Functional morphology of cephalopod gills

There is a wealth of literature dealing with fish gills (Review, see Hoar & Randall, 1984), yet hardly anything is known about the gills of cephalopods. This is rather surprising considering the commercial importance of the cephalopods. In view of the paucity of information available it was necessary to start by establishing the morphology of the gills. This is covered in the first section of this thesis. Of all the cephalopods, Octopus vulgaris was singled out for more detailed investigation (see chapters 2 & 3) as its physiology is comparatively well understood (Wells, 1978). The gills of cephalopods are the major sites for respiratory gaseous exchange. It follows that their dimensions might be expected to govern their potential for absorbing oxygen. Section two deals with the morphometries of cephalopod gills, and predicted values are compared with physiological measurements of oxygen uptake for four representative The final section describes the physiological experiments I performed on octopuses. These experiments were designed to find out whether the animals could regulate the gills' potential to take up oxygen through changes to the gills themselves.

Distribution, relative abundance and developmental morphology of paralarval cephalopods in the Western North Atlantic Ocean

Paralarval and juvenile cephalopods collected in plankton samples on 21 western North Atlantic cruises were identified and enumerated. The 3731 specimens were assigned to 44 generic and specific taxa. This paper describes their spatial and temporal distributions and their developmental morphology. The smallest paralarvae recognized for a number of species are identified and illustrated. The two most abundant and most frequently collected taxa were identifiable to species based on known systematic characters of young, as well as on distribution of the adults. These were the neritic squids Loligo pealeii and Illex illecebrosus collected north of Cape Hatteras, both valuable fishery resources. Other abundant taxa included two morphotypes of ommastrephids, at least five species of enoploteuthids, two species of onychoteuthids, and unidentified octopods. Most taxa were distributed widely both in time and in space, although some seasonal and mesoscale-spatial patterns were indicated. The taxa that appeared to have distinct seasonal distribution included most of the neritic species and, surprisingly, the young of the bathypelagic cranchiids. In eight seasonal cruises over the continental shelf of the middle U.S. Atlantic states, neritic taxa demonstrated approximately the same seasonal patterns during two consecutive years. Interannual differences in the oceanic taxa collected on the shelf were extreme. The highest abundance and diversity of planktonic cephalopods in the oceanic samples were consistently found in the vicinity of the Gulf Stream. Only eight of the oceanic taxa appeared to have limited areal distributions, compared with twelve taxa that were found throughout the western North Atlantic regions sampled in this study. Many taxa, however, were not collected frequently enough to describe seasonal or spatial patterns. Comparisons with published accounts of other cephalopod surveys indicate both strengths and weaknesses in various sampling techniques for capturing the young of oceanic cephalopods. Enoploteuthids were abundant both in our study and in other studies using midwater trawls in several areas of the North Atlantic. Thus, this family probably is adequately sampled over its developmental range. In contrast, octopoteuthids and chtenopterygiids are rare in collections made by small to medium-sized midwater trawls but are comparatively common in plankton samples. For families that are relatively common in plankton samples, paralarval abundance, derived similarly to the familiar ichthyoplankton surveys of fisheries science, may be the most reliable method of gathering data on distribution and abundance. (PDF file contains 58 pages.)

Role of G protein coupled inwardly rectifier K+ channels (GIRK) on the neurobiology depression

353 págs.

Effects of a flash-flood on channel morphology and some insects of a small stony stream in the Peak District, Derbyshire

In this paper, some observations are made following a flash-flood that occurred in Stake Clough, a small tributary of the River Goyt, during the evening of 6 August 1996. The site was visited eight times between 8 August - 30 October 1996 to take samples and make observations on the stream. The flood scoured the bed of Stake Clough but more significantly, caused it to change course along the middle part of the floodplain. Initially after the flood, the numbers of insects in all stretches of the stream channel were low (100-200 m super(2)), but then gradually rose to population densities approaching ten times this figure. The benthos was dominated by the Chironomidae and also leuctrid stoneflies (Leuctra nigra, L. hippopus and L. inermis). On 8th August 1996, 12 mesh bags, each containing oak leaves, were placed in the stream and collected after 24 hours. These were also dominated by chironomids, and contained relatively high numbers of the caddis, Potamophylax cingulatus.

Part I. Influence of membrane morphology on ion-exchange and charge propagation in composite polyelectrolyte electrode coatings. Part II. Dynamic surface tension measurements of polarization relaxation at mercury pool electrodes by the method of Wilhelmy.

Part I. Novel composite polyelectrolyte materials were developed that exhibit desirable charge propagation and ion-retention properties. The morphology of electrode coatings cast from these materials was shown to be more important for its electrochemical behavior than its chemical composition.

Part II. The Wilhelmy plate technique for measuring dynamic surface tension was extended to electrified liquid-liquid interphases. The dynamical response of the aqueous NaF-mercury electrified interphase was examined by concomitant measurement of surface tension, current, and applied electrostatic potential. Observations of the surface tension response to linear sweep voltammetry and to step function perturbations in the applied electrostatic potential (e.g., chronotensiometry) provided strong evidence that relaxation processes proceed for time-periods that are at least an order of magnitude longer than the time periods necessary to establish diffusion equilibrium. The dynamical response of the surface tension is analyzed within the context of non-equilibrium thermodynamics and a kinetic model that requires three simultaneous first order processes.

Optical intrinsically fuzzy mathematical morphology for gray-scale image processing

Intrinsically fuzzy morphological erosion and dilation are extended to a total of eight operations that have been formulated in terms of a single morphological operation--biased dilation. Based on the spatial coding of a fuzzy variable, a bidirectional projection concept is proposed. Thus, fuzzy logic operations, arithmetic operations, gray-scale dilation, and erosion for the extended intrinsically fuzzy morphological operations can be included in a unified algorithm with only biased dilation and fuzzy logic operations. To execute this image algebra approach we present a cellular two-layer processing architecture that consists of a biased dilation processor and a fuzzy logic processor. (C) 1996 Optical Society of America

Logic-operated mathematical morphology and its optical implementation

A more powerful tool for binary image processing, i.e., logic-operated mathematical morphology (LOMM), is proposed. With LOMM the image and the structuring element (SE) are treated as binary logical variables, and the MULTIPLY between the image and the SE in correlation is replaced with 16 logical operations. A total of 12 LOMM operations are obtained. The optical implementation of LOMM is described. The application of LOMM and its experimental results are also presented. (C) 1999 Optical Society of America.

FUZZY SOLID SETS FOR MATHEMATICAL MORPHOLOGY AND OPTICAL IMPLEMENTATION

Fuzzy sets in the subject space are transformed to fuzzy solid sets in an increased object space on the basis of the development of the local umbra concept. Further, a counting transform is defined for reconstructing the fuzzy sets from the fuzzy solid sets, and the dilation and erosion operators in mathematical morphology are redefined in the fuzzy solid-set space. The algebraic structures of fuzzy solid sets can lead not only to fuzzy logic but also to arithmetic operations. Thus a fuzzy solid-set image algebra of two image transforms and five set operators is defined that can formulate binary and gray-scale morphological image-processing functions consisting of dilation, erosion, intersection, union, complement, addition, subtraction, and reflection in a unified form. A cellular set-logic array architecture is suggested for executing this image algebra. The optical implementation of the architecture, based on area coding of gray-scale values, is demonstrated. (C) 1995 Optical Society of America

Fuzzy inferring mathematical morphology and optical implementation

Fuzzification is introduced into gray-scale mathematical morphology by using two-input one-output fuzzy rule-based inference systems. The fuzzy inferring dilation or erosion is defined from the approximate reasoning of the two consequences of a dilation or an erosion and an extended rank-order operation. The fuzzy inference systems with numbers of rules and fuzzy membership functions are further reduced to a simple fuzzy system formulated by only an exponential two-input one-output function. Such a one-function fuzzy inference system is able to approach complex fuzzy inference systems by using two specified parameters within it-a proportion to characterize the fuzzy degree and an exponent to depict the nonlinearity in the inferring. The proposed fuzzy inferring morphological operators tend to keep the object details comparable to the structuring element and to smooth the conventional morphological operations. Based on digital area coding of a gray-scale image, incoherently optical correlation for neighboring connection, and optical thresholding for rank-order operations, a fuzzy inference system can be realized optically in parallel. (C) 1996 Society of Photo-Optical Instrumentation Engineers.

A model for energy and morphology of crystalline grain boundaries with arbitrary geometric character

It has been well-established that interfaces in crystalline materials are key players in the mechanics of a variety of mesoscopic processes such as solidification, recrystallization, grain boundary migration, and severe plastic deformation. In particular, interfaces with complex morphologies have been observed to play a crucial role in many micromechanical phenomena such as grain boundary migration, stability, and twinning. Interfaces are a unique type of material defect in that they demonstrate a breadth of behavior and characteristics eluding simplified descriptions. Indeed, modeling the complex and diverse behavior of interfaces is still an active area of research, and to the author's knowledge there are as yet no predictive models for the energy and morphology of interfaces with arbitrary character. The aim of this thesis is to develop a novel model for interface energy and morphology that i) provides accurate results (especially regarding "energy cusp" locations) for interfaces with arbitrary character, ii) depends on a small set of material parameters, and iii) is fast enough to incorporate into large scale simulations.

In the first half of the work, a model for planar, immiscible grain boundary is formulated. By building on the assumption that anisotropic grain boundary energetics are dominated by geometry and crystallography, a construction on lattice density functions (referred to as "covariance") is introduced that provides a geometric measure of the order of an interface. Covariance forms the basis for a fully general model of the energy of a planar interface, and it is demonstrated by comparison with a wide selection of molecular dynamics energy data for FCC and BCC tilt and twist boundaries that the model accurately reproduces the energy landscape using only three material parameters. It is observed that the planar constraint on the model is, in some cases, over-restrictive; this motivates an extension of the model.

In the second half of the work, the theory of faceting in interfaces is developed and applied to the planar interface model for grain boundaries. Building on previous work in mathematics and materials science, an algorithm is formulated that returns the minimal possible energy attainable by relaxation and the corresponding relaxed morphology for a given planar energy model. It is shown that the relaxation significantly improves the energy results of the planar covariance model for FCC and BCC tilt and twist boundaries. The ability of the model to accurately predict faceting patterns is demonstrated by comparison to molecular dynamics energy data and experimental morphological observation for asymmetric tilt grain boundaries. It is also demonstrated that by varying the temperature in the planar covariance model, it is possible to reproduce a priori the experimentally observed effects of temperature on facet formation.

Finally, the range and scope of the covariance and relaxation models, having been demonstrated by means of extensive MD and experimental comparison, future applications and implementations of the model are explored.

Optoelectronic implementation of mathematical morphology

An optoelectronic implementation based on optical neighborhood operations and electronic nonlinear feedback is proposed to perform morphological image processing such as erosion, dilation, opening, closing and edge detection. Results of a numerical simulation are given and experimentally verified.

Sphaerotilus natans: description of the morphology, growth and systematics of [Translation from: Schr. Ver. Zellstoff u. Pap.-Chem. u. -Ing., 26, 20-37, 1956]

The morphology, increase and systematica of Sphaerotilus natans is studied and culture methods examined.

Influence of thermal annealing on optical properties and surface morphology of NiOx thin films

NiOx thin films were deposited by reactive DC-magnetron sputtering from a nickel metal target in Ar + O-2 with the relative O-2 content of 5%. Thermal annealing effects on optical properties and surface morphology of NiOx, films were investigated by X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscope and optical measurement. The results showed that the changes in optical properties and surface morphology depended on the temperature. The surface morphology of the films changed obviously as the annealing temperature increased due to the reaction NiOx -> NiO + O-2 releasing O-2. The surface morphology change was responsible for the variation of the optical properties of the films. The optical contrast between the as-deposited films and 400 degrees C annealed films was about 52%. In addition, the relationship of the optical energy band gap with the variation of annealing temperature was studied. (c) 2006 Elsevier B.V. All rights reserved.