bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlated evolution between hearing sensitivity and social calls in bats
Authors: Bohn Kirsten M , Moss Cynthia F , Wilkinson Gerald S
Published: June 2006

Echolocating bats are auditory specialists, with exquisite hearing that spans several octaves. In the ultrasonic range, bat audiograms typically show highest sensitivity in the spectral region of their species-specific echolocation calls. Well-developed hearing in the audible range has been commonly attributed to a need to detect sounds produced by prey. However, bat pups often emit isolation calls with low-frequency components that facilitate mother–young reunions. In this study, we examine whether low-frequency hearing in bats exhibits correlated evolution with (i) body size; (ii) high-frequency hearing sensitivity or (iii) pup isolation call frequency. Using published audiograms, we found that low-frequency hearing sensitivity is not dependent on body size but is related to high-frequency hearing. After controlling for high-frequency hearing, we found that low-frequency hearing exhibits correlated evolution with isolation call frequency. We infer that detection and discrimination of isolation calls have favoured enhanced low-frequency hearing because accurate parental investment is critical: bats have low reproductive rates, non-volant altricial young and must often identify their pups within large crèches.
Connecting the dots: an invariant migration corridor links the Holocene to the present
Authors: Berger Joel , Cain Steven L , Berger Kim Murray
Published: June 2006

Numerous species undergo impressive movements, but due to massive changes in land use, long distance migration in terrestrial vertebrates has become a highly fragile ecological phenomenon. Uncertainty about the locations of past migrations and the importance of current corridors hampers conservation planning. Using archeological data from historic kill sites and modern methods to track migration, we document an invariant, 150 km (one-way) migration corridor used for at least 6000 years by North America's sole extant endemic ungulate. Pronghorn (
Antilocapra americana
) from the Greater Yellowstone Ecosystem, like other long distant migrants including Serengeti wildebeest (
Connochaetes taurinus
) and Arctic caribou (
Rangifer tarandus
), move nearly 50 km d
−1
, but in contrast to these other species, rely on an invariant corridor averaging only 2 km wide. Because an entire population accesses a national park (Grand Teton) by passage through bottlenecks as narrow as 121 m, any blockage to movement will result in extirpation. Based on animation of real data coupled with the loss of six historic routes, alternative pathways throughout the 60 000 km
2
Yellowstone ecosystem are no longer available. Our findings have implications for developing strategies to protect long distance land migrations in Africa, Asia and North America and to prevent the disappearance of ecological phenomena that have operated for millennia.
Cues of being watched enhance cooperation in a real-world setting
Authors: Bateson Melissa , Nettle Daniel , Roberts Gilbert
Published: June 2006

We examined the effect of an image of a pair of eyes on contributions to an honesty box used to collect money for drinks in a university coffee room. People paid nearly three times as much for their drinks when eyes were displayed rather than a control image. This finding provides the first evidence from a naturalistic setting of the importance of cues of being watched, and hence reputational concerns, on human cooperative behaviour.
Exact solutions of the Laplace–Young equation
Authors: Anderson Michael L , Bassom Andrew P , Fowkes Neville
Published: June 2006

The solution of the Laplace–Young equation determines the equilibrium height of the free surface of a liquid contained in a vessel under the action of gravity and surface tension. There are only two non-trivial exact solutions known; one corresponds to a liquid occupying a semi-infinite domain bounded by a vertical plane wall while the other relates to the case when the liquid is constrained between parallel walls. A technique called
boundary tracing
is introduced; this procedure allows one to modify the geometry of the domain so that both the Laplace–Young equation continues to be satisfied while the necessary contact condition on the boundary remains fulfilled. In this way, new solutions of the equation are derived and such solutions can be found for certain boundaries with one or more sharp corners and for others that possess small-scale irregularities that can be thought of as a model for roughness. The method can be extended to construct new solutions for a variety of other physically significant partial differential equations.
Fatal attraction: living with earthquakes, the growth of villages into megacities, and earthquake vulnerability in the modern world
Authors: Jackson James
Published: June 2006

The great earthquake belt which stretches from the Mediterranean through the Middle East into Central Asia results from the ongoing collision between the Eurasian plate and the African, Arabian and Indian plates to the south. Through much of this belt, the topography is created and controlled by fault movement in earthquakes. Many habitations are located at the foot of the fault-controlled mountain range-fronts that bound inhospitable deserts or elevated plateaus, in positions that are favourable for trade-routes, strategic control of access or for water supply. As a result, they are vulnerable to earthquakes, which often seem to have targeted population centres precisely. For many centuries, an uneasy accommodation was reached between human needs and the earthquake-controlled landscape, sometimes brilliantly exploited by local hydrological engineering, as in Iran. Occasional earthquakes would occur, killing a shocking proportion of the population, but the populations of the settlements themselves would be relatively small. Many once-small rural communities have now grown into towns, cities or megacities, while retaining their vulnerability through poor building standards. Earthquakes that occur in these places today now kill many more than they did in the past, as we have witnessed in the last few years. Extreme catastrophes have been rare only because the exposure of modern megacities to earthquake hazards has been relatively short (approx. 50 years); an increase in the number of such catastrophes now seems to be inevitable.
Monitoring super-volcanoes: geophysical and geochemical signals at Yellowstone and other large caldera systems
Authors: Lowenstern Jacob B , Smith Robert B , Hill David P
Published: June 2006

Earth's largest calderas form as the ground collapses during immense volcanic eruptions, when hundreds to thousands of cubic kilometres of magma are explosively withdrawn from the Earth's crust over a period of days to weeks. Continuing long after such great eruptions, the resulting calderas often exhibit pronounced unrest, with frequent earthquakes, alternating uplift and subsidence of the ground, and considerable heat and mass flux. Because many active and extinct calderas show evidence for repetition of large eruptions, such systems demand detailed scientific study and monitoring. Two calderas in North America, Yellowstone (Wyoming) and Long Valley (California), are in areas of youthful tectonic complexity. Scientists strive to understand the signals generated when tectonic, volcanic and hydrothermal (hot ground water) processes intersect. One obstacle to accurate forecasting of large volcanic events is humanity's lack of familiarity with the signals leading up to the largest class of volcanic eruptions. Accordingly, it may be difficult to recognize the difference between smaller and larger eruptions. To prepare ourselves and society, scientists must scrutinize a spectrum of volcanic signals and assess the many factors contributing to unrest and toward diverse modes of eruption.
Natural convection in porous cylindrical annuli
Authors: Barbosa Mota J.P. , Saatdjian E.
Published: June 2006

Natural convection in a porous layer between two horizontal, concentric
cylinders is investigated numerically by solving the 2‐D
Darcy‐Boussinesq equations on a very fine grid. The
parabolic‐elliptic system was solved by a second order finite
difference scheme based on the implicit alternating direction method coupled
with successive under relaxation. The calculations show that for radius
ratios above 1.7, the functional relationship between the mean Nusselt number
and the Rayleigh number exhibits a closed hysteresis loop associated with the
transition from a two to a four cell flow pattern. For very small radius
ratios, steady state regimes containing 2, 4, 6, and 8 cells are
progressively obtained as the Rayleigh number is increased, but no hysteresis
behaviour is observed. For a radius ratio of 2, the numerical results are in
good agreement with the experimental data. Multi‐cellular regimes and
hysteresis loops have also been reported in the literature for fluid annuli
but some differences between the two cases exist and are fully explained
below.
Accurate animation of the thermo‐fluidic performance of the
pressure‐wave machine and its balanced material operation
Authors: Oberhem H. , Nour Eldin H.A.
Published: June 2006

Modelling, computation and performance animation of turbomachinery
systems has recently enjoyed remarkable attention in CAD research. This is
also reflected its application to exhaust machine components such as turbo
loaders and the exceptionally novel pressure wave machine (Comprex)
in the automobile industry and gas turbines. The necessity for the
thermo‐fluidic performance animation of such pressure wave machines
results from the fact that the machine geometry must be adapted to the
technical and thermo‐fluidic properties of the exhaust flow of the gas
turbine or automobile engine. Experimental adaptation or adjustment is
costly and should be validated for every application case. Thus the potential
to apply accurate animation for such shock‐tube like behaviour of
compressible flow is now economically promising with a view to optimizing the
design of the pressure wave machine. This paper presents briefly the problem
oriented algorithms used and illustrates the performance animation of the
pressure wave machine operating under constant speed drive. After introducing
the pressure wave machine operation, the principles and summary of the
algorithms used to compute the thermodynamic behaviour within the cell, the
boundary models and the accuracy of computation. A Comprex cycle operating on
an engine exhaust gas with T = 920°K, p = 2bar is
illustrated through 3‐dimensional representations for pressure, speed
of flow and temperature. The particle path (gas and air) together
with time representation of the state variables at different points of the
Compex will be shown. The mass balance problem is discussed and the conditions
for mass balanced flow for the gas as well as for the air side are given. The
results achieved for such materially balanced pressure wave machines indicate
a reduction in the costs for subsequent experimental validation and to
deliver the sound base for further development towards considering the
pre‐balanced transient operation cases as well.
Preconditioning convection dominated convection‐diffusion
problems
Authors: Goldstein C.I.
Published: June 2006

This paper is concerned with the numerical solution of
multi‐dimensional convection dominated convection‐diffusion
problems. These problems are characterized by a large parameter, K,
multiplying the convection terms. The goal of this work is the development
and analysis of effective preconditioners for iteratively solving the large
system of linear equations arising from various finite element and finite
difference discretizations with grid size h. When centered finite
difference schemes and standard Galerkin finite element methods are used,
h must be related to K by the stability constraint, Kh ≤
C0, where the constant C0 is sufficiently small. A class of
preconditioners is developed that significantly reduces the condition number
for large K and small h. Furthermore, these preconditioners are
inexpensive to implement and well suited for parallel computation. It is
shown that under suitable assumptions, the number of iterations remains
bounded as h ↓0 with K fixed and, at worst, grows slowly as K
↓ ∞. Numerical results are presented illustrating the theory. It
is also shown how to apply the theoretical results to more general
convection‐diffusion problems and alternative discretizations
(including streamline diffusion methods) that remain stable as Kh
↓ ∞.
Use of baffles in cavity flow for the suppression of thermal
oscillations under microgravity
Authors: Ho Mary C. , Ramaswamy B.
Published: June 2006

The quality of crystals grown from melt depends on the flow field in the
melt. To simulate melt conditions, a finite element analysis is performed on
flow in a heated cavity under the driving forces of natural convection,
thermocapillary effects and rotation. In addition, the gravity field is
modulated to simulate a microgravitational environment. The purpose for
conducting this research is to determine whether the use of baffles can
effectively reduce convection and suppress temperature oscillations. The
results show that the baffle is able to suppress convection and reduce the
amplitude of the temperature oscillations when placed perpendicular to the
modulation direction. Under crystal and crucible rotation, the results with
and without baffles are similar. In all cases, baffles did not induce
temperature oscillations. From this study, it can be concluded that the
effects of baffles on the flow behaviour depends greatly on the direction of
gravity modulation and frequency.
Numerical study of enhanced oil recovery using surfactants
Authors: Chatterjee A. , Muralidhar K.
Published: June 2006

The analysis of enhanced oil recovery using surfactants is presented
here. Surfactants lower the surface tension between oil and water and hence
the capillary resistance to flow. The mathematical description of this
problem requires modelling of multi‐phase flow in a porous medium. A
pressure‐based formulation has been used in the present study. The
governing partial differential equations have been solved by a finite
difference method. Both Newtonian and non‐Newtonian (shear
thinning) behaviour of oil are considered. Results clearly show an
improvement in oil recovery in the presence of surfactants. A study of the
ideal case where surface tension is reduced to zero shows that oil recovery
can be very high.
Implicit modified enthalpy method with application to thin film
melting
Authors: Hess Christopher K. , Miaoulis Ioannis N.
Published: June 2006

During the thermal processing of thin films in which low intensity line
heat sources are used, extended processing times are often required to reach
steady state (˜15 sec). In addition, the melting of the film
may occur some time after processing has begun, and therefore there is no
initial melting condition within the film. In such cases, computer
simulations may become very time consuming, and the development of an
efficient computational method which incorporates the initial formation of
the melt during processing is necessary. A general technique was developed to
accurately model two‐dimensional heat conduction in a multilayer film
structure with one‐dimensional phase change in one of the thin films.
These conditions frequently exist in thin film thermal processing when the
thermal gradient through the thickness of the melting film can be considered
negligible. The method involves an implicit formulation of the modified
enthalpy method. The solid/liquid interface energy‐balance
equation is taken into account which allows the exact location of the
interface to be tracked within a control volume. A comparison is made between
the explicit and implicit modified methods to test efficiency and accuracy.
The implicit method is then applied to the zone‐melting
recrystallization of a silicon thin film in a multilayer
structure.
A direct numerical simulation of transition in mixed convection flows between two heated parallel plates
Authors: Hao C.C. , Chung J.N.
Published: June 2006

This paper seeks to increase our understanding on the fluid mechanics
and heat transfer in a transitional mixed convection flow between two
vertical plates. Direct numerical simulation by the spectral method, with a
weak formulation, is used to solve the transient 3–D
Navier‐Stokes equations and energy equation. Initial disturbances
consist of the finite‐amplitude 2–D Tollmien‐Schlichting
wave and two 3–D oblique waves. The transition phenomena in a
mixed‐convection flow can be significantly different from the
isothermal flow. Disturbance competitions among different modes are also
found to be different from those known for an isothermal flow. In a
mixed‐convection flow, there exist thresholds for the low‐mode
Fourier waves. The intensified vortices are concentrated left of the central
surface between the two plates. Hairpin vortices are formed with high
Ri. Based on the flow visualization, the λ vortices are found to be staggered on the surfaces parallel to the plates. The Ri number seems to be the main parameter governing the transition mechanism. The Nu number is found to increase during transition.
A numerical optimization procedure for complex pipe and duct network
design
Authors: Mathews E.H. , Köhler P.A.J.
Published: June 2006

The design of optimum pipe and duct networks with available procedures
is difficult, if not impossible. A more efficient procedure that will
automatically produce the optimum design is required. Such a procedure is
presented in this article. The design is formulated as a constrained
nonlinear optimization problem. This problem is solved using a unique
numerical optimization algorithm. The solution entails the calculation of the
cross sectional dimensions of the ducts and pipes so that the life cycle cost
of the network is minimized. The topology equations are derived using graph
theory thereby allowing complex networks with loops to be designed
numerically. A duct network consisting of a fan and 35 duct sections is
designed according to certain specifications. Using the proposed procedure
optimum designs were obtained within seconds on a 33 MHz 486
micro‐computer. The procedure was further applied to the optimization
of a coal pipeline. It is shown that the optimized solution will cost
14% ($8 million) less than the previous design with
conventional design techniques.
Numerical laminar and turbulent fluid flow and heat transfer predictions
in tube banks
Authors: Zdravistch Franz , Fletcher Clive A. , Behnia Masud
Published: June 2006

Numerical predictions of laminar and turbulent fluid flow and heat
transfer around staggered and in‐line tube banks are shown to agree closely
with seven experimental test cases. The steady state Reynolds‐averaged
Navier‐Stokes equations are discretised by means of a cell‐centred
finite‐volume algorithm. Two‐dimensional results include velocity vectors and
streamlines, surface shear stresses, pressure coefficient distributions,
temperature contours, local Nusselt number distributions and average
convective heat transfer coefficients, and indicate very good agreement with
experimental data. It is found that a relatively fine grid is required to be
able to predict the surface heat transfer behaviour accurately. Also,
three‐dimensional simulations are shown, which are physically consistent. The
numerical procedure presented here is robust, accurate and time efficient,
making it suitable as a design tool for tube banks in heat
exchangers.
A fractional step method for mass transport in groundwater
Authors: Demetriou C. , Volker R.E. , Johnston A.J.
Published: June 2006

A computer model based on the fractional step method is presented for
modelling density coupled mass transport in groundwater. Although several
models utilising the fractional step method had been developed previously,
all were based on the Eulerian solution approach. The model developed by the
authors uses the Langrangian approach which has some inherent advantages and
disadvantages. The problems associated with the implementation of the
fractional step method and techniques by which they were overcome are
discussed. The performance of the model is examined and results obtained for
standard problems are compared with those from other computer
packages.
Electrothermal simulation of power vdmos transistors
Authors: Mawby P.A. , Zeng J. , Board K.
Published: June 2006

Poisson’s equation and the electron continuity equation, together with
heat flow equation are solved self‐consistently to obtain the lattice
temperature profile under non‐isothermal conditions in a power VDMOS
transistor. The effect of the variable lattice temperature on the forward
characteristics of VDMOSTs is presented, and discussed. The results show that
self‐heating in power VDMOSTs has a significant effect. The thermal
coupling effects on the forward I—V characteristics are compared and
discussed between the power VDMOST and the conventional MOSFET.
Numerical experiments on laminar natural convection in rectangular
cavities with and without honeycomb‐structures
Authors: Schweiger H. , Oliva A. , Costa M. , Pérez Segarra C.D. , Ivancić A.
Published: June 2006

Two‐dimensional finite difference calculations are carried out to
study laminar flow in longitudinal and transverse convection rolls for three
different geometries: a single rectangular cavity with high aspect ratio; a
double cavity with a thin separation sheet; and a double cavity with a
separation sheet and a honeycomb structure. The equations for the
convection‐diffusion in the fluid and conduction in the solid region
are solved simultaneously. Good agreement with experimental data is achieved
for Rayleigh numbers not too high above the critical value for the onset of
secondary convection rolls (Ra < 8500 for vertical and
Ra < 2700 for horizontal cavities filled with air).
Simulation fails for inclined cavities, where the flow structure is
essentially three‐dimensional.
Distinction between Mulloidichthys flavolineatus juveniles from Reunion Island and Mauritius Island (south‐west Indian Ocean) based on otolith morphometrics
Authors: Pothin K. , Gonzalez‐Salas C. , Chabanet P. , Lecomte‐Finiger R.
Published: June 2006

Sagittal otoliths of the yellowstripe goatfish Mulloidichthys flavolineatus were analysed in order to compare Reunion Island fish stocks with those of Mauritius (south‐west Indian Ocean). Conventional otolith morphometric variables (area, perimeter, length and width), shape indices (form factor, roundness, circularity, rectangularity, ellipticity and eccentricity) and Fourier shape analysis were compared between three sites; two in Reunion Island and one in Mauritius. Regional and site‐specific differences were found for all the conventional otolith morphometric features. Regarding the shape indices, the differences between sites were best described by form factor, roundness, circularity and rectangularity. A classification by canonical discriminant analysis indicated significant differences between the three sampling sites. The combined use of morphometric variables (size and shape) and external outlines (shape analysis through Fourier series) showed the importance of otolith shape for intraspecific discrimination.
Spectral sensitivity of mollies: comparing surface‐ and cave‐dwelling Atlantic mollies,Poecilia mexicana
Authors: Körner K. E. , Schlupp I. , Plath M. , Loew E. R.
Published: June 2006

The visual pigments of cones and rods in three species of mollies,Poecilia mexicana,Poecilia latipinnaand their asexual hybridPoecilia formosa, were examined using microspectrophotometry. InP. mexicana, populations from extreme photic habitats were used: one population originated from a clear water habitat, one from a milky water habitat and another from a completely dark cave. Ultraviolet‐sensitive cones were found in all species. Differences in the λmaxvalues of the visual pigments were small between species and among the threeP. mexicanapopulations, but dark‐reared cave fishes showed appreciably higher variance. The hybrid speciesP. formosashowed a highly variable long wavelength cone absorbance, ranging from 528·9 to 598·5 nm, suggesting multiple opsin expression or chromophore mixing.
Dose‐dependent effects of developmental mercury exposure on C‐start escape responses of larval zebrafishDanio rerio
Authors: Weber D. N.
Published: June 2006

ZebrafishDanio rerioembryos were exposed to 0, 25, 50 or 75 ppb Hg2+from 0 to 24 h post‐fertilization (hpf) then placed into Hg2+‐free water. Inductively coupled plasma‐mass spectrophotometer analysis of whole embryo Hg2+content at 24 hpf showed a positive correlation with exposure regime (Pearson's one‐tailed,r2= 0·698,P< 0·01); at 5 days post‐hatch (dph), whole larval Hg2+content was not detectable. Hg2+‐induced behavioural deficits in larvae were, therefore, due to changes during embryogenesis and not to residual Hg2+in the larvae. At 5 dph, larvae were tested for responses to different frequencies but equal intensities of vibrational stimuli generated by a remotely controlled plastic hammer. Data were recorded by high‐speed videography and computer‐analysed for latency of response (ms), amplitude of the response as measured by maximum initial velocity [normalized as body (standard) lengths s−1;Vmax] and duration of behaviour from initial head movement to cessation of caudal tail movement (ms). A single mechanical stimulus resulted in behavioural outcomes that were related to embryonic Hg2+uptake. Response latency increased with exposure level and displayed an increase of ×1·5–2·5 over control values (ANOVA,P< 0·01). TheVmaxdecreased with exposure level to a low of 71% of control at the highest Hg2+concentration (ANOVA,P< 0·01). Duration of behaviour displayed a biphasic response pattern in which exposure to 0, 50 or 75 ppb Hg2+did not result in a significantly different response yet exposure to 25 ppb Hg2+caused a significantly longer time of active response (ANOVA,P< 0·01). Repeated stimulation (1, 2 or 4 hits s−1) resulted in a concentration‐dependent increase in response failures. Regardless of stimulation frequency, larvae exposed to 0 or 25 ppb Hg2+as embryos maintained higherVmaxlevels for longer intervals during the testing period than those exposed as embryos to either 50 or 75 ppb Hg2+.
Influence of salinity on the size at maturity for fish species reproducing in contrasting West African estuaries
Authors: Panfili J. , Thior D. , Ecoutin J.‐M. , Ndiaye P. , Albaret J.‐J.
Published: June 2006

The influence of salinity on life‐history traits was tested using two adjoining West African estuaries: the Gambia with a ‘normal’ salinity gradient (salinity always <40 and decreasing from the mouth upstream) and the Sine Saloum (Senegal) with an inverse gradient (from 35 at the estuary mouth up to >130 in the upper reaches). The breeding seasons and subsequent fork length (LF) at first maturity (LF50) were estimated for different fish species reproducing both in the Sine Saloum and in the Gambia River estuaries using a database built from experimental fish samplings between 1990 and 2003 with a purse seine (30 locations in the Sine Saloum and 44 in the Gambia). The database contained 30 553 individuals belonging to 60 different species among which only 20 species reproduced in both estuaries. The breeding seasons peaked just before, or at the beginning of the rainy season (June to July), and there were almost no sexually mature fishes at the beginning of the dry season (November to December). Patterns of differences between LF50 of the two estuaries did not follow a general trend (positive or negative), but varied in the same way for females and males of a given species. The LF50 was only systematically reduced with increasing salinity in species living in high‐salinity waters (>70). For species living below 70, differences in sizes at first maturity between the two estuaries did not show any clear relationship with salinity. The smallest mature individual found in an environment was a good indicator of the size at first maturity reached in a particular ecosystem because the trend of the species differences between the two ecosystems generally followed that of the differences in size at maturity.
Prespawning stress in farmed Atlantic salmonSalmo salar: maternal cortisol exposure and hyperthermia during embryonic development affect offspring survival, growth and incidence of malformations
Authors: Eriksen M. S. , Bakken M. , Espmark Å. , Braastad B. O. , Salte R.
Published: June 2006

In the current study, mature female Atlantic salmonSalmo salarwere given intraperitoneal cortisol implants with the purpose of elucidating potentially detrimental effects on offspring survival, growth, morphological development and also the ability of prenatally stressed offspring to cope with an environmental stressor, typified by a period of mild hyperthermia. Augmented levels of maternal cortisol inflicted a range of progeny somatic parameters, as reflected in increased mortality, reduced fork length and mass, diminished yolk‐sac volume, decelerated yolk‐sac utilization and, to some extent, enhanced prevalence of morphological malformations. The most pronounced consequences on offspring performance were demonstrated in specimens exposed to both enhanced prenatal cortisol and a subsequent episode of hyperthermia. This accentuates the importance of knowledge on how the maternal endocrinological state during gametogenesis may impinge on offspring characters in farmed Atlantic salmon, and further substantiates the necessity of incorporating maternal effects when evaluating rearing conditions and animal welfare in commercial aquaculture.
The effect of small‐scale resource origin on trophic position estimates in Perca fluviatilis
Authors: Quevedo M. , Olsson J.
Published: June 2006

The influence of small‐scale differences in resource origin on trophic position estimates was evaluated with the stable isotopes method. Perch Perca fluviatilis, a widespread freshwater predator, was used as a model organism. High individual variability was found in the contribution of benthic resources to the isotopic signatures of perch caught in the littoral zone, suggesting substantial within‐habitat individual specialization. Small‐scale resource origin and δ13C enrichment should be accounted for to avoid misleading estimates of both the absolute values and the ontogenetic trajectories of trophic position. A conceptual framework using end‐member pathways is proposed to estimate trophic position with the stable isotope technique, particularly when marked ontogenetic niche shifts are expected.
Digestive enzymes along the alimentary tract of the parrotfish Sparisoma cretense
Authors: Papoutsoglou E. S. , Lyndon A. R.
Published: June 2006

The digestive enzyme profile (total protease, total carbohydrase, alpha‐amylase and alpha‐glucosidase activity and capacity) along the digestive tract was investigated in vitro at different temperature levels (5, 18, 25 and 37° C) for the only Mediterranean species of parrotfish Sparisoma cretense. Sparisoma cretense (collected from the wild from south‐eastern Greece) exhibited very high potential for carbohydrate digestion, as well as relatively increased potential for protein digestion. Total protease activity and capacity was increased especially at neutral and alkaline pH levels and was similar in the anterior and posterior intestine. Total carbohydrase, alpha‐amylase and alpha‐glucosidase values were quite elevated at 37° C but relatively low at 5, 18 and 25° C. Total carbohydrase and alpha‐amylase capacity in the posterior intestine became increasingly important with elevated temperature, while the opposite was apparent for α‐glucosidase. These results suggest that, apart from the expected high potential for carbohydrate digestion exhibited, S. cretense also has the elevated capacity for protein digestion, although it lacks a specialized stomach and pyloric caeca.
Migration success and migration time of gastrically radio‐tagged v. PIT‐tagged adult Atlantic salmon
Authors: Rivinoja P. , Leonardsson K. , Lundqvist H.
Published: June 2006

Adult Atlantic salmon (55–116 cm total length) with PIT‐tags (n= 318) and both PIT‐tags and gastric radio‐tags (n= 127) in a regulated river showed similar upstream migration success, yet radio‐tagged fish migrated faster than fish with only PIT‐tags. Regurgitation rate of radio‐tags was 9%.
Cytochemical method for staining fish basophils
Authors: Tavares‐Dias M.
Published: June 2006

The occurrence of basophils in peripheral blood of 15 freshwater teleosts was examined using the metachromatic stain, toluidine blue, on blood smears fixed with lead subacetate. Metachromasia was more identifiable through better preservation of the granules. The occurrence of basophils in teleost blood was confirmed as very rare and was not caused by failure to preserve the basophil granules.
Longitudinal changes and indicator species of the fish fauna in the subtropical Sinos River, Brazil
Authors: Petry A. C. , Schulz U. H.
Published: June 2006

This study investigated the fish fauna in the subtropical Sinos River, considering species addition and replacement and the occurrence of indicator species along a longitudinal gradient. Patterns in fish assemblage ordination evaluated by correspondence analysis reflected the headwater and lowland river reaches. Uppermost sampling stations were characterized by species with restricted occurrence and medium abundance, whereas in the lowland most species were captured only once during the surveyed period and in low abundance. Species addition prevailed between the headwater sampling stations and both addition and replacement occurred between the lowland sampling stations. Nine species were characteristic for the headwater reach and 14 species for the lowland reach.
The evolution of reproductive and genomic diversity in ray‐finned fishes: insights from phylogeny and comparative analysis
Authors: Mank J. E. , Avise J. C.
Published: June 2006

Collectively, ray‐finned fishes (Actinopterygii) display far more diversity in many reproductive and genomic features than any other major vertebrate group. Recent large‐scale comparative phylogenetic analyses have begun to reveal the evolutionary patterns and putative causes for much of this diversity. Several such recent studies have offered clues to how different reproductive syndromes evolved in these fishes, as well as possible physiological and genomic triggers. In many cases, repeated independent origins of complex reproductive strategies have been uncovered, probably reflecting convergent selection operating on common suites of underlying genes and hormonal controls. For example, phylogenetic analyses have uncovered multiple origins and predominant transitional pathways in the evolution of alternative male reproductive tactics, modes of parental care and mechanisms of sex determination. They have also shown that sexual selection in these fishes is repeatedly associated with particular reproductive strategies. Collectively, studies on reproductive and genomic diversity across the Actinopterygii illustrate both the strengths and the limitations of comparative phylogenetic approaches on large taxonomic scales.
Early stages of Ascaris suum induce airway inflammation and hyperreactivity in a mouse model
Authors: ENOBE C. S. , ARAÚJO C. A. , PERINI A. , MARTINS M. A. , MACEDO M. S. , MACEDO‐SOARES M. F.
Published: June 2006

The inflammatory and functional changes that occur in murine lung after infection with 2500 infective Ascaris suum eggs were studied in this work. A sequential influx of neutrophils, mononuclear cells and eosinophils occurred into airways concomitantly with migration of larvae from liver to the lungs. Histological analysis of the lung showed a severe intra‐alveolar haemorrhage at the peak of larval migration (day 8) and the most intense inflammatory cell infiltrate on day 14. Ascaris L3 were found in alveolar spaces and inside bronchioles on day 8. The number of eosinophils was elevated in the blood on days 8 and 14. The peak of eosinophil influx into the lung was at day 14, as indicated by the high levels of eosinophil peroxidase activity, followed by their migration into the airways. The antibody response against egg and larval antigens consisted mainly of IgG1 and IgM, and also of IgE and anaphylactic IgG1, that cross‐reacted with adult worm antigens. Total IgE levels were substantially elevated during the infection. Measurement of lung mechanical parameters showed airway hyperreactivity in infected mice. In conclusion, the murine model of A. suum infection mimics the Th2‐induced parameters observed in pigs and humans and can be used to analyse the immunoregulatory properties of this helminth.
Molecular basis of worm‐induced immunomodulation
Authors: HARNETT W. , HARNETT M. M.
Published: June 2006

Long‐term infection with parasitic worms is generally associated with an immunological phenotype that is Th2‐like and anti‐inflammatory. This phenotype is probably an unintentional consequence of molecular characteristics of worms (as free‐living worms also express polarising molecules) in combination with deliberate attempts by the parasites, via molecular secretions, to modulate the phenotype. This review is concerned with the identity of immunomodulatory worm products, the receptors that they interact with and the signal transduction pathways that they activate. It hopes to indicate how knowledge of these factors can explain the changes in gene expression that result in the characteristic worm‐induced immunological phenotype.
Diagnosis and treatment of atopic dermatitis in children and adults: European Academy of Allergology and Clinical Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL Consensus Report
Authors: Akdis C. A. , Akdis M. , Bieber T. , Bindslev‐Jensen C. , Boguniewicz M. , Eigenmann P. , Hamid Q. , Kapp A. , Leung D. Y. M. , Lipozencic J. , Luger T. A. , Muraro A. , Novak N. , Platts‐Mills T. A. E. , Rosenwasser L. , Scheynius A. , Simons F. E. R. , Spergel J. , Turjanmaa K. , Wahn U. , Weidinger S. , Werfel T. , Zuberbier T. ,   the European Academy of Allergology and Clinical Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL Consensus Group
Published: June 2006

There are remarkable differences in the diagnostic and therapeutic management of atopic dermatitis practiced by dermatologists and pediatricians in different countries. Therefore, the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma and Immunology nominated expert teams who were given the task of finding a consensus to serve as a guideline for clinical practice in Europe as well as in North America. The consensus report is part of the PRACTALL initiative, which is endorsed by both academies.
A new method for non‐invasive, manoeuvre‐free determination of “static” pressure–volume curves during dynamic/therapeutic mechanical ventilation
Authors: Kárason S. , Søndergaard S. , Lundin S. , Wiklund J. , Stenqvist O.
Published: June 2006

Background: Lung mechanics are usually measured using static or quasistatic methods, abandoning normal ventilatory treatment. We have developed a method to calculate the alveolar pressure during dynamic/therapeutic conditions, “the dynostatic pressure” (Pdyn), using airway pressure (P) measured in the trachea and volume (V) and flow (V˙) at the Y‐piece.

Methods: Pdyn is calculated according to the formula Pdyn=(Pinsp×V˙exp–Pexp×V˙insp)/(V˙exp–V˙insp), making the assumption that inspiratory and expiratory resistances are equal at isovolume. The method was evaluated in a lung model during dynamic conditions comparing measured alveolar pressure (Palv) and Pdyn at equal and unequal inspiratory and expiratory resistances and P/V‐curves obtained during static and dynamic conditions. The algorithm was then applied in patients with acute lung injury (ALI).

Results: When inspiratory and expiratory resistances were equal there was an excellent agreement between the Pdyn and the Palv, irrespective of ventilator settings, r2=0.995 (range 0.981–0.999). Pdyn derived compliance was equal to static values. When the ratio between inspiratory and expiratory resistance was varied between 2.3:1 and 1:2.3 the r2 was above 0.95 (range 0.952–0.996). Development of intrinsic PEEP and overdistension was easily revealed in patients, as shown by the dynostatic P/V‐curve.

Conclusion: The dynostatic method gives a breath‐by‐breath reflection of the interaction between ventilatory settings and lung mechanics in patients during ordinary ventilator treatment. It is only marginally affected by the moderate differences in inspiratory versus expiratory resistances present in patients with ALI.
Development of permanent national register of blood component use utilizing electronic hospital information systems
Authors: Palo R. , Ali‐Melkkilä T. , Hanhela R. , Jäntti V. , Krusius T. , Leppänen E. , Mahlamäki E. K. , Perhoniemi V. , Rajamäki A. , Rautonen J. , Salmenperä M. , Salo H. , Salonen I. , Savolainen E‐R. , Sjövall S. , Suistomaa M. , Syrjälä M. , Tienhaara A. , Vähämurto M. , Mäki T.
Published: June 2006

Background and Objectives  We wanted to establish a permanent national database system, which can be utilized to study transfusion recipients and blood use in Finland.

Materials and Methods  A regularly updated register for permanent use was developed. To study the usability of the database, years 2002 and 2003 were further analysed. Database included all transfused patients in major blood‐transfusing hospitals from four university and five central hospital districts managing altogether 63% of Finnish inpatient hospital episodes.

Results  Audit of gathered data reveal 96·8% match in adult blood components with Finnish Red Cross, Blood Service sales figures. Model data set includes 59 535 transfused patients (44·3% men and 55·7% women) having received 529 104 blood components. Half of all blood units were transfused in connection with surgical operations. Most of the blood recipients were elderly (51·6% are over 64 years of age). Blood‐component use and transfusion‐related costs varied widely between hospitals.

Conclusion  Hospital data managing systems can be useful for creating a population‐based database system to monitor and compare transfusion practices. This record provides information about transfusion epidemiology for transfusion professionals, hospital management, and hospital administration.
Reducing admission times in the endoscopy unit
Authors: Dobree‐Carey Deborah , Gorard David A
Published: June 2006

Pre‐procedural admission of outpatients to a day‐case endoscopy facility is time‐consuming. Collecting and recording routine but necessary information distracts nurses from spending time that could be used to counsel patients. This study assessed whether patients can record some pre‐procedural details and whether such self‐recording quickens nurse admission times. A new admission document was devised and posted to patients. Patients completed personal/administrative details and information about drugs and allergies and brought the document with them when attending for outpatient endoscopy. Endoscopy nurses anonymously timed 100 admissions, 50 using the new admission form and 50 using the old admission form. Overall, the median (range) time to admit using the old form was 6 (3–15.5) min. Using the new form, the median time to admit was lower at 4 (0.5–10) min. No patient completing the new form reported any particular difficulties. An admission document that patients partially complete at home leads to a faster pre‐procedural admission in the endoscopy unit. This allows more nursing time to discuss patients’ anxieties and answer patient queries, helps to prevent delays and facilitates increased capacity in the endoscopy unit.
Analysis of the impact of a national initiative to promote evidence‐based nursing practice
Authors: Ring Nicola , Coull Alison , Howie Catherine , Murphy‐Black Tricia , Watterson Andrew
Published: June 2006

Best Practice Statements (BPS) are designed to facilitate evidence‐based practice. This descriptive, exploratory study evaluated the impact of five of these statements in Scotland. A postal survey of 1278 registered nurses was undertaken to determine use of these statements and their perceived benefits (response rate: 42%). Use of the BPS differed across clinical sites and some statements were more likely to be used than others. Identified barriers and drivers to their use were similar to factors known to encourage or hinder evidence‐based practice generally. Although ≈ 25% of clinical respondents reported using the BPS, most respondents reported perceived benefits to patients usually through quality improvement. Results highlight the importance of facilitation and supportive contexts in encouraging clinical use of these statements. Findings suggest that variation in clinical implementation of the BPS need to be addressed locally and nationally if their benefits are to be maximized.
Defining the scope of practice of the emergency nurse practitioner role in a metropolitan emergency department
Authors: Considine Julie , Martin Roslyn , Smit DeVilliers , Jenkins Jane , Winter Craig
Published: June 2006

This study examined the emergency nurse practitioner candidate (ENPC) scope of practice in a Victorian emergency department (ED). The emergency nurse practitioner (ENP) role is relatively new in Victoria and the scope of the ENP(C) practice is yet to be defined. International research literature regarding the ENP role has focused on outcomes such as patient satisfaction, waiting times and/or ED length of stay, accuracy and adequacy of documentation, use of radiography, and patient education, health promotion and communication issues. A prospective exploratory design was used to conduct this cohort study. There were 476 ENPC‐managed patients between 14 July 2004 and 31 March 2005 with an average age of 29 years. The majority (77.2%) of ENPC‐managed patients were discharged from the ED. The majority of the ENPC time was devoted to clinical practice (55%) and development of clinical practice guidelines (25%). Of patients managed by the ENPC, 49.6% required medications, 51% required diagnostic imaging and 8.6% required pathology testing during their ED stay. The most common discharge referrals were made to local medical officers (73.5%) and the most common referrals made for patients requiring admission were made to the plastic surgery (37.3%) and orthopaedic (35.5%) units. Extensions to the current scope of emergency nursing practice are pivotal to effective management of specific patient groups by ENP. The ENP model of care is an important strategy for the management of increased service demands in Victoria; however, little is known about the scope of the ENPC practice and many outcomes of the ENP care are yet to be defined. Further research to better understand the relationships between ENP outcomes is required if the contribution that ENPs make to emergency care is to be accurately quantified.
Workplace violence in Queensland, Australia: The results of a comparative study
Authors: Hegney Desley , Eley Robert , Plank Ashley , Buikstra Elizabeth , Parker Victoria
Published: June 2006

This paper presents the results on workplace violence from a larger study undertaken in 2004. Comparison is made with the results of a similar study undertaken in 2001. The study involved the random sampling of 3000 nurses from the Queensland Nurses’ Union’s membership in the public (acute hospital and community nursing), private (acute hospital and domiciliary nursing) and aged care (both public and private aged care facilities) sectors. The self‐reported results suggest an increase in workplace violence in all three sectors. Although there are differences in the sources of workplace violence across the sectors, the major causes of workplace violence are: clients/patients, visitors/relatives, other nurses, nursing management and medical practitioners. Associations were also found between workplace violence and gender, the designation of the nurse, hours of employment, the age of the nurse, morale and perceptions of workplace safety. Although the majority of nurses reported that policies were in place for the management of workplace violence, these policies were not always adequate.