Cosmogenic-neutron activation of TeO2 and implications for neutrinoless double- β decay experiments

Flux-averaged cross sections for cosmogenic-neutron activation of natural tellurium were measured using a neutron beam containing neutrons of kinetic energies up to ∼800 MeV and having an energy spectrum similar to that of cosmic-ray neutrons at sea level. Analysis of the radioisotopes produced reveals that Ag110m will be a dominant contributor to the cosmogenic-activation background in experiments searching for neutrinoless double-β decay of Te130, such as the Cryogenic Underground Observatory for Rare Events (CUORE) and the Sudbury Neutrino Observatory Plus (SNO+). An estimate of the cosmogenic-activation background in the CUORE experiment has been obtained using the results of this measurement and cross-section measurements of proton activation of tellurium. Additionally, the measured cross sections in this work are also compared with results from semiempirical cross-section calculations

Shoulder injuries in competitive swimmers in KwaZulu-

Objective. To determine the incidence of shoulder injuries in competitive swimmers in KwaZulu-Natal, a province in South Africa. Design. A cross-sectional survey was conducted. A random sample of 96 swimmers from a pool of 300 swimmers registered with first-division clubs affiliated to the KwaZulu-Natal Aquatics Association participated in the study by informed voluntary consent. Data were gathered using a validated questionnaire. Setting. Data were gathered at time trials, races and club meetings. Main measures. Variables monitored included the incidence of shoulder injuries, shoulder pain and proportion of overuse injury. Results. Seventy-one per cent of the swimmers had shoulder pain and 64% reported injury to the shoulder. Forty-six per cent of the swimmers with pain complained of anterior shoulder pain, while 65% of all injuries were due to overuse. The commonest diagnoses included tendonitis (35%), muscle imbalance (29%), impingement (19%) and other (17%). Sixty-nine per cent of the swimmers swam freestyle which was related to 70% of the injuries. Eighty-one per cent of the injured swimmers sought physiotherapy for the shoulder pain. Conclusion. The incidence of shoulder injuries in competitive swimmers is high. This study shows the need for more research into swimming injuries, and the conditioning and rehabilitation of athletes in South Africa. South African Journal of Sports Medicine Vol. 18 (1) 2006: pp. 10-1

Morphology and Growth of Methyl Stearate as a Function of Crystallization Environment

In situ studies of methyl stearate growing from supersaturated n-dodecane, kerosene, and toluene solutions reveal strong evidence that solvent choice influences the crystal morphology and crystal growth kinetics. Crystals with similar habit are observed in all solvents, with the exception of lower supersaturations in kerosene, where a less symmetric morphology was observed. BFDH analysis based on the monoclinic C2 crystal structure of methyl stearate yielded the morphological indexation to be (110), (1–10), (−110), and (−1–10) for the dominant observed habit and (110) (1–10) (−1–10) (−240) (−3–10) for the less symmetric habit observed in kerosene solvent. Measurements of the growth rate for the (110) and (1–10) faces are similar for all solutions ranging from 0.02 to 1.13 μm/s, for significantly lower values of supersaturation in the case of toluene. The tendency of the growth rate dependence on σ was consistent with the Burton-Cabrera-Frank (BCF) growth mechanism in n-dodecane, the Birth and Spread (B&S) mechanism in kerosene and diffusion controlled in toluene solvent

Interaction effects at crossings of spin-polarized one-dimensional subbands

We report conductance measurements of ballistic one-dimensional (1D) wires defined in GaAs/AlGaAs heterostructures in an in-plane magnetic field, B. When the Zeeman energy is equal to the 1D subband energy spacing, the spin-split subband Nup arrow intersects (N+1)down arrow, where N is the index of the spin-degenerate 1D subband. At the crossing of N=1up arrow and N=2down arrow subbands, there is a spontaneous splitting giving rise to an additional conductance structure evolving from the 1.5(2e(2)/h) plateau. With further increase in B, the structure develops into a plateau and lowers to 2e(2)/h. With increasing temperature and magnetic field the structure shows characteristics of the 0.7 structure. Our results suggest that at low densities a spontaneous spin splitting occurs whenever two 1D subbands of opposite spins cross

Shoulder injuries in competitive swimmers in KwaZulu-

Objective. To determine the incidence of shoulder injuries in competitive swimmers in KwaZulu-Natal, a province in South Africa. Design. A cross-sectional survey was conducted. A random sample of 96 swimmers from a pool of 300 swimmers registered with first-division clubs affiliated to the KwaZulu-Natal Aquatics Association participated in the study by informed voluntary consent. Data were gathered using a validated questionnaire. Setting. Data were gathered at time trials, races and club meetings. Main measures. Variables monitored included the incidence of shoulder injuries, shoulder pain and proportion of overuse injury. Results. Seventy-one per cent of the swimmers had shoulder pain and 64% reported injury to the shoulder. Forty-six per cent of the swimmers with pain complained of anterior shoulder pain, while 65% of all injuries were due to overuse. The commonest diagnoses included tendonitis (35%), muscle imbalance (29%), impingement (19%) and other (17%). Sixty-nine per cent of the swimmers swam freestyle which was related to 70% of the injuries. Eighty-one per cent of the injured swimmers sought physiotherapy for the shoulder pain. Conclusion. The incidence of shoulder injuries in competitive swimmers is high. This study shows the need for more research into swimming injuries, and the conditioning and rehabilitation of athletes in South Africa. South African Journal of Sports Medicine Vol. 18 (1) 2006: pp. 10-1

The effect of nutrition and body condition of triplet-bearing ewes during late pregnancy on the behaviour of ewes and lambs

Publishe

Characterisation of spin-incoherent transport in one dimension

Spin-incoherent transport in quantum wires, whereby exchange coupling between neighbouring electrons is overcome by thermal energy, leading to the suppression of spin modes of transport expected in a Luttinger liquid, has been observed in the form of a conductance plateau at e(2)/h in the absence of a magnetic field. We present here further characterisation of this spin-incoherent plateau in a source-drain bias, which causes it to evolves to 0.85 x 2e(2)/h. Laterally shifting the channel and illuminating the sample allows us to verify its origin

Trans-dominant cellular inhibition of DC-SIGN-mediated HIV-1 transmission

BACKGROUND: Dendritic cell (DC) transmission of human immunodeficiency virus (HIV) to CD4+ T cells occurs across a point of cell-cell contact referred to as the infectious synapse. The relationship between the infectious synapse and the classically defined immunological synapse is not currently understood. We have recently demonstrated that human B cells expressing exogenous DC-SIGN, DC-specific intercellular adhesion molecule-3 (ICAM-3)-grabbing nonintegrin, efficiently transmit captured HIV type 1 (HIV-1) to CD4+ T cells. K562, another human cell line of hematopoietic origin that has been extensively used in functional analyses of DC-SIGN and related molecules, lacks the principal molecules involved in the formation of immunological synaptic junctions, namely major histocompatibility complex (MHC) class II molecules and leukocyte function-associated antigen-1 (LFA-1). We thus examined whether K562 erythroleukemic cells could recapitulate efficient DC-SIGN-mediated HIV-1 transmission (DMHT). RESULTS: Here we demonstrate that DMHT requires cell-cell contact. Despite similar expression of functional DC-SIGN, K562/DC-SIGN cells were inefficient in the transmission of HIV-1 to CD4+ T cells when compared with Raji/DC-SIGN cells. Expression of MHC class II molecules or LFA-1 on K562/DC-SIGN cells was insufficient to rescue HIV-1 transmission efficiency. Strikingly, we observed that co-culture of K562 cells with Raji/DC-SIGN cells impaired DMHT to CD4+ T cells. The K562 cell inhibition of transmission was not directly exerted on the CD4+ T cell targets and required contact between K562 and Raji/DC-SIGN cells. CONCLUSIONS: DMHT is cell type dependent and requires cell-cell contact. We also find that the cellular milieu can negatively regulate DC-SIGN transmission of HIV-1 in trans

Garden varieties: how attractive are recommended garden plants to butterflies?

One way the public can engage in insect conservation is through wildlife gardening, including the growing of insect-friendly flowers as sources of nectar. However, plant varieties differ in the types of insects they attract. To determine which garden plants attracted which butterflies, we counted butterflies nectaring on 11 varieties of summer-flowering garden plants in a rural garden in East Sussex, UK. These plants were all from a list of 100 varieties considered attractive to British butterflies, and included the five varieties specifically listed by the UK charity Butterfly Conservation as best for summer nectar. A total of 2659 flower visits from 14 butterfly and one moth species were observed. We performed a principal components analysis which showed contrasting patterns between the species attracted to Origanum vulgare and Buddleia davidii. The “butterfly bush” Buddleia attracted many nymphalines, such as the peacock, Inachis io, but very few satyrines such as the gatekeeper, Pyronia tithonus, which mostly visited Origanum. Eupatorium cannibinum had the highest Simpson’s Diversity score of 0.75, while Buddleia and Origanum were lower, scoring 0.66 and 0.50 respectively. No one plant was good at attracting all observed butterfly species, as each attracted only a subset of the butterfly community. We conclude that to create a butterfly-friendly garden, a variety of plant species are required as nectar sources for butterflies. Furthermore, garden plant recommendations can probably benefit from being more precise as to the species of butterfly they attract