In the hyperbolic theory of special relativity is space also hyperbolic?

In the hyperbolic theory of special relativity the space of velocities, the kinematic space, is hyperbolic of radius of negative curvature c the velocity of light. Space itself could be either Euclidean or hyperbolic. Whether space is hyperbolic is an important question for cosmology, philosophy and the axioms of special relativity. This paper considers consequences of it being hyperbolic including an estimate of the deviation from parallelism at terrestrial distances

Establishing a virtual building & construction site for education and training

Field trips, site visits and industrial placements can make an important educational contribution by bridging the theory–practice gap through the provision of vital contextual information and the promotion of insights not easily understood in the normal classroom. But, in the Building and Construction industries it is increasingly difficult to arrange actual sites visits. An alternative web site solution is described in this paper. The City University site, the Virtual Building and Construction Environment, is part of a much larger group of sites known as CIVCAL, developed by four Hong Kong universities. Access is provided to three tours, three building sites, information in a Design Office and Production Office as well as details of some outstanding construction projects in Hong Kong. The paper explains the underlying design methodology and production techniques, including features incorporated to promote learning and comprehension

Asymptotics of 4d spin foam models

We study the asymptotic properties of four-simplex amplitudes for various four-dimensional spin foam models. We investigate the semi-classical limit of the Ooguri, Euclidean and Lorentzian EPRL models using coherent states for the boundary data. For some classes of geometrical boundary data, the asymptotic formulae are given, in all three cases, by simple functions of the Regge action for the four-simplex geometry.Comment: 10 pages, Proceedings for the 2nd Corfu summer school and workshop on quantum gravity and quantum geometry, talk given by Winston J. Fairbair

Herd health status and management practices on 16 Irish suckler beef farms

peer-reviewedBackground: There have been few studies published internationally which document herd health management practices in suckler beef herds and no published Irish studies. The study objective was to document herd health status and management practices on sixteen Irish suckler beef herds over a two year period (2009–2010). The farms used in the study were part of the Teagasc BETTER farm beef programme. The mean (s.d.) herd size, stocking rate and farm size was 68 cows (27.6), 2.0 LU/ha (0.3) and 64.3 (21.6) adjusted hectares, respectively. Two questionnaires were designed; 1) a farmer questionnaire to collect information on farm background and current herd health control practices and 2) a veterinary questionnaire to collect information on the extent of animal health advice given by veterinarians to their clients and identification of any on-farm herd health issues. Results: Dystocia, calf pneumonia, and calf diarrhoea, in that order, were identified as the primary herd health issues in these Irish suckler beef herds. In addition, substantial deficiencies in biosecurity practices were also identified on these farms. Conclusions: The findings of this study may serve as the focus for future research in animal health management practices in Irish suckler beef herds

Artificial fertilization of the eggs, and rearing and identification of the larvae of the anchoveta, Cetengraulis mysticetus

ENGLISH: The anchoveta, Cetengraulis mysticetus (Günther), is an important bait fish used to capture tunas in the Eastern Tropical Pacific Ocean. Contributions to the early life history of this species in the Gulf of Panama were made by Simpson (1959), who was able to identify deductively the planktonic egg of the anchoveta from 10 other anchovy eggs concurrently present. He also reared these planktonic eggs in the laboratory and described the resultant larvae to the age of 48 hours after hatching. Because of the lack of differences among the anchovy larvae, this description does not permit the identification of anchoveta larvae from those of other engraulid species. Furthermore, while adult specimens are easily recognized, up to the present it has not been possible to extend the identification of the juvenile anchoveta to specimens smaller than about 25 mm. The purpose of this study, therefore, was to identify anchoveta from the time of hatching to about 25 mm. SPANISH: La anchoveta, Cetengraulis mysticetus (Günther), es un importante pez de carnada que se emplea en la captura de los atunes en el Océano Pacífico Oriental Tropical. Simpson (1959) logró identificar deductivamente el huevo planctónico de la anchoveta al separarlo de otros diez huevos de anchoas que se encuentran al mismo tiempo, contribuyendo de esta manera a conocer los primeros estados de la historia natural de esta especie en el Golfo de Panamá. El también estableció un criadero en el laboratorio con estos huevos planctónicos y describió las larvas resultantes hasta la edad de 48 horas después de la eclosión. Debido a que no hay diferencias entre las larvas de las anchoas, esta descripción no permite identificar las larvas de la anchoveta de las otras especies de engráulidos. Más aun, a pesar de que los especímenes adultos son fácilmente reconocibles, hasta ahora no ha sido posible identificar la anchoveta juvenil de menos de unos 25 mm. Consecuentemente, el propósito del presente estudio ha sido el de identificar al anchoveta desde el momento de la eclosión hasta que tiene unos 25 mm

Zincate-free, electroless nickel deposition on aluminum bond pads

A zincate-free electroless nickel deposition on aluminum bond pads is investigated. A three-step, etch, rinse, and electroless plating, is demonstrated for deposition on aluminum bond pads patterned with polyimide. The chemicals used are compatible with this dielectric material. The deposition has been achieved with good selectivity, uniformity, and deposition rate at 40 × 40   μ m aluminum bond pads. The adhesion and contact resistance were also determined and improved through anneals in the range 200-400°C for 1 h. The optimized condition for adhesion and contact resistance was an anneal at 400°C. The combination of a nickel hypophosphite reducing agent and the additives used leads to an active plating bath in the early stages of deposition, by comparison with commercial solutions, and hence, good coverage of the aluminum bond pad using the simplified process

Nematode control in suckler beef cattle over their first two grazing seasons using a targeted selective treatment approach

peer-reviewedBackground With concerns over the development of anthelmintic resistance in cattle nematode populations, we must re-examine our approach to nematode control in cattle. Targeted selective treatments (TST), whereby individual animals are treated instead of entire groups, are being investigated as an alternative. The study objective was to determine if anthelmintic usage could be reduced using a TST-based approach to nematode control in spring-born suckler beef cattle over their first and second grazing seasons (SGS) without affecting performance. In the first grazing season (FGS), 99 calves with an initial mean (s.d.) calf age and live weight on day 0 (June 28th 2012) of 107 (23.1) days and 160 (32.5) kg, respectively, were used. The study commenced on day 0 when calves were randomised and allocated to one of two treatments; 1), standard treatment (control) and 2), TST. Control calves were treated subcutaneously with ivermectin on days 0, 41 and 82 in the FGS. All calves were treated with ivermectin on day 124 and housed on day 133. In the SGS, only heifer calves from the FGS were used and control heifers were treated with ivermectin on day 393. Animals were weighed, blood and faecal sampled every three weeks. The TST animals were treated with ivermectin if thresholds based on a combination of plasma pepsinogen concentrations, faecal egg count and/or the presence of Dictyocaulus viviparus larvae in faeces (FGS only) were reached. Results No TST calves reached the treatment threshold criteria in the FGS. The FGS average daily live weight gain (ADG ± s.e.m.) for control and TST group calves was 0.89 ± 0.02 kg and 0.94 ± 0.02 kg day−1, respectively (P = 0.17). In the SGS, all heifers were treated with ivermectin on day 431 due to clinical signs of respiratory disease. The ADG for control and TST heifers from turnout on day 321 to day 431 was 0.90 ± 0.04 and 0.80 ± 0.04 kg day−1, respectively (P = 0.03). Conclusions Spring-born FGS suckler beef calves require minimal anthelmintic treatment to maintain performance. In contrast, clinical parasitic disease may develop in the SGS unless appropriate anthelmintic treatment is provided