Field boundary habitats and their contribution to the area of semi-natural habitats on lowland farms in east Galway, western Ireland

peer-reviewedSustainable agriculture and the provision of environmental public goods are key deliverables for European farming and food production. Farmland biodiversity, cultural landscapes, soil functionality and climate stability are among the environmental public goods provided through agriculture. Future Common Agricultural Policy (CAP) direct payments are intended to be more targeted at the provision of these agricultural deliverables. Field boundaries are an example of such deliverables. They are widespread features that have both environmental and aesthetic functions in farmed landscapes. However, research on their variety, density and contribution to semi-natural habitat cover on farms in Ireland is lacking. This study investigates the diversity and density of all field boundary habitat types on 32 lowland farms in east County Galway, western Ireland. A total of 286km of field boundaries were surveyed across six study sites. Five types of field boundary habitats were recorded. The density of field boundaries on the farms studied was high and could have positive implications for delivery of environmental public goods and sustainable farming metrics. In more intensively farmed areas, field boundaries were the only remaining semi-natural habitat on some farms highlighting the need to retain, and improve the ecological quality, of these features. The condition of one field boundary type (hedgerows) was also investigated in further detail. While the density of field boundaries was high on many of the surveyed farms, we found that the hedgerows on these farms were not necessarily in good condition for wildlife

Pigmented villonodular synovitis associated with pathological fracture of the odontoid and atlantoaxial instability

Journal ArticlePPigmented villonodular synovitis (PVNS) is a proliferative disorder of the synovium with a predisposition for the appendicular skeleton. Rarely PVNS can arise from the spine, where this disorder usually presents with localized or radicular pain secondary to involvement of the posterior elements. The authors report the case of an 82-year-old woman who presented with long-standing neck pain and acute upper-extremity numbness and weakness. Computed tomography imaging revealed a mixed sclerotic and lucent lesion affecting the dens and right lateral mass of C-2. There was also a pathological fracture at the base of the dens with 8 mm of anterior dens displacement. Magnetic resonance imaging demonstrated a diffusely infiltrative process that was nonenhancing. Because of instability, the patient underwent transarticular screw fixation, and a biopsy of the lesion was also performed at this time. Histopathological analysis was consistent with a diagnosis of PVNS. To the authors' knowledge, this is the first report of PVNS involving the C-2 vertebra or causing a pathological fracture

Cervical end of an occipitocervical fusion: a biomechanical evaluation of 3 constructs

Journal ArticleObject. Stabilization with rigid screw/rod fixation is the treatment of choice for craniocervical disorders requiring operative stabilization. The authors compare the relative immediate stiffness for occipital plate fixation in concordance with transarticular screw fixation (TASF), C-1 lateral mass and C-2 pars screw (C1L-C2P), and C-1 lateral mass and C-2 laminar screw (C1L-C2L) constructs, with and without a cross-link. Methods. Ten intact human cadaveric spines (Oc-C4) were prepared and mounted in a 7-axis spine simulator. Each specimen was precycled and then tested in the intact state for flexion/extension, lateral bending, and axial rotation. Motion was tracked using the OptoTRAK 3D tracking system. The specimens were then destabilized and instrumented with an occipital plate and TASF. The spine was tested with and without the addition of a cross-link. The C1L-C2P and C1L-C2L constructs were similarly tested. Results. All constructs demonstrated a significant increase in stiffness after instrumentation. The C1L-C2P construct was equivalent to the TASF in all moments. The C1L-C2L was significantly weaker than the C1L-C2P construct in all moments and significantly weaker than the TASF in lateral bending. The addition of a cross-link made no difference in the stiffness of any construct. Conclusions. All constructs provide significant immediate stability in the destabilized occipitocervical junction. Although the C1L-C2P construct performed best overall, the TASF was similar, and either one can be recommended. Decreased stiffness of the C1L-C2L construct might affect the success of clinical fusion. This construct should be reserved for cases in which anatomy precludes the use of the other two

Castleman disease of the spine mimicking a nerve sheath tumor

Journal ArticleCastleman disease is a rare lymphoproliferative disease of unknown cause. In most cases, afflicted patients present with a mediastinal mass although the disease may manifest in numerous other sites, including intracranially and rarely intraspinally. The authors report on the case of a 19-year-old woman who presented with a large paraspinal mass emanating from the T7-8 neural foramen. The morphological and signal characteristics revealed on magnetic resonance imaging were similar to those of nerve sheath tumors. The patient underwent open biopsy sampling of the lesion, and results of a pathological evaluation revealed hyaline-vascular type Castleman disease. She underwent radiotherapy and remains symptom-free with a radiographically stable lesion 1 year later. Although the disease has been reported to mimic a meningioma when encountered in intracranial locations, to the authors' knowledge, this is the first case of the disorder mimicking a nerve sheath tumor. When the diagnosis of Castleman disease is made, good results can be obtained with partial resection and radiotherapy

Surgical treatment of occipitocervical instability

Journal ArticleOBJECTIVE: Instability of the occipitocervical junction can be a challenging surgical problem because of the unique anatomic and biomechanical characteristics of this region. We review the causes of instability and the development of surgical techniques to stabilize the occipitocervical junction. METHODS: Occipitocervical instrumentation has advanced significantly, and modern modular screw-based constructs allow for rigid short-segment fixation of unstable elements while providing the stability needed to achieve successful fusion in nearly 100% of patients. This article reviews the preoperative planning, the variety of instrumentation and surgical strategies, as well as the postoperative care of these patients. RESULTS: Current constructs use occipital plates that are rigidly fixed to the thick midline keel of the occipital bone, polyaxial screws that can be placed in many different trajectories, and rods that are bent to approximate the acute occipitocervical angle. These modular constructs provide a variety of methods to achieve fixation in the atlantoaxial complex, including transarticular screws or C1 lateral mass screws in combination with C2 pars, C2 pedicle, or C2 translaminar trajectories. CONCLUSION: Surgical techniques for occipitocervical instrumentation and fusion are technically challenging and require meticulous preoperative planning and a thorough understanding of the regional anatomy, instrumentation, and constructs. Modern screw-based techniques for occipitocervical fusion have established clinical success and demonstrated biomechanical stability, with fusion rates approaching 100%

Observations of Unsteady Airfoil Flows

http://deepblue.lib.umich.edu/bitstream/2027.42/96610/1/39015087358597.pd

Optimizations of Pt/SiC and W/Si multilayers for the Nuclear Spectroscopic Telescope Array

The Nuclear Spectroscopic Telescope Array, NuSTAR, is a NASA funded Small Explorer Mission, SMEX, scheduled for launch in mid 2011. The spacecraft will fly two co-aligned conical approximation Wolter-I optics with a focal length of 10 meters. The mirrors will be deposited with Pt/SiC and W/Si multilayers to provide a broad band reflectivity from 6 keV up to 78.4 keV. To optimize the mirror coating we use a Figure of Merit procedure developed for gazing incidence optics, which averages the effective area over the energy range, and combines an energy weighting function with an angular weighting function to control the shape of the desired effective area. The NuSTAR multilayers are depth graded with a power-law, d_i = a/(b + i)^c, and we optimize over the total number of bi-layers, N, c, and the maximum bi-layer thickness, d_(max). The result is a 10 mirror group design optimized for a flat even energy response both on and off-axis

Mass and Redshift Dependence of Star Formation in Relaxed Galaxy Clusters

We investigate the star-formation properties of dynamically relaxed galaxy clusters as a function of cluster mass for 308 low-redshift clusters drawn from the Sloan Digital Sky Survey (SDSS) C4 cluster catalog. It is important to establish if cluster star-formation properties have a mass dependence before comparing clusters at different epochs, and here we use cluster velocity dispersion as a measure of cluster mass. We find that the total stellar mass, the number of star-forming galaxies, and total star-formation rate scale linearly with the number of member galaxies, with no residual dependence on cluster velocity dispersion. With the mass-dependence of cluster star-formation rates established, we compare the SDSS clusters with a sample of z = 0.75 clusters from the literature and find that on average the total H-alpha luminosity of the high-redshift clusters is 10 times greater than that of the low-redshift clusters. This can be explained by a decline in the H-alpha luminosities of individual cluster galaxies by a factor of up to 10 since z = 0.75. The magnitude of this evolution is comparable to that of field galaxies over a similar redshift interval, and thus the effect of the cluster environment on the evolution of star-forming galaxies is at most modest. Our results suggest that the physical mechanism driving the evolution of cluster star-formation rates is independent of cluster mass, at least for clusters with velocity dispersion greater than 450 km/s, and operates over a fairly long timescale such that the star-formation rates of individual galaxies decline by an order of magnitude over ~7 billion years. (Abridged)Comment: 15 pages; 13 figures; accepted for publication in the Astrophysical Journa

First Determination of the Weak Charge of the Proton

The Q(weak) experiment has measured the parity-violating asymmetry in (e) over right arrowp elastic scattering at Q(2) = 0.025 (GeV/c)(2), employing 145 mu A of 89% longitudinally polarized electrons on a 34.4 cm long liquid hydrogen target at Jefferson Lab. The results of the experiment\u27s commissioning run, constituting approximately 4% of the data collected in the experiment, are reported here. From these initial results, the measured asymmetry is A(ep) = -279 +/- 35 (stat) +/- 31 (syst) ppb, which is the smallest and most precise asymmetry ever measured in (e) over right arrowp scattering. The small Q(2) of this experiment has made possible the first determination of the weak charge of the proton Q(W)(p) by incorporating earlier parity-violating electron scattering (PVES) data at higher Q(2) to constrain hadronic corrections. The value of Q(W)(p) obtained in this way is Q(W)(p) (PVES) = 0.064 +/- 0.012, which is in good agreement with the standard model prediction of Q(W)(p) (SM) = 0.0710 +/- 0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES + APV analysis reveals the neutron\u27s weak charge to be Q(W)(n) (PVES + APV) = -0.975 +/- 0.010