From point to field scale results: upscaling pointwise analysis of glyphosate vertical mobility through the spatial knowledge of the soil infiltration capacity

<p>In the two-year period 2018-2020 the Centre of Hydrology ‘Dino Tonini’ of the University of Padova developed the UNI-Impresa research project SWAT (Subsurface Water quality and Agricultural pracTices monitoring) to study the interactions between agricultural practices, mainly those involved in the production of Prosecco, and the wellhead protection areas in the province of Treviso (Italy). Specific experimental activities, integrated by a modelling analysis of the collected data, were developed to understand the processes affecting the vertical evolution of a glyphosate-based pesticide in the unsaturated soil up to a depth of 0.70 m BGL. The pesticide, along with a non-reactive tracer (potassium bromide), was applied in November 2018 in two experimental sites (Settolo-Valdobbiadene and Colnù-Conegliano) organized nearby well-fields supplying public water systems. Its evolution subjected only to the natural hydrological forcing compared to the infiltration dynamics of the tracer was locally monitored by collecting and analyzing soil and water samples along six months. Both the application and the monitoring activities were carried out in each experimental site on two 25 m<sup>2</sup> parcels located at reciprocal distances of 30 m (Settolo) and 115 m (Colnù), obtaining a detailed information about the glyphosate vertical evolution. Each point-wise analysis highlights a strong tendency of the pesticide and its principal metabolite (AMPA) to be adsorbed to the soil matrix rather than to be dissolved in the infiltrated rainwater and carried toward the deeper layers of the soil. However, high concentrations of the pesticide spotted at the depth of -0.70 m suggest that preferential pathways and more intense precipitation events enhance the downward movement of the glyphosate, either dissolved in water or adsorbed to microscopic particles. Differences in the pesticide spatio-temporal evolution were observed between parcels belonging to the same site.  Despite the decay analyzed during the experiments is related to both the chemical-physical properties of the soil, the potential movement is dominated by the heterogeneity of the hydraulic properties of soil. Hence, the evaluation of the infiltration capacity was considered a low-cost proper method to extend the analysis to the field scale (~10<sup>2</sup> m characteristic length). In the experimental site of Colnù, the spatial variability of the soil infiltration capacity (mm/min) and dynamics has been assessed developing a series of tests using the double ring infiltrometer in 17 different positions within an area of 1.75 ha. The investigated area extends over two contiguous vineyards inside the wellhead protection area. Two tests positions correspond to the site parcels while the remaining were spatially distributed maintaining reciprocal distances ranging between 15 and 50 meters. The measured soil infiltration capacity shows a large spatial variability, up to two orders of magnitude. The geostatistical interpolation (kriging) of the achieved data gives a quantitative estimation of the soil vulnerability at the field scale based on the potentially infiltrating pesticide.</p>

The three-dimensional life cycles of potential vorticity cutoffs

<p>The aim of this study is to explore the nature of potential vorticity (PV) cutoff life cycles. While climatological frequencies of such upper-level cyclonic vortices are well known, their life cycle and in particular their three-dimensional evolution is poorly understood. To address this gap, a novel method is introduced that uses isentropic air parcel trajectories to track PV cutoffs as three-dimensional objects. With this method, we can distinguish the two fundamentally different PV cutoff lysis scenarios on isentropic surfaces: complete diabatic decay vs. reabsorption by the stratospheric reservoir.</p><p>This method is applied to the ERA-interim dataset (1979-2018) and the first global climatology of PV cutoffs is presented that is independent of the selection of a vertical level and identifies and tracks PV cutoffs as three-dimensional features. More than 140’000 PV cutoff life cycles are identified and analyzed. The climatology confirms known frequency maxima of PV cutoffs and identifies additional bands in subtropical areas in the summer hemispheres and a circumpolar band around Antarctica. The first climatological analysis of diabatic decay and reabsorption shows that both scenarios occur equally frequently – in contrast to the prevailing opinion that diabatic decay dominates.</p><p>Further, PV cutoffs are classified according to their position relative to jet streams [equatorward (type I), between two jets (type II), and poleward (type III)]. A composite analysis of PV cutoff genesis shows distinct dynamical scenarios for the three types. Type I forms due to anticyclonic Rossby wave breaking above subtropical surface anticyclones and hardly results in precipitation. Type II results from anticyclonic Rossby wave breaking downstream of the storm tracks and is frequently accompanied by surface cyclogenesis and substantial precipitation. Type III cutoffs preferentially form due to wave breaking within mature extratropical cyclones in the storm track regions. We show that important track characteristics (speed, travel distance, frequency of decay and reabsorption, vertical evolution) differ between the categories, while lifetime is similar in all categories. </p><p>Finally, twelve PV cutoff genesis regions in DJF and JJA are selected to study the regional characteristics of PV cutoff life cycles. We find that many characteristics of these PV cutoffs reflect the preferred regional occurrence of the different life cycle types. However, a few regions are characterized by substantially longer (e.g. central subtropical North Atlantic in summer) or shorter (Mediterranean in summer) lifetimes than most other regions. Furthermore, a remarkable variability in the vertical evolution of PV cutoffs is found. While in some regions, PV cutoffs rapidly disappear at lower levels by diabatic decay, they can grow downward in other regions. We also show that in many regions PV cutoffs can be involved in surface cyclogenesis even after their formation.</p><p>This study is an important step towards quantifying fundamental dynamical characteristics and the surface impacts of PV cutoffs. The proposed classification according to the jet-relative position provides a useful way to improve the conceptual understanding of PV cutoff life cycles. However, these life cycles can be substantially modified by specific regional conditions.</p>

Macro- and microfeatures of Early Cambrian dolomitic microbialites from Tarim Basin, China

The fabrics of microbialites preserved in limestones are generally better than in dolostones. What are the fabrics of the microbialites preserved in heavily dolomitized dolostones? This paper presents an example of a strongly dolomitized Cambrian microbialite profile. The Xiaoerblak Formation (Cambrian Series 2 Stage 3 and lower Stage 4) of the Sugaitblak section in Aksu, Xinjiang Uygur Autonomous Region, China is mainly composed of microbial dolostones. Due to strong alteration by diagenesis, their features, formation and environments have not been fully understood. Here, based on detailed observation on outcrops and thin sections, we show that this formation comprises four kinds of microbialites: laminite, thrombolite, thrombolitic laminite, and Renalcis framestone, in five intervals (Interval I to Interval V). We identified three main types of microbialite fabrics, i.e., clotted fabric, laminated fabric and skeletal fabric, and established a high-resolution vertical evolution sequence of the microbialites. The clotted fabric and the laminated fabric were further divided into subtypes. We found that the original fabrics were mainly affected by dolomitization, recrystallization and dissolution, and the alteration degree of the microbialite fabric is stronger in the lower part of this formation. The laminated fabric has the strongest resistance to diagenesis, followed by the clotted fabric. Based on studies of different rock types and sedimentary structures, we concluded that the sedimentary environment of Xiaoerblak Formation consists of three settings: a) Intervals I to III formed in restricted tidal flat environments, b) Interval IV and the lower part of Interval V in restricted deep subtidal environments, and c) upper part of Interval V in shallowing-up open subtidal environments.

Generalized Regularity and the Symmetry of Branches of ''Botanological'' Networks

We derive the generalized regularity of convex quadrilaterals in R^2, which gives a new evolutionary class of convex quadrilaterals that we call generalized regular quadrilaterals in R^2. The property of generalized regularity states that the Simpson line defined by the two Steiner points passes through the corresponding Fermat-Torricelli point of the same convex quadrilateral. We prove that a class of generalized regular convex quadrilaterals consists of convex quadrilaterals, such that their two opposite sides are parallel. We solve the problem of vertical evolution of a ''botanological'' thumb (a two way communication weighted network) w.r to a boundary rectangle in R^2 having two roots,two branches and without having a main branch, by applying the property of generalized regularity of weighted rectangles. We show that the two branches have equal weights and the two roots have equal weights, if the thumb inherits a symmetry w.r to the midperpendicular line of the two opposite sides of the rectangle, which is perpendicular to the ground (equal branches and equal roots). The geometric, rotational and dynamic plasticity of weighted networks for boundary generalized regular tetrahedra and weighted regular tetrahedra lead to the creation of ''botanological'' thumbs and ''botanological'' networks (with a main branch) having symmetrical branches

Finding orthologous gene blocks in bacteria: the computational hardness of the problem and novel methods to address it

Motivation The evolution of complexity is one of the most fascinating and challenging problems in modern biology, and tracing the evolution of complex traits is an open problem. In bacteria, operons and gene blocks provide a model of tractable evolutionary complexity at the genomic level. Gene blocks are structures of co-located genes with related functions, and operons are gene blocks whose genes are co-transcribed on a single mRNA molecule. The genes in operons and gene blocks typically work together in the same system or molecular complex. Previously, we proposed a method that explains the evolution of orthologous gene blocks (orthoblocks) as a combination of a small set of events that take place in vertical evolution from common ancestors. A heuristic method was proposed to solve this problem. However, no study was done to identify the complexity of the problem. Results Here, we establish that finding the homologous gene block problem is NP-hard and APX-hard. We have developed a greedy algorithm that runs in polynomial time and guarantees an O(ln⁡n) approximation. In addition, we formalize our problem as an integer linear program problem and solve it using the PuLP package and the standard CPLEX algorithm. Our exploration of several candidate operons reveals that our new method provides more optimal results than the results from the heuristic approach, and is significantly faster. Availability and implementation The software and data accompanying this paper are available under the GPLv3 and CC0 license respectively on: https://github.com/nguyenngochuy91/Relevant-Operon.