scholarly journals Mechanistic modeling of pesticide uptake with a 3D plant architecture model

2021 ◽  
Author(s):  
Helena Jorda ◽  
Katrin Huber ◽  
Asta Kunkel ◽  
Jan Vanderborght ◽  
Mathieu Javaux ◽  
...  
Keyword(s):  
Root Zone ◽  
Mechanistic Model ◽  
Chemical Properties ◽  
Mechanistic Modeling ◽  
The European Union ◽  
Architecture Model ◽  
Solute Uptake ◽  
Uptake Process ◽  
Set Up ◽  
Pesticide Registration

AbstractMeaningful assessment of pesticide fate in soils and plants is based on fate models that represent all relevant processes. With mechanistic models, these processes can be simulated based on soil, substance, and plant properties. We present a mechanistic model that simulates pesticide uptake from soil and investigate how it is influenced, depending on the governing uptake process, by root and substance properties and by distributions of the substance and water in the soil profile. A new root solute uptake model based on a lumped version of the Trapp model (Trapp, 2000) was implemented in a coupled version of R-SWMS-ParTrace models for 3-D water flow and solute transport in soil and root systems. Solute uptake was modeled as two individual processes: advection with the transpiration stream and diffusion through the root membrane. We set up the model for a FOCUS scenario used in the European Union (EU) for pesticide registration. Considering a single vertical root and advective uptake only, the root hydraulic properties could be defined so that water and substance uptake and substance fate in soil showed a good agreement with the results of the 1D PEARL model, one of the reference models used in the EU for pesticide registration. Simulations with a complex root system and using root hydraulic parameters reported in the literature predicted larger water uptake from the upper root zone, leading to larger pesticide uptake when pesticides are concentrated in the upper root zone. Dilution of root water concentrations at the top root zone with water with low pesticide concentration taken up from the bottom of the root zone leads to larger uptake of solute when uptake was simulated as a diffusive process. This illustrates the importance of modeling uptake mechanistically and considering root and solute physical and chemical properties, especially when root-zone pesticide concentrations are non-uniform.

scholarly journals Mechanistic modeling of pesticide uptake with a 3D plant architecture model

2021 ◽  
Author(s):  
Helena Jorda ◽  
Katrin Huber ◽  
Asta Kunkel ◽  
Jan Vanderborght ◽  
Mathieu Javaux ◽  
...  
Keyword(s):  
Root Zone ◽  
Chemical Properties ◽  
Mechanistic Modeling ◽  
The European Union ◽  
Architecture Model ◽  
Single Root ◽  
Solute Uptake ◽  
Physical And Chemical ◽  
And Diffusion ◽  
Good Agreement

Abstract A new root solute uptake model based on a lumped version of the Trapp model (Trapp, 2000) was implemented in a coupled version of R-SWMS-ParTrace models for 3-D water flow and solute transport in soil and roots. Solute uptake was modeled as two individual processes: advection with the transpiration stream and diffusion through the root membrane. We parameterized the model for a FOCUS scenario used in the European Union for pesticide registration. Simulation with a single root showed a good agreement with the results produced by the 1D PEARL model. Simulations with a complex root system predicted larger water uptake from the upper root zone, leading to larger pesticide uptake when pesticides are concentrated in the upper root zone. Dilution of root water concentrations at the top root zone with water with low pesticide concentration taken up from the bottom of the root zone lead to larger uptake of solute when uptake was simulated as a diffusive process. This illustrates the importance of modeling uptake mechanistically and considering root and solute physical and chemical properties, especially when root-zone pesticide concentrations are non uniform.

scholarly journals Mechanistic modeling of persistent organic pollutant exposure among indigenous Arctic populations: motivations, challenges, and benefits

2017 ◽  
Vol 25 (4) ◽  
pp. 396-407 ◽  
Author(s):  
F. Wania ◽  
M.J. Binnington ◽  
M.S. Curren
Keyword(s):  
Mechanistic Model ◽  
Organic Pollutant ◽  
Temporal Trends ◽  
Chemical Properties ◽  
Mechanistic Modeling ◽  
The Arctic ◽  
Contaminant Exposure ◽  
Beluga Whales ◽  
Sequence Of Events ◽  
Food Species

Indigenous Arctic populations experience elevated exposures to many environmental contaminants compared with groups residing in southern Canada. This is largely due to consumption of traditional foods, some of which (ringed seals, beluga whales, narwhals, etc.) have relatively high concentrations of persistent organic pollutants. Models of contaminant fate, transport, and bioaccumulation represent powerful tools to explore this exposure issue, wherein combined models can be used to mechanistically and dynamically describe the entire sequence of events linking chemical emissions into the environment to ultimate contaminant concentrations in indigenous Arctic populations. In this review, various approaches adapted and applied to understanding indigenous Arctic contaminant exposure are explored, including early models describing body burdens in single traditional food species to more recent approaches holistically examining uptake and bioaccumulation in entire food chains. The applications of these models are also discussed, including attempts to (i) identify chemical properties favouring transport to, and bioaccumulation in, the Arctic; (ii) clarify the main determinants of temporal trends observed in indigenous Arctic biomonitoring; (iii) explore the impacts of permanent and temporary dietary transitions on current and future indigenous Arctic contaminant exposures; and (iv) correlate modeled early-life pollutant exposures with measured health impacts. The review demonstrates the effectiveness of mechanistic model approaches in investigating indigenous Arctic contaminant exposure, and confirms their utility in continued improvements to understanding associated risk in this unique population context.

INVESTIGATION OF EROSION RESISTANCE OF GRAY-BROWN SOILS IN THE SOUTHEASTERN SLOPES OF THE GREATER CAUCASUS

2020 ◽  
pp. 47-49
Author(s):  
Aliyev Z.H.
Keyword(s):  
Erosion Resistance ◽  
Preventive Measures ◽  
Chemical Properties ◽  
Anthropogenic Factors ◽  
Erosion Process ◽  
Greater Caucasus ◽  
Sloping Lands ◽  
Set Up ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, sharp changes have occurred in the state of sloping lands of Azerbaijan. There was tension from the influence of the anthropogenic factors on the mountain slopes. The fact that the erosion process is rein-forced in the research site. Due to lack of agrotechnical measures on the slopes erosion process has been strength-ened, soil flooded with soil, physical and chemical properties of the soil have deteriorated, nutritional elements are reduced, vegetation is reduced and destruction limit. For some reason, the purpose of the research was Aqsu, two land cuts were set up to determine the degree of actual erosion in the Qizmeydan village. prevent erosion intensity, take preventive measures to take and implement appropriate measures.

scholarly journals The profile of vulnerable students using the university psychosocial and medical care services

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
M Papadakaki ◽  
F Sarakatsianou ◽  
V Tsismeli ◽  
G Lapidakis ◽  
M Karapiperaki
Keyword(s):  
Higher Education ◽  
Family Income ◽  
Psychosocial Support ◽  
Academic Progress ◽  
Health Examination ◽  
The European Union ◽  
Psychosocial Needs ◽  
Development Education ◽  
Medical Unit ◽  
Set Up

Abstract Background Increasing the capacity of higher education institutes to address students' vulnerabilities has been deemed necessary due to the financial crisis. Multilevel interventions have thus been initiated at the Hellenic Mediterranean University of Crete, as part of a project co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme <<Human Resources Development, Education and Lifelong Learning 2014- 2020 >> (MIS 5045937). The project aims to offer support to students with low family income or a certified disability, monitor their bio-psychosocial needs, increase their accessibility to health and psychosocial care, and improve their academic outcomes. Methods As part of the project, a primary health care unit has been set up to offer medical and nursing care (medical unit) as well as psychosocial support (counseling centre) to students in need. An observatory has also been set up to monitor their health and psychosocial needs and their academic progress. Results A total of 228 eligible students used the services in the second half of 2019 (counseling centre 37; medical unit 191). Out of the 37 individuals who used the counseling centre, 30 (81.0%) were female and 16 (43.2%) were at the first 2 years of their studies. A total of 36 (97.3%) requested psychological support, 6 (16.2%) warranted social welfare services and 1 (2.7%) support for learning disabilities. As for the 191 individuals who used the medical services, 101 (52.8%) were male and 88 (46.0%) were at first 2 years of their studies. Most of them had a health examination to receive a health certificate (74.8%) followed by those who received emergency care (e.g. respiratory infection, allergic reaction, injury, etc), chronic disease management and medicine subscription, as well as vaccination. Conclusions Complex bio-psychosocial needs have been identified, recorded and analyzed to explain the academic progress of socially vulnerable students. Key messages The students’ journey through medical and counseling services is being mapped to offer important information for educational policy. Assessment and monitoring of students’ complex needs are important to achieve quality in higher education.

scholarly journals Electrospinning: A promising technique for drug delivery systems

2020 ◽  
Vol 59 (1) ◽  
pp. 441-454
Author(s):  
Carlos A. Martínez-Pérez
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Chemical Properties ◽  
Delivery Systems ◽  
Extrinsic Factor ◽  
Promising Technique ◽  
Physical Chemical ◽  
Set Up ◽  
Final System ◽  
Intense Research

AbstractIn the last years, electrospinning has become a technique of intense research to design and fabricate drug delivery systems (DDS), during this time a vast variety of DDS with mainly electrospun polymers and many different active ingredient(s) have been developed, many intrinsic and extrinsic factor have influence in the final system, there are those that can be attributed to the equipment set up and that to the physical-chemical properties of the used materials in the fabrication of DDS. After all, this intense research has generated a great amount of DDS loaded with one or more drugs. In this manuscript a review with the highlights of different kind of systems for drug delivery systems is presented, it includes the basic concepts of electrospinning, types of equipment set up, polymer/drug systems, limitations and challenges that need to be overcome for clinical applications.

scholarly journals European Union One Health Country Visits as Driver to Combat on Antimicrobial Resistance

2020 ◽  
Vol 41 (S1) ◽  
pp. s222-s222
Author(s):  
Pita Spruijt ◽  
Paul Bergervoet ◽  
Robbin Westerhof ◽  
Merel Langelaar ◽  
Marie-Cécile Ploy
Keyword(s):  
European Union ◽  
Antimicrobial Resistance ◽  
Peer Review ◽  
Infection Prevention ◽  
One Health ◽  
Competent Authority ◽  
Political Agenda ◽  
The European Union ◽  
Review System ◽  
Set Up

Background: In 2016, the European Union adopted unanimously Council Conclusions on the next steps to combat antimicrobial resistance under a One Health approach. To implement some of the provisions laid down in the Council Conclusions, a European Joint Action on Antimicrobial Resistance (AMR) and Healthcare-Associated Infections (HCAI) or EU-JAMRAI was set up, gathering 44 partners. Methods: As part of EU-JAMRAI, 13 participating European countries set up a country-to-country peer review system to evaluate each other’s national action plans (NAPs). This review system entailed a self-assessment, strengths–weaknesses–opportunities–threats (SWOT) analysis, and country visits. All steps were executed with representatives from both the human and the veterinary domains (One Health approach). Special attention was given to supervision and the way supervision can enhance the implementation of guidelines on AMR, both at the policy level and within healthcare institutions. Results: Despite differences in the stage of developing and implementing NAPs, all 13 countries are working on NAPs. In this process, country visits function as a moment to exchange best practices and to provide an outsider’s point of view. At the end of 2019, 13 country-to-country visits had taken place, resulting in tailor-made recommendations for each country. These recommendations were shared with the competent authority. An example is a country that used the recommendation to improve infection prevention as an immediate reason to get the topic on the agenda of the Ministry of Health. During the country visits, intersectoral participation was perceived as desirable, but in some cases it was challenging to arrange. For some highly relevant topics, it has been recognized that discussion should take place on a European level. Examples of such topics include supervision, infection prevention guidelines, funding, surveillance, and regular audits of antibiotic prescriptions for physicians including feedback loops. Conclusions: Peer review is a cooperative and friendly working method compared to common audits. The country visits function as an agenda setting tool to get or to keep AMR on the political agenda and presenting the most relevant topic(s) to address for each country.Funding: NoneDisclosures: None

scholarly journals Joint bodies in the European Union's international agreements: Delegating powers to the European Commission in EU external relations

2021 ◽  
pp. 146511652110273
Author(s):  
Markus Gastinger ◽  
Andreas Dür
Keyword(s):  
European Union ◽  
European Commission ◽  
Empirical Support ◽  
International Agreements ◽  
Principal Agent ◽  
The European Union ◽  
Original Dataset ◽  
Voting Rule ◽  
External Relations ◽  
Set Up

In many international agreements, the European Union sets up joint bodies such as ‘association councils’ or ‘joint committees’. These institutions bring together European Union and third-country officials for agreement implementation. To date, we know surprisingly little about how much discretion the European Commission enjoys in them. Drawing on a principal–agent framework, we hypothesise that the complexity of agreements, the voting rule, conflict within the Council, and agency losses can explain Commission discretion in these institutions. Drawing on an original dataset covering nearly 300 such joint bodies set up by the European Union since 1992, we find robust empirical support for all expectations except for the agency loss thesis. Our findings suggest that the European Commission is the primary actor in the implementation of many of the European Union's international agreements, allowing it to influence EU external relations beyond what is currently acknowledged in the literature.

scholarly journals USE OF SCALED SEMIVARIOGRAMS IN THE PLANNING SAMPLE OF SOIL CHEMICAL PROPERTIES IN SOUTHERN AMAZONAS, BRAZIL

2015 ◽  
Vol 39 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Ivanildo Amorim de Oliveira ◽  
Milton César Costa Campos ◽  
José Marques Junior ◽  
Renato Eleotério de Aquino ◽  
Daniel de Bortoli Teixeira ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Spherical Model ◽  
Exponential Model ◽  
Soil Samples ◽  
Soil Chemical Properties ◽  
Sampling Density ◽  
Sugarcane Crop ◽  
Lack Of Information ◽  
Set Up ◽  
Almost All

The lack of information concerning the variability of soil properties has been a major concern of researchers in the Amazon region. Thus, the aim of this study was to evaluate the spatial variability of soil chemical properties and determine minimal sampling density to characterize the variability of these properties in five environments located in the south of the State of Amazonas, Brazil. The five environments were archaeological dark earth (ADE), forest, pasture land, agroforestry operation, and sugarcane crop. Regular 70 × 70 m mesh grids were set up in these areas, with 64 sample points spaced at 10 m distance. Soil samples were collected at the 0.0-0.1 m depth. The chemical properties of pH in water, OM, P, K, Ca, Mg, H+Al, SB, CEC, and V were determined at these points. Data were analyzed by descriptive and geostatistical analyses. A large part of the data analyzed showed spatial dependence. Chemical properties were best fitted to the spherical model in almost all the environments evaluated, except for the sugarcane field with a better fit to the exponential model. ADE and sugarcane areas had greater heterogeneity of soil chemical properties, showing a greater range and higher sampling density; however, forest and agroforestry areas had less variability of chemical properties.

scholarly journals New perspectives after the transition of EPIET to ECDC – the future of the programme

2009 ◽  
Vol 14 (43) ◽  
Author(s):  
V Bremer ◽  
A Bosman ◽  
D Coulombier
Keyword(s):  
Integrated Approach ◽  
Training Programme ◽  
The European Union ◽  
Member States ◽  
Eu Member States ◽  
European Public ◽  
Response Capacity ◽  
Training Activities ◽  
Set Up ◽  
Training Programmes

Strengthening capacity in intervention epidemiology is key to the overall goal of responding to the challenge to detect and counter threats posed by outbreaks of infectious diseases in the European Union (EU). Since its founding in 1995, the European Programme for Intervention Epidemiology Training (EPIET) has become a core resource in training in intervention epidemiology in the EU. EPIET was integrated into the European Centre for Disease Prevention and Control (ECDC) on 1 November 2007 and this has resulted in an increased sustainability of the programme, allowing for long-term planning. Also, a new training programme, the European public health microbiology training (EUPHEM), was set up in 2008 to increase the response capacity for microbiology. Collaboration with EU Member States and other training programmes has been further intensified. Merging EPIET and other training activities in the ECDC training section has created the opportunity to develop an integrated multilevel approach to training in applied field epidemiology. An integrated approach to training activities on EU level, and increasing the number of EPIET and EPIET-associated fellows are essential to respond to the training needs of EU Member States, particularly new Member States. An external evaluation of EPIET in 2009 will provide guidance for a future strategy for the programme. This article examines the achievements of the EPIET programme after its transition to ECDC and provides an outlook on its future.

scholarly journals Inverse mechanistic modeling of transdermal drug delivery for fast identification of optimal model parameters

2020 ◽  
Author(s):  
Thijs Defraeye ◽  
Flora Bahrami ◽  
Rene M Rossi
Keyword(s):  
Drug Delivery ◽  
Inverse Modeling ◽  
Transdermal Drug Delivery ◽  
Drug Transport ◽  
Mechanistic Model ◽  
Mechanistic Modeling ◽  
Drug Uptake ◽  
Added Value ◽  
Model Parameters ◽  
Transdermal Drug Delivery Systems

Transdermal drug delivery systems are a key technology to administer drugs with a high first-pass effect in a non-invasive and controlled way. Physics-based modeling and simulation are on their way to become a cornerstone in the engineering of these healthcare devices since it provides a unique complementarity to experimental data and insights. Simulations enable to virtually probe the drug transport inside the skin at each point in time and space. However, the tedious experimental or numerical determination of material properties currently forms a bottleneck in the modeling workflow. We show that multiparameter inverse modeling to determine the drug diffusion and partition coefficients is a fast and reliable alternative. We demonstrate this strategy for transdermal delivery of fentanyl. We found that inverse modeling reduced the normalized root mean square deviation of the measured drug uptake flux from 26 to 9%, when compared to the experimental measurement of all skin properties. We found that this improved agreement with experiments was only possible if the diffusion in the reservoir holding the drug was smaller than the experimentally-measured diffusion coefficients suggested. For indirect inverse modeling, which systematically explores the entire parametric space, 30 000 simulations were required. By relying on direct inverse modeling, we reduced the number of simulations to be performed to only 300, so a factor 100 difference. The modeling approach's added value is that it can be calibrated once in-silico for all model parameters simultaneously by solely relying on a single measurement of the drug uptake flux evolution over time. We showed that this calibrated model could accurately be used to simulate transdermal patches with other drug doses. We showed that inverse modeling is a fast way to build up an accurate mechanistic model for drug delivery. This strategy opens the door to clinically-ready therapy that is tailored to patients.

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