cssi/SciSciGPT-SciSciNet huggingface dataset:
Regulation of murine B cell Thy-1 expression by IL-4, IFN-γ, and CD4+ T cell subsets

Abstract Interleukin 4 (IL-4) induces the expression of membrane Thy-1 on the vast majority of lipopolysaccharide (LPS)-stimulated normal murine B cells in vitro. This induction is inhibited by interferon-gamma (IFN-γ). IL-4 and IFN-γ are required late in culture to effect maximal induction and inhibition of Thy-1 expression by LPS- or LPS + IL-4-stimulated B cells, respectively. IFN-γ suppresses IL-4-induced Thy-1 expression by inhibiting the induction of steady-state levels of Thy-1-specific mRNA. Three distinct CD4+ Th2 clones, through their release of IL-4, induce B cells to express high levels of Thy-1, by 24 hr, in striking contrast to the 3 days required to induce Thy-1 expression after stimulation with LPS and IL-4. This induction is abrogated by the addition of IFN-γ. B cells stimulated with three distinct Th1 clones (IFN-γ- and IL-2-producing) exhibit a modest, non-IL-4-dependent, expression of Thy-1. In contrast to intrinsic expression of Thy-1 by Th2-stimulated B cells, Thy-1 expressed by Th1-stimulated B cells is acquired, having the allotype specificity of the stimulating T cell.
Expectations and Users' Satisfaction with a University Dining Facility:

This study examined the effect of expectations on 116 students' satisfaction with a university facility. Lowered expectations and subjects' awareness of remodeling plans for the interior of a facil...
Review of "A survey of computer hardware description languages in U.S.A. by Stephen Y. H. Su", to be published in COMPUTER, December 1974.

One important goal in digital engineering is to find a language which is descriptive, efficient for simulation and automatic hardware implementation purposes.In this paper, the different levels of CHDL (computer hardware description languages) are introduced. Existing CHDL are surveyed and the features of these languages are pointed out. A table lists the names of CHDL, the authors, and the references. It also points out what language each CHDL is adapted from and reports the status of the implementation of these languages. Suggestions for overcoming the difficulties of using CHDL for computer-aided system/logic design are given.
Lobster and Groundfish Management in the Gulf of Maine: A Rational Choice Perspective

Many of the world’s most important fisheries are in a state of crisis. The Maine lobster industry is one of the very few exceptions, with catches at an all time high. Much of the success of this fishery stems from effective conservation legislation, passed largely through the long-term lobbying activities of powerful factions within the industry itself. In stark contrast is the Maine groundfishery, where stocks and catches have never been so low. This industry has had to deal with a top-down management system that has given it little incentive to conserve and has made it virtually impossible to get rules the industry considers effective. They have responded by using a roving bandit strategy. From the perspective of rational choice theory, the basic difference is that the lobster industry has been able to organize politically to get legislation to solve its communal action dilemma, while the groundfishing industry, like most fishing industries, has not. This paper explores the biological, technical, econom...
Ferrocenyl-amidinium compound as building block for aqueous proton-coupled electron transfer studies

Abstract A water-soluble amidinium-appended ferrocene moiety is characterized in which the amidinium functionality is fused directly to the ferrocene ring (Fcam1). This species is designed to form a building block for aqueous proton-coupled electron transfer in which proton transfer occurs to the bulk and electron transfer occurs to a chemical oxidant. pH-Dependent absorption spectroscopy and electrochemistry show that the electrochemical potential is directly linked to the protonation state of the amidinium. A thermodynamic square scheme is constructed for Fcam1. The square scheme serves as motivation and provides direction for incorporating this species into a covalently-bound system for the study of proton-coupled electron transfer.
The apparent lack of repair of O6-methylguanine in nuclear DNA of Chlamydomonas reinhardtii

Abstract Pretreatment fo Chlamydomonas reinhardtii with adaptive doses of N-methyl-N′-nitrosoguanidine did not increase the resistance of the cells to the lethal or mutagenic effects of a subsequent challenge dose of the alkylating agent. Assay of cell-free extracts prepared with various protocols failed to reveal the presence of a methyltransferase specific for O6-methylguanine. The lower limit of detection was calculated to about 150 molecules of transferase per cell. The amount of O6-methylguanine formed in Chlamydomonas DNA after treatment of the cells in vivo was measured using a sensitive competition assay. No significant O6-methylguanine was removed after as much as 30 h of incubation after treatment with the alkylating agent, leading to the conclusion that Chlamydomonas lacks a repair system for O6-methylguanine.
The Effect of Systolic Hypertension on Rhesus Monkey Eyes After Ocular Sympathectomy

Systolic hypertension was induced in rhesus monkeys by obstructing the thoracic aorta and by ocular sympathectomy obtained with the retrobulbar injection of 6-hydroxydopamine. During the late phase of fluorescein angiography, fluorescein leaked from the choroidal circulation into the retina. The retinal vessels did not leak fluorescein. The effect was not permanent since fluorescein did not leak into the retina after the blood pressure returned to normal.
Effects of die‐pad resonance on ultrasonic bond quality of wire bonds

Purpose – Wire bonding is an important method of interconnection in microelectronics. Ultrasonic energy is known to soften metallic materials and hence when used in the wire bond process it is effective to decrease the flow stress similar to thermal energy. The paper aims to address this issue.Design/methodology/approach – Detailed resonance studies show that some designs have closeby resonance compared to the bonding frequency which causes enhanced vibration resulting in such over squashed bonds. Hence, precautions in the design stage are necessary to understand the closeby resonance frequencies and corresponding mode shapes of the leadframe that are in‐plane in nature along the transducer axis that can be excited by the capillary's motion. This can be determined a priori using numerical methods such as finite element method. In this paper, one such case study has been dealt in detail to explain the overall methodology.Findings – To minimize the effects of resonance, damping should be increased by bondin...
Mms2–Ubc13 covalently bound to ubiquitin reveals the structural basis of linkage-specific polyubiquitin chain formation

Lys63-linked polyubiquitin chains participate in nonproteolytic signaling pathways, including regulation of DNA damage tolerance and NF-κB activation. E2 enzymes bound to ubiquitin E2 variants (UEV) are vital in these pathways, synthesizing Lys63-linked polyubiquitin chains, but how these complexes achieve specificity for a particular lysine linkage has been unclear. We have determined the crystal structure of an Mms2–Ubc13-ubiquitin (UEV–E2-Ub) covalent intermediate with donor ubiquitin linked to the active site residue of Ubc13. In the structure, the unexpected binding of a donor ubiquitin of one Mms2–Ubc13-Ub complex to the acceptor-binding site of Mms2–Ubc13 in an adjacent complex allows us to visualize at atomic resolution the molecular determinants of acceptor-ubiquitin binding. The structure reveals the key role of Mms2 in allowing selective insertion of Lys63 into the Ubc13 active site and suggests a molecular model for polyubiquitin chain elongation.
The structure of crystallized suspensions of polystyrene spheres

Abstract We have determined the crystal structure of an ordered aqueous suspension of polystyrene spheres using Bragg scattering of laser light. At low concentrations a body-centered cubic structure is found. At higher concentrations this is found together with face-centered cubic. We believe that the ordering is due to Coulomb repulsion as in the Wigner crystal.
Recent advances in liquid chromatography-mass spectrometry and capillary zone electrophoresis-mass spectrometry for protein analysis

The utility of the combination of separations techniques, such as liquid chromatography and capillary zone electrophoresis, with mass spectrometry in applications involving protein analysis is discussed. The use of continuous-flow fast atom bombardment and electrospray ionization mass spectrometry is compared for the analysis of tryptic digests. For liquid chromatography, both microbore and slurry-packed capillary bore columns were used to separate peptides from proteolytic digests.
Soot formation in methane/air nonpremixed flames doped with small quantities of C3 hydrocarbons

Gas temperature, Cl to C12 stable hydrocarbon concentrations, and soot volume fractions were measured in an axisymmetric methane/air coflowing nonpremixed flame whose fuel was doped with one mole per cent allene, propene, and propane. The additives did not significantly alter the temperature field, methane mole fractions, or chain-carrying radical concentrations. However, soot volume fractions were increased, in the order allene > propene > propane. The hydrocarbon species measurements indicated that soot formation increases because the additives undergo reaction sequences that raise the concentrations of the benzene and phenyl radical precursors C3H3, C4H3, and C4H5, and consequently enhance the benzene/phenyl formation rate. Therefore, creation of these precursors and of the first aromatic ring are crucial rate-limiting soot formation steps in methane flames.
Syntheses of nido-9,11-X2-7,8-C2B9H10 − anions (X=Cl, Br or I) and the synthesis and structural characterization of N(C2H5)4[commo-3,3′-Co(4,7-Br2-3,1,2-CoC2B9H9)2]

Treatment of nido -7,8-C 2 B 9 H 12 − with N -halosuccinimide (halo=chloro, bromo or iodo) formed the corresponding nido -9,11-(halo) 2 -7,8-C 2 B 9 H 10 − ion in good yield. The nido -9,11-Br 2 -7,8-C 2 B 9 H 10 − ion was deprotonated with n -butyllithium and then reacted with cobalt(II) chloride to form the commo -3,3′-Co(4,7-Br 2 -3,1,2-CoC 2 B 9 H 9 ) 2 − ion. A single-crystal X-ray structure determination of this cobalt complex is reported.
Time dependence of axial pile response

This communication describes an approximate method for generalizing homogeneous, linearly elastic, subgrade type solutions of axial pile response to account for soil creep behaviour. The method is very simple to apply and can be used in conjunction with either analytical or numerical elastic solutions. Exact solutions for limiting cases and finite difference solutions in both space and time are presented to confirm that errors introduced by the approximations are small. Because of the theoretical basis of this approach it is anticipated that method can be used with other pile problems, lateral and axial, for both subgrade adn continuum idealizations. Methods for generalizing the results to more complex conditions such as non-homogeneity or time varying loads are given.
Elastothermodynamic analysis of a Griffith crack

Abstract When a homogeneous material is subjected to a nonuniform stress field, different regions undergo different temperature fluctuations due to the well-known thermoelastic effect. As a result irreversible heat conduction occurs, and entropy is produced which is manifested as a conversion of mechanical energy into heat. Moreover, the changes in temperature produce a thermal strain that is out of phase with the stress, thus converting mechanical energy into heat, i.e. work is lost. In this paper we present an approximate analysis of the entropy produced and work lost in the neighborhood of a Griffith crack subjected to a time-harmonic loading in modes I, II, and III. In all three modes the temperature at the crack tip remains bounded. In mode I the entropy produced (per unit volume per cycle) is finite at the crack tip, whereas the work lost (per unit volume per cycle) goes to infinity as1√r. Conversely, in mode II the entropy produced goes to infinity as1/r as the crack tip is approached, whereas the work lost is finite. In mode III the thermoelastic effect disappears altogether and, therefore, both the entropy produced and the work lost are zero throughout the plate.
Multiresponsive Block Copolymer-Modified “Hairy” Gold Nanoparticles for Remote Control of Interfaces

Hybrid gold nanoparticles modified with poly(N-isopropylacrylamide)-block-poly(2-succinyloxyethyl methacrylate) (PNIPAM-b-PSEMA) brushes are synthesized using surface-initiated atom transfer radical polymerization (SI-ATRP). The “hairy” particles demonstrate reversible pH- and temperature-controlled changes in size and aggregation state in solution. When adsorbed within a sub-monolayer at a solid surface, they support reversible changes in surface wettability in response to changes in solution pH, temperature, or illumination by laser light.
Energy-Efficient and Reliable Medium Access in Sensor Networks

Energy efficiency and reliable data delivery are the two most important parameters for designing wireless sensor network protocols. Wireless communication is inherently unpredictable and error-prone. Hence, reliability is required to ensure that a packet reaches its desired destination; otherwise the energy expended in forwarding the packet is wasted On the other hand, energy-saving mechanisms are required for battery-constrained sensor networks. In this paper, we have designed an on-demand energy-efficient and reliable medium access control (E2RM: AC) protocol that enables reliable data delivery and energy conservation without affecting packet latency. We have demonstrated the superior performance of E2RMAC over existing energy-efficient and reliability-enforcing approaches in terms of reliability, latency, scalability and energy-efficiency.
Complex Formation Influence on Reaction Rate IV: Studies on the Kinetic Behavior of 3-Carbomethoxy-1-Methylpyridinium Cation

The kinetics of reaction of the ester, 3-carbomethoxy-1-methylpyridinium cation (NME), were investigated in the pH region 8.0–9.8, in the absence and presence of the electron donor, 8-chlorotheophyllinate anion (CT). Hydrolysis of the ester was shown to be first order with respect to hydroxide ion in this region. The rate of hydrolysis was significantly decreased in the presence of CT. Spectral studies demonstrated the formation of a complex between the ester and CT. The rate of reaction of the complexed ester was about one-fifteenth that of the free ester. Both glycine and TRIS buffers were shown to contribute to the rate of reaction. The contribution due to glycine appeared to be the result of glycinate anion functioning as a general base catalyst. The mechanism of the TRIS reaction appeared to be different from that of glycine. The data suggested that neutral TRIS and the ester reacted by two different pathways to form an unstable ester or a stable amide.
Four photon interference experiment for the testing of the Greenberger-Horne-Zeilinger theorem

Abstract The theory of a four photon interference experiment is investigated for the testing of the Greenberger-Horne-Zeilinger (GHZ) theorem. The strong correlation in the GHZ theorem is due to the multi-particle Einstein-Podolsky-Rosen type entangled quantum state. We present the theory to construct the four photon EPR state for space-time variables. The four photon nonlocal quantum interference effect itself is also of great interest.
Public relations in the eye of the storm: Lessons from professionals in the wake of Hurricanes Katrina and Rita

Abstract In the wake of Hurricanes Katrina and Rita, public relations practitioners balanced accommodating their publics and advocating for their organization. Interviews conducted with public relations practitioners in Baton Rouge and New Orleans, Louisiana, revealed that they primarily focused on accommodating their publics. The experiences of public relations practitioners during Hurricanes Katrina and Rita trigger several suggestions for practitioners preparing for potential crises.
Abstract 1759: Novel naphthalimide analogs elicit their anti-tumor activity through a dual inhibition of topoisomerase II and Akt signaling pathway

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Naphthalimide derivatives such as mitonafide, a topoisomerase II inhibitor, have shown antitumor activity both in preclinical studies and in phase I and phase II clinical trials. However, it suffers from severe toxicity issues, especially central nervous system (CNS) toxicity. We have recently reported promising naphthalimide analogs designed by incorporating functional groups such as a isothiocyanate (ITC) group which is present in chemicals found in cruciferous vegetables, in place of N, N-dimethyl group in mitonafide. Some of these agents effectively induced apoptosis in melanoma cells and inhibited cell proliferation, and inhibited melanoma tumor growth by ∼60% without any apparent systemic toxicity issues. The ITC group was incorporated in the structure in an attempt to lower the toxicity associated with mitonafide and also because this functionality has been shown to block PI3K/Akt pathway which is activated in majority of cancer types; Akt3 is activated in 70% of sporadic melanomas. The idea was to generate a compound capable of inhibiting not only topoisomerase II similar to mitonafide but also PI3K kinase. In order to evaluate the underlying mechanism of action, we first evaluated topoisomerase-II inhibitory activity of agents relative to mitonafide to check if the new agents retained this property. Relaxation activity of DNA topoisomerase II was determined by measuring the conversion of supercoiled pBR322 plasmid DNA to its relaxed form. Our results indicate that the ITC analogs, NNITC-2 and NITC-6, exhibited significant inhibition for DNA-topoisomerase II similar to mitonafide. Interestingly, corresponding isoselenocyanate (ISC) analog NISC-6 was less effective compared to NITC-6 as a topoisomerase II inhibitor; NNISC-2 on the other hand was equally good as NNITC-2. Furthermore, to test our hypothesis that the addition of ITC group into the structure would make it capable of inhibiting PI3K/Akt pathway, we examined the ability of naphthalimide derivatives to inhibit the total cellular content of human Akt pathway proteins, by Western blot analysis using polyclonal antibodies, in human melanoma cancer cells (UACC903). UACC903 cells treated with ITC derivatives at 0.5, 1 and 5 μM, showed a rapid decrease in Akt pathway proteins level in a dose-dependent manner. In comparison, ISC analogs were less effective. Detailed results of these investigations will be presented. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1759. doi:1538-7445.AM2012-1759
Question answering and database querying: Bridging the gap with generalized quantification

Abstract Even though Questions Answering and Database Querying have very different goals and frameworks, collaboration between the two fields could be mutually beneficial. However, the different assumptions in each field makes such collaboration difficult. In this paper, we introduce a query language with generalized quantifiers (QLGQ) and show how it could be used to help bridge the gap between the two fields.
DNA ploidy and the percentage of cells in S‐phase as prognostic factors for women with lymph node negative breast cancer

Background. Previous cell kinetic studies have shown that the percentage of cells in S-phase (%S) of the tumor may be an important prognostic factor for relapsefree survival (RFS) and overall survival (OS) in patients with resected lymph node negative breast cancer. Methods. This study examined DNA ploidy and %S from the paraffin embedded primary tumors of 265 patients who had surgery between 1975 and 1981, had lymph node negative cancer, and had no adjuvant therapy. The %S and %G2M values were calculated using a debris and aggregate subtraction model. Results. The results of the DNA ploidy analysis revealed 130 (49%) DNA diploid tumors and 135 (51%) DNA nondiploid tumors. Ploidy was not significant for either RFS (P = 0.20) or OS (P = 0.13). The total %S (using a cutoff of 8%) was a statistically significant prognostic factor for RFS (P = 0.003) and borderline for OS (P = 0.08). The proliferation fraction (%S + %G2M), using a cutoff of 12.5, was a statistically significant prognostic factor for RFS (P = 0.01) and for OS (P = 0.01). In a Cox multivariate analysis for RFS, the total %S remained significant (P = 0.05) along with tumor size. In the analysis of OS, the proliferation fraction remained significant (P = 0.03) along with tumor size and age. DNA ploidy was not significant in any multivariate analysis. Conclusions. This study suggests that tumor size and cell proliferation parameters are independent prognostic factors for patients with resected lymph node negative breast cancer. However, the clinical usefulness of the cell kinetic parameters appears limited.
The early steps in the unfolding of azurin.

High-temperature molecular dynamics simulations were used to gain insight into the early steps in the unfolding pathway of azurin, a blue copper protein with a β-barrel structure formed by two sheets arranged in a Greek key folding topology. The results reveal that unfolding of the β-barrel in azurin is associated with dislocation of its unique α-helix with respect to the protein scaffold. Exposure of the hydrophobic core to solvent precedes complete disruption of secondary and tertiary structure, and modifications in the region around the active site are directly connected with this event. Denaturation of the protein initiates from the sheet coordinating the copper ion, and the other sheet maintains its topology. Results derived from the simulation were compared with experimental data obtained with different techniques, showing excellent agreement and providing a framework to understand the process of disruption and formation of the β-barrel in azurin.
Evaluation of Road Maintenance Automation

Automated road maintenance can produce direct and indirect cost savings; improvements in safety, quality, working environment, and productivity; and reduction of vehicle emissions and energy consumption due to expedited maintenance operations. However evaluating automation needs and systems at various stages of development is difficult. The objectives of the research described here were to: (1) develop a systematic methodology to evaluate the costs and benefits of automated road maintenance; (2) to identify the maintenance activities that are conceptually feasible for automation; and (3) to evaluate the technical feasibility of specific automated systems. The first objective was achieved by the development of a comprehensive Automated Road Maintenance Evaluation (ARME) methodology. The ARME methodology provides procedures through which maintenance activities or systems designed to automate those activities can be evaluated from economic and qualitative perspectives. The second objective was achieved by using the ARME methodology’s needs assessment procedure to evaluate the conceptual feasibility of automating the major maintenance activities of the Texas Department of Transportation (TxDOT). Of the 25 maintenance activities evaluated, those found to be conceptually feasible for automation include base removal and replacement, crack and joint sealing, leveling or overlays, pothole repairs, strip and spot seal, seal coat, ditch maintenance, traffic assistance, and paint and bead striping. The third objective was achieved by using the ARME methodology’s technology evaluation procedure to evaluate the technical feasibility of implementing an Automated Crack Sealer (ACS) system in Texas. An ACS system is considered feasible, and field implementation is now in progress. Transportation departments can apply the ARME methodology in their own environments to support decisions concerning automation.
Effect of non-equilibrium plasma on two-stage ignition of n-heptane

Abstract The effect of pulsed nanosecond dielectric barrier plasma discharges on the ignition characteristics of n-heptane and air mixtures is investigated through self-consistent simulations in a plane-to-plane geometry at reduced pressures (20.3 kPa). The present work represents one of the first attempts in understanding the kinetic and thermal effects of nanosecond pulsed discharges on the two-stage ignition process of n-heptane. A plasma-fluid formulation is developed with ions and neutral species at gas temperature, and electrons in non-equilibrium. The work makes use of an optimized chemical kinetics mechanism consisting of 166 species and 611 reactions, obtained by combining a reduced n-heptane kinetic model, a non-equilibrium plasma chemistry scheme, and a NO x kinetic model. The catalytic effect from plasma-generated radicals on the first stage of the n-heptane ignition process has been identified. Production of radicals such as O, H and OH from the plasma initiates and accelerates the H abstraction of fuel molecules, and dramatically reduces the induction time of the exothermic cycle ( RH → R → RO 2 → OROOH ) by a factor of 10. Furthermore, the plasma action on low temperature chemistry is found to be nearly independent of the equivalence ratio and more pronounced at lower temperatures (550–650 K). A staggered application of nanosecond voltage pulses (2–4 pulses at the beginning and 20–30 pulses after the first stage heat release) is shown to be optimal, resulting in a reduction of the ignition delay by approximately a factor of 2. NO production from the plasma via electron impact and quenching processes at low temperatures plays an important role in promoting chain-branching reactions and contributes to shortening the ignition delay by approximately 10%.
Notes on the geology of Iwo Jima

Iwo Jima is near the south end of a chain of volcanic islands extending south from Tokyo Bay. The principal rock on the island is a soft tuff in roughly horizontal layers. Massive trachyandesite, in large part extrusive, is exposed at the north and south ends of the island. Both the lava and plutonic inclusions within the lava have a much higher alkali content than is common in the rocks of Japan proper. Suribachi-yama, the small volcano at the south end of Iwo, is made up of three roughly horizontal layers, two of tuff and one of lava, topped with a thin veneer of fairly recent pyroclastic debris. Fragments of modern coral at high elevations indicate that all or most of the Island was submerged in the fairly recent geologic past. As the island emerged, terraces were cut in the tuff at the north end and a deposit of loose coarse sand and gravel was formed in the low central part. Numerous solfataras are the only present indication of volcanic activity. The last eruption of Suribachi probably took place several centuries ago, and there is no suggestion in the present activity that further eruptions are imminent.
Johann Christian Rosenmüller (1771-1820): A Historical Perspective on the Man behind the Fossa.

Introduction The fossa of Rosenmuller, also known as the lateral pharyngeal recess, is a well-established site of origin of nasopharyngeal carcinoma. It is located in the lateral pharyngeal wall behind the cartilaginous portion of the Eustachian tube, the torus tubarius, and is named after Johann Christian Rosenmuller (JCR). Objective We present a history on the life and extensive works of Johann Christian Rosenmuller, a German physician and anatomist. Results Johann Christian Rosenmuller was a dedicated anatomist. In addition to identifying the fossa of Rosenmuller, his influence extends to various other anatomic subjects, including the Rosenmuller gland, the palpebral portion of the lacrimal gland, and the organ of Rosenmuller (i.e., the caudal remnant of the mesonephric duct). He was also an avid speleologist, studying the composition of caves and their life forms. For his contributions to this field, he had a cave in Germany and an extinct species named after him—Rosenmullerhohle and Ursus spelaeus Rosenmuller, respectively. Conclusion The fossa of Rosenmuller plays an important role in the growth and surgical treatment of nasopharyngeal carcinoma. We present a brief glimpse into the life of Johann Christian Rosenmuller, for whom it was named.
Scientific realism: A challenge to physicists

If a physicist claims to be a realist, he or she must face at least the three problems outlined here: the careful specification of the validity limits of every theory and model used, the coherence relationships that must hold between two theories of the same physical system but on different cognitive levels, and the ambiguity in the ontology of two different formulations of empirically equivalent theories.
The three-dimensional structure of HLA-B27 at 2.1 Å resolution suggests a general mechanism for tight peptide binding to MHC

Cell surface complexes of class I MHC molecules and bound peptide antigens serve as specific recognition elements controlling the cytotoxic immune response. The 2.1 A structure of the human class I MHC molecule HLA-B27 provides a detailed composite image of a co-crystallized collection of HLA-B27-bound peptides, indicating that they share a common main-chain structure and length. It also permits direct visualization of the conservation of arginine as an "anchor" side chain at the second peptide position, which is bound in a potentially HLA-B27-specific pocket and may therefore have a role in the association of HLA-B27 with several diseases. Tight peptide binding to class I MHC molecules appears to result from the extensive contacts found at the ends of the cleft between peptide main-chain atoms and conserved MHC side chains, which also involve the peptide in stabilizing the three-dimensional fold of HLA-B27. The concentration of binding interactions at the peptide termini permits extensive sequence (and probably some length) variability in the center of the peptide, where it is exposed for T cell recognition.
Choosing a random spanning subtree: a case study

Broder(4) has suggested a stochastic algorithm for generating a random spanning subtree of a graph. This paper studies this algorithm for a special class of graphs. A complete spectral decomposition of the associated Markov chain is given. The analysis available from this is compared to stopping-time techniques and purely geometric bounds on the second eigenvalue.
Rectilinear shear flow of fluid with interacting deformable substructure

Die Grundgleichungen fur eine lineare Theorie der Flussigkeiten mit starker Konzentration suspendierter Partikel werden auf das Problem der geradlinigen Stromung mit Flussigkeitsreibung zwischen zwei Platten angewandt. Es werden die Geschwindigkeit, die Partikeldeformation und die Spannungen bestimmt.
The central drift chamber for the MARK III detector at SPEAR

Abstract A large cylindrical drift chamber has been constructed for the MARK III detector at SPEAR. The inner layer has a high density of sense wires for the measurement of kinks, vees, and d E d x . The outer layers have a cell design with three sense wires, giving uniform drift behavior and left/right ambiguity resolution within a cell. The chamber has both current division and stereo layers for longitudinal position measurement.
D-tagatose, a novel hexose: acute effects on carbohydrate tolerance in subjects with and without type 2 diabetes.

Summary Aim: D-Tagatose (D-tag), a hexose bulk sweetener, does not affect plasma glucose levels when orally administered to rodents. Additionally, D-tag attenuates the rise in plasma glucose after mice are administered oral sucrose. The current study was undertaken to investigate the acute glycaemic effects of oral D-tag alone or in combination with oral glucose in human subjects with and without type 2 diabetes mellitus. Glycaemic responses to D-tag also were investigated in subjects after oral sucrose to examine whether the glucose-lowering effects of D-tag in rodents may result from a direct inhibition of intestinal disaccharidases. Methods: Eight normal and eight subjects with diabetes mellitus were administered 75 g of glucose, 75 g of D-tag, or 75 g of D-tag 30 min prior to a 75 g oral glucose tolerance test (OGTT). Five patients with diabetes mellitus were challenged with a 75 g oral sucrose tolerance test (OSTT) with and without oral pre-treatment with 75 g of D-tag. Patients with diabetes mellitus also received separate 0, 10, 15, 20 and 30 g of D-tag 30 min prior to a 75 g OGTT. Results: Oral loading with D-tag alone led to no changes in glucose or insulin levels in either normal patients or those with diabetes mellitus. Pre-OGTT treatment with 75 g D-tag, however, attenuated the rise in glucose levels in patients with diabetes mellitus (p < 0.02 at 60 and 180 min, and p < 0.01 at 120 min). The glucose area under the curve (AUC) was reduced significantly also by pre-treatment with D-tag in a dose-dependent manner in patients with diabetes mellitus (p < 0.05 for 10 g D-tag, p < 0.001 for 20 g D-tag, and p = 0.0001 for 30 g D-tag). In patients with diabetes mellitus 75 g D-tag similarly attenuated the rise in glucose following an OSTT (p < 0.01 at 30 min, and p < 0.02 at 60 min). Pre-treatment with 75 g D-tag also tended to blunt the rise in insulin following an OGTT in normal patients (p = 0.07 for insulin AUC) but not patients with diabetes mellitus (p = 0.66). Following 75 g of oral D-tag in four normal patients, plasma D-tag levels rose to a mean peak level of 3.6 mg/dl at 90 min.The administration of 75 g d-tag led to diarrhoea, nausea and/or flatulence in 100% of subjects. When D-tag was administered at lower doses ranging from 10 g to 30 g, only three of 10 patients with diabetes mellitus had gastrointestinal symptoms which were much more mild than those evoked by 75 g D-tag. Conclusions: These results show that oral D-tag significantly blunts the rise in plasma glucose seen after oral glucose in patients with diabetes mellitus in a dose-dependent manner without significantly affecting insulin levels. The minimal elevation of plasma D-tag levels in normal patients and the adverse gastrointestinal effects seen following larger doses of D-tag support poor absorption of this hexose and suggest that D-tag may act by attenuating glucose absorption in the intestine. D-tag may be a useful therapeutic adjunct in the management of type 2 diabetes mellitus.
Atomic resolution X-ray standing wave microstructural characterization of NLO-active self-assembled chromophoric superlattices

This contribution reports the first X-ray standing wave structural characterization of self-assembled NLO-active chromophoric multilayers (SAMs). These siloxane-based self-assembled stilbazolium multilayers are intrinsically acentric and exhibit very large second-order nonlinear optical responses. The locations of bromide ions within the SAMs were precisely determined using X-ray standing waves generated by total external reflection form mirror surfaces as well as by Bragg diffraction from layered synthetic microstructures. The large coherent fraction (i.e., small Gaussian distribution width) of the Br{sup -} ions provides direct evidence for the high structural regularity of these self-assembled multilayers along the surface normal direction. These results are supported by atomic force microscopic (AFM) and X-ray photoelectron spectroscopic (XPS) studies which probe the structural regularity and chemical composition of SAMs, respectively. The anion surface coverage has also been measured in this study (2.5(5) x 10{sup 14} Br{sup -}/cm{sup 2}) and is in excellent agreement with the cation surface coverage measured by second harmonic generation (2(1) x 10{sup 14} molecules/cm{sup 2}). These results clearly demonstrate the utility of X-ray standing wave analyses as a quantitative microstructural probe for self-assembled mono- and multilayers, especially for SAMs with incommensurate structures. 17 refs., 5 figs., 1 tab.
SU‐FF‐T‐490: The Effect of Daily Cone Beam CT Imaging Dose On the Secondary Cancer Risk for Patients Receiving Prostate IMRT Treatments

Purpose: The impact of daily kilovoltage cone beam CT(CBCT)imagingdose on the radiation induced cancer risk (RICR) was evaluated for patients receiving prostate IMRTtreatments.Materials and Methods: Increased secondary cancer risk was modeled by employing effective dose concept described in ICRP report 103 as basis. A prostate IMRT plan was generated in the treatment planning software to calculate dose to organs within the treatment volume. Scattered and leakage dose to organs outside the treatment volume, and CBCTimagingdose were obtained from data in published literature. Both linear and nonlinear risk‐dose response models were considered to establish a relationship between RICR and absorbed dose in the therapeuticdose range. ICRP 103 tissue weighting factors were assumed to stay the constant as a function of absorbed dose.Results: We calculated the relative increase in RICR for various RICR‐dose response models. If the secondary cancer risk was assumed to be proportional to absorbed dose, the increase in RICR due to daily CBCTimaging was in the order of 5%. If the secondary cancer risk was assumed to fall off exponentially at therapeuticdoses (beyond 4 Gy), RICR increased by 21%. If RICR was assumed to be constant at therapeuticdoses, the increase in RICR was 13%. Finally, if only out‐of‐treatment field organs are considered for risk estimations, RICR increased only 2%. Conclusion: Based on the risk‐dose response models that we evaluated, increased secondary cancer risk due to daily CBCTimaging during prostate IMRTtreatments was in the 2% to 21% range. Although such models were known to contain inherently large uncertainties, our study might be a plausible starting point to evaluate the effect of CBCTimagingdose on the secondary cancer risk for radiation therapy patients.
Age differences in fluid and crystallized intelligence.

Abstract The general purpose of this study was to describe differences in intellectual functioning associated with aging in adulthood. Estimates of broad factors identified as fluid intelligence, crystallized intelligence, general visualization, speediness, carefulness and fluency were obtained by combining scores on several tests found to define these factors in previous research. A sample of 297 subjects was divided into five age groupings: 14–17 year-olds, 18–20 year-olds, 21–28 year-olds, 29–39 year-olds and 40–61 year-olds. Analyses of variance and covariance were carried out on these factors and age groupings, using sex and education, as well as the factors themselves, as covariates. These analyses revealed that: (a) The mean level of fluid intelligence was systematically higher for younger adults (relative to older adults), (b) The mean level of crystallized intelligence was systematically higher for older adults (relative to younger adults), (c) The mean for the general visualization function was highest for the grouping of 21–28 year-olds and the means systematically dropped off on either side of the high value, (d) No systematic age trends were discernible for the general speediness, carefulness and fluency factors. These results provided support for the theory of fluid and crystallized intelligence.
Estrogenic and antiestrogenic activities of 16α- and 2-hydroxy metabolites of 17β-estradiol in MCF-7 and T47D human breast cancer cells

Abstract The comparative mitogenic activities of 17β-estradiol (E2) and four metabolites, 2-hydroxyestradiol (2-OHE2), 2-hydroxyestrone (2-OHE1), 16α-hydroxyestradiol (16α-OHE2) and 16α-hydroxyestrone (16α-OHE1) were determined in estrogen receptor (ER)-positive MCF-7 and T47D human breast cancer cells. E2 (1 nM) induced a 7- to 13-fold increase in cell number in both cell lines compared to untreated cells and the mitogenic potencies of 16α-OHE1 or 16α-OHE2 were comparable to or greater than E2. In contrast, 2-OHE1 and 2-OHE2 were weak mitogens in both cell lines and in cells cotreated with 1 nM E2 and 100 or 1000 nM 2-OHE1 or 2-OHE2, there was a significant inhibition of hormone-induced cell proliferation. The comparative ER agonist/antagonist activities of E2 and the metabolites on transactivation were determined in T47D cells transiently transfected with constructs containing promoter inserts from the cathepsin D (pCD) and creatine kinase B (pCKB) genes. E2, 16α-OHE2 and 16α-OHE1 induced reporter gene activity in both MCF-7 or T47D cells transfected with pCKB or pCD. In contrast, 2-OHE1 and 2-OHE2 did not exhibit ER agonist activity for these transactivation assays, but in cells cotreated with E2 plus 2-OHE1 or 2-OHE2, there was a significant decrease in the hormone-induced response. These results demonstrate that 16α-OHE1/16α-OHE2 exhibit estrogenic activities similar to that observed for E2, whereas the 2-catecholestrogens are weak ER agonists (cell proliferation) or antagonists (cell proliferation and transactivation).
A comprehensive mapping of HIV-1 genotypes in various risk groups and regions across China based on a nationwide molecular epidemiologic survey.

Background China is experiencing a dynamic HIV/AIDS epidemic. While serology based surveillance systems have reported the spread of HIV/AIDS, detailed tracking of its transmission in populations and regions is not possible without mapping it at the molecular level. We therefore conducted a nationwide molecular epidemiology survey across the country. Methods HIV-1 genotypes were determined from 1,408 HIV-positive persons newly diagnosed in 2006. The prevalence of each genotype was estimated by weighting the genotype’s prevalence from each province- and risk-specific subpopulation with the number of reported cases in the corresponding subgroups in that year. Results CRF07_BC (35.5%), CRF01_AE (27.6%), CRF08_BC (20.1%), and subtype B' (9.6%) were the four main HIV-1 strains in China. CRF07_BC and CRF08_BC were the primary drivers of infection among injecting drug users in northeastern and southeastern China, respectively, and subtype B' remained dominant among former plasma donors in central China. In contrast, all four strains occurred in significant proportions among heterosexuals nationwide, pointing to an expansion of the HIV-1 epidemic from high-risk populations into the general population. CRF01_AE also replaced subtype B as the principal driver of infection among men-who-have-sex-with-men. Conclusions Our study provides the first comprehensive baseline data on the diversity and characteristics of HIV/AIDS epidemic in China, reflecting unique region- and risk group-specific transmission dynamics. The results provide information critical for designing effective prevention measures against HIV transmission.
A Phase Sensitive Scanning Optical Microscope

We describe a new type of electronically-scanned confocal optical microscope which is very well suited to surface metrology. A laser beam incident on a wideband Te02 Bragg cell produces both a stationary beam which is used as a local phase reference and a scanned beam which is frequency-shifted; these are used in an AC interferometer. The system produces an RF output whose amplitude is that of the scanned beam, and whose phase is the optical phase difference of the two beams. Optical phase and amplitude can then be measured separately with standard RF techniques. Phase accuracy is about 10 . Transverse edge resolution (10%-90%) of 230 nm has been obtained (with λ = 514.5 nm) , which is in good agreement with the prediction of the simple theory. The data has been deconvolved to enhance the edge resolution, resulting in an ultimate resolution of 130 nm at the expense of introducing ripple into the edge response.
Portal control of viral prohead expansion and DNA packaging

Bacteriophage T4 terminase packages DNA in vitro into empty small or large proheads (esps or elps). In vivo maturation of esps yields the more stable and voluminous elps required to contain the 170 kb T4 genome. Functional proheads can be assembled containing portal-GFP fusion proteins. In the absence of terminase activity these accumulated in esps in vivo, whereas wild-type portals were found in elps. By nuclease protection assay dsDNAs of lengths 0.1, 0.2, 0.5, 5, 11, 20, 40 or 170 kb were efficiently packaged into wild-type elps in vitro, but less so into esps and gp20-GFP elps; particularly with DNAs shorter than 11 kb. However, 0.1 kb substrates were equally efficiently packaged into all types of proheads as judged by fluorescence correlation spectroscopy. These data suggest the portal controls the expansion of the major capsid protein lattice during prohead maturation, and that this expansion is necessary for DNA protection but not for packaging.
NCAM in the differentiation of embryonic lens tissue

The role of the neural cell adhesion molecule (NCAM)2 in ocular lens differentiation was investigated in chicken embryos. Changes in expression of NCAM were documented by immunohistology of frozen sections. This analysis revealed that NCAM diminished during lens fiber differentiation, in contrast to the gap junction-associated protein MP26 which became more abundant. The form of NCAM expressed was determined by Western blot analysis of proteins extracted from the different regions of the Embryonic Day 6 lenses. All regions expressed NCAM with an apparent molecular weight of 140 kDa and relatively low levels of polysialylation. The function of NCAM in lens differentiation was investigated using antibodies that inhibit NCAM-mediated adhesion. Two parameters that change during maturation of the lens epithelial cells were monitored: the thickness of the tissue, indicating the length of lens cells, and the particle arrangement of gap junctions, reflecting the state of junctional differentiation. When epithelial cell explants of Embryonic Day 6 lenses were cultured for 5 days, the cells elongated and displayed an increase in the loose, random intramembranous particle arrangements characteristic of maturing lens fiber gap junctions. When the explants were cultured in the presence of anti-NCAM Fabs, the epithelia were thinner than in matched controls and had particle arrangements characteristic of a less mature state. The expression of NCAM during lens differentiation and the effects of attenuating NCAM function suggest that adhesion mediated by NCAM is an essential event in lens cell differentiation.