bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of usability in e-lexicography
Authors: Du Plessis André H.
Published: May 2017

In the development of the metalexicography, the primary focus of metalexicographers was on the development of printed dictionaries. As technology advances, the focus now shifts towards online and electronic products. Tarp (2009:23–24) posits that this shift results in metalexicographic shortcomings. This means that the theories used to create and evaluate dictionaries are not sufficient anymore. Bergenholtz and Bothma (2011:54) show that dictionaries as data carriers are now not only limited to the field of lexicography, but also to information technological fields. For current lexicographers to be successful in the digital age, the theories used in designing, developing and critiquing dictionaries must adapt with regards to current information technological trends, norms and practices. One aspect that must be addressed is the usability of dictionaries and other electronic lexicographic tools. By using usability theories and standards, current metalexicographical principles can be adapted for the digital age in a streamlined fashion. This study aims to show how usability theories and standards can be advantageous for metalexicography and that future electronic metalexicographic endeavours should not be undertaken without considering the usability as part of the theoretical framework.
Trust of community health workers influences the acceptance of community-based maternal and child health services
Authors: Grant Merridy , Wilford Aurene , Haskins Lyn , Phakathi Sifiso , Mntambo Ntokozo , Horwood Christiane M.
Published: May 2017

Background: Community health workers (CHWs) are a component of the health system in many countries, providing effective community-based services to mothers and infants. However, implementation of CHW programmes at scale has been challenging in many settings.Aim: To explore the acceptability of CHWs conducting household visits to mothers and infants during pregnancy and after delivery, from the perspective of community members, professional nurses and CHWs themselves.Setting: Primary health care clinics in five rural districts in KwaZulu-Natal, South Africa.Methods: A qualitative exploratory study was conducted where participants were purposively selected to participate in 19 focus group discussions based on their experience with CHWs or child rearing.Results: Poor confidentiality and trust emerged as key barriers to CHW acceptability in delivering maternal and child health services in the home. Most community members felt that CHWs could not be trusted because of their lack of professionalism and inability to maintain confidentiality. Familiarity and the complex relationships between household members and CHWs caused difficulties in developing and maintaining a relationship of trust, particularly in high HIV prevalence settings. Professional staff at the clinic were crucial in supporting the CHW’s role; if they appeared to question the CHW’s competency or trustworthiness, this seriously undermined CHW credibility in the eyes of the community.Conclusion: Understanding the complex contextual challenges faced by CHWs and community members can strengthen community-based interventions. CHWs require training, support and supervision to develop competencies navigating complex relationships within the community and the health system to provide effective care in communities.
To what extent does access to improved sanitation explain the observed differences in infant mortality in Africa?
Authors: Alemu Aye M.
Published: May 2017

Background: To my knowledge, there was no systematic study so far that analysed the extent of the impact of improved sanitation on infant mortality in the African context with long years of full-fledged longitudinal data.Aim: The aim of this study was to empirically examine the extent to which improved sanitation explains the observed differences in infant mortality under 5 years of age across African countries.Setting: The study covered a panel of 33 countries from north, south, east, west and central Africa for the years 1994–2013.Methods: The study first conducted Durbin–Wu–Hausman specification test and then used fixed effect model. In addition, Praison–Winsten regression with corrected heteroscedasticity was employed to verify the consistency of the results that were revealed in using fixed effect estimation method.Results: The study revealed that a 1% increase in access to improved sanitation would reduce infant mortality by a rate of about two infant deaths per 1000 live births. Also, the study confirmed that a significant decline in infant mortality rate was highly linked to improvements in education, health and sustainable economic growth.Conclusion: The findings have wide implications especially for African countries for which decreasing infant mortality is one of the most crucial priorities in the continent to reverse the current deep-rooted challenges related to human capital formation.
Palliative care needs of patients living with end-stage kidney disease not treated with renal replacement therapy: An exploratory qualitative study from Blantyre, Malawi
Authors: Bates Maya J. , Chitani Alex , Dreyer Gavin
Published: May 2017

Background: The burden of end-stage kidney disease (ESKD) in sub-Saharan Africa is increasing rapidly but the palliative care needs of patients living with ESKD are not well described. Resource limitations at both health system and patient level act as major barriers to patients receiving renal replacement therapy (RRT) in the form of dialysis. We undertook an exploratory qualitative study to describe the palliative care needs of patients with ESKD who were not receiving RRT, at a government teaching hospital in Blantyre, Malawi.Methods: A qualitative, explorative and descriptive design was used. Study participants were adults aged > 18 years with an estimated glomerular filtration rate < 15 ml/min on two separate occasions, three months apart, who either chose not to have or were not deemed suitable for RRT. Data were collected by means of semi-structured interviews.Results: In October and November 2013, interviews were conducted with 10 adults (7 women with median age of 60.5 years). All were hypertensive and four were on treatment for HIV. Four themes emerged from the data: changes in functional status because of physical symptoms, financial challenges impacting hospital care, loss of role within the family and the importance of spiritual and cultural beliefs.Conclusion: This study reports on four thematic areas which warrant further quantitative and qualitative studies both in Malawi and other low-resource settings, where a growing number of patients with ESKD unable to access RRT will require palliative care in the coming years.
Factors influencing managers’ attitudes towards performance appraisal
Authors: Du Plessis Tanya , Van Niekerk Annelize
Published: May 2017

Orientation: Managers often have negative attitudes towards performance appraisal because of its problematic nature, which is influenced by political and social contextual factors. These negative attitudes lead to reduced employee support, inaccurate performance appraisal ratings and, consequently, negative employee perceptions of the performance appraisal process. This state of affairs necessitates a deeper understanding of the factors influencing managers’ attitudes towards performance appraisal.Research purpose: The purpose of this research was to gain a deeper understanding of the factors that influence managers’ attitudes towards performance appraisal.Motivation for the study: Previous research has confirmed the importance of performance appraisals in organisations. However, managers’ dislike of and aversion to performance appraisal impact negatively on the effectiveness of performance appraisal systems and ultimately the development and performance of employees.Research design, approach and method: An interpretivist qualitative study was adopted, utilising naïve sketches and in-depth interviews to collect data from eight managers, purposively selected. The data were analysed by using Tesch’s descriptive data analysis technique.Main findings: This study revealed that performance appraisal is fundamentally an uncomfortable and emotional process for managers, which results in their adopting defensive attitudes. Because of many uncertainties, managers do not always display the ability or readiness to conduct performance appraisals. The organisational context might place the individual manager in a position to distort employee ratings, which in turn negatively influences that manager’s attitude.Practical and managerial implications: This study provides insight into the present-day experience of managers in respect of performance appraisal and highlights the factors that influence their attitudes.Contribution: The insight gained from this research into the factors impacting on the attitude of managers towards performance appraisals can assist organisations to better support and empower such managers to be more effective in their approach when conducting performance appraisals.
Skeletal and Dentoalveolar Changes after Skeletal Anchorage-assisted Rapid Palatal Expansion in Young Adults: A Cone Beam Computed Tomography Study
Authors: Clement Evan. A. , Krishnaswamy N. R.
Published: May 2017

Objective

The aim of this study was to evaluate skeletal and dentoalveolar changes before and after skeletal anchorage-assisted rapid palatal expansion in young adults by cone beam computed tomography.

Materials and Methods

This pilot study included ten patients with a mean age of 21.5 years with maxillary transverse deficiency treated with the skeletal expander. Three dimensional evaluation of the changes before and after expansion was evaluated with Cone Beam CT. Statistical analysis was performed using paired t-test.

Results

Skeletal expander produced an increase in maxillary transverse dimension at the skeletal, alveolar, and dental level. The maximum expansion was at the level of dentition, and the least amount of expansion was at the level of the frontonasal suture. There was also evidence of sutural divergence and buccal tipping.

Conclusion

The maxillary skeletal expander is an effective method for correction of maxillary transverse deficiency without surgery in adults.
The Comparison of Patient Satisfaction after “Surgery First” and Conventional Orthognathic Surgery: An Original Research
Authors: Mohanty Pritam , Acharya Swati Saraswata , Sahoo Nivedita , Sah Sushila , Sahu Sanjeeb Kumar
Published: May 2017

Aims and Objectives

We evaluated the factors which affect patient satisfaction and their expectations toward “surgery first” and conventional orthognathic surgery.

Materials and Methods

Questionnaires consisting of 17 questions were given to the subjects postoperatively who had undergone Le fort 1 maxillary superior impaction for skeletal gummy smile correction with conventional orthognathic surgery and “surgery first” approach. Eleven-point rating scale based on a (visual analog scale; 0 = poor; 10 = excellent) were used to answer six questions. Ten closed-form questions were also included as well as one open question for “further remarks.”

Results

Nineteen patients (12 females, 07 males; mean age, 23.4 ± 4.9 [standard deviation] years) gave their consent to participate in the study. The intention to undergo surgery only for esthetics was noted in 42.11% of patients; only improvement of chewing function in 21.05% and both in 36.84%.

Conclusion

The most common factor for patient satisfaction after “surgery first” and conventional orthognathic surgery was facial esthetics, but masticatory function and even psychological aspects should be considered equally when planning surgery. The patient satisfaction was more in “surgery first” than conventional orthognathic surgery. The timing of treatment and immediate results are important factors toward patient satisfaction.
Cephalometric Profile of Bangladeshis: Tweed’s Analysis
Authors: Rizvi Hasan Md , Hossain Md Zakir
Published: May 2017

Introduction

Tweed’s diagnostic triangle is simple yet provides a definite guideline in treatment planning. The aim of the present study was to establish the Tweed’s norms for Bangladeshi people.

Methods

The study was conducted for 89 Bangladeshi young adults (45 males and 44 females), aged 19–27 years, having balanced and harmonious facial profiles. Lateral cephalograms taken of these subjects were used for a series of morphometric analyses.

Results

All three angular parameters Frankfort-mandibular plane angle (FMA), Frankfort-mandibular incisal angle (FMIA), incise mandibular plane angle (IMPA)were measured and found to be 24.52°, 54.60°, and 100.88°, respectively. The mean FMA has been found to be 24.52° (with a range of 14°–36°) which is quite close to Tweed’s norm and found to be statistically insignificant. However, IMPA and FMIA values of Bangladeshis found to be statistically significantly different from that of the Caucasians. The linear regression equation of IMPA on FMA was fitted, and the estimated value of IMPA was computed for a given FMA.

Conclusion

The results support the idea that treatment objectives of IMPA should be considered according to the facial pattern, i.e., FMA. Ethnic variations of norms cannot be overlooked while outlining goals and planning the treatment.
Comparison between Still Photography and Videography for Smile Analysis
Authors: Chaudhary Jyoti , Agarkar Sanket , Manerikar Ravindra , Rahalkar Jayesh
Published: May 2017

Introduction

The aim of this systematic review was to compare still photography and videography for smile analysis.

Materials and Methods

Based on the available data, two authors conducted an electronic database PubMed search from January 1, 2000, to December 31, 2015, and ten strategies were designed using five keywords along with their respective synonyms. Twelve articles were shortlisted for the systematic review.

Results

The search yielded 91 articles, of which 12 were included based on the selection criteria. Of these 12, five concluded videography compared to be a better tool. Seven articles had variable conclusions based on the study setting and population evaluated.

Conclusions

Digital video clips offer a tremendous amount of information for analyzing the dynamic character of the smile, but a standard digital photograph allows for immediate viewing.
Potential biomarkers for bipolar disorder
Authors: Sagar Rajesh , Pattanayak Raman Deep
Published: May 2017

Bipolar disorder (BD) is a severe, recurrent mood disorder, associated with a significant morbidity and mortality, with high rates of suicides and medical comorbidities. There is a high risk of mood disorders among the first-degree relatives of patients with BD. In the current clinical practice, the diagnosis of BD is made by history taking, interview and behavioural observations, thereby lacking an objective, biological validation. This approach may result in underdiagnosis, misdiagnosis and eventually poorer outcomes. Due to the heterogeneity of BD, the possibility of developing a single, specific biomarker is still remote; however, there is a set of promising biomarkers which may serve as predictive, prognostic or treatment markers in the future. The review presents a critical appraisal and update on some of the most promising candidates for biomarkers, namely, neuroimaging markers, peripheral biomarkers and genetic markers, including a brief discussion on cognitive endophenotypes as indicative of genetic risk. The lessons learnt from other fields and specialties in medicine need to be applied to psychiatry to translate the knowledge from ‘bench to bedside’ by means of clinically useful biomarkers. Overall, the biomarkers may help in pushing the shift towards personalized medicine for psychiatric patients.
Identifying the risk of producing aneuploids using meiotic recombination genes as biomarkers
Authors: Suresh Raviraj V. , Lingaiah Kusuma , Veerappa Avinash M. , Ramachandra Nallur B.
Published: May 2017

Background & objectives:

Aneuploids are the most common chromosomal abnormality in liveborns and are usually the result of non-disjunction (NDJ) in meiosis. Copy number variations (CNVs) are large structural variations affecting the human genome. CNVs influence critical genes involved in causing NDJ by altering their copy number which affects the clinical outcome. In this study influence of CNVs on critical meiotic recombination was examined using new computational technologies to assess their role in causing aneuploidy.

Methods:

This investigation was based on the analysis of 12 random normal populations consisting of 1714 individuals for aneuploid causing genes under CNV effect. To examine the effect of CNVs on genes causing aneuploidy, meiotic recombination genes were analyzed using EnrichR, WebGestalt and Ingenuity Pathway Analysis (IPA).

Results:

Forty three NDJ genes were found under CNV burden; IPA (Ingenuity Pathway Analysis) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis of CNV in meiotic recombination genes revealed a significant role of breast cancer gene 1, amyloid protein precursor, mitogen-activated protein kinase and nerve growth factor as key molecular players involved in causing aneuploidy. Interaction between these genes with other CNV-overlapping genes involved in cell cycle, recombination and meiosis might lead to increased incidences of aneuploidy.

Interpretation & conclusions:

The findings of this study implied that the effect of CNVs on normal genome contributed in amplifying the occurrences of chromosomal aneuploidies. The normal individuals consisting of variations in the susceptible genes causing aneuploids in the population remain undetected until the disorder genes express in the succeeding generations.
Root polytopes, parking functions, and the HOMFLY polynomial
Authors: Kálmán Tamás , Murakami Hitoshi
Published: May 2017

We show that for a special alternating link diagram, the following three polynomials are essentially the same: a) the part of the HOMFLY polynomial that corresponds to the leading term in the Alexander polynomial; b) the

h

-vector for a triangulation of the root polytope of the Seifert graph and c) the enumerator of parking functions for the planar dual of the Seifert graph. These observations yield formulas for the maximal

z

-degree part of the HOMFLY polynomial of an arbitrary homogeneous link as well. Our result is part of a program aimed at reading HOMFLY coefficients out of Floer homology.
Shadows, ribbon surfaces, and quantum invariants
Authors: Carrega Alessio , Martelli Bruno
Published: May 2017

Eisermann has shown that the Jones polynomial of a

n

-component ribbon link

L\subset S^3

is divided by the Jones polynomial of the trivial

n

-component link. We improve this theorem by extending its range of application from links in

S^3

to colored knotted trivalent graphs in

\#_g(S^2\times S^1)

, the connected sum of

g\geqslant 0

copies of

S^2\times S^1

.

We show in particular that if the Kauffman bracket of a knot in

\#_g(S^2\times S^1)

has a pole in

q=i

of order

n

, the ribbon genus of the knot is at least

\frac {n+1}2

. We construct some families of knots in

\#_g(S^2\times S^1)

for which this lower bound is sharp and arbitrarily big. We prove these estimates using Turaev shadows.
Galois action on knots I: Action of the absolute Galois group
Authors: Furusho Hidekazu
Published: May 2017

Our aim of this and subsequent papers is to enlighten (a part of, presumably) arithmetic structures of knots. This paper introduces a notion of profinite knots which extends topological knots and shows its various basic properties. Particularly an action of the absolute Galois group of the rational number field on profinite knotsis rigorously established, which is attained by our extending the action of Drinfeld's Grothendieck–Teichmüller group on profinite braid groups into on profinite knots.
Design and fabrication of an automatic dual axis solar tracker by using LDR sensors
Authors: Sharma Abhisak , Sharma Chahak
Published: May 2017

Due to the rotation of the earth in an orbit, direction of the Sun changes relatively. This paper represents a setup, which is fabricated to minimize the angle of incidence between incoming light from Sun and a flat photovoltaic (PV) panel to increase the intensity of the light received. It increases the power generated by an installed power generating unit. This setup consists of a mechanical mechanism to tilt the flat PV panel towards the Sun. This mechanism is derived by DC motors having a high reduction ratio. Voltage supplies to these motors are controlled by the LDR (Light Dependent Registers) sensors by the means of electronic circuits. The energy consumed by the tracking system is very less. The cost of the mechanical parts and electronic components are very less. The Microprocessor is not used in this setup. Hence it does not require programming and computer interface. Not any geological data are required, because LDRs work on the differential of the light intensity at the both ends of the plate. The motive of the work is to fabricate a solar tracker at a very low cost.Keywords: Solar Tracker, LDR, Photovoltaic (PV) cell, Dual Axis, Solar Collectors, Solar power plant
Parenthood and Partnerhood in the Context of Involuntary Childlessness and Assisted Reproduction in Greece
Authors: Chatjouli Aglaia , Daskalaki Ivi , Kantsa Venetia
Published: May 2017

Ta en oiko mi en dimo is a popular Greek proverb meaning that whatever happens at household [ oikos] should not be exposed into public [ dimos]. In the Greek cultural context sexuality, reproduction, family relations belong to the realm of private domesticity. In this paper we trace the way women and men in Greece resituate themselves towards their reproductive desires and decisions, towards medicalized reproduction and towards each other, when in the context of involuntary childlessness, infertility and ART use, reproduction moves outside the body and the private sphere of the household and becomes part of the public sphere exemplified in state laws, doctor's decisions, hospital laboratories, IVF forums.

Drawing from the research project (In)FERCIT and based on 130 semi-structured interviews of both women and men the paper explores the shifts related to parenting, the imagining and making of a family, the couple, in the context of neoliberal reproductive potentialities. Which relationships and practices change through the ongoing challenges of infertility and the experience of ART? What is kept within the couple and what is shared with others (family members, friends, strangers, experts)? What is the significance of reproductive socialities in managing the demands of infertility within an ever-increasing intensification of parenthood? How does this challenging context reinforces or weakens the couple's relationship, their reproductive agency and desire? Finally we explore how proper parenthood but also proper partnerhood are constructed in Greece following local demands regarding family making and localized medicalization of reproduction.
The Contribution of Mothers’ Employment on Their Family's Chances of Ending Welfare Benefit Receipt in Germany. Analysis of a Two-Stage Process
Authors: Lietzmann Torsten
Published: May 2017

The following article investigates to what extent individual employment of mothers contributes to ending receipt of welfare benefits in Germany. It disentangles the process of an employment-related exit into two stages: first, the process of taking up employment and second, the probability of ending benefit receipt with this new employment. This analysis focuses on mothers because they face particular restrictions on their labour market behaviour. It identifies the determinants involved using event history and probit models on the basis of longitudinal administrative data on benefit receipt and employment. Whereas the time and effort spent on childcare based on the age of the youngest child only influences the taking up of employment, household size plays a role only for the probability of ending benefit receipt. The individual labour market resources of the mothers influence access to the labour market, whereas for exits from benefit receipt the job position and type of employment relationship are more decisive.
Network Composition, Individual Social Capital and Culture: Comparing Traditional and Post-Modernized Cultures
Authors: Häuberer Julia , Tatarko Alexander
Published: May 2017

This article addresses the influence of cultural background on the access to social capital in family and friendship networks. We will analyze four different culture groups: Czechs and Russians (Muscovites) both representing post-modernized cultures and Dagestans and Chechens both representing traditional cultures. The data will be analyzed using univariate comparisons and fixed effects regressions. Our results indicate that cultural background does not play such a crucial role for social network composition and social capital access through the family or friends. In both cases, Dagestans, Chechens and Czechs access significantly less social capital than do the Russians (Muscovites), however only if Russians (Muscovites) are in frequent contact with their families or have large friendship networks. In other words, network embeddedness seems to play a more important role than cultural background for social capital access.
Friendship, Gender and Sexual Experience: Retrospective Narratives about the Formation of a Sexual Self during Youth
Authors: Policarpo Verónica
Published: May 2017

In this article, I explore the ways in which friendship contributes to shaping the boundaries of men's and women's sexual experiences. Using inputs from the sociology of experience and the sociology of friendship, I explore qualitative data from a research about sexuality in Portugal, in which I collected sexual biographies of 35 men and women, aged 30-55. In the in-depth interviews, these adult participants, possessing secondary and tertiary education, and living in urban areas, reflected retrospectively about their sexual biography, including their childhood and youth. The main thesis is that the practices of friendship (which structure those relationships as social facts) also help to structure sexual practices and representations and, through them, to construct the contemporary sexual self. Those practices may be discursive (‘talking’ and ‘chatting’), or rather oriented to action (‘doing things together’). In this article, I focus on discursive friendship practices, and how they contribute to shaping contemporary sexual experience. Drawing on F. Dubet's sociology of experience, I argue that this relationship is defined in the tension along three dimensions: integration, strategy and subjectivation. This process is cross-cut by gender, as discursive friendship practices interact differently with the dimensions of sexual experience, in that strategy mainly reinforces definitions and enactment of hegemonic forms of masculinity, while subjectivation helps to challenge them and to build plural gender experiences (both feminine and masculine).
Doing Gender in a Hospital Setting: Reflections of a Male Researcher
Authors: Thomas Gareth M.
Published: May 2017

Very little attention has been afforded to how male researchers actively position their gender in their studies, particularly in ethnographic research located within settings populated largely by women. In this article, I reflect on my own gender work during an ethnography of prenatal clinics and how this was articulated with other aspects of my researcher self. By reporting on the successes and failures of this performance, I argue that my gender constituted an essential element in the everyday negotiations between myself and female participants. In so doing, I suggest that reflexive commentaries of how researchers perform gender should not be viewed as a form of egotistic self-indulgence. Rather, they should be read as valuable statements for rendering the researcher visible and, here, for revealing how issues of doing gender play out during fieldwork.
Affective De-Commodifying, Economic De-Kinning: Surrogates’ and Gay Fathers’ Narratives in U.S. Surrogacy
Authors: Smietana Marcin
Published: May 2017

In this paper I discuss affective and economic exchanges in commercial surrogacy in the US. I draw on a qualitative study I carried out in the US between 2014 and 2016, consisting of interviews and participant observation with 37 gay fathers in 20 families, 20 surrogates and 15 professionals. My findings suggest that emotions and affects, present in the dominant narrative of gift-giving and relatedness between surrogates and gay fathers, facilitate commodification. At the same time, I argue that emotions and affects render the effects of commodification more bearable for surrogates and intended parents, as they diminish their mutual estrangement and the surrogates’ alienation from the product of their labour. On the other hand, I show how the affective processes work simultaneously with economic dimensions of making kinship. The negotiation of kinship is facilitated by economics, as compensation that surrogates receive contributes to de-kinning their parenting status and cementing the intended fathers’ rights. According to my data, the exchange between surrogates and intended fathers in the US is founded on the women's lower socio-economic status. This stratified exchange, however, occurs mainly within the middle class between relatively economically empowered individuals, which is underpinned by a normative expectation of surrogates’ agency and self-determination. Throughout this paper I aim to show that affective and economic exchanges I observed in US surrogacy mutually reinforce each other.
Modelling organic aerosol concentrations and properties during ChArMEx summer campaigns of 2012 and 2013 in the western Mediterranean region
Authors: Chrit Mounir , Sartelet Karine , Sciare Jean , Pey Jorge , Marchand Nicolas , Couvidat Florian , Sellegri Karine , Beekmann Matthias
Published: May 2017

Abstract. In the framework of the Chemistry-Aerosol Mediterranean Experiment, a measurement site was set up at a remote site (Ersa) on Corsica Island in the northwestern Mediterranean Sea. Measurement campaigns performed during the summers of 2012 and 2013 showed high organic aerosol concentrations, mostly from biogenic origin. This work aims at representing the organic aerosol concentrations and properties (oxidation state and hydrophilic) using the air-quality model Polyphemus with a surrogate approach for secondary organic aerosol (SOA) formation. Biogenic precursors are isoprene, monoterpenes (with α-pinene and limonene as surrogate species) and sesquiterpenes. In this work, the following model oxidation products of monoterpenes are added: (i) a carboxylic acid (MBTCA) to represent multi-generation oxidation products in the low-NOx regime, (ii) organic nitrate chemistry, (iii) extremely low volatility organic compounds (ELVOCs) formed by ozonolysis. The model shows good agreement to measurements of organic concentrations for both 2012 and 2013 summer campaigns. The modeled oxidation state and hydrophilic properties of the organic aerosols also agree reasonably well with the measurements. The influence of the different chemical processes added to the model on the oxidation level of organics is studied. Measured and simulated water-soluble organic concentrations (WSOC) show that even at a remote site next to the sea, about 64 % of the organic carbon is soluble. The concentrations of WSOC vary with the origins of the air masses and the composition of organic aerosols. The marine organic emissions only contribute to a few percents of the organic mass in PM1, with maxima above the sea.
The influence of mid-latitude cyclones on European background surface ozone
Authors: Knowland K. Emma , Doherty Ruth M. , Hodges Kevin I. , Ott Lesley E.
Published: May 2017

Abstract. The relationship between springtime mid-latitude cyclones and background ozone (O3) is explored using a combination of observational and reanalysis data sets. First, the relationship between surface O3 observations at two rural monitoring sites on the west coast of Europe – Mace Head, Ireland and Monte Velho, Portugal – and cyclone track frequency in the surrounding regions is examined. Second, detailed case study examination of four individual mid-latitude cyclones and the influence of the associated frontal passage on surface O3 is performed. Cyclone tracks have a greater influence on the O3 measurements at the more northern coastal European station, Mace Head, located within the main North Atlantic (NA) storm track. In particular, when cyclones track north of 53° N, there is a significant relationship with high levels of surface O3 (> 75th percentile). The further away a cyclone is from the NA storm track, the more likely it will be associated with both high and low (
Gaseous elemental mercury (GEM) fluxes over canopy of two typical subtropical forests in south China
Authors: Yu Qian , Luo Yao , Wang Shuxiao , Wang Zhiqi , Hao Jiming , Duan Lei
Published: May 2017

Abstract. Mercury (Hg) exchange between forests and the atmosphere plays an important role in global Hg cycling. The present estimate of global emission of Hg from natural source has large uncertainty partly due to the lack of chronical and valid field data, particularly for terrestrial surfaces in China, the most important contributor to global atmospheric Hg. In this study, micrometeorological method (MM) was used to continuously observe gaseous elemental mercury (GEM) fluxes over forest canopy at a clean site (Qianyanzhou, QYZ) and a contaminated site (Huitong, HT, near a large Hg mine) in subtropical south China for a full year from January to December in 2014. The GEM flux measurements over forest canopy in QYZ and HT showed net emission with annual average values of 6.67 and 1.21 ng m−2 h−1 respectively. Daily variations of GEM fluxes showed an increasing emission with the increasing air temperature and solar radiation in the daytime to a peak at 1:00 pm, and decreasing emission thereafter, even as a GEM sink or balance at night. High temperature and low air Hg concentration resulted in the high Hg emission in summer. Low temperature in winter and Hg absorption by plant in spring resulted in low Hg emission, or even adsorption in the two seasons. GEM fluxes were positively correlated with air temperature, soil temperature, wind speed, and solar radiation while negatively correlated with air humidity and atmospheric GEM concentration. The lower emission fluxes of GEM at the contaminated site (HT) when comparing with that in the clean site (QYZ), may result from a much higher adsorption fluxes at night in spite of a similar or higher emission fluxes during daytime. It testified that the higher atmospheric GEM concentration at HT restricted the forest GEM emission. Great attention should be paid on forest as a critical increasing Hg emission source with the decreasing atmospheric GEM concentration in polluted area because of the Hg emission abatement in the future.
Contributions of foreign, domestic and natural emissions to US
ozone estimated using the path-integral method in CAMx nested
within GEOS-Chem
Authors: Dunker Alan M. , Koo Bonyoung , Yarwood Greg
Published: May 2017

Abstract. The Goddard Earth Observing System global chemical transport (GEOS-Chem) model was used at 2° × 2.5° resolution to simulate ozone formation for a base case representing year 2010 and a natural background case without worldwide anthropogenic emissions. These simulations provided boundary concentrations for base and natural background simulations with the Comprehensive Air Quality Model with Extensions (CAMx) on a North American domain at 12 km × 12 km resolution over March–September 2010. The predicted maximum daily average 8-hour (MDA8) background ozone for the US is largest in the mountainous areas of Colorado, New Mexico, Arizona, and California. The background MDA8 ozone in some of these locations exceeds 60 ppb, when averaged over the 10 days with the largest base-case ozone. The ozone difference between the base and background cases represents the increment to ozone from all anthropogenic sources. Using the Path-Integral Method, the anthropogenic ozone increment was allocated to US anthropogenic emissions, Canadian/Mexican anthropogenic emissions, and the anthropogenic components of the lateral and top boundary concentrations (BCs). For the larger MDA8 ozone concentrations in the base case, the relative importance of the sources is generally US emissions > anthropogenic lateral BCs > Canadian/Mexican emissions ≫ anthropogenic top BCs. The contributions of the lateral BCs are largest for the higher elevation US sites in the Intermountain West and sites closest to the boundaries. If the focus instead is on the larger ozone concentrations in the background case, the contribution from US emissions is reduced leading to a reduction in the anthropogenic ozone increment. The contribution of the Canadian/Mexican emissions remains about the same, and the contribution from the lateral BCs increases at lower elevation urban sites. The net effect is that the relative importance of the anthropogenic lateral BCs is significantly increased for the days with the largest background concentrations. In addition to the source apportionment, we also used surface and ozonesonde measurements to evaluate GEOS-Chem and CAMx performance.
The Evolution of Zonally Asymmetric Austral Ozone in a Chemistry
Climate Model
Authors: Dennison Fraser , McDonald Adrian , Morgenstern Olaf
Published: May 2017

Abstract. Asymmetry in the Southern Hemisphere stratospheric ozone hole is important due to both direct radiative heating and its effect on dynamics. It is also a strong indicator of the underlying quality of the stratospheric dynamics of a climate model. We investigate the simulation of the zonal asymmetry in ozone in the NIWA-UKCA atmosphere–ocean–chemistry climate model using elliptical diagnostics, a methodology used for the first time in this subject area. During spring, the region most depleted in ozone is displaced from the pole toward South America based on ERA-Interim and the model output. The model correctly simulates the direction of this displacement but significantly underestimates its magnitude. The model shows that as ozone becomes increasingly depleted over the late 20th century this asymmetry in the ozone distribution moves west, before moving east as polar ozone recovers over the course of the 21st century. Comparison with model runs in which ozone depleting substances are held fixed at pre-ozone hole levels shows this shift is primarily a function of the magnitude of ozone depletion, although increases in greenhouse gases also have some effect.
Ammonia emissions from a grazed field estimated by miniDOAS measurements and inverse dispersion modelling
Authors: Bell Michael , Flechard Chris , Fauvel Yannick , Häni Christoph , Sintermann Jörg , Jocher Markus , Menzi Harald , Hensen Arjan , Neftel Albrecht
Published: May 2017

Abstract. Ammonia (NH3) fluxes were estimated from a field being grazed by dairy cattle during spring by applying a backward Lagrangian stochastic model (bLS) model combined with horizontal concentration gradients measured across the field. Continuous concentration measurements at field boundaries were made by open-path miniDOAS (differential optical absorption spectroscopy) instruments while the cattle were present and for 6 subsequent days. The deposition of emitted NH3 to clean patches on the field was also simulated, allowing both net and gross emission estimates, where the dry deposition velocity (vd) was predicted by a canopy resistance (Rc) model developed from local NH3 flux and meteorological measurements. Estimated emissions peaked during grazing and decreased after the cattle had left the field, while control on emissions was observed from covariance with temperature, wind speed and humidity and wetness measurements made on the field, revealing a diurnal emission profile. Large concentration differences were observed between downwind receptors, due to spatially heterogeneous emission patterns. This was likely caused by uneven cattle distribution and a low grazing density, where hotspots of emissions would arise as the cattle grouped in certain areas, such as around the water trough. The spatial complexity was accounted for by separating the model source area into sub-sections and optimising individual source area coefficients to measured concentrations. The background concentration was the greatest source of uncertainty, and based on a sensitivity/uncertainty analysis the overall uncertainty associated with derived emission factors from this study is at least 30–40 %.Emission factors can be expressed as 6 ± 2 g NH3 cow−1 day−1, or 9 ± 3 % of excreted urine-N emitted as NH3, when deposition is not simulated and 7 ± 2 g NH3 cow−1 day−1, or 10 ± 3 % of excreted urine-N emitted as NH3, when deposition is included in the gross emission model. The results suggest that around 14 ± 4 % of emitted NH3 was deposited to patches within the field that were not affected by urine or dung.
Development, characterization and first deployment of an improved online
reactive oxygen species analyzer
Authors: Zhou Jun , Bruns Emily A. , Zotter Peter , Stefenelli Giulia , Prévôt André S. H. , Baltensperger Urs , EI-Haddad Imad , Dommen Josef
Published: May 2017

Abstract. Inhalation of atmospheric particles is linked to human diseases. Reactive oxygen species (ROS) present in these atmospheric aerosols may play an important role. However, the ROS content in aerosols and their formation pathways are still largely unknown. Here, we have developed an online and offline ROS analyzer using a 2’,7’-dichlorofluorescin (DCFH) based assay. The sensitivity of the ROS analyzer was characterized using a suite of model organic compounds. The instrument detection limit determined as three times the noise is 1.3 nmol L−1 for offline analysis and 2 nmol m−3 of sampled air when the instrument is operated online at a fluorescence response time of approximately 8 min, while the offline method detection limit is 9 nmol L−1 to 13 nmol L−1. Potential interferences from gas phase O3 and NOx, matrix effects of particulate SO42− and NO3− were tested, but not observed. Fe3+ had no influence on the ROS signal while soluble Fe2+ reduced it if present at high concentrations in the extracts. Both online and offline methods were applied to identify the ROS content of different aerosol types, i.e., ambient aerosols as well as fresh and aged aerosols from wood combustion emissions. The stability of the ROS was assessed by comparing the ROS concentration measured by the same instrumentation online in-situ with offline measurements. We also analyzed the evolution of ROS in specific samples by conducting the analysis after storage times of up to four months. The ROS were observed to decay with increasing storage duration. From their decay behavior, ROS in secondary organic aerosol (SOA) can be separated into short- and long-lived fractions, with an average half-life of ~ 1.7 h and ~ 432 d, respectively. All these measurements showed consistently that, on average 60 ± 20 % of the ROS were very reactive and disappeared during the filter storage time. This demonstrates the importance of a fast online measurement of ROS.
Weather dependent estimation of continent-wide wind power generation based on spatio-temporal clustering
Authors: Schyska Bruno U. , Couto António , von Bremen Lueder , Estanqueiro Ana , Heinemann Detlev
Published: May 2017

Abstract. Europe is facing the challenge of increasing shares of energy from variable renewable sources. Furthermore, it is heading towards a fully integrated electricity market, i.e. a Europe-wide electricity system. The stable operation of this large-scale renewable power system requires detailed information on the amount of electricity being transmitted now and in the future. To estimate the actual amount of electricity, upscaling algorithms are applied. Those algorithms – until now – however, only exist for smaller regions (e.g. transmission zones and single wind farms). The aim of this study is to introduce a new approach to estimate Europe-wide wind power generation based on spatio-temporal clustering. We furthermore show that training the upscaling model for different prevailing weather situations allows to further reduce the number of reference sites without losing accuracy.
Assisting the Evolution of the Observing System for the Carbon Cycle through Quantitative Network Design
Authors: Kaminski Thomas , Rayner Peter Julian
Published: May 2017

Abstract. Various observational data streams have been shown to provide valuable constraints on the state and evolution of the global carbon cycle. It is, however, difficult to decide which variables to sample how, where and when in order to achieve an optimal use of the observational capabilities. Quantitative Network Design (QND) assesses the impact of a given set of existing or hypothetical observations in a modelling framework. QND has been used to optimise in situ networks and assess the benefit from planned space missions. This paper describes recent progress and points at aspects that are not yet sufficiently addressed. It demonstrates the advantage of an integrated QND system that can simultaneously evaluate a multitude of observational data streams and assess their complementarity and redundancy.
The effects of carbon turnover time on terrestrial ecosystem carbon storage
Authors: Yan Yaner , Zhou Xuhui , Jiang Lifeng , Luo Yiqi
Published: May 2017

Abstract. Carbon (C) turnover time is a key factor in determining C storage capacity in various plant and soil pools and the magnitude of terrestrial C sink in a changing climate. However, the effects of C turnover time on C storage have not been well quantified for previous researches. Here, we first analyzed the difference among different definition of mean turnover time (MTT) including ecosystem MTT(MTTEC) and soil MTT (MTTsoil) and its variability in MTT to climate changes, and then evaluated the changes of ecosystem C storage driven by MTT changes. Our results showed that total GPP-based ecosystem MTT (MTTEC_GPP : 25.0 ± 2.7 years) was shorter than soil MTT (35.5 ± 1.2 years) and NPP-based ecosystem MTT (MTTEC_NPP:50.8 ± 3 years) MTTEC_GPP = Cpool/GPP & MTTsoil = Csoil/NPP & MTTEC_NPP = Cpool/NPP, Cpool and Csoil referring as the ecosystem or soil carbon storage, respectively). At the biome scale, temperature is still the predictor for MTTEC (R2 = 0.77, p