bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hidden genetic variation evolves with ecological specialization: the genetic basis of phenotypic plasticity in Arctic charr ecomorphs
Authors: Küttner Eva , Parsons Kevin J. , Easton Anne A. , Skúlason Skuli , Danzmann Roy G. , Ferguson Moira M. 
Published: June 2014

SUMMARYThe genetic variance that determines phenotypic variation can change across environments through developmental plasticity and in turn play a strong role in evolution. Induced changes in genotype–phenotype relationships should strongly influence adaptation by exposing different sets of heritable variation to selection under some conditions, while also hiding variation. Therefore, the heritable variation exposed or hidden from selection is likely to differ among habitats. We used ecomorphs from two divergent populations of Arctic charr (Salvelinus alpinus) to test the prediction that genotype–phenotype relationships would change in relation to environment. If present over several generations this should lead to divergence in genotype–phenotype relationships under common conditions, and to changes in the amount and type of hidden genetic variance that can evolve. We performed a common garden experiment whereby two ecomorphs from each of two Icelandic lakes were reared under conditions that mimicked benthic and limnetic prey to induce responses in craniofacial traits. Using microsatellite based genetic maps, we subsequently detected QTL related to these craniofacial traits. We found substantial changes in the number and type of QTL between diet treatments and evidence that novel diet treatments can in some cases provide a higher number of QTL. These findings suggest that selection on phenotypic variation, which is both genetically and environmentally determined, has shaped the genetic architecture of adaptive divergence in Arctic charr. However, while adaptive changes are occurring in the genome there also appears to be an accumulation of hidden genetic variation for loci not expressed in the contemporary environment.
Significance of longitudinal changes in the default‐mode network for cognitive recovery after stroke
Authors: Park Ji‐Young , Kim Yun‐Hee , Chang Won Hyuk , Park Chang‐hyun , Shin Yong‐Il , Kim Sung Tae , Pascual‐Leone Alvaro 
Published: June 2014

AbstractAlthough a considerable number of patients suffer from cognitive impairments after stroke, the neural mechanism of cognitive recovery has not yet been clarified. Repeated resting‐state functional magnetic resonance imaging (fMRI) was used in this study to examine longitudinal changes in the default‐mode network (DMN) during the 6 months after stroke, and to investigate the relationship between DMN changes and cognitive recovery. Out of 24 initially recruited right‐hemispheric stroke patients, 11 (eight males, mean age 55.7 years) successfully completed the repeated fMRI protocol. Patients underwent three fMRI sessions at 1, 3 and 6 months after stroke. Their DMNs were analysed and compared with those of 11 age‐matched healthy subjects (nine males, mean age 56.2 years). Correlations between DMN connectivity and improvement of the cognitive performance scores were also assessed. The stroke patients were found to demonstrate markedly decreased DMN connectivity of the posterior cingulate cortex, precuneus, medial frontal gyrus and inferior parietal lobes at 1 month after stroke. At 3 months after stroke, the DMN connectivity of these brain areas was almost restored, suggesting that the period is critical for neural reorganization. The DMN connectivity of the dorsolateral prefrontal cortex in the contralesional hemisphere showed a significant correlation with cognitive function recovery in stroke patients, and should be considered a compensatory process for overcoming cognitive impairment due to brain lesion. This is the first longitudinal study to demonstrate the changes in DMN during recovery after stroke and the key regions influencing cognitive recovery.
Impaired ambulation and steroid therapy impact negatively on bone health in multiple sclerosis
Authors: Tyblova M. , Kalincik T. , Zikan V. , Havrdova E. 
Published: June 2014

Background and purposeThe prevalence of osteopenia and osteoporosis is higher amongst patients with multiple sclerosis in comparison with the general population. In addition to the general determinants of bone health, two factors may contribute to reduced bone mineral density in multiple sclerosis: physical disability and corticosteroid therapy. The aim of this study was to examine the effect of physical disability and steroid exposure on bone health in weight‐bearing bones and spine and on the incidence of low‐trauma fractures in multiple sclerosis.MethodsIn this retrospective analysis of prospectively collected data, associations between bone mineral density (at the femoral neck, total femur and the lumbar spine) and its change with disability or cumulative steroid dose were evaluated with random‐effect models adjusted for demographic and clinical determinants of bone health. The incidence of low‐trauma fractures during the study follow‐up was evaluated with Andersen−Gill models.ResultsOverall, 474 and 438 patients were included in cross‐sectional and longitudinal analyses (follow‐up 2347 patient‐years), respectively. The effect of severely impaired gait was more apparent in weight‐bearing bones (P ≤ 10−15) than in spine (P = 0.007). The effect of cumulative steroid dose was relatively less pronounced but diffuse (P ≤ 10−4). Risk of low‐trauma fractures was associated with disability (P = 0.02) but not with cumulative steroid exposure and was greater amongst patients with severely impaired gait (annual risk 3.5% vs. 3.0%). Synergistic effects were found only between cumulative steroid dose in patients ambulatory without support (P = 0.02).ConclusionsBone health and the incidence of low‐trauma fractures in multiple sclerosis are more related to impaired gait than to extended corticosteroid therapy.
Proximal attrition facets: morphometric, demographic, and aging characteristics
Authors: Sarig Rachel , Hershkovitz Israel , Shvalb Nir , Sella‐Tunis Tatiana , May Hila , Vardimon Alexander D. 
Published: June 2014

Although interproximal attrition is considered to be limited in modern populations, it has important clinical implications. However, in contrast to occlusal attrition, proximal attrition receives limited scientific attention. The main purpose of the current study was to fill this void. Seven‐hundred and sixty‐five teeth were collected from 255 skulls of subjects 18–75 yr of age. For each individual, three mandibular teeth (the first and second premolars and the first molar) were examined for proximal attrition facets (PAFs). The results provide detailed information on the size, shape, and location of the facets according to age cohort, gender, and ethnicity. The validity of the method used to measure the facets was also examined. The major findings were as follows: PAFs are usually located on the upper half of the crown proximal aspect; in each tooth, the mesial facet is more lingually positioned and the distal facet is more buccally positioned; the majority of the facets are subrectangular in shape; the size of the facets tends to increase in an anteroposterior direction (from premolars to molars); and facet size and location are age‐ and sex‐dependent and ethnicity‐independent. It is our recommendation that dentists bear in mind that interproximal attrition is a dynamic, long‐term process and needs to be considered in many clinical scenarios.
Environmental dependency of amphibian–ranavirus genotypic interactions: evolutionary perspectives on infectious diseases
Authors: Echaubard Pierre , Leduc Joel , Pauli Bruce , Chinchar V. Gregory , Robert Jacques , Lesbarrères David 
Published: June 2014

AbstractThe context‐dependent investigations of host–pathogen genotypic interactions, where environmental factors are explicitly incorporated, allow the assessment of both coevolutionary history and contemporary ecological influences. Such a functional explanatory framework is particularly valuable for describing mortality trends and identifying drivers of disease risk more accurately. Using two common North American frog species (Lithobates pipiens and Lithobates sylvaticus) and three strains of frog virus 3 (FV3) at different temperatures, we conducted a laboratory experiment to investigate the influence of host species/genotype, ranavirus strains, temperature, and their interactions, in determining mortality and infection patterns. Our results revealed variability in host susceptibility and strain infectivity along with significant host–strain interactions, indicating that the outcome of an infection is dependent on the specific combination of host and virus genotypes. Moreover, we observed a strong influence of temperature on infection and mortality probabilities, revealing the potential for genotype–genotype–environment interactions to be responsible for unexpected mortality in this system. Our study thus suggests that amphibian hosts and ranavirus strains genetic characteristics should be considered in order to understand infection outcomes and that the investigation of coevolutionary mechanisms within a context‐dependent framework provides a tool for the comprehensive understanding of disease dynamics.
Candidate Gene SNP Associations With Fat‐Free Mass (FFM) Measurements in Horses‐In‐Training
Authors: Katz L , McGivney B , Fonseca R , Hill E 
Published: June 2014

IntroductionBody composition including percentage of fat, fat mass and fat‐free mass (FFM) is an important consideration for athletes. An evaluation of FFM in racehorses concluded that racing performance is positively correlated with FFM both pre‐ and post‐training. Athletic performance is influenced by interactions among the environment and genes that influence anatomical, metabolic and physiological traits relevant to exercise. The aim of this study was to determine the effects of genetic variation in six candidate genes with functions in growth and metabolism (IL1RA, PTPN1, MC3R, IGF1, LEPR and MSTN) on FFM in Thoroughbreds.MethodsFFM was calculated from rump fat thickness measured ultrasonographically in 110 two‐year‐old Thoroughbred horses‐in‐training in the same yard after two (T2) and eight (T8) months of training. Twenty‐one SNPs in six genes were selected from the EquCab2.0 SNP database and were genotyped for all horses using custom Sequenom SNP genotyping assays. Quantitative tests of association were performed between SNPs and FFM at T2 and T8, and the FFM ratio between the two time points (T2 : T8) using PLINK software.ResultsTwo SNPs in both the IGF1 (Insulin‐Like Growth Factor 1) and PTPN1 (Protein Tyrosine Phosphatase, Non‐Receptor Type 1) genes were significantly associated with FFM (T2) (P<0.05). The two IGF1 SNPs and two LEPR (Leptin Receptor) gene SNPs were significantly associated with FFM (T8) (P<0.05). One LEPR SNP was significantly (P<0.005) associated with changes in FFM (T2 : T8).ConclusionsThese results suggest a genetic contribution to FFM variation in Thoroughbreds. Further validation will determine whether these SNPs may be used to predict the effects of training on FFM.Ethical Animal ResearchInstitutional Animal Research Ethics Committee approval was obtained. Explicit owner informed consent for participation in this study is not stated. Sources of funding: The study was funded by a Science Foundation Ireland, President of Ireland Young Researcher Award (04‐YI1‐ B539). Competing interests: Dr Hill is a co‐founder and Chairman of Equinome Ltd.
Where Do the Cold Blood Breeds Come from and Where Does Polysaccharide Storage Myopathy Fit in?
Authors: van den Hoven R 
Published: June 2014

IntroductionMyopathy associated with a gain‐of‐ function mutation in the GYS1 gene is known in Quarter Horses and cold blood breeds. The mutation occurred between the collapse of the Roman Empire (500 AD) and the upsurge of Carolinian Reign (800 AD). The aim of this review is to reconstruct the development of the cold blood (brachimorph) breeds in Europe using existing literature.MethodsLiterature reviewResultsAlthough archaeological evidence indicates the existence of a mesomorph horse (Cob) type in the early Iron Age, real cold blood breeding only started after 1750. The demand for draught power in the early Industrial Revolution resulted in a large population of cold bloods from 1850 onwards. In Roman times, the huge ugly horses from Thrace were known as “easy keepers” and Ardennes might have been the first land races carrying the GYS1 mutation. Hunnish horses might have contributed to the prototype cold bloods as well. With mtDNA, Y‐chromosome polymorphism, satellite markers and SNP genotyping some indication from where ancestors of particular breeds originate was obtained. Most phylogenetic trees place cold blood breeds, including Fell ponies, Haflinger and Friesian in a clearly different cluster than ponies, saddle horses and Thoroughbreds. Fjords and Mongolian horses are in neighbouring clusters. Since the last 200 years, genetic bottlenecks and the popular sire phenomenon could have caused high GYS1 H allele frequencies in many continental cold blood breeds.ConclusionsCold blood breeds and the GYS1 mutation likely trace back to the mesomorph tough, easily satisfied horse types from Eastern Europe and central Asia.Ethical Animal ResearchNo animals were used in the study. Sources of funding: none. Competing interests: none.
Probability of Jumping Success of Young Brazilian Sport Horses Assessed Via Kinematic Analysis
Authors: Godoi FN , Bergmann JA , Almeida FQ , Toral FL , Miranda AL 
Published: June 2014

IntroductionThe study of kinematic patterns of young jumping horses can help to improve selection. This study was carried out to predict free jumping success of young horses using logistic regression to model jumping kinematic variables.Methods108 untrained young Brazilian Sport Horses of both genders were studied. Reflective skin markers were used to identify anatomical reference points. Five free jumps over a vertical obstacle (with a height of 60, 80 and 105 cm for age classes 22–25, 29–32 and 36–39 months, respectively) were recorded. A 100 Hz camera was used, and images were analyzed using Simi Reality Motion Systems®. Successful (n = 1,030) and unsuccessful (n = 200) jumps were analyzed and the following kinematic variables were preselected by principal components analysis and then used as independent variables: last stride length prior to jumping, jumping velocity, take‐off distance, withers displacement at jumping, forelimb height at jumping, vertical distance between scapulohumeral and metacarpophalangeal joints, scapulohumeral, radial‐metacarpal, tibiometatarsal and withers‐fetlock angles.ResultsThe effects of take‐off distance, forelimb height at jumping and jumping velocity on the jumping result were significant (P = 0.0091). An increment of one centimeter in take‐off distance and forelimb height led to an increase in the probability of success by 2.6% and 10.6%, respectively. An increase of one meter per second in jumping velocity led to a reduction in the probability of success by 27.8%.ConclusionsJumping success is influenced by take‐off distance, jumping velocity and forelimb flexibility. Selection of young horses for superior jumping capacity can be aided by kinematic analysis, which may shorten training time and improve performance.Ethical Animal ResearchThe research was approved by UFMG Ethics Committee on Animal Research: 267/2008. Explicit owner informed consent for participation in this study is not stated. Sources of funding: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo à Pesquisa do estado de Minas Gerais (FAPEMIG). Competing interests: none.
The Effects of Chiropractic Treatment on The Range of Motion of the Carpus and Tarsus of Horses
Authors: Guest J , Cunliffe C 
Published: June 2014

IntroductionThe use of complementary therapies in both humans and animals has grown over the past decade. Equine back problems are more frequently reported as a contributing factor to poor performance, and back dysfunction affects limb kinematics. This study aimed to determine if (McTimoney) chiropractic treatment has an effect on the range of motion (ROM) of the carpus and tarsus.MethodsHemispherical 35 mm markers were applied to 7 anatomical landmarks of both forelimbs and hindlimbs of 10 sound, healthy horses from the same riding school with similar workload. The treatment group (n = 5) received (McTimoney) chiropractic treatment for the neck, back, pelvis and front feet. Two digital video recorders set 5.5 m from subjects, filming both sides concurrently, collected 2‐D kinematic data at walk and trot, 1 day before, and 2 hrs and 7 days after treatment. Data was analysed using Kinovea software, minimum and maximum joint angles were measured and ROM calculated. Statistical analyses included two‐way ANOVA, Student's t‐test and symmetry indices.ResultsA significant increase in right‐side ROM for carpus at walk (+4.0 deg, p = 0.04) and trot (+5.2 deg, p = 0.02) was noted in the treated compared to the non‐treated group. For the treatment group, there was a significant change in carpus ROM asymmetry from left towards neutral at walk (P = 0.004) and trot (P = 0.04). Tarsus ROM asymmetry change from left towards neutral was significant (P = 0.02) at trot. No changes were observed in the control group.ConclusionsThese results support the hypothesis that (McTimoney) chiropractic treatment may improve the symmetry of tarsus and carpus ROM of horses. Further research is needed to assess the clinical relevance of these effects.Ethical Animal ResearchProcedures were reviewed by the McTimoney Chiropractic College Ethical Review Committee. Explicit owner informed consent for participation in this study is not stated. Sources of funding: none. Competing interests: none.
The Effect of Centre of Mass Location on Pitching Moments in Trotting Horses
Authors: Hobbs S , Richards J , Clayton H 
Published: June 2014

IntroductionThe diagonal limb support pattern at trot provides pitch and roll stability, controlled by regulating pitching moments about the centre of mass (COM). Correct COM location is critical in calculation of pitching moments, as COM location influences the contribution of loading in the fore and hindlimbs. This study examined the effect of COM location on pitching moments in trotting horses and explored how COM location could influence balance.MethodsKinematic (120 Hz) and GRF (4 force plates, 960 Hz) data were collected at trot from three strides of eight horses overground. The position of the COM was determined from the weighted summation of the segmental COMs from previously determined inertial data of Warmblood horses. The COM of the standing model was manipulated cranially and caudally to test the effects of pitching moments during trotting. Pitching moments were calculated for each manipulation of the model and their relationship determined using reduced major axis regression.ResultsOver the stride, the moments must sum to zero to prevent accumulation of rotational motion. This was found when the weight on the forelimbs in standing was 58.7% ± 3% (mean ± 95% C.I.). With this weight distribution moments were typically nose‐up changing to nose‐down at around 35% of stance, and then reversing again to nose‐up in late stance.ConclusionsDivergence of the COM from the COP creating a vertical force moment arm prior to midstance may aid in accelerating the COM about the hind foot, thereby passively assisting hindlimb propulsion. Lower forelimb weighting resulted in mean nose‐up moments. Higher forelimb weighting resulted in mean nose‐down moments. Both would cause an accumulation of pitching motion.Ethical Animal ResearchThe study was performed with approval from the institutional animal care and use committee under protocol number 02/08‐020‐00. Sources of funding: This study was funded by Michigan State University and the University of Central Lancashire. Competing interests: none.
Optimal Gait Parameters for Quantifying the Effect of Diagnostic Analgesia in Horses
Authors: Pfau T , Spicer‐Jenkins C , Smith R , Bolt D , Fiske Jackson A , Witte T 
Published: June 2014

IntroductionEvaluating responses of horses to diagnostic analgesia is subject to bias. Pelvic movement symmetry can be measured accurately with inertial sensors, but it is unclear which of the many symmetry measures best reflect changes. It was hypothesised that objective parameters mimicking commonly observed visual parameters used by veterinarians (difference between upward/downward sacral movement and between amplitudes of left and right tuber coxa motion) would show the largest, most consistent responses.Methods13 horses underwent visual lameness scoring and independent gait assessment with inertial sensors during clinical lameness investigations. Multiple movement symmetry parameters were calculated and changes before/after diagnostic analgesia regressed against change in lameness grade. Confidence intervals of slopes of regression lines were assessed to identify significant changes.ResultsAll parameters showed variation between horses and across lameness grades. Three measures documented a consistent increase in symmetry for each grade of change in lameness score: difference between sacral displacement minima, and upward movement difference and range of motion difference between the tubera coxae. A change in symmetry of 9–13% for each grade of increase in lameness can be expected.ConclusionsThe three most promising pelvic parameters for consistent quantification of changes due to diagnostic analgesia in the hindlimb of lame horses were identified. Difference in upward movement between left and right tuber coxae is the most sensitive but requires simultaneously focusing on pelvic and limb movements and may therefore be more difficult to assess visually. Showing a similar response to diagnostic analgesia, the difference in movement amplitude between left and right tuber coxae may be more easily perceived since it does not require simultaneous focus on limb movement.Ethical Animal ResearchThe study was approved by the local ethics committee. Explicit owner informed consent for participation in this study is not stated. Sources of funding: None declared. Competing interests: none.