Gene drives and population persistence vs elimination: The impact of spatial structure and inbreeding at low density

Synthetic gene drive constructs are being developed to control disease vectors, invasive species, and other pest species. In a well-mixed random mating population a sufficiently strong gene drive is expected to eliminate a target population, but it is not clear whether the same is true when spatial processes play a role. In species with an appropriate biology it is possible that drive-induced reductions in density might lead to increased inbreeding, reducing the efficacy of drive, eventually leading to suppression rather than elimination, regardless of how strong the drive is. To investigate this question we analyse a series of explicitly solvable stochastic models considering a range of scenarios for the relative timing of mating, reproduction, and dispersal and analyse the impact of two different types of gene drive, a Driving Y chromosome and a homing construct targeting an essential gene. We find in all cases a sufficiently strong Driving Y will go to fixation and the population will be eliminated, except in the one life history scenario (reproduction and mating in patches followed by dispersal) where low density leads to increased inbreeding, in which case the population persists indefinitely, tending to either a stable equilibrium or a limit cycle. These dynamics arise because Driving Y males have reduced mating success, particularly at low densities, due to having fewer sisters to mate with. Increased inbreeding at low densities can also prevent a homing construct from eliminating a population. For both types of drive, if there is strong inbreeding depression, then the population cannot be rescued by inbreeding and it is eliminated. These results highlight the potentially critical role that low-density-induced inbreeding and inbreeding depression (and, by extension, other sources of Allee effects) can have on the eventual impact of a gene drive on a target population

Application of electron multiplying CCD technology in space instrumentation

Electron multiplying CCD (EMCCD) technology has found important initial applications in low light surveillance and photon starved scientific instrumentation. This paper discusses the attributes of the EMCCD which make it useful for certain space instruments, particularly those which are photon starved, and explores likely risks from the radiation expected in such instruments

Bildfolgenanalyse in der Umweltphysik: Wasseroberflächenwellen und Gasaustausch zwischen Atmosphäre und Gewässern

Bildsequenzen von Wasseroberflächenwellen und Grenzschicht werden als neue Anwendung der Bildfolgenanalyse vorgestellt. Die Möglichkeiten der Auswertung mit Hilfe der Fouriertransformation und der Laplace- Pyramide werden diskutiert. Die quantitative Bildanalyse eröffnet weit reichende experimentelle Möglichkeiten für diesen Bereich der Umweltphysik; zugleich können sich aber auch Anstöße für die Weiterentwicklung der Bildfolgenanalyse als Methode ergeben

High Resolution Zero-Shot Domain Adaptation of Synthetically Rendered Face Images

Generating photorealistic images of human faces at scale remains a prohibitively difficult task using computer graphics approaches. This is because these require the simulation of light to be photorealistic, which in turn requires physically accurate modelling of geometry, materials, and light sources, for both the head and the surrounding scene. Non-photorealistic renders however are increasingly easy to produce. In contrast to computer graphics approaches, generative models learned from more readily available 2D image data have been shown to produce samples of human faces that are hard to distinguish from real data. The process of learning usually corresponds to a loss of control over the shape and appearance of the generated images. For instance, even simple disentangling tasks such as modifying the hair independently of the face, which is trivial to accomplish in a computer graphics approach, remains an open research question. In this work, we propose an algorithm that matches a non-photorealistic, synthetically generated image to a latent vector of a pretrained StyleGAN2 model which, in turn, maps the vector to a photorealistic image of a person of the same pose, expression, hair, and lighting. In contrast to most previous work, we require no synthetic training data. To the best of our knowledge, this is the first algorithm of its kind to work at a resolution of 1K and represents a significant leap forward in visual realism

Visual Observation of a Moving Agent

We address the problem of observing a moving agent. In particular, we propose a system for observing a manipulation process, where a robot hand manipulates an object. A discrete event dynamic systems (DEDS) frame work is developed for the hand/object interaction over time and a stabilizing observer is constructed. Low-level modules are developed for recognizing the events that causes state transitions within the dynamic manipulation system. The work examines closely the possibilities for errors, mistakes and uncertainties in the manipulation system, observer construction process and event identification mechanisms. The system utilizes different tracking techniques in order to observe and recognize the task in an active, adaptive and goal-directed manner

The Enhanced Liver Fibrosis test maintains its diagnostic and prognostic performance in alcohol-related liver disease: a cohort study

BACKGROUND: Alcohol is the main cause of chronic liver disease. The Enhanced Liver Fibrosis (ELF) test is a serological biomarker for fibrosis staging in chronic liver disease, however its utility in alcohol-related liver disease warrants further validation. We assessed the diagnostic and prognostic performance of ELF in alcohol-related liver disease. METHODS: Observational cohort study assessing paired ELF and histology from 786 tertiary care patients with chronic liver disease due to alcohol (n = 81) and non-alcohol aetiologies (n = 705). Prognostic data were available for 64 alcohol patients for a median of 6.4 years. Multiple ELF cut-offs were assessed to determine diagnostic utility in moderate fibrosis and cirrhosis. Survival data were assessed to determine the ability of ELF to predict liver related events and all-cause mortality. RESULTS: ELF identified cirrhosis and moderate fibrosis in alcohol-related liver disease independently of aminotransferase levels with areas under receiver operating characteristic curves of 0.895 (95% CI 0.823-0.968) and 0.923 (95% CI 0.866-0.981) respectively, which were non-inferior to non-alcohol aetiologies. The overall performance of ELF was assessed using the Obuchowski method: in alcohol = 0.934 (95% CI 0.908-0.960); non-alcohol = 0.907 (95% CI 0.895-0.919). Using ELF < 9.8 to exclude and ≧ 10.5 to diagnose cirrhosis, 87.7% of alcohol cases could have avoided biopsy, with sensitivity of 91% and specificity of 85%. A one-unit increase in ELF was associated with a 2.6 (95% CI 1.55-4.31, p < 0.001) fold greater odds of cirrhosis at baseline and 2.0-fold greater risk of a liver related event within 6 years (95% CI 1.39-2.99, p < 0.001). CONCLUSIONS: ELF accurately stages liver fibrosis independently of transaminase elevations as a marker of inflammation and has superior prognostic performance to biopsy in alcohol-related liver disease

A survey of sports drinks consumption amongst adolescents

Background Sports drinks intended to improve performance and hydrate athletes taking part in endurance sport are being marketed to children, for whom these products are not intended. Popularity among children has grown exponentially. Worryingly they consume them socially, as well as during physical activity. Sports drinks are high in sugar and are acidic. Product marketing ignores the potential harmful effects of dental caries and erosion. Objective To investigate the use of sports drinks by children. Method One hundred and eighty-three self-complete questionnaires were distributed to four schools in South Wales. Children in high school years 8 and 9 (aged 12–14) were recruited to take part. Questions focused on use of sports drinks, type consumed, frequency of and reason for consumption and where drinks were purchased. Results One hundred and sixty children responded (87% response rate): 89.4% (143) claimed to drink sports drinks, half drinking them at least twice a week. Lucozade Sport™ was the most popular brand. The main reason for consuming the drinks was attributed to the 'nice taste' (90%, 129/143). Most respondents purchased the drinks from local shops (80.4%, 115) or supermarkets (54.5%, 78). More boys claimed to drink sports drinks during physical activity (77.9% versus 48.6% girls, P <0.001). Whereas more girls claimed to drink them socially (51.4% versus 48.5% boys, NS). Conclusion A high proportion of children consumed sports drinks regularly and outside of sporting activity. Dental health professionals should be aware of the popularity of sports drinks with children when giving health education advice or designing health promotion initiatives

The availability of novelty sweets within the high school fringe

Background Reducing sugar consumption is a primary focus of current global public health policy. Achieving 5% of total energy from free sugars will be difficult acknowledging the concentration of free sugars in sugar sweetened beverages, confectionery and as hidden sugars in many savoury items. The expansion of the novelty sweet market in the UK has significant implications for children and young adults as they contribute to dental caries, dental erosion and obesity. Objective To identify the most available types of novelty sweets within the high school fringe in Cardiff, UK and to assess their price range and where and how they were displayed in shops. Subjects and methods Shops within a ten minute walking distance around five purposively selected high schools in the Cardiff aea representing different levels of deprivation were visited. Shops in Cardiff city centre and three supermarkets were also visited to identify the most commonly available novelty sweets. Results The ten most popular novelty sweets identified in these scoping visits were (in descending order): Brain Licker, Push Pop, Juicy Drop, Lickedy Lips, Big Baby Pop, Vimto candy spray, Toxic Waste, Tango candy spray, Brain Blasterz Bitz and Mega Mouth candy spray. Novelty sweets were located on low shelves which were accessible to all age-groups in 73% (14 out of 19) of the shops. Novelty sweets were displayed in the checkout area in 37% (seven out of 19) shops. The price of the top ten novelty sweets ranged from 39p to £1. Conclusion A wide range of acidic and sugary novelty sweets were easily accessible and priced within pocket money range. Those personnel involved in delivering dental and wider health education or health promotion need to be aware of recent developments in children's confectionery. The potential effects of these novelty sweets on both general and dental health require further investigation

Entrepreneurial sons, patriarchy and the Colonels' experiment in Thessaly, rural Greece

Existing studies within the field of institutional entrepreneurship explore how entrepreneurs influence change in economic institutions. This paper turns the attention of scholarly inquiry on the antecedents of deinstitutionalization and more specifically, the influence of entrepreneurship in shaping social institutions such as patriarchy. The paper draws from the findings of ethnographic work in two Greek lowland village communities during the military Dictatorship (1967–1974). Paradoxically this era associated with the spread of mechanization, cheap credit, revaluation of labour and clear means-ends relations, signalled entrepreneurial sons’ individuated dissent and activism who were now able to question the Patriarch’s authority, recognize opportunities and act as unintentional agents of deinstitutionalization. A ‘different’ model of institutional change is presented here, where politics intersects with entrepreneurs, in changing social institutions. This model discusses the external drivers of institutional atrophy and how handling dissensus (and its varieties over historical time) is instrumental in enabling institutional entrepreneurship