cssi/SciSciGPT-SciSciNet huggingface dataset:
A rabbit-in vitro system to evaluate drug action against Plasmodium falciparum

Abstract A rabbit-in vitro model system is described which can determine the activity of anti-malarial drugs against erythrocytic stages of Plasmodium falciparum. Serum samples, collected from rabbits at various times after drug administration, were incubated with synchronized ring form parasites using the micro test system. The extent to which the presence of drugs in the serum inhibited parasite growth was usually determined after 32 to 40 hours of incubation. Anti-malarial activity was observed in sera obtained from rabbits which received chloroquine, mefloquine, pyrimethamine and cycloguanil, but not in those which received 4-4′ diacetyldiaminodiphenylsulphone (DADDS). The effects against the drug-sensitive strain were more marked than against the drug-resistant one. The serum activity persisted for a longer period of time after administration of mefloquine, pyrimethamine, pamoate, and cycloguanil pamoate than after administration of chloroquine, a drug with a shorter biological half-fife. The results indicate that this model may be a useful system for identifying potential agents against drug-resistant falciparum malaria, particularly compounds which are converted in vitro to their active metabolites or which exert a prolonged suppressive activity after drug administration.
Behavior and the Brain: Mediation of Acquired Skills

In this article, we employ a systems approach that crosses three levels of analysis—neurophysiology, psychology, and anthropology—to investigate the relationship between childhood experiences and adult skills. Our hypothesis is that early learning situations can result in neural entrainments, that have psychological consequences, some of which can later be reflected in a constellation of adult skills. This model can account for an association of adult behaviors that would otherwise resist explanation. In support of our model, we present both quantitative data resulting from treatments of ethnographic evidence contained in the Human Relations Area Files, and qualitative evidence abstracted from that source and from additional ethnographies.
Studies on the Mechanism of Phosphatidylinositol 3-Kinase Inhibition by Wortmannin and Related Analogs

Wortmannin, a fungal metabolite, was identified as a potent inhibitor (IC50 = 4.2 nM) of phosphatidylinositol 3-kinase (PI 3-kinase). Due to the importance of PI 3-kinase in several intracellular signaling pathways, structure-activities studies on wortmannin analogs were performed in an effort to understand the structural requirements necessary for PI 3-kinase inhibition. Since wortmannin is an irreversible inhibitor of PI 3-kinase, it was postulated that covalent attachment at the electrophilic C-21 site was a possible mode of action for PI 3-kinase inhibition. We have prepared various wortmannin analogs which address the possibility of this mechanism. Of particular interest are compounds which affect the C-21 position of wortaminnin either sterically or electronically. Our results support the conclusion that nucleophilic addition by the kinase onto the C-21 position of wortmannin is required for inhibition of PI 3-kinase by wortmannin analogs. Additionally, we have prepared several D-ring analogs of wortmannin, and their activities are reported herein. We conclude that the wortmannin D ring is an important recognition site since modifications have such a dramatic effect on inhibitor potency. Finally, the identification of 17beta-hydroxywortmannin represents the first reported subnanomolar inhibitor of PI 3-kinase. These studies, along with in vivo antitumor experiments, suggest that the mechanism of PI 3-kinase inhibition correlates to the associated toxicity observed with wortmannin-based inhibitors of PI 3-kinase.
Arachidonic acid and diacylglycerol act synergistically through protein kinase C to persistently enhance synaptic transmission in the hippocampus

Abstract In model membranes, arachidonic acid and diacylglycerol have been proposed to synergistically induce a membrane-inserted, constitutively active form of protein kinase C. We have investigated the effects of these lipid protein kinase C activators on synaptic efficacy in the Schaffer collateral input to CA1 hippocampal pyramidal cells. Arachidonic acid (5 μ M) perfusion combined with repetitive afferent stimulation had no consistent effect on field excitatory postsynaptic potentials recorded in stratum radiatum, while treatment with a cell-permeable diglyceride, oleoyl-acetylglycerol (5 μg/ml), followed by stimulation, led to a short-term potentiation. By contrast, the combination of oleoyl-acetylglycerol and arachidonic acid gave rise to a long-lasting non-decremental potentiation of field excitatory postsynaptic potentials. The induction of potentiation was “activity dependent”, as there was either no significant effect or there was a measurable depression when repetitive synaptic stimulation was omitted. Furthermore, consistent with a protein kinase C-dependent process, the potentiation was blocked by the kinase inhibitors H-7 and staurosporine. The results suggest that relatively low concentrations of arachidonic acid and diacylglycerol work synergistically through protein kinase C to persistently enhance synaptic transmission. This synergy has the makings of an associative (Hebbian) device for long-term potentiation induction operating at the second messenger level.
Whose Epidemiology, Whose Health?

Simplistic claims about the objectivity of science have been challenged from a variety of perspectives. Evaluation of the external context of production of knowledge and the methodological approach...
Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men

Correction to Richard J Bloomer, Kelsey H Fisher-Wellman, Kelley G Hammond, Brian K Schilling, Adrianna A Weber and Bradford J Cole: Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men. Journal of the International Society of Sports Nutrition 2009, 6: 4
Effects of gyrase mutation on the growth kinetics of ciprofloxacin-resistant strains of Clostridium perfringens.

Abstract To investigate the effect of gyrA mutation on resistance of Clostridium perfringens to fluoroquinolones, a ciprofloxacin-resistant mutant was developed. The mutant had a single substitution in gyrA at position 87 (Asp to Tyr) and no additional mutations in gyrB, parC or parE. The MIC values of gatifloxacin and ciprofloxacin for this strain were 16 and 32-fold higher than those for the wild type, which were 0.125 and 0.250 μg/mL, respectively. The resistant mutant grew equally well in the presence or absence of 5 μg/mL of ciprofloxacin or 1 μg/mL of gatifloxacin and grew to lower cell densities with up to 30 μg/mL of ciprofloxacin or 5 μg/mL of gatifloxacin. Higher concentrations of fluoroquinolones resulted in increases in the time required to reach the end of the exponential phase and in lower cell densities at the end. The efflux pump inhibitor reserpine did not affect susceptibility to fluoroquinolones. The substitution of Asp 87 to Tyr in gyrA may have protected C. perfringens from low concentrations of ciprofloxacin and gatifloxacin and enabled survival and growth at higher concentrations.
Oral L-arginine supplementation impacts several reproductive parameters during the postpartum period in mares.

Abstract l -Arginine is an amino acid which can alter pituitary function and increase blood flow to the reproductive tract. The objective was to determine the effect of supplementing 100 g of l -arginine on plasma arginine concentrations, follicular dynamics and ovarian and uterine artery blood flow during the estrus that occurs subsequent to foaling. In Experiment 1, mares were fed 100 g l -arginine for 1 day during the last 3 weeks of pregnancy and plasma samples taken for every hour for the first 4 h and every other hour until 12 h. l -Arginine supplementation elevated plasma arginine concentrations from 1 to 8 h post feeding; arginine peaked at 6 h (arginine: 515 ± 33 μmol/L; control: 80 ± 33 μmol/L). In Experiment 2, mares received either 100 g l -arginine or control diets beginning 21 d before the expected foaling date and continued for 30 d postpartum. The reproductive tract was evaluated by transrectal Doppler ultrasonography from Day 1 postpartum through Day 30. There were no differences in ovarian follicular dynamics, ovarian or uterine resistance indices between groups. Vascular perfusion of the F1 follicular wall was greater in l -arginine supplemented mares (37.3 ± 2.6%) than controls (25.4 ± 2.7%; P l -Arginine supplemented mares had a smaller uterine body and horns and accumulated less uterine fluid than controls ( P l -arginine supplementation as a breeding management tool during the postpartum period to increase reproductive success.
Is JGR obsolescent

The time delay for publication of papers in the Space Physics section of the Journal of Geophysical Research has doubled in the past 10 years. This trend ought to cause some concern among the journal's publishers, contributors, and readers. JGR has played a vital and innovative role in the communication of research in the adolescent field of space physics. However, if the instrument of communication fails to keep pace with the research being communicated, both the instrument and the research must suffer. Rapid publication should not be the single overriding goal of a research journal; the need for prompt communication of new results is appropriately served by conferences, preprints, letter journals, and other less formal mechanisms. On the other hand, the purpose of a research journal should be to communicate not merely to chronicle the results of scientific research. As its name implies, the function of a research journal is to publish research while it is still research, not when it has become history.
Utility of Noninvasive Imaging in Suspected Saphenous Vein Graft Aneurysm Thrombosis

A 70-year-old man presented with 2 weeks of progressive typical angina without myocardial infarction. He had undergone coronary artery bypass grafting (CABG) in December 2006, using a left internal mammary graft to the left anterior descending artery, saphenous vein grafts (SVG) to the distal right coronary artery, and the second obtuse marginal branch of the left circumflex coronary artery. Coronary angiography showed a patent left internal mammary and SVG to the right coronary. The SVG to the circumflex filled slowly and was occluded midgraft without apparent distal perfusion of the circumflex system. Instead, on late angiographic images, contrast diffusion into an indistinct aneurysmal structure was noted (online-only Data Supplement Video 1). The native circulation had a calcified 95% distal left main stenosis and no …
Super Water- and Oil-Repellent Surfaces on Intrinsically Hydrophilic and Oleophilic Porous Silicon Films

We demonstrate that porous Si films fabricated by a convenient gold-assisted electroless etching process, which possess a hierarchical porous structure consisting of micrometer-sized asperities superimposed onto a network of nanometer-sized pores, are able to induce a superhydrophobic phenomenon on an intrinsically hydrophilic hydrogen-terminated Si surface and a superoleophobic phenomenon on an intrinsically oleophilic self-assembled monolayer-coated Si surface. Through comparison with porous Si films consisting of vertically aligned straight pores, which are hydrophilic and oleophilic, we show that an overhang structure resulting from the hierarchical porous structure is essential to preventing water and oil from penetrating the texture of the films and inducing the observed macroscopic superhydrophobic and superoleophobic phenomena.
The effect of X-radiation on the concentration of scopolin and caffeoylquinic acids in tobacco

Abstract Eighty-day-old tobacco plants were irradiated with 1000R, 2500R and 4400R of X-radiation, harvested 12, 21 and 29 days after treatment, and analyzed for chlorogenic acid, neochlorogenic acid, 4-0-caffeoylquinic acid (“band 510”) and scopolin. Dose dependent, post-irradiation accumulations of scopolin were observed in both young and old leaves. In roots and stems, scopolin concentrations first increased to 1·5–10 times that of comparable controls, and then declined in later harvests to levels below that of controls. Accumulations of caffeoylquinic acids were variable. Young leaves formed after treatment with 1000 R were twisted, malformed and contained lower caffeoylquinic acid concentrations on a fresh weight basis. Alternative speculations are discussed which could account for scopolin accumulations and the implications thereof.
A two-fluid model of turbulence for a thermal plasma jet

In this paper, a turbulent argon plasma jet issuing into a stagnant argon environment at 1 ATM is .studied by applying a two-fluid turbulence model, in order to advance our understanding of thermal plasma jets. The mathematical model has some similarities to the models of two-phase flows, so that the turbulent plasma jet is treated as a two-phase mixture. The governing equations include the transport equations far mass, momentum, and energy far two different fluid parcels (in-moving parcels and out-moving parcels). Auxiliary relations that govern the physical phenomena of the interfluid mass, momentum, and energy exchange are preserved together with a description of the mechanisms that control the growth or diminution of the fragment size. The results are presented with conditional- and unconditional-averaged forms and compared with experimental results from enthalpy-probe measurements. A well-known nondimensional farm (a Gaussian error function) can represent the radial distributions of the measured- and predicted-unconditional mean axial velocity and temperature in consecutive sections (20–45 mm from the nozzle exit). Further insight into the behavior of turbulent plasma jets can be gained by looking at the conditional fluid properties. The results show that this model can predict phenomena that escape more conventional models, e.g., the uninixing phenomenon.
The onset of thermo-bioconvection in a shallow fluid saturated porous layer heated from below in a suspension of oxytactic microorganisms

Abstract The aim of this paper is to present a continuum model for thermo-bioconvection of oxytactic bacteria in a porous medium and investigate the combined effects of microorganisms' upswimming and heating from below on the stability of bioconvection in a horizontal layer filled with a fluid saturated porous medium. Different from traditional bioconvection, thermo-bioconvection has two destabilizing mechanisms that contribute to creating the unstable density stratification. This problem may be relevant to a number of geophysical applications, such as the investigation of the dynamics of oxytactic species of thermophiles (heat loving microorganisms) living in hot springs, microbial-enhanced oil recovery, and modeling oil- and gas-bearing sedimentary basins. The utilization of the Galerkin method to solve a linear stability problem leads to a correlation between the critical value of the bioconvection Rayleigh number and the traditional “thermal” Rayleigh number.
Cellular and subcellular localization of (3H)-progesterone and its metabolites in rat uterus studied by autoradiography.

The cellular and subcellular localization of radioactivity after the injection of [3H]-progesterone in rat uterus was studied at 5, 15 and 60min, using dry-autoradiography. A clear pattern of radioactivity distribution was observed. In all animals studied, without and with estrogen pretreatment, radioactivity was concentrated most heavily in nuclei of muscle cells, with less marked nuclear concentration in stromal cells. Nuclei of the luminal and glandular epithelium remained unlabeled.
p53, bcl-2 and Retinoblastoma Proteins as Long-Term Prognostic Markers in Localized Carcinoma of the Prostate

AbstractPurpose: The accumulation of p53 and bcl-2 gene products as well as the loss of the retinoblastoma (Rb) gene product have been associated with prostate cancer progression. We assessed whether the levels of immunoreactivity for p53, Rb and bcl-2 are better long-term predictors of disease specific survival than conventional pathological parameters of the primary tumor, such as Gleason score, capsular penetration, seminal vesicle invasion, and percent tumor in the specimen, in patients with clinically localized prostate cancer treated with radical prostatectomy.Materials and Methods: A total of 71 patients with clinical stages A1 to B2 adenocarcinoma of the prostate underwent radical prostatectomy after a negative metastatic evaluation. No neoadjuvant or adjuvant treatments were given and causes of death were recorded. Prostatectomy specimens were analyzed to determine the conventional pathological parameters, and p53, Rb and bcl-2 immunohistochemical staining. Univariate and multivariate analyses we...
Gastroesophageal Reflux Is Not Associated With Dental Erosion in Children

Background & Aims Dental erosion is a complication of gastroesophageal reflux (GER) in adults; in children, it is not clear if GER has a role in dental pathologic conditions. Dietary intake, oral hygiene, high bacterial load, and decreased salivary flow might contribute independently to GER development or dental erosion, but their potential involvement in dental erosion from GER is not understood. We investigated the prevalence of dental erosion among children with and without GER symptoms, and whether salivary flow rate or bacterial load contribute to location-specific dental erosion. Methods We performed a cross-sectional study of 59 children (ages, 9–17 y) with symptoms of GER and 20 asymptomatic children (controls); all completed a questionnaire on dietary exposure. Permanent teeth were examined for erosion into dentin, erosion locations, and affected surfaces. The dentist was not aware of GER status, and the gastroenterologist was not aware of dental status. Stimulated salivary flow was measured and salivary bacterial load was calculated for total bacteria, Streptococcus mutans , and Lactobacilli . Results Controlling for age, dietary intake, and oral hygiene, there was no association between GER symptoms and dental erosion by tooth location or affected surface. Salivary flow did not correlate with GER symptoms or erosion. Erosion location and surface were independent of total bacteria and levels of Streptococcus mutans and Lactobacilli . Conclusions Location-specific dental erosion is not associated with GER, salivary flow, or bacterial load. Prospective studies are required to determine the pathogenesis of GER-associated dental erosion and the relationship between dental caries to GER and dental erosion.
Laser surface modification of AZ31B Mg alloy for bio-wettability

Laser surface modification of AZ31B Magnesium alloy changes surface composition and roughness to provide improved surface bio-wettability. Laser processing resulted in phase transformation and grain refinement due to rapid quenching effect. Furthermore, instantaneous heating and vaporization resulted in removal of material, leading the textured surface generation. A study was conducted on a continuum-wave diode-pumped ytterbium laser to create multiple tracks for determining the resulting bio-wettability. Five different laser input powers were processed on Mg alloy, and then examined by XRD, SEM, optical profilometer, and contact angle measurement. A finite element based heat transfer model was developed using COMSOL multi-physics package to predict the temperature evolution during laser processing. The thermal histories predicted by the model are used to evaluate the cooling rates and solidification rate and the associated changes in the microstructure. The surface energy of laser surface modification samples can be calculated by measuring the contact angle with 3 different standard liquid (D.I water, Formamide, and 1-Bromonaphthalen). The bio-wettability of the laser surface modification samples can be conducted by simulated body fluid contact angle measurement. The results of SEM, 3D morphology, XRD, and contact angle measurement show that the grain size and roughness play role for wetting behavior of laser processing Mg samples. Surface with low roughness and large grain size performs as hydrophilicity. On the contrast, surface with high roughness and small grain size performs as hydrophobicity.
Likelihood inference for linear regression models

SUMMARY Approximate conditional inference based on large-sample likelihood ratio methods is considered for the parameters of linear regression models. Mean and variance adjustments that improve the standard normal approximation to the conditional distribution of the signed square root of the log-likelihood-ratio statistic for a scalar parameter of interest are given. A Bartlett adjustment factor that improves the chi-squared approximation to the conditional distribution of the log-likelihood-ratio statistic for a vector parameter of interest is also presented. The accuracy of approximate confidence limits obtained by using the adjustments is demonstrated for a location-scale analysis of Darwin's data.
Digital Divide or Just Another Absentee Ballot?: Evaluating Internet Voting in the 2004 Michigan Democratic Primary

The use of Internet voting in public elections has been challenged based on claims that it is biased against minorities and lower income voters. Although previous research has supported these claim...
Molecular Evolution and Mosaicism of Leptospiral Outer Membrane Proteins Involves Horizontal DNA Transfer

Leptospires belong to a genus of parasitic bacterial spirochetes that have adapted to a broad range of mammalian hosts. Mechanisms of leptospiral molecular evolution were explored by sequence analysis of four genes shared by 38 strains belonging to the core group of pathogenic Leptospira species: L. interrogans, L. kirschneri, L. noguchii, L. borgpetersenii, L. santarosai, and L. weilii. The 16S rRNA and lipL32 genes were highly conserved, and the lipL41 and ompL1 genes were significantly more variable. Synonymous substitutions are distributed throughout the ompL1 gene, whereas nonsynonymous substitutions are clustered in four variable regions encoding surface loops. While phylogenetic trees for the 16S, lipL32, and lipL41 genes were relatively stable, 8 of 38 (20%) ompL1 sequences had mosaic compositions consistent with horizontal transfer of DNA between related bacterial species. A novel Bayesian multiple change point model was used to identify the most likely sites of recombination and to determine the phylogenetic relatedness of the segments of the mosaic ompL1 genes. Segments of the mosaic ompL1 genes encoding two of the surface-exposed loops were likely acquired by horizontal transfer from a peregrine allele of unknown ancestry. Identification of the most likely sites of recombination with the Bayesian multiple change point model, an approach which has not previously been applied to prokaryotic gene sequence analysis, serves as a model for future studies of recombination in molecular evolution of genes.
CCD focal plane array analog image processor

A focal plane array designed for real-time, general-purpose, image preprocessing is described. The analog charge-coupled device-based array operates in the charge domain and has sensing, storing, and computing capabilities. It captures the image data and performs local neighborhood operations. The array is digitally programmable and various image preprocessing tasks can be implemented. It uses a single instruction, multiple data parallel architecture with one processing element serving four pixels. It can be programmed to perform A/D conversion prior to output. The ultra-compact image processor is currently being fabricated with a 3-um, double-poly, double-metal process. The 48 X 48 pixel array is projected to achieve an internal throughput as high as 576 Mops with a 54 dB dynamic range (9-bit equivalent accuracy) and 180 um detector pitch. The total power dissipation is estimated to be 12 mW or less. The total size of the 59-pad chip is 9.4 X 9.4 mm2.
A note on the comparison of group means based on repeated measurements of the same subject.

Abstract Data generated from a prospective comparison study in which the response variable is measured at the onset of the investigation ( I ) and then again at the end of the exposure period ( F ) are usually analyzed by_either one of these two statistical methods: (1) comparing the mean change in the variable ( F — I ) between the two groups by the usual unpaired t -test; or (2) using covariance adjustment of F with I as the covariate. These two methods are valid only if ( F — I ) is independent of I . When ( F — I ) is dependent on I , only method (2) can provide valid statistical results. The reasons why method (1) produces erroneous statistical results are explained.
Polar cap arcs and the open regions

Abstract After reviewing the basic characteristics of the polar cap arcs, it is suggested that their appearance can be explained if the open region splits into two, one located in the dawn sector and the other in the dusk sector. It is suggested that a distinct splitting occurs temporarily when an IMF tangential discontinuity passes by the magnetosphere and the sign of the IMF By component changes at the discontinuity, provided that the IMF Bz component is positive on both sides. As a result, the dawn or the dusk side of the polar region will be connected to either the front side or the hind side of the discontinuity, depending on the sign of the By component across the discontinuity. As the dynamo process is expected to operate in each of the two open regions (as is the case in the single open region), it is reasonable to infer that a sheet of plasma and of field-aligned currents forms in the region between the two open regions, resulting in the polar cap arcs across the polar region. The four-cell convection pattern may also appear. A model of the magnetosphere is constructed to demonstrate such a possibility.
Tritium-containing targets for high-yield neutron generators

Abstract A description of the process and equipment used to fabricate the many large tritium-bearing targets, having an active area of 1000 cm 2 , used in the high-energy neutron reaction experiment is given. Details of the fabrication equipment and procedures are evaluated in terms of the performance characteristics (neutron yield and lifetime) of the completed targets when bombarded by a 400-mA, 150-kV deuteron beam. In general, most targets were successfully fabricated and produced an average neutron yield between 4 and 18 × 10 12 neutrons per second with a lifetime sufficiently long to meet the users' needs.
Structural analysis of glycosaminoglycans in animals bearing mutations in sugarless, sulfateless, and tout-velu. Drosophila homologues of vertebrate genes encoding glycosaminoglycan biosynthetic enzymes.

Mutations that disrupt developmental patterning in Drosophila have provided considerable information about growth factor signaling mechanisms. Three genes recently demonstrated to affect signaling by members of the Wnt, transforming growth factor-β, Hedgehog, and fibroblast growth factor families inDrosophila encode proteins with homology to vertebrate enzymes involved in glycosaminoglycan synthesis. We report here the biochemical characterization of glycosaminoglycans inDrosophila bearing mutations in sugarless, sulfateless, and tout-velu. We find that mutations insugarless, which encodes a protein with homology to UDP-glucose dehydrogenase, compromise the synthesis of both chondroitin and heparan sulfate, as would be predicted from a defect in UDP-glucuronate production. Defects in sulfateless, a gene encoding a protein with similarity to vertebrateN-deacetylase/N-sulfotransferases, do not affect chondroitin sulfate levels or composition but dramatically alter the composition of heparin lyase-released disaccharides. N-, 6-O-, and 2-O-sulfated disaccharides are absent and replaced entirely with an unsulfated disaccharide. A mutation intout-velu, a gene related to the vertebrate Exostoses 1 heparan sulfate co-polymerase, likewise does not affect chondroitin sulfate synthesis but reduces all forms of heparan sulfate to below the limit of detection. These findings show that sugarless, sulfateless, and tout-velu affect glycosaminoglycan biosynthesis and demonstrate the utility ofDrosophila as a model organism for studying the function and biosynthesis of glycosaminoglycans in vivo.
Solid phase graft copolymerization: Effect of interfacial agent

Solvents or interfacial agents have been used as media to perform various polymerization reactions. The selection of solvents to provide the appropriate medium for the reaction has opened up a totally new area for research. In the present study, three solvents, viz., toluene, decalin, and tetralin, were investigated in the preparation of polypropylene-maleic anhydride copolymers by solid phase graft copolymerization. The graft level was quantitatively determined by wet chemical methods and qualitative confirmations were made by Fourier transform infrared spectroscopy. It was found that toluene and decalin increased the surface area for reaction by swelling the polymer. The graft level increased with an increase in concentration of toluene and decalin. In the case of tetralin, the graft level decreased as the concentration of the solvent in the reactant mixture increased. It was experimentally observed that unlike toluene and decalin, tetralin did not cause swelling of the polymer at the reaction conditions. Therefore, the surface area available for reaction would be less when tetralin is used. Moreover, since tetralin dissolves the polymer rather than causing it to swell, the contact area for the reaction is further diminished by the formation of a monomolecular layer of solvent insulating the monomer from the polypropylene.
A calculation of the number of IgG molecules required per cell to fix complement

Abstract Two molecules of IgG need to be in close proximity upon a cell surface in order to bind complement. Here we obtain approximate results for the probability that two or more IgG molecules are closer than some minimum separation distance, given that N IgG molecules are bound to the cell. Determining this probability exactly is a classical unsolved problem in geometrical probability. We also estimate the probability of having n pairs of IgG molecules in close proximity and compute the expected number of IgG pairs. Our theoretical results are compared with experimental measurements on complement fixation by IgG.
Large-aperture, lightweight diffractive lenses for space applications

We have produced large aperture (up to 50 cm diameter) diffractive Fresnel lenses in thin (380 µm) glass sheets by photolithography and also in thin (60 µm) freestanding polymer membranes by replication.
Early Newtonian and Leibnizian development of the calculus

The contemporaneous development of the calculus in the seventeenth century by Newton and Leibniz is one of the most important mathematical achievements of all time. The independent development by two different people with differing notations and differing ways of thinking makes for a fascinating story in the history of mathematics. Teachers of calculus and the history of mathematics can profit from the following, brief account of this history along with references for further study. Also included are ideas for using the history in calculus and history of mathematics classes.
Necrotizing funisitis and herpes simplex infection of placental and decidual tissues: Study of four cases

Necrotizing funisitis (NF) is a macroscopically and microscopically distinctive pattern of umbilical cord inflammation recently heralded as presumptive of congenital syphilis. Four nonsyphilitic cases are presented in which herpes simplex virus (HSV) 2 antigen was demonstrated in the placenta by immunohistochemistry. The clinicopathologic findings in one case, including HSV 2 antigen in amniotic epithelium, subamniotic chorion, and Wharton jelly, indicate that NF was caused by chronic ascending primary HSV 2 infection, whereas those of the other three cases with HSV 2 Ag confined to decidual cell clusters suggest that NF was caused by chronic ascending bacterial infection and that latent endometrial HSV 2 infection was fortuitous. We conclude that (1) NF is caused by protracted inflammation of a structure whose normal anatomy precludes removal of inflammatory debris; (2) no single pathogen causes NF; and (3) NF is strongly associated with latent endometrial HSV 2 infection, which should be sought in all instances. Although latent HSV 2 endometrial infection may be more prevalent than currently recognized, we speculate that its strong association with NF may be more than causal; whereas the usual ascending bacterial infection leads to labor before NF has had sufficient time to develop, latent endometrial HSV 2 infection may alter local paracrine factors and delay parturition for the time sufficient to permit NF, a morphological hallmark of chronicity, to become apparent.
Hydrogen synthesis via combustion of fuel-rich natural gas/air mixtures at elevated pressure

Abstract Combustion of extremely fuel-rich ( Φ = 4 ) methane/air mixtures at elevated pressures is investigated as a potential means to generate molecular hydrogen by non-catalytic partial oxidation. This system is investigated both computationally and experimentally. The computations use a perfectly-stirred reactor model and an explicit methane cool-flame mechanism to investigate the effects of reactor parameters on reaction time and product composition. Under adiabatic conditions, such mixtures are predicted to autoignite at low temperatures ( ∼ 700 K ) for pressures exceeding 8.5 atm. Above 15 atm, conversion to products is complete in roughly 1 s. The dependence of reaction time and hydrogen yield is investigated as a function of inlet temperature, system pressure, and flame equivalence ratio. Actual product yields are measured in a tube reactor facility, and many of the predictions of the model, including long relaxation times to chemical equilibrium and temperatures exceeding the adiabatic flame temperature, are observed. Production of higher order hydrocarbons and carbonaceous deposits, which are not considered in the current kinetic model, are found to be a significant factor in the actual combustion environment.
Screened hybrid density functionals for solid-state chemistry and physics.

Density functional theory incorporating hybrid exchange–correlation functionals has been extraordinarily successful in providing accurate, computationally tractable treatments of molecular properties. However, conventional hybrid functionals can be problematic for solids. Their nonlocal, Hartree–Fock-like exchange term decays slowly and incorporates unphysical features in metals and narrow-bandgap semiconductors. This article provides an overview of our group’s work on designing hybrid functionals for solids. We focus on the Heyd–Scuseria–Ernzerhof screened hybrid functional [J. Chem. Phys. 2003, 118, 8207], its applications to the chemistry and physics of solids and surfaces, and our efforts to build upon its successes.
Kidney disease as a predictor of mortality in chronic spinal cord injury.

Background The purpose of this study is to assess the predictive value of proteinuria and creatinine clearance (CrCl) in relation to mortality in patients with spinal cord injury. Methods Computerized medical records covering 6 to 11 years were reviewed in 2004 to determine all-cause mortality. Long-term survival was assessed by means of Kaplan-Meier analysis. Multiple and stepwise Cox proportional hazards models were used to identify risk factors for mortality. The dependent variable was duration of survival in months. Potential predictors included proteinuria, CrCl, age, duration and type of injury, type of bladder management, ethnicity, diabetes mellitus, hypertension, coronary artery disease, hematocrit, serum albumin level, and serum cholesterol level. Results With the Cox model, proteinuria with protein of 500 mg/d or greater (hazard ratio [HR], 2.98), CrCl less than 60 mL/min ( Conclusion The presence of either proteinuria with protein of 500 mg/d or greater or CrCl less than 60 mL/min is associated independently with increased mortality in the chronic spinal cord injury population. The presence of both conditions further increases this risk.
Sexually abused boys

Abstract Male victims of child sexual abuse have received inadequate attention in the literature. This article is a retrospective review of the reports of 189 boys evaluated during 1983–85. This population was younger than those previously reported. Comparison to an age- and race-matched group of girl victims seen during the same period revealed many similarities in patterns of disclosure and perpetrator characteristics. The acts perpetrated against the boys included a wide array of invasive acts at all ages, but sodomy was more frequently reported in the older victims. Abnormal anogenital findings were seen more often in younger children, but the findings were often nonspecific. An examiner experienced with young children and infants is essential.
A multiplicity trigger processor for a quark-gluon plasma search at the Tevatron collider

Abstract A fast trigger processor was developed for the study of high multiplicity charged particle events in collisions at the Tevatron Collider accelerator. The processor allowed the scaling of triggers for specified multiplicity ranges and was incorporated in the fast trigger logic.
A radiation hybrid map of mouse chromosome 13.

A mouse radiation hybrid (RH) panel was used to make a framework map for the entire length of mouse chromosome (Chr) 13. Forty-one loci were typed, and while most used primers flanking simple sequence repeats, some genes were included. The most proximal and distal loci are D13Mit132 and D13Mit35. The estimate of map length for Chr 13 is 1328 cR. The map is compared with the same set of loci from the consensus map for Chr 13, which is 70 cM in length, and also with a recombinational map derived from an intraspecies cross typed for many of the same loci. The mouse RH panel gave good resolution for Chr 13 and at the distal end allowed separation of previously nonrecombinant markers that are present on a single 620-kb YAC clone. Data analysis was performed using the RH option for Map Manager QT. This framework RH map of Chr 13 is the second of a series of RH maps for mouse chromosomes.
Electrochemical measurements on metal oxide electrodes—II. Impedance measurements on Nb-doped single crystal TiO2

Abstract Mott—Schottky plots were measured on single crystal Nb-doped TiO 2 in aqueous buffer solutions and KCl electrolytes of concentration between 1 M and 10 −4 M KCl. The influence of surface pretreatment, nature of the dopant and solution conductivity on the Mott—Schottky plots was examined. The surface pretreatment was found to affect the frequency dispersion of the Mott—Schottky plots. Analyses of published data and results from the present study suggest that the point of zero charge of differently doped TiO 2 samples influences the flatband potential. The impedance measurements in KCl electrolytes showed that the flatband potential of single crystal Nb-doped TiO 2 could be determined in low conductivity electrolytes such as 10 −3 M KCl.
Fixation of the offset V osteotomy: Mechanical testing of 4 constructs

Abstract The purpose of this study was to assess 4 methods of fixation for the offset V osteotomy. Maximum load, failure energy, and stiffness were determined in a control group and in 4 different test models. There were 10 specimens for each group. The control group consisted of intact first ray sawbones. An offset V osteotomy was performed on each specimen in each of the 4 test groups. The osteotomies were fixated either with two 2.0-mm cortical screws, two 2.7-mm cortical screws, two 3.5-mm cortical screws, or one 2.7-mm cortical screw and a 0.045-in Kirschner wire, respectively. Each model was then loaded to failure with a computerized hydraulic-tensile testing machine. Results for maximum load to failure for all 4 fixation constructs showed a mean ranging from 113.0 to 144.0 N, a mean energy to failure ranging from 272.2 to 365.0 J, and a mean stiffness ranging from 21.3 to 27.0 N/mm. There were no statistically significant differences detected among the individual constructs. In the group fixated with 3.5-mm screws, there were statistically significant differences in all 3 parameters compared with the control group. In the groups fixated with 2.7-mm screws, 2.0-mm screws, and the 2.7-mm screw and Kirschner wire, there were statistically significant differences in the maximum load and the failure energy, but not in stiffness, when compared with the control group. These findings suggest that all 4 constructs provide similar mechanical properties when utilized for the fixation of the offset V osteotomy. (The Journal of Foot & Ankle Surgery 42(2):63-67, 2003)
The role of protein carboxyl groups in carbohydrate-concanavalin A interaction.

Abstract 1. 1. The role of carboxyl groups in the binding of specific carbohydrates to concanavalin A, the phytohemagglutinin of the jack bean, has been studied using two techniques: (1) H + titration in the presence and absence of methyl α- d -mannopyranoside, a specifically bound carbohydrate ligand and (2) chemical modification of the protein carboxyl groups employing glycine methyl ester and a water-soluble carbodiimide, in the presence and absence of the mannoside. 2. 2. It is shown that protein carboxyl groups are masked when concanavalin A is titrated in the presence of the sugar hapten and that this sugar glycoside also protects protein carboxyl groups from modification with glycine methyl ester.
Topical exposure of neonates to hexachlorophene: long-standing effects on mating behavior and prostatic development in rats.

Abstract Male and female rats were washed with pHisoHex (3% hexachlorophene, HCP) during the first 8 days of life, the “critical period” of neuroendocrine differentiation, in order to investigate potential alterations in sexual development. Female rats treated in such a manner had a normal onset of puberty, regular 4 to 5-day estrous cycles, and were fertile when tested at 4.5 months of age. Seven-month-old male rats exposed to pHisoHex had significantly reduced fertility. When exposed to female rats at 11 months of age the males mounted and intromitted, but did not ejaculate. Many of the animals exposed to pHisHex had prostatic cysts and fibrosis. Serum testosterone concentrations were normal, testicular weights were not affected, and epididymal smears had abundant motile sperm. The infertility of adult male rats was the result of their inability to ejaculate. HCP may be responsible for these results, however, other data suggest that HCP may be contaminated with dioxins, toxic substances with androgen-like activity. Since other work shows that dissociation of intromission and ejaculation occurs in properly primed androgen-treated rats, it is possible that dioxin, as an “androgenic” contaminant of HCP, is responsible for permanent disruption of the CNS-integrated ejaculatory reflex.
High Potassium and Low Sodium Contractures in Sheep Cardiac Muscle

Contractures develop in sheep atrial trabeculae if Tyrode9s solution is rapidly replaced by a solution containing elevated potassium, reduced sodium, or both. Two phases of the contracture can be identified on the basis of differences in physiological behavior: a rapid and transient phase that predominates during the first few seconds of the contracture, and a slowly developed phase that is responsible for the steady level of tension reached later in the contracture. The transient phase is particularly prominent if the muscle is stimulated rapidly before the contracture, and reduced or absent if the muscle is not stimulated or if calcium is not present before the contracture. Recovery of the transient phase after a contracture parallels the recovery of twitches. This transient phase appears to reflect the depolarization-induced release of activator (calcium) from an internal store, possibly the same store that is involved in the normal contraction. The slowly developed tension is dependent on the contracture solution used, and is decreased if the calcium concentration is reduced or if the sodium concentration is increased. It does not depend on conditions before the contracture and does not require time to recover. This phase of the contracture may be due to entry of calcium from the extracellular solution.
Inhibition effects in back-mutation tests with mutants of Neurospora.

THE observation of Grigg1 that large numbers of conidia of biochemically deficient mutant strains of Neurospora crassa strongly inhibit the growth of ‘wild-type’ conidia when plated on minimal medium containing 0.2 per cent sucrose and 0.4 per cent sorbose led him to question the validity of back-mutation tests. On the other hand, Kolmark and Westergaard2 have reported that in comparable experiments (using an adenine mutant W 40) the substitution of a minimal medium containing 2 per cent glucose completely abolishes the growth inhibition. They suggest that the inhibition of ‘wild-type’ conidia on sorbose medium results from a removal by the large population of germinating mutant spores of the limited amount of sucrose available; they conclude, therefore, that the growth inhibition has no relation to back-mutation tests as usually conducted.
Perceived stress and severity of perimenstrual symptoms: the BioCycle Study.

Abstract Objective: To examine the longitudinal relation between perceived stress in the previous month and perimenstrual symptom severity across two cycles among regularly menstruating, healthy women (n = 259). Methods: At baseline (11 days before the first cycle), participants completed the 4-item Perceived Stress Scale (PSS) for the previous month (first cycle exposure) and questionnaires on lifestyle factors. On cycle day 22 of a standardized 28-day cycle, participants again completed the PSS for the previous week (second cycle exposure) and each week rated the severity (none, mild, moderate, severe) of 17 psychological and physical symptoms (e.g., crying, cramping, pain). Mixed models estimated the association between perceived stress scores and number of moderate/severe symptoms and symptom severity scores, allowing both stress and perimenstrual symptoms to vary by cycle. Results: Adjusting for age, education, passive and active smoking, and waist/height ratio (WHtR), high stress (fourth quartile PS...
The market organism: Long-run survival in markets with heterogeneous traders

Abstract The information content of prices is a central problem in the general equilibrium analysis of competitive markets. Rational expectations equilibrium identifies conditioning simultaneously on contemporaneous prices and private information as the mechanism by which information enters prices. Here we look to the ecology of markets for an explanation of the information content of prices. Markets could select across traders with different beliefs, or, reminiscent of ‘the wisdom of crowds’, markets could balance the diverse information of many participants. We provide theoretical support in favor of the first mechanism, and against the second. Along the way we demonstrate that the necessary condition for long-run survival in complete markets found in Sandroni [2000. Do markets favor agents able to make accurate predictions? Econometrica 68 (6), 1303–1342] and in Blume and Easley [2006. If you’re so smart, why aren’t you rich? Belief selection in complete and incomplete markets. Econometrica 74 (4), 929–966] is not sufficient for long-run survival. We also demonstrate some surprising behavior of market prices when several trader types with different beliefs survive. This paper continues the research program of Blume and Easley [1992. Evolution and market behavior. Journal of Eonomic theory 58 (1), 9–40] and Beker and Chattopadhyay [2006. Consumption dynamics in general equilibrium: a characterisation when markets are incomplete, University of Warwick, unpublished].