Promiscuous Expression of alpha-Tubulin II in Maturing Male and Female Plasmodium falciparum Gametocytes

Background: Antimalarial interventions designed to impact on the transmissible sexual stages of Plasmodium falciparum are evaluated by measurement of peripheral gametocyte carriage in vivo and infectivity to mosquitoes. Drug or vaccine-elicited effects may differentially affect the relative abundance of mature male and female sexual forms, and this can be measured by estimation of sex ratios before and after intervention in vivo and in vitro. Measuring the impact of anti-gametocyte drugs on sexual commitment of immature gametocyte stages in vitro is not currently possible as male and female parasites cannot be distinguished by morphology alone prior to stage IV.Methodology/Principal Findings: We have modified an existing immunofluorescence-based approach for distinguishing male and female gametocytes during development in vitro, by using highly synchronised magnetically-enriched gametocyte preparations at different stages of maturity. Antibodies recognising alpha-tubulin II ( males) and Pfg377 ( females) were used to attempt to discriminate the sexes. Transcription of these two proteins was not coordinated during in vitro development, with pfg377 transcripts accumulating only late in development, immediately prior to immunofluorescent signals from the PfG377 protein appearing in stage IV gametocytes. Contrary to previous descriptions of this protein as male-specific in P. falciparum, alpha-tubulin II recognised both male and female gametocytes at stages I to IV, but evidence of differential expression levels of this protein in late stage male and female gametocytes was found. Using antibodies recognising PfG377 as the primary marker and alpha-tubulin II as a secondary marker, robust estimates of sex ratio in in vitro cultures were obtained for gametocytes at stage IV or later, and validated by light microscopic counts. However, sex ratio estimation was not possible for early stage gametocytes due to the promiscuity of alpha-tubulin II protein expression, and the relatively late accumulation of PfG377 during the development process.Conclusions/Significance: This approach is a feasible method for the evaluation of drug impacts on late-stage gametocyte sex ratio in in vitro studies. Additional sex-specific antigens need to be evaluated for sex ratio estimation in early stage gametocyte preparations

Opportunities for farming in alpine countries – pathways to truly grassland-based beef and milk production in Austria and Switzerland

Farming in the alpine countries of Austria and Switzerland fulfils important economic, socio-cultural and ecological functions for society. However, even though both Austria and Switzerland have increasingly focused their agricultural policy towards ecology, in both countries negative environmental impacts of agriculture still have to be reduced massively

Novel approaches to sex-ratio studies in plasmodium falciparum

Malaria parasites are able to alter the number of male and female gametocytes produced, thereby changing the sex ratio of the reproductive stages. Alteration of the sex ratio has been suggested to increase the reproductive oputput under different conditions, thereby maximizing the transmission success and influencing the epidemiology of this disease. The only existing method for quantifying sex ratios of P. Jalciparum is based on the visual identification of male and female gametocytes by light microscopy. However, this method is limited, as it only allows studying microscopically detectable gametocyte densities found in natural infections and parasites at sub-microscopic levels are not accounted for. A new and more accurate method for estimating sex ratios of P. Jalciparum, which includes large sample sizes obtained by magnetic purification, is described here. In this study light microscopy, immunofluorescent antibody detection (IFA) and quantitative Real-Time PCR (qRT-PCR) were used to estimate sex ratios in P. Jalciparum. The qRT-PCR assay allowed measurement of mRNA expression levels for sexspecific and sexual stage proteins in a multiplex analysis. The female specific protein Pfg377 (PFL2405c) and the putative male specific protein Alpha-tubulin II (PFD1050w) were used to quantify either female or male gametocytes, with Pfs16 (pFD0310w) and Pfs25 (PFlO_0303) serving to quantify the total number of gametocytes present. Results suggest that Alpha-tubulin II is not in fact a male specific protein, whereas Pfg377 was found to be only present in female gametocytes. Different patterns of gene expression during gametocytogenesis have been identified for the four key sexual stage genes in a multiplex assay. Relative expression data of Pfg377 versus Pfs 16 or Pfs25 reveal that the quantification of sex ratios from small volumes of gametocyte-positive blood is possible, and should be applicable for using finger-prick peripheral blood samples from gametocyte carriers

Cyclopropane hydrogenation on Ru and Ru---Au catalysts

The rate of reaction between cyclopropane and hydrogen was measured in a flow system on unsupported Ru, Ru/SiO2, andRu/MgO. The effect of the addition of Au to Ru/MgO was also investigated. The temperature was in the range 30-170 [deg]C; partial pressures were 0.01 cp PH2 3H6 + H2 --> C3H8, (1) cyclo-C3H6 + 2H2 --> CH4 + C2H6, (2) cyclo-C3H6 + 3H2 --> 3CH4. (3)At low temperatures (110 [deg]C), reaction (3) was also detected. Ruthenium particle size and presence of Au on the surface were found to have a strong influence on reaction (3), while reactions (1) and (2) were unaffected. It is suggested that, on Ru, reactions (1) and (2) have the same intermediate or they require a surface site having the same geometry.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23388/1/0000333.pd

Isotopic oxygen exchange on supported Ru and Au catalysts

The isotopic exchange reaction of molecular oxygen is applied to supported ruthenium and gold catalysts. The results on supported ruthenium are similar to those on RuO2. The exchange reaction seems to be unaffected by differences in particle size or nature of the support (MgO or SiO2, respectively). The heterogeneous exchange kinetics deviate from an exponential law. This indicates the presence of nonuniformities on the catalyst surface and/or a contribution of oxygen diffusion. On supported gold, high exchange activity and massive uptake of labeled oxygen by the solid phase are observed. Au/MgO is one order of magnitude more active than Au/SiO2. The activation of support oxygen for the isotopic exchange reaction is related to an interaction between gold and support.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23234/1/0000167.pd

The Henize sample of S stars: IV. New symbiotic stars

The properties of the few symbiotic stars detected among the 66 binary S stars from the Henize sample are discussed. Two stars (Hen 18 and Hen 121) exhibit both a strong blue-violet continuum and strong H_alpha emission (FWHM of 70 km/s), whereas Hen 134 and 137 exhibit weak H_alpha emission. The H_alpha profiles are typical of non-dusty symbiotic stars belonging to class S-3 as defined by Van Winckel et al. (1993, A&AS 102, 401). In that class as in the Henize symbiotic S stars, He I, [N II] or [S II] emission lines are absent, suggesting that the nebular density is high but the excitation rather low. The radial velocity of the centre of the H_alpha emission is identical to that of the companion star (at least for Hen 121 where this can be checked from the available orbital elements), thus suggesting that the H_alpha emission originates from gas moving with the companion star. For Hen 121, this is further confirmed by the disappearance of the ultraviolet Balmer continuum when the companion is eclipsed by the S star. Hen 121 is thus the second eclipsing binary star discovered among extrinsic S stars (the first one is HD 35155). A comparison of the available data on orbital periods and H_alpha emission leads to the conclusion that H_alpha emission in S stars seems to be restricted to binary systems with periods in the range 600 - 1000 d, in agreement with the situation prevailing for red symbiotic stars (excluding symbiotic novae). Symbiotic S stars are found among the most evolved extrinsic S stars.Comment: 10 pages, 9 figures, accepted for publication in Astronomy and Astrophysic

The microstructure of bimetallic Ru---Cu/SiO2 catalysts: A chemisorption and analytical electron microscopy study

Supported bimetallic Ru---Cu/SiO2 catalysts are characterized by transmission electron microscopy, energy dispersive X-ray spectroscopy, electron microdiffraction, and chemisorption. Metal particles up to 4 nm in diameter are bimetallic, while particles larger than 4 nm contain only Cu. Considerable compositional nonuniformity is observed from one individual metal particle to the next. Microdiffraction patterns obtained from individual particles can be attributed to either Ru or Cu suggesting no significant modification in crystallographic structure of either metal component. Addition of Cu to Ru results in a drastic suppression of H2 chemisorption while the extent of O2 chemisorption is not as strongly affected. The suppressed H2 chemisorption capability of Ru in the bimetallic catalysts is an indication of atomic interdispersion of Ru and Cu on the surface of the bimetallic clusters, leading to the break-up of the Ru ensembles which would be necessary for dissociation of molecular hydrogen. The influence of catalyst preparation techniques on the relative interdispersion of Ru and Cu and consequent discrepancies in the Ru---Cu literature are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26092/1/0000168.pd

Estimating soil hydraulic properties using L-band radiometer and ground-penetrating radar

peer reviewedIn this study, we experimentally analyze the feasibility of estimating the soil hydraulic properties from L-band radiometer and ground-penetrating radar (GPR) data. L-band radiometer and ultrawideband off-ground GPR measurements were performed above a sand box in hydrostatic equilibrium with a water table located at different depths. The results of the inversions showed that the radar and radiometer signals contain sufficient information to estimate the soil water retention curve and its related hydraulic parameters with a relatively good accuracy compared to time-domain reflectometry estimates. However, an accurate estimation of the hydraulic parameters was only obtained by considering the saturated water content parameter as known during the inversion. © 2012 IEEE

The research of automobile electric control bus technology based on CAN/LIN mixed protocol

传统汽车电气控制系统中采用的点对点通信方式，对于电子化程度越来越高的汽车而言，将使其线束十分复杂，不仅增加了电气系统成本，而且会因为节点繁多使系统运行可靠性降低。总线网络能够大量减少控制线数，提高可靠性，因此，采用总线控制成为汽车电气控制系统技术发展的必然趋势。如何在汽车上建立基于总线技术的汽车电气控制系统问题自然成为汽车电子领域广受关注的研究热点。西门子公司已经利用PLC完成CAN总线控制系统，由于其具有抗干扰性强、线路简化、传输速率高、系统可任意扩展等优点，正受到国内外高度重视，但其成本高，很多国内汽车生产厂家不能接受。在这种情形下，福州源光亚明电器有限公司（沈阳中顺汽车供应商）委托厦门大...The traditional automobile electrical control system used in peer-to-peer communications, the freetly increased electronic level of automobiel makes the wiring harness more complicated by which not only increases costs, but also lower the reliability of system because of the various nodes. Bus network can decrease the number of the control lines and increase the reliability greatly. Therefore, the...学位：工学硕士院系专业：物理与机电工程学院机电工程系_测试计量技术及仪器学号：2005130175

Bimetallic Ru-Au catalysts: Effect of the support

Ru-Au catalysts supported on SiO2 were characterized by using H2 and O2 chemisorption, wide-angle X-ray scattering, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Catalytic activity was measured for the hydrogenolysis of propane and ethane. The hydrogenolysis activity of ruthenium decreased by two orders of magnitude with addition of gold. This suggested that Ru and Au did not exist as separate particles but formed bimetallic aggregates. Chemisorption and XPS experiments showed a surface composition similar to the bulk. A comparison was made with a previously studied Ru-Au-on-MgO system, on which an enrichment of Ru on the surface of bimetallic Ru-Au clusters was discovered. It is suggested that the strength of the metal-support interaction can affect the surface composition of multimetallic supported systems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24360/1/0000629.pd