Publications by authors named "Andrew J Hamer"

With large wildfires becoming more frequent, we must rapidly learn how megafires impact biodiversity to prioritize mitigation and improve policy. A key challenge is to discover how interactions among fire-regime components, drought and land tenure shape wildfire impacts. The globally unprecedented 2019-2020 Australian megafires burnt more than 10 million hectares, prompting major investment in biodiversity monitoring.

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Research into freshwater communities often aims to link patterns of species distribution in ponds with underlying biotic factors. However, errors with species detection (e.g.

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River-floodplain ecosystems play a crucial role in connecting landscape patches through hydrological connectivity, but they are among the most threatened ecosystems. Floodplains provide important habitat for amphibians by connecting aquatic and terrestrial habitats. Modifications to floodplain hydrology can impact amphibian communities, yet few studies have examined amphibian metacommunities in floodplain wetlands.

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Cities can host significant biological diversity. Yet, urbanisation leads to the loss of habitats, species, and functional groups. Understanding how multiple taxa respond to urbanisation globally is essential to promote and conserve biodiversity in cities.

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Background: Patient-specific instrumentation (PSI) was developed to produce more accurate alignment of components and consequently improve clinical outcomes when used in total knee arthroplasty. We compare radiological accuracy and clinical outcomes at a minimum of 5-year follow-up between patients randomized to undergo total knee arthroplasty performed using PSI or traditional cutting block techniques.

Methods: This multicenter, randomized control trial included patients blinded to the technique 1used.

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Background: Osteolysis causes recurrent pain and disability after total hip arthroplasty. We investigated the effect of the human monoclonal antibody denosumab on osteolytic lesion activity in patients undergoing revision total hip arthroplasty surgery to show the biological proof of concept for a non-surgical treatment for the disease.

Methods: We did a phase 2, randomised, double-blind, placebo-controlled, proof of concept superiority trial at Sheffield Teaching Hospitals, Sheffield, UK.

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A fundamental goal of community ecology is to understand species-habitat relationships and how they shape metacommunity structure. Recent advances in occupancy modeling enable habitat relationships to be assessed for both common and rare species within metacommunities using multi-species occupancy models (MSOM). These models account for imperfect species detection and offer considerable advantages over other analytical tools commonly used for community analyses under the elements of metacommunity structure (EMS) framework.

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Background: Data on the outcome of THA in patients under the age of 30 years is sparse. There is a perceived reluctance to offer surgery to young patients on the basis of potential early failure of the implant. The aim of this study was to review clinical and radiological outcomes of THA in patients under the age of 30 years in a high-volume specialist arthroplasty unit.

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Orthopaedic theatre can be noisy. Fifty percent of orthopaedic theatre staff have features of noise-induced hearing loss (NIHL). In this study, decibel (dB) levels were recorded in 17 total knee replacements (TKRs) and 11 total hip replacements (THRs).

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Background: The aim of this study was to review the results of the use of a cemented, standard length, taper-slip femoral component at second stage following an extended trochanteric osteotomy (ETO).

Methods: We reviewed prospectively collected data from the hospital arthroplasty database, identifying and reviewing all patients who had undergone an ETO at first-stage revision for infection, who had subsequently undergone second-stage reimplantation.

Results: Over 17 years, 99 patients underwent 102 2-stage procedures with ETO at first stage, with a mean follow-up of 5.

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Two pervasive and fundamental impacts of urbanization are the loss and fragmentation of natural habitats. From a genetic perspective, these impacts manifest as reduced genetic diversity and ultimately reduced genetic viability. The growling grass frog (Litoria raniformis) is listed as vulnerable to extinction in Australia, and endangered in the state of Victoria.

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Background: This two-year randomized clinical trial was performed to examine whether the geometry of the cemented femoral prosthesis affects the pattern of strain-adaptive bone remodeling in the proximal aspect of the femur after primary total hip arthroplasty.

Methods: One hundred and twenty patients were randomized to receive a Charnley (composite-beam), Exeter (double-tapered), or C-Stem (triple-tapered) prosthesis. The change in proximal femoral bone mineral density over two years was measured by dual x-ray absorptiometry (DXA).

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Urbanization is currently responsible for widespread declines of amphibian populations globally through the loss, isolation, and degradation of habitat. However, it is not clear how urbanization affects amphibian communities at both local (pond) and landscape scales. We assessed the breeding distribution of frogs in ponds along an urban-rural gradient in Greater Melbourne, Australia, and examined community relationships with habitat quality and landscape context.

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Secreted frizzled-related protein-3 (sFRP3) antagonizes ligands that promote new bone formation in adult tissues. We examined whether variation in the FRZB gene that encodes sFRP3 is associated with development of osteolysis or heterotopic ossification (HO) after total hip arthroplasty (THA). Genomic DNA was extracted from 609 subjects (osteolysis group n = 268) at a mean of 11 years following cemented THA for idiopathic osteoarthritis and genotyped for the FRZB Arg200Trp and Arg324Gly polymorphisms.

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Dual energy X-ray absorptiometry (DXA) is a precise tool for measuring bone mineral density (BMD) around total joint prostheses. The Hologic "metal-removal hip" analysis package (Hologic Inc., Waltham, MA) is a Microsoft DOS-based analysis platform that has undergone a change in the operating platform to a Microsoft Windows-based system that has also incorporated changes to DXA image manipulation on-screen.

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The aim of this study was to assess the diagnostic accuracy of radiology department-based hip aspiration for the diagnosis of infection after total hip arthroplasty. Patient selection criteria were devised so that only patients with moderate to high risk of infection were selected for hip aspiration. Seventy-three patients are included in this study, all of whom underwent revision hip surgery after aspiration.

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Pressurization techniques are used to improve the cement/bone interface at hip arthroplasty. Ultra-high-molecular-weight polyethylene (UHMWPE) cement restrictors leave particulate debris at insertion; biodegradable restrictors may therefore be preferable. We compared the migration behavior of 2 such cement restrictors.

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We studied the relationship between polyethylene wear and osteolysis in 230 subjects after cemented Charnley total hip arthroplasty in order to examine the validity of the wear rate threshold concept. Polyethylene wear measured using image analysis (EBRA) software was compared in 115 subjects with osteolysis versus 115 control subjects that were individually matched for age, sex, and follow up period. Subjects with osteolysis had almost twice the mean annual wear rate versus the controls.

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In this trial we studied the effect of pamidronate on periprosthetic bone turnover and pelvic implant migration over 2 years after hybrid total hip arthroplasty (THA). Twenty-two patients received 90 mg of pamidronate and 22 received placebo at randomization 5 days after surgery. Rapid periprosthetic bone loss occurred in the placebo group over the first 6 months and was accompanied by transient increases in biochemical markers of bone turnover.

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The use of Computational Fluid Dynamics (CFD) and in particular Large Eddy Simulation (LES) codes to model fires provides an efficient tool for the prediction of large-scale effects that include plume characteristics, combustion product dispersion, and heat effects to adjacent objects. This paper illustrates the strengths of the Fire Dynamics Simulator (FDS), an LES code developed by the National Institute of Standards and Technology (NIST), through several small and large-scale validation runs and process safety applications. The paper presents two fire experiments--a small room fire and a large (15 m diameter) pool fire.

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The ability of 29 peripheral quantitative computed tomography (pQCT) software analysis modes at defining cortical from trabecular bone at three tibial metaphyseal regions was evaluated using five cadaveric tibiae. The accuracy of pQCT was determined by comparing the bone mineral content (BMC) with the ash weight. The precision of the pQCT scanner was calculated using repeated measurements.

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Unlabelled: Genetic factors may influence implant failure caused by osteolysis after THA. In an association study of 481 subjects after THA, we found that carriage of the TNF-238A allele was associated with an increased incidence of osteolysis versus noncarriage (odds ratio, 1.7) and was independent of other risk factors.

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The aims of this study were to determine whether subjects with aseptic loosening after total hip arthroplasty (THA) have regional differences in periprosthetic bone mineral density (BMD) and systemic biochemical markers of bone turnover compared to subjects with successful implants.Proximal femoral and pelvic BMD were measured by dual energy X-ray absorptiometry and bone turnover markers were assayed in 49 subjects 12.6+/-4.

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