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Large Stones (large + stone)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

ALTERNATIVE METHODS IN THE ENDOSCOPIC MANAGEMENT OF DIFFICULT COMMON BILE DUCT STONES

DIGESTIVE ENDOSCOPY, Issue 2010
Dong Ki Lee
The endoscopic method is accepted as a first treatment modality in the management of extrahepatic bile duct. Most large stones can be removed with basket and mechanical lithotripsy after endoscopic sphincterotomy. Currently, in treating large extrahepatic bile duct stones, endoscopic papillary large balloon dilation with mid-incision endoscopic sphincterotomy is actively performed instead of applying mechanical lithotripsy after full endoscopic sphincterotomy. Herein, we describe the conceptions, proper indications, methods and complications of endoscopic papillary large balloon dilation with regards to currently published reports. In addition, intracorporeal lithotripsy by peroral cholangioscopy with an ultra-slim upper endoscope is introduced, which is more convenient than previous conventional intracorporeal lithotripsy methods using mother,baby endoscopy or percutaneous transhepatic cholangioscopy. Lastly, biliary stenting with the choleretic agent administration method is briefly reviewed as an alternative treatment option for frail and elderly patients with large impacted common bile duct stones. [source]

Characteristics and rehabilitation of the spawning habitats of the sea trout, Salmo trutta, in Gotland (Sweden)

FISHERIES MANAGEMENT & ECOLOGY, Issue 1 2004
J.-F. Rubin
Abstract Characteristics of the natural spawning habitat of sea trout, Salmo trutta L., were studied in Själsöån, a small stream of Gotland, Sweden, from 1992 to 1999. Each year, trout spawned on 17 ± 7 different areas (156 places ha,1). Most of the spawning grounds were used every year. Overcutting was evident for at least 60% of the spawning grounds. Fish spawned on a gravel of 19 ± 7 mm in diameter. From 1978 to 1992, 242 artificial spawning grounds were constructed by the Gotland Sport Fishermen Association in four Gotland streams. A sediment trap was dug upstream to the spawning grounds. The artificial spawning ground comprised of a downstream V-shape stream deflector of large stones with a log weir at the narrowest point of the deflector. Upstream of the dam, 15,60 mm diameter gravel was deposited to constitute the spawning ground substratum. To keep the installation efficient, maintenance is needed every year before the spawning season. [source]

Herbivory in an acid stream

FRESHWATER BIOLOGY, Issue 4 2000
Mark E. Ledger
Summary 1Spatial and temporal variation in the distribution and feeding of non-predatory macroinvertebrates was investigated in a first-order, acid stream in the Ashdown Forest, southern England. 2Stonefly (Nemouridae) and chironomid (Orthocladiinae) larvae were abundant on the upper surfaces of mineral substrata of three sizes (small stones, large stones, bedrock). The density of larvae in each taxonomic group did not vary among substrata of different sizes, although strong seasonal variation existed. 3Nemourids and chironomids (H. marcidus) collected from the upper surfaces of substrata exhibited generalist feeding habits, consuming algae (diatoms, coccoid and filamentous green algae), detritus (biofilm matrix material and fine particulate organic matter (FPOM)) and inorganic debris. 4There was spatial variation in the gut contents of nemourids. The proportion of algae in the guts of larvae often increased with the size of the substratum from which they were collected. Strong temporal variation in the composition of the diet also existed. Nemourids ingested a large quantity of attached algae and biofilm matrix from the biofilm in spring and winter, but consumed loose FPOM and associated microflora in summer and autumn. 5We conclude that, in this acid stream, the trophic linkage between algae and grazers is maintained by ,detritivorous' stonefly and chironomid species. The relationship between the feeding habits of these larvae and other life-history attributes, such as mouthpart morphology and mobility, is discussed. [source]

Kinematics and energetics of nut-cracking in wild capuchin monkeys (Cebus libidinosus) in Piauí, Brazil

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009
Q. Liu
Abstract Wild bearded capuchins (Cebus libidinosus, quadrupedal, medium-sized monkeys) crack nuts using large stones. We examined the kinematics and energetics of the nut-cracking action of two adult males and two adult females. From a bipedal stance, the monkeys raised a heavy hammer stone (1.46 and 1.32 kg, from 33 to 77% of their body weight) to an average height of 0.33 m, 60% of body length. Then, they rapidly lowered the stone by flexing the lower extremities and the trunk until the stone contacted the nut. A hit consisting of an upward phase and a downward phase averaged 0.74 s in duration. The upward phase lasted 69% of hit duration. All subjects added discernable energy to the stone in the downward phase. The monkeys exhibited individualized kinematic strategies, similar to those of human weight lifters. Capuchins illustrate that human-like bipedal stance and large body size are unnecessary to break tough objects from a bipedal position. The phenomenon of bipedal nut-cracking by capuchins provides a new comparative reference point for discussions of percussive tool use and bipedality in primates. Am J Phys Anthropol 2009. © 2008 Wiley-Liss, Inc. [source]