6,329 research outputs found

    Evaluating Multiple Arthropod Taxa as Indicators of Invertebrate Diversity in Old Fields

    Get PDF
    Biodiversity, often quantified by species richness, is commonly used to evaluate and monitor the health of ecosystems and as a tool for conservation planning. The use of one or more focal taxa as surrogates or indicators of larger taxonomic diversity can greatly expedite the process of biodiversity measurement. This is especially true when studying diverse and abundant invertebrate fauna. Before indicator taxa are employed, however, research into their suitability as indicators of greater taxonomic diversity in an area is needed. We sampled invertebrate diversity in old fields in southern Michigan using pitfall trapping and morphospecies designations after identification to order or family. Correlation analysis was used to assess species richness relationships between focal arthropod taxa and general invertebrate diversity. Relationships were assessed at two fine spatial scales: within sampling patches, and locally across four sampling patches. Cumulative richness of all assessed taxa increased proportionately with cumulative invertebrate richness as sampling intensity increased within patches. At the among-patch scale, we tentatively identified Hemiptera and Coleoptera as effective indicator taxa of greater invertebrate richness. Although Hymenoptera, Araneae and Diptera exhibited high species richness, their total richness within patches was not associated with overall invertebrate richness among patches. Increased sampling throughout the active season and across a greater number of habitat patches should be conducted before adopting Hemiptera and Coleoptera as definitive indicators of general invertebrate richness in the Great Lakes region. Multiple sampling techniques, in addition to pitfall trapping, should also be added to overcome capture biases associated with each technique

    Too much of a good thing? The role of detailed UAV imagery in characterising large-scale badland drainage characteristics in South-eastern Spain

    Get PDF
    Some arid and semi-arid areas experience high erosion rates as a consequence of their geological and climatic conditions. This can lead to the development of badland environments characterized by very high drainage densities and the occurrence of a range of distinctive landforms indicative of fluvial dissection. These occur along a spectrum of scales and vary from small-scale arroyos or ramblas to large-scale rills and gullies. Drainage networks comprising the larger landforms can be easily identified using traditional remote-sensing methods, such as satellite or aerial imagery, and are therefore amenable to morphometric analyses. The smaller landforms however are not so easily detected. As a result, studies to date have been largely restricted to their direct field observation which is problematic due to their inherent inaccessibility, often on steep, unstable slopes. However, with the advent and popularization of unmanned aerial vehicles (UAVs), also known as drones, those landforms and geomorphological characteristics, which were once invisible to remotely-sensed aerial data can be incorporated into more detailed research. By using one of the most extensively studied badland locations in Europe – the Tabernas Desert in South-Eastern Spain – this article describes the characterization of a large-scale drainage basin (294 m2) using high definition orthophotography and digital elevation model collected from an unmanned rotorcraft and processed using structure from motion software. Results provide an extremely detailed three-dimensional (3D) reconstruction of the study site, and solve one of the inherent issues working with such large scales, namely the significant difference between 2D and 3D measurements. The article concludes by comparing the results obtained with the UAV with those obtained using existing remotely-sensed imagery and by exploring the challenges experienced when working with bespoke high-resolution aerial imagery, such as when too much detail becomes an issue, and the role of this increasing resolution of observation in geomorphological and hydrological analysis

    Identifying promising approaches and initiatives to reducing alcohol related harm

    Get PDF
    This study aimed to identify promising approaches that could be included in multi-component programmes (MCPs) to reduce alcohol related harm at local level in the UK. MCPs involve the identification of alcohol related problems at the local level and implementation of a programme of co-ordinated projects to tackle a problem. They are based on an integrative design where singular interventions run in combination with each other and/or are sequenced together over time; the identification, coordination and mobilisation of local agencies, stakeholders and community are key elements (Thom and Bayley, 2007). This study was underpinned by the recognition that the voices of practitioners are often marginalised in the debates about ‘what works’ and it set out to include their views. So whilst acknowledging the importance of the international research literature, care was taken not to privilege it over other ‘softer’ sources e.g. knowledge and experience of practitioners

    The Genetics of Amyotrophic Lateral Sclerosis: Current Insights

    Get PDF
    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that results in loss of the upper and lower motor neurons from motor cortex, brainstem and spinal cord. Whilst the majority of cases are sporadic, around 10% show familial inheritance. ALS is usually inherited in an autosomal dominant manner, though autosomal recessive and X-linked inheritance do occur. To date, 24 of the genes at 26 loci have been identified; these include loci linked to ALS as well as to FTD-ALS, where family pedigrees contain individuals with frontotemporal dementia with/without ALS. The most commonly established genetic causes of FALS to date are the presence of a hexanucleotide repeat expansion in the C9ORF72 gene (39.3% FALS) and mutation of SOD1, TARDBP and FUS, with frequencies of 12-23.5%, 5% and 4.1% respectively. However, with the increasing use of next generation sequencing of small family pedigrees, this has led to an increasing number of genes associated with ALS. This review provides a comprehensive review on the genetics of ALS and an update of the pathogenic mechanisms associated with these genes. Commonly implicated pathways have been established, including RNA processing, the protein degradation pathways of autophagy and ubiquitin-proteasome-system as well as protein trafficking and cytoskeletal function. Elucidating the role genetics plays in both FALS and SALS is essential for understanding the subsequent cellular dysregulation that leads to motor neuron loss, in order to develop future effective therapeutic strategies

    Thermodynamic and dynamic anomalies for a three dimensional isotropic core-softened potential

    Get PDF
    Using molecular dynamics simulations and integral equations (Rogers-Young, Percus-Yevick and hypernetted chain closures) we investigate the thermodynamic of particles interacting with continuous core-softened intermolecular potential. Dynamic properties are also analyzed by the simulations. We show that, for a chosen shape of the potential, the density, at constant pressure, has a maximum for a certain temperature. The line of temperatures of maximum density (TMD) was determined in the pressure-temperature phase diagram. Similarly the diffusion constant at a constant temperature, DD, has a maximum at a density ρmax\rho_{max} and a minimum at a density ρmin<ρmax\rho_{min}<\rho_{max}. In the pressure-temperature phase-diagram the line of extrema in diffusivity is outside of TMD line. Although in this interparticle potential lacks directionality, this is the same behavior observed in SPC/E water.Comment: 16 page

    An item response theory analysis of self-report measures of adult attachment.

    Get PDF

    Performance of AAOmega: the AAT multi-purpose fibre-fed spectrograph

    Full text link
    AAOmega is the new spectrograph for the 2dF fibre-positioning system on the Anglo-Australian Telescope. It is a bench-mounted, double-beamed design, using volume phase holographic (VPH) gratings and articulating cameras. It is fed by 392 fibres from either of the two 2dF field plates, or by the 512 fibre SPIRAL integral field unit (IFU) at Cassegrain focus. Wavelength coverage is 370 to 950nm and spectral resolution 1,000-8,000 in multi-Object mode, or 1,500-10,000 in IFU mode. Multi-object mode was commissioned in January 2006 and the IFU system will be commissioned in June 2006. The spectrograph is located off the telescope in a thermally isolated room and the 2dF fibres have been replaced by new 38m broadband fibres. Despite the increased fibre length, we have achieved a large increase in throughput by use of VPH gratings, more efficient coatings and new detectors - amounting to a factor of at least 2 in the red. The number of spectral resolution elements and the maximum resolution are both more than doubled, and the stability is an order of magnitude better. The spectrograph comprises: an f/3.15 Schmidt collimator, incorporating a dichroic beam-splitter; interchangeable VPH gratings; and articulating red and blue f/1.3 Schmidt cameras. Pupil size is 190mm, determined by the competing demands of cost, obstruction losses, and maximum resolution. A full suite of VPH gratings has been provided to cover resolutions 1,000 to 7,500, and up to 10,000 at particular wavelengths.Comment: 13 pages, 4 figures; presented at SPIE, Astronomical Telescopes and Instrumentation, 24 - 31 May 2006, Orlando, Florida US

    The Role of Cognitive Factors in Predicting Balance and Fall Risk in a Neuro-Rehabilitation Setting

    Get PDF
    INTRODUCTION: There is a consistent body of evidence supporting the role of cognitive functions, particularly executive function, in the elderly and in neurological conditions which become more frequent with ageing. The aim of our study was to assess the role of different domains of cognitive functions to predict balance and fall risk in a sample of adults with various neurological conditions in a rehabilitation setting. METHODS: This was a prospective, cohort study conducted in a single centre in the UK. 114 participants consecutively admitted to a Neuro-Rehabilitation Unit were prospectively assessed for fall accidents. Baseline assessment included a measure of balance (Berg Balance Scale) and a battery of standard cognitive tests measuring executive function, speed of information processing, verbal and visual memory, visual perception and intellectual function. The outcomes of interest were the risk of becoming a faller, balance and fall rate. RESULTS: Two tests of executive function were significantly associated with fall risk, the Stroop Colour Word Test (IRR 1.01, 95% CI 1.00-1.03) and the number of errors on part B of the Trail Making Test (IRR 1.23, 95% CI 1.03-1.49). Composite scores of executive function, speed of information processing and visual memory domains resulted in 2 to 3 times increased likelihood of having better balance (OR 2.74 95% CI 1.08 to 6.94, OR 2.72 95% CI 1.16 to 6.36 and OR 2.44 95% CI 1.11 to 5.35 respectively). CONCLUSIONS: Our results show that specific subcomponents of executive functions are able to predict fall risk, while a more global cognitive dysfunction is associated with poorer balance

    Women's Intentions to Engage in Risk-Reducing Behaviours after Receiving Personal Ovarian Cancer Risk Information: An Experimental Survey Study

    Get PDF
    Risk stratification using genetic and/or other types of information could identify women at increased ovarian cancer risk. The aim of this study was to examine women's potential reactions to ovarian cancer risk stratification. A total of 1017 women aged 45-75 years took part in an online experimental survey. Women were randomly assigned to one of three experimental conditions describing hypothetical personal results from ovarian cancer risk stratification, and asked to imagine they had received one of three results: (a) 5% lifetime risk due to single nucleotide polymorphisms (SNPs) and lifestyle factors; (b) 10% lifetime risk due to SNPs and lifestyle factors; (c) 10% lifetime risk due to a single rare mutation in a gene. Results: 83% of women indicated interest in having ovarian cancer risk assessment. After receiving their hypothetical risk estimates, 29% of women stated they would have risk-reducing surgery. Choosing risk-reducing surgery over other behavioural responses was associated with having higher surgery self-efficacy and perceived response-efficacy, but not with perceptions of disease threat, i.e., perceived risk or severity, or with experimental condition. A substantial proportion of women age 45-75 years may be open to the idea of surgery to reduce risk of ovarian cancer, even if their absolute lifetime risk is only increased to as little as 5 or 10%
    corecore