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The interaction between porous structures and flows with mean and oscillatory components has many applications in fluid dynamics. One such application is the hydrodynamic forces on offshore jacket structures from waves and current, which have been shown to give a significant blockage effect, leading to a reduction in drag forces. To better understand this, we derived analytical expressions that describe the effect of current on drag forces from large waves, and conducted experiments that measured forces on a model jacket in collinear waves and currents. We utilised symmetry and phase-inversion techniques, relying on the underlying physics of wave structure interaction, to separate Morison drag and inertia-type forces and to decompose these forces into their respective frequency harmonics. We find that the odd harmonics of the drag force mostly contain the loads from waves, while even harmonics vary much more rapidly with the current speed flowing through the jacket. At the time of peak force, these current speeds were estimated to be 40 % of the undisturbed current and 50 % of the industry-standard estimates, a result that has significant implications for design and re-assessment of jackets. At times away from the peak force, when there are no waves and only current, the blockage effects are reduced. Hence, the variation in blocked current speeds appears to occur on a relatively fast time scale similar to the compact wave envelope. These findings may be generalisable to any jacket-type structure in flows with mean and high Keulegan–Carpenter number oscillatory components.
We consider the dynamic wetting and dewetting processes of films and droplets of complex liquids on planar surfaces, focusing on the case of colloidal suspensions, where the particle interactions can be sufficiently attractive to cause agglomeration of the colloids within the film. This leads to an interesting array of dynamic behaviours within the liquid and of the liquid–air interface. Incorporating concepts from thermodynamics and using the thin-film approximation, we construct a model consisting of a pair of coupled partial differential equations that represent the evolution of the liquid film and the effective colloidal height profiles. We determine the relevant phase behaviour of the uniform system, including finding associated binodal and spinodal curves, helping to uncover how the emerging behaviour depends on the particle interactions. Performing a linear stability analysis of our system enables us to identify parameter regimes where agglomerates form, which we independently confirm through numerical simulations and continuation of steady states, to construct bifurcation diagrams. We obtain various dynamics such as uniform colloidal profiles in an unstable situation evolving into agglomerates and thus elucidate the interplay between dewetting and particle aggregation in complex liquids on surfaces.
“Challenging the utility of polygenic scores for social science” is a compelling but limited critique. Phenotypic development is sensitive to both initial conditions and all subsequent states – from conception to senescence. Thus, gene-centric analyses are misleading (and often meaningless) because gene products are transformed, and their phenotypic ‘effects' combined and attenuated with successive propagations from molecular and cellular contexts to organismal and social environments.
From the safety inside vehicles, Knowsley Safari offers visitors a close-up encounter with captive olive baboons. As exiting vehicles may be contaminated with baboon stool, a comprehensive coprological inspection was conducted to address public health concerns. Baboon stools were obtained from vehicles, and sleeping areas, inclusive of video analysis of baboon–vehicle interactions. A purposely selected 4-day sampling period enabled comparative inspections of 2662 vehicles, with a total of 669 baboon stools examined (371 from vehicles and 298 from sleeping areas). As informed by our pilot study, front-line diagnostic methods were: QUIK-CHEK rapid diagnostic test (RDT) (Giardia and Cryptosporidium), Kato–Katz coproscopy (Trichuris) and charcoal culture (Strongyloides). Some 13.9% of vehicles were contaminated with baboon stool. Prevalence of giardiasis was 37.4% while cryptosporidiosis was <0.01%, however, an absence of faecal cysts by quality control coproscopy, alongside lower than the expected levels of Giardia-specific DNA, judged RDT results as misleading, grossly overestimating prevalence. Prevalence of trichuriasis was 48.0% and strongyloidiasis was 13.7%, a first report of Strongyloides fuelleborni in UK. We advise regular blanket administration(s) of anthelminthics to the colony, exploring pour-on formulations, thereafter, smaller-scale indicator surveys would be adequate.
Despite the recognition that bone histology provides much information about the life history and biology of extinct animals, osteohistology of extinct marsupials is sorely lacking. We studied the bone histology of the ca. 15-million-year-old Nimbadon lavarackorum from Australia to obtain insight into its biology. The histology of thin sections of five femora and five tibiae of juveniles, subadult, and adult Nimbadon lavarackorum was studied. Growth marks in the bones suggest that N. lavarackorum took at least 7–8 years (and likely longer) to reach skeletal maturity. The predominant bone tissue during early ontogeny is parallel-fibered bone, whereas an even slower rate of bone formation is indicated by the presence of lamellar bone tissue in the periosteal parts of the compacta in older individuals. Deposition of bone was interrupted periodically by lines of arrested growth or annuli. This cyclical growth strategy indicates that growth in N. lavarackorum was affected by the prevailing environmental conditions and available resources, as well as seasonal physiological factors such as decreasing body temperatures and metabolic rates.
Baseline data on local status of threatened species are often limited, and alternative information sources such as local ecological knowledge (LEK) have potential to provide conservation insights but require critical evaluation. We assess the usefulness of LEK to generate conservation evidence for the Hainan Peacock-pheasant Polyplectron katsumatae, a poorly known threatened island galliform. Interview surveys in rural communities across eight forested landscapes on Hainan provided a new dataset of sightings of Peacock-pheasants and other galliforms. Fewer respondents had seen Peacock-pheasants compared to other species across most landscapes, although Peacock-pheasant sightings showed significant across-landscape variation, with substantially more total and recent sightings from Yinggeling National Nature Reserve. However, validation of interview data with camera trapping data from Houmiling Provincial Nature Reserve, a landscape with few reported sightings, suggests a more optimistic possible status for Peacock-pheasants, which were detected as frequently as Red Junglefowl Gallus gallus and Silver Pheasant Lophura nycthemera during systematic camera trap placement. Hainan Peacock-pheasant sighting rates might be influenced by various factors (e.g. restricted local access to forests), with absolute abundance possibly greater than expected from limited sightings. Conversely, relative across-landscape abundance patterns from LEK are likely to be valid, as similar detection biases exist across surveyed landscapes.
The number of people following a vegan diet in the UK is increasing. Eating disorder clinicians are anecdotally reporting that more of their patients with anorexia nervosa are wanting to follow a vegan diet. The relationship between veganism and eating disorders is unclear. A fictitious scenario is used to explore these issues. An approach is described that clinicians may follow to help patients to understand the potential relationship between their eating disorder and veganism. The human rights issues this involves are also explored. It is hoped that this article will make readers more aware of this complex issue and the impact it can have on engagement with services and on treatment options.
Reliable diagnosis of human helminth infection(s) is essential for ongoing disease surveillance and disease elimination. Current WHO-recommended diagnostic assays are unreliable in low-endemic near-elimination settings and typically involve the invasive, onerous and potentially hazardous sampling of bodily fluids such as stool and blood, as well as tissue via biopsy. In contrast, diagnosis by use of non-invasive urine sampling is generally painless, more convenient and low risk. It negates the need for specialist staff, can usually be obtained immediately upon request and is better accepted by patients. In some instances, urine-based diagnostic assays have also been shown to provide a more reliable diagnosis of infection when compared to traditional methods that require alternative and more invasive bodily samples, particularly in low-endemicity settings. Given these relative benefits, we identify and review current research literature to evaluate whether non-invasive urine sampling is currently exploited to its full potential in the development of diagnostic tools for human helminthiases. Though further development, assessment and validation are needed before their routine use in control programmes, low-cost, rapid and reliable assays capable of detecting transrenal helminth-derived antigens and cell-free DNA show excellent promise for future use at the point-of-care in high-, medium- and even low-endemicity elimination settings.
Study of sandstone diagenesis provides information about the origin, texture, distribution and composition of clay minerals, which in turn is used in reservoir description. Three examples of the use of clay mineralogy in reservoir description are given. (1) Kaolinite commonly forms pore-filling cements which are pervasive in specific sandstone intervals. It is shown that water-zone kaolinization homogenizes and lowers the porosity and permeability relative to the oil zone; in a reservoir model different Ø/K relationships are defined above and below the oil-water contact. (2) An occurrence of chlorite in dish-structured horizons is shown to increase horizontal permeability and decrease formation resistivity. The sensitivity of the neutron porosity log to the chlorite cement reduces the usefulness of the log for porosity evaluation. Uncritical application of wireline logs to define reservoir parameters can give pessimistic reservoir evaluation. (3) Sand production can be related to wettability, which in turn is strongly influenced by clay mineralogy. A perforation strategy to minimize sand production may then be based on knowledge of the clay mineralogy of a reservoir.
Reservoir description is achieved by the integration of geological, petrophysical and engineering data. Modelling of reservoir performance is made by creating a three-dimensional model of the reservoir volume, where the reservoir is built of cells and layered zones which are defined geologically. Although the scale of cell size is coarse compared to the scale of geological data, it is important that the geological input to define cells is as precise as possible. The texture of clay minerals and their composition are requisite for understanding their influence on reservoir characteristics. Wireline logs probably do not provide sufficient information about clay mineralogy to evaluate reservoir characteristics, but do allow the extrapolation of ‘point’ mineralogical data into a continuous reservoir description. Evaluation of porosity, permeability and saturation are described, and the possible influence of clay mineralogy on evaluation of these characteristics is discussed.
The headwaters of the Río Pilcomayo drain the Cerro Rico de Potosí precious metal-polymetallic tin deposits of southern Bolivia. Mining of these deposits has taken place for around 500 years, leading to severe contamination of the Pilcomayo's waters and sediments for at least 200 km downstream. Communities living downstream of the mines and processing mills rely on the river water for irrigation, washing and occasionally, cooking and drinking, although most communities take their drinking water from springs located in the mountains above their village. This investigation focuses on arsenic exposure in people living in riverside communities up to 150 km downstream of the source. Sampling took place in April–May 2003 (dry season) and was repeated in January–March 2004 (wet season) in five communities: El Molino, Tasapampa, Tuero Chico, Sotomayor and Cota. Cota was the control in 2003 and again in 2004; a nearby city, Sucre, and several locations in the UK were also used as controls in 2004. Drinking, irrigation and river waters, hair and urine samples were collected in each community, digested where appropriate and analysed for As using ICP-MS. Arsenic concentrations in drinking waters ranged 0.2–112 μg 1–1, irrigation water 0.6–329 μg 1–1, river waters 0.9–12,800 μg 1–1, hair 37–2110 μg kg–1 and urine 11–891 μg 1–1. All but one drinking water sample was found to contain As below the World Health Organization recommended guideline of 10 μg 1–1, although a number of irrigation and river water concentrations were above Canadian and Bolivian guidelines. Many As concentrations in the hair and urine samples from this study exceeded published values for non-occupationally exposed subjects. Analysis of mean concentration values for all media types showed that there were no statistically significant differences between the control locations and the communities exposed to known As contamination, suggesting that the source of As may not be mining-related. Arsenic concentration appears to increase as a function of age in hair samples from males and females older than 30 years. Male volunteers over the age of 35 showed increasing urine-As concentrations as a function of age, whereas the opposite was true for the females.
Spring and stream waters from the San Antonio de los Cobres area in NW Argentina have high concentrations of arsenic (As) (151—9490 μg l-1), of which AsV varies widely (6—~100% of total As). Arsenic concentrations correlate with Na, K, Cl, HCO3, B and Li, which are high in the spring waters and are typical of geothermal areas world-wide. Springs near San Antonio supply large amounts of As to the Rio San Antonio de los Cobres (up to 1180 μg l-1), but these concentrations decline to 400 μg l-1 within 10 km of the spring inputs, due to dilution and mineral precipitation.
Introduction: Trauma leading to uncontrolled hemorrhage of the torso in the critically injured patient can rapidly progress to decreased cerebral and cardiovascular perfusion and carries a significant morbidity and mortality. Given the non-compressible nature and difficult anatomic access of these injuries, obtaining hemostasis is often a challenge and non-surgical options are sparse. Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is a rapidly administered emergency department intervention that allows transient source control of caudal torso hemorrhage while arranging definitive surgical management. Although initially postulated in the 1950s, limited research regarding its therapeutic use in trauma has been available until recently. Here, we present a systematic review of the literature pertaining to the use of REBOA in severe trauma. Methods: An experienced medical librarian searched electronic databases for terms relating to REBOA, aortic balloon occlusion, hemorrhage, trauma and shock. Articles were identified, screened, retrieved and reviewed in accordance with PRISMA systematic review guidelines. English case reports, case series, cohort studies, randomized-controlled trials, systematic reviews and meta-analyses pertaining to the use of REBOA in human trauma patients were included. Customized inclusion and data extraction forms were created and used to form an electronic database of relevant studies. Results: After exclusion of duplicates, 2147 potentially relevant articles were identified and screened by title/abstract and 136 articles meeting inclusion criteria were retrieved for full-text review. Final analysis of 26 articles included 5 case reports, 13 case series, 7 observational cohort studies and 1 systematic review. Data spanning 771 patients undergoing REBOA were collected (weighted average age: 49.5, gender: 67.7% male, injury severity score: 35.1). Where data available, REBOA increased systolic blood pressure by a weighted average of 54.7mmhg and overall survival was 32.6%. Conclusion: Limited evidence pertaining to the use of REBOA in severe trauma exists with the majority of available data coming from individual case studies and case series. By extension, quantitative analysis regarding outcome data of this intervention requires further research in the form of larger studies with subgroup analysis to identify the subset of patients for which REBOA may benefit and to further delineate the risks of implementing this intervention
Quality and safety in healthcare, as an academic discipline, has made significant progress over recent decades, and there is now an active and established community of researchers and practitioners. However, work has predominantly focused on physical health, despite broader controversy regarding the attention paid to, and significance attributed to, mental health. Work from both communities is required in order to ensure that quality and safety is actively embedded within mental health research and practice and that the academic discipline of quality and safety accurately represents the scientific knowledge that has been accumulated within the mental health community.
During the last two decades, vertebrate palaeontological research in Australia has entered a new phase of development, with more investigators backed by a significant increase in financial support from government and private financial sources. The consequences of this accelerated phase of investigation has been rapid growth in information about vertebrate diversity, phylogenetic relationships, biocorrelation, palaeobiogeography and palaeoecology. In this review, we consider highlights of the developing late Mesozoic- late Cenozoic record of Australian terrestrial mammals, in part because the Cenozoic record of these is better known than that for any other group of vertebrates and in part because the ability to infer aspects of palaeohabitats from anatomical features is perhaps greatest for this group.
Most modern orders of mammals underwent adaptive radiations between the Late Cretaceous and late Paleogene subsequent to the Early to mid-Cretaceous diversification of angiosperms. For this reason many aspects of the history and structure of Australia's mammalian herbivores reflect the requirements of harvesting and consuming particular groups of flowering plants. In so far as this correlation holds, it is possible to infer from the structure of the dentition of extinct herbivores aspects of the vegetation upon which they fed. Although experimental studies (e.g. Sanson, 1989) of the function of the teeth of living Australian herbivores are few, deductive analysis of the diets of extinct forms based on diets of living species enables hypotheses about the timing of key mid-late Tertiary changes in the structure of Australia's terrestrial communities.
Higher-level systematic nomenclatures used here follow those of Aplin & Archer (1987; marsupials), Watts & Aslin (1981; rodents) and Walton & Richardson (1989; bats and other mammal groups). Biostratigraphic nomenclature, unless otherwise indicated, follows those of Woodburne et al. (1985) and Archer et al. (1989, 1991). The positions of the major fossil sites discussed in this chapter are shown in Figure 6.1 and the current understanding of the ages of the sites is shown in Figure 6.2.
AUSTRALIAN MAMMAL DIVERSITY
There are 12 groups of ordinally distinct endemic Australian mammals.
Although many researchers, from a number of industries, have studied the aerodynamics of ground effect conditions, published research remains inconclusive. Published results are frequently found to conflict and modeling procedures (in both computational and experimental situations) vary. In this paper, existing research is reviewed and the methods used in obtaining the results are compared. Possible causes for the discrepancies in the published work are outlined, including the inappropriate specifications of boundary conditions and the neglect of viscosity in some computational analyses. Computational and experimental analyses are then performed to determine if these identified areas do cause inconsistencies in results and to also determine accurate simulation procedures.
In moving from the realm of stationary wing flight towards the complexity of flapping wing flight as evolved in birds, we wish to introduce the simplest means of flapping as a first step in an attempt to simplify as much as possible our wind tunnel model and also to confine our attention to the dominant thrust producing mechanism. Our model half wings flap only in the plane normal to flight. The flapping motion is sinusoidal with time and symmetrical about the mid position (Fig. 6). No wing bending was allowed. The wing section shape had no camber and also was rigid in shape but free to twist in torsion about its shear centre. However, the model root support was fixed and therefore could not simulate vertical plunging of a bird associated with ideal elliptic span loading (Ref. 1).
The accurate prediction of ground effect aerodynamics is an important aspect of wing-in-ground effect vehicle (WIG) design. Computational fluid dynamics (CFD) solutions are useful alternatives to expensive (especially in the case of ground effect) wind-tunnel testing. However, the incorporation of the rigid surface effects often leads to confusion due to such a model being in a vehicle fixed reference frame (air moving, vehicle fixed) rather than the real-life situation of a ground fixed reference frame (air fixed, vehicle moving).
Part of Robert T. Leiper's (1881–1969) lasting legacy in medical helminthology is grounded on his pioneering work on schistosomiasis (Bilharzia). Having undertaken many expeditions to the tropics, his fascination with parasite life cycles typically allowed him to devise simple preventive measures that curtailed transmission. Building on his formative work with others in Africa and Asia, and again in Egypt in 1915, he elucidated the life cycles of African schistosomes. His mandate, then commissioned by the British War Office, was to prevent and break transmission of this disease in British troops. This he did by raising standing orders based on simple water hygiene measures. Whilst feasible in military camp settings, today their routine implementation is sadly out of reach for millions of Africans living in poverty. Whilst we celebrate the centenary of Leiper's research we draw attention to some of his lesser known colleagues, then focus on schistosomiasis in Uganda discussing why expanded access to treatment with praziquantel is needed now. Looking to WHO 2020 targets for neglected tropical diseases, we introduce COUNTDOWN, an implementation research consortium funded by DFID, UK, which fosters the scale-up of interventions and confirm the current relevance of Leiper's original research.
Minimum Sample Richness (MSR) is defined as the smallest number of taxa that must be recorded in a sample to achieve a given level of inter-assemblage classification accuracy. MSR is calculated from known or estimated richness and taxonomic similarity. Here we test MSR for strengths and weaknesses by using 167 published mammalian local faunas from the Paleogene and early Neogene of the Quercy and Limagne area (Massif Central, southwestern France), and then apply MSR to 84 Oligo-Miocene faunas from Riversleigh, northwestern Queensland, Australia. In many cases, MSR is able to detect the assemblages in the data set that are potentially too incomplete to be used in a similarity-based comparative taxonomic analysis. The results show that the use of MSR significantly improves the quality of the clustering of fossil assemblages. We conclude that this method can screen sample assemblages that are not representative of their underlying original living communities. Ultimately, it can be used to identify which assemblages require further sampling before being included in a comparative analysis.