cssi/SciSciGPT-SciSciNet huggingface dataset:
Estimating the import content of Argentine exports

Despite recent efforts toward collecting evidence of vertical specialization for developed economies, scarce work has been dedicated to developing economies and to Argentina, in particular. The key contribution of this paper is to provide comparable estimates of vertical specialization as reflected in the imported content of exports in Argentina. Drawing on the 1997 input-output matrix for Argentina, the authors estimate that the imported content of the countrys exports is about 14.5 percent of total exports, lower than for other emerging economies. They also provide estimates of imported content for more disaggregated product categories.
Why the Middle East is Economically Underdeveloped: Historical Mechanisms of Institutional Stagnation

Amillennium ago, around roughly the tenth century, the Middle East was an economically advanced region of the world, as measured by standard of living, technology, agricultural productivity, literacy or institutional creativity. Only China might have been even more developed. Subsequently, however, the Middle East failed to match the institutional transformation through which western Europe vastly increased its capacity to pool resources, coordinate productive activities and conduct exchanges. True, the institutional endowment of the Middle East continued to evolve. But in certain areas central to economic modernization change was minimal, at least in relation to the structural transformation of the West and, for that matter, the Middle East’s own evolution during the early Islamic centuries. In eighteenth-century Cairo, credit practices hardly differed from those of the tenth century. Likewise, investors and traders were using enterprise forms essentially identical to those prevalent eight centuries earlier. By the nineteenth century, the entire Middle East was clearly “underdeveloped” relative to western Europe and its offshoots in the new world; and by the twenty-first century, it had fallen markedly behind parts of the Far East as well. This essay offers reasons why the Middle East became underdeveloped. In particular, it points to certain Middle Eastern institutions, including ones rooted in the region’s dominant religion, as past and in some cases also continuing obstacles to economic development. The institutions that generated evolutionary bottlenecks include: 1) the Islamic law of inheritance, which inhibited capital accumulation; 2) the strict individualism of Islamic law and its lack of a concept of corporation, which hindered organizational development and contributed to keeping civil society weak; and 3) the waqf, Islam’s distinct form of trust, which locked vast
The Relationship between Employee Involvement and Workplace Dispute Resolution

This paper examines the relationship between employee involvement programs and workplace dispute resolution using data from the Workplace and Employee Survey (WES) conducted by Statistics Canada. The results provide support for a link between employee involvement and lower grievance rates in unionized workplaces. This link existed for establishments in both the goods and service sectors, but the practices involved differed between industrial sectors. By contrast, in nonunion workplaces, results of the analysis provided support for a link between the adoption of employee involvement programs and formal grievance procedures, but not between employee involvement and lower grievance rates.
Guaranteeing Spoof-Resilient Multi-Robot Networks

Multi-robot networks use wireless communication to provide wide-ranging services such as aerial surveillance and unmanned delivery. However, effective coordination between multiple robots requires trust, making them particularly vulnerable to cyber-attacks. Specifically, such networks can be gravely disrupted by the Sybil attack, where even a single malicious robot can spoof a large number of fake clients. This paper proposes a new solution to defend against the Sybil attack, without requiring expensive cryptographic key-distribution. Our core contribution is a novel algorithm implemented on commercial Wi-Fi radios that can “sense” spoofers using the physics of wireless signals. We derive theoretical guarantees on how this algorithm bounds the impact of the Sybil Attack on a broad class of multi-robot problems, including locational coverage and unmanned delivery. We experimentally validate our claims using a team of AscTec quadrotor servers and iRobot Create ground clients, and demonstrate spoofer detection rates over 96%.
Assembly plan from observation

We have been developing a novel programming method, the assembly-plan-from-observation (APO) method. A human performs assembly operations in front of a TV camera. The APO system observes the human assembly actions, understands the actions, and generates robot programs to enable a robot arm to repeat the same assembly operations. This paper overviews our current activities on the APO project.
Speckle Imaging with the Papa Detector and the Knox-Thompson Algorithm

The speckle imaging program at the CfA has developed a set of tools for the implementation of speckle image reconstruction and has applied these tools to a wide range of scientific programs. Two key elements in this program have been the development of a 2-dimensional photon counting camera, the PAPA detector, and the implementation of image reconstruction procedures using the Knox-Thompson algorithm. This paper discusses the current status of the PAPA detector and the details of our data processing methods and numerical algorithms.
Geodesics in CAT(0) cubical complexes

We describe an algorithm to compute the geodesics in an arbitrary CAT(0) cubical complex. A key tool is a correspondence between cubical complexes of global non-positive curvature and posets with inconsistent pairs. This correspondence also gives an explicit realization of such a complex as the state complex of a reconfigurable system, and a way to embed any interval in the integer lattice cubing of its dimension.
Estimation and Reconstruction from Aberrated Amplitude Interferometer Measurements

Several methods are proposed for estimating samples of the Fourier modulus from aberrated, low-light level amplitude interferometer measurements. The mean-squared error and bias of these estimators are compared. A phase retrieval algorithm which can be used to reconstruct an image of the object intensity from the estimated Fourier modulus samples is then discussed.
Walter Baade’s Discovery of the Two Stellar Populations

Walter Baade was born one hundred and one years ago; he died in 1960, a third of a century ago. In my opinion he was the second most important observational astronomer of this century, after Edwin Hubble, who changed our place in the universe and our perception of it. I will give some of the evidence in this paper.
A curved beam test specimen for determining the interlaminar tensile strength of a laminated composite

A curved beam type of test specimen is evaluated for use in determining the through-the-thickness strength of laminated composites. Two variations of a curved beam specimen configuration (semicircular and elliptical) were tested to failure using static and fatigue loads. The static failure load for the semicircular specimens was found to be highly sensitive to flaw content, with the specimens falling into two distinct groups. This result supports the use of proof testing for structural validation. Static design allowables are derived based on the Weibull distribution. Fatigue data indicates no measured increase in specimen compliance prior to final fracture. All static and fatigue failures at room temperature dry conditions occurred catastrophically. The elliptical specimens demonstrated unusually high failure strengths indicating the presence of phenomena requiring further study. Results are also included for specimens exposed to a wet environment showing a matrix strength degradation due to moisture content. Further testing is underway to evaluate a fatigue methodology for matrix dominated failures based on residual static strength (wearout).
Geophysical evolution of the Themis family parent body

[1] We model the geophysical evolution of the Themis family parent body. This study is motivated by the recent detection of water ice at the surface of 24 Themis, the first detection of free water on the surface of an asteroid. The Themis family members display a variety of spectral properties and densities, a possible indication that their parent was differentiated at the time of break-up. Differentiation of the parent body is better explained if it accreted as a mixture of ice within a few My after the production of CAIs. From these models we highlight a number of issues that provide a strong rationale for further ground-based and future space exploration of that family.
Clouds and climate change

As concern grows over the possibility of altering the Earth's climate, a major uncertainty exists in computer models used to study the Earth's atmosphere, regarding our current understanding of clouds and our ability to simulate their effect on climate. A number of recent observations and computer simulation studies, however, have shed light on the important role of clouds in determining the present and future climate of our atmosphere. Data from the National Aeronautics and Space Administration's (NASA's) Earth Radiation Budget Experiment have been used to obtain an accurate picture of how clouds affect our present global climate system [Ramanathan, 1989]. The effect of clouds on solar and thermal radiation entering and leaving our climate is known as cloud forcing. Low clouds generally cool the Earth's surface, while high clouds warm the climate system. For the entire planet, however, the cooling effect of low clouds is stronger than the warming effect from high clouds, so that overall, clouds cool the climate.
Rules of thumb for information acquisition from large and redundant data

We develop an abstract model of information acquisition from redundant data. We assume a random sampling process from data which contain information with bias and are interested in the fraction of information we expect to learn as function of (i) the sampled fraction (recall) and (ii) varying bias of information (redundancy distributions). We develop two rules of thumb with varying robustness. We first show that, when information bias follows a Zipf distribution, the 80-20 rule or Pareto principle does surprisingly not hold, and we rather expect to learn less than 40% of the information when randomly sampling 20% of the overall data. We then analytically prove that for large data sets, randomized sampling from power-law distributions leads to "truncated distributions" with the same power-law exponent. This second rule is very robust and also holds for distributions that deviate substantially from a strict power law. We further give one particular family of powerlaw functions that remain completely invariant under sampling. Finally, we validate our model with two large Web data sets: link distributions to web domains and tag distributions on delicious.com.
On sets of integers which contain no three terms in geometric progression

The problem of looking for subsets of the natural numbers which contain no 3-term arithmetic progressions has a rich history. Roth's theorem famously shows that any such subset cannot have positive upper density. In contrast, Rankin in 1960 suggested looking at subsets without three-term geometric progressions, and constructed such a subset with density about 0.719. More recently, several authors have found upper bounds for the upper density of such sets. We significantly improve upon these bounds, and demonstrate a method of constructing sets with a greater upper density than Rankin's set. This construction is optimal in the sense that our method gives a way of effectively computing the greatest possible upper density of a geometric-progression-free set. We also show that geometric progressions in Z/nZ behave more like Roth's theorem in that one cannot take any fixed positive proportion of the integers modulo a sufficiently large value of n while avoiding geometric progressions.
Approximate maximum flow on separable undirected graphs

We present faster algorithms for approximate maximum flow in undirected graphs with good separator structures, such as bounded genus, minor free, and geometric graphs. Given such a graph with n vertices, m edges along with a recursive √n-vertex separator structure, our algorithm finds an 1 -- e approximate maximum flow in time O(m6/5poly(e--1)), ignoring poly-logarithmic terms. Similar speedups are also achieved for separable graphs with larger size separators albeit with larger run times. These bounds also apply to image problems in two and three dimensions.Key to our algorithm is an intermediate problem that we term grouped L2 flow, which exists between maximum flows and electrical flows. Our algorithm also makes use of spectral vertex sparsifiers in order to remove vertices while preserving the energy dissipation of electrical flows. We also give faster spectral vertex sparsification algorithms on well separated graphs, which may be of independent interest.
How to shift bias: Lessons from the baldwin effect

An inductive learning algorithm takes a set of data as input and generates a hypothesis as output. A set of data is typically consistent with an infinite number of hypotheses; therefore, there must be factors other than the data that determine the output of the learning algorithm. In machine learning, these other factors are called the bias of the learner. Classical learning algorithms have a fixed bias, implicit in their design. Recently developed learning algorithms dynamically adjust their bias as they search for a hypothesis. Algorithms that shift bias in this manner are not as well understood as classical algorithms. In this paper, we show that the Baldwin effect has implications for the design and analysis of bias shifting algorithms. The Baldwin effect was proposed in 1896 to explain how phenomena that might appear to require Lamarckian evolution (inheritance of acquired characteristics) can arise from purely Darwinian evolution. Hinton and Nowlan presented a computational model of the Baldwin effect in 1987. We explore a variation on their model, which we constructed explicitly to illustrate the lessons that the Baldwin effect has for research in bias shifting algorithms. The main lesson is that it appears that a good strategy for shift of bias in a learning algorithm is to begin with a weak bias and gradually shift to a strong bias.
Atmospheric stabilization of CO2 emissions : near-term reductions and intensity-based targets

This study analyzes CO2 emissions reduction targets for various countries and geopolitical regions by the year 2030 in order to stabilize atmospheric concentrations of CO2 at the level of 450 ppm (550 ppm including non CO2 greenhouse gases). It also determines CO2 intensity cuts that would be needed in those countries and regions if the emission reductions were achieved through intensity-based targets while assuming no effect on forecasted economic growth. Considering that the stabilization of CO2 concentrations at 450 ppm requires the global trend of CO2 emissions to reverse before 2030, this study develops two scenarios: reversing the global CO2 trend in (i) 2020 and (ii) 2025. The study shows that global CO2 emissions would be 42 percent above the 1990 level in 2030 if the increasing trend of global CO2 emissions is reversed by 2020. If reversing the trend is delayed by 5 years, the 2030 global CO2 emissions would be 52 percent higher than the 1990 level. The study also finds that to achieve these targets while maintaining assumed economic growth, the global average CO2 intensity would require a 68 percent drop from the 1990 level or a 60 percent drop from the 2004 level by 2030.
Vector bundles with infinitely many souls

We construct the first examples of manifolds, the simplest one being S^3 x S^4 x R^5, which admit infinitely many complete nonnegatively curved metrics with pairwise nonhomeomorphic souls.
Single-nucleon experiments

We discuss the Jefferson Lab low momentum transfer data on moments of the nucleon spin structure functions $g_1$ and $g_2$ and on single charged pion electroproduction off polarized proton and polarized neutron. A wealth of data is now available, while more is being analyzed or expected to be taken in the upcoming years. Given the low momentum transfer selected by the experiments, these data can be compared to calculations from Chiral Perturbation theory, the effective theory of strong force that should describe it at low momentum transfer. The data on various moments and the respective calculations do not consistently agree. In particular, experimental data for higher moments disagree with the calculations.The absence of contribution from the $$\Delta$$ resonance in the various observables was expected to facilitate the calculations and hence make the theory predictions either more robust or valid over a larger $Q^2$ range. Such expectation is verified only for the Bjorken sum, but not for other observables in which the $$\Delta$$ is suppressed. Preliminary results on pion electroproduction off polarized nucleons are also presented and compared to phenomenological models for which contributions from different resonances are varied. Chiral Perturbation calculations of these observables, while not yet available, would be valuable and, together with these data, would provide an extensive test of the effective theory.
Multi-layer floorplanning for reconfigurable designs

Partial dynamic reconfiguration is an emerging area in field programmable gate arrays (FPGA) designs, which is used for saving device area and cost. In order to reduce the reconfiguration overhead, two consecutive similar sub-designs should be placed in the same locations to get the maximum reuse of common components. This requires that all the future designs be considered while floorplanning for any given design. A comprehensive framework for floorplanning designs on partial reconfigurable architecture is provided. Several reconfiguration-specific floorplanning cost functions and moves that aim to reduce the reconfiguration overhead are introduced. A new multi-layer sequence pair-representation-based floorplanner that allows overlap of static and non-static components of multiple designs and guarantees a feasible overlapping floorplan with minimal area packing is introduced. A new matching algorithm that covers all possible matchings of static blocks during floorplanning for multiple designs is presented. In our experiments, it is shown that the proposed floorplanner gives more than 50% savings in reconfiguration frames compared with the scheme where no reuse is done. Further, compared with a traditional sequential floorplanner, our floorplanner removes infeasibility in many designs, achieves an improvement of clock period by 12% on average and reduces the place and route time significantly. The proposed floorplanner could be used for finding high-quality floorplans for applications that use partial reconfiguration.
Finite time blow up for a Navier-Stokes like equation

The final version of this paper appears in: "Proceedings of the American Mathematical Society" 129 (2001): 3017-3023. Print.
The size of the jet launching region in M87

The supermassive black hole candidate at the centre of M87 drives an ultra-relativistic jet visible on kiloparsec scales, and its large mass and relative proximity allow for event horizon scale imaging with very long baseline interferometry at millimetre wavelengths (mm-VLBI). Recently, relativistic magnetohydrodynamic simulations of black hole accretion flows have proven capable of launching magnetically dominated jets. We construct time-dependent disc/jet models of the innermost portion of the M87 nucleus by performing relativistic radiative transfer calculations from one such simulation. We identify two types of models, jet-dominated or disc/jet, that can explain the spectral properties of M87, and use them to make predictions for current and future mm-VLBI observations. The Gaussian source size for the favoured sky orientation and inclination from observations of the large-scale jet is as (≃4–6 Schwarzschild radii) on current mm-VLBI telescopes, very similar to existing observations of Sgr A*. The black hole shadow, direct evidence for an event horizon, should be visible in future measurements using baselines between Hawaii and Mexico. Both models exhibit variability at millimetre wavelengths with factor of ≃2 amplitudes on year time-scales. For the low inclination of M87, the counter-jet dominates the event horizon scale millimetre wavelength emission from the jet-forming region.
Training Deep Fourier Neural Networks to Fit Time-Series Data

We present a method for training a deep neural network containing sinusoidal activation functions to fit to time-series data. Weights are initialized using a fast Fourier transform, then trained with regularization to improve generalization. A simple dynamic parameter tuning method is employed to adjust both the learning rate and regularization term, such that stability and efficient training are both achieved. We show how deeper layers can be utilized to model the observed sequence using a sparser set of sinusoid units, and how non-uniform regularization can improve generalization by promoting the shifting of weight toward simpler units. The method is demonstrated with time-series problems to show that it leads to effective extrapolation of nonlinear trends.
Interaction as a Framework for Modeling

The irreducibility of interactive to algorithmic computing requires fundamental questions concerning models of computation to be reexamined. This paper reviews single-stream and multiple-stream interaction machines, extensions of set theory and algebra for models of sequential interaction, and interactive extensions of the Turing test. It motivates the use of interactive models as a basis for applications to computer architecture, software engineering, and artificial intelligence.
Providing resource information to users of a national computing center

The Texas Advanced Computing Center provides a variety of high-end resources to state, national, and international computational scientists and engineers. Many users obtain information about these resources via the Texas Advanced Computing Center user interfaces, which are supported by an information gathering and distribution infrastructure. After a number of years of use, we needed to improve our user interfaces by both redesigning the web interface and adding mobile interfaces. To support this, we also needed to update our information infrastructure. This paper presents our new design, describes how it improves over the previous approach, and shows that this design meets our current and expected future needs. Copyright © 2014 John Wiley & Sons, Ltd.
Palladium-catalyzed direct β-arylation of ketones with diaryliodonium salts: a stoichiometric heavy metal-free and user-friendly approach

We herein report a new protocol for the Pd-catalyzed β-arylation of ketones without stoichiometric heavy metals. Widely accessible diaryliodonium salts are used as both the oxidant and aryl source. This tandem redox catalysis merges ketone dehydrogenation and conjugate addition without an additional oxidant or reductant. This transformation features the use of a unique bis-N-tosylsulfilimine ligand and the combination of potassium trifluoroacetate/trifluoroacetic acid to maintain an appropriate acidity of the reaction medium. The reaction tolerates both air and moisture, and shows a broad substrate scope. Kinetics studies, along with filtration and poisoning tests, support the involvement of palladium nanoparticles in the catalysis.
Massive datasets in astronomy

Astronomy has a long history of acquiring, systematizing, and interpreting large quantities of data. Starting from the earliest sky atlases through the first major photographic sky surveys of the 20th century, this tradition is continuing today, and at an ever increasing rate.Like many other fields, astronomy has become a very data-rich science, driven by the advances in telescope, detector, and computer technology. Numerous large digital sky surveys and archives already exist, with information content measured in multiple Terabytes, and even larger, multi-Petabyte data sets are on the horizon. Systematic observations of the sky, over a range of wavelengths, are becoming the primary source of astronomical data. Numerical simulations are also producing comparable volumes of information. Data mining promises to both make the scientific utilization of these data sets more effective and more complete, and to open completely new avenues of astronomical research.Technological problems range from the issues of database design and federation, to data mining and advanced visualization, leading to a new toolkit for astronomical research. This is similar to challenges encountered in other data-intensive fields today.These advances are now being organized through a concept of the Virtual Observatories, federations of data archives and services representing a new information infrastructure for astronomy of the 21st century. In this article, we provide an overview of some of the major datasets in astronomy, discuss different techniques used for archiving data, and conclude with a discussion of the future of massive datasets in astronomy.
On some dyadic models of the Euler equations

Katz and Pavlovic recently proposed a dyadic model of the Euler equations for which they proved finite time blow-up in the H 3/2+∈ Sobolev norm. It is shown that their model can be reduced to a dyadic model of the inviscid Burgers equation. The inviscid Burgers equation exhibits finite time blow-up in H α , for a > 1/2, but its dyadic restriction is even more singular, exhibiting blow-up for any α > 0. Friedlander and Pavlovic developed a closely related model for which they also prove finite time blow-up in H 3/2+∈ . Some inconsistent assumptions in the construction of their model are outlined. Finite time blow-up in the H α norm, for any a > 0, is proven for a class of models that includes all those models. An alternative shell model of the Navier-Stokes equations is discussed.
Hydrogen bond catalyzed enantioselective vinylogous Mukaiyama aldol reaction.

The concept of hydrogen bonding catalysis was extended to the vinylogous Mukaiyama aldol reaction, which gives rapid access to polyketide derivatives. The reaction of the silyldienol ether shown and a range of aldehydes catalyzed by TADDOL proceeds regiospecifically to produce the addition products in good yields and enantiomeric excesses.
Increasing FTIR spectromicroscopy speed and resolution through compressive imaging

Abstract At the Advanced Light Source at Lawrence Berkeley National Laboratory, we are investigating how to increase both the speed and resolution of synchrotron infrared imaging. Synchrotron infrared beamlines have diffraction-limited spot sizes and high signal to noise, however spectral images must be obtained one point at a time and the spatial resolution is limited by the effects of diffraction. One technique to assist in speeding up spectral image acquisition is described here and uses compressive imaging algorithms. Compressive imaging can potentially attain resolutions higher than allowed by diffraction and/or can acquire spectral images without having to measure every spatial point individually thus increasing the speed of such maps. Here we present and discuss initial tests of compressive imaging techniques performed with ALS Beamline 1.4.3’s Nic-Plan infrared microscope, Beamline 1.4.4 Continuum XL IR microscope, and also with a stand-alone Nicolet Nexus 470 FTIR spectrometer.
Extending the Empathic Communication Model of Burnout: Incorporating Individual Differences to Learn More about Workplace Emotion, Communicative Responsiveness, and Burnout

This field study contributes to the literature on emotional communication in the human-services industry. Specifically, this study extends the empathic communication model of burnout by incorporating individual differences to predict workplace emotion and communicative responsiveness. This extension has important implications for both research and knowledge on responsiveness, burnout, and workplace practices. A questionnaire filled out by 159 caregivers from a moderately sized human-services agency explored the role of self-monitoring and emotional intelligence in enhancing caregiver performance. Results indicate that those caregivers who can control their expressive behavior and manage their moods to maintain a sense of optimism are in a better position to respond emotionally and communicatively to distressed clients and resist job burnout.
A note on the composition product of symmetric sequences

We consider the composition product of symmetric sequences in the case where the underlying symmetric monoidal structure does not commute with coproducts. Even though this composition product is not a monoidal structure on symmetric sequences, it has enough structure, namely that of a ‘normal oplax’ monoidal product, to be able to define monoids (which are then operads on the underlying category) and make a bar construction. The main benefit of this work is in the dual setting, where it allows us to define a cobar construction for cooperads.
Condensation reactions of guanidines with bis-electrophiles: Formation of highly nitrogenous heterocycles

2-Amino-1,4-dihydropyrimidines were reacted with bis-electrophiles to produce novel fused bi-pyrimidine, pyrimido-aminotriazine, and pyrimido-sulfonamide scaffolds. In addition, a quinazoline library was constructed using a guanidine Atwal-Biginelli reaction with 1-(quinazolin-2-yl)guanidines. The product heterocycles have novel constitutions with high nitrogen atom counts and represent valuable additions to screening libraries for the discovery of new modulators of biological targets.
Analysis of daily latitude variations

The daily latitude measurements of the International polar motion service are analyzed. The results indicate that the annual polar oscillation is probably due to local phenomena with amplitudes varying from 0.05 to 0.15 min. Within the resolution of the residuals (150 cm), there is no indication of the sharp changes which might be associated with earthquake effects. Then, applying Schuster's test to a periodogram of the residuals indicates that there are probably several processes occurring at amplitudes between 0.007 and 0.03 min whose solution awaits a more precise measurement technique.
A Detection of Bright Features in the Microwave Background

We report the characterization of bright, compact features in the cosmic microwave background radiation (CMBR) detected during the 1992 June and 1994 June balloon flights of the Medium-Scale Anisotropy Measurement. Spectral flux density is determined at 5.7, 9.3, and 16.5 cm-1. No viable counterparts are found in source catalogs at 5 GHz or at 100 μm. The measured spectrum is consistent with a temperature fluctuation in the CMBR. The existence of such features is consistent with adiabatic fluctuation models of anisotropy in the CMBR.
RosettaEPR: an integrated tool for protein structure determination from sparse EPR data.

Site-directed spin labeling electron paramagnetic resonance (SDSL-EPR) is often used for the structural characterization of proteins that elude other techniques, such as X-ray crystallography and nuclear magnetic resonance (NMR). However, high-resolution structures are difficult to obtain due to uncertainty in the spin label location and sparseness of experimental data. Here, we introduce RosettaEPR, which has been designed to improve de novo high-resolution protein structure prediction using sparse SDSL-EPR distance data. The "motion-on-a-cone" spin label model is converted into a knowledge-based potential, which was implemented as a scoring term in Rosetta. RosettaEPR increased the fractions of correctly folded models ( [Formula: see text] <7.5A) and models accurate at medium resolution ( [Formula: see text] <3.5A) by 25%. The correlation of score and model quality increased from 0.42 when using no restraints to 0.51 when using bounded restraints and again to 0.62 when using RosettaEPR. This allowed for the selection of accurate models by score. After full-atom refinement, RosettaEPR yielded a 1.7A model of T4-lysozyme, thus indicating that atomic detail models can be achieved by combining sparse EPR data with Rosetta. While these results indicate RosettaEPR's potential utility in high-resolution protein structure prediction, they are based on a single example. In order to affirm the method's general performance, it must be tested on a larger and more versatile dataset of proteins.
Instabilities and oscillations in isotropic active gels

We present a generic formulation of the continuum elasticity of an isotropic crosslinked active gel. The gel is described by a two-component model consisting of an elastic network coupled frictionally to a permeating fluid. Activity is induced by active crosslinkers that undergo an ATP-activated cycle and transmit forces to the network. The on/off dynamics of the active crosslinkers is described via rate equations for unbound and bound motors. For large activity motors yield a contractile instability of the network. At intermediate activity, the on/off motor dynamics provides an effective inertial drag on the network that opposes elastic restoring forces, resulting in spontaneous oscillations. Our work provides a continuum formulation that unifies earlier microscopic models of oscillations in muscle sarcomeres and a generic framework for the description of the large scale properties of isotropic active solids.
CO (J = 4→3) and [C I] Observations of the Carina Molecular Cloud Complex

We present large-area, fully sampled maps of the Carina molecular cloud complex in the CO (J = 4→3) and neutral carbon [C I] 3P1 → 3P0 transitions. These data were obtained using the 1.7 m Antarctic Submillimeter Telescope and Remote Observatory (AST/RO). The maps cover an area of approximately 3 deg2 with a uniform 1' spatial sampling. Analysis of these data, in conjunction with CO (J = 1→0) data from the Columbia CO survey and the IRAS HIRES continuum maps for the same region, suggests that the spiral density wave shock associated with the Carina spiral arm may be playing an important role in the formation and dissociation of the cloud complex, as well as in maintaining the internal energy balance of the clouds in this region. Massive stars form at the densest regions of the molecular cloud complex. The winds and outflows associated with these stars have a disrupting effect on the complex and inject mechanical energy into the parent clouds, while the UV radiation from the young stars also heats the parent clouds. The present set of data suggests, however, that massive stars alone may not account for the energetics of the clouds in the Carina region. The details of the data and the correlation among the various data sets hint at the possible role that the spiral density wave shock plays in feeding interstellar turbulence and heating molecular clouds.
Hospitalists and the doctor-patient relationship.

Abstract Hospitalists—physicians whose practice focuses on the care of hospitalized general medicine patients—are increasingly common in the United States, often displacing primary care physicians from this role. While advocates of hospitalists point to evidence of cost reduction and perhaps improved short‐run outcomes, critics question whether costs or long‐run outcomes are improved and whether there may be insidious effects on the doctor‐patient relationship. I define a framework for addressing these questions, assess the available evidence, and identify a research agenda to better understand the implications of the hospitalist movement for the doctor‐patient relationship. Using a framework that emphasizes general and patient‐specific knowledge as crucial to a successful doctor‐patient relationship, I argue that the success of the hospitalist model will depend on its ability to continue to develop its areas of technical expertise while ensuring care that is both continuous and appropriate to the needs a...
Emergency ultrasound fellowship training: a novel team-based approach.

OBJECTIVES To describe our experience with implementation of a novel team-based emergency ultrasound (EUS) fellowship training program. METHODS We conducted a retrospective review at an academic medical center. All emergency department (ED) faculty and residents were divided into 3 teams, and a fellow was assigned to each team. Each fellow was responsible for ultrasound (US) education of their team members and faculty credentialing. Additionally, each fellow was assigned to one of these specific responsibilities every month: (1) education, (2) quality assurance/billing, and (3) equipment. The fellows also received a checklist at the beginning of the fellowship training, which outlined research, reading, teaching, and scanning requirements. RESULTS With a team-based approach, all US examinations were reviewed for quality control within 1 week after the scans were performed. The number of US examinations billed by faculty increased by 180%. The US billing revenue increased by 60% during the study period. Fifteen additional faculty members were credentialed to use US in the ED. Compliance with bedside documentation of US findings increased from 30% to 90%. There was increased resident engagement, and the number of scans performed by residents increased by 130%. There was also a substantial decrease in the funds required to replace damaged transducers. CONCLUSIONS A team-based EUS fellowship training program had a substantial impact on US use in the ED, quality control review, faculty credentialing, US billing revenue, compliance with documentation, and resident US education.
Round Turbulent Thermals, Puffs, Starting Plumes and Starting Jets in Uniform Crossflow

The self-preserving properties of round turbulent thermals, puffs, starting plumes and starting jets, in unstratified and uniform crossflow, were investigated experimentally. The experiments involved dye-containing fresh water (for nonbuoyant flows) and salt water (for buoyant flows) sources injected vertically downward into crosflowing fresh water within a water channel. Time-resolved video images of the flows were obtained using CCD cameras. Experimental conditions were as follows: source exit diameters of 3.2 and 6.4 mm, source Reynolds numbers of 2,500-16,000, source/ambient velocity ratios of 4-35, source/ambient density ratios (for buoyant flows) of 1.073 and 1.150, volumes of injected source fluid (for thermals and puffs) comprising 16-318 source diameters, streamwise (vertical) penetration distances of 0-200 source diameters and 0-13 Morton length scales (for buoyant flows) and crosstream (horizontal) penetration distances of 0-620 source diameters
The crust and uppermost mantle structure of Southern Peru from ambient noise and earthquake surface wave analysis

Abstract Southern Peru is located in the northern Central Andes, which is the highest plateau along an active subduction zone. In this region, the Nazca slab changes from normal to flat subduction, with the associated Holocene volcanism ceasing above the flat subduction regime. We use 6 s to 67 s period surface wave signals from ambient noise cross-correlations and earthquake data, to image the shear wave velocity ( V S V ) structure to a depth of 140 km. A mid-crust low-velocity zone is revealed, and is interpreted as partially molten rocks that are part of the Andean low-velocity zone. It is oblique to the present trench, and possibly indicates the location of the volcanic arcs formed during the steepening of the Oligocene flat slab beneath the Altiplano plateau. The recently subducted slab beneath the forearc shows a decrease in velocity from the normal to flat subduction regime that might be related to hydration during the formation of the Nazca ridge, which in turn may contribute to the buoyancy of the flat slab. The mantle above the flat slab has a comparatively high velocity, which indicates the lack of melting and thus explains the cessation of the volcanism above. A velocity contrast from crust to uppermost mantle is imaged across the Cusco–Vilcanota Fault System, and is interpreted as the boundary between two lithospheric blocks.
Migration of marrow stromal cells in response to sustained release of stromal-derived factor-1α from poly(lactide ethylene oxide fumarate) hydrogels

Stromal derived factor-1alpha (SDF-1alpha) is an important chemokine in stem cell trafficking and plays a critical role in the homing of bone marrow stromal (BMS) cells. However, its use in tissue regeneration is limited by its relatively short half-life and the time-dependent nature of cell homing to the site of injury. The objective of this work was to investigate the release characteristics of SDF-1alpha from degradable poly(lactide ethylene oxide fumarate) (PLEOF) hydrogels and to determine the effect of sustained release of SDF-1alpha on migration of BMS cells. Three PLEOF hydrogels with poly(l-lactide) (PLA) fractions of 6%, 9%, and 24% by weight were synthesized. After the addition of chemokine, the polymerizing mixture was crosslinked to produce SDF-1alpha loaded PLEOF hydrogels. The hydrogels were characterized with respect to sol fraction, water uptake, degradation, SDF-1alpha loading efficiency and release kinetics, and migration rate of bone marrow stromal (BMS) cells. The more hydrophilic hydrogels with 6% and 9% PLA fraction had a pronounced burst release followed by a period of sustained release by diffusion for 21 days. The more hydrophobic hydrogel with 24% PLA fraction had a less pronounced burst release and displayed a slow but constant release by diffusion between days 1 and 9 followed by a fast release by diffusion-degradation from days 9 to 18. The fraction of active SDF-1alpha released from 6%, 9%, and 24% hydrogels after 21 days was 34.3%, 32.3%, and 35.8%, respectively. The migration of BMS cells in response to time-released SDF-1alpha closely followed the protein release kinetics from the hydrogels. The biodegradable PLEOF hydrogel may potentially be useful as a delivery matrix for sustained release of SDF-1alpha in the proliferative phase of healing for recruitment of progenitor cells in tissue engineering applications.
The Role of Private Decentralized Institutions in Sustaining Industry Self-Regulation

An emerging body of institutional scholarship emphasizes the role played by private decentralized institutions in facilitating collective action among organizations. However, these institutions often suffer from free riding and opportunism. This may lead firms to exit the institution and eventually cause its collapse. In this paper, we explore how private decentralized institutions may be sustained despite these problems. We focus on one form of private decentralized institution---trade association--sponsored industry self-regulatory programs. We advance two alternative hypotheses to explain the sustained existence of industry self-regulatory institutions: (a) Firms participate to gain a participation-contingent benefit, and (b) firms participate to maintain a generally beneficial institution. Using a 10-year panel of data from the chemical industry, we find evidence consistent with the latter hypothesis for at least one prominent example of self-regulation. Our findings have implications for both specific models of industry self-regulation and general theories of collective action.
A Reduced-Order Model for Evaluating the Effect of Rotational Speed on the Natural Frequencies and Mode Shapes of Blades

A reduced-order model has been developed that can be used to accurately and quickly calculate the changes in the natural frequencies and mode shapes of a blade that are caused by centrifugal stiffening, It has been corroborated by comparisons with finite element analyses of a cantilevered tapered plate and with frequencies from a low aspect ratio fan blade.
MESOCELLULAR SILICEOUS FOAMS WITH UNIFORMLY SIZED CELLS AND WINDOWS

Molecular sieves with uniform large pores are desirable for chemical reactions and for use in separations involving large molecules.1 Periodic cubic and hexagonal mesoporous silica phases with uniform large pores have been synthesized by using nonionic triblock and star diblock copolymers as templates.2 Control over the pore size is achieved by adjusting the hydrophobic volumes of the self-assembled aggregates.2,3 In this paper, we describe how adding a sufficiently large amount of an organic cosolvent induces a phase transformation from the highly ordered p6mm mesostructure of SBA-15-type mesoporous silicas to remarkable mesostructured cellular foams (mesocellular foams, MCFs) composed of uniformly sized, large spherical cells that are interconnected by uniform windows to create a continuous 3-D pore system. The interconnected nature of the large uniform pores makes these new mesostructured silicas promising candidates for supports for catalysts and in separations involving large molecules, and they may be of interest in low-dielectric applications. The MCFs have been synthesized in aqueous acid by using dilute Pluronic P123 solutions in the presence of 1,3,5-trimethylbenzene (TMB) as organic cosolvent.4 X-ray diffraction (XRD) experiments5 reveal well-resolved peaks at small angles, as shown in Figure 1 for a sample with a cell diameter of 33 nm. Careful analyses of the scattering data for MCFs show that the higher order peaks cannot be indexed to any plane or space group (e.g., p6mm) or to a lamellar diffraction pattern. In fact, after subtraction of the background,6 the X-ray data are in good agreement with simulated scattering7 due to monodisperse spheres (cells) of diameter D (see Table 1), while attempts to fit the X-ray data to
Syndrome of hemolysis, elevated liver enzymes, and low platelet count: A severe consequence of hypertension in pregnancy

Data are presented to define a unique group of preeclamptic/eclamptic patients with the finding of hemolysis (H), elevated liver enzymes (EL), and a low platelet count (LP). This entity has been termed the HELLP syndrome and may occur when the usual clinical findings to diagnose severe preeclampsia are absent. Often the patient is given a nonobstetric diagnosis and treatment is withheld or modified. The possible pathophysiology of this syndrome, the management of the patient, and the maternal and neonatal outcomes are presented. Recognition of the clinical and laboratory findings of the HELLP syndrome is important if early, aggressive therapy is to be initiated to prevent maternal and neonatal death. The practicing obstetrician must be knowledgeable about this severe consequence of hypertension in pregnancy.
Generalized safety first and the planting of crops

This article adapts a modern shortfall-based portfolio selection rule developed by Stutzer (2000) and Haley and Whiteman (2008) to the farm manager's land allocation problem. The approach provides a useful normative model of land allocation that obviates distributional assumptions and expected utility specifications, and one that selects an optimal allocation that weighs skewness and other higher order moments in addition to mean and variance. This is of particular interest because crop returns often exhibit skewness, which is not accounted for by traditional Mean-Variance (MV)-based approaches. The rule is demonstrated using the data from Lence and Hart (1997).
The Bel?Robinson tensor for topologically massive gravity

We construct, and establish the (covariant) conservation of, a 4-index 'super stress tensor' for topologically massive gravity. Separately, we discuss its invalidity in quadratic curvature models and suggest a generalization.