Percolation and jamming in random sequential adsorption of linear segments on square lattice

We present the results of study of random sequential adsorption of linear segments (needles) on sites of a square lattice. We show that the percolation threshold is a nonmonotonic function of the length of the adsorbed needle, showing a minimum for a certain length of the needles, while the jamming threshold decreases to a constant with a power law. The ratio of the two thresholds is also nonmonotonic and it remains constant only in a restricted range of the needles length. We determine the values of the correlation length exponent for percolation, jamming and their ratio

Investigation into the development of novel lanthanide-based luminescent colorants for application to textiles and paper materials

YesThis article describes the synthesis and application of lanthanide-based luminophores for visualisation under short wavelength ultraviolet (UV) activation (typically 254 nm). Luminophores are chemical compounds which re-emit light of longer wavelength than typical fluorescence and phosphorescence, following photoexcitation, because of efficient energy transfer from the ligands to the lanthanide ion emission levels. The luminophores described in this article are all derived from europium and terbium metal complexes and cover the complete colour gamut. Selection of appropriate ligands allows for water solubility or water insolubility (if required pigment or disperse “dye” applications). Similar to dyeing or printing processes, the anionic complexes can be applied to polyamide fibres or to cellulosic fibres, whereas dispersions of the non-ionic complexes are suitable for polyester or cellulose acetate fibre application. The water-soluble derivatives are also suitable for ink-jet printing and the water-insoluble derivatives are suitable for lithographic or intaglio paper printing. The novel complexes are excited by radiation below 300 nm and thus cannot be activated by sunlight (the earth's atmosphere prevents light below about 300 nm reaching the surface). Accordingly, the photo-stability of the dyed materials and prints obtained is excellent. These materials could be used in security marking applications, for example bank-notes and passports, where they could replace the current fluorophores that are rendered visible under near UV light (typically 365 nm) illumination but exhibit relatively poor photo-stability. The development of an RGB (red, green and blue) colour palette for inkjet printing based on these innovative luminophores will significantly support the design of digitally printed security features.The research was part funded by Inovink Ltd and theWorshipful Company of Clothworkers of the City of London

Superovulation in cattle usingPMSG followed by PMSGmonoclonal antibodies

The advantages of using pregnant mares' serum gonadotrophin (PMSG) to stimulate increased preovulatory follicular development are that it is available in large quantities at low cost, and can be administered as a single dose because of its long half-life. The long half-life, however, can have dis¬advantages since it may cause over and/or prolonged stimulation, leading to a second wave offollic¬ular development after ovulation and a secondary rise in oestradiol-l 7 p. The latter may interfere with embryo quality. PMSG antiserum I has been extensively tested in an effort to selectively remove PMSG from the peripheral blood ofPMSG stimulated cattle after the initial phase of follicular stimulation but before the secondary post-ovulatory phase of stimulation. This neutralisation of PMSG with PMSG anti¬serum prevents the secondary development of ovarian follicles and the accompanying rise in oestra¬diol-17 p; however, the evidence regarding the effect on the number of usable embryos recovered is conflicting. The best results, in this respect, have been obtained when PMSG antiserum was admin¬istered 5-6 h after the preovulatory LH peak but this event is difficult to assess in practice. Adminis¬tration of PMSG antiserum at a fixed time in relation to the use of either PMSG or a synchronising injection of a prostaglandin analogue, or in relation to the onset of behavioural oestrus is unsatisfac¬tory because of the variability of the timing of the LH peak in relation to these events. It may, how¬ever, be possible to use the preovulatory peak of oestradiol-l 7 p as a marker for the administration of PMSG antiserum

Pregnancy diagnosis using bovine pregnancy-associated glycoprotein in purebred beef heifers mated at a first or second synchronised oestrus.

editorial reviewe

Half-life of serum bovine pregnancy-associated glycoprotein (bPAG), post-partum anoestrus and performance of beef cows.

editorial reviewe