bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversal of Neuromuscular Blockade with Sugammadex at the Reappearance of Four Twitches to Train-of-four Stimulation
Authors: Pongrácz Adrienn , Szatmári Szilárd , Nemes Réka , Fülesdi Béla , Tassonyi Edömér
Published: May 2013

Background:

Doses of sugammadex required to reverse deep, moderate, and shallow rocuronium-induced neuromuscular blockade have been established. However, no adequate doses for the reversal of reappearance of four twitches of train-of-four (TOF) stimulation (threshold TOF-count-four) have been established.

Methods:

This single-center, randomized, controlled, double-blind, four-groups parallel-arm study included 80 patients undergoing general anesthesia with propofol, sevoflurane, fentanyl, and rocuronium. Neuromuscular monitoring was performed with calibrated acceleromyography. Once rocuronium-induced neuromuscular blockade recovered spontaneously to threshold TOF-count-four, patients randomly received 0.5, 1.0, 2.0 mg/kg of sugammadex or 0.05 mg/kg of neostigmine. The time between study drug injection and reversal of TOF ratios to 1.0 was measured. Rapid reversal (≤2.0 min average, upper limit of 5.0 min) was the primary endpoint and slower reversal (≤5.0 min average, upper limit of 10 min) was the secondary endpoint of the study.

Results:

Sugammadex, in doses of 1.0 and 2.0 mg/kg, reversed threshold TOF-count-four to TOF ratios of 1.0 in 2.1 ± 0.8 min (mean ± SD) and 1.8 ± 0.9 min, respectively. Sugammadex, 0.5 mg/kg, induced a similar degree of reversal in 4.1 ± 1.9 min (P < 0.001 vs. 1.0 and 2.0 mg/kg). Neostigmine, 0.05 mg/kg, reversed TOF ratios to 1.0 in 8.5 ± 3.5 min (P < 0.001 vs. sugammadex groups).

Conclusion:

Sugammadex, 1.0 mg/kg, rapidly and effectively reverses rocuronium-induced block that has recovered spontaneously to a threshold TOF-count-four. A dose of 0.5 mg/kg was equally effective, but satisfactory antagonism took as long as 8 min to take place.
Two novel ascomycetous yeast species, Wickerhamomyces scolytoplatypi sp. nov. and Cyberlindnera xylebori sp. nov., isolated from ambrosia beetle galleries
Authors: Ninomiya Shinya , Mikata Kozaburo , Kajimura Hisashi , Kawasaki Hiroko
Published: May 2013

Thirteen strains of yeasts were isolated from ambrosia beetle galleries at several sites in Japan. Based on the morphological and biochemical characteristics and phylogenetic analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene of the yeasts, 10 strains were shown to represent a novel species of the genus Wickerhamomyces, described as Wickerhamomyces scolytoplatypi sp. nov. (type strain NBRC 11029T = CBS 12186T), and were closely related to Wickerhamomyces hampshirensis. The three other strains represented a novel species of the genus Cyberlindnera, described as Cyberlindnera xylebori sp. nov. (type strain NBRC 11048T = CBS 12187T), and were closely related to Cyberlindnera euphorbiiphila. It is suggested that these species are associated with ambrosia beetles and we consider ambrosia beetle galleries as good sources of novel yeasts.
Saccharomonospora

amisosensis sp. nov., isolated from deep marine sediment
Authors: Veyisoglu Aysel , Sazak Anil , Cetin Demet , Guven Kiymet , Sahin Nevzat
Published: May 2013

A novel actinomycete, strain DS3030T, was isolated from a deep sediment sample, collected from the southern Black Sea coast, Turkey, and was examined using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain DS3030T was shown to belong to the genus

Saccharomonospora

and to be related most closely to

Saccharomonospora marina

XMU15T (99.6 % similarity). Sequence similarities with other strains of the genus

Saccharomonospora

were lower than 97.0 %. The organism had chemical and morphological features typical of the genus

Saccharomonospora

. The cell wall of the novel strain contained meso-diaminopimelic acid, arabinose and galactose as diagnostic sugars. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The predominant menaquinone was MK-9(H4). Major fatty acids were iso-C16 : 0, iso-C16 : 0 2-OH and C16 : 1
cis 9. Phenotypic data clearly distinguished the new isolate from its closest relative,

S. marina

XMU15T. The combined genotypic and phenotypic data and low DNA–DNA relatedness with its closest related strain reveal that strain DS3030T represents a novel species of the genus, for which the name

Saccharomonospora

amisosensis sp. nov. is proposed. The type strain is DS3030T ( = DSM 45685T = KCTC 29069T = NRRL B-24885T).
Involvement of AtPolλ in the Repair of High Salt- and DNA Cross-Linking Agent-Induced Double Strand Breaks in Arabidopsis
Authors: Roy Sujit , Choudhury Swarup Roy , Sengupta Dibyendu N. , Das Kali Pada
Published: May 2013

DNA polymerase λ (Pol λ) is the sole member of family X DNA polymerase in plants and plays a crucial role in nuclear DNA damage repair. Here, we report the transcriptional up-regulation of Arabidopsis (Arabidopsis thaliana) AtPolλ in response to abiotic and genotoxic stress, including salinity and the DNA cross-linking agent mitomycin C (MMC). The increased sensitivity of atpolλ knockout mutants toward high salinity and MMC treatments, with higher levels of accumulation of double strand breaks (DSBs) than wild-type plants and delayed repair of DSBs, has suggested the requirement of Pol λ in DSB repair in plants. AtPolλ overexpression moderately complemented the deficiency of DSB repair capacity in atpolλ mutants. Transcriptional up-regulation of major nonhomologous end joining (NHEJ) pathway genes KU80, X-RAY CROSS COMPLEMENTATION PROTEIN4 (XRCC4), and DNA Ligase4 (Lig4) along with AtPolλ in Arabidopsis seedlings, and the increased sensitivity of atpolλ-2/atxrcc4 and atpolλ-2/atlig4 double mutants toward high salinity and MMC treatments, indicated the involvement of NHEJ-mediated repair of salinity- and MMC-induced DSBs. The suppressed expression of NHEJ genes in atpolλ mutants suggested complex transcriptional regulation of NHEJ genes. Pol λ interacted directly with XRCC4 and Lig4 via its N-terminal breast cancer-associated C terminus (BRCT) domain in a yeast two-hybrid system, while increased sensitivity of BRCT-deficient Pol λ-expressing transgenic atpolλ-2 mutants toward genotoxins indicated the importance of the BRCT domain of AtPolλ in mediating the interactions for processing DSBs. Our findings provide evidence for the direct involvement of DNA Pol λ in the repair of DSBs in a plant genome.
Servant leadership in English sixth form colleges: what do teachers tell us?
Authors: Stoten David William
Published: May 2013

Purpose

The purpose of this paper is to investigate whether servant leadership can be applied to college management. The research methodology involved questionnaire and co‐constructed discussion eliciting the views of teachers on how they interpret leadership in a sixth form college. Three other models of leadership were discussed along with servant leadership. The results suggest that servant leadership is the least recognised form of leadership in colleges.

Design/methodology/approach

The research methodology involved two phases. The first phase involved a probing questionnaire that elicited teachers’ views on institutional leadership and enquired about the purpose of leadership. This pilot questionnaire was followed up with a series of co‐constructed discussions with teachers.

Findings

The findings suggest that servant leadership is not prevalent within the sixth form college sector. Transactional leadership was the most identified form of organisational leadership, with distributed and transformational models coming ahead of servant leadership. These outcomes highlight the shared instrumentalism that exists within colleges as they confront the developing education market in the UK.

Research limitations/implications

This case study, albeit echoing other larger investigations, was undertaken at a single college and is therefore limited in its generalisability.

Originality/value

There is very little research undertaken into the leadership and management of sixth form colleges, and even less on the relevance of servant leadership to the education sector. This paper offers a tentative view of how teachers view leadership and the dominance of transactional leadership in the college system.
Sustainable leadership and future‐oriented decision making in the educational governance – a Finnish case
Authors: Metsämuuronen Jari , Kuosa Tuomo , Laukkanen Reijo
Published: May 2013

Purpose

During the new millennium the Finnish educational system has faced a new challenge: how to explain glorious PISA results produced with only a small variance between schools, average national costs and, as regards the average duration of studies, relatively efficiently. Explanations for this issue can be searched for in many different ways. The purpose of the article is to show what kind of sustainable leadership in the educational governance can be seen behind the high level results in Finland.

Design/methodology/approach

The future‐oriented actions are discussed in the article alongside some relevant cultural prerequisites that have enabled effective changing processes. Finally, two cases of recent future‐oriented actions in the Finnish educational governance are given as examples.

Findings

Sustainable leadership can be seen as a long series of several future‐oriented decisions and actions, such as uniforming the system, offering highly demanding education to all, strategic decisions concerning the information society, as well as some other great political decisions concerning education.

Research limitations/implications

It may not be easy to reproduce the same high‐level results as in Finland in any other country. However, several developing countries could benefit from the future‐oriented ethos of Finland.

Practical implications

This article gives hints what kinds of future‐oriented actions can be launched at a national level.

Social Implications

Future orientation leads to long‐term policies in education. This enables long‐term development in the educational sector which may enhance the social cohesion in the societies.

Originality/value

Though the Finnish experiences may be unique in the international settings, the future‐orientation is of uttermost importance when wanting to develop the educational systems in any country. Hence the results may give a valuable insight to understand a successful case of educational governance.
Post materialist values and entrepreneurship: a multilevel approach
Authors: Morales Carlos E. , Holtschlag Claudia
Published: May 2013

Purpose

Postmaterialist values (autonomy, self‐expression, fulfilment of personal goals) have been shown to predict entrepreneurship at the country level. This paper aims to expand previous research by testing the relationship between postmaterialism and entrepreneurship at the individual level across 39 countries.

Design/methodology/approach

In a series of multilevel models, with individuals nested within countries, the paper tests whether individuals’ postmaterialist values predict the probability of becoming an entrepreneur after controlling for income level, age, gender and education level. To do this, Inglehart's 12‐item Postmaterialism‐index was used. Data was taken from the 1999‐2004 database of the World Value Survey on approximately forty‐five thousand subjects from 39 countries. Models with random intercepts and random slopes were calculated.

Findings

This paper presents evidence on three issues: postmaterialism decreases a person's likelihood of becoming an entrepreneur; the effect of postmaterialism on entrepreneurship varies across countries; and this effect is more negative in countries with high levels of entrepreneurship.

Practical implications

Theoretical: individuals with materialist values are more likely to be entrepreneurs than postmaterialist individuals. This finding provides support to the hypothesis that entrepreneurs are basically economically driven people. Practical: The efficacy of public policies to promote entrepreneurial activity could be overshadowed by more deeply‐rooted cultural orientations, postmaterialism in this case.

Originality/value

The relationship between postmaterialism and entrepreneurship has been studied previously using countries as the unit of analysis; this paper's main contribution is that it expands this line of research to the individual level of analysis.
An evaluation of the staff training within the trauma and self injury (TASI) programme in the National High Secure Healthcare Service for Women (NHSHSW)
Authors: Robertson Kate , Elcock Sue , Milburn Chris , Annesley Phyllis , Jones Jane , Völlm Birgit A.
Published: May 2013

Purpose

Patients in the National High Secure Healthcare Service for Women have a high prevalence of trauma and self injury. This highlights the need for specialised training of staff dealing with such women. The aim of this study was to evaluate the trauma and self injury (TASI) training programme on staff knowledge and skills.

Design/methodology/approach

A total of 135 nurses and nursing assistants participated in the TASI two‐day training course. Questionnaires allowing for quantitative and qualitative data collection were completed before and after the training. Training and confidence levels in dealing with women who self‐harm prior to the training were identified and the impact of the programme was assessed.

Findings

The majority of staff had not received any previous training on trauma and self injury. There was an increased level of confidence in working with trauma and self injury following training and staff reported an increased ability to ask for support. Self‐perceived competence improved to a greater extent in those who had not received previous training compared to those who had.

Research limitations/implications

The authors' data is limited to self‐report. Future research should use objective measures to evaluate the impact of staff training.

Practical implications

A relatively short training programme focusing on trauma and self injury appears to improve staff confidence, understanding and competence in working with women patients in a high secure setting. Similar training programmes might also be beneficial in different patient groups with complex backgrounds and behaviours.

Originality/value

This is the first report on a training programme focussing on women in high secure care who self‐harm and have experienced trauma.
How do different business models affect intellectual capital?
Authors: Liang Chiung‐Ju , Chen Tzu‐Yin , Lin Ying‐Li
Published: May 2013

Purpose

The purpose of this paper is to investigate whether value‐creating activities and intellectual capital (IC) accumulation are affected by different business models.

Design/methodology/approach

Field visitations and interview‐based questionnaires are used for data collection. This study uses the structural equation model to examine Taiwanese original equipment manufacturers (OEMs) and original brand manufacturers (OBMs) in China.

Findings

Empirical results show that Taiwanese OEMs and OBMs adopt different combinations of value‐creating activities, which results in differences in IC accumulation. Taiwanese OEMs have engaged in manufacturing and innovation activities, and have created process and innovation capitals. By contrast, Taiwanese OBMs have developed their marketing channels, human resources, innovation centres, and social networks, and have accumulated their human, customer, process and innovation capitals.

Practical implications

Taiwanese OEMs have cultural advantages and have built productive infrastructure in China. Therefore, these enterprises should transform their business models into OBMs to enhance their market performance. Foreign investors could leverage the experiences and IC of Taiwanese enterprises to make their investments run more smoothly.

Originality/value

This paper contributes to the existing literature by investigating relationships among business models, value‐creating activities, and IC. This study also provides useful guidance for enterprises considering investing in China and for academics researching in this area.
A template for integrated reporting
Authors: Abeysekera Indra
Published: May 2013

Purpose

The purpose of this paper is to outline the concept of integrated reporting and to propose a template for integrated reporting in organisations.

Design/methodology/approach

The approach to the conceptual model is founded on concepts proposed on integrated reporting by the King Report on Governance for South Africa (King III), and the International Integrated Reporting Council in the UK.

Findings

The integrated report should explain the story of reaching the organisation's vision, underpinned by its values, enacted by management, monitored by governance, and using facets of resources relating to financial capital, intellectual capital, social capital, and environmental capital.

Practical implications

The paper proposes an integrated reporting framework, and provides an example of a template to be used in organisations.

Originality/value

To the best of the author's knowledge, this is the first academic paper that provides a coherent framework on integrated reporting, with a template.
Business co‐creativity with an eye towards MENA
Authors: Baker Laura , Sonnenburg Stephan
Published: May 2013

Purpose

The purpose of the paper is multifold. First, an understanding for creativity in an organizational setting is elaborated. Second, the emergence of creativity as a universal phenomenon is discussed. Third, an integrated framework focusing upon processes and group composition to affect co‐creativity is developed. Additionally, this paper begins an intercultural exploration for business and managerial purposes in the Middle East and North Africa (MENA).

Design/methodology/approach

The methodology is a literature search of theoretical and empirical plus cultural studies to support this paper that includes a process model for future application. Since there are cultural studies available mostly about individual countries in the Arab world the cultural variables will be isolated and they will be referred to in order to exemplify an assessment of creativity in MENA.

Findings

This paper contributes to the literature by exploring answers to the business world's questions of what could be barriers and enhancers of creativity not only in the Western world but also in the Arab world. In order to stimulate co‐creativity as quickly and as effectively as possible in the Arab world, there must be flexibility, generosity, loyalty, trust, fairness, shared communication and synthesized ideas. Most probably these factors are universal for co‐creativity.

Originality/value

Organizations are striving for transformation in order to be creative and/or innovative. Precisely, transformation needs co‐creativity as most transforming acts in organizations are based on interactive situations. However until now, it is not clear what co‐creativity is and how to foster co‐creativity. The value of this paper is to integrate a universal definition and understanding of co‐creativity while examining the cultural context of MENA.
Location and operation mode decision making in the Middle East: a case study approach
Authors: Rogmans Tim
Published: May 2013

Purpose

The purpose of this paper is to develop and test propositions on location and entry mode decision making by foreign direct investors in the Middle East region.

Design/methodology/approach

Case study approach, based on in‐depth interviews with decision makers of multinational companies operating in the Middle East.

Findings

The results show that foreign investors in the Middle East prefer to maintain the highest level of ownership and control permitted in a country, even in the face of political risk.

Originality/value

Location and entry mode decision making has typically been studied using quantitative methods. This research uses a case study approach and develops a new model of entry mode decision making, demonstrating that experienced foreign investors do not view joint ventures as an effective mechanism to manage political risk, but prefer to keep political risk management in‐house.
The application of extended Kalman filtering to autonomous formation flight of small UAV system
Authors: Ding Yi‐Ren , Liu Yi‐Chung , Hsiao Fei‐Bin
Published: May 2013

Purpose

The purpose of this paper is to present a small UAV system with autonomous formation flight capability, the Swallow UAV system, and the application of an extended Kalman filter (EKF) based augmentation method to reduce the impact of data link loss, which will fail the formation flight algorithm of the system.

Design/methodology/approach

The hardware of the Swallow UAV system is composed of two aircraft and a set of ground control station for leader‐wingman formation flight. A hardware‐in‐the‐loop simulation environment is build to support the system development. Fuzzy logic control method is applied to the guidance, navigation, and control system of leader and wingman aircraft. The leader system is designed with waypoint navigation and circle trajectory tracking functions to make the aircraft stay in visual range autonomously for safety. The wingman system is designed with formation flight functionality. However, the relative position and velocity are derived from the wireless data link transmitted leader navigation information. It is vulnerable to the data link loss. The EKF based leader motion estimator (LME) is developed to estimates the leader position when the data link broke, and corrects the estimation when the data link is available.

Findings

The designed LME is flight tested, and the results show that it woks properly with sound performance that the estimation error of relative position within 3 meters, relative velocity within 1.3 meters, and leader attitude within 1.6 degrees in standard deviation.

Originality/value

The research implements the autonomous formation flight capability with the EKF based LME on a small UAV system.
A multi‐level perspective on equal employment opportunity for women in Pakistan
Authors: Ali Faiza
Published: May 2013

Purpose

Informed by a relational theorisation of equal opportunity, this paper seeks to focus on multi‐level experiences and observations of women working in Pakistan's formal employment sector considering issues and challenges facing them at three levels of analysis, i.e. macro‐societal, meso‐organisational and micro‐individual.

Design/methodology/approach

Drawing on in‐depth qualitative interviews with 30 working women in Lahore, the paper examines multi‐level issues of women working in Pakistani organisations.

Findings

The study reveals that focusing exclusively on organisations and holding them solely accountable for equal opportunity may be inadequate as organisational structures and routines of equal opportunity are affected by both macro‐societal factors (e.g. legal, socio‐cultural) and micro‐individual factors (e.g. intersectionality, agency). In particular, the study highlights unique socio‐cultural and structural challenges facing working women in Pakistan and the ways in which these women are able to negotiate and overcome some of these challenges.

Research limitations/implications

The study is based on six Pakistani organisations located in Lahore, Punjab, and may not be generalized to represent issues and challenges of equal opportunity in other provinces of Pakistan.

Practical implications

The paper suggests that employers may pay special attention to socio‐cultural issues facing women to promote gender equality at the workplace.

Originality/value

The study contributes to the equal employment opportunity literature by exploring gender equality issues in a Muslim majority country's context.
Sodium thiosulfate in the treatment of non‐uremic calciphylaxis
Authors: Ning Matthew S. , Dahir Kathryn M. , Castellanos Emily H. , McGirt Laura Y.
Published: May 2013

Calciphylaxis is a metastatic calcification‐induced vasculopathy that results in the occlusion of small blood vessels. Although calciphylaxis is normally associated with end‐stage renal disease, calciphylaxis from non‐uremic origin occurs as well. While the number of reports continues to increase, a standard treatment for non‐uremic calciphylaxis has yet to be established. Sodium thiosulfate (STS), which has been proven to be effective in the treatment of uremic calciphylaxis, shows promise; however, reports of its use in non‐uremic cases are limited. We describe a case of non‐uremic calciphylaxis in a patient with normal renal and parathyroid function who had complete resolution of disease after treatment with STS, and we review similar cases in the published work. Based on the successful outcomes detailed in this case series, STS appears to be an effective therapy for non‐uremic calciphylaxis.
Case of diffuse cutaneous systemic sclerosis with anti‐Ku and anti‐centromere antibodies
Authors: Ohashi Sonoko , Ueda‐Hayakawa Ikuko , Isei Taiki , Okamoto Hiroyuki
Published: May 2013

We report the case of a 58‐year‐old man who had an ulcer on the right middle finger that was cured by surgery 4 years before consultation with our department. A few years after the surgery, he noticed recurrence of the ulcer and sclerosis of the skin. At the initial examination, skin sclerosis was observed from the fingers to the upper arms and from the feet to the thighs. Pitting scars on the fingertips and punctured hemorrhages of the nail‐fold capillaries were also present. Gastroscopy showed slight reflex esophagitis. Laboratory findings were positive for antinuclear antibody (ANA; 1:640) with a speckled and discrete speckled pattern. Anti‐topoisomerase I (anti‐topo I) antibody and anti‐RNA polymerase III were negative, but anti‐centromere antibody was positive in an enzyme‐linked immunosorbent assay. Anti‐Ku antibody was positive in an immunoprecipitation assay using extracts of the leukemia cell line K562. Therefore, the patient was diagnosed with diffuse cutaneous systemic sclerosis with anti‐Ku and anti‐centromere antibodies. Treatment with an oral antiplatelet agent, vitamin E, a proton pump inhibitor, and i.v. lipoprostaglandin E1 were started. Subsequently, there has been repeated recurrence of finger ulcers, but no muscle involvement has been detected since his first visit. This is the first reported case of systemic sclerosis with anti‐Ku and anti‐centromere antibodies.
Reproductive failure of a human‐tolerant species, the American kestrel, is associated with stress and human disturbance
Authors: Strasser Erin H. , Heath Julie A.
Published: May 2013

The rapid increase of human activity in wild and developed areas presents novel challenges for wildlife. Some species may use human‐dominated landscapes because of favourable resources (e.g. high prey availability along roadsides); however, use of these areas may increase exposure to anthropogenic stressors, such as human disturbance or noise, which can negatively affect reproduction or survival. In this case, human‐dominated landscapes may act as an ecological trap.

We evaluated whether American kestrel Falco sparverius reproductive failure was associated with human disturbance (traffic conditions and land development) or other common predictors of reproductive outcome, such as habitat and clutch initiation date. Also, we examined relationships among human disturbance, corticosterone (CORT) concentrations and nest abandonment to explore potential mechanisms for stress‐induced reproductive failure.

Twenty‐six (36%) of 73 kestrel nesting attempts failed and 88% of failures occurred during incubation. Kestrels nesting in higher disturbance areas were 9·9 times more likely to fail than kestrels nesting in lower disturbance areas. Habitat and clutch initiation date did not explain reproductive outcome.

Females in higher disturbance areas had higher CORT and were more likely to abandon nests than females in lower disturbance areas. There was no relationship between male CORT and disturbance or abandonment. Females spent more time incubating than males and may have had more exposure to anthropogenic stressors. Specifically, traffic noise may affect a cavity‐nesting bird's perception of the outside environment by masking auditory cues. In response, incubating birds may perceive a greater predation risk, increase vigilance behaviour, decrease parental care, or both.

Synthesis and applications. Proximity to large, busy roads and developed areas negatively affected kestrel reproduction by causing increased stress hormones that promoted nest abandonment. These results demonstrate that species presence in a human‐dominated landscape does not necessarily indicate a tolerance for anthropogenic stressors. Managers should carefully consider or discourage projects that juxtapose favourable habitat conditions with areas of high human activity to decrease risk of ecological traps. Noise mitigation, while locally effective, may not protect widespread populations from the pervasive threat of traffic noise. Innovative engineering that decreases anthropogenic noise at its source is necessary.
Community assembly along a soil depth gradient: contrasting patterns of plant trait convergence and divergence in a Mediterranean rangeland
Authors: Bernard‐Verdier Maud , Navas Marie‐Laure , Vellend Mark , Violle Cyrille , Fayolle Adeline , Garnier Eric
Published: May 2013

Understanding how environmental factors drive plant community assembly remains a major challenge in community ecology. The strength of different assembly processes along environmental gradients, such as environmental filtering and functional niche differentiation, can be quantified by analysing trait distributions in communities. While environmental filtering affects species occurrence among communities, functional divergence or convergence is strongly related to species abundances within communities, which few studies have taken into account. We examine the trait‐mediated effect of these two processes along a stress‐resource gradient.

We measured species abundances and the distributions of eight traits related to vegetative and regenerative phases in plant communities along a gradient of soil depth and resource availability in Mediterranean rangelands. We quantified environmental filtering, defined as a local restriction of trait range, and trait divergence, based on abundance‐weighted trait variance, using a two‐step approach with specifically designed null models.

Communities presented a clear functional response to the soil gradient, as evidenced by strong trends in community‐weighted trait means. We detected environmental filtering of different traits at both ends of the gradient, suggesting that, contrary to widespread expectations, trait filtering may not necessarily be the result of abiotic filtering under harsh conditions but could likely also result from biotic interactions in productive habitats.

We found marked shifts in trait abundance distributions within communities along the gradient. Vegetative traits (e.g. leaf dry matter content) diverged on shallow soils, reflecting the coexistence of distinct water‐ and nutrient‐use strategies in these constrained habitats and converged with increasing soil resource availability. By contrast, regenerative traits (e.g. seed mass) tended to diverge towards deeper soils, while plant reproductive heights diverged all along the gradient.

Synthesis: Our study highlights how the combination of abundance data with traits capturing different functional niches is critical to the detection of complex functional responses of plant communities to environmental gradients. We demonstrate that patterns of trait divergence and filtering are strongly contingent on both trait and environment such that there can be no expectation of a simple trend of increasing or decreasing functional divergence along a gradient of resource availability.
Flowers attract weaver ants that deter less effective pollinators
Authors: Gonzálvez Francisco G. , Santamaría Luis , Corlett Richard T. , Rodríguez‐Gironés Miguel A.
Published: May 2013

1. Many flowers produce ant‐repellent substances that prevent ants from discouraging pollinator visits. When a flower's most effective pollinator is unaffected by predatory ants, however, flowers should benefit from the presence of ants that deter less effective pollinators from consuming resources.

2. Behavioural assays revealed that Melastoma malabathricum flowers, pollinated by large carpenter bees, Xylocopa spp., produce ant attractants that recruit weaver ants, Oecophylla smaragdina.

3. The presence of ants was associated with an increase in the reproductive success of M. malabathricum flowers. This outcome likely resulted from the filtering effect of ants on the community of flower visitors: ants deter less effective pollinators and attract Xylocopa bees through an indirect effect on resource depletion.

4. Synthesis. Although plant–pollinator interactions are classified as mutualisms, not all flower visitors are effective pollinators, and some can be parasites or conditional parasites. As a result, predators that deter flower visitors can have positive or negative effects on plant fitness, depending on whether they deter all visitors or a subset of them, and on the relative effectiveness of deterred and undeterred visitors.
Species specific growth responses of black spruce and trembling aspen may enhance resilience of boreal forest to climate change
Authors: Drobyshev Igor , Gewehr Sylvie , Berninger Frank , Bergeron Yves
Published: May 2013

To understand how the future climate will affect the boreal forest, we studied growth responses to climate variability in black spruce (Picea mariana [Mill.] B.S.P.) and trembling aspen (Populus tremuloides Michx.), two major co‐occurring boreal tree species of the eastern Canadian boreal forest.

We analysed climate–growth interaction during (i) periods of non‐anomalous growth and (ii) in years with strong growth anomalies. We utilized paired tree‐level data for both growth and soil variables, which helped ensure that the studied growth variability was a function of species‐specific biology, and not of within stand variation in soil conditions.

Redundancy analysis conducted on spruce and aspen tree ring chronologies showed that their growth was affected differently by climate. During non‐anomalous years, growth of spruce was favoured by cooler temperatures and wetter conditions, while aspen growth was favoured by higher temperatures and drier conditions.

Black spruce and trembling aspen also showed an inverse pattern in respect to expression of growth anomalies (pointer years). A negative growth anomaly in spruce tended to be associated with positive ones in aspen and vice versa. This suggested that spruce and aspen had largely contrasting species‐specific responses to both ‘average’ weather conditions and extreme weather events.

Synthesis. Species‐specific responses to environmental variability imply that tree responses to future climate will likely be not synchronized among species, which may translate into changes in structure and composition of future forest communities. In particular, we speculate that outcome of climate change in respect to relative abundance of black spruce and trembling aspen at the regional levels will be highly dependent on the balance between increasing temperatures and precipitation. Further, species‐specific responses of trees to annual climate variability may enhance the resilience of mixed forests by constraining variability in their annual biomass accumulation, as compared with pure stands, under periods with high frequency of climatically extreme conditions.
Integrating trait‐ and niche‐based approaches to assess contemporary evolution in alien plant species
Authors: Hulme Philip E. , Barrett Spencer C. H.
Published: May 2013

Two primary lines of indirect evidence for contemporary evolution in alien species are based on differences between native and introduced ranges in one or more functional traits or a shift in environmental niche. Although the integration of trait and environmental niche perspectives is increasingly recognised as a key to understanding the role of life‐history evolution in range‐shifting populations, there has been no attempt to bring together these perspectives on the contemporary evolution of alien plant species.

We develop a set of scenarios that contrast trait–environment relationships observed in the field for alien species in the native and introduced range, and explore how they might be shaped by contemporary evolution. In each case, the limitations of uniquely trait or environmental niche perspectives are highlighted. The scenarios are examined in relation to long‐term trends in covariation between temperature and first flowering date of European plant species introduced into the USA. Support for four of the scenarios is found.

Field studies examining how species traits respond to environmental variation along natural gradients cannot by themselves distinguish relationships arising from genetic variation, phenotypic plasticity or genetic variation for such plasticity. This is best assessed by reciprocal transplant experiments. However, trait–environment relationships provide a basis for better targeted common garden studies that are more hypothesis driven and that pinpoint the traits of interest, ascertain the appropriate selection gradients and the range over which they need to be observed, as well as identify candidate species for further study.

Synthesis. The need to improve species distribution models through a better understanding of underlying ecological and evolutionary processes makes assessments of trait–environment relationships, in both the native and introduced ranges, significant. They are of paramount importance when explaining the differential success of alien plants in novel environments as well as when predicting the potential for future range shifts following introduction. The current paucity of such comparisons represents a significant gap in our understanding of biological invasions.
Effects of topography on structuring local species assemblages in a Sri Lankan mixed dipterocarp forest
Authors: Punchi‐Manage Ruwan , Getzin Stephan , Wiegand Thorsten , Kanagaraj Rajapandian , Savitri Gunatilleke C. V. , Nimal Gunatilleke I. A. U. , Wiegand Kerstin , Huth Andreas
Published: May 2013

One of the primary goals in community ecology is to determine the relative importance of processes and mechanisms that control biodiversity. Here, we examined habitat‐driven species assemblages and species distribution patterns as well as their temporal variations for three life stages of two censuses of a 25‐ha mixed dipterocarp forest at Sinharaja (Sri Lanka).

Our general objective was to find out whether the species assemblages and associated habitat types changed with life stage, spatial scale and species attributes. We also analyse whether the habitat types were related to certain indicator species. Habitat types were determined with multivariate regression tree analyses driven by topographic variables.

We found species assemblages associated with five distinct habitat types that appeared consistently for all life stages of the two censuses. These habitats were related to ridge‐valley gradients and a pronounced contrast in south‐west versus north‐east aspect. Habitat‐driven structuring was weak at the recruit stage but strong in the juvenile and adult stages. The species assemblage variance explained by topographic variables for different life stages ranged between 10% for recruits and 23% for juveniles.

The species assemblages determined for different spatial scales (10, 20, 50 m) showed similar habitat partitioning, but the variance explained by the topographic variables increased in all life stages with spatial scale. This could be due to the homogenizing effect of topographic variables at the larger scales and unaccounted environmental variation at the smaller scales. The number of indicator species identified in the two censuses was higher in the juvenile stage than in the adult stage, and nearly all indicator species in the adult stage were also indicator species in the juvenile stage.

Synthesis. Our study showed that approximately 75% of the variance in local species composition is unexplained. This may be due to spatially structured processes such as dispersal limitation, unaccounted biotic and abiotic environmental variables, and stochastic effects, but only 25% were due to topographic habitat association. Although the pronounced ridge‐valley gradient and contrast of south‐west versus north‐east aspect created consistent habitats, our results suggest that local species assemblages at Sinharaja forest are jointly shaped by neutral and niche processes.
Tree species diversity increases fine root productivity through increased soil volume filling
Authors: Brassard Brian W. , Chen Han Y. H. , Cavard Xavier , Laganière Jérôme , Reich Peter B. , Bergeron Yves , Paré David , Yuan Zhiyou
Published: May 2013

Although fine roots (< 2 mm in diameter) account for a major share of the production of terrestrial ecosystems, diversity effects on fine root productivity and their mechanisms remain unclear.

We hypothesized that: (i) fine root productivity increases with tree species diversity, (ii) higher fine root productivity is a result of greater soil volume filling due to species‐specific patterns of root placement and proliferation, and (iii) differences in fine root productivity and soil volume filling associated with tree species diversity are more pronounced in summer when plants are physiologically active and demand for water and nutrients is at its greatest.

We investigated the effects of tree species diversity on fine root productivity and soil volume filling of boreal forest stands that have grown naturally for 85 years on similar sites.

Annual fine root production was 19–83% higher in evenly mixed‐ than single‐species‐dominated stands, and increased with tree species evenness, but not tree species richness. Fine root biomass was higher in evenly mixed‐ than single‐species‐dominated stands in summer months, but not in spring or fall. Higher fine root productivity in evenly mixed‐ than single‐species‐dominated stands was realized by filling more soil volume horizontally and vertically in the forest floor in the mixtures of deep‐ and shallow‐rooted species vs. the deeper mineral soil in the mixtures of deep‐rooted species.

Synthesis. Our results provide some of the first direct evidence for below‐ground species complementarity in heterogeneous natural forests, by demonstrating that tree species evenness increases fine root productivity by filling/exploiting the soil environment more completely in space and time, driven by differences in the inherent rooting traits of the component species and variations of root growth within species.
Novel chemical weapon of an exotic macroalga inhibits recruitment of native competitors in the invaded range
Authors: Svensson J. Robin , Nylund Göran M. , Cervin Gunnar , Toth Gunilla B. , Pavia Henrik
Published: May 2013

Allelopathy is an important non‐resource interaction in terrestrial plant communities that may affect invasions by non‐indigenous plants. The ‘novel weapons hypothesis’ (NWH) predicts that non‐indigenous plants will become invasive if they have allelopathic compounds that assemblages in the new range are not adapted to. Recently, the non‐indigenous, chemically rich macroalga Bonnemaisonia hamifera (Hariot) has become one of the most abundant filamentous red algae in Scandinavian waters.

We used B. hamifera to specifically test the aspect of the NWH that concerns invasion success based on novel allelochemicals in the invaded range. Allelopathic interactions were tested through effects on the growth rate of adult native macroalgae in co‐cultures with B. hamifera and through the settlement success of native macroalgal propagules and microalgae on surfaces coated with 1,1,3,3‐tetrabromo‐2‐heptanone. We also investigated whether 1,1,3,3‐tetrabromo‐2‐heptanone can be transferred from B. hamifera to its native host algae, as a means of pre‐emptive competition.

The settlement of native macroalgal propagules and microalgae was strongly inhibited on surfaces coated with 1,1,3,3‐tetrabromo‐2‐heptanone at ecologically relevant concentrations, but there were no effects of adult B. hamifera on growth rates of adults of the six native naturally co‐occurring species. The compound was shown to be transferred from B. hamifera to the surface of its native host algae at inhibitory concentrations in both laboratory and field experiments.

By inhibiting the settlement of propagules on its thallus and on surrounding surfaces, B. hamifera achieves a competitive advantage over native macroalgae, a finding that parallels previous reports on soil‐ and litter‐mediated allelopathic interactions among vascular plants. Because competition for available substrata in marine benthic systems is intense, the ability to reserve space may be vital for B. hamifera's successful invasion. This is the first example of an allelopathic compound that can be transferred by direct contact from an exotic to a native species, with an active and unaltered function.

Synthesis. Our results clearly show that the main secondary metabolite of the invasive red alga B. hamifera has strong allelopathic effects towards native competitors, suggesting that its novel chemical weapon is important for the highly successful invasion of new ranges.
Hydrological consequences of declining land use and elevated CO2 in alpine grassland
Authors: Inauen Nicole , Körner Christian , Hiltbrunner Erika
Published: May 2013

Large areas of alpine pastures and meadows currently face declining land use or abandonment, which leads to tall‐grass transition ecosystems with higher leaf area index (LAI), potentially increased evapotranspiration (ET) and thus, reduced water yield. Elevated atmospheric CO2, on the other hand, is known to reduce stomata opening and hence, leaf‐level transpiration, which may translate into higher soil moisture and enhanced total runoff. Here, we quantify these opposing effects of global change on the water balance of alpine grassland in a field experiment in the Swiss Alps (2440 m a.s.l.).

Rates of ET and deep seepage (percolation water) of four alpine grassland types (dominated by Agrostis, Nardus, Carex or forbs) were measured using intact monoliths in 51 weighing lysimeters. A part of the monoliths was clipped to simulate sheep grazing during three seasons (2008–2010). Another set was exposed to elevated CO2 (580 ppm) using free‐air CO2 enrichment (FACE) during the 2009 growing season.

Simulated grazing reduced bright day ET by on average −12% across all years, with the most pronounced effects in the high‐stature swards. Correspondingly, the higher biomass and LAI in unclipped grassland lowered the seasonal sum of deep seepage by −13% in a drier summer (2009) and by −5% in a rather wet summer (2010) compared to clipped swards.

CO2 enrichment reduced ET in all grassland types by −3 to −7%, increased δ18O in foliage and enhanced soil moisture, but not deep seepage. Hence, future CO2 slightly counteracts the land use effects at canopy level, however, not in terms of water yield.

Synthesis. Our results indicate that both grazing and elevated CO2 are mitigating the effects of dry spells on alpine vegetation. The net effect of the continuous decline in the land use and of elevated CO2 is negative for catchment water yield and thus, for potential hydroelectric power production. Although these economic ‘costs’ are rather moderate per hectare of alpine grassland, sums are substantial when scaled to the vast areas potentially affected in the Alps. These calculated ‘costs’ attribute economic value to the eco‐hydrological benefits of land care at these high elevations.