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The paper summarises briefly the current status of the major land using activities in the hills and uplands. The dominant land use roles of agriculture and forestry arc explained, as are other uses of recreation, water provision and wild life and landscape conservation. Land use competition in the hills and uplands is seen as the end result of conflicting policy objectives pursued by the major rural resource planning agencies over the past 50 years. The role of these agencies is analysed, as is their ability to meet their objectives in competition with each other. Finally, an attempt is made to establish a quantitative framework within which the interests of the various groups are recognised and priorities in land use can be determined.
The strong self-damped Lyman α absorption systems present in the spectra of high redshift QSOs represent a unique population of absorber which has recently been associated with the precursors of current disk galaxies. In a low resolution survey for what we have come to call “Lyman α disk systems” performed at Lick Observatory (Wolfe, et al. 1986, Ap. J. Suppl. 61, 249) approximately 18 systems with confirmed damped Lyman α profiles and rest frame equivalent widths greater than 5 Å were detected in a sample of 68 high redshift QSOs (Smith, Cohen and Bradley 1986, Ap. J. 310, 583). Subsequent higher resolution study has shown these systems to have the following properties (Turnshek, et al. 1988, Ap. J., in press):
2.Low-mixed ionization state. Typically the low ionization states dominate the high ionization states (e.g. CII ≫ CIV). Some enrichment has occurred, −2≲[X/H]⊙ ≲0.
3.Gas density, n ≲ 1 cm−3.
4.The gas shows two components, a quiescent (disk) component, σν ≲ 10 km s−1, and a turbulent (halo) component, σν ≲ 20 km s−1. Some systems show only the low velocity dispersion component.
5.At least one system intervening toward a radio QSO (Pks 0458-020) shows 21-cm absorption. The system shows multiple cloud structure with σν ≈ 6 km s−1, Ts ≈ 100 K, and structure extended over several kpc on the sky.
6.There is evidence that these systems may be self gravitating with scale height of the order of 300 pc.
7.These systems represent a unique population of absorber (distinct from the ‘Lyman a forest’ and heavy element systems) covering approximately 20% of the sky to z ≈ 3 and accounting for all of the baryonic matter at that redshift.
Conjugated polymers have been proposed as promising materials for scaffolds in tissue engineering applications. However, the restricted processability and biodegradability of conjugated polymers limit their use for biomedical applications. Here we synthesized a block-co-polymer of aniline tetramer and PCL (AT–PCL), and processed it into fibrous non-woven scaffolds by electrospinning. We showed that fibronectin (Fn) adhesion was dependent on the AT–PCL oxidative state, with a reduced Fn unfolding length on doped membranes. Furthermore, we demonstrated the cytocompatibility and potential of these membranes to support the growth and osteogenic differentiation of MC3T3-E1 cells over 21 days.
We report on our analysis of a 300 ks observation of the Vela pulsar with the Rossi X-Ray Timing Explorer (RXTE). The double-peaked, pulsed emission at 2 - 30 keV, which we had previously detected during a 93 ks observation, is confirmed with much improved statistics. There is now clear evidence, both in the spectrum and the light curve, that the emission in the RXTE band is a blend of two separate components. The spectrum of the harder component connects smoothly with the OSSE, COMPTEL and EGRET spectrum and the peaks in the light curve are in phase coincidence with those of the high-energy light curve. The spectrum of the softer component is consistent with an extrapolation to the pulsed optical flux, and the second RXTE pulse is in phase coincidence with the second optical peak. In addition, we see a peak in the 2-8 keV RXTE pulse profile at the radio phase.
There has been increasing emphasis on performing ‘same-day’ or ‘out-patient’ thyroidectomy to reduce associated costs. However, acceptance has been limited by the risk of potentially life-threatening post-operative bleeding. This study aimed to review current rates of post-operative bleeding in a metropolitan teaching hospital and identify risk factors.
Medical records of patients undergoing thyroidectomy between January 2007 and March 2012 were reviewed retrospectively. Pre-operative, operative and pathological data, and post-operative complication data, were examined.
The study comprised 205 thyroidectomy cases. Mean age was 51.6 years (standard deviation = 14.74), with 80 per cent females. Unilateral thyroidectomy was performed in 81 cases (39.5 per cent) and total thyroidectomy was performed in 74 cases (36.1 per cent; 5.3 per cent with concomitant lymph node dissection). Nine patients (4.4 per cent) suffered post-operative bleeding, of which six required re-operation. Analysis showed that post-operative systolic blood pressure of 180 mmHg or greater was associated with post-operative bleeding (p = 0.003, chi-square test).
Rates of significant post-operative bleeding are consistent with recent literature. Post-operative hypertension, diabetes and high post-operative drain output were identified as independent risk factors on multivariate analysis; when identified, these may be caveats to same-day discharge of thyroidectomy patients.
Calculations based on Poisson-Boltzmann theory are used to investigate the equilibrium properties of an electrolyte containing TcO4− and SO42− ions near the surface of amorphous silica. The calculations show that the concentration of TcO4− is greater than SO42− at distances less than 1 nm from the surface due to the negative charge density caused by deprotonation of the amorphous silica silanol groups. At lower pH, the surface becomes protonated and the magnitude of this effect is reduced. These results have implications for the potential use of oxyanion-SAMMS for the environmental remediation of water contaminated with 99Tc.
Biodegradable Normal Human Osteoblast (NHOst) cells were inoculated into the polymer scaffolds of poly(β-hydroxybutyrate) (PHB) obtained from a specially developed strain of Azotobacter vinelandii. Cell adhesion is essential to promote growth on scaffolds for tissue engineering. Thus, in this research we focused on the adhesion of osteoblast cells to PHB scaffolds produced by solution casting and electrospinning. Cell viability was also investigated up to 168 hrs. Water contact angle on the PHB scaffolds was determined prior to the cells inoculation. The contact angle is usually related to the ability of different cell strains to adhere to a given material. The as cast film exhibited a contact angle α=72° whereas for the electrospun membrane α=102°, thus in theory cell adhesion would be greater for the cast film. Biological testing was carried out on plates of 24 wells; cell viability was determined by Trypan Blue, cell morphology by optical microscopy, and cell nuclei integrity by staining with Acridine orange. Parallel studies were carried out on control (empty) wells. Microscopy observations 168 hrs after cell inoculation showed larger quantities of osteoblast cells in the wells containing PHB scaffolds and the cell nuclei were still active. Moreover, it was found that the cells grew inside the PHB scaffolds and the cell viability was slightly greater for the electrospun scaffold. Interestingly, the time to remove the cells from the scaffolds (film and membranes) was increasing function of the cell culture time, therefore suggesting that PHB promotes adhesion of Normal Human Osteoblast cells to its surface.
Single-crystalline rutile with porous and complex structure can be produced by tuning reaction conditions so as to maintain low titania solubility. X-ray diffraction, high-resolution transmission electron microscopy, and cryogenic transmission electron microscopy results are consistent with the hypothesis that oriented aggregation of anatase crystals precedes rutile nucleation and growth from anatase nanocrystal interfaces. The product rutile retains morphological and microstructure features consistent with an aggregation-based phase transformation because coarsening, or monomer-by-monomer growth, is suppressed under these conditions of low titania solubility.
Porous coatings at the surface of living cells have application in human cell transplantation by controlling the transport of biomolecules to and from the cells. Sol-gel-derived mesoporous silica materials are good candidates for such coatings, owing to their biocompatibility, facile solution-based synthesis conditions, and thin film formation. Diffusion and transport across the coating correlates to long-range microstructural properties, including pore size distribution, porosity, and pore morphology. Here, we investigated collagen-fibril matrices with known biocompatibility to serve as templating systems for directed silica deposition. Type 1 collagen oligomers derived from porcine skin are extensively characterized such that we can predict and customize the final collagen-fibril matrix with respect to fibril density, interfibril branching and viscoelasticity. We show that these matrices template and direct the deposition of mesoporous silica at the level of individual collagen fibrils. We varied the fibril density, silicic acid concentration, and time of exposure to silicifying solution and characterized the resulting hybrid materials by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and rheology. Microstructural properties of the collagen-fibril template are preserved in the silica surface of hybrid materials. Results for three different collagen fibril densities, corresponding to shear storage moduli of 200 Pa, 1000 Pa, and 1600 Pa, indicate that increased fibril density increases the absolute amount of templated silica when all other silica synthesis conditions are kept constant. Additionally, mechanical properties of the hybrid material are dominated by the presence of the silica coating rather than the starting collagen matrix stiffness.
Mechanical properties and new morphological data on synthetic sodium hydrogen urate monohydrate are reported and interpreted. Crystals formed in supersaturated aqueous solutions were identified by powder x-ray diffraction. Intact grains and separate needles were examined by several microscopy techniques, some reported here for the first time. The dominant morphology was spherulite-type, comprising tapered, branched blades (needles) radiating out of a common core. The pointed blade tips were truncated by (011) planes, corresponding to hydrogen-bonded planes. Branching was at about a 5° angle or its multiples, suggesting it accommodated by dislocation arrays at the low angle boundaries, as is often seen in twinning. Vicker’s micro-hardness, extrapolated to zero porosity, was 0.90 GPa, which is greater than the hardness measured by nano-indentation. Present results are anticipated to be useful in interpreting the mechanical characteristics of the material crystallized in vivo and its action concerning gout, and affording inferences on the role of the milieu on morphologies, fragmentation, and hardness.
Since their introduction more than forty years ago, antenatal glucocorticoids have become a cornerstone in the management of preterm birth and have been responsible for substantial reductions in neonatal mortality and morbidity. Clinical trials conducted over the past decade have shown that these benefits may be increased further through administration of repeat doses of antenatal glucocorticoids in women at ongoing risk of preterm and in those undergoing elective cesarean at term. At the same time, a growing body of experimental animal evidence and observational data in humans has linked fetal overexposure to maternal glucocorticoids with increased risk of cardiovascular, metabolic and other disorders in later life. Despite these concerns, and somewhat surprisingly, there has been little evidence to date from randomized trials of longer-term harm from clinical doses of synthetic glucocorticoids. However, with wider clinical application of antenatal glucocorticoid therapy there has been greater need to consider the potential for later adverse effects. This paper reviews current evidence for the short- and long-term health effects of antenatal glucocorticoids and discusses the apparent discrepancy between data from randomized clinical trials and other studies.
A written survey administered to 3,500 Florida cattle producers in 2006 documented tropical soda apple as the most common pasture weed across the state of Florida. Over 80% of the survey respondents reported tropical soda apple on their ranches, and over 65% declared the plant to be a major problem for their cattle operation. On ranches that reported tropical soda apple infestations, the level of pastures infested with this weed ranged from a low of 4% in north Florida to a high of 12% in central Florida. The cattle producers' most common strategies to tropical soda apple were herbicide application and mowing. These strategies were used by 32% of respondents in north Florida, 75% in central Florida, and 76% in south Florida. On a statewide basis, 20% of cattle producers used herbicides alone, 7% used mowing alone, and 20% used both methods. Some cattle producers reduced the cattle stocking rate as a consequence of tropical soda apple infestations. This negative impact was reported by only 2% of cattle producers in north Florida, 6% in central Florida, and 7% in south Florida. With the use of the economic input/output model IMPLAN, tropical soda apple control costs resulted in economic losses throughout Florida of $15 million annually in 2006 to cattle producers and their supporting business sectors.
Aragonite can grow from calcium carbonate solutions as the favored phase, at ambient conditions, in the presence of 1:1 volume % water:ethanol. Its form is single and branched needles, with pseudohexagonal symmetry. Morphological evidence demonstrates that all precipitated aragonite is twinned. The recently popularized hypothesis of nonclassical growth by nanocrystal self assembly cannot describe the aragonite crystal form. Rather, its formation is effectively described as spherulitic growth, i.e. by classical crystal growth theory.
Alcohol consumption during pregnancy remains common in many countries. Exposure to even low amounts of alcohol (i.e. ethanol) in pregnancy can lead to the heterogeneous fetal alcohol spectrum disorders (FASD), while heavy alcohol consumption can result in the fetal alcohol syndrome (FAS). FAS is characterized by cerebral dysfunction, growth restriction and craniofacial malformations. However, the effects of lower doses of alcohol during pregnancy, such as those that lead to FASD, are less well understood. In this article, we discuss the findings of recent studies performed in our laboratories on the effects of fetal alcohol exposure using sheep, in which we investigated the effects of late gestational alcohol exposure on the developing brain, arteries, kidneys, heart and lungs. Our studies indicate that alcohol exposure in late gestation can (1) affect cerebral white matter development and increase the risk of hemorrhage in the fetal brain, (2) cause left ventricular hypertrophy with evidence of altered cardiomyocyte maturation, (3) lead to a decrease in nephron number in the kidney, (4) cause altered arterial wall stiffness and endothelial and smooth muscle function and (5) result in altered surfactant protein mRNA expression, surfactant phospholipid composition and pro-inflammatory cytokine mRNA expression in the lung. These findings suggest that fetal alcohol exposure in late gestation can affect multiple organs, potentially increasing the risk of disease and organ dysfunction in later life.
The loss of bone mass and consequently bone strength in persons aged forty and beyond is a continuing problem to the orthopaedic community. This progressive loss has been documented by various means such as radiographs, autopsy materials, CAT scans, and single or dual photon absorptiometrv. Orthopaedic problems arising from osteoporosis include fractures of the lumbar spine, distal radius and the femoral neck. Likewise, this age group represents the fraction of the population that will require prosthetic replacement of a joint. Unfortunately, little information is available concerning the mechanical properties of osteoporotic bones and its interaction with prosthetic devices.
A Monte Carlo procedure has been used to study the ordering of both two and three dimensional (2d and 3d) Potts Hamiltonians, further to the work of Anderson et al. For the 3d lattice, the short time growth rate is found to be much slower than previously reported, though the simulated microstructure is in agreement with the earlier studies. We propose a new stochastic model that gives good agreement with the simulations.
To measure the sputtered ions during implantation a specially designed UHV-target chamber with a SIMS apparatus was set up. Quantitative analysis are possible with an Auger spectrometer. Disturbances in the stoichiometry in InP are measured during implantation of Sn. The enrichment of the doped surface of InP with the lighter component phoshorus will be discussed in consideration of preferential sputtering and recoil effects during implantation. Measured depth profiles of Sn in InP will be compared with calculated distributions on condition that sputtering takes place. The sputtering yield of InP bombarded by 120 keV Sn+ is 17±5.