[Pre-Aug 2018] Canolfan Gogledd Cymru ar gyfer Ymchwil Gofal Cychwynnol

  1. Cyhoeddwyd

    Impact of investigations in general practice on timeliness of referral for patients subsequently diagnosed with cancer: analysis of national primary care audit data

    Rubin, G. P., Saunders, C. L., Abel, G. A., McPhail, S., Lyratzopoulos, G. & Neal, R. D., 20 Ion 2015, Yn: British Journal of Cancer. 112, t. 676-687

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  2. Cyhoeddwyd

    Research into practice: prompt diagnosis of cancer in primary care

    Rubin, G., Walter, F., Emery, J., Neal, R. D., Hamilton, W. & Wardle, J., 1 Awst 2014, Yn: British Journal of General Practice. 64, 625, t. 428-430

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  3. Cyhoeddwyd

    Development of a survey instrument to investigate the primary care factors related to differences in cancer diagnosis between international jurisdictions

    Rose, P. W., Hamilton, W., Aldersey, K., Barisic, A., Dawes, M., Foot, C., Grunfeld, E., Hart, N., Neal, R. D., Pirotta, M., Sisler, J., Thulesius, H., Vedsted, P., Young, J. & Rubin, G., 17 Meh 2014, Yn: BMC Family Practice. 2014, 15, t. 122

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  4. Cyhoeddwyd

    Explaining variation in cancer survival between 11 jurisdictions in the International Cancer Benchmarking Partnership: a primary care vignette survey

    Rose, P. W., Rubin, G., Perera-Salazar, R., Almberg, S. S., Barisic, A., Dawes, M., Grunfeld, E., Hart, N., Neal, R. D., Pirotta, M., Sisler, J., Konrad, G., Toftegaard, B. S., Thulesius, H., Vedsted, P., Young, J., Hamilton, W. & The ICBP Module 3 Working Group., N. V., 27 Mai 2015, Yn: BMJ Open. 5, 5

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  5. Cyhoeddwyd

    In Vitro Evaluation of the Interaction of Dextrin-Colistin Conjugates with Bacterial Lipopolysaccharide

    Roberts, J. L., Cattoz, B., Schweins, R., Beck, K., Thomas, D. W., Griffiths, P. C. & Ferguson, E. L., 5 Ion 2016, Yn: Journal of Medicinal Chemistry. 59, 2, t. 647-654

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  6. Cyhoeddwyd

    Symptoms, ultrasound imaging and biochemical markers alone or in combination for the diagnosis of ovarian cancer in women with symptoms suspicious of ovarian cancer

    Rai, N., Campaneria, R., Snell, K., Mallett, S., Bayliss, S. E., Neal, R. D., Balogun, M., Kehoe, S., Deeks, J. K., Sundar, S. & Davenport, C., 7 Rhag 2015, Yn: Cochrane Library. 2015, 12, CD011964.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  7. Cyhoeddwyd

    Trial of Optimal Personalised Care After Treatment for Gynaecological cancer (TOPCAT-G): a study protocol for a randomised feasibility trial

    Pye, K., Totton, N., Stuart, N., Whitaker, R., Morrison, V., Edwards, R. T., Yeo, S. T., Timmis, L. J., Butterworth, C., Hall, L., Rai, T., Hoare, Z., Neal, R. D., Wilkinson, C. & Leeson, S., 23 Tach 2016, Yn: Pilot and Feasibility Studies. 2, 67.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  8. Cyhoeddwyd

    What are the experiences of cancer care in gay, lesbian and bisexual patients, and how do these differ from heterosexual cancer patients?

    Plumpton, C. O., Neal, R. D., Hulbert-Williams, N., McHugh, R., Semlyen, J., Flowers, P., Storey, L., Ream, E. & Neal, R., 28 Ebr 2015, Yn: Psycho-Oncology. 24, S1, t. 2-3

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  9. Cyhoeddwyd

    Interview with Dr David Healy, 13 February 2013

    Peters, K. R., Katz, S. & Healy, D., 1 Mai 2015, Yn: Dementia. 14, 3, t. 361-369

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  10. Cyhoeddwyd

    GPs' views on changing the law on physician-assisted suicide and euthanasia, and willingness to prescribe or inject lethal drugs: a survey from Wales

    Pasterfield, D., Wilkinson, C., Finlay, I. G., Neal, R. D. & Hulbert, N. J., Meh 2006, Yn: British Journal of General Practice. 56, 527, t. 450-2 3 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  11. Cyhoeddwyd

    Identifying patients with a cancer diagnosis using general practice medical records and Cancer Registry data

    Pascoe, S. W., Neal, R. D., Heywood, P. L., Allgar, V. L., Miles, J. N., Ansell, P. E. & Stefoski-Mikeljevic, J., 1 Awst 2008, Yn: Family Practice. 25, 4, t. 215-220

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  12. Cyhoeddwyd

    Deterministic nonlinear features of cutaneous perfusion are lost in diabetic subjects with neuropathy

    Parthimos, D., Schmiedel, O., Harvey, J. N. & Griffith, T. M., 1 Gorff 2011, Yn: Microvascular Research. 82, 1, t. 42-51

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  13. Cyhoeddwyd

    Experiences of follow-up after treatment in patients with prostate cancer: a qualitative study

    O'Brien, R., Rose, P. W., Campbell, C., Weller, D., Neal, R. D., Wilkinson, C., Watson, E. K. & Prostate Cancer Follow-up Group, Hyd 2010, Yn: BJUI International. 106, 7, t. 998-1003 6 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  14. Cyhoeddwyd

    Qualitative "trial-sibling" studies and "unrelated" qualitative studies contributed to complex intervention reviews

    Noyes, J., Hendry, M., Lewin, S., Glenton, C., Chandler, J. & Rashidian, A., Meh 2016, Yn: Journal of Clinical Epidemiology. 74, t. 133-143

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  15. Cyhoeddwyd

    International variation in adherence to referral guidelines for suspected cancer: a secondary analysis of survey data

    Nicholson, B. D., Mant, D., Neal, R. D., Hart, N., Hamilton, W., Shinkins, B., Rubin, G. & Rose, P. W., 7 Ion 2016, Yn: British Journal of General Practice. 66, 643, t. E106-E113

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  16. Cyhoeddwyd

    Excision of malignant melanomas in North Wales: effect of location and surgeon on time to diagnosis and quality of excision

    Neal, R. D., Cannings-John, R. L., Hood, K., Sowden, J., Lawrence, H., Jones, C. & Jones, J., 1 Awst 2008, Yn: Family Practice. 25, 4, t. 221-227

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  17. Cyhoeddwyd

    Clinical features of kidney cancer in primary care: a case-control study using primary care records

    Neal, R. D., Shepherd, E., Neal, R., Rose, P., Walter, F. & Hamilton, W. T., 1 Ebr 2013, Yn: British Journal of General Practice. 63, 609, t. e250-e255

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  18. Cyhoeddwyd

    Do diagnostic delays in cancer matter?

    Neal, R. D., 1 Ion 2009, Yn: British Journal of Cancer. 101, t. S9-S12

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  19. Cyhoeddwyd

    NICE prostate cancer clinical guideline: implications for primary care

    Neal, R. D., 1 Medi 2008, Yn: British Journal of General Practice. 58, 554, t. 607-708

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  20. Cyhoeddwyd

    An Association of Cancer Physicians' strategy for improving services and outcomes for cancer patients

    Neal, R. D., Baird, R., Banks, I., Cameron, D., Chester, J., Earl, H., Flannagan, M., Januszewski, A., Kennedy, R., Payne, S., Samuel, E., Taylor, H., Agarwal, R., Ahmed, S., Archer, C., Board, R., Carser, J., Copson, E., Cunningham, D., Coleman, R., Glaser, A., Griffiths, R., Hall, G., Hall, M., Harari, D., Hawkins, M., Hill, M., Johnson, P., Jones, A., Kalsi, T., Karapanagiotou, E., Kemp, Z., Mansi, J., Marshall, E., Mitchell, A., Moe, M., Michie, C., Neal, R., Newsom-Davis, T., Norton, A., Osborne, R., Patel, G., Radford, J., Ring, A., Shaw, E., Skinner, R., Stark, D., Turnbull, S., Velikova, G., White, J., Young, A., Joffe, J. & Selby, P., 5 Ion 2016, Yn: Ecancermedical Science. 10, 608

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  21. Cyhoeddwyd

    The complexity and difficulty of diagnosing lung cancer: findings from a national primary-care study in Wales

    Neal, R. D., Robbie, I. J., Lewis, M., Williamson, I. & Hanson, J., 1 Medi 2015, Yn: Primary Health Care Research and Development. 16, 05, t. 436-449

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  22. Cyhoeddwyd

    The role of the GP in prostate cancer care

    Neal, R. D., 1 Medi 2008, Yn: Trends in Urology, Gynaecology and Sexual Health. 13, 5, t. 27-30

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  23. Cyhoeddwyd

    Is increased time to diagnosis and treatment in symptomatic cancer associated with poorer outcomes? Systematic review

    Neal, R. D., Tharmanathan, P., France, B., Din, N. U., Cotton, S., Fallon-Ferguson, J., Hamilton, W., Hendry, A., Hendry, M., Lewis, R., Macleod, U., Mitchell, E. D., Pickett, M., Rai, T., Shaw, K., Stuart, N., Tørring, M. L., Wilkinson, C., Williams, B., Williams, N. & Emery, J., 31 Maw 2015, Yn: British Journal of Cancer. 112 , Suppl 1, t. S92-107

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  24. Cyhoeddwyd

    Comparison of cancer diagnostic intervals before and after implementation of NICE guidelines: analysis of data from the UK General Practice Research Database

    Neal, R. D., Din, N. U., Hamilton, W., Ukoumunne, O. C., Carter, B., Stapley, S. & Rubin, G., 4 Chwef 2014, Yn: British Journal of Cancer. 110, 3, t. 584–592 9 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  25. Cyhoeddwyd

    Has evidence-based medicine left quackery behind?

    Naudet, F., Falissard, B., Boussageon, R. & Healy, D., 1 Ebr 2015, Yn: Internal and Emergency Medicine. 10, 5, t. 631-634

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  26. Cyhoeddwyd

    The evaluation of the National Exercise Referral Scheme in Wales

    Murphy, S. M., Raisanen, L., Moore, G., Edwards, R., Linck, P., Hounsome, N., Williams, N., Din, N. & Moore, L., 2010, Welsh Government. (Social research; Rhif Number: 07/2010)

    Allbwn ymchwil: Llyfr/AdroddiadAdoddiad Arall

  27. Cyhoeddwyd

    An evaluation of the effectiveness and cost effectiveness of the National Exercise Referral Scheme in Wales, UK: a randomised controlled trial of a public health policy initiative

    Murphy, S. M., Edwards, R. T., Williams, N., Raisanen, L., Moore, G., Linck, P., Hounsome, N., Din, N. U. & Moore, L., Awst 2012, Yn: Journal of Epidemiology and Community Health. 66, 8, t. 745-753 9 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  28. Cyhoeddwyd

    A pragmatic randomised controlled trial of the Welsh National Exercise Referral Scheme: protocol for trial and integrated economic and process evaluation: protocol for trial and integrated economic and process evaluation

    Murphy, S., Raisanen, L., Moore, G., Edwards, R. T., Linck, P., Williams, N., Din, N., Hale, J., Roberts, C., McNaish, E. & Moore, L., 18 Meh 2010, Yn: BMC Public Health. 10, 352, t. 352

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  29. Cyhoeddwyd

    Patient preferences and National Health Service costs: a cost-consequences analysis of cancer genetic services.

    Morrison, V. L., Wilkinson, C. E., Griffith, G. L., Edwards, R. T., Williams, J. M., Gray, J., Morrison, V., Wilkinson, C., Turner, J., France, B. & Bennett, P., 1 Rhag 2009, Yn: Familial Cancer. 8, 4, t. 265-275

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  30. Cyhoeddwyd

    The Mini-Mental Adjustment to Cancer Scale: re-analysis of its psychometric properties in a sample of 160 mixed cancer patients

    Morrison, V. L., Neal, R. D., Wilkinson, C. E., Hulbert-Williams, N. J., Hulbert-Williams, L., Morrison, V. N. & Wilkinson, C., 1 Gorff 2012, Yn: Psycho-Oncology. 21, 7, t. 792-797

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  31. Cyhoeddwyd

    Mixed-method process evaluation of the Welsh National Exercise Referral Scheme

    Moore, G., Raisanen, L., Moore, L., Din, N. & Murphy, S., 2013, Yn: Health Education. 113, 6, t. 476-501

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  32. Cyhoeddwyd

    The relative length of the patient and the primary care interval in patients with 28 common and rarer cancers

    Lyratzopoulos, G., Saunders, C. L., Abel, G. A., McPhail, S. M., Neal, R. D., Wardle, J. & Rubin, G. P., 3 Maw 2015, Yn: British Journal of Cancer. 112, t. S35–S40

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  33. Cyhoeddwyd

    Measures of promptness of cancer diagnosis in primary care: secondary analysis of national audit data on patients with 18 common and rarer cancers

    Lyratzopoulos, G., Abel, G. A., McPhail, S., Neal, R. D. & Rubin, G. P., 19 Chwef 2013, Yn: British Journal of Cancer. 108, t. 686–690

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  34. Cyhoeddwyd

    Gender inequalities in the promptness of diagnosis of bladder and renal cancer after symptomatic presentation: evidence from secondary analysis of an English primary care audit survey

    Lyratzopoulos, G., Abel, G. A., McPhail, S., Neal, R. D. & Rubin, G. P., 24 Meh 2013, Yn: BMJ Open. 3, t. e002861

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  35. Cyhoeddwyd

    Variation in number of general practitioner consultations before hospital referral for cancer: findings from the 2010 National Cancer Patient Experience Survey in England

    Lyratzopoulos, G., Neal, R. D., Barbiere, J. M., Rubin, G. & Abel, G., 1 Ebr 2012, Yn: Lancet Oncology. 13, 4, t. 353-365

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  36. Cyhoeddwyd

    Religion and psychosis: the effect of the Welsh religious revival in 1904-1905.

    Linden, S., Harris, M., Whitaker, C. J. & Healy, D., 1 Awst 2010, Yn: Psychological Medicine. 40, 8, t. 1317-1323

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  37. Cyhoeddwyd

    Real-Time Self-Regulation of Emotion Networks in Patients with Depression

    Linden, D., Linden, D. E., Habes, I., Johnston, S. J., Linden, S., Tatineni, R., Subramanian, L., Sorger, B., Healy, D. & Goebel, R., 4 Meh 2012, Yn: PLoS ONE. 7, 6, t. e38115

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  38. Cyhoeddwyd

    Cost-effectiveness of a national exercise referral programme for primary care patients in Wales: results of a randomised controlled trial

    Linck, P. G., Williams, N. H., Edwards, R. T., Linck, P., Hounsome, N., Raisanen, L., Williams, N., Moore, L. & Murphy, S., 29 Hyd 2013, Yn: BMC Public Health. 13, t. 1021

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  39. Cyhoeddwyd

    Enhancing ventilation in homes of children with asthma: cost-effectiveness study alongside randomised controlled trial

    Linck, P. G., Edwards, R. T., Neal, R. D., Linck, P., Bruce, N., Mullock, L., Nelhans, N., Pasterfield, D., Russell, D., Russell, I. & Woodfine, L. O., 1 Tach 2011, Yn: British Journal of General Practice. 61, 592, t. e733-e741

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  40. Cyhoeddwyd

    Enhancing ventilation in homes of children with asthma: pragmatic randomised controlled trial

    Linck, P. G., Woodfine, L., Neal, R. D., Bruce, N., Edwards, R. T., Linck, P., Mullock, L., Nelhans, N., Pasterfield, D., Russell, D. & Russell, I. O., 1 Tach 2011, Yn: British Journal of General Practice. 61, 592, t. e724-e732

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  41. Cyhoeddwyd

    Follow-up of cancer in primary care versus secondary care: systematic review

    Lewis, R. A., Neal, R. D., Williams, N. H., France, B., Hendry, M., Russell, D., Hughes, D. A., Russell, I., Stuart, N. S. A., Weller, D. & Wilkinson, C., 1 Gorff 2009, Yn: British Journal of General Practice. 59, 564, t. e234-e247

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  42. Cyhoeddwyd

    Patients' and healthcare professionals' views of cancer follow-up: systematic review

    Lewis, R., Neal, R. D., Hendry, M., France, B., Williams, N. H., Russell, D., Hughes, D. A., Russell, I., Stuart, N. S. A., Weller, D. & Wilkinson, C., Gorff 2009, Yn: British Journal of General Practice. 59, 564, t. e248-e259

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  43. Cyhoeddwyd

    The clinical effectiveness and cost-effectiveness of management strategies for sciatica: systematic review and economic model

    Lewis, R., Williams, N. H., Williams, N., Din, N., Fitzsimmons, D., Phillips, C., Jones, M., Sutton, A., Burton, K., Nafees, S., Hendry, M., Rickard, I., Chakraverty, R. & Wilkinson, C. E., Tach 2011, Yn: Health Technology Assessment. 15, 39, t. 1-578 578 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  44. Cyhoeddwyd

    Pragmatic methods for reviewing exceptionally large bodies of evidence: systematic mapping review and overview of systematic reviews using lung cancer survival as an exemplar

    Lewis, R., Hendry, M., Din, N., Stanciu, M. A., Nafees, S., Hendry, A., Teoh, Z. H., Lloyd, T., Parsonage, R., Neal, R. D., Collier, G. & Huws, D. W., 16 Gorff 2019, Yn: Systematic Reviews. 8, 1, 171.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  45. Cyhoeddwyd

    The Hip & Knee Book

    Lewis, R. A., Wilkinson, C. E., Neal, R. D., Williams, N. H., Williams, N., Amoakwa, E., Burton, K., Hendry, M., Lewis, R., Jones, J., Bennett, P., Neal, R., Andrew, G. & Wilkinson, C., 1 Ion 2009, The Stationary Office.

    Allbwn ymchwil: Llyfr/AdroddiadLlyfr

  46. Cyhoeddwyd

    Intensive glycaemic control in type 2 diabetes: where are we now?

    Lee, S. & Harvey, J. N., 1 Rhag 2011, Yn: Prescriber. 22, 23-24, t. 6-8

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  47. Cyhoeddwyd

    Restoring Study 329: efficacy and harms of paroxetine and imipramine in treatment of major depression in adolescence

    Le Noury, J. C., Nardo, J. M., Healy, D., Jureidini, J., Raven, M., Tufanaru, C. & Abi-Jaoude, E., 16 Medi 2015, Yn: BMJ. 351, h4320.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  48. Cyhoeddwyd

    The incidence of admissions for schizophrenia and related psychoses in two cohorts: 1875–1924 and 1994–2010

    Le Noury, J. C., Healy, D., Le Noury, J., Linden, S. C., Harris, M., Whitaker, C. J., Linden, D., Baker, D. & Roberts, A. P., 19 Ion 2012, Yn: BMJ Open. 2, 1, t. e000447

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  49. Cyhoeddwyd

    Mediation by illness perceptions of the effect of personality and health threat communication on coping with the diagnosis of diabetes

    Lawson, V. L., Bundy, C., Belcher, J. & Harvey, J. N., 1 Medi 2010, Yn: British Journal of Health Psychology. 15, 3, t. 623-642

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  50. Cyhoeddwyd

    The Effects of Aerobic and Resistance Exercise on Markers of Large Joint Health in Stable Rheumatoid Arthritis Patients: A pilot study

    Law, R-J., Saynor, Z. L., Gabbitas, J., Jones, J., Kraus, A., Breslin, A., Maddison, P. J. & Thom, J. M., 7 Rhag 2015, Yn: Musculoskeletal Care. 13, 4, t. 222-235

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid