| Records |
| Author |
Hagen, S.J.; Eaton, W.A. |
| Title |
Two-state expansion and collapse of a polypeptide |
Type |
Journal Article |
| Year |
2000 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
| Volume |
301 |
Issue |
4 |
Pages  |
1019-1027 |
| Keywords |
Animals; Computer Simulation; Cytochrome c Group/*chemistry/*metabolism; Horses; Kinetics; Lasers; Models, Chemical; Peptides/*chemistry/*metabolism; Protein Conformation; Protein Denaturation; *Protein Folding; Spectrometry, Fluorescence; Temperature; Thermodynamics |
| Abstract |
The initial phase of folding for many proteins is presumed to be the collapse of the polypeptide chain from expanded to compact, but still denatured, conformations. Theory and simulations suggest that this collapse may be a two-state transition, characterized by barrier-crossing kinetics, while the collapse of homopolymers is continuous and multi-phasic. We have used a laser temperature-jump with fluorescence spectroscopy to measure the complete time-course of the collapse of denatured cytochrome c with nanosecond time resolution. We find the process to be exponential in time and thermally activated, with an apparent activation energy approximately 9 k(B)T (after correction for solvent viscosity). These results indicate that polypeptide collapse is kinetically a two-state transition. Because of the observed free energy barrier, the time scale of polypeptide collapse is dramatically slower than is predicted by Langevin models for homopolymer collapse. |
| Address |
Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Building 5, Bethesda, MD, 20892-0520, USA |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-2836 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:10966803 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3790 |
| Permanent link to this record |
| |
|
| |
| Author |
Schwarz, S.; Marr, I.; Farmer, K.; Graf, K.; Stefanski, V.; Krueger, K. |
| Title |
Does Carrying a Rider Change Motor and Sensory Laterality in Horses? |
Type |
Journal Article |
| Year |
2022 |
Publication |
Animals |
Abbreviated Journal |
Animals |
| Volume |
12 |
Issue |
8 |
Pages |
992 |
| Keywords |
laterality; horse; rider; sensory laterality; motor laterality; novel object; side preference |
| Abstract |
Laterality in horses has been studied in recent decades. Although most horses are kept for riding purposes, there has been almost no research on how laterality may be affected by carrying a rider. In this study, 23 horses were tested for lateral preferences, both with and without a rider, in three different experiments. The rider gave minimal aids and rode on a long rein to allow the horse free choice. Firstly, motor laterality was assessed by observing forelimb preference when stepping over a pole. Secondly, sensory laterality was assessed by observing perceptual side preferences when the horse was confronted with (a) an unfamiliar person or (b) a novel object. After applying a generalised linear model, this preliminary study found that a rider increased the strength of motor laterality (p = 0.01) but did not affect sensory laterality (p = 0.8). This suggests that carrying a rider who is as passive as possible does not have an adverse effect on a horse�s stress levels and mental state. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
6667 |
| Permanent link to this record |
| |
|
| |
| Author |
Keiper, R.; Houpt, K. |
| Title |
Reproduction in feral horses: an eight-year study |
Type |
Journal Article |
| Year |
1984 |
Publication |
American journal of veterinary research |
Abbreviated Journal |
Am J Vet Res |
| Volume |
45 |
Issue |
5 |
Pages |
991-995 |
| Keywords |
Abortion, Veterinary/epidemiology; Anestrus; Animal Population Groups/*physiology; Animals; Animals, Wild/*physiology; Birth Rate; Female; Fertility; Horse Diseases/epidemiology; Horses/*physiology; Lactation; Male; Maryland; Pregnancy; *Reproduction; Seasons; Sex Ratio; Virginia |
| Abstract |
The reproductive rate and foal survival of the free-ranging ponies on Assateague Island National Seashore were studied for 8 years, 1975 to 1982. Most (52%) of the 86 foals were born in May, 13% were born in April, 22.6% in June, 10.4% in July, and less than 1% in August and September. The mean foaling rate was 57.1 +/- 3.9% and the survival rate was 88.3 +/- 3.6%. Forty-eight colts and 55 fillies were born (sex ratio 53% female). Mares less than 3 years old did not foal and the foaling rate of 3-year-old mares was only 23%, that of 4-year-old mares was 46%, that of 5-year-old mares was 53%, and 6-year-old mares was 69%. The relatively poor reproduction rate was believed to be a consequence of the stress of lactating while carrying a foal when forage quality on the island was low. The hypothesis was supported by the higher reproductive rate (74.4 +/- 2.4%) of the ponies in the Chincoteague National Wildlife Refuge on the southern part of the island. Their foals are weaned and sold in July each year. Despite the low reproductive rate on Assateague Island National Seashore , the number of ponies increased from 43 to 80, a 90% increase in the 8-year period or greater than 10%/yr. There were 24 deaths and 8 dispersals from the study area. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0002-9645 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:6732036 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
665 |
| Permanent link to this record |
| |
|
| |
| Author |
Permyakov, S.E.; Khokhlova, T.I.; Nazipova, A.A.; Zhadan, A.P.; Morozova-Roche, L.A.; Permyakov, E.A. |
| Title |
Calcium-binding and temperature induced transitions in equine lysozyme: new insights from the pCa-temperature “phase diagrams” |
Type |
Journal Article |
| Year |
2006 |
Publication |
Proteins |
Abbreviated Journal |
Proteins |
| Volume |
65 |
Issue |
4 |
Pages |
984-998 |
| Keywords |
Animals; Apoproteins/chemistry/metabolism; Binding Sites; Calcium/chemistry/*metabolism; Cattle; Edetic Acid/metabolism; Horses/metabolism; Hydrogen-Ion Concentration; Lactalbumin/chemistry/metabolism; Muramidase/*chemistry/*metabolism; Protein Denaturation; Spectrometry, Fluorescence; *Temperature; Thermodynamics; Tryptophan/chemistry/metabolism |
| Abstract |
The most universal approach to the studies of metal binding properties of single-site metal binding proteins, i.e., construction of a “phase diagram” in coordinates of free metal ion concentration-temperature, has been applied to equine lysozyme (EQL). EQL has one relatively strong calcium binding site and shows two thermal transitions, but only one of them is Ca(2+)-dependent. It has been found that the Ca(2+)-dependent behavior of the low temperature thermal transition (I) of EQL can be adequately described based upon the simplest four-states scheme of metal- and temperature-induced structural changes in a protein. All thermodynamic parameters of this scheme were determined experimentally and used for construction of the EQL phase diagram in the pCa-temperature space. Comparison of the phase diagram with that for alpha-lactalbumin (alpha-LA), a close homologue of lysozyme, allows visualization of the differences in thermodynamic behavior of the two proteins. The thermal stability of apo-EQL (transition I) closely resembles that for apo-alpha-LA (mid-temperature 25 degrees C), while the thermal stabilities of their Ca(2+)-bound forms are almost indistinguishable. The native state of EQL has three orders of magnitude lower affinity for Ca(2+) in comparison with alpha-LA while its thermally unfolded state (after the I transition) has about one order lower (K = 15M(-1)) affinity for calcium. Circular dichroism studies of the apo-lysozyme state after the first thermal transition show that it shares common features with the molten globule state of alpha-LA. |
| Address |
Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow region 142290, Russia |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1097-0134 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:17022083 |
Approved |
no |
| Call Number |
|
Serial |
1858 |
| Permanent link to this record |
| |
|
| |
| Author |
Malek, E.A. |
| Title |
The life cycle of Gastrodiscus aegyptiacus (Cobbold, 1876) Looss, 1896 (Trematoda: Paramphistomatidae: Gastrodiscinae) |
Type |
Journal Article |
| Year |
1971 |
Publication |
The Journal of Parasitology |
Abbreviated Journal |
J Parasitol |
| Volume |
57 |
Issue |
5 |
Pages |
975-979 |
| Keywords |
Animals; Bulinus; *Disease Vectors; Ecology; Feces; Female; Horse Diseases/*etiology; Horses; Metamorphosis, Biological; Ovum; Parasite Egg Count; Perissodactyla; Sudan; Trematoda/anatomy & histology/growth & development; Trematode Infections/etiology/*veterinary |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0022-3395 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:5167379 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
2726 |
| Permanent link to this record |
| |
|
| |
| Author |
Mader, D.R.; Price, E.O. |
| Title |
Discrimination learning in horses: effects of breed, age and social dominance |
Type |
Journal Article |
| Year |
1980 |
Publication |
Journal of animal science |
Abbreviated Journal |
J. Anim Sci. |
| Volume |
50 |
Issue |
5 |
Pages |
962-965 |
| Keywords |
Aging; Animals; *Discrimination Learning; Female; Horses/*physiology; *Social Dominance |
| Abstract |
The discrimination learning ability of Quarter Horses and Thoroughbreds was compared by means of visual cues in a three-choice test with food as a reward. Quarter Horses learned significantly faster than Thoroughbreds, and learning progressed more rapidly for both breeds in a second discrimination task. Significant negative correlations were observed between age and rate of learning. Quarter Horses tended to be less reactive than Thoroughbreds, but individual emotional reactivity ratings and learning scores were not correlated. No correlation was found between social dominance and learning scores. Learning studies with horses may provide a better understanding of the behavioral traits that influence trainability in this species. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0021-8812 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:7390949 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
679 |
| Permanent link to this record |
| |
|
| |
| Author |
Santamaria, S.; Bobbert, M.E.; Back, W.; Barneveld, A.; van Weeren, P.R. |
| Title |
Variation in free jumping technique within and among horses with little experience in show jumping |
Type |
Journal Article |
| Year |
2004 |
Publication |
American Journal of Veterinary Research |
Abbreviated Journal |
Am J Vet Res |
| Volume |
65 |
Issue |
7 |
Pages |
938-944 |
| Keywords |
*Acceleration; Analysis of Variance; Animals; Biomechanics; Forelimb/physiology; Gait/*physiology; Hindlimb/physiology; Horses/*physiology; Locomotion/*physiology; Models, Biological; Video Recording |
| Abstract |
OBJECTIVE: To quantify variation in the jumping technique within and among young horses with little jumping experience, establish relationships between kinetic and kinematic variables, and identify a limited set of variables characteristic for detecting differences in jumping performance among horses. ANIMALS: Fifteen 4-year-old Dutch Warmblood horses. PROCEDURE: The horses were raised under standardized conditions and trained in accordance with a fixed protocol for a short period. Subsequently, horses were analyzed kinematically during free jumping over a fence with a height of 1.05 m. RESULTS: Within-horse variation in all variables that quantified jumping technique was smaller than variation among horses. However, some horses had less variation than others. Height of the center of gravity (CG) at the apex of the jump ranged from 1.80 to 2.01 m among horses; this variation could be explained by the variation in vertical velocity of the CG at takeoff (r, 0.78). Horses that had higher vertical velocity at takeoff left the ground and landed again farther from the fence, had shorter push-off phases for the forelimbs and hind limbs, and generated greater vertical acceleration of the CG primarily during the hind limb push-off. However, all horses cleared the fence successfully, independent of jumping technique. CONCLUSIONS AND CLINICAL RELEVANCE: Each horse had its own jumping technique. Differences among techniques were characterized by variations in the vertical velocity of the CG at takeoff. It must be determined whether jumping performance later in life can be predicted from observing free jumps of young horses. |
| Address |
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 12, NL-3584 CM Utrecht, The Netherlands |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0002-9645 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:15281652 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3772 |
| Permanent link to this record |
| |
|
| |
| Author |
Sabattini, M.S.; Monath, T.P.; Mitchell, C.J.; Daffner, J.F.; Bowen, G.S.; Pauli, R.; Contigiani, M.S. |
| Title |
Arbovirus investigations in Argentina, 1977-1980. I. Historical aspects and description of study sites |
Type |
Journal Article |
| Year |
1985 |
Publication |
The American Journal of Tropical Medicine and Hygiene |
Abbreviated Journal |
Am J Trop Med Hyg |
| Volume |
34 |
Issue |
5 |
Pages |
937-944 |
| Keywords |
Animals; Arbovirus Infections/*epidemiology/microbiology; Arboviruses; Argentina; Birds; Cattle; Child; Climate; Ecology; Encephalitis Virus, St. Louis; Encephalitis Virus, Venezuelan Equine; Encephalitis Virus, Western Equine; Encephalitis, St. Louis/epidemiology/microbiology; Encephalomyelitis, Equine/epidemiology/microbiology/veterinary; Encephalomyelitis, Venezuelan Equine/epidemiology/microbiology/veterinary; Geography; Horse Diseases/epidemiology/microbiology; Horses/microbiology; Humans |
| Abstract |
This is the introductory paper to a series on the ecology of arboviruses in Argentina. Epizootics of equine encephalitis have occurred since at least 1908, principally in the Pampa and Espinal biogeographic zones, with significant economic losses; human cases of encephalitis have been rare or absent. Both western equine and eastern equine encephalitis viruses have been isolated from horses during these epizootics, but the mosquitoes responsible for transmission have not been identified. A number of isolations of Venezuelan equine encephalitis (VEE) virus were reported between 1936 and 1958 in Argentina, but the validity of these findings has been seriously questioned. Nevertheless, serological evidence exists for human infections with a member of the VEE virus complex. Serological surveys conducted in the 1960s indicate a high prevalence of infection of humans and domestic animals with St. Louis encephalitis (SLE), and 2 SLE virus strains have been isolated from rodents. Human disease, however, has rarely been associated with SLE infection. Only 7 isolations of other arboviruses have been described (3 of Maguari, 1 of Aura, 2 of Una, and 1 of an untyped Bunyamwera group virus). In 1977, we began longitudinal field studies in Santa Fe Province, the epicenter of previous equine epizootics, and in 1980 we extended these studies to Chaco and Corrientes provinces. The study sites are described in this paper. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0002-9637 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:4037184 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
2685 |
| Permanent link to this record |
| |
|
| |
| Author |
Yokoyama, S.; Radlwimmer, F.B. |
| Title |
The molecular genetics of red and green color vision in mammals |
Type |
Journal Article |
| Year |
1999 |
Publication |
Genetics |
Abbreviated Journal |
Genetics |
| Volume |
153 |
Issue |
2 |
Pages |
919-932 |
| Keywords |
Amino Acid Sequence; Animals; Base Sequence; COS Cells; Cats; Color Perception/*genetics; DNA Primers; Deer; Dolphins; *Evolution, Molecular; Goats; Guinea Pigs; Horses; Humans; Mammals/*genetics/physiology; Mice; Molecular Sequence Data; Opsin/biosynthesis/chemistry/*genetics; *Phylogeny; Rabbits; Rats; Recombinant Proteins/biosynthesis; Reverse Transcriptase Polymerase Chain Reaction; Sciuridae; Sequence Alignment; Sequence Homology, Amino Acid; Transfection |
| Abstract |
To elucidate the molecular mechanisms of red-green color vision in mammals, we have cloned and sequenced the red and green opsin cDNAs of cat (Felis catus), horse (Equus caballus), gray squirrel (Sciurus carolinensis), white-tailed deer (Odocoileus virginianus), and guinea pig (Cavia porcellus). These opsins were expressed in COS1 cells and reconstituted with 11-cis-retinal. The purified visual pigments of the cat, horse, squirrel, deer, and guinea pig have lambdamax values at 553, 545, 532, 531, and 516 nm, respectively, which are precise to within +/-1 nm. We also regenerated the “true” red pigment of goldfish (Carassius auratus), which has a lambdamax value at 559 +/- 4 nm. Multiple linear regression analyses show that S180A, H197Y, Y277F, T285A, and A308S shift the lambdamax values of the red and green pigments in mammals toward blue by 7, 28, 7, 15, and 16 nm, respectively, and the reverse amino acid changes toward red by the same extents. The additive effects of these amino acid changes fully explain the red-green color vision in a wide range of mammalian species, goldfish, American chameleon (Anolis carolinensis), and pigeon (Columba livia). |
| Address |
Department of Biology, Syracuse University, Syracuse, New York 13244, USA. syokoyam@mailbox.syr.edu |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0016-6731 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:10511567 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
4063 |
| Permanent link to this record |
| |
|
| |
| Author |
Barros, A.T. |
| Title |
Seasonality and relative abundance of Tabanidae (Diptera) captured on horses in the Pantanal, Brazil |
Type |
Journal Article |
| Year |
2001 |
Publication |
Memorias do Instituto Oswaldo Cruz |
Abbreviated Journal |
Mem Inst Oswaldo Cruz |
| Volume |
96 |
Issue |
7 |
Pages |
917-923 |
| Keywords |
Animals; Brazil; Climate; Diptera/classification/*physiology; Ecology; Horses/*parasitology; Population Dynamics; Seasons; Species Specificity |
| Abstract |
Once a month, from June 1992 to May 1993, collections of tabanids on horse were conducted in the Nhecolandia, Pantanal State of Mato Grosso do Sul, Brazil. Tabanid catches using hand nets were conducted from sunrise to sunset at grassland and cerradao (dense savanna) habitats. A total of 3,442 tabanids from 21 species,12 genera, and 3 subfamilies were collected. Although species abundance varied seasonally depending on habitat, no habitat specificity was observed for the most abundant species. In the grassland, 1,625 (47.2%) tabanids belonging to 19 species were collected, while 1,817 (52.8%) tabanids from 17 species were caught in the cerradao. The number of tabanid species varied from 7 during winter (July/August) to 15 in the spring (October). Tabanus importunus (56%) was the most abundant species, followed by T. occidentalis (8.2%), and T. claripennis (8.1%). The tabanid peak, in October, coincided with the beginning of the rainy season. The population peak of most species, including those with higher vector potential, suggests that the rainy season can be considered as the period of potentially higher risk of mechanical transmission of pathogens by tabanids to horses in the region. |
| Address |
Embrapa Pantanal, 79320-900 Corumba, MS, Brasil. thadeu@cpap.embrapa.br |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0074-0276 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:11685255 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
2644 |
| Permanent link to this record |
