bluuebunny/crossref_metadata_2025 huggingface dataset:
THE IRON MACHINE: FROM LINCOLN TO DISFRANCHISEMENT The Lincoln enigma: the changing faces of an American icon. Edited by Gabor Boritt. New York: Oxford University Press, 2001. Pp. xxvii+323. ISBN 0-19-514458-9. £21.99. Abraham Lincoln: redeemer president. By Allen C. Guelzo. Grand Rapids, MI, and Cambridge: William B. Eerdmans, 1999. Pp. xi+516. ISBN 0-8028-3872-3. £19.99. Race and reunion: the Civil War in American memory. By David W. Blight. Cambridge, MA: Belknap Press of Harvard University Press, 2001. Pp. 512. ISBN 0-674-00332-2. £21.50. Thinking confederates: academia and the idea of progress in the New South. By Dan R. Frost. Knoxville: University of Tennessee Press, 2000. Pp. xiv+207. ISBN 1-57233-104-6. £19.00. Deep Souths: Delta, Piedmont, and Sea Island society in the age of segregation. By J. William Harris. Baltimore, MD: Johns Hopkins University Press, 2001. Pp. xii+454. ISBN 0-8018-6563-8. £31.00. Struggle for mastery: disfranchisement in the South, 1888–1908. By Michael Perman. Chapel Hill: University of North Carolina Press, 2001. Pp. xiii+397. ISBN 0-8078-2593-X. £42.50.
Authors: O'BRIEN MICHAEL
Published: March 2003

There are four presidents carved on Mount Rushmore: George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt. The case of George W. Bush would seem to suggest that modern Americans do not like their presidents to be complex. If so, among the granite faces, only Washington and Roosevelt answer to this need. The former possessed what his admirers called republican simplicity, what his enemies (and even some personal friends) thought might be a lack of intellectual nimbleness. The latter had a violence of conviction so wondrous in its clarity that numerous psychologists have been enlisted to find something beneath its surface. Jefferson, by contrast, was dizzyingly complex, but he is also inaccessible, especially to modernists who find an eighteenth-century sensibility eerily polished and cold. Abraham Lincoln, however, was satisfyingly messed up. A broken family, a lost lover, an unhappy marriage, dead children, plus years of thwarted ambition, nightmares, melancholy, and suicidal impulse, all combine to make a man of nervous inadequacy, someone whom Oprah Winfrey would be glad to have back, again and again, as an icon of the perennial crises of masculinity.
SQUATTERS, LAND SALES AND INTENSIFICATION IN MARIRANGWE PURCHASE AREA, COLONIAL ZIMBABWE, 1931–65
Authors: SHUTT ALLISON K.
Published: March 2003

This article considers the different ways that Marirangwe purchase area farmers understood and used their farmland, resources and opportunities. In the pioneer period from 1931 to the 1940s, Marirangwe farmers favored extensive use of their land and its resources. However, as labor and capital opportunities changed, land became for some an expendable commodity. By the 1950s, the farmers' ability to generate capital through land sales paralleled the arrival of squatters in the area. With the help of these squatters and revenue from land sales, Marirangwe farmers prospered. This development, however, did not signal a change from the extensive farming habits of the pioneer period but rather a brief, and generally prosperous, period of specialization.
‘NO KINGS, NO LORDS, NO SLAVES’: ETHNICITY AND RELIGION AMONG THE SEREER-SAFÈN OF WESTERN BAWOL, 1700–1914
Authors: SEARING JAMES F.
Published: March 2003

The Sereer-Safèn occupied a defensible refuge zone in Western Bawol, where forests and sandstone ridges provided protection against Wolof monarchy. The Safèn were part of a larger ‘Sereer’ world that defined itself by opposition to Islam in the period from 1700 to 1914. This religious divide made the Sereer targets for enslavement by the Wolof, but Sereer religion was also linked to Safèn resistance to Islam, slavery and monarchy. Religion was interwoven with an ethnic boundary, which emphasized the incompatibility of Wolof and Sereer society. Safèn religion was centered on the village ‘shrine’ or xérém, which served as the focal point of ritual, justice, communication with the other world and defense.
DOGS, POISON AND THE MEANING OF COLONIAL INTERVENTION IN THE TRANSKEI, SOUTH AFRICA
Authors: TROPP JACOB
Published: March 2003

In the 1890s and 1900s in the Transkei, South Africa, colonial relations were severely strained as Cape colonial officials attempted to constrain African men's hunting activities by systematically poisoning and shooting their dogs. For colonial foresters, such efforts were part of a larger strategy to ‘protect’ flora and fauna by controlling African environmental activities and mobility more thoroughly. Yet on the ground in many areas, state-sponsored dog-killing was drawn into more complex understandings of, and popular frustrations with, transformations in local landscapes and livelihoods during this period. As rural men and women responded to the particular changes in their local political ecologies arising from colonial wildlife preservation policies, they also located conflicts over state forestry and its policies of exclusion within broader popular experiences of political, economic and ecological subordination. In several communities, rumors and stories proliferated, connecting the killing of dogs to other official attempts to poison and bewitch Africans, their animals and their landscapes. Such stories were ways for people to express deeper concerns over the spreading influence of colonial power in their daily practices and its toll on local communities’ health and welfare.
GRUESOME RUMOURS, THE REALITY QUESTION
AND WRITING HISTORY
Authors: GESCHIERE PETER
Published: March 2003

Madumo: A Man Bewitched. By ADAM ASHFORTH. Chicago: University of Chicago
Press; Cape Town: David Philip, 2000. Pp. vii+255. Rand 90 (ISBN 0-226-02971-9).

Speaking with Vampires: Rumor and History in Colonial Africa. By LUISE WHITE.
Berkeley: University of California Press, 2000. Pp. xvi+351. £31.50/$50 (ISBN
0-520-21703-9); £12.50/$19.95, paperback (ISBN 0-520-21704-7).
Evolution of a narrow-band spectrum of random surface gravity waves
Authors: DYSTHE KRISTIAN B. , TRULSEN KARSTEN , KROGSTAD HARALD E. , SOCQUET-JUGLARD HERVÉ
Published: March 2003

Numerical simulations of the evolution of gravity wave spectra of fairly narrow bandwidth have been performed both for two and three dimensions. Simulations using the nonlinear Schrödinger (NLS) equation approximately verify the stability criteria of Alber (1978) in the two-dimensional but not in the three-dimensional case. Using a modified NLS equation (Trulsen et al. 2000) the spectra ‘relax’ towards a quasi-stationary state on a timescale (ε2ω0)−1. In this state the low-frequency face is steepened and the spectral peak is downshifted. The three-dimensional simulations show a power-law behaviour ω−4 on the high-frequency side of the (angularly integrated) spectrum.
Zero wave resistance for ships moving in shallow channels at supercritical speeds. Part 2. Improved theory and model experiment
Authors: CHEN XUE-NONG , SHARMA SOM DEO , STUNTZ NORBERT
Published: March 2003

This paper deals with a specially designed slender ship moving steadily at a chosen supercritical speed in a suitable narrow shallow channel such that the wave resistance becomes zero. It is a sequel to Chen & Sharma (1997), which predicted theoretically the existence of a ship–channel configuration of zero wave resistance. It was derived from a two-soliton solution of the Kadomtsev–Petviashvili equation. The present theory comprises an improved shallow-water wave equation of Boussinesq type for the far field and an enhanced slender body approximation in the near field. Moreover, a physical model experiment performed in the Duisburg shallow water towing tank (VBD) is reported. It confirms that at the exact design condition the ship's reflected bow wave cancels the stern wave so completely that there are almost no waves behind the ship and the measured resistance is reduced so much that the wave resistance component is practically zero.
Laminar starting plumes in high-Prandtl-number fluids
Authors: KAMINSKI EDOUARD , JAUPART CLAUDE
Published: March 2003

Experimental studies of laminar axisymmetric starting plumes are performed to investigate the dependence of the flow on the Prandtl number, focusing on large Prandtl numbers. Thermal plumes are generated by a small electric heater in a glass tank filled with viscous oils. Prandtl numbers in the range of 7–104 were investigated. Experimental conditions are such that viscosity variations due to temperature differences are negligible. Plumes ascend in two different regimes as a function of distance to source. At short distances, the plumes accelerate owing to the development of the viscous boundary layer. At distances larger than about five times the heater size, the ascent velocity is constant and increases as a function of the Prandtl number, as predicted by theory for steady plumes. This velocity is, within experimental error, proportional to the steady plume centreline velocity.
Shoaling solitary internal waves: on a criterion for the formation of waves with trapped cores
Authors: LAMB KEVIN G.
Published: March 2003

Shoaling solitary internal waves are ubiquitous features in the coastal regions of the world's oceans where waves with a core of recirculating fluid (trapped cores) can provide an effective transport mechanism. Here, numerical evidence is presented which suggests that there is a close connection between the limiting behaviour of large-amplitude solitary waves and the formation of such waves via shoaling. For some background states, large-amplitude waves are broad, having a nearly horizontal flow in their centre. The flow in the centre of such waves is called a conjugate flow. For other background states, large-amplitude waves can reach the breaking limit, at which the maximum current in the wave is equal to the wave's propagation speed. The presence of a background current with near-surface vorticity of the same sign as that induced by the wave can change the limiting behaviour from the conjugate-flow limit to the breaking limit. Numerical evidence is presented here which suggests that if large solitary waves cannot reach the breaking limit in the shallow water, that is if the background flow has a conjugate flow, then waves with trapped cores will not be formed via shoaling. It is also shown that, due to a change in the limiting behaviour of large waves, an appropriate background current can enable the formation of waves with trapped cores in stratifications for which such waves are not formed in the absence of a background current.
Turbulence over a compliant surface: numerical simulation and analysis
Authors: XU S. , REMPFER D. , LUMLEY J.
Published: March 2003

In this paper we present results from a numerical investigation of turbulent channel
flow in the presence of a compliant wall. The compliant wall is modelled as a homogeneous
spring-supported plate. The simulation code is validated both by comparison with an alternative
code and by reproducing results of linear stability theory. Our results demonstrate that with
the wall compliance we used in the simulation there is little change in the very long-time
behaviour of the turbulent skin friction drag and little modification to the near-wall
turbulent coherent structures. The values of pertinent statistical quantities of the
turbulence near the compliant walls converge to those near a rigid wall and the statistical
effect of the wall compliance on the turbulent channel flow is small.
Three-dimensional acoustic-roughness receptivity of a boundary layer on an airfoil: experiment and direct numerical simulations
Authors: WÜRZ W. , HERR S. , WÖRNER A. , RIST U. , WAGNER S. , KACHANOV Y. S.
Published: March 2003

The paper is devoted to an experimental and numerical investigation of the problem of
excitation of three-dimensional Tollmien–Schlichting (TS) waves in a boundary layer on
an airfoil owing to scattering of an acoustic wave on localized microscopic surface non-uniformities.
The experiments were performed at controlled disturbance conditions on a symmetric airfoil section
at zero angle of attack. In each set of measurements, the acoustic wave had a fixed frequency
fac, in the range of unstable TS-waves. The three-dimensional
surface non-uniformity was positioned close to the neutral stability point at branch I
for the two-dimensional perturbations. To avoid experimental difficulties in the distinction of
the hot-wire signals measured at the same (acoustic) frequency but having a different physical
nature, the surface roughness was simulated by a quasi-stationary surface non-uniformity
(a vibrator) oscillating with a low frequency fv. This led to
the generation of TS-wavetrains at combination frequencies
f1,2=fac ∓
fv. The spatial behaviour of these wavetrains has been
studied in detail for three different values of the acoustic frequency. The disturbances
were decomposed into normal oblique TS-modes. The initial amplitudes and phases of these modes
(i.e. at the position of the vibrator) were determined by means of an upstream extrapolation of
the experimental data. The shape of the vibrator oscillations was measured by means of a laser
triangulation device and mapped onto the Fourier space.
Vorticity production in shock diffraction
Authors: SUN M. , TAKAYAMA K.
Published: March 2003

The production of vorticity or circulation production in shock wave diffraction over sharp convex corners has been numerically simulated and quantified. The corner angle is varied from 5° to 180°. Total vorticity is represented by the circulation, which is evaluated by integrating the velocity along a path enclosing the perturbed region behind a diffracting shock wave. The increase of circulation in unit time, or the rate of circulation production, depends on the shock strength and wall angle if the effects of viscosity and heat conductivity are neglected. The rate of vorticity production is determined by using a solution-adaptive code, which solves the Euler equations. It is shown that the rate of vorticity production is independent of the computational mesh and numerical scheme by comparing solutions from two different codes. It is found that larger wall angles always enhance the vorticity production. The vorticity production increases sharply when the corner angle is varied from 15° to 45°. However, for corner angles over 90°, the rate of vorticity production hardly increases and reaches to a constant value. Strong shock waves produce vorticity faster in general, except when the slipstream originating from the shallow corner attaches to the downstream wall. It is found that the vorticity produced by the slipstream represents a large proportion of the total vorticity. The slipstream is therefore a more important source of vorticity than baroclinic effects in shock diffraction.
Air entrapment under an impacting drop
Authors: THORODDSEN S. T. , ETOH T. G. , TAKEHARA K.
Published: March 2003

When a drop impacts on a liquid surface it entraps a small amount of air under its centre as the two liquid surfaces meet. The contact occurs along a ring enclosing a thin disk of air. We use the next-generation ultra-high-speed video camera, capable of 1 million f.p.s. (Etoh et al. 2002), to study the dynamics of this air sheet as it contracts due to surface tension, to form a bubble or, more frequently, splits into two bubbles. During the contraction of the air disk an azimuthal undulation, resembling a pearl necklace, develops along its edge. The contraction speed of the sheet is accurately described by a balance between inertia and surface tension. The average initial thickness of the air sheet decreases with higher impact Reynolds numbers, becoming less than one micron. The total volume of air entrapped depends strongly on the bottom curvature of the drop at impact. A sheet of micro-bubbles is often observed along the original interface. Oguz–Prosperetti bubble rings are also observed. For low Weber numbers (We<20) a variety of other entrapment phenomena appear.
Particle image velocimetry and visualization of natural and forced flow around rectangular cylinders
Authors: MILLS RICHARD , SHERIDAN JOHN , HOURIGAN KERRY
Published: March 2003

Particle image velocimetry (PIV) measurements and flow visualization in a water tunnel show that vortex shedding at the leading and trailing edges of rectangular cylinders can be simultaneously phase-locked to transverse velocity perturbations when the applied perturbation Stp is close to an impinging leading-edge vortex/trailing-edge vortex shedding (ILEV/TEVS) frequency. The transverse perturbations, analogous to β-mode duct acoustic resonances, are generated through harmonic oscillations of the sidewalls. When this occurs, the leading-edge vortices are found always to pass the trailing edge at the same phase in the perturbation cycle regardless of the chord-to-thickness (c/t) ratio. Applying perturbations at an Stp not equal to the natural global frequency also results in phase-locked vortex shedding from the leading edge, and a near wake with a frequency equal to the perturbation frequency. This is consistent with previous experimental findings. However, vortex shedding at the trailing edge is either weaker or non-existent. PIV results and flow visualization showed trailing-edge vortex growth was weaker because leading-edge vortices arrive at the trailing edge at a phase in the perturbation cycle where they interfere with trailing-edge shedding. The frequencies at which trailing-edge vortices form for different c/t ratios correspond to the natural ILEV/TEVS frequencies. As in the case of natural shedding, peaks in base suction occur when the leading-edge vortices pass the trailing edge at the phase in the perturbation cycle (and thus in the leading-edge shedding cycle) that allows strong trailing-edge shedding. This is the reason for the similarity in the Stvs.c/t relationship for three seemingly different sets of experiments.
Three-dimensional airway reopening: the steady propagation of a semi-infinite bubble into a buckled elastic tube
Authors: HAZEL ANDREW L. , HEIL MATTHIAS
Published: March 2003

We consider the steady propagation of an air finger into a buckled elastic tube initially filled with viscous fluid. This study is motivated by the physiological problem of pulmonary airway reopening. The system is modelled using geometrically nonlinear Kirchhoff–Love shell theory coupled to the free-surface Stokes equations. The resulting three-dimensional fluid–structure-interaction problem is solved numerically by a fully coupled finite element method.

The system is governed by three dimensionless parameters: (i) the capillary number,
Ca=μU/σ*, represents the ratio of viscous to surface-tension
forces, where μ is the fluid viscosity, U is the finger's propagation speed
and σ* is the surface tension at the air–liquid interface; (ii)
σ=σ*/(RK) represents the ratio of surface tension to elastic forces, where
R is the undeformed radius of the tube and K its bending modulus; and (iii)
A∞=A*∞/(4R2), characterizes the initial degree of tube collapse, where
A*∞ is the cross-sectional area of the tube far ahead of the bubble.

The generic behaviour of the system is found to be very similar to that observed in previous two-dimensional models (Gaver et al. 1996; Heil 2000). In particular, we find a two-branch behaviour in the relationship between dimensionless propagation speed, Ca, and dimensionless bubble pressure, p*b/(σ*/R). At low Ca, a decrease in p*b is required to increase the propagation speed. We present a simple model that explains this behaviour and why it occurs in both two and three dimensions. At high Ca, p*b increases monotonically with propagation speed and p*b/(σ*/R) ∝ Ca for sufficiently large values of σ and Ca. In a frame of reference moving with the finger velocity, an open vortex develops ahead of the bubble tip at low Ca, but as Ca increases, the flow topology changes and the vortex disappears.

An increase in dimensional surface tension, σ*, causes an increase in the bubble pressure required to drive the air finger at a given speed; p*b also increases with A*∞ and higher bubble pressures are required to open less strongly buckled tubes. This unexpected finding could have important physiological ramifications. If σ* is sufficiently small, steady airway reopening can occur when the bubble pressure is lower than the external (pleural) pressure, in which case the airway remains buckled (non-axisymmetric) after the passage of the air finger. Furthermore, we find that the maximum wall shear stresses exerted on the airways during reopening may be large enough to damage the lung tissue.
Three-dimensional wave effects on a steady current
Authors: GROENEWEG J. , BATTJES J. A.
Published: March 2003

Measurements in a laboratory flume have shown unexpected wave-induced changes in the vertical profile of the mean horizontal velocity. Two theoretical explanations for these changes have been proposed so far. One is based on a local force balance in the longitudinal direction and the other relies on secondary circulations in the cross-sectional plane. In this study, a two-dimensional (2DV lateral) model based on the so-called generalized Lagrangian mean (GLM) formulation has been developed to investigate the three-dimensional effect of waves on the steady current and in particular to investigate the validity of the two fundamentally different explanations. Formulations for the three-dimensional wave-induced driving force have been implemented in an existing 2DV non-hydrostatic numerical flow model. Computations for regular waves following and opposing a turbulent current over a horizontal bed have been carried out and the results are compared with both experimental results and results from an existing numerical model. The results clearly indicate predominance of the longitudinal component of the wave-induced driving force over the cross-sectional components. Although the 2DV model has only been applied to and verified with measurements in wave–current systems in a laboratory flume, the approach followed here is relevant for a wider class of problems of wave–current interactions.
Large-scale structures in a developed flow over a wavy wall
Authors: GÜNTHER AXEL , VON ROHR PHILIPP RUDOLF
Published: March 2003

We address – motivated in part by the findings of Gong et al. (1996) and Miller (1995) – the role of streamwise-oriented large-scale structures in a developed flow between a sinusoidal bottom wall and a flat top wall. Particle image velocimetry (PIV) is used to examine the spatial variation of the velocity in different planes of the flow through a water channel with an aspect ratio of 12:1. The wave amplitude is equal to one tenth of the wall wavelength, Λ, and Reynolds numbers between 500 and 7300, defined with the bulk velocity and the half-height of the channel, are considered. To examine streamwise-oriented structures, the spanwise variation of the velocity field is studied in a plane parallel to the top wall, and in one that intersects the wavy surface at an uphill location. From a proper orthogonal decomposition (POD) of the streamwise velocity fluctuations, we obtain the dominant eigenfunctions with a characteristic spanwise scale of O(1.5Λ), which agrees with the scale of perturbations for the streamwise velocity at laminar conditions. A decomposition of the turbulent velocity field close to the uphill section of the wavy surface reveals smaller structures at a location that coincides with the Reynolds shear stress maximum.
Intermittency in solutions of the three-dimensional Navier–Stokes equations
Authors: GIBBON J. D. , DOERING Charles R.
Published: March 2003

Dissipation-range intermittency was first observed by Batchelor & Townsend (1949) in high Reynolds number turbulent flows. It typically manifests itself in spatio-temporal binary behaviour which is characterized by long, quiescent periods in the signal which are interrupted by short, active ‘events’ during which there are large excursions away from the average. It is shown that Leray's weak solutions of the three-dimensional incompressible Navier–Stokes equations can have this binary character in time. An estimate is given for the widths of the short, active time intervals, which decreases with the Reynolds number. In these ‘bad’ intervals singularities are still possible. However, the average width of a ‘good’ interval, where no singularities are possible, increases with the Reynolds number relative to the average width of a bad interval.
Production and control of sound by the small sperm whales, Kogia breviceps and K. sima and their implications for other Cetacea
Authors: Clarke M.R.
Published: March 2003

The detailed anatomy of the noses of Kogia breviceps and K. sima (Kogiidae: Cetacea) is described in greater detail than previously. Probable functions of component parts of the nose are deduced from their geometry and physical properties of the tissues. It is concluded that control of the air making the sound is similar to that found in scottish bagpipes with a single reed, that sounds are produced by air being forced from the vocal valve and is resonated in an unusual chamber having cords and membranes, similar to human vocal cords. It is then reflected by air filled ‘mirrors’ and conducted and intensified through a megaphone-like ‘horn’ which is surrounded by air and contains tissues rich in spermaceti oil. Sound then passes through the melon where, by changes in temperature of the spermaceti oil, it is actively focused and possibly scanned. Thermal properties of Kogia spermaceti oil are described and related to previously made sound velocity and density measurements. The way sound production and reflection can continue while large variations of pressure are experienced during deep dives, is suggested. A structure for controlling the temperature of the melon is described. It is considered unlikely that the spermaceti oil is used for buoyancy control in Kogia. Some comparisons are drawn with Physeter catodon, Xiphius and Tursiops and some implications for research on other cetaceans are outlined.
True and false threatening visual cues in some Mediterranean fish
Authors: Bedini Roberto , Canali Maria Grazia , Bedini Andrea
Published: March 2003

Mediterranean fish of the Trachinidae and Uranoscopidae families are characterized by a poison apparatus on the 1st dorsal fin. These fish hide by burying themselves in the sand using cryptic mimicry. Nevertheless, if they are discovered before they have completely buried themselves, or perceive a potential source of danger when already covered, they will raise their 1st dorsal fin which has a bright black spot on the inter-radial membrane. We have shown that this black vexillum acts as a threatening visual cue and that the movements accompanying black mark display can be defined as aggressive mimicry.  We therefore thought it interesting to investigate the black mark display in some species of Soleidae, a behaviour never before reported in the literature. In these fish, the black marks are situated on the right pectoral fin which, as a result of the distortion and re-arrangement of some anatomical parts during development, shifts to a dorsal position in adults. Soles also bury themselves in the sand, and they too display their marked fins on the approach of a possible predator, just like fish belonging to the above dangerous families.
Spatial distribution, substrate assemblages and size composition of sea horses (Family Syngnathidae) in the coastal waters of Peninsular Malaysia
Authors: Choo C.K. , Liew H.C.
Published: March 2003

Four species of sea horses (Syngnathidae: Hippocampus) were found in Peninsular Malaysia during a survey conducted between April and August 2001. These were Hippocampus trimaculatus, H. spinosissimus, H. kuda and H. kelloggi. All four species were found in the Straits of Malacca; two species (H. trimaculatus and H. spinosissimus) in the east coast of Peninsular Malaysia in the South China Sea; and three species: H. trimaculatus, H. spinosissimus and H. kuda in the south coast, Straits of Johor. There were habitat and depth separations by species. Hippocampus trimaculatus, which was found throughout the coastal waters of the Peninsular, were reported to inhabit chiefly among gorgonians at approximately 20–40 m depth. The habitat and depth in H. spinosissimus were rather similar to that of H. trimaculatus; but the former species was less widespread in the west coast. Hippocampus kuda was confined to shallow water between 1 to 3 m, and was found in seaweeds and sea grass meadows in a few estuaries; whereas H. kelloggi inhabited gorgonians and sea whips in deep-water below 65 m. Mean standard lengths are given. No sexual size dimorphism was detected in any of the species.
Specific Merluccius otolith growth patterns related to phylogenetics and environmental factors
Authors: Lombarte A. , Torres G.J. , Morales-Nin B.
Published: March 2003

A comparative morphological study was performed on the otolith growth patterns of 11 species of the genus Merluccius. The otolith growth pattern, based on the radius of the first eight growth increments (GI) from the otolith core, was determined from transverse sections of sagitta otoliths. The structure and periodicity of the GI were identified based on previous knowledge. Two cluster analyses were performed using GI width as a proxy for otolith growth. The first cluster analysis corresponded to the juvenile (immature) period of the fish including the mean width of the first four GI. The second analysis compared the mean width of the next four GI, i.e. those corresponding to mature fish. The results showed an important environmental influence in immature fish; while after maturation, the GI pattern was also related to an endogenous influence depending on the phylogenetic line.
Arsenic concentrations correlate with salinity for fish taken from the North Sea and Baltic waters
Authors: Larsen Erik H. , Francesconi Kevin A.
Published: March 2003

Total arsenic concentrations were determined in three teleost species (herring Clupea harengus; cod Gadus morhua, and flounder Platichthys flesus) taken from four locations in the Baltic and North Sea with salinities ranging from 8 to 32 psu. Individual arsenic concentrations ranged from 0·04 to 10·9 mg/kg wet mass, and there was a positive linear relationship between arsenic concentration and salinity for all three species (r2 0·44 to 0·72, all P<0·001). Although it is well known that marine fish contain much higher concentrations of arsenic than do freshwater fish, the data reported here are the first showing a relationship between the total arsenic concentration in fish and salinity.
Locomotor performance in the sea urchin Paracentrotus lividus
Authors: Domenici P. , González-Calderón D. , Ferrari R.S.
Published: March 2003

The locomotor performance of the Mediterranean sea urchin Paracentrotus lividus was investigated under laboratory conditions. Individuals were placed singly in the centre of a glass surface positioned either horizontally or vertically in tanks with seawater, and their locomotor activity was recorded. For locomotion on a horizontal surface, speed increased with both sea urchin diameter and their straightness of path. Speeds on a vertical surface were size-independent and not related to the straightness of path, although they were affected by vertical path orientation, with the highest speeds occurring for downward movements and the slowest speeds for the upward movements. Taken together, these results suggest that the scaling of sea urchin locomotion may follow similar laws to those of legged animals, for which locomotor performance increases with size on horizontal surface, while their relative cost of locomotion increases with body size on inclined surfaces. It is suggested that differences in horizontal vs vertical locomotion may also be related to differences in the underlying locomotor mechanisms, i.e. using adhesive appendices (tube feet) or levers (spines). In a second experiment, the sea urchin speed obtained during a negative phototactic response to a direct light stimulus was recorded. The results show that speed during light stimulation is higher than that during spontaneous locomotion in sea urchins of intermediate size (2·5–4 cm), suggesting that, in addition to the direction of locomotion as shown by previous studies, light can also have an effect on speed.
Digenean trematodes moderately alter Hydrobia ulvae population size structure
Authors: de Montaudouin Xavier , Blanchet Hugues , Kisielewski Isabelle , Desclaux Céline , Bachelet Guy
Published: March 2003

The mudsnail Hydrobia ulvae, primary host to a number of digeneans, was studied to check whether parasite effects on individual hosts could have repercussion on population size structure and dynamics. Three different mudsnail populations were monitored monthly in Arcachon Bay, south-west France. Arguin is a moderately sheltered oceanic sandflat and a bird reserve, La Canelette is a sheltered sandflat near a harbour and Lette Douce is a sheltered salt marsh. Parasite prevalence differed among the three stations, with no obvious seasonal pattern: 0–16% at Arguin, 0–6% at La Canelette and 1–5% at Lette Douce. Between four and five digenean species were identified, with Haploporidae dominating at Arguin and Notocotylidae dominating at Lette Douce. Prevalence increased with snail shell height. Large snails from Arguin were heavily parasitized, but suddenly disappeared between December 1998 and January 1999. The snail size distribution was consequently modified. To test whether digenean-induced mortality could be involved, a 50-d laboratory experiment was performed. Mudsnails hosting digeneans with rediae (as Haploporidae or Heterophyidae) displayed significantly higher mortality rates than mudsnails hosting sporocysts (as Microphallidae) or healthy mudsnails. The present study demonstrates that digenean parasites induce population structure changes and shorten lifespan of mudsnails, through increasing size-dependent mortality.
Spatial heterogeneity in parasite loads in the New Zealand cockle: the importance of host condition and density
Authors: Mouritsen K.N. , McKechnie S. , Meenken E. , Toynbee J.L. , Poulin R.
Published: March 2003

Samples of the New Zealand cockle Austrovenus stutchburyi (Veneridae) collected at two different intertidal levels were found to be heavily infected by the echinostome trematode Curtuteria australis which use the mud flat whelk Cominella glandiformis and shorebirds as first and definitive host, respectively. Parasite loads were on average more than 2-fold higher at the high site than at the low site, whereas the density of Curtuteria australis metacercariae per square metre showed the opposite trend. This pattern appeared unrelated to the abundance of first intermediate hosts and C. australis prevalence within this host that did not differ between sites. At both sites there was a positive relationship between parasite load and cockle condition, a likely by-product of the relationship between condition-based filtration capacity and the rate at which individual cockles encounter the free-swimming trematode larvae. The results suggest that the between-site variation in parasitism is a consequence of the much higher density of cockles at the low site. There, the dense cockle population is able to clear the water column of parasites and consequently individual cockles virtually ‘compete’ for parasite larvae. This will depress mean infection intensity per cockle but elevate mean parasite density per square metre.
Pathologies elicited by the gymnophallid metacercariae of Bartolius pierrei in the clam Darina solenoides
Authors: Cremonte Florencia , Ituarte Cristián
Published: March 2003

Darina solenoides (Mactridae), a common intertidal bivalve in the Argentine Patagonian coast, serves as both first and second intermediate host for the gymnophallid Bartolius pierrei (Trematoda: Digenea). Cercariae enter the clams actively by piercing the mantle border; young metacercariae ascend along the space between the outer mantle epithelium and shell and they settle in the dorsal general extrapallial space just ahead of the posterior adductor muscle. Host reaction comprises mantle tissue alterations (hyperplasia and metaplasia) leading to the encapsulation of the metacercariae by the formation of a one-cell-layer thick sac, which progressively detaches from the mantle epithelium. Sacs containing fully developed metacercariae, which are surrounded by a hyaline non-cellular envelope, become internal and are found in the postero-dorsal region of the visceral mass. Two sacs usually containing from two to 44 metacercariae, one at each side of the clam, were observed. In some cases, in which the infection seems not to proceed as usual, dead and dying metacercariae and their debris were found in the same position within the extrapallial space where the host reaction usually starts. In these cases, the mantle reaction is accompanied by an inner shell surface alteration consisting of calcium carbonate deposits partially surrounding the reaction complex or other abnormal calcifications in the form of loose mineral concretions.
The habitat harshness hypothesis revisited: life history of the isopod Excirolana braziliensis in sandy beaches with contrasting morphodynamics
Authors: Defeo Omar , Martínez Gastón
Published: March 2003

Demographic and life history characteristics of the intertidal isopod Excirolana braziliensis (Isopoda: Cirolanidae) were compared between populations of two exposed sandy beaches with contrasting morphodynamics (reflective vs dissipative) during 22 consecutive months. Most population processes and life history traits did not give support for the ‘habitat harshness hypothesis’ (HHH): abundance of males, females, ovigerous females and juveniles was significantly higher at the reflective beach population, which also presented higher growth rates in size and weight with respect to the dissipative beach population. No significant differences in weight-at-length were found between beaches. Among the compared parameters, only the lower natural mortality rates at the dissipative beach gave support for the HHH. The results were not consistent with a previous analysis of Excirolana braziliensis along Pan-American beaches, which showed that this isopod occurs almost invariably in fine sands of tropical and temperate beaches. The results give strong support to recent findings that show that in macrofauna species capable of sustaining large populations across a wide spectrum of physical conditions, such as Excirolana braziliensis, beach morphodynamics should not be considered the primary factor affecting abundance and life history traits. Instead, our results reinforce the view that sandy beach populations are controlled by the intertwined forces of biotic and abiotic factors operating together.
Nebalia troncosoi sp. nov., a new species of leptostracan (Crustacea: Phyllocarida: Leptostraca) from Galicia, Iberian Peninsula (north-east Atlantic)
Authors: Moreira Juan , Cacabelos Eva , Domínguez Marta
Published: March 2003

A new species of leptostracan (Crustacea: Phyllocarida: Leptostraca) belonging to the genus Nebalia, N. troncosoi sp. nov., is described from specimens collected off the Galician coast (Iberian Peninsula, north-east Atlantic). The new species is relatively common in sandy bottoms. It is characterized by having a long rostrum, an eye with small distal lobes, an antennular flagellum with up to seven articles, the exopod of the second maxilla longer than the first article of the endopod, and acute denticles along the posterior dorsal border of pleonites 6–7.
A new species of Pagurus (Decapoda: Anomura: Paguridae) from Brazil
Authors: Nucci Paulo Ricardo , de Melo Gustavo Augusto S.
Published: March 2003

A new species of the hermit crab genus Pagurus (Crustacea: Anomura: Paguridae) is described from Brazil. This is the first new species described in 30 years, with morphological characteristics of the exilis group.
A new species of Tortanus (Atortus) (Copepoda: Calanoida: Tortanidae) from Rodrigues Island, Mauritius
Authors: Ohtsuka Susumu , Conway David V.P.
Published: March 2003

A new species of the copepod genus Tortanus (Atortus) (Copepoda: Calanoida), T. (A.) insularis, is described from the coastal region of Rodrigues Island, Mauritius, an isolated island in the south-western Indian Ocean. This new species can be assigned to an Indian faunal element, the recticauda species group, in the Indo-West Pacific recticauda species complex. It exhibits the closest relationship to T. (A.) recticauda recorded from the southern Red Sea and Arabian Gulf, rather than the closer distributed T. (A.) capensis, recorded from off South Africa.
Notes on the ultrastructure of the setae on the fourth antennulary segment of the Balanus amphitrite cyprid (Crustacea: Cirripedia: Thoracica)
Authors: Lagersson N.C. , Garm A. , Høeg J.T.
Published: March 2003

This study presents electron microscopy (SEM, TEM) observations on the putative settlement receptors of the fourth antennulary segments. The TEM data from all nine setae are from the outer dendritic segment. Eight of them have morphological characteristics, indicating bimodal sensory properties while one seta (sE) is presumed to be a unimodal mechanoreceptor. We suggest that setae A and B are stimulated by the water flow, seta D is olfactory, seta E detects the topography of the substratum by touch, and the subterminal setae are touch chemoreceptors. No function is suggested for seta C.
Two new species of the genus Leodamas (Orbiniidae: Scolecida: Polychaeta) from the Pacific coast of Panama
Authors: López Eduardo , Cladera Pedro , San Martín Guillermo
Published: March 2003

A number of mangrove systems with associated tidal flats occur in Coiba Island, located off the Pacific coast of Panama, two of which were selected for the present study: Santa Cruz and El Gambute. Three transects were selected on each tidal flat and three sampling sites were arranged along each one: lower, middle and upper intertidal. During 1997, two samplings were carried out at each site, in February and November. The results of the faunistic studies revealed the presence of ten species of Orbiniidae, two of which belonged to the genus Leodamas. Leodamas minutus sp. nov. is easily distinguished from all other species within the genus by having a cylindrical thorax composed of 13 chaetigers, the first three chaetigers without notopodial lobes, thoracic neuropodia without postchaetal process, and abdominal neuropodia, short, bilobed and with protruding acicula. Leodamas platythoracicus sp. nov. can be recognized by its thorax, distinctly flattened in the posterior half and consisting of about 19 chaetigers, by its thoracic neuropodia, with many spines arranged in one or two rows and few, if any, slender capillaries, and by the shape of its abdominal neuropodia, which are long and subterminally notched and bear a distal process.
Life history, morphology and distribution of Dipolydora armata (Polychaeta: Spionidae)
Authors: Radashevsky Vasily I. , Nogueira João M.
Published: March 2003

The spionid polychaete Dipolydora armata, a borer in calcareous substrata, is recorded for the first time from Belize, Brazil, Taiwan, and Vietnam. Specimens from these and other localities, as well as the type material of Polydora armata from Madeira Island and Polydora rogeri from the Mediterranean were examined and all the specimens were considered to be conspecific. Dipolydora armata is up to 8 mm long (usually 2–3 mm), with up to 45 segments (usually 25–35 segments), an incised prostomium, caruncle until the end of segment 2, up to 10 pairs of branchiae from segment 7, up to 20 awl-like modified spines per notopodium in up to 15 posterior segments, bilobed or cup-shaped pygidium, hooded hooks from segment 7 accompanied by capillaries throughout the body, major falcate spines of segment 5 with a large lateral tooth and an apical structure covered by fine bristles and appearing as a cowling or third tooth on the convex side of the main fang.  The life history of the species includes a period of asexual reproduction by architomy beginning soon after settlement, then sexual maturation and continuous breeding within an extended period with production of lecithotrophic larvae developing entirely inside egg capsules. Once mature, individuals probably reproduce only sexually and do not undergo additional architomic divisions.  Asexual reproduction results in high morphological variability of adult individuals, particularly in number, size, and arrangement of awl-like spines in notopodia. Polydora rogeri is placed into synonymy of D. armata. The original interpretation of the relationship between the polychaetes and the excavating sponge Cliona viridis as mutualistic symbiosis is discussed. Dipolydora armata is considered to be a widespread non-specialized borer perforating various calcareous substrata.
Taxonomy of Plakortis and Plakinastrella (Demospongiae: Plakinidae) from oceanic islands off north-eastern Brazil, with description of three new species
Authors: Moraes Fernando C. , Muricy Guilherme
Published: March 2003

Three species of Plakortis and one of Plakinastrella (Demospongiae: Homosclerophorida) collected mostly at oceanic islands off north-eastern Brazil (Atol das Rocas, Fernando de Noronha and São Pedro e São Paulo Archipelago) are described, three of which are new to science: Plakortis angulospiculatus, P. insularis sp. nov., P. microrhabdifera sp. nov, and Plakinastrella microspiculifera sp. nov. External morphological characters such as colour, oscules, and consistency are sufficient to discriminate all the four species in the field, except Plakortis angulospiculatus from P. microrhabdifera. Internal features such as skeletal arrangement, shape and size of diods, and presence of microrhabds and calthrops are also important taxonomic characters for western Atlantic Plakortis and Plakinastrella. We consider as valid only five species of Plakortis in the western Atlantic: the three species described here plus P. halichondrioides and P. zyggompha. All these species except P. zyggompha have been recorded from Brazil. Plakinastrella has now two species in the western Atlantic, P. onkodes and P. microspiculifera sp. nov. The generic distinction between Plakortis and Plakinastrella is tenuous, based only on the presence of spicule size-classes and of deformed vs normal calthrops, and both genera need detailed revision.
Morphology and stomatogenesis of Pseudocohnilembus hargisi (Ciliophora: Scuticociliatida)
Authors: Ma Hongwei , Song Weibo , Hu Xiaozhong , Warren Alan
Published: March 2003

The morphology and stomatogenesis of the marine scuticociliate Pseudocohnilembus hargisi collected from a shrimp culturing pond in Qingdao, China, were studied using pyridinated silver carbonate and Chatton–Lwoff silver impregnation techniques. The result shows that the Qingdao population of this species possesses typical characteristics of the genus Pseudocohnilembus: the buccal apparatus consists of three highly specialized membranelles; membranelle 1 comprises a single row of kinetosomes, is parallel to membranelle 2, and lies anterior to the paroral membrane; membranelle 2 is longer than membranelle 1 and also comprises one row of kinetosomes; membranelle 3 is located near the middle of the paroral membrane and comprises three rows of kinetosomes. The silverline system is similar to that of P. persalinus. During stomatogenesis, the parental scutica proliferates and becomes the primordial field. This subsequently develops in two separate parts, the anterior part eventually disappears while the posterior part forms membranelle 3 of the opisthe. The secondary proliferated field, which derives from the zigzag configuration of parental paroral membrane, also develops in two parts, with the anterior becoming the paroral membrane and scutica of the opisthe and the posterior part developing into membranelles 1 and 2 of the opisthe. The remnants of the parental paroral membrane give rise to the paroral membrane and scutica of the proter.