Influence of Ambient Temperature and Relative Humidity on Young Performance Horses

Heat stress is a concern in performance horses due to the daily exercise they receive. To determine the influence of ambient temperature and relative humidity on young performance horses, twelve Quarter Horses (2-3 yr, 444 kg) were utilized in a randomized complete block design for a 5-wk study. Horses were stratified by age, sex, and weight between exercise treatments. Exercise treatments consisted of a morning (AM; n = 6) and an afternoon (PM; n = 6) exercise bout to evaluate the effects of differing temperatures and humidity on physiological characteristics of horses. The mean ambient temperature for the AM exercise bout was 16˚C with a mean relative humidity of 81%, while the mean ambient temperature for the PM exercise bout was 29˚C with a mean relative humidity of 38%. Whole blood lactate (LAC), heart rate (HR), respiration rate (RR), rectal temperature (RT), and circumferences and temperatures of the carpal and metacarpal joints, were measured immediately prior and immediately following the standardized exercise bout on d 14, 21, 28, and 35. HR, RR, and RT were measured 30 min into the recovery period and LAC was measured 2 and 24 h into the recovery period. Circumferences and temperatures of the joints were also measured 24 h into the recovery period. Differences in parameters measured were determined using the GLM procedure of SAS and the 0 min data was used as a covariate to account for differences among horses that existed prior to exercise. RR, RT, and HR were greater (P < 0.01) in the PM group after exercise and in the recovery period compared to the AM group. Two hours into the recovery period, the PM group had a greater LAC (P < 0.05). This indicates that the horses may have had an impaired ability to dissipate heat during the recovery period due to the higher ambient temperatures. Understanding the physiological responses of horses during recovery at different ambient temperatures, may enable industry professionals to modify daily exercise regimens to allow the equine athlete to perform at their full potential and prevent injury or harm to the animal

Pulsed flows at the high-altitude cusp poleward boundary, and associated ionospheric convection and particle signatures, during a cluster - FAST - SuperDARN - sondrestrom conjunction under a southwest

Particle and magnetic field observations during a magnetic conjunction Cluster 1-FAST-Søndrestrøm within the field of view of SuperDARN radars on 21 January 2001 allow us to draw a detailed, comprehensive and self-consistent picture at three heights of signatures associated with transient reconnection under a steady south-westerly IMF (clock angle ≈130◦). Cluster 1 was outbound through the high altitude (∼12RE ) exterior northern cusp tailward of the bifurcation line (geomagnetic Bx>0) when a solar wind dynamic pressure release shifted the spacecraft into a boundary layer downstream of the cusp. The centerpiece of the investigation is a series of flow bursts observed there by the spacecraft, which were accompanied by strong field pertur- bations and tailward flow deflections. Analysis shows these to be Alfven waves. We interpret these flow events as being due to a sequence of reconnected flux tubes, with field-aligned currents in the associated Alfven waves carrying stresses to the underlying ionosphere, a view strengthened by the other observations. At the magnetic footprint of the region of Cluster flow bursts, FAST observed an ion energy- latitude disperison of the stepped cusp type, with individual cusp ion steps corresponding to individual flow bursts. Simultaneously, the SuperDARN Stokkseyri radar observed very strong poleward-moving radar auroral forms (PMRAFs) which were conjugate to the flow bursts at Cluster. FAST was traversing these PMRAFs when it observed the cusp ion steps. The Søndrestrøm radar observed pulsed ionospheric flows (PIFs) just poleward of the convection reversal boundary. As at Cluster, the flow was eastward (tailward), implying a coherent eastward (tailward) motion of the hypothesized open flux tubes. The joint Søndrestrøm and FAST observations indicate that the open/closed field line boundary was equatorward of the convection reversal boundary by ∼2 deg. The unprecedented accuracy of the conjunction argues strongly for the validity of the interpretation of the various signatures as resulting from transient reconnection. In particular, the cusp ion steps arise on this pass from this origin, in consonance with the original pulsating cusp model. The observations point to the need of extending current ideas on the response of the ionosphere to transient reconnection. Specifically, it argues in favor of re-establishing the high-latitude boundary layer downstream of the cusp as an active site of momentum transfer

Inhibition of angiogenesis and suppression of colorectal cancer metastatic to the liver using the Sleeping Beauty Transposon System

<p>Abstract</p> <p>Background</p> <p>Metastatic colon cancer is one of the leading causes of cancer-related death worldwide, with disease progression and metastatic spread being closely associated with angiogenesis. We investigated whether an antiangiogenic gene transfer approach using the <it>Sleeping Beauty </it>(SB) transposon system could be used to inhibit growth of colorectal tumors metastatic to the liver.</p> <p>Results</p> <p>Liver CT26 tumor-bearing mice were hydrodynamically injected with different doses of a plasmid containing a transposon encoding an angiostatin-endostatin fusion gene (Statin AE) along with varying amounts of SB transposase-encoding plasmid. Animals that were injected with a low dose (10 μg) of Statin AE transposon plasmid showed a significant decrease in tumor formation only when co-injected with SB transposase-encoding plasmid, while for animals injected with a higher dose (25 μg) of Statin AE transposon, co-injection of SB transposase-encoding plasmid did not significantly affect tumor load. For animals injected with 10 μg Statin AE transposon plasmid, the number of tumor nodules was inversely proportional to the amount of co-injected SB plasmid. Suppression of metastases was further evident in histological analyses, in which untreated animals showed higher levels of tumor cell proliferation and tumor vascularization than animals treated with low dose transposon plasmid.</p> <p>Conclusion</p> <p>These results demonstrate that hepatic colorectal metastases can be reduced using antiangiogenic transposons, and provide evidence for the importance of the transposition process in mediating suppression of these tumors.</p