cssi/SciSciGPT-SciSciNet huggingface dataset:
Towards an Optimal Noise Versus Resolution Trade-Off in Wind Scatterometry

A scatterometer is a radar that measures the normalized radar cross section sigma(sup 0) of the Earth's surface. Over the ocean this signal is related to the wind via the geophysical model function (GMF). The objective of wind scatterometry is to estimate the wind vector field from sigma(sup 0) measurements; however, there are many subtleties that complicate this problem-making it difficult to obtain a unique wind field estimate. Conventionally, wind estimation is split into two stages: a wind retrieval stage in which several ambiguous solutions are obtained, and an ambiguity removal stage in which ambiguities are chosen to produce an appropriate wind vector field estimate. The most common approach to wind field estimation is to grid the scatterometer swath into wind vector cells and estimate wind vector ambiguities independently for each cell. Then, field wise structure is imposed on the solution by an ambiguity selection routine. Although this approach is simple and practical, it neglects field wise structure in the retrieval step and does not account for the spatial correlation imposed by the sampling. This makes it difficult to develop a theoretically appropriate noise versus resolution trade-off using pointwise retrieval. Fieldwise structure may be imposed in the retrieval step using a model-based approach. However, this approach is generally only practical if a low order wind field model is applied, which may discard more information than is desired. Furthermore, model-based approaches do not account for the structure imposed by the sampling. A more general fieldwise approach is to estimate all the wind vectors for all the WVCs simultaneously from all the measurements. This approach can account for structure of the wind field as well as structure imposed by the sampling in the wind retrieval step. Williams and Long in 2010 developed a fieldwise retrieval method based on maximum a posteriori estimation (MAP). This MAP approach can be extended to perform a noise versus resolution trade-off, and deal with ambiguity selection. This paper extends the fieldwise MAP estimation approach and investigates both the noise versus resolution trade-off as well as ambiguity removal in the fieldwise wind retrieval step. The method is then applied to the Sea Winds scatterometer and the results are analyzed. This paper extends the fieldwise MAP estimation approach and investigates both the noise versus resolution trade-off as well as ambiguity removal in the fieldwise wind retrieval step. The method is then applied to the Sea Winds scatterometer and the results are analyzed.
Co-Design of Free-Space Metasurface Optical Neuromorphic Classifiers for High Performance

Classification of features in a scene typically requires conversion of the incoming photonic field into the electronic domain. Recently, an alternative approach has emerged whereby passive structured materials can perform classification tasks by directly using free-space propagation and diffraction of light. In this manuscript, we present a theoretical and computational study of such systems and establish the basic features that govern their performance. We show that system architecture, material structure, and input light field are intertwined and need to be co-designed to maximize classification accuracy. Our simulations show that a single layer metasurface can achieve classification accuracy better than conventional linear classifiers, with an order of magnitude fewer diffractive features than previously reported. For a wavelength {\lambda}, single layer metasurfaces of size with aperture density achieve ~96% testing accuracy on the MNIST dataset, for an optimized distance ~ to the output plane. This is enabled by an intrinsic nonlinearity in photodetection, despite the use of linear optical metamaterials. Furthermore, we find that once the system is optimized, the number of diffractive features is the main determinant of classification performance. The slow asymptotic scaling with the number of apertures suggests a reason why such systems may benefit from multiple layer designs. Finally, we show a trade-off between the number of apertures and fabrication noise.
Superatomic nature of metal encapsulated dodecahedrane: The case of M@C20H20 (M = Li, Na, Mg+)

The idea of designing unprecedented materials made of superatomic building blocks, motivated the present study on endohedral M@C20H20 (M = Li, Na, Mg+) species. Ground and excited electronic structures of M@C20H20 (M = Li, Na, Mg+) were analyzed by means of high-level quantum calculations. In their ground states, one electron occupies a defuse superatomic s-orbital that lies around the C20H20 cage. These entities populate higher angular momentum p-, d-, f-, g-superatomic orbitals in their low-lying electronic states. The proposed superatomic Aufbau shell model for Li@C20H20 and Na@C20H20 is 1s, 1p, 1d, 2s, 1f, 2p, 2d, 1g, 2f slightly different from that of Mg@C20H20+ which is 1s, 1p, 1d, 2s, 1f, 2p, 2d, 1g, 3s, 2f, 2g, 3p. These introduced superatomic orbital series resemble the Aufbau principle of solvated electron precursors.
Conservation laws in coupled cluster dynamics at finite temperature.

We extend the finite-temperature Keldysh non-equilibrium coupled cluster theory (Keldysh-CC) [A. F. White and G. K.-L. Chan, J. Chem. Theory Comput. 15, 6137–6253 (2019)] to include a time-dependent orbital basis. When chosen to minimize the action, such a basis restores local and global conservation laws (Ehrenfest’s theorem) for all one-particle properties while remaining energy conserving for time-independent Hamiltonians. We present the time-dependent Keldysh orbital-optimized coupled cluster doubles method in analogy with the formalism for zero-temperature dynamics, extended to finite temperatures through the time-dependent action on the Keldysh contour. To demonstrate the conservation property and understand the numerical performance of the method, we apply it to several problems of non-equilibrium finite-temperature dynamics: a 1D Hubbard model with a time-dependent Peierls phase, laser driving of molecular H2, driven dynamics in warm-dense silicon, and transport in the single impurity Anderson model.
Mechanism performance under strategy advice and sub-optimal play: A school choice experiment

Abstract We implement a laboratory experiment to study how strategy advice affects participant decisions in a school choice game. In the Deferred Acceptance (DA) mechanism, advice to choose the dominant strategy of truth-telling induces participants to do so. In the Immediate Acceptance (IA) mechanism, advice to implement one of two heuristic strategies induces participants to choose one of those strategies. We develop a new partially-ordered typology of DA strategies to study the sub-optimal strategies chosen by participants under advice versus no advice. Then, using the varying proportions of participants choosing sub-optimal strategies in our data, we perform exploratory analyses on mechanism performance. We find that DA outperforms IA in efficiency, stability, and proportion of participants assigned their most preferred school. These performance differences are larger under strategy advice. (school choice, experiment, strategy advice, mechanism design, sub-optimal play)
One world, two moneys

espanolLos politicos nacionales confrontados con una deuda soberana y una demanda decreciente de bonos soberanos futuros sin precendentes, pue-den emprender acciones de represion financiera en sus paises, emitiendo bonos soberanos conjuntos con otras naciones (“Dinero Politico”). El uso de Dinero Politico ayuda a ocultar a los acreedores el hecho de que las naciones estan endeudadas de forma insostenible. Simultaneamente, algunos bancos centrales han propuesto un proceso gradual mediante el cual las naciones transferirian su oro y su plata como “garantia” de sus deudas soberanas individuales y conjuntas a un banco central que actuaria inicialmente como el mayor agente de custodia del mundo. Este gran agente de custodia podria (1) acabar con la deuda individual y conjunta del pais y (2) eventualmente tomar posesion de facto del oro que ese pais haya depositado, de modo que pudiese emitir una moneda universal “ligada al oro”(“Dinero Oligarca”), que no es lo mismo que tener una moneda respaldada por oro. El Dinero Oligarca eventualmente podria reemplazar todo el Dinero Politico, y financieramente, las naciones no tendrian fronteras, perdiendo sus caracteristicas fiscales distintivas. Los resultados del Dinero Politico y del Dinero Oligarca seran la pobreza masiva y el dano ambiental. La unica manera de evitar estas consecuencias es mediante la cooperacion entre los politicos y los bancos centrales para limitar el gasto fiscal y volver a respaldar las monedas nacionales con las reservas de metales preciosos de cada pais. EnglishNational politicians, confronted with unprecedented sovereign debt and declining demand for future sovereign bonds, may engage in financial repression in their homelands, while issuing joint sovereign bonds with other nations (“Political Money”). These steps may obscure from pollyannaish credi-tors the fact that the nations are unsustainably indebted.Simultaneously, some central bankers have proposed a stepwise process by which nations would transfer their sovereign gold and silver as “collateral” for their individual and joint sovereign debts to a central banker-run repository that would initially act as the world’s biggest escrow agent. This supranational escrow agent/repository could (1) handle the retirement of most individual and joint sovereign debt and (2) eventually take de facto ownership of pooled sov-ereign gold, such that the repository could itself issue a universal “gold-linked” (which is not the same as gold-backed) fiat currency (“Oligarch Money”). Oli-garch Money eventually could replace all Political Money. Nations would become financially borderless, losing their distinct fiscal characters.The byproducts of Political and Oligarch moneys will be mass poverty and environmental damage. Only by cooperation between politicians and central bank-ers to limit sovereign fiscal spending and to re-tether national currencies to national stores of precious metals can these consequences be avoided
Generalized bijective maps between G-parking functions, spanning trees, and the Tutte polynomial

Abstract We introduce an object called a tree growing sequence (TGS) in an effort to generalize bijective correspondences between G -parking functions, spanning trees, and the set of monomials in the Tutte polynomial of a graph G . A tree growing sequence determines an algorithm which can be applied to a single function, or to the set P G , q of G -parking functions. When the latter is chosen, the algorithm uses splitting operations – inspired by the recursive definition of the Tutte polynomial – to iteratively break P G , q into disjoint subsets. This results in bijective maps τ and ρ from P G , q to the spanning trees of G and Tutte monomials, respectively. We compare the TGS algorithm to Dhar’s algorithm and the family described by Chebikin and Pylyavskyy in 2005. Finally, we compute a Tutte polynomial of a zonotopal tiling using analogous splitting operations.
Single-cycle all-fiber frequency comb

Single-cycle pulses with a deterministic carrier-envelope phase enable the study and control of light–matter interactions at the sub-cycle timescale, as well as the efficient generation of low-noise multi-octave frequency combs. However, current single-cycle light sources are difficult to implement and operate, hindering their application and accessibility in a wider range of research. In this paper, we present a single-cycle 100 MHz frequency comb in a compact, turnkey, and reliable all-silica-fiber format. This is achieved by amplifying 2 µm seed pulses in heavily doped Tm:fiber, followed by cascaded self-compression to yield 6.8 fs pulses with 215 kW peak power and 374 mW average power. The corresponding spectrum covers more than two octaves, from below 700 up to 3500 nm. Driven by this single-cycle pump, supercontinuum with 180 mW of integrated power and a smooth spectral amplitude between 2100 and 2700 nm is generated directly in silica fibers. To broaden applications, few-cycle pulses extending from 6 µm to beyond 22 µm with a long-term stable carrier-envelope phase are created using the intra-pulse difference frequency, and electro-optic sampling yields comb-tooth-resolved spectra. Our work demonstrates the first all-fiber configuration that generates single-cycle pulses and provides a practical source to study nonlinear optics on the same timescale.
Quadratic Residual Networks: A New Class of Neural Networks for Solving Forward and Inverse Problems in Physics Involving PDEs.

We propose quadratic residual networks (QRes) as a new type of parameter-efficient neural network architecture, by adding a quadratic residual term to the weighted sum of inputs before applying activation functions. With sufficiently high functional capacity (or expressive power), we show that it is especially powerful for solving forward and inverse physics problems involving partial differential equations (PDEs). Using tools from algebraic geometry, we theoretically demonstrate that, in contrast to plain neural networks, QRes shows better parameter efficiency in terms of network width and depth thanks to higher non-linearity in every neuron. Finally, we empirically show that QRes shows faster convergence speed in terms of number of training epochs especially in learning complex patterns.
Sublinear Regret with Barzilai-Borwein Step Sizes

This paper considers the online scenario using the Barzilai-Borwein Quasi-Newton Method. In an online optimization problem, an online agent uses a certain algorithm to decide on an objective at each time step after which a possible loss is encountered. Even though the online player will ideally try to make the best decisions possible at each time step, there is a notion of regret associated with the player’s decisions. This study examines the regret of an online player using optimization methods like the Quasi-Newton methods, due to their fast convergent properties. The Barzilai-Borwein (BB) gradient method is chosen in this paper over other Quasi-Newton methods such as the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm because of its less computational complexities. In addition, the BB gradient method is suitable for large-scale optimization problems including the online optimization scenario presented in this paper. To corroborate the effectiveness of the Barzilai-Borwein (BB) gradient algorithm, a greedy online gradient algorithm is used in this study based on the two BB step sizes. Through a rigorous regret analysis on the BB step sizes, it is established that the regret obtained from the BB algorithm is sublinear in time. Moreover, this paper shows that the average regret using the online BB algorithm approaches zero without assuming strong convexity on the cost function to be minimized.
Replay in Deep Learning: Current Approaches and Missing Biological Elements

Replay is the reactivation of one or more neural patterns that are similar to the activation patterns experienced during past waking experiences. Replay was first observed in biological neural networks during sleep, and it is now thought to play a critical role in memory formation, retrieval, and consolidation. Replay-like mechanisms have been incorporated in deep artificial neural networks that learn over time to avoid catastrophic forgetting of previous knowledge. Replay algorithms have been successfully used in a wide range of deep learning methods within supervised, unsupervised, and reinforcement learning paradigms. In this letter, we provide the first comprehensive comparison between replay in the mammalian brain and replay in artificial neural networks. We identify multiple aspects of biological replay that are missing in deep learning systems and hypothesize how they could be used to improve artificial neural networks.
AffectiveTDA: Using Topological Data Analysis to Improve Analysis and Explainability in Affective Computing

We present an approach utilizing Topological Data Analysis to study the structure of face poses used in affective computing, i.e., the process of recognizing human emotion. The approach uses a conditional comparison of different emotions, both respective and irrespective of time, with multiple topological distance metrics, dimension reduction techniques, and face subsections (e.g., eyes, nose, mouth, etc.). The results confirm that our topology-based approach captures known patterns, distinctions between emotions, and distinctions between individuals, which is an important step towards more robust and explainable emotion recognition by machines.
When Shall I Be Empathetic? The Utility of Empathetic Parameter Estimation in Multi-Agent Interactions

Human-robot interactions (HRI) can be modeled as differential games with incomplete information, where each agent holds private reward parameters. Due to the open challenge in finding perfect Bayesian equilibria of such games, existing studies often decouple the belief and physical dynamics by iterating between belief update and motion planning. Importantly, the robot’s reward parameters are often assumed to be known to the humans, in order to simplify the computation. We show in this paper that under this simplification, the robot performs non-empathetic belief update about the humans’ parameters, which causes high safety risks in uncontrolled intersection scenarios. In contrast, we propose a model for empathetic belief update, where the agent updates the joint probabilities of all agents’ parameter combinations. The update uses a neural network that approximates the Nash equilibrial action-values of agents. We compare empathetic and non-empathetic belief update methods on a two-vehicle uncontrolled intersection case with short reaction time. Results show that when both agents are unknowingly aggressive (or non-aggressive), empathy is necessary for avoiding collisions when agents have false believes about each others’ parameters. This paper demonstrates the importance of acknowledging the incomplete-information nature of HRI.
Equilibrium of an Arbitrary Bunch Train with Cavity Resonators and Short Range Wake: Enhanced Iterative Solution with Anderson Acceleration

This paper continues the work of two previous treatments of bunch lengthening by a passive harmonic cavity in an electron storage ring. Such cavities, intended to reduce the effect of Touschek scattering, are a feature of fourth generation synchrotron light sources. The charge densities in the equilibrium state are given by solutions of coupled Ha\"{\i}ssinski equations, which are nonlinear integral equations. If the only wake fields are from cavity resonators, the unknowns can be the Fourier transforms of bunch densities at the resonator frequencies. The solution scheme based on this choice of unknowns proved to be deficient at the design current when multiple resonators were included. Here we return to the conventional formulation of Ha\"{\i}ssinski equations in coordinate space, the unknowns being charge densities at mesh points on a fine grid. This system would be awkward to solve by the Newton method used previously, because the Jacobian matrix is very large. Here a new solution is described, which is both Jacobian-free and much simpler. It is based on an elementary fixed point iteration, accelerated by Anderson's method. The scheme is notably fast and robust, accommodating even the case of extreme overstretching at current far beyond the design value. The Anderson method is promising for many problems in accelerator theory and beyond, since it is quite simple and can be used to attack all kinds of nonlinear and linear integral and differential equations. Results are presented for ALS-U with updated design parameters. The model includes harmonic and main rf cavities, compensation of beam loading of the main cavity by adjustment of the generator voltage, and a realistic short range wake field (rather than the broadband resonator wake invoked previously).
SARS-CoV-2 infection in heart transplant recipients: a systematic literature review of clinical outcomes and immunosuppression strategies

The impact of SARS-CoV-2 infection on heart transplant recipients is unknown. Literature is limited to case reports and series. The purpose of this study is to identify the clinical features, outcomes, and immunosuppression strategies of heart transplant recipients with COVID-19 infection. A systematic review was conducted using the search term “Coronavirus” or COVID,” “SARS-CoV-2,” “cardiac transplantation,” and “heart transplant.” Case reports and retrospective studies were gathered by searching Medline/PubMed, Google Scholar, CINAHL, Cochrane CENTRAL, and Web of Science. Thirty-three articles were selected for review. We identified 74 cases of SARS-CoV-2 infection in heart transplant and heart-kidney transplant recipients. The mean age was 60.5 ± 15.8 years, and 82.4% were males with median time from transplant of 6.5 years. Commonest symptoms were fever, cough, and dyspnea, but new left ventricular (LV) dysfunction was rare. Leukocytosis, lymphopenia, elevated inflammatory markers, and bilateral ground-glass opacities were common. Mortality was high, with particularly poor survival in patients who required intensive care unit (ICU) admission and older patients. Immunosuppression involved discontinuation of antimetabolites and steroids. COVID-19 infection in heart transplant (HT) recipients presents similarly to the general population, but new onset of LV dysfunction is uncommon. Immunosuppression strategies include increase in corticosteroids and discontinuation of antimetabolites.
Elevating density functional theory to chemical accuracy for water simulations through a density-corrected many-body formalism.

Density functional theory (DFT) has been extensively used to model the properties of water. Albeit maintaining a good balance between accuracy and efficiency, no density functional has so far achieved the degree of accuracy necessary to correctly predict the properties of water across the entire phase diagram. Here, we present density-corrected SCAN (DC-SCAN) calculations for water which, minimizing density-driven errors, elevate the accuracy of the SCAN functional to that of “gold standard” coupled-cluster theory. Building upon the accuracy of DC-SCAN within a many-body formalism, we introduce a data-driven many-body potential energy function, MB-SCAN(DC), that quantitatively reproduces coupled cluster reference values for interaction, binding, and individual many-body energies of water clusters. Importantly, molecular dynamics simulations carried out with MB-SCAN(DC) also reproduce the properties of liquid water, which thus demonstrates that MB-SCAN(DC) is effectively the first DFT-based model that correctly describes water from the gas to the liquid phase. No existing density functional correctly describes the properties of water across the entire phase diagram. The authors report a data-driven many-body potential energy function based on density-corrected SCAN functional that quantitatively reproduces the energetics of gas-phase water clusters, and correctly predicts the properties of liquid water.
Jerk-Minimized CILQR for Human-Like Driving on Two-Lane Roadway

This work proposes a novel framework for motion planning using trajectory optimization for autonomous driving. First, a two-phase behavioral policy maker (BPM) is proposed as a high-level decision maker to mimic human-like driving style by avoiding unnecessary tasks and early lane changes. Second, a comprehensive study on iterative adaptive weight tuning functions has been done to limit manual weight tuning in the Constrained Iterative Linear Quadratic Regulator (CILQR) motion planner. Third, a jerk-minimized CILQR is presented to ensure the comfort and safety of passengers by generating smooth trajectories. The simulation results show efficiency, safety, and comfort of generated trajectories.
Modeling the public health impact of e-cigarettes on adolescents and adults

Since the introduction of electronic cigarettes to the U.S. market in 2007, vaping prevalence has surged in both adult and adolescent populations. E-cigarettes are advertised as a safer alternative to traditional cigarettes and as a method of smoking cessation, but the U.S. government and health professionals are concerned that e-cigarettes attract young non-smokers. Here, we develop and analyze a dynamical systems model of competition between traditional and electronic cigarettes for users. With this model, we predict the change in smoking prevalence due to the introduction of vaping, and we determine the conditions under which e-cigarettes present a net public health benefit or harm to society.
Patch Attack Invariance: How Sensitive Are Patch Attacks to 3D Pose?

Perturbation-based attacks, while not physically realizable, have been the main emphasis of adversarial machine learning (ML) research. Patch-based attacks by contrast are physically realizable, yet most work has focused on 2D domain with recent forays into 3D. Characterizing the robustness properties of patch attacks and their invariance to 3D pose is important, yet not fully elucidated, and is the focus of this paper. To this end, several contributions are made here: A) we develop a new metric called mean Attack Success over Transformations (mAST) to evaluate patch attack robustness and invariance; and B), we systematically assess robustness of patch attacks to 3D position and orientation for various conditions; in particular, we conduct a sensitivity analysis which provides important qualitative insights into attack effectiveness as a function of the 3D pose of a patch relative to the camera (rotation, translation) and sets forth some properties for patch attack 3D invariance; and C), we draw novel qualitative conclusions including: 1) we demonstrate that for some 3D transformations, namely rotation and loom, increasing the training distribution support yields an increase in patch success over the full range at test time. 2) We provide new insights into the existence of a fundamental cutoff limit in patch attack effectiveness that depends on the extent of out-of-plane rotation angles. These findings should collectively guide future design of 3D patch attacks and defenses.
Auguste Comte: The Vicissitudes of Positivism during the Early Empire

A single dissidence suffices for the mind to render sterile the greatest conformity of opinions, whereas the heart easily overcomes serious divergences because of the existence of a similar sentiment pushing toward a common goal. Comte, “Deuxieme Circulaire annuelle,” March 24, 1851 NEW DISCIPLES DURING THE EMPIRE Under the Empire, the Positivist Society suffered from defections and slow growth. Meetings were dull because only Comte spoke for fear of being contradicted. Robinet and Magnin, who were among Comte's most loyal disciples, were adversaries of the Empire and tried to be diplomatic. No one felt free to discuss anything. Dr. Rene Cousin and Lefort were the only new members in 1852. There were two new members in 1853, one in 1854, three in 1855, and one in 1856. The new members under the Empire came from all walks of life, from professions such as law and medicine to the artisanal workforce. But it would be a mistake to judge the success of positivism solely by the membership of the Positivist Society. Positivism continued to attract numerous sympathizers with various degrees of adherence to all its principles. Indeed, the number of contributors to the Positivist Subsidy began to rise. Its subscribers included some workers, who after laboring for fifteen to sixteen hours a day, had barely enough money to feed their own families. A few women also gave to the Subsidy.
The Independence of Independents: Influences on Commercial Driver Intentions to Commit Unsafe Acts

Modern American folklore describes independent owner-operator truckers as the last cowboys or frontiersman. If accurate, the individualistic nature of the independent trucker would mitigate the effectiveness of "corporate culture" in modifying behavioral intentions. The modern independent owner-operator exists in a unique environment characterized by high regulation and low supervision, with highly undesirable consequences for bad decisions. This study used owner-operators' perceptions of carrier safety climate and the Theory of Planned Behavior (Ajzen 1991) to understand drivers; intentions to engage in potentially unsafe driving behavior. The relationships were tested with data from nearly 300 owner-operators who conduct national, regional, and local driving operations. Results supported the individualistic nature of owner-operators. Results also indicated that a carrier's use of supportive (versus directive) safety practices, combined with drivers' attitudes towards and perceived behavioral control of unsafe driving, significantly and directly influenced drivers' intentions to commit unsafe driving actions. These key findings inform carriers about adopting more resourceful safety training and awareness programs that provide drivers the necessary tools and skills to drive safely and avoid potential danger outside their control.
Passive core-shell-based metamaterials to control infrared emissions

The need to control thermal emissions when devices, such as infrared (IR) sensors, are in close proximity to a heat source, has a number of defense and security applications. By tuning the geometry and material properties of core-shell particles, we will illustrate how they can be designed to control IR emissions, i.e., electromagnetic waves in the 8–12 µm range. In particular, we will illustrate the realization of Huygens' source types of nano- and micron-sized particles that have low backscattering and large forward scattering. Their integration into a substrate near to its interface leads to additional directionality control that has been investigated for practical applications.
Size Effect of the Adhesive Bonding Strengths of Metal/Polymer Similar and Dissimilar Material Joints

The relationship between the adhesive bonding strengths and the bonding areas (sizes) is important for material and structural designs, because adhesive bonding is widely used not only in small scale electronic devices, but also in large-scale composite–metal joints of modern aircraft/ship structures. Therefore, a systematic experimental investigation on adhesive bonding strengths of polymer/polymer, metal/metal, and polymer/metal joints was conducted. Results show that the size effect of the bonding strengths is small for the current bonding areas (from 30 to 300 mm2), which are widely employed in most of the test standards for engineering designs.
Diagnostic methods for intracellular pathogens

Diagnosis of infection with Chlamydia pneumoniae is difficult and the optimal diagnostic procedure has yet to be established. C. pneumoniae is more difficult to isolate in tissue culture than C. trachomatis. Attention must be paid to the site from which the specimen is taken, and all specimens should be processed within 24 h or stored at 4 °C. Serologic diagnosis largely depends on microimmunofluorescence testing which, despite proposed criteria, still has a large subjective component. Serology has limitations in terms of both sensitivity and specificity and antibodies may be difficult to detect in individuals with positive C. pneumoniae cultures. Non-culture methods include enzyme immunoassays, fluorescent-antibody techniques and DNA probes. The most promising appears to be PCR. Co-infection of C. pneumoniae and other respiratory organisms seem to be common.
Student Preference On Exam Frequency: A Short Study

Eexaminations are used by most professors as an important assessment tool to aid in determining the level of student subject matter comprehension. We also use the feedback from examinations as an indicator of the appropriateness and effectiveness of the teaching methodologies we are utilizing in the classroom. This paper reports the number and types of exams/quizzes preferred by the students.
Super-resolution for flash LADAR data

Flash laser detection and ranging (LADAR) systems are increasingly used in robotics applications for autonomous navigation and obstacle avoidance. Their compact size, high frame rate, wide field of view, and low cost are key advantages over traditional scanning LADAR devices. However, these benefits are achieved at the cost of spatial resolution. Super-resolution enhancement can be applied to improve the resolution of flash LADAR devices, making them ideal for small robotics applications. Previous work by Rosenbush et al. applied the super-resolution algorithm of Vandewalle et al. to flash LADAR data, and observed quantitative improvement in image quality in terms of number of edges detected. This study uses the super-resolution algorithm of Young et al. to enhance the resolution of range data acquired with a SwissRanger SR-3000 flash LADAR camera. To improve the accuracy of sub-pixel shift estimation, a wavelet preprocessing stage was developed and applied to flash LADAR imagery. The authors used the triangle orientation discrimination (TOD) methodology for a subjective evaluation of the performance improvement (measured in terms of probability of target discrimination and subject response times) achieved with super-resolution. Super-resolution of flash LADAR imagery resulted in superior probabilities of target discrimination at the all investigated ranges while reducing subject response times.
Classroom Dynamic Assessment of Reading Comprehension with Second Language Learners

This study examines the design and implementation of a dynamic reading comprehension task (D-RCT) for classroom use with second language learners. A paper and pencil D-RCT was designed that could be (1) utilized on a regular basis, (2) adapted to any content, and (3) easily implemented in classrooms where access to technology is limited. The teacher in the present work utilized pre-scripted mediation prompts during the D-RCT that were assigned a numerical value to calculate four scores for each individual student: an actual score, a mediated score, a learning potential score, and a mediation value score. The present study describes the assessment design and analyzes scoring procedures to determine their potential for classroom application. The authors conclude that D-RCTs should be used as a learning tool in second language classrooms and suggest recommendations for scoring procedures.
Development of an Automated Process for the Creation of a Basic Skirt Block Pattern from 3D Body Scan Data

Creating custom clothing manually is a labor-intensive process. 7hree-dimensional (3D) body scanning technology can provide the means to automatically create custom-fitted patterns, but methods are...
The Relationships Among Self-Blame, Psychological Distress, and Sexual Victimization

The primary purpose of this investigation is to assess the factor structure of survivors' attributions for previously experienced sexual assaults. Two hundred twenty-four female survivors of sexual assault responded to measures assessing attributions for past assaults, perceived avoidability of future assaults, frequency of past victimizations, and psychological distress. Factor analysis of the attributions measure suggested five underlying factors: perpetrator blame, characterological self-blame, situational factors and/or chance blame, behavioral self-blame, and societal blame. Results indicated that characterological self-blame, but not behavioral self-blame, was associated with negative outcomes, including increased psychological distress and increased frequency of past victimization. Although behavioral self-blame was associated with perceived avoidability of future assaults, it was not associated with lower psychological distress or reduced frequency of past victimizations.
Beware of proteins in DMSO

The effect on the secondary structure of representative alpha-helical, beta-sheet and disordered proteins by varying concentrations of dimethyl sulphoxide (DMSO) in 2H2O has been investigated by Fourier transform infrared spectroscopy. Significant perturbations of protein secondary structure are induced by DMSO and DMSO/2H2O mixtures. For highly structured proteins, such as myoglobin and concanavalin A, the infrared spectra point to a progressive destabilisation of the secondary structure until at moderate DMSO concentrations (around 0.33 mol fraction) intermolecular beta-sheet formation and aggregation are induced, as indicated by the appearance of a strong band at 1621 cm-1. This is a direct consequence of the disruption of intramolecular peptide group interactions by DMSO (partial unfolding). At higher DMSO concentrations (above 0.75 mol fraction), such aggregates are dissociated by disruption of the intermolecular C = O...2H-N deuterium bonds. The presence of a single amide I band at 1662 cm-1 corresponding to free amide C = O groups indicates that at high concentrations and in pure DMSO the proteins are completely unfolded, lacking any secondary structure. While low concentrations of DMSO showed no detectable effect upon the gross secondary structure of myoglobin and concanavalin A, the thermal stability of both proteins was markedly reduced. In alpha-casein, a highly unstructured protein, the situation is one of direct competition. The amide I maximum in 2H2O, at 1645 cm-1, is typical of unordered proteins with C = O groups deuterium-bonded predominantly to 2H2O. Addition of DMSO disrupts such interactions by competing with the peptide C = O group for the deuterium bond donor capacity of the 2H2O, and so progressively increases the amide I maximum until it stabilizes at 1663 cm-1, a position indicative of free C = O groups.
STAT6 is amplified in a subset of dedifferentiated liposarcoma

A recurrent intrachromosomal rearrangement on chromosome 12q in solitary fibrous tumor leads to the formation of a NAB2-STAT6 fusion oncogene. As a result, nuclear expression of the cytoplasmic transcription factor STAT6 is found in solitary fibrous tumor and serves as a useful diagnostic marker. STAT6 is located in 12q13, a region containing well-characterized oncogenes that are commonly amplified in dedifferentiated liposarcoma; we have previously reported that STAT6 is expressed in a subset of dedifferentiated liposarcoma. The aim of this study was to determine the frequency of STAT6 expression in dedifferentiated liposarcoma and the underlying genetic mechanism. STAT6 protein expression was analyzed by immunohistochemistry in a well-characterized series of 35 previously unpublished cases of dedifferentiated liposarcoma, all with nuclear MDM2 and/or CDK4 expression by immunohistochemistry and/or cytogenetic features of dedifferentiated liposarcoma. FISH for STAT6 was performed in all cases with STAT6 expression, and a subset of control cases without STAT6 expression. In total 4/35 cases (11%) showed STAT6 expression (three with multifocal staining of moderate to strong intensity and one with weak focal staining). FISH demonstrated amplification of STAT6 in all cases positive for STAT6 by immunohistochemistry; in contrast, FISH performed on four STAT6-negative dedifferentiated liposarcomas demonstrated no STAT6 amplification (P=0.0286). Of the four STAT6 amplified cases, three patients were male and one was female, ranging in age from 51 to 76 years. Tumors were located in the mediastinum (n=2), paratesticular soft tissue (n=1), and perirenal soft tissue (n=1). Three patients received pre-operative chemotherapy +/- radiation therapy. In conclusion, STAT6 is amplified in a subset of dedifferentiated liposarcoma, resulting in STAT6 protein expression that can be detected by immunohistochemistry and may be a potential pitfall in the differential diagnosis of dedifferentiated liposarcoma and solitary fibrous tumor. These findings suggest a role for STAT6-mediated transcriptional activity in some cases of dedifferentiated liposarcoma and highlight the genomic complexity and heterogeneity of dedifferentiated liposarcoma.
Instability of repeated dinucleotides in bacteriophage T7 genomes

Abstract The ligase gene of bacteriophage T7 was interrupted with an insert of synthetic DNA that included a series of dinucleotide repeats which altered the reading frame of the gene and prevented the phage from growing on a host deficient in Escherichia coli ligase. The insert was designed so that gain of an additional copy of the repeat would restore the reading frame and produce ligase positive T7. It was found that a pair of nucleotides was gained at a frequency of 1.4 × 10 −3 and a dinucleotide was lost from this sequence at a frequency of 1 × 10 −4 . The same measurements were made using T7 with a DNA polymerase without the 3′ → 5′ exonuclease function. This mutant DNA polymerase lacks proofreading edit function and is more processive than its wild-type counterpart. Phage without the edit function gained or lost a dinucleotide repeat significantly more frequently than did wild-type T7. Thus, the frequency of two base frameshifting is very high during DNA replication. Proofreading activity attenuates the frequency of two base frameshifts. Inactivation of the 3′ → 5′ exonuclease of T7 DNA polymerase had essentially no effect on the frequency of deletion of one member of a pair of 10 bp tandem repeats.
"Taita Chimborazo and Mama Tungurahua": A Quichua Song, a Fieldwork Story

When a friend in Chimborazo Province, central Ecuador, took me to his home village in 1995, he introduced me there as the gringo who sang the "Taita Chimborazo, Mama Tungurahua," a song broadcast from time to time on the morning Quichua radio program. The song is built on the story of "Amo Badillo," a landowner who died in the middle of this century. After his death Amo Badillo is supposed to have gone to Mt. Tungurahua—locally identified with purgatory or hell—to suffer there for his cruel treatment of the indigenous laborers on his estate. In 1991, when I was living in the house of Aurelio S., a farmer, village catechist, parish political leader, and occasional songwriter, I suggested that this story would make a good basis for a song for an upcoming music competition. Taita Aurelio quickly composed the song, framing the local story of Amo Badillo within more widespread oral traditions concerning Mt. Chimborazo and Mt. Tungurahua and making the story speak to contemporary ethnic politics. When the village music group Shepherds of Caparina Bajo presented the song at a Quichua music festival sponsored and taped by a Riobamba radio station, Taita Aurelio's words won us second prize. This essay discusses what the song—its creation, performance, and reception —can tell us about both the nature of fieldwork and contemporary indigenous identity and politics in Ecuador.
Recombinant human erythropoietin in cancer-related anemia: an evidence-based review

Anemia is a common complication of cancer or anticancer therapy, with a significant negative impact on the functional status of patients and their quality of life (QOL). Recombinant human erythropoietin (EPO) was developed in the 1980's and was initially developed for the treatment of anemia associated with chronic renal failure. Subsequently, randomized, placebo-controlled clinical trials in the oncology setting were performed in the early 1990's. These studies demonstrated in cancer patients that EPO could increase the levels of hemoglobin (Hb), decrease the need for red blood cell transfusions, and also suggested that these outcomes were associated with improved QOL metrics as reported by the patients themselves. Based on the results of these studies, EPO was granted regulatory approval to be used for the treatment of anemia in patients with non-myeloid malignancies where anemia was due to the effect of concomitantly administered chemotherapy. To further expand the findings of the registration studies, and to develop more complete QOL data, three similarly designed open-label community-based studies were performed, enrolling a total of approximately 7000 patients. These studies consistently demonstrated in the supportive care of cancer patients receiving chemotherapy that the use of EPO could induce increases in the levels of Hb and that these correlated with patient-reported improvements in QOL metrics. The correlation between an improvement in Hb and QOL has also been confirmed in a larger randomized, placebo-controlled trial. Careful analyses of data from this study also helped support earlier findings that EPO could be effective for patients with varying degrees of anemia, and that increasing and maintaining Hb levels close to the physiologically normal levels resulted in the optimal improvements in QOL. While further investigations of EPO as a mechanism to improve the antineoplastic efficacy of chemoradiotherapy have not yet been positive, the overall experience with this agent remains very favorable after extensive studies and long-term clinical use in oncology.
The oblique rectus abdominal myocutaneous flap for complex pelvic wound reconstruction.

Purpose The oblique rectus abdominal myocutaneous flap is a seldom used flap design based on perforating vessels exiting the rectus near the umbilicus. Compared to other flaps, the oblique rectus abdominal myocutaneous flap provides increased soft tissue to fill pelvic dead space, with the further advantage of intact skin to close perineal defects. Here we detail the oblique rectus abdominal myocutaneous flap in achieving closure of complex perineal wounds.
A qualitative GIS approach to mapping urban neighborhoods with children to promote physical activity and child-friendly community planning

As the obesity epidemic in children increases, it is important to consider the role of neighborhoods in supporting children's physical activity and healthy development, especially in low-income communities where obesity levels among children are higher than for their middle-income counterparts. I present a participatory and qualitative GIS approach to mapping children's own perceptions and use of their neighborhood for physical activity with ten and eleven year-olds growing up in a diverse low-income community in Denver, CO. Girls walk shorter distances to and use different types of community spaces for play and recreation from boys, some of which is explained by the differing environmental-socialization approaches employed by parents and carers. Children's perceptions of risk align spatially with features of the built environment, but do not correlate with reported crime. Results illustrate the utility of qualitative spatial analysis to understand relationships between children's perception, the built en...
Cement analysis using d + D neutrons

Abstract In the cement industry, the primary concern is quality control. The earlier the cement industry can institute quality control upon their product, the more significant their savings in labor, energy and material. We are developing a prototype cement analyzer using pulsed neutrons from a d–D electronic neutron generator with the goal of ensuring quality control of cement in an on-line manner. By utilizing a low intensity d–D neutron source and a specially-designed moderator assembly, we are able to produce one of the safest neutron-based systems in the market. Also, this design includes some exciting new methods of data acquisition which may substantially reduce the final installation costs. In our proof-of-principle measurements, we were able to measure the primary components of cement (Al, Si, Ca and Fe) to limits required for the raw materials, the derived mixes and the clinkers utilizing this neutron generator.