Sensitivity of the mussel Mytilus edulis to substrate‑borne vibration in relation to anthropogenically generated noise

© 2015 Inter-Research. Many anthropogenic activities in the oceans involve direct contact with the seabed (for example pile driving), creating radiating particle motion waves. However, the consequences of these waveforms to marine organisms are largely unknown and there is little information on the ability of invertebrates to detect vibration, or indeed the acoustic component of the signal. We quantified sensitivity of the marine bivalve Mytilus edulis to substrate-borne vibration by exposure to vibration under controlled conditions. Sinusoidal excitation by tonal signals at frequencies within the range 5 to 410 Hz was applied during the tests, using the 'staircase' method of threshold determination. Thresholds were related to mussel size and to seabed vibration data produced by anthropogenic activities. Clear behavioural changes were observed in response to the vibration stimulus. Thresholds ranged from 0.06 to 0.55 m s -2 (acceleration, root mean squared), with valve closure used as the behavioural indicator of reception and response. Thresholds were shown to be within the range of vibrations measured in the vicinity of anthropogenic operations such as pile driving and blasting. The responses show that vibration is likely to impact the overall fitness of both individuals and mussel beds of M. edulis due to disruption of natural valve periodicity, which may have ecosystem and commercial implications. The observed data provide a valuable first step to understanding the impacts of such vibration upon a key coastal and estuarine invertebrate which lives near industrial and construction activity, and illustrate that the role of seabed vibration should not be underestimated when assessing the impacts of noise pollution

New Wrinkles on an Old Model: Correlation Between Liquid Drop Parameters and Curvature Term

The relationship between the volume and surface energy coefficients in the liquid drop A^{-1/3} expansion of nuclear masses is discussed. The volume and surface coefficients in the liquid drop expansion share the same physical origin and their physical connection is used to extend the expansion with a curvature term. A possible generalization of the Wigner term is also suggested. This connection between coefficients is used to fit the experimental nuclear masses. The excellent fit obtained with a smaller number of parameters validates the assumed physical connection.Comment: 6 pages, 2 figure

On the density-potential mapping in time-dependent density functional theory

The key questions of uniqueness and existence in time-dependent density functional theory are usually formulated only for potentials and densities that are analytic in time. Simple examples, standard in quantum mechanics, lead however to non-analyticities. We reformulate these questions in terms of a non-linear Schr\"odinger equation with a potential that depends non-locally on the wavefunction.Comment: 8 pages, 2 figure

Paul F. Grady and the debate on the authority of the APB

Paul F. Grady is recognized in accounting history as a practitioner, a researcher, a scholar, and a public servant, (Previts, September, 1986); indeed, he epitomized the accounting professional. Grady began his professional career in 1923 and served as a partner in Arthur Andersen & Company (1932-1942) and Price Waterhouse & Company (1944-1960). During his career in public accounting, Grady served on many committees of the American Institute of Certified Public Accountants (Institute). He chaired the committee on auditing procedure (1944-1948) which developed and published Generally Accepted Auditing Standards: Their Significance and Scope and Internal Control: Elements of a Co-Ordinated System and Its Importance to Management and the Public Accountant

Paul F. Grady: contributions in the development of accounting principles

Paul Grady\u27s involvement in the development of accounting principles is examined in this paper with emphasis placed on the events during the period of 1955 to 1965 which led to the establishing of the Accounting Principles Board (APB, Board) and the Research Division and the publishing of Accounting Research Study, No. 7, Inventory of Generally Accepted Accounting Principles for Business Enterprises (Inventory, ARS No. 7). This paper is not a study of the contents or a critical evaluation of ARS No. 7 or of The Basic Postulates of Accounting (ARS No. 1) and A Tentative Set of Broad Accounting Principles for Business Enterprises (ARS No. 3)

Development of a radiographic technique for porcine head ballistic research

Introduction: The porcine model shows structural features comparable to that of humans and are routinely used within research, due to the ethical, legal, and practical use of post-mortem human samples. Methods for obtaining high quality and comparable reference data using standardised acquisition protocols are essential. Methods: The decapitated heads of three adult white sows were subjected to radiographic imaging before and after cranial trauma (9 mm, Heckler and Koch MP5). Digital radiographs were generated using a Siemens MULTIX TOP system with an Agfa digital detector, with foam blocks and sandbags as ancillary equipment. An iterative approach was adopted by the authors to generate reproducible radiographic views from two perpendicular angles. Specimens were kept at 5 °C and wrapped in polythene bags to reduce the impact of putrefaction. Results: Standardised head radiography technique was developed for superior-inferior and lateral views demonstrating porcine anatomy. Key parameters included: automatic exposure control for tube current (∼4 mAs), tube voltage of 73 kVp, 100 cm source to image receptor distance, and an anti-scatter grid. Slight variances in specimen morphology, developmental status, and soft tissue changes did not affect imaging outcomes. Conclusion: The technique and positioning proposed in this study allows for the acquisition of high quality and reproducible radiographic images for comparable ballistic research datasets. Specimen positioning and centring of the primary beam may be applied across porcine breeds, although individual radiographic parameters may differ according to equipment specifications and specimen size. Implications for practice: Development of a reproducible radiographic technique of porcine heads in forensic and veterinary research

THE ART ATHLETE: A SPORTS BIOMECHANICS PERSPECTIVE

Overuse injuries are as much a problem for ‘art athletes’ (dancers and musicians and performing artists generally) as they are for those we more commonly term ‘athletes’. Lower back injuries in male ballet dancers are certainly commonplace. 3D motion analysis in combination with 3D Static Strength Predicting analysis showed that compressive forces at L5/S1 were above the National Institute of Occupational Safety and Health ‘Back Compression Design Limit’ (~ 4,500N) and shear forces were high (~ 530 N) for male dancers performing two commonly used classical lifts. A research design for the use of an opto-reflective motion analysis (Vicon) to investigate shoulder joint loading in cellists and violinists will also be presented

Improving Physiological Relevance of Cell Culture: The Possibilities, Considerations and Future Directions of the Ex Vivo Co-Culture Model

In vitro models provide an important platform for the investigation of cellular growth and atrophy to inform, or extend mechanistic insights from, logistically challenging in vivo trials. While these models allow for the identification of candidate mechanistic pathways, many models involve supraphysiological dosages, non-physiological conditions, or experimental changes relating to individual proteins or receptors, all of which limit translation to human trials. To overcome these drawbacks, the use of ex vivo human plasma and serum has been used in cellular models to investigate changes in myotube hypertrophy, cellular protein synthesis, anabolic and catabolic markers in response to differing age, disease states, and nutrient status. However, there are currently no concurrent guidelines outlining the optimal methodology for this model. This review discusses the key methodological considerations surrounding the use of ex vivoplasma and serum, with a focus in application to skeletal muscle cell lines (i.e., C2C12, L6 and LHCN-M2) and human primary skeletal muscle cells (HSMC) as a means to investigate molecular signaling in models of atrophy and hypertrophy, alongside future directions