cssi/SciSciGPT-SciSciNet huggingface dataset:
Towards more reasonable identifications of the symmetries in noisy digital images from periodic and aperiodic crystals

A geometric form of information theory allows for reasonable, i.e. probabilistic, evidence-ranking based, and generalized noise-level dependent, classifications of the crystallographic and quasicrystallographic symmetries in noisy digital images. Such classifications are based solely on the image pixel intensity values, justifiable assumptions about the aggregate distribution of generalized noise in the images, asymptotic extrapolations to zero-noise images, and rational symmetry model selections with maximized predictive accuracy in the presence of both symmetry-inclusion relations and pseudo-symmetries. Preferring a well developed geometric form of information theory over a theoretically possible geometric-Bayesian approach for these classifications is the only subjective choice made. Using digital data planes and assuming approximately Gaussian distributed generalized noise, reasonable crystallographic and quasicrystallographic symmetry classifications can be made for noisy images from both scanning probe and transmission electron microscopes. A binary type classification of structurally very similar materials into either a quasicrystal or one of its rational/crystalline approximants based on the approximate point symmetries in their noisy digital images is proposed here for the first time.
Post Quantum Secure Command and Control of Mobile Agents Inserting Quantum-Resistant Encryption Schemes in the Secure Robot Operating System

The secure command and control (C&C) of mobile agents arises in various settings including unmanned aerial vehicles, single pilot operations in commercial settings, and mobile robots to name a few. As more and more of these applications get integrated into aerospace and defense use cases, the security of the communication channel between the ground station and the mobile agent is of increasing importance. The development of quantum computing devices poses a unique threat to secure communications due to the vulnerability of asymmetric ciphers to Shor's algorithm. Given the active development of new quantum resistant encryption techniques, we report the first integration of post-quantum secure encryption schemes with the robot operating system (ROS) and C&C of mobile agents, in general. We integrate these schemes in the application and network layers, and study the performance of these methods by comparing them to present day security schemes such as the widely used RSA algorithm.
Low-Shot Validation: Active Importance Sampling for Estimating Classifier Performance on Rare Categories

For machine learning models trained with limited labeled training data, validation stands to become the main bottleneck to reducing overall annotation costs. We propose a statistical validation algorithm that accurately estimates the F-score of binary classifiers for rare categories, where finding relevant examples to evaluate on is particularly challenging. Our key insight is that simultaneous calibration and importance sampling enables accurate estimates even in the low-sample regime (< 300 samples). Critically, we also derive an accurate single-trial estimator of the variance of our method and demonstrate that this estimator is empirically accurate at low sample counts, enabling a practitioner to know how well they can trust a given low-sample estimate. When validating state-of-the-art semi-supervised models on ImageNet and iNaturalist2017, our method achieves the same estimates of model performance with up to 10x fewer labels than competing approaches. In particular, we can estimate model F1 scores with a variance of 0.005 using as few as 100 labels.
Improved Gamma-Ray Point Source Quantification in Three Dimensions by Modeling Attenuation in the Scene

Using a series of detector measurements taken at different locations to localize a source of radiation is a well-studied problem. The source of radiation is sometimes constrained to a single point-like source, in which case the location of the point source can be found using techniques such as maximum likelihood. Recent advancements have shown the ability to locate point sources in 2-D and even 3-D but few have studied the effect of intervening material on the problem. In this work, we examine gamma-ray data taken from a freely moving system and develop voxelized 3-D models of the scene using data from its onboard light detection and ranging (LiDAR) unit. Ray casting is used to compute the distance each gamma ray travels through the scene material, which is then used to calculate attenuation assuming a single attenuation coefficient for solids within the geometry. Parameter estimation using maximum likelihood is performed to simultaneously find the attenuation coefficient, source activity, and source position that best match the data. Using a simulation, we validate the ability of this method to reconstruct the true location and activity of a source, along with the true attenuation coefficient of the structure it is inside, and then we apply the method to measured data with sources and find good agreement.
Learning Multi-Arm Manipulation Through Collaborative Teleoperation

Imitation Learning (IL) is a powerful paradigm to teach robots to perform manipulation tasks by allowing them to learn from human demonstrations collected via teleoperation, but has mostly been limited to single-arm manipulation. However, many real-world tasks require multiple arms, such as lifting a heavy object or assembling a desk. Unfortunately, applying IL to multi-arm manipulation tasks has been challenging –asking a human to control more than one robotic arm can impose significant cognitive burden and is often only possible for a maximum of two robot arms. To address these challenges, we present MULTI-ARM ROBOTURK (MART), a multi-user data collection platform that allows multiple remote users to simultaneously teleoperate a set of robotic arms and collect demonstrations for multi-arm tasks. Using MART, we collected demonstrations for five novel two and three-arm tasks from several geographically separated users. From our data we arrived at a critical insight: most multi-arm tasks do not require global coordination throughout its full duration, but only during specific moments. We show that learning from such data consequently presents challenges for centralized agents that directly attempt to model all robot actions simultaneously, and perform a comprehensive study of different policy architectures with varying levels of centralization on our tasks. Finally, we propose and evaluate a base-residual policy framework that allows trained policies to better adapt to the mixed coordination setting common in multi-arm manipulation, and show that a centralized policy augmented with a decentralized residual model outperforms all other models on our set of benchmark tasks. Additional results and videos at https://roboturk.stanford.edu/multiarm
Empirical Models for the Shielding and Reflection of Jet Mixing Noise by a Surface

Empirical models for the shielding and refection of jet mixing noise by a nearby surface are described and the resulting models evaluated. The flow variables are used to non-dimensionalize the surface position variables, reducing the variable space and producing models that are linear function of non-dimensional surface position and logarithmic in Strouhal frequency. A separate set of coefficients are determined at each observer angle in the dataset and linear interpolation is used to for the intermediate observer angles. The shielding and rejection models are then combined with existing empirical models for the jet mixing and jet-surface interaction noise sources to produce predicted spectra for a jet operating near a surface. These predictions are then evaluated against experimental data.
Predicting Lane Change Decision Making with Compact Support

In the foreseeable future, autonomous vehicles will have to drive alongside human drivers. In the absence of vehicle-to-vehicle communication, they will have to be able to predict the other road users' intentions. Moreover, they will also need to behave like a typical human driver so that other road users can infer their actions. It is critical to be able to learn a human driver's mental model and integrate it into the Planning & Control algorithm. In this paper, we present a robust method to predict lane changes as cooperative or adversarial. For that, we first introduce a method to extract and annotate lane changes as cooperative and adversarial based on the entire lane change trajectory. We then propose to train a specially designed neural network to predict the lane change label before the lane change has occurred and quantify the prediction uncertainty. The model will make lane change decisions following human drivers' driving habits and preferences, i.e., it will only change lanes when the surrounding traffic is considered to be appropriate for the majority of human drivers. It will also recognize unseen novel samples and output low prediction confidence correspondingly to alert the driver to take control in such cases. We published the lane change dataset and codes at https://github.com/huanghua1668/1c_csnn.
SAT: Improving Adversarial Training via Curriculum-Based Loss Smoothing

Adversarial training (AT) has become a popular choice for training robust networks. However, it tends to sacrifice clean accuracy heavily in favor of robustness and suffers from a large generalization error. To address these concerns, we propose Smooth Adversarial Training (SAT), guided by our analysis on the eigenspectrum of the loss Hessian. We find that curriculum learning, a scheme that emphasizes on starting "easy'' and gradually ramping up on the "difficulty'' of training, smooths the adversarial loss landscape for a suitably chosen difficulty metric. We present a general formulation for curriculum learning in the adversarial setting and propose two difficulty metrics based on the maximal Hessian eigenvalue (H-SAT) and the softmax probability (P-SA). We demonstrate that SAT stabilizes network training even for a large perturbation norm and allows the network to operate at a better clean accuracy versus robustness trade-off curve compared to AT. This leads to a significant improvement in both clean accuracy and robustness compared to AT, TRADES, and other baselines. To highlight a few results, our best model improves normal and robust accuracy by 6% and 1% on CIFAR-100 compared to AT, respectively. On Imagenette, a ten-class subset of ImageNet, our model outperforms AT by 23% and 3% on normal and robust accuracy respectively.
Themis: Ambiguity-Aware Network Intrusion Detection based on Symbolic Model Comparison

Network intrusion detection systems (NIDS) can be evaded by carefully crafted packets that exploit implementation-level discrepancies between how they are processed on the NIDS and at the endhosts. These discrepancies arise due to the plethora of endhost implementations and evolutions thereof. It is prohibitive to proactively employ a large set of implementations at the NIDS and check incoming packets against all of those. Hence, NIDS typically choose simplified implementations that attempt to approximate and generalize across the different endhost implementations. Unfortunately, this solution is fundamentally flawed since such approximations are bound to have discrepancies with some endhost implementations. In this paper, we develop a lightweight system Themis, which empowers the NIDS in identifying these discrepancies and reactively forking its connection states when any packets with "ambiguities" are encountered. Specifically, Themis incorporates an offline phase in which it extracts models from various popular implementations using symbolic execution. During runtime, it maintains a nondeterministic finite automaton to keep track of the states for each possible implementation. Our extensive evaluations show that Themis is extremely effective and can detect all evasion attacks known to date, while consuming extremely low overhead. En route, we also discovered multiple previously unknown discrepancies that can be exploited to bypass current NIDS.
MAP Propagation Algorithm: Faster Learning with a Team of Reinforcement Learning Agents

Nearly all state-of-the-art deep learning algorithms rely on error backpropagation, which is generally regarded as biologically implausible. An alternative way of training an artificial neural network is through treating each unit in the network as a reinforcement learning agent, and thus the network is considered as a team of agents. As such, all units can be trained by REINFORCE, a local learning rule modulated by a global signal that is more consistent with biologically observed forms of synaptic plasticity. Although this learning rule follows the gradient of return in expectation, it suffers from high variance and thus the low speed of learning, rendering it impractical to train deep networks. We therefore propose a novel algorithm called MAP propagation to reduce this variance significantly while retaining the local property of the learning rule. Experiments demonstrated that MAP propagation could solve common reinforcement learning tasks at a similar speed to backpropagation when applied to an actor-critic network. Our work thus allows for the broader application of the teams of agents in deep reinforcement learning.
Mathematical model of subthalamic nucleus neuron: Characteristic activity patterns and bifurcation analysis

The subthalamic nucleus (STN) has an important role in the pathophysiology of the basal ganglia in Parkinson's disease. The ability of STN cells to generate bursting rhythms under either transient or sustained hyperpolarization may underlie the excessively synchronous beta rhythms observed in Parkinson's disease. In this study, we developed a conductance-based single compartment model of an STN neuron, which is able to generate characteristic activity patterns observed in experiments including hyperpolarization-induced bursts and post-inhibitory rebound bursts. This study focused on the role of three currents in rhythm generation: T-type calcium (CaT) current, L-type calcium (CaL) current, and hyperpolarization-activated cyclic nucleotide-gated (HCN) current. To investigate the effects of these currents in rhythm generation, we performed a bifurcation analysis using slow variables in these currents. Bifurcation analysis showed that the HCN current promotes single-spike activity patterns rather than bursting in agreement with experimental results. It also showed that the CaT current is necessary for characteristic bursting activity patterns. In particular, the CaT current enables STN neurons to generate these activity patterns under hyperpolarizing stimuli. The CaL current enriches and reinforces these characteristic activity patterns. In hyperpolarization-induced bursts or post-inhibitory rebound bursts, the CaL current allows STN neurons to generate long bursting patterns. Thus, the bifurcation analysis explained the synergistic interaction of the CaT and CaL currents, which enables STN neurons to respond to hyperpolarizing stimuli in a salient way. The results of this study implicate the importance of CaT and CaL currents in the pathophysiology of the basal ganglia in Parkinson's disease.
Flexible plasma multi-jet source operated in radial discharge configuration

Following up on a recent study describing a flexible plasma source operated in planar geometry, the performance of a cold atmospheric plasma jet (CAPJ) matrix emanating radially from a soft cylindrical surface in the open air is presented. The plasma device, which has a set of small outlets produced in its side surface, has a length of 12 cm and an outer diameter of 5.4 cm. The dielectric barrier discharge (DBD) sustaining the plasma jets is generated in helium flowing between two coaxial electrodes, which are separated by both an insulating tape and a cylindrical wall made of polymer foam. Two operation modes are considered: four equidistant CAPJs at the same axial position (round brush mode) and three aligned CAPJs at constant azimuthal angle (comb mode). All discharges, excited by 15 kHz-AC voltages at 3.8 kV in amplitude, have resulted in uniform lengths and intensities of the jets. Consumed discharge powers of between 0.1 and 1.5 W have been estimated from current–voltage measurements. Optical emission spectroscopy has shown the preponderance of hydroxyl groups, nitrogen molecules, and helium atoms in the active DBD region and the jet afterglow zone. This new design of CAPJ anticipates promising applications for treating the inner surface of hollow and delicate components for activation or healing purposes.
Do gestures really facilitate speech production

Why do people gesture when they speak? According to one influential proposal, the Lexical Retrieval Hypothesis (LRH), gestures serve a cognitive function in speakers' minds by helping them find the right spatial words. Do gestures also help speakers find the right words when they talk about abstract concepts that are spatialized metaphorically? If so, then preventing people from gesturing should increase the rate of disfluencies during speech about both literal and metaphorical space. Here, we sought to conceptually replicate the finding that preventing speakers from gesturing increases disfluencies in speech with literal spatial content (e.g., the rocket went up), which has been interpreted as evidence for the LRH, and to extend this pattern to speech with metaphorical spatial content (e.g., my grades went up). Across three measures of speech disfluency (disfluency rate, speech rate, and rate of nonjuncture filled pauses), we found no difference in disfluency between speakers who were allowed to gesture freely and speakers who were not allowed to gesture, for any category of speech (literal spatial content, metaphorical spatial content, and no spatial content). This large dataset (7,969 phrases containing 2,075 disfluencies) provided no support for the idea that gestures help speakers find the right words, even for speech with literal spatial content. Upon reexamining studies cited as evidence for the LRH and related proposals over the past 5 decades, we conclude that there is, in fact, no reliable evidence that preventing gestures impairs speaking. Together, these findings challenge long-held beliefs about why people gesture when they speak. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Spectral invariance hypothesis study of polarized reflectance with Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI)

Many models used to represent the boundary condition for the separation of atmospheric scattering from the surface reflectance in polarized remote sensing measurements assume that the polarized surface reflectance is spectrally neutral. The Spectral Invariance Hypothesis asserts that the magnitude and shape of the polarized bidirectional reflectance factor (pBRF) is equal for all wavelengths. In order to test this hypothesis, JPL's Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) is used to measure polarization information of different outdoor surface types. GroundMSPI measures the linear polarization Stokes parameters (I, Q, U), at three wavelengths, 470 nm, 660 nm, and 865 nm. The camera is mounted on a two-axis gimbal to accurately select the view azimuth and elevation directions. On clear sky days we acquired day-long scans of scenes that contain various surface types such as grass, dirt, cement, brick, and asphalt and placed a Spectralon panel in the camera field of view to provide a reflectance reference. Over the course of each day, changing solar position in the sky provides a large range of scattering angles for this study. The polarized bidirectional reflectance factor (pBRF) is measured for the three wavelengths and the best fit slope of the spectral correlation is reported. This work reports the range of best fit slopes measured for five region types.
Chapter 11 Hydrogen-Related Phenomena in Crystalline Germanium

Publisher Summary This chapter describes hydrogen (H)-related germanium phenomena in crystalline. It discusses the properties of the various hydrogen-containing centers and the methods with which they can be generated. Because of the intimate coupling between the crystal growth parameters and the formation of hydrogen-related centers, the chapter summarizes the ultra-pure germanium crystal growth technology and appropriate characterization methods. Because of the high purity that can be achieved, single-crystal germanium was the first semiconductor in which the active role of H was discovered. The chapter describes the way hydrogen can either neutralize shallow-level centers, playing an amphoteric role because it can neutralize either donors or acceptors, or activate neutral impurities, giving some of them shallow donor and others shallow acceptor character. In fact, depending on the number of H involved, multivalent acceptors can be partially or fully neutralized. The dynamic nature of H with the dramatic change in the 1s-like ground state of the triple acceptor copper when it is partially neutralized with two H, one H and one D, or two D is discussed in the chapter.
The Cortical Dopamine System: Role in Memory and Cognition

Publisher Summary There are three distinct possible cellular mechanisms that have so far been identified for dopamine modulation of working memory function in the prefrontal cortex. These are: direct synaptic modulation of receptors on the distal dendrites and spines of pyramidal neurons, direct nonsynaptic modulation of pyramidal neurons, and indirect synaptic modulation of pyramidal neurons via feedforward inhibition from GABAergic interneurons. As the majority of the dopamine synapses appear to be formed on pyramidal neurons, dopamine axons are thus placed in direct contact with the major projection neurons of the prefrontal cortex. Nonsynaptic neurotransmission may be the more pervasive means of altering pyramidal cell activity, because numerous dopamine varicosities are observed in nonsynaptic relationship to cortical elements. Members of the D1 family of dopamine receptors have been found to be particularly prominent in the prefrontal cortex of primates, and both D1 and D5 receptor proteins have been localized to the distal dendrites and spines of pyramidal cells. A third mechanism of dopamine action is indirect, appearing to involve feedforward inhibition on pyramidal neurons from nonpyramidal neurons. The indirect action of dopamine on this circuit derives from the identification of dopamine synapses on nonpyramidal GABAergic neurons in the prefrontal cortex and the finding that the D4 member of the D2 family of dopamine receptors is localized postsynaptically on a subset of GABA interneurons. These findings provide suggestive evidence that feedforward inhibition may play a role in the construction of a memory field in prefrontal neurons. The different effects of dopamine may depend on the subtype of interneuron engaged, and future studies may indicate the basis for the differential modulation of interneurons by dopamine.
Boundaries in science policy making: Bovine growth hormone in the European Union

We simultaneously explore the history of European Union policy on the commercialization of recombinant bovine growth hormone and the sociology of boundary drawing. We argue that, to understand why some boundary-drawing efforts succeed and others fail, we need to be attentive to the relatively stable discursive, organizational, and institutional factors that shape boundary construction. We suggest that attention to two discourses (scientism and social welfarism), the structure of policy making in the European Union, and the institutionalization of particular discourses in World Trade Organization regulations shed light on the E.U.-rbGH case.
Microcysts of the Cellular Slime Mold Polysphondylium pallidum I. Factors Influencing Microcyst Formation

Microcyst formation can be induced by increasing the osmotic pressure of the surrounding medium. Certain ions such as K(+), Ca(++), or Mg(++) may be needed in the encystment process, and the presence of divalent cations increases the rate of encystment and cyst maturation. Chloride of potassium is optimal for encystment, but other anions of potassium are either less effective or toxic. The optimal pH for encystment was found to be pH 6.0. The use of agar plates containing KCl revealed the importance to the encystment process of inhibiting cell aggregation. When myxamoebae of Polysphondylium pallidum strain Pan-17 are deposited on KCl-agar plates, approximately 20% of the population proceeds through aggregation to sorocarp formation at the concentration of KCl optimal for microcyst formation. However, the same proportion of myxamoebae remains unaligned, or forms defective aggregation centers, if synergistic inhibitors (such as incubation in darkness or at low temperature) are employed in addition to KCl. The possibility that this is due to heterocytosis has been excluded. Accordingly, it is suggested that during the stationary phase approximately 20% of the population becomes committed to forming component cells of fruiting bodies, and that these myxamoebae cannot be induced to form microcysts by exposure to KCl. In P. pallidum strains WS-320 on the other hand, the imposition of synergistic inhibitors leads to the total encystment of the cell population. This suggests that, in contrast to Pan-17, the myxamoebae of the latter strain remain potentially equal and exhibit minimal presumptive specialization.
Econometrics: Models of Regime Changes.

Filtered probability of a regime The probability that the unobserved Markov chain for a Markov-switching model is in a particular regime in period t, conditional on observing sample information up to period t. Gibbs sampler An algorithm to generate a sequence of samples from the joint probability distribution of a group of random variables by repeatedly sampling from the full set of conditional distributions for the random variables. Markov chain A process that consists of a finite number of states, or regimes, where the probability of moving to a future state conditional on the present state is independent of past states. Markov-switching model A regime-switching model in which the shifts between regimes evolve according to an unobserved Markov chain. Regime-Switching Model A parametric model of a time series in which parameters are allowed to take on different values in each of some fixed number of regimes. Smooth transition threshold model A threshold model in which the effect of a regime shift on model parameters is phased in gradually, rather than occurring abruptly. Smoothed probability of a regime The probability that the unobserved Markov chain for a Markov-switching model is in a particular regime in period t, conditional on observing all sample information. Threshold model A regime-switching model in which the shifts between regimes are triggered by the level of an observed economic variable in relation to an unobserved threshold. Time-varying transition probability A transition probability for a Markov chain that is allowed to vary depending on the outcome of observed information. Transition probability The probability that a Markov chain will move from state j to state i.
Single Cell Nanobiosensors for Dynamic Gene Expression Profiling in Native Tissue Microenvironments

A gold nanorod-locked nucleic acid nano-biosensor for dynamic single-cell gene expression analysis in living cells and tissues is developed. The nanoparticle facilitates endocytic delivery and dynamic monitoring of the gene expression in human umbilical cord endothelial cells, mouse skin tissues, mouse retina tissues, and mouse cornea tissues at the single-cell level.
Regulation in the Behavioral Era

Administrative agencies have long proceeded on the assumption that individuals respond to regulations in ways that are consistent with traditional rational actor theory, but that is beginning to change. Agencies are now relying on behavioral economics to develop regulations that account for responses that depart from common sense and common wisdom, reflecting predictable cognitive anomalies. Furthermore, political officials have now called for behavioral economics to play an explicit role in White House review of agency regulations. This is a significant development for the regulatory process, yet our understanding of how behavioral insights should alter regulatory analysis is incomplete. To account for behavioral anomalies, regulators will need to draw on behavioral and social science insights beyond behavioral economics, and they will need an analytic framework to ensure that regulatory decisions reflect a comprehensive examination of the numerous, seemingly haphazard behavioral insights. Although behavioral research has demonstrated the limits of rational action, it does not provide a framework for considering extra-rational action. Nor have legal scholars developed such a framework, despite excellent theoretical work in the area. In this Article, we take an initial step. We provide a framework to facilitate agency consideration of extra-rational action and extend that framework to include a lesson from behavioral research that academics have noted but not adequately explored: that individuals are concerned with social outcomes (e.g., social status or inclusion) as well as monetary outcomes (e.g., wealth) and that they seek to maximize utility in both rational and extra-rational ways. After sketching our framework, we offer concrete applications in the energy use context. Our framework does not resolve all issues that may arise in the behavioral era, but it provides a means to move forward.
Fighting Bloat with Nonparametric Parsimony Pressure

Many forms of parsimony pressure are parametric, that is final fitness is a parametric model of the actual size and raw fitness values. The problem with parametric techniques is that they are hard to tune to prevent size from dominating fitness late in the evolutionary run, or to compensate for problem-dependent nonlinearities in the raw fitness function. In this paper we briefly discuss existing bloat-control techniques, then introduce two new kinds of non-parametric parsimony pressure, Direct and Proportional Tournament. As their names suggest, these techniques are based on simple modifications of tournament selection to consider both size and fitness, but not together as a combined parametric equation. We compare the techniques against, and in combination with, the most popular genetic programming bloat-control technique, Koza-style depth limiting, and show that they are effective in limiting size while still maintaining good best-fitness-of-run results.
Premises, Promises, and Potential Payoffs of Responsible Health Education.

(1997). Premises, Promises and Potential Payoffs of Responsible Health Education. Journal of Health Education: Vol. 28, No. 5, pp. 298-307.
Early Mobility Activities During Continuous Renal Replacement Therapy

Continuous renal replacement therapy (CRRT) is a therapeutic technique used to support critically ill patients with acute renal failure in intensive care units. CRRT is preferred over hemodialysis for patients who cannot tolerate the rapid fluid and electrolyte shifts associated with hemodialysis because of their tenuous hemodynamic state. Traditionally, such patients have not been candidates for mobilization and have remained on strict bed rest. Mobilization is now being initiated on patients undergoing CRRT in intensive care units. This case study chronicles the successful mobilization of a patient undergoing CRRT. This experience suggests that CRRT patients who are appropriate candidates may be mobilized safely and therefore should not automatically be excluded from mobilization therapies.
Assignment of the 13C-NMR spectrum of phenanthro[4,3-a]dibenzothiophene through the utilization of two-dimensional relayed coherence transfer and double quantum coherence spectroscopy

Total assignment of the 13C-nmr spectrum of the helical molecule phenanthro[4,3-a]dibenzothiophene at 125.762 MHz is reported. Assignments were made by the combined application of 13C-13C autocorrelated double quantum coherence and heteronuclear relayed coherence transfer (RELAY) experiments.
Jesus Didn’t Teach Us to Juggle Religious Involvement, Work–Family Conflict, and Life Satisfaction Among African Americans

Growing research suggests that work–family conflict is harmful to individual well-being. However, few studies have examined this relationship among African Americans, as well as what cultural institutions and practices may help in dealing with the stress of work–family conflict. This study suggests that religion may be an important resource for African Americans in the face of work–family conflict. Using data from the National Survey of Religion and Family Life, a telephone survey of working-age U.S. adults, this study outlines a series of arguments linking work–family conflict, religious involvement, and life satisfaction among African Americans. The results suggest some support for religious involvement in moderating—or buffering—the harmful effects of work–family conflict on the life satisfaction of African Americans. Study limitations are identified and several promising directions for future research are discussed.
Who Uses a Means-Tested Scholarship, and What Do They Choose?.

Abstract This paper provides detailed evidence regarding the nature of selection into a school voucher system. We use micro-data on scholarship applications matched with state student-level records on test scores, schools attended, and demographic background characteristics to describe the attributes of students who choose to participate in Florida's Corporate Tax Credit Scholarship Program, a means-tested scholarship program that is the largest of its type in the United States. We find evidence that those who choose to participate in the program tend to be lower-performing students from poorly performing schools, and that students of different backgrounds tend to choose different types of private schools. Students participating in the program tend to select schools that have more white students and fewer minority students, regardless of student race.
Dynamic Shear Behavior of a Needle-Punched Geosynthetic Clay Liner

An experimental investigation of the dynamic internal shear behavior of a hydrated needle-punched geosynthetic clay liner is presented. Monotonic and cyclic displacement-controlled shear tests were conducted at a single normal stress to investigate the effects of displacement rate, displacement amplitude, number of cycles, frequency, and motion waveform on material response. Monotonic shear tests indicate that peak shear strength first increased and then decreased with increasing displacement rate. Cyclic shear tests indicate that cyclic response was primarily controlled by displacement amplitude. Excitation frequency and waveform had little effect on cyclic shear behavior or postcyclic static shear strength. Number of cycles (greater than or equal to 10) also had little effect on postcyclic static shear strength. Shear stress versus shear displacement diagrams displayed hysteresis loops that are broadly similar to those for natural soils with some important differences due to the presence of needle-punched reinforcement. Secant shear stiffness displayed strong reduction with increasing displacement amplitude and degradation with continued cycling. Values of damping ratio were significantly higher than those typical of natural clays at lower shear strain levels. Finally, cyclic tests with increasing displacement amplitude yielded progressively lower postcyclic static peak strengths due to greater levels of reinforcement damage. Postcyclic static residual strengths were unaffected by prior cyclic loading.
Transmission of human immunodeficiency virus type 1 from a patient who developed AIDS to an elite suppressor.

Elite suppressors (ES) are untreated human immunodeficiency virus type 1 (HIV-1)-infected patients who maintain viral loads of <50 copies/ml. The mechanisms involved in this control of viral replication remain unclear. Prior studies suggested that these patients, as well as long-term nonprogressors, are infected with defective HIV-1 variants. Other reports have shown that the HLA-B*27 and -B*57 alleles are overrepresented in these patients, suggesting that host factors play a role in the control of viral replication. In order to distinguish between these hypotheses, we studied differences in viral isolates and immune responses of an HIV-1 transmission pair. While both patients are HLA-B*57 positive, the transmitter progressed to AIDS, whereas the recipient, who is also HLA-B*27 positive, is an ES. Isolates from both patients were replication competent and contained the T242N escape mutation in Gag, which is known to decrease viral fitness. While the acquisition of compensatory mutations occurred in isolates from the progressor, a superior HIV-specific CD8+ T-cell response in the ES appears to have prevented viral replication and thus the evolution toward a more fit variant. In addition, CD8+ T cells in the ES have selected for a rare mutation in an immunodominant HLA-B*27-restricted Gag epitope, which also has a negative impact on fitness. The results strongly suggest that through direct and indirect mechanisms, CD8+ T cells in some ES control HIV-1 isolates are capable of causing profound immunosuppression.
Nonlinear equations with mixed derivatives

Abstract Partial differential equations involving mixed derivatives are investigated using decomposition.
Trash DNA is what gets thrown away: high rate of DNA loss in Drosophila.

Abstract We have recently described a novel method of estimating neutral rates and patterns of spontaneous mutation (Petrov et al., 1996). This method takes advantage of the propensity of non-LTR retrotransposable elements to create non-functional, ‘dead-on-arrival’ copies as a product of transposition. Maximum parsimony analysis is used to separate the evolution of actively transposing lineages of a non-LTR element from the fate of individual inactive insertions, and thereby allows one to assess directly the relative rates of different types of mutation, including point substitutions, deletions and insertions. Because non-LTR elements enjoy wide phylogenetic distribution, this method can be used in taxa that do not harbor a significant number of bona fide pseudogenes, as is the case in Drosophila (Jeffs and Ashburner, 1991; Weiner et al., 1986). We used this method with Helena, a non-LTR retrotransposable element present in the Drosophila virilis species group. A striking finding was the virtual absence of insertions and remarkably high incidence of large deletions, which combine to produce a high overall rate of DNA loss. On average, the rate of DNA loss in D. virilis is approximately 75 times faster than that estimated for mammalian pseudogenes (Petrov et al., 1996). The high rate of DNA loss should lead to rapid elimination of non-essential DNA and thus may explain the seemingly paradoxical dearth of pseudogenes in Drosophila. Varying rates of DNA loss may also contribute to differences in genome size (Graur et al., 1989; Petrov et al., 1996), thus explaining the celebrated ‘C-value’ paradox (John and Miklos, 1988). In this paper we outline the theoretical basis of our method, examine the data from this perspective, and discuss potential problems that may bias our estimates.
Short- and long-range interactions of slow electrons in condensed matter: Effects on reflection and transmission.

The Coulomb interaction of an electron with each electron or nucleus in its environment is Fourier analyzed into components with wave vectors q. These components are classified as long (short) range when q is smaller (larger) than the electron's wave number p. The contrasting characteristics of each class are discussed. Electron reflection at a material's surface measures the effect of short-range components only.
Factors influencing the measurement of pulmonary extravascular water.

Abstract The change in pulmonary extravascular water calculated from indicator-dilution curves recorded by 125 RISA and 131 iodoantipyrene was compared to the weighed lung water in five groups of dogs. Four of these groups were kept hypotensive for 2 hr by hemorrhage, then reinfused with blood. They then received isoproteranol, methylprednisolone, phenoxybenzamine, or no drug. A fifth group was anesthetized for 4 hr, but kept normotensive. Hypotension, or prolonged anesthesia caused a recruitment of pulmonary capillaries in spite of a decreased cardiac output. This recruitment was decreased by isoproteranol or methylprednisolone and was unaffected by phenoxybenzamine. The recovery of RISA decreased during the course of all experiments. This decrease may be due to segmental areas of venous obstruction. Only in the group of animals receiving phenoxybenzamine after hypotension were the typical changes of congestive atelectasis seen.
SITDEM: A simulation tool for disease/endpoint models of association studies based on single nucleotide polymorphism genotypes

The association analysis between single nucleotide polymorphisms (SNPs) and disease or endpoint in genome-wide association studies (GWAS) has been considered as a powerful strategy for investigating genetic susceptibility and for identifying significant biomarkers. The statistical analysis approaches with simulated data have been widely used to review experimental designs and performance measurements. In recent years, a number of authors have proposed methods for the simulation of biological data in the genomic field. However, these methods use large-scale genomic data as a reference to simulate experiments, which may limit the use of the methods in the case where the data in specific studies are not available. Few methods use experimental results or observed parameters for simulation. The goal of this study is to develop a Web application called SITDEM to simulate disease/endpoint models in three different approaches based on only parameters observed in GWAS. In our simulation, a key task is to compute the probability of genotypes. Based on that, we randomly sample simulation data. Simulation results are shown as a function of p-value against odds ratio or relative risk of a SNP in dominant and recessive models. Our simulation results show the potential of SITDEM for simulating genotype data. SITDEM could be particularly useful for investigating the relationship among observed parameters for target SNPs and for estimating the number of variables (SNPs) required to result in significant p-values in multiple comparisons. The proposed simulation tool is freely available at http://www.snpmodel.com.
Asparagine-linked glycoprotein biosynthesis in rat brain: Identification of glucosidase I, glucosidase II, and an endomannosidase (glucosyl mannosidase)☆

Abstract Previous studies from this laboratory provided evidence, largely based upon the presence of a novel α- d -mannosidase, suggesting that the biosynthesis of N-linked glycoproteins may be different in brain as compared to other tissues (Tulsiani, D. R. P., and Touster, O. (1985) J. Biol. Chem. 260, 13,081–13,087). In the present report we describe studies on the enzymes involved in early processing reactions. These studies indicate that the brain, like other tissues, contains glucosidases I and II. The two glucosidases were separated as distinct activities with some overlapping by chromatography on a DE-52 column. The differential inhibition studies and substrate specificity studies support our conclusion that, as in other tissues, rat brain glucosidase I cleaves α1,2-linked terminal glucosyl residues, whereas glucosidase II prefers α1,3-linked glucosyl residues. In addition to these two processing glucosidases, we have characterized an endo enzyme (glucosyl mannosidase) in rat brain. The endomannosidase cleaves a disaccharide (glucosyl α1,3-mannose) from monoglucosylated oligosaccharides (GlcMan7–9GlcNAc). Little or no activity was observed when di- or triglucosylated oligosaccharide was used as a substrate. The pH optimum of the glucosyl mannosidase is 6.2–6.8. The enzyme appears to be an intrinsic microsomal membrane component, since washing of the microsomal membranes with salt solution did not release the enzyme in soluble form. A mixture of Triton X-100 and sodium deoxycholate is required for complete solubilization of the enzyme. The solubilized enzyme is eluted from a Bio-Gel A-1.5m column as a single peak with an apparent molecular weight of 380,000.
Systematic Review of Childhood Obesity Prevention

This systematic review identified the current state of the evidence related to the prevention of obesity in young children. The results indicate five areas of emphasis in the literature: prevalence of the problem; prevention as the best option; preschool population as the target; crucial parental involvement; and numerous guidelines. Because the gap between clear articulation of the problem as well as population and the best strategies to impact the prevention of the problem is evident, health care practitioners must be involved in well-constructed implementation and evaluation studies that build on the limited base of current evidence.
Pulsatile Left Ventricular Assist Devices: What Is the Role in the Modern Era?

With the widespread use of continuous-flow ventricular assist devices (VADs), the role of pulsatile VADs remain in question. In acute cardiogenic shock, pulsatile VADs maximize perfusion pressure, restore end organ perfusion, and maximally unload the pulmonary circulation and right heart. In addition, pulsatile left VADs allow for easy conversion to biventricular support using one platform, in the case of acute right ventricular failure. Pulsatile VADs still have a major role in the treatment of acute cardiogenic shock.
Loss and Grief Experiences of Mentors in Social Work Education

Mentoring is an important process in educating competent professionals. However, little is known about mentors' experiences in social work higher education. Two social work educators reflect on 21 years of mentoring with over 60 social work students. Data are triangulated from the notes of two cross‐interviews, separately prepared written descriptions of mentoring experiences, and the professional literature. The mentors identify loss and grief experiences, particularly those that take place during the separation and redefinition phases of the mentoring relationships (Kram, 1983). Especially if future research supports the finding of this study, social work education administrators and faculty need to recognize, acknowledge, and ameliorate potential loss and grief experiences of mentors.
Molecular basis of cooperativity in vertebrate muscle thin filaments

Extraction of as little as one troponin C per regulatory strand on a thin filament reduces the slope of the pCa/tension relation thus the regulatory units along a thin filament of rabbit psoas fibers are linked cooperatively so that a thin filament activates as a unit. This explains why the pCa/tension relation in skinned fibers has a slope much higher than can be expected by binding of Ca2+ to one regulatory unit (Brandt et al. 1980;Brandt et al. 1982). These results also show that troponin C is the only myfibrillar component responsible for calcium sensitivity in psoas muscle.
Temperature Effects on the Growth of Blue Tilapia in Intensive Aquaculture

Abstract Blue tilapias (Oreochromis aureus) were grown at 20, 25, and 30°C in closed aquaculture systems to develop a growth model for flowing-water husbandry of this species. Blue tilapias required 0.69 ± 0.05 temperature units (TU) per millimeter of growth in length (mean ± 95% confidence level; 1 TU = 1°C above 17.8°C maintained for 30 d). This requirement was verified in a second experiment in which blue tilapias were grown at 28°C on feed rations calculated from anticipated growth. The daily length increment (▵L, mm) of blue tilapias grown at constant temperature (T, °C) within the range 20–30°C can be predicted from the equation ▵L = 0.048T – 0.853.