Seasonal variability in silicate weathering signatures recorded by Li isotopes in cave drip-waters

Silicate weathering is a critical process in Earth’s carbon cycle, but the fundamental controls on weathering are poorly understood and its response to future climate change is uncertain. In particular, the potential for changes in seasonality or extreme weather events to control silicate weathering rates or mechanisms has been little studied. Here, we use lithium (Li) isotope measurements in bimonthly sampled drip-waters from two caves in the Yorkshire Dales (U.K.) to assess the response of silicate weathering processes to changes in temperature and hydrology over seasonal timescales. While the caves are contained in limestone bedrock, the drip-water Li isotope signal predominantly reflects silicate weathering of the overlying soils that are dominated by glacial till

Stable isotope analysis of carnivores from the Turkana Basin, Kenya: evidence for temporally-mixed fossil assemblages

Stable isotope palaeoecology of fossil mammals is a key research tool for understanding the environmental context of hominin evolution in the Plio-Pleistocene of Africa. Well studied mammal groups include bovids, suids, equids, proboscideans and primates, but to date there has been no in-depth study of modern and fossil carnivores. Here we produce an Africa-wide oxygen and carbon enamel isotope dataset for modern carnivores and compare it with fossil carnivore data sampled from the Plio-Pleistocene Omo Group of the Turkana Basin, Kenya. Comparison of modern carnivore carbon isotopes with satellite images of land cover indicates that carnivore δ13C is related to the proportion of woody cover in the local environment. Modern carnivore oxygen isotopes are strongly influenced by the δ18O of meteoric water, through drinking from standing water and through prey body fluids. Carbon isotope data from fossil carnivores shows close agreement with palaeovegetation reconstructions from δ13C of palaeosol carbonates from the same geological Members, and a similar long-term trend in δ13C values through time (4 Ma to 1 Ma), reflecting a gradual increase in the proportion of C4 grasses in the Turkana Basin. This increase in the δ13C of large carnivores is consistent with the evidence from other mammalian groups for an increase in the proportion of grazers compared to browsers and mixed feeders during this time interval. Two distinct trends within oxygen versus carbon isotope space indicates that the fossil carnivores lived during two distinct climatic regimes – one in which palaeo-lake Turkana was freshwater, and one in which the lake resembled its modern-day hyperalkaline state. These two climatic states most likely represent the end-members of precessionally-driven rainfall extremes over the Ethiopian Highlands. This indicates that each studied faunal assemblage from the Omo Group is a time- and climate-averaged palimpsest; this has significant implications for the interpretation of environmental signals and community palaeoecology derived from Turkana Basin fossil mammals, including early hominins

Fossil Carder Bee's nest from the Hominin locality of Taung, South Africa

The Buxton-Norlim Limeworks southwest of Taung, South Africa, is renowned for the discovery of the first Australopithecus africanus fossil, the ‘Taung Child’. The hominin was recovered from a distinctive pink calcrete that contains an abundance of invertebrate ichnofauna belonging to the Coprinisphaera ichnofacies. Here we describe the first fossil bee’s nest, attributed to the ichnogenus Celliforma, from the Plio-Pleistocene of Africa. Petrographic examination of a cell lining revealed the preservation of an intricate organic matrix lined with the calcitic casts of numerous plant trichomes–a nesting behaviour unique to the modern-day carder bees (Anthidiini). The presence of Celliforma considered alongside several other recorded ichnofossils can be indicative of a dry, savannah environment, in agreement with recent work on the palaeoenvironment of Plio-Pleistocene southern Africa. Moreover, the occurrence of ground-nesting bees provides further evidence that the pink calcrete deposits are of pedogenic origin, rather than speleogenic origin as has previously been assumed. This study demonstrates the potential value of insect trace fossils as palaeoenvironmental indicators

Developing a sense of place toolkit: Identifying destination uniqueness

It has long been recognised that the tangible and intangible characteristics that make a location distinctive and memorable, contribute significantly to destination image. How this destination feel is communicated, has largely been the domain of place branding and destination marketing, which have the potential to miss stakeholder voices. Recently though, practitioners are starting to carefully consider ‘sense of place’; that is an emotional attachment to place, which is defined more carefully in the literature review of this article, and which corresponds with long-running academic discussions. This paper attempts to identify some of these and bridge the gap between academic theory on sense of place and practice. In the UK, many rural areas are now seeking to operationalise sense of place through toolkit documents that might inform landscape interpretation and destination branding. A scenario echoed internationally, where local distinctiveness features in both rural and urban planning. However, sense of place in a tourism context, and more specifically the development of these toolkits, has received limited academic attention. Hence, this paper presents the case of Morecambe Bay, and the development of a dedicated sense of place toolkit. The subsequent case emerges from a collaboration between academics and practitioners and draws on participant observation, semi-structured interviews and document analysis. Specifically, the paper outlines a series of workshop activities developed with destination stakeholders and identifies how these inform subsequent toolkit design. It offers a critical analysis of the benefits and potential pitfalls of employing this approach. This case is of value to academics and destination stakeholders interested in identifying and communicating the uniqueness and emotional tone of the destination. Key lessons and recommendations are identified for those engaging in similar toolkit development initiatives

Surgical preferences of patients at risk of hip fractures: hemiarthroplasty versus total hip arthroplasty

BACKGROUND: The optimal treatment of displaced femoral neck fractures in patients over 60 years is controversial. While much research has focused on the impact of total hip arthroplasty (THA) and hemiarthroplasty (HA) on surgical outcomes, little is known about patient preferences for either alternative. The purpose of this study was to elicit surgical preferences of patients at risk of sustaining hip fracture using a novel decision board. METHODS: We developed a decision board for the surgical management of displaced femoral neck fractures presenting risks and outcomes of HA and THA. The decision board was presented to 81 elderly patients at risk for developing femoral neck fractures identified from an osteoporosis clinic. The participants were faced with the scenario of sustaining a displaced femoral neck fracture and were asked to state their treatment option preference and rationale for operative procedure. RESULTS: Eighty-five percent (85%) of participants were between the age of 60 and 80 years; 89% were female; 88% were Caucasian; and 49% had some post-secondary education. Ninety-three percent (93%; 95% confidence interval [CI], 87-99%) of participants chose THA as their preferred operative choice. Participants identified several factors important to their decision, including the perception of greater walking distance (63%), less residual pain (29%), less reoperative risk (28%) and lower mortality risk (20%) with THA. Participants who preferred HA (7%; 95% CI, 1-13%) did so for perceived less invasiveness (50%), lower dislocation risk (33%), lower infection risk (33%), and shorter operative time (17%). CONCLUSION: The overwhelming majority of patients preferred THA to HA for the treatment of a displaced femoral neck fracture when confronted with risks and outcomes of both procedures on a decision board

Newly diagnosed exudative age-related macular degeneration treated with pegaptanib sodium monotherapy in US community-based practices: medical chart review study

<p>Abstract</p> <p>Background</p> <p>Studies have shown that early detection and treatment of neovascular age-related macular degeneration (NV-AMD) can delay vision loss and blindness. The objective of this study was to evaluate the efficacy/safety of intravitreal pegaptanib sodium monotherapy in treatment-naïve subjects with newly diagnosed NV-AMD and to gain insight into characteristics of lesions treated in community-based practices.</p> <p>Methods</p> <p>From seven private US practices, charts were retrospectively reviewed on 73 subjects with previously untreated subfoveal choroidal NV-AMD treated with their first dose of pegaptanib monotherapy on/after 4/1/2005 through 6/5/2006, receiving ≥4 treatments at 6-week intervals over 21 weeks. Primary endpoint: mean visual acuity (VA) change from baseline to month 6.</p> <p>Results</p> <p>75% of lesions were occult, and 82% were subfoveal. From baseline to month 6, mean VA change was -0.68 lines; 58% and 16% gained ≥0 and ≥3 lines of VA, and 70% were responders (<3 lines lost). In 35 subjects with early disease, 80% were responders with a mean gain of 0.46 lines.</p> <p>Conclusion</p> <p>Pegaptanib is effective in real-world patients with treatment-naïve NV-AMD in uncontrolled community-based retina practices.</p

Quaternary development of resilient reefs on the subsiding kimberley continental margin, Northwest Australia

The Kimberley region in remote northwest Australia has poorly known reef systems of two types; coastal fringing reefs and atoll-like shelf-edge reefs. As a major geomorphic feature (from 12ºS to 18ºS) situated along a subsiding continental margin, the shelf edge reefs are in a tropical realm with warm temperatures, relatively low salinity, clear low nutrient waters lacking sediment input, and Indo-West Pacific corals of moderate diversity. Seismic architecture of the Rowley Shoals reveals that differential pre-Holocene subsidence and relative elevation of the pre-Holocene substrate have controlled lagoon sediment infill and reef morphology, forming an evolutionary series reflecting differential accommodation in three otherwise similar reef systems.The Holocene core described for North Scott Reef confirms previous seismic interpretations, and provides a rare ocean-facing reef record. It demonstrates that the Indo-Pacific reef growth phase (RG111) developed during moderate rates of sea level rise of 10 mm/year from 11 to about 7-6.5 ka BP until sea level stabilization, filling the available 27 m of pre-Holocene accommodation. Despite the medium to high hydrodynamic energy imposed by the 4m tides, swell waves and cyclones the reef-building communities represent relatively low-wave energy settings due to their southeast facing and protection afforded by the proximity of the South Reef platform. This study demonstrates the resilience of reefs on the subsiding margin whilst linking Holocene reef morphology to the relative amount of pre-Holocene subsidence

Evaluating model outputs using integrated global speleothem records of climate change since the last glacial

Although quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data–model comparisons. Here, we illustrate this using 456 globally distributed speleothem δ18O records from an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled atmospheric circulation model. We show that the SISAL records reproduce the first-order spatial patterns of isotopic variability in the modern day, strongly supporting the application of this dataset for evaluating model-derived isotope variability into the past. However, the discontinuous nature of many speleothem records complicates the process of procuring large numbers of records if data–model comparisons are made using the traditional approach of comparing anomalies between a control period and a given palaeoclimate experiment. To circumvent this issue, we illustrate techniques through which the absolute isotope values during any time period could be used for model evaluation. Specifically, we show that speleothem isotope records allow an assessment of a model's ability to simulate spatial isotopic trends. Our analyses provide a protocol for using speleothem isotope data for model evaluation, including screening the observations to take into account the impact of speleothem mineralogy on δ18O values, the optimum period for the modern observational baseline and the selection of an appropriate time window for creating means of the isotope data for palaeo-time-slices