To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Species distribution models (SDMs) are statistical tools used to develop continuous predictions of species occurrence. ‘Integrated SDMs’ (ISDMs) are an elaboration of this approach with potential advantages that allow for the dual use of opportunistically collected presence-only data and site-occupancy data from planned surveys. These models also account for survey bias and imperfect detection through the use of a hierarchical modelling framework that separately estimates the species–environment response and detection process. This is particularly helpful for conservation applications and predictions for rare species, where data are often limited and prediction errors may have significant management consequences. Despite this potential importance, ISDMs remain largely untested under a variety of scenarios. We performed an exploration of key modelling decisions and assumptions on an ISDM using the endangered Baird’s tapir (Tapirus bairdii) as a test species. We found that site area had the strongest effect on the magnitude of population estimates and underlying intensity surface and was driven by estimates of model intercepts. Selecting a site area that accounted for the individual movements of the species within an average home range led to population estimates that coincided with expert estimates. ISDMs that do not account for the individual movements of species will likely lead to less accurate estimates of species intensity (number of individuals per unit area) and thus overall population estimates. This bias could be severe and highly detrimental to conservation actions if uninformed ISDMs are used to estimate global populations of threatened and data-deficient species, particularly those that lack natural history and movement information. However, the ISDM was consistently the most accurate model compared to other approaches, which demonstrates the importance of this new modelling framework and the ability to combine opportunistic data with systematic survey data. Thus, we recommend researchers use ISDMs with conservative movement information when estimating population sizes of rare and data-deficient species. ISDMs could be improved by using a similar parameterization to spatial capture–recapture models that explicitly incorporate animal movement as a model parameter, which would further remove the need for spatial subsampling prior to implementation.
The partition of the total genetic variance into its additive and non-additive components can differ from trait to trait, and between purebred and crossbred populations. A quantification of these genetic variance components will determine the extent to which it would be of interest to account for dominance in genomic evaluations or to establish mate allocation strategies along different populations and traits. This study aims at assessing the contribution of the additive and dominance genomic variances to the phenotype expression of several purebred Piétrain and crossbred (Piétrain × Large White) pig performances. A total of 636 purebred and 720 crossbred male piglets were phenotyped for 22 traits that can be classified into six groups of traits: growth rate and feed efficiency, carcass composition, meat quality, behaviour, boar taint and puberty. Additive and dominance variances estimated in univariate genotypic models, including additive and dominance genotypic effects, and a genomic inbreeding covariate allowed to retrieve the additive and dominance single nucleotide polymorphism variances for purebred and crossbred performances. These estimated variances were used, together with the allelic frequencies of the parental populations, to obtain additive and dominance variances in terms of genetic breeding values and dominance deviations. Estimates of the Piétrain and Large White allelic contributions to the crossbred variance were of about the same magnitude in all the traits. Estimates of additive genetic variances were similar regardless of the inclusion of dominance. Some traits showed relevant amount of dominance genetic variance with respect to phenotypic variance in both populations (i.e. growth rate 8%, feed conversion ratio 9% to 12%, backfat thickness 14% to 12%, purebreds-crossbreds). Other traits showed higher amount in crossbreds (i.e. ham cut 8% to 13%, loin 7% to 16%, pH semimembranosus 13% to 18%, pH longissimus dorsi 9% to 14%, androstenone 5% to 13% and estradiol 6% to 11%, purebreds-crossbreds). It was not encountered a clear common pattern of dominance expression between groups of analysed traits and between populations. These estimates give initial hints regarding which traits could benefit from accounting for dominance for example to improve genomic estimated breeding value accuracy in genetic evaluations or to boost the total genetic value of progeny by means of assortative mating.
Objectives: Research has shown that analyzing intrusion errors generated on verbal learning and memory measures is helpful for distinguishing between the memory disorders associated with Alzheimer’s disease (AD) and other neurological disorders, including Huntington’s disease (HD). Moreover, preliminary evidence suggests that certain clinical populations may be prone to exhibit different types of intrusion errors. Methods: We examined the prevalence of two new California Verbal Learning Test-3 (CVLT-3) intrusion subtypes – across-trial novel intrusions and across/within trial repeated intrusions – in individuals with AD or HD. We hypothesized that the encoding/storage impairment associated with medial-temporal involvement in AD would result in a greater number of novel intrusions on the delayed recall trials of the CVLT-3, whereas the executive dysfunction associated with subcortical-frontal involvement in HD would result in a greater number of repeated intrusions across trials. Results: The AD group generated significantly more across-trial novel intrusions than across/within trial repeated intrusions on the delayed cued-recall trials, whereas the HD group showed the opposite pattern on the delayed free-recall trials. Conclusions: These new intrusion subtypes, combined with traditional memory analyses (e.g., recall versus recognition performance), promise to enhance our ability to distinguish between the memory disorders associated with primarily medial-temporal versus subcortical-frontal involvement.
Surgery for CHD has been slow to develop in parts of the former Soviet Union. The impact of an 8-year surgical assistance programme between an emerging centre and a multi-disciplinary international team that comprised healthcare professionals from developed cardiac programmes is analysed and presented.
Material and methods
The international paediatric assistance programme included five main components – intermittent clinical visits to the site annually, medical education, biomedical engineering support, nurse empowerment, and team-based practice development. Data were analysed from visiting teams and local databases before and since commencement of assistance in 2007 (era A: 2000–2007; era B: 2008–2015). The following variables were compared between periods: annual case volume, operative mortality, case complexity based on Risk Adjustment for Congenital Heart Surgery (RACHS-1), and RACHS-adjusted standardised mortality ratio.
A total of 154 RACHS-classifiable operations were performed during era A, with a mean annual case volume by local surgeons of 19.3 at 95% confidence interval 14.3–24.2, with an operative mortality of 4.6% and a standardised mortality ratio of 2.1. In era B, surgical volume increased to a mean of 103.1 annual cases (95% confidence interval 69.1–137.2, p<0.0001). There was a non-significant (p=0.84) increase in operative mortality (5.7%), but a decrease in standardised mortality ratio (1.2) owing to an increase in case complexity. In era B, the proportion of local surgeon-led surgeries during visits from the international team increased from 0% (0/27) in 2008 to 98% (58/59) in the final year of analysis.
The model of assistance described in this report led to improved adjusted mortality, increased case volume, complexity, and independent operating skills.
Major depressive disorder (MDD) is a leading cause of disease burden worldwide, with lifetime prevalence in the United States of 17%. Here we present the results of the first prospective, large-scale, patient- and rater-blind, randomized controlled trial evaluating the clinical importance of achieving congruence between combinatorial pharmacogenomic (PGx) testing and medication selection for MDD.
1,167 outpatients diagnosed with MDD and an inadequate response to ≥1 psychotropic medications were enrolled and randomized 1:1 to a Treatment as Usual (TAU) arm or PGx-guided care arm. Combinatorial PGx testing categorized medications in three groups based on the level of gene-drug interactions: use as directed, use with caution, or use with increased caution and more frequent monitoring. Patient assessments were performed at weeks 0 (baseline), 4, 8, 12 and 24. Patients, site raters, and central raters were blinded in both arms until after week 8. In the guided-care arm, physicians had access to the combinatorial PGx test result to guide medication selection. Primary outcomes utilized the Hamilton Depression Rating Scale (HAM-D17) and included symptom improvement (percent change in HAM-D17 from baseline), response (50% decrease in HAM-D17 from baseline), and remission (HAM-D17<7) at the fully blinded week 8 time point. The durability of patient outcomes was assessed at week 24. Medications were considered congruent with PGx test results if they were in the ‘use as directed’ or ‘use with caution’ report categories while medications in the ‘use with increased caution and more frequent monitoring’ were considered incongruent. Patients who started on incongruent medications were analyzed separately according to whether they changed to congruent medications by week8.
At week 8, symptom improvement for individuals in the guided-care arm was not significantly different than TAU (27.2% versus 24.4%, p=0.11). However, individuals in the guided-care arm were more likely than those in TAU to achieve remission (15% versus 10%; p<0.01) and response (26% versus 20%; p=0.01). Remission rates, response rates, and symptom reductions continued to improve in the guided-treatment arm until the 24week time point. Congruent prescribing increased to 91% in the guided-care arm by week 8. Among patients who were taking one or more incongruent medication at baseline, those who changed to congruent medications by week 8 demonstrated significantly greater symptom improvement (p<0.01), response (p=0.04), and remission rates (p<0.01) compared to those who persisted on incongruent medications.
Combinatorial PGx testing improves short- and long-term response and remission rates for MDD compared to standard of care. In addition, prescribing congruency with PGx-guided medication recommendations is important for achieving symptom improvement, response, and remission for MDD patients.
Funding Acknowledgements: This study was supported by Assurex Health, Inc.
Objectives: The third edition of the California Verbal Learning Test (CVLT-3) includes a new index termed List A versus Novel/Unrelated recognition discriminability (RD) on the Yes/No Recognition trial. Whereas the Total RD index incorporates false positive (FP) errors associated with all distractors (including List B and semantically related items), the new List A versus Novel/Unrelated RD index incorporates only FP errors associated with novel, semantically unrelated distractors. Thus, in minimizing levels of source and semantic interference, the List A versus Novel/Unrelated RD index may yield purer assessments of yes/no recognition memory independent of vulnerability to source memory difficulties or semantic confusion, both of which are often seen in individuals with primarily frontal-system dysfunction (e.g., early Huntington’s disease [HD]). Methods: We compared the performance of individuals with Alzheimer’s disease (AD) and HD in mild and moderate stages of dementia on CVLT-3 indices of Total RD and List A versus Novel/Unrelated RD. Results: Although AD and HD subgroups exhibited deficits on both RD indices relative to healthy comparison groups, those with HD generally outperformed those with AD, and group differences were more robust on List A versus Novel/Unrelated RD than on Total RD. Conclusions: Our findings highlight the clinical utility of the new CVLT-3 List A versus Novel/Unrelated RD index, which (a) maximally assesses yes/no recognition memory independent of source and semantic interference; and (b) provides a greater differentiation between individuals whose memory disorder is primarily at the encoding/storage level (e.g., as in AD) versus at the retrieval level (e.g., as in early HD). (JINS, 2018, 24, 833–841)
Moving gilts from a strawed pen to a crate during farrowing profoundly inhibits oxytocin, probably as a result of a stress-induced opioid-inhibition of hypothalamic oxytocin release (Lawrence et al., 1992). Other work suggests that confinement of gilts in crates for 5 days prior to farrowing protects the gilt against stressinduced inhibition of oxytocin. As producers introduce gilts and sows into farrowing crates at variable times prior to farrowing it is important to identify the minimal period of exposure to crates required to confer adaptation. This work tested whether only a short period of adaptation (1 day) to farrowing crates prior to expected farrowing date (EFD) would be sufficient to prevent stress-induced inhibition of oxytocin.
JC virus is the etiological agent of progressive multifocal leukoencephalopathy, a white matter demyelinating disease that mostly affects immunocompromised patients. JC virus can also infect neurons and meningeal cells and cause encephalitis, meningitis and granule cell neuronopathy. We report a patient with JC virus granule cell neuronopathy, without concomitant progressive multifocal leukoencephalopathy, presenting as inaugural acquired immune deficiency syndrome-related illness. This patient’s human immunodeficiency virus infection remained undiagnosed for several months after neurological symptoms onset. We review JC virus pathophysiology, clinical manifestations, treatment and prognosis, and emphasize the importance of considering human immunodeficiency virus infection and related opportunistic infections in the differential diagnosis of new-onset isolated cerebellar disease.
The importance of parasites as a selective force in host evolution is a topic of current interest. However, short-term ecological studies of host–parasite systems, on which such studies are usually based, provide only snap-shots of what may be dynamic systems. We report here on four surveys, carried out over a period of 12 years, of helminths of spiny mice (Acomys dimidiatus), the numerically dominant rodents inhabiting dry montane wadis in the Sinai Peninsula. With host age (age-dependent effects on prevalence and abundance were prominent) and sex (female bias in abundance in helminth diversity and in several taxa including Cestoda) taken into consideration, we focus on the relative importance of temporal and spatial effects on helminth infracommunities. We show that site of capture is the major determinant of prevalence and abundance of species (and higher taxa) contributing to helminth community structure, the only exceptions being Streptopharaus spp. and Dentostomella kuntzi. We provide evidence that most (notably the Spiruroidea, Protospirura muricola, Mastophorus muris and Gongylonema aegypti, but with exceptions among the Oxyuroidae, e.g. Syphacia minuta), show elements of temporal-site stability, with a rank order of measures among sites remaining similar over successive surveys. Hence, there are some elements of predictability in these systems.
Good education requires student experiences that deliver lessons about practice as well as theory and that encourage students to work for the public good—especially in the operation of democratic institutions (Dewey 1923; Dewy 1938). We report on an evaluation of the pedagogical value of a research project involving 23 colleges and universities across the country. Faculty trained and supervised students who observed polling places in the 2016 General Election. Our findings indicate that this was a valuable learning experience in both the short and long terms. Students found their experiences to be valuable and reported learning generally and specifically related to course material. Postelection, they also felt more knowledgeable about election science topics, voting behavior, and research methods. Students reported interest in participating in similar research in the future, would recommend other students to do so, and expressed interest in more learning and research about the topics central to their experience. Our results suggest that participants appreciated the importance of elections and their study. Collectively, the participating students are engaged and efficacious—essential qualities of citizens in a democracy.
The impact of a deep-water plunging breaker on a finite height two-dimensional structure with a vertical front face is studied experimentally. The structure is located at a fixed horizontal position relative to a wave maker and the structure’s bottom surface is located at a range of vertical positions close to the undisturbed water surface. Measurements of the water surface profile history and the pressure distribution on the front surface of the structure are performed. As the vertical position,
axis is positive up and
is the mean water level), of the structure’s bottom surface is varied from one experimental run to another, the water surface evolution during impact can be categorized into three classes of behaviour. In class I, with
in a range of values near
is the nominal wavelength of the breaker, the behaviour of the water surface is similar to the flip-through phenomena first described in studies with shallow water and a structure mounted on the sea bed. In the present work, it is found that the water surface between the front face of the structure and the wave crest is well fitted by arcs of circles with a decreasing radius and downward moving centre as the impact proceeds. A spatially and temporally localized high-pressure region was found on the impact surface of the structure and existing theory is used to explore the physics of this phenomenon. In class II, with
in a range of values near the mean water level, the bottom of the structure exits and re-enters the water phase at least once during the impact process. These air–water transitions generate large-amplitude ripple packets that propagate to the wave crest and modify its behaviour significantly. At
, all sensors submerged during the impact record a nearly in-phase high-frequency pressure oscillation indicating possible air entrainment. In class III, with
in a range of values near
, the bottom of the structure remains in air before the main crest hits the bottom corner of the structure. The subsequent free surface behaviour is strongly influenced by the instantaneous momentum of the local flow just before impact and the highest wall pressures of all experimental conditions are found.
Self-criticism is a ubiquitous feature of psychopathology and can be
combatted by increasing levels of self-compassion. However, some patients
are resistant to self-compassion.
To investigate whether the effects of self-identification with virtual
bodies within immersive virtual reality could be exploited to increase
self-compassion in patients with depression.
We developed an 8-minute scenario in which 15 patients practised
delivering compassion in one virtual body and then experienced receiving
it from themselves in another virtual body.
In an open trial, three repetitions of this scenario led to significant
reductions in depression severity and self-criticism, as well as to a
significant increase in self-compassion, from baseline to 4-week
follow-up. Four patients showed clinically significant improvement.
The results indicate that interventions using immersive virtual reality
may have considerable clinical potential and that further development of
these methods preparatory to a controlled trial is now warranted.
Atrial fibrillation (AF) is the most common arrhythmia presentation to the emergency department (ED) and frequently results in admission to the hospital. Although rarely life-threatening and not usually an emergent condition, AF places a large burden on our health-care system. The objective of this study was to describe the practices of ED physicians in the management of AF in a large urban Canadian city.
From January 1, 2010 to December 31, 2010, patients with a primary diagnosis of AF were identified across 10 EDs in Toronto, Canada (N=2,609). Fifty patients were selected at random from each hospital for a detailed chart review (n=500).
Two hundred thirty-two patients (46%) received rate control, and 129 (26%) received rhythm control with the remainder (28%) receiving neither therapy. Sixty-seven percent of patients were discharged home. Most patients (79%) were symptomatic on arrival; however, only a minority of these (31%) received rhythm control. Factors that were associated with rhythm control included younger age, duration of palpitations ≤ 48 hours, a lower CHADS2 score, and the absence of left ventricular dysfunction.
Our data suggest a wide range of practice amongst ED physicians treating patients presenting to the ED with a primary diagnosis of AF. A randomized trial is needed to better understand the optimal management strategy in this patient population and setting.
The absence of a dedicated transport for disaccharides in the intestine implicates that the metabolic use of dietary lactose relies on its prior hydrolysis at the intestinal brush border. Consequently, lactose in blood or urine has mostly been associated with specific cases in which the gastrointestinal barrier is damaged. On the other hand, lactose appears in the blood of lactating women and has been detected in the blood and urine of healthy men, indicating that the presence of lactose in the circulation of healthy subjects is not incompatible with normal physiology. In this cross-over study we have characterised the postprandial kinetics of lactose, and its major constituent, galactose, in the serum of fourteen healthy men who consumed a unique dose of 800 g milk or yogurt. Genetic testing for lactase persistence and microbiota profiling of the subjects were also performed. Data revealed that lactose does appear in serum after dairy intake, although with delayed kinetics compared with galactose. Median serum concentrations of approximately 0·02 mmol/l lactose and approximately 0·2 mmol/l galactose were observed after the ingestion of milk and yogurt respectively. The serum concentrations of lactose were inversely correlated with the concentrations of galactose, and the variability observed between the subjects’ responses could not be explained by the presence of the lactase persistence allele. Finally, lactose levels have been associated with the abundance of the Veillonella genus in faecal microbiota. The measurement of systemic lactose following dietary intake could provide information about lactose metabolism and nutrient transport processes under normal or pathological conditions.
Background: Understanding successful and unsuccessful behavioural treatment for pain is essential. Aims: We carried out a retrospective survey of 130 people who had undergone pain rehabilitation based on acceptance and commitment therapy, aiming to identify factors associated with non-response. Method: The sample was selected using the reliable change index to define ‘responders’ and ‘non-responders’ to key outcome measures. We surveyed a range of treatment-related, systemic, practical and personal factors that may have affected their treatment, and then compared ‘non-responders’ with ‘responders’, controlling for factors that might not be causal or specific to non-response. Results: Logistic regression analysis showed two themes that distinguished the groups, ‘people outside programme’ and ‘emotional state’. Conclusions: These data have clinical implications, as such factors can be addressed directly or incorporated into an assessment of treatment ‘readiness’. This study introduced a novel methodology for the investigation of pain treatment response, which allowed a broad study of clinically relevant variables, but with greater rigour than conventional self-reports of ‘helpful factors’ in treatment.
For most of the Twentieth Century the angiosperm archetypal flower has been viewed as relatively large, multiparted, with spirally arranged fleshy appendages, and as being probably beetle pollinated as in some extant Magnoliales. However, the preponderance of fossil evidence indicates that flowers with such characters do not appear until the mid-Cretaceous, well after smaller simpler fossil flowers such as platanoids and chloranthoids. Winteraceous and Chloranthaceous pollen appears more or less simultaneously in the Lower Cretaceous, but rapidly mounting evidence for mosaicism in Cretaceous taxa makes it unwise to extrapolate floral structure on the basis of dispersed pollen. Mid-Late Cretaceous fossils illustrate an increasing proportion of simple flowered Rosidae in the angiosperm flora. We report new fossil evidence of charcoalified flowers and fruits representing at least 20–30 diverse angiosperm taxa from the Cenomanian and Turonian deposits of the Atlantic Coastal Plain. These fossil flowers include representatives with hypanthia and floral cups, sympetaly, syncarpy, inferior ovaries, campylotropous ovules, nectaries of various forms, specialized anther dehiscence, epipetalous stamens, and connate filament tubes. Major taxonomic groups (as defined by Cronquist) represented by these fossils include Dilleniidae, Magnoliidae, Rosidae, monocots, and possibly Caryophyllidae. Thus, the early Late Cretaceous angiosperm flora had greater floral diversity than has previously been documented. This array of floral structures includes features that are now associated with bees and other specialized insect pollinators, thus providing a new perspective on the evolution of insect pollination.
Probiotic yogurt and milk supplemented with probiotics have been investigated for their role in ‘low-grade’ inflammation but evidence for their efficacy is inconclusive. This study explores the impact of probiotic yogurt on metabolic and inflammatory biomarkers, with a parallel study of gut microbiota dynamics. The randomised cross-over study was conducted in fourteen healthy, young men to test probiotic yogurt compared with milk acidified with 2 % d-(+)-glucono-δ-lactone during a 2-week intervention (400 g/d). Fasting assessments, a high-fat meal test (HFM) and microbiota analyses were used to assess the intervention effects. Baseline assessments for the HFM were carried out after a run-in during which normal milk was provided. No significant differences in the inflammatory response to the HFM were observed after probiotic yogurt compared with acidified milk intake; however, both products were associated with significant reductions in the inflammatory response to the HFM compared with the baseline tests (assessed by IL6, TNFα and chemokine ligand 5) (P<0·001). These observations were accompanied by significant changes in microbiota taxa, including decreased abundance of Bilophila wadsworthia after acidified milk (log 2-fold-change (FC)=–1·5, Padj=0·05) and probiotic yogurt intake (FC=–1·3, Padj=0·03), increased abundance of Bifidobacterium species after acidified milk intake (FC=1·4, Padj=0·04) and detection of Lactobacillus delbrueckii spp. bulgaricus (FC=7·0, Padj<0·01) and Streptococcus salivarius spp. thermophilus (FC=6·0, Padj<0·01) after probiotic yogurt intake. Probiotic yogurt and acidified milk similarly reduce postprandial inflammation that is associated with a HFM while inducing distinct changes in the gut microbiota of healthy men. These observations could be relevant for dietary treatments that target ‘low-grade’ inflammation.
Introduction: Decreasing readmission rates and return emergency department (ED) visits represent a major challenge for health organizations. Seniors are especially vulnerable to discharge adverse events which can result in unplanned readmissions and loss of physical, functional and/or cognitive capacity. The ACE Collaborative is a national quality improvement initiative that aims to improve care of elderly patients. We aimed to adapt Mount Sinai’s Care Transitions program to our local context in order to decrease avoidable readmissions and ED visits among seniors. Methods: We performed a prospective pre/post implementation cohort study. We recruited frail elderly hospitalized patients (≥50 years old) discharged to home and at risk of readmission (modified LACE index score≥7/12). We excluded patients being discharged to long-term nursing homes or institutions. Our intervention is based on selected strategic ACE Care Transitions best practices: transition coach, telehealth personal response services and a structured discharge checklist. The intervention is offered to selected patients before hospital discharge. Our primary outcome is a 30-day post-discharge composite of hospital readmission and return ED visit rate. Our secondary outcomes are functional autonomy, satisfaction with care transition, quality of life, caregiver strain and healthcare resource use at recruitment and at 30-days follow-up. Hospital-level administrative data is also collected to measure global effect of practice changes. Results: The project is currently ongoing and preliminary results are available for the pre-implementation cohort only. Patients in this cohort (n=33) were mainly men (61%), aged 75±10 years and presented an OARS score (Activities of Daily Living instrument that ranges from 0-28) of 5.6±4.9. At 30 days post-discharge, the patients in our cohort had a 42.4% readmission rate (14 hospitalisations) and a 54.5% return ED visit rate (18 visits). For the same time period, readmission and return ED rates for all patients in the same corresponding age-group at the hospital level were 14.4% and 21.9%, respectively. Further results for our post-intervention cohort will be presented at CAEP 2017. Conclusion: Our cohort of elderly patients have high readmission and return ED visit rates. Our ongoing quality improvement project aims to decrease these readmissions and ED visits.
The primary goal was to investigate the effects of l-carnitine on fuel efficiency, as an antioxidant, and for muscle recovery in Labrador retrievers. Dogs were split into two groups, with one group being supplemented with 250 mg/d of Carniking™ l-carnitine powder. Two experiments (Expt 1 and Expt 2) were performed over a 2-year period which included running programmes, activity monitoring, body composition scans and evaluation of recovery using biomarkers. Each experiment differed slightly in dog number and design: fifty-six v. forty dogs; one endurance and two sprint runs per week v. two endurance runs; and differing blood collection time points. All dogs were fed a low-carnitine diet in which a fixed amount was offered based on maintaining the minimum starting weight. Results from Expt 1 found that the carnitine dogs produced approximately 4000 more activity points per km compared with the control group during sprint (P = 0·052) and endurance runs (P = 0·0001). Male carnitine dogs produced half the creatine phosphokinase (CPK) following exercise compared with male control dogs (P = 0·05). Carnitine dogs had lower myoglobin at 6·69 ng/ml following intensive exercise compared with controls at 24·02 ng/ml (P = 0·0295). Total antioxidant capacity (TAC) and thiobarbituric acid reactive substance (TBARS) results were not considered significant. In Expt 2, body composition scans indicated that the carnitine group gained more total tissue mass while controls lost tissue mass (P = 0·0006) and also gained lean mass while the control group lost lean mass (P < 0·0001). Carnitine dogs had lower CPK secretion at 23·06 v. control at 28·37 mU/ml 24 h after post-run (P = 0·003). Myoglobin levels were lower in carnitine v. control dogs both 1 h post-run (P = 0·0157; 23·83 v. 37·91 ng/ml) and 24 h post-run (P = 0·0189; 6·25 v.13·5 ng/ml). TAC indicated more antioxidant activity in carnitine dogs at 0·16 mmv. control at 0·13 mm (P = 0·0496). TBARS were also significantly lower in carnitine dogs both pre-run (P = 0·0013; 15·36 v. 23·42 µm) and 1 h post-run (P = 0·056; 16·45 v. 20·65 µm). Supplementing l-carnitine in the form of Carniking™ had positive benefits in Labrador retrievers for activity intensity, body composition, muscle recovery and oxidative capacity.