cssi/SciSciGPT-SciSciNet huggingface dataset:
Improved crystallization of Escherichia coli ATP synthase catalytic complex (F1) by introducing a phosphomimetic mutation in subunit ε.

The bacterial ATP synthase (FOF1) of Escherichia coli has been the prominent model system for genetics, biochemical and more recently single-molecule studies on F-type ATP synthases. With 22 total polypeptide chains (total mass of ∼529 kDa), E. coli FOF1 represents nature's smallest rotary motor, composed of a membrane-embedded proton transporter (FO) and a peripheral catalytic complex (F1). The ATPase activity of isolated F1 is fully expressed by the α3β3γ `core', whereas single δ and ∊ subunits are required for structural and functional coupling of E. coli F1 to FO. In contrast to mitochondrial F1-ATPases that have been determined to atomic resolution, the bacterial homologues have proven very difficult to crystallize. In this paper, we describe a biochemical strategy that led us to improve the crystallogenesis of the E. coli F1-ATPase catalytic core. Destabilizing the compact conformation of ∊'s C-terminal domain with a phosphomimetic mutation (∊S65D) dramatically increased crystallization success and reproducibility, yielding crystals of E. coli F1 that diffract to ∼3.15 A resolution.
Gender Differences in Cerebral Blood Flow and Oxygenation Response during Focal Physiologic Neural Activity

Using functional magnetic resonance imaging techniques CBF and oxygenation changes were measured during sustained checkerboard stimulation in 38 right-handed healthy volunteers (18 men and 20 women). The average blood oxygenation level dependent (BOLD) contrast technique signal intensity change was 1.67 +/- 0.6% in the group of male volunteers and 2.15 +/- 0.6% in the group of female volunteers (P < .05). Baseline regional CBF (rCBF) values in activated gray matter areas within the visual cortex were 57 +/- 10 mL x 100 g(-1) x min(-1) in women and 50 +/- 12 mL x 100 g(-1) x min(-1) in men, respectively (P = .09). Despite a broad overlap between both groups the rCBF increase was significantly higher in women compared to men (33 +/- 5 mL x 100 g(-1) x min(-1) versus 28 +/- 4 mL x 100 g(-1) x min(-1), P < .01). The increase of rCBF was not correlated with the baseline rCBF (mL x 100 g(-1) x min(-1)) (r(s) = 0.01, P = .9). Moreover, changes of rCBF were not correlated with changes in BOLD signal intensities (r(s) = 0.1, P = .7). Enhanced rCBF response in women during visual stimulation could be related to gender differences in visual physiology or may reflect gender differences in the vascular response to focal neuronal activation. Gender differences must be considered when interpreting the results of functional magnetic resonance imaging studies.
Unsupervised Conversion of 3D Models for Interactive Metaverses

A virtual-world environment becomes a truly engaging platform when users have the ability to insert 3D content into the world. However, arbitrary 3D content is often not optimized for real-time rendering, limiting the ability of clients to display large scenes consisting of hundreds or thousands of objects. We present the design and implementation of an automatic, unsupervised conversion process that transforms 3D content into a format suitable for real-time rendering while minimizing loss of quality. The resulting progressive format includes a base mesh, allowing clients to quickly display the model, and a progressive portion for streaming additional detail as desired. Sirikata, an open virtual world platform, has processed over 700 models using this method.
Gibberellin Action on Growth of Seedlings in the Absence of Photosynthesis

A MAJOR effect of gibberellins on growing seedlings is often an increased dry weight, especially in the shoots growing in the light1. These and other observations have frequently led to suggestions that this particular gibberellin effect may be related to an increased photosynthetic carbon-fixation. We have found, however, that in light-grown seedlings that are prevented (by darkness) from performing photosynthesis, gibberellic acid can increase their dry weight over water-control seedlings. The effect of gibberellic acid in these experiments thus cannot be attributed to either direct or indirect actions on photosynthetic fixation.
Gastric linitis plastica from metastatic breast carcinoma: FDG and FES PET appearances.

WEB This is a Web exclusive article. astric linitis plastica is defined as diffuse thickening and rigidity of the gastric wall resulting from inflammation and fibrosis. The most common cause is gastric adenocarcinoma infiltrating the submucosa and muscularis propria and the desmoplastic reaction it incites [1]. Although rare, hematogenous dissemination of infiltrating lobular carcinoma of the breast is the most common metastatic cause of gastric linitis plastica [1, 2]. PET using 2-[18F]fluoro-2-deoxy-D-glucose (FDG) has become an important tool for staging breast carcinoma and monitoring response to therapy [3–5]. In addition, PET of estrogen receptor (ER)–positive breast neoplasms with 16α-[18F]-17β-fluoroestradiol (FES) has shown promise as an investigational approach for measuring regional ER expression and changes in estradiol binding in response to hormonal therapy [3, 4, 6]. We present a case of gastric linitis plastica resulting from metastatic lobular carcinoma of the breast with FDG and FES PET findings.
The statistical correlation between rotation and translation: implications for fine and hyperfine structure in quantum mechanics

Abstract For matrix isolated small molecules such as hydrogen deuteride (HD) the rotational spectra generated form the Schrodinger equation are perturbed by mixing with quantised translational lines which appear from the periodicity imposed by a solvent cage on the motion of the encaged HD molecule. The effect of the mixing of rotational and translational wave functions is that quantum translation/rotation effects occur in the final spectrum. There are shifts in rotational levels, broadening of rotational levels, and relaxation of rotational selection rules. In this paper it is shown that the existence of various new types of cross-correlation function in the laboratory and moving frames of reference implies the existence of new types of fine and hyperfine structure in the infra red spectrum of HD encaged in solvent molecules such as liquid argon. These new features could lead to specific and observable information on the nature of rotation to translation coupling in the liquid state of matter.
Analysis of scheduling policies under correlated job sizes

Correlations in traffic patterns are an important facet of the workloads faced by real systems, and one that has far-reaching consequences on the performance and optimization of the systems involved. However, all the existing analytical work on understanding the effect of correlations between successive service requirements (job sizes) is limited to First-Come First-Served scheduling. This leaves open fundamental questions: How do various scheduling policies interact with correlated job sizes? Can scheduling be used to mitigate the harmful effects of correlations? In this paper we take the first step towards answering these questions. Under a simple model for job size correlations, we present the first asymptotic analysis of various common size-independent scheduling policies when the job size sequence exhibits high correlation. Our analysis reveals that the characteristics of various scheduling policies, as well as their performance relative to each other, are markedly different under the assumption of i.i.d. job sizes versus correlated job sizes. Further, among the class of size-independent scheduling policies, there is no single scheduling policy that is optimal for all degrees of correlations and thus any optimal policy must learn the correlations. We support the asymptotic analysis with numerical algorithms for exact performance analysis under an arbitrary degree of correlation, and with simulations. Finally, we verify the lessons from our correlation model on real-world traces.
Relation between trophic position and mercury accumulation among fishes from the Tongue River Reservoir, Montana

Abstract Concentrations of total mercury were determined in muscle tissue from northern pike (Esox lucius), sauger (Stizostedion canadense), walleye (S. vitreum), black crappie (Pomoxis nigromaculatus), and white crappie (P. annularis) collected from the Tongue River Reservoir, Montana, prior to extensive surface coal-mine development in the region. Mercury concentrations in fish flesh increased with fish size and age; larger individuals of all five species exceeded the U.S. Food and Drug Administration's mercury concentration guideline of 0.5 μg/g. The rate of mercury accumulation was faster in the piscivorous species (northern pike, saugers, and walleyes) than in the planktivores (black crappies and white crappies). Differences in mercury uptake rates among the various species appeared to be directly related to the quantity of mercury eaten: results are discussed in relation to published models of mercury accumulation by fishes.
Coincidental Alignment of Extracorporeal Oxygenator Cannula and Central Venous Catheter

A56-year-old woman who had undergone a Heartmate II left ventricular assist device implant (Thoratec Corp, Pleasanton, CA) as destination therapy 2 years prior, presented in acute cardiogenic shock from a device malfunction. She was emergently placed on a venoarterial extracorporeal membrane oxygenator (ECMO) through the right femoral vessels. Large amounts of air were entrained into the ECMO circuit during an exchange of infusion tubing connected to the central venous catheter located in the right internal jugular vein. A chest roentgenogram (Fig 1) and expanded view (Fig 2) demonstrate the right internal jugular vein catheter (CVC) overlying the venous cannula (ECMO) in the superior vena cava (arrows). Also seen is the Heartmate II pump (HM) (Thoratec Corp), a trans-
The Big Questions of Public Administration Education

Following Behn's observation that scientists in other fields understand the big questions of their disciplines and focus attention and their discussions on those questions, public administration scholars have attempted to identify the “big questions” in public management and public administration. In this article, I suggest that scholars in public administration should also be attentive to the big questions of public administration education, those timeless and enduring concerns that speak to the basic perspectives that we bring to the educational process. Specifically, I identify four big questions: Do we seek to educate our students with respect to theory or to practice? Do we prepare students for their first jobs or for those to which they might aspire later? What are the appropriate delivery mechanisms for MPA courses and curricula? What personal commitments do we make as public administration educators? I argue that these big questions in public administration education are far more connected than we usually think, and by posing these questions in terms of processes of human development we can at least provide a framework through which we might develop more coherent answers to these big questions, answers that recognize and build on the diversity of our students and our faculty.
Heterointerface engineered electronic and magnetic phases of NdNiO 3 thin films

Mott physics is characterized by an interaction-driven metal-to-insulator transition in a partially filled band. In the resulting insulating state, antiferromagnetic orders of the local moments typically develop, but in rare situations no long-range magnetic order appears, even at zero temperature, rendering the system a quantum spin liquid. A fundamental and technologically critical question is whether one can tune the underlying energetic landscape to control both metal-to-insulator and Neel transitions, and even stabilize latent metastable phases, ideally on a platform suitable for applications. Here we demonstrate how to achieve this in ultrathin films of NdNiO3 with various degrees of lattice mismatch, and report on the quantum critical behaviours not reported in the bulk by transport measurements and resonant X-ray spectroscopy/scattering. In particular, on the decay of the antiferromagnetic Mott insulating state into a non-Fermi liquid, we find evidence of a quantum metal-to-insulator transition that spans a non-magnetic insulating phase.
Toward Low-Cost Affinity Reagents: Lyophilized Yeast-scFv Probes Specific for Pathogen Antigens

The generation of affinity reagents, usually monoclonal antibodies, remains a critical bottleneck in biomedical research and diagnostic test development. Recombinant antibody-like proteins such as scFv have yet to replace traditional monoclonal antibodies in antigen detection applications, in large part because of poor performance of scFv in solution. To address this limitation, we have developed assays that use whole yeast cells expressing scFv on their surfaces (yeast-scFv) in place of soluble purified scFv or traditional monoclonal antibodies. In this study, a nonimmune library of human scFv displayed on the surfaces of yeast cells was screened for clones that bind to recombinant cyst proteins of Entamoeba histolytica, an enteric pathogen of humans. Selected yeast-scFv clones were stabilized by lyophilization and used in detection assay formats in which the yeast-scFv served as solid support-bound monoclonal antibodies. Specific binding of antigen to the yeast-scFv was detected by staining with rabbit polyclonal antibodies. In flow cytometry-based assays, lyophilized yeast-scFv reagents retained full binding activity and specificity for their cognate antigens after 4 weeks of storage at room temperature in the absence of desiccants or stabilizers. Because flow cytometry is not available to all potential assay users, an immunofluorescence assay was also developed that detects antigen with similar sensitivity and specificity. Antigen-specific whole-cell yeast-scFv reagents can be selected from nonimmune libraries in 2–3 weeks, produced in vast quantities, and packaged in lyophilized form for extended shelf life. Lyophilized yeast-scFv show promise as low cost, renewable alternatives to monoclonal antibodies for diagnosis and research.
A digitized fluorescence imaging study of intracellular Ca2+, pH, and mitochondrial function in primary cultures of rabbit corneal epithelial cells exposed to sodium dodecyl sulfate.

Primary cultures of rabbit corneal epithelial cells have been developed as an in vitro system to predict irritancy potential and delayed cytotoxicity of surfactants in our laboratory. The objective of this study was to evaluate the effects of the surfactant sodium dodecyl sulfate (SDS), a common ingredient in consumer products, on intracellular Ca2+, pH, and mitochondrial function in this culture system. Ca2+ and pH were measured in single living corneal epithelial cells by ratio imaging of fura-2 and 2,′7′-bis(carboxyethyl)-5(6)-carboxyfluorescein fluorescence, respectively. Mitochondrial function was examined by probing mitochondrial membrane potential with the fluorescent dye rhodamine 123 and by measuring the ratio of ATP to ADP with an HPLC method. Cell viability was determined by fluorescence imaging of propidium iodide in single cells and LDH leakage assay in populations of cells. SDS (40 µg/ml) increased intracellular Ca2+ from 180±28nM to 453±86 nM within 2 min, and induced intracellular acidification (pHi dropped 0.3 units in 15 min). Treatment of the cultures with SDS also resulted in dissipation of the mitochondrial membrane potential and decrease of intracellular ATP/ADP. SDS-induced Ca2+ elevation and intracellular acidification preceded the loss of cell viability observed 20 min after exposure. However, SDS-induced cell injury does not appear to be triggered by extracellular Ca2+-influx, as absence of extracellular Ca2+ did not attenuate SDS-induced cytotoxicity while it completely blocked ionomycin-induced cytotoxicity. In summary, we observed a series of intracellular events that occurred temporally after exposure to the surfactant: elevation of intracellular Ca2+ and intracellular acidification, dissipation of mitochondrial membrane potential, decrease of ATP/ADP ratio, and subsequent cell injury.
Temperature monitor for freezers and cold stores

Abstract The production of high quality frozen foods requires careful management of the temperature of freezers and cold stores. This paper describes a monitoring system consisting of a datalogger housed in a temperature-controlled box. The system is a portable, inexpensive device, which allows small processors and laboratories to monitor and analyse performance data during various kinds of freezing and storage.
Evaluation of flow cell detector configurations combining simultaneous preconcentration and scintillation detection for monitoring of pertechnetate in aqueous media.

Flow cell detectors were developed for simultaneous concentration and scintillation detection of technetium-99 in water. Evaluated flow cell geometries consisted of a coil and a fountain flow cell design; the latter is based on radial solution flow through a resin bed interfaced with a photomultiplier tube through a polycarbonate window. The sorptive scintillating media investigated were (1) an extractive scintillator combining a porous polystyrene resin with the extractant Aliquat-336 and fluor 2-(1-naphthyl)-5-phenyloxazole, (2) a mixed bed of organic scintillator (BC-400) and Tc-selective resin (TEVA), and (3) a mixed bed of inorganic scintillator particles (CaF2−Eu) with either TEVA resin or strong base anion-exchange resin (Dowex 1 × 8−400(Cl)). Depending on flow cell geometry and medium, the detection efficiencies for 99Tc ranged from 7.26 (BC-400/TEVA in coil geometry) to 50.20% (CaF2(Eu)/Dowex 1 × 8−400(Cl) in fountain flow cell geometry). The configuration with the highest sensitivity, CaF2(Eu)/D...
Relationship between sediment resuspension and the statistical frequency distribution of bottom shear stress

Abstract Detailed observations of near-bottom turbidity and currents are used to examine the relationship between bottom shear stress and sediment resuspension. Turbidity is related to the statistical frequency distribution of bottom shear stress in a way that implies that a few high-stress events may be responsible for resuspension. Such short-period processes will usually be masked by conventional methods of data handling.
Performance estimates for a supersonic axisymmetric inlet system.

Results of recent tests of a large-scale axisymmetric mixed-compression inlet system designed for Mach number 2.65 indicate that the performance of the supersonic diffuser and required boundary-layer bleed system can be accurately estimated with relatively new analytic methods. Thus, many wind tunnel testing hours can be saved by avoiding much of the usual ?cut and try' wind tunnel development.
Teaching Young Learners about Sustainability.

“Why does Beatrice have to pay to go to school?” “Are Africa and Uganda the only poor places?” “What was her first house made from?” “Why did Beatrice's family get a goat, not a cow or money?” “How...
2‐D Electrophoresis gel data base analysis: Aspects of data structures and search strategies in GELLAB

Search strategies for finding spot differences among multiple two-dimensional (2-D) polyacrylamide electrophoresis gels are discussed in the context of the GELLAB spot data base management system. A 2-D gel experiment should have a well-defined biological experimental and preparation protocol reflecting the hypotheses of the problem. So too should the analysis of its corresponding 2-D gel computer spot data base have a protocol. This protocol is heavily influenced by the nature of the biological experiment as well as 2-D gel preparation considerations including the realities of artifactual and systematic noise. It is further influenced by constraints due to computational considerations. The search strategy is that part of the analysis protocol in which an experimenter iteratively defines tests to find significant spot differences. One goal of designing a well thought out search protocol is to reduce the number of search iterations required. Aspects of some requirements and constraints for useful search strategies are discussed.
HIV-1 GP120 V3 conformational and informational entropies

In an attempt to analyze structure, function and evolution of HIV-1 GP120 V3, interactions among the Hartree–Fock energy, the conformational entropy and the Shannon entropy were determined for the 1NJ0 set of antibody-bound V3 loop conformers. The Hartree–Fock energy of each conformer was determined at the MINI level with GAMESS. The conformational entropy was determined per conformer and per residue from the mass-weighted covariance matrices. The Shannon entropy per residue was determined from sequence-substitution frequencies. Correlations were determined by linear regression analysis. There was a negative correlation between the Hartree–Fock energy and the conformational entropy (R=−0.4840, p=0.0078, df =28) that enhanced the negative Helmholtz-free-energy change for the binding of the GP120 ligand to target CD4. The Shannon entropy of V3 was a function of the conformational entropy variance (R=0.7225, p=0.00157, df=15) and of the V3 Hartree–Fock energy. Biological implications of this work are that (1) conformational entropy interacts with V3 Hartree–Fock energy to enhance GP120 binding to CD4 cell receptors and that (2) the Hartree–Fock energy of V3 interacts with the evolutionary system to participate in the regulation of V3 diversity.
Pharmacokinetic profile of clonazepam in rhesus monkeys

Abstract The pharmacokinetic profile of clonazepam was studied in five chronically catheterized male rhesus monkeys using short-term intravenous infusion and oral administration in a Latin-square design. Clonazepam in a 40% polyethylene glycol 400 solution was infused at a constant rate over 25 hr into each monkey. Steady-state plasma levels in the ranges of 20, 40, 60, and 80 ng/ml were achieved with infusion rates of 15, 30, 45, and 60 μ g/hr/kg, respectively. An oral dose of 0.5 mg of clonazepam also was administered to each monkey by intranasal gastric intubation. Plasma levels were assayed by electron-capture GLC. The intravenous and oral kinetics of clonazepam could be described in terms of a one-compartment open model with first-order elimination. The mean (± SE ) parameters from short-term infusion studies were: total body clearance, 0.86 ± 0.03 liter/hr/kg; elimination half-life, 5.6 ± 0.6 hr; and volume of distribution, 6.8 ± 0.5 liters/kg. Intra- and interindividual variability in these parameters was prevalent, implying that dosing of monkeys during efficacy testing requires individual adjustments. Long-term (7–10-day) infusion studies revealed a small, but significant, decrease in clearance as well as diurnal oscillation in “steady-state” plasma levels.
Interactions between radioactively labeled colloids and natural particles: Evidence for colloidal pumping

It has been hypothesized that colloidal forms of trace metals can be reactive intermediaries in the scavenging processes leading to the removal of their particulate forms. A series of radiotracer experiments using natural colloidal organic matter from Galveston Bay, USA were carried out in order to test this hypothesis. Suspended particle uptake of originally colloidally bound trace metals occurred in a matter of hours to days in estuarine waters. After ten days, the majority (>50%) of the colloidal trace metals had been transferred into the particulate phase (≥0.45 μm), except for 65Zn. Two distinctively different temporal regions of removal of colloidal trace metals were identified: a faster reaction during the first four hours, followed by a slower reaction after approximately one day. In a separate river water-seawater mixing experiment, the solid/solution partitioning of the radiotracers was investigated in the absence of suspended matter. About 30% of most of the elements, except Ag and Fe (∼60%), were associated with a newly formed particulate phase after eight days. There were two major trends: (1) the particulate fraction of 59Fe and 110Ag increased while the colloidal fraction decreased, suggesting a colloidal pumping mechanism. (2) The particulate fraction of 54Mn, 133Ba, 65Zn, 109Cd, 113Sn, and 60CO increased while the LMW (≤ 1 kDa) fraction decreased, suggesting a direct uptake into the particulate fraction with less involvement of a transitory colloidal phase. The values of the particle-water (Kd) and colloid-water partitioning (Kc) coefficients for most trace metals were similar to those observed in Galveston Bay waters, suggesting complementary results to field studies. The results from these experiments suggested two different pathways for colloidal tracer uptake by particles: (1) colloidal pumping of a major component (e.g., biopolymer) of the colloidal pool and (2) coagulation of trace components (e.g., phytochelatins) with varying affinities for different trace metals. In support of these two different pathways, a number of correlations of particle-water (Kd) or colloid-water (Kc) partition coefficients with rate constants or reactive fractions were observed. In general, the higher the Kd values, the higher the reactive fractions, and the faster the trace colloid uptake by particles. Trace metals (e.g., Ag, Sn, Zn, Fe) which were found strongly organically complexed and associated mainly with colloidal matter in estuarine waters had a higher ion-colloid association rate constant. These experimental results suggest that interactions between surface-reactive fractions of the colloidal material and particles can play a crucial role in the solid-solution partitioning of many trace elements.
Phase field microelasticity modeling of surface instability of heteroepitaxial thin films

A development of the nonlinear surface instability of heteroepitaxial films during annealing process has been studied by using the phase field microelasticity model. The developed model considers the diffusional surface profile evolution of nonlinear grooved and coarsened regime, which is driven by the strain energy relaxation and is not constrained by any ad hoc assumptions concerning possible surface morphology. The method is based on the numerical solution of the exact elastic equilibrium equations. The simulation has shown that an initial small amplitude random roughening of a flat film develops to form a quasi-periodical array of islands under a certain balance between the strain and surface energies. This occurs through the competitive growth of amplitudes with different wavelengths. The surface morphology simultaneously grows and coarsens. The fully coarsened morphology exhibits a dominant wavelength that is significantly greater than the one that follows from the linear analysis of initial instability. The equilibrium morphology corresponding to a periodic array of islands is reached independent of the initial fluctuations of the surface profile.
A controlled trial of propafenone for treatment of frequent and repetitive ventricular premature complexes

Abstract The effectiveness of oral propafenone was evaluated for the treatment of ventricular premature complexes (VPCs) in 12 patients, using a singleblind, dose-ranging trial followed by a double-blind comparison with placebo, and then an open-label, long-term protocol. During dose ranging, 8 of 12 patients achieved ≥ 80 % suppression of total VPCs (mean 83%) (p
Inside Front Cover: Anisotropic Growth of PbSe Nanocrystals on Au–Fe3O4 Hybrid Nanoparticles (Adv. Mater. 14/2006)

PbSe nanorods and branched nanorods can be grown using binary Au/Fe3O4 nanoparticles as seeds, as reported by Swihart, Zeng, Prasad, and co-workers on p. 1889. PbSe nucleates on the Au portion of the seed particle and grows anisotropically as one or more straight or branched nanorods. The background images show PbSe nanorods (top), and ternary Fe3O4–Au–PbSe hybrid nanocrystals (bottom). High-resolution TEM images show Fe3O4(purple)–Au(gold)–PbSe (green) ternary nanocrystals. A ball-and-stick cartoon model illustrates the approximate size of these structures relative to the individual atoms.
Public school satisfaction with interdisciplinary services.

Representatives from local, regional, and state educational agencies throughout the country were surveyed to determine their satisfaction with services provided by University Affiliated Programs (UAps). Sixty-eight respondents from 26 stales and the District of Columbia returned questionnaires indicating their assessment of UAP services. Overall results showed highly positive ratings regarding access to UAP services, interdisciplinary evaluations, comprehensiveness, and relevancy of written reports and in-service training activities.
Environmental factors versus genetic determinants of childhood inhalant allergies

A classic question in many areas of medicine is nature versus nurture. When an individual develops an allergic disease, is the disease the result of heredity or the environment? Since the pioneering study of Cooke and Vander Veer, 1 published in 1916, the familial nature of atopic disease has not been seriously disputed; however, many studies have also demonstrated the importance of the environment on the genesis of allergic disease. 2-5 There are multiple reasons for considering the relative importance of genetic and environmental effects in the development of allergies. Parents ask about the risk of allergy in their children and about methods for reducing the risk of allergy. Patients inquire about why they have developed allergies and why allergies developed at a particular time. Assessment of the risk of allergy is also important in efforts to reduce occupational allergic disease and in designing studies to prevent other allergic diseases.
Analytical investigation of the atmospheric radiation limits in semigray atmospheres in radiative equilibrium

We model the wavelength-dependent absorption of atmospheric gases by assuming constant massabsorption coefficients in finite-width spectral bands. Such a semigray atmosphere is analyticallysolved by a discrete ordinate method. The general solution is analyzed for a water vapor saturatedatmosphere that also contains a carbon dioxide-like absorbing gas in the infrared. A multiple stableequilibrium with a relative upper limit in the outgoing long-wave radiation is found. Differing fromprevious radiative–convective models, we find that the amount of carbon dioxide strongly modifiesthe value of this relative upper limit. This result is also obtained in a gray (i.e., equal absorption ofradiation at all infrared wavelengths) water vapor saturated atmosphere. The destabilizing effect ofcarbon dioxide implies that massive carbon dioxide atmospheres are more likely to reach a runawaygreenhouse state than thin carbon dioxide ones. DOI: 10.1034/j.1600-0870.2003.00023.x
Purification and characterization of two ribonucleases from developing tomato fruit.

Abstract Two neutral ribonucleases have been purified from developing tomato fruit. Their activity is maximal 5 days after anthesis, declines during maturation, and then increases slightly in the mature green through breaker stages. The ribonucleases Tf1 and Tf2 have molecular weights of 59 and 29 K, respectively, based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and are glycoproteins. The reduced and denatured Tf1 is composed of two subunits, 30 and 29 K, of which only the 30-K subunit displays ribonuclease activity after renaturation. Reduced and denatured Tf2 is a single 29-K polypeptide that is renaturable to an active ribonuclease. Only the 30-K, active subunit of Tf1 is immunologically cross-reactive with Tf2. Both ribonucleases are cyclyzing endoribonucleases with a strong preference for cleavage at pyrimidine residues, thus generating oligonucleotide products ending with pyrimidine 2′,3′-cyclic phosphate. These tomato fruit ribonucleases share a number of properties in common with the S -glycoprotein ribonucleases that are involved in self-incompatibility reactions in some solanaceous plants.
How Drosophila larvae make glue: control of Sgs-3 gene expression

Abstract The glue genes of Drosophila are expressed under control of a steroid hormone in the salivary glands of third instar larvae. In this review, we describe the cis - and transacting elements that regulate expression of Sgs-3 , one of the glue genes. We also describe the normal association of Sgs-3 expression with a polytene chromosome puff, as well as mutations that uncouple puffing from gene expression.
Exploiting virus stealth technology for xenotransplantation: reduced human T cell responses to porcine cells expressing herpes simplex virus ICP47

Crew MD, Phanavanh B. Exploiting virus stealth technology for xenotransplantation: reduced human T cell responses to porcine cells expressing herpes simplex virus ICP47. Xenotransplantation 2003; 10: 50–59. © Blackwell Munksgaard, 2003 Direct recognition of porcine major histocompatibility complex (MHC) proteins by human T cells is well documented. Eliminating donor (porcine) MHC proteins may therefore be beneficial in pig-to-human xenotransplants. To this end, we have attempted to exploit viral stealth mechanisms to eliminate pig MHC class I cell-surface expression. PK(15) (pig kidney) cells stably transfected with the herpes simplex virus (HSV) ICP47 gene [PK(15)-ICP47 cells] exhibited a dramatic reduction of MHC class I cell-surface expression when compared with untransfected PK(15) cells. To test the effect of down-regulation of porcine MHC class I on human cellular immune responses, a human CD8+ enriched T cell line (anti-PK15 T cells) with reactivity towards PK(15) cells was derived by repeated stimulation of human T cells with PK(15) cells stably transfected with the costimulatory molecule B7.1 [PK(15)-B7.1 cells]. Anti-PK15 T cells efficiently lyzed PK(15) cells but not PK(15)-ICP47 (class I negative) cells. Consistent with effector function, anti-PK15 T cells showed a robust proliferative response to PK(15)-B7.1 cells but did not proliferate at all to PK(15)-B7.1 cells which also expressed HSV ICP47. These results suggest that virus stealth technology can be exploited for xenotransplantation.
Partial update NLMS algorithm for sparse system identification with switching between coefficient-based and input-based selection

Long impulse response system identification presents two challenges for standard normalized least mean square (NLMS) filtering method: heavy computational load and slow convergence. When the response is sparse, partial update algorithms can reduce the computational complexity, but most often at the expense of performance. This paper discusses the tap selection rule for partial update NLMS algorithm in the case of white Gaussian input. We consider output mean square error (MSE) minimization based on gradient analysis and propose an algorithm that switches tap selection criterion between the one based on filter coefficient magnitudes and the one based on input magnitudes. We show that for identifying sparse systems, the new algorithm can outperform standard NLMS significantly with a reduced computational load.
Substantial alterations of the cutaneous bacterial biota in psoriatic lesions.

For psoriasis, an idiopathic inflammatory disorder of the skin, the microbial biota has not been defined using cultivation-independent methods. We used broad-range 16S rDNA PCR for archaea and bacteria to examine the microbiota of normal and psoriatic skin. From 6 patients, 19 cutaneous samples (13 from diseased skin and 6 from normal skin) were obtained. Extracted DNA was subjected to the broad range PCR, and 1,925 cloned products were compared with 2,038 products previously reported from healthy persons. Using 98% sequence identity as a species boundary, 1,841 (95.6%) clones were similar to known bacterial 16S rDNA, representing 6 phyla, 86 genera, or 189 species-level operational taxonomic unit (SLOTU); 84 (4.4%) clones with <98% identity probably represented novel species. The most abundant and diverse phylum populating the psoriatic lesions was Firmicutes (46.2%), significantly (P<0.001) overrepresented, compared to the samples from uninvolved skin of the patients (39.0%) and healthy persons (24.4%). In contrast, Actinobacteria, the most prevalent and diverse phylum in normal skin samples from both healthy persons (47.6%) and the patients (47.8%), was significantly (P<0.01) underrepresented in the psoriatic lesion samples (37.3%). Representation of Propionibacterium species were lower in the psoriatic lesions (2.9±5.5%) than from normal persons (21.1±18.2%; P<0.001), whereas normal skin from the psoriatic patients showed intermediate levels (12.3±21.6%). We conclude that psoriasis is associated with substantial alteration in the composition and representation of the cutaneous bacterial biota.
PAK-in' Up cGMP for the Move

Although guanylyl cyclases have been implicated in cell migration, how they are activated to promote cell motility is unknown. In this issue, Guo et al. (2007) report direct communication between guanylyl cyclases and the Rac-p21-activated kinase (PAK) signaling pathway—which is essential for cell migration—to promote cell motility, through allosteric activation of guanylyl cyclases by autophosphorylated PAK.
Furanose Dynamics in the HhaI Methyltransferase Target DNA Studied by Solution and Solid-State NMR Relaxation

Both solid-state and solution NMR relaxation measurements are routinely used to quantify the internal dynamics of biomolecules, but in very few cases have these two techniques been applied to the same system, and even fewer attempts have been made so far to describe the results obtained through these two methods through a common theoretical framework. We have previously collected both solution 13C and solid-state 2H relaxation measurements for multiple nuclei within the furanose rings of several nucleotides of the DNA sequence recognized by HhaI methyltransferase. The data demonstrated that the furanose rings within the GCGC recognition sequence are very flexible, with the furanose rings of the cytidine, which is the methylation target, experiencing the most extensive motions. To interpret these experimental results quantitatively, we have developed a dynamic model of furanose rings based on the analysis of solid-state 2H line shapes. The motions are modeled by treating bond reorientations as Brownian exc...
Synthesis and Redox Behavior of Flavin Mononucleotide-Functionalized Single-Walled Carbon Nanotubes

In this contribution, we describe the synthesis and covalent attachment of an analogue of the flavin mononucleotide (FMN) cofactor onto carboxylic functionalities of single-walled carbon nanotubes (SWNTs). The synthesis of FMN derivative (12) was possible by coupling flavin H-phosphonate (9) with an aliphatic alcohol, using a previously unreported N-(3-dimethylaminopropyl)-N‘-ethylcarbodiimide hydrochloride coupling. We found that the flavin moiety of 12-SWNT shows a strong π−π interaction with the nanotube side-walls. This leads to a collapsed FMN configuration that quenches flavin photoluminescence (PL). The treatment of 12-SWNT with sodium dodecyl sulfate (SDS) overcomes this strong nanotube/isoalloxazine interaction and restores the FMN into extended conformation that recovers its luminescence. In addition, redox cycling as well as extended sonication were proven capable to temporally restore PL as well. Cyclic voltammetry of FMN onto SWNT forests indicated profound differences for the extended and co...
Relative size of the eye and orbit: An evolutionary and craniofacial constraint model for examining the etiology and disparate incidence of juvenile-onset myopia in humans

The principal aim of this research is to provide a new model for investigating myopia in humans, and contribute to an understanding of the degree to which modern variation and evolutionary change in orbital and overall craniofacial morphology may help explain the common eye form association with this condition. Recent research into long and short-term evolution of the human orbit reveals a number of changes in this feature, and particularly since the Upper Paleolithic. These include a reduction in orbital depth, a decrease in anterior projection of the upper and lower orbital margins, and most notably, a reduction in orbital volume since the Holocene in East Asia. Reduced orbital volume in this geographic region could exacerbate an existing trend in recent hominin evolution toward larger eyes in smaller orbits, and may help explain the unusually high frequency of myopia in East Asian populations. The objective of the current study is to test a null hypothesis of no relationship between a ratio of orbit to eye volume and spherical equivalent refractive error (SER) in a sample of Chinese adults, and examine how relative size of the eye within the orbit relates to SER between the sexes and across the sample population. Analysis of the orbit, eye, and SER reveals a strong relationship between relative size of the eye within the orbit and the severity of myopic refractive error. An orbit/eye ratio of 3 for females and 3.5 for males (or an eye that occupies approximately 34% and 29% of the orbit, respectively), designates a clear threshold at which myopia develops, and becomes progressively worse as the eye continues to occupy a greater proportion of the orbital cavity. These results indicate that relative size of the eye within the orbit is an important factor in the development of myopia, and suggests that individuals with large eyes in small orbits lack space for adequate development of ocular tissues, leading to compression and distortion of the lithesome globe within the confines of the orbital walls. The results of this study indicate that future research examining the etiology of juvenile-onset myopia, and particularly its correlation with ancestry, sex, age, and intelligence, should consider how the eye interacts with the matrix of structural and functional components of the skull during both ontogenetic and evolutionary morphogenesis.
Uniform strong estimation under α-mixing, with rates

Abstract Let s{;Xns};, n ⩾ 1, be a stationary α-mixing sequence of real-valued r.v.'s with distribution function (d.f.) F, probability density function (p.d.f.) f and mixing coefficient α(n). The d.f. F is estimated by the empirical d.f. Fn, based on the segment X1,…, Xn. By means of a mixingale argument, it is shown that Fn(x) converges almost surely to F(x) uniformly in x∈ R . An alternative approach, utilizing a Kiefer process approximation, establishes the law of the iterated logarithm for sups{;vb;Fn(x)−F(xvb;; x∈ R . The d.f. F is also estimated by a smooth estimate F n, which is shown to converge almost surely (a.s.) to F, and the rate of convergence of sups{;vb; F n(x) − F(x)vb;;|; x∈ R s}; is of the order of O((log log n/n) 1 2 ). The p.d.f. f is estimated by the usual kernel estimate fn, which is shown to converge a.s. to f uniformly in x∈ R , and the rate of this convergence is of the order of O((log log n/nh2n) 1 2 ), where hn is the bandwidth used in fn. As an application, the hazard rate r is estimated either by rn or r n, depending on whether Fn or F n is employed, and it is shown that rn(x) and r n(x) converge a.s. to r(x), uniformly over certain compact subsets of R , and the rate of convergence is again of the order of O((log log n/nh2n) 1 2 ). Finally, the rth order derivative of f, f(r), is estimated by f(r)n, and is shown that f(r)n(x) converges a.s. to f(r)(x) uniformly in x∈ R .The rate of this convergence is of the order of O((log log n/nh2(r+1)n) 1 2 ).
3-D Geometry-Based Statistical Modeling of Cross-Polarization Discrimination in Wireless Communication Channels

A new three-dimensional (3-D) geometry-based reference model for cross-polarization discrimination (XPD) in narrow-band fixed-to-fixed (F-to-F) or fixed-to-mobile (F-to-M) wireless channels is proposed. The proposed model is based on thesuperposition of polarization components on conservation-of-polarization planes (CoP-planes). This novel approach is used to derive the XPD at each distance without the aid of measurement data or its approximation. To the best of our knowledge this is the first purely theoretical geometry-based XPD reference model. Using our reference model, we obtain a relationship between XPD and channel modeling factors such as the distance between the transmitter and the receiver, the azimuth/elevation angles of arrival and departure (A/E-AoA and A/E-AoD), multipath delays, and the distribution of scatterers. Our analytical XPD model is in close agreement with previously reported results from other authors that are based on empirical measurement data, and it also overcomes the shortcoming of overapproximation/oversimplification of the measurement data.
Theoretic study of backmixing in simulated moving-bed adsorption process with multiple equilibrium stages between ports

Abstract A theoretic analysis of the simulated moving-bed process operated as a packed-bed with multiple equilibrium stages between external process ports is undertaken. A model has been proposed that correctly describes the time-averaged movement of individual process streams within the process. Axial mixing is incorporated into the model using the concept of mobile phase backmixing. The number of equilibrium stages between external process ports is shown to be an important parameter when considering design and operation of the simulated moving-bed process as a packed bed.
Cryptic Bracts Exposed: Insights into the Regulation of Leaf Expansion

Arabidopsis is unusual in producing flowers that are not subtended by specialized leaves, called floral bracts. Writing in Development, Dinneny et al. and Ohno et al. show that gain-of-function mutations of the JAGGED transcription factor produce bracts, and provide evidence that this gene plays a key role in a developmental program that regulates the size and shape of all leaves and leaf-homologs.
Examining the flexibility bind in American tenure and promotion processes: an institutional ethnographic approach

This paper analyses the role that forms of documentation play in faculty members' experiences of tenure and promotion. Taking an institutional ethnography approach, it examines inconsistencies and ambiguities in documents and connects them to the experiences of science, technology, engineering and mathematics (STEM) faculty at one institution in the USA. The authors argue that the university documentation surrounding tenure and promotion does not capture the actual practices and experiences of faculty members as they prepare for their tenure or promotion and that the documentation creates a ‘flexibility bind’ of tenure and promotion. Faculty members' strategies for navigating this bind are also examined. The implications of these findings for diversity among STEM faculty are also explored.