bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Coefficient of Variation on the Reliability of Collapse Potential's Equation Predicted by ANNs
Authors: Najemalden Ahmed M. , Ibrahim Salah W. , Ahmed Mahmoud D.
Published: August 2020

In this paper, the Reliability Analysis with utilizing a Monte Carlo simulation (MCS) process was conducted on the equation of the collapse potential predicted by ANN to study its reliability when utilized in a situation of soil that has uncertainty in its properties. The prediction equation utilized in this study was developed previously by the authors. The probabilities of failure were then plotted against a range of uncertainties expressed in terms of coefficient of variation. As a result of reliability analysis, it was found that the collapse potential equation showed a high degree of reliability in case of uncertainty in gypseous sandy soil properties within the specified coefficient of variation (COV) for each property. When the COV ranges (0-100) for each soil properties under study, it was found also that the collapse potential equation is very well in predicting the collapse potential of gypseous sandy soils for all values of the COV lies between (0-100) % for initial water content and degree of saturation, and for values of the COV not exceed 11%, 19% for the initial dry unit weight and specific gravity respectively, as well as for the values of the COV not exceed 80%, 97% for the initial voids ratio and gypsum content respectively.
The Impact of Utilizing Silica Fume as a Filler on Asphalt Concrete Mixes
Authors: Al-Ani Aliaa Faleh
Published: August 2020

This study evaluates the influence of utilizing silica fume as a stabilizer to the filler on the behavior of asphalt mixes. The investigation of the properties of asphalt mixes was conducted by using different percentages of Silica Fume (0, 3, 6, and 9% by filler weight). Results indicate that, the OAC is 4.7% and it achieves the best results in the Marshall tests. Marshall Stability is increased by about 27.5% and the flow is decreased by about 20.2 %. In this study the implementation of 9% of silica fume in the asphalt concrete mix showed a considerable excess in the resistance to moisture damage of 28% when compared to the original mix. A great decrease in the tensile strength of asphalt concrete mixes, in a range from (4-15)% could be noticed following the moisture damage process for both the reference and silica fume adjusted mixes. Six percent of it was the optimum percent that had developed the tensile characteristics of the hot asphalt concrete mixes. The moisture sensibility of the asphalt concrete was reduced with an increase in the silica fume content. Following the moisture damage process, Silica fume of 9% was the optimum percent that had developed the punching shear characteristics of asphalt concrete. It exhibited a positive effect of 20%, while 6-9% of silica fume exhibited a positive effect of 5-9% on the development of the tensile characteristics of asphalt concrete.
Effect of Cavities from Gypsum Dissolution on Bearing Capacity of Soil under Square Footing
Authors: Hussein Israa Saleh , Snodi Lamyaa Najah
Published: August 2020

This study deals with cavities under square footing which resulted from gypsum dissolving due to water flow in gypseous soil. This process leads to collapse of soil structure and progressive compression. A model was developed for governing the mass-transport to assess the variation of gypsum content of the soil during dissolution by ground water flow then cavity formation was adopted. A general three-dimensional finite element program (PLAXIS 3D) was selected for numerical analysis method to generate the solution. The study included a number of variables and their effect on bearing capacity of gypseous soil such as (gypsum content, cavity volume and location). The cavity was represented as axis and plane cavity which has square section. The results show that the most dangerous case is found when the cavity locates at the center of footing base (Z/B = 0), where the bearing capacity decreased by (14, 37, and 69%) for (20, 30, and 40%) gypsum dissolving ratio respectively. Also, the bearing capacity decreased when the cavity volume increases due to increasing dissolution ratio. The effect of cavity became disappear after (Z/B = 4). While, when using plane cavity, there was no cavity at center of footing base (Z/B = 0) because it considered as a hole not cavity. When using plane cavity, the bearing capacity decreased by (28, 43, and 53%) for (20, 30, and 40%) dissolving ratio respectively when (Z/B=1). The effect of cavity on the bearing capacity would be disappear as the distance from footing center increase until it became disappear at (Z/B = 6 m). The plane cavity is more dangerous than axis cavity.
Performance of Raft Foundation under Static Vertical Loading in Contaminated Soil
Authors: Kareem Mahmoud S. Abdul , Kadhem Mustafa A. , AL-Nealy Halah K.T. , AL-Midhatee Lina H.A.
Published: August 2020

This study focuses on studying the impacts of residues oil on the geotechnical properties of soil and the performance of raft footing rested on oil contaminated soil and subjected to vertical loads. The contaminant used in the present study is residues oil, which is by product disposed of diesel engine oils. The soil samples are contaminated artificially by soaking with two percentage of disposed engine oil of contaminant consist of (disposed engine oil and gasoline) of 20% weight of dried of intact soil samples to obtain different concentrations of contaminant absorbed by soil samples for 30 days to complete the saturation. The mechanical model manufactured to investigate the behavior of raft footing under vertical static loading rested on intact and contaminated soils. The obtained results detected contaminant content have notable impacts on the physical soil characteristics such as the fine particles, specific gravity, plasticity index, and maximum dry unit weight decreased with the increase of contaminant content than that of intact soil. The mechanical soil properties of soil indicated the increase of the compressibility of soil with increase of residues oil percentage, but the soil strength and stiffness are decreased notably. In addition, the total and permanent settlement of raft footing constructed in contaminated soil samples increased by (27-43) % and by (41-58) % than that of an intact soil sample, respectively.
Effect of Slag on Engineering Properties of Contaminated Soil
Authors: Arbili Mohamed Moafak , Karpuzcu Mohamed , Khalil Farman
Published: August 2020

In this study investigates utilizing of slag as an additional material to improve engineering properties of contaminated soil by crude oil to changing the engineering characteristics to be satisfying and compatible, this is due to its pozzolanic reactivity. The aim of this study the impact of slag material in geotechnical engineering and to stabilize properties of contaminated soils. Two percentages of slag were utilized in this study, which is 0% and 6%. Compaction and direct shear strength tests had been conducted on the artificial contaminated prepared soil samples. In the results, showed that the increasing of slag leads to a decrease in the optimum water contents while the maximum dry density values increase. Furthermore, the shear strength is improved by utilizing slag so that slag can be considered as a stabilizing material to improve the properties of contamination soil.
Numerical Analysis of One-Dimensional Consolidation in Fine-Grained Soils
Authors: Agraine Hana , Bouali Meriem Fakhreddine , Messameh Abdelhamid
Published: August 2020

The purpose of this study is to discuss which constitutive law can describes at best the observed behavior of Silt and Gravelly Clay on the basis of experimental and analytical results. To find numerical solution for saturated soils in oedometer test Plaxis 2D the finite element software was used. In order to obtain the compressibility, excess pore pressure and degree of consolidation curves; two constitutive laws were used in this work: the Soft Soil Model ‘SSM’ and the Modified Cam Clay Model ‘MCC’. Predicted results were found in good agreement with measurements obtained from experimental test and analytical solutions. The Soft Soil is in good agreement with experimental results in the compressibility curve; however the Modified Cam Clay Model is the most appropriate if compared with the analytical solution.
Experimental and Statistical Study on Single and Groups of Stone Columns
Authors: Al-Waily Maki J. Mohammed , Fattah Mohammed Y. , Al-Qaisi Maysa Salem
Published: August 2020

In the present study, 24 laboratory models on soft clay treated with stone columns were carried out. The results for each case are analysed for the purpose of constructing a statistical model linking the variables studied. The experiments showed that the stress concentration and bearing capacity of soil treated with stone column increase with increasing the undrained shear strength (cu), number of columns and L/d ratio. The models represent a single stone column and a group of stone columns. The studied variables are three dependent variables, the stress concentration ratio (n), bearing capacity of soil treated with stone column (q) and the settlement improvement ratio (Sr) due to the existence of stone columns. The independent variables are six: the undrained shear strength of clay soil, with three values (6, 9 and 12 kPa), the number of stone columns (1, 2, 3 and 4 columns) and the length (L) to the diameter (D) of the stone column or (L/D) ratio in two values (6 and 8). Besides, the bearing capacity of the soil treated (q) with stone columns and the settlement improvement ratio were used in some statistical models as independents. After regression analysis, a set of equations that correlate the previous variables have been suggested. The incepted values for dependent variables are close to the laboratory results.
Numerical Modeling of Reinforced Concrete Slabs under Impact Loading
Authors: Mouwainea Enas Mabrook , Said Abdul Muttalib I.
Published: August 2020

This paper aims to provide a numerical model able to represent the behavior of reinforced concrete slabs subjected to impact loads. The nonlinear finite element analysis adopted by ABAQUS/Explicit Software was used in this study. A parametric study was conducted to provide a comprehensive understanding of the behavior of reinforced concrete slabs subjected to impact load. Two parameters were varied amongst the slabs which classified in to two groups. In the first groups, the thickness of slabs is variable, which was equal to (75, 100, 150 mm). In the second group, the thickness of the slab is constant and the variable was the reinforcement ratio, which ranged from (0.58 to 1%), per layer. In dynamic analysis, the load-time history and deflection-time relation were investigated. For the first group, obviously, as the slab thickness increased, the maximum central deflection of the slabs decreased by (48 – 84 %). Also, the impact force of the slabs increased by (40 – 106%) as the thickness of the slab increased by (33 – 100%). For the second group, the maximum central deflection of the slabs decreased by (6.6 – 8.8 %) as the steel reinforcement increased by (0.58 – 1 %). It was observed in the second group that the change in the value of the impact force was very limited. This lead to a fact that the impact force was not affected by the change of the reinforcement ratio, but mainly affected by the change of the slab thickness.
Tonic TCR Signaling Inversely Regulates the Basal Metabolism of CD4+ T Cells
Authors: Milam Ashley A Viehmann , Bartleson Juliet M , Buck Michael D , Chang Chih-Hao , Sergushichev Alexey , Donermeyer David L , Lam Wing Y , Pearce Erika L , Artyomov Maxim N , Allen Paul M
Published: August 2020

The contribution of self-peptide–MHC signaling in CD4+ T cells to metabolic programming has not been definitively established. In this study, we employed LLO118 and LLO56, two TCRtg CD4+ T cells that recognize the same Listeria epitope. We previously have shown that LLO56 T cells are highly self-reactive and respond poorly in a primary infection, whereas LLO118 cells, which are less self-reactive, respond well during primary infection. We performed metabolic profiling and found that naive LLO118 had a dramatically higher basal respiration rate, a higher maximal respiration rate, and a higher glycolytic rate relative to LLO56. The LLO118 cells also exhibited a greater uptake of 2-NBD–glucose, in vitro and in vivo. We extended the correlation of low self-reactivity (CD5lo) with high basal metabolism using two other CD4+ TCRtg cells with known differences in self-reactivity, AND and Marilyn. We hypothesized that the decreased metabolism resulting from a strong interaction with self was mediated through TCR signaling. We then used an inducible knock-in mouse expressing the Scn5a voltage-gated sodium channel. This channel, when expressed in peripheral T cells, enhanced basal TCR-mediated signaling, resulting in decreased respiration and glycolysis, supporting our hypothesis. Genes and metabolites analysis of LLO118 and LLO56 T cells revealed significant differences in their metabolic pathways, including the glycerol phosphate shuttle. Inhibition of this pathway reverts the metabolic state of the LLO118 cells to be more LLO56 like. Overall, these studies highlight the critical relationship between peripheral TCR–self-pMHC interaction, metabolism, and the immune response to infection.
Lipid Microbubble–Conjugated Anti-CD3 and Anti-CD28 Antibodies (Microbubble-Based Human T Cell Activator) Offer Superior Long-Term Expansion of Human Naive T Cells In Vitro
Authors: Lustig Ana , Manor Ty’Keemi , Shi Guixin , Li Jiangyuan , Wang Ying-Ting , An Yang , Liu Yu-Tsueng , Weng Nan-ping
Published: August 2020

Stimulation of human primary T cells with immobilized anti-CD3 and anti-CD28 Abs in vitro provide a system to study T cell activation and proliferation and an avenue for expanding T cells for immunotherapy. Magnetic beads conjugated with anti-CD3 and anti-CD28 Abs (Dynabeads Human T-Activator [D-TCA]) have been a golden standard for stimulating human primary T cells in vitro. In this study, we report that an application using anti-CD3 and anti-CD28 Abs conjugated on lipid microbubbles (microbubble-based human T cell activator [MB-TCA]) to stimulate primary human naive T cells resulted in expansion superior to D-TCA. In 56-d cultures with three repeated stimulation cycles (14 d per stimulation), we found that 1) MB-TCA induced significantly better expansion (20- and 10-fold increase) of naive CD4+ and CD8+ T cells than did D-TCA; 2) MB-TCA– and D-TCA–stimulated T cells had a similar number of initial cell divisions, but MB-TCA had significantly lower activation-induced cell death than D-TCA; 3) MB-TCA–stimulated T cells produced less TNF-α than did D-TCA; and 4) blocking TNF-α action via adding an Ab against TNF-αR (TNFRSF1A) significantly improved expansion of T cells activated by D-TCA in vitro. Together, we demonstrated that the MB-TCA induces a better expansion of human naive T cells in vitro and offers advantages in both basic and clinical applications in which the outcome depends on the number of T cells.
A Population of Injury-Responsive Lymphoid Cells Expresses mpeg1.1 in the Adult Zebrafish Heart
Authors: Moyse Bethany R , Richardson Rebecca J
Published: August 2020

Transgenic zebrafish that express fluorophores under the control of mpeg1.1 (mpeg1) and csf1ra (c-fms) promoters have been widely used to study the dynamics and functions of mononuclear phagocytes (MNPs) in larval zebrafish, unveiling crucial roles for these innate immune cells in many processes, including tissue repair. Adult zebrafish are also being increasingly used as a model organism for such studies because of their regenerative capacity and presence of innate and adaptive immune cells. For example, recent investigations highlight roles of MNPs in the regulation of diverse cellular processes during heart regeneration, including scarring, cardiomyocyte proliferation, and neovascularization. However, transgenic lines that stratify MNP subpopulations (monocytes, macrophages, and dendritic cells) are not yet available, preventing functional analysis of these populations. In an attempt to better segregate cardiac MNPs, we assessed the coexpression of mpeg1.1 and csf1ra reporter transgenes in adult zebrafish hearts. Unexpectedly, this also identified a discrete population of mpeg1.1+csf1ra− lymphoid-like cells, which respond to cardiac cryoinjury in a different temporal pattern to mpeg1.1+ MNPs. mpeg1.1+ lymphoid cells were also abundant in the skin, spleen, and blood, and their frequency was unaffected in the hearts of csf1raj4e1/j4e1 mutant zebrafish, which display deficiencies in MNP populations. Flow cytometry, imaging, and cytological and gene expression analyses collectively indicate that these cells comprise a mixed population of B cells and NK-like cells. Our study therefore highlights the need to identify novel MNP lineage markers but also suggests undetermined roles of B cells and NK-like cells in cardiac homeostasis and repair in adult zebrafish.
A Point Mutation Creating a 3′ Splice Site in C8A Is a Predominant Cause of C8α-γ Deficiency in African Americans
Authors: Densen Peter , Ackermann Laynez , Saucedo Leslie , Figueroa Julio E. , Si Zhi-hai , Stoltzfus Conrad Martin
Published: August 2020

C8α-γ deficiency was examined in four unrelated African Americans. Two individuals were compound heterozygotes for a previously reported point mutation in exon 9. mRNA from the remaining six C8A alleles contained a 10 nt insertion between nt 992 and 993 corresponding to the junction between exons 6 and 7. This suggested that C8α-γ deficiency in these individuals was caused by a splicing defect. Genomic sequencing revealed a G→A point mutation in intron 6, upstream of the exon 7 acceptor site. This mutation converts a GG to an AG, generates a consensus 3′ splice site that shifts the reading frame, and creates a premature stop codon downstream. To verify that the point mutation caused a splicing defect, we tested wild-type and mutant mRNA substrates, containing 333 nt of the C8α intron 6/exon 7 boundary, in an in vitro splicing assay. This assay generated spliced RNA containing the 10 bp insertion observed in the C8α mRNA of affected patients. In addition, in mutant RNA substrates, the new 3′ splice site was preferentially recognized compared with wild-type. Preferential selection of the mutant splice site likely reflects its positioning adjacent to a polypyrimidine tract that is stronger than that adjacent to the wild-type site. In summary, we have identified a G→A mutation in intron 6 of C8A as a predominant cause of C8α-γ deficiency in African Americans. This mutation creates a new and preferred 3′ splice site, results in a 10 nt insertion in mRNA, shifts the reading frame, and produces a premature stop codon downstream.
An Ultrahigh-Affinity Complement C4b-Specific Nanobody Inhibits In Vivo Assembly of the Classical Pathway Proconvertase
Authors: Zarantonello Alessandra , Presumey Jessy , Simoni Léa , Yalcin Esra , Fox Rachel , Hansen Annette , Olesen Heidi Gytz , Thiel Steffen , Johnson Matthew B. , Stevens Beth , Laursen Nick Stub , Carroll Michael C. , Andersen Gregers R.
Published: August 2020

The classical and lectin pathways of the complement system are important for the elimination of pathogens and apoptotic cells and stimulation of the adaptive immune system. Upon activation of these pathways, complement component C4 is proteolytically cleaved, and the major product C4b is deposited on the activator, enabling assembly of a C3 convertase and downstream alternative pathway amplification. Although excessive activation of the lectin and classical pathways contributes to multiple autoimmune and inflammatory diseases and overexpression of a C4 isoform has recently been linked to schizophrenia, a C4 inhibitor and structural characterization of the convertase formed by C4b is lacking. In this study, we present the nanobody hC4Nb8 that binds with picomolar affinity to human C4b and potently inhibits in vitro complement C3 deposition through the classical and lectin pathways in human serum and in mouse serum. The crystal structure of the C4b:hC4Nb8 complex and a three-dimensional reconstruction of the C4bC2 proconvertase obtained by electron microscopy together rationalize how hC4Nb8 prevents proconvertase assembly through recognition of a neoepitope exposed in C4b and reveals a unique C2 conformation compared with the alternative pathway proconvertase. On human induced pluripotent stem cell–derived neurons, the nanobody prevents C3 deposition through the classical pathway. Furthermore, hC4Nb8 inhibits the classical pathway-mediated immune complex delivery to follicular dendritic cells in vivo. The hC4Nb8 represents a novel ultrahigh-affinity inhibitor of the classical and lectin pathways of the complement cascade under both in vitro and in vivo conditions.
Influences of variable Anteseden functional Integrity Examiner on quality tax inspection
Authors: Roem H Muhammad Kasman , Su'un Muhammad , Ahmad Hamzah
Published: August 2020

The study aims to assess the impact of competence on the integrity of tax inspectors and the quality of tax inspection, competence on the quality of tax inspection through the integrity of tax inspectors, independence of the integrity of tax inspectors and quality of tax checks and the impact of integrity on the quality of tax inspection This research uses the method of descriptive analysis and path analysis with a sample number of 80 respondents. This research  finds that competence have a direct positive  and  significant influence on the integrity  and quality of the examination. Competence positively and significantly affect the quality of tax inspection through integrity. Independence has a significant positive direct influence on the integrity   and quality of tax checks. Independence has positive and significant effect on the quality of tax inspection through integrity and Direct positive integrity, but not significant to the quality of tax inspection.
Several factors influence the willingness to Pay taxes
Authors: Ali Isnaeni , Nasaruddin Fadliah
Published: August 2020

This study aims to analyze and examine the Factors Affecting the Will to Pay Taxes at the West Makassar Pratama Tax Office. The independent variable in this research is Tax Knowledge, Fiscus Services and Tax Examination while the dependent variable is Tax Paying Will. The research method used in this research is descriptive analysis and Multiple Linear Regression analysis, with a total sample of 100 respondents. The results showed that simultaneous and partial knowledge of taxation, tax services and tax audits had a significant positive effect on the willingness to pay taxes at the West Makassar Pratama Tax Office
Does the Institutional ownership, Return On Asset and Leverage affect Company Value
Authors: Mira
Published: August 2020

This study aims to determine the effect of institutional ownership, return on assets (ROA) and leverage on firm value. Testing is done using secondary data in the form of financial statements of manufacturing companies listed on the IDX. Data were analyzed using Multiple regression with SPSS 24.0. The managerial implication of this research is the large number of institutional ownership can encourage an increase and optimal oversight. A high ROA value will give a positive signal to investors that the company can generate large profits so that it becomes an attraction for investors to own company shares and will increase share prices and have an impact on increasing company value. High leverage becomes a positive signal for the market or potential investors and shows that manufacturing industry companies have applied the concept of trade of theory which means that companies whose capital structure is derived from debt and still benefit, the use of debt is the right alternative. But at some point an increase in debt will reduce the value of the company because the benefits derived from the use of debt are smaller than the costs incurred
Environmental audit analysis to support Sustainability Development
Authors: Fitria Ningsih Desy , Junaid Asriani , Mursalim Mursalim
Published: August 2020

The focus of this study is to determine how the implementation of environmental audits based on triple bottom line theory and to determine the application of environmental audits to support sustainability development at the Bahteramas Regional Hospital. This research uses primary and secondary data. Primary data in the form of direct interviews with the company designated as an informant, while secondary data in the form of data obtained from company internal data. The method used is a qualitative method based on the interpretive paradigm. The results of the study found that the Bahteramas Hospital had the maximum in expressing costs to the environment in detail in the financial statement notes, but the costs incurred were still included in the maintenance burden category. The accounting practices that have been applied by Bahteramas Hospital have been maximized in implementing environmental audits. Activities that have been carried out by the company in terms of the environment, economy, and social aspects can already be said to support sustainable development.
Caseload and Workload: Current Trends in School-Based Practice Across the United States
Authors: Seruya Francine M. , Garfinkel Mindy
Published: August 2020

Importance: Practitioners working in school settings have a variety of job-related responsibilities in addition to direct service provision. Models of best practice indicate that a workload approach to service delivery allows practitioners to provide effective and productive interventions in the school setting; however, current information related to service delivery by school-based practitioners in the United States is lacking.

Objective: To explore current caseloads, service delivery models, implementation of workload models, knowledge of state and local policies, and job satisfaction of school-based occupational therapy practitioners and how they relate to best practice.

Design: Web-based survey.

Setting: School-based practice.

Participants: Three hundred seventy-one school-based practitioners from across the United States completed the study.

Outcomes and Measures: Investigator-developed survey with both closed- and open-ended questions.

Results: School-based practitioners recruited via social media platforms and snowball sampling completed an online survey. Results indicate that practitioners wanted to move their practice to a workload model but cited lack of administrative support, time, procedural knowledge, and decreased advocacy skills as barriers to implementation. Moreover, despite current philosophy regarding best practice, occupational therapy practitioners continue to provide services outside of the classroom and other natural settings.

Conclusions and Relevance: There seems to be a disconnect between intent (e.g., service delivery in natural settings, expanding the scope of practice) and current practice trends. Practitioners need support to advocate for and implement alternative service delivery models and to incorporate a workload approach to meet the diverse needs of students in educational settings.

What This Article Adds: Practical resources related to caseload and workload guidelines and implementation, service delivery models, and methods of advocacy and negotiation skills are needed to support practitioners as they advocate for changes in their practice.
Airborne pollen observations using a multi-wavelength Raman
polarization lidar in Finland: characterization of pure pollen types
Authors: Shang Xiaoxia , Giannakaki Elina , Bohlmann Stephanie , Filioglou Maria , Saarto Annika , Ruuskanen Antti , Leskinen Ari , Romakkaniemi Sami , Komppula Mika
Published: August 2020

Abstract. We present a novel algorithm for characterizing the optical properties of pure pollen particles, based on the depolarization values obtained in lidar measurements. The algorithm was first tested and validated through a simulator, and then applied to the lidar observations during a four-month pollen campaign from May to August 2016 at the European Aerosol Research Lidar Network (EARLINET) station in Kuopio (62°44′ N, 27°33′ E), in Eastern Finland. Twenty types of pollen were observed and identified from concurrent measurements with Burkard sampler; Birch (Betula), pine (Pinus), spruce (Picea) and nettle (Urtica) pollen were most abundant, contributing more than 90 % of total pollen load, regarding number concentrations. Mean values of lidar-derived optical properties in the pollen layer were retrieved for four intense pollination periods (IPPs). Lidar ratios at both 355 and 532 nm ranged from 55 to 70 sr for all pollen types, without significant wavelength-dependence. Enhanced depolarization ratio was found when there were pollen grains in the atmosphere, and even higher depolarization ratio (with mean values of 25 % or 14 %) was observed with presence of the more non-spherical spruce or pine pollen. The depolarization ratio at 532 nm of pure pollen particles was assessed, resulting to 24 ± 3 % and 36 ± 5 % for birch and pine pollen, respectively. Pollen optical properties at 1064 nm and 355 nm were also estimated. The backscatter-related Ångström exponent between 532 and 1064 nm was assessed as ~ 0.8 (~ 0.5) for pure birch (pine) pollen, thus the longer wavelength would be better choice to trace pollen in the air. The pollen depolarization ratio at 355 nm of 17 % and 30 % were found for birch and pine pollen, respectively. The depolarization values show a wavelength dependence for pollen. This can be the key parameter for pollen detection and characterization.
Ecosystem physio-phenology revealed using circular statistics
Authors: Pabon-Moreno Daniel E. , Musavi Talie , Migliavacca Mirco , Reichstein Markus , Römermann Christine , Mahecha Miguel D.
Published: August 2020

Abstract. Quantifying how vegetation phenology responds to climate variability is a key prerequisite to
predicting how ecosystem dynamics will shift with climate change. So far, many studies have focused
on responses of classical phenological events (e.g., budburst or flowering) to climatic variability
for individual species. Comparatively little is known on the dynamics of physio-phenological
events such as the timing of maximum gross primary production (DOYGPPmax),
i.e., quantities that are relevant for understanding terrestrial carbon cycle responses to climate
variability and change. In this study, we aim to understand how DOYGPPmax
depends on climate drivers across 52 eddy covariance (EC) sites in the FLUXNET network for
different regions of the world. Most phenological studies rely on linear methods that cannot be
generalized across both hemispheres and therefore do not allow for deriving general rules that can
be applied for future predictions. One solution could be a new class of circular–linear (here
called circular) regression approaches. Circular regression allows circular variables (in
our case phenological events) to be related to linear predictor variables as climate conditions. As a proof of
concept, we compare the performance of linear and circular regression to recover original
coefficients of a predefined circular model for artificial data. We then quantify the sensitivity
of DOYGPPmax across FLUXNET sites to air temperature, shortwave incoming
radiation, precipitation, and vapor pressure deficit. Finally, we evaluate the predictive power of
the circular regression model for different vegetation types. Our results show that the joint
effects of radiation, temperature, and vapor pressure deficit are the most relevant controlling
factor of DOYGPPmax across sites. Woody savannas are an exception, where the
most important factor is precipitation. Although the sensitivity of the
DOYGPPmax to climate drivers is site-specific, it is possible to generalize
the circular regression models across specific vegetation types. From a methodological point of
view, our results reveal that circular regression is a robust alternative to conventional
phenological analytic frameworks. The analysis of phenological events at the global scale can benefit
from the use of circular statistics. Such an approach yields substantially more robust results
for analyzing phenological dynamics in regions characterized by two growing seasons per year or
when the phenological event under scrutiny occurs between 2 years
(i.e., DOYGPPmax in the Southern Hemisphere).
University of Kentucky measurements of wind, temperature, pressure and humidity in support of LAPSE-RATE using multisite fixed-wing and rotorcraft unmanned aerial systems
Authors: Bailey Sean C. C. , Sama Michael P. , Canter Caleb A. , Pampolini L. Felipe , Lippay Zachary S. , Schuyler Travis J. , Hamilton Jonathan D. , MacPhee Sean B. , Rowe Isaac S. , Sanders Christopher D. , Smith Virginia G. , Vezzi Christina N. , Wight Harrison M. , Hoagg Jesse B. , Guzman Marcelo I. , Smith Suzanne Weaver
Published: August 2020

Abstract. In July 2018, unmanned aerial systems (UASs) were deployed to measure the properties of the lower atmosphere within the San Luis Valley, an elevated valley in Colorado, USA, as part of the Lower Atmospheric Profiling Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE). Measurement objectives included detailing boundary layer transition, canyon cold-air drainage and convection initiation within the valley. Details of the contribution to LAPSE-RATE made by the University of Kentucky are provided here, which include measurements by seven different fixed-wing and rotorcraft UASs totaling over 178 flights with validated data. The data from these coordinated UAS flights consist of thermodynamic and kinematic variables (air temperature, humidity, pressure, wind speed and direction) and include vertical profiles up to 900 m above the ground level and horizontal transects up to 1500 m in length. These measurements have been quality controlled and are openly available in the Zenodo LAPSE-RATE community data repository (https://zenodo.org/communities/lapse-rate/, last access: 23 July 2020), with the University of Kentucky data available at https://doi.org/10.5281/zenodo.3701845 (Bailey et al., 2020).
School students from all backgrounds can do physics research: On the accessibility and equity of the PRiSE approach to independent research projects
Authors: Archer Martin O.
Published: August 2020

Abstract. Societal biases are a major issue in school students' access to and interaction with science. Schools engagement programmes in science from universities, like independent research projects, which could try and tackle these problems are, however, often inequitable. We evaluate these concerns applied to one such programme, Physics Research in School Environments (PRiSE), which features projects in space science, astronomy, and particle physics. Comparing the schools involved with PRiSE to those of other similar schemes and UK national statistics, we find that PRiSE has engaged a much more diverse set of school students and significantly more disadvantaged groups than is typical. While drop-off occurs within the protracted programme, we find no evidence of systematic biases present. The majority of schools that complete projects return for multiple years of the programme, with this repeated buy-in from schools again being unpatterned by typical societal inequalities. Therefore, school students' ability to succeed at independent research projects appears independent of background within the PRiSE framework. Qualitative feedback from teachers show that the diversity and equity of the programme, which they attribute to the level of support offered through PRiSE, is valued and they have highlighted further ways of making the projects potentially even more accessible. Researcher-involvement, uncommon in many other programmes, along with teacher engagement and communication are found to be key elements to success in independent research projects overall.
Soil salinization risk assessment owing to poor water quality drip irrigation: A case study from an olive plantation at the arid to semi-arid Beit She'an Valley, Israel
Authors: Mirlas Vladimir , Anker Yaakov , Aizenkod Asher , Goldshleger Naftali
Published: August 2020

Abstract. Salinization causes soil degradation and soil fertility reduction. The main reasons for soil salinization are poor irrigation water quality and incorrect irrigation management. Soil salinization is accelerated owing to irrigation with treated wastewater with elevated salt concentration. The study area is located in the Beit She'an Valley, one of the most important agricultural regions in Israel. The combination of soil salinization and poor drainage conditions impedes plant development and is manifested in economic damage to crops. Without clear irrigation criteria, an increase in soil salinity and steady damage to soil fertility might occur. The study objective was to provide an assessment of soil salting processes as a result of low-quality irrigation water at the Kibbutz Meirav olive plantation. This study combined various research methods, including soil salinity monitoring, field experiments, remote sensing (FDEM), and unsaturated soil profile saline water movement modeling. The assessment included the salinization processes of chalky soil under drip irrigation by water with various qualities. With a drip irrigation regime of water with a dissolved salt content of 3.13 dS/m, the salinization process is characterized by salts accumulation in the upper root zone of the trees. The modeling results showed that there is a soil salinization danger in using brackish water and that irrigation with potable water helps to reduce soil salinization.
UAV LIDAR DATA PROCESSING: INFLUENCE OF FLIGHT HEIGHT ON GEOMETRIC ACCURACY, RADIOMETRIC INFORMATION AND PARAMETER SETTING IN DTM PRODUCTION
Authors: Bakuła K. , Pilarska M. , Ostrowski W. , Nowicki A. , Kurczyński Z.
Published: August 2020

Abstract. This article presents the results of studies related to the impact of flight altitude of UAV equipped with lidar data on geometric and radiometric information. Experiments were conducted in two test areas by performing UAV test flight missions at different UAV Laser Scanner (ULS) altitudes. The results were compared to other parameters describing the point clouds in order to answer the questions related to their genesis and evaluation of a product from such high-resolution datasets. The accuracy of the elevation models was assessed on the basis of control points measured with GNSS RTK and Terrestrial Laser Scanning (TLS). Accuracy was assessed by statistical parameters and differential digital elevation models. The second issue raised in this work is the study of the decrease in radiometric value with an increase in platform elevation. The results of this work clearly indicate the very low impact of platform altitude on DTM vertical error. In presented works the suggestion about DTM resolution and interpolation method are provided. Moreover, the influence of flight height on the reflectance and intensity is notable, however, its impact is related more with the details and resolution of the raster than radiometric values considering the possibility of radiometric calibration of the intensity.
PRECISION OF VISUAL LOCALIZATION USING DYNAMIC GROUND CONTROL POINTS
Authors: Trusheim P. , Heipke C.
Published: August 2020

Abstract. Localization is one of the first steps in navigation. Especially due to the rapid development in automated driving, a precise and reliable localization becomes essential. In this paper, we report an investigation of the usage of dynamic ground control points (GCP) in visual localization in an automotive environment. Instead of having fixed positions, dynamic GCPs move together with the camera. As a measure of quality, we employ the precision of the bundle adjustment results. In our experiments, we simulate and investigate different realistic traffic scenarios. After investigating the role of tie points, we compare an approach using dynamic GCPs to an approach with static GCPs to answer the question how a comparable precision can be reached for visual localization. We show, that in our scenario, where two dynamic GCPs move together with a camera, similar results are indeed obtained to using a number of static GCPs distributed over the whole trajectory. In another experiment, we take a closer look at sliding window bundle adjustments. Sliding windows make it possible to work with an arbitrarily large number of images and to still obtain near real-time results. We investigate this approach in combination with dynamic GCPs and vary the no. of images per window.
GAN-BASED SYNTHESIS OF DEEP LEARNING TRAINING DATA FOR UAV MONITORING
Authors: Langenkämper D. , van Kevelaer R. , Möller T. , Nattkemper T. W.
Published: August 2020

Abstract. Wind energy is a critical part of overcoming the use of fossil or nuclear energy usage. The price pressure on the renewable industry sector demands to cut the costs for costly regular inspections carried out by industrial climbers. Drone-based video-inspection reduces costs as well as increases the safety of inspection personal. To further increase the throughput, automatic or semi-automatic solutions to analyze these videos are needed. However, modern machine learning architectures need a lot of data to work reliably. This is by design a problem, as structural damage is rather rare in industrial infrastructure. Our proposed approach uses Generative Adversarial Networks to generate synthetic unmanned aerial vehicle imagery. This allows us to create a large enough training dataset (> 103) from a dataset, which is at least an order of magnitude smaller (approx. 102). We show that we can increase the classification accuracy of up to 6 percentage points.
INTERACTION BETWEEN DIRECT GEOREFERENCING, CONTROL POINT CONFIGURATION AND CAMERA SELF-CALIBRATION FOR RTK-BASED UAV PHOTOGRAMMETRY
Authors: Przybilla H.-J. , Bäumker M. , Luhmann T. , Hastedt H. , Eilers M.
Published: August 2020

Abstract. Unmanned Aerial Vehicles (UAV) are enjoying increasing popularity in the photogrammetric community. The Chinese supplier DJI is the market leader with about 70% of the global consumer UAV market. The Phantom model has been available for more than 10 years and its current version "RTK" is equipped with a 2-frequency GNSS receiver, as a basis for direct georeferencing of image flights, using RTK or PPK technologies.In the context of the paper, different case studies are investigated, which allow statements on the geometric accuracy of UAV image flights as well as on the self-calibration of the camera systems.In the first example, four DJI Phantom 4 RTK systems are examined, which were flown in a cross flight pattern configuration on the area of the UAV test field "Zeche Zollern" in Dortmund, Germany. The second example analyses the results of an open moorland area where the establishment of GCPs is extremely difficult and expensive, hence direct georeferencing offers a promising way to evaluate deformations, soil movements or mass calculations. In this example a DJI Matrice 210 v2 RTK drone has been used and the results of two different software packages (Agisoft Metashape and RealityCapture) are analysed. The third example presents a reference building that has been established by the Lower Saxony administration for geoinformation in order to evaluate UAV photogrammetry for cadastral purposes. Here again a DJI Phantom 4 RTK has been tested in a variety of flight configurations and a large number of high precision ground control and check points.The case studies show that the RTK option leads to sufficient results if at least 1 GCP is introduced. Flights without any GCPs lead to a significant height error in the order of up to 30 GSD.
INTEGRATION OF MULTITEMPORAL SENTINEL-1 AND SENTINEL-2 IMAGERY FOR LAND-COVER CLASSIFICATION USING MACHINE LEARNING METHODS
Authors: Dobrinić D. , Medak D. , Gašparović M.
Published: August 2020

Abstract. Using space-borne remote sensing data is widely used for land-cover classification (LCC) due to its ability to provide a big amount of data with a regular temporal revisit time. In recent years, optical and synthetic aperture radar (SAR) imagery have become available for free, and their integration in time series have improved LCC. This research evaluates the classification accuracy using multitemporal (MT) Sentinel-1 (S1) and Sentinel-2 (S2) imagery. Pixel-based LCC is made for S1 and S2 imagery, and for a combination of both datasets with Random Forest (RF) and Extreme Gradient Boosting (XGBoost; XGB). The extent of the study area, is located in the south-east of France, in Lyon. Regardless of LCC using single-date or MT data, the highest classification results were achieved with integrated S1 and S2 imagery and XGB method, whereas overall accuracy (OA) and Kappa coefficient (Kappa) increased from 85.51% to 91.09%, and from 0.81 to 0.88, respectively. Furthermore, the integration of MT imagery significantly improved the classification of urban areas and reduced misclassification between forest and low vegetation. In this paper, in terms of the pixel-based classification, XGB produced slightly better results than RF, and outperformed it in terms of computational time. This research improved LCC with integration of radar and optical MT imagery, which can be useful for areas hampered by a frequent cloud cover. Future work should use the aforementioned data for specific applications in remote sensing, as well as evaluate the classification performance with different approaches, such as neural networks or deep learning.
Wind variability in the Canary Current during the last 70 years
Authors: Marrero-Betancort Nerea , Marcello Javier , Rodríguez Esparragón Dionisio , Hernández-León Santiago
Published: August 2020

Abstract. Climate evolves following natural variability, and
knowledge of these trends is of paramount importance to understand future
scenarios in the frame of global change. Obtaining local data is also of
importance since climatic anomalies depend on the geographical area. In this
sense, the Canary Current is located in one of the major eastern boundary
current systems and is mainly driven by the trade winds. The latter promote
Ekman transport and give rise to one of the most important upwelling zones
of the world on the northwest African coast. Nearly 30 years ago, Bakun (1990)
raised a hypothesis contending that coastal upwelling in eastern boundary
upwelling systems (EBUSs) might be intensified by global warming due to the
enhancement of the trade winds, increasing pressure differences between the
ocean and the continent. Using available NCEP/NCAR wind data north of the
Canary Islands from 1948 to 2017, we show that trade wind intensity
experienced a net decrease of 1 m s−1. Moreover, these winds
are strongly influenced, as expected, by large-scale atmospheric
patterns such as the North Atlantic Oscillation (NAO). In addition, we
found a relationship between the wind pattern and the Atlantic Multidecadal
Oscillation (AMO), indicating that the ocean contributes to multidecadal
atmospheric variability in this area of the ocean with a considerable lag
(>10 years).