1,445 research outputs found

    Variable ÎŽ15N Diet-Tissue Discrimination Factors among Sharks: Implications for Trophic Position, Diet and Food Web Models

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    The application of stable isotopes to characterize the complexities of a species foraging behavior and trophic relationships is dependent on assumptions of ή(15)N diet-tissue discrimination factors (∆(15)N). As ∆(15)N values have been experimentally shown to vary amongst consumers, tissues and diet composition, resolving appropriate species-specific ∆(15)N values can be complex. Given the logistical and ethical challenges of controlled feeding experiments for determining ∆(15)N values for large and/or endangered species, our objective was to conduct an assessment of a range of reported ∆(15)N values that can hypothetically serve as surrogates for describing the predator-prey relationships of four shark species that feed on prey from different trophic levels (i.e., different mean ή(15)N dietary values). Overall, the most suitable species-specific ∆(15)N values decreased with increasing dietary-ή(15)N values based on stable isotope Bayesian ellipse overlap estimates of shark and the principal prey functional groups contributing to the diet determined from stomach content analyses. Thus, a single ∆(15)N value was not supported for this speciose group of marine predatory fishes. For example, the ∆(15)N value of 3.7‰ provided the highest percent overlap between prey and predator isotope ellipses for the bonnethead shark (mean diet ή(15)N = 9‰) whereas a ∆(15)N value < 2.3‰ provided the highest percent overlap between prey and predator isotope ellipses for the white shark (mean diet ή(15)N = 15‰). These data corroborate the previously reported inverse ∆(15)N-dietary ή(15)N relationship when both isotope ellipses of principal prey functional groups and the broader identified diet of each species were considered supporting the adoption of different ∆(15)N values that reflect the predators' ή(15)N-dietary value. These findings are critical for refining the application of stable isotope modeling approaches as inferences regarding a species' ecological role in their community will be influenced with consequences for conservation and management actions

    Human visual cortical responses to specular and matte motion flows

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    Determining the compositional properties of surfaces in the environment is an important visual capacity. One such property is specular reflectance, which encompasses the range from matte to shiny surfaces. Visual estimation of specular reflectance can be informed by characteristic motion profiles; a surface with a specular reflectance that is difficult to determine while static can be confidently disambiguated when set in motion. Here, we used fMRI to trace the sensitivity of human visual cortex to such motion cues, both with and without photometric cues to specular reflectance. Participants viewed rotating blob-like objects that were rendered as images (photometric) or dots (kinematic) with either matte-consistent or shiny-consistent specular reflectance profiles. We were unable to identify any areas in low and mid-level human visual cortex that responded preferentially to surface specular reflectance from motion. However, univariate and multivariate analyses identified several visual areas; V1, V2, V3, V3A/B, and hMT+, capable of differentiating shiny from matte surface flows. These results indicate that the machinery for extracting kinematic cues is present in human visual cortex, but the areas involved in integrating such information with the photometric cues necessary for surface specular reflectance remain unclear. © 2015 Kam, Mannion, Lee, Doerschner and Kersten

    UpLIFTIng PFI: does LIFT improve public-private procurement?

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    The Private Finance Initiative (PFI) and Local Improvement Finance Trust (LIFT) were both introduced by the UK government as part of a drive to improve public service provision. Both PFI and LIFT focus on leveraging the key strengths of the public and private sectors when developing new facilities. This paper does not seek to question the need for new infrastructure, but rather discusses the difficulties encountered when trying to analyse LIFT as a system and when evaluating whether it can address earlier concerns about the PFI procurement process. Our analysis suggests that it is difficult to predict whether LIFT will be capable of delivering on its promise of providing cost-effective, bespoke Primary Care facilities

    Life History of Paracoccus marginatus (Hemiptera: Pseudococcidae) on Four Host Plant Species Under Laboratory Conditions

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    Life history of the mealybug, Paracoccus marginatus Williams and Granara de Willink, on three ornamental plants [Hibiscus rosa-sinensis L., Acalypha wilkesiana (Muell.-Arg.), and Plumeria rubra L.] and one weed species (Parthenium hysterophorus L.) was studied under laboratory conditions. Mealybugs were able to develop, survive, and reproduce on all four hosts; however, there were differences in the life history parameters. Adult females that developed on acalypha and parthenium emerged ≈1 d earlier than those that developed on hibiscus and plumeria. Adult males had a longer developmental time on plumeria than on the other hosts. Survival of first- and second-instar nymphs and cumulative adult survival were lowest on plumeria. Longevity was not affected by hosts for males and females and averaged 2.3 ± 0.1 and 21.2 ± 0.1 d, respectively. On plumeria, 58.9 ± 1.7% of the adults were females, which was a higher female percentage than on the other hosts. No egg production occurred in virgin females. Prereproductive and reproductive periods of the females were not affected by hosts and averaged 6.3 ± 0.1 and 11.2 ± 0.1 d, respectively. Mean fecundity of 186.3 ± 1.8 eggs on plumeria was lower than on the other three plant species. Life history parameters of P. marginatus on hibiscus, acalypha, plumeria, and parthenium show its ability to develop, survive, and reproduce on a wide variety of plant species

    Second specimen of the Late Cretaceous sauropod dinosaur Diamantinasaurus matildae provides new anatomical information on skull and neck evolution in early titanosaurs and the biogeographic origins of Australian dinosaur faunas

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    The titanosaurian sauropod dinosaur Diamantinasaurus matildae is represented by two individuals from the Cenomanian–lower Turonian ‘upper’ Winton Formation of central Queensland, north-eastern Australia. The type specimen has been described in detail, whereas the referred specimen, which includes several elements not present in the type series (partial skull, atlas, axis and postaxial cervical vertebrae), has only been described briefly. Herein, we provide a comprehensive description of this referred specimen, including a thorough assessment of the external and internal anatomy of the braincase, and identify several new autapomorphies of D. matildae. Via an expanded data matrix consisting of 125 taxa scored for 552 characters, we recover a close, well-supported relationship between Diamantinasaurus and its contemporary, Savannasaurus elliottorum. Unlike previous iterations of this data matrix, under a parsimony framework we consistently recover Diamantinasaurus and Savannasaurus as early-diverging members of Titanosauria using both equal weighting and extended implied weighting, with the overall topology largely consistent between analyses. We erect a new clade, named Diamantinasauria herein, that also includes the contemporaneous Sarmientosaurus musacchioi from southern Argentina, which shares several cranial features with the referred Diamantinasaurus specimen. Thus, Diamantinasauria is represented in the mid-Cretaceous of both South America and Australia, supporting the hypothesis that some titanosaurians, in addition to megaraptoran theropods and possibly some ornithopods, were able to disperse between these two continents via Antarctica. Conversely, there is no evidence for rebbachisaurids in Australia, which might indicate that they were unable to expand into high latitudes before their extinction in the Cenomanian–Turonian. Likewise, there is no evidence for titanosaurs with procoelous caudal vertebrae in the mid-Cretaceous Australian record, despite scarce but compelling evidence for their presence in both Antarctica and New Zealand during the Campanian–Maastrichtian. These later titanosaurs presumably dispersed into these landmasses from South America before the Campanian (~85 Mya), when seafloor spreading between Zealandia and Australia commenced. Although Australian mid-Cretaceous dinosaur faunas appear to be cosmopolitan at higher taxonomic levels, closer affinities with South America at finer scales are becoming better supported for sauropods, theropods and ornithopods

    A Review of the Effect of Nurses’ Use of Smartphone to Improve Patient Care

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    Introduction: Nurses in the acute-care setting use touchscreen smartphones (eg. iPhones) to facilitate patient care. However, on duty nurses also use smartphones to access social media, text, and shop online. The overall benefit of nurses’ use of smartphones to patient care is unclear. We conducted a systematic review to examine the use of smartphones by acute-care nurses and how that influences patient care.Methods: We searched Embase, MEDLINE, PsycINFO, CINAHL, and PubMed databases using the key words “smartphone,” “nurse,” “patient care” and “quality of care” to identify articles focusing on smartphone use by nurses in acute care setting. Only 274 articles were initially identified. Fourteen articles remained after applying inclusion criteria such as nurses in acute care setting, written in English, and excluding those addressing the use of smartphones by non-nurses.Results: We identified six themes encompassing advantages and disadvantages of smartphone use by nurses in the acute care setting. Theme 1: enhanced interprofessional communication. Theme 2: easy and quick access to clinical information (eg. medications). Theme 3: improved time-management. Theme 4: reduction of work stress. Disadvantages were: Theme 5: distraction from work, and Theme 6: the appearance of unprofessionalism.Conclusions: Smartphone use by nurses in the acute care setting impacts how they provide daily care to their patients. Benefits of smartphone use include: improved patient safety, more effective communication between healthcare providers, and better time-management. Disadvantages found included distraction of nurses at work, and the perceived appearance of unprofessionalism. We believe there is an unmeasured risk of smartphones as potential vectors of infection. We support the use of smartphones to aid in patient care but recommend that education is necessary on the appropriate use of smartphones to mitigate risks such as infection, distraction, and accountability of personal use

    Tracking of Salmonella Positive Pigs from Farm to Fork in the Republic of Ireland

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    In this study, individual pigs from selected herds of known Salmonella serological status were tracked through the slaughter and dressing process. From all tracked animals, caecal contents, rectal faeces, carcasses (before washing and chilling and after chilling) and pork primal cuts were examined for the presence of Salmonella. All samples were screened for Salmonella using real time PCR and all suspect positive samples were confirmed using the ISO 6579 method for Salmonella. To determine the relationship between Salmonella isolates from different parts of the chain , all isolates are being characterised by Pulse Field Gel Electrophoresis (PFGE). The results suggest that the slaughter and dressing operations have a significant effect on the incidence of Salmonella and that even if pigs are presented for slaughter with caecal or rectal carriage of Salmonella then good slaughter practices can prevent carcass contamination. All data generated in the study is being fed into a quantitative risk assessment model for Salmonella in pork
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