Ysgol Gwyddorau Amgylcheddol a Naturiol
- Pennod › Ymchwil › Heb ei adolygu gan gymheiriaid
- Cyhoeddwyd
Role of pure and mixed cultures of gram-positive eubacteria in mineral leaching.
Johnson, D. B., Bacelar-Nicolau, P., Okibe, N., Yahya, A., Hallberg, K. B., Ciminelli, V. S. (Golygydd) & Garcia Jr, O. (Golygydd), 1 Ion 2001, Biohydrometallurgy: Fundamentals: Technology and Sustainable Development. 2001 gol. Elsevier, t. 461-470Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Root production and turnover in Populus grown under elevated CO2 using a Free Air Enrichment system POPFACE
Lukac, M., Calfapietra, C., Godbold, D. L., Horst, W. W. (Golygydd), Sattelmacher, B. (Golygydd), Schmidhalter, U. (Golygydd), Schubert, S. (Golygydd), Von Wiren, N. (Golygydd), Wittenmayer, L. (Golygydd), Schenk, M. K. (Golygydd), Burkert, A. (Golygydd), Claassen, N. (Golygydd) & Flessa, H. (Golygydd), 1 Ion 2001, Plant nutrition - food security and sustainability of agro-ecosystems through applied and basic research.. 2001 gol. Kluwer Academic Publishers, t. 688-689Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Saltation, Emergence and Non-Linear Dynamics
Winder, N. & Winder, I., 2016, Non-Linearities and System Flips : COMPLEX Final Scientific Report . Winder, N. & Liljenstrom, H. (gol.). Sigtuna: Sigtuna Foundation Press, Cyfrol 2. t. 16-29Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Sclerocarya birrea (A.Rich.) Hochst.
Hall, J. B., Oyen, L. P. (Golygydd) & Lemmens, R. H. (Golygydd), 1 Ion 2002, Precursor. PROTA Programme: Wageningen.. 2002 gol. Plant Resources of Tropical Africa, t. 127-131Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Separating the tree-soil-crop interactions in agroforestry parkland systems in sapone (Burkina faso) using WaNuLCAS.
Bayala, J., Van Noordwijk, M., Lusiana, B., Ni'matul, K., Teklehaimanot, Z., Ouedraogo, S. J., Jose, S. (Golygydd) & Gordon, A. M. (Golygydd), 1 Ion 2008, Toward Agroforestry Design: An Ecological Approach. 2008 gol. Springer, t. 285-300Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Shotgun Metagenomic Sequencing Analysis of Soft-Rot Enterobacteriaceae in Polymicrobial Communities
Doonan, J., Denman, S., McDonald, J. & Golyshin, P., 30 Tach 2016, Metagenomics. Streit , W. R. & Daniel, R. (gol.). Springer New York, Cyfrol 1539. t. 85-97 (Methods in Molecular Biology; Cyfrol 1539).Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Silvopasture
Pagella, T. & Whistance, L., 5 Gorff 2019, The Agroforestry Handbook: Agroforestry for the UK. Raskin, B. & Osborn, S. (gol.). 1 gol. Bristol, UK: Soil Association Limited, t. 45-59 15 t.Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Snakes of Papua New Guinea.
Wuster, W., Williams, D., Wüster, W., Jensen, S. (Golygydd), Nimorakiotakis, B. (Golygydd) & Winkel, K. D. (Golygydd), 1 Ion 2005, Venomous bites and stings in Papua New Guinea: A guide to treatment for health workers and doctors. 2005 gol. Parkville, Vic. : Australian Venom Research Unit, t. 33-64Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Social organization and information transfer in schooling fish.
Couzin, I. D., James, R., Croft, D. P., Brown, C. (Golygydd), Laland, K. N. (Golygydd) & Krause, J. (Golygydd), 1 Ion 2006, Fish Cognition and Behaviour. 2006 gol. Blackwell, t. 166-182Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Soil erosion.
McDonald, M. A., Lawrence, A., Shrestha, P. K., Schroth, G. (Golygydd) & Sinclair, F. L., 1 Ion 2003, Trees: crops and soil fertility: concepts and research methods. 2003 gol. CAB International, t. 325-343Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Soil functioning in natural and planted woodlands on slate waste
Williamson, J. C., Jones, D. L., Rowe, E. C., Healey, J. R., Bardgett, R., Hobbs, P., Moore, H. M. (Golygydd), Fox, H. R. (Golygydd) & Elliott, S. (Golygydd), 1 Ion 2003, Land Reclamation: Extending the Boundaries. 2003 gol. Taylor & Francis, t. 315-318Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Soil functioning in natural and planted woodlands on slate waste
Williamson, J. C., Jones, D. L., Rowe, E. C., Healey, J. R., Bardgett, R., Hobbs, P., Moore, H. M. (Golygydd), Fox, H. R. (Golygydd) & Elliott, S. (Golygydd), 1 Ion 2003, Land reclamation. 2003 gol. Swets & Zeitlinger, t. 315-318Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Soziale Netzwerke bei Tieren.
Krause, J., James, R., Croft, D. P. & Naguib, M. (Golygydd), 1 Ion 2006, Methoden der Verhaltensbiologie. 2006 gol. Springer Verlag, t. 148-152Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Stereoselective Reduction Using Sodium Triacetoxyborodeuteride: Synthesis of Methyl 2,3-Di-O-benzyl-α-d-(4-2H)-glucopyranoside
Mobarak, H., Engstrom, O., Lahmann, M., Widmalm, G., Roy, R. (Golygydd) & Vidal, S. (Golygydd), 27 Mai 2015, Carbohydrate Chemistry: Proven Synthetic Methods: Volume 3. 2015 gol. CRC Press, t. 81-88Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Studies on the relaxation of heat-treated wood.
Gonzalez-Pena, M., Breese, M. C., Hale, M. D., Militz, H. (Golygydd) & Hill, C. A. (Golygydd), 1 Ion 2005, Wood modification: processes: properties and commercialisation.. 2005 gol. Gottingen, t. 87-90Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Studying magnesium transport across and via mycorrhiza of Norway spruce roots.
Kuhn, A. J., Jentschke, G., Stettien, A., Brande, B., Godbold, D. L., Schroder, W. H., Horst, W. W. (Golygydd), Sattelmacher, B. (Golygydd), Schmidhalter, U. (Golygydd), Schubert, S. (Golygydd), Von Wiren, N. (Golygydd), Wittenmayer, L. (Golygydd), Schenk, M. K. (Golygydd), Burkert, A. (Golygydd), Claassen, N. (Golygydd) & Flessa, H. (Golygydd), 1 Ion 2001, Plant nutrition - food security and sustainability of agro-ecosystems through applied and basic research.. 2001 gol. Kluwer Academic Publishers, t. 642-643Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Substantive element "Economic aspects of forests", including "Trade"
Price, C., Ramersteiner, E., Guldin, R., Buck, A. (Golygydd), Parrotta, J. (Golygydd) & Wolfrum, G. (Golygydd), 1 Ion 2003, Science and technology - building the future of the world's forests: planted forests and biodiversity. 2003 gol. IUFRO Occasional Paper 15, t. 5-8Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Symbiotic Rickettsia.
Braig, H. R., Turner, B. D., Perotti, M. A., Bourtzis, K. (Golygydd) & Miller, T. A. (Golygydd), 1 Ion 2008, Insect Symbiosis 3. 2008 gol. Taylor and Francis, t. 221-252Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Synthesis and Lewis acidity of B-O-Si and B-O-Sn derivatives.
Beckett, M. A., Owen, P., Varma, K. S., Davidson, M. G. (Golygydd), Hughes, A. K. (Golygydd), Marder, T. B. (Golygydd) & Wade, K. (Golygydd), 1 Ion 2000, Contemporary Boron Chemistry. 2000 gol. Royal Society of Chemistry, t. 100-103Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Taking local knowledge about trees seriously.
Sinclair, F. L., Joshi, L. & Lawrence, A. (Golygydd), 1 Ion 2001, Forestry: forest users and research: new ways of learning. 2001 gol. ETFRN, t. 45-61Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Techniques for detecting and identifying acidophilic mineral-oxidising microorganisms.
Johnson, D. B., Hallberg, K. B., Rawlings, D. E. (Golygydd) & Johnson, D. B. (Golygydd), 1 Ion 2007, Biomining. 2007 gol. Springer Verlag, t. 237-262Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Techniques for detecting and identifying acidophilic mineral-oxidizing microorganisms
Johnson, D. B., Hallberg, K. B. & Rawlings, D. E. (Golygydd), 1 Ion 2006, Biomining. 2006 gol. Springer Verlag, t. 237-261Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Terrestrial Invertebrate Animal Metagenomics, Lumbricidae
Nechitaylo, T. Y., Ferrer, M., Golyshin, P. N. & Nelson, K. E. (Golygydd), 18 Chwef 2015, Encyclopedia of Metagenomics. 2015 gol. Springer, t. 1-10Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The COMPLEX Approach to Innovation Management
Winder, N. & Winder, I., 2016, The Quest for a Model-Stakeholder Fusion: COMPLEX Final Scientific Report . Winder, N., Liljenstrom, H. & Seaton, R. (gol.). Sigtuna: Sigtuna Foundation Press, Cyfrol 1. t. 211-219 (Human Nature Series).Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The Description of Work (DOW) as a Model
Winder, N. & Winder, I., 2016, The Quest for a Model-Stakeholder Fusion: COMPLEX Final Scientific Report. Winder, N., Liljenstrom, H. & Seaton, R. (gol.). Sigtuna: Sigtuna Foundation Press, Cyfrol 1. t. 189-199 (Human Nature Series).Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The Mekong River basin: comprehensive water governance.
Gajaseni, N., Heal, O. W., Edwards-Jones, G., Finger, M. (Golygydd), Tamiotti, L. (Golygydd) & Allouche, J. (Golygydd), 1 Ion 2001, The multi-governance of water through four case studies. 2001 gol. SUNY Press, t. 43-78Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The Microbiology of Extremely Acidic Environment
Johnson, D. B. & Aguilera, A., Mai 2016, Manual of Environmental Microbiology. Yates, M. V., Nakatsu, C. H., Miller, R. V. & Pillai, S. D. (gol.). 4th gol.Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The authenticity of Basmati rice-a case study
Woolfe, M. & Steele, K., 11 Medi 2019, DNA Techniques to Verify Food Authenticity: Applications in Food Fraud (Food Chemistry, Function and Analysis) . Burns, M., Foster, L. & Walker, M. (gol.). Royal Society of ChemistryAllbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The control of carbon acquisition by and growth of roots.
Farrar, J. F., Jones, D. L., De Kroon, H. (Golygydd) & Visser, E. J. (Golygydd), 1 Ion 2003, Root Ecology. 2003 gol. Springer-Verlag Berlin and Heidelberg GmbH, t. 91-124Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The development of reintroduction biology in New Zealand and Australia
Armstrong, D. P., Moro, D., Hayward, M. W., Seddon, P. J. & Hayward, M. W. (Golygydd), 6 Tach 2015, Advances in Reintroduction Biology of Australian and New Zealand Fauna. 2015 gol. CSIRO PublishingAllbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The economics of transformation from even-aged to uneven-aged forestry.
Price, C., Helles, F. (Golygydd), Strange, N. (Golygydd) & Wichmann, L. (Golygydd), 1 Ion 2003, Recent accomplishments in applied forest economics research. 2003 gol. Kluwer Academic Publishers, t. 3-17Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The effects of pesticides on soil microflora.
Jones, S. E., Johnson, D. B., Young, J. E. (Golygydd), Griffin, M. N. (Golygydd), Alford, D. V. (Golygydd) & Oglivy, S. E. (Golygydd), 1 Ion 2002, Reducing Agrochemical Use on the Arable Farm: The Talisman and Scarab Projects.. 2002 gol. Department for Environment, Food & Rural Affairs, t. 255-276Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The effects of temperature on ectotherm protein metabolism.
Whiteley, N. M., Fraser, K. P., Esterhouse, T. E. (Golygydd) & Petrinos, L. B. (Golygydd), 1 Ion 2009, Protein Biosynthesis. 2009 gol. Nova Science PublishersAllbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The effects of variation in management objectives on responses to invading diseases under uncertainty: Forest Pathogens
Dangerfield, C., Whalley, E., Hanley, N., Healey, J. & Gilligan, C., 18 Ebr 2018, 92nd Annual Conference, Agricultural Economics Society, Warwick University, Coventry, UK, 16-18 April, 2018. 40 t.Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The geochemistry of acid mine drainage
Blowes, D. W., Ptacek, C. J., Jamboor, J. L., Weisner, C. G., Paktunc, D., Gould, W. D. & Johnson, D., 8 Tach 2013, Treatise on Geochemistry . Holland, H. D. & Turekian, K. K. (gol.). 2nd gol. Elsevier Science, Cyfrol 11. t. 131-190Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The history and future of agroforestry research and development: policy impacts and needs.
Beer, J., Ibrahim, M., Sinclair, F. L., Mery, G. (Golygydd), Alfaro, R. (Golygydd), Kanninen, M. (Golygydd) & Lobovikov, M. (Golygydd), 1 Ion 2005, Forests in the global balance: changing paradigms. 2005 gol. IUFRO, t. 151-160Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The impact of private sanctuary networks on reintroduction programmes
Innes, J., Burns, B., Sanders, A., Hayward, M. W., Armstrong, D. P. (Golygydd), Moro, D. (Golygydd) & Hayward, M. W. (Golygydd), 6 Tach 2015, Advances in Reintroduction Biology of Australian and New Zealand Fauna. 2015 gol. CSIRO PublishingAllbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The influence of elevated atmospheric CO2 on mycorrhizal colonisation and species assemblage of trees
Godbold, D. L., Lukac, M. & Radoglou, K. (Golygydd), 1 Ion 2001, Forest research: a challenge for an integrated approach.. 2001 gol. NAGEF, t. 191-194Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The influence of soil acidity and free air carbon dioxide enrichment (POPFACE) on root production and turnover in trees
Jentschke, G. W., Lukac, M., Van Dam, D., Fritz, H. W., Jentschke, G., Calfapietra, C., Godbold, D. L. & Radoglou, K. (Golygydd), 1 Ion 2001, Forest research: a challenge for an integrated approach.. 2001 gol. NAGEF, t. 194-200Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The landscape of sustainable economics.
Price, C., Benson, J. F. (Golygydd) & Roe, M. (Golygydd), 1 Ion 2007, Landscape and sustainability. 2007 gol. Routledge, t. 37-57Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The management of coastal sand dune woodland for red squirrels (Sciurus vulgaris L.)
Shuttleworth, C. & Gurnell, J., 2001, Coastal Dune Management: Shared Experience of European Conservation Practice. Houston, J., Edmondson, A. S. E. & Rooney, P. J. (gol.). Liverpool University Press, t. 117-127Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The role of indigenous fruit trees in sustainable dryland agriculture in Eastern Africa.
Teklehaimanot, Z., Akinnifesi, F. K. (Golygydd), Leakey, R. R. (Golygydd) & Ajayi, O. (Golygydd), 1 Ion 2008, Indigenous Fruit Trees in the Tropics: Domestication: Utilization and Commercialization.. 2008 gol. CABI, t. 204-219Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The role of ligands in mediating charge transport in nanocrystalline medium
Baxter, S. & Thomas, P. J., 8 Awst 2017, Nanoscience. Thomas, P. J. & Revaprasadu, N. (gol.). Royal Society of Chemistry, Cyfrol 4. t. 169-184 15 t. (Specialist Periodical Report).Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The role of predator exclosures in conservation
Hayward, M. W., Moseby, K., Read, J. & Glen, A. D. (Golygydd), 22 Ion 2015, Carnivores of Australia - Past: Present and Future.Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The spread of genetic constructs in natural insect populations.
Braig, H. R., Yan, G., Letourneau, D. K. (Golygydd) & Burrows, B. E. (Golygydd), 1 Ion 2002, Genetically Engineered Organisms: Assessing Environmental and Human Health Effects. 2002 gol. CRC Press, t. 251-314Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
The transfer of natural resource management rights to local communities
Pollini, J., Hockley, N., Muttenzer, F. D., Ramamonjisoa, B. S. & Scales, I. R. (Golygydd), 6 Maw 2014, Conservation and Environmental Management in Madagascar. 2014 gol. Routledge, t. 172-192Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Thiophene-based materials for elctroluminescent applications.
Perepichka, I. F., Perepichka, D. F., Meng, H. & Perepichka, I. F. (Golygydd), 1 Ion 2009, Handbook of Thiophene-Based Materials: Applications in Organic Electronics and Photonics. Volume 2: Properties and Applications.. 2009 gol. John Wiley and Sons, t. 695-756Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Using the DOW for Decision-Support
Winder, N. & Winder, I., 2016, The Quest for a Model-Stakeholder Fusion COMPLEX Final Scientific Report Vol 1: COMPLEX Final Scientific Report. Winder, N., Liljenstrom, H. & Seaton, R. (gol.). Sigtuna: Sigtuna Foundation Press, Cyfrol 1. t. 200-210 (Human Nature Series).Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Valuing biodiversity: a western perspective.
Price, C., Nagy, L. (Golygydd), Maraiastuti, A. (Golygydd), Proctor, J. (Golygydd), Bruenig, E. F. (Golygydd) & Miller, H. G. (Golygydd), 1 Ion 2002, Curriculum: sustainable forest management and conservation of biodiversity in Indonesia. 2002 gol. University of Stirling, t. 61-77Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod
- Cyhoeddwyd
Variation in sea trout (Salmo trutta) abundance and life histories in the Irish Sea
Milner, N., Potter, E., Roche, W., Tysklind, N., Davidson, I., King, J., Coyne, J. & Davies, C., Tach 2017, Sea Trout: Science and Management: Proceedings of the 2nd International Sea Trout Symposium. Harris, G. (gol.). Kibworth Beauchamp: Matador, t. 96-128 32 t. 5Allbwn ymchwil: Pennod mewn Llyfr/Adroddiad/Trafodion Cynhadledd › Pennod