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Evaluation of multimodel averaging approaches for ensembling evapotranspiration and yield simulations from maize models
Get PDFCombining multi-model simulations can reduce the uncertainty in model structure and increase the accuracy of agricultural systems modeling results. This improvement is essential for supporting better decision making in irrigation planning and climate change adaptation strategies. Besides the commonly used arithmetic mean and median, many multi-model averaging approaches (MAA), widely examined in groundwater and hydrological modeling, but these additional MAA have not been examined in agricultural system modeling to improve the simulation accuracy. Therefore, the objective of this study is to evaluate the performance of seven MAA: two equal weighted approaches (Simple Model Averaging (SMA) and Median) and five weighted approaches (Inverse Ranking (IR), Bates and Granger Averaging (BGA), and Granger Ramanathan A, B, and C (GRA, GRB, and GRC)) in combining results of multiple agricultural system models. The Granger Ramanathan methods differ in their constraints: GRA employs conventional least squares, GRB requires non-negative weights that total to one, and GRC reduces absolute errors for robustness against outliers. The evaluation was conducted using maize yield and daily ETa simulations for both blind (uncalibrated) and calibrated phases of data from two groups of maize sites (Group A and Group B) across North America. The modeling results from the blind and calibrated phases were combined for all maize models and group maize models. Overall, all MAA performed better than individual crop models for blind and calibration phases. Specifically, the GRB model averaging method provided the closest match to measured values for daily ETa, while GRA was the most accurate for maize yield in most cases across all sites and phases. GRB improved daily ETa estimation over the median by an average of 4 % and 8.5 % in terms of RRMSE, while GRA enhanced maize yield estimation over the median by 7.5 % and 10.9 % for Group A and Group B sites, respectively. Notably, the improvement was greater in the blind phase for both groups of maize sites. An ensemble of group maize models with varied structures performed nearly as well as an ensemble of all maize models in simulating daily ETa and yield for Group A and Group B sites. Based on the results, we recommend GRA for crop yield and GRB for ETa simulations for maize, but both methods require observed yield and ETa data for their application; however, in the absence of observed data, we recommend the SMA method as it performs better than the median. However, the performance of these MAA methods may differ for other crops (e.g., soybean, wheat, canola, potato, alfalfa) or regions, and it should be evaluated in future studies
Transitioning from even-aged rotation forestry to multifunctional forest landscapes? - A Swedish case study of challenges and actions
Get PDFContext: Even-aged forest management is criticised for negative impacts on natural and cultural values, and on value chains dependent on multifunctional forest landscapes. Aim: We identify barriers and bridges supporting the development of multifunctional forest landscapes. Examining five decades of projects aimed at landscape planning in the Swedish Tiveden forest massif, we selected the initiative Collaboration Tiveden for learning through evaluation. Methods: Using document reviews, expert interviews, focus groups and participatory observations, we mapped efforts from the period 1969-2023 encouraging forest multifunctionality. Following the selected collaborative initiative from 2016 to 2023 we collected qualitative and quantitative data. Content analysis using the Institutional Analysis and Development (IAD) framework, and validation using independent data, identified patterns and core driving factors associated to efforts supporting transition from industrial forestry to forest multifunctionality. Results: We identified 11 efforts towards landscape planning. However, in spite of intensified forestry, increased need for protected areas, and pressure from tourists, landscape planning failed to materialise, and alternatives to even-aged forest management was restricted to demonstration sites and not scaled up. Qualitative and quantitative data demonstrate negative effects of intensified forestry on preferred landscape values. Nevertheless, branding using wilderness and narratives of multifunctionality support rural nature-based tourism. However, pressure from tourism on nature increased. Polarisation among actors hampers collaborative learning. Conclusions: Multifunctional forest landscapes require several different forest management systems and landscape planning. This requires learning about multiple forest values, and different forest owners' and users' preferences. While learning through evaluation is important, evidence-based mapping of states and trends of material and immaterial landscape values is not easily accessible, or ignored. Legacies of even-aged forest management are resistant to change
Varroa destructor Biology
Get PDFThe ectoparasitic mite (Varroa destructor) is a parasitic species that has been scrutinized with increasing intensity due to its economic and ecologic impact on European honeybees (Apis mellifera). With the plethora of research being produced it can be difficult to know what is or is not known about varroa mites. Previously, excellent reviews of the varroa have been written that focus on reproduction, disease transmission, and infestation dispersal. The goal of this review however is to gather both historic and modern research on the anatomy, life history, and genetic information of the varroa in detail, but to also point out gaps in the current field of research that should be investigated
‘Amina’, ‘Dioufissa’, and ‘Haby’: Heat tolerant durum wheat cultivars adapted to the Senegal River Basin
Get PDFSenegalese are consumers of pasta, couscous, and other semolina products, which are obtained from durum wheat [Triticum turgidum L. durum (Desf)] grain imports. The Senegal River farming system offers a short dry winter season (harmattan) that is suitable for the cultivation of heat tolerant durum wheat. Hence, delivering super-early high-yielding and heat tolerant durum cultivars was a major goal in this region. ‘Amina’ (Reg. no. CV-1217, PI 708102), ‘Dioufissa’ (Reg. no. CV-1218, PI 708103), and ‘Haby’ (Reg. no. CV-1219, PI 708104) are durum wheat cultivars released in 2020 for cultivation in Senegal and West Africa after 4 years of multi-locations testing. All three are elite lines field-selected at the research farms of Fanaye in Senegal and Kaedi in Mauritania, both of which are located along the Senegal River. These cultivars are released jointly by the Senegalese Institute for Agricultural Research (ISRA), National Center for the Agricultural Research and development (CNRADA) in Mauritania, and the International Center for the Agricultural Research in the Dry Areas (ICARDA) in Morocco because of their adaptation to hot irrigated conditions, early maturity, higher grain yield and good grain quality
INVITED REVIEW: Connecting the dots-Calving difficulty, age at first calving, and enhanced cow production
Get PDFPurpose: We aimed to explore the relationships among calving difficulty (CD), production traits, age at first calving (AFC), and culling in dairy cattle. Sources: Data from 687 US dairy farms, encompassing 1,048,574 CD observations scored from 1 to 5, were analyzed. Scores of CD 5 were adjusted to 4 due to limited interactions with other variables. The focus was on Holstein, Jersey, and dairy cross breeds, and parity was categorized as primiparous or multiparous. Synthesis: The study comprised 4 steps. Step 1 assessed the effect of CD on milk yield, fat, protein, ECM, and peak milk production with fixed effects of CD, parity, calf sex (CS), and breed and random effects of calving year, calving season, and herd. Step 2 analyzed AFC, using linear and quadratic covariates, on the same parameters. Step 3 examined CD as the response variable in the step 2 database. Step 4 used logistic regression to assess risk factors associated with CD and culling reasons. Our results showed the following. Step 1: CD significantly affected milk yield, ECM, fat, protein, and peak milk production, with declines in production traits for CD >2, the least values at CD 4. Step 2: Significant linear and quadratic AFC covariates showed optimal milk performance at 27 to 28 mo. Step 3: CD was influenced by breed, CS, AFC, and interactions, with minimal CD observed at AFC of 23 to 26 mo. Step 4: Greater CD was linked to culling for nondairy purposes. Conclusions and Applications: Calving difficulty affects production traits and is influenced by parity, breed, and CS, but its effect is less significant than expected. The AFC, particularly over 26 mo, has a more pronounced effect on CD. Greater CD levels are associated with increased involuntary culling
Synergistic enhancement of fire performance and carbon footprint reduction in polymer biocomposites through combined use of lignin and biochar
Get PDFBiomass-derived materials are increasingly being incorporated into plastics to create biocomposites that reduce reliance on fossil-based feedstocks and lower carbon footprints. Maximizing the sustainability potential of these bio-based materials requires increasing their content within polymer matrices. However, a significant challenge arises: as bio-based content increases, performance trade-offs often arise. This study addresses this issue by examining the combined use of multiple bio-based components, specifically lignin and biochar, in acrylonitrilebutadiene-styrene (ABS) biocomposites. The bio-based content reached up to 44 wt%, while retaining adequate processability for extrusion and vacuum forming, as demonstrated by producing a miniature roof box sample. With this biocomposite composition, greenhouse gas emissions could be reduced by up to 40 %. Moreover, the fire performance was slightly improved by adding either lignin or biochar alone, while the combination of both fillers improved the fire performance significantly (a peak heat-release rate being half of that of ABS) due to a synergistic barrier-forming effect, limiting the transport of oxygen and fuel to the heat source and reducing heat transfer. The inclusion of both biochar and lignin influenced the mechanical properties of the composite, leading to an increase (33 %) in stiffness but a slight reduction (22 %) in strength. This study suggests that combining biochar and lignin can maximize bio-based content while improving critical performance characteristics, offering a viable pathway for more sustainable plastics
The effect of transglutaminase and ultrasound pre-treatment on the structure and digestibility of pea protein emulsion gels
Get PDFThis study examines the effects of ultrasound and transglutaminase pre-treatments on the structure, rheological properties, and digestibility of emulsion gels made from pea protein isolate and concentrate. Pre-treatments enhanced the elasticity and deformation resistance of gels made from pea protein isolate, with the combination of both treatments yielding the highest storage modulus. In contrast, emulsion gels from pea protein concentrate showed a more complex response, with untreated samples exhibiting higher storage modulus. These differences reflect variations in gelation behaviour between isolates and concentrates, likely due to differences in composition and extraction processes. Protein digestibility, assessed using the o-phthalaldehyde assay, showed significant differences between pre-treatments, but the impact was less pronounced compared to the difference between gels made from isolate and concentrate. Gels made from pea protein isolate had a hydrolysis degree of 77 %, while those from pea protein concentrate had 48 %, with this difference mainly attributed to the higher amounts of starch and fiber in the concentrate, which affected both the gel structure and digestibility. Nuclear magnetic resonance-based metabolomics revealed lower glucose release in transglutaminase-treated gels made from pea protein concentrate and lower glycine release from ultrasound and transglutaminase-treated gels made from pea protein isolate during gastric digestion. However, no significant differences were observed after intestinal digestion, indicating no major limitations in nutrient release due to processing. Overall, these findings highlight the role of protein source and processing methods in influencing rheological properties and nutrient bioavailability in protein systems
Biomimetic Porous Inorganic Materials for Bone Engineering Using a Natural Yam Stalk Template
Get PDFThis study explores biomimicry as a widely recognized and promising approach for developing sustainable structural materials that embody the principles of the circular economy. In this context, the study explores using yam stalks (Dioscorea) as a biotemplate. This natural material, composed of biopolymers such as cellulose and lignin and typically discarded as tuber waste, is characterized by a highly porous morphology with a large volume of interconnected pores. Such a structure can be used as a template to create a bone-mimicking scaffold with potential applications in tissue engineering. Through the sol-gel process and the combination of the Dioscorea biotemplate with tetraethyl orthosilicate (TEOS) or titanium bis(ammonium lactate) dihydroxide (TiBALDH) precursors, silica and titania inorganic porous materials were obtained. After sol-gel deposition of inorganic oxides and removal of the Dioscorea biotemplate by calcination at 700 degrees C, scanning electron microscopy (SEM) revealed a scaffold with a homogeneous network of interconnected macropores evenly distributed throughout the material. At higher magnification, hexagonal patterns (honeycomb-like structures) were observed, highlighting the natural structural optimization that offers advantages in permeability and cellular growth. Micro CT analysis revealed total volumes of 768.61 mm3 for the silica-based porous scaffold and 853.00 mm3 for the titania-based sample, along with macropores of 203-395 and 176-286 mu m per gram, respectively. This pore range is particularly suitable for cell proliferation and nutrient transport in applications like tissue engineering. Moreover, in vitro cytotoxicity and osteogenic assays showed that SD/Ti and SD/Si demonstrated promising osteogenic potential, with good cell viability, ALP activity, and collagen production in both culture media. This pore range is particularly suitable for cell proliferation and nutrient transport in applications like Tissue Engineering. Therefore, this is a promising scaffold alternative, suggesting the use of porous biomimetic materials in tissue engineering, especially synthetic bone. Furthermore, these materials offer multifunctional applications, are environmentally friendly, and are economically viable
Exploring the use of a machine assisted goal and scope in a life cycle studies to understand stakeholder interest and priorities
Get PDFThe Goal and scope are essential phases within a life cycle study as they lay the foundation for the subsequent inventory modelling, impact assessment, and interpretation of results. Stakeholder engagement is critical throughout life cycle studies. Addressing diverse stakeholder interests and priorities have so far relied on stakeholder-expert dialogues, which remain challenging, particularly in projects with numerous stakeholders leading to a broad range of environmental, social, and economic impact categories and subcategories. This study therefore introduces a machine-assisted goal and scope approach to manage large volume of stakeholder responses generated in stakeholder-expert dialogues. It is designed to complement current manual stakeholder engagement approaches with semi-automated computer assisted analysis that identifies stakeholder interests, concerns, and prioritises them. We apply Natural Language Processing (NLP) in the goal and scope phase to preprocess stakeholder response documents collected during a life cycle study within a larger EU project. After preprocessing, unsupervised clustering algorithms were used to determine stakeholders' interests, concerns, and priorities. This innovative use of NLP and clustering was tested on a life cycle study of bioenergy value chains in Namibia (2021-2024). The approach successfully analysed stakeholder responses and identified key impact categories and subcategories on which to focus the assessment. Compared to manual methods, the machine-assisted goal and scope phase improved the level of detail while maintaining the same time frame and resource constraints. The current study serves as a proof of concept and demonstrates how life cycle studies can benefit from a machine-assisted goal and scope approach
Development of a highly sensitive reporter gene cell line for detecting estrogenic activity (the ER Isjaki assay)
Get PDFMonitoring of estrogens in water sources faces significant challenges, as proposed changes in the European Union regulation for environmental protection of water bodies, compromise the ability of conventional analytical methods to detect low concentrations of estrogens. The proposed changes involve the decrease of the environmental quality standards for 17(3-estradiol, estrone and 17 alpha-ethinyl estradiol in surface waters and the obligation to monitor estrogenic substances in water bodies, using effect-based methods. In this study, the optimal experimental conditions for developing a novel and highly sensitive reporter gene assay were established. For this purpose, optimization of transfection plasmid concentration, exposure time and basement membrane matrix effect as well as assessment of assay reproducibility and relative effect potency of natural estrogens and estrogenic substances were conducted. With the optimal experimental conditions set as 5 ng per well in 96-well uncoated plates for plasmid transfection and 24 h exposure to treatments, the assay yielded an average sensitivity, measured as effect level 20 % for 17(3-estradiol, estrone and 17 alpha-ethinyl estradiol of 0.29, 1.36 and 0.02 pM, respectively. The assay showed a reproducibility variation of approximately 20 % and was able to differentiate the relative effect potency between 17 alpha-ethinyl estradiol and 17(3-estradiol with the capacity of detecting 17 alpha-ethinyl estradiol with a high relative effect potency. Moreover, this assay is approximately 10-100 times more sensitive compared to the current state-of-the-art in vitro assays used to measure estrogenicity, indicating that the assay can be used to detect 17(3-estradiol, estrone and 17 alpha-ethinyl estradiol at the low levels needed to meet regulatory standards