cssi/SciSciGPT-SciSciNet huggingface dataset:
Adaptive test assembly with a mix of set-based and discrete items

Adaptive test assembly entails an added layer of complexity when the test is designed with both discrete and set-based items. Among the challenges is how to interweave discrete and set-based items optimally within each adaptive test. The task is further complicated by the requirements for exposure control of both items and item sets, adjusting adaptivity while administering items within item sets, and maintaining optimality given additional complexity. The present study investigates practical solutions for addressing the challenges and proposes new item selection methods within the optimal test design framework.
Targeting social safety net programs on human capabilities

Abstract Conventional approaches to targeting social safety net programs select beneficiaries on the basis of income or expenditure levels. We argue that these approaches neglect human diversity and agency, which can lead to counterintuitive targeting outcomes and thus a misallocation of benefits. In light of these issues, we develop an alternative method for targeting that is based on the capabilities approach, which we claim provides a more rigorous normative framework for targeting that respects both human diversity and agency. In particular, we adapt Bayesian additive regression trees for the estimation of human capabilities and demonstrate how the resulting estimates can be used to target social safety net programs. We examine the targeting implications of our method through a variety of simulation exercises and also with real data from a field experiment conducted in Indonesia. Relative to more traditional approaches – including not only the full and proxy means test, but also community-based targeting – we find that our method identifies a fundamentally different and arguably more disadvantaged group of beneficiaries.
When Moral Arguments Become Intractable

Cassell and Rich's argument that “existential suffering” should merit terminal sedation (TS) in end-of-life (EOL) scenarios just like refractory, physical, and psychiatric morbidity strikes me as an appealing, patient-centered approach. The idea that I can exert considerable control over my dying when the Grim Reaper pays me his inevitable visit is at least somewhat comforting. Similarly, their argument that existential vs physical EOL suffering is a distinction without a real difference has much to commend it. Nevertheless and despite all its rhetoric, the American Medical Association (AMA) is the country's most prominent advocacy group for physicians, not health care consumers; and what might be in the …
Uranium-Series Constraints on Subrepository Water Flow at Yucca Mountain, Nevada

Mineral abundances and whole-rock chemical and uranium-series isotopic compositions were measured in unfractured and rubble core samples from borehole USWSD-9 in the same layers of variably zeolitized tuffs that underlie the proposed nuclear waste repository at Yucca Mountain, Nevada. Uranium concentrations and isotopic compositions also were measured in pore water from core samples from the same rock units and rock leachates representing loosely bound U adsorbed on mineral surfaces or contained in readily soluble secondary minerals. The chemical and isotopic data were used to evaluate differences in water-rock interaction between fractured and unfractured rock and between fracture surfaces and rock matrix. Samples of unfractured and rubble fragments (about 1 centimeter) core and material from fracture surfaces show similar amounts of uranium-series disequilibrium, recording a complex history of sorption and loss of uranium over the past 1 million years. The data indicate that fractures in zeolitized tuffs may not have had greater amounts of water-rock interaction than the rock matrix. The data also show that rock matrix from subrepository units is capable of scavenging uranium with elevated uranium-234/uranium-238 from percolating water and that retardation of radionuclides and dose reduction may be greater than currently credited to this aspect of the natural barrier. Uranium concentrations of pore water and the rock leachates are used to estimate long-term in situ uranium partition coefficient values greater than 7 milliliters per gram.
Toward A Linear Control Design For Power Systems

This paper details the design of local linear controllers to achieve transient stability of power systems. The design method is based on Lyapunov direct method and does not require linearization of nonlinear transformation. The resulting linear control law can stabilise a power system without exact knowledge of its parameters except the steady state of the power system. The steday state in normally the desired trajectory and is in fact the solution of the power flow equations of the power system. The effect that the obtained steady state differs from the actual desired trajectory is also considered.
Saturated film boiling of nitrogen from atmospheric to the critical pressure

Film boiling is a dominant mechanism for heat transfer in many cryogenic systems because of the relatively low saturation temperature of cryogenic fluids. Film boiling is also important in boiler operation, spray cooling of nozzles, and quenching.
IMAGENET: a high speed local area network

Developments in image and signal processing have generated the need for a distribution system capable of transferring extremely large files while maintaining acceptable delays for real-time control packets. To fill this need, IMAGENET has been developed, a local area network (LAN) capable of transferring large data packets, as well as small real-time command messages, over a STAR-configured fiber-optic network. The authors describe the IMAGENET architecture, discuss its advantages over other LAN architectures, and utilize an M/G/1 priority queueing model to demonstrate its performance characteristics. >
Effects on behavior state of prone versus seated positioning for infants with gastroesophageal reflux.

To evaluate the effect of positioning on behavior in infants with gastroesophageal reflux, 48 infants younger than 6 months of age (range 1.5 to 28 weeks, median 13.5) with reflux were positioned continuously prone (24 infants) or seated (24 infants) during a 120-minute postprandial period, during which behavior was monitored continuously. The prone position was associated with more sleep time, 83.5 (16 to 113) vs 43 (0 to 117) minutes, P = .01. This increase in sleep time in the prone position could be largely accounted for by a tendency toward a decrease in crying time, 19 (0 to 82) vs 38.5 (0 to 91) minutes, P = .07, which is expressed further by the significantly smaller number of prone than seated infants who cried longer than 30 minutes, P = .02. A parallel reduction in noncrying awake time in the prone vs the seated position was not significant: 15 (0-51) vs 31 (3 to 84) minutes, P = .13.
Comparison of semi-quantitative and formal metrics for multi-zone airflow model quality assessment

Multi-zone air and contaminant flow models of actual buildings have many practical and scientific uses, such as estimating air leakage rates, predicting exposure to contaminants, and studying ventilation controls to name only a few. A multi-zone model is an abstraction that may predict performance that differs from observed behavior of an actual building due to inaccuracy or uncertainty in inputs, (e.g., envelope leakiness, and mechanical ventilation rates) or to non-uniform airflow and contaminant distributions in spaces. To ensure close agreement between model and actual building, a procedure for “calibrating” (equivalently, “tuning”) the model by adjusting model parameters based on measurements in the actual building is needed. A method for calibrating multi-zone airflow models using a semi-empirical metric (defined as the fraction of correct interzonal airflow directions) has been subjected to a number of field tests with encouraging results, i.e., the metric value increased as a result of calibration...
Interpretation of fluorescence correlation spectroscopy and photobleaching recovery in terms of molecular interactions.

Publisher Summary Fluorescence photobleaching recovery (FPR) and fluorescence correlation spectroscopy (FCS) are two closely related methods for measuring the rates of diffusion, flow, and chemical reactions. Although the two methods share similar theoretical bases and experimental methods, they differ in that FPR measures the dissipation of a macroscopic concentration gradient generated by pulse photolysis, whereas FCS measures the average time course of spontaneous microscopic concentration fluctuations that are constantly occurring even though the system is in equilibrium. Both FPR and FCS are based on the measurements of the fluorescence emitted from a small open observation subregion of the sample. The measured intensity varies with the number of fluorescent molecules and so increases or decreases as these molecules enter or leave the subregion. Hence, knowing the size of the observation region, diffusion coefficients and drift or flow velocities can be determined from the measurements of the rate of change of fluorescence reactants. Hence, FCS and FPR can be used to characterize both transport properties and chemical reaction kinetics. This chapter discusses the conceptual bases, theory, capabilities, and interpretation of these two approaches, emphasizing their application to measure molecular interactions.
A Critical Review of Randomized Field Trials of Case Management for Individuals with Serious and Persistent Mental Illness

Social workers are a dominant presence in public mental health, and many serve as intensive case managers. This critical review of randomized field trials of intensive case management for individuals with serious and persistent mental illness finds only qualified support for the efficacy of intensive case management. This article reviews published trials since the inception of the CSS initiative. Inadequate sample sizes by design and attrition, vaguely delimited conceptual frameworks, and inconclusive analysis strategies are faulted for the inconclusiveness of the research to date. Directions for correcting these weaknesses in case management research and in random trials of social work practice research in general are discussed.
Security Apparatuses in the Arab Spring: A Comparative Analysis of Tunisia and Egypt

The institution of security apparatuses were vital in the recent Arab Spring uprising and this paper examines the structural differences between security forces in Tunisia and Egypt. In Ben Ali’s Tunisia, the security structure was fragmented with the weaker military (which faced no external threats) removed from the patrimonial core, whereas the stronger internal forces were more central to the coercive regime. In Mubarak’s Egypt, the security structure was more centralized, with the strong military placed at the core and with all the auxiliary forces placed within their command. These separate structures resulted into different outcomes: in Tunisia the fragmentation led to more elite defection of security personnel and the transition was able to remove the remnants of the previous regime more efficiently. In Egypt, the centralized structure also led to elite defection but for a different reason: the military essentially filled the void and took the place of the previous regime. This paper is based upon in-country research in Tunisia in the summer of 2011, and examines political transition through an institutionalist lens, advocating the structural importance of security apparatuses during regime change.
Exit the Frog, Enter the Human: Physiology and Experimental Psychology in Nineteenth-Century Astronomy

This paper deals with one of the first attempts to measure simple reactions in humans. The Swiss astronomer Adolph Hirsch investigated personal di!erences in the speed of sensory transmission in order to achieve accuracy in astronomy. His controversial results, however, started an intense debate among both physiologists and astronomers who disagreed on the nature of these di!erences. Were they due to di!erent eyes or brains, or to di!erences in skill and education? Furthermore, they debated how to eliminate them. Some, for example, wanted to eliminate the observer, and prescribed the use of new technologies like the electro-chronograph or photography, while others believed in discipline and education. By debating the nature of these di!erences, astronomers and physiologists sketched both di!erent conceptions of 'man' and di!erent paths to objectivity. These diverse conceptions, moreover, were tied to current nineteenth-century debates, such as the benefits or disadvantages of railroads, telegraphy and the standardization of time and longitudes. By focusing on the debates surrounding the speed of sensory transmission, this paper reevaluates the history of astronomy, physiology and experimental psychology. Furthermore, in investigating astronomy's relation to the human sciences, it uncovers profound connections in the traditionally separate histories of objectivity and the body.
Geotherm: the U.S. geological survey geothermal information system

Abstract GEOTHERM is a comprehensive system of public databases and software used to store, locate, and evaluate information on the geology, geochemistry, and hydrology of geothermal systems. Three main databases address the general characteristics of geothermal wells and fields, and the chemical properties of geothermal fluids; the last database is currently the most active. System tasks are divided into four areas: (1) data acquisition and entry, involving data entry via word processors and magnetic tape; (2) quality assurance, including the criteria and standards handbook and front-end data-screening programs; (3) operation, involving database backups and information extraction; and (4) user assistance, preparation of such items as application programs, and a quarterly newsletter. The principal task of GEOTHERM is to provide information and research support for the conduct of national geothermal-resource assessments. The principal users of GEOTHERM are those involved with the Geothermal Research Program of the U.S. Geological Survey. Information in the system is available to the public on request.
Texture rendering system for architectural design

Abstract Depicting construction materials in colour enhances the realism of synthetic images and provides the architect with a powerful design tool. A computer-aided system for creating textured renderings of architectural designs is presented. This enables the designer to organize libraries of texture samples and details extracted from digital images of colour photographs of actual materials. Furthermore, buildings can be interactively positioned on an optically scanned site background and the textures mapped to simulate any desired view of the building. The system was designed so that it could be used quickly and easily by architects with little computer experience.
The threat of organizational downsizing on the innovative propensity of R&D professionals

Downsizings, re-engineering, and restructuring continue to be strategic initiatives employed by the management of US companies. Although the lay-offs that result from these activities have yielded some short-term benefits for companies, over the long term, the ability of the firm to innovate new products and processes may be compromised. In this article four antecedent variables of individual innovation are identified: a willingness to take risks, a willingness to make suggestions, the degree to which one is motivated by the job, and the degree to which one is motivated by fear. A model is developed and hypotheses proposed to test the effect of the threat of downsizings on these four factors. The results of our study revealed that these threats have a significant effect on all four factors in a direction which is detrimental to the propensity of R&D professionals to be innovative. The article concludes with suggestions for R&D managers in a downsizing environment to foster the innovation process at the individual level.
Olfactory discrimination of squirrel monkey mothers by their infants

Infant squirrel monkeys, 8 to 24 weeks of age, were tested for their ability to discriminate their own mother from another lactating mother by means of olfactory cues, visual cues, or a combination of both. Discrimination by olfactory cues was unequivocal. Addition of static visual cues did not enhance discrimination, and infants showed little evidence of discriminating the mother by means of static visual cues alone. These results suggest that olfaction may be a more significant factor in primate early attachment than has generally been assumed.
A method of basal forebrain anatomical standardization for functional image analysis

Functional as well as structural assessment of the basal forebrain has mostly focused on the dorsal caudate and putamen in axial slices where they are easily outlined or their centers located with stereotaxic methods. The more ventral extent of the basal forebrain, where the irregular form and indistinct boundaries of the nucleus accumbens and substantia innominata are difficult to trace and where the brain's ventral surface may contribute partial volume artifacts to measurement, has been less studied. We present a method based on coronal sections, landmarks placed on clearly visible anchor points, and the computational technique of thin-plate spline warping which allows the alignment of groups of individuals to common coordinates for pixel-by-pixel statistical mapping. The reliability of the landmarks across independent raters yields a median absolute difference of 1.3-1.6 mm. The validity of the method is confirmed by variance maps which reveal significant decreases in variance over spindle and bounding box alignment.
Correcting for miniature eye movements in high resolution scanning laser ophthalmoscopy

The newest generation of confocal scanning laser ophthalmoscopes with adaptive optics correction of ocular aberrations provides retinal images of unprecedented resolution, allowing for real-time imaging of photoreceptors in the living human eye. Natural fixational eye movements made by the subject/patient during recording produce distortions that are unique in each frame. Correction for these distortions is necessary before multiple frames can be added together to achieve noise reduction or to build a mosaic image from different retinal areas. Here we describe the characteristics of fixational eye movements and the distortions they produce during retinal imaging, we show examples of images with particular distortions, and show eye movement records obtained during the correction of these distortions.
Tunneling into a periodically modulated Luttinger liquid

We study the tunneling into the edge of the Luttinger liquid with a periodically modulated concentration of electrons. It is shown that the modulation, by causing a gap in the spectrum of plasmons, leads to an additional anomaly in the density of states at a frequency corresponding to the center of the gap. The shape of the anomaly depends strongly on the {ital phase} of the modulation. The sensitivity to the phase is related to the plasmon mode, localized at the edge, its frequency lying within the gap (analog of the Tamm state for an electron in a periodic potential). {copyright} {ital 1997} {ital The American Physical Society}
A 64K bipolar PROM

A 65,536b bipolar PROM, using a lateral NiCr fuse link on a junction isolated process and 3μ lithography, will be discussed. Consumption is 190mA and typical access time is 45ns.
DEVELOPMENTAL H 3 -NITRENDIPINE BINDING IN IMMATURE SPINAL CORD NEURONS WITH INCIDENTAL TTX DISPLACEMENT

DEVELOPMENTAL H 3 -NITRENDIPINE BINDING IN IMMATURE SPINAL CORD NEURONS WITH INCIDENTAL TTX DISPLACEMENT
Expression analysis of putative stem cell markers in human benign and malignant prostate.

BACKGROUND Stem cells were suggested to be present in human prostate cancer as a small population of distinct cells, which may contribute to carcinogenesis, tumor recurrence, and chemoresistance. To identify potential prostatic stem cells, we analyzed the expression of several potential stem cell markers in benign prostate and prostatic adenocarcinoma. METHODS CD44, CD133, Oct4, SOX2, and EZH2 expression was detected by immunohistochemical (IHC) staining using tissue microarray assays (TMA) composed of benign (non-neoplastic) prostatic tissue, high grade prostatic intraepithelial neoplasia (HGPIN), and prostatic adenocarcinoma. Positive staining was defined as 1+ ( 50%). RESULTS We found CD44 staining in 97% and 72% of benign + HGPIN and malignant lesions, respectively. CD133 staining was detected in a small fraction (4 of 67) of prostate carcinomas. We found that Oct4 nuclear expression was strongly associated with benign lesions and HGPIN but not prostate cancer (P < 0.05). In most cases, nuclear expression of EZH2 and SOX2 was detected in less than 10% of cells in non-neoplastic prostate glands, HGPINs or prostate adenocarcinomas. Moreover, 27 of 33 SOX2 1+ prostate cancers were also EZH2 1+, whereas all 33 of these cases were CD44+. CONCLUSIONS Expression of CD44 and Oct4 identified large populations of benign and malignant cells in the prostate, which did not fit the definition of stem cells as a small fraction of the total cell population. Our results suggest that combined expression of embryonic stem cell markers EZH2 and SOX2 might identify potential cancer stem cells as a minor (<10%) subgroup in CD44+ prostatic adenocarcinoma. Prostate 71: 18–25, 2011. © 2010 Wiley-Liss, Inc.
A combined laparoscopic-endoscopic method of assessment to prevent the complications of short esophagus

As antireflux surgery has been used increasingly for gastroesophageal reflux disease (GERD), a need has arisen for an accurate method to assess esophageal length. There are a number of preoperative tests that can help surgeons to establish the presence of a short esophagus, but intraoperative assessment after esophageal mobilization is the standard method. In this era of laparoscopic surgery, the surgeon mobilizes the esophagus extensively from the abdomen and then determines if mobilization is sufficient. We report an intraoperative technique that combines laparoscopic with endoscopic methods to determine the position of the gastroesophageal junction. Because two physicians are required, there is additional operating room time, resulting in increased costs. However, these costs are offset by the assurance that the complications of the short esophagus can be avoided. With experience, modifications were made, resulting in the technique described herein.
Correction to 'Certifying the reliability of software' (Jan. 1986 3-11)

The authors correct several typographical errors, and misinterpretations in their abovementioned paper (see ibid., vol.SE-12, no.1, p.3-11, Jan. 1986). >
Southeastern Archaic Mounds: Examples of Elaboration in a Temporally Fluctuating Environment?

Mounds dating to the mid-Holocene in the southeastern United States have challenged traditional ideas about conditions under which elaboration tends to occur. A hypothesis of wasteful behavior based on Dunnell's (1989) waste scenario and bet hedging from evolutionary ecology (Seger and Brockmann 1987) may provide a viable account for the selection of elaboration, including early mounds. Some of the variables required to formulate a satisfactory test of this and alternative explanations are examined. Paleoenvironental data suggestive of a temporally variable environment in the Southeast during the mid-Holocene are examined. More detailed flooding histories will be an essential part of future research concerned with testing these types of hypotheses.
Mechanism of MPTP toxicity: more answers, more questions

Abstract Although first synthesized in 1947, the biological effects of MPTP have only recently been recognized. This compound is a highly selective neurotoxin which appears to kill only the dopaminergic cells of the zona compacta of the substantia nigra after systemic administration. Bill Langston describes recent research into its mechanism of toxicity, which apparently depends on its oxidation by monoamine oxidase. The major metabolite, MPP + (1-methyl-4-phenylpyridinium species) may gain entrance to dopaminergic neurons via the dopamine uptake system. However, it is not certain that MPP + is the actual neurotoxin and the mystery surrounding the unique selectivity of the nigrostriatal dopaminergic system remains to be unravelled. MPTP has led to the development of an animal model for Parkinson's disease. Will it also provide clues as to the etiology of this disease?
Fabrication of optical surfaces with low subsurface damage using a float polishing process

The attempt to eliminate subsurface damage in polished materials is a major objective in optical and semiconductor fabrication. The level of subsurface damage in optical components is proportional to the surface scatter and related to the laser damage threshold of the optic. The float polishing process has been shown to produce surfaces with low subsurface damage on ferrite materials. We have ground samples of rough cut Corning 7940 fused silica using synthetic polycrystalline diamond. These samples were then float polished on a precision machine manufactured by Toyoda Machine Works Limited. Our surfaces were characterized using differential phase interference microscopy, total internal reflection microscopy, and scatterometry. We will describe the fabrication process and report the results of the surface and subsurface characterization.
Direct incorporation of octanoate into long-chain fatty acids by soluble enzymes of Mycobacterium tuberculosis.

Abstract The incorporation of acetate into long-chain fatty acids by cell-free extracts of the H37Ra strain of Mycobacterium tuberculosis is markedly stimulated by the presence of other fatty acids; the stimulation is maximal when octanoate is added to the system. A partially-purified enzyme system catalyzes the avidin-insensitive elongation of octanoyl-CoA by acetyl-CoA. In the absence of acetyl-CoA, acyl-CoA's such as octanoyl-CoA or decanoyl-CoA are incorporated directly into fatty acids by what appears to be intermolecular condensations. Thus, [1-14C] octanoyl-CoA yields C16, and and C24 fatty acids with one-half and one-third, respectively, of the 14C in the carboxyl carbon. We suggest the possibility that, in M. tuberculosis, synthesis of long-chain fatty acids may be accomplished through direct condensation of shorter chain length acyl-CoA's rather than only through a stepwise elongation mechanism.
Processive movement by a kinesin heterodimer with an inactivating mutation in one head.

A single molecule of the motor enzyme kinesin-1 keeps a tight grip on its microtubule track, making tens or hundreds of discrete, unidirectional 8 nm steps before dissociating. This high duty ratio processive movement is thought to require a mechanism in which alternating stepping of the two head domains of the kinesin dimer is driven by alternating, overlapped cycles of ATP hydrolysis by the two heads. The R210K point mutation in Drosophila kinesin heavy chain was reported to disrupt the ability of the enzyme active site to catalyze ATP P−O bond cleavage. We expressed R210K homodimers as well as isolated R210K heads and confirmed that both are essentially inactive. We then coexpressed tagged R210K subunits with untagged wild-type subunits and affinity purified R210K/wild-type heterodimers together with the inactive R210K homodimers. In contrast to the R210K head or homodimer, the heterodimer was a highly active (>50% of wild-type) microtubule-stimulated ATPase, and the heterodimer displayed high duty rat...
Troglitazone-induced fulminant hepatitis: Report of a case with autopsy findings

Troglitazone is an insulin-sensitizing agent used to treat type 2 diabetes mellitus. Several cases have been reported of troglitazone-induced hepatic injury; some requiring transplantation, others resulting in death. We here present a case of troglitazone-induced fulminant hepatic necrosis that led to the death of the patient.
Gene therapy in immune-mediated diseases of the eye

Therapy of ocular immune-mediated diseases has changed dramatically over the past two decades. Although a variety of non-specific immunosuppressive agents are introduced, with advances in cell biology a number of more specific therapeutic options will become available. Gene therapy has the potential to interfere with the immune response at different steps modulating the microenvironment of the eye. In this chapter we focus attention on the most promising candidate genes for gene therapy in ocular immune diseases. Furthermore, we outline the current techniques for delivering genes of interest with their potential merits and drawbacks in the field of ophthalmology. Many of these approaches are still in early phases of study for the treatment of clinical relevant immune-mediated diseases.
Optimizing sensor movement planning for energy efficiency

Conserving the energy for motion is an important yet not-well-addressed problem in mobile sensor networks. In this paper, we study the problem of optimizing sensor movement for energy efficiency. We adopt a complete energy model to characterize the entire energy consumption in movement. Based on the model, we propose an optimal velocity schedule for minimizing energy consumption when the road condition is uniform; and a near optimal velocity schedule for the variable road condition by using continuous-state dynamic programming. Considering the variety in motion hardware, we also design one velocity schedule for simple microcontrollers, and one velocity schedule for relatively complex microcontrollers, respectively. Simulation results show that our velocity planning may have significant impact on energy conservation.
« DIS MOI ce que tu vois ? ». Appréhender la vision de jeunes malvoyants par la description d’une scène

Resume « Que voient les malvoyants ? » En basse vision, il est admis qu’« il y a autant de malvoyances que de malvoyants ». En partant de ce principe, comment apprehender la vision subjective de jeunes deficients visuels par des moyens objectifs, sans aborder des termes medicaux et de maniere a ce que tout un chacun puisse se representer une malvoyance. L’experimentation d’une situation ecologique est conduite depuis 4 ans dans un S3AIS, je propose d’en faire part dans cet article.
Satellite Dynamics Simulator Development Using Lie Group Variational Integrator

Simulation technology is becoming increasingly crucial in the design and optimization of satellites due to the difficulties in testing and verifying system parameters on the ground. Computationally tractable and accurate methods are required in order to test satellite parameters in the complex and dynamic space environment. Although various satellite teams have developed simulation tools, many suffer from inaccurate numerical integrators, resulting in their simulations being of low fidelity for long duration simulations. This paper presents a MATLAB/Simulink-based simulator which includes high fidelity integration and modeling for accurate and relatively quick results. The simulator includes an energy-preserving variational integrator for both translational and rotational dynamics. A Lie Group Variational Integrator is used for the rotational dynamics, which enforces an orthogonality constraint for improved accuracy. This approach requires less computational time relative to other integration methods such as Runge-Kutta method for the same level of integration accuracy. The simulator includes perturbations to the orbital motion and attitude, including Earth oblateness, aerodynamic drag, solar pressure, gravity gradient, and residual dipole. The simulator also includes an advanced hysteresis model for improved modeling of magnetic attitude control systems. Simulation results are provided for a representative small satellite mission in low earth orbit with a passive magnetic stabilization control system. We compare the novel integration and hysteresis techniques to conventional simulators for long duration simulations for a realistic mission scenario.
Maintenance by nerve growth factor of the intracellular sodium environment in spinal sensory and sympathetic ganglionic cells.

Abstract A promising advance in our understanding of the mode of action of nerve growth factor (NGF) has been provided by our recent finding that dissociated cells from 8-day embryonic chick dirsal root ganglia (DRG) lose their competence to maintain a low intracellular Na + when incubated without NGF for 6 h, and promptly recover it on delayed presentation of NGF. To ascertain whether control of intracellular Na + is a general feature of the NGF action on its target neurons, we have now tested several NGF-sensitive tissues, both as intact ganglia and dissociates, for their ability to (i) accumulate large amounts of 22 Na + over a period of hours in the absence of NGF, and (ii) rapidly extrude the accumulated radioactivity upon delayed presentation of NGF. Intact and dissociated chick embryo DRG and sympathetic ganglia, as well as dissociated mouse DRG, displayed the expected Na + responses to the lack or the administration of NGF. No such responses were observed with intact mouse DRG, which do not require NGF in explant cultures for neuritic outgrowth, or with intact and dissociated chick embryo ciliary ganglia, which are not sensitive to NGF in either explant or dissociated cell cultures. Thus, in all ganglionic preparations examined, the occurrence of Na + responses to exogenous NGF correlated with traditional responses to NGF in culture. This, together with other recent data, reinforces the view that ionic control may be a critical element in the mechanism of action of NGF.
1,25-Dihydroxycholecalciferol: its use in the long-term management of idiopathic hypoparathyroidism in children.

The production of 1,25-dihydroxycholecalciferol, 1,25(OH)2D3, is reduced in the absence of parathyroid hormone (PTH), because conversion of 25-hydroxycholecalciferol (25-OHD3) to 1,25(OH)2D3 is primarily under PTH control. By managing idiopathic hypoparathyroidism (IHP) in children with very small doses of 1,25(OH)2D3, 0.40-0.50 µg/day, given orally, the intestinal absorption of calcium (Ca) can be increased to normal and thereby restore and maintain normal serum levels of Ca. Three children with previously untreated, undiagnosed and isolated IHP have been managed in this manner for 2650 treatment days. Two 4-year-old children achieved and maintained normal serum levels of Ca after 1-4 days on 0.03 µg/kg/day of 1,25(OH)2D3. While the hormone was continued, each child was placed on a low Ca diet: the total serum Ca fell by 0.80 to 1.0 mg/dl within 2 days. During 2300 treatment days, both children have remained normocalcemic on a regular diet. The third child, who required phenobarbital throughout treatment...
Nonsustained atrial flutter in a child without congenital heart disease

An 8 1/2-year-old child without heart disease developed nonsustained atrial flutter by programmed atrial stimulation. Atrial re-entry was the underlying mechanism.
WE‐E‐BRB‐08: Commissioning and Benchmarking a 3D Dosimetry System for Clinical Use

Purpose: To commission and benchmark a 3D dosimetry system for clinical use, in particular, for verification and commissioning of complex radiation treatments like VMAT, IMRT and gated treatments. The system is composed of two parts: a radiochromic plastic dosimeter Presage, which responds to absorbed dose with a linear change in optical‐density; and the Duke Large field of view Optical‐CT Scanner (DLOS). Methods: DLOS commissioning involved creating stray light and spectral corrections, determining the dynamic range, spatial resolution, and noise, and characteristics of source and imaging components. The benchmarking tests were performed on the combined DLOS/Presage system to establish baseline capabilities. These tests consisted of delivering 6 treatments of gradually increasing complexity, and comparing the measured distributions with a gold standard (e.g. machine beam‐data). All studies used standard‐ procedures to ensure consistency. Results: Commissioning: isotropic spatial resolution was sub‐mm (MTF >0.5 for frequencies of 1.5;p/mm) and the dynamic range was ∼ 60dB . Flood field uniformity was 10% and stable after 45minutes. Stray light is small, due to telecentricity, but even the residual can be removed through deconvolution. Benchmarking: the mean 3D passing gamma rate (3%, 3mm, 5% dose threshold) over the 6 benchmark data sets was 97.3% ± 0.6% (range 96%–98%), indicating excellent ability to perform 3D dosimetry. Noise was low at ∼2% for 2mm reconstructions. Conclusions: The DLOS/Presage benchmark tests show consistently excellent performance, with very good agreement to simple known distributions. The telecentric design was critical to enabling fast (∼15mins) imaging with minimal stray light artifacts. The system produces accurate isotropic 2mm3 dose data over clinical volumes (e.g. 16cm diameter phantoms, 12 cm height), and represents a uniquely useful and versatile new tool for commissioning complex therapy techniques. The system also has wide versatility, and has successfully been used in preliminary tests with protons, and kV irradiations.
Description of the electrodynamics of a gas by molecular-electromagnetic correlation functions.

Starting from basic principles, we develop a description of the electromagnetic interactions of a molecular gas in terms of a set of correlation functions which we call the molecular-electromagnetic correlation functions (MECF's). First we use the energy eigenfunctions for an isolated molecule of the species of interest to define a set of molecular creation and annihilation operators. We then derive a closed set of operator equations for these molecular creation and annihilation operators and the electromagnetic vector potential. Explicit definitions of the lowest-order MECF's are given in terms of these operators, and it is shown how the operator equations which have been obtained can be used to derive equations of motion for the MECF's. Finally, we illustrate the use of the MECF's in describing physical properties of the molecular gas and the electromagnetic field. Brief indications are given of the application of the MECF formulation to the semiclassical approximation and to the description of quantum emission of radiation, topics which are treated in greater detail in subsequent papers. The basic MECF formulation described here contains three rather mild approximations: (1) Atomic nuclei are treated as elementary particles; (2) nuclei and electrons are treated nonrelativistically; and (3) the effect of molecular collisions with the container walls on the internal molecular state is neglected. Consequently, the physical description contained in the formulation is rather complete; and the MECF results can be used both to provide a sound basis for some aspects of the usual heuristic models, and to ascertain the ways in which those models are incomplete.
Estimating strategic price response using cointegration analysis: The case of the domestic black and herbal tea industries

In this article we develop a vector error correction model using weekly, point-of-purchase scanner data to investigate multivariate pricing relationships among brands competing in the domestic black and herbal tea industries. Johansen's likelihood ratio test established the prices of Bigelow black tea and Celestial Seasonings herbal tea were cointegrated; hence, the pricing decisions of the largest firms in each respective tea market were not unrelated. The black tea prices of Bigelow and Twining, the two largest firms in the black tea market, were cointegrated as well. The cointegrating vectors, speeds of adjustment, and impulse response function analysis provide unique insights into the direction, magnitude, and speed of price response in these value-added, agricultural product markets. [EconLit citations: M100, L200, L660] © 2002 Wiley Periodicals, Inc.
Inhibitory effects of colchicine on ciliogenesis in ectoderm of Xenopus laevis

Antimitotic doses of colchicine inhibit ciliogenesis in tissue cultures of amphibian embryonic epidermis. Different stages of ciliogenesis can be impeded by administering the drug to explants taken from donors of different ages. Colchicine blocks the formation of both centrioles and ciliary shafts when applied to explants from relatively young neurulae. When administered to ectoderm from slightly older embryos, the drug does not interfere with ongoing centriole production but prevents either the initiation of shaft development or the elongation of short shafts that have already formed. Colchicine does not impede ciliary rootlet development, and had no apparent influence on fully differentiated cilia. The striking feature of the treated cells is the formation of electron dense cytoplasmic masses that resemble the so-called precursor bodies postulated to be utilized in the normal development of cilia ( 31 ). We suggest that colchicine disrupts ciliogenesis by preventing the conversion of precursor bodies into the microtubules of ciliary centrioles and shafts.
Free radical reduction mechanisms in mouse epidermis skin homogenates

Scavenging mechanisms for persistent free radicals were investigated using nitroxide-type radicals as model compounds. The free radical reducing activity of a) isolated thioredoxin reductase, a flavin containing oxidoreductase, b) skin homogenates, and c) the epidermis of hairless mice was studied by electron spin resonance spectroscopy. In all three systems, reduction rates of different classes of nitroxide free radicals exhibited the following order: oxazolidinoxy > piperidinoxy > dihydropyrroloxy. The main reductant for piperidinoxy radicals in mouse skin homogenate is ascorbic acid. Other reducing activities were stimulated by NAD(P)H and could be inhibited by N-ethyl maleimide, suggesting involvement of thiol-dependent processes. Mammalian thioredoxin, a competitive inhibitor of nitroxide reduction by thioredoxin reductase, significantly stimulates nitroxide scavenging in skin homogenate. Thioredoxin reductase did not significantly participate in nitroxide reduction in skin homogenates. At the surface of mouse epidermic a cationic dihydropyrroloxy nitroxide, which was stable in the presence of mammalian thioredoxin reductase was readily reduced. The epidermal reduction was inhibited by zinc, N-ethyl maleimide, and by heat (70° C, 5 min). At least for mouse epidermis, reduction of a variety of nitroxides is a complex phenomenon involving enzymatic and nonenzymatic mechanisms and cannot be used as a specific assay for an enzyme. e.g., thioredoxin reductase. The study indicates the epidermis contains an effective antioxidant system that scavenges ascorbate-sensitive piperidinoxy nitroxides as well as more reducing radicals exemplified by dihydropyrroloxy nitroxides.
Intraoperative radiolymphoscintigraphy for detection of occult nodal metastasis in patients with head and neck squamous cell carcinoma.

OBJECTIVES: We sought to determine the feasibility and utility of intraoperative radiolymphoscintigraphy as a screening procedure for the detection of occult metastatic disease in selected cases of head and neck squamous cell carcinoma (HNSCC).METHODS: Patients with accessible primary HNSCC and no evidence of metastatic disease who were already undergoing planned surgical resection of the primary tumor and elective neck dissection met the inclusion criteria. Before resection, a handheld gamma probe was used to find the radiolabeled sentinel lymph node (SLN). The neck specimen was examined ex vivo by using the gamma probe; the SLN or SLNs were dissected free from the specimen and sent separately for histopathologic examination.RESULTS: At least one SLN was identified in all patients enrolled thus far. Four patients had microscopic carcinoma found in the SLN. Two of these had cancer only in the SLN, and two had disease both in the SLN and the remaining specimen.CONCLUSIONS: Intraoperative radiolymphoscintig...
NO and NO-independent mechanisms mediate ETB receptor buffering of ET-1-induced renal vasoconstriction in the rat.

Vascular endothelin (ET) type B (ETB) receptors exert dilator and constrictor actions in a complex interaction with ETA receptors. We aimed to clarify the presence and relative importance of nitric...
High-Al gabbros in the Laramie Anorthosite Complex, Wyoming: implications for the composition of melts parental to Proterozoic anorthosite

High-Al gabbro represents one of the latest phases of magmatism in the 1.43 Ga Laramie anorthosite complex (LAC) in southeastern Wyoming. This lithology, which is mineralogically and geochemically the most primitive in the LAC, forms dikes and small intrusions that cross cut monzonitic and anorthositic rocks. High-Al gabbro is characterized by high Al2O3 (15–19 wt%), REE patterns with positive europium anomalies (Eu/Eu*=1.2–3.8), and the lowest initial 87Sr/86Sr (as low as 0.7033) and highest initial ɛNd (up to +2) in the LAC. Their Sr and Nd isotopic characteristics indicate a mantle origin followed by crustal assimilation during ascent. Intermediate plagioclase (An50–60) and mafic silicate (Fo54–63) compositions suggest that they are not primary mantle melts and that they differentiated prior to final emplacement. High-Al gabbros of the LAC are similar compositionally to gabbros from several other Proterozoic anorthosite complexes, including rocks from the Harp Lake complex and the Hettasch intrusion in Labrador and the Adirondack Mountains of New York. These gabbros are considered to be parental to their associated anorthositic rocks, a theory that is supported by recent experimental work. We interpret LAC high-Al gabbros to represent mantle-derived melts produced by the differentiation of a basaltic magma in an upper mantle chamber. Continued evolution of this magma eventually resulted in the formation of plagioclase-rich diapirs which ascended to mid-crustal levels and formed the anorthositic rocks of the LAC. Because these gabbros intrude the anorthositic rocks, they do not represent directly the magma from which anorthosite crystallized and instead are younger samples of magma formed by identical processes.
Comparison of solutions for TM-polarized nonlinear guided waves

We show that physically realistic solutions for nonlinear TM waves guided by thin dielectric films are obtained in the uniaxial approximation for a dielectric constant proportional to the square of the normal-field component and not of the parallel-field component as assumed previously.
Role of an Acidic Cluster/Dileucine Motif in Cation‐Independent Mannose 6‐Phosphate Receptor Traffic

The endocytic trafficking of the cation-independent mannose 6-phosphate receptor (CI-MPR) involves multiple sorting steps. A cluster of acidic amino acids followed by a dileucine motif in the cytoplasmic tail has been proposed to mediate receptor sorting from the trans Golgi network (TGN) to late endosomes. Mutations in this motif impair lysosomal enzyme sorting by preventing association of CI-MPR with coat proteins. The role of the acidic cluster/dileucine motif in the post-endocytic transport of the receptor was examined using the CI-MPR mutants, AC01 and D160E (Chen HJ, Yuan J, Lobel P. J Biol Chem 1997;272:7003–7012). Following internalization, wild type (WT) CI-MPR is transported through sorting endosomes into the endocytic recycling compartment (ERC), after which it traffics to the TGN and other organelles. However, the mutants localize mostly to the ERC and only a small portion reaches the TGN, suggesting that the sorting of the CI-MPR mutants from the ERC into the TGN is severely impaired. We observed no defect in receptor internalization or in the rate of tail mutant recycling to the cell surface compared to the WT. These results demonstrate that the acidic cluster/dileucine motif of CI-MPR is critical for receptor sorting at early stages of intracellular transport following endocytosis.