The gonadotropin releasing hormone (GnRH) is secreted by hypothalamic neurons into the pituitary portal blood in a pulsatile manner. The alternation between a frequency-modulated pulsatile regime and the ovulatory surge is the hallmark of the GnRH secretion pattern in ovarian cycles of female mammals. In this work, we aim at modeling additional features of the GnRH secretion pattern: the possib...

In her article "The Image of Ireland in Iberian Galicia in the Early Twentieth Century," Anne MacCarthy explores Galician intellectuals' relationship with Ireland in their attempt to create a Celtic imaginary for Galicia which would act as a cultural fortification in the face of centralizing forces of Castilian Spain. In periodicals prominent in the 1920s, Nós and A Nosa Terra, the wish to cons...

Today’s information technology departments have widely varying demands for resources due to unexpected surges in subscriber demands (e.g., a large response to a product promotion). Further complicating matters is that many resource actions done in response to surges (e.g., provisioning or de-provisioning an application server) have substantial delays (lead times) between initiating the resource...

The increasing use of electronics in residential applications has been paralleled by a realization that surge protection may be necessary for this type of equipment. Installing a surge-protective device on the power-line port as well as on the communications-line port of an equipment might appear sufficient to ensure this protection. However, the normal operation of one of the protective device...

Failure and circuit upset of electronic equipment due to transients is a problem now and is one which has promise of becoming more of a problem in the future as trends continue toward miniaturization and circuit complexity. Protection methods are used more or less extensively and often haphazardly. At present, there does not appear to be a clear approach toward achieving compatibility between t...

This invited lecture was presented at a forum organized by the National Bureau of Standards (NBS) under the auspices of the same organization that developed the publication FIPS PUB 94 “Guideline on Electrical Power for ADP Installations, ” a widely disseminated and often-cited tutorial document in the eighties and nineties. My subjects were presented within the broad scope of the forum, with e...

New transient suppressors using meta l oxide varistors offer improved protection of appliances and consumer electronics against overvoltages. This improvement, however, could be at t h e risk of imposing excessive duty on t h e suppressor in case of a very severe lightning s t roke near the house where these suppressors a r e installed. A simulated house wiring system was subjected to three lev...

Stress elicits activation of the hypothalamic-pituitary-adrenal axis, which leads to enhanced circulating glucocorticoids, as well as impaired gonadotropin secretion and ovarian cyclicity. Here, we tested the hypothesis that elevated, stress-levels of glucocorticoids disrupt ovarian cyclicity by interfering with the preovulatory sequence of endocrine events necessary for the LH surge. Ovarian c...

Reproductive aging is characterized by delayed and attenuated luteinizing hormone (LH) surges apparent in middle-aged rats. The suprachiasmatic nucleus (SCN) contains the circadian clock that is responsible for the timing of diverse neuroendocrine rhythms. Electrophysiological studies suggest vasoactive intestinal peptide (VIP) originating from the SCN excites gonadotropin-releasing hormone (Gn...

BACKGROUND There is no consensus on the exact parameters that define the LH surge for natural cycle frozen-thawed embryo transfers (NC-FET). Accurately determining the LH surge would affect the timing, and subsequently the success rates, of embryo transfer. Therefore, the aim of this study was to delineate the optimal levels and relationship for luteinizing hormone (LH) and estradiol in an effo...