bluuebunny/crossref_metadata_2025 huggingface dataset:
Pneumococcus nasopharyngeal carriage in children attending an academic hospital in Pretoria, South Africa, after the introduction of pneumococcal vaccine
Authors: Newton Charity , Maake Harry , Maluleka Caroline , Mda Siyazi
Published: October 2019

Background: In 2009, pneumococcal conjugate vaccine was introduced in South Africa. However, there are concerns that this could lead to an increase in colonisation of non-vaccine serotypes (serotype replacement).Methods: In a cross-sectional study, 350 children aged 1 month to 14 years were enrolled at Dr George Mukhari Academic Hospital from December 2015 to April 2016. We assessed the prevalence of nasopharyngeal colonisation with pneumococcus and characterised the serotypes found.Results: The median age of the cohort was 33.7 months (interquartile range 16.27–69.5 months), with 20% being 1 year. A total of 21% of the children were diagnosed with pneumococcal-related conditions; among these, pneumonia was the most common condition. Less than half (43%) of the participants were fully immunised. Forty-six (13%) of the children were colonised with pneumococcus. Younger age was significantly associated with pneumococcal colonisation. Among those colonised with pneumococcus, 35% were fully immunised, 30% were partially immunised, 30% had an unknown immunisation status and 4% were unimmunised. Eight (17%) of the children who were colonised with pneumococcus had pneumococcal-related conditions. The commonest serotype identified was 6A/B. Overall, 2% of the cohort were colonised with vaccine-serotype pneumococcus.Conclusion: As a minority of children had evidence of nasopharyngeal colonisation with vaccine-serotype pneumococci, serotype replacement may be emerging in our population.
A community-based cross-sectional study on hypertension screening in Puducherry, India
Authors: Datta Souraja , Sahu Swaroop Kumar , Niranjjan R. , Roy Gautam
Published: October 2019

Background & objectives:

Hypertension is a health problem of global priority. Screening and early diagnosis is important to plan appropriate interventions. The present study objectives were to screen the urban population aged 30 yr and above and diagnose for hypertension and to identify the factors associated with poor screening for hypertension, if any.

Methods:

A community-based descriptive cross-sectional study was conducted in urban field practice area of a tertiary care hospital in Puducherry, India, among individuals aged 30 yr and above. Individuals were asked if they have tested themselves for hypertension in the past two years. Pretested questionnaire was used for data collection. Data collection was done during regular working time of the health centre. All eligible participants from consecutive households were included till the required sample size of 394 was achieved.

Results:

Of the 394 individuals interviewed, 252 (64%) had undergone screening for hypertension. The prevalence of self-reported hypertension among those screened was 26.2 per cent with no significant gender-wise differences. Screening for hypertension was better among females (71.6%) as compared to males (55.2%). Population who were at a higher risk of not getting screened for hypertension were relatively younger (30-44 yr) individuals and males.

Interpretation & conclusions:

The prevalence of self-reported hypertension among those screened was 26.2 per cent [95% confidence interval (21.1-31.9)]. Screening needs to be targeted more towards males and younger population.
Kinetics of viral RNA, immunoglobulin-M & G antibodies in Kyasanur forest disease
Authors: Yadav Pragya D. , Gurav Yogesh K. , Shete Anita M. , Jain Rajlaxmi , Nyayanit Dimpal A. , Pardeshi Prachi G. , Viswanathan Rajlakshmi , Chiplunkar Tushar R. , Awate Pradip , Majumdar Triparna P. , Sahay Rima R. , Mourya Devendra T.
Published: October 2019

Background & objectives:

Kyasanur forest disease (KFD) is an infectious disease discovered in Karnataka State of India in 1957; since then, the State has been known to be enzootic for KFD. In the last few years, its presence was observed in the adjoining five States of the Western Ghats of India. The present study was conducted to understand the kinetics of viral RNA, immunoglobulin M (IgM) and IgG antibody in KFD-infected humans for developing a diagnostic algorithm for KFD.

Methods:

A prospective follow up study was performed among KFD patients in Sindhudurg district of Maharashtra State, India. A total of 1046 suspected patients were tested, and 72 KFD patients were enrolled and followed for 17 months (January 2016 to May 2017). Serum samples of KFD patients were screened for viral RNA, and IgM and IgG antibodies.

Results:

KFD viral positivity was observed from 1st to 18th post-onset day (POD). Positivity of anti-KFD virus (KFDV) IgM antibodies was detected from 4th till 122nd POD and anti-KFDV IgG antibodies detected from 5th till 474th POD. A prediction probability was determined from statistical analysis using the generalized additive model in R-software to support the laboratory findings regarding viral kinetics.

Interpretation & conclusions:

This study demonstrated the presence of KFD viral RNA till 18th POD, IgM antibodies till 122nd POD and IgG till the last sample collected. Based on our study an algorithm was recommended for accurate laboratory diagnosis of KFDV infection. A sample collected between 1 and 3 POD can be tested using KFDV real-time reverse transcriptase polymerase chain reaction (RT-PCR); between 4 and 24 POD, the combination of real-time RT-PCR and anti-KFDV IgM enzyme-linked immunosorbent assay (ELISA) tests can be used; between POD 25 and 132, anti-KFDV IgM and IgG ELISA are recommended.
Wide range of F cell levels in healthy Thai adults
Authors: Tatu Thanusak
Published: October 2019

Background & objectives:

Swiss-type hereditary persistence of foetal haemoglobin (HPFH) has been shown to be responsible for the wide range of F cell levels in healthy Thai adults. However, a survey for F cells in healthy Thai adults has not been performed. This study was conducted to determine the F cell distribution in adult Thai blood donors and to assess the possible involvement of β-thalassaemia and haemoglobin E (HbE) carriers in increased HbF levels.

Methods:

Thai blood donors (n=375, 205 males and 170 females) were included in the study. Blood samples were collected for measuring haemoglobin (Hb) concentration and haematocrit (Hct) and F cell levels. Hb and Hct levels were determined by automated blood counter, while F cells were quantified by flow cytometric analysis of F cells stained by fluorescein isothiocyanate-conjugated anti γ-globin monoclonal antibody. Finally, F cell levels were compared between blood samples having mean corpuscular volume (MCV) <80 fl and ≥80 fl as well as between β-haemoglobinopathies (HbE and β-thalassaemia carriers) and normal adults.

Results:

F cell levels varied markedly spanning 0.80-39.2 per cent with a positively skewed distribution. Thirty two per cent of these individuals had F cell levels more than the 4.5 per cent cut-off point. F cell levels in females were significantly higher than those in males (P<0.05). F cell levels in individuals having MCV <80 fl were significantly higher than those having MCV ≥80 fl (P<0.05). β-haemoglobinopathy (HbE and β-thalassaemia carriers) had significantly higher F cell levels than normal individuals (P<0.05).

Interpretation & conclusions:

The present results showed that besides Swiss-type HPFH, the β-haemoglobinopathy was expected to be involved in increased F cell levels in adult Thais. Thus, influence of β-haemoglobinopathy must be considered in interpreting F cell levels in area endemic of this globin disorder.
Detection of heterogeneous vancomycin-intermediate Staphylococcus aureus
Authors: Amberpet Rajesh , Sistla Sujatha , Sugumar Madhan , Nagasundaram Niveditha , Manoharan Meerabai , Parija Subhash Chandra
Published: October 2019

Background & objectives:

Although there are reports of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) across the globe, there is a lack of reliable data on hVISA in India. The present study was undertaken to determine the rate of hVISA among the methicillin-resistant Staphylococcus aureus (MRSA) isolates, and to compare the brain heart infusion agar with vancomycin 4 μg/ml (BHIV4) method with population analysis profile-area under the curve (PAP-AUC) method for the detection of hVISA and to study the distribution of mobile genetic element that carries methicillin-resistance gene SCCmec (Staphylococcal cassette chromosome mec) types among these isolates.

Methods:

BHIV4 and PAP-AUC methods were employed to detect hVISA among 500 clinical isolates of MRSA. SCCmec typing of these isolates was performed by multiplex polymerase chain reaction. The clinical presentation, treatment with vancomycin and outcome was documented for patients with hVISA.

Results:

The rate of hVISA was 12.4 per cent by PAP-AUC method. Sensitivity, specificity, PPV, NPV and kappa agreement of BHIV4 with PAP-AUC was 58.06, 93.15, 54.55, 94.01 per cent and 0.498, respectively. The isolation of hVISA was significantly (P<0.01) higher in patients admitted to intensive care units and wards than in patients attending the outpatient departments. Only 38 per cent of the patients received vancomycin as therapy. Majority of the hVISA isolates carried SCCmec type V or IV.

Interpretation & conclusions:

The rate of hVISA isolation in our study was 12.4 per cent. The sensitivity of the BHIV4 screening test was low, and was in moderate agreement with PAP-AUC test. SCCmec type V was the predominant type seen in half of the isolates. More studies need to be done in different parts of the country on a large number of isolates to confirm our findings.
High-intensity exercise-induced oxidative stress in sedentary pre-pubertal & post-pubertal boys
Authors: Chaki Biswajit , Pal Sangita , Chattopadhyay Sreya , Bandyopadhyay Amit
Published: October 2019

Background & objectives:

High-intensity exercise results in oxidative stress in adult population. Impact of pubertal attainment on high-intensity exercise-induced oxidative stress in sedentary paediatric population has not been investigated in detail. The present study was conducted to investigate the extent of high-intensity exercise-induced oxidative stress in sedentary pre- and post-pubertal boys through estimation of serum thiobarbituric acid reactive substances (TBARS), total thiol content and activities of superoxide dismutase (SOD) and catalase (CAT).

Methods:

Sixty four sedentary pre-pubertal (n=32, age = 10.21±0.67 yr) and post-pubertal (n=32, age = 15.58±0.47 yr) boys performed incremental treadmill running exercise at 80 per cent of the age predicted maximum heart rate till volitional exhaustion. Blood sample (5 ml) was drawn from each individual before and after the exercise for estimation of oxidative stress markers.

Results:

Pre-exercise SOD activity and total thiol level showed significant positive relationship with age and were significantly higher in post-pubertal boys. Serum TBARS level, SOD and CAT activities increased while total thiol content decreased in both the groups following exercise. Post-exercise percentage change in TBARS, SOD activity and total thiol level was significantly higher in post-pubertal boys, and these variables had significant positive relationship with age. No significant intergroup variations were noted in CAT activity before or after exercise.

Interpretation & conclusions:

Extent of post-exercise oxidative stress increased significantly with attainment of puberty. However, baseline and post-exercise antioxidation status also increased significantly as a function of age with pubertal maturation allowing the post-pubertal boys to counter relatively higher oxidative stress more efficiently than their pre-pubertal counterparts. Post-exercise upregulation in CAT activity might not be influenced by age or pubertal maturation in this age group.
Histotyping of Indian thymomas
Authors: Guleria Prerna , Parshad Rajinder , Malik Prabhat Singh , Ray Ruma , Pandey R.M. , Jain Deepali
Published: October 2019

Background & objectives:

Thymomas are rare, but most common anterior mediastinal lesions. The histomorphologic spectrum of thymic epithelial tumours (TETs) in Indian population has not been explored in depth. This study was aimed to assess the histomorphology of TETs in the Indian patients and correlate clinical parameters with pathological features.

Methods:

It was a retrospective study conducted in a tertiary referral hospital in north India. All morphologically confirmed cases of TETs since 2009 were included. Clinical details and histology slides were reviewed using the Modified Masaoka-Koga staging system and WHO 2015 classification. Clinicopathological correlation and survival analysis were done. A comparative review from other published Indian studies was performed.

Results:

A total of 219 cases of TETs (138 resections and 81 biopsies) were identified. The most common histomorphologic type was B2, and the most frequent stage was I. Types A/AB were common in older age (P<0.01). Clinically, higher stage tumours were found mostly in men (P<0.01), and these were Type B thymomas (P<0.01). Myasthenia gravis was more common in women (P<0.02) and in lower stages (P<0.05). Survival analysis revealed significant association between recurrence and tumour stage. Although thymic carcinoma was diagnosed on biopsy, no resectable case was identified.

Interpretation & conclusions:

Our findings showed that the thymomas in Indian patients were most commonly Stage I tumours of B2 and AB histotypes. Resected thymic carcinomas were conspicuously absent in our study. More studies need to be done to establish the frequency and biology of TETs from India.
Improving survival with tuberculosis & HIV treatment integration
Authors: Naidoo Kogieleum , Rampersad Sanisha , Karim Salim Abdool
Published: October 2019

Tuberculosis (TB) is a leading cause of morbidity and mortality among HIV-infected patients while HIV remains a key risk factor for the development of active TB infection. Treatment integration is a key in reducing mortality in patients with HIV-TB co-infection. However, this opportunity to improve outcomes of both infections is often missed or poorly implemented. Challenges in TB-HIV treatment integration range from complexities involving clinical management of co-infected patients to obstacles in health service-organization and prioritization. This is evident in high prevalence settings such as in sub-Saharan Africa where TB-HIV co-infection rates reach up to 80 per cent. This review discusses published literature on clinical trials and cohort studies of strategies for TB-HIV treatment integration aimed at reducing co-infection mortality. Studies published since 2009, when several treatment guidelines recommended treatment integration, were included. A total of 43 articles were identified, of which a total of 23 observational studies and nine clinical trials were informative on TB-HIV treatment integration. The data show that the survival benefit of AIDS therapy in patients infected with TB can be maximized among patients with advanced immunosuppression by starting antiretroviral therapy (ART) soon after TB treatment initiation, i.e. in patients with CD4+ cell counts <50 cells/μl. However, patients with greater CD4+ cell counts should defer initiation of ART to no less than eight weeks after initiation of TB treatment to reduce the occurrence and extent of immune reconstitution disease and subsequent hospitalization. Addressing operational challenges in integrating TB-HIV care can significantly improve patient outcomes, generate substantial public health impact by decreasing morbidity and death in settings with a high burden of HIV and TB.
Tuberculous meningitis in children
Authors: Daniel Bella Devaleenal , Grace G. Angeline , Natrajan Mohan
Published: October 2019

Although the occurrence of tuberculous meningitis (TBM) in children is relatively rare, but it is associated with higher rates of mortality and severe morbidity. The peak incidence of TBM occurs in younger children who are less than five years of age, and most children present with late-stage disease. Confirmation of diagnosis is often difficult, and other infectious causes such as bacterial, viral and fungal causes must be ruled out. Bacteriological confirmation of diagnosis is ideal but is often difficult because of its paucibacillary nature as well as decreased sensitivity and specificity of diagnostic tests. Early diagnosis and management of the disease, though difficult, is essential to avoid death or neurologic disability. Hence, a high degree of suspicion and a combined battery of tests including clinical, bacteriological and neuroimaging help in diagnosis of TBM. Children diagnosed with TBM should be managed with antituberculosis therapy (ATT) and steroids. There are studies reporting low concentrations of ATT, especially of rifampicin and ethambutol in cerebrospinal fluid (CSF), and very young children are at higher risk of low ATT drug concentrations. Further studies are needed to identify appropriate regimens with adequate dosing of ATT for the management of paediatric TBM to improve treatment outcomes. This review describes the clinical presentation, investigations, management and outcome of TBM in children and also discusses various studies conducted among children with TBM.
Effect of replacing grass hay with maize silage as a basal diet on milk yield and composition of dairy cows
Authors: Kebede Ewonetu , Hundessa Feyisa
Published: October 2019

The objective of this study was to determine effect of replacing grass hay with maize silage on milk production and composition. The study was conducted at Haramaya University dairy research farm -using sixteen crossbred dairy cows (Zebu × Holstein-Friesian) which were assigned to two treatment groups. Each treatment group consisted of eight cows and arranged in a completely randomized experimental design. Cows in both treatment groups were provided similar supplemental concentrate ration formulated from various ingredients but fed on different basal diets which were silage and grass hay. The feeding trial was conducted for a total of 90 days. Milk yield of individual cows were recorded every day and analyzed every two weeks for its chemical composition. Data were analyzed by t-Test for means. The group of cows fed on grass hay relatively produced higher milk yield (17.1) than cows fed on silage (16.1 liters per day). The protein, total solid, solid not fat, and milk urea nitrogen composition were found significantly different between a group of cows fed grass hay and silage. Silage-fed cows gave higher percentage of fat and protein content throughout the experimental period. Milk urea-nitrogen concentration was intensive in cows fed on hay and it was higher than the acceptable range (12 to 18 mg/dl) for the two experimental diets. In conclusion, farmers could use both grass hay and maize silage as substitute to each other in dairy cow diets that could ensure higher quantity and quality milk production.
O papel da corte interamericana de direitos humanos na construção dialogada do ius constitutionale commune na américa latina
Authors: Olsen Ana Carolina Lopes , Kozicki Katya
Published: October 2019

Este artigo tem por objetivo aquilatar o papel da Corte Interamericana de Direitos Humanos na construção do Ius Constitutionale Commune na América Latina, mediante pesquisa bibliográfica doutrinária e jurisprudencial. Para tanto, analisou-se o projeto jurídico de um direito comum formado a partir da interconexão de normas constitucionais e convencionais sobre direitos humanos, a qual fornece uma base jurídica para o constitucionalismo transformador, comprometido em nível nacional e regional com a inclusão social e a realização dos ideais de respeito e promoção da democracia, direitos humanos e Estado de Direito. O desenho institucional que se erige dessa interação tem como pilar diálogos judiciais horizontais e principalmente verticais, em que a Corte Interamericana atua como um vértice canalizador dos sentidos de direitos humanos e impulsionador de sua concretização. Concluiu-se que a Corte, especialmente a partir do diálogo que mantém com cortes nacionais, exerce duas funções primordiais: (i) a harmonização do pluralismo jurídico multinível decorrente da interconexão entre os sistemas constitucionais e o sistema regional, voltada para a construção de standards comuns em direitos humanos; e (ii) o impulsionamento de transformações sociais através de suas sentenças, a fim de tornar efetivos os compromissos constitucionais e convencionais. A partir da compreensão dessas funções, pesquisadores e defensores de direitos humanos têm um campo jurisdicional a explorar a fim de dar continuidade e consistência à realização desses direitos.
¡Qué viva el Estado Plurinacional!: ¿y lo socioambiental?
Authors: Rojas Hernández Anibal Alejandro , Harumi Kanno Paula , Sivini Ferreira Heline , Andrade Précoma Adriele Fernanda
Published: October 2019

El nacimiento de la idea del Estado Plurinacional fue el inicio una transformación en la noción de la estatalidad y el espacio donde se instituyeron países que se re-organizaban desde abajo: con el pueblo y para el pueblo. De aquellos años permanece la nostalgia de sociedades altamente politizadas que vieron en la toma democrática del poder, una opción de reconvertir al Estado en un administrador de sus intereses reales, de sus necesidades insatisfechas. Hoy, paradójicamente, las mayores críticas al Estado Plurinacional emergen de movimientos que exigen la materialización de aquellas promesas del buen vivir. Si bien la inconformidad surge desde una multiplicidad de actores y perspectivas, hay una en particular que ha visto una impugnación generalizada dentro las bases que fundaron y fundamentaron la toma del poder de aquellos gobiernos progresistas: el carácter socioambiental del Estado Plurinacional. ¿Diez años después, el Estado Plurinacional aún mantiene un carácter socioambiental? Para tal fin se examina la noción del buen vivir y el cómo tal categoría hace parte indivisible de la idea Plurinacional del Estado. Inmediatamente se propone un análisis analítico sobre una adaptación del sistema económico a la idea del buen vivir, su relación con lo socioambiental y la incubación de un capitalismo fundamentado en vaciamiento de categorías esenciales para su consolidación. Tales problemáticas son consideradas esenciales tanto para la consolidación pendiente de un modelo de Estado que se ha visto en dificultades y, también, en aprietos a la hora de afianzar aquella relación indivisible que hay entre lo plurinacional y la naturaleza.
O novo constitucionalismo latino-americano: análise marxista da invisibilização da luta de classes nas investigações jurídicas críticas
Authors: Valença Daniel Araújo , Maia Júnior Ronaldo Moreira , Gomes Rayane Cristina de Andrade
Published: October 2019

O presente trabalho tem por objetivo analisar o novo constitucionalismo latino-americano, a partir dos processos de invisibilização da luta de classes nas investigações jurídicas sobre o tema, tendo como lente, o materialismo histórico dialético. Dentre os instrumentos metodológicos, lançaremos mão de revisão bibliográfica, pesquisa documental e entrevistas semiestruturadas. Tendo em vista o método escolhido, a investigação terá como recorte a Bolívia, sua Constituição Política de Estado - CPE e seu Estado Plurinacional, visto que não é possível uma generalização quanto aos países, desconsiderando as particulares formações sociais, estágio específico de desenvolvimento capitalista e de lutas de classes. Pode-se concluir que a originalidade da Constituição Política de 2009 da Bolívia e do Estado Plurinacional reside, para além das disposições quanto à indianização do Estado, no projeto político autônomo das antigas classes subalternas – todavia mediado pela correlação de forças – de transformar o Estado desde uma revolução democrática em seu próprio interior.
Development of a daily PM10 and PM2.5 prediction system using a deep long short-term memory neural network model
Authors: Kim Hyun S. , Park Inyoung , Song Chul H. , Lee Kyunghwa , Yun Jae W. , Kim Hong K. , Jeon Moongu , Lee Jiwon , Han Kyung M.
Published: October 2019

Abstract. A deep recurrent neural network system based on a long
short-term memory (LSTM) model was developed for daily PM10 and
PM2.5 predictions in South Korea. The structural and learnable
parameters of the newly developed system were optimized from iterative model
training. Independent variables were obtained from ground-based
observations over 2.3 years. The performance of the particulate matter (PM)
prediction LSTM was then evaluated by comparisons with ground PM
observations and with the PM concentrations predicted from two sets of 3-D
chemistry-transport model (CTM) simulations (with and without data
assimilation for initial conditions). The comparisons showed, in general,
better performance with the LSTM than with the 3-D CTM simulations. For
example, in terms of IOAs (index of agreements), the PM prediction IOAs were
enhanced from 0.36–0.78 with the 3-D CTM simulations to 0.62–0.79 with the
LSTM-based model. The deep LSTM-based PM prediction system developed at
observation sites is expected to be further integrated with 3-D CTM-based
prediction systems in the future. In addition to this, further possible
applications of the deep LSTM-based system are discussed, together with some
limitations of the current system.
Nepal emission inventory – Part I: Technologies and combustion sources (NEEMI-Tech) for 2001–2016
Authors: Sadavarte Pankaj , Rupakheti Maheswar , Bhave Prakash , Shakya Kiran , Lawrence Mark
Published: October 2019

Abstract. The lack of a comprehensive, up-to-date emission inventory for the
Himalayan region is a major challenge in understanding the extensive
regional air pollution, including its causes, impacts and mitigation
pathways. This study describes a high-resolution (1 km × 1 km)
present-day emission inventory for Nepal, developed with a higher-tier
approach. The complete study is divided into two parts; this paper covers
technologies and combustion sources in residential, industrial, commercial,
agricultural diesel-use and transport sectors as Part I (NEEMI-Tech), while
emissions from the open burning of municipal waste and agricultural residue in
fields and fugitive emissions from waste management, paddy fields, enteric
fermentation and manure management for the period 2001–2016 will be covered
in Part II (NEEMI-Open). The national total energy consumption (except
hydropower, solar and wind energy) estimated in the base year 2011 was 374 PJ, with the residential sector being the largest energy consumer (79 %),
followed by industry (11 %) and the transport sector (7 %). Biomass is
the dominant energy source, contributing to 88 % of the national total
energy consumption, while the rest is from fossil fuel. A total of 8.9 Tg of CO2, 110 Gg of CH4, 2.1 Gg of N2O, 64 Gg of NOx, 1714 Gg of CO, 407 Gg of NMVOCs, 195 Gg of PM2.5, 23 Gg of BC, 83 Gg of OC and 24 Gg of SO2 emissions
were estimated in 2011 from the five energy-use sectors considered in
NEEMI-Tech. The Nepal emission inventory provides, for the first time, temporal trends of fuel and
energy consumption and associated emissions in Nepal for a long period,
2001–2016. The energy consumption showed an increase by a factor of 1.6 in
2016 compared to 2001, while the emissions of various species increased by a
factor of 1.2–2.4. An assessment of the top polluting technologies shows
particularly high emissions from traditional cookstoves and space-heating
practices using biomass. In addition, high emissions were also computed from
fixed-chimney Bull's trench kilns (FCBTKs) in brick production, cement kilns,
two-wheeler gasoline vehicles, heavy-duty diesel freight vehicles and kerosene
lamps. The monthly analysis shows December, January and February as periods
of high PM2.5 emissions from the technology-based sources considered in this
study. Once the full inventory including open burning and fugitive sources
(Part II) is available, a more complete picture of the strength and temporal
variability in the emissions and sources will be possible. Furthermore, the
large spatial variation in the emissions highlights the pockets of growing
urbanization, which emphasize the importance of the detailed knowledge
about the emission sources that this study provides. These emissions will be
of value for further studies, especially air-quality-modeling studies
focused on understanding the likely effectiveness of air pollution
mitigation measures in Nepal.
The Acidity of Atmospheric Particles and Clouds
Authors: Pye Havala O. T. , Nenes Athanasios , Alexander Becky , Ault Andrew P. , Barth Mary C. , Clegg Simon L. , Collett Jr. Jeffrey L. , Fahey Kathleen M. , Hennigan Christopher J. , Herrmann Hartmut , Kanakidou Maria , Kelly James T. , Ku I-Ting , McNeill V. Faye , Riemer Nicole , Schaefer Thomas , Shi Guoliang , Tilgner Andreas , Walker John T. , Wang Tao , Weber Rodney , Xing Jia , Zaveri Rahul A. , Zuend Andreas
Published: October 2019

Abstract. Acidity, defined as pH, is a central component of aqueous chemistry. In the atmosphere, the acidity of condensed phases (aerosol particles, cloud water, and fog droplets) governs the phase partitioning of semi-volatile gases such as HNO3, NH3, and HCl, as well as chemical reaction rates. It has implications for the atmospheric lifetime of pollutants, deposition, and human health. Despite its fundamental role in atmospheric processes, only recently has this field seen a growth in the number of studies on particle acidity. Even with this growth, many fine particle pH estimates must be based on thermodynamic model calculations since no operational techniques exist for direct measurements. Current information indicates acidic fine particles are ubiquitous, but observationally-constrained pH estimates are limited in spatial and temporal coverage. Clouds and fogs are also generally acidic, but to a lesser degree than particles, and have a range of pH that is quite sensitive to anthropogenic emissions of sulfur and nitrogen oxides, as well as ambient ammonia. Historical measurements indicate that cloud and fog droplet pH has changed in recent decades in response to controls on anthropogenic emissions, while the limited trend data for aerosol particles indicates acidity may be relatively constant due to the semi-volatile nature of the key acids and bases and buffering in particles. This paper reviews and synthesizes the current state of knowledge on the acidity of atmospheric condensed phases, specifically particles and cloud droplets. It includes recommendations for estimating acidity and pH, standard nomenclature, a synthesis of current pH estimates based on observations, and new model calculations on the local and global scale.
Sulfur dioxide layer height retrieval from Sentinel-5 Precursor/TROPOMI using FP_ILM
Authors: Hedelt Pascal , Efremenko Dmitry S. , Loyola Diego G. , Spurr Robert , Clarisse Lieven
Published: October 2019

Abstract. The accurate determination of the location, height, and loading of sulfur dioxide (SO2) plumes emitted by volcanic eruptions is essential for aviation safety. The SO2 layer height is also one of the most critical parameters with respect to determining the impact on the climate. Retrievals of SO2 plume height have been carried out using satellite UV backscatter measurements, but, until now, such algorithms are very time-consuming. We have developed an extremely fast yet accurate SO2 layer height retrieval using the Full-Physics Inverse Learning Machine (FP_ILM) algorithm. This is the first time the algorithm has been applied to measurements from the TROPOMI instrument onboard the Sentinel-5 Precursor platform. In this paper, we demonstrate the ability of the FP_ILM algorithm to retrieve SO2 plume layer heights in near-real-time applications with an accuracy of better than 2 km for SO2 total columns larger than 20 DU. We present SO2 layer height results for the volcanic eruptions of Sinabung in February 2018, Sierra Negra in June 2018, and Raikoke in June 2019, observed by TROPOMI.
Comparison of GTO-ECV and Adjusted-MERRA total ozone columns from the last two decades and assessment of interannual variability
Authors: Coldewey-Egbers Melanie , Loyola Diego , Labow Gordon , Frith Stacey
Published: October 2019

Abstract. In this study we compare the satellite-based GOME-type Total Ozone Essential Climate Variable (GTO-ECV) record, generated as part of the European Space Agency's Climate Change Initiative (ESA-CCI) ozone project, with the Adjusted total ozone product from the Modern Era Retrospective Analysis for Research and Applications version 2 (Adjusted-MERRA) reanalysis, produced at the National Aeronautics and Space Administration (NASA) Global Modeling and Assimilation Office (GMAO). Total ozone columns and associated standard deviations show a very good agreement in terms of both spatial and temporal patterns during their 23-year overlap period from July 1995 to December 2018. The mean difference between Adjusted-MERRA and GTO-ECV 5° × 5° monthly mean total ozone columns is −0.9 ± 1.5 %. A small discontinuity in the deviations is detected in October 2004 when data from the Ozone Monitoring Instrument (OMI) was ingested in the GTO-ECV data record. This induces a small overall negative drift in the differences for almost all latitude bands, which, however, does not exceed 1 % decade−1. The mean difference for the period prior to October 2004 is −0.5 ± 1.7 %, whereas the difference is −1.1 ± 1.2 % for the second period. The variability in the differences is considerably reduced in the later period due to significant increase in data coverage and sampling. In the tropical region the differences indicate a slight zonal variability with negative deviations over the Atlantic, Africa, and the Indian Ocean, and positive deviations over the Pacific. Ozone anomalies and the distribution of their statistical moments indicate a very high correlation among both data records as to the temporal and spatial structures. Furthermore, we evaluate the consistency of the datasets by means of an empirical orthogonal function (EOF) analysis. The interannual variability is assessed in the tropics, and both GTO-ECV and Adjusted-MERRA exhibit a remarkable agreement with respect to the derived patterns. The first four EOFs can be attributed to different modes of interannual climate variability, and correlations with the Quasi-Biennial Oscillation (QBO), the El Niño Southern Oscillation (ENSO) signal, and the solar cycle were found.
Spatial distribution of environmental indicators in surface sediments of Lake Bolshoe Toko, Yakutia, Russia
Authors: Biskaborn Boris K. , Nazarova Larisa , Pestryakova Lyudmila A. , Syrykh Liudmila , Funck Kim , Meyer Hanno , Chapligin Bernhard , Vyse Stuart , Gorodnichev Ruslan , Zakharov Evgenii , Wang Rong , Schwamborn Georg , Bailey Hannah L. , Diekmann Bernhard
Published: October 2019

Abstract. Rapidly changing climate in the Northern Hemisphere and associated
socio-economic impacts require reliable understanding of lake systems as
important freshwater resources and sensitive sentinels of environmental
change. To better understand time-series data in lake sediment cores, it is
necessary to gain information on within-lake spatial variabilities of
environmental indicator data. Therefore, we retrieved a set of 38 samples
from the sediment surface along spatial habitat gradients in the boreal,
deep, and yet pristine Lake Bolshoe Toko in southern Yakutia, Russia. Our
methods comprise laboratory analyses of the sediments for multiple proxy
parameters, including diatom and chironomid taxonomy, oxygen isotopes from
diatom silica, grain-size distributions, elemental compositions (XRF),
organic carbon content, and mineralogy (XRD). We analysed the lake water for
cations, anions, and isotopes. Our results show that the diatom assemblages
are strongly influenced by water depth and dominated by planktonic species,
i.e. Pliocaenicus bolshetokoensis. Species richness and diversity are higher in the northern part of the
lake basin, associated with the availability of benthic, i.e. periphytic,
niches in shallower waters. δ18Odiatom values are higher
in the deeper south-western part of the lake, probably related to water
temperature differences. The highest amount of the chironomid taxa
underrepresented in the training set used for palaeoclimate inference was
found close to the Utuk River and at southern littoral and profundal sites.
Abiotic sediment components are not symmetrically distributed in the lake
basin, but vary along restricted areas of differential environmental forcing.
Grain size and organic matter are mainly controlled by both river input and
water depth. Mineral (XRD) data distributions are influenced by the
methamorphic lithology of the Stanovoy mountain range, while elements (XRF)
are intermingled due to catchment and diagenetic differences. We conclude
that the lake represents a valuable archive for multiproxy environmental
reconstruction based on diatoms (including oxygen isotopes), chironomids, and
sediment–geochemical parameters. Our analyses suggest multiple coring
locations preferably at intermediate depth in the northern basin and the
deep part in the central basin, to account for representative bioindicator
distributions and higher temporal resolution, respectively.
Insights from mercury stable isotopes on terrestrial–atmosphere exchange of Hg(0) in the Arctic tundra
Authors: Jiskra Martin , Sonke Jeroen E. , Agnan Yannick , Helmig Detlev , Obrist Daniel
Published: October 2019

Abstract. The tundra plays a pivotal role in the Arctic mercury
(Hg) cycle by storing atmospheric Hg deposition and shuttling it to the
Arctic Ocean. A recent study revealed that 70 % of the atmospheric Hg
deposition to the tundra occurs through gaseous elemental mercury (GEM or Hg(0))
uptake by vegetation and soils. Processes controlling land–atmosphere
exchange of Hg(0) in the Arctic tundra are central, but remain
understudied. Here, we combine Hg stable isotope analysis of Hg(0) in the
atmosphere, interstitial snow air, and soil pore air, with Hg(0) flux
measurements in a tundra ecosystem at Toolik Field Station in northern
Alaska (USA). In the dark winter months, planetary boundary layer (PBL)
conditions and Hg(0) concentrations were generally stable throughout the day
and small Hg(0) net deposition occurred. In spring, halogen-induced
atmospheric mercury depletion events (AMDEs) occurred, with the fast
re-emission of Hg(0) after AMDEs resulting in net emission fluxes of Hg(0).
During the short snow-free growing season in summer, vegetation uptake of
atmospheric Hg(0) enhanced atmospheric Hg(0) net deposition to the Arctic
tundra. At night, when PBL conditions were stable, ecosystem uptake of
atmospheric Hg(0) led to a depletion of atmospheric Hg(0). The night-time
decline of atmospheric Hg(0) was concomitant with a depletion of lighter
Hg(0) isotopes in the atmospheric Hg pool. The enrichment factor,
ε202Hgvegetationuptake=-4.2 ‰ (±1.0 ‰) was consistent
with the preferential uptake of light Hg(0) isotopes by vegetation. Hg(0)
flux measurements indicated a partial re-emission of Hg(0) during daytime,
when solar radiation was strongest. Hg(0) concentrations in soil pore air
were depleted relative to atmospheric Hg(0) concentrations, concomitant with
an enrichment of lighter Hg(0) isotopes in the soil pore air, ε202Hgsoilair-atmosphere=-1.00 ‰
(±0.25 ‰) and E199Hgsoilair-atmosphere=0.07 ‰ (±0.04 ‰). These
first Hg stable isotope measurements of Hg(0) in soil pore air are
consistent with the fractionation previously observed during Hg(0) oxidation
by natural humic acids, suggesting abiotic oxidation as a cause for observed
soil Hg(0) uptake. The combination of Hg stable isotope fingerprints with
Hg(0) flux measurements and PBL stability assessment confirmed a dominant
role of Hg(0) uptake by vegetation in the terrestrial–atmosphere exchange of
Hg(0) in the Arctic tundra.
Phosphorus attenuation in streams by water-column geochemistry and benthic sediment reactive iron
Authors: Simpson Zachary P. , McDowell Richard W. , Condron Leo M.
Published: October 2019

Abstract. Streams can attenuate inputs of phosphorus (P) and, therefore the likelihood of ecosystem eutrophication. This attenuation is, however, poorly understood, particularly in reference to the geochemical mechanisms involved. In our study, we measured P attenuation mechanisms in the form of (1) mineral (co-)precipitation from the water-column and (2) P sorption with benthic sediments. We hypothesized that both mechanisms would vary with catchment geology and, further, that P sorption would depend on reactive Fe content in sediments. We sampled 31 streams at baseflow conditions, covering a gradient of P inputs (via land use), hydrological characteristics, and catchment geologies. Geochemical equilibria in the water-column were measured and benthic sediments ( 90 %) and varied with parent geology. Similarly, most sediment Fe was in a recalcitrant form (generally > 90–95 %). However, despite its small contribution to total sediment Fe, the pool of surface-reactive Fe was a strong predictor for sediment P sorption potential. Our results suggest that, in these streams, it is the combination of biogeochemical Fe and P cycles and the exchange with the hyporheic zone that attenuates DRP in baseflow. Such combinations are likely to vary spatiotemporally within a catchment and must be considered alongside inputs of P and sediment if the P concentrations at baseflow – and eutrophication risk – are to be well managed.
A Lagrangian convective transport scheme including a simulation of the time air parcels spend in updrafts (LaConTra v1.0)
Authors: Wohltmann Ingo , Lehmann Ralph , Gottwald Georg A. , Peters Karsten , Protat Alain , Louf Valentin , Williams Christopher , Feng Wuhu , Rex Markus
Published: October 2019

Abstract. We present a Lagrangian convective transport scheme developed for global chemistry and transport models, which considers the variable residence time that an air parcel spends in convection. This is particularly important for accurately simulating the tropospheric chemistry of short-lived species, e.g., for determining the time available for heterogeneous chemical processes on the surface of cloud droplets. In current Lagrangian convective transport schemes air parcels are stochastically redistributed within a fixed time step according to estimated probabilities for convective entrainment as well as the altitude of detrainment. We introduce a new scheme that extends this approach by modeling the variable time that an air parcel spends in convection by estimating vertical updraft velocities. Vertical updraft velocities are obtained by combining convective mass fluxes from meteorological analysis data with a parameterization of convective area fraction profiles. We implement two different parameterizations: a parameterization using an observed constant convective area fraction profile and a parameterization that uses randomly drawn profiles to allow for variability. Our scheme is driven by convective mass fluxes and detrainment rates that originate from an external convective parameterization, which can be obtained from meteorological analysis data or from general circulation models. We study the effect of allowing for a variable time that an air parcel spends in convection by performing simulations in which our scheme is implemented into the trajectory module of the ATLAS chemistry and transport model and is driven by the ECMWF ERA-Interim reanalysis data. In particular, we show that the redistribution of air parcels in our scheme conserves the vertical mass distribution and that the scheme is able to reproduce the convective mass fluxes and detrainment rates of ERA-Interim. We further show that the estimated vertical updraft velocities of our scheme are able to reproduce wind profiler measurements performed in Darwin, Australia, for velocities larger than 0.6 m s−1. SO2 is used as an example to show that there is a significant effect on species mixing ratios when modeling the time spent in convective updrafts compared to a redistribution of air parcels in a fixed time step. Furthermore, we perform long-time global trajectory simulations of radon-222 and compare with aircraft measurements of radon activity.
EXPLUME v1.0: a model for personal exposures to ambient O3 and PM2.5
Authors: Valari Myrto , Markakis Konstandinos , Powaga Emilie , Collignan Bernard , Perrussel Olivier
Published: October 2019

Abstract. This paper presents the first version of the regional scale personal exposure model EXPLUME. The model uses simulated gridded data of outdoor O3 and PM2.5 concentrations and several population and building-related datasets to simulate 1) space-time activity event sequences, 2) the infiltration of atmospheric contaminants indoors and 3) daily aggregated personal exposures. The model is applied over the greater Paris region at 2 km x 2 km resolution for the entire 2017 year. Annual averaged population exposures are discussed. We show that population mobility within the region, disregarding pollutant concentrations indoors, has only a small effect on average daily exposures. By contrast, considering the infiltration of PM2.5 in buildings decreases annual average exposure by 11 % (population average). Moreover, accounting for PM2.5 exposure during transportation (in-vehicle, while waiting on subway platforms, and while crossing on-road tunnels) increases average population exposure by 5 %. We show that the spatial distribution of PM2.5 and O3 exposures is similar to the concentration maps over the region, but the exposure scale is very different when accounting for indoor exposure. We model large intra-population variability in PM2.5 exposure as a function of the transportation mode, especially for the upper percentiles of the distribution. 20 % of the population using bicycles or motorcycles is exposed to annual average PM2.5 concentrations above the EU target value (25 µg/m3), compared to 0 % for people travelling by car. Finally, we develop a 2050–horizon projection of the building stock to study how changes in the buildings' characteristics to comply with the thermal regulations will affect personal exposures. We show that exposure to ozone will decrease by as much as 14 % as a result of this projection, whereas there is no significant impact on exposure to PM2.5.