cssi/SciSciGPT-SciSciNet huggingface dataset:
An improved regularized fundamental solution to the 2-D steady-state Stokes equation

Abstract A new regularized fundamental solution to the Stokes equation in 2-D notation was derived using the new cut-off (blob) function. It substitutes the delta-Dirac function, which represents source term in a classical form of the equation expressed with the Green's functions. The proposed cut-off function/blob selection led to a much simpler and, therefore, faster fundamental solution in terms of elapsed computational time. Thus, it was possible to find boundary values and solve the linear system of the Stokes equations in 114 s applying backslash solver in Matlab 2013 on a quad-core 2.8 GHz each and 8RAM processor machine. This computation time appeared to become approximately 2.5 times less than the time required to run the same code with the known regularized fundamental solution to the 2-D steady-state Stokes equations. Validation of the proposed solution was performed using well-known problems of the Stokes flow in a lid-driven cavity, as well as in a 2-D rectangular channel with semi-circular and parabolic protrusions used by Gaver, Kute and Cortez. The solutions for the normal and shear stresses, velocity magnitude and streamlines were obtained and compared to the corresponding solutions of Gaver, Kute, Cortez and the finite-volume method.
High-Performance Architecture Using Fast Dynamic Reconfigurable Accelerators

System accelerators (ACCs) improve performance and break power and utilization walls. They can be implemented by fixed-function hard macros or reconfigurable logic such as field-programmable gate arrays (FPGAs). For systems running various applications, dynamic reconfigurable ACCs offer a very attractive feature; however, the reconfiguration time is an unavoidable overhead. This paper proposes high-performance architecture with fast dynamic reconfigurable FPGA ACCs (F-RACCs) based on a novel bitstream reprogramming method, which is feasible by using emerging technologies. The architecture includes CPU cores, caches, memories, ACCs, and network-on-chips. A portion of the computing tasks can be offloaded from CPUs to ACCs to improve performance. The ACCs can be reprogrammed rapidly to accommodate various functions required by wide spectrum of applications. The performance is evaluated by platform for ACC-rich architectural design and exploration, a gem5-based cycle-accurate full-system simulation platform. The 11 benchmark applications from different domains are evaluated. Comparing with systems using conventional FPGA ACCs partially configured using fastest configuration speed; this architecture improves system performance on all applications and achieves maximum $1.31\times $ and $2.82\times $ speedup using 1 and 12 ACC instances, respectively. It achieves maximum speedup of $94.93\times $ with one and $565.12\times $ with 12 F-RACCs over CPU software path with no ACCs.
Molecules are cool

The development of methods for slowing and trapping gaseous species has led to a renaissance in atomic physics, which is now also progressing into molecular/chemical physics. The latest advances come from two groups who have devised techniques that, in principle, provide new approaches for trapping molecules and spectroscopically studying them.
Injectable Multistage Nanovectors for Enhancing Imaging Contrast and Directed Therapy

Nanovectors are powerful tools for the systemic delivery of therapeutic and imaging agents in oncology. We have recently introduced multistage nanovectors (MSV), designed to overcome sequential biological barriers. The first stage, comprised of porous silicon microparticles, targets tumor-associated endothelium. Once arrested at the disease site, second-stage nanoparticles carrying the therapeutic and imaging agents are released into the tumor microenvironment by time-dependent degradation of the silicon carrier. Particles–cell interactions and degradation of MSV can be controlled by means of particle surface modifications. In this chapter, we will describe studies related to the MSV, focusing on fabrication, intracellular multisite trafficking, advanced therapeutic systems, and contrast agents.
Measuring the time course of selection during visual search.

In visual search tasks, observers can guide their attention towards items in the visual field that share features with the target item. In this series of studies, we examined the time course of guidance toward a subset of items that have the same color as the target item. Landolt Cs were placed on 16 colored disks. Fifteen distractor Cs had gaps facing up or down while one target C had a gap facing left or right. Observers searched for the target C and reported which side contained the gap as quickly as possible. In the absence of other information, observers must search at random through the Cs. However, during the trial, the disks changed colors. Twelve disks were now of one color and four disks were of another color. Observers knew that the target C would always be in the smaller color set. The experimental question was how quickly observers could guide their attention to the smaller color set. Results indicate that observers could not make instantaneous use of color information to guide the search, even when they knew which two colors would be appearing on every trial. In each study, it took participants 200–300 ms to fully utilize the color information once presented. Control studies replicated the finding with more saturated colors and with colored C stimuli (rather than Cs on colored disks). We conclude that segregation of a display by color for the purposes of guidance takes 200–300 ms to fully develop.
Does the season of diagnosis affect survival of cutaneous melanoma

e21064Background: Incidence of cutaneous melanoma (CM) is known to have seasonal variations. We aimed to study the survival pattern of CM in the United States based on the season of diagnosis. Meth...
Recategorization of Video Game Genres

While the categories that are typically used to discriminate games have been useful in the past, more recently game mechanics have become utilized by a wider range of games, leading to earlier defi...
Protons and Prejudice: Finding Sense and Sensibility in the Development of a Costly Medical Therapy

Proton beam therapy (PBT) is a promising but costly treatment option for cancer. This chapter provides an overview of the unique physical properties of protons and puts into context the current state of PBT in the United States and abroad. Fierce competition for market share has driven rapid proliferation of proton centers. PBT has become a therapy seeking an indication, especially in common malignancies such as prostate cancer, and is often marketed as superior despite clear comparative efficacy research to demonstrate a benefit. Restoring sense and sensibility to PBT utilization is critical to the long-term success of this technology.
Machine Learning for Real-Time Diagnostics of Cold Atmospheric Plasma Sources

Real-time diagnostics of cold atmospheric plasma (CAP) sources can be challenging due to the requirement for expensive equipment and complicated analysis. Data analytics that rely on machine learning (ML) methods can help address this challenge. In this paper, we demonstrate the application of several ML methods for real-time diagnosis of CAPs using information-rich optical emission spectra and electro-acoustic emission. We show that data analytics based on ML can provide a simple and effective means for estimation of operation-relevant parameters such as rotational and vibrational temperature and substrate characteristic in real-time. Our findings indicate a great potential promise for ML for real-time diagnostics of CAPs.
Behavioral biases and political actors : Three examples from US international taxation

The literature on behavioral public finance has tended to focus on the biases of taxpayers. However, politicians and government agents are human as well and can be expected to show the same biases that we are all subject to. This chapter will examine three examples of availability heuristic arguably influencing political actors and the unintended consequences of their reactions. The examples are all from US international tax rules: the foreign investment in real property tax act (FIRPTA) (1980), the exit tax on US citizens who expatriate (2008) and the enforcement of withholding tax on dividend equivalents (2010).
Flexible parking reservation system and pricing: A continuum approximation approach

Abstract Reservation-based parking systems have the merit of eliminating vehicle cruising for parking. While many long-period (e.g., daily) parking reservation services are already in use, short-period (e.g., hourly) parking reservation remains a huge challenge due to the high uncertainty of customer arrivals and departures. To mitigate the service failure caused by random late departures of customers, we propose a new flexible reservation mechanism in which the reservation is no longer restricted to a specific location at a specific time, but tolerates predetermined spatiotemporal flexibility instead. With a pricing instrument designed for such parking flexibility, customers can coordinate to significantly reduce the reservation failure rate, resulting in an optimal system equilibrium benefiting the entire society. Due to the complex nature of this system, a continuum approximation framework is used to provide tractable analysis for a large-scale urban parking system. We can successfully provide accurate system management decision support with a bounded optimality gap and analytical insights.
Passive Intermodulation Source Localization Based on Emission Source Microscopy

Emission source microscopy (ESM) technique can be used for localization and characterization of electromagnetic interference sources by measuring the magnitude and phase of the electromagnetic field in the far-field zone. This article presents a method which uses ESM to locate sources of passive intermodulation (PIM). Compared to the traditional methods of PIM source localization techniques including mechanical manipulation of potential sources and near-field scanning, the proposed ESM-based approach does not require access to the devices under test allowing to detect the PIM sources at relatively large distances. Moreover, the influence of background PIM generated by surrounding environment can be reduced by ESM focusing. The high-quality maps of reconstructed PIM sources can be obtained by using ESM. The feasibility of manual sparse ESM scanning, which is more practical in realistic settings is also demonstrated.
Generation of Raw RPPA Data and Their Conversion to Analysis-Ready Data

Reverse phase protein array (RPPA) provides investigators with a powerful high-throughput, quantitative, cost-effective technology for functional proteomics studies. It is an antibody-based technique with procedures similar to that of Western blots. RPPA has a wide variety of applications that range from pharmacodynamics and drug sensitivity assessment to biomarker discovery, subtype classification, and prediction of patient prognosis and response to targeted therapy. In this paper, we describe the technology, its limitations, and some solutions to overcome them. We discuss the steps necessary to obtain raw RPPA data and convert them into robust, high-quality, analysis-ready data. We then illustrate the utility of the platform by highlighting some biomarkers and drug responses of cancer cell lines that confirm previous findings, as a means to validate the platform and the methods presented here.
Sideline concussion assessment: the current state of the art

More than 200 million American adults and children participate in organized physical activity. Growing awareness has highlighted that concussion, especially when repeated, may be associated with prolonged neurological, cognitive, and/or neuropsychiatric sequelae. Objective diagnosis of concussion remains challenging. Although some concussion symptoms may be apparent even to nonmedical observers, diagnosis and removal from play for evaluation depend on validated assessment tools and trained, vigilant healthcare personnel. Over the past 2 decades, sideline concussion measures have undergone significant revision and augmentation to become more comprehensive batteries in order to detect a wide spectrum of symptomatology, eg, neurocognitive function, postconcussive symptoms, gait/balance, and saccadic eye movements. This review summarizes the current state-of-the-art concussion evaluation instruments, ranging from the Sports Concussion Assessment Tool (SCAT) and tools that may enhance concussion detection, to near-term blood-based biomarkers and emerging technology (eg, head impact sensors, vestibulo-ocular/eye-tracking, and mobile applications). Special focus is directed at feasibility, utility, generalizability, and challenges to implementation of each measure on-field and on the sidelines. This review finds that few instruments beyond the SCAT provide guidance for removal from play, and establishing thresholds for concussion detection and removal from play in qualification/validation of future instruments is of high importance. Integration of emerging sideline concussion evaluation tools should be supported by resources and education to athletes, caregivers, athletic staff, and medical professionals for standardized administration as well as triage, referral, and prevention strategies. It should be noted that concussion evaluation instruments are used to assist the clinician in sideline diagnosis, and no single test can diagnose concussion as a standalone investigation.
32 – THE ECONOMICS OF GOVERNMENT FAILURE

Publisher Summary This chapter presents the economics of government failure. Critics of the government agencies respond that many local governments are too small to achieve economies of scale, and others are so large that they operate with bloated, costly, multi-tiered bureaucracies. They also point out that the apparent savings of government agencies that do not pay sales, excise, and income taxes are illusory, because the public must pay higher taxes as a result. Finally, they criticize public personnel systems that fail to relate pay to performance. This happens for a variety of reasons, including patronage and civil service, political rather than economic decisions, budgeting processes and incentive systems that encourage agency growth, and the absence of competition—depriving public agencies of standards against which to compare their performance. Studies conclude that private firms operating under municipal contracts collect residential refuse at much lower cost than city agencies do. The studies estimate that municipal collection is from 14 to 43% more expensive than contract collection; and the contract price includes taxes paid by private firms to government. In effect citizens get a rebate—in the form of various government services—even from the lower contract price. In exploring opportunities for private contracting, refuse collection looks like a good place to begin, if only because it has been studied most thoroughly. However, other services also lend themselves to contracts and should be explored.
Assessing the hierarchy of long-term environmental controls on diatom communities of Yellowstone National Park using lacustrine sediment records

Chraibi VLS, Fritz SC. 2020. Assessing the hierarchy of long-term environmental controls on diatom communities of Yellowstone National Park using lacustrine sediment records. Lake Reserv Manage. 36...
Internal agglomeration and productivity: Evidence from microdata

Research Summary: We study how internal agglomeration—geographic clustering of business establishments owned by the same parent company—influences establishment productivity. Using Census microdata on the population of U.S. hotels from 1987‐2007, we find that doubling the intensity of internal agglomeration is associated with a productivity increase of about 2% in pre‐existing establishments. We consider several mechanisms that may be driving the productivity effect and find evidence consistent with the idea that an economically meaningful component of the productivity effect is due to knowledge transfer between internally agglomerated establishments. We replicate our main findings with Census microdata on the full population of U.S. restaurants from 1987‐2007, suggesting that the internal agglomeration effects we document may generalize broadly to other industries with multi‐unit firms. Managerial Summary: Internal agglomeration is the geographic clustering of business establishments owned by the same parent company. This paper uses detailed Census data on hotels and restaurants to show how internal agglomeration influences performance. Interestingly, knowledge sharing between owned establishments in the same metropolitan area appears to be a key driver of the internal agglomeration effect.
Quantity or Quality?: Assessing the Role of Household Structure and Parent-Child Relationship in Juvenile Delinquency

Research investigating the risk factors for delinquency has found that single-parent households are more criminogenic than two-parent households. Using data (N = 4,626) from the National Longitudin...
Selective Wireless Stimulation of Rat Sciatic Nerve

Chronic stability of functional performance is a significant challenge to the success of implantable devices for neural stimulation and recording. Integrating wireless technology with typical microelectrode array designs is one approach that may reduce instances of mechanical failure and improve the long-term performance of neural devices. We have investigated the long-term stability of Wireless Floating Microelectrode Arrays (WMFAs) implanted in rat sciatic nerve, and their ability to selectively recruit muscles in the hind limb via neural stimulation. Thresholds as low as 4.1 μA were able to generate visible motion of the rear paw. Each implanted device (n=6) was able to selectively recruit plantar flexion and dorsiflexion of the rear paw, and selective stimulation of both movements was achieved throughout the study period. The evoked limb motion was electrode specific and was dependent on location within the fascicular structure of the nerve. Motor thresholds and movement patterns remained stable for more than 8 weeks after device implantation. No major changes in limb function were observed between the implanted and contralateral limb, or between implanted animals and control group animals. The results of this study show that WFMAs with intrafascicular electrodes implanted in a healthy peripheral nerve can provide stable and selective motor recruitment, without altering overall limb function.
Special issue on business and financial data: introduction

In September of 2019, editor Celia Ross approached me about serving as the guest editor of a special issue on business and financial data. When we embarked upon this project, we had no way of knowi...
Gender, Campus Sexual Violence, Cultural Betrayal, Institutional Betrayal, and Institutional Support in U.S. Ethnic Minority College Students: A Descriptive Study:

Women and ethnic minorities are at increased risk for campus sexual violence (CSV). Due to inequality, within-group victimization in marginalized communities includes cultural betrayal. Universitie...
Thresholded Wirtinger Flow for Fast Millimeter Wave Beam Alignment

The objective of this paper is to estimate millimeter wave (mmWave) channels based on the magnitude of the received complex measurements. This is motivated by the observation that in practice, a random carrier frequency offset usually occurs for each transmission and corrupts the phase of the measurement. The problem is cast into a non-convex optimization framework, and solved through a thresholded Wirtinger flow (TWF) based approach. Due to the complex signals involved in the problem, and the constraints imposed by phase shifters, existing design and analysis of TWF are not directly applicable. To overcome these challenges, a structured design of the combiner (precoder) is investigated, which naturally leads to a novel initialization scheme for the TWF algorithm. Simulation results indicate that the proposed approach can successfully recover multiple paths in an mmWave channel and the required number of measurements scales mildly with the dimension of the array size.
Multiplicative Weights Algorithms for Parallel Automated Software Repair

Multiplicative Weights Update (MWU) algorithms are a form of online learning that is applied to multi-armed bandit problems. Such problems involve allocating a fixed number of trials among multiple options to maximize cumulative payoff. MWU is a popular and effective method for dynamically balancing the trade-off between exploring the value of new options and exploiting the information already gained. However, no clear strategy exists to help practitioners choose which of the several algorithmic designs within this family to deploy. In this paper, three variants of parallel MWU algorithms are considered: Two parallel variants that rely on global memory, and one variant that uses distributed memory. The three variants are first analyzed theoretically, and then their effectiveness is assessed empirically on the task of estimating distributions in the context of stochastic search for repairs to bugs in software. Earlier work on APR suffers from various inefficiencies, and the paper shows how to decompose the problem into two stages: one that is embarrassingly parallel and one that is amenable to MWU. We then model the cost of each MWU variant and derive the conditions under which it is likely to be preferred in practice. We find that all three MWU algorithms achieve accuracy above 90% but that there are significant differences in runtime and total cost. When 90% accuracy is sufficient and evaluating options is expensive, such as in our use case, we find that the algorithm that uses global memory and has high communication cost outperforms the other two. We analyze the reasons for this surprising result.
First Philosophy and Natural Philosophy in Descartes

Descartes was both metaphysician and natural philosopher. He used his metaphysics (among other things) to ground portions of his physics (or natural philosophy, or science of nature). However, as should be a commonplace but is not, he did not think he could spin all of his physics out of his metaphysics a priori, and in fact he both emphasized the need for appeals to experience in his methodological remarks on philosophizing about nature and constantly appealed to experience in describing his own philosophy of nature.1 It remains unclear exactly what he took to be amenable to empirical support, and how his appeal to experience was squared with his notorious demand for absolute certainty in matters philosophical.
Determinants of adolescent suicidal ideation: rural versus urban.

PURPOSE: The existing literature on disparities between rural and urban adolescents as they pertain to suicidal behavior is limited; identifying these distinctions could be pivotal in the decision of how to efficiently allocate scarce resources to reduce youth suicide rates. This study aimed to identify dissimilarities in predictors of suicidal ideation across the rural/urban threshold, as ideation is one of the most important predictors of suicide. Given that substance abuse is generally considered one of the strongest risk factors for suicidal behavior, a secondary aim was the isolation of the differences in usage of particular substances between rural and urban adolescents, and their effects on the likelihood of suicidal ideation, which is something that previous studies have had difficulty addressing. METHODS: A global test determined that individual predictors of suicidal ideation differed across rural and urban adolescents, and simply including a rural/urban indicator in a multiple regression would result in biased estimates. Therefore, this paper assessed rural/urban differences among a comprehensive list of traditionally perceived risk and protective factors via bivariate analyses and separate multiple full-information-maximum-likelihood regressions, which account for missing data. FINDINGS: Somewhat contrary to the extant literature, the findings indicate important differences among predictors of suicidal ideation for rural and urban youths. CONCLUSIONS: These differences should be taken into consideration when developing plans to combat adolescent suicide. The results further indicate that analyzing potential predictors of suicidal ideation for rural and urban adolescents via bivariate analyses alone, or a rural/urban indicator in a multiple regression, is not sufficient. Language: en
Audiometric Thresholds: Stimulus Considerations in Sound Field and Under Earphones

Purpose This study evaluates a new stimulus, FREquency Specific Hearing assessment (FRESH) noise, to obtain hearing thresholds and reviews the potential pitfalls of using narrow band noise. Method ...
Meta Warrick Fuller's Mary Turner: and the Memory of Mob Violence

In 1919 the sculptor Meta Warrick Fuller modeled the statuette Mary Turner: A Silent Protest against Mob Violence . One of the earliest three-dimensional works of art to address the subject of lynching, the sculpture was dedicated to the memory of Turner, a nineteen-year-old pregnant African American woman who had been seized and murdered by a white mob one year earlier. Fuller’s Turner bears no traces of torture and rises with her child from an abstracted heap of her attackers. This paper considers the inclusions and exclusions Fuller made in interpreting the memory of Turner’s lynching and the riot responsible for it. It seeks to understand the sculpture not only as a response to the lynching itself but also as an intervention in ways in which contemporary organizations like the National Association for the Advancement of Colored People (NAACP) communicated acts of racial violence to the greater public through expository text and imagery.
Contributions of principal neocortical neurons to magnetoencephalography and electroencephalography signals

A realistically shaped three-dimensional single-neuron model was constructed for each of four principal cell types in the neocortex in order to infer their contributions to magnetoencephalography (MEG) and electroencephalography (EEG) signals. For each cell, the soma was stimulated and the resulting intracellular current was used to compute the current dipole Q for the whole cell or separately for the apical and basal dendrites. The magnitude of Q is proportional to the magnetic field and electrical potential far from the neuron. A train of spikes and depolarization shift in an intracellular burst discharge were seen as spikes and an envelope in Q for the layer V and layer II/III pyramidal cells. The stellate cells lacked the envelope. As expected, the pyramidal cells produced a stronger Q than the stellate cells. The spikes produced by the layer V pyramidal cells (n = 4) varied between -0.78 and 2.97 pA m with the majority of the cells showing a current toward the pia (defined as positive). The basal dendrites, however, produced considerable spike currents. The magnitude and direction of dipole moment are in agreement with the distribution of the dendrites. The spikes in Q for the layer V pyramidal cells were produced by the transient sodium conductance and potassium conductance of delayed rectifier type; the conductances distributed along the dendrites were capable of generating spike propagation, which was seen in Q as the tail of a triphasic wave lasting several milliseconds. The envelope was similar in magnitude (-0.41 to -0.90 pA m) across the four layer V pyramidal cells. The spike and envelope for the layer II/III pyramidal cell were 0.47 and -0.29 pA m, respectively; these values agreed well with empirical and theoretical estimates for guinea pig CA3 pyramidal cells. Spikes were stronger for the layer IV spiny stellate (0.27 pA m) than the layer III aspiny stellate cell (0.06 pA m) along their best orientations. The spikes may thus be stronger than has been previously thought. The Q for a population of stellate cells may be weaker than a linear sum of their individual Q values due to their variable dendritic geometry. The burst discharge by pyramidal cells may be detectable with MEG and EEG when 10 000-50 000 cells are synchronously active.
Spin observables in nucleon-nucleus scattering

The curse of inelastic nucleon scattering and charge exchange has always been the enormous complexity of the nucleon-nucleon (N-N) interaction. This complexity, however, can also be viewed as the ultimate promise of nucleons as probes of nuclear structure, Given an adequate theoretical basis, inelastic nucleon scattering is capable of providing information not obtainable with other probes.
Learning by Learning Roles: A Virtual Role-Playing Environment for Tutoring

People will invest extraordinary time and effort into learning how to play and win a game. Virtual role-playing environments can be a powerful mechanism of instruction, provided they are constructed such that learning how to play and win the game contributes to a player's understanding of real-world concepts and procedures. This paper describes a pedagogical architecture and an implemented application where students assume a role in a simulated multi-media environment and learn about the real world by competing with other players. The game, which teaches principles of micro-economics, is an implementation of a networked, multiplayer, simulation-based, interactive multi-media, educational environment that illustrates the principles of learning by learning roles.
A correlated model of the nuclear photoeffect

A model is constructed for direct photonuclear reactions at intermediate energies, which incorporates the effects of short-range correlations in the initial and final nuclear states. The model is the first consistent one of this type in that i) spurious contributions to the transition amplitude due to nonorthogonality of approximate correlated initial and final nuclear states are eliminated and ii) the model transition amplitude is developed in a well-behaved cluster expansion, with terms arranged in increasing order in a smallness parameter characterizing the correlations. The zeroth-order term gives the conventional shell model description. Explicit expressions for the transition amplitude valid to first order in the effects of the correlations are derived for use in analyses of the (γ,N) and (γ, 2N) data, under the special assumption that the correlations in initial and final states are of the same Jastrow form.
World trade and the environment

This paper is the text of a speech given by the author at a recent conference. As the title implies, it discusses the relationship between economic activity and the environment, and emphasises that they are not incompatible. Indeed, a reduction in the former decreases the resources necessary to protect the latter. He concludes by arguing the case for flexibility in international standards, in order to allow Third World countries to compete more equally and to cope with local differences.
Simple harmonic motion of tropomyosin : proposed mechanism for length-dependent regulation of muscle active tension

A simple harmonic theory is proposed to describe the regulatory mechanism of tropomyosin in the activation of muscle contraction. The theory proposes that activation-associated displacement of tropomyosin is inherent to tropomyosin, a consequence of the molecule's large-scale vibrational motion (5-10 A root mean square displacement). In association with thin filament the vibrational motion may become less complex, approaching the ideal case of simple harmonic motion. The degree of activation increases as the amplitude of the simple harmonic motion increases, causing tropomyosin to shorten lengthwise, shiftings its position from the periphery of thin filament (OFF) to the actin groove (ON). The amplitude may be regulated in a rectilinear manner by the thick filament electrostatic force, the thin filament hydrophobic force, and the Ca(2+)-dependent force of the troponin complex. The radial and tangenital components of the resultant force may vary as the muscle is stretched, regulating maximum active tension and Ca2+ sensitivity, respectively. This may represent the molecular basis for Starling's law of the heart. The mechanism may be important for describing the regulatory mechanism of tropomyosin in smooth muscle and nonmuscle cells and may facilitate a clinically relevant understanding of the effects of pH, Mg2+ concentration, ionic strength, and ethanol on the regulation of active tension.
Metabolism of 4-Chloro-2-Methylphenoxyacetic Acid by Soil Bacteria

A microorganism capable of degrading 4-chloro-2-methylphenoxyacetic acid (MCPA) was isolated from soil and identified as Flavobacterium peregrinum. All of the chlorine of MCPA was released as chloride, and the carboxyl-carbon was converted to volatile products by growing cultures of the bacterium, but a phenol accumulated in the medium. The phenol was identified as 4-chloro-2-methylphenol on the basis of its gas chromatographic and infrared characteristics. Extracts of cells of F. peregrinum and of a phenoxyacetate-metabolizing Arthrobacter sp. dehalogenated MCPA and several catechols but not 4-chloro-2-methylanisole. The Arthrobacter sp. cell extract was fractionated, and an enzyme preparation was obtained which catalyzed the conversion of MCPA to 4-chloro-2-methylphenol. The latter compound was not metabolized unless reduced nicotinamide adenine dinucleotide phosphate was added to the fractionated extract. The phenol in turn was apparently oxidized to a catechol by components of the enzyme preparation.
R(+)‐ and S(−)‐α‐Phenylethylamine

R(+)- and S(−)-α-phenylethylamine product: (S)-(−)-α-Phenylethylamine intermediate: (−)-amine (+)-hydrogen tartrate salt product: (R)-(+)-α-Phenylethylamine intermediate: (+)-amine sulfate Keywords: resolution
African Englishes: acoustic analysis of vowels: African Englishes: acoustic analysis of vowels

ABSTRACT: This paper focuses on acoustic analysis of African English (AfrE) vowels produced by a controlled sample of speakers from Kenya, Ghana, and Zimbabwe. Adopting quantitative methods of data sampling and analysis, and holding dialectal factors as homogeneous as possible, this exploratory study subjects Schmied's (1991a) claim – that a major source of regional variation is the ‘deviation’ in the production of RP central vowel [] (as in bird) – to empirical scrutiny. Schmied contends that [] backs and lowers to [] in West African English, fronts and lowers to [a] or fronts to [e] in East African English, while in (Black) South African English it fronts to [e]. However, analysis of acoustic waveforms of AfrE vowels, produced by educated speakers of Bantu and Kwa languages, partially corroborate Schmied's contention. For instance, Ghanaian and Zimbabwean respondents in this study front the RP vowel [] to [e], while Kenyans lower it to [a]. The paper provides a methodological framework that will at least address some research concerns voiced over the years: lack of “objective, systematic study” (Abdulaziz 1991: 393), “deficiency in methodology” (Adegbija 1994: 53), and “overgeneralization” (Simo Bobda 2000: 264). Sustained empirical studies could eventually lead to a fresh perspective on AfrE's phonological variation.
Nonequilibrium evaporation of molten-metal drops in an alternating magnetic field

Abstract A lumped analysis of molten-metal droplets moving in an inhomogeneous magnetic field and evaporating in inert-gas surroundings by using three nonequilibrium evaporation models is performed. Results show marked differences (up to 1000 K) in drop temperatures for the diffusion and vacuum-like, high-velocity models but relatively low differences (less than 8%) in the final size of the drop radius. A quasi-steady diffusion-convection model accounting for finite relative velocity of droplets with respect to the ambient gas is considered as an intermediate case between these two limits. Ambient gas flowing opposite to the direction of droplet motion can improve the efficiency of the evaporation process.
Automated HST/STIS reference file generation pipeline using OPUS

Bias and Dark reference files are part of the basic reduction of the CCD data taken by the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). At STScI, the STIS team has been creating these reference files using the Bias and Dark Pipeline. This pipeline system starts with automatic retrieval of bias and dark exposures from the HST archive after they have been ingested. After data retrieval, a number of automatic scripts is executed in a manner compatible with the OPUS pipeline architecture. We encourage any group looking to streamline a stepwise calibration process to look into this software.
VEGF and Delta-Notch: interacting signalling pathways in tumour angiogenesis

Tumour angiogenesis has become an important target for antitumour therapy, with most current therapies aimed at blocking the VEGF pathway. However, not all tumours are responsive to VEGF blockers, and some tumours that are responsive initially may become resistant during the course of treatment, thus there is a need to explore other angiogenesis signalling pathways. Recently, the Delta-Notch pathway, and particularly the ligand Delta-like 4 (Dll4), was identified as a new target in tumour angiogenesis. An important feature in angiogenesis is the manifold ways in which the VEGF and Delta-Notch pathways interact. The emerging picture is that the VEGF pathway acts as a potent upstream activating stimulus for angiogenesis, whereas Delta-Notch helps to guide cell fate decisions that appropriately shape the activation. Here we review the two signalling pathways and what is currently known about the ways in which they interact during tumour angiogenesis.
Invisible Linkages: A Regional Perspective of East Asian Political Economy

This article studies East Asian political economy from a regional perspective. The Asian financial crisis showed that East Asian economies are highly regionalized. However, the linkages among Asian economies, mostly informal in nature, often appear “invisible” to many in the West, who focus more on the states and formal institutions. Drawing on a broad set of literature mostly in Asian languages, this paper provides a systematic study of informal integration in East Asia, which consists of not only regional production networks, but also ethnic Chinese business networks and subregional economic zones. It finds that the three informal mechanisms have formed an interrelated pattern of regional integration in East Asia. The nature of the economic networks is very useful in explaining the Asian crisis and the different performances of East Asian economies in the crisis. The crisis has also resulted in profound changes in informal integration. While the Japanese-led production networks have been greatly weakened, the Chinese Economic Area is rising, driven by the ethnic Chinese business networks and subregional economic zones. As a result, the Japan-dominated “flying geese pattern” has been broken. The connections between Greater China and the United States have also been enhanced and are out-competing the Japanese production networks. Many of the new developments have been ignored in the West but they are key factors that will shape the future of Asian and World political economy.
Some limitations of labeled compounds in radiobiological investigations of deoxyribonucleic acid (DNA) synthesis.

The results of recent biophysical and biochemical investigations have demonstrated that careful experimental design is necessary to avoid erroneous or misleading results. The ratio of the speciflc activity of the labeled compound in the irradiated biological system to the labeled compound in the control is usually interpreted as a measure of the effects of irradiation on a biological process. Since specific activity of DNA is dependent upon the fraction of cells synthesizing DNA and the amount of DNA synthesized per cell per unit of time, information is needed about DNA synthesis within populations of cells. Biochemical studies alone do not provide this information. The rate of synthesis during DNA replication may be exponential. Differences in the time sequence between the irradiated and control populations of cells of synchronous biological systems will give differences in the ratio of the specific activities of labeled compounds. A review of the results reported on the effects of irradiation on DNA synthesis as measured by labeled precursors suggests the following. The finding of two components of the dose-response curve measured with labeled compounds indicates that irradiation affects more than one process involved in the biosynthesis of DNA. Labeled precursors injected during or shortly after irradiationmore » should give results which should more accurately reflect the effects of irradiation on the DNA synthetic process. Relative changes in the rate of synthesis and relative changes in the population of cells in the irradiated and paired control biological systems make quantitative results between the dose delivered and the effects of DNA synthesis unlikely if the labeled precursors are not administered immediately after irradiation. Labeled precursors injected from several hours up to days after irradiation make the results of the effects of irradiation on DNA synthesis difficult or impossible to evaluate. The finding that DNA synthesis is depressed for days after irradiation probably involves the effects of irradiation on cell processes other than DNA synthesis. Depression of the uptake of the labeled precursors is in all probability an indirect effect mediated through disturbances in other cell processes such as mitosis. It is therefore considered that coordinated biophysical studies on individual cells and biochemical studies on total populations of cells offer one of the best approaches to obtain a better understanding of irradiation effects on DNA. Coordinated in vivo and in vitro studies should be more effective than either study made independently in the attempt to gain a better understanding of the biological effects of irradiation.« less
School-Based Enterprises and Environmental Sustainability.

This article uses an educational framework of environmental sustainability to examine the production process and the final products and services delivered by School-Based Enterprises (SBEs). Whereas the fledging literature on SBEs has extolled their many benefits for improving learning, it has been slow to acknowledge the importance of promoting ecological awareness through vocational education. This article defends the importance of “greening” SBEs in order to raise students’ and teachers’ consciousness about the importance of environmental stewardship, and it also explores key limitations faced by SBEs that attempt to follow such a framework. This environmental educational framework is used to analyze qualitatively the actual practices of SBEs in two public secondary schools in Colombia, South America.
Viral versus chemical hepatocarcinogenesis

Summary Almost all experimental studies on hepatocarcinogenesis have been performed on models induced by chemicals. The human hepatocellular carcinoma (HCC), a highly malignant tumor, particularly frequent in the Far East and in Africa, is overwhelmingly associated with hepatitis B virus (HBV) infections and only very rarely is it caused by chemicals. This raises the question as to what degree observations on the preferentially studied chemical carcinogenesis apply to human HCC. This question is timely, since a woodchuck model has been developed in which laboratory infection with a hepadna virus, biologically and genomically similar to HBV, regularly produces HCC in prolonged surface antigen carrier woodchucks. Permanent surface antigen carriage by itself may also be a risk factor. A comparison, based on available observations of chemical and hepadna viral carcinogenesis, was attempted on four aspects: (1) histologic features, (2) growth patterns, (3) growth factors, and (4) molecular biological observations. At this time, only few conclusions can be drawn, mainly on a morphological and molecular biological basis. In the initial stage, chemicals cause mutations of very few bases, while in hepadna viral infections long sequences are inserted into both strands of chromosomal DNA. Additional studies appear to be indicated, to the greatest degree with existing methods and primarily on hepadna viral carcinogenesis. A key question is whether the active necroinflammation, preceding or observed at the time the HCC is recognized, in woodchuck and also in human chronic HBV infections is a promoting event or a secondary reaction. Additional therapeutic strategies, specific for hepadna viral carcinogenesis, can be considered, particularly elimination of hepatocytes carrying integrated viral sequences and prevention or suppression of the promoting necroinflammation. Success in HCC may be applicable to cancers related to papilloma virus in other organs, for instance, the female genital tract.
Serum FSH, LH, and Prolactin in Adult Ovariectomized Mice Bearing Silastic Implants of Estradiol: Responses to Social Cues

The effect of silastic implants containing 0-5000 mcg of 17beta-estr adiol on serum concentrations of luteinizing hormone (LH) follicle stimulating hormone (FSH) prolactin and their relationship to social cues was studied in adult ovariectomized mice. The normal variation in serum LH levels that is observed during the estrus cycle was established by this range of doses. However the high levels of prolactin observed during the peri-ovulatory stage of the cycle were absent and the treatment fialed to suppress FSH levels to the extent that they correlated with any stage characteristic of the estrus cycle. Serum gonadotropin levels were not markedly altered by housing in isolation in isolation and exposed to the odor of male urine and in groups of 6 in animals receiving the high dose of estradiol. However those receiving the low dose responded to the presence of male urine by exhibiting a marked increase in serum LH levels but with no marked effect on FSH and prolactin and to grouping with an increase in prolactin levels a decrease in LH and no change in FSH. The results suggest that animals receiving the low dose of estradiol show a normal r esponse to social cues.
Iron accumulation and neurotoxicity in cortical cultures treated with holotransferrin

Nonheme iron accumulates in CNS tissue after ischemic and hemorrhagic insults and may contribute to cell loss. The source of this iron has not been precisely defined. After blood-brain barrier disruption, CNS cells may be exposed to plasma concentrations of transferrin-bound iron (TBI), which exceed that in the CSF by over 50-fold. In this study, the hypothesis that these concentrations of TBI produce cell iron accumulation and neurotoxicity was tested in primary cortical cultures. Treatment with 0.5-3mg/ml holotransferrin for 24h resulted in the loss of 20-40% of neurons, associated with increases in malondialdehyde, ferritin, heme oxygenase-1, and iron; transferrin receptor-1 expression was reduced by about 50%. Deferoxamine, 2,2'-bipyridyl, Trolox, and ascorbate prevented all injury, but apotransferrin was ineffective. Cell TBI accumulation was significantly reduced by deferoxamine, 2,2'-bipyridyl, and apotransferrin, but not by ascorbate or Trolox. After treatment with (55)Fe-transferrin, approximately 40% of cell iron was exported within 16h. Net export was increased by deferoxamine and 2,2'-bipyridyl, but not by apotransferrin. These results suggest that downregulation of transferrin receptor-1 expression is insufficient to prevent iron-mediated death when neurons are exposed to plasma concentrations of TBI. Chelator therapy may be beneficial for acute CNS injuries associated with loss of blood-brain barrier integrity.