bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological Flora of the British Isles:Silene suecica
Authors: Nagy Laszlo
Published: May 2013

This account presents information on all aspects of the biology ofSilene suecica(Lodd.) Greuter & Burdet (Lychnis alpinaL.) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of theBiologicalFlora of theBritishIsles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history and conservation.

Silene suecicais native to the British flora, being found in just two confirmed localities (one in north‐westEngland and the other inScotland) on open fell‐field and rocky outcrop habitats. It occurs on acid to neutral soil inBritain and elsewhere its circum‐arctic range. It often indicates elevated concentrations of copper or other heavy metals, whose presence in the soil restricts the growth of other species; therefore,S. suecicais perceived as a stress‐tolerant, competition‐avoiding species. Nonetheless, it also grows in more or less closed alpine grassland inEurope; inNorthAmerica andGreenland, it is known from tundra, rocky barrens, gulleys and river outwashes, grassy slopes and sea cliffs.

Silene suecicais a (semi‐)rosette plant with a strong taproot, with no capacity for vegetative spread. The main perennating organ is the slightly lignified rootstock/taproot. The rosette has winter‐green leaves; after flowering the rosette leaves die, but new lateral rosettes may be produced in the following year. The longevity of the species is between 3 and 10 years, with the time of first flowering depending on rosette size. Plants that have flowered may die (semelparous individuals), but some are iteroparous and flower again on lateral shoots.

Silene suecicaproduces protandrous hermaphrodite flowers, but self‐pollination may occur. InScotland about 10% of all plants flower in any year. Pollination is by a range of insects, including flies and bees. Capsules produce up to 80 seeds (mean = 30).

Silene suecicahas probably not declined in theBritishIsles and, in fact, a slight population expansion in permanent plots was observed inScotland in the early 1990s. Nonetheless, it remains classed as vulnerable to extinction because of its restricted distribution. Both of itsBritish locations are protected asSSSIandSAC(Natura 2000) within national parks. It is common in many countries within its distribution range.
Variability in functional traits mediates plant interactions along stress gradients
Authors: Schöb Christian , Armas Cristina , Guler Manuela , Prieto Iván , Pugnaire Francisco I.
Published: May 2013

Environmental gradients may influence a plant's physiological status and morphology, which in turn may affect plant–plant interactions. However, little is known about the relationship between environmental variation, physiological and morphological variability of plants and variation in the balance between competition and facilitation.

Mountain ranges in dry environments have opposing altitudinal environmental gradients of temperature and aridity, which limit plant growth at high and low elevations. This makes them particularly suitable for exploring the relationships between environmental conditions, plant phenotype and plant–plant interactions. We hypothesized that different environmental stressors will differently affect the physiological status of a nurse plant. This, then, manifests itself as variation in nurse plant morphological traits, which in turn mediates plant–plant interactions by altering microhabitat conditions for the nurse and associated species.

In an observational study, we measured a series of functional traits of Arenaria tetraquetra cushions as indicators of its physiological status (e.g. specific leaf area, relative water content) and morphology (e.g. cushion compactness, size). Measurements were taken along the entire elevation range where A. tetraquetra occurs. Furthermore, we analysed how these functional traits related to soil properties beneath cushions and the number of associated species and individuals compared with open areas.

Cushions at high elevation showed good physiological status; they were compact and large, had higher soil water and organic matter content compared with open areas and showed the strongest facilitation effect of the whole elevation gradient – that is, the highest increase in species richness and abundance of beneficiaries compared with open areas. Physiological data at low elevation indicated stressful abiotic conditions for A. tetraquetra, which formed loose and small cushions. These cushions showed less improved soil conditions and had reduced facilitative effects compared with those at high elevation.

Synthesis. Functional traits of the nurse species varied distinctively along the two opposing stress gradients, in parallel to the magnitude of differences in microenvironmental conditions between cushions and the surrounding open area, and also to the facilitation effect of cushions. Our data, therefore, provides a strong demonstration of the generally overlooked importance of a nurse plant's vigour and morphology for its facilitative effects.
Subordinate plant species enhance community resistance against drought in semi‐natural grasslands
Authors: Mariotte Pierre , Vandenberghe Charlotte , Kardol Paul , Hagedorn Frank , Buttler Alexandre
Published: May 2013

According to the insurance hypothesis, more diverse plant communities are more likely to be resistant to drought. Whilst many experiments have been carried out to determine the effects of plant diversity on plant community insurance, the results are still contradictory.

Here, we conducted a drought experiment where we tested whether the presence of subordinate species increases plant community insurance. In Swiss Jura grassland, we combined a removal experiment of subordinate species with a summer drought event using rainout shelters.

Plant community composition was determined after the drought and based on biomass measurements; we estimated resistance, recovery and resilience of the plant community for each combination of treatments. Moreover, to assess drought impacts on water‐use efficiency (WUE), we analysed carbon isotope ratios (δ13C values) in plant leaves of two dominants and two subordinates collected at the end of the drought period.

We showed that subordinate species are more resistant to drought and increased community resistance by enhancing their above‐ground biomass production during the imposed drought. These patterns were associated with decreased competitiveness of dominant species whose biomass decreased during drought. Significant increase in δ13C values in plant tissue under drought indicated a better WUE for the measured species. Interestingly, the WUE was significantly higher in plots where subordinates were removed. Recovery and resilience were not affected by the summer drought, but the absence of subordinates reduced overall above‐ground biomass in both watered and drought plots.

Synthesis. We demonstrated that, independent of plant diversity, the presence of drought‐resistant subordinate species increases plant community insurance against drought and, hence, is important for the functioning of grassland ecosystems.
Convergent specialization – the sharing of pollinators by sympatric genera of sexually deceptive orchids
Authors: Phillips Ryan D. , Xu Tingbao , Hutchinson Michael F. , Dixon Kingsley W. , Peakall Rod
Published: May 2013

Pollinator sharing can offer powerful insights into the floral traits associated with the evolution of a pollination system and the consequences of floral differences for pollinator behaviour. Here, we investigate the first known case of pollinator sharing between two sexually deceptive plant genera. Floral manipulations were used to test the importance of floral traits for pollinator behaviour and pollination efficiency. We also explored the ecological differences enabling species co‐occurrence.

Drakaea livida and Caladenia pectinata (Orchidaceae) exhibit dramatic differences in floral display and the insectiform appearance of the labellum, yet both are pollinated by sexually attracted males of the thynnine wasp Zaspilothynnis nigripes. Because of the prevalence of cryptic species in some genera of thynnine wasps, we confirmed pollinator sharing by a mark–recapture study and sequencing of the mtDNA CO1 region.

Floral dissections revealed that semiochemicals used to attract the pollinator are released from the labellum in D. livida and sepaline clubs in C. pectinata. Drakaea livida was more efficient at converting pollinator attraction into potential pollen deposition leading to higher fruit set. Floral manipulations showed that pollinator contact with the labellum increases when it is the point of semiochemical release. However, sexual attraction to the labellum remained infrequent in C. pectinata in all experimental treatments.

While their distribution and climatic range show extensive overlap, the differences in edaphic requirements of the two orchid species suggest that they rarely co‐occur. Therefore, the potential cost of sharing the same pollinator species is not realized.

Synthesis. This case of pollinator sharing confirms that morphological traits do not place a strong constraint on the evolution of sexual deception. However, interspecific differences in floral traits have important consequences for converting attraction into pollination, suggesting that selection can act to increase efficiency at multiple steps of the pollination process. This system provides a novel opportunity to elucidate the chemical, visual and morphological adaptations underpinning the evolution of sexual mimicry.
Evidence for transient dynamics in plant populations based on long‐term demographic data
Authors: Ellis Martha M.
Published: May 2013

Recent interest in the importance of short‐term, transient responses in population dynamics has prompted the development of many new methods for describing transient responses in population models. Many of these methods focus on the largest possible responses for a model, thus providing a description of the ‘transient potential’ of a model that does not depend on knowledge of initial conditions in the population.

This study uses long‐term demographic data from five perennial plant species to evaluate how well measures of transient potential reflect actual transient responses in the populations. I used previously published matrix population models to create a set of initial conditions derived from empirically‐based simulations for each population. Maximum transient responses within this set of initial conditions were then compared with responses used in describing transient potential.

Transient responses based on empirical modeling results were smaller than responses used for measures of transient potential.

Realized responses were strongly correlated with the distance between the current demographic structure in the population and the asymptotically stable stage structure of the model (SSD).

Theoretical transient potential was predictive of the amount of variation in distance from SSD observed in each population in the simulations.

Synthesis. Methods based on largest possible responses tend to overemphasize the role of transient dynamics. These results suggest that traditional, asymptotic analyses may be appropriate in many cases. Measures of transient potential can be helpful for identifying species and situations that may be prone to larger transient responses, but do not necessarily indicate that transient dynamics are more important in those systems.
Preferences or plasticity in nitrogen acquisition by understorey palms in a tropical montane forest
Authors: Andersen Kelly M. , Turner Benjamin L.
Published: May 2013

Soil nitrogen (N) occurs in a range of chemical forms from simple inorganic compounds, such as nitrate () and ammonium (), to organic compounds, such as amino acids. Plants differ in their capacity to use these various forms, which might influence the distribution of species across environmental nutrient gradients.

We tested the hypothesis that the distribution of understorey palm species along a soil N gradient in a tropical montane forest in Panama is related to preferences for different chemical forms of N. We conducted a field experiment using 15N‐labelled ammonium, nitrate and glycine to examine whether tropical plants show preferences for, or are flexible in, their use of chemical forms of soil N.

All species used N from inorganic and organic sources and showed no preference for chemical forms of N. However, across all species, the overall N acquisition pattern was glycine ≥ nitrate ≥ ammonium. Species from low‐nutrient sites dominated by ammonium and organic N forms had inherently slow N uptake rates.

Synthesis. Patterns in the distribution of understorey palms were related to nitrogen (N) uptake rates rather than preferences for N chemical forms. Down‐regulation of N uptake rates may be an important adaptation for plant species associated with low‐N soils, with plasticity in N acquisition patterns from various N sources important in alleviating competition for soil N.
Competitive interactions across a soil fertility gradient in a multispecies forest
Authors: Coates K. David , Lilles Erica B. , Astrup Rasmus
Published: May 2013

Whether plant competition grows stronger or weaker across a soil fertility gradient is an area of great debate in plant ecology. We examined the effects of competition and soil fertility and their interaction on growth rates of the four dominant tree species in the sub‐boreal spruce forest of British Columbia.

We tested separate soil nutrient and moisture indices and found much stronger support for models that included the nutrient index as a measure of soil fertility.

Competition, soil fertility and their interaction affected radial growth rates for all species.

Each species supported a different alternate hypothesis for how competitive interactions changed with soil fertility and whether competition intensity was stronger or weaker overall as soil fertility increased depended on the context, specifically, species, neighbourhood composition and type of competition (shading vs. crowding).

The four species varied slightly in their growth response to soil fertility.

Individual species had some large variations in the shapes of their negative relationships between shading, crowding and tree growth, with one species experiencing no net negative effects of crowding at low soil fertility.

Goodness‐of‐fit was not substantially increased by models including competition–soil fertility interactions for any species. Tree size, soil fertility, shading and crowding predicted most of the variation in tree growth rates in the sub‐boreal spruce forest.

Synthesis. The intensity of competition among trees across a fertility gradient was species‐ and context‐specific and more complicated than that predicted by any one of the dominant existing theories in plant ecology.
Genetically based vertical transmission drives the frequency of the symbiosis between grasses and systemic fungal endophytes
Authors: Gibert Anaïs , Hazard Laurent
Published: May 2013

Understanding the variation in hereditary symbiont frequency among host populations is a prerequisite to predict symbiont fixation processes. However, the mechanisms driving this variation remain elusive. Exploring the mechanisms responsible for the observed variability on an ecological time scale requires simultaneous study of fitness differentials between symbiotic (S) and non‐symbiotic (NS) hosts, and the symbiont transmission rates to host offspring.

We studied these two key mechanisms using a grass–endophyte symbiosis in the alpine grass Festuca eskia. Plants from four native populations varying in endophyte frequencies (ranging from 13% to 100%), and environmental conditions (water availability, and grazing pressure) were transplanted in a common garden. Soil nutrient levels were manipulated to assess genetic and environmental differences within and among populations in fitness‐related traits (i.e. traits linked to clonal growth, sexual reproduction and resource acquisition).

A fitness differential favouring S over NS plants was detected in all studied populations: in heavily grazed populations, sexual reproduction was higher in S compared with NS plants, whereas in minimally grazed populations, clonal growth increased. Results showed a positive correlation between endophyte transmission rates and population endophyte symbiotic frequencies. The population endophyte transmission rates were not affected by soil resource level.

According to selection pressures acting in each population, symbiotic plants appear to perform better in all F. eskia populations. The correlation between endophyte frequencies and transmission, and the positive effect of S on NS plants under our experimental conditions, indicated a predominant role of endophyte transmission in endophyte frequency variation in F. eskia. The endophyte transmission rate variation is genetically based at the population level and can be explained by a trade‐off with a specific host trait subjected to strong selection; here, we suspected traits linked to plant resource acquisition.

Synthesis: Our study provides evidence for the (i) dominant role of endophyte transmission and its responsibility for endophyte frequency variation in a native grass when compared with fitness differential process between S and NS plants at an ecological time scale, and (ii) genetically based variation in endophyte transmission rates. We also confirm the population specificity of positive endophyte effects in a native grass.
Pathogen accumulation and long‐term dynamics of plant invasions
Authors: Flory S. Luke , Clay Keith
Published: May 2013

The diversity of pathogens on highly abundant introduced hosts has been positively correlated with time since introduction, geographical range of the introduced species and diversity of invaded habitats. However, little is known about the ecological effects of pathogen accumulation on non‐native invasive plants.

Pathogen accumulation on invasive plant species may result from ecological processes such as high plant densities, expanding geographical ranges and pathogen dispersal from the native range, or evolutionary mechanisms such as host range shifts and adaptation of native pathogens to invasive species.

Over time pathogen accumulation may cause decline in the density and distribution of invasive plants and facilitate recovery of native species. Alternatively, pathogens might build up on invasive species and then spill back onto co‐occurring native species, further exacerbating the effects of invasions.

Synthesis. Research efforts should focus on determining the long‐term outcomes of pathogen accumulation on invasive species. Such research will require multifaceted approaches including comparative studies of diverse invasive species and habitats, experimental manipulations of hosts and pathogens in nature and controlled environments, and predictive models of host‐pathogen interactions within an invasion framework. Results of this research will improve our understanding and ability to predict the outcomes of biological invasions.
Caribou exclusion during a population low increases deciduous and evergreen shrub species biomass and nitrogen pools in low Arctic tundra
Authors: Zamin Tara J. , Grogan Paul
Published: May 2013

Increased shrub growth has been observed across the Arctic with recent climate warming trends, whilst many populations of caribou and reindeer (Rangifer) have been in decline. Paradoxically, our current understanding of the impacts of caribou and reindeer in altering trajectories of Arctic vegetation change is almost entirely dependent on studies with relatively high density semi‐domesticated herds in Fennoscandia. With many wild herd populations across the Arctic presently at much lower densities, it is important to understand the impact of low intensity browsing on shrub biomass and the soil nutrient pools that fuel it.

We used exclosures that have been in place for 5 years in mesic birch hummock tundra in the central Canadian low Arctic to investigate the impact of caribou exclusion on tundra shrub biomass, tissue chemistry and plant and soil nitrogen (N) pools. Over the study period, the migratory tundra caribou herd in the region declined from 25% to 7% of its previous population maximum.

Caribou exclusion significantly enhanced the above‐ground biomass components of one deciduous shrub (Betula glandulosa) and two evergreen shrubs (Vaccinium vitis‐idaea and Rhododendron subarcticum). In particular, exclusion doubled B. glandulosa leaf biomass and increased V. vitis‐idaea old leaf biomass 1.7 times, with the strongest effects in evergreens present in tissues > 1 year old, indicating a legacy of browsing from the earlier years of the experiment when the caribou population was higher. Meanwhile, Vaccinium uliginosum biomass and overall vascular plant diversity tended to decline with exclusion. Caribou exclusion increased B. glandulosa leaf N pools by 0.15 g N m−2 (equivalent to 12% of the total vascular plant community annual N requirement for apical growth). Altogether exclusion did not alter total above‐ground N pools, but rather led to a redistribution of shoot biomass and N, enhancing spatial variability in a key growth‐limiting resource for tundra plants.

Synthesis. Excluding caribou during a population low resulted in ecologically significant changes in the distribution of plant above‐ground biomass and nitrogen, further increasing the dominance of the three most abundant shrubs. These findings demonstrate that, despite uncertainty in herd recovery, Rangifer browsing impacts to both deciduous and evergreen shrub species should be considered for more robust projections of Arctic vegetation change.
The pace and shape of senescence in angiosperms
Authors: Baudisch Annette , Salguero‐Gómez Roberto , Jones Owen R. , Wrycza Tomasz , Mbeau‐Ache Cyril , Franco Miguel , Colchero Fernando
Published: May 2013

Demographic senescence, the decay in fertility and increase in the risk of mortality with age, is one of the most striking phenomena in ecology and evolution. Comparative studies of senescence patterns of plants are scarce, and consequently, little is known about senescence and its determinants in the plant kingdom.

Senescence patterns of mortality can be classified by distinguishing between two metrics: pace and shape. The pace of mortality captures the speed at which life proceeds and can be measured by life expectancy, while the shape of mortality captures whether mortality increases (‘senescence’), decreases (‘negative senescence’) or remains constant over age (‘negligible senescence’).

We extract mortality trajectories from ComPADRe III, a data base that contains demographic information for several hundred plant species. We apply age‐from‐stage matrix decomposition methods to obtain age‐specific trajectories from 290 angiosperm species of various growth forms distributed globally. From these trajectories, we survey pace and shape values and investigate how growth form and ecoregion influence these two aspects of mortality using a Bayesian regression analysis that accounts for phylogenetic relationships using a resolved supertree.

In contrast to the animal kingdom, most angiosperms (93%) show no senescence. Senescence is observed among phanerophytes (i.e. trees), but not among any other growth form (e.g. epiphytes, chamaephytes or cryptopyhtes). Yet, most phanerophytes (81%) do not senesce. We find that growth form relates to differences in pace, that is, life span, as woody plants are typically longer lived than nonwoody plants, while differences in shape, that is, whether or not angiosperms senesce, are related to ancestral history.

Synthesis: The age trajectory of mortality captures a fundamental life‐history pattern for a species that is crucial to ecological understanding. We contribute to ecological knowledge by surveying these patterns across angiosperms. The novelty and strength of our study lies in the comprehensiveness of the data set, the use of a novel Bayesian analysis that accounts for phylogenetic history and in the distinction between metrics of pace and shape as two separate aspects of mortality. We believe that our approach could prove useful in future comparative studies of mortality patterns.
Plants do not count… or do they? New perspectives on the universality of senescence
Authors: Salguero‐Gómez Roberto , Shefferson Richard P. , Hutchings Michael J.
Published: May 2013

Senescence, the physiological decline that results in decreasing survival and/or reproduction with age, remains one of the most perplexing topics in biology. Most theories explaining the evolution of senescence (i.e. antagonistic pleiotropy, accumulation of mutations, disposable soma) were developed decades ago. Even though these theories have implicitly focused on unitary animals, they have also been used as the foundation from which the universality of senescence across the tree of life is assumed.

Surprisingly, little is known about the general patterns, causes and consequences of whole‐individual senescence in the plant kingdom. There are important differences between plants and most animals, including modular architecture, the absence of early determination of cell lines between the soma and gametes, and cellular division that does not always shorten telomere length. These characteristics violate the basic assumptions of the classical theories of senescence and therefore call the generality of senescence theories into question.

This Special Feature contributes to the field of whole‐individual plant senescence with five research articles addressing topics ranging from physiology to demographic modelling and comparative analyses. These articles critically examine the basic assumptions of senescence theories such as age‐specific gene action, the evolution of senescence regardless of the organism's architecture and environmental filtering, and the role of abiotic agents on mortality trajectories.

Synthesis. Understanding the conditions under which senescence has evolved is of general importance across biology, ecology, evolution, conservation biology, medicine, gerontology, law and social sciences. The question ‘why is senescence universal or why is it not?’naturally calls for an evolutionary perspective. Senescence is a puzzling phenomenon, and new insights will be gained by uniting methods, theories and observations from formal demography, animal demography and plant population ecology. Plants are more amenable than animals to experiments investigating senescence, and there is a wealth of published plant demographic data that enable interpretation of experimental results in the context of their full life cycles. It is time to make plants count in the field of senescence.
Serial changes in adipocytokines and cardiac function in a rat model of the metabolic syndrome
Authors: Yamaguchi Takanori , Kitamori Kazuya , Ichihara Gaku , Suzuki Yuka , Ochiai Miyuki , Yamada Yoshiji , Tada‐Oikawa Saeko , Tsuchikura Satoru , Yamori Yukio , Ichihara Sahoko
Published: May 2013

Obesity is associated with high chronic cardiac workload due to the need to supply more blood to peripheral tissue, and frequently leads to left ventricular (LV) dysfunction. The present study examined serial changes in cardiac function in the SHR/NDmcr‐cp (SHR/cp) strain, an experimental model of obesity plus hypertension and metabolic syndrome.

Transthoracic echocardiography was used to define cardiac dimensions and function in male spontaneously hypertensive rats (SHR/lean), SHR/cp and Wistar‐Kyoto rats. We also assessed age‐related changes in plasma and LV adipocytokine levels in this model.

Although there were no significant differences in LV end‐diastolic diameter and end‐systolic diameter among the three rat strains until 24 weeks of age, these parameters were significantly higher and LV fractional shortening (%FS) was significantly lower in SHR/cp compared with SHR/lean at 32 weeks of age. At the same age, pronounced interstitial fibrosis and infiltration of macrophages and T lymphocytes into the LV was noted in SHR/cp relative to the other strains. In the myocardium, adiponectin levels were significantly lower and resistin levels and the expression of proinflammatory cytokines (tumour necrosis factor‐α and interleukin‐6) were significantly higher in SHR/cp than SHR/lean at 32 weeks of age.

Using echocardiography, we demonstrated reduced systolic function in 32‐week‐old SHR/cp. Changes in myocardial cytokine concentrations could be involved in worsening of cardiac function in our animal model of metabolic syndrome.
Technology Sourcing and Reverse Productivity Spillovers in the Multinational Enterprise: Global or Regional Phenomenon?
Authors: Driffield Nigel , Love James H. , Yang Yong
Published: May 2013

The focus of this paper is the importance of regions in technology transfer by the multinational firm. Specifically, we focus on an issue that has become known as knowledge or technology sourcing via ‘reverse spillovers’, i.e. productivity effects running from domestic firms to foreign establishments. Traditionally this issue has presented a challenge for international business scholars, both in terms of identifying the phenomenon and in terms of determining the success of the strategy. In this paper we examine these questions within the context of the debate on globalization/regionalization. For a set of some 4500 subsidiaries of multinationals across a wide range of countries we show that reverse productivity spillovers via technology sourcing are significant but that they tend to be concentrated within ‘triad regions’ rather than across them. We also find that reverse spillovers from host country multinational enterprises are greater than those from other host country firms or from other foreign affiliates.
Testing the Regional Performance of Multinational Enterprises in the Retail Sector: The Moderating Effects of Timing, Speed and Experience
Authors: Mohr Alex , Fastoso Fernando , Wang Chengang , Shirodkar Vikrant
Published: May 2013

Drawing on regional strategy theory we complement the core effect of firm‐specific advantages on the performance of multinational enterprises with an analysis of the performance consequences of home region concentration on firm performance. We also develop hypotheses regarding the effect of foreign entry timing, internationalization speed and international experience on the performance effect of home region concentration. We test our hypotheses against unique longitudinal data from a panel of 128 multinational enterprises in the retail sector whose geographical spread of international activities we traced between 1995 and 2010. Our findings support the predictions of regional strategy theory and highlight the importance of foreign entry timing and internationalization speed in strengthening the positive effect of home region concentration on the performance of multinational enterprises.
A Regional Perspective on Multinational Expansion Strategies: Reconsidering the Three‐stage Paradigm
Authors: Oh Chang Hoon , Contractor Farok
Published: May 2013

Empirical studies on international expansion have shown only limited support for the three‐stage (S‐curve) hypothesis. Whilst the basic concept is intuitively acceptable, the very generality of the paradigm is its weakness in empirical studies. This paper takes a more fine‐grained theoretical and empirical approach by distinguishing between the regions covered by different multinational companies. The regional scope covered by a multinational firm makes a substantial difference with regard to its performance. We find that most firms can enhance their performance by focusing on their home region, whilst only a subset of firms operating in both the home and foreign regions show the overall S‐curve relationship between multinationality and performance. Certain combinations of product diversification and regional coverage also enhance performance.
The efficacy, safety and cost‐effectiveness of hydrotalcite versus esomeprazole in on‐demand therapy of NERD: A multicenter, randomized, open‐label study in China
Authors: Xiao Ying Lian , Nie Yu Qiang , Hou Xiao Hua , Xie Peng Yan , Fang Jing Yuan , Yuan Yao Zong , Zhou Li Ya , Zhao Nai Qing , Chen Min Hu
Published: May 2013

Objective

The aim of the study was to investigate whether hydrotalcite was comparable to esomeprazole, a proton pump inhibitor, in on‐demand therapy for non‐erosive reflux disease (NERD).

Methods

This was a multicenter, randomized, open‐label clinical trial with initial and on‐demand therapy. Patients who had complete symptom relief in the initial therapy were randomized to either hydrotalcite or esomeprazole in the on‐demand therapy. The percentage of patients who quit on‐demand therapy in the two groups and the cost‐effectiveness of the treatment were evaluated as primary end points. The rate of symptom relief and the improvement of symptom score for initial therapy and the weekly average symptom score and weekly average number of days on treatment for on‐demand therapy were evaluated as secondary end points.

Results

In total, 398 patients were recruited in the initial therapy group, among whom 253 were included in on‐demand therapy, with 127 patients in the hydrotalcite group and the remaining 126 in the esomeprazole group. 14 (11.0%) patients in the hydrotalcite group and six (4.8%) in the esomeprazole group quit the on‐demand therapy due to unsatisfactory symptom control (P = 0.065). Cost‐effectiveness calculated as the ratio of the cost of hydrotalcite to that of esomeprazole (per person/day) was 35.3% in the on‐demand therapy. Similar number of patients achieved symptom relief in both groups.

Conclusion

Hydrotalcite is a good option of on‐demand therapy for NERD patients due to its cost‐effectiveness and speed of action.
Mastoid pneumocoele with skull base and cervical spine pneumatisation
Authors: Cowan Ian A , Greig Sam R , Bird Philip A
Published: May 2013

Very uncommonly, Eustachian tube dysfunction can lead to symptomatic chronic elevation of middle ear pressure with aeration of bone and adjacent structures in the skull base and upper cervical spine, and an increased risk of fracture. We present a case demonstrating the natural history of this condition over 11 years before treatment and 10 months after treatment.
Patterns of retreatment with radiotherapy in a large academic centre
Authors: Khor Richard , Bressel Mathias , Tai Keen Hun , Ball David , Duchesne Gillian , Rose William , Tedesco Jo , Gill Suki , Fitzpatrick Claire , Foroudi Farshad
Published: May 2013

Aims

To characterise retreatment rates with radiotherapy at a large multifacility academic radiotherapy centre and assess the effect of distance on retreatment rate.

Materials and Methods

Electronic administrative records were reviewed for patients receiving radiotherapy between 1998 and 2010 at regional and metropolitan facilities. Course‐level data were reconstructed from electronic administrative databases. Intent of therapy, treatment dates and diagnosis were available for analysis. Retreatment characteristics were derived, including proportion of patients receiving retreatment, proportion of total radiotherapy prescriptions dedicated to retreatment and retreatment per treating facility. Travel distance for each patient to their treatment centre was estimated, and retreatment rates were reported as a function of increasing distance.

Results

A total of 48 200 patients were treated with 66 277 treatment courses during the study period. Retreatment courses constituted 25.2% of all courses prescribed. During the study period, 20.4% of all patients received at least one treatment course. Of these, the average number of retreatment courses prescribed was 1.84. Patients treated with radical intent had a retreatment rate of 13% compared with 45% for those treated initially with palliative intent. Retreatment rates in individual tumour sites ranged from 1.3 to 44.4%. The retreatment rate for those living less than 100 km from treatment facility was 24.8%, and 20.5% for those living more than 100 km from treatment centre (P < 0.001)

Conclusion

Retreatment accounted for over one quarter of radiotherapy courses, with the rate influenced by casemix and follow‐up duration. With increasing distance from treatment centre, a decrease in retreatment rate was observed.
Significant association between SNPs in the superoxide dismutase 3, extracellular (SOD3) gene and resistance to Aeromonas hydrophila in the freshwater mussel Hyriopsis cumingii
Authors: Wang G. L. , Li X. L. , Li J. L.
Published: May 2013

Extracellular superoxide dismutase (SOD3) is a major antioxidant enzyme that protects organs from damage by reactive oxygen species (ROS). In this study, the SOD3 gene was identified and characterized from the freshwater mussel Hyriopsis cumingii (Hc‐SOD3). The cDNA sequence consists of 763 bp, encoding a protein of 208 amino acids. The amino acid sequence possesses two CuZnSOD signature sequences, and amino acids required for binding of Cu (His‐93, ‐95, ‐110 and ‐169) and Zn (His‐110, ‐118, ‐129 and Asp‐132) were conserved in Hc‐SOD3. The Hc‐SOD3 genomic sequence was 9165 bp in length, containing four exons and three introns. Eighteen single nucleotide polymorphisms were detected in the Hc‐SOD3 gene from resistant stock (RS) and susceptible stock (SS) of H. cumingii to Aeromonas hydrophila. The genotype and allele distribution were examined in resistant and susceptible stocks. Among them, a C/G substitution at the g.7994C>G locus and G/C substitution at the g.8087G>C locus were significantly associated with resistance/susceptibility of H. cumingii to A. hydrophila, both in genotype (P = 0.017, P = 0.004 respectively) and allele frequency (P = 0.021, P = 0.006 respectively). Linkage disequilibrium analysis revealed that g.7994C>G, g.8001A>G, g.8035G>A, g.8087G>C and g.8191T>A were in linkage disequilibrium. The results suggest that the two polymorphic loci, g.7994C>G and g.8087G>C, could be potential genetic markers for future molecular selection of strains that are resistant to diseases.
The local‐food movement and the anthropology of global systems
Authors: Nonini Donald M.
Published: May 2013

Today's wrenching worldwide social and cultural instability calls for more adequate theorization. Through an examination of the local‐food movement in the United States, I consider one such theorization, Kajsa Ekholm Friedman and Jonathan Friedman's anthropology of global systems. The Friedmans set out an original conceptualization of transformations in the political economy of commercial civilizations and processes of identity formation in periods of hegemonic decline. I present data on the local‐food movement in North Carolina and on differences in identity orientations between “sustainable‐agriculture” and “food‐security” activists to evaluate this conceptualization.
Simply the best: Parody and political sincerity in Iceland
Authors: Boyer Dominic
Published: May 2013

Pursuing a self‐described anarcho‐surrealist politics in the aftermath of Iceland's banking crisis, Jón Gnarr shocked the country's political establishment by winning the mayoral election in Reykjavík in May 2010. In this article, I explore the rise of Gnarr's Best Party, especially its refusal to accept a distinction between parody and sincerity in its mode of political performance. Against the backdrop of the increasing monopolization of (neo)liberal political discourse and action, I discuss how “Gnarrism” reflects at once something old and something new in northern liberal democracy.
Bureaucratic aesthetics: Report writing in the Nigérien gendarmerie
Authors: Göpfert Mirco
Published: May 2013

Nigérien gendarmes invest considerable creative energy in their daily paperwork. I explore how the gendarmes conceive of the writing of seemingly purely bureaucratic documents, procès‐verbaux, in aesthetic terms. At the same time, I ground the aesthetic appreciation of these documents in the gendarmes’ socioprofessional environment. Writing an aesthetically satisfying procès‐verbal is a means of gaining respect from colleagues and superiors and of justifying and actualizing gendarmes’ self‐perception as intellectuals in uniform. Bureaucratic work, I argue, is always also aesthetic work, and bureaucratic aesthetics is where aesthetic, pragmatic, and legal reasonings become one.
Feminine power or feminine weakness? North Indian girls’ struggles with aspirations, agency, and psychosomatic illness
Authors: Marrow Jocelyn
Published: May 2013

In Hindi‐speaking northeastern India, mothers whose daughters are afflicted with a psychosomatic illness referred to locally as “the teeth have clenched” employ standard tropes pertaining to Indian femininity to negotiate their daughters’ agency against the backdrop of new aspirations. An inquiry into two cases I encountered during fieldwork in Varanasi psychiatric clinics in 2001–04 demonstrates how girls’ symptomatic bodies mediated social concerns pertaining to the challenges that women's education and work in public spaces present to non‐elite middle‐class domestic orders. While these illnesses may have been born of previous traumas or household conflicts, and sometimes were acknowledged as such, mothers’ and daughters’ own concerns about the illnesses focused on what they indicated about the daughters’ potential for social and academic success. In particular, mothers regarded their daughters as possessing either too much or too little “power” or “strength,” and these attributions attached to their anxieties and hopes for their daughters’ futures. In the drama of clenched teeth, disordered bodies, disruptive behavior, and possible futures were folded into the same metaphors of agency.
Transnational circulation and digital fatigue in Ghana's Azonto dance craze
Authors: Shipley Jesse Weaver
Published: May 2013

Azonto is a Ghanaian urban dance craze whose popularity is built through its global circulation. I trace its production and flow across studios, radio stations, dance floors, and digital platforms in Accra and among Ghanaians in London and New York. I argue that, as a technologically mediated style, Azonto is the embodiment of being Ghanaian in a mobile, digital world. This dance reveals both the potentials and the hazards of digital repetition and copying for self‐recognition. Ghanaian musicians and fans creatively use the repetitive aspects of digital technologies, making this dance a style of symbolic appropriation that links Ghanaian youth both in Accra and abroad into a dispersed community of musical participation that valorizes mobility itself. The dance's sudden ubiquity, however, creates “digital fatigue,” an uncertainty among participants about belonging in an era of digital replication that threatens to unmoor signs of recognition from the cultural registers that empower them in the first place.
State of play: The political ontology of sport in Amazonian Peru
Authors: Walker Harry
Published: May 2013

Building on the importance of “play” in traditional sociality, organized team sports such as soccer are instrumental in promoting a new moral and political order among Urarina people of Peruvian Amazonia, one grounded in notions of roles, rules, and the abstract individual. As a vehicle of nationalist sentiment, highly amenable to ritualization and bureaucratization, sport is central to the process by which the state expands its territory and influence. Like warfare, but unifying rather than fragmenting in its effects, sport harnesses the energy and vitality of youth and co‐opts them for other ends.
Intrahepatic cholestasis of pregnancy is common among patients' first‐degree relatives
Authors: Turunen Kaisa , Helander Kristiina , Mattila Kari J. , Sumanen Markku
Published: May 2013

Intrahepatic cholestasis of pregnancy has been shown to have a genetic predisposition. We studied whether Finnish women who had suffered from the disorder reported their first‐degree relatives to have had liver dysfunction during their pregnancies. Questionnaires were sent in autumn 2010 to a total of 544 former intrahepatic cholestasis of pregnancy patients and 1235 controls, all having delivered during 1969–1988. The response rate was 66.2%. The incidence of intrahepatic cholestasis is 0.5–1.5% of pregnancies in Finland. In our survey, altogether 12.8% of mothers (odds ratio 9.2), 15.9% of sisters (odds ratio 5.3) and 10.3% of daughters (odds ratio 4.8) of women who had suffered from intrahepatic cholestasis of pregnancy had had liver dysfunction during pregnancy. Our findings strengthen the earlier knowledge of the genetic component in intrahepatic cholestasis of pregnancy. We suggest that all pregnant women are asked about their family history regarding liver dysfunction during pregnancy.
Neonatal stomach volume and physiology suggest feeding at 1‐h intervals
Authors: Bergman Nils J
Published: May 2013

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There is insufficient evidence on optimal neonatal feeding intervals, with a wide range of practices. The stomach capacity could determine feeding frequency. A literature search was conducted for studies reporting volumes or dimensions of stomach capacity before or after birth. Six articles were found, suggesting a stomach capacity of 20 mL at birth.

Conclusion

A stomach capacity of 20 mL translates to a feeding interval of approximately 1 h for a term neonate. This corresponds to the gastric emptying time for human milk, as well as the normal neonatal sleep cycle. Larger feeding volumes at longer intervals may therefore be stressful and the cause of spitting up, reflux and hypoglycaemia. Outcomes for low birthweight infants could possibly be improved if stress from overfeeding was avoided while supporting the development of normal gastrointestinal physiology. Cycles between feeding and sleeping at 1‐h intervals likely meet the evolutionary expectations of human neonates.
Long‐term outcome following pneumatic dilatation as initial therapy for idiopathic achalasia: an 18‐year single‐centre experience
Authors: Elliott T. R. , Wu P. I. , Fuentealba S. , Szczesniak M. , de Carle D. J. , Cook I. J.
Published: May 2013

Background

Relapse after treatment for idiopathic achalasia is common and long‐term outcome data are limited.

Aim

To determine the cumulative relapse rate and long‐term outcome after pneumatic dilatation (PD) for achalasia in a tertiary referral centre.

Methods

A retrospective study of 301 patients with achalasia treated with PD as first‐line therapy. Short‐term outcome was measured at 12 months. Long‐term outcome was assessed in those who were in remission at 12 months by cumulative relapse rate and cross‐sectional analysis of long‐term remission rate regardless of any interval therapy, using a validated achalasia‐specific questionnaire.

Results

Eighty‐two percent of patients were in remission 12 months following initial PD. Relapse rates thereafter were 18% by 2 years; 41% by 5 years and 60% by 10 years. Whilst 43% patients underwent additional treatments [PD (29%), myotomy (11%) or botulinum toxin (3%)] beyond 12 months, 32% of those who had not received interval therapy had relapsed at cross‐sectional analysis. After a mean follow‐up of 9.3 years, regardless of nature, timing or frequency of any interval therapy, 71% (79/111) patients were in remission. The perforation rate from PD was 2%. Chest pain had a poor predictive value (24%) for perforation.

Conclusions

Long‐term relapse is common following pneumatic dilatation. While on‐demand pneumatic dilatation for relapse yields a good response, one‐third of relapsers neither seek medical attention nor receive interval therapy. Close follow‐up with timely repeat dilatation is necessary for a good long‐term outcome. Given the poor predictive value of chest pain for perforation, routine gastrografin swallow is recommended postdilatation.