Home About us Contact
|
Home About us Contact | ||
|
|
||
Several Sets (several + set)
Selected AbstractsTuned mass dampers for response control of torsional buildingsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4 2002Mahendra P. Singh Abstract This paper presents an approach for optimum design of tuned mass dampers for response control of torsional building systems subjected to bi-directional seismic inputs. Four dampers with fourteen distinct design parameters, installed in pairs along two orthogonal directions, are optimally designed. A genetic algorithm is used to search for the optimum parameter values for the four dampers. This approach is quite versatile as it can be used with different design criteria and definitions of seismic inputs. It usually provides a globally optimum solution. Several optimal design criteria, expressed in terms of performance functions that depend on the structural response, are used. Several sets of numerical results for a torsional system excited by random and response spectrum models of seismic inputs are presented to show the effectiveness of the optimum designs in reducing the system response. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effect of water treatment on analyte and matrix ion yields in matrix-assisted time-of-flight secondary ion mass spectrometry: the case of insulin in and on hydroxycinnamic acidRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 21 2002Wilfried Szymczak A systematic study was performed to identify the origin of surprisingly high analyte-to-matrix yield ratios recently observed in time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis of oligo- and polypeptides mixed in matrices of ,-cyano-4-hydroxycinnamic acid (4HCCA). Several sets of samples of porcine insulin in 4HCCA (1:3100 molar) were prepared from liquid solutions by a nebuliser technique, with more than one order of magnitude variation in sprayed material (substrate silicon). Following different periods of storage in air and/or vacuum as well as exposure to high-purity water, TOF-SIMS analysis was performed under oblique impact of 22 keV SF5+. Treatment with water involved either deposition of a droplet covering the whole sample for times between 1 and 20,min or spraying with water in droplet equivalent quantities. The analyte and matrix molecules were detected as protonated molecules (insulin also in doubly protonated form). Even the as-prepared samples usually showed insulin-to-4HCCA yield ratios exceeding the molar ratio of the mixed material. Upon ageing in vacuum the matrix ion yields remained constant but the analyte yields decreased, partly due to break-up of intrachain disulfide bonds. Water treatment resulted in a pronounced decrease in the 4HCCA yield, typically by a factor of five, in parallel with an increase of the insulin yield, by up to a factor of four. Evidence is provided that these changes occur concurrently with a partial dissolution of 4HCCA at the sample surface. The enhanced insulin yield was not correlated with the Na+ yield. The typically 20-fold increase in the insulin-to-4HCCA yield ratio, generated by water exposure of the samples, provides the explanation for the high yield ratios observed previously with water-treated samples. Spraying with water or repeated exposure to water droplets caused a pronounced degradation of the insulin parent yields in combination with an increasing appearance of signals due to the B- and A-chains of insulin. To clarify the issue of surface segregation, a few samples were prepared by spraying acetone-diluted solutions of insulin on previously deposited layers of 4HCCA. Whereas the insulin yields from as-prepared samples were rather low, the yields observed after water treatment were comparable with those observed with samples of insulin in 4HCCA. The results suggest that a large amount of insulin is present at the surface of samples prepared from liquid mixtures of insulin in 4HCCA. With both methods of sample preparation, however, high secondary ion yields of insulin were only obtained after exposure of the samples to water. The chemical changes responsible for this beneficial effect still need to be identified. Copyright © 2002 John Wiley & Sons, Ltd. [source] Risk factors and outcome of community-acquired pneumonia due to Gram-negative bacilliRESPIROLOGY, Issue 1 2009Miquel FALGUERA Background and objective: Several sets of guidelines have advocated initial antibiotic treatment for community-acquired pneumonia due to Gram-negative bacilli in patients with specific risk factors. However, evidence to support this recommendation is scarce. We sought to identify risk factors for community-acquired pneumonia due to Gram-negative bacilli, including Pseudomonas aeruginosa, and to assess outcomes. Methods: An observational analysis was carried out on prospectively collected data for immunocompetent adults hospitalized for community-acquired pneumonia in two acute-care hospitals. Cases of pneumonia due to Gram-negative bacilli were compared with those of non-Gram-negative bacilli causes. Results: Sixty-one (2%) of 3272 episodes of community-acquired pneumonia were due to Gram-negative bacilli. COPD (odds ratio (OR) 2.4, 95% confidence interval (CI): 1.2,5.1), current use of corticosteroids (OR 2.8, 95% CI: 1.2,6.3), prior antibiotic therapy (OR 2.6, 95% CI: 1.4,4.8), tachypnoea ,30 cycles/min (OR 2.1, 95% CI: 1.1,4.2) and septic shock at presentation (OR 6.1, 95% CI: 2.5,14.6) were independently associated with Gram-negative bacilli pneumonia. Initial antibiotic therapy in patients with pneumonia due to Gram-negative bacilli was often inappropriate. These patients were also more likely to require admission to the intensive care unit, had longer hospital stays, and higher early (<48 h) (21% vs 2%; P < 0.001) and overall mortality (36% vs 7%; P < 0.001). Conclusions: These results suggest that community-acquired pneumonia due to Gram-negative bacilli is uncommon, but is associated with a poor outcome. The risk factors identified in this study should be considered when selecting initial antibiotic therapy for patients with community-acquired pneumonia. [source] Systemic plant signal triggers genome instabilityTHE PLANT JOURNAL, Issue 1 2004Jody Filkowski Summary Previously, we have shown that infection of tobacco plants with a viral pathogen triggers local and systemic induction of homologous recombination (HR). Here, we have tested the hypothesis of whether free radicals are potentially involved in the induction of the systemic effect. We report a significant induction of HR in tobacco plants treated with radical-generating agents, UVC or rose Bengal (RB). Importantly, the recombination increase was observed in local (treated) as well as systemic (non-treated) tissue. The systemic increase in recombination implies the existence of a signal that is transmitted to non-treated tissue. Several sets of grafting experiments proved the generation of said signal by both RB and UVC exposure. A statistically significant increase in HR was observed in tissue that received a systemic signal via a grafted leaf. Similar data were obtained from transgenic plants naphthalene degrading salicylate 1-hydroxylase (NahG) unable to accumulate salicylic acid (SA). Interestingly, pre-treatment of plants with the radical-scavenging compound N -acetyl- l -cysteine (NAC) led to a significantly lower recombination increase upon grafting after treatment with UVC and RB. Moreover, leaves taken for grafting from NAC-pre-treated plants exhibited a lower level of oxidized organic compounds. Our data suggest the involvement of free radical production in either generation or maintenance of the recombination signal. We discuss potential mechanisms for generation of the signal and possible adaptive advantages of enhanced genomic flexibility following exposure to DNA-damaging agents. [source] Antibiotic Prophylaxis Guideline Awareness and Antibiotic Prophylaxis Use Among New York State Dermatologic SurgeonsDERMATOLOGIC SURGERY, Issue 9 2002Noah Scheinfeld JD background. Use of antibiotic prophylaxis in dermatologic surgery patients remains controversial and several sets of guidelines exist. objective. We investigated dermatologic surgeon's awareness of the American Heart Association (AHA) 1997 antibiotic prophylaxis guidelines, their use of prophylactic antibiotics, and their practices as compared with the Haas and Grekin's 1995 antibiotic prophylaxis guidelines. methods. We mailed postage-paid questionnaires regarding AHA guideline awareness and antibiotic prophylaxis use to the 235 New York State members of the American Society for Dermatologic Surgery (ASDS). We received 87 replies. results. Most participants recognize AHA guidelines and claim to follow them. We reiterate previous studies' findings. Most dermatologic surgeons use antibiotics appropriately. However, antibiotics are occasionally overused or dosed outside the guidelines. Many participants prescribe antibiotics based on a patient's other physicians' recommendations. Notably, erythromycin is sometimes used, an antibiotic the AHA no longer recommends. conclusion. Dermatologic surgeons commonly use antibiotic prophylaxis to prevent bacterial endocarditis. Based on previous studies, though, the risk of endocarditis following cutaneous surgery is low and thus the use of antibiotic prophylaxis is controversial. Although this practice is appropriate for high-risk patients when skin is contaminated, it is not recommended for noneroded, noninfected skin. We report that dermatologists may be aware of the guidelines, but only seem to partially follow them. Further studies are still needed to establish optimal guidelines. [source] (4-Acyl-5-pyrazolonato)titanium Derivatives: Oligomerization, Hydrolysis, Voltammetry, and DFT StudyEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2003Francesco Caruso Abstract Twenty 4-acyl-5-pyrazolonato (Q) titanium derivatives of varied nuclearity have been synthesized from Ti(OR)4 or TiCl4 and characterized with spectroscopic methods (IR, NMR, ESI-MS). While Ti,(,-diketonato) cleavage is not seen in isolated solids, Ti,O(alkoxy) (or Ti,Cl) bonds cleave upon hydrolysis, leading to several structural forms, including oligomers. Ionic Q species with no Ti, i.e., obtained after Ti,Q cleavage, are seen for some Ti,Q derivatives by ESI-MS, which also indicates a varied nuclearity for a given species, e.g., the isolated polynuclear [Q2Ti-,-O]n has several "n" values. Mononuclear Ti complexes are obtained under rigorous anhydrous conditions. The cis structures of the mononuclear species (QT)2Ti(OCH3)2, QT = 3-methyl-4-(neopentylcarbonyl)-1-phenylpyrazol-5-onato have been analyzed with DFT methods. A trans influence is a major driving force that accounts for several sets of Ti,O bonds. One of the cis stereoisomers is 56 kcal/mol higher in energy than the other two. In contrast, all (QT)2TiCl2cis isomers show similar energies. Voltammetry of the mononuclear species (QT)2Ti(OnPr)2 and the antitumor tetranuclear compound [(QB)2Ti-,-O]4, (QB = 4-benzoyl-3-methyl-1-phenylpyrazol-5-onato) indicate that the TiIV is less prone to reduction to TiIII in the latter (Epc for the TiIV/TiIII couple is ,1.71 V and ,1.46 V versus Fc+/Fc, respectively). Potential antitumor compounds having a Ti/Q ratio of 1:1 do not disproportionate, unlike the equivalent acetylacetonato derivatives, and are water-soluble. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Performance Evaluation of the KEOPS Wavelength Routing Optical Packet SwitchEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2000Philippe Cadro This paper presents results concerning the performance evaluation of the KEOPS wavelength routing optical transparent packetswitch. This switch solves contention using optical delay lines; these delay lines are grouped in several sets, in the first stage of the switch. Each input port has access to a few of these delay lines, and each set of delay lines has access to each output port. Non-FIFO output buffers are thus emulated using scheduling on a small number of delay lines with non-consecutive delays. Under simplifying assumptions, analytical models are derived, and checked by simulation. These models provide efficient bounds for estimating packet loss probability, under the assumption of regular, balanced input traffic. It is shown that the proposed switch architecture achieves a good performance in terms of packet loss, with a number of delay lines significantly smaller than the ones currently used in other architectures. [source] Vertically fractured transversely isotropic media: dimensionality and deconstructionGEOPHYSICAL PROSPECTING, Issue 2 2009Michael A. Schoenberg ABSTRACT A vertically fractured transversely isotropic (VFTI) elastic medium is one in which any number of sets of vertical aligned fractures (each set has its normal lying in the horizontal x1, x2 -plane) pervade the medium and the sets of aligned fractures are the only features of the medium disturbing the axi-symmetry about the x3 -axis implying that in the absence of fractures, the background medium is transversely isotropic (TI). Under the assumptions of long wavelength equivalent medium theory, the compliance matrix of a fractured medium is the sum of the background medium's compliance matrix and a fracture compliance matrix. For sets of parallel rotationally symmetric fractures (on average), the fracture compliance matrix is dependent on 3 parameters , its normal and tangential compliance and its strike direction. When one fracture set is present, the medium is orthorhombic and the analysis is straightforward. When two (non-orthogonal) or more sets are present, the overall medium is in general elastically monoclinic; its compliance tensor components are subject to two equalities yielding an 11 parameter monoclinic medium. Constructing a monoclinic VFTI medium with n embedded vertical fracture sets, requires 5 TI parameters plus 3×n fracture set parameters. A deconstruction of such an 11 parameter monoclinic medium involves using its compliance tensor to find a background transversely isotropic medium and several sets of vertical fractures which, in the long wavelength limit, will behave exactly as the original 11 parameter monoclinic medium. A minimal deconstruction, would be to determine, from the 11 independent components, the transversely isotropic background (5 parameters) and two fracture sets (specified by 2 × 3 = 6 parameters). Two of the background TI medium's compliance matrix components are known immediately by inspection, leaving nine monoclinic components to be used in the minimal deconstruction of the VFTI medium. The use of the properties of a TI medium, which are linear relations on its compliance components, allows the deconstruction to be reduced to solving a pair of non-linear equations on the orientations of two fracture sets. A single root yielding a physically meaningful minimum deconstruction yields a unique minimal representation of the monoclinic medium as a VFTI medium. When no such root exists, deconstruction requires an additional fracture set and uniqueness is lost. The boundary between those monoclinic media that have a unique minimal representation and those that do not is yet to be determined. [source] Musculature of Notholca acuminata (Rotifera: Ploima: Brachionidae) revealed by confocal scanning laser microscopyINVERTEBRATE BIOLOGY, Issue 3 2003Martin V. Sørensen Abstract. The body-wall and visceral musculature of Notholca acuminata was visualized using phalloidin-linked fluorescent dye under confocal laser scanning microscopy. The body-wall musculature includes dorsal, lateral, and ventral pairs of longitudinally oriented body retractor muscles, two pairs of head retractors, three pairs of incomplete circular muscles, which are modified into dorso-ventral muscles, and a single pair of dorsolateral muscles. The visceral musculature consists of a complex of thick muscles associated with the mastax, as well as several sets of delicate fibers associated with the corona, stomach, gut, and cloaca, including thin longitudinal gut fibers and viscero-cloacal fibers, never before reported in other species of rotifers. The dorsal, lateral, and ventral retractor muscles and the incomplete circular muscles associated with the body wall appear to be apomorphies for the Rotifera. Muscle-revealing staining shows promise for providing additional information on previously unrecognized complexity in rotifer musculature that will be useful in functional morphology and phylogenetic analyses. [source] Evaluation of double-crystal SANS data influenced by multiple scatteringJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3-1 2000aroun Evaluation of small-angle neutron scattering (SANS) data is often complicated by multiple scattering effects if large particles of relatively high volume fraction have to be studied and dilution or contrast reduction is impossible. The use of pin-hole SANS instruments is often limited due to the contradictory requirements of high resolution and short wavelength needed to keep scattering contrast as low as possible. Double crystal (DC) SANS diffractometers of Bonse-Hart and bent-crystal type are useful alternatives in such cases, as they permit reaching very high resolution with thermal neutrons. A method for SANS data evaluation suited to DC instruments is presented. It includes the common scheme of the indirect Fourier transformation method, but takes multiple scattering into account. The scattering medium is described by the frequency function g(x) defined as the cosine Fourier transform of slit-smeared data. Although a simplistic model of polydisperse spheres is used to represent g(x), resulting g(x) function and some integral parameters are independent of this model. Tests on simulated data show, that the method reproduce well true values of microstructural parameters, though systematic errors are observed in the cases when the unscattered part of incident beam completely disappears. If the scattering power Gaussian-type function set without prolapse for the Dirac,Fock,Roothaan equationJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 15 2003Hiroshi Tatewaki Abstract A Gaussian-type function (GTF) set without a prolapse (variation collapse) is generated for the Dirac,Fock,Roothaan (DFR) equation. The test atom was mercury. The number of primitive GTFs used is between 7and 62 (abbreviated as 7,62), 6,62, 6,62, 4,36, 4,36, 3,36, and 3,36 for s+, p,, p+, d,, d+, f,, and f+ symmetries. The respective exponent parameters were determined with even-tempered manner, which requires the minimum and maximum exponents for the respective symmetries. We prepared several sets of these. The total energy (TE) given by the numerical DF (NDF) is ,19648.849250 hartree; one of the present sets with largest number of expansion terms gave ,19648.849251 hartree. The error (,TE) relative to the NDR TE is quite small. We then applied this set to the inert gas atoms Ne (10), Ar (18), Kr (36), Xe (54), Rn (86), and No (102), and also to Es (99) as the representative of the open shell atoms. The absolute values of ,TE were at most 2.8 × 10,6 hartree, showing the potential of this set as a universal set. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 1823,1828, 2003 [source] Superposition of the output pulses under synchronous discharge in a multiple-electrode-pair laserMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2002Lihua Ye Abstract If the pressure, voltage, and other discharge parameters of a multiple-electrode-pair laser are held constant, there is a nonlinear pulse energy enhancement effect when several sets of electrode pairs are triggered synchronously. The mechanism of the effect is analyzed and a reasonable theoretical model, which is in agreement with the experimental results, is built. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 207,211, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10418 [source] 3142: Radiation-induced lens opacities: towards a new strategy to address the low dose risk research with the European network DoReMiACTA OPHTHALMOLOGICA, Issue 2010P GOURMELON In 2010, a Network of Excellence called DoReMi was launched by the EURATOM FP7 programme. DoReMi will act during the next six years as an operational tool for the development of a research platform devoted to low dose risk research in Europe. The research activities of DoReMi are implemented within three work packages: WP5, WP6, and WP7, which are respectively concerned with the shape of the dose effect relationship, individual radiation sensitivity and non-cancer effects. The overarching objective of WP7 is to implement a long-term, integrated approach involving several disciplines, namely, epidemiology, radiobiology and toxicology, for the purpose of risk evaluation for radiation-induced non-cancer effects. One of the operational objectives of the DoReMi WP7 consists of undertaking feasibility studies addressing the issues of vascular effects, lens opacities and cognitive effects. The presentation to be given will provide the assembly with (i) information about the European low dose risk research strategy; (ii) latest knowledge about the epidemiological evidence of radiation-induced lens opacities; (iii) information about the feasibility study of lens opacities to be launched in a group of interventional cardiologists (iv) most promising mechanistic hypotheses for the development of radiation-induced lens opacities recognizing that while posterior subcapsular cataracts are characteristic of an exposure to ionizing radiation, several sets of data suggest that the broader category of posterior cortical cataracts may also be regarded as radiation-associated. Eventually the presentation will discuss the issue of a threshold for the development of radiation-induced lens opacities and list the scientific questions raised by the radiation protection community to the vision and eye research community. [source] Color constancy from invariant wavelength ratios: I. The empirical spectral mechanismCOLOR RESEARCH & APPLICATION, Issue 3 2008Ralph W. PridmoreArticle first published online: 10 APR 200 Abstract The wavelengths of several constant hues over four illuminants (D95, D65, D50, A) are derived from several sets of published data. In the plane of wavelength and reciprocal illuminant color temperature (MK,1), the wavelengths of constant hues plot straight approximately parallel lines whose mean slope is about 87°. Parallel lines give invariant wavelength ratios, hence constant hues in this plane are near-invariant wavelength ratios across illuminants. As recently demonstrated, the complementary wavelengths to a constant hue (across illuminants) represent the complementary constant hue; these complementary wavelengths also plot a near-parallel line to the first constant hue. To confirm and further define the constant slope of these lines, it is shown that complementary wavelength pairs, per CIE data, can only plot parallel straight lines at the angle of 87° ± 1. In summary, near-parallel sloping lines represent constant hues at near-invariant wavelength ratios. This mechanism of color constancy is shown to relate to the well-known theory of relational color constancy from invariant cone-excitation ratios. In the visual process, the latter ratios are presumably the source of the former (invariant wavelength ratios). © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 238,249, 2008 [source]
| | ||||||||||||||||||