cssi/SciSciGPT-SciSciNet huggingface dataset:
Field splitting problems in intensity-modulated radiation therapy

Intensity-modulated radiation therapy (IMRT) is a modern cancer treatment technique that delivers prescribed radiation dose distributions, called intensity maps (IMs), to target tumors via the help of a device called the multileaf collimator (MLC). Due to the maximum leaf spread constraint of the MLCs, IMs whose widths exceed a given threshold cannot be delivered as a whole, and thus must be split into multiple subfields. Field splitting problems in IMRTnormally aim to minimize the total beam-on time (i.e., the total time when a patient is exposed to actual radiation during the delivery) of the resulting subfields. In this paper, we present efficient polynomial time algorithms for two general field splitting problems with guaranteed output optimality. Our algorithms are based on interesting observations and analysis, as well as new techniques and modelings. We formulate the first field splitting problem as a special integer linear programming (ILP) problem that can be solved optimally by linear programming due to its geometry; from an optimal integer solution for the ILP, we compute an optimal field splitting by solving a set of shortest path problems on graphs. We tackle the second field splitting problem by using a novel path-sweeping technique on IMs.
Fragmentation in simple trade models

Abstract This paper examines the effects of “fragmentation,” defined as the splitting of a production process into two or more steps that can be undertaken in different locations but that lead to the same final product. Introducing the possibility of fragmentation into simple theoretical models of international trade, the paper finds the effects of fragmentation on national welfare, on patterns of specialization and trade, and on factor prices. Models examined include the Ricardian Model and the Heckscher-Ohlin Model, both for small open economies and for a two-country world. Results are as follows: 1. If fragmentation does not change the prices of goods, then it must increase the value of output of any country where it occurs and that of the world. 2. If fragmentation does change prices, then fragmentation can lower the welfare of a country by turning its terms of trade against it. 3. Even in a country that gains from fragmentation, it is possible (but not necessary) that some factor owners within that country will lose. 4. To the extent that factor prices are not equalized internationally in the absence of fragmentation, fragmentation may be a force toward factor price equalization.
Capturing the value of public land for urban infrastructure : centrally controlled landholdings

Government entities in India hold large amounts of public land. Their landholdings include some of the most valuable property in the country. Parts of this patrimony lie vacant or underutilized. Public sector bodies also own large blocs of land that sometimes stand in the way of efficient completion of urban infrastructure networks. At the same time, urban India is deficient in basic infrastructure -- both network infrastructure needed to support economic growth and urban service infrastructure needed to meet basic household needs like water supply, waste removal, and transportation. This condition raises fundamental questions. Are some of government landholdings "surplus" or not needed for service provision? If so, can their economic value be captured to help finance infrastructure investment? This report aims to document evolving government policies toward pubic land management. It examines how active public entities are in identifying "surplus" lands and attempting to monetize them. Public bodies in India have proved reluctant to surrender landholdings. The report therefore considers practical alternatives that have emerged, such as land trading among public institutions. Land exchange can clear the way for completion of important urban infrastructure projects, without requiring public landowners to declare their property "surplus" and suitable for market disposition.
Principles of Financial Economics

This second edition provides a rigorous yet accessible graduate-level introduction to financial economics. Since students often find the link between financial economics and equilibrium theory hard to grasp, less attention is given to purely financial topics, such as valuation of derivatives, and more emphasis is placed on making the connection with equilibrium theory explicit and clear. This book also provides a detailed study of two-date models because almost all of the key ideas in financial economics can be developed in the two-date setting. Substantial discussions and examples are included to make the ideas readily understandable. Several chapters in this new edition have been reordered and revised to deal with portfolio restrictions sequentially and more clearly, and an extended discussion on portfolio choice and optimal allocation of risk is available. The most important additions are new chapters on infinite-time security markets, exploring, among other topics, the possibility of price bubbles.
Stress-Testing Croatian Households with Debt : Implications for Financial Stability

The purpose of this paper is to stress test the resilience of Croatian households with debt to economic shocks. The shocks not only impact a household's welfare, but also increase the probability of loan default. As a result, there is a direct link between these stress-testing exercises and financial stability risks. The authors find that very few households are at risk as a result of the shocks experienced over the past few years; new vulnerable households represent about 2 percent of all households, 6 percent of households with debt, and 2-3 percent of aggregate banking system assets. This suggests that household over-indebtedness in Croatia is unlikely to become a drag on aggregate economic activity and that financial stability risks remain manageable. One caveat should be noted. Some 27-31 percent of households with debt, representing 8-9 of banking system assets, are vulnerable even before being subjected to an economic shock. Since NPLs were low before the global financial crisis, it can be argued that banks knew something about some of these households that is not captured by household budget surveys. It follows that the calculations in this paper should primarily focus on the increased vulnerability of households as a result of shocks and are likely to represent an upper bound to the financial stability risks faced by Croatia on account of household indebtedness.
NASA-Dod Lead-Free Electronics Project

In response to concerns about risks from lead-free induced faults to high reliability products, NASA has initiated a multi-year project to provide manufacturers and users with data to clarify the risks of lead-free materials in their products. The project will also be of interest to component manufacturers supplying to high reliability markets. The project was launched in November 2006. The primary technical objective of the project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: - Packages (e.g., TSOP, BOA, PDIP) assembled and reworked with solder interconnects consisting of lead-free alloys - Packages (e.g., TSOP, BOA, PDIP) assembled and reworked with solder interconnects consisting of mixed alloys, lead component finish/lead-free solder and lead-free component finish/SnPb solder.
Equivalence of domains with isomorphic semigroups of endomorphisms

For two bounded domains Ω 1 , Ω 2 in C whose semigroups of analytic endomorphisms E(Ω 1 ), E(Ω 2 ) are isomorphic with an isomorphism φ: E(Ω 1 ) → E(Ω 2 ), Eremenko proved in 1993 that there exists a conformal or anticonformal map ψ: Ω 1 → Ω 2 such that φf = ψ o f o ψ -1 , for all f ∈ E(Ω 1 ). In the present paper we prove an analogue of this result for the case of bounded domains in C n .
Medicine wheels, sun circles, and the magic of world center shrines.

Explanations of the function of Plains medicine wheels and the Big Horn medicine wheel in particular are com pared to known functions of the boulder outline on Chicoma Mountain in New Mexico known as an earth navel or world center. The variant explanations for Plains medicine wheels are shown to be largely noncontra dictory and consistent with the uses and symbolic associations of "world centers."
Permanent low-activity iodine-125 implants for cerebral metastases.

Beginning in 1987, selected patients with metastatic braintumors were treated with permanent implants of low-activityradioactive iodine-125 (125I) seeds. These patients underwent craniotomy,gross total resection of the metastatic lesion, andplacement of the seeds. In general, criteria fortreatment included the presence of a recurrent tumorwith a volume too large to permit radiosurgery,and a Karnofsky Performance Score of 70 orhigher. Thirteen patients underwent 14 implant procedures; allreceived external whole-brain radiotherapy. Implant dose ranged from43 Gy to 132 Gy, with a meanof 83 Gy. Survival after implantation ranged from2 weeks to almost 9 years, with amedian of 9 months. Clinical and radiographic localcontrol was obtained in 9 patients. Two patientsdied of acute, postoperative complications within a monthof implantation, so no information regarding tumor controlis available for them. Late complications included abone flap infection in one patient and aCSF leak in another; both were treated withoutfurther sequelae. These results demonstrate that permanent 125I implants canresult in good survival and quality of life,and occasionally can yield long-term survival. Potentially, itis a cost-effective treatment in that a separateprocedure for stereotactic implantation or radiosurgery is notneeded, as is the case with the useof temporary high-activity seeds. The permanent implantation itselfadds less than 10 minutes to the craniotomy,and the risk of symptomatic radiation necrosis islow. We recommend consideration of this procedure inpatients harboring large, recurrent metastatic tumors that requirefurther surgery.
The Path of Carbon in Photosynthesis, XV. Ribulose and Sedoheptulose

The intermediates of carbon dioxide reduction by plants include phosphorylated derivatives of hydroxy acids and sugars. Their identification becane possible when the use of labeled carbon dioxide permitted discrimination between the earliest products and the many other components of photosynthetic tissues. A number of compounds were identified by virtue of the chemical and physical properties of the radioactive compounds in tracer amounts and by direct comparison of these properties with those of suspected known metabolic intermediates. It became apparent that several labeled compounds found in short exposures to radioactive carbon dioxide were not substances previously identified as metabolic intermediates. Two phosphate esters in particular were observed in the products of the first few seconds of steady-state photosynthesis by all the photosynthetic microorganisms and higher plants examined in this laboratory. These esters have been isolated by paper chromatography in tracer quantities and enzymatically hydrolyzed to give two sugars, ribulose and sedoheptulose. This paper contains a description of the chemical identification of these sugars and some observations and suggestions regarding the function of their esters. The general importance of these compounds in photosynthesis was surmized before their identification. The products of photosynthesis with C{sup 14}O{sub 2} by each plant included phosphate estersmore » of the same two then unknown compounds in addition to those of the expected glucose, fructose, dihydroxyacetone and glyceric acid. As the time of steady-state photosynthesis in C{sup 14}O{sub 2} decreased, the fractions of total fixed radiocarbon in the esters of the two unidentified compounds increased.« less
COHOMOLOGY OF UNIFORMLY POWERFUL p-GROUPS

In this paper we will study the cohomology of a family of p-groups associated to Fp-Lie algebras. More precisely we study a category BGrp of p-groups which will be equivalent to the category of Fp-bracket algebras (Lie algebras minus the Jacobi identity). We then show that for a group G in this category, its Fp-cohomology is that of an elementary abelian p-group if and only if it is associated to a Lie algebra. We then proceed to study the exponent of H � (G; Z) in the case that G is as- sociated to a Lie algebra L. To do this, we use the Bockstein spectral sequence and derive a formula that gives B � 2 in terms of the Lie algebra cohomologies of L. We then expand some of these results to a wider category of p-groups. In particular we calculate the cohomology of the p-groups n,k which are defined to be the kernel of the mod p reduction GLn(Z/p k+1 Z) mod ! GLn(Fp).
Unsupervised Discovery of Mid-Level Discriminative Patches

The goal of this paper is to discover a set of discriminative patches which can serve as a fully unsupervised mid-level visual representation. The desired patches need to satisfy two requirements: 1) to be representative, they need to occur frequently enough in the visual world; 2) to be discriminative, they need to be different enough from the rest of the visual world. The patches could correspond to parts, objects, "visual phrases", etc. but are not restricted to be any one of them. We pose this as an unsupervised discriminative clustering problem on a huge dataset of image patches. We use an iterative procedure which alternates between clustering and training discriminative classifiers, while applying careful cross-validation at each step to prevent overfitting. The paper experimentally demonstrates the effectiveness of discriminative patches as an unsupervised mid-level visual representation, suggesting that it could be used in place of visual words for many tasks. Furthermore, discriminative patches can also be used in a supervised regime, such as scene classification, where they demonstrate state-of-the-art performance on the MIT Indoor-67 dataset.
Where do alliances come from?: The effects of upper echelons on alliance formation

Abstract Alliances with established organizations provide young firms with resources necessary for survival. We build on recent organizational research examining the effect of upper echelons on attracting powerful intermediaries to understand how young biotechnology firms establish alliances with established organizations. Drawing upon the concept of homophily, we test hypotheses regarding the extent to which young firms and partners match along specific homophily dimensions. Our findings from an event-history analysis of 3,200 career histories of managers who took biotechnology firms public between 1979 and 1996 show that alliance formation is related to status homophily and role-based homophily between young and established organizations.
Power-associative, conjugacy closed loops

Abstract We study conjugacy closed loops (CC-loops) and power-associative CC-loops (PACC-loops). If Q is a PACC-loop with nucleus N , then Q / N is an abelian group of exponent 12; if in addition Q is finite, then | Q | is divisible by 16 or by 27. There are eight nonassociative PACC-loops of order 16, three of which are not extra loops. There are eight nonassociative PACC-loops of order 27, four of which have the automorphic inverse property. We also study some special elements in loops, such as Moufang elements, weak inverse property (WIP) elements, and extra elements. In a CC-loop, the set of WIP and the set of extra elements are normal subloops. For each c in a PACC-loop, c 3 is WIP, c 6 is extra, and c 12 ∈ N .
Wilcoxon–Mann–Whitney Test

This is a method of comparing the size of observations in two groups by ranking all the observations and comparing the average ranks of the two groups. The distribution theory is described. The test has high efficiency for the comparison of two normal distributions with the same variance, and is much better than the t test for some nonnormal distributions. Topics discussed include adjustment for tied data and the calculation of confidence limits for a difference in translation between the two distributions. Keywords: rank; ARE; tied data; two-sample t test
Redesigning lattice QCD

There has been major progress in recent years in the development of improved discretizations of the QCD action, current operators, etc for use in numerical simulations that employ very coarse lattices. These lectures review the field theoretic techniques used to design these discretizations, techniques for testing and tuning the new formalisms that result, and recent simulation results employing these formalisms.
Second-Order Optimality Conditions for Variable End Time Terminal Control Problems

A set of sufficient conditions for a weak minimum is derived for the nonsingular Bolza problem of variational calculus, expressed in control notation. The initial state and time are assumed fixed; the terminal state and time are variable, subject to a set of equality constraints. Specified terminal time is considered as a special case. The sufficient conditions derived are minimal sets for normal problems. The existence of a matrix determined by backward integration of a Riccati equation takes the place of the classical conditions involving conjugate points or focal points. This condition is easier to implement than the classical conditions in optimization problems requiring numerical solution. During the backward integration, feedback gains for deviations in the state variables and terminal constraints are easily computed for use in a neighboring optimum control law. The conditions derived are shown to be easier to apply, more concise, and more generally valid than several other recently proposed sets of optimality conditions.
Security proof of a semi-quantum key distribution protocol

Semi-quantum key distribution protocols are designed to allow two users to establish a secure secret key when one of the two users is limited to performing certain “classical” operations. There have been several such protocols developed recently, however, due to their reliance on a two-way quantum communication channel (and thus, the attacker's opportunity to interact with the qubit twice), their security analysis is difficult and little is known concerning how secure they are compared to their fully quantum counterparts. In this paper we prove the unconditional security of a particular semi-quantum protocol and derive an expression for its key rate, in the asymptotic scenario.
Shuttle imaging radar - Research sensor for earth resources observation

The operating characteristics of the Shuttle Imaging Radar (SIR) and intended experimentation to study the effects of the incidence angle, look direction, frequency, and polarization are described. SIR will be flown in 1984-1986, operate in the L- and C-bands, and have a look angle which can be varied through 15-75 deg. Polarizations of HH on the L-band and HH, VV, HV, and VH on the C-band are possible. The SIR will provide 10 and 30 m resolutions in the high and low resolution modes, respectively, with a swatch width between 35-125 km. Real-time to ground and on-board optical recording will be available, together with digital and optical processing. The antennas will be rotated in the Shuttle bay in 5 deg increments, permitting the formation of stereo pictures during several overpasses. Viewing at 1275 MHz is intended for imaging, while the 5300 MHz band can sense soil moisture
Quantum deformations of fundamental groups of oriented 3-manifolds

We compute two-term skein modules of framed oriented links in oriented 3-manifolds. They contain the self-writhe and total linking number invariants of framed oriented links in a universal way. The relations in a natural presentation of the skein module are interpreted as monodromies in the space of immersions from circles to the 3-manifold.
The last word(s) on CPOD 2013

Higher order moments of net conserved charge fluctuations, in particular net baryon number and net electric charge, are sensitive thermodynamic observables that respond strongly to critical behavior in strong interaction matter. In order to use them also as a sensible probe to detect critical behavior in heavy ion experiments we not only need to better understand the relation between chemical freeze-out in heavy ion collision and the QCD phase boundary, we also need to verify that charge fluctuations measured experimentally indeed correspond to thermal conditions as described by equilibrium QCD. This requires a model independent characterization of thermal conditions for which cumulants of conserved charge fluctuations themselves are ideally suited.
Metareasoning for planning under uncertainty

The conventional model for online planning under uncertainty assumes that an agent can stop and plan without incurring costs for the time spent planning. However, planning time is not free in most real-world settings. For example, an autonomous drone is subject to nature's forces, like gravity, even while it thinks, and must either pay a price for counteracting these forces to stay in place, or grapple with the state change caused by acquiescing to them. Policy optimization in these settings requires metareasoning-- a process that trades off the cost of planning and the potential policy improvement that can be achieved. We formalize and analyze the metareasoning problem for Markov Decision Processes (MDPs). Our work subsumes previously studied special cases of metareasoning and shows that in the general case, metareasoning is at most polynomially harder than solving MDPs with any given algorithm that disregards the cost of thinking. For reasons we discuss, optimal general metareasoning turns out to be impractical, motivating approximations. We present approximate metareasoning procedures which rely on special properties of the BRTDP planning algorithm and explore the effectiveness of our methods on a variety of problems.
Quasistationary distributions for one-dimensional diffusions with killing

We extend some results on the convergence of one-dimensional diffusions killed at the boundary, conditioned on extended survival, to the case of general killing on the interior. We show, under fairly general conditions, that a diffusion conditioned on long survival either runs off to infinity almost surely, or almost surely converges to a quasistationary distribution given by the lowest eigenfunction of the generator. In the absence of internal killing, only a sufficiently strong inward drift can keep the process close to the origin, to allow convergence in distribution. An alternative, that arises when general killing is allowed, is that the conditioned process is held near the origin by a high rate of killing near oo. We also extend, to the case of general killing, the standard result on convergence to a quasistationary distribution of a diffusion on a compact interval.
Lifschitz tail in a magnetic field: coexistence of classical and quantum behavior in the borderline case

We establish the exact low-energy asymptotics of the integrated density of states (Lifschitz tail) in a homogeneous magnetic field and Poissonian impurities with a repulsive single-site potential of Gaussian decay. It has been known that the Gaussian potential tail discriminates between the so-called “classical” and “quantum” regimes, and precise asymptotics are known in these cases. For the borderline case, the coexistence of the classical and quantum regimes was conjectured. Here we settle this last remaining open case to complete the full picture of the magnetic Lifschitz tails.
Seeing Planck Scale Physics at Accelerators

Much current theoretical analysis is based on the hypothesis that the physics beyond the Standard Model is a consequence of new principles that occur at the Planck scale. The question arises whether such principles can ever be directly tested. We show here that for a significant class of models, hypotheses at the string or Planck scale can indeed be directly tested to relatively high precision by linear colliders. Three classes of models are examined: those with universal SUSY soft breaking at the string scale; those with a horizontal symmetry at the string or Planck scale, and simple Calabi-Yau superstring models with dilaton and moduli SUSY breaking.
Perceived Information Needs and Communication Difficulties of Inpatient Physicians and Nurses

In order to understand the differing perceptions of information needs and communication patterns of healthcare professionals as they relate to medical errors, we conducted a survey and 5 focus group sessions of inpatient physicians and nurses. Although nurses and physicians stated differing information needs, both groups expressed significant problems with obtaining patient, domain and institution-specific information in a timely manner. Identification of appropriate providers and establishing contact with those people was perceived as the most pressing communication need. All focus group participants felt that communication difficulties were common and could give examples in which such difficulties led to adverse events. Our studies suggest that information needs and communication difficulties are common and can lead to medical errors or near misses. Many of these problems may be amenable to information technology solutions.
Structural Symmetry and Model Checking

A fully automatic framework is presented for identifying symmetries in structural descriptions of digital circuits and CTL formulas and using them in a model checker. The set of sub-formulas of a formula is partitioned into equivalence classes so that truth values for only one sub-formula in any class need be evaluated for model checking. Structural symmetries in net-list descriptions of digital circuits and CTL formulas are formally defined and their relationship with the corresponding Kripke structures is described. A technique for automatic identification of structural symmetries is described that requires computation of the automorphism group of a suitable labeled directed graph. A novel fast algorithm for this problem is presented. Finally, experimental results are reported for BLIF-MV net-lists derived from Verilog.
Information Surfaces in Systems Biology and Applications to Engineering Sustainable Agriculture

Systems biology of plants offers myriad opportunities and many challenges in modeling. A number of technical challenges stem from paucity of computational methods for discovery of the fundamental properties of complex dynamical systems in biology. In systems engineering, eigen-mode analysis has proved to be a powerful approach to extract system parameters. Following this philosophy, we introduce a new theory that has the benefits of eigen-mode analysis, while it allows investigation of complex dynamics prior to estimation of optimal scales and resolutions. Information Surfaces organize the many intricate relationships among “eigen-modes” of gene networks at multiple scales. Via an adaptable multi-resolution analytic approach, one could find the appropriate scale and resolution for discovery of functions of genes in plants. This article pertains the model plant Arabidopsis; however, almost all methods can be applied to investigate development and growth of crops for research on sustainable agriculture.
Robust time-series retrieval using probabilistic adaptive segmental alignment

Traditional pairwise sequence alignment is based on matching individual samples from two sequences, under time monotonicity constraints. However, in many application settings, matching subsequences (segments) instead of individual samples may bring in additional robustness to noise or local non-causal perturbations. This paper presents an approach to segmental sequence alignment that jointly segments and aligns two sequences, generalizing the traditional per-sample alignment. To accomplish this task, we introduce a distance metric between segments based on average pairwise distances and then present a modified pair-HMM (PHMM) that incorporates the proposed distance metric to solve the joint segmentation and alignment task. We also propose a relaxation to our model that improves the computational efficiency of the generic segmental PHMM. Our results demonstrate that this new measure of sequence similarity can lead to improved classification performance, while being resilient to noise, on a variety of sequence retrieval problems, from EEG to motion sequence classification.
A Contract-Based Approach of Resource-Constrained Software Deployment

Software deployment can turn into a baffling problem when the components being deployed exhibit non-functional requirements. If the platform on which such components are deployed cannot satisfy their non-functional requirements, then they may in turn fail to perform satisfactorily. In this paper we propose a contract-based approach of resource-constrained software deployment. We thus focus on a specific category of non-functional requirements: those that pertain to the resources software components need to use at runtime. Ultimately, our objective is to provide software components with means to specify their requirements regarding hardware and/or software resources, and to design methods and models for utilising this kind of information at any stage of a component's life-cycle. The paper reports the design of Jamus, an experimental platform we develop in order to support the deployment of mobile software components, while providing these components with guaranteed access to the resources they need. JAMUS implements a contract-based model so as to recognise and to allow for the requirements of components regarding resource access and consumption.
What are Barrier Islands Worth? Estimates of Willingness to Pay for Restoration

A dichotomous-choice contingent-valuation survey was conducted in the State of Mississippi (USA) to estimate willingness to pay (WTP) for three restoration options being considered for the state's barrier islands. Random-effects probit models were estimated, and parametric and non-parametric WTP estimates and confidence intervals were calculated. Turnbull lower-bound mean WTP was $22 per respondent to maintain the existing footprint over a 30-year period, $152 to restore 2,338 acres (pre-1969 footprint), and $277 to restore 5,969 acres (pre-1900 footprint). Econometric results indicate that for the Pre-Camille and Pre-1900 options, coastal residents and those citing storm protection, recreation impact, and environmental impact as primary decision factors, were more likely to support restoration, with marginal effects of these greater for the Pre-Camille option. For the Status-Quo option, 75% of respondents voted in favor of restoration, and the offered bid was not significant; only the hurricane-protectio...
Optimal lower bounds for quantum automata and random access codes

Consider the finite regular language L/sub n/={w0|w/spl isin/{0,1}*,|w|/spl les/n}. A. Ambainis et al. (1999) showed that while this language is accepted by a deterministic finite automaton of size O(n), any one-way quantum finite automaton (QFA) for it has size 2/sup /spl Omega/(n/logn)/. This was based on the fact that the evolution of a QFA is required to be reversible. When arbitrary intermediate measurements are allowed, this intuition breaks down. Nonetheless, we show a 2/sup /spl Omega/(n)/ lower bound for such QFA for L/sub n/, thus also improving the previous bound. The improved bound is obtained from simple entropy arguments based on A.S. Holevo's (1973) theorem. This method also allows us to obtain an asymptotically optimal (1-H(p))n bound for the dense quantum codes (random access codes) introduced by A. Ambainis et al. We then turn to Holevo's theorem, and show that in typical situations, it may be replaced by a tighter and more transparent in-probability bound.
A Delayed Choice Quantum Eraser Explained by the Transactional Interpretation of Quantum Mechanics

This paper explains the delayed choice quantum eraser of Kim et al. (A delayed choice quantum eraser, 1999) in terms of the transactional interpretation (TI) of quantum mechanics by Cramer (Rev Mod Phys 58:647, 1986, The quantum handshake, entanglement, nonlocality and transactions, 1986). It is kept deliberately mathematically simple to help explain the transactional technique. The emphasis is on a clear understanding of how the instantaneous “collapse” of the wave function due to a measurement at a specific time and place may be reinterpreted as a relativistically well-defined collapse over the entire path of the photon and over the entire transit time from slit to detector. This is made possible by the use of a retarded offer wave, which is thought to travel from the slits (or rather the small region within the parametric crystal where down-conversion takes place) to the detector and an advanced counter wave traveling backward in time from the detector to the slits. The point here is to make clear how simple the transactional picture is and how much more intuitive the collapse of the wave function becomes if viewed in this way. Also, any confusion about possible retro-causal signaling is put to rest. A delayed choice quantum eraser does not require any sort of backward in time communication. This paper makes the point that it is preferable to use the TI over the usual Copenhagen interpretation for a more intuitive understanding of the quantum eraser delayed choice experiment. Both methods give exactly the same end results and can be used interchangeably.
Algorithms for a Simple Point Placement Problem

We consider algorithms for a simple one-dimensional point placement problem: given N points on a line, and noisy measurements of the distances between many pairs of them, estimate the relative positions of the points. Problems of this flavor arise in a variety of contexts. The particular motivating example that inspired this work comes from molecular biology; the points are markers on a chromosome and the goal is to map their positions. The problem is NP-hard under reasonable assumptions. We present two algorithms for computing least squares estimates of the ordering and positions of the markers: a branch and bound algorithm and a highly effective heuristic search algorithm. The branch and bound algorithm is able to solve to optimality problems of 18 markers in about an hour, visiting about 106 nodes out of a search space of 1016 nodes. The local search algorithm usually was able to find the global minimum of problems of similar size in about one second, and should comfortably handle much larger problem instances.
Causal inference of regulator-target pairs by gene mapping of expression phenotypes

Correlations between polymorphic markers and observed phenotypes provide the basis for mapping traits in quantitative genetics. When the phenotype is gene expression, then loci involved in regulatory control can theoretically be implicated. Recent efforts to construct gene regulatory networks from genotype and gene expression data have shown that biologically relevant networks can be achieved from an integrative approach. In this paper, we consider the problem of identifying individual pairs of genes in a direct or indirect, causal, trans-acting relationship. Inspired by epistatic models of multi-locus quantitative trait (QTL) mapping, we propose a unified model of expression and genotype to identify quantitative trait genes (QTG) by extending the conventional linear model to include both genotype and expression of regulator genes and their interactions. The model provides mapping of specific genes in contrast to standard linkage approaches that implicate large QTL intervals typically containing tens of genes. In simulations, we found that the method can often detect weak trans-acting regulators amid the background noise of thousands of traits and is robust to transcription models containing multiple regulator genes. We reanalyze several pleiotropic loci derived from a large set of yeast matings and identify a likely alternative regulator not previously published. However, we also found that many regulators can not be so easily mapped due to the presence of cis-acting QTLs on the regulators, which induce close linkage among small neighborhoods of genes. QTG mapped regulator-target pairs linked to ARN1 were combined to form a regulatory module, which we observed to be highly enriched in iron homeostasis related genes and contained several causally directed links that had not been identified in other automatic reconstructions of that regulatory module. Finally, we also confirm the surprising, previously published results that regulators controlling gene expression are not enriched for transcription factors, but we do show that our more precise mapping model reveals functional enrichment for several other biological processes related to the regulation of the cell. By incorporating interacting expression and genotype, our QTG mapping method can identify specific regulator genes in contrast to standard QTL interval mapping. We have shown that the method can recover biologically significant regulator-target pairs and the approach leads to a general framework for inducing a regulatory module network topology of directed and undirected edges that can be used to identify leads in pathway analysis.
“Missing girls” in the south Caucasus countries : trends, possible causes, and policy options

Sex ratios at birth rose sharply in the South Caucasus countries after 1991, but recent data indicate that this trend is turning. What caused this rise, and what can be done to accelerate its normalization? Traditional kinship systems in the region are similar to those of other settings with sex-selection: structured for collaboration among male kin and dependence only on sons, not daughters. Yet it is anomalous to find sex-selection in a region that under the Soviet Union has for long been substantially urbanized and gender-equitable in public life — factors associated with declines in sex-selection elsewhere. Sex-selection manifested itself only after the sudden economic and governance meltdown following the dissolution of the Soviet Union in 1991. Jobs, basic services, and social protection mechanisms unraveled. People scrambled for coping mechanisms, and sons offer the traditional form of support under uncertainty. Basic services, pensions, and safety nets have been rebuilt, but the process involved years of policy changes. Strengthening these institutions, and maintaining credible continuity of expectations in them, is critical to accelerating normalization of sex ratios.
A Constraint-Based Approach to Assigning System Components to Tasks

In multi-component systems, individual components must be assigned to the tasks that they are to perform. In many applications, there are several possible task decompositions that could be used to achieve the task, and there are limited resources available throughout the system. We present a technique for making task assignments under these conditions. Constraint satisfaction is used to assign components to particular tasks. Heuristics suggest a task decomposition for which an assignment can be found efficiently. We have applied our technique to the problem of task assignment in systems of underwater robots and instrument platforms working together to collect data in the ocean.
Chapter 3 – Thyroid Gland

Publisher Summary This chapter describes the structure of thyroid gland and the biochemistry of thyroid hormones; such as their biosynthesis, physiological effects, regulation of secretion, and mechanisms of action. The functional unit of the thyroid gland is the follicle, which is composed of epithelial cells arranged as hollow vesicles of various shapes. Chemically, thyroid hormones are α-amino acid derivatives of tyrosine and include thyroxine and triiodothyronine. Thyroxine contains four atoms of iodine and is abbreviated as T4; triiodothyronine, which has three atoms of iodine, is abbreviated as T3. Thyroxine, the major secretory product, is not the biologically active form of the hormone; however, it must be transformed to T3 at extrathyroidal sites. Biosynthesis of thyroid hormones involves several discrete processes, all of which depend upon the products of three genes that are expressed predominantly in thyroid follicle cells: the sodium iodide symporter (NIS), thyroglobulin, and thyroid peroxidase. The physiological effects of thyroid hormones include growth and maturation of skeletal system, central and autonomic nervous systems, and cardiovascular system. The thyroid gland exerts profound effects on oxidative, carbohydrate, and lipid metabolism in humans. The principal regulator of thyroid function is the thyroid-stimulating hormone (TSH), which is secreted by thyrotropes in the pituitary gland; however, maintaining constant levels of thyroid hormones in blood depends upon negative feedback effects of T4 and T3, which inhibit synthesis and secretion of TSH. Evidence indicates that T3 and T4 produce the majority of their actions through nuclear receptors, but detailed understanding require further research.
What’s news in exchange rate dynamics: A DSGE approach

Abstract This paper examines the medium and long-term impacts of economic news on exchange rate movements. We extend a standard new open economy macroeconomics model by allowing anticipated (news) shocks in purchasing power parity and real interest rates, and perform a structural Bayesian estimation. Using 20 years of quarterly data from the US and the euro area, we find that anticipated shocks account for more than 40 percent of exchange rate fluctuations.
Accelerating Energy Innovation: Insights from Multiple Sectors

Accelerating energy innovation could be an important part of an effective response to the threat of climate change. Written by a stellar group of experts in the field, this book complements existing research on the subject with an exploration of the role that public and private policy have played in enabling - and sustaining - swift innovation in a variety of industries, from agriculture and the life sciences to information technology. Chapters highlight the factors that have determined the impact of past policies and suggest that effectively managed federal funding, strategies to increase customer demand, and the enabling of aggressive competition from new firms are important ingredients for policies that affect innovative activity.
ChAInGeS: The Chandra Arp Interacting Galaxies Survey

We have conducted a statistical analysis of the ultra-luminous X-ray point sources (ULXs; L{sub X} {>=} 10{sup 39} erg s{sup -1}) in a sample of galaxies selected from the Arp Atlas of Peculiar Galaxies. We find a possible enhancement of a factor of {approx}2-4 in the number of ULXs per blue luminosity for the strongly interacting subset. Such an enhancement would be expected if ULX production is related to star formation, as interacting galaxies tend to have enhanced star formation rates on average. For most of the Arp galaxies in our sample, the total number of ULXs compared to the far-infrared luminosity is consistent with values found earlier for spiral galaxies. This suggests that for these galaxies, ULXs trace recent star formation. However, for the most infrared-luminous galaxies, we find a deficiency of ULXs compared to the infrared luminosity. For these very infrared-luminous galaxies, active galactic nuclei may contribute to powering the far-infrared; alternatively, ULXs may be highly obscured in the X-ray in these galaxies and therefore not detected by these Chandra observations. We determined local UV/optical colors within the galaxies in the vicinity of the candidate ULXs using Galaxy Evolution Explorer UV and Sloan Digitized Sky Survey optical images.more » In most cases, the distributions of colors are similar to the global colors of interacting galaxies. However, the u - g and r - i colors at the ULX locations tend to be bluer on average than these global colors, suggesting that ULXs are preferentially found in regions with young stellar populations. In the Arp sample there is a possible enhancement of a factor of {approx}2-5 in the fraction of galactic nuclei that are X-ray-bright compared to more normal spirals.« less
Development of a New Family of Chiral Auxiliaries

A new family of chiral auxiliaries designed on a conformationally restricted version of (-)-8-phenylmenthol has been developed. Both enantiomers are available from an inexpensive synthesis conducted on multigram scale. A first application has showed comparable diastereoselectivity between the novel auxiliary and (-)-8-phenylmenthol.
Barriers to mental health service use and preferences for addressing emotional concerns among lung cancer patients

Objective This study examined barriers to mental health service use and preferences for addressing emotional concerns among lung cancer patients (N = 165) at two medical centers in the Midwestern United States. Methods Lung cancer patients completed an assessment of anxiety and depressive symptoms, mental health service use, barriers to using these services, and preferences for addressing emotional concerns. Results Only 45% of distressed patients received mental health care since their lung cancer diagnosis. The most prevalent patient-reported barriers to mental health service use among non-users of these services (n = 110) included the desire to independently manage emotional concerns (58%) and inadequate knowledge of services (19%). In addition, 57% of distressed patients who did not access mental health services did not perceive the need for help. Seventy-five percent of respondents (123/164) preferred to talk to a primary care physician if they were to have an emotional concern. Preferences for counseling, psychiatric medication, peer support, spiritual care, or independently managing emotional concerns also were endorsed by many patients (range = 40–50%). Older age was associated with a lower likelihood of preferring to see a counselor. Conclusions Findings suggest that many distressed lung cancer patients underuse mental health services and do not perceive the need for such services. Efforts to increase appropriate use of services should address patients' desire for autonomy and lack of awareness of services. Copyright © 2014 John Wiley & Sons, Ltd.
The Prompt Energy Release of Gamma-Ray Bursts using a Cosmological k-Correction

The fluences of gamma-ray bursts (GRBs) are measured with a variety of instruments in different detector energy ranges. A detailed comparison of the implied energy releases of the GRB sample requires then an accurate accounting of this diversity in fluence measurements that properly corrects for the redshifting of GRB spectra. Here we develop a methodology to "k-correct" the implied prompt energy release of a GRB to a fixed comoving bandpass. This allows us to homogenize the prompt energy release of 17 cosmological GRBs (using published redshifts, fluences, and spectra) to two common comoving bandpasses: 20–2000 keV and 0.1 keV–10 MeV ("bolometric"). While the overall distribution of GRB energy releases does not change significantly by using a k-correction, we show that uncorrected energy estimates systematically undercount the bolometric energy by ~5% to 600%, depending on the particular GRB. We find that the median bolometric isotropic equivalent prompt energy release is 2.19 × 1053 ergs, with an rms scatter of 0.80 dex. The typical estimated uncertainty on a given k-corrected energy measurement is ~20%.
Enhanced Li capacity in functionalized graphene: A first principle study with van der Waals correction

We have investigated the adsorption of Li on graphene oxide using density functional theory. We show a novel and simple approach to achieve a positive lithiation potential on epoxy and hydroxyl functionalized graphene, compared to the negative lithiation potential that has been found on prestine graphene. We included the van der Waals correction into the calculation so as to get a better picture of weak interactions. A positive lithiation potential suggests a favorable adsorption of Li on graphene oxide sheets that can lead to an increase in the specific capacity, which in turn can be used as an anode material in Li-batteries. We find a high specific capacity of ∼860 mAhg−1 by functionalizing the graphene sheet. This capacity is higher than the previously reported capacities that were achieved on graphene with high concentration of Stone-Wales (75%) and divacancy (16%) defects. Creating such high density of defects can make the entire system energetically unstable, whereas graphene oxide is a naturally occurring substance.