Comparison of nonrigid and semirigid airships

One of the main subjects of airship science consists in establishing cooperation between two vertical forces, the buoyancy of the air and the attraction of gravity. The mechanism for establishing this cooperation must have the minimum weight and offer the minimum head resistance. Starting with this principle, let us consider what improvements can be made in the present type of non-rigid airships

Behavioral responses of wild rodents to owl calls in an austral temperate forest

Ecologically based rodent management strategies are arising as a sustainable approach to rodent control, allowing us to preserve biodiversity while safeguarding human economic activities. Despite predator signals being known to generally repel rodents, few field-based studies have compared the behavioral effects of several predators on different prey species, especially in Neotropical ecosystems. Here, we used camera traps to study the behavior of rodent species native to the Chilean temperate forest (Abrothrix spp., long-tailed pygmy rice rat Oligoryzomys longicaudatus) and an introduced rodent (black rat Rattus rattus). Using playbacks of raptor calls, we experimentally exposed rodents to three predation risk treatments: austral pygmy owl calls (Glaucidium nana), rufous-legged owl calls (Strix rufipes) and a control treatment (absence of owl calls). We evaluated the effects of the treatments on the time allocated to three behaviors: feeding time, locomotor activity and vigilance. Moonlight and vegetation cover were also considered in the analyses, as they can modify perceived predation risk. Results showed that predator calls and environmental factors modified prey behavior depending not only on the predator species, but also on the rodent species. Consequently, owl playbacks could be regarded as a promising rodent control tool, knowing that future studies would be critical to deeply understand differences between species in order to select the most effective predator cues

Mobilities, Entanglements, Transformations. Outline of a Research Project on Pottery Practices in Neolithic Wetland Sites of the Swiss Plateau

A large number of later Neolithic sites (3900–3500BC) in Switzerland, Southern Germany and Eastern France offer outstandingly well preserved archaeological materials from cultural layers. Due to the wide use of dendrochronology, settlement remains and artefact assemblages can now be placed into a precise and fixed chronological framework, thus presenting a unique case within prehistoric archaeology. In earlier research, chronological and regional units were constructed on the basis of pottery. These spacial and temporal units of typical pottery sets were understood as Neolithic cultures, as culturally more or less homogenous entities connected with (ethnic) identities. Today, with a larger data corpus of excavated settlements at hand, we can begin to understand that this period of the past was in fact characterised by a multitude of cultural entanglements and transformations. This is indicated by the occurrence of local and non-local pottery styles in one and the same settlement: for example typically local Cortaillod pottery is found together with NMB-styled pottery in settlements at Lake Neuchâtel or Michelsberg pottery is regularly occurring in settlements at Lake Constance where Pfyn pottery style is the typical local one. These and many more examples show that there must have been complex entanglements of social ties expanding between Eastern France, Southern Germany and the Swiss Plateau. Given these circumstances the former notions of Neolithic culture should be critically revised. Therefore, in late 2014, the Prehistoric Archaeology Department at the Archaeological Institute of University of Berne started a four-year research project funded by Swiss National Science Foundation in late 2014: ‘Mobilities, Entanglements and Transformations in Neolithic Societies of the Swiss Plateau (3900-3500 BC)’. It’s objective is to address the topic sketched above by adopting a mixed methods research (MMR)-design combining qualitative and quantitative approaches from archaeology and archaeometry. The approach is theoretically based on Pierre Bourdieu’s reflexive sociology and his concept of habitus but includes further concepts of practice theories. By shifting the focus to the movement of people, ideas and things – to pottery production practices in contexts of mobility – a deeper understanding of the transformative capacities of encounters can be achieved. This opens the path for new insights of Neolithic societies including social, cultural and economic dynamics that were underestimated in former research

Linking Neolithic lakeshore settlements through raw material of siliceous artefacts

This paper presents the results of the provenience analysis of siliceous artefacts from Neolithic lakeshore settlements studied in the scope of the SNSF-project MET (“Mobilities, entanglements and transformations in Neolithic societies on the Swiss Plateau (3900-3500 BCE) supported by the Swiss National Science Foundation (Project No 100011 156205). The aim of this paper is to compare the cultural entanglements as defined by the pottery studies with the regions of origins of the knappable siliceous sedimentary rocks (KSSR) raw materials. The analysed siliceous artefacts were found in cultural layers of wetland settlements in the Northern Alpine Foreland, most of which are dated dendrochronologically with extreme precision. The sources of the raw materials were determined by the identification of the sedimentary microfacies of the siliceous artefacts, which allows the accurate location of the exploited outcrops without destroying the artefacts. This enabled detailed insights into complex entanglements, ties and mobility patterns in the raw material procurement between settlement communities on the Swiss Plateau, southern Germany and eastern France. Furthermore, these results were compared visually with stylistic entanglements in the pottery of the 4th millennium BCE. As a first attempt in this direction, this paper shows the potential of studies on mobility patterns when different find categories are studied in combination regarding their raw materials but also their typology

Tension Pneumothorax after Endoscopic Retrograde Pancreatocholangiogram

We report a case of tension pneumothorax after an endoscopic sphincterotomy. A 78-yr-old woman presented with progressing dyspnea. She had undergone an endoscopic retrograde cholangiopancreatogram three days before due to acute cholecystitis. She underwent endoscopic sphincterotomy for stone extraction, but the procedure failed. On arrival to our hospital, she complained about severe dyspnea and she had subcutaneous emphysema. A computed tomogram scan revealed severe subcutaneous emphysema, right-side tension pneumothorax, and pneumoretroperitoneum. Contrast media injected through a transnasal biliary drainage catheter spilled from the second portion of the duodenum. A second abdominal computed tomogram showed multiple air densities in the retroperitoneum and peritoneal cavity, which were consistent with panperitonitis. We recommended an emergent laparotomic exploration, but the patient's guardians refused. She died eventually due to septic shock. Endoscopic retrograde cholangiopancreatogram is a popular procedure for biliary and pancreatic diseases, but it can cause severe complications such as intestinal perforation. Besides perforations, air can spread through the abdominal cavity, retroperitoneum, mediastinum, and the neck soft tissue, eventually causing pneumothorax. Early recognition and appropriate management is crucial to an optimal output of gastrointestinal perforation and pneumothorax

Liver Parenchyma Perforation following Endoscopic Retrograde Cholangiopancreatography

Although endoscopic retrograde cholangiopancreatography (ERCP) is an effective modality for the diagnosis and treatment of biliary and pancreatic diseases, it is still related with several severe complications. We report on the case of a female patient who developed liver parenchyma perforation following ERCP. She underwent ERCP with sphincterotomy and extraction of a common bile duct stone. Shortly after ERCP, abdominal distension was identified. Abdominal computed tomography revealed intraabdominal air leakage and leakage of contrast dye penetrating the liver parenchyma into the space around the spleen. Since periampullary perforation related to sphincterotomy could not be denied, she was referred for immediate surgery. Obvious perforation could not be found at surgery. Cholecystectomy, insertion of a T tube into the common bile duct, placement of a duodenostomy tube and drainage of the retroperitoneum were performed. She did well postoperatively and was discharged home on postoperative day 28. In conclusion, as it is well recognized that perforation is one of the most serious complication related to ERCP, liver parenchyma perforation should be suspected as a cause

Triple-Tube-Ostomy: A Novel Technique for the Surgical Treatment of Iatrogenic Duodenal Perforation

Although duodenal perforation is currently an infrequent complication of medical procedures, its incidence in the future predictably will increase as endoscopic treatment of duodenal neoplasms becomes more frequently used. In some cases, duodenal perforation is difficult to treat even surgically. We report here a novel technique called ‘triple-tube-ostomy’ for the treatment of iatrogenic duodenal perforation. Since November 2009, there have been three cases of iatrogenic perforation of the duodenum, due to various causes, which we have treated with our novel technique. The main principles of the technique are biliary diversion, decompression of the duodenum, and early enteral nutrition. All patients who underwent the triple-tube-ostomy procedure had good postoperative courses, with few complications. The novel surgical technique we describe in this report is safe, reliable, easy to learn and perform, and led to a good postoperative course in all cases where we performed it