bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of traditional authorities in local governance
Authors: Kangsangbata Christiana , Bugu Kendie Stephen
Published: March 2022

The role of traditional Authorities in local governance was the subject of the study. The research design consisted of various methods of data collection including in-depth face-to face interviews, document reviews and observations. One technique that was used throughout the research to get information from all traditional role players was the appreciative technique. The population was made up of opinion leaders, settlers, chiefs, fetish priests, identified group leaders, tengdamba (land owners), family heads and local government staff. The instruments were pretested for reliability The analysis consisted of describing qualitative data while quantitative data was analysed using SPSS (statistical package for social sciences). It emerged that traditional institutions have more good to offer the District Assembly in local governance than their limitation of the work of the Assembly. The institutions have remained resilient in the face of modern challenges because of the confidence and trust people have in them and are prepared to defend them. People perceive traditional authorities to present their history, norms, values and belief systems; it is believed society would get much more substantially than if they are excluded.
Customary land tenure, investments and livelihood adaptation in Northern Ghana
Authors: A. Yaro Joseph , Zackaria Abraham Ibn
Published: March 2022

The land tenure practice of any place is important for the economic well-being of its citizenry. This article assesses the investments of farmers on different categories of lands deemed to have less or more security in order to inform the debate on the relationship between tenure security and investments. We also delineate the changing livelihood portfolios of families resulting from changing access forms to land via livelihood adaptation. Quantitative data from a national survey conducted by the Institute of Statistical Social and Economic Research in addition to qualitative information from nine villages is used as evidence for the study. Investments in land tend to be constrained by a host of motivations and factors rather than just security. Poverty was the most important factor which prevented farmers from investing in a wide range of land improvements necessary for increasing productivity. As a result of pressure on land resources and scarcity of farmland in urban and pen-urban areas many, people are diversifying from agriculture to non-farm activities. In the rural areas, this pressure on land has led to migration by the youth to the cities and changes in land relations between land owners and other land users. The economic mix of northern Ghana is becoming complicated and in tune with global trends.' The deagrarianisation trend does not automatically lead to improvement in people's livelihoods but is contingent on social, economic and environmental factors.
Residents’ perceptions on the manifestation of the natural resource curse in the Tarkwa-Nsuaem Municipality, Ghana
Authors: Asamoah Yaw , Akyeampong Oheneba , Barima-Antwi Kwabena , Dauda Samuel
Published: March 2022

Natural resources have often been found to be a curse to some nations that possess them instead of being a blessing. In several developing economies, civil wars, environmental and health hazards have been associated with the extraction of such natural resources. This paper investigated residents' perceptions on the effects resultingfrom natural resource extraction in some mining communities in Ghana. Underpinned by the interpretivist philosophy, this case study employed in-depth interviews, focus group discussions and observation to collect data from the residents in Odumase and Teberebie communities in the Tarkwa-Nsuaem Municipality, in the Western Region of Ghana. Purposive and snowball sampling techniques were used to select 77 respondents for the study. Data collected was transcribed, coded into themes and categories, and manually analysed. The study found that the'mining communities were confronted with a number of environmental challenges, including pollution (air, water, soil, and noise), deforestation, abandoned mine pits and dumping of rock waste on fertile agricultural lands. Residents have become marginalized as a result of the difficulty to access potable drinking water, fertile agricultural lands and inability to come out of poverty since their livelihoods have become unsustainable. It is recommended that collaborative efforts should be adopted by various stakeholders to sustainably manage the exploitation of mineral resources. Central and local governments' policies and regulations regarding natural resource use, and n particular mining need to be enforced with local residents in mind.
Technical Note: Hardness, Corrosion Behavior, and Microstructural Characteristics of a Selective Laser Melted 17-4 PH Steel
Authors: Chaitanya P. , Goud R. , Raghavan R. , Ramakrishna M. , Prashanth K.G. , Gollapudi S.
Published: March 2022

In this work, we report the hardness and corrosion behavior of a selective laser melted 17-4 PH steel. Microstructure analysis using a scanning electron microscope (SEM) revealed a fine-grained material with a grain size of 1 μm. Phase analysis using SEM-EBSD (electron backscatter diffraction) revealed a ferritic-austenitic microstructure with 96% ferrite and 4% austenite. The material was also found to bear a combination of <001> and <111> fiber texture. The grain boundary character distribution revealed 68% low-angle grain boundaries, 10% CSL boundaries with predominantly Σ3 boundaries, and 21% high-angle grain boundaries. The Vickers hardness of this material was found to be quite high at 3.66±0.17 GPa which is probably due to the fine-grained structure of the material. Potentiodynamic polarization tests in 3.5 wt% NaCl solution yielded a corrosion current density, icorr of 1.4 × 10−6 A/cm2 and corrosion potential, Ecorr of −55 mVAg/AgCl electrode. Immersion tests in salt water for a period of 96 h showed hardly any pit formation although an AISI 304 stainless steel bearing grain size of 29 μm showed significant pit formation during the same time period.
Long Cervicothoracolumbal Rigid Bracing Stabilization on Incomplete Spinal Cord Injury of Post-Operated Multi-Focal Upper Cervical-Thoracic Spinal Tuberculosis: A Unique Case Report
Authors: Florencia Wirawan  , Ronald E. Pakasi  , Muthia Mukharoma  , Andre Maharadja
Published: March 2022

Background and aim: Spinal tuberculosis (STB) is a hazardous type of bone tuberculosis that could affect the entire spine, with predilection towards the lower thoracic level. Upper cervical spondylitis occurred only at 0.3 – 1% of all STB cases, but this rare type leads to severe consequences, including tetraplegia, autonomic dysfunction, and respiratory impairment. This case reported long CTLSO rigid external stabilisation reasoning to boost protection whilst recovering tuberculosis despite stable internal stabilisation. Methods: A 34-year-old male came with one year of worsening low-back pain, unintentional weight loss, and gradual loss of power and sensation of both feet within a month. Physical examination showed kyphotic deformity, tenderness, key-muscle-strength 3, and sensory impairment for lower extremities, with no autonomic disturbances. Laboratory works showed chronic ongoing infection. Whole-spine MRI showed multiple spondylodiscitis with multi-focal paravertebral abscesses at C3 – C5, C7 – T3, T9 – T12, L1, severe canal stenosis and anterior segment destruction of T12. Results: The patient was diagnosed with SCI AIS D with a neurological level of L3 secondary to T12 vertebra destruction from STB. He underwent abscess evacuation, debridement, and posterior stabilisation at T10 – L3 and debridement of abscess at C3 – C5 without the need for stabilisation. After procedures, the spine was further stabilised by a CTSLO brace with flexion, extension, lateral flexion, rotation stop. Inward rehabilitation includes incremental mobilisation, upper-limb-extensor-group-strengthening-programme, balance-exercise with ambulation training. Patient discharged with status: ambulate independently with a walker. To date, the patient has returned to work with independent ambulation. Conclusion: Type-III STB was indicated for surgical procedures. Instability of upper cervical prevented patient to performed loadbearing activity thus lowering patient functional outcomes. CTLSO supplementation was given to compensate for 3 lesion sites, the upper cervical, mid-thoracic, and lower-thoracic. For the C3 – C5 lesion, there was no internal stabilisation, so a proper external mode of stabilisation should be given. However, for the thoracic level, CTLSO was given due to (1) incomplete SCI lesion in the absence of deteriorating neurological deficit,c(2) porous nature of STB, and (3) good prognostic recovery of STB with anti-TB medication leading to the reversible neurological deficit.
A Pinch of Salt Won’t Kill: The Role of Salt Tablets in Reversing Intractable Orthostatic Hypotension in an Incomplete Tetraplegic Patient
Authors: Muhamad Faizal Zainudin  , Alicia Dixie Abraham  , Mohd Razali Hasim  , Nurul Diyanah Zenian
Published: March 2022

Background and aim: Orthostatic hypotension is a known complication of spinal cord injury, especially in individuals with tetraplegia and thoracic paraplegia. It is triggered by tilting the patient upright and often easily reversed by removing the precipitating factors. The salt tablet is an old medical supplement that works as a blood volume expander by retaining water. We present a case of intractable orthostatic hypotension in incomplete tetraplegia, which resolved after the initiation of salt tablets. Methods: The patient was a 58-year-old gentleman with background hypertension who presented with neck pain following an aggressive neck massage, associated with progressive limb weakness, for six days duration. He developed urinary and bowel retention one day before the presentation. Urgent MRI scan revealed blunt injury at cervical spine with contusion of the cervical spinal cord, epidural haematoma, and contusion of prevertebral soft tissue from C4 till C6 spinal level. He was treated conservatively with steroids. In the rehabilitation ward, the patient developed multiple syncopal episodes during tilt table exercises. The perpetuating factors were antihypertensive medications, anaemia, and urinary tract infection, which resulted in polyuria and electrolyte imbalances. The orthostatic hypotension persisted, despite optimising fluid intake, treating underlying medical issues, removing triggers, and adopting additional measures such as abdominal binder and elastic stockings. Results: Following the initiation of salt tablets 1 gram TDS, the syncopal attacks gradually resolved. The patient tolerated the tilt table exercises until 90° elevation and subsequently progressed into sitting in the wheelchair for an extended period. The patient was completely free of syncope at discharge and required minimal assistance to perform stand transfer to the wheelchair. Conclusion: Orthostatic hypotension is a treatable barrier to progress in spinal cord injury rehabilitation. Therefore, simple, cheap, and easily accessible treatment options such as salt tablets should be considered in intractable cases.
Performing Solat in Spinal Cord Injury Patients: Challenges and Solutions
Authors: Siti Nur Hidayah Sudin  , Mira Farhana Yaacob  , Siti Suhaida Sudin  , Yusniza Mohd Yusof
Published: March 2022

Background and aims: Solat (Islamic prayer) is the second pillar of Islam. Solat is performed at five appointed times in a day as commanded in the Quran, “Verily, Solat is an obligation on the believers to be observed at its appointed time” (Qur’an 4: 10). Muslims who preserved their solat show high levels of spirituality which correlated with enhanced quality of life and well-being, also lower levels of depression and psychological stress. However, from our experience, spinal cord injury (SCI) patients face many limitations to perform solat. Methods: An 18-year-old Malay lady with underlying follicular thyroid carcinoma and T-lymphoblastic lymphoma. She underwent multiple chemotherapies, which were complicated with transverse myelitis resulting in an incomplete paraplegia L2 level. She has a neurogenic bladder on the indwelling catheter, unregulated neurogenic bowel, and impaired mobility. She has good faith in Allah and had good compliance to solat before the illness. Results: Since being diagnosed in 2018, she unintentionally did not perform solat due to limited mobility to go to the bathroom for ablution. She also misunderstood that solat cannot be performed with an indwelling catheter and pampers in situ. She was unsure how to perform solat if unable to stand, lacked confidence with wheelchair hygiene, and thought that solat was not compulsory due to her illness. Some patients did not perform solat due to emotional or psychological issues such as anger toward God. However, this is not the issue with her, as her Spiritual Injury Scale was normal. Conclusion: It is essential to educate healthcare workers to identify the limitations/ out of norm/ rukhsah/ leniency in Islam related to solat and understand the conditions of the validity of solat. This is to equip patients with the knowledge and ensure they are well guided on performing solat. Education and reaffirmation of the modified way of performing solat among SCI patients will normalise their new norm.
Fleet Enema-Induced Autonomic Dysreflexia in a Spinal Cord Injured Patient
Authors: Anis Afikah Ismail  , Muhammad Hafiz Hanafi  , Al Hafiz Ibrahim
Published: March 2022

Background and aim: Autonomic dysreflexia (AD) is an uncommon yet life-threatening and preventable condition. AD classically presents with hypertension, headache, bradycardia, flushing of the face, diaphoresis, malaise, nausea, and blurring of vision. One of the trigger factors is the neurogenic bowel. This clinical report highlights the use of fleet enema in spinal cord injured patients that can cause autonomic response and lead to severe complications. Methods: A 33-year-old man with 3 months post-traumatic Cervical 5 AIS (American Spinal Injury Association) B was admitted for active rehabilitation. Despite the use of tablet Bisacodyl, his neurogenic bowel remains unregulated. Consequently, he was given a fleet enema for bowel programme management and successfully been regulated. On the next bowel day, he presented with sudden onset of blurring of vision and light-headedness after given fleet enema, accompanied by marked elevation of blood pressure, ranging from 130 – 140/ 90 – 100 mmHg (baseline during admission 80 – 90/ 50 – 60 mmHg) with a heart rate 50 – 60 bpm. The condition worsened as 20 minutes later, he developed a sudden generalised tonic-clonic seizure for 10 seconds, which aborted spontaneously. Results: Pre-ictal blood pressure significantly showed a more significant rise in the SBP, up to 40 mmHg. Computed tomography (CT) brain revealed no abnormality. A series of infection markers pre- and post-event showed normal value. However, the result of metabolic level post-event appeared to be higher in phosphate level 1.80 mmol/L, low calcium level 2.0 mmol/L, and borderline high level of sodium 146 mmol/L. Conclusion: This case illustrates the usage of fleet enema can cause AD, as it has been reported that it may irritate the bowel. Hence, a seizure is also a part of AD complications. On top of that, it also led to an electrolytes imbalance which triggered the seizure. Fleet enema, which contains monobasic sodium phosphate, may result in electrolytes imbalances such as hyperphosphataemia, hypernatraemia, and hypocalcaemia. This needs to be highlighted the proper use of fleet enema in neurogenic bowel management.
Treatment of acute respiratory failure: invasive mechanical ventilation
Authors: Kim Young Sam
Published: March 2022

Background: Acute respiratory failure is a condition in which gas exchange functions decrease due to various causes. Respiratory failure is one of the most common causes of intensive care unit admissions, and most cases require invasive mechanical ventilation.Current Concepts: Invasive mechanical ventilation is defined as the delivery of positive pressure to the lungs via an endotracheal or tracheostomy tube. Invasive mechanical ventilation is commonly used to replace the functions of spontaneous breathing, either fully or partially, by performing the breathing function for the lungs. It is also indicated in patients who require airway protection or have neuromuscular diseases. Invasive mechanical ventilation should not be delayed until the need becomes urgent. There is no universal set of ventilation protocols established as ideal for all patients. It is essential that doctors understand and apply the necessary methods to protect the lungs from injury associated with invasive mechanical ventilation.Discussion and Conclusion: The primary goals of mechanical ventilation are to optimize oxygenation while avoiding ventilator-induced lung injury. In patients with acute respiratory failure, the mortality rate has reduced dramatically with the application of the lung-protective ventilation strategy. Patients undergoing invasive mechanical ventilation will survive if they are treated and monitored according to this principle, but damage to the lungs may occur if the guidelines are not followed. Therefore, it is essential to know and adhere to the initial setup and monitoring principles.
Development of a graphical model of causal gene regulatory networks using medical big data and Bayesian machine learning
Authors: Park Sung Bae , Yoo Changwon
Published: March 2022

Background: Data collection from medicine and biomedical science is becoming a large task and increasingly complicated with each passing day. Machine learning methods have been applied to elucidate interactions between genes and genes and their environment.Current Concepts: Many machine learning methods have been used to determine the statistical meaning or relationship in the prediction or progression of diseases through the creation of causal networks based on medical big data. Through these analyses, the occurrence and progression of diseases have been shown to be related to several genes and environmental factors. However, these methods cannot identify the key upstream regulators inferred from genomic, clinical, and environmental medical data.Discussion and Conclusion: The causal Bayesian network (CBN) is a machine learning method that can be used to understand a causal network inferred from the gene expression data. The CBN can help identify the key upstream regulators through examining the causal network inferred from medical big data having genomic information. We can easily improve the clinical outcome through regulation of these identified key upstream factors. Therefore, the CBN may be a powerful and flexible tool in the era of precision medicine.
The creation of the UTS Social Impact Framework: A collaborative approach for transformational change
Authors: Gusheh Mitra , Firth Verity , Netherton Clare , Pettigrew Claire
Published: March 2022

The relationship between education and public purpose has been historical and remains fundamental to the core mission of the higher education sector. Alongside the growth of engaged scholarship and practice, increasing and, at times, competing forces work to influence institutional focus and direction. Key amongst these are global university ranking systems, which have begun to shift their gaze beyond traditional notions of academic excellence to also consider impact and engagement. The tension between external and internal drivers for social engagement can fragment institutional focus and undermine community impact. In the face of this challenge, holistic institutional frameworks that systemically and culturally underpin, enable and make inherent engaged scholarship remain scarce. Their absence risks marginalising engaged university practice, teaching and research, thereby limiting the potential impact of universities.

This article aims to address this gap in the literature by examining the question of how universities can create a whole-of-institution approach to their public purpose agenda. Using the University of Technology Sydney as a case, the development of the UTS Social Impact Framework is shared here. We detail the use of Appreciative Inquiry and Theory of Change as underpinning participatory methodologies that have resulted in a systems approach to change, based on institutional strengths. The resulting framework articulates a shared vision and outlines a guiding roadmap encompassing six domains of change, expressed as outcomes, and an additional three preconditions. Woven together, these create a robust image of the systemic and cultural dynamics needed to realise the shared vision of the university, ensuring that contribution to social outcomes remains a core mission of this higher education institution. The adopted approach used in this study can inform the development of contextually relevant frameworks across the sector, with potential to reposition engagement, beyond an aspect of practice, as a systemic precondition that enables broader social change.
Emerging organoid-based platforms to study salivary gland hypofunction
Authors: Seo Yoojin , Kim Hyung-Sik
Published: March 2022

Xerostomia is a pathologic condition of hyposalivation due to salivary gland (SG) dysfunction. Although xerostomia significantly affects the quality of patients’ life, there is no satisfactory treatment for this disease. Importantly, the senior population is more susceptible to xerostomia than younger individuals and the prevalence of the disease is much higher in elderly women than in men. However, the mechanisms underlying these clinical correlations have not yet been elucidated and further studies are required. Given that cell lines exhibiting saliva-producing abilities are not available, the generation and maturation of salivary gland organoids (SGOs) have been spotlighted as a modeling system to investigate the homeostasis of SG stem cells, as well as the pathophysiology of SGs in disease. In this review article, we will review the latest reports dealing with the generation and maturation of SGOs by defining the stem cells in SGs. We will also discuss the recent literature proposing strategies to model disease and regenerate damaged tissues.
VIDEO PEMBELAJARAN SEBAGAI DOKUMEN DIGITAL GURU DI SMP NEGERI 2 TANAH SIANG
Authors: ANGGRAINI DIAN
Published: March 2022

The COVID-19 pandemic that occurred in Indonesia has changed the learning system that was originally face-to-face to a combination with virtual face-to-face. This is of course very influential on learning in schools which have undergone very drastic changes. One of the learning media that can help support face-to-face learning activities is video learning. The research method used by the researcher is a literature study which collects all related information from journals, books, learning models, and others. Literature study of several research results shows that the use of learning videos is very effective in helping to provide understanding to students and can be repeated at home if there is material that is not clear.
ABSTRAKPandemi covid 19 yang terjadi di Indonesia telah mengubah system pembelajaran yang awalnya tatap muka menjadi kombinasi dengan tatap maya. Hal ini tentunya sangat berpengaruh terhadap pembelajaran di sekolah yang mengalami perubahan sangat drastis. Salah sau media pembelajaran yang dapat membantu dalam menunjang kegiatan pembelajarann secara tatap maya adalah video pembelajaran. Metode penelitian yang digunakan oleh peneliti adalah studi literature dimana mengumpulkan semua informasi terkait baik dari jurnal, buku, model belajar, dan lain-lain. Studi literatur terhadap beberapa hasil penelitian menunjukkan bahwa penggunaan video pembelajaran sangat efektif dalam membantu memberi pemahaman kepada peserta didik dan bisa diulang Kembali di rumah apabila ada materi yang tidak jelas.
O ACESSO À EDUCAÇÃO SUPERIOR PÚBLICA NO BRASIL SOB ÓTICA DOS DADOS NACIONAIS
Authors: Malange Fernando Cezar Vieira , Nogueira Patricia Simone , Zardo Luiz André Ribeiro
Published: March 2022

O texto tem por objetivo avaliar indicadores produzidos a partir de dados do Censo da Educação Superior na perspectiva do acesso à Educação Superior Pública no Brasil. Para essa análise utilizou-se os indicadores definidos por Silva e Veloso (2013), que estabelecem para as dimensões do acesso os seguintes indicadores: Dimensão do Ingresso – indicadores - vagas, ingressos e formato seletivo; Dimensão da permanência – matrículas – taxa de trancamento e taxa de conclusão. No que refere as vagas, inscritos e ingressos, entre os anos de 2010 e 2019, houve aumento de vagas foi de cerca de 23,2%, de 75,8% no número de candidatos inscritos, e consequentemente uma maior relação candidato/vaga, e de 15,3% de ingressantes. Observa-se que as matrículas se concentraram na modalidade de ensino presencial, com cerca de 6,1 milhões de matrículas ofertadas nesta modalidade. Das cerca de 2,1 milhões as matrículas ocorridas na rede pública, em torno de 1,5 milhões dessas matrículas não estiveram vinculadas a programas de reserva de vagas. Entre as matrículas de estudantes que ingressaram por meio de reserva de vagas, verifica-se que apenas cerca de 32,0% estavam relacionadas a estudantes que participam de algum tipo de apoio social.  Entre os estudantes que ingressaram por meio de ampla concorrência, 15,4% dos estudantes participaram de algum tipo de apoio social.  As políticas públicas instituídas possibilitaram o ingresso de estudantes das escolas públicas e com vulnerabilidade social, entretanto as ações e programas ainda não afirmam a permanência nas instituições de educação superior com o objetivo de conclusão dos cursos.
TERRITÓRIOS DO CURRÍCULO POR ÁREAS DE CONHECIMENTO NA LICENCIATURA EM EDUCAÇÃO DO CAMPO
Authors: Hage Salomão Mufarrej , Barros Oscar Ferreira , Silva Hellen Do Socorro de Araújo
Published: March 2022

O artigo apresenta reflexões sobre o currículo e a formação de educadores no Curso de Licenciatura em Educação do Campo ofertado pela UFPA no Campus de Cametá, analisando o currículo em meio à disputa de territórios: o de colonialidades e reformas empresarias e os territórios de luta, raizistência e afirmação territorial amazônica, no âmbito da formação de educadores. Ancora-se na Epistemologia da Decolonialidade como paradigma de subversão e desobediência política, social e epistêmica ao padrão de poder moderno norte-eurocêntrico do capitalismo e das colonialidades do poder, ser, saber e natureza. Em seus resultados, privilegia o contraste entre o currículo imposto à formação de educadores no atual contexto político necrófilo, misantrópico e entrópico, diante do padrão mercadológico e empresarial que se impõem à educação pública; e o currículo do Curso de Licenciatura em Educação do Campo que se territorializa em meio à interação e diálogos entre os conhecimentos científicos e os saberes tradicionais, mediados pela alternância pedagógica e pelas lutas camponesas, quilombolas e ribeirinhas que se realizam nos fóruns de educação do campo.
Comparing different methods for one-mode homogeneity blockmodeling according to structural equivalence on binary networks
Authors: Žiberna Aleš
Published: March 2022

One-mode homogeneity blockmodeling is an approach to clustering networks that searches for partitions of units in a network so that the resulting blocks are as homogeneous as possible. Block is a part of the network that contain (possible) ties from the units of one cluster to the units of another cluster (or ties within a cluster). Typically, sum of squared deviations from the mean is taken as the measure of variability (non-homogeneity). The paper presents the results of a simulation study that applied several methods for this problem to binary networks generated according to structural equivalence. Several versions of homogeneity generalized blockmodeling (using a relocation algorithm), a k-means-based algorithm, and an indirect approach are compared. Since all of the methods being compared try to optimize the same criterion function, this and the Adjusted Rand Index are the main criteria for the comparison. All methods (except the indirect approach, which is not iterative) were given the same amount of time to find the best possible solution. The overall conclusion is that the k-means approach is advised in most cases, except when smaller networks (200 units) are being partitioned into larger number of clusters, in which case the homogeneity generalized blockmodeling is preferred.
Comparison of particle number size distribution trends in ground measurements and climate models
Authors: Leinonen Ville , Kokkola Harri , Yli-Juuti Taina , Mielonen Tero , Kühn Thomas , Nieminen Tuomo , Heikkinen Simo , Miinalainen Tuuli , Bergman Tommi , Carslaw Ken , Decesari Stefano , Fiebig Markus , Hussein Tareq , Kivekäs Niku , Kulmala Markku , Leskinen Ari , Massling Andreas , Mihalopoulos Nikos , Mulcahy Jane P. , Noe Steffen M. , van Noije Twan , O'Connor Fiona M. , O'Dowd Colin , Olivie Dirk , Pernov Jakob B. , Petäjä Tuukka , Seland Øyvind , Schulz Michael , Scott Catherine E. , Skov Henrik , Swietlicki Erik , Tuch Thomas , Wiedensohler Alfred , Virtanen Annele , Mikkonen Santtu
Published: March 2022

Abstract. Despite a large number of studies, the effect of aerosols has the largest uncertainty in global climate model radiative forcing estimates. There have been studies of aerosol optical properties in climate models, but the effects of particle number size distribution need a more thorough inspection. We investigated the trends and seasonality of particle number concentrations in different sizes in total of for 21 measurement sites in Europe and Arctic. For 13 of those, with longer measurement time series, we compared the field observations with the results from five climate models, namely EC-Earth3, ECHAM-M7, ECHAM-SALSA, NorESM1.2, and UKESM1. This is the first extensive comparison of detailed aerosol size distribution trends between in-situ observations from Europe and five earth system models (ESM). We found that the trends of particle number concentrations were mostly consistent and decreasing in both, measurements and models. However, for many sites, climate models showed weaker decreasing trends than the measurements. Seasonal variability in measured number concentrations, quantified by the ratio between maximum and minimum monthly number concentration, were typically stronger in northern measurement sites compared to other locations. Models had large differences in their seasonal representation, and they can be roughly divided into two categories. For EC-Earth and NorESM, the seasonal cycle was relatively similar for all sites, for others, the pattern of seasonality varied between northern and southern sites. In addition, the variability in concentrations across sites varied between models, some having relatively similar concentrations for all sites, whereas others showing clear differences in concentrations between remote and urban sites. To conclude, although anthropogenic mass emissions are harmonized in models, trends in different sized particles vary among the model due to assumptions in emission sizes and differences in how models treat size dependent aerosol processes. The inter-model variability was largest in the accumulation mode, i.e. sizes which have implications for aerosol-cloud interactions.
The impact of peripheral circulation characteristics of typhoon on sustained ozone episodes over the Pearl River Delta region, China
Authors: Li Ying , Zhao Xiangjun , Deng Xuejiao , Gao Jinhui
Published: March 2022

Abstract. The peripheral circulation of typhoon forms sustained
ozone episodes. However, how it impacts the day-to-day ozone pollution
levels during the episodes has not been clearly studied, which is crucial
for better prediction of the daily ozone variation. In this study, the
analysis of ground observation, wind profile data, and model simulation is
integrated. By analysing the wind profile radar observations, we found a
weak wind deepening (WWD; vertical depth of the weak winds increased), more
correlated with the ground-level ozone variation than surface weak wind.
Long-term statistical analyses showed that the WWD is a common weather
phenomenon in the peripheral subsidence region of typhoons and is generally
accompanied by ozone pollution episodes. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) with process analysis
simulation showed that the peripheral subsidence chemical formation (CHEM)
and vertical mixing (VMIX) effects are two major contributors to the
enhancement of ozone levels to form the episode, while the advection (ADV)
showed negative values. However, the day-to-day variation of the daytime
ozone levels during the episode is not determined by the daily variation of
daytime CHEM and VMIX but is dominated by the ADV terms. Therefore, the ozone
and its precursors accumulation, including the enhancement during the
night-time, contribute to the daytime ozone increase in the following day. A
detail day-to-day process analysis showed that in additional to decrease of
negative ADV values (e.g. the weakened advection outflow or dispersion) on
the ground, the integrated effect of the daily variation of the accumulative
CHEM and ADV above the ground throughout the planetary boundary layer (PBL) together determined the
overall day-to-day daytime ozone variation on the ground through the VMIX
process. The results indicate that the peripheral characteristics of
approaching typhoon not only form the ozone episode by the enhanced
photochemical reactions, but also could increase the day-to-day daytime ozone
levels via pollution accumulation throughout the PBL due to the WWD up to
3–5 km. These results illustrate the important role of the WWD in the lower
troposphere for the formation of sustained ozone episodes due to the
peripheral circulation of the typhoon, which helps to better predict the
daily changes of daytime ozone levels.
Influence of total ozone column (TOC) on the occurrence of tropospheric ozone depletion events (ODEs) in the Antarctic
Authors: Cao Le , Fan Linjie , Li Simeng , Yang Shuangyan
Published: March 2022

Abstract. The occurrence of tropospheric ozone depletion events (ODEs) in the Antarctic can be influenced by many factors, such as the total ozone column (TOC). In this study, we analyzed the observational data obtained from ground observation stations and used two numerical models (TUV and KINAL), to discover the relationship between the TOC and the occurrence of ODEs in the Antarctic. A sensitivity analysis was also performed on ozone and major bromine species (BrO, HOBr and HBr) to find out key photolysis reactions determining the impact on the occurrence of tropospheric ODEs brought by TOC. From the analysis of the observational data and the numerical results, we suggest that the occurrence frequency of ODEs in the Antarctic is negatively associated with TOC, after screening out the impact on ODEs caused by the solar zenith angle (SZA). This negative impact of TOC on the occurrence of ODEs was suggested to be exerted through altering the solar radiation reaching the ground surface and changing the rates of photolysis reactions. Moreover, major ODE accelerating reactions (i.e., photolysis of tropospheric ozone, H2O2 and HCHO) and decelerating reactions (i.e., photolysis of BrO and HOBr), which heavily control the start of ODEs, were also identified. We found that when TOC decreases, the major ODE accelerating reactions significantly speed up. In contrast, the major ODE decelerating reactions are only slightly affected. As a result of the different impacts of TOC on photolysis reactions, the occurrence of ODEs depends negatively on TOC.
Assessing vehicle fuel efficiency using a dense network of CO2 observations
Authors: Fitzmaurice Helen L. , Turner Alexander J. , Kim Jinsol , Chan Katherine , Delaria Erin R. , Newman Catherine , Wooldridge Paul , Cohen Ronald C.
Published: March 2022

Abstract. Transportation represents the largest sector of anthropogenic
CO2 emissions in urban areas in the United States. Timely reductions in
urban transportation emissions are critical to reaching climate goals set by
international treaties, national policies, and local governments.
Transportation emissions also remain one of the largest contributors to both
poor air quality (AQ) and to inequities in AQ exposure. As municipal and
regional governments create policy targeted at reducing transportation
emissions, the ability to evaluate the efficacy of such emission reduction
strategies at the spatial and temporal scales of neighborhoods is
increasingly important; however, the current state of the art in emissions
monitoring does not provide the temporal, sectoral, or spatial resolution
necessary to track changes in emissions and provide feedback on the efficacy
of such policies at the abovementioned scale. The BErkeley Air Quality and
CO2 Network (BEACO2N) has previously been shown to provide constraints on emissions from the vehicle sector in aggregate over a
∼ 1300 km2 multicity spatial domain. Here, we focus on a
5 km, high-volume, stretch of highway in the San Francisco Bay Area. We show that inversion of the BEACO2N measurements can be used to understand two
factors that affect fuel efficiency: vehicle speed and fleet composition.
The CO2 emission rate of the average vehicle (in grams per vehicle kilometer) is shown to vary by as much as 27 % at different times of a typical weekday because of
changes in these two factors. The BEACO2N-derived emission estimates
are consistent to within ∼ 3 % of estimates derived from
publicly available measures of vehicle type, number, and speed, providing
direct observational support for the accuracy of the EMission FACtor model (EMFAC) of vehicle fuel efficiency.
Variability and Uncertainty in Flux-Site Scale Net Ecosystem Exchange Simulations Based on Machine Learning and Remote Sensing: A Systematic Evaluation
Authors: Shi Haiyang , Luo Geping , Hellwich Olaf , Xie Mingjuan , Zhang Chen , Zhang Yu , Wang Yuangang , Yuan Xiuliang , Ma Xiaofei , Zhang Wenqiang , Kurban Alishir , De Maeyer Philippe , Van de Voorde Tim
Published: March 2022

Abstract. Net ecosystem exchange (NEE) is an important indicator of carbon cycling in terrestrial ecosystems. Many previous studies have combined flux observations, meteorological, biophysical, and ancillary predictors using machine learning to simulate the site-scale NEE. However, systematic evaluation of the performance of such models is limited. Therefore, we performed a meta-analysis of these NEE simulations. Total 40 such studies and 178 model records were included. The impacts of various features throughout the modeling process on the accuracy of the model were evaluated. Random Forests and Support Vector Machines performed better than other algorithms. Models with larger time scales have lower average R-squared, especially when the time scale exceeds the monthly scale. Half-hourly models (average R-squared = 0.73) were significantly more accurate than daily models (average R-squared = 0.5). There are significant differences in the predictors used and their impacts on model accuracy for different plant functional types (PFT). Studies at continental and global scales (average R-squared = 0.37) with multiple PFTs, more sites, and a large span of years correspond to lower R-squared than studies at local (average R-squared = 0.69) and regional scales (average R-squared = 0.7). Also, the site-scale NEE predictions need more focus on the internal heterogeneity of the NEE dataset and the matching of the training set and validation set. The results of this study may also be applicable to the prediction of other carbon fluxes such as methane.
Discontinuity of the concentration and composition of dissolved organic matter at the peat-pool interface in a boreal peatland
Authors: Prijac Antonin , Gandois Laure , Jeanneau Laurent , Taillardat Pierre , Garneau Michelle
Published: March 2022

Abstract. Pools are common features of peatlands and can represent from 5 to 50 % of the peatland’s surface area. They play an important role in the peatland carbon cycle by emitting carbon from their surfaces to the atmosphere. However, the origin of this carbon is not well known. A hypothesis is that carbon emitted from pools is the product of mineralised peat-derived dissolved organic matter (DOM). To test this hypothesis, this study examined the origins, compositions, and degradability of DOM in peat porewaters and peat pools within an ombrotrophic boreal peatland in northeastern Québec (Canada) for two years during the growing season. The temporal evolutions of dissolved organic carbon (DOC) concentrations, the optical properties, molecular compositions (TMH-GC-MS), stable isotopic signatures (δ13C-DOC), and degradability of DOM were determined. This study demonstrates that DOM is a complex and highly dynamic component of peatland ecosystems. If the molecular analyses reveal that DOM in porewaters and pools share a common vegetation origin, the compositions of the DOM in the two environments are markedly different. Peat porewater DOM is more aromatic, with a higher molecular weight DOC : DON ratio. The temporal dynamics of DOC concentrations and DOM compositions also differ. In peat porewaters, the DOC concentrations followed a strong seasonal increase from 9 mg L-1, reaching a plateau above 20 mg L-1 in summer and autumn. This is best explained by seasonal vegetation productivity, which is greater than DOM degradation through microbial activity. In pools, DOC concentrations also increased but remained two times lower than in the peat porewaters at the end of the growing season with an average concentration of 10 mg L-1. Those differences might be explained by a combination of physical, chemical, and biological factors. The limited hydraulic conductivity in deeper peat increased the DOM residence time in peat. This might favour both DOM microbial transformation within the peat and the interaction of DOM aromatic compounds with the peat matrix, explaining part of the shift of DOM compositions between peat porewaters and pools. The DOM might be even further transformed at the interface between peat and pools with the production of low molecular weight compounds. This study could not highlight any photolability of DOM and only limited microbial degradability. We estimate that the carbon emissions related to DOM transformation in peatland pools could represent from 4.2 to 8.7 % of the long-term apparent rate of carbon accumulation.
Ab initio thermal expansion and thermoelastic properties of ringwoodite (γ-Mg2SiO4) at mantle transition zone conditions
Authors: Belmonte Donato , La Fortezza Mattia , Menescardi Francesca
Published: March 2022

Abstract. Thermal convection in the Earth's mantle is driven by lateral variations in temperature and density, which are substantially controlled by the local volume thermal expansion of the constituent mineral phases. Ringwoodite is a major component of the lower mantle transition zone, but its thermal expansivity and thermoelastic properties are still affected by large uncertainties. Ambient thermal expansion coefficient (αV0​​​​​​​), for instance, can vary as much as 100 % according to different experimental investigations available from the literature. In this work, we perform ab initio density functional theory calculations of vibrational properties of spinel-structured Mg2SiO4 ringwoodite in order to provide reliable thermophysical data up to mantle transition zone conditions. Temperature- and pressure-dependent thermal expansivity has been obtained by phonon dispersion calculations in the framework of quasi-harmonic approximation (QHA) up to 25 GPa and 2000 K. Theoretical analysis of vibrational spectra reveals that accurate prediction of IR and silent modes, along with their relative mode Grüneisen parameters, is crucial to define thermal expansivity. A six-parameter analytical function is able to reproduce ab initio values fairly well in the whole investigated P–T range, i.e., αV(P,T)=(1.6033×10-5+8.839×10-9T+11.586×10-3T-1-6.055T-2+804.31T-3) ×exp⁡(-2.52×10-2P), with temperature in kelvin and pressure in gigapascal. Ab initio static and isothermal bulk moduli have been derived for ringwoodite along with their P, T and cross derivatives, i.e., K0 = 184.3 GPa, KT,300 K = 176.6 GPa, K0′ = 4.13, KT,300K′ = 4.16, ∂KT∂TP = −0.0233 GPa K−1 and ∂2KT∂P∂T0=1.0×10-4 K−1. Computed thermal expansivity and thermoelastic properties support the evidence that QHA performs remarkably well for Mg2SiO4 ringwoodite up to mantle transition zone temperatures. Since volume thermal expansion of ringwoodite is strongly pressure-dependent and its pressure dependence becomes more marked with the increasing temperature, internally consistent assessments and empirical extrapolation of thermoelastic data to deep mantle conditions should be taken with care to avoid inaccurate or spurious predictions in phase equilibrium and mantle convection numerical modeling.
Harmonized chronologies of a global late Quaternary pollen dataset (LegacyAge 1.0)
Authors: Li Chenzhi , Postl Alexander K. , Böhmer Thomas , Cao Xianyong , Dolman Andrew M. , Herzschuh Ulrike
Published: March 2022

Abstract. We present a chronology framework named LegacyAge 1.0
containing harmonized chronologies for 2831 pollen records (downloaded from
the Neotoma Paleoecology Database and the supplementary Asian datasets)
together with their age control points and metadata in machine-readable data
formats. All chronologies use the Bayesian framework implemented in Bacon
version 2.5.3. Optimal parameter settings of priors (accumulation.shape,
memory.strength, memory.mean, accumulation.rate, and thickness) were identified
based on information in the original publication or iteratively after
preliminary model inspection. The most common control points for the
chronologies are radiocarbon dates (86.1 %), calibrated by the latest
calibration curves (IntCal20 and SHCal20 for the terrestrial radiocarbon
dates in the Northern Hemisphere and Southern Hemisphere and Marine20 for marine
materials). The original publications were consulted when dealing with
outliers and inconsistencies. Several major challenges when setting up the
chronologies included the waterline issue (18.8 % of records), reservoir effect (4.9 %), and sediment deposition discontinuity (4.4 %). Finally, we numerically compare the LegacyAge 1.0 chronologies to those published in the original publications and show that the reliability of the chronologies of 95.4 % of records could be improved according to our assessment. Our chronology framework and revised chronologies provide the opportunity to make use of the ages and age uncertainties in synthesis studies of, for example, pollen-based vegetation and climate change. The LegacyAge 1.0 dataset, including metadata, datings, harmonized chronologies, and R code used, is open-access and available at PANGAEA (https://doi.org/10.1594/PANGAEA.933132; Li et al., 2021) and Zenodo (https://doi.org/10.5281/zenodo.5815192; Li et al., 2022), respectively.
Constraint-following control design for the position tracking of a permanent magnet linear motor with inequality constraints
Authors: Chen Xiaofei , Zhao Han , Zhen Shengchao
Published: March 2022

Abstract. In this paper, we mainly solve the problem of the trajectory following the control and boundary transfinite control of the permanent magnet linear motor (PMLM). Using the Udwadia–Kalaba (U–K) method, the explicit equation of the complete nonholonomic constraint equation is
first established, and then the new input constraint equation is obtained by integrating the inequality constraint and the original equation constraint through tangent-state transformation mapping. This constraint equation can make the motor move along the ideal trajectory in a limited range, thus solving the control problem of equality and inequality creatively. The simulation results and PMLM experiment results, based on control Signal Processing And Control Engineering (cSPACE), show that the proposed control method can obtain better motion performance, and the motion displacement does not exceed the boundary while satisfying the trajectory tracking control performance, which proves the effectiveness and feasibility of the proposed method.