cssi/SciSciGPT-SciSciNet huggingface dataset:
Further studies of the properties of cellular convection in a conditionally unstable atmosphere

The problem of convection in an atmosphere which is stable for dry adiabatic descending motion but unstable for saturated ascending motion is analyzed, with a view to the determinations of the preferred areas of the ascending and descending regions and the distributions of the convection currents. Two somewhat different approaches have been formulated, one is based on an integral relation obtained from the governing linearized differential equation while the other is based on the energy integral. It is found that the area of the ascending region tends to decrease while that of the descending region tends to increase with increasing static stability for unsaturated motion, but both of them are finite under all realistic conditions. On the other hand, when the mean lapse-rate is far above the moist-adiabatic lapse-rate, the consideration of the maximum efficiency in the production of available potential energy gives a much larger preferred area ratio, which tends to approach a constant value for every given static stability factor in the descending region. The theory predicts that for large stability factor R ′ 2 (> 100) in the descending region the area ratio A a / A d increases linearly with the ratio R 1 / R ′ 2 of the stability factors whereas for smaller R ′ 2 (< 100) A a / A d increases more slowly. The predicted area ratio of the ascending and descending regions may vary from 1/2 to 1/30 from nearly neutral to normal conditions in the atmosphere, which agree quite closely with that obtained from satellite observations when reasonable values of eddy viscosity and eddy conductivity are assumed. Alternatively, we may also make use of this theory and the observed area ratio to determine the appropriate eddy viscosity coefficient, if the static stability factor in either the ascending or the descending region is known. The nonlinear heat transfer has also been analyzed. DOI: 10.1111/j.2153-3490.1965.tb00204.x
The Spread of Nuclear Weapons and International Conflict Does Experience Matter

This article evaluates whether the length of time states have nuclear weapons influences their behavior and the behavior of opponents in militarized disputes. Using multiple statistical models and illustrative cases, the article shows that, while acquiring nuclear weapons makes states significantly more likely to reciprocate militarized challenges and have their challenges reciprocated, over time, the effect reverses. In contrast to a static understanding of nuclear weapons, this variation in outcomes over time highlights the difficulties presented by nuclear proliferation.
Time and complex numbers in canonical quantum gravity.

It is noted that not only time but also the imaginary unit is absent from the Wheeler-DeWitt equation (WDE), the basic equation of canonical quantum gravity. This leads to a severe problem in an attempt to recover the time-dependent Schrodinger equation from the WDE. It is suggested that the problem will be solved if the WDE is actually complex and not real, as in most models hitherto considered
Optimization Based Design of Thermoelectric Heat Pump Unit of Active Building Envelope Systems

Active Building Envelope (ABE) systems represent a new thermal control technology that actively uses solar energy to compensate for passive heat losses or gains in building envelopes or other enclosures. This paper introduces the first steps in exposing the community to this new technology, and explores an optimization based design strategy for its feasible application. The overall system is discussed, while this paper also gives particular focus to the design of a key constituent component. Namely, the collection of thermoelectric heat pumps; or, the TE unit. The latter becomes an integral part of the generic enclosure, and is a collection of thermoelectric coolers, or heaters. As a critical component of the optimization based design strategy, select computationally inexpensive approximate analytical models of generic TE coolers/heaters (TE Cooler) are developed. The optimization technique is implemented to evaluate different design configurations of the TE unit. The preliminary results indicate that the total input power required to operate the TE unit decreases as the distribution density of the TE coolers increases. In addition, the thermal resistance of the heat sink (attached to the TE cooler) plays a key role in determining the number of TE coolers required. These preliminary findings may have practical implications regarding the implementation of the ABE system.Copyright © 2005 by ASME
Wavelength-dependent measurements of optical-fiber transit time, material dispersion, and attenuation.

A new method for measuring the wavelength dependence of the transit time, material dispersion, and attenuation of an optical fiber is described. The authors inject light from a 4-ns risetime pulsed broad-band flashlamp into various length fibers and record the transmitted signals with a time-resolved spectrograph. Segments of data spanning an approximately 3,000 {angstrom} range are recorded from a single flashlamp pulse. Comparison of data acquired with short and long fibers enables the determination of the transit time and the material dispersion as functions of wavelength dependence for the entire recorded spectrum simultaneously. The wavelength dependent attenuation is also determined from the signal intensities. The method is demonstrated with experiments using a step index 200-{micro}m-diameter SiO{sub 2} fiber. The results agree with the transit time determined from the bulk glass refractive index to within {+-} 0.035% for the visible (4,000--7,200 {angstrom}) spectrum and 0.12% for the ultraviolet (2,650--4,000 {angstrom}) spectrum, and with the attenuation specified by the fiber manufacturer to within {+-} 10%.
Current trends of clinical and genetic characteristics influencing the resource use and the nurse-patient balance in an intensive care setting.

Abstract Purpose To determine the impact of resource use on the nurse/patient ratio in a pediatric intensive care unit (PICU). To examine the longitudinal influence of chronic or genetically influenced diseases on this interrelation. Materials and Methods Overall, 1586 patients admitted to the PICU through various modes of admission during a 5-year period were prospectively studied. Results The mean daily number of bed use increased from 5 to 8.1, leading to a significant skew from the ideal nurse/patient ratio of 1:1, to an overloaded one of 1:3-5. An increasing longitudinal trend of patients with metabolic diseases ( P P P Conclusions The increasing trend of occupation of PICU bed and ventilator days by patients with chronic diseases may be related to the increasing trend of hospitalization of patients with recognized genetic influence. Although this new trend does not influence mortality, it significantly increases resource use and has a large impact on the staffing needs.
Prim-Dijkstra tradeoffs for improved performance-driven routing tree design

Analysis of Elmore delay in distributed RC tree structures shows the influence of both tree cost and tree radius on signal delay in VLSI interconnects. We give new and efficient interconnection tree constructions that smoothly combine the minimum cost and the minimum radius objectives, by combining respectively optimal algorithms due to Prim (1957) and Dijkstra (1959). Previous "shallow-light" techniques are both less direct and less effective: in practice, our methods achieve uniformly superior cost-radius tradeoffs. Timing simulations for a range of IC and MCM interconnect technologies show that our wirelength savings yield reduced signal delays when compared to shallow-light or standard minimum spanning tree and Steiner tree routing. >
On the concentration of radioimmunoassayable FSH circulating in blood throughout human pregnancy.

THE PERIODIC renascence of interest in follicle stimulating activity (FSA) of human chorionic gonadotrophin preparations has recently recurred in consequence to A) recent immunobiologic evaluations of the FSA of HCG (1), and B) a report of relatively high levels of radioimmunoassayable FSH, without variation, in the serum of women throughout pregnancy (2). However, in contrast to the latter reports of Faiman, Ryan et al. (2), Jaffe, Lee and Midgley (3) observed only low levels of radioimmunoassayable serum FSH at the time of inception of pregnancy. Because of the marked discrepancy in results obtained by these 2 groups, each utilizing a different but “specific” radioimmunoassay for human FSH, we have re-evaluated serum FSH levels at the inception of and throughout the entire course of pregnancy, by means of our own radioimmunoassay for human FSH (4). Details of the radioimmunoassay techniques for measurement of LH-HCG and FSH utilized in the present study, and their application to the estimation of serum ...
The biased rectifier amplifier ¿ A pulse magnetic amplifier

THE biased rectifier amplifier (BRA) was developed to provide small, fast and high-gain magnetic amplifiers which operate from power frequencies such as 60 or 400 cycles. They operate from a pulse power supply and use a voltage source, such as a battery, in series with its rectifiers. They provide push-pull output with one core.
Increased afterload aggravates infarct expansion after acute myocardial infarction

Abstract Arter acute transmural myocardial infarction, the heart may undergo major remodeling characterized by thinning and dilation of the infarct zone and overall enlargement of the heart. The effect of increased left ventricular pressure on infarct expansion and the extent to which it alters postinfarction remodeling were studied in a rat model. Rats with either aortic banding or a sham operation and a survival period of 3 weeks were further randomized to sham thoracotomy or left coronary ligafion. Surviving rats were killed 7 days later and the hearts were fixed in diastole for morphologic analysis. Hearts with aortic banding had a mean peak to peak gradient of 20.7 ± 4.9 mm Hg across the aortic band at death and a significantly thicker heart than that of the comparison group without an aortic band. Infarct size, as a percent of total left ventricular mass, at the time of death was less in the group with aortic banding, yet infarct expansion was more marked. However, when original infarct size was estimated taking into account the effects of aortic banding, scar formation, infarct expansion and infarct-induced hypertrophy, it was found to be similar in both infarct groups (45.50 ± 4.2 versus 47.90 ± 3.1%). Infarct expansion, as measured by cavity dilation and infarct thinning, occurred in both infarct groups but was greater in the group with aortic banding. Cavity volume was 121.35 ± 17.3 mm3in the infarct group and 150.72 ± 18.6 mm3in the aortic band/infarct group (p = 0.05) compared with 64.33 ± 8.89 mm3in the sham rats and 65.24 ± 5.54 mm3in the rats with aortic banding alone. Infarcts were also thinner in the rats with an aortic band compared with those without a band (1.09 ± 0.03 versus 1.37 ± 0.09 mm, p = 0.02) and these wall dimensions were significantly thinner than comparable regions in either control group (2.25 ± 0.10 and 2.61 ± 0.12 mm). Thus, chronic increases in afterload caused by aortic banding, sufficient to produce left ventricular hypertrophy, were associated with increased infarct expansion, suggesting that intraventricular cavity pressure is an important determinant of the detrimental shape change that may occur after transmural infarction.
Small-diameter (2 mm) laparoscopy in the evaluation of liver disease ☆ ☆☆

Background: Percutaneous liver biopsy fails to demonstrate cirrhosis in approximately 32% of cases when compared with laparoscopy with liver biopsy. The aim of this study is to determine the usefulness of small-diameter (2 mm) laparoscopes compared with larger laparoscopes. Methods: Patients undergoing diagnostic laparoscopy for various liver diseases were evaluated with small-diameter (2 mm) laparoscopes either alone or in combination with a 5 or 10 mm laparoscope. Results: Twenty patients were enrolled in this study. Small-diameter laparoscopes provided appropriate visualization of the abdominal organs and proper guidance to liver biopsy in 9 cases. In the remaining 11 cases a larger laparoscope was used for the following reasons: short length of the trocar/introducer in a morbidly obese patient (1), liver mass located in the anterosuperior aspect of the liver precluding good visualization with forward lenses (1), and inability to properly visualize the anterosuperior aspect of the liver (9). No complications were noted with the use of the small-diameter laparoscopes alone. Conclusion: There is a need for an oblique-viewing minilaparoscope that allows visualization comparable to the larger laparoscopes.
Preschool Screening: An Examination of the Behavioral and Emotional Screening System Preschool Teacher Form (BESS Preschool)

The preschool years are a critical time to identify and treat early emotional or behavioral problems. Universal screening can be used to identify emotional and behavioral risk in preschoolers and f...
Characterization Of A Liquid Crystal Television Display As A Spatial Light Modulator For Optical Processing

The recent availability of inexpensive, video-addressable liquid crystal displays has generated interest in the use of such devices for optical processing applications. This paper will present some pertinent performance characteristics for a device of this type, the Radio Shack (Tandy Corp.) Pocketvision. Specific characteristics to be considered are screen transmission, linearity, modulation depth, modulation transfer function (MTF), temporal response and optical flatness. Examples of device performance as a coherent and incoherent processing element will be briefly considered.
DNA polymerase alpha activity in mitogen-activated lymphocytes

DNA polymerase alpha isolated from adult-derived lymphocytes was separated into isozyme forms with low (A1) and high (A2) specific activity. In quiescent lymphocytes only A1 was detected, while mitogen-stimulated lymphocytes contained both A1 and A2 enzyme. Polymerase alpha A1, but not A2, interacted with phosphatidylinositol, ATP, and phosphatidylinositol kinase to yield an activated enzyme with increased affinity of binding to DNA. Mitogen-stimulated lymphocytes showed increased enzyme protein and total activity for both A1 and A2, but, when pre-treated with cycloheximide, exhibited an apparent increase in A2 specific activity with no increase in activity for A1 polymerase. These data suggest that mitogen stimulation of lymphocytes increased total DNA polymerase alpha activity by the phosphoinositide-related activation of polymerase alpha A1 to an A2-like form and by initiating de-novo synthesis of polymerase alpha A2.
Isotopic Composition of Strontium in Carbonatites

THE origin of carbonatites has attracted increasing interest in recent years. The problem can be said to hinge on whether or not sedimentary carbonate rocks are involved in the formation of carbonatite. Since in general the strontium-87/strontium-86 ratios of sedimentary carbonate rocks1 differ from those of mafic igneous rocks2 we felt that a study of the 87Sr/86Sr ratios in carbonatites might offer a partial solution to this problem.
Glutaraldehyde fixation used to demonstrate altered properties of outer mitochondrial membranes in polyunsaturated fatty acid (PUFA) supplemented cells

Abstract Strain L fibroblasts which are incapable of synthesizing polyunsaturated fatty acids (PUFA), are particularly suited for demonstrating the effect of phospholipid fatty acid unsaturation on cell membranes: Once exogenous PUFA have been incorporated into phospholipids, these fatty acids are completely retained. By continuously administering PUFA to L fibroblasts grown in the presence of delipidized serum, phosphoglyceride PUFA levels are increased to more than 50%. Altered physical properties of outer mitochondrial membranes of such cells can be demonstrated by a new approach involving glutaraldehyde fixation. With this fixative, myelin figure-like (MF) structures form almost exclusively on outer mitochondrial membranes. Their number per mitochondrion correlates directly with the average number of double bonds/mole of mitochondrial phosphoglyceride fatty acid. MF are rarely associated with rough endoplasmic reticulum and multivesicular bodies. Virtually none are present in control cells. By freeze fracture, MF and areas of outer mitochondrial membrane are free of intramembranous protein particles. These changes are discussed in light of the fact that outer mitochondrial membranes are relatively poor in protein and that the presence of PUFA may alter the packing of phospholipids thus influencing the extent of glutaraldehyde cross-linkage.
Effect of cold-air advection on internal boundary-layer development over warm oceanic currents

Abstract Field experiments have shown that an internal boundary layer (IBL) can develop when the wind blows perpendicularly from the cold-water side of a warm oceanic current to the warmer side. The height of this IBL downwind from the thermal front as computed by an equation originally developed by Venkatram is in excellent agreement with observations.
Cage Dimension, Handling, and Weight Gain

Many investigators report an increased rate of weight gain in the male rat arising from systematic handling performed for various periods during the interval from birth to sexual maturity. Others have found no increase. These experiments have been reviewed by Bovard and Newton (1956), Bovard (1958), and Ader (1959). It is possible that in some cases the non-uniformity of results is due to variation in the variable of cage dimension. As part of a series of studies primarily designed to test the viability of tumorbearing rats as a function of early experience (Newton & Bly, 1958), it was decided to compare the weight gain of early-handled rats caged in large compartments with that of similarly treated rats caged in relatively small compartments. PROCEDURE
PI3K/Akt‐dependent transcriptional regulation and activation of BMP‐2‐Smad signaling by NF‐κB in metastatic prostate cancer cells

BACKGROUND Bone morphogenetic proteins (BMPs) exert osteoinductive effects in prostate cancer (PC) via uncharacterized mechanisms. In this study, we investigated whether the nuclear transcription factor NF-κB, implicated in PC metastasis, is involved in transcriptional regulation and activation of BMP-2 or BMP-4/Smad signaling in PC cells. METHODS NF-κB inhibition was achieved by IκBα super-repressor adenoviral vector and activation was monitored by EMSA and reporter assays. BMP expression and activation was measured by PCR and reporter assays. Promoter binding assay was performed by chromatin immunoprecipitation (ChIP) assay. Smad1/5/8 phosphorylation was measured by Western blot analysis. RESULTS PCR and chimeric BMP-2 and BMP-4 luciferase assays demonstrate that NF-κB confers robust and selective activation of BMP-2 in p65 overexpressing or rhTNF-α-stimulated PC cells. Inhibition of NF-κB significantly reduced transcript levels and autocrine production of BMP-2 by rhTNF-α stimulated C4-2B cells and to a lesser extent by the parental LNCaP cells. Selective inhibition of PI3K/Akt suppressed the NF-κB-induced BMP-2 promoter activity. Furthermore, suppression of NF-κB activation decreased the transcript levels and BMP-2-induced phosphorylation of Smad1/5/8, critical downstream targets of BMP-2 signaling in PC cells. Notably, the activation of BMPRII by BMP-2 is required for modulation of Smad activation by NF-κB in PC cells. Based on ChIP analysis, the transcriptional regulation of BMP-2 gene by NF-κB may be partially attributed to binding to κb site on the BMP-2 promoter. CONCLUSIONS The data suggest that PI3K/Akt-NF-κB axis may promote PC bone metastasis in part by regulating transcription and activation of the BMP-2-Smad signaling cascade in osteotropic PC cells. Prostate 69: 168–180, 2009. © 2008 Wiley–Liss, Inc.
Effecting Change in Periodicals Service: Management Models and a Process

Managing change implies managing the move from one point of stability to another—the “unfreeze, transition, refreeze paradigm.”1 In today's library environment, change is constant and ongoing. The ability to manage change must be built into the system. This paper examines several change models that managers can use and how it applies to a Periodicals Desk staffing change at the University of Memphis. The change process includes defining the changing, creating a common goal, involving the staff, providing an opportunity for feedback, and providing an opportunity to learn and grow.
Dynamics of the pulsed free-electron laser

Abstract Calculations of coherent picosecond pulse propagation in the free-electron laser are presented, based on a theory directly coupling the Maxwell and single-particle equations. Good agreement is obtained with data of the Stanford experiment, such as the power-tuning curve and the electron energy distribution.
Evaluation of the experimental parameters which control electron detachment dissociation, and their effect on the fragmentation efficiency of glycosaminoglycan carbohydrates

Abstract The efficiency of conversion of precursor ions to observable products for electron detachment dissociation (EDD) was measured as a function of the key experimental parameters to determine their optimal values for the Fourier transform mass spectrometry analysis of anionic glycosaminoglycan carbohydrates. These parameters include electron current, electron energy, dispenser cathode heater current, electron beam duration, charge state of the precursor ion, oligomer length, and precursor ion number accumulated in an external radio frequency multipole trap. Precursor conversion is most efficient at an electron current of 15 μA, and decreases at higher and lower values. The conversion of precursor to product ions increases in efficiency as the electron pulse duration is increased. Together, these data suggest that a radially repulsive electric field is produced between the electron beam and negative ions during EDD which causes the reaction cross-section to decrease at higher values of electron current (>15 μA). Elevating the heater current of the dispenser cathode increases the electron flux, but also causes ion activation, presumably by blackbody infrared irradiation. An electronic circuit is described that allows the electron current produced by the dispenser cathode to be measured during an EDD or electron capture dissociation (ECD) experiment.
Communicating health information to the public: effectiveness of a newsletter

Following a review of health information campaign issues and research on the efficacy of selected communication channels, this paper reports an investigation of a specific medium--a health information newsletter--including whether and how much of it recipients read, its perceived information value, its impact on self-reported actions, its comparative role as a source of health information, and the extent to which results vary with selected characteristics of recipients who responded to a mail survey (n = 887). Results indicate that the newsletter is read and utilized by most recipients and serves for many as a major source of health information. Moreover, there is evidence of direct and indirect newsletter effects on respondents' self-reported health practices. Findings varied significantly with the sex and health professional status of recipients.
Reduction in circulating T lymphocytes in alcoholic liver disease.

Abstract Peripheral-blood T and B lymphocytes were measured in sixty-three patients with chronic alcoholism. Fourteen patients without clinical evidence of liver disease and seven with only fatty liver had normal proportions and numbers of circulating T cells. By contrast, T cells were significantly reduced in forty-two patients with alcoholic hepatitis and/or cirrhosis. The reduction was greatest in the group with alcoholic hepatitis. No consistent change in B cells was observed. The pronounced decrease in peripheral-blood T cells suggests that there is a basic impairment in cell-mediated immunity in alcoholic liver disease.
Sipp: Schedule-induced pellet pouching in the golden hamster

Three food-deprived male golden hamsters were presented food pellets on a fixed-time 60-sec schedule with free access to water. Water consumption and number of pellets pouched were recorded for each session of six different experimental phases. The hamsters failed to acquire schedule-induced polydipsia under several environmental manipulations. However, all 3 hamsters acquired schedule-induced pellet pouching, which remained stable across all environmental manipulations.
STANDARD GIBBS ENERGIES OF FORMATION OF ZNC2O4.2H2O(S), CDC2O4.3H2O(S), HG2C2O4(S), AND PBC2O4(S) AT 298 K AND 1 BAR

Abstract We test the hypothesis that cycling of some heavy metals in soils and aquifers is affected by equilibrium with oxalate solids. The hypothesis was tested using electrochemical cells that allow us to determine Δ G f ∘[PbC 2 O 4 (s)], Δ G f ∘[CdC 2 O 4 · 3H 2 O(s)], Δ G f ∘[ZnC 2 O 4 · 2H 2 O(s)], and Δ G f ∘[Hg 2 C 2 O 4 (s)] and hence, the solubilities in soil solutions. The approach was stepwise. First, reversible equilibria was achieved using an electrochemical cell: Pb(Hg),2-phase ¦PbC 2 O 4 (s), CaC 2 O 4 · H 2 O(s)¦CaCl 2 (aq,m)¦Hg 2 Cl 2 (s)¦ Hg(1), in order to calculate Δ G f ∘[PbC 2 O 4 (s)] from the relatively well-known value of G f ∘[CaC 2 O 4 · H 2 O(s)]. This value of Δ G f ∘[PbC 2 O 4 (s)] then allowed us to obtain values of Δ G f ∘[CdC 2 O 4 · 3H 2 O(s)], Δ G f ∘[ZnC 2 O 4 · 2H 2 O(s)], and Δ G f ∘[Hg 2 C 2 O 4 (s)] from suitable electrochemical cells. When these values of Δ G f ∘ are incorporated into multicomponent speciation calculations, we find that CdC 2 O 4 · 3H 2 O(s), Hg 2 C 2 O 4 (s), and ZnC 2 O 4 · 2H 2 O(s) are unlikely to form except in highly contaminated soils, or in intercellular environments where the concentration of dissolved oxalate is very high. Of these heavy-metal-oxalate minerals, it is conceivable that the PbC 2 O 4 (s) may reach equilibrium in soil solutions. Although the metal-oxalate solids may precipitate locally in the rhizosphere, these solids would not be in equilibrium with the adjacent soil solution.
Unraveling in Democratically Governed Groups

This essay presents a framework for the analysis of voting processes in interest group organizations. It explores the tension between majority rule and membership maintenance in a group. The major theoretical propositions are that myopic majority rule government can cause instability and a loss of members from the group. The risk of this instability, which is called unraveling, leads to behavioral and institutional solutions that impose nonmedian social choices on the group members. The theory is applied to the founding era of the American Federation of Labor, an important, long-lived organization. It is shown that the most important features of the AFL in this century are best explained by reference to the theory of social choice in voluntary organizations.
Stochastic averaging near a homoclinic orbit with multiplicative noise

We consider a randomly perturbed two-dimensional Hamiltonian dynamical system containing a homoclinic orbit. The noise is multiplicative in the position variable. We prove a result similar to the one of Freidlin and Weber; this result states that as the noise becomes smaller, a graph-valued Markov process characterizes the limiting behavior. Our analysis of the glueing conditions hinges upon a coordinate transformation introduced by Khasminskii and a perturbed test function methodology. We find that the glueing conditions exactly correspond to the solvability of a linear equation involving coupled Neumann-to-Dirichlet operators.
Static and dynamic light scattering from aggregating particles

We use standard hydrodynamic and light scattering theories to calculate the total intensity and dynamic light scattering properties of random aggregates of spherical particles containing up to ten spheres. When the aggregates have dimensions comparable to the wavelength of light, intraaggregate interference effects can dramatically reduce the apparent size of the aggregates. These results could be significant in interpreting DNA condensation, protein polymerization, and other biomolecular aggregation reactions.
The microstructure of laterally seeded silicon-on-oxide

The production of large scale integrated circuits in thin silicon films on insulating substrates is currently of much interest in the electronics industry. One of the most promising techniques of forming this composite structure is by lateral seeding. We have used optical microscopy and transmission electron microscopy to characterize the microstructure of silicon-on-oxide formed by scanning CW laser induced lateral epitaxy. The primary defects are dislocations. Dislocation rearrangement leads to the formation of both small angle boundaries (stable, regular dislocation arrays) and grain boundaries. The grains were found to be misoriented to the direction perpendicular to the film plane by ≤ 4° and to the directions in the plane of the film by ≤ 2°. Internal reflection twins are a common defect. Microtwinning was found to occur at the vertical step caused by the substrate-oxide interface if the substrate to oxide step height was > 120 nm. The microstructure is continuous across successive scan lines. Microstructural defects are found to initiate at the same topographical location in different oxide pads. We propose that this is due to the meeting of two crystallization growth fronts. The liquid silicon between the fronts causes large stresses in this area because of the 9% volume increase during solidification. The defects observed in the bulk may form by a similar mechanism or by dislocation generation at substrate-oxide interface irregularities. The models predict that slower growth leads to improved material quality. This has been observed experimentally.
[125I]diiodofluorescein isothiocyanate: its synthesis and use as a reagent for labeling proteins and cells to high specific radioactivity.

Abstract We have synthesized a radioactive derivative of fluorescein isothiocyanate (PITC) by lactoperoxidase-catalyzed iodination of fluorescein amine using 125 I. The iodinated amine was purified by thin-layer chromatography and converted to the isothiocyanate by reaction with thiophosgene. The product was inferred to be the diiodo derivative of FITC by comparing its absorbance and fluorescence emission spectra with those of known standards. This reagent, [ 125 I]diI-FITC, shares many of the useful features of its congener, FITC. Specifically, it may be used to label under mild conditions of temperature and pH, and it is chemically stable. When erythrocytes were labeled with [ 125 I]diI-FITC, radioactivity was found principally in a major exposed protein of the cell surface, and very little hemoglobin was labeled. [ 125 I]diI-FITC may prove generally useful as a means of labeling proteins and cell surfaces to high specific radioactivity.
High Temperature Nanocomposite Through Engineered Synthesis of Hafnia Nano‐Dispersoids in Hexagonal Mesoporous Silica

In this communication, we show a solution-based synthetic route that yields a dual-phase SiO2-based ceramic–ceramic composite capable of retaining nano-structural features up to very high temperatures. The nanocomposite was produced by self-assembly of mesoporous silica using a non-ionic surfactant, and subsequent infiltration of the mesoporosity with a solution containing a high-temperature metal-oxide-based composition (HfO2). The nanocomposite was consolidated and processed up to 1500°C.
Is there a role for maintenance therapy in acute myeloid leukaemia

Maintenance therapy is not part of current standard treatment for acute myeloid leukaemia (AML). However, in other leukaemias, maintenance therapy is used to prolong responses and increase the cure rate. While maintenance chemotherapy has not been shown to improve outcome in AML, several other maintenance strategies are currently being tested in this disease, including immunotherapy, demethylating agents and targeted therapies. While maintenance chemotherapy does not appear to have a role in AML curative therapy, the novel maintenance strategies currently being tested appear promising and warrant further study.
Eicosanoid Activation of Protein Kinase C ϵ INVOLVEMENT IN GROWTH CONE REPELLENT SIGNALING

Exposure of growing neurons to thrombin or semaphorin 3A stimulates a receptor-mediated signaling cascade that results in collapse of their growth cones. This collapse response necessitates eicosanoid production, as we have shown earlier. The present report investigates whether and which protein kinase C (PKC) isoforms may be activated by such eicosanoids. To examine these questions, we isolated growth cones from fetal rat brain and tested whether thrombin or the eicosanoid, 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE), could activate endogenous growth cone PKC. We show that both thrombin and 12(S)-HETE stimulate the phosphorylation of the myristoylated alanine-rich protein kinase C substrate, an 87-kDa adhesion site protein. Furthermore, we show both with immunoprecipitated and with recombinant PKC that 12(S)-HETE activation is selective for the ϵ isoform and does not require accessory proteins. Last, we demonstrate that PKC activation is necessary for thrombin-induced growth cone collapse. These data indicate that eicosanoid-mediated repellent effects result from the direct and selective activation of PKCϵ and suggest the involvement of myristoylated alanine-rich protein kinase C substrate phosphorylation in growth cone collapse.
A framework for expressing and combining preferences

The advent of the World Wide Web has created an explosion in the available on-line information. As the range of potential choices expand, the time and effort required to sort through them also expands. We propose a formal framework for expressing and combining user preferences to address this problem. Preferences can be used to focus search queries and to order the search results. A preference is expressed by the user for an entity which is described by a set of named fields; each field can take on values from a certain type. The * symbol may be used to match any element of that type. A set of preferences can be combined using a generic combine operator which is instantiated with a value function, thus providing a great deal of flexibility. Same preferences can be combined in more than one way and a combination of preferences yields another preference thus providing the closure property. We demonstrate the power of our framework by illustrating how a currently popular personalization system and a real-life application can be realized as special cases of our framework. We also discuss implementation of the framework in a relational setting.
The born-oppenheimer theory of nuclear rotations and vibrations

Abstract In this paper it is demonstrated that there is a fruitful analogy between nuclear and molecular collective rotations and vibrations. In order to implement this analogy, and to construct the analog of the factorable molecular Born-Oppenheimer trial function, one must transform into a representa- tion, in which the nuclear collective “position” operators and the residual intrinsic operators are diagonal. In this representation, the trial function is assumed factorable. Using projection operator techniques, this trial function can be transformed back into a particle coordinate representation, so that conventional many-body techniques can be used. The collective operators are “chosen” only to the extent needed to identify the “type” of collective process that one intends to describe, by stating their transformation properties under the standard symmetry operations in coordinate-, spin- and isospin space: In the present case, the collective operators form a symmetric, second rank tensor, are isoscalar, and thus describe rotations, and size and quadrupole shape oscillations. A more detailed determination of these operators is based on the dynamical argument of minimal coupling between collective and intrinsic modes of excitation. One then finds that in the harmonic limit, vibrations have frequencies given by RPA type equations, and rotational moments of inertia are determined by self-consistent cranking type prescriptions.
Assembly and Dynamics of Gp59-Gp32-Single-stranded DNA (ssDNA), a DNA Helicase Loading Complex Required for Recombination-dependent Replication in Bacteriophage T4

The Gp59 protein of bacteriophage T4 plays critical roles in recombination-dependent DNA replication and repair by correctly loading the replicative helicase, Gp41, onto recombination intermediates. Previous work demonstrated that Gp59 is required to load helicase onto single-stranded DNA that is saturated with Gp32, the T4 single-stranded DNA (ssDNA)-binding protein. Gp59 and Gp32 bind simultaneously to ssDNA, forming a Gp59-Gp32-ssDNA complex that is a key intermediate in helicase loading. Here we characterize the assembly and dynamics of this helicase loading complex (HLC) through changes in the fluorescent states of Gp32F, a fluorescein-Gp32 conjugate. Results show that HLC formation requires a minimum Gp32-ssDNA cluster size and that Gp59 co-localizes with Gp32-ssDNA clusters in the presence of excess free ssDNA. These and other results indicate that Gp59 targets helicase assembly onto Gp32-ssDNA clusters that form on the displaced strand of D-loops, which suggests a mechanism for the rapid initiation of recombination-dependent DNA replication. Helicase loading at the HLC requires ATP binding (not hydrolysis) by Gp41 and results in local remodeling of Gp32 within the HLC. Subsequent ATPase-driven translocation of Gp41 progressively disrupts Gp32-ssDNA interactions. Evidence suggests that Gp59 from the HLC is recycled to promote multiple rounds of helicase assembly on Gp32-ssDNA, a capability that could be important for the restart of stalled replication forks.
Tunable Homodyne Detection of an Incoming QPSK Data Signal Using Two Fixed Pump Lasers

Homodyne detection is of significant interest in optical communications because it detects both the amplitude and phase information of the incoming data channel. One of the challenges in implementing a homodyne receiver is to recover the phase and frequency of the incoming data and to lock these to the local oscillator. We proposed and demonstrated a tunable homodyne detection scheme using two continuous wave pumps to automatically lock a “local” pump laser to an incoming 20-to-40-Gbaud QPSK data signal. Open eyes are obtained for both in-phase and quadrature components of the signal after ∼200-km transmission over single mode fiber (SMF-28) and dispersion compensation fiber without any carrier recovery. The BER performance of the proposed homodyne detection scheme is also performed with and without transmission.
Atmosphärisches Methan als Treibhausgas

Methan (CH4) gehort neben Wasser(dampf), Kohlendioxid (CO2), Distickstoffmonoxid (Lachgas, N2O), Ozon (O3) und den Fluorchlorkohlenwasserstoffen (FCKW) zu den sog.Treibhausgasen, von denen man mit groser Sicherheit annimmt, das sie durch IR-Absorption die von der Erde ausgehende Warmestrahlung in den Weltraum hemmen. Dieser sog.Treibhauseffekt (d.h. derzusatzliche, uber den naturlichen hinausgehende) ist eng mit derOzonproblematik verknupft (Zunahme des Ozongehalts in der Troposphare, Schwund in der Stratosphare): In diesem Beitrag werden die zu erwartenden Schwierigkeiten bei der Reduktion des Treibhauseffektes als gravierender bezeichnet, da die CO2-Emission eine direkte Folge der vorherrschenden Energienutzung ist (Verbrennung fossiler Brennstoffe, vor allem Erdol und Kohle). Methan (ein Nebenprodukt des biologisch-geologischen Kohlenstoffzyklus, dessen atmospharisches Hauptprodukt CO2 ist) tragtquantitativ weniger als CO2 zum berechnetenzusatzlichen Treibhauseffekt bei, stammt jedoch weitgehend aus naturlichen oder mit derNahrungskette gekoppelten Prozessen. Rasche Losungen zur Emissionsminderung sind hier nicht in Sicht. Methan ist auf Grund seiner langen chemischen Lebensdauer und der tropospharischen Aufenthaltszeit von rd. 10 Jahren gleichmasig in der Troposphare verteilt. In dieser Arbeit werden dienaturlichen sowieanthropogenen Quellen des atmospharischen Methans aus der Literatur zusammengestellt, wobei auch zwischen fossilem und „jungem” Methan (im biologischen Kreislauf mit CO2 gebildetem) unterschieden wird. DieSenken werden dargestellt, von denen die wichtigste der Methanabbau durch OH-Radikale in Troposphare und Stratosphare ist. DieUmwandlungsprodukte des Methans — Formaldehyd, Kohlenmonoxid, Kohlendioxid — werden hinsichtlich ihrer Mitwirkung am Treibhauseffekt behandelt. Da die Methankonzentration steigt, mussen die Quellen starker sein als die Senken. Weiterhin ansteigende Emissionen der Treibhausgase — so die Ansicht der meisten Atmospharenforscher — werden zu einer mittleren Erwarmung der Erdoberflache um einige Grade fuhren.
Guinea Pig Neutrophils Infected with Mycobacterium tuberculosis Produce Cytokines Which Activate Alveolar Macrophages in Noncontact Cultures

The early influx of neutrophils to the site of infection may be an important step in host resistance against Mycobacterium tuberculosis. In this study, we investigated the effect of M. tuberculosis infection on the ability of guinea pig neutrophils to produce interleukin-8 (IL-8; CXCL8) and tumor necrosis factor alpha (TNF-α) and to activate alveolar macrophages. Neutrophils and alveolar macrophages were isolated from naive guinea pigs, cultured together or alone, and infected with virulent M. tuberculosis for 3, 12, and 24 h. IL-8 protein production in cocultures, as measured by using an enzyme-linked immunosorbent assay, was found to be additive at 24 h and significantly greater in M. tuberculosis-infected cocultures than in uninfected cocultures and in cultures of the infected neutrophils or macrophages alone. The IL-8 mRNA levels, determined by real-time reverse transcription-PCR, were elevated at 24 h in infected cocultures and infected cells cultured alone. In order to elucidate the contributions of neutrophils and their soluble mediators to the activation of alveolar macrophages, neutrophils and alveolar macrophages were cultured in a contact-independent manner by using a Transwell insert system. Neutrophils were infected with virulent M. tuberculosis in the upper wells, and alveolar macrophages were cultured in the lower wells. The release of hydrogen peroxide from alveolar macrophages exposed to soluble products from infected neutrophils was significantly increased compared to that from unexposed alveolar macrophages. Significant up-regulation of IL-1β and TNF-α mRNA levels in alveolar macrophages was observed at 24 and 30 h, respectively, compared to those in cells not exposed to soluble neutrophil products. Treatment with anti-guinea pig TNF-α polyclonal antibody completely abolished the response of alveolar macrophages to neutrophil products. This finding suggests that TNF-α produced by infected neutrophils may be involved in the activation of alveolar macrophages and hence may contribute to the containment of M. tuberculosis infection during the early period of infection.
Pulmonary artery agenesis presenting as massive hemoptysis--a case report.

Massive hemoptysis is the expectoration of approximately 600 ml of blood in twenty-four hours. Major causes of massive hemoptysis are tuberculosis, bronchiectasis, pulmonary neoplasm, fungus ball, bronchial adenomas, lung abscess, intrabronchial rupture of an aortic aneurysm, cystic fibrosis, pulmonary infarction, and pulmonary trauma. Other, less common causes include Good-pasture's syndrome, broncholiths, pulmonary varix, A-V malformation, and bleeding disorders. Agenesis of the pulmonary artery usually occurs in association with congenital cardiac anomalies, and isolated unilateral absence of the pulmonary artery is uncommon. About 10% of the patients with pulmonary artery agenesis develop inconsequential hemoptysis, but massive hemoptysis is a very rare complication of this anomaly. The following is a case report of a twenty-nine-year-old man with agenesis of the left pulmonary artery, who presented with massive hemoptysis requiring embolization and, eventually, pneumonectomy.
The Influence of Formal Education on Rule Learning and Attribute Identification in a West African Society

Groups of formally educated and of uneducated rural Kpelle tribesmen and children of Liberia, West Africa were given rule learning and attribute identification problems. On a wide variety of measures, rule learning proved easier than attribute identification for a conjunctive rule but not for a disjunctive rule. Education proved to have no significant effect on rule learning for either a conjunctive or a disjunctive rule. The influence of formal education was restricted to the superior performance of the educated subjects on the conjunctive attribute identification problems. These findings were interpreted as indicating that formal education exerts its influence primarily on the way in which known conceptual rules are used in a testing situation, exerting little (if any) influence on the actual learning of such rules.
Adsorption of carbon monoxide-nitrogen, carbon monoxide-oxygen, and oxygen-nitrogen mixtures on synthetic zeolites

Experimental results for the adsorption of the binary gas mixtures oxygen-nitrogen, oxygen-carbon monoxide and nitrogen-carbon monoxide on two synthetic zeolites are reported. In all of these experiments the temperature was −200°F. and the total pressure was 1 atm. Also reported are the isotherms for the three pure gases on the two zeolites at −200°F. The results indicate that these zeolites have a surface selectivity which is independent of any sieving effect based on the size of the adsorbed molecules. It does not appear that the strong separations obtained can be explained in terms of the van der Waals forces which are generally believed to be dominant in physical adsorption. The available methods of predicting binary adsorption data from the pure gas isotherms have been examined.
Activity and Ranging Patterns of Colobus angolensis ruwenzorii in Nyungwe Forest, Rwanda: Possible Costs of Large Group Size

With group sizes sometimes >300 individuals, the Angolan black-and-white colobus (Colobus angolensis ruwenzorii) population in Nyungwe Forest, Rwanda is an intriguing exception to the tendency for folivores to live in smaller groups than expected relative to body size. Researchers have hypothesized that the unusually high quality of foliage at Nyungwe allows colobus there to avoid intragroup feeding competition, releasing constraints on the formation of large groups (Fimbel et al., 2001). We collected data on the activity and ranging patterns of a >300-member Nyungwe colobus group and compared our results to those from smaller groups in other black-and-white colobus (Colobus spp.) populations. Colobus at Nyungwe spent far more time feeding and moving (62%) and far less time resting (32%) than black-and-white colobus at any other site. The annual home range of the Nyungwe colobus was also many times larger (95% minimum convex polygon: 20.7 km 2 ; 95% fixed kernel: 24.4 km 2 ) than those for other populations. We terminated our research after the group engaged in an unprecedented migration among black-and-white colobus by moving 13 km south of their former range. Our results suggest that intragroup scramble competition may be more intense than originally believed within the large colobus groups at Nyungwe and that long periods of resource renewal may be necessary after a large colobus group passes through an area, thereby potentially helping to explain their wide ranging patterns. We discuss the socioecological convergence between the Nyungwe colobus and Chinese snub-nosed monkeys (Rhinopithecus spp.) and suggest directions for future research on the unique black-and-white colobus population at Nyungwe.