cssi/SciSciGPT-SciSciNet huggingface dataset:
Combining phylogenetic motif discovery and motif clustering to predict co-regulated genes

Motivation: We present a sequence-based framework and algorithm PHYLOCLUS for predicting co-regulated genes. In our approach, de novo discovery methods are used to find motifs conserved by evolution and then a Bayesian hierarchical clustering model is used to cluster these motifs, thereby grouping together genes that are putatively co-regulated. Our clustering procedure allows both the number of clusters and the motif width within each cluster to be unknown. Results: We use our framework to predict co-regulated genes in the bacterium Bacillus subtilis using six other closely related bacterial species. Our predicted motifs and gene clusters are validated using several external sources and significant clusters are examined in detail. An extension to the discovery and clustering of two-block motifs can be used for inference about synergistic binding relationships between transcription factors. Availability: Software and Supplementary Materials can be downloaded at http://stat.wharton.upenn.edu/~stjensen/research/phyloclus.html or http://www.fas.harvard.edu/~junliu/phyloclus.html Contact: stjensen@wharton.upenn.edu
Lessons from the leucovorin shortages between 2009 and 2012 in a medicare advantage population: where do we go from here?

Background Three distinct shortages of the generic drug leucovorin, a reduced form of folic acid used in several chemotherapy regimens, were reported by the US Food and Drug Administration (FDA) between 2008 and 2014. Levoleucovorin, an alternative therapy to leucovorin, failed to demonstrate superiority over leucovorin in clinical trials and is substantially more expensive.
Dynamic Programming for Phase and Frequency Tracking

The techniques of dynamic programming have found a variety of successful applications in signal and system theory. In this paper we show how two knotty nonlinear filtering problems—phase and frequency tracking—may be formulated and solved as forward dynamic programming problems. The resulting solutions are fixed interval smooths in which a most likely sequence is passed through a data record.
Measurements of calcium transients in ventricular cells during discontinuous action potential conduction

The L-type calcium current (I Ca) is important in sustaining propagation during discontinuous conduction. In addition, I Ca is altered during discontinuous conduction, which may result in changes i...
Shipping suppresses lymphocyte blastogenic responses in Angus and Brahman X Angus feeder calves

An experiment using 40 Angus or Brahman X Angus preconditioned feeder calves was conducted to evaluate the influence of shipping on cellular immune reactivity. Steers were allotted on the basis of weight and breed to a control or shipped group. Shipped steers were trucked 700 km to a feedlot; control steers remained at the ranch of origin. Total and differential leukocyte counts, phytohemagglutinin skin-test responses, lymphocyte blastogenic responses, monocyte phagocytic function, packed cell volumes and concentrations of plasma cortisol were determined before, immediately after and 1 wk after shipment. At unloading, total leukocytes were increased (P less than .05) in shipped Angus steers. Shipped steers also had higher (P less than .01) numbers of neutrophils. Skin-test responses to phytohemagglutinin were higher (P less than .05) in Angus than in Brahman X Angus steers, but shipping did not influence the reaction. Lymphocyte blastogenic responses were lower (P less than .05) in shipped steers; however, cortisol levels in plasma were not elevated (P greater than .10) in shipped calves. Monocyte phagocytosis and packed cell volume were not influenced by shipping. These data suggest that shipped steers have suppressed lymphocyte blastogenic responses.
3D Imaging of Retinal Pigment Epithelial Cells in the Living Human Retina.

Purpose Dysfunction of the retinal pigment epithelium (RPE) underlies numerous retinal pathologies, but biomarkers sensitive to RPE change at the cellular level are limited. In this study, we used adaptive optics optical coherence tomography (AO-OCT) in conjunction with organelle motility as a novel contrast mechanism to visualize RPE cells and characterize their 3-dimensional (3D) reflectance profile. Methods Using the Indiana AO-OCT imaging system (λc = 790 nm), volumes were acquired in the macula of six normal subjects (25-61 years). Volumes were registered in 3D with subcellular accuracy, layers segmented, and RPE and photoreceptor en face images extracted and averaged. Voronoi and two-dimensional (2D) power spectra analyses were applied to the images to quantify RPE and cone packing and cone-to-RPE ratio. Results Adaptive optics OCT revealed two distinct reflectance patterns at the depth of the RPE. One is characterized by the RPE interface with rod photoreceptor tips, the second by the RPE cell nuclei and surrounding organelles, likely melanin. Increasing cell contrast by averaging proved critical for observing the RPE cell mosaic, successful in all subjects and retinal eccentricities imaged. Retinal pigment epithelium mosaic packing and cell thickness generally agreed with that of histology and in vivo studies using other imaging modalities. Conclusions We have presented, to our knowledge, the first detailed characterization of the 3D reflectance profile of individual RPE cells and their relation to cones and rods in the living human retina. Success in younger and older eyes establishes a path for testing aging effects in larger populations. Because the technology is based on OCT, our measurements will aid in interpreting clinical OCT images.
Delayed cerebral infarct following anterior cervical diskectomy and fusion

Background Ischemic stroke following anterior cervical diskectomy and fusion (ACDF) is an exceedingly rare complication. There are only three previous cases focusing on this problem in the literature; here, we present the fourth case. Case description A patient, cared for at an outside institution, developed a delayed ischemic stroke 3 days following an ACDF. This complication was attributed to carotid manipulation precipitating vascular injury in the setting of multiple comorbid vascular and coagulopathic risk factors, including previously undiagnosed carotid atherosclerosis, a prior history of pulmonary embolus requiring Warfarin anticoagulation (held perioperatively), acute dehydration, and atrial fibrillation. Conclusions This case demonstrates the importance of focused history and examination in appropriate patients prior to ACDF, with special consideration given to the significance of age, comorbidities including coagulopathy and arrhythmia, and potential underlying vascular disease as markers for increased risk of perioperative thrombotic stroke associated with carotid manipulation. Patients at higher risk warrant comprehensive preoperative assessment, including medical evaluation, carotid imaging, and consideration for alternative surgical approaches.
Microscopic In Size: Macroscopic In Impact. Diatom–Human Interactions

Diatoms are single-celled, photosynthetic organisms that have cell walls made of silica dioxide or glass. They have chlorophylls a and c, and large amounts of the accessory pigments xanthophylls and carotenoids, giving living diatoms a golden brown hue. Unlike green plants and their allies, the storage product of the photosynthetic activity of diatoms is a lipid or oil (Opute, 1974). Diatoms are a part of the tree of life, currently referred to as stramenopiles, a lineage that includes other golden-brown algae, as well as water molds and a variety of small flagellates (Patterson, 1989; Leipe et al., 1994).
Cardiovascular Health among Black and White Breast Cancer Patients Initiating Aromatase Inhibitor Therapy

The purpose of this study was to compare the cardiovascular health of Black and White breast cancer patients undergoing adjuvant treatment. Baseline data from a cohort study of Black (n = 45) and White (n = 101) breast cancer patients initiating aromatase inhibitor treatment were analyzed. Participants had a cardiovascular health assessment, including carotid intimal medial thickness measurement, donated a blood sample, and completed a questionnaire. Atherosclerotic cardiovascular disease (ASCVD) event risk scores were calculated. Compared to their White counterparts, the Black patients had a significantly higher median ASCVD risk score (p = 0.009) and had a higher number of CVD risk factors (p < 0.05). Black patients were also more likely to have hypertension, diabetes, or to be obese than the White participants. The prevalence of cardiovascular disease and cardiovascular disease risk factors among Black and White breast cancer patients is high, and racial disparities exist which may have treatment implications.
Media distortion of the public's perception of recidivism and psychiatric rehabilitation.

OBJECTIVE The public's perception about the success or failure of psychiatric rehabilitation is frequently dependent upon information received through the news media. The primary objective of this report is to present an example of how the news media can distort public perceptions of treatment outcome. METHOD Verbatim quotations were presented from a television news series that alleged criminal recidivism by nine patients purportedly treated for various paraphilias at a large, community-based sexual disorders clinic. Brief case vignettes about each of the nine were then reviewed. This allowed for comparisons between what the media had alleged and what had actually occurred. RESULTS Two of the nine cases were relatively minor instances of recidivism involving no genital contact, although the media presentation had either failed to report this or had suggested otherwise. A third case of alleged recidivism involved a patient who was evaluated but never actually treated by the clinic in the community. A fourth patient had refused recommended clinic treatment upon prison release, and a fifth patient had been discharged from treatment at the clinic because of noncompliance years before recidivating. Other cases presented contained additional misleading information. None of the nine cases was reported by the media in the context of a balanced approach that included treatment successes. Clinic staff were constrained from responding publicly to correct certain misinformation because of patient-psychiatrist privilege. CONCLUSIONS Inaccurate media presentations about psychiatric rehabilitation that ignore treatment successes and focus only on alleged failures do a disservice to patients, mental health workers, and society at large.
A Proteolytic Regulator Controlling Chalcone Synthase Stability and Flavonoid Biosynthesis in Arabidopsis.

Flavonoids represent a large family of specialized metabolites involved in plant growth, development, and adaptation. Chalcone synthase (CHS) catalyzes the first step of flavonoid biosynthesis by directing carbon flux from general phenylpropanoid metabolism to flavonoid pathway. Despite extensive characterization of its function and transcriptional regulation, the molecular basis governing its posttranslational modification is enigmatic. Here, we report the discovery of a proteolytic regulator of CHS, namely, KFBCHS, a Kelch domain-containing F-box protein in Arabidopsis thaliana KFBCHS physically interacts with CHS and specifically mediates its ubiquitination and degradation. KFBCHS exhibits developmental expression patterns in Arabidopsis leaves, stems, and siliques and strongly responds to the dark-to-light (or the light-to-dark) switch, the blue, red, and far-red light signals, and UV-B irradiation. Alteration of KFBCHS expression negatively correlates to the cellular concentration of CHS and the production of flavonoids. Our study suggests that KFBCHS serves as a crucial negative regulator, via mediating CHS degradation, coordinately controlling flavonoid biosynthesis in response to the developmental cues and environmental stimuli.
Verification of randomized security protocols

We consider the problem of verifying the security of finitely many sessions of a protocol that tosses coins in addition to standard cryptographic primitives against a Dolev-Yao adversary. Two properties are investigated here — secrecy, which asks if no adversary interacting with a protocol P can determine a secret sec with probability > 1 − p; and indistinguishability, which asks if the probability observing any sequence 0 in P 1 is the same as that of observing 0 in P 2 , under the same adversary. Both secrecy and indistinguishability are known to be coNP-complete for non-randomized protocols. In contrast, we show that, for randomized protocols, secrecy and indistinguishability are both decidable in coNEXPTIME. We also prove a matching lower bound for the secrecy problem by reducing the non-satisfiability problem of monadic first order logic without equality.
A SEMIDISCRETIZATION PROCEDURE FOR FITZHUGH-NAGUMO EQUATIONS

Publisher Summary This chapter presents a semidiscretization procedure for Fitzhugh–Nagumo equations. It highlights a system of Fitzhugh–Nagumo equations. The chapter presents Rothe's method of semidiscretization. The ODE approximating system is an alternate model for the phenomenon of conduction of the nerve impulse along an axon. In this way, some restrictions imposed on β can be removed when finding the exponential estimate for the small solutions of the problem. In biological terms, the local asymptotic stability of the zero solution means that a certain threshold has to be reached to trigger the nerve. The positive answer to the threshold problem is a consequence of the classical Poincare–Lyapunov theorem, regarding stability in the first approximation. The chapter discusses another case of the threshold problem, using again the Poincare–Lyapunov stability result.
An initial evaluation of a novel anesthetic scavenging interface

Waste anesthetic gas scavenging technology has not changed appreciably in the past 30 years. Open reservoir systems entrain high volumes of room air and dilute waste gases before emission into the atmosphere. This process requires a large vacuum pump, which is both costly to install and, although efficient, operates continuously and at near-full capacity. In an era of increasing energy costs and environmental awareness, carbon footprint reduction is a priority and a more efficient system of safely scavenging waste anesthetic gases is desirable. We tested a low-flow scavenger interface to evaluate the potential for cost and energy savings. The use of this interface in a suite of 4 operating rooms reduced scavenging flow from a constant 37 L/min to a value equal to the fresh gas flow (usually 2 L/min) for each anesthesia machine. Using the ventilator increased this flow by approximately 6 L/min because of the exhaust of ventilator drive gas into the scavenging circuit. Daytime workload of the central vacuum pump decreased from 92% to 12% (expressed as duty cycle). The new system produces energy savings and may increase vacuum pump lifespan.
Multi-feature fusion based approach for robust face recognition

How to describe an image accurately with the most useful information is the key issue of any face recognition task. Therefore, finding efficient and discriminative facial information that should be stable under different conditions of the image acquisition process is a huge challenge. Most existing approaches use only one type of features. In this paper, we argue that a robust face recognition technique requires several different kinds of information to be taken into account, suggesting the incorporation of several feature sets into a single fused one. Therefore, a new technique that combines the facial shape with the local structure and texture of the face image is proposed, namely multi-feature fusion (MFF). It is based on local boosted features (LBF) and Gabor wavelets techniques. Given an input image, the LBF histogram and Gabor features histogram are built separately. Then a final MFF feature descriptor is formed by concatenating these three histograms, which feeds to the support vector machine (SVM) classifier to recognize the face image. The proposed MFF approach is evaluated on three different face datasets and provided promising results.
Primary Photochemistry in Reaction Centers from the HisM200→Leu Mutant of Rhodobacter Capsulatus

The initial transient state observed immediately following excitation of reaction centers from the HisM200→Leu mutant of Rb. capsulatus with a 350-fs flash is the intradimer charge transfer state [BChlLP +BPhMP -]. This state has a lifetime of about 14 ps and decays with nearly equal probabilities via electron transfer to BPhL and via rapid internal conversion (charge recombination) to the ground state. Essentially the same behavior is observed at room and liquid N2 temperature. These results provide important insights into how the electronic properties of the primary electron donor dictate the initial stage of the charge separation process.
INDUSTRY AND PRACTICE: The Database Designer is a Person Too!

Human factors research focuses almost exclusively on the end-user of an information system and very little on the human factors of the people designing the information system. Anecdotal evidence suggests the importance of highly skilled individuals to the successful development of information systems. Research suggests that successful development may have more to do with the people doing the development than the methodology that they are using. This paper reviews some of the literature from cognitive science and psychology and suggests that the process of database design may be vulnerable to the cognitive factors of the person doing the design. Some suggestions are provided for controlling these cognitive influences.
The Stirred Tank: Mixing Time and Power Requirement

When using a rotating impeller to mix fluids contained in a tank, we ask two questions: What size motor do we need for a given impeller rotation speed? How long must we mix the fluid to achieve a required degree of uniformity?
Laboratory and field assessments of erythritol derivatives on the survival, reproductive rate, and control of Drosophila suzukii (Diptera: Drosophilidae).

Spotted-wing Drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a vinegar fly introduced unintentionally into the United States. Since 2008, D. suzukii has reduced annual berry yields from 6 to 100%. Effective control of D. suzukii during harvest requires weekly applications of low-residual, broad-spectrum insecticides that are unavailable for organic farming. A novel ingestible insecticide, a 4-carbon polyol, mesoerythritol (erythritol), was found to kill 75 to 100% of larval and adult D. suzukii. However, mesoerythritol, at effective concentrations (0.5-1.0M), may be cost-prohibitive. Therefore, we conducted laboratory tests to assess the effects of lower cost derivatives of erythritol, namely the pentaerythritol series of 1,3-diols on D. suzukii pupal production, adult production, adult mortality, brood output, and reproductive increase. We then selected the two most promising compounds for a field test on fruiting rabbiteye blueberry. From 90 to 100% of adults died when fed food moistened with 1M solutions of mesoerythritol and pentaerythritol. Mesoerythritol and dipentaerythritol at a concentration of 1M were ovicidal/larvicidal, killing ≥85% of immatures. Overall, 1M mesoerythritol killed 80% or more larvae and adults, thus bringing populations to near zero. The heaviest compound of this series, tripentaerythritol, at all concentrations, was largely benign to both adults and immatures. Thus, we cannot recommend tripentaerythritol for D. suzukii control. In a blueberry field, 0.5M mesoerythritol and 0.5M pentaerythritol, each by themselves, reduced egg infestation by 64% and larval infestation by 93%; their combination (0.25M mesoerythritol and 0.25M pentaerythritol) achieved even greater egg control with 82% fewer eggs infesting blueberry fruits.
Some Properties of the Prolongation Limit Random Sets in Random Dynamical Systems

The aim of this paper is to study the omega limit set with new concepts of the prolongation limit random sets in random dynamical systems, where some properties are proved and introduced such as the relation among the orbit closure, orbit and omega limit random set. Also we prove that the first prolongation of a closed random set containing this set, the first prolongation is closed and invariant. In addition, it is connected whenever it is compact provided that the phase space of the random dynamical systems is locally compact. Then, we study the prolongational limit random set and examined some essential properties of this set. Finally, the relation among the first prolongation, the prolongational limit random set and the positive trajectory of a random set is given and proved.
Photon-gated spectral tote burning in Li-Ga5O8:Co2+

The recently discovered phenomenon of photon-gated spectral hole burning1,2 has been extended to transition metal compounds with trie observation of gated hole burning in LiGa5O8:Co2+.
Systems Thinking as a Tool for Teaching Undergraduate Business Students Humanistic Management

In growing recognition that the business community must play a key role in the global issues encapsulated by the United Nations Sustainable Development Goals, Babson College, which has a business-focused curriculum, has striven first to reinvent its teaching of ethics and then, particularly over the past decade, to enhance its focus on sustainability, social responsibility, and social entrepreneurship. As previous initiatives did not build sufficient linkages between the liberal arts, natural sciences, and business curriculum, the College is now engaged in a far more comprehensive effort to educate our undergraduate business students in “integrated sustainability,” which it defines as “systems thinking that integrates ecological integrity, social responsibility, and value creation simultaneously.” By examining the meaning, skills, and pedagogical opportunities in systems thinking within the context of larger discussions on humanistic management, this article shows how systems thinking is a particularly fruitful way to ground business students in the natural sciences and the liberal arts, develop their complex problem-solving skills, and thereby reinvigorate management education in ways that prepares students to “render service to humanity.” Our hope is that sharing Babson College’s experience in this regard – both our successes and challenges - may provide useful insights to other faculty and academic leaders seeking to enhance humanistic management within their own higher education institutions.
Comorbidity burden on receipt of adjuvant immunotherapy and survival in patients with stage III melanoma: an analysis of the National Cancer Database.

BACKGROUND Comorbidity burden is associated with development of cancer, stage at diagnosis, and treatment outcomes. We evaluated the association between comorbidity burden, receipt of adjuvant immunotherapy, and survival in patients with stage III melanoma. METHODS Using the National Cancer Database, we identified 16,906 patients with stage III melanoma who underwent surgery of the primary site. Outcomes included receipt of adjuvant immunotherapy and overall survival; independent variables included Charlson/Deyo comorbidity index (CDI) and receipt of adjuvant immunotherapy. RESULTS Patients with CDI scores of two or more averaged 30.0% and 30.9% lower adjusted odds of receiving adjuvant immunotherapy relative to patients with a CDI score of zero or one, respectively (P = 0.001 and 0.002, respectively). Longer survival was associated with lower CDI scores (all P < 0.001) and receipt of adjuvant immunotherapy (P < 0.001). Patients who received adjuvant immunotherapy averaged 16.0% lower adjusted risk of death compared to patients who did not (P < 0.001), which was constant within all CDI cohorts. Patients with a CDI score of two or more averaged 53.4% and 39.1% higher adjusted risk of death relative to patients with a CDI score of zero or one (both P < 0.001). CONCLUSION Greater comorbidity burden was associated with lower receipt of adjuvant immunotherapy; however, adjuvant immunotherapy provided similar survival benefit for patients' irrespective comorbidity burden. Our findings suggest that patients with stage III melanoma who have a greater comorbidity burden may benefit from adjuvant immunotherapy but should not replace careful patient selection by the clinician.
Abstract 4415: Exploiting convergent evolution to derive a cisplatin sensitivity gene expression signature in epithelial based cancer

Significance: Gene expression signatures have been successfully used in radiotherapy dosing, predicting benefit of adjuvant chemotherapy, and prognosticating based on hypoxic state. Yet, despite these successes, these tools often fall short in validation between datasets and translation to clinical use. We propose a novel method for deriving more robust gene expression signatures predictive of chemotherapeutic response. Although this method may be applied to any drug, here, we derive a signature to predict cisplatin sensitivity in epithelial-based cancer cell lines. Methodology: We ranked epithelial-based cell lines from the Genomics of Drug Discovery in Cancer dataset based on their response to cisplatin (IC50). Differential gene expression analysis between resistant and sensitive cell lines was performed using the SAM, limma, and multtest algorithms implemented with R. The intersection of the DE results from each method became the seed genes in a co-expression network built from TCGA gene expression data. The most highly co-expressed seed genes are extracted and they are termed “connectivity genes.” We perform this analysis 5 times, each time excluding 20% of the GDSC dataset. We formed the final signature by combining genes found in at least 3 of the 5 connectivity gene sets. A cell line9s median expression of the signature genes is termed its “signature score.” Using 5-fold cross validation, models are built to predict IC50 given a cell line9s signature score or expression of all signature genes. For every model built testing our gene signature, a null distribution of performance metrics was produced by repeating the procedure 1000 times with random gene signatures of the same length as the signature in question. Results: The final signature contains 13 genes: ADA, NPM3, CSTA, KRT5, KRT14, ATP1B3, LY6K, USP31, BNC1, MAP7D3, LRRC8C, C15orf41, and SLFN11. Using linear regression to predict a cell line9s IC50 from its signature score, the predicted vs. actual rank of IC50 has a Spearman correlation coefficient of 0.408 and a p-value of Conclusions: We have demonstrated that our method is capable of deriving gene expression signatures predictive of chemotherapeutic response. Because extracted genes are co-expressed in both cancer cell lines (GDSC) and patient tumor samples (TCGA), we hypothesize that these signatures should have improved robustness in novel datasets and translation to clinical use. Citation Format: Jessica Scarborough, Andrew Dhawan, Jacob Scott. Exploiting convergent evolution to derive a cisplatin sensitivity gene expression signature in epithelial based cancer [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 4415.
Study of Migration and Later Life Health in Nepal.

Abstract Purpose This study investigates long-term consequences of individual migration experience on later life health, specifically self-rated health and functional difficulty. Design/methodology/approach The study uses multiple community-, household-, and individual-level data sets from the Chitwan Valley Family Study (CVFS) in Nepal. The CVFS selected a systematic probability sample of 151 neighborhoods in Western Chitwan and collected information on all households and individuals residing in the selected sample neighborhoods. This study uses data from multiple surveys featuring detailed migration histories of 1,373 older adults, and information on their health outcomes, households, and communities. Findings Results of the multi-level multivariate analysis show a negative association between number of years of migration experience and self-rated health, and a positive association between migration and functional difficulty. These findings suggest a negative relationship between migration experience and later life health. Research limitations/implications Although we collected health outcome measures after the measurement of explanatory and control measures—a unique strength of this study—we were unable to control for baseline health outcomes. Also, due to the lack of time-varying measures of household socioeconomic status in the survey, this investigation was unable to control for measures associated with the economic prosperity hypothesis. Future research is necessary to develop panel data with appropriately timed measures. Practical implications The findings provide important insights that may help shape individual's and their family's migration decisions. Originality/value This research provides important insight to individuals lured by potential short-term economic prospects in destination places, as well as to scholars and policy makers from migrant-sending settings that are grappling with skyrocketing medical expenses, rapid population aging, and old age security services.
In Situ Deformation Characterization of Density-Graded Foams in Quasi-Static and Impact Loading Conditions

Abstract Digital image correlation is utilized to characterize deformation and strain fields developed within the layers of density-graded multilayered foam structures subjected to uniaxial quasi-static and dynamic compression. Three-layered graded structures fabricated from rigid polyurethane foams with nominal densities of 160, 240, and 320 kg/m3 are subjected to quasi-static and dynamic loading. The quasi-static measurements show that, irrespective of the loading direction, the densification is initiated in the lowest density layer and propagates into other layers later once the first layer is fully densified. The deformation mechanisms are different in the case of dynamic loading conditions than quasi-static loading. In the case of dynamic loading, the deformation mechanism depends on the sample orientation relative to the direction of the applied load. In cases where the higher density layers are impacted, the propagation of the elastic and compaction waves leads to partial deformation of the lowest density layer. Sample deformation continues in all layers upon the reflection of the stress waves from the distal end of the sample. A completely different deformation response is observed in cases where the lowest density layer is oriented towards the impact face. A detailed full-field analysis of strain and stress is performed. The mechanisms associated with the formation and propagation of stress waves from the impact end to the samples' distal end are discussed.
Neural Networks: Applications in Biomedical Engineering

This paper provides a brief survey of artificial neural networks and their applications. The paper also describes the structure and the training algorithms of some of the most commonly used neural networks and their applications. Neural structures covered in this paper include multilayer sigmoid neural networks, Hopfield networks, radial basis functions, and self-organizing maps. Finally, some specific applications of neural networks in different fields of biomedical engineering are described. Keywords: neural networks; perceptron; backpropagation; self-organizing map; hopfield networks; radial basis function networks; pattern recognition; multilayer sigmoid neural networks
The Algebraic Complexity of Shortest Paths in Polyhedral Spaces

In this paper we show that the problem of finding the shortest path between two points in Euclidean 3-space, bounded by a finite collection of polyhedral obstacles, is in general not solvable by radicals over the field of rationals. The problem is shown to be not solvable even for the case when only two obstacle edges are encountered in the shof[est path in 3-space. One direct consequence of the non-solvability by radicals is that for the shortest path problem there cannot exist an exac:t algorhhm under models of computation where the root of an algebraic equation is obtained using arithmetic operations and the extraction of err roots. This leaves only numerical or :;ymbolic approximations to the solutions, where the complexity of the approximations is primarily a function of the algebraic degree of the optimum solu~ tion. For special relative orientations of the polyhedral obstacles however the shortest path is ShOWll to be straight-edge and compass constructible. Simple polynomial time exact algorithms are known for such cases. The Algebraic Complexity of Sbortest Paths in P.:JLy:J.edral Spnt:c~
The Meanings of “Open Communication” Among Couples Coping With a Cardiac Event

The value placed on open communication is an ideology in U.S. American discourse. It has particular urgency among couples coping with a cardiac event, who are often advised that open communication can enhance recovery, bolster individual coping, and sustain relational satisfaction. Our interpretive analysis of 41 interviews with cardiac patients and partners explored the connection between a widespread ideology of openness and varied ways of enacting it that included apparently contradictory practices. Our findings raise questions about interventions designed to change couples' communication, expand concepts and theories of open communication, and suggest developments in the ideology of openness.
THE SYSTEM OF RELEVANCES AND THE POLITICS OF LANGUAGE IN CANADIAN PUBLIC POLICY FORMATION: THE CASE OF BROADCASTING

A l f red Schutz, wr i t ing i n 1955, argued tha t successful mmunication is possible only between persons, social groups, tions, etc., who share a substantial ly similar system o f relevances. le greater the differences, the fewer the chances for successful mmunication. Complete dispar i ty makes discourse impossible. "To successful, any communicative process must, therefore, involve a t o f common abstractions o r standardizations." (Schutz, 1955, 197)
Copyrighting Stage Directions and the Constitutional Mandate to 'Promote the Progress of Science'

In today's theatre industry, copyright law protects the contributions of two main players - the original playwrights and the production companies that secure rights from the playwrights to publicly perform the dramatic work for a period of time. The highly collaborative nature of the theatre stands in sharp contrast to most other forms of performing arts. This collaboration, however, has increasingly spawned a desire by additional players, stage directors in particular, to assert and secure copyrights in their contributions to the dramatic works. In recent cases, stage directors have argued that their creative input, when sufficiently substantial and distinct from the underlying play, requires recognition and compensation when intentionally appropriated by directors, producers, or others. The directors, through their union, the Society of Stage Directors and Choreographers, deny that these actions in any way make claims against playwrights or their royalties or other income. To the playwrights, however, these are empty words. In their eyes, a director's copyright represents a drastic limitation to their ability to exercise control over the work they create and would undermine the spirit of trust and openness which is essential to the collaborative process. The present statutory scheme for seeking copyright protection does not permit the courts to make a case-by-case application of the constitutional mandate that Congress promote the progress of science when exercising its constitutional power to issue copyrights. While the Court recognizes great deference to Congress in fashioning a copyright system, it nonetheless requires that the system comport with this constitutional directive. This Comment shows, however, that Congress' existing scheme may permit copyrights to be issued in situations that frustrate the purpose of this mandate. Fringe cases, like stage directions, should alert Congress to the necessity of clarifying its statutory protection for copyrights in light of this constitutional goal. Protecting copyrights for stage directors would not incentivize new creation by playwrights nor would it encourage the dissemination of existing dramatic works. And so in light of well-crafted arguments that could support a director's copyright under the 1976 Copyright Act, Congress should amend the Act to be clear that the promote the progress language presents a limit to granting copyrights that cannot be exceeded. Such an amendment presents the best option for addressing peripheral works like stage directions and guarantees that constitutional limitations assert their due force.
Magnetic States in Nanostructured Manganese-Intercalated TaS2

Abstract Nanostructured TaS2 with different concentrations of intercalated Mn ions has been investigated using ac and dc magnetization measurements. The nanostructures are composed of tapes that are less than a micron wide, which themselves are comprised of tubular structures with an average diameter of about 100 nm. The sample with a concentration x=0.15 of Mn exhibited a transition from paramagnetism to a cluster glass state at approximately 8 K. The dynamics of this cluster glass state was better described by the Vogel–Fulcher–Tammann law than by critical slowing down, which suggests that the transition is not a continuous one. The cluster glass state exhibited aging-related memory, which is typically observed in canonical spin glasses and superspin glasses. The sample with x=0.23 underwent a paramagnetic to ferromagnetic transition at 85 K. Nonlinear susceptibility measurements suggest that there is another transition close to but somewhat lower than 85 K. With a small measuring field, both zero-field-cooled and field-cooled magnetizations exhibit peaks and dramatic downturns at low temperatures. The field-cooled magnetization also exhibits temperature hysteresis. The unusual behavior of the field-cooled magnetization is due to relaxation and cooling-rate effects. The overall behavior of nanostructured MnxTaS2 possesses the hallmarks of competition between clustered magnetic ground states in a disordered magnetic system.
Mass distributions in various nuclear collisions

The cluster size distributions in proton-nucleus collisions and in nucleus-nucleus collisions are discussed using a simple exactly soluble model. These distributions can be characterized by a single parameter involving volume, temperature, binding energy, and level density effects. As this parameter varies, the shape of the distribution of cluster size changes. Good agreement is found between a simple theoretical prediction and experiment.
Assessment of the long-term effects of primary radiation. Therapy for brain tumors in children

One-hundred-twelve children with primary brain tumors received definitive radiotherapy between the years 1958--1979. Sixty-nine patients were alive at intervals of 1--21 years. Thirty-eight patients underwent neurologic and endocrine evaluation, psychologic and intelligence testing, and assessement for second malignancy post-treatment. A second intracranial malignancy developed in one child, for an incidence of 1.6%. Performance status was good to excellent in 89% of the patients studied. Seventeen percent of the group were mentally retarded. Behavioral disorders were identified in 39% of the patients, 59% of the mothers, and 43% of the fathers. Of the 23 patients with nonparasellar tumors, six were found to have growth hormone deficiency, including two patients with panhypopituitarism. Disability was related to age under 3 years at the time of treatment and tumor extension to the hypothalamus.
Matrix Management in Practice in Access Services at the NCSU Libraries

The former Associate Head of Access and Delivery Services of the North Carolina State University Libraries reports on successful use of matrix management techniques for the Circulation and Reserves unit of the department. Despite their having fallen out of favor in much of the management literature, matrix management principles are useful for managing large access services departments involving a large staff and multiple supervisors on differing shifts. In implementing a matrix structure, the greatest challenges proved to be communication and transparency.
Cleavage of E-cadherin: a mechanism for disruption of the intestinal epithelial barrier by Candida albicans.

To investigate how intestinal epithelial cells respond to contact with Candida albicans , an organism able to invade the bloodstream via the gastrointestinal tract, we focused on the junction proteins occludin, E-cadherin, and desmoglein-2. The levels of these 3 junction proteins were reduced in lysates of human intestinal epithelial monolayers (Caco-2) after a 24-h inoculation with C. albicans , compared with lysates from Saccharomyces cerevisiae -inoculated monolayers. Treatment with pepstatin A did not change the effect of C. albicans on full-length occludin, desmoglein-2, and E-cadherin; however, pepstatin A enhanced the accumulation of a 35-kDa fragment derived from the intracellular portion of E-cadherin. This 35-kDa fragment also accumulated in the presence of γ-secretase inhibitors. These observations suggest that enhancement of E-cadherin cleavage by C. albicans generates an intracellular E-cadherin fragment that can serve as a substrate for γ-secretase. An 89-kDa extracellular fragment of E-cadherin was detected in supernatants of C. albicans -inoculated monolayers; this cleavage event was insensitive to both pepstatin A and γ-secretase inhibitors. Transepithelial electrical resistance, a measure of monolayer integrity, decreased significantly and synchronously with increased generation of the 89-kDa extracellular E-cadherin fragment. Cleavage of E-cadherin may destabilize the homotypic interactions between adjacent epithelial cells and could contribute to loss of monolayer integrity. These experiments identify 2 E-cadherin cleavage events that are enhanced by contact with C. albicans : an intracellular cleavage event that generates a substrate for γ-secretase and an extracellular cleavage event that is temporally associated with an increase in monolayer permeability.
Presence and Prognostic Significance of Melanoma-Associated Antigens CYT-MAA and HMW-MAA in Serum of Patients with Melanoma

With the goal of finding serological markers to monitor patients with early- as well as late-stage melanoma, we compared the levels of the cytoplasmic melanoma-associated antigens (CYT-MAA) and high-molecular-weight melanoma-associated antigen (HMW-MAA) in the sera of melanoma patients and controls. Using double-sandwich ELISA, we measured levels of both antigens in 117 patients and in 62 age- and sex-matched controls. Patients were stratified into four risk group based on stage of the disease. Serum levels of both markers were significantly higher in melanoma patients than in controls. CYT-MAA was the more sensitive marker, with 61% of patients showing elevated levels regardless of the stage of disease. HMW-MAA was elevated in 29%. Elevated CYT-MAA was also significantly correlated with poorer clinical outcome. By multivariate analysis (adjusting for stage and age), patients who had elevated CYT-MAA were 81% more likely to recur than patients with undetectable levels (hazard ratio=1.81, 95% CI=[1.07, 3.06], p-value=0.03). Elevated levels of HMW-MAA did not correlate with poor prognosis. These results suggest that both CYT-MAA and HMW-MAA are serum markers for residual melanoma in patients with resected disease. Furthermore, CYT-MAA appears to be a prognostic marker of clinical outcome in melanoma vaccine-treated patients.
Replacement as a Problem for the Justification of Preventive Detention

What makes Don E. Scheid's article on indefinite detention interesting is that he thinks through many of the moral issues inherent in attempting to prevent (or, rather, keep to a minimum) certain k...
ABERRANT ORIGIN OF THE CRANIAL CRUCIATE LIGAMENT MIMICKING AN OSTEOCHONDRAL LESION RADIOGRAPHICALLY: A CASE HISTORY REPORT

An aberrant cranial cruciate ligament mimicked an osteochondral lesion of the lateral femoral condyle in a young dog. This rare condition was diagnosed at surgery. At a four-year follow-up, no radiographic evidence of the apparent osteochondral defect was seen.
YO!—a time-of-arrival receiver for removal of helicity-correlated beam effects

Abstract A parity violation experiment, G 0 , at Jefferson Lab is sensitive to arrival time differences, at the target, of electron beams in the two helicity states. Instead of the Jefferson Lab standard 499 MHz beam structure, G 0 uses a 31.1875 MHz structure where only 1 out of 16 microbunches contains electrons. Photon counters triggered by time-of-arrival at the target mandate that timing must be independent of delays associated with different orbits taken by the electrons in two helicity states. Corrections to the parity violating asymmetries due to any arrival time differences require the generation of a clean 31.1875 MHz trigger signal and phase matching this signal to the beam's arrival at the target. The time of arrival receiver, named the YO! receiver, has 10 kHz output bandwidth which is sufficiently larger than the settling time (500 μs) of the ≈30 Hz helicity flip. This enables the correction of each helicity bin for any orbit-induced timing inequalities. The device combines conventional receiver and DSP techniques for maximum sensitivity, bandwidth and flexibility and eliminates the 2 π / n phase shifts associated with frequency dividers by means of a sampling phase detection scheme. This paper describes the performance of this device during bench testing, commissioning and in data taking phase of the experiment.
Evaluation of the variables that affect resolution in delayed extraction MALDI-TOF

Abstract The effects of the various experimental parameters on mass resolution of MALDI-TOF and MALDI with delayed extraction are evaluated using an ion flight simulation program. With this program we are able to examine the effects of initial position, initial velocity, delay time, and ion kinetic energy on the line width of TOF spectra. A description of the model is presented as well as data showing the effects of DE parameters on the arrival time distribution of ions in linear and reflectron TOF mass spectra.
Modelling of thin films via a semiempirical method

Abstract Computer modelling of atomic processes on surfaces and bulk materials has seen great progress in the last decade due to the advent of semiempirical methods. In this work, we extend the scope of these techniques to deal with thin films, an area where the progress in large scale atomistic modelling lags behind similar progress in bulk alloy design and surface structure analysis. These techniques rely on solid theoretical background and provide the computational economy that allows for the treatment of complex problems. We discuss one of these techniques, the BFS (Bozzolo–Ferrante–Smith) method for alloys, and illustrate its application to the problem of thin film formation. In particular, we show modelling results on the formation of binary and ternary films of Ni and Al with either Ti or Cr alloying additions. Differences and similarities with the corresponding ternary bulk alloys are discussed. Radical changes in layer-by-layer composition are observed in both cases. While Ti additions induce the formation of a particular ternary phase close to the (110) surface, Cr additions result in the formation of an α -Cr precipitate close to the surface in addition to the changes in surface composition.