Long coherence times for edge spins

We show that in certain one-dimensional spin chains with open boundary conditions, the edge spins retain memory of their initial state for very long times. The long coherence times do not require disorder, only an ordered phase. In the integrable Ising and XYZ chains, the presence of a strong zero mode means the coherence time is infinite, even at infinite temperature. When Ising is perturbed by interactions breaking the integrability, the coherence time remains exponentially long in the perturbing couplings. We show that this is a consequence of an edge "almost" strong zero mode that almost commutes with the Hamiltonian. We compute this operator explicitly, allowing us to estimate accurately the plateau value of edge spin autocorrelator.Comment: 13 pages, 13 figures; references adde

Group behavioural responses of cyprinids to artificial acoustic stimuli: implications for fisheries management

Physical screens are considered a necessary mitigation strategy, restricting access to hazardous areas (e.g. turbine intakes or extraction points) and guiding fish to safer preferred routes. Whilst this precautionary approach is considered fit for purpose, fish interactions at such interfaces have been observed to cause stress, injury and mortalities where high sweeping approach velocities exist. Alternative or collaborative systems may allow for improvements where effectiveness of physical screens alone are limited (e.g. repelling small sized larval/ juvenile stages). A number of acoustic guidance systems have been deployed to date, however efficiencies of such devices are measured using relatively simplistic metrics (e.g.percentage deflection or attraction). Results are highly variable, with some systems observing little to no deflection. Current approaches testing efficiencies are based on methods which provide limited information surrounding the wild behaviour of migratory fish. Furthermore, many studies investigating fish bioacoustics pay limited attention to the entirety of the acoustic field to which fish are exposed. The auditory system is exceptionally important to most aquatic species due to its information provisioning, however various challenges need addressed to extrapolate useful informative data which could develop working behavioural deterrents. Life-history strategies, life-stages, species specific hearing capabilities (i.e. directivity index, sensitivity, and critical ratio), and the propensity for a sound to elicit a repeatedly effective behavioural response (i.e. signal detection theory and effects of habituation) are all areas that require thorough investigation. Utilising model cyprinid species (in possession of morphological hearing specialisations), groups of fish were video recorded under controlled conditions and exposed to differing acoustic stimuli. Behaviours were quantified and analysed, alongside appropriate mapping of tested acoustic fields. This talk summarises past and ongoing experiments of a PhD project investigating group behavioural responses to sound. Results may better inform fisheries engineering design of acoustic behavioural deterrents for conservation and control purposes

The use and effectiveness of the eLib subject gateways: a preliminary investigation

Internet subject gateways were set up under the Electronic Libraries Programme (eLib) in order to address some of the problems of searching the Internet which have been identified by information professionals, i.e. locating relevant, good quality information. This preliminary study examines the extent to which academics in two universities use three eLib subject gateways (EEVL, OMNI and SOSIG). The results are generally encouraging for the eLib programme, but it is necessary for the gateways to be more effectively promoted. The study also found that academics do not have the same misgivings about the general search engines as the information professionals and seem to use them more readily than the gateways

Plantain (\u3cem\u3ePlantago lanceolata\u3c/em\u3e) in Herb and Legume Pastures Increases Lamb Growth Relative to Perennial Ryegrass and White Clover Pasture

Increased use of plantain (Plantago lanceolata) by New Zealand farmers has created a demand for a more complete understanding of the performance and manage-ment of plantain by itself and in various combinations with chicory (Cichorium intybus) and legumes such as white clover (Trifolium repens) and red clover (T. pratense). The objective of this study was to evaluate lamb finishing on plantain by itself and combined with chicory, white and red clover as part of a research programme to develop a temperate perennial pasture superior in animal performance to perennial ryegrass and white clover pasture for sheep production systems (Kemp et al. 2010)

Herb and Clover Mixes Increase Average Daily Gain (ADG) of Finishing Lambs in Different Seasons

Approximately half of the usable land area in New Zealand is under grasslands (Saggar 2001). Production of lamb meat is seasonal in New Zealand (Fisher 2004) with the majority of lambs born in the spring and slaughtered in late summer and autumn depending on the international demand (Clemens and Babcock 2004) and pasture growth pattern. Finishing lambs outside this window using high quality pastures would help to facilitate a continuous supply of meat to the domestic and international markets. Charlton and Belgrave (1992) and Kemp et al. (2010) reported that the use of herb-clover mixes instead of perennial ryegrass/white clover swards would facilitate finishing lambs to a high carcass weight or in a shorter time period. Therefore, a research was undertaken in four different seasons: early spring, late spring, summer and autumn during 2011/2012 with the hypothesis that the average daily gain (ADG) and average live weight per ha per day of finishing lambs would be greater in herb-clover mixes than on a perennial ryegrass/white clover sward

Frequency Content of Heart Sounds and Systolic Murmurs in Patients with Porcine Bioprosthetic Valves: Diagnostic Value for the Early Detection of Valvular Degeneration

The frequency content of heart sounds and murmurs in patients with implanted bioprosthetic valves may reveal evidence of degenerative changes before such changes are clinically apparent. An increased dominant frequency of the heart sound caused by a bioprosthetic valve in either the aortic or mitral positions suggests stiffening of the leaflets. While a musical systolic murmur of a bioprosthetic valve in the mitral position suggests flutter from a torn, insufficient leaflet, limited observations of musical systolic murmurs in the aortic position do not seem to indicate a degenerated valve

Seasonal Influence on Botanical Composition of Plantain, Chicory, White- and Red-Clover Based Herbage Mixes

Use of herb based sward mixes that are productive in different weather conditions could be an effective option to provide feed requirements for finishing lambs year round compared to ryegrass (Lolium perenne L.)/white clover (Trifolium repens L.) sward in New Zealand (Kemp et al., 2010). Herbs such as plantain (Plantago lanceolata L.) and chicory (Cichorium intybus L.) and the legumes such as white clover and red clover (Trifolium pratense L.) as pure swards are known to improve lamb performance compared to ryegrass/white clover. Therefore, there is scope to have herb-clover mixes to enhance post-weaning lamb performance. However, one significant limitation in the use of these herbages is the seasonality of their production. A further issue could be their persistence and poor winter growth (Moloney and Milne, 1993). Botanical composition of a sward mix changes depending on the grazing management system. Herbs such as plantain and chicory are susceptible to winter grazing and treading damage affecting their proportion in a sward mix. A sward’s botanical composition (legumes or grasses, leaf or stem materials, dead matter or weeds) and morphological composition (growth in different seasons), would likely affect the nutrient composition and lamb production (Lambert and Litherland, 2000). Therefore, it is essential to observe potential changes within and across seasons of the botanical composition in herb clover sward mixes

miR-1-5p targets TGF-βR1 and is suppressed in the hypertrophying hearts of rats with pulmonary arterial hypertension.

The microRNA miR-1 is an important regulator of muscle phenotype including cardiac muscle. Down-regulation of miR-1 has been shown to occur in left ventricular hypertrophy but its contribution to right ventricular hypertrophy in pulmonary arterial hypertension are not known. Previous studies have suggested that miR-1 may suppress transforming growth factor-beta (TGF-β) signalling, an important pro-hypertrophic pathway but only indirect mechanisms of regulation have been identified. We identified the TGF-β type 1 receptor (TGF-βR1) as a putative miR-1 target. We therefore hypothesized that miR-1 and TGF-βR1 expression would be inversely correlated in hypertrophying right ventricle of rats with pulmonary arterial hypertension and that miR-1 would inhibit TGF-β signalling by targeting TGF-βR1 expression. Quantification of miR-1 and TGF-βR1 in rats treated with monocrotaline to induce pulmonary arterial hypertension showed appropriate changes in miR-1 and TGF-βR1 expression in the hypertrophying right ventricle. A miR-1-mimic reduced enhanced green fluorescent protein expression from a reporter vector containing the TGF-βR1 3'- untranslated region and knocked down endogenous TGF-βR1. Lastly, miR-1 reduced TGF-β activation of a (mothers against decapentaplegic homolog) SMAD2/3-dependent reporter. Taken together, these data suggest that miR-1 targets TGF-βR1 and reduces TGF-β signalling, so a reduction in miR-1 expression may increase TGF-β signalling and contribute to cardiac hypertrophy