Analysis of lichen thin sections by PIXE and STIM using a proton microprobe

In order to better understand the distribution pattern of mineral elements in lichen tissues, thin sections (15 μm) of the foliose, vagrant soil lichen Xanthoparmelia chlorochroa were examined using proton microprobe Particle induced X-ray emission (PIXE). This technique was used to make two-dimensional scans, with 5 μm resolution, across tissue cross sections of the test species. Element maps for Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Cu, Zn, and As have been prepared. Several elements are strongly localized in the element maps. PIXE data are complimented with STIM, light micrographs, and SEM images. Preliminary data suggest that nuclear microprobe techniques may be useful in elucidating element absorption and transport mechanisms in lichens.     

Compact wideband planar monopole antenna

When a shorting pin is added to the planar monopole antenna, an additional mode is excited below the fundamental mode. By optimising the dimensions. A compact wideband antenna can be constructed. The size reduction achievable for this antenna is ~50% compared with an equivalent planar monopole without a shorting pin. Owing to its compact size and wideband performance, this antenna is suitable for use in existing and future mobile communication terminals     

Transmission trap detectors

Polarization-independent trap detectors, in which light is strongly absorbed through multiple reflections, are generically described in terms of the symmetry planes of a cube. The detailed design of a four-element transmission trap with coaxial input and output beams is presented. It is shown that such a trap retains polarization-dependent loss and that six detectors are required for a polarizationindependent transmission trap with coaxial beams.     

Method for ultra-low-level analysis of gold in rocks

A new method for analyzing gold at ultralow concentrations (<10 pg/g) in geological samples has been developed involving HF-aqua regia acid digestion, chromatographic separation of Au from matrix elements using DIBK supported on an inert resin, and analysis by inductively coupled plasma-mass spectrometry (ICPMS). This method has an analytical detection limit of 2 parts per trillion (pg/g), significantly lower than most routinely used methods developed for analysis of ore samples with Au concentrations considerably higher than average crustal abundance ( approximately 2 ng/g). Such methods commonly have detection limits in the low nanogram per gram range. Many areas of geological research including ore genesis, crustal mobility and redistribution, planetary differentiation, and plume volcanism require quantitative analysis of geological materials with much lower Au concentrations. We present a rapid, easy to use method where Au is separated from matrix elements onto extractant primed chromatographic resin and analyzed by quadrupole ICPMS. The method is suitable for the relatively rapid analysis of a large number of samples and is reliable over a wide range of concentrations from picogram to microgram per gram level. Analysis of four different geostandards, GXR1, GXR4, CH-3, and SARM 7, yields concentrations within error of the published concentrations with accuracies of >95%.     

Epidemiological studies regarding the "summer infertility syndrome" of sows in confinement housing

In confined pig herds, located in Northwest-Germany and affiliated to a hybrid breeding organisation, 3 retrospective observational studies were performed to study the effects of "meteorological seasons" on sow fertility. A subsequent field trial was performed to study the effects of photoperiod and of temperature on sow fertility separately. Associations of economically important fertility disorders and season resp. climate categories were determined by adjusted Relative Risks in stratified analysis (observational studies), or by Odds Ratios in the Multiple Logistic Regression Analysis (field trial). Due to nonconsistent seasonal findings in the observational studies and a lack of temperature or photoperiod effects in the field trial we conclude that season and its main contributing climatic factors had no substantial effects on sow fertility in the well-managed herds of our climate zone. Nonclimatic risk factors for the so-called "Summer Infertility Syndrome" are discussed.     

Red shift for CdTe nanoparticle thin films and suspensions during heating

The work that we have conducted shows that temperature affects the wavelength of light emitted from CdTe nanoparticle clusters that are in a suspension or deposited into thin films via a layer-by-layer process. Compared with the stock suspension, the films show an initial photoluminescent shift, of circa 6-8 nm to the red, when the particles are deposited. A shift of circa 6-8 nm is also seen when the suspensions are first heated to 85 degrees C from room temperature (20 degrees C) having been stored in a fridge at 5 degrees C. This shift is non-recoverable. With continual cycling from room temperature to 85 degrees C the suspensions show a slight tendency for the emission to move increasingly to the red; whereas the films show no such tendency. In both cases, the range in emission is ca 10 nm from the room temperature state to 80 degrees C. The intensity of the emission from the film drops abruptly (ca 50% reduction) after one cycle of heating; in the suspension there is an initial increase (ca 3-5% increase) in intensity before it decays. We see that the shift towards the red has been attributed to energy transfer or a rearrangement of the packing of the particles in the thin films. After conducting analysis of the films using scanning probe microscopy we have determined that a change in the morphology is responsible for the permanent shift in emission wavelength associated with prolonged heating. The influence of traps has not been ruled out, but the morphological change in the samples is very large and is likely to be the dominating mechanism affecting change for the red shift at room temperature.     

Dose response modelling of Escherichia coli O157 incorporating data from foodborne and environmental outbreaks

A human dose response model for Escherichia coli O157 would enable prediction of risk of infection to humans following exposure from either foodborne or environmental pathways. However, due to the severe nature of the disease, volunteer human dose response studies cannot be carried out. Surrogate models from Shigella fed to humans and E. coli O157 to rabbits have been utilised but are significantly different to one another. In addition data obtained by animal exposure may not be representative for human beings. An alternative approach to generating and validating a dose response model is to use quantitative data obtained from actual human outbreaks. This work collates outbreak data obtained from global sources and these are fitted using exponential and beta-Poisson models. The best fitting model was found to be the beta-Poisson model using a beta-binomial likelihood and the authors favour the exact version of this model. The confidence levels in this model encompass a previously published Shigella dose response model. The potential incorporation of this model into QMRAs is discussed together with applications of the model to help explain foodborne outbreaks.     

Degossypolized cottonseed flour—the liquid cyclone process

Predictions can be made safely that glanded cottonseed is likely to be with us for quite some time. Worldwide, 20 to 22 million metric tons of glanded cottonseed are produced annually. Hence a workable process for the removal of pigment glands is needed urgently if food-grade products are to be made from cottonseed. A brief history of the development of the Liquid Cyclone Process for the preparation of degossypolized cottonseed flour is outlined. Gossypol is removed in pigment glands via liquid cyclones, thus giving the development its name. The process consists of several unique operations including adequate drying of the meats prior to flaking, fluidizing of the flakes using commercial hexane, comminuting the fluidized slurry in a stone mill and adjusting the solids content of the milled slurry for proper separation of the fine flour from the glands, hulls and coarse meal in the cyclones. Finally, the flour is defatted and washed with hexane on a rotary vacuum filter, dried and desolventized under mild conditions to maintain protein quality. It is visualized that the above operations can be incorporated in a satellite plant operated in conjunction with a parent solvent extraction cottonseed oil mill. Sanitary conditions of the satellite plant will meet the exacting standards of the better food processing plants. Raw material specifications as well as type of plant needed and potential markets are discussed. One of 21 papers presented at the Symposium, “Oilseed Processors Challenged by World Protein Need,” ISF-AOCS World Congress, Chicago, September 1970. Deceased. So. Market. Nutr. Res. Div., ARS, USDA.     

Cysteine adds to lipid hydroperoxide

Cysteine reacts with linoleic acid hydroperoxide to yield several products, some of which were identified as fatty acid-cysteine adducts. The addition was catalyzed by ferric chloride (10⁻⁵ M) by initiating free radical reactions. When isomerically pure 13-hydroperoxy-cis-9,trans-11-octadecadienoic acid and cysteine were reacted in 80% ethanol under N₂, the major adducts were 9-S-cysteine-13-hydroxy-10-ethoxy-trans-11-octadecenoic acid (I) and 9-S-cysteine-10,13-dihydroxy-trans-11-octadecenoic acid (II). When the reaction included both isomers of the hydroperoxide (13-and 9-hydroperoxide) and air, an adduct of 9-oxononanoic acid and cysteine also was isolated. Additional experiments gave information about possible mechanisms of I and II formation.