Does horse temperament influence horse-rider cooperation?

Cooperation between rider and horse is of major importance in equitation. A balanced team of horse and rider improves (sport) performances and welfare aspects by decreasing stress, frustration, risks of injuries, and accidents. Important features affecting the cooperation are the physical skills, knowledge, and personality of the rider on one hand and the temperament, experience, and physical abilities of the horse on the other. A study with 16 riders and 16 warm-blood riding horses tested the effect of personality of riders and temperament of horses on cooperation between riders and horses. More emotionally reactive horses showed more evasive behavior during riding. Riders preferred to ride those horses who were assessed by the riders as being attentive to the rider's aid. The frequency of evasive behaviors during riding--as assessed by riders, in contrast to the assessments made by an external judge--influenced the cooperation between rider and horse. On average, a rider's personality did not affect the cooperation between rider and horse; however, it is suggested that a rider's personality does affect the cooperation with more emotionally reactive horses.     

Assessing the rider's seat and horse's behavior: difficulties and perspectives

A correct seat and position are the basis for a good performance in horseback riding. This study aimed to measure deviations from the correct seat, test a seat improvement program (dismounted exercises), and investigate whether horse behavior was affected by the rider's seat. Five experienced trainers defined 16 seat deviations and scored the occurrence in 20 riders in a dressage test. Half the riders then carried out an individual training program; after 9 weeks, riders were again scored. The study took no video or heart-rate recordings of horses and riders. Panel members did not agree on the deviations in the rider's seat; the study detected no differences-with the exception of improvement of backward-tilted pelvis-between the groups. Horse behavior, classified as "evasive," increased; horse heart rate decreased in the experimental group. Heart rates of riders in both groups decreased. Seven of 9 riders in the experimental group had the impression that the exercises improved their riding performance. There is a clear need to develop a robust system that allows trainers to objectively evaluate the rider's seat.     

Immunoglobulin free light chains are increased in hypersensitivity pneumonitis and idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF), a devastating lung disorder of unknown aetiology, and chronic hypersensitivity pneumonitis (HP), a disease provoked by an immunopathologic reaction to inhaled antigens, are two common interstitial lung diseases with uncertain pathogenic mechanisms. Previously, we have shown in other upper and lower airway diseases that immunoglobulin free light chains (FLCs) are increased and may be involved in initiating a local inflammation. In this study we explored if such a mechanism may also apply to HP and IPF.

Methods

In this study we examined the presence of FLC in serum and BAL fluid from 21 IPF and 22 HP patients and controls. IgG, IgE and tryptase concentrations were measured in BAL fluid only. The presence of FLCs, plasma cells, B cells and mast cells in lung tissue of 3 HP and 3 IPF patients and 1 control was analyzed using immunohistochemistry.

Results

FLC concentrations in serum and BAL fluid were increased in IPF and HP patients as compared to control subjects. IgG concentrations were only increased in HP patients, whereas IgE concentrations were comparable to controls in both patient groups. FLC-positive cells, B cells, plasma cells, and large numbers of activated mast cells were all detected in the lungs of HP and IPF patients, not in control lung.

Conclusion

These results show that FLC concentrations are increased in serum and BAL fluid of IPF and HP patients and that FLCs are present within affected lung tissue. This suggests that FLCs may be involved in mediating pathology in both diseases.     

Effects of intermittent lighting on sleep and activity in the domestic hen

This experiment deals with the effects of two different light-dark regimes on general activity, behavioural patterns and sleep in domestic hens (Gallus domesticus). The light-dark schemes were composed of a traditional 14 h light-10h dark period and the Biomittent Lighting Program (BMLP), which consists of only 15 min light during every hour of the traditional 14 h photoperiod. Although it was found that hens are more active during the day than during the night, they were much less active under the BMLP-regime compared to the traditional regime. More specifically, there is considerable lowering of their activities during the dark portions of the day; behavioural observations revealed that they spend these periods not with resting behaviour, but with passive wakefulness. They more or less concentrate their daily activities during the 15-min light periods. Under the night period of the BMLP-regime, hens appeared to be more restless. Sleep recordings showed that sleep tended to decrease in favour of more drowsiness.

It was concluded that circadian rhythmicity of the hens is maintained under both lighting schemes, although the BMLP-regime imposes more passive wakefulness during the day and slightly more activity during the night.     

Lysozyme‐responsive polymer systems for detection of infection

There is a strong need for new point‐of‐care systems for the detection of wound infection. Overseen infections in chronic wounds induce severe complications, such as delayed healing and high risks for the patients, while time‐consuming common gold and silver standard methods for infection assessment cannot be implemented in home care units. This study demonstrates for the first time the between correlation of lysozyme activity and silver‐standard microbiological evaluation of wounds. Significantly higher (eightfold increase; p < 0.001) lysozyme activity in infected wounds was in accordance with increasing bacterial burden of infected wound fluids. Moreover, a two‐layer membrane‐based test system was developed providing visible results on infection in a short time (30 min) while avoiding any intermediate steps such as centrifugation. In the first layer of the system, a size exclusion membrane (1.2–8 μm cut‐off) retained labeled peptidoglycane while allowing only smaller fragments resulting from lysozyme hydrolysis to pass through. These fragments were then captured in a second layer, an anion‐exchanging diethylaminoethyl cellulose membrane, resulting in clearly visible color changes. Colorimetric measurements demonstrated significant differences (p < 0.001) and sixfold higher delta E values between infected and noninfected wound fluids. This system allows a quick and straightforward determination of the status of a wound. The colorimetric readout indicates the increased lysozyme activity in infected wound fluid.     

Site-directed mutagenesis of the Nidovirus replicative endoribonuclease NendoU exerts pleiotropic effects on the arterivirus life cycle

The highly conserved NendoU replicative domain of nidoviruses (arteriviruses, coronaviruses, and roniviruses) belongs to a small protein family whose cellular branch is prototyped by XendoU, a Xenopus laevis endoribonuclease involved in nucleolar RNA processing. Recently, sequence-specific in vitro endoribonuclease activity was demonstrated for the NendoU-containing nonstructural protein (nsp) 15 of several coronaviruses. To investigate the biological role of this novel enzymatic activity, we have characterized a comprehensive set of arterivirus NendoU mutants. Deleting parts of the NendoU domain from nsp11 of equine arteritis virus was lethal. Site-directed mutagenesis of conserved residues exerted pleiotropic effects. In a first-cycle analysis, replacement of two conserved Asp residues in the C-terminal part of NendoU rendered viral RNA synthesis and virus production undetectable. In contrast, mutagenesis of other conserved residues, including two putative catalytic His residues that are absolutely conserved in NendoU and cellular homologs, produced viable mutants displaying reduced plaque sizes (20 to 80% reduction) and reduced yields of infectious progeny of up to 5 log units. A more detailed analysis of these mutants revealed a moderate reduction in RNA synthesis, with subgenomic RNA synthesis consistently being more strongly affected than genome replication. Our data suggest that the arterivirus nsp11 is a multifunctional protein with a key role in viral RNA synthesis and additional functions in the viral life cycle that are as yet poorly defined.     

Egg-laying behaviour and nest-site selection of domestic hens kept in small floor-pens

The development of egg-laying behaviour and nest-site choice is described in seven flocks of White Leghorn hens housed in small floor-pens. Special interest was directed towards social dominance and the effect of the presence of a cock on the hen's nest-site choice. In the weeks before the hens came into lay, they frequently examined the nests. Nest-entries only occurred some days before, or in the hours preceding, the first oviposition. Some hens were very conservative in their nest-site choice within clutches as well as between clutches. A number of hens only persevered in their nest-site choice within clutches, while a third category did not show any consistency in their choices. Individual hens were consistent in using either the floor or a nest-box as a nesting site.No relationship was found between social status and nest-site choice, nor between social status and floor-laying. Some evidence was provided that the presence of a cock could reduce the number of floor-eggs in a flock provided with roll-away boxes.It is postulated that the nest-examinations in the weeks before laying may serve for the selection of a suitable nest-site.     

Evidence for balancing selection acting on KIR2DL4 genotypes in rhesus macaques of Indian origin

The interaction of killer-cell immunoglobulin-like receptors (KIR) and their respective major histocompatibility complex (MHC) ligands can alter the activation state of the natural killer (NK) cell. In both humans and rhesus macaques, particular types of non-classical MHC class I molecules are predominantly expressed on the trophoblast. In humans, human leukocyte antigen G has been demonstrated to act as a ligand for KIR2DL4, present on all NK cells, whereas Mamu-AG may execute a similar function in rhesus macaques. During primate evolution, orthologues of KIR2DL4 appear to have been highly conserved, suggesting strong purifying selection. A cohort of 112 related and unrelated rhesus macaques of mostly Indian origin were selected to study their KIR2DL4 genes for the occurrence of polymorphism. Comparison of the proximal region provided evidence for strong conservative selection acting on the exons encoding the Ig domains. As is found in humans, in the Indian rhesus macaque population, two different KIR2DL4 entities are encountered, which differ for their intra-cellular signalling motifs. One genotype contains a complex mutation in the distal region of exon 9, which negates a serine/threonine kinase site. Furthermore, both allelic entities are present in a distribution, which suggests that balancing selection is operating on these two distinct forms of KIR2DL4. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Learning performances in young horses using two different learning tests

To achieve optimal performance in equine sports as well as in leisure not only the physical abilities of the horse should be considered, but also the horse’s personality. Besides temperamental aspects, like emotionality, or the horse’s reactivity towards humans in handling situations, the learning ability of the horse is another relevant personality trait. To study whether differences in learning performance are consistent over time and whether individual learning performance differs between learning tests or is affected by emotionality, 39 young horses (Dutch Warmblood) were tested repeatedly in two learning tests. An aversive stimulus (AS) was used in one learning test (the avoidance learning test) and a reward was used in the other learning test (the reward learning test). During both learning tests behaviour as well as heart rate were measured. Each test was executed four times, twice when horses were 1 year of age, and twice when they were 2 years of age. Half of the horses received additional physical training from 6 months onwards. In both tests horses could be classified as either performers, i.e. completing the daily session, or as non-performers, i.e. returning to the home environment without having completed the daily session. There were some indications that emotionality might have caused non-performing behaviour, but these indications are not convincing enough to exclude other causes. Furthermore, there seem to be no simple relationships between measures of heart rate, behavioural responses putatively related to emotionality and learning performance. Horses revealed consistent individual learning performances within years in both tests, and in the avoidance learning test also between years. There was no significant correlation between learning performances in the avoidance learning test and the learning performances in the reward learning test. It is concluded that individual learning abilities are consistent over a short time interval for an avoidance learning test and a reward learning test and over a longer time for the avoidance learning test. Furthermore, results indicate that some horses perform better when they have to learn to avoid an aversive stimulus while others perform better when they are rewarded after a correct response. It is suggested that these differences may be relevant to design optimal individual training programmes and methods.