bluuebunny/crossref_metadata_2025 huggingface dataset:
Unraveling the physiological responses of morphologically distinct corals to low oxygen
Authors: Long Ying , Sinutok Sutinee , Buapet Pimchanok , Yucharoen Mathinee
Published: September 2024

Background

Low oxygen in marine environments, intensified by climate change and local pollution, poses a substantial threat to global marine ecosystems, especially impacting vulnerable coral reefs and causing metabolic crises and bleaching-induced mortality. Yet, our understanding of the potential impacts in tropical regions is incomplete. Furthermore, uncertainty surrounds the physiological responses of corals to hypoxia and anoxia conditions.

Methods

We initially monitored in situ dissolved oxygen (DO) levels at Kham Island in the lower Gulf of Thailand. Subsequently, we conducted a 72-hour experimental exposure of corals with different morphologies—Pocillopora acuta, Porites lutea, and Turbinaria mesenterina—to low oxygen conditions, while following a 12/12-hour dark/light cycle. Three distinct DO conditions were employed: ambient (DO 6.0 ± 0.5 mg L−1), hypoxia (DO 2.0 ± 0.5 mg L−1), and anoxia (DO < 0.5 mg L−1). We measured and compared photosynthetic efficiency, Symbiodiniaceae density, chlorophyll concentration, respiratory rates, primary production, and calcification across the various treatments.

Results

Persistent hypoxia was observed at the study site. Subsequent experiments revealed that low oxygen levels led to a notable decrease in the maximum quantum yield over time in all the species tested, accompanied by declining rates of respiration and calcification. Our findings reveal the sensitivity of corals to both hypoxia and anoxia, particularly affecting processes crucial to energy balance and structural integrity. Notably, P. lutea and T. mesenterina exhibited no mortality over the 72-hour period under hypoxia and anoxia conditions, while P. acuta, exposed to anoxia, experienced mortality with tissue loss within 24 hours. This study underscores species-specific variations in susceptibility associated with different morphologies under low oxygen conditions. The results demonstrate the substantial impact of deoxygenation on coral growth and health, with the compounded challenges of climate change and coastal pollution exacerbating oxygen availability, leading to increasingly significant implications for coral ecosystems.
Percepção ambiental dos alunos do ensino médio da Escola Estadual Nossa Senhora da Conceição, município de Belém de Brejo do Cruz/PB
Authors: Simplicio Sérgio Ricardo da Costa , Silva Gilmar Gomes da , Fernandes Leonardo Gomes , Fonseca Neto Pedro Rodrigues da , Brasil Antônio Edielson Pereira , Oliveira Neto Glicério de
Published: September 2024

Objetivou-se neste trabalho a avaliação da percepção ambiental dos alunos da Escola Estadual do Ensino fundamental e Médio Nossa Senhora da Conceição.  Participaram da pesquisa 100 alunos de 5 turmas do ensino médio. Os dados foram obtidos por meio da aplicação de um questionário constituído por 7 perguntas. Cada aluno respondeu ao questionário individualmente. Depois de respondidas as questões, foram elaboradas um gráfico para cada turma e observou-se no 1° ano “C” a maioria dos alunos não conseguiram responder as questões 1,3,6 e 7. Para o 1° ano “A” a minoria dos alunos obtiveram resultados satisfatórios nas questões 2 e 4 enquanto que a maioria ficou restrita nas questões 1,3,5,6 e 7. Os participantes do 3° ano “A” obtiveram resultados satisfatórios nas questões 1,2,3,4, e 5. O 3° ano “B” obteve maior número de acertos em relação às turmas anteriores nas questões 1,2,3,4,5,6 e 7 do questionário aplicado, ou seja, esses alunos tiveram excelentes resultados na definição de educação ambiental, problemas ambientas, bem como a definição de reciclagem e a coleta seletiva com reciclagem como forma ecológica do destino do lixo.
Variation of Adipokines in Obese versus Non Obese Patients with Polycystic Ovary Syndrome and its Association to Visceral Adiposity Index: A Cross-sectional Study
Authors: Maitra Chaitali , Raj Rishika , Maitra Arjun , Gupta Ramesh Chandra
Published: September 2024

Introduction: Obesity is a prevalent co-morbidity in Polycystic Ovarian Syndrome (PCOS), causing metabolic disturbances that lead to changes in endocrinological homeostasis. Adipokines are proinflammatory molecules secreted by adipose tissues that affect metabolic and endocrinological mechanisms. Excess androgen secretion alters fat distribution and deposition, leading to increased visceral obesity in PCOS, which is a major concern for the development of cardiometabolic events. Aim: To assess the Visceral Adiposity Index (VAI) and levels of different adipokines in non obese and obese PCOS patients, and to establish the relationship between VAI and circulating adipokines in both non obese and obese phenotypes of PCOS patients. Materials and Methods: This cross-sectional study was conducted at the Mayo Institute of Medical Sciences, Barabanki, Uttar Pradesh, India from November 2019 to August 2021. A total of 144 patients diagnosed with PCOS according to the Rotterdam criteria were divided into non obese and obese categories based on Body Mass Index (BMI). VAI was calculated using a sex-specific formula, and serum levels of adiponectin, resistin, and leptin were measured by Enzyme Linked Immuno Sorbent Assay (ELISA). Fasting glucose, insulin, and serum lipid profiles were evaluated. Data were statistically analysed using Student’s t-tests and Pearson’s correlation coefficient. Weighted linear regression was used to detect any relationships between adipokines, obesity indicators, and VAI. Results: A total of 144 female patients with a mean age of 27.47±0.33 years suffering from PCOS were included in this study. VAI was significantly higher (p-value=0.034) in non obese patients than in obese patients. There was a significant correlation between VAI and resistin (r-value=0.302, p-value=0.011) and leptin (r-value=0.308, p-value=0.009) in the non obese PCOS group. Additionally, there was a significant association between obesity indicators {BMI, Body Fat Percentage (BFP), Waist Circumference (WC), and Hip Circumference (HC)} and VAI; this association was absent in the obese subgroup. According to the regression model, leptin was the only statistically relevant predictor for VAI among the studied PCOS patients (t-value=2.278, p-value=0.024). Conclusion: VAI was higher in non obese PCOS patients. An imbalance in adipokines (leptin and resistin) may lead to the accumulation of visceral fat without significantly affecting BMI.
Association of Anaemia with Metastasis Section in Non Haematological Malignancies: A Cross-sectional Study
Authors: Vaishnav Bhumika , Thakkar Nirali , Wadivkar Aniruddh N , Mondkar Saish , . Kshitij
Published: September 2024

Introduction: Anaemia and cancer are two non communicable diseases with high global prevalence. The presence of anaemia in cancer patients is common, and its aetiology is multifactorial. Aim: To analyse the clinical profile, type and severity of anaemia in non haematological malignancies and to determine how the presence of metastasis affects it. Materials and Methods: A cross-sectional study was conducted in the Department of General Medicine, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pune, Maharashtra, India, between January 2022 and December 2023. Out of 1,294 patients diagnosed with malignancy, 190 subjects were analysed. The study included patients over 18 years of age diagnosed with non haematological malignancies who had anaemia according to the World Health Organisation (WHO) definition {females with Haemoglobin (Hb) <12 g/ dL; males with Hb <13 g/dL}. The subjects were divided into two groups: patients with and without metastatic disease. All patients underwent complete haemogram, iron studies, serum vitamin B12 levels and serum folate levels. Anaemia was classified into types: normocytic anaemia, microcytic anaemia and macrocytic anaemia. The student’s t-test, Chi-square test and Fisher’s exact test were used to analyse and interpret the collected data. Results: Of the 190 selected subjects, 80 (42.1%) (group A) had metastatic disease, while 110 (57.9%) (group B) had no evidence of metastasis. The mean±Standard Deviation (SD) age of patients in group A was 55.43±11.12 years and in group B was 54.38±9.8 years. There were 90 males and 100 females in the study. The most common cause of anaemia was found to be chemotherapy-induced anaemia. The most common type of anaemia among all study subjects was normocytic anaemia (52.1%). The prevalence of severe anaemia was significantly higher in patients with metastatic cancers compared to those without metastatic cancers (p-value=0.0003). Conclusion: Chemotherapy-induced and normocytic anaemia were the most common types of anaemia in non haematological malignancies. Severe anaemia was more prevalent in patients with metastatic cancers. Anaemia in cancer patients should be monitored and managed optimally to improve outcomes.
How to preserve society and the biosphere in the technogenic world
Authors: Dergacheva E. A.
Published: September 2024

At the beginning of the last century, V.I. Vernadsky believed that associated humanity would act rationally in accordance with the collective mind, a powerful science, changing the biosphere in a direction favorable to society. At the turn of the XX–XXI centuries, technocratic social theories justify the transition of mankind to post-industrial development with a high level and quality of life on the planet. But the modern technogenic world is developing in accordance with the interests of capitalistically developed countries focused on their own well–being due to the accelerated destruction of world biological resources, the comprehensive expansion of the artificial environment of life – the urban technosphere, which results in the destruction of soil cover as the basis of biospheric life, deterioration of human population health and shortening of his life expectancy. Over the past two decades, the interrelated integration of the processes of social, artificial and biological development has been studied by scientists of the Interdisciplinary Scientific and Philosophical School of Socio-Technogenic Development of the World and come to the conclusion that the technosphere shell of life is rapidly taking the place of the age-old soil shell of the biosphere development on land. People should not allow the death of the biosphere on land, which leads us to the need to approve a safe socio-biosphere strategy for the development of life instead of a socially man-made way of its destruction.
Victorian dinosaurs in St. Petersburg
Authors: Sennikov A. G.
Published: September 2024

The first sculptural reconstructions of fossil animals were created in the mid-19th century by the sculptor, artist and naturalist B. W. Hawkins. These reconstructions were widely used at that time for educational and academic purposes, including in Russia, in St. Petersburg.
О ЧЕМ ЗВУЧАТ МЕТЕОРЫ
Authors: Morozova Tatiana
Published: September 2024

Метеоры – это явления, которые своей загадочностью всегда привлекали человека. Метеорное вещество постоянно поступает в атмосферу Земли. В день на Землю выпадает около 100 тонн космической пыли (а на ранней Земле это число было в разы больше). Сравнительно небольшие метеорные тела сгорают на высотах 80–120 км, более крупные могут проникать в глубокие слои атмосферы и достигать поверхности Земли.
ВУЛКАНЫ ИО ПРОДОЛЖАЮТ НЕПРЕРЫВНО ИЗВЕРГАТЬСЯ УЖЕ 4.5 МИЛЛИАРДА ЛЕТ
Authors: Govorova A.F.
Published: September 2024

Группа ученых из Калифорнийского технологического института, Центра космических полетов имени Годдарда и Калифорнийского университета в Санта-Барбаре (США) пришли к выводу, что вулканы на спутнике Юпитера Ио продолжают непрерывно извергаться вот уже на протяжении 4.57 миллиарда лет – т.е. с момента образования спутника планеты-гиганта.
Nicolaus De Sanctis, Clement IV and the Roman Curia in Search of Identity
Authors: Voskoboynikov Oleg
Published: September 2024

This article deals with a less known Latin treatise, called Moral Rhetoric on the Functions of the Members of the Human Body. It is by the Capuan rhetorician Nicolaus de Sanctis, chaplain to several popes, and is dedicated to pope Clement IV (1265–1268). This unusual work has shown that it is perhaps a kind of mirror of Christian society as the Roman Curia wanted it to be, through the difficult times during the wars over the Sicilian succession, in which the Papacy was deeply involved. It is also an important link in the history of medieval organological literature and the rhetorical tradition associated with ars dictaminis cultivated in Southern Italy.
Risk Management and Performance of Deposit Money Banks in Nigeria
Authors: Odigie Innocent William Otaigboria , Adim Chidiebere Victor
Published: September 2024

This study examined the relationship between risk management and performance of deposit money banks in Nigeria as moderated by environmental turbulence. The study adopted the cross-sectional research survey design. Primary data was generated through structured questionnaire while the population of study was the 24 deposit money banks in Nigeria. The entire population of 24 deposit money banks were adopted as a census. However, the number of respondents/ participants in the study was one hundred and twenty senior level managers of the 24 Deposit Money Banks in Nigeria. The reliability of the instrument was achieved by the use of the Cronbach Alpha coefficient with all the items scoring above 0.70. The hypotheses were tested using the Spearman’s Rank Order Correlation Coefficient. The tests were carried out at a 0.05 significance level. Findings revealed that there is a significant relationship between risk management and performance of deposit money banks in Nigeria. Therefore, the study concludes that the adoption of risk management practice positively enhances the performance of deposit money banks in Nigeria. This implies that by adopting a proactive approach to risk management, deposit money banks can identify, assess, and mitigate potential risks that could adversely impact their operations. Hence, the study recommends that deposit money banks should conduct regular and thorough risk assessments to identify potential risks that could impact the bank's operations and performance. This includes assessing credit, market, liquidity, operational, and other relevant risks. Understanding the risk landscape is crucial for developing effective risk management strategies.
Modeling and Forecasting High Frequency Currency Exchange Rates. A Comparative Study of ARIMA, ANN, and Hybrid ARIMA-ANN Models
Authors: Ondieki Roseline , Waititu Hellen , Nyabwanga Robert Nyamao
Published: September 2024

Aims/ Objectives: The study develops comparative results on the modeling and prediction performance of the autoregressive integrated moving average (ARIMA), artificial neural network (ANN) and the hybrid ARIMA-ANN time series models for high frequency data.
Methodology: The study made use of ARIMA, ANN, and hybrid ARIMA-ANN models to forecasts the East Africa Community countries' daily currency exchange rates data which were obtained from the Central Bank of Kenya website and covered the period from January 2017 to December 2023. Stationarity of the time series data was established using the ADF test. The Ljung Box test and ACF plots were used to establish and compare the goodness-of-fit of the resultant models while the Mean Absolute Percentage Error (MAPE) and Root Mean Squared Error(RMSE) values were used to compare the prediction performance.
Results: The study established that the hybrid ARIMA-ANN methodolgy provided better-fitting models for the currency exchange rates data compared to ARIMA and ANN modeling strategies since all the Lyung Box test statistics had p values greater than 5%. Comparatively, the hybrid methodology registered lower MAPE and RMSE values hence had better prediction accuracy compared to ARIMA and ANN methods.
Conclusion: The Hybid methodology improves the modeling and forecasting accuracy over the ARIMA and ANN models for high frequency time series data due to its ability to captures both the linear and nonlinear patterns in the time series data.
Evaluation of Seed Quality of Grain Corn Varieties through Accelerated Ageing
Authors: Rahman Faizah Salvana Abd , Ghani Muhammad Najib Othman , Hashim Halimah , Mustaffer Nurhazwani , Maznan Ahmad Firdaus
Published: September 2024

In an accelerated ageing test carried out to evaluate seed quality two hybrid grain corn varieties, 4546 and 888, were subjected to ageing conditions to assess their tolerance. The objective was to identify any differences between the varieties in their ability to maintain seed quality under accelerated ageing conditions. These tests simulate and hasten the natural ageing process of seeds, providing insight into their performance during storage over time and under adverse conditions. Following the ageing process, factors such as germination rate, vigour, and overall seed quality were assessed. The seeds of hybrid grain corn varieties 4546 and 888 were exposed to accelerated ageing by maintaining them at 40°C and 100% relative humidity in a growth chamber. Evaluations were conducted at intervals of 0, 48, 96, and 144 hours. The overall results indicated that seed quality in grain corn deteriorates following accelerated ageing treatment. Variety 4546 showed a rapid decrease in germination, germination rate, and seedling vigour throughout the testing period. Both varieties experienced an increase in moisture content from 11% to 20% during the ageing process. Additionally, the electrical conductivity of seed leachate increased for both varieties as the testing progressed. The experiment concluded that the 888 grain corn variety outperformed 4546 in all evaluated parameters. The 4546 variety was found to be highly sensitive to accelerated ageing.
Revolutionizing Food Safety and Crop Production: Harnessing Novel Biosensors
Authors: Gafoor Rabeen Abdul , S.R. Sharu , P. Shalini Pillai , Thomas Usha C. , G. Gayathri , Gopinath Pratheesh P.
Published: September 2024

Farmers and food manufacturers are under immense pressure from consumers and food safety regulations to deliver pollutant-free, high-quality foods. The extensive use of chemicals in food production poses ecological as well as health risks. In order to meet the demand for safe, preservative-free foods, rapid sensing techniques are required. Traditional analysis methods are time consuming, laboratory bound, expensive and require highly skilled personnel. Alternative analysis systems such as biosensors, which are user-friendly and enable real-time monitoring in the field should also be used. Biosensors have been developed to detect foodborne pathogens such as Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, etc. that cause food contamination, and a large number of cases are reported annually. Mycotoxin-contaminated food presents a serious threat to food safety. Biosensors have been utilised to identify Penicillium and aflatoxin infections, which are major mycotoxins found in food. Additionally, biosensors for identifying artificially ripened fruits have also been developed. Biosensors have been developed to detect pesticide residues such as atrazine, glyphosate, 2,4-D, methyl parathion, lindane, etc. Early identification of plant pathogens, including bacteria, viruses, and fungi, is crucial because it enables farmers to take the necessary precautions to control the disease. Pathogens such as Fusarium sp., Phytophthora palmivora, tomato leaf curl virus are among some of the pathogens that have been successfully detected using novel biosensors. They can also be used for detecting heavy metals as they are cheaper, faster, more reliable and selective than traditional analysis methods. A bacterial biosensor was developed using Bacillus megaterium, which was sensitive to heavy metals like cadmium, copper and zinc in soil. Additionally, biosensors have been developed to detect heavy metal pollution in plants as well as irrigation water.
Evaluation of different Varieties of Gladiolus (Gladiolus grandifloras L.) Cultivars under Agro-climatic Conditions of Prayagraj, India
Authors: Samyuktha Udu Rani , Singh Devi , Fatmi Urfi
Published: September 2024

An experiment was conducted during rabi season 2023 at Horticulture Research Farm, Department of Horticulture, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (Uttar Pradesh). The experiment has 20 different varieties laid out in Randomized Block Design (RBD) in three replications. The results showed that the all the cultivars had significant differences for vegetative, floral, corm characters when evaluated under Agro climatic conditions of Prayagraj. Twenty cultivars namely Pusa Sindhuri, Pusa Suhagin, Red Ginger, Red Majesty, Sancerre, Shahanoda, Shobha, Smoky Lady, Snow Princess, Solan shrinagar, Souvik Biscuits, Suyrakiran, Swarnima, Sweta, Tambri, Urmi, VickyLin, WeddingCreamby, White Prosperity, Yellow Stone were evaluated for their performance. Based on their performance, it is concluded that all the cultivars can be grown under Prayagraj Agro climatic conditions, but cultivar yellow stone, white  property, wedding creamby, Vickylin has found to be promising in respect of all parameters under Agro climatic conditions of Prayagraj.
The Clinical and Histopathological Characteristics of Breast Lesions in Western Sudan
Authors: Adam Tumadir Mohammed , Agabeldour Ahmed Abdulla , Dafea Hasabsidu Adam , Ahmed Esraa Daffalla Mohamed , Ahmed Mirghani Kamal Eldin Mirghani , Monwer Tasneem Alfaki Mohamedelnour , Babker Maysa Khowgali AbdAlla , Mohammed Amal Khalil Yousif , Humida Eldisugi Hassan Mohammed , Bahar Mustafa Elnour Hussein , Elnour Hikmat Siddig Elzain , Monawer Tomadir Elfaki Mohamedelnour , Saror Gesmelseid Abdelader Gesmelseid , Salem Najla Adam Elsharif , Hashim Khalid Nasralla Habeeballa , Ahmed Hussain Gadelkarim
Published: September 2024

Background: Presenting advanced breast cancer in Sudan is a significant challenge. Consequently, the objective of this investigation was to evaluate the breast lesion pattern in Western Sudan.
Methodology: This study was a retrospective descriptive analysis carried out in two major entities that offer histopathology services in the northern region of Kordofan State. The study encompassed a total of 190 patients, with 110 of them having malignant lesions and 79 having benign breast lesions.
Results: Among the 110 cases of breast cancer, 59% were classified as invasive ductal carcinoma (DC), 12.7% as infiltrating DC, and 9% as invasive lobular carcinoma (LC). We identified 37.9% of the 79 non-cancerous growths as fibroadenoma, 25.3% as fibrocystic changes, and 6.3% as Phyllodes tumors.
Conclusion: In Sudan, the advanced presentation of breast cancer is common. When a patient presents with a lump, the likelihood of a malignant diagnosis is higher. Breast cancer is a significant concern for younger Sudanese women, particularly those under the age of 45 years.
The Mechanization Trend and Economic Prospects of Micro Irrigation in India
Authors: Yadav Narendra , Kharkwal Sheela , Meena MK , Mhaskey Akash , Lamba Hemant Kumar
Published: September 2024

Agriculture plays a crucial role in the Indian economy, contributing nearly 16 percent to the total GDP, with farm mechanization serving as the backbone of agricultural GDP. This study analyzes the growth trend in agricultural mechanization in India by examining the shift from traditional human and animal-powered equipment to mechanically powered farm equipment like tractors and power tillers, which are vital for farm mechanization. Secondary data from 2004-2005 to 2021-2022 were used, and the compound annual growth rate (CAGR) and correlation analyses were performed to assess trends. The study found a 6.78 percent annual growth in tractor purchases, with a linear trend equation showing a 0.93 coefficient of determination (R²) at a 1 percent significance level, and a Pearson correlation coefficient of 0.76, indicating a strong correlation between tractor and power tiller purchasing trends. Precision farming, a type of farm management that uses information technology to optimize crop and soil health and productivity while minimizing production costs, is increasingly adopted due to advancements in mechanization. In India, precision farming techniques like drip and sprinkler micro-irrigation, covering 13,476,804 hectares with 46.90 percent under drip and 53.09 percent under sprinkler, have proven beneficial, especially in water-scarce areas. Precision farming is practiced mainly by medium to large progressive farmers, often experimentally or commercially, and offers profitable returns when applied to high-value crops such as fruits, vegetables, flowers, and medicinal plants.
Transforming Communication in the Wake of COVID-19: Overcoming Challenges and Shaping the Future
Authors: Berdimuratov Aydogdy , Rahmonov Shirinbek
Published: September 2024

Aims: This study aims to investigate how the COVID-19 pandemic has transformed communication practices, focusing on the challenges encountered, adaptive strategies employed, and future directions in communication.
Study Design: This research employs a qualitative study design utilizing in-depth interviews to capture the experiences and perspectives of individuals and organizations.
Place and Duration of Study: The study was conducted remotely, with interviews taking place from February 2024 to April 2024.
Methodology: The research involved in-depth interviews with participants across various sectors to explore the impact of the pandemic on communication. Participants discussed technological barriers, emotional and psychological challenges, and their adaptive strategies. The interviews were analyzed thematically to identify key patterns and trends.
Results: The study reveals that technological barriers, such as connectivity issues and difficulties with digital platforms, significantly affected communication quality. Participants reported increased anxiety and communication fatigue as major emotional and psychological challenges. Despite these issues, there was a notable shift towards digital tools, the establishment of new communication norms, and changes in work and social practices. The findings indicate a continued reliance on digital technologies, the rise of hybrid communication models, and an increased focus on digital literacy and emotional well-being.
Conclusion: The study highlights the need for ongoing adaptation in communication practices and further research to address the evolving landscape of communication in a post-pandemic world. The findings underscore the importance of improving digital infrastructure, supporting emotional well-being, and fostering digital literacy.
Effects of dispersion in tsunami Green's functions and implications for joint inversion with seismic and geodetic data: A case study of the 2010 Mentawai Mw 7.8 earthquake
Authors: Li Linyan , Cheung Kwok Fai , Yue Han , Lay Thorne , Bai Yefei
Published: October 2016

Tsunami observations play an important role in resolving offshore earthquake slip distributions. Nondispersive shallow‐water models are often used with a static initial sea surface pulse derived from seafloor deformation in computation of tsunami Green's functions. We compare this conventional approach with more advanced techniques based on a dispersive model with a static initial sea surface pulse and with the surface waves generated from kinematic seafloor deformation. These three sets of tsunami Green's functions are implemented in finite‐fault inversions with and without seismic and geodetic data for the 2010 Mentawai Mw 7.8 tsunami earthquake. Seafloor excitation and wave dispersion produce more spread‐out waveforms in the Green's functions leading to larger slip with more compact distribution through the inversions. The fit to the recorded tsunami and the deduced seismic moment, which reflects the displaced water volume, are relatively insensitive to the approach used for computing Green's functions.
The onset of sediment transport in vegetated channels predicted by turbulent kinetic energy
Authors: Yang J. Q. , Chung H. , Nepf H. M.
Published: October 2016

This laboratory study advances our understanding of sediment transport in vegetated regions, by describing the impact of stem density on the critical velocity, Ucrit, at which sediment motion is initiated. Sparse emergent vegetation was modeled with rigid cylinders arranged in staggered arrays of different stem densities. The sediment transport rate, Qs, was measured over a range of current speeds using digital imaging, and the critical velocity was selected as the condition at which the magnitude of Qs crossed the noise threshold. For both grain sizes considered here (0.6–0.85 mm and 1.7–2 mm), Ucrit decreased with increasing stem density. This dependence can be explained by a threshold condition based on turbulent kinetic energy, kt, suggesting that near‐bed turbulence intensity may be a more important control than bed shear stress on the initiation of sediment motion. The turbulent kinetic energy model unified the bare bed and vegetated channel measurements.
Estimate of Rayleigh‐to‐Love wave ratio in the secondary microseism by a small array at Piñon Flat observatory, California
Authors: Tanimoto Toshiro , Lin Chin‐Jen , Hadziioannou Céline , Igel Heiner , Vernon Frank
Published: October 2016

Using closely located seismographs at Piñon Flat (PFO), California, for 1 year long record (2015), we estimated the Rayleigh‐to‐Love wave energy ratio in the secondary microseism (0.1–0.35 Hz) in four seasons. Rayleigh wave energy was estimated from a vertical component seismograph. Love wave energy was estimated from rotation seismograms that were derived from a small array at PFO. Derived ratios are 2–2.5, meaning that there is 2–2.5 times more Rayleigh wave energy than Love wave energy at PFO. In our previous study at Wettzell, Germany, this ratio was 0.9–1.0, indicating comparable energy between Rayleigh waves and Love waves. This difference suggests that the Rayleigh‐to‐Love wave ratios in the secondary microseism may differ greatly from region to region. It also implies that an assumption of the diffuse wavefield is not likely to be valid for this low frequency range as the equipartition of energy should make this ratio much closer.
Quantifying cloud base updraft speeds of marine stratocumulus from cloud top radiative cooling
Authors: Zheng Youtong , Rosenfeld Daniel , Li Zhanqing
Published: October 2016

Marine stratocumulus clouds play a significant role in the Earth's radiation budget. The updrafts at cloud base (Wb) govern the supersaturation and therefore the activation of cloud condensation nuclei, which modifies the cloud and precipitation properties. A statistically significant relationship between Wb and cloud top radiative cooling rate (CTRC) is found from the measurements of the Department of Energy's Atmospheric Radiation Measurement Mobile Facility on board a ship sailing between Honolulu and Los Angeles. A similar relation was found on Graciosa Island but with greater scatter and weaker correlation presumably due to the island effect. Based on the relation, we are able to estimate the cloud base updrafts using a simple formula: Wb = −0.44 × CTRC + 22.30 ± 13, where the Wb and CTRC have units of cm/s and W/m2, respectively. This quantification can be utilized in satellite remote sensing and parameterizations of Wb in general circulation models.
Urbanization causes nonstationarity in Indian Summer Monsoon Rainfall extremes
Authors: Singh Jitendra , Vittal H. , Karmakar Subhankar , Ghosh Subimal , Niyogi Dev
Published: October 2016

Global and local environmental changes are likely to introduce nonstationarity in the characteristics of Indian Summer Monsoon Rainfall (ISMR) extremes. Here we perform a nonstationary frequency analysis on ISMR extremes in a Generalized Additive Model for Location, Scale and Shape framework with a cluster of 74 models, considering nonstationarity in different possible combinations. Interestingly, we observe significant nonstationarity in ISMR extremes in urbanizing/developing‐urban areas (transitioning from rural to urban), compared to completely urbanized or rural areas. This presents a postulation that the extent of urbanization plays a significant role in introducing nonstationarity in ISMR extremes. We emphasize the effect of urbanization in changing the character of ISMR extremes, which further needs a scientific re‐evaluation by implementing physics‐based modeling. The impact of these observational studies will be critical in correcting the bias of model projections of ISMR.
Exclusion principle for very oblique and parallel lower band chorus waves
Authors: Agapitov O. V. , Mourenas D. , Artemyev A. V. , Mozer F. S.
Published: October 2016

Simultaneous measurements of intense very oblique and parallel lower band chorus waves are rare in the Earth's inner magnetosphere. A possible explanation is that very oblique and parallel waves generally cannot be generated simultaneously, due to a suppression of parallel wave growth by fast nonlinear modifications of the electron distribution induced by very oblique waves. The corresponding exclusion principle for intense lower band chorus waves is proposed based on in situ measurements and tested in particle simulations. Parallel acceleration of low‐energy electrons trapped by very oblique waves up to the energy range of cyclotron resonance with parallel waves is very efficient and should usually result in a quick suppression of the temperature anisotropy necessary for parallel wave growth. Selected spacecraft observations have confirmed the main aspects of the proposed exclusion scenario. These results should help to better assess the respective roles of oblique and parallel lower band chorus in energetic electron dynamics.
Sources and pathways of the upscale effects on the Southern Hemisphere jet in MPAS‐CAM4 variable‐resolution simulations
Authors: Sakaguchi Koichi , Lu Jian , Leung L. Ruby , Zhao Chun , Li Yanjie , Hagos Samson
Published: October 2016

Impacts of regional grid refinement on large‐scale circulations (“upscale effects”) were detected in a previous study that used the Model for Prediction Across Scales‐Atmosphere coupled to the physics parameterizations of the Community Atmosphere Model version 4. The strongest upscale effect was identified in the Southern Hemisphere jet during austral winter. This study examines the detailed underlying processes by comparing two simulations at quasi‐uniform resolutions of 30 and 120 km to three variable‐resolution simulations in which the horizontal grids are regionally refined to 30 km in North America, South America, or Asia from 120 km elsewhere. In all the variable‐resolution simulations, precipitation increases in convective areas inside the high‐resolution domains, as in the reference quasi‐uniform high‐resolution simulation. With grid refinement encompassing the tropical Americas, the increased condensational heating expands the local divergent circulations (Hadley cell) meridionally such that their descending branch is shifted poleward, which also pushes the baroclinically unstable regions, momentum flux convergence, and the eddy‐driven jet poleward. This teleconnection pathway is not found in the reference high‐resolution simulation due to a strong resolution sensitivity of cloud radiative forcing that dominates the aforementioned teleconnection signals. The regional refinement over Asia enhances Rossby wave sources and strengthens the upper level southerly flow, both facilitating the cross‐equatorial propagation of stationary waves. Evidence indicates that this teleconnection pathway is also found in the reference high‐resolution simulation. The result underlines the intricate diagnoses needed to understand the upscale effects in global variable‐resolution simulations, with implications for science investigations using the computationally efficient modeling framework.
Predicting the magnetic vectors within coronal mass ejections arriving at Earth: 2. Geomagnetic response
Authors: Savani N. P. , Vourlidas A. , Richardson I. G. , Szabo A. , Thompson B. J. , Pulkkinen A. , Mays M. L. , Nieves‐Chinchilla T. , Bothmer V.
Published: October 2016

This is a companion to Savani et al. (2015) that discussed how a first‐order prediction of the internal magnetic field of a coronal mass ejection (CME) may be made from observations of its initial state at the Sun for space weather forecasting purposes (Bothmer‐Schwenn scheme (BSS) model). For eight CME events, we investigate how uncertainties in their predicted magnetic structure influence predictions of the geomagnetic activity. We use an empirical relationship between the solar wind plasma drivers and Kp index together with the inferred magnetic vectors, to make a prediction of the time variation of Kp (Kp(BSS)). We find a 2σ uncertainty range on the magnetic field magnitude (|B|) provides a practical and convenient solution for predicting the uncertainty in geomagnetic storm strength. We also find the estimated CME velocity is a major source of error in the predicted maximum Kp. The time variation of Kp(BSS) is important for predicting periods of enhanced and maximum geomagnetic activity, driven by southerly directed magnetic fields, and periods of lower activity driven by northerly directed magnetic field. We compare the skill score of our model to a number of other forecasting models, including the NOAA/Space Weather Prediction Center (SWPC) and Community Coordinated Modeling Center (CCMC)/SWRC estimates. The BSS model was the most unbiased prediction model, while the other models predominately tended to significantly overforecast. The True skill score of the BSS prediction model (TSS = 0.43 ± 0.06) exceeds the results of two baseline models and the NOAA/SWPC forecast. The BSS model prediction performed equally with CCMC/SWRC predictions while demonstrating a lower uncertainty.
Kinetics of gravity‐driven slug flow in partially wettable capillaries of varying cross section
Authors: Nissan Alon , Wang Qiuling , Wallach Rony
Published: October 2016

A mathematical model for slug (finite liquid volume) motion in not‐fully‐wettable capillary tubes with sinusoidally varying cross‐sectional areas was developed. The model, based on the Navier‐Stokes equation, accounts for the full viscous terms due to nonuniform geometry, the inertial term, the slug's front and rear meniscus hysteresis effect, and dependence of contact angle on flow velocity (dynamic contact angle). The model includes a velocity‐dependent film that is left behind the advancing slug, reducing its mass. The model was successfully verified experimentally by recording slug movement in uniform and sinusoidal capillary tubes with a gray‐scale high‐speed camera. Simulation showed that tube nonuniformity has a substantial effect on slug flow pattern: in a uniform tube it is monotonic and depends mainly on the slug's momentary mass/length; an undulating tube radius results in nonmonotonic flow characteristics. The static nonzero contact angle varies locally in nonuniform tubes owing to the additional effect of wall slope. Moreover, the nonuniform cross‐sectional area induces slug acceleration, deceleration, blockage, and metastable‐equilibrium locations. Increasing contact angle further amplifies the geometry effect on slug propagation. The developed model provides a modified means of emulating slug flow in differently wettable porous media for intermittent inlet water supply (e.g., raindrops on the soil surface).
Locally conservative groundwater flow in the continuous Galerkin method using 3‐D prismatic patches
Authors: Wu Qiang , Zhao Yingwang , Lin Yu‐Feng F. , Xu Hua
Published: October 2016

A new procedure has been developed to improve the velocity field computed by the continuous Galerkin finite element method (CG). It enables extending the postprocessing algorithm proposed by Cordes and Kinzelbach (1992) to three‐dimensional (3‐D) models by using prismatic patches for saturated groundwater flow. This approach leverages a dual mesh to preserve local mass conservation and provides interpolated velocities based on consistent fluxes. To develop this 3‐D approach, a triangular conservative patch is introduced by computing not only advection fluxes, but also vertical infiltrations, storage changes, and other sink or source terms. This triangular patch is then used to develop a prismatic patch, which consists of subprisms in two layers. By dividing a single two‐layer patch into two separate one‐layer patches, two dimensional (2‐D) algorithms can be applied to compute velocities. As a consequence, each subelement is able to preserve local mass conservation. A hypothetical 3‐D model is used to evaluate the precision of streamlines and flow rates generated by this approach and the FEFLOW simulation program.
Evolution of wet‐day and dry‐day frequency in the western Amazon basin: Relationship with atmospheric circulation and impacts on vegetation
Authors: Espinoza Jhan Carlo , Segura Hans , Ronchail Josyane , Drapeau Guillaume , Gutierrez‐Cori Omar
Published: October 2016

This paper documents the spatiotemporal evolution of wet‐day and dry‐day frequency (WDF and DDF) in the western Amazon, its relationships with oceanic and atmospheric variability and possible impact on vegetation. WDF and DDF changed significantly during the 1980–2009 period (p < 0.05). An increase in WDF is observed after 1995 over the northern part of the western Amazon (Marañón basin). The average annual value of WDF changed from 22 days/yr before 1995 to 34 days after that date (+55% after 1995). In contrast, DDF increased significantly over the central and southern part of this region (Ucayali basin) after 1986. Average annual DDF was 16.2 days before 1986 and 23.8 days afterward (+47% after 1986). Interannual variability in WDF appears to be modulated by changes in Pacific SST and the Walker cell during the November–March season. This mechanism enhances convective activity over the northern part of the western Amazon. The increase in DDF is related to warming of the North Tropical Atlantic SST, which produces changes in the Hadley cell and subsidence over the central and the southern western Amazon. More intense seasonal hydrological extremes in the western Amazon therefore appear to be related to changes in WDF and DDF that occurred in 1995 and 1986, respectively. During the 2001–2009 period, an index of vegetation condition (NDVI) appears negatively correlated with DDF (r = −0.95; p < 0.0001). This suggests that vegetation in the western Amazon is mainly water limited, rather than light limited and indicates that the vegetation is highly sensitive to concentration of rainfall.
The influence of an in‐network lake on the timing, form, and magnitude of downstream dissolved organic carbon and nutrient flux
Authors: Kalinin Alexey , Covino Tim , McGlynn Brian
Published: October 2016

Within fluvial networks, lakes can be sinks or sources of dissolved organic carbon (DOC) and nutrients, yet the controls over sink‐source behavior remain unclear. We investigated the influence that an in‐network lake exerted on DOC and nutrient export. Our investigation consisted of: (1) injecting a conservative tracer to determine lake travel times and flow paths; (2) sampling lake inflow, outflow, and surrounding groundwater to determine water and nutrient budgets; and, (3) sampling internal lake profiles to ascertain in‐lake physico‐chemical patterns through time. Conservative tracer data indicated considerable in‐lake retention and combined with inflow‐outflow discharge measurements revealed a decoupling of kinematic and solute pulses. Nitrate (NO3) was the dominant form of dissolved inorganic nitrogen (DIN) at lake inflow whereas ammonium (NH4) became the dominant component at lake outflow. The lake was a sink for NO3‐N and PO4, but a source for NH4‐N, DON, TDN, and DOC. We observed hydrologic controls on DOC concentrations and export patterns, but redox controls on DIN dynamics. Our results indicate that lakes within fluvial networks can be sources of dissolved organic material and reduced nitrogen (NH4) while simultaneously being sinks for NO3‐N and PO4‐P. Determining controls on sink‐source behavior and the cumulative effect of lakes on DOC and nutrient budgets is a necessary first step toward improved understanding of the role of lakes in network‐ to regional‐scale dynamics.
Rescaling the complementary relationship for land surface evaporation
Authors: Crago R. , Szilagyi J. , Qualls R. , Huntington J.
Published: October 2016

Recent research into the complementary relationship (CR) between actual and apparent potential evaporation has resulted in numerous alternative forms for the CR. Inspired by Brutsaert (2015), who derived a general CR in the form y = function (x), where x is the ratio of potential evaporation to apparent potential evaporation and y is the ratio of actual to apparent potential evaporation, an equation is proposed to calculate the value of x at which y goes to zero, denoted xmin. The value of xmin varies even at an individual observation site, but can be calculated using only the data required for the Penman (1948) equation as expressed here, so no calibration of xmin is required. It is shown that the scatter in x‐y plots using experimental data is reduced when x is replaced by X = (x − xmin)/(1 − xmin). This rescaling results in data falling along the line y = X, which is proposed as a new version of the CR. While a reinterpretation of the fundamental boundary conditions proposed by Brutsaert (2015) is required, the physical constraints behind them are still met. An alternative formulation relating y to X is also discussed.
Experimental study on CH* chemiluminescence characteristics of impinging flames in an opposed multi‐burner gasifier
Authors: Zhang Qing , Gong Yan , Guo Qinghua , Song Xudong , Yu Guangsuo
Published: October 2016

The bandpass filtered images of impinging flames in an opposed multi‐burner (OMB) gasifier was visualized by a CCD camera combined with a high temperature endoscope. A filtering and image processing method by use of three bandpass filters was applied to subtract soot and CO2* contributions in the CH* band and obtain the CH* chemiluminescence of impinging flames. The results show that a clear reaction core is generated in the impinging zone of four‐burner impinging flames. The size of the reaction core is affected by the O/C equivalence ratio ([O/C]e) and the impingement effect is relatively stronger at lower [O/C]e. The flame lift‐off length in the gasifier is jointly controlled by the syngas concentration and the diesel atomization effect. The impingement effect shortens the flame lift‐off length. The relationship between the syngas concentration and the maximum CH* intensity makes it possible to evaluate the syngas concentration from CH* intensity. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2007–2018, 2017