cssi/SciSciGPT-SciSciNet huggingface dataset:
Linkages of P and Al Export at High Discharge at the Bear Brook Watershed in Maine

Phosphorus chemistry in streams was evaluated at the paired watershed study at the Bear Brook Watershed, Maine. The West Bear catchment has been treated bimonthly since 1989 with 1,800 eq (NH4)S2O4 ha−1 yr−1. East Bear was the untreated reference watershed. During 1993, concentration of total phosphorus (P) in weekly samples from East and West Bear Brook ranged from 0 to 15 μg L−1. The median values were 2 and 4 µg L−1 for East and West Bear, respectively. During a high discharge event in January of 1995, the concentration of dissolved P remained relatively constant (≤ 3 μg L−1) as pH decreased from 5.63 to 5.08 and from 5.14 to 4.75 in East and West Bear, respectively. The concentration of total P increased to ca. 60 μg L−1 during the rising limb of the hydrograph in West Bear, four times the value in East Bear, total P then declined rapidly as discharge remained high followed by an increase. Dissolved Al increased in both streams during the episodic acidification. West Bear, the more acidic, had concentrations of dissolved Al four times those of East Bear (maximum of 1.1 mg L−1 versus 0.25 mg L−1). Acid-soluble particulate Al increased to 0.2 and 4.2 mg L−1 for East and West Bear, respectively, in parallel to total P (but was 102 greater than total P) and then declined in parallel to total P while discharge remained high. Total P, dissolved P, and particulate Al did not relate to pH. Total P and particulate Al and Fe were strongly correlated. Concurrently, base cations remained relatively constant or decreased slightly. Particulate acid-soluble Al exceeded particulate acid-soluble base cations. We hypothesize that the particulate P was occluded in, or adsorbed on, acid-soluble particulate Al(OH)3. This Al(OH)3 precipitates as emerging acidic groundwater degasses CO2 and pH rises. The export of Al and P is greater from the treated watershed because the induced acidification is translocating more Al from soils to the stream. Most of the export of P is related to acid-soluble Al particulate material
Poorly Lytic Bacteriophage from Dactylosporangium thailandensis (Actinomycetales)

Abstract Dactylosporangiophage A1 has a polygonal head (75 nm) with spherical capsomeres (3 nm) and a noncontractile tail (200 by 10 nm) with cross-striations which is terminated with at least three prongs which are used for attachment. It contains double-stranded deoxyribonucleic acid and produces very little lysis. Intracellular phage multiplication leads to the formation of crystalline aggregates of apparently complete virions. Plaques are formed only on certain substrains of Dactylosporangium thailandensis L1 and are always small (0.5 mm or less). They are clear on some substrains and turbid on others. Formation of plaques occurs only on one medium, Czapek agar with 0.2 to 0.4% yeast extract, 0.2% peptone, or a defined mixture of amino acids. Over 100 strains of bacteria, mainly actinomycetes, were screened in a futile attempt to find an indicator strain which is not a substrain of L1. The Dactylosporangium-phage system studied is considered to be a semiresistant carrier state.
School innovation in district context: Comparing traditional public schools and charter schools

Abstract Market reforms in education are part of the educational policy landscape in many countries. Central to arguments for market reforms is the idea that competition and choice will spur changes in schools to be more innovative, which in turn will lead to better student outcomes. We define innovation in terms of a practice's relative prevalence in a local district context. A charter school is innovative in its use of a practice if the traditional public schools in its local school district are not using that practice. We explore factors based on arguments for charter schools that may affect a charter schools’ propensity toward innovation to explain variation in levels of innovation across charter schools. We find that, on the whole, charter schools do not fulfill their promise of innovation. Teacher tenure is the most notable exception. Parental involvement is the only characteristic of charter schools that significantly predicts variation in levels of organizational innovativeness.
The accuracy of acoustic Doppler velocimetry measurements in turbulent boundary layer flows over a smooth bed

An evaluation of acoustic Doppler velocimetry (ADV) in the near-bed region of turbulent boundary layer flows is presented. Acoustic instruments have large sampling volumes compared with the smallest scales of motion in turbulent flows. This limits the accuracy of the technique, especially when making measurements close to the bed or in flows where large spatial gradients are present. These limitations are quantified by comparing ADV results to laser Doppler velocimetry (LDV) measurements from the same flow, and to direct numerical simulations of similar flows. A SonTek 16 MHz ADVField system was used in the evaluation. Measurements were made in a turbulent boundary layer over a smooth bed in a laboratory flume. The instrument was evaluated in both a fast and slow flow case with free stream velocities similar to those found in many natural environments. Additionally, results from an assessment of ADV sample volume size and position are reported. Mean velocities were within 5% accuracy down to 0.7 cm from the bed for the fast flow case and 1 cm for the slow flow case. ADV-derived Reynolds stresses matched well with those from LDV to within 1-2 cm of the bed, however turbulence intensities were found to deviate markedly up to 3-4 cm from the bed in some cases. In general, errors are largest close to the bed, but extend further away from the bed than reported in previous studies.
Saudi Aramco Oil Spill Approach, Prevention, and Readiness

ABSTRACT The oceans are a major source of food, livelihood, recreation, trade, and, in the case of many desert or semi-desert countries, a source of fresh water. In addition oceans serve as the primary carriers of another precious resource, petroleum. Saudi Aramco's environmental policy is to ensure that its operations do not create undue risk to the environment or public health. It also states that the company will conduct its operation with full concern for the protection of land, air, and water from harmful pollution. To carry out this policy, the company has taken several important precautionary and preparatory measures to ensure minimization of pollution from its operation at the various sectors. Saudi Aramco has adopted the age-old maxim that an ounce of prevention is better than a pound of cure. Since oil is a major potential source of marine pollution, the company has started with minimizing the accidental introduction of oil into the marine environment.
Application-specific customizable architectures of Utah neural interfaces

Abstract The demand to develop custom-designed, application-specific neural interfaces is increasing rapidly with the recent progress in the neuroscience [1] . Advanced neural interfaces capable of communicating with individual neurons may be most desirable for the closed-loop prosthetics control and new therapeutic applications; and emerging neuroscience research would benefit from an ability to implement novel array geometries on demand, to match the neural anatomy being studied. We have developed new techniques to build high aspect ratio Utah neural interface 10×10 arrays with electrodes up to 10 mm long with a 4mm2 footprint and also new high-density 20×20 arrays with 4mm2 footprint. The new techniques allow electrode and the array dimensions to be customized to the intended application. The current high aspect ratio arrays were used to record from the hippocampal area of rats and the highdensity arrays are designed to record and stimulate the pudendal nerve in pig models
Learning about water by hungry rats

Abstract In Experiments 1 and 2 hungry rats were trained in a straight alley with consistent food reward (FF), food and nonreward trials intermixed (FN), or food and water trials intermixed (FW). In Experiment 1 rats were tested with nonrewarded trials (extinction) and Groups FN and FW did not differ, both running faster then Group FF. In Experiment 2 rats were tested with consistent water reward, and Group FW ran faster then Group FN, which was superior to Group FF. In Experiment 3, one group of hungry rats was trained on a single alternating schedule of food and water in Phase 1 and was shifted to a single alternating schedule of food and nonreward in Phase 2 (Group FW); the second group (Group FN) received a single alternating schedule of food and nonreward in both phases. When Group FW was shifted to nonreward from water, performance to nonreward was temporarily disrupted. These results indicate that, contrary to previous conclusions, hungry rats can learn about water when drive is strong and food is received in the situation.
Coelomocytes as effector cells in earthworm immunity.

The results from this study support the following hypothetical mechanism for the rejection of xenografts by Lumbricus. Initially, coelomocytes are attracted to xenografts due to the stimulus of tissue injury. This results in clumping or nodule formation around injured and loose muscle fibers, and a general clumping of baso-phils. Clumping may entran acidophilic cells and/or attract such cells to the graft site. Because the graft is a foreign tissue, its foreignness also stimulates a cellular response. Basophils invade the muscular structure of the xenograft and more acidophilic cells accumulate at the graft site. The acidophilic cells have the canacity to digest the connective tissue elements which hold the muscle fibers of the graft in place. Dissolution of these connective tissue elements results in the release of muscle fibers. The presence of free foreign muscular tissue in the coelomic cavity acts as a stimulus for further accumulations of basophilic cells, which in turn form more capsules and may at...
Electromechanical Coupling in Rat Basilar Artery in Response to Morphine

Force development, intracellular membrane potential (Em), and voltage vs. current curves were measured in rat basilar artery to help elucidate the mechanism of action of morphine sulfate and a synthetic narcotic, meperidine hydrochloride, on this preparation. Morphine sulfate caused a dose-dependent contraction of these vessels, which was reversible with naloxone. Electrical studies show that morphine may act upon this vascular smooth muscle preparation by decreasing potassium conductance (gk). This hypothesis is supported by the findings that morphine sulfate depolarized these cells and increased the input resistance (rin) determined by the application of rectangular hyperpolarizing and depolarizing current pulses through the microelectrode during impalement and recording of the associated voltage changes (delta V). Meperidine hydrochloride had significantly less effect on this preparation than morphine sulfate. Further studies show that the vehicular medium used for the commercially available preparation of naloxone (viz. the methyl and propyl esters of p-hydroxybenzoic acid in a ratio of 9:1) is, in vitro, a vasodilator of cerebral vascular smooth muscle.
Hydrogenation of 3,4-epoxy-1-butene over Cu-Pd/SiO2 catalysts prepared by electroless deposition

Abstract Electroless deposition has been used to prepare Cu–Pd/SiO2 bimetallic catalysts wherein initial Cu coverages are limited only to the pre-existing Pd surface. Cu loading on the Pd surface can be systematically varied by modification of deposition kinetic parameters. In this case deposition time was used as the kinetic variable for the preparation of a series of Cu–Pd catalysts. These materials have been characterized using atomic absorption, CO chemisorption, and FT-IR (adsorption of CO), and then evaluated for the hydrogenation of 3,4-epoxy-1-butene, a functionalized olefin having many potential reaction pathways. Catalyst performance and characterization results suggest that Cu is not distributed in a monodisperse manner on the Pd surface, indicating the existence of autocatalytic deposition of Cu on Cu sites. The FT-IR results suggest that although CO adsorption on all sites is suppressed by Cu addition, initial Cu deposition occurs more readily on certain sites. The bimetallic Cu–Pd sites that are formed exhibit unusually high activity for EpB conversion and formation of unsaturated alcohols and aldehydes. This bimetallic effect on catalyst activity and selectivity is best explained, not by the existence of either ligand or ensemble effects, but rather by the bifunctional nature of the Cu–Pd sites present on the surface of these catalysts.
Sustainable Agricultural Practices Impact on Phosphate rock production

Abstract In many areas of the world sustainable agricultural practices are being touted as a necessity for a sustainable world. In the United Kingdom, China, and other nations the use of phosphorus fertilizers has been highlighted as an area in which more sustainable practices can be employed. The possible advantages of using organic sources for the phosphorus required by intensive agriculture are investigated. The potential for replacing inorganic sources of phosphorous is estimated. Limitations to the use of organic sources of phosphorus are considered and their impacts on the possible general use of organic sources are discussed.
Application of the Slab-Finite Element Method for Improvement of Rolled Bar Surface Quality

Summary This paper presents a methodology to improve bar surface quality by using the slab-finite element method. The improper design of roll geometries and roll pass sequences may lead to underfilled or overfilled conditions in the finished bars. The analysis was conducted using the special purpose slab-finite element program TASKS with some modifications. The parametric analysis was performed by using several roll geometries. The potential roll geometry to produce an excellent bar surface quality was selected for an in-plant trial and excellent bar surface quality was consistently obtained.
A Comparative Evaluation of Existing Grading Scales in Intracerebral Hemorrhage

In recent years, a multitude of clinical grading scales have been created to help identify patients at greater risk of poor outcome following ICH. We sought to validate and compare eight of the most frequently used ICH grading scales in a prospective cohort. Eight grading scales were calculated for 67 patients with non-traumatic ICH enrolled in the prospective intracerebral hemorrhage outcomes project (ICHOP) database. Receiver operating characteristic (ROC) analysis, including area under the curve (AUC) and maximum Youden Index were used to assess the ability of each score to predict in-hospital mortality, long-term (3 months) mortality, and functional outcome at 3 months (mRS ≥ 3). All scales demonstrated excellent to outstanding discrimination for in-hospital and long-term mortality, with no significant differences between them after controlling for the false discovery rate. All scales demonstrated acceptable to outstanding discrimination for functional outcome at 3 months, with the new ICH score demonstrating significantly lower AUC than 6 of the 8 scores. Essen ICH score was the only score to demonstrate outstanding discrimination for each outcome measure. Though significant differences were minimal in our cohort, we showed the existing selection of ICH grading scales to be useful in stratifying patients according to risk of mortality and poor functional outcome. Continued validation and comparison in large prospective cohorts will bring the goal of a singular prognostic model for ICH closer to fruition.
Haloperidol and MK-801 block increases in striatal calmodulin resulting from repeated amphetamine treatment

Repeated, intermittent treatment with amphetamine leads to a behavioral sensitization characterized in rats by an increase in locomotor activity and a more rapid onset of stereotyped behaviors. Induction of amphetamine sensitization is blocked by dopamine and N-methyl-D-aspartate (NMDA) antagonists. We have reported an increase in the content of the Ca2(+)-binding protein, calmodulin, in striatum and limbic forebrains from rats given repeated, intermittent amphetamine. To determine whether the increase was related to development of amphetamine sensitization, we examined whether the increase in calmodulin would be blocked by the dopamine antagonist, haloperidol, or the NMDA antagonist, MK-801. Rats were given amphetamine or saline twice weekly for 5 weeks. Thirty min prior to the amphetamine, rats were pretreated with 0.25 mg/kg haloperidol s.c., 0.1 mg/kg MK-801 i.p. or saline. Twice weekly amphetamine treatment increased calmodulin in the cytosol fraction of striatum and limbic forebrain and the increase was blocked by pretreatment with either haloperidol or MK-801. Neither antagonist alone affected cytosolic calmodulin. Haloperidol pretreatment, but not amphetamine or MK-801, increased calmodulin in striatal but not limbic forebrain membranes. Calmodulin-binding proteins were examined by biotinylated calmodulin blotting to determine if repeated, intermittent amphetamine altered the content of calmodulin-binding proteins in striatal cytosol or membranes. A band of 73 kDa was increased in striatal membranes. Immunoblotting with antisera to caldesmon, a cytoskeletal calmodulin-binding protein of 77 kDa, demonstrated increases in immunoreactivity in striatal membranes and cytosol. These data suggest that dopaminergic and glutamatergic components are required for the increases in striatal and limbic forebrain calmodulin and that the rise in calmodulin is related to the development of amphetamine sensitization. In addition, the content of select calmodulin-binding proteins can be coordinately regulated with increases in calmodulin.
Keratin filaments of corneal epithelial cells

Abstract Intermediate filaments with a diameter of approximately 8–10 nm are present in great abundance in the cytoplasm of corneal epithelial cells. In order to study the immunological relationship between these filaments and the tonofilaments of epidermal cells, we prepared an antiserum against keratin proteins isolated from the stratum corneum of human epidermis. Immunofluorescent staining of frozen sections of rabbit and human corneas with this anti-keratin antiserum resulted in the intense staining of the entire corneal epithelium, but no staining of the endothelium or any of the stromal components. Similar staining of cultured rabbit and human corneal epithelial cells revealed a cytoplasmic network of wavy fibers distinct from microfilaments and microtubles. Electron microscopic examination of cultured rabbit corneal epithelial cells showed that they formed a stratified squamous structure with prominent desmosomal cell-cell junctions and wavy bundles of cytoplasmic 8–10 nm filaments. These results suggest that the 8–10 nm filaments of corneal epithelium are immunologically related to tonofilaments of the epidermis and are composed of keratin proteins. Since corneal epithelium is the only keratin-containing cell type in normal cornea, anti-keratin staining provides a simple, specific and sensitive method for identifying corneal epithelial cells. Further characterization of the keratins synthesized by corneal epithelial cells under various in vivo and in vitro conditions may provide useful information concerning the mechanisms of corneal epithelial differentiation.
Data complexity assessment in undersampled classification of high-dimensional biomedical data

Regularized linear classifiers have been successfully applied in undersampled, i.e. small sample size/high dimensionality biomedical classification problems. Additionally, a design of data complexity measures was proposed in order to assess the competence of a classifier in a particular context. Our work was motivated by the analysis of ill-posed regression problems by Elden and the interpretation of linear discriminant analysis as a mean square error classifier. Using Singular Value Decomposition analysis, we define a discriminatory power spectrum and show that it provides useful means of data complexity assessment for undersampled classification problems. In five real-life biomedical data sets of increasing difficulty we demonstrate how the data complexity of a classification problem can be related to the performance of regularized linear classifiers. We show that the concentration of the discriminatory power manifested in the discriminatory power spectrum is a deciding factor for the success of the regularized linear classifiers in undersampled classification problems. As a practical outcome of our work, the proposed data complexity assessment may facilitate the choice of a classifier for a given undersampled problem.
Spatially Ordered Dynamics of the Bacterial Carbon Fixation Machinery

Cyanobacterial carbon fixation is a major component of the global carbon cycle. This process requires the carboxysome, an organelle-like proteinaceous microcompartment that sequesters the enzymes of carbon fixation from the cytoplasm. Here, fluorescently tagged carboxysomes were found to be spatially ordered in a linear fashion. As a consequence, cells undergoing division evenly segregated carboxysomes in a nonrandom process. Mutation of the cytoskeletal protein ParA specifically disrupted carboxysome order, promoted random carboxysome segregation during cell division, and impaired carbon fixation after disparate partitioning. Thus, cyanobacteria use the cytoskeleton to control the spatial arrangement of carboxysomes and to optimize the metabolic process of carbon fixation.
Equality of length-form and velocity-form transition amplitudes in relativistic many-body perturbation theory

Rules for obtaining transition amplitudes that are equal in length form and velocity form, order-by-order in relativistic many-body perturbation theory are presented. Explicit formulas are derived for first-, second-, and third-order amplitudes for transitions between valence states in alkali-metal atoms. Numerical codes are developed to evaluate amplitudes through third order and applied to $3s\ensuremath{-}{3p}_{1/2}$ and $3s\ensuremath{-}{3p}_{3/2}$ transitions in sodium and sodiumlike ions. The present calculations for sodiumlike ions are compared with other accurate theoretical calculations.
Constraint weighting and constraint domination : a formal comparison*

The advent of Optimality Theory has revived the interest in articulatorily and perceptually driven markedness in phonological research. To some researchers, the cross-linguistic prevalence of such markedness relations is indication that synchronic phonological grammar should include phonetic details. However, there are at least two distinct ways in which phonetics can be incorporated in an optimality-theoretic grammar: traditional constraint domination and Flemming (2001) 's proposal that the costs of constraint violations should be weighted and summed. I argue that constraint weighting is unnecessary as an innovation in Optimality Theory. The arguments are twofold. First, using constraint families with intrinsic rankings, constraint domination formally predicts the same range of phonological realisations as constraint weighting. Second, with proper constraint definitions and rankings, both the additive effect and the locus effect predicted by constraint weighting can be replicated in constraint domination.
The Evolution of Comparative or Competitive Advantage: A Preliminary Report on a Study

This paper is a preliminary report on a study of the comparative evolution of several major high tech industries in the US, Japan and Western Europe. In general the paper examines similarities and differences in the ways these industries developed in different countries, and the factors explaining those differences. The project especially focused on understanding the instances when firms in a particular country gained a strong competitive advantage over firms based in other countries. The industries studied are: organic chemical products, computers, semiconductors, software, numerical controlled machine tools, pharmaceuticals in the age of biotechnology and medical devices. Copyright 1996 by Oxford University Press.
Kinetics of pressure-induced phase separation (PIPS) in polystyrene+methylcyclohexane solutions at high pressure

Abstract Kinetics of pressure-induced phase separation in polystyrene+methylcyclohexane solutions at high pressures (up to 25 MPa) have been studied as a function of polymer molecular weight (50 000 and 700 000), polymer concentration (in the range from 4 to 16% by mass) and the quench depth (in the range of 0.1–2 MPa), using time- and angle-resolved light scattering in a unique high-pressure cell with a path length of 250 μm. The results show that phase separation in solutions at critical polymer concentrations proceeds by spinodal decomposition which is displayed by a spinodal ring or a maximum in the scattered light intensities with angle. The time interval for the observation of spinodal ring was observed to depend on the quench depth. The ring collapse was observed to take place within the range of 3–160 s, shorter times being associated with deeper quenches. Phase separation in solutions at off-critical concentrations was observed to proceeded by nucleation and growth mechanism for shallow quenches (as reflected by the absence of a maximum in the angular variation of the scattered light intensities), but by the spinodal decomposition process for deep quenches. The characteristic wave number q m corresponding to the maximum scattered light intensity I m was observed to be non-stationary and moved to lower wave numbers with time for all quenches leading to spinodal decomposition. The time evolution of q m and I m were observed to obey the power law approximations q m ∼ t − α and I m ∼ t β . The exponents α and β were found to increase with the quench depth, while however, maintaining a β ≅2 α relationship. The scaling characteristics of the structure factor were also analyzed. It was found that for a given quench depth the data at different times could be reduced to a single master curve when normalized with respect to the maximum in the scattered light intensity and the corresponding wave number. Calculations of the apparent diffusivity, based on the estimated values for the early stage characteristic wave number q m0 , gave values around 10 −9 cm 2 /s.
The distribution and significance of Richelia intracellularis Schmidt in the North Pacific Central Gyre1

Localized blooms of phytoplankton observed in the upper 60 m of the North Pacific Central Gyre during three expeditions are accompanied and often dominated by an increase in the abundance of species of the diatom genus Rhizosolenia that contain the endophytic cyanophyte Richelia intracellularis, which may fix molecular nitrogen. It is hypothesized that the phytoplankton blooms are stimulated and sustained by an increase in the available nitrogenous nutrients resulting from nitrogen fixation by Richelia.
Summer solstice solar radiation, the 100 kyr Ice Age cycle, and the next Ice Age

Modeling studies suggest that the summer solstice solar radiation is more important than the caloric half-year solar radiation in producing glacial/interglacial cycles because it is more representative of the energy available to melt ice during the short melt season. Here it is shown that the correlation between the summer solstice solar radiation and the rate of change of the oxygen isotope record is generally greater than that between the caloric half-year radiation and the rate of change of the oxygen isotope record. These results also suggest that the sawtoothed nature of the 100 kyr cycle may be produced by periods of relatively slow changes in ice volume, punctuated by periods of rapid growth that are initiated at times of extremely low summer solstice radiation; and that it is unlikely that an ice age will begin in the next 70 kyr.
Conversion of canavanine to α-keto-γ-guanidinooxybutyrate and to vinylglyoxylate and 2-hydroxyguanidine

It was observed previously that hydroxyguanidine is formed in the reaction of canavanine(2-amino-4-guanidinooxybutanoate) with amino acid oxidases. The present work shows that hydroxyguanidine is formed by a nonenzymatic β,-γ-elimination reaction following enzymatic oxidation at the α-C and that the abstraction of the β-H is general-base catalyzed. The elimination reaction requires the presence in the α-position of an anion-stabilizing group—the protonated imino group (iminium ion group) or the carbonyl group. The iminium ion group is more activating than the carbonyl group. Elimination is further facilitated by protonation of the guanidinooxy group. The other product formed in the elimination reaction was identified as vinylglyoxylate (2-oxo-3-butenoate), a very highly electrophilic substance. The product resulting from hydrolysis following oxidation was identified as α-keto-γ-guanidinooxybutyrate (ketocanavanine). The ratio of hydroxyguanidine to ketocanavanine depended upon the concentration and degree of basicity of the basic catalyst and on pH. In the presence of semicarbazide, the elimination reaction was prevented because the imino group in the semicarbazone derivative of ketocanavanine is not significantly protonated. Incubation of canavanine with 5′-deoxypyridoxal also yielded hydroxyguanidine. Since the elimination reactions take place under mild conditions, they may occur in vivo following oxidation at the α-C of l-canavanine (ingested or formed endogenously) or of other amino acids with a good leaving group in the γ-position (e.g., S-adenosylmethionine, methionine sulfoximine, homocyst(e)ine, or cysteine-homocysteine mixed disulfide) by an l-amino acid oxidase, a transaminase, or a dehydrogenase. Therefore, vinylglyoxylate may be a normal metabolite in mammals which at elevated concentrations may contribute to the in vivo toxicity of canavanine and of some of the other above-mentioned amino acids.
Quinine-induced thrombocytopenic purpura due to an IgM and an IgG antibody.

Severe thrombocytopenia developed in a young man following the ingestion of quinine water. Quinine-dependent antiplatelet antibodies were found in both IgM and IgG components of the patient's immunoglobulins. The data demonstrate that drug-related antiplatelet activity is not a unique property of 7 S gamma globulins, and that both IgM and IgG antibodies may occur simultaneously in drug-related thrombocytopenia.
Functional properties of ryanodine receptors from rat dorsal root ganglia

The properties of ryanodine receptors (RyRs) from rat dorsal root ganglia (DRGs) have been studied. The density of RyRs (Bmax) determined by [3H]ryanodine binding was 63 fmol/mg protein with a dissociation constant (Kd) of 1.5 nM. [3H]Ryanodine binding increased with caffeine, decreased with ruthenium red and tetracaine, and was insensitive to millimolar concentrations of Mg2+ or Ca2+. DRG RyRs reconstituted in planar lipid bilayers were Ca2+-dependent and displayed the classical long-lived subconductance state in response to ryanodine; however, unlike cardiac and skeletal RyRs, they lacked Ca2+-dependent inactivation. Antibodies against RyR3, but not against RyR1 or RyR2, detected DRG RyRs. Thus, DRG RyRs are immunologically related to RyR3, but their lack of divalent cation inhibition is unique among RyR subtypes.
A priori bounds for solutions to nonlinear two-point boundary value problems

The boundary value problem is considered. The function f is assumed to be continuous on [a, b]× R2, and g 1 and g 2 are assumed to be continuous and nondecreasing on R. The condition (A)There exists M 1 >0 and a positive, continuous function Ψ(p) defined on [0, ∞) such that and for , is used to obtain an a priori bound on solutions, As applications of the a priori bound, an existence theorem is obtained using the Leray-Schauder Theorem, and a “weak continuous dependence theorem” is proved, In both cases, the well-known Nagumo condition is also imposed in order to obtain a priori bounds on derivatives of solutions.
The RET–Glial Cell-derived Neurotrophic Factor (GDNF) Pathway Stimulates Migration and Chemoattraction of Epithelial Cells

Embryonic development requires cell migration in response to positional cues. Yet, how groups of cells recognize and translate positional information into morphogenetic movement remains poorly understood. In the developing kidney, the ureteric bud epithelium grows from the nephric duct towards a group of posterior intermediate mesodermal cells, the metanephric mesenchyme, and induces the formation of the adult kidney. The secreted protein GDNF and its receptor RET are required for ureteric bud outgrowth and subsequent branching. However, it is unclear whether the GDNF–RET pathway regulates cell migration, proliferation, survival, or chemotaxis. In this report, we have used the MDCK renal epithelial cell line to show that activation of the RET pathway results in increased cell motility, dissociation of cell adhesion, and the migration towards a localized source of GDNF. Cellular responses to RET activation include the formation of lamellipodia, filopodia, and reorganization of the actin cytoskeleton. These data demonstrate that GDNF is a chemoattractant for RET-expressing epithelial cells and thus account for the developmental defects observed in RET and GDNF mutant mice. Furthermore, the RET-transfected MDCK cells described in this report are a promising model for delineating RET signaling pathways in the renal epithelial cell lineage.
New subfamily Proschizophoriinae of dalmanellid Brachiopds

Proschizophoria Maillieux is restudied and found to be related to the Silurian genusIdiorthis McLearn and a new genusCordatomyonia, type speciesCordatomyonia shupei, n. sp.Proschizophoria, Idiorthis, andCordatomyonia are united in the new subfamily Proschizophoriinae which is assigned to the dalmanellid family Rhipidomellidae. Rhipidomellidae and its included subfamilies Heterorthinae, Rhipidomellinae, and Proschizophoriinae are emended and newly diagnosed. A new dalmanellid genus,Megasalopina, is proposed for the Lower Devonian species“Dalmanella” elevata Williams & Breger and its allies. It is thought to have been derived from the draboviinid genusSalopina Boucot and therefore belongs to the Schizophoriidae.Dalmanellopsis Khalfin is removed from the synonymy ofLevenea and is shown to be related toSalopina.
Why K? High order singularities and small scale yielding

Singular terms in the crack tip elastic stress field of order σ ∼ r-3/2, r-5/2, ... are often neglected, thus rationalizing the use of the K field, σ ∼ r-1/2, as the dominant term for fracture mechanics. We find the common explanation for neglecting the more singular terms in the series solution for the crack tip stress field unsatisfying. Further, the more singular terms are non-zero and are needed to understand the energetics of fracture, i.e., J and {ie97-1}. Given that the singular terms are generally present, the rationale for the validity of the small scale yielding assumption (the basis of linear elastic fracture) is more subtle than any argument which depends on the elimination of terms with stress σ ∼ r-3/2, r-5/2, ... Our explanation for the validity of small scale yielding is as follows. First, with or without small scale yielding, the stress field outside of the nonlinear zone does contain more singular terms. In the limit as the nonlinear zone at the crack tip shrinks to zero size (SSY) we show that the r-1/2 term in the Williams expansion dominates both the more singular and the non-singular terms in an annular region somewhat removed from this zone. Further, in this limit the magnitude of the σ ∼ r-1/2 term is almost entirely determined by tractions on the outer boundary. Our theory and examples are for representative problems in mode III anti-plane shear fracture. We expect, however, that the general results also apply to mode I and mode II fracture.
Molecular distribution of some commercial nonylphenol ethoxylates using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Nonylphenol ethoxylates (NPEs) belong to a group of nonionic surfactants that are collectively referred to as alkylphenol ethoxylates (APEs). APEs find widespread use in heavy-duty commercial and household cleaning formulations, shampoos, and industrial processing, i.e. textile manufacture. Their environmental impact depends on the molecular distribution and the extent of their biodegradation in municipal sewage systems, waterways and rivers. We have established two sample preparation methods that have enabled the determination of the molecular distributions of six commercial nonylphenol ethoxylates using matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS). In both methods, alpha-cyano-4-hydroxycinnamic acid, dissolved in acetonitrile/tetrahydrofuran, was used as the matrix. In one set of experiments, the NPEs were dissolved in an acetonitrile/tetrahydrofuran solvent system prior to mixing with the matrix solution, and the resulting MALDI-TOF mass spectra produced mostly sodiated molecules [M + Na](+). The NPEs, all having the formula 4-(C(9)H(19))-C(6)H(4)-(OCH(2)CH(2))(n)-OH, are Surfonic (R)N-95, N-100, N-102, N-120, N-150 and N-300. Surfonic N-95 and N-100 gave n values of 5-20; Surfonic N-102, N-120, N-150, and N-300 gave n values of 5-21, 5-22, 8-25 and 15-40, respectively. In order to develop a sample preparation method that could be used with less polar NPEs, we dissolved the NPEs (except N-300) in pentane prior to mixing with the matrix solution, and found that the MALDI spectral quality was unaffected by the solvent systems. Copyright 1999 John Wiley & Sons, Ltd.
Using Measurements of the ion Current Through a Synthetic Nanopore to Discriminate Nucleotides in a Single DNA Molecule

Sequencing DNA with a nanopore relies on a distinctive electrical signal associated with each nucleobase that develops when a single DNA molecule, immersed in electrolyte, translocates across a membrane through the pore. We show that it is possible to discriminate nucleobases in DNA through measurements of the electrolytic current through a synthetic nanopore. We use a pore smaller in diameter than the double helix, in a silicon nitride membrane 15 nm thick. When an electric field is applied, biotinylated DNA homopolymers bound to streptavidin are impelled into and through the pore, but prevented from full translocation by the large streptavidin molecule at one end. Subsequent long time measurements of the blockade current through the pore reveal distinctive electrical signatures for poly (dA), poly (dC), and poly (dT) on a scale >100pA at high voltage (>100mV); differences much larger than the ∼pA-level currents used to discriminate nucleotides in proteinaceous pores like α-hemolysin.
Women seeking second opinion for symptomatic uterine leiomyoma: role of comprehensive fibroid center

The objective of the study was to describe our early experience with a comprehensive uterine fibroid center and report our results in women seeking a second opinion for management of symptomatic uterine leiomyoma. We performed a HIPAA-complaint, IRB-approved retrospective study of women seeking second opinion for management of uterine fibroids at our multidisciplinary fibroid treatment center in a tertiary care facility from July 2008 to August 2011. After a review of patients’ history, physical examination, and magnetic resonance imaging (MRI) findings, treatment options were discussed which included conservative management, uterine-preserving options, and hysterectomy. We performed Fisher’s exact test for categorical variables between the cohort that did or did not undergo a uterine-preserving treatment. Differences were considered significant at p < 0.05. The mean age of the 205 patient study cohort was 43.8 years (SD 7.5). One hundred sixty-two (79.0%) patients had no prior therapy. Based on MRI, one or more fibroids were detected in 178/205 (86.8%), adenomyosis in 8/205 (3.9%), and a combination of fibroid and nonfibroid condition (i.e., adenomyosis, endometrial polyp) in 18/205 (8.8%). In those who desired to transition their care to our institution (n = 109), 85 patients underwent 90 interventions: 39 MRgFUS (magnetic resonance-guided high-intensity focused ultrasound surgery), 14 UAE (uterine artery embolization), 25 myomectomies, 8 hysterectomies, 3 polypectomies, and 1 endometrial ablation. Five patients had two procedures. Intramural and subserosal fibroids were most commonly treated with MRgFUS followed by myomectomy and then UAE; in contrast, pedunculated fibroids were frequently managed with myomectomy. Multidisciplinary fibroid evaluation may facilitate the increase use of less invasive options over hysterectomy for symptomatic fibroid treatment.
Postoperative external beam radiotherapy for differentiated thyroid cancer: outcomes and morbidity with conformal treatment.

Purpose To review institutional outcomes for patients treated for differentiated thyroid cancer with postoperative conformal external beam radiotherapy (EBRT). Methods and Materials This is a single-institution retrospective review of 131 consecutive patients with differentiated thyroid cancer who underwent EBRT between January 1996 and December 2005. Histologic diagnoses included 104 papillary, 21 follicular, and six mixed papillary-follicular types. American Joint Committee on Cancer stage distribution was Stage III in 2 patients, Stage IVa–IVc in 128, and not assessable in 1. Thirty-four patients (26%) had high-risk histologic types and 76 (58%) had recurrent disease. Extraglandular disease spread was seen in 126 patients (96%), microscopically positive surgical margins were seen in 62 patients (47%), and gross residual disease was seen in 15 patients (11%). Median EBRT dose was 60 Gy (range, 38–72 Gy). Fifty-seven patients (44%) were treated with intensity-modulated radiotherapy (IMRT) to a median dose of 60 Gy (range, 56–66 Gy). Median follow-up was 38 months (range, 0–134 months). Results Kaplan-Meier estimates of locoregional relapse-free survival, disease-specific survival, and overall survival at 4 years were 79%, 76%, and 73%, respectively. On multivariate analysis, high-risk histologic features and gross residual disease predicted for inferior locoregional relapse-free survival, whereas high-risk histologic features, M1 disease, and gross residual disease predicted for inferior disease-specific and overall survival. The IMRT did not impact on survival outcomes, but was associated with less frequent severe late morbidity (12% vs. 2%). Conclusions Postoperative conformal EBRT provides durable locoregional disease control for patients with high-risk differentiated thyroid cancer if disease is reduced to microscopic burden. Patients with gross disease face significantly worse outcomes. The IMRT may significantly reduce chronic radiation morbidity, but requires additional study.
Is it appropriate to use core clerkship grades in the selection of residents

Objective This study challenges the appropriateness of using core clerkship grades for resident selection. The authors hypothesize that substantial variability occurred in the system of grading. Design In this retrospective cross-sectional study, variability in the grading systems for third-year core clinical clerkships were examined. From the Medical Student Performance Evaluation of applicants from U.S. medical schools for residency training in the authors’ department in 2004 and 2005, the authors gathered the following variables: medical school, third-year core clerkship grading systems, and percentage of students in each grade category. Descriptive analyses were conducted and within institution variability across clerkship scores was analyzed using repeated measure analysis of variance (ANOVA) and t-test. Setting University teaching hospital. Participants The survey covered 121 of 122 U.S. medical schools accredited by the AAMC/LCME. Results Grading systems used included: variations of Honors/Pass/Fail (H,P,F) system in 76 schools, letter grade systems in 22 schools, and other variants (eg, Outstanding, Advanced, and Proficient in 6 schools and Pass/Fail in 4 schools). Thirteen schools (10%) provided either no grading system or no interpretable system. Grading systems included were further defined into 2 scores in 6 schools, 3 in 34 schools, 4 in 38 schools, 5 in 23 schools, and more than 6 in 6 schools. For schools using a grading system containing 3 or more scores, the percentage of students given the highest grade was significantly less in Surgery (28%) compared with Family Medicine (34%) and Psychiatry (35%) (p = 0.001). Conclusions Core clerkship grading systems and the percentage to which institutions grade students as having achieved the highest performance level vary greatly among U.S. medical schools. Within institutions, significant variability exists among clerkships in the percentage of the highest grade given, which makes interpersonal comparison based on core clerkship grades difficult and suggests that this method may not be a reliable indicator of performance.
Inhibition of tumor growth in a human neuroblastoma xenograft model with TNP-470

Background and Procedure High-risk neuroblastoma disease features are correlated with tumor vascularity, suggesting that angiogenesis inhibitors may be a useful addition to current therapeutic strategies. We therefore examined the efficacy of TNP-470 (TAP Pharmaceuticals, Deerfield, IL) in human neuroblastoma xenograft models. Results Tumor growth rate was markedly inhibited in mice receiving TNP-470 administered alone with a treatment to control ratio (T/C) at day 21 = 0.4 (P < .001). TNP-470 also significantly inhibited tumorigenicity when administered shortly after xenograft inoculation (T/C at day 30 = 0.1, P < .001) and when administered following cyclophosphamide (T/C at day 35 = 0.1, P < .001). Conclusions These data show that TNP-470 is a potent inhibitor of human neuroblastoma growth both alone and when given with conventional chemotherapy, suggesting that it may be a useful adjunctive therapy for high-risk neuroblastoma patients. Med. Pediatr. Oncol. 35:673–676, 2000. © 2000 Wiley-Liss, Inc.
Sodium homeostasis in infants with biliary drainage procedures.

• We studied biliary excretion of sodium and chloride in 17 infants with external bile drainage through a "biliostomy" and describe four additional children who became ill from sodium depletion following external biliary drainage procedures for biliary tract anomalies. In the 17 infants, the mean ± SD bile sodium concentration was 122±15 mEq/L. The mean±SD serum sodium concentration was low (132±7 mEq/L) (normal, 138 to 145 mEq/L). The mean±SD bile volume was 388 ±317 mL/day at one year following surgery (range, 40 to 1,000 mL/day). In the four children, clinical manifestations of sodium depletion (lethargy, anorexia, dehydration, and malnutrition) necessitated hospital admission. At that time, the serum sodium concentration ranged from 109 to 129 mEq/L, and the simultaneous urinary sodium concentration ranged from 0 to 5 mEq/L. Although dietary sodium was normal, biliary losses exceeded dietary intake, resulting in salt and water depletion despite renal conservation. Children with biliary drainage procedures are at risk for sodium depletion and should be monitored closely and supplemented accordingly until biliostomy closure is performed. (AJDC1986;140:535-538)