364 research outputs found
TB63: Variation in Foliar Nutrient Concentrations in Red Spruce
Red spruce (Picea rubens Sarg.) is an important pulpwood species in northern New England and Canada. Management objectives favor this species and the closely related black spruce (Picea mariana Mill. BSP) on many sites. Foliar nutrient concentrations of unfertilized, economically mature, red spruce trees growing on four different sites and over two- and three-year periods are presented here and compared to foliar concentrations reported by other scientists.https://digitalcommons.library.umaine.edu/aes_techbulletin/1136/thumbnail.jp
The Crystal Structure of (2,3,9,10-tetramethyl-1,4,8,11-tetraaza- 1,3,8, 10-cyclotetradecatetraene )copper(II) Tetraphenylborate
The crystal structure (P21/c, a = 1199.7(2), b = 1304.2(4), c =
= 1639.1(4) pm, beta = 102.10(1) 0 (J.. MoKa = 71.069 pm), Z = 2) of
this compound, [CuC14H24N4] [B(C5Hs)4]2, has been determined from
diffractometer x-ray data and refined by least-squares to R = 0.055
and Rw = 0.037.
The CuTIM cation, planar except for two methylene groups,
is one of the rare cases of planar four-coordinate copper(II),
although the apical regions of the coordination sphere are occupied
by the centers of phenyf groups from two tetraphenylborate ions.
The tetraphenylborate ion has a normal conformation which
deviates slightly, but significantly, from S4 symmetry
Survey of Individual Members and Member Organizations on the Costs and Benefits of Belonging to a Community-Based Public Health (CBPH) Consortium).
Prepared for the Community-Based Public Health Initiative by the Center for Urban and Regional Affairs, University of Minnesota. Funded by the W.K. Kellogg Foundation
What I see is what I want: top-down attention biasing choice behavior
Health and self-regulatio
A HPMT based set-up to characterize scintillating crystals
We have developed a fully automatic measurement set-up, capable of measuring light yields arising from scintillating crystals in a linear range of about four orders of magnitude. The photodetector is a Hybrid Photomultiplier Tube especially developed to optimize linear range and photon detection. Crystal and photodetector are temperature controlled by a closed water circuit, as this is essential when measuring low light yield scintillating crystals with a marked temperature dependence of their light yield. Gamma sources can be placed either on top or on the side of the crystal. In this latter case, the source can be automatically moved by a computer-controlled step motor to provide a uniformity profile of the light yield along the crystal. Tagged and not-tagged operation modes are possible. The whole set-up is computer-controlled in an effort to provide fast and reliable measurements, to characterize many crystals per day. This is important for the quality control of the Lead Tungstate crystals that will be applied in the electromagnetic calorimeter of the CMS-detector at the LHC at CERN
The Crystal Structure of (2,3,9,10-tetramethyl-1,4,8,11-tetraaza- 1,3,8, 10-cyclotetradecatetraene )copper(II) Tetraphenylborate
The crystal structure (P21/c, a = 1199.7(2), b = 1304.2(4), c =
= 1639.1(4) pm, beta = 102.10(1) 0 (J.. MoKa = 71.069 pm), Z = 2) of
this compound, [CuC14H24N4] [B(C5Hs)4]2, has been determined from
diffractometer x-ray data and refined by least-squares to R = 0.055
and Rw = 0.037.
The CuTIM cation, planar except for two methylene groups,
is one of the rare cases of planar four-coordinate copper(II),
although the apical regions of the coordination sphere are occupied
by the centers of phenyf groups from two tetraphenylborate ions.
The tetraphenylborate ion has a normal conformation which
deviates slightly, but significantly, from S4 symmetry
Contrasting the beam interaction characteristics of selected lasers with a partially stabilised zirconia (PSZ) bio-ceramic
Differences in the beam interaction characteristics of a CO2 laser, a Nd:YAG laser, a high power diode laser (HPDL) and an excimer laser with a partially stabilised zirconia (PSZ) bio-ceramic have been studied. A derivative of Beer-Lambert’s law was applied and the laser beam absorption lengths of the four lasers were calculated as 33.55 x 10-3 cm for the CO2 laser, 18.22 x 10-3 cm for the Nd:YAG laser, 17.17 x 10-3 cm for the HPDL and 8.41 x 10-6 cm for the excimer laser. It was determined graphically that the fluence threshold values at which significant material removal was effected by the CO2 laser, the Nd:YAG laser, the HPDL and the excimer laser were 52 J/cm2, 97 J/cm2, 115 J/cm2 and 0.48 J/cm2 respectively. The thermal loading value for the CO2 laser, the Nd:YAG laser, the HPDL and the excimer laser were calculated as being 1.55 kJ/cm3, 5.32 kJ/cm3, 6.69 kJ/cm3 and 57.04 kJ/cm3 respectively
Wettability characteristics of an Al2O3/SiO2-based ceramic modified with CO2, Nd:YAG, excimer and high-power diode lasers
Interaction of CO2, Nd:YAG, excimer and high power diode laser (HPDL) radiation with the
surface of an Al2O3/SiO2 based ceramic was found to effect significant changes in the
wettability characteristics of the material. It was observed that interaction with CO2, Nd:YAG
and HPDL radiation reduced the enamel contact angle from 1180 to 310, 340 and 330
respectively. In contrast, interaction with excimer laser radiation resulted an increase in the
contact angle to 1210. Such changes were identified as being due to: (i) the melting and partial
vitrification of the Al2O3/SiO2 based ceramic surface as a result of interaction with CO2,
Nd:YAG HPDL radiation. (ii) the surface roughness of the Al2O3/SiO2 based ceramic
increasing after interaction with excimer laser radiation. (iii) the surface oxygen content of the
Al2O3/SiO2 based ceramic increasing after interaction with CO2, Nd:YAG and HPDL radiation.
The work has shown that the wettability characteristics of the Al2O3/SiO2 based ceramic could
be controlled and/or modified with laser surface treatment. In particular, whether the laser
radiation had the propensity to cause surface melting. However, a wavelength dependance of
the change of the wetting properties could not be deduced from the findings of this work
Mortality in patients with HIV-1 infection starting antiretroviral therapy in South Africa, Europe, or North America: a collaborative analysis of prospective studies
Analyzing survival in HIV treatment cohorts, Andrew Boulle and colleagues find mortality rates in South Africa comparable to or better than those in North America by 4 years after starting antiretroviral therapy. Please see later in the article for the Editors' Summar
Baseline Predictors of Sputum Culture Conversion in Pulmonary Tuberculosis: Importance of Cavities, Smoking, Time to Detection and W-Beijing Genotype
Background: Time to detection (TTD) on automated liquid mycobacterial cultures is an emerging biomarker of tuberculosis
outcomes. The M. tuberculosis W-Beijing genotype is spreading globally, indicating a selective advantage. There is a paucity
of data on the association between baseline TTD and W-Beijing genotype and tuberculosis outcomes.
Aim: To assess baseline predictors of failure of sputum culture conversion, within the first 2 months of antitubercular
therapy, in participants with pulmonary tuberculosis.
Design: Between May 2005 and August 2008 we conducted a prospective cohort study of time to sputum culture
conversion in ambulatory participants with first episodes of smear and culture positive pulmonary tuberculosis attending
two primary care clinics in Cape Town, South Africa. Rifampicin resistance (diagnosed on phenotypic susceptibility testing)
was an exclusion criterion. Sputum was collected weekly for 8 weeks for mycobacterial culture on liquid media (BACTEC
MGIT 960). Due to missing data, multiple imputation was performed. Time to sputum culture conversion was analysed using
a Cox-proportional hazards model. Bayesian model averaging determined the posterior effect probability for each variable.
Results: 113 participants were enrolled (30.1% female, 10.5% HIV-infected, 44.2% W-Beijing genotype, and 89% cavities). On
Kaplan Meier analysis 50.4% of participants underwent sputum culture conversion by 8 weeks. The following baseline
factors were associated with slower sputum culture conversion: TTD (adjusted hazard ratio (aHR) = 1.11, 95% CI 1.02; 1.2),
lung cavities (aHR = 0.13, 95% CI 0.02; 0.95), ever smoking (aHR = 0.32, 95% CI 0.1; 1.02) and the W-Beijing genotype
(aHR = 0.51, 95% CI 0.25; 1.07). On Bayesian model averaging, posterior probability effects were strong for TTD, lung
cavitation and smoking and moderate for W-Beijing genotype.
Conclusion: We found that baseline TTD, smoking, cavities and W-Beijing genotype were associated with delayed 2 month
sputum culture. Larger studies are needed to confirm the relationship between the W-Beijing genotype and sputum culture
conversion.Publisher's versio
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