A Vision-Based Automatic Safe landing-Site Detection System

An automatic safe landing-site detection system is proposed for aircraft emergency landing, based on visible information acquired by aircraft-mounted cameras. Emergency landing is an unplanned event in response to emergency situations. If, as is unfortunately usually the case, there is no airstrip or airfield that can be reached by the un-powered aircraft, a crash landing or ditching has to be carried out. Identifying a safe landing-site is critical to the survival of passengers and crew. Conventionally, the pilot chooses the landing-site visually by looking at the terrain through the cockpit. The success of this vital decision greatly depends on the external environmental factors that can impair human vision, and on the pilot\u27s flight experience that can vary significantly among pilots. Therefore, we propose a robust, reliable and efficient detection system that is expected to alleviate the negative impact of these factors. In this study, we focus on the detection mechanism of the proposed system and assume that the image enhancement for increased visibility and image stitching for a larger field-of-view have already been performed on terrain images acquired by aircraft-mounted cameras. Specifically, we first propose a hierarchical elastic horizon detection algorithm to identify ground in rile image. Then the terrain image is divided into non-overlapping blocks which are clustered according to a roughness measure. Adjacent smooth blocks are merged to form potential landing-sites whose dimensions are measured with principal component analysis and geometric transformations. If the dimensions of a candidate region exceed the minimum requirement for safe landing, the potential landing-site is considered a safe candidate and highlighted on the human machine interface. At the end, the pilot makes the final decision by confirming one of the candidates, also considering other factors such as wind speed and wind direction, etc

Mapping field photographs to textured surface meshes directly on mobile devices

Funded by Research Council of Norway. Grant Number: 234111/E30Peer reviewedPublisher PD

Divergent sensory and immune gene evolution in sea turtles with contrasting demographic and life histories

Sea turtles represent an ancient lineage of marine vertebrates that evolved from terrestrial ancestors over 100 Mya. The genomic basis of the unique physiological and ecological traits enabling these species to thrive in diverse marine habitats remains largely unknown. Additionally, many populations have drastically declined due to anthropogenic activities over the past two centuries, and their recovery is a high global conservation priority. We generated and analyzed high-quality reference genomes for the leatherback (Dermochelys coriacea) and green (Chelonia mydas) turtles, representing the two extant sea turtle families. These genomes are highly syntenic and homologous, but localized regions of noncollinearity were associated with higher copy numbers of immune, zinc-finger, and olfactory receptor (OR) genes in green turtles, with ORs related to waterborne odorants greatly expanded in green turtles. Our findings suggest that divergent evolution of these key gene families may underlie immunological and sensory adaptations assisting navigation, occupancy of neritic versus pelagic environments, and diet specialization. Reduced collinearity was especially prevalent in microchromosomes, with greater gene content, heterozygosity, and genetic distances between species, supporting their critical role in vertebrate evolutionary adaptation. Finally, diversity and demographic histories starkly contrasted between species, indicating that leatherback turtles have had a low yet stable effective population size, exhibit extremely low diversity compared with other reptiles, and harbor a higher genetic load compared with green turtles, reinforcing concern over their persistence under future climate scenarios. These genomes provide invaluable resources for advancing our understanding of evolution and conservation best practices in an imperiled vertebrate lineage

Zooplankton seasonality at high latitudes: From community to behaviour

This thesis describes the seasonality of the mesozooplankton community in Ramfjord, a shallow high-latitude fjord, in terms of diversity and behavior, using a combination of new and traditional methods. The approach aimed to gain insight into how environmental drivers such as photoperiod and food availability shape seasonal changes in mesozooplankton community structure and Calanus spp. behavior. Seasonal changes in diel vertical migration (DVM) were closely linked to the seasonal changes in day length. Monthly sampling over an entire annual cycle revealed that Ramfjord has particular characteristics such as the dominance of small copepods year-round in terms of abundance and biomass and a population of Calanus finmarchicus that enters a winter resting state rather than a diapause stage. This investigation also used metabarcoding as a quantitative tool for the first time, demonstrating the usefulness of this method in establishing the mesozooplankton community structure. Monthly monitoring of Calanus spp. swimming activity with the locomotor activity method confirmed the efficiency of this method in detecting overwintering in the Calanus population and determined that swimming activity can be used as a proxy for DVM behavior. This thesis demonstrates that the combination of newly developed methods (locomotor activity monitor and metabarcoding as a quantitative tool) with more traditional methods, such as visual identification and active acoustics, can provide new understanding of seasonal changes in the mesozooplankton community structure and behavior

The earliest Europeans – a year in the life: seasonal survival strategies in the Lower Palaeolithic

The Earliest Europeans explores a fundamental question: how did Europe’s first hominin occupants cope with the year-round practical challenges of life. To do so, the book adopts a ‘year in the life’ perspective that draws on the increasingly rich and robust archaeological and Quaternary Science records for the European Lower Palaeolithic, combined with insights from modern ethnography and zoological studies. By exploring potential survival strategies and behaviours, Hosfield offers new insights into the character of Europe’s earliest occupations across more than 1 million years, and ultimately asks: what sorts of ‘humans’ were these hominins? The innovative season-by-season structure of the book explores cyclical fluctuations in resources and weather conditions. From the depths of cold winters to the bountiful foods of late summer, it considers the implications of these variations for hominin behaviours. Hosfield draws on a range of supporting examples and evidence from Lower Palaeolithic sites across Europe, spanning technology, palaeoenvironmental reconstructions, hominin life history, and plant and animal food resources. In doing so, The Earliest Europeans highlights both the current and future potential of Europe’s earliest archaeological record

Standardised methods for collaborative long-term monitoring and management of cetaceans in Wales

Monitoring long terms trends of species abundance is a fundamental requirement for effective conservation. Surveying wildlife creates a baseline to measure changes in the population and to detect and manage specific abiotic and biotic threats. However, long term monitoring is not always effective or achievable because of insufficient finances, resources, planning or limited project focus. Establishing a collaborative network of scientists to bring together similar research may provide the solution as seen with networks on seagrass, aquatic macrophytes and avian populations. Frequently there are many organisations working in isolation using multiple approaches on similar species. This case study specifically investigates the social barriers leading to a lack of collaborative efforts in cetacean monitoring in Wales where there are four organisations independently undertaking systematic long-term monitoring. Here, I produce, trial and analyse a simple low-cost standardised methodology that could be used for long-term monitoring by multiple organisations and review the potential of a collaborative acoustics project to enable simple comparisons of encounter rates for cetaceans Wales-wide. An online questionnaire to stakeholders revealed that primary barriers to collaborative research were personality differences and funding competition; participants indicated that the re-establishment of a marine mammal working group by Natural Resources Wales would enable development of personal relationships and fair access to resources. Similar working groups have been established in terrestrial and aquatic ecology which have attempted to overcome the challenges in effective long-term monitoring. It is anticipated that this research could be duplicated to other species to assess any barriers and solutions to collaborative working and establish more cohesive long-term monitoring strategies in ecology

The Earliest Europeans

The Earliest Europeans explores the early origins of man in Europe through the perspective of ‘a year in the life’: how hominins in the Lower Palaeolithic coped with the year-round practical challenges of mid-latitude Europe with its distinctive temperatures, seasonality patterns, and available resources. Current research has provided increasingly robust archaeological and Quaternary Science records, but there are ongoing uncertainties as to both the earliest Europeans’ specific survival strategies and behaviours, and the character of their dispersals into Europe. In short, how sustained and ‘successful’ were the individual phases of European occupation by Lower Palaeolithic hominins and what sorts of ‘human’ where they

Evolutionary History Of Subterranean Termites In The Geographic And Ecological Context Of The Appalachian Mountains In The United States

Termites in the genus Reticulitermes (Blattodea: Rhinotermitidae) are distributed across the eastern United States, including the southern Appalachian Mountains, a region incredibly rich in biodiversity. The eastern subterranean termite, Reticulitermes flavipes, has been uninentionally introduced to South America and Europe, and is predicted to further expand its geographic range. My goal was to determine how eco-evolutionary processes, operating at both long and short timescales, may have contributed to R. flavipes becoming an invasive species. I examined geographic and environmental influences at historical and contemporary timescales. To do this, I first determined the extent of niche divergence among three geographically overlapping Reticulitermes species, R. flavipes, R. malletei, and R. virginicus, and also identified the geographic areas and environmental conditions in which R. flavipes occurs to the exclusion of the other two species. Then, I assessed evidence for the influence of glacial-interglacial cycles on changes in the geographic distribution of R. flavipes, as well as potential genetic divergence within the species resulting from these past distributional shifts. In addition to historical eco-evolutionary processes, at the contemporary timescale I investigated how epigenetic mechanisms–specifically, DNA methylation–facilitate rapid responses to human-mediated disturbance of forest ecosystems. Finally, I developed a new landscape connectivity metric, MSconn, to help understand the effect spatial heterogeneity of environments plays on biological diversity at multiple levels of organization, from alleles to communities. In principle, MSconn can be integrated into an eco-evolutionary framework, making it possible to quantify the effect of biotic and abiotic environments on gene flow between populations, and vice versa, the effect of gene flow on species interactions within and between communities