1. 2022
2. Cyhoeddwyd

   Standards of conduct and reporting in evidence syntheses that could inform environmental policy and management decisions

   Pullin, A. S., Cheng, S. H., Jackson, J. DU., Eales, J., Envall, I., Fada, S. J., Frampton, G. K., Harper, M., Kadykalo, A. N., Kohl, C., Konno, K., Livoreil, B., Ouédraogo, D-Y., O’Leary, B. C., Pullin, G., Randall, N., Rees, R., Smith, A., Sordello, R., Sterling, E. J., Twardek, W. M. & Woodcock, P., 19 Ebr 2022, Yn: Environmental Evidence. 11, 1, 16.

   Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

3. Cyhoeddwyd

   Hydrological Perspectives on Integrated, Coordinated, Open, Networked (ICON) Science

   Acharya, B., Ahmmed, B., Chen, Y., Davison, J., Haygood, L., Hensley, R., Kumar, R., Lerback, J., Liu, H., Mehan, S., Mehana, M., Patil, S., Persaud, B., Sullivan, P. & URycki, D., 12 Ebr 2022, Yn: Earth and Space Science. 9, 4, e2022EA002320.

   Allbwn ymchwil: Cyfraniad at gyfnodolyn › Sylw/Dadl › adolygiad gan gymheiriaid

4. Cyhoeddwyd

   RNA-viromics reveals diverse communities of soil RNA viruses with the potential to affect grassland ecosystems across multiple trophic levels

   Hillary, L. S., Adriaenssens, E. M., Jones, D. L. & McDonald, J. E., 8 Ebr 2022, Yn: ISME Communications. 2, 1, t. 34 34.

   Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

5. Cyhoeddwyd

   Effekt von Prozessvariablen bei Holzmodifikation mit PF-Harz

   Kupfernagel, C., Spear, M., Pitman, A. & Ormondroyd, G., 7 Ebr 2022. 2 t.

   Allbwn ymchwil: Cyfraniad at gynhadledd › Papur

6. Cyhoeddwyd

   When One Health Meets the United Nations Ocean Decade: Global Agendas as a Pathway to Promote Collaborative Interdisciplinary Research on Human-Nature Relationships

   Masterson Algar, P., Jenkins, S., Windle, G., Morris-Webb, E., Takahashi, C. K., Burke, T., Rosa, I., Martinez, A. S., Torres-Mattos, E. B., Taddei, R., Morrison, V., Kasten, P., Bryning, L., Cruz de Oliveira, N. R., Gonçalves, L. R., Skov, M., Beynon-Davies, C., Bumbeer, J., Saldiva, P. H. N., Leão, E. & Christofoletti, R., 6 Ebr 2022, Yn: Frontiers in Psychology. 13, 809009.

   Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

7. Cyhoeddwyd

   An iron-reduction-mediated cascade mechanism increases the risk of carbon loss from mineral-rich peatlands

   Qin, L., Freeman, C., Zou, Y., Wang, G., Fenner, N., Yang, L., Otte, M. L. & Jiang, M., 1 Ebr 2022, Yn: Applied Soil Ecology. 172, 104361.

   Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

8. Cyhoeddwyd

   Analytical strategies in venomics.

   Slaagboom, J., Kaal, C., Arrahman, A., Vonk, F. J., Somsen, G. W., Calvete, J. J., Wüster, W. & Kool, J., 1 Ebr 2022, Yn: Microchemical Journal. 175, 22 t., 107187.

   Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

9. Cyhoeddwyd

   Multimodal correlative imaging and modelling of phosphorus uptake from soil by hyphae of mycorrhizal fungi

   Keyes, S., van Veelen, A., Fletcher, D. M., Scotson, C., Koebernick, N., Petroselli, C., Williams, K., Ruiz, S., Cooper, L., Mayon, R., Duncan, S., Dumont, M., Jakobsen, I., Oldroyd, G., Tkacz, A., Poole, P., Mosselmans, F., Borca, C., Huthwelker, T., Jones, D. L. & Roose, T., 1 Ebr 2022, Yn: New Phytologist. 234, 2, t. 688-703 16 t.

   Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

10. Cyhoeddwyd

    Packaging choice and coordinated distribution logistics to reduce the environmental footprint of small-scale beer value chains

    Morgan, D., Styles, D. & Lane, E., 1 Ebr 2022, Yn: Journal of Environmental Management. 307, 114591.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

11. Cyhoeddwyd

    Strategies to reach zero carbon beef and sheep production on Welsh farms

    McNicol, L., Williams, P., Styles, D., Rees, R. M. & Chadwick, D., 1 Ebr 2022, Animal - science proceedings. 1 gol. Cyfrol 13. t. 8-9

    Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Cyfraniad i Gynhadledd

12. Cyhoeddwyd

    A comprehensive framework for assessing the accuracy and uncertainty of global above-ground biomass maps

    Araza, A., de Bruin, S., Herold, M., Quegan, S., Labriere, N., Veiga, P. R., Avitabile, V., Santoro, M., Mitchard, E. T. A., Ryan, C. M., Phillips, O. L., Willcock, S., Verbeeck, H., Carreiras, J., Hein, L., Schelhaas, M-J., Pascagaza, A. M. P., da Concecao Bispo, P., Laurin, G. V., Vieilledent, G., Slik, F., Wijaya, A., Lewis, S. L., Morel, A., Liang, J., Sukhdeo, H., Schepaschenko, D., Cavlovic, J., Gilani, H. & Lucas, R., Ebr 2022, Yn: Remote Sensing of the Environment. 272, 44 t., 112917.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

13. Cyhoeddwyd

    Novel genetic sex markers reveal unexpected lack of, and similar susceptibility to, sex reversal in free-living common toads in both natural and anthropogenic habitats

    Nemesházi, E., Sramkó, G., Laczkó, L., Balogh, E., Szatmári, L., Vili, N., Ujhegyi, N., Üveges, B. & Bókony, V., Ebr 2022, Yn: Molecular Ecology. 31, 7, t. 2032-2043 12 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

14. Cyhoeddwyd

    Oca2 targeting using CRISPR/Cas9 in the Malawi cichlid Astatotilapia calliptera

    Clark, B., Elkin, J., Marconi, A., Turner, G. F., Smith, A. M., Joyce, D., Miska, E. A., Juntti, S. A. & Santos, M. E., Ebr 2022, Yn: Royal Society Open Science. 9, 4, 220077.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

15. Cyhoeddwyd

    Regulation of posterior Hox genes by sex steroids explains vertebral variation in inbred mouse strains

    Mulley, J., Ebr 2022, Yn: Journal of Anatomy. 240, 4, t. 735-745 11 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl adolygu › adolygiad gan gymheiriaid

16. Cyhoeddwyd

    Non-invasive genetic studies and virus epidemiology

    Everest, D. J., Dastjerdi, A., Davies, H., Shuttleworth, C., Ogden, R., Butler, H. & Sapsford, B., 30 Maw 2022, Yn: Veterinary Record. 190, t. 204-205

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl

17. Cyhoeddwyd

    Bangor University's response to the forestry skills shortage

    Healey, J. & Walmsley, J., 25 Maw 2022, Trees, 2022, Spring, t. 28-29 2 t.

    Allbwn ymchwil: Cyfraniad at gyhoeddiad arbenigol › Erthygl

18. Cyhoeddwyd

    Kinetics of microplastic generation from different types of mulch films in agricultural soil

    Yang, Y., Li, Z., Yan, C., Chadwick, D., Jones, D. L., Liu, E., Liu, Q., Bai, R. & He, W., 25 Maw 2022, Yn: Science of the Total Environment. 814

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

19. Cyhoeddwyd

    Using DNA Metabarcoding to Identify Floral Visitation by Pollinators

    Lowe, A., Jones, L., Witter, L., Creer, S. & de Vere, N., 24 Maw 2022, Yn: Diversity. 14, 4

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl adolygu › adolygiad gan gymheiriaid

20. Cyhoeddwyd

    Testing sewage has helped track COVID – soon it could reveal much more about the UK’s health

    Jones, D. L. & Singer, A. C., 23 Maw 2022, The Conversation.

    Allbwn ymchwil: Cyfraniad at gyhoeddiad arbenigol › Erthygl

21. Cyhoeddwyd

    Functional responses of mangrove fauna to forest degradation

    Barbanera, A., Markesteijn, L., Kairo, J., Juma, G. A., Karythis, S. & Skov, M., 17 Maw 2022, Yn: Marine and Freshwater Research.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

22. Cyhoeddwyd

    How do King Cobras move across a major highway? Unintentional wildlife crossing structures may facilitate movement

    Jones, M. D., Marshall, B. M., Smith, S. N., Crane, M., Silva, I., Artchawakom, T., Suwanwaree, P., Waengsothorn, S., Wüster, W., Goode, M. & Strine, C. T., 17 Maw 2022, Yn: Ecology and Evolution. 12, 3, 15 t., e8691.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

23. Cyhoeddwyd

    Managing human-mediated range shifts: understanding spatial, temporal and genetic variation in marine non-native species

    Holman, L. E., Parker-Nance, S., de Bruyn, M., Creer, S., Carvalho, G. & Rius, M., 14 Maw 2022, Yn: Philosophical Transactions of The Royal Society B: Biological Sciences. 377, 1846, 20210025.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

24. Cyhoeddwyd

    Dependence of rainfall-runoff model transferability on climate conditions in Iran

    Jahanshahi, A., Ghazanchaei, Z., Navari, M., Goharian, E., Patil, S. & Zhang, Y., 12 Maw 2022, Yn: Hydrological Sciences Journal. 67, 4, t. 564-587 24 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

25. Cyhoeddwyd

    Is the Amazon rainforest on the verge of collapse?

    Willcock, S., Dearing, J. & Cooper, G., 7 Maw 2022, The Conversation.

    Allbwn ymchwil: Cyfraniad at gyhoeddiad arbenigol › Erthygl

26. Cyhoeddwyd

    Addition of iron to agricultural topsoil and subsoil is not an effective C sequestration strategy

    Button, E. S., Chadwick, D. R. & Jones, D. L., 1 Maw 2022, Yn: Geoderma. 409, 115646.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

27. Cyhoeddwyd

    Circular use of feed by-products from alcohol production mitigates water scarcity

    Schestak, I., Styles, D., Black, K. & Williams, P., 1 Maw 2022, Yn: Sustainable Production and Consumption. 30, t. 158-170

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

28. Cyhoeddwyd

    Climate mitigation efficacy of anaerobic digestion in a decarbonising economy

    Styles, D., Yesufu, J., Bowman, M., Williams, P., Duffy, C. & Luyckx, K., 1 Maw 2022, Yn: Journal of Cleaner Production. 338, 13 t., 130441.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

29. Cyhoeddwyd

    Paddy soils have a much higher microbial biomass content than upland soils: A review of the origin, mechanisms, and drivers

    Wei, L., Ge, T., Zhu, Z., Ye, R., Penuelas, J., Li, Y., Lynn, T. M., Jones, D. L., Wu, J. & Kuzyakov, Y., 1 Maw 2022, Yn: Agriculture, Ecosystems and Environment. 326

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl adolygu › adolygiad gan gymheiriaid

30. Cyhoeddwyd

    The effect of organic manure or green manure incorporation with reductions in chemical fertilizer on yield-scaled N2O emissions in a citrus orchard

    Zhou, W., Ma, Q., Wu, L., Hu, R., Jones, D. L., Chadwick, D. R., Jiang, Y., Wu, Y., Xia, X., Yang, L. & Chen, Y., 1 Maw 2022, Yn: Agriculture, Ecosystems and Environment. 326, 107806.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

31. Cyhoeddwyd

    The environmental release and ecosystem risks of illicit drugs during Glastonbury Festival.

    Aberg, D., Chaplin, D., Freeman, C., Paizs, B. & Dunn, C., 1 Maw 2022, Yn: Environmental Research. 204, Part B, 112061.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

32. Cyhoeddwyd

    Like a bat out of hell: Bats roosting in pit-latrine cesspits

    Dorward, L., Stein, A. & Searle, C., Maw 2022, Yn: African Journal of Ecology. 60, 1, t. 91-94 4 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

33. Cyhoeddwyd

    Looking ahead to the future of GeogEd: Creating spaces of exchange between communities of practice.

    Finn, M., Hammond, L., Healy, G., Todd, J., Marvell, A., McKendrick, J. & Yorke, L., Maw 2022, Yn: Area. 54, 1, t. 41-51 11 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

34. Cyhoeddwyd

    The implications of vehicle collisions for the Endangered endemic Zanzibar red colobus Piliocolobus kirkii

    Olgun, H., Mohammed, M. K., Mzee, A. J., Green, M. E. L., Davenport, T. R. B. & Georgiev, A. V., Maw 2022, Yn: Oryx. 56, 2, t. 268-276 9 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

35. Cyhoeddwyd

    A paper microfluidic device based colorimetric sensor for the detection and discrimination of elapid versus viper envenomation

    Ramana, L., Mathapati, S. S., Salvi, N., Khadilkar, M. V., Malhotra, A., Santra, V. & Sharma, T. K., 21 Chwef 2022, Yn: Analyst. 147, 4, t. 685-694

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

36. Cyhoeddwyd

    A comparison of precipitation and filtration-based SARS-CoV-2 recovery methods and the influence of temperature, turbidity, and surfactant load in urban wastewater

    Kevill, J. L., Pellett, C., Farkas, K., Brown, M. R., Bassano, I., Denise, H., McDonald, J. E., Malham, S. K., Porter, J., Warren, J., Evens, N. P., Paterson, S., Singer, A. C. & Jones, D. L., 20 Chwef 2022, Yn: Science of the Total Environment. 808, 151916.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

37. Cyhoeddwyd

    Early trauma affects an elephant’s ability to assess threat from lions – new research

    Shannon, G., 18 Chwef 2022, The Conversation.

    Allbwn ymchwil: Cyfraniad at gyhoeddiad arbenigol › Erthygl

38. Cyhoeddwyd

    Social Disruption Impairs Predatory Threat Assessment in African Elephants

    Shannon, G., Cordes, L., Slotow, R., Moss, C. & McComb, K., 17 Chwef 2022, Yn: Animals. 12, 4

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

39. Cyhoeddwyd

    Synthesis of (+)-(R)-Tiruchanduramine

    Al-Taie, Z. S., Bartholomew, B., Cartmell, C., Froom, R., Kerr, R. G., Kraehenbuehl, R., Murphy, P., Nash, R. J., Penkova, Y. B. & van Teijlingen, A., 16 Chwef 2022, Yn: Molecules. 27, 4

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

40. Cyhoeddwyd

    A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits

    Stoddart, J., Almeida, D., Silva, C. A., Gorgens, E. B., Keller, M. & Valbuena, R., 15 Chwef 2022, Yn: Remote Sensing. 14, 4

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

41. Cyhoeddwyd

    Understanding and managing uncertainty and variability for wastewater monitoring beyond the pandemic: Lessons learned from the United Kingdom national COVID-19 surveillance programmes

    Wade, M. J., Lo Jacomo, A., Armenise, E., Brown, M. R., Bunce, J. T., Cameron, G. J., Fang, Z., Farkas, K., Gilpin, D. F., Graham, D. W., Grimsley, J. M. S., Hart, A., Hoffmann, T., Jackson, K. J., Jones, D. L., Lilley, C. J., McGrath, J. W., McKinley, J. M., McSparron, C., Nejad, B. F., Morvan, M., Quintela-Baluja, M., Roberts, A. M. I., Singer, A. C., Souque, C., Speight, V. L., Sweetapple, C., Walker, D., Watts, G., Weightman, A. & Kasprzyk-Hordern, B., 15 Chwef 2022, Yn: Journal of Hazardous Materials. 424, Pt B, 127456.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

42. Cyhoeddwyd

    Whole genome resequencing data enables a targeted SNP panel for conservation and aquaculture of Oreochromis cichlid fishes

    Ciezarek, A., Ford, A. G. P., Etherington, G. J., Kasozi, N., Malinsky, M., Mehta, T. K., Penso-Dolfin, L., Ngatunga, B. P., Shechonge, A., Tamatamah, R., Haerty, W., Palma, F. D., Genner, M. J. & Turner, G. F., 15 Chwef 2022, Yn: Aquaculture. 548, Part 2, t. 737637 737637.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

43. Cyhoeddwyd

    Ancient human genomes and environmental DNA from the cement attaching 2,000 year old head lice nits

    Pedersen, M. W., Antunes, C., Cahsan, B. D., Moreno-Mayer, J. V., Sikora, M., Vinner, L., Mann, D., Klimov, P., Black, S., Michieli, C. T., Braig, H. R. & Perotti, M. A., 3 Chwef 2022, Yn: Molecular Biology and Evolution. 39, 2

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

44. Cyhoeddwyd

    Calm and Frenzy: marine obligate hydrocarbonoclastic bacteria sustain ocean wellness

    Yakimov, M. M., Bargiela, R. & Golyshin, P., 2 Chwef 2022, Yn: Current Opinion in Biotechnology. 73, t. 337-345

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

45. Cyhoeddwyd

    Combining targeted grass traits with red clover improves grassland performance and reduces need for nitrogen fertilisation

    Carswell, A., Rafael Sanchez-Rodriguez, A., Saunders, K., le Cocq, K., Shaw, R., Cotton, J., Zhang, Y., Evans, J., Chadwick, D. R., Jones, D. L. & Misselbrook, T., 1 Chwef 2022, Yn: European Journal of Agronomy. 133, 126433.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

46. Cyhoeddwyd

    Establishment of local wastewater-based surveillance programmes in response to the spread and infection of COVID-19-case studies from South Africa, the Netherlands, Turkey and England

    Tlhagale, M., Liphadzi, S., Bhagwan, J., Naidoo, V., Jonas, K., van Vuuren, L., Medema, G., Andrews, L., Been, F., Ferreira, M. L., Saatci, A. M., Kocamemi, B. A., Hassard, F., Singer, A. C., Bunce, J. T., Grimsley, J. M. S., Brown, M. & Jones, D. L., 1 Chwef 2022, Yn: Journal of Water and Health. 20, 2, t. 287-299

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

47. Cyhoeddwyd

    Field application of pure polyethylene microplastic has no significant short-term effect on soil biological quality and function

    Brown, R., Chadwick, D., Thornton, H., Marshall, M., Bei, S., Distaso, M., Bargiela, R., Marsden, K., Clode, P., Murphy, D., Pagella, S. & Jones, D. L., 1 Chwef 2022, Yn: Soil Biology and Biochemistry. 165, 108496.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

48. Cyhoeddwyd

    Predicting leaf traits of temperate broadleaf deciduous trees from hyperspectral reflectance: can a general model be applied across a growing season?

    Chen, L., Zhang, Y., Nunes, M. H., Stoddart, J., Khoury, S., Chan, A. H. Y. & Coomes, D. A., 1 Chwef 2022, Yn: Remote Sensing of Environment. 112767.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

49. Cyhoeddwyd

    Connections among Puget Sound Residents’ Psychological Restoration from Natural Environments, Place Attachment, and Beliefs about Environmental Governance

    Fleming, W., Needham, M. & Biedenweg, K., Chwef 2022, Yn: Environmental Management. 69, t. 258-270

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

50. Cyhoeddwyd

    Reducing Uncertainty in Ecosystem Service Modelling through Weighted Ensembles

    Hooftman, D., Bullock, J., Jones, L., Eigenbrod, F., Barredo, J., Forrest, M., Kinderman, G., Thomas, A. & Willcock, S., Chwef 2022, Yn: Ecosystem Services. 53, 22 t., 101398.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid

51. Cyhoeddwyd

    The role of wind in controlling the connectivity of blue mussels (Mytilus edulis L.) populations

    Demmer, J., Robins, P., Malham, S., Lewis, M., Owen, A., Jones, T. & Neill, S., 21 Ion 2022, Yn: Movement Ecology. 10, 1, 3.

    Allbwn ymchwil: Cyfraniad at gyfnodolyn › Erthygl › adolygiad gan gymheiriaid