Analytical High-efficiency Spot beam Model for High Throughput Satellites

We develop a simple model for a feed horn with a uniformly excited circular aperture at the focus of an offset paraboloidal reflector antenna and compare it with reflector antenna analyses using combinations of circular waveguide TE1n modes. The model demonstrates the deep dip that can occur at the center of the spot beam for certain feed diameters and it is used in a design procedure that relates the feed and the spot-beam diameter. The model may be extended to include feed horn flare effects

Identifying fear of childbirth in a UK population: qualitative examination of the clarity and acceptability of existing measurement tools in a small UK sample

Background: Fear of childbirth is related to but not synonymous with general anxiety, and represents a superior predictor for maternal and infant outcomes. There is a need to improve the identification and provision of support for women experiencing high fear of childbirth. However it is uncertain as to whether existing measurement tools have appropriate content validity (i.e. cover the relevant domains within the construct), practical utility, and whether they are acceptable for use with a UK population. This study aimed to (1) identify the utility and acceptability of existing measures of fear of childbirth (FOC) with a small UK sample and (2) map the content of existing measures to the key concepts of fear of childbirth established by previous research. Methods: Ten pregnant women; five with high and five with low fear of childbirth participated in a cognitive interview covering four most commonly used measures of fear of childbirth: 1. The Wijma Delivery Expectancy Questionnaire (WDEQ A), 2. The Oxford Worries about Labour Scale (OWLS), 3. The Slade-Pais Expectations of Childbirth Scale – fear subscale (SPECS) and 4. The Fear of Birth scale (FOBS). Each measure was also reviewed by participants for ease and clarity of understanding and acceptability. The measures were then reviewed against the key domains identified in the fear of childbirth literature to ascertain the adequacy of content validity of each measure. Interviews were analysed using thematic analysis for each scale item. Results: All measures except the FOBS, included items that either women did not understand or, if where there was understanding the meanings were inconsistent across women. All measures demonstrated limited acceptability and content validity for the specific construct of FOC. Therefore, none of the measurement tools currently used within the UK met criteria for understanding, acceptability and content validity for measurement of FOC. Conclusions: Findings emphasise a need to develop a specific fear of childbirth tool with good clarity which demonstrates appropriate content validity, and that is acceptable in presentation and length for pregnant women in a UK population

Reflector surface modelling - a European collaboration

The topic of this paper is the work carried out in Work Package 2.3-2 of the EU network ACE. This work package is concerned with the modelling of the surfaces of modern reflector antennas. In particular the problems associated with homogenisation of periodic structures are described together with an application example. An accurate MoM solutions for periodic structure is presented. A new, fast and very efficient interpolation technique for frequency selective surfaces is introduced and linked to high frequency techniques to speed up radiation calculation processes

Comprehensive and comparative metabolomic profiling of wheat, barley, oat and rye using gas chromatography-mass spectrometry and advanced chemometrics

Beyond the main bulk components of cereals such as the polysaccharides and proteins, lower concentration secondary metabolites largely contribute to the nutritional value. This paper outlines a comprehensive protocol for GC-MS metabolomic profiling of phenolics and organic acids in grains, the performance of which is demonstrated through a comparison of the metabolite profiles of the main northern European cereal crops: wheat, barley, oat and rye. Phenolics and organic acids were extracted using acidic hydrolysis, trimethylsilylated using a new method based on trimethylsilyl cyanide and analyzed by GC-MS. In order to extract pure metabolite peaks, the raw chromatographic data were processed by a multi-way decomposition method, Parallel Factor Analysis 2. This approach lead to the semi-quantitative detection of a total of 247 analytes, out of which 89 were identified based on RI and EI-MS library match. The cereal metabolome included 32 phenolics, 30 organic acids, 10 fatty acids, 11 carbohydrates and 6 sterols. The metabolome of the four cereals were compared in detail, including low concentration phenolics and organic acids. Rye and oat displayed higher total concentration of phenolic acids, but ferulic, caffeic and sinapinic acids and their esters were found to be the main phenolics in all four cereals. Compared to the previously reported methods, the outlined protocol provided an efficient and high throughput analysis of the cereal metabolome and the acidic hydrolysis improved the detection of conjugated phenolics

A family of octamer-specific proteins present during mouse embryogenesis: Evidence for germline-specific expression of an Oct factor.

We have analysed various adult organs and different developmental stages of mouse embryos for the presence of octamer-binding proteins. A variety of new octamer-binding proteins were identified in addition to the previously described Oct1 and Oct2. Oct1 is ubiquitously present in murine tissues, in agreement with cell culture data. Although Oct2 has been described as a B-cell-specific protein, similar complexes were also found with extracts from brain, kidney, embryo and sperm. In embryo and brain at least two other proteins, Oct3 and Oct7, are present. A new microextraction procedure allowed the detection of two maternally expressed octamer-binding proteins, Oct4 and Oct5. Both proteins are present in unfertilized oocytes and embryonic stem cells, the latter containing an additional protein, Oct6. Whereas Oct4 was not found in sperm or testis, it is expressed in male and female primordial germ cells. Therefore Oct4 expression is specific for the female germline at later stages of germ cell development. Our results indicate that a family of octamer-binding proteins is present during mouse development and is differentially expressed during early embryogenesis. Protease clipping experiments of Oct4 and Oct1 suggest that both proteins contain similar DNA-binding domains

Octamer binding proteins confer transcriptional activity in early mouse embryogenesis.

Oct4 and Oct5 are two mouse maternally expressed proteins binding to the octamer motif. Both are found in unfertilized oocytes and embryonic stem cells, whereas Oct4 is also found in primordial germ cells. In this study, the activity of the octamer motif was analysed in two embryonic stem cell lines containing Oct4 and Oct5, the teratocarcinoma-derived cell line F9 and the blastocyst-derived cell line D3. It is known that oligomerization of the octamer motif creates a powerful B-cell specific enhancer. As shown here, this oligomerized transcriptional element is also a very strong enhancer in F9 and D3 embryonic stem cells. After differentiation of the stem cells, both enhancer activity and the amount of the octamer binding proteins decrease. An intact octamer stimulates heterologous promoters in embryonic stem cells, whereas mutations in the octamer motif abolish transcriptional stimulation and binding of the octamer factors. The use of transgenic embryos demonstrates transcriptional activation in the inner cell mass but not in the trophoblast of blastocysts. The results indicate that Oct4 and Oct5 are active early in mouse development