Resistance Water Research Articles

PocketWATCH: design and operation of a multi-use test bed for water Cherenkov detector components in pure and gadolinium loaded water

The PocketWATCH facility is a unique multi-purpose test bed designed to replicate the conditions of large water Cherenkov detectors. Housed at the University of Sheffield, the facility consists of a light-tight 2000 L ultrapure water tank with purification and temperature control systems. Water temperature, resistivity, and UV attenuation in the tank are monitored and shown to be stable over time. The system is also shown to be compatible with a solution of 0.2% gadolinium sulfate, allowing further utility in testing equipment bound for the next generation neutrino and nucleon decay water Cherenkov particle detectors. The relevant water quality parameters are shown to be stable whilst running in Gd-mode, thereby providing a suitable test bed for hardware development in a realistic, ex situ environment.

Integrating Rock Typing and Petrophysical Evaluations to Enhance Reservoir Characterization for Mishrif Formation in Garraf Oil Field

Accurate reservoir characterization is essential for successful hydrocarbon extraction, especially in complex fields such as the Garraf Oil Field. This study aims to enhance reservoir characterization by integrating different petrophysical assessments and rock typing methodologies. Density, neutron, and sonic porosity evaluations were used to assess porosity, while gamma-ray logs and resistivity measurements were used to determine shale volume. The Archie equation was employed to estimate water saturation and sensitivity analysis was used to determine the cutoff values. The study also utilized rock typing techniques, including hydraulic flow unit assessment and Rock fabric number cross-plots, to categorize reservoir rocks into flow units and identify unique rock types. The combination of these approaches led to the precise identification of reservoir heterogeneities and optimal oil production zones. The results showed that the Gamma-ray log is the best method for determining shale volume, and the closest method for porosity determination is the density log. The water resistivity value was estimated at 0.016, while the Archie parameters (a,m,n) were 1.1, 2.1, and 3.7, respectively, with cutoff values of 0.22 for shale volume, 0.11 for porosity, and 0.56 for water saturation. The study identified five rock types ranging from packstone, pack to wackstone, wackstone, wack to mudstone, and mudstone. Overall, the integration of petrophysical evaluations and rock typing techniques facilitates the accurate delineation of oil-rich zones with enhanced reservoir connectivity.

Microbial Contamination and Antibiotic Resistance in Food and Water: Assessing the Threat of Staphylococcus aureus in Lahore Metropolitan

Background: The research project in Lahore, Pakistan, seeks to detect S. aureus in drinking water, raw milk, and yogurt samples due to health concerns. S. aureus is a pathogenic bacterium with potential risks if present in food and water sources.Method: In this study, 300 samples of raw milk, yogurt, and drinking water were collected in Lahore. The presence of S. aureus was determined through morphological, microscopic, and biochemical methods. The biochemical analysis included testing for specific features of S. aureus. Disk diffusion technology was employed to assess the antimicrobial susceptibility of the isolates, following the recommendations of the Clinical Laboratory Standards Institute. Molecular confirmation was achieved through 16S rRNA sequence analysis using universal and specific primers.Results: The investigation uncovered that 6% of drinking water samples, 9% of yogurt samples and 58% of raw milk samples were tainted with S. aureus. These findings were further validated through 16S rRNA sequence analysis, affirming their reliability. S. aureus exhibited notable resistance rates, with 100% resistance to penicillin and 95% resistance to erythromycin. Conversely, resistance to ciprofloxacin and gentamicin was lower, at 10% and 5% each, indicating the potential efficacy of these antibiotics in treating S. aureus infections.Conclusion: The study emphasizes the risk of S. aureus infection from raw milk consumption in Lahore, Pakistan, due to inadequate sanitary practices. It stresses the necessity of implementing stricter measures in dairy production and water treatment to ensure public safety and reduce multidrug-resistant bacteria prevalence. Continuous monitoring and preventive actions are vital for safeguarding public health.Keywords: S. aureus; Antibiotic resistance; Food and water; Lahore, Pakistan; Sanitary measures

Experimental study on impedance dispersion characteristics and electrical resistivity of high temperature granite

Electromagnetic methods are widely used in geothermal exploration. The electrical resistivity and impedance dispersion characteristics of high temperature rocks are the basis for the inversion interpretation of electromagnetic responses from geothermal reservoirs. Alternating current impedance spectroscopy experiments on granite at different temperatures and water contents were carried out. The impedance spectrum from these tests show that the resistivity of both dry and wet granite is mainly caused by grain boundaries or microfractures, rather than the mineral grains. The resistivity of granite decreases dramatically with the appearance of water, and decreases with increasing temperature. When temperature increases from 25 °C to 150 °C, the resistivity of dry granite decreases from 5690–5812 Ω·m to 5519–5638 Ω·m, while that of wet granite decreases from 3123–3278 Ω·m to 2618–2736 Ω·m. The relationship between temperature and resistivity can be described by an empirical equation, in which the temperature coefficient of dry granite is about 2.8 × 10−4, and that of wet granite is about 1.7 × 10−3. It shows the resistivity of wet granite is more significantly affected by temperature than that of dry granite. A mixing model describing resistivity of wet granite was established based on the resistivity of dry granite and water. This mixing model can also take temperature into consideration. Even though the equivalent porosity of granite is quite small, the resistivity of granite can still be described by Archie's equation, which was initially developed for high porosity sandstone. The coefficients in Archie's equation for granite were calculated from experimental results, with a tortuosity factor a = 0.005 and a cementation exponent m ranging from 1.50 to 1.75.

ULTRASONIC-ASSISTED ELECTRODEPOSITION OF CoMo/Al2O3 COMPOSITE COATING ON THE SURFACE OF STEEL AND ITS CORROSION RESISTANCE IN SIMULATED SEWAGE WATER

The ultrasonic is applied during the electrodeposition process of CoMo/Al2O3 composite coating on 10# steel to enhance its corrosion resistance in simulated sewage water. The influence of ultrasonic power on the thickness, roughness, chemical composition, surface morphology, and corrosion resistance of the composite coating is investigated. In an aqueous solution, a co-deposition of cobalt and molybdenum can be induced to form CoMo alloy coating. The Al2O3 nanoparticles are incorporated into CoMo alloy to form CoMo/Al2O3 composite coating. When the ultrasonic power increases from 0[Formula: see text]W to 100 W, the electrodeposition rate of the composite coating increases from 63.25[Formula: see text]mg/h to 153.73[Formula: see text]mg/h, and the thickness of the composite coating also increases from 15.6[Formula: see text][Formula: see text]m to 28.1[Formula: see text][Formula: see text]m. The surface roughness of composite coating electrodeposited without ultrasonic is about 0.436[Formula: see text][Formula: see text]m. The CoMo/Al2O3 composite coating electrodeposited at 100[Formula: see text]W ultrasonic power exhibits the smallest surface roughness of 0.193[Formula: see text][Formula: see text]m and presents a denser surface morphology composed of 74.4% Co, 10.3% Mo, and 15.3% Al, resulting in better corrosion resistance with the smallest corrosion current density of only 9.7[Formula: see text][Formula: see text]A/cm2. However, when the ultrasonic power is 150[Formula: see text]W, the intense hydrogen evolution on the surface of the cathode reduces the density of the coating surface, which leads to the deterioration of corrosion resistance.

Innovative solutions for global water quality challenges: insights from a collaborative hackathon event

Addressing the global water quality challenges requires collaborative efforts, multidisciplinary approaches, and innovative solutions. Here we report on the success of a special collective intelligence “hackathon event,” organized by five United Nations agencies and the European Commission, with the aim of reinventing engagement with diverse experts and stakeholders to tackle real-world challenges in water quality monitoring and assessment. Participants from diverse backgrounds and regions convened to devise inventive solutions in four key challenge areas, including (1) transformation of water quality data into water stewardship action, (2) empowering citizen scientists to improve water quality, (3) incorporation of Indigenous communities and their water quality knowledge in global information systems, and (4) routine monitoring of antimicrobial resistance in water. The hackathon approach fosters collective intelligence in a safe, creative and collaborative environment, enabling participants to harness their collective knowledge, expertise and skills. Key outcomes were conceptualizing practical frameworks and tailored toolboxes for diverse water quality innovations to improve monitoring, empower communities, and support policy-making. Emphasis was placed on the purpose and value of interdisciplinary collaborations to address complex global challenges, showcasing synergies between technology, environmental science, and social engagement. Hackathons are catalysts for collaborative innovation which unlock future endeavors in harnessing collective intelligence to safeguard our most precious resource – water.

Synergistic impact of heat and salicylic acid pretreatment on gluten films: Characterization and functional properties

This study investigates how wheat gluten (WG) films in the presence of salicylic acid are influenced by thermal pretreatment. Unlike previous methods conducted at low moisture content, our procedure involves pretreating WG at different temperatures (65 °C, 75 °C, and 85 °C), in a solution with salicylic acid. This pretreatment aims to enhance protein unfolding, thus providing more opportunities for protein-protein interactions during the subsequent solvent casting into films. A significant increase in β-sheet structures was observed in FTIR spectra of samples pretreated at 75 °C and 85 °C, showing a prominent peak in the range of 1630–1640 cm−1. The pretreatment at 85 °C was found to be effective in improving the water resistivity of the films by up to 247 %. Moreover, it led to a significant enhancement of 151 % in tensile strength and a 45 % increase in the elastic modulus. The reduced solubility observed in films derived from pretreated WG suggests the development of an intricate protein network arising from protein-protein interactions during the pretreatment and film formation. Thermal pretreatment at 85 °C significantly enhances the structural and mechanical properties of WG films, including improved water resistivity, tensile strength, and intricate protein network formation.

Corrosion resistance of 9–12Cr ODS steels in pressurized water for fusion application

The blanket design of Chinese fusion engineering test reactor (CFETR) may utilize pressurized water as coolant. The fusion structural materials will endure high temperature, high pressure and result in corrosion in the pressurized water. It is necessary to verify corrosion resistance of the materials. In the present study, three kinds of advanced fusion structural materials with excellent mechanical properties and neutron irradiation resistance, i.e., 9Cr-ODS steel, 9CrODS-Al steel, and 12CrODS-Al steel were immersed in pressurized water at 325 °C under the pressure of 15.5 MPa up to 859 h. Room-temperature tensile properties were investigated for the materials before and after corrosion. The oxidation layers of the steels were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ODS steels have good corrosion resistance in the pressurized water, especially the 9CrODS-Al and 12CrODS-Al steels. The outer oxide layer is identified as Fe2O3 for all the steels. The inner layer is mainly FeCr2O4 for the 9CrODS steel, and Fe(Al,Cr)2O4 for the ODS steels with Al element which better protect the steels from further corrosion. The relevant properties data can provide reference for the blanket materials choice of CFETR and the future fusion reactors.

A new method for improving the resistance of cement-based materials to carbonic acid water corrosion: Carbonation curing and further water curing

Accelerated carbonation curing has several advantages compared with traditional moisture curing in terms of decreasing the duration time of early curing and improving the mechanical properties, dimensional stability and durability of concrete. This study investigated the effect of accelerated carbonation curing and further water curing on corrosion behavior, corrosion products, and pore structure of cement mortar and paste samples exposed to carbonic acid water corrosion. The results indicate the accelerated carbonation curing reduces corrosion depth and mitigates the decline in compressive strength caused by carbonic acid water corrosion. The accelerated carbonation curing can lead to the decalcification of C-S-H gel, and the formation of a large amount of CaCO3 and silica gel (SiO2·γH2O) on the surface of the C-S-H gel, which play a crucial role in the corrosion resistance of carbonic acid water. CaCO3, firstly, fills pores and optimizes the pore structure, slowing down the diffusion rate of carbonic acid water. Meanwhile, an essential "protective layer" forms on the surface due to abundant CaCO3, effectively preventing further corrosion of internal C-S-H gel, CH, C2S, and C3S. At the later age of corrosion, the carbonic acid water can lead to the decalcification shrinkage of CaCO3, and the deterioration of pore structure, which adversely affects the mechanical properties of cement-based materials.

Modeling the impact of urban and hospital eco-exposomes on antibiotic-resistance dynamics in wastewaters

The emergence and selection of antibiotic resistance is a major public health problem worldwide. The presence of antibiotic-resistant bacteria (ARBs) in natural and anthropogenic environments threatens the sustainability of efforts to reduce resistance in human and animal populations. Here, we use mathematical modeling of the selective effect of antibiotics and contaminants on the dynamics of bacterial resistance in water to analyze longitudinal spatio-temporal data collected in hospital and urban wastewater between 2012 and 2015. Samples were collected monthly during the study period at four different sites in Haute-Savoie, France: hospital and urban wastewater, before and after water treatment plants. Three different categories of exposure variables were collected simultaneously: 1) heavy metals, 2) antibiotics and 3) surfactants for a total of 13 drugs/molecules; in parallel to the normalized abundance of 88 individual genes and mobile genetic elements, mostly conferring resistance to antibiotics. A simple hypothesis-driven model describing weekly antibiotic resistance gene (ARG) dynamics was proposed to fit the available data, assuming that normalized gene abundance is proportional to antibiotic resistant bacteria (ARB) populations in water. The detected compounds were found to influence the dynamics of 17 genes found at multiple sites. While mercury and vancomycin were associated with increased ARG and affected the dynamics of 10 and 12 identified genes respectively, surfactants antagonistically affected the dynamics of three genes. The models proposed here make it possible to analyze the relationship between the persistence of resistance genes in the aquatic environment and specific compounds associated with human activities from longitudinal data. Our analysis of French data over 2012–2015 identified mercury and vancomycin as co-selectors for some ARGs.

Stretchable, stable, and structural color reversible enabled by mesoscopic regulation and design for flexible photonic crystal mechanical sensors

This paper reports a flexible mechanical sensor developed by combining an opal photonic crystal and a flexible medium through UV curing technology. Under the action of external force, the deformation of the flexible medium causes the change of the photonic crystal lattice constant, which leads to the displacement of the reflection peaks, thus realizing the detection of the deformation of the film. The flexible medium is mixed by photoinitiators and polymer monomers, and its mechanical properties are directly related to the mass fraction of photoinitiators and polymer monomers. The results show that the film can reach a maximum strain of about 180% when the mass fraction of photoinitiator is 3% and the volume ratio of the polymer functional monomers is 8:2. In addition, for the responsiveness test of the sensor under tensile, the results show that at 0%, 26%, and 78% of tensile strain, its structural color is blue-shifted sequentially, and its spectral peaks are 668 nm, 535 nm, and 488 nm, respectively. Finally, the sensor is applied to the detection of acoustic waves in air, and it is found that its spectral response peaks can be obtained for acoustic waves of different frequencies (250–650 Hz), and a spectral peak at 500 Hz. This flexible photon sensor has the potential to match the acoustic resistance of water. It will greatly expand the response research of ocean exploration in the low frequency range.

Simultaneous adjustment on the CO2/oil and CO2/water interface tensions using hydrophilic, lipophilic and CO2-philic surfactants during CO2 flooding to enhance shale oil recovery after hydraulic fracturing

It is an urgent demand to further enhance shale oil recovery after large-scale hydraulic fracturing with a low oil recovery. CO2 flooding technology has been demonstrated to effectively develop shale oil, however, the residual water after hydraulic fracturing can influence the efficiency of CO2 flooding because of the high CO2-water interfacial tension. Here, the hydrophilic, lipophilic and CO2-philic surfactants were investigated to simultaneously adjust the CO2/oil and CO2/water interface tension to accelerate the oil and water flows to enhance shale oil recovery. The results show that the low-carbon alcohol polyoxyethylene polyoxypropylene ether has the hydrophilic, lipophilic and CO2-philic properties. The alkyl chain length and PO groups have great influence on the interfacial tension of CO2-oil, while the presence of EO groups can significantly reduce the interfacial tension of CO2-water. The surfactant of C4EO3PO6 can not only demonstrate the best performance in reducing the interfacial tensions of shale oil-CO2 and water-CO2, but also decrease the minimum miscibility pressure (MMP) of the shale oil-CO2 system to 18.89 MPa from 24.10 MPa. The interfacial tension between water and the CO2 + 1.0 wt% C4EO3PO6 system can be decreased to 6.62 mN/m at 28 MPa and the reduction rate is 56.10 %. The enhancement of surfactants on the extraction effect of CO2 and the mutual diffusion process between CO2 and shale oil or water interface is the major mechanism to decrease the interfacial tensions. Therefore, the addition of surfactant in CO2 can simultaneously decrease the interfacial tensions of CO2-oil and CO2-water and has a potential to enhance shale oil recovery by reducing the capillary resistance of residual water after hydraulic fracturing and increasing the miscibility between CO2 and oil.

Fishing Vessel Bulbous Bow Hydrodynamics—A Numerical Reverse Design Approach

Naval hydrodynamics typically focus on reducing ship resistance, which can be achieved by incorporating a bulbous bow. This feature is commonly used in the merchant fleet and smaller vessels, such as fishing boats, to minimize wave-making resistance. However, it is important to note that the use of a bulbous bow may not always be necessary or effective in all ship designs. In some cases, fishing ship designs may include a bulbous bow that is not optimized due to the use of procedures and methods intended for larger merchant ships or based on past experience. This study examines the effect of different bow designs, including the bulbous bow, on ship resistance in calm water, with a focus on a typical Argentinian trawler fishing vessel. The objective of this research is to assess the hydrodynamics of various designs for a particular ship by modifying its vessel lines. Firstly, the bulbous bow is removed, and then the reduction in ship resistance achieved by the bulbous bow under different load conditions and speeds is evaluated by comparing the vessel with and without the bulbous bow. The numerical analysis is performed using OpenFOAM, and the results are validated through towing tank experiments. This research indicates that the performance of the bulbous bow varies under different conditions. Therefore, it is recommended to conduct an initial study and a full evaluation of the design and operation alternatives.

Effect of the use of resistance training Devices (inside and outside water) to develop the rapid force of the arms and its relation to the achievement of the swimmers 50 meters free

The scientific development in the field of sports begins to take qualitative steps in the methods, means and devices used in training. This development also requires to know about the importance and impact of those means and methods that serve the achievement of sport and progress, especially in swimming sport. Here the importance of research has emerged in determining the importance of the methods and training devices used within And outside water to develop the swimmer's ability that can affect the level of digital achievement of swimmers 50 meters free. The research problem is to research and identify any of these methods that have a more effective effect on the development of the rapid force and the digital achievement of the arms and legs of the swimmers 50 meters swimming. The study aimed to identify any of the methods of training following the development of rapid power and digital completion of the movements of the arms and legs of swimmers 50 meters Free. The sample of the research consisted of 8 players from the Iraqi swimmers. The Iraqi swimming team was divided into two experimental groups, one that preaches iron weight training exercises outside the water and the other is a device designed for resistance in water. The results showed that the use of exercises with resistors in the water has a greater advantage than the devices outside the water in the development of rapid strength and completion of movements of the arms and legs of swimmers 50 m free. The recommendations are the need to use exercises with similar resistance to perform in the water in the training of force from the other to gain time and effort in advancing the level of swimmers in the training of teams in the periods of preparation of public and private

Integrated Petrophysical Evaluation and Rock Physics Modeling of Broom Creek Deep Saline Aquifer for Geological CO2 Storage

Fossil fuels, such as coal and hydrocarbons, are major drivers of global warming and are primarily responsible for worldwide greenhouse gas emissions, including carbon dioxide CO2. The storage of CO2 in deep saline reservoirs is acknowledged as one of the top practical and promising methods to reduce CO2 emissions and meet climate goals. The North Dakota Industrial Commission (NDIC) recently approved the fourth Class VI permit for a carbon capture and storage project in the Williston basin of North Dakota for the geological CO2 storage in the Broom Creek formation. The current research aimed to conduct a comprehensive petrophysical characterization and rock physics modeling of the Broom Creek deep saline reservoir to unravel the mineralogical distribution and to understand the variations in petrophysical and elastic properties across the formation. This study utilized geophysical well logs, routine core analysis, and advanced core analysis to evaluate the Broom Creek formation. Multimineral petrophysical analysis calibrated with X-ray diffraction results reveals that this formation primarily comprises highly porous clean sandstone intervals with low-porosity interspersed with dolomite, anhydrite, and silt/clay layers. The formation exhibits varying porosities up to 0.3 and Klinkenberg air permeabilities up to ∼2600 mD. The formation water resistivity using Archie’s equation is approximately 0.055 ohm-m at 150 °F, corresponding to around 63,000 ppm NaCl salinity, which is consistent with prior data. The pore throat distribution in the samples from clean sandstone intervals is primarily situated in the macro-mega scales. However, the presence of anhydrite and dolomite impedes both porosity and pore throat sizes. The accurate prediction of effective elastic properties was achieved by developing a rock physics template. Dry rock moduli were modeled using Hill’s average, while Berryman’s self-consistent scheme was employed for modeling saturated moduli.

Modeling of aquifer geo-hydraulic characteristics with geo-electrical methods at a major coastal aquifer system in Uyo, southern Nigeria

Abstract Characterization of aquifer geo-hydraulic properties is essential for groundwater management and conservation. This work demonstrates the use of electrical resistivity surveying data in the characterization of important geo-hydraulic properties within a major coastal aquifer in southern Nigeria. Geo-electrical data acquired along profile lines with the use of Schlumberger array configuration were used to determine the aquifer geo-hydraulic parameters such as aquifer resistivity ρb, water resistivity ρw, porosity Φ, formation factor F, hydraulic conductivity K, transmissivity T, permeability Kp, and tortuosity τ. The resistivity inversion models delineated the occurrence of four lithological layers, with resistivity of the geo-layers ranging from 2.4 to 4,393 Ω m. Contour maps were created to show the distribution of the various geo-electrical and geo-hydraulic parameters over the study area. Regression curves showing the relationship between the geo-hydraulic parameters were generated and used to generate empirical relationships between the parameters. The empirical formulas developed for these geo-hydraulic parameters will aid in future work seeking to characterize aquifer zones and model aquifer geo-hydraulic units. In all, electrical resistivity surveying was found to be a noninvasive, cost-effective, and efficient method of characterizing aquifer geo-hydraulic properties via nonpoint geo-electrical data collected over the earth's surface.

Numerical simulation of liquid water transport in ordered microstructures gas diffusion layer of proton exchange membrane fuel cell

The performance of the gas diffusion layer (GDL) plays a pivotal role in ensuring the efficient and stable operation of proton exchange membrane fuel cells (PEMFCs). Microstructure of the GDL significantly influences its internal water transport capabilities. In this article, the lattice array method is employed to construct ordered microstructures within GDLs, followed by the utilization of phase field method to numerically simulate water transport among these structures. The effects of lattice edge length, lattice height, and lattice shape on water transport throughout the GDL are investigated. The results reveal that excessively large or small lattice edge lengths detrimentally affect effective water transport within the GDL. Additionally, a smaller lattice height can accelerate the breakthrough of liquid water through the GDL. Notably, when the lattice height is smaller than the lattice edge length, it enhances the mass transfer. Moreover, the triangular lattice impedes the water flow, while the rectangular structure diminishes the transmission efficiency of liquid water. In contrast, hexagonal and octagonal structures exhibit the ability to alleviate the transport resistance of liquid water, with the octagonal lattice demonstrating superior mass transfer effectiveness. These findings underscore the paramount importance of meticulous structural design in further augmenting the mass transfer performance of ordered GDLs. The research provides meaningful guidance for the design of GDL structures.

Helical TPU/Ag@K2Ti4O9 fibers with shape memory performance for highly stretchable and sensitive strain sensors

Even though wearable electronics based on e-textiles have been attracting increasing attention, their unsatisfactory durability has significantly impeded their practical applications. In this regard, thermoplastic polyurethane (TPU)/Ag@K2Ti4O9 composite fibers with excellent mechanical properties and conductivity along with outstanding durability have been successfully prepared via wet-spinning in this work. However, it still has some shortcomings, such as a high modulus mismatch with skin, and slow resistance recovery after stretching when applied to human sensing. Therefore, helical fibers have been further developed, which are sturdy and do not bring any uncomfortably wearable electronics (the fracture stress is greater than 0.4 N and an elongation of 50% can be achieved under only 0.01 N with a 40% increased resistance). The resultant helical composite fiber has stable sensing performance under 100% strain, with a gauge factor (GF) up to 0.8–1.5. In particular, it can quickly recover its original length and resistance in hot water or under an infrared lamp due to the thermal shrinkage effect of PU when it breaks under destructive overstretch (greater than 300% strain). This durable, repairable, and cost-effective helical fiber can provide new insights into the design and promotion of fibrous human-computer interaction components.

Do Microorganisms in Bathing Water in Guadeloupe (French West Indies) Have Resistance Genes?

Waterborne faecal contamination is a major public health concern. The main objectives of this study were to investigate faecal contamination and Escherichia coli (E. coli) antibiotic resistance in recreational fresh water from Guadeloupe and to characterise the microbiome and resistome composition in biofilms from submerged rocks. Significant faecal contamination was observed at 14 freshwater sites. E. coli predominated (62%), followed by Enterobacter cloacae (11%) and Acinetobacter spp. (11%). Of 152 E. coli isolated, none produced extended-spectrum beta-lactamases (ESBLs), but 7% showed resistance to streptomycin and 4% to tetracycline. Biofilm resistome analysis revealed clinically significant antibiotic-resistance genes (ARGs), including those coding for resistance to sulfonamides (sul1), carbapenems (blaKPC), and third-generation cephalosporins (blaCTX-M). Mobile genetic elements (MGEs) (intI1, intI2, intI3) linked to resistance to aminoglycosides, beta-lactams, tetracycline, as well as heavy metal resistance determinants (copA, cusF, czcA, merA) conferring resistance to copper, silver, cadmium, and mercury were also detected. Diverse bacterial phyla were found in biofilm samples, of which Proteobacteria, Bacteroidetes, Planctonomycetes, and Cyanobacteria were predominant. Despite the frequent presence of E. coli exceeding regulatory standards, the low levels of antibiotic-resistant bacteria in freshwater and of ARGs and MGEs in associated biofilms suggest limited antibiotic resistance in Guadeloupean recreational waters.

Effect of combined training in water on hippocampal neuronal Plasticity and memory function in healthy elderly rats.

The cyclic AMP response element-binding protein (CREB) and nerve growth factor (NGF) have been proposed as key modulators of brain health and are involved in synaptic plasticity. The study investigates how combined water-based training affects hippocampal neuron plasticity and memory function in old rats. 16 Wistar male rats 24-month-old were randomly divided into two groups: combined training (n = 8) and control (n = 8). Four sessions were performed per week for 10 weeks, and consisted of resistance and endurance training in water. The control group was placed in a water container during training for 30 minutes to be homogenized in terms of the stress conditions. The.NGF and CREB genes in the hippocampus were evaluated and the working memory was measured using real-time PCR and Y-maze tests. The SPSS 26 software was utilized in which independent t-tests were used to analyze the genes and the Mann-Whitney U test was used to analyze functional memory with a significant level of (P < 0.05). The combined training resulted in a significant rise in NGF and CREB gene expression in the hippocampus tissue of elderly rats compared to the control group (P < 0.05); however, there was no notable difference in the Y maze performance test between the two groups (P < 0.05). These findings suggest that water-based combined training has beneficial effects on gene expression of NGF and CREB; however, it is necessary to conduct more studies to comprehend the effects of combined training on memory function.