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Shaw, E. B., Houpt, K. A., & Holmes, D. F. (1988). Body temperature and behaviour of mares during the last two weeks of pregnancy. Equine Vet J, 20(3), 199–202.
Abstract: Average daily core body temperature and behavioural patterns of pregnant mares were studied, in search of definitive signs of parturition within 24 h of the event. Nineteen pony mares were sampled twice daily for core body temperature. A significant temperature drop, averaging 0.1 degrees C (0.2 degrees F) was observed during the day prior to parturition. Between 18.00 h and 06.00 h, during the two weeks before parturition, Thoroughbred and Standardbred mares (n = 52) spent an average 66.8 per cent of their time standing, 27.0 per cent eating, 4.9 per cent lying in sternal recumbency, 1.0 per cent lying in lateral recumbency, and 0.3 per cent walking. On the night before parturition, mares spent significantly less time lying in sternal recumbency than on previous nights and on the night of parturition all behaviour patterns except eating were significantly different from the nights of the two weeks before parturition. There was an increase in walking (5.3 per cent), lying in sternal recumbency (8 per cent) and lying in lateral recumbency (5.3 per cent) whereas standing (53.3 per cent) was decreased. In 58 observed pregnancies, 54 mares (97 per cent) foaled in a recumbent position and 50 mares (86 per cent) foaled between 18.00 h and 06.00 h.
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Duncan, I. J. H., Widowski, T. M., Malleau, A. E., Lindberg, A. C., & Petherick, J. C. (1998). External factors and causation of dustbathing in domestic hens. Behav. Process., 43(2), 219–228.
Abstract: Dustbathing is known to be motivated by complex interactions between internal factors which build up over time and external factors, such as the sight of a dusty substrate. In this study, the effects of other external factors were investigated. Environmental temperature was shown to be important; frequencies of dustbathing were greater when hens were held at 22 than at 10[degree sign]C (P<0.01). In a second experiment, a radiant heat source or a radiant heat+light source, balanced to give the same radiant heat, resulted in more dustbathing behaviour during a 1-h stimulus period than during the same period with no stimulus (P<0.05). Components of dustbathing were increased more by the heat+light stimulus than by the heat stimulus alone (P<0.03). In a third experiment, the amount of dustbathing performed by individual hens in cages with dustbaths was increased by the presence of a group of hens dustbathing in an adjoining pen with a dustbath compared with the amount occurring when the hens were absent from the pen.
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Oliveira-Santos, L. G. R., Machado-Filho, L. C. P., Tortato, M. A., & Brusius, L. (2010). Influence of extrinsic variables on activity and habitat selection of lowland tapirs (Tapirus terrestris) in the coastal sand plain shrub, southern Brazil. Mammalian Biology – Zeitschrift für Säugetierkunde, 75(3), 219–226.
Abstract: The objectives of this research were to: 1. evaluate the circadian activity patterns of lowland tapirs (Tapirus terrestris) throughout the seasons and 2. study the influence of moonlight, temperature and rainfall on the activity patterns and habitat selection of this species, in the coastal sand shrub in southern Brazil. From June 2005 to June 2006, eight tapirs were monitored in a large enclosure containing open and vegetation-covered areas, using four camera traps. Differences in activity patterns within seasons were found. Tapir predominately presented nocturnal-crepuscular activity; however, they differed in the winter, with cathemeral activity patterns. Covered areas were mostly used during periods of extreme temperatures, with less diurnal and more nocturnal activities within these areas, on hotter days. Activity in open areas mainly occurred during periods of intermediate temperatures, both during the day and in the night. Moonlight intensity did not influence nocturnal activities. On days of precipitation of 34 mm or more, there was no record of open-area activities, despite constant activity in covered-area.
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Hughes, K. L., & Sulaiman, I. (1987). The ecology of Rhodococcus equi and physicochemical influences on growth. Vet Microbiol, 14(3), 241–250.
Abstract: Growth of Rhodococcus equi was studied in vitro. Optimal growth occurred under aerobic conditions between pH 7.0 and 8.5, at 30 degrees C. R. equi survived better in a neutral soil (pH 7.3) than it did in two acid soils (pH less than 5.5). It grew substantially better in soils enriched with faeces than in soils alone. Simple organic acids in horse dung, especially acetate and propionate, appear to be important in supporting growth of R. equi in the environment. The ecology of R. equi can be best explained by an environmental cycle allowing its proliferation in dung, influenced by management, grazing behaviour and prevailing climatic conditions. Preventive measures should be aimed at reducing or avoiding focal areas of faecal contamination in the environment.
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Steinhoff, H. J., Schrader, J., & Schlitter, J. (1992). Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals. Biochim Biophys Acta, 1121(3), 269–278.
Abstract: Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed.
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Bayley, P., Martin, S., & Anson, M. (1975). Temperature-jump circular dichroism: observation of chiroptical relaxation processes at millisecond time resolution. Biochem Biophys Res Commun, 66(1), 303–308.
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Balakrishnan, G., Hu, Y., & Spiro, T. G. (2006). Temperature-jump apparatus with Raman detection based on a solid-state tunable (1.80-2.05 microm) kHz optical parametric oscillator laser. Appl Spectrosc, 60(4), 347–351.
Abstract: The operating characteristics of a pulsed (10 ns) tunable near-infrared (NIR) laser source are described for temperature-jump (T-jump) applications. A Q-switched Nd:YLF laser (approximately 10 ns pulses) with a 1 kHz repetition rate is used to pump a potassium titanyl arsenate (KTA) crystal-based optical parametric oscillator (OPO), producing approximately 1 mJ NIR pulses that are tunable (1.80-2.05 microm) across the 1.9 microm vibrational overtone band of water. This T-jump source has been coupled to a deep ultraviolet (UV) probe laser for Raman studies of protein dynamics. T-jumps of up to 30 degrees C, as measured via the O-H stretching Raman band of water, are readily achieved. Application to cytochrome c unfolding is demonstrated.
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Gilmanshin, R., Callender, R. H., & Dyer, R. B. (1998). The core of apomyoglobin E-form folds at the diffusion limit. Nat Struct Biol, 5(5), 363–365.
Abstract: The E-form of apomyoglobin has been characterized using infrared and fluorescence spectroscopies, revealing a compact core with native like contacts, most probably consisting of 15-20 residues of the A, G and H helices of apomyoglobin. Fast temperature-jump, time-resolved infrared measurements reveal that the core is formed within 96 micros at 46 degrees C, close to the diffusion limit for loop formation. Remarkably, the folding pathway of the E-form is such that the formation of a limited number of native-like contacts is not rate limiting, or that the contacts form on the same time scale expected for diffusion controlled loop formation.
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Natalini, C. C., & Robinson, E. P. (2003). Effects of epidural opioid analgesics on heart rate, arterial blood pressure, respiratory rate, body temperature, and behavior in horses. Vet Ther, 4(4), 364–375.
Abstract: Heart rate, arterial blood pressures, respiratory rate, body temperature, and central nervous system excitement were compared before and after epidural administration of morphine (0.1 mg/kg), butorphanol (0.08 mg/kg), alfentanil (0.02 mg/kg), tramadol (1.0 mg/kg), the k-opioid agonist U50488H (0.08 mg/kg), or sterile water using an incomplete Latin square crossover design in five conscious adult horses. Treatments were administered into the first intercoccygeal epidural space. Significant (P <.05) reductions in respiratory rate were detected after epidural administration of morphine, alfentanil, U50488H, and sterile water. Additionally, significant (P <.05) head ptosis was observed within the first hour after administration of morphine, U50488H, and tramadol, but neither of these changes appeared to be of clinical significance. No treatment-related changes in motor activity or behavior were observed.
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Marlin, D. J., Schroter, R. C., White, S. L., Maykuth, P., Matthesen, G., Mills, P. C., et al. (2001). Recovery from transport and acclimatisation of competition horses in a hot humid environment. Equine Vet J, 33(4), 371–379.
Abstract: The aims of the present field-based study were to investigate changes in fit horses undergoing acclimatisation to a hot humid environment and to provide data on which to base recommendations for safe transport and acclimatisation. Six horses (age 7-12 years) were flown from Europe to Atlanta and underwent a 16 day period of acclimatisation. Exercise conditions during acclimatisation (wet bulb globe temperature index 27.6+/-0.0 [mean +/- s.e.]) were more thermally stressful compared with the European climate from which the horses had come (22.0+/-1.8, P<0.001). Following the flight, weight loss was 4.1+/-0.8% bodyweight and took around 7 days to recover. Water intake during the day was significantly increased (P<0.05) compared with night during acclimatisation. Daily mean exercise duration was 72+/-12 min and the majority of work was performed with a heart rate below 120 beats/min. Respiratory rate (fR) was increased (P<0.05) throughout acclimatisation compared with in Europe, but resting morning (AM) and evening (PM) rectal temperature (TREC), heart rate (fC) and plasma volume were unchanged. White blood cell (WBC) count was significantly increased at AM compared with in Europe on Days 4 and 10 of acclimatisation (P<0.01), but was not different by Day 16. In conclusion, horses exposed to hot humid environmental conditions without prior acclimatisation are able to accommodate these stresses and, with appropriate management, remain fit and clinically healthy, without significant risk of heat illness or heat-related disorders, provided they are allowed sufficient time to recover from transport, acclimatisation is undertaken gradually and they are monitored appropriately.
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