cssi/SciSciGPT-SciSciNet huggingface dataset:
Electronic transport in polycrystalline graphene

Most materials in available macroscopic quantities are polycrystalline. Graphene, a recently discovered two-dimensional form of carbon with strong potential for replacing silicon in future electronics, is no exception. There is growing evidence of the polycrystalline nature of graphene samples obtained using various techniques. Grain boundaries, intrinsic topological defects of polycrystalline materials, are expected to markedly alter the electronic transport in graphene. Here, we develop a theory of charge carrier transmission through grain boundaries composed of a periodic array of dislocations in graphene based on the momentum conservation principle. Depending on the grain-boundary structure we find two distinct transport behaviours--either high transparency, or perfect reflection of charge carriers over remarkably large energy ranges. First-principles quantum transport calculations are used to verify and further investigate this striking behaviour. Our study sheds light on the transport properties of large-area graphene samples. Furthermore, purposeful engineering of periodic grain boundaries with tunable transport gaps would allow for controlling charge currents without the need to introduce bulk bandgaps in otherwise semimetallic graphene. The proposed approach can be regarded as a means towards building practical graphene electronics.
Phosphatidylhydroxyalkanols as Versatile Intermediates in the Synthesis of Headgroup Modified Diacetylenic Phospholipids

Abstract Phospholipase D extract (from savoy cabbage) mediates exchange of omega hydroxyalkanols (n= 2−4) with the choline moiety of phosphatidylcholines to produce corresponding phosphatidylhydroxyalkanols in > 70% yield. The phosphatidyl hydroxyalkanol and its chloro analogue were further reacted with molecules containing carboxylic and amine functionality respectively, providing an easy and efficient method to produce headgroup modified phospholipids.
Tangle analysis of difference topology experiments: applications to a Mu protein-DNA complex

We develop topological methods for analyzing difference topology experiments involving 3‐string tangles. Difference topology is a novel technique used to unveil the structure of stable protein-DNA complexes. We analyze such experiments for the Mu protein-DNA complex. We characterize the solutions to the corresponding tangle equations by certain knotted graphs. By investigating planarity conditions on these graphs we show that there is a unique biologically relevant solution. That is, we show there is a unique rational tangle solution, which is also the unique solution with small crossing number. 57M25, 92C40
A Survey of Quantum Programming Languages: History, Methods, and Tools

Quantum computer programming is emerging as a new subject domain from multidisciplinary research in quantum computing, computer science, mathematics (especially quantum logic, lambda calculi, and linear logic), and engineering attempts to build the first non-trivial quantum computer. This paper briefly surveys the history, methods, and proposed tools for programming quantum computers circa late 2007. It is intended to provide an extensive but non-exhaustive look at work leading up to the current state-of-the-art in quantum computer programming. Further, it is an attempt to analyze the needed programming tools for quantum programmers, to use this analysis to predict the direction in which the field is moving, and to make recommendations for further development of quantum programming language tools.
Frequency Sweeping With Concurrent Parametric Amplification

In this paper, we explore parametric amplification of multiple resonances in multidegree-of-freedom mechanical systems, and the use of frequency sweeping with a parametric pump to amplify several adjacent resonance peaks. We develop conditions under which it is possible to sweep with direct and parametric excitation to produce a sweep response with amplified effective quality factors for all resonances over a given frequency range. We determine gain and stability conditions and include analysis for potential problematic modal interactions. This technique makes it possible to improve the measurements of resonance locations in devices, for example, sensors that rely on tracking shifts in resonance peaks. The results are demonstrated on a model for a multi-analyte micro-electromechanical systems mass sensor.
Embeddedness and the Intellectual Projects of Economic Sociology

AbstractIn this review, we explore how the concept of embeddedness has shaped—and been shaped by—the evolution of the subfield of economic sociology. Although embeddedness is often taken as a conceptual umbrella for a single, if eclectic, approach to the sociological study of the economy, we argue that in fact the concept references two distinct intellectual projects. One project, following from Granovetter's (1985) well-known programmatic statement, attempts to discern the relational bases of social action in economic contexts. Another project, drawing from Polanyi's [1944 (2001), 1957, 1977] social theory, concerns the integration of the economy into broader social systems. Critically, these two formulations of embeddedness involve different views of the relationship between the economic and the social. The implication is that the obstacles to theoretical integration in economic sociology, while not insurmountable, are greater than is typically acknowledged.
Evaluating tradable property rights for natural resources: The role of strategic entry and exit

This paper presents an econometric approach to the evaluation of environmental regulation using tradable property rights. Existing empirical research on this issue, which compares overall industry efficiency before and after the introduction of new regulations, conflates two distinct phenomena: efficiency changes due to exit of excess capital, and changes in the efficiency of individual firms. Because the regulatory process induces firms of different types to enter and exit the industry at different rates, the true efficiency and equity effects of tradable property rights cannot be assessed without correcting for these changes in sample composition. This paper examines the impact of regulatory change in the Mid-Atlantic surf clam fishery, using an econometric model that separates its effects on industry structure and vessel efficiency. The analysis finds that, contrary to widely held belief, tradable property rights did not disproportionately benefit either large fishing firms or highly integrated firms.
Power Spectra Estimation for Weak Lensing

We develop a method for estimating the shear power spectra from weak-lensing observations and test it on simulated data. Our method describes the shear field in terms of angular power spectra and the cross-correlation of the two shear modes, which differ under parity transformations. Two of the three power spectra can be used to monitor unknown sources of noise in the data. The power spectra are decomposed in a model-independent manner in terms of "band powers," which are then extracted from the data using a quadratic estimator to find the maximum of the likelihood and its local curvature (for error estimates). We test the method against simulated data from Gaussian realizations and cosmological N-body simulations. In the Gaussian case, the mean band powers and their covariance are well recovered even for irregular (or sparsely) sampled fields. The mild non-Gaussianity of the N-body realizations causes a slight underestimation of the errors that becomes negligible for scales much larger than several arcminutes and does not bias the recovered band powers. These techniques can also be directly applied to cosmic microwave background polarization E and B mode analyses on small fields.
A Decade of Declining Earnings Inequality in the Russian Federation

Wage inequality decreased significantly in the Russian Federation over the 2000s. The economic expansion experienced throughout the decade led to an improvement in social indicators, with a large reduction in poverty rates and an increase in higher education. In this context, wage inequality showed a sharp decline, with the Gini index on labor income decreasing by 18 percent between 2002 and 2012. Using data from the Russian Longitudinal Monitoring Survey, this paper documents the reduction in wage inequality and explores potential factors behind the trend. The analysis uses a decomposition technique proposed by Fortin, Lemieux, and Firpo (2011) to disentangle the main drivers behind changes in the wage distribution. The results suggest that wage structure effects are more important than composition effects for explaining changes in wage inequality. Institutional factors, such as minimum wage policies and changes in the returns to employment in different sectors and types of firms as well as the reduction of the skill premium, emerge as the most relevant factors for explaining changes in the wage structure.
The latent relation mapping engine: algorithm and experiments

Many AI researchers and cognitive scientists have argued that analogy is the core of cognition. The most influential work on computational modeling of analogy-making is Structure Mapping Theory (SMT) and its implementation in the Structure Mapping Engine (SME). A limitation of SME is the requirement for complex hand-coded representations. We introduce the Latent Relation Mapping Engine (LRME), which combines ideas from SME and Latent Relational Analysis (LRA) in order to remove the requirement for hand-coded representations. LRME builds analogical mappings between lists of words, using a large corpus of raw text to automatically discover the semantic relations among the words. We evaluate LRME on a set of twenty analogical mapping problems, ten based on scientific analogies and ten based on common metaphors. LRME achieves human-level performance on the twenty problems. We compare LRME with a variety of alternative approaches and find that they are not able to reach the same level of performance.
A dynamic model for microstrip-slotline transition and related structures

An analysis of microstrip-to-slotline transition is presented. The method of moments is applied to the coupled integral equations. In the formulation, the Green's function for the grounded dielectric substrate, which takes into account all the radiation, surface wave, and substrate effects, is used. Meanwhile, all the mutual coupling effects are included in the method of moments solution. Certain related structures, such as slotline and microstrip discontinuities, a slot fed by a microstrip line, and a printed strip dipole fed by a slotline, can also be solved with this analysis. This approach may find applications to other related transitions in MIC (microwave integrated circuit) design. >
Performance Measurements of a Cylindrical Glass Honeycomb Solar Collector Compared With Predictions

A glass tube honeycomb solar collector, composed of a conventional single-glazed flat-plate water cooled nonselective black absorber with a cylindrical glass honeycomb mounted between the plate and cover glass, was designed, fabricated, and tested. The test procedure followed the National Bureau of Standards Method of Testing for Rating Solar Collectors. The honeycomb consists of individual cylindrical thin-wall glass tubes standing on end on the absorber plate in a hexagonal close-packed pattern. The tubes are 9.5-mm ID, 0.2-mm wall thickness, 5.3 length to diameter ratio made of glass with mean solar absorptive index (k-bar), 2.6 x 10/sup -6/ ..mu../sup -1/, evaluated from spectral transmittance-reflectance measurements on a tubing specimen. The collector performance equalled or surpassed theoretical predictions for measurements made over a broad range of collector inlet temperatures and environmental conditions. Performance comparisons are made with a base-line double-glazed solar collector tested alongside the honeycomb collector. For applications requiring a working fluid temperature of 65degreeC above the ambient air temperature, honeycomb collector efficiencies of 35--55 percent may be expected for approximately a six hour period on clear days; for fluid temperature 40degreeC above ambient air temperature, efficiencies of 50--65 percent may be expected.
Estimates of photoluminescence efficiencies in GaN nanowires at high injection levels from steady‐state photoluminescence measurements

Photoluminescence (PL) efficiencies were estimated for individual silicon-doped GaN nanowires grown by plasma assisted molecular beam epitaxy (PAMBE). Steady-state PL measurements reveal efficiencies that depend on excitation intensity, temperature, and nanowire morphology. While many nanowires had their best efficiencies at base temperature (T ∼ 4 K), some nanowires, given sufficient excitation intensities, had best efficiencies at elevated temperatures (T ∼ 100 K). Room-temperature internal quantum efficiency (IQE) of PL was as high as 33 ± 5%. These steady-state results corroborate with time-resolved PL measurements reported earlier, and both methods can aid in optimizing the growth and processing of nanowires for future applications in nanoscale optoelectronics. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
The concept of "stress" in the biological and social sciences

The concept of “stress” was applied to biological and social systems in the first half of this century because it appeared to provide an explanation for the apparently “non-specific” effects of bio...
The skip quadtree: a simple dynamic data structure for multidimensional data

We present a new multi-dimensional data structure, which we call the skip quadtree (for point data in R2) or the skip octree (for point data in Rd, with constant d > 2). Our data structure combines the best features of two well-known data structures, in that it has the well-defined "box"-shaped regions of region quadtrees and the logarithmic-height search and update hierarchical structure of skip lists. Indeed, the bottom level of our structure is exactly a region quadtree (or octree for higher dimensional data). We describe efficient algorithms for inserting and deleting points in a skip quadtree, as well as fast methods for performing point location, approximate range, and approximate nearest neighbor queries.
Measurement of the Universal Gas Constant R Using a Spherical Acoustic Resonator

• The uncer­ tainty in the new value is 1.7 ppm (stan­ dard error), a factor of 5 smaller than the uncertainty in the best previous value. The gas constant was determined from measurements of the speed of sound in argon as a function of pressure at the temperature of the triple point of water. The speed of sound was mea­ sured with a spherical resonator whose volume was determined by weighing the mercury required to fill it at the temperature of the tri~le point. The molar mass of the argon was determined by comparing the speed of sound in it to the speed of sound in a standard sample of argon of accurately known chemical and isotoptic composition.
Knowledge, Proximity and R&D Exodus

Abstract We explore not only how technological leaders and laggards react to agglomeration, but within an agglomeration we look at how the relative presence of other leaders, laggards and foreign firms affects these firms. Existing literature argues that technological leaders experience net knowledge outflows and are therefore losers in agglomerations. However, we do not know if they avoid locations with laggards more so than locations with leaders or vice versa, thus we examine how the relative presence of each affects leaders’ location decisions. For technologically lagging firms, we argue they will prefer locations with leaders over locations with laggards. We further posit that an increasing presence of foreign firms will have a particularly detrimental effect on technologically leading domestic firms, as these lose out in the contest for talent. Contextualized in an emerging market with weak intellectual property rights protection, we examine whether these concerns about knowledge spillovers and competition for talent prompt firms to close their R&D facilities or remain open. Using 5798 observations of R&D laboratories in India during 2003–2011, we find that while technologically leading firms are more likely to close their R&D facilities as the presence of other domestic labs increases, laggards are less likely to do so. These findings suggest concerns over knowledge spillovers are present, especially on the part of technologically leading firms. Moreover, leaders are more concerned by the presence of other leaders. Technologically lagging firms, by contrast, are less likely to close R&D facilities in the face of these concerns and will prefer staying near leaders over laggards. Finally, we find evidence of foreign firms crowding out domestic technological leaders but not laggards in the competition for talent.
Nucleophilic amination of 2-iodo-3-nitro-1-(phenylsulfonyl)indole

Abstract The reaction of 2-iodo-3-nitro-1-(phenylsulfonyl)indole ( 2 ) with amines affords the corresponding 2-amino-3-nitroindoles in excellent yields via nucleophilic aromatic substitution.
Shortening Array Codes and the Perfect $1$ -Factorization Conjecture

The existence of a perfect 1-factorization of the complete graph with n nodes, namely, Kn , for arbitrary even number n, is a 40-year-old open problem in graph theory. So far, two infinite families of perfect 1-factorizations have been shown to exist, namely, the factorizations of Kp+1 and K2 p , where p is an arbitrary prime number (p > 2) . It was shown in previous work that finding a perfect 1 -factorization of Kn is related to a problem in coding, specifically, it can be reduced to constructing an MDS (Minimum Distance Separable), lowest density array code. In this paper, a new method for shortening arbitrary array codes is introduced. It is then used to derive the Kp+1 family of perfect 1 -factorization from the K2p family. Namely, techniques from coding theory are used to prove a new result in graph theory-that the two factorization families are related.
Room temperature dehalogenation of chloroarenes by polymethylhydrosiloxane (PMHS) under palladium catalysis

The first method for the reduction of chloroarenes by polymethylhydrosiloxane (PMHS) is reported. Catalytic amounts of palladium(II) acetate in combination with PMHS and aqueous KF will rapidly hydrodehalogenate aryl chlorides at room temperature. The mildness of the method is demonstrated by its tolerance of ketones, amides, esters, nitriles, ethers, borate esters, and amines.
Development of an automated oligosaccharide synthesizer.

Publisher Summary This chapter discusses an approach for the development of an automated oligosaccharide synthesizer. To meet the demand for molecular tools, new methods for the rapid production of carbohydrates are needed. Carbohydrates are the most stereochemically challenging class of biopolymers to prepare, and different methods have been developed to address their synthesis. In addition to traditional solution-phase chemical synthesis, three methods—enzymatic methods, orthogonal one-pot chemical methods, and automated solid-phase methods—have become increasingly popular for the construction of oligosaccharides. The chapter develops an automated solid-phase approach for the chemical synthesis of oligosaccharides. In this study, by using an acceptor-bound solid-phase glycosylation strategy in a specially designed instrument, poly α- (1 → 2) mannosides as large as a decasaccharide were synthesized. The use of glycosyl phosphates was demonstrated with the synthesis of a dodecamer phytoalexin elicitor b-glucan. During this investigation, high-resolution magic angle-spinning nuclear magnetic resonance (HR-MAS NMR) analysis was used as an on-resin analytical tool. The method described in the chapter is anticipated to have a significant impact on the field of oligosaccharide synthesis. Although there are still a number of challenges to overcome, the automated construction of glycosidic linkages is expected to allow for the preparation of a diverse set of carbohydrate for pharmaceutical and biochemical evaluation.
Scanning interference evanescent wave lithography for sub-22-nm generations

Large field, ultra-high numerical aperture (NA) lithography is desired in semiconductor manufacturing. We report progress in developing a scanning evanescent wave lithography (s -EWL) imaging head with a two-stage gap control system including a DC noise canceling air bearing, which houses an AC noise-canceling piezoelectric actuator. Various design aspects of the system, including gap detection, prism design, optical alignment, software integration, feedback actuation, and a scanning scheme have been developed to ensure sub-100-nm gap control. Experimental results have shown successful gap gauging with a gap noise root-mean-square (RMS) of 1.38 nm in static gap control, and 4.64 nm in linear scanning gap control. Integrating the prototype imaging head into a two-beam interferometer platform has demonstrated dynamic stepping imaging using fused silica and sapphire prisms, with potential NA values up to 1.85 (26-nm half-pitch). These results achieved with s -EWL provide a possible route to extend optical lithography to 16-nm generations and beyond when combined with double patterning techniques.
The obstacle problem for the p-laplacian via optimal stopping of tug-of-war games

We present a probabilistic approach to the obstacle problem for the p-Laplace operator. The solutions are approximated by running processes determined by tug-of-war games plus noise, and letting the step size go to zero, not unlike the case when Brownian motion is approximated by random walks. Rather than stopping the process when the boundary is reached, the value function is obtained by maximizing over all possible stopping times that are smaller than the exit time of the domain.
Distributed processes: a concurrent programming concept

A language concept for concurrent processes without common variables is introduced. These processes communicate and synchronize by means of procedure calls and guarded regions. This concept is proposed for real-time applications controlled by microcomputer networks with distributed storage. The paper gives several examples of distributed processes and shows that they include procedures, coroutines, classes, monitors, processes, semaphores, buffers, path expressions, and input/output as special cases.
A novel series of urea-based peptidomimetic calpain inhibitors

A series of peptide aldehyde derivatives in which the P(2) chiral carbon has been replaced with nitrogen were synthesized as urea-based peptidomimetic inhibitors of mu-calpain. The compounds mirrored the general SAR of peptidyl aldehyde calpain inhibitors but displayed greater selectivity for mu-calpain over cathepsin B.
Novel cyclourethane-Derived HIV protease inhibitors: A ring-closing olefin metathesis based strategy

A series of novel macrocyclic urethanes incorporating a (R)-hydroxyethylamine isostere was designed and synthesized. Ring size and substituent efffects have been investigated. Cyclourethanes containing 14- to 16-membered rings exhibited low nanomolar inhibitory potencies against HIV-1 protease.
Dynamic Modulus Prediction of Asphalt Concrete Mixtures Through Computational Micromechanics

This paper presents a computational micromechanics modeling approach to predict the dynamic modulus of asphalt concrete mixtures. The modeling uses a finite element method combined with the micromechanical representative volume element (RVE) of mixtures and laboratory tests that characterize the properties of individual mixture constituents. The model treats asphalt concrete mixtures as heterogeneous with two primary phases: a linear viscoelastic fine aggregate matrix (FAM) phase and a linear elastic aggregate phase. The mechanical properties of each phase were experimentally obtained by conducting constitutive tests: oscillatory torsion tests for the viscoelastic FAM phase and quasistatic nanoindentation tests for the elastic aggregate particles. Material properties of each mixture phase were then used in the finite element simulation of two-dimensional mixture microstructures obtained from digital image processes of asphalt concrete mixtures. Model simulations were compared with the experimental dynamic...
Crisis Communication – Creating Media Partners for Transportation Disasters

The 24-hour news cycle is a phenomenon that is here to stay. As transportation professionals we must learn to control this phenomenon with confidence and finesse, especially when it relates to transportation incidents and accidents. The media should not be viewed as the enemy, but as a potential partner who can assist with providing, obtaining, and disseminating critical information to populations who have an interest and/or stake in the event that has occurred. Previously viewed as “just another function” of the public relations department, research in the areas of communications and mass media has discovered that the communication processes used during a disaster (crisis) of any type have become highly specialized. Traditional public relations skills and training provide a base knowledge, but specially trained individuals are needed to create and maintain a cooperative partnership with the media, in an effort to control the message to reduce unsubstantiated accusations, disclosures, and panic. A Purdue University aviation technology researcher as been working with communication and media professionals to develop crisis / disaster communication programs and processes needed to handle the delicate and demanding area of crisis communication for the transportation industry. This paper shows the effects of using specialized programs to develop positive and trusting relationships with media (and other populations) during times of normal operations, and how these partnerships can be used to handle crisis communication in a controlled and positive manner. In addition, the paper addresses the need for specialized training in the area of crisis communication, and discusses programs to provide this training. Crisis communication is not an element transportation professionals can leave to chance, or rely on the basic skills of public relations professionals to handle efficiently. In this era of 24-hour, on-demand news we must be proactive in establishing communication processes and programs to provide accurate and timely information to maintain the public’s trust during a time of crisis. The inability to properly manage crisis communication can lead to public mistrusted, unwarranted suffering, and devastating economic problems for an organization.
Instance-Based Action Models for Fast Action Planning

Two main challenges of robot action planning in real domains are uncertain action effects and dynamic environments. In this paper, an instance-basedaction model is learned empirically by robots trying actions in the environment. Modeling the action planning problem as a Markov decision process, the action model is used to build the transition function. In static environments, standard value iteration techniques are used for computing the optimal policy. In dynamic environments, an algorithm is proposed for fast replanning, which updates a subset of state-action values computed for the static environment. As a test-bed, the goal scoring task in the RoboCup 4-legged scenario is used. The algorithms are validated in the problem of planning kicks for scoring goals in the presence of opponent robots. The experimental results both in simulation and on real robots show that the instance-based action model boosts performance over using parametric models as done previously, and also incremental replanning significantly improves over original off-line planning.
A general framework of automorphic inflation

Automorphic inflation is an application of the framework of automorphic scalar field theory, based on the theory of automorphic forms and representations. In this paper the general framework of automorphic and modular inflation is described in some detail, with emphasis on the resulting stratification of the space of scalar field theories in terms of the group theoretic data associated to the shift symmetry, as well as the automorphic data that specifies the potential. The class of theories based on Eisenstein series provides a natural generalization of the model of j-inflation considered previously.
Network-level effects of kinase inhibitors modulate TNF-α–induced apoptosis in the intestinal epithelium

Individual signaling pathways operate in the context of the broader signaling network. Thus, the response of a cell to signals from the environment is affected by the state of the signaling network, such as the clinically relevant example of whether some components in the network are inhibited. The cytokine tumor necrosis factor-α (TNF-α) promotes opposing cellular behaviors under different conditions; the outcome is influenced by the state of the network. For example, in the mouse intestinal epithelium, inhibition of the mitogen-activated protein kinase (MAPK) kinase MEK alters the timing of TNF-α-induced apoptosis. We investigated whether MAPK signaling directly influences TNF-α-induced apoptosis or whether network-level effects secondary to inhibition of the MAPK pathway alter the cellular response. We found that inhibitors of the MAPK kinase kinase Raf, MEK, or extracellular signal-regulated kinase (ERK) exerted distinct effects on the timing and magnitude of TNF-α-induced apoptosis in the mouse intestine. Furthermore, even different MEK inhibitors exerted distinct effects; one, CH5126766, potentiated TNF-α-induced apoptosis, and the others reduced cell death. Computational modeling and experimental perturbation identified the kinase Akt as the primary signaling node that enhanced apoptosis in the context of TNF-α signaling in the presence of CH5126766. Our work emphasizes the importance of integrated network signaling in specifying cellular behavior in response to experimental or therapeutic manipulation. More broadly, this study highlighted the importance of considering the network-level effects of pathway inhibitors and showed the distinct effects of inhibitors that share the same target.
Semidefinite programs on sparse random graphs and their application to community detection

Denote by A the adjacency matrix of an Erdos-Renyi graph with bounded average degree. We consider the problem of maximizing over the set of positive semidefinite matrices X with diagonal entries X_ii=1. We prove that for large (bounded) average degree d, the value of this semidefinite program (SDP) is --with high probability-- 2n*sqrt(d) + n, o(sqrt(d))+o(n). For a random regular graph of degree d, we prove that the SDP value is 2n*sqrt(d-1)+o(n), matching a spectral upper bound. Informally, Erdos-Renyi graphs appear to behave similarly to random regular graphs for semidefinite programming. We next consider the sparse, two-groups, symmetric community detection problem (also known as planted partition). We establish that SDP achieves the information-theoretically optimal detection threshold for large (bounded) degree. Namely, under this model, the vertex set is partitioned into subsets of size n/2, with edge probability a/n (within group) and b/n (across). We prove that SDP detects the partition with high probability provided (a-b)^2/(4d)> 1+o_d(1), with d= (a+b)/2. By comparison, the information theoretic threshold for detecting the hidden partition is (a-b)^2/(4d)> 1: SDP is nearly optimal for large bounded average degree. Our proof is based on tools from different research areas: (i) A new 'higher-rank' Grothendieck inequality for symmetric matrices; (ii) An interpolation method inspired from statistical physics; (iii) An analysis of the eigenvectors of deformed Gaussian random matrices.
Student understanding of the Boltzmann factor

Research to help students understand the physical significance and applicability of the Boltzmann factor.
An Entropy Satisfying Discontinuous Galerkin Method for Nonlinear Fokker---Planck Equations

We propose a high order discontinuous Galerkin method for solving nonlinear Fokker---Planck equations with a gradient flow structure. For some of these models it is known that the transient solutions converge to steady-states when time tends to infinity. The scheme is shown to satisfy a discrete version of the entropy dissipation law and preserve steady-states, therefore providing numerical solutions with satisfying long-time behavior. The positivity of numerical solutions is enforced through a reconstruction algorithm, based on positive cell averages. For the model with trivial potential, a parameter range sufficient for positivity preservation is rigorously established. For other cases, cell averages can be made positive at each time step by tuning the numerical flux parameters. A selected set of numerical examples is presented to confirm both the high-order accuracy and the efficiency to capture the large-time asymptotic.
Fast temporal dynamics of visual cue integration

We study the dynamics of visual cue integration in a tracking / identification task, where subjects track a target object among distractors and identify the target after an occlusion. Objects are defined by three different attributes (color, shape, size) which change randomly within a singe trial. When the attributes differ in their reliability (two change frequently, one is stable) our results show that subjects rapidly re-weight the different cues, putting more emphasis on the stable cue. The re-weighting takes place in less than one second. Our results suggest that cue integration can exhibit adaptive phenomena on a very fast time scale. We propose a probabilistic model with temporal dynamics that accounts for the observed effect.
Low-Temperature Heat Capacity of Liquid He 3

The heat capacity of pure ${\mathrm{He}}^{3}$ has been measured using a difference method from 6 to 50 m\ifmmode^\circ\else\textdegree\fi{}K at 0.28 atm and from 4 to 30 m\ifmmode^\circ\else\textdegree\fi{}K at 27.0 atm. In neither case is the ratio of heat capacity to temperature constant over the range of temperature of the measurements. Moreover, the high- and low-pressure heat capacities seem to have qualitatively different temperature dependences. The raw heat-capacity data down to a temperature [on the magnetic temperature scale valid for powdered cerium magnesium nitrate (CMN) in the form of a right circular cylinder with diameter equal to height] of 2 m\ifmmode^\circ\else\textdegree\fi{}K at 0.28 atm and 4 m\ifmmode^\circ\else\textdegree\fi{}K at 27.0 atm show no evidence for anomalous behavior. As a by-product of the measurements the heat capacity of the CMN cooling salt was also obtained.
Lactate and ventilatory thresholds: disparity in time course of adaptations to training

We tested the hypothesis that the lactate threshold (Tlac) during incremental exercise could be increased significantly during the first 3 wk of endurance training without any concomitant change in...
Diphotons, new vacuum angles, and strong CP

The Standard Model contains a well-understood, natural, spin-0 diphoton resonance: the π 0. Numerous studies have pointed out that the hint of a new diphoton resonance at 750 GeV could be a pion analog, identified with the pseudo-Nambu-Goldstone boson of a chiral symmetry spontaneously broken by new strong dynamics at the TeV scale. These “hypercolor” models are generically expected to violate parity through a topological angle $$ \tilde{\theta} $$ . We discuss the physics of $$ \tilde{\theta} $$ and its impact on the phenomenology of the new sector. We also describe some of the theoretical implications of a nonzero $$ \tilde{\theta} $$ . In particular, $$ \tilde{\theta} $$ can generate an $$ \mathcal{O}(1) $$ threshold correction to the QCD vacuum angle θ near the TeV scale, sharply constraining ultraviolet solutions to the strong CP problem. Alternatively, finding that $$ \tilde{\theta} $$ is small may be interpreted as evidence in favor of UV solutions to strong CP, particularly those based on spontaneously broken P or CP symmetries.
Enhancing Sampling of the Conformational Space Near the Protein Native State

A protein molecule assumes specific conformations under native conditions to fit and interact with other molecules. Due to the role that three-dimensional structure plays in protein function, significant efforts are devoted to elucidating native conformations. Many search algorithms are proposed to navigate the high-dimensional protein conformational space and its underlying energy surface in search of low-energy conformations that comprise the native state. In this work, we identify two strategies to enhance the sampling of native conformations. We show that employing an enhanced fragment library with greater structural diversity to assemble low-energy conformations allows sampling more native conformations. To efficiently handle the ensuing vast conformational space, only a representative subset of the sampled conformations are maintained and employed to further guide the search for native conformations. Our results show that these two strategies greatly enhance the sampling of the conformational space near the native state.
Acquired spinal subarachnoid cysts: Evaluation with MR, CT, myelography, and intraoperative sonography

Fifteen patients with acquired spinal subarachnoid cysts (14 surgically proved, one presumed) were evaluated preoperatively with immediate and/or delayed CT myelography (seven patients), MR (11 patients), or both (three patients). CT myelography separated subarachnoid cyst from myelomalacia and/or intramedullary cysts in four cases but failed to diagnose them in three, while MR accurately diagnosed subarachnoid cyst in all 10 cases that were also surgically proved. The results of these preoperative examinations were evaluated to determine the efficacy of each study in diagnosing subarachnoid cysts, ascertaining their extent and internal architecture, and detecting associated abnormalities of the spinal cord. In addition, during surgery these cysts were studied with sonography to gain an understanding of the pathophysiological mechanisms involved in their formation and propagation and to guide the surgeon in their decompression. On the basis of our experience, MR appears to be the most efficient preoperative study in diagnosing and characterizing acquired subarachnoid cyst and associated abnormalities. Intraoperative sonography provides a reliable means of ensuring adequate decompression of these cysts.
Catalytic Enantioselective Synthesis of Amino Skipped Diynes

The Cu-catalyzed synthesis of nonracemic 3-amino skipped diynes via an enantiodetermining C–C bond formation is described using StackPhos as ligand. Despite challenging issues of reactivity and stereoselectivity inherent to these chiral skipped diynes, the reaction tolerates an extremely broad substrate scope with respect to all components and provides the title compounds in excellent enantiomeric excess. The alkyne moieties are demonstrated here to be useful synthetic handles, and 3-amino skipped diynes are convenient building blocks for enantioselective synthesis.
Communication and Collaboration in Synthetic Microbial Consortia

Elucidating and manipulating community-level behaviors of microorganisms holds tremendous potential for human health, biotechnology and bioprocessing. Robust, flexible cell-cell communication pathways are essential for controlling interactions and building synergies between different species of microorganism in synthetic microbial communities. To this end, we have developed new sets regulatory components and systems that can be used to turn gene expression on or off in response to a cell-cell communication signal, and enable interspecies communication between representative Gram-negative (Escherichia coli) and Gram-positive (Bacillus megaterium) organisms. An acyl-homoserine lactone (AHL)-dependent system was adapted to send signals from B. megaterium to E. coli. Components of a peptide-dependent microbial signaling pathway were used to send signals from E. coli to B. megaterium. The peptide-based communication elements have also been used to engineer an autoinduction system that enables density-dependent gene expression in B. megaterium. Finally, these new cell-cell communication systems are being used in concert with other ecological approaches to coordinate the growth, manipulate interactions and distribute functions between microbes.
Dynamic Ventilation and Power Output of Urban Bicyclists

Bicyclists’ intake of air pollutants is linked to physical exertion levels, ventilation rates, and exposure concentrations. Whereas exposure concentrations have been widely studied in transportation environments, there has been relatively scant research linking on-road ventilation with travel conditions and exertion levels. This paper investigates relationships between power output, heart rate, and ventilation rate for urban bicyclists. Heart rate and ventilation rate were measured on-road and combined with power output estimates from a bicycle power model. Dynamic ventilation rates increased by 0.4% to 0.8% per watt of power output, with a mean lag of 0.8 min. The use of physiology (ventilation) monitoring straps and heart rate proxies for dynamic on-road ventilation measurements is discussed. This paper provides for a clearer and more quantitative understanding of bicyclists’ ventilation and power output, which is useful for studies of pollutant inhalation risks, energy expenditure, and physical activity.
Gender and Policy Roles in Farm Household Diversification in Zambia

Summary Many African governments, faced with low rural incomes and food security challenges, have developed input subsidy programs in order to enhance agricultural productivity. This paper adds to recent literature analyzing the effects of input subsidy programs and gender on crop diversification in Sub-Saharan Africa. We investigate the effect of Zambia’s input subsidy program on crop allocation patterns by gender. In relatively land abundant Zambia, we test both single-equation crop diversification index models and multivariate regression models of cropland allocation. Our study finds that input subsidies reduce crop diversification more in male-headed households than in female-headed households. Further, multivariate regression results confirm that this occurs because female-headed households expand maize acreage less in response to the input subsidy. These findings suggest that greater cropland diversification will be maintained if input subsidy programs are accompanied by loan programs and other assistance which support leadership roles for women in farm households.
Transportation Usage and Characteristics of the Washington Warehouse/Distribution Center Industry

It is estimated that there are 21.6 million truck trips made each year on Washington state highways. It is further estimated that 45% of transported freight originated from or is destined for a warehouse or distribution center within the state. The growing amount of congestion within the state of Washington has prompted concern over the state’s ability to anticipate and provide for current and future freight transportation infrastructure needs. The objective of this study was to determine freight mobility issues for the Warehouse/Distribution Center industry in Washington State. The scope of this project was primarily two-fold:, to assess the operations of Warehouse/Distribution Centers and to evaluate infrastructure adequacy, and identify deficiencies and investment needs related to transportation. The sample used for this study was compiled from local, county, state, and federal agencies. Collected information was categorized by the Standard Industrial Classification (SIC) or North American Industry Classification System (NAICS) codes associated with industries that operate in the storage and distribution of freight. The data collection method chosen for this study was a mail survey. The survey questionnaire and subsequent analysis were divided into four sections: Warehouse Operations, Inter-modal Systems, International Trade, and Other Transportation Related Issues. The information collected includes the following: 􀂃 Warehouse/distribution center characteristics (hours of operation, square footage of facility, and type of products handled) 􀂃 Daily time distribution of inbound and outbound shipments 􀂃 Mode distribution among inbound and outbound shipments 􀂃 Key routes utilized for inbound and outbound shipments 􀂃 Country of origin and destination of products 􀂃 Mode distribution among imports and exports 􀂃 Ranking of transportation issues 􀂃 Indicators of freight chokepoints The paper provides an analysis and overview of the operations and needs of the warehouse/distribution center industry in the state of Washington.
Design and characterization of integrated components for SiN photonic quantum circuits

The design, fabrication, and detailed calibration of essential building blocks towards fully integrated linear-optics quantum computation are discussed. Photonic devices are made from silicon nitride rib waveguides, where measurements on ring resonators show small propagation losses. Directional couplers are designed to be insensitive to fabrication variations. Their offset and coupling lengths are measured, as well as the phase difference between the transmitted and reflected light. With careful calibrations, the insertion loss of the directional couplers is found to be small. Finally, an integrated controlled-NOT circuit is characterized by measuring the transmission through different combinations of inputs and outputs. The gate fidelity for the CNOT operation with this circuit is estimated to be 99.81% after post selection. This high fidelity is due to our robust design, good fabrication reproducibility, and extensive characterizations.
Cyclopropenes in Metallacycle-Mediated Cross-Coupling with Alkynes: Convergent Synthesis of Highly Substituted Vinylcyclopropanes

Stereodivergent metallacycle-mediated cross-coupling reactions are described for the synthesis of densely functionalized vinylcyclopropanes from the union of alkynes with cyclopropenes. Strategies explored include hydroxyl-directed and nondirected processes, with the latter of these delivering vinylcyclopropanes with exquisite levels of regio- and stereoselectivity. Challenges inherent to these coupling reactions include diastereoselectivity (with respect to the cyclopropene) and regioselectivity (with respect to both coupling partners).
Mammary epithelial tubes elongate through MAPK-dependent coordination of cell migration

Mammary branching morphogenesis is regulated by receptor tyrosine kinases (RTKs). We sought to determine how these RTK signals alter proliferation and migration to accomplish tube elongation in mouse. Both behaviors occur but it has been difficult to determine their relative contribution to elongation in vivo, as mammary adipocytes scatter light and limit the depth of optical imaging. Accordingly, we utilized 3D culture to study elongation in an experimentally accessible setting. We first used antibodies to localize RTK signals and discovered that phosphorylated ERK1/2 (pERK) was spatially enriched in cells near the front of elongating ducts, whereas phosphorylated AKT was ubiquitous. We next observed a gradient of cell migration speeds from rear to front of elongating ducts, with the front characterized by both high pERK and the fastest cells. Furthermore, cells within elongating ducts oriented both their protrusions and their migration in the direction of tube elongation. By contrast, cells within the organoid body were isotropically protrusive. We next tested the requirement for proliferation and migration. Early inhibition of proliferation blocked the creation of migratory cells, whereas late inhibition of proliferation did not block continued duct elongation. By contrast, pharmacological inhibition of either MEK or Rac1 signaling acutely blocked both cell migration and duct elongation. Finally, conditional induction of MEK activity was sufficient to induce collective cell migration and ductal elongation. Our data suggest a model for ductal elongation in which RTK-dependent proliferation creates motile cells with high pERK, the collective migration of which acutely requires both MEK and Rac1 signaling.