The impact of cave lighting on the bioluminescent display of the Tasmanian glow-worm Arachnocampa tasmaniensis

Bioluminescent larvae of the dipteran genus Arachnocampa are charismatic microfauna that can reach high densities in caves, where they attract many visitors. These focal populations are the subjects of conservation management because of their high natural and commercial value. Despite their tourism importance, little is known about their susceptibility and resilience to natural or human impacts. At Marakoopa Cave in northern Tasmania, guided tours take visitors through different chambers and terminate at a viewing platform where the cave lighting is extinguished and a glowing colony of Arachnocampa tasmaniensis (Diptera: Keroplatidae) larvae on the chamber ceiling is revealed. Research has shown that exposure to artificial light can cause larvae to douse or dim their bioluminescence; hence, the cave lighting associated with visitor access could reduce the intensity of the natural display. We used time-lapse digital photography to record light output over 10 days to determine whether cave lighting affects the intensity or rhythmicity of bioluminescence. Simultaneously, another colony in a different section of the cave, away from tourist activity, was photographed over 3 days. Both colonies showed high-amplitude 24 h cycling of bioluminescence intensity, with the peak occurring at 11.50 h at the unvisited site and 12.50 h at the main chamber, so the time of peak display did not appear to be substantially affected by light exposure. Intermittent light exposure experienced by larvae in the main chamber caused detectable reductions in bioluminescence intensity; however, recovery was rapid and the overall shape of the daily bioluminescence curve closely matched that of the unvisited colony. In conclusion, the artificial light exposure regime used in Marakoopa Cave does not have a substantial effect on the timing or quality of the bioluminescence display. The time-lapse photographic monitoring method could be permanently implemented at focal tourism sites to provide information about daily, seasonal and annual fluctuations in the displays, the response to events such as drought and flood, and the population's ability to recover from adverse conditions

A bimodal spacecraft bus based on a cermet fueled heat pipe reactor

Bimodal space reactor systems provide both thermal propulsion for the spacecraft orbital transfer and electrical power to the spacecraft bus once it is on station. These systems have the potential to increase both the available payload in high energy orbits and the available power to that payload. These increased mass and power capabilities can be used to either reduce mission cost by permitting the use of smaller launch vehicles or to provide increased mission performance from the current launch vehicle. A major barrier to the deployment of these bimodal systems has been the cost associated with their development. This paper describes a bimodal spacecraft bus with performance potential to permit more than 70% of the instrumented payload of the Titan IV/Centaur to be launched from the Atlas IIAS. The development cost is minimized by basing the design on existing component technologies

Close-coupling calculations of low-energy inelastic and elastic processes in 4^4He collisions with H2_2: A comparative study of two potential energy surfaces

The two most recently published potential energy surfaces (PESs) for the HeH$_2$ complex, the so-called MR (Muchnick and Russek) and BMP (Boothroyd, Martin, and Peterson) surfaces, are quantitatively evaluated and compared through the investigation of atom-diatom collision processes. The BMP surface is expected to be an improvement, approaching chemical accuracy, over all conformations of the PES compared to that of the MR surface. We found significant differences in inelastic rovibrational cross sections computed on the two surfaces for processes dominated by large changes in target rotational angular momentum. In particular, the H$_2$($\nu=1, j=0$) total quenching cross section computed using the BMP potential was found to be a factor of $~$1000 larger than that obtained with the MR surface.Comment: 26 pages, 11 figure

Part 2: CT characterisation of pancreatic neoplasm: tumour mimics

There are numerous pancreatic and peripancreatic conditions that can mimic pancreatic neoplasms. Many of these can be confidently diagnosed on computed tomography (CT), while others will require further imaging. Knowledge of these tumour mimics is important to avoid misclassification of benign conditions as malignant and to avoid unnecessary surgery. Mimics can be grouped as parenchymal, vascular, biliary and peripancreatic. These are discussed and illustrated in this review

Charting Evolution’s Trajectory: Using Molluscan Eye Diversity to Understand Parallel and Convergent Evolution

For over 100 years, molluscan eyes have been used as an example of convergent evolution and, more recently, as a textbook example of stepwise evolution of a complex lens eye via natural selection. Yet, little is known about the underlying mechanisms that create the eye and generate different morphologies. Assessing molluscan eye diversity and understanding how this diversity came about will be important to developing meaningful interpretations of evolutionary processes. This paper provides an introduction to the myriad of eye types found in molluscs, focusing on some of the more unusual structures. We discuss how molluscan eyes can be applied to the study of evolution by examining patterns of convergent and parallel evolution and provide several examples, including the putative convergence of the camera-type eyes of cephalopods and vertebrates

Management of trichobezoar: case report and literature review

Trichobezoars (hair ball) are usually located in the stomach, but may extend through the pylorus into the duodenum and small bowel (Rapunzel syndrome). They are almost always associated with trichotillomania and trichophagia or other psychiatric disorders. In the literature several treatment options are proposed, including removal by conventional laparotomy, laparoscopy and endoscopy. We present our experience with four patients and provide a review of the recent literature. According to our experience and in line with the published results, conventional laparotomy is still the treatment of choice. In addition, psychiatric consultation is necessary to prevent relapses

Status of the compactlight design study*

CompactLight (XLS) is an International Collaboration of 24 partners and 5 third parties, funded by the European Union through the Horizon 2020 Research and Innovation Programme. The main goal of the project, which started in January 2018 with a duration of 36 months, is the design of an hard X-ray FEL facility beyond today’s state of the art, using the latest concepts for bright electron photo-injectors, high-gradient accelerating structures, and innovative short-period undulators. The specifications of the facility and the parameters of the future FEL are driven by the demands of potential users and the associated science cases. In this paper we will give an overview on the ongoing activities and the major results achieved until now