cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular dynamics simulations of DiI-C18(3) in a DPPC lipid bilayer

We performed a 40 ns simulation of 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI-C18(3)) in a 1,2-dipalmitoyl-sn-glycero-3-phosphatidyl choline (DPPC) bilayer in order to facilitate interpretation of lipid dynamics and membrane structure from fluorescence lifetime, anisotropy, and fluorescence correlations spectroscopy (FCS). Incorporation of DiI of 1.6 to 3.2 mol% induced negligible changes in area per lipid but detectable increases in bilayer thickness, each of which are indicators of membrane structural perturbation. The DiI chromophore angle was 77 ± 17° with respect to the bilayer normal, consistent with rotational diffusion inferred from polarization studies. The DiI headgroup was located 0.63 nm below the lipid head group–water interface, a novel result in contrast to some popular cartoon representations of DiI but consistent with DiI’s increase in quantum yield when incorporated into lipid bilayers. Importantly, the fast component of rotational anisotropy matched published experimental results demonstrating that sufficient free volume exists at the sub-interfacial region to support fast rotations. Simulations with non-charged DiI head groups exhibited DiI flip-flop, demonstrating that the positively-charged chromophore stabilizes the orientation and location of DiI in a single monolayer. DiI induced detectable changes in interfacial properties of water ordering, electrostatic potential, and changes in P–N vector orientation of DPPC lipids. The diffusion coefficient of DiI (9.7 ± 0.02 × 10−8 cm2 s−1) was similar to the diffusion of DPPC molecules (10.7 ± 0.04 × 10−8 cm2 s−1), supporting the conclusion that DiI dynamics reflect lipid dynamics. These results provide the first atomistic level insight into DiI dynamics, results essential in elucidating lipid dynamics through single molecule fluorescence studies.
ASYMPTOTIC FREEDOM CONSTRAINTS ON GRAND UNIFIED GAUGE THEORIES

Constraints on the fermion and Higgs scalar content of grand unified gauge theories, imposed by the requirement of asymptotic freedom for the gauge couplings, are derived for models which have fermion representations with only color singlets and color triplets. The constraintn f ≦16 on the numbern f of flavors of color triplet quarks in pure QCD is removed. Definitive limits are placed on the representation content of theories based on the exceptional groups.
DAVINCI.BYU: Engineering workstation management software

Abstract Computer software has been developed to take advantage of hardware advances in engineering workstations. A definition of the engineering workstation and its environment is given. Requirements of a good user interface is discussed and supporting software is described. A general workstation manager program is reviewed that provides a support layer between the user and the operating system, organizes software and data files, and facilitates on-line documentation and demonstrations.
Fundamental Absorption Edge in Cadmium Sulfide

The absorption and reflection spectra of CdS have been determined in the temperature range 90\ifmmode^\circ\else\textdegree\fi{}-340\ifmmode^\circ\else\textdegree\fi{}K by photoelectric measurements on single crystals, using polarized light. The temperature and frequency dependence of the absorption coefficient in the edge, over a substantial range of absorption magnitudes, are well described by expressions of the form $\ensuremath{\alpha}(\ensuremath{\nu})={\ensuremath{\alpha}}_{0}\mathrm{exp}[\ensuremath{-}\frac{\ensuremath{\beta}({E}_{00}\ensuremath{-}CT\ensuremath{-}h\ensuremath{\nu})}{\mathrm{kT}}]$, where the energy (${E}_{00}\ensuremath{-}CT$) is closely associated with the position of an absorption peak. For light polarized with $E$ vector parallel to the crystalline $c$ axis, there is one such peak, at $\ensuremath{\lambda}4844$ A at 90\ifmmode^\circ\else\textdegree\fi{}K; for light polarized with $E$ vector perpendicular to the $c$ axis, the 4844 A absorption is again present in about equal strength and a stronger line appears at $\ensuremath{\lambda}4874$ A, shifting the absorption edge toward longer wavelengths by a corresponding amount. These absorption lines, or sharp bands, are observed in the reflectance spectrum, and correspond to absorption lines observed photographically by Gross and others. These results are discussed in the light of the present theoretical picture of absorption in insulating crystals, and it is noted that an exponential absorption edge of this kind, characteristic also of other ionic crystals, cannot be adequately explained in terms of existing models.
National long-term investment planning for energy and transportation systems

The most significant energy consuming infrastructures and the greatest contributors to greenhouse gases in the US today are electric and freight/passenger transportation systems. Technological alternatives for producing, transporting, and converting energy for electric and transportation systems are numerous. Selecting from among them requires long-term assessment since these capital-intensive infrastructures take years to build with lifetimes approaching a century. The advent of electrified transportation creates interdependencies between the two infrastructures that may be both problematic and beneficial. We are developing modeling capability to perform long-term electric/transportation infrastructure design at a national level, accounting for their interdependencies. The approach combines network flow/DC-flow modeling with a multiobjective solution method. We motivate the need for this work by summarizing attributes and issues related to the investment planning problem so as to find minimum-cost, low-emission, resilient infrastructure portfolios for the future. State-of-the-art energy planning models are summarized, and we describe our software design which includes a multiobjective evolutionary algorithm with a network linear programming cost minimization fitness evaluation, together with metrics for evaluating resiliency and sustainability.
Funeral Co-Op Members' Characteristics and Motives

Memorial societies are movement organizations of the consumer cooperative movement concerned with funeral and death issues. A member survey in four California memorial societies disclosed that the typical member was a retired individual in his or her sixties, with a spouse in the same age range, Anglo, and college educated. The main reasons for joining the society were a desire to obtain a simple inexpensive funeral and reduce responsibilities for survivors. The contributions of memorial societies in consumer education, protection, and reform of the funeral industry are discussed.
Attribute dimensions and patterns of trait inferences

Rosenberg, Nelson, & Vivekananthan (1968) have suggested that Asch’s (1946) “warm-cold” effect can be meaningfully interpreted within the framework of two dimensions (social and intellectual desirability) which underlie personality impressions. Their analysis suggested that the manipulation of unique information on one dimension would affect trait inferences on that dimension alone. This hypothesis was tested by replicating and extending Asch’s experiment in terms of these two dimensions. The results strongly supported the hypothesis.
The pulmonary toxicity of talc and granite dust as estimated from an in vivo hamster bioassay

A short-term animal bioassay was used to assess the toxicity of occupational dusts. We quantified pulmonary responses in hamsters exposed to granite (12% quartz) and talc (quartz and asbestos-free) dust collected from worksites. Personal samples collected on workers showed similar quartz content and particle-size distributions to the high-volume samples collected for bioassays, thus demonstrating that the particulates were representative of worker exposure. We measured biochemical and cellular indicators of injury in bronchoalveolar lavage fluid (BAL) of animals exposed to dust suspensions by intra-tracheal instillation. The assays measured release of cytoplasmic and lysosomal enzymes into the cell-free supernatant of BAL; levels of albumin and red blood cells; changes in macrophage and polymorphonuclear neutrophil cell numbers; and in situ macrophage phagocytosis. Dose-response (0.15, 0.75, and 3.75 mg/100 g body wt) and time-course (1-14 days postexposure) studies were performed. One day after exposure, both talc and granite dust resulted in elevated enzyme levels, pulmonary edema, and increased cell numbers in BAL. Macrophage phagocytosis was also inhibited. Based on earlier studies, response levels were either intermediate between nontoxic iron oxide and toxic alpha-quartz or comparable with alpha-quartz. The response to granite dust diminished fairly rapidly over time. By contrast, after talc exposure, there was a more persistent elevation in enzyme levels, and macrophage phagocytosis remained depressed. These results indicate that, when a similar mass was deposited in the lungs, talc caused more lung injury than did granite. Better estimates of exposure-dose relationships in talc and granite workers as well as longer-term animal studies are required to evaluate the harmfulness of these work environments at present-day exposure levels.
Increases in blood glucose in older adults: the effects of spousal health.

Objective: The death or illness of a spouse negatively affects a partner’s health, but little is known about the effect on blood glucose (glycemic) levels. This study investigates the extent to which a spouse’s declining health or death is associated with changes in the glycemic levels of older adults. Method: Data come from a nationally representative longitudinal sample of 597 Taiwanese (aged 54 to 90). We use changes in spousal health and death of a spouse to predict changes in glycosylated hemoglobin (HbA1c) levels over a 6-year period. Results: A decline in spousal health is associated with increased HbA1c levels for women, but not for men. The death of a healthy spouse is associated with increased HbA1c levels for both genders. Discussion: Stressful life transitions may compromise the glycemic levels of older adults. Taking on a caregiving role may erode some of the benefits of marriage and interfere with women’s maintenance of their own health.
Permeability barrier disruption alters the localization and expression of TNFα/protein in the epidermis

Previous studies have shown that (1) epidermal TNF alpha mRNA levels are increased following acute disruption of the cutaneous permeability barrier; (2) this increase is maximal at 1 h and decreases to control levels by 8 h; and (3) in essential fatty acid-deficient (EFAD) mice, a chronic model of barrier perturbation, TNF alpha mRNA levels are also elevated several-fold over controls. In the present study we determined, using immunocytochemical procedures, epidermal TNF alpha protein levels following either acute of chronic barrier disruption and the localization of any increase. Frozen, paraffin and Antibed sections of skin were incubated with polyclonal anti-mouse TNF alpha antisera and detection was accomplished by either immunoperoxidase or fluorescence procedures. We found that (1) TNF alpha-immunoreactive protein was present in normal mouse epidermis, and was primarily localized to the upper nucleated layers where it displayed a diffuse cytosolic pattern; (2) acute disruption of the barrier with acetone or tape-stripping resulted in TNF alpha staining that was more intense throughout all of the nucleated epidermal cell layers in comparison with normal epidermis; (3) the increase in TNF alpha staining occurred as early as 2 h after barrier disruption; and (4) increased TNF alpha staining was also observed in the stratum corneum of EFAD mice. These results indicate that epidermal TNF alpha protein levels increase after both acute and chronic barrier disruption, and are consistent with the hypothesis that TNF alpha may signal and/or coordinate portions of the cutaneous response to barrier disruption.
Electrophysiologic testing in patients at high risk for sudden cardiac death. I. nonsustained ventricular tachycardia and abnormal ventricular function

Nonsustained ventricular tachycardia, although usually asymptomatic, is associated with a high risk of sudden cardiac death in patients with depressed left ventricular function. To test the vulnerability of such patients to symptomatic and potentially life-threatening arrhythmias, complete electrophysiologic studies were performed in 58 patients with clinically documented non-sustained ventricular tachycardia (≥three complexes but These results indicate that: 1) patients with clinical nonsustained ventricular tachycardia and chronic left ventricular dysfunction have a high incidence of inducible sustained ventricular tachycardia or ventricular fibrillation; and 2) electrophysiologic testing may allow further substratification of risk of sudden cardiac death in high risk patients with nonsustained ventricular tachycardia.
Antioxidant enzymes in the differentiated Caco-2 cell line

Injury to the gastrointestinal tract by oxygen dependent processes is important in ischemia, inflammatory bowel disease, and necrotizing enterocolitis. The Caco-2 cell line is an important tool in assessing various gastrointestinal functions and offers a unique opportunity to assess gastrointestinal oxidant metabolism on a cellular level. However, some Caco-2 cell functions change with time after confluence. To determine if antioxidant enzyme activity changes during differentiation, Caco-2 cells were grown to confluence, and superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase activities and specific mRNA content were quantitated. With time after confluence the enzymes demonstrated a small, but statistically significant increase in activity. Neither superoxide dismutase nor glutathione peroxidase mRNA levels correlated with enzyme activity changes. Catalase mRNA levels increased as catalase activity increased. Thus, differentiated Caco-2 cells express superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase activities and the superoxide dismutase, glutathione peroxidase, and catalase genes. Superoxide dismutase activity and glutathione peroxidase activity do not correlate with mRNA levels, and suggest that regulation may be at a level other than transcription. The correlation between catalase activity and catalase mRNA suggests differentiation may occur at transcription. If Caco-2 cells are used to elucidate oxidative metabolism, changes in activities of antioxidant enzymes as a function of cell differentiation should be considered.
Yield stress of coal-water mixtures

Abstract The yield stresses of coal-water mixtures as functions of solids volume fraction, suspended particle size, and suspension pH were measured using the vane method. The suspension yield stress-solids volume fraction data were used to estimate the asymptotic values of solids concentration in the limit of infinite yield stress. The limiting solids volume fractions, obtained by such an extrapolation, were found to be approximately the same as those estimated independently from the irreducible sediment volumes obtained by centrifugation. The yield stress-concentration dependence was found to depend on particle size as well as pH, or the corresponding zeta potential which was also measured. However, for a given particle size mix the yield stress-concentration plots for different pH appeared to converge, as the yield stress became large, and to approach a common asymptotic value of solids concentration in the limit of infinite yield stress. A number of different extrapolation procedures were tested to establish the type of plot capable of providing a consistent, unambiguous value of these limiting concentrations. The procedures for estimating the maximum packing solids concentrations from centrifugal sedimentation were also tested by varying the speed and the duration of centrifugation. The solids concentration dependence of the yield stress of CWM was found to be described by two-parameter non-linear relationships based upon the mean interparticle spacing, and incorporating the maximum packing volume of solids. Furthermore, it is established that the yield stress is proportional to the reciprocal of the mean particle size.
Semidiscrete least squares methods for linear hyperbolic systems

Some approximate methods for solving linear hyperbolic systems are presented and analyzed. The methods consist of discretizing with respect to time and solving the resulting hyperbolic system for fixed time by least squares finite element methods. An analysis of least squares approximations is given, including optimal order estimates for piecewise polynomial approximation spaces. Numerical results for the inviscid Burgers' equation are also presented. © 1992 John Wiley & Sons, Inc.
Neuroscience: The Study of the Nervous System & Its Functions

Neuroscience is the scienti1⁄2c study of the nervous system (the brain, spinal cord, and peripheral nervous system) and its functions. The belief that the brain is the organ that controls behavior has an cient roots, dating to early civilizations that connected loss of function to damage to parts of the brain and spinal cord. But the modern era of neuroscience began–and continues to progress–with the development of tools, techniques, and methods used to measure in ever more detail and complexity the structure and function of the nervous system. The modern era of neuroscience can be traced to the 1890s, when the Spanish pathologist Santiago Ramon y Cajal used a method developed by the Italian physician Camillo Golgi to stain nerve tissues to visualize the morphology and structure of the neurons and their connections. The detailed de scription of the neurons and their connections by Cajal, his students, and their followers led to the “neuron doctrine,” which proposed that the neuron is the functional unit of the nervous system. We now know that the human brain contains ap proximately one hundred billion neurons and that these neurons have some one hundred trillion connections, forming functional and de1⁄2nable circuits. These neural circuits can be organized into larger
SENSORY EVALUATION AND PROTEIN VALUE OF BEEF AND BEEF‐COTTONSEED BLENDS

Textured cottonseed flour (TCF) was added to ground beef at levels of 15 and 30%. Effects on chemical and sensory properties were determined by compositional analysis and sensory evaluation of cooked beef patties. Protein quality was evaluated by rat feeding studies. Although ooking losses and cooking time, moisture and protein contents were inaffected by TCF, fat content was greater for 100% beef patties, and Gardner redness values decreased while yellowness increased with increased TCF. Increasing TCF decreased beef flavor and aroma and increased cereal flavor and aroma. Texture, similar for 100 or 85% beef patties, was mealier for patties containing 70% beef, and 100% beef patties were juicier. Growth (measured by protein efficiency ratios) was supported at a higher rate by beef blends than by casein, and net protein ratios, similar for 100 or 85% beef blends, were lower for the 70% blend. Digestibility of all treatments was excellent.
Computer programs for autonomic research

Eleven computer programs are presented for analysis of autonomic data. The statistical procedures executed by these programs are drawn primarily from analysis of variance, and where appropriate the standard F-tests are supplemented by tests for trend. The trend analysis provides for a detailed appraisal of the form and amplitude of autonomic response curves, and it can detect curve changes that result from such processes as habituation, learning and extinction. It can also detect between-group differences in curve form and identify the group(s) that are primarily responsible for the differences.
Kinetic model for sintering of supported metal particles with improved size-dependent energetics and applications to Au on TiO 2 ( 110 )

A kinetic model for the sintering of metal particles on oxide or other support surfaces is derived and applied to simulate experimental measurements of the sintering of a model gold catalyst: gold nanoparticles supported on ${\mathrm{TiO}}_{2}(110)$. It follows the pioneering work of Wynblatt and Gjostein (WG), Progress in Solid State Chemistry (1975, p. 21), but removes several important assumptions that create dramatic errors in sintering rates for particles smaller than $6\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ in diameter, including (1) use of the Gibbs-Thomson relation assuming that the surface free energy of metal particles is independent of size, and (2) neglect of all but the first-order terms in a Taylor series expansion. Recent microcalorimetry measurements have shown these assumptions to be untrue in that metal particles smaller than $6\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ have much higher surface free energies than large particles. A modified bond-additivity model more accurately estimates particle energy versus size. This estimate was incorporated into the kinetic model of WG and applied to simulate the sintering of Au particles on ${\mathrm{TiO}}_{2}(110)$ as measured by temperature-programmed low-energy ion scattering. Our model reproduces well the broad temperature range over which sintering typically occurs in such experiments. This is analogous to accurate modeling of long-term sintering kinetics of metal nanoparticles under the isothermal conditions of real catalysis. These results also highlight problems with classical methods for determining the sintering mechanism based solely upon the shape of the sintered particle-size distribution.
Black youth violence has a bad rap

This research elicited and assessed the perspectives on violence of 41 middle-school students attending a unique school in a low-income section of a large northern California city. Through participation in and observation of instruction and other school-related activities, the researchers explored ways that these students experienced and reflected on violence in their lives and in popular culture. The researchers probed ways that these students' interpreted or reflected upon rap music and hip-hop culture, particularly its representations of violence, crime, and sex. This research provided insights into what these youth thought about violence in their lives including its depictions in electronic media. Additionally, it revealed ways that they resisted and/or critiqued some negative images and influences of hip-hop and rap.
Analysis of microstrip discontinuities on suspended and grounded anisotropic substrates

This article presents a comprehensive numerical study of resonant and nonresonant microstrip discontinuities that are printed on anisotropic substrates. The approach employs the method of moments (MoM), which is implemented for the gap, step, and stub discontinuities for the first time in MICs with other than biaxial anisotropic substrates. Numerical results include the variation of the normalized gap admittances with respect to different material parameters, insertion and transmission loss of step discontinuities, and shifts in resonant frequencies of tuning stubs due to rotation of the principal axes of the substrate. Computed data are validated for every structure against results in previously published literature. © 1995 John Wiley & Sons, Inc.
Dynamic responsiveness of lumbar paraspinal muscle spindles during vertebral movement in the cat.

Muscle spindles provide essential information for appropriate motor control. In appendicular muscles, much is known about their position and movement sensitivities, but little is known about the axial muscles of the low back. We investigated the dynamic responsiveness of lumbar paraspinal muscle spindle afferents from L6 dorsal root filaments during constant velocity movement of the L6 vertebra (the feline has seven lumbar vertebrae) in Nembutal-anesthetized cats. Actuations of 1 mm applied at the L6 spinous process were delivered at 0.5, 1.0 and 2.0 mm/s. The slow velocity component was measured as the slope of the relationship between displacement during the constant velocity ramp and instantaneous discharge frequency. The quick velocity component was the slope’s intercept at zero displacement. The peak component was determined as the highest discharge rates occurring near the end of the ramp compared with control. The slow velocity component over the three increasing velocities was 23.9 (9.9), 21.6 (9.6) and 20.5 (9.5) imp/(s mm) [mean (SD)], respectively. The quick velocity component was 28.4 (8.6), 31.4 (9.8) and 35.8 (10.6) imp/s, respectively. These measures of dynamic responsiveness were at least 5–10 times higher compared with values reported for appendicular muscle spindles. The peak component’s velocity sensitivity was 2.9 (imp/s)/(mm/s) [0.2, 5.5, lower, upper 95% confidence interval] similar to that for cervical paraspinal muscles as well as appendicular muscles. Increased dynamic responsiveness of lumbar paraspinal muscle spindles may insure central driving to insure control of intervertebral motion during changes in spinal orientation. It may also contribute to large, rapid and potentially injurious increases in paraspinal muscle activity during sudden and unexpected muscle stretch.
Statistical evidence for non-random clustering of synaptic vesicles associated with filamentous interconnections

Abstract Synaptic vesicles were found to be non-randomly distributed in the synaptic region of nerve terminals. This was visible as an abundance of tightly clustered groups of vesicles. Two or more vesicles were interconected by filaments far more often than could be explained by chance alignment. These could play a major role in vesicular release.
Effect of Escherichia coli biomass composition on central metabolic fluxes predicted by a stoichiometric model.

The amino acid composition of proteins and the fatty acid composition of the cell membranes were measured in Escherichia coli growing exponentially in batch culture on glucose, succinate, glycerol, pyruvate, and acetate, and growing under continuous culture conditions on glucose at dilutions rates equivalent to the growth rates of the batch cultures. Although the fatty acid composition of the membranes did change significantly with carbon source and dilution rate, the amino acid content of proteins did not change significantly under either condition. A previously developed stoichiometric model of metabolism was used to calculate the fluxes through the metabolic reactions and to determine their sensitivity to changes in fatty acid and amino acid composition.
Plasmonic photoconductive antennas for high-power terahertz generation and high-sensitivity terahertz detection

High power sources and high sensitivity detectors are in demand for any terahertz imaging and sensing system. Incorporating plasmonic contact electrodes in photoconductive terahertz sources and detectors has proved to offer higher terahertz radiation powers and detection sensitivities by enhancing the photoconductor quantum efficiency significantly. This is because of the unique capability of plasmonic electrodes in manipulating the concentration of photocarriers near photoconductor contact electrodes, allowing a larger number of photocarriers reach photoconductor contact electrodes within a terahertz oscillation cycle to efficiently contribute to terahertz radiation and detection. The impact of plasmonic electrodes on enhancing the output power and detection sensitivity of photoconductive terahertz sources and detectors is universal and can be employed in various types of photoconductive terahertz antennas, as summarized in this article.
Identification of Vascular Lineage-Specific Genes by Transcriptional Profiling of Isolated Blood Vascular and Lymphatic Endothelial Cells

In mammals, the lymphatic vascular system develops by budding of lymphatic progenitor endothelial cells from embryonic veins to form a distinct network of draining vessels with important functions in the immune response and in cancer metastasis. However, the lineage-specific molecular characteristics of blood vascular versus lymphatic endothelium have remained poorly defined. We isolated lymphatic endothelial cells (LECs) and blood vascular endothelial cells (BVECs) by immunomagnetic isolation directly from human skin. Cultured LECs but not BVECs expressed the lymphatic markers Prox1 and LYVE-1 and formed LYVE-1-positive vascular tubes after implantation in vivo. Transcriptional profiling studies revealed increased expression of several extracellular matrix and adhesion molecules in BVECs, including versican, collagens, laminin, and N-cadherin, and of the growth factor receptors endoglin and vascular endothelial growth factor receptor-1/Flt-1. Differential immunostains of human skin confirmed the blood vessel-specific expression of these genes. During embryonic development, endoglin expression was gradually down-regulated on lymphatic endothelium whereas vascular endothelial growth factor receptor-1 was absent from lymphatics. We also identified several genes with specific expression in LECs. These results demonstrate that some lineage-specific genes are only expressed during distinct developmental stages and they identify new molecular markers for blood vascular and lymphatic endothelium with important implications for future studies of vascular development and function.
Recent heavy meson results from CLEO

Recent results from CLEO in the study of rare, semileptonic and hadronic B decays will be presented, as well as measurements of charm meson properties.
The Effects of LOGO on Children's Conceptualizations of Angle and Polygons

It has been claimed that in Logo programming children learn mathematics by using concepts that aid them in understanding and directing the turtle's movements. The fundamental basis for this claim is that appropriate Logo environments can help children elaborate on, and become cognizant of, the mathematics implicit in certain kinds of intuitive thinking. To investigate this claim, 12 fourth graders were interviewed three times, at the beginning, middle, and end of 40 sessions of Logo graphics programming experience. The six Logo children, but not the comparison children, progressed from their original intuitive notions to more mathematically sophisticated and elaborate ideas of angle, angle size, and rotation. In addition, more Logo children explicitly mentioned geometric properties of shapes, indicating that they were beginning to think of the shapes in terms of their properties instead of as visual gestalts. Thus, there was support for the hypothesis that Logo experiences, especially those enriched with appropriate activities and discussions, can help children become cognizant of their mathematical intuitions and move to higher levels of geometric thinking.
Measurement of total protein in urine: Comparison of two dye-binding procedures with a gel filtration/modified biuret method

Abstract Two dye-binding methods for the determination of urinary total protein concentration have been compared to a biuret-based procedure requiring a preliminary gel filtration step. The biuret-based procedure is claimed to be both specific and sensitive for the measurement of protein in urine. With those urines having relatively low protein concentrations, the dye-binding methods provide values about one-half of those given by the modified biuret procedure. This difference disappears when urines containing high levels of protein are measured. The lower results obtained at normal protein levels are most likely caused by the inability of dye-binding methods to measure proteins of high carbohydrate content (such as uromucoid) accurately. In spite of this limitation, both dye-binding methods appear suitable for routine use. In contrast to the biuret-based procedure, we found the dye-binding methods to be free from interferences by compounds known to appear in urine in high concentrations.
One-Electron Rotatory Power

It is shown that a single electron moving in a field of suitable dissymmetry can give rise to optical rotatory power in a medium containing molecules of this type. This effect is called one-electron rotatory power and is in striking contrast to the models developed by Born, Oseen, Gray and others in which a dynamic coupling between several electronic oscillators is responsible for the rotatory power. The detailed calculations are carried out for the potential function, $$ V = \tfrac{1}{2}({k_1}{x^2} + {k_2}{y^2} + {k_3}{z^2}) + Axyz $$ which shows rotatory power both quantum mechanically and classically. Next it is shown how fields of this type may be adapted to an approximate description of the field in which the chromophoric electrons of a molecule move, the constants k 1 , k 2 , k 3 and A being largely determined by the average charge on the different atoms of the molecule as found from additivity of dipole moments due to the bonds in the molecule. As illustrations of the theory absolute calculations are made for the contribution of the nitrite group to the rotatory power of methyl phenyl carbinol nitrite which agrees satisfactorily with experimental data, for the phenyl group contribution of the same molecule and for the hydroxyl group contribution in secondary butyl alcohol. In the latter two instances the theoretical values are much too small but as there is a great deal of freedom in the choice of the configuration because of free rotation these results merely indicate need for more detailed calculations.
Nutrition in Trauma and Critically Ill Patients

Despite significant improvements in the practice of metabolic support of critically ill patients in recent years, malnutrition continues to be common among surgical patients, adding significantly to complications, infections, length of stay, costs, and increased mortality. Furthermore, hypercatabolism is the major metabolic response after major trauma and emergency surgery, making this patient population a unique subgroup of critically ill patients vulnerable to further decline in nutritional status. Many questions have already been answered, such as whether critically ill patients should be fed, when they should be fed, and how nutrients should be delivered. What is not entirely clear is what we should feed critically ill patients at different phases of specific diseases and disorders, as well as whether or not we should enhance and/or modulate patients’ immunity.
Immunoneutralization of procalcitonin or its component peptides: a promising treatment of sepsis.

Sepsis and the severe systemic response syndrome are very common illnesses that are responsible for a great amount of morbidity and death. These closely related conditions are characterized by a remarkable increase in the prohormone ProCT (procalcitonin). ProCT is both a marker of sepsis and a harmful mediator of the disease. In the present issue of Clinical Science, in a study in rats with endotoxin shock, Tavares and Minano used an antibody to a segment of N-ProCT (aminoprocalcitonin) that is part of the ProCT molecule, and confirmed that immunoneutralization of ProCT saves the animals from this severe illness. Furthermore, they extensively studied the epiphenomena associated with this immunoneutralization.
Multiplicity fluctuation and single-particle spectrum in two-jet events in e+e- annihilation.

Recent ideas in the geometrical model of multiparticle production in hadron-hadron collisions are applied to two-jet events in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation. A coherent picture emerges which is compared with experimental data. A number of predictions are made, including the prediction that Koba-Nielsen-Olesen scaling does not obtain for such events. The relationship with QCD models remains unexplored.
White box sampling in uncertain data processing enabled by program analysis

Sampling is a very important and low-cost approach to uncertain data processing, in which output variations caused by input errors are sampled. Traditional methods tend to treat a program as a blackbox. In this paper, we show that through program analysis, we can expose the internals of sample executions so that the process can become more selective and focused. In particular, we develop a sampling runtime that can selectively sample in input error bounds to expose discontinuity in output functions. It identifies all the program factors that can potentially lead to discontinuity and hash the values of such factors during execution in a cost-effective way. The hash values are used to guide the sampling process. Our results show that the technique is very effective for real-world programs. It can achieve the precision of a high sampling rate with the cost of a lower sampling rate.
Volumetric analysis of human spermatozoa.

Summary: In 29 semen samples of men participating in an in vitro fertilization (IVF)-programe the spermatozoan volume was determined on an electronic particle analyzer and a routine semen analysis was performed including the estimation of semen volume, sperm concentration, motility and morphology. Twenty three of the 29 semen samples were able to fertilize human oocytes in the FVF-procedure. There was no statitstically significant difference noted between the spermatozoan volume of the fertile (16.25 ± 0.43 cu microns) and the infertile samples (16.9 ± 0.57 cu microns). Logistic regression analysis indicated that spermatozoan volume was not a significant predictor of fertility. Furthermore, none of the standard sperm parameters appear to be closely related to the mean spermatozoan volume. Volumetrische Untersuchung menschlicher Spermatozoen Zusammenfassung: An 29 Spermaproben aus einem in vitro Fertilisationsprogramm wurde mit einem elektronischen Partikel-Analysiergerat (Elzone computerized Model 112, Particle Data Inc., USA) das Spermavolumen bestimmt. Das Spermavolumen lag zwischen 12 und 20 micron3 und im Mittel bei 16 micron3. Keiner der Standardparameter des Spermiogramms (Ejakulatvolumen, Spermatozoenzahl, Motilitat, Morphologie) zeigte ei-ne enge Korrelation zum Spermavolumen. Auserdem fand sich kein deutlicher Unter-schied im Spermavolumen von Spermaproben, die unter in-vitro-Bedingungen eine Be-fruchtung menschlicher Eizellen erreichen konnten (23 Proben) im Vergleich zu Proben (6 Proben), die keine Befruchtung erzielen konnten.
Effect of hyperbaric oxygen on the survival of pedicled skin flaps.

Abstract Pedicled skin flaps prepared on the lateral abdominal wall and flank of albino rabbits evidenced complete survival when exposed to hyperbaric conditions on each of five consecutive days. In control animals each flap exhibited a minimum of 40% necrosis. Increased flap survival was observed with elevation of alveolar as well as surface oxygen tensions.
Constitutive activation of JAK–STAT3 signaling by BRCA1 in human prostate cancer cells

Germ-line mutations of the breast cancer susceptibility gene 1 (BRCA1) confer a high risk for breast and ovarian cancer in women and prostate cancer in men. The BRCA1 protein contributes to cell proliferation, cell cycle regulation, DNA repair and apoptosis; however, the mechanisms underlying these functions of BRCA1 remain largely unknown. Here, we showed that, in Du-145 human prostate cancer cells, enhanced expression of BRCA1 resulted in constitutive activation of signal transducer and activator transcription factor 3 (STAT3) tyrosine and serine phosphorylation. Moreover, Janus kinase 1 (JAK1) and JAK2, the upstream activators of STAT3, were also activated by BRCA1. Immunoprecipitation assay showed that BRCA1 interacted with JAK1 and JAK2. Blocking STAT3 activation using antisense oligonucleotides significantly inhibited cell proliferation and triggered apoptosis in Du-145 cells with enhanced expression of BRCA1. These findings indicate that BRCA1 interacts with the components of the JAK–STAT signaling cascade and modulates its activation, which may provide a new critical survival signal for the growth of breast, ovarian and prostate cancers in the presence of normal BRCA1.
Active Dendritic Conductances Dynamically Regulate GABA Release from Thalamic Interneurons

Inhibitory interneurons in the dorsal lateral geniculate nucleus (dLGN) process visual information by precisely controlling spike timing and by refining the receptive fields of thalamocortical (TC) neurons. Previous studies indicate that dLGN interneurons inhibit TC neurons by releasing GABA from both axons and dendrites. However, the mechanisms controlling GABA release are poorly understood. Here, using simultaneous whole-cell recordings from interneurons and TC neurons and two-photon calcium imaging, we find that synchronous activation of multiple retinal ganglion cells (RGCs) triggers sodium spikes that propagate throughout interneuron axons and dendrites, and calcium spikes that invade dendrites but not axons. These distinct modes of interneuron firing can trigger both a rapid and a sustained component of inhibition onto TC neurons. Our studies suggest that active conductances make LGN interneurons flexible circuit-elements that can shift their spatial and temporal properties of GABA release in response to coincident activation of functionally related subsets of RGCs.
Solitary wave spikes emitted from a microwave free-electron laser.

Narrow, high-power ``spikes'' can be emitted by a 24-GHz free-electron laser (FEL). Spikes, \ensuremath{\sim}450 psec long, may occur randomly or in a sequence which is not the mode-locked period of the resonator. The slippage of the FEL is varied by changing the diameter of the drift tube. The slippage is zero when the electron axial speed is the same as the wave group velocity. Spiking was observed with and without slippage. Measurements of the FEL spectrum are reported and we compare the spike width with a solitary-wave theory. The experiment rules out the sideband instability or superradiance as a cause for this spiking.
T Cell Recognition and Killing of Vascular Smooth Muscle Cells in Acute Coronary Syndrome

Loss of vascular smooth muscle cells (VSMCs) has been proposed to destabilize the atherosclerotic plaque and contribute to plaque rupture, superimposed thrombosis, and acute coronary syndromes (ACSs). We examined whether VSMCs are susceptible to T cell-induced apoptosis and found that CD4 T cells are highly effective in establishing cell-cell contact with VSMCs and triggering apoptotic death. Visualization of the T cell-VSMC contact zone on the single-cell level revealed that both patient-derived and control CD4 T cells reorganized their cell membrane to assemble an immunologic synapse with the VSMCs. Within 4 to 10 minutes, the membrane proximal signaling molecule ZAP-70 was recruited and phosphorylated. However, only patient-derived CD4 T cells sustained an intact immunologic synapse beyond 10 minutes and generated intracellular calcium signals. CD4 T cells that maintained a synaptic contact and appeared to be responsible for VSMC apoptosis accounted for approximately 20% of the circulating memory T cell population in ACS patients and were rare in the blood of age-matched controls. CD4 T cells from ACS patients were also hyperresponsive to T cell receptor-mediated stimulation when triggered by a superantigen and non-VSMC target cells. Lowered setting of the T cell activation threshold, attributable to excessive amplification of proximal CD3-mediated signals, may contribute to CD4 T cell-mediated killing of VSMCs and promote plaque instability.
Internet adoption and use in small firms: internal processes, organisational culture and the roles of the owner‐manager and key staff

Emerging from a study of Internet adoption in UK Midlands manufacturing small firms is a new typology characterising owners and key staff as Warriors, Interpreters, Clerks and Priests. This typology is used to explore the impacts of internal factors and organisational culture on innovation and new technology usage in small firms.
Microbiota-mediated colonization resistance against intestinal pathogens.

Colonization resistance — protection from exogenous pathogens by commensal bacteria — can be mediated by direct antagonism and by indirect effects on the host immune response. This Review outlines our current knowledge of immune-mediated colonization resistance against clinically relevant, antibiotic-resistant intestinal pathogens and how insights into commensal bacterial species and their mechanisms might be therapeutically used to restore resistance.
Peptide decomposition by extracellular hydrolysis in coastal seawater and salt marsh sediment

Abstract Extracellular peptide hydrolysis rates were measured in seawater and sediment from Flax Pond salt marsh using peptide analogs (LYA-peptides) as substrates. This technique allows the direct measurement of specific hydrolysis products and thus provides insights into enzymatic hydrolysis pathways. In sediments, hydrolysis rate constants of LYA-peptides varied seasonally and with depth. Highest activity was found in spring and summer, and most cores exhibited a subsurface maximum. Calculations using the concentrations of chemically-measured peptides suggested that extracellular hydrolysis of peptides is faster than the rate of free amino acids uptake. However, not all peptides may be available for enzymatic hydrolysis. In both seawater and sediment, extracellular hydrolysis of peptides of up to 8 amino acids yielded smaller peptides and free amino acids. Hydrolysis rates depended on size of the peptide substrate, although a clear relationship with number of amino acid constituents was not evident. Peptides containing >2 amino acids were hydrolyzed 10–400 times faster than dipeptides or the fluorogenic substrate Leucine-MCA. Thus, dipeptidases are either uncommon in nature, or hydrolysis is carried out by nonspecific hydrolases that with a low affinity for dipeptides. This is also suggested by the presence of a lag time before dipeptide hydrolysis begins, and the absence of dipeptide hydrolysis in 0.2-μm-filtered. One implication of this finding is that measurements of hydrolysis rates using substrates like Leu-MCA may not accurately predict the magnitude of hydrolysis rates of macromolecules in the marine environment. Even though dipeptide hydrolysis is slow compared to that of larger peptides, LYA-dipeptides are preferentially produced from the hydrolysis of larger substrates. LYA-dipeptides do not penetrate cell membranes of microorganisms because of their size, but natural dipeptides are smaller and can be transported across the cell membrane. Since dipeptides do not appear to accumulate in natural waters, they must be rapidly removed by microorganisms.
Heavy-ion collisions at RHIC

In the first three years of running, the four RHIC experiments have collected a rich set of high quality data on nuclear collisions over a wide range in collision energy and system size. The data allow a systematic study of the evolution of the collision system from the initial state to the final freeze-out of hadrons. The measurements show convincingly that in Au+Au collisions at the highest RHIC energies, a dense, interacting medium is formed early on. In this paper, some of the key measurements are described that have revealed the unique and sometimes unexpected properties of this medium. PACS: 24.85.+p – 25.75.Nq
Optical-bias-enhanced transient photocurrent in amorphous silicon

Transient photocurrent in a-Si:H film is increased by a factor of more than 10 due to optical-bias illumination. The transient photocurrent is found to decay exponentially shortly after the light pulse is turned off. The exponential-decay time constant of the transient photocurrent, which is interpreted as the lifetime of electrons trapped at the quasi-Fermi-level, is found to be proportional to ${F}^{\mathrm{\ensuremath{-}}0.38}$ (F is the optical-bias level) at room temperature. Enhancement in transient photocurrent response may be understood as a result of partial saturation of the trap states in the band tail by the optical-bias illumination. Because of the partial saturation of the gap states and the use of a weak probe pulse, the system studied by this technique is in a quasi-steady-state with small perturbation where experimental results can be interpreted with little ambiguity. This effect is applied to study the density of the band-tail states of the sample as well as the process of charge recombination.