cssi/SciSciGPT-SciSciNet huggingface dataset:
How old are dense-core vesicles residing in en passant boutons: simulation of the mean age of dense-core vesicles in axonal arbours accounting for resident and transiting vesicle populations

In neurons, neuropeptides are synthesized in the soma and are then transported along the axon in dense-core vesicles (DCVs). DCVs are captured in varicosities located along the axon terminal called en passant boutons, which are active terminal sites that accumulate and release neurotransmitters. Recently developed experimental techniques allow for the estimation of the age of DCVs in various locations in the axon terminal. Accurate simulation of the mean age of DCVs in boutons requires the development of a model that would account for resident, transiting-anterograde and transiting-retrograde DCV populations. In this paper, such a model is developed. The model is applied to simulating DCV transport in Drosophila type II motoneurons. The model simulates DCV transport and capture in the axon terminals and makes it possible to predict the age density distribution of DCVs in en passant boutons as well as DCV mean age in boutons. The predicted prevalence of older organelles in distal boutons may explain the 'dying back' pattern of axonal degeneration observed in dopaminergic neurons in Parkinson's disease. The predicted difference of two hours between the age of older DCVs residing in distal boutons and the age of younger DCVs residing in proximal boutons is consistent with an approximate estimate of age difference deduced from experimental observations. The age density of resident DCVs is found to be bimodal, which is because DCVs are captured from two transiting states: the anterograde transiting state that contains younger DCVs and the retrograde transiting state that contains older DCVs.
Hexagonal mosaic links generated by saturation

Square mosaic knots have many applications in algebra, such as modeling quantum states. In this paper, we extend mosaic knot theory to a theory of hexagonal mosaic links, which are links embedded i...
The Degradation of Chlorophyll Pigments in Dairy Silage: The Timeline of Anaerobic Fermentation

Background Detection of chlorophyll metabolites in milk has recently been suggested to be an indicator of a grass-fed diet fed for cattle. Such a means of detection, however, is complicated when the grazing season is over because cattle can be fed fermented silage ingredients, such as alfalfa and corn silage. During fermentation, chlorophyll compounds and other pigments undergo degradation due to the accumulation of lactic acid and the resultant decline in pH. Results We monitored degradation of chlorophyll compounds by measuring the fluorescence and absorption spectra of silage extracts. The spectroscopic evidence supports the hypothesis that chlorophylls are converted into fluorescent products, such as pheophytin, and further cleaved into pheophorbide. The degradation starts with dechelation and removal of the magnesium ion to produce pheophytin. Further removal of the phytol chain from pheophytin results in the production of pheophorbide. Conclusions The fluorescence intensity of these degradation products is reduced compared to that of the parent molecule. These findings are important in understanding the fluorescent signal in milk when cows consume silage rather than fresh pasture grass. © 2020 Society of Chemical Industry.
Tomosynthesis-Guided Vacuum-Assisted Breast Biopsy of Architectural Distortion Without a Sonographic Correlate: A Retrospective Review.

Please see the Editorial Comment by Melissa A. Durand discussing this article. BACKGROUND. Digital breast tomosynthesis-guided vacuum-assisted breast biopsy (DBT VAB) allows biopsy of findings seen...
Multi-Physics Model of Lithium-Ion Battery and Battery Pack Undergoing Abuse Conditions

Lithium-ion batteries (LIB) have found a wide range of applications in the last 25 years including consumer products, electric vehicles, grid storage, and the military. The United States Navy and Marine Corps have various applications requiring LIB, and safety is one of the primary considerations for shipboard carriage or integration. One of the most important safety considerations for LIB is their behavior under various abuses such as incipient failure due to manufacturing imperfections, exposure to heat, external short circuit, and mechanical abuse. Several exothermic reactions can occur as the inner cell temperature increases, and if the heat generation is larger than the dissipated heat to the surroundings, this leads to heat accumulation in the cell and acceleration of the chemical reactions, which can then lead to a thermal runaway. Therefore, much effort has been focused on understanding the progression of thermal runaway in LIB under abuse conditions, and how to model and predict behavior. Based upon previous work that has successfully developed multi-scale models (i.e., electrochemical and thermal-mechanical models) for modeling the thermal runaway inside large-format LIB, this study focuses on how to model the temperature distributions within packs of cells based on various battery-pack design constraints. In the current study, a multi-physics model of LIB is developed using COMSOL Multiphysics simulation software and the model is also validated using experimental cell data collected at Naval Surface Warfare Center Carderock Division (NSWCCD). The temperature distribution within a simplified LIB cell pack is also developed to assess various battery-pack design constraints and
Social Problems: A Human Rights Perspective

1. Introduction to the Human Rights Approach 2. Rights to Wellbeing and Property in an Unequal Society 3. American Inequality and the Rights to Speech and Democracy 4. Racism and the Human Right to be Treated Equally Before the Law 5. Sexism and the Right to Bodily Integrity 6. U.S. Society, Global Inequalities, and Human Rights 7. Conclusion: Volunteerism, Activism, and the Pursuit of Human Rights
Biochemical control of erythroid cell development.

Publisher Summary This chapter discusses the biochemistry of the control of erythrocyte formation. Although the information on the biochemical properties of the red cell is immense, considerably less is known about the molecular mechanisms for the formation of erythrocytes from the precursors. The task of the biochemist, studying the process of differentiation, is to determine the detailed molecular mechanisms that account for the appearance and disappearance of specific groups of synthetic capabilities and properties in the differentiated cells. In general, the material of choice for this type of investigation is the developing embryo or the cellular systems derived from it. Evidence is presented, indicating that the hormone erythropoietin is the direct regulator of red blood cell formation in mammals and is also the primary inducing factor for erythroid differentiation. Erythropoietin can be obtained from the plasma or urine of anemic animals and, although not yet purified, appears to be a glycoprotein of fairly large molecular size. Erythroid differentiation is arbitrarily divided into distinct phases and some speculative models are proposed for the molecular and cytological mechanisms underlying the processes.
An inexpensive robot arm for computer vision applications

The authors have developed a simple, economical robotic arm with both image acquisition and range sensing capabilities for machine vision applications. It is connected via an interface board to an IBM PC/AT microcomputer, offering maximum flexibility in programming the arm for different tasks. A sonar ranging device and a video camera are mounted on the arm, and give the system 3-D vision capabilities. The sonar ranging device and associated clock/counter circuitry is connected to the computer via the same board as the robotic arm, whereas the video camera is connected to an image digitization and display board. To illustrate its capabilities, the arm was programmed to scan the immediate environment and attempt to locate and identify the nearest object. Standard image processing and computer vision techniques such as binary thresholding, histogram analysis, signatures and pattern recognition were applied, and excellent object recognition was achieved under a wide variety of lighting and distance conditions. >
For a better support of static data flow

This paper identifies and solves a class of problems that arise in binding time analysis and more generally in partial evaluation of programs: the approximation and loss of static information due to dynamic expressions with static subexpressions. Solving this class of problems yields substantial binding time improvements and thus dramatically better results not only in the case of partial evaluation but also for static analyses of programs—this last point actually is related to a theoretical result obtained by Nielson. Our work can also be interpreted as providing a solution to the problem of conditionally static data, the dual of partially static data.
Beyond PowerPoint™: Using Learning Objects to Enhance Social Work Courses

Faculty use of information and communication technologies (ICT) in social work courses has the potential to transform social work education, including increasing student engagement and accommodating different learning styles. Learning objects are reusable digital resources with a pedagogical purpose that may be used in online, hybrid, or face-to-face social work courses to achieve these and other pedagogical benefits. This article defines and provides an overview of the concept “learning objects.” Guidelines for locating and incorporating existing learning objects and for creating learning objects for use in social work courses are detailed. Finally, examples are provided.
X-Train: Teaching Professionals Remotely

Increased popularity of the Internet, along with the development of new software applications have dramatically improved our ability to create and deliver online continuing education trainings to professionals in the areas of nutrition and food safety. In addition, these technological advances permit effective and affordable measurement of training outcomes, i.e., changes in knowledge, attitude, and behavior, that result from these educational efforts. Impact assessment of engagement programs is becoming increasing important for demonstrating the value of training activities to stakeholders. A novel software program, called X-Train, takes advantage of technological advances (databases, computer graphics, Web-based interfaces, and network speed) for delivering high-quality trainings to teachers and health care professionals. X-Train automatically collects outcome data, and generates and sends certificates of completion and communicates with participants through electronic messages. X-Train can be used as a collaborative tool whereby experts from various academic institutions are brought together to develop Web-based trainings. Finally, X-Train uses a unique approach that encourages cooperative extension specialists and educators to promote these educational opportunities within their state or county.
Creating a Functional Opioid Alkaloid Binding Site in the Orphanin FQ Receptor through Site-Directed Mutagenesis

Although much has been learned about the mechanisms of ligand selectivity between different opioid receptor subtypes, little is known about the common opioid binding pocket shared by all opioid receptors. The recently discovered orphanin system offers a good opportunity to study the mechanisms involved in the binding of opioid versus nonopioid ligands. In the current study, we adopt a “gain of function” approach aimed at shifting the binding profile of the orphanin FQ receptor toward that of the opioid receptors. After two rounds of mutagenesis, several orphanin FQ receptor mutants can be labeled with the opiate alkaloid [3H]naltrindole and show greatly increased affinities toward the opiate antagonists naltrexone, nor-binaltrophine HCl, and (−)-bremazocine. These orphanin FQ receptor mutants also display stereospecificity similar to that of opioid receptors. Furthermore, the orphanin FQ receptor mutant that has the best affinities toward the opioid alkaloids shows, in the presence of GTP and high salt concentration, an affinity-shift profile similar to that of the δ receptor. Most strikingly, the same mutant exhibits naltrindole-sensitive etorphine-stimulated [35S]guanosine-5′-O-(3-thio)triphosphate binding, whereas the effect of etorphine on GTP binding cannot be inhibited by naltrindole in the wild-type receptor. Our results indicate that 1) several residues in the orphanin FQ receptor are critical to its selectivity against the opiate alkaloids, particularly antagonists; and 2) mutating these residues to those of the opioid receptor at the corresponding position preserves the agonist/antagonist nature of opiate alkaloids as they interact with the mutant receptor. It is reasonable to hypothesize that the corresponding residues in the opioid receptors may form a functional common binding pocket for opiate alkaloids. These findings may be helpful to medicinal chemists in designing ligands for the orphanin FQ receptor based on the structure of the opiate alkaloids.
Origin of Radiation-Induced Degradation in Polymer Solar Cells

Polymer solar cells have been shown to degrade under X-rays. Here, in situ polymer photovoltaic performance and recombination lifetimes are measured and it is found that charge accumulation is the primary reason for degradation of solar cells. This is affected by the mixing ratio of donor and acceptor in the bulk heterojunction. Both a quantitative understanding and the physical model of the degradation mechanism are presented. Understanding of the degradation mechanism is extended in polymer donor-acceptor bulk heterojunction systems to propose a material combination for making radiation hard diodes that can find important application in fields ranging from memory arrays to organic X-ray detectors for medical imaging.
Parallel and distributed incremental attribute evaluation algorithms for multiuser software development environments

The problem of change propagation in multiuser software development environments distributed across a local-area network is addressed. The program is modeled as an attributed parse tree segmented among multiple user processes and changes are modeled as subtree replacements requested asynchronously by individual users. Change propagation is then implemented using decentralized incremental evaluation of an attribute grammar that defines the static semantic properties of the programming language. Building up to our primary result, we first present algorithms that support parallel evaluation on a centralized tree in response to single edits using a singe editing cursor and multiple edits with multiple editing cursors. Then we present our algorithm for parallel evaluation on a decentralized tree. We also present a protocol to guarantee reliability of the evaluation algorithm as components of the decentralized tree become unavailable due to failures and return to availability.
POLLEN EVIDENCE FOR CLIMATIC VARIABILITY AND CULTURAL DISTURBANCE IN THE MAYA LOWLANDS

Palynology provides a record of past environmental change in the Maya Lowlands. The underlying principles are simple, but, as with all proxies, there are limitations. During the late glacial period, environmental change was governed by climate, which was cooler and much drier and supported sparse temperate vegetation. The early Holocene epoch was warmer and very wet in the southern Lowlands when mesic tropical forests predominated, while the northern Yucatan Peninsula was edaphically dry until eustatic sea level rose. The modern distributions of plant associations and climatic gradients were established at the end of the early Holocene. Climatic variability continued throughout the Holocene. However, the ability of palynology to identify climatic events is hindered after the Maya became numerous in the Lowlands. Then, multidisciplinary studies provide a better interpretation of events, especially during the late Holocene. Pollen records poorly reflect cyclical droughts seen in isotopic records, as natural vegetation has adapted to these fluctuations.
The phospholipase complex PAFAH Ib regulates the functional organization of the Golgi complex

We report that platelet-activating factor acetylhydrolase (PAFAH) Ib, comprised of two phospholipase A2 (PLA2) subunits, α1 and α2, and a third subunit, the dynein regulator lissencephaly 1 (LIS1), mediates the structure and function of the Golgi complex. Both α1 and α2 partially localize on Golgi membranes, and purified catalytically active, but not inactive α1 and α2 induce Golgi membrane tubule formation in a reconstitution system. Overexpression of wild-type or mutant α1 or α2 revealed that both PLA2 activity and LIS1 are important for maintaining Golgi structure. Knockdown of PAFAH Ib subunits fragments the Golgi complex, inhibits tubule-mediated reassembly of intact Golgi ribbons, and slows secretion of cargo. Our results demonstrate a cooperative interplay between the PLA2 activity of α1 and α2 with LIS1 to facilitate the functional organization of the Golgi complex, thereby suggesting a model that links phospholipid remodeling and membrane tubulation to dynein-dependent transport.
Stress in the workplace: a comparison of gender and occupations

Stressful incidents at work were examined using an open-ended technique for three different occupations: clerical workers, university professors and sales associates. The study revealed both similarities and differences in stressors and coping techniques reported across occupations. Interpersonal conflict, work overload and time wasters were common across all occupations. Lack of control and work overload were reported as major stressors by the clerical group and interpersonal conflict as a major stressor by the academic and sales groups. Gender differences were also found. Copyright © 1999 John Wiley & Sons, Ltd.
Relationship between a Wiener-Hermite expansion and an energy cascade

Meecham and his co-workers have developed a theory of turbulence involving a truncated Wiener–Hermite expansion of the velocity field. The randomness is taken up by a white-noise function associated, in the original version of the theory, with the initial state of the flow. The mechanical problem then reduces to a set of coupled integro-differential equations for deterministic kernels. We have solved numerically an analogous set for Burgers's model equation and have computed, for the sake of comparison, actual random solutions of the Burgers equation. We find that the theory based on the first two terms of the Wiener–Hermite expansion predicts an insufficient rate of energy decay for Reynolds numbers larger than two, because the equations for the kernels contain no convolution integrals in wave-number space and therefore permit no cascade of energy. An energy cascade in wave-number space corresponds to a cascade up through successive terms of the Wiener-Hermite expansion. Pictures of the Gaussian and non-Gaussian components of an actual solution of the Burgers equation show directly that only higher-order terms in the Wiener–Hermite expansion are capable of representing shocks, which dissipate the energy. Higher-order terms would be needed even for a nearly Gaussian field of evolving three-dimensional turbulence. ‘Gaussianity’, in the experimentalist's sense, has no bearing on the rate of convergence of a Wiener–Hermite expansion whose white-noise function is associated with the initial state. Such an expansion would converge only if the velocity field and its initial state were joint-normally distributed. The question whether a time-varying white-noise function can speed the convergence is treated in the paper following this one.
Transcriptional regulation by hypoxia-inducible factor 1 molecular mechanisms of oxygen homeostasis.

Human cells require O(2) for many metabolic processes, most notably oxidative phosphorylation, the major source of ATP generation, and hypoxia plays a significant pathophysiologic role in a variety of cardiovascular disorders. Hypoxia-inducible factor 1 (HIF-1) is a transcriptional activator of genes whose products, including erythropoietin, vascular endothelial growth factor, and glycolytic enzymes, are involved in systemic, local, and cellular responses to hypoxia that either increase O(2) delivery or induce alternative metabolic pathways that do not require O(2). The level of HIF-1 expression in cultured cells is proportional to the degree of hypoxia over the range of O(2) concentrations associated with physiologic and pathophysiologic conditions in vivo. Further investigation of HIF-1 function in vivo may lead to novel therapeutic approaches that modulate cellular responses to hypoxia/ischemia. (Trends Cardiovasc Med 1996;6:151-157).
Forecasting in least absolute value regression with autocorrelated errors: a small-sample study

Abstract Least absolute value (LAV) regression is a robust alternative to ordinary least squares (OLS) and is particularly useful when model disturbances follow distributions that are nonnormal and subject to outliers. The performance of the OLS estimator when the disturbances are autocorrelated has been studied extensively, but the performance of the LAV estimator in the presence of serial correlation is less well established. In this research, we study the forecasting performances of OLS- and LAV-based models for simple time series regression when the errors are autocorrelated. Monte Carlo simulation methods are used to compare the forecasting accuracies of the different models. A least absolute value analogue of the Prais-Winsten correction possesses an appealing robustness for the context under consideration.
Microstructure coarsening during static annealing of 60Sn40Pb solder: III Intermetallic compound growth kinetics

The growth of the total (Cu3Sn+Cu6Sn) intermetallic compound layer in Cu-60Sn40Pb solder joints during static annealing at 50°C to 150°C was described by the equation hi=ho+Ao exp(−Qa/RT)tp with ho=0–0.3 μm, p=0.38–0.70, Ao=1.9×10−4–3.4×10−4 m/sp, and Qa=25.5–30.9 kJ/mole. These constants are within the range of those obtained by others and give values of Do and Q which are in reasonable accord with those for the diffusion coefficients in Cu3Sn and Cu6Sn5 determined in diffusion couples. The deviation of the values of the time exponent p from the ideal of 0.5 for diffusion growth may be due to inaccuracies or errors pertaining to the measured thickness (especially ho) and the complex nature of the diffusion process.
MLN0128, an ATP-Competitive mTOR Kinase Inhibitor with Potent In Vitro and In Vivo Antitumor Activity, as Potential Therapy for Bone and Soft-Tissue Sarcoma

The mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase that exists in two complexes (mTORC1 and mTORC2) and integrates extracellular and intracellular signals to act as a master regulator of cell growth, survival, and metabolism. The PI3K/AKT/mTOR pro-survival pathway is often dysregulated in multiple sarcoma subtypes. First-generation allosteric inhibitors of mTORC1 (rapalogues) have been extensively tested with great pre-clinical promise, but have had limited clinical utility. Here we report that MLN0128, a second-generation, ATP-competitive, pan-mTOR kinase inhibitor, acts on both mTORC1 and mTORC2, and has potent in vitro and in vivo anti-tumor activity in multiple sarcoma subtypes. In vitro, MLN0128 inhibits mTORC1/2 targets in a concentration dependent fashion, and shows striking anti-proliferative effect in rhabdomyosarcoma (RMS), Ewing sarcoma (ES), malignant peripheral nerve sheath tumor, synovial sarcoma, osteosarcoma, and liposarcoma. Unlike rapamycin, MLN0128 inhibits phosphorylation of 4EBP1 and NDRG1 as well as prevents the reactivation of pAKT that occurs via negative feedback release with mTORC1 inhibition alone. In xenograft models, MLN0128 treatment results in suppression of tumor growth with two dosing schedules (1 mg/kg daily and 3 mg/kg BID TIW). At the 3 mg/kg dosing schedule, MLN0128 treatment results in significantly better tumor growth suppression than rapamycin in RMS and ES models. Additionally, MLN0128 induces apoptosis in models of RMS both in vitro and in vivo. Results from our study strongly suggest that MLN0128 treatment should be explored further as potential therapy for sarcoma.
The effects of footshock stress on regional brain dopamine metabolism and pituitary β-endorphin release in rats previously sensitized to amphetamine

The repeated intermittent administration of amphetamine (AMP) produces an enduring enhancement in the response of dopamine (DA) systems in the brain to a subsequent “challenge” with amphetamine. However, former amphetamine addicts are not only hypersensitive to amphetamine, but also to “physical or psychologtical stress”. This suggests that sensitization to amphetamine may change the response of DA neurons in brain to subsequent stress. To explore this idea, the effects of footshock stress on regional metabolism of DA in brain, and on the concentrations of plasma β-endorphin and N-acetylated β-endorphin, were studied in rats previously exposed to amphetamine or saline. It was found that: (I) Prior treatment with amphetamine produced enduring (at least 7 days) changes in the dopaminergic response to footshock in the medial frontal cortex, hypothalamus, dorsolateral striatum and nucleus accumbens. Generally, rats pretreated with amphetamine showed a greater initial reduction in concentrations of DA in response to footshock, and a greater elevation in concentrations of metabolites of DA and/or metabolite/transmitter ratios, compared to nonhandled control rats. (2) In some regions of the brain repeated injections of saline produced changes in the response to subsequent footshock that were comparable to those produced by amphetamine. (3) Prior treatment with amphetamine enhanced theelease of β-endorphin and N-acetylated β-endorphin from the pituitary elicited by footshock stress. It is concluded that repeated intermittent treatment with amphetamine or stress (injections of saline) produce enduring changes in the response of DA neurons and the pituitary to subsequent stress. These changes may be responsible for the hypersensitivity to stress reported in former amphetamine addicts, and in rats previously sensitized to amphetamine.
Path-integral simulation of positronium in a hard sphere

We employ the path-integral Monte Carlo method to study the binding energyof positronium trapped within a hard sphere. The two-body density matrix andthe total- and kinetic-energy matrices are obtained by matrix squaring. Thepair-product approximation is then used to obtain the entire density andestimator matrices for the Monte Carlo simulation. Ground-state bindingenergies are obtained as a function of sphere radius and the system is found tobecome unbound near a radius of 4 bohrs. Annihilation times are calculatedwhich vary from 125 ps for free-space positronium down to 76 ps at a sphereradius of 4 bohrs.
Outcome of Severe Refractory Status Epilepticus in Children

Summary: Purpose: Refractory status epilepticus (RSE) is the persistence of seizure activity despite appropriate therapy; it is treated with high-dose suppressive anesthetic agents. We report here the outcome of RSE in a large series of children. Methods: We retrospectively reviewed cases of RSE treated at Children's Hospital, Boston, between 1992 and 2000. Factors evaluated included age, history of seizures or neurologic impairment, etiology, outcome, including mortality or return to baseline, and initial EEG findings. Results: Twenty-two patients ages 4.5 months to 18 years were admitted to the intensive care unit for RSE. All were treated with high-dose suppressive therapy consisting of pentobarbital, midazolam, propofol infusion, or high-dose phenobarbital, either alone, or in combination, for ≤146 days. The overall mortality was seven of 22. Mortality was related to etiology, age, and EEG findings. No death occurred in the remote symptomatic group, and three of four younger than 3 years died, whereas only four of 18 older than 3 years died. The mortality rate among patients with focal abnormalities on the EEG was lower than that among those with multifocal or generalized abnormalities. None of the children with normal premorbid neurologic status returned to baseline. Conclusions: Our data demonstrate a high mortality and morbidity for childhood RSE. Mortality is related to etiology and is higher in younger children and with multifocal or generalized abnormalities on the initial EEG.
Muscle sympathetic nerve activity during postural change in healthy young and older adults

Recent evidence suggests that during orthostatic stress the reflex increase in muscle sympathetic nerve activity may be diminished in older adults. To test this hypothesis, we measured muscle sympathetic nerve activity, plasma noradrenaline concentrations, heart rate, and arterial blood pressure in twelve young (mean, 25 years; range, 19–29 years) adults and 14 older (mean 64 years; range, 60–74 years) healthy adults, while supine and during upright sitting. Supine control levels of muscle sympathetic nerve activity were higher in the older subjects (35 ± 1 vs. 25 ± 1 bursts/min,p < 0.05), but there were no differences in plasma noradrenaline concentrations, heart rate or arterial pressure. Despite higher supine control levels in the older group, the absolute unit increases in muscle sympathetic nerve activity in response to upright sitting (p < 0.05 vs. control) were not different in the two groups (7 ± 1 vs. 7 ± 1 bursts/min), nor were the increases in plasma noradrenaline concentrations. Heart rate did not increase above supine control in response to sitting in either group. Arterial pressure increased slightly (p < 0.05, supine vs. control), but there were no age-related differences. These results indicate that, contrary to recent findings, the reflex increases in muscle sympathetic nerve activity and plasma noradrenaline concentrations and regulation of arterial pressure during this natural orthostatic stress are well preserved in older healthy men and women.
Ferromagnetic fractional quantum Hall states in a valley-degenerate two-dimensional electron system.

We study a two-dimensional electron system where the electrons occupy two conduction band valleys with anisotropic Fermi contours and strain-tunable occupation. We observe persistent quantum Hall states at filling factors $\ensuremath{\nu}=1/3$ and $5/3$ even at zero strain when the two valleys are degenerate. This is reminiscent of the quantum Hall ferromagnet formed at $\ensuremath{\nu}=1$ in the same system at zero strain. In the absence of a theory for a system with anisotropic valleys, we compare the energy gaps measured at $\ensuremath{\nu}=1/3$ and $5/3$ to the available theory developed for single-valley, two-spin systems, and find that the gaps and their rates of rise with strain are much smaller than predicted.
A new set of molecular mechanics parameters for hydroxyproline and its use in molecular dynamics simulations of collagen‐like peptides

Recently, the importance of proline ring pucker conformations in collagen has been suggested in the context of hydroxylation of prolines. The previous molecular mechanics parameters for hydroxyproline, however, do not reproduce the correct pucker preference. We have developed a new set of parameters that reproduces the correct pucker preference. Our molecular dynamics simulations of proline and hydroxyproline monomers as well as collagen-like peptides, using the new parameters, support the theory that the role of hydroxylation in collagen is to stabilize the triple helix by adjusting to the right pucker conformation (and thus the right ϕ angle) in the Y position. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1612–1616, 2005
Directed percolation and Reggeon field theory

Directed bond percolation is shown to be in the same universality class as Reggeon field theory. The critical behaviour and critical exponents near the percolation threshold are thereby inferred.
Sand Fences in the Coastal Zone: Intended and Unintended Effects

Sand-trapping fences modify the character of the coastal landscape and change its spatial structure, image, and meaning. This paper examines the relationship between these changes and fence usage at the municipal level, where most decisions about fence deployment are made. Use of fences in 29 municipalities on the developed coast of New Jersey is examined over a 6-year period. Interviews with municipal officers indicate that wooden slat sand-trapping fences are used primarily to build dunes to provide protection against wave uprush and flooding, but they are also used to control pedestrian traffic and demarcate territory. These uses result in changes in landforms and habitats. An aerial video inventory of fences taken in 2002 indicates that 82% of the shoreline had fences and 72% had dunes. Single and double straight fence rows are the most commonly used. Fences are often built to accomplish a specific primary purpose, but they can cause many different and often unanticipated changes to the landscape. The effects of a sand fence change through time as the initial structure traps sand, creates a dune that is colonized by vegetation, and becomes integrated into the environment by increasing topographic variability and aesthetic and habitat value. Sand fences can be made more compatible with natural processes by not placing them in locations where sources of wind blown sand are restricted or in unnatural shore perpendicular orientations. Symbolic fences are less expensive, are easy to replace when damaged, are less visually intrusive, and can be used for controlling pedestrian access.
Magnetic Properties and Micromagnetic Character of RF Sputtered Co Thin Films on Thin Cr Underlayers

The effect of thin Cr underlayers on the coercivity, the initial susceptibility, and micromagnetic structure of RF sputtered Co/Cr thin films have been studied. A reciprocal relationship between the initial susceptibility and the coercivity of the RF sputtered Co/Cr films were observed. Micromagnetic images of these Co/Cr films obtained by Fresnel mode Lorentz TEM revealed a refinement of the micromagnetic images correlated with a simultaneous increase in coercivity and decrease in initial susceptibility. Such behavior is expected in cases where the initial magnetization and magnetization reversal are hindered by the variation of local energy with the magnetic moment distribution. The interaction of the Cr underlayers with the Co magnetic overlayer very likely induces fluctuations in local magnetic energy of the Co films. Accordingly, the initial magnetization and magnetization reversal are likely to be impeded by fluctuations of the magnetic energy resulting in the observed increase in coercivity and decrease in initial susceptibility.
CLINICAL AND MOLECULAR ANALYSIS OF XX SEX REVERSED PATIENTS

AbstractPurpose: The XX male syndrome presents with a spectrum of clinical appearances from phenotypic male individuals to true hermaphrodites. Previous reports established the sex determining region of the Y chromosome (SRY) gene as the testis determining factor. However, a subset of XX sex reversed male individuals exists without a translocation of SRY deoxyribonucleic acid (DNA) material to the X chromosome. In addition to clinical or endocrinological criteria, Y DNA probe studies, and radiological and surgical evaluation as indicated are necessary for an accurate diagnosis.Materials and Methods: We evaluated 5 XX sex reversed patients (2 true hermaphrodites and 3 male individuals) by physical examination, pedigree analysis, endocrinological testing, molecular analysis of Y DNA, radiological studies and surgery (exploration and/or biopsy).Results: All patients were SRY gene negative. Two patients were siblings. Complete endocrinological testing was negative in all cases. Two patients had a normal male ...
Magnesium diboride: Superior thin films.

Conventional superconductors, such as niobium, may soon have competition from a recent upstart. A new technique for growing thin films of MgB2 removes one serious hurdle in the path to commercialization.
Dynamics and Stability of Individual Base Pairs in Two Homologous RNA―DNA Hybrids

Nuclear magnetic resonance spectroscopy and proton exchange have been used to characterize two RNA-DNA hybrids from the tR2 intrinsic transcription terminator site of phage lambda. The hybrids have the same base sequence [5'-GGCGCAGGCC(T/U)(T/U)CC-3'/5'-GGAAGGCC(T/U)GCGCC-3'] but differ from each other by an interchange of DNA and RNA strands. The opening of single base pairs in the two hybrids is characterized by measuring the rates of exchange of imino protons with solvent protons as a function of the concentration of a proton acceptor (ammonia base) at 10 degrees C. The free energy change in the opening reaction provides a measure of the stability of the base pair, while the rates of opening and closing define the base pair dynamics. The results demonstrate that, within the same base sequence context, dA-rU base pairs are less stable than dT-rA base pairs. The differences in stability are enhanced when two dA-rU base pairs are located next to each other in the hybrid structure. For the G-C base pairs, the rates of opening and closing and the stability are affected by the base sequence context and by the nature of the sugar moiety attached to the guanine. The dominant feature of the base sequence is the proximity of the dA-rU base pair, which destabilizes the G-C base pair when the guanine is located on the DNA strand. Two G-C base pairs (namely, those in the fourth and 10th positions) exhibit large differences in their opening and closing rates between the two hybrids, while maintaining the same stability. These results provide the first demonstration that, for RNA-DNA hybrid structures with the same base sequence, the opening dynamics and the stability of individual base pairs are strongly influenced by the chemical nature of each strand.
INDETERMINATE GROWTH OF PERICARPS IN THREE MEMBERS OF THE RHODYMENIALES (RHODOPHYTA)12

Pericarps generally are thought of as structures having determinate growth, serving as a protective covering for the developing gonimoblast. In laboratory culture, the pericarps of Champia parvula (C. Agardh) Harvey, Lomentaria baileyana (Harvey) Farlow and Lomentaria sp. exhibited indeterminate growth. These tissues could be excised and grown as separate female plants. The new plants were indistinguishable from the parent tissue, were fertile, and produced viable carpospores.
Neuroprotective Effects of Vascular Endothelial Growth Factor Following Hypoxic Ischemic Brain Injury in Neonatal Rats

Vascular Endothelial Growth Factor (VEGF) protects the brain against ischemic injury in adult animals. We evaluated whether VEGF has neuroprotective effects against hypoxic-ischemic (HI) brain injury in newborn rats. Seven-day-old rat pups had the right carotid artery permanently ligated followed by 140 min of hypoxia (8% oxygen). VEGF (5, 10, 20, or 40 ng) or vehicle was administered intracerebroventricularly 5 min after reoxygenation following HI. Brain damage was evaluated by weight loss of the right hemisphere at 22 d after HI and by gross and microscopic morphology. Body weight, rectal temperature, and mortality were not significantly different in the VEGF and vehicle treated groups. VEGF treatment increased brain VEGF levels at 15 min after injection. VEGF (10 and 20 ng) significantly reduced brain weight loss (p < 0.05) and gross brain injury (p < 0.05); however, treatment with 5 or 40 ng did not. VEGF (10 ng) also decreased brain damage assessed by histologic scoring. VEGF increased phosphorylation of protein kinase B (Akt) and extracellular-signal regulated kinase 1/2 (ERK1/2) in the cortex (p < 0.05). These results suggest that VEGF has neuroprotective effects in the neonatal rat HI model that may be related to activation of the Akt/ERK signaling pathway.
Mechanism of the action of abrasives on infection by tobacco mosaic virus

Abstract With 10% 600-mesh Carborundum powder in the inoculum, the conditions giving the greatest amount of infection by tobacco mosaic virus on Scotia bean leaves were 0.1 M phosphate buffer when the H-ion concentration was held constant at pH 8.5, a H-ion concentration of pH 8.5 with buffer constant at 0.1 M concentration, and pH 7.0 without buffer. With 600-mesh Carborundum powder in the inoculum at pH 8.5 and 0.1 M buffer, the greatest amount of infection occurred at 7% abrasive. With 10% abrasive in the inoculum, there was an increase in the amount of infection with a decrease in the particle size of the abrasive in the range of 150 to 800 mesh. The increase in the amount of infection due to abrasives of 240 and 800 mesh was related to the number of abrasive particles in the inoculum and not to the amount or size of the abrasive particles except as these factors relate to the number. The dilution end point of virus extract was 1 × 10−5 in nonbuffered dilutions without abrasive, 1 × 10−6 in nonbuffered dilutions with abrasive and also in 0.1 M buffer at pH 8.5 without abrasive, and 1 × 10−7 in 0.1 M buffer at pH 8.5 with abrasive. The absence of virus adsorption by particles of Carborundum powder at 8.5, the optimal pH for infection, indicates that the abrasive particles do not carry the virus into the tissues but provide wounds suitable for infection.
Dissociation and ionization of molecular ions by ultra-short intense laser pulses probed by coincidence 3D momentum imaging

Abstract We have experimentally explored laser-induced dissociation and ionization of diatomic molecular ions using coincidence 3D momentum imaging. The vibrationally excited molecular ion beam (4–8 keV) is crossed by an ultrafast intense laser beam (28–200 fs, 1013–1014 W/cm2). The resulting fragments are recorded in coincidence by a time and position-sensitive detector. Complete angular distributions and kinetic energy release maps are reconstructed from the measured dissociation-momentum vectors. The angular distribution of the H+ + H fragments was found to be strongly correlated to their kinetic energy release upon dissociation. Low KER was associated with very narrow angular distributions and high KER with distributions peaking away from the laser polarization. Ionization was found to be smaller than dissociation and increased with laser intensity. The H+ + H+ fragments have a very narrow angular distribution along the laser polarization.
Estimation of sensitivity coefficients of nonlinear model input parameters which have a multinormal distribution

This paper considers the estimation of sensitivity coefficients based on sequential random sampling when the input parameters of a nonlinear model are correlated and have a multinormal distribution. Due to the difficulties in generating sequential random samples for correlated model inputs and the properties of response surface models, sampling-based (simulation- and experiment-based) methods could not be used to estimate sensitivity coefficients of correlated model inputs. For this reason, an algorithm based on multi-expressions of multinormal distribution has been developed and used to generate sequential random samples for estimation of sensitivity coefficients. The multi-expression approach has very high accuracy in generating multinormal random samples. The estimated sensitivity coefficients based on sequential random samples changed when sample size changed. Most estimates converged with a sample size of 5000. Model structure mainly determined the speed of convergence. Both correlation among input parameters and model structure influenced the estimates of sensitivity coefficients. The sensitivity coefficients were compared to global partial derivatives that were computed using numerical integration.
Structure of random monodisperse foam

The Surface Evolver was used to calculate the equilibrium microstructure of random monodisperse soap froth, starting from Voronoi partitions of randomly packed spheres. The sphere packing has a strong influence on foam properties, such as E ~surface free energy! and ^ f & ~average number of faces per cell!. This means that random foams composed of equal-volume cells come in a range of structures with different topological and geometric properties. Annealing—subjecting relaxed foams to large-deformation, tension-compression cycles—provokes topological transitions that can further reduce E and ^ f &. All of the foams have ^ f &<14. The topological statistics and census of cell types for fully annealed foams are in excellent agreement with experiments by Matzke. Geometric properties related to surface area, edge length, and stress are evaluated for the foams and their individual cells. Simple models based on regular polygons predict trends for the edge length of individual cells and the area of individual faces. Graphs of surface area vs shape anisotropy for the cells reflect the geometrical frustration in random monodisperse foam, which is epitomized by pentagonal dodecahedra: they have low surface area but do not pack to fill space.
Percutaneous Management of Chronic Critical Limb Ischemia

Critical limb ischemia (CLI) is primarily a disease of advanced atherosclerosis but may occur in the setting of other causes. It is essential for the treating physician to understand the complexity of patients with CLI and the appropriate and emerging treatment approaches in this patient population. The authors provide a comprehensive review of the percutaneous endovascular management of CLI in this article.
Public Figure Announcements About Cancer and Opportunities for Cancer Communication: A Review and Research Agenda

Announcements by public figures and celebrities about cancer diagnosis or death represent significant events in public life. But what are the substantive effects of such events, if any? The purpose of this article is to systematically review studies that examined the impact of public figure cancer announcements on cancer-oriented outcomes. Using comprehensive search procedures, we identified k = 19 studies that examined 11 distinct public figures. The most commonly studied public figures were Jade Goody, Kylie Minogue, Nancy Reagan, and Steve Jobs, with the most common cancers studied being breast (53%), cervical (21%), and pancreatic (21%) cancer. Most studies assessed multiple outcome variables, including behavioral outcomes (k = 15), media coverage (k = 10), information seeking (k = 8), cancer incidence (k = 3), and interpersonal communication (k = 2). Results fairly consistently indicated that cancer announcements from public figures had meaningful effects on many, if not most, of these outcome variables. While such events essentially act as naturally occurring interventions, the effects tend to be relatively short term. Gaps in this literature include few contemporary studies of high-profile public figures in the United States and a general lack of theory-based research. Directions for future research as well as implications for cancer communication and prevention are discussed.