cssi/SciSciGPT-SciSciNet huggingface dataset:
Wnt signaling: a common theme in animal development

Wnt proteins are now recognized as one of the major families of developmentally important signaling molecules, with mutations in Wnt genes displaying remarkable phenotypes in the mouse, Caenorhabditis elegans, and Drosophila. Among functions provided by Wnt proteins are such intriguing processes as embryonic induction, the generation of cell polarity, and the specification of cell fate. Until recently, our knowledge of the molecular mechanism of Wnt signaling was very limited, but over the past year, several major gaps have been filled. These include the identification of cell-surface receptors and a novel mechanism of relaying the signal to the cell nucleus. In addition, several components of Wnt signaling are implicated in the genesis of human cancer. These insights have come from different corners of the animal kingdom and have converged on a common pathway. At this junction in this rapidly evolving field, we review our current understanding of Wnt function and signaling mechanisms, doing so in a comparative approach. We have put emphasis on the latest findings, highlighting novelty and underscoring questions that remain. For additional literature, we refer to several previous reviews (McMahon 1992; Nusse and Varmus 1992; Klingensmith and Nusse 1994; Miller and Moon 1996; Moon et al. 1997). We have limited the number of references, particularly in the tables. Fully referenced forms of these tables can be found on the Wnt homepage (http://wwwleland.stanford.edu/∼rnusse/wntwindow.html).
Discovery of novel 1H-imidazol-2-yl-pyrimidine-4,6-diamines as potential antimalarials

A novel family of 1H-imidazol-2-yl-pyrimidine-4,6-diamines has been identified with potent activity against the erythrocyte-stage of Plasmodium falciparum (Pf), the most common causative agent of malaria. A systematic SAR study resulted in the identification of compound 40 which exhibits good potency against both wild-type and drug resistant parasites and exhibits good in vivo pharmacokinetic properties.
The Selection of Window Widths in Kernel Nonparametric Regression

The estimation of the regression function using kernel density estimation techniques has long been hindered by reliance on subjective techniques for determining the window width required. Recent work in data-based optimal selection of nonparametric density estimates has eliminated the subjectivity of window selection for density estimation, but less attention has been given to the specialized nature of the kernel regression estimators. In this work, we demonstrate intuitively and empirically that a certain optimal bivariate window width is to be preferred over optimal univariate window widths in forming kernel estimators of r(x). Simulations also reveal how well data-based optimal kernel regression estimates perform for simple linear, polynomial, and exponential models.
Integrated nanoscale silicon sensors using top-down fabrication

Semiconductor device-based sensing of chemical and biological entities has been demonstrated through the use of micro- and nanoscale field-effect devices and close variants. Although carbon nanotubes and silicon nanowires have been demonstrated as single molecule biosensors, the fabrication methods that have been used for creating these devices are typically not compatible with modern semiconductor manufacturing techniques and their large scale integration is problematic. These shortcomings are addressed by recent advancements in microelectronic fabrication techniques which resulted in the realization of nanowire-like structures. Here we report a method to fabricate silicon nanowires at precise locations using such techniques. Our method allows for the realization of truly integrated sensors capable of production of dense arrays. Sensitivity of these devices to changes in the ambient gas composition is also shown.
Molecular dynamics and NMR studies of single-stranded PNAs

Abstract Proton NMR spectroscopy and molecular dynamics simulations are employed to investigate the conformations of PNA monomers, a dimer and an octamer. The monomers exist as a 70:30 mixture of two amide rotamers interconverting slowly on the NMR time scale at 20 °C. In the major form, the side chain carbonyl group points toward the glycine, which places the methylene protons in proximity to the 2-aminoethyl protons. The minor form places its side chain carbonyl group away from the glycine, and the methylene protons are close in space to the glycine α protons. The PNA CT-dimer has multiple rotamers at 20 °C. In contrast, a NOESY spectrum taken from an octamer indicates only a single conformer in solution at 40 °C.
CD95-mediated apoptosis in naïve, central and effector memory subsets of CD4+ and CD8+ T cells in aged humans

Abstract Aging is associated with a decrease in naive (T N ) and central memory (T CM ), and an accumulation of effector memory (T EM and T EMRA ) T cell subsets. Previously, we have demonstrated an increased sensitivity of T N and T CM CD4+ and CD8+ T cells in aging to TNF-α-induced apoptosis. In this investigation, we examined whether similar differential sensitivity is applicable to CD95-mediated apoptosis. We show that T N and T CM CD4+ and CD8+ T cells from aged subjects are significantly more sensitive to CD95-mediated apoptosis. Increased apoptosis is associated with increased activation of caspase-8 and caspase-3. Both caspase-8 and caspase-3 inhibitors blocked CD95-mediated apoptosis and activation of caspase-8 and caspase-3 in T N and T CM CD4+ and CD8+ T cells. No significant difference was observed in apoptosis or in activation of caspase-8 and caspase-3 in T EM and T EMRA CD4+ and CD8+ T cells between young and aged subjects; both populations were relatively and comparably resistant to CD95-mediated apoptosis and caspase activation. No correlation was observed between the sensitivity/resistance of any of the subsets of CD4+ or CD8+T cells to CD95-mediated apoptosis and the expression of CD95. Our data suggest that increased CD95-mediated apoptosis of T N and T CM CD8+ and CD4+ T cells may play a role in their decline in human aging.
Measurements of the microwave background in Florence, Rome and Berkeley

Abstract Francesco Melchiorri began his scientific career as a condensed matter physicist. In the early 1970s he developed an interest in far infrared astrophysics and especially in measurements of the cosmic microwave background (CMB) radiation. First at Florence and later at Rome, his group made measurements of the spectrum of the CMB, the dipole and smaller scale anisotropies, and of the Sunyaev Zeldovich effect. At every stage of this process there were remarkable parallels between Francesco’s career at Florence and Rome and the Author’s career at Berkeley. This paper in honor of Francesco Melchiorri will describe some of these parallels, focusing on measurements of the CMB.
A spectral characterization of H ∞ -optimal feedback performance and its efficient computation

Abstract We study the spectral properties of a ‘Toeplitz + Hankel’ operator which arises in the context of the mixed-sensitivity H ∞ -optimization problem and whose largest eigenvalue characterizes the optimal achievable performance ϵ 0 . The existence of such an operator was first shown by Verma and Jonckheere [26], who also'noted the potential numerical advantage of computing eo through its eigenvalue characterization rather than through the ϵ-iteration. Here, we investigate this operator in detail, with the objective of efficiency computing its spectrum. We define an ‘adjoint’ linear-quadratic problem that involves the same ‘Toeplitz + Hankel’ operator, as shown by Jonckheere and Silverman [13–16]. Consequently, a finite polynomial algorithm allows ϵ 0 to be characterized as simply as the largest root of a polynomial. Finally, a computationally more attractive state space algorithm emerges from the H t 8 /LQ relationship. This algorithm yields a very good accuracy evaluation of the performance ϵ 0 by solving just one algebraic Riccati equation. Thorough exploitation of this algorithm results in a drastic computation reduction with respect to the standard e-iteration.
New insights from Fanconi anemia

Study of rare genetic diseases often leads to significant advances in the understanding of cancer biology in general. Such is the case for Fanconi anemia (FA), a rare cancer susceptibility syndrome with an incidence of only 1 in 300 000 live births. Two papers in this issue provide new mechanistic
Efficacy of calcium supplements on bone mass in postmenopausal women.

THE consistent loss of bone with age is due to inadequate calcium intake, inadequate calcium absorption or excessive excretory loss, or a combination of these problems. The Institute of Medicine recommends that postmenopausal women should ingest 1,200 mg of calcium daily (1). However, the usual daily intake of calcium for 5O--70-year-old American women is about 600 mg/day (2). Fifty-five percent of these estrogen-deprived women have insufficient absorption to maintain calcium balance at an intake equal to 800 mg/day (3). Nearly one fourth would still be in negative balance at an intake of 1,500 mg/day (3). In spite of the poor absorption and bioavailability of calcium in postmenopausal women, taking calcium supplements seems to be the most convenient, easy, safe, and inexpensive way to achieve the requirement and to help prevent or treat osteoporosis. Calcium supplements are particularly important for women who do not consume a sufficient quantity of dairy products or calcium-rich foods to meet their daily calcium needs. This review will summarize the recent clinical studies of the effects of calcium supplements on bone mass in postmenopausal women, discuss the factors that may influence the effectiveness of calcium supplements in preventing bone loss, and report the safety of calcium supplements.
A Thermal Desorption Chemical Ionization Ion Trap Mass Spectrometer for the Chemical Characterization of Ultrafine Aerosol Particles

The development of a thermal desorption chemical ionization ion trap mass spectrometer for the chemical characterization of ultrafine aerosol particles is reported and first experimental results are presented. Atmospheric particles are size-classified and collected using a unipolar charger, a radial differential mobility analyzer and an electrostatic precipitator, and analyzed after thermal desorption and chemical ionization using an ion trap mass spectrometer. Integration of an ion trap mass spectrometer allows for fast scans of the entire mass spectrum every 0.5 s and bears the potential to identify unknown particulate compounds by tandem mass spectrometry. Particle collection efficiencies range from 90–100% for 25 nm particles to about 50% for 40 nm particles. In the current configuration, the absolute sensitivity of the instrument with regard to ammonium is in the range of 10–100 pg NH + 4 . In ambient samples collected in the Colorado Front Range, NH + 4 was the major signal peak in the positive ion ...
Optical giant resonances in nuclear reactions

Abstract In this paper we discuss the physical reasons for optical giant resonances being a very general feature of nuclear reactions. Optical giant resonances, so familiar in the scattering of nucleons on nuclei, have also been observed in elastic cross sections of composite particles scattered by nuclei and in certain reaction channels of a compound nucleus decay. That one should expect this optical giant resonance structure to occur in such a variety of nuclear reactions is mainly attributed, in our arguments, to the effect of the indistinguishability of the nucleons on the interactions between two proximate nuclear clusters. Because of the indistinguishability of the nucleons, the lifetime of the nuclear clusters in a compound nuclear state can often be prolonged to times, of order 10 −20 to 10 −22 sec, of sufficient duration compared to the transit times to account for the observed resonances. The relationship of the giant resonance structure and the Coulomb barrier is also discussed.
Sexual assault prevalence, reporting and policies: Comparing college and university campuses and military service academies

This article examines differences and similarities between college and university campuses and military service academies on several sexual assault issues. Based on meta-analyses of federal reports, the article provides a comparison of rates of sexual assault, reporting rates and barriers, and policy efforts in each setting. Specific influences on sexual assault incidents and reporting are identified in both settings, including male-dominated cultures as well as specific policies and practices around sexual assault prevention and response. The article concludes with a discussion of the overall implications for women's security on college campuses and at military service academies and recommendations for future research and policy.
Immunophilins, Heat Shock Proteins, and Glucocorticoid Receptor Actionsin Vivo

The glucocorticoid receptor is a member of the steroid/thyroid receptor family and, as such, acts as a ligand-inducible enhancer of specific gene transcription. Many studies have demonstrated thein vitroassociation of steroid receptors with members of both the heat shock and the immunophilin family of proteins. This has led to speculation of a functional convergence in the signal transduction pathways for immunophilins, heat shock proteins, and steroid receptors. In this work, we review the association of heat shock proteins and immunophilins with steroid receptors, with an emphasis on thein vivoeffects of heat shock and immunosuppressive macrolides (FK506, rapamycin, and cyclosporin A) on glucocorticoid receptor transcription enhancement activity.
A complete and extendable approach to visual recognition

A framework for 3D object recognition is presented. Its flexibility and extensibility are accomplished through a uniform, parallel, and modular recognition architecture. Concurrent and stacked parameter transforms reconstruct a variety of features from the input scene. At each stage, constraint satisfaction networks collect and fuse the evidence obtained through the parameter transforms, ensuring a globally consistent interpretation of the input scene and allowing for the integration of diverse types of information. The final interpretation of the scene is a small consistent subset of the many initial hypotheses about partial features, primitive features, feature assemblies, and 3D objects computed by the various parameter transforms. A complete, integrated, and implemented system that extracts planar surfaces, patches of quadrics of revolution, and planar intersection curves of these surfaces from a depth map viewing 3D objects is described. Experimental results on the recognition behavior of the system are presented. >
Single crystals of a chimeric T7/T3 RNA polymerase with T3 promoter specificity

Abstract Two RNA polymerases homologous to bacteriophage T7 RNA polymerase - bacteriophage Sp6 and T3 RNA polymerases - were screened for crystallization under conditions identical or similar to those reported for the growth of large single crystals of T7 RNA polymerase. A number of mutant T7 RNAPs were also screened under these conditions, as were three chimeric RNA polymerases consisting of T7 RNAP N-terminal and T3 RNAP C-terminal sequences. One chimeric polymerase and two mutant polymerases crystallized readily under T7 RNAP crystallization conditions. The chimeric polymerase crystallized in a space group different from T7 RNA polymerase: orthorhombic with unit cell parameters a = 75A˚, b = 98A˚, c = 159A˚; space group P2 1 2 1 2 1 and 4 molecules per unit cell. This chimeric enzyme exhibits T3 promoter specificity and will make it possible to investigate how structural differences between the T3 and T7 RNA polymerase promoter recognition domains determine their different promoter specificities.
Kinetics of decomposition of the fluorosulphate ion in aqueous solution

Abstract The rate of decomposition of the fluorosulphate ion(SO3F−) has been determined in aqueous solution under conditions ranging from 4 M hydrochloric acid to 5 M sodium hydroxide. The empirical rate law found for this process is: −d[ SO 3 F - ] dt ={ k[H + ]+ k h20 + k 1 [ OH - ]}[ SO 3 F - ] . The activation energies for all steps can be estimated, and elementary processes consistent with such a rate law are presented.
Possible representation errors in inversions of satellite CO2 retrievals

[1] Owing to global spatial sampling and sheer data volume, satellite CO2 concentrations can be used in inverse models to enhance our understanding of the carbon cycle. Using column measurements to represent a transport model grid column may introduce spatial, local clear-sky, and temporal sampling errors into inversions: the footprint is smaller than a grid cell, total column concentrations are only retrieved in clear skies, and the mixing ratios are only sampled at one time. To investigate these errors, we used a coupled ecosystem-atmosphere cloud-resolving model to create CO2 fields over fine (∼1° × 1°) and coarse (∼4° × 4°) grid columns from 1 km2 and 25 km2 pixels that utilized explicit microphysics. We performed two simulations in August 2001: one in central North America and one in the Brazilian Amazon. Differences between satellite and grid column concentrations were calculated by subtracting the domain mean column concentration from 10-km-wide simulated satellite measurements. Spatial and local clear-sky errors were less than 0.5 ppm for the fine grid column; however, these errors became large and biased over the coarse grid column in North America. To avoid these errors, transport models should be run at high resolution. Using satellite measurements to represent bimonthly averages created large (>1 ppm) errors for all cases. The errors were negatively biased (approximately −0.4 ppm) in the North American simulation, indicating that inverse models cannot use satellite measurements to represent temporal averages. Simulated representation errors did not arise because of differences in ecosystem metabolism in cloudy versus sunny conditions; rather, they reflected large-scale CO2 gradients in midlatitudes that were organized along frontal boundaries and masked under regional cloud cover. Such boundaries were not found in the dry-season tropical simulation presented here and may be less prevalent in the tropics in general. To avoid incurring errors, inversions must accurately model synoptic-scale atmospheric transport and CO2 concentrations must be assimilated at the time and place observed.
PageSpark: an E-magazine reader with enhanced reading experiences on handheld devices

In this paper we present PageSpark, a system that automatically converts static magazine content to interactive and engaging reading apps on handheld reading devices. PageSpark enhances the reading experience in three general aspects: page layout reorganization, page element interactions and page transitions. We explored and implemented several design variations in each aspect with the prototype running on the iPad. Participants from our initial user study showed strong interest of using PageSpark over existing magazine reading apps.
A Sensitive and Versatile Detector for Atmospheric NO2 and NOX Based on Blue Diode Laser Cavity Ring-Down Spectroscopy

A sensitive, small detector was developed for atmospheric NO2 and NOx concentration measurements. NO2 is directly detected by laser diode based cavity ring-down spectroscopy (CRDS) at 404 nm. The sum of NO and NO2 (=NOx) is simultaneously measured in a second cavity by quantitative conversion of ambient NO to NO2 in excess ozone. Interferences due to absorption by other trace gases at 404 nm, such as ozone and water vapor, are either negligible or small and are easily quantified. The limit of detection is 22 pptv (2σ precision) for NO2 at 1 s time resolution. The conversion efficiency of NO to NO2 is 99% in excess O3. The accuracy of the NO2 measurement is mainly limited by the NO2 absorption cross section to ±3%. Because of the formation of undetectable higher nitrogen oxides in subsequent reactions of NO2 with ozone in the NOx channel, the (1σ) accuracy of the NOx measurement is increased to approximately ±5% depending on the level of NOx. The new instrument was designed to be easily deployed in the fie...
Immunotherapy with antigen E.

Abstract Ragweed-sensitive patients were treated for 4 years with antigen E, a purified ragweed fraction. The over-all results, including a double blind study and crossover studies, suggested that antigen E was not as clinically effective as whole ragweed pollen extract. Antigen E was well tolerated, allowing administration of relatively large doses with few local and systemic reactions. In vivo reagin neutralization studies also suggested that some allergens had been lost in the preparation of Antigen E. Antigen E was highly antigenic, stimulating high titers of hemagglutinating antibodies, and precipitins could be demonstrated in some sera. Antigen E appears to be an important component of ragweed pollen. However, other allergenic fractions may also be necessary in order to provide optimal clinical results.
Comparative analysis of the cellular and Johnson-Mehl microstructures through computer simulation

Abstract The geometric properties of polygranular microstructures of the Johnson-Mehl cellular types have been studied through computer simulation. These prototypic microstructures arise naturally from the classical model of a phase transformation in a one-component solid through growth from a random distribution of nucleation sites. The Johnson-Mehl microstructure results in the kinetic limit of a constant nucleation rate over an essentially constant density of available nucleation sites; the cellular microstructure is produced in the kinetic limit of simultaneous activation of the available nucleation sites. Members of each of these microstructure types are similar to one another in all aspects of their geometrical statistics; they differ only through a homogeneous expansion or contraction. Their geometric features have been characterized through a combination of analytic and computer simulation studies. Comparison with available experimental results shows that the Johnson-Mehl microstructure compares well with such metallurgically diverse experimental structures as the crystallization structure of silicon iron and the intermediate structures established during the ordering of lithium ferrite. These correspondences suggest that the idealized microstructures studied here may be physically relevant as well as being pedagogically useful.
The Effects of Reservoir Minerals on the Composition Changes of Heavy Oil During Steam Stimulation

The catalytic effect of minerals on the hydrocarbon groups, viscosity, and element distribution of heavy oil during the thermal recovery process studied are in this paper. The results show that minerals have a catalytic effect in the aquathermolysis of heavy oil. When 10%wt mineral was added to the reaction system, the saturate and aromatic content increased, while the resins and asphaltenes components decreased. The results also show that the average molecular weight of heavy oil and asphaltene was reduced after treatment, and the content of sulphur decreased. The viscosity of the heavy oil used in our study decreased by 23.4-25.6% in the reaction system after treatment with steam.
Global transverse momentum analysis for Ar+KCl and Ar+ BaI 2 at 1.2 GeV/nucleon

High multiplicity collisions of 1.2 GeV/nucleon /sup 40/Ar on Kcl and on BaI/sub 2/ in the Bevalac streamer chamber are studied using the global transverse momentum analysis introduced by Danielewicz and Odyniec. For both systems, there is a sideward flow which is significantly larger than intranuclear cascade model predictions. The current results permit a study of trends in the multiplicity, mass and energy dependence of the observed flow signatures. Estimates of the stiffness of the nuclear equation of state at high density are discussed.
Azimuthal Correlations in pp Interactions at 205 GeV/c

Using data obtained from an exposure of the 30-in. Fermi National Accelerator Laboratory bubble chamber to a 205-GeV/c proton beam, results are presented on azimuthal distributions. Evidence is presented for dynamical azimuthal correlations whose behavior depends on the particular charge combination. The dependence of the azimuthal correlations on the rapidity difference and on the transverse momentum is also given.
Wetting in random systems.

Complete wetting and critical wetting transitions are studied in d-dimensional systems with quenched random impurities and general interactions. New but more universal singular behavior is predicted: e.g., under random fields the wetting-layer thickness at complete wetting should diverge as ${\mathrm{h}}^{\mathrm{\ensuremath{-}}1/2}$ for d=3, where h measures the deviation from the bulk-phase boundary. Wetting exponents are expressed in terms of a single spatial anisotropy or roughness exponent, \ensuremath{\zeta}, defined via ${\ensuremath{\xi}}_{\mathrm{\ensuremath{\perp}}}$\ensuremath{\sim}${\ensuremath{\xi}}_{\mathrm{?}}^{\mathrm{\ensuremath{\zeta}}}$ where ${\ensuremath{\xi}}_{\mathrm{\ensuremath{\perp}}}$ and ${\ensuremath{\xi}}_{\mathrm{?}}$ are the wetting correlation lengths.
Weather radar equation correction for frequency agile and phased array radars

This paper presents the derivation of a correction to the Probert-Jones weather radar equation for use with advanced frequency agile, phased array radars. It is shown that two additional terms are required to account for frequency hopping and electronic beam pointing. The corrected weather radar equation provides a basis for accurate and efficient computation of a reflectivity estimate from the weather signal data samples. Lastly, an understanding of calibration requirements for these advanced weather radars is shown to follow naturally from the theoretical framework.
Collimator optimization in SPECT based on a joint detection and localization task.

In SPECT the collimator is a crucial element of the imaging chain and controls the noise-resolution tradeoff of the collected data. Optimizing collimator design has been a long studied topic, with many different criteria used to evaluate the design. One class of criteria is task based, in which the collimator is designed to optimize detection of a signal (lesion). Here we consider a new, more realistic task, the joint detection and localization of a signal. Furthermore, we use an ideal observer—one that attains a theoretically maximum task performance—to optimize collimator design. The ideal observer operates on the sinogram data. We consider a family of parallel-hole low-energy collimators of varying resolution and efficiency and optimize over this set. We observe that for a 2D object characterized by noise due to background variability and a sinogram with photon noise, the optimal collimator tends to be of lower resolution and higher efficiency than equivalent commercial collimators. Furthermore, this optimal design is insensitive to the tolerance radius within which the signal must be localized. So for this scenario, the addition of a localization task does not change the optimal collimator. Optimal collimator resolution gets worse as signal size grows, and improves as the level of background variability noise increases. These latter two trends are also observed when the detection task is signal-known-exactly and background variable.
Hepatitis C viral life cycle

Hepatitis C virus (HCV) has been recognized as a major cause of chronic liver diseases worldwide. Molecular studies of the virus became possible with the successful cloning of its genome in 1989. Although much work remains to be done regarding early and late stages of the HCV life cycle, significant progress has been made with respect to the molecular biology of HCV, especially the viral protein processing and the genome replication. This review summarizes our current understanding of genomic organization of HCV, features of the viral protein characteristics, and the viral life cycle.
Curie-Point Pyrolysis of Cellulose

Microcrystalline cellulose was pyrolysed using a Curie-point pyrolyser, directly attached to a GLC apparatus, at 460°C for 5 sec under a neat condition without any additives. Although the total yield of organic volatile fraction was not so high, 2-furaldehyde and levoglucosenone were observed as the major components in this fraction. Another volatile product, 1,6-anhydro-3-deoxy-β-D-glucopyranosen, was also identified as the intermediate between levoglucosan and levoglucosenone. Levoglucosan could not be directly detected by the pyrolysis—GLC technique because of its low volatility, but it was thought to be one of the major components of the tar produced. Only slight amounts of these anhydro sugar homologues were observed in the Curie-point pyrolysis with D-glucose, cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose, though furans were abundantly observed in the volatile fractions. These results suggest the following two paths for the thermal decomposition reaction of cellulose at the initial stage:Cellulose→Levoglucosan, 1,6-anhydro-3-deoxy-β-D-glucopyranosen, and levoglucosenoneCellulose→5-Hydroxymethyl-2-furaldehyde, 2-furaldehyde, and other furan compounds
A theoretical study of non-equilibrium blunt-body flows

Non-equilibrium inviscid flows behind a spherical-segment shock wave are investigated with the method of series truncation. This semi-analytical technique developed at Stanford is based on a systematic co-ordinate-perturbation scheme. The flow variables are expanded in series in powers of the longitudinal curvilinear co-ordinate leading away from the stagnation point. The problem is thus reduced to one of numerical integration of ordinary differential equations for functions of the normal co-ordinate. Unlike the similar situation of the Blasius series in boundary-layer theory, the present scheme–having to deal with elliptic equations–must resort to series truncation. As a consequence, a truncation error is introduced. The present paper shows a simple way of reducing this error.The simplified air chemistry adopted is based on non-equilibrium dissociation and recombination of oxygen diluted in inert nitrogen. A wide spectrum of non-equilibrium regimes is investigated for a fixed set of flight conditions. In particular, near-frozen flows are followed to the vicinity of the stagnation point through a region of large temperature and concentration gradients located near the body. This equilibrium-drive region, arising from the singular nature of the frozen limit, is studied in some detail.
Chemical transformation of toxic metals by a Pseudomonas strain from a toxic waste site

Pseudomonas maltophilia strain O-2, isolated from soil at a toxic waste site in Oak Ridge, Tennessee, catalyzed the transformation and precipitation of numerous toxic metal cations and oxyanions. When a viable inoculum (1%) of O-2 was introduced into nutrient broth containing Hg(II), Cr(VI), Se(IV), Pb(II), Au(III), Cd(II), Te(IV), or Ag(I), effective removal of the toxic metal was complete within 1, 1, 2, 2, 2, 4, 5, and 7 d, respectively. The NADPH-dependent reduction of Hg(II) to Hg0 was catalyzed by an inducible mercuric reductase. The reduction of selenite and tellurite to their insoluble elemental forms appeared to be mediated by an intracellular glutathione reductase that utilized the spontaneously formed bis(glutathio)Se(II) or bis(glutathio)Te(II), respectively, as pseudosubstrates. The three-electron reduction of hexavalent chromium was catalyzed by a membrane-bound chromate reductase. The enzymatic basis for the remaining metal transformations was not immediately apparent. It is anticipated that Pseudomonas maltophilia and related organisms could eventually be exploited for the removal of toxic metal wastes from selected, heavily polluted sites.
Optical isolators based on surface magneto plasmon polaritons

Strong nonreciprocal phase shift is attainable when plasmon polariton propagates on the interface between metal and magneto-optical material in presence of transverse magnetic field. This effect is a basis for short low loss nanoplasmonic isolators.
An introduction to factor VIII inhibitors: the detection and quantitation.

Spontaneous development of autoantibodies against factor VIII:C (FVIII:C) protein in a nonhemophiliac is a rare but significant clinical occurrence that frequently is associated with life-threatening hemorrhagic complications. These autoantibodies often arise as an epiphenomenon of various disease states that are autoimmune or manifest a component of immune dysfunction. The present symposium reviews the immunochemistry of FVIII:C autoantibodies and describes ways in which this knowledge has been applied to gain insight into the structure-function relationship of the FVIII:C protein. Also discussed are the etiology and natural history of acquired FVIII:C inhibition as well as evolving approaches to its treatment. Therapeutic options for this condition continue to expand, and choice of the optimal regimen for each patient is based on many considerations, including the level of the inhibitor, the underlying disease state, clinical responses to previous treatment, and degree of antibody interaction with heterologous purified FVIII:C protein. Acquired FVIII:C autoantibodies isolated from nonhemophiliacs are characterized as heterogeneous, noncomplement-fixing, nonprecipitating immunoglobulins directed against functional epitopes (antigenic sites) of FVIII:C in a time- and temperature-dependent manner. The clinical significance of these inhibitors is determined qualitatively by studying in vivo survival of FVIII:C activity with infused replacement materials or quantitatively by laboratory mixing tests that measure the capacity of the inhibitor to neutralize FVIII:C activity. In the United States inhibitor potency is expressed most commonly in Bethesda Units (BU), where 1.0 BU is the reciprocal dilution of patient test plasma, permitting detection of 50% residual FVIII:C activity in a mixture with normal pooled plasma. In Europe, FVIII inhibitors are now often quantitated in New Oxford Units, which are derived from neutralizing-mixing studies of patient test plasma with diluted FVIII concentrate. One Oxford unit is equivalent to approximately 0.83 BU. Although analyses that measure functional inhibition of FVIII:C activity by the autoantibody provide a useful tool to assess clinical efficacy of therapeutic regimens, these assays may not recognize nonactivating antibodies. These immunoglobulins may bind to alternative epitopes and significantly influence plasma clearance, survival times, and circulating levels of infused FVIII:C protein. Finally, this symposium will speculate on the potential application of innovative approaches to inhibitor therapy, based on results from numerous provocative studies on the nature of the human immune response.
Purification and characterization of a flavin-binding storage protein from the hemolymph of Galleria mellonella

The 85K storage protein that accumulates in the hemolymph of Galleria mellonella during the final larval instar was isolated and purified from newly molted pupae. The separation of fresh hemolymph proteins from larvae or pupae by different chromatographic and electrophoretic procedures indicated the native protein had a M(r) of 170,000 and consisted of two identical 85K subunits. Crosslinking experiments using fresh hemolymph followed by Western blotting also indicated a dimeric structure for the native protein. Analyses of the dimer purified from pupal hemolymph indicated that 85K was a glycoprotein, containing approximately 6.5% neutral sugar and about 1.9% amino sugar. Like other insect flavin-binding proteins, 85K has a relatively high histidine content but an uncharacteristically high arginine content. The purified 85K dimer did not bind riboflavin, suggesting that the integrity of the molecule had been altered during purification. However, 85K purified in low yield by Affi-Gel Blue chromatography, did bind riboflavin, indicating that under certain, undefined conditions the functional integrity of the protein could be retained during purification.
Influence of food quality on growth and reproduction in Daphnia

SUMMARY. 1. Growth and reproduction were measured for Daphnia pulex (Leydig) fed Scenedesmus obliquus (Turp.) Kutz. grown with nitrogen-sufficient and nitrogen-deficient media. The incorporation of carbon into the body of D. pulex was traced using 14C-labelled algae and biochemical fractionation. 2. Scenedesmus cultured on N-defkient media allocated more carbon to lipid and less to protein than when cultured on N-sufficient media. 3. In a short-term feeding experiment, Daphnia accumulated more lipid when fed N-deficient algal cells high in lipid content than when fed algae grown on N-sufficient media that were lower in lipid. 4. Animals grew faster and produced larger broods when fed algae grown on an N-sufficient medium over an 8-day period. Daphnids fed N-deficient algae had higher quantities of body lipid, suggesting it was not a lack of energy which limited their growth and reproduction. 5. Daphnia fed algae grown on N-deficient media allocated more lipid to eggs, and their offspring lived longer under starvation conditions.
Estimating population size and transmission bottlenecks in maternally transmitted endosymbiotic bacteria.

Many species of bacterial endosymbionts are acquired by animal hosts before birth, through direct transmission from mothers to eggs or embryos. This vertical transmission imposes a reduction in numbers or "bottleneck," and the size of this bottleneck affects the population structure and evolution of symbiotic lineages. We have estimated the size of the transmission bottleneck in Buchnera, the bacterial symbiont of aphids, using basic light and electron microscopy techniques. By serial-sectioning whole aphid abdomens, their eggs, and embryos, we determined the following parameters: (i) The average size of a Buchnera cell is 2.9 mm in diameter. (ii) The total number of Buchnera in an Acyrthosiphon pisum embryo was around 36,700 whereas a first instar nymph contained more than 119,000. (iii) The number of symbionts per bacteriocyte was around 800 in an embryo and 3200 in a first instar nymph. (iv) The total number of Buchnera transmitted to each sexual egg ranged from 850 in Nasonovia to 1800 in A. pisum to more than 8000 in Uroleucon ambrosiae. (v) The total number of secondary endosymbionts in A. pisum was 12,170 for an embryo and 18,360 for a first instar nymph. Secondary symbionts were arranged both extracellularly and in clusters of 2000–8000 bacteria inside bacteriocytes. These numbers are consistent with the few previous estimates of symbiont population sizes based on counts of gene copies.
Federalism as a Commitment to Reserving Market Incentives

The authors advance a new perspective in the study of federalism. Their approach views federalism as a governance solution of the state to credibly preserving market incentives. Market incentives are preserved if the state is credibly prevented from compromising on future economic success and from bailing out future failures. The salient features of federalism--decentralization of information and authority and interjurisdictional competition--help provide credible commitment or these purposes. In addition, the authors suggest that some federalism are self-sustaining.
Estimation of brachial artery volume flow by duplex ultrasound imaging predicts dialysis access maturation.

Objective This study validated duplex ultrasound measurement of brachial artery volume flow (VF) as predictor of dialysis access flow maturation and successful hemodialysis. Methods Duplex ultrasound was used to image upper extremity dialysis access anatomy and estimate access VF within 1 to 2 weeks of the procedure. Correlation of brachial artery VF with dialysis access conduit VF was performed using a standardized duplex testing protocol in 75 patients. The hemodynamic data were used to develop brachial artery flow velocity criteria (peak systolic velocity and end-diastolic velocity) predictive of three VF categories: low ( 800 mL/min). Brachial artery VF was then measured in 148 patients after a primary (n = 86) or revised (n = 62) upper extremity dialysis access procedure, and the VF category correlated with access maturation or need for revision before hemodialysis usage. Access maturation was conferred when brachial artery VF was >600 mL/min and conduit imaging indicated successful cannulation based on anatomic criteria of conduit diameter >5 mm and skin depth Results Measurements of VF from the brachial artery and access conduit demonstrated a high degree of correlation ( R 2 = 0.805) for autogenous vein (n = 45; R 2 = 0.87) and bridge graft (n = 30; R 2 = 0.78) dialysis accesses. Access VF of >800 mL/min was predicted when the brachial artery lumen diameter was >4.5 mm, peak systolic velocity was >150 cm/s, and the diastolic-to-systolic velocity ratio was >0.4. Brachial artery velocity spectra indicating VF P 800 mL/min. Duplex testing to estimate brachial artery VF and assess the conduit for ease of cannulation can be performed in 5 minutes during the initial postoperative vascular clinic evaluation. Conclusions Estimation of brachial artery VF using the duplex ultrasound, termed the "Fast, 5-min Dialysis Duplex Scan," facilitates patient evaluation after new or revised upper extremity dialysis access procedures. Brachial artery VF correlates with access VF measurements and has the advantage of being easier to perform and applicable for forearm and also arm dialysis access. When brachial artery velocity spectra criteria confirm a VF >800 mL/min, flow maturation and successful hemodialysis are predicted if anatomic criteria for conduit cannulation are also present.
Fluorescence properties of fluoranthene as a function of temperature and environment

Abstract The fluoranthene fluorescence properties were investigated in a variety of environments, i.e. in different solvents and temperatures, in the solid state, and in the vapor phase. The emission maximum was found to be independent of environment. The absorption spectrum in different solvents exhibits only minor changes. In solution, the fluorescence lifetime shows a slight inverse relationship to the solvent dielectric constant. With water/methanol mixtures of varying composition as the solvent, the lifetime decreases linearly with increasing mole fraction of water. At 77K, the fluoranthene fluorescence lifetime in frozen polar and nonpolar solvents are the same within experimental error. In hexane the fluorescence lifetime is independent of temperature (77±3 and 82±7 ns, at room temperature and 77 K, respectively). In methanol the lifetime is 64±3 ns at room temperature and increases linearly to 80±4 ns at 77 K. In the vapor phase the lifetime is 32±1 ns. No fluorescence quantum yield change was observed for either S1 or S2 manifold excitation.
The toxicity of plant alkaloids: an Ecogeographic perspective

Abstract The toxicity of alkaloids was sought in relation to the geography of alkaloid-bearing plants. Relative toxicity was inferred from the structure of the compounds, which exhibit regular structure-activity relationships. The toxicity of alkaloids from tropical plants is much greater than those from temperate plants. No significant differences were found between herbaceous and woody plants. The alkaloid content of leaves tends to be a positive function of alkaloid toxicity. The ecogeographical distribution of toxicity is interpreted in terms of plant defense.
Uterine papillary serous carcinoma evolves via a p53-driven pathway

Uterine papillary serous carcinoma (UPSC) is a highly aggressive type of endometrial cancer that occurs in the absence of hyperestrogenism and endometrial hyperplasia. Biologically, UPSC belongs to a distinct group of aggressive neoplasms of the extended Mullerian epithelium that are characterized by hypoestrogenism, advanced disease at diagnosis, a serous papillary histotype, and a dismal prognosis. There is mounting evidence that loss of p53 function is critical for the molecular genetic cause of all tumors in this group. To further assess the role of p53 alterations in UPSC, we studied 40 patients using immunohistochemical expression analysis. Thirty-four tumors (85%) showed intense nuclear overexpression of p53, whereas six tumors (15%) were p53 negative. Thirteen p53-positive tumors had multiple samplings from distinct anatomic sites, and all showed complete concordance in p53 staining, suggesting that p53 alterations occur early in UPSC carcinogenesis. p53 positivity was associated with loss of hormone receptors. Thirty-nine cases were concomitantly analyzed for estrogen or progesterone receptor expression. Among those, 31 tumors were p53 positive but hormone receptor negative throughout, in contrast to only two tumors that were diffusely p53 positive and focally hormone receptor positive. Patients whose tumors overexpressed p53 had a statistically significant shorter survival than those whose tumors did not at 24 and 48 months (P = .03). This study represents one of the two largest analyses published to date that confirm the strong association between UPSC and p53 overexpression. Furthermore, we suggest that the concept of UPSC be broadened: UPSC is a p53-driven neoplasm that biologically is a kin to other serous papillary malignancies of the ovaries and peritoneum. This group of tumors bypasses the slow hormone-dependent pathway of tumorigenesis but instead undergoes early p53 alterations that lead to rapid tumor development.
Loss allocation control in power distribution system reconfiguration in the presence of distributed generators

In a deregulated power distribution system with distributed generation, end users should be allocated the appropriate cost of energy transactions for fair and effective operation. One of the common practices is to allocate the cost of power losses to distributed generators (DGs) and consumers based on their effective share. According to the network configuration, DGs and consumers could have positive or negative impacts on a system's overall loss. This paper addresses the effect of power distribution system reconfiguration on each user's share of loss. The overall system loss and maximum allocated loss are considered in the two competing objectives to be minimized. The branch current decomposition method is used to calculate the allocated losses to each bus. The group search optimizer (GSO), a swarm intelligence optimization method, is used to find the best solution. Using weighted factors, the priorities of decision-makers are applied to the optimization problem. A 33-bus distribution system is used for which the best possible configuration is found.