Impacts of Fire and Vertebrate Herbivores on Plant Community Characteristics and Soil Processes in a Coastal Marsh of Eastern Louisiana, United States of America.

Both vertebrate herbivores and fire have long been known to have dramatic and important effects on wetlands. In the first part of this study, conducted in the Pearl River Basin coastal marshes of Louisiana, the interaction between the effects of mammalian herbivores, especially nutria and wild boar, and fire was examined in three marsh community types: those dominated by Sagittaria lancifolia, Panicum virgatum, or Spartina patens/Scirpus americanus. Overall, above-ground biomass was reduced by burning but increased by fencing. Richness only increased in plots that were both burned and fenced. In the three communities, only Scirpus americanus cover was enhanced by fencing. Fencing reduced Spartina patens cover in the Panicum and Sagittaria marshes. Cover of Panicum virgatum in the Panicum marsh and Sagittaria lancifolia and Vigna luteola in the Sagittaria marsh were all enhanced by burning. Therefore, burning shifts the communities from S. patens to S. lancifolia, V. luteola. In the second part of this study, exclosures were used in conjunction with feldspar and benchmark techniques to measure the effects of herbivore exclusion on vertical soil accretion, marsh elevation changes, and litter production. Overall, vertical soil accretion appears to be contributing sufficient material to offset the effects of subsidence in both the grazed and ungrazed plots. However, the examination of the root zone over time indicates that not only is this layer expanding and contracting, but it appears that it also is contributing to soil elevation change. The third part of this study was conducted in order to assess the impact of herbivores on plant biomass, cover, and species richness. Biomass was four times as great in exclosed plots for both Spartina patens and Scirpus americanus compared to the control plots. A detrended correspondence analysis revealed that exclusion of grazers resulted in overall shifts in community composition. Species richness increased in the grazed plots after fifteen months and decreased in the ungrazed plots, with a total difference in richness of two species. Overall, the results suggest that grazing in the system selectively alters species composition and increases species diversity

Gamma-Ray Observations of GRO J1655-40

The bright transient X-ray source GRO J1655-40 = XN Sco 1994 was observed by the OSSE instrument on the Compton Gamma Ray Observatory (GRO). Preliminary results are reported here. The initial outburst from GRO J1655-40 was detected by BATSE on 27 Jul 1994. OSSE observations were made in five separate viewing periods starting between 4 Aug 1994 and 4 Apr 1995. The first, third, and fifth observations are near the peak luminosity. In the second observation, the source flux had dropped by several orders of magnitude and we can only set an upper limit. The fourth observation is a weak detection after the period of maximum outburst. In contrast with other X-ray novae such as GRO J0422+32, the spectrum determined by OSSE is consistent with a simple power law over the full range of detection, about 50 - 600 keV. The photon spectral index is in the range of -2.5 to 2.8 in all of the observations. We set an upper limit on fractional rms variation \u3c5% in the frequency range 0.01 – 60 Hz. No significant narrow or broad line features are observed at any energy

LOWER LIMB MOVEMENT VARIABILITY DURING RUGBY UNION PLACE KICKING

Place kicking accuracy has a significant impact rugby match outcomes. This project investigated the variability of the kicking leg kinematics and the consistency on the stance and kicking foot positions at ball contact in a group of seven highly proficiency kickers. Kinematic data were collected using a high speed motion capture system (500 Hz) during six simulated attempts on goal. Movement variability was assessed using Normalised Root Mean Square of the swing leg pelvis, hip and knee kinematics, and the standard deviation of the stance foot at opposite plant and kicking foot at ball contact (BC). Results suggest a strong relationship between stance foot placement, swing leg movement variability and the orientation of the kicking foot at BC. This pilot study highlighted the importance of movement variability in determining consistent foot placement at BC in place kicking

Winter Home Range and Habitat Use of the Virginia Northern Flying Squirrel (Glaucomys sabrinus fuscus)

We radio-tracked two male and one female Virginia northern flying squirrels (Glaucomys sabrinus fuscus) in the Allegheny Mountains of West Virginia at Snowshoe Mountain Resort, in winter 2003 and Canaan Valley National Wildlife Refuge in winter 2004, respectively, to document winter home range and habitat use in or near ski areas. Male home range size in the winter was larger than that reported for males during summer and fall, whereas the female home range we observed was smaller than those reported for summer and fall. However, winter habitat use was similar to summer and fall habitat use reported in other studies. Virginia northern flying squirrels foraged and denned in both red spruce (Picea rubens)-dominated forests and northern hardwood forests; however, selection of red spruce-dominated forests and open areas was greater than expected based on availability. Use of northern hardwood forest occurred less than expected based on availability. Male squirrels denned near, and routinely crossed, downhill ski slopes and unimproved roads during foraging bouts, whereas the female approached, but did not cross forest edges onto roads or trails

Converting gas-driven ventilators from oxygen to air

Published version, Accepted version (12 month embargo), Submitted versio