The literature on the effectiveness of CPD continues to expand, but effectiveness is not a sufficient criterion for implementation. For scarce resources to be devoted to CPD, the relative cost ...effectiveness of different educational interventions must be established, and those offering the most value for money must be implemented. An investment in high quality evaluations would therefore reap health benefits for the public and ease policy makers' decisions about resource allocation.
During the past two decades, research on ceramic scaffolds for bone regeneration has progressed rapidly; however, currently available porous scaffolds remain unsuitable for load-bearing applications. ...The key to success is to apply microstructural design strategies to develop ceramic scaffolds with mechanical properties approaching those of bone. Here we report on the development of a unique microstructurally designed ceramic scaffold, strontium–hardystonite–gahnite (Sr–HT–gahnite), with 85% porosity, 500μm pore size, a competitive compressive strength of 4.1±0.3MPa and a compressive modulus of 170±20MPa. The in vitro biocompatibility of the scaffolds was studied using primary human bone-derived cells. The ability of Sr–HT–gahnite scaffolds to repair critical-sized bone defects was also investigated in a rabbit radius under normal load, with β-tricalcium phosphate/hydroxyapatite scaffolds used in the control group. Studies with primary human osteoblast cultures confirmed the bioactivity of these scaffolds, and regeneration of rabbit radial critical defects demonstrated that this material induces new bone defect bridging, with clear evidence of regeneration of original radial architecture and bone marrow environment.
The abundance profile of the human urinary proteome is known to change as a result of diseases or drug toxicities, particularly of those affecting the kidney and the urogenital tract. A consequence ...of such insults is the ability to identify proteins in urine, which may be useful as quantitative biomarkers. To succeed in discovering them, reproducible urine sample preparation methods and good protein resolution in two‐dimensional electrophoresis (2‐DE) gels for parallel semiquantitative protein measurements are desirable. Here, we describe a protein fractionation strategy enriching proteins of molecular masses (Mr) lower than 30 kDa in a fraction separate from larger proteins. The fraction containing proteins with Mrs higher than 30 kDa was subsequently subjected to immunoaffinity subtraction chromatography removing most of the highly abundant albumin and immunoglobulin G. Following 2‐DE display, superior protein spot resolution was observed. Subsequent high‐throughput mass spectrometry analysis of ca. 1400 distinct spots using matrix‐assisted laser desorption/ionization‐time of flight peptide mass fingerprinting and liquid chromatography‐electrospray ionization tandem mass spectrometry lead to the successful identification of 30% of the proteins. As expected from high levels of post‐translational modifications in most urinary proteins and the presence of proteolytic products, ca. 420 identified spots collapsed into 150 unique protein annotations. Only a third of the proteins identified in this study are described as classical plasma proteins in circulation, which are known to be relatively abundant in urine despite their retention to a large extent in the glomerular blood filtration process. As a proof of principle that our urinary proteome display effort holds promise for biomarker discovery, proteins isolated from the urine of a renal cell carcinoma patient were profiled prior to and after nephrectomy. Particularly, the decrease in abundance of the kininogen 2‐DE gel spot train in urine after surgery was striking.
We investigated the surface texture and chemical compositions of two ~40-μm particles returned from the surface regolith of asteroid Itokawa (RB-DQ04-0062 and RB-DQ04-0091) by the Japan Aerospace ...Exploration Agency’s Hayabusa mission. We identified splash melts, surface blistering, and many small adhering particles. Seven focused ion beam sections were extracted from both Itokawa particles, targeting one splash melt and ten adhering particles to investigate their composition and provenance and the role of micrometeoroid impacts on Itokawa’s surface. Based on the particle’s structure, mineralogy, and interface between the adhering particle and host grain, we identified lithic fragments and particles deposited by impact. These have morphologies and compositions consistent with impact-generated deposits: two have morphologies and compositions that are consistent with impact-generated silica glass, and one was a Ni-free, metallic Fe, and S-rich assemblage that was likely generated by vapor recondensation during a micrometeoroid impact. This study shows that, even though its regolith is young, micrometeoroid impacts have altered the regolith of asteroid Itokawa.
The mechanical properties of 63% Sn-37% Pb and lead-free solders have been measured at high strain rates (500-3000 s-1) using a split Hopkinson pressure bar. The solders were produced by quenching in ...water from the melt, to give the phase structure associated with rapid cooling. Measurements were made at -40 deg C, room temperature and +60 deg C. The Sn-Pb solder was strongly strain rate and temperature dependent, whereas the lead-free solders showed only a weak dependence on these parameters. All of the materials behaved elasto-plastically until a plateau stress of circa 200 MPa. An unexpected, and possibly important, feature of the lead-free solders was the division of the specimens into two groups with different strengths at low temperatures.
Two RDX/HTPB polymer bonded explosives (PBXs), with different explosive particle size, were studied in a Hopkinson bar system at three different temperatures. Three temperatures were chosen, two ...above, and one below, the glass transition temperature of the binder material. The PBX consisted of cyclotrimethylene trinitramine (RDX) crystals in a hydroxyl-terminated-polybutadiene (HTPB) binder. Overall the larger particle sized material was weaker, and exhibited a more distinct yield point than the finer sized material. Both materials showed temperature sensitivity, the effect being greater in the material with the smaller particles.
The typically slow life histories of sharks make them susceptible to overexploitation. However, this characteristic also means that shark populations are more amenable to mark-recapture estimation of ...vital rates and to population viability analysis, compared to many teleost (bony) fishes. We applied this novel approach to inform fisheries management for 2 shark species (Carcharhinus tilstoni and C. sorrah) in northern Australia. We calculated survival estimates based on a current mark-recapture study and age-frequency distributions from historical catch data, and used these along with other estimates of vital rates to construct an individual-based population viability analysis (using Vortex software). We estimated total current mortality (natural and fishing-related) from tagging data using Brownie models (mean ± SE: 0.532 ± 0.097 and 0.487 ± 0.136) and recapture rate (fisheries-related mortality) (0.023 ± 0.005 and 0.008 ± 0.003) for C. tilstoni and C. sorrah, respectively. Based on historical age-at-length and age-frequency data, mean survival across ages after historical overexploitation was similar for both species (~0.43, or ~0.33 as an age frequency-weighted mean). After correcting for capture-related mortality and permanent emigration, Vortex population projections including incrementing simulated harvest suggest that the current rates of harvest of both species result in population trajectories that are approximately stable (20 yr predicted average rate of population change r ≅ 0), but this is complicated by a variable contribution of the slower-reproducing species C. limbatus within the black-tip shark complex (C. limbatus is commonly misidentified as C. tilstoni in the fishery). Vortex projections also clearly indicated that the fishery was overexploited in the past. Using multiple datasets and an individual-based modelling framework to estimate harvest limits for a commercial fishery provides novel insights into management. This is especially pertinent to shark populations given the relative tractability of marking and recovering individuals and the inherent suscepti bility of shark populations to overexploitation.
Applied ecologists routinely use demographic models to predict population trajectories. Survival rates throughout the life cycle, which are required for these models, are often difficult to obtain, ...especially for long‐lived or mobile species. Detailed information for pre‐adult age classes in particular is often lacking. Using a 20‐year dataset from several hundred individuals, we used Markov chain Monte Carlo methods to fit hierarchical models that describe survival rates for both adult and sub‐adult Hawaiian stilts Himantopus mexicanus knudseni, an endangered island endemic. We constructed the complete‐data likelihood and used data augmentation to estimate missing values and incorporate data that were not collected during formal sampling. Survival estimates were lower and more uncertain during the first 2 months of life compared with the remainder of the first year. The probability of first‐year survival averaged 0.55 (95% credibility interval: 0.07–0.90), but varied considerably among cohorts from different years and islands. Probability of adult annual survival differed little between females (0.79; 0.71–0.86) and males (0.80; 0.72–0.87), but increased as birds aged from 1 to 20 years (0.77–0.85). Our analysis confirms that earlier work, despite being based on few data, provided good point estimates for survival rates. Our new analysis, however, provides the first comprehensive assessment of uncertainty in survival rates and detailed information on the nature of variation in first‐year and adult survival. This information will help inform new demographic models and can be used to guide management actions.
PDF
