Experimental Protocol Research Articles

High-throughput DNA extraction strategy for fecal microbiome studies.

Next-generation sequencing (NGS) is a widely used method for determining the composition of the gut microbiota. Due to the differences in the gut microbiota composition between individuals, microbiome studies have expanded into large population studies to maximize detection of small effects on microbe-host interactions. Thus, the demand for a rapid and reliable microbial profiling is continuously increasing, making the optimization of high-throughput 96-format DNA extraction integral for NGS-based downstream applications. However, experimental protocols are prone to bias and errors from sample collection and storage, to DNA extraction, primer selection and sequencing, and bioinformatics analyses. Methodological bias can contribute to differences in microbiome profiles, causing variability across studies and laboratories using different protocols. To improve consistency and confidence of the measurements, the standardization of microbiome analysis methods has been recognized in many fields.

Boswellic Acid and Betulinic Acid Pre-treatments Can Prevent the Nephrotoxicity Caused by Cyclophosphamide Induction.

Cyclophosphamide (CYP) is a chemotherapeutic drug used to treat various cancers. However, its clinical use is limited due to severe organ damage, particularly to the kidneys. While several phytochemicals have been identified as potential therapeutic targets for CYP nephrotoxicity, the nephroprotective effects of boswellic acid (BOSW) and betulinic acid (BET) have not yet been investigated. Our study used 42 rats divided into six equal groups. The study included six groups: control, CYP (200 mg/kg), CYP+BOSW20 (20mg/kg), CYP+BOSW40 (40 mg/kg), CYP+BET20 (20 mg/kg), and CYP+BET40 (40 mg/kg). The pre-treatments with BOSW and BET lasted for 14 days, while the application of cyclophosphamide was performed intraperitoneally only on the 4th day of the study. After the experimental protocol, the animals were sacrificed, and their kidney tissues were isolated. Renal function parameters, histological examination, oxidative stress, and inflammation parameters were assessed both biochemically and at the molecular level in kidney tissue. The results showed that oxidative stress and inflammatory response were increased in the kidney tissue of rats treated with CYP, leading to impaired renal histology and function parameters (p < 0.05). Oral administration of both doses of BET and especially high doses of BOSW improved biochemical, oxidative, and inflammatory parameters significantly (p < 0.05). Histological studies also showed the restoration of normal kidney tissue architecture. BOSW and BET have promising biological activity against CYP-induced nephrotoxicity by attenuating inflammation and oxidative stress and enhancing antioxidant status.

Energetics of the Transmembrane Peptide Sorting by Hydrophobic Mismatch.

Hydrophobic mismatch between a lipid membrane and embedded transmembrane peptides or proteins plays a role in their lateral localization and function. Earlier studies have resolved numerous mechanisms through which the peptides and membrane proteins adapt to mismatch, yet the energetics of lateral sorting due to hydrophobic mismatch have remained elusive due to the lack of suitable computational or experimental protocols. Here, we pioneer a molecular dynamics simulation approach to study the sorting of peptides along a membrane thickness gradient. Peptides of different lengths tilt and diffuse along the membrane to eliminate mismatch with a rate directly proportional to the magnitude of mismatch. We extract the 2-dimensional free energy profiles as a function of local thickness and peptide orientation, revealing the relative contributions of sorting and tilting, and suggesting their thermally accessible regimes. Our approach can readily be applied to study other membrane systems of biological interest where hydrophobic mismatch, or membrane thickness in general, plays a role.

A novel methodology to assess optical profilometer stability to discriminate surface roughness

A new method is proposed to investigate the measurement variation of instruments and their ability to discriminate two TA6V surfaces obtained by grinding with SiC grit papers (80 and 120). Three optical measurement technologies included into a single apparatus, namely Confocal Microscopy (CM), Focus Variation (FV) and Coherence Scanning Interferometry (CSI), were used to measure both ground surfaces according to a specific experimental protocol (MorphoMeca Monitoring) based on measurement iterations and repetitions. From the measurements, four indices were built from the Sa roughness parameter to assess the Quality (ratio of the topographical variability over the measurement noise), the Drift (related to surface fluctuations) and the Stability (estimation of the temporal drift using a second order autoregressive model) of the three measurement technologies (modes), as well as their Relevance (computed from an analysis of variance) to discriminate ground surfaces with close roughness. For these investigated surfaces, it was especially highlighted that the Quality Index is four times higher for the CSI mode than for the FV and CM modes. All the used measurement modes experienced small drifting (Drift Index) during the measurements. The CSI mode was slightly more sensitive to drift than the FV and CM modes. The Stability Index indicated that there was no memory effect between two acquisitions for each measurement mode, i.e., the temporal drift did not depend on the measurement mode. Moreover, the three measurement modes are able to discriminate the two ground surfaces with the same accuracy through the Sa parameter. However, the Sa values may vary depending on the measurement modes, and it was finally shown that the Sa parameter is minimized by 0.03 μm for the FV mode compared with the CSI mode, due to its smoothing effect.

Temporal dynamics of fecal microbiota community succession in broiler chickens, calves, and piglets under aerobic exposure.

Researchers have extensively studied the effect of oxygen on the growth and survival of bacteria. However, the impact of oxygen on bacterial community structure, particularly its ability to select for taxa within the context of a complex microbial community, is still unclear. In a 21-day microcosm experiment, we investigated the effect of aerobic exposure on the fecal community structure and succession pattern in broiler, calf, and piglet feces (n = 10 for each feces type). Bacterial diversity decreased and community structure changed rapidly in the broiler microbiome (P < 0.001), while the fecal community of calves and piglets, which have higher initial diversity, was stable after initial exposure but decreased in diversity after 3 days (P < 0.001). The response to aerobic exposure was host animal specific, but in all three animals, the change in community structure was driven by a decrease in anaerobic species, primarily belonging to Firmicutes and Bacteroidetes (except in broilers where Bacteroidetes increased), along with an increase in aerobic species belonging to Proteobacteria and Actinobacteria. Using random forest regression, we identified microbial features that predict aerobic exposure. In all three animals, host-beneficial Prevotella-related ASVs decreased after exposure, while ASVs belonging to Acinetobacter, Corynbacterium, and Tissierella were increased. The decrease of Prevotella was rapid in broilers but delayed in calves and piglets. Knowing when these pathobionts increase in abundance after aerobic exposure could inform farm sanitation practices and could be important in designing animal experiments that modulate the microbiome.IMPORTANCEThe fecal microbial community is contained within a dynamic ecosystem of interacting microbes that varies in biotic and abiotic components across different animal species. Although oxygen affects bacterial growth, its specific impact on the structure of complex communities, such as those found in feces, and how these effects vary between different animal species are poorly understood. In this study, we demonstrate that the effect of aerobic exposure on the fecal microbiota was host-animal-specific, primarily driven by a decrease in Firmicutes and Bacteroidetes, but accompanied by an increase in Actinobacteria, Proteobacteria, and other pathobionts. Interestingly, we observed that more complex communities from pig and cattle exhibited initial resilience, while a less diverse community from broilers displayed a rapid response to aerobic exposure. Our findings offer insights that can inform farm sanitation practices, as well as experimental design, sample collection, and processing protocols for microbiome studies across various animal species.

Deterministic generation of highly squeezed GKP states in ultracold atoms

We demonstrate a method for encoding Gottesman–Kitaev–Preskill (GKP) error-correcting qubits with single ultracold atoms trapped in individual sites of a deep optical lattice. Using quantum optimal control protocols, we demonstrate the generation of GKP qubit states with 10 dB squeezing, which is the current minimum allowable squeezing level for use in surface code error correction. States are encoded in the vibrational levels of the individual lattice sites and generated via phase modulation of the lattice potential. Finally, we provide a feasible experimental protocol for the realization of these states. Our protocol opens up possibilities for generating large arrays of atomic GKP states for continuous-variable quantum information.

Integrated approach to generate artificial samples with low tumor fraction for somatic variant calling benchmarking

BackgroundHigh-throughput sequencing (HTS) has become the gold standard approach for variant analysis in cancer research. However, somatic variants may occur at low fractions due to contamination from normal cells or tumor heterogeneity; this poses a significant challenge for standard HTS analysis pipelines. The problem is exacerbated in scenarios with minimal tumor DNA, such as circulating tumor DNA in plasma. Assessing sensitivity and detection of HTS approaches in such cases is paramount, but time-consuming and expensive: specialized experimental protocols and a sufficient quantity of samples are required for processing and analysis. To overcome these limitations, we propose a new computational approach specifically designed for the generation of artificial datasets suitable for this task, simulating ultra-deep targeted sequencing data with low-fraction variants and demonstrating their effectiveness in benchmarking low-fraction variant calling.ResultsOur approach enables the generation of artificial raw reads that mimic real data without relying on pre-existing data by using NEAT, a fine-grained read simulator that generates artificial datasets using models learned from multiple different datasets. Then, it incorporates low-fraction variants to simulate somatic mutations in samples with minimal tumor DNA content. To prove the suitability of the created artificial datasets for low-fraction variant calling benchmarking, we used them as ground truth to evaluate the performance of widely-used variant calling algorithms: they allowed us to define tuned parameter values of major variant callers, considerably improving their detection of very low-fraction variants.ConclusionsOur findings highlight both the pivotal role of our approach in creating adequate artificial datasets with low tumor fraction, facilitating rapid prototyping and benchmarking of algorithms for such dataset type, as well as the important need of advancing low-fraction variant calling techniques.

Aminomethylphosphonic Acid (AMPA), a Glyphosate Metabolite, Decreases Plasma Cholinesterase Activity in Rats

Glyphosate, a widely used herbicide, is linked to a plethora of deleterious effects in both clinical and preclinical studies. Nevertheless, the effects of its main metabolite, aminomethylphosphonic acid (AMPA), whose half-life in soil is even longer than that of glyphosate, have been little explored. On this basis, as a first approach, in this work, we report that intraperitoneal (i.p.) administration of AMPA or glyphosate (at 10, 56, and 100 mg/kg) decreased, to a similar extent, plasma cholinesterase (ChE) activity in acutely exposed rats. Moreover, we designed an experimental protocol to analyze and compare the effects of AMPA and glyphosate on human plasma ChE activity; this protocol consisted of adding these compounds to human plasma to subsequently test the effects of this plasma on the contraction to acetylcholine (ACh) in the frog rectus abdominis muscle (an indirect estimate of ChE activity). Accordingly, this muscular contraction to ACh was evaluated before and after pre-incubation of ACh with (i) plasma alone, (ii) plasma with AMPA, and (iii) plasma with glyphosate. Our results indicate that AMPA, like glyphosate, decreased ChE activity in the plasma of rats (when given i.p.) and humans (when added in vitro), suggesting that both xenobiotics may exert similar toxicological effects.

Characterizing the oligomers distribution along the aggregation pathway of amyloid Aß1-40 by NMR.

This study delves into the early aggregation process of the Aβ1-40 amyloid peptide, elucidating the associated oligomers distribution. Motivated by the acknowledged role of small oligomers in the neurotoxic damage linked to Alzheimer's disease, we present an experimental protocol for preparing 26-O-acyl isoAβ1-40, a modified Aβ1-40 peptide facilitating rapid isomerization to the native amide form at neutral pH. This ensures seed-free solutions, minimizing experimental variability. Additionally, we demonstrate the efficacy of coupling NMR diffusion ordered spectroscopy (DOSY) with the Inverse Laplace Transform (ILT) reconstruction method, for effective characterization of early aggregation processes. This innovative approach efficiently maps oligomers distributions across a wide spectrum of initial peptide concentrations offering unique insights into the evolution of oligomers relative populations. As a proof of concept, we demonstrate the efficacy of our approach assessing the impact of Epigallocathechin gallate, a known remodeling agent of amyloid fibrils, on the oligomeric distributions of aggregated Aß1-40. The DOSY-ILT proposed approach stands as a robust and discriminating asset, providing a powerful strategy for rapidly gaining insight into potential inhibitors' impact on the aggregation process.

Overcoming noise in quantum teleportation with multipartite hybrid entanglement.

Quantum entanglement and decoherence are the two counterforces of many quantum technologies and protocols. For example, while quantum teleportation is fueled by a pair of maximally entangled resource qubits, it is vulnerable to decoherence. Here, we propose an efficient quantum teleportation protocol in the presence of pure decoherence and without entangled resource qubits entering the Bell-state measurement. Instead, we use multipartite hybrid entanglement between the auxiliary qubits and their local environments within the open-quantum system context. With a hybrid-entangled initial state, it is the decoherence that allows us to achieve high fidelities. We demonstrate our protocol in an all-optical experiment.

Experimental Protocols for Sustainable Ammonia Production by Photocatalytic Nitrogen Fixation: Pitfalls and Remedial Measures

AbstractThe synthesis of ammonia (NH3) by photocatalytic nitrogen (N2) fixation has gained tremendous attention from researchers worldwide. The number of reports on different materials for photocatalytic N2 fixation is increasing year by year in the quest for developing breakthrough and sustainable photocatalysts in this field. However, there are several pitfalls (nitrogenous impurities in feed gas and on the surface of the catalyst, reaction conditions, use of scavengers, NH3 quantification methods, etc.) in the path of photocatalytic N2 fixation experiments, which can lead to the reporting of bogus NH3 production rates. Therefore, the use of accurate experimental protocols for the quantification of photogenerated NH3 requires immediate attention and focus of the researchers so that reliable data can be reported in the literature. This perspective article mainly focuses on generating awareness in the photocatalytic N2 fixation research community about the recent establishments for reporting experimental results in this field. Several pitfalls that may lead to the wrong data reporting and remedial measures to avoid them are discussed in detail. Finally, a summary of the recent advancements in this field and recommendations on future directions is provided.

An Apple a Day Keeps the Gray Mold Away

Most consumers dispose of rotten food without a second thought; however, they also throw away a dynamic group of plant pathogens that can be utilized for inquiry-driven investigations into host/pathogen interactions. Botrytis cinerea is a common necrotrophic fungus that can infect most plants but causes substantial losses to the grape and fresh berry industries. Because most store-bought strawberries eventually succumb to this pathogen (due to the presence of spores from the field or packing facility), they are a dependable source of fungal inoculum to test novel hypotheses about the nature of disease. Across the produce aisle, apples are a diverse, well-characterized, and susceptible host population that enables students to construct individualized experiments about the nature of disease with adequate replication for meaningful analysis. This experimental protocol will outline how to conduct an infection assay with B. cinerea and commercially available apple varieties for students to develop their own experiments, inoculate their own plants, and analyze their own data to answer important questions about how pathogens cause disease.

SEX DIFFERENCES IN CEREBRAL BLOOD FLOW VELOCITY RESPONSES TO EXERCISE IN THE HEAT

INTRODUCTION &amp; AIMS Global warming poses a risk for the development of heat-related physiological impairment, which can be aggravated when exercising in hot conditions. The aim of the present study was to investigate acute effects of exercising in hot conditions on cerebral blood flow velocity and systolic function in healthy individuals and to explore possible sex differences. METHODS The experimental condition consisted of walking on a treadmill, at 5km/h and 2% incline, inside a heat chamber at 40°C (50%RH), for 90 minutes. Middle cerebral artery blood flow velocity (MCAv) and left ventricular global longitudinal strain (GLS; a sensitive index of systolic function), were assessed at baseline and every 30 minutes by means of transcranial Doppler and speckle-tracking echocardiography, respectively. Data is expressed in delta (Δ) and standard error. RESULTS Twenty-six individuals (13♂,13♀ 27.1±1.0yrs, P=0.02) completed the experimental protocol. Both males and females exhibited non-significant increases in MCAv from baseline at 30 minutes (♂Δ=2.55±2.15 P&amp;gt;0.05; ♀Δ=0.54±2.53cm.s-1, P&amp;gt;0.05; interaction P=0.63), followed by significant decreases relative to 30min, at 60min (♂Δ=-4.0±1.23 P=0.04; ♀Δ=-5.41±1.56cm.s-1, P=0.03; interaction P=0.63) and 90 minutes (♂Δ=-6.08±1.37 P&amp;lt;0.01; ♀Δ=-7.39±1.40cm.s-1, P&amp;lt;0.01; interaction P=0.63). In males, there was a significant decrease in GLS from baseline at 30min (Δ=2.44±0.69%, P&amp;lt;0.05), 60 (Δ=2.79±0.73%, P=0.03), and 90 (Δ=3.49±0.89%, P=0.03) minutes; no significant changes were observed in females. CONCLUSION Males and females presented similar patterns of change in cerebral blood flow velocity, including significant decreases with prolonged heat exertion. These changes occur in both sexes, despite changes in systolic strain only being apparent in males. These data suggest that sex differences may exist in the regulation of cerebrovascular responses to exercise in the heat in humans.

Determining relative permeability and capillary pressure from mixed-wet core floods

The main goal of this paper is a laboratory method development for determining the capillary pressure and relative permeability from coreflooding test specifically for mixed-wet rocks. Previously, the steady-state transient test (SSTT) was designed to determine both relative permeability (Kr) and capillary pressure (Pc) from a single steady-state coreflood by using the transient data of routine steady-state tests. On the contrary to the previous works, where SSTT was developed for completely hydrophobic or hydrophilic outcrop cores, this paper determines Kr and Pc for mixed-wet cores. Depending on the capillary pressure equation applied, the mathematical model for two-phase flow in mixed-wet rocks contains one or two extra constants, so some extra measurements must be taken during SSTT, to determine Pc and Kr curves. We change the experimental protocol by establishing a uniform initial saturation Swi by evaporation method. We also include bump floods at two high rates for the alternative determination of saturation and relative permeability for residual oil. A new inverse solver determines the set of model constants that employs van Genuchten's Pc formula and a vaporization procedure for initial core saturation. The number of resulting model coefficients is equal to seven and matches the dimension of the measured data array for mixed-wet cores.The developed SSTT for mixed-wet rocks is applied and validated for both high-salinity (HS) and low-salinity (LS) waterfloods. Strong agreement between laboratory steady-state, transient, and bump-flood data and those obtained by mathematical modelling – R2 is above 0.99 for steady-state data and above 0.9 for transient data - validates the proposed SSTT procedure and inverse solver for mixed-wet cores and HS and LS waterfloods. Our findings indicate that low salinity has a greater effect in expanding the range of positive capillary pressure compared to high salinity. This suggests an increase in water-wettability as the salinity decreases.

Identification of constitutive materials of bi-layer soft tissues from multimodal indentations

The personalisation of finite element models is an important problem in the biomechanical fields where subject-specific analyses are fundamental, particularly in studying soft tissue mechanics. The personalisation includes the choice of the constitutive law of the model’s material, as well as the choice of the material parameters. In vivo identification of the material properties of soft tissues is challenging considering the complex behaviour of soft tissues that are, among other things, non-linear hyperelastic and heterogeneous. Hybrid experimental-numerical methods combining in vivo indentations and inverse finite element analyses are common to identify these material parameters. Yet, the uniqueness and the uncertainty of the multi-material hyperelastic model have not been evaluated. This study presents a sensitivity analysis performed on synthetic indentation data to investigate the identification uncertainties of the material parameters in a bi-material thigh phantom. Synthetic numerical data, used to replace experimental measurements, considered several measurement modalities: indenter force and displacement, stereo-camera 3D digital image correlation of the indented surface, and ultrasound B-mode images. A finite element model of the indentation was designed with either Ogden-Moerman or Mooney-Rivlin constitutive laws for both materials. The parameters’ identifiability (i.e. the possibility of converging to a unique parameter set within an acceptable margin of error) was assessed with various cost functions formulated using the different synthetic data sets. The results underline the need for multiple experimental modalities to reduce the uncertainty of the identified parameters. Additionally, the experimental error can impede the identification of a unique parameter set, and the cost function depends on the constitutive law. This study highlights the need for sensitivity analyses before the design of the experimental protocol. Such studies can also be used to define the acceptable range of errors in the experimental measurement. Eventually, the impact of the evaluated uncertainty of the identified parameters should be further investigated according to the purpose of the finite element modelling.

The Detection of Thoracolumbar Spine Injuries in Horses with Chronic Laminitis Using a Novel Clinical-Assessment Protocol and Ultrasonographic Examination.

Postural adaptation is a prominent feature in horses affected by laminitis. Laminitis induces intense pain, especially in the forelimbs, prompting affected horses to assume a caudally displaced trunk posture, resulting in the hyperflexion of the thoracolumbar spine. This study assessed the nature and prevalence of thoracolumbar injuries in horses with chronic laminitis compared to horses without it. Sixty horses were used (thirty laminitic and thirty non-laminitic) of different athletic purposes and ages (2-20 years). The experimental protocol entailed a single assessment of horses' thoracolumbar spines, utilizing physical examination by MACCTORE, a scoring system developed specifically for this study. Additional evaluations included the Grimace Equine Pain Scale (HGS) and ultrasound exams. Statistical tests were used to compare values (Mann-Whitney or t-test) and lesions prevalences (Fisher) between groups (p < 0.05). The results showed a higher pain manifestation (HGS and heart rate, p < 0.0001) and thoracolumbar-spine-injury levels in chronic laminitis horses, both in MACCTORE clinical examinations (11.7 ± 4.8 vs. 4.2 ± 3.3, p < 0.0001) and general ultrasonographic indices (39.6 ± 12.0 vs. 20.7 ± 7.1, p < 0.0001), including specific examination approaches for various spinal elements. Horses with laminitis presented with a 14-fold higher prevalence of ultrasound-relevant lesions in the thoracolumbar spine (CI: 4.4 to 50.6, p < 0.0001) compared to controls. These findings constitute new evidence of an association between chronic laminitis and the presence of thoracolumbar spine injuries in horses, which may be confirmed by more sophisticated study designs.

Variability and bias in microbiome metagenomic sequencing: an interlaboratory study comparing experimental protocols.

Several studies have documented the significant impact of methodological choices in microbiome analyses. The myriad of methodological options available complicate the replication of results and generally limit the comparability of findings between independent studies that use differing techniques and measurement pipelines. Here we describe the Mosaic Standards Challenge (MSC), an international interlaboratory study designed to assess the impact of methodological variables on the results. The MSC did not prescribe methods but rather asked participating labs to analyze 7 shared reference samples (5 × human stool samples and 2 × mock communities) using their standard laboratory methods. To capture the array of methodological variables, each participating lab completed a metadata reporting sheet that included 100 different questions regarding the details of their protocol. The goal of this study was to survey the methodological landscape for microbiome metagenomic sequencing (MGS) analyses and the impact of methodological decisions on metagenomic sequencing results. A total of 44 labs participated in the MSC by submitting results (16S or WGS) along with accompanying metadata; thirty 16S rRNA gene amplicon datasets and 14 WGS datasets were collected. The inclusion of two types of reference materials (human stool and mock communities) enabled analysis of both MGS measurement variability between different protocols using the biologically-relevant stool samples, and MGS bias with respect to ground truth values using the DNA mixtures. Owing to the compositional nature of MGS measurements, analyses were conducted on the ratio of Firmicutes: Bacteroidetes allowing us to directly apply common statistical methods. The resulting analysis demonstrated that protocol choices have significant effects, including both bias of the MGS measurement associated with a particular methodological choices, as well as effects on measurement robustness as observed through the spread of results between labs making similar methodological choices. In the analysis of the DNA mock communities, MGS measurement bias was observed even when there was general consensus among the participating laboratories. This study was the result of a collaborative effort that included academic, commercial, and government labs. In addition to highlighting the impact of different methodological decisions on MGS result comparability, this work also provides insights for consideration in future microbiome measurement study design.

A minor tweak in transplant surgery protocols alters the cellular landscape of the arterial wall during transplant vasculopathy

IntroductionTransplant vasculopathy (TV) is a major complication after solid organ transplantation, distinguished by an arterial intimal thickening that obstructs the vascular lumen and leads to organ rejection. To date, TV remains largely untreatable, mainly because the processes involved in its development remain unclear. Aortic transplantation in mice, used to mimic TV, relies on highly variable experimental protocols, particularly regarding the type of anastomosis used to connect the donor aorta to the recipient. While the amount of trauma undergone by a vessel can dramatically affect the resulting pathology, the impact of the type of anastomosis on TV in mice has not been investigated in detail.MethodsIn this study, we compare the cellular composition of aortic grafts from BALB/C donor mice transplanted into C57BL/6J recipient mice using two different anastomosis strategies: sleeve and cuff.ResultsWhile both models recapitulated some aspects of human TV, there were striking differences in the cellular composition of the grafts. Indeed, aortic grafts from the cuff group displayed a larger coverage of the neointimal area by vascular smooth muscle cells compared to the sleeve group. Aortic grafts from the sleeve group contained higher amounts of T cells, while the cuff group displayed larger B-cell infiltrates.DiscussionTogether, these data indicate that a seemingly minor technical difference in transplant surgery protocols can largely impact the cellular composition of the graft, and thus the mechanisms underlying TV after aortic transplantation in mice.

Conjunctive use of floodwater harvesting for managed aquifer recharge and irrigation on a date farm in Morocco

AbstractIn arid regions, harvesting floodwater can mitigate irrigation‐induced groundwater depletion by providing additional surface water and recharging aquifers. We designed an experimental protocol to quantify these fluxes on a date farm located along the Wadi Satt, whose flow originates from the Anti‐Atlas Mountains in south‐eastern Morocco. Automatic barometric sensors were used to monitor the water level in a 6500 m3 floodwater harvesting pond and in surrounding boreholes. Six flood events occurred from 2021 to 2023. The pond water balance indicated that most stored water is pumped for irrigation (56% of harvested floodwater). More than 40% infiltrates at a rate of approximately 90 mm day−1, and the remainder evaporated. Analytical modelling of the pond water table system showed that the radius of the piezometric mound resulting from pond infiltration is less than 360 m. Groundwater recharge from the irrigated plot could be observed after two close floods that enabled continuous pumping for several weeks, suggesting that in this specific context, over‐irrigation using surface water allows the aquifer to be recharged. The hydrological effects of possible future expansion of these ponds at the watershed scale should be analysed to assess possible negative impacts on downstream water resources.

Experimental Infections Reveal Acquired Zoonotic Capacity of Human Schistosomiasis Trough Hybridization.

We are currently witnessing the endemization of urogenital schistosomiasis in southern Europe. The incriminated parasite is a hybrid between a human parasite and a livestock parasite. Using an experimental evolutionary protocol, we created hybrid lines from pure strains of both parasite species. We showed that the host spectrum of the human parasite is enlarged to the livestock parasite after genomic introgression. We also evidenced that the tropism of the parasites within the host changes and that some hybrid lines are more virulent than the parental strains. These results engage a paradigm shift from human to zoonotic transmission of urogenital schistosomiasis.