Abstract: The inner ∼200 pc region of the Galaxy contains a 4 million M ⊙ supermassive black hole (SMBH), significant quantities of molecular gas, and star formation and cosmic-ray energy densities that are roughly two orders of magnitude higher than the corresponding levels in the Galactic disk. At a distance of only 8.2 kpc, the region presents astronomers with a unique opportunity to study a diverse range of energetic astrophysical phenomena, from stellar objects in extreme environments, to the SMBH and star-formation-driven feedback processes that are known to influence the evolution of galaxies as a whole. We present a new survey of the Galactic center conducted with the South African MeerKAT radio telescope. Radio imaging offers a view that is unaffected by the large quantities of dust that obscure the region at other wavelengths, and a scene of striking complexity is revealed. We produce total-intensity and spectral-index mosaics of the region from 20 pointings (144 hr on-target in total), covering 6.5 square degrees with an angular resolution of 4″ at a central frequency of 1.28 GHz. Many new features are revealed for the first time due to a combination of MeerKAT’s high sensitivity, exceptional u , v -plane coverage, and geographical vantage point. We highlight some initial survey results, including new supernova remnant candidates, many new nonthermal filament complexes, and enhanced views of the Radio Arc bubble, Sagittarius A, and Sagittarius B regions. This project is a South African Radio Astronomy Observatory public legacy survey, and the image products are made available with this article.

Abstract: The recent pandemic has seen unprecedented demand for respiratory support of patients with COVID‐19 pneumonia, stretching services and clinicians. Yet despite the global numbers of patients treated, guidance is not clear on the correct choice of modality or the timing of escalation of therapy for an individual patient.This narrative review assesses the available literature on the best use of different modalities of respiratory support for an individual patient, and discusses benefits and risks of each, coupled with practical advice to improve outcomes. On current data, in an ideal context, it appears that as disease severity worsens, conventional oxygen therapy is not sufficient alone. In more severe disease, i.e. PaO2/FiO2 ratios below approximately 200, helmet‐CPAP (continuous positive airway pressure) (although not widely available) may be superior to high‐flow nasal cannula (HFNC) therapy or facemask non‐invasive ventilation (NIV)/CPAP, and that facemask NIV/CPAP may be superior to HFNC, but with noted important complications, including risk of pneumothoraces. In an ideal context, invasive mechanical ventilation should not be delayed where indicated and available. Vitally, the choice of respiratory support should not be prescriptive but contextualised to each setting, as supply and demand of resources vary markedly between institutions. Over time, institutions should develop clear policies to guide clinicians before demand exceeds supply, and should frequently review best practice as evidence matures.

Abstract: 〈 p 〉 〈 strong 〉 List of Abstract Titles and authors: 〈 br / 〉 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 1. Psychosis: A matter of mental effort? 〈 /strong 〉 〈 /p 〉 〈 p 〉 M Borg, Y Y van der Zee, J H Hsieh, H Temmingh, D J Stein, F M Howells 〈 /p 〉 〈 p 〉 〈 strong 〉 2.In search of an affordable, effective post-discharge intervention: A randomised control trial assessing the influence of a telephone-based intervention on readmissions for patients with severe mental illness in a developing country 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 U A Botha, L Koen, M Mazinu, E Jordaan, D J H Niehaus 〈 /p 〉 〈 p 〉 〈 strong 〉 3. The effect of early abstinence from long-term methamphetamine use on brain metabolism using 1H-magnetic resonance spectro-scopy (1H-MRS) 〈 /strong 〉 〈 /p 〉 〈 p 〉 A Burger, S Brooks, D J Stein, F M Howells 〈 /p 〉 〈 p 〉 〈 strong 〉 4. The effect of 〈 em 〉 in utero exposure  〈 /em 〉 to methamphetamine on brain metabolism in childhood using 1H-magnetic resonance spectroscopy (1H-MRS) 〈 /strong 〉 〈 /p 〉 〈 p 〉 A Burger, A Roos, M Kwiatkowski, D J Stein, K A Donald, F M Howells 〈 /p 〉 〈 p 〉 〈 strong 〉 5. A prospective study of clinical, biological and functional aspects of outcome in first-episode psychosis: The EONKCS Study 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 B Chiliza, L Asmal, R Emsley 〈 /p 〉 〈 p 〉 〈 strong 〉 6. Stimulants as cognitive enhancers - perceptions v. evidence in a very real world 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 H M Clark 〈 /p 〉 〈 p 〉 〈 strong 〉 7. Pharmacogenomics in antipsychotic drugs 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 Ilse du Plessis 〈 /p 〉 〈 p 〉 〈 strong 〉 8. Serotonin in anxiety disorders and beyond 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 Ilse du Plessis 〈 /p 〉 〈 p 〉 〈 strong 〉 9. HIV infection results in ventral-striatal reward system hypo-activation during cue processing 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 S du Plessis, M Vink, J A Joska, E Koutsilieri, A Bagadia, D J Stein, R Emsley 〈 /p 〉 〈 p 〉 〈 strong 〉 10. Disease progression in schizophrenia: Is the illness or the treatment to blame? 〈 /strong 〉 〈 /p 〉 〈 p 〉 R Emsley, M J Sian 〈 /p 〉 〈 p 〉 〈 strong 〉 11. Serotonin transporter variants play a role in anxiety sensitivity in South African adolescents 〈 /strong 〉 〈 /p 〉 〈 p 〉  S M J Hemmings, L I Martin, L van der Merwe, R Benecke, K Domschke, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 12. Iron deficiency in two children diagnosed with multiple sclerosis: Report on whole exom sequencing 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 S Janse van Rensburg, R van Toorn, J F Schoeman, A Peeters, L R Fisher, K Moremi, M J Kotze 〈 /p 〉 〈 p 〉 〈 strong 〉 13. Benzodiazepines: Practical pharmacokinetics 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 P Joubert 〈 /p 〉 〈 p 〉 〈 strong 〉 14. What to consider when prescribing psychotropic medications 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 G Lippi 〈 /p 〉 〈 p 〉 〈 strong 〉 15. Current prescribing practices for obsessive-compulsive disorder in South Africa: Controversies and consensus 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 C Lochner, L Taljaard, D J Stein 〈 /p 〉 〈 p 〉 〈 strong 〉 16. Correlates of emotional and behavioural problems in children with preinatally acquired HIV in Cape Town, South Africa 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 K-A Louw, N Phillips, JIpser, J Hoare 〈 /p 〉 〈 p 〉 〈 strong 〉 17. The role of non-coding RNAs in fear extinction 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 S Malan-Muller, L Fairbairn, W M U Daniels, M J S Dashti, E J Oakleley, M Altorfer, J Harvey, S Seedat, J Gamieldien, S M J Hemmings 〈 /p 〉 〈 p 〉 〈 strong 〉 18. An analysis of the management og HIV-mental illness comorbidity at the psychiatric unit of the Dr George Mukhari Academic Hospital 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 M L Maodi, S T Rataemane, T Kyaw 〈 /p 〉 〈 p 〉 〈 strong 〉 19. The identification of novel genes in anxiety disorders: A gene X environment correlation and interaction study 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 N W McGregor, J Dimatelis, S M J Hemmings, C J Kinnear, D J Stein, V Russel, C Lochner 〈 /p 〉 〈 p 〉 〈 strong 〉 20. Collaborations between conventional medicine and traditional healers: Obstacles and possibilities 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 G Nortje, S Seedat, O Gureje 〈 /p 〉 〈 p 〉 〈 strong 〉 21. Thought disorder and form perception: Relationships with symptoms and cognitive function in first-episode schizophrenia 〈 /strong 〉 〈 /p 〉 〈 p 〉 M R Olivier, R Emsley 〈 /p 〉 〈 p 〉 〈 strong 〉 22. Investigating the functional significance of genome-wide variants associated with antipsychotic treatment response 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 E Ovenden, B Drogemoller, L van der Merwe, R Emsley, L Warnich 〈 /p 〉 〈 p 〉 〈 strong 〉 23. The moral and bioethical determinants of "futility" in psychiatry 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 W P Pienaar 〈 /p 〉 〈 p 〉 〈 strong 〉 24. Single voxel proton magnetic resonance spectroscopy (1H-MRS) and volumetry of the amylgdala in social anxiety disorder in the context of early developmental trauma 〈 /strong 〉 〈 /p 〉 〈 p 〉 D Rosenstein, A T Hess, J Zwart, F Ahmed-Leitao, E Meintjies, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 25. Schizoaffective disorder in an acute psychiatric unit: Profile of users and agreement with Operational Criteria (OPCRIT) 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 R R Singh, U Subramaney 〈 /p 〉 〈 p 〉 〈 strong 〉 26. The right to privacy and confidentiality: The ethics of expert diagnosis in the public media and the Oscar Pistorius trial 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 C Smith 〈 /p 〉 〈 p 〉 〈 strong 〉 27. A birth cohort study in South Africa: A psychiatric perspective 〈 /strong 〉 〈 /p 〉 〈 p 〉 D J Stein 〈 /p 〉 〈 p 〉 〈 strong 〉 28. 'Womb Raiders': Women referred for observation in terms of the Criminal Procedures Act (CPA) charged with fetal abduction and murder 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 U Subramaney 〈 /p 〉 〈 p 〉 〈 strong 〉 29. Psycho-pharmacology of sleep wake disorders: An update 〈 /strong 〉 〈 /p 〉 〈 p 〉 R Sykes 〈 /p 〉 〈 p 〉 〈 strong 〉 30. Refugee post-settlement in South Africa: Role of adjustment challenges and family in mental health outcomes 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 L Thela, A Tomita, V Maharaj, M Mhlongo, K Jonathan 〈 /p 〉 〈 p 〉 〈 strong 〉 31. Dstinguishing ADHD symptoms in psychotic disorders: A new insight in the adult ADHD questionnaire 〈 /strong 〉 〈 /p 〉 〈 p 〉 Y van der Zee, M Borg, J H Hsieh, H Temmingh, D J Stein, F M Howells 〈 /p 〉 〈 p 〉 〈 strong 〉 32. Oscar Pistorius ethical dilemmas in a trial by media: Does this include psychiatric evaluation by media? 〈 /strong 〉 〈 /p 〉 〈 p 〉 M Vorster 〈 /p 〉 〈 p 〉 〈 strong 〉 33. Genetic investigation of apetite aggression in South African former young offenders: The involvement of serotonin transporter gene 〈 /strong 〉 〈 /p 〉 〈 p 〉 K Xulu, J Somer, M Hinsberger, R Weierstall, T Elbert, S Seedat, S Hemmings 〈 /p 〉 〈 p 〉 〈 strong 〉 34. Effects of HIV and childhood trauma on brain morphemtry and neurocognitive function 〈 /strong 〉 〈 /p 〉 〈 p 〉 G Spies, F Ahmed-Leitao, C Fennema-Notestine, M Cherner, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 35. Measuring intentional behaviour normative data of a newly developed motor task battery 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 S Bakelaar, J Blampain, S Seedat, J van Hoof, Y Delevoye-Turrel 〈 /p 〉 〈 p 〉 〈 strong 〉 36. Resilience in social anxiety disorder and post-traumatic stress disorder in the context of childhood trauma 〈 /strong 〉 〈 /p 〉 〈 p 〉 M Bship, S Bakelaar, D Rosenstein, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 37. The ethical dilemma of seclusion practices in psychiatry 〈 /strong 〉 〈 /p 〉 〈 p 〉 G Chiba, U Subramaney 〈 /p 〉 〈 p 〉 〈 strong 〉 38. Physical activity and neurological soft signs in patients with schizophrenia 〈 /strong 〉 〈 /p 〉 〈 p 〉 O Esan, C Osunbote, I Oladele, S Fakunle, C Ehindero 〈 /p 〉 〈 p 〉 〈 strong 〉 39. A retrospective study of completed suicides in the Nelson Mandela Bay Metropolitan Area from 2008 to 2013 - preliminary results 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 C Grobler, J Strumpher, R Jacobs 〈 /p 〉 〈 p 〉 〈 strong 〉 40. Serotonin transporter variants play a role in anxiety sensitivity in South African adolescents 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 S M J Hemmings, L I Martin, L van der Merwe, R Benecke, K Domschke, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 41. Investigation of variants within antipsychotic candidate pharmacogenes associated with treatment outcome 〈 /strong 〉 〈 /p 〉 〈 p 〉 F Higgins, B Drogmoller, G Wright, L van der Merwe, N McGregor, B Chiliza, L Asmal, L Koen, D Niehaus, R Emsley, L Warnich 〈 /p 〉 〈 p 〉 〈 strong 〉 42. Effects of diet, smoking and alcohol consumption on disability (EDSS) in people diagnosed with multiple sclerosis 〈 /strong 〉 〈 /p 〉 〈 p 〉 S Janse van Rensburg, W Davis, D Geiger, F J Cronje, L Whati, M Kidd, M J Kotze 〈 /p 〉 〈 p 〉 〈 strong 〉 43. The clinical utility of neuroimaging in an acute adolescnet psychiatric inpatient population 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 Z Khan, A Lachman, J Harvey 〈 /p 〉 〈 p 〉 〈 strong 〉 44. Relationships between childhood trauma (CT) and premorbid adjustment (PA) in a highly traumatised sample of patients with first-episode schizophrenia (FES 〈 /strong 〉 ) 〈 /p 〉 〈 p 〉 S Kilian, J Burns, S Seedat, L Asmal, B Chiliza, S du Plessis, R Olivier, R Emsley 〈 /p 〉 〈 p 〉 〈 strong 〉 45. Functional and cognitive outcomes using an mTOR inhibitor in an adolescent with TSC 〈 /strong 〉 〈 /p 〉 〈 p 〉 A Lachman, C van der Merwe, P Boyes, P de Vries 〈 /p 〉 〈 p 〉 〈 strong 〉 46. Perceptions about adolescent body image and eating behaviour 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 K Laxton, A B R Janse van Rensburg 〈 /p 〉 〈 p 〉 〈 strong 〉 47. Clinical relevance of FTO rs9939609 as a determinant of cardio-metabolic risk in South African patients with major depressive disorder 〈 /strong 〉 〈 /p 〉 〈 p 〉 H K Luckhoff, M J Kotze 〈 /p 〉 〈 p 〉 〈 strong 〉 48. Childhood abuse and neglect as predictors of deficits in verbal auditory memory in non-clinical adolescents with low anxiety proneness 〈 /strong 〉 〈 /p 〉 〈 p 〉 L Martin, K Martin, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 49. The changes of pro-inflammatory cytokines in a prenatally stressed febrile seizure animal model and whether 〈 em 〉 Rhus chirindensis 〈 /em 〉 may attenuate these changes 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 A Mohamed, M V Mabandla, L Qulu 〈 /p 〉 〈 p 〉 〈 strong 〉 50. Influence of TMPRSS6 A736v and HFE C282y on serum iron parameters and age of onset in patients with multiple sclerosis 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 K E Moremi, M J Kotze, H K Luckhoff, L R Fisher, M Kidd, R van Toorn, S Janse van Rensburg 〈 /p 〉 〈 p 〉 〈 strong 〉 51. Polypharmacy in pregnant women with serious mental illness 〈 /strong 〉 〈 /p 〉 〈 p 〉 E Thomas, E du Toit, L Koen, D Niehaus 〈 /p 〉 〈 p 〉 〈 strong 〉 52. Infant attachment and maternal depression as predictors of neurodevelopmental and behavioural outcomes at follow-up 〈 /strong 〉 〈 /p 〉 〈 p 〉 J Nothling, B Laughton, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 53. Differences in abuse, neglect and exposure to community violence in adolescents with and without PTSD 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 J Nothling, S Suliman, L Martin, C Simmons, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 54. Assessment of oxidative stress markers in children with autistic spectrum disorders in Lagos, Nigeria 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 Y Oshodi, O Ojewunmi, T A Oshodi, T Ijarogbe, O F Aina, J Okpuzor, O C F E A Lesi 〈 /p 〉 〈 p 〉 〈 strong 〉 55. Change in diagnosis and management of 'gender identity disorder' in pre-adolescent children 〈 /strong 〉 〈 /p 〉 〈 p 〉 S Pickstone-Taylor 〈 /p 〉 〈 p 〉 〈 strong 〉 56. Brain network connectivity in women exposed to intimate partner violence 〈 /strong 〉 〈 /p 〉 〈 p 〉 A Roos, J-P Fouche, B Vythilingum, D J Stein 〈 /p 〉 〈 p 〉 〈 strong 〉 57. Prolonged exposure treatment for PTSD in a Third-World, task-shifting, community-based environment 〈 /strong 〉 〈 /p 〉 〈 p 〉 J Rossouw, E Yadin, I Mbanga, T Jacobs, W Rossouw, D Alexander, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 58. Contrasting effects of early0life stress on mitochondrial energy-related proteins in striatum and hippocampus of a rat model of attention-deficit/ hyperactivity disorder 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 V Russell, J Dimatelis, J Womersley, T-L Sterley 〈 /p 〉 〈 p 〉 〈 strong 〉 59. Attention-deficit hyperactivity disorder in adults: A South African perspective 〈 /strong 〉 〈 /p 〉 〈 p 〉 R Schoeman, M de Klerk, M Kidd 〈 /p 〉 〈 p 〉 〈 strong 〉 60. Cognitive function in women with HIV infection and early-life stress 〈 /strong 〉 〈 /p 〉 〈 p 〉 G Spies, C Fennema-Notestine, M Cherner, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 61. Changes in functional connectivity networks in bipolar disorder patients after mindfulness-based cognitic therapy 〈 /strong 〉 〈 /p 〉 〈 p 〉 J A Starke, C F Beckmann, N Horn 〈 /p 〉 〈 p 〉 〈 strong 〉 62. Post-traumatic stress disorder, overweight and obesity: A systematic review and meta-analysis 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 〈 /strong 〉 S Suliman, L Anthonissen, J Carr, S du Plessis, R Emsley, S M J Hemmings, C Lochner, N McGregor L van den Heuvel, S Seedat 〈 /p 〉 〈 p 〉 〈 strong 〉 63. The brain and behaviour in a third-trimester equivalent animal model of fetal alcohol spectrum disorders 〈 /strong 〉 〈 /p 〉 〈 p 〉 P C Swart, C B Currin, J J Dimatelis, V A Russell 〈 /p 〉 〈 p 〉 〈 strong 〉 64. Irritability Assessment Model (IAM) to monitor irritability in child and adolescent psychiatric disorders. 〈 /strong 〉 〈 /p 〉 〈 p 〉 D van der Westhuizen 〈 /p 〉 〈 p 〉 〈 strong 〉 65. Outcome of parent-adolescent training in chilhood victimisation: Adaptive functioning, psychosocial and physiological variables 〈 /strong 〉 〈 /p 〉 〈 p 〉 D van der Westhuizen 〈 /p 〉 〈 p 〉 〈 strong 〉 66. The effect of ketamine in the Wistar-Kyoto and Sprague Dawley rat models of depression 〈 /strong 〉 〈 /p 〉 〈 p 〉 P J van Zyl, J J Dimatelis, V A Russell 〈 /p 〉 〈 p 〉 〈 strong 〉 67. Investigating COMT variants in anxiety sensitivity in South African adolescents 〈 /strong 〉 〈 /p 〉 〈 p 〉 L J Zass, L Martin, S Seedat, S M J Hemmings 〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉 〈 strong 〉 〈 br / 〉 〈 /strong 〉 〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉   〈 /p 〉

Abstract: CCQM-K125 was organized by the Inorganic Analysis Working Group (IAWG) of CCQM to assess and document the capabilities of the national metrology institutes (NMIs) or the designated institutes (DIs) to measure the mass fractions of trace elements (K, Cu and I) in infant formula. Government Laboratory, Hong Kong SAR (GLHK) acted as the coordinating laboratory. In CCQM-K125, 25 institutes submitted the results for potassium, 24 institutes submitted the results for copper and 8 institutes submitted the results for iodine. For examination of potassium and copper, most of the participants used microwave-assisted acid digestion methods for sample dissolution. A variety of instrumental techniques including inductively coupled plasma mass spectrometry (ICP-MS), isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS), inductively coupled plasma optical emission spectrometry (ICP-OES), atomic absorption spectrometry (AAS), flame atomic emission spectrometry (FAES) and microwave plasma atomic emission spectroscopy (MP-AES) were employed by the participants for determination. For analysis of iodine, most of the participants used alkaline extraction methods for sample preparation. ICP-MS and ID-ICP-MS were used by the participants for the determination. Generally, the participants' results of CCQM-K125 were found consistent for all measurands according to their equivalence statements. Except with some extreme values, most of the participants obtained the values of d i / U ( d i ) within ± 1 for the measurands. Main text To reach the main text of this paper, click on Final Report . Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/ . The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).