cssi/SciSciGPT-SciSciNet huggingface dataset:
Advances in quantum well heterostructure lasers: strained-layer buried heterostructure lasers by selective-area epitaxy

ABSTRACT Strained-layer InxGaixAs-GaAs-AIyGaiyAs buried heterostructure (BH) quantum well lasers have been fabricated using three-step selective-area atmospheric pressure metalorganic chemical vapor deposition. Selective-area epitaxy is used to produce BH lasers involving only GaAs on GaAs re- growth, eliminating the detrimental effects associated with exposed AlyGai-yAs found in other fabri-cation methods. Additionally, selective-area epitaxy provides in-plane bandgap energy control to fabri-cate BH devices with different wavelengths on the same wafer.1. INTRODUCTIONBuried heterostructure (BH) lasers have been fabricated by a variety of techniques19. The most common method involves1 growing the entire laser structure, forming an active region mesa by wet or dry etching, and regrowing the burying layer. For strained-layer InGaiAs-GaAs-AlGai..As quan-turn well lasers, this method exposes the easily oxidized AlGai..As optical confining layer, and re-quires the subsequent regrowth of AlGaiAs on AlGai..As. It is desirable to fabricate BH laserswithout exposing AIGaiAs and without initiating regrowth with A1GaiAs. This can be accorn-
Response of Intracranial Metastases to Erlotinib Therapy

Brain metastases are a common occurrence in non–small-cell lung cancer (NSCLC). The standard treatment is radiation therapy with or without resection, but chemotherapy is only modestly palliative for recurrence within the brain. We describe a 60-year-old nonsmoking Native American woman who presented with left-sided weakness due to a stage IV adenocarcinoma of the lung with multiple brain metastases. The patient received whole-brain radiotherapy (33 Gy in 11 fractions) with resolution of her symptoms, but deferred subsequent chemotherapy. Within 3 months, she became symptomatic again with vertigo, anorexia, and a decrease in her performance
Combat-related posttraumatic stress disorder in a nonpsychiatric population

Abstract Forty Vietnam-era combat veterans who were not currently, and had a largely negative history for, seeking psychiatric or psychological attention for posttraumatic stress disorder (PTSD) were diagnosed using DSM-III criteria. Twenty of the veterans met DSM-III criteria for posttraumatic stress disorder (PTSD) and these subjects were compared with the remainder of the sample. Subjects completed structured interviews concerning premilitary, substance abuse, homecoming variables, and the Minnesota Multiphasic Personality Inventory (MMPI). Results showed that the PTSD positive veterans reported a greater degree of substance abuse while in Vietnam. It was also suggested that a greater number of negative homecoming experiences characterized the PTSD-positive group. Specifically, this group reported a greater amount of cynicism, alienation, physical neglect, and demeaning experiences during the first six months following homecoming. The two groups did not differ on selected premilitary adjustment variables or attitudes toward the war. Results from the MMPI support its utility in assessing PTSD with a nonpsychiatric population. Results are discussed in relation to etiology and directions for future research.
Applications of parsing theory to computer-assisted instruction

Abstract Applications of an LR-1 parsing algorithm to intelligent programs for computer-assisted instruction (CAI) in symbolic logic and foreign languages are discussed. Both applications are for stand-alone CAI courses in regular use by students at Stanford University and other institutions. In the application to symbolic logic, the parser is an input recognizer for formulas. In the application to foreign languages the parser is used both to analyze student input and to generate grammatical pattern drill exercises; in addition the parser will be applied to modelling the student's understanding of the language being taught. The LR-1 system, while recognizing a limited class of forms, has shown itself adequate for diverse instructional applications. The fact that the LR-1 algorithm is implemented in LISP has made development of a powerful semantics especially straightforward.
Experimental study of the effect of a small bubble at the nose of a larger bubble in a Hele-Shaw cell

The effect of a small air bubble attached to the nose of a much larger air bubble in a viscous liquid in a Hele-Shaw cell has been studied. The Hele-Shaw cell was tilted to an angle \ensuremath{\alpha}, measured from the horizontal, so that the buoyancy force allowed the bubbles to rise. The larger bubble became elongated to a nearly elliptical shape and its velocity increased above the value for a circular bubble of the same area. For a given size of main bubble, as the size of the nose bubble decreased, the aspect ratio and velocity of the larger bubble increased. The velocity for a given size bubble could be approximated by the theory presented by Maxworthy [J. Fluid Mech. 173, 95 (1986)] for small values of the bubble ellipticity and large values of \ensuremath{\alpha}. At small values of \ensuremath{\alpha}, modification of the bubble drag by gravitational distortion could partially explain the deviation from the simpler theory.
The impact of substance abuse on the course of bipolar disorder

Abstract Background: Substance abuse occurs at high rates in bipolar disorder. The reasons for this co-occurrence are unknown. Alcohol use disorders have been associated with both earlier and later age of onset of bipolar disorder, in part based on the temporal associations of the two conditions. Both drug and alcohol use disorders are associated with impaired outcome of bipolar illness. This influence may involve both direct effects of alcohol or drugs on the initiation of affective symptoms and indirect effects on treatment compliance. To extend these previous findings we examined the temporal associations of substance abuse and affective symptoms in patients with new onset bipolar disorder. Methods: Associations between affective symptoms and alcohol and cannabis use disorder symptoms were evaluated using regression and time-series correlative methods in 50 new-onset bipolar patients. Results: The duration of alcohol abuse during follow-up was associated with the time patients experienced depression. The duration of cannabis abuse was associated with the duration of mania. Several subgroups could be identified with different temporal relationships among these disorders. Conclusions: Although the relationships among substance use and bipolar disorders are complex, systematic study of the courses of the disorders might clarify how these conditions interact longitudinally. As the numbers of subjects in specific subgroups are relatively small in this study, these results should be considered preliminary.
An l-cysteine sulfinic acid-sensitive metabotropic receptor mediates increased cAMP accumulation in hippocampal slices

Abstract The excitatory amino acid (EAA), l -cysteine sulfinic acid (L-CSA), elicited a dose-dependent increase in CAMP accumulation in adult rat hippocampus that was not blocked by ionotropic glutamate receptor antagonists. Therefore, the possibility was examined that L-CSA activates the (1S,3R)-amino-1,3-cyclopentanedicarboxylic acid (1S,3R-ACPD)-sensitive metabotropic glutamate receptor (mGluR) that increases cAMP by potentiating responses elicited by adenosine or other agonists of receptors coupled to adenylate cyclase via Gs. Like 1S,3R-ACPD, L-CSA induced a cAMP response that was inhibited by the adenosine receptor antagonist, 8-para-sulfyltheophylline, and by adenosine deaminase. In contrast to the 1S,3R-ACPD-induced CAMP response, the L-CSA-induced response was not potentiated by the adenosine uptake inhibitor, dipyridamole. Taken together with the previous finding that L-CSA does not potentiate cAMP responses elicited by agonists of receptors that activate Gs, these data suggest that L-CSA increases CAMP accumulation by activating a metabotropic EAA receptor that is different from the 1S,3R-ACPD-sensitive mGluR associated with potentiation of cAMP responses.
Absolute fluence measurement for a prototype neutron radiotherapy source.

An inexpensive recoil‐proton counter telescope has been designed for absolute fluence measurements of a gas‐target neutron source for radiation therapy. The detector has an absolute efficiency of 1.1×10−9 at 20 cm from an isotropic source and is useful for production rates of 109–1013neutrons per second. The telescope consists of a thin hydrogenous irradiator foil and a surface‐barrier detector to count recoil protons within a defined solid angle. The telescope provides n‐γ discrimination as well as discrimination against scatteredneutrons. Initial tests of the counter telescope were performed using the DD reaction employed in development stages of the gas target. A clear separation of full‐energy recoil protons from background and scatteredneutron events was evident in the pulse‐height spectra without the use of coincidence gating techniques.
A messenger RNA for capsid protein isolated from tobacco mosaic virus-infected tissue.

Abstract A low molecular weight virus-related RNA component (LMC) was isolated from extracts of TMV-infected leaf tissue by employing a combination of the techniques of sucrose density gradient sedimentation and polyacrylamide gel electrophoresis. It was found that LMC has an estimated molecular weight of 2.5 × 10 5 and acts as a template for the synthesis of TMV capsid protein in a wheat germ-derived cell-free protein synthesizing system. Evidence is presented for the possible existence of other unique virus-related RNA species in extracts of infected tissue.
Simulation modeling of the effect of climatic factors on bluetongue virus infection in Australian cattle herds. II. Model experimentation

Abstract Using a state transition model based on matrix formulation, the effect of climatic factors on bluetongue virus infection was investigated in a simulated cattle herd in Queensland, Australia. Changes in spring rainfall had the most influence on predicted prevalence of infection, and changes in seasonal minimum temperature had more effect on predicted prevalence than changes in seasonal maximum temperature. Four medium-term (i.e. 25–30 years) climatic scenarios were simulated: warm, wet spring and autumn seasons, and dry, cool spring and autumn seasons. The predicted prevalence of infection was suppressed approximately four-fold when a series of dry, cool autumn seasons were simulated, compared with the other scenarios. Occurrence of dry, cool autumn seasons at least once every 4 years or less had the greatest effect on predicted prevalence of bluetongue virus infection. Results suggest that drought conditions in Australia may affect the endemic stability of bluetongue virus infection. Instability in the system could lead to cyclical epidemics of infection, may explain previously observed variability in bluetongue virus infection, and might lead to outbreaks of bluetongue disease in commercial sheep flocks in Australia.
Aggregate production planning for a continuous reconfigurable manufacturing process

Most of the research on aggregate production planning has been focused on discrete parts manufacturing models. In environments where intermediate inventory cannot be stored, and multiple products are produced simultaneously using complex configurations of production machines, these models may produce erroneous results. In this paper, we present a configuration-based formulation for one such manufacturing environment, where production may involve dissimilar machines performing similar operations at different rates and equipment can be connected together to form different production lines. The production process is continuous and no in-process inventory can be kept. We present and compare several heuristics to generate input data to solve the aggregate production-planning problems using the configuration-based formulation. Computational experiments show that large-scale real-world problems we encountered can be solved in reasonable time using our heuristics and commercial optimization software like CPLEX.
An interorganizational network approach to evaluating children's mental health service systems

The coupling of interorganizational theory and social network analysis techniques provides a way of assessing systems of services at the community level for children and youth with severe emotional disturbances.
Effects of dyadic duration on the relationship between leader behavior perceptions and follower outcomes

This research focused on the role of dyadic duration, the amount of time a subordinate has worked for the same supervisor, in leadership dynamics. Specifically, a field study of engineering personnel examined dyadic duration as a moderator of the relationships between supervisory leadership behavior and subordinates' attitudes and behavior. Moderated regression analysis revealed that the length of time a subordinate had served under the same supervisor influenced the relationship between supportive and directive leader behaviors and follower performance. Implications of these findings were discussed, focusing on the exchange process between individual leaders and followers.
Amplified spontaneous emission in Cassegrainian amplifiers

We consider all possible paths for amplified spontaneous emission (ASE) in multipass laser amplifiers using a Cassegrainian telescope geometry. In particular, we study ASE which is reflected back into the medium off the telescope mirrors themselves. These ASE components are unavoidable in this amplifier geometry. We show that there is a component of the ASE which makes approximately double the number of passes through the amplifier as the laser signal makes. We also show that these high order ASE components are also present in amplifiers which are almost Cassegrainian. They cannot be eliminated by changing the ratio of the scraper and hole radii or the separation of the mirrors. It is likely that these ASE components will be more significant in pulsed lasers than cw lasers.
Activation and Processing of Non-anchored Yapsin 1 (Yap3p) *

A C-terminally truncated form of yapsin 1 (yeast aspartic protease 3), the first member of the novel sub-class of aspartic proteases with specificity for basic residues (designated the Yapsins), was overexpressed and purified to apparent homogeneity, yielding approximately 1 microg of yapsin 1/g of wet yeast. N-terminal amino acid analysis of the purified protein confirmed that the propeptide was absent and that the mature enzyme began at Ala68. The mature enzyme was shown to be composed of approximately equimolar amounts of two subunits, designated alpha and beta, that were associated to each other by a disulfide bond. C-terminally truncated proyapsin 1 was also expressed in the baculovirus/Sf9 insect cell expression system and secreted as a zymogen that could be activated upon incubation at an acidic pH with an optimum at approximately 4.0. When expressed without its pro-region, it was localized intracellularly and lacked activity, indicating that the pro-region was required for the correct folding of the enzyme. The activation of proyapsin 1 in vitro exhibited linear kinetics and generated an intermediate form of yapsin 1 or pseudo-yapsin 1.
The Applied Communication Game: A Comment on Muma’s “Communication Game: Dump and Play”

We now have technology available to teach speech and language skills to children. We cannot always expect children to carry over or generalize this training and spontaneously use this "trained language" in communication situations, so we now must develop technology for teaching interpersonal communication skills. This report commented on a model presented by Muma (1975). Illustrations were presented that should help clinicians train more effective interpersonal communication. The applied communication game provides an objective procedure that utilizes the natural consequences in communication situations to improve communication skill in handicapped children.
Operational calibration of Geostationary Operational Environmental Satellite-8 and -9 imagers and sounders

We describe the operational in-orbit calibration of the Geostationary Operational Environmental Satellite (GOES)-8 and-9 imagers and sounders. In the infrared channels the calibration is based on observations of space and an onboard blackbody. The calibration equation expresses radiance as a quadratic in instrument output. To suppress noise in the blackbody sequences, we filter the calibration slopes. The calibration equation also accounts for an unwanted variation of the reflectances of the instruments' scan mirrors with east-west scan position, which was not discovered until the instruments were in orbit. The visible channels are not calibrated, but the observations are provided relative to the level of space and are normalized to minimize east-west striping in the images. Users receive scaled radiances in a GOES variable format (GVAR) data stream. We describe the procedure users can apply to transform GVAR counts into radiances, temperatures, and mode-A counts.
C14O2 excretion after the intravenous administration of albumin-bound palmitate-1-C14 to intact rats

Sodium palmitate-1-C14 was administered intravenously to rats in the form of the serum albumin-bound complex ion. Expired air collections indicated a rapid and efficient conversion of this substrate to carbon dioxide in fasting rats, whereas rats fed carbohydrate before the isotope was administered excreted only minimal amounts of the label in the same period.
Synthesis of 11C-labeled citalopram, a selective serotonin uptake inhibitor

Abstract A procedure for labeling the novel serotonin uptake inhibitor, citalopram [1-(3-(dimethylamino) propyl-1-(p-fluorophenyl)-5-phthalancarbonitrile, Lu 10-171], with the positron emitting radionuclide11C (t 1 2 = 20.4 min ) has been developed, in order to permit the pharmacokinetics of this compound to be studied in man. The procedure involves the reaction of [11C]iodomethane with desmethylcitalopram in acetone in the presence of sodium hydroxide base at 65° for 8–10 min; this was followed by purification by a column which contained, in series silica gel and basic alumina, and produces no carrier added [11C]citalopram in radiochemical yield (18–66% at EOB) and radiochemical purity (> 95%). The specific activity of [11C]citalopram was 2.52 × 103–16.06 × 103GBq/mmol (68–434 Ci/mmol) at the end of synthesis.
Ultrafiltration behavior of bacterial polysaccharides used in vaccines

Ultrafiltration is widely used for the purification of polysaccharide-based vaccines against pneumococci and meningococci, but there is currently no fundamental understanding of the factors controlling the ultrafiltration behavior of these polysaccharides. Experiments were performed using purified pneumococcus polysaccharides (serotypes Pn3, Pn9V, and Pn14) provided by Pfizer. Ultrafiltration data were obtained in a stirred cell using Ultracel™ composite regenerated cellulose and Biomax™ polyethersulfone membranes with different nominal molecular weight cutoffs. Polysaccharide transmission was a strong function of filtrate flux, with data at low bulk concentrations in good agreement with the classical concentration polarization model. Polysaccharide fouling became significant at high filtrate flux during ultrafiltration of more concentrated solutions, consistent with the presence of a critical value for the wall concentration. Polysaccharide transmission was in good agreement with available hydrodynamic models accounting for the presence of a pore size distribution, with the effective size of the polysaccharide determined by dynamic light scattering or size exclusion chromatography. These results provide important insights into the factors controlling the ultrafiltration behavior of bacterial polysaccharides of interest in bioprocessing applications.
Amiloride-sensitive sodium channel is linked to the cytoskeleton in renal epithelial cells.

Abstract Amiloride-sensitive sodium channels are localized to the microvillar domain of apical membranes in sodium-transporting renal epithelial cells. To elucidate the elements that maintain sodium channel distribution at the apical membrane, we searched for specific proteins associating with the channel. Triton X-100 extraction of A6 epithelial cells reveals that sodium channels are associated with detergent-insoluble and assembled cytoskeleton. Indirect immunofluorescence and confocal microscopy show that sodium channels are segregated to the apical microvillar membrane and colocalize with ankyrin, fodrin, and actin. We document by immunoblot analysis that ankyrin and fodrin remain associated with sodium channels after isolation and purification from bovine renal papillae. 125I-labeled ankyrine can be precipitated by anti-sodium-channel antibodies only in the presence of purified bovine sodium-channel complex. Direct binding of 125I-labeled ankyrin shows ankyrin binds to the 150-kDa subunit of the channel. Fluorescence photobleach lateral-diffusion measurements indicate sodium channels are severely restricted in their lateral mobility. We conclude that ankyrin links the amiloride-sensitive sodium channel to the underlying cytoskeleton and this association may sequester sodium channels at apical microvilli and maintain their polarized distribution in renal epithelial cells.
Delay control in attosecond pump-probe experiments

The time delay between the pump and probe pulses in attosecond time-resolved experiments, such as attosecond streaking, is commonly introduced by splitting and recombining the two pulses in an interferometer. This technique suffers from instability in the optical path lengths of the two arms due to mechanical vibration of the optical elements and fluctuating environmental conditions. We present a technique with which the instability of the unconventional interferometer is suppressed while at the same time the time delay is controlled to within 20 as RMS using a feedback loop. Using this scheme, the streaked spectrogram of an attosecond pulse was measured.
Fatigue in Rheumatologic Diseases

Fatigue is an almost universal patient complaint, yet it is infrequently addressed by the treating physician. A graded exercise program combined with cognitive behavioral therapy and appropriate medications appears to be the most efficacious approach.
Differential expression of genes related to purinergic signaling in smooth muscle cells, PDGFRα‐positive cells, and interstitial cells of Cajal in the murine colon

Background Purinergic signaling provides regulation of colonic motility. Smooth muscle cells (SMC), interstitial cells of Cajal (ICC), and platelet-derived growth factor receptor α-positive (PDGFRα+) cells are electrically coupled and form a functional (SIP) syncytium that constitutes the receptive field for motor neurotransmitters in the tunica muscularis. Each cell type in the SIP syncytium has specialized functions in mediating motor neurotransmission. We compared gene transcripts for purinergic receptors and membrane-bound enzymes for purine degradation expressed by each cell type of the SIP syncytium. Methods Fluorescence-activated cell sorting (FACS) was used to purify SMC, ICC, and PDGFRα+ cells from mixed cell populations of colonic muscles dispersed from reporter strains of mice with constitutive expression of green fluorescent proteins. Differential expression of functional groups of genes related to purinergic signaling was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Key Results We detected marked phenotypic differences among SMC, ICC, and PDGFRα+ cells. Substantial numbers of genes of importance in purinergic neurotransmission were enriched in PDGFRα+ cells in relation to SMC and ICC. Notably, genes related to mediating effects and extracellular biotransformation of enteric purinergic inhibitory neurotransmitters were strongly expressed by PDGFRα+ cells. Conclusions & Inferences Our results demonstrate differential expression of genes for proteins involved in purinergic signaling in the SIP syncytium. These results may further clarify the specific functions of each cell type, identify novel biomarkers for postjunctional cells, and provide hypotheses for further studies to understand the physiological roles of cells of the SIP syncytium.
Georgetown Faculty Grievance

We would like to amplify the ScienceScope item “Georgetown faculty on warpath” (11 Dec. p. 1967). In December 1997, 18 tenured Georgetown University Medical Center faculty filed a grievance against Medical Center Executive Vice President Sam Wiesel and University President Leo O'Donovan for instituting a faculty compensation policy that was enacted at their behest by the board of directors without faculty approval. The grievance asserted that the policy violated the tenure contract with the university as well as the principles of academic freedom and economic security set forth by the university in the Faculty Handbook, a code of conduct and governance developed by the board. The grievance was adjudicated in accordance with the university's grievance code, first by a grievance panel chaired by faculty member Sam Dash, which affirmed the grievants' position and mandated that the plan not be implemented, and second, upon appeal by the administration, by the full university Grievance Code Committee, which also found in favor of the grievants. The last level of appeal was to be to a university executive vice president designated by the president, but he declined to appoint a designee, and therefore, by default, the grievance process ended and the committee's decision was declared final. However, unbeknownst to the committee, the president convened a meeting of several board members to ask that they nullify the committee's decision, prohibit further grievances concerning the policy, and suspend the policy, but not retroactively to 1 July ([1][1]). By taking this extraordinary action, the president and board of directors not only illegally nullified the grievance process but enlarged the scope of the grievance to encompass all tenured faculty at the university's Medical Center, Main Campus, and Law School. Because during the ensuing year, attempts to resolve this issue with the administration have been met with anything but “the spirit of cooperation and collegiality” as has been proclaimed, the grievants have been left with little alternative but to file a lawsuit. It is still hoped that in the best interests of faculty and students alike, the president and board will reconsider their decision to suspend due process and reaffirm the university's obligation to tenured faculty, principles that have been the cornerstone of Georgetown University for 200 years. 1. [↵][2]1. C. Risen , The Hoya , 6 November 1998 ([www.thehoya.com/news/110698/edit.htm][3]); Editorial, ibid . ([www.thehoya.com/editorials/110698/edit1.htm][4]); Viewpoint, ibid . 13 November 1998 ([www.thehoya.com/viewpoint/111398/view1.htm][5]). [1]: #ref-1 [2]: #xref-ref-1-1 "View reference 1 in text" [3]: http://www.thehoya.com/news/110698/edit.htm [4]: http://www.thehoya.com/editorials/110698/edit1.htm [5]: http://www.thehoya.com/viewpoint/111398/view1.htm
Chromosomal Polymorphism as Detected by C‐Banding Patterns in Chilean Alfalfa Germplasm 1

A cytogenetic investigation was conducted on the tetraploid alfalfa [Medicago saliva subsp. saliva (L.) L. & L.] Chilean germplasm source PI 536534 using the combined techniques of C-banding and image analysis. Cluster and multiple correspondence analyses were utilized to compare the C-banding patterns of the Chilean germplasm source and the previously published African germplasm source. Cytogenetic analyses revealed polymorphisms for heterochromatic DNA in the 19 plants observed in detail. Abundant variability in the number, intensity, and location of constitutive heterochromatic DNA was noted; however, this variability was not sufficient to preclude recognition of homologous chromosomes. Five out of the 50 plants studied were aneuploids (2n = 4x + 1 = 33 or 2n = 4x - 1 = 31) because of the presence or absence of a chromosome with a satellite. The Chilean karyotype resembled the reference tetraploid African alfalfa karyotype; however, a reduction in the total amount of heterochromatic DNA was observed. Cluster analysis and multiple correspondence analysis based on all eight alfalfa genome chromosomes yielded no clear separation of Chilean and African germplasms. However, the analysis of C-banding patterns of Homolog 1 of Chromosome 8 in Chilean and African germplasms was effective in separating the two germplasm sources with the exception of two individuals from each germplasm source which clustered together.
The structure and development of the hairpencil glands in males of the queen butterfly, Danaus gilippus berenice

Queen butterflies do not mate until the male has brushed the tufts of his scented, abdominal ”hairpencils„ over the female's head and antennae. The trichogen cells located at the base of each hairpencil are secretory. Presumably, these cells produce the sex pheromone necessary for mating. The liquid secretion must move from a central, microvillus-lined vesicle through the cuticle of the hairs to coat numerous, free, cuticular „dust” particles which adhere to the hairs' surface. The dust carries the secretion to or near the female's antennae. In the pupal stage the dust particles develop as outpocketings of the hair epicuticle. An amorphous matrix, probably protein epicuticle, is deposited in the outpocketings between the cuticulin layer and plasma membrane of the hair. Before the butterfly emerges from the pupa the matrix becomes enclosed by cuticulin, and the particles pinch off from the hair.
A Structural-Acoustic Vehicle System Model for Noise and Vibration Analysis

A structural-acoustic finite-element model of a sedan-type automotive vehicle is developed and experimentally evaluated for predicting vehicle interior noise and structural vibration. The vehicle system model is developed from finite-element models of the major structural subsystems, which include the trimmed body, front suspension, rear suspension, powertrain and exhaust system. An acoustic finite-element model of the passenger compartment cavity is coupled with the vehicle system model to predict the interior noise response. The predicted interior noise and structural vibration by the vehicle system model are compared with the measured responses for shaker excitation at the axle to 200 Hz. The comparisons demonstrate the accuracy of the structural-acoustic vehicle system model, and they indicate where modeling improvements are required.Copyright © 2003 by ASME
Spektrofluorometrische bestimmung von hydrazinen und deren anwendung zur quantitativen bestimmung von benzylhydrazin in biologischen proben

Zusammenfassung Es wird eine fluorimetrische Methode zur Bestimmung stark reduzierender Substanzen wie Hydrazin und Alkylhydrazine beschrieben. Sic beruht auf der Reduktion der 1.2-Naphtochinon-4-sulfonsaure zur fluorescierenden 1,2-Dihydroxy-naphtalin-4-sulfonsaure. Eine Methode zur quantitativen Bestimmung von Mikrogram-Mengen von Hydrazinen in Blutplasma und von Benzylhydrazin in Organen und Urin von Tieren wird angegeben.
Growth of Sr0.61Ba0.39Nb2O6 fibers: new results regarding orientation

The paper describes stable growth of Sr(0.61)Ba(0.39)Nb2O6 (SBN) single-crystal optical fibers (grown by the laser-heated pedestal growth method) along the 100-line and 110-line crystallographic axes. The orientation of SBN fibers was investigated using transmission holograms recorded by focusing two separate, but mutually coherent, optical wavefronts into one end of the fiber. Results showed that the crystal quality of 100-line and 110-line SBN fibers grown at a given pull velocity strongly depended on the fiber diameter; generally, the quality improves with decreasing diameter.
Photoproduction of neutral soliton pairs in trans -(CH ) x

Despite the many successes of the soliton theory of (CH${)}_{x}$, the identity of the defect species responsible for the high-energy peak (\ensuremath{\sim}1.4 eV) in the photoinduced absorption spectrum has remained unexplained, and has provided reason to doubt the validity of the simple independent-electron model on which the theory was based. Here we show that (1) the presence of even weak interactions which break the charge-conjugation symmetry of the continuum model permit the photogeneration of neutral soliton pairs in polyacetylene, (2) these pairs attract to form a bound state which, in the presence of disorder, can be highly metastable, and (3) these pairs provide a natural explanation for the high-energy peak and several other heretofore unexplained experimental observations.
Relations between parent-child affect and synchrony and cognitive outcome at 5 years of age

This investigation involved the longitudinal assessment of 30 preterm and 39 full-term infants from 2 to 5 years of age. Measures of cognitive outcome at 2 and 5 years of age and mother-child dyadic synchrony and affect during free-play interaction were obtained at 5 years of age. Correlational and regression analyses indicated that 5-year cognitive outcome was predicted by 2-year cognitive status, mother education, and 5-year dyadic interaction. In addition, 5-year maternal positive affect contributed independently to children's cognitive status at age 5, above and beyond the contributions of early cognitive status and maternal education. Also, affect and synchrony interacted in predicting lower cognitive abilities. Findings are discussed in relation to the importance of maternal affect and synchronous interactions in transactional explanations of development during early childhood.
DNA Ploidy and proliferation heterogeneity in human prostate cancers

DNA ploidy determinations have been shown to have clinical application in predicting disease progression, survival, or response to anti-androgen therapies in prostate carcinomas. Since intra-tumor heterogeneity may have a profound effect on DNA measurements, we determined the frequency of DNA ploidy and proliferation (here S-phase fraction) heterogeneity in early prostatic carcinomas, and estimated the potential impact of heterogeneity on predicting disease course, survival, or response to therapy. Using image and flow cytometric analysis of archival, paraffin-embedded prostate tumors, we measured DNA ploidy in individual foci of prostatic carcinoma in stage T1a, T1b and T1c disease. Image analysis studies included the use of Feulgen stained tissue sections, and a comparison of these results with flow cytometric DNA ploidy determinations on nuclei isolated from the same tumor foci. Flow cytometry was also used to measure DNA Index and tumor S-phase fraction, in some cases using multiparameter analysis of isolated nuclei to determine DNA content and the level of the proliferation-associated antigen, p105. Our results indicate that DNA aneuploid foci of prostate carcinoma are infrequently seen in stage T1a disease (13% of the individuals studied), and that the presence of both DNA diploid and aneuploid foci in the same sample is seen in less than 10% of these individuals. Stage T1b and T1c tumors containing only DNA diploid nuclei are seen, though these are likely most common in low volume, low Gleason grade tumors. By using flow cytometry to compare these results with those using image analysis of the same tumor foci, we demonstrated that the majority (> 75%) of these aneuploid tumors are DNA tetraploid. Our data on prostate tumor S-phase fractions indicate that DNA diploid tumors generally have a lower S-phase than DNA aneuploid foci (including comparisons of DNA diploid and aneuploid foci in the same prostate tumor). These results support the model that early prostate tumors are DNA diploid and have a low S-phase, and that these tumors likely evolve to DNA tetraploid tumors with a similar low S-phase fraction.
The effect of the intermediate principal stress on fault formation and fault angle in siltstone

Abstract We conducted true triaxial compression tests on specimens prepared from two siltstone core sections, one above and one below the Chelungpu Fault, Taiwan. For different constant σ 2 and σ 3 magnitudes, the maximum principal stress ( σ 1 ) was raised until a post failure stage was reached, and a through-going fault had developed. Despite differences between the properties of the two cores, in all tests peak σ 1 increased as σ 2 was set at higher levels than σ 3 , in contrast to Mohr–Coulomb condition predictions. The fault–normal vector was aligned with the σ 3 direction and made an angle ( θ ) with σ 1 direction. The angle θ , which corresponds to fault dip in case of normal faulting, increased monotonically with σ 2 for fixed σ 3 , a variation that is also inconsistent with Mohr–Coulomb theory. The results of shear band localization theory are used with fault angles observed for axisymmetric compression and deviatoric pure shear to infer properties of the inelastic constitutive behavior. These properties are significantly different for the two cores. Using them to predict θ for other deviatoric stress states yields good agreement with the observations for core II and acceptable agreement for core I. The results are used to predict the angle variation for constant mean normal stress ( θ decreases as the deviatoric stress state varies from axisymmetric extension to axisymmetric compression) and at fixed deviatoric stress state ( θ decreases monotonically with increasing mean normal stress).
Older widows' experience of home care.

Background: Scholars and practitioners have defined home care as a set of services that older persons receive at home. There have been few empirical studies of the essence of the experience. Objectives: To .describe the experience of home care for older widows living alone in their own homes. Findings are reported from one aim of the study, which was to discern the phenomena that were descriptive of the experience of the sample as a whole. Method: A descriptive phenomenological method was used. Participants met inclusion criteria for duration of widowhood, continuing residence in their own homes since the husband's death, number of adult children, self-rated health, and study-specific mental competence. Over a 3-year period, seven tape-recorded interviews were conducted in the homes of 25 widows over the age of 80. Foci of interest were the women's perceptions, actions, and intentions relative to their helpers and the help they had while living alone. The structures of the experience and its context were discerned and detailed in the form of taxonomies of phenomena and contextual features. Results: The common phenomena were sorting out who can best do what needs to be done, protecting my standby, mobilizing my standby to help with this job too, and working together to get the job done. A new definition of home care was proposed, incorporating those phenomena. Discussion: These older widows were not merely receiving home-care services. They were negotiating reliance on their standby helpers in specific ways. As home-care nurses plan care with widows and their other helpers, they should set aside standard definitions of home care that pertain to providing services and focus on the intentions of the older widows whom they serve.
Diffusion-limited exciton-exciton annihilation in single-walled carbon nanotubes: A time-dependent analysis

To provide physical insight into the recently observed photoluminescence saturation behavior in single-walled carbon nanotubes implying the existence of an upper limit of exciton densities, we have performed a time-dependent theoretical study of diffusion-limited exciton-exciton annihilation in the general context of reaction-diffusion processes, for which exact treatments exist. By including the radiative recombination decay as a Poissonian process in the exactly solvable problem of one-dimensional diffusion-driven two-particle annihilation, we were able to correctly model the dynamics of excitons as a function of time with different initial densities, which in turn allowed us to reproduce the experimentally observed photoluminescence saturation behavior at high exciton densities. We also performed Monte Carlo simulations of the purely stochastic, Brownian diffusive motion of one-dimensional excitons, which validated our analytical results. Finally, by considering the diameter, chirality, and temperature dependence of this diffusion-limited exciton-exciton annihilation, we point out that high exciton densities in single-walled carbon nanotubes may be achieved at low temperature in an external magnetic field.
Neoplastic transformation-linked alterations in arginyl-tRNA synthetase activity.

Abstract The behavior of the activity of arginyl-tRNA synthetase ( l -arginine: tRNAArg Ligase(AMP-forming), EC 6.1.1.19) was determined in extracts of rat liver: normal adult, normal proliferating (from developing and from partially hepatectomized rats), and neoplastic (hepatomas of different growth rates) and in extracts of rat kidney cortex and transplantable kidney tumors. The K m values for arginine, ATP, and tRNA of the enzyme of the rapidly growing hepatoma 3924A were the same as those of the enzyme from the liver of control rats. The pH optima of the control and neoplastic livers were in the same range of 7.25–8.0. Taking the hepatic specific activity for arginyl-tRNA synthetase as 100%, deep layer of gut, thymus and testis had higher activity; renal cortex and spleen had the same activity; and skeletal muscle, brain, heart, lung, superficial layer of gut and adipose tissue had lower activity. In a wide spectrum of hepatomas of different growth rates, a significant increase of 1.4–2.4-fold in arginyl-tRNA synthetase activity was observed when compared with that of liver of control normal rats. This elevation in enzyme activity in hepatomas appears to be specific to neoplasia, since it is unaltered in regenerating and low in differentiating liver. The increase in arginyl-tRNA synthetase in the liver tumors appears to be transformation-linked, since the activity was increased in all hepatomas, even in the slowest growing ones. Furthermore, the increase in enzyme activity was not limited to hepatic neoplasms, since a rise was also observed in transplantable rat kidney tumors. Thus, the reprogramming of gene expression in neoplastic tissue entails an increase in arginine-tRNA synthetase activity.
Selection of optimal remission consolidation therapy for individual patients with acute myelogenous leukemia

Abstract Prior to the initiation of remission induction therapy patients with AML a combination of 13-cis retinoic acid and a interferon was administered for 3 days with measurement of the % leukemia cells in S phase prior to and after the administration of these two agents. Patients then received remission induction therapy consisting of idarubicin on days 1, 2, 3 and cytarabine on days 1–7. Patients whose leukemia entered CR [66%] received 3 courses of remission consolidation therapy with courses #s 1 and 3 being identical to remission induction therapy and course #2 consisting of cytarabine 2 gm/m 2 q 12 h on days 1–4. Patients received a combination of retinoic acid and a interferon between each course of remission consolidation therapy. 44% of patients remain in remission at 5 years. 69% of leukemias with intermediate cytogenetic characteristics and with a LI less than the median value prior to the 3 day administration of RA/IFN are in remission at 5 years while the same is the case for 26% of leukemias whose LI was greater than the median value. Considering the post RA/IFN LI, 88% of intermediate cytogenetic leukemias with a LI less than the median value are in remission at 5 years. 76% of leukemias with favorable cytogenetic characteristics are in remission at 5 years. Leukemias with these cytogenetic characteristics have low % cells in S phase. Leukemias with favorable cytogenetic characteristics or with intermediate cytogenetic characteristics and a low % S phase cells constitute 48% of newly diagnosed standard prognosis AML. When treated with the remission consolidation regimen described here these patients have a 76% to 88% likelihood of being in remission beyond 5 years. Studies are underway to determine if a reduction of the LI of cytogenetic intermediate AML whose LI exceeds the median value will result in a prolongation of the remission durations of these patients.
Control of carbon fiber-polypyrrole interphases by aqueous electrochemical process

The morphology, surface free energy and chemical composition of carbon fibers containing polypyrrole interphases has been determined. The morphology of the polypyrrole coated fibers was measured by scanning electron microscopy (SEM). The surface microstructure of the interphases varied from smooth to rough and grainy. The electrolyte used in the formation of polypyrrole interphases has a remarkable influence on the morphology of the resulting coatings. The interphases formed by using toluene sulfonate were either smooth, microspheroidal, leafoidal or rough. The surface morphology of the polypyrrole interphases formed by using duodecyl sulfonate and sulfuric acid are predominantly smooth and rough, respectively. The wettability of the polypyrrole modified carbon fibers was estimated from the surface free energy of the fibers. Significant improvement of the surface free energy of the electrochemically modified fibers (60 < γ ≤75 dynes cm−1) over the commercially surface oxidized fibers (γ = 51 dynes cm−1), of about 40%, was obtained. Examination of the electrochemically formed polypyrrole interphases, by infrared spectrophotometry (IR) showed that the electrolytes were incorporated into the interphases.
Role of Squalene in the Organization of Monolayers Derived from Lipid Extracts of Halobacterium salinarum

We have studied interfacial compressibility and lateral organization in monolayer configurations of total (squalene containing) and polar (squalene-devoid) lipid extracts of Halobacterium salinarum NRC-1, an extremely halophilic archaeon. Pressure–area isotherms derived from Langmuir experiments reveal that packing characteristics and elastic compressibility are strongly influenced by the presence of squalene in the total lipid extract. In conjunction with control experiments using mixtures of DPhPC and squalene, our results establish that the presence of squalene significantly extends elastic area compressibility of total lipid extracts, suggesting it has a role in facilitating tighter packing of archaeal lipid mixtures. Moreover, we find that squalene also influences spatial organization in archaeal membranes. Epifluorescence and atomic force microscopy characterization of Langmuir monolayers transferred onto solid hydrophilic substrates reveal an unusual domain morphology. Individual domains of microsc...