Metal pollution as a potential threat to shell strength and survival in marine bivalves

Marine bivalve molluscs, such as scallops, mussels and oysters, are crucial components of coastal ecosystems, providing a range of ecosystem services, including a quarter of the world’s seafood. Unfortunately, due to human activity, coastal marine areas often suffer from metal contamination. We establish that increased levels of metal pollution (zinc, copper and lead) in sediments near the Isle of Man, resulting from historical mining, strongly correlate with significant weakening of shell strength in king scallops, Pecten maximus. This weakness increases mortality during fishing and leaves individuals more exposed to predation. Comparative structural analysis revealed that shells from the contaminated area were thinner and exhibited a pronounced mineralisation disruption parallel to the shell surface within the foliated region of both the top and bottom valves. Our data suggest that these disruptions caused reduced fracture strength and hence increased mortality, even at subcritical contamination levels with respect to current international standards. This hitherto unreported effect is important since such non-apical responses rarely feed into environmental quality assessments, with significant implications for population survival. Hence, our findings highlight the impact of metal pollution on shell mineralisation in bivalves, and urge a reappraisal of currently accepted critical contamination levels

Crystal structure and magnetic modulation in β−Ce2O2FeSe2

We report a combination of X-ray and neutron diffraction studies, Mossbauer spectroscopy and muon spin relaxation (muSR) measurements to probe the structure and magnetic properties of the semiconducting beta-Ce2O2FeSe2 oxychalcogenide. We report a new structural description in space group Pna21 which is consistent with diffraction data and second harmonic generation measurements and reveal an order-disorder transition on one Fe site at TOD ~ 330 K. Susceptibility measurements, Mossbauer and muSR reveal antiferromagnetic ordering below TN = 86 K and more complex short range order above this temperature. 12 K neutron diffraction data reveal a modulated magnetic structure with q = 0.444 bN*

After Mazibuko: exploring the responses of communities excluded from South Africa’s water experiment

Despite a constitutional right to water, challenges remain for access to sufficient water in South Africa. This article considers the degree to which current legal provisions perpetuate approaches, which are antithetical to genuinely eco-socio-sustainable water access. Water in South Africa has largely been re-cast as a commodity, exposed to market rules, proving problematic for many and giving rise to various responses, including litigation. In the seminal case of Mazibuko the Constitutional Court failed to provide robust protection to the right to water, providing impetus for the formation of “commons” strategies for water allocation. Indeed “commoning” is beginning to represent not only an emerging conceptual strand in urban resource allocation, but also a dynamic, contemporary, eco-sensitive, socio-cultural phenomenon, driving innovative, interactive and inclusive forms of planning and social engagement. Against the backdrop of unequal water access, commoning offers glimpses of an empowering and enfranchising subaltern paradigm

A problem-structuring model for analyzing transportation–environment relationships

This is the post-print version of the final paper published in European Journal of Operational Research. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2009 Elsevier B.V.This study discusses a decision support framework that guides policy makers in their strategic transportation related decisions by using multi-methodology. For this purpose, a methodology for analyzing the effects of transportation policies on environment, society, economy, and energy is proposed. In the proposed methodology, a three-stage problem structuring model is developed. Initially, experts’ opinions are structured by using a cognitive map to determine the relationships between transportation and environmental concepts. Then a structural equation model (SEM) is constructed, based on the cognitive map, to quantify the relations among external transportation and environmental factors. Finally the results of the SEM model are used to evaluate the consequences of possible policies via scenario analysis. In this paper a pilot study that covers only one module of the whole framework, namely transportation–environment interaction module, is conducted to present the applicability and usefulness of the methodology. This pilot study also reveals the impacts of transportation policies on the environment. To achieve a sustainable transportation system, the extent of the relationships between transportation and the environment must be considered. The World Development Indicators developed by the World Bank are used for this purpose

National trends and local delivery in old age mental health services: towards an evidence base: a mixed-methodology study of the balance of care approach, community mental health teams and specialist mental health outreach to care homes

Background The rising number of older people with mental health problems makes the effective use of mental health resources imperative. Little is known about the clinical effectiveness and/or cost-effectiveness of different service models. Aims The programme aimed to (1) refine and apply an existing planning tool [‘balance of care’ (BoC)] to this client group; (2) identify whether, how and at what cost the mix of institutional and community services could be improved; (3) enable decision-makers to apply the BoC framework independently; (4) identify variation in the structure, organisation and processes of community mental health teams for older people (CMHTsOP); (5) examine whether or not different community mental health teams (CMHTs) models are associated with different costs/outcomes; (6) identify variation in mental health outreach services for older care home residents; (7) scope the evidence on the association between different outreach models and resident outcomes; and (8) disseminate the research findings to multiple stakeholder groups. Methods The programme employed a mixed-methods approach including three systematic literature reviews; a BoC study, which used a systematic framework for choosing between alternative patterns of support by identifying people whose needs could be met in more than one setting and comparing their costs/outcomes; a national survey of CMHTs’ organisation, structure and processes; a multiple case study of CMHTs exhibiting different levels of integration encompassing staff interviews, an observational study of user outcomes and a staff survey; national surveys of CMHTs’ outreach activities and care homes. A planned randomised trial of depression management in care homes was removed at the review stage by the National Institute for Health Research (NIHR) prior to funding award. Results BoC: Past studies exhibited several methodological limitations, and just two related to older people with mental health problems. The current study suggested that if enhanced community services were available, a substantial proportion of care home and inpatient admissions could be diverted, although only the latter would release significant monies. CMHTsOP: 60% of teams were considered multidisciplinary. Most were colocated, had a single point of access (SPA) and standardised assessment documentation. Evidence of the impact of particular CMHT features was limited. Although staff spoke positively about integration, no evidence was found that more integrated teams produced better user outcomes. Working in high-integration teams was associated with poor job outcomes, but other factors negated the statistical significance of this. Care home outreach: Typical services in the literature undertook some combination of screening (less common), assessment, medication review, behaviour management and training, and evidence suggested intervention can benefit depressed residents. Care home staff were perceived to lack necessary skills, but relatively few CMHTs provided formal training. Limitations Limitations include a necessary reliance on observational rather than experimental methods, which were not feasible given the nature of the services explored. Conclusions BoC: Shifting care towards the community would require the growth of support services; clarification of extra care housing’s (ECH) role; timely responses to people at risk of psychiatric admission; and improved hospital discharge planning. However, the promotion of care at home will not necessarily reduce public expenditure. CMHTsOP: Although practitioners favoured integration, its goals need clarification. Occupational therapists (OTs) and social workers faced difficulties identifying optimal roles, and support workers’ career structures needed delineating. Care home outreach: Further CMHT input to build care home staff skills and screen for depression may be beneficial. Priority areas for further study include the costs and benefits for older people of age inclusive mental healt

Management of abnormal uterine bleeding by northern, rural and isolated primary care physicians: PART I – How are we doing?

BACKGROUND: Canadian hysterectomy rates have declined in recent years. However, hysterectomy rates for discretionary indications, principally abnormal uterine bleeding (AUB), remain high in some regions. In northern Ontario, hysterectomy rates for women aged 34–45 are almost triple the rates in southern, urban areas. Primary care physicians (family doctors) usually manage AUB initially in these northern areas where a severe shortage of gynecologists exists. METHODS: We surveyed 194 family physicians in northern Ontario with a case scenario of a pre-menopausal woman with heavy vaginal bleeding to characterize management and to gain physicians' perspectives on the factors that affect it. RESULTS: To investigate her heavy vaginal bleeding, only 17% of physicians recommended a pelvic examination for the woman in our case scenario. Most physicians advocated a course of medical therapy before referral to a gynecologist, for whom the average waiting time was seven weeks. However, most physicians recommended referral after only one failed trial of medical treatment. Physicians felt that major deterrents to medical treatments were patient desires for immediate relief and/or permanent solutions, poor patient compliance and the high cost of medication. Only 25% of respondents indicated that they would perform an endometrial biopsy prior to referral. CONCLUSIONS: Family physicians would benefit from further education on appropriate investigations for AUB, primarily training in pelvic examination and endometrial biopsy techniques, as well as appropriate treatment algorithms. Further research into patient perspectives on treatment options is needed

Linear Field Dependence of the Normal-State In-Plane Magnetoresistance of Sr2RuO4

The transverse and longitudinal in-plane magnetoresistances in the normal state of superconducting Sr2RuO4 single crystals have been measured. At low temperatures, both of them were found to be positive with a linear magnetic-field dependence above a threshold field, a result not expected from electronic band theory. We argue that such behavior is a manifestation of a novel coherent state characterized by a spin pseudo gap in the quasi-particle excitation spectrum in Sr2RuO4.Comment: 4 pages + 5 figure

Attributing scientific and technical progress: the case of holography

Holography, the three-dimensional imaging technology, was portrayed widely as a paradigm of progress during its decade of explosive expansion 1964–73, and during its subsequent consolidation for commercial and artistic uses up to the mid 1980s. An unusually seductive and prolific subject, holography successively spawned scientific insights, putative applications and new constituencies of practitioners and consumers. Waves of forecasts, associated with different sponsors and user communities, cast holography as a field on the verge of success—but with the dimensions of success repeatedly refashioned. This retargeting of the subject represented a degree of cynical marketeering, but was underpinned by implicit confidence in philosophical positivism and faith in technological progressivism. Each of its communities defined success in terms of expansion, and anticipated continual progressive increase. This paper discusses the contrasting definitions of progress in holography, and how they were fashioned in changing contexts. Focusing equally on reputed ‘failures’ of some aspects of the subject, it explores the varied attributes by which success and failure were linked with progress by different technical communities. This important case illuminates the peculiar post-World War II environment that melded the military, commercial and popular engagement with scientific and technological subjects, and the competing criteria by which they assessed the products of science

The Fine-Scale Structure of the neutral Interstellar Medium in nearby Galaxies

We present an analysis of the properties of HI holes detected in 20 galaxies that are part of "The HI Nearby Galaxy Survey" (THINGS). We detected more than 1000 holes in total in the sampled galaxies. Where they can be measured, their sizes range from about 100 pc (our resolution limit) to about 2 kpc, their expansion velocities range from 4 to 36 km/s, and their ages are estimated to range between 3 and 150 Myr. The holes are found throughout the disks of the galaxies, out to the edge of the HI; 23% of the holes fall outside R25. We find that shear limits the age of holes in spirals (shear is less important in dwarf galaxies) which explains why HI holes in dwarfs are rounder, on average than in spirals. Shear, which is particularly strong in the inner part of spiral galaxies, also explains why we find that holes outside R25 are larger and older. We derive the scale height of the HI disk as a function of galactocentric radius and find that the disk flares up in all galaxies. We proceed to derive the surface and volume porosity (Q2D and Q3D) and find that this correlates with the type of the host galaxy: later Hubble types tend to be more porous. The size distribution of the holes in our sample follows a power law with a slope of a ~ -2.9. Assuming that the holes are the result of massive star formation, we derive values for the supernova rate (SNR) and star formation rate (SFR) which scales with the SFR derived based on other tracers. If we extrapolate the observed number of holes to include those that fall below our resolution limit, down to holes created by a single supernova, we find that our results are compatible with the hypothesis that HI holes result from star formation.Comment: 142 pages, 55 figures, accepted for publication in the Astronomical Journa

The Rise and Fall of Passive Disk Galaxies: Morphological Evolution Along the Red Sequence Revealed by COSMOS

The increasing abundance of passive "red-sequence" galaxies since z=1-2 is mirrored by a coincident rise in the number of galaxies with spheroidal morphologies. In this paper, however, we show that in detail the correspondence between galaxy morphology and color is not perfect, providing insight into the physical origin of this evolution. Using the COSMOS survey, we study a significant population of red sequence galaxies with disk-like morphologies. These passive disks typically have Sa-Sb morphological types with large bulges, but they are not confined to dense environments. They represent nearly one-half of all red-sequence galaxies and dominate at lower masses (log Mstar < 10) where they are increasingly disk-dominated. As a function of time, the abundance of passive disks with log Mstar < 11 increases, but not as fast as red-sequence spheroidals in the same mass range. At higher mass, the passive disk population has declined since z~1, likely because they transform into spheroidals. We estimate that as much as 60% of galaxies transitioning onto the red sequence evolve through a passive disk phase. The origin of passive disks therefore has broad implications for understanding how star formation shuts down. Because passive disks tend to be more bulge-dominated than their star-forming counterparts, a simple fading of blue disks does not fully explain their origin. We explore several more sophisticated explanations, including environmental effects, internal stabilization, and disk regrowth during gas-rich mergers. While previous work has sought to explain color and morphological transformations with a single process, these observations open the way to new insight by highlighting the fact that galaxy evolution may actually proceed through several separate stages.Comment: 16 pages, Accepted version to appear in Ap