cssi/SciSciGPT-SciSciNet huggingface dataset:
Dark energy and the hierarchy problem

The well-known hierarchy between the Planck scale (>> 1019GeV) and the TeV scale, namely a ratio of {approx} 10{sup 16} between the two, is coincidentally repeated in a inverted order between the TeV scale and the dark energy scale at {approx} 10{sup -3} eV implied by the observations. We argue that this is not a numerical coincidence. The same brane-world setups to address the first hierarchy problem may also in principle address this second hierarchy issue. Specifically, we consider supersymmetry in the bulk and its breaking on the brane and resort to the Casimir energy induced by the bulk graviton-gravitino mass-shift on the brane as the dark energy. For the ADD model we found that our notion is sensible only if the number of extra dimension n = 2. We extend our study to the Randall-Sundrum model. Invoking the chirality-flip on the boundaries for SUSY-breaking, the zero-mode gravitino contribution to the Casimir energy does give rise to the double hierarchy. Unfortunately since the higher Kaluza-Klein modes acquire relative mass-shifts at the TeV level, the zero-mode contribution to Casimir energy is overshadowed.
Tomographic Reconstruction Of Axially Symmetric Objects From A Single Radiograph

In 1826 Abel presented the method of obtaining the profile of a circularly symmetric 2-D object from its projection. It is shown that the extension of Abel inversion, the reconstruction of a 3-D axially symmetric object from a single radiograph, offers significant benefits as an image analysis tool. These benefits include improved delineation of material boundaries, enhanced. display of minor deviations from axial symmetry, as produced by defects, and accurate estimation of the linear attenuation coefficients of the materials. Frequently this technique allows observation of features in the object that are too subtle to be seen in the original radiograph.
Composition Dependence of Elastic Moduli in Na2O‐TiO2‐SiO2 Glasses

Measurements of the elastic moduli for Na2O-TiO2-SiO2, glasses located in 2 adjacent primary phase fields are quantitatively represented by equations in terms of linear mole fractions. Evaluation of the data showed that these linear relations are unique for each group of glasses studied.
Regularity and normality of the secant variety to a projective curve

Abstract For a smooth curve of genus g embedded by a line bundle of degree at least 2 g + 3 we show that the ideal sheaf of the secant variety is 5-regular. This bound is sharp with respect to both the degree of the embedding and the bound on the regularity. Further, we show that the secant variety is projectively normal for the generic embedding of degree at least 2 g + 3 .
Image Compression Using Block Truncation Coding

A new technique for image compression called Block Truncation Coding (BTC) is presented and compared with transform and other techniques. The BTC algorithm uses a two-level (one-bit) nonparametric quantizer that adapts to local properties of the image. The quantizer that shows great promise is one which preserves the local sample moments. This quantizer produces good quality images that appear to be enhanced at data rates of 1.5 bits/picture element. No large data storage is required, and the computation is small. The quantizer is compared with standard (minimum mean-square error and mean absolute error) one-bit quantizers. Modifications of the basic BTC algorithm are discussed along with the performance of BTC in the presence of channel errors.
A General Class of Throughput Optimal Routing Policies in Multi-Hop Wireless Networks

This paper considers the problem of throughput optimal routing/scheduling in a multi-hop constrained queueing network with random connectivity whose special cases include opportunistic multi-hop wireless networks and input-queued switch fabrics. The main challenge in the design of throughput optimal routing policies is closely related to identifying appropriate and universal Lyapunov functions with negative expected drift. The few well-known throughput optimal policies in the literature are constructed using simple quadratic or exponential Lyapunov functions of the queue backlogs and as such they seek to balance the queue backlogs across network independent of the topology. By considering a class of continuous, differentiable, and piece-wise quadratic Lyapunov functions, this paper provides a large class of throughput optimal routing policies. The proposed class of Lyapunov functions allow for the routing policy to control the traffic along short paths for a large portion of state-space while ensuring a negative expected drift. This structure enables the design of a large class of routing policies. In particular, and in addition to recovering the throughput optimality of the well-known backpressure routing policy, an opportunistic routing policy with congestion diversity is proved to be throughput optimal.
In-Home Virtual Reality Videogame Telerehabilitation in Adolescents With Hemiplegic Cerebral Palsy

Abstract Golomb MR, McDonald BC, Warden SJ, Yonkman J, Saykin AJ, Shirley B, Huber M, Rabin B, AbdelBaky M, Nwosu ME, Barkat-Masih M, Burdea GC. In-home virtual reality videogame telerehabilitation in adolescents with hemiplegic cerebral palsy. Objective To investigate whether in-home remotely monitored virtual reality videogame-based telerehabilitation in adolescents with hemiplegic cerebral palsy can improve hand function and forearm bone health, and demonstrate alterations in motor circuitry activation. Design A 3-month proof-of-concept pilot study. Setting Virtual reality videogame-based rehabilitation systems were installed in the homes of 3 participants and networked via secure Internet connections to the collaborating engineering school and children's hospital. Participants Adolescents (N=3) with severe hemiplegic cerebral palsy. Intervention Participants were asked to exercise the plegic hand 30 minutes a day, 5 days a week using a sensor glove fitted to the plegic hand and attached to a remotely monitored videogame console installed in their home. Games were custom developed, focused on finger movement, and included a screen avatar of the hand. Main Outcome Measures Standardized occupational therapy assessments, remote assessment of finger range of motion (ROM) based on sensor glove readings, assessment of plegic forearm bone health with dual-energy x-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT), and functional magnetic resonance imaging (fMRI) of hand grip task. Results All 3 adolescents showed improved function of the plegic hand on occupational therapy testing, including increased ability to lift objects, and improved finger ROM based on remote measurements. The 2 adolescents who were most compliant showed improvements in radial bone mineral content and area in the plegic arm. For all 3 adolescents, fMRI during grip task contrasting the plegic and nonplegic hand showed expanded spatial extent of activation at posttreatment relative to baseline in brain motor circuitry (eg, primary motor cortex and cerebellum). Conclusions Use of remotely monitored virtual reality videogame telerehabilitation appears to produce improved hand function and forearm bone health (as measured by DXA and pQCT) in adolescents with chronic disability who practice regularly. Improved hand function appears to be reflected in functional brain changes.
The effect of patient and semen characteristics on live birth rates following intrauterine insemination: a retrospective study.

Results: Among 1728 cycles, 116 (6.7%) resulted in live deliveries. Among the 38 patient and semen variables analyzed, only 3 were associated with successful IUI outcome: female age <37.7 years at the time of treatment (P = 0.02); the absence of any corrective pelvic surgery (P < 0.001); and postwash sperm motility (P = 0.006). Couples with none of these three risk factors achieved per-cycle pregnancy rates of 12.4%. Women with two risk factors (age and pelvic surgery) achieved per-cycle pregnancy rates of 4.6% when sperm had good postwash motility. No pregnancies were achieved when low postwash motility was combined with any other risk factor. Conclusions: Advanced female age, poor postwash sperm motility, and a history of corrective pelvic surgery are significant risk factors for poor IUI success rates. Poor postwash sperm motility in combination with either of these other two risk factors resulted in no successful pregnancies.
The algebra of discrete torsion

Abstract We analyze the algebraic structures of G-Frobenius algebras which are the algebras associated to global group quotient objects a.k.a. global orbifolds. Here G is any finite group. First, we show that these algebras are modules over the Drinfel'd double of the group ring k [ G ] and are moreover k [ G ] -module algebras and k [ G ] -comodule algebras. We furthermore consider G-Frobenius algebras up to projective equivalence and define universal shifts of the multiplication and the G-action preserving the projective equivalence class. We show that these shifts are parameterized by Z 2 ( G , k * ) and by H 2 ( G , k * ) when considering of G-Frobenius algebras up to isomorphism. We go on to show that these shifts can be realized by the forming of tensor products with twisted group rings, thus providing a group action of Z 2 ( G , k * ) on G-Frobenius algebras acting transitively on the classes G-Frobenius related by universal shifts. The multiplication is changed according to the cocycle, while the G-action transforms with a different cocycle derived from the cocycle defining the multiplication. The values of this second cocycle also appear as a factor in front of the trace which is considered in the trace axiom of G-Frobenius algebras. This allows us to identify the effect of our action by Z 2 ( G , k * ) as so-called discrete torsion, effectively unifying all known approaches to discrete torsion for global orbifolds in one algebraic theory. The new group action of discrete torsion is essentially derived from the multiplicative structure of G-Frobenius algebras. This yields an algebraic realization of discrete torsion defined via the perturbation of the multiplication resulting from a tensor product with a twisted group ring. Additionally we show that this algebraic formulation of discrete torsion allows for a treatment of G-Frobenius algebras analogous to the theory of projective representations of groups, group extensions and twisted group ring modules. Lastly, we identify another set of discrete universal transformations among G-Frobenius algebras pertaining to their super-structure and classified by Hom ( G , Z / 2 Z ) which are essential for the application to mirror symmetry for singularities with symmetries.
On the Tradeoffs of Implementing Randomized Network Coding in Multicast Networks

Randomized network coding (RNC) has greatly reduced complexity of implementing network coding in large-scale, heterogeneous networks. Two tradeoffs are studied here that further reduce the overhead in applying RNC. The first examines how RNC performance varies with a node's randomizing capabilities. Specifically, a limited randomized network coding (L-RNC) scheme - in which intermediate nodes perform randomized encoding based on only limited number of random coefficients - is proposed and its performance bounds are analyzed. L-RNC is applicable to networks in which nodes have either limited computation/storage capacity or have ambiguity about downstream edge connectivity (e.g., as in ad hoc sensor networks). A second tradeoff studied here examines the relationship between reliability and capacity gains of RNC, i.e., how the outage probability of RNC relates to the transmission rate at source node. This tradeoff reveals that significant reductions in outage probability are possible when the source deliberately transmit at (only slightly) below network capacity. It therefore provides an effective alternative to improve RNC feasibility when the size of finite field is fixed.
TESTING A PREDICTIVE THEORETICAL MODEL FOR THE MASS LOSS RATES OF COOL STARS

The basic mechanisms responsible for producing winds from cool, late-type stars are still largely unknown. We take inspiration from recent progress in understanding solar wind acceleration to develop a physically motivated model of the time-steady mass loss rates of cool main-sequence stars and evolved giants. This model follows the energy flux of magnetohydrodynamic turbulence from a subsurface convection zone to its eventual dissipation and escape through open magnetic flux tubes. We show how Alfven waves and turbulence can produce winds in either a hot corona or a cool extended chromosphere, and we specify the conditions that determine whether or not coronal heating occurs. These models do not utilize arbitrary normalization factors, but instead predict the mass loss rate directly from a star's fundamental properties. We take account of stellar magnetic activity by extending standard age-activity-rotation indicators to include the evolution of the filling factor of strong photospheric magnetic fields. We compared the predicted mass loss rates with observed values for 47 stars and found significantly better agreement than was obtained from the popular scaling laws of Reimers, Schroder, and Cuntz. The algorithm used to compute cool-star mass loss rates is provided as a self-contained and efficient computer code. We anticipate that the results from this kind of model can be incorporated straightforwardly into stellar evolution calculations and population synthesis techniques.
Bayesian decision feedback for segmentation of binary images

We present real-time algorithms for the segmentation of binary images modeled by Markov mesh random fields (MMRFs) and corrupted by independent noise. The goal is to find a recursive algorithm to compute the maximum a posteriori (MAP) estimate of each pixel of the scene using a fixed lookahead of D rows and D columns of the observations. First, this MAP fixed-lag estimation problem is set up and the corresponding optimal recursive (but computationally complex) estimator is derived. Then, both hard and soft (conditional) decision feedbacks are introduced at appropriate stages of the optimal estimator to reduce the complexity. The algorithm is applied to several synthetic and real images. The results demonstrate the viability of the algorithm both complexity-wise and performance-wise, and show its subjective relevance to the image segmentation problem.
Perivascular Adipose Tissue and Coronary Vascular Disease

Coronary perivascular adipose tissue is a naturally occurring adipose tissue depot that normally surrounds the major coronary arteries on the surface of the heart. Although originally thought to promote vascular health and integrity, there is a growing body of evidence to support that coronary perivascular adipose tissue displays a distinct phenotype relative to other adipose depots and is capable of producing local factors with the potential to augment coronary vascular tone, inflammation, and the initiation and progression of coronary artery disease. The purpose of the present review is to outline previous findings about the cardiovascular effects of coronary perivascular adipose tissue and the potential mechanisms by which adipose-derived factors may influence coronary vascular function and the progression of atherogenesis.
Interfacial reaction kinetics

We study irreversible A{B reaction kinetics at a xed interface separating two immiscible bulk phases, A and B. Coupled equations are derived for the hierarchy of many-body correlation functions. Postulating physically motivated bounds, closed equations result without the need for ad hoc decoupling approximations. We consider general dynamical exponent z ,w herext t 1=z is the rms diusion distance after time t. At short times the number of reactions per unit area, Rt ,i s2nd order in the far-eld reactant densities n 1 ;n 1 . For spatial dimensions d above a critical value dc = z 1, simple mean eld (MF) kinetics pertain, Rt Qbtn 1 n 1 where Qb is the local reactivity. For low dimensions d Q b (n 1 ) (z (d+1))=d . Logarithmic corrections arise in marginal cases. At long times, a cross-over to 1st order DC kinetics occurs:Rt xtn 1 . A density depletion hole grows on the more dilute A side. In the symmetric case (n 1 = n 1 ), when d d c fluctuations are unimportant: local mean eld theory applies at the interface (joint density distribution approximating the product of A and B densities) and n s t (1 z)=(2z) . We apply our results to simple molecules (Fickian diusion, z = 2) and to several
Reliable VLSI sequential controllers

A VLSI architecture for synchronous sequential controllers is resented that has attractive qualities for roducing reliable circuits. In these circuits, one hardware implementation can realize any flow table with a maximum of 2n internal states and m inputs. A real time fault detection means is resented along with a strategy for verifying the correctness of the checking hardware. This self-check feature can be employed with no increase in hardware. The architecture can be modified to achieve fail-safe designs. With no increase in hardware, an adaptable circuit can be realized that allows replacement of faulty transitions with fault-free transitions
DYNAMIC PORTFOLIO OPTIMIZATION WITH A DEFAULTABLE SECURITY AND REGIME‐SWITCHING

We consider a portfolio optimization problem in a defaultable market with finitely-many economical regimes, where the investor can dynamically allocate her wealth among a defaultable bond, a stock, and a money market account. The market coefficients are assumed to depend on the market regime in place, which is modeled by a finite state continuous time Markov process. By separating the utility maximization problem into a predefault and postdefault component, we deduce two coupled Hamilton–Jacobi–Bellman equations for the post- and predefault optimal value functions, and show a novel verification theorem for their solutions. We obtain explicit constructions of value functions and investment strategies for investors with logarithmic and Constant Relative Risk Aversion utilities, and provide a precise characterization of the directionality of the bond investment strategies in terms of corporate returns, forward rates, and expected recovery at default. We illustrate the dependence of the optimal strategies on time, losses given default, and risk aversion level of the investor through a detailed economic and numerical analysis.
Environmental and Distributional Impacts of Conservation Targeting Strategies

Abstract Resource purchasing funds have become a major tool for environmental protection and resource conservation. These funds use various strategies to target resources for conservation, the choice of which may lead to striking differences in environmental performance. This paper develops an analytical framework to analyze the impact of alternative targeting strategies on different interest groups, including consumers, producers, labor, and environmentalists. We show that ignoring the output price effect of purchasing funds reduces environmental gain and in some cases may make a purchasing fund counterproductive, and we argue that the optimal design of targeting criteria must consider the price feedback effect.
Double-resonance spectroscopy in gas lasers

The general theory of double resonance in gas lasers is used to deduce analytic expressions for the intensity of a laser oscillating on a J = 1 to J = 0 atomic transition, and experimental data on the 1.52-\mu (2s_{2} - 2p_{1}) transition in the He-Ne laser are reported. Phenomenological modification of the theory is introduced to account for the pronounced effect of collision broadening upon double resonance. Atomic parameters of the 2s_{2} level of neon are obtained by comparison between theory and experiment. The collision-dependent decay rates introduced in the theory are also obtained, and the functional dependence of the theory upon the decay rates is examined.
Keck Speckle Imaging of the White Dwarf G29-38: No Brown Dwarf Companion Detected

The white dwarf Giclas 29-38 has attracted much attention on account of its large infrared excess and the suggestion that excess might be due to a companion brown dwarf. We observed this object using speckle interferometry at the Keck telescope, obtaining diffraction-limited resolution (55 mas) at the K band, and found it unresolved. Assuming that the entire K-band excess is attributable to a single pointlike companion, we place an upper limit on the binary separation of 30 mas, or 0.42 AU at the star's distance of 14.1 pc. This result, combined with astroseismological data and other images of G29-38, supports the hypothesis that the source of the near-infrared excess is not a cool companion but a dust cloud.
Chiral action at a distance: remote substituent effects on the optical activity of calyculins A and B.

Calyculins A and B differ only by the (E)- vs (Z)-configuration at C(2). Yet, they show a large difference in optical rotations. We demonstrate a new strategy that provides a physical analysis of this long-range chiro-optical effect by Boltzmann-averaged atomic contribution mapping. The polarizability characteristics of the CN substituent rather than the perturbation of the stereogenic centers or the introduction of dissymmetry into the polyene chain give rise to the remarkable difference in rotation angles.
App stores for the brain: privacy & security in brain-computer interfaces

An increasing number of Brain-Computer Interfaces (BCIs) are being developed in medical and nonmedical fields, including marketing, gaming and entertainment industries. BCI-enabled technology carries a great potential to improve and enhance the quality of human lives. It provides people suffering from severe neuromuscular disorders with a way to interact with the external environment. It also enables a more personalized user experience in gaming and entertainment. These BCI applications are, however, not without risk. Established engineering practices set guarantees on performance, reliability and physical safety of BCIs. But no guarantees or standards are currently in place regarding user privacy and security. In this paper, we identify privacy and security issues arising from possible misuse or inappropriate use of BCIs. In particular, we explore how current and emerging non-invasive BCI platforms can be used to extract private information, and we suggest an interdisciplinary approach to mitigating this problem. We then propose a tool to prevent this side-channel extraction of users' private information. This is a first step towards making BCI-enabled technologies secure and privacy preserving.
The Efficiency of Slacking Off: Evidence from the Emergency Department

Work schedules play an important role in utilizing labor in organizations. In this study of emergency department physicians in shift work, schedules induce two distortions: First, physicians â€œslack offâ€ by accepting fewer patients near end of shift (EOS). Second, physicians distort patient care, incurring higher costs as they spend less time on patients assigned near EOS. Examining how these effects change with shift overlap reveals a tradeoff between the two. Within an hour after the normal time of work completion, physicians are willing to spend hospital resources more than six times their market wage to preserve their leisure. Accounting for overall costs, I find that physicians slack off at approximately secondâ€ best optimal levels.
Wide area traffic: the failure of Poisson modeling

Network arrivals are often modeled as Poisson processes for analytic simplicity, even though a number of traffic studies have shown that packet interarrivals are not exponentially distributed. We evaluate 24 wide area traces, investigating a number of wide area TCP arrival processes (session and connection arrivals, FTP data connection arrivals within FTP sessions, and TELNET packet arrivals) to determine the error introduced by modeling them using Poisson processes. We find that user-initiated TCP session arrivals, such as remote-login and file-transfer, are well-modeled as Poisson processes with fixed hourly rates, but that other connection arrivals deviate considerably from Poisson; that modeling TELNET packet interarrivals as exponential grievously underestimates the burstiness of TELNET traffic, but using the empirical Tcplib interarrivals preserves burstiness over many time scales; and that FTP data connection arrivals within FTP sessions come bunched into "connection bursts", the largest of which are so large that they completely dominate FTP data traffic. Finally, we offer some results regarding how our findings relate to the possible self-similarity of wide area traffic. >
Catalytic dehydration of C6 carbohydrates for the production of hydroxymethylfurfural (HMF) as a versatile platform chemical

Interest in utilizing biorenewable feedstocks to produce fuels and chemicals has risen greatly in the past decade due to the economic, political and environmental concerns associated with diminishing petroleum reserves. A fundamental challenge lying ahead in the development of efficient processes to utilize biomass feedstock is that, unlike their petroleum counterparts, biomass contains an excess amount of oxygen. Therefore, catalytic strategies such as dehydration and hydrogenolysis amongst others have been extensively studied as platform technologies for deoxygenation. In this review, we primarily discuss the catalytic dehydration of C6 carbohydrates to 5-hydroxymethylfurfural, which has attracted much attention due to the versatility of using furanic compounds as an important platform intermediate to synthesize various chemicals. The emphasis is on the fundamental mechanistic chemistry so as to provide insights for further catalyst/catalytic system design. After separately discussing fructose and glucose dehydration, this review summarizes recent progress with bi-functional catalyst systems for tandem glucose/fructose isomerization and subsequent fructose dehydration, thereby realizing highly selective HMF production directly from the more abundant and cheaper C6 sugar feedstock, glucose.
Generating all subsets of a finite set with disjoint unions

If X is an n-element set, we call a family G@?PX a k-generator for X if every x@?X can be expressed as a union of at most k disjoint sets in G. Frein, Leveque and Sebo conjectured that for n>2k, the smallest k-generators for X are obtained by taking a partition of X into classes of sizes as equal as possible, and taking the union of the power-sets of the classes. We prove this conjecture for all sufficiently large n when k=2, and for n a sufficiently large multiple of k when k>=3.
Robotic Applications in Cardiac Surgery

Traditionally, cardiac surgery has been performed through a median sternotomy, which allows the surgeon generous access to the heart and surrounding great vessels. As a paradigm shift in the size and location of incisions occurs in cardiac surgery, new methods have been developed to allow the surgeon the same amount of dexterity and accessibility to the heart in confined spaces and in a less invasive manner. Initially, long instruments without pivot points were used, however, more recent robotic telemanipulation systems have been applied that allow for improved dexterity, enabling the surgeon to perform cardiac surgery from a distance not previously possible. In this rapidly evolving field, we review the recent history and clinical results of using robotics in cardiac surgery.
Highly enantioselective routes to Darzens and acetate aldol products from achiral aldehydes and t-butyl bromoacetate

Abstract New methodology is described for the enantioselective coupling of t-butyl bromoacetate with aldehydes to give anti-α-bromo β-hydroxy esters ( 1 ), useful precursors of chiral glycidic esters ( 2 ), acetate aldols ( 3 ), β-amino acid esters ( 4 ) and α-amino acid esters ( 5 ).
KINETIC THEORY AND HYDRODYNAMICS FOR A LOW DENSITY GRANULAR GAS

Many features of real granular fluids under rapid flow are exhibited as well by a system of smooth hard spheres with inelastic collisions. For such a system, it is tempting to apply standard methods of kinetic theory and hydrodynamics to calculate properties of interest. The domain of validity for such methods is a priori uncertain due to the inelasticity, but recent systematic studies continue to support the utility of kinetic theory and hydrodynamics as both qualitative and quantitative descriptions for many physical states. The basis for kinetic theory and hydrodynamic descriptions is discussed briefly for the special case of a low density gas.
Arbitration in Autumn

Often invoked as a metaphor for decline and decay, autumn also carries a sense of robust maturity bringing fruitful harvest and new beginnings. The season’s double symbolism evokes rival visions of arbitration today. Some observers see a golden age of cheap and cheerful proceedings as replaced by a costly complexity that fails arbitration’s promise of coherent and efficient dispute resolution. On closer scrutiny, however, arbitration reveals itself as having arrived at its autumn not in the sense of decay, but rather with vital maturity. Productive exchanges among the various stakeholders in the process serve to refine the counterpoise among accuracy, fairness and efficiency. Although any forecast remains tentative, most signs suggest that arbitration will continue to play a key role in promoting sound economic cooperation. Season of mists and mellow fruitfulness, close bosom-friend of the maturing sun, conspiring with him to load and bless, with fruit the vines that round the thatch-eves run. John Keats, Ode to Autumn (1819) 1
Chemoenzymatic synthesis of the Salmonella group E1 core trisaccharide using a recombinant β-(1→4)-mannosyltransferase

Abstract The chemical synthesis of the bacterial O-antigen from Salmonella serogroup E 1 , 3- O -(4- O -β- d -mannopyranosyl-α- l -rhamnopyranosyl)-α- d -galactose, presents a particular challenge because it contains a β-(1→4) mannosidic linkage to l -rhamnose. We report a chemoenzymatic synthesis of this crucial antigenic material which culminates in the enzymatic formation of the critical β-mannosyl connection catalyzed by Salmonella GDP-α- d -Man:αRha1→3αGal- PP -Und β-(1→4)-mannosyltransferase (ManT β4 ). In comparison with previous synthetic routes, this method is advantageous since it utilizes intermediates, available in significant yield, which can be readily derivatized from the reducing end to present flexibility for analog construction, while the enzymatic construction of the Man1→4Rha glycosidic bond is both rapid and occurs in high yield. Furthermore, the reported spectroscopic and enzymatic structural characterization of the trisaccharide product furnishes the first indisputable functional link between wba O and ManT β4 and clearly sets the stage for the future mechanistic study and exploitation of this fascinating glycocatalyst.
What Do Low-Income Single Mothers Say about Marriage?

Current theories of marriage under-predict the extent of non-marriage, have not been adequately tested, or do not apply well to women with low-socioeconomic status. Furthermore, scholarly research on marriage attitudes among low-SES women suffers from a lack of up-to-date qualitative work. This study draws on qualitative interviews with 292 low-income single' mothers in three U.S. cities. Inductive analysis reveals five primary motivations for non-marriage among low-income single mothers. Most mothers agree that potential marriage partners must earn significantly more than the minimum wage, but also emphasize the importance of stability of employment, source of earnings, and the effort men expend to find and keep their jobs. Mothers place equal or greater emphasis on non-monetary factors such as how marriage may diminish or enhance respectability, how it may limit their control over household decisions, their mistrust of men, and their fear of domestic violence. Affordability, respectability, and control have greater salience for African American mothers, while trust and domestic violence have greater salience for whites. The author discusses these findings in relation to existing theories of marriage and in light of welfare reform.
Water vapor penetration rate into enclosures with known air leak rates

The rate at which water vapor penetrates a faulty seal in a "hermetically sealed" device has been examined both experimentally and theoretically in this study. The experimental data were generated by studying the rate of moisture ingress into two types of packages; a TO-5 can and a ¼ × ¼ in ceramic flatpack. The TO-5 packages were fitted with capillary tubes of varying diameters with known air leak rates and represented the gross leak range (down to 10-5atm . cm3/s) while the ¼ × ¼ in ceramic flatpacks were used to study the fine leak range (10-6to 10-8atm . cm3/s). Both type packages were fitted with miniature moisture sensors (surface conductivity type) and calibrated at known relative humidities prior to sealing. The finished test packages were then exposed to constant high-humidity conditions and monitored for moisture content as a function of time. A theoretical analysis was performed by using conventional leak rate equations to convert air leak rates, at standard test conditions, to water vapor leak rates at partial pressure differentials seen typically at room ambient conditions. These data compared favorably with the experimental results in the range tested and suggests that present hermeticity specifications are too lenient for long-term reliability requirements.
The Invariant Proportion of Substitution Property (IPS) of Discrete-Choice Models

This article introduces a newly discovered property of discrete-choice models, which I call the invariant proportion of substitution (IPS). Like the independence from irrelevant alternatives (IIA) property, IPS implies individual behavior that is counterintuitive in the context of choice among similar alternatives. But models that alleviate the concerns raised by IIA, such as generalized extreme value and covariance probit models, do not necessarily alleviate the concerns raised by IPS. I explore the implications of the IPS property on individual behavior in several choice contexts and discuss some models that alleviate the concerns raised by IPS.
On the continuous equilibria of affiliated-value, all-pay auctions with private budget constraints☆

Abstract We consider all-pay auctions in the presence of interdependent, affiliated valuations and private budget constraints. For the sealed-bid, all-pay auction we characterize a symmetric equilibrium in continuous strategies for the case of N bidders. Budget constraints encourage more aggressive bidding among participants with large endowments and intermediate valuations. We extend our results to the war of attrition where we show that budget constraints lead to a uniform amplification of equilibrium bids among bidders with sufficient endowments. An example shows that with both interdependent valuations and private budget constraints, a revenue ranking between the two auction formats is generally not possible. Equilibria with discontinuous bidding strategies are discussed.
Uses of the word “macula” in written English, 1400–present

Abstract We compiled uses of the word “macula” in written English by searching multiple databases, including the Early English Books Online Text Creation Partnership, America's Historical Newspapers, the Gale Cengage Collections, and others. “Macula” has been used: as a non-medical “spot” or “stain”, literal or figurative, including in astronomy and in Shakespeare; as a medical skin lesion, occasionally with a following descriptive adjective, such as a color (macula alba); as a corneal lesion, including the earliest identified use in English, circa 1400; and to describe the center of the retina. Francesco Buzzi described a yellow color in the posterior pole (“retina tinta di un color giallo”) in 1782, but did not use the word “macula”. “Macula lutea” was published by Samuel Thomas von Sommering by 1799, and subsequently used in 1818 by James Wardrop, which appears to be the first known use in English. The Google n-gram database shows a marked increase in the frequencies of both “macula” and “macula lutea” following the introduction of the ophthalmoscope in 1850. “Macula” has been used in multiple contexts in written English. Modern databases provide powerful tools to explore historical uses of this word, which may be underappreciated by contemporary ophthalmologists.
Coulomb enhancement of ultrafast nonlinearities in quantum-well structures

The Coulomb interaction among photoexcited virtual carriers or virtual excitons in two-dimensional heterostructures is theoretically considered by using bare-states and the dressed-states approaches. It is shown that, if the wave functions of the ground and the excited states are spatially separated, then the Coulomb interaction causes coherent pulsations of the transition energy. As a result, significant (an order of magnitude) enhancement of the dynamic Stark shift and of other ultrafast nonlinearities can be achieved. The enhancement of ultrafast nonlinearities is evaluated as a function of the geometry, the doping level, broadening, and other parameters. The effects of the Coulomb interaction on coherent transient phenomena is considered. The problem of practical realization of the predicted effects is addressed.
Development and Analysis of a Self-Sensing Magnetostrictive Actuator Design:

A self-sensing magnetostrictive actuator design based on a linear systems model of magnetostrictive transduction for Terfenol-D is developed and analyzed. Self-sensing, or the ability of a transducer to sense its own motion as it is being driven, has been demonstrated for electromechanical transducers such as moving voice coil loudspeakers and, most recently, piezoelectric distributed moment actuators. In these devices, self-sensing was achieved by constructing a bridge circuit to extract a signal proportional to transducer motion even as the transducer was being driven. This approach is analyzed for a magnetostrictive device. Working from coupled electromechanical magnetostrictive transduction equations found in the literature, the concept of the transducer's "blocked" electrical impedance and motional impedance are developed, and a bridge design suggested and tested. However, results presented in this paper will show that magnetostrictive transduction is inherently non-linear, and does not, therefore, l...
Why watching movie tweets won't tell the whole story?

Data from Online Social Networks (OSNs) are providing analysts with an unprecedented access to public opinion on elections, news, movies, etc. However, caution must be taken to determine whether and how much of the opinion extracted from OSN user data is indeed reflective of the opinion of the larger online population. In this work we study this issue in the context of movie reviews on Twitter and compare the opinion of Twitter users with that of IMDb and Rotten Tomatoes. We introduce metrics to quantify how Twitter users can be characteristically different from general users, both in their rating and their relative preference for Oscar-nominated and non-nominated movies. We also investigate whether such data can truly predict a movie's box-office success.
Craving to Quit: psychological models and neurobiological mechanisms of mindfulness training as treatment for addictions

Humans suffer heavily from substance use disorders and other addictions. Despite much effort that has been put into understanding the mechanisms of the addictive process, treatment strategies have remained suboptimal over the past several decades. Mindfulness training, which is based on ancient Buddhist models of human suffering, has recently shown preliminary efficacy in treating addictions. These early models show remarkable similarity to current models of the addictive process, especially in their overlap with operant conditioning (positive and negative reinforcement). Further, they may provide explanatory power for the mechanisms of mindfulness training, including its effects on core addictive elements, such as craving, and the underlying neurobiological processes that may be active therein. In this review, using smoking as an example, we will highlight similarities between ancient and modern views of the addictive process, review studies of mindfulness training for addictions and their effects on craving and other components of this process, and discuss recent neuroimaging findings that may inform our understanding of the neural mechanisms of mindfulness training.
Sonographic Appearance of the Bladder After Endoscopic Incision of Ureteroceles

OBJECTIVE: Our intent was to describe the range of postoperative sonographic appearances of the bladder after endoscopic incision of ureteroceles. CONCLUSION: Preoperative and postoperative sonographic examinations of the bladder were reviewed in 14 patients (15 ureteroceles) who underwent endoscopic ureterocele incision. Five different appearances of the ureterovesical junction after endoscopic incision were found: a pseudomass (5/15), focal mucosal thickening (3/15), residual ureterocele with decrease in size (3/15), persistent unchanged ureterocele (1/15), and no residual abnormality (3/15). The most common postoperative sonographic appearance associated with development of vesicoureteral reflux was a mucosal pseudomass (4/6). The other bladder sonographic appearances had no correlation with development of reflux, degree of hydronephrosis, or success of the surgery.
Fully homomorphic encryption over the integers

We construct a simple fully homomorphic encryption scheme, using only elementary modular arithmetic. We use Gentry’s technique to construct a fully homomorphic scheme from a “bootstrappable” somewhat homomorphic scheme. However, instead of using ideal lattices over a polynomial ring, our bootstrappable encryption scheme merely uses addition and multiplication over the integers. The main appeal of our scheme is the conceptual simplicity. We reduce the security of our scheme to finding an approximate integer gcd – i.e., given a list of integers that are near-multiples of a hidden integer, output that hidden integer. We investigate the hardness of this task, building on earlier work of Howgrave-Graham.
Keynes's Philosophical Development

Preface Introduction: Keynes and philosophy 1. Keynes's early intuitionism 2. The dilemmas of Moore's Principia for ethics and economics 3. Keynes's self-critique 4. Keynes's later philosophy 5. The philosophical thinking of The General Theory 6. Ethics and policy Conclusion: Keynes's philosophical development Notes References Index.
Spin-dependent WIMPs in DAMA?

We investigate whether the annual modulation observed in the DAMA experiment can be due to a weakly-interacting massive particle (WIMP) with an axial-vector (spin-dependent; SD) coupling to nuclei. We evaluate the SD WIMP-proton cross section under the assumption that such scattering accounts for the DAMA modulation, and we do the same for a SD WIMP-neutron cross section. We show that SD WIMP-proton scattering is ruled out in a model-independent fashion by null searches for energetic neutrinos from WIMP annihilation in the Sun, and that SD WIMP-neutron scattering is ruled out for WIMP masses gtrsim20 GeV by the null result with the DAMA Xe detector. A SD WIMP with mass lesssim20 GeV is still compatible, but only if the SD WIMP-neutron interaction is four orders of magnitude greater than the WIMP-proton interaction.
Tidal dissipation in the oceans of icy satellites

Abstract Dissipation of tidal energy is an important mechanism for the evolution of outer Solar System satellites, several of which are likely to contain subsurface oceans. We extend previous theoretical treatments for ocean tidal dissipation by taking into account the effects of ocean loading, self-attraction, and deformation of the solid regions. These effects modify both the forcing potential and the ocean thicknesses for which energy dissipation is resonantly enhanced, potentially resulting in orders of magnitude changes in the dissipated energy flux. Assuming a Cassini state obliquity, Enceladus’ dissipated energy flux due to the obliquity tide is smaller than the observed value by many orders of magnitude. On the other hand, the dissipated energy flux due to the resonant response to the eccentricity tide can be large enough to explain Enceladus’ observed heat flow.
Nonlinear Robust Stochastic Control for Unmanned Aerial Vehicles

Almost all dynamical systems experience inherent uncertainties such as environmental disturbance, sensor noise, and modeling error due to approximations. In safety-critical applications, such as control of unmanned aerial vehicles, characterizing and controlling the statistical performance of the system become important tasks. This paper describes a new robust stochastic control methodology that is capable of controlling the statistical nature of state or output variables of a nonlinear system to desired (attainable) statistical properties (e.g., moments). First, as the online step, an asymptotically stable and robust output tracking controller is designed in which discontinuous functions are not involved. Second, as the offline step, undetermined control parameters in the closed-loop system are optimized through nonlinear programming. In this constrained optimization, the error between the desired and actual moments of state or output variables is minimized subject to constraints on statistical moments. As the key point to overcome the difficulties in solving the associated Fokker―Planck equation, a direct quadrature method of moments is proposed. In this approach, the state probability density function is expressed in terms of a finite collection of Dirac delta functions, with the associated weights and locations determined by moment equations. The advantages of the proposed method are 1) the ability to control any specified stationary moments of the states or output probability density function, 2) no need for the state process to be a Gaussian, and 3) robustness with respect to parametric and functional uncertainties. An unmanned aerial vehicle command-tracking control is used to demonstrate the capability of the proposed nonlinear stochastic control method and the results are successfully validated by Monte Carlo simulations.
Instrumentation pitfalls: You just can't go on autopilot!☆☆☆★

Instrumentation for total knee arthroplasty is crucial for proper positioning and orientation of the components. Instruments, however, must be used properly if the surgeon is to accomplish the goals. The entrance point for intramedullary guides for both the femur and tibia should not be arbitrarily chosen but picked after evaluation of the intersection of the anatomic axes of the respective bones with their articular surfaces. Saw blades must be held on cutting blocks, and the blocks themselves affixed to bones with sufficient pins to assure stability. If an extramedullary tibial alignment guide is chosen, its distal position should be in the center of the ankle plafond, not in the mid-malleolar point. In the lateral plane, it should parallel the shaft of the fibula. Femoral component rotation cannot always be judged from the posterior condylar tangent line. There may be difficulties of deformity with bone and cartilage loss, especially in valgus knees. Surgeons need to be mindful of the epicondylar axis and the midtrochlear of the anteroposterior axis of Whiteside.