Ligamentous healing potential of the acromioclavicular ligament following acute anatomical reconstruction.

BACKGROUND: Horizontal instability following acute acromioclavicular joint (ACJ) reconstruction still occurs with a high prevalence. Although the human acromioclavicular ligament complex (ACLC) represents the major horizontal ACJ stabilizer, experimental studies on healing characteristics are lacking. Therefore, the purpose of this histological study was to investigate the healing potential of the ACLC following acute anatomical reconstruction METHODS: In this prospective clinical-experimental study, 28 ACLC biopsies were performed in patients with complete ACJ dislocations (Rockwood type 4 or 5) during acute hook plate stabilization (IG: implantation group; n = 14) and hook plate removal (EG: explantation group; n = 14). Histological analyses included Giemsa staining, polarized light microscopy and immunostaining against CD68, αSMA and collagen type I and type III. Histomorphological evaluation entailed cell counts, collagen expression score, ligament tissue maturity index (LTMI) and descriptive analysis of specific ligamentous structures. Statistics consisted of nonparametric Mann-Whitney U tests and a level of significance of P < .05. RESULTS: Total cell counts (cells/mm2 1491 ± 296 vs. 635 ± 430; P < 0.001) and collagen III expression (3.22 ± 0.22 vs. 1.78 ± 0.41; P < 0.001) were higher in EG compared to IG. Inversely αSMA + (11 ± 9 vs. 179 ± 186; P < 0.001) and CD68 + cell counts (56 ± 20 vs. 100 ± 57; P 0.009) were significantly lower in the EG. The EG revealed a comparable reorientation of ligamentous structures. Consistently, ACLC samples of the EG (21.6 ± 2.4) displayed a high total but differently composed LTMI score (IG: 24.5 ± 1.2; P < 0.001). CONCLUSIONS: This experimental study proved the ligamentous healing potential of the human ACLC following acute anatomical reconstruction. Histomorphologically, the ACLC reliably showed a ligamentous state of healing at a mean of about 12 weeks after surgery. However, processes of ligamentous remodeling were still evident. These experimental findings support recent clinical data showing superior horizontal ACJ stability with additional AC stabilization in the context of acute ACJ reconstruction. Though, prospective clinical and biomechanical studies are warranted to evaluate influencing factors on ACLC healing and potential impacts of acute ACLC repair on clinical outcome. STUDY TYPE: Controlled Laboratory Study.

Assessing selection signatures within and between selected lines of dual-purpose black and white and German Holstein cattle.

The aim of this study was to detect selection signatures considering cows from the German Holstein (GH) and the local dual-purpose black and white (DSN) population, as well as from generated sub-populations. The 4654 GH and 261 DSN cows were genotyped with the BovineSNP50 Genotyping BeadChip. The geographical herd location was used as an environmental descriptor to create the East-DSN and West-DSN sub-populations. In addition, two further sub-populations of GH cows were generated, using the extreme values for solutions of residual effects of cows for the claw disorder dermatitis digitalis. These groups represented the most susceptible and most resistant cows. We used cross-population extended haplotype homozygosity methodology (XP-EHH) to identify the most recent selection signatures. Furthermore, we calculated Wright's fixation index (FST ). Chromosomal segments for the top 0.1 percentile of negative or positive XP-EHH scores were studied in detail. For gene annotations, we used the Ensembl database and we considered a window of 250 kbp downstream and upstream of each core SNP corresponding to peaks of XP-EHH. In addition, functional interactions among potential candidate genes were inferred via gene network analyses. The most outstanding XP-EHH score was on chromosome 12 (at 77.34 Mb) for DSN and on chromosome 20 (at 36.29-38.42 Mb) for GH. Selection signature locations harbored QTL for several economically important milk and meat quality traits, reflecting the different breeding goals for GH and DSN. The average FST value between GH and DSN was quite low (0.068), indicating shared founders. For group stratifications according to cow health, several identified potential candidate genes influence disease resistance, especially to dermatitis digitalis.

A novel mutation in the TG gene (G2322S) causing congenital hypothyroidism in a Sudanese family: a case report.

BACKGROUND: Congenital hypothyroidism (CH) has an incidence of approximately 1:3000, but only 15% have mutations in the thyroid hormone synthesis pathways. Genetic analysis allows for the precise diagnosis. CASE PRESENTATION: A 3-week old girl presented with a large goiter, serum TSH > 100 mIU/L (reference range: 0.7-5.9 mIU/L); free T4 < 3.2 pmol/L (reference range: 8.7-16 pmol/L); thyroglobulin (TG) 101 µg/L. Thyroid Tc-99 m scan showed increased radiotracer uptake. One brother had CH and both affected siblings have been clinically and biochemically euthyroid on levothyroxine replacement. Another sibling had normal thyroid function. Both Sudanese parents reported non-consanguinity. Peripheral blood DNA from the proposita was subjected to whole exome sequencing (WES). WES identified a novel homozygous missense mutation of the TG gene: c.7021G > A, p.Gly2322Ser, which was subsequently confirmed by Sanger sequencing and present in one allele of both parents. DNA samples from 354 alleles in four Sudanese ethnic groups (Nilotes, Darfurians, Nuba, and Halfawien) failed to demonstrate the presence of the mutant allele. Haplotyping showed a 1.71 centiMorgans stretch of homozygosity in the TG locus suggesting that this mutation occurred identical by descent and the possibility of common ancestry of the parents. The mutation is located in the cholinesterase-like (ChEL) domain of TG. CONCLUSIONS: A novel rare missense mutation in the TG gene was identified. The ChEL domain is critical for protein folding and patients with CH due to misfolded TG may present without low serum TG despite the TG gene mutations.

[Primary fracture protheses and reverse shoulder arthroplasty in complex humeral head fractures : An alternative to joint-preserving osteosynthesis?] / Primäre Frakturprothese und inverse Schulterprothese bei komplexer Humeruskopffraktur : Eine Alternative zur gelenkerhaltenden Osteosynthese?

BACKGROUND: The surgical management of complex humeral head fractures has adapted dynamically over the course of the last decade. The primary use of reverse shoulder arthroplasty in elderly patients has gained in relevance due to promising short and middle-term results. Long-term results, however, are still pending. The appliance of anatomical hemiarthroplasty, on the other hand, has lost in significance in favour of osteosynthesis and reverse shoulder arthroplasty. INDICATIONS: This review article follows the question as to under which circumstances primary fracture arthroplasty reflects an alternative or even a preference to joint-preserving osteosynthesis in the treatment of complex proximal humeral fractures. It also specifies spectrums of indications for anatomical hemiarthroplasty and reverse shoulder arthroplasty.

[Influencing factors and complications in open treatment of acute anterior glenoid rim fractures]. / Einflussfaktoren und Komplikationen bei offener Versorgung akuter anteriorer Glenoidrandfrakturen.

BACKGROUND: The aim of this comparative study was to evaluate the clinical radiological outcome after open treatment of acute anterior glenoid rim fractures and to analyze the influencing factors and complications. PATIENTS AND METHODS: The study included 26 patients with an average age of 51.6 years (range 27-71 years) at surgery. The mean period of follow-up was 5.1 years (range 2.0-11.1 years). The average extent of glenoid fracture involvement was 25.5 % (range 18-35%) and three fixation techniques were applied: 1) bioresorbable pins (n = 16), 2) small fragment screws (n = 5) and 3) bioresorbable suture anchors (n = 5). RESULTS: The mean score values were 80.3 points for the absolute Constant score, 87.6 points for the normalized Constant score, 88.7 points for the Rowe score, 17.4 points for the Oxford shoulder score, 10.3 points for the simple shoulder test, 13.0 points for the shoulder pain and disability index and 81.5 % for the subjective shoulder value. The fixation technique did not show a significant influence; however, multi-fragment fractures were associated with a significantly inferior absolute (73 vs. 87 points, p = 0.022) and normalized Constant scores (81 vs. 94 points, p = 0.019). Subscapularis insufficiency with internal rotation deficit was found in 10 (39 %) patients and posttraumatic osteoarthritis occurred in 6 (23 %) patients. CONCLUSION: Open fixation yielded good or excellent shoulder function in 20 out of the 26 (77 %) patients and the clinical outcome primarily depended on the underlying type of fracture. Significantly inferior outcomes should be expected in patients with multi-fragment fractures. The main complications were subscapularis insufficiency and posttraumatic osteoarthritis.

Association of a variable number tandem repeat in the NLRP3 gene in women with susceptibility to RVVC.

Vaginal infections with Candida spp. frequently occur in women of childbearing age. A small proportion of these women experience recurrent vulvovaginal candidosis (RVVC), which is characterized by at least three episodes of infection in one year. In addition to known risk factors such as antibiotics, diabetes, or pregnancy, host genetic variation and inflammatory pathways such as the IL-1/Th17 axis have been reported to play a substantial role in the pathogenesis of RVVC. In this study, we assessed a variable number tandem repeat (VNTR) polymorphism in the NLRP3 gene that encodes a component of the inflammasome, processing the proinflammatory cytokines IL-1ß and IL-18. A total of 270 RVVC patients and 583 healthy controls were analyzed, and increased diseases susceptibility was associated with the presence of the 12/9 genotype. Furthermore, functional studies demonstrate that IL-1ß production at the vaginal surface is higher in RVVC patients bearing the 12/9 genotype compared to controls, whereas IL-1Ra levels were decreased and IL-18 levels remained unchanged. These findings suggest that IL-1ß-mediated hyperinflammation conveyed by the NLRP3 gene plays a causal role in the pathogenesis of RVVC and may identify this pathway as a potential therapeutic target in the disease.

Non-Union in Upper Limb Fractures - Clinical Evaluation and Treatment Options.

Although non-unions in the upper limb are rare different treatment options of this challenging situation are still affected with up to 20% of failure rate due to current literature. Risk factors for delayed and non-union of fractures are mainly the size of the fracture gap and bone loss of open fractures or in primary surgery followed by other relevant internal and external factors. In the upper limb non-unions of long bones are described with up to 30% after operative intervention. Especially in the upper limb range of motion is limited in non-union cases and disables adjacent joints like the shoulder, elbow and wrist hence reducing the total activity level of affected patients. Beside careful investigation of the causes leading to the non-union a comprehensive treatment plan should be defined to achieve successful results. Treatment can be non-operative in several, selected cases, but in the majority of cases revision surgery is necessary to achieve osseous healing. Our own experience showed that non-union in the upper limb are rare and account for only 1.7% of all surgical managed upper limb fractures. Non-union of upper limb fractures occur most frequently in clavicle fractures followed by humeral fractures. Atrophic non-union is the most frequent reason for osseous non-union (57%) and osseous healing after revision surgery in non-unions is completed after a mean of 6.45 months. This article will give a brief overview of the genesis, clinical evaluation, treatment options and recommendations in upper limb non-unions according to the current literature. Key words: fracture, upper-limb, non-union, osteosynthesis, cancellous bone-graft.

Pattern recognition pathways leading to a Th2 cytokine bias in allergic bronchopulmonary aspergillosis patients.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is characterised by an exaggerated Th2 response to Aspergillus fumigatus, but the immunological pathways responsible for this effect are unknown. OBJECTIVE: The aim of this study was to decipher the pattern recognition receptors (PRRs) and cytokines involved in the Aspergillus-specific Th2 response and to study Aspergillus-induced responses in healthy controls and ABPA patients. METHODS: Peripheral blood mononuclear cells (PBMCs) were stimulated with heat-killed Aspergillus conidia, various other pathogens, or PRR ligands. PRRs and cytokine pathways were blocked with PRR-blocking reagents, anti-TNF (Etanercept or Adalimumab), IL-1Ra (Anakinra) or IFNγ (IFN-gamma). ELISA and FACS were used to analyse cytokine responses. RESULTS: Aspergillus was the only pathogen that stimulated the Th2 cytokines IL-5 and IL-13, while Gram-negative bacteria, Gram-positive bacteria, Candida albicans, chitin, ß-glucan or Toll-like receptor (TLR) ligands did not. Depletion of CD4(+) cells abolished IL-13 production. Blocking complement receptor 3 (CR3) significantly reduced IL-5 and IL-13, while blocking TLR2, TLR4 or dectin-1 had no effect. ABPA patients displayed increased Aspergillus-induced IL-5 and IL-13 and decreased IFNγ production compared with healthy controls. All biological agents tested showed the capability to inhibit Th2 responses, but also decreased Aspergillus-induced IFNγ. CONCLUSIONS AND CLINICAL RELEVANCE: Aspergillus conidia are unique in triggering Th2 responses in human PBMCs, through a CR3-dependent pathway. ABPA patients display a significantly increased Aspergillus-induced Th2/Th1 ratio that can be modulated by biologicals. These data provide a rationale to explore IFNγ therapy in ABPA as a corticosteroid-sparing treatment option, by dampening Th2 responses and supplementing the IFNγ deficiency at the same time.

Postanesthetic death in a cat with myopathy.

There are few reports of naturally occurring muscular dystrophy in domestic animals. Herein, we describe a case of muscular dystrophy in a 4-year-old neutered male American domestic shorthair cat that died unexpectedly following anesthesia for an elective surgical procedure. Macroscopic muscular hypertrophy and histologic evidence of myofiber size variation, mineralization, myofiber degeneration, and necrosis were compatible with a diagnosis of muscular dystrophy. Extensive endomysial fibrosis was noted histologically in the diaphragm. A complete absence of dystrophin protein in Western blot confirmed the diagnosis of Duchenne muscular dystrophy. Immunofluorescence microscopy revealed reduced levels of dystrophin-associated proteins and an upregulation of utrophin at the sarcolemma. Anesthetic deaths can occur in dystrophin-deficient cats, and therefore muscular dystrophy and the associated cardiomyopathy should be considered in the differential diagnoses for perianesthetic death in cats.

Cervical biomechanics and neck pain of "head-spinning" breakdancers.

The cervical spine of breakdancers is at great risk due to reversed body loading during headspin manoeuvers. This study focused on the cervical biomechanics of breakdancers and a correlation with neck pain. A standardized interview and biomechanical testing of the cervical spine of 25 participants with "headspin" ability ages 16-34 years and an age-matched cohort of 25 participants without any cervical spine problems was conducted. Neck pain history, Neck Disability Index (NDI), cervical range of motion (CROM) and cervical torque were recorded. The "headspin" group reported significantly better subjective fitness, more cervical complaints, higher pain intensity, a longer history of neck pain and a worse NDI compared to the "normal" collective. The "headspin" group showed a 2-2.5 times higher rate of neck pain than the normal population, with increased cervical flexion (p<0.05) and increased cervical torque in all planes (p<0.001). The CROM showed a negative moderate to strong correlation with NDI, pain intensity and history of neck pain. Sports medicine practitioners should be aware of headspin maneuver accidents that pose the risk of fractures, dislocations and spinal cord injuries of breakdancers.

Spontaneous spinal epidural haematoma during Factor Xa inhibitor treatment (Rivaroxaban).

We report on a 61-year-old female patient who developed a spontaneous spinal epidural haematoma (SSEH) after being treated by rivaroxaban, a new agent for the prevention of venous thromboembolic events in orthopaedic surgery. Although the pathogenesis of SSEH is unclear, anticoagulant therapy is a known risk factor. The patient sustained a sudden onset of severe back pain in the thoracic spine, followed by paraplegia below T8, 2 days after proximal tibial osteotomy and rivaroxaban therapy. Magnetic resonance imaging (MRI) of the whole spine demonstrated a ventral SSEH from C2 to T8. Whilst preparing for the emergency evacuation of the SSEH, the neurological symptoms recovered spontaneously 4 h after onset without surgery. After monitored bed rest for 48 h the MRI was repeated and the SSEH was no longer present. This rare condition of spinal cord compression and unusually rapid spontaneous recovery has not previously been reported following rivaroxaban therapy.

Comparing brain tissue oxygen measurements and derived autoregulation parameters from different probes (Licox vs. Raumedic).

We investigated two commercially available probes for measurement of the partial pressure of brain tissue oxygen (PbrO2) and calculation of the index of brain tissue oxygen pressure reactivity (ORx) in 7 patients after aneurysmal subarachnoid hemorrhage (SAH). Simultaneous monitoring of PbrO2 using the Licox(®) probe and the multiparameter Raumedic probe (Neurovent PTO(®)), measuring PbrO2, intracranial pressure (ICP) and brain temperature (Neurovent PTO) was performed for a median of 9 days (range 7-17 days). Both probes provided stable monitoring throughout the desired period. Mean PbrO2 from Licox and Neurovent PTO was 16.1 ± 9.0 mmHg and 17.5 ± 11.9 mmHg respectively. Mean ORx was 0.35 ± 0.44 and 0.31 ± 0.43 respectively. There was a difference in the measurement of PbrO2 of -2.73 ± 10.1 mmHg (Licox - Raumedic). The difference in the two values for the calculated ORx was far smaller (0.03 ± 0.31; Licox - Raumedic) and the correlation coefficient higher than for both values of PbrO2 (0.76 for ORx vs. 0.56 for PbrO2). The calculation of the autoregulation parameter ORx seemed more independent of the measurement process than the measurement of PbrO2 itself and signifies the potential clinical importance of this parameter.

Fracture dislocation of the humerus with intrathoracic humeral head fragment - A case report and review of the literature.

We present a rare case of humeral fracture dislocation with intrathoracic humeral head fragment. A 74-year old female was transferred to a major trauma facility after falling on her arm while gardening. An intrathoracic humeral head fragment was diagnosed after initial imaging. In correspondence with the department of thoracic surgery, the decision was made to remove the intrathoracic fragment thoracoscopically and succeed with a reverse total shoulder arthroplasty.

Neural tracking to go: auditory attention decoding and saliency detection with mobile EEG.

Objective.Neuro-steered assistive technologies have been suggested to offer a major advancement in future devices like neuro-steered hearing aids. Auditory attention decoding (AAD) methods would in that case allow for identification of an attended speaker within complex auditory environments, exclusively from neural data. Decoding the attended speaker using neural information has so far only been done in controlled laboratory settings. Yet, it is known that ever-present factors like distraction and movement are reflected in the neural signal parameters related to attention.Approach.Thus, in the current study we applied a two-competing speaker paradigm to investigate performance of a commonly applied electroencephalography-based AAD model outside of the laboratory during leisure walking and distraction. Unique environmental sounds were added to the auditory scene and served as distractor events.Main results. The current study shows, for the first time, that the attended speaker can be accurately decoded during natural movement. At a temporal resolution of as short as 5 s and without artifact attenuation, decoding was found to be significantly above chance level. Further, as hypothesized, we found a decrease in attention to the to-be-attended and the to-be-ignored speech stream after the occurrence of a salient event. Additionally, we demonstrate that it is possible to predict neural correlates of distraction with a computational model of auditory saliency based on acoustic features.Significance.Taken together, our study shows that auditory attention tracking outside of the laboratory in ecologically valid conditions is feasible and a step towards the development of future neural-steered hearing aids.

The concurrent validity and sensitivity of change of the German version of the health of the nation outcome scales in a psychiatric inpatient setting.

BACKGROUND: The Health of the Nation Outcome Scales (HoNOS) were developed to assess the severity of a mental illness. They are used as outcome measures in different countries, and are meanwhile translated from the original English version into many languages, among others into German (HoNOS-D). We conducted a study in order to estimate the concurrent validity and sensitivity to change using clinical parameters as ICD-10 diagnoses, as well as the Clinical Global Impression Scale (CGI), and the Association for Methodology and Documentation in Psychiatry (AMDP) psychopathology scale, a frequently used psychopathological rating system, in a representative clinical sample. SAMPLING AND METHODS: Data on the three instruments (CGI, AMDP, HoNOS-D) were collected at admission and discharge of 100 psychiatric inpatients using a representative clinical sample. Experienced clinicians completed the CGI, AMDP and HoNOS-D. Descriptive and comparative data analyses were performed. We estimated the concurrent validity by calculating correlations between the HoNOS and other scales. Secondly, we examined the differences between HoNOS scores related to diagnoses and demographic parameters. Thirdly we calculated change criteria and outcome effect size for the HoNOS. RESULTS: Even in a small clinical sample (n = 100), the HoNOS-D items are highly correlated with the corresponding AMDP syndromes (p < 0.003). The HoNOS-D score is associated with the CGI score (p < 0.01). Correlations of HoNOS symptoms, behavior and impairment items with AMDP syndromes as well as differences in diagnoses were appropriate and comprehensible as regards clinical content, and change on the HoNOS total score is statistically significant (t = 6.57, d.f. = 89, p < 0.0001). CONCLUSION: This study is the first to investigate the concurrent validity of HoNOS-D concerning psychopathology using the AMDP rating system in a clinical sample of patients with mental disorders in an inpatient setting. HoNOS-D can be recommended for routinely screening outcomes in inpatient psychiatric settings. Our analysis showed that HoNOS-D covers psychopathology corresponding to the AMDP rating system. A limitation of the study is that the study sample comprised only an inpatient population; there may well be differences compared to an outpatient sample.

[Traumatic injuries of the sternoclavicular joint]. / Traumatische Verletzungen des Sternoklavikulargelenks.

Traumatic injuries of the sternoclavicular joint occur rarely and are mainly caused by an indirect trauma mechanism with high kinetic energy. Anterior dislocation is much more common than posterior dislocation, which may be associated with life-threatening injuries. The CT scan is the diagnostic tool of choice for accurate assessment of the injury and coexisting pathologies. The primary goal in anterior and posterior dislocations is an early closed reduction. In cases of redislocation after closed reduction of an anterior dislocation we recommend primary joint reconstruction on the basis of an individual therapeutic concept. Posterior dislocations often cannot be reduced by closed means. Then open reconstruction and stabilization are performed. Chronic instabilities should only be addressed surgically in cases of persistent pain and/or functional deficit. Resection of the medial clavicula represents an effective treatment option in post-traumatic sternoclavicular joint arthritis provided that the costoclavicular ligaments are intact or will be reconstructed during surgery. Physeal injuries of the medial clavicle can occur until an approximate age of 25. Closed reduction of dislocated physeal injuries is attempted. After reposition non-operative treatment in general leads to a good functional outcome. Posteriorly dislocated physeal injuries often cannot be reduced by closed means. In these cases good function can be expected after open stabilization.

[Limitations of reconstruction - prostheses]. / Grenzen der Rekonstruktion - Prothesen.

Fractures of the proximal humerus are common, particularly seen in elderly, female patients. Using open reduction and internal fixation good clinical results can be achieved in general. But even today not every problem has been solved in the treatment of proximal humeral fractures. Varus displaced fractures are particularly challenging, especially when the medial column is destroyed. Anatomical reduction of the humeral head and medial bone contact are crucial for a good surgical outcome. Otherwise a secondary varus collapse and/or an implant failure are predictable. Further challenges are the intra-articular fracture patterns, as well as fractures with an initial ischemic humeral head. The indications for prosthetic replacement are always present if an initially stable internal fixation could not be achieved. The reverse fracture prostheses represent an increasingly common treatment option; however, the indication should be reserved for the elderly over 75 years.

Humerus shaft fractures - where are we today?

Humeral shaft fractures account for about 1-3% of all fractures. These fractures are regarded as the domain of non-surgical management. This is certainly still the contemporary view but there is an obvious trend towards surgical stabilization. Surgical treatment of humeral shaft fractures has nonetheless been greatly facilitated by the development of new implants. In particular, a new generation of nails that general permit immediate mobilization have become available for improved management of longitudinal and multi-segmental fractures. Retrograde and antegrade nails have advantages and disadvantages and selection procedure is often based on the distal or proximal location of the fracture. Plates also offer an alternative for certain indications and have advantages at the proximal and distal shaft in particular. If there is primary lesion of the radial nerve, exploration is not very advisable, but in the absence of remission exploration can be conducted after several months with the same degree of success. Since the published literature offers no comparative studies with a high level of evidence, our statement can only be regarded as an up-to-date recommendation in the hope that future prospective randomized studies will address this issue.

Seven ways to get a grip on implementing Competency-Based Medical Education at the program level.

Competency-based medical education (CBME) curricula are becoming increasingly common in graduate medical education. Put simply, CBME is focused on educational outcomes, is independent of methods and time, and is composed of achievable competencies.1 In spite of widespread uptake, there remains much to learn about implementing CBME at the program level. Leveraging the collective experience of program leaders at Queen's University, where CBME simultaneously launched across 29 specialty programs in 2017, this paper leverages change management theory to provide a short summary of how program leaders can navigate the successful preparation, launch, and initial implementation of CBME within their residency programs.

Les programmes de formation médicale fondée sur les compétences (FMFC) sont de plus en plus répandus dans les études supérieures en médecine. En termes simples, la FMFC est centrée sur les résultats scolaires, elle est indépendante des méthodes et du temps, et est constituée de compétences réalisables.1 Malgré cette adoption généralisée, il reste encore beaucoup à apprendre sur la mise en œuvre de la FMFC au niveau des programmes. Tirant profit de l'expérience collective des responsables de programmes à l'Université Queen, où la FMFC a été lancée simultanément dans 29 programmes de spécialité en 2017,le présent article s'appuie sur la théorie de la gestion du changement pour produire un court résumé de la manière dont les responsables de programmes peuvent gérer avec succès la préparation, le lancement et la mise en œuvre initiale de la FMFC au sein de leurs programmes de résidence.

Variance heterogeneity and genotype by environment interactions in native Black and White dual-purpose cattle for different herd allocation schemes.

Black and White dual-purpose cattle (DSN) are kept in diverse production systems, but the same set of genetic parameters is used for official national genetic evaluations, neglecting the herd or production system characteristics. The aim of the present study was to infer genetic (co)variance components within and across defined herd descriptor groups or clusters, considering only herds keeping the local and endangered DSN breed. The study considered 3659 DSN and 2324 Holstein Friesian (HF) cows from parities one to three. The 46 herds always kept DSN cows, but in most cases, herds were 'mixed' herds (Mixed), including both genetic lines HF and DSN. In order to study environmental sensitivity, we had a focus on the naturally occurring negative energy balance in the early lactation period. In consequence, traits were records from the 1st official test-day after calving for milk yield (Milk-kg), somatic cell score (SCS) and fat-to-protein ratio (FPR). Genetic parameters were estimated in bivariate runs (separate runs for the three genetic lines Mixed, HF and DSN), defining the same trait from different herd groups or clusters as different traits. Additive-genetic variances and heritabilities were larger in herd groups that indicated superior herd management, implying that cow records from these herds allow a better genetic differentiation. Superior herd management included larger herds, low calving age, high herd production levels and low intra-herd somatic cell count. Herd descriptor group differences in additive-genetic variances for Milk-kg were stronger in HF than in DSN, indicating environmental sensitivity for DSN. Similar variance components and heritabilities across groups, clusters and genetic lines were found for data stratification according to geographical descriptors altitude and latitude. Considering 72 bivariate herd group runs, 29 genetic correlations were very close to 1 (mostly for Milk-kg). Somatic cell score was the trait showing the smallest genetic correlations, especially in the DSN analyses, and when stratifying herds according to genetic line compositions (rg=0.11), or according to the percentage of natural service sires (rg=0.08). For estimations based on the results of a cluster analysis considering several herd descriptors simultaneously, indications for genotype × environment interactions could be found for SCS, but genetic correlations were larger than 0.80 for Milk-kg and FPR. In conclusion, we suggest multiple-trait animal model applications in genetic evaluations, in order to select the best sires for specific herd environments or herd clusters.