Diversity of arbuscular mycorrhizal fungi in the rhizosphere of Plantago coronopus in Northwestern Algerian coast

Mycorrhizal fungi play a major role in the functioning of ecosystems. However, their identification has remained a challenge for scientific research. This study presents the first identification report of species of arbuscular mycorrhizal fungi in the rhizosphere of the halophyte Plantago coronopus L. in Algeria. Samples of rhizospheric soil were collected in spring 2018 at three sites in the Bomo-plage dunes west of Oran, Algeria. The spores were isolated by wet sieving, morphologically identified, and quantified. The mean spore density was 107.94 spores 100 g-1 dry soil, which is high compared to other dune ecosystems. Endomycorrhizal spore morphotypes were involved in the following Genus: Glomus, Septoglomus, Rhizophagus, Diversispora, Funneliformis, Dentiscutata, Claroideoglomus, Scutellospora, and Entrophospora, to the following Family: Glomeraceae, Gigasporaceae, Diversisporaceae, Claroideoglomeraceae, and Acaulosporaceae. The Glomeraceae was the most dominant identified family. The identification of indigenous arbuscular mycorrhizal fungi has been shown to be essential for future programs to restore disturbed dune ecosystems.

MACROAGGREGATION OF A PALEUDALF AFFECTED BY CAVITATION INTENSITY AND MANAGEMENT SYSTEMS WITH COVER PLANTS

Ultrasonic-based techniques allow the prediction of the energy required to break the aggregate and have been more commonly used to measure the stability of aggregates. Although they result in the same applied energy, certain combinations of time and power might correspond to different intensities of cavitation. Consequently, different responses in aggregation indexes can be obtained with different configurations of ultrasound techniques. Thus, this work was carried out to evaluate the effects of cavitation intensity in the distribution of aggregates of a Paleudalf under management systems with cover plants and to compare aggregate stability determination methods (ultrasound versus wet sieving). Aggregate samples of the BS (bare soil), OT (black oat + forage turnips) and OV (black oat + hairy vetch) treatments were exposed to ultrasonic irradiation in different combinations of potency and time: (U1) 74.5 W/4 s; (U2) 49.7 W/6 s; (U3) 74.5 W/10 s and (U4) 49.7 W/15 s. After each sonification, the samples were passed in the same set of sieves used in the standard method of wet sieving -WS (8.00 - 4.76, 4.76 - 2.00, 2.00 - 1.00, 1.00 - 0.25 and < 0.25 mm) and the geometric mean diameter (GMD) and mass-weighted mean diameter (WMD) were calculated. The amplitude of vibration exerted a greater influence on soil breakdown than the total energy applied. Compared to the ultrasound method, in the WS method observed higher percentage of retained aggregates in the size class 8-4.76 mm and, consequently, greater aggregation indexes GMD and WMD.

Pooling size sorted Malaise trap fractions to maximize taxon recovery with metabarcoding

Background Small and rare specimens can remain undetected when metabarcoding is applied on bulk samples with a high specimen size heterogeneity. This is especially critical for Malaise trap samples, where most of the biodiversity is contributed by small taxa with low biomass. The separation of samples in different size fractions for downstream analysis is one possibility to increase detection of small and rare taxa. However, experiments systematically testing different size sorting approaches and subsequent proportional pooling of fractions are lacking, but would provide important information for the optimization of metabarcoding protocols. We set out to find a size sorting strategy for Malaise trap samples that maximizes taxonomic recovery but remains scalable and time efficient. Methods Three Malaise trap samples were sorted into four size classes using dry sieving. Each fraction was homogenized and lysed. The corresponding lysates were pooled to simulate unsorted samples. Pooling was additionally conducted in equal proportions and in four different proportions enriching the small size fraction of samples. DNA from the individual size classes as well as the pooled fractions was extracted and metabarcoded using the FwhF2 and Fol-degen-rev primer set. Additionally, alternative wet sieving strategies were explored. Results The small size fractions harboured the highest diversity and were best represented when pooling in favour of small specimens. Metabarcoding of unsorted samples decreases taxon recovery compared to size sorted samples. A size separation into only two fractions (below 4 mm and above) can double taxon recovery compared to not size sorting. However, increasing the sequencing depth 3- to 4-fold can also increase taxon recovery to levels comparable with size sorting, but remains biased towards biomass rich taxa in the sample. Conclusion We demonstrate that size fractionation of Malaise trap bulk samples can increase taxon recovery. While results show distinct patterns, the lack of statistical support due to the limited number of samples processed is a limitation. Due to increased speed and lower risk of cross-contamination as well as specimen damage we recommend wet sieving and proportional pooling of the lysates in favour of the small size fraction (80–90% volume). However, for large-scale projects with time constraints, increasing sequencing depth is an alternative solution.

Aggregation Index in Representative Soils of the Paraiba State

The stability of soil aggregates is an important physical parameter as it mainly influences the flow of water and air in the soil. In this sence, the research aimed to determine the stability aggregates index in six representative soil classes in the Paraíba State-Brazil at different stages of pedological development. The soil classes analyzed is localized on the Microregions of the Curimataú Occidental (Ferrasol, Planosol, Leptosol, Arenosol) and Brejo Paraibano (Acrisol, Lixisol), on the Paraíba state, Brazil. At depths of 0-5 cm, 5-10 cm and 10-20 cm was collected three undeformed soil samples were collected per mini trench (one per depth), making a total of 15 samples per soil class and 90 total samples. In each soil class was analysed: chemical parameters, granulometrics parameters, stability of agregates, Weighted average diameter via wet sieving (DMPAu) and Weighted average diameter via dry sieving (DMPAs); agregate stability index (IEA). For the conditions that research was developed can conclude that: The IEA values tended to increase with clay contents in all soil classes; Among the less developed soils, the IEA values were better in the Planosol soil, denoting that there is a probable relationship with the low contents of K, Na and Al; In the more developed soils, the high values of Na and Al may have contributed to the lower IEA in the PVd, while the lower values may have contributed to the higher IEA in Ferrasol and Lixisol soils.

Spray-Congealing and Wet-Sieving as Alternative Processes for Engineering of Inhalation Carrier Particles: Comparison of Surface Properties, Blending and In Vitro Performance

Purpose Traditionally, α-lactose monohydrate is the carrier of choice in dry powder inhaler (DPI) formulations. Nonetheless, other sugars, such as D-mannitol, have emerged as potential alternatives. Herein, we explored different particle engineering processes to produce D-mannitol carriers for inhaled delivery. Methods Wet-sieving and spray-congealing were employed as innovative techniques to evaluate the impact of engineering on the particle properties of D-mannitol. To that end, the resulting powders were characterized concerning their solid-state, micromeritics and flowability. Afterwards, the engineered carrier particles were blended with inhalable size beclomethasone dipropionate to form low dose (1 wt%) DPI formulations. The in vitro aerosolization performance was evaluated using the NEXThaler®, a reservoir multi-dose device. Results Wet-sieving generated D-mannitol particles with a narrow particle size distribution and spray-congealing free-flowing spherical particles. The more uniform pumice particles with deep voids and clefts of wet-sieved D-mannitol (Pearl300_WS) were beneficial to drug aerosolization, only when used in combination with a ternary agent (10 wt% of ‘Preblend’). When compared to the starting material, the spray-congealed D-mannitol has shown to be promising in terms of the relative increase of the fine particle fraction of the drug (around 100%), when used without the addition of ternary agents. Conclusions The wet-sieving process and the related aerosolization performance are strongly dependent on the topography and structure of the starting material. Spray-congealing, has shown to be a potential process for generating smooth spherical particles of D-mannitol that enhance the in vitro aerosolization performance in binary blends of the carrier with a low drug dose.

A Novel Index (RI) to Evaluate the Relative Stability of Soils Using Ultrasonic Agitation

As soil stability is a complex phenomenon, various methods and indexes were introduced to assess the strength of soils. Because of the limitations of different stability methods and indexes (including wet sieving-based), we aimed to presents a relative stability index (RI) that was based on the estimated components of the soil overall disruptive characteristic curve (SODC): (1) soil disruption constant (Ki, that is based upon dispersion energy of soils); (2) resulting change in mean weight diameter (ΔMWD). To evaluate the effectiveness and limitations of RI as well as to compare it with classical soil stability indexes of mean weight diameter (MWD) and geometric mean diameter (GMD). Ultrasonic agitation (UA) along with a wet sieving method (followed by dry sieving) was applied against four different soils named on the basis of sample location, Qingling soil (QL), Guanzhong soil (GZ), Ansai soil (AS), and Jingbian soil (JB). To evaluate the relative strength of soils at different applied energies (increase in sonication duration usually resulted in increased input energy and temperature of soil–water suspension), soils were subjected to six sonication durations (0, 30, 60, 120, 210, and 300 s) with a fixed (and exact) initial amplitude and temperature. Output energy was calculated based on the amplitude and temperature of the suspension, vessel, and system. The most abrupt and maximum disruption of soil aggregates was observed at a dispersion energy level of 0–200 J g−1. The MWD value of surface and subsurface ranged between 0.58 to 0.15 mm and 0.37 to 0.17 mm, respectively, while GMD was ranged from 0.14 to 0.33 mm overall. The results for MWD and GMD showed a similar trend. MWD and GMD showed more strong associations with physicochemical characteristics of soil than RI. A non-significant correlation was found between RI and MWD/GMD. Contrary to MWD and GMD, RI was significantly positively correlated with sand content; this finding indicated the influential role of sand in assessing the soil’s relative strength. The results indicated that JB soil possessed the least MWD and GMD but proved to be relatively stable because of having the highest RI value.

Effect of soil organic carbon loss on the stability and structure of microaggregates: First insights from an organic carbon depletion field trial in a loess soil

&lt;p&gt;Soil microaggregates are considered to play an important role in soil functioning and soil organic carbon (SOC) is of great importance for the formation and stabilization of these aggregates. The loss of SOC can occur, for example, after a change in land use and may lead to a decreased aggregate stability, which makes soils vulnerable to various threats, such as erosion or compaction. It is therefore important to shed light on the effect of SOC loss on aggregate stability in order to better understand and preserve the functioning of healthy soils.&lt;/p&gt;&lt;p&gt;We sampled two adjacent plots from a loess soil in Selhausen (Germany) and measured aggregate stability and architecture of soil microaggregates. One plot was kept free from vegetation by the application of herbicides and by tillage (to a depth of 5 cm) from 2005 on (organic matter depletion, OMD), while the other plot was used for agriculture using conventional tillage (control). Over the course of 14 years, the SOC concentration in the bulk soil has been reduced from 12.2 to 10.1 g SOC kg-1 soil. It was, however, unclear whether a loss of SOC had also taken place in microaggregates (since they are known to have very long turnover times). We took 10 undisturbed soil cores from two depths of each plot (Ap and Bt horizons).&lt;/p&gt;&lt;p&gt;The stability of aggregates against hydraulic and mechanical stresses was tested using wet sieving&amp;#160; (mesh sizes of 0.25 to 8 mm) and a crushing test in a load frame adapted to the microaggregate scale. For the latter test, microaggregates were isolated from the bulk soil using a newly developed dry crushing approach. To shed light on the effect of a decreased SOC content on microaggregate structure, we scanned several microaggregates with a computed tomography scanner at sub-micron resolution and analysed the features of their pore systems. SOC losses had also occurred in large&amp;#160; microaggregates (250-53 &amp;#181;m) in the Ap horizon: SOC contents in this fraction were 16.3 g SOC kg&amp;#8315;&amp;#185; (control) and 12.8 g SOC kg&amp;#8315;&amp;#185; (OMD). While wet sieving indicated a lower stability of macroaggregates from the Ap horizon in the OMD plot (geometric mean diameter: 1.54 mm (control) vs 0.43 mm (OMD)), an effect on the tensile strength of large microaggregates could not be found. Total porosity and pore connectivity, derived from Euler characteristic, as well as several pore skeleton traits (number of branches, junctions, etc.) were lower in aggregates from the OMD treatment. However, the difference was also present or even stronger in the Bt horizon than in the Ap horizon, so the supposed treatment effect might have been due to other effects like spatial heterogeneity of texture. Thus, the observed SOC losses may not have been large enough to substantially influence struture or stability of large microaggregates.&lt;/p&gt;

Aggregate stability of cultivated vineyard soils with high rock fragment content in the Mosel area, Germany

&lt;p&gt;Within the European project Diverfarming (Horizon 2020, no 728003), which investigates crop diversification and low-input farming across Europe, we study the aggregate stability variability of soils with high rock fragment content on steep sloping vineyards in the upper Saar valley of the Mosel area (Wawern, Rhineland-Palatinate, Germany).&lt;/p&gt;&lt;p&gt;In the framework of the case study researched by Trier University and their partners, aromatic herbs (Oregano and Thyme) are planted in rows underneath the grapevines to minimize soil erosion, suppress unwanted weeds and to be harvested for further use. Additionally, this cultivation affects different soil characteristics such as aggregate stability.&lt;/p&gt;&lt;p&gt;We analyse the aggregate stability using and comparing three different methods:&lt;/p&gt;&lt;ul&gt;&lt;li&gt;wet sieving which is executed in two different ways &amp;#8211; slaked and rewetted treatment,&lt;/li&gt; &lt;li&gt;percolation method and&lt;/li&gt; &lt;li&gt;single drop technique.&lt;/li&gt; &lt;/ul&gt;&lt;p&gt;Aim of the study is to understand the effect of soil treatments underneath the grapevines, and to identify the method(s) being able to quantify the differences best.&lt;/p&gt;&lt;p&gt;Regarding the different methods, first results indicate that the quantified aggregate stabilities of each method are comparable. With this, we could identify differences between uncultivated rows (control areas), and the rows intercropped with aromatic herbs. In the latter ones, the aggregate stability underneath the grapevines is affected positively. Furthermore, there is a clear difference between slaked and rewetted treatment within the wet sieving method, where less stable aggregates are isolated.&lt;/p&gt;&lt;p&gt;The results indicate that the accomplished management (vine intercropped with Oregano and Thyme) improves the aggregate stability and therefore it improves the soil quality in general.&lt;/p&gt;

Étude de l’habitat et des exigences écologiques du Vertigo geyeri Lindholm, 1925 dans le Massif jurassien

Le Vertigo septentrional (Vertigo geyeri Lindholm, 1925) est un Mollusque millimétrique inscrit à l’annexe II de la Directive Habitat-Faune-Flore. La Franche-Comté, qui constitue la limite occidentale de son aire de répartition continentale, abrite le principal bastion de cette espèce au niveau national, ce qui lui confère des responsabilités particulièrement élevées pour le maintien de cette espèce en France. Dans le cadre d’un stage de deuxième année de master, une étude a été conduite afin de caractériser l’habitat et les exigences écologiques du Vertigo geyeri en Franche-Comté, par l’analyse des cortèges botaniques et malacologiques associés, ainsi que les composantes environnementales clés pour cette espèce. Ainsi, 32 sites ont été échantillonnés en 2016 et 2018 dans le Massif jurassien, sur lesquels un relevé malacologique utilisant la méthode du wet sieving a été effectué, en complément d’un relevé botanique phytosociologique comprenant les trachéophytes et les bryophytes. La connaissance de la distribution du Vertigo geyeri dans le Massif jurassien a pu être améliorée, avec à ce jour 62 stations connues en Franche-Comté. Suite à cette étude, nous pouvons estimer que Vertigo geyeri est associé aux tourbières basses neutroclines minétrophes à trèfle d’eau et amblystégiacées (Caricenion lasiocarpae), avec comme espèces structurantes Menyanthes trifoliata L. et Scorpidium cossonii Hedenä. Ces zones humides sont généralement ouvertes, situées au sein de réseaux hydrologiques importants avec une végétation éparse et un sol constamment humide et limité en nutriments.

Processing of Iraqi Attapulgite For Using as Drilling Muds: A Comparison Study

Clay mineral processing is in charge on quality, quantity and functional properties of final produced clay. In this work, Iraqi attapulgite (Palygorskite) clay was processed with dry sieving, dispersing agent and wet sieving processes to make it suitable in oil and gas wells drilling fluids preparation. Yield of clay (quality) and yield of process (quantity) were taken as preferring criteria in choosing the proper process of Iraqi attapulgite clay preparation. XRD and FESEM tests were used for mineralogical and morphological identification respectively. OFITE viscometer was used to measure the rheological properties of the drilling fluids prepared with the produced attapulgite from the investigated processes. The results of this work showed that dry sieving process was failed in attapulgite separation. Moreover, dry grinding was a destructive process of the attapulgite crystalline structure which reduced the rheological properties up to 80%. The results showed that the dispersing agents process produces attapulgite clay with higher quality (101.94 and 89.87 barrle/ton) with fresh and salt water respectively and at low quantity of about 7%. While wet sieving process produces attapulgite clay with quality equals to (94.21 and 79.93barrel/ton) with fresh and salt water respectively and quantity reaching 40%. It follows that wet sieving was the recommended process in preparing Iraqi attapulgite to be suitable for oil and gas wells drilling fluid