Within the wide distribution of Lenkoran in Iran, populations of the species inhabit variety of habitats. The authors hypothesized that each river may contribute to habitat-specific variation in life history of the fi...Within the wide distribution of Lenkoran in Iran, populations of the species inhabit variety of habitats. The authors hypothesized that each river may contribute to habitat-specific variation in life history of the fish. To test this, a total of 378 specimens of Capoeta capoeta gracilis caught in the Atrak river （northern Iran） from Dec. 2007 to Nov. 2008 were examined for life history attributes. The population has a 5-year life cycle. Weight-length relationship （WLR） was estimated as W = 0.0127TL28981 for males, W = 0.0083TL3998 for females and W = 0.0084TL3942 for the population, being allometric negative for males and positive for females and the population. The VBGF fit to back-calculated size at age data were： Lt = 22.11 （1-e-0.19（t＋135））, Lt = 25.37 （1-e-0.18（t＋125）） and Lt = 24.92 （1-e-018（1＋122）） for males, females and sexes combined respectively. Sex ratio was significant from the parity, females dominated. The reproductive season, evaluated from GSI, extended from Apr. to July, with the highest peak in May for males and in Apr. for females. The absolute fecundity ranged between 458-5,743 eggs with a mean of 1,375.06 eggs. Fecundity relative to total weight fluctuated from 14.90 to 132.58, with a mean value of 48.79 eggs·g-1. The diameter of oocytes ranged from 0.53 to 2.40 mm with a mean value of 1.46. The life history patterns of C. c. gracilis in the considered population imply that the many population characteristics of this species in the river differ markedly from those of other rivers of its range distribution in northern Iran. Probably, respond to environmental characteristics to improve fitness locally is the more suitable choice for differentiated life history strategies of the species in the river.展开更多
Current literature shows that short sellers earn positive returns on their trades and that the superior performance of short sellers is due to their better analytic skills. In this paper, we investigate, if it is poss...Current literature shows that short sellers earn positive returns on their trades and that the superior performance of short sellers is due to their better analytic skills. In this paper, we investigate, if it is possible for a short seller to make profits even if he does not have insider information or is not sophisticated. We use a one period model and assume that stock price follows a random walk with a positive drift to show that the＇ expected return for an uninformed short seller is always negative and his risks are always greater than the risks of a stock buyer. Hence a short seller would not trade unless he has superior trading skills and/or information. We also show that the market conditions when the stock＇s dividend yield is greater than the risk free rate gives the shortsellers advantage over stock buyers.展开更多
Injury of the superior cluneal nerve is acommonly encountered affection in clinical practice.The author treated 80 cases of injury of the superiorcluneal nerve by electr0acupuncture from August1991 to August 1998,with...Injury of the superior cluneal nerve is acommonly encountered affection in clinical practice.The author treated 80 cases of injury of the superiorcluneal nerve by electr0acupuncture from August1991 to August 1998,with other 77 cases treated byacupuncture as the controls.The result is reported asfollow.General Data157 OUtpatients were randomly diVided into thetreatment group and the control group.Among展开更多
文摘Within the wide distribution of Lenkoran in Iran, populations of the species inhabit variety of habitats. The authors hypothesized that each river may contribute to habitat-specific variation in life history of the fish. To test this, a total of 378 specimens of Capoeta capoeta gracilis caught in the Atrak river （northern Iran） from Dec. 2007 to Nov. 2008 were examined for life history attributes. The population has a 5-year life cycle. Weight-length relationship （WLR） was estimated as W = 0.0127TL28981 for males, W = 0.0083TL3998 for females and W = 0.0084TL3942 for the population, being allometric negative for males and positive for females and the population. The VBGF fit to back-calculated size at age data were： Lt = 22.11 （1-e-0.19（t＋135））, Lt = 25.37 （1-e-0.18（t＋125）） and Lt = 24.92 （1-e-018（1＋122）） for males, females and sexes combined respectively. Sex ratio was significant from the parity, females dominated. The reproductive season, evaluated from GSI, extended from Apr. to July, with the highest peak in May for males and in Apr. for females. The absolute fecundity ranged between 458-5,743 eggs with a mean of 1,375.06 eggs. Fecundity relative to total weight fluctuated from 14.90 to 132.58, with a mean value of 48.79 eggs·g-1. The diameter of oocytes ranged from 0.53 to 2.40 mm with a mean value of 1.46. The life history patterns of C. c. gracilis in the considered population imply that the many population characteristics of this species in the river differ markedly from those of other rivers of its range distribution in northern Iran. Probably, respond to environmental characteristics to improve fitness locally is the more suitable choice for differentiated life history strategies of the species in the river.
文摘Current literature shows that short sellers earn positive returns on their trades and that the superior performance of short sellers is due to their better analytic skills. In this paper, we investigate, if it is possible for a short seller to make profits even if he does not have insider information or is not sophisticated. We use a one period model and assume that stock price follows a random walk with a positive drift to show that the＇ expected return for an uninformed short seller is always negative and his risks are always greater than the risks of a stock buyer. Hence a short seller would not trade unless he has superior trading skills and/or information. We also show that the market conditions when the stock＇s dividend yield is greater than the risk free rate gives the shortsellers advantage over stock buyers.
文摘Injury of the superior cluneal nerve is acommonly encountered affection in clinical practice.The author treated 80 cases of injury of the superiorcluneal nerve by electr0acupuncture from August1991 to August 1998,with other 77 cases treated byacupuncture as the controls.The result is reported asfollow.General Data157 OUtpatients were randomly diVided into thetreatment group and the control group.Among
