1,222 research outputs found

    An Attack by a Polar Bear on a Juvenile Beluga

    Get PDF
    Cunningham Inlet, Somerset Island, in the Canadian Arctic is frequented each summer by large numbers of beluga (Delphinapterus leucas). They migrate to the head of the inlet, and then invade the mouths of the two streams which drain into it. … On 26 July 1974, a sexually-immature female beluga was discovered stranded on a gravel bar at the head of the inlet. Because it could not be manhandled back to water, and would have died from suffocating and dehydration, the whale was shot. The brown colour, shape of head and length (271 cm) of the animal suggested that it was between three and four years old, while the five to six growth layers present in the teeth indicated an age of 2½-3 years. The stomach was found to contain a few amphipods and some seaweed. The carcass carried deep but well-healed scars on the left dorso-lateral aspect caudal to the dorsal ridge. Their depth, and the fact that they were parallel in three cases, strongly suggested that the animal had been attacked by a large-clawed animal, probably a polar bear (Ursus maritimus). … To our knowledge this paper constitutes only the third documented account of an attack on a beluga by a polar bear in the Canadian Arctic …. [All previously reported attacks, including an attack of captive belugas near Churchill, are also discussed in this article.

    Facilitating children's self-concept: A rationale and evaluative study

    Get PDF
    This study reports on the design and effectiveness of the Exploring Self-Concept program for primary school children using self-concept as the outcome measure. The program aims to provide a procedure that incorporates organisation, elaboration, thinking, and problem-solving strategies and links these to children's multidimensional self-concept. The results of this research support the notion that teachers and guidance counsellors need to establish a nonthreatening framework that allows them to discuss with children a range of relevant issues related to peer pressure, parent relations, self-image, body image, gender bias, media pressure, values and life goals, in a systematic, objective and cooperative manner. Within the paper, notions associated with self-concept maturation, 'crystallisation' of self-concept beliefs, cognitive differentiation and self-concept segmentation are reviewed

    In the dedicated pursuit of dedicated capital: restoring an indigenous investment ethic to British capitalism

    Get PDF
    Tony Blair’s landslide electoral victory on May 1 (New Labour Day?) presents the party in power with a rare, perhaps even unprecedented, opportunity to revitalise and modernise Britain’s ailing and antiquated manufacturing economy.* If it is to do so, it must remain true to its long-standing (indeed, historic) commitment to restore an indigenous investment ethic to British capitalism. In this paper we argue that this in turn requires that the party reject the very neo-liberal orthodoxies which it offered to the electorate as evidence of its competence, moderation and ‘modernisation’, which is has internalised, and which it apparently now views as circumscribing the parameters of the politically and economically possible

    Blindness and Visual Impairment in an Urban West African Population: The Tema Eye Survey

    Get PDF
    To determine the prevalence, etiologies, and risk factors of blindness and visual impairment among persons age 40 years and older residing in an urban West African location

    Defining Ecological Drought for the Twenty-First Century

    Get PDF
    THE RISING RISK OF DROUGHT. Droughts of the twenty-first century are characterized by hotter temperatures, longer duration, and greater spatial extent, and are increasingly exacerbated by human demands for water. This situation increases the vulnerability of ecosystems to drought, including a rise in drought-driven tree mortality globally (Allen et al. 2015) and anticipated ecosystem transformations from one state to another—for example, forest to a shrubland (Jiang et al. 2013). When a drought drives changes within ecosystems, there can be a ripple effect through human communities that depend on those ecosystems for critical goods and services (Millar and Stephenson 2015). For example, the “Millennium Drought” (2002–10) in Australia caused unanticipated losses to key services provided by hydrological ecosystems in the Murray–Darling basin—including air quality regulation, waste treatment, erosion prevention, and recreation. The costs of these losses exceeded AUD $800 million, as resources were spent to replace these services and adapt to new drought-impacted ecosystems (Banerjee et al. 2013). Despite the high costs to both nature and people, current drought research, management, and policy perspectives often fail to evaluate how drought affects ecosystems and the “natural capital” they provide to human communities. Integrating these human and natural dimensions of drought is an essential step toward addressing the rising risk of drought in the twenty-first century

    An element through the looking glass: Exploring the Au-C, Au-H and Au-O energy landscape

    Get PDF
    Gold, the archetypal “noble metal”, used to be considered of little interest in catalysis. It is now clear that this was a misconception, and a multitude of gold-catalysed transformations has been reported. However, one consequence of the long-held view of gold as inert metal is that its organometallic chemistry contains many “unknowns”, and catalytic cycles devised to explain gold's reactivity draw largely on analogies with other transition metals. How realistic are such mechanistic assumptions? In the last few years a number of key compound classes have been discovered that can provide some answers. This Perspective attempts to summarise these developments, with particular emphasis on recently discovered gold(III) complexes with bonds to hydrogen, oxygen, alkenes and CO ligands

    Prevalence of Glaucoma in an Urban West African Population: The Tema Eye Survey

    Get PDF
    Multiple studies have found an increased prevalence, younger age at onset, and more severe course of glaucoma in people of African descent, but these findings are based on studies conducted outside Africa

    A rapidly-reversible absorptive and emissive vapochromic Pt(II) pincer-based chemical sensor

    Get PDF
    Selective, robust and cost-effective chemical sensors for detecting small volatile-organic compounds (VOCs) have widespread applications in industry, healthcare and environmental monitoring. Here we design a Pt(II) pincer-type material with selective absorptive and emissive responses to methanol and water. The yellow anhydrous form converts reversibly on a subsecond timescale to a red hydrate in the presence of parts-per-thousand levels of atmospheric water vapour. Exposure to methanol induces a similarly-rapid and reversible colour change to a blue methanol solvate. Stable smart coatings on glass demonstrate robust switching over 104 cycles, and flexible microporous polymer membranes incorporating microcrystals of the complex show identical vapochromic behaviour. The rapid vapochromic response can be rationalised from the crystal structure, and in combination with quantum-chemical modelling, we provide a complete microscopic picture of the switching mechanism. We discuss how this multiscale design approach can be used to obtain new compounds with tailored VOC selectivity and spectral responses
    corecore