374 research outputs found

    Solution to Problem 1751, A Combinatorial Identity

    Get PDF
    A combinatorial proof to Iliya Bluskov\u27s proposed Problem 1751

    The knowledge, attitudes and beliefs of midwives on the vaccination coverage rates in Perth’s Aboriginal children

    Get PDF
    Background: Midwives are well placed to promote vaccination awareness throughout a women’s pregnancy and strengthen childhood vaccination demand following hospital discharge. In Perth, Western Australia, Aboriginal children experience some of the lowest vaccination coverage rates across the nation. To identify factors preventing greater vaccination uptake amongst the target population, a theory-based study was conducted with midwives across two Perth maternity hospitals to explore behavioural attributes, knowledge, attitudes and beliefs surrounding vaccination provision and the vaccines administered to Aboriginal children. Methods: A purpose-designed questionnaire was distributed to midwives working in two Perth public maternity hospitals. The proximal constructs of The Theory of Planned Behavior were used to frame the questionnaire to enable the barriers to greater vaccination coverage to be identified and behaviourally situated. Descriptive statistics described the demographics of the study sample. Chi-square and the Fisher’s exact test were used to identify associations between midwife characteristics and awareness of the coverage rates. Significance was set at α = 0.05. Results: Of the 58 midwives who completed the study questionnaire, 77.2% were unaware of the sub-optimal vaccination coverage in Perth’s Aboriginal children. Level of education (p = 0.53) and years worked as a practising midwife (p = 0.47) were not found to be associated with an awareness of the coverage rates. Approximately, 50% of midwives reported some concern over the efficacy of childhood vaccines, 44.4% did not feel confident with their knowledge of vaccines, while 33.3% do not routinely discuss childhood vaccinations with parents prior to hospital discharge. Conclusions: Key findings in the study identified that a range of educational, leadership and system-based issues are affecting midwives’ capacity to play a more substantial role in influencing vaccination coverage in Perth’s Aboriginal children

    Drying of complex suspensions

    Full text link
    We investigate the 3D structure and drying dynamics of complex mixtures of emulsion droplets and colloidal particles, using confocal microscopy. Air invades and rapidly collapses large emulsion droplets, forcing their contents into the surrounding porous particle pack at a rate proportional to the square of the droplet radius. By contrast, small droplets do not collapse, but remain intact and are merely deformed. A simple model coupling the Laplace pressure to Darcy's law correctly estimates both the threshold radius separating these two behaviors, and the rate of large-droplet evacuation. Finally, we use these systems to make novel hierarchical structures.Comment: 4 pages, 4 figure

    Wild and domestic savanna herbivores increase smaller vertebrate diversity, but less than additively

    Get PDF
    Cattle and other livestock graze more than a quarter of the world's terrestrial area and are widely regarded to be drivers of global biodiversity declines. Studies often compare the effects of livestock presence/absence but, to our knowledge, no studies have tested for interactive effects between large wild herbivores and livestock at varying stocking rates on small-bodied wild vertebrates. We investigated the effects of cattle stocking rates (none/moderate/high) on the diversity of wildlife 0.05–1,000 kg using camera traps at a long-term exclosure experiment within a semi-arid savanna ecosystem in central Kenya. In addition, by selectively excluding wild ‘mesoherbivores’ (50–1,000 kg) and ‘megaherbivores’ (>1,000 kg; elephant and giraffe), we tested whether the presence of these two wild herbivore guilds (collectively, ‘larger wild herbivores’) mediates the effect of cattle stocking rate on habitat use and diversity of ‘smaller wildlife’ (mammals ranging between 10 and 70 cm shoulder height and birds). Our results show that cattle enhance alpha diversity of smaller wildlife (with or without larger wild herbivore presence) and of all wildlife 0.05–1,000 kg (with or without megaherbivore presence), by altering vegetation structure. However, for smaller wildlife, this effect is less pronounced in the presence of larger wild herbivores, which also shorten grass. In the absence of cattle, mesoherbivore-accessible sites showed higher alpha diversity of smaller wildlife than sites excluding mesoherbivores. Smaller wildlife habitat use was increased by high cattle stocking rates and wild mesoherbivores more in the presence of the other. Synthesis and applications. Our findings imply that grazing, whether by livestock or wildlife, can enhance local savanna wildlife diversity. The biodiversity benefits of localised increases in herbivory are likely to be due to shortened grass and associated visibility improvements (for predator avoidance/foraging). This suggests that land managers can increase local biodiversity by shortening grass, with wild or domestic herbivores (or both), at least in patches within a taller grass matrix

    CIRCE: Coordinated Ionospheric Reconstruction Cubesat Experiment

    Get PDF
    The Coordinated Ionospheric Reconstruction Cubesat Experiment (CIRCE) is a collaborative space mission between the UK Defence Science and Technology Laboratory (Dstl), and the US Naval Research Laboratory (NRL) in developing small satellite ionospheric physics capability. CIRCE will characterise space weather effects on a regional scale in the ionosphere/thermosphere system. Properly characterising the dynamic ionosphere is important for a wide range of both civil and defence applications such as GPS, communications, and sensing technology. Consisting of two near-identical 6U (2x3U) CubeSat buses, the CIRCE nanosatellites will fly in a lead-follow tandem configuration in co-planar near-polar orbits at 500km altitude. Provided by Blue Canyon Technologies (BCT), the two buses will use differential drag to achieve and maintain an in-track separation of between 250 and 500km, allowing short time-scale dynamics to be observed in-situ. These nanosatellites each carry a complement of 5 individual scientific instruments, contributed from academic, industrial, and government partners across the UK and US. Scheduled to launch in 2021 via the US Department of Defence Space Test Program, the two CIRCE satellites will provide observations to enable a greater understanding of the driving processes of geophysical phenomena in the ionosphere/thermosphere system, distributed across a wide range of latitudes, and altitudes, as the mission progresses

    Dietary antioxidant intake and the risk of developing Barrett’s oesophagus and oesophageal adenocarcinoma

    Get PDF
    Background: We investigated in a cohort study, for the first time using 7-day food diaries (7-DFDs), for age-dependent inverse associations with antioxidants, which have anti-carcinogenic properties, and development of Barrett’s oesophagus (BO) and oesophageal adenocarcinoma (OAC). Methods: A total of 24,068 well individuals completed 7-DFDs and donated blood. Vitamins C and E, carotenes, zinc and selenium intakes, and plasma vitamin C were measured. Participants were monitored for 15 years for BO and OAC. Hazard ratios (HRs) were estimated for: quintiles of intake and in participants younger and >=65 years at recruitment, the midpoint of BO peak prevalence. Results: A total of 197 participants developed BO and 74 OAC. There were no significant associations between antioxidants and BO or OAC in the whole cohort or if >65 years at recruitment. In participants <65 years, for BO, there was an inverse trend across plasma vitamin C quintiles (trend HR = 0.82; 95% CI = 0.71–0.96, P = 0.01), OAC for plasma vitamin C (trend HR = 0.58; 95% CI = 0.37–0.92, P = 0.02) and for dietary vitamins C and E (trend HR = 0.71 95% CI = 0.51–0.99, P = 0.04 and trend HR = 0.70; 95% CI = 0.51–0.96; P = 0.03). Conclusions: Data supports a role for dietary antioxidants prevent BO and OAC, perhaps at the earlier stages of carcinogenesis

    Electrical-hydraulic relationships observed for unconsolidated sediments in the presence of a cobble framework

    Get PDF
    Mechanistic models now exist to predict hydraulic conductivity (K) from the spectral induced polarization (SIP) response of granular media. We examined the predictions of such a model on unconsolidated coarse fluvial sediments and compared them to those obtained with a modified Kozeny Carman (KC) model. Samples were retrieved from the Boise Hydrogeophysical Research Site (BHRS), located on a gravel bar adjacent to the Boise River, Idaho. A sample holder (0.102 m diameter and 0.12 m in length) was designed to include the cobble framework in reconstituted samples representing the primary stratigraphic units defined based on porosity variation at this site. SIP (0.001-1000 Hz) and K (from Darcy tests) measurements were recorded for twelve samples, with SIP measurements made as a function of pore fluid conductivity (3-300 mS/m); grain, grain size distribution (GSD) and total porosity. K prediction with the KC model was improved after discounting of the cobble framework and multiplying by the tortuosity resulting from matrix “capillaries” around the cobbles, resulting in estimates within 0.5 orders of magnitude of the measurements. K prediction with a mechanistic SIP model based on Stern layer polarization (SLP model) that requires an estimate of the GSD alsoalso required discounting for the cobble framework to obtain estimates within 0.5 orders of magnitude of the measurements. Similarly, the SLP model over predicts the measured imaginary conductivity (σ") unless the cobble framework is discounted, which then results in estimates of σ” within 0.1 orders of magnitude of the measurements. This can be explained by the fact that the cobbles polarize at frequencies well below the minimum measurement frequency (0.001 Hz). The SLP model for K prediction parameterized in terms of the formation factor and imaginary conductivity performed well for the ten samples with a cobble framework without modification as the imaginary conductivity directly senses the matrix grain size characteristics, whereas the formation factor captures the porosity reduction and tortuosity resulting from the presence of the cobble framework (capillary tortuosity). Our findings suggest that the estimation of contrasts in hydraulic conductivityK in coarse sediments may be achievable through measurements of electrical properties after appropriate consideration of the cobble fractio

    ISBS 2018 AUCKLAND CONFERENCE SPRINZ-HPSNZ-AUT MILLENNIUM APPLIED PROGRAMME

    Get PDF
    An interactive afternoon of sessions delivered by High Performance Sport New Zealand (HPSNZ) and AUT SPRINZ Biomechanists, Performance Analysts and other biomechanics relevant sport facing practitioners. The 11 sessions are at AUT Millennium (AUTM), which is a satellite site of AUT University and the Auckland training hub for many HPSNZ supported sports such as athletics, sailing, and swimming. These sports and others (cycling, rowing, snow sports etc.) will be represented in the line-up. The applied sessions involve practical demonstrations of aspects of analysis and/or tools used to deliver in the field to directly positively impact athletes performances on the world stage. Following these engaging sessions there will be tasting of New Zealand wine, allowing for further discussion and networking. Sir Graeme Avery will be acknowledged for his contribution to sport science. Mike Stanley is AUT Millennium Chief Executive & NZ Olympic Committee President will explain the partners in the facility. AUT Millennium is a charitable trust established to help New Zealanders live longer and healthier lives, and to enjoy and excel in sport through the provision of world-class facilities, services, research and education. Founded in 2002 as Millennium Institute of Sport and Health (MISH) by Sir Stephen Tindall and Sir Graeme Avery as a premium health and fitness facility for both athletes and the public alike. Partnered with AUT University in 2009, forming AUT Millennium, to expand research and education in the sporting sector. Professor Barry Wilson is an Adjunct Professor with SPRINZ at Auckland University of Technology and will be outlining the research and student opportunities. Martin Dowson is the General Manager Athlete Performance Support at High Performance Sport New Zealand and has overall responsibility for the programme. Simon Briscoe, AUT Millennium Applied Session Coordinator, is the head of the Performance and Technique Analysis discipline within HPSNZ. Simon is coordinating the applied sessions along with technical support from Dr Allan Carman, Research Fellow, AUT SPRINZ. Jodi Cossor and Matt Ingram will provide a demonstration of a multidisciplinary approach driven by biomechanical analysis for Paralympic swimmers. Justin Evans and Sarah-Kate Millar will provide a practical session assessing the athletes rowing stroke to assist the coach on technical changes. This session will demonstrate various rowing traits and how the biomechanist and coach can work together to optimise boat speed. Mike Schofield and Kim Hébert-Losier will provide a session looking at shotput and the evidence based approach to coaching. Dr Craig Harrison and Professor John Cronin will provide examples from the AUTM Athlete Development programme. Kim Simperingham and Jamie Douglas who work with high performance rugby athletes will outline sprinting mechanics in practice. Dr Bruce Hamilton, Fiona Mather, Justin Ralph and Rone Thompson will demonstrate the approach of HPSNZ and Cycling NZ performance health teams in the use of some specific tools for prevention of injury and optimisation of performance. Kelly Sheerin, Denny Wells and Associate Professor Thor Besier will provide examples of using IMU and motion capture methods for running and basketball biomechanics research, education and service. Dr Rodrigo Bini and Associate Professor Andrew Kilding will show how linking of biomechanics and physiology improves injury prevention and performance enhancement. Robert Tang, Andre de Jong and Farhan Tinwala discuss select projects developed by Goldmine, HPSNZ’s in-house engineering team, and how these innovations have enabled unprecedented levels of biomechanics feedback. Cameron Ross and Paul McAlpine demonstrate the technology being used at the Snow Sports NZ training centre in Cadrona to enhance load monitoring of athletes. This application allows greater insight into training performances and biomechanical loads than has been previously possible in the training environment. AUT Millennium tour guides are coordinated by Josh McGeown and include Enora Le Flao, Dustin Oranchuk, Erika Ikeda, Jono Neville, Aaron Uthoff, Andrew Pichardo, Farhan Tinwala, Shelley Diewald, Renata Bastos Gottgtroy, Jessica Yeoman, Casey Watkins, Eric Harbour, Anja Zoellner, Alyssa Joy Spence, Victor Lopez Jr, and Albert Chang
    corecore