bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual field defects after radiosurgery for mesial temporal lobe epilepsy
Authors: Hensley‐Judge Holly , Quigg Mark , Barbaro Nicholas M. , Newman Steven A. , Ward Mariann M. , Chang Edward F. , Broshek Donna K. , Lamborn Kathleen R. , Laxer Kenneth D. , Garcia Paul , Heck Christianne N. , Kondziolka Douglas , Beach Robert , Salanova Vicenta , Goodman Robert
Published: May 2013

Purpose

Gamma knife radiosurgery (RS) may be an alternative to open surgery for mesial temporal lobe epilepsy (MTLE), but morbidities and the anticonvulsant mechanisms of RS are unclear. Examination of visual field defects (VFDs) after RS may provide evidence of the extent of a postoperative fixed lesion. VFDs occur in 52–100% of patients following open surgery for MTLE.

Methods

This multicenter prospective trial of RS enrolled patients with unilateral hippocampal sclerosis and concordant video–electroencephalography (EEG) findings. Patients were randomized to low (20 Gy) or high (24 Gy) doses delivered to the amygdala, hippocampal head, and parahippocampal gyrus. Postoperative perimetry were obtained at 24 months after RS. Visual field defect ratios (VFDRs) were calculated to quantify the degree of VFDs. Results were contrasted with age, RS dose and 50% isodose volume, peak volume of radiation‐induced change at the surgical target, quality of life measurements, and seizure remission.

Key Findings

No patients reported visual changes and no patients had abnormal bedside visual field examinations. Fifteen (62.5%) of 24 patients had postoperative VFDs, all homonymous superior quadrantanopsias. None of the VFDs were consistent with injury to the optic nerve or chiasm. Clinical diagnosis of VFDs correlated significantly with VFDRs (p = 0.0005). Patients with seizure remission had smaller (more severe) VFDRs (p = 0.04). No other variables had significant correlations.

Significance

VFDs appeared after RS in proportions similar to historical comparisons from open surgery for MTLE. The nature of VFDs was consistent with lesions of the optic radiations. The findings support the hypothesis that the mechanism of RS involves some degree of tissue damage and is not confined entirely to functional changes in neuromodulation.
Structural characterization of human histidine triad nucleotide‐binding protein 2, a member of the histidine triad superfamily
Authors: Maize Kimberly M. , Wagner Carston R. , Finzel Barry C.
Published: May 2013

The histidine triad proteins (HITs) constitute a large and ubiquitous superfamily of nucleotide hydrolases. The human histidine triad nucleotide‐binding proteins (hHints) are a distinct class of HITs noted for their acyl‐AMP hydrolase and phosphoramidase activity. The first high‐resolution crystal structures of hHint2 with and without bound AMP are described. The differences between hHint2 and previously known HIT family protein structures are discussed. HIT family enzymes have historically been divided into five classes based on their catalytic specificity: Hint, fragile HIT protein, galactose‐1‐phosphate uridylyltransferase, DcpS and aprataxin. However, although several structures exist for the enzymes in these classes, the endogenous substrates of many of these enzymes have not been identified or biochemically characterized. To better understand the structural relationships of the HIT enzymes, a structure‐based phylogeny was constructed that resulted in the identification of several new putative HIT clades with potential acyl‐AMP hydrolase and phosphoramidase activity.

Database

Atomic coordinates have been deposited in the Protein Data Bank under accession numbers 4INC and 4INI

Structured digital abstract

hHint2 and hHint2 bind by x-ray crystallography (View interaction)
Combined administration of FVIII and rFVIIa improves haemostasis in haemophilia A patients with high‐responding inhibitors – a thrombin generation‐guided pilot study
Authors: Livnat T. , Martinowitz U. , Azar‐Avivi S. , Zivelin A. , Brutman‐Barazani T. , Lubetsky A. , Kenet G.
Published: May 2013

Treatment of haemophilia A patients with inhibitors is challenging, and may require individually tailored regimens. Whereas low titre inhibitor patients may respond to high doses of factor VIII (FVIII), high‐responding inhibitor patients render replacement therapy ineffective and often require application of bypassing agents. Thrombin generation (TG) assays may be used to monitor haemostasis and/or predict patients' response to bypass agents. In this study we defined by TG, the potential contribution of FVIII to recombinant activated factor VII (rFVIIa)‐induced haemostasis in inhibitor plasma. Based upon results, prospectively designed individual regimens of coadministration of rFVIIa and FVIII were applied. Plasma samples from 14 haemophilia patients with inhibitors (including high titre inhibitors) were tested. The response to increasing concentrations of FVIII, rFVIIa or both was assayed by TG. Eight patients, chosen following consent and at physician's discretion, comprised the combined FVIII–rFVIIa therapy clinical study cohort. Combined spiking with FVIII/rFVIIa improved TG induced by rFVIIa alone in all inhibitor plasmas. Combined rFVIIa and FVIII therapy was applied during bleeding or immune tolerance to eight patients, for a total of 393 episodes. Following a single combined dose, 90% haemostasis was documented and neither thrombosis nor any complications evolved. During study period decline of inhibitor levels and bleeding frequency were noted. Pre‐analytical studies enabled us to prospectively tailor individual therapy regimens. We confirmed for the first time that the in vitro advantage of combining FVIII and rFVIIa, indeed accounts for improved haemostasis and may safely be applied to inhibitor patients.
Obesity in haemophilia patients: effect on bleeding frequency, clotting factor concentrate usage, and haemostatic and fibrinolytic parameters
Authors: Tuinenburg A. , Biere‐Rafi S. , Peters M. , Verhamme P. , Peerlinck K. , Kruip M. J. H. A. , Laros‐Van Gorkom B. A. P. , Roest M. , Meijers J. C. M. , Kamphuisen P. W. , Schutgens R. E. G.
Published: May 2013

The prevalence of obesity in patients with haemophilia (PWH) is increasing. We investigated the effect of obesity on bleeding frequency and clotting factor concentrate (CFC) usage in PWH and assessed whether prothrombotic changes observed in obesity differ between controls and PWH. Number of bleeds and CFC usage were compared between obese (N = 51) and non‐obese (N = 46) haemophilia A patients. Markers of haemostasis and fibrinolysis were compared between PWH, and gender‐, age‐ and body mass index (BMI)‐matched non‐haemophilic controls (N = 91). Median number of bleeds/patient‐month was comparable between obese and non‐obese patients with severe haemophilia (P = 0.791). Obese patients with severe haemophilia used 1.4 times more CFC/patient‐month than non‐obese patients (P = 0.036). When adjusting for weight this difference disappeared (P = 0.451). von Willebrand factor plasma concentration (VWF:Ag), factor VIII activity and endogenous thrombin potential were higher in obese than in non‐obese controls. Obesity did not influence these markers in PWH. Plasminogen activator inhibitor type 1 levels were higher in obese vs. non‐obese PWH (P < 0.001), whereas levels were comparable between PWH and controls (P = 0.912). Plasmin‐α2‐antiplasmin complex (PAP) levels appeared to be lower in obese vs. non‐obese subjects, both within controls (P = 0.011) and PWH (P = 0.008). However, in PWH, PAP levels were higher than in controls (P < 0.001). Obesity is associated with an increase in net CFC usage in PWH, but has no effect on bleeding frequency. In addition, obesity attenuates hyperfibrinolysis in PWH. Future research investigating whether obese PWH need CFC treatment dosed on weight or whether a lower dosage would suffice to prevent and treat bleedings is needed.
Desisting from Domestic Abuse: Influences, Patterns and Processes in the Lives of Formerly Abusive Men
Authors: Morran David
Published: May 2013

This article argues that domestic violence perpetrator programmes in the UK have paid insufficient attention to how perpetrators actually desist from abusive behaviour in the long term. It draws on evidence from a 2010 study which investigated how a sample of men accomplished desistance from abusive behaviour. It reveals that even men committed to desistance may require programmes to support them over a period of several years, and confirms that desistance is best understood as a process and not an outcome. The article concludes that these men's experiences underline the need for interventions to be substantially more desistance‐focused than they are at present.
Synthesis of CoFe2O4 Nanoparticles by a Low Temperature Microwave‐Assisted Ball‐Milling Technique
Authors: Chen Ding , Yi Xiang , Chen Zhenhua , Zhang Yingzhe , Chen Biyu , Kang Zhitao
Published: May 2013

Well‐crystallized Cobalt ferrite nanoparticles with mean size of 20 nm and high saturation magnetization (82.9 emu/g) were synthesized at a low temperature (≤100°C) by microwave‐assisted solid–liquid reaction ball‐milling technique without subsequent calcination. CoC2O4·4H2O and Fe powder were used as raw materials and stainless steel or pure iron milling balls with diameter of 1.5 mm were used. As a contrast, solid–liquid reaction ball milling without microwave assistance was also investigated. The results showed that this is a simple, environmentally friendly, and energy‐saving technique for ferrite nanocrystal synthesis.
Homogeneous Precipitation Synthesis and Low‐Voltage Cathodoluminescence of SnO2:Eu3+ Phosphors for Field Emission Displays
Authors: Huang Tongwen , Wang Xiaojun , Zhu Pingping , Li Huili , Feng Tao , Sun Zhuo
Published: May 2013

A reddish‐orange‐emitting SnO2:Eu3+ phosphor for field emission displays (FEDs) was successfully synthesized via a homogeneous precipitation route using urea as a precipitant. The influences of the dopant concentration of Eu3+ and calcination temperature on optical properties were investigated. The low‐voltage field emission properties of the FED device prepared using the synthesized SnO2:Eu3+ phosphors were reported. Under the UV light, SnO2:Eu3+ phosphors display the strong orange–red emission peaked at 587, 591, and 597 nm due to the 5D0→7F1 magnetic dipole transition of Eu3+. The phosphor doped with 1.0 mol% Eu3+ possesses the highest photoluminescent (PL) intensity. Under the low‐voltage excitation of 300 V, the fabricated FED device exhibits the bright orange–red emission, high‐voltage brightness saturation, and high color purity, which has a potential application in low‐voltage full color FEDs.
Finger taps and constipation are closely related to symptoms of overactive bladder in male patients with Parkinson's disease
Authors: Tsujimura Akira , Yamamoto Yoichi , Sakoda Saburo , Okuda Hidenobu , Yamamoto Keisuke , Fukuhara Shinichiro , Yoshioka Iwao , Kiuchi Hiroshi , Takao Tetsuya , Miyagawa Yasushi , Nonomura Norio
Published: May 2013

Objectives

To assess which motor and non‐motor symptoms are closely related to overactive bladder severity in male patients with Parkinson's disease.

Methods

A total of 160 male patients (mean age 71.4 ± 8.2 years) diagnosed with Parkinson's disease were included in the present study at Osaka University and affiliated hospitals. The severity of Parkinson's disease was classified as stage 3, 4 or 5 based on the Hoehn and Yahr staging system. Disease duration was 8.9 ± 5.1 years. Age, seven items from the Unified Parkinson's Disease Rating Scale motor section part III and three non‐motor symptoms were assessed by multivariate analysis for their impact on the overactive bladder symptom score, a specific questionnaire for overactive bladder.

Results

Overactive bladder symptom score was significantly higher in the group with severe motor symptoms related to finger taps and gait than in the group with mild motor symptoms related to these two factors. Furthermore, overactive bladder symptom score of patients with erectile dysfunction and constipation was significantly higher than that in patients without these symptoms. Multivariate analysis identified only finger taps and constipation as factors independently associated with overactive bladder symptom score.

Conclusions

Although a study on a larger scale is required to further assess the association of Parkinson's disease symptoms with overactive bladder symptom score, information on finger taps and severity of constipation should be obtained when assessing urological patients with Parkinson's disease.
Natural killer cell‐mediated contact sensitivity develops rapidly and depends on interferon‐α, interferon‐γ and interleukin‐12
Authors: Majewska‐Szczepanik Monika , Paust Silke , von Andrian Ulrich H. , Askenase Philip W. , Szczepanik Marian
Published: May 2013

Natural killer (NK) cell‐mediated contact sensitivity was recently described in mice. Here, we confirm NK cell‐mediated contact sensitivity (CS) in SCID and RAG1−/− mice but not in SCIDbeige mice, which have non‐functional NK cells that lack NK cell granules. NK cell‐mediated CS was transferred by liver mononuclear cells and the DX5+ fraction of liver cells, confirming that NK cells mediate CS in the absence of T and B cells. Participation of NKT cells and B‐1 cells was ruled out using Jα18−/− and JH−/− mice, respectively. Remarkably, NK cell‐mediated CS was observed just 1 hr after immunization and was detectable as early as 30 min after challenge. Further, we examined cytokine requirements for NK cell‐mediated CS, and found that liver mononuclear cells from interleukin‐12−/−, interferon‐γ−/− and interferon‐α receptor−/− donors fail to transfer NK cell‐mediated CS to naive hosts. Our studies clearly show that dinitrofluorobenzene sensitized NK cells mediate very rapid, antigen‐specific cell‐mediated immunity, with features of both innate and acquired immune responses.
Is climate a stronger driver of tree growth than disturbance? A comment on Toledoet al.(2011)
Authors: Ferry Bruno , Bontemps Jean‐Daniel , Blanc Lilian , Baraloto Christopher
Published: May 2013

1. A recent article published byToledoet al.(2011b)investigates the effects of spatial variations in climate and soil, and of logging disturbance, on tree and forest growth in Bolivia. It concludes that climate is the strongest driver of tree and forest growth and that climate change may therefore have large consequences for forest productivity and carbon sequestration. However, serious methodological and conceptual discrepancies have been found that challenge these conclusions.

2. Because of an errant coding of ‘time after logging’ in the regression analysis, and because floristic changes induced by logging could not be incorporated into the analysis, the effect of logging on the average diameter growth is likely to have been strongly underestimated.

3. Basal area growth was improperly calculated as basal area change, and it displayed surprisingly high values, even among unlogged plots. We hypothesize that either these plots may be actually located in secondary forests recovering from past logging, or measurement biases may have hampered the data set.

4. Regardless of climate–growth relationships established across these plots, any inference concerning the potential effects of climate change on forest growth would require a specific quantitative assessment.

5. Synthesis. It is critical to re‐assess the relative weight of climate and logging disturbance as driving factors of tree and forest growth, and to find an explanation for the very high basal area increment reported among the unlogged plots. We provide specific recommendations for further analyses of this and similar data sets.
Biological Flora of the British Isles: Dryopteris carthusiana, D. dilatata and D. expansa
Authors: Rünk Kai , Zobel Martin , Zobel Kristjan
Published: May 2013

1. This account presents information on all aspects of the biology of Dryopteris carthusiana (Vill.) H. P. Fuchs, D. dilatata (Hoffm.) A. Gray, and D. expansa (C. Presl) Fraser‐Jenk. & Jermy that are relevant to an understanding of their ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, reproductive characteristics, herbivores, history, and conservation.

2. All three species are native deciduous ferns that are morphologically similar and genetically interrelated. Dryopteris dilatata, one of the commonest ferns in the British Isles, is found in many different habitats, but is above all a woodland species. Dryopteris carthusiana is less widely distributed, being mostly a species of wetlands and wet woodlands. Dryopteris expansa is the least common, mostly found in mountains, but also in wet woodlands at lower altitudes.

3. Dryopteris dilatata is mainly a species of semi‐shade, and in the British Isles is considered to be the most shade‐tolerant of the three. Dryopteris carthusiana occurs in a wide range of habitats, from exposed, well‐illuminated to moderately shaded ones. Dryopteris expansa mainly grows in better illuminated habitats, often in the shade of sparse canopies or rocks. D. expansa is thus the most light‐demanding species of the three.

4. The response to competition from neighbouring herbs has been shown to differ among the three species; D. expansa is clearly more vulnerable to competition than D. carthusiana and D. dilatata.

5. Dryopteris dilatata and D. carthusiana are both tetraploid, whereas D. expansa is diploid. Natural hybrids among all three species in the British Isles, as well as hybrids of D. carthusiana with D. filix‐mas and D. cristata. The hybrid D. carthusiana × D. dilatata = D. × deweveri is the most common. The hybrids D. carthusiana × D. expansa = D. × sarvelae and D. cristata ×D. carthusiana = D. × uliginosa are extremely rare and at high risk of extinction.

6. Although not currently threatened, the distribution of all three species may be susceptible to continued habitat loss arising from changes in land use, management for control of Bracken and predicted climate change.
Resilience to chronic defoliation in a dioecious understorey tropical rain forest palm
Authors: Lopez‐Toledo Leonel , Anten Niels P. R. , Endress Bryan A. , Ackerly David D. , Martínez‐Ramos Miguel
Published: May 2013

1. Perennial plants often endure chronic loss of leaf area due to recurrent physical damage, herbivory and, for species used as non‐timber forest products, due to leaf harvesting. However, little is known about functional and demographic resilience (extent and speed of recovery) of plants subjected to varying levels of chronic defoliation.

2. We used a dioecious, understorey palm (Chamaedorea elegans) to evaluate temporal trajectories and rates of recovery of leaf functional traits and vital rates (survival, growth and reproduction) after being subjected to experimental chronic defoliation regimes.

3. Pristine populations of mature C. elegans, categorized by gender (male and female), were subjected to five defoliation levels (0%, 33%, 50%, 66% or 100% of newly produced leaves) every 6 months over a period of 3 years (1997–2000). To evaluate recovery from defoliation, surviving palms were monitored for 3 years after the cessation of the defoliation treatment (2000–2003). We recorded leaf functional traits (leaf persistence, leaf production rate, leaf size and leaf area) and annual rates of mortality, growth and reproduction.

4. Cumulative effects of chronic defoliation concomitantly reduced leaf traits, survival, growth and reproduction, and this effect was stronger in female than in male palms, independent of plant size. Recovery from defoliation was faster in males than in females, but proceeded gradually overall. Survival increased first, followed by growth, while reproductive traits showed the slowest recovery rate. Recovery was independent of plant size. Notably, 3 years after defoliation treatment, the standing leaf area and probability of reproduction had not recovered to pre‐defoliation levels. Additionally, we found that the occurrence of a severe drought in the first year (2000) after defoliation ceased led to decreased survival, growth and reproduction and the ability of plants to recover from defoliation.

5. Synthesis. Chronic defoliation reduces fitness components of C. elegans palms differentially between genders. Recovery is gradual and is slower and less complete in females compared with males. The lower level of resilience to chronic defoliation shown by female plants may have profound consequences for the dynamics and genetic variability of populations of tropical understorey plants undergoing prolonged defoliation. Such effects may be aggravated by severe drought episodes that are expected to increase in frequency according to global climate change predictions.
Multiple competitive mechanisms underlie the effects of a strong invader on early‐ to late‐seral tree seedlings
Authors: Urgenson Lauren S. , Reichard Sarah H. , Halpern Charles B.
Published: May 2013

1. Certain non‐native invaders reduce the species diversity and alter the structure of natural communities by displacing native species with differing life histories, successional roles or resource requirements. Few studies have tested the potential for these ‘strong invaders’ to exert multiple mechanisms of control on natives that differ in these traits.

2. We assessed the mechanisms by which bohemian knotweed (Polygonum × bohemicum) regulates seedling growth and survival among early‐, mid‐ and late‐seral tree species in a riparian forest ecosystem in western North America. We used general linear mixed models to compare seedling performance (survival, height and diameter growth, biomass allocation and ectomycorrhizal colonization of root systems) over two growing seasons in paired experimental plots from which knotweed was either removed or retained (controls). Seedling performance was assessed relative to the effects of knotweed on light and soil resources and the traits of the native species.

3. Results from paired t‐tests suggest that knotweed had a significant effect on light availability (>85% reduction), but small, mostly non‐significant effects on measured soil properties. Knotweed imposed strong controls on growth and survival of all three tree species. The apparent mechanisms of interaction varied in a manner consistent with species’ ecophysiologies. Reduced survival of early‐ and mid‐seral species was correlated with light limitation beneath knotweed (≤ 7% of ambient levels): light transmittance was significantly higher (79%) above surviving seedlings. Knotweed also exerted strong controls on the late‐seral species, reducing survival by 24% and height and diameter growth by 91–122% and 37–55%. These effects were not correlated with reductions in light. Instead, in the presence of knotweed, ectomycorrhizal colonization was significantly reduced (64%) and root/shoot ratio was significantly increased, suggesting a disruption of soil mutualisms.

4. Synthesis. We demonstrate that strong invaders can displace co‐occurring native species through multiple mechanisms that are consistent with the functional traits of native species. To our knowledge, this is the first study to relate community‐level impacts of an invader to the combined effects of resource exploitation and interference of below‐ground mutualisms. Where invaders have the ability to displace early‐ to late‐seral dominants, the consequences for community structure and ecosystem functioning can be profound.
Species and organ specificity of fungal endophytes in herbaceous grassland plants
Authors: Wearn James A. , Sutton Brian C. , Morley Neil J. , Gange Alan C.
Published: May 2013

1. aFoliar endophytic fungi in herbaceous plants are known to be diverse, yet studies characterizing the fungal communities in roots and shoots of plants across time are absent. These fungi are supposedly ubiquitous in nature, infecting plants through airborne spores. As many foliar endophytes can also exist in soil, we hypothesized that there would be a strong similarity between root and shoot endophytes in any given plant species and that differences between plant species would be greater than those between organs within a species.

2. Leaf and root fungal endophyte communities were assessed in field‐collected plants of three co‐occurring grassland forbs (Cirsium arvense, Plantago lanceolata and Rumex acetosa) in two contrasting seasons (winter and summer). The former two species are mycorrhizal, whilst the latter species is not so.

3. The highest fungal species richness was recorded from P. lanceolata with R. acetosa hosting the least endophyte diversity. Endophyte communities were more diverse in root than leaf tissues and in summer than in winter. Similarity of endophyte communities between different host plant species and organs within an individual host was very low. Negative correlations were found between mycorrhizal colonization and endophyte presence in the roots of C. arvense and P. lanceolata, suggesting some degree of antagonism or competition between the fungi. Consistent positive associations were found between the number of endophyte species in roots and shoots of plants.

4. Synthesis. In contrast to previous studies, the results show that many endophytes do not occur ubiquitously, but instead exhibit both plant and tissue specificity. There is a strong seasonal change in endophyte communities, but the differences between roots and shoots at any one time can be just as large. This dissimilarity suggests a lack of systemic growth by the fungi from one tissue to another. Mycorrhizas may interact negatively with other root endophytes, indicating that the latter should not be ignored in future mycorrhizal studies. We should begin to think of individual plants as ecosystems of interacting microbes, whose community is structured by plant genetics and environmental conditions, coupled with interactions between the microbes themselves.
Spatial variation in below‐ground seed germination and divergent mycorrhizal associations correlate with spatial segregation of three co‐occurring orchid species
Authors: Jacquemyn Hans , Brys Rein , Lievens Bart , Wiegand Thorsten
Published: May 2013

1. Understanding the many factors that affect community composition and coexistence of species in natural environments is one of the central goals in ecology. As germination and establishment of seedlings in orchids are crucially dependent on mycorrhizal availability, the diversity and spatial distribution of orchid mycorrhizal fungi are likely factors that contribute to orchid coexistence.

2. In this study, we combined molecular identification techniques with seed germination experiments and spatial point pattern analyses to investigate to what extent differences in mycorrhizal association patterns affected spatial variation in seed germination and the above‐ground distribution of three co‐occurring terrestrial orchid species (Anacamptis morio, Gymnadenia conopsea and Orchis mascula).

3. The three species associated with a different set of mycorrhizal fungi, except A. morio and G. conopsea, which shared one fungal associate. The number of fungal lineages detected associating with each species also differed between species, being highest in G. conopsea, which associated with five lineages, and restricted to a single lineage in O. mascula.

4. Seed germination experiments showed that below‐ground seed germination was restricted to locations where orchid individuals were most abundant, and quickly declined with increasing distance from the nearest above‐ground congener. Spatial point pattern analyses indicated significant fine‐scale spatial clustering that was highest in O. mascula and lowest in G. conopsea. Moreover, the spatial distributions of the three species were independent from each other, except for A. morio and G. conopsea.

5. Synthesis. Our results support previous findings that co‐occurring orchid species tend to use different mycorrhizal partners. Although the possibility that variation in local environmental conditions affected seed germination could not be completely ruled out, our results suggest that the presence of specific mycorrhizal fungi contributed, at least partly, to the spatial distribution and coexistence of the investigated orchid species.
Snail grazing facilitates growth of two morphologically similar bloom‐forming Ulva species through different mechanisms
Authors: Guidone Michele , Thornber Carol S. , Vincent Emily
Published: May 2013

Herbivores can facilitate macrophyte growth through stimulation of overcompensation pathways, removal of neighbouring or fouling competitors or increasing nutrient availability via nitrogenous waste inputs.

We examined the facilitative relationship between the mud snail
Ilyanassa obsoleta and two morphologically similar bloom‐forming
Ulva species,
Ulva compressa and
Ulva rigida. Through mesocosm experiments, we determined the occurrence and underlying mechanisms responsible for facilitating
Ulva growth. In situ snail enclosure experiments determined the occurrence of this facilitative pathway under natural conditions.

We found that both
U. compressa and
U. rigida are facilitated by
I. obsoleta, but despite their morphological similarity, the primary facilitative mechanism differed for each species.
Ulva compressa experienced increased growth via snail nitrogenous waste inputs, while
U. rigida was facilitated by the removal of fouling microalgae. These results suggest that physiological differences exist between these two species, potentially sustaining their coexistence within blooms.

Ground tissue assays showed
I. obsoleta preference for microalgal foulers in whole‐tissue assays was driven by
Ulva blade morphology rather than chemical or nutritive properties. This indicates that the underlying mechanism for
I. obsoleta's facilitation via grazing is an inability of the snail's radula to effectively puncture
Ulva blades, confining their grazing activities to fouling organisms on the blade surface.

In contrast to our mesocosm results, in situ experiments failed to find a positive impact of mud snail presence on
Ulva blade growth. However,
Ulva blades within these experiments were located at a highly eutrophic site and isolated from potential competitors. Consequently, this may have created an environment where
I. obsoleta facilitation was not required for maximum
Ulva growth.

Synthesis. We demonstrated two mechanisms by which top‐down forces can facilitate macroalgal growth: herbivore nitrogenous waste inputs and removal of microalgal fouling organisms. This facilitation may occur within the large mats of macroalgae that form during bloom events, exacerbating bloom conditions.
Pollination mode predicts phenological response to climate change in terrestrial orchids: a case study from central Europe
Authors: Molnár Attila , Tökölyi Jácint , Végvári Zsolt , Sramkó Gábor , Sulyok József , Barta Zoltán
Published: May 2013

Herbarium collections contain long‐term data for a wide range of taxa and provide unique opportunities to evaluate the importance of life‐history components in driving species‐specific responses to climate change. In this paper, we analyse the relationships between change in flowering dates and life‐history traits within a phylogenetic framework. The study is based on an extensive data set of herbarium specimens of orchids collected in Hungary between 1837 and 2009, supplemented by recent field observations (1980–2011).

Of the 39 taxa investigated, 31 (79%) showed apparent advancement in mean flowering time. Among these, advancement was statistically significant in nine taxa. The rest (eight taxa) showed non‐significant delays in flowering. Averaging across all taxa, flowering time advanced by 3 days (3.8% of flowering period) during the last 50 years compared with the period before 1960. In taxa showing significant advancement, flowering times advanced by 7.7 days (8.6% of the flowering period). The most extreme advancement was 13.9 days.

Multivariate models were used to evaluate ways in which life history may affect phenological responses to climate change. Pollination mode (i.e. deceptive vs. rewarding vs. autogamous), life span (i.e. short‐lived vs. long‐lived), biogeographical distribution type (i.e. Mediterranean vs. non‐Mediterranean) and flowering time (i.e. mean date of blooming) emerged as important factors that influence changes in flowering through time. Phylogenetic relatedness did not predict phenological response. The strongest response was observed in orchids that flower relatively early in spring, exhibit an autogamous or deceptive pollination mechanism, have a long life span and possess a Mediterranean centre of distribution.

Synthesis. Our investigation demonstrates that the majority of Hungarian orchids have shifted their yearly mean flowering to earlier dates during the past 50 years. Certain life‐history traits, but not phylogenetic relatedness, were found to be important in predicting climatic responsiveness in European terrestrial orchids.
Can floral traits predict an invasive plant's impact on native plant–pollinator communities?
Authors: Gibson Michelle R. , Richardson David M. , Pauw Anton
Published: May 2013

The possession of certain floral traits can determine which insects visit a plant species. If two species possess similar floral traits that determine shared flower visitors, floral traits can be said to mediate plant–plant interactions. Such indirect interactions are important for understanding fundamental relationships of plant communities, such as competition and facilitation but thus far have only been tested within a native community context.

We test whether floral‐trait similarity can be used to predict interactions between an invasive plant and co‐occurring native species in South Africa's Cape Floristic Region. We surveyed flower visitation at invaded and uninvaded plots across four sites and correlated floral‐trait similarity between invasive and native species with both invasion impact on native flower visitation and flower visitor overlap of natives and the invasive species.

Similarity of all traits (categorical and continuous) and categorical traits alone explained invasion impact (flower visitor overlap) between the native and invasive species. The majority of flower visitor overlap was attributed to the native honeybee Apis mellifera subsp. capensis.

This study is the first to show that floral traits can be used to predict novel plant–plant interactions, even amongst ecologically generalized flower visitors and plants and to predict potential impacts of an invasive species on native flowering communities. However, floral traits were not useful for predicting changes in visitation to plant species.

Synthesis. Results advance our understanding of the role of plant traits in ecological communities and reveal that they are important in mediating not only plant–pollinator interactions but also plant–plant interactions. Our findings also shed light on invasive–native plant interactions via pollinators and have the potential to predict certain invasion impacts.
Size is not everything for desiccation‐sensitive seeds
Authors: Hill James P. , Edwards Will , Franks Peter J.
Published: May 2013

Almost 50% of all seed plants produce desiccation‐sensitive seeds. For these species, pre‐germination survival may be equally as important a basis of seed trait selection as seedling establishment. However, few studies have explored correlations among seed traits considered influential in the retention of viability prior to germination.

We examine four physiological traits: critical water content (Wr50), the mean seed water content when a cohort of seeds reaches 50% mortality, desiccation rate (t0.368), the time taken for each seed to reach a relative water content of 36.8%, mean time to germination (TG), the time taken for 50% of seeds within a cohort to germinate; and specific relative water content (WM), the proportion of available water to dry seed mass; two morphological traits: seed size (MD), dry seed mass and seed coat ratio (SCR), the proportional mass between the seed coat and dry seed mass; and one phenological variable: mean monthly rainfall at mean time of seed dispersal (RM) in 16 plant species that produce desiccation‐sensitive seeds from a seasonal tropical forest in Cairns, Queensland.

We first test for relationships among species, and then assess relationships between species in trait space via principal component analysis (PCA). Regression analysis revealed a significant negative relationship between RM and SCR, so that species that had dispersal periods at times of high moisture availability invested proportionally less into seed coats. No other pairwise trait combinations were significantly related. PCA revealed two axes of trait space. The first axis was associated with the traits SCR, TG, t0.368, RM and WM, and explained 44.1% of the variation between species. There were strong positive loadings for SCR, TG and t0.368, and strong negative loadings for RM and WM. Traits with strong loadings on the second axis (total variance 21%) were MD and Wr50 and WM. There were strong positive loadings for Wr50 and strong negative loadings for MD and WM.

Synthesis. Our findings reveal an axis of trait variability among desiccation‐sensitive seeds that is orthogonal to size. These traits might be important in surviving pre‐germination environmental conditions, independent of the advantages and/or disadvantages that size has been shown to confer on seed survival and seedling establishment. The implication of this finding is that seed size alone may not account for pre‐germination viability in desiccation‐sensitive seeds and may be inadequate to predict long‐term persistence of these species if climate changes occur on the scale predicted.
Variation and constraints of local adaptation of a long‐lived plant, its pollinators and specialist herbivores
Authors: Kalske Aino , Muola Anne , Laukkanen Liisa , Mutikainen Pia , Leimu Roosa
Published: May 2013

Due to geographically variable species interactions, plants may become locally adapted to their sympatric herbivores and pollinators. However, adaptation to the abiotic environment may significantly affect plant interactions with herbivores and pollinators. Local adaptation to the abiotic environment may constrain local adaptation to herbivores and pollinators under contrasting selection pressures, resulting in trade‐offs in local adaptation.

We studied local adaptation of a perennial herb, Vincetoxicum hirundinaria, in a reciprocal transplant experiment among four populations and measured plant fitness, pollination success and resistance to two specialist herbivores. We also estimated local adaptation of these two herbivores and generalist pollinators to their sympatric plant populations. Local adaptation was compared with within‐population genetic variation, genetic and geographical divergence, and with divergence in terms of population size, environmental conditions and plant secondary chemistry. We further compared local adaptation to the environment, to local adaptation to herbivores and pollinators to detect possible trade‐offs in local adaptation.

The existence and degree of local adaptation varied among the plant populations. Plants from two populations were locally adapted to their sympatric leaf herbivores and plants from two populations were locally adapted to their abiotic environment. Herbivores from one population were locally adapted to their sympatric plant population. Local adaptation of V. hirundinaria to the seed predator increased with increasing among‐population divergence in precipitation and temperature. Local adaptation to the seed predator and the environment increased with increasing population genetic variation. Local adaptation of V. hirundinaria in fitness and in herbivore resistance also correlated positively, suggesting lack of trade‐offs in local adaptation.

Synthesis. These results demonstrate that species interactions can lead to a mosaic of locally adapted plant, herbivore and pollinator populations. In addition to natural enemies, genetic variation, the abiotic environment and mutualistic interactions contribute to the evolution of local adaptation in long‐lived plants. These results provide new insights into the patterns and causes of variation in local adaptation and are among the first to demonstrate that conflicting selection pressures within a population do not constrain local adaptation in multiple traits.
Defoliation and gender effects on fitness components in three congeneric and sympatric understorey palms
Authors: Hernández‐Barrios Juan C. , Anten Niels P. R. , Ackerly David D. , Martínez‐Ramos Miguel
Published: May 2013

Rain forest understorey perennial plants can be frequently exposed to leaf area losses induced by herbivory or physical damage from falling canopy debris. In dioecious species, tolerance to defoliation may differ between genders (e.g. females may suffer more than males), but this topic has so far received little attention.

Here, we quantified gender‐dependent effects of increased levels (0–100%) of sustained defoliation (applied bi‐annually for 2 years) on vital rates in three economically important dioecious understorey palm species in the genus Chamaedorea (C. elegans, C. ernesti‐augustii and C. oblongata). We also quantified gender differences in functional and life‐history traits and assessed the direct reproductive costs in terms of biomass allocation to reproduction.

In the three species, non‐defoliated (control) females were smaller and had three to seven times higher reproductive allocation than males.

Defoliation did not affect survivorship in any of the three species, except in the 100% defoliation treatment. Stem growth (RGR) and especially reproduction (probability of reproduction and reproductive output) were negatively affected by defoliation. Females of C. ernesti‐augustii suffered higher mortality than males at 100% defoliation, but this was not the case for the other two species. Also, only in C. ernesti‐augustii females exhibited lower RGR than males. In all species, the probability of reproduction did not differ between genders. The reproductive output (production rate of inflorescences) differed among genders only in C. ernesti‐augustii, where males were more productive than females.

Interestingly, in most cases, defoliation effects on vital rates did not differ significantly between males and females, indicating that tolerance to defoliation was similar between genders. Such results were independent of plant size (stem length).

Synthesis. Our results do not support the prevailing theory that the greater reproductive costs of females will lead to reduced tolerance to stresses such as defoliation. The implications of these results and their importance for designing sustainable leaf harvesting regimes are discussed.
Extirpation‐resistant species do not always compensate for the decline in ecosystem processes associated with biodiversity loss
Authors: Davies Thomas W. , Jenkins Stuart R. , Kingham Rachel , Hawkins Stephen J. , Hiddink Jan G.
Published: May 2013

Accelerating rates of biodiversity loss may result in a rapid decline in important ecosystem processes such as carbon capture. Whether extirpation‐resistant species compensate for the decline in ecosystem processes associated with the loss of extirpation‐prone species is poorly understood.

We apply a novel approach to answer this question using an assemblage of salt marsh plants. First, manipulations were performed to simulate a realistic sequence of species loss, based on observed sensitivity to disturbance. Then, changes in biomass and primary production of extirpation‐resistant species were monitored over three consecutive growing seasons.

Extirpation‐resistant species did not compensate for the loss of either biomass or primary production associated with the removal of extirpation‐prone species.

Factors that determine the potential for compensation within ecosystems are discussed. These include resource‐regulated compensation rates, the level of functional redundancy within an assemblage and the extirpation resistance of species which possess good compensation traits.

Synthesis. These results suggest that we cannot assume extirpation‐resistant species will compensate for the decline in ecosystem processes associated with biodiversity loss across all ecosystems. Understanding those factors that influence the ability of ecosystems to compensate for declines in ecosystem processes associated with biodiversity loss constitutes a significant challenge.
Predicting invasiveness and range size in wetland plants using biological traits: a multivariate experimental approach
Authors: Hovick Stephen M. , Peterson Chris J. , Carson Walter P.
Published: May 2013

Predicting invasion potential across a wide range of plant species using only their biological traits is often challenging. We present a novel approach, aligning species along a multivariate axis of putative invasiveness traits. The traits were quantified in a common garden in which we manipulated two critical variables thought to strongly influence invasiveness: herbivory and resource availability.

We used principal component analysis (PCA) to characterize 20 species based on seven key traits (percentage germination, specific leaf area, seed mass, above‐ground biomass, below‐ground biomass, response to fertilization and response to herbivory). We then assessed whether the linear combination of traits identified by axis 1 of the PCA could predict invasiveness.

Axis 1 of the trait‐based PCA explained nearly 40% of variation in two literature‐based invasiveness scores; thus, we considered it to be useful as a trait‐based invasiveness index. Literature‐based invasiveness was greatest in large species (both above‐ground and below‐ground) with high percentage germination, small positive responses to fertilization and small negative responses to herbivory.

Contrary to expectations from the enemy release hypothesis, species that were native to our region and highly invasive elsewhere were associated with only weak responses to insect herbivory. This suggests that invasion potential may be highest in species that are insensitive to herbivore pressure, rather than species benefitting the most from enemy release.

Native range size is often an effective predictor of invasiveness, although the underlying mechanisms are unclear; we therefore compared the predictive ability of range size versus biological traits. Our trait‐based index was a better predictor of invasiveness than range size, while also explaining nearly 20% of the variation in longitudinal range size.

Synthesis. We present a novel method for using traits to quantify invasiveness that appears to have broad predictive utility. Our results explicitly link biological traits to range size and global invasiveness, perhaps reflecting a general ecological strategy in plants. Following additional testing, this simple method could be utilized in a pre‐introduction screening protocol, and we provide practical recommendations for doing so.