cssi/SciSciGPT-SciSciNet huggingface dataset:
Paleoecological Response of Corals to the End-Triassic Mass Extinction: An Integrational Analysis

The end-Triassic (also Triassic-Jurassic) mass extinction severely affected life on planet Earth 200 million years ago. Paleoclimate change triggered by the volcanic eruptions of the Central Atlantic Magmatic Province (CAMP) caused a great loss of marine biodiversity, among which 96% coral genera were get lost. However, there is precious little detail on the paleoecology and growth forms lost between the latest Triassic extinction and the Early Jurassic recovery. Here a new pilot study was conducted by analyzing corallite integration levels among corals from the latest Triassic and Early Jurassic times. Integration levels in corals from the Late Triassic and Early Jurassic were determined through both the Paleobiology Database as well as from a comprehensive museum collection of fossil corals. Results suggest that in addition to a major loss of diversity following the end-Triassic mass extinction, there also was a significant loss of highly integrated corals as clearly evidenced by the coral data from the Early Jurassic. This confirms our hypothesis of paleoecological selectivity for corals following the end-Triassic mass extinction. This study highlights the importance of assigning simple to advanced paleoecological characters with integration levels, which opens a useful approach to understanding of mass extinction and the dynamics of the recovery.
Trust Among Strangers: Friendly Societies in Modern Britain

In the late eighteenth and early nineteenth centuries, the internal migration of a growing population transformed Britain into a 'society of strangers'. The coming and going of so many people wreaked havoc on the institutions through which Britons had previously addressed questions of collective responsibility. Poor relief, charity briefs, box clubs, and the like relied on personal knowledge of reputations for their effectiveness and struggled to accommodate the increasing number of unknown migrants. Trust among Strangers re-centers problems of trust in the making of modern Britain and examines the ways in which upper-class reformers and working-class laborers fashioned and refashioned the concept and practice of friendly society to make promises of collective responsibility effective - even among strangers. The result is a profoundly new account of how Britons navigated their way into the modern world.
Enhancing Temporal Quality Measurements in a Globally Deployed Streaming Video Quality Predictor

Most successful perceptual video quality assessment models are either frame-based, or perform spatiotemporal filtering or motion estimation to model the temporal aspects of video distortions. While good results are obtained on video quality databases, their increased computational complexity often causes video quality engineers to instead rely on simpler image-based quality algorithms. Towards balancing demands between prediction accuracy and compute efficiency, Netflix developed the Video Multi-method Assessment Fusion (VMAF) Framework, an efficient feature-based system that combines multiple perception-based elementary image measurements to produce video quality predictions. However, the current version of VMAF only weakly captures temporal video features which are sensitive to perceptual temporal video distortions. To this end, we propose an enhanced model we call SpatioTemporal VMAF (ST- VMAF) that incorporates temporal features that are easy to compute. We demonstrate the improved performance of ST- VMAF on many subjective video databases. The proposed model will be made available as part of the open source package in https://github.com/Netflix/vmaf.
Natural signs

A description of natural signs and natural information is proposed that interprets the presence of natural information as an affordance for the particular animal or species that would interpret it. This solves the reference class problem that undercuts earlier correlational accounts. It explains how there can be natural signs of individuals and also various non-correlational signs. The effect of superimposition of natural signs is then described.
Development - Editorial overview

The purpose of neural development is to assemble functional circuits that control behavior, a process that requires both the proper specification of neuronal identities and the establishment of appropriate patterns of connectivity between distinct neuronal subtypes. Given the vast number of neurons in the brain, the even larger number of specific connections, and the relatively small number of genes, the problem of how to accomplish this appears daunting. Nevertheless, considerable progress has been made over the past several years in deciphering a number of the general cellular and molecular mechanisms that are used to assemble the nervous system. This issue of Current Opinion in Neurobiology focuses primarily on the problems of neuronal identity specification and circuit formation, as they relate both to early development and to the emergence of complex behaviors. We have endeavored to strike a balance between providing updates on fast-moving fields of central importance and including areas that received relatively less coverage in the review literature but that are emerging as exciting new frontiers. The result is a somewhat idiosyncratic and certainly noncomprehensive collection of reviews that reflects our own biased perceptions of what is interesting. Consequently, there are major areas and approaches not represented, with our chief sin of omission being the absence of reviews explicitly focused on invertebrate genetic systems; however, several of the reviews draw on insights provided by such systems, and many of the advances in vertebrate neural development derive from concepts originally revealed in Drosophila. For the purposes of this overview, we have divided the reviews into four groups. The first group deals with neurogenesis, the diversification of neurons and muscles, and some aspects of patterning. The second group concerns the mechanisms that guide the selection of targets by growing axons. The third group surveys the relative contributions of electrical activity and neurotrophins to circuit formation. Finally, the fourth group deals with the role of social interactions between animals and its influence on the development of learned behaviors.
Ex vivo pregnant‐like tissue model to assess injectable hydrogel for preterm birth prevention

Cervical insufficiency is an important cause of preterm birth, which leads to severe newborn complications. Standard treatment for cervical insufficiency is cerclage, which has variable success rates, resulting in a clinical need for alternative treatments. Our objective was to develop an ex vivo model of softened cervical tissue to study an injectable silk-based hydrogel as a novel alternative treatment for cervical insufficiency. Cervical tissue from non-pregnant women was enzymatically treated and characterized to determine tissue hydration, collagen organization, and mechanical properties via unconfined compression. Enzymatic treatment led to an 86 ± 7.9% decrease in modulus which correlated to a decrease in collagen organization as observed by differences in collagen birefringence. The softened tissue was injected with a crosslinked silk-hyaluronic acid composite hydrogel. After injection, the mechanical properties and volume increase of the hydrogel-treated tissue were measured resulting in a 54 ± 16% volume increase with minimal effect on tissue mechanical properties. In addition, cervical fibroblasts on silk-hyaluronic acid hydrogels remained viable and exhibited increased proliferation and metabolic activity over 5 days. Overall, this study developed an ex vivo pregnant-like human tissue model to assess cervical augmentation and showed the potential of silk-based hydrogels as an alternative treatment for cervical insufficiency.
Der Augenblick des Übergangs

Dass das Interesse an einer Vorstellung vom Epochenwechsel in jungster Zeit so explosionsartig zugenommen hat, lasst sich recht exakt mit dem Erscheinen eines einzigen Aufsatzes festmachen. Mit dem Namen Paul Crutzen verband man bereits den Nobelpreis, als er im Jahr 2000 zusammen mit dem Meeresokologen Eugene Stoermer erstmals die Behauptung aufstellte, der Einfluss der Menschen fuhre insgesamt zu einem Ende des Holozan. Crutzen und Stoermer gingen der Frage nach, in welchem Ausmas Menschen die Erde mit ihren biologischen und geophysikalischen Systemen verandert haben, und gelangten zu dem Schluss: „Uns erscheint es mehr als angemessen, auf die zentrale Rolle der Menschheit in Geologie und Okologie hinzuweisen, indem wir vorschlagen, fur die derzeitige geologische Epoche den Begriff ‚Anthropozan‘ zu verwenden.“1
Predicting Onset of Dementia in Parkinson's Disease Patients

Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative disorders in humans. Because a significant percentage of patients have clinical and pathological features of both diseases, it has been hypothesized that the patho-cascades of the two diseases overlap. Despite this evidence, these two diseases are rarely studied in a joint manner. In this paper, we utilize clinical, imaging, genetic, and biospecimen features to cluster AD and PD patients into the same feature space. By training a machine learning classifier on the combined feature space, we predict the disease stage of patients two years after their baseline visits. We observed a considerable improvement in the prediction accuracy of Parkinson's dementia patients due to combined training on Alzheimer's and Parkinson's patients, thereby affirming the claim that these two diseases can be jointly studied.
Impact of insurance on survival in patients < 65 with head & neck cancer treated with radiotherapy.

OBJECTIVES The United States has a heterogenous health insurance landscape for patients <65 years. We sought to characterise the impact of primary payer on overall survival (OS) in insured patients younger than 65 with head and neck squamous cell carcinoma (HNSCC) treated with definitive radiotherapy. DESIGN/STUDY/PARTICIPANTS The National Cancer Database was queried for patients <65 years old diagnosed from 2004 to 2014 undergoing definitive radiotherapy ± chemotherapy for cancers of the nasopharynx, oropharynx, hypopharynx and larynx. Uninsured patients and oropharyngeal cancers without known HPV status were excluded. MAIN OUTCOME Overall survival. RESULTS Overall, 27 292 insured patients were identified, including 17 060 (62.5%) with private insurance. Median follow-up was 52.1 months. In multivariable models, patients receiving Medicaid (HR = 1.66, 95% CI 1.57-1.75, P < .001), Medicare (HR = 1.64, 95% CI 1.55-1.73, P < .001) and other government insurance (HR = 1.44, 95% CI 1.29-1., P < .001) had independently increased mortality in comparison to those with private insurance. In propensity score-matched cohorts, 5-year OS was 65.5% vs 50.6% for privately vs government-insured patients, respectively (P < .001). In multivariable subgroup analysis, private insurance was associated with improved survival in all subgroups. However, the magnitude of this effect was most pronounced in patients with HPV-positive oropharyngeal cancer vs non-HPV-related cancer (interaction P < .001), younger patients (interaction P = .001), and those without comorbidity (interaction P < .001). CONCLUSIONS Patients <65 with HNSCC undergoing definitive radiation with private health insurance have markedly longer survival relative to patients with government-sponsored insurance. This illustrates that increasing access to care may be necessary, but is not sufficient, to mitigate the significant disparities in the US healthcare system.
Attitudes to Technology: Part 1

Automation tends to be partial rather than complete, automating tasks rather than entire professions. Partial automation can also cause increases in employment in the affected industries, as well as decreases. Nevertheless, it will still cause disruption in the near term, since it requires people to learn new skills in order to remain employed. In deciding whether automation creates or destroys jobs, the decisive factor is demand rather than technology.
Emergency Medical Services resource capacity and competency amid COVID-19 in the United States: preliminary findings from a national survey.

Abstract Objective This study aimed to investigate available resources, Personal Protective Equipment (PPE) availability, sanitation practices, institutional policies, and opinions among EMS professionals in the United States amid the COVID-19 pandemic using a self-report survey questionnaire. Methods An online 42-question multiple choice survey was randomly distributed between April 1, 2020, and April 16, 2020 to various active Emergency Medical Services (EMS) paid personnel in all 50 U.S. states including the District of Columbia (n = 192). We approximate a 95% confidence interval (±0.07). Results An overwhelming number of EMS providers report having limited access to N95 respirators, receiving little or no benefits from COVID-19 related work, and report no institutional policy on social distancing practices despite CDC recommendations. For providers who do have access to N95 respirators, 31% report having to use the same mask for 1 week or longer. Approximately ⅓ of the surveyed participants were unsure of when a COVID-19 patient is infectious. The data suggests regular decontamination of EMS equipment after each patient contact is not a regular practice. Discussion Current practices to educate EMS providers on appropriate response to the novel coronavirus may not be sufficient, and future patients may benefit from a nationally established COVID-19 EMS response protocol. Further investigation on whether current EMS practices are contributing to the spread of infection is warranted. The data reveals concerning deficits in COVID-19 related education and administrative protocols which pose as a serious public health concern that should be urgently addressed.
Disruption of the nectin-afadin complex recapitulates features of the human cleft lip/palate syndrome CLPED1

Cleft palate (CP), one of the most common congenital conditions, arises from failures in secondary palatogenesis during embryonic development. Several human genetic syndromes featuring CP and ectodermal dysplasia have been linked to mutations in genes regulating cell-cell adhesion, yet mouse models have largely failed to recapitulate these findings. Here, we use in utero lentiviral-mediated genetic approaches in mice to provide the first direct evidence that the nectin-afadin axis is essential for proper palate shelf elevation and fusion. Using this technique, we demonstrate that palatal epithelial conditional loss of afadin (Afdn) - an obligate nectin- and actin-binding protein - induces a high penetrance of CP, not observed when Afdn is targeted later using Krt14-Cre We implicate Nectin1 and Nectin4 as being crucially involved, as loss of either induces a low penetrance of mild palate closure defects, while loss of both causes severe CP with a frequency similar to Afdn loss. Finally, expression of the human disease mutant NECTIN1W185X causes CP with greater penetrance than Nectin1 loss, suggesting this alteration may drive CP via a dominant interfering mechanism.
Informal Strategies for Risk Assessment Among Brazilian Male Sex Workers and Their Clients

Sexually transmitted infections have always been a threat for both sex workers and their clients. This issue has become more prominent, however, since the early 1980s when HIV surfaced as an incurable and life-threatening virus. Studies on safer sex and male sex work have examined many topics but few studies have done so from the perspectives of both sex workers and their clients. In this article, we examine strategies used by both parties for risk assessments in Brazilian termas (saunas). We analyzed 45 in-depth interviews conducted between 2010 and 2014. All participants are or have been sex workers and or their clients. We used a grounded theory approach which allows themes and issues that participants deemed important to emerge in analyzing the data. The results of this exploratory study suggest that sex workers and their clients in Brazil attempt to make risk assessments even though their methods are not scientific or necessarily reliable. Three common strategies engaged by both parties include playing defensive, relying on visual verification, and using gossip as a source of information. In the absence of immediate and reliable source of information to aid risk assessment, these are some of the strategies they can use at the site of interaction to make their best informed decision on with whom to transact and what the transaction should entail. An often under-examined source of information is the role of gossips or small talk among clients, among sex workers and between sex workers and clients.
Scale bridging materials physics: Active learning workflows and integrable deep neural networks for free energy function representations in alloys

Abstract The free energy plays a fundamental role in theories of phase transformations and microstructure evolution. It encodes the thermodynamic coupling between different fields, such as mechanics and chemistry, within continuum descriptions of non-equilibrium materials phenomena. In mechano-chemically interacting materials systems, even consideration of only compositions, order parameters and strains results in a free energy description that occupies a high-dimensional space. Scale bridging between the electronic structure of a solid and continuum descriptions of its non-equilibrium behavior can be realized with integrable deep neural networks (IDNN) that are trained to free energy derivative data generated by first-principles statistical mechanics simulations and then analytically integrating to recover a free energy density function. Here we combine the IDNN with an active learning workflow to ensure well-distributed sampling of the free energy derivative data in high-dimensional input spaces, thereby enabling true scale bridging between first-principles statistical mechanics and continuum phase field models. As a prototypical material system we focus on Ni–Al. Cahn–Hilliard and Allen–Cahn phase field simulations using the resulting IDNN representation for the free energy density of Ni–Al demonstrate that the appropriate physics of the material have been learned. This work advances the treatment of scale bridging, starting with electronic structure calculations and proceeding through statistical mechanics to continuum physics. Its coupling of Cahn–Hilliard and Allen–Cahn phase field descriptions with nonlinear elasticity through the free energy density ensures a rigorous treatment of phase transformation phenomena.
A Framework of Motoric Complexity: An Investigation in Children With Typical and Impaired Speech Development.

Introduction The current work presents a framework of motoric complexity where stimuli differ according to movement elements across a sound sequence (i.e., consonant transitions and vowel direction...
Monitoring of Anticoagulant Therapy

Anticoagulant and antiplatelet medications are widely used in the prevention and treatment of thromboembolism. For many years, the antithrombotic therapeutic armamentarium was limited essentially to heparin, warfarin, and aspirin, but over the past several years the number of medications has increased substantially, with a consequent demand for better understanding of the laboratory aspects of therapeutic monitoring.
Exploring the Role of Communication Competence in Abusive Supervision: A Test of a Model Linking Downward Communicative Adaptability to Downward Abusive Communication

In this article, we propose and test a model of downward abusive communication. According to the model, a superior’s display of abusive communication toward his or her subordinates is caused by a lack of downward communicative adaptability. Superiors from various organizations completed an online survey, which measured their downward communicative adaptability and downward abusive communication. The results of a regression analysis provided support for the model. We conclude the article with a discussion of the practical and theoretical implications of our findings.
A Field Study on the Acceptance and Use of a New Accounting System

ABSTRACT: This study examines the attitudes, use, and acceptance of a new accounting system in a pharmaceutical corporation that switched from an activity-based costing system to the Theory of Constraints System (TOC). Using structuration theory as a framework to understand the dynamics of the change process, we posit that user responses and attitudes toward TOC are influenced not only by the technical features of the system and the potential economic benefits, but also by the fit between TOC and existing structures, modes of mediation, and agency of the users' environment. When users interact with TOC on an ongoing basis, they form interpretations of the new system, and, based on such interpretations, they exhibit actions with respect to the use of TOC ranging from championship to rejection of the system. We explore cross-sectional variations in the use of the system and link such variations to the practical features of the new system, as well as the social structures of the users' environments.
Indirectly Detected DNP-Enhanced 17O NMR Spectroscopy: Observation of Non-Protonated Near-Surface Oxygen at Naturally Abundant Silica and Silica-Alumina

Recent studies have shown that dynamic nuclear polarization (DNP) can be used to detect 17 O solid-state NMR spectra of naturally abundant samples within a reasonable experimental time. Observations using indirect DNP, which relies on 1 H mediation in transferring electron hyperpolarization to 17 O, are currently limited mostly to hydroxyls. Direct DNP schemes can hyperpolarize non-protonated oxygen near the radicals; however, they generally offer much lower signal enhancements. In this study, we demonstrate the detection of signals from non-protonated 17 O in materials containing silicon. The sensitivity boost that made the experiment possible originates from three sources: indirect DNP excitation of 29 Si via protons, indirect detection of 17 O through 29 Si nuclei using two-dimensional 29 Si{ 17 O} D -HMQC, and Carr-Purcell-Meiboom-Gill refocusing of 29 Si magnetization during acquisition. This 29 Si-detected scheme enabled, for the first time, 2D 17 O- 29 Si heteronuclear correlation spectroscopy in mesoporous silica and silica-alumina surfaces at natural abundance. In contrast to the silanols showing motion-averaged 17 O signals, the framework oxygens exhibit unperturbed powder patterns as unambiguous fingerprints of surface sites. Along with hydroxyl oxygens, detection of these moieties will help in gaining more atomistic-scale insights into surface chemistry.
Effect of pretreatment central adiposity on the cardiometabolic risk of male germ cell tumor survivors after cisplatin-based chemotherapy.

5019Background: Preferential fat accumulation in the visceral compartment (i.e. central adiposity) increases cardiovascular risk in the general population independent of body mass index (BMI). We i...
Molten Salt Based Nanofluids for Solar Thermal Power Plant: A Case Study

This work presents the effect of using molten salt-based nanofluids for performance enhancement of Concentrated Solar Power (CSP) plant. The study is carried out in the context of Pakistan, a country that has been struggling with energy crises for a very long time. Previously, it has been shown that a CSP plant in Pakistan is a feasible option. This paper aims to find an optimal combination of nanoparticles and molten salt for a CSP plant in Pakistan. The selected site Nara desert, Nawabshah in the province of Sindh receives an annual direct normal irradiance of 1955 kWh/m2. A 100 MW Parabolic Trough Collector (PTC) plant is modeled using the System Advisor Model (SAM) and is integrated with thermal energy storage of up to 10 hours. The model is validated by comparing results with commercial-scale plants. From literature, nanoparticles with the highest share of usage in performance enhancement of PTC collectors (CuO, Al 2 O 3 , and TiO 2 ) with different fractions are selected and Hitec Solar Salt is considered as the base fluid. Parametric optimization is carried out for each of the working fluids. The performance is compared based on annual power generation, capacity factor, plant efficiency, and required Thermal Storage volume. The comparison shows that by using nanofluids, the annual power generation, capacity factor, and efficiency are increased by 8.86%, 8.88%, and 8.9% respectively, whereas the volume of thermal storage is reduced by 36.02%. The optimal fraction of nanoparticles is found to be 1%, 2%, and 5% for CuO, Al 2 O 3 , and TiO 2 , respectively.
Students’ Level of Satisfaction and Their Technological Proficiency Growth in Teacher Education Coursework

Teachers are increasingly expected to demonstrate frequent use of and proficiency with educational technologies in the classroom. Meanwhile, teacher experiences with new technologies prior to their entry into the classroom do not always match these expectations. For many teacher education programs, the solution to this challenge lies in the incorporation of educational technologies into coursework for pre-service teachers (PSTs). This study examines PST reported uses and proficiency with educational technologies before and after taking introductory educational coursework. Based on surveys administered at the beginning and end of introductory education courses, the study found that PSTs reported consistent improvement in their technological skills. There were also positive relationships among skills competence and PST outcomes of satisfaction, effectiveness, and usefulness. These findings support existing efforts to incorporate educational technology into teacher certification coursework, while also suggesting ways to expand on these approaches to better support PSTs experience with educational technologies.
Description of on-farm treatment compliance and risk factors for culling in sows.

BACKGROUND In commercial pig farming, sick or injured sows are often treated by producers or hired staff. To date, limited quantitative data exists on treatment compliance and the possible effect on sow longevity post-treatment. The objective of the study was to quantify on-farm compliance of treatment selection, frequency, and dosage, as well as to investigate the association between body condition scores (BCS) and other sow-level factors on post-treatment cull risk. RESULTS On-farm treatment records, including culling reason or reason of death up to 6 months post-treatment, production records and sow characteristics were obtained for 134 sows over an 8-week period. Treatment compliance was based on the accuracy of recorded treatments compared to the herd veterinarian's established treatment guidelines. Univariable and multivariable logistic regression models including treatment reason, treatment compliance, BCS, parity, production stage and production metrics, were constructed to investigate associations between those variables and sow culling or death. This study found low compliance for on-farm sow treatment protocols, with only 22.4% (30/134) of the sows receiving correct and complete treatment during the duration of the study. No effect of individual treatment components (drug, dosage, or frequency) on sow culling was observed. A trend for an interaction between treatment compliance and BCS was found, and parity and number of piglets born alive were identified as predictors for sow maintenance in the herd. CONCLUSIONS On-farm sow treatment compliance was low, resulting in that approximately 80% of the enrolled sows were not treated according to existing guidelines. Non-compliance of treatment guidelines did not seem to affect the risk of culling in treated sows but may have prolonged any associated pain, recovery time and negatively impacted the sow welfare during that time period.
The recognition of moral issues: moral awareness, moral sensitivity and moral attentiveness

In this brief review, we discuss foundational and recent research on the recognition of moral issues, an area generally referred to as moral awareness. Scholarly work in this area primarily focuses on three constructs: moral awareness, moral sensitivity, and moral attentiveness. Recent research on the antecedents of moral recognition has identified several biological, psychological, and socio-cultural factors; while research on the consequences of moral recognition is further validating the claims of the foundational theories on the topic. After discussing this recent work in some detail, we point to issues within the field that demand more scholarly attention.
SiC monofilament-reinforced Si3N4 matrix composites

Introduction Despite the significant advances made in recent years in processing struc- tural ceramics, such as Si3N4 and Sic, with excellent high-temperature strength and uniformity of strength (high Weibull modulus), their relia- bility in high-performance applications is still in doubt. This concern over reliability can be attributed to their low fracture toughness and resulting susceptibility to brittle fracture, especially from flaws developed in serv- ice by contact damage. Increasing attention is now being directed to ceramic-matrix composites wherein fiber reinforcement is viewed primari- ly as a means of increasing fracture toughness and, hence, reliability.'** Fiber-reinforced ceramics offer the potential advantages of increased reli- ability with adequate high-temperature strength, creep and oxidation re- sistance, requirements generally sought in a structural ceramic. Fiber reinforcement, in principle, can be employed for both strengthening and toughening a brittle matrix.3 This principle has been most successfully demonstrated in unidirectional, continuous-fiber com- posites with cement, glass, or glass-ceramic matrices, i.e., low-modulus matrices that can be processed at relatively low These composites fail by the multiple matrix-cracking mode in which the rein- forcing fibers limit the crack-face displacements and, thus, contribute to both an enhancement of strength and fracture to~ghness.~*'~ Another important aspect of the matrix-cracking failure mode is that the cracking stress is insensitive to initial flaws in a wide-size range and, thus, the com- posites are resistant to strength degradation from contact damage.
Byron in Baghdad

Forgive me, Lord, for all that is to come. Humility isn't easy. I am a product of my age, and your rima's not for me. Rhyme Royale's too much too. (I sought constraint before. The work remains, as yet, unknown to most, though findable on the Net.) We post-Postmodernist Americans like meals pre-cooked, in someone else's pans, swallowing a lot; but since we're not chewers, I'll honor "English Bards and Scotch Reviewers." (The name hangs from my lips as from a dog's, the deadest thing dug up, but my tail wags....) We've been sound-bit, and couplets might well suit these epitaphic days of ab and glute.
Sex and Violence

Conceiving Sexuality: Approaches to Sex Research in a Postmodern World. Richard G. Parker and John H. Gagnon Sex and Violence: Issues in Representation and Experience. Penelope Harvey and Peter Gow
AR1-5 AND AR2-6 ARYL PARTICIPATION IN IONIC AND FREE RADICAL PROCESSES

Die Beteiligung von Arylgruppen in Solvolysen von 4-Aryl-1-butylhalogeniden und Arylsulfonaten sowie in Reaktionen von freien 4-Aryl-1-butyl-radikalen wird diskutiert. Bei geeignet methoxylierten oder hydroxy-lierten 4-Aryl-1-butylverbindungen kann die Formolyse entweder mit Ar1-5-oder Ar1-6-Arylbeteiligung verlaufen. Dies fuhrt zur Bildung von Tetralin. Da bei Ar1-5-Beteiligung ein Spirocarboniumion entsteht, in welchem entweder Cα oder Cδ der ursprunglichen Butylseitenkette wandern kann, ist es moglich, dass ein anderes Tetralin geformt wird als auf dem direkteren Ar2-6-Weg. Als Beispiel dient die Formolysenreaktion von 4-p-Anisyl-4-methyl-1-pentylbrombenzolsulfonat.
Toroidal gyrofluid equations for simulations of tokamak turbulence

A set of nonlinear gyrofluid equations for simulations of tokamak turbulence are derived by taking moments of the nonlinear toroidal gyrokinetic equation. The moment hierarchy is closed with approximations that model the kinetic effects of parallel Landau damping, toroidal drift resonances, and finite Larmor radius effects. These equations generalize the work of Dorland and Hammett [Phys. Fluids B 5, 812 (1993)] to toroidal geometry by including essential toroidal effects. The closures for phase mixing from toroidal ∇B and curvature drifts take the basic form presented in Waltz et al. [Phys. Fluids B 4, 3138 (1992)], but here a more rigorous procedure is used, including an extension to higher moments, which provides significantly improved accuracy. In addition, trapped ion effects and collisions are incorporated. This reduced set of nonlinear equations accurately models most of the physics considered important for ion dynamics in core tokamak turbulence, and is simple enough to be used in high resolution ...
Properties of Rydberg autoionizing states in electric fields

The linear-Stark-effect approximation is employed to investigate the effects of electric fields on autoionizing doubly excited atomic states corresponding to relatively large values of the outer-electron principal quantum number $n$. By assuming that a statistical distribution of the inner-electron magnetic sublevels has been established, simple expressions are derived which relate the autoionization and radiative transition rates in the presence of an electric field to the respective field-free rates. It is pointed out that the multiphoton laser excitation of the doubly excited states can give rise to a nonstatistical distribution of the magnetic sublevels and to complex interference terms involving transition amplitudes associated with different values of the outer-electron angular momentum quantum number $l$. The results of calculations are presented for the autoionization and radiative-transition rates which play the most important role in the dielectronic recombination of the Li-like ${\mathrm{Fe}}^{+23}$ ion through the $2p\ensuremath{\rightarrow}2s$ inner-electron transition, where the contributions from large-$n$ values are particularly important. In these calculations it is assumed that the magnetic sublevels are statistically populated and only the simple expressions for the transition rates are employed. The effects of the electric field on the dominant (inner-electron) radiative decay rate can be neglected, but the electric field mixing of the outer-electron $l$ substates substantially increases the autoionization rates from the higher-$l$ sublevels.
Partial purification of the Na+-dependentd-glucose transport system from renal brush border membranes

A membrane extract enriched with the Na+-dependentd-glucose transport system was obtained by differential cholate solubilization of rat renal brush border membranes in the presence of 120mm Na+ ions. Sodium ions were essential in stabilizing the transport system during cholate treatment. This membrane extract was further purified with respect to its Na+-coupledd-glucose transport activity and protein content by the use of asolectin-equilibrated hydroxylapatite. The reconstituted proteoliposomes prepared from this purified fraction showed a transient accumulation ofd-glucose in response to a Na+ gradient. The observed rate of Na+-coupledd-glucose uptake by the proteoliposomes represented about a sevenfold increase as compared to that of the reconstituted system derived from an initial 1.2% cholate extract of the membranes. Other Na+-coupled transport systems such asl-alanine, α-ketoglutarate and phosphate were not detected in these reconstituted proteoliposomes.
Femtosecond absorption anisotropy of the aqueous solvated electron

Abstract Femtosecond near-infrared pump/visible probe absorption dichroism studies on the aqueous solvated electron are reported. Experiments performed with 300 fs time resolution demonstrate that the anisotropy of the transient absorption observed at 740, 800 and 860 nm is established concomitant with excitation and decays in ≈ 3 ps. This observation is consistent with recent theoretical predictions (B.J. Schwartz and P.J. Rossky, Phys. Rev. Letters (1994), submitted) and demonstrates that anisotropic solvent fluctuations relax on the picosecond timescale. However, the magnitude and spectral manifestations of the absorption anisotropy are not consistent with theory.
Role of Tyrosine Phosphorylation in Radiation-Induced Cell Cycle-Arrest of Leukemic B-Cell Precursors at the G2-M Transition Checkpoint

Here we provide experimental evidence that ionizing radiation induces inhibitory tyrosine phosphorylation of the p34cdc2 kinase in human leukemic B-cell precursors. Herbimycin A markedly reduced tyrosine phosphorylation of p34cdc2 in irradiated leukemic B-cell precursors, thereby preventing radiation-induced cell cycle arrest at the G2-M transition checkpoint. Thus, tyrosine phosphorylation is directly responsible for the inactivation of p34cdc2 in irradiated human leukemic B-cell precursors and activation of protein tyrosine kinases is a proximal and mandatory step in radiation-induced G2-arrest arrest at the G2-M checkpoint. Human WEE1 kinase isolated from unirradiated or irradiated leukemic B-cell precursors had minimal tyrosine kinase activity towards p34cdc2. We detected no increase of human WEE 1 kinase activity after radiation of leukemic B-cell precursors, as measured by (a) autophosphorylation, (b) tyrosine phosphorylation of a synthetic peptide derived from the p34cdc2 amino-terminal region or (...
Time-resolved C2 swan emission from short-pulse UV fragmentation of CO: evidence for two C2 formation mechanisms

Abstract We have studied C 2 Swan (d 3 Π → a 3 Π u ) emission resulting from multiphoton UV excitation of CO. Population of d 3 Π proceeds through distinct early and late processes, the former giving rise only to normal Swan emission. The late process is responsible for v = 6 enhancement (high-pressure bands), and it dominates time-averaged emission in an bands for ⪖ 10 Torr of CO.
Gulf stream ground truth project: Results of the NRL airborned sensors

Results of an airborne study of the waves in the Gulf Stream are presented. These results show that the active microwave sensors (high-flight radar and wind-wave radar) provide consistent and accurate estimates of significant wave height and surface wind speed, respectively. The correlation between the wave height measurements of the high-flight radar and a laser profilometer is excellent.
Possible evidence for the existence of a growth hormone fragment in porcine pituitary

In an attempt to search for growth hormone fragments in the pituitary, a radioimmunoassay was developed for a 55 residue S-amino-ethylated CNBr fragment (fragment B) of porcine growth hormone corresponding to residues 126-180 of human growth hormone. The assay was sensitive to 50 pg of fragment B whereas displacement of 125I-labelled fragment B by procine growth hormone required a 10(3) M excess and was non-parallel. In a homogolous porcine growth hormone radioimmunoassay, fragment B was non-reactive. Gel filtration of an extract of porcine pituitary on Sephadex G-75 revealed three peaks of fragment B immunoreactivity: peak I (29% of total immunoreactivity) eluted in the void volume, peak II (49%) eluted in the position of growth hormone, and peak III (12%) was more retarded than fragment B. Nearly all of the growth hormone immunoreactivity eluted as a single peak in the position of 125I-labelled porcine growth hormone. The dilution curve of peak III but not of peaks I or II was parallel to that of fragment B. The results indicate the existence within porcine pituitary of material cross-reactive with a portion of the growth hormone molecule, possible representing a growth hormone fragment.
Isomers in iodine nuclei.

The feeding and decay patterns of isomers in odd-odd iodine nuclei, produced in heavy-ion fusion-evaporation reactions and separated by a recoil mass spectrometer, have been studied with the \ensuremath{\gamma}-ray spectroscopy technique. A new isomer in $^{116}\mathrm{I}$, fed by a known collective band, was identified and its half-life was measured to be 3.27\ifmmode\pm\else\textpm\fi{}0.16 \ensuremath{\mu}s. An isomer was confirmed to exist in $^{122}\mathrm{I}$ with a measured half-life of 80\ifmmode\pm\else\textpm\fi{}8 \ensuremath{\mu}s in agreement with two previous determinations. It is established from our study that these isomers serve as links between the high-spin and low-spin states in $^{116,122}\mathrm{I}$. The characteristic properties of low excitation energy and high spin of these isomers are evident. As a by-product in the study of $^{122}\mathrm{I}$, the half-life of a known high-spin isomer in $^{121}\mathrm{I}$ was measured to be 16.0\ifmmode\pm\else\textpm\fi{}1.4 \ensuremath{\mu}s, which disagrees with an early measurement of 9.0\ifmmode\pm\else\textpm\fi{}1.5 \ensuremath{\mu}s. Its isomeric transition has an energy of 135 keV as suggested by our data in contrast to the value of 159 keV reported earlier.
Modulation of human lymphocyte marker expression by γ irradiation and mitomycin C

Abstract γ irradiation (GR) or mitomycin C (MC) treatment of stimulator cells is frequently used to achieve unidirectionality of response in the mixed lymphocyte reaction. As GR differs from MC in the pathways used to block lymphocyte replication, this study analyzes the effects of these modalities upon the expression of various differentiation and Class II major histocompatibility antigens on lymphocytes cultured for 24, 48, and 72 hr. There was a decrease in the mean density of HLA-DR expression on CD3+ and on CD8+ cells at 24, 48, and 72 hr after exposure to GR (42 and 35, 60 and 69, and 26 and 49%, respectively) or to MC (26 and 11, 26 and 18, and 46 and 30%, respectively). There was a parallel decrease in the levels of the corresponding cell subsets when compared with control cultured cells not exposed to GR or MC. In contrast, the density of HLA-DR markers on CD3-negative cells was increased at 24, 48, and 72 hr of culture following exposure to GR (73, 82. and 102%, respectively) or to MC (9, 45, and 80%, respectively). There was a more profound decrease in CD3+, CD8+, and CD19+ cell subset levels and in the density of the corresponding markers in GR-treated cells than in those of cells exposed to MC when the results were compared with those of untreated cultured control cells. Although GR appears to exert a more profound effect than MC, the results indicate that both modalities have the capacity to reduce the density of polymorphic determinants on Class II (HLA-D region)-encoded molecules on T (CD3+ and CD8+) and B (CD19+) cells which are known to trigger potent MLR responses. Both modalities may therefore affect profoundly the relative strength of MLC responses and the derived measurements of the degree of HLA Class II compatibility between stimulator and re-Sponder cells.
Growth-promoting effects of progesterone in a human endometrial cancer cell line (Ishikawa-Var I)

Abstract Significant growth responses to progesterone of human endometrial adenocarcinoma cells (Ishikawa-Var I) were observed under in vitro culture conditions. Progesterone affected both the rate of exponential proliferation and cell population densities after the exponential phase. In the presence of the hormone, the doubling time of exponentially proliferating cells was reduced from 44 to 35.6 h and cell densities were increased by as much as 2–3 times over those of controls during approx. 2 weeks in culture. The effects of progesterone on cell population growth were dose dependent. Estradiol (10 −8 M) and testosterone (10 −6 M) did not affect cell densities and the effects of dexamethasone (10 −6 M) were small. In contrast, both progesterone and estradiol stimulated colony formation under anchorage-independent conditions in soft agar. These results suggest the possibility that growth of sensitive cell clones in endometrial tumors could be enhanced in some patients during adjuvant progestin therapy.
Juvenile ossifying fibroma: an ultrastructural study.

The ultrastructural features of a juvenile ossifying fibroma of the maxilla are described. The stromal portion of the tumor was composed of osteoblasts and to a lesser extent of fibroblasts. The bone spicules were rimmed by osteoblasts and osteoclasts. Calcification was seen to occur along the collagen fiber matrix, corresponding to calcification of osteoid, and also in the form of intracellular and extracellular crystallization. The latter form of calcification corresponded to so-called psammoma-like bodies, and was considered characteristic of this subtype of ossifying fibroma. Cancer 42:2668–2674, 1978.
Macrofaunal associations with seagrass epiphytes relative importance of trophic and structural characteristics

Abstract Attached epiphytes often make important contributions to total primary production in seagrass meadows. Additionally, they may increase the spatial complexity of seagrass habitats. Experiments conducted using artificial seagrass units (ASU) manipulated both epiphytic structure and epiphytic food resources. Previous work suggested that the increase in faunal density associated with epiphytes was related to increases in structure, but our results indicate that the primary impact of epiphytes lies in their trophic role. Data showed that epifaunal density was significantly greater in conditioned ASUs fouled with a live community of epiphytes (12 285 individuals m −2 ) compared to ASUs with artificially created epiphytic structure (5099 inds. m −2 ) and to control ASUs (5955 inds. m −2 ). This response to epiphytic trophic resources was significant for most herbivore/omnivore taxa, but not necessarily for filter feeding or predatory epifauna. However, densities of two predatory taxa (fish and mud crabs) were significantly greater where epiphytic biomass was higher, which may reflect their response to increased prey abundance. Additionally, ASUs conditioned with live epiphytes had greater taxa richness than other ASUs. Epiphytic structure appeared to play only a limited role in determining the density of most mobile epifauna, but epiphytic structure appeared to be important in augmenting the settlement of bivalves. By using ASUs we were able to control aspects of blade length and shoot density, but the pre-experiment conditioning of treatments fouled with live epiphytes may have played a role in determining absolute differences in macrofaunal density among ASU treatments. Overall, our work suggests that the trophic role of epiphytes can have a dramatic impact on associated epifaunal communities, although future investigations are needed to assess this relationship more fully.
A Study in the Determination of Phenyl-2-propanone from an Illicit Laboratory Operation

Abstract Phenyl-2-propanone (P-2-P) is the starting material for the synthesis of methamphetamines and related compounds. Easily synthesized, P-2-P is ideal for illegal drug production and, therefore, is a controlled substance in the USA. Procedures were developed for the analysis of P-2-P recovered from a clandestine laboratory operation. Methods studied included: (1) a qualitative and semiquantitative determination of the sample constituents using a GC-MS system; (2) quantitation of the amount of the starting materials, phenyl acetic acid and acetic acid, by a potentiometric titration; (3) quantitation by gas chromatography (flame ionization detector) using an internal standard; and (4) high-performance liquid chromatography using both normal and reverse phase chromatographic separations.