cssi/SciSciGPT-SciSciNet huggingface dataset:
Using the retrospective pretest to get usable, indirect evidence of student learning

Minimal evidence exists regarding the retrospective pretest’s effectiveness as a tool to obtain usable, indirect evidence of student learning in open admissions institutions. The researcher conducted this study to determine if a retrospective pretest more accurately detected a change in students’ knowledge compared to a conventional pretest–posttest. The researcher designed a 17‐item inventory covering course objectives, and students were randomly assigned to either a retrospective pretest (referred to as post‐then) or a conventional pretest–posttest group. Findings indicated that participants in the post‐then group reported a greater change in knowledge compared to the conventional group. This finding supported the use of the retrospective pretest as a tool for getting usable, indirect evidence of student learning. Future research needs to examine response effect, alternative ways of calculating treatment effect and the confounding influences of other perceptual variables.
In Pursuit of a Wild Patience

AbstractThis essay explores how the concept of wild patience informs our practice of teaching and learning in classrooms and in teacher education; how it crafts imaginative spaces in curriculum design, implementation, and evaluation policy and process; and how it can reassure our dreams and hopes for aesthetic education in this generation and in those to come.
Dyadic sampling approximations for non-sequency-limited signals

Dyadic sampling approximations, as well as error estimates, are derived for non-random signals which are Walsh-Stieltjes transforms and for dyadic-stationary and Walsh-harmonizable random signals. Also derived are inversion formulae for Walsh-Stieltjes transforms, which are used in this paper.
A REMEDY FOR HYSTERESIS IN NUCLEATE BOILING THROUGH APPLICATION OF MICROGRAPHITE-FIBER NUCLEATION ACTIVATORS

Porous coated surfaces are found to enhance nucleate-pool-boiling heat transfer performance three- to tenfold compared to plane surfaces. However, with highly wetting liquids, boiling efficiency on porous surfaces usually suffers from thermal hysteresis phenomena at boiling incipience, which constrains engineering applications. The porous surfaces, characterized by a large number of cavities which can be easily flooded by highly wetting liquids, typically have a larger temperature overshoot hysteresis (TOH) than do plane surfaces. In contrast, surfaces made of graphite-copper composite, a kind of nonporous enhanced material, are able to initiate nucleate pool boiling at relatively lower surface superheats. An experimental study of boiling hysteresis phenomena is conducted by boiling pentane under the thermosaturated condition on graphite-copper composite surfaces with graphite fiber concentrations of 25% and 50%, and a pure copper reference surface. The immersion cooling start-up problem in electronic dev...
Enzymatic synthesis of 5-azacytidine 5'-triphosphate from 5-azacytidine

Abstract 5-Azacytidine 5′-monophosphate (5-aza-CMP) was synthesized enzymatically from 5-azacytidine (5-aza-C) in a reaction catalyzed by uridine-cytidine kinase. In a second step, 5-azacytidine 5′-triphosphate (5-aza-CTP) was synthesized enzymatically from 5-aza-CMP using CMP kinase and nucleoside diphosphokinase. Due to the chemical instability of the triazide ring of 5-azacytosine at neutral and alkaline pH, the enzymatic synthesis and purification of the nucleotides by ion exchange chromatography were performed at acid pH. The enzymatically synthesized 5-aza-CTP had an ultraviolet absorbance spectrum at pH 5.5 similar to the spectrum of 5-aza-C. In the DNA-dependent RNA polymerase reaction, 5-aza-CTP inhibited the incorporation of [ 3 H]CTP, but [ 3 H]UTP, into RNA.
Statistical monitoring of multivariable dynamic processes with state-space models

Industrial continuous processes may have a large number of process variables and are usually operated for extended periods at fixed operating points under closed-loop control, yielding process measurements that are autocorrelated, cross-correlated, and collinear. A statistical process monitoring (SPM) method based on multivariate statistics and system theory is introduced to monitor the variability of such processes. The statistical model that describes the in-control variability is based on a canonical-variate (CV) state-space model that is an equivalent representation of a vector autoregressive moving-average time-series model. The CV state variables obtained from the state-space model are linear combinations of the past process measurements that explain the variability of the future measurements the most. Because of this distinctive feature, the CV state variables are regarded as the principal dynamic directions A T2 statistic based on the CV state variables is used for developing an SPM procedure. Simple examples based on simulated data and an experimental application based on a high-temperature short-time milk pasteurization process illustrate advantages of the proposed SPM method.
Interaction Effects of High-Density Lipoprotein Metabolism Gene Variation and Alcohol Consumption on Coronary Heart Disease Risk: The Atherosclerosis Risk in Communities Study

Objective: Light to moderate alcohol consumption has been widely established to be protective against coronary heart disease (CHD), whereas heavy alcohol consumption has been shown to have a potential detrimental effect. The reduction in risk of CHD associated with light and moderate alcohol intake is generally attributed to the beneficial effects of alcohol on high-density lipoprotein (HDL) cholesterol levels. Previous research in the Atherosclerosis Risk in Communities (ARIC) study showed all levels of alcohol consumption to be protective against CHD in whites but to be associated with an increased risk of CHD in black men. We investigated the ARIC cohort to determine whether risk of incident CHD is influenced by an interaction effect between alcohol intake and genetic variation involved in the regulation of HDL cholesterol. Genes of interest included cholesterol ester transfer protein (CETP), lipoprotein lipase (LPL), hepatic lipase (HL), and paraoxonase-1 (PON1). Method: Participants were selected fro...
Mass Spectrometry Characterization of the Thermal Decomposition/Digestion (TDD) at Cysteine in Peptides and Proteins in the Condensed Phase

We report on the characterization by mass spectrometry (MS) of a rapid, reagentless and site-specific cleavage at the N-terminus of the amino acid cysteine (C) in peptides and proteins induced by the thermal decomposition at 220–250 °C for 10 s in solid samples. This thermally induced cleavage at C occurs under the same conditions and simultaneously to our previously reported thermally induced site-specific cleavage at the C-terminus of aspartic acid (D) (Zhang, S.; Basile, F. J. Proteome Res.2007, 6, (5), 1700–1704). The C cleavage proceeds through cleavage of the nitrogen and α–carbon bond (N-terminus) of cysteine and produces modifications at the cleavage site with an amidation (−1 Da) of the N-terminal thermal decomposition product and a −32 Da mass change of the C-terminal thermal decomposition product, the latter yielding either an alanine or β-alanine residue at the N-terminus site. These modifications were confirmed by off-line thermal decomposition electrospray ionization (ESI)-MS, tandem MS (MS/MS) analyses and accurate mass measurements of standard peptides. Molecular oxygen was found to be required for the thermal decomposition and cleavage at C as it induced an initial cysteine thiol side chain oxidation to sulfinic acid. Similar to the thermally induced D cleavage, missed cleavages at C were also observed. The combined thermally induced digestion process at D and C, termed thermal decomposition/digestion (TDD), was observed on several model proteins tested under ambient conditions and the site-specificity of the method confirmed by MS/MS.
The social context of site selection for freshwater fishing.

Abstract Previous research in recreation choice behavior suggests that the social unit of participation is important to recreationists in selecting where they go to participate. This paper focuses on preferences for attributes of angling sites and the role of social unit in those preferences. Based on the type of social unit an individual fished with most often (friends, family, family and friends together, or alone), preferences for 38 site attributes (physical–biological, social, and managerial) were solicited from a sample of 1,232 licensed Texas anglers. Analysis of variance detected significant differences (P < 0.05) on 15 site attributes. Results indicated anglers' preferences for site attributes varied with the social unit they fished with most often. Most differences detected were between anglers who fished alone and anglers who fished with family members. Most differences involved facilities, services, and resources that can be manipulated by managers. Differences were not detected for site attri...
Novice Teachers' Names for Children: Finding a Fit for Educational Foundations Theory and Beliefs about Learners

(1992). Novice Teachers' Names for Children: Finding a Fit for Educational Foundations Theory and Beliefs about Learners. Action in Teacher Education: Vol. 14, No. 2, pp. 23-29.
Finite state induced flow models. I - Two-dimensional thin airfoil

A new finite state aerodynamic theory is presented for incompressible, two-dimensional flow around thin airfoils. The theory is derived directly from potential flow theory with no assumptions on the time history of airfoil motions. The aerodynamic states are the coefficients of a set of induced-flow expansions. As a result, the finite state equations are hierarchical in nature and have closed-form coefficients. Therefore, the model can be taken to as many states as are dictated by the spatial texture and frequency range of interest with no intermediate numerical analysis. The set of first-order state equations is easily coupled with structure and control equations and can be exercised in the frequency or Laplace domain as well as in the time domain. Comparisons are given with Theodorsen theory, Wagner theory, and other methods. Excellent results are found with only a few states.
Distress from lower urinary tract symptoms and its effect on the quality of life in Swedish men

Abstract Background: Lower urinary tract symptoms (LUTS) are common in men and while symptoms have been described as being associated with distress, less attention has been paid to Quality of Life (QoL). The aim of this study was to describe how distress from LUTS affects QoL in men. Methods: The study included 1008, 40–80 year-old, men living in a municipality in Sweden. Participants completed the SF-36 Health Survey and the Danish Prostatic Symptom Score (DAN-PSS). The SF-36 questionnaire measures health status in eight general areas and the DAN-PSS questionnaire measures severity, frequency and distress resulting from LUTS. Results: In all, 63% of the men reported that they experienced some degree of distress related to LUTS. The mean SF-36 scores were significantly lower in all the dimensions evaluated among men who experienced low distress from nocturia, daytime frequency, straining and post micturition dribbling than among men without distress from these symptoms. Furthermore, men with low distress ...
Further evidence for phonological constraints on visual lexical access: TOWED primes FROG

If the phonological codes of visually presented words are assembled-rapidly and automatically for use in lexical access, then words that sound alike should induce similar activity within the internal lexicon.Towed is homophonous with TOAD, which is semantically related tofrog, andbeach is homophonous withbeech, which is semantically related totree. Stimuli such as these were used in a priming-of-namingtask, in which words homophonous with associates of the target words preceded the targets at an onset asynchrony of 100 msec. Relative to spelling controls (trod, bench), the low-frequencytowed and the high-frequencybeach speeded up the naming offrog andtree, respectively, to the same degree. This result was discussed in relation to the accumulating evidence for the primacy of phonological constraints in visual lexical access. nt]mis|This research was supported in part by National Institute of Child Health and Human Development Grants HD-08945 and HD-0 1994 to the first author and Haskins Laboratories, respectively.
Solar Hard X-Ray Bursts and Electron Acceleration Down to 8 keV

In 2 days that were typical of solar maximum (1991 October 1-2), the CGRO/BATSE Spectroscopy Detectors observed more than five solar X-ray bursts per hour above 8 keV [8-13 keV flux greater than 0.4 (cm2 s keV)-1]. Only approximately one-third of these were detected above 25 keV [25-59 keV flux greater than 1.7 × 10-3 (cm2 s keV)-1] by the BATSE Large Area Detectors (LADs). Most of the >8 keV bursts are impulsive and similar to solar hard X-ray bursts observed above 20 keV—the bursts occurred on the most rapid rise of the GOES thermal soft X-ray burst, and the ratio of 8-13 keV to greater than 13 keV flux for the impulsive bursts fitted a power-law spectrum [dJ/d(hν) ~ (hν)-γ] with γ = 3-7. More than half of the bursts that should be detected by the LADs if the power law extends to high energies are not detected, indicating that the spectrum steepens or cuts off above ~25 keV. These findings suggest that the acceleration of electrons occurs for essentially all impulsive energy releases but may only be detectable at low energies in smaller releases. The burst occurrence frequency varies with energy W(>8 keV) in accelerated electrons as dn/dW ~ W-1.6 above W ~ 1029 ergs, with an average rate of energy deposition of ~1026 ergs s-1, about 100 times that above 20 keV. Comparison with the occurrence frequency of the energy content in active region transient brightenings (ARTBs) detected by the Yohkoh soft X-ray telescope suggests that accelerated electrons may provide a significant fraction of the total energy in ARTBs.
Feedback Regulated Drug Delivery Vehicles: Carbon Dioxide Responsive Cationic Hydrogels for Antidote Release

A possible approach to handling the harmful side effects of an analgesic overdose, without losing its therapeutic potential, involves feedback regulated delivery of an antidote. For example, overdose of morphine causes hypoventilation, an inadequate ventilation to perform gas exchanges in lungs leading to increased CO2 concentration in the blood. Taking advantage of CO2 as a toxicity marker, a hydrogel-based delivery vehicle containing dimethylamino groups [poly(N,N-dimethylaminoethyl methacrylate) cross-linked by trimethylolpropane trimethacrylate] was designed. Stimulus controlled swelling of these hydrogels in naloxone delivery is discussed. A remarkable control over naloxone release was achieved against the concentration of the biomarker. The overall stimuli response of the gel could be enhanced further by encapsulating carbonic anhydrase, a metalloenzyme known to catalyze the reversible hydration of CO2. Thus, a feedback regulated drug delivery vehicle based on toxicity biomarker strategy was modeled successfully, which has the potential to mitigate risks associated with drug overdose.
Inversion of multiple thermal indicators: quantitative methods of determining paleoheat flux and geological parameters. II. Theoretical development for chemical, physical, and geological parameters

Using the logic for quantitative inversion of present-day downhole thermal indicators, the inversion procedure can be used to determine unknown, or poorly known, chemical and physical parameters as well as other geological quantities of interest which impact on burial history and thermal history of an evolving sedimentary basin. Some such quantities are: amount of erosion and timing of unconformities, paleo-overpressuring, stratigraphic age, timing of igneous intrusion and insertion temperature, overthrust timing and frictional heating, fault and slump timing, effects due to emplacement of a radiocative layer, and salt emplacement and dissolution timing. Combining a priori unknown values of these chemical/physical and geological parameters with unknown (a priori) paleoheat flux variations, a theoretical scheme, called thermal indicator tomography, is developed for the systematic determination of all parameters at the same time and on the same footing. Case histories will be discussed in subsequent papers in this series.
Theory Versus Experiment for the Rotordynamic Coefficients of Annular Gas Seals: Part 2—Constant-Clearance and Convergent-Tapered Geometry

The leakage and rotordynamic coefficients of constant-clearance and convergent-tapered annular gas seals were measured in an experimental test facility. The results are presented along with the theoretically predicted values. Of particular interest is the prediction that optimally tapered seals have significantly larger direct stiffness than straight seals. The experimental results verify this prediction. Generally the theory does quite well, but fails to predict the large increase in direct stiffness when the fluid is pre-rotated.
Quality of Life assessment in the Collaborative Ocular Melanoma Study: Design and Methods COMS-QOLS Report No. 1

The Collaborative Ocular Melanoma Study (COMS) is a set of randomized clinical trials sponsored by the National Eye Institute of the National Institutes of Health. The COMS is being conducted to evaluate the role of radiotherapy in the treatment of patients with choroidal melanoma. Primary choroidal melanoma can enlarge or metastasize and eventually cause death in a significant percentage of cases. The primary COMS trial is designed to determine whether enucleation (removal of the eye) or radiotherapy without removal of the eye provides the patient with the longest remaining lifespan. More than 40 clinical centers in the United States and Canada are participating in the COMS. The objective of the COMS is to assess the effect of treatment upon 5-year and 10-year survival and the reduction or elimination of the disease process in patients randomly assigned to receive either radiation or enucleation. An ancillary component of the COMS, referred to as the COMS-QOLS, was designed to measure the impact of disea...
Alteration of the blood-brain barrier system by hypothermia: critical time period vs. critical temperature.

Abstract 1. 1. Rats were made hypothermic and were maintained at 16–18, 18–20 or 21–24°C until 1 hr had elapsed from the time at which a temperature of 24°C had been reached. 2. 2. They were then injected with 86RbCl and sacrificed. Brains were removed and counted for radioactivity. 3. 3. Brains from the coldest group showed considerably more radioactivity than those from the warmer groups. 4. 4. It was concluded that permeability of the rat brain to this tracer is determined more by a critical low temperature than by a critical time period in hypothermia.
Factors influencing flip angle mapping in MRI: RF pulse shape, slice‐select gradients, off‐resonance excitation, and B0 inhomogeneities

To understand the various effects that influence actual flip angles, and correct for these effects, it is important to precisely quantify the MRI parameters (such as T1, T2, and perfusion). In this paper actual flip angle maps are calculated using a conventional gradient-echo (GRE) sequence with different radiofrequency (RF) pulse shapes (Gaussian, sinc, and truncated-sinc), slice-selection gradients, off-resonance excitations, and B0 field inhomogeneities. The experimental results demonstrate that RF pulse shapes significantly affect the flip angle distribution and calibration factors. Off-resonance RF excitations, B0 nonuniformities, and slice-selection gradients can lead to degradations in the signal intensities of the images used to map the flip angle, and potentially introduce a bias and increased variance in the measured flip angles.
Analysis of developmentally interesting genes cloned from higher plants by insertional mutagenesis

The ability of transposable elements to generate gene mutations by excising from one site in the genome and reintegrating into new, different sites elsewhere in the genome has led to the development of procedures whereby the elements can be used to tag specific gene sequences for eventual isolation and analysis through gene cloning. This transposon tagging strategy is particularly useful in those situations where limited knowledge of the biochemistry of the target gene precludes gene cloning by conventional strategies. This approach, in conjunction with the more general insertional mutagenesis approach using T-DNA, has led to the cloning and subsequent analysis of several genes from higher plants involved in particular developmental processes. Studies of this nature should eventually shed light on the precise molecular mechanisms utilized to regulate and control cellular differentiation in plants.
WE‐C‐I‐609‐06: Computerized Texture Analysis of Abnormal Areae Gastricae On Double‐Contrast Barium Examinations

Purpose: Abnormal areae gastricae occur in the body due to gastritis. Very frequently, gastritis is caused by the Heliobactor Pylori bacteria, in which case it can be treated with antibiotics. The purpose of this study is to assess the ability of computerized radiographic texture analysis to recognize the presence of abnormal areae gastricae. Potentially, this could aid radiologists in classifying radiographic features of the areae gastricae in pathologic states. Method and Materials: Digitized double‐contrast radiographs for 23 cases were obtained. Each case was classified as normal or abnormal based on clinical symptoms and the results of endoscopic examination, H Pylori testing, and/or barium examination. Similar locations of the gastric area were selected on each image from the lower region of the stomach. These regions were then divided into 64 × 64 and 128 × 128 regions of interest (ROI) for texture analysis. Standard deviation, and Fourier and Fractal based features were calculated for all ROIs. ROC analysis was performed on the results to test the ability to distinguish between normal and gastritic cases, using round‐robin analysis. Results: The texture analysis showed that there is a separation between the normal and abnormal cases. For 64 × 64 ROIs, ROC analysis yielded Az values in a range of 0.54 to 0.80 for single features and a range of 0.70 to 0.806 for multiple features. For 128 × 128 ROIs, single feature ROC analysis yielded Az values in a range of 0.55 to 0.85 for single features and a range of 0.77 to 0.8694 for multiple features. Conclusion: The results indicate that radiographic texture analysis of digitized double‐contrast radiographs have the potential to distinguish between normal and abnormal cases of areae gastricae. Conflict of Interest: ML Giger is a shareholder in R2 Technology, Inc., Sunnyvale, CA.
Classification of abnormal plant operation using multiple process variable trends

Abstract This paper illustrates two strategies for the detection and classification of abnormal process operating conditions in which multiple process variable trends are available. The first strategy uses a hidden Markov model (HMM) for overall process classification while the second method uses a back-propagation neural network (BPNN) to determine the overall process classification. The methods are compared in terms of their ability to detect and correctly diagnose a variety of abnormal operating conditions for a non-isothermal CSTR simulation. For the case study problem, the BPNN method resulted in better classification accuracy with a moderate increase in training time compared with the HMM approach.
Dendritic Cells of the Mouse: Identification and Characterization

We have identified and characterized a distinctive population of dendritic cells (DCs) in mouse spleen, lymph nodes, thyrnus, and liver, Dendritic cells can adhere to tissue culture surfaces but otherwise differ considerably from macrophages, the other major class of adherent cell. Morphological differences are evident by phase contrast and electron microscopy, and by cytochemistry. Dendritic cells exhibit little or no binding and phagocytosis of opsonized particles. During culture, they retain their unusual morphological features and surface markers, but lose the capacity to adhere. All DCs express and synthesize la antigens for several days in vitro , whereas only a subpopulation of mouse macrophages expresses Ia in all organs we have studied. Thus, DCs can be distinguished from macrophages in several independent and stable traits. Highly enriched preparations of the 2 cell types have been obtained. Spleen DCs are derived from bone marrow and are present in nude mice, Dendritic cells do not proliferate, but exhibit a rapid turnover. Other features in their life history are not known. We are studying the contribution of DCs to several immune responses. In all organs we have studied, they are powerful stimulators of the primary mixed leukocyte reaction. B cells, T cells, and macrophages from these organs are weak or inactive, Dendritic cells are potent accessory cells in T cell proliferative responses to mitogens and tuberculin antigens. These dendritic cells and Langerhans cells may belong to a similar lineage, hut to date, Birbeck granules, surface ATPase, and binding of opsonized erythrocytes have not been demonstrated in spleen dendritic cells. However, in functional assays, both DCs and Langerhans cells synthesize La antigens and contribute to transplantation reactions, accessory cell function, and the development of contact sensitivity.
Aqueous RAFT Polymerization of Acrylamide and N,N‐Dimethylacrylamide at Room Temperature

Summary: The first example of a room temperature reversible addition-fragmentation chain transfer polymerization conducted directly in aqueous media is detailed. Under these conditions acrylamide and N,N-dimethylacrylamide may be polymerized in a controlled fashion to near quantitative conversions employing a difunctional trithiocarbonate chain transfer agent (CTA). Hydrolysis studies conducted at pH 5.5 suggest that the CTA is stable up to approximately 50 °C.
“Covering”: How We Missed the Inside-Story of the VLSI Revolution

I'm delighted to comment on Lynn Conway's outstanding piece “Reminiscences of the VLSI Revolution: How a series of failures triggered a paradigm shift in digital design.” What we often forget in engineering and science is that innovation and technological progress happen because of actions of people, people who have personalities, lives, and life stories that influence them and are influenced by those around them. Lynn's story provides a case in point.
Monte Carlo studies of a Micromegas neutron beam monitor

This paper describes a Micromegas neutron detector Monte Carlo simulation that has been developed, and compares its simulated neutron response with published experimental data. The theoretical and experimental results show good agreement, suggesting that the simulation is a reasonable indicator of what may be expected in practice. Modeling of changes in detector-design parameters enabled quantification of the effects of varying neutron target material, neutron-converter foil thickness, drift gap width, and gas pressure on neutron spatial resolution, and the probability of a neutron-absorption event resulting in a count exceeding a lower level discriminator intended to filter out gamma-ray events. The results presented give guidance for selecting optimum Micromegas design parameters for neutron-detection applications.
The governing equations of Moiré interferometry I. The effect of out-of-plane displacement gradients for application to crack-tip fields

Abstract The effects of tilting of the grating plane on moire interferometric fringe patterns are studied using the method of Livnat and Post (Experimental Mechanics, 25(4) (1985) 6–360). Tilting may result either from rigid-body rotations or from out-of-plane displacement gradients. Tilting may introduce a significant error if it is assumed that the fringes represent contours of in-plane displacement, particularly if the in-plane deformation is small compared with the out-of-plane displacement gradient. Knowledge of the surface slope appears to be sufficient to correct the error. It is also shown that the fringe patterns do not capture the added displacement caused by rigid-body rotations exactly. The implications of these effects are briefly discussed for an experiment measuring the deformation at the tip of a crack in a ductile steel, in which the out-of-plane displacement gradients are relatively large.
The 'KMSKS' motif in tyrosyl-tRNA synthetase participates in the initial binding of tRNA(Tyr).

Variants at each position of the ‘KMSKS' signature motif in tyrosyl-tRNA synthetase have been analyzed to test the hypothesis that this motif is involved in catalysis of the second step of the aminoacylation reaction (i.e., the transfer of tyrosine from the enzyme-bound tyrosyl-adenylate intermediate to the tRNATyr substrate). Pre-steady-state kinetic studies show that while the rate constants for tyrosine transfer (k4) are similar to the wild-type value for all of the mobile loop variants, the K230A and K233A variants have increased dissociation constants (KdtRNA= 2.4 and 1.7 μM, respectively) relative to the wild-type enzyme (KdtRNA= 0.39 μM). In contrast, the KdtRNA values for the F231L, G232A, and T234A variants are similar to that of the wild-type enzyme. The KdtRNA value for a loop deletion variant, Δ(227−234), is similar to that for the K230A/K233A double mutant variant (3.4 and 3.0 μM, respectively). Double mutant free energy cycle analysis indicates there is a synergistic interaction between the ...
Effects of synthesis on electrochemical, structural and physical properties of solution phases of Li2MnO3–LiNi1−xCoxO2

Abstract A study of the effect of synthesis techniques and conditions on the electrochemical, structural and physical properties of solution phases of Li 2 MnO 3 and LiNi 1− x Co x O 2 is reported. In this system, the formal oxidation state of the manganese is +4, while that of the nickel and cobalt is +3. These materials were produced from a variety of precursors and chelating agents. Modifications in the synthesis were found to affect the microstructure of the products and their electrochemical performance. It is demonstrated that, with good compositional and microstructural control, solution phases of Li 2 MnO 3 and LiNi 1− x Co x O 2 can have stable discharge capacities as high as 240 mAh g −1 . Furthermore, it has been found that a solution phase of Li 2 MnO 3 and LiNi 1− x Co x O 2 , having no nickel content, Li 1.2 Mn 0.4 Co 0.4 O 2 , can produce very high discharge capacities (∼235 mAh g −1 ) when charged to voltages greater than 4.3 V, despite an apparent theoretical capacity of only 125 mAh g −1 .
Mitochondrial DNA from Drosophila melanogaster.

Abstract Mitochondrial DNA has been isolated from highly purified mitochondria of Drosophila melanogaster embryos. The DNA is circular with a contour length of about 5.5 μm; it renatures with homogeneous and rapid kinetics. Its buoyant density in neutral CsCl is 1.681 g/ml. mtDNA is thereby distinguished from previously reported DNA components of Drosophila . Compared to mtDNAs from other sources, Drosophila mtDNA has an unusually low buoyant density. It is even more strikingly distinguished by its stepwise thermal melting behavior. The thermal transition of both native and renatured mtDNA probably results from pronounced differences in base composition within discrete parts of the genome.
Isolation and partial characterization of the major apolipoprotein component of bovine serum high density lipoprotein.

The delipidated protein component of bovine serum high density lipoprotein was fractionated by gel filtration on a Sephadex G-150 column (equilibrated with buffer containing 6 M urea) into three fractions: I, II and III. Fractions I and II together constitute 88% of all the protein weight of bovine high density lipoprotein, whereas fraction III accounts for the remaining 12%. Analysis of the fractions by sodium dodecyl sulfate-polyacrylamide electrophoresis reveals that fraction I consists mostly of aggregated forms of fraction II and some higher molecular weight species, probably irreversible aggregates of fraction II. The irreversible aggregates are apparently formed during the delipidation procedure or upon aging of the lipoprotein. The major protein component of the high density bovine lipoprotein is found in fraction II; it has a molecular weight of 27 000 ± 1500 and appears to be homogeneous by several physicochemical criteria. The amino acid composition of fractions I and II are essentially identical; their spectral properties, including absorption, fluorescence, and circular dichroism spectra, are similar; however, fraction I appears to contain traces of oxidized lipid and more secondary, α-helical organization than fraction II. By comparison with the intact lipoprotein, which contains about 65% of α-helical structure, fractions I and II have diminished α-helical organization, 55% and 43%, respectively. Fraction III, on sodium dodecyl sulfate-polyacrylamide electrophoresis, separates into two protein bands of equivalent intensity, having molecular weights around 13 000 and 11 000. Fraction III is markedly distinct from the other two, in amino acid composition and spectral properties, especially in its red-shifted fluorescence and very low content of α-helical structure. The protein composition of bovine serum high density lipoprotein is compared with recently published results for high density lipoprotein apoproteins of man, chimpanzee, rhesus monkey, pig and rat. Similarities and differences are discussed in terms of possible evolutionary and functional factors.
Anaerobic glycolysis and repayment of oxygen debt in the alligator.

Abstract 1. 1. Oxygen consumption was determined after intense work periods varying from 10 sec to 270 sec. 2. 2. Exhaustion occurred in 2 min. 3. 3. Lactate was produced during the first 10 sec at a rate severalfold that of the last 10 sec of the 2 min work period. 4. 4. Although the rate of anaerobic glycolysis in the alligator resembled that of the smaller anolis lizard, the rate of repayment of the resulting oxygen debt was inversely proportional to the metabolic rate, requiring 300 min for the 500 g alligator compared to 90 min for the 5 g lizard.
A numerical model for viscous, free-surface, barotropic wind driven ocean circulations

As a first step in investigating the consequences of making the fixed-surface assumption in ocean circulation models, a numerical model for free-surface barotropic flow in a basin on a beta-plane is proposed. Two numerical solutions are presented. The first solution was obtained using a standard linear eddy viscosity (κ = 108 cm2/sec) and it agrees with Gates' solution. The second solution was obtained using a nonlinear eddy viscosity due to Leith and based on two-dimensional turbulence arguments. The two solutions differ in that the nonlinear eddy viscosity permits an intensification of interior flows and a transient modification of the western boundary current.
Faculty Emotional Intelligence and Student-Faculty Interactions: Implications for Student Retention.

This article examines the relationship between student-faculty interactions and student dropout intentions. It develops an integrative model that posits that the association between the frequency o...
Alterations in serum antibody and peripheral T-lymphocyte subsets resulting from treatment of murine immune complex glomerulonephritis with PGE2.

Abstract The effects of treatment with 16,16-dimethyl prostaglandin E 2 (DMPGE 2 ) on histologic damage, glomerular immune complex deposition, serum total IgG subclass levels, anti-apoferritin IgG levels, and peripheral blood T-lymphocyte subsets were determined in apoferritin-induced immune complex glomerulonephritis of mice. The results demonstrate that doses of DMPGE 2 ranging from 2.5 to 10 μg twice daily significantly reduced the degree of glomerular damage in a dose-dependent manner. Similarly, these doses of DMPGE 2 reduced the amount of immunoglobulin deposition along peripheral capillary loops. Total IgM, IgG 1 , IgG 2a , and IgG 2b were unaffected by DMPGE 2 administration. Serum anti-apoferritin IgG levels were significantly reduced in mice receiving DMPGE 2 at doses of 5 and 10 μg twice daily. Nephrotic mice had significantly reduced peripheral blood total T lymphocytes (Lyt-1+) and a reduction of T-suppressor (Lyt-2+) cells. Administration of DMPGE 2 at doses of 5 and 10 μg twice daily prevented these T-lymphocyte alterations. These studies indicate that treatment of mice receiving apoferritin with DMPGE 2 may prevent glomerulonephritis by altering both cellular and humoral immune responses.
The social construction of the breast cancer epidemic

The age-adjusted incidence of breast cancer among U.S. women rose by over 30% during the 1980s. Several population-based studies have concluded that most or all of this observed increase is an artifact of the lead time afforded by mammography screening rather than an indication of a true increase in the rate at which women develop the disease. We conducted a study of the social construction of breast cancer trends as a public health problem in popular U.S. magazines. We documented trends in popular magazine article coverage of breast cancer between 1980 and 1995. In addition, we analyzed the content of a convenience sample of 228 popular magazine articles published between 1987 and 1995, focusing on a subsample of articles (n = 91) that mention the increase in breast cancer incidence. Our results show that the increase in incidence is commonly portrayed as a mysterious, unexplained epidemic occurring primarily among young, professional women in their prime years. Many articles suggest that recent changes in women's behavior such as increases in delayed childbearing, nulliparity, the use of oral contraceptives, induced abortion, and the use of tobacco and alcohol are related to the recent upsurge in the disease. The portrayal of the breast cancer epidemic in the U.S. popular press reflects a strong social desire to create order and control over a frightening disease. In the process, a common message is that the behaviors and choices of young, nontraditional women especially those related to fertility control-have led to pathological repercussions within their bodies, which in turn may be responsible for great disorder and pathology at the societal level in the epidemic of breast cancer.
Natural materials: Velcro mechanics in wood

The remarkable deformability of wood in a moist environment resembles that of ductile metals. A combination of traditional mechanical tests and cutting-edge diffraction experiments reveal the molecular mechanism that determines such behaviour.
The effect of procainamide on T wave alternans.

Procainamide and T-Wave Alternans. Introduction: The measurement of microvolt level T wave alternans (TWA) is a technique for detecting arrhythmia vulnerability. Previous studies demonstrated that the magnitude of TWA is dependent on heart rate. However, the effects of antiarrhythmic drugs on TWA are unknown. Methods and Results: This was a prospective evaluation of intravenous procainamide on TWA in 24 subjects with inducible sustained ventricular tachycardia (VT). Measurements of TWA were performed at baseline in the drug-free state and after procainamide loading (1,204 ± 278 mg). Recordings were made in normal sinus rhythm, and during atrial pacing at 100 heats/min and 120 heats/min. The magnitude of TWA in the vector magnitude lead was decreased by procainamide at all heart rates: 0.6 ± 0.8 to 0.3 ± 0.4 μV in sinus rhythm, 2.0 ± 1.6 to 0.7 ± 0.7 μV at 100 beats/min, and 3.0 ± 2.0 to 1.7 ± 1.8 μV at 120 beats/min (P < 0.001 by analysis of variance). The sensitivity of TWA for the induction of VT at baseline was 5% in sinus, 60% at 100 beats/min, and 87% at 120 beats/min, while it decreased with procainamide to 5%, 19%, and 60%, respectively. Decreases in TWA in response to procainamide were independent of the antiarrhythmic effects on VT inducibility. Conclusions: These results indicate that the magnitude of TWA decreases with acute procainamide loading and this effect decreases the sensitivity of TWA for the induction of sustained VT.
From E′ centers to the ‘characteristic’ resonance: a colleague's reminiscences on the scientific odyssey of Robert A. Weeks

Abstract The scientific career of Professor R.A. Weeks has been an odyssey of some 40 years, carrying him from the Scylla of silica (where he discovered the ‘E′ center’) to the Charybdis of lunar science (where he confronted the riddle of the ‘characteristic’ resonance) and back once again to silica. This paper touches upon but a few episodes in his fantastic voyage, these selected from the perspective of a colleague and occasional shipmate.
Fabrication and evaluation of a near-infrared hyperspectral imaging system.

Summary This paper describes modifications to a hyperspectral imaging microscope that extend its capabilities into the near-infrared (950–1300 nm). The major changes include installing a grating, charge-coupled device camera, and lenses and filters appropriate for infrared wavelengths. Calibration of the system and validation with lead sulfide quantum dots of known emission wavelength is reported. Cells from the breast carcinoma cell line SkBr3 were scanned with lead sulfide quantum dots that emit at 1100 nm as the background and an image which contains the integrated spectral data is presented. We also demonstrate that this instrument is capable of detecting the photoluminescence spectra of single-walled carbon nanotubes dispersed in aqueous solution.
Effect of composition on clustering in Er-doped fiber lasers

11Erbium Doped Fiber Laser (EDFL) experimental slope efficiencies are used in conjunction with a paired ion model to estimate the percentage of paired ions in a fiber as a function of the erbium concentration. These percentages are compiled with other published results to derive a dependence of percentage of pairs on the aluminum co-dopant concentration. A mole ion concentration ratio of 20 aluminum to 1 erbium is found to greatly reduce pairing. Higher ratios are found to have minimal added benefit.
Neutron-Proton Angular Distribution at 24 MeV

Proton recoil spectra from $n\ensuremath{-}p$ elastic scattering were measured with a counter telescope for an incident neutron energy of 24.0 MeV at mean lab proton recoil angles of 8\ifmmode^\circ\else\textdegree\fi{}, 17\ifmmode^\circ\else\textdegree\fi{}, 31\ifmmode^\circ\else\textdegree\fi{}, and 45\ifmmode^\circ\else\textdegree\fi{}, corresponding to c.m. neutron scattering angles of 164\ifmmode^\circ\else\textdegree\fi{}, 146\ifmmode^\circ\else\textdegree\fi{}, 118\ifmmode^\circ\else\textdegree\fi{}, and 89\ifmmode^\circ\else\textdegree\fi{}. The ratio $\frac{\ensuremath{\sigma}(164\ifmmode^\circ\else\textdegree\fi{})}{\ensuremath{\sigma}(89\ifmmode^\circ\else\textdegree\fi{})}$ was 1.134\ifmmode\pm\else\textpm\fi{}0.016, where the error quoted is based on counting statistics. In order to obtain a differential cross section, the c.m. relative angular distribution was normalized to a total cross section of 397.2 mb using an $A(1+B{cos}^{2}\ensuremath{\theta})$ fit. This gave $A=30.1\ifmmode\pm\else\textpm\fi{}0.3$ mb/sr and $B=0.146\ifmmode\pm\else\textpm\fi{}0.017$.
Oxidation and reduction of pyridine nucleotides by purified chloroplasts

Abstract Highly purified chloroplasts photochemically reduce all Hill reaction oxidants tested including TPN, but not DPN. Since chloroplasts are almost entirely unable to oxidize reduced TPN in the dark, it is inferred that a photooxidation of TPNH must occur. Some evidence for this photooxidation is presented. Chloroplasts oxidize TPNH, but not DPNH, rapidly and in the dark when an intermediate electron acceptor is provided.
Detecting hepatic steatosis using ultrasound-induced thermal strain imaging: an ex vivo animal study

Hepatic steatosis or fatty liver disease occurs when lipids accumulate within the liver and can lead to steatohepatitis, cirrhosis, liver cancer and eventual liver failure requiring liver transplant. Conventional brightness mode (B-mode) ultrasound (US) is the most common noninvasive diagnostic imaging modality used to diagnose hepatic steatosis in clinics. However, it is mostly subjective or requires a reference organ such as the kidney or spleen with which to compare. This comparison can be problematic when the reference organ is diseased or absent. The current work presents an alternative approach to noninvasively detecting liver fat content using US-induced thermal strain imaging (US-TSI). This technique is based on the difference in the change in the speed of sound as a function of temperature between water- and lipid-based tissues. US-TSI was conducted using two system configurations including a mid-frequency scanner with a single linear array transducer (5-14 MHz) for both imaging and heating and a high-frequency (13-24 MHz) small animal imaging system combined with a separate custom-designed US heating transducer array. Fatty livers (n = 10) with high fat content (45.6 ± 11.7%) from an obese mouse model and control livers (n = 10) with low fat content (4.8 ± 2.9%) from wild-type mice were embedded in gelatin. Then, US imaging was performed before and after US induced heating. Heating time periods of ∼ 3 s and ∼ 9.2 s were used for the mid-frequency imaging and high-frequency imaging systems, respectively, to induce temperature changes of approximately 1.5 °C. The apparent echo shifts that were induced as a result of sound speed change were estimated using 2D phase-sensitive speckle tracking. Following US-TSI, histology was performed to stain lipids and measure percentage fat in the mouse livers. Thermal strain measurements in fatty livers (-0.065 ± 0.079%) were significantly (p < 0.05) higher than those measured in control livers (-0.124 ± 0.037%). Using histology as a gold standard to classify mouse livers, US-TSI had a sensitivity and specificity of 70% and 90%, respectively. The area under the receiver operating characteristic curve was 0.775. This ex vivo study demonstrates the feasibility of using US-TSI to detect fatty livers and warrants further investigation of US-TSI as a diagnostic tool for hepatic steatosis.
Death anxiety, dissent, and competence.

A total of 64 male undergraduates were administered a multistage interview which was structured to assess (a) their level of overtly expressed death anxiety, (b) covert (GSR) arousal to death stimuli, (c) self-perceived competence, and (d) agreement with or dissent from life threatening national policies. The analyses that followed were concerned with examining the relationships among these variables. In previous studies of this kind it had been typically found that (1) self-perceived competence and magnitude of expressed death concern are inversely related and (2) overt expressions of death concern and covert physiological arousal to death cues are inversely related. Psychodynamic formulations centering on the ego-defensive nature of inhibited expressions of death anxiety have been cited to explain these past data. The current investigation proposed that the magnitude of expressed death concern would bear an inverse relationship to both felt competence and covert death arousal only when the level of overt concern was not contingent upon the individual's attitudes concerning the imminence of real life threatening circumstances in the environment. The rationale behind these predictions inheres in the notion that the neurotic components of strongly expressed death anxiety derive from its lack of anchoring in “real” external threats. Conversely, the expression of low death fear can only be regarded as “defensive” when real threats are perceived and acknowledged. The obtained results strongly support this rationale and the discussion centers on the impact of social conditions on psychodynamic processes.