cssi/SciSciGPT-SciSciNet huggingface dataset:
Examining characteristics of predictive models with imbalanced big data

High class imbalance between majority and minority classes in datasets can skew the performance of Machine Learning algorithms and bias predictions in favor of the majority (negative) class. This bias, for cases where the minority (positive) class is of greater interest and the occurrence of false negatives is costlier than false positives, may result in adverse consequences. Our paper presents two case studies, each utilizing a unique, combined approach of Random Undersampling and Feature Selection to investigate the effect of class imbalance on big data analytics. Random Undersampling is used to generate six class distributions ranging from balanced to moderately imbalanced, and Feature Importance is used as our Feature Selection method. Classification performance was reported for the Random Forest, Gradient-Boosted Trees, and Logistic Regression learners, as implemented within the Apache Spark framework. The first case study utilized a training dataset and a test dataset from the ECBDL’14 bioinformatics competition. The training and test datasets contain about 32 million instances and 2.9 million instances, respectively. For the first case study, Gradient-Boosted Trees obtained the best results, with either a features-set of 60 or the full set, and a negative-to-positive ratio of either 45:55 or 40:60. The second case study, unlike the first, included training data from one source (POST dataset) and test data from a separate source (Slowloris dataset), where POST and Slowloris are two types of Denial of Service attacks. The POST dataset contains about 1.7 million instances, while the Slowloris dataset contains about 0.2 million instances. For the second case study, Logistic Regression obtained the best results, with a features-set of 5 and any of the following negative-to-positive ratios: 40:60, 45:55, 50:50, 65:35, and 75:25. We conclude that combining Feature Selection with Random Undersampling improves the classification performance of learners with imbalanced big data from different application domains.
Byzantine-Tolerant Inference in Distributed Deep Intelligent System: Challenges and Opportunities

Cyber-physical systems in the Internet-of-Things (IoT) era increasingly need responses that are not only timely, but also intelligent. To that end, decentralized Deep Neural Network (DNN) systems have been studied for near-sensor processing to enable localized inference and global network partition in a given, limited power budget. In the real world, however, such systems are fundamentally heterogeneous in per-node information quality, since each virtually or physically dispersed sensor captures only part of the observable environment. Recent work in collective DNN systems has leveraged this variation in information quality across nodes in a network hierarchy to improve accuracy and reduce design cost. Unfortunately, in noisy or dynamic environments, there are clear optimization challenges in properly measuring information quality or its proxies, which can make such systems even more sensitive to noise than a quality-agnostic design. This implies that the unequal weighting in an information-quality exploiting distributed DNN will likely present new opportunities to subvert collective decision making. Inspired by the classical fault models of distributed systems, specifically those designed to endure coordinated node failure ( Byzantine failure ), this article explores interactions between collaborative DNN models, their reliance on information quality metrics in various fault scenarios, and the corresponding system design costs for achieving reasonable accuracy and reliability. As a proof-of-concept, we perform a case study on a distributed multi-view camera system operating under faults introduced both by environmental noise and adversarial inputs, and present results on inference robustness supported by consensus mechanisms in Byzantine settings.
Evaluation of an automatically-constructed graph-based representation for interactive narrative

Interactivity and player experience are inextricably entwined with the creation of compelling narratives for interactive digital media. Narrative shapes and buttresses many such experiences, and therefore designers must construct compelling narrative arcs while carefully considering the effects of interaction on both the story and the player. As the narrative becomes more structurally complex, due to choice-based branching and other player actions, designers need to employ commensurately capable models and visualizations to keep track of that growing complexity. However, previous models of interactive narrative have failed to fully capture interactive elements with automated, operationalized visualizations. In this paper, we describe an algorithm for automated construction of a framework-driven, graph-based representation of interactive narrative. This representation more fully and transparently models structural and interactive features of the narrative than did prior approaches. We present an initial evaluation of this representation, based on modified cognitive walkthroughs performed by interactive narrative design and research experts from our research team, and we describe the takeaways for future improvement on interactive narrative modeling and analysis.
Statistical Estimates Of Hominin Origination And Extinction Dates: A Case Study Examining The Australopithecus Anamensis–Afarensis Lineage

Abstract Reliable estimates of when hominin taxa originated and went extinct are central to addressing many paleoanthropological questions, including those relating to macroevolutionary patterns. The timing of hominin temporal ranges can be used to test chronological predictions generated from phylogenetic hypotheses. For example, hypotheses of phyletic ancestor–descendant relationships, based on morphological data, predict no temporal range overlap between the two taxa. However, a fossil taxon's observed temporal range is almost certainly underestimated due to the incompleteness of both the fossil record itself and its sampling, and this decreases the likelihood of observing temporal overlap. Here, we focus on a well-known and widely accepted early hominin lineage, Australopithecus anamensis–afarensis, and place 95% confidence intervals (CIs) on its origination and extinction dates. We do so to assess whether its temporal range is consistent with it being a phyletic descendant of Ardipithecus ramidus and/or a direct ancestor to the earliest claimed representative of Homo (i.e., Ledi-Geraru). We find that the last appearance of Ar. ramidus falls within the origination CI of Au. anamensis–afarensis, whereas the claimed first appearance of Homo postdates the extinction CI. These results are consistent with Homo evolving from Au. anamensis–afarensis, but temporal overlap between Ar. ramidus and Au. anamensis–afarensis cannot be rejected at this time. Though additional samples are needed, future research should extend our initial analyses to incorporate the uncertainties surrounding the range endpoints of Ar. ramidus and earliest Homo. Overall, our findings demonstrate the need for quantifying the uncertainty surrounding the appearances and disappearances of hominin taxa in order to better understand the timing of evolutionary events in our clade's history.
Event-by-event neutron–photon multiplicity correlations in 252Cf(sf)

Abstract Excited nuclear fragments are emitted during nuclear fission. The de-excitation of these fission fragments takes place as sequential emission of neutrons followed by photons. Correlations between neutron and photon multiplicities accompanying fission is thus expected. Fission event generators based on established statistical nuclear physics models predict negative event-by-event correlations in neutron–photon multiplicity. A survey of published experimental results of an event-by-event covariance between the neutron and photon multiplicities emitted following the spontaneous fission of 252Cf is presented. Analytic unfolding expressions are developed in this work to determine the bias introduced by background sources, particle misclassification, pulse pileup, and inelastic photon production. The published experimental data are re-analyzed using these unfolding techniques and are found to be in qualitative agreement with the predictions of model-based calculations. In particular, we have concluded that there exists a significant event-by-event neutron–photon emission competition following the spontaneous fission of 252Cf.
Towards Positive Aging: Links between Forgiveness and Health.

Forgiveness may serve as an essential positive resource to help individuals cope emotionally with stressful events, ultimately influencing health. Examination of how individuals forgive within the context of close relationships can provide useful information about positive aging. In this study, we examine how the severity of a recent transgression committed by a spouse/partner or other close social relationship is associated with self-reported physical health among older adults. We also examine how state forgiveness (i.e., in context of a specific event) can offset the potentially negative impact of transgressions on health and further compare the impact when the transgressor is a spouse/partner versus another close social relationship. Data are from the Detroit Community Survey, a cross-sectional survey of social relations, forgiveness, humility, and health in the Detroit Metropolitan Area. Respondents age 50 and older were selected for analysis (N=380). Structural equation models indicated that greater transgression severity was associated with worse self-rated health. Further, state forgiveness was found to play a significant moderating role. Among older adults who were more likely to forgive their transgressor, experiencing a more severe transgression was associated with worse health. In contrast, among older adults less likely to forgive, there was no association between transgression severity and self-rated health. Additionally, among older adults less likely to forgive, the transgressor being a close other social relationship was associated with worse health compared to when it was a spouse/partner. In contrast, when more likely to forgive there was no association between who the transgressor was and self-rated health. This study contributes to a better understanding of how interpersonal stress, specifically a recent transgression experienced within the context of close social relationships, can be harmful to older adults’ health. Findings highlight the importance of forgiveness as a resource that can help facilitate positive aging.
Impact of alcohol and drug use on smoking and cessation in socioeconomically disadvantaged young adults.

Abstract Introduction Population studies highlight that alcohol and marijuana use are correlated with cigarette smoking and other tobacco use. The aim of our study was to describe the ways in which alcohol and drug use may affect cigarette smoking and cessation in socioeconomically-disadvantaged young adult (SDYA) smokers. Methods Thirty-six SDYA smokers aged 18–29 participated in eight focus groups and two individual interviews in Burlington, Vermont in 2018. Structured focus groups addressed poly-tobacco use, other substance use and co-use with tobacco, and the contexts and facilitators that cue SDYA smoking. Participants were also asked their reasons for smoking, barriers to cessation, and messages or modalities that would make smoking cessation more novel or relevant. Three coders implemented the Framework Method to systematically code focus group transcripts. Results In this sample of SDYA smokers, four key themes emerged around the relationships between alcohol and drug use and smoking: 1) frequent co-use of tobacco and other substances, 2) changes in frequency of smoking when using other substances, including chain smoking when drinking and substituting cigarettes with marijuana, 3) cigarettes as a last remaining addiction for those in recovery from other substance use and, 4) fears that quitting smoking would cause relapse to other substances. Discussion Co-use of other substances emerged as a reason for smoking and a barrier to quitting, including a concern that quitting smoking would trigger drug or alcohol relapse. Findings support demand for interventions that address substance co-use to improve smoking cessation in SDYA smokers.
Abstract 5695: Induction of lymphangiogenesis in breast cancer enhances responsiveness to immunotherapies

Growth and remodeling of tumor-associated lymphatics, termed lymphangiogenesis, has been known to increase metastasis rate in cancer patients. However, a recent study from our group has shown that tumor-associated lymphatics can improve anti-tumor immunity in melanoma upon treatment with immunotherapies. The role of lymphangiogenesis in shaping anti-tumor immune responses in breast cancer, however, remains unexplored. Furthermore, recently approved checkpoint inhibitor immunotherapies have had limited success in breast cancer patients. A better understanding of the role of tumor-associated lymphatics in shaping anti-tumor immune responses could lead to more informed decisions when treating breast cancer patients with immunotherapies. In this study, we investigated the role of induced tumor lymphangiogenesis in modulating responsiveness to different immunotherapies in a murine triple-negative mammary carcinoma model. Spontaneously metastatic 4T1 tumor cells were transduced to over-express the pro-lymphangiogenic growth factor VEGF-C (VC) to induce tumor lymphangiogensis in vivo. Flow cytometry and immunohistochemistry analyses confirmed that VEGF-C over-expressing tumors have an increase in tumor-associated lymphatics than control ones. Higher infiltrations of conv CD4 T cells and macrophages were observed in lymphangiogenic 4T1 tumors. Lymphangiogenic tumors treated with aPD-1 and aCTLA-4 checkpoint inhibitors, or an agonist of the Stimulator of Interferon Genes (STING) pathway, showed improved responsiveness to the therapy compared to the control tumors, as indicated by a reduced tumor growth rate. Moreover, positive correlations between VEGF-C expression and CD4 T cell and macrophage gene expressions were observed in primary human triple-negative breast tumor samples from The Cancer Genome Atlas (TCGA). In conclusion, our study shows that increase in tumor-associated lymphatics in triple-negative breast cancer enhances responsiveness to immunotherapies. Citation Format: Peyman Hosseinchi, Aslan Mansurov, Lea Maillat, Lambert Potin, Gavin Fujimori, Jeffrey A. Hubbell, Melody A. Swartz. Induction of lymphangiogenesis in breast cancer enhances responsiveness to immunotherapies [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5695.
Machine-learning model successfully predicts patients at risk for prolonged postoperative opioid use following elective knee arthroscopy.

Recovery following elective knee arthroscopy can be compromised by prolonged postoperative opioid utilization, yet an effective and validated risk calculator for this outcome remains elusive. The purpose of this study is to develop and validate a machine-learning algorithm that can reliably and effectively predict prolonged opioid consumption in patients following elective knee arthroscopy. A retrospective review of an institutional outcome database was performed at a tertiary academic medical centre to identify adult patients who underwent knee arthroscopy between 2016 and 2018. Extended postoperative opioid consumption was defined as opioid consumption at least 150 days following surgery. Five machine-learning algorithms were assessed for the ability to predict this outcome. Performances of the algorithms were assessed through discrimination, calibration, and decision curve analysis. Overall, of the 381 patients included, 60 (20.3%) demonstrated sustained postoperative opioid consumption. The factors determined for prediction of prolonged postoperative opioid prescriptions were reduced preoperative scores on the following patient-reported outcomes: the IKDC, KOOS ADL, VR12 MCS, KOOS pain, and KOOS Sport and Activities. The ensemble model achieved the best performance based on discrimination (AUC = 0.74), calibration, and decision curve analysis. This model was integrated into a web-based open-access application able to provide both predictions and explanations. Following appropriate external validation, the algorithm developed presently could augment timely identification of patients who are at risk of extended opioid use. Reduced scores on preoperative patient-reported outcomes, symptom duration and perioperative oral morphine equivalents were identified as novel predictors of prolonged postoperative opioid use. The predictive model can be easily deployed in the clinical setting to identify at risk patients thus allowing providers to optimize modifiable risk factors and appropriately counsel patients preoperatively. III.
The Okur-Chung Neurodevelopmental Syndrome (OCNDS) mutation CK2K198R leads to a rewiring of kinase specificity

Abstract Okur-Chung Neurodevelopmental Syndrome (OCNDS) is caused by heterozygous mutations to the CSNK2A1 gene, which encodes the alpha subunit of casein kinase II (CK2). The most frequently occurring mutation is lysine 198 to arginine (K198R). To investigate the impact of this mutation, we first generated a high-resolution phosphorylation motif of CK2WT, including the first characterization of specificity for tyrosine phosphorylation activity. A second high resolution motif representing CK2K198R substrate specificity was also generated. Here we report for the first time the impact of the OCNDS associated CK2K198R mutation. Contrary to prior speculation, the mutation does not result in a loss of function, but rather shifts the substrate specificity of the kinase. Broadly speaking the mutation leads to 1) a decreased preference for acidic residues in the +1 position, 2) a decreased preference for threonine phosphorylation, 3) an increased preference for tyrosine phosphorylation, and 4) an alteration of the tyrosine phosphorylation specificity motif. To further investigate the result of this mutation we have developed a probability-based scoring method, allowing us to predict shifts in phosphorylation in the K198R mutant relative to the wild type kinase. As an initial step we have applied the methodology to the set of axonally localized ion channels in an effort to uncover potential alterations of the phosphoproteome associated with the OCNDS disease condition.
Meatpacking plant workers: A case study of a precarious workforce.

Despite longstanding evidence that meatpacking and meat processing workers are at increased risk of work-related injury and illness, the meat processing industry continues to be more hazardous than...
Differentiable Synthetic Aperture Radar Image Formation and Generalized Minimum Entropy Autofocus

In this article we describe a novel minimum entropy autofocus framework that can estimate pulse-to-pulse phase and time delay corrections as well as pulse-to-pulse corrections to the sensor trajectory by optimizing image focus. This optimization is accomplished by viewing the image entropy as a composition of the entropy functional and the image formation operator and using the automatic differentiation capabilities of modern machine learning packages to compute the gradient of the objective function, effectively differentiating the full image formation processing chain.
Partitioning of gene expression among zebrafish photoreceptor subtypes.

Vertebrate photoreceptors are categorized into two broad classes, rods and cones, responsible for dim- and bright-light vision, respectively. While many molecular features that distinguish rods and cones are known, gene expression differences among cone subtypes remain poorly understood. Teleost fishes are renowned for the diversity of their photoreceptor systems. Here, we used single-cell RNA-seq to profile adult photoreceptors in zebrafish, a teleost. We found that in addition to the four canonical zebrafish cone types, there exist subpopulations of green and red cones (previously shown to be located in the ventral retina) that express red-shifted opsin paralogs (opn1mw4 or opn1lw1) as well as a unique combination of cone phototransduction genes. Furthermore, the expression of many paralogous phototransduction genes is partitioned among cone subtypes, analogous to the partitioning of the phototransduction paralogs between rods and cones seen across vertebrates. The partitioned cone-gene pairs arose via the teleost-specific whole-genome duplication or later clade-specific gene duplications. We also discovered that cone subtypes express distinct transcriptional regulators, including many factors not previously implicated in photoreceptor development or differentiation. Overall, our work suggests that partitioning of paralogous gene expression via the action of differentially expressed transcriptional regulators enables diversification of cone subtypes in teleosts.
Early Intervention via Stimulation of the Medial Septal Nucleus Improves Cognition and Alters Markers of Epileptogenesis in Pilocarpine-Induced Epilepsy

Over one-third of patients with temporal lobe epilepsy are refractory to medication. In addition, anti-epileptic drugs often exacerbate cognitive comorbidities. Neuromodulation is an FDA treatment for refractory epilepsy, but patients often wait >20 years for a surgical referral for resection or neuromodulation. Using a rodent model, we test the hypothesis that 2 weeks of theta stimulation of the medial septum acutely following exposure to pilocarpine will alter the course of epileptogenesis resulting in persistent behavioral improvements. Electrodes were implanted in the medial septum, dorsal and ventral hippocampus, and the pre-frontal cortex of pilocarpine-treated rats. Rats received 30 min/day of 7.7 Hz or theta burst frequency on days 4-16 post-pilocarpine, prior to the development of spontaneous seizures. Seizure threshold, spikes, and oscillatory activity, as well as spatial and object-based learning, were assessed in the weeks following stimulation. Non-stimulated pilocarpine animals exhibited significantly decreased seizure threshold, increased spikes, and cognitive impairments as compared to vehicle controls. Furthermore, decreased ventral hippocampal power (6-10 Hz) correlated with both the development of spikes and impaired cognition. Measures of spikes, seizure threshold, and cognitive performance in both acute 7.7 Hz and theta burst stimulated animals were statistically similar to vehicle controls when tested during the chronic phase of epilepsy, weeks after stimulation was terminated. These data indicate that modulation of the septohippocampal circuit early after pilocarpine treatment alters the progression of epileptic activity, resulting in elevated seizure thresholds, fewer spikes, and improved cognitive outcome. Results from this study support that septal theta stimulation has the potential to serve in combination or as an alternative to high frequency thalamic stimulation in refractory cases and that further research into early intervention is critical.
Computational Assessment of Hemodynamic Significance in Patients With Intramural Anomalous Aortic Origin of the Coronary Artery Using Virtually Derived Fractional Flow Reserve and Downstream Microvascular Resistance.

Anomalous aortic origin of a coronary artery (AAOCA) is the second most common cause of sudden cardiac death in young athletes. One of the hypothesized mechanisms of ischemia in these patients is the lateral compression of the anomalous artery with an intramural or interarterial course. The presence of a narrowing in the anomalous artery will cause physiologic changes in downstream resistance that should be included for computational assessment of possible clinical ramifications. In this study, we created different compression levels, i.e., proximal narrowing, in the intramural course of a representative patient model and calculated hyperemic stenosis resistance (HSR) as well as virtual fractional flow reserve (vFFR). Models also included the effect of the distal hyperemic microvascular resistance (HMR) on vFFR. Our results agreed with similar FFR studies indicating that FFR is increased with increasing HMR and that different compression levels could have similar FFR depending on the HMR. For example, vFFR at HSR: 1.0-1.3 and HMR: 2.30 mmHg/cm/s is 0.68 and close to vFFR at HSR: 0.6-0.7 and HMR: 1.6 mmHg/cm/s, which is 0.7. The current findings suggest that functional assessment of anomalous coronary arteries through FFR should consider the vascular resistance distal to the narrowing in addition to the impact of a proximal narrowing and provides computational approaches for implementation of these important considerations.
Learning to Train CNNs on Faulty ReRAM-based Manycore Accelerators

The growing popularity of convolutional neural networks (CNNs) has led to the search for efficient computational platforms to accelerate CNN training. Resistive random-access memory (ReRAM)-based manycore architectures offer a promising alternative to commonly used GPU-based platforms for training CNNs. However, due to the immature fabrication process and limited write endurance, ReRAMs suffer from different types of faults. This makes training of CNNs challenging as weights are misrepresented when they are mapped to faulty ReRAM cells. This results in unstable training, leading to unacceptably low accuracy for the trained model. Due to the distributed nature of the mapping of the individual bits of a weight to different ReRAM cells, faulty weights often lead to exploding gradients. This in turn introduces a positive feedback in the training loop, resulting in extremely large and unstable weights. In this paper, we propose a lightweight and reliable CNN training methodology using weight clipping to prevent this phenomenon and enable training even in the presence of many faults. Weight clipping prevents large weights from destabilizing CNN training and provides the backpropagation algorithm with the opportunity to compensate for the weights mapped to faulty cells. The proposed methodology achieves near-GPU accuracy without introducing significant area or performance overheads. Experimental evaluation indicates that weight clipping enables the successful training of CNNs in the presence of faults, while also reducing training time by 4X on average compared to a conventional GPU platform. Moreover, we also demonstrate that weight clipping outperforms a recently proposed error correction code (ECC)-based method when training is carried out using faulty ReRAMs.
Does Firm Age Affect Cash Policies

This study investigates the linkages between firm age and cash holdings. We document that younger firms save more cash from their cash flows, while we do not find any systematic cash saving pattern for older firms. This linkage is robust to controlling for firm size, and other control variables known to affect cash policy. Our finding is consistent with the idea that younger firms face more financing frictions than older firms and hence have stronger need to save cash.
A LABORATORY STUDY OF OSCILlATIONS IN DIFFERENTIALLY HEATED lAYERS OF MERCURY

The behavior of liquid mercury held in a variety of closed rigid-wall containers, and subjected to differential heating at the vertical sidewalls, was investigated in the laboratory. In the fluid annulus, the primary instability which first occurs as the heating is increased takes the form of azimuthal (3-dimensional) travelling waves, in qualitative agreement with recent weakly nonlinear theory. In boxes of small to unit cross-stream aspect ratio (depth to width), the primary instability remains 3-dimensional, and retains some signatures characteristic of travelling waves. As the applied temperature differences are increased, the convection undergoes secondary bifurcations involving subharmonics and quasi-periodicities. The motions, and their interpretation, are quite sensitive to probe size and location.
Crack tip fields in soft elastic solids subjected to large quasi-static deformation — A review

Abstract We review analytical solutions for the asymptotic deformation and stress fields near the tip of a crack in soft elastic solids. These solutions are based on finite strain elastostatics and hyperelastic material models, and exhibit significantly different characteristics than the classical crack tip field solutions in linear elastic fracture mechanics. Specifically, we summarize some available finite strain crack tip solutions for two dimensional cracks, namely that plane strain, plane stress, and anti-plane shear cracks in a certain class of homogeneous materials. Interface cracks between soft elastic solids and a rigid substrate are also discussed. We focus on incompressible material models with various degrees of strain stiffening effect such as generalized neo-Hookean model, exponentially hardening model and Gent model. We also explored the physical implications of the crack tip fields, and highlighted pitfalls in the applications of these solutions, particularly the J-integral and the distribution of true stress in the deformed configuration which have not been discussed in the literature.
Swirling Shallow Submerged Turbulent Plumes

A mathematical model, using method of images and various flux conservation equations for a swirling deeply submerged plume, has been developed to predict the flow development of a shallow submerged jet near a free surface. The swirl imparted to the effluent plume reduces the length of its flow development along the axial direction. The migration of the maximum velocity and maximum temperature (or density) excess loci towards the free surface is initiated earlier, and these loci reach the free surface at a shorter distance downstream from the orifice, with increasing degrees of the initial swirl of the jets. The increasing submergence of the jet increases both the lateral and longitudinal spread of the jet and the thermal contamination of the body of the water in the reservoir.
Der Streuquerschnitt bei der Beugung am metallischen Kreiszylinder für eine ebene Welle, deren elektrisches Feld senkrecht zur Zylinderachse liegt

Das elektrische Feld der einfallenden ebenen Welle sei in der y-Richtung polarisiert (Fig. 5.1). Zufolge der Symmetrie des Problems existieren nur die Feldkomponenten E x , E y und H z ; der Oberflachenstrom auf dem Zylindermantel mit dem Radius α besitzt daher die zirkulare Komponente Iφ.
DIGITAL MEDIA AND THE GENERATION GAP

In many parts of the developed world, families engage with a wide range of communication media as a part of their daily lives. Parents often express mixed feelings about this engagement on the part of young people, however. Employing Baumberg's narrative-in-interaction analysis to interviews with 55 parents and 125 young people, this article explores both the discursive strategies parents employ when discussing their rules and regulations regarding digital technologies, and the strategies employed by their teenage young people in response. It considers how parents attempt to articulate authority in relation to digital media use among their teenage children, and how the ways in which teens interpret those parental attempts to express authority influence the strategies they themselves embrace regarding digital media. The article argues that although economically disadvantaged families experience the digital generation gap with particular intensity, their strategies reveal that they and their teenage childre...
Computing exact aspect graphs of curved objects: parametric surfaces

This paper introduces a new approach for computing the exact aspect graph of curved objects observed under orthographic projection. Curves corresponding to various visual events partition the Gaussian sphere into regions where the image structure is stable. A catalogue of these events for piecewise-smooth objects is available from singularity theory. For a solid bounded by rational parametric patches and their intersection curves, it is shown that each visual event is characterized by a system of n polynomials in n + 1 variables whose solutions can be found by numerical curve tracing methods. Combining these methods with ray tracing, it is possible to characterize the stable image structure within each region. Results from a preliminary implementation are presented.
Parallel Computation and Visualization Tools for Codetermination Analysis of Multivariate Gene Expression Relations

This chapter presents PAGE, a parallel program for analyzing the codetermination of gene transcriptional states from large-scale simultaneous gene expression measurements with cDNA microarrays, and its application to a large set of genes. Using PAGE, it was possible to compute coefficients of determination for all possible three-predictor sets from 587 genes for 58 targets in a reasonable amount of time. Given the limited samplesizes currently being used for microarray analysis, it is not necessary to go beyond three predictors at this time since the data are insufficient for four-predictor CoD estimation. As shown in Tables 13.1, 13.2, and 13.3, significant speedups are achieved by the parallelization when compared to the sequential version of the program modules.
« Il y a kébab et kébab : conflit local et alimentation globale en Italie du nord »

Cet article analyse un cas de racisme gastronomique qui a eu lieu dans la ville de Bergame situee dans le nord de l’Italie. Base sur des recherches ethnographiques de longue duree, il s’interesse particulierement a la facon dont les membres d’un groupe Facebook – cree specifiquement pour protester contre la presence d’un stand a kebab dans la Ville Haute (historique) de Bergame – utilisent des ressources semiotiques et linguistiques telles que l’alimentation, le site, le langage et l’experience corporelle pour etablir des limites entre les membres de ce groupe et les intrus. Ce faisant, l’article s’inscrit dans une discussion sur la signification de l’alimentation au sein de communautes et de reseaux locaux et globaux. Il considere que la nourriture est un signifiant puissant et tres marque du global et du local et qu’elle fait partie des debats locaux, nationaux et globaux sur la valeur attribuee aux gens, aux choses, aux pratiques et aux valeurs toujours en mouvement.
The Mind and its Stories: Narrative Universals and Human Emotion

There are profound, extensive, and surprising universals in literature, which are bound up with universals in emotion. Hogan maintains that debates over the cultural specificity of emotion are misdirected because they have ignored a vast body of data that bear directly on the way different cultures imagine and experience emotion - literature. This is the first empirically and cognitively based discussion of narrative universals. Professor Hogan argues that, to a remarkable degree, the stories people admire in different cultures follow a limited number of patterns and that these patterns are determined by cross-culturally constant ideas about emotion. In formulating his argument, Professor Hogan draws on his extensive reading in world literature, experimental research treating emotion and emotion concepts, and methodological principles from the contemporary linguistics and the philosophy of science. He concludes with a discussion of the relations among narrative, emotion concepts, and the biological and social components of emotion.
Perfusion imaging with NMR contrast agents

Knowledge of regional hemodynamics has widespread application for both physiological research and clinical assessment. Here we review the use of MR contrast agents to measure tissue perfusion. Two primary mechanisms of image contrast are discussed: relaxivity and susceptibility effects. Relaxivity effects result from dipolar enhancement of T1 and T2 rates. Because tissue T1 rates are intrinsically smaller, the dominant effect is shortening of T1 relaxation times. The second mechanism of image contrast is the variation in tissue magnetic field produced by heterogeneous distribution of high magnetic susceptibility agents. Quantitation of tissue perfusion requires a detailed understanding of the relation between contrast agent concentration and associated MR signal changes. Studies to date show a linear relationship between contrast agent concentration and rate change in most organs. The exact nature of this relationship in the dynamic setting of rapid contrast agent passage through the microcirculatory bed is less well established. If this relationship is known, tracer kinetic modeling can be used to calculate regional blood flow and blood volume. Data are presented which indicate that this approach is feasible, and suggest the potential of contrast-enhanced NMR for high resolution in vivo mapping of both physiology and anatomy.
Preliminary Experience with Short Course High-Dose Mitoxantrone in Combination with High-Dose Cytarabine in Patients with Acute Leukemia and Blastic Phase of Chronic Myelogenous Leukemia.

Mitoxantrone is effective therapy for patients with acute leukemia and blastic phase of chronic myelogenous leukemia (CML). In vitro mitoxantrone has a steep dose response curve, which suggests that higher doses given in a shorter duration may result in enhanced leukemic cell kill in vivo. Twenty-four patients with acute leukemia and blastic CML received mitoxantrone 20 mg/m2 I.V. daily × 2 with cytarabine 3 g/m2 I.V. once daily × 5 days. Diagnoses included 8 patients with previously untreated acute non-lymphocytic leukemia (ANLL), 9 patients with relapsed ANLL, 4 patients with refractory acute lymphoblastic leukemia (ALL) and 2 patients with blastic CML. Complete remission was achieved in 8 of 17 patients with ANLL, 1 of 4 patients with ALL and 0 of 2 with blastic CML. Extramedullary toxicity was acceptable and the median time to remission was 26 days (range 20-69). Short course high-dose mitoxantrone with high-dose cytarabine is effective and well-tolerated in patients with acute leukemia.
A Computationally Efficient Approach to Trajectory Management for Coordinated Aerial Surveillance

Time optimal path planning and trajectory management algorithms for air vehicles with limited on-board computing resources require an efficient approach to satisfy flight dynamic constraints needed to guarantee paths are feasible. B-spline curves enable compact definition of feasible airplane trajectories that are suited for on-board real-time computation. The design of a trajectory definition and management algorithm suited for a multi-agent persistent surveillance application is described. The proposed solution post-processes the output of a point-by-point path planner and converts it into a minimal representation. Key design requirements include minimization of mission execution time, ability to seamlessly redirect agents based on information acquired by sensor feedback, and robust adherence to mission and vehicle motion constraints. A simple coordinated aerial surveillance scenario is described and demonstrated using the algorithms presented.
Meat Processing and Garden City, KS: Boom and Bust.

Abstract In December 1980, the world's largest beef processing plant opened 10 miles west of Garden City, KS. Three years later another beef plant opened on Garden City's eastern edge. Full employment in the surrounding region meant that most of the 4000 workers needed to run these plants had to come from elsewhere—and they did. Garden City grew by one-third from 1980 to 1985, and it became a modern boomtown. Garden City suffered many of the social problems associated with the energy boomtowns of the Rocky Mountain West described by earlier researchers. But unlike the jobs created in those earlier boomtowns, meatpacking paid poorly and provided few benefits. On Christmas night in 2000, a fire destroyed one of the beef plants, putting 2300 people out of work. Four years after the fire, the plant remains closed and the town's economy is in decline. This paper describes the social and economic consequences for a boomtown when a major engine of its economy goes bust.
Processing stability of squalene in amaranth and antioxidant potential of amaranth extract.

The processing stability of squalene in amaranth and the antioxidant capacity of the oil-rich fraction of amaranth were studied. The processes investigated were continuous puffing and roasting. Puffing was carried out using a single screw extruder, while roasting was carried out in a convection oven. High-performance liquid chromatography was used to quantify squalene content before and after processing. The L-ORAC method was used to study the antioxidant activity of pure squalene and lipophilic amaranth extract containing squalene. It was found that squalene was stable during all of the processing operations with a maximum loss of 12% during roasting (150 °C, 20 min) and no loss during puffing. The L-ORAC test showed pure squalene to be a weak antioxidant, whereas the lipophilic extract of amaranth showed higher antioxidant activity as compared to pure squalene at the same concentration, suggesting that tocotrienols and other minor ingredients also played a role as antioxidants.
Regulation of platelet granule exocytosis by S-nitrosylation

Nitric oxide (NO) regulates platelet activation by cGMP-dependent mechanisms and by mechanisms that are not completely defined. Platelet activation includes exocytosis of platelet granules, releasing mediators that regulate interactions between platelets, leukocytes, and endothelial cells. Exocytosis is mediated in part by N-ethylmaleimide-sensitive factor (NSF), an ATPase that disassembles complexes of soluble NSF attachment protein receptors. We now demonstrate that NO inhibits exocytosis of dense granules, lysosomal granules, and α-granules from human platelets by S-nitrosylation of NSF. Platelets lacking endothelial NO synthase show increased rolling on venules, increased thrombosis in arterioles, and increased exocytosis in vivo. Regulation of exocytosis is thus a mechanism by which NO regulates thrombosis.
Physiological studies of single retinal cells and their morphological identification.

Intracellular recordings were made from various types of cells in goldfish retina. Receptive fields of these cells were studied with light spots of different sizes. After recording, the cells were identified morphologically by injecting dyes from the recording electrode: thus correlation was made between cell types and their characteristic responses. Receptors were hyperpolarized by illumination. No obvious spatial summation was seen in these responses. Regardless of wavelength, receptors were always hyperpolarized. They were classified into three types according to response maxima at red, green and blue region of the spectrum. External and internal horizontal cells were identified as the origin ofS-potentials. BothL- andC-type responses were seen from two types of horizontal cells. Electrical coupling was demonstrated between neighboring external horizontal cells; presumably this accounts for large spatial summation ofS-potentials. Bipolar cells had center-surround type receptive field. The size of the center was about 100 μ, the same order of magnitude as the dendritic field. The surround was large, extending to about 1.5 mm dia. The majority of bipolar cells were color-coded; in these cells the center always received input from red cones and the surround from green cones. Amacrine cells showed two types of responses, transient and sustained. Their receptive field was at least 2.5 mm dia. All the sustained type amacrine cells showed opponent color responses; hyperpolarization to red and depolarization to green. No spatial segregation was seen between red sensitive and green sensitive areas. It was suggested that a double opponent ganglion cell receives inputs from bipolar cells in the center and from amacrine cells in the surround.
Real-Time Imaging Reveals that HIV-1 Vpr Dissociates from the Core and Accumulates in the Nucleus after Viral Fusion

Viral protein R (Vpr) is an HIV-1 accessory protein that associates with capsids during viral assembly and is important for infections in non-dividing cells. Vpr functions in host cells include induction of G2 cell-cycle arrest, and regulation of cellular proliferation and apoptosis. Vpr has two nuclear localization sequences that direct its transport to the nucleus. Fluorescently labeled Vpr (YFP-Vpr) is widely used to visualize HIV-1 cores in the cytoplasm during entry. Here we report on the dissociation of YFP-Vpr from HIV-1 cores shortly after viral fusion and its subsequent accumulation in the nuclei. Real-time live cell imaging showed that, under conditions of productive entry and infection, Vpr dissociated from cores post-fusion and accumulated in nuclei over time-scales that correlated with the kinetics of viral fusion (t1/2∼15 min). Nuclear accumulation of Vpr scaled with the number of cell-bound virions and could be blocked by lysosomotropic agents or a fusion-inhibitory peptide. These effects were observed in two cell lines and were independent of the fusion proteins incorporated into viral particles. Fluorescence recovery after photobleaching of YFP-Vpr within the nucleus revealed quick (t1/2∼3 min) recovery, indicating that Vpr dissociation from capsids is a rate-limiting step in Vpr post-fusion transport. Fluorescence correlation spectroscopy measurements on post-fusion nuclear YFP-Vpr, yielded fast and slow diffusive components (D∼10 μm2/s and 0.8 μm2/s, respectively) similar to those measured for YFP-Vpr over-expressed in cells. These diffusion coefficients reflect that nuclear Vpr exists in two forms - as a monomer, and in large complexes with host proteins or perhaps even chromatin structures. Current efforts are underway to explore the determinants of the stability of Vpr-capsid complexes. This work was supported by the NIH R01 GM054787 grant.
Maximal loss from collusion in IPV symmetric auctions

Abstract We derive a bound on the seller's revenue loss in optimal auctions from unanticipated bidder collusion. The relative loss is rather small when there are few bidders. It is increasing with the number of bidders but at a slow rate.
TNF-α Induces Two Distinct Caspase-8 Activation Pathways

The inflammatory response of mammalian cells to TNF-alpha can be switched to apoptosis either by cotreatment with a protein synthesis inhibitor, cycloheximide, or Smac mimetic, a small molecule mimic of Smac/Diablo protein. Cycloheximide promotes caspase-8 activation by eliminating endogenous caspase-8 inhibitor, c-FLIP, while Smac mimetic does so by triggering autodegradation of cIAP1 and cIAP2 (cIAP1/2), leading to the release of receptor interacting protein kinase (RIPK1) from the activated TNF receptor complex to form a caspase-8-activating complex consisting of RIPK1, FADD, and caspase-8. This process also requires the action of CYLD, a RIPK1 K63 deubiquitinating enzyme. RIPK1 is critical for caspase-8 activation-induced by Smac mimetic but dispensable for that triggered by cycloheximide. Moreover, Smac mimetic-induced caspase-8 activation is not blocked by endogenous c-FLIP. These findings revealed that TNF-alpha is able to induce apoptosis via two distinct caspase-8 activation pathways that are differentially regulated by cIAP1/2 and c-FLIP.
Treatment of third ventricle tumors

The treatment of third ventricle tumors is discussed chiefly on the basis of case experience. The various tumors are considered according to their special characteristics and to their location as well; the anteriorly and posteriorly placed tumors of the third ventricle being considered in separate groups. Both the surgical removal and the conservative measures of treatment are described. The advantages of either conservative treatment or surgical removal are discussed in each case with a general resume of the results.