cssi/SciSciGPT-SciSciNet huggingface dataset:
LDPC code design for noncoherent physical layer network coding

This work considers optimizing LDPC codes in the physical-layer network coded two-way relay channel using noncoherent FSK modulation. The error-rate performance of channel decoding at the relay node during the multiple-access phase was improved through EXIT-based optimization of Tanner graph variable node degree distributions. Codes drawn from the DVB-S2 and WiMAX standards were used as a basis for design and performance comparison. The computational complexity characteristics of the standard codes were preserved in the optimized codes by maintaining the extended irregular repeat-accumulate (eIRA). The relay receiver performance was optimized considering two modulation orders M = {4; 8} using iterative decoding in which the decoder and demodulator refine channel estimates by exchanging information. The code optimization procedure yielded unique optimized codes for each case of modulation order and available channel state information. Performance of the standard and optimized codes were measured using Monte Carlo simulation in the flat Rayleigh fading channel, and error rate improvements up to 1:2 dB are demonstrated depending on system parameters.
Mars Double-Flyby Free Returns

A subset of Earth-originating Mars double-flyby ballistic trajectories is documented. The subset consists of those trajectories that, after the first Mars flyby, perform a half-revolution transfer with Mars before returning to Earth. This class of free returns is useful for both human and robotic Mars missions because of its low geocentric energy at departure and arrival, and because of its extended stay time in the vicinity of Mars. Ballistic opportunities are documented over Earth departure dates ranging from 2015 through 2100. The mission is viable over three or four consecutive Mars synodic periods and unavailable for the next four, with the pattern repeating approximately every 15 years. Over the remainder of the century, a minimum Earth departure hyperbolic excess speed of 3.16 km/s, a minimum Earth atmospheric entry speed of 11.47 km/s, and a minimum flight time of 904 days are observed. The algorithm used to construct these trajectories is presented along with several examples.
Authorization in CORBA Security

Integration of security and object-oriented techniques is critical for the successful deployment of distributed object systems. The CORBA Security services, first published in December of 1995 by the Object Management Group, is a detailed specification of how to handle security in object systems that conform to the Object Management Architecture. This article provides a rigorous definition of the authorization part of CORBA Security. Its semantics is given in terms of an access control matrix. The dependencies among the authorization elements are analyzed and possible interpretations for access control decision functions are given. The expressivity of the authorization model to define a wide range of policies, in particular mandatory access control, is discussed.
A genetic algorithm based global search strategy for population pharmacokinetic/pharmacodynamic model selection.

The current algorithm for selecting a population pharmacokinetic/pharmacodynamic model is based on the well-established forward addition/backward elimination method. A central strength of this approach is the opportunity for a modeller to continuously examine the data and postulate new hypotheses to explain observed biases. This algorithm has served the modelling community well, but the model selection process has essentially remained unchanged for the last 30 years. During this time, more robust approaches to model selection have been made feasible by new technology and dramatic increases in computation speed. We review these methods, with emphasis on genetic algorithm approaches and discuss the role these methods may play in population pharmacokinetic/pharmacodynamic model selection.
Public Finance and Economic Development

This chapter will analyze the interrelationships of public finance and economic development. The following aspects of public finance will be considered: the budget deficit (or surplus), the size of the public sector, and public investment. Apart from the financing of the budget deficit, the chapter will examine its possible effects on various economic variables. The relationship between the size of the government budget and economic growth will also be analyzed. Finally, the impact of public investment on private investment, total investment, and economic growth will be investigated.
A Life in New Drug Research

Originally printed in Brit J Pharmacol 2010; 160 (Suppl. 1) S15–S25, doi 10.1111/j.1476-5381.2010.00848.x Please use the original publication for reference purposes
Virasoro conformal blocks in closed form

Virasoro conformal blocks are fixed in principle by symmetry, but a closed-form expression is unknown in the general case. In this work, we provide two new closed-form expansions for the four-point Virasoro blocks on the sphere, for arbitrary operator dimensions and central charge c. We do so by solving known recursion relations. One representation is a sum over hypergeometric global blocks, whose coefficients we provide at arbitrary level. The other is a sum over semiclassical Virasoro blocks obtained in the limit in which two external operator dimensions scale linearly with large c. In both cases, the 1/c expansion of the Virasoro blocks is easily extracted. We discuss applications of these expansions to entanglement and thermality in conformal field theories and particle scattering in three-dimensional quantum gravity.
Biopsy Proven Medullary Sponge Kidney: Clinical Findings, Histopathology, and Role of Osteogenesis in Stone and Plaque Formation

Medullary sponge kidney (MSK) is associated with recurrent stone formation, but the clinical phenotype is unclear because patients with other disorders may be incorrectly labeled MSK. We studied 12 patients with histologic findings pathognomonic of MSK. All patients had an endoscopically recognizable pattern of papillary malformation, which may be segmental or diffuse. Affected papillae are enlarged and billowy, due to markedly enlarged inner medullary collecting ducts (IMCD), which contain small, mobile ductal stones. Patients had frequent dilation of Bellini ducts, with occasional mineral plugs. Stones may form over white (Randall's) plaque, but most renal pelvic stones are not attached, and have a similar morphology as ductal stones, which are a mixture of calcium oxalate and apatite. Patients had no abnormalities of urinary acidification or acid excretion; the most frequent metabolic abnormality was idiopathic hypercalciuria. Although both Runx2 and Osterix are expressed in papillae of MSK patients, no mineral deposition was seen at the sites of gene expression, arguing against a role of these genes in this process. Similar studies in idiopathic calcium stone formers showed no expression of these genes at sites of Randall's plaque. The most likely mechanism for stone formation in MSK appears to be crystallization due to urinary stasis in dilated IMCD with subsequent passage of ductal stones into the renal pelvis where they may serve as nuclei for stone formation.
Modeling failure priors and persistence in model-based diagnosis

Probabilistic model-based diagnosis computes the posterior probabilities of failure of components from the prior probabilities of component failure and observations of system behavior. One problem with this method is that such priors are almost never directly available. One of the reasons is that the prior probability estimates include an implicit notion of a time interval over which they are specified - for example, if the probability of failure of a component is 0.05, is this over the period of a day or is this over a week? A second problem facing probabilistic model-based diagnosis is the modeling of persistence. Say we have an observation about a system at time t1 and then another observation at a later time t2. To compute posterior probabilities that take into account both the observations, we need some model of how the state of the system changes from time t1 to t2. In this paper, we address these problems using techniques from Reliability theory. We show how to compute the failure prior of a component from an empirical measure of its reliability - the Mean Time Between Failure (MTBF). We also develop a scheme to model persistence when handling multiple time tagged observations.
US Telecommunications Today, October 2002

This paper examines the current conditions in the US telecommunications sector (October 2002). We examine the impact of technological and regulatory change on market structure and business strategy. Among others, we discuss the emergence and decline of the telecom bubble, the impact on pricing of digitization and the emergence of Internet telephony. We briefly examine the impact of the 1996 Telecommunications Act on market structure and strategy in conjunction with the history of regulation and antitrust intervention in the telecommunications sector. After discussing the impact of wireless technologies, we conclude by venturing into some short term predictions. We express concern about the derailment of the implementation of the 1996 Act by the aggressive legal tactics of the entrenched monopolists (the local exchange carriers), and we point to the real danger that the intent of Congress in passing the 1996 Act to promote competition in telecommunications will not be realized. We also discuss the wave of mergers in the Telecommunications and cable industries.
A Simple Linear Ranking Algorithm Using Query Dependent Intercept Variables

The LETOR website contains three information retrieval datasets used as a benchmark for testing machine learning ideas for ranking. Participating algorithms are measured using standard IR ranking measures (NDCG, precision, MAP). Similarly to other participating algorithms, we train a linear classifier. In contrast, we define an additional free benchmark variable for each query. This allows expressing the fact that results for different queries are incomparable for the purpose of determining relevance. The results are slightly better yet significantly simpler than the reported participating algorithms.
Identity statuses in upper-division physics students

We use the theories of identity statuses and communities of practice to describe three different case studies of students finding their paths through undergraduate physics and developing a physics subject-specific identity. Each case study demonstrates a unique path that reinforces the link between the theories of communities of practice and identity statuses. The case studies also illustrate how students progress and regress in their commitment to their subject-specific identities and their professional identities. The progression/regression is dependent on their willingness to explore different aspects of a physics professional identity and their availability to carry out such exploration. Identity status and future identity crises can manifest in students’ behavior in the classroom. Allowing students to engage in more legitimate practices of the physics community, especially in the form of undergraduate research, helps students to explore their opportunities and inform the level of commitment they wish to make to physics.
Evidence Absorption and Propagation through Evidence Reversals

The arc reversal/node reduction approach to probabilistic inference is extended to include the case of instantiated evidence by an operation called “evidence reversal.” This not only provides a technique for computing posterior joint distributions on general belief networks, but also provides insight into the methods of Pearl [1986b] and Lauritzen and Spiegelhalter [1988]. Although it is well understood that the latter two algorithms are closely related, in fact all three algorithms are identical whenever the belief network is a forest.
Transversity and Meson Photoproduction

Both meson photoproduction and semi-inclusive deep inelastic scattering can potentially probe transversity in the nucleon. We explore how that potential can be realized dynamically. The role of rescattering in both exclusive and inclusive meson production as a source for transverse polarization asymmetry is examined. We use a dynamical model to calculate the asymmetry and relate that to the transversity distribution of the nucleon.
High-efficiency solar concentrator

A new type of solar concentrator is presented using liquid lenses and simple translational tracking mechanism. The concentrator achieves a 100:1 nominal concentration ratio and is compared in performance with a flat-plate collector having two sheets of glazing and non-selective coating. The results of the thermal analysis show that higher temperatures can be obtained with the concentrator than is possible with the non-concentrator flat-plate type. Furthermore, the thermal efficiency far exceeds that of the comparative flat-plate type for all operating conditions.
Microcanonical Action and the Entropy of a Rotating Black Hole

The authors have recently proposed a “microcanonical functional integral” representation of the density of quantum states of the gravitational field. The phase of this real-time functional integral is determined by a “microcanonical” or Jacobi action, the extrema of which are classical solutions at fixed total energy, not at fixed total time interval as in Hamilton’s action. This approach is fully general but is especially well suited to gravitating systems because for them the total energy can be fixed simply as a boundary condition on the gravitational field. In this paper we describe how to obtain Jacobi’s action for general relativity. We evaluate it for a certain complex metric associated with a rotating black hole and discuss the relation of the result to the density of states and to the entropy of the black hole.
The Limits to Dollarization in Ecuador: Lessons from Argentina

The paper draws lessons from the failed Argentine experience with convertibility to highlight the dangers of dollarization in Ecuador. Argentinas currency peg to the US dollar was successful in reducing inflation but given the overvalued real exchange rate, created burgeoning twin deficits and a chronic dependency on foreign capital. Ecuador too suffers from chronic current account imbalance. In contrast to Argentina, Ecuador seems to be relying on remittance income to close its external financing gap. Though perhaps this model is less unstable than that of relying on foreign capital it is no more sustainable. The paper closes with a realistic critique of thisdevelopment strategy.
Essential surfaces in highly twisted link complements

We prove that in the complement of a highly twisted link, all closed, essential, meridionally incompressible surfaces must have high genus. The genus bound is proportional to the number of crossings per twist region. A similar result holds for surfaces with meridional boundary: such a surface either has large negative Euler characteristic or is an n‐punctured sphere visible in the diagram. 57M25, 57M50 topological and geometric information directly from link diagrams has proved to be a difficult task. Historically, alternating links are one of the few classes of links for which this information has been accessible. For instance, links with prime alternating diagrams contain no incompressible tori by work of Menasco [12] and have minimalgenus Seifert surfaces constructible directly from the diagram by work of Crowell [4] and Murasugi [13]. The goal of this paper is to extend results in this vein to diagrams with a high degree of twisting. To state our results, we must define what this means. A bigon in a link diagram D.K/ is a disk in the projection plane whose boundary consists of two arcs in the projection of K. Define an equivalence relation on crossings in a diagram in which two crossings are considered equivalent if they are connected by a string of one or more consecutive bigons. Then a twist region of a diagram is an equivalence class of crossings. The minimal number of crossings in a twist region of D.K/ is called the height of D, denoted h.D/, and the number of twist regions of D.K/ is called the twist number, denoted t.D/. The height and twist number of a diagram turn out to be deeply related to the geometric structure of the link it depicts. Lackenby [11] showed that given a prime alternating diagram, the hyperbolic volume of the link complement is bounded both above and below by linear functions of the twist number t.D/. Futer, Kalfagianni and Purcell [6]
Some Convolution Identities and an Inverse Relation Involving Partial Bell Polynomials

We prove an inverse relation and a family of convolution formulas involving partial Bell polynomials. Known and some presumably new combinatorial identities of convolution type are discussed. Our approach relies on an interesting multinomial formula for the binomial coefficients. The inverse relation is deduced from a parametrization of suitable identities that facilitate dealing with nested compositions of partial Bell polynomials.
Optrix: Energy aware cross layer routing using convex optimization in wireless sensor networks

Energy minimization is of great importance in wireless sensor networks in extending the battery lifetime. One of the key activities of nodes in a WSN is communication and the routing of their data to a centralized base-station or sink. Routing using the shortest path to the sink is not the best solution since it will cause nodes along this path to fail prematurely. We propose a cross-layer energy efficient routing protocol Optrix that utilizes a convex formulation to maximize the lifetime of the network as a whole. We further propose, Optrix-BW, a novel convex formulation with bandwidth constraint that allows the channel conditions to be accounted for in routing. By considering this key channel parameter we demonstrate that Optrix-BW is capable of congestion control. Optrix is implemented in TinyOS, and we demonstrate that a relatively large topology of 40 nodes can converge to within 91 % of the optimal routing solution. We describe the pitfalls and issues related with utilizing a continuous form technique such as convex optimization with discrete packet based communication systems as found in WSNs. We propose a routing controller mechanism that allows for this transformation. We compare Optrix against the Collection Tree Protocol (CTP) and we found that Optrix performs better in terms of convergence to an optimal routing solution, for load balancing and network lifetime maximization than CTP.
Do Parents Have the Legal Authority to Consent to the Surgical Amputation of Normal, Healthy Tissue From Their Infant Children?: The Practice of Circumcision in the United States

The circumcision of infant males in the United States consists of the surgical amputation of normal, healthy tissue. In most cases, the procedure is performed at the parents' discretion, without any compelling medical or religious purpose. Recent medical studies and statements by many leading medical groups affirm that routine circumcision is medically unnecessary and potentially detrimental to the health of the male infant. A review of Supreme Court decisions reveals a dawning recognition of a minor's constitutional right to bodily integrity, as well as a readiness to curtail parental discretion in medical decision making for minors. Courts, acting under the parens patriae power of the state, have utilized the "substituted judgment" doctrine or the closely related "best interest" test in protecting the constitutional rights of incompetents and minors in cases involving sterilization or amputation. The application of this doctrine or test to the routine practice of infant circumcision would nullify parental consent to the procedure in all cases absent a showing of medical necessity. Although similar conclusions are embedded in international law and the federal Criminalization of Female Genital Mutilation Act with regard to female genital surgery, there is currently no equal protection against routine circumcision provided to infant males. The justification for this gender-based classification does not meet the "exceedingly persuasive" standard of constitutional review and is the focus of legal efforts to incorporate males under the protection of the Act. Neutral application of an amended Act which provides equal protection to males and females would be constitutional, even though it would restrict circumcision as a religious practice.
Dimension Extractors and Optimal Decompression

A dimension extractor is an algorithm designed to increase the effective dimension—i.e., the amount of computational randomness—of an infinite binary sequence, in order to turn a “partially random” sequence into a “more random” sequence. Extractors are exhibited for various effective dimensions, including constructive, computable, space-bounded, time-bounded, and finite-state dimension. Using similar techniques, the Kucera-Gacs theorem is examined from the perspective of decompression, by showing that every infinite sequence S is Turing reducible to a Martin-Lof random sequence R such that the asymptotic number of bits of R needed to compute n bits of S, divided by n, is precisely the constructive dimension of S, which is shown to be the optimal ratio of query bits to computed bits achievable with Turing reductions. The extractors and decompressors that are developed lead directly to new characterizations of some effective dimensions in terms of optimal decompression by Turing reductions.
Adaptive Submodularity: A New Approach to Active Learning and Stochastic Optimization.

Solving stochastic optimization problems under partial observability, where one needs to adaptively make decisions with uncertain outcomes, is a fundamental but notoriously difficult challenge. In this paper, we introduce the concept of adaptive submodularity, generalizing submodular set functions to adaptive policies. We prove that if a problem satisfies this property, a simple adaptive greedy algorithm is guaranteed to be competitive with the optimal policy. We illustrate the usefulness of the concept by giving several examples of adaptive submodular objectives arising in diverse applications including sensor placement, viral marketing and pool-based active learning. Proving adaptive submodularity for these problems allows us to recover existing results in these applications as special cases and leads to natural generalizations.
Individual attitudes toward corruption: do social effects matter?

Using individual-level data for 35 countries, Gatti, Paternostro, and Rigolini investigate the microeconomic determinants of attitudes toward corruption. They find women, employed, less wealthy, and older individuals to be more averse to corruption. The authors also provide evidence that social effects play an important role in determining individual attitudes toward corruption, as these are robustly and significantly associated with the average level of tolerance of corruption in the region. This finding lends empirical support to theoretical models where corruption emerges in multiple equilibria and suggests that big-push policies might be particularly effective in combatting corruption. This paper - a joint product of Investment Climate, Development Research Group, and the Poverty Group, Poverty Reduction and Economic Management Network - is part of a larger effort in the Bank to understand the determinants of corruption.
An Organ System Approach to Explore the Antioxidative, Anti-Inflammatory, and Cytoprotective Actions of Resveratrol

Resveratrol is a phenolic phytochemical, with a stilbene backbone, derived from edible plants such as grape and peanut. It is a bioactive molecule with physiological effects on multiple organ systems. Its effects range from the neuroprotective to the nephroprotective, including cardiovascular, neuronal, and antineoplastic responses as a part of its broad spectrum of action. In this review, we examine the effects of resveratrol on the following organ systems: the central nervous system, including neurological pathology such as Parkinson's and Alzheimer's disease; the cardiovascular system, including disorders such as atherosclerosis, ischemia-reperfusion injury, and cardiomyocyte hypertrophy; the kidneys, including primary and secondary nephropathies and nephrolithiasis; multiple forms of cancer; and metabolic syndromes including diabetes. We emphasize commonalities in extracellular matrix protein alterations and intracellular signal transduction system induction following resveratrol treatment. We summarize the known anti-inflammatory, antioxidative, and cytoprotective effects of resveratrol across disparate organ systems. Additionally, we analyze the available literature regarding the pharmacokinetics of resveratrol formulations used in these studies. Finally, we critically examine select clinical trials documenting a lack of effect following resveratrol treatment.
Bridling Central Tyranny in India: How Regional Parties Restrain the Federal Government

Abstract Successive national governments in India have invoked an emergency constitutional provision to impose direct central rule in states over 100 times since 1950. However, such central government usurpation of state governance has declined since the mid-1990s. This essay demonstrates how India9s regional parties, by entering into opportunistic alliances with national parties and joining coalition central governments, have become effective barriers against central dominance. It also identifies the specific dynamics through which this effective veto power is exercised.
Calibrated Incentive Contracts

This paper studies a dynamic agency problem which includes limited liability, moral hazard, and adverse selection. The paper develops a robust approach to dynamic contracting based on calibrating the incentive properties of simple benchmark contracts that are attractive but infeasible, due to limited liability constraints. The resulting dynamic contracts are detail-free and satisfy robust performance bounds independently of the underlying process for returns, which need not be i.i.d. or even ergodic. [PUBLICATION ABSTRACT]
Debt- versus equity-financing in auction designs

A social planner wishes to launch a project but the contenders capable of running the project are cash-constrained and may default. To signal their capabilities, the contenders may finance their bids through debt or equity, depending on the mechanism chosen by the social planner. When moral hazard is absent, it is established as theorems that the ex post efficient social choice function cannot be achieved by any mechanism using only debt financing and can be achieved by a mechanism using equity financing. When moral hazard is present, however, it is illustrated heuristically that equity share discourages effort and exacerbates default more than risky debt does.
Stellar Activity Cycles and Contribution of the Deep Layers Knowledge

It is believed that magnetic activity on the Sun and solar-type stars are tightly related to the dynamo process driven by the interaction between rotation, convection, and magnetic field. However, the detailed mechanisms of this process are still incompletely understood. Many questions remain unanswered, e.g.: why some stars are more active than others?; why some stars have a flat activity?; why is there a Maunder minimum?; are all the cycles regular? A large number of proxies are typically used to study the magnetic activity of stars as we cannot resolve stellar discs. Recently, it was shown that asteroseismology can also be used to study stellar activity, making it an even more powerful tool. If short cycles are not so uncommon, we expect to detect many of them with missions such as CoRoT, Kepler, and possibly the PLATO mission. We will review some of the latest results obtained with spectroscopic measurements. We will show how asteroseismology can help us to better understand the complex process of dynamo and illustrate how the CoRoT and Kepler missions are revolutionizing our knowledge on stellar activity. A new window is being opened over our understanding of the magnetic variability of stars.
Oxygen partial pressure effects on vanadium mobility and catalyst deactivation in a simulated FCCU regenerator

The rate of interparticle vanadium transfer in FCC catalysts as a function of the degree of oxidation of the steaming environment has been determined. The rate of interparticle vanadium transfer is low when the atmosphere in the steamer is reducing, but increases dramatically as the mole % excess oxygen becomes greater than zero. High rate of vanadium transfer is accompanied by a greater loss of surface area and catalytic activity. XPS measurements show that the oxidation state of vanadium increases from +3 when the steamer atmosphere is reducing to +5 when the % excess oxygen is greater than zero. Surface vanadium concentration follows a similar trend. In addition, data from a commercial resid FCCU operating in a partial burn were analyzed. The results of the analyses show that defining a partial burn operation with the flue gas CO/CO 2 ratio is not adequate for characterizing the vanadium oxidation state. Carbon on regenerated catalyst is a better marker for the vanadium oxidation state in the regenerator.
The Formation and Role of Reputation and Litigation in the Auditor–Manager Relationship

In light of recent changes limiting auditors' legal liabilities, we examine the role of audit reputation on the interaction between the auditor and the manager whose actions he is attesting to. Thi...
NMR spectroscopy of experimentally shocked silicate minerals

Magic-angle spinning nuclear magnetic resonance (MAS NMR) techniques were used to analyze experimentally shocked quartz and feldspar powders. 29Si spectra were determined for quartz and labradorite feldspar and 27Al and 23Na spectra for labradorite. Both minerals were shocked to 7.5, 16.5, and 22 GPa using the Sandia “Momma Bear” recovery fixtures. The MAS NMR results for quartz are in full agreement with previous measurements, indicating a high degree of reproducibility. Numerical decomposition of quartz data are consistent with two distinct phases: a defective crystalline quartz and an amorphous-like silica phase. There is a strong correlation between the fraction of amorphous phase and the mean peak shock pressure. The labradorite data are much more complicated, consisting of multiple peaks with no obvious correlation with shock pressure. No amorphous phase was evident from the NMR spectra of the shocked labradorite, nor were high pressure phases detectable for either mineral.
Variation in optical disc birefringence measurements

Optical disc birefringence affects playback performance in a variety of ways and is routinely measured as part of the manufacturing process. However, many disc manufacturers have observed significant variation in birefringence measurements when using commercially available instrumentation. To quantify the reliability of these tools, the Optical Disc Manufacturing Association (ODMA) and NIST performed a round robin intercomparison of optical disc retardance measurements. In this paper, we report that remarkably large measurement variation among instruments indeed exists. We discuss some sources of this variation to show that a substantial part is due to instrument uncertainty, and describe possible error source in one class of polarimetric instruments.
Asymptotic properties of groups acting on complexes

We examine asymptotic dimension and property A for groups acting on complexes. In particular, we prove that the fundamental group of a finite, developable complex of groups will have finite asymptotic dimension provided the geometric realization of the development has finite asymptotic dimension and the vertex groups are finitely generated and have finite asymptotic dimension. We also prove that property A is preserved by this construction provided the geometric realization of the development has finite asymptotic dimension and the vertex groups all have property A. These results naturally extend the corresponding results on preservation of these large-scale properties for fundamental groups of graphs of groups. We also use an example to show that the requirement that the development have finite asymptotic dimension cannot be relaxed.
Leakage suppression in the toric code

Quantum codes excel at correcting local noise but fail to correct leakage faults that excite qubits to states outside the computational space. Aliferis and Terhal have shown that an accuracy threshold exists for leakage faults using gadgets called leakage reduction units (LRUs). However, these gadgets reduce the threshold and increase experimental complexity, and the costs have not been thoroughly understood. We explore a variety of techniques for leakage resilience in topological codes. Our contributions are threefold. First, we develop a leakage model that is physically motivated and efficient to simulate. Second, we use Monte-Carlo simulations to survey several syndrome extraction circuits. Third, given the capability to perform 3-outcome measurements, we present a dramatically improved syndrome processing algorithm. Our simulations show that simple circuits with one extra CNOT per qubit reduce the accuracy threshold by less than a factor of 4 when leakage and depolarizing noise rates are comparable compared to a scenario without leakage. This becomes a factor of 2 when the decoder uses 3-outcome measurements. Finally, we make the surprising observation that for physical error rates less than 2 × 10−4, placing LRUs after every gate may achieve the lowest logical error rate. We expect that the ideas may generalize to other topological codes.
On the reducibility of characteristic varieties

We show that some monodromies in the Morse local systems of a conically stratified perverse sheaf imply that other Morse local systems for smaller strata do not vanish. This result is then used to explain the examples of reducible characteristic varieties of Schubert varieties given by Kashiwara and Saito in type A and by Boe and Fu for the Lagrangian Grassmannian.
Causal diagrams for interference

The term “interference” has been used to describe any setting in which one subject’s exposure may affect another subject’s outcome. We use causal diagrams to distinguish among three causal mechanisms that give rise to interference. The first causal mechanism by which interference can operate is a direct causal effect of one individual’s treatment on another individual’s outcome; we call this direct interference. Interference by contagion is present when one individual’s outcome may affect the outcomes of other individuals with whom he comes into contact. Then giving treatment to the first individual could have an indirect effect on others through the treated individual’s outcome. The third pathway by which interference may operate is allocational interference. Treatment in this case allocates individuals to groups; through interactions within a group, individuals may affect one another’s outcomes in any number of ways. In many settings, more than one type of interference will be present simultaneously. The causal effects of interest differ according to which types of interference are present, as do the conditions under which causal effects are identifiable. Using causal diagrams for interference, we describe these differences, give criteria for the identification of important causal effects, and discuss applications to infectious diseases.
Property testing on product distributions: optimal testers for bounded derivative properties

The primary problem in property testing is to decide whether a given function satisfies a certain property or is far from any function satisfying it. This crucially requires a notion of distance between functions. The most prevalent notion is the Hamming distance over the uniform distribution on the domain. This restriction to uniformity is rather limiting, and it is important to investigate distances induced by more general distributions.In this article, we provide simple and optimal testers for bounded derivative properties over arbitrary product distributions. Bounded derivative properties include fundamental properties, such as monotonicity and Lipschitz continuity. Our results subsume almost all known results (upper and lower bounds) on monotonicity and Lipschitz testing over arbitrary ranges.We prove an intimate connection between bounded derivative property testing and binary search trees (BSTs). We exhibit a tester whose query complexity is the sum of expected depths of optimal BSTs for each marginal. Furthermore, we show that this sum-of-depths is also a lower bound. A technical contribution of our work is an optimal dimension reduction theorem for all bounded derivative properties that relates the distance of a function from the property to the distance of restrictions of the function to random lines. Such a theorem has been elusive even for monotonicity, and our theorem is an exponential improvement to the previous best-known result.
A practical method for monitoring FRET-based biosensors in living animals using two-photon microscopy.

The commercial availability of multiphoton microscope systems has nurtured the growth of intravital microscopy as a powerful technique for evaluating cell biology in the relevant context of living animals. In parallel, new fluorescent protein (FP) biosensors have become available that enable studies of the function of a wide range of proteins in living cells. Biosensor probes that exploit Forster resonance energy transfer (FRET) are among the most sensitive indicators of an array of cellular processes. However, differences between one-photon and two-photon excitation (2PE) microscopy are such that measuring FRET by 2PE in the intravital setting remains challenging. Here, we describe an approach that simplifies the use of FRET-based biosensors in intravital 2PE microscopy. Based on a systematic comparison of many different FPs, we identified the monomeric (m) FPs mTurquoise and mVenus as particularly well suited for intravital 2PE FRET studies, enabling the ratiometric measurements from linked FRET probes using a pair of experimental images collected simultaneously. The behavior of the FPs is validated by fluorescence lifetime and sensitized emission measurements of a set of FRET standards. The approach is demonstrated using a modified version of the AKAR protein kinase A biosensor, first in cells in culture, and then in hepatocytes in the liver of living mice. The approach is compatible with the most common 2PE microscope configurations and should be applicable to a variety of different FRET probes.
Robust future precipitation declines in CMIP5 largely reflect the poleward expansion of model subtropical dry zones

[1] Robust subtropical precipitation declines have been a prominent feature of general circulation model (GCM) responses to future greenhouse warming. Recent work by the authors showed that for the models making up the Coupled Model Intercomparison Project phase 3 (CMIP3), this drying was found mainly in the midlatitude-driven precipitation poleward of the model subtropical precipitation minima. Here, using more comprehensive diagnostics, we extend that work to 36 new CMIP5 models, and find that CMIP5 robust precipitation declines are also found mainly between subtropical minima and midlatitude precipitation maxima, implicating dynamic poleward expansion of dry zones rather than thermodynamic amplification of dry-wet contrasts. We also give the full seasonal cycle of these projected declines, showing that they are much more widespread in local spring than in local fall, and that for most of the year in the Northern Hemisphere they are entirely confined to the Atlantic side of the globe.
73.6 Gy and Beyond: Hyperfractionated, Accelerated Radiotherapy for Non–Small-Cell Lung Cancer

PURPOSE: To assess results with twice-daily high-dose radiotherapy (RT) for non–small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Between 1991 and 1998, 94 patients with unresectable NSCLC were prescribed ≥ 73.6 Gy via accelerated fractionation. Fifty were on a phase II protocol (P group); 44 were similarly treated off-protocol (NP group). The clinical target volume received 45 Gy at 1.25 Gy bid (6-hour interval). The gross target volume received 1.6 Gy bid to 73.6 to 80 Gy over 4.5 to 5 weeks using a concurrent boost technique. Overall survival (OS) and local progression-free survival (LPFS) were calculated by the Kaplan-Meier method. Median follow-up durations for surviving P and NP patients were 67 and 16 months, respectively. RESULTS: Total doses received were ≥ 72 Gy in 97% of patients. The median OS by stage was 34, 13, and 12 months for stages I/II, IIIa, and IIIb, respectively. LPFS was significantly longer for patients with T1 lesions (median, 43 months) versus T2-4 (median, 7 to 10 months; P...
Leaving school in an economic downturn and self-esteem across early and middle adulthood

In this study, we test whether leaving school in an economic downturn impacts self-esteem across early and middle adulthood. Self-esteem is of interest to economists because it is an established determinant of important socioeconomic outcomes such as wages, crime, marriage, health, and civic engagement. Previous research suggests that leaving school in a downturn can depress career trajectories, and social psychological theory predicts that career success is an important determinant of self-esteem. We model responses to a standard measure of self-esteem (the Rosenberg Self-esteem Scale) as a function of the state unemployment rate at school-leaving. We address the potential endogeneity of time and location of school-leaving with instrumental variables. Our results suggest that leaving school in an economic downturn can undermine self-esteem over time.
Jobless capital? The role of capital subsidies

Abstract Using tax abatements, financial incentives, and public investments to attract (or retain) firms is the primary economic development tool for many local governments. Often local job creation policies focus on increasing capital through grants, low-interest financing, and other economic development incentives. Theory predicts that capital subsidies induce firm behaviors that limit their job creation effects. This paper employs the Incentives Environment Index, constructed from state constitutional provisions that limit and structure the ability of state and local governmental entities to aid private enterprises, and county panels to test theoretical predictions on county capital expenditure and input mixes as well as industry establishment shares. The results indicate the act of increasing capital subsidy tools is associated with capital-labor substitution, decreased employment density, and changes in local industry mix. Results are robust to alternative empirical specifications and measures of capital subsidy availability.
Inference by minimizing size, divergence, or their sum

We speed up marginal inference by ignoring factors that do not significantly contribute to overall accuracy. In order to pick a suitable subset of factors to ignore, we propose three schemes: minimizing the number of model factors under a bound on the KL divergence between pruned and full models; minimizing the KL divergence under a bound on factor count; and minimizing the weighted sum of KL divergence and factor count. All three problems are solved using an approximation of the KL divergence than can be calculated in terms of marginals computed on a simple seed graph. Applied to synthetic image denoising and to three different types of NLP parsing models, this technique performs marginal inference up to 11 times faster than loopy BP, with graph sizes reduced up to 98%—at comparable error in marginals and parsing accuracy. We also show that minimizing the weighted sum of divergence and size is substantially faster than minimizing either of the other objectives based on the approximation to divergence presented here.
The Global Supply and Demand for Agricultural Land in 2050: A Perfect Storm in the Making?

The number of people which the world must feed is expected to increase by another 2 billion people by 2050. When coupled with significant nutritional improvements for the 2.1 billion people currently living on less than $2/day, this translates into a very substantial rise in the demand for agricultural production. Most past growth in the demand for food has been met by improvements in productivity, but there is evidence of declining growth rates for agricultural yields; climate-change is likely to have important impacts on productivity through changes in temperature and precipitation; land-based climate mitigation policies are also projected to lead to increasing pressure on agricultural lands. Meanwhile supplies of water for irrigation are under pressure, urban land use is on the rise, and demands for setting aside land for environmental purposes continue to increase. Clearly, an enormous amount of additional research on ways to deal with this potential “perfect storm” is needed. This paper highlights the explores the roles of biophysical and economic uncertainty in these projections of long run land use change, using this to suggest a future research agenda.
Simultaneous variable selection for joint models of longitudinal and survival outcomes

Joint models of longitudinal and survival outcomes have been used with increasing frequency in clinical investigations. Correct specification of fixed and random effects is essential for practical data analysis. Simultaneous selection of variables in both longitudinal and survival components functions as a necessary safeguard against model misspecification. However, variable selection in such models has not been studied. No existing computational tools, to the best of our knowledge, have been made available to practitioners. In this article, we describe a penalized likelihood method with adaptive least absolute shrinkage and selection operator (ALASSO) penalty functions for simultaneous selection of fixed and random effects in joint models. To perform selection in variance components of random effects, we reparameterize the variance components using a Cholesky decomposition; in doing so, a penalty function of group shrinkage is introduced. To reduce the estimation bias resulted from penalization, we propose a two-stage selection procedure in which the magnitude of the bias is ameliorated in the second stage. The penalized likelihood is approximated by Gaussian quadrature and optimized by an EM algorithm. Simulation study showed excellent selection results in the first stage and small estimation biases in the second stage. To illustrate, we analyzed a longitudinally observed clinical marker and patient survival in a cohort of patients with heart failure.
Coronary blood flow in dogs: effect of person

Experiments on dogs with electromagnetic flow probes implanted around a coronary artery and the ascending aorta indicate that the entry of a person into the experimental chamber can cause a remarkable increase in coronary blood flow. Heart rate usually increases considerably, blood pressure increases only slightly, while aortic blood flow increases at variable times before and after coronary blood flow. It is not yet clear whether these cardiovascular effects are due purely to “effect of person” or to conditioning, with the person as the signal for the momentary coronary occlusion (which the person subsequently accomplishes by manually closing a snare).
Gibbs free energy of formation of NdB4 and Nd2FeB3

Abstract The Gibbs free energy of formation of NdB 4 and Nd 2 FeB 3 was determined at temperatures between 996 and 1061 K by means of e.m.f. measurement of galvanic cells with a CaF 2 single-crystal solid electrolyte. The measurements resulted in ΔG ° NdB 4 = (−838.5 + 4.1 × 10 −1 T ) × 10 3 J mol −1 and ΔG ° Nd 2 FeB 3 = (−1019.9 + 4.6 × 10 −1 T )× 10 3 J mol −1 .