bluuebunny/crossref_metadata_2025 huggingface dataset:
Doing Together
Authors: Koivisto Juha , Pohjola Pasi
Published: July 2015

This article examines a systemic innovation model into which the relational approach of actor-network theory (ANT) has been incorporated. The article examines what the relational approach can contribute to the conceptualization of services and to the co-development and co-design activities of them. The article operates in the context of public welfare and health services, but its analysis might be applied in any other sector and with any other object of development as well. The article presents the systemic innovation model developed in a national Innovillage project in 2009-2013 in Finland. Further, the article studies how the model has been translated into practice in the design activities of a strategic development program of social and health sector run by the Ministry of Social Affairs and Health, Finland. In the discussion analytical and practical challenges of the model are specified and its further development is discussed.
Look Who's Acting!
Authors: Wolf Patricia , Troxler Peter
Published: July 2015

Digital maker communities democratize manufacturing through hands on learning, trans-disciplinary work and open source knowledge sharing. Little is known how knowledge sharing actually happens. This study applied actor-network-theory as underlying theoretical framework to a co-design project in a digital maker community – the teletransportation project. At the core of this project was a basic digital design for a cup that can be 3D-printed. The study showed that the different network types re-assemble around nodes that result from translations (and therefore transformations) of the initial project idea and the code that allowed to 3D-print a cup. It was able to show translations and the circular movement in the network as well as translation costs, time effects, intermediaries and mediators.
Gollum—Disassemble the Monster to Reassemble the Hybrid Actor
Authors: Dopieralski Marta
Published: July 2015

This article aims to outline the distributed agency within the creation of computer-generated characters for live-action movies that use Motion Capture techniques. This technique requires a tight interplay between human actors, technical artefacts and digital processes. With the help of ANT the relationships within this heterogeneous collective can be presented more precisely in order to assign agency to human and non-human participants. Considerations concerning a combined interplay of humans and computer-driven actions result in the figure of the hybrid actor. Gollum, a computer-generated character from Peter Jackson's adaptation of the Lord of the Rings, serves as case example to carve out the attributes of this composite agent. The aim of the article is to show how these types of agents tackle the film industry's inherent ontology revolving around human actors and their products. The article contributes an insight how the mentioned network reacts to the emerging problem of crediting in the context of Motion Capture as technical innovation and how the involved community preserves their notion of artistry.
A Secure Speech Content Authentication Algorithm Based on Discrete Fractional Fourier Transform
Authors: Zhang Fan , Liu Zhenghui , Wang Hongxia
Published: July 2015

Watermark schemes content-based provide one way to solve the veracity and integrity of speech content. Some existed content-based schemes are vulnerable to feature-analysed substitution attack. Aiming to solve the problems, a secure speech content authentication algorithm is proposed, on the basic of the undeterminate angle of discrete fractional fourier transform. In the paper, the definition and calculation of discrete fractional fourier transform are given. And the watermark generation method based on discrete fractional fourier transform is analyzed. Frame number and watermark bits are embedded into hybrid domain of scrambled signals. Compared with the existed watermark schemes, the features for watermark generation and embedding are secret, which improves the security of watermark system. Theoretical analysis and experimental evaluation results show that the proposed algorithm is inaudible, robust to desynchronous attacks and has the excellent ability of tamper detection and tamper location.
Block-based Reversible Fragile Watermarking for 2D Vector Map Authentication
Authors: Wang Nana , Zhao Xiangjun , Zhang Han
Published: July 2015

In this paper, the authors propose a block-based reversible watermarking method for 2D vector map authentication. In the scheme, they divide the features of a vector map into different categories of blocks, calculate an authentication watermark for each block, and embed the watermarks of different blocks using a reversible watermarking method based on virtual coordinates and a fragile watermarking algorithm based on concentric circles. While the block division ensures superior accuracy of tamper localization, the two watermarking methods provide recovery of the original content. Experimental results show that the proposed scheme has good invisibility, reversibility and computational complexity, and can accurately locate malicious attacks such as vertex modification/addition/deletion and feature modification/addition/deletion.
Digitally Enabled Service Transformations in Public Sector
Authors: Omar Amizan , Osmani Mohamad
Published: July 2015

In public sector transformation context, various studies have utilised institutional theory as a lens to explore the institutionalisation process of digital-enabled services. While institutional theory contributes towards understanding such transformation, limited explanation is offered on the underlying process, undermining the impact of interplay between institutional structure and actors in shaping organisational norms. Structuration theory has overcome this limitation by examining the creation and reproduction of the behaviours supporting formation of norms, through analysis of structures and actors as change agents. Using a systematic literature review, this paper aims to identify existing research that utilise institutional and structuration theories to study the institutionalisation of such transformation in public sector. The literature findings highlight that the scope of existing research is largely limited to the European context, indicating a need to extend the work beyond this.
Automatically Assessing Movement Capabilities through a Sensor-Based Telemonitoring System
Authors: Miralles Felip , Vargiu Eloisa , Casals Eloi , Cordero José Alejandro , Dauwalder Stefan
Published: July 2015

Telemonitoring makes possible to remotely assess health status and quality of life of individuals. By acquiring heterogeneous data coming from sensors (physiological, biometric, environmental; non-invasive, adaptive and transparent to user) and data coming from other sources to become aware of user context; by inferring user behaviour and detecting anomalies from this data; and by providing elaborated and smart knowledge to clinicians, therapists, carers, families, and the patients themselves, we will be able to foster preventive, predictive and personalized care actions, decisions and support. In this paper, by relying on a novel sensor-based telemonitoring and home support system, the authors are focused on monitoring mobility activities; the ultimate goal being to automatically assess quality of life of people. In particular, the authors are aimed at answering to an item of a quality-of-life questionnaire, namely “Mobility”. Although the authors are interested in assisting disabled people, we performed preliminary experiments with a healthy user, as a proof of concept. Results show that the approach is promising. Thus, the authors are now in the process to install the final system in a number of disabled people's homes under the umbrella of the BackHome project.
A Low Cost Pupillometry Approach
Authors: Petridis Sergios , Giannakopoulos Theodoros , Spyropoulos Constantine D.
Published: July 2015

The need for low-cost health monitoring is increasing with the continuous increase of the elderly population. In this context, unobtrusive audiovisual monitoring methods can be of great importance. More particularly, the diameter of the pupil is a valuable source of information, since, apart from pathological cases, it can reveal the emotional state, the fatigue and the ageing. To allow for unobtrusive monitoring to gain acceptance, one should seek for efficient methods of monitoring using common low-cost hardware. This paper describes a method for monitoring pupil sizes using a common, low-cost web camera in real time. The proposed approach detects the face and the eyes area at first stage. Subsequently, optimal iris and sclera location and radius, modeled as ellipses, are found using efficient spatial filtering. As a final step, the pupil center and radius is estimated by optimal filtering within the area of the iris. Experimental results show both the efficiency and the effectiveness of our approach.
Reconfiguration of Autonomous Robotics
Authors: Fu Yujian , Drager Steven
Published: July 2015

Autonomous robotics systems (ARSs) consist of multiple heterogeneous objects and intelligent inferences that are expected to take appropriate actions even in unforeseen circumstances. Dynamic reconfiguration of ARSs is a key enabling technology and plays a major role in the future cyber-enabled battle field. This research work, focused on the development of a formal approach to the specification and verification of reconfigurability of ARSs. Two typical problems w.r.t. the dynamic adaptation and reconfiguration of ARSs were identified and studied. The first problem is how to formally represent the ARSs and describe the reconfigurable behavior precisely so that the ARSs can adapt to the new changes. The second problem focuses on how to analyze and verify the formal model of the reconfiguration and ensure the correctness of the system during reconfiguration. Considering behavior preserving in the reconfiguration model, a net reconfigurations based on the natural transformation is introduced.
Localized Store-Operated Calcium Influx Represses CD95-Dependent Apoptotic Effects of Rituximab in Non-Hodgkin B Lymphomas
Authors: Vacher Pierre , Vacher Anne-Marie , Pineau Raphael , Latour Simon , Soubeyran Isabelle , Pangault Celine , Tarte Karin , Soubeyran Pierre , Ducret Thomas , Bresson-Bepoldin Laurence
Published: July 2015

The anti-CD20 mAb, rituximab, is routinely used to treat B cell malignancies. However, a majority of patients relapse. An improvement in the complete response was obtained by combining rituximab with chemotherapy, at the cost of increased toxicity. We reported that rituximab induced the colocalization of both the Orai1 Ca2+ release-activated Ca2+ channel (CRAC) and the endoplasmic reticulum Ca2+ sensor stromal interaction molecule 1 with CD20 and CD95 into a cluster, eliciting a polarized store-operated Ca2+ entry (SOCE). We observed that blocking this Ca2+ entry with downregulation of Orai1, pharmacological inhibitors, or reducing calcemia with hypocalcemic drugs sensitized human B lymphoma cell lines and primary human lymphoma cells to rituximab-induced apoptosis in vitro, and improved the antitumoral effect of rituximab in xenografted mice. This revealed that Ca2+ entry exerted a negative feedback loop on rituximab-induced apoptosis, suggesting that associating CRAC channel inhibitors or hypocalcemic agents with rituximab may improve the treatment of patients with B cell malignancies. The calcium-dependent proteins involved in this process appear to vary according to the B lymphoma cell type, suggesting that CRAC-channel targeting is likely to be more efficient than calcium-dependent protein targeting.
Identification of a New Exo-Endocytic Mechanism Triggered by Corticotropin-Releasing Hormone in Mast Cells
Authors: Balseiro-Gomez Santiago , Flores Juan A. , Acosta Jorge , Ramirez-Ponce M. Pilar , Ales Eva
Published: July 2015

The key role of mast cells (MC), either in development of inflammatory pathologies or in response to environmental stress, has been widely reported in recent years. Previous studies have described the effects of corticotropin-releasing hormone (CRH), which is released from inflamed tissues by cellular stress signals, on MC degranulation, a process possibly driven by selective secretion of mediators (piecemeal degranulation). In this study, we introduce a novel granular exo-endocytic pathway induced by CRH on peritoneal MC. We found that CRH triggers substantial exocytosis, which is even stronger than that induced by Ag stimulation and is characterized by large quantal size release events. Membrane fluorescence increases during stimulation in the presence of FM1-43 dye, corroborating the strength of this exocytosis, given that discrete upward fluorescence steps are often observed and suggesting that secretory granules are preferentially released by compound exocytosis. Additionally, the presence of a depot of large tubular organelles in the cytoplasm suggests that the exocytotic process is tightly coupled to a fast compound endocytosis. This CRH-stimulated mechanism is mediated through activation of adenylate cyclase and an increase of cAMP and intracellular Ca2+, as evidenced by the fact that the effect of CRH is mimicked by forskolin and 8-bromo-cAMP. Thus, these outcomes constitute new evidence for the critical role of MC in pathophysiological conditions within a cellular stress environment and an alternative membrane trafficking route mediated by CRH.
Intraocular pressure following 18 hours of systemic dehydration in ocular normotensive healthy subjects
Authors: Idu Faustina K. , George Gladys O. , Obika Leonard F.O.
Published: July 2015

Aim: To investigate the effect of dehydration on intraocular pressure (IOP). Subjects: The study population comprised 50 subjects (27 men and 23 women) with a mean age of 42.84 ± 2.64 years.Method: The subjects dehydrated for 18 hours. IOP was assessed in both eyes using the Perkins handheld applanation tonometer. Baseline measurement of IOP was taken before the subjects dehydrated for 18 hours and repeated after dehydration. Blood samples were taken before and after dehydration for the determination of plasma osmolality and plasma antidiuretic hormone (ADH) concentrations.Results: A statistically significant (p < 0.001) reduction in the mean weight of subjects occurred after dehydration. There was a significant reduction in IOP from 16.68 mmHg ± 0.32 mmHg to 13.08 mmHg ± 0.31 mmHg after dehydration (p < 0.001). Mean plasma osmolality showed a statistically significant increase (p < 0.05) from baseline of 290.02 mOsmol/kg ± 1.25 mOsmol/kg to 294.96 mOsmol/kg ± 1.33 mOsmol/kg after dehydration. There was also a significant increase (p < 0.05) in mean plasma ADH concentration from 5.36 pg/mL ± 0.21 pg/mL to 6.40 pg/mL ± 0.20 pg/mL after dehydration. There were no significant differences in both systolic and diastolic blood pressures before and after dehydration.Conclusion: Dehydration decreases IOP in healthy humans; this decrease probably results from an increase in plasma osmolality and plasma ADH concentrations.
The impact of shared domain knowledge on strategic information systems planning and alignment
Authors: Maharaj Simla , Brown Irwin
Published: July 2015

Background: Lack of alignment or harmony between information technology (IT) and business imperatives continues to plague organisations despite decades of research. Strategic information systems planning (SISP) is the process of coordinating the relationship between IT and the business in order to steer alignment. Shared domain knowledge (SDK) is a factor that is posited as important for improving both SISP and alignment, which is theorised to be the main outcome of SISP. Objectives: The aim of this article is to examine the impact of SDK on SISP and alignment. Method: Data were gathered from management consultants in a large, global IT organisation, through the use of a structured questionnaire, and analysed. Results: It was shown that SDK positively influences SISP characteristics and the alignment outcome. Specifically, it was found that high levels of rationality in SISP positively influenced the intellectual dimension of alignment, whilst IT manager participation in business planning influenced the social dimension of alignment. SDK was found to have a bearing on all of the SISP characteristics measured (i.e. rationality, adaptation, business planning-SISP integration and IT manager participation in business planning). SDK was also found to positively impact both the intellectual and social dimensions of alignment.Conclusion: The implications of the findings are that fostering a knowledge sharing environment in organisations will help improve alignment, as well as the formal processes designed to steer alignment such as SISP.
Primary versus secondary achalasia: New signs on barium esophagogram
Authors: Gupta Pankaj , Debi Uma , Sinha Saroj Kant , Prasad Kaushal Kishor
Published: July 2015

Aim: To investigate new signs on barium swallow that can differentiate primary from secondary achalasia. Materials and Methods: Records of 30 patients with primary achalasia and 17 patients with secondary achalasia were reviewed. Clinical, endoscopic, and manometric data was recorded. Barium esophagograms were evaluated for peristalsis and morphology of distal esophageal segment (length, symmetry, nodularity, shouldering, filling defects, and "tram-track sign"). Results: Mean age at presentation was 39 years in primary achalasia and 49 years in secondary achalasia. The mean duration of symptoms was 3.5 years in primary achalasia and 3 months in secondary achalasia. False-negative endoscopic results were noted in the first instance in five patients. In the secondary achalasia group, five patients had distal esophageal segment morphology indistinguishable from that of primary achalasia. None of the patients with primary achalasia and 35% patients with secondary achalasia had a length of the distal segment approaching combined height of two vertebral bodies. None of the patients with secondary achalasia and 34% patients with primary achalasia had maximum caliber of esophagus approaching combined height of two vertebral bodies. Tertiary contractions were noted in 90% patients with primary achalasia and 24% patients with secondary achalasia. Tram-track sign was found in 55% patients with primary achalasia. Filling defects in the distal esophageal segment were noted in 94% patients with secondary achalasia. Conclusion: Length of distal esophageal segment, tertiary contractions, tram-track sign, and filling defects in distal esophageal segment are useful esophagographic features distinguishing primary from secondary achalasia.
Pattern Recognition Receptors in Cancer Progression and Metastasis
Authors: Pandey Sanjay , Singh Saurabh , Anang Vandana , Bhatt Anant N. , Natarajan K. , Dwarakanath Bilikere S.
Published: July 2015

The innate immune system is an integral component of the inflammatory response to pathophysiological stimuli. Toll-like receptors (TLRs) and inflammasomes are the major sensors and pattern recognition receptors (PRRs) of the innate immune system that activate stimulus (signal)-specific proinflammatory responses. Chronic activation of PRRs has been found to be associated with the aggressiveness of various cancers and poor prognosis. Involvement of PRRs was earlier considered to be limited to infection- and injury-driven carcinogenesis, where they are activated by pathogenic ligands. With the recognition of damage-associated molecular patterns (DAMPs) as ligands of PRRs, the role of PRRs in carcinogenesis has also been implicated in other non-pathogen-driven neoplasms. Dying (apoptotic or necrotic) cells shed a plethora of DAMPs causing persistent activation of PRRs, leading to chronic inflammation and carcinogenesis. Such chronic activation of TLRs promotes tumor cell proliferation and enhances tumor cell invasion and metastasis by regulating pro-inflammatory cytokines, metalloproteinases, and integrins. Due to the decisive role of PRRs in carcinogenesis, targeting PRRs appears to be an effective cancer-preventive strategy. This review provides a brief account on the association of PRRs with various cancers and their role in carcinogenesis.
On the exactly synchronizable state to a coupled system of wave equations
Authors: Li Tatsien , Rao Bopeng
Published: July 2015

In this paper, we discuss the determination of the exactly synchronizable state to a coupled system of wave equations. In a special case, the exactly synchronizable state can be uniquely determined whatever the boundary controls would be chosen. In the general case, the determination of the exactly synchronizable state depends on the boundary controls which realize the exact synchronization, however, we can give an estimate to the difference between the exactly synchronizable state and the solution to a problem independent of boundary controls.
A note on two scale compactness for $p = 1$
Authors: Bufford Laura , Fonseca Irene
Published: July 2015

In this paper the notion of two-scale convergence introduced by G. Nguetseng and G. Allaire is extended to the case of bounded sequences in

L^1(\Omega)

, where

\Omega

is any open subset of

\mathbb{R}^N

. Three different approaches will be considered: an adaptation of the method used in

L^p(\Omega)

with

p>1

, a measure-theoretic argument, and the periodic unfolding technique.
A bound on the group velocity for Bloch wave packets
Authors: Allaire Grégoire , Palombaro Mariapia , Rauch Jeffrey
Published: July 2015

We give a direct proof that the group velocities of Bloch wave packet solutions of periodic second order wave equations cannot exceed the maximal speed of propagation of the periodic wave equation.
On the Cauchy problem for evolution $p(x)$-Laplace equation
Authors: Antontsev Stanislav , Shmarev Sergey
Published: July 2015

We consider the Cauchy problem for the equation

\text{$u_{t}-\operatorname{div} \left( a(x,t) |\nabla u|^{p(x)-2}\nabla u\right) =f(x,t)$ in $S_{T}=\mathbb{R}^{n}\times(0,T)$}

with measurable but possibly discontinuous variable exponent

p(x):\,\mathbb{R}^{n}\mapsto [p^-,p^+]\subset (1,\infty)

. It is shown that for every

u(x,0)\in L^{2}(\mathbb{R}^{n})

and

f\in L^{2}(S_T)

the problem has at least one weak solution

u\in C^{0}([0,T];L^{2} _{loc}(\mathbb{R}^{n}))\cap L^{2}(S_{T})

,

|\nabla u|^{p(x)}\in L^{1}(S_{T} )

. We derive sufficient conditions for global boundedness of weak solutions and show that the bounded weak solution is unique.
On the strong oscillatory behavior of all solutions to some second order evolution equations
Authors: Haraux Alain
Published: July 2015

Let

l

be any positive number. For any non-negative potential

p\in L^\infty (0, l)

, we show that for any solution

u

of

u_{tt} +u_{xxxx}+ p(x) u = 0

in

\mathbb R\times (0, l)

with

u = u_{xx} = 0

on

\mathbb R\times \{0, l\}

, and for any form

\zeta \in (H^2(0, l) \cap H^1_0(0, l))'

, the function

t\rightarrow \langle \zeta, u(t)\rangle

has a zero in each closed interval

I

of

\mathbb R

with length

|I|\ge \frac{\pi} {3} l^2

. A similar result of uniform oscillation property on each interval of length at least equal to

2l

is established for all weak solutions of the equation

u_{tt} - u_{xx}+ a(t) u = 0

in

\R\times (0, l)

with

u = 0

on

\R\times \{0, l\}

where

a

is a nonnegative essentially bounded coefficient. These results apply in particular to any finite linear combination of evaluations of the solution

u

at arbitrary points of

(0, l)

.
Existence and uniqueness results for the pressureless Euler–Poisson system in one spatial variable
Authors: LeFloch Philippe G. , Xiang Shuyang
Published: July 2015

We study the Euler-Poisson system describing the evolution of a fluid without pressure e¤ect and, more generally, also treat a class of nonlinear hyperbolic systems with an analogous structure. We investigate the initial value problem by generalizing a method first introduced by LeFloch in 1990 and based on Volpert’s product and Lax’s explicit formula for scalar conservation laws. We establish several existence and uniqueness results when one component of the system (the density) is measure-valued and the second one (the velocity) has bounded variation. Existence is proven for general initial data, while uniqueness is guaranteed only when the initial data does not generate rarefaction centers. Our proof proceeds by solving first a nonconservative version of the problem and constructing solutions with bounded variation, while the solutions of the Euler-Poisson system is then deduced by differentiation.
Estimation of continuous anthropogenic CO2 using CO2, CO, δ13C(CO2) and Δ14C(CO2)
Authors: Vardag S. N. , Gerbig C. , Janssens-Maenhout G. , Levin I.
Published: July 2015

Abstract. We investigate different methods for estimating anthropogenic CO2 using modelled continuous atmospheric concentrations of CO2 alone, as well as CO2 in combination with the surrogate tracers CO, δ13C(CO2) and Δ14C(CO2). These methods are applied at three hypothetical stations representing rural, urban and polluted conditions. We find that independent of the tracer used, an observation-based estimate of continuous anthropogenic CO2 is not feasible at rural measurement sites due to the low signal to noise ratio of anthropogenic CO2 estimates at such settings. At urban and polluted sites, potential future continuous Δ14C(CO2) measurements with a precision of 5 ‰ or better are most promising for anthropogenic CO2 determination (precision ca. 10–20%), but the insensitivity against CO2 contributions from biofuel emissions may reduce its accuracy in the future. Other tracers, such as δ13C(CO2) and CO could provide an accurate and already available alternative if all CO2 sources in the catchment area are well characterized with respect to their isotopic signature and CO to anthropogenic CO2 ratio. We suggest a strategy for calibrating these source characteristics on an annual basis using precise Δ14C(CO2) measurements on grab samples. The precision of anthropogenic CO2 determination using δ13C(CO2) is largely determined by the measurement precision of δ13C(CO2) and CO2. The precision when using the CO-method is mainly limited by the variation of natural CO sources and CO sinks. At present, continuous anthropogenic CO2 could be determined using the tracers δ13C(CO2) and/or CO with a precision of about 30 %, a mean bias of about 10 % and without significant diurnal discrepancies. This allows significant improvement, validation and bias reduction of highly resolved emission inventories using atmospheric observation and regional modelling.
Forty years of improvements in European air quality: the role of EU policy–industry interplay
Authors: Crippa M. , Janssens-Maenhout G. , Dentener F. , Guizzardi D. , Sindelarova K. , Muntean M. , Van Dingenen R. , Granier C.
Published: July 2015

Abstract. The EDGAR (Emissions Database for Global Atmospheric Research) v4.3 global anthropogenic emissions inventory of several gaseous (SO2, NOx, CO, non-methane volatile organic compounds (NMVOCs) and NH3) and particulate (PM10, PM2.5, black and organic carbon (BC and OC)) air pollutants for the period 1970–2010 is used to develop retrospective air pollution emission scenarios to quantify the roles and contributions of changes in fuels consumption, technology, end-of-pipe emission reduction measures and their resulting impact on health and crop yields. This database presents changes in activity data, fuels and air pollution abatement technology for the past 4 decades, using international statistics and following guidelines for bottom-up emission inventory at the Tier 1 and Tier 2 levels with region-specific default values. With two further retrospective scenarios we assess (1) the impact of the technology and end-of-pipe (EOP) reduction measures in the European Union (EU) by considering a stagnation of technology with constant emission factors from 1970 and with no further abatement measures and improvement in European emissions standards, but fuel consumption occurring at historical pace, and (2) the impact of increased fuel consumption by considering unchanged energy use with constant fuel consumption since 1970, but technological development and end-of-pipe reductions. Our scenario analysis focuses on the three most important and most regulated sectors (power generation, the manufacturing industry and road transport), which are subject of multi-pollutant EU Air Quality regulations. If technology and European EOP reduction measures had stagnated at 1970 levels, EU air quality in 2010 would have suffered from 129 % higher SO2, 71 % higher NOx and 69 % higher PM2.5 emissions, demonstrating the large role of technology in reducing emissions in 2010. However, if fuel consumption had remained constant starting in 1970, the EU would have benefited from current technology and emission control standards, with reductions in NOx by even 13 % more. Such further savings are not observed for SO2 and PM2.5. If the EU consumed the same amount of fuels as in 1970 but with the current technology and emission control standards, then the emissions of SO2 and PM2.5 would be 42 % respectively 10 % higher. This scenario shows the importance for air quality of abandoning heavy residual fuel oil and shifting fuel types (from, e.g., coal to gas) in the EU. A reduced-form TM5-FASST (Fast Screening Scenario Tool based on the global chemical Transport Model 5) is applied to calculate regional and global levels of aerosol and ozone concentrations and to assess the impact of air quality improvements on human health and crop yield loss, showing substantial impacts of export of EU technologies and standards to other world regions.
Change in turbopause altitude at 52 and 70° N
Authors: Hall C. M. , Holmen S. E. , Meek C. E. , Manson A. H. , Nozawa S.
Published: July 2015

Abstract. The turbopause is the demarkation between atmospheric mixing by turbulence (below) and molecular diffusion (above). When studying concentrations of trace species in the atmosphere, and particularly long-term change, it may be important to understand processes present, together with their temporal evolution, that may be responsible for redistribution of atmospheric constituents. The general region of transition between turbulent and molecular mixing coincides with the base of the ionosphere, the lower region in which molecular oxygen is dissociated, and, at high latitude in summer, the coldest part of the whole atmosphere. This study updates previous reports of turbopause altitude, extending the time series by half a decade, and thus shedding new light on the nature of change over solar-cycle timescales. Assuming there is no trend in temperature, at 70° N there is evidence for a summer trend of ~ 1.2 km decade−1, but for winter and at 52° N there is no significant evidence for change at all. If the temperature at 90 km is estimated using meteor trail data, it is possible to estimate a cooling rate, which, if applied to the turbopause altitude estimation, fails to alter the trend significantly irrespective of season. While studies of atomic oxygen density, [O], using mid-latitude timeseries dating from 1975, show positive trends which can be explained by a lowering of the turbopause, [O] exhibits negative trends since 2002 that, although at a different latitude, are compatible with the observed increase in turbopause height reported here.
Consistent satellite XCO2 retrievals from SCIAMACHY and GOSAT using the BESD algorithm
Authors: Heymann J. , Reuter M. , Hilker M. , Buchwitz M. , Schneising O. , Bovensmann H. , Burrows J. P. , Kuze A. , Suto H. , Deutscher N. M. , Dubey M. K. , Griffith D. W. T. , Hase F. , Kawakami S. , Kivi R. , Morino I. , Petri C. , Roehl C. , Schneider M. , Sherlock V. , Sussmann R. , Velazco V. A. , Warneke T. , Wunch D.
Published: July 2015

Abstract. Consistent and accurate long-term data sets of global atmospheric concentrations of carbon dioxide (CO2) are required for carbon cycle and climate-related research. However, global data sets based on satellite observations may suffer from inconsistencies originating from the use of products derived from different satellites as needed to cover a long enough time period. One reason for inconsistencies can be the use of different retrieval algorithms. We address this potential issue by applying the same algorithm, the Bremen Optimal Estimation DOAS (BESD) algorithm, to different satellite instruments, SCIAMACHY on-board ENVISAT (March 2002–April 2012) and TANSO-FTS on-board GOSAT (launched in January 2009), to retrieve XCO2, the column-averaged dry-air mole fraction of CO2. BESD has been initially developed for SCIAMACHY XCO2 retrievals. Here, we present the first detailed assessment of the new GOSAT BESD XCO2 product. GOSAT BESD XCO2 is a product generated and delivered to the MACC project for assimilation into ECMWF's Integrated Forecasting System. We describe the modifications of the BESD algorithm needed in order to retrieve XCO2 from GOSAT and present detailed comparisons with ground-based observations of XCO2 from the Total Carbon Column Observing Network (TCCON). We discuss detailed comparison results between all three XCO2 data sets (SCIAMACHY, GOSAT and TCCON). The comparison results demonstrate the good consistency between SCIAMACHY and GOSAT XCO2. For example, we found a mean difference for daily averages of −0.60 ± 1.56 ppm (mean difference ± standard deviation) for GOSAT–SCIAMACHY (linear correlation coefficient r=0.82), −0.34 ± 1.37 ppm (r = 0.86) for GOSAT–TCCON and 0.10 ± 1.79 ppm (r = 0.75) for SCIAMACHY–TCCON. The remaining differences between GOSAT and SCIAMACHY are likely due to non-perfect collocation (± 2 h, 10° x 10° around TCCON sites), i.e. the observed air masses are not exactly identical but likely also due to a still non-perfect BESD retrieval algorithm, which will be continuously improved in the future. Our overarching goal is to generate a satellite-derived XCO2 data set appropriate for climate and carbon cycle research covering the longest possible time period. We therefore also plan to extend the existing SCIAMACHY and GOSAT data set discussed here by also using data from other missions (e.g. OCO-2, GOSAT-2, CarbonSat) in the future.
Ionospheric correction of GPS radio occultation data in the troposphere
Authors: Zeng Z. , Sokolovskiy S. , Schreiner W. , Hunt D. , Lin J. , Kuo Y.-H.
Published: July 2015

Abstract. For inversions of the GPS radio occultation (RO) data in the neutral atmosphere, this study investigates an optimal transition height for replacing the standard ionospheric correction by the linear combination of the L1 and L2 bending angles with the correction of the L1 bending angle by the L1-L2 bending angle extrapolated from above. The optimal transition height depends on the RO mission (i.e., the receiver and firmware) and is different between rising and setting occultations and between L2P and L2C GPS signals. This height is within the range approximately 10–20 km. One fixed transition height, which can be used for the processing of currently available GPS RO data, can be set to 20 km. Analysis of the L1CA and the L2C bending angles in the presence of a sharp top of the boundary layer reveals differences that can be explained by shifts in the impact parameter. The ionosphere-induced vertical shifts of the bending angle profiles require further investigation.
Sources of dissolved organic matter during storm and inter-storm conditions in a lowland headwater catchment: constraints from high-frequency molecular data
Authors: Jeanneau L. , Denis M. , Pierson-Wickmann A.-C. , Gruau G. , Lambert T. , Petitjean P.
Published: July 2015

Abstract. The transfer of dissolved organic matter (DOM) at soil–river interfaces controls the biogeochemistry of micropollutants and the equilibrium between continental and oceanic C reservoirs. Understanding the mechanisms controlling this transfer is fundamental to ecology and geochemistry. DOM delivery to streams during storms is assumed to come from the flushing of preexisting soil DOM reservoirs mobilized by the modification of water flow paths. We tested this hypothesis by investigating the evolution of the composition of stream DOM during inter-storm conditions and five storm events monitored with high-frequency sampling. The composition of DOM was analyzed using thermally assisted hydrolysis and methylation (THM) with tetramethylammonium hydroxide (TMAH) coupled to a gas chromatograph and mass spectrometer. In inter-storm conditions, stream DOM is derived from the flushing of soil DOM, while during storm events, the modification of the distribution of chemical biomarkers allows the identification of three additional mechanisms. The first one corresponds to the destabilization of microbial biofilms due to the increase in water velocity, resulting in the fleeting export of a microbial pool. The second mechanism corresponds to the erosion of soils and river banks, leading to a partition of organic matter between particulate and dissolved phases. The third mechanism is linked to the increase in water velocity in soils that could induce the erosion of macropore walls, leading to an in-soil partition between soil microparticles and dissolved phase. The contribution of this in-soil erosive process would be linked to the magnitude of the hydraulic gradient following the rise of the water table and could persist after the recession, which could explain why the return to inter-storm composition of DOM does not follow the same temporal scheme as the discharge. These results are the most important factors in understanding the transfer of nutrients and micropollutants at the soil–river interfaces during the hot moments that are storm events.
Organically fertilized tea plantation stimulates N2O emissions and lowers NO fluxes in subtropical China
Authors: Yao Z. , Wei Y. , Liu C. , Zheng X. , Xie B.
Published: July 2015

Abstract. Tea plantations are rapidly expanding in China and other countries in the tropical and subtropical zones, but so far there are very few studies including direct measurements on nitrogenous gases fluxes from tea plantations. On the basis of 2 year field measurements from 2012 to 2014, we provided an insight into the assessment of annual nitrous oxide (N2O) and nitric oxide (NO) fluxes from Chinese subtropical tea plantations under three practices of conventional urea application, alternative oilcake incorporation and no nitrogen fertilization. Clearly, the N2O and NO fluxes exhibited large intra- and inter-annual variations, and furthermore their temporal variability could be well described by a combination of soil environmental factors including soil mineral N, water-filled pore space and temperature, based on a revised "hole-in-the-pipe" model. Averaged over 2 years, annual background N2O and NO emissions were approximately 4.0 and 1.6 kg N ha−1 yr−1, respectively. Compared to no nitrogen fertilization, both urea and oilcake application significantly stimulated annual N2O and NO emissions, amounting to 14.4–32.7 kg N2O-N ha−1 yr−1 and at least 12.3–19.4 kg NO-N ha−1 yr−1. In comparison with conventional urea treatment, on average, the application of organic fertilizer significantly increased N2O emission by 71 % but decreased NO emission by 22 %. Although the magnitude of N2O and NO fluxes was substantially influenced by N source, the annual direct emission factors of fertilizer N were estimated to be 2.8–5.9, 2.7–4.0 and 6.8–9.1 % for N2O, NO and N2O + NO, respectively, which are significantly higher than those defaults for global upland croplands. This indicated that the rarely determined N2O and NO formation appeared to be a significant pathway in the nitrogen cycle of tea plantations, which are a potential source of national nitrogenous gases inventory.
Modern to millennium-old greenhouse gases emitted from freshwater ecosystems of the eastern Canadian Arctic
Authors: Bouchard F. , Laurion I. , Preskienis V. , Fortier D. , Xu X. , Whiticar M. J.
Published: July 2015

Abstract. Ponds and lakes are widespread across the rapidly changing permafrost environments. Aquatic systems play an important role in global biogeochemical cycles, especially in greenhouse gas (GHG) exchanges between terrestrial systems and the atmosphere. The source, speciation and emission of carbon released from permafrost landscapes are strongly influenced by local specific conditions rather than general environmental setting. This study reports on GHG ages and emission rates from aquatic systems on Bylot Island in the eastern Canadian Arctic. Dissolved and ebullition gas samples were collected during the summer season from different types of water bodies located in a highly dynamic periglacial valley: polygonal ponds, collapsed ice-wedge trough ponds, and larger lakes overlying unfrozen soils (talik). The results showed strikingly different ages and fluxes depending on aquatic system types. Polygonal ponds were net sinks of dissolved CO2, but variable sources of dissolved CH4. They presented the highest ebullition fluxes, one or two orders of magnitude higher than from other ponds and lakes. Trough ponds appeared as substantial GHG sources, especially when their edges were actively eroding. Both types of ponds produced modern to hundreds of years old (<550 yr BP) GHG, even if trough ponds could contain much older carbon (>2000 yr BP) derived from freshly eroded peat. Lakes had small dissolved and ebullition fluxes, however they released much older GHG, including millennium-old CH4 (up to 3500 yr BP) sampled from lake central areas. Acetoclastic methanogenesis dominated at all study sites and there was minimal, if any, methane oxidation in gas emitted through ebullition. These findings provide new insights on the variable role of permafrost aquatic systems as a positive feedback mechanism on climate.
EMPOWER-1.0: an Efficient Model of Planktonic ecOsystems WrittEn in R
Authors: Anderson T. R. , Gentleman W. C. , Yool A.
Published: July 2015

Abstract. Modelling marine ecosystems requires insight and judgement when it comes to deciding upon appropriate model structure, equations and parameterisation. Many processes are relatively poorly understood and tough decisions must be made as to how to mathematically simplify the real world. Here, we present an efficient plankton modelling testbed, EMPOWER-1.0 (Efficient Model of Planktonic ecOsystems WrittEn in R), coded in the freely available language R. The testbed uses simple two-layer "slab" physics whereby a seasonally varying mixed layer which contains the planktonic marine ecosystem is positioned above a deep layer that contains only nutrient. As such, EMPOWER-1.0 provides a readily available and easy to use tool for evaluating model structure, formulations and parameterisation. The code is transparent and modular such that modifications and changes to model formulation are easily implemented allowing users to investigate and familiarise themselves with the inner workings of their models. It can be used either for preliminary model testing to set the stage for further work, e.g. coupling the ecosystem model to 1-D or 3-D physics, or for undertaking front line research in its own right. EMPOWER-1.0 also serves as an ideal teaching tool. In order to demonstrate the utility of EMPOWER-1.0, we implemented a simple nutrient–phytoplankton–zooplankton–detritus (NPZD) ecosystem model and carried out both a parameter tuning exercise and structural sensitivity analysis. Parameter tuning was demonstrated for four contrasting ocean sites, focusing on station BIOTRANS in the North Atlantic (47° N, 20° W), highlighting both the utility of undertaking a planned sensitivity analysis for this purpose, yet also the subjectivity which nevertheless surrounds the choice of which parameters to tune. Structural sensitivity tests were then performed comparing different equations for calculating daily depth-integrated photosynthesis, as well as mortality terms for both phytoplankton and zooplankton. Regarding the calculation of daily photosynthesis, for example, results indicated that the model was relatively insensitive to the choice of photosynthesis–irradiance curve, but markedly sensitive to the method of calculating light attenuation in the water column. The work highlights the utility of EMPOWER-1.0 as a means of comprehending, diagnosing and formulating equations for the dynamics of marine ecosystems.
Impacts of climate change on temperature, precipitation and hydrology in Finland – studies using bias corrected Regional Climate Model data
Authors: Olsson T. , Jakkila J. , Veijalainen N. , Backman L. , Kaurola J. , Vehviläinen B.
Published: July 2015

Abstract. Assessment of climate change impacts on climate and hydrology on catchment scale requires reliable information about the average values and climate fluctuations of the past, present and future. Regional climate models (RCMs) used in impact studies often produce biased time series of meteorological variables. In this study bias correction (BC) of RCM temperature and precipitation for Finland is carried out using different versions of the distribution based scaling (DBS) method. The DBS-adjusted RCM data are used as input of a hydrological model to simulate changes in discharges of four study catchments in different parts of Finland. The annual mean discharges and seasonal variation simulated with the DBS-adjusted temperature and precipitation data are sufficiently close to observed discharges in the control period 1961–2000 and produce more realistic projections for mean annual and seasonal changes in discharges than the uncorrected RCM data. Furthermore, with most scenarios the DBS method used preserves the temperature and precipitation trends of the uncorrected RCM data during 1961–2100. However, if the biases in the mean or the standard deviation of the uncorrected temperatures are large, significant biases after DBS adjustment may remain or temperature trends may change, increasing the uncertainty of climate change projections. The DBS method influences especially the projected seasonal changes in discharges and the use of uncorrected data can produce unrealistic seasonal discharges and changes. The projected changes in annual mean discharges are moderate or small, but seasonal distribution of discharges will change significantly.
Flood and drought hydrologic monitoring: the role of model parameter uncertainty
Authors: Chaney N. W. , Herman J. D. , Reed P. M. , Wood E. F.
Published: July 2015

Abstract. Land surface modeling, in conjunction with numerical weather forecasting and satellite remote sensing, is playing an increasing role in global monitoring and prediction of extreme hydrologic events (i.e., floods and droughts). However, uncertainties in the meteorological forcings, model structure, and parameter identifiability limit the reliability of model predictions. This study focuses on the latter by assessing two potential weaknesses that emerge due to limitations in our global runoff observations: (1) the limits of identifying model parameters at coarser timescales than those at which the extreme events occur, and (2) the negative impacts of not properly accounting for model parameter equifinality in the predictions of extreme events. To address these challenges, petascale parallel computing is used to perform the first global-scale, 10 000 member ensemble-based evaluation of plausible model parameters using the VIC (Variable Infiltration Capacity) land surface model, aiming to characterize the impact of parameter identifiability on the uncertainty in flood and drought predictions. Additionally, VIC's global-scale parametric sensitivities are assessed at the annual, monthly, and daily timescales to determine whether coarse-timescale observations can properly constrain extreme events. Global and climate type results indicate that parameter uncertainty remains an important concern for predicting extreme events even after applying monthly and annual constraints to the ensemble, suggesting a need for improved prior distributions of the model parameters as well as improved observations. This study contributes a comprehensive evaluation of land surface modeling for global flood and drought monitoring and suggests paths forward to overcome the challenges posed by parameter uncertainty.