization/selection. The vectors pcDpolyB + and pcDpolyB − are derived from an expression vector described previously [Okayama and Berg, Mol. Cell Biol. 3 (1983) 280–289] and allow expression of cloned cDNAs in eukaryotic cells from the simian virus 40 early region promoter. The vectors BSB+ and B SB- contain convenient priming sites for sequence analysis and the T3 and T7 RNA polymerase promoters, allowing synthesis of transcripts homologous to either strand of the cDNA. Each of these vectors also contains the intergenic region from the bacteriophage f1 permitting synthesis of single-stranded (ss) copies of the cDNA libraries. Enrichment for cDNAs containing sequences homologous to the hypoxanthine phosphoribosyl transferase gene from an ss copy of a cDNA library by hybridization/selection is demonstrated. Levels of enrichment sufficient for the direct cloning of specific sequences without requiring colony or plaque hybridizations were obtained. Libraries constructed from different cell types can be screened against each other to create sublibraries highly enriched in sequences specific to a single cell type. The availability of cDNA expression libraries enriched for cell-type-specific cDNAs should greatly enhance the efficiency with which cDNAs can be identified on the basis of functional assays.
ScatterType: a Reading CAPTCHA Resistant to Segmentation Attack

A reading-based CAPTCHA designed to resist character-segmentation attacks, called 'ScatterType,' is described. Its challenges are pseudorandomly synthesized images of text strings rendered in machine-print typefaces: within each image, characters are fragmented using horizontal and vertical cuts, and the fragments are scattered by vertical and horizontal displacements. This scattering is designed to defeat all methods known to us for automatic segmentation into characters. As in the BaffleText CAPTCHA, English-like but unspellable text-strings are used to defend against known-dictionary attacks. In contrast to the PessimalPrint and BaffleText CAPTCHAs (and others), no physics-based image degradations, occlusions, or extraneous patterns are employed. We report preliminary results from a human legibility trial with 57 volunteers that yielded 4275 CAPTCHA challenges and responses. ScatterType human legibility remains remarkably high even on extremely degraded cases. We speculate that this is due to Gestalt perception abilities assisted by style-specific (here, typeface-specific) consistency among primitive shape features of character fragments. Although recent efforts to automate style-consistent perceptual skills have reported progress, the best known methods do not yet pose a threat to ScatterType. The experimental data also show that subjective rating of difficulty is strongly (and usefully) correlated with illegibility. In addition, we present early insights emerging from these data as we explore the ScatterType design space -- choice of typefaces, 'words', cut positioning, and displacements -- with the goal of locating regimes in which ScatterType challenges remain comfortably legible to almost all people but strongly resist mahine-vision methods for automatic segmentation into characters.
Gels Composed of Sodium-Aluminium Silicate, Lake Magadi, Kenya

Sodium-aluminum silicate gels are found in surficial deposits as thick as 5 centimeters in the Magadi area of Kenya. Chemical data indicate they are formed by the interaction of hot alkaline springwaters (67 degrees to 82 degrees C; pH, about 9) with alkali trachyte flows and their detritus, rather than by direct precipitation. In the process, Na(2)O is added from and silica is released to the saline waters of the springs. Algal mats protect the gels from erosion and act as thermal insulators. The gels are probably yearly accumulates that are washed into the lakes during floods. Crystallization of these gels in the laboratory yields analcite; this fact suggests that some analcite beds in lacustrine deposits may have formed from gels. Textural evidence indicates that cherts of rocks of the Pleistocene chert series in the Magadi area may have formed from soft sodium silicate gels. Similar gels may have acted as substrates for the accumulation and preservation of prebiological organic matter during the Precambrian.
Decreased coronary microvascular reactivity after cardioplegic arrest in patients with uncontrolled diabetes mellitus

Background We investigated the effects of cardioplegic arrest and reperfusion on coronary arteriolar responses to endothelium-dependent and -independent vasodilators and associated signaling pathways in uncontrolled diabetic, well controlled diabetic, and case-matched nondiabetic patients undergoing coronary artery bypass graft surgery. Methods Coronary arterioles from harvested right atrial tissues were dissected pre- and post–cardioplegic arrest and reperfusion from uncontrolled diabetic ( n = 10; hemoglobin A1c = 9.3 ± 0.3), well controlled diabetic ( n = 10; hemoglobin A1c = 6.2 ± 0.2), and nondiabetic patients ( n = 10; hemoglobin A1c = 5.1 ± 0.1) undergoing coronary artery bypass graft surgery. Results The baseline microvascular response to adenosine 5′-diphosphate, substance P, and sodium nitroprusside of arterioles from uncontrolled diabetic patients were decreased compared to the respective response from nondiabetic or well controlled diabetic patients ( P P P Conclusion Uncontrolled diabetes is associated with endothelium-dependent and -independent vascular dysfunction of coronary arterioles. In addition, uncontrolled diabetes worsens the recovery of coronary arteriolar function after cardioplegic arrest and reperfusion. These alterations are associated with an increased expression/activation of protein kinase C-α and protein kinase C-β and enhanced oxidative stress.
Risk coordinative maneuvers during buyer-seller negotiations

Abstract With the recent growing interest in buyer-seller negotiations, the author proposes a conceptual model for high-risk coordinative behavior for industrial buyers. An overview of some of the existing literature pertaining to industrial negotiation provides a sufficient foundation for model development. These constructs describe the persuasive antecedents associated with high-risk coordinative behavior. The author suggests some relevant research questions relating to the effectiveness and efficacy of the model for future empirical testing.
Management of intractable back pain from caudal ependymoma with spinal methylprednisolone, bupivacaine and morphine.

Abstract We report the successful management of severe, intractable low back pain in a 21-year-old female with an ependymoma of the cauda equina using intermittent intrathecal methylprednisolone (20 mg), bupivacaine (2.5 mg) and morphine (1 mg) injections over a 2-year period.
A stochastic bivariate ecology model for competing species

Abstract The aim of the present paper is concerned with the formulation of a general stochastic bivariate model without specifying the nature of the relationship between two species. The stochastic model is equally well adopted to either the predator-prey type of interaction between two species or to mutual competition. From the bivariate distribution function estimators for the parameters in the stochastic model can be easily derived and a realistic insight into the behavior of the system can be gained.
Role of neutrophil elastase in bone marrow failure syndromes: molecular genetic revival of the chalone hypothesis.

Two forms of inherited deficiency of neutrophil numbers are cyclic hematopoiesis and severe congenital neutropenia. In cyclic hematopoiesis, neutrophil counts oscillate opposite monocytes in a 3-week cycle. Severe congenital neutropenia consists of static neutropenia and a predisposition to myelodys
A custom tracheostoma valve retainer for the laryngectomy patient

This article describes fabrication of a custom tracheostoma valve retainer for postlaryngectomy voice rehabilitation. Impression technique, laboratory technique, and materials are discussed.
Valency, valence degeneracy, ferroelectricity, and superconductivity

Applications of the oxidation state and valent state systems are discussed with particular emphasis on inorganic solids. Areas addressed include mixed valency, mixed electronic configurations, disproportionation and superconductivity, real charges, valence degeneracy, and stabilization of high oxidation states. The most significant advance to the oxidation state system since its inception is the bond valence approach where every bond between a cation and an anion is assigned a valence value. It is demonstrated that this bond valence approach can be used to understand ferroelectric transitions in oxides whether or not d orbitals are involved. Differences between the oxidation state system and the valent state system are delineated, and examples of common misuse of these systems are discussed.
Algorithm to Determine Minimum Contingency Set in Voltage Collapse Scenario

This investigation explores how many system elements must be outaged in order to cause system-wide voltage collapse. The IEEE 118-bus case was used to conduct simulations which implemented continuous steady-state load flows and power-voltage curves as indicators. The base case maintained constant power factor load throughout, and applied given generator capability curve data and automatic generation control data to each unit. Using the n - 1 contingency list, sensitivities were found for the system with respect to increased system load given a unique n - 1 topology. The minimum number of system elements can be found by systematically repeating this process while outaging the most sensitive element at each step.
Glenoid Bone Loss in the Setting of an Anterior Labroligamentous Periosteal Sleeve Avulsion Tear

Background:Glenoid bone loss is a factor that has been inversely associated with the success of shoulder instability repair. Recently, patients with an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion have also been identified as having a higher failure rate after surgical repair.Purpose:To determine differences in the amount of glenoid bone loss and to compare demographic factors of instability in patients with and without ALPSA tears.Study Design:Case-control study; Level of evidence, 3.Methods:Over a 3-year period, all patients (N = 83) who were treated for anterior shoulder instability at a single institution were reviewed retrospectively. A total of 39 (47%) were identified as having an ALPSA lesion and 44 (53%) as having no ALPSA tear. Glenoid bone loss was determined in 2 ways: (1) radiographically by 3-dimensional computed tomography (3D CT) (humeral head digitally subtracted by 3 blinded observers) and (2) with arthroscopic techniques at the time of surgery. Demographic data su...
THE RETENTION AND PHYSIOLOGICAL ROLE OF UREA IN THE ELASMOBRANCHII

Summary. The high urea content (2·0 and 2·5 per cent.) that characterises the blood, body fluids and tissues of the Elasmobranchii owes its origin to the relative impermeability of the gills and integument to this substance, and to the circumstance that the urea is actively conserved by the elasmobranch kidney. In consequence of this physiological uraemia, the elasmobranch is osmotically superior to its environment, even in sea water, and is able to absorb at least a minimum quantity of water for the formation of a urine that is isotonic or hypotonic to the blood, in accordance with the osmotic limitations of the fish kidney. We may suppose that the uraemic state tends to develop and to be regulated more or less automatically; urea is constantly being formed by the ordinary metabolic combustion of protein; water shortage leads to oliguria and urea retention, and the accumulated urea in the blood raises the osmotic pressure of the latter to a point where water is again available by direct absorption. Water plethora (as in fresh water) leads to diuresis and increased urea excretion, which in turn lowers the osmotic pressure of the blood and in some measure, at least, reduces the rate of water absorption. Trimethylamine oxide, which imparts about one-quarter as much osmotic pressure to the blood as does urea, is also conserved by the elasmobranch; the fact that this substance is present in the urine in lower concentration than in the blood suggests that, like urea, it is actively reabsorbed from the glomerular filtrate. This physiological uraemia is apparently an archaic biochemical habit acquired early in elasmobranch evolution, since it is shared by the divergent orders of the subclass. Presumably it is a secondary mode of osmotic regulation superimposed upon the more primitive one of branchial regulation, as observed in the teleostomes. The cleidoic egg, unique (among the fishes) in the Elasmobranchii, and the viviparous mode of reproduction, are viewed as adaptations to urea retention, protecting the embryo against the loss of urea during its early development. Urea retention enables the Elasmobranchii to maintain a considerably greater rate of urine formation (water excretion) than is observed in the marine teleosts, a fact that perhaps explains why the former do not show the glomerular degeneration or the aglomerular development observed in the latter. Whereas urine formation in the marine teleosts appears to be carried on normally at a reduced level considerably below the maximum possible rate, the elasmobranchs appear to maintain a maximal (though small) degree of glomerular activity at all times. Unlike the teleosts, they appear to possess no mechanisms for reducing glomerular activity; it may be that because of their superior osmotic position, due in turn to their physiological uraemia, they have never been faced with the necessity for conserving water to an excessive degree in the kidneys, and have therefore never evolved the means for doing so.
Editorial: Prevention in Child Health Psychology and the Journal of Pediatric Psychology

Prevention science is a cornerstone of the field of public health. Consistent with that view, it is a science seeking to reduce and avoid the development of illness and lifestyle-related health risks (Institute of Medicine, 2002). Prevention is sometimes defined by where its activities take place in the illness process, and at other times by the level of risk in the population of interest. When defined by the illness process, three levels of prevention are commonly referred to. These levels are primary, secondary, and tertiary prevention. Primary prevention emphasizes prevention activities taking place prior to the onset of illness, secondary prevention emphasizes prevention activities taking place among those at risk for illness (e.g., enhancing opportunities to prevent illness progression), and tertiary prevention emphasizes prevention activities taking place after illness diagnosis (e.g., preventing or slowing further progression, restoring functioning, and reducing morbidity) (Commission on Chronic Illness, 1957). When defined by population risk, universal prevention emphasizes activities promoting health or decreasing illness for all individuals regardless of their risk status, selective prevention emphasizes activities targeting at risk groups or those showing early illness signs, and indicated prevention refers to activities preventing illness progression among those in the very highest risk categories (Mrazek & Haggerty, 1994). Other forms of prevention include education, counseling, laws, policies, and environmental regulations—all of which are designed to protect public health and welfare (Friis & Sellers, 2004). With these definitions in mind, potential topics falling within the prevention science section of the Journal of Pediatric Psychology are those most likely addressed by one or more national prevention frameworks, such as Healthy People (www.healthypeople.gov) or the Preventive Services Task Force (www.ahrq.gov/clinic/uspstfix.htm), or by organizations such as the American Academy of Pediatrics (www.aap.org), and that seek to promote and improve health in the young. Examples of these topics include social and biobehavioral aspects of alcohol, tobacco, and substance use, mental health, HIV/AIDS, violence, injuries and accidents, pregnancy, suicide, delinquency, sexually transmitted diseases, obesity, diet/nutrition, and physical activity, and topics focusing on prevention theory, methods, and related matters (e.g., structure, process, and content of prevention efforts, as well as discussion of the timing, measurement, duration, reach, moderation, and mediation of prevention). Recognizing that the targets of prevention efforts are often multifaceted and include biological, social, environmental, psychological, and behavioral processes, work that seeks to better define, elucidate, model, and understand these influences and their interactions are especially important.
Electron microscopy of rabbit lens nucleoli.

Abstract Electron microscopy studies of adult rabbit lens revealed the following: the nucleoli of the lens epithelial cells are relatively small, and each consists of a central fibrillar component (approximately 50 A in diameter) and a peripheral granular component usually of chromatin size (250-200 A in diameter). The nucleolus slightly enlarges at the equatorial region, and exhibits a partial superimposition of the granular component with the fibrillar component. An enormously large nucleolus is seen at the superficial cortical fiber layers. It is composed of an enlarged fibrillar component with a prominent network pattern or reticulation, and the granular component here is mostly superimposed on the fibrillar component, the granule size ranging from a chromatin size to much smaller ones. These sequential changes suggest that chromatin particles may participate in the formation of a fibrillar component, thus contributing to the nucleolar enlargement. In deeper layers of the lens fiber, aging changes of the nucleoli are found, apparently proceeding as follows: first, the condensation of the nucleolar components occur, resulting in a dense rounded nucleolus with several holes. These nucleolar constituents are finally dispersed into the nucleoplasm at a further deeper region.
Knockdown of Brm and Baf170, Components of Chromatin Remodeling Complex, Facilitates Reprogramming of Somatic Cells.

The SWI/SNF (SWItch/Sucrose NonFermentable or BAF, Brg/Brahma-associated factors) complexes are epigenetic modifiers of chromatin structure and undergo progressive changes in subunit composition du...
Is Canine Eruption Velocity Affected by the Presence of Allograft Within a Repaired Alveolar Cleft

Purpose To assess the rate of canine eruption in alveolar clefts repaired with cancellous autograft versus cancellous autograft mixed with allograft. Materials and Methods This was a retrospective cohort study of patients in mixed dentition who underwent primary repair of uni- or bilateral alveolar cleft defects. Patients were divided into 2 groups based on the method of bony reconstruction (group 1, iliac crest autograft; group 2, iliac crest autograft harvested through a minimal access approach and mixed 1:2 with demineralized bone allograft). Secondary predictor variables were demographic and anatomic factors potentially related to canine eruption. The outcome variable was the velocity of canine eruption, measured as the change in vertical distance from the incisal edge to the maxillary occlusal plane (millimeters per month). Descriptive, bivariate, and linear regression statistics were computed. Results The study sample included 57 alveolar cleft defects; 19 were repaired with autograft alone and 38 were repaired with autograft plus allograft. The sample's mean age was 9.9 ± 2.3 years at the time of repair. Thirty-one clefts (54.4%) were part of a bilateral deformity. Canine root formation was 50% complete at the time of surgery in most patients (59.6%). Mean duration of follow-up was 23.7 ± 13.2 months. Mean canine eruption velocity was 0.20 ± 0.18 mm per month and was not associated with the method of bony repair ( P = .58). Conclusion The use of allograft bone to augment bone graft volume results in similar rates of canine eruption compared with autograft bone alone.
Does Latin America Exist? (And Is There a Confucian Culture?): A Global Analysis of Cross-Cultural Differences

Inglehart and Carballo’s first task in this article is to introduce the two underlying dimensions that, they argue, explain a good deal of the variation in people’s attitudes toward a broad range of questions (see Figure 1) across a number of societies. These dimensions contrast: traditional conceptions of authority characteristic of some of the least technologically developed societies with secular-rational conceptions of authority prevalent among most European and East-Asian societies as well as concerns about physical and economic survival typical of industrializing or “modern” societies in Eastern Europe and East Asia and quality-of-life concerns (opportunities for participation in politics and the workplace, meaningful leisure and environmental protection) found more commonly among advanced-industrial or “postmodern” societies in northwestern Europe. The average or mean scores of citizens of 43 societies on the broad range of questions Inglehart and Carballo ask produce clusters of societies (in Figures 4–6) that roughly duplicate geographic relationships. Thus the authors show that Latin America (or any other geographic region from other clusters in Figure 4) exists in terms of attitudinal similarities in addition to being a set of geographically proximate societies.