cssi/SciSciGPT-SciSciNet huggingface dataset:
Computational and experimental prediction of dust production in pebble bed reactors, Part II

This paper describes the computational modeling and simulation, and experimental testing of graphite moderators in frictional contacts as anticipated in a pebble bed reactor. The potential of carbonaceous particulate generation due to frictional contact at the surface of pebbles and the ensuing entrainment and transport into the gas coolant are safety concerns at elevated temperatures under accident scenarios such as air ingress in the high temperature gas-cooled reactor. The safety concerns are due to the documented ability of carbonaceous particulates to adsorb fission products and transport them in the primary circuit of the pebble bed reactor, thus potentially giving rise to a relevant source term under accident scenarios. Here, a finite element approach is implemented to develop a nonlinear wear model in air environment. In this model, material wear coefficient is related to the changes in asperity height during wear. The present work reports a comparison between the finite element simulations and the experimental results obtained using a custom-designed tribometer. The experimental and computational results are used to estimate the quantity of nuclear grade graphite dust produced from a typical anticipated configuration. In Part II, results from a helium environment at higher temperatures and pressures are experimentally studied.
Water supply and sanitation of Costa Rica

Costa Rica is a developing country whose citizens pride themselves on care for the environment. Environmental care is only slowly spreading to include safe and reliable water supplies. Plentiful water resources are used for energy production, industry, municipal water supply, and agriculture. The amount and quality of water resources must be understood and protected for future sustainable use. Based on interviews and conversations, some Costarricense are aware of the need for protection of natural water resources through preservation of forests; other steps toward sustainable water use are not universally valued. Streams are not the preferred source of domestic water supply due to potential water contamination; mostly from untreated sewage, sediment and agricultural chemicals. Quantity and quality of ground water supplies, the current main source of domestic water, are being investigated by scientists of Costa Rica. While 99 % of the population has access to a known supply of domestic water, only 82 % of the population has consistent access to potable drinking water. The potable water supply is smaller in rural areas. Three percent of sewage in Costa Rica is treated before release to the environment. The Rio Tarcoles water basin, underlying the largest urban area of Costa Rica, is probably the most polluted in Central America. More is spent for treatment of water-borne diseases than on water supply and sewage treatment. Other potential sources of water contamination are examined.
Endocrine and other responses to acute administration of cannabinoid compounds to non-stressed male calves.

Abstract There is an abundance of cannabinoid (CB) receptors for derivatives of cannabis plants in the brain and throughout the body, and several naturally occurring arachidonic acid derivatives can activate these receptors. The specific objective of this study was to activate these CB receptors in castrated male calves through administration of several CB agonists and to measure immediate changes in concentrations of several serum hormones, respiration rate, and sensitivity to pain. The rationale for the study was that exogenous activation of CB receptors might reveal whether the endogenous CB system (consisting of receptors and endogenous ligands) plays a role in the stress response of animals and specifically whether the activated CB system might be part of a coping mechanism to combat stress. Intravenous administration of three CB agonists (anandamide, methanandamide and WIN 55212-2) to nine castrated male calves under nonstress conditions provoked immediate increases of serum cortisol and respiration rate as well as rapidly caused hypoalgesia to cutaneous pain and thermal stimuli. Although anandamide and methanandamide did not affect serum prolactin, administration of another CB agonist (WIN 55212-2) did increase serum prolactin abruptly. None of the CB agonists affected serum growth hormone. In summary, many of the changes following administration of CB agonists were similar to a stress response in this species, but there were some agonist-specific differences, notably regarding prolactin secretion, as well as differences between calves and observations made in other species. Although CB receptors in calves may be activated by endogenous ligands during exposure to some stressors, the present results are also consistent with this CB system being part of a coping mechanism that helps animals deal with imposed stressors.
Inhibition of growth of leukemic cells by inhibitors of calmodulin: Phenothiazines and melittin

Calmodulin, a ubiquitous calcium-binding protein, has recently been shown to play an important role in cellular proliferation. The calmodulin inhibitors melittin, trifluoperazine, and chlorpromazine inhibited the growth and clonogenicity of human and murine leukemic cells, and their potency reflected their activity as inhibitors of calmodulin. Melittin, which is a far more potent inhibitor of calmodulin activity, was also a more potent inhibitor of cell growth and clonogenicity. The less active phenothiazine metabolite, chlorpromazine sulfoxide, had much less potent cytotoxic activity.
Experimental modeling of intergranular exchange coupling for perpendicular thin film media

We present an experimental model system that enables quantitative assessment of intergranular exchange coupling in CoCrPt-oxide perpendicular magnetic recording media. A thin film structure consisting of a high coercivity CoPt unicrystal layer and a lower coercivity CoPt layer separated by a thin oxide interlayer is used to model perpendicularly magnetized grains separated by oxide grain boundaries. Exchange coupling energy between the CoPt layers was obtained for SiOx, TiOx, and CrOx interlayers by measuring field shifts from the lower coercivity layer. Cr segregation in CoCrPt grains to grain boundaries is also modeled experimentally and found to significantly suppress exchange coupling.
Penicillin-resistant Streptococcus mitis as a cause of septicemia with meningitis in febrile neutropenic children.

Purpose The purpose of this report is to emphasize the importance of occurrence of Streptococcus mitis meningitis in febrile neutropenic children with hematopoietic malignancy. Patients and methods Symptoms of meningitis and sepsis (fever, headache, changes in mental status) were seen in three patients who were severely neutropenic and undergoing cytotoxic chemotherapy for CNS relapse of their underlying malignancy (acute lymphoblastic leukemia (ALL), n = 2; Burkitt's lymphoma, n = 1). Chemotherapy had included cytosine arabinoside administered 7-14 days prior to presenting with sepsis and meningitis. All three patients had buccal mucositis or sinusitis. Blood cultures and CSF cultures showed S. mitis resistant to penicillin but sensitive to vancomycin. Vancomycin, at a dosage of 60 mg/kg/day to maximize CNS levels of antibiotic, was administered to all three children. Results Two of the patients recovered from S. mitis meningitis; recovery was associated with an improvement in their peripheral granulocyte counts. One patient, who remained neutropenic, died despite being treated with both intravenous and intraventricular vancomycin. Conclusion Physicians caring for patients who are neutropenic and febrile need to be aware of the risk of meningitis occurring with S. mitis sepsis. Early treatment with high dosages of vancomycin (60 mg/kg/day) and an attempt to limit the duration of neutropenia are important factors in the outcome of such patients.
Observation of pendellösung fringes in reflection-section topographs of bent silicon crystals

Abstract Pendellosung fringes have been observed in reflection-section topographs of bent silicon single crystals. The number of fringes increases while the separation distances between fringes decrease with decreasing radius of curvature. Excessive bending of the lattice planes adjacent to a dislocation produces finer fringes. These fringes may be employed as a means to detect minute lattice strains.
The hydrothermal transformation rate of kaolinite to muscovite/illite

Batch reactor experiments were performed to measure the rate of the reaction 1.5 kaolinite + K+ = muscovite + H+ + 1.5 water at temperatures ranging from 250 to 307°C. In these experiments, the rate of kaolinite conversion to muscovite/illite was monitored as the rate of production of H+. Runs were performed in small volume (50 mL) titanium hydrothermal reactors charged with well-crystallized Georgia kaolinite, Indian Ruby muscovite, and 25 mL of KCl solution (0.5–2.0 m). Both solids and solutions were monitored at specific intervals throughout each experiment. The determined rate law is dmH+dt=-dmK+dt=AmM(k+MK+− k_mh+ where mk++ and mH+ are the concentrations of potassium ion and hydrogen ion, k+ and k− are the forward and reverse rate constants in kg m−2 sec−1, Am is the total surface area of the muscovite in m2, and M is the mass of the solution in kg. The initial rate method was used to find k+, and k− was found by fitting data to an integrated rate equation. Temperature functions for the rate constants are In k+ = 12.90 − ( 1.87 × 104/T), R2 = 0.98, and In k− = 6.03 − ( 1.21 × 104/T), R2 = 0.95. The activation energies (Ea) for the forward and reverse reaction are 155 ± 15 kJ mol−1 and 101 ± 10 kJ mol−1, respectively.
Natural soiling of photovoltaic cover plates and the impact on transmission

Abstract Photovoltaic (PV) and other solar energy systems are known to lose efficiency as a result of the accumulation of dust on the surface of the panels. These losses have been difficult to predict and vary widely across geographical regions. In this work dust is allowed to naturally accumulate on PV cover plates at two sites in the Front Range of Colorado. Mass accumulation rates are measured, as well as light transmission reduction. Mass accumulation rates between 1 and 50 mg/m 2 /day were observed and varied with time of year, location, and angle of deployment. Total mass accumulations up to 2 g/m 2 were observed after 1–5 week deployments. Transmission reductions up to 11% were found. Transmission varied linearly with the mass of dust accumulated and it was not affected by the angle of incidence of incoming irradiance, angle of deployment of the panel, or location of deployment. Light transmission was found to be reduced by 4.1% for every g/m 2 of dust accumulated on the PV cover plate; this relationship was derived from a linear regression of the data. A linear fit to the data is shown to be sufficient, and the uncertainties of the measurements and calculations are found.
Myofibroblastoma of the larynx: A study of two cases

Background. We describe, for the first time, the occurrence of two pure examples of spindle cell neoplasm with fibrous and smooth muscle differentiation in the larynx. Materials and Method. Tissue sections from both tumors stained with hematoxylin and eosin were reviewed. Immunophenotypic analysis using keratin, S-100 protein, SMA, and h-Caldesmon markers was performed. Results. Tumors were seen as raised submucosal nodules in the glottic region of two elderly male patients. Histopathologically, the lesions were unencapsulated and composed of spindle cells that manifested variable cellular anaplasia and expressed SMA and were negative for keratin, S-100, and h-Caldesmon. Conclusions. We document histologically low-grade malignant myofibroblastic tumors of the larynx. Complete excision is advised. © 2003 Wiley Periodicals, Inc. Head Neck 25: 606–611, 2003
Advising patients about international travel. What they can do to protect their health and safety.

PREVIEWMontezuma's revenge is only one of the many potential hazards affecting international travelers. Long airline flights and exposure to unfamiliar environments, new infectious diseases, emergency situations, or criminal encounters can threaten travelers' health and safety. With adequate preparation, however, travelers can reduce their risk of illness and injury. In this comprehensive review, Dr Bratton discusses the many hazards of international travel and offers advice about what to tell your patients before they go.
Atmospheric wave propagation in heterogeneous flow: basic flow controls on tropical—extratropical interaction and equatorial wave modification

Abstract It is noted that wave propagation in the atmosphere and error propagation in numerical models appear to have preferred geographical loci. However, these paths appear to be more associated with the low frequency background state of the atmosphere than the location of the wave source. Theoretical and numerical models are used to determine the control the basic state has on wave propagation both between the extratropica and the tropics (and vice versa) and within the tropics. Basic states with horizontal and vertical shear as well as longitudinal stretching deformation are studied. It is shown that strong horizontal shear embedded in equatorial easterlies confines modes close to the equator. Weak shear in westerly tropical flow allows modes to project into the extratropics. That is, the degree of equatorial trapping is diminished. Negative stretching deformation acts to trap modes longitudinally so that the western sides of the westerly ducts are accumulation regions. Negative vertical shear inhibits vertical propagation while positive shear enhances propagation. It is concluded that the basic state is the determining factor in the observed patterns of waves and the locations of errors in numerical weather prediction and climate models. Of particular interest are the westerly duct regions of the eastern Pacific Ocean and the Atlantic Ocean. These regions appear to act as wave attractors for both equatorially trapped modes and extratropical modes propagating towards the equator and also are regions of enhanced vertical propagation.
The use of recombinant activated factor VII in three patients with central nervous system hemorrhages associated with factor VII deficiency

BACKGROUND: Recombinant activated factor VII (rFVIIa) is being tested to improve hemostasis in a variety of bleeding disorders. Clinical indications and efficacy are still being evaluated for this product. CASE REPORT: Over a 17-month period, rFVIIa was used to treat central nervous system hemorrhage in three patients who were found to have isolated FVII deficiency (21%, 40%, 27%). Patient A fell 30 feet, Patient B suffered a motor vehicle accident, and Patient C had a spinal cord hematoma. None of the patients had a history of bleeding diathesis. All three patients received rFVIIa after failing initial treatment with fresh-frozen plasma. RESULTS: Patient A was treated with 11 doses (initial dose 95 µg/kg; subsequent doses 8-38 µg/kg) over 10 days; Patient B received 13 doses (45-60 µg/kg) over 13 days; and Patient C received 5 doses (12-24 µg/kg) over 4 days. The prothrombin time corrected from 16.2 ± 1.8 (mean ± SD) to 11.2 ± 1.6 seconds after infusion of rFVIIa, but returned to pretreatment level in 14 ± 4 hours. At the cessation of therapy, all patients showed neurologic improvement. No complications related to the infusion of rFVIIa occurred. CONCLUSION: The use of rFVIIa may be of value both for its general effect on hemostasis, and specifically in the setting where there is a documented reduction in FVII. Doses lower than those used in patients with FVIII inhibitors appear to be effective in the setting of central nervous sytem hemorrhage.
Three dimensional modelling and numerical analysis of super-radiant harmonic emission in an FEL (optical klystron)

Abstract A full 3-D analysis of super-radiant (bunched electron) free electron harmonic radiation is presented. A generalized form of the FEL pendulum equation was derived and numerically solved. Both spectral and phasor formulation were developed to treat the radiation in the time domain. In space the radiation field is expanded in terms of either a set of free space discrete modes or plane waves. The numerical solutions reveal some new distinctly 3-D effects to which we provide a physical explanation.
Influence of sucrose on the mutarotation velocity of lactose.

Abstract The kinetics of mutarotation of lactose in the presence of sucrose was determined at 25, 30 and 35C. The rate of mutarotation of lactose decreased slightly by sucrose added to 40% and thereafter greatly decreased. Increasing sucrose from 30 to 60g per 100ml solution, decreased the velocity constant 1.8 to 1.9 times, independent of the concentration of lactose. In a whey-salt solution, mutarotation was increased 1.8 to 1.9 times. With sucrose the whey-salt solution did not increase the rate constant and mutarotation rates were then essentially the same as in distilled water. Increasing sucrose decreased mutarotation constants in the whey-salt solution as in distilled water. Effect of sucrose was apparent at 25g per 100ml solution. Potassium dihydrogen phosphate, Na 3 -citrate, and K 3 -citrate catalyzed the mutarotation velocity of lactose, did not increase the rate constant with 30g sucrose per 100ml solution.
Molybdenum(V) on an Oxide String. Synthesis and Structure of the Novel Linear Trinuclear Complex {[MoO(TPP)][O−Mo(TPP)−O][MoO(TPP)]}ClO4

The syntheses and crystallographic characterization of the linear trinuclear complex [Mo3O4(TPP)3]ClO4 and the monomeric precursors [MoO(TPP)(OClO3)] and [MoO(TPP)(OH2)]ClO4 are described. The crystallographic analyses of [MoO(TPP)(OClO3)] and [MoO(TPP)(OH2)]ClO4 show that these similar complexes are typical oxomolybdenum(V)−porphyrin complexes whose only significant structural differences are related to their respective axial ligands. [Mo3O4(TPP)3]ClO4 is obtained by the controlled hydrolysis of [MoO(TPP)(OClO3)] or by the direct reaction of [MoO(TPP)(OClO3)] with {[MoO(TPP)]2O}. This hydrolysis product contains the novel [Mo3O4(TPP)3]+ ion, which has an unprecedented linear [OMo−O−Mo−O−MoO]7+ unit and three nearly parallel 24-atom porphyrin mean planes. The central porphyrin is found to be rotated 29.3° and 29.7° with respect to the two terminal porphyrin ligands, which are nearly eclipsed (twist angle 0.44°). The formation of [Mo3O4(TPP)3]ClO4 instead of the μ-hydroxo-bridged binuclear complexes obtain...
High-speed camera study of Stage III crack propagation in chemically strengthened glass

Thermally or chemically strengthened glass is more resistant to damage and breakage compared to non-strengthened glass. Both strengthening mechanisms are based on incorporation of a compressive stress profile in the surface of the glass, which must be balanced by an equivalent amount of integrated tensile stress in the interior of the glass. This tensile stress is believed to affect the kinetics of Stage III crack propagation upon fracture of the sample. In this study, we use a high-speed camera to perform direct measurement of the kinetics of Stage III fracture in a strengthened glass sample. Data including crack propagation speed, crack bifurcation distance, and bifurcation angles are collected at a rate of 500,000 frames per second and then characterized. The authors believe that these data will provide a foundation for understanding the physics of Stage III fracture in strengthened glass samples.
Multi-Material ALE methods in unstructured grids

Arbitrary Lagrangian Eulerian (ALE) methods have existed for several decades. However, three-dimensional Multi-Material Arbitrary Lagrangian Eulerian (MMALE) methods for unstructured grids are relatively new. MMALE algorithms provide the framework to model sections of a simulation as either Lagrangian, ALE, or Eulerian. In addition, sections of a simulation can switch in time between mesh motions as the distortion of the problem dictates. The MMALE method provides the accuracy of Lagrangian mesh motion and the robustness of Eulerian mesh motion within the same framework. Extending this method to unstructured grids allows for more accurate representation of curved surfaces and complex geometries. This paper examines the algorithms required for the MMALE method and the extensions to these algorithms for unstructured meshes. In addition, second-order behavior of the MMALE algorithm as it exists in the high energy density physics code Arbitrary Lagrangian Eulerian General Research Applications code (ALEGRA) is demonstrated, along with a practical example of its usefulness.
Coevolution of auditory sensitivity and temporal resolution with acoustic signal space in three songbirds

Coevolution between senders and receivers is expected to produce a close match between signal design and sensory biology. We evaluated this hypothesis in songbirds by comparing aspects of acoustic signal space with the frequency range of auditory sensitivity and temporal resolution in tufted titmice, Baeolophus bicolor ; house sparrows, Passer domesticus ; and white-breasted nuthatches, Sitta carolinensis . Auditory measurements were made electrophysiologically from the scalp using two classes of auditory-evoked potentials: the auditory brain-stem response (ABR) and the envelope-following response (EFR). ABRs to tone-burst stimuli indicated maximum sensitivity from 2.2 to 3.2 kHz in all species, but 12–14 dB greater sensitivity in titmice than in sparrows and nuthatches at 6.4 kHz (the highest frequency tested). Modulation rate transfer functions based on EFRs to amplitude-modulated tones suggested greater temporal resolution in titmice and sparrows than in nuthatches. Conservation of the frequency range of maximum sensitivity across species resulted in a mismatch with the dominant frequency of song in sparrows. The mismatch may reflect auditory constraints coupled with selection for high-frequency song and relaxed selection for a close match between sender and receiver due to small territory size. Consistent with coevolution between senders and receivers, high-frequency sensitivity varied with the maximum frequency of species-specific vocalizations, whereas temporal resolution varied with the maximum rate of envelope periodicity. Enhanced high-frequency sensitivity of the titmouse may reflect a specialization for processing high-frequency communication signals such as alarm calls.
The effect of folic acid on glycine toxicity in the chick.

Abstract Studies were conducted to determine the effect of folic acid and vitamin B 12 on glycine toxicity. Folic acid was found effective in reversing the toxic effects of glycine. Folic acid determinations on the livers of chicks receiving glycine indicate an increased storage of the vitamin. The total creatinine content of blood, muscle, and liver is higher in folic acid-deficient birds. The possible significance of these results is discussed.
On the stochastic Beverton–Holt equation with survival rates

The paper studies a Beverton–Holt difference equation, in which both the recruitment function and the survival rate vary randomly. It is then shown that there is a unique invariant density, which is asymptotically stable. Moreover, a basic theory for random mean almost periodic sequence on is given. Then, some sufficient conditions for the existence of a mean almost periodic solution to the stochastic Beverton–Holt equation are given.
Low p53 level in immortal, non-tumorigenic oral keratinocytes harboring HPV-16 DNA.

Abstract The p53 protein level was determined in normal oral keratinocytes and two non-tumorigenic, immortal oral keratinocyte lines harboring human papillomavirus-16 (HPV-16)DNA. The p53 mRNA level in the immortal cells was higher than the normal counterpart, but the p53 protein level was notably lower in the immortalised cells. The half-life of p53 protein in the normal and immortal cells was E6 E7 mRNA encoded by HPV-16, but normal cells did not. These observations suggest that the immortal keratinocytes may translate normal level of wild-type p53 protein, and the low p53 level in these cells may be due to the enhanced degradation of the protein by HPV-16 E6 protein.
Recreation as Socialization for the Homeless: An Argument for Inclusion

Abstract Each homeless subpopulation has special characteristics which identify their particular needs and directs any attempts at program development. This article describes the unique traits of each subpopulation and makes recommendations for recreational programs which reflect the special characteristics of the homeless.
Determination of scan-plane motion using speckle decorrelation: Theoretical considerations and initial test

The correlation function of the echo signal intensities at a fixed region on a series of B-mode images is directly related to the change of speckle patterns between these images. An indication is given here of how the rate of the change of that correlation function can be used to estimate the scan-plane motion in any direction relative to the imaged tissue or other material. In this first implementation it is assumed that the statistical properties of the echo signals follow those of a complex circular Gaussian, and the case is considered of diffusely scattering tissue with many fine particles per resolution cell and with no phase distortion. The method is applied to data from a one-dimensional linear array and initial results are presented for scanning a tissue-mimicking phantom in the elevational direction of the transducer. Experimental results are in good agreement with the predictions. The current method should provide a good indication of the local rate of scan-head motion in those tissues in which the normalized correlation function of the echo signal intensities behaves, or can be made to behave, as it would for a medium with uniform acoustic properties and containing many, randomly distributed, pointlike scatterers, although application might be made to other situations where a deterministic condition exists for the correlation between images taken at differing locations within a volume. © 1997 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 8, 38–44, 1997
Nickel dithiolenes revisited: structures and electron distribution from density functional theory for the three-member electron-transfer series [Ni(S2C2Me2)2]0,1-,2-.

The complexes [Ni(S2C2Me2)2]z (z = 0, 1−, 2−) have been isolated for the purpose of investigating their electronic structures in a reversible three-member electron-transfer series. Members are interrelated by reversible redox reactions with E1/2(0/1−) = −0.15 V and E1/2(1−/2−) = −1.05 V versus SCE in acetonitrile. The three complexes have nearly planar structures of idealized D2h symmetry. As the series is traversed in the reducing direction, Ni−S and C−S bond lengths increase; the chelate ring C−C bond length decreases from the neutral complex to the monoanion and does not change significantly in the dianion. Structural trends are compared with previous results for [Ni(S2C2R2)2]1-,2-. Following the geometrical changes, values of νNi-S and νC-S decrease, while the value of νC-C increases with increased reduction. Geometry optimizations at the density functional theory (DFT) level were performed for all members of the series. Geometrical parameters obtained from the calculations are in good agreement with ...
Isoprene, an endogenous constituent of human alveolar air with a diurnal pattern of excretion.

Abstract A volatile organic component in the alveolar air of man consistently detected by gas chromatography was identified as isoprene (2-methyl-1, 3-butadiene). The identification was based on chemical reactivity of this substance, gas chromatography-mass spectrometric analysis, and comparison of the gas chromatographic retention times of eight C5H8 isomers. In adult subjects, eleven females and fourteen males, the concentrations of isoprene in alveolar air collected between 0500 and 0800 hours were 28.4 ± 12.3 and 28.3 ± 7.4 (S.D.) nmoles/liter, respectively. No significant differences were apparent on the basis of either sex or age. A diurnal rhythm was observed with the isoprene levels peaking at 0600 hours followed by a trough at 1800 hours.
Neurodynamics of learning and network performance

A simple dynamic model of a neural network is presented. Using the dynamic model of a neural network, we improve the performance of a three-layer multilayer perceptron (MLP). The dynamic model of a MLP is used to make fundamental changes in the network optimization strategy. These changes are: Neuron activation functions are used, which reduce the probability of singular Jacobians; Successive regularization is used to constrain the volume of the weight space being minimized; Boltzmann pruning is used to constrain the dimension of the weight space; and prior class probabilities are used to normalize all error calculations, so that statistically significant samples of rare but important classes can be included without distortion of the error surface. All four of these changes are made in the inner loop of a conjugate gradient optimization iteration and are intended to simplify the training dynamics ofthe optimization. On handprinted digits and fingerprint classification problems, these modifications improve error-reject performance by factors between 2 and 4 and reduce network size by 40 to 60%.
Privileged structure-based ligands for melanocortin receptors—tetrahydroquinolines, indoles, and aminotetralines

Substitution of the aryl sulfonamide moiety contained in MC4 agonist 1 with bicyclic heterocycles and aminotetralines produced compounds with MC4 activity. The heterocycles represent alternative privileged structures to that contained in 1. Compounds in which the polar group of the privileged structure was displayed in an endocyclic fashion were not as active as the parent agonist 1, while those with an exocyclic polar group afforded activity competitive with 1.
Racism-related stress, Africultural coping, and religious problem-solving among African Americans

This study explored the extent to which three types of racism-related stress (i.e., individual, institutional, and cultural) would predict the use of specific Africultural coping strategies (i.e., cognitive/emotional debriefing, spiritual-centered, collective, and ritual-centered coping) and religious problem-solving styles (i.e., self-directing, deferring, and collaborative) in a sample of 284 African American men and women. The authors found that higher institutional racism-related stress was associated with greater use of cognitive/emotional debriefing, spiritual-centered, and collective coping in African American women. Findings also indicated that higher cultural racism-related stress was predictive of lower use of self-directing religious problem-solving in African American women. Moreover, higher perceived cultural racism-related stress was related to greater use of collective coping strategies in African American men. Individual racism-related stress was not predictive of any forms of Africultural coping strategies or religious problem-solving. Implications of the findings are discussed.
Problem of Ghost States in Field Theories

It is shown that the ghost problem in the Lee model cannot be circumvented by using a renormalized integral equation as a basis instead of the Hamiltonian formulation. This equation (the Low equation) possesses no solutions for coupling constants larger than the critical value, and an infinite family of solutions for coupling constants smaller than the critical value. The Low equation for the Lee model is also mathematically equivalent to an exact integral equation for the boson propagator in relativistic field theory, and permits one therefore to describe the properties of possible ghosts in a relativistic theory in terms of already known properties of Lee-model ghosts. There exists an interesting symmetry between this integral equation and its solution, both of which have the form of dispersion relations. The excellent experimental tests of quantum electrodynamics provide no evidence that the theory is free of the ghost problem.
Modeling recursive RNA interference.

An important application of the RNA interference (RNAi) pathway is its use as a small RNA-based regulatory system commonly exploited to suppress expression of target genes to test their function in vivo. In several published experiments, RNAi has been used to inactivate components of the RNAi pathway itself, a procedure termed recursive RNAi in this report. The theoretical basis of recursive RNAi is unclear since the procedure could potentially be self-defeating, and in practice the effectiveness of recursive RNAi in published experiments is highly variable. A mathematical model for recursive RNAi was developed and used to investigate the range of conditions under which the procedure should be effective. The model predicts that the effectiveness of recursive RNAi is strongly dependent on the efficacy of RNAi at knocking down target gene expression. This efficacy is known to vary highly between different cell types, and comparison of the model predictions to published experimental data suggests that variation in RNAi efficacy may be the main cause of discrepancies between published recursive RNAi experiments in different organisms. The model suggests potential ways to optimize the effectiveness of recursive RNAi both for screening of RNAi components as well as for improved temporal control of gene expression in switch off–switch on experiments.
The effect of presenting multiple images on prospective and retrospective person memory for missing children

Abstract The National Center for Missing and Exploited Children sometimes present multiple images of the same child on missing-child posters. In the present research, we examined the effect of including multiple pictures of missing children on posters in the context of both prospective and retrospective person memory. Improvements in both prospective person memory and retrospective person memory were obtained in the multiple-image condition. Additionally, in retrospective person memory, participants who were presented with multiple-image posters showed an increased tendency to indicate that a child was previously seen regardless of whether the child actually was previously seen. We discuss these findings as well as policy implications of these results.
Diffusion bonding of NiZn ferrite and nonmagnetic materials

Diffusion bonding of dissimilar ceramics can be accomplished by the application of pressure only while the ceramics are at a temperature where their respective thermal expansion curves cross. A process for manufacturing magnetic head cores is disclosed wnere a NiZn ferrite is bonded by diffusion co a nonmagnetic ceramic by heating the core pieces to the crossover temperature and them applying the bonding pressure. The pressure can be removed either before or after the bonded pieces are cooled.
Fleet-sizing and service availability for a vehicle rental system via closed queueing networks

Abstract In this paper, we address the problem of determining the optimal fleet size for a vehicle rental company and derive analytical results for its relationship to vehicle availability at each rental station in the company’s network of locations. This work is motivated by the recent surge in interest for bicycle and electric car sharing systems, one example being the French program Velib (2010) . We first formulate a closed queueing network model of the system, obtained by viewing the system from the vehicle’s perspective. Using this framework, we are able to derive the asymptotic behavior of vehicle availability at an arbitrary rental station with respect to fleet size. These results allow us to analyze imbalances in the system and propose some basic principles for the design of system balancing methods. We then develop a profit-maximizing optimization problem for determining optimal fleet size. The large-scale nature of real-world systems results in computational difficulties in obtaining this exact solution, and so we provide an approximate formulation that is easier to solve and which becomes exact as the fleet size becomes large. To illustrate our findings and validate our solution methods, we provide numerical results on some sample networks.
Parallel-vector solution of large-scale structural analysis problems on supercomputers

A direct linear equation solution method based on the Choleski factorization procedure is presented which exploits both parallel and vector features of supercomputers. The new equation solver is described, and its performance is evaluated by solving structural analysis problems on three high-performance computers. The method has been implemented using Force, a generic parallel FORTRAN language.
Atomic force microscopy based repeatable surface nanomachining for nanochannels on silicon substrates

Abstract The atomic force microscopy (AFM)-based repeatable nanomachining for nanochannels on bare silicon surfaces is investigated experimentally for automated nano manufacturing applications. The relationship between the normal force applied on the AFM cantilever and the channel depth is established and analyzed using both linear and logarithmic fits. Thus, current results can be regarded as the calibration reference in order to accurately predict the nanochannel depth for additional nanotechnology related applications. An accurate prediction of the depth is not only for accuracy and efficiency, but also to prevent a costly diamond tip from unnecessary wear and tear. Furthermore, the experimental results also reveal that the fabrication procedure is repeatable.
Signal-to-noise ratios in IUE low-dispersion spectra. II: Photometrically corrected images

Photometrically corrected images from the IUE's two intensified vidicon cameras are used to explore the character of detector noise, and a protocol for the derivation of realistic noise models is proposed on the basis of available collections of UV-Flood calibration images. The incomplete removal of the pixel-to-pixel sensitivity pattern can lead to a factor-of-2 enhancement in apparent noise; even with good suppression of pixel granularity, the remaining random noise can exhibit saturation behavior which causes S/N to cease improving with increasing exposure. When all relevant effects are considered, underlying, 'pristine' noise models show virtually no dependence on spatial position.
Parallel graph algorithms that are efficient on average

The following three problems concerning random graphs can be solved in (log n)O(1) expected time using linearly many processors: (1) finding the lexicographically first maximal independent set, (2) coloring the vertices using a number of colors that is almost surely within twice the chromatic number, and (3) finding a Hamiltonian circuit.
A Man-Made Disaster: The Earthquake of January 12, 2010— A Haitian Perspective:

The earthquake of January 12, 2010, was not the first, nor will it be the last, to hit Haiti, a volcanic land traumatized by natural and man-made disasters from its beginning as a colony and sovereign nation. In the throes of rein-venting itself politically, socially, and culturally since the overthrow of the Duvalier dictatorship, 1957-1986, Haiti now has to reinvent itself physically. Are there bounds to the Haitians’ vaunted resilience? The author proposes to examine the aftermath of the "Goudougoudou," as Haitians now call the event, relating it to other events that have taxed Haitian resolve over the course of two centuries.
MSG1 and its related protein MRG1 share a transcription activating domain.

Abstract MSG1 is a recently described melanocyte-specific nuclear protein whose biochemical function is unknown [Shioda et al. (1996) Proc. Natl. Acad. Sci. USA 93, 12298–12303]. Two human cDNA sequences found in the EST (expressed sequence tag) database were predicted to encode a small peptide (45 aa) that showed 69% identity to the C-terminal sequence of MSG1, suggesting the existence of a novel MSG1-related protein. Based on these EST sequences, we isolated a novel gene, MRG1 ( MSG1 -Related Gene 1), by the 5′-RACE (rapid amplification of cDNA ends) technique. The MRG1 mRNA transcript is expressed widely and encodes a nuclear protein that share two highly conserved domains, CR1 (14 aa) and CR2 (approx. 50 aa), with MSG1. The CR2 domain is significantly acidic and activates transcription in yeast cells. The full-length MSG1 and MRG1 fused to GAL4 DNA-binding domain activates transcription in mammalian cells, and this is dependent on the presence of the CR2 domain. These results suggest that MRG1 and MSG1 may function as transcription activators.
Neuronal and neurovascular integration following transplantation of the fetal hypothalamus into the third cerebral ventricle of adult brattleboro rats. Neurological transplants: I

Abstract This investigation has confronted some very basic questions of neurobiology and specifically deals with the neurovascular and neuroanatomical interactions that occur between graft and host following neural transplantation. Host Long-Evans rats with chronic autosomal diabetes insipidus (DI) received stereotaxic implants of normal 17 day post-coitus fetal hypothalamic fragments from the rostral (anterior) hypothalamus of normal Long-Evans pups. Following stereotaxic surgery DI hosts were killed 60 or 90 days later and their brain prepared for correlative microangiography-immunocytochemistry coupled with transmission electron microscopy. Explants were rapidly invaded by host vessels from several routes. 1. (1) Vessels appeared to arise from portal capillaries in the underlying median eminence and 2. (2) from adjacent vessels from the paraventricular nucleus and surrounding endocrine hypothalamus and 3. (3) possibly from intrinsic vessels of the graft. The former remained fenestrated and established bonafide neurovascular zones in the ventral regions and in actively growing explants. Small clusters of arginine vasopressin-positive fibers and neurophysin positive neurons were noted throughout the parenchyma of explants. Despite the presence of neurosecretory neurons and neurovascular (neurohemal) zones, none of the host rats exhibited a physiological return to normal parameters of water balance. However the active growth and development of explants in the third cerebral ventricle of DI host rats coupled with emergence of neurovascular zones lends support to a potential model for analyzing the development of anatomical substrates for the central delivery of neuropeptide hormones.
Neonatal herpes in premature infants: a special problem.

The study by O'Riordan et al1 in this issue of Pediatrics focuses our attention on the special problem of herpes simplex virus (HSV) infections in premature infants. We recognize the deadly and complex nature of neonatal herpes, thanks to an exceptional body of work by Whitley, Arvin, Prober, Kimberlin, Nahmias, Corey, Brown, and other luminaries. Their research has established the role of mother-to-infant transmission in most cases.2 This body of work has clarified that most mothers of infected infants have no known history of genital herpes but may have a history of other sexually transmitted diseases and demonstrated that maternal immunity to HSV infection affords some type-specific immunity to the infant.3,4 They have shown the importance of cesarean delivery in reducing but not eliminating the risk of mother-to-infant transmission.5,6 These investigators developed the classification system that distinguishes between disease apparently limited to the portals of entry (the skin, eyes, and mouth) and more severe forms of encephalitis and disseminated infection.7 They have documented the … Address correspondence to Lawrence R. Stanberry, MD, PhD, Department of Pediatrics and the Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, 301 University Blvd, Galveston, TX 77555-0351. E-mail: l.stanberry{at}utmb.edu
Electronic Relaxation in Benzaldehyde Evaluated via TD-DFT and Localized Diabatization: Intersystem Crossings, Conical Intersections, and Phosphorescence

The photophysics of benzaldehyde are analyzed through the lens of TD-DFT adiabatic excited states and Boys or Edmiston–Ruedenberg localized diabatic states. We predict rate constants for two processes in excited benzaldehyde: (i) the intersystem crossing from S1 → T2 and (ii) the phosphorescence from T1 → S0. We also study (iii) the conical intersection between T2 and T1 that is putatively responsible for an ultrafast internal conversion process, T2 → T1. In agreement with Ohmori et al. (J. Phys. Chem. 1988, 92 (5), 1086–1093), our results suggest that the S1 → T2 intersystem crossing in benzaldehyde is rapid not only because of a large spin–orbit matrix element (i.e., El-Sayed’s rule) but also because of a fortuitously small energy barrier. Furthermore, when studying the T2 → T1 internal conversion, we find that both Boys and Edmiston–Ruedenberg localization give remarkably stable and accurate diabatic states which will be useful for ongoing studies of dynamics near conical intersections. To our knowledg...
A NEW TRIANGULAR AND TETRAHEDRAL BASIS FOR HIGH-ORDER (HP) FINITE ELEMENT METHODS

In this paper we describe the foundations of a new hierarchical modal basis suitable for high-order (hp) finite element discretizations on unstructured meshes. It is based on a generalized tensor product of mixed-weight Jacobi polynomials. The generalized tensor product property leads to a low operation count with the use of sum factorization techniques. Variable p-order expansions in each element are readily implemented which is a crucial property for efficient adaptive discretizations. Numerical examples demonstrate the exponential convergence for smooth solutions and the ability of this formulation to handle easily very complex two- and three-dmensional computational domains employing standard meshes.
Primary Care Providers’ Responses to Patient-Generated Family History

Family health history is one of the best predictors of an individual’s risk for common disease, yet it is underutilized in routine care. Although the Surgeon General has recommended consumers record their family health history and share it with their health care provider, providers’ perceptions of patient-generated family histories are unknown. To learn more about providers’ experience with and perceptions about patient-generated family histories, we mailed surveys to 301 providers and had a response rate of 24% (n = 68). Seventy-three percent felt a patient-generated computer pedigree would improve their ability to assess risk as compared to their current methods. Seventy percent felt a patient-generated computer pedigree would either have no effect on or would increase the number of patients that could be seen in a day. Results suggest that providers appreciate the potential benefits of patient-generated family histories. Genetic counselors and nurses are in a prime position to promote and facilitate the use of patient-generated family health histories in routine care.