cssi/SciSciGPT-SciSciNet huggingface dataset:
Normal modes with boundary dynamics in geophysical fluids

Three-dimensional geophysical fluids support both internal and boundary-trapped waves. To obtain the normal modes in such fluids, we must solve a differential eigenvalue problem for the vertical structure (for simplicity, we only consider horizontally periodic domains). If the boundaries are dynamically inert (e.g., rigid boundaries in the Boussinesq internal wave problem and flat boundaries in the quasigeostrophic Rossby wave problem), the resulting eigenvalue problem typically has a Sturm–Liouville form and the properties of such problems are well-known. However, when restoring forces are also present at the boundaries, then the equations of motion contain a time-derivative in the boundary conditions, and this leads to an eigenvalue problem where the eigenvalue correspondingly appears in the boundary conditions. In certain cases, the eigenvalue problem can be formulated as an eigenvalue problem in the Hilbert space L2⊕C and this theory is well-developed. Less explored is the case when the eigenvalue problem takes place in a Pontryagin space, as in the Rossby wave problem over sloping topography. This article develops the theory of such problems and explores the properties of wave problems with dynamically active boundaries. The theory allows us to solve the initial value problem for quasigeostrophic Rossby waves in a region with sloping bottom (we also apply the theory to two Boussinesq problems with a free-surface). For a step-function perturbation at a dynamically active boundary, we find that the resulting time-evolution consists of waves present in proportion to their projection onto the dynamically active boundary.
Functional observers with linear error dynamics for nonlinear systems

Abstract In this work, the problem of designing observers for estimating a single nonlinear functional of the state is formulated for general nonlinear systems. Notions of functional observer linearization are also formulated, in terms achieving exactly linear error dynamics in transformed coordinates and with prescribed rate of decay of the error. Necessary and sufficient conditions for the existence of a lower-order functional observer with linear dynamics are derived. The results provide a direct generalization of Luenberger’s linear theory of functional observers to nonlinear systems.
Trisections and link surgeries

We examine questions about surgery on links which arise naturally from the trisection decomposition of 4-manifolds developed by Gay and Kirby \cite{G-K3}. These links lie on Heegaard surfaces in $\#^j S^1 \times S^2$ and have surgeries yielding $\#^k S^1 \times S^2$. We describe families of links which have such surgeries. One can ask whether all links with such surgeries lie in these families; the answer is almost certainly no. We nevertheless give a small piece of evidence in favor of a positive answer.
Synthesizing Multi-Tracer PET Images for Alzheimer's Disease Patients using a 3D Unified Anatomy-aware Cyclic Adversarial Network

Positron Emission Tomography (PET) is an important tool for studying Alzheimer’s disease (AD). PET scans can be used as diagnostics tools, and to provide molecular characterization of patients with cognitive disorders. However, multiple tracers are needed to measure glucose metabolism (\(^{18}\)F-FDG), synaptic vesicle protein (\(^{11}\)C-UCB-J), and \(\beta \)-amyloid (\(^{11}\)C-PiB). Administering multiple tracers to patient will lead to high radiation dose and cost. In addition, access to PET scans using new or less-available tracers with sophisticated production methods and short half-life isotopes may be very limited. Thus, it is desirable to develop an efficient multi-tracer PET synthesis model that can generate multi-tracer PET from single-tracer PET. Previous works on medical image synthesis focus on one-to-one fixed domain translations, and cannot simultaneously learn the feature from multi-tracer domains. Given 3 or more tracers, relying on previous methods will also create heavy burden on the number of models to be trained. To tackle these issues, we propose a 3D unified anatomy-aware cyclic adversarial network (UCAN) for translating multi-tracer PET volumes with one unified generative model, where MR with anatomical information is incorporated. Evaluations on a multi-tracer PET dataset demonstrate the feasibility that our UCAN can generate high-quality multi-tracer PET volumes, with NMSE less than \(15\%\) for all PET tracers. Our code is available at https://github.com/bbbbbbzhou/UCAN.
Deep learning for reduced order modelling and efficient temporal evolution of fluid simulations

Reduced order modeling (ROM) has been widely used to create lower order, computationally inexpensive representations of higher-order dynamical systems. Using these representations, ROMs can efficiently model flow fields while using significantly lesser parameters. Conventional ROMs accomplish this by linearly projecting higher-order manifolds to lower-dimensional space using dimensionality reduction techniques such as proper orthogonal decomposition (POD). In this work, we develop a novel deep learning framework DL-ROM (deep learning—reduced order modeling) to create a neural network capable of non-linear projections to reduced order states. We then use the learned reduced state to efficiently predict future time steps of the simulation using 3D Autoencoder and 3D U-Net-based architectures. Our model DL-ROM can create highly accurate reconstructions from the learned ROM and is thus able to efficiently predict future time steps by temporally traversing in the learned reduced state. All of this is achieved without ground truth supervision or needing to iteratively solve the expensive Navier–Stokes (NS) equations thereby resulting in massive computational savings. To test the effectiveness and performance of our approach, we evaluate our implementation on five different computational fluid dynamics (CFD) datasets using reconstruction performance and computational runtime metrics. DL-ROM can reduce the computational run times of iterative solvers by nearly two orders of magnitude while maintaining an acceptable error threshold.
OpenGAN: Open-Set Recognition via Open Data Generation

Real-world machine learning systems need to analyze novel testing data that differs from the training data. In K-way classification, this is crisply formulated as open-set recognition, core to which is the ability to discriminate open-set data outside the K closed-set classes. Two conceptually elegant ideas for open-set discrimination are: 1) discriminatively learning an open-vs-closed binary discriminator by exploiting some outlier data as the open-set, and 2) unsupervised learning the closed-set data distribution with a GAN and using its discriminator as the open-set likelihood function. However, the former generalizes poorly to diverse open test data due to overfitting to the training outliers, which unlikely exhaustively span the open-world. The latter does not work well, presumably due to the instable training of GANs. Motivated by the above, we propose OpenGAN, which addresses the limitation of each approach by combining them with several technical insights. First, we show that a carefully selected GAN-discriminator on some real outlier data already achieves the state-of-the-art. Second, we augment the available set of real open training examples with adversarially synthesized "fake" data. Third and most importantly, we build the discriminator over the features computed by the closed-world K-way networks. Extensive experiments show that OpenGAN significantly outperforms prior open-set methods.
Molecular Dynamic Characteristic Temperatures for Predicting Metallic Glass Forming Ability

Abstract We explore the use of characteristic temperatures derived from molecular dynamics to predict aspects of metallic Glass Forming Ability (GFA). Temperatures derived from cooling curves of self-diffusion, viscosity, and energy were used as features for machine learning models of GFA. Multiple target and model combinations with these features were explored. First, we use the logarithm of critical casting thickness, l o g 10 ( D m a x ) , as the target and trained regression models on 21 compositions. Application of 3-fold cross-validation on the 21 l o g 10 ( D m a x ) alloys showed only weak correlation between the model predictions and the target values. Second, the GFA of alloys were quantified by melt-spinning or suction casting amorphization behavior, with alloys that showed crystalline phases after synthesis classified as Poor GFA and those with pure amorphous phases as Good GFA. Binary GFA classification was then modeled using decision tree-based methods (random forest and gradient boosting models) and were assessed with nested-cross validation. The maximum F1 score for the precision–recall with Good Glass Forming Ability as the positive class was 0 . 82 ± 0 . 01 for the best model type. We also compared using simple functions of characteristic temperatures as features in place of the temperatures themselves and found no statistically significant difference in predictive abilities. Although the predictive ability of the models developed here are modest, this work demonstrates clearly that one can use molecular dynamics simulations and machine learning to predict metal glass forming ability.
Low-Dose Whole Thorax Radiation Therapy for COVID-19 Pneumonia: Inpatient Onboarding Process for a Randomized Controlled Trial

Purpose/objective(s) The mortality of the SARS-CoV-2 virus (COVID-19) has been associated with a pulmonary inflammatory response resulting in hypoxemia and rapid clinical decline. Recent work has indicated a potential therapeutic window for treatment to prevent ventilator-dependence thereby reducing mortality. PREVENT is an ongoing prospective multicenter Phase II randomized controlled trial where patients hospitalized with COVID-19 pneumonia are randomized to ultra-low dose radiation therapy (RT) versus control. This study is registered at clinicaltrials.gov, NCT04466683. The following is a description of the inpatient onboarding process of the center contributing the largest number of patients to this trial. Materials/methods COVID-19 hospital admissions from the previous day were attained by the clinical research manager each morning, screened for eligibility, and then sent to the designated radiation oncologist who further delineated from this list. Common exclusion criteria were: 1. Oxygen saturation > 96% on room air, 2. Age 9 days from initial COVID-19 symptomatology. From this list, HIPAA-compliant text message contact was made with infectious disease, critical care, and nursing staff with reciprocal discussion of the trial protocol and approval for consulting the patient. Subsequently, a virtual consult was made with the patient, with witnessed informed consent obtained via telephone and in person by our research associate. Patients randomized to RT were treated within 24 hours of consent. Simulation and treatment were performed on a linear accelerator with one personal protective equipment-protected therapist moving in and out of the treatment room, and a second therapist manning the console. On-site dose calculation was performed by physics, after which the radiation oncologist approved the fields prior to treatment delivery. Simulation and treatment were performed without a computer plan; therapists underwent several practice sessions prior to treating patients on trial. Results Between August 28, 2020 and October 6, 2020, the first 10 enrolled patients on this multicenter trial were randomized and treated at our institution; no research staff member nor radiation oncology clinical team member contracted COVID-19 while employing this protocol. Conclusion This represents the first published protocol to address efficient and safe recruitment of COVID-19 patients for a radiation oncology trial. Despite the procedural hurdles of conducting a trial in the midst of a pandemic, the combination of recruitment efficiency (> 2 patients/week) and safety to the research and clinical teams (no COVID-19 infections) of this protocol has allowed for the PREVENT trial to make substantial progress in meeting recruitment goals (n = 100). This onboarding process serves as a model in conducting recruitment of COVID-19 patients for clinical trials, and is worthy of emulation at additional centers.
Inverse designed extended depth of focus meta-optics for broadband imaging in the visible

We report an inverse-designed, high numerical aperture (~0.44), extended depth of focus (EDOF) meta-optic, which exhibit a lens-like point spread function (PSF). The EDOF meta-optic maintains a focusing efficiency comparable to that of a hyperboloid metalens throughout its depth of focus. Exploiting the extended depth of focus and computational post-processing, we demonstrate broadband imaging across the full visible spectrum using a 1 mm, f/1 meta-optic. Unlike other canonical EDOF meta-optics, characterized by phase masks such as a log-asphere or cubic function, our design exhibits a highly invariant PSF across a larger optical bandwidth, which leads to significantly improved image quality.
Axis-Aligned Square Contact Representations.

We introduce a new class $\mathcal{G}$ of plane bipartite graphs and prove that each graph in $\mathcal{G}$ admits a proper square contact representation. A contact between two squares is \emph{proper} if they intersect in a line segment of positive length. The class $\mathcal{G}$ is the family of quadrangulations obtained from the 4-cycle $C_4$ by successively inserting a single vertex or a 4-cycle of vertices into a face.
SQRP: Sensing Quality-aware Robot Programming System for Non-expert Programmers

Robot programming typically makes use of a set of mechanical skills that is acquired by machine learning. Because there is in general no guarantee that machine learning produces robot programs that are free of surprising behavior, the safe execution of a robot program must utilize monitoring modules that take sensor data as inputs in real time to ensure the correctness of the skill execution. Owing to the fact that sensors and monitoring algorithms are usually subject to physical restrictions and that effective robot programming is sensitive to the selection of skill parameters, these considerations may lead to different sensor input qualities such as the view coverage of a vision system that determines whether a skill can be successfully deployed in performing a task. Choosing improper skill parameters may cause the monitoring modules to delay or miss the detection of important events such as a mechanical failure. These failures may reduce the throughput in robotic manufacturing and could even cause a destructive system crash. To address above issues, we propose a sensing quality-aware robot programming system that automatically computes the sensing qualities as a function of the robot’s environment and uses the information to guide non-expert users to select proper skill parameters in the programming phase. We demonstrate our system framework on a 6DOF robot arm for an object pick-up task.
Multiscale Clustering of Hyperspectral Images Through Spectral-Spatial Diffusion Geometry

Clustering algorithms partition a dataset into groups of similar points. The primary contribution of this article is the Multiscale Spatially-Regularized Diffusion Learning (M-SRDL) clustering algorithm, which uses spatially-regularized diffusion distances to efficiently and accurately learn multiple scales of latent structure in hyperspectral images (HSI). The M-SRDL clustering algorithm extracts clusterings at many scales from an HSI and outputs these clusterings' variation of information-barycenter as an exemplar for all underlying cluster structure. We show that incorporating spatial regularization into a multiscale clustering framework corresponds to smoother and more coherent clusters when applied to HSI data and leads to more accurate clustering labels.
Haptic Feedback Improves Human-Robot Agreement and User Satisfaction in Shared-Autonomy Teleoperation

Shared autonomy teleoperation can guarantee safety, but does so by reducing the human operator’s control authority, which can lead to reduced levels of human-robot agreement and user satisfaction. This paper presents a novel haptic shared autonomy teleoperation paradigm that uses haptic feedback to inform the user about the inner state of a shared autonomy paradigm, while still guaranteeing safety. This differs from haptic shared control, which uses haptic feedback to inform the user’s actions, but gives the human operator full control over the robot’s actions. We conducted a user study in which twelve users flew a simulated UAV in a search-and-rescue task with no assistance or assistance provided by haptic shared control, shared autonomy, or haptic shared autonomy. All assistive teleoperation methods use control barrier functions to find a control command that is both safe and as close as possible to the human-generated control command. For assistive teleoperation conditions with haptic feedback, we apply a force to the user that is proportional to the difference between the human-generated control and the safe control. We find that haptic shared autonomy improves the user’s task performance and satisfaction. We also find that haptic feedback in assistive teleoperation can improve the user’s situational awareness. Finally, results show that adding haptic feedback to shared-autonomy teleoperation can improve human-robot agreement.
DNA Replication-Transcription Conflicts Do Not Significantly Contribute to Spontaneous Mutations Due to Replication Errors in Escherichia coli.

Encounters between DNA replication and transcription can cause genomic disruption, particularly when the two meet head-on. Whether these conflicts produce point mutations is debated. This paper presents detailed analyses of a large collection of mutations generated during mutation accumulation experiments with mismatch repair (MMR)-defective Escherichia coli. With MMR absent, mutations are primarily due to DNA replication errors. Overall, there were no differences in the frequencies of base pair substitutions or small indels (i.e., insertion and deletions of ≤4 bp) in the coding sequences or promoters of genes oriented codirectionally versus head-on to replication. Among a subset of highly expressed genes, there was a 2- to 3-fold bias for indels in genes oriented head-on to replication, but this difference was almost entirely due to the asymmetrical genomic locations of tRNA genes containing mononucleotide runs, which are hot spots for indels. No additional orientation bias in mutation frequencies occurred when MMR- strains were also defective for transcription-coupled repair (TCR). However, in contrast to other reports, loss of TCR slightly increased the overall mutation rate, meaning that TCR is antimutagenic. There was no orientation bias in mutation frequencies among the stress response genes that are regulated by RpoS or induced by DNA damage. Thus, biases in the locations of mutational targets can account for most, if not all, apparent biases in mutation frequencies between genes oriented head-on versus codirectional to replication. In addition, the data revealed a strong correlation of the frequency of base pair substitutions with gene length but no correlation with gene expression levels. IMPORTANCE Because DNA replication and transcription occur on the same DNA template, encounters between the two machines occur frequently. When these encounters are head-to-head, genomic disruption can occur. However, whether replication-transcription conflicts contribute to spontaneous mutations is debated. Analyzing in detail a large collection of mutations generated with mismatch repair-defective Escherichia coli strains, we found that across the genome there are no significant differences in mutation frequencies between genes oriented codirectionally and those oriented head-on to replication. Among a subset of highly expressed genes, there was a 2- to 3-fold bias for small insertions and deletions in head-on-oriented genes, but this difference was almost entirely due to the asymmetrical locations of tRNA genes containing mononucleotide runs, which are hot spots for these mutations. Thus, biases in the positions of mutational target sequences can account for most, if not all, apparent biases in mutation frequencies between genes oriented head-on and codirectionally to replication.
Enhancing Safety of Students with Mobile Air Filtration during School Reopening from COVID-19

The paper discusses how robots enable occupant-safe continuous protection for students when schools reopen. Conventionally, fixed air filters are not used as a key pandemic prevention method for public indoor spaces because they are unable to trap the airborne pathogens in time in the entire room. However, by combining the mobility of a robot with air filtration, the efficacy of cleaning up the air around multiple people is largely increased. A disinfection co-robot prototype is thus developed to provide continuous and occupant-friendly protection to people gathering indoors, specifically for students in a classroom scenario. In a static classroom with students sitting in a grid pattern, the mobile robot is able to serve up to 14 students per cycle while reducing the worst-case pathogen dosage by 20%, and with higher robustness compared to a static filter. The extent of robot protection is optimized by tuning the passing distance and speed, such that a robot is able to serve more people given a threshold of worst-case dosage a person can receive.
Swelling of a non-vascular-plant-inspired soft composite

Summary Even without the aid of muscle, plant tissue drives large, forceful motion via osmosis-driven fluid flow. Hydrogels are well-known synthetic materials that mimic this osmotic mechanism to achieve large swelling deformations. However, hydrogels can be limited by a loss of stiffness as their swelling increases. Here we demonstrate that a synthetic plant tissue analog (PTA) can mimic the closed-cell structure and osmotic actuation of non-vascular plant tissue, enabling the emergence of turgor-pressure-induced stiffness and leading to more forceful swelling deformations. PTAs consist of micrometer-sized saltwater droplets embedded within thin, highly stretchable, selectively permeable polydimethylsiloxane (PDMS) walls. When immersed in water, PTAs reach a state of equilibrium governed by the initial osmolyte concentration (higher produces more swelling) and cell wall mechanical response (stiffer and less stretchable yields less swelling). Given these behaviors, PTAs represent an alternate class of aqueous, autonomous synthetic materials that, like hydrogels, may benefit biomedical applications.
SoCCAR: Detecting System-on-Chip Security Violations Under Asynchronous Resets

Modern SoC designs include several reset domains that enable asynchronous partial resets while obviating complete system boot. Unfortunately, asynchronous resets can introduce security vulnerabilities that are difficult to detect through traditional validation. In this paper, we address this problem through a new security validation framework, SoCCCAR, that accounts for asynchronous resets. The framework involves (1) efficient extraction of reset-controlled events while avoiding combinatorial explosion, and (2) concolic testing for systematic exploration of the extracted design space. Our experiments demonstrate that SoCCAR can achieve almost perfect detection accuracy and verification time of a few seconds on realistic SoC designs.
Information-Theoretic Feature Selection via Tensor Decomposition and Submodularity

Feature selection by maximizing high-order mutual information between the selected feature vector and a target variable is the gold standard in terms of selecting the best subset of relevant features that maximizes the performance of prediction models. However, such an approach typically requires knowledge of the multivariate probability distribution of all features and the target, and involves a challenging combinatorial optimization problem. Recent work has shown that any joint Probability Mass Function (PMF) can be represented as a naive Bayes model, via Canonical Polyadic (tensor rank) Decomposition. In this paper, we introduce a low-rank tensor model of the joint PMF of all variables and indirect targeting as a way of mitigating complexity and maximizing the classification performance for a given number of features. Through low-rank modeling of the joint PMF, it is possible to circumvent the curse of dimensionality by learning ‘principal components’ of the joint distribution. By indirectly aiming to predict the latent variable of the naive Bayes model instead of the original target variable, it is possible to formulate the feature selection problem as maximization of a monotone submodular function subject to a cardinality constraint – which can be tackled using a greedy algorithm that comes with performance guarantees. Numerical experiments with several standard datasets suggest that the proposed approach compares favorably to the state-of-art for this important problem.
Covariance-Aware Private Mean Estimation Without Private Covariance Estimation

We present two sample-efficient differentially private mean estimators for $d$-dimensional (sub)Gaussian distributions with unknown covariance. Informally, given $n \gtrsim d/\alpha^2$ samples from such a distribution with mean $\mu$ and covariance $\Sigma$, our estimators output $\tilde\mu$ such that $\| \tilde\mu - \mu \|_{\Sigma} \leq \alpha$, where $\| \cdot \|_{\Sigma}$ is the Mahalanobis distance. All previous estimators with the same guarantee either require strong a priori bounds on the covariance matrix or require $\Omega(d^{3/2})$ samples. Each of our estimators is based on a simple, general approach to designing differentially private mechanisms, but with novel technical steps to make the estimator private and sample-efficient. Our first estimator samples a point with approximately maximum Tukey depth using the exponential mechanism, but restricted to the set of points of large Tukey depth. Proving that this mechanism is private requires a novel analysis. Our second estimator perturbs the empirical mean of the data set with noise calibrated to the empirical covariance, without releasing the covariance itself. Its sample complexity guarantees hold more generally for subgaussian distributions, albeit with a slightly worse dependence on the privacy parameter. For both estimators, careful preprocessing of the data is required to satisfy differential privacy.
AI Multi-Tenancy on Edge: Concurrent Deep Learning Model Executions and Dynamic Model Placements on Edge Devices

Many real-world applications are widely adopting the edge computing paradigm due to its low latency and better privacy protection. With notable success in AI and deep learning (DL), edge devices and AI accelerators play a crucial role in deploying DL inference services at the edge of the Internet. While prior works quantified various edge devices’ efficiency, most studies focused on the performance of edge devices with single DL tasks. Therefore, there is an urgent need to investigate AI multi-tenancy on edge devices, required by many advanced DL applications for edge computing. This work investigates two techniques – concurrent model executions and dynamic model placements – for AI multi-tenancy on edge devices. With image classification as an example scenario, we empirically evaluate AI multi-tenancy on various edge devices, AI accelerators, and DL frameworks to identify its benefits and limitations. Our results show that multi-tenancy significantly improves DL inference throughput by up to 3.3 × − 3.8 × on Jetson TX2. These AI multi-tenancy techniques also open up new opportunities for flexible deployment of multiple DL services on edge devices and AI accelerators.
The Limits of Optimal Pricing in the Dark

A ubiquitous learning problem in today's digital market is, during repeated interactions between a seller and a buyer, how a seller can gradually learn optimal pricing decisions based on the buyer's past purchase responses. A fundamental challenge of learning in such a strategic setup is that the buyer will naturally have incentives to manipulate his responses in order to induce more favorable learning outcomes for him. To understand the limits of the seller's learning when facing such a strategic and possibly manipulative buyer, we study a natural yet powerful buyer manipulation strategy. That is, before the pricing game starts, the buyer simply commits to "imitate" a different value function by pretending to always react optimally according to this imitative value function. We fully characterize the optimal imitative value function that the buyer should imitate as well as the resultant seller revenue and buyer surplus under this optimal buyer manipulation. Our characterizations reveal many useful insights about what happens at equilibrium. For example, a seller with concave production cost will obtain essentially 0 revenue at equilibrium whereas the revenue for a seller with convex production cost is the Bregman divergence of her cost function between no production and certain production. Finally, and importantly, we show that a more powerful class of pricing schemes does not necessarily increase, in fact, may be harmful to, the seller's revenue. Our results not only lead to an effective prescriptive way for buyers to manipulate learning algorithms but also shed lights on the limits of what a seller can really achieve when pricing in the dark.
The Slave Trade Route: A Regional and Local Development Catalyst

The conservation of and focus on slave export points turned tourist monuments in Cape Coast and Elmina, Ghana, are incomplete without linkages to other complicit places in the interior that together completes the chain of darkness, the trade in humans along the Atlantic coast of Ghana, as well as in the interior. Completed, it will highlight the infrastructure of the slave business, the domestic, as well as the Trans-Atlantic slave trade. When the chain (route) of the different complicit communities in the interior to these export monuments along the Atlantic coast is conserved, it shall herald a completeness to the slave trade business infrastructure that otherwise was disjointed, isolated, diminished, and objectified as a sort of “retail tourism.” Devoid of authenticity, these retail tourism monuments to slavery are marketed to the ill-informed casual, impressionable visitor, desirable to satisfy the euphoria of visiting a significant slave monument.
Heterogeneity of human anti-viral immunity shaped by virus, tissue, age, and sex.

Summary The persistence of anti-viral immunity is essential for protection and exhibits profound heterogeneity across individuals. Here, we elucidate the factors that shape maintenance and function of anti-viral T cell immunity in the body by comprehensive profiling of virus-specific T cells across blood, lymphoid organs, and mucosal tissues of organ donors. We use flow cytometry, T cell receptor sequencing, single-cell transcriptomics, and cytokine analysis to profile virus-specific CD8+ T cells recognizing the ubiquitous pathogens influenza and cytomegalovirus. Our results reveal that virus specificity determines overall magnitude, tissue distribution, differentiation, and clonal repertoire of virus-specific T cells. Age and sex influence T cell differentiation and dissemination in tissues, while T cell tissue residence and functionality are highly correlated with the site. Together, our results demonstrate how the covariates of virus, tissue, age, and sex impact the anti-viral immune response, which is important for targeting, monitoring, and predicting immune responses to existing and emerging viruses.
Neuronal Firing Pattern Modulation

Neurons generate diverse patterns of action potentials, depending on the intrinsic electrical properties of the neurons and on synaptic inputs from other neurons. The firing pattern of a neuron can be regulated, often by neurotransmitters acting via G protein-coupled receptors to modulate voltage-dependent ion channels. Keywords: action potential; bursting; adaptation; ion channel; neurotransmitter
Atracurium after an anticholinesterase. Does prior reversal with edrophonium or neostigmine influence the response to atracurium

This study documents the response to atracurium (75 micrograms.kg-1) administered 30 min after a pancuronium- or tubocurarine-induced neuromuscular block has been reversed with either neostigmine (50 micrograms.kg-1) or edrophonium (0.5 mg.kg-1). Twenty-one ASA 1 or 2 patients were studied, of whom 11 received neostigmine and 10 edrophonium. The degree of neuromuscular block was measured electromyographically from the first dorsal interosseous muscle of the hand using train-of-four stimulation of the ulnar nerve. When atracrium was administered, the single twitch response compared with control was 100% in all patients and the mean train-of-four ratios were 91% and 65% in the neostigmine and edrophonium groups respectively. After atracurium (75 micrograms.kg-1), minimum values for the single twitch response compared with control were 52% and 66% in the neostigmine and edrophonium groups respectively. Prior administration of atracurium appears to potentiate the neuromuscular blocking effects of atracurium administered 30 min later.
Static Analysis to Identify Invariants in RSML Specifications

Static analysis of formal, high-level specifications of safety critical software can discover flaws in the specification that would escape conventional syntactic and semantic analysis. As an example, specifications written in the Requirements State Machine Language (RSML) should be checked for consistency: two transitions out of the same state that are triggered by the same event should have mutually exclusive guarding conditions. The check uses only behavioral information that is local to a small set of states and transitions.
Practice Research Networks

Practice research networks (PRNs) are infrastructures that allow for the collaboration of researchers and clinicians in conducting clinically meaningful and scientifically rigorous research. Despite the variety of PRNs, they can be broadly grouped into three clusters: (a) PRNs sponsored by professional organizations, such as American Psychiatric Association or American Psychological Association; (b) specific disorders PRNS, which conduct studies focused on particular clinical problems such as substance abuse, disruptive behavioral problems in children, child maltreatment, eating disorders and autism; and (c) common clinical settings PRNs, which are based in specific clinical environments, such as counseling centers. Keywords: naturalistic research; practice research network; psychotherapy
Effect of washing and sodium chloride on mechanical properties of fish muscle gels

Excellent gels, as measured by fold test, were prepared from three species of fish without washing if NaCl were added. Dependent on species, excellent to adequate gels could be prepared from fish muscle without NaCl, provided that the minced tissue was washed prior to gel formation. Red hake formed an excellent gel, cod formed a good gel, and flounder formed a fair gel in the absence of NaCl, as judged by fold scores of 5, 4, and 3, respectively.
Anaphylaxis to African finger millet with exercise as a possible co-factor.

The following case report describes the rare occurrence of anaphylaxis to African finger millet with exercise as a possible co-factor. An young adult with no pets nor background history of atopic disease, consumed for the first time a Sri Lankan pancake made from “kurakkan flour”, coconut and sugar. The patient then undertook a strenuous walk, following which he developed anaphylaxis requiring emergency treatment with Adrenaline, nebulised Salbutamol, corticosteroids and antihistamines. On subsequent review, the patient reported no further reactions and had reintroduced coconut into their diet. They had not ingested any further “kurakkan flour”, but continued with a regular and intensive exercise regimen with no clinical reactions. Skin prick tests demonstrated sensitisation to dustmite and grass pollens; common food allergens tested were all negative. A preparation of the implicated flour mixed with saline into a thin paste was used for skin testing and the patient demonstrated a 6 x 6mm positive reaction. Three healthy volunteers tested negative to the same preparation. Kurakkan flour is prepared from African finger millet and is commonly used in Sri Lankan cooking. Anaphylaxis to millet was first described in 1981,[1] however a limited number of case reports suggests this is a rare reaction. More recent publications describe hypersensitivity in bird keepers with sensitisation occurring via inhalational exposure to millet in birdseed.[2] Millet sensitisation has been demonstrated in bird keepers both with and without a history of clinical reactivity.[3] Cross reactivity between rice and millet species can occur secondary to sensitisation to a 16kD allergen in rice grains.[4] Notably, the major prolamin in millet is panicin, which has not been shown to demonstrate cross-reactivity with omega-5-gliadin, the allergenic wheat prolamin implicated in wheat-dependent exercise-induced anaphylaxis. Although cases of millet anaphylaxis have been described with no prior history of sensitisation,[5,6] this is the first report describing millet anaphylaxis with exercise as a possible co-factor. Whilst millet is not a commonly used food, the growing popularity of gluten-free and “natural” diets may result in an increasing frequency of clinical reactivity in Western populations.
Uncharged isocoumarin-based inhibitors of urokinase-type plasminogen activator

Urokinase-type plasminogen activator (uPA) plays a major role in extracellular proteolytic events associated with tumor cell growth, migration and angiogenesis. Consequently, uPA is an attractive target for the development of small molecule active site inhibitors. Most of the recent drug development programs aimed at nonpeptidic inhibitors targeted at uPA have focused on arginino mimetics containing amidine or guanidine functional groups attached to aromatic or heterocyclic scaffolds. There is a general problem of limited bioavailability of these charged inhibitors. In the present study, uPA inhibitors were designed on an isocoumarin scaffold containing uncharged substituents. 4-Chloro-3-alkoxyisocoumarins were synthesized in which the 3-alkoxy group contained a terminal bromine; these were compared with similar inhibitors that contained a charged terminal functional group. Additional variations included functional groups attached to the seven position of the isocoumarin scaffold. N- [3-(3-Bromopropoxy)-4-chloro-1-oxo-1H-isochromen-7-yl]benzamide was identified as an uncharged lead inhibitor of uPA, Ki = 0.034 μM. Molecular modeling of human uPA with these uncharged inhibitors suggests that the bromine occupies the same position as positively charged arginino mimetic groups. This study demonstrates that potent uncharged inhibitors of uPA can be developed based upon the isocoumarin scaffold. A tethered bromine in the three position and an aromatic group in the seven position are important contributors to binding. Although the aim was to develop compounds that act as mechanism-based inactivators, these inhibitors are competitive reversible inhibitors.
PVC‐Induced Second Tachycardia

No abstract available Keywords: AV node reentry; AV reentry; catheter ablation; maneuvers.
New conformationally constrained polyaza macrocycles prepared via the bis(chloroacetamide) method

Abstract The synthesis of two new series of conformationally constrained polyazamacrocycles featuring polysubstitution at macrocycle ring carbons is described.
Western frontal fault of the Canyon Range: Is it the breakaway zone of the Sevier Desert detachment?

Geologic evidence developed from surface exposures demonstrates that the western frontal fault of the Canyon Range is a major structure representing the eastern breakaway zone of the Sevier Desert detachment. The western frontal fault of the Canyon Range east of Delta, Utah, is a north-trending, west-dipping, low-angle (18 °–24 ° ) normal fault that juxtaposes syntectonic conglomerates and large-rock avalanches of the Miocene Oak City Formation against footwall rocks that have been ductilely, cataclastically, and brittlely deformed. The Oak City strata dip variably to the east; dips are shallow in eastern outcrops (5 ° –15 ° ), steeper in central outcrops (20 ° –60 ° ), and shallow in the western outcrops (10 ° –20 ° ). In eastern exposures, the shallow dips of the Oak City Formation (5 ° –15 ° ) and the acute angle of 20 ° –35 ° between the western frontal fault and Oak City units limit past rotation of the fault to ≤15 ° . The systematic variation in the dip of Oak City units from east to west suggests that the western frontal fault probably flattens beneath present Oak City outcrops, linking the fault to the shallow reflector seen in the COCORP (Consortium for Continental Reflection Profiling) Utah line 1 seismic line beneath the westernmost outcrops of the Oak City Formation. Upper plate movement is constrained by Oak City clast compositions and rock-avalanche lithologies, fault geometry, and lower plate reconstruction to a maximum of 6–7 km since Oak City syntectonic deposition at ∼12–13 Ma. Maximum upper plate displacement for the entire Sevier Desert detachment cannot be determined from these breakaway-zone exposures.
Single-shot diffusion-weighted trace imaging on a clinical scanner

The single-shot trace-weighted acquisition scheme for isotro-pic diffusion imaging suggested by Mori and van Zijl Magn. Reson. Med. 33, 41–52 (1995) was implemented on a clinical scanner in combination with echo-planar imaging. The results on phantoms and seven volunteers show that good-quality multiplanar isotropic diffusion-weighted images can be obtained within seconds and absolute Dav images within 10–40 s, depending on the number of gradient strengths used. However, care has to be taken in using this type of multi-bipolar-gradient sequence to avoid measurement of artifactual diffusion constants due to background gradient interference. It is outlined how to test for this interference and how to optimize for the correct experiment.
Stratigraphy and tephra of the Kibish Formation, southwestern Ethiopia.

Abstract The Kibish Formation in southwestern Ethiopia, with an aggregate thickness of ~105 m, consists of lacustrine, marginal lacustrine, and deltaic deposits. It is divided into four members numbered I to IV on the basis of erosion surfaces (disconformities) between the strata of each member. It overlies the Mursi and Nkalabong formations, the latter of which is here shown to correlate with the Shungura Formation. Tephra layers in each member allow for secure correlation between geographically separated sections on the basis of the composition of their volcanic glass. Members I, III, and IV of the Kibish Formation appear to have been deposited at the same times as sapropels S7 (197 ka), S4 (104 ka), and S1 (8 ka) in the eastern Mediterranean Sea, respectively. We correlate the KHS Tuff of the Kibish Formation with a >154-kyr-old unnamed tuff in the Konso Formation. Tephra in Member IV may derive from Mount Wenchi, a volcano situated on the divide between the Omo and Blue Nile drainage basins. Thin-bedded sedimentary layers probably represent annual deposition reflecting rapid sedimentation (~30 m/kyr) of parts of the formation. This conclusion is supported by variation in paleomagnetic inclination through a sequence of these layers at KHS. Two fossils of early Homo sapiens (Omo I and Omo II) derive from Member I. Their stratigraphic placement is confirmed by analysis of the KHS Tuff in the lower part of Member II at both fossil sites. The KHS Tuff lies above a disconformity, which itself lies above the fossils at both sites. 40Ar/39Ar dates provide an estimated age of ~195 kyr for these fossils. Omo III, a third fossil H. sapiens, probably also derives from Member I of the Kibish Formation and is of similar age. Hominin fossils from AHS, a new site, also derive from Member I. Hominin fossils from CHS can only be placed between 104 ka and 10 ka, the H. sapiens specimen from JHS is most likely 9–13 kyr in age, and a partial skeleton of H. sapiens from Pelvic Corner is most likely ~6.6 kyr in age.
Development of compact half-Sierpinski fractal antenna for RFID applications

A compact half-Sierpinski fractal antenna is presented for UHF RFID applications. Taking the thickness of the substrate (177 µm) and compactness (length: width <2∶1) as constraints, the fractal antenna was studied for the highest exhibited gain. A gain close to 0 dBi (−0.64 dBi) with a return loss of less than −10 dB at 915 MHz was observed.
Magnetic Design of the Advanced Light Source Harmonic Sextupoles

Forty-eight harmonic sextupole magnets with integrated dipole correctors and skew quadrupole coils will be introduced in the Advanced Light Source Storage Ring. These new magnets are required to allow the ALS to provide the 40 beamline users with higher photon beam brightness (factor of 2 or 3). Introducing new combined-function magnets in an existing storage ring is a challenge due to the limited space available and a balance had to be found between magnet performance and spatial constraints. Consequently four different magnet designs were required. The calculation and simulation results obtained for each design as well as the impact of the different design choices on the magnetic performance are developed in this paper.
The voltage gates of connexin channels are sensitive to CO2

Cx45 channel sensitivity to CO(2), transjunctional voltage (V(j)) and inhibition of calmodulin (CaM) expression was tested in oocytes by dual voltage-clamp. Cx45 channels are very sensitive to V(j) and close preferentially by the slow gate, likely the same as the chemical gate. With CO(2)-induced drop in junctional conductance (G(j)), the speed of V(j)-dependent inactivation of junctional current (I(j)) and V(j) sensitivity increased. With 40 mV V(j), the tau of single exponential I(j) decay reversibly decreased by approximately 40% with CO(2), and G(j steady state)/G(j peak) decreased multiphasically, indicating that kinetics and V(j) sensitivity of chemical/slow-V(j) gating are altered by changes in [H(+)](i) and/or [Ca(2+)](i). With 15 min exposure to CO(2), G(j) dropped to 0% in controls and by approximately 17% following CaM expression inhibition; similarly, V(j) sensitivity decreased significantly. This indicates that the speed and sensitivity of V(j)-dependent inactivation of Cx45 channels are increased by CO(2), and that CaM plays a role in gating. Cx32 channels behaved similarly, but the drop in both G(j steady state)/G(j peak) and tau with CO(2) matched more closely that of G(j peak). In contrast, sensitivity and speed of V(j) gating of Cx40 and Cx26 channels decreased, rather than increased, with CO(2) application.
A solid-state 199Hg NMR study of mercury halides

Abstract The principal elements of the 199 Hg chemical-shift (CS) tensors of the mercuric halides (HgX 2 , X = F, Cl, Br, and I) and the mercurous halides (Hg 2 X 2 , X = F and Cl) were determined from spectra of static polycrystalline powders and from magic-angle spinning (MAS) spectra. The CS tensors of both HgCl 2 and Hg 2 Cl 2 are axially symmetric ( η = 0) within experimental error, differing from literature reports of η = 0.12 and η = 0.14, respectively. The principal elements of the axially symmetric CS tensor in HgBr 2 were also measured using a static sample, and the wideline spectra of HgF 2 and HgI 2 (red polymorph) give chemical-shift tensors that suggest, within experimental error, that the mercury sits in sites of cubic symmetry. The 199 Hg CS tensor for Hg 2 F 2 is asymmetric. Experiments with static polycrystalline samples may allow the determination of the elements of the 199 Hg CS tensors even when MAS fails to completely average the dipolar coupling of the spin-½ 199 Hg and the quadrupolar halide nucleus.