cssi/SciSciGPT-SciSciNet huggingface dataset:
Spin Generation Via Bulk Spin Current in Three Dimensional Topological Insulators

To date, spin generation in three-dimensional topological insulators is primarily modelled as a single-surface phenomenon, attributed to the momentum-spin locking on each individual surface. In this article, we propose a mechanism of spin generation where the role of the insulating yet topologically non-trivial bulk becomes explicit: an external electric field creates a transverse pure spin current through the bulk of a three-dimensional topological insulator, which transports spins between the top and bottom surfaces. Under sufficiently high surface disorder, the spin relaxation time can be extended via the Dyakonov-Perel mechanism. Consequently, both the spin generation efficiency and surface conductivity are largely enhanced. Numerical simulation confirms that this spin generation mechanism originates from the unique topological connection of the top and bottom surfaces and is absent in other two-dimensional systems such as graphene, even though they possess a similar Dirac cone-type dispersion.
OBSERVATIONS OF SUPERNOVAE

The observations of supernovae are reviewed and their main implications are shortly discussed.
Alexander polynomials of equivariant slice and ribbon knots in S^3

This paper gives an algebraic characterization of Alexander polynomials of equivariant ribbon knots and a factorization condition satisfied by Alexander polynomials of equivariant slice knots.
Floer theory and its topological applications

We survey the different versions of Floer homology that can be associated to three-manifolds. We also discuss their applications, particularly to questions about surgery, homology cobordism, and four-manifolds with boundary. We then describe Floer stable homotopy types, the related Pin(2)-equivariant Seiberg–Witten Floer homology, and its application to the triangulation conjecture.
Fidelity Decay Saturation Level for Initial Eigenstates

We show that the fidelity decay between an initial eigenstate evolved under a unitary chaotic operator and the same eigenstate evolved under a perturbed operator saturates well before the 1/N limit expected for a generic initial state, where N is the dimension of the Hilbert space. We provide a theoretical argument and numerical evidence that, for perturbations of intermediate strength, the saturation level depends quadratically on the perturbation strength. PACS: 05.45.Mt; 03.67.Lx
Sirtuin 6 regulates glucose-stimulated insulin secretion in mouse pancreatic beta cells

Aims/hypothesis Sirtuin 6 (SIRT6) has been implicated in ageing, DNA repair and metabolism; however, its function in pancreatic beta cells is unclear. The aim of this study is to elucidate the role of SIRT6 in pancreatic beta cells.
Improving Store Liquidation

Store liquidation is the time-constrained divestment of retail outlets through an in-store sale of inventory. The retail industry depends extensively on store liquidation, both to allow managers of going concerns to divest stores in efforts to enhance performance and as a means for investors to recover capital from failed ventures. Retailers sell billions of dollars of inventory annually during store liquidations. This paper introduces the store liquidation problem to the literature and presents a technique for optimizing key store liquidation decisions, including markdowns, inventory transfers, and the timing of store closings. We propose a heuristic for solving the store liquidation problem and evaluate the performance of this method. Through applications, we show that our approach could improve net recovery on cost (i.e., the profit obtained during a liquidation stated as a percentage of the cost value of liquidated inventory) by two to five percentage points in the cases we examined. Further, we discu...
A switched dynamical system framework for analysis of massively parallel asynchronous numerical algorithms

In the near future, massively parallel computing systems will be necessary to solve computation intensive applications. The key bottleneck in massively parallel implementation of numerical algorithms is the synchronization of data across processing elements (PEs) after each iteration, which results in significant idle time. Thus, there is a trend towards relaxing the synchronization and adopting an asynchronous model of computation to reduce idle time. However, it is not clear what is the effect of this relaxation on the stability and accuracy of the numerical algorithm. In this paper we present a new framework to analyze such algorithms. We treat the computation in each PE as a dynamical system and model the asynchrony as stochastic switching. The overall system is then analyzed as a switched dynamical system. However, modeling of massively parallel numerical algorithms as switched dynamical systems results in a very large number of modes, which makes current analysis tools available for such systems computationally intractable. We develop new techniques that circumvent this scalability issue. The framework is presented on a one-dimensional heat equation as a case study for the partial differential equation (PDE), and the proposed analysis tools are verified by implementing asynchronous communications between cores on an nVIDIA Tesla™ GPU machine.
Axial crack propagation and arrest in pressurized fuselage

The rapid crack propagation, crack curving and arrest mechanisms associated with a pressurized, thin-walled ductile steel tubes are used to develop a model of axial rupture of an aircraft fuselage. This model is used to replicate axial crack propagation along a line of multi-site damage (MSD) and crack curving and arrest near a tear strap of an idealized fuselage.
Captive bodies: migrant kidnapping and deportation in Mexico

Kidnapping, originally considered a problem for the super wealthy, has quickly spread to epidemic proportions among the relative poor, especially among clandestine international migrants. This article examines how people's relationship to the US–Mexico border shapes their vulnerability to kidnapping. Moreover, through one long ethnographic vignette and survey data of deportees' experiences with kidnapping, this article explores how the border helps produce and shape kidnapping. By exploring the border as topological, based on the relationships created through clandestine migration and deportation, we can see how kidnapping operates to produce certain, highly varied subjectivities. Moreover, this article explores the contours of sexuality and masculinity for a feminist geopolitical take on some of the darkest chapters of the war on drugs in Mexico.
Computer Decision Support Changes Physician Practice But Not Knowledge Regarding Autism Spectrum Disorders

Objective: To examine whether adding an autism module promoting adherence to clinical guidelines to an existing computer decision support system (CDSS) changed physician knowledge and self-reported clinical practice. Methods: The CHICA (Child Health Improvement through Computer Automation) system, a CDSS, was enhanced with a module to improve management of autism in 2 of the 4 community pediatric clinics using the system. We examined the knowledge and beliefs of pediatric users using cross-sectional surveys administered at 3 time points (baseline, 12 months and 24 months post-implementation) between November 2010 and January 2013. Surveys measured knowledge, beliefs and self-reported practice patterns related to autism. Results: A total of 45, 39, and 42 pediatricians responded at each time point, respectively, a 95-100% response rate. Respondents’ knowledge of autism and perception of role for diagnosis did not vary between control and intervention groups either at baseline or any of the two post-intervention time points. At baseline, there was no difference between these groups in rates in the routine use of parent-rated screening instruments for autism. However, by 12 and 24 months post-implementation there was a significant difference between intervention and control clinics in terms of the intervention clinics consistently screening eligible patients with a validated autism tool. Physicians at all clinics reported ongoing challenges to community resources for further work-up and treatment related to autism. Conclusions: A CDSS module to improve primary care management of ASD in pediatric practice led to significant improvements in physician-reported use of validated screening tools to screen for ASDs. However it did not lead to corresponding changes in physician knowledge or attitudes.
Linking Teacher Quality, Student Attendance, and Student Achievement

Much research on the effectiveness of educational inputs, particularly research on teachers’ effectiveness, overlooks their potential impact on students’ character skills such as regular attendance. Using both nationally representative survey data and rich student-level administrative records from North Carolina I estimate classroom and teacher effects on primary school student absences in a value-added (VA) framework. Both datasets provide consistent evidence on three main findings. First, classrooms and teachers affect student absences. For example, replacing a teacher at the 25 th percentile of the teacher effectiveness distribution with one from the 75 th percentile is associated with a decrease of about 40% of a student absence standard deviation. Second, teachers who improve test scores do not necessarily improve student attendance, suggesting that effective teaching is multidimensional and that evaluating teachers along only one dimension will necessarily misclassify a nontrivial subset of teachers. Finally, I contribute to the methodological literature on VA modeling by providing evidence that VA measures of teacher effectiveness are insensitive to conditioning on student absences.
Towards a Symmetric Treatment of Satisfaction and Conflicts in Quantified Boolean Formula Evaluation

In this paper, we describe a new framework for evaluating Quantified Boolean Formulas (QBF). The new framework is based on the Davis-Putnam (DPLL) search algorithm. In existing DPLL based QBF algorithms, the problem database is represented in Conjunctive Normal Form (CNF) as a set of clauses, implications are generated from these clauses, and backtracking in the search tree is chronological. In this work, we augment the basic DPLL algorithm with conflict driven learning as well as satisfiability directed implication and learning. In addition to the traditional clause database, we add a cube database to the data structure. We show that cubes can be used to generate satisfiability directed implications similar to conflict directed implications generated by the clauses. We show that in a QBF setting, conflicting leaves and satisfying leaves of the search tree both provide valuable information to the solver in a symmetric way. We have implemented our algorithm in the new QBF solver Quaffle. Experimental results show that for some test cases, satisfiability directed implication and learning significantly prunes the search.
The distributional incidence of residential water and electricity subsidies

Subsidies to residential utility customers are popular among policymakers, utility managers, and utility customers alike, but they are nonetheless the subject of much controversy. Utility subsidies are seen as a way to help make utility service affordable for poor households and as an alternative mechanism for income redistribution. These arguments in favor of subsidies are countered by serious concerns about their adverse effects on consumer behavior, utility operations, and the financial health of utilities. Both the affordability and redistributive arguments for subsidies are based on the presumption that poor households benefit disproportionately from water and electricity subsidies, that they are well-targeted to the poor. The authors test this assumption by examining the extent to which the poor benefit from consumption and connection subsidies for water and electricity services. Their analysis of a wide range of subsidy models from around the developing world shows that the most common form of utility subsidy-quantity-based subsidies delivered through the tariff structure-are highly regressive. Geographically targeted or means-tested subsidies do better, and in many cases have a progressive incidence, but large numbers of poor households remain excluded. Low levels of coverage and metering severely limit the effectiveness of consumption subsidy schemes to reach the poor. Simulations suggest that connection subsidies are an attractive alternative for low coverage areas, but only if utilities have the means and motivation to extend network access to poor households and only if those households choose to connect.
Does money matter ? The effects of cash transfers on child health and development in rural Ecuador

This brief summarizes the results of a gender impact evaluation study, entitled Does money matter? : the effects of cash transfers on child health and development in rural Ecuador, conducted in 2003 in Ecuador. The study observed the impact of government-run cash transfer program targeted to poor mothers in rural Ecuador on the health and development of their children on the child level. Relatively modest unconditional cash transfers raised the hemoglobin levels of the poorest children, improved fine motor control, improved cognitive outcomes, and led to a reduction in reported behavioral problems. Program effects on cognitive development were generally larger for girls than boys, and for children with more highly-educated mothers but differences by child gender are not big, and are precisely estimated. The implied program effects are much larger than will be expected from the cross-sectional elasticities of outcomes with respect to expenditures for households in the control group. The findings suggest that these gains may have been accomplished though better nutrition and the use of de-worming medication, although not through the use of growth monitoring check-ups and better parenting. Funding for the study derived from the Center for Economic and Policy Studies at Princeton University, the Government of Ecuador, and The World Bank.
Antichaos in a class of random boolean cellular automata

Abstract A variant of Kauffman's model of cellular metabolism is presented. It is a randomly generated network of boolean gates, identical to Kauffman's except for a small bias in favor of boolean gates that depend on at most one input. The bias is asymptotic to 0 as the number of gates increases. Upper bounds on the time until the network reaches a state cycle and the size of the state cycle, as functions of the number of gates n, are derived. For any c >0, if the bias approaches 0 slowly enough, the state cycles will be smaller than nc.
An Efficient and Robust Ray-Box Intersection Algorithm

The computational bottleneck in a ray tracer using bounding volume hierarchies is often the ray intersection routine with axis-aligned bounding boxes. We describe a version of this routine that uses IEEE numerical properties to ensure that those tests are both robust and efficient. Sample source code is available online.
Capitalism and freedom

Abstract This essay tests Milton Friedman's conjecture that capitalism is a necessary condition for political freedom. For the decade around 2000 indices of the degree of capitalism and the degree of political freedom are highly correlated and provide plausibility for Friedman's conjecture. In looking at changes over time in the nineteenth century, however, the analysis refutes Friedman's conjecture. These apparently contradictory results are reconciled by showing that both capitalism and freedom are related to such variables as the educational level of the population so that, although not causally tied, they are correlated in a cross-national comparison.
Recent Developments in Understanding Two-dimensional Turbulence and the Nastrom–Gage Spectrum

Two-dimensional turbulence appears to be a more formidable problem than three-dimensional turbulence despite the numerical advantage of working with one less dimension. In the present paper we review recent numerical investigations of the phenomenology of two-dimensional turbulence as well as recent theoretical breakthroughs by various leading researchers. We also review efforts to reconcile the observed energy spectrum of the atmosphere (the Nastrom–Gage spectrum) with the predictions of two-dimensional turbulence and quasigeostrophic turbulence.
Performance Measure Aggregation, Career Incentives, and Explicit Incentives

ABSTRACT: We examine a setting in which managers have differential career concerns and firm performance is publicly observed using disaggregated measures that are incrementally informative but costly to contract upon. In such a setting, when do firms contract on aggregated rather than disaggregated performance measures? We show that at intermediate levels of managerial career concerns contracting on an aggregate measure can be welfare-enhancing. In this case, the net cost of both contracting directly on an aggregate measure and exploiting career incentives based on disaggregated measures is smaller than the cost of contracting directly on disaggregate measures. Our findings also imply that detailed performance disclosures will be accompanied by lower incentive weights based on aggregate performance when career incentives mitigate distortions caused by aggregation. Further, if performance measures become noisier due to transient shocks, we find that contractual incentive weights on aggregate performance ca...
The acute and chronic stimulatory effects of endothelin-1 on glucose transport are mediated by distinct pathways in 3T3-L1 adipocytes

We have recently shown that pretreatment with endothelin-1 (ET-1) for 20 min stimulates GLUT4 translocation in a PI3-kinasedependent manner in 3T3-L1 adipocytes (Imamura, T. et al., J Biol Chem 274:33691‐33695). This study presents another pathway by which ET-1 potentiates glucose transport in 3T3-L1 adipocytes. ET-1 treatment (10 nM) leads to approximately 2.5-fold stimulation of 2deoxyglucose (2-DOG) uptake within 20 min, reaching a maximal effect of ;4-fold at ;6 h, and recovering almost to basal levels after 24 h. Insulin treatment (3 ng/ml) results in an approximately 5-fold increase in 2-DOG uptake at 1 h, and recovering to basal levels after 24 h. The ETA receptor antagonist, BQ 610, inhibited ET-1 induced glucose uptake both at 20 min and 6 h, whereas the ETB receptor antagonist, BQ 788, was without effect. Interestingly, ET-1 stimulated 2-DOG uptake at 6 h, not at 20 min, was almost completely blocked by the protein-synthesis inhibitor, cycloheximide and the RNA-synthesis inhibitor, actinomycin D, suggesting that the shortterm (20 min) and long-term (6 h) effects of ET-1 involve distinct mechanisms. GLUT4 translocation assay showed that 20 min, but not 6 h, exposure to ET-1 led to GLUT4 translocation to the plasma membrane. In contrast, 6 h, but not 20 min, exposure to ET-1 increased expression of the GLUT1 protein, without affecting expression of GLUT4 protein. ET-1 induced 2-DOG uptake and GLUT1 expression at 6 h were completely inhibited by the MEK inhibitor, PD 98059, and partially inhibited by the PI3-kinase inhibitor, LY 294002, and the Gai inhibitor, pertussis toxin. The PLC inhibitor, U 73122, was without effect. These findings suggest that ET-1 induced GLUT1 protein expression is primarily mediated via MAPK, and partially via PI3K in 3T3-L1 adipocytes. (Endocrinology 141: 4623‐ 4628, 2000)
Packetized Video On MAGNET

Theoretical analysis of integrated local area network model of MAGNET, an integrated network testbed developed at Columbia University, shows that the bandwidth freed up during video and voice calls during periods of little movement in the images and periods of silence in the speech signals could be utilized efficiently for graphics and data transmission. Based on these investigations, an architecture supporting adaptive protocols that are dynamicaly controlled by the requirements of a fluctuating load and changing user environment has been advanced. To further analyze the behavior of the network, a real-time packetized video system has been implemented. This system is embedded in the real-time multimedia workstation EDDY, which integrates video, voice, and data traffic flows. Protocols supporting variable-bandwidth, fixed-quality packetized video transport are described in detail.
Rotation-invariant pattern recognition using optimum feature extraction

In this paper we consider the problem of detecting a target regardless of its orientation when it is known that the target must be from one of two classes. We assume significant random intraclass variability, a complication which requires techniques from statistical pattern recognition for amelioration. The Foley-Sammon transformation for selecting optimum features from random training samples is used to solve the problem.
Pattern-directed processing of knowledge from texts

A framework for viewing human text comprehension, memory, and recall is presented that assumes patterns of abstract conceptual relations are used to guide processing. These patterns consist of clusters of knowledge that encode prototypical co-occurrences of situations and events in narrative texts. The patterns are assumed to be a part of a person's world knowledge and can be activated during comprehension to build associations among multiple linguistic propositions in memory according to their higher-order conceptual relations. During text reproduction from memory, these patterns provide retrieval plans for recall and a mechanism for sophisticated "guessing" when retrieval fails. Some data from human text learning tasks are presented as evidence for these higher-order conceptual patterns. Several structural and processing properties of the model are evaluated in light of these data. It is argued that the proposed pattern-directed processing model could be successfully implemented in artificial intelligence systems to provide adaptive error-handling mechanisms such as those observed in human behavior.
Frictional properties of olivine at high temperature with applications to the strength and dynamics of the oceanic lithosphere

[1] Faulting and brittle deformation of mantle rocks occurs in many tectonic settings such as oceanic transform faults, oceanic detachment faults, subduction zones, and continental rifts. However, few data exist that directly explore the frictional properties of peridotite rocks. Improved constraints on the brittle deformation of peridotite is important for a more complete understanding of the rheological properties of the lithosphere. Furthermore, our comparatively detailed understanding of plastic deformation in olivine allows us to explore the possible role of thermally activated intracrystalline deformation mechanisms in macroscopically brittle processes. It has been hypothesized, and some experimental data indicate, that plastic yielding by dislocation glide (low temperature plasticity) determines the direct effect in the rate and state frictional constitutive formulation. Plastic flow may also have important implications for the blunting or necking at asperity contacts that influences the time and/or displacement dependent friction evolution effect and frictional healing. We present results from saw cut experiments on fine grained synthetic olivine fault gouge conducted in a gas-medium deformation apparatus in the temperature range of 400–1000°C with 100 MPa confining pressure. We conducted velocity stepping tests to explore the rate and temperature dependence of sliding stability. We also conducted slide-hold-slide experiments to investigate the time and temperature dependence of fault zone restrengthening (frictional healing). The mechanical data and microstructural observations allow us to explore the role of thermally activated processes in frictional sliding. The data indicate systematic temperature dependenceof rate and state variables that can be attributed to plastic yielding at grain to grain contacts. We explore the implications of such temperature dependent behavior for controlling the base of the seismogenic zone in the oceanic lithosphere, and we seek insight into possible mechanistic models for the interactions between fracture and flow that could lead to improved constraints on the strength of the lithosphere.
Predicting the size of the T-cell receptor and antibody combining region from consideration of efficient self-nonself discrimination

The binding of antibody to antigen or T-cell receptor to major histocompatibility complex-peptide complex requires that portions of the two structures have complementary shapes that can closely approach each other. The question that we address here is how large should the complementary regions on the two structures be. The interacting regions are by necessity roughly the same size. To estimate the size (number of contact residues) of an optimal receptor combining region, we assume that the immune system over evolutionary time has been presented with a large random set of foreign molecules that occur on common pathogens, which it must recognize, and a smaller random set of self-antigens to which it must fail to respond. Evolutionarily, the receptors and the molecular groups that the immune system recognizes as epitopes are imagined to have coevolved to maximize the probability that this task is performed. The probability of a receptor matching a random antigen is estimated from this condition. Using a simple model for receptor-ligand interaction, we estimate that the optimal size binding region on immunoglobulin or T-cell receptors will contain about 15 contact residues, in agreement with experimental observation.
On the Spectrum of Magnetohydrodynamic Turbulence

We propose a phenomenological model for incompressible magnetohydrodynamic turbulence. We argue that nonlinear-wave interaction weakens as the energy cascade proceeds to small scales; however, the anisotropy of fluctuations along the large-scale magnetic field increases, which makes turbulence strong at all scales. To explain the weakening of the interaction, we propose that small-scale fluctuations of the velocity and magnetic fields become increasingly dynamically aligned as their scale decreases, so that turbulent "eddies" become locally anisotropic in the plane perpendicular to the large-scale magnetic field. In the limit of weak anisotropy, that is, weak large-scale magnetic field, our model reproduces the Goldreich-Sridhar spectrum, while the limit of strong anisotropy, that is, strong large-scale magnetic field, corresponds to the Iroshnikov-Kraichnan scaling of the spectrum. This is in good agreement with recent numerical results.
Syntheses, structure, magnetism, and optical properties of the partially ordered quaternary interlanthanide sulfides PrLnYb2S6 (Ln=Tb, Dy)

Dark red single crystals of PrLnYb{sub 2}S{sub 6} (Ln=Pr/Yb, Tb, Dy) have been synthesized through the reactions of elemental rare earth metals and S using a Sb{sub 2}S{sub 3} flux at 1000 deg. C. These isotypic compounds adopt the F-Ln{sub 2}S{sub 3} three-dimensional open-channel structure type. Eight-coordinate Pr{sup 3+} ions sit in the channels that are constructed from three different edge-shared double chains running down the b-axis that contain Yb(1)S{sub 6} octahedra, Yb(2)S{sub 6} octahedra, and LnS{sub 7} monocapped trigonal prisms. Each double chain connects to four other neighbors by sharing vertices and edges. Considerable disordering in Ln positions was observed in single X-ray diffraction experiments only in the case of Pr/Yb. Least-squares refinements gave rise to the formulas of Pr{sub 1.34}Yb{sub 2.66}S{sub 6}, of PrTbYb{sub 2}S{sub 6}, and PrDyYb{sub 2}S{sub 6}, which are confirmed by the elemental analysis and magnetic susceptibility measurements. Pr{sub 1.34}Yb{sub 2.66}S{sub 6}, PrTbYb{sub 2}S{sub 6}, and PrDyYb{sub 2}S{sub 6} are paramagnetic down to 2 K, without any indications of long-range magnetic ordering. The optical transitions for Pr{sub 1.34}Yb{sub 2.66}S{sub 6}, PrTbYb{sub 2}S{sub 6}, and PrDyYb{sub 2}S{sub 6} are at approximately 1.6 eV. Crystallographic data are listed as an example for PrTbYb{sub 2}S{sub 6}: monoclinic, spacemore » group P2{sub 1}/m, a=10.9496(10) A, b=3.9429(4) A, c=11.2206(10) A, {beta}=108.525(2){sup o}, V=459.33(7) A{sup 3}, Z=2. - Graphical abstract: An illustration of the three-dimensional structure of PrTbYb{sub 2}S{sub 6} viewed along the b-axis.« less
Advances in NLTE modeling for integrated simulations

Abstract The last few years have seen significant progress in constructing the atomic models required for non-local thermodynamic equilibrium (NLTE) simulations. Along with this has come an increased understanding of the requirements for accurately modeling the ionization balance, energy content and radiative properties of different atomic species for a wide range of densities and temperatures. Much of this progress is the result of a series of workshops dedicated to comparing the results from different codes and computational approaches applied to a series of test problems. The results of these workshops emphasized the importance of atomic model completeness, especially in doubly-excited states and autoionization transitions, to calculating ionization balance, and the importance of accurate, detailed atomic data to producing reliable spectra. We describe a simple screened-hydrogenic model that calculates NLTE ionization balance with sufficient accuracy, at a low enough computational cost for routine use in radiation-hydrodynamics codes. The model incorporates term splitting, Δn = 0 transitions, and approximate UTA widths for spectral calculations, with results comparable to those of much more detailed codes. Simulations done with this model have been increasingly successful at matching experimental data for laser-driven systems and hohlraums. Accurate and efficient atomic models are just one requirement for integrated NLTE simulations. Coupling the atomic kinetics to hydrodynamics and radiation transport constrains both discretizations and algorithms to retain energy conservation, accuracy and stability. In particular, the strong coupling between radiation and populations can require either very short time steps or significantly modified radiation transport algorithms to account for NLTE material response. Considerations such as these continue to provide challenges for NLTE simulations.
CP violation in a multi higgs doublet model

We study CP violation in a multi-Higgs doublet model based on aS 3×Z 3 horizontal symmetry. We consider two mechanisms for CP violation in this model: a) CP violation due to complex Yukawa couplings; and b) CP violation due to scalarpseudoscalar mixings. We find that the predictions for e′/e, CP violation in B decays and the electric dipole moments of neutron and electron are different between these two mechanisms. These predictions are also dramatically different from the minimal Standard Model predictions.
Synthesis and characterization of a new macrobicyclic (Cryptand) siderophore containing three endocyclic hydroxamate donor groups

Abstract The first trishydroxamate cryptand ligand was synthesized by tripodal coupling of a tris acid chloride and a tris O-benzylhydroxylamine. The spectrophotometric properties of its Fe(III) complex were investigated and compared with those of desferriferrioxamine B. Its 1:1 Ga(III) complex was also prepared and characterized.
Film dosimetry: Linearisation of dose-response for relative measurements of dose distribution

The authors have demonstrated a practical method to transform the densitometer readings to a quantity (apparent dose) that linearises the dose-response curve for the Kodak XV-2 film for all conditions used (different energies, irradiation geometries and processing). The determination of the constants for the pair film-densitometer has to be done only once, using a set of conditions chosen as reference. The linearisation method proposed permits relative film dosimetry, in the same film, without any calibration. Beam profiles (electrons or photons) obtained in several depths in a single film (parallel geometry), can be used to obtain the isodose chart, for a given field size. Only central axis depth dose data for the particular field is additionally required. Treatment plan systems can usually use these data as input to generate isodose charts.
Tai Chi research review

This review briefly summarizes recent Tai Chi research on physical benefits including balance and muscle strength and psychological benefits including attentiveness, sleep and anxiety. Cardiovascular changes following Tai Chi include decreased heart rate and blood pressure, increased vagal activity and decreased cholesterol. Pain syndromes that have been affected include fibromyalgia, osteoarthritis and rheumatoid arthritis. Autoimmune and immune conditions recently researched and reviewed here include osteoporosis, diabetes and HIV. Methodological problems with this research include the variability in forms (series of postures) used across studies as well as the intensity of the Tai Chi schedule. Further, most of the studies are based on within group changes rather than attention control group comparisons. Nonetheless, significant clinical improvements have been noted.
The Delayed Formation of Dwarf Galaxies

One of the largest uncertainties in understanding the effect of a background UV field on galaxy formation is the intensity and evolution of the radiation field with redshift. This work attempts to shed light on this issue by computing the quasi-hydrostatic equilibrium states of gas in spherically symmetric dark matter halos (roughly corresponding to dwarf galaxies) as a function of the amplitude of the background UV field. We integrate the full equations of radiative transfer, heating, cooling, and nonequilibrium chemistry for nine species: H, H+, H-, H2, H+2, He, He+, He++, and e-. As the amplitude of the UV background is decreased, the gas in the core of the dwarf goes through three stages characterized by the predominance of ionized (H+), neutral (H), and molecular (H2) hydrogen. Characterizing the gas state of a dwarf galaxy with the radiation field allows us to estimate its behavior for a variety of models of the background UV flux. Our results indicate that a typical radiation field can easily delay the collapse of gas in halos corresponding to 1 σ cold dark matter perturbations with circular velocities of less than 30 km s-1.
Systematic Review: An Evaluation of Major Commercial Weight Loss Programs in the United States

This review describes the characteristics, costs, and effectiveness of major weight loss programs that provide in-person or Internet-based counseling.
Self-assembled dinuclear cobalt(II)-salen catalyst through hydrogen-bonding and its application to enantioselective nitro-aldol (Henry) reaction.

Novel chiral dinuclear Co(II)-salen catalysts self-assembled through the pyridone/aminopyridine hydrogen-bonding pair have been developed. The self-assembled dinuclear Co(II)-Salen catalyst results in significant rate acceleration (48 times faster rate) as well as excellent enantioselectivity (96% ee vs 55% ee) in a nitro-aldol reaction, compared to the corresponding monomeric catalyst. A bimetallic mechanism is suggested by the kinetic experiment showing that the rate law is second order in [catalyst]. The self-assembly through hydrogen bonding was confirmed by X-ray structure and by the 1H experiments revealing that the dimerization constant of the novel hydrogen-bonding capable salen ligand in 25% v/v CD3NO2/CDCl3 is 53 ± 21 M−1. This result proves the validity of self-assembly based approaches toward the efficient construction of chiral bimetallic catalyst system.
Stoichiometric hydrogenation of α,β-unsaturated ketones by HCo(CO)4

Abstract A study of the kinetics of the stoichiometric hydrogenation of α,β-unsaturated ketones by HCo(CO) 4 led to the rate expression rate  k obs [ketone][HCo(CO) 4 ] 4 −[CO] − . The reaction is catalyzed by Co 2 (CO) 8 and shows a small inverse isotope effect with DCo(CO) 4 . Although the analogous reaction with the α-β-unsaturated ester dimethyl α-methylidenesuccinate (dimethyl itaconate, DMI) is also catalyzed by Co 2 (CO) 8 and also shows an inverse isotope effect, the rate expression involves a first order dependence on HCo(CO) 4 . Furthermore, contrary to the behavior of simple acrylates, which have been shown elsewhere to conform to the same kinetic expression, no aldehydic product is produced. A mechanism consistent with the results is proposed.
Atomic scale characterization of oxygen vacancy segregation at SrTiO 3 grain boundaries

We have examined the atomic structure, composition, and bonding at a nominally undoped 58° [001] tilt grain boundary in SrTiO3 in order to develop an understanding of the control that the grain boundary plane exerts over the bulk properties. Room temperature and in situ heating experiments show that there is a segregation of oxygen vacancies to the grain boundary that is increased at elevated temperatures and is independent of the cation arrangement. These measurements provide direct support for recent experimental and theoretical predictions that nonstoichiometry, and in particular oxygen vacancies, are responsible for the widely observed grain boundary properties.
Diels-Alder approach to biaryls (DAB): importance of the ortho-nitro moiety in the [4 + 2] cycloaddition.

A series of nitrophenyl acetylenes were evaluated for their utility in a cycloaddition–cycloreversion approach to polysubstituted biaryls. ortho-Nitrophenyl acetylene consistently provided the target biaryls in superior yields as compared to the meta and paranitro substituted variants.
Access to Electron‐Rich Arene‐Fused Hexahydroquinolizinones through a Gold‐Catalysis‐Initiated Cascade Process

Golden Cascade: With a tethered, electron-rich arene as the internal nucleophile, a gold-catalyzed amide cyclization to an alkyne initiates a cascade process that ends with a Ferrier rearrangement. Electron-rich arene-bearing hexahydroquinolizin-2-ones are formed in good yields and can be converted into indole alkaloids in only a few steps.
Comparison of the Unbalance Responses of Jeffcott Rotors With Shaft Bow and Shaft Runout

The unbalance response of a Jeffcott rotor with shaft bow and/or runout was theoretically and experimentally studied. Included in the theoretical model is the capability of low-speed response compensation, such that the response at low speed can be vectorially subtracted from the total response at any rotational speed. Responses of rotors with equal amounts of bow or runout are shown to be significantly different in both Bode and Nyquist forms. A small scale lightly damped Jeffcott rotor rig was also tested. The magnitude and angular position of the shaft bow were parametrically varied. The vibration data from the rotor tests were plotted using a synchronous tracking filter by two methods: both not using and using low speed 15 refs.
TREE: An interactive system for editing tree structures

Abstract Many existing systems provide extensive facilities for entry and manipulation of text. Typical of these are QED (Bell Telephone), TECO (MIT), TVEDIT (Stanford), and E (Yale). Text entry, insertion, deletion, search, and display are all performed interactively with a small number of key strokes. Unfortunately, similarly powerful and general interactive tools for editing of more general data structures have not been available. The system TREE provides these interactive editing facilities for tree structures. TREE enables insertion, deletion, copying, search, and display of any branch of a given tree structure. Any tree, whether a syntax tree or a decision tree, or a LISP program could be entered rapidly and changed quickly in TREE. The program itself is coded in PDP 10 fortran IV and will run with any of a number of inexpensive graphics terminals.
p¯-p Elastic and Charge Exchange Scattering at About 120 Mev

Observation of antiproton--proton collisions in a propane bubble chamber at an average energy of 120 Mev has been accomplished. The ratio of antiprotons to other particles in the beam has been increased by utilizing the differential rate of momentum loss in absorbers between antiprotons and other particles. The angular distribution of 33 p-p scattering events between 15 and 165 deg c.m. is presented. (W.D.M.)
Optical coherence tomography imaging and fluorescence spectroscopy of a novel rat model of ovarian cancer

Ovarian cancer is relatively rare but is the fifth leading cause of death from cancer in women. Little is known about the precursors and early stages of ovarian cancer partially due to the lack of a realistic animal model. A cohesive model that incorporates ovarian cancer induction into a menopausal rodent would be well suited for comprehensive studies of ovarian cancer, and non-destructive imaging would allow carcinogenesis to be followed. Optical Coherence Tomography (OCT) and Light-Induced Fluorescence (LIF) are minimally invasive optical modalities that allow both structural and biochemical changes to be noted. Rat ovaries were exposed to 4-vinylcyclohexene diepoxide (VCD) for 20 days in order to destroy the primordial follicles. Sutures coated with 7,12-dimethylbenz(a)anthracene (DMBA) were implanted in the right ovary, in order to produce epithelial based ovarian cancers. Rats were sacrificed at 1, 3, and 5 months and ovaries were harvested and imaged with a combined OCT/LIF system. Histology was preformed on the harvested ovaries and any pathology determined. OCT was able to visualize follicle loss and DMBA-induced abnormalities. LIF spectra were also different between cycling, follicle deplete, and DMBA-exposed ovaries. Overall this pilot study demonstrated the feasibility of both the animal model and optical imaging.
Helium Synthesis, Neutrino Flavors, and Cosmological Implications

The problem of the production of helium in the big bang is reexamined in the light of several recent astrophysical observations. These data, and theoretical particle-physics considerations, lead to some important inconsistencies in the standard big-bang model and suggest that a more complicated picture is needed. Thus, recent constraints on the number of neutrino flavors, as well as constraints on the mean density (openness) of the universe, need not be valid.
Arousal Increases Social Transmission of Information

Social transmission is everywhere. Friends talk about restaurants, policy wonks rant about legislation, analysts trade stock tips, neighbors gossip, and teens chitchat. Further, such interpersonal communication affects everything from decision making and well-being (Asch, 1956; Mehl, Vazire, Holleran, & Clark, 2010) to the spread of ideas, the persistence of stereotypes, and the diffusion of culture (Heath, 1996; Heath, Bell, & Sternberg, 2001; Kashima, 2008; Schaller, Conway, & Tanchuk, 2002; Schaller & Crandall, 2004). But although it is clear that social transmission is both frequent and important, what drives people to share, and why are some stories and information shared more than others?
Alternative routes in road networks

We study the problem of finding good alternative routes in road networks. We look for routes that are substantially different from the shortest path, have small stretch, and are locally optimal. We formally define the problem of finding alternative routes with a single via vertex, develop efficient algorithms for it, and evaluate them experimentally. Our algorithms are efficient enough for practical use and compare favorably with previous methods in both speed and solution quality.
Prior experience affects amodal completion in pigeons

In a three-alternative forced-choice task, 4 pigeons were trained to discriminate a target stimulus consisting of two colored shapes, one of which partially occluded the other, from two foil stimuli that portrayed either a complete or an incomplete version of the occluded shape. The dependent measure was the percentage of total errors that the birds committed to the complete foil. At the outset of training, the pigeons committed approximately 50% of total errors to the complete foil, but as training progressed, the percentage of errors to the complete foil rose. When the pigeons were given a second exposure to the initial set of stimuli, they committed 70% of total errors to the complete foil, suggesting that they now saw the complete foil as more similar to the occluded target than the incomplete foil. These results suggest that experience with 2-D images may facilitate amodal completion in pigeons, perhaps via perceptual learning.
100 Years of Weight Loss Surgery: Voluntary Weight Loss, Involuntary Bone Loss

In the past 100 years, there have been myriad medical discoveries—giant steps—from Louis Pasteur’s germ theory, to the understanding of gut physiology and metabolic processes—that are the essential underpinnings of modern day medicine. The beginnings of surgery to promote weight loss, now known as bariatric surgery, date back to the 1880s when it was noted that gut resections resulted in weight loss. It was not long afterward that articles started to appear documenting nutritional “disturbances” and the patient’s likelihood of survival based upon the location and the length of bowel removed. Numerous articles have been penned citing the first bariatric surgeries, but to date, there has not been a comprehensive look back at the origins of the science as well as the severe metabolic complications that furthered understanding, prompted innovative medical and surgical approaches, and ultimately led to modern day practice. This article endeavors to do exactly that. Intestinal bypass surgeries to treat obesity are here to stay. Some of the most profound complications of intestinal bypass manifest in the skeleton and include skeletal demineralization, hyperoxaluria, nephrolithiasis, and fractures. Much has been done to further elucidate the underlying mechanisms, identify preventive strategies, and implement practice guidelines, but this patient population remains at increased risk for metabolic bone disease.
A Simple Example of ¿Quantum Darwinism¿: Redundant Information Storage in Many-Spin Environments

As quantum information science approaches the goal of constructing quantum computers, understanding loss of information through decoherence becomes increasingly important. The information about a system that can be obtained from its environment can facilitate quantum control and error correction. Moreover, observers gain most of their information indirectly, by monitoring (primarily photon) environments of the “objects of interest.” Exactly how this information is inscribed in the environment is essential for the emergence of “the classical” from the quantum substrate. In this paper, we examine how many-qubit (or many-spin) environments can store information about a single system. The information lost to the environment can be stored redundantly, or it can be encoded in entangled modes of the environment. We go on to show that randomly chosen states of the environment almost always encode the information so that an observer must capture a majority of the environment to deduce the system’s state. Conversely, in the states produced by a typical decoherence process, information about a particular observable of the system is stored redundantly. This selective proliferation of “the fittest information” (known as Quantum Darwinism) plays a key role in choosing the preferred, effectively classical observables of macroscopic systems. The developing appreciation that the environment functions not just as a garbage dump, but as a communication channel, is extending our understanding of the environment’s role in the quantum-classical transition beyond the traditional paradigm of decoherence.