cssi/SciSciGPT-SciSciNet huggingface dataset:
A computational examination of the two-streams hypothesis: which pathway needs a longer memory?

The two visual streams hypothesis is a robust example of neural functional specialization that has inspired countless studies over the past four decades. According to one prominent version of the theory, the fundamental goal of the dorsal visual pathway is the transformation of retinal information for visually-guided motor behavior. To that end, the dorsal stream processes input using absolute (or veridical) metrics only when the movement is initiated, necessitating very little, or no, memory. Conversely, because the ventral visual pathway does not involve motor behavior (its output does not influence the real world), the ventral stream processes input using relative (or illusory) metrics and can accumulate or integrate sensory evidence over long time constants, which provides a substantial capacity for memory. In this study, we tested these relations between functional specialization, processing metrics, and memory by training identical recurrent neural networks to perform either a viewpoint-invariant object classification task or an orientation/size determination task. The former task relies on relative metrics, benefits from accumulating sensory evidence, and is usually attributed to the ventral stream. The latter task relies on absolute metrics, can be computed accurately in the moment, and is usually attributed to the dorsal stream. To quantify the amount of memory required for each task, we chose two types of neural network models. Using a long-short-term memory (LSTM) recurrent network, we found that viewpoint-invariant object categorization (object task) required a longer memory than orientation/size determination (orientation task). Additionally, to dissect this memory effect, we considered factors that contributed to longer memory in object tasks. First, we used two different sets of objects, one with self-occlusion of features and one without. Second, we defined object classes either strictly by visual feature similarity or (more liberally) by semantic label. The models required greater memory when features were self-occluded and when object classes were defined by visual feature similarity, showing that self-occlusion and visual similarity among object task samples are contributing to having a long memory. The same set of tasks modeled using modified leaky-integrator echo state recurrent networks (LiESN), however, did not replicate the results, except under some conditions. This may be because LiESNs cannot perform fine-grained memory adjustments due to their network-wide memory coefficient and fixed recurrent weights. In sum, the LSTM simulations suggest that longer memory is advantageous for performing viewpoint-invariant object classification (a putative ventral stream function) because it allows for interpolation of features across viewpoints. The results further suggest that orientation/size determination (a putative dorsal stream function) does not benefit from longer memory. These findings are consistent with the two visual streams theory of functional specialization.
Designing Personalized Treatment Plans for Breast Cancer

Breast cancer remains the leading cause of cancer deaths among women around the world. Contemporary treatment for breast cancer is complex and involves highly specialized medical professionals coll...
International Coordination of Macroprudential Policies with Capital Flows and Financial Asymmetries

Abstract Lack of coordination for prudential regulation hurts developing economies but benefits advanced economies. We consider a two-country macro model in which countries have limited ability to issue state-contingent contracts in international markets, and equilibrium is constrained inefficient. Both countries have incentives to stabilize their economy by using prudential limits, but the emerging economy depends on the advanced economy to bear global risk. Intermediating global risk requires bearing systemic risk, which financially developed economies are unwilling to bear, preferring financial stability over credit flows. Advanced economies prefer tighter prudential limits than would occur with coordination, to the harm of emerging economies.
Equations Defining Secant Varieties: Geometry and Computation

In the 1980’s, work of Green and Lazarsfeld (Invent. Math., 83, 1 (1985), 73–90; Compositio Math., 67, 3 (1988), 301–314), helped to uncover the beautiful interplay between the geometry of the embedding of a curve and the syzygies of its defining equations. Similar results hold for the first secant variety of a curve, and there is a natural conjectural picture extending to higher secant varieties as well. We present an introduction to the algebra and geometry used in (Sidman and Vermeire, Algebra Number Theory, 3, 4 (2009), 445–465) to study syzygies of secant varieties of curves with an emphasis on examples of explicit computations and elementary cases that illustrate the geometric principles at work.
Machine Learning of Interstellar Chemical Inventories

The characterization of interstellar chemical inventories provides valuable insight into the chemical and physical processes in astrophysical sources. The discovery of new interstellar molecules becomes increasingly difficult as the number of viable species grows combinatorially, even when considering only the most thermodynamically stable. In this work, we present a novel approach for understanding and modeling interstellar chemical inventories by combining methodologies from cheminformatics and machine learning. Using multidimensional vector representations of molecules obtained through unsupervised machine learning, we show that identification of candidates for astrochemical study can be achieved through quantitative measures of chemical similarity in this vector space, highlighting molecules that are most similar to those already known in the interstellar medium. Furthermore, we show that simple, supervised learning regressors are capable of reproducing the abundances of entire chemical inventories, and predict the abundance of not yet seen molecules. As a proof-of-concept, we have developed and applied this discovery pipeline to the chemical inventory of a well-known dark molecular cloud, the Taurus Molecular Cloud 1 (TMC-1); one of the most chemically rich regions of space known to date. In this paper, we discuss the implications and new insights machine learning explorations of chemical space can provide in astrochemistry.
A Metric For Evaluating 3d Reconstruction And Mapping Performance With No Ground Truthing

It is not easy when evaluating 3D mapping performance because existing metrics require ground truth data that can only be collected with special instruments. In this paper, we propose a metric, dense map posterior (DMP), for this evaluation. It can work without any ground truth data. Instead, it calculates a comparable value, reflecting a map posterior probability, from dense point cloud observations. In our experiments, the proposed DMP is benchmarked against ground truth-based metrics. Results show that DMP can provide a similar evaluation capability. The proposed metric makes evaluating different methods more flexible and opens many new possibilities, such as self-supervised methods and more available datasets.
ESG Disclosure, REIT Debt Financing and Firm Value

Using recently available GRESB ESG public disclosure data for REITs around the world, we examine how ESG disclosure is related to REIT debt financing and firm value. We find that REITs with higher levels of ESG disclosure have lower cost of debt, higher credit ratings, and higher unsecured debt to total debt ratio, controlling for key firm characteristics. These findings suggest that improving ESG disclosure can help REITs to gain better access to the capital markets and enhance corporate financial flexibility, as lenders have paid close attention to a firm’s ESG disclosure and integrated evaluation of ESG factors into their lending decisions. Moreover, firm value of REITs is positively associated with their ESG disclosure level. When using the Covid-19 pandemic as a quasi-experimental setting, we find evidence that REITs with higher ESG disclosure levels before the pandemic exhibit higher firm value during the pandemic. These results indicate that investors do value active ESG disclosure by REITs. Additional analyses show that ESG disclosure level is sensitive to institutional ownership, implying that institutional investors may drive REIT ESG disclosure efforts. Taken together, this paper suggests that effective ESG disclosure can have a positive impact on REIT debt financing and firm value due to the increased corporate transparency, and the ESG reporting framework developed by GRESB appears to be effective to provide transparency and comparability across the global real estate industry.
On Hecke eigenvalues of cusp forms in almost all short intervals

Let ψ be a function such that ψ(x) →∞ as x →∞. Let λf(n) be the nth Hecke eigenvalue of a fixed holomorphic cusp form f for SL(2, ℤ). We show that for any real-valued function h(x) such that (log X...
Dark Energy Survey's Observation Strategy, Tactics, and Exposure Scheduler

The Dark Energy Survey is a stage III dark energy experiment, performing an optical imaging survey to measure cosmological equation of state parameters using four independent methods. The scope and complexity of the survey introduced complex strategic and tactical scheduling problems that needed to be addressed. We begin with an overview of the process used to develop DES strategy and tactics, from the inception of the project, to task forces that studied and developed strategy changes over the course of the survey, to the nightly pre-observing meeting in which immediate tactical issues were addressed. We then summarize the strategic choices made for each sub-survey, including metrics, scheduling considerations, choice of time domain fields and their sequences of exposures, and wide survey footprint and pointing layout choices. We go on to describe the detailed process that determined which specific exposures were taken at which specific times. We give a chronology of the strategic and tactical peculiarities of each year of observing, including the proposal and execution of a sixth year. We give an overview of obstac, the implementation of the DES scheduler used to simulate and evaluate strategic and tactical options, and automate exposure scheduling; and describe developments in obstac for use after DES. Appendices describe further details of data quality evaluation, tau, and t_eff; airmass calculation; and modeling of the seeing and sky brightness. The significant corpus of DES data indicates that the simple scaling relations for seeing as a function of wavelength and airmass derived from the Kolmogorov turbulence model work adequately for exposure planning purposes: deviations from these relations are modest in comparison with short time-scale seeing variations.
What is A Wireless UAV?: A Design Blueprint for 6G Flying Wireless Nodes

Wireless Unmanned Aerial Vehicles (UAVs) were introduced in the world of 4th generation networks (4G) as cellular users, and have attracted the interest of the wireless community ever since. In 5G, UAVs operate also as flying Base Stations providing service to ground users. They can also implement independent off-the-grid UAV networks. In 6G networks, wireless UAVs will connect ground users to in-orbit wireless infrastructure. As the design and prototyping of wireless UAVs are on the rise, the time is ripe for introducing a more precise definition of what is a wireless UAV. In doing so, we revise the major design challenges in the prototyping of wireless UAVs for future 6G spectrum research. We then introduce a new wireless UAV prototype that addresses these challenges. The design of our wireless UAV prototype will be made public and freely available to other researchers.
Learning Sampling Distributions Using Local 3D Workspace Decompositions for Motion Planning in High Dimensions

Earlier work has shown that reusing experience from prior motion planning problems can improve the efficiency of similar, future motion planning queries. However, for robots with many degrees-of-freedom, these methods exhibit poor generalization across different environments and often require large datasets that are impractical to gather. We present SPARK and FLAME, two experience-based frameworks for sampling-based planning applicable to complex manipulators in 3D environments. Both combine samplers associated with features from a workspace decomposition into a global biased sampling distribution. SPARK decomposes the environment based on exact geometry while FLAME is more general, and uses an octree-based decomposition obtained from sensor data. We demonstrate the effectiveness of SPARK and FLAME on a real and simulated Fetch robot tasked with challenging pick-and-place manipulation problems. Our approaches can be trained incrementally and significantly improve performance with only a handful of examples, generalizing better over diverse tasks and environments as compared to prior approaches.
Evidence for a Liquid Precursor to Biomineral Formation

The crystals in animal biominerals such as sea urchin spines, mollusk shells, and coral skeletons, form by attachment of amorphous particles that subsequently crystallize. Do these solid amorphous precursor particles have liquid precursors? Polymer-induced liquid precursors (PILP), or prenucleation clusters coalescing into a liquid precursor to calcium carbonate crystallization have been observed extensively in synthetic systems. Molecular dynamics simulations also predict liquid-liquid phase separation. However, evidence for liquid precursors in natural biominerals remains elusive. Here we present Scanning or PhotoEmission Electron Microscopy (SEM, PEEM) evidence consistent with a dense liquid-like precursor in regenerating sea urchin spines. The observed precursor originates in tissue and ultimately transforms into a single crystal of calcite (CaCO3) with complex stereom morphology.
Unexpected inverse correlations and cooperativity in ion-pair phase transfer.

Liquid/liquid extraction is one of the most widely used separation and purification methods, where a forefront of research is the study of transport mechanisms for solute partitioning and the relationships that these have to solution structure at the phase boundary. To date, organized surface features that include protrusions, water-fingers, and molecular hinges have been reported. Many of these equilibrium studies have focused upon small-molecule transport – yet the extent to which the complexity of the solute, and the competition between different solutes, influence transport mechanisms have not been explored. Here we report molecular dynamics simulations that demonstrate that a metal salt (LiNO3) can be transported via a protrusion mechanism that is remarkably similar to that reported for H2O by tri-butyl phosphate (TBP), a process that involves dimeric assemblies. Yet the LiNO3 out-competes H2O for a bridging position between the extracting TBP dimer, which in-turn changes the preferred transport pathway of H2O. Examining the electrolyte concentration dependence on ion-pair transport unexpectedly reveals an inverse correlation with the extracting surfactant concentration. As [LiNO3] increases, surface adsorbed TBP becomes a limiting reactant in correlation with an increased negative surface charge induced by excess interfacial NO3−, however the rate of transport is enhanced. Within the highly dynamic interfacial environment, we hypothesize that this unique cooperative effect may be due to perturbed surface organization that either decreases the energy of formation of transporting protrusion motifs or makes it easier for these self-assembled species to disengage from the surface.
Peripheral Artery Disease and COVID-19 Outcomes: Insights from the Yale DOM-CovX Registry.

Background Both COVID-19 infection and peripheral arterial disease (PAD) cause hypercoagulability in patients, and it remains unknown whether PAD predisposes patients to experience worse outcomes when infected with SARS-CoV-2. Methods The Yale DOM-CovX Registry consecutively enrolled inpatients for SARS-CoV-2 between March 1, 2020, and November 10, 2020. Adjusted logistic regression models examined associations between PAD and mortality, stroke, myocardial infarction (MI), and major adverse cardiovascular events (MACE, all endpoints combined). Results Of the 3,830 patients were admitted with SARS-CoV-2, 50.5% were female, mean age was 63.1 ±18.4 years, 50.7% were minority race, and 18.3% (n = 693) had PAD. PAD was independently associated with increased mortality (OR=1.45, 95% CI 1.11-1.88) and MACE (OR=1.48, 95% CI 1.16-1.87). PAD was not independently associated with stroke (p=0.06) and MI (p=0.22). Conclusion Patients with PAD have a >40% odds of mortality and MACE when admitted with a SARS-CoV-2, independent of known risk factors.
Scenario Analysis with the DD-PD Mapping Approach: Stock Market Shocks and U.S. Corporate Default Risk

This paper introduces the quantile regression- based Distance-to-Default to Probability of Default (DD-PD) mapping, which links individual firms’ DD to their real world PD. Since changes in the DD depend on a handful of parameters, the mapping easily accommodates shocks arising from quantitative and narrative scenarios informed by expert judgment. At end-2020, risks from stock market corrections in the U.S. are concentrated in the energy, financial and technology sectors, and additional bank capital needs could be large. The paper concludes discussing uses of the mapping beyond PD valuation suitable for capital structure analysis, credit portfolio management, and long-term scenario planning analysis.
Circumventing the optical diffraction limit using customized speckles

We design and create special speckle patterns for parallelized nonlinear pattern-illumination microscopy based on fluorescence photoswitching. In a proof-of-principle experimental demonstration, we obtain a spatial resolution three times higher than the diffrac-tion limit.
Bacterial community dynamics during embryonic development of the little skate (Leucoraja erinacea).

BACKGROUND Microbial transmission from parent to offspring is hypothesized to be widespread in vertebrates. However, evidence for this is limited as many evolutionarily important clades remain unexamined. There is currently no data on the microbiota associated with any Chondrichthyan species during embryonic development, despite the global distribution, ecological importance, and phylogenetic position of this clade. In this study, we take the first steps towards filling this gap by investigating the microbiota associated with embryonic development in the little skate, Leucoraja erinacea, a common North Atlantic species and popular system for chondrichthyan biology. METHODS To assess the potential for bacterial transmission in an oviparous chondrichthyan, we used 16S rRNA amplicon sequencing to characterize the microbial communities associated with the skin, gill, and egg capsule of the little skate, at six points during ontogeny. Community composition was analyzed using the QIIME2 pipeline and microbial continuity between stages was tracked using FEAST. RESULTS We identify site-specific and stage-specific microbiota dominated by the bacterial phyla Proteobacteria and Bacteroidetes. This composition is similar to, but distinct from, that of previously published data on the adult microbiota of other chondrichthyan species. Our data reveal that the skate egg capsule harbors a highly diverse bacterial community-particularly on the internal surface of the capsule-and facilitates intergenerational microbial transfer to the offspring. Embryonic skin and external gill tissues host similar bacterial communities; the skin and gill communities later diverge as the internal gills and skin denticles develop. CONCLUSIONS Our study is the first exploration of the chondrichthyan microbiota throughout ontogeny and provides the first evidence of vertical transmission in this group.
Detecting and Segmenting Adversarial Graphics Patterns From Images

Adversarial attacks pose a substantial threat to computer vision system security, but the social media industry constantly faces another form of "adversarial attack" in which the hackers attempt to upload inappropriate images and fool the automated screening systems by adding artificial graphics patterns. In this paper, we formulate the defense against such attacks as an artificial graphics pattern segmentation problem. We evaluate the efficacy of several segmentation algorithms and, based on observation of their performance, propose a new method tailored to this specific problem. Extensive experiments show that the proposed method outperforms the baselines and has a promising generalization capability, which is the most crucial aspect in segmenting artificial graphics patterns.
Bose-Einstein statistics for a finite number of particles

This paper presents a study of the grand canonical Bose-Einstein (BE) statistics for a finite number of particles in an arbitrary quantum system. The thermodynamical quantities that identify BE condensation---namely, the fraction of particles in the ground state and the specific heat---are calculated here exactly in terms of temperature and fugacity. These calculations are complemented by a numerical calculation of fugacity in terms of the number of particles, without taking the thermodynamic limit. The main advantage of this approach is that it does not rely on approximations made in the vicinity of the usually defined critical temperature, rather it makes calculations with arbitrary precision possible, irrespective of temperature. Graphs for the calculated thermodynamical quantities are presented in comparison to the results previously obtained in the thermodynamic limit. In particular, it is observed that for the gas trapped in a three-dimensional box, the derivative of specific heat reaches smaller values than what was expected in the thermodynamic limit---here, this result is also verified with analytical calculations. This is an important result for understanding the role of the thermodynamic limit in phase transitions and makes possible to further study BE statistics without relying neither on the thermodynamic limit nor on approximations near critical temperature.
Social Norms in Fourth Amendment Law

Courts often look to existing social norms to resolve difficult questions in Fourth Amendment law. In theory, these norms can provide an objective basis for courts’ constitutional decisions, grounding Fourth Amendment law in familiar societal attitudes and beliefs. In reality, however, social norms can shift rapidly, are constantly being contested, and frequently reflect outmoded and discriminatory concepts. This Article draws on contemporary sociological literatures on norms and technology to reveal how courts’ reliance on norms leads to several identifiable errors in Fourth Amendment jurisprudence. Courts assessing social norms generally adopt what we call the closure principle, or the idea that social norms can be permanently settled. Meanwhile, courts confronting new technologies often adopt the nonintervention principle, or the idea that courts should refrain from addressing the Fourth Amendment implications of new surveillance practices until the relevant social norms become clear. Both of these approaches are flawed, and they have substantial negative effects for equality and privacy. By adopting norms perceived as closed, courts may embed antiquated norms in Fourth Amendment law—norms that often involve discrimination on the basis of race, gender, or class. By declining to intervene when norms are undeveloped, courts cede power over norm creation to companies that design new technologies based on data-extractive business models. Further, judicial norm-reliance and nonintervention facilitate surveillance creep, where familiar data-gathering infrastructures are used for new types of surveillance and monitoring. This Article provides, for the first time, a full, critical account of the role of social norms in Fourth Amendment law. It details and challenges courts’ reliance on social norms in virtually every aspect of Fourth Amendment jurisprudence. And it explores potential new directions for Fourth Amendment law, including novel doctrinal paradigms, different conceptions of stare decisis in the Fourth Amendment context, and alternative institutional regimes for regulating government surveillance.
Deep Learning Enabled Assessment of Magnetic Confinement in Magnetized Liner Inertial Fusion

Magnetized Liner Inertial Fusion (MagLIF) is a magneto-inertial fusion (MIF) concept being studied on the Z-machine at Sandia National Laboratories. MagLIF relies on quasi-adiabatic heating of a gaseous deuterium (DD) fuel and flux compression of a background axially oriented magnetic field to achieve fusion relevant plasma conditions. The magnetic flux per fuel radial extent determines the confinement of charged fusion products and is thus of fundamental interest in understanding MagLIF performance. It was recently shown that secondary DT neutron spectra and yields are sensitive to the magnetic field conditions within the fuel, and thus provide a means by which to characterize the magnetic confinement properties of the fuel. 1 , 2 , 3 We utilize an artificial neural network to surrogate the physics model of Refs. [1] , [2] , enabling Bayesian inference of the magnetic confinement parameter for a series of MagLIF experiments that systematically vary the laser preheat energy deposited in the target. This constitutes the first ever systematic experimental study of the magnetic confinement properties as a function of fundamental inputs on any neutron-producing MIF platform. We demonstrate that the fuel magnetization decreases with deposited preheat energy in a fashion consistent with Nernst advection of the magnetic field out of the hot fuel and diffusion into the target liner.
DetectorGuard: Provably Securing Object Detectors against Localized Patch Hiding Attacks

State-of-the-art object detectors are vulnerable to localized patch hiding attacks, where an adversary introduces a small adversarial patch to make detectors miss the detection of salient objects. The patch attacker can carry out a physical-world attack by printing and attaching an adversarial patch to the victim object; thus, it imposes a challenge for the safe deployment of object detectors. In this paper, we propose DetectorGuard as the first general framework for building provably robust object detectors against localized patch hiding attacks. DetectorGuard is inspired by recent advancements in robust image classification research; we ask: can we adapt robust image classifiers for robust object detection? Unfortunately, due to their task difference, an object detector naively adapted from a robust image classifier 1) may not necessarily be robust in the adversarial setting or 2) even maintain decent performance in the clean setting. To address these two issues and build a high-performance robust object detector, we propose an objectness explaining strategy: we adapt a robust image classifier to predict objectness (i.e., the probability of an object being present) for every image location and then explain each objectness using the bounding boxes predicted by a conventional object detector. If all objectness is well explained, we output the predictions made by the conventional object detector; otherwise, we issue an attack alert. Notably, our objectness explaining strategy enables provable robustness for "free": 1) in the adversarial setting, we formally prove the end-to-end robustness of DetectorGuard on certified objects, i.e., it either detects the object or triggers an alert, against any patch hiding attacker within our threat model; 2) in the clean setting, we have almost the same performance as state-of-the-art object detectors. Our evaluation on the PASCAL VOC, MS COCO, and KITTI datasets further demonstrates that DetectorGuard achieves the first provable robustness against localized patch hiding attacks at a negligible cost (
Reverse engineering recurrent neural networks with Jacobian switching linear dynamical systems

Recurrent neural networks (RNNs) are powerful models for processing time-series data, but it remains challenging to understand how they function. Improving this understanding is of substantial interest to both the machine learning and neuroscience communities. The framework of reverse engineering a trained RNN by linearizing around its fixed points has provided insight, but the approach has significant challenges. These include difficulty choosing which fixed point to expand around when studying RNN dynamics and error accumulation when reconstructing the nonlinear dynamics with the linearized dynamics. We present a new model that overcomes these limitations by co-training an RNN with a novel switching linear dynamical system (SLDS) formulation. A first-order Taylor series expansion of the co-trained RNN and an auxiliary function trained to pick out the RNN's fixed points govern the SLDS dynamics. The results are a trained SLDS variant that closely approximates the RNN, an auxiliary function that can produce a fixed point for each point in state-space, and a trained nonlinear RNN whose dynamics have been regularized such that its first-order terms perform the computation, if possible. This model removes the post-training fixed point optimization and allows us to unambiguously study the learned dynamics of the SLDS at any point in state-space. It also generalizes SLDS models to continuous manifolds of switching points while sharing parameters across switches. We validate the utility of the model on two synthetic tasks relevant to previous work reverse engineering RNNs. We then show that our model can be used as a drop-in in more complex architectures, such as LFADS, and apply this LFADS hybrid to analyze single-trial spiking activity from the motor system of a non-human primate.
Lagrange spectrum of a circle over the Eisensteinian field

We study an intrinsic Lagrange spectrum of the unit circle $$|z|=1$$ in the complex plane with respect to the Eisensteinian field $${\mathbb {Q}}(\sqrt{-3})$$ . We prove that the minimum of the Lagrange spectrum is 2 and that its smallest accumulation point is $$4/\sqrt{3}$$ . In addition, we characterize the set of all values in the spectrum between 2 and $$4/\sqrt{3}$$ .
Modular Invariant Theory

In this chapter we discuss the role of classical invariant theory in determining and analyzing the cohomology of finite groups. Typically, one has a subgroup of the form H = (ℤ/p)n ⊂ G and we note that $$im\left( {res*:H*\left( {G;{F_p}} \right) \to H*\left( {H;{F_p}} \right)} \right)$$ is contained in the ring of invariants under the action of N G (H)/H on H*(H;𝔽p), (II.3.1). In some cases, see e.g. (II.6.8), it is possible to describe the entire cohomology ring of G in this way, but more often they contribute important but incomplete portions which are assembled using restriction maps to give the most important pieces of H*(G;𝔽p), see (IV.5).
Cross-Section Measurements for Electron Impact on Excited Atomic Species

Publisher Summary This chapter reviews differential and integral (DCS and Q, respectively) cross-section measurement techniques and available cross-section data for electron collisions with excited neutral atoms. The chapter discusses methods for the production and detection of excited atoms, with emphasis on recent methods that relate to cross-section measurements. A number of improved electron-impact excitation and charge-exchange schemes have been reported in recent years for the production of metastable atoms and with the availability of lasers, it is now also possible to produce large populations in levels with short radiative lifetimes, as well as in metastable levels through cascade processes. The latter method is, however, not yet fully exploited. Quantitative cross-section measurements require the knowledge of excited atom densities (at least relative to ground state species) and, in cases where more than one excited species are present, the relative densities of these species. The methods for determining these densities are described.
Invasion of human coronary artery endothelial cells by Streptococcus mutans OMZ175

Introduction Dissemination of oral bacteria into the bloodstream has been associated with eating, oral hygiene, and dental procedures; including tooth extraction, endodontic treatment, and periodontal surgery. Recently, studies identified Streptococcus mutans, the primary etiological agent of dental caries, as the most prevalent bacterial species found in clinical samples from patients who underwent heart valve and atheromatous plaque surgery.
Shrinkage Measurement in Concrete Materials using Cure Reference Method

This paper describes the details of using Cure Reference Method (CRM) to determine the shrinkage that develops in concrete materials. The technique involves the replication of diffraction grating on the concrete specimen during curing. After demolded, the specimen is stored in a chamber where a specific drying condition is maintained for 6 days. Every day in this period, the specimen is removed from the chamber and a set of the consecutive moire fringe patterns are recorded with the help of a specially-designed stage. An automated fringe analysis program is developed to obtain the full-field displacement and strain information. Shrinkage as a function of location, time, and drying conditions is measured. A numerical method is developed in order to obtain material properties from the complex geometry used in the tests. The test in different drying condition and the ring test are performed, and their results are compared with FEA to validate the constructed model.
Oral health in nursing home residents with different cognitive statuses.

Objective: To compare oral health in nursing home (NH) residents with different cognitive statuses. Background: Oral health is a significant issue for NH residents because of its relationships to quality of life, systemic health and well-being. It is known that oral health is poor in NH residents. However, how oral health differs in NH residents with different cognitive statuses remains unclear. Materials and methods: Nine hundred and two NH residents were retrospectively recruited from a community-based geriatric dental clinic in Minnesota, USA. Comprehensive medical, dental, cognitive and functional assessments were completed for the participants. On the basis of medical history and cognitive status, participants were categorized into three groups: without cognitive impairment (non-impaired group), with cognitive impairment but no dementia (impaired group) and with dementia (demented group). ANOVA, Chi-square and Fisher’s exact tests were used to compare medical, dental and functional statuses between groups. Results: Oral hygiene was poor in NH residents. Forty per cent of participants in the impaired group were edentulous, significantly higher than the edentulism rate in the demented group (29%, p = 0.01). More than 60% of the participants lost 16 or more teeth prior to examination. Depending on their cognitive status, 82–92% of the participants arrived with one or more caries or retained root. Dentate participants in the impaired and demented groups averaged about six caries or retained roots, significantly more than 4.7 caries or retained roots in the non-impaired group (p = 0.01). Conclusion: Oral health was poor but slightly different in NH residents with different cognitive and functional statuses.
Angiotensin-converting enzyme inhibitors in left ventricular dysfunction.

Angiotensin-converting enzyme (ACE) inhibitors have been used for more than a decade in the treatment of chronic congestive heart failure. In recent years these agents have been used in patients who survived a myocardial infarction. However, primary care providers are often confused as to which patients would benefit the most, and as a result, these life-prolonging drugs are underutilized. The results of randomized controlled trials evaluating ACE inhibitors' effects on morbidity and mortality in patients with chronic congestive heart failure or acute myocardial infarction were evaluated. Angiotensin-converting enzyme inhibitors clearly improve survival in patients with symptomatic congestive heart failure. This survival benefit is approximately 6 months. In patients with asymptomatic systolic dysfunction, these agents also decrease the number of hospital admissions due to heart failure. Angiotensin-converting enzyme inhibitors also improve survival in all patients who experienced an acute myocardial infarction. With the plethora of evidence regarding the positive effects that this class of drugs has on the quality of life and survival of patients with systolic dysfunction, it is still unclear why clinicians are reluctant to use them more often. Primary care providers need to be educated on how to risk stratify patients to make this therapy more cost effective, and when these agents should be started.
Concurrent Astronomical Observations for Studying Continental Drift, Polar Motion, and the Rotation of the Earth

The analysis of 66 years of concurrent latitude observations of the ILS shows that the mean pole has a secular motion which consists of a progressive component of about 0′.0035/yr (10 cm/yr) along the meridian 65°W and a librational component (oscillation) of 24-year period along the meridian 122°W (or 58°E). Crustal displacements in latitude are not found within the errors of observation, about 1 cm/yr.
Simulation training for innovation champions

Summary form only given as follows. Encouraging innovative practice in mature, stable, change resisting organizations is a topic of interest. Champions are especially important in mature organizations because routines are well established and there is considerable resistance to innovation due to its routine-disrupting nature. The simulation described here provides training in the champion role.
Sculpting Neural Circuits by Axon and Dendrite Pruning

The assembly of functional neural circuits requires the combined action of progressive and regressive events. Regressive events encompass a variety of inhibitory developmental processes, including axon and dendrite pruning, which facilitate the removal of exuberant neuronal connections. Most axon pruning involves the removal of axons that had already made synaptic connections; thus, axon pruning is tightly associated with synapse elimination. In many instances, these developmental processes are regulated by the interplay between neurons and glial cells that act instructively during neural remodeling. Owing to the importance of axon and dendritic pruning, these remodeling events require precise spatial and temporal control, and this is achieved by a range of distinct molecular mechanisms. Disruption of these mechanisms results in abnormal pruning, which has been linked to brain dysfunction. Therefore, understanding the mechanisms of axon and dendritic pruning will be instrumental in advancing our knowledge...
Freeze-fracture study of changes in nuclei isolated from ischemic rat kidney

Abstract The frequency of nuclear pores/μ 2 in isolated nuclei from ischemic rat kidneys decreased by half after 20 min of occlusion of the blood supply to the kidney. The decrease in pore number remained constant through 120 min ischemia. Particles in the concave fracture face of the outer nuclear membrane changed from a random distribution in control nuclei to a reticular pattern after 20 min ischemia, becoming more sparse and clustered through 120 min ischemia. Deterioration of the pore structure also was noted after 120 min ischemia. It is suggested that these changes are related to loss of nuclear function.
Antitumor Cytotoxicity and Stereochemistry of Polyketides from Goniothalamus amuyon

Abstract An antitumor cytotoxicity-bioassay directed fractionation and separation of the ethanol extract of Goniothalamus amuyon led to the isolation of three highly cytotoxic polyketides, gigantriocin (1), corossolin (2) and annonacin (3) against three human tumor cell lines. The stereochemistry was proposed on the basis of extensive NMR analysis and biogenetic pathways.
ANELASTIC RELAXATION IN IRRADIATED Cu-Be

Mesures de vitesse des ultrasons apres irradiation par des neutrons thermiques sur des echantillons monocristallins de Cu contenant 700 ou 3700 ppm at. de Be. On effectue des mesures semblables sur des echantillons irradies par des electrons. On observe trois processus de relaxation anelastique dus aux complexes Be-autointerstitiels, a tres basse temperature
Engaging Community With Promotores de Salud to Support Infant Nutrition and Breastfeeding Among Latinas Residing in Los Angeles County: Salud con Hyland's

The Salud con Hyland's Project: Comienzo Saludable, Familia Sana [Health With Hyland's Project: Healthy Start, Healthy Family],was developed to provide education and support to Latina mothers regarding healthy infant feeding practices and maternal health. The promotora-delivered intervention was comprised of two charlas (educational sessions) and a supplemental, culturally and linguistically relevant infant feeding and care rolling calendar. Results indicate that the intervention increased intention to breastfeed exclusively, as well as to delay infant initiation of solids by 5 to 6 months. Qualitative feedback identified barriers to maternal and child health education as well as highlighted several benefits of the intervention.
Cross‐B convection of artificially created, negative‐ion clouds and plasma depressions: Low‐speed flow

A negative-ion, positive-ion plasma produced by the release of an electron attachment chemical into the F region becomes electrically polarized by collisions with neutrals moving across magnetic field lines. The resulting electric field causes E x B drift of the two ion species and the residual electrons. The cross-field flow of the modified ionosphere is computed using a two-dimensional numerical simulation which includes electron attachment and mutual neutralization chemistry, self-consistent electric fields, and three-species plasma transport. The velocity of the plasma is initially in the direction of the neutral wind because the negative-ion cloud is a Pedersen conductivity enhancement. As the positive and negative ions react, the Pedersen conductivity becomes depressed below the ambient value and the velocity of the plasma reverses direction. A plasma hole remains after the positive and negative ions have mutually neutralized. The E x B gradient drift instability produces irregularities on the upwind edge of the hole.
The long-term suppression of ventricular arrhythmia by oral acebutolol in patients with coronary artery disease

The short-term efficacy of oral acebutolol was evaluated in 20 patients with coronary artery disease and frequent premature ventricular contractions (PVCs) by serial 24-hour Holter monitoring before and while the patients were receiving an average daily dose of 1,100 mg. of acebutolol for four weeks. Fifty-five percent of the 20 patients showed a greater than 70% PVC reduction from baseline values. The only serious side effect during short-term therapy was mild, reversible cardiac decompensation in one patient. The long-term safety and continued efficacy of acebutolol was then evaluated over the next 11 months in nine of the 11 patients showing greater than 70% PVC reduction at four weeks. Two-thirds of these nine patients continued to show greater than 80% PVC reduction from baseline values at 12 months. One patient developed alopecia during long-term therapy. The majority of patients not responding well to acebutolol at four weeks had an actual increase in PVCs on acebutolol therapy. We conclude that acebutolol produces long-term, effective reduction in PVCs without serious toxicity in the majority of patients with ventricular ectopy. However, this drug appears to either produce an excellent response or no response with regard to PVC control in most instances.
DsbL and DsbI contribute to periplasmic disulfide bond formation in Salmonella enterica serovar Typhimurium

Disulfide bond formation in periplasmic proteins is catalysed by the DsbA/DsbB system in most Gram-negative bacteria. Salmonella enterica serovar Typhimurium also encodes a paralogous pair of proteins to DsbA and DsbB, DsbL and DsbI, respectively, downstream of a periplasmic arylsulfate sulfotransferase (ASST). We show that DsbL and DsbI function as a redox pair contributing to periplasmic disulfide bond formation and, as such, affect transcription of the Salmonella pathogenicity island 1 (SPI1) type three secretion system genes and activation of the RcsCDB system, as well as ASST activity. In contrast to DsbA/DsbB, however, the DsbL/DsbI system cannot catalyse the disulfide bond formation required for flagellar assembly. Phylogenic analysis suggests that the assT dsbL dsbI genes are ancestral in the Enterobacteriaceae, but have been lost in many lineages. Deletion of assT confers no virulence defect during acute Salmonella infection of mice.
Measurements of near-IR water vapor absorption at high pressure and temperature

Tunable diode lasers (TDLs) are used to measure high resolution (0.1 cm-1), near-infrared (NIR) water vapor absorption spectra at 700 K and pressures up to 30 atm within a high-pressure and -temperature optical cell in a high-uniformity tube furnace. Both direct absorption and wavelength modulation with second harmonic detection (WMS-2f) spectra are obtained for 6 cm-1 regions near 7204 cm-1 and 7435 cm-1. Direct absorption measurements at 700 K and 10 atm are compared with simulations using spectral parameters from HITRAN and a hybrid database combining HITRAN with measured spectral constants for transitions in the two target spectral regions. The hybrid database reduces RMS error between the simulation and the measurements by 45% for the 7204 cm-1 region and 28% for the 7435 cm-1 region. At pressures above 10 atm, the breakdown of the impact approximation inherent to the Lorentzian line shape model becomes apparent in the direct absorption spectra, and measured results are in agreement with model results and trends at elevated temperatures reported in the literature. The wavelength-modulation spectra are shown to be less affected by the breakdown of the impact approximation and measurements agree well with the hybrid database predictions to higher pressures (30 atm).
The Effect of Penicillin and Penicillamine on Chick Growth When Injected and When fed Orally

Abstract Elam et al. (1951) reported that growth responses in chicks were obtained by injection of penicillin which had been autoclaved in aqueous solution. They obtained no response when autoclaved penicillin was fed orally. In earlier work with penicillin, Abraham et al. (1942) found that the hydrolysis of penicillin yielded, among other products, an amino acid, penicillamine. Further study showed that all types of penicillin could be hydrolyzed into penicillamine and other products by several different methods (Imperial Industries Report, 1943; Abraham et al, 1943). From these reports it appears that the autoclaved penicillin used by Elam et al. (1951) may have decomposed with the liberation of penicillamine. The purpose of the experiments reported herein was to determine the feeding value of penicillamine. EXPERIMENTAL White Wyandotte chicks were randomly distributed at one week of age into groups of twenty chicks each and maintained in battery brooders with raised wire floors throughou …