The Effects of Water Deprivation on Cerebrospinal Fluid Constituents During Feeding in Sheep

Sunagawa, Katsunori,Weisinger, Richard S.,McKinley, Michael J.,Purcell, Brett S.,Thomson, Craig,Burns, Peta L. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.4

The internal humoral factors in the central regulation of dry feed intake during water deprivation in sheep were investigated by measurement of cerebrospinal fluid (CSF) constituents. Five animals were fed dried alfalfa chaff for 2 hours once a day. Sheep in the water deprivation treatment were deprived of water for 28 hours, while the sheep in the control treatment were given free access to water. During the first hour of the 2 hour feeding period, a rapid reduction in blood volume occured in both treatments (water deprivation and free access to water). The CSF concentrations of Na, Cl and osmolality during the second hour of the 2 hour feeding period in both treatments were greater (p<0.01) than those during the first hour. The drinking behaviors in sheep were concentrated during the second hour of the 2 hour feeding period in periods of free access to water. Water intake during feeding in periods of free access to water was 1110 ml/2 h. The levels of increase in CSF osmolality with feeding during water deprivation were greater (p<0.01) than during periods of free access to water. The changes in CSF osmolality with feeding during water deprivation produced more vigorous thirst sensations in the brain compared to during periods of free access to water. The eating rates for the first hour of the allotted 2 hour feeding period were the same under both treatments. However, the eating rates for the second hour during water deprivation periods decreased significantly (p<0.05) compared to those during periods of free access to water. The decreased eating rates for the second hour during water deprivation may be due to the vigorous thirst sensations produced in the brain. The results suggest that the increase in CSF osmolality with feeding during water deprivation acts as a thirst and satiety factor in brain mechanisms controlling feeding to decrease dry feed intake in water-deprived sheep.

The Role of Brain Somatostatin in the Central Regulation of Feed, Water and Salt Intake in Sheep

Sunagawa, Katsunori,Weisinger, Richard S.,McKinley, Michael J.,Purcell, Brett S.,Thomson, Craig,Burns, Peta L. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.7

The physiological role of brain somatostatin in the central regulation of feed intake in sheep was investigated through a continuous intracerebroventricular (ICV) infusion of somatostastin 1-28 (SRIF) at a small dose of $5{\mu}g/0.2ml/hr$ for 98.5 hours from day 1 to day 5. Sheep (n=5) were fed for 2 hours once a day, and water and 0.5 M NaCI solution were given ad libitum. Feed, water and salt intake were measured during ICV infusion of artificial cerebrospinal fluid (CSF) and SRIF. The feed intake during SRIF infusion on days 2 to 5 increased significantly compared to that during CSF infusion. Water intake, when compared to that during CSF infusion, only increased significantly on day 4. NaCI intake during SRIF infusion was not different from that during CSF infusion. Mean arterial blood pressure (MAP) and heart rate during SRIF infusion were not different from those during CSF infusion. The plasma concentrations of Na, K, Cl, osmolality and total protein during SRIF infusion were also not different from those values during CSF infusion.There are two possible mechanisms, that is, the suppression of brain SRIF on feed suppressing hormones and the direct actions on brain mechanisms controlling feed intake, explaining how SRIF works in the brain to bring about increases in feed intake in sheep fed on hay. The results indicate that brain SRIF increases feed intake in sheep fed on hay.

The Role of Neuropeptide Y in the Central Regulation of Grass Intake in Sheep

Sunagawa, K.,Weisiger, R.S.,McKinley, M.J.,Purcell, B.S.,Thomson, C.,Burns, P.L. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.1

The physiological role of brain neuropeptide Y (NPY) in the central regulation of grass intake in sheep was investigated through a continuous intracerebroventricular (ICV) infusion of NPY at a dose of $5{\mu}g/0.2ml/hr$ for 98.5 hours from day 1 to day 5. Sheep (n=5) were fed for 2 hours once a day, and water and 0.5 M NaCl solution were given ad libitum. Feed intake during ICV NPY infusion increased significantly compared to that during ICV artificial cerebrospinal fluid (CSF) infusion. Water and NaCl intake during ICV NPY infusion remained unchanged. Mean arterial blood pressure (MAP) and plasma osmolality during ICV NPY infusion were not significantly different from those during ICV CSF infusion. On the other hand, plasma glucose concentration during ICV NPY infusion increased significantly compared to that during ICV CSF infusion. The results suggest that brain NPY acts as a hunger factor in brain mechanisms controlling feeding to increase grass intake in sheep.

The Role of Corticotropin-Releasing Factor and Urocortin in Brain Mechanisms Controlling Feed Intake of Sheep

Sunagawa, K.,Weisiger, R.S.,McKinley, M.J.,Purcell, B.S.,Thomson, C.,Burns, P.L. Asian Australasian Association of Animal Productio 2000 Animal Bioscience Vol.13 No.11

The aim of the present study was to determine whether brain corticotropin-releasing factor (CRF) and a new peptide, urocortin (UCN) have a direct action in brain mechanisms controlling feed, water and salt intake in sheep. We gave a continuous intracerebroventricular (ICV) infusion of the peptide at a small dose of $5{\mu}g/0.2ml/hr$ for 98.5 hrs from day 1 to day 5 in sheep not exposed to stress. Feed and water intake during ICV infusion of CRF or UCN decreased significantly compared to those during artificial cerebrospinal fluid (CSF) infusion. NaCl intake during infusion of CRF or UCN was the same as that during CSF infusion. Mean carotid arterial blood pressure (MAP) and heart rate during ICV infusion of CRF or UCN were not significantly different from that during CSF infusion. On the other hand, the plasma glucose concentration during ICV infusion of CRF or UCN tended to be higher than that during CSF infusion. These observations indicate that decreased feed intake induced by CRF and UCN infusion is not mediated by the activation of both the pituitary-adrenal axis and the sympathetic nervous system. The results suggested that brain CRF and UCN act directly in brain mechanisms controlling ingestive behavior to decrease feed and water intake, but do not alter salt intake in sheep.

Optical effects of anti-glare films on a dual-view display

C.R. Evans,S. Purcell,D. Gullick,P. Weindorf,J. Krier 한국정보디스플레이학회 2016 Journal of information display Vol.17 No.1

The effects of different anti-glare films on an 8-inch dual-view display were investigated. To quantify the display performance, the image sharpness, speckle, and crosstalk were evaluated. The image sharpness and sparkle were first measured, and the obtained values were compared with the results of a jury appraisal for devising acceptance levels. For image sparkle, it was found that the standard deviation for the individual pixel luminance must be less than 40 to be acceptable to the user. Finally, it was found that the crosstalk of the display needs to be less than 0.5 to be unnoticeable and less than 1.0 to be acceptable.

Signatures of minor mergers in the Milky Way disc – I. The SEGUE stellar sample

Gó,mez, Facundo A.,Minchev, Ivan,O’Shea, Brian W.,Lee, Young Sun,Beers, Timothy C.,An, Deokkeun,Bullock, James S.,Purcell, Chris W.,Villalobos, Á,lvaro Blackwell Publishing Ltd 2012 Monthly notices of the Royal Astronomical Society Vol.423 No.4

<P><B>ABSTRACT</B></P><P>It is now known that minor mergers are capable of creating structure in the phase‐space distribution of their host galaxy’s disc. In order to search for such imprints in the Milky Way, we analyse the Sloan Extension for Galactic Understanding and Exploration (SEGUE) F/G dwarf and the Schuster et al. stellar samples. We find similar features in these two completely independent stellar samples, consistent with the predictions of a Milky Way minor‐merger event. We next apply the same analyses to high‐resolution, idealized <I>N</I>‐body simulations of the interaction between the Sagittarius dwarf galaxy and the Milky Way. The energy distributions of stellar particle samples in small spatial regions in the host disc reveal strong variations of structure with position. We find good matches to the observations for models with a mass of Sagittarius’ dark matter halo progenitor <IMG src='/wiley-blackwell_img/lap.gif' alt ='less-than or approximately equal-to'/>10<SUP>11</SUP> M<SUB>⊙</SUB>. Thus, we show that this kind of analysis could be used to provide unprecedentedly tight constraints on Sagittarius’ orbital parameters, as well as place a lower limit on its mass.</P>