bluuebunny/crossref_metadata_2025 huggingface dataset:
Clients with chronic and complex conditions: their experiences of community nursing services
Authors: Wilkes Lesley , Cioffi Jane , Warne Bronwyn , Harrison Kathleen , Vonu‐Boriceanu Oana
Published: June 2008

Aim.  This qualitative study aimed to explore and describes clients’ experiences of receiving care from community nurses.

Background.  Understanding of the experiences of clients with chronic and complex conditions receiving community nursing care can provide insight into their needs. International studies have identified experiences clients have had of receiving care from community nurses. However, no Australian study was found that had specifically explored with clients who had chronic and complex conditions and their experiences of receiving care from community nurses in an area health service.

Design.  A qualitative descriptive study conducted during 2005 explored and described clients’ experiences of the nursing care provided by community nurses.

Method.  A purposive sample of 13 volunteer participants with chronic and complex conditions was interviewed and the transcripts analysed.

Results.  Three main categories were identified that clients used to describe their experiences. These were: the client’s relationship with the nurse, care process and being able to stay out of hospital.

Conclusions.  Clients strongly indicated their satisfaction with care provided by experienced community nurses and acknowledged that nurses are playing a key role in fostering their self‐management and avoiding their readmission to hospital. Areas that require further attention are the professional development of less‐experienced community nurses, services at the weekend, the scope of nursing management of clients with chronic conditions and the education needs of community nurses to meet the goals of these clients.

Relevance to clinical practice.  This study highlights the need for nurses who work in strong autonomous clinical roles in the community to have experience in assessment, education, planning and delivery of client care before they can be competent community nurses. The possibility of adverse occurrences during weekends provides the opportunity for managers to review and plan weekday and weekend workloads and staffing.
Effects of canopy heterogeneity, seed abscission and inertia on wind‐driven dispersal kernels of tree seeds
Authors: Bohrer Gil , Katul Gabriel G. , Nathan Ran , Walko Robert L. , Avissar Roni
Published: June 2008

Understanding seed dispersal by wind and, in particular, long‐distance dispersal (LDD) is needed for management of plant populations and communities, especially in response to changes in climate, land use and natural habitats. Numerical models designed to explore complex, nonlinear atmospheric processes are essential tools for understanding the fundamental mechanisms involved in seed dispersal. Yet, thus far, nearly all such models have not explicitly accounted for the spatial heterogeneity that is a typical feature of all ecosystems.

The recently developed Regional Atmospheric Modelling System (RAMS)‐based Forest Large Eddy Simulation (RAFLES) is used here to explore how within‐stand canopy heterogeneity impacts LDD. RAFLES resolves microscale canopy heterogeneity such as small gaps and variable tree heights, and it simulates their impacts on turbulence inside and above the canopy in the atmospheric boundary layer (ABL). For that purpose, an Eulerian–Lagrangian module of seed dispersal is added to RAFLES to simulate seed trajectories.

Particular attention is paid to the sensitivity of statistical attributes of the dispersal kernels (i.e. mean, mode, variance, tail) to key simplifications common to all seed dispersal models, such as horizontal homogeneity in the canopy and flow field, and the tight coupling between air parcel trajectories and seed trajectories (i.e. neglecting seed inertia). These attributes appear to be sensitive to various factors operating at scales ranging from the seed scale to the ABL scale.

Simulations with RAFLES show that LDD is characterized by a dispersal kernel with a ‘tail’, asymptotically approaching a power law decay of –3/2 (mainly occurring for lighter seeds at high wind speeds). This is consistent with asymptotic predictions from analytical models. The wind speed threshold at which seed abscission occurs, set‐up to be twice the standard deviation of the vertical wind speed, is shown to affect short‐distance dispersal, but has no significant impact on LDD. Ignoring the effects of seed inertia on the seed trajectory calculations has a minor effect on short‐distance dispersal and no effect on the probability of seed uplift. Thus, it has no significant impact on LDD.

Synthesis. Tree‐scale canopy heterogeneity affects the turbulence characteristics inside and above the canopy and, consequently, this affects dispersal kernel statistics. A key finding from this study is that ejection is enhanced above the shorter trees of the canopy. Seeds dispersed above shorter trees have a higher probability of experiencing LDD while their short‐distance dispersal remains practically the same. At inter‐annual time scales, such interactions could affect species composition.
Plant fecundity and seed dispersal in spatially heterogeneous environments: models, mechanisms and estimation
Authors: Schurr Frank M. , Steinitz Ofer , Nathan Ran
Published: June 2008

Plant fecundity and seed dispersal often depend on environmental variables that vary in space. Hence, plant ecologists need to quantify spatial environmental effects on fecundity and dispersal.

We present an approach to estimate and model two types of spatial environmental effects:source effectscause fecundity and dispersal to vary as a function of a source's local environment, whereaspath effectsdepend on all environments a seed encounters during dispersal. Path effects are described by first transforming physical space so that areas of low seed permeability are enlarged relative to others, and then evaluating dispersal kernels in this transformed ‘movement space’.

Models for source and path effects are embedded into the established inverse modelling (IM) framework. This enables the statistical estimation of environmental effects from easily available data on the spatial distribution of seeds, seed sources and environmental covariates.

The presented method is applied to data from a well‐studied population of the wind‐dispersed Aleppo pine (Pinus halepensis). We use local tree density as an environmental covariate, model fecundity as a function of a tree's basal area, and consider four dispersal kernels: WALD (a closed‐form mechanistic model for seed dispersal by wind), log‐normal, exponential power and 2Dt.

The inclusion of source and path effects of tree density markedly improves IM performance. IM analyses and independent data agree in the parameter range of the mechanistic WALD kernel and in suggesting weak negative density‐dependence of fecundity. Of 64 IMs considered, the best four involve the WALD kernel and negative source effects on its shape parameter. The best IM predicts that increasing tree density at the source shortens median dispersal distance while enhancing long‐distance dispersal (LDD). Additionally, path effects lead to lower seed permeability of high density areas. These results shed light on the mechanisms by which environmental variation affects fecundity and dispersal ofP. halepensis. Moreover, the predicted density‐dependent dispersal causes a pronounced lag‐phase in simulations of population spread.

Synthesis. The presented method can quantify environmental effects on fecundity and dispersal in a wide range of study systems. The movement space concept may furthermore promote a unified understanding of how various organisms move through spatially heterogeneous environments.
Inequalities in fruit‐removal and seed dispersal: consequences of bird behaviour, neighbourhood density and landscape aggregation
Authors: Carlo Tomás A. , Morales Juan M.
Published: June 2008

Frugivores disperse the seeds of the majority of woody plant species world‐wide. Thus, insights on how frugivores influence the dispersal of plants and the variability of this process are crucial for understanding plant population dynamics in a rapidly changing world.

We used a spatially explicit, stochastic, individual‐based model that simulates fruit‐removal and seed dispersal by birds to assess bird density, landscape and neighbourhood effects on the inequalities of within‐population fruit‐removal rates and seed dispersal. We also compared model predictions with spatially‐explicit field data.

In our simulations, bird density had a strong effect on the distribution of fruit‐removal rates creating large inequalities among plants. Also, for equal bird densities, inequalities increased with the landscape level aggregation of plants.

Fruit removal increased with increasing plant neighbourhood density although there was a tendency to decline at the highest densities. Neighbourhood density also changed average dispersal distances, but with shorter distances at higher densities. Plants with few neighbours not only had longer distance dispersal but also a larger variance in seed rain across distances than plants with ten or more neighbours. These relationships between neighbourhood density and fruit removal and dispersal distance were scale‐dependent with a peak in correlations at 150‐m radius.

Similar to model predictions, field data shows an inverse relationship between dispersal distances (inferred from bird movements) and fruiting neighbourhood density. Also, fruit‐removal rates observed in the field show large numbers of plants receiving little or zero fruit‐removal. Fruit‐removal rate distributions were statistically indistinguishable between the simulation and field data. But, distributions were strikingly different from two alternative models that lacked spatial effects.

Synthesis. Our model and field data show that as fruiting plants become aggregated, inequalities in fruit‐removal rates increase and seed dispersal distance decreases. Both of these processes could help create and maintain plant aggregation and affect genetic structuring. The model also predicts that small‐scale neighbourhood effects can be controlled by large‐scale processes such as overall frugivore abundance and landscape‐level plant aggregation. Most importantly, both simulations and field data shows an interaction between plant spatial pattern and bird foraging, which results in neighbourhood‐specific dispersal and rates of fruit removal.
The effect of collisions with vegetation elements on the dispersal of winged and plumed seeds
Authors: Pounden E. , Greene D. F. , Quesada M. , Contreras Sánchez J. M.
Published: June 2008

The role of collisions with vegetation elements in seed dispersal by wind has been examined only anecdotally. In particular, the idea that the effect of collisions in dispersal may depend on the aerodynamic class of the diaspore has not been broached.

We adapted a collision model for small particles to predict the probability of a winged or plumed seed colliding with a vegetation element as a function of the Stokes number (a dimensionless parameter which quantifies inertial tendency and includes diaspore terminal velocity, wind speed and diameter of the target element).

We performed experimental releases of seeds upwind of tree boles in two deciduous forest types (temperate and dry tropical) for 10 mid‐latitude and tropical species to test the collision model. The model was a reasonable expression of collision efficiency. At higher Stokes numbers, collisions were far more likely for seeds than for water droplets or other small particles.

Experimental releases were used in both forests to determine the effect of collisions with boles on distance travelled for several species. Seeds of the three species with asymmetric wings had significantly reduced dispersal following collisions; the single species with plumed seeds did not.

In a leafless tropical forest, we experimentally determined the frequency distribution of collisions per metre of travel for seeds released from a canopy. Approximately one collision occurred for every 2 m of flight through the volume occupied by branches and lianas. Distance achieved by asymmetric samaras was relatively unaffected by collisions with small vegetation elements, because the samaras quickly readopted stable autorotation. Conversely, bilaterally symmetric samaras had their dispersal greatly reduced.

Synthesis. The effect of collisions on dispersal depends on aerodynamic type. Collisions with small vegetation elements in forests should be more common for samaras than for plumed seeds, because plumed seeds generally have lower terminal velocities. Among winged seeds, collisions with branches will not seriously reduce dispersal except for bilaterally symmetric diaspores, because they are unable to rapidly regain stable autorotation. Reduction in dispersal due to collisions with boles will be unimportant because bole collisions, unlike branch collisions, are rare.
Costs of persistence and the spread of competing seeders and sprouters
Authors: Higgins Steven I. , Flores Olivier , Schurr Frank M.
Published: June 2008

Trade‐offs between reproduction and persistence are thought to regulate life‐history evolution and competitive interactions between plants. We examined how seeder (non‐persistent semelparous) and sprouter (persistent iteroparous) life‐history strategies compete in fire prone shrublands.

Our hypothesis was that a trade‐off between persistence and colonization ability implies that seeders would be better colonizers than sprouters and would therefore stand to benefit from periods of rapid climate change, whereas sprouters are candidates for extinction in periods of shifting climates because of their relatively poor ability to colonize.

We developed an individual based simulation model that simulates lottery plant competition in a homogeneous spatial arena. We used an indirect method to estimate the fecundity and dispersal parameters needed by the model. Dispersal was described by a lognormal dispersal kernel.

We found that coexistence was possible in the system only for a restricted range of conditions. Moreover, the model when parameterized using our empirical estimates of demographic and dispersal rates, suggested that the sprouting strategies have a competitive advantage in the system we studied.

The migration capacities of the sprouter species were substantially lower than those of the seeder species. Our simulations suggested that, even though sprouters had a competitive advantage over seeders, interspecific competitive interactions did not slow the spread of seeder species, but did substantially hamper the spread of the slower spreading sprouter species.

Synthesis. We conclude that, in fire driven systems characterized by lottery recruitment, existing theories of colonization – persistence trade‐offs do not completely describe interactions between persistent and non‐persistent strategies. Moreover, our investigation of seeder – sprouter interactions suggests that sprouters, even though they might be competitively superior, will be more threatened by periods of rapid climate change because of their limited colonization ability.
Interspecific variation in primary seed dispersal in a tropical forest
Authors: Muller‐Landau Helene C. , Wright S. Joseph , Calderón Osvaldo , Condit Richard , Hubbell Stephen P.
Published: June 2008

We investigated the relationships of seed size, dispersal mode and other species characteristics to interspecific variation in mean primary seed dispersal distances, mean annual seed production per unit basal area, and clumping of seed deposition among 41 tropical tree species on Barro Colorado Island, Panama.

A hierarchical Bayesian model incorporating interannual variation in seed production was used to estimate seed dispersal, seed production, and clumping of seed rain for each species from 19 years of data for 188 seed traps on a 50‐ha plot in which all adult trees were censused every 5 years.

Seed dispersal was modelled as a two‐dimensional Student'sTdistribution with the degrees of freedom parameter fixed at 3, interannual variation in seed production per basal area was modelled as a lognormal, and the clumping of seed rain around its expected value was modelled as a negative binomial distribution.

There was wide variation in seed dispersal distances among species sharing the same mode of seed dispersal. Seed dispersal mode did not explain significant variation in seed dispersal distances, but did explain significant variation in clumping: animal‐dispersed species showed higher clumping of seed deposition.

Among nine wind‐dispersed species, the combination of diaspore terminal velocity, tree height and wind speed in the season of peak dispersal explained 40% of variation in dispersal distances. Among 31 animal‐dispersed species, 20% of interspecific variation in dispersal distances was explained by seed mass (a negative effect) and tree height (a positive effect).

Among all species, seed mass, tree height and dispersal syndrome explained 28% of the variation in mean dispersal distance and seed mass alone explained 45% of the variation in estimated seed production per basal area.

Synthesis. There is wide variation in patterns of primary seed rain among tropical tree species. Substantial proportions of interspecific variation in seed production, seed dispersal distances, and clumping of seed deposition are explained by relatively easily measured plant traits, especially dispersal mode, seed mass, and tree height. This provides hope for trait‐based generalization and modelling of seed dispersal in tropical forests.
Measuring long‐distance seed dispersal in complex natural environments: an evaluation and integration of classical and genetic methods
Authors: Jones F. Andy , Muller‐Landau Helen C.
Published: June 2008

Seed dispersal is a critical life stage of plants, yet accurate measurement of dispersal distances has been difficult in natural systems. Genetic techniques for matching dispersed seeds to maternal trees provide valuable data on dispersal events. Questions remain regarding how best to estimate the population seed dispersal distance distributions from such data and how these estimates compare with classical non‐genetic estimates based on seed trap data alone.

Using simulated data, we compared seed shadow estimates obtained via standard inverse modelling of seed arrival into seed traps within mapped stands (summed seed shadow, SSS) with estimates from four models using genetic matches: direct fitting of the observed distribution of distances in the genotyped sample (observed distance, OBS), direct fitting inversely weighted by sampling intensity (OBSw), inverse modelling of numbers of seeds of each genotype in each trap (gene shadow model, GSM), and inverse modelling of frequencies of each genotype in each trap (competing sources model, CSM). We further explored how consideration of immigrant seed rain from unmapped and ungenotyped trees outside the stand affected dispersal estimates, denoting these variants SSSi, GSMi and CSMi.

We applied these models to an empirical data set for the Neotropical tree Jacaranda copaia, using a hierarchical Bayesian model to incorporate variation in fecundity among trees.

Fits to simulated data sets showed that OBS and SSS estimates were strongly biased, while SSSi, GSMi and CSMi were mildly biased. Root mean square errors varied as OBS >> SSS > OBSw > CSMi > GSMi > SSSi > CSM > GSM.

Comparing results for Jacaranda under the three best models, mean posterior estimates of dispersal distances varied as SSSi < GSM < CSM, but credible intervals overlapped among all three models, demonstrating agreement that long‐distance dispersal is common.

Synthesis. Here we reconcile two general approaches used to study seed dispersal distances in natural communities. Genetic and non‐genetic approaches can both provide good estimates of seed dispersal provided that analyses of genetic data take account of any deviation from random selection of seeds for genotyping, and that SSS models consider immigrant seed rain in the analysis whenever there is reason to think its contribution is non‐zero. The use of the models presented here should provide better estimates of population‐level dispersal distance distributions in genetic and classical seed dispersal studies.
Bruxism physiology and pathology: an overview for clinicians*
Authors: LAVIGNE G. J. , KHOURY S. , ABE S. , YAMAGUCHI T. , RAPHAEL K.
Published: June 2008

Summary  Awake bruxism is defined as the awareness of jaw clenching. Its prevalence is reported to be 20% among the adult population. Awake bruxism is mainly associated with nervous tic and reactions to stress. The physiology and pathology of awake bruxism is unknown, although stress and anxiety are considered to be risk factors. During sleep, awareness of tooth grinding (as noted by sleep partner or family members) is reported by 8% of the population. Sleep bruxism is a behaviour that was recently classified as a ‘sleep‐related movement disorder’. There is limited evidence to support the role of occlusal factors in the aetiology of sleep bruxism. Recent publications suggest that sleep bruxism is secondary to sleep‐related micro‐arousals (defined by a rise in autonomic cardiac and respiratory activity that tends to be repeated 8–14 times per hour of sleep). The putative roles of hereditary (genetic) factors and of upper airway resistance in the genesis of rhythmic masticatory muscle activity and of sleep bruxism are under investigation. Moreover, rhythmic masticatory muscle activity in sleep bruxism peaks in the minutes before rapid eye movement sleep, which suggests that some mechanism related to sleep stage transitions exerts an influence on the motor neurons that facilitate the onset of sleep bruxism. Finally, it remains to be clarified when bruxism, as a behaviour found in an otherwise healthy population, becomes a disorder, i.e. associated with consequences (e.g. tooth damage, pain and social/marital conflict) requires intervention by a clinician.
Influence of benthic sediment transport on cold‐water coral bank morphology and growth: the example of the Darwin Mounds, north‐east Atlantic
Authors: WHEELER ANDREW J. , KOZACHENKO MAXIM , MASSON DOUG G. , HUVENNE VEERLE A. I.
Published: June 2008

The Darwin Mounds are small (up to 70 m in diameter), discrete cold‐water coral banks found at c. 950 m water depth in the northern Rockall Trough, north‐east Atlantic. Formerly described in terms of their genesis, the Darwin Mounds are re‐evaluated here in terms of mound growth processes based on 100 and 410 kHz side‐scan sonar data. The side‐scan sonar coverage is divided into a series of acoustic facies representing increasing current speed and sediment transport/erosion from south to north: pockmark facies, ‘mounds within depressions’ facies, Darwin Mound facies, stippled seabed facies and sand wave facies. Mound morphometric changes are quantified and show a south‐to‐north divergence from an inherited morphology, reflecting the outline of coral‐colonized fluid escape structures, to developed, downstream elongated, elevated mound forms. It is postulated that increasing current speeds and bedload sand transport favour mound growth and development by a process of enhanced sand sedimentation within mounds due to current deceleration by frictional drag around coral colonies. Comparisons are made with similar growth processes attributed to comparably sized cold‐water coral mounds in the Porcupine Seabight, offshore Ireland.
Molecular cloning and characterization of OsCDase, a ceramidase enzyme from rice
Authors: Pata Mickael O. , Wu Bill X. , Bielawski Jacek , Xiong Tou Cheu , Hannun Yusuf A. , Ng Carl K.‐Y.
Published: June 2008

Sphingolipids are a structurally diverse group of molecules based on long‐chain sphingoid bases that are found in animal, fungal and plant cells. In contrast to the situation in animals and yeast, much less is known about the spectrum of sphingolipid species in plants and the roles they play in mediating cellular processes. Here, we report the cloning and characterization of a plant ceramidase from rice (Oryza sativa spp. Japonica cv. Nipponbare). Sequence analysis suggests that the rice ceramidase (OsCDase) is similar to mammalian neutral ceramidases. We demonstrate that OsCDase is a bona fide ceramidase by heterologous expression in the yeast double knockout mutant Δypc1Δydc1 that lacks the yeast ceramidases YPC1p and YDC1p. Biochemical characterization of OsCDase showed that it exhibited classical Michaelis–Menten kinetics, with optimum activity between pH 5.7 and 6.0. OsCDase activity was enhanced in the presence of Ca2+, Mg2+, Mn2+ and Zn2+, but inhibited in the presence of Fe2+. OsCDase appears to use ceramide instead of phytoceramide as a substrate. Subcellular localization showed that OsCDase is localized to the endoplasmic reticulum and Golgi, suggesting that these organelles are sites of ceramide metabolism in plants.
The role of LTA4H and ALOX5AP polymorphism in asthma and allergy susceptibility
Authors: Holloway J. W. , Barton S. J. , Holgate S. T. , Rose‐Zerilli M. J. , Sayers I.
Published: June 2008

Background:  Leukotrienes (LTs) have been identified as central mediators in asthma and allergy. Pharmacological inhibition of cysteinyl‐LT activity improves asthma symptoms and control. Accumulating evidence suggests a role for the dihydroxy leukotriene LTB4 in airway disease. LTA4 hydrolase and 5‐lipoxygenase activating protein have key roles in LTB4 production. Single nucleotide polymorphism (SNPs) and haplotypes spanning the LTA4H and ALOX5AP genes have been associated with LTB4 production and myocardial infarction (MI).

Objective:  To assess the contribution of LTA4H and ALOX5AP polymorphism to asthma and allergy susceptibility.

Methods:  Three hundred and forty‐one Caucasian families (two asthmatic siblings) were genotyped for eight SNPs spanning ALOX5AP and five SNPs spanning LTA4H. Association analyses of asthma and related phenotypes (total IgE, atopy, bronchial hyper‐responsiveness, FEV1) were undertaken using the Family Based Association Test.

Results:  Single point analyses identified association (P < 0.05) between SNPs SG13S114, SG13S89, SG13S41 (ALOX5AP), rs1978331 (LTA4H) and asthma and/or related phenotypes. Haplotype analyses using all LTA4H SNPs identified a single key risk haplotype for the development of asthma (P = 0.006) and related phenotypes (P = 0.042–0.005). Haplotype analyses using all ALOX5AP SNPs identified several asthma and atopy risk and protective haplotypes. There was limited correlation with previously identified MI risk haplotypes in both genes. Carriers of both ALOX5AP SG13S41 and LTA4H rs1978331 alleles had an increased risk of developing asthma (OR 2.17, CI 1.41–3.32).

Conclusions:  These data provide evidence for the role of SNPs spanning the ALOX5AP and LTA4H genes in asthma and atopy susceptibility in the Caucasian population and support a role for LTB4 in disease pathogenesis.
Heritable variation in the timing of spermatophore removal, a mechanism of post‐copulatory female choice in crickets
Authors: MAUTZ B. S. , SAKALUK S. K.
Published: June 2008

Female crickets can exert post‐copulatory mating preferences by prematurely removing a male’s spermatophore after copulation, which terminates sperm transfer. Although most models of sexual selection assume that female mating preferences are heritable, there has been little work addressing genetic variation underlying post‐copulatory mate choice. We used a paternal half‐sib design, in which different males were randomly assigned as mates to several females to create half‐sib families, to determine the heritability of spermatophore retention time in female house crickets, Acheta domesticus. There was significant additive genetic variance in the timing of spermatophore removal by females [h2 = 0.50 ± 0.19 (± SE)], suggesting that the timing of spermatophore removal is determined, in part, by the female’s own genotype independent of the quality of her mate. The relatively high heritability of spermatophore retention time may be reflective of the absence of strong selection on this trait, consistent with previous work showing no difference in the fitness of females permitted to freely remove the spermatophore of their mates and those forced to accept complete ejaculates.
Effects of enzyme addition on the nutritive value of broiler diets containing hulled or dehulled Chinese double‐low rapeseed meals
Authors: Fang Z. F. , Liu Z. L. , Dai J. J. , Qian H. Y. , Qi Z. L. , Ma L. B. , Peng J.
Published: June 2008

An in vitro and a feeding trial was conducted to investigate the effect of fibre‐degrading enzymes A (xylanase + β‐glucanase), B (xylanase) and C (xylanase + cellulase) on the nutritive value of broiler diets containing either hulled (22.5% and 23.5% for 4–21 days and 22–42 days of age, respectively) or dehulled (20% and 21.5%) Chinese double‐low rapeseed meals (DLRM). Overall, in vitro digestibility of dry matter (DM) or neutral digestibility fibre (NDF) did not differ (p > 0.05) because of meal types; both crude protein (CP) and NDF digestibility was improved (p < 0.05) because of addition of enzymes B or C either to hulled or dehulled DLRM diets. Birds fed dehulled DLRM diets had a higher (p < 0.05) growth rate, feed efficiency and lower (p < 0.05) feed intake than those fed hulled DLRM diets during the overall phase. Enzyme C addition to dehulled DLRM diets resulted in improved (p < 0.05) growth rate and feed efficiency during 4–21 days of age. Enzymes A and B addition elicited a positive response in feed intake and weight gain (p < 0.05), respectively, but did not affect (p > 0.05) feed efficiency. It would appear that the nutritive value of broiler diets containing Chinese DLRM could be improved by appropriate xylanase‐based enzymes. Responses of broilers to fibre‐degrading enzymes could be highlighted by hull removal of fed DLRM.
Ochratoxin A impairs Nrf2‐dependent gene expression in porcine kidney tubulus cells
Authors: Boesch‐Saadatmandi C. , Wagner A. E. , Graeser A. C. , Hundhausen C. , Wolffram S. , Rimbach G.
Published: June 2008

The mycotoxin, ochratoxin A (OTA), which is produced by Aspergillus and Penicillium subspecies, is frequently present in feedstuffs. Ochratoxin A exhibits a wide range of toxic activities including nephrotoxicity. However, the underlying molecular mechanisms of OTA‐induced cellular nephrotoxicity have yet not been fully elucidated. Nrf2 is a basic leucine zipper transcriptional activator essential for the coordinated transcriptional induction of antioxidant and xenobiotic metabolizing enzymes in the kidney. Therefore, in the present study, the effects of OTA on the nuclear translocation and transactivation of the transcription factor Nrf2 as well as mRNA levels of Nrf2 target genes including glutathione‐S‐transferase and γ‐glutamylcysteinyl synthetase have been studied in cultured porcine kidney tubulus cells (LLC‐PK1). Nrf2 was induced by sulforaphane, a well‐known activator of this transcription factor. Ochratoxin A significantly decreased γ‐glutamylcysteinyl synthetase and glutathione‐S‐transferase mRNA levels in LLC‐PK1 cells. Decreased mRNA levels of γ‐glutamylcysteinyl synthetase and glutathione‐S‐transferase were accompanied by a lowered nuclear translocation and transactivation of Nrf2. Furthermore, OTA also lowered Nrf2 mRNA levels. Current data indicate that OTA nephrotoxicity may be, at least partly, mediated by an Nrf2‐dependent signal transduction pathway.
Diapause induction in Trichogramma embryophagum Htg. (Hym., Trichogrammatidae): the dynamics of thermosensitivity
Authors: Reznik S. Ya. , Vaghina N. P. , Voinovich N. D.
Published: June 2008

It is known that the low temperature is the most important factor inducing the pre‐pupal diapause in Trichogramma species. The position of the thermosensitive period over the life cycle and temporal variation of the degree of responsiveness were investigated in T. embryophagum Htg. by transferring pre‐imaginal stages between ‘neutral’ temperature of 15°C and ‘diapause‐inducing’ temperature of 10°C. Our experiments showed that 6 days long exposure at 10°C significantly increased the percentage of diapausing pre‐pupae when started during rather large part of development: from embryo up to early pre‐pupa. The highest thermosensitivity was recorded during the embryo and the larval stages, with some decrease during the hatching period. Treatments with shorter cold exposures (2–3 days) gave similar results. Even 24 h long exposure at 10°C increased the percentage of diapausing pre‐pupae when applied during egg or early larval stage. Being started at the same stage of development, longer cold exposures caused stronger increase in the percentage of diapausing individuals. The experiments did not reveal any significant daily changes in thermosensitivity: at 12 : 12 h light : dark, larvae subjected to the low temperature during six photophases showed practically the same percentage of diapausing individuals as those subjected to the low temperature during six scotophases, and as those subjected to the 3 days long uninterrupted cold exposure. Hence, in natural conditions even occasional short‐term cold periods could be accumulated.
Reproductive output in a Mediterranean population of the homosclerophoridCorticium candelabrum(Porifera, Demospongiae), with notes on the ultrastructure and behavior of the larva
Authors: Maldonado Manuel , Riesgo Ana
Published: June 2008

The reproductive output of sponges possessing small elusive larvae remains little investigated, even though they are relevant community members in many cases. This makes difficult to understand their life cycles and population dynamics. In this study we monitored the dynamics of embryogenesis and larval output in a north‐western Mediterranean population of the sublittoral demospongeCorticium candelabrum. The sponge was moderately abundant, mostly concentrated at overhangs and shaded walls. The population was dominated by relatively small individuals, averaging 1.26 cm3in size. About 89% of individuals in the population produced gametes. Body size did not preclude reproduction, as gametes and embryos occurred in sponges ranging from 0.24 to 13.5 cm3in size. On average, individuals produced 21.3 ± 12 embryos per mm3of sponge tissue, but inter‐annual variability in the reproductive effort was noticed. Larval release was asynchronous at both the individual and the population level, with sponges releasing larvae from early July to August. A yearly production was estimated of about half a million larvae per m2of rocky bottom at those sites where this species occurs. Living larvae measured 340 ± 25 μm in length, were bulb‐shaped, entirely ciliated, and swam with a clockwise rotation. They were hollow, with an internal cavity limited by a monolayered epithelium of columnar cells. All larval cells had a distal cilium arising from a principal centriole connected to a basal foot. There was an orthogonal accessory centriole giving rise to a short striated rootlet (21‐nm periodicity band) that ran between the nucleus and the Golgi apparatus. This is the first reported case in Porifera of a ciliary rootlet derived from an accessory centriole, an uncommon arrangement also found in choanoflagellates. Despite sharing many features, cells of the anterior, medial, and posterior larval region were easily distinguishable from each other because of differences in their internal organization and yolk content. At the distal and proximal poles of all cells, the plasmalemma thickened to produce special junctions and seal the larval epithelium. Distal junctions were septate. The larval cavity was filled with vertically transmitted symbiotic bacteria and collagen fibrils. Collagen condensed below the larval epithelium at different degrees, but was absent in some areas, raising doubts about the occurrence of a true basement membrane. Larvae showed neither recognizable photoreceptory organelles nor evident behavioral responses to experimental light cues. Because the high larval production does not mirror adult abundance in the community, we suspect high levels of larval losses during dispersal and elevated impact of post‐settlement mortality as the probable result of unselective settlement at unsuitable sites.
The ecology and phylogeny of cyanobacterial symbionts in sponges
Authors: Usher Kayley M.
Published: June 2008

Cyanobacteria have flexible photosynthetic apparatus that allows them to utilise light at very low levels, making them ideal symbionts for a wide range of organisms. Sponge associations with cyanobacteria are common in all areas of the world, but little is known about them. Recent research has revealed new cyanobacterial symbionts that may be host specific and two major clades, ‘Candidatus Synechococcus spongiarum’ and Oscillatoria spongeliae, that occur in widely separated geographic locations in unrelated sponge hosts. These clades may represent a cluster of closely related symbiont species, or may be single species that are maintained by periods of horizontal transmission over large distances. Erroneous assumptions regarding the importance of cyanobacterial symbionts to the survival of individual sponges or species may arise from cyanosponges being deemed to be phototrophic or mixotrophic without studies of their photophysiology. This review brings together recent and past research on cyanobacterial associations with sponges, including their biogeography, phylogeny, host specificity, and ecology.
Novel use of dexmedetomidine in a patient with pulmonary hypertension
Authors: NATHAN ARUNA T. , MARINO BRADLEY S. , HANNA BRIAN , NICOLSON SUSAN C.
Published: June 2008

The presence of pulmonary arterial hypertension (PAH) is a significant predictor of major perioperative cardiovascular complications in patients undergoing cardiac diagnostic or interventional procedure or non cardiac surgery under sedation and/or anesthesia. Factors that precipitate a pulmonary hypertensive crisis include hypoxia, hypercarbia, acidosis, hypothermia, pain and airway manipulations. Pain management is challenging in patients with significant PAH. We report the use of dexmedetomidine for sedation and analgesia in a 16 year old patient with significant pulmonary hypertension, pneumonia and impending cardiorespiratory failure. This resulted in avoidance of endotracheal intubation and positive pressure ventilation, with subsequent recovery to discharge home.
Intraoperative extracorporeal membrane oxygenation and survival of pediatric patients undergoing repair of congenital heart disease
Authors: FLICK RANDALL P. , SPRUNG JURAJ , GLEICH STEPHEN J. , BARNES ROXANN D. , WARNER DAVID O. , DEARANI JOSEPH A. , SCOTT PHILLIP D. , HANSON ANDREW C. , SCHROEDER DARRELL R. , SCHEARS GREGORY J.
Published: June 2008

Background:  We studied the association between the introduction of extracorporeal membrane oxygenation (ECMO) into routine practice and the survival of children who failed weaning from cardiopulmonary bypass (CPB). We compare two periods, before formal introduction of ECMO in our institution (1993–1999, pre‐ECMO era) and after ECMO became a formalized program (2000–2006, ECMO era).

Methods:  Retrospective review of Mayo Clinic Database between 1993 and 2006 for outcomes of patients <18 years old who required ECMO during repair of congenital heart malformations.

Results:  Thirty‐five children during ECMO era received intraoperative ECMO, and 17 (54%) survived to hospital discharge. The frequency of ECMO use was the highest in neonates, therefore, this was the only subcohort of pediatric patients that allowed comparison of survival between the pre‐ECMO and ECMO eras. When compared to pre‐ECMO era, neonatal survival increased during ECMO era (P = 0.043). ECMO was mostly used in neonates with higher complexity of cardiac defects undergoing more complex repairs, and the overall improvement of survival was primarily due to better survival of these patients. During pre‐ECMO era, survival was lower in patients with higher risk (P = 0.001). However, during ECMO era, no difference in survival was observed across assigned risk groups (P = 0.658).

Conclusions:  The availability of ECMO for neonates failing to wean from CPB was associated with improved survival, especially in children undergoing repair of the most complex congenital heart malformations. After introduction of ECMO, survival improved and no longer depended upon the complexity of surgical repair.
Ultrasound‐guided supraclavicular vs infraclavicular brachial plexus blocks in children
Authors: DE JOSÉ MARÍA BELÉN , BANÚS ESTER , NAVARRO EGEA MONTSE , SERRANO SILVIA , PERELLÓ MARINA , MABROK MAGED
Published: June 2008

Background:  Supraclavicular brachial plexus blocks are not common in children because of risk of pneumothorax. However, infraclavicular brachial plexus blocks have been described in paediatric patients both with nerve stimulation and ultrasound (US)‐guidance. US‐guidance reduces the risk of complications in supraclavicular brachial plexus blocks in adults.

Objective:  To compare the success rate, complications and time of performance of US‐guided supraclavicular vs infraclavicular brachial plexus blocks in children.

Material and methods:  Eighty children, 5–15 years old, scheduled for upper limb surgery were divided into two randomized groups: group S (supraclavicular), n = 40, and group I (infraclavicular), n = 40. All blocks performed were exclusively US‐guided, by a senior anaesthesiologist with at least 6 months of experience in US‐guided blocks. For supraclavicular blocks the probe was placed in coronal‐oblique‐plane in the supraclavicular fossa and the puncture was in‐plane (IP) from lateral to medial. For infraclavicular blocks the probe was placed parallel and below the clavicle and the puncture was out‐of‐plane. Ropivacaine 0.5% was administered up to a maximum of 0.5 ml·kg−1 until appropriate US‐guided‐spread was achieved. Block duration and volumes of ropivacaine used (mean±1SD) in the supraclavicular approach were recorded. Success rate (mean ± 1 SD, 95%confidence interval), complications rate and time to perform the block (two‐tailed Student′s test) were recorded both for supraclavicular and infraclavicular approaches.

Results:  In the US‐guided supraclavicular brachial plexus blocks, the duration of the sensory block was 6.5 ± 2 h and of the motor block was 4 ± 1 h. The volume of ropivacaine used in this group was 6 ± 2 ml. In group I, 88% of blocks achieved surgical anaesthesia without any supplemental analgesia compared with 95% in group S (P = 0.39; difference=7%; 95% CI: −10% to 24%). Failures in group I were because of arterial puncture and insufficient ulnar or radial sensory block. Failures in group S were because of insufficient ulnar sensory block. No pneumothorax or Horner’s syndrome was recorded in either group. The mean time (SD) to perform the block was in group I: 13 min (range 5–16) and in group S: 9 min (range 7–12); the 95% CI for this difference was 2–6 min and was statistically significant (P < 0.05).

Conclusions:  (i) Ultrasound‐guided supraclavicular and infraclavicular brachial plexus blocks are effective in children. (ii) There has been no pneumothorax in 40 US‐guided supraclavicular brachial plexus blocks performed by anaesthesiologists already trained in US‐guided regional anaesthesia using an IP technique in children ≥5 years old. (iii) In this study, the supraclavicular approach of the brachial plexus was faster to perform than the infraclavicular one.
Optimum management of type 2 diabetes – timely introduction, optimization and intensification of basal insulin
Authors: Dailey G.
Published: June 2008

The natural progression of type 2 diabetes mellitus (T2DM) requires continuing medical care, early insulin intensification and patient self‐management education to reduce the risk of long‐term complications, including microvascular and macrovascular complications. However, too few people are on insulin, and all too commonly have poor glycaemic control. This paradigm significantly increases the risk for long‐term complications. It is becoming increasingly apparent that the early introduction of basal insulin, such as insulin glargine, is essential to provide clinically important improvements in glycaemic control. In this review, we discuss the rationale for the earlier insulinization in T2DM in order to reach and maintain treatment targets and to provide further support for the recent American Diabetes Association and European Association for the Study of Diabetes consensus statement.
Reaching glycaemic targets while minimizing hypoglycaemia in insulin‐treated type 2 diabetes patients
Authors: Mathieu C. , Robbrecht S.
Published: June 2008

Type 2 diabetes mellitus (T2DM) is a progressive disease characterized by both insulin resistance and β‐cell failure, resulting in a decline in insulin secretion and increased blood glucose levels. By the time T2DM is clinically diagnosed, only 50% of normal β‐cell function remains, leading to altered control of fasting and/or postprandial glucose. The aim of this review is to summarize the options for introduction of basal insulin, in particular insulin glargine, and the advantages and disadvantages of using insulin glargine vs. alternative insulins or vs. oral agents. Overall, the studies included in this review show that insulin glargine is associated with a lower risk of hypoglycaemia vs. both neutral protamine Hagedorn insulin and premixed insulin formulations, alongside clinically important improvements in glycaemic control. Furthermore, insulin glargine is associated with greater improvements in glycaemic control vs. intensification of oral therapy. Thus, insulin glargine should be a preferred option when starting insulin therapy for people with T2DM.
Improving treatment satisfaction and other patient‐reported outcomes in people with type 2 diabetes: the role of once‐daily insulin glargine
Authors: Bradley C. , Gilbride C. J. B.
Published: June 2008

Insulin therapy becomes essential for many people with type 2 diabetes. After starting insulin, people with diabetes that is poorly controlled with oral agents typically report improved well‐being and treatment satisfaction. However, healthcare professionals and people with type 2 diabetes are often reluctant to begin insulin treatment, citing concerns such as time/resources needed to educate patients, increased risks of hypoglycaemia and fear of injections, which lead them to focus on intensifying conventional oral therapy. Insulin glargine, which offers people with diabetes a once‐a‐day injection regimen with low risk of hypoglycaemia, is more likely to overcome such initial barriers than other more complex insulin regimens. Once‐daily insulin glargine, in combination with modern glucose‐dependent oral agents that do not need to be chased with food to prevent hypoglycaemia, does not require the fixed mealtimes and set amounts of carbohydrates necessary with twice‐daily injection mixes and older sulphonylureas. We know that it is such dietary restrictions that cause the most damage to quality of life (QoL). To avoid damaging QoL unnecessarily and to ensure optimal satisfaction with treatment, it is important to evaluate the effects of treatment on QoL, treatment satisfaction and other patient‐reported outcomes (PROs) using questionnaires validated for this purpose, such as the widely used Diabetes Treatment Satisfaction Questionnaire and the Audit of Diabetes‐Dependent Quality of Life measure. A systematic electronic literature search identified reports of studies evaluating PROs associated with insulin glargine in comparison with other treatments. The studies show that insulin glargine is usually associated with greater improvements in treatment satisfaction and other PROs compared with intensifying oral therapy or alternative insulin regimens.