bluuebunny/crossref_metadata_2025_split huggingface dataset:
Making the transition from discrete shot records to continuous seismic records and source wavefields, and its potential impact on survey efficiency and environmental footprint
Authors: Hegna Stian , Klüver Tilman , Lima Jostein , Wisløff Jens F. 
Published: October 2018

ABSTRACTA marine seismic method based on continuous source and receiver wavefields has been developed. The method requires continuous recording of the seismic data. The source that may consist of multiple source elements can emit signals continuously while moving. The ideal source wavefield to be used with this method should be as white as possible both in a temporal and a spatial sense to avoid deep notches in the spectrum enabling a stable multi‐dimensional deconvolution. White noise has such properties. However, equipment that can generate white noise does not exist. In order to generate a continuous source wavefield that is approaching the properties of white noise using existing equipment onboard marine seismic vessels, individual air‐guns can be triggered with short randomized time intervals in a near‐continuous fashion. The main potential benefits with the method are to reduce the environmental impact of marine seismic surveys and to improve acquisition efficiency. The peak sound pressure levels are significantly reduced by triggering one air‐gun at a time compared to conventional marine seismic sources. Sound exposure levels are also reduced in most directions. Since the method is based on continuous recording of seismic data and the air‐guns are triggered based on time and not based on position, there are less vessel speed limitations compared to conventional marine seismic data acquisition. Also, because the source wavefield is spread out in time, the wavefields emitted from source elements in different cross‐line positions can be designed such that the emitted wavefield is spatially white in this direction. This means that source elements in multiple cross‐line positions can be operated simultaneously, potentially improving the cross‐line sampling and/or the acquisition efficiency.
Individual differences in learning and biogenic amine levels influence the behavioural division between foraging honeybee scouts and recruits
Authors: Cook Chelsea N. , Mosqueiro Thiago , Brent Colin S. , Ozturk Cahit , Gadau Jürgen , Pinter‐Wollman Noa , Smith Brian H. 
Published: October 2018

Abstract

Animals must effectively balance the time they spend exploring the environment for new resources and exploiting them. One way that social animals accomplish this balance is by allocating these two tasks to different individuals. In honeybees, foraging is divided between scouts, which tend to explore the landscape for novel resources, and recruits, which tend to exploit these resources. Exploring the variation in cognitive and physiological mechanisms of foraging behaviour will provide a deeper understanding of how the division of labour is regulated in social insect societies.

Here, we uncover how honeybee foraging behaviour may be shaped by predispositions in performance of latent inhibition (LI), which is a form of non‐associative learning by which individuals learn to ignore familiar information.

We compared LI between scouts and recruits, hypothesizing that differences in learning would correlate with differences in foraging behaviour. Scouts seek out and encounter many new odours while locating novel resources, while recruits continuously forage from the same resource, even as its quality degrades.

We found that scouts show stronger LI than recruits, possibly reflecting their need to discriminate forage quality. We also found that scouts have significantly elevated tyramine compared to recruits. Furthermore, after associative odour training, recruits have significantly diminished octopamine in their brains compared to scouts.

These results suggest that individual variation in learning behaviour shapes the phenotypic behavioural differences between different types of honeybee foragers. These differences in turn have important consequences for how honeybee colonies interact with their environment. Uncovering the proximate mechanisms that influence individual variation in foraging behaviour is crucial for understanding the ecological context in which societies evolve.
How imperfect can land sparing be before land sharing is more favourable for wild species?
Authors: Balmford Ben , Green Rhys E. , Onial Malvika , Phalan Ben , Balmford Andrew 
Published: October 2018

Abstract

Two solutions, at opposite ends of a continuum, have been proposed to limit negative impacts of human agricultural demand on biodiversity. Under land sharing, farmed landscapes are made as beneficial to wild species as possible, usually at the cost of lower yields. Under land sparing, yields are maximised and land not needed for farming is spared for nature. Multiple empirical studies have concluded that land‐sparing strategies would be the least detrimental to wild species, provided the land not needed for agriculture is actually spared for nature. However, the possibility of imperfections in the delivery of land sparing has not been comprehensively considered.

Land sparing can be imperfect in two main ways: land not required for food production may not be used for conservation (incomplete area sparing), and habitat spared may be of lower quality than that assessed in surveys (lower habitat quality sparing). Here we use published data relating population density to landscape‐level yield for birds and trees in Ghana (167 and 220 species respectively) and India (174 birds, 40 trees) to assess effects of imperfect land sparing on region‐wide population sizes and hence population viabilities.

We find that incomplete area and lower habitat quality imperfections both reduce the benefits of a land‐sparing strategy. However, sparing still outperforms sharing whenever ≥28% of land that could be spared is devoted to conservation, or the quality of land spared is ≥29% of the value of that surveyed. Thresholds are even lower under alternative assumptions of how population viability relates to population size and for species with small global ranges, and remain low even when both imperfections co‐occur.

Comparison of these thresholds with empirical data on the likely real‐world performance of land sparing suggests that reducing imperfections in its delivery would be highly beneficial. Nevertheless, given plausible relationships between population size and population viability, land sparing outperforms land sharing despite its imperfections.

Policy implications. Our results confirm that real‐world difficulties in implementing land sparing will have significant impacts on biodiversity. They also underscore the need for strategies which explicitly link yield increases to setting land aside for conservation, and for adoption of best practices when spared land requires restoration. However, land‐sparing approaches to meeting human agricultural demand remain the least detrimental to biodiversity, even with current imperfections in implementation.
Landscape structure regulates pest control provided by ants in sun coffee farms
Authors: Aristizábal Natalia , Metzger Jean Paul 
Published: October 2018

Abstract

Ants play a fundamental role in coffee pest control. Despite this, there is a lack of understanding about how landscape configuration and composition regulate the ecosystem service provided by ants in sun coffee farms within highly fragmented landscapes.

We measured whether landscape structure influences ants’ ability to regulate coffee berry borer (CBB) in sun coffee farms in Southeastern Brazil. Considering the ecological interactions between ants and CBB at three different stages of pest control (reduction of CBB presence, CBB infestation, and CBB bean damage), we measured pest control among 10 landscapes that represented a gradual difference in forest and coffee cover. We manipulated ants through exclusion experiments and tested whether interactions between ants and different landscape structure metrics (distance to forest fragments, 2‐km‐level forest cover, and 300‐m‐level forest and coffee cover) influenced pest control.

The presence of ants reduced CBB presence and CBB damage by up to 40%. We show how pest control service indicators change depending on the landscape level. The probability of CBB presence increased with expanding coffee and forest cover at the 300‐m‐level but decreased at the 2‐km‐level. CBB infestation reduced further after 25 m from forest edges, suggesting ants that provide these ecosystem services are adapted to matrix conditions in sun coffee farms. Ants reduced CBB presence, CBB infestation, and CBB damage in landscapes with at least 40% 2‐km‐level forest cover. Beyond this threshold, there is a turning point for ecological processes involved in pest control.

Synthesis and applications. This is the first long‐term branch‐level exclusion experiment to present strong evidence of ants as efficient providers of pest control in sun coffee farms. We show how landscape structure modulates key ecological processes involved in three different ant‐CBB interactions that regulate CBB populations. Forest cover measured at different landscape levels yielded different results for CBB presence, emphasizing the importance of multi‐scale studies for landscape management. Considering surrounding forest cover and crop proximity to forest fragments in planning the spatial arrangement of coffee farms can thus both improve pest control as well as contribute to biodiversity conservation.
Abiotic heterogeneity underlies trait‐based competition and assembly
Authors: Borges Isabela L. , Forsyth Leila Z. , Start Denon , Gilbert Benjamin 
Published: October 2018

Abstract

The fitness of individual species depends on their ability to persist and establish at low densities, just as the diversity of ecological communities depends on the establishment and persistence of low‐density, “invader” species. Theory predicts that abiotic conditions and the competitive make‐up of resident communities jointly shape invader fitness, limiting the phenotypic identity of successful invaders.

We use an invasion experiment to ask how competitive traits of 20 introduced plant species alter their absolute fitness in fragments that differ in size, abiotic conditions, and traits of the resident community.

We show that abiotic conditions interact with both invader traits and resident functional diversity to determine invader survival. Optimal invader traits depended on the soil characteristics, while greater resident trait diversity lowered invader fitness and had especially strong effects in low‐resource environments. Unlike other abiotic conditions, fragment size had consistent effects irrespective of invader identity, decreasing survival in larger fragments.

Synthesis. Our results illustrate how the abiotic environment mediates the effects of resident and invader traits on establishment, creating fitness landscapes that structure local diversity and the functional identities of successful species.
The type of nutrient limitation affects the plant species richness–productivity relationship: Evidence from dry grasslands across Eurasia
Authors: Palpurina Salza , Chytrý Milan , Hölzel Norbert , Tichý Lubomír , Wagner Viktoria , Horsák Michal , Axmanová Irena , Hájek Michal , Hájková Petra , Freitag Martin , Lososová Zdeňka , Mathar Wanja , Tzonev Rossen , Danihelka Jiří , Dřevojan Pavel 
Published: October 2018

Abstract

The species richness–productivity relationship is one of the most debated patterns in ecology. Species coexistence theory suggests that it could be tightly linked to the type of nutrient limitation (no limitation, single‐nutrient limitation, colimitation by several nutrients). Yet, the effects of nutrient limitation on the species richness–productivity relationship have been rarely studied at the regional and continental scales.

Combining the predictions of the humped‐back model and the niche dimension hypothesis, we hypothesized that an increase in plant species richness with the number of different limiting nutrients is detectable only at higher productivity levels, at which competition for nutrients is more intense. Therefore, we expected the shape of the diversity–productivity relationship to differ between sites colimited by nitrogen (N) and phosphorus (P), sites limited by a single nutrient (either N or P), and sites not limited by any of these nutrients.

To test this hypothesis, we used species richness data collected in 10 m × 10 m plots at 694 temperate dry grassland sites across eight regions in northern Eurasia. Productivity ranged from 10 to ~500 g/m2 of above‐ground standing biomass. The type of nutrient limitation was identified by critical nutrient ratios alone and their combination with critical nutrient concentrations measured in the plant tissue. Relationships were analysed using generalized linear and mixed‐effect models.

In line with our expectations, species richness of Eurasian temperate dry grasslands increased more steeply and peaked higher under higher productivity levels at N&P‐colimited sites. When nutrient limitation was assessed by both ratios and concentrations, species richness at N&P‐colimited sites continued to increase monotonically until the maximum productivity sampled in this study. In contrast, at sites with a single‐nutrient limitation or no limitation, the peak in species richness was lower and occurred at a lower productivity of about 300–400 g/m2.

Synthesis. We provide the first evidence that the species richness–productivity relationship may depend on the type of nutrient limitation as predicted by the species coexistence theory. To generalize these findings, the role of nutrient limitation needs to be tested in other ecosystems, including more productive plant communities.
N‐Acetylcysteine potentiates the haemodynamic‐improving effect of sildenafil in a rabbit model of acute pulmonary thromboembolism via the p38 MAPK pathway
Authors: Zhang Ruipeng , Wang Yang , Pan Longfei , Tian Hongyan 
Published: October 2018

SummaryThe current study aimed to investigate the effects of sildenafil and N‐acetylcysteine (NAC) on the haemodynamics in a rabbit model of acute pulmonary thromboembolism (APT). We developed an APT model using healthy male China big‐ear rabbits (2.7 ± 0.4 kg). The rabbits were divided into five groups subjected to various interventions. We recorded the haemodynamic parameters and assessed the oxidative stress and lipid peroxidation response in the groups. Additionally, we detected apoptosis‐associated molecules, FoxO1, Bad and Bcl‐2, in the lung tissue. Gelatine zymography was used to detect matrix metalloproteinase (MMP) activity in bronchoalveolar lavage (BLA). Pulmonary artery endothelial cells were isolated, and their apoptosis rates and MMP activity were assayed. N‐acetylcysteine potentiated the haemodynamic‐improving effect of sildenafil and significantly inhibited the oxidative stress response. N‐acetylcysteine combined with sildenafil decreased MMP‐2 and MMP‐9 activity and NO consumption and inhibited apoptosis of pulmonary arterial endothelial cells. Moreover, NAC combined with sildenafil inhibited the expression of MCP‐1 and p‐p38 MAPK. Thus, NAC potentiates the haemodynamic‐improving effect of sildenafil in a rabbit model of acute pulmonary thromboembolism via the MCP‐1 and p38 MAPK signalling pathway. This study may provide a promising treatment method for APT.
Unfolding the pleiotropic facades of rosuvastatin in therapeutic intervention of myriads of neurodegenerative disorders
Authors: Husain Ibraheem , Khan Sana , Khan Saba , Madaan Tushar , Kumar Sanjeev , Najmi Abul K. 
Published: October 2018

SummaryRosuvastatin, a 3‐hydroxy‐3‐methylglutaryl‐coenzyme (HMG‐CoA) reductase inhibitor, and one of the most popular antihyperlipidemic medications have been found to possess pharmacodynamic activities much different from its usual indication. Recent research studies have revealed the efficacy of rosuvastatin in attenuating neuroinflammation, reducing the progression of Alzheimer's disease, providing protection against cerebral ischaemia and spinal cord injury as well as ameliorating epilepsy. Mechanisms behind the neuroprotective potential of rosuvastatin can be attributed to its pleiotropic effects, independent of its ability to inhibit HMG‐CoA reductase. These processes include modulation of several cellular pathways, isoprenylation, effects on oxidative stress, nitrosative levels, inflammation, and immune response. This review aims to assimilate and summarize recent findings on the pharmacological actions of rosuvastatin in attenuating neurological disorders in order to guide future research in this space.
Iron‐ and aluminium‐induced depletion of molybdenum in acidic environments impedes the nitrogen cycle
Authors: Ge Xiaoxuan , Vaccaro Brian J. , Thorgersen Michael P. , Poole Farris L. , Majumder Erica L. , Zane Grant M. , De León Kara B. , Lancaster W. Andrew , Moon Ji Won , Paradis Charles J. , von Netzer Frederick , Stahl David A. , Adams Paul D. , Arkin Adam P. , Wall Judy D. , Hazen Terry C. , Adams Michael W. W. 
Published: October 2018

SummaryAnthropogenic nitrate contamination is a serious problem in many natural environments. Nitrate removal by microbial action is dependent on the metal molybdenum (Mo), which is required by nitrate reductase for denitrification and dissimilatory nitrate reduction to ammonium. The soluble form of Mo, molybdate (MoO42−), is incorporated into and adsorbed by iron (Fe) and aluminium (Al) (oxy) hydroxide minerals. Herein we used Oak Ridge Reservation (ORR) as a model nitrate‐contaminated acidic environment to investigate whether the formation of Fe‐ and Al‐precipitates could impede microbial nitrate removal by depleting Mo. We demonstrate that Fe and Al mineral formation that occurs as the pH of acidic synthetic groundwater is increased, decreases soluble Mo to low picomolar concentrations, a process proposed to mimic environmental diffusion of acidic contaminated groundwater. Analysis of ORR sediments revealed recalcitrant Mo in the contaminated core that co‐occurred with Fe and Al, consistent with Mo scavenging by Fe/Al precipitates. Nitrate removal by ORR isolate Pseudomonas fluorescens N2A2 is virtually abolished by Fe/Al precipitate‐induced Mo depletion. The depletion of naturally occurring Mo in nitrate‐ and Fe/Al‐contaminated acidic environments like ORR or acid mine drainage sites has the potential to impede microbial‐based nitrate reduction thereby extending the duration of nitrate in the environment.
Neutral mechanisms and niche differentiation in steady‐state insular microbial communities revealed by single cell analysis
Authors: Liu Zishu , Cichocki Nicolas , Hübschmann Thomas , Süring Christine , Ofiţeru Irina Dana , Sloan William T. , Grimm Volker , Müller Susann 
Published: October 2018

SummaryIn completely insular microbial communities, evolution of community structure cannot be shaped by the immigration of new members. In addition, when those communities are run in steady state, the influence of environmental factors on their assembly is reduced. Therefore, one would expect similar community structures under steady‐state conditions. Yet, in parallel setups, variability does occur. To reveal ecological mechanisms behind this phenomenon, five parallel reactors were studied at the single‐cell level for about 100 generations and community structure variations were quantified by ecological measures. Whether community variability can be controlled was tested by implementing soft temperature stressors as potential synchronizers. The low slope of the lognormal rank‐order abundance curves indicated a predominance of neutral mechanisms, i.e., where species identity plays no role. Variations in abundance ranks of subcommunities and increase in inter‐community pairwise β‐diversity over time support this. Niche differentiation was also observed, as indicated by steeper geometric‐like rank‐order abundance curves and increased numbers of correlations between abiotic and biotic parameters during initial adaptation and after disturbances. Still, neutral forces dominated community assembly. Our findings suggest that complex microbial communities in insular steady‐state environments can be difficult to synchronize and maintained in their original or desired structure, as they are non‐equilibrium systems.
The uses of disorder in negotiated information orders: information leveraging and changing norms in global public health governance
Authors: Heimer Carol A. 
Published: October 2018

AbstractThe SARS epidemic that broke out in late 2002 in China’s Guangdong Province highlighted the difficulties of reliance on state‐provided information when states have incentives to conceal discrediting information about public health threats. Using SARS and the International Health Regulations (IHR) as a starting point, this article examines negotiated information orders in global public health governance and the irregularities in the supply of data that underlie them. Negotiated information orders within and among the organizations in a field (here, e.g., the World Health Organization, member states, government agencies, and international non‐governmental organizations) spell out relationships among different categories of knowledge and non‐knowledge – what is known, acknowledged to be known, and available for use in decision making versus what might be known but cannot be acknowledged or officially used. Through information leveraging, technically sufficient information then becomes socially sufficient information. Thus it is especially information initially categorized as non‐knowledge – including suppressed data, rumour, unverified evidence, and unofficial information – that creates pressure for the renegotiation of information orders. The argument and evidence of the article also address broader issues about how international law and global norms are realigned, how global norms change, and how social groups manage risk.
The IMF failure that wasn’t: risk ignorance during the European debt crisis
Authors: Pénet Pierre 
Published: October 2018

AbstractThis article builds on ignorance studies to revisit how we understand the role of expertise in international policymaking. A fundamental component of ignorance is concealing what you know. For experts, risk ignorance is a strategic resource when the policymaking process becomes a contested exchange. This article covers IMF lending programmes in Europe in 2008–13 with a special focus on Greece. Empirical data is drawn from policy documents. I find that risk ignorance at the IMF resulted from a joint process of ‘private alteration’ and ‘public obfuscation’: the alteration of normal scenarios of debt sustainability in private negotiations worked in tandem with the obfuscation of programme risks in the public stage. The empirical contribution of this article is to show that the ‘failure’ of the IMF programme for Greece can be reconceptualized as ‘success’. The immediate goal of the programme was to bailout Greece’s creditors and avoid the breakup of European monetary institutions. In this respect, the programme was successful. But success came at a huge cost for Greece. Analytically, this article suggests that knowledge procurement based on empirical fact‐gathering is not always the ultimate goal of international organizations and the communities of experts working within them.