bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate change in size-structured ecosystems
Authors: Brose Ulrich , Dunne Jennifer A. , Montoya Jose M. , Petchey Owen L. , Schneider Florian D. , Jacob Ute
Published: September 2012

One important aspect of climate change is the increase in average temperature, which will not only have direct physiological effects on all species but also indirectly modifies abundances, interaction strengths, food-web topologies, community stability and functioning. In this theme issue, we highlight a novel pathway through which warming indirectly affects ecological communities: by changing their size structure (i.e. the body-size distributions). Warming can shift these distributions towards dominance of small- over large-bodied species. The conceptual, theoretical and empirical research described in this issue, in sum, suggests that effects of temperature may be dominated by changes in size structure, with relatively weak direct effects. For example, temperature effects via size structure have implications for top-down and bottom-up control in ecosystems and may ultimately yield novel communities. Moreover, scaling up effects of temperature and body size from physiology to the levels of populations, communities and ecosystems may provide a crucially important mechanistic approach for forecasting future consequences of global warming.
Trophic cascades, invasive species and body-size hierarchies interactively modulate climate change responses of ecotonal temperate–boreal forest
Authors: Frelich Lee E. , Peterson Rolf O. , Dovčiak Martin , Reich Peter B. , Vucetich John A. , Eisenhauer Nico
Published: September 2012

As the climate warms, boreal tree species are expected to be gradually replaced by temperate species within the southern boreal forest. Warming will be accompanied by changes in above- and below-ground consumers: large moose (Alces alces) replaced by smaller deer (Odocoileus virginianus) above-ground, and small detritivores replaced by larger exotic earthworms below-ground. These shifts may induce a cascade of ecological impacts across trophic levels that could alter the boreal to temperate forest transition. Deer are more likely to browse saplings of temperate tree species, and European earthworms favour seedlings of boreal tree species more than temperate species, potentially hindering the ability of temperate tree species to expand northwards. We hypothesize that warming-induced changes in consumers will lead to novel plant communities by changing the filter on plant species success, and that above- and below-ground cascades of trophic interactions will allow boreal tree species to persist during early phases of warming, leading to an abrupt change at a later time. The synthesis of evidence suggests that consumers can modify the climate change-induced transition of ecosystems.
Potential for climate effects on the size-structure of host–parasitoid indirect interaction networks
Authors: Henri Dominic C. , Seager David , Weller Tiffany , van Veen F. J. Frank
Published: September 2012

Communities of insect herbivores are thought to be structured mainly by indirect processes mediated by shared natural enemies, such as apparent competition. In host–parasitoid interaction networks, overlap in natural enemy communities between any pair of host species depends on the realized niches of parasitoids, which ultimately depend on the foraging decisions of individuals. Optimal foraging theory predicts that egg-limited parasitoid females should reject small hosts in favour of future opportunities to oviposit in larger hosts, while time-limited parasitoids are expected to optimize oviposition rate regardless of host size. The degree to which parasitoids are time- or egg-limited depends in part on weather conditions, as this determines the proportion of an individual's lifespan that is available to foraging. Using a 10-year time series of monthly quantitative host–parasitoid webs, we present evidence for host-size-based electivity and sex allocation in the common secondary parasitoid
Asaphes vulgaris.
We argue that this electivity leads to body-size-dependent asymmetry in apparent competition among hosts and we discuss how changing weather patterns, as a result of climate change, may impact foraging behaviour and thereby the size-structure and dynamics of host–parasitoid indirect interaction networks.
Climate-induced changes in bottom-up and top-down processes independently alter a marine ecosystem
Authors: Jochum Malte , Schneider Florian D. , Crowe Tasman P. , Brose Ulrich , O'Gorman Eoin J.
Published: September 2012

Climate change has complex structural impacts on coastal ecosystems. Global warming is linked to a widespread decline in body size, whereas increased flood frequency can amplify nutrient enrichment through enhanced run-off. Altered population body-size structure represents a disruption in top-down control, whereas eutrophication embodies a change in bottom-up forcing. These processes are typically studied in isolation and little is known about their potential interactive effects. Here, we present the results of anin situexperiment examining the combined effects of top-down and bottom-up forces on the structure of a coastal marine community. Reduced average body mass of the top predator (the shore crab,Carcinus maenas) and nutrient enrichment combined additively to alter mean community body mass. Nutrient enrichment increased species richness and overall density of organisms. Reduced top-predator body mass increased community biomass. Additionally, we found evidence for an allometrically induced trophic cascade. Here, the reduction in top-predator body mass enabled greater biomass of intermediate fish predators within the mesocosms. This, in turn, suppressed key micrograzers, which led to an overall increase in microalgal biomass. This response highlights the possibility for climate-induced trophic cascades, driven by altered size structure of populations, rather than species extinction.
Climate change impacts on body size and food web structure on mountain ecosystems
Authors: Lurgi Miguel , López Bernat C. , Montoya José M.
Published: September 2012

The current distribution of climatic conditions will be rearranged on the globe. To survive, species will have to keep pace with climates as they move. Mountains are among the most affected regions owing to both climate and land-use change. Here, we explore the effects of climate change in the vertebrate food web of the Pyrenees. We investigate elevation range expansions between two time-periods illustrative of warming conditions, to assess: (i) the taxonomic composition of range expanders; (ii) changes in food web properties such as the distribution of links per species and community size-structure; and (iii) what are the specific traits of range expanders that set them apart from the other species in the community—in particular, body mass, diet generalism, vulnerability and trophic position within the food web. We found an upward expansion of species at all elevations, which was not even for all taxonomic groups and trophic positions. At low and intermediate elevations, predator : prey mass ratios were significantly reduced. Expanders were larger, had fewer predators and were, in general, more specialists. Our study shows that elevation range expansions as climate warms have important and predictable impacts on the structure and size distribution of food webs across space.
Climate change effects on macrofaunal litter decomposition: the interplay of temperature, body masses and stoichiometry
Authors: Ott David , Rall Björn C. , Brose Ulrich
Published: September 2012

Macrofauna invertebrates of forest floors provide important functions in the decomposition process of soil organic matter, which is affected by the nutrient stoichiometry of the leaf litter. Climate change effects on forest ecosystems include warming and decreasing litter quality (e.g. higher C : nutrient ratios) induced by higher atmospheric CO
2
concentrations. While litter-bag experiments unravelled separate effects, a mechanistic understanding of how interactions between temperature and litter stoichiometry are driving decomposition rates is lacking. In a laboratory experiment, we filled this void by quantifying decomposer consumption rates analogous to predator–prey functional responses that include the mechanistic parameters handling time and attack rate. Systematically, we varied the body masses of isopods, the environmental temperature and the resource between poor (hornbeam) and good quality (ash). We found that attack rates increased and handling times decreased (i) with body masses and (ii) temperature. Interestingly, these relationships interacted with litter quality: small isopods possibly avoided the poorer resource, whereas large isopods exhibited increased, compensatory feeding of the poorer resource, which may be explained by their higher metabolic demands. The combination of metabolic theory and ecological stoichiometry provided critically important mechanistic insights into how warming and varying litter quality may modify macrofaunal decomposition rates.
The role of temperature and dispersal in moss-microarthropod community assembly after a catastrophic event
Authors: Perdomo Giselle , Sunnucks Paul , Thompson Ross M.
Published: September 2012

There is a clear crisis in the maintenance of biodiversity. It has been generated by a multitude of factors, notably habitat loss, now compounded by the effects of climate change. Predicted changes in climate include increased severity and frequency of extreme climatic events. To manage landscapes, an understanding of the processes that allow recovery from these extreme events is required. Understanding these landscape-scale processes of community assembly and disassembly is hindered by the large scales at which they operate. Model systems provide a means of studying landscape scale processes at tractable scales. Here, we assess the combined effects of temperature and habitat-patch isolation on assembly of naturally diverse moss microarthropod communities after a high-temperature event. We show that community assembly depends on temperature and on degree of habitat isolation. Heated communities were heavily dominated in abundance by two species, one of them relatively large. The resulting size-structure is unlike that seen in the field. Community composition in habitat fragments appears also to have been influenced by the source pool of recolonizing fauna. Our results highlight the value of dispersal in disturbed landscapes and the potential for habitat connectivity to buffer communities from the effects of climate change.
Universal temperature and body-mass scaling of feeding rates
Authors: Rall Björn C. , Brose Ulrich , Hartvig Martin , Kalinkat Gregor , Schwarzmüller Florian , Vucic-Pestic Olivera , Petchey Owen L.
Published: September 2012

Knowledge of feeding rates is the basis to understand interaction strength and subsequently the stability of ecosystems and biodiversity. Feeding rates, as all biological rates, depend on consumer and resource body masses and environmental temperature. Despite five decades of research on functional responses as quantitative models of feeding rates, a unifying framework of how they scale with body masses and temperature is still lacking. This is perplexing, considering that the strength of functional responses (i.e. interaction strengths) is crucially important for the stability of simple consumer–resource systems and the persistence, sustainability and biodiversity of complex communities. Here, we present the largest currently available database on functional response parameters and their scaling with body mass and temperature. Moreover, these data are integrated across ecosystems and metabolic types of species. Surprisingly, we found general temperature dependencies that differed from the Arrhenius terms predicted by metabolic models. Additionally, the body-mass-scaling relationships were more complex than expected and differed across ecosystems and metabolic types. At local scales (taxonomically narrow groups of consumer–resource pairs), we found hump-shaped deviations from the temperature and body-mass-scaling relationships. Despite the complexity of our results, these body-mass- and temperature-scaling models remain useful as a mechanistic basis for predicting the consequences of warming for interaction strengths, population dynamics and network stability across communities differing in their size structure.
Idiosyncratic species effects confound size-based predictions of responses to climate change
Authors: Twomey Marion , Brodte Eva , Jacob Ute , Brose Ulrich , Crowe Tasman P. , Emmerson Mark C.
Published: September 2012

Understanding and predicting the consequences of warming for complex ecosystems and indeed individual species remains a major ecological challenge. Here, we investigated the effect of increased seawater temperatures on the metabolic and consumption rates of five distinct marine species. The experimental species reflected different trophic positions within a typical benthic East Atlantic food web, and included a herbivorous gastropod, a scavenging decapod, a predatory echinoderm, a decapod and a benthic-feeding fish. We examined the metabolism–body mass and consumption–body mass scaling for each species, and assessed changes in their consumption efficiencies. Our results indicate that body mass and temperature effects on metabolism were inconsistent across species and that some species were unable to meet metabolic demand at higher temperatures, thus highlighting the vulnerability of individual species to warming. While body size explains a large proportion of the variation in species' physiological responses to warming, it is clear that idiosyncratic species responses, irrespective of body size, complicate predictions of population and ecosystem level response to future scenarios of climate change.
Measuring and mapping technology‐fields correlation and its application on China's nanotechnology
Authors: Luan Chunjuan , Wang Xiuping
Published: September 2012

Purpose

The purpose of this paper is to help China's science and technology (abbr. as S&T) managers and related policy makers to allocate S&T human resources, optimize organizational systems of laboratories, design and plan some grant projects, and manage other S&T‐related work in the field of nanoscience and nanotechnology, by measuring and mapping of technology‐fields correlation, with nanotechnology as an example.

Design/methodology/approach

Methodologies such as co‐occurrence analysis, correlation analysis, multidimensional scaling (abbr. as MDS) analysis, dendrogram (tree‐like) analysis, etc. are employed to measure and map technology‐fields correlation.

Findings

It is found that the exact relevance degree of any two technology‐fields exists among the top 33 technology‐fields with high frequencies. There are three industrial clusters in Multidimentional Scaling View, that is, nanotechnology used in bio‐medical industry, nanotechnology used in new material industry and nanotechnology used in electronic industry. Hierarchy of any two technology‐fields can be found out in the dendrogram view of the top 33 technology‐fields.

Originality/value

This paper could be of great significance to China's S&T managers and related policy makers, especially in the area of nanotechnology, in selecting and managing generic technology and the findings in this paper can be applied in some other fields of science and technology management in China. Both technology‐fields correlation analysis and MDS and dendrogram view analysis could benefit China's policy makers in managing nanotechnology research and development activities.
Seed germination from lowland tapir (Tapirus terrestris) fecal samples collected during the dry season in the northern Brazilian Amazon
Authors: BARCELOS Adriana Renata , BOBROWIEC Paulo Estefano D. , SANAIOTTI Tânia Margarete , GRIBEL Rogério
Published: September 2012

This study evaluated the potential of lowland tapirs as seed dispersers in the northern Brazilian Amazon. The study analyzed the viability of seeds after passage through the gut. Fecal samples were collected from 6 different vegetation physiognomies in Viruá National Park during the dry season. The samples were then kept in a greenhouse for 16 months to allow the seeds to germinate. The seedling species were identified and classified according to the type of fruit, plant habit, seed size and type of ingestion. Of the 111 fecal samples, 94 (84.7%) had viable seeds of 75 species. Melastomataceae was the most frequent family with viable seeds in the fecal samples (69.1% of samples, N= 18 species). The data suggest that the importance of the lowland tapirs as dispersers is not restricted to the species consumed actively by frugivory but also extends to species accidentally consumed during browsing. The occurrence of both large and small viable seeds in the fecal samples as well as a number of large drupes, which probably cannot be transported via endozoochory by any other animal species, provide evidence of the ecological importance of lowland tapirs to the dynamics of the forest‐campinarana vegetation mosaic in the region.
Biological consequences of global change for birds
Authors: MØLLER Anders Pape
Published: September 2012

Climate is currently changing at an unprecedented rate; so also human exploitation is rapidly changing the Earth for agriculture, forestry, fisheries and urbanization. In addition, pollution has affected even the most remote ecosystems, as has the omnipresence of humans, with consequences in particular for animals that keep a safe distance from potential predators, including human beings. Importantly, all of these changes are occurring simultaneously, with increasing intensity, and further deterioration in both the short and the long‐term is predicted. While the consequences of these components of global change are relatively well studied on their own, the effects of their interactions, such as the combined effects of climate change and agriculture, or the combined effects of agriculture through nutrient leakage to freshwater and marine ecosystems and fisheries, and the effects of climate change and urbanization, are poorly understood. Here, I provide a brief overview of the effects of climate change on phenology, diversity, abundance, interspecific interactions and population dynamics of birds. I address whether these effects of changing temperatures are direct, or indirect through effects of climate change on the phenology, distribution or abundance of food, parasites and predators. Finally, I review interactions between different components of global change.
Gastric exocrine and endocrine cell morphology under prolonged acid inhibition therapy: results of a 5‐year follow‐up in the LOTUS trial
Authors: Fiocca R. , Mastracci L. , Attwood S. E. , Ell C. , Galmiche J.‐P. , Hatlebakk J. , Bärthel A. , Långström G. , Lind T. , Lundell L. ,   the LOTUS trial collaborators
Published: September 2012

Background

Sustained acid inhibition with PPI stimulates gastrin secretion, exerting a proliferative drive on enterochromaffin‐like cells (ECL cells) of the oxyntic mucosa. It may also accelerate development of gastric gland atrophy in Helicobacter pylori‐infected individuals.

Aims

To evaluate gastric exocrine and endocrine cell changes in GERD patients randomised to laparoscopic antireflux surgery (LARS, n = 288) or long‐term (5 years) esomeprazole (ESO) treatment (n = 266).

Methods

Antral and corpus biopsies were taken at endoscopy and serum gastrin and chromogranin A levels were assayed, at baseline and after 1, 3 and 5 years’ therapy.

Results

Biopsies were available at each time point for 158 LARS patients and 180 ESO patients. In H. pylori‐infected subjects, antral mucosal inflammation and activity improved significantly (P < 0.001) and stabilised after 3 years on esomeprazole while no change in inflammation was observed after LARS. Oxyntic mucosal inflammation and activity remained stable on esomeprazole but decreased slightly over time after LARS. Neither intestinal metaplasia nor atrophy developed in the oxyntic mucosa. ECL cell density increased significantly after ESO (P < 0.001), corresponding with an increase in circulating gastrin and chromogranin A. After LARS, there was a significant decrease in ECL cell density (P < 0.05), accompanied by a marginal decrease in gastrin and chromogranin.

Conclusions

Antral gastritis improved in H. pylori‐infected GERD patients after 5 years on esomeprazole, with little change in laparoscopic antireflux surgery patients, who acted as a control. Despite a continued proliferative drive on enterochromaffin‐like cells during esomeprazole treatment, no dysplastic or neoplastic lesions were found and no safety concerns were raised. NCT 00251927.
A methodological approach for assessing the effects of disturbance factors on the conservation status of Mediterranean coastal dune systems
Authors: Attorre Fabio , Maggini Alberto , Di Traglia Mario , De Sanctis Michele , Vitale Marcello
Published: September 2012

Questions

How can the conservation status of Mediterranean coastal dunes be assessed? What is the effect of disturbance factors on it?

Location

Tyrrhenian coast of Central Italy.

Methods

Vegetation relevés along 164 transects lying perpendicular to the shoreline along the Tyrrhenian coast of Central Italy were used to identify the presence of dune habitats by means of TWINSPAN classification and detrended correspondence analysis. Multiple correspondence analysis was used to analyse relationship between habitats and disturbance factors. The resulting Burt's table was used to build an index (habitat‐disturbance, HDi) for analysing this relationship. Based on HDi values, a correspondence analysis (CA) between presence/absence of habitats and disturbances was performed. The overall plant species diversity of dunes was measured with NHDUNE, a modified version of the Shannon index. Multi‐way ANOVA procedure was used to investigate effect of single disturbance factors and their interactive effect on NHDUNE.

Results

Classification and ordination procedures identified four sequential habitats moving from the shoreline to inland: annual vegetation on drift lines characterized by Cakile maritima; embryonic shifting dunes dominated by Elymus farctus; shifting dunes with Ammophila arenaria subsp. australis; back dune grasslands characterized by Ononis variegata. CA showed that disturbance factors influence dune habitats differently. In particular, the Cakile community had a negative relationship with beach tourism and mechanical cleaning; the Elymus community had a positive relationship with beach tourism and mechanical cleaning and a negative relationship with erosion and bathing establishments; the Ammophila community had a negative relationship with mechanical cleaning and bathing establishments and a positive relationship with dune cross‐trampling; and the Ononis community had a negative relationship with bathing establishment. According to multi‐way ANOVA, single disturbance factors can have different effects on plant species diversity as measured by NHDUNE. However, the overall effect is negative, with erosion as a single factor and the combination of mechanical cleaning and bathing establishments significantly lowering the plant diversity of coastal dune systems.

Conclusions

The proposed method allows a fast and replicable evaluation of the effects of disturbance factors on the conservation status of Mediterranean coastal dunes, providing the information necessary for development of conservation strategies focusing on a single habitat or on the overall dune system.
Window of Opportunity for Neuroprotection with an Antioxidant, Allene Oxide Synthase, after Hypoxia–Ischemia in Adult Male Rats
Authors: Mathai Sam , Gunn Alistair J. , Backhaus Ralph Andrew , Guan Jian
Published: September 2012

Aims

Oxidative stress is an early event in the cascade leading in neuronal damage after hypoxic–ischemic (HI) brain injury. In the present study, we examined the dose response and window of opportunity for neuroprotection after HI injury with Allene Oxide Synthase (AOS), an anti‐oxidative enzyme of the member of cytochrome P450 family.

Methods

Adult male rats received intra‐cerebro‐ventricular infusions of either saline (vehicle) or AOS (1 μg or 10 μg or 100 μg per rat, intracerebroventricular n = 16 all groups) either 45 min or 3 h after unilateral HI brain injury. Brains were collected 5 days later. The extent of brain damage, neuronal survival, apoptosis, and glial reactions were assessed in the striatum, hippocampus, and cortex.

Results

Allene Oxide Synthase was associated with reduced neuronal damage scores when given 45 min, but not 3 h, after HI injury (P < 0.0001) in all brain regions. AOS treatment (10 μg) improved neuronal survival in the striatum, cortex, and hippocampus (P < 0.05, P < 0.001) and reduced the microglia reaction (P < 0.05) and numbers of caspase‐3‐positive cells in the hippocampus (P < 0.01).

Conclusions

Early blockade of oxidative stress after HI injury reduces inflammatory response, neuronal necrosis, and apoptosis. The neuroprotective effects of AOS were time of administration‐dependent suggesting a relatively restricted window of opportunity for acute brain injury.
Cerebral oxygen saturation evaluated by near‐infrared time‐resolved spectroscopy (TRS) in pregnant women during caesarean section – a promising new method of maternal monitoring
Authors: Yamazaki Kaori , Suzuki Kazunao , Itoh Hiroaki , Muramatsu Keiko , Nagahashi Kotomi , Tamura Naoaki , Uchida Toshiyuki , Sugihara Kazuhiro , Maeda Hideki , Kanayama Naohiro
Published: September 2012

Time‐resolved spectroscopy (TRS‐20) measures tissue oxygen saturation (%) by evaluating the absolute concentrations of oxygenated, deoxygenated and total haemoglobin based on measurement of the transit time of individual photons through a tissue of interest. We measured tissue oxygen saturation in the prefrontal lobes of the brain by TRS‐20 in eighteen pregnant women during caesarean section. In a case of placenta previa, massive bleeding immediately decreased cerebral oxygen saturation from 67·2% to 54·2%, but did not alter peripheral tissue oxygenation as measured by pulse oximetry. Four cases of pre‐eclampsia revealed chronic changes in elevated base levels of cerebral oxygen saturation, though peripheral oxygen saturation was similar to that in normotensive pregnant women. Average cerebral oxygen saturation in the cases of pre‐eclampsia before the introduction of anaesthesia was 73·6 ± 4·4 (SD)% (n = 4), significantly higher than in normotensive pregnant women, 67·2 ± 4·3% (n = 13, P<0·05). Z‐scores of cerebral oxygen saturation prior to anaesthesia positively correlated with those of systolic or diastolic blood pressure. TRS‐20 could detect acute as well as chronic changes in brain oxygen saturation in response to pregnancy‐associated complications.
Comparison of the effects of esomeprazole and fundoplication on airway responsiveness in patients with gastro‐oesophageal reflux disease
Authors: Kiljander Toni , Rantanen Tuomo , Kellokumpu Ilmo , Kööbi Tiit , Lammi Lauri , Nieminen Markku , Poussa Tuija , Ranta Arto , Saarelainen Seppo , Salminen Paulina
Published: September 2012

Introduction

Gastro‐oesophageal reflux disease (GORD) is suggested to cause or aggravate several respiratory conditions. Studies with proton pump inhibitors have resulted in only minor improvements in pulmonary outcomes in patients with GORD. It has been speculated that operative treatment of GORD might be more efficient as it also diminishes non‐acidic reflux.

Objectives

To compare the effects of esomeprazole 40 mg bid and fundoplication on airway responsiveness, forced expiratory volume in 1 s (FEV1), exhaled nitric oxide (NO) and respiratory symptoms in patients with moderate‐to‐severe GORD.

Methods

Sixty‐nine GORD patients had methacholine inhalation challenge performed on them, and FEV1, exhaled NO and respiratory symptoms were measured at baseline, after a 3‐month treatment with esomeprazole and 3 months after fundoplication. Primary outcome variable was dose‐response slope (DRS), i.e. decline in FEV1 during methacholine challenge divided with the amount of methacholine administered (%/μmol). Pre‐defined subgroup analysis was performed among those with concomitant asthma (n = 12).

Results

There was no improvement in DRS, FEV1 or exhaled NO after esomeprazole treatment or fundoplication. Cough and dyspnoea measured with visual analog scale improved with esomeprazole treatment (P < 0.001), and further after fundoplication (P < 0.001). Among those with concomitant asthma, significant improvements in St George Respiratory Questionnaire (SGRQ) scores could be seen after fundoplication.

Conclusions

Neither esomeprazole treatment nor fundoplication diminishes airway responsiveness or exhaled NO, or improves FEV1 in patients with GORD. Improvements in respiratory symptoms and SGRQ scores after GORD treatments could be detected. However, as this was not a placebo‐controlled study, the findings in these secondary endpoints should not be emphasised. ClinicalTrials.cov: NCT00994708.
The first steps towards unifying concepts in invasion ecology were made one hundred years ago: revisiting the work of the Swiss botanist Albert Thellung
Authors: Kowarik Ingo , Pyšek Petr
Published: September 2012

Aim

Biological invasions are a major threat to biodiversity, and The ecology of invasions by animals and plants by Charles Elton (1958) is often recognized as the starting point for modern invasion research. Yet there were predecessors in invasion research whose contribution to the development of ideas and concepts in this field is often underestimated. To contribute to a balanced perception of pioneers in invasion research, we retrace the work of the Swiss botanist Albert Thellung (1881–1928) whose main work, La flore adventice de Montpellier, appeared 100 years ago, in 1912, and illustrate how his ideas contributed to the current state of the art in the fields of invasion science and biogeography.

Location

None.

Methods

We discuss conceptual approaches in the invasion‐related work by Albert Thellung.

Results

Thellung's early work covered topics that are still central to widely used invasion frameworks. He promoted concepts to classify alien species (degree of naturalization, introduction pathways and time period of introduction) and adopted these systematically at a regional scale in his alien flora of Montpellier, comprising 800 non‐native species. He introduced an exact population‐based definition of naturalization, with links to environmental barriers, and elaborated the first assessment of pathway efficiency by relating introduction modes to naturalization. With conceptual papers and a first review of human‐mediated plant introductions, Thellung stimulated further research on plant invasions as well as modern terminological frameworks for alien plants.

Main conclusions

Albert Thellung was an outstanding member of the group of pre‐Eltonian invasion scientists. He opened up focussed research in the field of alien plants in Europe, and his theoretical approaches were a powerful step towards unifying concepts in invasion ecology.
Measuring the international spreading of the knowledge produced by French dental master theses
Authors: Gillet D. , Bérard A. , Faivre O. , Sarrazy B.
Published: September 2012

We estimated the international spreading of the knowledge produced by French dental master theses by searching for corresponding publications, either as articles in Medline‐indexed journals or abstracts of IADR meetings published in the Journal of Dental Research. From the 634 theses defended in 2010 in the 16 French odontology faculties, we found only one article, in a journal without impact factor, and six abstracts, over a 3‐year period (2009—2011). This corresponds to a spreading rate of 0.6%. The participation rate of French odontology faculties at IADR meetings varies from 37.5% to 81.3% depending on the year. Although there are very few studies available on the matter, it appears that this international spreading rate is much lower than both the one found by Nieminen for odontology in Finland (8.2%) and typical spreading rates of medical theses (from 6% to 41% depending on the country). This great discrepancy could be explained by the lack of specific training provided to the students; the low awareness and little engagement of the students themselves, usually more concerned with their own private practice work; and the inadequate involvement of their supervisors. To tackle the lack of appropriate training, we suggest that a specific course on scientific writing should be offered to the students in the last year of their dental master studies.
Clinical and preclinical validation of the serum free light chain assay: identification of the critical difference for optimized clinical use
Authors: Hansen Charlotte T. , Münster Anna‐Marie , Nielsen Lars , Pedersen Per , Abildgaard Niels
Published: September 2012

Objectives

The use of the assay for the measurements of free light chains in serum (sFLCs) is increasing. However, there are technical limitations that potentially affect the use in serial measurements. We need further knowledge on the standards of analytical precision, the utility of conventional population‐based reference values and the critical difference (CD) between serial results required for significance. To answer these questions, the biological variation must be known.

Methods

We determined the biological variation in healthy individuals and patients with plasma cell dyscrasia (PCD). We assessed the imprecision of the analysis in use from FreeLite™. We determined the reference interval (RI) in 170 healthy individuals.

Results

The biological variation is identical for healthy individuals and patients with PCD. The imprecision of the sFLC analysis cannot fulfil the desirable performance standards for a laboratory test, but are within the manufacturer's ±20% variation for quality control samples. RI showed a significant increase for κ FLC and κ/λ ratio with age, but not for λ. Critical difference was calculated to be 24% and 23% for κ and λ, respectively.

Conclusions

We suggest the use of an age‐dependent RI. When monitoring patients with PCD, their own former results are the best reference, and knowledge on CD is a valuable tool, which we describe for the first time. Also, it challenges the recently proposed International Myeloma Working Group ‘paraprotein relapse criteria’, recommending an increase of more than 25% in the involved FLC to indicate the need for initiation of retreatment. We recommend revision of this criterion.
Nature versus nurture: does human skin maintain its stratum corneum lipid properties in vitro?
Authors: Thakoersing Varsha S. , Danso Mogbekeloluwa O. , Mulder Aat , Gooris Gerrit , El Ghalbzouri Abdoelwaheb , Bouwstra Joke A.
Published: September 2012

Human skin equivalents (HSEs) mimic human skin closely, but show differences in their stratum corneum (SC) lipid properties. The aim of this study was to determine whether isolation of primary cells, which is needed to generate HSEs, influence the SC lipid properties of HSEs. For this purpose, we expanded explants of intact full thickness human skin and isolated epidermal sheets in vitro. We investigated whether their outgrowths maintain barrier properties of human skin. The results reveal that the outgrowths and human skin have a similar morphology and expression of several differentiation markers, except for an increased expression of keratin 16 and involucrin. The outgrowths show a decreased SC fatty acid content compared with human skin. Additionally, SC lipids of the outgrowths have a predominantly hexagonal packing, whereas human skin has the dense orthorhombic packing. Furthermore, the outgrowths have lipid lamellae with a slightly reduced periodicity compared with human skin. These results demonstrate that the outgrowths do not maintain all properties observed in human skin, indicating that changes in properties of HSEs are not caused by isolation of primary cells, but by culture conditions.
Intercellular pathway through hyaluronic acid inUVB‐induced inflammation
Authors: Hiramoto Keiichi , Kobayashi Hiromi , Yamate Yurika , Ishii Masamitsu , Sato Eisuke F.
Published: September 2012

Ultraviolet B (UVB) radiation induces inflammation in the skin specifically at the site of exposure. We unexpectedly found thatUVB‐induced inflammation was not induced in gp91phox‐depleted mice. To test whether gp91phox is directly involved inUVB‐induced inflammation, neutrophil‐ and hyaluronic acid–depleted mice were also irradiated and examined for their response. Hyaluronic acid–depleted mice showed strongly inhibitedUVB‐induced inflammation, but the neutrophil‐depleted mice did not exhibit any suppressedUVB‐induced inflammation. To elucidate the pathway by whichUVBirradiation induced inflammation, we examined the expression of nucleotide‐binding domain, leucine‐rich‐containing family, pyrin domain‐containing‐3 (NLRP3) and caspase‐1 in the mouse skin. An increase in the expression ofNLRP3 and caspase‐1 was seen following theUVBirradiation of C57BLmice; however, theUVB‐irradiated gp91phox‐knockout (gp91phox−/−) mice did not have this increase in expression. Furthermore, the plasmaIL‐1β level increased after theUVBirradiation in C57BLmice, but there was no change in the gp91phox−/−mice. These results clearly indicate that nicotinamide adenine dinucleotide phosphate oxidase is activated by gp91phox, which is expressed on the surface in response to the increased expression of hyaluronic acid induced byUVBirradiation, and as result, the generation of reactive oxygen species (ROS) increases. ThisROSactivateNLRP3, andNLRP3 leads to the production of caspase‐1, which subsequently increasesIL‐1β, thereby finally inducing inflammation. It is thought that this system may play an important role in the damage and ageing of skin, and further studies are necessary to confirm these finding.
Extracellular histones inhibit hair shaft elongation in cultured human hair follicles and promote regression of hair follicles in mice
Authors: Shin Seung Hyun , Joo Hyun Woo , Kim Moon Kyu , Kim Jung Chul , Sung Young Kwan
Published: September 2012

Release of histone H4 in rat vibrissa dermal papilla (DP) cells exposed to sub‐toxic dose of colchicines has been recently reported. In addition, exposure to histone H4 has been reported to result in inhibited proliferation and reduced alkaline phosphatase (ALP) activity of cultured vibrissa DP cells. These findings prompted us to investigate the role of extracellular histones in hair growth using cultured human hair follicles and hair cycling using back skin of mice. We report here that exposure of cultured hair follicles to histone H4 and H2A resulted in significant inhibition of elongation of hair shafts, decreased expression of IGF‐1 and decreased expression and activity of ALP. Injection of histones into hypodermis of mice during anagen resulted in premature onset of catagen. Findings of the current study provide strong evidence suggesting the inhibitory role of extracellular histones in hair growth.
Climate‐diameter growth relationships of black spruce and jack pine trees in borealOntario,Canada
Authors: Subedi Nirmal , Sharma Mahadev
Published: September 2012

To predict the long‐term effects of climate change – global warming and changes in precipitation – on the diameter (radial) growth of jack pine (Pinus banksianaLamb.) and black spruce (Picea mariana[Mill.] B.S.P.) trees in borealOntario, we modified an existing diameter growth model to include climate variables. Diameter chronologies of 927 jack pine and 1173 black spruce trees, growing in the area from 47°N to 50°N and 80°W to 92°W, were used to develop diameter growth models in a nonlinear mixed‐effects approach. Our results showed that the variables long‐term average of mean growing season temperature, precipitation during wettest quarter, and total precipitation during growing season were significant (alpha = 0.05) in explaining variation in diameter growth of the sample trees. Model results indicated that higher temperatures during the growing season would increase the diameter growth of jack pine trees, but decrease that of black spruce trees. More precipitation during the wettest quarter would favor the diameter growth of both species. On the other hand, a wetter growing season, which may decrease radiation inputs, increase nutrient leaching, and reduce the decomposition rate, would reduce the diameter growth of both species. Moreover, our results indicated that future (2041–2070) diameter growth rate may differ from current (1971–2000) growth rates for both species, with conditions being more favorable for jack pine than black spruce trees. Expected future changes in the growth rate of boreal trees need to be considered in forest management decisions. We recommend that knowledge of climate–growth relationships, as represented by models, be combined with learning from adaptive management to reduce the risks and uncertainties associated with forest management decisions.
Topical application of 1% chlorhexidine gel versus 0.2% mouthwash in the treatment of peri‐implant mucositis. An observational study
Authors: De Siena F , Francetti L , Corbella S , Taschieri S , Del Fabbro M
Published: September 2012

Objective

The aim of this study was to compare the use of two chlorhexidine‐based antimicrobial agents as an adjunct to mechanical therapy for the treatment of peri‐implant mucositis.

Materials and methods

Thirty patients with peri‐implant mucositis were included in the study and randomized in two groups. In addition to mechanical therapy, group A was treated with chlorhexidine 0.2% mouthwash, while group B was treated with chlorhexidine 1% gel. Probing depth, plaque index and bleeding index were recorded at each scheduled follow‐up visit: ten days, 1 month and 3 months after giving the patients the assigned formulation. Patients had to fill in a questionnaire investigating their satisfaction and ease of use of the product.

Results

A total of 23 patients (13 in group A and 10 in group B) attended all the follow‐up visits. Chlorhexidine 0.2% mouthwash and chlorhexidine 1% gel were equally useful in the treatment of peri‐implant mucositis leading to the reduction in inflammatory parameters. Probing depth decreased over time in both groups. Patients showed preference for gel formulation even if they found it more difficult to use.

Conclusions

Adjunctive treatment with different chlorhexidine formulations was beneficial to the treatment of peri‐implant mucositis. Besides, no differences could be found between 0.2% mouthwash and 1% gel.
Nurses’ attitudes towards physical activity care among older people
Authors: Wu Shu Chen , Wu Shiang‐Feng , Huang Hui‐Chi
Published: September 2012

Aims and objectives.  To understand nurses’ attitudes towards physical activity care for older people in long‐term care facilities.

Background.  In long‐term care facilities, a common approach to daily physical activity is based on the identifiable portions of daily life during which the activity occurs. However, older people are at risk of falling when they perform daily physical activities. Nurses are the first‐line caregivers. What nurses’ think and do regarding older people’s participation in daily physical activities in long‐term care facilities is very important in terms of the clinical decision‐making regarding older people’s physical activity care.

Design.  An exploratory qualitative design.

Methods.  Twenty nurses with more than three years of clinical experience from 13 long‐term care facilities located in northern Taiwan were sampled purposively. Data were collected though semi‐structured interviews. The constant comparative data analysis method was used throughout the research.

Results.  Five themes emerged from the data analysis: ‘recognising the importance of participation in daily physical activity’, ‘encouraging participation in physical activity’, ‘respecting the autonomy of the residents regarding participation in physical activity’, ‘preventing falls’ and ‘facing a dilemma’.

Conclusions.  This study identifies that there is a conflict between the nurses’ perceptions of the residents’ daily physical activities, the risk of falls and encouraging greater independence. The majority of staff employed in long‐term care facilities is nursing personnel, and it is these nurses who have the most contact with the residents. It is therefore believed that nurses can make the greatest difference to the residents’ lives and support the quality of care if they can resolve this conflict.

Relevance to clinical practice.  The results suggest the need to increase the nurses’ knowledge base regarding the benefits of physical activity and also highlight the potentially adverse effect of restraint usage by nurses.
Reported medication errors after introducing an electronic medication management system
Authors: Redley Bernice , Botti Mari
Published: September 2012

Aims and objectives

To explore the effects of introducing an electronic medication management system on reported medication errors.

Background

Computerised medication management systems have been found to improve medication safety; however, introducing medication management system into healthcare environments can create unanticipated or new problems and opportunities for medication error.

Design

Descriptive analysis of medication error reports.

Methods

This was a retrospective analysis of 359 incident reports drawn from the period of 1 May 2005–30 April 2006 across two hospital sites of a single not‐for‐profit private health service located in metropolitan Melbourne. Site A used a conventional pen and paper system for medication management, and Site B had introduced a computerised medication management system.

Results

Most medication errors occurred at the nurse administration (71·5%) and prescribing (16·4%) stages of delivery. The most common medication error type reported at Site A was omission (33%), and at Site B was wrong documentation (24·2%). A higher proportion of errors at the prescribing phase, and less nurse administration errors, were detected at Site B where the medication management system was in use. The incidence of other, less frequent errors was similar across the two hospital sites.

Conclusions

This examination of medication error reports suggests there are differences in the types of medication errors that are reported in association with the introduction of electronic medication management system compared to pen and paper system systems. The findings provide a new insight into the effects of introducing an electronic medication management system on the types of medication errors reported.

Relevance to clinical practice

The findings provide a new insight into the types of medication errors that are reported during implementation of an electronic medication management system. Extra support for physicians prescribing practices should be considered.