cssi/SciSciGPT-SciSciNet huggingface dataset:
Total Syntheses of Secalonic Acids A and D

Total syntheses of the dimeric tetrahydroxanthone natural products secalonic acids A and D are described. Key steps involve kinetic resolution of the tetrahydroxanthone core structure using homobenzotetramisole catalysis and late-stage copper(I)-mediated homodimerization of complex aryl stannane monomers.
A Definition and Illustration of Democratic Leadership

Renewed calls for democracy make it imperative that we understand the nature of democratic leadership. Existing definitions of democratic leadership are inconsistent and inadequate, so this essay provides a clear definition that applies to social groups both large and small. As defined herein, democratic leadership is conceptually distinct from positions of authority; rather, it is defined as the performance of three functions: distributing responsibility among the membership, empowering group members, and aiding the group's decision-making process. Many, most, or all members of a group serve these functions, regularly exchanging the roles of leader and follower. A limited number of practical and moral considerations are identified for assessing the appropriateness of the democratic leadership model for different groups. In addition, the National Issues Forums program is used to illustrate the model, and suggestions are made for future research on democratic leadership.
Ranking sports teams and the inverse equal paths problem

The problem of rank aggregation has been studied in contexts varying from sports, to multi-criteria decision making, to machine learning, to academic citations, to ranking web pages, and to descriptive decision theory. Rank aggregation is the mapping of inputs that rank subsets of a set of objects into a consistent ranking that represents in some meaningful way the various inputs. In the ranking of sports competitors, or academic citations or ranking of web pages the inputs are in the form of pairwise comparisons. We present here a new paradigm using an optimization framework that addresses major shortcomings in current models of aggregate ranking. Ranking methods are often criticized for being subjective and ignoring some factors or emphasizing others. In the ranking scheme here subjective considerations can be easily incorporated while their contributions to the overall ranking are made explicit. The inverse equal paths problem is introduced here, and is shown to be tightly linked to the problem of aggregate ranking “optimally”. This framework is useful in making an optimization framework available and by introducing specific performance measures for the quality of the aggregate ranking as per its deviations from the input rankings provided. Presented as inverse equal paths problem we devise for the aggregate ranking problem polynomial time combinatorial algorithms for convex penalty functions of the deviations; and show the NP-hardness of some forms of nonlinear penalty functions. Interestingly, the algorithmic setup of the problem is that of a network flow problem. We compare the equal paths scheme here to the eigenvector method, Google PageRank for ranking web sites, and the academic citation method for ranking academic papers.
Diffusivity in multiple scattering systems

We consider random flights of point particles inside $n$-dimensional channels of the form $\mathbb{R}^{k} \times \mathbb{B}^{n-k}$, where $\mathbb{B}^{n-k}$ is a ball of radius $r$ in dimension $n-k$. The particle velocities immediately after each collision with the boundary of the channel comprise a Markov chain with a transition probabilities operator $P$ that is determined by a choice of (billiard-like) random mechanical model of the particle-surface interaction at the "microscopic" scale. Our central concern is the relationship between the scattering properties encoded in $P$ and the constant of diffusivity of a Brownian motion obtained by an appropriate limit of the random flight in the channel. Markov operators obtained in this way are {\em natural} (definition below), which means, in particular, that (1) the (at the surface) Maxwell-Boltzmann velocity distribution with a given surface temperature, when the surface model contains moving parts, or (2) the so-called Knudsen cosine law, when this model is purely geometric, is the stationary distribution of $P$. We show by a suitable generalization of a central limit theorem of Kipnis and Varadhan how the diffusivity is expressed in terms of the spectrum of $P$ and compute, in the case of 2-dimensional channels, the exact values of the diffusivity for a class of parametric microscopic surface models of the above geometric type (2).
Simulation of Topological Field Theories¶by Quantum Computers

Quantum computers will work by evolving a high tensor power of a small (e.g. two) dimensional Hilbert space by local gates, which can be implemented by applying a local Hamiltonian H for a time t. In contrast to this quantum engineering, the most abstract reaches of theoretical physics has spawned “topological models” having a finite dimensional internal state space with no natural tensor product structure and in which the evolution of the state is discrete, H≡ 0. These are called topological quantum field theories (TQFTs). These exotic physical systems are proved to be efficiently simulated on a quantum computer. The conclusion is two-fold: 1. TQFTs cannot be used to define a model of computation stronger than the usual quantum model “BQP”. 2. TQFTs provide a radically different way of looking at quantum computation. The rich mathematical structure of TQFTs might suggest a new quantum algorithm.
Spatially adaptive semi-supervised learning with Gaussian processes for hyperspectral data analysis

This paper presents a semi-supervised learning algorithm called Gaussian process expectation-maximization (GP-EM), for classification of landcover based on hyperspectral data analysis. Model parameters for each land cover class are first estimated by a supervised algorithm using Gaussian process regressions to find spatially adaptive parameters, and the estimated parameters are then used to initialize a spatially adaptive mixture-of-Gaussians model. The mixture model is updated by expectation-maximization iterations using the unlabeled data, and the spatially adaptive parameters for unlabeled instances are obtained by Gaussian process regressions with soft assignments. Spatially and temporally distant hyperspectral images taken from the Botswana area by the NASA EO-1 satellite are used for experiments. Detailed empirical evaluations show that the proposed framework performs significantly better than all previously reported results by a wide variety of alternative approaches and algorithms on the same datasets. © 2011 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 4: 358–371, 2011 © 2011 Wiley Periodicals, Inc.
The Impact of Decentralized Data Entry on the Quality of Household Survey Data in Developing Countries: Evidence from a Randomized Experiment in Vietnam

Computers were provided to randomly selected districts participating in a household survey in Vietnam to assess the impact on data quality of entering data within a day or two of completing the interview rather than several weeks later in the provincial capital. Provision of computers had no significant effect on the observed distribution of household expenditures and thus no effect on measured poverty. Provision of computers reduced the mean number of errors per household by 5-23 percent, depending on the type of error. Given the already low rate of errors in the survey, however, the goal of increasing the precision of the estimated mean of a typical variable can be achieved at a much lower cost by slightly increasing the sample size. Provision of additional computers did substantially reduce the time interviewers spent adding up and checking the data in the field, with the value of the time saved close to the cost of purchasing desktop computers
Solving the Kinematics of Planar Mechanisms by Dixon Determinant and a Complex-Plane Formulation

This paper presents a general method for the analysis of any planar mechanism consisting of rigid links connected by revolute and slider joints. The method combines the complex plane formulation of Wampler (1999) with the Dixon determinant procedure of Nielsen and Roth (1999). The result is simple to derive and implement, so in addition to providing numerical solutions, the approach facilitates analytical explorations. The procedure leads to a generalized eigenvalue problem of minimal size. Both input/output problems and the derivation of tracing curve equations are addessed. NOMENCLATURE � Number of kinematic loops. θj e iΘj ,w here Θ j is an angle, in radians. z ∗ Complex conjugate of z.
Probing MACHOs toward the Galactic Bulge

If the massive compact halo object (MACHO) fraction of the Galactic dark halo is f ~ 20%, as suggested by some microlensing experiments, then about 1.2% of lensing events toward the Galactic bulge are due to MACHOs. For the 40% of these that lie nearby (Dl < 4 kpc), measurement of their distance Dl would distinguish them from bulge lenses, while measurement of their transverse velocity vl would distinguish them from disk lenses. Hence, it would be possible to identify about 0.5%(f/20%) of all events as due to MACHOs. I show that a planned experiment using the Space Interferometry Mission (SIM PlanetQuest) could thereby detect 1 or 2 such events. This is at the margin of what is required because of a small but nonnegligible background from spheroid stars.
Speeding Multicast by Acknowledgment Reduction Technique (SMART)

We present a novel feedback protocol for wireless broadcast networks that utilize linear network coding. We consider transmission of packets from one source to many receivers over a single-hop broadcast erasure channel. Our method utilizes a predictive model to request feedback only when the probability that all receivers have completed decoding is significant. In addition, our proposed NACK-based feedback mechanism enables all receivers to request, within a single time slot, the number of retransmissions needed for successful decoding. We present simulation results as well as analytical results that show the favorable scalability of our technique as the number of receivers, file size, and packet erasure probability increase. We also show the robustness of this scheme to uncertainty in the predictive model, including uncertainty in the number of receiving nodes and the packet erasure probability, as well as to losses of the feedback itself. Our scheme, SMART, is shown to perform nearly as well as an omniscient transmitter that requires no feedback. Furthermore, SMART, is shown to outperform current state of the art methods at any given erasure probability, file size, and numbers of receivers.
Lost boys: Why our sons turn violent and how we can save them

Abstract The means children have used to express their frustrations and anxieties has been shaped over the years by the environments in which they live. What was once responded to with words of anger or vandalism is today responded to with threats and the use of weapons. Today's violent children are products of the toxic environment they experience on multiple levels. This paper considers violent behavior in children from a psychosocial perspective and provides six basic tools that should be considered to better understand and address violence: an ecological perspective on human development; the accumulation of risk and opportunity in children; a professional humility about resilience; the inherent temperament of children; rejection; and spirituality.
The dynamics of health behavior sentiments on a large online social network

Modifiable health behaviors, a leading cause of illness and death in many countries, are often driven by individual beliefs and sentiments about health and disease. Individual behaviors affecting health outcomes are increasingly modulated by social networks, for example through the associations of like-minded individuals - homophily - or through peer influence effects. Using a statistical approach to measure the individual temporal effects of a large number of variables pertaining to social network statistics, we investigate the spread of a health sentiment towards a new vaccine on Twitter, a large online social network. We find that the effects of neighborhood size and exposure intensity are qualitatively very different depending on the type of sentiment. Generally, we find that larger numbers of opinionated neighbors inhibit the expression of sentiments. We also find that exposure to negative sentiment is contagious - by which we merely mean predictive of future negative sentiment expression - while exposure to positive sentiments is generally not. In fact, exposure to positive sentiments can even predict increased negative sentiment expression. Our results suggest that the effects of peer influence and social contagion on the dynamics of behavioral spread on social networks are strongly content-dependent.
Light distributions on the retina: relevance to macular pigment photoprotection.

Light exposure has been implicated in age-related macular degeneration (AMD). This study was designed to measure cumulative light distribution on the retina to determine whether it peaked in the macula. An eye-tracker recorded the subject's field of view and pupil size, and superimposed the gaze position. Fifteen naive subjects formed a test group; 5 formed a control group. In phase 1, all subjects viewed a sequence of photographic images. In phase 2, the naive subjects observed a video; in phase 3, they performed computer tasks; in phase 4, the subjects walked around freely. In phase 1, control subjects were instructed to gaze at bright features in the field of view and, in a second test, at dark features. Test group subjects were allowed to gaze freely for all phases. Using the subject's gaze coordinates, we calculated the cumulative light distribution on the retina. As expected for control subjects, cumulative retinal light distributions peaked and dipped in the fovea when they gazed at bright or dark features respectively in the field of view. The light distribution maps obtained from the test group showed a consistent tendency to peak in the macula in phase 3, a variable tendency in phase 4, but little tendency in phases 1 and 2. We conclude that a tendency for light to peak in the macula is a characteristic of some individuals and of certain tasks. In these situations, risk of AMD could be increased but, at the same time, mitigated by the presence of macular carotenoids.
A new method to extend dimercaptan or diamine chains with aminopropyl units using 3-bromo-N-tritylpropanamine

Abstract Dimercaptans and diamines react with 3-bromo-N-tritylpropanamine to give the corresponding N,N′-ditrityldithia and N,N′-ditritylpolyaza compounds in yields of 50–80%. The trityl protecting groups are readily removed in acid. These reactions make possible the synthesis of a number of new α-ω-diamino compounds needed for the synthesis of new dithiadiaza, di- and polyaza macrocyclic ligands.
Free point processes and free extreme values

We continue here the study of free extreme values begun in Ben Arous and Voiculescu (Ann Probab 34:2037–2059, 2006). We study the convergence of the free point processes associated with free extreme values to a free Poisson random measure (Voiculescu in Lecture notes in mathematics. Springer, Heidelberg, pp. 279–349, 1998; Barndorff-Nielsen and Thorbjornsen in Probab Theory Relat Fields 131:197–228, 2005). We relate this convergence to the free extremal laws introduced in Ben Arous and Voiculescu (Ann Probab 34:2037–2059, 2006) and give the limit laws for free order statistics.
Organometallic chemistry at the threshold of a new millennium. Retrospect and prospect

The evolution of organometallic chemistry during the second half of the 20 th cen- tury has transformed chemical science and technology to a degree and in ways that have rarely been matched throughout the history of chemistry. These include the discovery of rad- ically new types of chemical compounds; novel structures and bonding modes; unprecedent- ed reactivity patterns; unsuspected roles of organometallic chemistry in biology; powerful new synthetic methodologies; new materials; and whole new classes of catalysts and catalyt- ic processes of extraordinary versatility and selectivity. The impact of these developments, which still are unfolding, has been truly revolutionary. Some milestones in this remarkable chapter of chemical history, as well as challenges and opportunities confronting organometal- lic chemistry today, will be examined.
Theoretical investigation of totally asymmetric exclusion processes on lattices with junctions

Totally asymmetric simple exclusion processes on lattices with junctions, where particles interact with hard core exclusion and move on parallel lattice branches that at the junction combine into a single lattice segment, are investigated. A simple approximate theory, that treats the correlations around the junction position in a mean-field fashion, is developed in order to calculate stationary particle currents, density profiles and a phase diagram. It is shown that there are three possible stationary phases depending on the state of each of the lattice branches. At first-order phase boundaries, where the density correlations are important, a modified phenomenological domain wall theory, that accounts for correlations, is introduced. Extensive Monte Carlo computer simulations are performed to investigate the system, and it is found that they are in excellent agreement with theoretical predictions. The application of the theoretical method for other inhomogeneous asymmetric simple exclusion processes is outlined.
Counterglow from the Earth-Moon libration points

Abstract Results from the OSO-6 Rutgers Zodiacal Light Analyzer experiment show photometric perturbations above the background in the anti-Sun line of sight. Sixteen successive lunations were examined, and the accumulated perturbations show a maximum value in the direction of the L4 and L5 Earth-Moon libration points. This is interpreted as a counterglow from a cloud of particles at the libration points. The average brightness of these libration clouds is 20 S10 Vis. The average angular size of the libration clouds is approximately 6 degrees. Their position varies from one lunation to the next, within an ellipsoidal zone centered on the libration point direction, with its semi-major axis, of approximately 6 degrees, nominally in the ecliptic and its semi-minor axis, of approximately 2 degrees perpendicular to the ecliptic. The position of these clouds with respect to the Lagrangian L4 and L5 points, is towards the Moon in the northern summer and away from the Moon in the northern winter.
THE EFFECTS AND DETERMINANTS OF TRAINING

Job training is an important subject for discussion, since the skills on which an economy depends are largely created by the process of training. Various theories, especially the human capital model, have focussed attention on skill aquisition through training as a central determinant of individual economic success. What little empirical literature exists on this subject concentrates almost entirely on the effects of individual, government sponsored, special training programmes for those not currently at work. However, the vast majority of training experiences occur whilst the individual is in employment. This study documents the extent of vocational training, taking place both on and off the job, and examines its effects and determinants. The data source is the National Training Survey (NTS) which provides comprehensive details of the training records of more than 50,000 men and women in Great Britain. (For details see Manpower Services Commission, 1976). This data has previously been analysed for men only by Metcalf and Nickell (1982) and by Nickel (1982).
Independent Prognostic Significance of Gene Expression Profile Class and Largest Basal Diameter of Posterior Uveal Melanomas.

Purpose To determine whether any conventional clinical prognostic factors for metastasis from uveal melanoma retain prognostic significance in multivariate models incorporating gene expression profile (GEP) class of the tumor cells. Design Prospective, interventional case series with a prognostic model. Methods Single-institution study of GEP testing and other conventional prognostic factors for metastasis and metastatic death in 299 patients with posterior uveal melanoma evaluated by fine-needle aspiration biopsy (FNAB) at the time of or shortly prior to initial treatment. Univariate prognostic significance of all evaluated potential prognostic variables (patient age, largest linear basal diameter of tumor [LBD], tumor thickness, intraocular location of tumor, melanoma cytomorphologic subtype, and GEP class) was performed by comparison of Kaplan-Meier event rate curves and univariate Cox proportional hazards modeling. Multivariate prognostic significance of combinations of significant prognostic factors identified by univariate analysis was performed using step-up and step-down Cox proportional hazards modeling. Results GEP class was the strongest prognostic factor for metastatic death in this series. However, tumor LBD, tumor thickness, and intraocular tumor location also proved to be significant individual prognostic factors in this study. On multivariate analysis, a 2-term model that incorporated GEP class and largest basal diameter was associated with strong independent significance of each of the factors. Conclusion Although GEP test is the most robust prognostic indicator in uveal melanoma and early studies of mostly larger tumors found that no clinicopathologic factors had significant prognostic value independent of GEP, our single-center study, which included a substantial proportion of smaller tumors, showed that both GEP and LBD of the tumor are independent prognostic factors for metastasis and metastatic death in multivariate analysis.
Spectroscopic and electrochemical studies of electrochromic hydrated nickel oxide films

The electrochromic properties of hydrated nickel oxide thin films electrochemically deposited by anodization onto doped tin-oxide-coated glass have been studied by transmittance measurements, cyclic voltammetry, Fourier-transform infrared spectroscopy, and ion-backscattering spectrometry. The spectral transmittance is reported for films switched in both the bleached and colored states. The photopic transmittance Tp can be switched from Tp(bleached) = 0.77 to Tp(colored) = 0.21, and the solar transmittance Ts can be switched from Ts(bleached) = 0.73 to Ts(colored) = 0.35. Also reported is the near-infrared transmittance TNIR, which was found to switch from TNIR(bleached) = 0.72 to TNIR(colored) = 0.55 with a film thickness of 50 nm. The bleached condition is noted to have very low solar absorption in both the visible and solar regions. Ion-backscattering spectrometry was performed on the hydrated nickel oxide film, yielding a composition of NiO1.0 (dehydrated). Cyclic voltammetry showed that, for films in the bleached or colored state, the reversible reaction is Ni(OH)2 ↔ NiOOH + H+ + e−. Voltammetry also showed that the switching of the film is controlled by the diffusion of protons, where OH− plays a role in the reaction mechanism. Analysis of the hydrated nickel-oxide thin films by Fourier-transform infrared spectroscopy revealed that both the bleached and colored states contain lattice water and hydroxyl groups. The surface hydroxyl groups play an important role in the coloration and bleaching of the anodically deposited nickel oxide thin films.
Carboxylation and Esterification of Functionalized Arylcopper Reagents

Functionalized arylcopper reagents have been produced in good yields at 25 °C from activated copper and the corresponding functionalized aryl iodides without the need of traditional organolithium or Grignard precursors. These organocopper compounds will undergo carboxylation with CO2 to form the corresponding copper benzoates. In turn, these salts can be acidified to produce the functionalized aryl acids or treated with appropriate alkyl halides in the presence of a dipolar aprotic solvent to generate the corresponding aryl esters. This methodology permits the formation of functionalized organic acids and esters that could not be generated by the carboxylation of organomagnesium compounds.
Nitrene transfer reactions catalyzed by gold complexes.

We report here the first gold-catalyzed nitrene transfer reaction. A gold(I) compound, supported by 4,4‘,4‘ ‘-tri-tert-butyl-2,2‘:6‘,2‘ ‘-terpyridine (tBu3tpy) as the ligand, efficiently catalyzes olefin aziridination with the use of the commercially available oxidant PhI(OAc)2 and sulfonamides. This system also mediates carbene insertion into benzene.
Dynamics of viscous coalescing droplets in a saturated vapor phase

The dynamics of two liquid droplets coalescing in their saturated vapor phase are investigated by Lattice Boltzmann numerical simulations. Attention is paid to the effect of the vapor phase on the formation and growth dynamics of the liquid bridge in the viscous regime. We observe that the onset of the coalescence occurs earlier and the expansion of the bridge initially proceeds faster when the coalescence takes place in a saturated vapor compared to the coalescence in a non-condensable gas. We argue that the initially faster evolution of the coalescence in the saturated vapor is caused by the vapor transport through condensation during the early stages of the coalescence.
Characterizing the elements of Earth's radiative budget: Applying uncertainty quantification to the CESM

Abstract Understanding and characterizing sources of uncertainty in climate modeling is an important task. Because of the ever increasing sophistication and resolution of climate modeling it is increasingly important to develop uncertainty quantification methods that minimize the computational cost that occurs when these methods are added to climate modeling. This research explores the application of sparse stochastic collocation with polynomial edge detection to characterize portions of the probability space associated with the Earth's radiative budget in the Community Earth System Model (CESM). Specifically, we develop surrogate models with error estimates for a range of acceptable input parameters that predict statistical values of the Earth's radiative budget as derived from the CESM simulation. We extend these results in resolution from T31 to T42 and in parameter space increasing the degrees of freedom from two to three.
Semismooth Newton Coordinate Descent Algorithm for Elastic-Net Penalized Huber Loss Regression and Quantile Regression

ABSTRACTWe propose an algorithm, semismooth Newton coordinate descent (SNCD), for the elastic-net penalized Huber loss regression and quantile regression in high dimensional settings. Unlike existing coordinate descent type algorithms, the SNCD updates a regression coefficient and its corresponding subgradient simultaneously in each iteration. It combines the strengths of the coordinate descent and the semismooth Newton algorithm, and effectively solves the computational challenges posed by dimensionality and nonsmoothness. We establish the convergence properties of the algorithm. In addition, we present an adaptive version of the “strong rule” for screening predictors to gain extra efficiency. Through numerical experiments, we demonstrate that the proposed algorithm is very efficient and scalable to ultrahigh dimensions. We illustrate the application via a real data example. Supplementary materials for this article are available online.
Transverse Combustion Instability in a Rectangular Rocket Motor

A computational analysis of transverse acoustic instability is presented for an experimental combustion chamber with rectangular cross section. The analysis is shown to be efficient and accurate. The governing equations are solved on multiple, coupled grids, which are two-dimensional in the combustion chamber and nozzle and one-dimensional in the injector port. Thus, they allow for a fast simulation, even in a serial run. Because of the lengthscale difference, the jet flame behavior at the injectors (including effects of turbulence) can be decoupled from the acoustic effects and solved on a local grid for each jet flame emerging from an injector. Wave propagation through the injector feed ports is evaluated on additional, one-dimensional grids for each injector port. The overall algorithm is used to simulate the Purdue seven-injector rocket engine; good quantitative agreement between simulations and experiment is achieved. All simulations that are predicted to be unconditionally unstable are confirmed by ...
Top- $k$ Preferences in High Dimensions

Given a set of objects $\mathcal {O}$ , each with $d$ numeric attributes, a top- $k$ preference scores these objects using a linear combination of their attribute values, where the weight on each attribute reflects the interest in this attribute. Given a query preference $q$ , a top- $k$ query finds the $k$ objects in $\mathcal {O}$ with highest scores with respect to $q$ . Given a query object $o$ and a set of preferences $\mathcal {Q}$ , a reverse top- $k$ query finds all preferences $q\in \mathcal {Q}$ for which $o$ becomes one of the top $k$ objects with respect to $q$ . Previous solutions to these problems are effective only in low dimensions. In this paper, we develop a solution for much higher dimensions (up to high tens), if many preferences exhibit sparsity —i.e., each specifies non-zero weights for only a handful (say $5$ - $7$ ) of attributes (though the subsets of such attributes and their weights can vary greatly). Our idea is to select carefully a set of low-dimensional core subspaces to “cover” the sparse preferences in a workload. These subspaces allow us to index them more effectively than the full-dimensional space. Being multi-dimensional, each subspace covers many possible preferences; furthermore, multiple subspaces can jointly cover a preference, thereby expanding the coverage beyond each subspace’s dimensionality. Experimental evaluation validates our solution’s effectiveness and advantages over previous solutions.
THE IMPORTANCE OF ASYMMETRIC THIGH CREASES AS THE SOLE REFERRAL COMPLAINT IN DEVELOPMENTAL DYSPLASIA OF THE HIP

A study to assess the clinical importance of asymmetric thigh creases as the sole clinical sign in the diagnosis of developmental dysplasia of the hip. METHOD All consultant clinic letters have been saved on a hospital hard drive since 1999. This drive was searched for the terms “thigh crease” and “skin crease”. Irrelevant letters and referral letters describing factors that would indicate screening in our unit were excluded leaving those with the sole referral complaint of asymmetric thigh creases (ATC). We also reviewed the original referrals of developmental dysplasia of the hip (DDH) patients managed by open or closed reduction. These patients were identified through operative coding. All available hard copy notes were reviewed and patients with neuromuscular conditions or longitudinal deficiency were excluded. Results were inputted into an Excel spreadsheet and analysed by a statistician at the University of Sheffield assuming a background population incidence for DDH of 1 in 1000. RESULTS 399 computer files containing the search terms were identified. Many contained whole clinics of patient letters. After exclusions we identified 229 patients with the sole referral complaint of ATC. Three of the 229 patients had DDH, which was not statistically significant (p=0.107). The majority of the normal patients had radiological investigations. Hard copy notes were available and relevant for 130 of the 289 operatively managed patients, of whom one was initially referred with the sole complaint of ATC. Orthopaedic specialist examination demonstrated all four patients initially referred with only ATC had decreased abduction and shortening. CONCLUSION We suggest if the primary health care professional is not confident to exclude DDH in the patient with ATC there is justification for referral, but in the absence of other clinical features or risk factors in the orthopaedic consultation there is no need for further investigation or follow up.
Autoreducibility of NP-Complete Sets

We study the polynomial-time autoreducibility of NP-complete sets and obtain separations under strong hypotheses for NP. Assuming there is a p-generic set in NP, we show the following: - For every k >= 2, there is a k-T-complete set for NP that is k-T autoreducible, but is not k-tt autoreducible or (k-1)-T autoreducible. - For every k >= 3, there is a k-tt-complete set for NP that is k-tt autoreducible, but is not (k-1)-tt autoreducible or (k-2)-T autoreducible. - There is a tt-complete set for NP that is tt-autoreducible, but is not btt-autoreducible. Under the stronger assumption that there is a p-generic set in NP cap coNP, we show: - For every k >= 2, there is a k-tt-complete set for NP that is k-tt autoreducible, but is not (k-1)-T autoreducible. Our proofs are based on constructions from separating NP-completeness notions. For example, the construction of a 2-T-complete set for NP that is not 2-tt-complete also separates 2-T-autoreducibility from 2-tt-autoreducibility.
Enhanced oil recovery water requirements

Water requirements for enhanced oil recovery (EOR) are thoroughly evaluated using publicly available information, data from actual field applications and information provided by knowledgeable EOR technologists in fourteen major oil companies. Water quanity and quality requirements are estimated for individual EOR processes (steam drive,in situ combustion and carbon dioxide, micellar-polymer, polymer and caustic flooding) in those states and specific geographical locations where these processes will likely play major roles in future petroleum production by the year 2000. The estimated quantity requirements represent thetotal water needed from all sources, e.g. aquifers, lakes and produced water. A reduction in these quantities can be achieved by reinjecting all of the produced water potentially available for recyle, e.g. some is lost in oil and water separation and water treatment processes, in the oil recovery method. For injection water quality requirements, it is noted that not all of the water used for EOR needs to be fresh. The use oftreated produced water can significantly reduce the quantities of fresh water that would be sought from other sources. Although no major EOR project to date has been abandoned because of water supply problems, competing regional uses for water, drought situations, and scarcity of high quality, e.g. low total dissolved solids, surface water and ground water could be impediments to certain projects in the near future.
Efficient high-order analysis of bowtie nanoantennas using the locally corrected Nyström method

It is demonstrated that the Locally Corrected Nystrom (LCN) method is a versatile and numerically efficient computational method for the modeling of scattering from plasmonic bowtie nanoantennas. The LCN method is a high-order analysis method that can provide exponential convergence. It is straightforward to implement, accurate and computationally efficient. To the best of the author's knowledge, the high-order LCN is here applied for the first time to 3D nanostructures. Numerical results show the accuracy and efficiency of the LCN applied to the electromagnetic analysis of nanostructures.
Bayesian Estimation of Bipartite Matchings for Record Linkage

ABSTRACTThe bipartite record linkage task consists of merging two disparate datafiles containing information on two overlapping sets of entities. This is nontrivial in the absence of unique identifiers and it is important for a wide variety of applications given that it needs to be solved whenever we have to combine information from different sources. Most statistical techniques currently used for record linkage are derived from a seminal article by Fellegi and Sunter in 1969. These techniques usually assume independence in the matching statuses of record pairs to derive estimation procedures and optimal point estimators. We argue that this independence assumption is unreasonable and instead target a bipartite matching between the two datafiles as our parameter of interest. Bayesian implementations allow us to quantify uncertainty on the matching decisions and derive a variety of point estimators using different loss functions. We propose partial Bayes estimates that allow uncertain parts of the bipartite...
Commentary: The nature of cancer research

Author(s): Frank, Steven A | Abstract: Cancer research reflects an implicit conflict. On the one hand, there is an overwhelming desire to control the disease. We all wish that. On the other hand, we would like to understand why cancer follows so many clearly defined yet puzzling patterns. Why is there such regularity in the rates of progression? Why do different tissues vary so much? There should, of course, be no conflict between control and understanding. But the history of cancer research seems to say that those different goals remain oddly estranged. Peto's 1977 article locates the seeds of this conflict most clearly. He describes what is still the most powerful theoretical perspective for analyzing the causes of cancer. He presents many key unsolved puzzles within that context. He also says why most cancer researchers are not interested in these fundamental issues. The subsequent decades of research grew around this rift, blindly, in the way that research disciplines often grow. Let us revisit Peto, almost 40 years ago. We can learn much about the current nature of cancer research.
Does Dutch Disease Hit Mongolia

Mongolia is a comparatively small country in the world and the limited domestic demand makes it rely on the trade with other countries. In recent years, Mongolia’s extensive mineral deposits and attendant growth in mining-sector activities have transformed Mongolia’s economy which traditionally has been dependent on herding and agriculture. An equilibrium displacement model based on the macro-economy conditions in Mongolia is conducted to test whether the development of the mining sector has come at the expense of the agricultural sector, as suggested by the “Dutch Disease” hypothesis. Base on the classic economic model developed by Corden and Neary (1982) to describe Dutch Disease: in an open small economy (Mongolia), the booming tradable sector (mining) would suppress the lagging or non-booming sector (agriculture). How the booming mining industry affects the traditional agriculture industry (including grazing) is the main point of this paper.
Monetary policy in open economies: Practical perspectives for pragmatic central bankers

This paper reviews and interprets some of the key policy implications that flow from a class of DSGE models for optimal monetary policy in the open economy. The framework suggests that good macroeconomic outcomes in open economies are possible by focusing inflation targeting that is implemented by a Taylor type rule, a rule that in equilibrium is reflected in the exchange rate as an asset price. Optimal monetary policy will not be able deliver a stationary (‘stable’) nominal exchange rate – let alone a fixed exchange rate or one that remains inside a target zone – because, absent a commitment device, optimal monetary can’t deliver a stationary domestic price level. Another feature in the data for inflation targeting countries that is consistent with monetary policy via Taylor type rule is that it will tend push the nominal exchange rate in the opposite direction from PPP in response to an ‘inflation’ shock—the ‘bad news god news’ result of Clarida and Waldman (2008. Is Bad News about Inflation Good News for the Exchange Rate. In: John Campbell, (Ed.), Asset Prices and Monetary Policy, Chicago: University of Chicago Press), Clarida and Waldman (2014. Bad News About Inflation is Good News for the Nominal Exchange Rate Under Optimal Monetary Policy: DSGE Theory and a Decade of Empirical Evidence). This is so even though in the long run of these models the nominal exchange rate must in expectation obey PPP.
Restoring Sinus Rhythm Improves Baroreflex Function in Patients With Persistent Atrial Fibrillation.

Background Studies have suggested that patients with atrial fibrillation (AF) have impairment in the baroreflex. It is not clear whether these findings are the result of the associated comorbid conditions or the arrhythmia itself. We hypothesized that AF is associated with impairment in baroreflex function and that the arrhythmia itself is a contributing factor. Methods and Results Twenty‐four patients with persistent AF referred for cardioversion were enrolled. A second group of patients with no history of AF matched for age and left ventricular ejection fraction was identified and served as the control group. In the AF group, baroreflex gain (BRG) was measured on the day of cardioversion (Day 1) and again at 30 days post‐cardioversion (Day 30) in patients who remained in sinus rhythm (SR). The clinical characteristics of patients with AF were not different than those of the control group. The mean BRG in the AF group on Day 1 was significantly lower than the mean BRG of the control group (5.2±3.6 versus 10.8±5.5 ms/mm Hg, P <0.05). Ten patients experienced AF recurrence before the 30‐day follow‐up and 14 patients remained in SR. In the group that remained in SR, BRG increased from 4.1±3.7 ms/mm Hg on Day 1 to 7.0±6.0 ms/mm Hg on Day 30 ( P <0.01). Conclusion We have shown that AF is associated with impairment of the baroreflex and that restoration of SR improves BRG. Our data suggest that AF might be a contributing factor to the observed impairment in BRG and that restoring SR might help improve baroreflex function.
Spillovers from universities: Evidence from the land-grant program

Abstract This paper estimates the short- and long-run effects of universities on geographic clustering of economic activity, labor market composition and local productivity and presents evidence of local spillovers from universities. I treat the designation of land-grant universities in the 1860s as a natural experiment after controlling for the confounding factors with a combination of synthetic control methods and event-study analyses. Three key results are obtained. First, the designation increased local population density by 6 percent within 10 years and 45 percent in 80 years. Second, the designation did not change the relative size of local manufacturing sector. Third, the designation enhanced local manufacturing output per worker by $2136 (1840 dollars; 57 percent) in 80 years while the short-run effects were negligible. This positive effect on the productivity in non-education sectors suggests the existence of local spillovers from universities. Over an 80-year horizon, my results indicate that the increase in manufacturing productivity reflects both the impact of direct spillovers from universities and general agglomeration economies that arise from the increase in population.
Russia's potential to increase grain production by expanding area

Since 2000, Russia has substantially increased grain production and exports. The grain output growth has come from a rise in yields rather than area. After falling heavily during the 1990s, grain area stabilized during the 2000s and has remained flat, at about two-thirds the level of the late Soviet period. Using data on the regional structure of Russian grain production costs, this article examines the country’s potential to increase grain output further by returning the lost grain area to production. The analysis finds that if grain area were to grow beyond a certain level, one that is still well below the level of the late Soviet period, production costs would rise steeply. Therefore, any major expansion in grain area would require that world grain prices rise considerably beyond their level in the early 2010s to cover the high marginal costs of production.
How to Homologate Your Sugar: Synthetic Approaches to Septanosyl Containing Carbohydrates

Seven-membered ring “septanose” sugars have been used as surrogates of pyranoses in biochemical investigations. Septanoses are homologs of pyranoses in the same way that beta amino acids are for alpha amino acids or hexose nucleosides for deoxyribose nucleosides. Methods for their synthesis have undergone significant development recently, following two complementary strategies. In one, glycals are cyclopropanated which are later opened in addition reactions with nucleophiles. The other follows traditional glycosylation strategies where electrophilic donors are prepared and reacted with nucleophiles. Unsaturated seven membered ring oxepines play a key role in both of the approaches, which are highlighted.
MR and CT Evaluation of Intracranial Sarcoidosis

Fourteen patients with CNS manifestations of neurosarcoidosis were evaluated by MR imaging and CT. Evaluations were done on a 0.5-T superconductive magnet with T1- and T2-weighted sequences. CT with contrast was obtained in all patients. The granulomatous lesions were classified by location into basilar, convexity, intrahemispheric, and periventricular white-matter involvement. Hydrocephalus with or without an associated lesion was also noted. MR determined the presence of disease in all patients (100%), but was less accurate than CT in depicting disease in two patients (14%). CT determined the presence of disease in 12 patients (85%) and was less accurate than MR in delineating hypothalamic involvement in two patients and periventricular white-matter disease in three patients. There was great variability in the appearance of intracranial sarcoidosis on MR. Three patients had lesions that were isointense or hypointense (relative to cerebral cortex) on both T1- and T2-weighted images while nine patients had lesions that were hyperintense on T2-weighted images. Convexity involvement and hydrocephalus were well documented by both CT and MR. These results indicate that both MR and CT are helpful in fully evaluating a patient with suspected intracranial sarcoidosis.
Polycrystalline Silicon Films for Microelectromechanical Devices

Polycrystalline silicon is the most widely used structural material for surface micro-machined microelectromechanical systems (MEMS). There are many advantages to using thick polysilicon films; however, due to process equipment limitations, these devices are typically fabricated from polysilicon films less than 3 µm thick. In this work, microelectromechanical test structures were designed and processed from thick (up to 10 µm) in situ boron-doped polysilicon films. The elastic modulus of these films was about 150 GPa, independent of film thickness. The thermal oxidation of the polysilicon induced a compressive stress into the top surface of the films, which was detected as a residual stress in the polysilicon after the device fabrication was complete.