cssi/SciSciGPT-SciSciNet huggingface dataset:
Trade liberalization, firm heterogeneity, and wages : new evidence from matched employer-employee data

In this paper, the authors use a linked employer-employee database from Brazil to examine the impact of trade reform on the wages of workers employed at heterogeneous firms. The analysis of the data at the firm-level confirms earlier findings of a differential positive effect of trade liberalization on the average wages at exporting firms relative to non-exporting firms. However, this analysis of average firm-level wages is incomplete along several dimensions. First, it cannot fully account for the impact of a change in trade barriers on workforce composition especially in terms of unobservable (time-invariant) characteristics of workers (innate ability) and any additional productivity that obtains in the context of employment in the specific firm (match specific ability). Furthermore, the firm-level analysis is undertaken under the assumption that the assignment of workers to firms is random. This ignores the sorting of worker into firms and leads to a bias in estimates of the differential impact of trade on workers at exporting firms relative to non-exporting firms. Using detailed information on worker and firm characteristics to control for compositional effects and using firm-worker match specific effects to account for the endogenous mobility of workers, the authors find the differential effect of trade openness on wages in exporting firms relative to domestic firms to be insignificant. Consistent with the models of Helpman, Itskhoki, and Redding (2010) and Davidson, Matusz and Schevchenko (2008), they also find that the workforce composition improves systematically in exporting firms in terms of innate (time invariant) worker ability and in terms the quality of the worker-firm matches.
General purpose parallel architectures

Publisher Summary This chapter focuses on general purpose parallel architectures. Multiprocessor parallel computation has been considered in the context of problems with large inherent parallelism. The results suggest that the XPRAM might turn out to be an appropriate aspiration for the parallel computer architect much as the von Neumann model is in the sequential case. It is conceptually simple, capturing as it does the idea of message passing synchronized in bulk. It is a suitable host on to which higher-level communication and storage management functions can be efficiently compiled. Furthermore, it is a promising candidate for efficient implementation in foreseeable technologies. An XPRAM with ρ processors executes operations in supersteps. In each superstep, each processor executes a number of local instructions and sends or receives some messages that implement global read or write instructions. XPRAM embodies the principle of bulk-synchrony, that is, the processors should be barrier synchronized at regular time intervals long enough for several packets to be transmitted between a pair of nodes.
Iterative optimization and simplification of hierarchical clusterings

Clustering is often used for discovering structure in data. Clustering systems differ in the objective function used to evaluate clustering quality and the control strategy used to search the space of clusterings. Ideally, the search strategy should consistently construct clusterings of high quality, but be computationally inexpensive as well. In general, we cannot have it both ways, but we can partition the search so that a system inexpensively constructs a 'tentative' clustering for initial examination, followed by iterative optimization, which continues to search in background for improved clusterings. Given this motivation, we evaluate an inexpensive strategy for creating initial clusterings, coupled with several control strategies for iterative optimization, each of which repeatedly modifies an initial clustering in search of a better one. One of these methods appears novel as an iterative optimization strategy in clustering contexts. Once a clustering has been constructed it is judged by analysts - often according to task-specific criteria. Several authors have abstracted these criteria and posited a generic performance task akin to pattern completion, where the error rate over completed patterns is used to 'externally' judge clustering utility. Given this performance task, we adapt resampling-based pruning strategies used by supervised learning systems to the task of simplifying hierarchical clusterings, thus promising to ease post-clustering analysis. Finally, we propose a number of objective functions, based on attribute-selection measures for decision-tree induction, that might perform well on the error rate and simplicity dimensions.
Covert communications despite traffic data retention

We show that Alice and Bob can communicate covertly and anonymously, despite Eve having access to the traffic data of most machines on the Internet. Our protocols take advantage of small amounts of shared state that exist in many TCP/IP stacks, and use them to construct a covert channel. Techniques inspired from Direct Sequence Spread Spectrum (DSSS) are used to make sure that the communication is covert and resistant to noise. We implement a prototype based on ICMP Echo (ping) to illustrate the practicality of our approach and discuss how a more complex protocol would modulate information through the use of TCP features to make communication detection very difficult. The feasibility of covert communications despite stringent traffic data retention, has far reaching policy consequences.
Orthogonal Queries in Segments and Triangles

We present an efficient orthogonal query data structure in a set of segments or triangles in space. The most important feature of our results is that the efficiency of the data structure is highly dependent on the geometric discrete parameters of the input set, as well as its cardinality.
Two case studies on electronic distribution of government securities: the U.S. Treasury Direct System and the Philippine Expanded Small Investors Program

The case study on the U.S. Treasury Direct examines the evolution of the electronic distribution systems for marketable and nonmarketable government securities, the main objectives, and the basic legal infrastructure and the preconditions enabling the system. The U.S. experience highlights that the enabling environment and infrastructure (for example, in terms of information databases such as Pay.Gov) make a large difference in terms of both the security and convenience that customers can expect in the use of the system. The system also achieved important cost savings for the Bureau of the Public Debt. The case study on the Small Investors Program of the Philippines looks at a program that the Philippine government has been experimenting with to sell its securities directly to retail investors over the Internet. The recently revised version of the program-called the Expanded Small Investors Program-aims to increase access to government securities and distribute them more widely, develop better savings products, and enhance competition in the primary markets for these securities. The authors analyze whether the program's main goals can be achieved while mitigating the risks. Their analysis suggests that there are good reasons to believe that the new program will succeed. Still, regular and responsive assessments and adjustments will be required as the program moves forward.
Teaching Statistics: Sources†

Seventeen books, six journals, and a web page that are useful for statistics teachers are reviewed. Sources are ordered from general to technical, and examples illustrative of the content appear in the descriptions. Keywords: pedagogy; teaching; teaching activities; teaching demonstrations; teaching resources
Governing Prostitution: Differentiating the Bad from the Bad

Accounts of the governance of prostitution have typically argued that prostitutes are, in one way or another, stigmatised social outcasts. There is a persistent claim that power has operated to dislocate or banish the prostitute from the community in order to silence, isolate, hide, restrict, or punish. I argue that another position may be tenable; that is, power has operated to locate prostitution within the social. Power does not operate to 'de-socialise' prostitution, but has in recent times operated increasingly to normalise it. Power does not demarcate prostitutes from the social according to some binary mechanics of difference, but works instead according to a principle of differentiation which seeks to connect, include, circulate and enable specific prostitute populations within the social. In this paper I examine how prostitution has been singled out for public attention as a socio-political problem and governed accordingly. The concept of governmentality is used to think through such issues, providing, as it does, a non-totalising and non-reductionist account of rule. It is argued that a combination of self-regulatory and punitive practices developed during modernity to manage socially problematic prostitute populations.
Development of High Activity, Coal-Derived, Promoted Catalytic Systems for NOx Reduction at Low Temperatures

This project is directed at an investigation of catalytic NO{sub x} reduction mechanisms on coal-derived, activated carbon supports at low temperatures. Promoted carbon systems offer some potentially significant advantages for heterogeneous NO{sub x} reduction. These include: low cost; high activity at low temperatures, which minimizes carbon loss; oxygen resistance; and a support material which can be engineered with respect to porosity, transport and catalyst dispersion characteristics. During the reporting period, the following has been accomplished: (1) A packed bed reactor/gas flow system has been tested and applied to performing NO-carbon reactivity studies. This system employs a Kin-Tek gas calibration/mixing system for varying NO and CO concentrations in the feed gas to the packed bed, a NO{sub x} chemiluminescence analyzer (ThermoElectron, Model 10), and a quadrupole mass spectrometer (Ametek). This system is used for both steady-state reactivity studies, as well as mechanistic studies on the effects of NO and CO in the gas phase on intermediate oxygen surface complex populations on the carbon substrates. (2) Reactivity studies of the NO-carbon system have been performed as a function of temperature and NO concentration. It was found that apparent activation energy in the ''high temperature'' regime of 180 {+-} 10 kJ/mol agrees wellmore » with corresponding values reported in the literature. At the low NO concentrations used, it was observed that the reaction is not strictly first order in NO. In addition, the influence of mass transfer limitations were noted at high temperatures and low NO concentrations. Plans for the next reporting period include applications of the packed bed reactor system to perform temperature programmed desorption studies of the reaction of the NO-carbon reaction, and to reactivity studies of the NO/CO reaction system.« less
The c++0x concepts effort

C++0x is the working title for the revision of the ISO standard of the C++ programming language that was originally planned for release in 2009 but that was delayed to 2011. The largest language extension in C++0x was "concepts", that is, a collection of features for constraining template parameters. In September of 2008, the C++ standards committee voted the concepts extension into C++0x, but then in July of 2009, the committee voted the concepts extension back out of C++0x. This article is my account of the technical challenges and debates within the "concepts" effort in the years 2003 to 2009. To provide some background, the article also describes the design space for constrained parametric polymorphism, or what is colloquially know as constrained generics. While this article is meant to be generally accessible, the writing is aimed toward readers with background in functional programming and programming language theory. This article grew out of a lecture at the Spring School on Generic and Indexed Programming at the University of Oxford, March 2010.
Total institutions and the possibility of consent to organic therapies.

Certain contemporary forms of organic therapy used in an attempt to correct or control deviance strike terror into the hearts of traditional liberals and humanists. In addition to radical forms to behavior modification therapy (e.g., the use of “shock sticks” or “cattle prods” on autistic children and the administration of drugs which produce symptoms of suffocation in patients), psychosurgery has also experienced a resurgence of popularity. Its use has been advocated (and sometimes practiced) on impulsively violent persons and on so-called “hyperkinetic” children.
Credit Constraints as a Barrier to Technology Adoption by the Poor : Lessons from South-Indian Small-Scale Fishery

Globalization has affected the livelihoods of fishing communities in South Asia in several ways since the late 1950s. In this chapter we study one facet of these developments — the adoption of beach-landing fibre-reinforced plastic (FRP) boats by fishing households in Tamil Nadu, India. The diffusion of this new technology, which replaces traditional wooden boats, is as much a product of ongoing globalizing trends as it is a response to distortions caused by previous waves of innovation triggered by globalization.
On the Optimality of Randomized Deadlock Avoidance Policies

This paper revisits the problem of selecting an optimal deadlock resolution strategy, when the selection criterion is the maximization of the system throughput, and the system is Markovian in terms of its timing and routing characteristics. This problem was recently addressed in some of our previous work, that (i) provided an analytical formulation for it, (ii) introduced the notion of randomized deadlock avoidance as a generalization of the more traditional approaches of deadlock prevention/avoidance, and detection and recovery, and (iii) provided a methodology for selecting the optimal randomized deadlock avoidance policy for a given resource allocation system (RAS) configuration. An issue that remained open in the problem treatment of that past work, was whether the proposed policy randomization is essential, i.e., whether there exist any RAS configurations for which a randomized deadlock avoidance policy is superior to any other policy that does not employ randomization. The work presented in this paper establishes that for the basic problem formulation where the only concern is the (unconstrained) maximization of the system throughput—or the other typical performance objectives of minimizing the system work-in-process and mean sojourn time—randomization of the deadlock resolution strategy is not essential. However, it is also shown that, sometimes, it can offer an effective mechanism for accommodating additional operational constraints, like the requirement for production according to a specified product mix. Furthermore, the undertaken analysis provides an analytical characterization of the dependence of the aforementioned performance measures on the transition rates relating to the various events of the underlying state space, which can be useful for the broader problem of synthesizing efficient scheduling policies for the considered class of resource allocation systems.
Family Health Benefits and Worker Turnover

In this paper, I examine the impact of employer-provided health benefits on job turnover. Because many employer-provided plans extend coverage to a worker's entire family, the value of an employer's employment offer to a worker depends on whether the worker's spouse provides the family with health benefits. If a worker's spouse has an employer-provided health insurance for their family, the worker will value employment offers with and without health insurance benefits differently than a worker whose spouse does not have employer-provided health benefits. Importantly, this distortion arises from the reliance on employer-provided benefits and is independent of any pre-existing conditions clauses or issues concerning the portability of health plans. The estimates suggest that spouse-provided benefits substantially increase the likelihood of turnover.
The evolution of conferencing

Visual communication has a long history in the UK with the first public service established nearly 25 years ago, called ‘Confravision’, which linked London, Manchester, Birmingham, Bristol and Glasgow [1]. Soon after this, advances were made in video coding techniques in which it was possible to compress the video signal and transmit it over digital circuits. This work was ground breaking not just because 100 to 1 compression was achieved on the video pictures, but also because for the first time companies collaborated together to define the standards, thus recognizing that people ultimately needed to be able to communicate outside closed user groups [2].
Not Dead Yet

* Horace O. Coil (‘57) Chair in Litigation, University of California, Hastings College of the Law. This paper was the basis for my remarks at the Association of American Law Schools (AALS) Section of Civil Procedure session during the AALS Annual Meeting in New York City in January, 2008. XXxSince 1996, I have served as Special Reporter to the Advisory Committee on Civil Rules, and drew to some extent on this experience in preparing these remarks. But these views are mine and not presented on behalf of the Advisory Committee or anyone else. XXxThis piece is significantly based on work that I have published elsewhere. See Richard L. Marcus, Confessions of a Federal “Bureaucrat”: The Possibilities of Perfecting Procedural Reform, 35 W. ST. U. L. REV. 103 (2007) [hereinafter Marcus, Confessions]; Richard L. Marcus, Reform Through Rulemaking?, 80 WASH. U. L.Q. 901 (2002) [hereinafter Marcus, Reform]; Richard L. Marcus, Of Babies and Bathwater: The Prospects for Procedural Progress, 59 BROOK. L. REV. 761 (1993) [hereinafter Marcus, Of Babies]. 1. Jack H. Friedenthal, The Rulemaking Power of the Supreme Court: A Contemporary Crisis, 27 STAN. L. REV. 673, 676 (1975). 2. See Judicial Improvements and Access to Justice Act, Pub. L. 100-702, § 407, 102 Stat. 4642, 4652 (1988) (codified as amended at 28 U.S.C. § 2073 (2000)); see also infra note 41 and accompanying text. 3. Charles Alan Wright, Foreword: The Malaise of Federal Rulemaking, 14 REV. LITIG. 1, 9 (1994). 4. Linda S. Mullenix, Hope Over Experience: Mandatory Informal Discovery and the Politics of Rulemaking, 69 N.C. L. REV. 795, 802 (1991). 5. Laurens Walker, The End of the New Deal and the Federal Rules of Civil Procedure, 82 IOWA L. REV. 1269, 1271 (1997). 6. Robert G. Bone, The Process of Making Process: Court Rulemaking, Democratic Legitimacy, and Procedural Efficacy, 87 GEO. L.J. 887, 888 (1999).
Neutral Property Taxation

A major difficulty in implementing land/site value taxation is imputing the land value of built-on sites. The literature has focused on two alternatives. The first, residual site value, measures postdevelopment site value as property value less structure value, with structure value measured as depreciated construction costs. Residual site value would be relatively easy to estimate, but a residual site value tax system, which taxes land value before development and residual site value after development at the same rate is distortionary, discouraging density. The second, raw site value, measures postdevelopment site value as “what the land would be worth were there no building on the site (though in fact there is).” Raw site value taxation is neutral (does not distort the timing and density of development), but the estimation of postdevelopment raw site value would be complex so that assessment would likely be less fair and more arbitrary, contentious, and prone to abuse. This paper asks the question: Is it not possible to design a property tax system (taxation of predevelopment land value, postdevelopment structure value, and postdevelopment site value at possibly different rates) that employs the administratively simpler residual definition of postdevelopment site value and achieves neutrality? Under restrictive assumptions and subject to an important qualification, the paper provides an affirmative answer, and characterizes the tax rates that achieve neutrality. It also briefly discusses issues of practical implementation.
A 3-V, 0.35-/spl mu/m CMOS Bluetooth receiver IC

A fully integrated CMOS low-IF Bluetooth receiver is presented. The receiver consists of a radio frequency (RF) front end, a phase-locked loop (PLL), an active complex filter, a Gaussian frequency shift keying (GFSK) demodulator, and a frequency offset cancellation circuit. The highlights of the receiver include a low-power active complex filter with a nonconventional tuning scheme and a high-performance mixed-mode GFSK demodulator. The chip was fabricated on a 6.25-mm/sup 2/ die using TSMC 0.35-/spl mu/m standard CMOS process. -82 dBm sensitivity at 1e-3 bit error rate, -10 dBm IIP3, and 15 dB noise figure were achieved in the measurements. The receiver active current is about 65 mA from a 3-V power supply.
2+1 Dimensional Quantum Gravity and the Braid Group

Elsewhere in these proceedings [1], Jackiw has described an interesting calculation of scattering amplitudes in 2+1 dimensional gravity. His approach [2], like that of ‘t Hooft [3], starts from the observation that there is no classical gravitational radiation in 2+1 dimensions: solutions of the field equations are locally flat outside sources, and the gravitational interaction depends only on the global geometry. In the absence of propagating gravitational degrees of freedom, one way to quantize the theory is to use the field equations to eliminate the metric, and to then quantize the remaining matter degrees of freedom. One then has the physically intuitive picture of quantized particles each moving in the background conical geometry induced by the others. For two-particle scattering, this picture is especially simple, since one may use center of mass coordinates [3] to reduce the problem to one of solving the Schrodinger equation on a cone.
Don't `Have a Clue'? Unsupervised Co-Learning of Downward-Entailing Operators.

Researchers in textual entailment have begun to consider inferences involving downward-entailing operators, an interesting and important class of lexical items that change the way inferences are made. Recent work proposed a method for learning English downward-entailing operators that requires access to a high-quality collection of negative polarity items (NPIs). However, English is one of the very few languages for which such a list exists. We propose the first approach that can be applied to the many languages for which there is no pre-existing high-precision database of NPIs. As a case study, we apply our method to Romanian and show that our method yields good results. Also, we perform a cross-linguistic analysis that suggests interesting connections to some findings in linguistic typology.
Variable Selection in Data Mining: Building a Predictive Model for Bankruptcy

We predict the onset of personal bankruptcy using least squares regression. Although well publicized, only 2,244 bankruptcies occur in our dataset of 2.9 million months of credit-card activity. We use stepwise selection to find predictors of these from a mix of payment history, debt load, demographics, and their interactions. This combination of rare responses and over 67,000 possible predictors leads to a challenging modeling question: How does one separate coincidental from useful predictors? We show that three modifications turn stepwise regression into an effective methodology for predicting bankruptcy. Our version of stepwise regression (1) organizes calculations to accommodate interactions, (2) exploits modern decision theoretic criteria to choose predictors, and (3) conservatively estimates p-values to handle sparse data and a binary response. Omitting any one of these leads to poor performance. A final step in our procedure calibrates regression predictions. With these modifications, stepwise regr...
On the experimental violation of Mermin's inequality with imperfect measurements

We investigate theoretically the feasibility of an experimental test of the Bell-type inequality derived by Mermin for correlated spins larger than 1/2. Using the Schwinger representation, we link the output fields of two two-mode squeezers in order to create correlated effective spins between two observers. Spin measurements will be performed by photon-number-resolved photodetection, which has recently come of age. We examine the effect of nonideal detection quantum efficiency--and any other optical loss--on the violation margin of Mermin's inequality. We find that experimental violation is well accessible for spins larger than 1, for quantum efficiencies compatible with the current state of the art.
The Feasibility of Further Ethanol Expansion

Over the course of the last few years ethanol production has expanded at an incredible pace, putting strain on corn markets and transportation systems throughout the Midwest. Driven by the government subsidy and profit possibilities, firm entry rates have spiked. Previous to 2006-2007 the ethanol industry had been consuming feedstock dedicated to export, so little effect was felt by food markets. After 2007 ethanol’s demand for corn will begin to weigh on food markets as reduced supply drives up prices. Corn supply is fast becoming a binding constraint to the ethanol’s growth rate. The feasibility of its further expansion hinges upon the growth and technological advances of corn production, along with the ability of the industry to function profitably without the subsidy.
Recent Progress in Understanding Quark and Gluon Distribution Functions for Large Nuclei at Small x

The theoretical question which will be addressed in this talk is the computation of quark and gluon distribution functions at small Bjorken x. The reason why such computations may be possible is because at small values of Bjorken x, which correspond to central values of rapidity, the density of partons per unit area satisfies
Nuclear-dominated accretion and subluminous supernovae from the merger of a white dwarf with a neutron star or black hole

We construct one dimensional steady-state models of accretion disks produced by the tidal disruption of a white dwarf (WD) by a neutron star (NS) or stellar mass black hole (BH). At radii r ∼ 10 8.5 − 10 9 cm the midplane density and temperature are suffi ciently high to burn the initial white dwarf material into increasingly heavier elements (e.g. Mg, Si, S, Ca, Fe, and Ni) at sequentially smaller radii. When the energy relea sed by nuclear reactions is comparable to that released gravitationally, we term the disk a nuclear-dominated accretion flow (NuDAF). At small radii ∼ 10 7 cm iron photo-disintegrates into helium and then free nuclei, and in the very innermost disk cooling by neutrinos may be effi cient. At the high accretion rates of relevance∼ 10 −4 − 0.1M⊙ s −1 , most of the disk is radiatively ineffi cient and prone to outflows powered by viscous dissipation and nuclear burning . Outflow properties are calculated by requiring that material in the midplane be marginal ly bound (Bernoulli constant ∼ 0), due (in part) to cooling by matter escaping the disk. For reas onable assumptions regarding the properties of disk winds, we show that a significant fraction ( ∼ 50− 80%) of the total WD mass is unbound. The composition of the ejecta is predominantly O, C, Si, Mg, Ne, Fe, and S [He, C, Si, S, Ar, and Fe], in the case of C-O [pure He] WDs, respectively, along with a small quantity∼ 10 −3 − 10 −2 M⊙ of radioactive 56 Ni and, potentially, a trace amount of hydrogen. Depending on the pressure dependence of wind cooling, we find that the disk may be thermally unstable to nuclear burning, the likelihood of which increases for higher mass WDs. We use our results to evaluate possible electromagnetic counterparts of WD-NS/BH mergers, including optical transients powered by the radioacti ve decay of 56 Ni and radio transients powered by the interaction of the ejecta with the interstell ar medium. We address whether recently discovered subluminous Type I supernovae result from WD-NS/BH mergers. Ultimately assessing the fate of these events requires global si mulations of the disk evolution, which capture the complex interplay between nuclear burning, convection, and outflows.
Wage Determination in Northeast Brazil

The author analyzes the labor markets in the Northeast region of Brazil that includes Pernambuco, Bahia, and Ceara states. Her findings show a rather heterogeneous impact pattern of individual characteristics on monthly wages across the wage distribution. That is, the magnitude of the effect of a wage determinant is different depending on whether the worker is placed in the lower, median, or top of the wage distribution. The findings reveal that basic schooling matters for all four geographical areas and across the income distribution. However, poor workers are awarded lower returns than their richer peers, and in Bahia and Ceara, the poor do not obtain any returns to basic schooling. Furthermore, the impact of 5-8 or 9-11 years of education is larger than that of 1-4 years of completed education. The returns obtained by a median worker are higher in Ceara and Pernambuco than in Bahia. Finally, completed tertiary education offers the largest returns of all levels of education. The median worker receives a premium of 105, 249, and 216 percent in Ceara, Pernambuco, and Bahia, respectively. Hence, one direct policy implication is to increase the quality of education, in particular in poorer neighborhoods. Experience impacts positively on wages and it increases with age until workers reach 50 years of age. However, returns to experience are falling significantly across the wage distribution. For the poor and younger generations, experience contributes more to wages than education. The occupation of workers is important for wage determination. All workers in the included occupational groups are paid more than workers engaged in agricultural activities. Workers employed as technicians or administrators obtain the highest returns. The white/nonwhite wage disparity reveals that white workers are paid 17 percent more than their nonwhite co-workers, taking into account other characteristics. Gender disparities are large in the Northeast and heterogeneous across the wage distribution. The time spent in the current state impacts adversely on wages. That is, those that have stayed earn, on average, less than the newcomers. There are no considerable differences between male and female workers. Union membership has a positive impact on workers' wages.
A hierarchical graphical model for record linkage

The task of matching co-referent records is known among other names as record linkage. For large record-linkage problems, often there is little or no labeled data available, but unlabeled data shows a reasonably clear structure. For such problems, unsupervised or semi-supervised methods are preferable to supervised methods. In this paper, we describe a hierarchical graphical model framework for the record-linkage problem in an unsupervised setting. In addition to proposing new methods, we also cast existing unsupervised probabilistic record-linkage methods in this framework. Some of the techniques we propose to minimize overfitting in the above model are of interest in the general graphical model setting. We describe a method for incorporating monotonicity constraints in a graphical model. We also outline a bootstrapping approach of using "single-field" classifiers to noisily label latent variables in a hierarchical model. Experimental results show that our proposed unsupervised methods perform quite competitively even with fully supervised record-linkage methods.
An analytic model for rotational modulations in the photometry of spotted stars

Photometric rotational modulations due to starspots remain the most common and accessible way to study stellar activity. In the Kepler-era, there now exists precise, continuous photometry of ∼150 000 stars presenting an unprecedented opportunity for statistical analyses of these modulations. Modelling rotational modulations allows one to invert the observations into several basic parameters, such as the rotation period, spot coverage, stellar inclination and differential rotation rate. The most widely used analytic model for this inversion comes from Budding and Dorren, who considered circular, grey starspots for a linearly limb darkened star. In this work, we extend the model to be more suitable in the analysis of high precision photometry, such as that by Kepler. Our new freely available fortran code, macula, provides several improvements, such as non-linear limb darkening of the star and spot, a single-domain analytic function, partial derivatives for all input parameters, temporal partial derivatives, diluted light compensation, instrumental offset normalizations, differential rotation, starspot evolution and predictions of transit depth variations due to unocculted spots. Through numerical testing, we find that the inclusion of non-linear limb darkening means macula has a maximum photometric error an order-of-magnitude less than that of Dorren, for Sun-like stars observed in the Kepler-bandpass. The code executes three orders-of-magnitude faster than comparable numerical codes making it well suited for inference problems.
List-Decoding Algorithms for Lifted Codes

Lifted Reed–Solomon codes are a natural affine-invariant family of error-correcting codes, which generalize Reed–Muller codes. They were known to have efficient local-testing and local-decoding algorithms (comparable with the known algorithms for Reed–Muller codes), but with significantly better rate. We give efficient algorithms for list decoding and local list decoding of lifted codes. Our algorithms are based on a new technical lemma, which says that the codewords of lifted codes are low degree polynomials when viewed as univariate polynomials over a big field (even though they may be very high degree when viewed as multivariate polynomials over a small field).
Direct, rapid, solvent-free conversion of unactivated esters to amides using lithium hydroxide as a catalyst

A simple, solvent-free methodology is reported for the direct conversion of esters to amides using lithium hydroxide as a catalyst. The approach allows for the preparation of a range of amide products as well as being applicable to the ring-opening of a representative lactone.
Incidence, risk factors, and outcomes for atrial arrhythmias in trauma patients

The purpose of this study is to determine the incidence, risk factors, and outcomes after the development of an atrial arrhythmia (AA) in trauma patients admitted to the intensive care unit (ICU). We performed a retrospective study of more than 7 years of trauma patients admitted to the ICU at an urban, academic Level I trauma center. Patients with AA, defined as atrial fibrillation, atrial flutter, or paroxysmal supraventricular tachycardia, were compared with patients without AA. Groups were compared by univariate and multivariate analysis. Three thousand, four hundred and ninety-nine trauma patients were admitted to the ICU during the study period and 210 (6%) developed an AA. AA patients were more likely to sustain blunt trauma, were older, more often female, more severely injured, and sustained more head injuries. The only independent risk factor for developing an AA was age > 55 years (odds ratio = 4.6, P < 0.01). Mortality was higher in the AA group (33% vs. 14%, P < 0.01) and AA was an independent risk factor for mortality (odds ratio = 1.7, P = 0.01). Twenty-eight per cent (n = 59) of AA patients received beta-blockers in the postinjury period, and these patients had lower mortality (22% vs. 37%, P = 0.04). AA occurs in 6 per cent of trauma patients admitted to the ICU. Developing an AA is an independent risk factor for mortality after trauma. Beta-blocker therapy was associated with decreased mortality in trauma patients with AA.
Bidirectional coherent classical communication

A unitary interaction coupling two parties enables quantum or classical communication in both the forward and backward directions. Each communication capacity can be thought of as a tradeoff between the achievable rates of specific types of forward and backward communication. Our first result shows that for any bipartite unitary gate, bidirectional coherent classical communication is no more difficult than bidirectional classical communication -- they have the same achievable rate regions. Previously this result was known only for the unidirectional capacities (i.e., the boundaries of the tradeoff). We then relate the tradeoff for two-way coherent communication to the tradeoff for two-way quantum communication and the tradeoff for coherent communication in one direction and quantum communication in the other.
World Food Prices and Human Development: Policy Simulations for Archetype Low-Income Countries

In recent years, world food prices have increased and fluctuated widely. This paper explores the impact of international food prices and domestic policies on Millennium Development Goal (MDG) and macro indicators for two archetype low-income countries, a net food exporter and a net food importer, using Maquette for MDG Simulations (MAMS), a Computable General Equilibrium model. The simulations, which cover the period 2011-2025, indicate that the size of positive (negative) effects on macro and MDG indicators of a food export (import) price increase depend on the initial gross domestic product share for food exports (imports), leaving countries that are heavily involved in international food trade more exposed to international shocks. Given relatively low elasticity estimates, the impact of changes in food prices on undernourishment are relatively marginal. Flexible responses (in terms of production shares, whether output is exported or sold at home, and whether domestic demanders buy imports or domestic output) enable countries to benefit from or be less hurt by price changes. The case for policy responses to higher import prices is stronger for the net food importer. An untargeted food subsidy, financed by taxes or spending cuts, reduces undernourishment at the cost of a slight deterioration for most other indicators. By contrast, aid-financed food subsidies neutralize the negative impact of higher import prices whereas financing via domestic borrowing is counterproductive, leading to a deterioration across all indicators. If administered at moderate costs, tax-financed targeted transfers more effectively reduce headcount poverty and inequality with macroeconomic repercussions similar to those of tax-financed subsidies.
Exact time-dependent solutions for the thin accretion disc equation: boundary conditions at finite radius

We discuss Green's function solutions of the equation for a geometrically thin, axisymmetric Keplerian accretion disc with a viscosity prescription ν ∝ R n . The mathematical problem was solved by Lynden-Bell & Pringle for the special cases with boundary conditions of zero-viscous torque and zero mass flow at the disc centre. While it has been widely established that the observational appearance of astrophysical discs depends on the physical size of the central object(s), exact time-dependent solutions with boundary conditions imposed at finite radius have not been published for a general value of the power-law index n. We derive exact Green's function solutions that satisfy either a zero-torque or a zero-flux condition at a non-zero inner boundary R in > 0, for an arbitrary initial surface density profile. Whereas the viscously dissipated power diverges at the disc centre for the previously known solutions with R in = 0, the new solutions with R in > 0 have finite expressions for the disc luminosity that agree, in the limit t → ∞, with standard expressions for steady-state disc luminosities. The new solutions are applicable to the evolution of the innermost regions of thin accretion discs.
Enantioselective Copper‐Catalyzed Quinoline Alkynylation

A highly enantioselective copper-catalyzed alkynylation of quinolinium salts is reported. The reaction employs StackPhos, a newly developed imidazole-based chiral biaryl P,N ligand, and copper bromide to effect a three-component reaction between a quinoline, a terminal alkyne, and ethyl chloroformate. Under the reaction conditions, the desired products are delivered in high yields with ee values of up to 98 %. The transformation tolerates a wide range of functional groups with respect to both the alkyne and the quinoline starting materials and the products are easily transformed into useful synthons. Efficient, enantioselective syntheses of the tetrahydroquinoline alkaloids (+)-galipinine, (+)-angustureine, and (-)-cuspareine are reported.
The Surroundings of Gamma-Ray Bursts: Constraints on Progenitors

The association of a supernova with a gamma-ray burst (GRB 030329) implies a massive star progenitor, which is expected to have an environment formed by pre-burst stellar winds. Although some sources are consistent with the expected wind environment, many are not, being better fit by a uniform density environment. One possibility is that this is a shocked wind, close to the burst because of a high interstellar pressure and a low mass loss density. Alternatively, there is more than one kind of burst progenitor, some of which interact directly with the interstellar medium. Another proposed environment is a pulsar wind bubble that has expanded inside a supernova, which requires that the supernova precede the burst.
Adaptive online learning

We propose a general framework for studying adaptive regret bounds in the online learning setting, subsuming model selection and data-dependent bounds. Given a data- or model-dependent bound we ask, "Does there exist some algorithm achieving this bound?" We show that modifications to recently introduced sequential complexity measures can be used to answer this question by providing sufficient conditions under which adaptive rates can be achieved. In particular each adaptive rate induces a set of so-called offset complexity measures, and obtaining small upper bounds on these quantities is sufficient to demonstrate achievability. A cornerstone of our analysis technique is the use of one-sided tail inequalities to bound suprema of offset random processes. Our framework recovers and improves a wide variety of adaptive bounds including quantile bounds, second order data-dependent bounds, and small loss bounds. In addition we derive a new type of adaptive bound for online linear optimization based on the spectral norm, as well as a new online PAC-Bayes theorem.
Acousto-optic modulation of a photonic crystal nanocavity with Lamb waves in microwave K band

Integrating nanoscale electromechanical transducers and nanophotonic devices potentially can enable acousto-optic devices to reach unprecedented high frequencies and modulation efficiency. Here, we demonstrate acousto-optic modulation of a photonic crystal nanocavity using Lamb waves with frequency up to 19 GHz, reaching the microwave K band. The devices are fabricated in suspended aluminum nitride membrane. Excitation of acoustic waves is achieved with interdigital transducers with period as small as 300 nm. Confining both acoustic wave and optical wave within the thickness of the membrane leads to improved acousto-optic modulation efficiency in these devices than that obtained in previous surface acoustic wave devices. Our system demonstrates a scalable optomechanical platform where strong acousto-optic coupling between cavity-confined photons and high frequency traveling phonons can be explored.
Perceived Social Competence and Loneliness Among Young Children with ASD: Child, Parent and Teacher Reports

Perceived loneliness and social competence were assessed for 127 children with ASD without comorbid ID, 4–7 years old, through child self-report. Using an abbreviated version of the Loneliness and Social Dissatisfaction Questionnaire (LSDQ; Cassidy and Asher in Child Dev 63:250–365, 1992), the majority of children reported friendships, yet a considerable proportion also reported social difficulties. Factor analysis of the abbreviated LSDQ identified three factors, which were significantly associated with parent- and teacher-reported variables. Regression analyses revealed parent-reported social skills deficits and teacher-reported conflict in the student–teacher relationship to be associated with child-reported loneliness. Implications for practice are discussed.
Governance in the health sector : a strategy for measuring determinants and performance

Many different strategies have been proposed to improve the delivery of health care services, from capacity building to establishing new payment mechanisms. Recent attention has also asked whether improvements in the way health care services are governed could make a difference. These approaches ask which factors -- such as rules and institutions -- influence the behavior of the system in ways that are associated with better performance and outcomes. This paper reviews the concept of governance as it is used in the literature on private firms, public administration, international development and health. It distinguishes between indicators that measure governance determinants from those that measure governance performance in order to propose a framework that is analytically coherent and empirically useful. The framework shows how these indicators can be used to test hypotheses about which governance forms are more useful for improving health system performance. The paper concludes by proposing specific measures of governance determinants and performance and describes the instruments available to collect and interpret them.
Surveillance for Recurrent Head and Neck Cancer Using Positron Emission Tomography

PURPOSE: Earlier detection of head and neck cancer recurrence may improve survival. We evaluated the ability of [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) to detect recurrence in a prospective trial using sequential PET scans. PATIENTS AND METHODS: Serial posttherapy FDG-PET was prospectively performed in 44 patients with stage III or IV head and neck cancer. PET was performed twice during the first posttreatment year (at 2 and 10 months after therapy) and thereafter as needed. After therapy, patients were grouped, based on tissue biopsies, into those who achieved a complete response (CR) and those who had residual disease (RD). Patients who achieved a CR were further grouped into those without evidence of disease and those who had recurrence by 1 year after completion of therapy. Disease status as determined by physical examination (PE), PET, and correlative imaging was compared. RESULTS: Eight patients were lost to follow-up and six had RD after therapy. Of the remaining 30 patients ...
Linear Models: Permutation Methods

Permutation tests of hypotheses about parameters in linear models derive their validity from exchangeability of the errors in the null model. These errors are unobservable but differ from the observable residuals by a constant for any hypothesis that posits a null, reduced parameter model with just an intercept term. For these hypotheses, exact permutation inferences are possible for iid error distributions of any form. Other hypotheses on subsets of parameters in multiple regression models are not exact because the residuals are not exchangeable with equal probability. Several options to improve exchangeability for these hypotheses have been developed and are presented for permutation tests on quantile regression estimates of the linear model. Keywords: least squares regression; linear model; quantile regression; permutation test