cssi/SciSciGPT-SciSciNet huggingface dataset:
Antes da Queda do Muro, além dele e sem ele: A estética emergente em Die neuen Leiden...

This article is an analysis of the novel Die neuen Leiden des jungen W. (1973) in the light of its intertextuality with Goethe's, Defoe's and Salinger's texts. It has been suggested that Plenzdorf's novel creates a stylistic and ideological world, which is instigating for the literary paradigms of the Socialist Realism of the 70s in East Germany. Twenty years after the Fall of the Berlin Wall, this created world in the novel seems to be up-to-date or even paradigmatic for the current representation of German Democratic Republic cultural memory in literature and film. The article then relies on an analysis of intertextuality and intermediality as a method to approach processes of transformation. The different processes inherent to the novel and its pretexts have been reported.
Adherence with statin therapy in secondary prevention of coronary heart disease in veterans administration male population

This retrospective cohort study enrolled 8,768 male Veterans Administration patients with coronary heart disease who were prescribed statins from July 1, 1999, to June 30, 2000. After 18 months of follow-up, 71% of the patients had been dispensed ≥80% of the medication. Our population's persistence in using statins was higher than in other open-population cohorts but lower than in randomized controlled trials.
Verapamil sensitive incessant ventricular tachycardia in the newborn

Incessant VTs in infancy are often poorly tolerated. Response to conventional antiarrhythmic therapy is disappointing. The present case involves a 3-week-old infant with an incessant VT of a left bundle branch block, and normal axis morphology. This tachycardia was inducible with both atrial and ventricular pacing, but not by premature stimulation. Tachycardia persisted despite treatment with adenosine, esmolol, procainamide, and flecainide. Intravenous verapamil suppressed tachycardia and prevented inducibility, and no further recurrences were seen on oral verapamil. This case suggests that some incessant VTs in infancy may be due to calcium channel related afterdepolarizations or triggered activation.
Closed leaves in foliated 3-manifolds.

Abstract The purpose of this note is to sketch some results on the existence and properties of multi-holed toral leaves in foliations of closed, orientable 3-manifolds. The complete proofs of these results will appear elsewhere.
Counting paths in Young's lattice

Abstract Young's lattice is the lattice of partitions of integers, ordered by inclusion of diagrams. Standard Young tableaux can be represented as paths in Young's lattice that go up by one square at each step, and more general paths in Young's lattice correspond to more general kinds of tableaux. Using the theory of symmetric functions, in particular Pieri's rule for multiplying a Schur function by a complete symmetric function, we derive formulas for counting paths in Young's lattice that go up or down by horizontal or vertical strips. Our results are related to Richard Stanley's theory of differential posets in the special case of Young's lattice.
An assay for leukoagglutinating lectins using suspension cultured mouse lymphoma cells (BW5147) stained with neutral red.

Abstract A sensitive and rapid assay for leukoagglutinating lectins has been developed. This assay utilizes neutral red-stained mouse lymphoma cells from the suspension cultured cell line BW5147. The agglutination of the stained cells can be monitored visually in a manner similar to that for conventional assays for erythroagglutinating lectins using erythrocytes. The activity of leukoagglutinating lectins that are not capable of agglutinating erythrocytes can be quantified by this assay. The utility of the assay was demonstrated using leukoagglutinating and erythroagglutinating lectins from the seeds of Phaseolus vulgaris and Maackia amurensis .
Influence of drying method on the surface energy of cellulose nanofibrils determined by inverse gas chromatography

Research and development of the renewable nanomaterial cellulose nanofibrils (CNFs) has received considerable attention. The effect of drying on the surface energy of CNFs was investigated. Samples of nanofibrillated cellulose (NFC) and cellulose nanocrystals (CNC) were each subjected to four separate drying methods: air-drying, freeze-drying, spray-drying, and supercritical-drying. The surface morphology of the dried CNFs was examined using a scanning electron microscope. The surface energy of the dried CNFs was determined using inverse gas chromatography at infinite dilution and column temperatures: 30, 40, 50, 55, and 60 °C. Surface energy measurements of supercritical-dried NFCs were performed also at column temperatures: 70, 75, and 80 °C. Different drying methods produced CNFs with different morphologies which in turn significantly influenced their surface energy. Supercritical-drying resulted in NFCs having a dispersion component of surface energy of 98.3±5.8 mJ/m(2) at 30 °C. The dispersion component of surface energy of freeze-dried NFCs (44.3±0.4 mJ/m(2) at 30 °C) and CNCs (46.5±0.9 mJ/m(2) at 30 °C) were the lowest among all the CNFs. The pre-freezing treatment during the freeze-drying process is hypothesized to have a major impact on the dispersion component of surface energy of the CNFs. The acid and base parameters of all the dried CNFs were amphoteric (acidic and basic) although predominantly basic in nature.
Characterization of neuronal nicotinic receptors by snake venom neurotoxins.

Abstract Neuronal nicotinic ACh receptors differ pharmacologically from nicotinic receptors on skeletal muscle. The use of certain snake venom neurotoxins has now led to a more complete determination of the pharmacological properties of these neuronal receptors, as well as to their ultrastructural localization. This review highlights results found using one such neurotoxin, toxin F, (also called bungarotoxin 3.1 and κ-bungarotoxin. Toxin F blocks nicotinic receptors in several neuronal preparations while having little affinity for nicotinic receptors in skeletal muscle. Autoradiographic studies using [ 125 I] toxin F indicate that nicotinic receptors in autonomic ganglia are clustered at synaptic sites, though their density is 3–30 times lower than that of nicotinic receptors at the neuromuscular junction.
Serial plasma catecholamine response early in the course of clinical acute myocardial infarction: relationship to infarct extent and mortality.

Abstract Clinical and experimental evidence suggest that sympathoadrenal activation contributes to mortality in patients with ischemic heart disease. To determine the level of sympathoadrenal activation in the very early phase of acute myocardial infarction (AMI) and to determine if location of infarction (anterior versus inferior) was related to sympathoadrenal activation, we studied norepinephrine (NE) and epinephrine (E) within 4 hours after the onset of symptoms and prior to any rise in plasma creatine kinase (CK). Mean (± SE) initial (NE = 591 ± 111 pg/ml and E=73 ± 19 pg/ml), peak (NE = 1356 ± 178 and E ± 1098 ± 608) and average (NE = 815 ± 142 and E=252 ± 68) plasma catecholamine concentrations were considerbly above normal (NE = 228 ± 10 and E=34 ± 2 pg/ml, n 60) and values were similar for inferior and anterior infarctions. During an 18-month follow-up, three patients died in whom the AMI mean NE and E and peak CK were higher than in the eight late survivors. Thus the three AMI patients with peak EP values > 1000 died, whereas the eight AMI patients with peak EP values p
Phenotypic Characterization of Multifungicide Resistance in Botrytis cinerea Isolates from Strawberry Fields in Florida

Abstract Chemical control has always been essential for the management of gray mold, caused by Botrytis cinerea, to ensure sustainable strawberry production. However, lack of knowledge about actual resistance development may have disastrous consequences and lead to severe epidemics such as the one that affected several strawberry fields in 2012 in Florida. In this study, we tested 392 isolates collected from Florida strawberry fields between 2010 and 2012 for their sensitivity to boscalid (Bosc), a succinate dehydrogenase inhibitor (SdhI); pyraclostrobin, a quinone outside inhibitor (QoI); boscalid + pyraclostrobin (Pristine); fenhexamid, a hydroxyanilide (Hyd); pyrimethanil and cyprodinil, anilinopyrimidines; fludioxonil, a phenylpyrrole; and fludioxonil + cyprodinil (Switch). The respective resistance frequencies for boscalid, pyraclostrobin, Pristine, fenhexamid, cyprodinil, and pyrimethanil were 85.4, 86.5, 86.0, 44.4, 52.7, and 59.5%. Overall, 17.8 and 19.8% of isolates showed reduced sensitivity to ...
Temperature prediction for CO2 laser heating of moving glass rods

Abstract This paper presents a heat transfer model to calculate the temperature field in moving glass rods heated by a CO 2 laser. Conduction and radiation heat transfer in radial and axial directions are taken into account in the current model. The Rosseland diffusion approximation is incorporated to analyze the radiation heat transfer in the glass rod. A two-band model is used to simulate the spectral property of the glass. Results of the simulation show that glass rods of sufficiently large optical thickness should be treated as a semitransparent medium for radiative transfer, and it is reasonably accurate to assume it to be opaque to CO 2 laser irradiation. It has been shown that the resulting temperature profile is strongly dependent on the laser parameters, i.e., the size of laser beam and the power of the laser. The diameter and speed of the moving glass rod are also important in determining the temperature field although the convective heat transfer coefficient between the glass rod and the environment has little effect.
Predictors of hospital mortality for patients with severe sepsis treated with Drotrecogin alfa (activated).

Study Objective. To identify predictors of hospital mortality among patients with severe sepsis who were treated with drotrecogin alfa (activated). Design. Prospective observational cohort study. Setting. A 1400-bed academic medical center. Patients. One hundred two patients treated with drotrecogin alfa (activated) for severe sepsis. Measurements and Main Results. To identify potential risk factors for hospital mortality, the main outcome evaluated, all patients who received drotrecogin alfa (activated) were segregated according to hospital survival. The following characteristics were recorded: age, sex, weight, surgical or nonsurgical, Acute Physiology and Chronic Health Evaluation (APACHE) II score, number of acquired organ-system derangements, mechanical ventilation, use of vasopressors or dobutamine, patient location 24 hours before receiving drotrecogin alfa (activated), source of infection, micro-biologically positive culture, and other process-of-care variables. Of the 102 patients, 43 (42.2%) died during their hospitalization. Potential predictors of hospital mortality identified by univariate analysis included greater APACHE II scores, administration of vasopressin or dobutamine, number of acquired organ-system derangements, time to treatment with drotrecogin alfa (activated), intravenous fluid administered before receiving vasopressors or drotrecogin alfa (activated), number of red blood cell transfusions, and administration of inappropriate initial antimicrobial treatment. Multivariate analysis revealed that vasopressin administration (odds ratio [OR] 3.72, 95% confidence interval [CI] 1.95–7.10), number of acquired organ-system derangements (OR 2.30, 95% CI 1.59–3.31), and administration of inappropriate initial antimicrobial treatment (OR 15.5, 95% CI 6.78–35.6) were independently associated with hospital mortality. Conclusion. Number of acquired organ-system derangements, vasopressin administration, and treatment with an inappropriate initial antimicrobial regimen are independently associated with an increased risk of hospital mortality among patients treated with drotrecogin alfa (activated) for severe sepsis. These findings suggest that other specific medical interventions may increase survival in this patient population.
A Novel Configurational-Bias Monte Carlo Method for Lattice Polymers: Application to Molecules with Multicyclic Architectures

A new configurational-bias Monte Carlo (CBMC) method is developed for lattice polymer simulation. In contrast to usual approaches, no particular structure is assumed a priori. Instead, any regular lattice (whose sites are connected to their neighbors by the same vectors) can be used. The method includes new features such as an algorithm to distinguish all conformations of short ideal chains in regular lattices and a simple selection scheme that can improve general CBMC methods. The method is suitable for simulating molecules with branches and/or closed cycles, allowing the study of polymers with complex, well-defined architectures. It was applied to simulate the conformational and thermal properties of multicyclic molecules in dilute solution. The results indicate systematic changes in the behavior of topologically constrained polymers, such as a shrinking of the radius of gyration, a slight reduction in scaling exponents, and an increase of the globule−coil transition temperatures.
THEORETICAL ANGULAR DISTRIBUTION OF NUCLEON-ANTINUCLEON SCATTERING AT 140 Mev

A possible explanation of the large valuc of the nucleon-antinucleon cross section, in the intermediate energy ranges, has been given by the work of Ball and Chew on the basis of the Yukawa interaction. Using the Gartenhaus potential, with the spin-orbit term added by Signell and Marshack, in the WKB approximation, they obtained results in satisfactory agreement with the experimental data available at that time. Recent experiments with bubble chambers and with emulsions have been planned and are now being carried out in order to obtain a more complete knowledge of the p-p interaction. In connection with this program calculations are reported of the angular distribution of antinucleonnucleon scattering, using the transmission coefficients and the phase shifts given by Ball and Chew. (A.C.)
The Daguerreotype and the Rhetoric of Photographic Technology

Although many excellent histories of photography and its invention exist, few focus on the rhetoric employed in debates over scientific priority and the romantic construct of nature as the active agent in photographic processes. This article surveys the range and complexity of rhetorical claims made for the first practical photographic process, daguerreotypy. It presents a rereading of the standard and romanticized history of the invention, defines the daguerreotype as a made object and cultural artifact with its own supratextual rhetoric, and presents examples from the discourse of 1839-1860 that show how daguerreotypes were argued to be simultaneously equal to, superior to, and inferior to natural human perceptions and representations.
Solution and properties of age population balance models which assume discrete division ages

A solution procedure for models of the transient age distribution which employ the assumption of discrete, constant division ages is developed. The solutions for the final state of the age distribution, the solutions obtained in the limit as time goes to infinity, are found to have properties which do not make biological sense. In particular, the solutions will only approach the steady-state solution for very special initial conditions. For most initial conditions, the solution for the final state will instead exhibit an oscillatory behavior. In addition, the oscillatory solutions are unstable with respect to changes in values of the model parameters and solutions with very different periods of oscillation are found arbitrarily close to each other in the parameter space. Models which assume discrete division ages must therefore be used with caution and may be unsuitable as models of autonomous microbial oscillations.
Induced alterations in calcium uptake rate in normoxic rat proximal tubules

This study in well-oxygenated, freshly isolated rat proximal tubules (RPT), examined the effects of several drugs that alter the transmembrane K+ and Na+ gradients across cell membranes, including valinomycin (VAL), amphotericin B (AMPHO), and ouabain (OUAB). The effects of high extracellular potassium chloride (KCl) concentration (45 mM) and low extracellular sodium concentration (100 mM) were also studied. After 10 min of drug exposure Ca2+ uptake rate (nmol/mg/min) increased from 2.7 to 3.8 with VAL (p <. 02), from 2.9 to 3.7 with AMPHO (p <. 05), from 3.6 to 4.1 with OUAB (p <. 05), and from 3.2 to 4.8 with 45 mM KCl (p <. 001). Ca2+ uptake rate was sustained at these high levels at 20 min in all treated RPT except those exposed to OUAB. LDH release averaged less than 15% in control tubules and did not increase significantly except in RPT treated with VAL, where LDH release at 10 min was 48% and at 20 min was 57% (both p <. 001). Of importance, only in VAL-treated RPT did ATP decrease to low levels (6...
The effect of strain on the magnetic properties of b-axis-oriented Dy thin films

Abstract A MBE growth protocol has been developed to grow thin films and superlattices of rare earths with the HCP (1 1 0 0) b -axis normal to the growth plane. To explore the role of strain, clamping and symmetry-breaking in modifying the magnetic ordering temperatures, ultrathin films of strained Dy have been prepared between Y x Lu (1− x ) alloy buffer layers, so that strain can be tuned from compressive ( x =0) to tensile ( x =1) and chosen values in between. The magnetization behavior varies systematically with strain. This behavior is interpreted in terms of fundamental magnetoelastic interactions.
Transition regimes for growing crack populations

Numerous observational papers on crack populations in the material and geological sciences suggest that cracks evolve in such a way as to organize in specific patterns. However, very little is known about how and why the self-organization comes about. We use a model of tensilelike cracks with friction in order to study the time and space evolution of normal faults. The premise of this spring-block analog is that one could model crustal deformation for long time scales assuming a brittle layer coupled to a ductile substrate. The long time-scale physics incorporated into the model are slip-weakening friction, strain-hardening rheology for coupling the two layers, and randomly distributed yield strength of the brittle layer. We investigate how the evolution of populations of cracks depends on these three effects, using linear stability analysis to calculate the stable regimes for the friction as well as numerical simulations to model the nonlinear interactions of the cracks. We find that we can scale the problem to reduce the relevant parameters to a single one, the slip weakening. We show that the distribution of lengths of active cracks makes a transition from an exponential at very low strains, where crack nucleation prevails, to a power law at low to intermediate strains, where crack growth prevails, to an exponential distribution of the largest cracks at higher strains, where coalescence dominates. There is evidence of these different length distributions in continental and oceanic normal faults. For continental deformation the strain is low, and the faults have power-law frequency-size distributions. For mid-ocean ridge flanks the strain is greater, up to an order of magnitude higher than the continental strain, and faults have exponential-like frequency-size distributions. No theory has been offered to explain this difference in the distributions of continental and mid-ocean faults. In this paper we argue that they are indicative of different stages of evolution. The former faults are at an early stage of relatively small deformation, while the latter are at a later stage of the evolution. For high strain the faults reach a saturation regime with system size cracks evenly spaced in proportion to the brittle layer thickness. We asymptotically approximate the time space evolution of faults as a long time-scale phenomenon, thereby avoiding modeling the short time-scale earthquakes. We show that this assumption is valid, which implies that the faults that creep and faults with earthquakes display the same time and space evolutions.
The role of progesterone receptors in the management of advanced breast cancer

The identification of steroid receptors in human breast cancer tissues has provided biochemical markers to predict hormone responsiveness. Analysis of tumors from 328 patients for the estrogen receptor protein (ERP) revealed significant levels in 225 patients (68%). Fifty-five patients with advanced disease were subjected to hormonal manipulation. Thirty patients underwent ablative surgery consisting of adrenalectomy or adrenalectomy and oophorectomy. Twenty-five patients were treated with additive therapy utilizing the new antiestrogen Tamoxifen. The ECOG criteria for an objective response were applied to all patients. Fifteen of the 24 estrogen receptor-positive patients (63%) subjected to endocrine ablation responded. Eleven of twenty (55%) ERP-positive patients responded to Tamoxifen therapy. Only one ERP-negative patient responded in the total group. Simultaneous analysis of these same specimens for the progesterone receptor protein (PgRP) revealed that 151 patients were ERP and PgRP positive (46%); 74 (23%) were ERP positive and PgRP negative; 90 (27%) were ERP and PgRP negative, and 13 (4%) were ERP negative and PgRP positive. In the two treatment groups the overall response rate when both receptors were positive was 77% with a higher percentage of responders in the endocrine ablative group (88% vs. 64%). In addition, a greater duration of response was achieved in those patients treated with endocrine ablation.
A System of Notation of Dyadic Interaction

The necessity of organizing the large quantity of data derived from the use of the Ravich Interpersonal Game-Test (RIG/T) (1) has led to the development of a system of notation of two-person interaction.
Amygdala-prefrontal cortex functional connectivity during threat-induced anxiety and goal distraction.

Abstract Background Anxiety produced by environmental threats can impair goal-directed processing and is associated with a range of psychiatric disorders, particularly when aversive events occur unpredictably. The prefrontal cortex (PFC) is thought to implement controls that minimize performance disruptions from threat-induced anxiety and goal distraction by modulating activity in regions involved in threat detection, such as the amygdala. The inferior frontal gyrus (IFG), orbitofrontal cortex (OFC), and ventromedial PFC (vmPFC) have been linked to the regulation of anxiety during threat exposure. We developed a paradigm to determine if threat-induced anxiety would enhance functional connectivity between the amygdala and IFG, OFC, and vmPFC. Methods Healthy adults performed a computer-gaming style task involving capturing prey and evading predators to optimize monetary rewards while exposed to the threat of unpredictable shock. Psychophysiological recording ( n = 26) and functional magnetic resonance imaging scanning ( n = 17) were collected during the task in separate cohorts. Task-specific changes in functional connectivity with the amygdala were examined using psychophysiological interaction analysis. Results Threat exposure resulted in greater arousal measured by increased skin conductance but did not influence performance (i.e., monetary losses or rewards). Greater functional connectivity between the right amygdala and bilateral IFG, OFC, vmPFC, anterior cingulate cortex, and frontopolar cortex was associated with threat exposure. Conclusions Exposure to unpredictable threat modulates amygdala-PFC functional connectivity that may help maintain performance when experiencing anxiety induced by threat. Our paradigm is well-suited to explore the neural underpinnings of the anxiety response to unpredictable threat in patients with various anxiety disorders.
Substrate Binding Triggers a Switch in the Iron Coordination in Dehaloperoxidase from Amphitrite ornata: HYSCORE Experiments

Dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata is the first known hemoglobin to exhibit efficient peroxidase activity in the oxidation of phenolic substrates. Hyperfine sublevel correlation spectroscopic (HYSCORE) analysis of the ferric form of DHP was carried out to characterize effects of the substrate 2,4,6-trifluorophenol (TFP) binding on the iron coordination in order to elucidate the molecular mechanism of the change in protein function from a globin to a peroxidase. Continuous wave EPR spectra show that heme iron of DHP at pH 6.0 exists in the high spin state. HYSCORE spectra recorded at magnetic field corresponding to g = 2 revealed the presence of exchangeable protons with hyperfine coupling of ca. 6 MHz, consistent with a water molecule being the sixth ligand in the iron coordination. These protons' spectral features disappeared upon substrate binding. This observation highlights the proposed role of the substrate as a trigger for the switch from hemoglobin to peroxidase...
Whole chromosome aneuploidy: Big mutations drive adaptation by phenotypic leap

Despite its widespread existence, the adaptive role of aneuploidy (the abnormal state of having an unequal number of different chromosomes) has been a subject of debate. Cellular aneuploidy has been associated with enhanced resistance to stress, whereas on the organismal level it is detrimental to multicellular species. Certain aneuploid karyotypes are deleterious for specific environments, but karyotype diversity in a population potentiates adaptive evolution. To reconcile these paradoxical observations, this review distinguishes the role of aneuploidy in cellular versus organismal evolution. Further, it proposes a population genetics perspective to examine the behavior of aneuploidy on a populational versus individual level. By altering the copy number of a significant portion of the genome, aneuploidy introduces large phenotypic leaps that enable small cell populations to explore a wide phenotypic landscape, from which adaptive traits can be selected. The production of chromosome number variation can be further increased by stress- or mutation-induced chromosomal instability, fueling rapid cellular adaptation.
ET-1 receptors in C-6 cells: homologous down-regulation and modulation by protein kinase C.

Endothelin (ET-1) receptors were studied in the C-6 glia cell line. ET-1 binds to C-6 cells in a temperature- and time-dependent manner, with an apparent d of 1.16 ± 0.07 10−10 M and a Bmax of 96,500 ± 6000 sites/cell (mean ± SEM, n = 27). Stimulation of protein kinase C (PKC) with the diacylglycerol (DAG) analog phorbol 12-myristate 13-acetate (PMA) resulted in a decrease in the number of receptors in a dose-dependent manner. Inhibition of PKC with H-7 eliminated the effect of PMA on the reduction of binding sites. Treatment with exogenous 1-oleoyl-2-acetyl-sn-glycerol (OAG) and 1,2-dioctanoyl-sn-glycerol (DOG), release of endogenous DAG with phospholipase C, and inhibition of the metabolism of DAG with the diacylglycerol kinase inhibitor R 59022 also resulted in a decrease in the number of receptors. The effect of these agents was inhibited by H-7. ET-1-mediated down-regulation of receptors was also demonstrated, but the down-regulation was not affected by H-7 or by depletion of cellular PKC with chronic, high dose of PMA. Internalization constants of ET-1-receptor complex was also measured according to the model of Wiley and Cunningham (Cell 25 (1981) 433). PMA- and ET-1-mediated down-regulation of receptors was associated with an increase in the endocytosis constant for the hormone-receptor complex and a decrease in the rate of insertion of receptor into the plasma membrane. PMA, but not ET-1, increased the rate of endocytosis of unoccupied receptors. Radioiodinated ET-1 was crosslinked to the receptor after binding, extracted and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A band at 66 kDa was obtained. These studies show that ET-1 and PKC activation produce down-regulation of ET-1 membrane receptors and that ET-1-mediated down-regulation probably does not involve the activation of PKC.
Porphyrins XXXV . Exciton coupling in μ-oxo Scandum dimers

Abstract The absorption and emission spectra at room temperature and at 77 K are reported for the monomers and μ-oxo dimers of (OEP)Sc(III) and (TPP)Sc(III). [Here (OEP) is octaethylporphin and (TPP) is tetraphenylporphin.] Exciton coupling effects are strongest in the B(Soret) band of [(OEP)Sc]2O dimer: (i) The peak is blue shifted by 11 nm; (ii) the Soret band has a long red tail out to 480 mn; (iii) the fluorescence polarization shows a broad negativ band ≈ 440 nm. A vibronic exciton coupling model can roughly interpret the data if there is substantial and variable tilting of the ring planes. Exciton effects are weaker in the B(Soret) band of [(TPP)SC]2O, presumably because there is less tilting. The effect of dimer formation on the Q band of [(OEP)Scl2O is to red shift the band ≈ 420 cm−1 and to nearly double the Q(0,0) halfwidth; there is no change in fluorescence yield with dimerization. Presumably for Q bands exciton coupling is weaker than inhomogeneous broadening. Both the phosphorescence yield and triplet lifetime at 77 K drop by case2 3 in the dimer, showing faster radiationless decay.
Geometric propagation of an axially symmetric optical wavefront in a homogeneous medium

We obtain a Taylor series neighbor expansion that allows the geometric propagation of an axially symmetric wavefront in such a way that the change in shape of the wavefront is determined as an explicit function of coordinates. We then apply the expansion to the propagation of conicoids in particular. The theory is applied to the propagation of a general conicoidal, a spherical, and a paraboloidal wavefront. Application of the theory to the general conicoid leads to a proof of the invariance of the product of radius of curvature and conic constant for short propagation distances in homogeneous media. For the case of the spherical wavefront, the intuitive result is obtained (i.e. the wavefront remains spherical).
A kinetic study of the effect of Co2+, Cd2+, Cu2+ and Ni2+ on yeast inorganic pyrophosphatase

Abstract Inhibition of Mg 2+ -activated yeast inorganic pyrophosphatase by Cd 2+ , Co 2+ , Cu 2+ and Ni 2+ was studied under conditions in which the primary effect of the inhibitory metal ion was to form metal-PP 1 complexes which were competitive inhibitors of the Mg · PP 1 substrate. Inhibition constants for the binding of Cd · PP i , Cu · PP i , and Ni · PP i to the Mg 2+ -enzyme were determined. For Co · PP i , which is competitive with Mg · PP i and also slowly hydrolyzed, a Michaelis constant was determined. These parameters show that the binding of the metal-PP i complexes to the enzyme is markedly dependent on the nature of the central metal ion in the complex. Relative values of the rate constants for the hydrolysis of Co · PP i by both the Mg 2+ -enzyme and the Co 2+ -enzyme were also determined. These values were found to be within a factor of 1.6 of each other, but 7–11-fold lower than the value of the rate constant for the hydrolysis of Mg · PP i by the Mg 2+ -enzyme. This indicates, at least in comparing the Mg 2+ and Co 2+ pyrophosphatase systems, that it is the metal ion complexed to the PP i , rather than the one complexed with the enzyme, which exerts the greater effect on the rate of PP i hydrolysis.
Accurate static and dynamic properties of liquid electrolytes for Li-ion batteries from ab initio molecular dynamics.

Lithium-ion batteries have the potential to revolutionize the transportation industry, as they did for wireless communication. A judicious choice of the liquid electrolytes used in these systems is required to achieve a good balance among high-energy storage, long cycle life and stability, and fast charging. Ethylene-carbonate (EC) and propylene-carbonate (PC) are popular electrolytes. However, to date, almost all molecular-dynamics simulations of these fluids rely on classical force fields, while a complete description of the functionality of Li-ion batteries will eventually require quantum mechanics. We perform accurate ab initio molecular-dynamics simulations of ethylene- and propylene-carbonate with LiPF6 at experimental concentrations to build solvation models which explain available neutron scattering and nuclear magnetic resonance (NMR) results and to compute Li-ion solvation energies and diffusion constants. Our results suggest some similarities between the two liquids as well as some important di...
Postirradiation Effects: Monomers and Polymers

The data presented support observations that changes or reactions initiated during an irradiation exposure may continue to be operative upon the removal of the irradiation source and might be accelerated by a post-heating period. A post-irradiation effect has been demonstrated for styrene in five atmospberes, but it is more pronounced in air than it is in argon, carbon dioxide, helium, or nitrogen. The post-irradiation effects increase as the total dose increases. Cotton duck presents a more complex system but the average tensile strength in air appears to be significantly lower than that obtained in the other atmospheres. The tensile strength decreases and the loss in weight increases as the dose rate increases, but the c-samples (post-heated at 50 deg C) evidenced a smaller loss in weight than did the a-samples (processed promptly) and the b-samples (refrigerated). This is attributed to an oxygen take up and to the formation of cleavage products which have a greater moisture-retention capacity. (auth)
Interventions to prevent violence among African American adolescents from low-income communities

Violence is a public health crisis that has reached endemic proportions. African American adolescents growing up in low-income, urban communities are exposed to high rates of violence and, consequently, are at increased risk of becoming victims and perpetrators of violence. In addition to universal, population-based programs, selective interventions are needed for at risk youth, and indicated interventions are needed for youth involved in violence. This review uses ecological theory to examine the precursors of violence, with attention directed toward risk and protective factors at the individual, parent, family, and neighborhood levels. Recommendations for ecologically-oriented interventions to prevent violence among African American adolescents in low-income communities are discussed.
Host autophagic degradation and associated symbiont loss in response to heat stress in the symbiotic anemone, Aiptasia pallida

Coral bleaching involves the loss of essential photosynthetic dinoflagellates (Symbiodinium sp.) from host gastrodermal cells in response to temperature or light stress. Although numerous potential cellular bleaching mechanisms have been proposed, there remains much uncertainty regarding which cellular events occur during early breakdown of the host–dinoflagellate symbiosis. In this study, transmission electron microscopy was used to conduct a detailed examination of symbiotic tissues of the tropical anemone Aiptasia pallida during early stages of host stress. Bleaching was induced by exposing specimens to a stress treatment of 32.5±0.5°C at 140±7 μ mol photons m−2 s−1 light intensity for 12 h, followed by 12 h at 24±1°C in darkness, repeated over a 48 h period. Ultrastructural examinations revealed numerous dense autophagic structures and associated cellular degradation in tentacle tissues after ~12 h of the stress treatment. Anemones treated with rapamycin, a known autophagy inducer, exhibited the same ultrastructural characteristics as heat-stressed tissues, confirming that the structures observed during heat stress treatment were autophagic. In addition, symbionts appeared to be expelled from host cells via an apocrine-like detachment mechanism from the apical ends of autophagic gastrodermal cells. This study provides the first ultrastructural evidence of host autophagic degradation during thermal stress in a cnidarian system and also supports earlier suggestions that autophagy is an active cellular mechanism during early stages of bleaching.
Stability charts for Hill's equation

Abstract A numerical method for computing stability boundaries for Hill's equation is presented.
Human Strength as a Predictor of Lifting Capacity

A sampling of lifting capacity prediction models utilizing human strength measurements as input are presented. The models utilize isometric, isokinetic, and/or isoinertial strength measurements. Co...
Gender differences in health indicators by longest-held occupation and industry of longest employment

As more women enter the work force, they may increasingly come into contact with occupational and industrial hazards. The distribution of longest-held occupation and industry of longest employment and selected health indicators are presented for US men and women. These data are based on the National Center for Health Statistics' 1980 National Health Interview Survey, the first survey to collect data on longest-held, in addition to current, occupation and industry of employment. Data on limitation of activity, disability days, and physician and dentist visits are presented by categories of longest-held occupation and industry of longest employment. Overall, more men than women (except for younger female farm laborers and farm foremen) reported a limitation of activity due to chronic conditions; however, more women reported days of restricted activity. Female private household workers reported over a month of restricted activity. This study suggests the need to further investigate more direct health measures of female farm and agriculture workers and female private household workers.
Restauration de la masse maigre par l'administration de facteurs de croissance lors de la dénutrition sévère associée au VIH

Resume La denutrition, en particulier la perte de masse maigre (MM), est une complication frequente de l'infection par le virus de l'immunodeficience humaine (VIH). Elle est associee a une alteration de la qualite de vie, a une progression acceleree de la maladie ainsi qu'a une reduction de la survie. L'echec des traitements nutritionnels ou des stimulants de l'appetit pour restaurer de facon durable la MM a conduit a l'evaluation d'hormones stimulant specifiquement l'anabolisme proteique dans le cadre de la denutrition associee au VIH. Dans une etude metabolique a court terme, le traitement par des doses pharmacologiques d'hormone de croissance humaine recombinante (rhGH) a entraine un gain ponderal net et une augmentation de la retention azotee. De plus, dans une etude multicentrique controlee contre placebo, un apport de rhGH pendant 12 semaines entrainait un gain prolonge de poids et de MM. L'administration d' Insulin-like Growth Factor -I (IGF-I) recombinant humain, dont on pense qu'il est le mediateur des effets anabolisants proteiques de la rhGH, n'a eu qu'un effet benefique transitoire sur la balance azotee au cours d'une etude metabolique. Dans une etude multicentrique controlee contre placebo, l'association de rhIGF-I avec de faibles doses de rhGH a entraine, pour une duree d'etude comparable, une augmentation de MM representant moins de la moitie de celle obtenue avec les doses pharmacologiques de rhGH seule. Les resultats preliminaires de l'administration de testosterone et de ses derives mettent en evidence, chez les patients infectes par le VIH, une augmentation du poids et de la MM. En l'etat actuel, si on ne tient compte que des etudes controlees contre placebo et en double aveugle, seules des doses pharmacologiques de rhGH permettent d'obtenir une augmentation durable de la MM. Les etudes futures concernant l'utilisation des facteurs de croissance dans la denutrition associee au VIH devraient viser non seulement a evaluer le meilleur moyen d'administrer ces produits, mais aussi a determiner si des benefices fonctionnels significatifs sur le plan clinique vont de pair avec l'augmentation de poids et/ou de MM.
Medical student selection of otolaryngology-head and neck surgery as a specialty: influences and attitudes.

Objectives 1) To determine factors students perceive as influential in decision to pursue otolaryngology; 2) to determine perception of importance of factors used for resident selection and individual student commitment to the match; and 3) to identify exposure to various subspecialties within otolaryngology. Design Population survey. Methods A survey was administered to students applying for otolaryngology between 2000 and 2003 at a single institution. Results Ninety-six students were interviewed. Seventy-eight percent believed that the main factor influencing their decision to pursue otolaryngology was their exposure to the residents. Board scores and one-on-one interviews were important factors in selection of interviewees and ranking process. Interestingly, over 20% of students believed that the match should not be early because they wanted more time to commit to ENT. Conclusions These data underscore the importance that residents have in directing future students to our specialty. Results of the match survey may indicate an attrition rate within residency programs that may be avoided if ENT were part of the “regular” match. EBM rating C
FtsZ rings in mukB mutants with or without the Min system

Abstract The site of cell division in Escherichia coli is defined by formation of the Z ring between the two segregated daughter nucleoids. Positioning of the Z ring, composed of the highly conserved and tubulin-like FtsZ protein, appears to be negatively regulated by both the nucleoid and the oscillating MinCD inhibitor proteins. MukB protein is probably involved in nucleoid condensation, and in the absence of MukB, the negative effect of the nucleoid on Z rings appears to be partially suppressed. In this study, we examined the localization of Z rings in cells lacking both the Min system and MukB. In the Δmin ΔmukB double null mutant, essentially all nucleoid-free zones, either at the cell poles or at non-polar sites between nucleoids, contained Z rings. However, a significant proportion of Z rings also formed on top of nucleoids. Interestingly, Z ring clusters often formed at gaps between nucleoids, and some of the rings within the clusters were clearly positioned on top of nucleoids. These results provide further evidence that the negative topological effect of nucleoids in cells lacking MukB is partially but not totally suppressed, and that the absence of the Min system allows more promiscuous Z ring formation.
Si‐Composite Anode for Lithium‐Ion Batteries with High Initial Coulombic Efficiency

, which attracts significantinterest from the energy-storage research community; how-ever, its large volume change upon lithium insertion and ex-traction results in the pulverization of Si particles, very poorcycle performance, and low Coulombic efficiency, whichhinder the practical application of Si in lithium-ion batter-ies.
Friction Coefficient of an Absorbed H Atom on a Metal Surface.

The friction coefficient $\ensuremath{\eta}$ for a hydrogen adatom on a transition-metal surface is calculated in the spirit of a model proposed by Newns. $\ensuremath{\eta}$ shows variation over a wide range of values as the adatom approaches the surface. The implications of our results to catalysis are discussed and related to recent work on the subject.
NATURAL CONVECTION IN A MUSHY LAYER

Governing equations for a mushy layer are analysed in the asymptotic regime Rm [Gt ] 1, where Rm is an appropriately defined Rayleigh number. A model is proposed in which there is downward flow everywhere in the mushy layer except in and near localized chimneys, which are characterized by having zero solid fraction. Upward, convective flow within the chimneys is driven by compositional buoyancy. The radius of each chimney is determined locally by thermal balances within a boundary layer that surrounds it. Simple solutions are derived to determine the structure of the mushy layer away from the immediate vicinity of chimneys in order to demonstrate the gross effects of convection upon the solidification within the layer.
Optic Chiasmatic Glioma in Children

We reviewed the records of 29 patients with optic nerve or chiasm glioma, or both, seen from 1955 to 1966. Sixteen patients were girls and 13 were boys. At the time of diagnosis, 14 patients were less than 2 years old. Optic atrophy was the most frequently seen physical finding, present in 26 of 29 patients. Twelve patients had diencephalic syndrome (41%). Proptosis was seen in eight. Eleven patients (38%) had associated neurofibromatosis. Pneumoencaphalogram was done on 26 patients and was abnormal in 23. The diagnosis was confirmed at surgery in 27 patients. All tumors were astrocytomas. Eighteen patients underwent radiotherapy. Surgery and radiotherapy were used as treatment for optic-chiasmatic glioma with diencephalic syndrome.
Reflective Thinking and Growth in Novices' Teaching Abilities.

Abstract Despite considerable differences in interpretations and agendas, reflective teaching programs are governed by the assumption that thoughtful and critically questioning novices will develop expertise in teaching abilities. However, there is no reported research that specifically examines prospective teachers' reflective thoughts in relation to improvement in teaching. This study examined the relationship between future teachers' reflections and growth in their teaching abilities in an early field placement. Data gathered over one semester from reflective journals and multiple observations were analyzed and descriptive statistics included. Results suggest that teacher preparation programs should foster reflective thinking as an important facet of growth in teaching abilities.
Recent advances in photorefractive polymer materials

This paper summarizes current research to develop photorefractive polymeric materials with improved speed, material stability, and high beam coupling gain. The recent demonstration of significantly improved two-beam coupling marks the entry into a gain regime which enables the observation of new effects for the first time, such as beam fanning and self-pumped phase-conjugation. These effects have previously been observed only in a few thick high gain inorganic photorefractive crystals. The large beam coupling forces the reinterpretation of such traditional characterization techniques such as the grating translation method for the determination of the spatial phase of the index grating. Our subsequent material study focuses on several compositional variations to investigate the effect on the photorefractive performance of varying the chromophore and charge transporting polymer.
Kinetic model for the mechanical properties of polymer glasses

The deformation behaviour and the mechanical properties of polymer glasses are studied with the help of a kinetic model introduced previously. The model, which is based on the Eyring chemical activation rate theory, takes into account the role of the strong attractive forces between macromolecular chains as well as chain slippage through entanglements. Application to poly(methyl methacrylate) has allowed us to calculate the yield stress, craze length and fracture toughness and their dependence on testing conditions. The model also clearly illustrates the transition from crazing to shear yielding in polymer glasses as the density of entanglements is increased.