cssi/SciSciGPT-SciSciNet huggingface dataset:
Region growing for multi-route cuts

We study a number of multi-route cut problems: given a graph G = (V, E) and connectivity thresholds k(u, v) on pairs of nodes, the goal is to find a minimum cost set of edges or vertices the removal of which reduces the connectivity between every pair (u, v) to strictly below its given threshold. These problems arise in the context of reliability in communication networks; They are natural generalizations of traditional minimum cut problems where the thresholds are either 1 (we want to completely separate the pair) or ∞ (we don't care about the connectivity for the pair). We provide the first non-trivial approximations to a number of variants of the problem including for both node-disjoint and edge-disjoint connectivity thresholds. A main contribution of our work is an extension of the region growing technique for approximating minimum multicuts to the multi-route setting. When the connectivity thresholds are either 2 or ∞ (the "2-route cut" case), we obtain polylogarithmic approximations while satisfying the thresholds exactly. For arbitrary connectivity thresholds this approach leads to bicriteria approximations where we approximately satisfy the thresholds and approximately minimize the cost. We present a number of different algorithms achieving different cost-connectivity tradeoffs.
Replicating financial market dynamics with a simple self-organized critical lattice model

Abstract We explore a simple lattice field model intended to describe statistical properties of high-frequency financial markets. The model is relevant in the cross-disciplinary area of econophysics. Its signature feature is the emergence of a self-organized critical state. This implies scale invariance of the model, without tuning parameters. Prominent results of our simulation are time series of gains, prices, volatility, and gains frequency distributions, which all compare favorably to features of historical market data. Applying a standard GARCH(1,1) fit to the lattice model gives results that are almost indistinguishable from historical NASDAQ data.
Application of Chemoenzymatic Hydrolysis in the Synthesis of 2-Monoacylglycerols.

Abstract The selective biocatalyzed synthesis of 2-monoacylglycerols (2-MAGs) through the use of commercially available immobilized Candida antarctica (Novozym435) and Rhizomucor miehei is explored. Reactions at room temperature result in the formation of a 2-MAG and a corresponding ethyl ester of the fatty acid with immobilized C. antarctica within 2 h with yields ranging from 36% to 83%. Similar reaction conditions with immobilized R. miehei yielded exclusively the 2-MAG after 24 h with yields ranging from 37% to 88%. Yields vary on the acyl group at the sn -2 position and choice of enzyme involved.
SUPRAMOLECULAR ARSENIC COORDINATION CHEMISTRY

A flurry of research activity has emerged in recent years resulting in reliable strategies for the formation of spectacular self-assembled metal-ligand clusters and capsules. Main group ions have not shared in this burst of activity. In fact, ions in this part of the periodic table have largely been overlooked for use as directing elements in self-assembly reactions, despite the need for improved chelators for main group ions for a variety of applications. This review surveys our approach to developing design strategies to prepare self-assembled nanoscale supramolecular complexes containing main group ions, with a particular emphasis on supramolecular arsenic(III) coordination chemistry.
Characterization of LPE Grown HgCdTe by Ion Scattering Spectrometry.

Abstract Results are shown here for low energy ion scattering spectrometry (ISS) experiments on compound semiconductors such as mercury cadmium telluride (HgCdTe) grown by liquid phase epitaxy (LPE) on CdTe substrates. By proper etching of the substrates and control of epitaxial growth conditions, surfaces of the zinc blende sphalerite structure may be obtained in which {111] faces have a top layer of cadmium and mercury (A sites) or of tellurium (B sites). Ion scattering experiments at low energies (500 V or less) on epitaxial HgCdTe shown only A or B sites. However, when the bombarding ion beam potential is raised to values conventionally used (1500–2500 V), then energy losses from both A and B atoms are observed. At these higher energies the ions displace the outer atoms or tunnel through to interact with atoms in the second layer. Spectra obtained at these higher energies shown interesting fine structure which suggest that energy losses are occurring in multiple collisions and nonbinary scattering. Scattered ion yield curves, which for some elements show oscillatory fine structure, are dramatically different for A and B surfaces. Even though these yield curves are very complicated because of the structure and number of elements, the fine structure may prove useful for further understanding of interaction of neighboring atoms. Yield curves along with conventional low energy ion scattering spectra provide a unique method of analysis of the outermost atomic layer of epitaxial films.
Facile High-Yielding Synthesis of Symmetric Esters of Methylenebisphosphonic Acid.

Abstract The 1H-tetrazole catalyzed coupling of methylenebis(phosphonic dichloride), CH2(POCl2)2, with primary alkyl, cyclic secondary alkyl, aromatic, and silicon- and fluorine-containing alcohols selectively affords symmetric P,P′-dialkyl partial esters as well as homoleptic and mixed tetraesters. Two partial ester intermediates, methylenebis(2-ethylhexyl phosphonic chloride) and 2-ethylhexyl methylenebisphosphonic trichloride, were observed by 1H- and 31P NMR spectroscopy in the esterification of CH2(POCl2)2 with 2-ethyl-1-hexanol.
Forced convection cell circulation in clear air

The characteristics of a two-dimensional convection cell with an applied heat force are derived from the equations of motion, continuity, and the first law of thermodynamics. The solutions are compared with observations made over the water north of Puerto Rico. It is found theoretically that large, slow-moving cells can always exist, and will persist for one to two hours.
The Effects of Personality Traits on the Perception of Written Mass Communication

In the perception of mass communication, different personality traits favor reader-oriented and company-oriented advertisements. Experimental results also suggest that personality types (extraverts...
Experimental Study of an Impingement Cooling Jet Array Using an Infrared Thermography Technique

An experimental test facility has been designed, constructed, and commissioned for studying the convective heat transfer of an array of 55 impingement jets with a constant heat flux boundary condition. Spatial variation in time averaged Nusselt number as well as spanwise time averaged Nusselt number are presented for jet Reynolds numbers of 4,000, 8,000, 12,000, and 15,000 for a jet to target standoff distance of z/D=3. For each of these configurations the exit flow has also been varied to include both a single exit and double exit configuration. The time and overall area averaged Nusselt number is presented as a function of jet Reynolds number. The results show that the time averaged Nusselt number increases with increasing jet Reynolds number in both the local and spanwise averaged values. The single exit configuration provides lower values of local and spanwise averaged Nusselt number for all jet Reynolds numbers studied compared to the double exit configuration. This reduction is caused by more cross flow accumulation while it moves toward the exit.
An online tutor for astronomy: The GEAS self-review library

AbstractWe introduce an interactive online resource for use by students and college instructors in introductory astronomy courses. The General Education Astronomy Source (GEAS) online tutor guides students developing mastery of core astronomical concepts and mathematical applications of general astronomy material. It contains over 12,000 questions, with linked hints and solutions. Students who master the material quickly can advance through the topics, while underprepared or hesitant students can focus on questions on a certain topic for as long as needed, with minimal repetition. Students receive individual accounts for study and course instructors are provided with overview tracking information, by time and by topic, for entire cohorts of students. Diagnostic tools support self-evaluation and close collaboration between instructor and student, even for distance learners. An initial usage study shows clear trends in performance which increase with study time, and indicates that distance learners using th...
Objectives and problems in simulating computers

Because the effort required to simulate a computer system is often very great, analysts should consider carefully the probable value of the results prior to embarking on it. Special languages have been created to aid the programmer in reducing the time required to code a simulation, and analysis techniques are available to reduce time requirements in the later phases of a study. Still, unexpected problems usually arise: An effort concludes with a study only partly completed because budgeted resources have been exhausted, or the results may be of less value than anticipated. If the analyst can foresee problems prior to commencing the detailed coding phase of a study, he can avoid many of the problems, mitigate many of the remainder, and allow for the rest in anticipating the payoffs of the effort.
Thin silicon nitride films to increase resolution in e-beam lithography

A physical method of reducing feature size and proximity effects in sub-quarter-micrometer e-beam lithography is described. A thin layer (50 to 300 nm) of silicon nitride deposited on a semiconductor substrate, prior to resist deposition, has been found to enhance the resist resolution. The samples were patterned with a 50-keV, 15-nm-diam probe generated by a JEOL JBX-5Dll e-beam lithography system. Point spread function measurements in 60-nm-thick SAL-601 on Si are shown to illustrate the resolution enhancement in the nanolithographic regime (sub-100 nm). The technique has been applied to lithography on 400-nm-thick W films, such as would be used in x-ray mask fabrication. The 200 nm of SAL-601 was spun onto W film samples, which were half-coated with 200 nm of silicon nitride. Identical lithographic patterns were written on each half of the sample. On examination of the samples after postexposure processing and development, reduced feature sizes and proximity effects were seen on the sample half with the silicon nitride intermediary layer. For example, in a field effect transistor (FET) type pattern, with a coded 500-nm gap between the source and drain pads, the gate could only be successfully resolved when the intermediary nitride layer was present. Monte Carlo simulations were performed on a CM-200 connection machine. The results show a large number of fast secondary electrons are generated within a 100-nm radius of the incident electron beam. The implications of fast secondary electrons on resolution in e-beam lithography are discussed. The total number of fast secondary electrons entering the resist is reduced by the silicon nitride layer. Simulations compare the thin-layer technique to a bilayer resist technique, used to improve resolution at larger dimensions.
Robust Line Estimation with Errors in Both Variables

Abstract The estimator holding the central place in the theory of the multivariate “errors-in-the-variables” (EV) model results from performing orthogonal regression on variables rescaled according to the covariance matrix of the errors. Our simulations on the univariate model essentially relegate this estimator to use only in large samples on data with no trace of outlier contamination. A modification requiring a robust preliminary slope is proposed that essentially sets out the generalization to EV of the robust w-estimator in regression. It is demonstrated that the modification is robust to outlier contamination even in small samples, given a sufficiently good preliminary estimator. Candidates for a preliminary slope estimator based on the data are discussed and the performance of one under simulation is examined.
Neurobiological Basis of Speech: A Case for the Preeminence of Temporal Processing

In this paper we present evidence supporting the hypothesis that a basic temporal processing impairment in language-impaired children underlies their inability to integrate sensory information that converges in rapid succession in the central nervous system. We provide data showing that this deficit is pansensory; that is, affects processing in multiple sensory modalities, and also affects motor output within the millisecond time frame. We also provide data that links these basic temporal integration deficits to specific patterns of speech perception and speech production deficits in language-impaired children. We suggest that these basic temporal deficits cause a cascade of effects starting with disruption of the normal development of an otherwise effective and efficient phonological system. We propose further that these phonological processing deficits result in subsequent failure to learn to speak and to read normally. That is, both the language and reading problems have their basis in deficiently esta...
Thiomidoyl approach to the synthesis of α-sialosides

Novel sialosyl donors, S-benzoxazolyl (SBox) and S-thiazolyl (STaz) sialosides, have been synthesized and applied to the stereoselective synthesis of α-sialosides. It was also demonstrated that it is possible to selectively activate SBox sialyl donor over ethyl thioglycoside, allowing the direct synthesis of disaccharide donors that could be used in subsequent glycosylations without further manipulations.
Unbalanced expanders and randomness extractors from Parvaresh--Vardy codes

We give an improved explicit construction of highly unbalanced bipartite expander graphs with expansion arbitrarily close to the degree (which is polylogarithmic in the number of vertices). Both the degree and the number of right-hand vertices are polynomially close to optimal, whereas the previous constructions of Ta-Shma et al. [2007] required at least one of these to be quasipolynomial in the optimal. Our expanders have a short and self-contained description and analysis, based on the ideas underlying the recent list-decodable error-correcting codes of Parvaresh and Vardy [2005].Our expanders can be interpreted as near-optimal “randomness condensers,” that reduce the task of extracting randomness from sources of arbitrary min-entropy rate to extracting randomness from sources of min-entropy rate arbitrarily close to 1, which is a much easier task. Using this connection, we obtain a new, self-contained construction of randomness extractors that is optimal up to constant factors, while being much simpler than the previous construction of Lu et al. [2003] and improving upon it when the error parameter is small (e.g., 1/poly(n)).
Cross-reactive chemical sensor arrays.

Conventional approaches to chemical sensors have traditionally made use of a “lock-and-key” design, wherein a specific receptor is synthesized in order to strongly and highly selectively bind the analyte of interest.1-6 A related approach involves exploiting a general physicochemical effect selectively toward a single analyte, such as the use of the ionic effect in the construction of a pH electrode. In the first approach, selectivity is achieved through recognition of the analyte at the receptor site, and in the second, selectivity is achieved through the transduction process in which the method of detection dictates which species are sensed. Such approaches are appropriate when a specific target compound is to be identified in the presence of controlled backgrounds and interferences. However, this type of approach requires the synthesis of a separate, highly selective sensor for each analyte to be detected. In addition, this type of approach is not particularly useful for analyzing, classifying, or assigning human value judgments to the composition of complex vapor mixtures such as perfumes, beers, foods, mixtures of solvents, etc.
Inverse Hyperbolic Problems with Time-Dependent Coefficients

We consider the inverse problem for the second order self-adjoint hyperbolic equation in a bounded domain in R n with lower order terms depending analytically on the time variable. We prove that, assuming the BLR condition, the time-dependent Dirichlet-to-Neumann operator prescribed on a part of the boundary uniquely determines the coefficients of the hyperbolic equation up to a diffeomorphism and a gauge transformation. As a by-product we prove a similar result for the nonself-adjoint hyperbolic operator with time-independent coefficients.
Injective Hopf bimodules, cohomologies of infinite dimensional Hopf algebras and graded-commutativity of the Yoneda product

Abstract We prove that the category of Hopf bimodules over any Hopf algebra has enough injectives, which enables us to extend some results on the unification of Hopf bimodule cohomologies of [R. Taillefer, PhD thesis, 2001; arXiv preprint math.QA/0005019 ] to the infinite dimensional case. We also prove that the cup-product defined on these cohomologies is graded-commutative. Unlike the algebra case (see [S. Schwede, J. Reine Angew. Math. 498 (1998) 153–172]), these methods do not give a non-trivial Gerstenhaber algebra structure on the cohomology we consider. We also comment that the other approach to finding such a structure that we know of (see [M. Farinati, A. Solotar, arXiv preprint math.KT/0207243 ]) also gives a trivial Gerstenhaber algebra structure.
Thermomodulation spectra of high-energy interband transitions in Cu, Pd, Ag, Pt, and Au

Thermotransmission and thermoreflectance spectra were obtained for Cu, Pd, Ag, Pt, and Au in the 10-30 eV spectral region. Structures due to transitions from the Fermi level to high-density bands 15 eV above the Fermi level were identified in Pt. All metals showed structures arising from interband transitions between the $d$ bands and the same flat bands, 15-20 eV above the Fermi energy. Attempts to fit to interband critical points in Au revealed over 40 possible critical points in the region of these structures, most of them near the Brillouin-zone centers. Systematic trends in the series of metals make the qualitative identification of the structures more secure, and no energy shifts of calculated energy bands are required. The observed widths of structures are sometimes much narrower than the widths of free-electron-like bands at comparable energies.
Toward Human-Level Machine Intelligence

Summary form only given. Can machines think? This question has been an object of spirited discussion and debate since the birth of the computer age in the late forties of the last century. My interest in the question goes back to the beginning of my academic career. A paper of mine entitled "Thinking Machines - A New Field in Electrical Engineering," was published in the January 1950 issue of Columbia Engineering Quarterly, six years before AI was born.
Gear Fault Diagnostics Integrated in the Motion Servo Drive for Electromechanical Actuators

This paper presents contributions made in gear fault diagnostics for motion servos with continuously variable speed as used for aerospace and automotive electromechanical actuators. As the first step for motion servo diagnostics, an observer-based kinematic error estimator is developed whereby this estimated kinematic error is proposed as an operating point-independent gear surface fault signature. As the second step, a signal processing method is developed for real-time implementation of spatial domain resampling of regular time domain samples, and this method is combined with spatial domain synchronous averaging methods, which are shown to be very effective in filtering out unwanted asynchronous signatures. Lastly, a motion servo actuator with a gear surface failure is tested, and the proposed methods are shown to successfully extract the kinematic error profiles of the defective gear during motion servo operation over a wide range of continuously varying velocity.
Magnetic probing of planetary interiors

Abstract The following general question is addressed: what can be learned about a planetary interior from measurements of the global planetary magnetic field at (or near) its surface? The discussion is placed in the context of Earth, for clarity, but the considerations apply to terrestrial planets in general (so long as the observed magnetism is either predominantly of internal origin, or else external source effects can be successfully filtered out of the observations). Attention is given to the idealized but typical situation of a rotating but spherically symmetric planet containing a highly conducting uniform fluid core surrounded by a nearly insulating rigid mantle, whose conductivity, a function of at most radius only, falls monotonically from its largest value at the base of the planetary mantle to zero at the planetary surface; the largest value of mantle conductivity as well as the mean value for the whole mantle and the mantle conductance are assumed small compared to the corresponding values of the core. Exterior to the planet is vacuum in the sense of an electrically uncharged insulator. The core fluid is inviscid, Boussinesq and gravitationally driven. Complete and perfect observations of either the instantaneous internal vector magnetic field together with its secular variation at a single epoch, or more realistically, the instantaneous internal vector magnetic field alone at two separated epochs are presumed available; the time separation between measurement epochs is long compared the Ohmic diffusion time of the planetary mantle, but small compared to that of the liquid core. Under such circumstances we describe how information about each of the following planetary properties can, in principle (though not without practical difficulty) be retrieved from the observations: (1) depth of the core-mantle boundary (a result of Hide); (2) depth to the current and motion sources responsible for the planetary dynamo; (3) presence or absence of small-scale turbulence in the upper reaches of the core; (4) large-scale horizontal fluid motion at the top of the core; (5) strength of horizontal currents, zonal magnetic fields, Coriolis and Lorentz forces at the top of the core; and (6) current system in the mantle and strength of electromagnetic core-mantle coupling.
Topological superconductors as nonrelativistic limits of Jackiw-Rossi and Jackiw-Rebbi models

We argue that the nonrelativistic Hamiltonian of ${p}_{x}+i{p}_{y}$ superconductor in two dimensions can be derived from the relativistic Jackiw-Rossi model by taking the limit of large Zeeman magnetic field and chemical potential. In particular, the existence of a fermion zero mode bound to a vortex in the ${p}_{x}+i{p}_{y}$ superconductor can be understood as a remnant of that in the Jackiw-Rossi model. In three dimensions, the nonrelativistic limit of the Jackiw-Rebbi model leads to a ``$p+is$'' superconductor in which spin-triplet $p$-wave and spin-singlet $s$-wave pairings coexist. The resulting Hamiltonian supports a fermion zero mode when the pairing gaps form a hedgehoglike structure. Our findings provide a unified view of fermion zero modes in relativistic (Dirac-type) and nonrelativistic (Schr\"odinger-type) superconductors.
Selective Synthesis Combined with Chemical Separation of Single-Walled Carbon Nanotubes for Chirality Selection

Single-walled carbon nanotubes (SWNTs) are potential materials for future nanoelectronics. Since the electronic and optical properties of SWNTs strongly depend on tube diameter and chirality, obtaining SWNTs with narrow (n,m) chirality distribution by selective growth or chemical separation has been an active area of research. Here, we demonstrate that a new, bimetallic FeRu catalyst affords SWNT growth with narrow diameter and chirality distribution in methane CVD. At 600 degrees C, methane CVD on FeRu catalyst produced predominantly (6,5) SWNTs according to UV-vis-NIR absorption and photoluminescence excitation/emission (PLE) spectroscopic characterization. At 850 degrees C, the dominant semiconducting species produced are (8,4), (7,6), and (7,5) SWNTs, with much narrower distributions in diameter and chirality than materials grown by other catalysts. Further, we show that narrow diameter/chirality growth combined with chemical separation by ion exchange chromatography (IEC) greatly facilitates achieving single (m,n) SWNT samples, as demonstrated by obtaining highly enriched (8,4) SWNTs with near elimination of metallic SWNTs existing in the as-grown material.
No radial excitations in low energy QCD. I. Diquarks and classification of mesons

We propose a new schematic model for mesons in which the building blocks are quarks and flavor-antisymmetric diquarks. The outcome is a new classification of the entire meson spectrum into quark–antiquark and diquark–antidiquark states which does not give rise to a radial quantum number: all mesons which have so far been believed to be radially excited are orbitally excited diquark–antidiquark states; similarly, there are no radially excited baryons. Further, mesons that were previously viewed as “exotic” are no longer exotic as they are now naturally integrated into the classification as diquark–antidiquark states. The classification also leads to the introduction of isorons (iso-hadrons), which are analogs of atomic isotopes, and their magic quantum numbers, which are analogs of the magic numbers of the nuclear shell model. The magic quantum numbers of isorons match the quantum numbers expected for low-lying glueballs in lattice QCD. We observe that interquark forces in mesons behave substantially differently from those in baryons: qualitatively, they are color–magnetic in mesons but color–electrostatic in baryons. We comment on potential models and the hydrogen atom. The implications of our results for confinement, asymptotic freedom, and a new set of relations between two fundamental properties of hadrons—their size and their energy—are discussed in our companion paper (Eur. Phys. J. C (2013). doi: 10.1140/epjc/110052-013-2299-8 ).
Physics of breakdown in InAlAs/n/sup +/-InGaAs heterostructure field-effect transistors

InAlAs/n/sup +/-InGaAs HFET's on InP have demonstrated a high breakdown voltage in spite of the narrow bandgap of the InGaAs channel. In order to understand this unique feature, we have carried out a systematic temperature-dependent study of off-state breakdown. We find that off-state breakdown at room-temperature is drain-gate limited and that the breakdown voltage shows a negative temperature coefficient. Based on these and other findings, we propose that off-state breakdown is a two-step process. First, electrons are injected by thermionic-field emission from the gate to the insulator. Second, electrons enter into the high-field drain-gate region of the channel hot, and relax their energy through impact-ionization. This combined mechanism explains our experimental observations that off-state breakdown in InAlAs/n/sup +/-InGaAs HFET's depends both on channel and insulator design. Our findings are relevant to other InAlAs/InGaAs HFET's, such as the MODFET, as well as HFET's based on other narrow-bandgap materials. >
New fluorescent probes for carbonic anhydrases

We report the synthesis and fluorescence properties of naphthalenesulfonamide derivatives as active site probes for carbonic anhydrases.
Impact of JEDEC test conditions on new-generation package reliability

JEDEC Standard has been widely used in the electronic industry to qualify package performance under temperature and humidity conditions. Demands for high packaging density of low pin-count packages have driven the development of a new generation of packages to replace the quad flat packages (QFP). Package size has been reduced drastically. Package reflow temperature has been considerably higher due to the application of lead-free solder. Consequently, the JEDEC standard testing on these packages needs to be re-evaluated. In this paper, moisture diffusion analysis, heat transfer analysis, as well as an interface fracture mechanics-based thermomechanical analysis have been conducted. The impact of different reflow profiles was investigated. Due to the smaller package size and higher reflow temperature, the new packages are more sensitive to the reflow parameters such as peak temperature and cooling rate. For the reliability testing of the new-generation packages, modification of the JEDEC standards may be necessary to ensure that these packages are not subjected to more stringent criteria than their previous counterparts.
Spectral and temporal properties of optical signals with multiple sinusoidal phase modulations.

Optical signals generated by multiple sinusoidal temporal phase modulations (multi-FMs) applied to a monochromatic field are studied from the viewpoint of their optical spectrum and temporal modulations arising from spectral impairments. Statistical analysis based on the central limit theorem shows that the signals’ optical spectrum converges to a normal distribution as the number of modulations increases, allowing one to predict the frequency range containing a given fraction of the total energy with the associated cumulative density function. The conversion of frequency modulation to amplitude modulation is analyzed and simulated for arbitrary multi-FM signals. These developments are of theoretical and practical importance for high-energy laser systems, where optical pulses are phase modulated in the front end to smooth out the on-target beam profile and prevent potentially catastrophic damage to optical components.
THE FINE STRUCTURE OF THE RENAL GLOMERULUS OF THE MOUSE

Sections of mouse renal glomerulus fixed by perfusion with buffered osmium tetroxide solution have been studied with the electron microscope. Four components are recognized in the mouse glomerulus: epithelium, basement membrane, endothelium, and intercapillary cell. The three cellular components all display in their cytoplasm mitochondria, Golgi bodies, endoplasmic reticulum, and uncharacterized vesicles. The concepts of Hall, of Pease, and of Rhodin regarding the glomerular filtration surface are confirmed. The epithelial cells are characterized by intricate, branching, interdigitating ridge-like processes or pedicels, the summits of which press against the urinary surface of the basement membrane, covering the glomerular capillary tuft almost completely except for narrow spaces about 200 to 300 A wide between the processes. These spaces are termed the epithelial filtration slits, and are bridged by a very delicate gossamer-like membrane about 30 A thick,—the filtration slit membrane. The basement membrane is interposed everywhere between epithelial processes and endothelium, and between epithelial and intercapillary cells. The basement membrane of the filtration surface of the glomerular capillary has smooth surfaces and is about 800 A thick. It consists of three layers—a thick central lamina densa, appearing to have a very delicate felt-like structure, flanked on each side by thinner lamina rara externa and lamina rara interna. This membrane continues to the intercapillary space and makes a complicated sponge-work of varying thickness in which the intercapillary cells are enmeshed. The endothelial cells are of moderate thickness in the nuclear region, but send out thin sheet-like extensions over the filtration surface. These extensions are about 300 to 400 A thick and are characterized by numerous round endothelial filtration pores about 500 to 1000 A in diameter. The intercapillary tissue or mesangium is composed of the network of the basement membrane and the intercapillary cells. The intercapillary cells, with characteristic fine fibrillar cytoplasm, make contact with epithelial and endothelial cells and are enmeshed within the network of the basement membrane. Rounded processes of intercapillary cells penetrate into the endothelial cell through the basement membrane, and may even perforate entirely through the endothelium. Such processes are called (after Zimmermann) the intracapillary colliculi. In the endothelial cytoplasm close to the intracapillary colliculi are many dense endothelial juxtacollicular vesicles and caveolae. The cell boundaries of the endothelial cell resemble terminal bars. Some physiological speculations relating to glomerular structure are advanced. The description of Zimmermann (54), based on a light microscope study, is confirmed in many respects.
Status and New Ideas Regarding Liquid Argon Detectors

Large (up to ∼100 kt) liquid argon (LAr) time-projection chamber detectors are presently being considered for proton decay searches and neutrino astrophysics, as well as for far detectors for the next generation of long-baseline neutrino oscillation experiments that aim to determine neutrino mass hierarchy and search for CP violation in the leptonic sector. These detectors rely on the capabilities to assemble large volumes of LAr in ultrahigh-purity conditions, possibly in an underground environment, and to achieve relatively long drifts for the ionization charge. Several proposals have been developed, each of which takes a different approach to the design of the cryogenic vessels and has different scales of modularity to reach the final mass dictated by physics. New detector concepts, with innovative designs of readout electronics and novel methods for the readout of the ionization charge and scintillation light, have been proposed.
Polycyclic Aromatic Isothiocyanate Compounds as Fluorescent Labeling Reagents

Polycyclic aromatic isothiocyanates were synthesized in an attempt to produce new fluorescent agents for protein labeling and for use in microanalytical techniques. The relative fluorescence of these reagents, the required intermediates, and the derivatives were established. Of the compounds evaluated, the 9-acridine derivatives were the most promising.
Total Synthesis of Enantiopure (+)-γ -Lycorane Using Highly Efficient Pd-Catalyzed Asymmetric Allylic Alkylation

A highly efficient short total synthesis of (+)-γ-lycorane (>99% ee, 41% overall yield) was achieved by using the asymmetric allylic alkylation in the key step catalyzed by palladium complexes with novel chiral biphenol-based monodentate phosphoramidite ligands.
The Importance of Identification of the Myocardial-Specific Isoenzyme of Creatine Phosphokinase (MB Form) in the Diagnosis of Acute Myocardial Infarction

Serial plasma determinations of the isoenzymes of CPK were performed in all patients (376) admitted to a coronary care unit during a 12-month period with diagnosis of possible acute myocardial infarction. Results were compared with data from other enzyme studies and from the electrocardiogram. An attempt was made to determine the incidence of falsely positive CPK-MB (myocardial-specific form). "No acute infarction" was diagnosed in all patients in whom neither total CPK nor the isoenzymes of LDH indicated myocardial necrosis, and in whom there were no QRS changes on ECG. Incidence of falsely negative CPK isoenzyme data was also determined. All patients, in whom total CPK was transiently elevated, and LDH1 exceeded LDH2, and new QRS changes occurred, were termed "definite" acute infarction. CPK-MB form was present in all 55 of these (0% false negative). Therefore, determination of the isoenzymes of CPK by this method provides both a sensitive and specific indication of acute myocardial infarction.
Perspective: A dynamics-based classification of ventricular arrhythmias

Despite key advances in the clinical management of life-threatening ventricular arrhythmias, culminating with the development of implantable cardioverter-defibrillators and catheter ablation techniques, pharmacologic/biologic therapeutics have lagged behind. The fundamental issue is that biological targets are molecular factors. Diseases, however, represent emergent properties at the scale of the organism that result from dynamic interactions between multiple constantly changing molecular factors. For a pharmacologic/biologic therapy to be effective, it must target the dynamic processes that underlie the disease. Here we propose a classification of ventricular arrhythmias that is based on our current understanding of the dynamics occurring at the subcellular, cellular, tissue and organism scales, which cause arrhythmias by simultaneously generating arrhythmia triggers and exacerbating tissue vulnerability. The goal is to create a framework that systematically links these key dynamic factors together with fixed factors (structural and electrophysiological heterogeneity) synergistically promoting electrical dispersion and increased arrhythmia risk to molecular factors that can serve as biological targets. We classify ventricular arrhythmias into three primary dynamic categories related generally to unstable Ca cycling, reduced repolarization, and excess repolarization, respectively. The clinical syndromes, arrhythmia mechanisms, dynamic factors and what is known about their molecular counterparts are discussed. Based on this framework, we propose a computational-experimental strategy for exploring the links between molecular factors, fixed factors and dynamic factors that underlie life-threatening ventricular arrhythmias. The ultimate objective is to facilitate drug development by creating an in silico platform to evaluate and predict comprehensively how molecular interventions affect not only a single targeted arrhythmia, but all primary arrhythmia dynamics categories as well as normal cardiac excitation-contraction coupling.
The crystal structure of AphB, a virulence gene activator from Vibrio cholerae, reveals residues that influence its response to oxygen and pH.

Summary Expression of the two critical virulence factors of Vibrio cholerae, toxin-coregulated pilus and cholera toxin, is initiated at the tcpPH promoter by the regulators AphA and AphB. AphA is a winged helix DNA-binding protein that enhances the ability of AphB, a LysR-type transcriptional regulator, to activate tcpPH expression. We present here the 2.2 A X-ray crystal structure of full-length AphB. As reported for other LysR-type proteins, AphB is a tetramer with two distinct subunit conformations. Unlike other family members, AphB must undergo a significant conformational change in order to bind to DNA. We have found five independent mutations in the putative ligand-binding pocket region that allow AphB to constitutively activate tcpPH expression at the non-permissive pH of 8.5 and in the presence of oxygen. These findings indicate that AphB is responsive to intracellular pH as well as to anaerobiosis and that residues in the ligand-binding pocket of the protein influence its ability to respond to both of these signals. We have solved the structure of one of the constitutive mutants, and observe conformational changes that would allow DNA binding. Taken together, these results describe a pathway of conformational changes allowing communication between the ligand and DNA binding regions of AphB.
Neurological complications of surgery and anaesthesia

Summary Injury to the central and peripheral nervous systems is often permanent. As such, adverse neurological outcomes of surgery and anaesthesia can be devastating for patients and their families. In this article, we review the incidence, risk factors, outcomes, prevention, and treatment of a number of important neurological complications in the perioperative period.
Bunch cleaning strategies and experiments at the Advanced Photon Source

The Advanced Photon Source (APS) design incorporated a positron accumulator ring (PAR) as part of the injector chain. In order to increase reliability and accommodate other uses of the injector, APS will run with electrons, eliminating the need for the PAR, provided another method of eliminating RF bucket "pollution" in the APS is found. Satellite bunches captured from an up to 30-ns-long beam from the linac need to be removed in the injector synchrotron and storage ring. The bunch cleaning method considered here relies on driving a stripline kicker with an amplitude modulated (AM) carrier signal where the carrier is at a revolution harmonic sideband corresponding to the vertical tune.
Charged particle detection using a CMOS active pixel sensor

Active pixel sensor (APS) is a promising technology for next-generation vertex detectors. This paper discusses the design and testing of two generations of APS chips. Both are arrays of 128 by 128 pixels, each 20 by 20 /spl mu/m. Each array is divided into subarrays in which different sensor structures (4 in the first version and 16 in the second) and/or readout circuits are employed. Measurements of several of these structures under Fe/sup 55/ exposure are reported. The sensors have also been irradiated by 55 MeV protons to test for radiation damage. The radiation increases the noise and reduces the signal. The noise can be explained by shot noise from the increased leakage current, and the reduction in signal is due to charge being trapped in the epi layer. Nevertheless, the radiation effect is small for the expected exposures at RHIC and RHIC II. Finally, we describe our conception for mechanically supporting a thin silicon wafer in an actual detector.
Do better institutions improve bank efficiency? Evidence from a transitional economy

The pace of transition in China over the last two decades has led to great variation across the country in terms of institutional and financial development. In this paper, using a panel of Chinese provinces during the period 1993–2006, we empirically investigate the determinants of the efficiency of the banking sector from an institutional perspective. The most important institutional developments in China are the emergence and gradual dominance of the market economy, financial deepening, the growth of a private sector, the establishment of secure property rights, and rule of law. We find that institutional variables play an important role in affecting banking efficiencies, and that banks tend to operate more efficiently in those regions with a greater private sector presence and more property rights awareness, while the role of financial deepening and rule of law is less straightforward.
Sudakov resummation for subleading SCET currents and heavy-to-light form factors

The hard-scattering contributions to heavy-to-light form factors at large recoil are studied systematically in soft-collinear effective theory (SCET). Large logarithms arising from multiple energy scales are resummed by matching QCD onto SCET in two stages via an intermediate effective theory. Anomalous dimensions in the intermediate theory are computed, and their form is shown to be constrained by conformal symmetry. Renormalization-group evolution equations are solved to give a complete leading-order analysis of the hard-scattering contributions, in which all single and double logarithms are resummed. In two cases, spin-symmetry relations for the soft-overlap contributions to form factors are shown not to be broken at any order in perturbation theory by hard-scattering corrections. One-loop matching calculations in the two effective theories are performed in sample cases, for which the relative importance of renormalization-group evolution and matching corrections is investigated. The asymptotic behavior of Sudakov logarithms appearing in the coefficient functions of the soft-overlap and hard-scattering contributions to form factors is analyzed.
Active harmonic elimination in multilevel converters using FPGA control

This paper presents an optimal total harmonic distortion (THD) control algorithm referred to as active harmonic elimination method for cascaded H-bridges multilevel converter control with unequal DC sources. First, the multilevel converter is decoupled into unipolar converters, the low order harmonics, such as the 5th, 7th, 11th and 13th are eliminated by using elimination theory, and the minimum THD combination of unipolar converters for multilevel converter control is found. Next, the magnitudes and phases of the residual higher harmonics are computed and subtracted from the original output voltage waveform to eliminate these higher harmonics. To validate the proposed algorithm, the method is simulated by Matlab first. After the simulation, an experimental 11-level H-bridge multilevel converter with a real-time controller based on Altera FLEX 10 K field programmable gate array (FPGA) is used to implement the algorithm with 8 /spl mu/s control resolution. The experimental results show that the method can effectively eliminate the specific harmonics as expected, and the output voltage waveforms have low THD.
Finiteness of small factor analysis models

We consider factor analysis models with one or two factors. Fixing the number of factors, we prove a finiteness result about the covariance matrix parameter space when the size of the covariance matrix increases. According to this result, there exists a distinguished matrix size starting at which one can determine whether a given covariance matrix belongs to the parameter space by determining whether all principal submatrices of the distinguished size belong to the corresponding parameter space. We show that the distinguished matrix size is four in the model with one factor and six with two factors.
The NSNS front end accelerator system

The National Spallation Neutron Source (NSNS) front-end accelerator comprises a 65 keV LEBT, a 2.5 MeV RFQ and a matching accelerating a 55 mA H beam with a 6% duty factor. Critical design issues are the 6% beam duty factor, the 5 free space-wavelength long 402.5 MHz RFQ, and nanosecond chopping of the beam before it enters the first DTL. The conceptual design of the front-end systems will be presented, with experimental validation of some of the proposed subsystems.
Load Updating for Nonlinear Finite Element Models

A measurement-based load updating method for finite element models subjected to static loads was studied using a four-noded curved beam element for large displacements/rotations and a gradient-based variable metric optimizer. Finite element analysis was used to numerically calculate the geometrically linear and nonlinear responses and their sensitivities under a given load. The optimizer was used to recursively update the load so that it minimized the square of the difference between the calculated and prefiltered/noise-free measured (displacement or strain) data. For the basic studies, the extracted load was represented within an element by a linear combination of integrated Legendre polynomials, the coefficients of which were taken as design variables of the least-squares problem. Through a model order analysis, the benefits for solving load updating problems using the relative deformation measurement, the polynomials of lower orders, the elements of larger sizes (because of using the high precision four-noded beam element), and the denser measured points were studied for linear responses under different types of applied loads. It was confirmed that using the reduced number of unknown variables to obtain an overdetermined inverse problem helps get unique and stable extracted loads. Though this conclusion was verified mainly through illustrative examples for a cantilever beam, it was generally applicable to other load updating or inverse problems. Further examples were given for a three-dimensional portal frame load updating, extracting highly oscillating loads, and a strain-based cantilever beam load updating. The final examples were load updating for geometrically nonlinear finite element models under self-weight, snow, and/or pressure loads.
A SEARCH FOR DISTANT SOLAR SYSTEM BODIES IN THE REGION OF SEDNA

We present the results of a wide-field survey for distant Sedna-like bodies in the outer solar system using the 1.2 m Samuel Oschin Telescope at Palomar Observatory. We searched ~12,000 deg^2 down to a mean limiting magnitude of 21.3 in R. A total number of 53 Kuiper Belt objects and Centaurs have been detected, 25 of which were discovered in this survey. No additional Sedna-like bodies with perihelia beyond 70 AU were found despite a sensitivity to motions out to ~1000 AU. We place constraints on the size and distribution of objects on Sedna orbits.