This study aimed to develop a predictive model utilizing available data to forecast the risk of future shark attacks, making this critical information accessible for everyday public use. Employing a deep learning/neur...This study aimed to develop a predictive model utilizing available data to forecast the risk of future shark attacks, making this critical information accessible for everyday public use. Employing a deep learning/neural network methodology, the system was designed to produce a binary output that is subsequently classified into categories of low, medium, or high risk. A significant challenge encountered during the study was the identification and procurement of appropriate historical and forecasted marine weather data, which is integral to the model’s accuracy. Despite these challenges, the results of the study were startlingly optimistic, showcasing the model’s ability to predict with impressive accuracy. In conclusion, the developed forecasting tool not only offers promise in its immediate application but also sets a robust precedent for the adoption and adaptation of similar predictive systems in various analogous use cases in the marine environment and beyond.展开更多
Aim To purify hepatocyte regeneration stimulatory factor from shark liver and research its molecular feature and activity. Methods and Results Hepatocyte regeneration stimulatory factor (sHRSF) was isolated from hea...Aim To purify hepatocyte regeneration stimulatory factor from shark liver and research its molecular feature and activity. Methods and Results Hepatocyte regeneration stimulatory factor (sHRSF) was isolated from healthy shark livers and separated by homogenization, freezing melting, heat treating, centrifugation, and ultrafiltration. HRSF activity was found mainly in the subfraction of molecular weight less than 30 000 daltons. This crude ultrafiltrate was further purified successively by DEAE Sepharose fast flow chromatography, FPLC Resource 30Q, Resource Q and Mono Q chromatography. A single band was displayed on sodium dodecyl sulfate polyacrylamide gel electrophoresis, which corresponds to molecular weight of 14 600 daltons. The characteristic absorption was obtained at the wavelength 276 nm. The isoelectric point was about 5 1. It contained 18 amino acids and the 15 N terminal amino acid residues were LVGPIGAVGPAGKDG. It had a significant activity in stimulating liver to regenerate. Conclusion We obtained an unknown new active protein, that is hepatocyte regeneration stimulatory factor from shark liver (sHRSF).展开更多
Five unprovoked shark attacks are reported from Sharm-El-Sheikh, Egypt, between 30 November and 5 December 2010. Three of the five attacks are attributed to an oceanic whitetip shark, Carcharinus longimanus with a dis...Five unprovoked shark attacks are reported from Sharm-El-Sheikh, Egypt, between 30 November and 5 December 2010. Three of the five attacks are attributed to an oceanic whitetip shark, Carcharinus longimanus with a distinctive crescent-shaped notch in the upper lobe of the caudal fin. The shark was observed during the first attack on a snorkeler and photographed underwater during the second shark attack on a swimmer. In a video taken several months prior to the attacks, the same shark is hand-fed underwater by a divemaster with additional fish in a pack over his buttock. The shark can be seen swimming behind the divemaster while he removed additional fish from this pack. In Victims 1, 2 and 5, the shark removed an extensive amount of tissue from the victims’ buttock. The three victims also lost a hand and/or a portion of their forearm, suggesting the injuries were inflicted by a shark conditioned to associating food with hand-feedings and the human form. The remaining two attacks, Cases 3 and 4, were attributable to the shortfin mako shark, Isurus oxyrinchus. This was determined from a unique dental pattern of the right side of the upper jaw due to a prior injury. This same “misalignment” dental pattern was observed in the injuries sustained by Victims 3 and 4. We conclude that the shortfin mako shark was responsible for the attacks on Victims 3 and 4, and the oceanic whitetip shark was the causal species of attacks on Victims 1, 2, and 5.展开更多
As apex predators, sharks are of ecological and conservation importance in marine ecosystems. In this study, trophic positions of sharks were estimated using stable isotope ratios of carbon and nitrogen for five repre...As apex predators, sharks are of ecological and conservation importance in marine ecosystems. In this study, trophic positions of sharks were estimated using stable isotope ratios of carbon and nitrogen for five representative species caught by the Chinese longline fleet in the mid-east Pacific, i.e., the blue shark （Prionace glauca）, the bigeye thresher shark （Alopias superciliosus）, the silky shark （Carcharhinus falciformis）, the scalloped hammerhead （Sphyrna lewini）, and the oceanic whitetip shark （Car-charhinus longimanus）. Of these species, oceanic whitetip shark has the lowest trophic level and mean 815N value （3.9 and 14.93%o± 0.84%o）, whereas bigeye thresher shark has the highest level/values （4.5 and 17.02%o±1.21%o, respectively）. The bigeye thresher shark has significantly higher 515N value than other shark species, indicating its higher trophic position. The blue shark and oceanic whitetip shark has significantly higher 813C values than bigeye thresher shark, silky shark and scalloped hammerhead, possibly due to different diets and/or living habitats. The stable isotope data and stomach content data are highly consistent, suggesting that sta-ble isotope analysis supplements traditional feeding ecology study of sharks, and thus contributes to understanding their trophic linkage.展开更多
文摘This study aimed to develop a predictive model utilizing available data to forecast the risk of future shark attacks, making this critical information accessible for everyday public use. Employing a deep learning/neural network methodology, the system was designed to produce a binary output that is subsequently classified into categories of low, medium, or high risk. A significant challenge encountered during the study was the identification and procurement of appropriate historical and forecasted marine weather data, which is integral to the model’s accuracy. Despite these challenges, the results of the study were startlingly optimistic, showcasing the model’s ability to predict with impressive accuracy. In conclusion, the developed forecasting tool not only offers promise in its immediate application but also sets a robust precedent for the adoption and adaptation of similar predictive systems in various analogous use cases in the marine environment and beyond.
基金NationalMarine863Project (No .2 0 0 1AA62 40 90),NationalNaturalScienceFoundationofChina (No .3 0 17110 3 )
文摘Aim To purify hepatocyte regeneration stimulatory factor from shark liver and research its molecular feature and activity. Methods and Results Hepatocyte regeneration stimulatory factor (sHRSF) was isolated from healthy shark livers and separated by homogenization, freezing melting, heat treating, centrifugation, and ultrafiltration. HRSF activity was found mainly in the subfraction of molecular weight less than 30 000 daltons. This crude ultrafiltrate was further purified successively by DEAE Sepharose fast flow chromatography, FPLC Resource 30Q, Resource Q and Mono Q chromatography. A single band was displayed on sodium dodecyl sulfate polyacrylamide gel electrophoresis, which corresponds to molecular weight of 14 600 daltons. The characteristic absorption was obtained at the wavelength 276 nm. The isoelectric point was about 5 1. It contained 18 amino acids and the 15 N terminal amino acid residues were LVGPIGAVGPAGKDG. It had a significant activity in stimulating liver to regenerate. Conclusion We obtained an unknown new active protein, that is hepatocyte regeneration stimulatory factor from shark liver (sHRSF).
文摘Five unprovoked shark attacks are reported from Sharm-El-Sheikh, Egypt, between 30 November and 5 December 2010. Three of the five attacks are attributed to an oceanic whitetip shark, Carcharinus longimanus with a distinctive crescent-shaped notch in the upper lobe of the caudal fin. The shark was observed during the first attack on a snorkeler and photographed underwater during the second shark attack on a swimmer. In a video taken several months prior to the attacks, the same shark is hand-fed underwater by a divemaster with additional fish in a pack over his buttock. The shark can be seen swimming behind the divemaster while he removed additional fish from this pack. In Victims 1, 2 and 5, the shark removed an extensive amount of tissue from the victims’ buttock. The three victims also lost a hand and/or a portion of their forearm, suggesting the injuries were inflicted by a shark conditioned to associating food with hand-feedings and the human form. The remaining two attacks, Cases 3 and 4, were attributable to the shortfin mako shark, Isurus oxyrinchus. This was determined from a unique dental pattern of the right side of the upper jaw due to a prior injury. This same “misalignment” dental pattern was observed in the injuries sustained by Victims 3 and 4. We conclude that the shortfin mako shark was responsible for the attacks on Victims 3 and 4, and the oceanic whitetip shark was the causal species of attacks on Victims 1, 2, and 5.
基金Li Yunkai was supported by the National Natural Science Foundation of China (No.41206124)Ph.D.Programs Foundation of Ministry of Education of China (No.201 23104120001)+3 种基金the ‘Chen Guang’ Project of Shanghai Municipal Education Commission (No.D8004-10-0206)the Shanghai Education Development Foundation (No.B-8102-10-0084)Zhu Jiangfeng and Dai Xiaojie were supported by the National Natural Science Foundation of China (No.41106118)the Scientific Observing and Experimental Station of Oceanic Fishery Resources, Ministry of Agriculture, China
文摘As apex predators, sharks are of ecological and conservation importance in marine ecosystems. In this study, trophic positions of sharks were estimated using stable isotope ratios of carbon and nitrogen for five representative species caught by the Chinese longline fleet in the mid-east Pacific, i.e., the blue shark （Prionace glauca）, the bigeye thresher shark （Alopias superciliosus）, the silky shark （Carcharhinus falciformis）, the scalloped hammerhead （Sphyrna lewini）, and the oceanic whitetip shark （Car-charhinus longimanus）. Of these species, oceanic whitetip shark has the lowest trophic level and mean 815N value （3.9 and 14.93%o± 0.84%o）, whereas bigeye thresher shark has the highest level/values （4.5 and 17.02%o±1.21%o, respectively）. The bigeye thresher shark has significantly higher 515N value than other shark species, indicating its higher trophic position. The blue shark and oceanic whitetip shark has significantly higher 813C values than bigeye thresher shark, silky shark and scalloped hammerhead, possibly due to different diets and/or living habitats. The stable isotope data and stomach content data are highly consistent, suggesting that sta-ble isotope analysis supplements traditional feeding ecology study of sharks, and thus contributes to understanding their trophic linkage.
