Coastal Cities and Environmental Change

This paper explores the complex environmental relationships of coastal cities with their shorelines and the sea. Cities developed in coastal locations because they offered easy access to fisheries, trade and commerce, transport, attractive scenery and recreational opportunities. However, coastal cities have also been vulnerable to the natural hazards of hurricane-force winds, tsunamis and tidal flooding; and climate change will exacerbate flood risks in the future. Many of the world's largest cities are situated by the sea, and today in every continent except North America the highest share of urban dwellers live in coastal zones. These issues, together with growing concerns over the state of the world's oceans - declining fish stocks, aquatic ecosystem degradation, and marine acidification - have attracted growing historical interest in coastal cities and their role in environmental change. Using examples of different types of coastal cities, I survey how growing urbanisation, trade, industrialisation and tourism impacted on shorelines and the sea over time. I also examine how communities have adapted to the challenges and risks of living in coastal cities. The paper concludes by offering some suggestions for further inquiry

Non-dispersive wavepacket solutions of the Schrodinger equation

The free Schrodinger equation has constant velocity wavepacket solutions \psi_{\bf v} of the form \psi= f({\bf r} - {\bf v}t) e^{- i m c^2 t / 2}. These solutions are eigenvectors of a momentum operator {\bf \tilde p} which is symmetric in a positive definite scalar product space. We discuss whether these \psi_{\bf v} can act as basis states rather than the usual plane wave solutions.Comment: 12 pages, parameters amended to yield correct dimension and new section added on relativistic extensio

Coping related variables, cardiac vagal activity and working memory performance under pressure

The aim of this study was to assess the predictive role of coping related variables (trait emotional intelligence and reinvestment, challenge and threat appraisals and cardiac vagal activity) on cardiac vagal activity and working memory under low pressure (LP) and high pressure (HP) conditions. Participants (n = 49) completed trait questionnaires, the Decision Specific Reinvestment Scale, the Movement Specific Reinvestment Scale and Trait Emotional Intelligence Questionnaire. They realized the automated span task, which tests working memory, under counterbalanced LP and HP conditions. Cardiac vagal activity measurements were taken at rest, task and post task for 5 min, along with self-reported ratings of stress. Upon completion of the task, self-report measures of motivation, stress appraisal, attention and perceived pressure were completed. Current findings suggest cardiac vagal activity at rest can predict cardiac vagal activity under pressure, decision reinvestment influences cardiac vagal activity in cognitive tasks under LP and working memory performance is predicted by task cardiac vagal activity in HP only. These results show the importance of combining both subjective and objective psychophysiological variables in performance prediction and strengthen the need for this approach to be adopted across samples

Heralded Generation of Ultrafast Single Photons in Pure Quantum States

We present an experimental demonstration of heralded single photons prepared in pure quantum states from a parametric downconversion source. It is shown that, through controlling the modal structure of the photon pair emission, one can generate pairs in factorable states and thence eliminate the need for spectral filters in multiple-source interference schemes. Indistinguishable heralded photons were generated in two independent spectrally engineered sources, and, by performing a Hong-Ou-Mandel interference between them without spectral filters at a raw visibility of 94.4%, their purity was measured to be over 95%.Comment: 5 pages, 4 figure

Geophysical Characterization of Faults of the Okavango Rift Zone, Northwest Botswana, Africa

To examine the geophysical characteristics of the faults associated with the OkavangoRift Zone (ORZ) in northwest Botswana, electrical resistivity tomography (ERT), magnetotellurics (MT), total field magnetic, and gravity surveys were conducted along selected faults across the rift. MT results show that the Tsau and Lecha faults have propagated into the sedimentary cover and are interpreted to be active conduits for fluid flow from the Okavango Delta despite their lack of surface expression. ERT and MT data show that tectonic activity along the Kunyere Fault has significantly waned and strain is being accommodated by the tectonically active Thamalakane Fault and Mababe Fault. Impermeable fault cores and an abundance of minor faults, fractures, and splays within the damage zones characterize the faults within the ORZ as both barriers and conduits to fluid flow. Ground and aeromagnetic data display some of the faults as magnetic highs while others are depicted as magnetic lows in the basement. The differences in magnetic character may be attributed to the 1.) commingling of fluids and basement rocks of contrasting redox potentials along fault planes or 2.) extreme variation of magnetic susceptibilities of the rocks juxtaposed on either side of the faults. Fluids may also play a role in increasing pore pressure through cracks associated with interconnecting faults and fractures, causing the ORZ to have a lack of severe earthquakes and allowing easier slip to occur between fault planes which may enhance lengthening the widening of the rift.Boone Pickens School of Geolog