High Reynolds Number Test of the Boeing TR77 Airfoil in the Langley 0.3-Meter Transonic Cryogenic Tunnel

A Boeing TR77 airfoil associated with the Advanced Technology Airfoil Test (ATAT) program was tested in the Langley 0.3 m Transonic Cryogenic Tunnel. Limited analysis of the data indicated that increasing Reynolds number for a fixed Mach number resulted in increased normal-force, nose-down pitching moment, and decreased drag coefficient. Increasing Mach number while keeping the Reynolds number constant yielded the expected increase in normal-force slopes, nose-down pitching moment coefficients, and decrease in angle of attack associated with maximum normal-force coefficient. Turbulent boundary layer flow was achieved over the airfoil at low Reynolds numbers for the test Mach number range using aluminum discs

A copula model of wind turbine performance

The conventional means of assessing the performance of a wind turbine is through consideration of its power curve which provides the relationship between power output and measured wind speed. In this paper it is shown how the joint probability distribution of power and wind speed can be learned from data, rather than from examination of the implied function of the two variables. Such an approach incorporates measures of uncertainty into performance estimates, allows inter-plant performance comparison, and could be used to simulate plant operation via sampling. A preliminary model is formulated and fitted to operational data as an illustration

The impact of policing and homelessness on violence experienced by women who sell sex in London: a modelling study

Street-based sex workers experience considerable homelessness, drug use and police enforcement, making them vulnerable to violence from clients and other perpetrators. We used a deterministic compartmental model of street-based sex workers in London to estimate whether displacement by police and unstable housing/homelessness increases client violence. The model was parameterized and calibrated using data from a cohort study of sex workers, to the baseline percentage homeless (64%), experiencing recent client violence (72%), or recent displacement (78%), and the odds ratios of experiencing violence if homeless (1.97, 95% confidence interval 0.88-4.43) or displaced (4.79, 1.99-12.11), or of experiencing displacement if homeless (3.60, 1.59-8.17). Ending homelessness and police displacement reduces violence by 67% (95% credible interval 53-81%). The effects are non-linear; halving the rate of policing or becoming homeless reduces violence by 5.7% (3.5-10.3%) or 6.7% (3.7-10.2%), respectively. Modelled interventions have small impact with violence reducing by: 5.1% (2.1-11.4%) if the rate of becoming housed increases from 1.4 to 3.2 per person-year (Housing First initiative); 3.9% (2.4-6.9%) if the rate of policing reduces by 39% (level if recent increases had not occurred); and 10.2% (5.9-19.6%) in combination. Violence reduces by 26.5% (22.6-28.2%) if half of housed sex workers transition to indoor sex work. If homelessness decreased and policing increased as occurred during the COVID-19 pandemic in 2020, the impact on violence is negligible, decreasing by 0.7% (8.7% decrease-4.1% increase). Increasing housing and reducing policing among street-based sex workers could substantially reduce violence, but large changes are needed. [Abstract copyright: © 2024. The Author(s).

The racist bodily imaginary: the image of the body-in-pieces in (post)apartheid culture

This paper outlines a reoccurring motif within the racist imaginary of (post)apartheid culture: the black body-in-pieces. This disturbing visual idiom is approached from three conceptual perspectives. By linking ideas prevalent in Frantz Fanon’s description of colonial racism with psychoanalytic concepts such as Lacan’s notion of the corps morcelé, the paper offers, firstly, an account of the black body-in-pieces as fantasmatic preoccupation of the (post)apartheid imaginary. The role of such images is approached, secondly, through the lens of affect theory which eschews a representational ‘reading’ of such images in favour of attention to their asignifying intensities and the role they play in effectively constituting such bodies. Lastly, Judith Butler’s discussion of war photography and the conditions of grievability introduces an ethical dimension to the discussion and helps draw attention to the unsavory relations of enjoyment occasioned by such images

Developing and enhancing biodiversity monitoring programmes: a collaborative assessment of priorities

1.Biodiversity is changing at unprecedented rates, and it is increasingly important that these changes are quantified through monitoring programmes. Previous recommendations for developing or enhancing these programmes focus either on the end goals, that is the intended use of the data, or on how these goals are achieved, for example through volunteer involvement in citizen science, but not both. These recommendations are rarely prioritized. 2.We used a collaborative approach, involving 52 experts in biodiversity monitoring in the UK, to develop a list of attributes of relevance to any biodiversity monitoring programme and to order these attributes by their priority. We also ranked the attributes according to their importance in monitoring biodiversity in the UK. Experts involved included data users, funders, programme organizers and participants in data collection. They covered expertise in a wide range of taxa. 3.We developed a final list of 25 attributes of biodiversity monitoring schemes, ordered from the most elemental (those essential for monitoring schemes; e.g. articulate the objectives and gain sufficient participants) to the most aspirational (e.g. electronic data capture in the field, reporting change annually). This ordered list is a practical framework which can be used to support the development of monitoring programmes. 4.People's ranking of attributes revealed a difference between those who considered attributes with benefits to end users to be most important (e.g. people from governmental organizations) and those who considered attributes with greatest benefit to participants to be most important (e.g. people involved with volunteer biological recording schemes). This reveals a distinction between focussing on aims and the pragmatism in achieving those aims. 5.Synthesis and applications. The ordered list of attributes developed in this study will assist in prioritizing resources to develop biodiversity monitoring programmes (including citizen science). The potential conflict between end users of data and participants in data collection that we discovered should be addressed by involving the diversity of stakeholders at all stages of programme development. This will maximize the chance of successfully achieving the goals of biodiversity monitoring programmes

Whole-Retina Reduced Electrophysiological Activity in Mice Bearing Retina-Specific Deletion of Vesicular Acetylcholine Transporter

Background: Despite rigorous characterization of the role of acetylcholine in retinal development, long-term effects of its absence as a neurotransmitter are unknown. One of the unanswered questions is how acetylcholine contributes to the functional capacity of mature retinal circuits. The current study investigates the effects of disrupting cholinergic signalling in mice, through deletion of vesicular acetylcholine transporter (VAChT) in the developing retina, pigmented epithelium, optic nerve and optic stalk, on electrophysiology and structure of the mature retina. Methods & Results A combination of electroretinography, optical coherence tomography imaging and histological evaluation assessed retinal integrity in mice bearing retina-targeted (embryonic day 12.5) deletion of VAChT (VAChT(Six3-Cre-flox/flox)) and littermate controls at 5 and 12 months of age. VAChT(Six3-Cre-flox/flox) mice did not show any gross changes in nuclear layer cellularity or synaptic layer thickness. However, VAChT(Six3-Cre-flox/flox) mice showed reduced electrophysiological response of the retina to light stimulus under scotopic conditions at 5 and 12 months of age, including reduced a-wave, b-wave, and oscillatory potential (OP) amplitudes and decreased OP peak power and total energy. Reduced a-wave amplitude was proportional to the reduction in b-wave amplitude and not associated with altered a-wave 10%-90% rise time or inner and outer segment thicknesses. Significance This study used a novel genetic model in the first examination of function and structure of the mature mouse retina with disruption of cholinergic signalling. Reduced amplitude across the electroretinogram wave form does not suggest dysfunction in specific retinal cell types and could reflect underlying changes in the retinal and/or extraretinal microenvironment. Our findings suggest that release of acetylcholine by VAChT is essential for the normal electrophysiological response of the mature mouse retina

Colouration in amphibians as a reflection of nutritional status : the case of tree frogs in Costa Rica

Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals

Breathing dynamics of symmetry-broken temporal cavity solitons in Kerr ring resonators

We investigate theoretically and experimentally the instabilities of symmetry-broken, vectorial, bright cavity solitons (CSs) of two-mode nonlinear passive Kerr resonators. Through comprehensive theoretical analyses of coupled Lugiato–Lefever equations, we identify two different breathing regimes where the two components of the vectorial CSs breathe respectively in-phase and out-of-phase. Moreover, we find that deep out-of-phase breathing can lead to intermittent self-switching of the two components, spontaneously transforming a soliton into its mirror-symmetric state. In this process, solitons are also sometimes observed to decay. All our theoretical predictions are confirmed in experiments performed in an optical fiber ring resonator, where CS symmetry breaking occurs across the polarization modes of the resonator. To the best of our knowledge, our study constitutes the first experimental report of breathing instabilities of multi-component optical solitons of driven nonlinear resonators

Exercise interveNtion outdoor proJect in the cOmmunitY for older people - The ENJOY Senior Exercise Park project translation research protocol

Background: Creating inclusive and accessible outdoor environments that provide and encourage opportunities for older adults to engage in physical activity and social interaction is important for healthy ageing. The Senior Exercise Park is outdoor exercise equipment designed specifically for use by older people that provides physical and social benefits for older people in the community, and has the potential to be used widely as a sustainable mode of physical activity. The aim of this study is to implement and evaluate the effects of sustained engagement through the use of a community-based novel outdoor physical activity program (purpose-built exercise park) for older people on physical, mental and social health and physical activity outcomes (the ENJOY project). Methods: This is a prospective pre-post design study with 12 months follow up. Adults aged ≥60 years will be recruited from the general community from the suburbs close to the Senior Exercise Parks locations in Melbourne. Participants will undergo a 12 week structured supervised physical activity program using the outdoor Senior Exercise Park equipment followed by 6 months unstructured physical activity program. Participants will be assessed at baseline, 3, 9, and 12 months. The following outcomes will be assessed: physical activity, physical function, psychosocial and mental health outcomes, falls risk and falls occurrence, participants' feedback and satisfaction, and health care resource use. Discussion: The ENJOY trial is designed to operate in a community setting with local government engagement to maximise the usage of the exercise park and provide an outdoor space for older people to be physically active. This project will evaluate the effectiveness and sustainability of the outdoor exercise park on a range of health outcomes and its long-term usability in the community. Trial registration: This trial is prospectively registered with the Australian New Zealand Clinical Trials Registry. Trial registration number ACTRN12618001727235 registered 18th of October 2018

Observations of Energetic-particle Population Enhancements along Intermittent Structures near the Sun from the Parker Solar Probe

Observations at 1 au have confirmed that enhancements in measured energetic-particle (EP) fluxes are statistically associated with "rough" magnetic fields, i.e., fields with atypically large spatial derivatives or increments, as measured by the Partial Variance of Increments (PVI) method. One way to interpret this observation is as an association of the EPs with trapping or channeling within magnetic flux tubes, possibly near their boundaries. However, it remains unclear whether this association is a transport or local effect; i.e., the particles might have been energized at a distant location, perhaps by shocks or reconnection, or they might experience local energization or re-acceleration. The Parker Solar Probe (PSP), even in its first two orbits, offers a unique opportunity to study this statistical correlation closer to the corona. As a first step, we analyze the separate correlation properties of the EPs measured by the Integrated Science Investigation of the Sun (IS⊙IS) instruments during the first solar encounter. The distribution of time intervals between a specific type of event, i.e., the waiting time, can indicate the nature of the underlying process. We find that the IS⊙IS observations show a power-law distribution of waiting times, indicating a correlated (non-Poisson) distribution. Analysis of low-energy (~15 – 200 keV/nuc) IS⊙IS data suggests that the results are consistent with the 1 au studies, although we find hints of some unexpected behavior. A more complete understanding of these statistical distributions will provide valuable insights into the origin and propagation of solar EPs, a picture that should become clear with future PSP orbits