The Beagle landing site in Isidis Planitia

The Mars probe Beagle 2 will land in Isidis Planitia. This region satisfies the engineering constraints and has evidence for particularly volatile-rich subsoil. Isidis provides a suitable place for the lander to search for H2O and organic matter

Orbit Determination Accuracy Analysis of the Magnetospheric Multiscale Mission During Perigee Raise

The Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF) will provide orbit determination and prediction support for the Magnetospheric Multiscale (MMS) mission during the mission's commissioning period. The spacecraft will launch into a highly elliptical Earth orbit in 2015. Starting approximately four days after launch, a series of five large perigee-raising maneuvers will be executed near apogee on a nearly every-other-orbit cadence. This perigee-raise operations concept requires a high-accuracy estimate of the orbital state within one orbit following the maneuver for performance evaluation and a high-accuracy orbit prediction to correctly plan and execute the next maneuver in the sequence. During early mission design, a linear covariance analysis method was used to study orbit determination and prediction accuracy for this perigee-raising campaign. This paper provides a higher fidelity Monte Carlo analysis using the operational COTS extended Kalman filter implementation that was performed to validate the linear covariance analysis estimates and to better characterize orbit determination performance for actively maneuvering spacecraft in a highly elliptical orbit. The study finds that the COTS extended Kalman filter tool converges on accurate definitive orbit solutions quickly, but prediction accuracy through orbits with very low altitude perigees is degraded by the unpredictability of atmospheric density variation

Land resource assessment of Northern Belize (NRI Bulletin 43, Volume 1 of 2)

The land resource assessment was undertaken from July 1989 to June 1990 by the Natural Resources Institute (NRI) of the Overseas Development Administration (ODA), assisted by Mr. A. C. S. Wright, and Dr. M. Holder of Central Farm. The main object of the survey was to produce an updated land suitability assessment of Orange Walk, Corozal, Belize and Cayo districts which had not already been surveyed by Jenkin et al. (1976) and King et al. (1989). In addition, this survey would provide a land suitability assessment for the Belize Valley based on the soil mapping of )en kin et al. Thus, together with the land resource assessments of Toledo and Stann Creek districts (King et al., 1986, 1989 respectively), a land suitability assessment for the whole of Belize is now available

Land resource assessment of Northern Belize (NRI Bulletin 43, Volume 2 of 2)

The land resource assessment was undertaken from July 1989 to June 1990 by the Natural Resources Institute (NRI) of the Overseas Development Administration (ODA), assisted by Mr. A. C. S. Wright, and Dr. M. Holder of Central Farm. The main object of the survey was to produce an updated land suitability assessment of Orange Walk, Corozal, Belize and Cayo districts which had not already been surveyed by Jenkin et al. (1976) and King et al. (1989). In addition, this survey would provide a land suitability assessment for the Belize Valley based on the soil mapping of )en kin et al. Thus, together with the land resource assessments of Toledo and Stann Creek districts (King et al., 1986, 1989 respectively), a land suitability assessment for the whole of Belize is now available

The ionized nebula surrounding the red supergiant W26 in Westerlund 1

We present Hα images of an ionized nebula surrounding the M2-5Ia red supergiant (RSG) W26 in the massive star cluster Westerlund 1. The nebula consists of a circumstellar shell or ring ∼0.1 pc in diameter and a triangular nebula ∼0.2 pc from the star that in high-resolution Hubble Space Telescope images shows a complex filamentary structure. The excitation mechanism of both regions is unclear since RSGs are too cool to produce ionizing photons and we consider various possibilities. The presence of the nebula, high stellar luminosity and spectral variability suggests that W26 is a highly evolved RSG experiencing extreme levels of mass-loss. As the only known example of an ionized nebula surrounding an RSG W26 deserves further attention to improve our understanding of the final evolutionary stages of massive stars

Associations between sole ulcer, white line disease and digital dermatitis and the milk yield of 1824 dairy cows on 30 dairy cow farms in England and Wales from February 2003–November 2004

The milk yields of 1824 cows were used to investigate the effect of lesion-specific causes of lameness, based on farmer treatment and diagnosis of lame cows, on milk yield. A three level hierarchical model of repeated test day yields within cows within herds was used to investigate the impact of lesion-specific causes of lameness (sole ulcer, white line disease, digital dermatitis and other causes) on milk yield before and after treatment compared with unaffected cows. Cattle which developed sole ulcer (SU) and white line disease (WLD) were higher yielding cattle before they were diagnosed. Their milk production fell to below that of the mean of unaffected cows before diagnosis and remained low after diagnosis. In cattle which developed digital dermatitis (DD) there was no significant difference in milk yield before treatment and a slightly raised milk yield immediately after treatment. The estimated milk loss attributable to SU and WLD was approximately 570kg and 370kg respectively. These results highlight that specific types of lameness vary by herds and within herds they are associated with higher yielding cattle. Consequently lesion-specific lameness reduction programmes targeting the cow and farm specific causes of lameness might be more effective than generic recommendations. They also highlight the importance of milk loss when estimating the economic impact of SU and WLD on the farms profitability

Generation of vortices and observation of Quantum Turbulence in an oscillating Bose-Einstein Condensate

We report on the experimental observation of vortex formation and production of tangled vortex distribution in an atomic BEC of Rb-87 atoms submitted to an external oscillatory perturbation. The oscillatory perturbations start by exciting quadrupolar and scissors modes of the condensate. Then regular vortices are observed finally evolving to a vortex tangle configuration. The vortex tangle is a signature of the presence of a turbulent regime in the cloud. We also show that this turbulent cloud has suppression of the aspect ratio inversion typically observed in quantum degenerate bosonic gases during free expansion.Comment: to appear in JLTP - QFS 200

The Minimally Tuned Minimal Supersymmetric Standard Model

The regions in the Minimal Supersymmetric Standard Model with the minimal amount of fine-tuning of electroweak symmetry breaking are presented for general messenger scale. No a priori relations among the soft supersymmetry breaking parameters are assumed and fine-tuning is minimized with respect to all the important parameters which affect electroweak symmetry breaking. The superpartner spectra in the minimally tuned region of parameter space are quite distinctive with large stop mixing at the low scale and negative squark soft masses at the high scale. The minimal amount of tuning increases enormously for a Higgs mass beyond roughly 120 GeV.Comment: 38 pages, including 2 appendices, 8 figure