cssi/SciSciGPT-SciSciNet huggingface dataset:
Genetic relationships between native and introduced populations of the little fire ant Wasmannia auropunctata

Native to much of Central and South America, the little fire ant Wasmannia auropunctata has been rapidly spreading throughout the world. In its introduced range, W. auropunctata is frequently linked with drastic reductions of ant diversity; anecdotal reports of damaging attacks on vertebrates are also common. As it poses an ever-increasing threat to biodiversity, W. auropunctata has emerged as a model system for the study of ecological differences between native and invasive ant populations. These studies have been hampered by a lack of information on the genetic relatedness between native and introduced populations. By investigating the genetic structure of W. auropunctata populations, we provide a framework for conducting phylogenetically independent tests of differences between these ants in their native and invasive ranges. Phylogenetic analyses, based on the cox1 / cox2 region of mtDNA, revealed at least three separate source populations of W. auropunctata distributed across two large clades. Much of the Caribbean region, presumably part of the native range, is inhabited by a clade of ants sharing very similar or identical mtDNA haplotypes, suggesting the possibility of multiple introductions or high levels of gene flow across that area. Most invasive populations in the Pacific were closely related to these ants. The invasive populations in Gabon and New Caledonia arise from another, relatively distantly related clade. Phylogenetically independent contrasts confirm McGlynn’s (1999) observation that invasive W. auropunctata populations are smaller than native populations. Given the complex phylogeographical structure of W. auropunctata populations, future comparative work should correct for phylogenetic effects.
Gastric mucosal blood flow following damage by ethanol, acetic acid, or aspirin.

The gastric mucosal blood flow in vagally denervated oxyntic gland area (Heidenhain) pouches was estimated by aminopyrine clearance in four 30-min periods after irrigations with acid solutions of ethanol, acetic acid, and aspirin. Mucosal blood flow increased initially when either ethanol or acetic acid was used and subsequently declined with appearance of evidence of gastric mucosal barrier damage. In spite of similar evidence for gastric mucosal barrier damage the mucosal blood flow with the aspirin solutions was, by the fourth period, significantly greater than the mucosal blood flow with the acetic acid solutions. Studies with acetic acid and aspirin solutions were repeated in vagally innervated oxyntic gland area (Pavlov) pouches. The pattern of mucosal blood flow was similar and in those experiments with homogeneous base lines the mucosal blood flow of the aspirin studies in the fourth period was again significantly greater than that of the acetic acid study. Although a greater mucosal blood flow might be considered a beneficial and protective influence, invariable bleeding characterized the fourth period of the aspirin experiments while only inconstant and minimal bleeding was noted in the fourth period of the acetic acid experiments.
Application of recategorized WISC-R scores for adjudicated adolescents.

Bannatyne's recategorization of WISC-R scores was applied to 97 juveniles who had been adjudicated by the juvenile court system to a diagnostic and evaluation unit in Eastern Alabama. Mean ranks werre analyzed using the Friedman test for repeated-measures analysis of variance. The total sample exhibited a significant mean rank pattern of scores in the following descending order: Spatial, Conceptual, Sequential, and Acquired Knowledge. Subgroup patterns varied for those youths with IQs 90 and above (Conceptual, Spatial, Sequential, and Acquired Knowledge) and IQs below 90 (Spatial, Sequential, Conceptual, and Acquired Knowledge). Pairwise comparisons using the Scheffe procedure indicated significant differences between the Spatial score and Acquired Knowledge score for the total group and those youths with IQs below 90. The study extended the application of recategorized scores for adjudicated youth suggested by Bannatyne (1968, 1971, 1974). This investigation affirms the need for further studies of the differential effect of IQ on the patterns of WISC-R scaled scores.
Modeling fracture in the context of a strain-limiting theory of elasticity: a single anti-plane shear crack

This paper is the first part of an extended program to develop a theory of fracture in the context of strain-limiting theories of elasticity. This program exploits a novel approach to modeling the mechanical response of elastic, that is non-dissipative, materials through implicit constitutive relations. The particular class of models studied here can also be viewed as arising from an explicit theory in which the displacement gradient is specified to be a nonlinear function of stress. This modeling construct generalizes the classical Cauchy and Green theories of elasticity which are included as special cases. It was conjectured that special forms of these implicit theories that limit strains to physically realistic maximum levels even for arbitrarily large stresses would be ideal for modeling fracture by offering a modeling paradigm that avoids the crack-tip strain singularities characteristic of classical fracture theories. The simplest fracture setting in which to explore this conjecture is anti-plane shear. It is demonstrated herein that for a specific choice of strain-limiting elasticity theory, crack-tip strains do indeed remain bounded. Moreover, the theory predicts a bounded stress field in the neighborhood of a crack-tip and a cusp-shaped opening displacement. The results confirm the conjecture that use of a strain limiting explicit theory in which the displacement gradient is given as a function of stress for modeling the bulk constitutive behavior obviates the necessity of introducing ad hoc modeling constructs such as crack-tip cohesive or process zones in order to correct the unphysical stress and strain singularities predicted by classical linear elastic fracture mechanics.
First Report of Xanthomonas Leaf Blight of Onion in California.

In 2000 and 2001, severe leaf blight of fresh market onions occurred in several fields in the Antelope Valley of California, a high desert area located in northern Los Angeles County. In at least two fields, 70% of the canopy was affected, which resulted in an estimated yield reduction of over 50%. Both organically and conventionally grown onions were affected. Symptoms included numerous small chlorotic lesions that appeared first on older leaves. Lesions were often surrounded by water-soaked margins. As the season progressed, the lesions became elongated and necrotic. Entire leaf blades were often killed. The disease never progressed into the bulbs, but bulbs of infected plants never grew to full size. Yellow mucoid bacterial colonies were recovered on yeast extractdextrose-CaCO3 agar from symptomatic tissue. All isolates were gram-negative rods with single polar flagella. Two representative isolates were identified as Xanthomonas campestris based on their carbon utilization profile (similarity index of 0.784 and 0.850; Biolog, Hayward, CA), fatty acid profile (similarity index of 0.588; MIS-TSBA, version 4.10, MIDI Inc., Newark, DE), and 16S-23S intergenic spacer DNA sequences (98% sequence identify with strains of X. campestris). In greenhouse pathogenicity tests, eight white globe onion plants were inoculated with a bacterial suspension (106 CFU/ml) of each of the two isolates. Plants were inoculated by spraying the suspension on leaves lightly injured by rubbing with Carborundum or puncturing with needles dipped in the suspension. Controls were inoculated with water. All plants inoculated with the bacteria developed symptoms in 6 days. The bacterium was reisolated from all inoculated plants and confirmed as Xanthomonas. The trial was conducted twice. To our knowledge, this is the first report of Xanthomonas leaf blight of onion in California. In the United States, the disease has been reported in Texas and Colorado (1,2). References: 1. T. Isakeit et al. Plant Dis. 84:201, 2000. 2. H. F. Schwartz and K. Otto. Plant Dis. 84:922, 2000.
Implementing monetary base rules: The currency problem

Abstract Monetary policy rules which rely on the monetary base have been advocated by Meltzer and McCallum. Proponents claim that following monetary base rules would minimize fluctuations around the target growth rate for nominal GNP. Critics of such rules contend that currency has not been properly accounted for in their analysis. This paper examines McCallum's monetary base rule by explicitly taking the demand for currency into account. Assuming that currency is supplied elastically, our investigation quantifies changes in the composition of the monetary base under these rules and provides an estimate of how these compositional changes might affect the variability around the target nominal GNP growth rate.
Comparison of varicella history with presence of varicella antibody in refugees.

Abstract Objective : To compare history of varicella with presence of varicella antibody in refugees and to determine the number of unnecessary doses of varicella vaccine administered to refugee children ≥7 years of age. Methods : Cross-sectional study of refugees ≥7 years of age evaluated between July 2000 and October 2002 by the Refugee Health Assessment Program at Boston Medical Center. We recorded age, sex, region of origin, varicella history, and results of serologic testing for presence of varicella antibodies. Results : Eighty-eight percent of individuals with a positive history of clinical varicella had varicella antibody; 65% of those with negative history had varicella antibody. The positive predictive value of a history of clinical varicella was 88%. The negative predictive value of a negative history was 39%. Conclusion : History of varicella was not a reliable predictor of presence or absence of varicella antibody in refugees. Strategies to protect individuals with negative histories of clinical varicella include immediate immunization or serotesting followed by immunization of susceptible individuals. Relying on positive histories of clinical varicella may leave some individuals susceptible to varicella and impede efforts to eliminate varicella in the US.
COPPER BENZOCHLORIN, A NOVEL PHOTOSENSITIZER FOR PHOTODYNAMIC THERAPY: EFFECTS ON A TRANSPLANTABLE UROTHELIAL TUMOR

An iminium salt of octaethylbenzochlorin with copper in the aromatic ring, CDS1, was tested for its tumoricidal effects on the AY-27 N-[4-(5-nitro-2-furyl)-2-thiazolyl] formamide tumor line. CDS1 was found to be an effective photosensitizer in vivo when used in combination with either a xenon arc lamp or a pulsed alexandrite laser. Hemodynamically, CDS1 and light caused a rapid decrease in tumor blood flow. Skin photosensitization was found to be minimal when drug-injected mice were illuminated in a solar simulator.
Response to comment on Hedderson et al. Prepregnancy SHBG concentrations and risk for subsequently developing gestational diabetes mellitus. Diabetes Care 2014;37:1296-1303.

We appreciate the comment by Stefan et al. (1) on our recent article (2). We agree that HOMA-IR is not the ideal method to assess insulin resistance and a more dynamic test, e.g., a frequently sampled 75-g oral glucose tolerance test, would have been more precise. Without this more accurate assessment, it is difficult to …
Functional and spectroscopic characterization of half-liganded iron-zinc hybrid hemoglobin: evidence for conformational plasticity within the T state.

Functionally distinct conformations of HbA (human adult hemoglobin) were probed using deoxy and diliganded derivatives of symmetric Fe−Zn hybrids of HbA. To expand the range of accessible structures, different environments were utilized including solution, sol−gel encapsulation, and crystals. Further structural and functional modulation was achieved by the addition of allosteric effectors. Functional characterization included oxygen affinity measurements, CO combination rates, and geminate and bimolecular CO recombination, after photodissociation. The conformational properties were studied using visible resonance Raman spectroscopy as a probe of local tertiary structure at the iron-containing hemes and UV resonance Raman spectroscopy as a probe of elements of the globin known to be sensitive to quaternary structure. The combined results show a pattern in which there is a progression of conformational and functional properties that are consistent with a picture in which the T quaternary structure can accom...
Multiphoton-Excited Fluorescence Imaging and Photochemical Modification of Dye-Doped Polystyrene Microsphere Arrays

The use of nonlinear optical methods for thin-film polymeric materials modification and characterization is explored. Ordered 3-dimensional (3-D) dye-doped polystyrene microsphere arrays are photobleached and imaged in these studies. Efficient, irreversible photochemical bleaching of the dye within individual 0.5 and 1 μm diameter microspheres occurs when 810 nm light from a mode-locked Ti:sapphire laser is focused to an ∼400 nm diameter spot within the spheres. Photobleaching is shown to result from three-photon absorption and may involve ionization of the dye. The three-photon-induced photochemistry is dramatically more efficient than that resulting from single-photon excitation. Imaging of the unbleached and bleached arrays is accomplished by monitoring the two-photon-excited fluorescence from the dye. Both the nonlinear photobleaching and imaging methods provide inherent depth-discriminating capabilities, allowing for high-resolution 3-D control of the volume modified and imaged. The results suggest t...
Reconfiguration of hexagonal arrays by diagonal deletion

Abstract This paper describes various algorithms for dynamic reconfiguration of VLSI hexagonal arrays. These algorithms are applicable to arrays in which reconfiguration requires logical deletion of the diagonal front of computation. Initially it is proven that the intuitive, but rather naive approach of diagonal deletion is not correct, because it does guarantee the generation of the correct dimensions in the target array. A new approach based on geometrical considerations is proposed. Theorems that preserve the dimensions of the desired target array, are presented. Two reconfiguration algorithms are presented. These algorithms have linear time-complexity with respect to the dimensions of the array. The innovative features of this approach are the dependence of reconfiguration on the dimensions of the array to be reconfigured and a better exploitation of redundancy for run-time reconfiguration. Simple switching circuits are described. It is proved that silicon overhead consists of four two-by-two Banyan switches per cell. Illustrative examples are presented.
Epileptic psychiatric patients, a special population

In order to characterize the diagnostic and treatment problems posed by psychiatric patients who are also suffering from epilepsy, a retrospective chart review was performed. The medical records of 43 consecutive psychiatric inpatients with diagnosis of epilepsy and 43 sex and age matched psychiatric inpatients without epilepsy were reviewed. The diagnosis of epilepsy strongly influenced both the diagnosis and management of these patients. Epileptic patients were more likely to be diagnosed as suffering from an organic mental disorder (p.<01) and to receive anticonvulsant medications (88%). A number of significant problems were apparent. Clinical information necessary to make the above diagnostic and therapeutic decisions was often lacking. Frequently, the history of epilepsy or even evidence that one existed was not documented. We conclude that disseminating knowledge about the psychiatric aspects of epilepsy, as well as a closer working relationship between the different clinicians treating the patient,...
Nuclear matter calculations with mean scalar fields

Abstract We examine the possibility that nuclear-matter binding energy comes from the coupling of nucleons to a mean scalar field; vector fields are simulated by Yukawa potentials. It is found that the mean Schwinger σ field cannot explain the normal nuclear-matter saturation for any values of the coupling constants, while a simple scalar field with only quadratic terms is permitted.
Remenants of Things Past: Memory and the Knight's Tale

AbstractChaucer's Knight's Tale uses medieval memory theory and the practice of mnemonics to suggest the inescapability of trauma for chivalric subjects racked by violent, compulsive remembering. The Tale explores the burdensome chivalric requirement that living knights remember their dead companions, set out by Theseus in his Boethian First Mover speech. Examining Chaucer's philosophical reworking of Boethian conceptions of memory in the Boece illuminates the poet's understanding of the function of human memory and its resonance in the opening of the Canterbury Tales. The memorial onus of this obligation, figured in both the Knight narrator's Tale and in his telling of it, marks a mournful ambivalent desire to remember lost friends and to forget traumatic memorial images of death and violence; the Knight narrator alternately expands and contracts the remnant of his Tale.
Online Closed-Loop Autotuning Digital Controller for Switching Power Converters

A switching power-converter closed-loop online autotuning controller is presented in this paper. The presented controller is based on tuning the closed-loop-compensator parameters by simply observing the compensated-error-signal time-domain characteristics. Moreover, the presented online autotuning controller does not require the knowledge of the power-stage frequency response, does not depend on any conventional rule-of-thumb control-design criteria such as gain and phase margins, can be used without interrupting the normal operation of the power converter, and is relatively simple when compared to other methods particularly those that require measuring the frequency response of the power stage or closed-loop converter system. The online autotuning controller is presented in this paper based on a dc-dc buck switching converter with a fully digital closed-loop controller, as an example and not for limitation.
Display advertising’s competitive spillovers to consumer search

We find display advertising influences customer search for both the advertised brand and its competitors. We exploit a natural experiment that randomizes ad delivery on 500 million visits to the Yahoo! homepage and compare visitors’ subsequent activities on Yahoo! Search. In three advertisers’ campaigns, display ads increase searches for advertised brands by 30–45 % and for competitors’ brands by up to 23 %. Strikingly, the total number of incremental searches for competitors is 2–8 times the increase for advertisers’ brands. We discuss how these spillovers create strategic complementarities for search advertisers and reduce firms’ investments in advertising.
A generalized 'adaptive expectations' formula in auto-regressive models

In the model of this paper the state of the system follows a linear auto-regressive process and is observed with noise. The decision-maker's problem is to estimate the current state: with a payoff function quadratic in the decision variables the optimal estimator is the conditional mean, given the observations. With the use of the Kalman filter results of interest to economists are obtained. The basic result is that the optimal estimate is a convex linear combination of the current observation and the previous optimal estimate. This is a generalization of the 'adaptive expectations' formula widely used in economics.
Induced metal-ion exchange in excavated human bone

Excavated human bone was exposed to aqueous solutions containing high concentrations of a single added metal ion in order to examine the extent of introduction of contaminating materials during burial. Variables included pH, temperature, ion concentration, state of bone (whole or crushed), structure of buffer, and counterion. Calcium and sodium showed little increase, and even a decrease in some cases. Strontium, zinc, lead, and magnesium showed large increases probably through heteroionic replacement of calcium. Manganese, aluminum, and potassium showed increases, particularly under neutral conditions, probably through infiltration into voids and defects.
Source of Iron for Sulfidation and Gold Deposition, Twin Creeks Carlin-Type Deposit, Nevada

This study was undertaken to determine the source of iron in Comus Formation sedimentary rocks that were sulfidized during deposition of gold in the Megapit area of the Twin Creeks Carlin-type deposit. Sedimentary rocks in and near the Megapit contain ferroan dolomite, largely as overgrowths on iron-poor dolomite. Iron to form these overgrowths appears to have been released from mafic volcanic rocks that are interlayered with the sedimentary rocks. These igneous rocks have undergone two stages of hydrothermal alteration. The first stage involved formation of albite and iron-rich chlorite, possibly caused by interaction with seawater. The second stage involved destruction of the iron-rich chlorite by illite or sericite, which released iron to form ferroan dolomite in the sedimentary rocks. Comparisons show that transfer of iron from the igneous rocks to the sedimentary rocks can account for the present distributions of iron in these rocks. Relative to basalts, Comus Formation igneous rocks are enriched in iron and potassium. These results suggest that ferroan dolomite in sedimentary rocks is not solely a product of diagenetic processes and can form when iron is released from adjacent iron-bearing igneous rocks. Recognition of this additional mechanism for formation of ferroan dolomite expands the range of geologic settings that can be favorable for formation of gold deposits formed by sulfidation.
Stagewise Fractionation of Petroleum Pitches with Supercritical Toluene

A stagewise fractionation technique employing sequential single-stage extractions with supercritical toluene was used to fractionate the heaviest portion of an isotropic petroleum pitch. Each stage was operated in a region of liquid-liquid equilibrium (LLE) at a temperature of 614 K and a solvent-to-pitch ratio of 2.0, and the pressure was sequentially reduced so as to precipitate out ∼5 wt % of the feed pitch in each stage. Five single-stage flashes could be carried out in the LLE region at pressures ranging from 138 to 52 bar, and five pitch fractions comprising the heaviest 28. 8 wt % of the feed pitch were obtained. No flashes were performed below the onset of vapor-liquid equilibrium at 49 bar, because the vapor phase is a relatively poor solvent for pitches. Softening points, C/H ratios, and DRIFTS were all used to characterize the pitch fractions that were isolated. The heaviest three fractions had to be hydrogenated to increase their solubility in the mobile phase before molecular weight distributions could be determined by gel permeation chromatography. Results from the characterization techniques all indicate that stagewise fractionation is separating the pitch according to molecular weight.
Firing patterns of closer motoneurons during reflex activity in the dimorphic claws of the Lobster Homarus americanus

The in vivo firing patterns of the fast closer excitor (FCE) and slow closer excitor (SCE) motoneurons to the dimorphic claws of the lobster Homarus americanus were analyzed during reflex closure activity by identifying postsynaptic potentials in muscle fibers with known motor innervation. Three types of claw activity were observed: slow closure, rapid closure, and maintained closure. Slow closure and rapid closure in both claws were mediated by SCE and FCE, respectively. In the cutter, maintained closure was mediated only by SCE; in the crusher, both FCE and SCE could maintain closure. The homologous SCEs displayed no significant differences in activity; in both claws, they fired at medium-to-high frequency. The homologous FCEs did display different spike frequencies during claw closure. The crusher FCE fired at high frequencies; the cutter FCE fired at much lower frequencies. Such in vivo differences in axon activity between homologous FCEs are correlated with claw dimorphism and with the population of muscle fiber types.
Female goldfish signal spawning readiness by altering when and where they release a urinary pheromone

Although it is established that many species of fish release hormonally derived sex pheromones in their urine, whether these cues are unspecialized metabolic by-products or specialized communicatory signals is not known. Here, we addressed this question in the goldfish, Carassius auratus (a leading model of hormonal sex pheromone function) by conducting two experiments. We first monitored urine release by sexually receptive females that were placed with a sexually active male, an inactive male, another female, or no other fish. Sexual receptivity was induced using prostaglandin F2α, a hormone also known to evoke release of 15-keto prostaglandin F2α (15K-PGF2α), a potent urinary pheromone. We found that sexually receptive females increased the frequency with which they urinated when placed with males (regardless of male sexual activity) but not females. Furthermore, females showed a strong tendency to urinate when rising into spawning substrate, suggesting they might be using urine as an attractive lure. This hypothesis was confirmed by a second experiment, which found that 15K-PGF2α attracted males to specific locations. We conclude that goldfish, and likely many other fish, control the release of urinary prostaglandin pheromones to advertise their condition and location, perhaps exemplifying an early step in the evolution of a chemical communication system.
Atypical Cells in the Cerebrospinal Fluid of a 43-Year-Old Man With Perioral Parasthesias

1. What is (are) this patient’s most striking clinical and laboratory findings? 2. How do you explain the patient’s most striking clinical and laboratory findings? 3. What is this patient’s most likely diagnosis? 4. What is the characteristic clinical presentation of an individual with this patient’s condition? 5. What are the criteria for making this diagnosis? 6. What is the pathogenesis of this patient’s disease? 7. What is the prognosis for this patient? 8. What treatment options are available for this patient’s condition? 9. How did performing a cell count on the CSF contribute to this case?
Urban Life and Differential Fertility: Specification of an Aspect of the Theory of the Demographic Transition*

(1969). Urban Life and Differential Fertility: Specification of an Aspect of the Theory of the Demographic Transition. The Sociological Quarterly: Vol. 10, No. 4, pp. 480-500.
CS3: Large Strain Consolidation Model for Layered Soils

AbstractA numerical model, called CS3, is presented for one-dimensional, large strain consolidation of layered soils. The algorithm accounts for vertical strain, soil self-weight, conventional constitutive relationships, changing material properties during consolidation, unload/reload, time-dependent loading and boundary conditions, an externally applied hydraulic gradient, and multiple soil layers with different material properties. CS3 can accommodate equilibrium and nonequilibrium profiles for the initial void ratio as well as variable profiles for preconsolidation stress and applied stress increment. Verification checks show excellent agreement with available analytical and numerical solutions. Several numeric examples are used to illustrate the capabilities of CS3 and highlight errors that may occur when multilayer systems are modeled as a single layer with average properties. Finally, settlement estimates obtained using CS3 are in good agreement with field measurements for the Gloucester test fill.
Mechanistic studies on bleomycin-mediated DNA damage: multiple binding modes can result in double-stranded DNA cleavage.

The bleomycins (BLMs) are a family of natural glycopeptides used clinically as antitumor agents. In the presence of required cofactors (Fe2+ and O2), BLM causes both single-stranded (ss) and double-stranded (ds) DNA damage with the latter thought to be the major source of cytotoxicity. Previous biochemical and structural studies have demonstrated that BLM can mediate ss cleavage through multiple binding modes. However, our studies have suggested that ds cleavage occurs by partial intercalation of BLM's bithiazole tail 3′ to the first cleavage site that facilitates its re-activation and re-organization to the second strand without dissociation from the DNA where the second cleavage event occurs. To test this model, a BLM A5 analog (CD-BLM) with β-cyclodextrin attached to its terminal amine was synthesized. This attachment presumably precludes binding via intercalation. Cleavage studies measuring ss:ds ratios by two independent methods were carried out. Studies using [32P]-hairpin technology harboring a single ds cleavage site reveal a ss:ds ratio of 6.7 ± 1.2:1 for CD-BLM and 3.4:1 and 3.1 ± 0.3:1 for BLM A2 and A5, respectively. In contrast with BLM A5 and A2, however, CD-BLM mediates ds-DNA cleavage through cooperative binding of a second CD-BLM molecule to effect cleavage on the second strand. Studies using the supercoiled plasmid relaxation assay revealed a ss:ds ratio of 2.8:1 for CD-BLM in comparison with 7.3:1 and 5.8:1, for BLM A2 and A5, respectively. This result in conjunction with the hairpin results suggest that multiple binding modes of a single BLM can lead to ds-DNA cleavage and that ds cleavage can occur using one or two BLM molecules. The significance of the current study to understanding BLM's action in vivo is discussed.
Glycophorins of human erythroleukemic K562 cells.

Abstract Glycophorins related to α glycophorin, of the human erythrocyte membrane, were isolated from human erythroleukemic K562 cells. The glycophorins were purified using sodium dodecyl sulfate (SDS)/trichloroacetic acid fractionation and Folch and hot phenol extractions. 0.1–0.2 μg was obtained/10 8 cells, or ~ a 15% yield. SDS-gel electrophoresis revealed a pattern similar to erythrocyte α glycophorin except for the slower mobility of the glycophorin monomer. Two populations of K562 glycophorins, present in nearly equivalent amounts, were distinguished by their binding to Lens culinaris lectin agarose. The two populations exhibited similar gel electrophoretic patterns except for the presence of δ-like glycophorin exclusively in the population that did not bind to L. culinaris lectin. Immunoblotting revealed a lack of reaction of the major α and δ-like glycophorin bands in all K562 glycophorins with M or N erythrocyte glycophorin-specific monoclonal antibodies. Only minor species of intermediate electrophoretic mobility in glycophorins not binding to L. culinaris showed a reaction with these antibodies. Both populations of glycophorins incorporated radiolabeled glucosamine, mannose, and fucose and contained O-glycosidically linked tri- and tetrasaccharides, present in a ratio of ∼1:1 indicating a significant degree of hyposialylation when compared to erythrocyte α glycophorin. No precursor/product relationship was demonstrated between the major forms of two populations. K562 cell surface labeling with lactoperoxidase revealed that only the glycophorins that exhibited binding to L. culinaris were accessible to iodination and could be the only species expressed at the cell surface.
A New Constant Fraction Timing System with Improved Time Derivation Characteristics

A constant fraction timing system having excellent time derivation properties over a wide dynamic range of signals is described. Leading edge walk is significantly reduced by arming the constant fraction zero-crossing circuit with a discriminator that is separate from the energy discriminator. Timing resolution with Ge(Li) detectors can be improved by the optional use of a slow risetime reject circuit, but only at the expense of reduced counting efficiency. This performance trade-off is described in detail. Extensive data are presented on the timing performance in ?-? coincidence experiments.
Hartree-Fock-Bogoliubov theory without quasiparticle vacua

Hartree-Fock-Bogoliubov (HFB) theory is generalized by eliminating the restriction to quasiparticle vacuum states. However, the fundamental HFB transformation to quasiparticles is retained. The theory is formulated in terms of the quasiparticle density matrix $R$, but, in contrast to conventional HFB, there is no restriction to vacuum densities ${R}^{2}=R$.
The prebiotic synthesis of deoxythymidine oligonucleotides.

The only successful syntheses so far reported for the prebiotic formation of oligodeoxyribonucleotides involve the condensation, under warm aqueous conditions of deoxythymidine 5’-phosphate, using either cyanamide (Ibanez et al., 1971a, b) or imidazole (Ibanez et al., 1971b, c) as catalysts. In both condensations, oligomers of up to five units in length were obtained, but the total yields were less than 2%. The majority of syntheses which have led to the formation of oligoribonucleotides have been conducted under drying conditions at relatively high or moderate temperatures, the latter simulating the effects resulting from the drying up of primeval lakes and ocean beds (Moravek et al., 1968a, b, c; Tapiero and Nagyvary, 1971; Osterberg et al., 1973). In view of the success of these reactions it was decided to continue our work on the synthesis of oligodeoxyribonucleotides and to study the effects of drying conditions on the formation of these compounds.
What Would You Do, Doctor?

The first time I remember hearing, or perhaps really feeling, this question came when I was a junior resident in pediatrics. By then I had assembled a small cohort of primary care patients for whom I truly felt responsible. With the initial shock and blind ignorance of intern year behind me, I had begun to understand my role in guiding my patients through a healthy childhood, or at least navigating through a complex medical system. One patient, Alek, was a sweet 4-year-old boy, whose parents had emigrated from Albania in the hopes of improving his medical condition. Alek was missing a small part of chromosome 4, which resulted in a host of problems including development delays, seizure disorder, vision problems, and chronic aspiration. He couldn’t speak and barely walked. He was happy, bubbly, and beloved. His mother and father would bring him to his clinic appointments dressed in their Sunday finest—he in a navy blue sweater with a cartoon character emblazoned on the front, his mother in a long flowery dress with boots, and his father in a tie. They always brought me some sort of gift, a box of candy or Alek’s preschool picture in the same navy blue sweater he wore to his appointments. I still have that picture in my desk.
Collateral methotrexate resistance in cisplatin-selected murine leukemia cells.

Resistance to anticancer drugs is a major cause of failure of many therapeutic protocols. A variety of mechanisms have been proposed to explain this phenomenon. The exact mechanism depends upon the drug of interest as well as the tumor type treated. While studying a cell line selected for its resistance to cisplatin we noted that the cells expressed a >25,000-fold collateral resistance to methotrexate. Given the magnitude of this resistance we elected to investigate this intriguing collateral resistance. From a series of investigations we have identified an alteration in a membrane protein of the resistant cell as compared to the sensitive cells that could be the primary mechanism of resistance. Our studies reviewed here indicate decreased tyrosine phosphorylation of a protein (molecular mass = 66) in the resistant cells, which results in little or no transfer of methotrexate from the medium into the cell. Since this is a relatively novel function for tyrosine phosphorylation, this information may provide insight into possible pharmacological approaches to modify therapeutic regimens by analyzing the status of this protein in tumor samples for a better survival of the cancer patients.
Longitudinal MRI studies in the isoflurane‐anesthetized rat: long‐term effects of a short hypoxic episode on regulation of cerebral blood flow as assessed by pulsed arterial spin labelling

MRI is a powerful tool for measuring cerebral blood flow (CBF) longitudinally. However, most animal studies require anesthesia, potentially interfering with normal physiology. Isoflurane anesthesia was used here to study CBF regulation during repetitive scanning in rats. MR perfusion images were acquired using FAIR (flow-sensitive alternating inversion recovery) arterial spin labeling, and absolute CBF was calculated. CBF changes in response to a hypoxic (12% O2) and hypercapnic (5% CO2) gas stimulus were monitored. Hypercapnia led to a robust increase in CBF compared with baseline (195.5+/-21.5 vs 123.6+/-17.9 ml/100 g/min), and hypoxia caused a smaller non-significant increase in mean CBF values (145.4+/-13.4 ml/100 g/min). Strikingly, when measurements were repeated 5 days later, CBF was dramatically reduced in hypoxia (93.2+/-8.1 ml/100 g/min) compared with the first imaging session. Without application of the hypoxic and hypercapnic gases during the first MRI, baseline CBF and CBF changes in response to hypoxia at the second MRI were similar to naive rats. Blood gas analyses revealed a slight reduction in arterial oxygenation during the second period of anesthesia compared with the first. These findings indicate that, in isoflurane-anesthetized rats, even a short hypoxic episode can have long-lasting effects on cerebrovascular regulation.
AlGaN/GaNHEMT with High PAE and Breakdown Voltage Grown by Ammonia MBE

In this paper, a report on high PAE, high breakdown-voltage HEMTs grown by ammonia MBE is discussed. First, an AlN nucleation layer was grown by plasma-assisted MBE on SiC. Then GaN buffer was grown by ammonia MBE, followed by 30 nm ammonia Al0.3Ga0.7N. A sheet charge of 1x1013 cm-2 with a mobility of 1500 cm2V-1s-1 was obtained from Hall measurements.
A novel reducing agent derived from formic acid and two equivalents of a grignard reagent: Chemoselective reduction of aldehydes

Abstract Aldehydes are reduced at a moderate rate by use of a novel reagent obtained by the addition of two molar equivalents of ethylmagnesium bromide to formic acid in tetrahydrofuran solution. Under similar conditions the reduction of ketones proceeds quite slowly.
Paul T. Baker (1927–2007)

Paul T. Baker (1927–2007) was the conceptual founder and practitioner of the field of human adaptability in physical anthropology. From the 1960s through the 1990s he and more than two dozen of his...
Critical field anisotropy in (TMTSF)2 CLO4 in the basal plane

Abstract We have performed detailed measurements of the critical field of (TMTSF)2 ClO4 in the plane perpendicular to the highly conducting a axis. We find a large anisotropy with the field in the c direction having a value which is more than an order of magnitude less than along the b direction. The b axis critical field is only slightly (50%) less than the a axis (the highly conducting direction). The angular and temperature dependences suggest that the anisotropy is a band structure effect along b and c, but that the a direction critical field is Pauli limited. These results imply that critical field anisotropy in the directions parallel and perpendicular to the highly conducting a axis cannot be used go obtain information about the band structure anisotropy and that the observed superconductivity is singlet rather than triplet.
Modeling spatial distribution of floc size in turbulent processes using the quadrature method of moment and computational fluid dynamics

Abstract A study was performed that utilizes the quadrature method of moments (QMOM) to model the transient spatial evolution of the floc size in a heterogeneous turbulent stirred reactor. The QMOM approach was combined with a commercial computational fluid dynamics (CFD) code (PHOENICS), which was used to simulate the turbulent flow and transport of these aggregates in the reactor. The CFD/QMOM model was applied to a 28 l square reactor containing an axial flow impeller and 100 mg/l concentration of 1 μ m nominal clay particles. Simulations were performed for different average characteristic velocity gradients ( 40 , 70 , 90 , and 150 s - 1 ). The average floc size and growth rate were compared with experimental measurements performed in the bulk region and the impeller discharge region. The CFD/QMOM results confirmed the experimentally measured spatial heterogeneity in the floc size and growth rate. In addition, the model predicts spatial variations in the aggregation and breakup rates. Finally, the model also predicts that the transport of flocs into the high shear impeller discharge zone was responsible for the transient evolution of the average floc size curve displaying a maximum before decreasing to a steady-state floc size.
Influence of self-complementary hydrogen bonding on solution rheology/electrospinning relationships

Abstract A series of poly(alkyl methacrylate)s that contained either pendant carboxylic acid or self-complementary multiple hydrogen bonding (SCMHB) groups were synthesized to determine the influence of intermolecular associations on solution rheology and electrospinning performance. The cosolvent composition was varied in order to control the dielectric constant of the electrospinning solvent. By controlling the dielectric constant of the solvent, intermolecular interactions were systematically screened, and the influence of hydrogen bonding on electrospun fiber morphology was determined. While the diameter of the electrospun poly(methyl methacrylate) (PMMA) fibers were in excellent agreement with previously developed predictions, the diameter of the electrospun poly(methyl methacrylate-co-methacrylic acid) (PMMA-co-PMAA) fibers were smaller than predicted when electrospun from dimethyl formamide (DMF). The smaller PMMA-co-PMAA fibers were attributed to dissociation of the carboxylic acid group, which resulted in increased solution conductivity. The poly(methyl methacrylate-co-SCMHB methacrylate) (PMMA-co-SCMHB) displayed significant hydrogen bonding associations with decreasing solvent dielectric constant (D) which resulted in increased viscosity and lower entanglement concentration (Ce). Moreover, strong hydrogen bonding between the SCMHB groups in relatively nonpolar solvents increased the apparent molecular weight of the copolymers, and significantly larger electrospun fibers than predicted were obtained.
Quantum state resolved velocity-map imaging spectroscopy: A new tool for collision dynamics at gas/self-assembled monolayer interfaces

The dynamics of HCl scattering from a room-temperature –CH3 terminated self-assembled monolayer (SAM) is probed via state-resolved spectroscopy coupled to a velocity-map imaging (VMI) apparatus. The resulting velocity maps provide new insight into the HCl scattering trajectories, revealing for the first time correlations between internal and translational degrees of freedom. Velocity maps at low J are dominated by signatures of both the incident beam (17.3(3) kcal mol−1) and a room-temperature trapping–desorption component (TD). At high J, however, the maps contain a large, continuous feature associated primarily with impulsive scattering (IS). Trajectories resulting from these strongly inelastic interactions are readily isolated in the map, and provide a new glimpse into purely impulsive scattering dynamics. Specifically, within the purely-IS HCl region of the velocity maps, the rotational distribution is found to be remarkably Boltzmann like, but with a temperature (472 K) significantly higher than the SAM surface (300 K). By way of contrast, the translational degree of freedom of the impulsively-scattered flux is clearly non-Boltzmann in character, with a strong propensity for in-plane scattering in the forward direction, and yet still exhibiting out-of-plane velocity distributions reasonably well characterized by a temperature of 690 K. These first data establish the prospects for a new class of experimental tools aimed at exploring energy transfer and reactive scattering events on SAMs, liquid, and metal interfaces with quantum state resolved information on correlated internal and translational distributions.
Apparatus for analytical scale hydrogenation reactions at elevated temperatures and pressures

Abstract An inexpensive, analytical-scale hydrogenation apparatus is constructed. Nearly all parts are commercially avaialble. The reaction takes place in a glass vial of ≤10 ml size with magnetic stirring up to medium temperatures (≤ 140°C) and pressures (≤ 250 p.s.i. of hydrogen). The vai is housed in a modified PTFE Digestion Vessel.
Complex demonstratives and their singular contents

This paper presents a semantic and pragmatic theory of complex demonstratives. According to this theory, the semantic content of a complex demonstrative, in a context, is simply an object, and the semantic content of a sentence that contains a complex demonstrative, in a context, is a singular proposition. This theory is defended from various objections to direct reference theories of complex demonstratives, including King's objection from quantification into complex demonstratives.
On the development of idiopathic subglottic stenosis

Idiopathic subglottic stenosis is a fibrotic narrowing of the airway at the level of the cricoid cartilage, which can result in severe dyspnea. There is an overwhelming female preponderance, and treatment usually involves dilation, tracheostomy or resection with reconstruction of the involved portion of the airway. The exact mechanism of action is unknown. Estrogen has been thought to play a role in the pathogenesis of this disease, but estrogen receptors have not been found in tissue specimens taken from afflicted individuals. A careful history taken from the patient often reveals a severe episode of coughing prior to the development of symptoms, and intraoperative examination can reveal impaction of the first tracheal ring within the lumen of the cricoid cartilage. Based on these observations, we surmise that an intermittent telescoping effect of the first tracheal ring within the lumen of the cricoid cartilage can lead to disruption of the local blood supply and trauma to the cricoid mucosa, with consequent mucosal edema, ischemia, and ultimately fibrosis. While estrogen has been shown to play a beneficial role in wound healing, abnormal wound healing may be potentiated by variations in estrogen receptor expression, and could also explain the female preponderance seen in this disease.
The Yersinia enterocolitica Ysa type III secretion system is expressed during infections both in vitro and in vivo

Yersinia enterocolitica biovar 1B maintains two type III secretion systems (T3SS) that are involved in pathogenesis, the plasmid encoded Ysc T3SS and the chromosomally encoded Ysa T3SS. In vitro, the Ysa T3SS has been shown to be expressed only at 26°C in a high-nutrient medium containing an exceptionally high concentration of salt – an artificial condition that provides no clear insight on the nature of signal that Y. enterocolitica responds to in a host. However, previous research has indicated that the Ysa system plays a role in the colonization of gastrointestinal tissues of mice. In this study, a series of Ysa promoter fusions to green fluorescent protein gene (gfp) were created to analyze the expression of this T3SS during infection. Using reporter strains, infections were carried out in vitro using HeLa cells and in vivo using the mouse model of yersiniosis. Expression of green fluorescent protein (GFP) was measured from the promoters of yspP (encoding a secreted effector protein) and orf6 (encoding a structural component of the T3SS apparatus) in vitro and in vivo. During the infection of HeLa cells GFP intensity was measured by fluorescence microscopy, while during murine infections GFP expression in tissues was measured by flow cytometry. These approaches, combined with quantification of yspP mRNA transcripts by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), demonstrate that the Ysa system is expressed in vitro in a contact-dependent manner, and is expressed in vivo during infection of mice.