bluuebunny/crossref_metadata_2025 huggingface dataset:
Drift–diffusion in mangled worlds quantum mechanics
Authors: Hanson Robin D
Published: February 2006

In Everett's many-worlds interpretation, where quantum measurements are seen as decoherence events, inexact decoherence may let large worlds mangle the memories of observers in small worlds, creating a cutoff in observable world measure. I solve a growth–drift–diffusion–absorption model of such a mangled worlds scenario, and show that it reproduces the Born probability rule closely, though not exactly. Thus, inexact decoherence may allow the Born rule to be derived in a many-worlds approach via world counting, using a finite number of worlds and no new fundamental physics.
Measure valued solutions to conservation laws motivated by traffic modelling
Authors: Benzoni-Gavage Sylvie , Colombo Rinaldo M , Gwiazda Piotr
Published: February 2006

Motivated by a traffic model, we study a conservation law whose solutions naturally need to be bounded Radon measures. We investigate the relations between this equation and finite systems of conservation laws that converge to it.
Implications of superstrong non-locality for cryptography
Authors: Buhrman Harry , Christandl Matthias , Unger Falk , Wehner Stephanie , Winter Andreas
Published: February 2006

Non-local boxes are hypothetical ‘machines’ that give rise to superstrong non-local correlations, leading to a stronger violation of Bell/Clauser, Horne, Shimony & Holt inequalities than is possible within the framework of quantum mechanics. We show how non-local boxes can be used to perform any two-party secure computation. We first construct a protocol for bit commitment and then show how to achieve oblivious transfer using non-local boxes. Both have been shown to be impossible using quantum mechanics alone.
Finkelstein–Rubinstein constraints for the Skyrme model with pion masses
Authors: Krusch Steffen
Published: February 2006

The Skyrme model is a classical field theory modelling the strong interaction between atomic nuclei. It has to be quantized in order to compare it to nuclear physics. When the Skyrme model is semi-classically quantized it is important to take the Finkelstein–Rubinstein constraints into account. Recently, a simple formula has been derived to calculate the constraints for Skyrmions which are well approximated by rational maps. However, if a pion mass term is included in the model, Skyrmions of sufficiently large baryon number are no longer well approximated by the rational map ansatz. This paper addresses the question how to calculate Finkelstein–Rubinstein constraints for Skyrme configurations which are only known numerically.
Enhancement of mass transport and separation of species by oscillatory electroosmotic flows
Authors: Huang Hsin-Fu , Lai Chun-Liang
Published: February 2006

Mass transport driven by oscillatory electroosmotic flows (EOF) in a two-dimensional micro-channel is studied theoretically. The results indicate that the velocity and concentration distributions across the channel-width become more and more non-uniform as the Womersley number
W
, or the oscillation frequency, increases. It is also revealed that, with a constant tidal displacement, the total mass transport rate increases with the Womersley number
W
due to both the stronger convective and the transverse dispersion effects. The total mass transport rate also increases with the tidal displacement (with a fixed oscillation frequency) because of the associated stronger convective effects. The cross-over phenomenon of the mass transport rates for different species becomes possible with sufficiently large Debye lengths and at sufficiently large values of
W
. Consequently, with proper choices of the Debye length, oscillation frequency and tidal displacement, oscillatory EOF may become a good candidate for the first-step separation of the mass species.
Transverse instabilities of deep-water solitary waves
Authors: Deconinck Bernard , Pelinovsky Dmitry E , Carter John D
Published: February 2006

The dynamics of a one-dimensional slowly modulated, nearly monochromatic localized wave train in deep water is described by a one-dimensional soliton solution of a two-dimensional nonlinear Schrödinger (NLS) equation. In this paper, the instability of such a wave train with respect to transverse perturbations is examined numerically in the context of the NLS equation, using Hill's method. A variety of instabilities are obtained and discussed. Among these, we show that the solitary wave is susceptible to an oscillatory instability (complex growth rate) due to perturbations with arbitrarily short wavelength. Further, there is a cut-off on the instability with real growth rates. We show analytically that the nature of this cut-off is different from what is claimed in previous works.
A nonlinear model of the dynamics of a large elastic plate with heavy fluid loading
Authors: Peake N , Sorokin S.V
Published: February 2006

In this paper, we derive weakly nonlinear equations for the dynamics of a thin elastic plate of large extent under conditions of heavy fluid loading. Two situations are then considered. First, we consider the case in which transverse motion of the plate generates a weaker in-plane motion, which is in turn coupled back to the evolution of the transverse motion. This results in the familiar nonlinear Schrödinger equation for the amplitude of a transverse plane wave, and we show that solitary-wave solutions are possible over the range of (non-dimensional) frequencies
ω
>
ω
c
, which depends on the material properties. Dimensional values of
ω
c
are physically realizable for a typical composite material underwater. Second, we consider the case in which the amplitudes of the transverse and in-plane motion are of the same order of magnitude, possible at a single resonant frequency, which leads to an evolution equation of rather novel type. We find a range of travelling-wave solutions, including cases in which incident in-plane waves can generate localized regions of transverse displacement.
Convergence of taboo search in continuous global optimization
Authors: Ji Mingjun , Klinowski Jacek
Published: February 2006

While taboo search (TS), a method of global optimization, has successfully solved many optimization problems, little is known about its convergence properties, especially for continuous optimization tasks. We consider the global convergence of the original TS for solving continuous optimization problems, and give a condition which guarantees the convergence of the objective value sequence of the method. We also prove that the minimum objective value sequence converges to the vicinity of the global optimal value with probability 1.
A general method for coupling microstructural response with structural performance
Authors: Das Sumitesh , Shterenlikht Anton , Howard Ian C , Palmiere Eric J
Published: February 2006

The paper sets out the general principles of a method of coupling finite element for the representation of the structural response with array of cellular automata to encompass the associated microstructural behaviour. For the purpose of this paper, cellular automata is a discrete time–discrete space system consisting of cells which may take one of several states. The state of a cell depends on the states of the neighbouring cells as well as on some macroscopic field variables. The paper goes on to show how these principles can be used, by applying them to problems of oxide scale cracking and of dynamic recrystallization during the hot working of steel, and to the ductile-to-brittle transition in the fracture of ferritic steels.
The evolution of parental care and egg size: a comparative analysis in frogs
Authors: Summers Kyle , Sea McKeon Christian , Heying Heather
Published: February 2006

The evolution of parental care and egg size has attracted considerable attention and theoretical debate. Several different hypotheses have been proposed concerning the trajectories of parental care and egg size evolution and the order of specific evolutionary transitions. Few comparative studies have investigated the predictions of these hypotheses. Here, we investigate the evolutionary association between parental care and egg size in frogs in a phylogenetic context. Data on egg size and presence or absence of parental care in various species of frogs was gathered from the scientific literature. As a basis for our comparative analyses, we developed a phylogenetic supertree, by combining the results of multiple phylogenetic analyses in the literature using matrix representation parsimony. Using phylogenetic pairwise comparisons we demonstrated a significant association between the evolution of parental care and large egg size. We then used recently developed maximum likelihood methods to infer the evolutionary order of specific transitions. This analysis revealed that the evolution of large egg size typically precedes the evolution of parental care, rather than the reverse. We discuss the relevance of our results to previous hypotheses concerning the evolution of parental care and egg size.
Light on the moth-eye corneal nipple array of butterflies
Authors: Stavenga D.G , Foletti S , Palasantzas G , Arikawa K
Published: February 2006

The outer surface of the facet lenses in the compound eyes of moths consists of an array of excessive cuticular protuberances, termed corneal nipples. We have investigated the moth-eye corneal nipple array of the facet lenses of 19 diurnal butterfly species by scanning electron microscopy, transmission electron microscopy and atomic force microscope, as well as by optical modelling. The nipples appeared to be arranged in domains with almost crystalline, hexagonal packing. The nipple distances were found to vary only slightly, ranging from about 180 to 240 nm, but the nipple heights varied between 0 (papilionids) and 230 nm (a nymphalid), in good agreement with previous work. The nipples create an interface with a gradient refractive index between that of air and the facet lens material, because their distance is distinctly smaller than the wavelength of light. The gradient in the refractive index was deduced from effective medium theory. By dividing the height of the nipple layer into 100 thin slices, an optical multilayer model could be applied to calculate the reflectance of the facet lenses as a function of height, polarization and angle of incidence. The reflectance progressively diminished with increased nipple height. Nipples with a paraboloid shape and height 250 nm, touching each other at the base, virtually completely reduced the reflectance for normally incident light. The calculated dependence of the reflectance on polarization and angle of incidence agreed well with experimental data, underscoring the validity of the modelling. The corneal nipples presumably mainly function to reduce the eye glare of moths that are inactive during the day, so to make them less visible for predators. Moths are probably ancestral to the diurnal butterflies, suggesting that the reduced size of the nipples of most butterfly species indicates a vanishing trait. This effect is extreme in papilionids, which have virtually absent nipples, in line with their highly developed status. A similar evolutionary development can be noticed for the tapetum of the ommatidia of lepidopteran eyes. It is most elaborate in moth-eyes, but strongly reduced in most diurnal butterflies and absent in papilionids.
Interspecific transfer ofWolbachiainto the mosquito disease vectorAedes albopictus
Authors: Xi Zhiyong , Khoo Cynthia C.H , Dobson Stephen L
Published: February 2006

IntracellularWolbachiabacteria are obligate, maternally inherited endosymbionts found frequently in insects and other invertebrates. The evolutionary success ofWolbachiais due in part to an ability to manipulate reproduction. In mosquitoes and many other insects,Wolbachiacauses a form of sterility known as cytoplasmic incompatibility (CI).Wolbachia-induced CI has attracted interest as a potential agent for affecting medically important disease vectors. However, application of the approach has been restricted by an absence of appropriate, naturally occurringWolbachiainfections. Here, we report the interspecific transfer ofWolbachiainfection into a medically important mosquito. Using embryonic microinjection,Wolbachiais transferred fromDrosophila simulansinto the invasive pest and disease vector:Aedes albopictus(Asian tiger mosquito). The resulting infection is stably maintained and displays a unique pattern of bidirectional CI in crosses with naturally infected mosquitoes. Laboratory population cage experiments examine a strategy in which releases ofWolbachia-infected males are used to suppress mosquito egg hatch. We discuss the results in relation to developing appropriateWolbachia-infected mosquito strains for population replacement and population suppression strategies.
Alteration of the chemical environment disrupts communication in a freshwater fish
Authors: Fisher Heidi S , Wong Bob B.M , Rosenthal Gil G
Published: February 2006

It is well established that changes to the chemical environment can impair development, physiology and reproductive biology; by contrast, impacts on communication have not been widely reported. This is surprising given that chemical communication is the most widely used sensory modality in nature, and that variation in the chemical composition of the environment is the rule, not the exception. Here, we show that chemically mediated species recognition in a swordtail fish,
Xiphophorus birchmanni
, can be hindered by anthropogenic disturbance to the signalling environment. Females have a strong preference for conspecific male chemical cues, yet they hybridize in nature with the congener
X. malinche
. Wild-caught females showed a strong preference for conspecifics when tested in clean water, but failed to show a preference when tested in stream water subject to sewage effluent and agricultural runoff. We hypothesized that this was due to the interaction between chemical communication systems and humic acid (HA), a ubiquitous, natural product elevated to high levels by anthropogenic processes. When exposed to elevated concentrations of HA, female
X. birchmanni
again lost their preference for conspecific male chemical cues, while visual mating preferences and motivation to mate were retained. Sub-lethal concentrations of seemingly benign substances can thus have a drastic effect on natural populations through their specific impact on communication systems.
Design complexity and strength of laterality are correlated in New Caledonian crows' pandanus tool manufacture
Authors: Hunt Gavin R , Corballis Michael C , Gray Russell D
Published: February 2006

Population-level laterality is generally considered to reflect functional brain specialization. Consequently, the strength of population-level laterality in manipulatory tasks is predicted to positively correlate with task complexity. This relationship has not been investigated in tool manufacture. Here, we report the correlation between strength of laterality and design complexity in the manufacture of New Caledonian crows' three pandanus tool designs: wide, narrow and stepped designs. We documented indirect evidence of over 5800 tool manufactures on 1232 pandanus trees at 23 sites. We found that the strength of laterality in tool manufacture was correlated with design complexity in three ways: (i) the strongest effect size among the population-level edge biases for each design was for the more complex, stepped design, (ii) the strength of laterality at individual sites was on average greater for the stepped design than it was for the simpler wide and narrow, non-stepped designs, and (iii) there was a positive, but non-significant, trend for a correlation between the strength of laterality and the number of steps on a stepped tool. These three aspects together indicate that greater design complexity generally elicits stronger lateralization of crows' pandanus tool manufacture.
Out of Gondwanaland; the evolutionary history of cooperative breeding and social behaviour among crows, magpies, jays and allies
Authors: Ekman Jan , Ericson Per G.P
Published: February 2006

Cooperative breeding is comparatively rare among birds in the mainly temperate and boreal Northern Hemisphere. Here we test if the distribution of breeding systems reflects a response to latitude by means of a phylogenetic analysis using correlates with geographical range among the corvids (crows, jays, magpies and allied groups). The corvids trace their ancestry to the predominantly cooperative ‘Corvida’ branch of oscine passerines from the Australo-Papuan region on the ancient Gondwanaland supercontinent, but we could not confirm the ancestral state of the breeding system within the family, while family cohesion may be ancestral. Initial diversification among pair-breeding taxa that are basal in the corvid phylogeny, represented by genera such asPyrrhocoraxandDendrocitta, indicates that the corvid family in its current form could have evolved from pair-breeding ancestors only after they had escaped the Australo-Papuan shield. Within the family, cooperative breeding (alloparental care/family cohesion) is strongly correlated to latitude and its predominance in species maintaining a southerly distribution indicates a secondary evolution of cooperative breeding in the lineage leading away from the basal corvids. Multiple transitions show plasticity in the breeding system, indicating a response to latitude rather than evolutionary inertia. The evolutionary background to the loss of cooperative breeding among species with a northerly distribution is complex and differs between species, indicating a response to a variety of selection forces. Family cohesion where the offspring provide alloparental care is a main route to cooperatively breeding groups among corvids. Some corvid species lost only alloparental care, while maintaining coherent family groups. Other species lost family cohesion and, as a corollary, they also lost the behaviour where retained offspring provide alloparental care.
Costs and benefits of a superinfection of facultative symbionts in aphids
Authors: Oliver Kerry M , Moran Nancy A , Hunter Martha S
Published: February 2006

Symbiotic associations between animals and inherited micro-organisms are widespread in nature. In many cases, hosts may be superinfected with multiple inherited symbionts.
Acyrthosiphon pisum
(the pea aphid) may harbour more than one facultative symbiont (called secondary symbionts) in addition to the obligate primary symbiont,
Buchnera aphidicola
. Previously we demonstrated that, in a controlled genetic background,
A. pisum
infected with either
Serratia symbiotica
or
Hamiltonella defensa
(called R- and T-type in that study) were more resistant to attack by the parasitoid
Aphidius ervi
. Here, we examined the consequences of
A. pisum
superinfected with both resistance-conferring symbionts. We found that an
A. pisum
line co-infected with both
S. symbiotica
and
H. defensa
symbionts exhibits even greater resistance to parasitism by
A. ervi
than either of the singly infected lines. Despite this added benefit to resistance, superinfections of
S. symbiotica
and
H. defensa
symbionts appeared rare in our survey of Utah
A. pisum
symbionts, which is probably attributable to severe fecundity costs. Quantitative polymerase chain reaction estimates indicate that while the density of
H. defensa
is similar in singly and superinfected hosts,
S. symbiotica
densities increased dramatically in superinfected hosts. Over-proliferation of symbionts or antagonistic interactions between symbionts may be harmful to the aphid host. Our results indicate that in addition to host–symbiont interactions, interactions among the symbionts themselves probably play a critical role in determining the distributions of symbionts in natural populations.
Reproductive character displacement generates reproductive isolation among conspecific populations: an artificial neural network study
Authors: Pfennig Karin S , Ryan Michael J
Published: February 2006

When interactions with heterospecifics prevent females from identifying conspecific mates, natural selection can promote the evolution of mating behaviours that minimize such interactions. Consequently, mating behaviours may diverge among conspecific populations in sympatry and in allopatry with heterospecifics. This divergence in conspecific mating behaviours—reproductive character displacement—can initiate speciation if mating behaviours become so divergent as to generate reproductive isolation between sympatric and allopatric conspecifics. We tested these ideas by using artificial neural networks to simulate the evolution of conspecific mate recognition in populations sympatric and allopatric with different heterospecifics. We found that advertisement calls diverged among the different conspecific populations. Consequently, networks strongly preferred calls from their own population to those from foreign conspecific populations. Thus, reproductive character displacement may promote reproductive isolation and, ultimately, speciation among conspecific populations.
Prevalence of different modes of parental care in birds
Authors: Cockburn Andrew
Published: February 2006

Estimates of the incidence of major classes of parental care by birds are drawn from classical studies that preceded both the publication of a massive secondary literature and the revolution driven by molecular approaches to avian phylogeny. Here, I review this literature in the light of new phylogenetic hypotheses and estimate the prevalence of six distinct modes of care: use of geothermal heat to incubate eggs, brood parasitism, male only care, female only care, biparental care and cooperative breeding. Female only care and cooperative breeding are more common than has previously been recognized, occurring in 8 and 9% of species, respectively. Biparental care by a pair bonded male and female is the most common pattern of care but at 81% of species, the pattern is less common than once believed. I identify several problems with existing hypotheses for the evolution of parental care and highlight a number of poorly understood contrasts which, once resolved, should help elucidate avian social evolution.
Organization pattern of nacre in Pteriidae (Bivalvia: Mollusca) explained by crystal competition
Authors: Checa Antonio G , Okamoto Takashi , Ramírez Joaquín
Published: February 2006

Bivalve nacre is a brick-wall-patterned biocomposite of aragonite platelets surrounded by organic matter. SEM–electron back scatter diffraction analysis of nacre of the bivalve family Pteriidae reveals that early aragonite crystals grow with their
c
-axes oriented perpendicular to the growth surface but have their
a
- and
b
-axes disoriented. With the accumulation of successive lamellae, crystals progressively orient themselves with their
b
-axes mutually parallel and towards the growth direction. We propose that progressive orientation is a result of competition between nacre crystals at the growth front of lamellae, which favours selection of crystals whose fastest growth axis (
b
-axis) is oriented parallel to the direction of propagation of the lamella. A theoretical model has been developed, which simulates competition of rhombic plates at the lamellar growth front as well as epitaxial growth of crystals onto those of the preceding lamella. The model predicts that disordered nacre progressively produces bivalve-like oriented nacre. As growth fronts become diffuse (as is the common case in bivalves) it takes longer for nacre to become organized. Formation of microdomains of nacre platelets with different orientations is also reproduced. In conclusion, not only the organic matrix component, but also the mineral phase plays an active role in organizing the final microstructure.
On the rate and causes of twentieth century sea-level rise
Authors: Miller Laury , Douglas Bruce C
Published: February 2006

Both the rate and causes of twentieth century global sea-level rise (GSLR) have been controversial. Estimates from tide-gauges range from less than one, to more than two millimetre yr
−1
. In contrast, values based on the processes mostly responsible for GSLR—mass increase (from mountain glaciers and the great high latitude ice masses) and volume increase (expansion due to ocean warming)—fall below this range. Either the gauge estimates are too high, or one (or both) of the component estimates is too low. Gauge estimates of GSLR have been in dispute for several decades because of vertical land movements, especially due to glacial isostatic adjustment (GIA). More recently, the possibility has been raised that coastal tide-gauges measure exaggerated rates of sea-level rise because of localized ocean warming. Presented here are two approaches to a resolution of these problems. The first is morphological, based on the limiting values of observed trends of twentieth century relative sea-level rise as a function of distance from the centres of the ice loads at last glacial maximum. This observational approach, which does not depend on a geophysical model of GIA, supports values of GSLR near 2 mm yr
−1
. The second approach involves an analysis of long records of tide-gauge and hydrographic (
in situ
temperature and salinity) observations in the Pacific and Atlantic Oceans. It was found that sea-level trends from tide-gauges, which reflect both mass and volume change, are 2–3 times higher than rates based on hydrographic data which reveal only volume change. These results support those studies that put the twentieth century rate near 2 mm yr
−1
, thereby indicating that mass increase plays a much larger role than ocean warming in twentieth century GSLR.
The influence of the North Atlantic Oscillation on the sea-level around the northern European coasts reconsidered: the thermosteric effects
Authors: Tsimplis M.N , Shaw A.G.P , Flather R.A , Woolf D.K
Published: February 2006

The thermosteric contribution of the North Atlantic Oscillation (NAO) to the North Sea sea-level for the winter period is investigated. Satellite sea surface temperature as well as
in situ
measurements are used to define the sensitivity of winter water temperature to the NAO as well as to determine the trends in temperature. The sea surface temperature sensitivity to the NAO is about 0.85 °C per unit NAO, which results in thermosteric sea-level changes of about 1–2 cm per unit NAO. The sensitivity of sea surface temperatures to the NAO is strongly time-dependent. Model data from a two-dimensional hydrodynamic tide+surge model are used in combination with the estimated thermosteric anomalies to explain the observed sea-level changes and, in particular, the sensitivity of the datasets to the NAO variability. The agreement between the model and the observed data is improved by the inclusion of the thermosteric effect.
Towards improved empirical isobase models of Holocene land uplift for mainland Scotland, UK
Authors: Smith David E , Fretwell Peter T , Cullingford Robin A , Firth Callum R
Published: February 2006

A new approach to modelling patterns of glacio-isostatic land uplift during the Holocene in mainland Scotland, UK, is described. The approach is based upon altitude measurements at the inner margin or locally highest point of raised estuarine surfaces dated by radiocarbon assay supported by microfossil analyses. 2241 altitudes have been analysed by a technique new to studies of former sea-levels, Gaussian Trend Surface Analysis, and isobase models for four Holocene shorelines: the Holocene Storegga Slide tsunami shoreline, abandoned rapidlycirca7900 sidereal years BP; the Main Postglacial shoreline, abandoned duringcirca6400–7700 sidereal years BP; the Blairdrummond shoreline, abandoned duringcirca4500–5800 sidereal years BP, and a speculative fourth shoreline, the Wigtown shoreline, abandoned duringcirca1520–3700 sidereal years BP, are shown in a series of maps. The implications of the shoreline patterns for glaicio-isostasy in the area are discussed. It is maintained that the statistical technique used enables broad estimates to be made of nearshore sea surface change.
Managing patients with acute liver failure: developing a tool for practitioners
Authors: O'Neal Helen , Olds Jane , Webster Nicola
Published: February 2006

Patients with acute liver failure (ALF) are treated on the general intensive care unit (ICU) within this regional centre for hepatology and liver transplantation. This group of patients are at high risk of developing cerebral oedema, but because of the associated coagulopathy, intracranial pressure is not measured invasively. The safe management of these patients is vital to their outcome, and yet, there is no national or local guidance on the best practice for this group of patients.

An absence of guidelines, or evidence base specific to caring for hepatology patients, was highlighted as we reviewed local clinical practices and those at other liver specialty centres, the British Liver Trust and published literature. We identified a need to develop evidence‐based guidance for staff caring for patients with ALF within ICUs. A systematic approach enabled us to identify best practice to support the development of a structured evidence‐based approach to care.
The pathophysiology of hepatic encephalopathy
Authors: Faint Victoria
Published: February 2006

Hepatic encephalopathy (HE) is a complicated disorder, the pathophysiology of which remains to be fully understood. This article reviews the current main theories including the potential involvement of ammonia, γ‐aminobutyric acid (GABA)/benzodiazipines and false neurotransmitters. Each theory is critically examined with the evidence for each reviewed carefully, and the potential relationship of ammonia to the remaining two theories explored. Known preciptating factors of HE are also considered as evidence. The conclusions drawn from the evidence provided indicate the large role played by ammonia and suggest that this may be the key to understanding HE as science progresses.
Introducing intensive insulin therapy: the nursing perspective
Authors: Preston Sharon , Laver Stephen R. , Lloyd Wendy , Padkin Andrew
Published: February 2006

Intensive insulin therapy (IIT) for the management of high blood glucose can reduce mortality and morbidity in the critically ill. However, there is little published literature on how to implement it successfully.

The aim of this study is to chronicle the development and difficulties encountered in implementing an IIT protocol in a critical care unit in a district general hospital.

A nurse‐led protocol was developed. Qualitative audit was undertaken during development and implementation to identify potential problems with using the Bath Insulin Protocol. Regular feedback sessions were introduced to encourage change and further identify problem issues.

Qualitative audit led to changes in practice for individual nurses and changes to other unit protocols. The main change for individual nurses was to measure blood glucose hourly using a bedside glucometer. The unit's feeding and drug dilution policies were identified as a potential cause of glucose instability and were modified.

To implement IIT successfully, it is necessary to consider changing working practices and to identify other unit protocols which can cause glucose instability. The additional nursing workload must be considered and appropriate means of supporting staff identified.
The value and role of skin and nail assessment in the critically ill
Authors: Massey Debbie
Published: February 2006

Over the last 10 years, numerous political drivers have paved the way for the development of new and innovative models of practice within the critical care environment. Many of these new models of practice required practitioners to perform detailed and comprehensive patient assessment. Within critical care, respiratory assessment is increasingly regarded as an essential element of a critical care practitioner's profile. However, the assessment of other body systems has been adopted more slowly. This article argues that skin and nail assessment should be ascribed a high priority within practitioners’ scope of practice. The skin is the largest organ in the body. A wide range of diseases covering numerous pathologies and specialities manifest in changes in the skin and nails. There has been increasing realization and recognition that there is a connection between the skin and systemic disease. The skin and nails can therefore give valuable diagnostic clues to underlying disease. This article offers practitioners an opportunity to develop and augment their knowledge and understanding of skin and nail assessment and its application to the critically ill patient.
Components of diesel exhaust particles differentially affect Th1/Th2 response in a murine model of allergic airway inflammation
Authors: Yanagisawa R. , Takano H. , Inoue K.‐i. , Ichinose T. , Sadakane K. , Yoshino S. , Yamaki K. , Yoshikawa T. , Hayakawa K.
Published: February 2006

Background
Diesel exhaust particles (DEP) can enhance various respiratory diseases. However, it is unclear as to which components in DEP are associated with the enhancement. We investigated the effects of DEP components on antigen‐related airway inflammation, using residual carbonaceous nuclei of DEP after extraction (washed DEP), extracted organic chemicals (OC) in DEP (DEP–OC), and DEP–OC plus washed DEP (whole DEP) in the presence or absence of ovalbumin (OVA).

Methods
Male ICR mice were intratracheally administrated with OVA and/or DEP components. We examined the cellular profile of bronchoalveolar lavage (BAL) fluid, histological changes, lung expression of inflammatory molecules, and antigen‐specific production of IgG1 in the serum.

Results
DEP–OC, rather than washed DEP, enhanced infiltration of inflammatory cells into BAL fluid, magnitude of airway inflammation, and proliferation of goblet cells in the airway epithelium in the presence of OVA, which was paralleled by the enhanced lung expression of eotaxin and IL‐5 as well as the elevated concentration of OVA‐specific IgG1. In contrast, washed DEP with OVA showed less change and increased the lung expression of IFN‐γ. The combination of whole DEP and OVA caused the most remarkable changes in the entire enhancement, which was also accompanied by the enhanced expression of IL‐13 and macrophage inflammatory protein‐1α.

Conclusion
DEP–OC, rather than washed DEP, exaggerated allergic airway inflammation through the enhancement of T‐helper type 2 responses. The coexistence of OC with carbonaceous nuclei caused the most remarkable aggravation. DEP components might diversely affect various types of respiratory diseases, while whole DEP might mostly aggravate respiratory diseases.
Impaired functionality and phenotypic profile of dendritic cells from patients with multiple myeloma
Authors: Brimnes M K , Svane I M , Johnsen H E
Published: February 2006

Multiple myeloma (MM) is a B cell cancer characterized by clonal proliferation in the bone marrow and impaired immunity. Because MM is an incurable malignancy, efficient consolidation is needed urgently. Targeting clonotypic B cells by idiotype vaccination has proved the principle to be effective and indicated that future strategies, including dendritic cell-based vaccination, could be a suitable approach. However, as MM patients suffer from a general impaired immunity, which may include dendritic cells (DCs), a careful evaluation of phenotypic traits and functionality of DCs from MM patients is necessary before an efficient vaccine can be developed. This study determined the number, phenotypic profile and functionality of myeloid and plasmacytoid DCs purified directly from blood from MM patients at diagnosis. A reduced number and lower expression of human leucocyte antigen (HLA) molecules was observed on both myeloid and plasmacytoid DCs in MM patients compared to healthy controls. Also, the expression of CCR5, CCR7 and DEC205 was lower in MM patients compared to normal donors. In addition, the capacity to stimulate allogeneic T cell proliferation and to stimulate cytokine production was decreased, suggesting that DCs from these patients are functionally impaired. Finally, the analysis of samples following chemotherapy and transplantation demonstrated an increased expression of HLA molecules, suggesting that this time-point is optimal for harvest and use in vaccination.
Spawning habitat and daily egg production of sardine (Sardina pilchardus) in the eastern Mediterranean
Authors: SOMARAKIS S. , GANIAS K. , SIAPATIS A. , KOUTSIKOPOULOS C. , MACHIAS A. , PAPACONSTANTINOU C.
Published: February 2006

Spawning habitats of two eastern Mediterranean sardine, Sardina pilchardus (Walbaum, 1792), stocks (coastal waters of central Aegean and Ionian Seas) are characterized from daily egg production method (DEPM) surveys conducted during the peak of the spawning period. The latter occurs earlier in the Aegean Sea (December) than in the less‐productive Ionian Sea (February). Single‐parameter quotient analysis showed that the preferred bottom depth for spawning was 40–90 m in both areas but sardine selected sites of increased zooplankton in the Aegean Sea during December and increased fluorescence in the Ionian Sea during February. Estimates of daily egg production (P) and spawning stock biomass (B) were about four times lower for the Ionian Sea (P = 7.81 eggs m−2, B = 3652 tonnes) than the Aegean Sea (P = 27.52 eggs m−2, B = 16 174 tonnes). We suggest that zooplankton biomass might not be sufficient to support sardine reproduction in the highly oligotrophic Ionian Sea where the very small sardine stock may rely on the late‐winter phytoplankton bloom. Actively selecting sites with increased zooplankton or phytoplankton and feeding plasticity (the well‐known switching from selective particle feeding to non‐selective filter feeding in sardines) are interpreted as adaptations to grow and reproduce optimally at varying prey conditions. Despite differences in temperature and productivity regimes, reproductive performance of sardine in the Ionian Sea was very similar to that in the Aegean Sea during the peak of the spawning period. In comparing adult parameters from DEPM applications to Sardina and Sardinops stocks around the world, a highly significant linear relation emerged between mean batch fecundity (F) and mean weight of mature female (W, g) (F = 0.364W, r2 = 0.98). The latter implies that, during the peak of the spawning period, mean relative batch fecundity (eggs g−1) of sardine is fairly constant in contrasting ecosystems around the world.
Does leaf quality mediate the stimulation of leaf breakdown by phosphorus in Neotropical streams?
Authors: ARDÓN MARCELO , STALLCUP LINDSAY A. , PRINGLE CATHERINE M.
Published: February 2006

1. Lowland tropical streams have a chemically diverse detrital resource base, where leaf quality could potentially alter the effect of high nutrient concentrations on leaf breakdown. This has important implications given the extent and magnitude of anthropogenic nutrient loading to the environment.

2. Here, we examine if leaf quality (as determined by concentrations of cellulose, lignin and tannins) mediates the effects of high ambient phosphorus (P) concentration on leaf breakdown in streams of lowland Costa Rica. We hypothesised that P would have a stronger effect on microbial and insect processing of high‐ than of low‐quality leaves.

3. We selected three species that represented extremes of quality as measured in leaves of eight common riparian species. Species selected were, from high‐ to low‐quality: Trema integerrima > Castilla elastica > Zygia longifolia. We incubated single‐species leaf packs in five streams that had natural differences in ambient P concentration (10–140 μg soluble reactive phosphorus (SRP) L−1), because of variable inputs of solute‐rich groundwater and also in a stream that was experimentally enriched with P (approximately 200 μg SRP L−1).

4. The breakdown rate of all three species varied among the six streams: T. integerrima (k‐values range: 0.0451–0.129 day−1); C. elastica (k‐values range: 0.0064–0.021 day−1); and Z. longifolia (k‐values range: 0.002–0.008 day−1). Both ambient P concentration and flow velocity had significant effects on the breakdown rate of the three species.

5. Results supported our initial hypothesis that litter quality mediates the effect of high ambient P concentration on leaf processing by microbes and insects. The response of microbial respiration, fungal biomass and invertebrate density to high ambient P concentration was greater in Trema (high quality) than in Castilla or Zygia (low quality). Variation in flow velocity, however, confounded our ability to determine the magnitude of stimulation of breakdown rate by P.

6. Cellulose and lignin appeared to be the most important factors in determining the magnitude of P‐stimulation. Surprisingly, leaf secondary compounds did not have an effect. This contradicts predictions made by other researchers, regarding the key role of plant secondary compounds in affecting leaf breakdown in tropical streams.
Temporal response of stream benthic macroinvertebrate communities to the synergistic effects of anthropogenic acidification and natural drought events
Authors: BOWMAN MICHELLE F. , SOMERS KEITH M. , REID R. A. , SCOTT L. D.
Published: February 2006

1. We evaluated whether the surprisingly weak biological recovery associated with declines in acid deposition were related to drought‐induced re‐acidification of streams. We used test site analysis (TSA) to characterise temporal changes (1995–2003) in the degree and nature of impairments to stream benthic macroinvertebrate (BMI) communities influenced by acid deposition and drought.

2. The BMI communities in four historically impacted test streams were compared with communities in 30 minimally impacted reference streams. Six multivariate (e.g. ordination axes scores) and four traditional (e.g. % Diptera) summary metrics were used to describe BMI communities. Using all metrics simultaneously (i.e. Mahalanobis or generalised distance), the TSA provided a single probability that a test community was impaired. If a test community was significantly impaired, a further analysis was done to identify the metric(s) important in distinguishing the test community from reference condition.

3. Results of the TSAs indicated that the generalised distances between test communities and the reference condition were inversely related to stream water pH (n = 36). The TSAs also indicated ordination metrics based on BMI abundance were important in distinguishing significantly impaired communities from reference conditions. Temporal trends indicated that there has been short‐term recovery of these BMI communities, but that overall improvements have been hampered by acid or metal toxicity associated with drought‐induced re‐acidification of the streams.

4. Our use of a variety of summary metrics to obtain a single statistical test of significance within the context of the reference‐condition approach provided a simple and unambiguous framework for evaluating the biological condition of test sites.
Chytrid infections of Daphnia pulicaria: development, ecology, pathology and phylogeny of Polycaryum laeve
Authors: JOHNSON PIETER T. J. , LONGCORE JOYCE E. , STANTON DANIEL E. , CARNEGIE RYAN B. , SHIELDS JEFFREY D. , PREU ERIC R.
Published: February 2006

1. We combined ecological surveys, life table studies, microscopy and molecular sequencing to determine the development, ecology, pathology and phylogeny of Polycaryum laeve, an endoparasite of cladocerans. We report the first records of P. laeve from North America, where we have used a polymerase chain reaction primer and microscopic examination to confirm infections in 14 lakes. Infections are highly pathogenic and caused increased mortality, reduced growth, and reproductive castration in Daphnia pulicaria during life table studies.

2. Biweekly data from Allequash Lake (Wisconsin, U.S.A.) throughout 2003 indicated that fecundity and infection prevalence were inversely correlated. Infection prevalence was highest in late winter and early spring (up to 80%) and lowest during late summer. Epidemics were generally followed by sharp declines in host population density (up to 99%).

3. Within the haemocoel of its host, P. laeve forms thick‐walled sporangia, which occur systemically in later stages of infection. Fungal thalli associate closely with muscle fibres and connective tissue, leading to degeneration as the infection becomes advanced. Following death of the host, flagellated zoospores are released through an exit papilla on the sporangium. Based on the infection‐induced castration of the host and increases in infection prevalence with Daphnia size, we postulate that transmission is horizontal, but may be indirect through an additional host or free‐living stage.

4. Molecular and morphological data clearly indicate that P. laeve belongs in the fungal phylum Chytriodiomycota, order Blastocladiales. Based on ribosomal RNA gene sequences and morphological features, we transfer the genus Polycaryum from the Haplosporidia to the Chytridiomycota, and designate a lectotype and epitype for P. laeve. Considering the high prevalence of P. laeve infection within Daphnia populations, the frequency with which we detected infections among lakes, and the keystone importance of large‐bodied Daphnia in aquatic food webs, we suggest that P. laeve may exert a regulatory influence on Daphnia populations in lake ecosystems.
Endothelial mechanotransduction, nitric oxide and vascular inflammation
Authors: HARRISON D. G. , WIDDER J. , GRUMBACH I. , CHEN W. , WEBER M. , SEARLES C.
Published: February 2006

Numerous aspects of vascular homeostasis are modulated by nitric oxide and reactive oxygen species (ROS). The production of these is dramatically influenced by mechanical forces imposed on the endothelium and vascular smooth muscle. In this review, we will discuss the effects of mechanical forces on the expression of the endothelial cell nitric oxide synthase, production of ROS and modulation of endothelial cell glutathione. We will also review data that exercise training in vivo has a similar effect as laminar shear on endothelial function and discuss the clinical relevance of these basic findings.
Molecular mechanisms of the vascular responses to haemodynamic forces
Authors: LEHOUX S. , CASTIER Y. , TEDGUI A.
Published: February 2006

Blood vessels are permanently subjected to mechanical forces in the form of stretch, encompassing cyclic mechanical strain due to the pulsatile nature of blood flow and shear stress. Significant variations in mechanical forces, of physiological or physiopathological nature, occur in vivo. These are accompanied by phenotypical modulation of smooth muscle cells and endothelial cells, producing structural modifications of the arterial wall. In all the cases, vascular remodelling can be allotted to a modification of the tensional strain or shear, and underlie a trend to reestablish baseline mechanical conditions. Vascular cells are equipped with numerous receptors that allow them to detect and respond to the mechanical forces generated by pressure and shear stress. The cytoskeleton and other structural components have an established role in mechanotransduction, being able to transmit and modulate tension within the cell via focal adhesion sites, integrins, cellular junctions and the extracellular matrix. Mechanical forces also initiate complex signal transduction cascades, including nuclear factor‐κB and mitogen‐activated protein kinase pathways, leading to functional changes within the cell.