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Some aerodynamic features of a cotton canopy
Analysis of profiles measured over irrigated cotton in the Sudan Gezira showed that the crop boundary
layer remained stable throughout most of the day. The shape of wind profiles measured within the canopy
suggested that momentum was absorbed mostly in the upper layers of the canopy, with the lower regions
remaining isolated from the microclimate above. A similarity analysis based on dynamic scaling factors
yielded a generalized wind profile from which momentum diffusivities and mixing lengths were calculated.
The analysis showed that aerodynamic features of the upper layers of the canopy were characterized by the
friction velocity and the height of the zero-plane displacement
Efficient supercontinuum generation in quadratic nonlinear waveguides without quasi-phase matching
Efficient supercontinuum generation (SCG) requires excitation of solitons at
the pump laser wavelength. Quadratic nonlinear waveguides may support an
effective self-defocusing nonlinearity so solitons can directly be generated at
common ultrafast laser wavelengths without any waveguide dispersion
engineering. We here experimentally demonstrate efficient SCG in a standard
lithium niobate (LN) waveguide without using quasi-phase matching (QPM). By
using femtosecond pumps with wavelengths in the range,
where LN has normal dispersion and thus supports self-defocusing solitons,
octave-spanning SCG is observed. An optimized mid-IR waveguide design is
expected to support even broader spectra. The QPM-free design reduces
production complexity, allows longer waveguides, limits undesired spectral
resonances and effectively allows using nonlinear crystals where QPM is
inefficient or impossible. This result is important for mid-IR SCG, where
QPM-free self-defocusing waveguides in common mid-IR nonlinear crystals can
support solitons directly at mid-IR ultrafast laser wavelengths, where these
waveguides have normal dispersion.Comment: To appear in Optics Letter
Investigations on antibody binding to a micro-cantilever coated with a BAM pesticide residue
The attachment of an antibody to an antigen-coated cantilever has been investigated by repeated experiments, using a cantilever-based detection system by Cantion A/S. The stress induced by the binding of a pesticide residue BAM (2,6 dichlorobenzamide) immobilized on a cantilever surface to anti-BAM antibody is measured using the CantiLab4© system from Cantion A/S with four gold-coated cantilevers and piezo resistive readout. The detection mechanism is in principle label-free, but fluorescent-marked antibodies have been used to subsequently verify the binding on the cantilever surface. The bending and increase in mass of each cantilever has also been investigated using a light interferometer and a Doppler Vibrometer. The system has been analyzed during repeated measurements to investigate whether the CantiLab4© system is a suited platform for a pesticide assay system
Surface-enhanced Raman spectroscopic study of DNA and 6-mercapto-1-hexanol interactions using large area mapping
Statistical analysis of large areas of Raman mapped DNA functionalized gold coated silicon nanopillar SERS substrates
Bioenergetic Abnormalities Associated with Severe Left Ventricular Hypertrophy
Abstract Transmurally localized 31P-nuclear magnetic resonance spectroscopy (NMR) was used to study the effect of severe pressure overload left ventricular hypertrophy (LVH) on myocardial high energy phosphate content. Studies were performed on 8 normal dogs and 12 dogs with severe left ventricular hypertrophy produced by banding the ascending aorta at 8 wk of age. Spatially localized 31P-NMR spectroscopy provided measurements of the transmural distribution of myocardial ATP, phosphocreatine (CP), and inorganic phosphate (Pi); spectra were calibrated from measurements of ATP content in myocardial biopsies using HPLC. Blood flow was measured with microspheres. In hypertrophied hearts during basal conditions, ATP was decreased by 42%, CP by 58%, and the CP/ATP ratio by 32% in comparison with normal. Increasing myocardial blood flow with adenosine did not correct these abnormalities, indicating that they were not the result of persistent hypoperfusion. Atrial pacing at 200 and 240 beats per min caused no change in high energy phosphate content in normal hearts but resulted in further CP depletion with Pi accumulation in the inner left ventricular layers of the hypertrophied hearts. These changes were correlated with redistribution of blood flow away from the subendocardium in LVH hearts. These findings demonstrate that high energy phosphate levels and the CP/ATP ratio are significantly decreased in severe LVH. These abnormalities are proportional to the degree of hypertrophy but are not the result of persistent abnormalities of myocardial perfusion. In contrast, depletion of CP and accumulation of Pi during tachycardia in LVH are closely related to the pacing-induced perfusion abnormalities and likely reflect subendocardial ischemia. (J. Clin. Invest. 1993. 92:993-100
Longitudinal estimation of Plasmodium falciparum prevalence in relation to malaria prevention measures in six sub-Saharan African countries.
BACKGROUND: Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmission intensity. This study was carried out concurrently with the RTS,S/AS01 candidate malaria vaccine Phase III trial and estimated PfPR over â€Â 4 standardized cross-sectional surveys. METHODS: This epidemiology study (NCT01190202) was conducted in 8 sites from 6 countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, and Tanzania), between March 2011 and December 2013. Participants were enrolled in a 2:1:1 ratio according to age category: 6 months-4 years, 5-19 years, and â„ 20 years, respectively, per year and per centre. All sites carried out surveys 1-3 while survey 4 was conducted only in 3 sites. Surveys were usually performed during the peak malaria parasite transmission season, in one home visit, when medical history and malaria risk factors/prevention measures were collected, and a blood sample taken for rapid diagnostic test, microscopy, and haemoglobin measurement. PfPR was estimated by site and age category. RESULTS: Overall, 6401 (survey 1), 6411 (survey 2), 6400 (survey 3), and 2399 (survey 4) individuals were included in the analyses. In the 6 months-4 years age group, the lowest prevalence (assessed using microscopy) was observed in 2 Tanzanian centres (4.6% for Korogwe and 9.95% for Bagamoyo) and LambarĂ©nĂ©, Gabon (6.0%), while the highest PfPR was recorded for Nanoro, Burkina Faso (52.5%). PfPR significantly decreased over the 3 years in Agogo (Ghana), Kombewa (Kenya), Lilongwe (Malawi), and Bagamoyo (Tanzania), and a trend for increased PfPR was observed over the 4 surveys for Kintampo, Ghana. Over the 4 surveys, for all sites, PfPR was predominantly higher in the 5-19 years group than in the other age categories. Occurrence of fever and anaemia was associated with high P. falciparum parasitaemia. Univariate analyses showed a significant association of anti-malarial treatment in 4 surveys (odds ratios [ORs]: 0.52, 0.52, 0.68, 0.41) and bed net use in 2 surveys (ORs: 0.63, 0.68, 1.03, 1.78) with lower risk of malaria infection. CONCLUSION: Local PfPR differed substantially between sites and age groups. In children 6 months-4 years old, a significant decrease in prevalence over the 3 years was observed in 4 out of the 8 study sites. Trial registration Clinical Trials.gov identifier: NCT01190202:NCT. GSK Study ID numbers: 114001
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