Alongshore variability in wave energy transfer to coastal cliffs

The alongshore distribution of wave energy is believed to be an important control on the spatial variability of coastal erosion. There is, however, a lack of field data quantifying the alongshore variability in wave energy on rock coasts, whereby the relative control of coastline geometry versus foreshore characteristics on wave energy delivery remains unclear. A number of studies have identified high-frequency cliff-top ground shaking to be generated by wave impacts at the cliff toe during high tides (HT). To capture the variability of wave-cliff impact energy along-coast, we installed an array of cliff-top seismometers along a 1 km stretch of coastline in North Yorkshire, UK. Our aim is to constrain how wave energy transfer to the cliff toe varies, and to examine the relative energy transfer around typical coastline features, including a bay and headlands. Whilst the greatest HT ground motion energy is recorded at a headland and the lowest at the centre of the bay (5% of that observed at the headland), we identify no systematic alongshore variation in the HT ground motion energy that can be related to coastline morphology. We also note considerable variation between features of similar form: the total HT ground motion energy at one headland is only 49% of the next headland 1 km alongshore. Between neighbouring sites within the bay, separated by only 100 m, we observe up to an order of magnitude difference in ground motion energy transfer. Our results demonstrate the importance of the foreshore in driving the variations in energy delivery that we observe. Local alterations in water depth and foreshore topography control the alongshore distribution of wave energy available to generate cliff HT ground motions. Importantly, this apparently local effect overrides the influence of macroscale coastal planform morphology, which has previously been assumed to be the dominant control. The results show that foreshore characteristics that hold influence over wave energy transfer vary significantly over short (~100 m) distances, and so we expect erosion controlled by wave impacts to vary over similar scales

Drift-dependent changes in iceberg size-frequency distributions

Although the size-frequency distributions of icebergs can provide insight into how they disintegrate, our understanding of this process is incomplete. Fundamentally, there is a discrepancy between iceberg power-law size-frequency distributions observed at glacial calving fronts and lognormal size-frequency distributions observed globally within open waters that remains unexplained. Here we use passive seismic monitoring to examine mechanisms of iceberg disintegration as a function of drift. Our results indicate that the shift in the size-frequency distribution of iceberg sizes observed is a product of fracture-driven iceberg disintegration and dimensional reductions through melting. We suggest that changes in the characteristic size-frequency scaling of icebergs can be explained by the emergence of a dominant set of driving processes of iceberg degradation towards the open ocean. Consequently, the size-frequency distribution required to model iceberg distributions accurately must vary according to distance from the calving front

Amyloid deposition in Parkinson's disease and cognitive impairment: A systematic review

BackgroundVarying degrees of cortical amyloid deposition are reported in the setting of Parkinsonism with cognitive impairment. We performed a systematic review to estimate the prevalence of Alzheimer disease (AD) range cortical amyloid deposition among patients with Parkinson's disease with dementia (PDD), Parkinson's disease with mild cognitive impairment (PD‐MCI) and dementia with Lewy bodies (DLB). We included amyloid positron emission tomography (PET) imaging studies using Pittsburgh Compound B (PiB).MethodsWe searched the databases Ovid MEDLINE, PubMed, Embase, Scopus, and Web of Science for articles pertaining to amyloid imaging in Parkinsonism and impaired cognition. We identified 11 articles using PiB imaging to quantify cortical amyloid. We used the metan module in Stata, version 11.0, to calculate point prevalence estimates of patients with “PiB‐positive” studies, that is, patients showing AD range cortical Aβ‐amyloid deposition. Heterogeneity was assessed. A scatterplot was used to assess publication bias.ResultsOverall pooled prevalence of “PiB‐positive” studies across all three entities along the spectrum of Parkinson's disease and impaired cognition (specifically PDD, PD‐MCI, and DLB) was 0.41 (95% confidence interval [CI], 0.24‐0.57). Prevalence of “PiB‐positive” studies was 0.68 (95% CI, 0.55‐0.82) in the DLB group, 0.34 (95% CI, 0.13‐0.56) in the PDD group, and 0.05 (95% CI, −0.07‐0.17) in the PD‐MCI group.ConclusionsSubstantial variability occurs in the prevalence of “PiB‐positive” studies in subjects with Parkinsonism and cognitive impairment. Higher prevalence of PiB‐positive studies was encountered among subjects with DLB as opposed to subjects with PDD. The PD‐MCI subjects showed overall lower prevalence of PiB‐positive studies than reported findings in non–PD‐related MCI. © 2015 International Parkinson and Movement Disorder SocietyPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111915/1/mds26191.pd

The Role of Policy Makers and Institutions in the Energy Sector: The Case of Energy Infrastructure Governance in Nigeria

This paper focuses on investigating the linkages and consequences of the policy decision process in the governance of energy infrastructure in Nigeria. It attempts to gain a better understanding of the role of policy makers and institutions in the provision of energy infrastructure in Nigeria. Using a combination of semi-structured interviews and documentary evidences from published literature, this study reveals three essential areas where the policy-making processes (and therefore policy makers) intervene in the provision of energy infrastructure. These are: (1) granting access to historical data; (2) regulations; and (3) permitting/issuance of licenses. This study also reveals three major unintended consequences of the policy decision processes and institutions in the governance of energy infrastructure provisions in Nigeria, which are: (1) government financing corruption in the energy sector; (2) economic delusion; and (3) uncontrolled growth in energy demand driven more by export and not local internal demand

The Proposed OECD Multilateral Instrument Amending Tax Treaties

In this article, the authors consider some of the practical issues relating to the introduction of the OECD multilateral instrument amending tax treaties, which has been proposed within the context of the OECD/G20 Base Erosion and Profit Shifting Project

Some Reflections on the Proposed Revisions to the OECD Model and Commentaries, and on the Multilateral Instrument, with Respect to Fiscally Transparent Entities

This material was first published by Sweet & Maxwell Limited in Angelo Nikolakakis, Stephane Austry, John Avery Jones, Philip Baker, Peter Blessing, Robert Danon, Shefali Goradia, Johann Hattingh, Koichi Inoue, Juergen Luedicke, Guglielmo Maisto, Toshio Miyatake, Kees van Raad, Richard Vann and Bertil Wiman, “Some Reflections on the Proposed Revisions to the OECD Model and Commentaries, and on the Multilateral Instrument, With Respect to Fiscally Transparent Entities”, British Tax Review, Vol. 2017, No. 3, pp. 295-373, 2017 and is reproduced by agreement with the Publishers. This article sets out some reflections of the authors on those aspects of the OECD’s October 2015 final report on Neutralising the Effects of Hybrid Mismatch Arrangements (the Hybrids Report) that relate to revisions to the OECD Model to add a specific provision on fiscally transparent entities (as a new Article 1(2)), and to build on the Commentaries already in place in this regard (the HR Proposals). It also considers the similar and related provisions contained in the multilateral instrument to implement the tax treaty related BEPS measures (the MLI) that was released on 24 November 2016. The authors conduct an extensive review of the issues and raise a number of interpretive and technical questions, as well as policy considerations. This review is set against the backdrop of an examination of similar provisions (or provisions with similar purposes) in the US Models and in various existing bilateral treaties, as well as under domestic laws, of the countries represented by the authors. The authors also provide some observations with respect to potential scope and drafting or implementation of alternatives, with a view to contributing to the ongoing international debate and reform project

The Medieval Climate Anomaly and Little Ice Age in Chesapeake Bay and the North Atlantic Ocean

This paper is not subject to U.S. copyright. The definitive version was published in Palaeogeography, Palaeoclimatology, Palaeoecology 297 (2010): 299-310, doi:10.1016/j.palaeo.2010.08.009.A new 2400-year paleoclimate reconstruction from Chesapeake Bay (CB) (eastern US) was compared to other paleoclimate records in the North Atlantic region to evaluate climate variability during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Using Mg/Ca ratios from ostracodes and oxygen isotopes from benthic foraminifera as proxies for temperature and precipitation-driven estuarine hydrography, results show that warmest temperatures in CB reached 16–17 °C between 600 and 950 CE (Common Era), centuries before the classic European Medieval Warm Period (950–1100 CE) and peak warming in the Nordic Seas (1000–1400 CE). A series of centennial warm/cool cycles began about 1000 CE with temperature minima of ~ 8 to 9 °C about 1150, 1350, and 1650–1800 CE, and intervening warm periods (14–15 °C) centered at 1200, 1400, 1500 and 1600 CE. Precipitation variability in the eastern US included multiple dry intervals from 600 to 1200 CE, which contrasts with wet medieval conditions in the Caribbean. The eastern US experienced a wet LIA between 1650 and 1800 CE when the Caribbean was relatively dry. Comparison of the CB record with other records shows that the MCA and LIA were characterized by regionally asynchronous warming and complex spatial patterns of precipitation, possibly related to ocean–atmosphere processes

Hippocampal - diencephalic - cingulate networks for memory and emotion: An anatomical guide

This review brings together current knowledge from tract tracing studies to update and reconsider those limbic connections initially highlighted by Papez for their presumed role in emotion. These connections link hippocampal and parahippocampal regions with the mammillary bodies, the anterior thalamic nuclei, and the cingulate gyrus, all structures now strongly implicated in memory functions. An additional goal of this review is to describe the routes taken by the various connections within this network. The original descriptions of these limbic connections saw their interconnecting pathways forming a serial circuit that began and finished in the hippocampal formation. It is now clear that with the exception of the mammillary bodies, these various sites are multiply interconnected with each other, including many reciprocal connections. In addition, these same connections are topographically organised, creating further subsystems. This complex pattern of connectivity helps explain the difficulty of interpreting the functional outcome of damage to any individual site within the network. For these same reasons, Papez’s initial concept of a loop beginning and ending in the hippocampal formation needs to be seen as a much more complex system of hippocampal–diencephalic–cingulate connections. The functions of these multiple interactions might be better viewed as principally providing efferent information from the posterior medial temporal lobe. Both a subcortical diencephalic route (via the fornix) and a cortical cingulate route (via retrosplenial cortex) can be distinguished. These routes provide indirect pathways for hippocampal interactions with prefrontal cortex, with the preponderance of both sets of connections arising from the more posterior hippocampal regions. These multi-stage connections complement the direct hippocampal projections to prefrontal cortex, which principally arise from the anterior hippocampus, thereby creating longitudinal functional differences along the anterior–posterior plane of the hippocampus