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Questions: Restoring diversity in temperate grasslands requires eliminating invaders and recovering different native phenological groups. Clipping and seed addition promote native grass recovery, but these effects could depend on the phenological overlap between invaders and native species. We evaluated the importance of the interaction between two types of clipping, species phenology and sowing to restore temperate grasslands invaded by the cool‐season forage species Festuca arundinacea (tall fescue). Location: Flooding Pampa grassland (Buenos Aires, Argentina). Methods: We applied selective and non‐selective clipping on tall fescue during the peak growing season, combined with the sowing of native cool‐ and warm‐season grasses. Plant species cover was estimated visually for 3 years; species were categorized by functional groups. Moreover, through emergence trials, we evaluated whether the soil seed bank had been impoverished by invasion. Results: Regardless of selectivity, clipping decreased tall fescue cover by 12%/year, which reduced microsite limitation. Consequently, total native richness increased by 5 spp./year and cover increased from 3% to 50% by the last experimental year, independent of clipping type. Moreover, native warm‐season grasses, the group with the least phenological overlap with invaders, increased by nearly 25% in cover and by 5 spp./m2 with clipping and independently of sowing. Contrarily, native cool‐season grasses, with more phenological overlap with invaders, increased 5% with propagule addition. Furthermore, the seed bank was enriched with tall fescue and depleted of cool‐season grasses. Conclusions: Our results reveal that overcoming microsite limitation is a necessary condition to restore plant diversity in grassland invaded by tall fescue. Nevertheless, seed limitation and phenological overlap may be particularly important to restore the diversity of some native functional groups of plants. Considering the phenology of species can help to identify either clipping targets or phenological groups to be sown when restoring native diversity. [ABSTRACT FROM AUTHOR]

Mammalian cells, particularly Chinese hamster ovary cells, are the dominant system for the production of protein‐based biotherapeutics, however, product degradation, particularly of Fc‐fusion proteins, is sometimes observed that impacts the quality of the protein generated. Here, we identify the site of fragmentation of a model immunoglobulin G1 Fc‐fusion protein, show that the observed clipping and aggregation are decreased by reduced temperature culturing, that the fragmentation/clipping is intracellular, and that reduced clipping at a lower temperature (<37°C) relates to mesenger RNA (mRNA) translation elongation. We subsequently show that reduced fragmentation can be achieved at 37°C by addition of chemical reagents that slow translation elongation. We then modified mRNA translation elongation speeds by designing different transcript sequences for the Fc‐fusion protein based on alternative codon usage and improved the product yield at 37°C, and the ratio of intact to a fragmented product. Our data suggest that rapid elongation results in misfolding that decreases product fidelity, generating a region susceptible to degradation/proteolysis, whilst the slowing of mRNA translation improves the folding, reducing susceptibility to fragmentation. Manipulation of mRNA translation and/or the target Fc‐fusion transcript is, therefore, an approach that can be applied to potentially reduce fragmentation of clipping‐prone Fc‐fusion proteins. [ABSTRACT FROM AUTHOR]

Grassland ecosystems provide essential services to society. To maintain ecosystem functions and services of grasslands under changing environments, it is critical to understand how grasslands respond and feedback to climate change. Here, we present results from a long‐term (16 years) warming and clipping (to mimic hay harvesting or grazing) experiment conducted in a grassland ecosystem dominated by C4 grasses in the Great Plains, USA. We analyzed responses of net primary production (NPP), aboveground NPP (ANPP), and belowground NPP (BNPP) to the expanded ranges of climate conditions observed in the experiment. NPP, ANPP, and BNPP all responded to the climatic variables nonlinearly, with higher degrees of nonlinearity for BNPP than that for ANPP. BNPP peaked at the optimum air temperature of 17.5–18.5°C while ANPP peaked at the optimum air temperature of 18.5–20.0°C. The optimum air temperatures for both ANPP and BNPP were higher than mean annual temperature (16.3°C) at the site. The optimum precipitation for BNPP was intermediate levels (775–1250 mm) while ANPP was maximized in wetter conditions (1250–1605 mm) compared with BNPP. Clipping significantly reduced ANPP and shifted the optimum conditions for BNPP to warmer and wetter conditions. In summary, C4‐grass dominant ecosystems have the potential to increase NPP in future warmer and wetter conditions, and clipping may amplify this positive effect in this grassland ecosystem. [ABSTRACT FROM AUTHOR]

Negative effects of long-term overgrazing have been seriously, grasslands temporal stability is an important ecological concern we need to research. Here, we performed a 12-year-long (2007-2018) two-factor controlled experiment on Kobresia humilis meadow on the Tibetan Plateau. The manipulations included three clipping levels (no clipping, NC; moderate clipping, MC; heavy clipping, HC) and two fertilization levels (no fertilization, NF; fertilization, F). Our results revealed that the two clipping manipulations significantly increased the temporal stability of alpine meadow communities, whose significant increase was more pronounced under the MC than HC treatment. Species asynchrony had a significant positive correlation with species abundance along with compound community gradient. Moreover, asynchrony effects, portfolio effects, and facilitation interactions were all present in the communities under the six types of experimental treatment combinations. Additionally, a selection effect was detected in the compound communities, demonstrating characteristics that are common to different mechanisms. There were no significant differences in the effects of these mechanisms on community temporal stability between the NC-NF and MC-NF interactive communities. The portfolio effects predominated when clipping intensity was moderate under both fertilization and nonfertilization conditions. By contrast, in the compound communities, the selection effect predominated. In summary, we conclude that in meadow communities that undergo clipping and fertilization disturbances, facilitation interactions and weak interactions make a greater contribution toward maintaining their temporal stability. [ABSTRACT FROM AUTHOR]

Summary: Current research on zero‐tail discrete Fourier transform spread OFDM, an add on to conventional discrete Fourier transform DFT‐OFDM modulation without cyclic prefix (CP). Its low power tail is configured for coping up with channel's delay spread. Advantageous feature of ZT DFT‐S‐OFDM has drawn researchers for deploying it as a potential waveform candidate to fifth generation (5G). However, the intrinsic shortcoming of high peak to average power ratio (PAPR) should be alleviated. In order to improve that work, we propose a hybrid PAPR scheme that implements optimized partial transmit sequence (PTS) with tone reservation (TR) with clipping technique. Its earlier work stresses for reducing PTS scheme's computational complexity with enhanced version of monarch butterfly optimization (MBO) for PAPR reduction in ZT DFT‐S‐OFDM system. The proposed model reduced the correlation among the candidate signals. In this paper, we further reduce PAPR by deploying TR clipping pair, which reduces the influence of clipping noise and decreases ZT DFT‐S‐OFDM signal's PAPR at same time. The proposed hybrid technique produces excellent PAPR reduction while improving receiver sensitivity and effective throughout. The performance comparison is done using the parameters like PAPR and BER to confirm that this introduced design exceeds current waveforms designs with more economical design structure. [ABSTRACT FROM AUTHOR]

Summary: In this article, an exponential companding (EC) scheme, which can reduce PAPR without raising the average output power level, is proposed for universal filtered multi carrier (UFMC) signals. However, EC scheme degrades the BER performance. Therefore, an optimal nonlinear companding transform named as "modified exponential companding" (MEC), which can use two companding levels based on a threshold value, is proposed. The proposed MEC scheme shows enhanced PAPR and BER performances than EC scheme. Moreover, the MEC provides more design flexibility and freedom with an unchanged average output power level. Furthermore, a hybrid scheme is also proposed to improve PAPR performance, where clipping operation is employed on MEC signal based on an appropriate clipping threshold. Simulation results illustrate that proposed MEC scheme offers improved system performance with a net gain of 7.22 dB than conventional EC and μ‐law techniques. Besides, the proposed hybrid scheme with clipping ratio 1.3 proffers enhanced PAPR reduction of 8.85 dB and improved net gain of 7.95 dB. Also, the proposed EC, MEC, and hybrid schemes can provide lesser spectrum side‐lobe levels than μ‐law. Finally, the UFMC system with the proposed hybrid scheme is verified by employing wireless open‐access research platform (WARP) as hardware over real‐time channel. [ABSTRACT FROM AUTHOR]

Shifts in dominance and species reordering can occur in response to global change. However, it is not clear how altered precipitation and disturbance regimes interact to affect species composition and dominance.We explored community‐level diversity and compositional similarity responses, both across and within years, to a manipulated precipitation gradient and annual clipping in a mixed‐grass prairie in Oklahoma, USA. We imposed seven precipitation treatments (five water exclusion levels [−20%, −40%, −60%, −80%, and −100%], water addition [+50%], and control [0% change in precipitation]) year‐round from 2016 to 2018 using fixed interception shelters. These treatments were crossed with annual clipping to mimic hay harvest.We found that community‐level responses were influenced by precipitation across time. For instance, plant evenness was enhanced by extreme drought treatments, while plant richness was marginally promoted under increased precipitation.Clipping promoted species gain resulting in greater richness within each experimental year. Across years, clipping effects further reduced the precipitation effects on community‐level responses (richness and evenness) at both extreme drought and added precipitation treatments.Synthesis: Our results highlight the importance of studying interactive drivers of change both within versus across time. For instance, clipping attenuated community‐level responses to a gradient in precipitation, suggesting that management could buffer community‐level responses to drought. However, precipitation effects were mild and likely to accentuate over time to produce further community change. [ABSTRACT FROM AUTHOR]

The frequency and intensity of heat waves (HWs) have increased in recent years, but it remains unclear how grassland ecosystems respond to such extreme weather. A 3‐year manipulative field experiment was conducted to simulate HWs under different mowing intensities in a Stipa krylovii steppe on the Mongolian Plateau to examine their effects on plant morphology, phenology, and community. At the species level, the morphology and phenology of the three main herb species (S. krylovii, Melilotoides ruthenica, and Potentilla tanacetifolia) showed species‐specific responses to the HW and mowing treatments. The major dominant species S. krylovii shed ~50% of the tiller outer layer to protect the internal tiller from HW stress thereby directly decreasing the heat load and water loss from green plant tissue and indirectly increasing the litter biomass. HWs also caused increases of community index (richness, diversity, and evenness) but also associated with a 30% decrease in the importance value of S. krylovii, whereas mowing enhanced this value by 27%. When HWs were combined with mowing, the joint forcing of mechanical damage and low carbon accumulation aggravated negative effects of stress on plant health and growth, which further decreased community index. We constructed a framework to fully describe the effects of HWs and mowing and their interrelationship on different ecological levels and explain how short‐term effects, such as extreme climate, produce long‐term effects on ecosystems. In conclusion, we found that synergisms between climate extremes (HWs) and human activities (mowing) can reduce ecosystem stability posing a threat to the grasslands. [ABSTRACT FROM AUTHOR]

The standard of practice for perioperative hair removal is largely based on research that is outdated and underpowered. Although there is evidence to support the practice of clipping instead of shaving, current recommendations are to remove hair only when absolutely necessary. Human hair is bacteria‐laden and challenging to disinfect, and clipping can be a safe method of hair removal that does not damage the skin. This article considers the removal of hair at the incision site with clippers, either before the patient enters the OR or in a manner that completely contains clipped hair, for every procedure, not just when absolutely necessary. There have been only two studies to date comparing clipping with no hair removal; more research is needed on this subject. [ABSTRACT FROM AUTHOR]

Plants' pattern of compensatory growth is often used to intuitively estimate their grazing tolerance. However, this tolerance is sometimes measured by the overall grazing tolerance index (overall GTI), which assumes that tolerance is a multivariate linear function of various underlying mechanisms. Because the interaction among mechanisms is not independent, the grazing tolerance expression based on overall GTI may be inconsistent with that based on compensatory growth. Through a manipulative field experiment from 2007 to 2012, we measured the responses of 12 traits of Elymus nutans to clipping under different resource availabilities in an alpine meadow and explored the compensatory aboveground biomass and the overall GTI to assess the possible differences between the two expressions of tolerance. Our results showed that these two expressions of tolerance were completely opposite. The expression based on overall GTI was over‐compensatory and did not vary with clipping and resource availability, while the expression based on compensatory aboveground biomass was under‐compensatory and altered to over‐compensation after fertilization. The over‐expression of highly variable traits with extremely high negative mean GTI to defoliation damage, the influence of random errors contained in traits considered, and the doubling weight of functional redundant traits greatly inflated the overall GTI, which leads to the inconsistency of the two tolerance expressions. This inconsistency is also associated with the different determining mechanisms of the two tolerance expressions. Our data suggest that plants' grazing tolerance is not a multivariate linear function of traits or mechanisms that determine grazing tolerance; the overall GTI is only a measure of traits' variability to defoliation damage. Our findings highlight that the tolerance of E. nutans mainly depends on the response of traits with lower variability to defoliation, and the overall GTI is not an ideal predictor for describing a single‐species tolerance to grazing. [ABSTRACT FROM AUTHOR]

• Primary colonisation in invasive ranges most commonly occurs in disturbed habitats, where anthropogenic disturbance may cause physical damage to plants. The tolerance to such damage may differ between cytotypes and among populations as a result of differing population histories (adaptive differentiation between ruderal verus natural habitats). Moreover, founder populations often experience inbreeding depression, the effects of which may increase through physical damage due to inbreeding-environment interactions. We aimed to understand how such colonisation processes differ between diploid and tetraploid centaurea stoebe populations, with a view to understanding why only tetraploids are invasive. • We conducted a clipping experiment (frequency: zero, once or twice in the growing season) on inbred versus outbred offspring originating from 37C. stoebe populations of varying cytotype, range and habitat type (natural versus ruderal). Aboveground biomass was harvested at the end of the vegetation period, while re-sprouting success was recorded in the following spring. •clipping reduced re-sprouting success and biomass, which was significantly more pronounced in natural than in ruderal populations. Inbreeding depression was not detected under benign conditions, but became increasingly apparent in biomass when plants were clipped. The effects of clipping and inbreeding did not differ between cytotypes. • Adaptive differentiation in disturbance tolerance was higher among populations than between cytotypes, which highlights the potential of pre-adaptation in ruderal populations during early colonisation on anthropogenically disturbed sites. While the consequences of inbreeding increased through clipping-mediated stress, they were comparable between cytotypes, and consequently do not contribute to understanding the cytotype shift in the invasive range. [ABSTRACT FROM AUTHOR]

Deserts are increasing in extent globally, but existing deserts are decreasing in health. The basic biology and ecology of foundation plant species in deserts are limited. This is a direct study that provides an estimate of the capacity for a locally dominant foundation shrub species in California to recover from damage. Desert shrubs are cleared and damaged by humans for many purposes including agriculture, oil and gas production, and sustainable energy developments; we need to know whether foundation species consistently facilitate the abundance and diversity of other plants in high-stress ecosystems and whether they can recover. A total of 20 Ephedra californica shrubs were clipped to the ground at a single site and systematically resampled for regrowth 2 years later. These shrubs were damaged once and regrew rapidly, and relatively, larger shrubs were not more resilient. This study provides evidence for what we termed the 'Groot Effect' because smaller individuals of this shrub species can recover from significant aboveground damage and continue to have positive effects on other plant species (similar to the popular culture reference to a benefactor tree species). The density of other plant species was consistently facilitated while effects on diversity varied with season. These findings confirm that E. californica is a foundation species that can be an important restoration tool within the deserts of California in spite of extreme cycles of drought and physical damage to its canopy. [ABSTRACT FROM AUTHOR]

Global reactive nitrogen (N) is projected to further increase in the coming years. Previous studies have demonstrated that N enrichment weakens the temporal stability of the ecosystem and the primary productivity through decreased biodiversity and species asynchrony. Mowing is a globally common practise in grasslands; and infrequent mowing can maintain or increase plant diversity under N enrichment conditions. However, it is unclear how infrequent mowing affects ecosystem stability in the face of N enrichment., By independently manipulating the frequency (twice vs. monthly additions per year) and rate (i.e. 0, 1, 2, 3, 5, 10, 15, 20, and 50 g N m−2 year−1) of NH4 NO3 inputs and mowing (unmown vs. mown) over 3 years (2011-2013) in a temperate grassland of northern China, we aimed to examine the interactive effects of N enrichment and mowing on ecosystem stability., The results show that mowing maintained a positive relationship between species richness and ecosystem stability despite N addition, but that it exacerbated the negative effects of N addition on ecosystem stability. Mowing increased mean primary productivity and plant species richness, but it also increased the synchrony of population fluctuations and the variability of primary productivity under N enrichment, thereby contributing to a decline in the ecosystem stability., Thus, our study reveals that infrequent mowing can buffer the negative effects of N enrichment on biodiversity to some extent and further increase the primary productivity, but it exacerbates the loss of ecosystem stability with N enrichment, thereby threatening local and/or semiarid regional food security. [ABSTRACT FROM AUTHOR]

Questions Are there interspecific differences in resprouting after cutting and burning among woody species encroaching temperate grasslands? Are alien woody species more successful than natives in their resprouting after the two treatments proposed to control shrub encroachment? Is resprouting influenced by age of the individuals? Does resprouting differ between cutting and burning? Location Temperate grasslands encroached by shrubs, Transylvania, Romania. Methods We investigated the resprouting after cutting or burning of four shrub species ( Cornus sanguinea, Crataegus monogyna, Prunus spinosa and Rosa canina) encroaching grasslands in field sites 3 yr following treatments. We compared the resprouting ability of shrubs between species and treatments and analysed the relationship between the number of resprouts and stump diameter, as a proxy for age. In a common garden experiment on 1-yr-old individuals we compared resprouting after cutting and burning between three native ( C. sanguinea, C. monogyna and P. spinosa) and three alien woody species ( Ailanthus altissima, Elaeagnus angustifolia and Hippophae rhamnoides) during one growing season. Results C. monogyna produced the largest number of resprouts in the field study, and H. rhamnoides in the experimental study. Overall, resprouting ability of alien woody species did not differ from that of natives. In the field study, we found an increasing number of resprouts with increasing stump diameter, and the rate of increase in the number of resprouts was highest in C. monogyna. We detected no difference in the resprouting of woody species between cutting and burning treatments either in the field or in the experimental study. Conclusions Our study suggests that the success of encroachment control in grasslands does not depend on treatment type, but on the woody species composition and age of individuals. Grasslands encroached by C. monogyna or H. rhamnoides will be more labour-intensive to restore and maintain free of shrubs. Restoration measures should be implemented in the early stage of shrub encroachment since younger shrubs have lower resprouting ability. Burning and cutting may be equally effective in controlling shrub encroachment, but treatments should be more intensive than in the current study in order to damage the resprouting buds and arrest resprouting. [ABSTRACT FROM AUTHOR]

Background and purpose The role of corticosteroids in the treatment of patients with aneurysmal subarachnoid haemorrhage ( SAH) has remained controversial for decades. Recent studies have suggested that the administration of corticosteroids in SAH patients is associated with favourable outcomes. Given their significant adverse effects, it is essential to identify those patients who will benefit from treatment with corticosteroids. Methods A retrospective analysis of a prospectively collected cohort ( n = 306) with SAH who were treated by microsurgical clipping or endovascular intervention was performed. The role of dexamethasone administration was analysed with regard to clinical conditions and SAH-related complications. Outcome was assessed at discharge and during follow-up using the Glasgow Outcome Scale ( GOS). Results Patients treated with dexamethasone presented with more episodes of hyperglycaemia ( P < 0.001), more overall infections ( P < 0.001) and more ventriculostomy-related infections ( P = 0.004). Multivariate analysis demonstrated that treatment with dexamethasone was associated with an unfavourable outcome at discharge ( GOS 1-3) [odds ratio ( OR) 2.814, 95% confidence interval ( CI) 1.440-5.497, P = 0.002]. In the subgroup of microsurgically treated patients, dexamethasone administration was associated with a favourable outcome at follow-up ( OR 0.193, 95% CI 0.06-0.621, P = 0.006). A higher risk for unfavourable outcome ( OR 3.382, 95% CI 1.67-6.849, P = 0.001) at discharge was observed in endovascularly treated patients who received dexamethasone but this had no impact on the outcome at follow-up. Conclusions Treatment with dexamethasone seems to be associated with a risk reduction for an unfavourable outcome in those patients who underwent microsurgical clipping. Despite an increased frequency of adverse effects, glucocorticoids may have a potential benefit in this specific surgical subgroup compared to endovascularly treated SAH patients. [ABSTRACT FROM AUTHOR]

High cell density (HCD) culture increases recombinant protein productivity via higher biomass. Compared to traditional fed-batch cultures, HCD is achieved by increased nutrient availability and removal of undesired metabolic components via regular medium replenishment. HCD process development is usually performed in instrumented lab-scale bioreactors (BR) that require time and labor for setup and operation. To potentially minimize resources and cost during HCD experiments, we evaluated a 2-week 50-mL Tubespin (TS) simulated HCD process where daily medium exchanges mimic the medium replacement rate in BR. To best assess performance differences, we cultured 13 different CHO cell lines in simulated HCD as satellites from simultaneous BR, and compared growth, metabolism, productivity and product quality. Overall, viability, cell-specific productivity and metabolism in TS were comparable to BR, but TS cell growth and final titer were lower by 25 and 15% in average, respectively. Peak viable cell densities were lower in TS than BR as a potential consequence of lower pH, different medium exchange strategy and dissolved oxygen limitations. Product quality attributes highly dependent on intrinsic molecule or cell line characteristics (e.g., galactosylation, afucosylation, aggregation) were comparable in both scales. However, product quality attributes that can change extracellularly as a function of incubation time (e.g., deamidation, C-terminal lysine, fragmentation) were in general lower in TS because of shorter residence time than HCD BR. Our characterization results and two case studies show that TS-simulated HCD cultures can be effectively used as a simple scale-down model for relative comparisons among cell lines for growth or productivity (e.g., clone screening), and for investigating effects on protein galactosylation. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:490-499, 2017 [ABSTRACT FROM AUTHOR]

Background Structured multidisciplinary care is an increasingly popular tool in the management of many complex disease processes; however, there is little published data regarding the effects of such a process on management of intracranial aneurysms and neurosurgical case loads. There is some resistance in the neurosurgical community to routine involvement of interventional neuroradiologists in the care of patients with intracranial aneurysms due to concerns regarding maintenance of neurosurgical case loads and training capabilities. At our tertiary Australian hospital, we have implemented a weekly multidisciplinary cerebrovascular meeting ( MDCVM) facilitating routine discussion of these cases between neurosurgeons and interventional neuroradiologists. Methods This study identified management modalities for ruptured and unruptured cerebral aneurysms diagnosed at our centre for a 2-year period before and after the implementation of MDCVM culminating in a 4-year retrospective cohort study. The pre- and post- MDCVM cohorts were well matched for demographics with 162 and 224 patients, respectively. Results There is no significant difference in percentage or absolute numbers of endovascular or surgical cases in the pre- MDCVM (103; 73.0% versus 38; 27.0%, respectively) or post- MDCVM cohorts (105; 79.5% versus 27; 20.5%, respectively), reflecting a maintained surgical case load after the implementation of MDCVM ( P = 0.21). There were no significant differences in any confounding variables including age, sex, aneurysm size/location, Fisher or World Federation of Neurosurgical Societies ( WFNS) grade. Conclusions Implementation of MDCVM did not impact on active management case loads with consistent numbers and percentages for both endovascular and microsurgical management. [ABSTRACT FROM AUTHOR]

Responses of grassland carbon (C) cycling to climate change and land use remain a major uncertainty in model prediction of future climate. To explore the impacts of global change on ecosystem C fluxes and the consequent changes in C storage, we have conducted a field experiment with warming (+3 °C), altered precipitation (doubled and halved), and annual clipping at the end of growing seasons in a mixed-grass prairie in Oklahoma, USA, from 2009 to 2013. Results showed that although ecosystem respiration ( ER) and gross primary production ( GPP) negatively responded to warming, net ecosystem exchange of CO2 ( NEE) did not significantly change under warming. Doubled precipitation stimulated and halved precipitation suppressed ER and GPP equivalently, with the net outcome being unchanged in NEE. These results indicate that warming and altered precipitation do not necessarily have profound impacts on ecosystem C storage. In addition, we found that clipping enhanced NEE due to a stronger positive response of GPP compared to ER, indicating that clipping could potentially be an effective land practice that could increase C storage. No significant interactions between warming, altered precipitation, and clipping were observed. Meanwhile, we found that belowground net primary production ( BNPP) in general was sensitive to climate change and land use though no significant changes were found in NPP across treatments. Moreover, negative correlations of the ER/ GPP ratio with soil temperature and moisture did not differ across treatments, highlighting the roles of abiotic factors in mediating ecosystem C fluxes in this grassland. Importantly, our results suggest that belowground C cycling (e.g., BNPP) could respond to climate change with no alterations in ecosystem C storage in the same period. [ABSTRACT FROM AUTHOR]

Recently, orthogonal frequency-division multiplexing (OFDM) was applied to VLC systems owing to its high rate capability. On the other hand, a real-valued unipolar OFDM signal for VLC significantly reduces bandwidth efficiency. For practical implementation, channel estimation is required for data demodulation, which causes a further decrease in spectral efficiency. In addition, the large fluctuation of an OFDM signal results in poor illumination quality, such as chromaticity changes. This paper proposes a spectrally efficient method based on a hidden-pilot-aided precoding technology for VLC with less flickering than a conventional OFDM-based method. This approach can obtain channel information without any loss of bandwidth efficiency while ensuring illumination quality by reducing the flickering effect of an OFDM-based VLC. The simulation results show that the proposed method provides a 6.4% gain in bandwidth efficiency with a 4% reduction in flicker compared to a conventional OFDM-based method. [ABSTRACT FROM AUTHOR]

The efficiency of a terrestrial ecosystem to use rainfall in production is critical in regulating the ecological functions of the earth system under global change. However, it remains unclear how rain use efficiency ( RUE) will be altered by changes in climate and human activities such as biofuel harvest. In this study, we used RUE data from a long-term experiment in a tallgrass prairie to analyze the effects of warming and biofuel harvest (clipping). From 2000 to 2011, experimental warming enhanced RUE in most years, with larger positive effects in normal and wet than dry hydrological years. Clipping decreased RUE in dry and normal hydrological years, but had no impact on RUE in wet years. The observed RUE responses resulted from treatment-induced changes in both biologically ineffective (i.e., runoff and soil evaporation) and effective (i.e., transpiration) parts of precipitation. For example, litter cover was increased in warming plots, but reduced by clipping, leading to negative and positive effects on runoff and soil evaporation, respectively. The dominance of C4 species, which usually have higher water use efficiency than C3 species, was enhanced by warming, but reduced by clipping. Moreover, RUE was positively correlated with ratios of rainfall in the late growing season (June-August), when the growth of C4 plants was most active, relative to that in the other seasons. Our results indicate that RUE is positively influenced by climate warming, but negatively affected by biofuel harvest in tallgrass prairie of the Great Plains. These findings highlight the important roles of plant community structure and temporal distribution of precipitation in regulating ecosystem RUE. [ABSTRACT FROM AUTHOR]

A major difficulty in the design process of a local dimming system is to ensure a high image quality without annoying artifacts for any image content, with a high power saving at the same time. To solve this problem, a feedback method is proposed which dynamically adapts the control parameters of a local dimming system, based on the evaluation of criteria for the visual quality of the dimmed image. With these means a nearly constant visual quality for any image content can be achieved with high power savings of over 41%. In addition, a second method is presented which allows the display system to reach a desired mean power saving with the highest possible visual quality. [ABSTRACT FROM AUTHOR]

A single urea or amide functionality in a dumbbell-shaped guest can be 'clipped' by a macrocycle generated from a diamine and a dialdehyde through the templating effect of a Na+ ion (see scheme). The resulting imine-containing rotaxanes can then be reduced to allow isolation of stable amine-based rotaxanes. [ABSTRACT FROM AUTHOR]

Question Mesic grasslands experience a complex disturbance regime including frequent fire, grazing by large ungulates and strong inter-annual climate variability. As a result of climate change, growing season precipitation regimes are predicted to become more variable, with larger event sizes and longer dry periods resulting in more temporally dynamic soil moisture regimes. Increased climate variability is likely to interact with other disturbances, such as grazing, in grassland ecosystems. We investigated the individual and combined effects of increased rainfall variability and grazing on plant community composition, structure and function in an annually burned, native tallgrass prairie. Our overarching question was: are grazing impacts modified under a more variable precipitation regime? Location Konza Prairie, Kansas, USA. Methods Plots were established within a long-term rainfall manipulation experiment in which larger, but less frequent, rain events were imposed during the growing season without altering the total rain amount. We then simulated intense grazing pressure during one growing season by repeatedly clipping all graminoids to 5 cm and monitored recovery over 3 yr. Results Neither grazing nor rainfall treatments affected species richness; however, grazing decreased total and grass above-ground net primary production ( ANPP) and increased forb ANPP relative to ungrazed plots. Grass stem density recovered from intense grazing under ambient rainfall but did not fully recover, even after 2 yr in the altered rainfall treatment. Conclusions We found that increased rainfall variability had little effect on tallgrass prairie structure and function, while grazing had large effects. Grazing and increased rainfall variability interacted to suppress grass stem density and delayed recovery relative to controls. Although stem density was reduced, individual stem size increased, resulting in no net change in ANPP. This suggests that ANPP in grazed and ungrazed North American tallgrass prairie may be relatively resilient under more temporally variable precipitation regimes. [ABSTRACT FROM AUTHOR]

Understanding how soil respiration (Rs) and its source components respond to climate warming is crucial to improve model prediction of climate-carbon (C) feedback. We conducted a manipulation experiment by warming and clipping in a prairie dominated by invasive winter annual Bromus japonicas in Southern Great Plains, USA. Infrared radiators were used to simulate climate warming by 3 °C and clipping was used to mimic yearly hay mowing. Heterotrophic respiration (Rh) was measured inside deep collars (70 cm deep) that excluded root growth, while total soil respiration (Rs) was measured inside surface collars (2-3 cm deep). Autotrophic respiration (Ra) was calculated by subtracting Rh from Rs. During 3 years of experiment from January 2010 to December 2012, warming had no significant effect on Rs. The neutral response of Rs to warming was due to compensatory effects of warming on Rh and Ra. Warming significantly ( P < 0.05) stimulated Rh but decreased Ra. Clipping only marginally ( P < 0.1) increased Ra in 2010 but had no effect on Rh. There were no significant interactive effects of warming and clipping on Rs or its components. Warming stimulated annual Rh by 22.0%, but decreased annual Ra by 29.0% across the 3 years. The decreased Ra was primarily associated with the warming-induced decline of the winter annual productivity. Across the 3 years, warming increased Rh/Rs by 29.1% but clipping did not affect Rh/Rs. Our study highlights that climate warming may have contrasting effects on Rh and Ra in association with responses of plant productivity to warming. [ABSTRACT FROM AUTHOR]

The most well-known drawback of multi-carrier (MC) communication systems such as orthogonal frequency division multiplexing is the high dynamic range of its transmitted signal. However, it still has many advantages. One important advantage is the high spectral efficiency in a frequency selective channel environment. This spectral efficiency entitled MC system as 'capacity achieving' and indeed, nowadays, MC systems are able to get very close to the Shannon capacity bound. A very important element of the 'capacity achieving' is the water-filling (WF) power-loading method. This paper presents an innovative concept of combining the WF method with the 'clipping and filtering' peak to average power ratio reduction technique into a unified approach. The proposed system optimizes the channel capacity by controlling both the clipping amount together with the sub-carrier power-loading coefficients. This method will be shown to give greater performance than the traditional WF that does not use the clipping model. In addition, a computationally efficient algorithm that is suitable for real-time implementation is proposed here. [ABSTRACT FROM AUTHOR]

Grassland productivity in response to climate change and land use is a global concern. In order to explore the effects of climate change and land use on net primary productivity ( NPP), NPP partitioning [ fBNPP, defined as the fraction of belowground NPP ( BNPP) to NPP], and rain-use efficiency ( RUE) of NPP, we conducted a field experiment with warming (+3 °C), altered precipitation (double and half), and annual clipping in a mixed-grass prairie in Oklahoma, USA since July, 2009. Across the years, warming significantly increased BNPP, fBNPP, and RUEBNPP by an average of 11.6%, 2.8%, and 6.6%, respectively. This indicates that BNPP was more sensitive to warming than aboveground NPP ( ANPP) since warming did not change ANPP and RUEANPP much. Double precipitation stimulated ANPP, BNPP, and NPP but suppressed RUEANPP, RUEBNPP, and RUENPP while half precipitation decreased ANPP, BNPP, and NPP but increased RUEANPP, RUEBNPP, and RUENPP. Clipping interacted with altered precipitation in impacting RUEANPP, RUEBNPP, and RUENPP, suggesting land use could confound the effects of precipitation changes on ecosystem processes. Soil moisture was found to be a main factor in regulating variation in ANPP, BNPP, and NPP while soil temperature was the dominant factor influencing fBNPP. These findings suggest that BNPP is critical point to future research. Additionally, results from single-factor manipulative experiments should be treated with caution due to the non-additive interactive effects of warming with altered precipitation and land use (clipping). [ABSTRACT FROM AUTHOR]

ABSTRACT A novel model for constant energy constellation (the data is drawn from equi-energy symbols) discrete time orthogonal frequency-division multiplexing (OFDM) signal is presented. On the basis of this model, the moments of the OFDM signal's envelope maximum and the moments of the energy of the clipped portion of the signal are computed. It is also shown that the rate at which the expected value of the maximum scales with the length of the signal coincides with Halasz's result. Simulations are presented, which show that this model gives much better results than the conventional Gaussian model in approximation of statistical properties of an OFDM signal. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: The usefulness of clip traction in endoscopic submucosal dissection (ESD) for early esophageal carcinoma was investigated. Methods: A total of 87 patients who underwent ESD for esophageal squamous cell carcinoma were included in the study. The hook knife method was used for ESD. Twenty patients underwent ESD without clip traction (non-clip group) and 67 underwent procedures in which clip traction was used (clip group). A clip with a string was attached to the oral edge of the lesion after mucosal incision in the clip group. Results: ESD was successful in all cases. Wide exposure of the submucosal tissue below the lesion was obtained by applying tension to the clip traction. The duration of ESD was shorter in the clip group, and there was a significant difference in duration between the non-clip and clip groups. There were no complications of ESD in the clip group, but muscle layer injury occurred in three patients in the non-clip group. Conclusion: Clip traction shortens operating time and is safer in esophageal ESD. Clip traction is recommended as a useful auxiliary procedure. [ABSTRACT FROM AUTHOR]

Aim The purpose of this study was to describe prognostic factors for cerebral infraction and outcome in patients undergoing neurosurgical clipping or endovascular coiling with intracranial aneurysms. In addition, we compared the incidence of cerebral infraction and outcome in patients treated with neurosurgical clipping or endovascular coiling. Patients and Methods Data were analysed from 972 patients with intracranial aneurysms enrolled at Union Hospital between September 2007 and May 2011. Multivariable logistic regression with backwards selection were derived to define independent predictors of cerebral infraction and outcome in patients undergoing neurosurgical clipping or endovascular coiling of intracranial aneurysms. Results In the multivariable analysis, cerebral infraction was not associated with the history of hypertension, smoking, diabetes mellitus, aneurysmal size and number, the use of dehydrant and low-dosage i.v. nimodipine. Factors that contributed most to variation in cerebral infraction, in descending order of importance, were Fisher grade of the computed tomography scan, aneurysmal location, Hunt and Hess scale grade on admission, rupture times, the operating day from first rupture, increasing age, treatment modality and male sex. Predictors of poor outcome, also in descending order of importance, were Hunt and Hess scale grade IV, rupture one to three times, cerebral infraction, Fisher grade 3, operation on 4th−14th day from rupture, diabetes mellitus history, age > 55 years, hypertension history, smoking history and neurosurgical clipping. Conclusion Although most prognostic factors for cerebral infraction and outcome after subarachnoid haemorrhage are already present on admission, for suitable patients endovascular coiling and early intervention are recommended. [ABSTRACT FROM AUTHOR]

The dynamics of belowground net primary productivity ( BNPP) is of fundamental importance in understanding carbon (C) allocation and storage in grasslands. However, our knowledge of the interannual variability in response of BNPP to ongoing global warming is limited. In this study, we explored temporal responses of BNPP and net primary productivity ( NPP) partitioning to warming and clipping in a tallgrass prairie in Oklahoma, USA. Infrared heaters were used to elevate soil temperature by approximately 2 °C since November 1999. Annual clipping was to mimic hay harvest. On average from 2005 to 2009, warming increased BNPP by 41.89% in the unclipped subplots and 66.93% in the clipped subplots, with significant increase observed in wet years. Clipping also had significant positive impact on BNPP, which was mostly found under warming. Overall, fBNPP, the fraction of BNPP to NPP, increased under both warming and clipping treatments, more in dry years. Water availability (either precipitation or soil moisture) was the most limiting factor for both BNPP and fBNPP. It strongly dominated the interannual variability in NPP, fBNPP, and their responses to warming and clipping. Our results suggest that water availability regulates tallgrass prairie's responses to warming and land use change, which may eventually influence the global C cycle. With increasing variability in future precipitation patterns, warming effects on the vegetation in this region may become less predictable. [ABSTRACT FROM AUTHOR]

The invasion of natural ecosystems by exotic species is a major threat to biodiversity on a local, regional, and global scale. Endemic island flora are particularly vulnerable to invasive species. Bidens pilosa var. radiata is a common invasive weed of roadsides, which are subject to clipping, on Japanese subtropical islands. To assess compensation by the weed to damage by clipping, a pot experiment was conducted under common garden conditions. The above-ground parts were clipped with pruning shears at various frequencies, ranging from no clipping (the control) to clipping at 4-16 week intervals for 32 weeks in summer. The clipped individuals regenerated new branches from the axillary buds and flowered for ≤12 weeks after the clipping. The regeneration after the clipping gave rise to secondary reproduction, whereas minimal regeneration occurred in the unclipped individuals after the maturation of the fruit. Consequently, the total flower head mass, represented by the dry weight of the inflorescences throughout the experiment, was higher on the individuals that were clipped at 12 and 16 week intervals than on the unclipped individuals, suggesting overcompensation in fecundity. At the higher frequencies of above-ground clipping, the flower head mass was suppressed at 8 week clipping intervals, while both the flower head mass and the productive biomass were suppressed at 4 week clipping intervals. This indicates that clipping at intervals of ≤8 weeks is required to prevent the reproduction of this weed. [ABSTRACT FROM AUTHOR]

Intracranial aneurysm rupture has the highest levels of mortality and morbidity among all stroke types. To answer the question of how and why different well-established and novel treatment techniques were developed, it is crucial to understand the historic hurdles and breakthroughs in intracranial aneurysm treatment over the years. Literature review was carried out using PubMed and the electronic database of Surgical Practice. Relevant articles were retrieved for further appraisal. The neuro-endovascular treatment field has evolved from the use of detachable balloons or coils to the use of bioactive coils, balloon test occlusion, the balloon- and stent-assisted techniques, and the flow-diverting stent. The application of intraoperative indocyanine green angiography has also improved microsurgical treatment in recent years. Advances in endovascular technology have made coiling the cornerstone of intracranial aneurysm treatment. However, the roles played by different endovascular tools need to be better understood. [ABSTRACT FROM AUTHOR]

Endoscopic submucosal dissection (ESD) for early gastric carcinoma has been widely performed in Japan. In this technique, when hemorrhaging from vessels is observed, the bleeding point is coagulated using hemostatic forceps with the soft coagulation. There have been reports that using hemostatic forceps with soft coagulation is a safe and effective method of controlling upper gastrointestinal ulcer bleeding. However, there have been no reports regarding the comparative effectiveness of hemostatic forceps and clipping in upper gastrointestinal ulcer bleeding. Between April 2003 and December 2008, a total of 124 patients with gastric ulcer bleeding causing melena or hematochezia were treated with endoscopic hemostasis in our hospital. Two endoscopic hemostatic methods were used for different groups of patients: coagulation with hemostatic forceps was used for Group A and clipping was used for Group B. The rate of additional treatment required after the initial procedure was 28.6% (8/28) for Group A and 79.2% (76/96) for Group B, indicating a significantly lower rate for Group A than that for Group B ( P < 0.01). Additional treatment consists of a hypertonic saline epinephrine injection. The rebleeding rate was 3.6% (1/28) for Group A and 8.3% (8/96) for Group B, again indicating a lower rate for Group A than for Group B. Finally, successful endoscopic hemostasis was 100% in both groups. Using the soft coagulation mode of hemostatic forceps is shown to be a safe, easy and effective method of controlling gastric ulcer bleeding in relation to clipping. [ABSTRACT FROM AUTHOR]

1. aged and natural ecosystems, herbivory can have a major impact on plant growth. Defoliation and shoot removal reduce the photosynthetic capacity of plants and are also thought to reduce allocation of carbon to roots and mycorrhizal fungi. However, evidence supporting this assumption remains equivocal. 2. ducted a meta-analysis of 99 experiments, from 33 publications, measuring arbuscular and ectomycorrhizal colonization of roots after real or simulated herbivory removed leaves or shoots. We also explored how effects were moderated by the type of mycorrhiza, fertilization, experimental setting (laboratory or field), treatment (real herbivory of shoots, real herbivory of leaves, simulated herbivory of shoots, simulated herbivory of leaves), type of host plant, duration of the experiment and year of publication. 3. Overall, herbivory reduced mycorrhizal colonization by about 3 percentage points. Treatment, host plant type and year of publication were the only significant moderators, with real or simulated herbivory of leaves and real herbivory of shoots suppressing colonization, while simulated removal of shoots tended to increase colonization. Herbivory reduced colonization of perennial grasses and deciduous trees by about 4 and 8 percentage points, respectively. Mycorrhizal colonization of annual crops was reduced by about 12 percentage points, although this was not significantly different from zero. Mycorrhizal colonization of perennial forbs and evergreen trees was also unaffected by herbivory, and colonization of mixtures of perennial grasses and forbs increased by about 15 percentage points following herbivory. Effect size increased with year of publication, likely due to shifts in experimental designs towards systems more likely to show positive effects of herbivory on mycorrhiza. 4. Synthesis. Our results challenge the carbon-limitation hypothesis and suggest that herbivory, real or simulated, reduces mycorrhizal colonization by biologically meaningful amounts only in a limited subset of systems. [ABSTRACT FROM AUTHOR]

This study was conducted to examine the effects of clipping and nutrient addition on plant traits of a dominant perennial forb species, Heteropappus altaicus (Willd.) Novopokr. (Compositae), at both the individual and population levels in a temperate steppe in northern China. A nested experimental design was used with clipping as the main factor and nutrient, including nitrogen (N), phosphorus (P) and both, addition as the second factor. The main effect of clipping reduced plant height, aboveground biomass (AGB) per plant, and pollen production per floret by 15.8, 34.3, 28.0% (all p < 0.05), respectively, but enhanced reproductive allocation and population density by 8 and 28.2% (both p < 0.05), respectively, suggesting contrary effects of clipping on H. altaicus traits at the individual and population levels. N addition significantly stimulated plant height, AGB per plant, reproductive allocation, pollen diameter, and pistil length, but decreased population density. The main effects of P addition also stimulated the plant traits at individual level, but did not change population traits. The significant interactions of clipping and nitrogen addition were observed on AGB per plant, pollen production, and population density. The differential responses of H. altaicus at the individual and population levels to clipping and nutrient addition indicate that the future dynamics of H. altaicus in the temperate steppe are uncertain and need long-term research to demonstrate. [ABSTRACT FROM AUTHOR]

It has widely been documented that nitrogen (N) enrichment stimulates plant growth and net primary production. However, there is still dispute on how N addition affects net ecosystem CO2 exchange (NEE), which represents the balance between ecosystem carbon (C) uptake and release. We conducted an experimental study to examine effects of N addition on NEE in a temperate steppe in northern China from 2005 to 2008. N was added at a rate of 10 g N m−2 yr−1 with NH4NO3 alone or in combination with phosphorous (P, 5 g P2O5 m−2 yr−1) in both clipped and unclipped plots. Over the 4 years, N addition significantly stimulated growing-season NEE, on average, by 27%. Neither the main effects of P addition or clipping nor their interactions with N addition were statistically significant on NEE in any of the 4 years. However, the magnitude of N stimulation on NEE declined over time. N addition significantly increased NEE by 60% in 2005 and 21% in 2006, but its effect was not significant in 2007 and 2008. N-induced shift in species composition was primarily responsible for the declined N stimulation over time. The gradually increasing coverage of the upper canopy species ( Stipa krylovii) and standing litter accumulation induced light limitation on the lower canopy species ( Artemisia frigida). Thus, N-induced shifts in plant species composition strongly regulated the direct effects of N addition on C sequestration in the temperate steppe. [ABSTRACT FROM AUTHOR]

Persistency of plant growth is closely related to the manner of resource allocation; however, plants often shift the pattern of resource allocation depending on their growth condition. We examined how the plants with different levels of persistency change their resource allocation patterns in response to defoliation using three Lolium species: L. temulentum (annual); L. multiflorum (predominantly annual but occasionally overwinter); and L. perenne (perennial). We subjected the plants to clipping treatment by excising approximately 70% of the aboveground body parts of the plants from the three species, and compared the growth pattern of clipped plants with that of the intact controls. Lolium species with different persistency have developed different reaction norms for resource allocation to clipping treatment. After clipping, L. temulentum and L. multiflorum maintained the proportion of reproductive tillers and seed productivity resulting in an increase in the resource investment in the development of reproductive parts, which was compensated with the loss of allocation to the development of vegetative parts. Annual species, which can propagate themselves only through seed generation, possibly enhanced seed production to ensure regeneration under undesirable condition at the cost of vegetative growth. In contrast, L. perenne invested more resources in foliage development by reducing seed production in response to clipping treatment. Perennial plants that can endure adverse effects possibly allocate substantial portion of the resources to vegetative growth for ensuring survival. L. multiflorum showed similar regrowth habits with respect to the constant foliage and seed production per panicle as those of L. perenne, but differed from those of L. temulentum. This may be because the two former species have common ancestors. [ABSTRACT FROM AUTHOR]

Objectives To establish a standardised clipping method for the measurement of transepidermal water loss (TEWL) with a VapoMeter® in Beagle dogs and to identify the optimal anatomical site for TEWL measurement. Procedure TEWL values obtained from skin sites on five healthy Beagles clipped using two different blade angles (standard vs non-standard) were compared. TEWL values for 48 h were also obtained from seven different anatomical sites that had differing hair density. The hair was clipped in the intensively haired anatomical sites (head, lower and upper back and tail), but not clipped in the sparsely haired sites (ear, inguinal region, footpad). Results The TEWL values for the standard and non-standard clipping sites were 6.3 ± 1.31 and 27.2 ± 1.11 g/h/m2, respectively. We found the upper back among the clipped sites was the most appropriate site for TEWL measurement over 48 h after clipping, whereas among the unclipped sites the ear was the most appropriate, because the TEWL values from those anatomical sites had the least fluctuation and were less affected by movement. Conclusion The clipping method and anatomical site should be standardised in order to minimise the experimental variation in TEWL measurement in dogs. [ABSTRACT FROM AUTHOR]

As invasive plants in different life stages have different recovery potential against devegetation operation, how to optimize the proper timing (the time for single treatment or the starting time for repeated treatments) for eliminating them becomes an important topic in the management of invasive plants. The invasive plant Spartina alterniflora was selected in this study, and it was clipped as a devegetation example to examine how important treatment timing is for increasing control efficiency. The results illustrated that by either single or repeated clipping treatments within 1 year, clipping at florescence was more efficient for controlling S. alterniflora. On the other hand, increasing clipping frequency without proper timing might not enhance control efficiency, suggesting that treatments in proper timing might reduce the clipping frequency required for a specific control target. From a management point of view, each control method has its optimal treatment timing, thus, in order to improve the control efficiency, the control programs should be ideally designed in relation to the phenology of the target plant. Besides, repeated clipping showed significantly higher control efficiency in low tidal zone than in high tidal zone, implying that habitat dependence of invasive plant control efficiency is an important issue in the management of invasive plants. [ABSTRACT FROM AUTHOR]

One of the major challenges confronting grassland restoration of highly invaded communities is increasing the diversity of native species. There is surprisingly little research investigating how reconstructed native grasslands respond to common management techniques and how these techniques influence the relative establishment of both native grasses and forbs. Despite the diversity and wide distribution of native clovers in California, few practitioners incorporate them into grassland restoration plans. Conversely, non-native clovers have been seeded extensively onto California rangelands. This study addresses the following questions: (1) Using readily available management tools, is there a strategy that can benefit the growth of both planted native bunchgrasses and seeded clovers? (2) Do native bunchgrasses compete with establishing clovers and non-native grasses? (3) Do native and non-native clovers differ in their response to management treatments or in their productivity? Plots were established to test three factors in different combinations over 3 years: (1) early spring clipping, (2) initial broadleaf herbicide, and (3) native bunchgrass planting density. Native and non-native clovers were seeded in years 2 and 3. Early spring clipping did not have a significant effect on native bunchgrass cover, yet it did result in greater growth of native and non-native clovers. The direction of the response to broadleaf herbicide changed between years for native bunchgrasses and was consistently negative for native clovers. Plots with higher native grass densities did not adversely affect the seeded clovers, yet non-native grass cover was reduced. Native and non-native clovers exhibited similar responses to clipping and established at similar densities. [ABSTRACT FROM AUTHOR]

1. Slower growth after repetitive browsing of young trees has been attributed to a carbon (C) limitation, but data from long-term studies are lacking. To determine if repeated summer browsing causes a C (source) limitation in trees in the long-term, we analysed the non-structural carbohydrate (NSC) and nitrogen (N) concentrations and pools of Betula pubescens saplings subjected to different clipping treatments (unclipped, 33% and 66% shoot removal) for 7 years. 2. The short-term effect of browsing on C allocation was assessed by clipping trees with different browsing histories and analyzing their C and N responses within the same growing season. 3. Long-term repetitive summer browsing significantly decreased sapling growth and soluble sugar (SS) concentrations in fine roots. However, trees subjected to different browsing histories did not change their C partitioning into starch. Although trees with a different browsing history showed differences in the NSC concentrations and pools of leaves, these differences were not maintained through time. 4. Simulated browsing had no significant short-term effect on root C and N pools of birch trees, but it decreased all C pools in leaves, 1-year and current-year stems and the starch and total NSC pools in main stems. 5. We conclude that although browsing may cause a temporary decrease in C pools, B. pubescens trees are able to compensate for such losses and hence are not C-limited in the long-term. [ABSTRACT FROM AUTHOR]

Clonal traits such as clonal integration and storage functions of rhizomes or stolons may provide clonal plants with additional advantages against grazing over non-clonal plants. Here, we hypothesize that clonal species have a larger capacity for compensatory growth than co-occurring non-clonal species. In inland dunes in northern China, individual plants of two rhizomatous clonal species ( Bromus ircutensis and Psammochloa villosa) and two non-clonal ones ( Artemisia intramongolica and Astragalus melilotoides) were subjected to 0% (control), 50% (moderate) and 90% (heavy) shoot removal. Compared with control, heavy clipping greatly increased the relative growth rate in Bromus and Psammochloa, but decreased that in Artemisia and Astragalus. Heavy clipping affected above-ground dry weight and the number of modules more negatively in Artemisia and Astragalus than in Bromus and Psammochloa. These results support the hypothesis and suggest that clonal species are more tolerant to grazing than co-occurring non-clonal species in inland dunes. [ABSTRACT FROM AUTHOR]

Partitioning soil CO2 efflux into autotrophic ( RA) and heterotrophic ( RH) components is crucial for understanding their differential responses to climate change. We conducted a long-term experiment (2000–2005) to investigate effects of warming 2°C and yearly clipping on soil CO2 efflux and its components (i.e. RA and RH) in a tallgrass prairie ecosystem. Interannual variability of these fluxes was also examined. Deep collars (70 cm) were inserted into soil to measure RH. RA was quantified as the difference between soil CO2 efflux and RH. Warming treatment significantly stimulated soil CO2 efflux and its components (i.e. RA and RH) in most years. In contrast, yearly clipping significantly reduced soil CO2 efflux only in the last 2 years, although it decreased RH in every year of the study. Temperature sensitivity (i.e. apparent Q10 values) of soil CO2 efflux was slightly lower under warming ( P>0.05) and reduced considerably by clipping ( P<0.05) compared with that in the control. On average over the 4 years, RH accounted for approximately 65% of soil CO2 efflux with a range from 58% to 73% in the four treatments. Over seasons, the contribution of RH to soil CO2 efflux reached a maximum in winter (∼90%) and a minimum in summer (∼35%). Annual soil CO2 efflux did not vary substantially among years as precipitation did. The interannual variability of soil CO2 efflux may be mainly caused by precipitation distribution and summer severe drought. Our results suggest that the effects of warming and yearly clipping on soil CO2 efflux and its components did not result in significant changes in RH or RA contribution, and rainfall timing may be more important in determining interannual variability of soil CO2 efflux than the amount of annual precipitation. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to detect how a leading news paper, the Land Lantbruk in Stockholm, Sweden, informs the public and specifically the rural sector in Sweden and the Scandinavian countries concerning injury events (farm-related injury event) and the use of injury prevention and control. Injury reporting in the Land Lantbruk has been studied from the point of injury prevention and control. A study of injury prevention and rural health and safety in Australia shows that the newspaper The Land that serves Australia’s rural community should ‘be an under-utilised vehicle for news and commentary on rural health and safety issues’. Design: The study period was from January 2000 to February 2005. A total of 178 articles were reviewed and analysed. The articles were available on a newspaper database in the Land Lantbruk newspaper. Articles that addressed farm-related injury event and rural health and safety were chosen and organised into subgroups. Results: Tractor and motor vehicle safety (35%) was most common among the injury reporting. Although the newspaper Land Lantbruk provided excellent coverage of the causes of these events, the reports tended to focus on circumstances and did not provide information on injury prevention or the advantages of also coverage of the social and psychosocial long-term consequences of accidents. Conclusion: In the prevention work of reducing farm-related injuries in the rural sector in the Scandinavian countries and decreasing the human suffering represented by this health problem, rural politicians, insurance companies, rural authorities and also handicap organisations should listen more to the injured individuals and their own experiences relative to the difficulty of life after an accident. The reaction of family and relatives, and experiences of the long-term social consequences, have not been included in the media coverage. Journalists at the Land Lantbruk could also share experiences of the Swedish coverage of rural health and safety from Australian journalists from The Land. [ABSTRACT FROM AUTHOR]

In grasslands the proportionally largest emission of CO2 comes from the soil. This study aimed to assess how root respiration, a major flux component, is affected by land management and changes in land use. Respiration of roots, separated to classes of different diameter, was measured in 11 temperate mountain grasslands, including meadows, pastures and abandoned sites at three geographic locations. Specific root respiration was affected by nitrogen (N) concentration, root class and land use. The relationship between root N concentration and respiration differed between locations. With increasing root diameter there was a decrease in root respiration, N concentration, respiration per unit N and Q10. In grasslands abandoned for several years specific root respiration was lower than in meadows, pastures and a recently abandoned site. This was due to lower root N concentrations and/or lower respiration rates per unit N within each root class. Since root biomass was higher on abandoned grasslands, total ecosystem root respiration did not differ consistently between sites. Ecosystem root respiration showed distinct seasonal changes due to changes in root biomass, which were less pronounced on abandoned grasslands. Fine roots generally made up the largest portion of ecosystem root respiration, their contribution varying between 35% and 96%. On meadows, clipping increased soil and root respiration by increasing soil temperature. When corrected for temperature effects soil respiration was reduced by 20–50%, whilst root respiration was little affected, suggesting that carbohydrate reserves sustained root metabolism for several days and that microbial respiration strongly responded to short-term changes in assimilate supply. [ABSTRACT FROM AUTHOR]

Question: Two questions were posed: 1. Can an independent measure of relative competitive ability be used to predict the abundance of species in mixtures? 2. Is the success of those predictions affected by low fertility (stress simulation) or clipping (disturbance simulation)? Location: Greenhouse at Carleton University, Ottawa, Canada. Methods: We collected adult plant ramets of 11 species from the field and transplanted one ramet of each species into 56 containers of 60 L. We applied a 4 × 2 factorial combination of fertilization (none, full nutrients except N, full nutrients except P, full nutrients) and clipping (no clipping, clipping to 10 cm above soil) with seven replicates of each treatment. After two growing seasons the above- and below-ground biomass of each species was determined. Results: Regression analyses uncovered a significant positive relationship between plant biomass (measured in this study) and relative competitive ability (as measured in an independent study) under all experimental conditions. Both the mean slope and mean were lowest in treatments with low nutrients and highest in the full nutrient treatment (irrespective of clipping). Conclusions: Our results show that (1) at high fertility, relative competitive ability can generally predict the abundance of species in experimental plant communities, and (2) the intensity of competition (inferred from the magnitude of the slope or R²) increased with increasing nutrient supply, particularly nitrogen. [ABSTRACT FROM AUTHOR]

A glasshouse experiment was conducted to examine how the interactions of nutrient availability and partial ramet clipping affect growth, reproduction and biomass allocation ofCyperus esculentus, an invasive sedge. The plants sprouting from tubers were grown at low and high nutrient levels, and were subject either to no clipping, one, two or three clippings, with each clipping cutting half of the existing ramets at soil level. Our results show that nutrient availability and clipping frequency tended to independently affect most of growth, reproduction and biomass allocation parameters ofCyperus esculentusexamined in the present study. Increased supply of nutrients led to an increase in plant productivity and its associated traits. All of the traits, except for the number of ramets, displayed a decreasing pattern with increasing clipping frequency, indicating thatCyperus esculentushad undercompensatory responses to ramet clipping. It is likely that the patterns of plants’ response to clipping are species specific, and depend on morphological characters of species. Its susceptibility to ramet clipping can offer opportunities for controlling this invasive species through mechanical methods such as mowing. Clipping had little effects on biomass allocation; however, root weight fraction increased with increasing clipping frequency. While nutrient availability and clipping frequency had no influence on leaf carbon concentration at harvest, both of them increased leaf nitrogen concentration, and hence reduced leaf C/N ratio. [ABSTRACT FROM AUTHOR]

Question: Which is the response of the evergreen Quercus ilex and the deciduous Q. cerrioides to repeated disturbances? Location: central Catalonia (northeastern Spain), in the areas affected by two of the largest historically recorded wildfires in NE Spain: the Bages-Berguedà fire (24300 ha forested area burned in July 1994), and the Solsonès fire (14300 ha burned in 1998). Methods: Survival and growth of individuals of Quercus ilex and Q. cerrioides were evaluated in plants subjected lo different fire histories and experimental disturbances (burning, cutting or clipping) applied either before or after summer. Results: Survival was high (>99%), with both species showing a similar high resistance to disturbances. Growth after experimental disturbance was positively related to the size of the individual before the latest forest fire occurred. Fire history had a large effect on resprout growth, as the repeated incidence of disturbances lowered the capacity of individuals to grow. The type and season of experimental disturbance experienced by plants had a large effect. Individuals that experienced total above-ground loss had lower growth rates than those with partial loss. A similar pattern was observed in individuals disturbed after the summer in relation to those disturbed before summer. Conclusions: The larger growth rates recorded in Q. cerrioides across all fire histories and experimental treatments, and the higher vulnerability of Q. ilex to increased fire frequency, intensity of experimental disturbance, and disturbance .season, provide evidence for the relatively high susceptibility of the latter to repeated disturbances. This view disagrees with the larger resilience of this species compared to co-existing deciduous oaks, as reported. [ABSTRACT FROM AUTHOR]

Grassland communities are increasingly recognized as disturbance-dependent ecosystems, yet there are few replicated, multi-site studies documenting vegetation responses to varying frequencies and types of grassland disturbance. Even so, land managers frequently manipulate disturbance regimes in an attempt to favour native grassland plants over exotic species. We conducted a factorial experiment testing three frequencies of clipping combined with litter accumulation, litter removal, and soil disturbance within the highly threatened California coastal prairie plant community. We monitored the response of native/exotic, grass/forb plant guilds once a year for four years. More frequent clipping reduced cover of exotic grasses and favoured exotic forbs, whereas native species were largely unaffected by clipping frequency. Litter accumulation, litter removal, and soil disturbance did not affect vegetation composition. Effects of litter accumulation may take longer than our experiment allowed, and soil disturbance due to our treatments was not sufficiently strong to show consistent effects relative to mammalian soil disturbance. Treatment response of some plant guilds differed among sites, highlighting the importance of replicating experiments at several sites before recommending conservation management practices. [ABSTRACT FROM AUTHOR]

Abstract In order to facilitate interpretation and comparison of warming effects on ecosystems across various habitats, it is imperative to quantify changes in microclimate induced by warming facilities. This paper reports observed changes in air temperature, soil temperature and soil-moisture content under experimental warming and clipping in a tallgrass prairie in the Great Plains, USA. We used a factorial design with warming as the primary factor nested with clipping as the secondary factor. Infrared heater was used in order to simulate climatic warming and clipping to mimic mowing for hay or grazing. The warming treatment significantly increased daily mean and minimum air temperatures by 1.1 and 2.3 °C, respectively, but had no effect on daily maximum air temperature, resulting in reduced diurnal air-temperature range. Infrared heaters substantially increased daily maximum (2.5 and 3.5 °C), mean (2.0 and 2.6 °C) and minimum (1.8 and 2.1 °C) soil temperatures in both the unclipped and clipped subplots. Clipping also significantly increased daily maximum (3.4 and 4.3 °C) and mean (0.6 and 1.2 °C) soil temperatures, but decreased daily minimum soil temperature (1.0 and 0.6 °C in the control and warmed plots, respectively). Daily maximum, mean and minimum soil temperatures in the clipped, warmed subplots were 6.8, 3.2 and 1.1 °C higher than those in the unclipped, control subplots. Infrared heaters caused a reduction of 11.0% in soil moisture in the clipped subplots, but not in the unclipped subplots. Clipping reduced soil-moisture content by 17.7 and 22.7% in the control and warmed plots, respectively. Experimental warming and clipping interacted to exacerbate soil-moisture loss (26.7%). Overall, infrared heaters simulated climate warming well by enhancing downward infrared radiation and by reducing the diurnal air-temperature range. [ABSTRACT FROM AUTHOR]