393 research outputs found

    Sexual Selection for Male Mobility in a Giant Insect with Female‐Biased Size Dimorphism

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    Female-biased size dimorphism in which females are larger than males is prevalent in many animals, but the factors causing this pattern of dimorphism are still poorly understood. The agility hypothesis suggests that female-biased size dimorphism arises because smaller males are favoured in scramble competition for mates. Using radio telemetry, we assessed the agility hypothesis in the Cook Strait giant weta (Deinacrida rugosa), a species with strong female-biased size dimorphism, and tested the prediction that male traits promoting mobility (i.e. longer legs, smaller bodies) are useful in scramble competition for mates and thus promote reproductive success. Our predictions were supported: males with longer legs and smaller bodies exhibited greater mobility (daily linear displacement when not mating) and more mobile males had greater insemination success. No phenotypic traits predicted female mobility or insemination success. In species with female-biased size dimorphism, sexual selection on males is often considered to be weak compared to species in which males are large and/or possess weaponry. We found that male giant weta experience sexual selection intensities on par with males of a closely related harem-defending polygynous species, likely because of strong scramble competition with other males

    Radio-telemetric evidence of migration in the gregarious but not the solitary morph of the Mormon cricket (Anabrus simplex : Orthoptera: Tettigoniidae

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    Abstract The Mormon cricket, Anabrus simplex, is one of just a few species of katydids (or bushcrickets, Orthoptera: Tettigoniidae) that, like migratory locusts, appear to have solitary and migratory morphs. Using radio telemetry we studied movements of individuals of two morphs of this flightless species. Individuals within each migratory band had similar rates of movements along similar directional headings whereas solitary individuals moved little and showed little evidence of directionality in movement. Our results also add to other recent radio-telemetry studies showing that flightless insects of 1-2 g in mass can be tracked successfully using these methods

    Mutual Information for the Detection of Crush

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    Fatal crush conditions occur in crowds with tragic frequency. Event organizers and architects are often criticised for failing to consider the causes and implications of crush, but the reality is that both the prediction and prevention of such conditions offer a significant technical challenge. Full treatment of physical force within crowd simulations is precise but often computationally expensive; the more common method of human interpretation of results is computationally “cheap” but subjective and time-consuming. This paper describes an alternative method for the analysis of crowd behaviour, which uses information theory to measure crowd disorder. We show how this technique may be easily incorporated into an existing simulation framework, and validate it against an historical event. Our results show that this method offers an effective and efficient route towards automatic detection of the onset of crush

    Increasing the simulation performance of large-scale evacuations using parallel computing techniques based on domain decomposition

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    Evacuation simulation has the potential to be used as part of a decision support system during large-scale incidents to provide advice to incident commanders. To be viable in these applications, it is essential that the simulation can run many times faster than real time. Parallel processing is a method of reducing run times for very large computational simulations by distributing the workload amongst a number of processors. This paper presents the development of a parallel version of the rule based evacuation simulation software buildingEXODUS using domain decomposition. Four Case Studies (CS) were tested using a cluster, consisting of 10 Intel Core 2 Duo (dual core) 3.16 GHz CPUs. CS-1 involved an idealised large geometry, with 20 exits, intended to illustrate the peak computational speed up performance of the parallel implementation, the population consisted of 100,000 agents; the peak computational speedup (PCS) was 14.6 and the peak real-time speedup (PRTS) was 4.0. CS-2 was a long area with a single exit area with a population of 100,000 agents; the PCS was 13.2 and the PRTS was 17.2. CS-3 was a 50 storey high rise building with a population of 8000/16,000 agents; the PCS was 2.48/4.49 and the PRTS was 17.9/12.9. CS-4 is a large realistic urban area with 60,000/120,000 agents; the PCS was 5.3/6.89 and the PRTS was 5.31/3.0. This type of computational performance opens evacuation simulation to a range of new innovative application areas such as real-time incident support, dynamic signage in smart buildings and virtual training environments

    Oecanthus nigricornis (Orthoptera: Gryllidae) as the first known host of Stylogaster neglecta (Diptera: Conopidae)

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    The conopid fly Stylogaster neglecta Williston (Diptera: Conopidae) is a parasitoid with no known host. We report this species as the first recorded dipteran parasitoid of Oecanthus nigricornis Walker (Orthoptera: Gryllidae) (black-horned tree crickets). We reared field-collected O. nigricornis juveniles over several months in 2017 and found that larval S. neglecta emerged from them during late July into August. We estimated the incubation period for S. neglecta larvae to be around 30 days based on the length of time it took for them to emerge from the host and pupate (subsequently all hosts died). We documented several cases of multiple parasitism. In 2018, we dissected O. nigricornis sampled from four sites across southern Ontario, Canada and upstate New York, United States of America and found that the percentage of juvenile O. nigricornis parasitised ranged 2–39%. Further sampling will be necessary to determine whether this variation represents consistent population differences or between-year variation in parasitism

    Enhanced Colorimetric Differentiation between Staphylococcus aureus and Pseudomonas aeruginosa Using a Shape-Encoded Sensor Hydrogel

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    Herein, we demonstrate a combined fluorescent probe/shape-encoded hydrogel strategy for the fast, sensitive, and selective detection of bacterial species via their characteristic enzymes. A poly(vinyl alcohol) (PVA) hydrogel loaded with the fluorescent probe N,N′-(3-oxo-3H-spiro[isobenzofuran-1,9′-xanthene]-3′,6′-diyl)bis(2,2,3,3,3-pentafluoropropanamide) (ACS-HNE) was designed for the detection of elastase, an enzyme produced by Pseudomonas aeruginosa. Likewise, a chitosan-derived hydrogel was loaded with the fluorescent probe 4-methylumbelliferyl-α-d-glucopyranoside (MUD) by entrapment for the selective detection of α-glucosidase, an enzyme produced by Staphylococcus aureus. For an observation time of 60 min, limits of detection (LODs) of ≤20 nM for elastase and ≤30 pM for α-glucosidase were obtained, which in the latter case is 3 orders of magnitude better than related chitosan systems with covalently coupled substrate. To illustrate the potential utility of these highly sensitive sensor hydrogels as a simple point-of-care test system, shaped hydrogel slabs representing the letters P and S were manufactured to detect P. aeruginosa and S. aureus, respectively. These shapes were shown to provide an additional unique color code under UV illumination corresponding to the characteristic enzyme produced by the corresponding bacteria. This study shows potential for the future development of an effective and simple point-of-care test for the rapid identification of bacterial species that can be operated by nonspecialists

    “No One Manages It; We Just Sign Them Up and Do It”: A Whole System Analysis of Access to Healthcare in One Remote Australian Community

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    Objective: To assess the accessibility, availability and utilisation of a comprehensive range of community-based healthcare services for Aboriginal people and describe contributing factors to providing effective healthcare services from the provider perspective. Setting: A remote community in New South Wales, Australia. Participants: Aboriginal and non-Aboriginal health and education professionals performing various roles in healthcare provision in the community. Design: Case study. Methodology: The study was co-designed with the community. A mixed-methods methodology was utilised. Data were gathered through structured interviews. Descriptive statistics were used to analyse the availability of 40 health services in the community, whilst quotations from the qualitative research were used to provide context for the quantitative findings. Results: Service availability was mapped for 40 primary, specialised, and allied health services. Three key themes emerged from the analysis: (1) there are instances of both underservicing and overservicing which give insight into systemic barriers to interagency cooperation; (2) nurses, community health workers, Aboriginal health workers, teachers, and administration staff have an invaluable role in healthcare and improving patient access to health services and could be better supported through further funding and opportunities for specialised training; and (3) visiting and telehealth services are critical components of the system that must be linked to existing community-led primary care services. Conclusion: The study identified factors influencing service availability, accessibility and interagency cooperation in remote healthcare services and systems that can be used to guide future service and system planning and resourcing

    NEOSCOPE: A randomized phase II study of induction chemotherapy followed by oxaliplatin/capecitabine or carboplatin/paclitaxel based pre-operative chemoradiation for resectable oesophageal adenocarcinoma

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    Background: Oxaliplatin-capecitabine (OxCap) and carboplatin-paclitaxel (CarPac) based neo-adjuvant chemoradiotherapy (nCRT) have shown promising activity in localised, resectable oesophageal cancer. Patients and methods: A non-blinded, randomised (1:1 via a centralised computer system), ‘pick a winner’ phase II trial. Patients with resectable oesophageal adenocarcinoma ≥ cT3 and/or ≥ cN1 were randomised to OxCapRT (oxaliplatin 85 mg/m2 day 1, 15, 29; capecitabine 625 mg/m2 bd on days of radiotherapy) or CarPacRT (carboplatin AUC2; paclitaxel 50 mg/m2 day 1, 8, 15, 22, 29). Radiotherapy dose was 45 Gy/25 fractions/5 weeks. Both arms received induction OxCap chemotherapy (2 × 3 week cycles of oxaliplatin 130 mg/m2 day 1, capecitabine 625 mg/m2 bd days 1–21). Surgery was performed 6–8 weeks after nCRT. Primary end-point was pathological complete response (pCR). Secondary end-points included toxicity, surgical morbidity/mortality, resection rate and overall survival. Statistics: Based on pCR ≤ 15% not warranting future investigation, but pCR ≥ 35% would, 76 patients (38/arm) gave 90% power (one-sided alpha 10%), implying that arm(s) having ≥10 pCR out of first 38 patients could be considered for phase III trials. ClinicalTrials.gov: NCT01843829. Funder: Cancer Research UK (C44694/A14614). Results: Eighty five patients were randomised between October 2013 and February 2015 from 17 UK centres. Three of 85 (3.5%) died during induction chemotherapy. Seventy-seven patients (OxCapRT = 36; CarPacRT = 41) underwent surgery. The 30-d post-operative mortality was 2/77 (2.6%). Grade III/IV toxicity was comparable between arms, although neutropenia was higher in the CarPacRT arm (21.4% versus 2.6%, p = 0.01). Twelve of 41 (29.3%) (10 of first 38 patients) and 4/36 (11.1%) achieved pCR in the CarPacRT and OxcapRT arms, respectively. Corresponding R0 resection rates were 33/41 (80.5%) and 26/36 (72.2%), respectively. Conclusion: Both regimens were well tolerated. Only CarPacRT passed the predefined pCR criteria for further investigation

    Boronate ester cross-linked PVA hydrogels for the capture and H2O2-mediated release of active fluorophores

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    A new set of PVA hydrogels were formed using the boronate ester fluorescent probe, PF1 and the novel boronate fluorescent probe PT1 as the covalent crosslinkers. Treatment with aqueous H2O2 allowed triggered release of the fluorescent dye accompanied by complete dissolution of the hydroge
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