Geographical catch distribution of yellowfin and skipjack tuna in the Eastern Pacific Ocean, 1967-1970, and fleet and total catch statistics, 1962-1970

ENGLISH: Logbook records of tuna vessels fishing in the eastern Pacific Ocean were used to prepare charts showing the distribution of yellowfin tuna and skipjack catches by i-degree area, by quarter of the year, and by gear, for the years 1967-1970. Recent changes in the geographical distribution of yellowfin catch are illustrated. Also given are annual catch statistics and the composition of the international tuna fishing fleets which operated in the Commission's Yellowfin Regulatory Area each year, 1962-1970. SPANISH: Los registros de los cuadernos de bitácora de los barcos pesqueros de atún en el Océano Pacífico oriental se usaron para preparar gráficos que presentan para los años de 1967-1970, la distribución de captura del atún aleta amarilla y barrilete por área de 1 grado, trimestre del año y, por las artes. Se ilustran los recientes cambios en la distribución geográfica de la captura del atún aleta amarilla. Se presentan también las estadísticas de captura anual y la composición de la flota internacional de pesca, que explota cada año el Area Reglamentaria de la Comisión, 1962-1970. (PDF contains 95 pages.

Geographical distribution of yellowfin tuna and skipjack catches in the Eastern Pacific Ocean, by quarters of the year, 1963-1966

ENGLISH: Logbook records of tuna vessels fishing in the eastern Pacific Ocean were used to prepare charts showing the distribution of yellowfin and skipjack tuna catches by 1-degree area, by quarter of the year, and by gear for the years 1963-1966. Recent changes in the geographical distribution of yellowfin catches are illustrated. The size composition of the U. S. tuna fleet is given, and recent changes are discussed. SPANISH: Los registros de los cuadernos de bitácora de los barcos atuneros que pescan en el Océano Pacifico oriental, se emplearon para preparar los gráficos que indican la distribuci6n de las capturas de atún aleta amarilla y de barrilete por área de 1 grado, por trimestre del ano y por aparejo de pesca para los anos de 1963-1966. Se ilustran los cambios recientes en la distribucion geográfica de las capturas de atún aleta amarilla. Se da la composición de tamaño de la flota atunera de los E. U. y se discuten los cambios recientes. (PDF contains 76 pages.

The moments of the PDF of concentration for gas clouds in the presence of fences

A team led by D. J. Hall has conducted many trials, each involving the instantaneous release of a heavy or neutrally buoyant gas in the presence of a fence aligned transverse to the mean flow, thus complementing earlier trials without fences. For each fence and for each Richardson Number Ri, at least 50 repetitions of each release were performed. This allowed estimates to be made of some statistical properties (mean concentration m, standard deviation s, skewness S, kurtosis K), and their variation with time. Typical results are presented and discussed. The strongest influence of the fences on the evolution of m and s with time is vertical mixing, but there are also interesting changes with fence height and type, and with Ri. The possibility of a relationship between m and s is discussed. However, the most remarkable result is, perhaps, that the estimates of S and K are such that, in all cases, the (K, S) plot collapses onto a quadratic curve; this extends the same finding earlier by Mole and Clarke for steady releases and, in particular, suggests strongly that the PDF of concentration is, in practice, determined by only three properties

Natural control of the mosquito population via Odonata and Toxorhynchites

The main impact of mosquito pests is the transmission of many dangerous diseases and death. Hence, the reduction of their population by the use of a natural control method is a primary objective of this research. This mosquito reduction method utilises different species of predators (Odonata) and (Toxorhynchites) to substantially improve the environment. The frequency of capturing the pest mosquitoes by the predators is determined using a Pascal distribution, whilst insect mortality is modelled using a Weibull distribution. The results from the model show that by using insect predators, a significant reduction of the mosquito population is possible in less than eighty days

Comparison of spatial domain optimal trade-off maximum average correlation height (OT-MACH) filter with scale invariant feature transform (SIFT) using images with poor contrast and large illumination gradient

A spatial domain optimal trade-off Maximum Average Correlation Height (OT-MACH) filter has been previously developed and shown to have advantages over frequency domain implementations in that it can be made locally adaptive to spatial variations in the input image background clutter and normalised for local intensity changes. In this paper we compare the performance of the spatial domain (SPOT-MACH) filter to the widely applied data driven technique known as the Scale Invariant Feature Transform (SIFT). The SPOT-MACH filter is shown to provide more robust recognition performance than the SIFT technique for demanding images such as scenes in which there are large illumination gradients. The SIFT method depends on reliable local edge-based feature detection over large regions of the image plane which is compromised in some of the demanding images we examined for this work. The disadvantage of the SPOTMACH filter is its numerically intensive nature since it is template based and is implemented in the spatial domain. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Investigation of the collapse of the skewness and kurtosis exhibited in atmospheric dispersion data

This paper studies the collapse of the estimators for skewness and kurtosis of concentration onto a near universal curve. This phenomenon is observed for data taken from atmospheric dispersion experiments under a variety of different conditions. By means of careful investigation of the high concentration tails, modelled by means of the generalized Pareto distribution, and the fundamental physics of the problem, a set of envelope curves encompassing the data will be established. The implications of these results for modelling the probability density function of concentration are discussed

Comments on the properties and uses of atmospheric dispersion datasets

Great recent improvements in the quality and quantity of atmospheric dispersion datasets have highlighted the crucial importance of concentration fluctuations. However, this has inevitably been accompanied by the realisation that estimating the properties of concentration fluctuations accurately involves new, difficult, but interesting, research problems. Some of these problems are discussed and illustrated. The paper concludes with some recommendations about how research funding agencies (such as governments, regulatory authorities and industry) should change their present strategy in response to new knowledge

Electrical properties of breast cancer cells from impedance measurement of cell suspensions

Impedance spectroscopy of biological cells has been used to monitor cell status, e.g. cell proliferation, viability, etc. It is also a fundamental method for the study of the electrical properties of cells which has been utilised for cell identification in investigations of cell behaviour in the presence of an applied electric field, e.g. electroporation. There are two standard methods for impedance measurement on cells. The use of microelectrodes for single cell impedance measurement is one method to realise the measurement, but the variations between individual cells introduce significant measurement errors. Another method to measure electrical properties is by the measurement of cell suspensions, i.e. a group of cells within a culture medium or buffer. This paper presents an investigation of the impedance of normal and cancerous breast cells in suspension using the Maxwell-Wagner mixture theory to analyse the results and extract the electrical parameters of a single cell. The results show that normal and different stages of cancer breast cells can be distinguished by the conductivity presented by each cell. © 2010 IOP Publishing Ltd

Soft Decision Analyzer and Method

A soft decision analyzer system is operable to interconnect soft decision communication equipment and analyze the operation thereof to detect symbol wise alignment between a test data stream and a reference data stream in a variety of operating conditions

Closed-Loop Analysis of Soft Decisions for Serial Links

Modern receivers are providing soft decision symbol synchronization as radio links are challenged to push more data and more overhead through noisier channels, and software-defined radios use error-correction techniques that approach Shannon s theoretical limit of performance. The authors describe the benefit of closed-loop measurements for a receiver when paired with a counterpart transmitter and representative channel conditions. We also describe a real-time Soft Decision Analyzer (SDA) implementation for closed-loop measurements on single- or dual- (orthogonal) channel serial data communication links. The analyzer has been used to identify, quantify, and prioritize contributors to implementation loss in real-time during the development of software defined radios