cssi/SciSciGPT-SciSciNet huggingface dataset:
Increased Adiposity in Female Rhesus Monkeys Exposed to Androgen Excess During Early Gestation

Objective: The aim of this study was to investigate the effects of early-gestational androgen excess on adult body fat distribution in female rhesus monkeys. Methods: Six midreproductive-aged, adult, female rhesus monkeys that were exposed to androgen excess started during the first one-third of gestation were pair-matched to control women by age, body weight, and body mass index. Body composition was determined using somatometrics, dual x-ray absorptiometry, and computed tomography. Results: Total abdominal and intra-abdominal fat depots are increased in adult female rhesus monkeys exposed to prenatal androgen excess. Discussion: Early gestational androgen excess in female rhesus monkeys causes a preferential accumulation of total abdominal and intra-abdominal fat during adulthood. Fat accumulation in these regions is independent of total body adiposity, occurring throughout the spectrum of body mass index in these animals. This study establishes alterations in abdominal adiposity as another consequence ...
Maintaining the integrity of a changing power system

International competition has had a dramatic effect on heavy industry and its priorities. The new emphasis on product quality, cost reduction, pollution control, and redefined products has directly impacted electrical power systems designed in earlier eras to meet other needs. The author outlines methods and considerations for affecting a smooth and reliable transition to the future. The results of a low-voltage breaker high-current test survey conducted to investigate trip unit reliability are also presented. >
Non-microstates free entropy dimension for groups

We show that for any discrete finitely-generated group G and any self-adjoint n-tuple X1 ,...,X n of generators of the group algebra CG, Voiculescu's non-microstates free entropy dimension δ ∗ (X1 ,...,X n) is exactly equal to β1(G) − β0(G )+1 , whereβi are the � 2 -Betti numbers of G.
Luminous Hot Accretion Flows: Thermal Equilibrium Curve and Thermal Stability

In a previous paper, we presented the global solution of a new accretion flow model, namely, luminous hot accretion flows (LHAFs). In this Letter, we first show the corresponding thermal equilibrium curve of LHAFs in the mass accretion rate versus surface density diagram. Then we examine its thermal stability against local perturbations. We find that LHAFs are thermally unstable when thermal conduction is neglected. However, when the accretion rate is not very large, the timescale of the growth of perturbations is longer than the accretion timescale; therefore, the instability has no dynamical effect on the accretion flow. When the accretion rate is large, the perturbations can grow very fast at a certain radius. As a result, some cold clumps may form and the accretion flow will become multiphase.
The Role of Skill Versus Luck in Poker: Evidence from the World Series of Poker

In determining the legality of online poker—a multibillion dollar industry—courts have relied heavily on the issue of whether or not poker is a game of skill. Using newly available data, the author...
What are the risks associated with formula feeding? A re-analysis and review.

Abstract: Background: Most infant feeding studies present infant formula use as “standard” practice, supporting perceptions of formula feeding as normative and hindering translation of current research into counseling messages supportive of exclusive breastfeeding. To promote optimal counseling, and to challenge researchers to use exclusive breastfeeding as the standard, we have reviewed the scientific literature on exclusive breastfeeding and converted reported odds ratios to allow discussion of the “risks” of any formula use. Methods: Studies indexed in PubMed that investigated the association between exclusive breastfeeding and otitis media, asthma, types 1 and 2 diabetes, atopic dermatitis, and infant hospitalization secondary to lower respiratory tract diseases were reviewed. Findings were reconstructed with exclusive breastfeeding as the standard, and levels of significance calculated. Results: When exclusive breastfeeding is set as the normative standard, the re-calculated odds ratios communicate the risks of any formula use. For example, any formula use in the first 6 months is significantly associated with increased incidence of otitis media (OR: 1.78, 95% CI: 1.19, 2.70 and OR: 4.55, 95% CI: 1.64, 12.50 in the available studies; pooled OR for any formula in the first 3 mo: 2.00, 95% CI: 1.40, 2.78). Only shorter durations of exclusive breastfeeding are available to use as standards for calculating the effect of “any formula use” for type 1 diabetes, asthma, atopic dermatitis, and hospitalization secondary to lower respiratory tract infections. Conclusions: Exclusive breastfeeding is an optimal practice, compared with which other infant feeding practices carry risks. Further studies on the influence of presenting exclusive breastfeeding as the standard in research studies and counseling messages are recommended. (BIRTH 37:1 March 2010)
The Application of Channeling in Bent Crystals to Charged Particle Beams

The first serious suggestion that channeling in bent crystals could be used to deflect charged particles was made by E. Tsyganov in 1976.1 At that time he identified the possibility of using crystals for bending and focusing high energy beams. In 1979, a joint USSR-US team working at Dubna2 observed the deflection of channeled particles for the first time. The observations were made at an energy of 8.4 GeV and reached angles of up to 26 milliradians. These results have since been confirmed by measurements at CERN3 and at Fermilab.4–6 Much of the emphasis of the CERN work, done at a momentum of 12 GeV/c, has been on axial bending and on Monte Carlo studies of the process. A particular feature of the Fermilab program is a wide range of momenta (12 GeV/c to 800 GeV/c) so that something can be said about the functional momentum dependence of dechanneling and so that longer crystals can be used without a major impact from dechanneling. Some work has also been done at Gatchina7 near Leningrad at a relatively “low” energy of 1.0 GeV. This work particularly emphasizes feeding-in and feeding-out effects. All of these bending studies have been summarized in a recent review by Carrigan and Gibson.8
On State Counting and Characters

We outline the relationship between the thermodynamic densities and quasi-particle descriptions of spectra of RSOS models with an underlying Bethe equation. We use this to prove completeness of states in some cases and then give an algorithm for the construction of branching functions of their emergent conformal field theories. Starting from the Bethe equations of $D_n$ type, we discuss some aspects of the $Z_n$ lattice models.
Stochastic representations of ion channel kinetics and exact stochastic simulation of neuronal dynamics

In this paper we provide two representations for stochastic ion channel kinetics, and compare the performance of exact simulation with a commonly used numerical approximation strategy. The first representation we present is a random time change representation, popularized by Thomas Kurtz, with the second being analogous to a "Gillespie" representation. Exact stochastic algorithms are provided for the different representations, which are preferable to either (a) fixed time step or (b) piecewise constant propensity algorithms, which still appear in the literature. As examples, we provide versions of the exact algorithms for the Morris-Lecar conductance based model, and detail the error induced, both in a weak and a strong sense, by the use of approximate algorithms on this model. We include ready-to-use implementations of the random time change algorithm in both XPP and Matlab. Finally, through the consideration of parametric sensitivity analysis, we show how the representations presented here are useful in the development of further computational methods. The general representations and simulation strategies provided here are known in other parts of the sciences, but less so in the present setting.
A new adaptive law for robust adaptation without persistent excitation

A new adaptive law motivated by the work of loannou and Kokotovic (1983) is proposed for the robust adaptive control of plants with unknown parameters. In this adaptive law the output error plays a dual role in the adjustment of the control parameter vector. The advantages of using the adaptive law over others proposed in the literature are discussed. In the ideal case the adaptive system has bounded solutions; in addition, the origin of the error equations is exponentially stable when the reference input is persistently exciting and has a sufficiently large amplitude. The adaptive system is also shown to be robust under bounded external disturbances. Finally, it is shown that, by suitably modifying the adaptive law, the overall system can be made robust in the presence of a class of unmodeled dynamics of the plant. Simulation results are presented throughout the paper to complement the theoretical developments.
A study of some current methods of analysing observations of star-forming regions

We present an evaluative study of some current methods utilized in the analysis of infrared (IR) observations of star-forming regions. A series of self-consistent radiative transfer models are constructed, with the outputs analysed using these methods to infer source properties such as dust tempertaure, mass, opacity function, and density distribution. Any discrepancies between the inferred and model quantities can be attributed to the analysis methods. The range of validity of most methods is smaller than expected, due to two effects: (1) limited applicability of the Rayleigh-Jeans limit except to very long wavelengths, and (2) significant errors in the isothermal approxi
The bright end of the luminosity function of red sequence galaxies

We study the bright end of the luminosity distribution of galaxies in fields with luminous red galaxies (LRG) from the Sloan Digital Sky Survey (SDSS). Using 2099 deg 2 of SDSS imaging data, we search for luminous (≥L*) early-type galaxies within 1.0 h -1 Mpc of a volume-limited sample of 12608 spectroscopic LRG in the redshift range 0.12 < z < 0.38. Most of these objects lie in rich environments, with the LRG being the brightest object within 1.0h -1 Mpc. The luminosity gap, M 12 , between the first- and second-ranked galaxies within 1.0h -1 Mpc is large (∼0.8 mag), substantially larger than can be explained with an exponentially decaying luminosity function of galaxies. The brightest member is less luminous (by 0.1-0.2 mag) and shows a larger gap in LRG selected groups than in cluster-like environments. The large luminosity gap shows little evolution with redshift to z = 0.4, ruling out the scenario that these LRG selected brightest cluster or group galaxies grow by recent cannibalism of cluster members.
Changes in the employment contract?: Evidence from a quasi-experiment☆

Abstract Many authors have discussed an apparent shift to a new employment contract characterized by less commitment between employer and employee, and closer ties between wages within the enterprise and those in the external labor market. We study the issue of when people in the US and Canada feel pay cuts are fair. In contrast to much previous discussion, we find no evidence of increasing acceptance of pay cuts—a measure of whether external, not internal, labor markets are considered fair. These results suggest that new organizational forms might do well to preserve some features of the “old” employment contract.
Internal stabilization and decoupling in linear multivariable systems by unity output feedback compensation

We consider the problem of internally stabilizing and simultaneously diagonally decoupling a linear multivariable system by unity output feedback compensation. A sufficient condition is derived for the existence of a cascade proper compensator C(s) such that when employed in a unity feedback loop involving the proper transfer function matrix P o of a free of unstable hidden modes system \Sigma(P_{o}) , will not only internally stabilize the feedback closed-loop system \Sigma(P_{o}, C) but will also give rise to a closed-loop transfer function matrix H_{yr}^{diag} , which is nonsingular, diagonal, and has desired poles. Based on this analysis, an algorithmic procedure for the computation of such a compensator is presented.
Desordénes gastronómicos: metáfora literaria compleja en la narrativa de Ana María del Río y Andrea Maturana

Este articulo examina las complejas causas, sintomas y consecuencias de la anorexia nervosay la bulimia y su representacion en la narrativa de dos escritoras chilenas contemporaneas:Ana Maria del Rio y Andrea Maturana. Propongo que las manifestaciones fisicas y psico-logicas de estos trastornos gastronomicos estan intimamente relacionadas con complejosproblemas multifactoriales que muestran los diversos modos en que las protagonistas serelacionan con su medio social. La novela
The Top quark: Experimental roots and branches of theory

Even before the top quark was discovered by the CDF[1] and DO[2] experiments in 1995, several of its properties could be deduced from those of its weak partner, the bottom quark. The increment in the measured[3] value of \( R = \frac{{\sigma (e^ + e^ - \to hadrons)}} {{\sigma (e^ + e^ - \to \mu ^ + \mu ^ - )}} \) at the b threshold agreed with the predicted δESM = 1/3, confirming Q b = -1/3. Likewise, data[4] on the front-back asymmetry for electroweak b-quark production confirmed that 3T b = -1/2. Therefore, the b quark’s weak partner in the SM was required to be a color-triplet, spin-1/2 fermion with electric charge Q = 2/3 and weak charge T 3= 1/2.
An offer you can’t refuse? Provider-initiated HIV testing in antenatal clinics in rural Malawi

International organizations promote provider-initiated, ‘routine’ HIV testing of pregnant women seeking antenatal care as an effort to curb mother-to-child transmission. We offer an account of the perceptions of HIV testing at antenatal clinics in rural Malawi. Although it is both international and Government of Malawi policy that women must be explicitly informed of their right to refuse testing, analysis of in-depth interviews, focus group discussions and evidence from observational field journals show that rural Malawians do not perceive HIV testing as a choice, but rather as compulsory in order to receive antenatal care. This study illustrates dissonance between global expectations and local realities of the delivery of HIV-testing interventions. Keyword HIV testing, antenatal care, rights, Malawi
anti-1,2-Diols via Ni-Catalyzed Reductive Coupling of Alkynes and α-Oxyaldehydes

Ni-catalyzed reductive coupling of aryl alkynes (1) and enantiomerically enriched α-oxyaldehydes (2) afford differentiated anti-1,2-diols (3) with high diastereoselectivity and regioselectivity, despite the fact that the methoxymethyl (MOM) and para-methoxybenzyl (PMB) protective groups typically favor syn-1,2-diol formation in carbonyl addition reactions of this family of aldehydes.
Second-line drug therapy for osteoarthritis

L'activite biologique des medicaments antibiotiques ou antiinflammatoires destines a traiter l'osteite est decrite, ainsi que leurs effets indesirables
Emancipating Transitional Justice from the Bonds of the Paradigmatic Transition

If transitional justice initially emerged as handmaiden to liberal political transitions, it has increasingly become associated with postconflict peacebuilding more generally. While this may suggest a significant moment in the evolution of the field’s foundational paradigm, it remains unclear what any emerging ‘transitional justice as peacebuilding’ narrative might mean in practice and how, if at all, it might differ from what came before. I argue that the particular conceptions of ‘transition,’ ‘justice’ and ‘peacebuilding’ that come to undergird any such emerging narrative matter a great deal. This article seeks to deconstruct each component of that narrative based on historically dominant and narrow assumptions about what they can and should mean in the aftermath of mass atrocity. I look to concepts from critical peacebuilding theory – including ‘positive peace,’ ‘popular peace,’ ‘the everyday’ and ‘hybridity’ – that might serve as useful correctives to these narrow assumptions, bridging the way to a more emancipatory ‘transitional justice as peacebuilding’ narrative.
Pattern avoidance and the Bruhat order

The structure of order ideals in the Bruhat order for the symmetric group is elucidated via permutation patterns. The permutations with boolean principal order ideals are characterized. These form an order ideal which is a simplicial poset, and its rank generating function is computed. Moreover, the permutations whose principal order ideals have a form related to boolean posets are also completely described. It is determined when the set of permutations avoiding a particular set of patterns is an order ideal, and the rank generating functions of these ideals are computed. Finally, the Bruhat order in types B and D is studied, and the elements with boolean principal order ideals are characterized and enumerated by length.
Can extra dimensions accessible to the SM explain the recent measurement of anomalous magnetic moment of the muon

Abstract We investigate whether models with flat extra dimensions in which SM fields propagate can give a significant contribution to the anomalous magnetic moment of the muon (MMM). In models with only SM gauge and Higgs fields in the bulk, the contribution to the MMM from Kaluza–Klein (KK) excitations of gauge bosons is very small. This is due to the constraint on the size of the extra dimensions from tree-level effects of KK excitations of gauge bosons on precision electroweak observables such as Fermi constant. If the quarks and leptons are also allowed to propagate in the (same) bulk (“universal” extra dimensions), then there are no contributions to precision electroweak observables at tree-level. However, in this case, the constraint from one-loop contribution of KK excitations of (mainly) the top quark to T parameter again implies that the contribution to the MMM is small. We show that in models with leptons, electroweak gauge and Higgs fields propagating in the (same) bulk, but with quarks and gluon propagating in a sub-space of this bulk, both the above constraints can be relaxed. However, with only one Higgs doublet, the constraint from the process b→sγ requires the contribution to the MMM to be smaller than the SM electroweak correction. This constraint can be relaxed in models with more than one Higgs doublet.
Predicate abstraction with indexed predicates

Predicate abstraction provides a powerful tool for verifying properties of infinite-state systems using a combination of a decision procedure for a subset of first-order logic and symbolic methods originally developed for finite-state model checking. We consider models containing first-order state variables, where the system state includes mutable functions and predicates. Such a model can describe systems containing arbitrarily large memories, buffers, and arrays of identical processes. We describe a form of predicate abstraction that constructs a formula over a set of universally quantified variables to describe invariant properties of the first-order state variables. We provide a formal justification of the soundness of our approach and describe how it has been used to verify several hardware and software designs, including a directory-based cache coherence protocol.
Peace and War With Endogenous State Capacity

We explore how peace or war can occur in the presence of commitment problems. These problems can be reduced by institutions of good governance or, alternatively, state capacity which (a) can be considered a collective good and (b) can be improved through investments. We show how the likelihood of a peace agreement depends on the level of state capacity and on investments in state capacity made by adversaries. In accordance with existing evidence but contrary to various theories of conflict, we find that income levels unambiguously increase the chance of peace. Among other issues, we discuss the critical role of external actors in encouraging or discouraging commitment and in developing good governance institutions.
Modal analysis of an Upper Nevada penstock at Hoover Dam

A 4-meter-diameter penstock at the Hoover Dam power plant has been vibrating since 1996. Project personnel were concerned that the vibration could cause fatigue damage to the penstock system. An investigation was performed using a modal survey to locate strain gages in the fatigue-critical areas. Operational stresses were collected and indicated that no fatigue damage was occurring. A finite element model was developed, but because of the difficulty in defining the degree of restraint at the supports, the mode shapes did not correlate with the prototype's response. The investigation demonstrated that even though the penstock was a large complicated structure, a limited modal analysis and strain gaging were successful in answering the questions concerning fatigue damage.
Gun violence and victimization of strangers by persons with a mental illness: data from the MacArthur Violence Risk Assessment Study

Objective:Highly publicized incidents in which people with apparent mental illnesses use guns to victimize strangers have important implications for public views of people with mental illnesses and the formation of mental health and gun policy. The study aimed to provide more data about this topic.Methods:MacArthur Violence Risk Assessment Study data were analyzed to determine the prevalence of violence by 951 patients after discharge from a psychiatric hospital, including gun violence, violence toward strangers, and gun violence toward strangers.Results:Two percent of patients committed a violent act involving a gun, 6% committed a violent act involving a stranger, and 1% committed a violent act involving both a gun and a stranger.Conclusions:When public perceptions and policies regarding mental illness are shaped by highly publicized but infrequent instances of gun violence toward strangers, they are unlikely to help people with mental illnesses or to improve public safety.
A glossary for social epidemiology

Why “social epidemiology”? Is not all epidemiology, after all, “social” epidemiology? In so far as people are simultaneously social and biological organisms, is any biological process ever expressed devoid of social context?—or any social process ever unmediated by the corporal reality of our profoundly generative and mortal bodies?1 2 Yet, despite the seeming truism that social as well as biological processes inherently shape population health—a truism recognised even in the founding days of epidemiology as a scientific discipline in the early 19th century—not all epidemiology is “social epidemiology”.3 4 Instead, “social epidemiology” (which first attained its name as such in English in 19503 5) is distinguished by its insistence on explicitly investigating social determinants of population distributions of health, disease, and wellbeing, rather than treating such determinants as mere background to biomedical phenomena. Tackling this task requires attention to theories, concepts, and methods conducive to illuminating intimate links between our bodies and the body politic; toward this end, the glossary below provides a selection of critical terms for the field. One brief note of explanation. Some entries contain only one term; others include several related terms whose meanings are interdependent or refer to specific aspects of a broader construct. Additionally, each entry is cast in relation to its significance to social epidemiology; explication of salience to other disciplines is beyond the scope of this particular glossary. Biological expressions of social inequality refers to how people literally embody and biologically express experiences of economic and social inequality, from in utero to death, thereby producing social inequalities in health across a wide spectrum of outcomes.1 2 6 Core to social epidemiology, this construct of “biological expressions of social inequality” has been evident in epidemiological thought—albeit not always explicitly named as such—since the discipline's emergence in the early 19th …
Residential Mobility, Family Structure, and The Cell-Only Population

The cell-phone-only (CPO) population has grown rapidly over the past several years, causing concern for researchers who rely mostly on random digit dialing (RDD) of landlines to conduct their re- search. While early research on CPOs has focused largely on age differences, CPOs may differ from those with landlines in many other ways even after controlling for age. In this article, we use the Coopera- tive Congressional Election Study—an Internet survey based on matched random sampling—and the American National Election Study—an in-person survey based on stratified residential sampling— to examine the potential effects of the cell-only population for survey research. These surveys are ideal for studying the causes and conse- quences of cell-only lifestyles for survey research because they reach cell-only and landline respondents through a single sampling frame. We reach two main conclusions: (1) CPO households are not simply a function of age, but of other factors as well, especially residential mobil- ity and family structure; and (2) there are notable differentials in vote preferences and turnout between CPOs and others.
Little Higgs models and their phenomenology

This article reviews the Little Higgs models of electroweak symmetry breaking and their phenomenology. Little Higgs models incorporate a light composite Higgs boson and remain perturbative until a scale of order 10 TeV, as required by precision electroweak data. The collective symmetry breaking mechanism, which forms the basis of Little Higgs models, is introduced. An explicit, fully realistic implementation of this mechanism, the Littlest Higgs model, is then discussed in some detail. Several other implementations, including simple group models and models with T parity, are also reviewed. Precision electroweak constraints on a variety of Little Higgs models are summarized. If a Little Higgs model is realized in nature, the predicted new particles should be observable at the Large Hadron Collider (LHC). The expected signatures, as well as the experimental sensitivities and the possible strategies for confirming the Little Higgs origin of new particles, are discussed. Finally, several other related topics are briefly reviewed, including the ultraviolet completions of Little Higgs models, as well as the implications of these models for flavor physics and cosmology.
X-Ray IGM in the Local Group

Recent observations with the dispersive X-ray spectrometers aboard Chandra and Newton Observatory have begun to probe the properties of the X-ray intergalactic medium (IGM) at small redshifts. Using large quantities (∼950 ksec) of spectroscopic data acquired using the Reflection Grating Spectrometer (RGS) aboard Newton Observatory, we investigated the intervening material toward three low redshift, high Galactic latitude Active Galactic Nuclei (AGNs) with nominally featureless spectra: Mrk 421, PKS 2155-304 and 3C 273. Each spectrum provides clear evidence for what appears to be a local (z ∼ 0), highly ionized absorbing medium betrayed by the O VII 1s–2p resonance transition feature seen at 21.6 A (NOVII ∼ 1016 m-2). Measurements are also made for the Ly α transition of the adjacent ionization state, (O VIII; 18.97 A), which potentially constrains the absorber’s temperature. Finally, in a collisional equilibrium approximation, upper limits to diffuse emission intensities place upper limits on the electron density (n e 140 kpc) and lower limits on its mass (M > 5 x 1010 M⊙). Limits on the absorber’s scale length and its velocity distribution lead us to identify it with the Local Group. Having detected the hot gas in our Local Group in absorption, it should be feasible to detect also the extended structure of other low-mass, spiral-dominated groups of galaxies in absorption, with spectra of similar quality.
LOOP VARIABLES AND GAUGE INVARIANT INTERACTIONS OF MASSIVE MODES IN STRING THEORY

The loop variable approach used earlier to obtain free equations of motion for the massive modes of the open string, is generalized to include interaction terms. These terms, which are polynomial, involve only modes of strictly lower mass. Considerations based on operator product expansions suggest that these equations are particular truncations of the full string equations. The method involves broadening the loop to a band of finite thickness that describes all the different interacting strings. Interestingly. in terms of these variables. the theory appears non-interacting.
Pompanopeptins A and B, new cyclic peptides from the marine cyanobacterium Lyngbya confervoides

Abstract A new 3-amino-6-hydroxy-2-piperidone (Ahp) containing peptolide, pompanopeptin A ( 1 ), and a novel N -methyl-2-amino-6-(4′-hydroxyphenyl)hexanoic acid ( N -Me-Ahpha) containing cyclic pentapeptide connected with a sixth amino acid residue via a rare ureido linkage, pompanopeptin B ( 2 ), were isolated from the marine cyanobacterium Lyngbya confervoides collected from the southeastern coast of Florida. Their planar structures were determined by a combination of NMR spectroscopic analysis and mass spectrometry. The absolute configurations were established using advanced Marfey's method and chiral HPLC analysis of the chemical degradation products. Compound 1 selectively inhibited trypsin over elastase and chymotrypsin, with an IC 50 value of 2.4 μM; selectivity is conferred by an arginine residue in the cyclic core.
Collapsar Accretion and the Gamma-Ray Burst X-Ray Light Curve

We present axisymmetric hydrodynamical simulations of the long-term accretion of a rotating gamma-ray burst (GRB) progenitor star, a "collapsar," onto the central compact object, which we take to be a black hole. The simulations were carried out with the adaptive-mesh-refinement code FLASH in two spatial dimensions and with an explicit shear viscosity. The evolution of the central accretion rate exhibits phases reminiscent of the long GRB γ-ray and X-ray light curve, which lends support to the proposal by Kumar et al. that the luminosity is modulated by the central accretion rate. In the first "prompt" phase, the black hole acquires most of its final mass through supersonic quasiradial accretion occurring at a steady rate of ~0.2 M ☉ s–1. After a few tens of seconds, an accretion shock sweeps outward through the star. The formation and outward expansion of the accretion shock is accompanied with a sudden and rapid power-law decline in the central accretion rate , which resembles the L X ∝ t –3 decline observed in the X-ray light curves. The collapsed, shock-heated stellar envelope settles into a thick, low-mass equatorial disk embedded within a massive, pressure-supported atmosphere. After a few hundred seconds, the inflow of low angular momentum material in the axial funnel reverses into an outflow from the thick disk. Meanwhile, the rapid decline of the accretion rate slows down, which is potentially suggestive of the "plateau" phase in the X-ray light curve. We complement our adiabatic simulations with an analytical model that takes into account the cooling by neutrino emission and estimate that the duration of the prompt phase can be ~20 s. The model suggests that the steep decline in GRB X-ray light curves is triggered by the circularization of the infalling stellar envelope at radii where the virial temperature is below 1010 K, such that neutrino cooling is inefficient and an outward expansion of the accretion shock becomes imminent; GRBs with longer prompt γ-ray emission should have more slowly rotating envelopes.
A Prime Sensitive Hankel Determinant of Jacobi Symbol Enumerators

We show that the determinant of a Hankel matrix of odd dimension n whose entries are the enumerators of the Jacobi symbols which depend on the row and the column indices vanishes if and only if n is composite. If the dimension is a prime p, then the determinant evaluates to a polynomial of degree p − 1 which is the product of a power of p and the generating polynomial of the partial sums of Legendre symbols. The sign of the determinant is determined by the quadratic character of −1 modulo p. The proof of the evaluation makes use of elementary properties of Legendre symbols, quadratic Gauss sums, and orthogonality of trigonometric functions.
Why Public Schools Lose Teachers

Many school districts experience difficulties attracting and retaining teachers, and the impending retirement of a substantial fraction of public school teachers raises the specter of severe shortages in some public schools. Schools in urban areas serving economically disadvantaged and minority students appear particularly vulnerable. This paper investigates those factors that affect the probabilities that teachers switch schools or exit the public schools entirely. The results indicate that teacher mobility is much more strongly related to characteristics of the students, particularly race and achievement, than to salary, although salary exerts a modest impact once compensating differentials are taken into account.
Multilinear formulas and skepticism of quantum computing

Several researchers, including Leonid Levin, Gerard 't Hooft, and Stephen Wolfram, have argued that quantum mechanics will break down before the factoring of large numbers becomes possible. If this is true, then there should be a natural set of quantum states that can account for all quantum computing experiments performed to date, but not for Shor's factoring algorithm. We investigate as a candidate the set of states expressible by a polynomial number of additions and tensor products. Using a recent lower bound on multilinear formula size due to Raz, we then show that states arising in quantum error-correction require nΩ(log n) additions and tensor products even to approximate, which incidentally yields the first superpolynomial gap between general and multilinear formula size of functions. More broadly, we introduce a complexity classification of pure quantum states, and prove many basic facts about this classification. Our goal is to refine vague ideas about a breakdown of quantum mechanics into specific hypotheses that might be experimentally testable in the near future.
Ultra-Low Bending Loss Single-Mode Fiber for FTTH

A new ultra-low bending loss single-mode fiber with ring comprising nanometer sized features is designed and manufactured. Bending loss less than 0.1 dB/turn at 1550 nm and a bend radius of 5 mm is demonstrated. Other optical parameters of the fiber are fully compatible the standard telecommunications grade single-mode fibers.
Merging of Aircraft Trailing Vortices

A merging distance criterion for equal-strength corotational vortices is derived from low-turbulence wind tunnel flow visualization data. The vortex separation distance is normalized by defining a vortex core diameter based on circulation defect and angular momentum defect. Merging may take place for larger separation distances than predicted from earlier two-dimensional inviscid calculations, which indicates that viscosity and possibly three-dimensional effects are important factors in the merging phenomenon. Hot-wire velocity distributions and rolling moment measurements show that attenuation of the vortex hazard is associated with vortex merging. Nomenclature bg = generator wingspan bf = follower wingspan CL = lift coefficient cf = rolling-moment coefficient c = wing chord d = vortex separation distance d0 = initial vortex separation distance dc = vortex core diameter (usually based on peak tangential speed) dM = vortex core diameter (based on angular momentum defect equal to that in a Rankine vortex) dr = vortex core diameter (based on circulation defect equal to that in a Rankine vortex) dv —vortex core diameter (based on outer boundary of.the rotational portion of the vortex)
Why Do Firms Issue Equity After Splitting Stocks

This paper examines the motivations of firms that conduct seasoned equity offerings (SEOs) after splitting stocks. We find no difference in equity announcement and issue period returns between these firms and other equity-issuing firms, suggesting that firms do not split stocks to reveal information and reduce adverse selection costs at the subsequent SEO. However, because investors react positively to split announcements, firms that issue equity after splitting stocks sell new shares at a higher price and raise more funds. We also find that firms split stocks to make the subsequent SEO more marketable to individual investors who are attracted to low-priced shares.
Cultivate or Rent Out? Land Security in Rural Thailand

In the 1980s the Thai government tried to legalize squatters by issuing special titles that restricted the sale and rental of the land. Using data from 2,874 farming households collected in 1997, the author finds that in places where these government titles where issued, leased plots are more likely to be titled than those that are self-cultivated. For these areas, he uses a model to estimate a 6 percent risk premium in the rental rate for untitled plots. In other areas, however, land rights play no role in the decision to lease land and the rental rate of untitled plots does not include a risk premium. The results indicate that this policy distorted the land rental market by triggering a sense of insecurity among landowners.
Chemistry and Biology of Biosynthetic Diels–Alder Reactions

Nature's repertoire of biosynthetic transformations has recently been recognized to include the Diels-Alder cycloaddition reaction. Evidence now exists that there are enzymes that mediate the Diels-Alder reaction in secondary metabolic biosynthetic pathways. 2002 marked the 100th anniversary of Alder's birth and 75 years since the discovery of the Diels-Alder reaction. It would appear that living systems discovered and made use of this ubiquitously useful ring-forming reaction eons ago for the construction of complex natural products. In this Review an overview is given of all of the known classes of natural products (polyketides, isoprenoids, phenylpropanoids, alkaloids) that have been speculated to arise by a biological Diels-Alder reaction.
Influence of Life Stress on Depression: Moderation by a Polymorphism in the 5-HTT Gene

In a prospective-longitudinal study of a representative birth cohort, we tested why stressful experiences lead to depression in some people but not in others. A functional polymorphism in the promoter region of the serotonin transporter (5-HT T) gene was found to moderate the influence of stressful life events on depression. Individuals with one or two copies of the short allele of the 5-HT T promoter polymorphism exhibited more depressive symptoms, diagnosable depression, and suicidality in relation to stressful life events than individuals homozygous for the long allele. This epidemiological study thus provides evidence of a gene-by-environment interaction, in which an individual's response to environmental insults is moderated by his or her genetic makeup.
Information Exchange and Learning Dynamics Over Weakly Connected Adaptive Networks

This paper examines the learning mechanism of adaptive agents over weakly connected graphs and reveals an interesting behavior on how information flows through such topologies. The results clarify how asymmetries in the exchange of data can mask local information at certain agents and make them totally dependent on other agents. A leader-follower relationship develops with the performance of some agents being fully determined by the performance of other agents that are outside their domain of influence. This scenario can arise, for example, due to intruder attacks by malicious agents or as the result of failures by some critical links. The findings in this paper help explain why strong-connectivity of the network topology, adaptation of the combination weights, and clustering of agents are important ingredients to equalize the learning abilities of all agents against such disturbances. The results also clarify how weak-connectivity can be helpful in reducing the effect of outlier data on learning performance.
Numerical simulations of hot halo gas in galaxy mergers

Galaxy merger simulations have explored the behaviour of gas within the galactic disc, yet the dynamics of hot gas within the galaxy halo have been neglected. We report on the results of high-resolution hydrodynamic simulations of colliding galaxies with metal-free hot halo gas. To isolate the effect of the halo gas, we simulate only the dark matter halo and the hot halo gas over a range of mass ratios, gas fractions and orbital configurations to constrain the shocks and gas dynamics within the progenitor haloes. We find that (i) a strong shock is produced in the galaxy haloes before the first passage, increasing the temperature of the gas by almost an order of magnitude to T ∼ 10 6.3 K. (ii) The X-ray luminosity of the shock is strongly dependent on the gas fraction; it is ≥ 10 39 erg s ―1 for halo gas fractions larger than 10 per cent. (iii) The hot diffuse gas in the simulation produces X-ray luminosities as large as 10 42 erg s ―1 . This contributes to the total X-ray background in the Universe. (iv) We find an analytic fit to the maximum X-ray luminosity of the shock as a function of merger parameters. This fit can be used in semi-analytic recipes of galaxy formation to estimate the total X-ray emission from shocks in merging galaxies. (v) ∼10-20 per cent of the initial gas mass is unbound from the galaxies for equal-mass mergers, while 3-5 per cent of the gas mass is released for the 3:1 and 10: mergers. This unbound gas ends up far from the galaxy and can be a feasible mechanism to enrich the intergalactic medium with metals.
A proposed new international TNM staging system for malignant pleural mesothelioma from the International Mesothelioma Interest Group.

Abstract Study objective: investigation of the behavior and treatment of diffuse malignant pleural mesothelioma (MPM) is hindered by the lack of an accurate universally accepted staging system. To address this problem, the International Mesothelioma Interest Group (IMIG) has developed a new TNM based staging system. Methods: the staging system was developed at a consensus meeting of IMIG members involved in clinical research in MPM, including the originators of previously proposed staging systems. The new staging system is based on the analysis of emerging information about the impact of T and N status on survival. Results: in contrast to five previous staging systems, the T descriptors designated as T1, T2, T3 and T4, provide precise anatomic definitions of the local extent of the primary tumour. The N descriptors, designated as N0, N1, N2 and N3, are virtually identical to those used in the International Lung Cancer Staging System. The stage groupings recognize new data about the better prognosis of T1 and N0 tumours and classify those tumours into stages I and II. The adverse impact of nodal metastases on survival noted in some recent surgical series warrants placing node positive tumours in stage III. Locally advanced unresectable (T4) tumours and extrathoracic disease (N3 or M1) are classified as stage IV. Conclusion: this proposed staging system reconciles and updates several earlier systems, and can provide the framework for analyzing the results of prospective clinical trials aimed at improving the currently dismal prognosis of MPM.
Emergence of kinetic behavior in streaming ultracold neutral plasmas

We create streaming ultracold neutral plasmas by tailoring the photoionizing laser beam that creates the plasma. By varying the electron temperature, we control the relative velocity of the streaming populations, and, in conjunction with variation of the plasma density, this controls the ion collisionality of the colliding streams. Laser-induced fluorescence is used to map the spatially resolved density and velocity distribution function for the ions. We identify the lack of local thermal equilibrium and distinct populations of interpenetrating, counter-streaming ions as signatures of kinetic behavior. Experimental data are compared with results from a one-dimensional, two-fluid numerical simulation.
Ehrhart Series and Lattice Triangulations

We express the generating function for lattice points in a rational polyhedral cone with a simplicial subdivision in terms of multivariate analogues of the h-polynomials of the subdivision and “local contributions” of the links of its nonunimodular faces. We also compute new examples of nonunimodal h *-vectors of reflexive polytopes.
Students Lost in a Flattened World: How Resources from the Catholic Tradition Can Help Business Students Find Their Way

Academically Adrift, the recent study of undergraduate performance, has revealed that college students are learning little, if anything, over the course of their four years at university. This article suggests that students are academically adrift, in part, because Americans are culturally marooned between two ways to pursue happiness, neither of which is viable. A Catholic education can offer a different vision of how a person cannot merely fi nd but, to use Aristotelian language, actualize happiness in his or her life. The Catholic tradition has resources that any professor can draw upon to begin to anchor students to some point of being on which they can build a satisfying life. At the end of the article, the author suggests concrete ways in which professors can deploy these resources within the classroom.
IsoDOT Detects Differential RNA-Isoform Expression/Usage With Respect to a Categorical or Continuous Covariate With High Sensitivity and Specificity

We have developed a statistical method named IsoDOT to assess differential isoform expression (DIE) and differential isoform usage (DIU) using RNA-seq data. Here isoform usage refers to relative isoform expression given the total expression of the corresponding gene. IsoDOT performs two tasks that cannot be accomplished by existing methods: to test DIE/DIU with respect to a continuous covariate, and to test DIE/DIU for one case versus one control. The latter task is not an uncommon situation in practice, for example, comparing the paternal and maternal alleles of one individual or comparing tumor and normal samples of one cancer patient. Simulation studies demonstrate the high sensitivity and specificity of IsoDOT. We apply IsoDOT to study the effects of haloperidol treatment on the mouse transcriptome and identify a group of genes whose isoform usages respond to haloperidol treatment. Supplementary materials for this article are available online.
Energy-Aware Wireless Scheduling With Near-Optimal Backlog and Convergence Time Tradeoffs

This paper considers a wireless link with randomly arriving data that are queued and served over a time-varying channel. It is known that any algorithm that comes within $\epsilon $ of the minimum average power required for queue stability must incur average queue size at least $\Omega (\log (1/\epsilon ))$ . However, the optimal convergence time is unknown. This paper develops a scheduling algorithm that, for any $\epsilon >0$ , achieves the optimal $O(\log (1/\epsilon ))$ average queue size tradeoff with a convergence time of $O(\log (1/\epsilon )/\epsilon )$ . An example system is presented for which all algorithms require convergence time at least $\Omega (1/\epsilon )$ , and so the proposed algorithm is within a logarithmic factor of the optimal convergence time. The method uses the simple drift-plus-penalty technique with an improved convergence time analysis.
The enantioselective fluoroacetamide acetal claisen rearrangements of N-fluoroacetyl-trans-(2R,5R)-2,5-dimethylpyrrolidine

Abstract Optically active monofluorinated amides were prepared via the amide acetal Claisen rearrangement and the establishment of the absolute stereochemistry of the rearranged products proved that the chiral auxiliary directed the approach of the crotyl fragment to the Si face of the ( E )- N,O -ketene acetal. The general utility of this type of rearrangement is also discussed.