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Behrens JW, Gräns A, Andersen NG, Neuenfeldt S, Axelsson M. Recovery of gastric evacuation rate in Atlantic cod Gadus morhua L surgically implanted with a dummy telemetry device. Lab Anim 2011; 45:240-6. [PMID: 21771807 DOI: 10.1258/la.2011.011013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The current study investigated how the gastric evacuation rate (GER) was affected after surgically introducing dummies of a blood flow biotelemetry system into the abdominal cavity of Atlantic cod, Gadus morhua. Gastric evacuation experiments were performed two and 10 days postsurgery on surgically implanted and control G. morhua force-fed sandeel, Ammodytes tobianus. The results were compared with previously obtained estimates from unstressed conspecifics voluntarily feeding on a similar diet. After two days, GER was significantly lower in the group of fish with the dummy implants compared with the control group, but following 10 days of recovery no significant difference was seen between the two groups. The difference between implanted and control fish observed two days postsurgery may have resulted either from surgery, postsurgical stress and/or the presence of the implant. The conclusion is that 10 days of postsurgical recovery will stabilize GER in G. morhua, thus indicating that at this point the implant per se did not affect GER. Both the fish with surgical implants and controls in this study evacuated their stomachs much slower and with much higher interindividual variation compared with G. morhua feeding voluntarily on similar prey items. The lower GER and higher interindividual variation for force-fed fish indicate that handling, anaesthetization and force-feeding impair GER and that individual fish respond differently to the suppressing effects.
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Gräns A, Olsson C, Pitsillides K, Nelson HE, Cech JJ, Axelsson M. Effects of feeding on thermoregulatory behaviours and gut blood flow in white sturgeon (Acipenser transmontanus) using biotelemetry in combination with standard techniques. ACTA ACUST UNITED AC 2010; 213:3198-206. [PMID: 20802122 DOI: 10.1242/jeb.043570] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effects of thermoregulatory behaviours on gut blood flow in white sturgeon Acipenser transmontanus before and after feeding was studied using a blood flow biotelemetry system in combination with a temperature preference chamber. This is the first study to look at cardiovascular responses to feeding in white sturgeon, and also the first time behavioural tests in fish have been combined with recordings of cardiac output, heart rate, cardiac stroke volume and gut blood flow. The results showed strong correlations between gut blood flow and temperature choice after feeding (R(2)=0.88+/-0.03, 6-8 h postprandially and R(2)=0.89+/-0.04, 8-10 h postprandially) but not prior to feeding (R(2)=0.11+/-0.05). Feeding did not affect the actual temperature preference (18.4+/-0.7 degrees C before feeding, 18.1+/-0.7 degrees C, 6-8 h postprandially and 17.5+/-0.5 degrees C, 8-10 h postprandially). Fish instrumented with a blood flow biotelemetry device, and allowed to move freely in the water, had a significantly lower resting heart rate (37.3+/-0.26 beats min(-1)) compared with the control group that was traditionally instrumented with transit-time blood flow probes and kept in a confined area in accordance with the standard procedure (43.2+/-2.1 beats min(-1)). This study shows, for the first time in fish, the correlation between body temperature and gut blood flow during behavioural thermoregulation.
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Abdo AA, Ackermann M, Ajello M, Anderson B, Atwood WB, Axelsson M, Baldini L, Ballet J, Barbiellini G, Bastieri D, Baughman BM, Bechtol K, Bellazzini R, Berenji B, Blandford RD, Bloom ED, Bonamente E, Borgland AW, Bregeon J, Brez A, Brigida M, Bruel P, Burnett TH, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Cecchi C, Charles E, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Conrad J, Dereli H, Dermer CD, de Angelis A, de Palma F, Digel SW, Di Bernardo G, Dormody M, do Couto e Silva E, Drell PS, Dubois R, Dumora D, Edmonds Y, Farnier C, Favuzzi C, Fegan SJ, Focke WB, Frailis M, Fukazawa Y, Funk S, Fusco P, Gaggero D, Gargano F, Gehrels N, Germani S, Giebels B, Giglietto N, Giordano F, Glanzman T, Godfrey G, Grenier IA, Grondin MH, Grove JE, Guillemot L, Guiriec S, Hanabata Y, Harding AK, Hayashida M, Hays E, Hughes RE, Jóhannesson G, Johnson AS, Johnson RP, Johnson TJ, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kawai N, Kerr M, Knödlseder J, Kocian ML, Kuehn F, Kuss M, Lande J, Latronico L, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Makeev A, Mazziotta MN, McConville W, McEnery JE, Meurer C, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monte C, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Nolan PL, Nuss E, Ohsugi T, Okumura A, Omodei N, Orlando E, Ormes JF, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Piron F, Porter TA, Rainò S, Rando R, Razzano M, Reimer A, Reimer O, Reposeur T, Ritz S, Rodriguez AY, Roth M, Ryde F, Sadrozinski HFW, Sanchez D, Sander A, Saz Parkinson PM, Scargle JD, Sellerholm A, Sgrò C, Smith DA, Smith PD, Spandre G, Spinelli P, Starck JL, Stecker FW, Striani E, Strickman MS, Strong AW, Suson DJ, Tajima H, Takahashi H, Tanaka T, Thayer JB, Thayer JG, Thompson DJ, Tibaldo L, Torres DF, Tosti G, Tramacere A, Uchiyama Y, Usher TL, Vasileiou V, Vilchez N, Vitale V, Waite AP, Wang P, Winer BL, Wood KS, Ylinen T, Ziegler M. Fermi large area telescope measurements of the diffuse gamma-ray emission at intermediate galactic latitudes. PHYSICAL REVIEW LETTERS 2009; 103:251101. [PMID: 20366246 DOI: 10.1103/physrevlett.103.251101] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Indexed: 05/29/2023]
Abstract
The diffuse galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess gamma-ray emission greater, > or approximately equal to 1 GeV relative to diffuse galactic gamma-ray emission models consistent with directly measured CR spectra (the so-called "EGRET GeV excess"). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse gamma-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10 degrees < or = |b| < or = 20 degrees. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic gamma-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.
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Abdo AA, Ackermann M, Ajello M, Axelsson M, Baldini L, Ballet J, Barbiellini G, Bastieri D, Baughman B, Bechtol K, Bellazzini R, Berenji B, Blandford RD, Bloom ED, Bonamente E, Borgland AW, Brez A, Brigida M, Bruel P, Burnett TH, Buson S, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Cecchi C, Çelik Ö, Chaty S, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen Tanugi J, Cominsky LR, Conrad J, Corbel S, Corbet R, Dermer CD, de Palma F, Digel S, do Couto e Silva E, Drell PS, Dubois R, Dubus G, Dumora D, Farnier C, Favuzzi C, Fegan SJ, Focke WB, Fortin P, Frailis M, Fusco P, Gargano F, Gehrels N, Germani S, Giavitto G, Giebels B, Giglietto N, Giordano F, Glanzman T, Godfrey G, Grenier IA, Grondin MH, Grove JE, Guillemot L, Guiriec S, Hanabata Y, Harding A, Hayashida M, Hays E, Hill AB, Hjalmarsdotter L, Horan D, Hughes RE, Jackson MS, Jóhannesson G, Johnson AS, Johnson TJ, Johnson WN, Kamae T, Katagiri H, Kawai N, Kerr M, Knödlseder J, Kocian ML, Koerding E, Kuss M, Lande J, Latronico L, Lemoine Goumard M, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Makeev A, Marchand L, Marelli M, Moerbeck WM, Mazziotta MN, McColl N, McEnery JE, Meurer C, Michelson PF, Migliari S, Mitthumsiri W, Mizuno T, Monte C, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Nolan PL, Norris JP, Nuss E, Ohsugi T, Omodei N, Ong RA, Ormes JF, Paneque D, Parent D, Pelassa V, Pepe M, Rollins MP, Piron F, Pooley G, Porter TA, Pottschmidt K, Rainò S, Rando R, Ray PS, Razzano M, Rea N, Readhead A, Reimer A, Reimer O, Richards JL, Rochester LS, Rodriguez J, Rodriguez AY, Romani RW, Ryde F, Sadrozinski HFW, Sander A, Parkinson PMS, Sgrò C, Siskind EJ, Smith DA, Smith PD, Spinelli P, Starck JL, Stevenson M, Strickman MS, Suson DJ, Takahashi H, Tanaka T, Thayer JB, Thompson DJ, Tibaldo L, Tomsick JA, Torres DF, Tosti G, Tramacere A, Uchiyama Y, Usher TL, Vasileiou V, Vilchez N, Vitale V, Waite AP, Wang P, Wilms J, Winer BL, Wood KS, Ylinen T, Ziegler M. Modulated High-Energy Gamma-Ray Emission from the Microquasar Cygnus X-3. Science 2009; 326:1512-6. [DOI: 10.1126/science.1182174] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Abdo AA, Ackermann M, Ajello M, Atwood WB, Axelsson M, Baldini L, Ballet J, Barbiellini G, Bastieri D, Baughman BM, Bechtol K, Bellazzini R, Berenji B, Blandford RD, Bloom ED, Bonamente E, Borgland AW, Bregeon J, Brez A, Brigida M, Bruel P, Burnett TH, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Cecchi C, Celik O, Charles E, Chaty S, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Conrad J, Cutini S, Dermer CD, de Palma F, Digel SW, Dormody M, do Couto e Silva E, Drell PS, Dubois R, Dumora D, Farnier C, Favuzzi C, Fegan SJ, Focke WB, Frailis M, Fukazawa Y, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giebels B, Giglietto N, Giordano F, Glanzman T, Godfrey G, Grenier IA, Grove JE, Guillemot L, Guiriec S, Hanabata Y, Harding AK, Hayashida M, Hays E, Horan D, Hughes RE, Jóhannesson G, Johnson AS, Johnson RP, Johnson TJ, Johnson WN, Kamae T, Katagiri H, Kawai N, Kerr M, Knödlseder J, Kuehn F, Kuss M, Lande J, Latronico L, Lemoine-Goumard M, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Makeev A, Mazziotta MN, McConville W, McEnery JE, Meurer C, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monte C, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Nolan PL, Norris JP, Nuss E, Ohsugi T, Omodei N, Orlando E, Ormes JF, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Pierbattista M, Piron F, Porter TA, Rainò S, Rando R, Razzano M, Rea N, Reimer A, Reimer O, Reposeur T, Ritz S, Rochester LS, Rodriguez AY, Romani RW, Roth M, Ryde F, Sadrozinski HFW, Sanchez D, Sander A, Saz Parkinson PM, Sgrò C, Smith DA, Smith PD, Spandre G, Spinelli P, Starck JL, Strickman MS, Suson DJ, Tajima H, Takahashi H, Tanaka T, Thayer JB, Thayer JG, Thompson DJ, Tibaldo L, Torres DF, Tosti G, Tramacere A, Uchiyama Y, Usher TL, Vasileiou V, Vilchez N, Vitale V, Wang P, Webb N, Winer BL, Wood KS, Ylinen T, Ziegler M. Detection of high-energy gamma-ray emission from the globular cluster 47 Tucanae with Fermi. Science 2009; 325:845-8. [PMID: 19679807 DOI: 10.1126/science.1177023] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We report the detection of gamma-ray emissions above 200 megaelectron volts at a significance level of 17sigma from the globular cluster 47 Tucanae, using data obtained with the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. Globular clusters are expected to emit gamma rays because of the large populations of millisecond pulsars that they contain. The spectral shape of 47 Tucanae is consistent with gamma-ray emission from a population of millisecond pulsars. The observed gamma-ray luminosity implies an upper limit of 60 millisecond pulsars present in 47 Tucanae.
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Abdo A, Ackermann M, Ajello M, Atwood W, Axelsson M, Baldini L, Ballet J, Barbiellini G, Baring M, Bastieri D, Baughman B, Bechtol K, Bellazzini R, Berenji B, Bignami G, Blandford R, Bloom E, Bonamente E, Borgland A, Bregeon J, Brez A, Brigida M, Bruel P, Burnett T, Caliandro G, Cameron R, Camilo F, Caraveo P, Carlson P, Casandjian J, Cecchi C, Çelik Ö, Charles E, Chekhtman A, Cheung C, Chiang J, Ciprini S, Claus R, Cognard I, Cohen-Tanugi J, Cominsky L, Conrad J, Corbet R, Cutini S, Dermer C, Desvignes G, de Angelis A, de Luca A, de Palma F, Digel S, Dormody M, do Couto e Silva E, Drell P, Dubois R, Dumora D, Edmonds Y, Farnier C, Favuzzi C, Fegan S, Focke W, Frailis M, Freire P, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giebels B, Giglietto N, Giordano F, Glanzman T, Godfrey G, Grenier I, Grondin MH, Grove J, Guillemot L, Guiriec S, Hanabata Y, Harding A, Hayashida M, Hays E, Hobbs G, Hughes R, Jóhannesson G, Johnson A, Johnson R, Johnson T, Johnson W, Johnston S, Kamae T, Katagiri H, Kataoka J, Kawai N, Kerr M, Knödlseder J, Kocian M, Kramer M, Kuss M, Lande J, Latronico L, Lemoine-Goumard M, Longo F, Loparco F, Lott B, Lovellette M, Lubrano P, Madejski G, Makeev A, Manchester R, Marelli M, Mazziotta M, McConville W, McEnery J, McLaughlin M, Meurer C, Michelson P, Mitthumsiri W, Mizuno T, Moiseev A, Monte C, Monzani M, Morselli A, Moskalenko I, Murgia S, Nolan P, Norris J, Nuss E, Ohsugi T, Omodei N, Orlando E, Ormes J, Paneque D, Panetta J, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Piron F, Porter T, Rainò S, Rando R, Ransom S, Ray P, Razzano M, Rea N, Reimer A, Reimer O, Reposeur T, Ritz S, Rochester L, Rodriguez A, Romani R, Roth M, Ryde F, Sadrozinski HW, Sanchez D, Sander A, Saz Parkinson P, Scargle J, Schalk T, Sgrò C, Siskind E, Smith D, Smith P, Spandre G, Spinelli P, Stappers B, Starck JL, Striani E, Strickman M, Suson D, Tajima H, Takahashi H, Tanaka T, Thayer J, Thayer J, Theureau G, Thompson D, Thorsett S, Tibaldo L, Torres D, Tosti G, Tramacere A, Uchiyama Y, Usher T, Van Etten A, Vasileiou V, Venter C, Vilchez N, Vitale V, Waite A, Wallace E, Wang P, Watters K, Webb N, Weltevrede P, Winer B, Wood K, Ylinen T, Ziegler M. A Population of Gamma-Ray Millisecond Pulsars Seen with the Fermi Large Area Telescope. Science 2009; 325:848-52. [DOI: 10.1126/science.1176113] [Citation(s) in RCA: 175] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Abdo AA, Ackermann M, Ajello M, Anderson B, Atwood WB, Axelsson M, Baldini L, Ballet J, Barbiellini G, Baring MG, Bastieri D, Baughman BM, Bechtol K, Bellazzini R, Berenji B, Bignami GF, Blandford RD, Bloom ED, Bonamente E, Borgland AW, Bregeon J, Brez A, Brigida M, Bruel P, Burnett TH, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Cecchi C, Celik O, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Conrad J, Cutini S, Dermer CD, de Angelis A, de Luca A, de Palma F, Digel SW, Dormody M, do Couto e Silva E, Drell PS, Dubois R, Dumora D, Farnier C, Favuzzi C, Fegan SJ, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giebels B, Giglietto N, Giommi P, Giordano F, Glanzman T, Godfrey G, Grenier IA, Grondin MH, Grove JE, Guillemot L, Guiriec S, Gwon C, Hanabata Y, Harding AK, Hayashida M, Hays E, Hughes RE, Jóhannesson G, Johnson RP, Johnson TJ, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kawai N, Kerr M, Knödlseder J, Kocian ML, Kuss M, Lande J, Latronico L, Lemoine-Goumard M, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Makeev A, Marelli M, Mazziotta MN, McConville W, McEnery JE, Meurer C, Michelson PF, Mitthumsiri W, Mizuno T, Monte C, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Nolan PL, Norris JP, Nuss E, Ohsugi T, Omodei N, Orlando E, Ormes JF, Paneque D, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Pierbattista M, Piron F, Porter TA, Primack JR, Rainò S, Rando R, Ray PS, Razzano M, Rea N, Reimer A, Reimer O, Reposeur T, Ritz S, Rochester LS, Rodriguez AY, Romani RW, Ryde F, Sadrozinski HFW, Sanchez D, Sander A, Saz Parkinson PM, Scargle JD, Sgrò C, Siskind EJ, Smith DA, Smith PD, Spandre G, Spinelli P, Starck JL, Strickman MS, Suson DJ, Tajima H, Takahashi H, Takahashi T, Tanaka T, Thayer JG, Thompson DJ, Tibaldo L, Tibolla O, Torres DF, Tosti G, Tramacere A, Uchiyama Y, Usher TL, Van Etten A, Vasileiou V, Vilchez N, Vitale V, Waite AP, Wang P, Watters K, Winer BL, Wolff MT, Wood KS, Ylinen T, Ziegler M. Detection of 16 gamma-ray pulsars through blind frequency searches using the Fermi LAT. Science 2009; 325:840-4. [PMID: 19574346 DOI: 10.1126/science.1175558] [Citation(s) in RCA: 237] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.
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Abdo AA, Ackermann M, Ajello M, Atwood WB, Axelsson M, Baldini L, Ballet J, Barbiellini G, Bastieri D, Battelino M, Baughman BM, Bechtol K, Bellazzini R, Berenji B, Blandford RD, Bloom ED, Bogaert G, Bonamente E, Borgland AW, Bregeon J, Brez A, Brigida M, Bruel P, Burnett TH, Caliandro GA, Cameron RA, Caraveo PA, Carlson P, Casandjian JM, Cecchi C, Charles E, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Cominsky LR, Conrad J, Cutini S, Dermer CD, de Angelis A, de Palma F, Digel SW, Di Bernardo G, do Couto E Silva E, Drell PS, Dubois R, Dumora D, Edmonds Y, Farnier C, Favuzzi C, Focke WB, Frailis M, Fukazawa Y, Funk S, Fusco P, Gaggero D, Gargano F, Gasparrini D, Gehrels N, Germani S, Giebels B, Giglietto N, Giordano F, Glanzman T, Godfrey G, Grasso D, Grenier IA, Grondin MH, Grove JE, Guillemot L, Guiriec S, Hanabata Y, Harding AK, Hartman RC, Hayashida M, Hays E, Hughes RE, Jóhannesson G, Johnson AS, Johnson RP, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kawai N, Kerr M, Knödlseder J, Kocevski D, Kuehn F, Kuss M, Lande J, Latronico L, Lemoine-Goumard M, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Makeev A, Massai MM, Mazziotta MN, McConville W, McEnery JE, Meurer C, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monte C, Monzani ME, Moretti E, Morselli A, Moskalenko IV, Murgia S, Nolan PL, Norris JP, Nuss E, Ohsugi T, Omodei N, Orlando E, Ormes JF, Ozaki M, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Piron F, Pohl M, Porter TA, Profumo S, Rainò S, Rando R, Razzano M, Reimer A, Reimer O, Reposeur T, Ritz S, Rochester LS, Rodriguez AY, Romani RW, Roth M, Ryde F, Sadrozinski HFW, Sanchez D, Sander A, Saz Parkinson PM, Scargle JD, Schalk TL, Sellerholm A, Sgrò C, Smith DA, Smith PD, Spandre G, Spinelli P, Starck JL, Stephens TE, Strickman MS, Strong AW, Suson DJ, Tajima H, Takahashi H, Takahashi T, Tanaka T, Thayer JB, Thayer JG, Thompson DJ, Tibaldo L, Tibolla O, Torres DF, Tosti G, Tramacere A, Uchiyama Y, Usher TL, Van Etten A, Vasileiou V, Vilchez N, Vitale V, Waite AP, Wallace E, Wang P, Winer BL, Wood KS, Ylinen T, Ziegler M. Measurement of the cosmic ray e+ +e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope. PHYSICAL REVIEW LETTERS 2009; 102:181101. [PMID: 19518855 DOI: 10.1103/physrevlett.102.181101] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Indexed: 05/27/2023]
Abstract
Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m;{2} sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E-3.0 and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed.
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Abdo AA, Ackermann M, Arimoto M, Asano K, Atwood WB, Axelsson M, Baldini L, Ballet J, Band DL, Barbiellini G, Baring MG, Bastieri D, Battelino M, Baughman BM, Bechtol K, Bellardi F, Bellazzini R, Berenji B, Bhat PN, Bissaldi E, Blandford RD, Bloom ED, Bogaert G, Bogart JR, Bonamente E, Bonnell J, Borgland AW, Bouvier A, Bregeon J, Brez A, Briggs MS, Brigida M, Bruel P, Burnett TH, Burrows D, Busetto G, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Ceccanti M, Cecchi C, Celotti A, Charles E, Chekhtman A, Cheung CC, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Cominsky LR, Connaughton V, Conrad J, Costamante L, Cutini S, DeKlotz M, Dermer CD, de Angelis A, de Palma F, Digel SW, Dingus BL, do Couto e Silva E, Drell PS, Dubois R, Dumora D, Edmonds Y, Evans PA, Fabiani D, Farnier C, Favuzzi C, Finke J, Fishman G, Focke WB, Frailis M, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giebels B, Giglietto N, Giommi P, Giordano F, Glanzman T, Godfrey G, Goldstein A, Granot J, Greiner J, Grenier IA, Grondin MH, Grove JE, Guillemot L, Guiriec S, Haller G, Hanabata Y, Harding AK, Hayashida M, Hays E, Hernando Morat JA, Hoover A, Hughes RE, Jóhannesson G, Johnson AS, Johnson RP, Johnson TJ, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kavelaars A, Kawai N, Kelly H, Kennea J, Kerr M, Kippen RM, Knödlseder J, Kocevski D, Kocian ML, Komin N, Kouveliotou C, Kuehn F, Kuss M, Lande J, Landriu D, Larsson S, Latronico L, Lavalley C, Lee B, Lee SH, Lemoine-Goumard M, Lichti GG, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Makeev A, Marangelli B, Mazziotta MN, McBreen S, McEnery JE, McGlynn S, Meegan C, Mészáros P, Meurer C, Michelson PF, Minuti M, Mirizzi N, Mitthumsiri W, Mizuno T, Moiseev AA, Monte C, Monzani ME, Moretti E, Morselli A, Moskalenko IV, Murgia S, Nakamori T, Nelson D, Nolan PL, Norris JP, Nuss E, Ohno M, Ohsugi T, Okumura A, Omodei N, Orlando E, Ormes JF, Ozaki M, Paciesas WS, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Perri M, Pesce-Rollins M, Petrosian V, Pinchera M, Piron F, Porter TA, Preece R, Rainò S, Ramirez-Ruiz E, Rando R, Rapposelli E, Razzano M, Razzaque S, Rea N, Reimer A, Reimer O, Reposeur T, Reyes LC, Ritz S, Rochester LS, Rodriguez AY, Roth M, Ryde F, Sadrozinski HFW, Sanchez D, Sander A, Saz Parkinson PM, Scargle JD, Schalk TL, Segal KN, Sgrò C, Shimokawabe T, Siskind EJ, Smith DA, Smith PD, Spandre G, Spinelli P, Stamatikos M, Starck JL, Stecker FW, Steinle H, Stephens TE, Strickman MS, Suson DJ, Tagliaferri G, Tajima H, Takahashi H, Takahashi T, Tanaka T, Tenze A, Thayer JB, Thayer JG, Thompson DJ, Tibaldo L, Torres DF, Tosti G, Tramacere A, Turri M, Tuvi S, Usher TL, van der Horst AJ, Vigiani L, Vilchez N, Vitale V, von Kienlin A, Waite AP, Williams DA, Wilson-Hodge C, Winer BL, Wood KS, Wu XF, Yamazaki R, Ylinen T, Ziegler M. Fermi Observations of High-Energy Gamma-Ray Emission from GRB 080916C. Science 2009; 323:1688-93. [DOI: 10.1126/science.1169101] [Citation(s) in RCA: 478] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Axelsson M, Emilsson M, Brink E, Lundgren J, Torén K, Lötvall J. Personality, adherence, asthma control and health-related quality of life in young adult asthmatics. Respir Med 2009; 103:1033-40. [PMID: 19217764 DOI: 10.1016/j.rmed.2009.01.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 01/12/2009] [Accepted: 01/14/2009] [Indexed: 11/29/2022]
Abstract
BACKGROUND Striving for improved adherence and asthma control is of vital concern in today's asthma management. Several influential factors have been identified, but the importance of personality traits has been insufficiently explored. The aim was first to determine whether personality traits in young adult asthmatics are related to asthma control and health-related quality of life (HRQL), and second to examine the influences of personality traits on adherence to regular asthma medication treatment. METHODS Young adult asthmatics, 22 years of age (n=268) completed questionnaires. Statistical analyses were performed. RESULTS The personality traits Negative Affectivity and Impulsivity correlated negatively with asthma control, whereas in women Hedonic Capacity correlated positively with asthma control. Negative Affectivity, Impulsivity, Hedonic Capacity, Alexithymia and asthma control predicted the mental dimension of HRQL. Asthma control and physical activity predicted the physical dimension of HRQL. Among respondents with regular asthma medication (n=109), Impulsivity correlated negatively with adherence. In men, Antagonism and Alexithymia were associated with low adherence. Additionally, Alexithymia, Hedonic Capacity and Negative Affectivity showed non-linear relationships with adherence, meaning that initially increased scores on these personality traits scales were associated with increased adherence but higher scores did not increase adherence. Respondents who were prescribed a single inhaler combining ICS and LABA reported higher adherence than those with monotherapies. CONCLUSION These data suggest that personality can influence how asthma patients adhere to asthma medication treatment, and report their control and HRQL. Tools determining personality traits may be useful in the future in individualizing management of asthma patients.
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Mattsson N, Axelsson M, Haghighi S, Malmeström C, Wu G, Anckarsäter R, Sankaranarayanan S, Andreasson U, Fredrikson S, Gundersen A, Johnsen L, Fladby T, Tarkowski A, Trysberg E, Wallin A, Anckarsäter H, Lycke J, Andersen O, Simon AJ, Blennow K, Zetterberg H. Reduced cerebrospinal fluid BACE1 activity in multiple sclerosis. Mult Scler 2009; 15:448-54. [DOI: 10.1177/1352458508100031] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background Cell and animal experiments have shown that β-site APP-cleaving enzyme 1 (BACE1) may be involved in myelination. Objective Here, we assess the association of cerebrospinal fluid (CSF) BACE1 activity with multiple sclerosis (MS). Methods BACE1 activity and levels of secreted amyloid precursor protein (APP) and amyloid-β (Aβ) isoforms were analyzed in CSF from 100 patients with MS and 114 neurologically healthy controls. Patients with systemic lupus erythematosus (SLE), 26 with and 41 without cerebral engagement, were also included to enable comparisons with regards to another autoimmune disease. A subset of patients with MS and controls underwent a second lumbar puncture after 10 years. Results MS patients had lower CSF BACE1 activity than controls ( P = 0.03) and patients with cerebral SLE ( P < 0.001). Patients with cerebral SLE had higher BACE1 activity than any other group ( P < 0.05 for all comparisons). BACE1 activity correlated with the different amyloid markers in all study groups. BACE1 activity decreased over 10 years in the MS group ( P = 0.039) and correlated weakly with clinical disease severity scores in an inverse manner. Conclusions These results suggest an involvement of BACE1 in the MS disease process.
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Axelsson M. Effects of feeding and temperature on gastrointestinal blood flow in the Antarctic fish Pagothenia borchgrevinki; different or just another teleost? Comp Biochem Physiol A Mol Integr Physiol 2008. [DOI: 10.1016/j.cbpa.2008.04.263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Seth H, Sandblom E, Axelsson M. Effects of gastric distension on the cardiovascular system in rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol A Mol Integr Physiol 2007. [DOI: 10.1016/j.cbpa.2007.01.379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Gräns A, Axelsson M, Olsson C, Höjesjö J, Pitsillides K, Cech J. Effects of exercise, feeding, hypoxia and hypercapnia on cardiac output and gut blood flow in white sturgeon (Acipenser transmontanus) using a fully implantable biotelemetry system. Comp Biochem Physiol A Mol Integr Physiol 2007. [DOI: 10.1016/j.cbpa.2007.01.395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Axelsson M, Dang Q, Pitsillides K, Munns S, Hicks J, Kassab GS. A novel, fully implantable, multichannel biotelemetry system for measurement of blood flow, pressure, ECG, and temperature. J Appl Physiol (1985) 2006; 102:1220-8. [PMID: 17122378 DOI: 10.1152/japplphysiol.00887.2006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Biotelemetry provides high-quality data in awake, free-ranging animals without the effects of anesthesia and surgery. Although many biological parameters can be measured using biotelemetry, simultaneous telemetric measurements of pressure and flow have not been available. The objective of this study was to evaluate simultaneous measurements of blood flow, pressure, ECG, and temperature in a fully implantable system. This novel system allows the measurement of up to four channels of blood flow, up to three channels of pressure, and a single channel each of ECG and temperature. The system includes a bidirectional radio-frequency link that allows the implant to send data and accept commands to perform various tasks. The system is controlled by a base station decoder/controller that decodes the data stream sent by the implant into analog signals. The system also converts the data into a digital data stream that can be sent via ethernet to a remote computer for storage and/or analysis. The system was chronically implanted in swine and alligators for up to 5 wk. Both bench and in vivo animal tests were performed to evaluate system performance. Results show that this biotelemetry system is capable of long-term accurate monitoring of simultaneous blood flow and pressure. The system allows, within the room, recordings, since the implant transmission range is between 6 and 10 m, and, with a relay, backpack transmission distance of up to 500 m can be achieved. This system will have significant utility in chronic models of cardiovascular physiology and pathology.
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Sörstedt E, Persson A, Norén B, Björnlert U, Malcherek P, Axelsson M, Johansson J, Smedby O. Computed tomographic colonography: comparison of two workstations. Acta Radiol 2005; 46:671-8. [PMID: 16372685 DOI: 10.1080/02841850500223109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To compare two commercially available computed tomography (CT) colonography systems with respect to interobserver variability, the influence of level of expertise, and the gradual reduction of reviewing time for each system. MATERIAL AND METHODS Two residents and two radiologists using Siemens CTAPP Colography software and Viatronix V3D-Colon software reviewed supine and prone CT acquisitions from 24 patients in a primary 3D endoluminal view. The observers graded each case with respect to technical quality and diagnostic value, assessed the presence of pathology, and indicated the time spent on the viewing. RESULTS Significant differences were found in technical quality (P < 0.001) and diagnostic value (P<0.001) depending on which system was used, with higher scores for the Viatronix software. The agreement between specialists tended to be higher than that between residents (kappa=0.63 (0.30-0.95) vs. kappa=0.51 (0.21-0.81)), and the residents gave significantly (P < 0.001) higher scores of technical quality. However, the level of expertise had no significant impact on the assessments. We noted extensive variability in pathological lesions found by the different observers. The number of findings did not differ between workstations, but the viewers tended to report larger polyp sizes with the Viatronix software. The time needed for viewing decreased significantly from the first to the last examination viewed by each observer. CONCLUSION Both the evaluated systems present trustworthy images of the human colon, but in a primary 3D setting the Viatronix software is favored owing to the user-friendly interface, higher experienced technical quality, and better diagnostic value.
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Sandblom E, Axelsson M. Effects of hypoxia on the venous circulation in rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol A Mol Integr Physiol 2005; 140:233-9. [PMID: 15748864 DOI: 10.1016/j.cbpb.2005.01.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Revised: 12/17/2004] [Accepted: 01/03/2005] [Indexed: 10/25/2022]
Abstract
Hypoxia in fish is generally associated with bradycardia while cardiac output (Q) remains unaltered or slightly increased due to a compensatory increase in stroke volume (SV). Rainbow trout (Oncorhynchus mykiss) were subjected to severe (P(W)O2=7.3+/-0.2 kPa) or mild (P(W)O2=11.5+/-0.2 kPa) hypoxia. Central venous pressure (P(ven)), dorsal aortic pressure (P(da)), heart rate (f(H)) and Q, were recorded in vivo. Both levels of hypoxia triggered a significant increase in P(ven). Severe hypoxia was associated with bradycardia and unaltered Q, whereas mild hypoxia was associated with a small but significant increase in Q and no bradycardia. These findings indicate that an increase in P(ven) promotes an increase in SV during hypoxia. Since mild hypoxia increased P(ven), Q and SV without bradycardia or reduced systemic resistance (R(sys)), we hypothesize that an active increase in venous tone serving to mobilize blood to the central venous compartment in order to increase cardiac preload and consequently SV, is an important cardiovascular trait associated with hypoxia. Pharmacological pre-treatment with prazosin (1 mg kg(-1)) did not conclusively reveal the underlying mechanisms to the observed changes in P(ven). This study discusses the influence of venous pooling, reduced R(sys) and altered venous tone on changes in P(ven) observed during hypoxia.
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Sandblom E, Axelsson M. Baroreflex mediated control of heart rate and vascular capacitance in trout. J Exp Biol 2005; 208:821-9. [PMID: 15755880 DOI: 10.1242/jeb.01470] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe baroreflex was triggered by altering branchial blood pressure with pre-and post-branchial occlusions for 30 s in rainbow trout Oncorhynchus mykiss. The cardiac limb of the baroreflex was monitored by continuous heart rate (fH) measurements. Responses of venous capacitance vessels were assessed, immediately following either occlusion, by measuring mean circulatory filling pressure (MCFP). Arterial responses were evaluated as the change in dorsal aortic blood pressure(Pda) before and after pre-branchial occlusion. In untreated fish pre-branchial occlusion resulted in tachycardia(62.4±2.4 to 69.1±1.7 beats min–1), decreased venous capacitance reflected as an increase in MCFP (0.17±0.03 to 0.27±0.03 kPa) and increased Pda (4.0±0.2 kPa compared to 3.2±0.1 kPa before occlusion). Post-branchial occlusion somewhat reversed the responses since fH decreased(62.4±2.4 to 53.0±3.1 beats min–1), whereas MCFP remained unaltered. Treatment with the α-adrenergic blocker prazosin (1 mg kg–1) increased resting MCFP to 0.33±0.03 kPa and appeared to abolish both venous and arterial responses to branchial occlusion. Subsequent atropine treatment (1.2 mg kg–1) abolished all chronotropic responses. We present for the first time ample evidence for baroreflex-mediated control of cardiovascular homeostasis, including both the chronotropic and the vascular limb of the baroreflex in an unanaesthetized fish. Furthermore, a novel technique to cannulate and occlude the dorsal aorta, using a Fogarty thru-lumen embolectomy catheter, is explained.
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Johnsson M, Axelsson M, Holmgren S. Large veins in the Atlantic cod (Gadus morhua) and the rainbow trout (Oncorhynchus mykiss) are innervated by neuropeptide-containing nerves. ANATOMY AND EMBRYOLOGY 2001; 204:109-15. [PMID: 11556526 DOI: 10.1007/s004290100182] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Previous studies have shown that fish veins are reactive to several hormones known to exist in the fish circulation. Besides this humoral control, another possible means of active regulation of venous return is by autonomic nervous control of venous tone. This study therefore investigated the presence of a perivascular innervation of major veins in the Atlantic cod (Gadus morhua) and the rainbow trout (Oncorhynchus mykiss) using immunohistochemical methods. Histological staining was employed to investigate the smooth muscle distribution in the vessel walls. Vasoactive intestinal polypeptide-immunoreactive nerve fibers were found to be widespread in the venous system of G. morhua and O. mykiss, while pituitary adenylate cyclase-activating polypeptide-immunoreactive fibers were demonstrated in the duct of Cuvier of both species. Fibers containing neurokinin A and/or substance P were found in the duct of Cuvier and the posterior cardinal vein of both species and in the hepatic portal vein of O. mykiss. Calcitonin-gene related peptide-immunoreactive fibers were present in the duct of Cuvier of both species and in the hepatic portal vein of O. mykiss. Galanin-immunoreactive fibers were found in the duct of Cuvier in O. mykiss and in the hepatic portal vein of both species. Co-existence of neuropeptides in the perivascular nerve fibers was investigated by double labelling. Vasoactive intestinal polypeptide/pituitary adenylate cyclase-activating polypeptide-immunoreactive fibers were found in both species. Vasoactive intestinal polypeptide/galanin-immunoreactive fibers and vasoactive intestinal polypeptide/calcitoningene related peptide-immunoreactive fibers were found in G. morhua but not in O. mykiss. This study gives further evidence for an active venoregulation by autonomic nerves in teleost fish.
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Axelsson M, Olsson C, Gibbins I, Holmgren S, Franklin CE. Nitric oxide, a potent vasodilator of the aortic anastomosis in the estuarine crocodile, Crocodylus porosus. Gen Comp Endocrinol 2001; 122:198-204. [PMID: 11316425 DOI: 10.1006/gcen.2001.7627] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of five neuropeptides (CGRP, SOM, SP, NPY, VIP), L-NAME (nitric oxide synthase inhibitor), and adrenaline on the contractile tone of the aortic anastomosis in the estuarine crocodile, Crocodylus porosus, were investigated. None of the neuropeptides, which had previously been found to be present in the aortic anastomosis, had any direct effect on the tension developed by ring preparations. L-NAME itself significantly increased the basal tone of the vascular ring preparations, suggesting a tonic release of nitric oxide in the preparation. Adrenaline produced concentration-dependent vasoconstrictions that were counteracted by profound reflex vasodilatations that were susceptible to blockade by L-NAME. Immunohistochemistry revealed the presence of nitric oxide synthase and tyrosine hydroxylase-containing (indicating the presence of a adrenergic innervation) nerve fibres in the adventitia and adventitio-medial border of the aortic anastomosis. These data demonstrate opposing actions of adrenaline and nitric oxide on the vascular smooth muscle in the anastomosis of the C. porosus. The morphology of the anastomosis, with the extremely thick muscular vessel wall, suggests a sphincter-like function for this vessel that could be controlled mainly by adrenergic and nitrergic mechanisms.
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Axelsson M, Franklin CE. The calibre of the foramen of Panizza in Crocodylus porosus is variable and under adrenergic control. J Comp Physiol B 2001; 171:341-6. [PMID: 11409632 DOI: 10.1007/s003600100183] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The foramen of Panizza is located within the outflow tract of the crocodilian heart, between the left and right aortas. It has been suggested that the foramen of Panizza has a variable calibre, which could explain the profound changes in the distribution of flows and pressure profiles recorded in the right and left aortas. We investigated this possibility using a modified in-situ perfused heart preparation in combination with isolated strip preparations from the outflow tract. In the perfused heart preparation, bolus injections of adrenaline increased the resistance in the foramen of Panizza, indicating a decrease in its diameter. Isolated strip preparations from the outflow tract showed a concentration-dependent increase in tension in response to adrenaline, while vasoactive intestinal polypeptide caused a relaxation in adrenaline pre-contracted strip preparations. We propose that an increase in the diameter of the foramen of Panizza may be important during pulmonary to systemic shunts to allow blood to flow from the left to right aorta (reverse foramen flow) in order to supply the carotid and coronary arteries. During non-shunting conditions, a constricted foramen may prevent excess flow from the right to left aorta during diastole.
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Farrell AP, Thorarensen H, Axelsson M, Crocker CE, Gamperl AK, Cech JJ. Gut blood flow in fish during exercise and severe hypercapnia. Comp Biochem Physiol A Mol Integr Physiol 2001; 128:551-63. [PMID: 11246044 DOI: 10.1016/s1095-6433(00)00335-4] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This paper reviews the effects of exercise and hypercapnia on blood flow to the splanchnic circulation. Brief struggling behaviours are known to decrease blood flow to the gut (GBF). Likewise, prolonged swimming in unfed fish has been shown to reduce GBF in proportion to the increased oxygen uptake. Therefore, the normal postprandial increase in GBF theoretically should be impaired whenever fish are active. However, indirect evidence suggests that GBF is spared to some degree when fed fish swim continuously but at a cost (10-15%) to their critical swimming speed. Severe respiratory acidosis can be created by the new intensive aquaculture settings that use oxygen injection into re-circulated water. The only study so far to examine the effects of severe hypercapnia on GBF and its regulation showed that routine GBF and alpha-adrenergic control of GBF remained normal in unfed white sturgeon (Acipenser transmontanus). However, severe hypercapnia produced a hyperactive state and increased sensitivity of GBF to struggling. As a result, routine GBF was maintained for a short period of time. Thus, environmental changes such as severe hypercapnia can indirectly impact GBF through altered struggling behaviour, but the implications of the overall reduction in GBF to food assimilation have yet to be established.
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Axelsson M, Björnsdottir S, Eksell P, Häggström J, Sigurdsson H, Carlsten J. Risk factors associated with hindlimb lameness and degenerative joint disease in the distal tarsus of Icelandic horses. Equine Vet J 2001; 33:84-90. [PMID: 11191616 DOI: 10.2746/042516401776767502] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aim of this study was to evaluate potential risk factors associated with hindlimb lameness and radiographic signs of degenerative joint disease (DJD) in the distal tarsus in Icelandic horses. The material consisted of riding horses (n = 420) age 6-12 years sired by 17 selected sires representing all major breeding lines, and of riding horses (n = 194) in the same age range sired by other sires. The examination protocol included the following: interview with owners/trainers, assessment of conformation, motion evaluation and radiographic examination. At the interview, data related to factors outside the horse (environmental variables) and data associated directly with the horse (intrinsic variables) were obtained. Data analysis was performed in 2 steps: screening using bivariate analysis, followed by testing with a multivariate logistic regression model. In the multivariate analysis, the factors of sire, age when broken to saddle and stud show participation were strongly associated with the prevalence of lameness. Height at the croup and ability to perform different gaits were also associated with the prevalence of lameness, but to a lesser degree. The risk factors of age, tarsal angle and birthplace were significantly associated with radiographic signs of DJD in the distal tarsus. Neither the variation in applied training intensity, the use of a professional or amateur trainer nor the temperament or front limb action of the individual horse was significantly associated with the prevalence of hindlimb lameness and/or radiographic signs of DJD in the distal tarsus in the Icelandic horse.
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