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For years Wikipedia has come to symbolize the potential of Web 2.0 for harnessing the power of mass collaboration and collective intelligence. As wikis continue to develop and move into streams of cultural, social, academic, and enterprise work activity, it is appropriate to consider how collective intelligence emerges from mass collaboration. Collective(More)
Fertile life of oocytes is usually considered to be related to ovulation time. In the present study, fertile life of rat oocytes was studied in relation to resumption of meiosis. In pro-oestrus, meiotic resumption without concomitant ovulation was induced in most graafian follicles by injection of a small amount of LH or FSH followed by Nembutal. These(More)
BACKGROUND/AIMS Central but also peripheral IGF-1 is suggested to play a role in the initiation of puberty as it directly affects GnRH synthesis and release. A possible intermediate in the effects of IGF-1 on puberty might be the adiposity-signaling hormone leptin, whose plasma levels are decreased in food-restricted (FR) rats. METHODS IGF-1 was(More)
The brain might initiate puberty in response to adequate leptin signaling from the periphery. We studied the link between whole body fat, plasma leptin levels, and puberty onset, in both controls and food-restricted female Wistar rats from age 22 to 42 days. Body fat correlated positively with the prevailing plasma leptin levels (r = 0.776) and with the(More)
The effects of intravenous (iv) administration of the opioid antagonists naloxone and naltrexone on the restraint-induced suppression of the pro-estrous LH surge were studied in cyclic female rats. To minimize stress during repeated blood sampling, the rats were provided with a jugular vein cannula. Restraint stress for 6 hrs starting at t = -1 h (the onset(More)
The response of plasma prolactin in vigorous suckling was measured in lactating rats which had been isolated for 10-12 h from their offspring. Plasma prolactin was investigated during suckling at various stages of lactation. The results demonstrate that prolactin responds maximally to suckling already in the first days of lactation. In the second half of(More)
The effect of intracerebroventricular (i.c.v.) injection or infusion of various doses of corticotropin-releasing hormone (CRH) on the LH and FSH surge was studied in pro-oestrous rats supplied with a jugular vein and an i.c.v. cannula. Additionally, we investigated if arginine vasopressin (AVP) was involved in the CRH-induced alterations to the surge of(More)
The pituitary-ovarian axis was studied after withdrawal of thyroid hormone in 131I-radiothyroidectomized adult female rats. Oestrous cycles became prolonged and irregular within 2 weeks after the supply of thyroid hormone was stopped. If an LH surge occurred in hypothyroid rats on the day of vaginal pro-oestrus it was significantly greater in rats which had(More)
After ovulation, the fertile life of oocytes is short. In the present study, the fertile life of oocytes was studied in relation to the resumption of meiosis. Early on the day of pro-oestrus, meiotic resumption was advanced in rats by a brief infusion of LH; ovulation was induced 8 h later by Ovalyse, a GnRH analogue; rats were mated 13 h after receiving(More)