cssi/SciSciGPT-SciSciNet huggingface dataset:
National Gross Domestic Product, Science Interest, and Science Achievement: A Direct Replication and Extension of the Tucker-Drob, Cheung, and Briley (2014) Study

We replicated the study by Tucker-Drob, Cheung, and Briley (2014), who found that the association between science interest and science knowledge depended on economic resources at the family, school, and national levels, using data from the 2006 Programme for International Student Assessment (PISA). In more economically prosperous families, schools, and nations, student interest was more strongly correlated with actual knowledge. Here, we investigated whether these results still held despite substantial changes to educational and economic systems over roughly a decade. Using similar data from PISA 2015 ( N = 537,170), we found largely consistent results. Students from more economically advantaged homes, schools, and nations exhibited a stronger link between interests and knowledge. However, these moderation effects were substantially reduced, and the main effect of science interest increased by nearly 25%, driven almost entirely by families of low socioeconomic status and nations with low gross domestic product. The interdependence of interests and resources is robust but perhaps weakening with educational progress.
Newtonian Kinetics of a Rigid Body

Chasle's theorem states that the general motion of a rigid body can be represented as a superposition of a translation following any point in the body and a pure rotation about that point. Kinematics studies are concerned only with the description of that motion. The developments in this chapter will disclose how the motion is related to the force system acting on the body. The resultant force may be regarded intuitively as the net tendency of the force system to push a body, so it may be expected to be related to the translational effect. Similarly, the resultant moment may be considered to be the net rotational effect. We shall confirm and quantify these expectations in the following presentation for general spatial motion, and then specialize the derived principles for the case of planar motion. Fundamental Principle Newton's laws govern the motion of a particle. A rigid body may be treated as a collection of particles whose motions are not independent. In the first part of this chapter, we shall derive the basic kinetics principles for rigid-body motion. The foundation for these derivations is Newton's second law, which describes inertial effects, and the third law, which describes the nature of the force system. Basic Model From a philosophical perspective, we initially recognize the atomic nature of matter by considering a body to consist of N particles having mass m i .
Polar Infromation: An International Approach

Author(s): West, Sharon M.; McCarthy, Paul H. | Abstract: PolarPac - bibliography on Arctic and Antarctic information
In Search of Deeper Learning: The Quest to Remake the American High School: by Jal Mehta and Sarah Fine, Cambridge, MA, Harvard University Press, 2019, 454 pp., $29.95 (hardcover), ISBN: 978-0-674-98839-2

Much research focused on policy and organization at the federal, state, or district levels neglects to consider pedagogy within schools and classrooms. In Search of Deeper Learning: The Quest to Re...
Laparoscopic pancreatectomy for cancer in high volume centers is associated with an increased use and fewer delays of adjuvant chemotherapy.

Abstract Background This study aimed to investigate the relationship between hospital case volume, surgical approach and AC-use in patients who underwent pancreatectomy for pancreatic ductal adenocarcinoma (PDAC). Methods Patients were divided into quartiles by institutional pancreatectomy case volume, resection type (pancreaticoduodenectomy [PD], distal pancreatectomy [DP], or total pancreatectomy [TP]) and surgical approach (laparoscopic vs. open). The rates and contributing factors of AC administration and delay >90 days were compared among volume quartiles and surgical approaches. Results This study identified 23,494 patients who had undergone pancreatectomy for PDAC between 2010 and 2016 and met inclusion criteria. After correcting for confounders, compared to low volume hospitals patients at high-case-volume hospitals had the highest rates of AC administration after PD and DP. Moreover, compared to open surgery for all resection types, laparoscopic surgery was associated with a higher rate of AC use at high and highest-case-volume hospitals and less delay to chemotherapy at high-volume hospitals. For DP, laparoscopic approach had a positive impact on AC delay >90-day at the highest volume institutions only. Conclusions Laparoscopic surgery for pancreatic cancer leads to higher utilization and lower probability of delay of AC in high and highest volume hospitals.
Transient Stability Microgrid Model for Arctic Community Integration

This paper utilizes realistic data from a remote Alaskan microgrid to provide a microgrid model for transient stability studies. The simulated model is based on the village of Igiugig in the southwest of Alaska. The model details the design of diesel generators, medium and low voltage feeders, vertical axis wind turbine and voltage drop at the point of utilization. The produced model captures a very accurate transient response of the microgrid. The modeling and simulations were carried out in MATLAB/SIMULINK and the model is validated against the measured response of the actual microgrid during a symmetrical fault.
Moral Reasoning in “the World”:

While moral theology fundamentally relies on human reason, scholarship on social sin now raises complex questions about the connection between understanding and moral responsibility. Considering th...
Einfluß von Fehlerquellen auf die Genauigkeit der Versuchsergebnisse

Jene Faktoren, die nicht nur den Versuchsvorgang, sondern auch die rechnerische Auswertung beeinflussen, wurden im Abschnitt II behandelt. Eine Reihe anderer Faktoren, welche die Genauigkeit der Versuche beeinflussen, sollen in diesem Abschnitt besprochen werden.
Thalamic Atrophy Over Time in Relapsing Forms of MS: A Large, 5-year, Observational MRI Study (S29.006)

OBJECTIVE: To describe the longitudinal evolution of thalamic atrophy in MS subjects in a group-level analysis. BACKGROUND: Thalamic atrophy is detected early in MS. It is related, in part, to white matter lesions within thalamocortical projections. Longitudinal rate of decline over time is lacking. Thalamic atrophy should occur at a faster rate in MS compared to healthy controls (HC) and as MS worsens. DESIGN/METHODS: 522 subjects with relapsing forms of MS [CIS(90);RR(394);SP(38)] were followed annually for 5 years with 3T MRI scans using a standardized protocol, including a 1mm3-resolution 3D T1-sequence (2,492 timepoints). Lesion masks for inpainting were created prior to submitting images to FreeSurfer’s longitudinal processing stream (v5.3) for automated segmentation. 69 HC were scanned serially using the same protocol (114 timepoints). Normalized thalamic volumes were the response variable in multivariate linear mixed effects models to compare rates of thalamic volume loss between groups. RESULTS: In univariate analyses, there was no significant change in thalamic volume over time in HC (beta=0.0002, p=0.68), whereas in all MS subjects, significant thalamic volume loss was seen (beta=-0.00332, p<0.0001). RR showed a faster rate of thalamic volume loss compared with CIS (beta=-0.0011, p=0.03). In a multivariate model adjusted for age, gender, disease duration, DMT use, and baseline EDSS, RR atrophied faster than CIS (beta=-0.002, p=0.003). Higher baseline lesion volume (beta=-0.00043, p<0.001) and increased number of new T2 lesions over time (beta=-0.0003, p<0.001) were both significantly associated with a faster rate of thalamic volume loss. CONCLUSIONS: In MS, thalamic volume declines over time, differs from HC, and occurs faster in RR compared with CIS. Increased white matter lesions were the most significant predictors of faster decline. Thalamic atrophy is a promising MRI metric associated with MS neurodegenerative features. Supported by:NINDS/R01-NS062885;Race to Erase MS. Disclosure: Dr. Azevedo has received personal compensation for activities with Genzyme as an advisory board member. Dr. Khadka has nothing to disclose. Dr. Liu has nothing to disclose. Dr. Pelletier has received personal compensation for activities with Cns Imaging Consultant, LLC as a consultant. Dr. Pelletier9s employer has received research support from Biogen Idec, Genzyme, and Hoffman-LaRoche.
Imaging of the Postoperative Ear and Temporal Bone

This chapter reviews the diagnostic imaging findings related to the procedures involving the ear and temporal bone and relevant devices, including osseointegrated bone conduction hearing implants, auriculectomy. auriculectomy, canaloplasty and meatoplasty, atresiaplasty, myringotomy and tympanostomy tubes, myringoplasty and tympanoplasty, ossicular Interposition, ossicular reconstruction with synthetic prostheses, stapedectomy, stapedotomy, and stapes prostheses, ossicular prosthesis complications, atticotomy, Eustachian tube occlusion procedures. Mastoidectomy and mastoid obliteration, mastoidectomy complications, lateral temporal bone resection, cochlear implants, cochlear implant complications, auditory brainstem implants, repair of perilymphatic fistula, endolymphatic sac decompression and shunting, labyrinthectomy, vestibular nerve sectioning, superior semicircular canal dehiscence repair, and tube drainage of petrous apex cholesterol granuloma.
Chapter 4 – Theories Behind the Chi Plot

The chapter presents a historical background of the theories behind the chi plot. The chapter discusses the chi plot as an excellent fit to adsorption data. The chapter makes use of two derivations, along with their detailed analysis, to explain the chi plot: the disjoining potential theory and the quantum mechanical derivation or chi theory. There is a definite relationship between the disjoining pressure theory of adsorption and the chi theory. The classical derivation or the autoshielding physisorption (ASP) theory is very similar to the quantum mechanical derivation. The chapter discusses the quantum mechanical derivation of the simple chi equation. The chapter also focuses on simultaneous physisorption and chemisorption. The chapter discusses heterogeneous surfaces, heats of adsorption, adsorption of more than one adsorbate, depth profiles and chi theory, and the thermodynamics of spreading pressure.
The Constitutionalization of Democratic Politics - The Supreme Court, 2003 Term

Around the world, courts in the last two decades have increasingly extended constitutional law to oversee the basic structure of democracy itself. This development constitutes a significant transformation in the object of constitutional law - a shift from the conventional individual rights and anti-discrimination focus and toward judicial engagement with the institutions and processes of democratic politics. Whether resolving disputed Presidential elections, evaluating the design of representative institutions, determining the role of political parties, assessing the financing of elections, or even managing the transition from authoritarian to democratic regimes, courts and constitutional law have now become central actors in organizing the way democracy is practiced. The first aim of this Foreword is to make this transformation fully visible. The Foreword focuses primarily on the United States Supreme Court, where these developments are most pronounced. The Foreword then turns to assessing this new frontier of constitutional law; the Foreword argues that, thus far, courts have done both too little and too much in the way they have constitutionalized the essential structures of democracy. Courts have been insufficiently responsive to the tendency of those holding political power to structure the ground rules of democracy to entrench themselves more deeply in power. At the same time, courts have inappropriately constitutionalized, without sufficient justification, the broad rights of politics - to vote, to speak, to associate - in ways that wrongly limit the ability of democracies to experiment with new ways of organizing democratic politics. Given the disaffection with current forms of democracy expressed in many mature democracies today, this judicial tendency to constitutionalize existing democratic arrangements and freeze them in place threatens the ability of democracies to revise themselves. As courts enter this new domain, the Foreword offers a theoretical and doctrinal framework that defines the role constitutional law ought to play - more expansive in some contexts, less expansive in others - in overseeing the structure of democracy. The Foreword then applies this framework to a number of specific issues: partisan gerrymandering; the representation of diverse groups in political bodies; the legal regulation of political parties; the role of independent bodies to oversee election practices; and campaign financing.
Comparing Extreme Programming to Traditional Development for Student Projects: A Case Study

We conducted an experiment attempting to compare XP with a traditional approach to student software engineering projects. We tasked two groups of student teams with producing a simple room reservation system, one group following a traditional development process, the other using XP. We observed little actual difference between the products delivered by either process. However, in our opinion this is due to certain deficiencies in the way XP was realized in this instance, rather than fundamental flaws in the process itself.
Somatosensation and Maternal Care in Norway Rats

Publisher Summary Although virgin females and males may be induced to display aspects of maternal behavior in Norway rats, only females of this species provide parental care in nature and the full repertoire requires that maternal behavior be integrated with the physiology of pregnancy, parturition, and lactation. This chapter focuses on the maternal behavior of postpartum rats. It gives an overview of somatosensation and maternal behavior: the major components of maternal care in rats; the neurobiology of the somatosensory system; the relationships between somatosensory reflexes, behavioral sequences, and motivated behavior; research strategies; and the role of physical interaction with pups on maternal behavior in rats. The chapter focuses on analysis of trigeminal and ventral trunk somatosensory contributions to the postpartum display of nurturant activities toward young and defense of the young. It concludes with discussions of neurobiological consequences and implications of the findings on somatosensory regulation of maternal behavior to date, including cortical plasticity, gene activation, and neural circuits.
Design aspects of long range supersonic LFC airplanes with highly swept wings

Studies on supersonic long-range LFC (laminar flow control) aircraft were performed with the aim of maximizing L/D and alleviating sonic boom during supersonic cruise. It is found that configurations with highly swept LFC wings of very high structural aspect ratio, with the sweep increasing toward the wing root and braced externally by wide chord laminarized struts, appear especially promising. In the supersonic cruise design condition the wing upper surface isobars are swept such that the flow in the direction normal to them is transonic with embedded supersonic zones and practically shock-free over most of the span, with M-perpendicular equal to the two-dimensional design values of advanced SC LFC airfoils, e.g., of the X-787 or X-6 type.
Weather of the postsunset equatorial anomaly recorded daily during 2 years near solar maximum

[1] The maximum F layer electron density of the postsunset equatorial anomaly is the location of the most disruptive scintillation to transionospheric L band transmissions when intersected by an equatorial bubble. Because bubble occurrence is essentially random, the anomaly is studied here for evidence of the predictability of the magnitude of its electron density and therefore of the magnitude of scintillation in the event of bubble occurrence. Measurements are by ionospheric sounders in the western American sector daily for 2 years during solar maximum. This first description of the weather of the anomaly for such an extended duration displays also the major climatological dependences on season and on solar flux, both of which reflect the dependence on the maximum prereversal E × B drift velocity. The most significant finding is that the anomaly electron density varies at intervals of a few days continuously throughout the entire 2 years. Within these intervals, maximum-to-minimum ratios are from 2 to ∼7 within overall magnitudes from 1 to ∼7 × 106 el/cm3. Although otherwise seemingly random, two extraordinary phenomena are evident. The first consists of extremely high magnitudes of electron density that recur for three solar rotations, the latitudinal profiles of which extend to midlatitudes and which are observed also in eastern Asia. The second, quasiperiodic variations of ∼3 days, appear nearly continuously also through three solar rotations. Evidence that both result from variations of the maximum prereversal E × B drift velocity indicates the presence of two contrasting mechanisms affecting drift velocity. The high magnitudes have not been observed before, but the quasiperiodic variations are similar to those observed in the daytime anomaly, where they are attributed to oscillations in the neutral mesosphere. Whatever the mechanism, recurrence of the magnitude of the anomaly indicates the possibility that it may be predicted, and therefore conditions may be predicted under which scintillation can occur.
Orthogonal decision trees for resource-constrained physiological data stream monitoring using mobile devices

This paper considers the problem of monitoring physiological data streams obtained from resource-constrained wearable sensing devices for pervasive health-care management. It considers Orthogonal decision trees (ODTs) that offer an effective way to construct a redundancy-free, accurate, and meaningful representation of large decision-tree-ensembles often created by popular techniques such as Bagging, Boosting, Random Forests and many distributed and data stream mining algorithms. ODTs are functionally orthogonal to each other and they correspond to the principal components of the underlying function space. This paper offers experimental results to document the performance of ODTs on grounds of accuracy, model complexity, and resource consumption.
Optimizing an Internal Airway Percussion Device for Facilitating Exhalate Diagnostics of the Human Respiratory System

Abstract Purpose: There is an urgent need for simple, inexpensive, noninvasive, and repeatable technique for the diagnosis of pulmonary diseases. Bronchoalveolar lavage, which is the gold standard diagnostic method for pulmonary diseases, does not meet any of these criteria. This study seeks to develop and optimize a novel technique of Internal Airway Percussion (IAP) to facilitate the collection and characterization of human respiratory system exhalates. Methods: The IAP device transmits sound waves into the respiratory tract, thereby increasing the release of aerosolized particles within exhaled breath by vibrating both lungs. Nine combinations of sound wave frequencies and amplitudes were studied to determine optimal frequency and amplitude combination for maximum aerosol particle gain in healthy human subjects. Results: Square-shaped sound waves generated at 15 Hz and 3 cm H2O resulted in 15 times greater total mass of collected particles in the first 2 min of sampling, and 1.2 to 1.5 times increase i...
Improving Statistical Efficiency and Testing Robustness of Conjoint Marginal Valuations

We investigate the effect of panelestimators and sample weighting to improve efficiency of coefficient estimates and confidence intervals on marginal values. Panel estimators are appropriate because most conjoint studies have respondents rate multiple product profiles. Using a random effects ordered probit model increases significance levels on two forest health attribute coefficients and results in substantial tightening of confidence intervals on marginal values. To mitigate the effects of low response rate, we weight the returned surveys using Census data to match the sample to the population. Two of the four marginal values from this weighted ordered probit model are substantially different. Copyright 2001, Oxford University Press.
Surgical management of cervical spinal metastasis: anterior reconstruction and stabilization techniques

Metastatic spinal tumors are the most common malignant lesions of the spine. The vertebral column is the most common site of bony metastasis. Nearly 5% to 10% of patients with systemic cancer develop spinal metastases [1,2]. The cervical spine is the least frequently involved by spinal metastases (10%), followed by the lumbar spine (20%) and the thoracic spine (70%) [3]. Breast, lung, prostate, and renal cell carcinomas are the tumors that most frequently metastasize to the spine. Myeloma, lymphoma, and gastrointestinal carcinoma can also invade the vertebral column [1,4–6]. Although the most common symptom is neck pain (90%), more than 50% of patients can present with severe deficits, including acute weakness that evolves quickly to quadriplegia. Mechanical pain secondary to instability can be severe enough that basic activities like walking can become nearly impossible. Significant bone destruction can progress to fracture, instability, deformity, and neurologic compromise. Failure of a vertebral body to support a segment of the spinal column requires effective reconstruction and stabilization. Because most metastatic lesions originate in the vertebral body, an anterior cervical corpectomy offers the most direct approach for tumor excision, neurologic decompression, and effective reconstruction of the weight-bearing vertebral column [7]. This approach is especially appropriate in patients with significant vertebral body destruction resulting in neck pain or symptomatic spinal cord compression. When choosing spinal reconstructive materials and techniques, multiple biomechanical factors must be considered to achieve anatomic restoration of sagittal and coronal plane deformity and physiologic load bearing. Stabilization and reconstruction of the cervical spine after corpectomy can be performed technically in several different ways, each with advantages and disadvantages [7–21]. Generally, the vertebral body defect is reconstructed with bone autograft or allograft, polymethylmethacrylate (PMMA), silastic tubes, titanium interbody spacers and cages, or a combination of the above. Stabilization is then achieved with anterior instrumentation, usually anterior cervical plate fixation, to prevent distraction failure and to provide increased rigidity. Additionally, posterior instrumentation with or without bone grafting may be necessary to supplement the anterior construct. This review discusses the various techniques of anterior vertebral body reconstruction after corpectomy for metastatic tumors of the subaxial cervical spine.
Mesoscale Response to a Meandering Surface Temperature Interface

Abstract Mesoscale variation of the boundary-layer (BL) front produced by a surface temperature interface depends upon the scale of meander along that interface. For a relatively large-scale meander, the circulations are quasi two-dimensional relative to the local interface boundary, and a meander signature appears in the BL structure. For a relatively small-scale meander, alongfront blending eliminates organization about individual meanders to produce a quasi two-dimensional circulation and gradients oriented perpendicular to the mean front. The fundamental atmospheric scale controlling this transition is the mesoscale deformation radius, which depends upon the warm-side BL depth. With strong large-scale geostrophic forcing, however, the resulting alongfront advection length scale increases the meander size required to approach the large-scale limit. Large-scale meanders typically create two local maxima of vertical velocity, whereas small-scale meanders develop a single maximum on the warm side of the f...
Multiple signals underlie the axotomy-induced up-regulation of c-JUN in adult sensory neurons

We examined the axotomy-induced expression of the immediate-early gene (proto-oncogene) c-jun in the Ola mouse mutant (which exhibits a dramatic delay in Wallerian degeneration) using immunocytochemistry to c-JUN (the protein product of the protooncogene c-jun). c-JUN-like protein immunoreactivity was present in a similar proportion (ca. 60%) of L4 dorsal root ganglion (DRG) neuronal cell bodies from normal (C57/6J/BL) and Ola mice at 1 week following a sciatic nerve crush (axotomy). In normal mice, the intensity and extent of staining declined at 3 weeks, correlating with regeneration. In contrast, Ola mice exhibited a marked reduction (by 77%) in the extent of staining at 2 weeks. At 3 weeks (coinciding to the onset of extensive axonal degeneration in this mutant), staining levels were increased to 1 week levels. Taken together, these findings suggest that multiple signals (both independent and dependent on axonal degeneration) regulate c-jun expression in DRG neuronal cell bodies.
Syringomyelia with quadriparesis in CSF shunt malfunction: a case illustration.

Background Shunt malfunction typically presents with headaches, vomiting, and impaired consciousness. Paraparesis has been rarely reported as the initial manifestation of valve dysfunction.
The effects of thyrotropin-releasing hormone on the central nervous system responses to chronic morphine administration

The effects of thyrotropin-releasing hormone (TRH) on abrupt and naloxone-precipitated abstinece symptoms were determined in male Swiss-Webster mice rendered dependent on morphine by SC implantation of morphine pellets. Intracerebral (IC) administration of TRH inhibited the hypothermic response observed during abrupt (removal of morphine pellets) and naloxone (0.1 mg/kg SC) precipitated withdrawal. IC injection of TRH also inhibited the naloxoneprecipitated withdrawal jumping response as evidenced by increases in the dose of naloxone required to elicit the response. The effects of TRH on the development of morphine dependence were also investigated. A single SC injection of TRH (4–16 mg/kg) did not modify development of morphine dependence. Administration of TRH prior to and during morphine pellet implantation inhibited the development of dependence as evidenced by inhibition in the development of abrupt and naloxone-induced withdrawal hypothermia. Even though the hypothermic response was blocked, multiple SC administration of TRH failed to modify naloxone-induced stereotyped jumping response. These studies indicate that TRH administration can modify central nervous system responses to chronic morphine treatment and that separate sites may initiate withdrawal jumping behavior and affect temperature regulation during abrupt and antagonist-induced abstinence.
A comparison of three assignment techniques for metal-ligand stretching bands—a low-frequency infrared study of some transition metal bis,- tris- and tetrakis-tropolonato complexes

Abstract The low-frequency infrared spectra (600-150 cm−1) of several bis- and tris- transition metal tropolonates were measured and the metal-oxygen stretching bands assigned based on the metal-isotope substitution method. Since other assignment methods for these complexes have placed the metal-oxygen stretching bands more than 300 cm−1 higher, the differences were discussed. Eight-coordinate tropolonato complexes were also investigated in the far-infrared region and MO stretching assignments for these complexes presented.
Radiation, Conduction, and Convection From a Sphere in an Absorbing, Emitting, Gray Medium

Combined mode heat transfer is solved for an emitting, reflecting sphere in low Peclet number motion through a gray, nonscattering, absorbing, emitting, and conducting infinite medium. The coupled formulation of the energy and radiative transfer equations is solved numerically. The radiative transfer equation is expressed in a unique spatial-directional coordinate system, whose object is to exploit the axisymmetry of the problem. The radiation intensity field is solved using the discrete ordinates method. Results are presented in terms of the Planck and Peclet numbers, and serve as a combined radiation/convection analog to the well-known Nusselt number results for a radiatively nonparticipating medium.
Phosphine functionalized single-walled carbon nanotubes

Ultrashort single-walled carbon nanotubes (US-SWNTs) were covalently derivatized with triaryl and trialkyl phosphines. The resulting US-SWNT-phosphine oxide derivatives were then reduced to the US-SWNT-phosphines. In addition, a triarylphosphine sulfide derivative was prepared. The products were characterized by 31P and 13C MAS NMR. The phosphorus NMR indicates a poor correlation between the chemical shifts of molecular phosphines and the chemical shifts of the related US-SWNT-P derivatives.
Randomized minimum spanning tree algorithms using exponentially fewer random bits

For many fundamental problems there exist randomized algorithms that are asymptotically optimal and are superior to the best-known deterministic algorithm. Among these are the minimum spanning tree (MST) problem, the MST sensitivity analysis problem, the parallel connected components and parallel minimum spanning tree problems, and the local sorting and set maxima problems. (For the first two problems there are provably optimal deterministic algorithms with unknown, and possibly superlinear, running times.) One downside of the randomized methods for solving these problems is that they use a number of random bits linear in the size of input. In this article we develop some general methods for reducing exponentially the consumption of random bits in comparison-based algorithms. In some cases we are able to reduce the number of random bits from linear to nearly constant, without affecting the expected running time.Most of our results are obtained by adjusting or reorganizing existing randomized algorithms to work well with a pairwise or O(1)-wise independent sampler. The prominent exception, and the main focus of this article, is a linear-time randomized minimum spanning tree algorithm that is not derived from the well-known Karger-Klein-Tarjan algorithm. In many ways it resembles more closely the deterministic minimum spanning tree algorithms based on soft heaps. Further, using our algorithm as a guide, we present a unified view of the existing “nongreedy” minimum spanning tree algorithms. Concepts from the Karger-Klein-Tarjan algorithm, such as F-lightness, MST verification, and sampled graphs, are related to the concepts of edge corruption, subgraph contractibility, and soft heaps, which are the basis of the deterministic MST algorithms of Chazelle and Pettie-Ramachandran.
Cost reduction, entry, and the interdependence of market structure and economic growth

Abstract I study the joint determination of market structure and growth in an oligopolistic economy. Firms run in-house R&D programs to produce over time a continuous flow of cost-reducing innovations. In symmetric equilibrium, the relation between market structure and growth has two aspects. First, a larger number of firms induces fragmentation of the market and dispersion of R&D resources. This prevents exploitation of scale economies internal to the firm and slows down growth. Second, the number of firms changes with market and technology conditions and is endogenous. In particular, R&D spending is a fixed cost and there is a negative feed-back of the rate of growth on the number of firms. The explicit consideration of the interdependence of market structure and growth identifies a fundamental trade-off between growth and variety that produces interesting results. For example, the scale effect is bounded from above and converges to zero when the number of firms is large. Moreover, the market grows too little and supplies too much variety. The inefficiency is not due to technological externalities but to oligopolistic pricing and the interaction between R&D and entry decisions.
Relationship of two human tRNA synthetases used in cell signaling

Human tyrosyl-tRNA synthetase (TyrRS) and tryptophanyl-tRNA synthetase (TrpRS) are closely related, dual function enzymes that act in protein biosynthesis and angiogenesis. The recent crystallographic structures of these two enzymes show that they adopt remarkably similar three-dimensional (3D) architectures, being more like each other than like their respective prokaryotic orthologs. In particular, adaptations to the anticodon recognition domain of TyrRS cause distinct appended domains in TyrRS and TrpRS to occupy the same 3D space and thus to mask a common surface on each synthetase. Thought to be important for cell-signaling activity, this surface is made accessible by proteolytic cleavage, thereby activating the cell-signaling function of these enzymes.
Daunorubicin and adriamycin facilitate actinomycin D binding to poly(dA–dT)·poly(dA–dT)

ACTINOMYCIN D (Fig. 1a) binds to DNA by intercalation of the phenoxazone ring between adjacent base pairs of the double helix1–4. There is a general requirement for a guanine base at the actinomycin D binding site on DNA, as illustrated by the observation that actinomycin D does not intercalate into double-stranded (ds) poly(dA-dT)·poly(dA-dT) (refs 1–4). Daunorubicin, adriamycin (Fig. 1b) and ethidium bromide (Fig. 1c) also intercalate into dsDNA, but in contrast to actinomycin D, these drugs do not show any requirement for a particular base at the intercalation site5,6. Both actinomycin D and ethidium bromide do, however, show definite preferences for binding to certain sequences of nucleic acid bases at the intercalation site7–11. In this report we show that daunorubicin and adriamycin facilitate strong binding of actinomycin D to poly(dA-dT)·poly(dA-dT) and we discuss the implications of this new observation.
Changes in cytosolic free calcium with 1,2,3,4-tetrahydro-5-aminoacridine, 4-aminopyridine and 3,4-diaminopyridine.

The effects of 1,2,3,4-tetrahydro-5-aminoacridine (THA), 4-aminopyridine (4-AP) and 3,4-diaminopyridine (3,4-DAP) on cytosolic free calcium (Ca2+i) were determined. Both 4-AP and THA have been used to treat Alzheimer's disease. THA is a structural analog of the aminopyridines, which alter calcium homeostasis in nerve terminals. The structural similarities between these compounds suggest a common mechanism of action. The aminopyridines raised Ca2+i concentrations in non-depolarized synaptosomes, whereas THA had no effect. Neither the aminopyridines nor THA had any effect on Ca2+i concentrations in potassium-depolarized synaptosomes. These results suggest that the beneficial effects of THA may be mediated by other mechanisms (i.e. neurotransmitter degradative enzyme inhibition), whereas those of 4-AP and 3,4-DAP may be due, at least in part, to their elevation of Ca2+i, which may enhance neurotransmitter release or other calcium-dependent processes.
Structural Vibration Control Via Electrorheological-Fluid-Based Actuators With Adaptive Viscous And Frictional Damping

Abstract It has been recognized that the semi-active control concept is promising for vibration suppression of flexible structures and that the electrorheological (ER) fluid-based device is a good candidate for such applications. In this research, a new control law is developed to maximize the damping effect of ER dampers for structural vibration suppression under actuator constraints and viscous-frictional-combined damping. Numerical simulations and experimental work are carried out to evaluate the semi-active concept. It is illustrated that the performance of the semi-active system is superior to those of the critical damping and maximum damping variety. It is also concluded that the actuator frictional effect is significant, and should be considered in the controller design process.
Early clinical results with a multiple synchronized pulse 1064 NM laser for leg telangiectasias and reticular veins.

Background The 1064 nm wavelength penetrates tissue and blood vessels with little absorption by melanin. Objective To perform a study examining the effects of 1064 nm laser used in pulses from 4 msec to 16 msec on leg telangiectasias ranging in size from 0.5 to 3 mm. Method. In this initial trial, 50 sites on 30 patients were enrolled and treated with a multiple synchronized pulse laser at 1064 nm. The primary parameter utilized was a single 10–16 msec pulse. Improvement was judged by comparison of digital images at 1 month, 2 months, and 3 months posttreatment. Improvement was judged, based on size and number of vessels remaining. Side effects were noted as present or absent at each visit. Results Immediate contraction or darkening followed by urtication and visible total vessel closure as indicated by absence of blanching and visual elimination of the vessel border occurred in most of the treated sites. Two 3 mm diameter vessels were confirmed to be closed without flow by Duplex ultrasound visualization, using a 10 MHz transducer. Bruising from vessel rupture was seen in approximately 50% of the cases. No epidermal injury was noted in any sites, even in Fitzpatrick skin Types IV. At 3 months follow-up, 75% improvement was noted at treatment sites. Conclusions. Initial clinical results with a new multiple synchronized pulsed 1064 nm laser indicate that this longer wavelength supplied at pulses of up to 16 msec appears to be a valuable modality for immediate closure and subsequent elimination of leg ectatic veins. Epidermal injury is unlikely, as the near infrared wavelength has minimal interaction with melanin.
2 MV Injector as the Elise Front-End and as an Experimental Facility

Abstract We report on progress in the preparation of the 2 MV injector at LBNL as the front end of Elise and as a multipurpose experimental facility for heavy ion fusion beam dynamics studies. Recent advances in the performance and understanding of the injector are described, and some of the ongoing experimental activities are summarized.
Familiarity With School English in African American Children and Its Relation to Early Reading Achievement

For children whose everyday speech differs greatly from the School English (SE) they encounter in academic materials and settings, it was hypothesized that greater familiarity with SE would be associated with more successful early reading acquisition. Sentence imitation and reading skills of 217 urban African American students in kindergarten through second grade (ages 5 to 8 years) were assessed. Children in each grade varied widely in the extent to which their imitations of SE sentences included phonological and grammatical forms that are acceptable in African American Vernacular English but not in SE. Higher familiarity with SE (reproducing SE features more often when imitating) was associated with better reading achievement, and these relationships were independent of memory ability.
Sarason's context of productive learning: Towards the development of a measure to assess teacher goals

The authors developed a 40-item teacher-completed measure designed to assess educational goals, including Sarason's concept of a context of productive learning (COPL). Elementary-level teachers from schools across a range of sociodemographic contexts rated the importance of each of several goals. Factor analysis identified four factors: Traditional Learning, Context of Productive Learning (COPL), Teacher Control, and Meeting Requirements. Teachers who reported high levels of enjoyment of teaching and those teaching in the lower grades had higher scores on the COPL factor than their opposites. Also, teachers who reported that their teaching objectives had been shaped more by personal values and experiences than by training and supervision had higher COPL factor scores. Needed future steps include refinement of its item composition, replication with a larger sample, and exploration of its relationship to (a) actual teacher behaviors in the classroom and (b) pertinent child educational and behavioral outcomes. © 2001 John Wiley & Sons, Inc.
Oncogenic pathways implicated in ovarian epithelial cancer.

Abstract Characterization of intracellular signaling pathways should lead to a better understanding of ovarian epithelial carcinogenesis and provide an opportunity to interfere with signal transduction targets involved in ovarian tumor cell growth, survival, and progression. Challenges toward such an effort are significant because many of these signals are part of cascades within an intricate and likely redundant intracellular signaling network (Fig.1). For instance, a given signal may activate a dual intracellular pathway (ie, MEK1-MAPK and PI3K/Akt required for fibronectin-dependent activation of matrix metalloproteinase 9). A single pathway also may transduce more than one biologic or oncogenic signal (ie, PI3K signaling in epithelial and endothelial cell growth and sprouting of neovessels). Despite these challenges, evidence for therapeutic targeting of signal transduction pathways is accumulating in human cancer. For instance, the EGF-specific tyrosine kinase inhibitor ZD 1839 (Iressa) may have a beneficial therapeutic effect on ovarian epithelial cancer. Therapy of this cancer may include inhibitors of PI kinase (quercetin), ezrin and PIP kinase (genistein). The G protein-coupled family of receptors, including LPA, also is an attractive target to drugs, although their frequent pleiotropic functions may be at times toxic and lack specificity. Because of the lack of notable toxicity, PI3K/Akt pathway inhibitors such as FTIs are a promising targeted therapy of ovarian epithelial cancer. Increasing insight into the oncogenic pathways involved in ovarian epithelial cancer also is helping clinicians to understand better the phenomenon of chemoresistance in this malignancy. Oncogenic activation of gamma-synuclein promotes cell survival and provides resistance to paclitaxel, but such a resistance is partially overcome by an MEK inhibitor that suppresses ERK activity. Ovarian epithelial cancer is a complex group of neoplasms with an overall poor prognosis. Comprehension of this cancer pathobiology suffers because of an incomplete understanding of precursor lesions and the absence of an orthotopic animal model until very recently. It can be predicted with confidence, however, that the discovery of potent inhibitors of signal transduction and the development of discovery tools, such as proteomics and metabolomics, may change the way by which clinicians may now address basic biomedical questions in this insidious and lethal disease.
Feature extraction from ladar data using modified GPCA

In this paper we present a method for extracting feature information from ladar data presented in the form of a spatial point cloud. The method exploits a modified version of Generalized Principal Component Analysis (GPCA) to extract planar, or even non-linear, surface elements from this sort of data. The essential difficulty is that, depending on the aspect of the object, certain surfaces will be minimally exposed. As a result we cannot say in advance how many surfaces we are looking for, and we cannot reliably detect surfaces that are hit by only a few of the points in the cloud. An additional difficulty occurs when reconstructing the surface normal at points near where two surfaces join. The algorithm handles both issues and captures enough essential surface features to allow accurate alignment to say a CAD model for detailed recognition. One can also use the extracted planar facets as a kind of partial bounding polyhedron (modified partial bounding box) as input to an initial identification algorithm that works off of the invariants of the planar arrangement.
Primary cultures of adult mouse and rat hepatocytes for studying the metabolism of foreign chemicals

Abstract A primary hepatocyte culture was developed as a model system to investigate the metabolism of foreign chemicals. Hepatocytes were prepared from adult male Charles River CD-1 mice and adult male Sprague-Dawley rats by in situ pre-perfusion of the liver with ethyleneglycol-bis-(β-amino-ethyl ether) N , N ′-tetra-acetic acid (EGTA) followed by perfusion with calcium and collagenase. The digested liver was dispersed, and hepatocytes were isolated by filtration and differential centrifugation yielding 10 8 hepatocytes per mouse liver and 5 × 10 8 hepatocytes per rat liver. More than 90 per cent of the hepatocytes excluded trypan blue. Hepatocytes were prepared aseptically, plated on tissue culture dishes coated with rodent tail collagen (2.5 × 10 6 cells/60 mm dish), and cultured in serum-free modified Waymouth's medium. Within 4hr the hepatocytes attached to the collagen, and by 24 hr they had flattened and formed a monolayer. A non-metabolizable alanine analog, α-aminoisobutyric acid, accumulated in mouse hepatocytes with peak incorporation occurring at 24 hr. Cultured mouse and rat hepatocytes were able to N -demethylate para-chloro- N -methylaniline (PCMA). An NADPH-generating system stimulated N -demethylation 2.75-fold in freshly isolated mouse hepatocytes, but did not stimulate metabolism in cultured mouse hepatocytes. SKF 525-A inhibited PCMA N -demethylation in cultured mouse hepatocytes with an I 50 of 3.75 × 10 −5 M. Hormonal supplementation of the culture medium stimulated PCMA metabolism measured in 24- and 48-hr cultures. These studies demonstrate the utility of rodent hepatocyte cultures as models of hepatic metabolism of foreign chemicals.
The formation of asymmetric polystyrene/saponite composite nanoparticles via miniemulsion polymerization

The synthesis of asymmetric spherical nanoparticles has attracted great interest because their anisotropic structure can be used as unique building blocks for constructing advanced materials. In this article, we report the formation of hemispherical or truncated polystyrene/nanosaponite composite particles via one-pot miniemulsion polymerization. It was found that the morphology of final composite latex particles strongly depends on the size of the nanoclay and its surface properties. Hemisphere or truncated sphere is the dominant morphology if the size of the nanoclay is larger than 100 nm. With the increase of the nanoclay content (up to 30 wt %), the fraction of hemispherical or truncated polystyrene/nanosaponite composite latex particles increased accordingly. The formation of hemispherical particles is possibly attributed to either the asymmetric growth of polymer chains on one side of the hydrophobically modified clay or the mechanical peeling-off of large spherical particles between polymer and saponite. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Wavefield Extrapolation In the Wavelet Domain With Application to Poststack Migration

In the spatial wavelet domain, wavefields are represented by linear summation of scaled and translated wavelets. Because wavelets are localized in both the space and wavenumber domains, the representation of wavefield in wavelet bases is compact, so less computation is needed for wavefield extrapolation. A wavelet transformation is performed over each of the spatial coordinates of the scalar wave equation. The wavefield extrapolation is performed in the spatial wavelet domain without transforming back into the space domain at each time step. The transformed wavelet coefficients are extrapolated, rather than the wavefield itself. This transformed equation is solved directly with a finite-difference scheme and is illustrated by application to zero-offset reverse-time migration.