Supraglacial debris cover: global distribution, evolution and regional-scale effect on melt

Rock debris on the surface of glaciers form unique structures that evolve with a changing climate and have a net system impact that is unknown at wide scales. While a growing canon of literature is focused on single glaciers or sample regions well-suited to investigate supraglacial debris cover, a knowledge gap remains for the rest of Earth’s glaciers. A global inventory of debris cover was produced using the Randolph Glacier Inventory (RGI) and a set of manually selected Landsat images (n=271) showing that 6.0% of Earth’s mountain glaciers (excluding Greenland and Antarctica) are covered by rock debris. Debris-covered area was defined using a simple spectral band ratio threshold separating optically dark rock debris from optically light ice and snow. To improve the quality of this debris map, and to align mapped debris cover and glacier outlines in time,the RGI was adjusted to match the glacier extent expressed in the set of Landsat images. 2.4% of the RGI (version 6.0) was identified to be falsely classified as glacier area and an area equal to 0.3% of the RGI was identified as area falsely excluded from the inventory. Regional results show that the three most debris abundant regions on Earth, Alaska (11,287 km2), the Himalaya (8,759 km2) and Greenland (3,492 km2) make up 80% of Earth’s supraglacial debris cover (29,248 km2). Broken down further to an individual glacier scale, three new metrics were derived that summarize the state of each glacier’s debris cover. These metrics quantify the stage of a glacier between zero and complete debris coverage within the ablation zone and characterize the configuration of the glacier’s moraine structure and its ability to expand spatially. These metrics enable the placement of each glacier onto a conceptual timeline of debris cover evolution spanning 100s to 1,000s of years. The most advanced stage glaciers present on Earth today are concentrated in the Himalaya, Alaska and New Zealand. Direct measurements to help refine the thermal signal of debris cover in thermal satellite imagery. A time-lapse dataset of sub-debris melt rates coupled with field-based high resolution thermal imagery was used to investigate the coupling between these two quantities and propose a simple method using a time-series of thermistor surface temperature data coupled with a refined thermal satellite image to model sub-debris melt at a regional scale. of debris cover evolution were made on a decadal timescale for 12 sample regions spanning five continents. Results show a global-scale signal of a net increase in debris-covered area that is marked by regions of minor change: the Karakoram Mountains and Central Tian Shan gained debris at a low to near-zero rate of 0.2 and 1.4% decade-1, respectively; and regions of significant change: the Manson Icefield and the Vatnajokull ice cap gained debris at rates of 40.9 and 50.5% decade -1, respectively. Beyond 2-D area changes, small scale processes make up many of the complex nuances of supraglacial debris cover. Ice cliffs are focal points of high melt rates (up to 112% of debris-free glacier melt, measured at Canwell Glacier, Alaska), yet are difficult to map at wide scales due to their relatively small size and steep orientation. A new method to map ice cliffs was developed that automatically selects a location specific surface slope threshold to define ice cliff area. The method was developed in Alaska and tested in Nepal to demonstrate regional transferability. These mapped ice cliffs were then used to help refine the thermal signal of debris cover in thermal satellite imagery. A timelapse dataset of sub-debris melt rates coupled with field-based high resolution thermal imagery was used to investigate the coupling between these two quantities and propose a simple method using a time-series of thermistor surface temperature data coupled with a refined thermal satellite image to model sub-debris melt at a regional-scale

The influence of defined ante-mortem stressors on the early post-mortem biochemical processes in the abdominal muscle of the Norway lobster, Nephrops norvegicus (Linnaeus, 1758)

The effects of four different ante-mortem stressors (exercise, emersion, starvation and a patent infection with the parasite Hematodinium sp.) on post-mortem processes have been investigated in the abdominal muscle of Norway lobster Nephrops norvegicus by measuring changes in the pH, the levels of glycogen, l-lactate, arginine phosphate, ATP, ADP, AMP, IMP, HxR, Hx and the adenylate energy charge (AEC) over a time course of 24 h with samples being taken at 0, 3, 6, 12 and 24 h. The acute stresses of intense exercise and 2 h emersion resulted in a premature onset of anaerobic glycolysis, leading both to an enhanced glycogen depletion rate and an early accumulation of l-lactate. The chronic stressors, starvation and parasite infection, resulted in a complete ante-mortem depletion of muscle glycogen and consequently the failure of post-mortem glycolytic fermentation. Post-mortem pH and ATP inter-conversion were significantly altered in chronically stressed animals. Ante-mortem, a rapid, almost complete depletion of arginine phosphate was observed in all stress groups. The AEC was altered significantly by all stresses, indicating a strong energy demand. The findings suggest that ante-mortem stressors strongly influence the post-mortem biochemical processes. The laboratory-based results are compared to 'field' data and effects on post-harvest product quality are discussed

Designing citizen science tools for learning: lessons learnt from the iterative development of nQuire

This paper reports on a 4-year research and development case study about the design of citizen science tools for inquiry learning. It details the process of iterative pedagogy-led design and evaluation of the nQuire toolkit, a set of web-based and mobile tools scaffolding the creation of online citizen science investigations. The design involved an expert review of inquiry learning and citizen science, combined with user experience studies involving more than 200 users. These have informed a concept that we have termed ‘citizen inquiry’, which engages members of the public alongside scientists in setting up, running, managing or contributing to citizen science projects with a main aim of learning about the scientific method through doing science by interaction with others. A design-based research (DBR) methodology was adopted for the iterative design and evaluation of citizen science tools. DBR was focused on the refinement of a central concept, ‘citizen inquiry’, by exploring how it can be instantiated in educational technologies and interventions. The empirical evaluation and iteration of technologies involved three design experiments with end users, user interviews, and insights from pedagogy and user experience experts. Evidence from the iterative development of nQuire led to the production of a set of interaction design principles that aim to guide the development of online, learning-centred, citizen science projects. Eight design guidelines are proposed: users as producers of knowledge, topics before tools, mobile affordances, scaffolds to the process of scientific inquiry, learning by doing as key message, being part of a community as key message, every visit brings a reward, and value users and their time

Experiences of the Flipped Classroom method Does it make students more motivated?

The aim of this paper is to highlight use of the flipped classroom method, and how teachers perceive this teaching practice. More specific the research focus on whether the teachers’ experience that the model leads to increased motivation in the students learning process. The background for the research is generated from qualitative interviews with teachers, and the empirical data obtained is from semi-structured interviews with these informants. The results show that the flipped classroom method in fact did increase participation and cooperation, which in turn generated motivation and willing students. The teachers got more time for guidance of each student, which provided more solid knowledge on each student’s academic level

Wing pathology of white-nose syndrome in bats suggests life-threatening disruption of physiology

White-nose syndrome (WNS) is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians

Physiological Costs of Repetitive Courtship Displays in Cockroaches Handicap Locomotor Performance

Courtship displays are typically thought to have evolved via female choice, whereby females select mates based on the characteristics of a display that is expected to honestly reflect some aspect of the male’s quality. Honesty is typically enforced by mechanistic costs and constraints that limit the level at which a display can be performed. It is becoming increasingly apparent that these costs may be energetic costs involved in the production of dynamic, often repetitive displays. A female attending to such a display may thus be assessing the physical fitness of a male as an index of his quality. Such assessment would provide information on his current physical quality as well as his ability to carry out other demanding activities, qualities with which a choosy female should want to provision her offspring. In the current study we use courtship interactions in the Cuban burrowing cockroach, Byrsotria fumigata to directly test whether courtship is associated with a signaler’s performance capacity. Males that had produced courtship displays achieved significantly lower speeds and distances in locomotor trials than non-courting control males. We also found that females mated more readily with males that produced a more vigorous display. Thus, males of this species have developed a strategy where they produce a demanding courtship display, while females choose males based on their ability to produce this display. Courtship displays in many taxa often involve dynamic repetitive actions and as such, signals of stamina in courtship may be more widespread than previously thought