An updated view of hypothalamic-vascular-pituitary unit function and plasticity

The discoveries of novel functional adaptations of the hypothalamus and anterior pituitary gland for physiological regulation have transformed our understanding of their interaction. The activity of a small proportion of hypothalamic neurons can control complex hormonal signalling, which is disconnected from a simple stimulus and the subsequent hormone secretion relationship and is dependent on physiological status. The interrelationship of the terminals of hypothalamic neurons and pituitary cells with the vasculature has an important role in determining the pattern of neurohormone exposure. Cells in the pituitary gland form networks with distinct organizational motifs that are related to the duration and pattern of output, and modifications of these networks occur in different physiological states, can persist after cessation of demand and result in enhanced function. Consequently, the hypothalamus and pituitary can no longer be considered as having a simple stratified relationship: with the vasculature they form a tripartite system, which must function in concert for appropriate hypothalamic regulation of physiological processes, such as reproduction. An improved understanding of the mechanisms underlying these regulatory features has implications for current and future therapies that correct defects in hypothalamic–pituitary axes. In addition, recapitulating proper network organization will be an important challenge for regenerative stem cell treatment

New agricultural technology, timeliness and wages for labour: a longitudinal study of rural wages in India

While there is widespread agreement that the spread of new technology crops in India since the mid-1960s has affected rural wages, there is considerable disagreement over the nature of this effect. The existing literature has posed this problem in a demand-supply framework - with a rise in agricultural wages ascribed to increased labour demand caused by this technology change, and stagnant or falling wages attributed to labour supply growth outstripping labour demand. In this paper we reconsider this issue in a modified framework. Within a competitive demand-supply framework we add another aspect of production technology that is idiosyncratic to agriculture, namely, sensitivity of yields to timing of farm operations (say, planting date). It is common knowledge that mistiming can cause substantial yield loss. In a competitive labour market this causes greater impatience on the farmers' part. They are willing to pay a higher wage rather than risk loss of yield. As newer technology crops tend to be more time sensitive, this puts an upward pressure on wages. In this paper we test this hypothesis using annual state-level data from India for the period 1970-85. Delineating the demand-supply effect of new technology on wages from that of the timeliness effect, we indeed find supportive evidence for the above hypothesis.

Kisspeptin-GPR54 Signaling in Mouse NO-Synthesizing Neurons Participates in the Hypothalamic Control of Ovulation

International audienceReproduction is controlled in the brain by a neural network that drives the secretion of gonadotropin-releasing hormone (GnRH). Various permissive homeostatic signals must be integrated to achieve ovulation in mammals. However, the neural events controlling the timely activation of GnRH neurons are not completely understood. Here we show that kisspeptin, a potent activator of GnRH neuronal activity, directly communicates with neurons that synthesize the gaseous transmitter nitric oxide (NO) in the preoptic region to coordinate the progression of the ovarian cycle. Using a transgenic Gpr54-null IRES-LacZ knock-in mouse model, we demonstrate that neurons containing neuronal NO synthase (nNOS), which are morphologically associated with kisspeptin fibers, express the kisspeptin receptor GPR54 in the preoptic region, but not in the tuberal region of the hypothalamus. The activation of kisspeptin signaling in preoptic neurons promotes the activation of nNOS through its phosphorylation on serine 1412 via the AKT pathway and mimics the positive feedback effects of estrogens. Finally, we show that while NO release restrains the reproductive axis at stages of the ovarian cycle during which estrogens exert their inhibitory feedback, it is required for the kisspeptin-dependent preovulatory activation of GnRH neurons. Thus, interactions between kisspeptin and nNOS neurons may play a central role in regulating the hypothalamic-pituitary-gonadal axis in vivo

Design And Fabrication Of A Solar Drying System For Food Preservation

Drying crops by solar energy is of great economic importance the world over, especially in India where most of the crops and grain harvests are lost to fungal and microbial attacks. Proper drying could easily prevent these wastages, which enhances storage of crops and grains over long periods. India is blessed with abundant solar energy all the year round. Drying is oneof the important and most energy consuming processes in the food-processing, chemical, printing, fabric dying industries, etc. In farmer level drying is being done on open yards without any good hygienic conditions. Generally thermal energy, maintained between 45 0C to 25 0 C depending on the products and production methods. A conventional fuel like electricity, firewood, diesel, furnace oil, kerosene, etc is producing that energy. The objective of this project is to modify design of a forced convection indirect solar dryer and its performance test on Grapes. The system consists of an air heating section. The solar dryer consists of different components such as solar panel, battery, heating element and blower. The blower is used to passing the hot air to the required place, so that the moisture contents in the place was removed. It offers a better control over drying and the product obtained is of better quality than sun drying. Solar Dryer Can be operated at higher temperature, recommended for deep layer drying

Does adding clinical data to administrative data improve agreement among hospital quality measures?

BACKGROUND: Hospital performance measures based on patient mortality and readmission have indicated modest rates of agreement. We examined if combining clinical data on laboratory tests and vital signs with administrative data leads to improved agreement with each other, and with other measures of hospital performance in the nation\u27s largest integrated health care system. METHODS: We used patient-level administrative and clinical data, and hospital-level data on quality indicators, for 2007-2010 from the Veterans Health Administration (VA). For patients admitted for acute myocardial infarction (AMI), heart failure (HF) and pneumonia we examined changes in hospital performance on 30-d mortality and 30-d readmission rates as a result of adding clinical data to administrative data. We evaluated whether this enhancement yielded improved measures of hospital quality, based on concordance with other hospital quality indicators. RESULTS: For 30-d mortality, data enhancement improved model performance, and significantly changed hospital performance profiles; for 30-d readmission, the impact was modest. Concordance between enhanced measures of both outcomes, and with other hospital quality measures - including Joint Commission process measures, VA Surgical Quality Improvement Program (VASQIP) mortality and morbidity, and case volume - remained poor. CONCLUSIONS: Adding laboratory tests and vital signs to measure hospital performance on mortality and readmission did not improve the poor rates of agreement across hospital quality indicators in the VA. INTERPRETATION: Efforts to improve risk adjustment models should continue; however, evidence of validation should precede their use as reliable measures of quality

Neuropilin-1 expression in GnRH neurons regulates prepubertal weight gain and sexual attraction.

Hypothalamic neurons expressing gonadotropin-releasing hormone (GnRH), the "master molecule" regulating reproduction and fertility, migrate from their birthplace in the nose to their destination using a system of guidance cues, which include the semaphorins and their receptors, the neuropilins and plexins, among others. Here, we show that selectively deleting neuropilin-1 in new GnRH neurons enhances their survival and migration, resulting in excess neurons in the hypothalamus and in their unusual accumulation in the accessory olfactory bulb, as well as an acceleration of mature patterns of activity. In female mice, these alterations result in early prepubertal weight gain, premature attraction to male odors, and precocious puberty. Our findings suggest that rather than being influenced by peripheral energy state, GnRH neurons themselves, through neuropilin-semaphorin signaling, might engineer the timing of puberty by regulating peripheral adiposity and behavioral switches, thus acting as a bridge between the reproductive and metabolic axes