Southern Hemisphere meteor rates Final report

Diurnal variations of Southern Hemisphere meteor rat

The implications of a changing climate on agricultural land classification in England and Wales

The agricultural land classification (ALC) of England and Wales is a formal method of assessing the quality of agricultural land and guiding future land use. It assesses several soil, site and climate criteria and classifies land according to whichever is the most limiting. A common approach is required for calculating the necessary agroclimatic parameters over time in order to determine the effects of changes in the climate on land grading. In the present paper, climatic parameters required by the ALC classification have been re-calculated from a range of primary climate data, available from the Meteorological Office's UKCP09 historical dataset, provided as 5 km rasters for every month from 1914 to 2000. Thirty-year averages of the various agroclimatic properties were created for 1921–50, 1931–60, 1941–70, 1951–80, 1961–90 and 1971–2000. Soil records from the National Soil Inventory on a 5 km grid across England and Wales were used to determine the required soil and site parameters for determining ALC grade. Over the 80-year period it was shown that the overall climate was coolest during 1951–80. However, the area of land estimated in retrospect as ‘best and most versatile (BMV) land’ (Grades 1, 2 and 3a) probably peaked in the 1951–80 period as the cooler climate resulted in fewer droughty soils, more than offsetting the land which was downgraded by the climate being too cold. Overall there has been little change in the proportions of ALC grades among the six periods once all 10 factors (climate, gradient, flooding, texture, depth, stoniness, chemical, soil wetness, droughtiness and erosion) are taken into account. This is because it is rare for changes in climate variables all to point in the same direction in terms of ALC. Thus, a reduction in rainfall could result in higher grades in wetter areas but lead to lower classification in drier areas

Symmetry-breaking and chaos in electron transport in semiconductor superlattices

We study the motion of electrons in a single miniband of a semiconductor superlattice driven by THz electric field polarized along the growth direction. We work in the semiclassical balance-equation model, including different elastic and inelastic scattering rates, and incorporating the self-consistent electric field generated by electron motion. We explore regions of complex dynamics, which can include chaotic behaviour and symmetry-breaking. We estimate the magnitudes of dc current and dc voltage that spontaneously appear in regions of broken-symmetry for parameters characteristic of modern semiconductor superlattices. This work complements PRL 80(1998)2669 [ cond-mat/9709026 ].Comment: 4 pages, 3 figures, RevTEX, EPS

Supression of magnetic subbands in semiconductor superlattices driven by a laser field

The effect of strong laser radiation on magnetic subbands in semiconductor superlattices is investigated. Due to the presence of a magnetic field perpendicular to the growth direction, non-linear effects such as band supression and electron localization become relevant at relatively lower intensities and for any polarization perpendicular to the magnetic field. Electron quasienergies and density of states are calculated in the Kramers-Henneberger approximation, whose validity is discussed. The conditions under which collapse of magnetic subbands and quenching of N-photon emission or absorption processes occur are discussed. We conclude that at laser frequencies close to cyclotronic frequency and intensities typical of c.w. lasers, magnetic subbands become flat, magnetotunneling is inhibited and multiphotonic processes dominate optical absorption.Comment: 4 pages RevTex, 2 figure

Evaluating Gismondi's Representation of Portus, the Port of Imperial Rome

[EN] This paper introduces the Portus Project, an inter-disciplinary collaborative fieldwork project focussed on the ancient port of Rome. It demonstrates the use that is being made of a plaster model of the port produced by Italo Gismondi in 1937, initially as a means for focussing re-evaluations of the various illustrative and other data available relating to the port’s topography, and then as a source for background and comparative digital geometric data within the project’s work to remodel the entire site. The Portus Project employs three-dimensional computer graphics throughout the data gathering, analysis, modelling and representation phases and the paper considers the role that Gismondi’s model is playing in the development and evaluation of such a process.The Portus Project is directed by Simon Keay, and funded by the UK Arts and Humanities Research Council, the Soprintendenza per i Beni Archeologici di Ostia Antica, the University of Southampton, the British School at Rome and the University of Cambridge. It involves many partners including the British School at Rome, the Universities of Southampton, Cambridge, Oxford, Warwick, Bath, Aixen-Provence and Seville, the Institut Català d’Arqueología Clàssica, Parsifal Cooperativa Di Archeologia (Rome) and L-P Archaeology. The project is grateful to the Duke Sforza Cesarini for continued access to his land. Access to Gismondi’s model was provided by the Sorprintendenza per I Beni Archaeologici di Ostia Antica.Earl, GP.; Keay, SJ.; Beale, GC. (2010). Evaluating Gismondi's Representation of Portus, the Port of Imperial Rome. Virtual Archaeology Review. 1(1):21-25. https://doi.org/10.4995/var.2010.4752OJS212511FORTE M., PESCARIN S., PIETRONI E. (2005) "The Appia Antica Project", in Forte, M., Williams, P.R. (eds) The Reconstruction of Archaeological Landscapes through Digital Technologies, Atti del II Convegno Italia-USA. British Archaeological Reports. International Series 1379, 2005: pp. 79-95FRISCHER, B. Rome Reborn http://www.romereborn.virginia.edu/ [Consult: 1-04-2009].FRISCHER, B. (2008) "The Rome Reborn Project. How Technology is helping us to study history,", in OpEd, November 10, 2008. University of Virginia.GAIANI, M., BALZANI, M. AND UCCELLI, F. (2000) "Reshaping the Coliseum in Rome: An Integrated Data Capture and Modeling Method at Heritage Sites", in Gross, M. and Hopgood, F.R.A. (eds.) Proceedings of Eurographics 2000: European Association. for Computer Graphics, Interlaken, Switzerland, 2000 pp. 369-78 http://dx.doi.org/10.1111/1467-8659.00429GUIDI, G., B. FRISCHER, ET AL. (2005) "Virtualizing Ancient Rome: 3D Acquisition and Modeling of a Large Plaster-of-Paris Model of Imperial Rome,", in Beraldin, J.-A., El-Hakim, S.F., Gruen, A., Walton, J.S. (eds) Videometrics VIII 18-20 January 2005, San Jose, California, USA, SPIE, vol. 5665, pp. 119-133. http://dx.doi.org/10.1117/12.587355GUILLEMAIN, J. (2002) "Pierre-Joseph Garrez (1802-1852), porto di Traiano a Ostia, 1834", in Italia antiqua. Envois degli architetti franesi (1811-1950) - Italia e area mediterranea pp. 393-8. Paris, École Nationale Supérieure des Beaux Arts.HAPPA, J., WILLIAMS, M., TURLEY, G., EARL, G., DUBLA, P., BEALE, G., GIBBONS, G., DEBATTISTA, K. AND CHALMERS, A. (2009) "Virtual Relighting of a Roman Statue Head from Herculaneum, A Case Study", in Hardy, A., Marais, P., Spencer, SN., Gain, JE., Straßer, W. (eds): Proceedings of the 6th International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa, Afrigraph 2009, Pretoria, South Africa, February 4-6, 2009. ACM 2009 pp 5-12HASELBERGER, L & HUMPHREY, J H. (2006) Imaging Ancient Rome: Documentation - Visualization - Imagination. Proceedings of the Third Williams Symposium on Classical Architecture. Journal of Roman Archaeology Supplement 61. JRA, Portsmouth R.I.KEAY, S., (2006). "Portus", in Current World Archaeology 20: 11-20KEAY, S., EARL, G., HAY, S., KAY, S., OGDEN, J., & STRUTT, K. (2008) "The Potential of Archaeological Geophysics. The Work of the British School at Rome in Italy", in Geofisica per l'archeologia: Possibilita e Limiti. Roma 10 Dicembre 2008. pp. 25-44. Rome, CISTEC.KEAY, S., MILLETT, M., PAROLI, L., STRUTT, K. (2005). Portus: An Archaeological Survey of the Imperial Port of Rome. Archaeological Monographs of the British School at Rome 15. London.LUGLI, G. & FILIBECK, G. (1935) Il Porto di RomaiImperiale e l'agro portuense. Bergamo, Officine dell'Istituto Italiano d'Arti Grafiche.MALAFARINA, G. (2005) La Galleria delle carte geografiche. The Gallery of Maps in the Vatican. Modena, Franco Cosimi Panini.MALZBENDER, T., GELB, D., WOLTERS, H . (2001) Polynomial Texture Mapping www.hpl.hp.com/personal/Tom_Malzbender/papers/PTM.pdf [Consult: 1-04-2009]POLLARD, J. & GILLINGS, M. (1998) "Romancing the Stones: towards a virtual and elemental Avebury", in Archaeological Dialogues 5:2, pp. 143-164 http://dx.doi.org/10.1017/S1380203800001276REDDÉ, M. & GOLVIN, J-C. (2008) I Romani e il Mediterraneo. Rome, Istituto e Zecca dello Stato. Libreria dello Stato.RICKMAN, G. (1971) Roman Granaries and Store Buildings. Cambridge.TESTAGUZZA, O. (1970) Portus: illustrazione dei Porti di Claudio e Traiano e della cittá di Porto a Fiumicino. Rome, Julia Editrice.VERDUCHI, P. (2007) "Porto", in Filippi, F. (ed.) Ricostruire l'Antico prima del virtuale. Italo Gismondi. Un architetto per l'archeologia (1887- 1974). pp. 245-52. Rome, Edizioni Quasar.VERDUCHI, P. (1999) "Il porto di Traiano, dépliant, Roma". Model available from: http://www2.rgzm.de/Navis2/Home/HarbourFullTextOutput.cfm?HarbourNR=Ostia-Traiano [Consult: 1-04- 2009]

APF, HB-EGF, and EGF biomarkers in patients with ulcerative vs. non-ulcerative interstitial cystitis

BACKGROUND: Interstitial cystitis (IC) is a chronic bladder disorder, with symptoms including pelvic and or perineal pain, urinary frequency, and urgency. The etiology of IC is unknown, but sensitive and specific biomarkers have been described, including antiproliferative factor (APF), heparin-binding epidermal growth factor-like growth factor (HB-EGF), and epidermal growth factor (EGF). However, the relative sensitivity of these biomarkers in ulcerative vs. nonulcerative IC is unknown, and these markers have yet to be validated in another laboratory. We therefore measured these markers in urine from patients with or without Hunner's ulcer, as well as normal controls, patients with bladder cancer, and patients with bacterial cystitis, at the First Hospital of China Medical University. METHODS: Urine specimens were collected from two groups of Chinese IC patients (38 IC patients with Hunner's ulcers, 26 IC patients without Hunner's ulcers), 30 normal controls, 10 bacterial cystitis patients and 10 bladder cancer patients. APF activity was determined by measuring (3)H-thymidine incorporation in vitro, and HB-EGF and EGF levels were determined by ELISA. RESULTS: APF activity (inhibition of thymidine incorporation) was significantly greater in all IC patient urine specimens than in normal control specimens or in specimens from patients with bacterial cystitis or bladder cancer (p < 0.0001 for each comparison). Urine HB-EGF levels were also significantly lower and EGF levels significantly higher in both groups of IC patients than in the three control groups (p < 0.0001 for each comparison). Although APF and HB-EGF levels were similar in ulcerative and nonulcerative IC patients, EGF levels were significantly higher in IC patients with vs. without ulcers (p < 0.004). CONCLUSION: These findings indicate that APF, HB-EGF and EGF are good biomarkers for both ulcerative and nonulcerative IC and validate their measurement as biomarkers for IC in Chinese patients

Spontaneous DC Current Generation in a Resistively Shunted Semiconductor Superlattice Driven by a TeraHertz Field

We study a resistively shunted semiconductor superlattice subject to a high-frequency electric field. Using a balance equation approach that incorporates the influence of the electric circuit, we determine numerically a range of amplitude and frequency of the ac field for which a dc bias and current are generated spontaneously and show that this region is likely accessible to current experiments. Our simulations reveal that the Bloch frequency corresponding to the spontaneous dc bias is approximately an integer multiple of the ac field frequency.Comment: 8 pages, Revtex, 3 Postscript figure