cssi/SciSciGPT-SciSciNet huggingface dataset:
Eight-Vertex Metallomesogens: Zirconium Tetrakis-β-diketonate Liquid Crystals

Square antiprism zirconium tetrakis-β-diketonate complexes with 24 alkoxy chains organize in columnar liquid crystal phases. X-ray diffraction and polarized microscopy studies on complexes with n-alkoxy side chains revealed a columnar hexagonal phase. These sandwich-shaped compounds have much lower transition temperatures than their discotic analogues, which leads to the desirable attribute of room temperature liquid crystallinity. The addition of two branching methyl groups to the alkoxy chains was found to dramatically alter the properties of these materials. The branched side chain analogues exhibited a higher clearing point while the liquid crystallinity is maintained at room temperature. The branching methyl groups also induced a bulk reorganization of the material to a rare columnar oblique phase (Colob).
Optimal vehicle stability controller based on Nash strategy for differential LQ games

This paper introduces a novel optimal vehicle stability controller in the presence of driver model. The concept is inspired by Nash strategy for exactly known systems with more than two players. In the presented method, the driver, commanding the steering angle, and the vehicle stability controller, applying compensated yaw moment, are defined as two players in a differential linear quadratic game. As a result, a novel optimal control algorithm is developed. Evaluated by a nonlinear vehicle model, numerical simulations are done for a single lane change manoeuvre, and preliminary results show the effectiveness of this controller over linear quadratic regulators.
On the singularity structure of invariant curves of symplectic mappings.

We study invariant curves in standard‐like maps conjugate to rigid rotation with complex frequencies. The main goal is to study the analyticity domain of the functions defined perturbatively by Lindstedt perturbation expansions. We argue, based on infinite‐dimensional bifurcation theory that the boundary of analyticity should typically consist of branch points of order two and we verify it in some examples using nonperturbative numerical methods. We show that this nature of the singularities of the analyticity domain can explain previously reported numerical results and also suggests other numerical methods.
On the influence of cloud fraction diurnal cycle and sub-grid cloud optical thickness variability on all-sky direct aerosol radiative forcing

Abstract The objective of this study is to understand how cloud fraction diurnal cycle and sub-grid cloud optical thickness variability influence the all-sky direct aerosol radiative forcing (DARF). We focus on the southeast Atlantic region where transported smoke is often observed above low-level water clouds during burning seasons. We use the CALIOP observations to derive the optical properties of aerosols. We developed two diurnal cloud fraction variation models. One is based on sinusoidal fitting of MODIS observations from Terra and Aqua satellites. The other is based on high-temporal frequency diurnal cloud fraction observations from SEVIRI on board of geostationary satellite. Both models indicate a strong cloud fraction diurnal cycle over the southeast Atlantic region. Sensitivity studies indicate that using a constant cloud fraction corresponding to Aqua local equatorial crossing time (1:30 PM) generally leads to an underestimated (less positive) diurnal mean DARF even if solar diurnal variation is considered. Using cloud fraction corresponding to Terra local equatorial crossing time (10:30 AM) generally leads overestimation. The biases are a typically around 10–20%, but up to more than 50%. The influence of sub-grid cloud optical thickness variability on DARF is studied utilizing the cloud optical thickness histogram available in MODIS Level-3 daily data. Similar to previous studies, we found the above-cloud smoke in the southeast Atlantic region has a strong warming effect at the top of the atmosphere. However, because of the plane-parallel albedo bias the warming effect of above-cloud smoke could be significantly overestimated if the grid-mean, instead of the full histogram, of cloud optical thickness is used in the computation. This bias generally increases with increasing above-cloud aerosol optical thickness and sub-grid cloud optical thickness inhomogeneity. Our results suggest that the cloud diurnal cycle and sub-grid cloud variability are important factors to be accounted for in the studies of all-sky DARF.
Bringing Reality to "Real Options": An Experiential Exercise.

Issues surrounding the contextual environment in which strategic decisions are made are difficult concepts to grasp, particularly for undergraduate students with little business experience. They are also problematic for graduate students that have not been called on to make such decisions within their career. The authors propose an exercise that blends many elements of decision making under uncertainty and risk. Students are placed in an environment in which their own choice may differ from that of the team, but in which the team's performance will have explicit implications on their individual performance and rewards. The exercise incorporates team dynamics and problem-solving capabilities in a temporally and competitively constrained environment.
Application of modern quality improvement techniques to rapid thermal processing

Modem statistical modeling techniques are applied to the characterization and optimization of Rapid Thermal Chemical Vapor Deposition. The problems of deposition during process ramps and thickness uniformity modeling wafer are addressed. A two-phase fractional factorial experimental design is used to generate models for the deposition rate, uniformity measures, and normalized time responses. A constrained algebraic optimization algorithm is used to find the optimum settings for the reactor for the deposition of 2000A of polysilicon. The methods that are developed to handle these problems are shown in an application to the deposition of polysilicon in a LeiskTM reactor.
The search for black radicals: American and British documents relative to the 1919 red scare

(1975). The search for black radicals: American and British documents relative to the 1919 red scare. Labor History: Vol. 16, No. 2, pp. 272-284.
Perceived segmentation of center from surround by only illusory contours causes chromatic lateral inhibition.

Abstract When a light and also its surrounding context slowly oscillate in chromaticity over time, the color appearance of the light depends on the relative phase of center and surround. The influence of the surround is generally accounted for by retinotopic center–surround organization, with the surround inhibiting signals from the center. The traditional neural account, however, cannot rule out lateral inhibition due to cortical mechanisms sensitive to object segmentation cues. Experiments here reveal that illusory contours are sufficient to separate a center from its surround. Observers adjusted the Michelson contrast of a matching disk to equal the perceived modulation depth of a central area within a surround. Both the central test and matching disk were maintained at constant luminance and modulated in-phase at 2 Hz along one chromatic axis (L/(L + M) or S/(L + M)). The center was perceptually segmented from the surround by either a physical (retinotopic separation) or illusory (cortically represented) triangle contour. Segmentation of center from surround by the illusory contour strongly attenuated the perceived modulation depth for both chromatic axes. Further, the strength of attenuation was consistently greater with the illusory than the physically segmenting triangle. This cannot be accounted for by retinal center–surround antagonism; instead it points to a cortical neural representation of contours, with lateral inhibition following neural mechanisms sensitive to object segmentation cues.
The Roman Inquisition's precept to Galileo (1616)

On 26 February 1616 Galileo was ordered to cease to defend heliocentrism in any way whatsoever. This order, called a precept, automatically applied to anything he might later attempt to publish on the subject. Issued at the end of his first trial by the Roman Inquisition, the precept became the spark that triggered his second trial in 1632-3 and figured importantly in the justification of his sentence. This precept has been a subject of controversy since the late nineteenth century for its authenticity, legality and legitimacy. This paper addresses the first two points and establishes the facts of what probably happened in 1616. It does so by examining seven texts that bear on the event. All but one of these (plus Galileo's first deposition in 1633) agree tolerably well that Galileo did indeed receive the precept in the strongest form. An examination of the singleton text in the context of how the Inquisition produced and kept its records as well as of its procedures and personnel shows that it is the least reliable source. This context also supports the argument that certainty about what happened is impossible to achieve. The theory that the document most damaging to Galileo was a forgery is also disposed of. Examination of the crucial phrase successive ac incontinenti in one of the documents supports the paper's suggestion that more caution is in order before accepting the currently nearly universal claim that the precept was improper in law.
Nucleotide bias observed with a short SELEX RNA aptamer library

Systematic evolution of ligands by exponential enrichment (SELEX) is a powerful in vitro selection process used for over 2 decades to identify oligonucleotide sequences (aptamers) with desired properties (usually high affinity for a protein target) from randomized nucleic acid libraries. In the case of RNA aptamers, several highly complex RNA libraries have been described with RNA sequences ranging from 71 to 81 nucleotides (nt) in length. In this study, we used high-throughput sequencing combined with bioinformatics analysis to thoroughly examine the nucleotide composition of the sequence pools derived from several selections that employed an RNA library (Sel2N20) with an abbreviated variable region. The Sel2N20 yields RNAs 51 nt in length, which unlike longer RNAs, are more amenable to large-scale chemical synthesis for therapeutic development. Our analysis revealed a consistent and early bias against inclusion of adenine, resulting in aptamers with lower predicted minimum free energies (ΔG) (higher str...
Silicon Containing Photoresists

This work describes several novel Si-containing polymers with low optical densities at 193nm and acid labile protecting groups. These materials are evaluated at 193nm lithography as one of the top surface imaging techniques to enhance lithography performance. Additionally, norbornene/maleic anhydride copolymers containing silicon side chains are synthesized. Experimental results indicate that the unexposed and exposed regions differ in terms of silicon content to the extent that patterns are formed using oxygen reactive ion etching. Moreover, a polymer with at least 3.5%wt of Si content can provide effective etch resistance in this study. 0.11μm line/space patterns are also obtained using conventional developer with an ArF excimer laser stepper.
Structure and function: Brain electrical activity mapping and computed tomography in schizophrenia ☆

A computerized topographic technique that maps brain electrical activity is applied to the investigation of neurophysiological abnormalities in medicated and drug-free schizophrenic patients. This topographic approach uses EEG and evoked potentials to provide functional measures of electrophysiological abnormalities. Neurophysiological differences between schizophrenic patients and controls are delineated which add further evidence that frontal lobe dysfunction may be relevant to our understanding of schizophrenia. An initial investigation employs computed tomography to examine the relationship of structural anatomical pathology in schizophrenia with the functional abnormalities that may be defined using brain electrical activity mapping. When schizophrenic patients with and without frontal cortical atrophy were compared, electrophysiological differences were delineated that overlay frontal cortical regions. This preliminary work suggests that in schizophrenia, abnormal electrophysiological function is associated with definable gross morphological abnormalities of the brain.
No-carrier-added (4-fluoro-3-[131I]iodobenzyl)guanidine and (3-[211At]astato-4-fluorobenzyl)guanidine.

With 3-bromo-4-fluorotoluene as starting material, [4-fluoro-3-(trimethylsilyl)benzyl]guanidine was prepared in five steps in 1.5% overall yield. Radioiodination of this silicon precursor using N-chlorosuccinimide in trifluoroacetic acid at room temperature for 5 min gave (4-fluoro-3-[131I]iodobenzyl)guanidine ([131I]FIBG) in 50−60% radiochemical yield. A byproduct which had a retention time in two HPLC systems similar to that of (m-iodobenzyl)guanidine (MIBG) was formed in about 30% yield. [131I]FIBG was stable up to 3 h under these conditions of iodination, indicating that the byproduct is not generated as a result of [131I]FIBG degradation. Using hydrogen peroxide as the oxidant in aqueous medium and a reaction time of 30 min at 50 °C, yields of [131I]FIBG could be increased to 75−80%, with less than 7% of the byproduct formed under these conditions. Astatination of the silicon precursor using N-chlorosuccinimide in trifluoroacetic acid at 70 °C gave 65−70% radiochemical yield of (3-[211At]astato-4-flu...
CAI in writing at the university: some recommendations

Abstract Most writing programs are moving beyond drills to potential applications of the computer to invention, teacher-student communications, student record-keeping and databases for research, and especially to integrated programs combining wordprocessing, editing, grammatical and stylistic analysis, invention, and instructor intervention in the writing process. A new frontier is being generated by the interface between AI and English studies in composition and literature.
Idiopathic megaduodenum; report of a case.

A case of idiopathic megaduodenum, together with a brief discussion, has been presented because of the extreme rarity of the condition, there being only approximately a dozen such cases reported in the literature.
Sparse matrix computations

Numerical linear algebra plays a vital role in all parts of computational mathematics, such as differential equations and optimization, and in many application areas, such as control theory. Large systems in these areas generally lead to linear algebra problems involving large sparse matrices (i.e., matrices of large dimension, but whose entries are mostly zeros). Efficient use of computer resources in solving such sparse matrix problems requires special techniques which have a distinct flavor compared to those used for dense matrices. We survey the current state of the art in sparse matrix computations, including the solution of systems of linear algebraic equations, linear least squares problems, and eigenvalue problems. Emphasis is placed on direct methods, but iterative methods are also considered. We also emphasize the concrete and useful expression of algorithms in the form of computer software.
Ocular Herpes Simplex Infections

Not surprisingly, ocular herpes simplex infec­ tions seem enigmatic to the nonophthalmologic physician in comparison with the stereotyped course of other types of mucocutaneous herpes simplex infections. In general terms, the major affliction of nonocular mucocutaneous disease— for example, herpes genitalis and herpes labialis—is frequent recurrence of painful cutaneous disease that is not amenable to topical antiviral therapy. These infectious episodes are generally self-limited and rarely cause structural altera­ tions in affected tissues. In contrast, ocular herpes simplex infections are less likely to recur but may result in chronic inflammatory disease of the cornea, an avascular, transparent structure that serves as an interface between the external ocular environment and the receptive visual neurosensory tissues of the eye. Consequently, although frequent painful erup­ tions are the major source of morbidity in pa­ tients with herpes genitalis or labialis, ocular herpes simplex is less a problem of recurrence than of structural alterations of the eye and secondary loss of vision. One can contrast the reported rates of recurrence of genital herpes simplex virus type 2 of 0.33 per month (in 24 of 27 patients or 89%) and orolabial herpes simplex virus type 1 infections of 0.12 per month (in 5 of 12 patients or 42%) in one study1 with the 40% ocular recurrence rate during a 5-year period for patients with corneal epithelial herpetic kerati­ tis. 2 Multiple recurrences are thus more common with genital or oral herpes in contrast with iso­ lated or infrequent recurrences of ocular herpes simplex. The major complications of ocular herpes simplex occur in deep herpetic corneal and intra­ ocular inflammatory infections that may have a tendency toward chronicity, result in loss of vision, and, in a small subpopulation of pa­ tients, necessitate surgical rehabilitation. In the
Thermodynamics of interstitial-f.c.c. solutions based upon kinetic considerations

Abstract A thermodynamic model has been developed for interstitial-f.c.c. solutions where repulsive interactions exist between interstitials. The basis for this model is an assessment of the equilibrium number of paired and unpaired interstitials by means of a dynamic balance. From this information, expressions for the internal energy and the configurational entropy as functions of the interstitial interaction energy and composition are developed. The activity of the interstitial species in solution may be thus found through the partial molar free energy of solution. Tests of the model against experimental data from the carbon-austenite and nitrogen-austenite systems show satisfactory agreement.
Meteor stream activity. III. Measurement of the first in a new series of Leonid outburst

— In 1994 November, a shower of bright Leonid meteors signaled what is likely the first meteor outburst of Leonids associated with the upcoming return of comet P/Tempel-Tuttle to perihelion. Measurements of meteor activity and the meteor brightness distribution are presented. By comparing the present observation with those of past Leonid returns, a forecast is made of the time, the duration, the intensity, and the mean meteor brightness of Leonid outbursts that may occur if previously observed patterns are repeated in the forthcoming years.
The cellular transport of calcium in rat liver.

The bidirectional transport of calcium in rat liver was studied using slices labeled with Ca47 in a closed two compartment system. Steady-state conditions were observed with influx and efflux transfer coefficients of 0.070 and 0.018 per minute, respectively. The rapidly exchanging cell fraction of calcium existed at a concentration three times higher than the average cell concentration of calcium and occupied cell loci comprising less than 25% of the cell mass, suggesting that calcium associated with the cell membranes, nuclei, and mitochondria participated in the rapidly exchanging fraction. At pH 7.4 and 377deg;C, the influx transfer coefficient was 25% above the steady-state condition and accumulation of calcium by the slices occurred. Studies of the effects of varied physical and chemical conditions revealed that the influx transfer coefficient was increased by elevated pH, strontium, certain metabolic inhibitors, and 2 mM concentrations of cyclic adenosinemonophosphate and adenosinetriphosphate. The influx transfer coefficient was decreased by reduced temperature, decreased pH, magnesium, and 10 mM adenosinetriphosphate. The efflux transfer coefficient was increased by elevated pH, strontium, iodoacetate, and adenosinetriphosphate, and was decreased by reduced temperature and by N-ethylmaleimide. These data support the thesis that cell transport of calcium is accomplished by the attachment of calcium atoms to the cell surface and transport through the plasma membrane bound to either specific carriers or to membrane constituents. Conditions which change the affinities, capacities, and mobilities of plasma membrane ligands that bind calcium or cause extracellular chelation of calcium are capable of altering the rate of calcium transport.
Applications of algebra to concentration calculations

Abstract The concentration vector of a mixture of air masses is expressed in vector-matrix form and the exhaust-concentration problem is studied by using a new algebraic element called a Scator.
Infrared spectra of doped CO2 crystals and their relationship to vibrational energy transfer

Abstract The antisymmetric stretching frequencies of several CO2 and N2O isotopes in both 12CO2 and 13CO2 hosts are reported and used to determine the contribution of guest-host excitation exchange interactions to the frequency shifts of the guests from the gas phase. The relationship between these results and other phenomena which depend on excitation exchange interactions is discussed.
Postmenopausal Estrogens in Prevention of Osteoporosis Benefit Virtually without Risk if Cardiovascular Effects Are Considered

Postmenopausal estrogens can delay or prevent osteoporosis and decrease the frequency of fractures, but they also increase the risk of endometrial cancer. A decision analytic model was developed using a Markov process with 18 different states to estimate quality-adjusted life expectancy with and without estrogen therapy. The model considered fractures of the hip, wrist, pelvis, humerus and spine with potential outcomes of short-term morbidity, long-term disability, nursing home placement, and death. Quality adjustments were based on expert opinions. In sensitivity analyses, various risks of endometrial cancer and hysterectomy due to estrogens were examined. The effect of estrogen therapy on cardiac mortality also was considered. For a cohort of 50-year-old white women who would take estrogens for 15 years, the analysis showed a benefit of 0.47 years but 0.67 quality-adjusted years. For every five-fold increase in the relative risk of endometrial cancer, the benefit decreases by 0.07 quality years. The benefit would increase by 0.17 quality years for each 10 percent decrease in the fracture rate and 0.32 for each 10 percent decrease in cardiovascular mortality rate. Thus, estrogen therapy provides a significant gain in quality-adjusted life expectancy. In considering the efficacy of any drug, all the benefits of the drug as well as all its risks must be included. If the beneficial effect of estrogens on cardiovascular mortality is confirmed, it will overshadow all other effects. Any recommendation about postmenopausal estrogens with respect to osteoporosis that excludes their cardiovascular effects markedly underestimates the potential gains from therapy.
Influence of size on the sources of energy consumed by overwintering walleye pollock (Theragra chalcogramma)

Abstract The critical size hypothesis proposes the risks of winter mortality are greatest for small individuals in fish populations. This results from size-dependent predation and starvation of wintering fishes. We extend this idea to walleye pollock (Theragra chalcogramma) and argue size-dependence leads to different wintering strategies among subadult life stages. We sampled fish quarterly, measured their size, growth and energy allocation. By comparing the contributions of endogenous energy sources (storage and structure) to metabolic demand in young-of-the-year (YOY) and juvenile pollock over winter we determined how length influenced their winter foraging requirement. From this we inferred the relative risks of starvation and predation for different sized fish. Young-of-the-year (≤ 170 mm) experienced high starvation risk and relied on foraging to meet routine metabolic cost. Consequently, they consumed relatively little storage or structural energy over winter. In contrast, juveniles (> 170 mm and ≤ 270 mm) responded to the risk of predation by consuming significant amounts of protein and structural lipids while minimizing foraging. Consistent with these observations we found YOY maximized growth in fall while juveniles maximized energy storage. In spring, YOY resumed growth earlier than juveniles. These data indicate the critical size and period hypothesis can be extended to walleye pollock.
Helicity-dependent photoabsorption cross sections on the nucleon

We examine the energy dependence of single-meson photoproduction as it contributes to the Gerasimov-Drell-Hearn (GDH) sum rule. For photon energies above approximately 1 GeV, through the full resonance region, this contribution dominates the proton sum-rule integral. Over the same energy region, our single-pion contribution to the neutron sum rule also qualitatively follows a recent set of GDH data. The predicted neutral-pion contribution to the neutron sum rule is nearly zero above 1 GeV in this result. The SAID and Mainz (MAID) results are very different for a number of observables over this energy region.
Chiral Symmetry Breaking and Pattern Formation in Two-Dimensional Films

Thin films of organic molecules, such as Langmuir monolayers and freely suspended smectic films, can exhibit a spontaneous breaking of chiral symmetry. This chiral symmetry breaking can occur through at least three possible mechanisms: (1) the relation between tilt order and bond-orientational order in a tilted hexatic phase, (2) a special packing of non-chiral molecules on a two-dimensional surface, and (3) phase separation of a racemic mixture. Because the chiral order parameter is coupled to variations in the direction of molecular tilt, chiral symmetry breaking leads to the formation of patterns in the tilt direction with one-dimensional or two-dimensional order. Using a Landau theory, we investigate these patterns and predict the critical behavior near the chiral symmetry breaking transition.
Thermal study of a cryogen-less MgB2 cavity

Recent efforts towards production of high-quality magnesium diboride (MgB 2 ) coatings have raised the possibility of producing usable accelerating cavities. Work continues to reliably produce films of sufficient quality over the large, complex surface area of an accelerating cavity, but this technology would open many interesting technical opportunities. One of these is to replace the traditionally required liquid helium cryogenic systems with a dry system based on cryocoolers. This is made possible by the much higher T c T c of MgB 2 , allowing operation closer to 30 K where cryocooler efficiency becomes competitive with alternative systems. This removes the need for pressure vessels in the cryomodule as well as internal distribution systems, greatly simplifying cryomodule design and fabrication. The lack of uniform cooling over the cavity surface, however, complicates behavior by coupling RF losses, heat leak, and cooling design in a way not seen in traditional SRF cavities. In this paper, these complexities are explored, including realistic cryocooler performance, temperature dependant RF losses, and standard thermal management challenges.
Crane Basic Boom Static Analysis Based on ANSYS

This article studied the 13 m basic boom of SC50C hydraulic crawler crane, and made static analysis on crane basic boom by applying ANSYS, and obtains the stress distribution. Based on the features of the loads and structure of the crane basic boom, this paper sets up a finite element model of it, thus providing reference for the design and optimization of crane boom.
Time-dependent decreases in apparent pA2 values for naltrexone studied in combination with morphine in rhesus monkeys.

One assumption of Schild analyses, which have been used extensively to characterize opioids in vitro and in vivo, is that the concentration of antagonist is at equilibrium; violation of this assumption would yield slopes of Schild plots that deviate from unity. For in vivo studies, the concentration of antagonist changes as it is eliminated; however, if studies are conducted at a time when the antagonist is maximally effective, the assumption of equilibrium is not violated. The goal of these studies was to determine how increasing the delay between antagonist administration and determination of dose–effect curves alters results of Schild analyses. Monkeys received 3.2 mg/kg/day of morphine and discriminated naltrexone while responding under a fixed-ratio 5 schedule of stimulus-shock termination. In monkeys acutely deprived of morphine (27 h), naltrexone was administered 1, 2, 4, or 6 h before determination of morphine dose–effect curves. Morphine-deprived monkeys responded on the naltrexone-appropriate lever, and this effect was reversed by morphine. Naltrexone dose- and time-dependently antagonized morphine. Schild analyses yielded slopes that did not deviate from unity; however, as the delay between naltrexone administration and determination of morphine dose–effect curves increased, apparent pA2 values decreased. The assumption of equilibrium of antagonist at receptor sites does not appear to be violated, regardless of when it is administered, and changes in naltrexone concentration as it is eliminated are reflected in orderly decreases in potency. These results further indicate the strength of Schild analyses for describing interactions between drugs and receptors in vivo.
Molecular dynamics simulations of grain boundary thermal resistance in UO2

By means of molecular dynamics (MD) simulations, we have calculated Kaptiza resistance of UO2 with or without radiation damage. For coincident site lattice boundaries of different configurations, the boundary thermal resistance of unirradiated UO2 can be well described by a parameter-reduced formula by using boundary energies as variables. We extended the study to defect-loaded UO2 by introducing damage cascades in close vicinity to the boundaries. Following cascade annealing and defect migrations toward grain boundaries, the boundary energy increases and so does Kaptiza resistance. The correlations between these two still follow the same formula extracted from the unirradiated UO2. The finding will benefit multi-scale modeling of UO2 thermal properties under extreme radiation conditions by combining effects from boundary configurations and damage levels.
An Improved Method to Derive Surface Albedo from Narrowband AVHRR Satellite Data: Narrowband to Broadband Conversion

Abstract A method was investigated to estimate broadband surface shortwave albedo from the narrowband reflectances obtained by the Advanced Very High Resolution Radiometers (AVHRRs) on board the polar orbiting satellites. Field experiments were conducted to measure simultaneously multispectral narrowband reflectances and broadband albedo over various vegetation and soil surfaces. These data were combined to examine the behavior of narrowband-to-broadband (NTB) conversion factors for different surfaces. Many previous studies have used constant NTB conversion factors for the AVHRR data. The results from this investigation indicate that the optimal NTB conversion factors for AVHRR channels 1 and 2 have a strong dependence on the amount of green vegetation within the field of view. Two conversion factors, f1 and f2, were established to quantify, respectively, 1) the relationship between the reflectance in the narrow red wave band and the total reflectance within the whole visible subregion (0.3–0.685 μm) and ...
Noncytokinetic Radiation Injury: Anticoagulants as Radioprotective Agents in Experimental Radiation Hepatitis

Rats that have been irradiated with a single dose of 1500 roentgens directed to the liver show the following abnormalities: increased clearance of colloidal gold by the liver at 30 days, a decreased albumin space index at 30 days, and increased alkaline phosphatase at 60 days. In each of these cases, animals receiving Depo-heparin in dose ranges reasonable for human application had essentially normal values. There was no radioprotective effect with salicylates at the doses used. Higher doses of salicylates resulted in death of the animals.
Fine structure of resting and germinatingPenicillium chrysogenum conidiospores

The fine structure of resting and germinating conidia ofPenicillium chrysogenum has been examined by electron microscopy. In addition to enlargement of the cells, a number of changes in ultrastructure become evident as morphogenesis proceeds. The newly synthesized germ tube is continuous with the corresponding layers of the conidial wall. Some conidial wall layers, however, do not extend into the hyphal wall. Several sections showing initial septum synthesis suggest that a septal pore is not a necessary structural entity. A characteristic orientation of the initial septum formed after germination is described. Aside from numerical considerations, no significant changes occur in nuclei, mitochondria, or ribosomes. The electron micrographs illustrate the presence of spherosomes, lomasomes, and nucleoli; the possible significance of these structures is discussed.
Hot-electron trapping in thin LPCVD SiO 2 dielectrics

The electron-trapping and surface-state generation characteristics of thin LPCVD SiO 2 dielectrics have been studied using avalanche hot-electron injection. Layered structures of thermal and LPCVD oxide have been examined as a function of anneal time and temperature. After a 1000°C anneal, bulk trapping in the LPCVD oxide was reduced to levels comparable to those in a high-quality dry thermal oxide. Sensitivity to remaining traps was reduced by the presence of a thermal oxide layer on the semiconductor surface. After a post-deposition anneal (PDA), these layered surfaces demonstrated hot-electron performance equal to that of thermal oxide within measurable limits. Also, layered structures generally demonstrated better resistance to surface-state generation than thermal oxides alone. Since less chlorine is incorporated into the layered structures during fabrication, this result is consistent with a recent model identifying broken chlorine bonds as the origin of surface states.
Detecting Snap-through Boundaries using an Adaptive Parameter Space Approach

Parametric space investigation for nonlinear response of post-buckled structures is essential in understanding the dynamics and avoiding potential catastrophic failures. Typically, continuation type approaches are utilized for such studies. However, in case of randomly forced structures, brute force simulations are utilized to understand the parameter space of interest. In this paper an adaptive meshing approach is used in conjunction with parameter space sampling so as to save computational resources and yet provide enhanced insight in to the nonlinear phenomenon of interest. It is shown that the detection of snap-through response boundaries for a flat, buckled beam under random excitation can be efficiently and accurately generated using this approach. Some observations about the accuracy and performance of the approach are presented as well as comparison to a common brute force sampling algorithms.
Extractability of Metal Sulfide Minerals in Acidic Solutions: Application to Environmental Studies of Trace Metal Contamination within Anoxic Sediments

Sulfide minerals are an important sink for metals within anoxic sediments. Extraction techniques using cold HCl to measure the concentration of sulfide mineral associated trace metals have gained wide acceptance as a proxy for potential metal bioavailability within the environmental community. However, certain metal sulfide phases that can potentially release metals into a more bioavailable phase do not extract in HCl. Laboratory experiments have shown that covellite (CuS), chalcocite (Cu2S), cinnabar (HgS), millerite (NiS), heazlewoodite (Ni2S3), and vaesite (NiS2) are poorly soluble in HCl; while greenockite (CdS), mackinawite (FeS1-x), pyrrohtite (FeS), galena (PbS), and sphalerite (ZnS) are highly soluble in HCl. Surface area can also affect the apparent solubility of CuS and NiS in HCl. These results indicate that use of HCl-based extraction schemes (e.g., AVS/SEM ratios) to assay sediments for metal contamination could underestimate the potential bioavailability of several metals of general interest...
Duplication of the ileum

Abstract A case of duplication of the ileum has been presented and the embryology, pathology, clinical findings and treatment have been discussed.
Calcified lymph node metastases from carcinoma of the cervix

A case report of a 61-year-old Negro woman with Stage IV carcinoma of the cervix, who developed calcified lymph node metastases, is presented. Ten years later, she is still alive and well. The well-differentiated squamous cells comprising this tumor with hyalinization and calcification may account for her long survival.
Intensity measurements in the v4-Fundamental of 13CH4 at planetary atmospheric temperatures

Abstract Measurements of spectral transmittance have been performed in the v4-fundamental band of 13CH4 at low temperatures of planetary atmospheric interest with spectral resolution of 0.06 cm-1. Comparison of observed and computed spectral transmittance on a line-by-line basis has yielded line strengths. Best agreement between measured and computed spectra was obtained when the absolute intensity of the band was taken as 123 cm-2 atm-1 at 296 K.
Spatial Multisensory Cueing to Support Visual Target-Acquisition Performance:

The impact of spatial multisensory cues on target-acquisition performance was examined. Response times (RTs) obtained in the absence of spatial cues were compared to those obtained when tactile, auditory, or audiotactile cues indicated the target location. Visual scene complexity was manipulated by varying the number of visual distractors present. The results indicated that all these spatial cues effectively reduced RTs. The benefit of cueing was greater when more distractors were present and when targets were presented from more eccentric locations. Although the benefit was greatest for conditions containing auditory cues, tactile cues alone had a large benefit. No apparent advantage of audiotactile cues over auditory cues was observed, suggesting that the auditory cues provided sufficient information to support performance. Future research will explore whether audiotactile cues are more helpful when the auditory cues are degraded (e.g., when presented in noisy environments or in generic virtual auditory...
Cytogenetic analysis of bone marrow and peripheral blood samples stored in fixative for several years.

We have developed a method which improves the spreading of chromosomes and permits banding analysis of cytogenetic samples of bone marrow and unstimulated peripheral blood which have been stored in fixative for up to 15 years. Metaphase cells had been harvested as usual and stored in fixative (acetic acid:methanol 1:3) at -15 C. The procedure includes 4-5 changes of fixative (acetic acid:ethanol 1:1). Next, cells are dropped onto a chilled, wet slide. The back of the slide is then rinsed with 70% ethanol and dried by ignition. C-, G-, Q-, or R-banding patterns can now be obtained with these specimens. The procedure is useful for reinvestigation of cytogenetic samples that were obtained prior to the development of banding techniques.
Growth rate of the vomer in normal and cleft lip and palate human fetal specimens.

The present study, part of an ongoing investigation of normal and dysmorphic development of the human fetal oronasal capsule, examined the rate of growth of the vomer. For comparative purposes, 29 human fetal specimens (20 "normal" and 9 cleft lip and palate [CLP]) were celloidin embedded, sectioned, stained with hematoxylin and eosin, and serially digitized. The specimens ranged from 8 to 21 weeks in postmenstrual age. The application of a well-documented three-dimensional reconstruction technique provided quantification of several aspects of the vomer. CLP vomer length and volume were growing at a faster rate in the 8 to 21 week age range. Growth curves were produced by plotting length and volume against postmenstrual age and a significant difference was noted between the slopes (growth rate) of the linear component of the normal and CLP growth curves for vomer length (p less than .001) and volume (p less than .001). This study tested the hypothesis of a more rapidly growing 8 to 21 week CLP vomer and observed that the growth trends of the CLP vomer are similar to those of the CLP nasal septum, which also was found to possess a significantly larger (p less than .001) volumetric growth rate throughout the course of the vomer. Comparative findings suggest that a pathogenetic correlate of CLP is the rapid enlargement of the midline structures of the oral and nasal capsules.
X-ray fluorescent determination of uranium in the gaseous phase

Abstract The pressure of uranium in gaseous UF 6 inside a cylinder can be measured using X-ray fluorescence. A highly collimated source, highly collimated detector, and a very rigid geometry are required. This measurement technique is independent of the deposit that forms on the inside wall of the cylinder due to chemical reactions of UF 6 gas with impurities. The technique is applicable for gaseous UF 6 at low pressures where other techniques fail. The deyectability limit, assuming a 25 mCi 57 Co fluorescing source, is less than 1 Torr gas pressure in a 30 min count time.
Continuous Collision and Interference Detection for 3D Geometric Models

This paper describes a new approach to perform continuous collision and interference detection between a pair of arbitrarily complex objects moving according to general 3-dimensional affine motions. Our approach, which does not require any envelope computations, recasts the problem of detecting collisions and computing the interfering subsets in terms of inherently parallel set membership classification tests of specific curves against the original (static) geometric representations. We show that our approach can compute the subsets of the moving objects that collide and interfere, as well as the times of collision, which has important applications in mechanical design and manufacturing. Our approach can be implemented for any geometric representation that supports curve-solid intersections, such as implicit and parametric representations. We describe an implementation of the proposed technique for solids given as a boundary representation (B-rep), and illustrate its effectiveness for several rigid and deformable moving objects bounded by tesselated and freeform surfaces of various complexities. Furthermore, we show that our approach can be extended to also identify the local and global self-intersections of the envelopes of the moving objects without requiring to compute these envelopes explicitly. The paper concludes by summarizing the proposed approach as well as reviewing relevant computational improvements that can decrease the computational cost of the prototype implementation by orders of magnitude.
Performance of Surgical Robots with Automatically Generated Spatial Virtual Fixtures

Our recent work on robotic surgical assistant systems has led us to develop a method to generate spatial motion constraints associated with complex 3D geometry for controlling a robot in a complicated working configuration. An application of specific interest is sinus surgery, in which complicated anatomic structure constrains the motion of the endoscope and other instruments, which are inserted through the nose into a sinus cavity. We have implemented this method in both hands-on cooperative operation and teleoperation control mode. We evaluate and compare user performance in these two operation modes. We show that cooperative operation is more intuitive for the user and easier to use. On the other hand, due to the robot stiffness of our current implementation, teleoperation mode shows more accurate. Both of these two robot-assisted modes significantly improve human’s performance compared to the totally freehand motion.
Spatial Ability and Achievement in Introductory Physics.

This research was undertaken to clarify the nature of the relationship between visual-spatial abilities and achievement in science courses. A related purpose was to determine what influence visual-spatial abilities have on the high attribution rate characteristic of many introductory college-level science courses. Three sections of introductory college level physics (S = 136) and one nonscience liberal arts section (S = 52) received pre- and postmeasures of visual-spatial ability in the areas of perception, orientation, and visualization. Increases in visual-spatial abilities were greatest with an experimental section that received a spatial intervention. These gains were related to test items that utilized graphical form and to laboratory work. Substantial gains in visual-spatial ability were also registered by a placebo and by control sections. These increases suggest that taking introductory physics improves visual-spatial abilities. Although students who withdrew from the course demonstrated mathematics skills comparable to those of students who completed the course, their scores on perception tests were appreciably lower. Visual-spatial scores of the liberal arts group were lower than those of the physics sections, suggesting that visual-spatial ability influences course selection.
A 3‐D empirical model of F region Medium‐Scale Traveling Ionospheric Disturbance bands using incoherent scatter radar and all‐sky imaging at Arecibo

[1] Perhaps the most persistent and prominent of the midlatitude nighttime F region phenomena observed with all-sky imagers is the Medium-Scale Traveling Ionospheric Disturbances (MSTID) that occur when the geomagnetic activity is low. We introduce a simple empirical 3-D model of these bands, which was developed on the basis of an extension of results given by Seker et al. (2008). Seker et al. (2008) reported observational results on the 3-D geometry of MSTID structures found using combined incoherent scatter radar (ISR) and all-sky imager observations over the Arecibo Observatory in Puerto Rico. To confirm and further investigate these findings, a simple empirical 3-D model of nighttime MSTID bands is constructed. We show ISR and all-sky imager results derived from the model, compare them with the actual observations, and highlight the important findings. This model is intended to replicate both the azimuth-scanning ISR and the all-sky imager results and is especially useful in explaining how these complex structures appear in azimuth-scanning ISR results. In addition, confidence in the empirical model allows us to know what to expect from the theory (of MSTID) and to assess how well geomagnetically quiet, nighttime, midlatitude, F region electrodynamics models succeed. Furthermore, the technique described in the paper is not limited to F region or midlatitudes only; it could be applied to any other phenomenon which can be observed by both radar and imager.
Community Hospitals, Psychiatry and Illness Prevention

The community hospital is a uniquely well suited setting for programs of preventive psychiatry. As an information center as well as a service center, it affords an opportunity for the psychiatrist to come together with other members of the medical community to initiate programs which not only will foster earlier diagnosis and more adequate treatment of psychiatric syndromes, but also will achieve other important goals as well. Whether dealing with children, adults or families, all members of the health profession can establish effective programs to strengthen the individual's ability to cope with predictable stresses, thereby reducing the likelihood of emotional decompensation. For this purpose, changes of attitude and approach are required, within the hospital group and in the relationship between the health profession and the community.