84 research outputs found

    Anatomical classification of the shape and topography of the stomach

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    The aim of the study was to present the classification of anatomical variations of the stomach, based on the radiological and historical data. In years 2006–2010, 2,034 examinations of the upper digestive tract were performed. Normal stomach anatomy or different variations of the organ shape and/or topography without any organic radiologically detectable gastric lesions were revealed in 568 and 821 cases, respectively. Five primary groups were established: abnormal position along longitudinal (I) and horizontal axis (II), as well as abnormal shape (III) and stomach connections (IV) or mixed forms (V). The first group contains abnormalities most commonly observed among examined patients such as stomach rotation and translocation to the chest cavity, including sliding, paraesophageal, mixed-form and upside-down hiatal diaphragmatic hernias, as well as short esophagus, and the other diaphragmatic hernias, that were not found in the evaluated population. The second group includes the stomach cascade. The third and fourth groups comprise developmental variations and organ malformations that were not observed in evaluated patients. The last group (V) encloses mixed forms that connect two or more previous variations

    Effects of early starvation periods on zoeal development of brachyuran crabs

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    Larvae of the crabs Menippe mercenaria Say (Menippidae), Panopeus herbstii Milne-Edwards, Neopanope sayi Smith (Xanthidae), Sesarma cinereum Bosc (Grapsidae), and Libinia emerginata Leach (Majidae) were reared in the laboratory. Starvation periods different in length and timing within the first zoeal stage were studied as to their effects on later development and survival rate. After 1-3 days of initial feeding, most larvae had accumulated enough reserves to reach the second stage, independently of further food availability. The development of the survivors was delayed in the following stages, and their later mortality rate was higher than the fed controls. Starvation periods commencing directly after hatching of the larvae exert far stronger negative effects than those beginning later. All observations suggest a particularly sensitive phase in the beginning of larval life in brachyurans. When initial starvation periods exceed the point-of-no-return (PNR), the larvae will die later, even if feeding begins long before the energy reserves are depleted. Temporary lack of suitable prey may be an ecological factor controlling the survival of crab larvae as effectively as physical factors

    Starvation resistence in first stage zoeae of brachyuran crabs in relation to temperature

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    Resistance to starvation in early larval stages of six species of brachyuran crabs representing four families was observed at various constant temperatures. In the optimal temperature range of 25-30°C for these warm temperate crab larvae, survival time of starved zoeae was longer than the development duration time in fed zoeae, while at lower temperatures the relationship of these two duration periods became inversed. This response pattern is found in larvae of the mud crab Rhithropanopeus harrisii and is considered to be typical for warm temperature brachyuran larvae. It indicates that reserved utilization is strongly controlled by temperature, but not to the same degree as development
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