cssi/SciSciGPT-SciSciNet huggingface dataset:
Proton exchange membrane fuel cell cathode contamination – Acetylene

Abstract Acetylene adsorption on PEMFC electrodes and contamination in single cells are investigated with 300 ppm acetylene at a cathode held at 80 °C. The results of adsorption experiments suggest that acetylene adsorbs readily on electrodes and is reduced to ethylene and ethane under an open circuit potential of H 2 /N 2 , as the adsorbates can be electro-oxidized at high potentials. The cell voltage response shows that 300 ppm acetylene results in a cell performance loss of approximately 88%. The voltage degradation curve is divided into two stages by an inflection point, which suggests that potential-dependent processes are involved in acetylene poisoning. These potential-dependent processes may include acetylene oxidation and reduction as well as accumulation of intermediates on the electrode surface. Electrochemical impedance spectroscopy analysis suggests that acetylene affects the oxygen reduction reaction and may also affect mass transport processes. Acetylene also may be reduced in the steady poisoning state of the operating cell. After neat air operation, the cyclic voltammetry results imply that the cathode catalyst surface is almost completely restored, with no contaminant residues remaining in the MEA. Linear scanning voltammetry measurements show no change in hydrogen crossover caused by contamination, and polarization curves confirm complete recovery of cell performance.
Acoustic and optical phonons in nanotubes

The elastic continuum model is applied for single wall nanotubes (SWNTs) and multiple wall nanotube (MWNTs) with the nanotube approximated as an elastic cylindrical membrane of finite thickness. Donnell's equations of motion for a cylindrical membrane are solved using the Rayleigh-Ritz method to give the acoustic vibrational modes of SWNTs. The displacement modes are used to calculate the deformation potential and the dispersion relations are compared for various diameter nanotubes. Results indicate that phonon-bottleneck effects should be important for the short nanotubes being considered for nanotube-based devices exhibiting quasi-ballistic transport.
Cyclic AMP-mediated stimulation by calcium of thymocyte proliferation

Abstract Varying the extracellular calcium concentration between 0 and 1.0 mM does not affect the proliferation of rat thymocytes maintained in vitro. However, higher calcium concentrations raise the level of cell proliferation and increase the intracellular concentration of cyclic AMP. Calcium's mitogenic action is inhibited by imidazole, a compound which increases the activity of the cyclic AMP-degrading enzyme phosphodiesterase and thereby also prevents calcium from increasing the cellular cyclic AMP content. Caffeine, which inhibits phosphodiesterase activity, sensitizes thymocytes to the mitogenic action of calcium. Caffeine can also stimulate thymocyte proliferation by itself and, like calcium, causes a significant rise in the cellular cyclic AMP content. Mitogenic levels of calcium, in turn, act like caffeine and reduce the activity of cyclic AMP-phosphodiesterase. These observations combine to suggest that calcium is the physiological equivalent of caffeine and exerts its effect on thymocyte proliferation by reducing the activity of cyclic AMP-phosphodiesterase.
DANCING, Dance ANd Choreography: an Intelligent Nondeterministic Generator

In this paper, we describe our proof of concept system that uses genetic algorithms to generate choreography for the waltz, a ballroom dance. We detail the representation of the dance steps and sequences our system manipulates, and our design of the fitness function to guide the algorithm. Preliminary results show that we have successfully incorporated several rudimentary choreography principles and that our system thus can generate effective waltz sequences. There are many potential areas of future development for our system, such as extending it to generate more sophisticated choreography for a variety of ballroom dances.
Green Machining of a Thermoplastic Ceramic‐Ethylene Ethyl Acrylate/Isobutyl Methacrylate Compound

The machinability of a thermoplastic compound that consisted of 52 vol% ceramic particles and 48 vol% thermoplastic binders was investigated. To investigate the machining mechanisms, various blends of a ductile polymer (ethylene ethyl acrylate (EEA)) and a brittle polymer (isobutyl methacrylate (IBMA)) were used as thermoplastic binders. The fraction of IBMA to EEA in the blend was increased from 0 to 50 vol%. As the IBMA content was increased, the thermoplastic compound exhibited a stiffer stress versus strain response under compression because of the brittle nature of the IBMA polymer. The machinability of the thermoplastic compound was remarkably improved with increased IBMA content because of the mitigation of the extensive deformation of the thermoplastic compound.
Immunofluorescent cytometry and electron microscopic immunolocalization of insulin-like growth factor (IGF)-II receptors in infant rat choroid plexus

The choroid plexus contains receptors for insulin-like growth factor (IGF)-II, it synthesizes IGF-II, and it secretes soluble IGF binding proteins with high affinity for IGF-II. Although the actions of IGFs in the choroid plexus are unknown, IGFs may participate in CNS growth and differentiation, CNS injury/repair mechanisms, regulation of satiety, and growth hormone secretion. Because the choroid plexus is a heterogeneous tissue containing several cell types, to study the role of IGF-II in the choroid plexus we need to know precisely which cells contain IGF-II receptors. Therefore, we studied the distribution of IGF-II receptors in infant rat choroid plexus by electron microscopic immunohistochemistry and immunofluorescent cytometry of dispersed choroid plexus cells using a well-characterized, highly specific rabbit anti-rat IGF-II receptor antibody. These studies show that IGF-II receptors are detectable in large quantities in both choroid plexus epithelial cells and in the fenestrated capillary endothelial cells. Results were confirmed by immunofluorescent cell sorting using the anti-IGF-II receptor antiserum. Other cell types in the choroid plexus contained lower levels of immunoreactivity, including red blood cells. Physiological studies of IGF-II effects on intact choroid plexus may, therefore, reflect effects on both of these cell populations. These data provide a compelling rationale for the development of choroid plexus epithelial cell lines or pure culture techniques to study the physiology of IGF-II in individual cell types.
D-wave superconductivity in heavy fermion systems

The most favored candidate hybrid state (E18) for superconductivity of UPt3 cannot describe the anisotropy in the upper critical field or the tetracritical point in the magnetic phase diagram. We propose here D-axial state (E2g) as the candidate, since this state is unique among the D-wave superconductors to satisfy Garg's condition necessary to have the tetracritical point in the magnetic phase diagram. In addition we find the D-axial state describes extremely well both the anisotropy of the upper critical field and the thermal conductivity in the vortex state of UPt3.
Somatic Mutational Transients: Models of Response to Acute and Distributed Doses of Radiation Applied to Growing Plants

After limited exposures of whole plants to gamma radiation, the induced-mutation frequency, measured in somatic tissue of successively blooming flowers, is a transient function of time. Quantitative interpretation of the data is aided by construction of a cell-generation model. Seven theoretical models are designed to represent interaction between the cell-generation model and seven different modes of application of the radiation treatment. The models provide a structure for integration of the mutational contributions from different floral primordia. These different contributions are distributed over the array of mature flowers by the quantitative relationships of each model. A mathematical expression for the average response of a model can be equated to the average observed response and solved for the implied mutation rate per cell per roentgen.
Protein and lipid lateral diffusion in normal and Rous sarcoma virus transformed chick embryo fibroblasts.

Abstract We measured the lateral diffusion of the fluorescent lipid analogue dioctadecylindocarbocynanine iodide (DiI) and of membrane glycoproteins labeled with tetramethylrhodamine (TRITC) succinyl concanavalin A (SConA) via fluorescence photobleaching recovery (FPR) at selected times during a temperature downshift experiment on transformation-defective temperature sensitive (td-ts) Rous sarcoma virus (RSV) NY68-transformed chicken embryo fibroblasts (CEF) and on identically treated CEF and RSV-transformed CEF. There were no significant differences in the lateral diffusion of DiI at any of the times measured. The lateral diffusion of TRITC-SConA on the RSV-transformed CEF, (1.32 ± 0.12) · 10−10 cm2 s−1, was approximately two times faster than that observed in normal CEF, (0.61 ± 0.06) · 10−10 cm2 s−1. In the cells undergoing RSV NY68-mediated transformation, TRITC-SConA diffusion increased over a 24-h period from a value comparable to that observed in normal CEF, (0.72 ± 0.13) · 10−10 cm2 s−1 to a value comparable to the RSV-CEF transformed cells, (1.74 ± 0.20) · 10−10 cm2 s−1. All diffusion measurements reported were made at the permissive temperature for RSV-NY68 (35°C) unless stated otherwise. The changes in the lateral diffusion of TRICT-SConA occurred between the fifth and twelfth hour of the downshift course and could be associated with cytoskeletal disruption and/or fibronectin degradation, both known to occur at this time in RSV-transformed cells. To assess the contribution of extracellular matrix (ECM) degradation, SConA mobility was measured in normal and RSV-transformed cells treated with trypsin. This treatment increased SConA mobility approximately 4-fold in the normal cells relative to untreated controls and only 2-fold in the RSV-CEF transformed cells. No significant difference in SConA mobility between trypsinized spherical normal and transformed cells was apparent.
The use of thoracic epidural analgesia in a patient with multiple sclerosis and severe kyphoscoliosis.

c e s a t r d s HE USE OF NEURAXIAL TECHNIQUES in multiple sclerosis has been controversial, although it is now comonly believed to be relatively safe. Anesthesiologists have een cautious in their use because of concern that there could e an exacerbation of the disease, which could occur even as a oincidence. Patients with multiple sclerosis may have exacerations of their symptoms over time, which may occur in an npredictable fashion. To the best of the authors’ knowledge, this is the first eported case of the use of thoracic epidural analgesia (TEA) in patient with multiple sclerosis. Additionally, the patient sufered from severe kyphoscoliosis of the thoracic spine. Kyphocoliosis of the spine is not a contraindication for the placement f an epidural catheter; however it makes its placement potenially more difficult.
Sleep apnea and hypertension.

Sleep-disordered breathing (SDB) and the related clinical syndrome, obstructive sleep apnea (OSA), have for many years been associated with hypertension in clinical reports, but it is only recently that a causal association linking SDB to the development of hypertension has been established, and most clinicians who manage hypertensive patients do not pay much attention to it. In the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (sixth report) (JNC VI), which is the standard guideline for the evaluation of hypertension in the United States, sleep apnea is not mentioned as a possible cause of hypertension (1), and many major textbooks on hypertension also pay no attention to it. In this chapter, we review the physiology of sleep; circulatory changes during sleep; and associations between sleep apnea, hypertension, and obesity. We also discuss the effects of treating OSA, and controlling hypertension and its clinical implications.
Non-invasive timing of gas gun projectiles with light detection and ranging

We have developed a Light Detection and Ranging (LIDAR) diagnostic to track the position of a projectile inside of a gas gun launch tube in real-time. This capability permits the generation of precisely timed trigger pulses useful for triggering high-latency diagnostics such as a flash lamp-pumped laser. An initial feasibility test was performed using a 72 mm bore diameter single-stage gas gun routinely used for dynamic research at Los Alamos. A 655 nm pulsed diode laser operating at a pulse repetition rate of 100 kHz was used to interrogate the position of the moving projectile in real-time. The position of the projectile in the gun barrel was tracked over a distance of ~ 3 meters prior to impact. The position record showed that the projectile moved at a velocity of 489 m/s prior to impacting the target. This velocity was in good agreement with independent measurements of the projectile velocity by photon Doppler velocimetry and timing of the passage of the projectile through optical marker beams positioned at the muzzle of the gun. The time-to-amplitude conversion electronics used enable the LIDAR data to be processed in real-time to generate trigger pulses at preset separations between the projectile and target.
Surface Structure and Plate Tectonics of Afar

Abstract The surface structural elements of Afar are indicative of crustal tension. The dominating feature is intense slicing of the Afar Neogene volcanics by early Pleistocene fault-belts, whose trends are related to those of the three rift systems converging on Afar. This faulting shows that crustal extension affected the whole width of Afar, rather than being confined to oceanic-type, axial zones. Nevertheless, the computed amounts of extension agree well with results of plate analysis of the Afar triple-junction. Refined plate analysis for this region yields data consistent with rotation of the Danakil horst, with inferred presence of cross-rift faults, with longitudinal shearing in eastern Afar, with the apparent asymmetry of spreading in the western Gulf of Aden, and with an early episode of north-south spreading in southernmost Afar. Crustal spreading in Afar seems to be a long-term stop-go phenomenon, initiated at the beginning of the Cainozoic (70 m.y. B.P.). The largest tectonic episode was probably related to the Upper Pliocene-Lower Pleistocene swell uplift of Ethiopia, and the splitting apart of the Danakil and Aisha horsts.
Maternal and peer imprinting in mallard ducklings under experimentally simulated natural social conditions

Previous studies revealed that if socially reared mallard duckling actively follow a stuffed mallard (Anas platyrhynchos) hen, they later show a visual preference for the familiar mallard mallard hen over an unfamiliar redhead (Aythya americana) hen. The present study determined that the experience of actively following the hen is essential to the induction of a visually controlled, species-typical, maternal preference. Domestic mallard ducklings that had not been given the opportunity to follow the mallard hen were “passively” reared in social groups consisting of a stuffed mallard hen and seven same-aged siblings for either 24, 48, or 72 hr after hatching. These birds were largely unresponsive to the hen in a later choice test, even when they were passively exposed to the mallard hen for as long as 72 hr prior to testing. The question arose as to whether passive exposure to the ducklings induced a preference for them that interfered with establishment of maternal imprinting under these simulated natural nest conditions. Results indicated that socially reared ducklings do prefer stuffed ducklings to a stuffed mallard hen in a simultaneous choice test even when the hen is present and vocalizing during social rearing. Further, even ducklings reared individually with the mallard hen were unresponsive to her in the lter choice test. That there is something special about the stimulation provided by ducklings was further demonstrated by the finding that stuffed ducklings were preferred over the mallard hen (1) when the social rearing situation precluded active physical interaction with live ducklings and (2) when reared with inanimate stuffed ducklings. Thus, the ineffectiveness of the stuffed mallard hen in inducing visual imprinting under simulated nesting conditions cannot be attributed to the fact that she was not alive or reciprocally interactive. The present results suggest that mallard ducklings do not become visually imprinted to their hen until after departure from the nest, that the visual component of maternal imprinting likely involves active following subsequent to nest departure, and that early in postnatal development siblings are more visually attractive than is the hen.
TESTS IN HAMSTERS FOR ONCOGENIC QUALITY OF ORDINARY VIRUSES INCLUDING ADENOVIRUS TYPE 7.

SummaryStudies were conducted to measure the in vivo oncogenic potential of a variety of “ordinary” viruses. Adenovirus 1, 2, 7, 12 and 18, influenza A2, parainfluenza 1, 2 and 3, respiratory syncytial, mumps, measles, rhinovirus 11, 23 and 30, poliovirus 3, salivary gland virus, varicella, pneumonia virus of mice, Rous sarcoma, visceral lym-phomatosis and resistance-inducing factor (avian leucosis) viruses were tested for ability to induce tumors in hamsters inoculated when newborn, A majority of animals given adenovirus types 12 or 18 developed tumors. Additionally, a portion of animals which received type 7 adenovirus developed sarcomas. Evidence is presented for the significance of type 7 adenovirus in tumor development. Two animals given Bryan's Rous sarcoma virus also developed sarcomas. None of the animals which received any of the other viruses presented significant evidence for induction of malignancy. Studies of additional viruses are in progress.Addendum: Since the time the present manuscript w...
Independence of inherited susceptibility to spontaneous and primed audiogenic seizures in mice.

The familial distribution of spontaneous and primed audiogenic seizures is independent in Binghamtom HET mice. Spontaneous susceptibility may be attributable to homozygosity forasp (Collins and Fuller). A strong genetic influence on sensitivity to priming is also indicated.
Rapid Detection and Suppression of Mining Equipment Cab Fires

The National Institute for Occupational Safety and Health (NIOSH/PRL) conducted a series of large-scale experiments to evaluate the effectiveness of optical flame detectors, photoelectric smoke detectors, and combined ionization and photoelectric smoke detectors for rapidly detecting mining equipment cab fires. The detector alarm times were then used to trigger the discharge of a fire inerting system inside the cab to suppress cab material fires. This paper discusses the types of fire detectors tested, the experiments that were conducted, and the results that were obtained. Conclusions are that rapid detection of equipment cab fires can be achieved to trigger the discharge of a fire inerting system inside the cab to protect the operator in the cab.
Therapy Response Evaluation with Positron Emission Tomography-Computed Tomography

Positron emission tomography-computed tomography with F-18-fluorodeoxyglucose is widely used for evaluation of therapy response in patients with solid tumors but has not been as readily adopted in clinical trials because of the variability of acquisition and processing protocols and the absence of universal response criteria. Criteria proposed for clinical trials are difficult to apply in clinical practice, and gestalt impression is probably accurate in individual patients, especially with respect to the presence of progressive disease and complete response. Semiquantitative methods of determining tissue glucose metabolism, such as standard uptake value, can be a useful descriptor for levels of tissue glucose metabolism and changes in response to therapy if technical quality control measures are carefully maintained. The terms partial response, complete response, and progressive disease are best used in clinical trials in which the terms have specific meanings and precise definitions. In clinical practice, it may be better to use descriptive terminology agreed upon by imaging physicians and clinicians in their own practice.
Coincidences between O VI and O VII Lines: Insights from High-resolution Simulations of the Warm-hot Intergalactic Medium

With high-resolution (0.46 h –1 kpc), large-scale, adaptive mesh-refinement Eulerian cosmological hydrodynamic simulations we compute properties of O VI and O VII absorbers from the warm-hot intergalactic medium (WHIM) at z = 0. Our new simulations are in broad agreement with previous simulations with ~40% of the intergalactic medium being in the WHIM. Our simulations are in agreement with observed properties of O VI absorbers with respect to the line incidence rate and Doppler-width-column-density relation. It is found that the amount of gas in the WHIM below and above 106 K is roughly equal. Strong O VI absorbers are found to be predominantly collisionally ionized. It is found that (61%, 57%, 39%) of O VI absorbers of log N(O VI) cm2 = (12.5-13, 13-14, > 14) have T 1014 cm–2] O VI absorbers on ~100-300 kpc scales are suggested as a potential differentiator between collisional ionization and photoionization models. Quantitative prediction is made for the presence of broad and shallow O VI lines that are largely missed by current observations but will be detectable by Cosmic Origins Spectrograph observations. The reported 3σ upper limit on the mean column density of coincidental O VII lines at the location of detected O VI lines by Yao et al. is above our predicted value by a factor of 2.5-4. The claimed observational detection of O VII lines by Nicastro et al., if true, is 2σ above what our simulations predict.
The effect of LSD on somite number in explanted chick embryos.

L'administration de 10 μg d'acide lysergique diethylamide (LSD-25) aux embryons de poulet en culture n'a pas eu d'effet sur le nombre des somites. Une reduction du nombre des somites a ete observee avec 25 μg de LSD, ce qui confirme notre premiere observation sur la teratogenie de cette drogue. Il semble exister une relation directe entre la dose de LSD et le nombre de paires des somites dans chaque embryon au niveau de 25 et 50 μg.
Solidification of an alloy from a cooled boundary

We Present a mathematical model for the region of dendritic or cellular growth which often forms during the solidification of alloys. The model treats the region of mixed phase (solid and liquid) as a continuum whose properties vary with the local volume fraction of solid. It is assumed that transports of heat and of solute are by diffusion alone, and the model is closed by a condition of marginal equilibrium. Results are obtained for the unidirectional solidification of an alloy from a plane wall. The spatial variations of solid fraction are highly suggestive of the types of morphology that can occur, and a wealth of different structures are found as the physical parameters are varied. Although the model ignores gravity entirely, the results can be applied to the solidification from below of an alloy which is initially less dense than its eutectic. Predictions for the growth rate of the mixed-phase region agree well with existing experimental measurements of ice growing from aqueous salt solutions.
A survey of computational methods for fluid-structure analysis of reactor safety

Abstract The development of computational techniques and computer codes for the analysis of coupled fluid-structure behavior in the field of breeder reactor safety analysis is described. Methods for linear fluid-structure analysis, which are limited to acoustic or small-displacement, incompressible fluids are summarized first. Nonlinear methods have been found necessary for many of the breeder reactor safety problems because large displacements and nonlinear material behavior are encountered. Two problem classes are considered in detail: hypothetical core disruptive accidents, or containment analysis; subassembly analysis. The evolution of codes for these problems is described along with current capabilities and difficulties, and requirements for future developments.
On the asymptotic behavior of a class of nonparametric tests for a change-point problem

Abstract A class of linear rank statistics is considered for testing a sequence of independent random variables with common distribution against alternatives involving a change in distribution at an unknown time point. It is shown that, under the null hypothesis and suitably normalized, this class of statistics converges in distribution to the double exponential extreme value distribution.
pH-dependence of conduction type in cuprous oxide synthesized from solution

Supported by the U.S. Department of Energy, Office of Basic Energy Sciences, and Division of Materials Sciences and Engineering under Award No. DESC0002062.
Patterns of Brachial Arterial Blood Flow in Conscious Human Subjects with and without Cardiac Dysfunction

The patterns of phasic and instantaneous mean brachial arterial blood flow at rest, and during various interventions, were studied in 35 conscious human subjects. Flow was measured with an electromagnetic flowmeter applied to the brachial artery (BA) prior to retrograde arterial catheterization of the left ventricle. The patterns of phasic BA flow in six patients without left-heart disease were compared with those of patients having a variety of cardiac lesions. In three patients with aortic stenosis, a prolonged upslope and a delayed systolic flow peak were noted, while in five patients with severe aortic regurgitation, a progressive decline in flow occurred throughout diastole; retrograde diastolic flow occurred infrequently at end diastole, but was elicited in three patients by inflation of a wrist cuff. Among seven patients with idiopathic hypertrophic subaortic stenosis, those with large pressure gradients across the left ventricular outflow tract exhibited a bifid systolic brachial arterial flow pul...
The use and abuse of the "medical model" as a conceptual frame in psychiatry.

The same conceptual frame frequently has both constructive and destructive potential. The article discusses the current use of the term “the medical model' in the mental health field. It is suggested that at present the term is frequently taken to represent one pole of two opposing and destructive forces in psychiatry; if adequately defined and clarified, however, it may be a valuable and unifying frame upon which the constructive future of psychiatry can rest.
Application of high‐throughput sequencing to measure the performance of commonly used selective cultivation methods for the foodborne pathogen Campylobacter

Campylobacter is an important foodborne human pathogen, which has traditionally been studied using a variety of selective cultivation methods. Here we use next-generation sequencing to ask the following: (i) how selective are commonly used Campylobacter cultivation methods relative to the initial sample and (ii) how do the specificity and sensitivity of these methods compare with one another? To answer these questions, we used 16S rRNA tagged-pyrosequencing to sequence directly from a pooled fecal sample representing a c. 16 000 bird poultry flock and compared these data to exhaustive sequencing of colonies formed after plating. We compared five commonly used media [Cefex, Cape Town, modified cefoperazone charcoal deoxycholate agar (mCCDA), Campy-Line agar (CLA), and Campy-CVA agar (CVA)], two incubation atmospheres (10% CO2, 5% O2, 85% N2 and 10% CO2, 10% H2, 80% N2), and two incubation temperatures (37 and 42 °C). Analysis of 404 104 total sequence reads, including 19 472 total fecal reads, revealed Campylobacter represented only a small proportion (< 0.04%) of sequences present in the feces, but 88–97% of sequences from each media type. Incubation atmosphere had little effect on recovery, but a significant difference in media specificity (more non-CampylobacterOTUs; P = 0.028) was found at 42 vs. 37 °C. The most common non-Campylobacter sequence type was Proteus, which ranged from 0.04% of sequences (mCCDA) to 10.8% (Cape Town). High-throughput sequencing provides a novel and powerful approach to measure the performance of selective media, which remain widely used for research and regulatory purposes.
Factors Affecting the Protein Quality of Yogurt and Acidophilus Milk

Abstract The apparent protein digestibility in vivo, the protein digestibility in vitro, the net protein ratio, and computed protein efficiency ratio were used to assess the protein quality of yogurt and acidophilus milk as affected by heat treatment, direct acidification, addition of culture, or fermentation. Rats fed diets containing either heated mix or yogurt tended to eat more and gain more weight than rats fed diets containing either unheated mix or the acidified yogurt. Feed efficiency was also significantly higher for rats fed heated mix and yogurt. The apparent protein digestibility in vivo was significantly higher in yogurt diet than in the unheated yogurt mix diet. The net protein ratio of the yogurt diet was significantly higher than that of either the unheated mix or the acidified yogurt but not significantly different from the heated mix. The computed protein efficiency ratio values were also increased with both heating and fermentation. The direct acidified yogurt had a significantly lower net protein ratio and lower computed protein efficiency ratio than the fermented yogurt. Rats fed either sweet acidophilus (unfermented) or acidophilus milk exhibited a significantly higher protein digestibility than rats fed heated milk, indicating that the lactic culture may have a direct effect on protein digestibility. Despite their increased protein digestibilities, the acidophilus products did not display any significant increase in net protein ratio or computed protein efficiency ratio.
The variability of unstandardized plaques obtained from single or multiple subjects.

Abstract Direct microscopic and anaerobic viable counts on a non-selective medium were made of unstandardized plaques sampled once from a number of subjects and repetitively from single subjects. The direct counts of 40 plaques had a mean of 24.7 × 10 7 and a range of 16.1–33.0 × 10 7 organisms/mg wet weight of plaque. Viable counts of 33 plaques had a mean of 12.3 × 10 7 and a range of 3.2–27.0 × 10 7 organisms/mg wet weight of plaque. The means and variances of plaques obtained repetitively from single subjects were generally not significantly different from those of plaques obtained from multiple subjects.
Corneal arcus as first sign of familial hypercholesterolemia.

Figure 2. Corneal arcus is separated from the limbus by a thin ring of clear cornea (named “lucid interval of Vogt”). A 4-year-old boy was referred for investigation after his parents noticed the presence of a grayish ring parallel to the limbus of both eyes. His past medical history was unremarkable. His father was affected by familial hypercholesterolemia, which was responsive to statin therapy. The ophthalmologic evaluation described a corneal arcus separated by a 1-mm lucid interval (Figures 1 and 2). Blood exams revealed marked low-density lipoprotein hypercholesterolemia (530 mg/dL), suggesting a diagnosis of familial hypercholesterolemia. Corneal arcus, also named “arcus lipoides” or “arcus corneae,” is a white discoloration of the peripheral cornea near the corneoscleral limbus. There is a thin clear section separating the arcus from the limbus known as the lucid interval of Vogt. Arcus deposits tend to start at 6 and 12 o’clock and fill in until becoming completely circumferential. It develops in association with hyperlipidemia as a result of lipid deposition in the deep corneal stroma and the limbal sclera. Its prevalence increases with age. Corneal arcus should be differentiated from other lipid metabolisms affecting the cornea, such as lecithin-cholesterol acyltransferase deficiency deficiency, “fish eye” disease, or Tangier disease. n
Petroleum Crude Oil Characterization by IMS-MS and FTICR MS

Here, complementary ion mobility/mass spectrometry (IM/MS) and ultrahigh-resolution Fourier transform ion cyclotron resonance (FTICR) MS analyses of light, medium, and heavy petroleum crude oils yielded distributions of the heteroatom-containing hydrocarbons, as well as multiple conformational classes. The IM/MS technique provides unique fingerprints for fast identification of signature conformational/compositional patterns, whereas FTICR MS analysis provides comprehensive heteroatom class distributions. IM/MS and FTICR MS results reveal an increase in compositional complexity in proceeding from light to medium to heavy crude oils. Inspection of the mobility results shows a high structural diversity for the CnHhXY (XY = N1, S1, N1, O1, NS, SO1−2, NO1−2, etc.) series, as well as a shift from planar to more compact three-dimensional structures with increasing mass.
Long term culture of tumour-specific cytotoxic T cells.

MANY investigators have been successful in the maintenance of long term tissue culture of human bone marrow-derived (B) cells. These cell lines have been established from both normal subjects1 and from patients with lymphoproliferative disorders2. In most cases, long term B-cell lines have been shown to harbour the Epstein–Barr virus genome which some investigators feel is required for establishment and maintenance of long-term cultures3. There are fewer reports describing continuous culture of human thymus derived (T) cell lines, and when successful, the lines have only been established from patients with acute lymphocytic leukaemia4. Although these cell lines have been shown to bear surface markers of normal human T lymphocytes, there have been no reports which suggest that they possess the ability to respond to immunologic stimuli or to differentiate into antigen-specific lymphocytes. Cytotoxic murine T cells have been kept in continuous culture only through repetitive mixed-lymphocyte stimulation5. In contrast to long term human lymphocyte lines, these cells proliferated only when stimulated with allogeneic lymphocytes and eventually died after a few weeks in culture. Morgan, Ruscetti and Gallo recently reported a method by which medium conditioned by phytohaemagglutinin-stimulated normal human lymphocytes allowed for the selective long-term growth of normal T cells6. In contrast to the previously mentioned cell lines, the proliferation of these reported T-cell cultures was totally dependent on the presence of an exogenously-produced growth factor supplied by the conditioned medium. In this report we describe an adaptation of this method which allows the long term culture of antigen-selected cytotoxic T cells which continue to demonstrate high levels of syngeneic tumour-specific cytotoxicity after more than 4 months in culture.
Down-regulation of Platelet-derived Growth Factor Receptor Expression during Terminal Differentiation of 3T3-L1 Pre-adipocyte Fibroblasts *

The transcription and expression of platelet-derived growth factor (PDGF) receptors (PDGFRs) is down-regulated as a consequence of entry into the replicative cell cycle (Vaziri, C., and Faller, D. V. (1995) Mol. Cell. Biol. 15, 1244-1253). In this study, we have investigated the expression of PDGFRs during terminal differentiation, a process in which cells exit from the cell cycle. When treated with appropriate hormonal stimuli, 3T3-L1 fibroblasts initiate a differentiation program resulting in conversion to lipid-accumulating, adipocyte-like cells. Pre-adipocytes express amounts of PDGFalphaR and PDGFbetaR mRNA and protein that are similar to levels expressed in other murine 3T3 fibroblasts. In contrast, the expression of both alpha and beta receptor transcripts is greatly reduced in differentiated 3T3-L1 cells. The loss of PDGFR mRNA following induction of differentiation precedes morphological conversion as well as the induction of many adipocyte-specific genes. The amounts of cell surface PDGFR protein diminish in parallel with the mRNA levels during differentiation, as shown by Western blotting and PDGF-binding assays. The reduced expression of PDGFRs does not reflect a general down-regulation of growth factor receptors, as expression of the type 1 FGFR is unaffected by terminal differentiation. The PDGFbetaR promoter drives strong expression of a luciferase reporter gene in pre-adipocytes, but not in differentiated cells, indicating that the decrease in PDGFR expression following induction of differentiation is a transcriptionally regulated event. Decreased PDGFR expression in differentiated cells is associated with impaired biological responsiveness to PDGF, as shown by reduced activation of mitogen-activated protein-kinase following PDGF stimulation, and decreased chemotactic responsiveness to PDGF. Our data suggest that PDGFR down-regulation is an important mechanism for reducing PDGF-responsiveness in terminally differentiated 3T3-L1 cells.
Quantum generalized Langevin equation approach to gas/solid collisions

Abstract The classical generalized Langevin equation (GLE) approach to gas/solid collisions is generalized to quantum scattering. Using Feynman's method of partial path integration, the full gas/solid propagator is reduced to a form in which only the dynamics of the incident atom and the surface oscillator(s) directly struck appear explicitly. Solving this effective dynamical problem in the semiclassical limit yields a stationary phase equation of motion identical in form to the classical GLE. The noise, however, is distributed according to quantum rather than classical statistics. From the GLE a quantum phase can be constructed and an S-matrix computed. The resulting theory is capable of describing inelastic-diffractive scattering which has been seen experimentally by Williams.
The retention of electrolyte during recovery fromsevere dehydration due to diarrhea

Summary Balances of nitrogen, sodium, chloride, potassium, phosphorus, and calcium are reported during recovery from dehydration due to severe diarrhea. The balances are correlated with each other to bring into view the disturbances in composition of the intracellular as well as the extracellular fluids. Diarrhea led to a decrease in extracellular water owing to loss of sodium andchloride in extracellular fluid. In some cases, a large part of the loss of extracellular sodium was explained by transfer of sodium from the extracellular to the intracellular fluids. Such a transfer of sodium explained the acidosis in one case. In other cases, sodium was lost from the intracellular as well as extracellular fluids. Loss of intracellular potassium was a prominent feature of all cases and was equivalent in two cases to about one-fourth of the estimated normal potassium content of the baby. This loss of potassium is in excess of the loss which would be expected from loss of nitrogen. No great disturbance in the relative concentration of intracellular phosphorus was demonstrated. The usual replacement therapy of fasting and the parenteral administration of solutions containing sodium chloride, sodium lactate, and glucose corrected the extracellular concentrations. However, considerable sodium entered the cells in two cases and loss of potassium was aggrevated. Replacement of intracellular potassium was obtained by adding 1 to 2 Gm. of potassium chloride to submaintenance feeding. One observation indicated that replacement of intracellular potassium is not likely to occur if the diarrhea continues and submaintenance milk feedings without added potassium chloride are given. The data indicate that the usual milk mixtures contain sufficient potassium to replenish the tissues if these mixtures can be taken in the amounts necessary for growth. During the period of fasting, retention of intracellular potassium can beproduced by adding potassium chloride to solutions containing sodium chloride and sodium lactate. Such a treatment restores extracellular concentrations and replaces the deficit of potassium in part. Accompanying this replenishment of both intracellular and extracellular electrolyte, the babies looked better than after the usual type of treatment and recovered from attacks of diarrhea that would usually be fatal. The significance of a deficit of potassium is discussed.
Some reliability issues in very large databases

Very large databases are subject to unique reliability problems. The size of these databases and the statistics of device failures necessitate specialized techniques for the management of hardware problems. The article discusses the use of controlled partial redundancy to improve database reliability. Issues in the design of operating system/DBMS interfaces to facilitate high reliability are also considered. We discuss control of continued execution of queries and updates in a degraded environment, and propose ways for a query optimizer/access planner to account for hardware failures or system overload. The article concludes with a discussion of the interaction between developments in disk technology and the viability of very large databases. © 1988 John Wiley & Sons, Inc.
On multimodal distributions

As a sequel to khinchine's definition of unimodality a multimodal distribution function is defined. A characterization for such a distribution is given. The convolution of two such distributions is studied.
Numerical optimization techniques for structural-acoustic design of rectangular panels

Abstract Numerical methods are commonly used to calculate the noise radiation from vibrating structures in order to evaluate the acoustic performance of a particular design. Improvements are then often achieved through trial and error by an experienced designer. While automated numerical optimization techniques are extensively utilized in many fields of structural design, their application to acoustic problems has been limited. In this paper, methods for the design optimization of 'quiet' structures using mathematical programming techniques are investigated. The objective of this fundamental study is to develop effective, general methods for sizing optimization of acoustically radiating structures. The specific design example addressed here is the optimal thickness distribution of isotropic, lightly damped, rectangular, flat plates with clamped edges. Acoustic response to applied point forces is minimized either at a single frequency, or over a wide frequency bandwidth. Radiated sound power is calculated using a discretized Rayleigh integral formulation, in conjunction with a finite element solver (SAPIV) for the solution of the structural problem. The CONMIN optimization program is used. It is shown that the selection of appropriate objective functions and constraints is critical to the success of the optimization process for this multi-disciplinary, computational expensive problem. Potential candidates for objective functions and/or constraints include: total weight, placement of structural natural frequencies, mode shape, mean square velocity, radiation efficiency or total radiated sound power. Several alternative formulations are presented and their effectiveness is compared. It is demonstrated that significant reductions in radiated sound power can be achieved by optimal thickness variation.
Effect of temperature on isotonic twitch of white muscle and predicted maximum swimming speeds of skipjack tuna, Katsuwonus pelamis

Latent period, rise time, contraction time, and half relaxation time from isotonic contractions of isolated white muscle samples from skipjack tuna, Katsuwonus pelamis, were determined at 20°, 27°, and 34° C. These parameters were found to be inversely proportional to temperature (Q10 = 1.47, 1.67, 1.62, and 1.72, respectively). The data show that contraction time and the effect of temperature on contraction time of skipjack tuna white muscle are not unique when compared to other equal-sized teleosts. Based on contraction time, maximum swimming speeds at each muscle temperature were calculated and found not significantly to exceed the maximum speeds of other equal-sized teleosts, when comparisons are made at the same white muscle temperatures
Chidi holographic video system

Holo-Chidi is a holographic video processing system designed at the MIT Media Laboratory for real-time computation of Computer Generated Holograms and the subsequent display of the holograms at video frame rates. It's processing engine is adapted from Chidi which is reconfigurable multimedia processing system used for real-time synthesis and analysis of digital video frames. Holo-Chidi is made of two main components: the sets of Chidi processor cards and the display video concentrator card. The processor cards are used for hologram computation while the display video concentrator card acts as frame buffer for the system. The display video concentrator also formats the computed holographic data and converts them to analog form for feeding the acousto-optic modulators of the Media Lab's Mark-II holographic display system. The display video concentrator card can display the computed holograms from the Chidi cards loaded from its high-speed I/O interface port or precomputed holograms loaded from a PC through the United Serial Bus port of its communications processor at above video refresh rates. This paper discusses the design of the display video concentrator used to display holographic video in the Mark-II system.
Parallel structural optimization applied to bone remodeling on distributed memory machines

This paper demonstrates parallel structural optimization methods on distributed memory MIMD machines. We have restricted ourselves to the simpler case of minimizing a multivariate non-linear function subject to bounds on the independent variables, when the objective function is expensive to evaluate as compared to the linear algebra portion of the optimization. This is the case in structural applications, when a large three-dimensional finite element mesh is used to model the structure. This paper demonstrates how parallelism can be exploited during the function and gradient computation as well as the optimization iterations. For the finite element analysis, a ''toruswrapped'' skyline solver is used. The reflective Newton method which attempts to reduce the number of iterations at the expense of more linear algebra per iteration is compared with the more conventional active set method. All code is developed for an Intel iPSC/860, but it can be ported to other distributed memory machines. The methods developed are applied to problems in bone remodeling. In the area of biomechanics, optimization models can be used to predict changes in the distribution of material properties in bone due to the presence of an artificial implant. The model we have used minimizes a linear combination of the mass and strain energy in the entire domain subject to bounds on the densities in each finite element. Early results show that the early reflective Newton method can outperform active set methods when a significant number of variables are not active at the minimum. Keywords: structural optimization, parallel finite element analysis
A novel 4,5-dibromooctane-1,8-diol linker for solid-phase oligosaccharide synthesis

Abstract A novel 4,5-dibromooctane-1,8-diol linker was applied to the solid support preparation of a β-(1→6) trisaccharide employing electrophilic activation of thioethyl glycoside building blocks. Debromination of the resin-bound linker-double bond could effectively be carried out by elimination, followed by olefin cross-metathesis revealing the desired trimeric n-pentenyl glycoside. High-resolution Magic Angle Spinning NMR spectroscopy was used as an analytical tool for the monitoring and development of the solid-phase reactions.