Biotic Yield Losses in the Southern Amazon, Brazil: Making Use of Smartphone-Assisted Plant Disease Diagnosis Data

Pathogens and animal pests (P&A) are a major threat to global food security as they directly affect the quantity and quality of food. The Southern Amazon, Brazil's largest domestic region for soybean, maize and cotton production, is particularly vulnerable to the outbreak of P&A due to its (sub)tropical climate and intensive farming systems. However, little is known about the spatial distribution of P&A and the related yield losses. Machine learning approaches for the automated recognition of plant diseases can help to overcome this research gap. The main objectives of this study are to (1) evaluate the performance of Convolutional Neural Networks (ConvNets) in classifying P&A, (2) map the spatial distribution of P&A in the Southern Amazon, and (3) quantify perceived yield and economic losses for the main soybean and maize P&A. The objectives were addressed by making use of data collected with the smartphone application Plantix. The core of the app's functioning is the automated recognition of plant diseases via ConvNets. Data on expected yield losses were gathered through a short survey included in an "expert" version of the application, which was distributed among agronomists. Between 2016 and 2020, Plantix users collected approximately 78,000 georeferenced P&A images in the Southern Amazon. The study results indicate a high performance of the trained ConvNets in classifying 420 different crop-disease combinations. Spatial distribution maps and expert-based yield loss estimates indicate that maize rust, bacterial stalk rot and the fall armyworm are among the most severe maize P&A, whereas soybean is mainly affected by P&A like anthracnose, downy mildew, frogeye leaf spot, stink bugs and brown spot. Perceived soybean and maize yield losses amount to 12 and 16%, respectively, resulting in annual yield losses of approximately 3.75 million tonnes for each crop and economic losses of US$2 billion for both crops together. The high level of accuracy of the trained ConvNets, when paired with widespread use from following a citizen-science approach, results in a data source that will shed new light on yield loss estimates, e.g., for the analysis of yield gaps and the development of measures to minimise them.

A novel process concept for the three step Boscalid® synthesis

A three phase microemulsion system was applied for a more sustainable synthesis of the fungicide Boscalid®.

Unexpected efficiency boosting in CO2-microemulsions: a cyclohexane depletion zone near the fluorinated surfactants evidenced by a systematic SANS contrast variation study

Concentration gradient of cyclohexane in a CO₂/cyclohexane swollen micelle stabilized by fluorinated surfactants revealed by the GIFT analysis of a SANS contrast variation.

Microcellular foams made from gliadin

We have generated closed-cell microcellular foams from gliadin, an abundantly available wheat storage protein. The extraction procedure of gliadin from wheat gluten, which involves only the natural solvents water and ethanol, respectively, is described with emphasis on the precipitation step of gliadin which results in a fine dispersion of mostly spherical, submicron gliadin particles composed of myriad of protein molecules. A dense packing of these particles was hydrated and subjected to an atmosphere of carbon dioxide or nitrogen in a high-pressure cell at 250 bar. Subsequent heating to temperatures close to but still below 100 °C followed by sudden expansion and simultaneous cooling resulted in closed-cell microcellular foam. The spherical gliadin templates along with the resulting foam have been analyzed by scanning electron microscope (SEM) pictures. The size distribution of the primary particles shows diameters peaked around 0.54 μm, and the final foam cell size peaks around 1.2 μm, at a porosity of about 80 %. These are the smallest foam cell sizes ever reported for gliadin. Interestingly, the cell walls of these microcellular foams are remarkably thin with thicknesses in the lower nanometer range, thus nourishing the hope to be able to reach gliadin nanofoam.

A comprehensive, time-resolved SANS investigation of temperature-change-induced sponge-to-lamellar and lamellar-to-sponge phase transformations in comparison with 2H -NMR results

Time-resolved small-angle neutron scattering (TR-SANS) was employed to observe temperature-induced phase transitions from the sponge (L (3) to the lamellar ( L (alpha) phase, and vice versa, in the water-oil (n -decane)-non-ionic surfactant ( C(12)E(5) system using both bulk and film contrast. Samples of different bilayer volume fractions phi and solvent viscosities eta were investigated applying various amplitudes of temperature jump DeltaT . The findings of a previous (2)H -NMR study could be confirmed, where the lamellar phase formation was determined to occur through a nucleation and growth process, while it was concluded that the L (3) -phase develops in a mechanistically different and more rapid manner involving uncorrelated passage formation. Likewise, the kinetic trends of the nucleation and growth transition (decreased transition time with increase of phi and DeltaT were witnessed once again. Additionally, NMR and SANS data that demonstrate a strong dependency of that process on solvent viscosity eta are presented. Contrariwise, it is made evident via both SANS and NMR results that the L (alpha) -to-L (3) transition time is independent (within experimental sensitivity) of the varied parameters (phi , DeltaT , eta . Unusual scattering evolution in one experiment, originating from a highly ordered lamellar phase, intriguingly hints that a major rate determining factor is the disruption of long-range order. Furthermore, the bulk contrast investigations give insight into structure peak shifts/development during the transitions, while the film contrast experiments prove the bilayer thickness to be constant throughout the phase transitions and show that there is no evidence for a change in the short-range order of the bilayer structure. The latter was considered possible, due to the different topology of the L (3) and L (alpha) phases. Lastly, an unexpected yet consistent appearance of anisotropic scattering is detected in the L (3) -to- L (alpha) transitions.

The EACN scale for oil classification revisited thanks to fish diagrams

The phase behavior of C(10)E(4)-oil-water systems at constant o/w ratio and variable temperature (fish diagram) has been investigated for several homologous oil families. The temperature T( *) and surfactant concentration C( *) at the critical point were determined for 10 n-alkanes varying from C(6) to C(28) as well as for a series of alkylcyclohexanes and alkylbenzenes. On the basis of T( *), equivalent alkane carbon numbers (EACN) were assigned to nonlinear alkanes, alkylbenzenes, and alkylcyclohexanes. The consistency of the method was shown by corroborating that the EACN values of oils previously investigated with other C(i)E(j) (dibutyl ether, squalane, isopropyl myristate, and dodecylbenzene) are the same when determined with C(10)E(4). The fact that two oils of different nature but with the same EACN (i.e., the same T( *)) do not exhibit the same C( *) is discussed in terms of monomeric solubility of the surfactant in the oil (CMC(oil)).

Triacylglycerol microemulsions stabilized by alkyl ethoxylate surfactants--a basic study. Phase behavior, interfacial tension and microstructure

As triacylglycerols are the main components of natural fats and oils their solubilization in the form of emulsions or microemulsions was of great interest within the last years. However, systematic studies of their properties along the classical lines of complex fluids science are still missing. In the present paper we focus on the phase behavior, the interfacial tension and the microstructure of systems of type H(2)O/NaCl-triacylglycerol-alkylpolyglycolether (C(i)E(j)). The interfacial tension between water and oil sigma(ab) is high in a microemulsion system containing triolein. Thus, one needs high surfactant mass fractions to formulate a single-phase microemulsion. We show that this is not only true for triolein, but also for saturated long-chained triacylglycerols. The determination of the amphiphilicity factor f(a) and the calculation of the bending rigidities of the amphiphilic film confirm that despite the fact that high surfactant mass fractions and high temperatures are needed to solubilize triolein in a system of type H(2)O/NaCl-triacylglycerol-alkylpolyglycolether (C(i)E(j)), this is still a microemulsion in the narrower sense.

Homogeneous nucleation of n-nonane and n-propanol mixtures: A comparison of classical nucleation theory and experiments

The homogeneous nucleation rates for n-nonane-n-propanol vapor mixtures have been calculated as a function of vapor-phase activities at 230 K using the classical nucleation theory (CNT) with both rigorous and approximate kinetic prefactors and compared to previously reported experimental data. The predicted nucleation rates resemble qualitatively the experimental results for low n-nonane gas phase activity. On the high nonane activity side the theoretical nucleation rates are about three orders of magnitude lower than the experimental data when using the CNT with the approximate kinetics. The accurate kinetics improves the situation by reducing the difference between theory and experiments to two orders of magnitude. Besides the nucleation rate comparison and the experimental and predicted onset activities, the critical cluster composition is presented. The total number of molecules is approximated by CNT with reasonable accuracy. Overall, the classical nucleation theory with rigorous kinetic prefactor seems to perform better. The thermodynamic parameters needed to calculate the nucleation rates are revised extensively. Up-to-date estimates of liquid phase activities using universal functional activity coefficient Dortmund method are presented together with the experimental values of surface tensions obtained in the present study.

Freeze fracture direct imaging: a new freeze fracture method for specimen preparation in cryo-transmission electron microscopy

In this paper, we present a new freeze fracture method for specimen preparation for transmission electron microscopy frozen samples. We call it freeze fracture direct imaging (FFDI) because it is a hybrid of conventional freeze fracture electron microscopy (FFEM) and cryo-transmission electron microscopy (cryo-TEM), combining elements of the fracture technique with direct imaging. Like in FFEM, the sandwich method is used to prepare the sample in a protected fashion. However, after the sample is vitrified and fractured, it is not shadowed but directly imaged. The new technique avoids some experimental artifacts produced by the blotting procedure in conventional cryo-TEM. It relies, though, on occasional fractures transparent to the electrons. The advantageous features are demonstrated by a comparison between conventional cryo-TEM and FFDI micrographs of vesicular solutions. The second outstanding advantage over conventional cryo-TEM is the fact that it is now possible for the very first time to directly image oil-rich mixtures films which normally would dissolve in the cryo-medium ethane. Micrographs of pure oil and of oil-rich microemulsions clearly prove the reliability of the FFDI technique as well as its enormous potential.

Temperature dependence of the thermodynamics and kinetics of micellar solutions

We predict theoretically the thermodynamics and relaxation kinetics of solutions of cylindrical branched micelles. Using a recently developed theory in combination with the experimental data, we explain the unusual, inverted temperature dependence of the phase separation observed in wormlike micelles and dilute microemulsions. We extend the model to treat the temperature dependence of the relaxation kinetics and explain the observations.

Physical properties of detergent-based aqueous two-phase systems

The physical behavior of the binary phase systems of the non-ionic polyoxyethylene detergent Agrimul NRE 1205 and water was investigated. This technical detergent can be used for the large-scale recovery of biomolecules in detergent based aqueous two-phase systems. The phase diagram was determined. It shows significant and unexpected differences to highly purified detergents. Very similar to neat detergents the phase diagram can be influenced by auxiliary chemicals thus shifting the entire phase diagram in general to lower temperatures. This was demonstrated by lowering the cloud-point by various additions. The concentration factor, as an important parameter of a first capture step in purification was investigated and modeled. Auxiliary chemicals, temperature change and change in detergent concentration also influence the viscosity and density of the phases. These experimental data are shown. They can help to explain the separation behavior of proteins. In large-scale separations aqueous two-phase systems are separated using disc-stack centrifuges. It is demonstrated that this is not a feasible method for detergent-based aqueous two-phase extraction and the physical reason is presented.