786 research outputs found
MASSENAUSGLEICH AM KURBELGETRIEBE VON SECHSZYLINDER-VIERTAKT-V-MOTOREN MIT 6 KURBELN UND 60Ëš ZYLINDERWINKELN
Alpha Cygnids: a possible July minor meteor shower
We present a comprehensive study of a possible -Cygnid meteor shower. Based on visual and telescopic observations made by Polish observers we estimate basic parameters of the stream. Activity of -Cygnids lasts from around June 30 to July 31 with clear maximum near July 16-17 (solar longitude ). Maximal Zenithal Hourly Rates (ZHRs) are equal to . The structure of the radiant analyzed by {\sc radiant} software is most compact for geocentric velocity of the events equal to 41 km/s, and for the drift of the radiant (in units /day) equal to of maximum is .We derive population index equal to from magnitude distribution of 738 possible members of the stream. Comparing the veloctity distributions of 754 possible tests we conclude that both distributions are different with probability very close to 1.0. Telescopic observations strictly confirm the results obtained from visual observations. The smallest values of parameter we obtained for the geocentric velocity equal to 40 km/s and for the drift of the radiant (in units /day) equal to . The center of the radiant for moment of maximum is . In spite of making many photographic exposures we still have no photographic or video confirmation of the existence of this stream
Context awareness computing in smart spaces using stochastic analysis of sensor data
In building a smart space, it becomes more critical to develop a recognition system which enables to be aware of contexts, since the appropriate services can be provided under the accurate recognition. As services satisfying for desires of individual human residents are more demanding, the necessity for more sophisticated recognition algorithms is increasing. This paper proposes an approach to discover the current context by stochastically analyzing data obtained from sensors deployed in the smart space. The approach proceeds in two phases, which is to build context models and to find one context model matching the current state space, however we mainly focus on the phase building context models. Experimental validation supports the approach and approved validity
The reproductive cycle of the thorny skate (Amblyraid radiata) in the western Gulf of Maine
The thorny skate (Amblyraja radiata) is a large species of skate that is endemic to the waters of the western north Atlantic in the Gulf of Maine. Because the biomass of thorny skates has recently declined below threshold levels mandated by the Sustainable Fisheries Act, commercial harvests from this region are prohibited. We have undertaken a comprehensive study to gain insight into the life history of this skate. The present study describes and characterizes the reproductive cycle of female and male thorny skates, based on monthly samples taken off the coast of New Hampshire, from May 2001 to May 2003. Gonadosomatic index (GSI), shell gland weight, follicle size, and egg case formation, were assessed for 48 female skates. In general, these reproductive parameters remained relatively constant throughout most of the year. However, transient but significant increases in shell gland weight and GSI were observed during certain months. Within the cohort of specimens sampled monthly throughout the year, a subset of females always had large preovulatory follicles present in their ovaries. With the exception of June and September specimens, egg cases undergoing various stages of development were observed in the uteri of specimens captured during all other months of the year. For males (n=48), histological stages Ill through VI (SIII-SVI) of spermatogenesis, GSI, and hepatosomatic index (HSI) were examined. Although there appeared to be monthly fluctuations in spermatogenesis, GSI, and HSI, no significant differences were found. The production and maintenance of mature spermatocysts (SVI) within the testes was observed throughout the year. These findings collectively indicate that the thorny skate is reproductively active year round
Optimizing adipogenic transdifferentiation of bovine mesenchymal stem cells: a prominent role of ascorbic acid in FABP4 induction
Adipocyte differentiation of bovine adipose-derived stem cells (ASC) was induced by foetal bovine serum (FBS), biotin, pantothenic acid, insulin, rosiglitazone, dexamethasone and 3-isobutyl-1-methylxanthine, followed by incubation in different media to test the influence of ascorbic acid (AsA), bovine serum lipids (BSL), FBS, glucose and acetic acid on transdifferentiation into functional adipocytes. Moreover, different culture plate coatings (collagen-A, gelatin-A or poly-L-lysine) were tested. The differentiated ASC were subjected to Nile red staining, DAPI staining, immunocytochemistry and quantitative reverse transcription PCR (for NT5E, THY1, ENG, PDGFRα, FABP4, PPARγ, LPL, FAS, GLUT4). Nile red quantification showed a significant increase in the development of lipid droplets in treatments with AsA and BSL without FBS. The presence of BSL induced a prominent increase in FABP4 mRNA abundance and in FABP4 immunofluorescence signals in coincubation with AsA. The abundance of NT5E, ENG and THY1 mRNA decreased or tended to decrease in the absence of FBS, and ENG was additionally suppressed by AsA. DAPI fluorescence was higher in cells cultured in poly-L-lysine or gelatin-A coated wells. In additional experiments, the multi-lineage differentiation potential to osteoblasts was verified in medium containing ß-glycerophosphate, dexamethasone and 1,25-dihydroxyvitamin D3 using alizarin red staining. In conclusion, bovine ASC are capable of multi-lineage differentiation. Poly-L-lysine or gelatin-A coating, the absence of FBS, and the presence of BSL and AsA favour optimal transdifferentiation into adipocytes. AsA supports transdifferentiation via a unique role in FABP4 induction, but this is not linearly related to the primarily BSL-driven lipid accumulation
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