This research communication paper addresses the hypothesis that the use of therapeutic alternatives for mastitis, such as intramammary ozone, can cure the disease with lower costs and without harmful residues for human consumption and without formation of microbial resistance like the ones caused by indiscriminate use of antibiotics in dairy farms. The study was performed in 36 mammary quarters from 12 dairy cows with subclinical mastitis grade three. The experimental units were randomly assigned into four groups and each group received a treatment. Treatments comprised (a) 20 μg/ml ozone gas; (b) 40 μg/ml ozone gas; (c) negative control treatment of 12.5 μg/ml ozonated saline and (d) positive control treatment of 100 mg of cephalexin + 100 mg of neomycin + 10 mg of prednisolone, all by intramammary injection. In all quarters, milk was collected before and after the application of treatments for California mastitis test and evaluation of milk composition, somatic cell count, and bacterial cultures. The results indicated that the use of intramammary ozone did have a therapeutic effect, and whilst this was less than that of antibiotics, ozone does confer some advantages. Treated milk had a good composition, the treatment cost was low, milk withdrawal may not be necessary and there is no risk of antibiotic resistance.

Maternal nutrition is critical in mammalian development, influencing the epigenetic reprogramming of gametes, embryos, and fetal programming. We evaluated the effects of different levels of sulfur (S) and cobalt (Co) in the maternal diet throughout the pre- and periconceptional periods on the biochemical and reproductive parameters of the donors and the DNA methylome of the progeny in Bos indicus cattle. The low-S/Co group differed from the control with respect to homocysteine, folic acid, B12, insulin growth factor 1, and glucose. The oocyte yield was lower in heifers from the low S/Co group than that in the control heifers. Embryos from the low-S/Co group exhibited 2320 differentially methylated regions (DMRs) across the genome compared with the control embryos. We also characterized candidate DMRs linked to the DNMT1 and DNMT3B genes in the blood and sperm cells of the adult progeny. A DMR located in DNMT1 that was identified in embryos remained differentially methylated in the sperm of the progeny from the low-S/Co group. Therefore, we associated changes in specific compounds in the maternal diet with DNA methylation modifications in the progeny. Our results help to elucidate the impact of maternal nutrition on epigenetic reprogramming in livestock, opening new avenues of research to study the effect of disturbed epigenetic patterns in early life on health and fertility in adulthood. Considering that cattle are physiologically similar to humans with respect to gestational length, our study may serve as a model for studies related to the developmental origin of health and disease in humans.

Antenna-pattern measurements obtained from a double-metal supra-terahertz-frequency (supra-THz) quantum cascade laser (QCL) are presented. The QCL is mounted within a mechanically micro-machined waveguide cavity containing dual diagonal feedhorns. Operating in continuous-wave mode at 3.5 THz, and at an ambient temperature of ~60 K, QCL emission has been directed via the feedhorns to a supra-THz detector mounted on a multi-axis linear scanner. Comparison of simulated and measured far-field antenna patterns shows an excellent degree of correlation between beamwidth (full-width-half-maximum) and sidelobe content and a very substantial improvement when compared with unmounted devices. Additionally, a single output has been used to successfully illuminate and demonstrate an optical breadboard arrangement associated with a future supra-THz Earth observation space-borne payload. Our novel device has therefore provided a valuable demonstration of the effectiveness of supra-THz diagonal feedhorns and QCL devices for future space-borne ultra-high-frequency Earth-observing heterodyne radiometers.

The analysis of a cylindrical shell with cut-outs, which are reinforced to reduce the stress concentrations, is of importance in many engineering fields, particularly in aircraft structures. The most common assumptions made are that the curvature effect is negligible and that the reinforcement is a compact flexible bead. In the analysis of holes in fuselage shells the neglect of the effect of curvature may lead to serious errors as shown theoretically by Lurie and Vandyke and experimentally by Houghton and Rothwell. In some cases the bending stresses are of the same order as the membrane stresses which themselves may be much higher than the flat plate solution. Lurie obtained a perturbation solution for an unreinforced hole by expanding in powers of curvature parameter β, the results being valid for small values of β. Vandyke extended this solution up to β=4 by using a collocation procedure. In fact, if the collocation method is used it seems possible to obtain a convergent series solution for any β, the only limitations being the shallowness of the shell and the restriction that the deflections are not large.

This article attempts to look forward in the field of aircraft structures, at what is likely to happen, and what current R&D is necessary to achieve this. It becomes clear that structural performance is always improving but that the main drivers are likely to be cost, both capital cost and in-service costs. The capital cost is likely to improve by reducing the design and development time as well as low-cost manufacturing. The use of all components of the synthetic environment are here playing an increasing role. The in-service costs will be reduced by more robust structures and better NDE to automate inspections and lengthen their intervals.

The problem of two identical circular holes in an infinite sheet has been solved by Ling using bipolar co-ordinates and taking advantage of the double symmetry.

The case of any two unequal holes is of interest in that one common situation is that of a small circular hole close to a relatively larger one. In this case it is tempting merely to use the classical single hole solution, first for the larger hole and then for the small hole situated in the “uniform” stress field produced by the larger one. The accuracy of this simple method of superposition is examined.

The notation of Muskhelishvili is followed where the problem consists of finding two functions of the complex variable z=x+iy which are analytic in the region and satisfy the boundary conditions on both holes and at infinity.

In Part I the analysis was given of a circular hole (radius a) reinforced by a compact ring symmetrically placed either side of the shell skin which was assumed to be attached to the ring at its shear centre and centroid. The shell radius/thickness ratio (R/t) was assumed not to be large enough for non-linear effects to be significant.

Universities should be able to do two things which industry may not be able to do, and which should be valuable. We are supposed to be able to have time to think instead of continuously meeting deadlines (this is hardly true anymore) and so we can:

1. 1. Take a risk and embark on a novel idea which may not come off. If the gamble works then we publish and promote it for the general good.

2. 2. Recognise that industry has to meet deadlines, and often produce an answer to a problem which is only partially understood. We can then look at the problem in depth, and with better understanding point the way to future development.

This paper addresses the problem of the complex nature of low velocity impact damage in fabricated structures made of laminated carbon-epoxy composites. The structures chosen are stiffened compression panels since these are the most vulnerable to delamination and debonding. Four ‘top-hat’ stiffened panels were tested and predicted using a dynamic finite element code. The panels all had considerable postbuckling strength so the impact sites were carefully chosen to inflict maximum loss of strength. It was shown that the threshold energy for onset of delamination can be predicted using a dynamic finite element code. The amount of delamination or debonding is also predicted using a crude strength-based criterion, which seems to work only because the maximum impact force is a transient phenomenon of short duration.

We describe a versatile infrared camera/spectrograph, IRIS, designed and constructed at the Anglo-Australian Observatory for use on the Anglo-Australian Telescope. A variety of optical configurations can be selected under remote control to provide several direct image scales and a few low-resolution spectroscopic formats. Two cross-dispersed transmission echelles are of novel design, as is the use of a modified Bowen-Burch system to provide a fast f/ratio in the widest-field option. The drive electronics includes a choice of readout schemes for versatility, and continuous display when the array is not taking data, to facilitate field acquisition and focusing.

The linearity of the detector has been studied in detail. Although outwardly good, slight nonlinearities prevent removal of fixed-pattern noise from the data without application of a cubic linearising function.

Specific control and data-reduction software has been written. We describe also a scanning mode developed for spectroscopic imaging.

The problem of impact damage in laminated composite structures, and the consequent reduction in residual strength, has been a topic of continual research for over two decades. The number of journal papers on the subject now runs into four figures and most have been conscientiously reviewed by Abrate(1991, 1994, 1998). This review is not intended to be in the academic tradition, with emphasis on acknowledging the authorship of all the various research initiatives. Instead we present our opinions so that the reader can appreciate our current understanding of the problem, our capability of predicting by analysis, and the scope of the design tools for avoiding structural damage, or at least designing damage tolerant aerospace structures.