Contact

• workRoom BA15 B
  Malaysia Campus
  Jalan Broga
  43500 Semenyih
  Selangor Darul Ehsan
  Malaysia
• work+6 (03) 8924 8733
• Christopher.Gibbins@nottingham.edu.my

Biography

Chris moved to Nottingham Malaysia in January 2017 to take up the post as Head of the newly formed School of Environmental and Geographical Sciences. Prior to this he was a Senior Lecturer at the 188体育网址_188体育在线-【唯一授权网站】@ of Aberdeen (Scotland), working within the Northern Rivers Institute. He was based in Aberdeen for 17 years, following his PhD (1993-1996) and Post-doctoral research (1996-1998) working on environmental flow projects on rivers in Northern England.

C

Expertise Summary

River ecology; human impacts on river ecosystems; environmental flows; river restoration science

Teaching Summary

My specialist teaching covers freshwater ecology, hydrology and sustainable catchment management. Introductory level teaching includes biogeography, hydrology and data analysis.I convene the Ecology… read more

188体育网址_188体育在线-【唯一授权网站】@ Summary

I am a hydro-ecologist with research focussed on understanding the links between physical habitat conditions and biota in freshwater ecosystems. Applied aspects of my research include assessment of… read more

Recent Publications

• MARTEAU, BAPTISTE, BATALLA, RAMON J, VERICAT, DAMI'A and GIBBINS, CHRIS, 2018. Asynchronicity of fine sediment supply and its effects on transport and storage in a regulated river 2614-2633
• B'EJAR, M, VERICAT, D, BATALLA, R J and GIBBINS, C N, 2018. Geomorphology Variation in fl ow and suspended sediment transport in a montane river affected by hydropeaking and instream mining Geomorphology. 310, 69-83
• BIGGS, H.J., NIKORA, V.I., GIBBINS, C.N., CAMERON, S.M., PAPADOPOULOS, K., FRASER, S., STEWART, M., VETTORI, D., SAVIO, M., GREEN, D.R., and HICKS, D.M., 2018. Characterisation of aquatic vegetation: from the statistics of macrophyte patch sizes to highly-resolved flow structure. Proceedings of the 12th International Symposium on Ecohydraulics, Tokyo, Japan.
• MARTEAU, B., GIBBINS, C.N., BATALLA, R.J. and VERICAT, D., 2018. Good practice in managing riverbank instability and erosion.

• View all publications

My specialist teaching covers freshwater ecology, hydrology and sustainable catchment management. Introductory level teaching includes biogeography, hydrology and data analysis.I convene the Ecology of Natural and Managed Ecosystems module, and the Glacial Environments field course. I am an Honorary Professor at 188体育网址_188体育在线-【唯一授权网站】@ of Aberdeen (Scotland) and a 188体育网址_188体育在线-【唯一授权网站】@ing Professor at 188体育网址_188体育在线-【唯一授权网站】@ of Lleida (Spain).

Current 188体育网址_188体育在线-【唯一授权网站】@

I am a hydro-ecologist with research focussed on understanding the links between physical habitat conditions and biota in freshwater ecosystems. Applied aspects of my research include assessment of human impacts on aquatic organisms and the sustainable management of rivers and their catchments. Specific areas of interest are: (i) interactions between river flow hydraulics, sediments and biota (chiefly invertebrates and fish), (ii) impacts of flow and thermal habitat modification on river ecosystems, and (iii) sustainable river management, including the development of ecologically acceptable flow regimes and river restoration. My teaching covers freshwater ecology, biogeography and sustainable catchment and water resources management. I am an Honorary Professor at 188体育网址_188体育在线-【唯一授权网站】@ of Aberdeen (Scotland) and a 188体育网址_188体育在线-【唯一授权网站】@ing Professor at 188体育网址_188体育在线-【唯一授权网站】@ of Lleida (Spain).

Current major funded research projects

1. Hydrogeomorphic status of the Baleh River, Sarawak. This project has recently been awarded and represents a baseline assessment, against which future changes in the river following completion of a major dam can be compared. It focuses on understanding the river's flow regime, coarse and fine sediment dynamics, and the dynamics of hydraulic habitat. The project is funded by Sarawak Energy.

2. Sustainable management of the River Trusan catchment. This project is funded by WWF and aims to help resolve river erosion and flooding issues in a remote catchment in Sarawak, Borneo.

3. Impacts of thermal mismatches on invertebrate fitness across life-stages. This project is funded by grants from NERC (CASE), The Royal Society (UK) and UNMC. It focusses on how dams impact river thermal regimes and how such thermal modification affects insect populations. It is the first project of its type to link across life stages and use genetic and population modelling approaches to understand how the thermal regimes experienced by larvae influence their fitness (fecundity and dispersal ability) once they become adults. In collaboration with Lesley Lancaster, Zoology, Aberdeen.

4. River Ehen (NW England) Restoration Initiative. This ongoing collaboration has funded 2 PhD students to-date, and a new 188体育网址_188体育在线-【唯一授权网站】@ Assistant started on the project in September 2017 to continue the work until 2022. The restoration involves the reconnection of a formerly diverted tributary, with the aim of re-naturalising flow regimes and fluvial dynamics and so improving habitat in the river for the endangered freshwater pearl mussel Margaritifera margaritifera. Funded by Environment Agency and United Utilities.

5. Morphpeak. This 3 year project was awarded funds by the Spanish Ministry of Science in September 2016. It aims to understand the impacts of hydropeaking flow regimes on the fluvial dynamics and ecology of Mediterranean rivers. PI is Dr Damia Vericat of the 188体育网址_188体育在线-【唯一授权网站】@ of Lleida; I am a co-investigator and lead supervise one of the two PhD students working on the project.

Recent projects indicative of my research

1. HYTECH. This Marie Curie Training Network grant funds two Aberdeen-based PhD students who worked jointly between myself and Prof. Vladimir Nikora in the School of Engineering, 188体育网址_188体育在线-【唯一授权网站】@ of Aberdeen. These two students were working on flow-biota interactions and form part of the network that funded 15 PhD students and 2 Post-docs across Europe.

2. Morphsed. This project was based in Spain and aimed to understand the impact of instream gravel mining on fluvial processes and invertebrate communities. It was led by 188体育网址_188体育在线-【唯一授权网站】@ of Lleida and funded by the Spanish Ministry of Science. I was a co-investigator, and lead supervised one of the three PhD students working on the project. See www.morphsed.es for details.

3. BIOMA (Biology of intermittent streams on Mallorca). This project was based on Mallorca (led by Dr Celso Garcia) and aimed to understand how water abstraction impacts the hydrology and ecology of the island's temporary stream ecosystems. The project was funded by the Government of the Balearic Islands and employed a 188体育网址_188体育在线-【唯一授权网站】@ Assistant based on Mallorca; it was in collaboration with 188体育网址_188体育在线-【唯一授权网站】@ of the Balearic Islands, the 188体育网址_188体育在线-【唯一授权网站】@ of Lleida and 188体育网址_188体育在线-【唯一授权网站】@ of Vigo.

Other previous research projects have been funded by a variety of agencies, including the EU, Royal Society, Marine Scotland Science, Leverhulme Trust, Scottish Environment Protection Agency and English Nature, along with various water companies and Scottish Fishery Boards. My main current international collaboration is with the 188体育网址_188体育在线-【唯一授权网站】@ of Lleida (Spain) where I am a 188体育网址_188体育在线-【唯一授权网站】@ing Professor.

• MARTEAU, BAPTISTE, BATALLA, RAMON J, VERICAT, DAMI'A and GIBBINS, CHRIS, 2018. Asynchronicity of fine sediment supply and its effects on transport and storage in a regulated river 2614-2633
• B'EJAR, M, VERICAT, D, BATALLA, R J and GIBBINS, C N, 2018. Geomorphology Variation in fl ow and suspended sediment transport in a montane river affected by hydropeaking and instream mining Geomorphology. 310, 69-83
• BIGGS, H.J., NIKORA, V.I., GIBBINS, C.N., CAMERON, S.M., PAPADOPOULOS, K., FRASER, S., STEWART, M., VETTORI, D., SAVIO, M., GREEN, D.R., and HICKS, D.M., 2018. Characterisation of aquatic vegetation: from the statistics of macrophyte patch sizes to highly-resolved flow structure. Proceedings of the 12th International Symposium on Ecohydraulics, Tokyo, Japan.
• MARTEAU, B., GIBBINS, C.N., BATALLA, R.J. and VERICAT, D., 2018. Good practice in managing riverbank instability and erosion.
• MARTEAU, B., GIBBINS, C.N., BATALLA, R.J. and VERICAT, D., 2018. Hydrological and Geomorphological analysis of the Upper Trusan River to assess remediation for riverbank integrity
• MARTEAU, B., GIBBINS, C.N., BATALLA, R.J. and VERICAT, D., 2018. Geomorphological evolution and ecological response of the River Ehen to the reconnection of a headwater tributary.
• MARTEAU, B, BATALLA, R.J., VERICAT, D. and GIBBINS, C.N., 2017. The importance of a small ephemeral tributary for fine sediment dynamics in a main ‐ stem river 1564-1574
• GIBBINS, C N, VERICAT, D and BATALLA, R J, 2017. Effects of suspended sediment transport on invertebrate drift 1666(March), 1655-1666
• MARTEAU, BAPTISTE, GIBBINS, CHRIS, BATALLA, RAMON J and GREEN, DAVID R, 2017. Application of Structure-from-Motion photogrammetry to river restoration 515(December 2016), 503-515
• GARCIA, CELSO, GIBBINS, CHRISTOPHER N, PARDO, ISABEL and BATALLA, RAMON J, 2017. Science of the Total Environment Long term fl ow change threatens invertebrate diversity in temporary streams : Evidence from an island Science of the Total Environment. 580, 1453-1459
• MARTEAU, B., GIBBINS, C.N., VERICAT, D., BATALLA, R.J. and GREEN, D., 2017. Photogrammetry aids river restoration Geomatics World. 25(3), 14-17
• BUENDIA, CRISTINA, VERICAT, DAMI'A, BATALLA, RAMON J and GIBBINS, CHRIS N, 2016. IN-CHANNEL STORAGE IN A HIGHLY ERODIBLE CATCHMENT 1063(March 2015), 1045-1063
• GIBBINS, C.N., GRANT, J., MALCOLM, I.A. and SOULSBY, C., 2016. Influence of groundwater chemistry on hyporheic invertebrate assemblages is revealed by fine-scale sampling Fundamental and Applied Limnology / Archiv f??r Hydrobiologie. 187(3), 207-221
• GIBBINS, C.N., VERICAT, D., BATALLA, R.J. and BUENDIA, C., 2016. Which variables should be used to link invertebrate drift to river hydraulic conditions? Fundamental and Applied Limnology / Archiv f??r Hydrobiologie. 187(3), 191-205
• PAPADOPOULOS, K., NIKORA, V., CAMERON, S., STEWART, M., BIGGS, H. and GIBBINS, C., 2016. Time-averaged hydrodynamic equations for mobile-bed conditions GeoPlanet: Earth and Planetary Sciences. none, 1-9
• MILLIDINE, K.J., MALCOLM, I.A., MCCARTNEY, A., LAUGHTON, R., GIBBINS, C.N. and FRYER, R.J., 2015. The influence of wind farm development on the hydrochemistry and ecology of an upland stream Environmental Monitoring and Assessment. 187(8),
• QUINLAN, E., GIBBINS, C.N., BATALLA, R.J. and VERICAT, D., 2015. Impacts of Small?Scale Flow Regulation on Sediment Dynamics in an Ecologically Important Upland River Environmental Management. 55(3), 671-686
• GIBBINS, C., 2015. Coupling biological and physical processes: The ecological significance of river channel hydraulics and fluvial dynamics GeoPlanet: Earth and Planetary Sciences. 479-496
• QUINLAN, E., GIBBINS, C., MALCOLM, I., BATALLA, R., VERICAT, D. and HASTIE, L., 2015. A review of the physical habitat requirements and research priorities needed to underpin conservation of the endangered freshwater pearl mussel Margaritifera margaritifera Aquatic Conservation: Marine and Freshwater Ecosystems. 25(1), 107-124
• QUINLAN, E., MALCOLM, I.A. and GIBBINS, C.N., 2014. Spatio-temporal variability of dissolved oxygen within the shallow subsurface zone of a freshwater pearl mussel bed Fundamental and Applied Limnology. 185(3-4), 281-294
• MALCOLM, I.A., GIBBINS, C.N., FRYER, R.J., KEAY, J., TETZLAFF, D. and SOULSBY, C., 2014. The influence of forestry on acidification and recovery: Insights from long-term hydrochemical and invertebrate data Ecological Indicators. 37(PART B), 317-329
• BUENDIA, C., GIBBINS, C.N., VERICAT, D. and BATALLA, R.J., 2014. Effects of flow and fine sediment dynamics on the turnover of stream invertebrate assemblages Ecohydrology. 7(4), 1105-1123
• BUENDIA, C., GIBBINS, C.N., VERICAT, D. and BATALLA, R.J., 2013. Reach and catchment-scale influences on invertebrate assemblages in a river with naturally high fine sediment loads Limnologica. 43(5), 362-370
• IMHOLT, C., SOULSBY, C., MALCOLM, I.A. and GIBBINS, C.N., 2013. Influence of contrasting riparian forest cover on stream temperature dynamics in salmonid spawning and nursery streams Ecohydrology. 6(3), 380-392
• IMHOLT, C., SOULSBY, C., MALCOLM, I.A., HRACHOWITZ, M., GIBBINS, C.N., LANGAN, S. and TETZLAFF, D., 2013. Influence of scale on thermal characteristics in a large montane river basin River 188体育网址_188体育在线-【唯一授权网站】@ and Applications. 29(4), 403-419
• BUENDIA, C., GIBBINS, C.N., VERICAT, D., BATALLA, R.J. and DOUGLAS, A., 2013. Detecting the structural and functional impacts of fine sediment on stream invertebrates Ecological Indicators. 25, 184-196
• MALCOLM, I.A., GIBBINS, C.N., SOULSBY, C., TETZLAFF, D. and MOIR, H.J., 2012. The influence of hydrology and hydraulics on salmonids between spawning and emergence: Implications for the management of flows in regulated rivers Fisheries Management and Ecology. 19(6), 464-474
• MILLIDINE, K.J., MALCOLM, I.A., GIBBINS, C.N., FRYER, R.J. and YOUNGSON, A.F., 2012. The influence of canalisation on juvenile salmonid habitat Ecological Indicators. 23, 262-273
• SOULSBY, C., GRANT, J., GIBBINS, C. and MALCOLM, I.A., 2012. Spatial and temporal variability of Atlantic salmon (Salmo salar L.) spawning activity in braided river channels: A preliminary assessment Aquatic Sciences. 74(3), 571-586
• SMITH, M., VERICAT, D. and GIBBINS, C., 2012. Through-water terrestrial laser scanning of gravel beds at the patch scale Earth Surface Processes and Landforms. 37(4), 411-421
• BUENDIA, C., GIBBINS, C.N., VERICAT, D., LOPEZ-TARAZON, J.A. and BATALLA, R.J., 2011. Influence of Naturally High Fine Sediment Loads on Aquatic Insect Larvae in a Montane River Scottish Geographical Journal. 127(4), 315-334
• WHEATON, J.M., GIBBINS, C., WAINWRIGHT, J., LARSEN, L. and MCELROY, B., 2011. Preface: Multiscale Feedbacks in Ecogeomorphology Geomorphology. 126(3-4), 265-268
• IMHOLT, C., MALCOLM, I.A., BACON, P.J., GIBBINS, C.N., SOULSBY, C., MILES, M. and FRYER, R.J., 2011. Does diurnal temperature variability affect growth in juvenile Atlantic salmon Salmo salar? Journal of Fish Biology. 78(2), 436-448
• IMHOLT, C., GIBBINS, C.N., MALCOLM, I.A., LANGAN, S. and SOULSBY, C., 2010. Influence of riparian cover on stream temperatures and the growth of the mayfly Baetis rhodani in an upland stream Aquatic Ecology. 44(4), 669-678
• GIBBINS, C.N., VERICAT, D. and BATALLA, R.J., 2010. Relations between invertebrate drift and flow velocity in sand-bed and riffle habitats and the limits imposed by substrate stability and benthic density Journal of the North American Benthological Society. 29(3), 945-958
• GIBBINS, CHRIS, BATALLA, RAMON J. and VERICAT, DAMI?, 2010. Invertebrate drift and benthic exhaustion during disturbance: Response of mayflies (Ephemeroptera) to increasing shear stress and river‐bed instability River 188体育网址_188体育在线-【唯一授权网站】@ and Applications. 26(4), 499-511
• GIBBINS, C.N., VERICAT, D. and BATALLA, R.J., 2010. Invertebrate drift-velocity relations and the limits imposed by substrate stability and benthic density. Journal of the North American Benthological Society. 29(3), 945-958
• MOIR, H.J., GIBBINS, C.N., BUFFINGTON, J.M., WEBB, J.H., SOULSBY, C. and BREWER, M.J., 2009. A new method to identify the fluvial regimes used by spawning salmonids Canadian Journal of Fisheries and Aquatic Sciences. 66(9), 1404-1408
• VERICAT, D., BATALLA, R.J. and GIBBINS, C.N., 2008. Sediment entrainment and depletion from patches of fine material in a gravel-bed river Water Resources 188体育网址_188体育在线-【唯一授权网站】@. 44(11),
• TETZLAFF, D., GIBBINS, C., BACON, P.J., YOUNGSON, A.F. and SOULSBY, C., 2008. Influence of hydrological regimes on the pre-spawning entry of Atlantic Salmon (Salmo Salar L.) into an upland river River 188体育网址_188体育在线-【唯一授权网站】@ and Applications. 24(5), 528-542
• VERICAT, D., BATALLA, R. and GIBBINS, C.N., 2008. Initiation of sediment movement in areas of fine material: measurements and experiments. Revista C&G.. 22, 51-62
• GIBBINS, C., VERICAT, D. and BATALLA, R.J., 2007. When is stream invertebrate drift catastrophic? The role of hydraulics and sediment transport in initiating drift during flood events Freshwater Biology. 52(12), 2369-2384
• JACKSON, H.M., GIBBINS, C.N. and SOULSBY, C., 2007. Role of discharge and temperature variation in determining invertebrate community structure in a regulated river River 188体育网址_188体育在线-【唯一授权网站】@ and Applications. 23(6), 651-669
• TETZLAFF, D., SOULSBY, C., BACON, P.J., YOUNGSON, A.F., GIBBINS, C. and MALCOLM, I.A., 2007. Connectivity between landscapes and riverscapes - A unifying theme in integrating hydrology and ecology in catchment science? Hydrological Processes. 21(10), 1385-1389
• GIBBINS, C., VERICAT, D., BATALLA, R.J. and GOMEZ, C.M., 2007. Shaking and moving: Low rates of sediment transport trigger mass drift of stream invertebrates Canadian Journal of Fisheries and Aquatic Sciences. 64(1), 1-5
• VERICAT, DAMI?, BATALLA, RAMON J. and GIBBINS, CHRIS N., 2007. A new tool to study links between sediment transport and invertebrate drift Eos, Transactions American Geophysical Union. 88(41), 410-410
• MOIR, H.J., GIBBINS, C.N., SOULSBY, C. and WEBB, J.H., 2006. Discharge and hydraulic interactions in contrasting channel morphologies and their influence on site utilization by spawning Atlantic salmon (Salmo salar) Canadian Journal of Fisheries and Aquatic Sciences. 63(11), 2567-2585
• TETZLAFF, D., SOULSBY, C., YOUNGSON, A.F., GIBBINS, C., BACON, P.J., MALCOLM, I.A. and LANGAN, S., 2005. Variability in stream discharge and temperature: A preliminary assessment of the implications for juvenile and spawning Atlantic salmon Hydrology and Earth System Sciences. 9(3), 193-208
• MOIR, H.J., GIBBINS, C.N., SOULSBY, C. and YOUNGSON, A.F., 2005. PHABSIM modelling of Atlantic salmon spawning habitat in an upland stream: Testing the influence of habitat suitability indices on model output River 188体育网址_188体育在线-【唯一授权网站】@ and Applications. 21(9), 1021-1034
• TETZLAFF, D., SOULSBY, C., GIBBINS, C., BACON, P.J. and YOUNGSON, A.F., 2005. An approach to assessing hydrological influences on feeding opportunities of juvenile Atlantic salmon (Salmo salar): A case study of two contrasting years in a small, nursery stream Hydrobiologia. 549(1), 65-77
• SOULSBY, C., MALCOLM, I.A., YOUNGSON, A.F., TETZLAFF, D., GIBBINS, C.N. and HANNAH, D.M., 2005. Groundwater-surface water interactions in upland Scottish rivers: Hydrological, hydrochemical and ecological implications Scottish Journal of Geology. 41(1), 39-49
• GIBBINS, C.N., SCOTT, E., SOULSBY, C. and MCEWAN, I., 2005. The relationship between sediment mobilisation and the entry of Baetis mayflies into the water column in a laboratory flume Hydrobiologia. 533(1), 115-122
• MOIR, H.J., GIBBINS, C.N., SOULSBY, C. and WEBB, J., 2004. Linking channel geomorphic characteristics to spatial patterns of spawning activity and discharge use by Atlantic salmon (Salmo salar L.) Geomorphology. 60(1-2), 21-35
• RODGERS, P., SOULSBY, C., PETRY, J., MALCOLM, I., GIBBINS, C. and DUNN, S., 2004. Groundwater-surface-water interactions in a braided river: A tracer-based assessment Hydrological Processes. 18(7), 1315-1332
• GIBBINS, C.N., MOIR, H.J., WEBB, J.H. and SOULSBY, C., 2002. Assessing discharge use by spawning Atlantic salmon: A comparison of discharge electivity indices and PHABSIM simulations River 188体育网址_188体育在线-【唯一授权网站】@ and Applications. 18(4), 383-395
• SOULSBY, C., GIBBINS, C., WADE, A.J., SMART, R. and HELLIWELL, R., 2002. Water quality in the Scottish uplands: A hydrological perspective on catchment hydrochemistry Science of the Total Environment. 294(1-3), 73-94
• MACNEIL, C., DICK, J.T.A., BIGSBY, E., ELWOOD, R.W., IAN MONTGOMERY, W., GIBBINS, C.N. and KELLY, D.W., 2002. The validity of the Gammarus:Asellus ratio as an index of organic pollution: Abiotic and biotic influences Water 188体育网址_188体育在线-【唯一授权网站】@. 36(1), 75-84
• SOULSBY, C., MALCOLM, R., GIBBINS, C. and DILKS, C., 2001. Seasonality, water quality trends and biological responses in four streams in the Cairngorm Mountains, Scotland Hydrology and Earth System Sciences. 5(3), 433-450
• GIBBINS, C.N., DILKS, C.F., MALCOLM, R., SOULSBY, C. and JUGGINS, S., 2001. Invertebrate communities and hydrological variation in Cairngorm mountain streams Hydrobiologia. 462, 205-219
• WEBB, J.H., GIBBINS, C.N., MOIR, H. and SOULSBY, C., 2001. Flow requirements of spawning atlantic salmon in an upland stream: Implications for water-resource management Water and Environment Journal. 15(1), 1-8
• GIBBINS, C.N., SOULSBY, C., JEFFRIES, M.J. and ACORNLEY, R., 2001. 188体育网址_188体育在线-【唯一授权网站】@ ecologically acceptable river flow a regimes: A case study of Kielder water transfer system Fisheries Management and Ecology. 8(6), 463-485
• GIBBINS, C.N. and ACORNLEY, R.M., 2000. Salmonid habitat modelling studies and their contribution to the development of an ecologically acceptable release policy for Kielder Reservoir, North-east England Regulated Rivers: 188体育网址_188体育在线-【唯一授权网站】@ and Management. 16(3), 203-224
• GIBBINS, C.N., JEFFRIES, M.J. and SOULSBY, C., 2000. Impacts of an inter-basin water transfer: Distribution and abundance of Micronecta poweri (Insecta: Corixidae) in the River Wear, north-east England Aquatic Conservation: Marine and Freshwater Ecosystems. 10(2), 103-115
• SOULSBY, C., GIBBINS, C.N. and ROBINS, T., 1999. The use of inter-basin water transfers as a flexible water resource during drought: the Kielder scheme in North-east England. Journal of the Chartered Institute of Water and Environmental Management. 13, 213-223
• GIBBINS, C.N. and HESLOP, J., 1998. An evaluation of inter-basin water transfers as a mechanism for augmenting salmonid and grayling habitat in the River Wear, North-East England Regulated Rivers: 188体育网址_188体育在线-【唯一授权网站】@ and Management. 14(4), 357-382
• GIBBINS, C.N. and MOXON, J., 1998. Calopteryx splendens (Insecta: Odonata) at edge-of-range sites in North-east England. J. Brit. Drag. Soc.. 14, 33-45