cssi/SciSciGPT-SciSciNet huggingface dataset:
Microstructure and Electrical Properties of Chemically Prepared Nb2O5-Doped SrTiO3 Ceramics

Chemically homogeneous SrTiO{sub 3} powders of submicrometer size were obtained by alcohol dehydration and subsequent calcination of citrate/formate solutions. Nb{sub 2}O{sub 5}-doped SrTiO{sub 3} was prepared with various Sr:Ti ratios resulting in an anomalous increase in the dielectric constant. This paper reports that no semiconducting behavior was observed for donor-doped TiO{sub 2}-excess SrTiO{sub 3} when fired in air. Therefore, a brick-wall type of microstructure was formed as a result of the excess SrO, giving rise to anomalously high dielectric constants.
Smectic Liquid Crystals: Materials with One-Dimensional, Periodic Order

Smectic liquid crystals are materials formed by stacking deformable, fluid layers. Although smectics prefer to have flat, uniformly-spaced layers, boundary conditions can impose curvature on the layers. Since the layer spacing and curvature are intertwined, the problem of finding minimal configurations for the layers becomes nontrivial. We discuss various topological and geometrical aspects of these materials and present recent progress on finding some exact layer configurations. We also exhibit connections to the study of certain embedded minimal surfaces and briefly summarize some important open problems.
Sprinkler Head Revisited: Momentum, Forces, and Flows in Machian Propulsion

Many experimenters, starting with Ernst Mach in 1883, have reported that if a device alternately sucks in and then expels a surrounding fluid, it moves in the same direction as if it only expelled fluid. This surprising phenomenon, which we call Machian propulsion, is explained by conservation of momentum: the outflow efficiently transfers momentum away from the device and into the surrounding medium, while the inflow can do so only by viscous diffusion. However, many previous theoretical discussions have focused instead on the difference in the shapes of the outflow and the inflow. Whereas the argument based on conservation is straightforward and complete, the analysis of the shapes of the flows is more subtle and requires conservation in the first place. Our discussion covers three devices that have usually been treated separately: the reverse sprinkler (also called the inverse, or Feynman sprinkler), the putt–putt boat, and the aspirating cantilever. We then briefly mention some applications of Machian propulsion, ranging from microengineering to astrophysics.
Partitioning strategies for the interaction of a fluid with a poroelastic material based on a Nitsche’s coupling approach

Abstract We develop a computational model to study the interaction of a fluid with a poroelastic material. The coupling of Stokes and Biot equations represents a prototype problem for these phenomena, which feature multiple facets. On one hand, it shares common traits with fluid–structure interaction. On the other hand it resembles the Stokes–Darcy coupling. For these reasons, the numerical simulation of the Stokes–Biot coupled system is a challenging task. The need of large memory storage and the difficulty to characterize appropriate solvers and related preconditioners for the equations at hand are typical shortcomings of classical discretization methods applied to this problem, such as the finite element method for spatial discretization and finite differences for time stepping. The application of loosely coupled time advancing schemes mitigates these issues, because it allows to solve each equation of the system independently with respect to the others, at each time step. In this work, we develop and thoroughly analyze a loosely coupled scheme for Stokes–Biot equations. The scheme is based on Nitsche’s method for enforcing interface conditions. Once the interface operators corresponding to the interface conditions have been defined, time lagging allows us to build up a loosely coupled scheme with good stability properties. The stability of the scheme is guaranteed provided that appropriate stabilization operators are introduced into the variational formulation of each subproblem. The error of the resulting method is also analyzed, showing that splitting the equations pollutes the optimal approximation properties of the underlying discretization schemes. In order to restore good approximation properties, while maintaining the computational efficiency of the loosely coupled approach, we consider the application of the loosely coupled scheme as a preconditioner for the monolithic approach. Both theoretical insight and numerical results confirm that this is a promising way to develop efficient solvers for the problem at hand.
Equity and efficiency in the allocation of public housing to eligible families

Public housing has been the major approach to increasing the supply of adequate housing to low income families. The number of families who occupy public housing is only about 5 percent of those potentially eligible. Waiting lists are symptomatic of the shortage, and they would be longer still if all potentially eligible families actually applied. The short-run problem is one of allocating a very limited supply of public housing to eligible families on an equitable and efficient basis. The basis of allocation will decide which families will get public housing, and which will be left to fend for themselves, at least temporarily, in the private housing market. Current procedures place eligible families on a waiting list according to their date of application and assign them housing units as they become available. With the exception of families that have priority, waiting time becomes the basis of allocation. While waiting-time may be regarded as an equitable basis of allocation, it is not an efficient basis because it does not consider the relative preferences of families for public housing. The latter basis would house families having the strongest preferences before those having the weakest preferences because the former group would presumably suffer a greater welfare loss from exclusion then would the latter group. The hypothesis to be empirically tested is that there are differences in the relative preferences of eligible families for public housing that would be revealed if they were required to bid for housing units as they become available through vacancies or new construction. The units would be assigned in ascending order of the highest rental bids. The resulting rental schedule for occupied units would actually be established by the occupants, not the Housing Authority, and the rent paid by each would be a measure of their preference for public housing. Unsuccessful bidders would remain on the waiting list to bid again when units became available. Allocating public housing on the basis of revealed preference may satisfy efficiency, but it conflicts with equity because it does not consider waiting time or income differences among eligible f~imilies. The conflict between efficiency and equity could be resolved by a tradeoff if actual bids were weighted to reflect waiting-time and income differences; units would be assigned on the basis of weighted bids. Bidding is likely to produce a higher level of rents than now obtained from rental schedules of the Housing Authority. The average subsidy per family would decrease and more families could be subsidized.
COMPLETING ARTIN'S BRAID GROUP ON INFINITELY MANY STRANDS

A generalization of the topological fundamental group is developed in order to construct a completion of Artin's braid group on infinitely many strands with respect to the following notion of convergence: bn → id iff for each M > 0, eventually the first M strands of bn are trivial.
Two Cheers and a Pint of Worry: An On-Line Course in Political and Social Philosophy

Au cours des dix dernieres annees, de nombreuses experiences ont ete menees afin de relancer l'enseignement a distance (utilisant la video, les ordinateurs et les logiciels les plus avances). En 1995, l'Etat de New-York a vu naitre un projet d'enseignement en ligne en philosophie sociale et politique. L'A. decrit la naissance de ce projet avant d'illustrer l'organisation de ce cours et d'evaluer son efficacite
Epitaxial magnetic perovskite nanostructures

Precise arrays of sub-100 nm diameter nanodots are fabricated from magnetic oxide perovskites with the total coverage area up to 5 mm2. Epitaxial single crystal structure of the nanodots is demonstrated by cross-sectional TEM. Low temperature MFM study confirmed the ferromagnetism of the produced particles.
Elasticity and constitution of the Earth's interior

The observed variation of the seismic velocities with depth, below the crust, is examined with reference to the variation to be expected in a homogeneous medium. A general equation is derived for the variation of the quantity, , in a homogeneous gravitating layer with an arbitrary gradient of temperature. The parameters of this equation are then discussed in terms of the experimental and theoretical relations for solids. The principal parameter is (∂KT/∂P)T, the rate of change of isothermal incompressibility with pressure, which can be found for large compressions from Bridgman's measurements. Comparison of observed and expected rates of variation of ϕ throughout the Earth's interior leads to conclusions regarding homogeneity and, with a larger uncertainty, to estimates of temperature. A shadow zone at a depth of about 100 km, as suggested by Gutenberg, may be accounted for by a gradient of temperature of about 6°/km in a homogeneous layer of ultrabasic rock. Between depths of about 900 and 2,900 km, the mantle appears to be substantially uniform, and at a relatively uniform temperature of the order of several thousand degrees. Between about 200 and 900 km, the rate of rise of velocity is too great for a homogeneous layer, and indicates a gradual change of composition, or of phase, or both. New phases are required to account for the high elasticity of the deeper part of the mantle (below 900 km), and it is suggested that, beginning at about 200 to 300 km, there is a gradual shift toward high-pressure modifications of the ferro-magnesian silicates, probably close-packed oxides, with the transition complete at about 800 to 900 km. There may also be a concentration of alumina, lime, and alkalis toward the upper part of the mantle, in and above the transitional layer but below the crust, existing in minerals of high elasticity such as garnets and jadeites. The transitional layer appears to hold the key to a number of major geophysical problems. The velocities in the core and inner core are also reviewed. The inner core is most simply interpreted as crystalline iron, the outer part as liquid iron, perhaps alloyed with a small fraction of lighter elements. The density and compressibility of iron at high pressures are estimated with the aid of the experimental compressions of the alkali metals; the central density is found to be about 15. Several other recent proposals regarding the crust are discussed.
Laser diffraction methods for high temperature strain measurements

Optical methods, utilizing the interference fringes produced by diffraction of a laser light beam passing through a narrow slit, have been investigated for strain measurements at high temperatures above 1000°C. Two methods are reviewed, one suitable for dynamic loading conditions and the other for slow rate and static loading conditions. The basic principles of the methods, new instrumentation, and new measurement techniques are described. Experimental verification of the basic optical theory, system calibration, results of cross calibrations with foil strain gage, and sample applications at high temperatures are presented. Test results show that both methods are capable of performing accurate and reliable strain measurements at high temperatures.
Multiple Resolution Representation and Probabilistic Matching of 2-D Gray-Scale Shape

One approach to pattern classification is to match a structural description of a pattern to models which describe the structural properties of pattern classes. The central problem in structural pattern matching is to determine the correspondence between the symbols which comprise a model and symbols which describe a pattern. The difficulty of determining this correspondence depends critically on the representation that is used to describe patterns. This correspondence presents a probabilistic representation for structural models of pattern classes. Both pattern descriptions and models for pattern classes are based on symbols which represent grayscale information at multiple resolutions. A pattern description is given by a tree of symbols with attribute values. Structural models are represented by a tree of symbols with probabilistic attributes. The position and scale (resolution) of the symbols, as well as other ``features,'' are represented by these attributes. An algorithm is presented for determining the correspondence between symbols in a description of a pattern and symbols in a model of a pattern class. This algorithm uses the connectivity between symbols at different scales to constrain the search for correspondence. An interactive training program for learning models of pattern classes is described, and some conclusions from the work are presented.
Pair Production Absorption Troughs in Gamma-Ray Burst Spectra: A Potential Distance Discriminator

In order to explain the emergence of a high-energy continuum in gamma-ray bursts detected by EGRET, relativistic bulk motion with large Lorentz factors has recently been inferred for these sources regardless of whether they are of Galactic or cosmological origin. This conclusion results from calculations of internal pair production opacities in bursts that usually assume an infinite power-law source spectrum for simplicity, an approximation that is quite adequate for some bursts detected by EGRET. However, for a given bulk Lorentz factor Γ, photons above the EGRET range can potentially interact with sub-MeV photons in such opacity calculations. Hence it is essential to accurately address the spectral curvature in bursts seen by BATSE and also treat the X-ray paucity that is inferred from low-energy fluxes observed in the X-ray band. In this paper we present the major properties induced in photon-photon opacity considerations by such spectral curvature. The observed spectral breaks around 1 MeV turn out to be irrelevant to opacity in cosmological bursts, but they are crucial to estimates of source transparency in the 1 GeV-1 TeV range for sources located in the Galactic halo. We find that broad absorption troughs can arise at these energies for suitable bulk motion parameters Γ. Such troughs are probably an unambiguous signature of a Galactic halo population and if observed by experiments such as Whipple, MILAGRO, and GLAST, would provide powerful evidence that such bursts are not at cosmological distances.
A Counterexample for Subadditivity of Multiplier Ideals on Toric Varieties

We construct a 3-dimensional complete intersection toric variety on which the subadditivity formula doesn't hold, answering negatively a question by Takagi and Watanabe. A combinatorial proof of the subadditivity formula on 2-dimensional normal toric varieties is also provided.
SCALAR CURVATURE, MOMENT MAPS, AND THE DELIGNE PAIRING

In this paper, we improve the bound for the moment map derivative proved by Donaldson in his recent proof of the Hilbert-Mumford stability of complex manifolds with constant scalar curvature. The proof depends on the identification of Donaldson's symplectic form with the curvature of a certain Deligne pairing.
2-Arylindene metallocenes: conformationally dynamic catalysts to control the structure and properties of polypropylenes.

Polymerization of propylene with catalysts derived from unbridged 2-arylindene metallocenes leads to elastomeric, low-tacticity polypropylenes. The polymerization behavior of these conformationally dynamic catalyst systems is interpreted in terms of a multistate mechanism where the catalyst enchains the monomer from both stereoselective and nonstereoselective conformations during the lifetime of a single polymer chain. The structure and properties of the polypropylenes depend sensitively on the metallocene and the polymerization conditions (temperature, pressure, monomer concentration); samples of low to intermediate isotacticity ([mmmm] = 20−40%) are elastomeric, with low densities and broad melting ranges that extend to 150 °C. Samples of higher tacticity ([mmmm] = 40−70%) behave as softened thermoplastics.
Monoclonal gammopathies of undetermined significance.

The monoclonal gammopathies include multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS), primary systemic amyloidosis (AL), and Waldenstrom's macroglobulinemia (WM). At Mayo Clinic, almost 60% of patients with a monoclonal gammopathy have MGUS. MGUS is characterized by the presence of a serum monoclonal protein value
Amorphization of C-implanted Fe(Cr) alloys

Abstract The amorphous phase formed by implanting C into Fe alloyed with Cr, which is a prototype for the amorphous phase formed by implanting C into stainless steels, is compared to that formed by implanting C and Ti into Fe and steels. The composition range of the phase has been examined; higher Cr and C concentrations are required than needed with Ti and C. The friction and wear benefits obtained by implanting stainless steels with C only do not persist for the long durations and high wear loads found with Ti and C. However, the amorphous FeCrC alloys exhibit good aqueous corrosion resistance.
Duality, quotients, and currents

Abstract We study the generalization of R → 1/R duality to arbitrary conformally invariant σ-models with an isometry. We show that any pair of dual σ-models can be represented as quotients of a self-dual σ-model obtained by gauging different combinations of chiral currents. This observation is used to clarify the interpretation of the generalized duality as a symmetry of conformal field theory. We extend these results to N = 2 supersymmetric σ-models.
A general organic catalyst for asymmetric addition of stabilized nucleophiles to acyl imines

Abstract Cinchona alkaloid-derived thiourea catalysts promote nucleophilic additions to acyl imines for the asymmetric synthesis of secondary amine adducts. The hydroquinine-derived thiourea catalyst efficiently promotes the aza-Henry reaction of nitroalkane with acyl imines, affording β-nitroamines in good yields with enantioselectivities of 90–98% ee and diastereoselectivities up to 97%. The scope of the reaction also includes dimethyl malonate as a nucleophile to access β-amino esters in high enantiopurity. Under the optimized reaction conditions, secondary amine adducts of high enantiopurity are generated based on various aromatic and α,β-unsaturated acyl imines.
Human-centered robotics and interactive haptic simulation

A new field of robotics is emerging. Robots are today moving towards applications beyond the structured environment of a manufacturing plant. They are making their way into the everyday world that people inhabit. The paper focuses on models, strategies, and algorithms associated with the autonomous behaviors needed for robots to work, assist, and cooperate with humans. In addition to the new capabilities they bring to the physical robot, these models and algorithms and more generally the body of developments in robotics is having a significant impact on the virtual world. Haptic interaction with an accurate dynamic simulation provides unique insights into the real-world behaviors of physical systems. The potential applications of this emerging technology include virtual prototyping, animation, surgery, robotics, cooperative design, and education among many others. Haptics is one area where the computational requirement associated with the resolution in real-time of the dynamics and contact forces of the virtual environment is particularly challenging. The paper describes various methodologies and algorithms that address the computational challenges associated with interactive simulations involving multiple contacts and impacts between human-like structures.
Line Broadening in Field Metal-Poor Red Giant and Red Horizontal Branch Stars

We report 349 radial velocities for 45 metal-poor field red giant branch (RGB) and red horizontal branch (RHB) stars, with time coverage ranging from 1 to 21 years. We have identified one new spectroscopic binary, HD 4306, and one possible such system, HD 184711. We also provide 57 radial velocities for 11 of the 91 stars reported in our previous work. All but one of the 11 stars had been found to have variable radial velocities. New velocities for the long-period spectroscopic binaries BD−1 2582 and HD 108317 have extended the time coverage to 21.7 and 12.5 years, respectively, but in neither case have we yet completed a full orbital period. As was found in the previous study, radial velocity jitter is present in many of the most luminous stars. Excluding stars showing spectroscopic binary orbital motion, all 7 of the red giants with estimated MV values more luminous than −2.0 display jitter, as well as 3 of the 14 stars with −2.0 < MV ≤ −1.4. We have also measured the line broadening in all the new spectra, using synthetic spectra as templates. Comparison with results from high-resolution and higher signal-to-noise (S/N) spectra employed by other workers shows good agreement down to line-broadening levels of 3 km s−1, well below our instrumental resolution of 8.5 km s−1. As the previous work demonstrated, the majority of the most luminous red giants show significant line broadening, as do many of the red horizontal branch stars, and we briefly discuss possible causes. The line broadening appears related to velocity jitter, in that both appear primarily among the highest luminosity red giants.
Challenges for superstring cosmology

Abstract We consider whether current notions about superstring theory below the Planck scale are compatible with cosmology. We find that the anticipated form for the dilaton interaction creates a serious roadblock for inflation and makes it unlikely that the universe ever reaches a state with zero cosmological constant and time-independent gravitational constant.
Characterization of proteolytic activity during senescence in daylilies

From 12 to 24 h after the opening of daylily flowers (Hemerocallis hybrid cv. Stella d'Oro), the petals begin to degrade and the protein levels of soluble, microsomal- and plastid-enriched fractions decrease by 50%, on a per petal basis. To help determine some of the components for the cell death program in daylily petals, we studied the mechanisms that regulate this loss of protein. Enzyme activities capable of digesting native daylily protein, gelatin, and azocasein markedly increase after flower opening, and their appearance is inhibited by the translation inhibitor, cycloheximide. Protein hydrolysis in vitro is prevented by inhibitors of cysteine, serine and metalloproteinases. Immunoblots using antibodies to ubiquitin pathway enzymes indicate that the ubiquitin system is not senescence specific. However, ion leakage is delayed by two inhibitors of the 26S proteasome. We propose that programmed cell death in daylily petals may involve the increase in activity of at least three classes of proteinases, and discuss the possibility that these proteinases may operate in concert with the ubiquitin pathway.
Enantioselective Diels–Alder reactions of 3-(acyloxy)acrylates

Abstract Diels-Alder reactions with 3-(acyloxy)acrylates using chiral Lewis acid catalysts have been successfully carried out. These reactions proceed with high enantioselectivity when a chiral Lewis acid derived from Cu(OTf)2 and a bisoxazoline is used. The facility of the reaction is dependent on the nature of the acyloxy group in the dienophile.
Reliability assessment of microvias in HDI printed circuit boards

Accelerating adoption of CSP and flip-chip area array packaging for high performance and hand-held applications is the main driving force for high-density substrates and printed circuit boards. At the Packaging Research Center, Georgia Institute of Technology (PRC-GT), ultra-fine line high density interconnect (HDI) substrate technology is being developed as part of the system-on-a-package (SOP) research and testbed efforts to meet these emerging requirements. To be adopted by industry, this novel technology must demonstrate the critical elements of high reliability and low cost processing. The HDI and microvias structures discussed in this paper were fabricated on high Tg organic substrates using a sequential build-up process, and were subject to extensive liquid to liquid thermal shock testing. All 75 /spl mu/m microvias and above successfully passed 2000 cycles without failure, and first failure occurred at 1000 cycles for 50 /spl mu/m microvias on a 50 /spl mu/m thick dielectric layer. Microvia down to 25 /spl mu/m diameter on a 25 /spl mu/m thick dielectric layer have passed 2000 cycles with zero failures. Cross-sectioning confirmed that failures were caused by process related defects, such as thin electrolytic copper plating. This paper will discuss the reliability results of the PRC HDI microvias process and methods to improve the mechanical reliability of small photo defined microvias fabricated on similar laminate substrates.
Phase diagram of two-color lattice QCD in the chiral limit

We study thermodynamics of strongly coupled lattice QCD with two colors of massless staggered fermions as a function of the baryon chemical potential $\ensuremath{\mu}$ in $3+1$ dimensions using a new cluster algorithm. We find evidence that the model undergoes a weak first order phase transition at $\ensuremath{\mu}=0$ which becomes second order at a finite $\ensuremath{\mu}$. Symmetry considerations suggest that the universality class of these phase transitions should be governed by a $O(N)\ifmmode\times\else\texttimes\fi{}O(2)$ field theory with collinear order, with $N=3$ at $\ensuremath{\mu}=0$ and $N=2$ at $\ensuremath{\mu}\ensuremath{\ne}0$. The universality class of the second order phase transition at $\ensuremath{\mu}\ensuremath{\ne}0$ appears to be governed by the decoupled $XY$ fixed point present in the $O(2)\ifmmode\times\else\texttimes\fi{}O(2)$ field theory. Finally we show that the quantum ($T=0$) phase transition as a function of $\ensuremath{\mu}$ is a second order mean field transition.
Heegaard Genus Formula for Haken Manifolds

Suppose M is a compact orientable 3-manifold and \(Q \subset M\) a properly embedded orientable boundary incompressible essential surface. Denote the completions of the components of M – Q with respect to the path metric by M1, ...,Mk. Denote the smallest possible genus of a Heegaard splitting of M, or Mj respectively, for which ∂M, or ∂Mj respectively, is contained in one compression body by g(M, ∂M), or g(Mj, ∂Mj) respectively. Denote the maximal number of non-parallel essential annuli that can be simultaneously embedded in Mj by nj. Then $$g(M, \partial M) \geqslant \frac{1}{5}\left(\sum\limits_{j} g(M^{j}, \partial M^{j}) - |M - Q| + 5 - 2 \chi(\partial - V ) + 4 \chi(Q) - 4 \sum\limits_{j} n_j\right) $$
Glassy dynamics of crystallite formation: The role of covalent bonds

We examine nonequilibrium features of collapse behavior in model polymers with competing crystallization and glass transitions using extensive molecular dynamics simulations. By comparing to “colloidal” systems with no covalent bonds but the same non-bonded interactions, we find three principal results: (i) Tangent-sphere polymers and colloids, in the equilibrium-crystallite phase, have nearly identical static properties when the temperature T is scaled by the crystallization temperature Tcryst; (ii) Qualitative features of nonequilibrium relaxation below Tcryst, measured by the evolution of local structural properties (such as the number of contacts) toward equilibrium crystallites, are the same for polymers and colloids; and (iii) Significant quantitative differences in rearrangements in polymeric and colloidal crystallites, in both far-from equilibrium and near-equilibrium systems, can be understood in terms of chain connectivity. These results have important implications for understanding slow relaxation processes in collapsed polymers, partially folded, misfolded, and intrinsically disordered proteins.
Program Responses to Acute and Chronic Malnutrition: Divergences and Convergences

Program approaches for addressing acute malnutrition and those for addressing chronic malnutrition have grown in different directions. Their specialization has led to productive advances in the efficacy of specific interventions but has also created divergences in implementation. Greater convergence and integration between the 2 sets of approaches would help programs respond to the diversity of conditions faced in the field and enable a more comprehensive continuum of care from prevention to treatment. After reviewing the causes of the differences in approach, this paper examines programmatic and scientific challenges to greater convergence and suggests steps to promote effective integration of acute and chronic malnutrition services. Steps include strengthening community linkages between program platforms, assessing the degree and type of integration needed in various situations, identifying cost efficiencies, and developing joint tools where possible.
Diagnosing breast cancer using diffuse reflectance spectroscopy and intrinsic fluorescence spectroscopy

Using diffuse reflectance spectroscopy and intrinsic fluorescence spectroscopy, we have developed an algorithm that successfully classifies normal breast tissue, fibrocystic change, fibroadenoma, and infiltrating ductal carcinoma in terms of physically meaningful parameters. We acquire 202 spectra from 104 sites in freshly excised breast biopsies from 17 patients within 30 min of surgical excision. The broadband diffuse reflectance and fluorescence spectra are collected via a portable clinical spectrometer and specially designed optical fiber probe. The diffuse reflectance spectra are fit using modified diffusion theory to extract absorption and scattering tissue parameters. Intrinsic fluorescence spectra are extracted from the combined fluorescence and diffuse reflectance spectra and analyzed using multivariate curve resolution. Spectroscopy results are compared to pathology diagnoses, and diagnostic algorithms are developed based on parameters obtained via logistic regression with cross-validation. The sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy (total efficiency) of the algorithm are 100, 96, 69, 100, and 91%, respectively. All invasive breast cancer specimens are correctly diagnosed. The combination of diffuse reflectance spectroscopy and intrinsic fluorescence spectroscopy yields promising results for discrimination of breast cancer from benign breast lesions and warrants a prospective clinical study.
Thermal transport properties of gold-covered thin-film silicon dioxide

Due to continued miniaturization, the performance and reliability of electronic devices composed of multiple thin layers of material are highly dependent on effective thermal management. Since the thermal properties of thin films, such as SiO/sub 2/, can vary considerably from bulk values, the determination of those properties (as well as the interface resistance between SiO/sub 2/ and adjacent layers) is critical for the purposes of design. In this work, a transient thermo-reflectance system has been employed to measure the thermal characteristics of thin-film SiO/sub 2/ layers. Results show that for layers of SiO/sub 2/ in the range of 100-1000 /spl Aring/, the intrinsic thermal conductivity (TC) is independent of thickness and smaller than the traditionally reported value of bulk silicon dioxide (1.4 W/m-K). The intrinsic value was measured to be around 90% (1.27 W/m-k) and 75% (1.05 W/m-k) of the latter bulk value for thermally grown (TG) and ion beam sputtered (IBS) oxides, respectively. The thermal interface resistances of TG and IBS SiO/sub 2/ films were measured at 1.68 /spl times/ 10/sup -8/ m/sup 2/-K/W and 2.58 /spl times/ 10/sup -8/ m/sup 2/-K/W, respectively. If a chromium film of around 100 /spl Aring/ is deposited between the gold and SiO/sub 2/ layers, the interface thermal resistance improves to 0.78 /spl times/ 10/sup -8/ m/sup 2/-K/W for TG films and 1.15 /spl times/ 10/sup -8/ m/sup 2/-K/W for IBS films. Thus, the effective thermal resistance of SiO/sub 2/ thin-films (i.e., with interface effects) is up to one order of magnitude smaller than the values reported for bulk SiO/sub 2/.
Complexity, parallel computation and statistical physics

The intuition that a long history is required for the emergence of complexity in natural systems is formalized using the notion of depth. The depth of a system is defined in terms of the number of parallel computational steps needed to simulate it. Depth provides an objective, irreducible measure of history that is applicable to systems of the kind studied in statistical physics. It is argued that physical complexity cannot occur in the absence of substantial depth and that depth is a useful proxy for physical complexity. The ideas are illustrated for a variety of systems in statistical physics. © 2006 Wiley Periodicals, Inc. Complexity 11: 46–64, 2006
Open at the top; open at the bottom; and continually (but slowly) evolving

Systems of systems differ from traditional systems in that they are open at the top, open at the bottom, and continually (but slowly) evolving. "Open at the top" means that there is no pre-defined top level application. New applications may be created at any time. "Open at the bottom" means that the system primitives are defined functionally rather than concretely. This allows the implementation of these primitives to be modified as technology changes. "Continually (but slowly) evolving" means that the system's functionality is stable enough to be useful but is understood to be subject to modification. Systems with these properties tend to be environments within which other systems operate - and hence are systems of systems. It is also important to understand the larger environment within which a system of systems exists.
Reference-based compression of short-read sequences using path encoding

Motivation: Storing, transmitting and archiving data produced by next-generation sequencing is a significant computational burden. New compression techniques tailored to short-read sequence data are needed. Results: We present here an approach to compression that reduces the difficulty of managing large-scale sequencing data. Our novel approach sits between pure reference-based compression and reference-free compression and combines much of the benefit of reference-based approaches with the flexibility of de novo encoding. Our method, called path encoding, draws a connection between storing paths in de Bruijn graphs and context-dependent arithmetic coding. Supporting this method is a system to compactly store sets of kmers that is of independent interest. We are able to encode RNA-seq reads using 3–11% of the space of the sequence in raw FASTA files, which is on average more than 34% smaller than competing approaches. We also show that even if the reference is very poorly matched to the reads that are being encoded, good compression can still be achieved. Availability and implementation: Source code and binaries freely available for download at http://www.cs.cmu.edu/~ckingsf/software/pathenc/, implemented in Go and supported on Linux and Mac OS X. Contact: ude.umc.sc@klrac. Supplementary information: Supplementary data are available at Bioinformatics online.
Collision Avoidance for Satellites in Formation Flight

Satellites in a formation might need to maneuver to avoid potential collisions that may occur when foreign objects enter the formation, or when a satellite within the formation drifts into the path of another. In either case we seek to determine the probability of a future collision based on current state knowledge and the uncertain dynamic environment, and further to determine a control strategy to reduce the collision probability to an acceptable level while minimizing the ΔV required for the maneuver. The approach taken in this paper is to propagate the uncertainty covariance using linear theory and determine the probability that the relative displacement between two objects is less than some “collision metric.” This probability will be a function of the initial conditions, the uncertainty in the initial state and disturbing acceleration, and the time-to-go before closest approach. The intent of the paper is to examine the evolution of this probability and to determine an effective maneuver algorithm that can minimize the probability of collision while reducing the energy expenditure in the maneuver. Numerical values are used for satellites in a tightly spaced, low-Earth-orbit formation. For satellites in a close formation, it is demonstrated that the uncertain disturbance environment can make efficient ΔV maneuvers difficult to determine, as collision probabilities can vary rapidly (on the orbital timescale.) Remarks and some sample calculations on the total ΔV required for an evasion maneuver are presented.
Highly Stereoselective α-Hydroxyalkylation/Chlorination of α,β-Acetylenic Ketones—An Efficient Approach to β-Halogeno Baylis–Hillman Adducts

Abstract A highly stereoselective method for the synthesis of (E)-β-halogeno Baylis–Hillman adducts has been developed. The new method involves a tandem α-hydroxyalkylation/β-chlorination of α,β-acetylenic ketones by using TiCl4 as the chlorine source for α,β-conjugate addition, and concurrently as the Lewis acid promoter for the carbonyl addition. The new system tolerates a broad scope of reactants in which aliphatic and aromatic α-acetylenic ketones can be subjected to the conjugate addition. Both aliphatic and aromatic aldehydes can also be employed as electrophilic acceptors. Good yields (61–88%) and high E/Z stereoselectivity have been obtained for the nine examples which were examined, only in one case was E/Z selectivity of 17/1 observed and the two individual isomers are separable via flash column chromatography.
Adaptive evolution of color vision as seen through the eyes of butterflies

Butterflies and primates are interesting for comparative color vision studies, because both have evolved middle- (M) and long-wavelength- (L) sensitive photopigments with overlapping absorbance spectrum maxima (λmax values). Although positive selection is important for the maintenance of spectral variation within the primate pigments, it remains an open question whether it contributes similarly to the diversification of butterfly pigments. To examine this issue, we performed epimicrospectrophotometry on the eyes of five Limenitis butterfly species and found a 31-nm range of variation in the λmax values of the L-sensitive photopigments (514–545 nm). We cloned partial Limenitis L opsin gene sequences and found a significant excess of replacement substitutions relative to polymorphisms among species. Mapping of these L photopigment λmax values onto a phylogeny revealed two instances within Lepidoptera of convergently evolved L photopigment lineages whose λmax values were blue-shifted. A codon-based maximum-likelihood analysis indicated that, associated with the two blue spectral shifts, four amino acid sites (Ile17Met, Ala64Ser, Asn70Ser, and Ser137Ala) have evolved substitutions in parallel and exhibit significant dN/dS >1. Homology modeling of the full-length Limenitis arthemis astyanax L opsin placed all four substitutions within the chromophore-binding pocket. Strikingly, the Ser137Ala substitution is in the same position as a site that in primates is responsible for a 5- to 7-nm blue spectral shift. Our data show that some of the same amino acid sites are under positive selection in the photopigments of both butterflies and primates, spanning an evolutionary distance >500 million years.
Tip position control of a flexible one arm robot with predictive adaptive output feedback implemented with lattice filter parameter identifier

A lattice-filter structure is used for real-time parameter estimation of a flexible one-arm robot. The estimated parameters are employed in the control calculations based on predictive adaptive output feedback control. The lattice filters are particularly suitable for identifying the parameters of mechanical systems with distributed flexibility, since the order of the filter may be adjusted online as the task conditions require. Hence, the required dynamic model order for an accurate control does not have to be decided upon beforehand. A predictive adaptive control is studied using tip-position measurements. Although there are potential instability problems due to the nonminimum-phase nature of the open-loop system as a result of sensor-actuator noncolocation, the discrete-time predictive adaptive control implemented with the lattice filter (forming a special self-tuning regulator) demonstrated precision, high-bandwidth tip-position control of a flexible one-arm robot. >
Modeling Autonomous Catalog for Electronic Commerce

The catalog function is an essential feature in B2C and B2B e-commerce. While catalog is primarily for end users to navigate and search for interested products, other e-commerce functions such as merchandising, order, inventory and aftermarket constantly refer to information stored in the catalog [1]. The billion-dollar mail order business was created around catalog long before e-commerce. More opportunities surface after catalog content previously created on paper is digitized. While catalog is recognized as a necessity for a successful web store, its content structure varies greatly across industries and also within each industry. Product categories, attributes, measurements, languages, and currency all contribute to the wide variations, which create a difficult dilemma for catalog designers.
Applying the Risk-Needs-Responsivity (RNR) Model to Juvenile Justice:

Application of the Risk-Needs-Responsivity (RNR) model in adult correctional research and practice is well developed, but remains underway in the juvenile justice system. The RNR model may facilita...
Multiple point competition

Situations where firms compete against each other simultaneously in several markets abound in real life. However, there is very little conceptual or theoretical literature on multiple point competition. This paper offers a first attempt at developing a conceptual framework for analysing and understanding situations involving multiple point competition. Several examples are discussed to provide insights into the options available to the competitors and the equilibrium outcomes of such competition.
Improving automatic speech recognition through head pose driven visual grounding

In this paper, we present a multimodal speech recognition system for real world scene description tasks. Given a visual scene, the system dynamically biases its language model based on the content of the visual scene and visual attention of the speaker. Visual attention is used to focus on likely objects within the scene. Given a spoken description the system then uses the visually biased language model to process the speech. The system uses head pose as a proxy for the visual attention of the speaker. Readily available standard computer vision algorithms are used to recognize the objects in the scene and automatic real time head pose estimation is done using depth data captured via a Microsoft Kinect. The system was evaluated on multiple participants. Overall, incorporating visual information into the speech recognizer greatly improved speech recognition accuracy. The rapidly decreasing cost of 3D sensing technologies such as the Kinect allows systems with similar underlying principles to be used for many speech recognition tasks where there is visual information.
A critique of traditional agricultural credit projects and policies

Abstract Authors critique the results, assumptions, and policies commonly associated with agricultural credit projects in low income countries. A summary of new views on these projects is present. These views emphasize voluntary savings mobilization and positive real rates of interest. Several explanations are given for why few of these new views have been adopted by policymakers.
Adaptive control in the presence of input constraints

This paper deals with the problem of adaptively controlling a linear time-invariant plant in the presence of constraints on the input amplitude. We introduce a new adaptive algorithm which ensures that the plant can be locally stabilized. In addition to the standard assumptions which are required for adaptive control in the ideal case, an upper bound on the plant control parameter is required to be known. The results are evaluated by simulation studies. >
Integration of instance-based learning and text mining for identification of potential virus/bacterium as bio-terrorism weapons

There are some viruses and bacteria that have been identified as bioterrorism weapons. However, there are a lot other viruses and bacteria that can be potential bioterrorism weapons. A system that can automatically suggest potential bioterrorism weapons will help laypeople to discover these suspicious viruses and bacteria. In this paper we apply instance-based learning & text mining approach to identify candidate viruses and bacteria as potential bio-terrorism weapons from biomedical literature. We first take text mining approach to identify topical terms of existed viruses (bacteria) from PubMed separately. Then, we use the term lists as instances to build matrices with the remaining viruses (bacteria) to discover how much the term lists describe the remaining viruses (bacteria). Next, we build a algorithm to rank all remaining viruses (bacteria). We suspect that the higher the ranking of the virus (bacterium) is, the more suspicious they will be potential bio-terrorism weapon. Our findings are intended as a guide to the virus and bacterium literature to support further studies that might then lead to appropriate defense and public health measures.
Graphical Models of Residue Coupling in Protein Families

Many statistical measures and algorithmic techniques have been proposed for studying residue coupling in protein families. Generally speaking, two residue positions are considered coupled if, in the sequence record, some of their amino acid type combinations are significantly more common than others. While the proposed approaches have proven useful in finding and describing coupling, a significant missing component is a formal probabilistic model that explicates and compactly represents the coupling, integrates information about sequence, structure, and function, and supports inferential procedures for analysis, diagnosis, and prediction. We present an approach to learning and using probabilistic graphical models of residue coupling (GMRCs). These models capture significant conservation and coupling constraints observable in a multiply aligned set of sequences. Our approach can place a structural prior on considered couplings, so that all identified relationships have direct mechanistic explanations. It can also incorporate information about functional classes, and thereby learn a differential graphical model that distinguishes constraints common to all classes from those unique to individual classes. Such differential models separately account for class-specific conservation and family- wide coupling, two different sources of sequence covariation. They are then able to perform interpretable functional classification of new sequences, explaining classification decisions in terms of the underlying conservation and coupling constraints. We apply our approach in studying both G protein-coupled receptors and PDZ domains, identifying and analyzing family-wide and class-specific constraints, and performing functional classification. The results demonstrate that GMRCs provide a powerful tool for uncovering, representing, and utilizing significant sequence-structure-function relationships in protein families.