409 research outputs found

    Phrenology report of Miss Sarah Benson Mather by A.S. Hamilton, Van Diemen's Land, 1833

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    Sketch of the character of Miss Sarah Benson Mather by A.S. Hamilton, who practised phrenology. M19/2

    Constraining a model of punctuated river incision for Quaternary strath terrace formation

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    In the small fraction of Earth's surface with the highest erosion rates such as the Alps and Himalayas quantifying rates of incision, rock uplift and inferring climatic controls on the landscape can be relatively straightforward once the ages of river terraces cut in bedrock (strath terraces) are constrained. However, in many mid to lower relief settings that are more typical of mountain belts worldwide, periods of net river incision and riverbed lowering are relatively short (punctuated), interrupted by long periods of sediment aggradation or stasis. We define a conceptual model of punctuated river incision and strath terrace formation for the calculation of incision and rock uplift rates, and recommend strategies for geochronological sampling and interpretation. An approach using OSL dating of terrace gravels allows us to constrain a detailed ~150 kyr history of punctuated river incision and strath terrace formation spanning two stratigraphic landform levels in the High Atlas Mountains (NW Africa). Extensive preservation and exposure of strath-top gravels, within a post-orogenic setting unaffected by eustatic influences, enables the derivation of rates of base-level fall, integrated over periods of strath-top aggradation and incision, that are consistent with independently constrained regional rock uplift rates. Combining a punctuated river incision model with our well-constrained terrace formation history allows us to demonstrate how assumptions concerning Quaternary river incision and aggradation can lead to the problematic Sadler Effect, an apparent dependence of incision rates on measured time interval. Subsequently, we demonstrate that an approach to reinterpreting previously published data using the punctuated incision model, even when combined with limited terrace age data, results in more consistent conclusions about rates of river incision, rock uplift and base-level lowering across the mountain belt. Our recommendations for sampling strategies to constrain rock uplift rates require samples to be taken just above the strath surface, and in addition towards the top of the deposit for river incision rates. In a setting with punctuated river incision and strath terrace formation, both rock uplift and incision rates require burial dates, as exclusive use of abandonment ages will not yield constraints on accurate rates of rock uplift or incision. Furthermore, we find that only with multiple along-stream locations and multiple burial dates in each terrace deposit, could a reliable climatic signal be extracted: this signal would not have shown up in terrace abandonment ages such as those derived from cosmogenic exposure dates. The demonstrated effects of assumptions about strath terrace formation, and the recommended approaches for sampling and interpretation, have implications for those attempting to constrain palaeoclimatic, tectonic, and geomorphic histories from strath terrace records in regions exhibiting punctuated river incision

    Circulating leukocyte telomere length is highly heritable among families of Arab descent

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    Background Telomere length, an indicator of ageing and longevity, has been correlated with several biomarkers of cardiometabolic disease in both Arab children and adults. It is not known, however, whether or not telomere length is a highly conserved inheritable trait in this homogeneous cohort, where age-related diseases are highly prevalent. As such, the aim of this study was to address the inheritability of telomere length in Saudi families and the impact of cardiometabolic disease biomarkers on telomere length. Methods A total of 119 randomly selected Saudi families (123 adults and 131 children) were included in this cross-sectional study. Anthropometrics were obtained and fasting blood samples were taken for routine analyses of fasting glucose and lipid profile. Leukocyte telomere length was determined using quantitative real time PCR. Results Telomere length was highly heritable as assessed by a parent-offspring regression [h2 = 0.64 (p = 0.0006)]. Telomere length was modestly associated with BMI (R2 0.07; p-value 0.0087), total cholesterol (R2 0.08; p-value 0.0033), and LDL-cholesterol (R2 0.15; p-value 3 x 10-5) after adjustments for gender, age and age within generation. Conclusion The high heritability of telomere length in Arab families, and the associations of telomere length with various cardiometabolic parameters suggest heritable genetic fetal and/or epigenetic influences on the early predisposition of Arab children to age-related diseases and accelerated ageing

    Silvopastoral systems as a tool for territorial sustainability and biodiversity

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    Rural and livestock population evolution in the inner north of Portugal has demonstrated a great regression with consequences for environment and nature conservation. In this context, and taking into account that pastoral activity has shaped the natural areas of mountain territories since its beginning and that territories are currently part of Natura 2000 network, rethinking the importance of such activity has become vital. The constraints affecting daily tasks performed by shepherds and livestock breeders as well as the installed social segregation are a strong limitation. However, current research developed in the context of nature conservation has demonstrated the importance of the landscape mosaic promoted by grazing in the preservation of priority habitats. In this way, it is urgent to assess the issue of shepherds and livestock breeders’ image in terms of their roles, relationships and concerns, as well as to assess pastoralism socioeconomics in regard to self-consumption, market and rural self-sufficiency. In this perspective, this work presents an analysis of the adaptation of grazing to current times, perceiving its limitations and success potential.This work is supported by European Structural and Investment Funds, FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 006971 (UID/SOC/04011)], and national funds, through FCT, Portuguese Foundation for Science and Technology under project UID/SOC/04011/2013.info:eu-repo/semantics/publishedVersio

    Biophysical suitability, economic pressure and land-cover change: a global probabilistic approach and insights for REDD+

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    There has been a concerted effort by the international scientific community to understand the multiple causes and patterns of land-cover change to support sustainable land management. Here, we examined biophysical suitability, and a novel integrated index of “Economic Pressure on Land” (EPL) to explain land cover in the year 2000, and estimated the likelihood of future land-cover change through 2050, including protected area effectiveness. Biophysical suitability and EPL explained almost half of the global pattern of land cover (R 2 = 0.45), increasing to almost two-thirds in areas where a long-term equilibrium is likely to have been reached (e.g. R 2 = 0.64 in Europe). We identify a high likelihood of future land-cover change in vast areas with relatively lower current and past deforestation (e.g. the Congo Basin). Further, we simulated emissions arising from a “business as usual” and two reducing emissions from deforestation and forest degradation (REDD) scenarios by incorporating data on biomass carbon. As our model incorporates all biome types, it highlights a crucial aspect of the ongoing REDD + debate: if restricted to forests, “cross-biome leakage” would severely reduce REDD + effectiveness for climate change mitigation. If forests were protected from deforestation yet without measures to tackle the drivers of land-cover change, REDD + would only reduce 30 % of total emissions from land-cover change. Fifty-five percent of emissions reductions from forests would be compensated by increased emissions in other biomes. These results suggest that, although REDD + remains a very promising mitigation tool, implementation of complementary measures to reduce land demand is necessary to prevent this leakage

    Biodiversity scientists must fight the creeping rise of extinction denial

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    Eforts by conservation scientists to draw public attention to the biodiversity crisis are increasingly met with denialist rhetoric. We summarize some of the methods used by denialists to undermine scientifc evidence on biodiversity loss, and outline pathways forward for the scientifc community to counter misinformation

    Forests as Commons – Changing Traditions and Governance in Europe

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    Commons are complex institutions and exist across the world in a wide range of situations regarding locally developed governance and management systems of many different natural resources. For many people commons remain associated with Hardin’s theory concerning the “Tragedy of the Commons” (1968), in which he assumed that local users of a natural resource are unable to formulate governance and management structures concerning their own choices that took into account the long-term sustainability of the resource itself. As a result, Hardin articulated that the tragedy was that the resource would inevitably become degraded in such situations and that the solution was private or public ownership. However, across Europe many forests have for a very long period of time successfully been managed as commons, just as they have in many other parts of the world. This chapter has three main aims: It will provide an introduction to the various types of commons before going on to link the issue of commons to the traditional forest landscapes of Europe, and it will look at how the role of forests and forest landscapes has changed and how it may change further in the future

    Evaluation of exercise on individuals with dementia and their carers: a randomised controlled trial

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    Background Almost all of the 820,000 people in the UK with dementia will experience Behavioural and Psychological Symptoms of Dementia (BPSD). However, research has traditionally focused on treating cognitive symptoms, thus neglecting core clinical symptoms that often have a more profound impact on living with dementia. Recent evidence (Kales et al, 2007; Ballard et al, 2009) indicates that the popular approach to managing BPSD - prescription of anti-psychotic medication - can increase mortality and the risk of stroke in people with dementia as well as impair quality of life and accelerate cognitive decline. Consequently, there is a need to evaluate the impact that non-pharmacological interventions have on BPSD; we believe physical exercise is a particularly promising approach. Methods/Design We will carry out a pragmatic, randomised, single-blind controlled trial to evaluate the effectiveness of exercise (planned walking) on the behavioural and psychological symptoms of individuals with dementia. We aim to recruit 146 people with dementia and their carers to be randomized into two groups; one will be trained in a structured, tailored walking programme, while the other will continue with treatment as usual. The primary outcome (BPSD) will be assessed with the Neuropsychiatric Inventory (NPI) along with relevant secondary outcomes at baseline, 6 and 12 weeks. Discussion Designing this study has been challenging both ethically and methodologically. In particular to design an intervention that is simple, measurable, safe, non-invasive and enjoyable has been testing and has required a lot of thought. Throughout the design, we have attempted to balance methodological rigour with study feasibility. We will discuss the challenges that were faced and overcome in this paper

    A comparison of responses to raised extracellular potassium and endothelium-derived hyperpolarizing factor (EDHF) in rat pressurised mesenteric arteries

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    The present study examined the hypothesis that potassium ions act as an endothelium-derived hyperpolarizing factor (EDHF) released in response to ACh in small mesenteric arteries displaying myogenic tone. Small mesenteric arteries isolated from rats were set up in a pressure myograph at either 60 or 90 mmHg. After developing myogenic tone, responses to raising extracellular potassium were compared to those obtained with ACh (in the presence of nitric oxide synthase and cyclo- oxygenase inhibitors). The effects of barium and ouabain, or capsaicin, on responses to raised extracellular potassium or ACh were also determined. The effects of raised extracellular potassium levels and ACh on membrane potential, were measured using sharp microelectrodes in pressurised arteries. Rat small mesenteric arteries developed myogenic tone when pressurised. On the background of vascular tone set by a physiological stimulus (i.e pressure), ACh fully dilated the small arteries in a concentration-dependent manner. This response was relatively insensitive to the combination of barium and ouabain, and insensitive to capsaicin. Raising extracellular potassium produced a more inconsistent and modest vasodilator response in pressurised small mesenteric arteries. Responses to raising extracellular potassium were sensitive to capsaicin, and the combination of barium and ouabain. ACh caused a substantial hyperpolarisation in pressurized arteries, while raising extracellular potassium did not. These data indicate that K+ is not the EDHF released in response to ACh in myogenically active rat mesenteric small arteries. Since the hyperpolarization produced by ACh was sensitive to carbenoxolone, gap junctions are the likely mediator of EDH responses under physiological conditions
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