cssi/SciSciGPT-SciSciNet huggingface dataset:
A moment-equation-copula-closure method for nonlinear vibrational systems subjected to correlated noise

Abstract We develop a moment-equation-copula-closure method for the inexpensive approximation of the steady state statistical structure of strongly nonlinear systems which are subjected to correlated excitations. Our approach relies on the derivation of moment equations that describe the dynamics governing the two-time statistics. These are combined with a non-Gaussian pdf representation for the joint response-excitation statistics, based on copula functions that has (i) single time statistical structure consistent with the analytical solutions of the Fokker–Planck equation, and (ii) two-time statistical structure with Gaussian characteristics. Through the adopted pdf representation, we derive a closure scheme which we formulate in terms of a consistency condition involving the second order statistics of the response, the closure constraint. A similar condition, the dynamics constraint, is also derived directly through the moment equations. These two constraints are formulated as a low-dimensional minimization problem with respect to the unknown parameters of the representation, the minimization of which imposes an interplay between the dynamics and the adopted closure. The new method allows for the semi-analytical representation of the two-time, non-Gaussian structure of the solution as well as the joint statistical structure of the response-excitation over different time instants. We demonstrate its effectiveness through the application on bistable nonlinear single-degree-of-freedom energy harvesters with mechanical and electromagnetic damping, and we show that the results compare favorably with direct Monte-Carlo simulations.
Almost isometric constants for partial unconditionality

We discuss optimal constants of certain projections on subsequences of weakly null sequences. Positive results yield constants arbitrarily close to $1$ for Schreier type projections, and arbitrarily close to $1$ for Elton type projections under the assumption that the weakly null sequence admits no subsequence generating a $c_0$ spreading model. As an application, we prove that a weakly null sequence admitting a spreading model not equivalent to the $c_0$ basis has a quasi-greedy subsequence with quasi-greedy constant arbitrarily close to $1$.
Enhancing the performance of the T-peel test for thin and flexible adhered laminates

Symmetrically bonded thin and flexible T-peel specimens, when tested on vertical travel machines, can be subject to significant gravitational loading, with the associated asymmetry and mixed-mode failure during peeling. This can cause erroneously high experimental peel forces to be recorded which leads to uncertainty in estimating interfacial fracture toughness and failure mode. To overcome these issues, a mechanical test fixture has been designed, for use with vertical test machines, that supports the unpeeled portion of the test specimen and suppresses parasitic loads due to gravity from affecting the peel test. The mechanism, driven by the test machine cross-head, moves at one-half of the velocity of the cross-head such that the unpeeled portion always lies in the plane of the instantaneous center of motion. Several specimens such as bonded polymeric films, laminates, and commercial tapes were tested with and without the fixture, and the importance of the proposed T-peel procedure has been demonstrated.
Dry deposition to snow in an urban area

Ambient particle and gas concentrations, wet deposition and dry deposition were measured in Warren, MI between December 18, 1983 and April 6, 1984. Dry deposition was measured to various surfaces in a cutoff bucket, including a snow surface, a snow/water surface during melting and a deionized water surface. Dry deposition velocities were calculated for various species from the ratio of the dry flux to the ambient concentrations. The dry deposition velocities measured to a snow surface were 0.082 cm s−1 SO2 2.0 for HNO3, 0.083 for NH4 +, 2.0 for Ca++ and 4.3 for Cl−. The values were not significantly different for a snow/water surface during melting compared to a snow surface. However, higher values of 0.69 cm s−1 for SO2, 6.2 for HNO3, 0.33 for NH4 +, and 4.2 for Ca++ were found to a deionized water surface in the spring. These higher values could be due to the higher air temperature, the pH of the liquid or to increased atmospheric mixing during this period.
Symmetry-guided large-scale shell-model theory

Abstract In this review, we present a symmetry-guided strategy that utilizes exact as well as partial symmetries for enabling a deeper understanding of and advancing ab initio studies for determining the microscopic structure of atomic nuclei. These symmetries expose physically relevant degrees of freedom that, for large-scale calculations with QCD-inspired interactions, allow the model space size to be reduced through a very structured selection of the basis states to physically relevant subspaces. This can guide explorations of simple patterns in nuclei and how they emerge from first principles, as well as extensions of the theory beyond current limitations toward heavier nuclei and larger model spaces. This is illustrated for the ab initio symmetry-adapted no-core shell model (SA-NCSM) and two significant underlying symmetries, the symplectic Sp ( 3 , R ) group and its deformation-related SU ( 3 ) subgroup. We review the broad scope of nuclei, where these symmetries have been found to play a key role—from the light p -shell systems, such as 6 Li, 8 B, 8 Be, 12 C, and 16 O, and s d -shell nuclei exemplified by 20 Ne, based on first-principle explorations; through the Hoyle state in 12 C and enhanced collectivity in intermediate-mass nuclei, within a no-core shell-model perspective; up to strongly deformed species of the rare-earth and actinide regions, as investigated in earlier studies. A complementary picture, driven by symmetries dual to Sp ( 3 , R ) , is also discussed. We briefly review symmetry-guided techniques that prove useful in various nuclear-theory models, such as Elliott model, ab initio SA-NCSM, symplectic model, pseudo- SU ( 3 ) and pseudo-symplectic models, ab initio hyperspherical harmonics method, ab initio lattice effective field theory, exact pairing–plus–shell model approaches, and cluster models, including the resonating-group method. Important implications of these approaches that have deepened our understanding of emergent phenomena in nuclei, such as enhanced collectivity, giant resonances, pairing, halo, and clustering, are discussed, with a focus on emergent patterns in the framework of the ab initio SA-NCSM with no a priori assumptions.
Divergent MLS1 promoters lie on a fitness plateau for gene expression

Qualitative patterns of gene activation and repression are often conserved despite an abundance of quantitative variation in expression levels within and between species. A major challenge to interpreting patterns of expression divergence is knowing which changes in gene expression affect fitness. To characterize the fitness effects of gene expression divergence, we placed orthologous promoters from eight yeast species upstream of malate synthase (MLS1) in Saccharomyces cerevisiae As expected, we found these promoters varied in their expression level under activated and repressed conditions as well as in their dynamic response following loss of glucose repression. Despite these differences, only a single promoter driving near basal levels of expression caused a detectable loss of fitness. We conclude that the MLS1 promoter lies on a fitness plateau whereby even large changes in gene expression can be tolerated without a substantial loss of fitness.
Single Guide RNA Library Design and Construction

This protocol describes how to generate a single guide RNA (sgRNA) library for use in genetic screens. There are many online tools available for predicting sgRNA sequences with high target specificity and/or cleavage activity. Here, we refer the user to genome-wide sgRNA sequence predictions that we have developed for both the human and mouse and that are available from the Broad Institute website. Once a set of target genes and corresponding sgRNA sequences has been identified, customized oligonucleotide pools can be rapidly synthesized by a number of commercial vendors. Thereafter, as described here, the oligonucleotides can be efficiently cloned into an appropriate lentiviral expression vector backbone. The resulting plasmid pool can then be packaged into lentiviral particles and used to generate knockouts in any cell line of choice.
Structure, inhibition and regulation of two-pore channel TPC1 from Arabidopsis thaliana

The X-ray crystal structure of a two-pore channel from Arabidopsis thaliana is reported, revealing the mechanisms of ion permeation, inhibition channel activation, and location of regulatory sites and voltage-sensing domains. The X-ray crystal structure of the two-pore channel AtTPC1 from Arabidopsis thaliana reveals the structure and mechanism of voltage gating of a type of cation-selective ion channel ubiquitously expressed in the organelles of animal and plant cells. AtTPC1 is activated by both voltage and cytosolic Ca2+, and voltage activation can be inhibited by luminal Ca2+. Youxing Jiang and colleagues determined the crystal structure of AtTPC1 to 3.3 A resolution and find that, as predicted, two AtTPC1 subunits make up the functional channel. Alexander Kintzer and Robert Stroud report the AtTPC1 crystal structure at 2.87 A resolution, revealing the mechanisms of ion permeation, channel activation, and location of regulatory sites and voltage-sensing domains. Two-pore channels (TPCs) comprise a subfamily (TPC1–3) of eukaryotic voltage- and ligand-gated cation channels1,2 with two non-equivalent tandem pore-forming subunits that dimerize to form quasi-tetramers. Found in vacuolar3 or endolysosomal4 membranes, they regulate the conductance of sodium5 and calcium3,6 ions, intravesicular pH5, trafficking7 and excitability8,9. TPCs are activated by a decrease in transmembrane potential1,3,9,10 and an increase in cytosolic calcium concentrations1,10, are inhibited by low luminal pH and calcium11, and are regulated by phosphorylation12,13. Here we report the crystal structure of TPC1 from Arabidopsis thaliana at 2.87 A resolution as a basis for understanding ion permeation3,4,10, channel activation1,5,10, the location of voltage-sensing domains1,9,10 and regulatory ion-binding sites11,14. We determined sites of phosphorylation3,4 in the amino-terminal and carboxy-terminal domains that are positioned to allosterically modulate cytoplasmic Ca2+ activation. One of the two voltage-sensing domains (VSD2) encodes voltage sensitivity and inhibition by luminal Ca2+ and adopts a conformation distinct from the activated state observed in structures of other voltage-gated ion channels15,16. The structure shows that potent pharmacophore trans-Ned-19 (ref. 17) acts allosterically by clamping the pore domains to VSD2. In animals, Ned-19 prevents infection by Ebola virus and other filoviruses, presumably by altering their fusion with the endolysosome and delivery of their contents into the cytoplasm7.
Oblivious channels

Let C = {X1,...,XN} sub {0, 1}n be an [n, N] binary error correcting code (not necessarily linear). Let e isin {0, 1}n be an error vector. A codeword X isin C is said to be disturbed by the error e if the closest codeword to X oplus e is no longer X. Let Ae be the subset of codewords in C that are disturbed by e. In this work we study the size of Ae in random codes C (i.e. codes in which each codeword Xi is chosen uniformly and independently at random from {0, 1}n). Using recent results of Vu [random structures and algorithms 20(3)] on the concentration of non-Lipschitz functions, we show that |Ae| is strongly concentrated for a wide range of values of N and parepar. We apply this result in the study of communication channels we refer to as oblivious. Roughly speaking, a channel W(y|x) is said to be oblivious if the error distribution imposed by the channel is independent of the transmitted codeword x. For example, the well studied binary symmetric channel is an oblivious channel. In this work, we define oblivious and partially oblivious channels and present lower bounds on their capacity. The oblivious channels we define have connections to arbitrarily varying channels with state constraints
Simulation and Measurement of Medium-Frequency Signals Coupling From a Line to a Loop Antenna

The underground-mining environment can affect radio-signal propagation in various ways. Understanding these effects is especially critical in evaluating communications systems used during normal mining operations and during mine emergencies. One of these types of communications systems relies on medium-frequency (MF) radio frequencies. This paper presents the simulation and measurement results of recent National Institute for Occupational Safety and Health (NIOSH) research aimed at investigating MF coupling between a transmission line (TL) and a loop antenna in an underground coal mine. Two different types of measurements were completed: 1) line-current distribution and 2) line-to-antenna coupling. Measurements were taken underground in an experimental coal mine and on a specially designed surface test area. The results of these tests are characterized by current along a TL and voltage induced in the loop from a line. This paper concludes with a discussion of issues for MF TLs. These include electromagnetic fields at the ends of the TL, connection of the ends of the TL, the effect of other conductors underground, and the proximity of coal or earth. These results could help operators by providing examples of these challenges that may be experienced underground and a method by which to measure voltage induced by a line.
Wake of a heavy quark in non-Abelian plasmas: Comparing kinetic theory and the anti-de Sitter space/conformal field theory correspondence

We compute the non-equilibrium stress tensor induced by a heavy quark moving through weakly coupled QCD plasma at the speed of light and compare the result to N = 4 Super Yang Mills theory at strong coupling. The QCD Boltzmann equation is reformulated as a Fokker-Planck equation in a leading log approximation which is used to compute the induced stress. The transition from nonequilibrium at short distances to equilibrium at large distances is analyzed with first and second order hydrodynamics. Even after accounting for the obvious differences in shear lengths, the strongly coupled theory is significantly better described by hydrodynamics at sub-asymptotic distances. We argue that this difference between the kinetic and AdS/CFT theories is related to the second order hydrodynamic coefficient $\tau_\pi$. $\tau_\pi$ is numerically large in units of the shear length for theories based on the Boltzmann equation.
Efficient geodesics and an effective algorithm for distance in the complex of curves

We give an algorithm for determining the distance between two vertices of the complex of curves. While there already exist such algorithms, for example by Leasure, Shackleton, and Webb, our approach is new, simple, and more effective for all distances accessible by computer. Our method gives a new preferred finite set of geodesics between any two vertices of the complex, called efficient geodesics, which are different from the tight geodesics introduced by Masur and Minsky.
A 2nd Generation Parallel Advancing Front Grid Generator

A scalable, parallel advancing grid generation technique has been developed for complex geometries and meshes with large size variations. The key innovation compared to previous techniques is the use of a domain-defining grid that has the same fine surface triangulation as the final mesh desired, but a much coarser interior mesh. In this way, the domain to be gridded is uniquely defined, overcoming a shortcoming of previous approaches. This domain-defining grid is then partitioned according to the estimated number of elements to be generated, allowing for a balanced distribution of work among the processors. The domain defining grid is also used to redistribute the elements and points after grid generation, and during the subsequent mesh improvement.
Engineering Management: Past, Present, and Future

Abstract:This article contributes a description of the engineering management field. The article's intent is to continue and add to the body of knowledge about the evolution of the engineering management discipline. Seven strategic issues and associated questions about the evolution of engineering management are identified by understanding the past, present, and future of the profession. The history and evolution is described. The current state is described in terms of the contributing disciplines, professional societies, journals, and conferences. The future is described by emerging trends, challenges, knowledge roles, and stakeholder needs of the profession. From this article, an engineering manager can better understand how different disciplines and professional societies could help improve understanding of their chosen profession.
Stress-Strain Behavior of Rubber-Reinforced Glassy Polymers

The main objective of this work has been to develop some rational hypothesis for the toughness of rubber-modified glassy polymers as defined by the energy to rupture in a tensile measurement. It is shown that the rigid phase yields and that the toughness is a result of the large energy absorption involved in the cold drawing of the matrix. The rubber phase acts principally to induce a yielding in the matrix. A triaxial stress field in the environment of the dispersed particles results in local increases in free volume which aid in the initiation of cold drawing and provides the rubber with sufficient breaking stress to prevent premature crack propagation.
Thermal Degradation of Polyacrylonitrile, Polybutadiene, and Copolymers of Butadiene with Acrylonitrile and Styrene

Abstract Polybutadiene and a copolymer consisting of 76.5 per cent butadiene and 23.5 per cent of styrene were investigated as to the rate of their thermal degradation. The rates for polybutadiene indicated an activation energy of 62 kilocalories per mole. The copolymer had very high initial rates of degradation followed by a rapid drop, so that it was not possible to obtain a reliable activation energy. Polyacrylonitrile and a copolymer consisting of 31 per cent of acrylonitrile and 69 per cent of butadiene were investigated with regard to the nature and distribution of volatile products, as well as to the rates of their thermal degradation. The rates were very high initially, but dropped rapidly so that it was not possible to determine accurately the activation energy. The acrylo-nitrile-butadiene copolymer showed a decomposition pattern similar to that of polybutadiene. Here, too, the activation energy could not be deduced accurately from the rate curves. Comparative thermal stability in terms of tempe...
Secretin Half-Life in Cirrhotics with High Secretory Volumes to a Secretin Test:

SummaryThe hypothesis of prolonged secretin half-life was examined in four cirrhotic patients who had pancreatic and biliary hypersecretory responses to exogenous secretin. The mean serum half-life of secretin from these patients was 2.74 ± 0.31 (SEM) min and did not differ significantly from a group of five healthy volunteers whose secretin half-life was 2.72 ± 0.41 (SEM) min (P > 0.1). In addition, the secretin half-lives correlated inversely with body weight in the cirrhotic patients. These data are consistent with the hypothesis that mechanisms other than altered secretin disappearance half-life are responsible for the hypersecretion seen in response to a secretin test in cirrhotic patients.This study was supported by NIH Research Grant AM 19425.
Synthesis of Aryl Sulfonamides via Palladium-Catalyzed Chlorosulfonylation of Arylboronic Acids

A palladium-catalyzed method for the preparation of sulfonamides is described. The process exhibits significant functional group tolerance and allows for the preparation of a number of arylsulfonyl chlorides and sulfonamides under mild conditions.
A Nontopological Proof of the Uniform Boundedness Theorem

(1980). A Nontopological Proof of the Uniform Boundedness Theorem. The American Mathematical Monthly: Vol. 87, No. 3, pp. 217-217.
An approach to structure adaptation in pattern recognition

Viewing pattern recognition as a problem in statistical classification wherein an n-dimensional hypercube is partitioned into category regions with decision boundaries, this paper focuses on a class of nonlinear boundary forms and describes a variable-structure system which is capable of evolving these boundaries adaptively. Most of the present adaptive recognition systems have a priori fixed structure, usually corresponding to a linear decision procedure, and adaptation is performed by parameter optimization. It is apparent that in practice the simple linear system frequently will be an inadequate approximation to the desired boundaries. The central problem in a more general recognition procedure is the selection and analysis of suitable nonlinear relations among measurements. In the system proposed in this paper, the structure adaptation develops as follows: the recognition network initially assumes a linear structure, a set of relations among the input measurements is generated and selected on the basis of a set of design data, and to accomodate these relations, the structure changes to nonlinear. By repetitively generating and selecting additional relations among the measurements, the structure gradually adjusts itself within the class of allowable structures toward an optimal configuration. By means of simulation on a digital computer, the procedure for structure adaptation was successfully applied to a number of practical problems, handwritten numerals, spoken vowels, and electroencephalograms.
Introduction: exercise capacities and adaptations of people with chronic disabilities--current research, future directions, and widespread applicability.

This symposium addresses the unique physiological problems, current research, future needs, and widespread applicability for research involving people experiencing five major chronic disabilities within the United States: quadriplegia, paraplegia, mental retardation, multiple sclerosis, and poliomyelitis. Each author represents ACSM members who, by their distinguished research efforts, exemplify scientists who have demonstrated their dedication to the specific needs of these populations. The papers will give a brief description of the pathophysiology of the disability and the resultant effects upon the group's acute response to exercise and their physiological adaptations to exercise programs. Each paper will include reports on the state of current research and what benefits to that group could be expected if a major research breakthrough occurred. Additionally, the papers will indicate the major research questions currently confronting each population and a brief statement about the strategy needed to resolve these questions. If applicable, the authors will address how such a model (of the specific disability/disease) could be used to better understand the able-bodied response to exercise. The purpose of this symposium, therefore, was not only to better understand the effects of exercise on persons having chronic disabilities, but from a physiological point of view, to use what we know about the response of people with chronic disabilities to better understand the able-bodied response.
Climate Change and International Economic Law

This Article examines an unexplored issue arising at the intersection of international economic law and international environmental law: How might international economic law adapt to allow states in the Global South, which are disproportionately impacted by the sudden and unforeseen impacts of global climate change, to exit or modify economic relationships that render such states more vulnerable to these negative impacts? This Article begins with an explication of the unique features of international economic law and international environmental law, and argues that the architecture of modern international economic law, which requires a certain degree of environmental stability in order to incentivize private investment, could limit a capital importing state‘s ability to respond to unforeseen environmental harm resulting from climate change. The limited solutions currently available to a capital importing state facing such circumstances, including breach, denunciation or withdrawal, could pose political, economic, and reputational costs that leave the developing state in the undesirable position of being untethered to the system of international economic law. This Article argues that climate change provides a unique opportunity to animate the moribund doctrine of fundamental change of circumstances, rebus sic stantibus, to assist states in managing the impacts of climate change within the realm of international economic law. The doctrine, rooted in equity, may provide a basis for exiting an agreement or, perhaps more desirably, renegotiating the agreement. The party invoking the doctrine must illustrate that the changes are unforeseen, the circumstances constitute an essential basis of consent to be bound by the underlying agreement, and the changed circumstances radically transform the party‘s ability to perform its obligations. Although the International Court of Justice has narrowly interpreted these doctrinal elements in the past, the climate change moment creates the imperative to broaden the scope of the doctrine and bring more flexibility to the current system of international economic law. The framework offered in this Article provides a roadmap for doing so.
The economics of The Hunger Games

Using media in the classroom is an increasingly common way to teach economics. As far back as the 1830s, Martineau created stories with an economic message. Since then, many others have explored the economics found in other works of literature. Our objective here is to analyse the economic messages of one of the most popular young adult book series of the past ten years, The Hunger Games. In this paper, we examine issues of economic organisation, comparative advantage, the role of institutions, and income inequality among others, all of which help to promote the storyline of the novel. Students have responded favourably to the use of familiar characters in explaining these ideas, and we believe that utilising literature has been and will continue to be a helpful tool for economics instructors.
Dynamic Pricing with Demand Covariates

We consider a firm that sells a product over T periods without knowing the demand function. The firm sequentially sets prices to earn revenue and to learn the underlying demand function simultaneously. In practice, this problem is commonly solved via greedy iterative least squares (GILS). At each time period, GILS estimates the demand as a linear function of the price by applying least squares to the set of prior prices and realized demands. Then a price that maximizes the revenue is used for the next period. The performance is measured by the regret, which is the expected revenue compared to an oracle that knows the true demand function. Recently, den Boer and Zwart (2014) and Keskin and Zeevi (2014) demonstrated that GILS is sub-optimal and introduced optimal algorithms which integrate forced price-dispersion with GILS. Here, we consider this dynamic pricing problem in a data-rich environment. We assume that the firm has access to demand covariates which may be predictive of the demand and prove that GILS achieves an asymptotically optimal regret of order log(T). We also show that the asymptotic optimality of GILS holds even when the covariates are uninformative. We validate our results via simulations on synthetic and real data.
Dyke Award. Harmonic Modulation of Proton MR Precessional Phase by Pulsatile Motion: Origin of Spinal CSF Flow Phenomena

The effects of pulsatile motion on MR imaging of spinal CSF were quantitatively evaluated with a spine phantom that simulated spinal CSF pulsation. Two fundamental interdependent pulsation flow phenomena were observed: variable reductions in signal intensity of pulsatile CSF (signal loss) and spatial mismapping of this signal beyond the confines of the subarachnoid space (phase-shift images). Phase-shift images were observed as multiple regions of signal intensity conforming morphologically to the subarachnoid space but displaced symmetrically from it along the phase-encoding axis, either added to or subtracted from stationary signal intensity. Both CSF pulsation flow phenomena occurred secondary to harmonic modulation of proton precessional phase (temporal phase shift) by the unique pulsatile motion of spinal CSF when the repetition time was not an integral multiple of the pulsation period. Each flow phenomenon was analyzed with the spine phantom independently to control individual imaging and physiologic parameters including imaging plane, repetition time, echo time, slice thickness, number of echoes, number of excitations, CSF pulsation amplitude, and CSF pulsation period. In the axial plane, signal loss was present on both first- and second-echo images and was more pronounced with larger pulsation amplitudes and smaller slice thicknesses. A quantitative relationship between these two parameters allowed the prediction of CSF pulsation amplitude when the slice thickness was known and the CSF signal intensity was measured. In the sagittal plane, signal loss was present on first-echo images, was more pronounced with larger pulsation amplitudes, and under-went incomplete even-echo rephasing on second-echo images. Phase-shift images were influenced by the relationship between repetition time and CSF pulsation period. They were partly eliminated on sagittal but not on axial second-echo images because of incomplete even-echo rephasing. Both signal loss and phase-shift images were completely eliminated with CSF gating or pseudogating, indicating the rationale for gating during clinical spinal MR. The clinical significance of these findings is that awareness of the existence of spinal CSF pulsation flow phenomena avoids diagnostic confusion, whereas understanding their etiology provides a rational approach, such as CSF gating, to eliminate them.
Housing for an Aging Population

We use the American Housing Survey to examine the distribution and occupancy of homes that have, or could be modified to have, accessibility features that allow seniors to successfully remain in the community as they age. Despite the aging population and the growing need for accessible housing, the U.S. housing stock is woefully inadequate: fewer than 4% of housing units could be considered livable by people with moderate mobility difficulties, and a miniscule fraction are wheelchair accessible. Recent construction is no more likely to be accessible than homes built in the mid-1990s, suggesting that the housing market is not responding to the aging demographic profile. Only a small fraction of seniors, even among those with mobility difficulties, and even among recent movers, live in suitable homes. Modifications that potentially improve accessibility are more likely undertaken by households with a senior, but only once that senior develops mobility difficulties.
Impact of six months of GnRH agonist therapy for endometriosis. Is there an age-related effect on bone mineral density?

OBJECTIVE: To determine if there is an age-related effect on bone mineral density (BMD) loss with GnRH agonist treatment of endometriosis and, in particular, whether the impact of this therapy in terms of BMD loss is different if it is used at an age prior to attainment of peak BMD than after attaining it. STUDY DESIGN: Data from a randomized, double-placebo-controlled clinical trial comparing efficacy and safety of two GnRH agonists, without add-back, for the treatment of endometriosis, were analyzed. RESULTS: No significant age-related effect was detected for either GnRH agonist on absolute BMD loss with a single, six-month course. However, in women at an age prior to peak BMD, prevention of the natural increase in BMD with these drugs may prevent women from attaining their peak BMD and thus increase their risk of osteoporosis in later life. CONCLUSION: GnRH agonists should be used with caution and perhaps only with strategies designed to minimize the impact on BMD in women prior to attainment of peak BMD.
Propagating Waves as a Cortical Mechanism of Direction-Selectivity in V1 Motion Cells

The majority of neurons in primary visual cortex respond preferentially to moving bars of light with a specific orientation and direction of motion. The directional selectivity of those neurons implies that their responses cannot be achieved with separate spatial and temporal neural processes. How cortical neurons achieve non-separable space-time responses is still a mystery. We present a mathematical model of visual cortex in which neurons are predisposed to traveling waves of activity in a given anatomical direction. Those neurons resonate vigorously with moving stimuli that have a similar space-time signature to the intrinsic traveling wave. Yet they are quiescent to stimulus motion in the opposite direction. The model demonstrates how direction-selectivity can arise from the spatiotemporal properties of intrinsic cortical activity without resort to explicit time delays.
Pharmacotherapy for premature ejaculation

Introduction: Four premature ejaculation (PE) subtypes are distinguished on the basis of the duration of the intravaginal ejaculation latency time (IELT), its course in life, and frequency of complaints. Since the 1930s oral drug treatment and local anesthetics have been used to treat PE. Apart from dapoxetine, all currently available drugs to treat PE (SSRIs, clomipramine, and local anesthetics) are off-label. Not only men with lifelong and acquired PE, but also men with normal IELT values may want to postpone their ejaculation time.Areas covered: The guideline of the International Society for Sexual Medicine for the treatment of PE has provided evidence-based recommendations for the pharmacotherapy of lifelong and acquired PE. Selective serotonin reuptake inhibitors (SSRIs) delay ejaculation by interfering with the serotonin (5-HT) neurotransmission system in the central nervous system. Attention is given not only to the well-known but also to the recently published, very rare side effects of SSRIs.Expe...
A prospective study of donor insemination recipients : secrecy, privacy, and disclosure

Objectives To study prospectively the attitudes and behaviors of heterosexual couples undergoing donor insemination. Design Couples undergoing donor insemination completed psychological questionnaires before treatment regarding psychiatric symptoms, self-esteem, marital adjustment, and their attitudes about privacy or disclosure. Participants Forty-one of 82 heterosexual couples participated. Measures A donor insemination questionnaire, a self-esteem scale, the Brief Symptom Inventory, and the Dyadic Adjustment scale were used. Results Psychiatric symptoms, self-esteem, and marital adjustment were all in the normal range. The amount of time taken by the couple to decide to do donor insemination was not related to reported psychiatric symptoms, self-esteem, marital adjustment, or marital satisfaction. Ninety-five percent of the couples believed a psychological consultation should be a mandatory part of the donor insemination treatment. The greatest concern the couples had about the donor child was its genetic and medical background. Thirty-eight percent of the couples did tell or planned to tell others about using donor insemination to conceive, and only 27% of the couples planned to tell the child of his or her donor origin. Conclusions The results of this study support those of others, which have indicated that the majority of donor reicipients are psychologically well adjusted and have average marital adjustment. In addition, this prospective study replicated the findings of other retrospective studies, indicating that most donor inseminiation recipients do not plan to tell the child of his or her donor origin. Additional prospective studies are needed to determine if attitudes and behavior regarding disclosure change over time.
Pattern-aided regression modeling and prediction model analysis

This paper first introduces a new style of regression models, namely pattern aided regression (PXR) models, aimed at representing accurate and interpretable prediction models. It also introduces a contrast pattern aided regression (CPXR) method, to build accurate PXR models in an efficient manner. In experiments, the PXR models built by CPXR are very accurate in general, often outperforming state-of-the-art regression methods by wide margins. From extensive experiments we also found that (1) regression modeling applications often involve complex diverse predictor-response relationships, which occur when the optimal regression models (of given regression model type) fitting distinct natural subgroups of data are highly different, and (2) state-of-the-art regression methods are often unable to adequately model such relationships. CPXR is also useful for analyzing how a given regression model makes prediction errors. This is an extended abstract of [6].
Twenty-four-hour work shifts, increased job demands, and elevated blood pressure in professional firefighters.

Purpose To investigate whether working conditions (number of 24-h shifts, number of calls, sedentary work, job strain, effort–reward imbalance, and physical demands) are associated with elevated blood pressure and hypertension among professional firefighters.
Persistent Homology on Grassmann Manifolds for Analysis of Hyperspectral Movies

The existence of characteristic structure, or shape, in complex data sets has been recognized as increasingly important for mathematical data analysis. This realization has motivated the development of new tools such as persistent homology for exploring topological invariants, or features, in large data sets. In this paper, we apply persistent homology to the characterization of gas plumes in time dependent sequences of hyperspectral cubes, i.e. the analysis of 4-way arrays. We investigate hyperspectral movies of Long-Wavelength Infrared data monitoring an experimental release of chemical simulant into the air. Our approach models regions of interest within the hyperspectral data cubes as points on the real Grassmann manifold Gk,i¾?n whose points parameterize the k-dimensional subspaces of $$\mathbb {R}^n$$Rn, contrasting our approach with the more standard framework in Euclidean space. An advantage of this approach is that it allows a sequence of time slices in a hyperspectral movie to be collapsed to a sequence of points in such a way that some of the key structure within and between the slices is encoded by the points on the Grassmann manifold. This motivates the search for topological features, associated with the evolution of the frames of a hyperspectral movie, within the corresponding points on the Grassmann manifold. The proposed mathematical model affords the processing of large data sets while retaining valuable discriminatory information. In this paper, we discuss how embedding our data in the Grassmann manifold, together with topological data analysis, captures dynamical events that occur as the chemical plume is released and evolves.
Off-shell hydrodynamics from holography

We outline a program for obtaining an action principle for dissipative fluid dynamics by considering the holographic Wilsonian renormalization group applied to systems with a gravity dual. As a first step, in this paper we restrict to systems with a non-dissipative horizon. By integrating out gapped degrees of freedom in the bulk gravitational system between an asymptotic boundary and a horizon, we are led to a formulation of hydrodynamics where the dynamical variables are not standard velocity and temperature fields, but the relative embedding of the boundary and horizon hypersurfaces. At zeroth order, this action reduces to that proposed by Dubovsky et al. as an off-shell formulation of ideal fluid dynamics.
Relaxation from particle production

We consider using particle production as a friction force by which to implement a “Relaxion” solution to the electroweak hierarchy problem. Using this approach, we are able to avoid superplanckian field excursions and avoid any conflict with the strong CP problem. The relaxation mechanism can work before, during or after inflation allowing for inflationary dynamics to play an important role or to be completely decoupled.
Precision, Recall, and Sensitivity of Monitoring Partially Synchronous Distributed Systems

Runtime verification focuses on analyzing the execution of a given program by a monitor to determine if it is likely to violate its specifications. There is often an impedance mismatch between the assumptions/model of the monitor and that of the underlying program. This constitutes problems especially for distributed systems, where the concept of current time and state are inherently uncertain. A monitor designed with asynchronous system model assumptions may cause false-positives for a program executing in a partially synchronous system: the monitor may flag a global predicate that does not actually occur in the underlying system. A monitor designed with a partially synchronous system model assumption may cause false negatives as well as false positives for a program executing in an environment where the bounds on partial synchrony differ (albeit temporarily) from the monitor model assumptions.
On the efficacy of sampled-data modelling of switched networks

The limitations of sampled-data modelling in determining frequency response of switched networks such as switching power converters are highlighted. A general scheme for constructing small-signal difference equations used in sampled-data models is given. This scheme overcomes the limitations of current approaches used in obtaining input-to-output responses. However, in common with all other sampled-data modelling approaches, problems of accuracy and appropriate choice of formulation of difference equations still remain. Consequently, use of sampled-data models to determine frequency response is not recommended. However, the difference equation formulation scheme developed here may be used in a small-signal describing function modelling approach which is here demonstrated to be accurate, have no ambiguity of use and no frequency limitations in contrast to sampled-data modelling.
Water vapor δ2H, δ18O and δ17O measurements using an off-axis integrated cavity output spectrometer – sensitivity to water vapor concentration, delta value and averaging-time

RATIONALE High-precision analysis of atmospheric water vapor isotope compositions, especially δ(17) O values, can be used to improve our understanding of multiple hydrological and meteorological processes (e.g., differentiate equilibrium or kinetic fractionation). This study focused on assessing, for the first time, how the accuracy and precision of vapor δ(17) O laser spectroscopy measurements depend on vapor concentration, delta range, and averaging-time. METHODS A Triple Water Vapor Isotope Analyzer (T-WVIA) was used to evaluate the accuracy and precision of δ(2) H, δ(18) O and δ(17) O measurements. The sensitivity of accuracy and precision to water vapor concentration was evaluated using two international standards (GISP and SLAP2). The sensitivity of precision to delta value was evaluated using four working standards spanning a large delta range. The sensitivity of precision to averaging-time was assessed by measuring one standard continuously for 24 hours. RESULTS Overall, the accuracy and precision of the δ(2) H, δ(18) O and δ(17) O measurements were high. Across all vapor concentrations, the accuracy of δ(2) H, δ(18) O and δ(17) O observations ranged from 0.10‰ to 1.84‰, 0.08‰ to 0.86‰ and 0.06‰ to 0.62‰, respectively, and the precision ranged from 0.099‰ to 0.430‰, 0.009‰ to 0.080‰ and 0.022‰ to 0.054‰, respectively. The accuracy and precision of all isotope measurements were sensitive to concentration, with the higher accuracy and precision generally observed under moderate vapor concentrations (i.e., 10000-15000 ppm) for all isotopes. The precision was also sensitive to the range of delta values, although the effect was not as large compared with the sensitivity to concentration. The precision was much less sensitive to averaging-time than the concentration and delta range effects. CONCLUSIONS The accuracy and precision performance of the T-WVIA depend on concentration but depend less on the delta value and averaging-time. The instrument can simultaneously and continuously measure δ(2) H, δ(18) O and δ(17) O values in water vapor, opening a new window to better understand ecological, hydrological and meteorological processes. Copyright © 2016 John Wiley & Sons, Ltd.
Role of SNARE proteins in epithelial apical lumen formation

E morphogenesis is a fundamental process characterized by the emergence of ducts and acini, in which a polarized epithelial cell layer attached to a basal lamina surrounds a luminal space. Acute injury of major epithelial organ systems is one of the most important causes of death worldwide, and understanding the polarization of epithelia will be important in analyzing the response of a tissue to acute injury and in developing regeneration-based therapies. Studies of epithelial cells in 3D cultures and in vivo models have shown that lumen formation depends on a complex series of events, including: stimulation of morphogenesis, for example by cues such as cell attachment (to either other cells or the extracellular matrix); apical-basal polarization; lumen expansion. It is also clear that intracellular vesicle transport pathways are important for epithelial-gland morphogenesis, but our understanding of how they are regulated remains unclear. Soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins contribute to intracellular cargo transport by regulating the fusion of donor vesicles to their target membranes. Our published studies using human endothelial cells have shown that syntaxin 6 (Stx6), a member of the target membrane-associated SNARE (t-SNARE) family protein plays an important role in VEGFR2/KDR and alpha5 beta1 integrin trafficking and angiogenesis [Blood 117, 1425-35 (2011); J Biol Chem. 286, 36749-61 (2011)]. In contrast, confluent 2D and 3D epithelial cell cyst culture show downregulation of Stx6 with concomitant up-regulation of Stx16, suggesting a role for Stx16 in morphogenesis. Furthermore, Stx16 knockdown in epithelial cells show defect in morphogenesis and forms multiple lumens in 3D cysts. Ongoing studies in the lab are investigating role for Stx16 in the protein and lipid trafficking patterns that are required to maintain the cell-cell adhesion and cell polarity, events that are essential to achieve epithelial lumen formation. These studies may provide a better understanding of the fundamental mechanisms that regulate cell polarization, information that will be needed to improve the response of tissues to acute injury as well as to identify ways to avoid fibrosis and EMT after chronic injury.
Trade Credit and Industry Dynamics: Evidence from Trucking Firms

Long payment terms are a strong impediment to the entry and survival of liquidity-constrained firms. To test this idea and its implications, I consider the effect of a reform restricting the trade credit supply of French trucking firms. In a difference-in-differences setting, I find that trucking firms' corporate default probability decreases by 25% following the restriction. The effect is persistent, concentrated among liquidity-constrained firms, and not offset by a decrease in profits. The restriction also triggers an increase in the entry of small trucking firms.