85 research outputs found

    Seasonal and interannual variability of feeding in Antarctic benthos

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    The seasonal and interannual variability of feeding in 15 species of benthic marine suspension feeder was studied over 8 yr at Ryder Bay, Antarctica. Feeding was strongly seasonal in bryozoans, gorgonians, polychaetes, and dendrochirote holothurians. The winter non-feeding period was longest in the holothurians and shortest in bryozoans. Bryozoans started feeding in late winter at very low chlorophyll concentrations, often when surface fast-ice was still present. In hydroids and actinians, feeding tentacles were deployed continuously throughout the year, though hydroid feeding intensity declined slightly in late winter. Water column phytoplankton biomass was strongly seasonal with marked interannual variability in the timing and intensity of the bloom, driven principally by ice dynamics. Correlation across years between the start of feeding and the development of the bloom was poor, and in seasons when a dense spring bloom of benthic filamentous microalgae developed, the start of feeding in many benthic species was delayed. This study indicates that feeding in benthic marine suspension feeders in Antarctica is influenced by factors additional to the seasonal availability of food in the water column

    Blogs: a tool for the physical sciences

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    Teaching and learning are never static processes, and in the sciences we are increasingly mindful of the constructivist learning paradigm. We accept that science education needs to change from teacher-centred teaching to student-centred learning, from passive learning to active learning and towards a blended learning situation that relies heavily on research-led teaching. Lately we have been asking how the newest developments on the Web can be used to achieve these goals. Direct publishing to the web and content aggregation tools such as blogs, wikis and RSS (Really Simple Syndication) are having a powerful effect on publishing. These are excellent tools for promoting ongoing dialogue. Because of their ability to provide thoughtful dialogue within a short time frame, they provide a platform within science education for discussion on current theories and recent discoveries and development. One excellent example of a blog being used in this way is Real Climate (http://www.realclimate.org/) with its ongoing discussion of global dimming and other issues of climate change. This paper aims to explore the various forms of direct publishing and content aggregation tools currently available to educators and the range of educational activities to which they are being applied. However, our search for examples of how blogs are being used in science research, science education and research into science education has not been very rewarding

    Blogging in science and science education

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    Teaching and learning are never static processes, and in the sciences we are increasingly mindful of the constructivist learning paradigm. We accept that science education needs to change from teachercentred teaching to student-centred learning, from passive learning to active learning and towards a blended learning situation that relies heavily on research-led teaching. Lately we have been asking how the newest developments on the Web can be used to achieve these goals. Direct publishing to the web and content aggregation tools such as blogs, wikis and RSS (Really Simple Syndication) are having a powerful effect on publishing. These are excellent tools for promoting ongoing dialogue. Because of their ability to provide thoughtful dialogue within a short time frame, they provide a platform within science education for discussion on current theories and recent discoveries and development. One excellent example of a blog being used in this way is Real Climate (http://www.realclimate.org/) with its ongoing discussion of global dimming and other issues of climate change. This paper aims to explore the various forms of direct publishing and content aggregation tools currently available to educators and the range of educational activities to which they are being applied. However, our search for examples of how blogs are being used in science research, science education and research into science education has not been very rewarding

    Increasing accuracy: a new design and algorithm for automatically measuring weights, travel direction and radio frequency identification (RFID) of penguins.

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    A fully automated weighbridge using a new algorithm and mechanics integrated with a Radio Frequency Identification System is described. It is currently in use collecting data on Macaroni penguins (Eudyptes chrysolophus) at Bird Island, South Georgia. The technology allows researchers to collect very large, highly accurate datasets of both penguin weight and direction of their travel into or out of a breeding colony, providing important contributory information to help understand penguin breeding success, reproductive output and availability of prey. Reliable discrimination between single and multiple penguin crossings is demonstrated. Passive radio frequency tags implanted into penguins allow researchers to match weight and trip direction to individual birds. Low unit and operation costs, low maintenance needs, simple operator requirements and accurate time stamping of every record are all important features of this type of weighbridge, as is its proven ability to operate 24 hours a day throughout a breeding season, regardless of temperature or weather conditions. Users are able to define required levels of accuracy by adjusting filters and raw data are automatically recorded and stored allowing for a range of processing options. This paper presents the underlying principles, design specification and system description, provides evidence of the weighbridge’s accurate performance and demonstrates how its design is a significant improvement on existing system

    Polar biodiversity data: from a national marine platform to a global data portal

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    Global access to accurate biodiversity data is a prerequisite to our progress in understanding biodiversity dynamics in ecosystems and any changes that are occurring. Despite recent major advancements in sharing data on the world’s species, one of the remaining challenges relates to the mechanics of guiding data systematically from its provenance to end users. It can take considerable effort to orchestrate a successful sampling campaign, manage samples obtained in often extreme, remote conditions and to secure preservation of, and access to, the acquired data. Here, we briefly describe biodiversity data flow from a polar ship to a national data repository and onward to a global data portal. This paper highlights a few crucial points in this process, which aims to provide information systematically into the mosaic of our polar species biodiversity knowledge. This flexible workflow can be modified for other data types and adopted by other data repositories

    Metabolic risk factors and the incidence and progression of radiographic hand osteoarthritis: a population-based cohort study.

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    OBJECTIVE: To determine whether selected metabolic factors are associated with greater amounts of radiographic hand osteoarthritis (OA) incidence and progression. METHODS: The study identified 706 adults, aged 50-69 years, with hand pain and hand radiographs at baseline, from two population-based cohorts. Metabolic factors (body mass index, hypertension, dyslipidaemia, and diabetes) were ascertained at baseline by direct measurement and medical records. Analyses were undertaken following multiple imputation of missing data, and in complete cases (sensitivity analyses). Multivariable regression models estimated associations between metabolic factors and two measures of radiographic change at 7 years for all participants, individuals free of baseline radiographic OA, and in baseline hand OA subsets. Estimates were adjusted for baseline values and other covariates. RESULTS: The most consistent and strong associations observed were between the presence of diabetes and the amount of radiographic progression in individuals with nodal OA [adjusted mean differences in Kellgren-Lawrence summed score of 4.50 (-0.26, 9.25)], generalized OA [3.27 (-2.89, 9.42)], and erosive OA [3.05 (-13.56, 19.67)]. The remaining associations were generally weak or inconsistent, although numbers were limited for analyses of incident radiographic OA and erosive OA in particular. CONCLUSION: Overall metabolic risk factors were not independently or collectively associated with greater amounts of radiographic hand OA incidence or progression over 7 years, but diabetes was associated with radiographic progression in nodal, and possibly generalized and erosive OA. Diabetes has previously been associated with prevalent but not incident hand OA. Further investigation in hand OA subsets using objective measures accounting for disease duration and control is warranted

    Consultant-led UK paediatric palliative care services: Professional configuration, services, funding

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    Objectives: To systematically gather information on the professional team members, services provided, funding sources and population served for all consultant-led specialised paediatric palliative care (SPPC) teams in the UK. Methods: Two-part online survey. Results: Survey 1: All 17 medical leads from hospital-based or hospice-based SPPC teams responded to the survey (100% response rate). Only six services met the NICE guidance for minimum SPPC team. All services reported providing symptom management, specialist nursing care, end-of-life planning and care, and supporting discharges and transfers to home or hospice for the child's final days-hours. Most services also provided care coordination (n=14), bereavement support (n=13), clinical psychology (n=10) and social work-welfare support (n=9). Thirteen had one or more posts partially or fully funded by a charity. Survey 2: Nine finance leads provided detailed resource/funding information, finding a range of statutory and charity funding sources. Only one of the National Health Service (NHS)-based services fully funded by the NHS. Conclusions: One-third of services met the minimum criteria of professional team as defined by NICE. Most services relied on charity funding to fund part or all of one professional post and only one NHS-based service received all its funding directly from the NHS

    The Knee Clinical Assessment Study – CAS(K). A prospective study of knee pain and knee osteoarthritis in the general population

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    BACKGROUND: Knee pain affects an estimated 25% of the adult population aged 50 years and over. Osteoarthritis is the most common diagnosis made in older adults consulting with knee pain in primary care. However, the relationship between this diagnosis and both the current disease-based definition of osteoarthritis and the regional pain syndrome of knee pain and disability is unclear. Expert consensus, based on current evidence, views the disease and the syndrome as distinct entities but the clinical usefulness of these two approaches to classifying knee pain in older adults has not been established. We plan to conduct a prospective, population-based, observational cohort study to investigate the relative merits of disease-based and regional pain syndrome-based approaches to classification and prognosis of knee pain in older adults. METHODS: All patients aged 50 years and over registered with three general practices in North Staffordshire will be invited to take part in a two-stage postal survey. Respondents to this survey phase who indicate that they have experienced knee pain within the previous 12 months will be invited to attend a research clinic for a detailed assessment. This will consist of clinical interview, physical examination, digital photography, plain x-rays, anthropometric measurement and a brief self-complete questionnaire. All consenting clinic attenders will be followed up by (i) general practice medical record review, (ii) repeat postal questionnaire at 18-months

    The Knee Clinical Assessment Study – CAS(K). A prospective study of knee pain and knee osteoarthritis in the general population: baseline recruitment and retention at 18 months

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    BACKGROUND: Selective non-participation at baseline (due to non-response and non-consent) and loss to follow-up are important concerns for longitudinal observational research. We investigated these matters in the context of baseline recruitment and retention at 18 months of participants for a prospective observational cohort study of knee pain and knee osteoarthritis in the general population. METHODS: Participants were recruited to the Knee Clinical Assessment Study – CAS(K) – by a multi-stage process involving response to two postal questionnaires, consent to further contact and medical record review (optional), and attendance at a research clinic. Follow-up at 18-months was by postal questionnaire. The characteristics of responders/consenters were described for each stage in the recruitment process to identify patterns of selective non-participation and loss to follow-up. The external validity of findings from the clinic attenders was tested by comparing the distribution of WOMAC scores and the association between physical function and obesity with the same parameters measured directly in the target population as whole. RESULTS: 3106 adults aged 50 years and over reporting knee pain in the previous 12 months were identified from the first baseline questionnaire. Of these, 819 consented to further contact, responded to the second questionnaire, and attended the research clinics. 776 were successfully followed up at 18 months. There was evidence of selective non-participation during recruitment (aged 80 years and over, lower socioeconomic group, currently in employment, experiencing anxiety or depression, brief episode of knee pain within the previous year). This did not cause significant bias in either the distribution of WOMAC scores or the association between physical function and obesity. CONCLUSION: Despite recruiting a minority of the target population to the research clinics and some evidence of selective non-participation, this appears not to have resulted in significant bias of cross-sectional estimates. The main effect of non-participation in the current cohort is likely to be a loss of precision in stratum-specific estimates e.g. in those aged 80 years and over. The subgroup of individuals who attended the research clinics and who make up the CAS(K) cohort can be used to accurately estimate parameters in the reference population as a whole. The potential for selection bias, however, remains an important consideration in each subsequent analysis

    A New Avenue to Relaxor-like Ferroelectric Behaviour Found by Probing the Structure and Dynamics of [NH3NH2]Mg(HCO2)3

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    The field of relaxor ferroelectrics has long been dominated by ceramic oxide materials exhibiting large polarisations with temperature and frequency dependence. Intriguingly, the dense metal-organic framework (MOF) [NH3NH2]Mg(HCO2)3 was reported as one of the first coordination frameworks to exhibit relaxor-like properties. This work clarifies the origin of these relaxor-like properties through re-examining its unusual phase transition using neutron single crystal diffraction, along with solid-state NMR and quasielastic neutron scattering studies. This reveals that the phase transition is caused by the partial re-orientation of NH3NH2 within the pores of the framework, from lying in the planes of the channel at lower temperatures to along the channel direction above the transition temperature. The transition occurs via a dynamic process such that the NH3NH2 cations can slowly interconvert between parallel and perpendicular orientations, with an estimated activation energy of 60 kJ mol-1. Furthermore these studies are consistent with proton hopping between the hydrazinium cations oriented along the channel direction via a proton site intermediate. This suggests the ferroelectric properties of [NH3NH2]Mg(HCO2)3 likely driven by a hydrogen bonding mechanism. The relaxor behaviour is proposed to be the result of polar regions, which likely fluctuate due to increased cation dynamics at high temperature. The combination of cation reorientation and proton hopping fully describes this material’s relaxor-like behaviour, suggesting a route to future design of non-oxide-based relaxor ferroelectrics
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