bluuebunny/crossref_metadata_2025 huggingface dataset:
Asthmatic symptoms and air pollution: a panel study on children living in the Italian Po Valley
Authors: Ranzi Andrea , Freni Sterrantino Anna , Forastiere Francesco , Sartini Claudio , Casale Giovanna , Cavallini Rino , De Togni Aldo , Gallo Lorenza , Lauriola Paolo
Published: November 2015

The Po Valley (Northern Italy) has elevated levels of air-pollution due to various sources of pollution and adverse weather conditions. This study evaluates the short-term effects of exposure to particulate matter with a diameter of 10 microns or less (PM10) on asthma symptoms in school-aged children. An initial cross-sectional survey was conducted in the area to estimate asthma prevalence in children. Out of a total of 250 asthmatic children identified by the study, 69 agreed to participate in a panel study. The PM10 exposure assessment was based on a combination of geographic and environmental measurements leading to a focus on three different areas, each characterised by its own daily PM10 level. Participants were monitored daily for respiratory symptoms for eight weeks (January-March 2006). We assessed the relationship between daily PM10 exposure and occurrence of asthma symptoms with a generalised linear model based on a total of 3864 person-days of observation. Exposure to PM10 per m3 was found to be particularly associated with cough (OR=1.03, CI 95% 0.99; 1.08) and phlegm (OR=1.05, CI 95% 1.00; 1.10). In the most polluted area, exposure to PM10 was also associated with wheezing (OR=1.18, CI 95% 1.02; 1.37).
Pleural Mesothelioma in a young male patient
Authors: Voulgaridis A. , Apollonatou V. , Lykouras D. , Giannopoulos A. , Iliopoulou M. , Karkoulias K. , Kraniotis P. , Prokakis C. , Gkermpesi M. , Spiropoulos K.
Published: November 2015

We present the case of a 33-year-old male patient suffering from lymphocytic pleural effusion, as a result of pleural mesothelioma. Mesothelioma is a malignant tumor of the pleura that is mainly caused by chronic exposure to asbestos fibers and more than 40 years of exposure are needed to develop the disease. Early studies on the relationship of asbestos and mesothelioma were issued in the 1960s. Fibers migrate from the parenchyma of the lung to the visceral pleura. It is widely known that asbestos is an oncogenic factor which can cause damage to DNA. A chest x-ray may reveal pleural effusion with or without pleural thickening, whereas a chest CT may also reveal pleural thickening, uniform and/or lobular. Specific tests, such as immunohistochemical staining, are used in order to help differential diagnosis. Extrapleural pneumonectomy is used as a therapeutic option which involves removal of the lung as well as both the visceral and parietal pleura, the affected part of the pericardium and diaphragm. Surgery should be followed up by radiotherapy and chemotherapy. The surgery may lead to a mean survival rate of approximately 9-21 months. The case presented underlines that in the event of pleural effusion with a lymphocyte type physicians should consider the possibility of a pleural mesothelioma during differential diagnosis, even in relatively young patients.
Pulmonary Rehabilitation in lung cancer
Authors: Pasqua F. , Geraneo K. , Nardi I. , Lococo F. , Cesario A.
Published: November 2015

Non-small-cell lung cancer (NSCLC) represents a very severe disease, being its incidence increasingly reported and, nowadays, successfully treatable only when surgery is deemed to be feasible. Furthermore, the disease and the clinical effects related to the complementary therapies (radio and/or chemotherapy) may strongly affect, frequently with dramatic clinical side effects, the patient’s ability to endure physical exercise. In such context, the PR(PR), which has already been proved to be useful and effective in other diseases such as COPD, could play a pivotal role. The aim of this review article is, therefore, to analyze the pertinent data recently reported in English literature in order to highlight the role of rehabilitation as complementary therapy in the management of patients with NSCLC. The evidence currently available suggests that, when surgery is indicated, PR is a safe and feasible option, both during pre-operative and post-operative timing.The safety and feasibility of rehabilitation are proven even in inoperable patients, although to date, little evidence has been reported on its role in the overall management of such complex diseases.
Hyperventilation and seizures in an adolescent female
Authors: Nicosia F. , Giordano L. , Bonini L. , Corda L. , Bolzon M. , Bettinzoli M. , Braghini A. , Accorsi P. , Tantucci C.
Published: November 2015

A 16 year-old girl was admitted after suffering from recurrent episodes of dyspnea and stridor, cyanosis, loss of contact, stiffening of all four limbs, clenching of the jaw and eye retroversion that lasted for a few seconds to a minute, followed by slow recovery of consciousness without any loss of sphincter control. These symptoms began at the age of 11 and worsened over time. Prolonged rate corrected QT intervals was observed with an ECG. Two cardio-respiratory monitorings were performed (one during daytime hours while the patient was awake, and one at night time while the patient slept). Daytime recordings showed 17 central apnoeas and 97 central hypopneas, with an apnea-hypopnea index (AHI) of 13.2 events/hour, that were associated with severe oxyhemoglobin desaturation. In contrast, night time recordings were normal (AHI=1.1 events/hour). The patient underwent diurnal monitoring of transcutaneous pCO2(PtcCO2), transcutaneous O2(PtcO2), SpO2 and end tidal CO2 (PETCO2), with simultaneous monitoring of regional cerebral oxymetry (rSO2) which showed values of PtcCO2 between 8 and 15 mmHg, suggesting several episodes of marked hyperventilation. Twenty-nine episodes of severe arterial desaturation (SpO2<50%) were registered, all after the same number of apnea events, with ascent of PtcO2 up to 28 mmHg at the end of apnea. During the final phase of apnea, the patient showed cyanosis, contact disturbance, grimaces, oral movements of rhyme, and, on three occasions, partial seizures. A mask was packaged and applied daytime to the face of the patient during episodes of hyperventilation to prevent, together with a psychiatric follow up, rapid falls of PaCO2 levels determining central apnoeas.
Primary plasma cell leukaemia in a 22-year-old woman: A case report
Authors: Marshall Robyn , Vaughan Jenifer , David Ria , Schapkaitz Elise , Carmona Sergio , Wiggill Tracey
Published: November 2015

Introduction: Primary plasma cell leukaemia is a rare and highly aggressive disease that is commonly diagnosed a decade earlier than multiple myeloma, at a median age of 55 years. However, it has also been described in younger patients, as documented in this case report. It often presents with hepatosplenomegaly and lymphadenopathy, whilst the presence of bony lesions are less-commonly seen when compared to multiple myeloma.Case presentation: This report describes the case of a young woman who presented with symptoms of anaemia and a history of menorrhagia. On further careful examination, she was found to have additional signs and symptoms and was later diagnosed with primary plasma cell leukaemia.Management and outcome: On admission, the patient received supportive care measures, including blood products. At diagnosis, a specific chemotherapy regimen was commenced; however, this failed to induce remission. The decision to continue with supportive care only was made and the patient died seven months later.Discussion: This case study is presented because of its rarity, the young age of the patient at presentation and the unusual clinical and laboratory findings. Persistent anaemia unresponsive to standard treatment should raise the index of suspicion and further investigations directed to exclude malignancies should be considered. (Full article to follow)
Assessing the use of contraceptives by female undergraduate students in a selected higher educational institution in Gauteng
Authors: Coetzee Maria H. , Ngunyulu Roinah N.
Published: November 2015

Background: Unplanned pregnancies amongst students at higher education institutions are a major concern worldwide, including South Africa. Apart from various social and psychological challenges, unplanned pregnancies affect students’ objectives of achieving academic success. Research undertaken in the United States of America (USA) indicates that around 80% of female students in institutions of higher education between ages 18 and 24 are sexually active.Objectives: To assess and describe the use of contraceptives by undergraduate female students in a selected higher educational institution in Gauteng.Method: A cross-sectional, descriptive, quantitative design was used. A total of 400 female undergraduate students were requested to respond to a self-administered questionnaire. Stratified random sampling was used to select the participants. They were selected systematically from two campuses. Data were entered using an excel sheet at the Department of Statistics, and analysed using the Statistical Analysis Software programme, (SAS version 9.3), of the Department of Statistics’ higher educational institutions.Results: A total of 74%females indicated they were sexually active, 79%of whom reported using contraceptives. The most common used methods were oral contraceptives at 38%, and 25% for male condoms. The most commonly known methods were condoms at 84%, and the oral contraceptive at 68%. The knowledge of condom use to prevent sexually transmitted diseases was high at 91%.Conclusion: Inadequate knowledge and awareness on some contraceptive methods was found. Thus, educational programmes to increase students’ knowledge on the use of all contraceptive methods are urgently needed
Health challenges in South African automotive companies: Wellness in the workplace
Authors: Meyer-Weitz Anna , Baasner-Weihs Friederike , Weihs Martin
Published: November 2015

Orientation: In South Africa, workplace programmes in the automotive industry focus predominantly on occupational health and safety and HIV and AIDS. The implementation of focused workplace interventions might be hampered when companies are not convinced that the condition (i.e. HIV and AIDS) is the main negative health influencing factor responsible for increased production costs.Research purpose: The study investigated the health influencing conditions perceived to negatively impact company production costs and related interventions.Motivation for the study: Apart from HIV and AIDS, little information is available about the health challenges in the South African workplace and focused HIV and AIDS programmes might only partly respond to the key health challenges of workplaces. The inter-relatedness of various risky lifestyle factors linked to health conditions necessitates a comprehensive health promotion approach.Research approach, design and method: A cross-sectional survey was conducted amongst 74 companies selected through stratified random sampling. Non-parametric tests were conducted to investigate the health influencing factors perceived to impact production costs, the monitoring thereof, extent of containment and the implementation of interventions in terms of company size and ownership.Main findings: The health factors perceived to have a moderate to large impact were HIV and AIDS, smoking, alcohol use, stress, back and neck ache and tuberculosis, also reported to be better monitored and managed by medium and large organisations. Small organisations reported a smaller impact, fewer efforts and less success. HIV and AIDS programmes were more evident in large companies and those with wellness programmes (52%). Workplace programmes enabled better monitoring and managing of impacting health conditions. Smaller organisations were not convinced of the benefits of interventions in addressing health challenges.Practical/managerial implications: As the impacting health conditions seemed linked, comprehensive and integrated wellness programmes are required to address the health issues and ensure organisations’ competitiveness.Contribution: The results contribute to a better understanding of the perceived salient health influencing factors that impact on production costs. Data support the inter-relationships between the identified health concerns and call for more holistic wellness programmes.
Welcome Message from the Editors-in-Chief
Authors: Alonso-Zarate Jesus , Dohler Mischa
Published: November 2015

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Device-to-Device Communications for 5G Internet of Things
Authors: Militano L. , Araniti G. , Condoluci M. , Farris I. , Iera A.
Published: November 2015

The proliferation of heterogeneous devices connected through large-scale networks is a clear sign that the vision of the Internet of Things (IoT) is getting closer to becoming a reality. Many researchers and experts in the field share the opinion that the next-to-come fifth generation (5G) cellular systems will be a strong boost for the IoT deployment. Device-to- Device (D2D) appears as a key communication paradigm to support heterogeneous objects interconnection and to guarantee important benefits. In this paper, we thoroughly discuss the added-value features introduced by cellular/noncellular D2D communications and its potential in efficiently fulfilling IoT requirements in 5G networks. State-of-the-art solutions, enabling radio technologies, and current standardization activities for D2D communications are surveyed and their pros and cons with reference to manifold IoT use cases pointed out. Future research directions are then presented towards a fully converged 5G IoT ecosystem.
Crowdsensing Solutions in Smart Cities towards a Networked Society
Authors: Petkovics Á. , Simon V. , Gódor I. , Böröcz B.
Published: November 2015

The goal of the paper is to give an overview of the most relevant aspects of mobile crowdsensing that are already utilized by the society. The paper focuses on best practices applied in smart cities today, how these applications can be motivated (incentives), and how they rely on technology enablers of today’s vertical silos and future’s horizontal approaches. We introduce a path for transforming the vertical silos of today containing separated solutions in various domains into a horizontal, unified ecosystem, giving a way to novel technology and business opportunities.
IoT Community Technologies: Leaving Users to Their Own Devices or Orchestration of Engagement?
Authors: Balestrini M. , Diez T. , Marshall P. , Gluhak A. , Rogers Y.
Published: November 2015

Citizens are increasingly crowdfunding IoT based participatory sensing technologies that allow them to collect and share data about the environment. These initiatives are usually referred to as grassroots and are driven by a vision of widening access to tools for political action. In this paper we compare patterns of participation and user experience over 15 months in two distinct communities using ‘Smart Citizen’, a crowdfunded IoT participatory sensing tool. Our studies reveal that technology issues and a lack of reliability of the sensed data hindered user participation. However, in one of the communities, many of these challenges were overcome through orchestrated actions led by community champions. We discuss how crowdfunding doesn’t necessarily translate into active participation and provide guidelines on how to achieve sustained engagement in crowdfunded IoT community sensing projects: enable distributed orchestration provided by local champions, encourage social interactions that embed skills and learning, and facilitate meaningful participation and reward mechanisms among community members.
Quantity-of-money fluctuations and economic instability: empirical evidence for the USA (1958–2006)*
Authors: Michaelides Panayotis G. , Milios John G. , Konstantakis Konstantinos N. , Tarnaras Panayiotis
Published: November 2015

This paper examines the relation between the fluctuations in the quantity of money and the fluctuations in economic activity; that is, the cyclical components of each variable. The principal question posed is: how do the fluctuations in the quantity of money affect or get affected by the fluctuations of output and profitability in the US economy (1958–2006)? Our investigation stops in 2006 as the dynamics of the traditional economic structures changed dramatically in the US and globally after 2006. The empirical results indicate strong cyclical behaviour of most variables. Furthermore, the cyclical components of output/profitability and the quantity of money move in the same direction and there is also a significant relationship between them. A very interesting result is that fluctuations in output/profitability do cause fluctuations in the quantity of money, but fluctuations in the quantity of money do not cause fluctuations in output/profitability, giving priority to a ‘macroeconomic’ point of view, where overall economic activity, expressed through profitability and output, shapes (but is not shaped by) the quantity of money. Our empirical findings, thus, imply a revision of the usual reading which favours causality running from the quantity of money.
Africa's food security in a broken global food system: what role for plant breeders’ rights?
Authors: Oguamanam Chidi
Published: November 2015

The food security discourse has moved from the historic emphasis on increased food production and the eradication of hunger to a holistic and multidisciplinary outlook under the food system model. However, the importance of the legal dimensions of the food system discourse has yet to be fully felt or demonstrated within the diverse disciplinary and policy spaces for understanding the food security and food system interface. This article focuses on contemporary developments in Africa on plant breeders’ rights (PBRs) – an important aspect of law and policy on innovation over plant genetic resources for food and agriculture. It observes that the focus of recent legal developments on PBRs in Africa diverges from the centrality of smallholder farmers as the principal food and agricultural producers on the continent. Critically focusing on Africa's emergent policy reversal in favour of PBRs, the article underscores how legal developments are integral to fully understanding the dynamics of food security within a fractured global food system, especially as they relate to the African continent.
Enforcing the WTO rulings on trade marks and trade names in Havana Club
Authors: Kennedy Matthew
Published: November 2015

The WTO decided in 2002 that a provision of US law blocking enforcement of rights to the Havana Club rum trade mark and trade name was inconsistent with the TRIPS Agreement. Even though the WTO's rulings remain unimplemented today, the European Union has never requested a remedy to enforce them. The difficulties in enforcing the rulings cannot simply be explained by the US embargo on trade with Cuba. Rather, the rulings were based on hypothetical scenarios and a category of intellectual property right (trade name protection) that is not covered by the WTO rules on retaliation. In these circumstances, the WTO dispute settlement rules are not designed to provide an effective inducement to compliance. The problematic rulings were all introduced on appeal and expose operational problems in the Dispute Settlement Understanding (DSU) procedures as applied to TRIPS.
Gene-related inventions in Europe: purpose- vs function-bound protection
Authors: Lai Jessica C
Published: November 2015

Biotech inventions have proved to be severely challenging for patent law systems around the world. European states have attempted to meet these challenges, resulting in law that directly deals with biotechnology at the national and European level. However, whether different states have dealt with biotechnology in a logical and clear manner is another question. This article discusses law that has been created through the European Union and European Patent Office, before addressing and comparing the manner in which Germany and Switzerland have implemented this law into their national statutes. It concludes that neither state has technologically sound law, creating distinctions that are not practically logical. The final part of this article discusses a term that was introduced into European patent law through the ‘Biotech Directive’, through the requirement that applicants disclose an industrial application or ‘function’ for a sequence or partial sequence of a gene. The term ‘function’ has been taken up by both Germany and Switzerland, but its potential – particularly in contrast to the term ‘industrial application’ – has yet to be realized. Though one often speaks of purpose-bound claims, this article explores the possibility of function-bound claims.
Expanding the reach of India's ‘Bolar’ exemption
Authors: Kolawole Oke Emmanuel
Published: November 2015

In November 2014, the scope of the regulatory review exemption contained in section 107A(a) of the Indian Patents Act was considered by the Delhi High Court in the case of Bayer Corporation v Union of India. In this case, which is a sequel to the compulsory licence that was earlier granted to Natco in respect of Bayer's patented drug in 2012, Natco sought to export 1 kilogramme of the patented active pharmaceutical ingredient to a company in China. Bayer contended that this was in breach of the terms of the compulsory licence and equally outside the scope of section 107A(a). Natco however argued for a broader interpretation of section 107A(a) in a manner that will permit the exportation of patented active pharmaceutical ingredients to producers of generic drugs solely for the purposes of generating information required for obtaining regulatory approval. In accepting Natco's broader interpretation of section 107A(a), the Delhi High Court incorporated a model of human rights into its decision by being mindful of the implications that a restrictive interpretation of section 107A(a) could have on the production of cheaper generic drugs and access to medicines. This decision reinforces India's crucial position as the ‘pharmacy of the developing world’.
Introduction: The Pan-Eurasian Experiment (PEEX) – multidisciplinary, multiscale and multicomponent research and capacity-building initiative
Authors: Kulmala M. , Lappalainen H. K. , Petäjä T. , Kurten T. , Kerminen V.-M. , Viisanen Y. , Hari P. , Sorvari S. , Bäck J. , Bondur V. , Kasimov N. , Kotlyakov V. , Matvienko G. , Baklanov A. , Guo H. D. , Ding A. , Hansson H.-C. , Zilitinkevich S.
Published: November 2015

Abstract. The Pan-Eurasian Experiment (PEEX) is a multidisciplinary, multiscale and multicomponent research, research infrastructure and capacity-building program. PEEX has originated from a bottom-up approach by the science communities and is aiming at resolving the major uncertainties in Earth system science and global sustainability issues concerning the Arctic and boreal pan-Eurasian regions, as well as China. The vision of PEEX is to solve interlinked, global grand challenges influencing human well-being and societies in northern Eurasia and China. Such challenges include climate change; air quality; biodiversity loss; urbanization; chemicalization; food and freshwater availability; energy production; and use of natural resources by mining, industry, energy production and transport sectors. Our approach is integrative and supra-disciplinary, recognizing the important role of the Arctic and boreal ecosystems in the Earth system. The PEEX vision includes establishing and maintaining long-term, coherent and coordinated research activities as well as continuous, comprehensive research and educational infrastructure and related capacity-building across the PEEX domain. In this paper we present the PEEX structure and summarize its motivation, objectives and future outlook.
Enhanced internal gravity wave activity and breaking over the northeastern Pacific–eastern Asian region
Authors: Šácha P. , Kuchař A. , Jacobi C. , Pišoft P.
Published: November 2015

Abstract. We have found a stratospheric area of anomalously low annual cycle amplitude and specific dynamics in the stratosphere over the northeastern Pacific–eastern Asia coastal region. Using GPS radio occultation density profiles from the Formosat Satellite Mission 3/Constellation Observing System for Meteorology, Ionosphere, and Climate (FORMOSAT-3/COSMIC), we have discovered an internal gravity wave (IGW) activity and breaking hotspot in this region. Conditions supporting orographic wave sourcing and propagation were found. Other possible sources of wave activity in this region are listed. The reasons why this particular IGW activity hotspot was not discovered before as well as why the specific dynamics of this region have not been pointed out are discussed together with the weaknesses of using the mean potential energy as a wave activity proxy. Possible consequences of the specific dynamics in this region on the middle atmospheric dynamics and transport are outlined.
The regime of aerosol asymmetry parameter over Europe, the Mediterranean and the Middle East based on MODIS satellite data: evaluation against surface AERONET measurements
Authors: Korras-Carraca M. B. , Hatzianastassiou N. , Matsoukas C. , Gkikas A. , Papadimas C. D.
Published: November 2015

Abstract. Atmospheric particulates are a significant forcing agent for the radiative energy budget of the Earth–atmosphere system. The particulates' interaction with radiation, which defines their climate effect, is strongly dependent on their optical properties. In the present work, we study one of the most important optical properties of aerosols, the asymmetry parameter (gaer), over sea surfaces of the region comprising North Africa, the Arabian Peninsula, Europe, and the Mediterranean Basin. These areas are of great interest, because of the variety of aerosol types they host, both anthropogenic and natural. Using satellite data from the collection 051 of MODIS (Moderate Resolution Imaging Spectroradiometer, Terra and Aqua), we investigate the spatiotemporal characteristics of the asymmetry parameter. We generally find significant spatial variability, with larger values over regions dominated by larger size particles, e.g., outside the Atlantic coasts of northwestern Africa, where desert-dust outflow takes place. The gaer values tend to decrease with increasing wavelength, especially over areas dominated by small particulates. The intra-annual variability is found to be small in desert-dust areas, with maximum values during summer, while in all other areas larger values are reported during the cold season and smaller during the warm. Significant intra-annual and inter-annual variability is observed around the Black Sea. However, the inter-annual trends of gaer are found to be generally small. Although satellite data have the advantage of broad geographical coverage, they have to be validated against reliable surface measurements. Therefore, we compare satellite-measured values with gaer values measured at 69 stations of the global surface AERONET (Aerosol Robotic Network), located within our region of interest. This way, we provide some insight on the quality and reliability of MODIS data. We report generally better agreement at the wavelength of 860 nm (correlation coefficient R up to 0.47), while at all wavelengths the results of the comparison were better for spring and summer.
Vertical and horizontal variability of PM10 source contributions in Barcelona during SAPUSS
Authors: Brines M. , Dall'Osto M. , Amato F. , Minguillón M. C. , Karanasiou A. , Alastuey A. , Querol X.
Published: November 2015

Abstract. During the SAPUSS campaign (Solving Aerosol Problems by Using Synergistic Strategies) PM10 samples at twelve hours resolution were simultaneously collected at four monitoring sites located in the urban agglomerate of Barcelona (Spain). A total of 221 samples were collected from 20 September to 20 October 2010. The Road Site (RS) site and the Urban Background (UB) site were located at street level, whereas the Torre Mapfre (TM) and the Torre Collserola (TC) sites were located at 150 m a.s.l. by the sea side within the urban area and at 415 m a.s.l. 8 km inland, respectively. For the first time, we are able to report simultaneous PM10 aerosol measurements allowing us to study aerosol gradients at both horizontal and vertical levels. The complete chemical composition of PM10 was determined on the 221 samples, and factor analysis (Positive Matrix Factorisation, PMF) was applied. This resulted in eight factors which were attributed to eight main aerosol sources affecting PM10 concentrations in the studied urban environment: (1) vehicle exhaust and wear (2–9 μg m−3, 10–27 % of PM10 mass on average), (2) road dust (2–4 μg m−3, 8–12 %), (3) mineral dust (5 μg m−3, 13–26 %), (4) aged marine (3–5 μg m−3, 13–20 %), (5) heavy oil (0.4–0.6 μg m−3, 2 %), (6) industrial (1 μg m−3, 3–5 %), (7) sulphate (3–4 μg m−3, 11–17 %) and (8) nitrate (4–6 μg m−3, 17–21 %). Three aerosol sources were found enhanced at the ground levels (confined within the urban ground levels of the city) relative to the upper levels: (1) vehicle exhaust and wear (2.8 higher), (2) road dust (1.8 higher) and (3) local urban industries/crafts workshops (1.6 higher). Surprisingly, the other aerosol sources were relatively homogeneous at both horizontal and vertical levels. However, air mass origin and meteorological parameters also played a key role in influencing the variability of the factors concentrations. The mineral dust and aged marine factors were found to be a mixture of natural and anthropogenic components and were thus further investigated. Overall, three types of dust were identified to affect the urban study area: road dust (35 % of the mineral dust load, 2–4 μg m−3 on average), Saharan dust (28 %, 2.1 μg m−3) and background mineral dust (37 %, 2.8 μg m−3). Our results evidence that although the city of Barcelona broadly shows a homogeneous distribution of PM10 pollution sources, non-exhaust traffic, exhaust traffic and local urban industrial activities are major coarse PM10 aerosol sources.
Observations and implications of liquid–liquid phase separation at high relative humidities in secondary organic material produced by α-pinene ozonolysis without inorganic salts
Authors: Renbaum-Wolff L. , Song M. , Marcolli C. , Zhang Y. , Liu P. F. , Grayson J. W. , Geiger F. M. , Martin S. T. , Bertram A. K.
Published: November 2015

Abstract. Particles consisting of secondary organic material (SOM) are abundant in the atmosphere. To predict the role of these particles in climate, visibility, and atmospheric chemistry, information on particle phase state (i.e. single liquid, two liquids, solid and so forth) is needed. This paper focuses on the phase state of SOM particles free of inorganic salts produced by the ozonolysis of α-pinene. Phase transitions were investigated both in the laboratory and with a thermodynamic model over the range of < 0.5 % to 100 % relative humidity (RH) at 290 K. In the laboratory studies, a single phase was observed from 0 to 95 % RH while two liquid phases were observed above 95 % RH. For increasing RH, the mechanism of liquid–liquid phase separation (LLPS) was spinodal decomposition. The RH range at which two liquid phases were observed did not depend on the direction of RH change. In the modelling studies at low RH values, the SOM took up hardly any water and was a single organic-rich phase. At high RH values, the SOM underwent LLPS to form an organic-rich phase and an aqueous phase, consistent with the laboratory studies. The presence of LLPS at high RH-values has consequences for the cloud condensation nuclei (CCN) activity of SOM particles. In the simulated Köhler curves for SOM particles, two local maxima are observed. Depending on the composition of the SOM, the first or second maximum can determine the critical supersaturation for activation. The presence of LLPS at high RH-values can explain inconsistencies between measured CCN properties of SOM particles and hygroscopic growth measured below water saturation.
Comprehensive tool for calculation of radiative fluxes: illustration of shortwave aerosol radiative effect sensitivities to the details in aerosol and underlying surface characteristics
Authors: Derimian Y. , Dubovik O. , Huang X. , Lapyonok T. , Litvinov P. , Kostinski A. , Dubuisson P. , Ducos F.
Published: November 2015

Abstract. The evaluation of aerosol radiative effect on broadband hemispherical solar flux is often performed using simplified spectral and directional scattering characteristics of atmospheric aerosol and underlying surface reflectance. In this study we present a rigorous yet fast computational tool that accurately accounts for detailed variability of both spectral and angular scattering properties of aerosol and surface reflectance in calculation of direct aerosol radiative effect. The tool is developed as part of the GRASP (Generalized Retrieval of Aerosol and Surface Properties) project. We use the tool to evaluate instantaneous and daily average radiative efficiencies of several key atmospheric aerosol models over different surface types. We then examine the differences due to neglect of surface reflectance anisotropy, non-sphericity of aerosol particle shape and accounting only for aerosol angular scattering asymmetry instead of using full phase function. For example, it is shown that neglecting aerosol particle nonsphericity causes mainly overestimation of the aerosol cooling effect and that magnitude of this overestimate changes significantly as a function of solar zenith angle (SZA) if only asymmetry parameter is used instead of detailed phase function. It was also found that the nonspherical–spherical differences in the calculated aerosol radiative effect are not modified significantly if detailed BRDF (Bidirectional Reflectance Distribution Function) is used instead of Lambertian approximation of surface reflectance. Additionally, calculations show that usage of only angular scattering asymmetry, even for case of spherical aerosols, modifies dependence of instantaneous aerosol radiative effect on SZA. This effect can be canceled for daily average values, but only if sun reaches the zenith, otherwise a systematic bias remains. Since the daily average radiative effect is obtained by integration over a range of SZAs, the errors vary with latitude and season. In summary, the present analysis showed that use of simplified assumptions causes systematic biases, rather than random uncertainties, in calculation of both instantaneous and daily average aerosol radiative effect. Finally, we illustrate application of the rigorous aerosol radiative effect calculations performed as part of GRASP aerosol retrieval from real POLDER/PARASOL satellite observations.
Predicting ambient aerosol thermal-optical reflectance (TOR) measurements from infrared spectra: extending the predictions to different years and different sites
Authors: Reggente M. , Dillner A. M. , Takahama S.
Published: November 2015

Abstract. Organic carbon (OC) and elemental carbon (EC) are major components of atmospheric particulate matter (PM), which has been associated with increased morbidity and mortality, climate change and reduced visibility. Typically OC and EC concentrations are measured using thermal optical methods such as thermal optical reflectance (TOR) from samples collected on quartz filters. In this work, we estimate TOR OC and EC using Fourier transform infrared (FT-IR) absorbance spectra from polytetrafluoroethylene (PTFE or Teflon) filters using partial least square regression (PLSR) calibrated to TOR OC and EC measurements for a wide range of samples. The proposed method can be integrated with analysis of routinely collected PTFE filter samples that, in addition to OC and EC concentrations, can concurrently provide information regarding the composition of the organic aerosol. We have used the FT-IR absorbance spectra and TOR OC and EC concentrations collected in the Interagency Monitoring of PROtected Visual Environment (IMPROVE) network (USA). We used 526 samples collected in 2011 at seven sites to calibrate the models, and more than 2000 samples collected in 2013 at 17 sites to test the models. Samples from six sites are present both in the calibration and test sets. The calibrations produce accurate predictions both for samples collected at the same six sites present in the calibration set (R2=0.97 and R2=0.95 for OC and EC respectively), and for samples from nine of the 11 sites not included in the calibration set (R2=0.96 and R2=0.91 for OC and EC respectively). Samples collected at the other two sites require a different calibration model to achieve accurate predictions. We also propose a method to anticipate the prediction error: we calculate the squared Mahalanobis distance in the feature space (scores determined by PLSR) between new spectra and spectra in the calibration set. The squared Mahalanobis distance provides a crude method for assessing the magnitude of mean error when applying a calibration model to a new set of samples.
Technical note: Time lag correction of aquatic eddy covariance data measured in the presence of waves
Authors: Berg P. , Reimers C. E. , Rosman J. H. , Huettel M. , Delgard M. L. , Reidenbach M. A. , Özkan-Haller H. T.
Published: November 2015

Abstract. Extracting benthic oxygen fluxes from eddy covariance time series measured in the presence of surface gravity waves requires careful consideration of the temporal alignment of the vertical velocity and the oxygen concentration. Using a model based on linear wave theory and measured eddy covariance data, we show that a substantial error in flux can arise if these two variables are not aligned correctly in time. We refer to this error in flux as the time lag bias. In one example, produced with the wave model, we found that an offset of 0.25 s between the oxygen and the velocity data produced a 2-fold overestimation of the flux. In another example, relying on nighttime data measured over a seagrass meadow, a similar offset reversed the flux from an uptake of −50 mmol m−2 d−1 to a release of 40 mmol m−2 d−1. The bias is most acute for data measured at shallow-water sites with short-period waves and low current velocities. At moderate or higher current velocities (> 5–10 cm s−1), the bias is usually insignificant. The widely used traditional time shift correction for data measured in unidirectional flows, where the maximum numerical flux is sought, should not be applied in the presence of waves because it tends to maximize the time lag bias or give unrealistic flux estimates. Based on wave model predictions and measured data, we propose a new time lag correction that minimizes the time lag bias. The correction requires that the time series of both vertical velocity and oxygen concentration contain a clear periodic wave signal. Because wave motions are often evident in eddy covariance data measured at shallow-water sites, we encourage more work on identifying new time lag corrections.
Chlorophyll a-specific Δ14C, δ13C and δ15N values in stream periphyton: implications for aquatic food web studies
Authors: Ishikawa N. F. , Yamane M. , Suga H. , Ogawa N. O. , Yokoyama Y. , Ohkouchi N.
Published: November 2015

Abstract. Periphytic algae attached to a streambed substrate (periphyton) are an important primary producer in stream ecosystems. We determined the isotopic composition of chlorophyll a in periphyton collected from a stream flowing on limestone bedrock in the Seri River, central Japan. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) and natural radiocarbon abundances (Δ14C) were measured in chlorophyll a (δ13Cchl, δ15Nchl and Δ14Cchl) and bulk (δ13Cbulk, δ15Nbulk and Δ14Cbulk) for periphyton, a pure aquatic primary producer (Cladophora sp.) and a terrestrial primary producer (Quercus glauca). Periphyton δ13Cbulk and δ13Cchl values did not necessarily correspond to δ13Cbulk for an algal-grazing specialist (Epeorus latifolium). Periphyton Δ14Cchl values (−258 ‰ in April and −190 ‰ in October) were slightly lower than Δ14Cbulk values (−228 ‰ in April and −179 ‰ in October) but were close to the Δ14C value for dissolved inorganic carbon (DIC; −217 ± 31 ‰), which is a mixture of weathered carbonates (Δ14C = −1000 ‰), CO2 derived from aquatic and terrestrial organic matters (variable Δ14C) and dissolved atmospheric CO2 (Δ14C approximately +30 ‰ in 2013). Δ14Cchl values were also close to Δ14Cbulk for E. latifolium (−215 ‰ in April and −199 ‰ in October) and Cladophora sp. (−210 ‰), whereas the Δ14Cbulk value for Q. glauca (+27 ‰) was closer to Δ14C for atmospheric CO2. Although the bulk isotopic composition of periphyton is recognised as a surrogate for the photosynthetic algal community, natural periphyton is a mixture of aquatic and terrestrial organic materials. Our results indicate that the bulk periphyton matrix at the study site consists of 89 to 95 % algal carbon (derived from 14C-depleted DIC) and 5 to 11 % terrestrial organic carbon (derived from 14C-enriched atmospheric CO2).
Net global warming potential and greenhouse gas intensity in rice agriculture driven by high yields and nitrogen use efficiency: a 5 year field study
Authors: Zhang X. , Zhou Z. , Liu Y. , Xu X. , Wang J. , Zhang H. , Xiong Z.
Published: November 2015

Abstract. Our understanding of how net global warming potential (NGWP) and greenhouse gas intensity (GHGI) is affected by management practices aimed at food security with respect to rice agriculture remains limited. In the present study, a 5 year field experiment was conducted in China to evaluate the effects of integrated soil-crop system management (ISSM) on NGWP and GHGI after accounting for carbon dioxide (CO2) emissions from all sources (methane, CH4, and nitrous oxide, N2O, emissions, agrochemical inputs, Ei, and farm operations, Eo) and sinks (i.e., soil organic carbon, SOC, sequestration). For the improvement of rice yield and agronomic nitrogen use efficiency (NUE), four ISSM scenarios consisting of different nitrogen (N) fertilization rates relative to the local farmers' practice (FP) rate were carried out, namely, N1 (25 % reduction), N2 (10 % reduction), N3 (FP rate) and N4 (25 % increase). The results showed that compared with the FP, the four ISSM scenarios, i.e., N1, N2, N3 and N4, significantly increased the rice yields by 10, 16, 28 and 41 % and the agronomic NUE by 75, 67, 86 and 82 %, respectively. In addition, compared with the FP, the N1 and N2 scenarios significantly reduced the GHGI by 14 and 18 %, respectively, despite similar NGWPs. The N3 and N4 scenarios remarkably increased the NGWP and GHGI by an average of 67 and 36 %, respectively. In conclusion, the ISSM strategies are promising for both food security and environmental protection, and the ISSM scenario of N2 is the optimal strategy to realize high yields and high NUE together with low environmental impacts for this agricultural rice field.
Was the Little Ice Age more or less El Niño-like than the Mediaeval Climate Anomaly? Evidence from hydrological and temperature proxy data
Authors: Henke L. M. K. , Lambert F. H. , Charman D. J.
Published: November 2015

Abstract. The El Niño-Southern Oscillation (ENSO), an ocean–atmosphere coupled oscillation over the equatorial Pacific, is the most important source of global climate variability on inter-annual time scales. It has substantial environmental and socio-economic consequences such as devastation of South American fish populations and increased forest fires in Indonesia. The instrumental ENSO record is too short for analysing long-term trends and variability, hence proxy data is used to extend the record. However, different proxy sources have produced varying reconstructions of ENSO, with some evidence for a temperature–precipitation divergence in ENSO trends over the past millennium, in particular during the Mediaeval Climate Anomaly (MCA; AD 800–1300) and the Little Ice Age (LIA; AD 1400–1850). This throws into question the stability of the modern ENSO system and its links to the global climate, which has implications for future projections. Here we use a new statistical approach using EOF-based weighting to create two new large-scale ENSO reconstructions derived independently from precipitation proxies and temperature proxies respectively. The method is developed and validated using pseudoproxy experiments that address the effects of proxy dating error, resolution and noise to improve uncertainty estimations. The precipitation ENSO reconstruction displays a significantly more El Niño-like state during the LIA than the MCA, while the temperature reconstruction shows no significant difference. The trends shown in the precipitation ENSO reconstruction are relatively robust to variations in the precipitation EOF pattern. However, the temperature reconstruction suffers significantly from a lack of high-quality, favourably located proxy records, which limits its ability to capture the large-scale ENSO signal. Further expansion of the palaeo-database and improvements to instrumental, satellite and model representations of ENSO are needed to fully resolve the discrepancies found among proxy records.
Reconciling high-altitude precipitation in the upper Indus basin with glacier mass balances and runoff
Authors: Immerzeel W. W. , Wanders N. , Lutz A. F. , Shea J. M. , Bierkens M. F. P.
Published: November 2015

Abstract. Mountain ranges in Asia are important water suppliers, especially if downstream climates are arid, water demands are high and glaciers are abundant. In such basins, the hydrological cycle depends heavily on high-altitude precipitation. Yet direct observations of high-altitude precipitation are lacking and satellite derived products are of insufficient resolution and quality to capture spatial variation and magnitude of mountain precipitation. Here we use glacier mass balances to inversely infer the high-altitude precipitation in the upper Indus basin and show that the amount of precipitation required to sustain the observed mass balances of large glacier systems is far beyond what is observed at valley stations or estimated by gridded precipitation products. An independent validation with observed river flow confirms that the water balance can indeed only be closed when the high-altitude precipitation on average is more than twice as high and in extreme cases up to a factor of 10 higher than previously thought. We conclude that these findings alter the present understanding of high-altitude hydrology and will have an important bearing on climate change impact studies, planning and design of hydropower plants and irrigation reservoirs as well as the regional geopolitical situation in general.
Dissolved oxygen prediction using a possibility-theory based fuzzy neural network
Authors: Khan U. T. , Valeo C.
Published: November 2015

Abstract. A new fuzzy neural network method to predict minimum dissolved oxygen (DO) concentration in a highly urbanised riverine environment (in Calgary, Canada) is proposed. The method uses abiotic (non-living, physical and chemical attributes) as inputs to the model, since the physical mechanisms governing DO in the river are largely unknown. A new two-step method to construct fuzzy numbers using observations is proposed. Then an existing fuzzy neural network is modified to account for fuzzy number inputs and also uses possibility-theory based intervals to train the network. Results demonstrate that the method is particularly well suited to predict low DO events in the Bow River. Model output and a defuzzification technique is used to estimate the risk of low DO so that water resource managers can implement strategies to prevent the occurrence of low DO.