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Ammonia colourimetric indicator for measuring urease and ureolytic bacteria concentrations
No full textAn effectively irreversible colourimetric ammonia (NH3) indicator is used to develop two new methods for determining the concentrations of, (i) urease [urease], and (ii) ureolytic bacteria under aerobic and anaerobic conditions. In both methods digital colour analysis (DCA) of a photographic image of the indicator is used to provide a value for the apparent absorbance, A′, which reflects the level of NH3 present. In (i) the indicator is placed in a solution containing urea and the urease sample under test, and photographed as a function of incubation time, t. DCA of the photographs yields an A′ vs t plot, from which a value for the time taken for the indicator to reach its half-way colour changing point, t50, is determined, the reciprocal of which is directly proportional to [urease]. In (ii), the indicator is placed in a Falcon™ tube containing a urea-based growth medium inoculated with a ureolytic bacterium of known concentration (units: CFU/mL), and photographed as a function of t. The resulting ‘S’ shaped A′ vs t profile is used to determine a value of the half-way colour change, the threshold time, TT, which is shown to be directly proportional to log(CFU/mL) over the range 101–108 CFU/mL for ureolytic bacteria such as P. stuartii and P. mirabilis, even in the presence of a non-ureolytic bacterial species, such as E. coli. The latter novel NH3 indicator based micro-respirometry method for measuring TVC (NH3 μR-TVC) works under anaerobic and aerobic conditions.<br/
A survey study on meta-heuristic-based feature selection approaches of intrusion detection systems in distributed networks
No full textWith the emergence of IoT and expanding the coverage of distributed networks such as cloud and fog, security attacks and breaches are becoming distributed and expanded too. Cybersecurity attacks can disrupt business continuity or expose critical data, leading to significant failures. The Intrusion Detection Systems (IDSs) as a remedy in such networks play a critical role in this ecosystem to find an attack at the earliest time and the countermeasure is performed if necessary. Artificial intelligence techniques such as machine learning-based and meta-heuristic-based approaches are being pervasively applied to prepare smarter IDS components from logged network traffic. The network traffic is recorded in the form of data sets for further analysis to detect traffic behavior from past treatments. Feature selection is a prominent approach in creating the prediction model to recognize feature network connection is normal or not. Since the feature selection problem in large datasets is NP-Hard and utilizing only heuristic-based approaches is not as efficient as desired, meta-heuristic-based approaches attract research attention to prepare highly accurate prediction models. To address the issue, this paper presents a subjective classification of published literature. Then, this presents a survey study on meta-heuristic-based feature selection approaches in preparing efficient IDSs. It investigates several kinds of literature from different angles and compares them in terms of used metrics in the literature to give broad insights into readers for advantages, challenges, and limitations. It can pave the way by highlighting research gaps for further processing and improvement in the future by interested researchers in the field.</p
Enhanced thermodynamic irreversibility and heat transfer in rotating graphene oxide–water nanofluids over a stretching surface
No full textEntropy generation plays a pivotal role in determining the efficiency of thermal systems involving nanofluids, impacting a wide range of engineering applications from energy systems to advanced manufacturing. This study presents a comprehensive analysis of thermodynamic irreversibility and heat transfer mechanisms in a rotating graphene oxide–water nanofluid flowing over a radiatively heated stretching surface with partial slip effects. To accurately capture nanoparticle influence, five distinct particle shapes — blade, brick, cylinder, platelet, and sphere — are integrated within a sophisticated two-phase nanofluid model. The investigation includes critical physical phenomena such as viscous dissipation, Joule heating induced by electromagnetic fields, and magnetohydrodynamic effects, reflecting realistic operational environments. Employing similarity transformations, the resulting nonlinear boundary value problem governing momentum and thermal fields is resolved numerically using MATLAB’s bvp4c solver. The results reveal that platelet-shaped nanoparticles facilitate superior heat transfer enhancement, albeit with increased entropy production, while spherical particles impose more substantial flow resistance. This work offers valuable theoretical insights and practical guidelines for optimizing nanofluid design in high-performance heat transfer systems, highlighting the delicate balance between augmenting thermal transport and minimizing irreversibility under complex flow conditions
Does being a service user of social work or an unpaid carer influence motivation to study social work?
No full textThis study draws upon findings from a cross-sectional survey of 278 social work students enrolled at one of six universities across Ireland. Multivariate multiple regression was used to examine the effects of being a past or current user of social work services, or a past or current unpaid carer, on their motivation to become a social worker. Most respondents were 23–30 years old and female. Wanting to help people and overcoming oppression were the main motivators to engage in professional training. Half identified as past or current unpaid carers, which significantly predicted motivation to become a social worker. Less than a third reported previous/current social work support due to witnessing domestic abuse, or the consequences of mental ill health or addiction as a child or adolescent. Others disclosed firsthand experiences of poverty, mental illness, addiction, bereavement or custody battles with ex-partners. Being a past or current service user significantly predicted motivation to become a social worker. The discussion suggests that universities explore ways to improve support for care experienced students or student carers to prevent withdrawals. Examples include a more robust and accessible mental health service, increased financial support, flexible approaches to assessment and meeting the requirements of placements.<br/
Rose Bengal as a multifunctional agent: from biomedical uses to catalysis and materials science
No full textSince its discovery in 1882, Rose Bengal (RB) has evolved from a vibrant textile dye into a multifaceted scientific asset with a versatile molecular platform spanning medicine, catalysis, and materials science. Initially developed for fabric coloring, RB has now become essential for a wide array of advanced technologies because of its intricate photochemical and photophysical properties. This review traces the remarkable journey of RB, emphasizing its inherent anticancer and antibacterial properties and role as a photosensitizer (PS) in contemporary cancer treatments and infectious diseases through photodynamic therapy (PDT), sonodynamic therapy (SDT), and combination therapy, where it facilitates targeted therapies by generating reactive oxygen species (ROS). The properties of RB are compared with FDA-approved and clinically explored photosensitizers currently available in the market. Promising results from RB clinical trials further underline its therapeutic potential. In addition to biomedical applications, RB contributes to enhanced drug delivery, catalysis, and microbiological applications while also demonstrating potential in sensing, solar energy conversion, and environmental remediation. Its established use in ophthalmology and emerging roles in neurodegenerative disease treatment reflect its expanding biomedical relevance. By exploring the mechanisms of action of RB and its integration into diverse systems, this review underscores its transformative potential across various disciplines, establishing RB as a pivotal agent in scientific and technological innovation.</p
The double life of a Palestinian translator: A bridge between wounds and words
No full textDit betoog beschouwt het vertalen van Gazaanse verhalen als een vorm van getuigenis afleggen over een wereld die dreigt te verdwijnen, waarbij taal zowel een overlevingsmiddel als een strijdtoneel wordt. In het licht van voortdurende pogingen tot het monddood maken en uitroeien van het Palestijne volk, bevindt de Palestijnse vertaler zich in een tussenpositie waarin hij/zij het verdriet van dat huidige moment, zoals geuit in alle intensiteit van het Arabisch, dient te vertalen naar een taal die zaken vaak onpersoonlijk, emotieloos en gecensureerd uitdrukt, en wellicht nooit is ontworpen om dergelijke mate van verwoesting te kunnen omvatten. Dit betoog reflecteert op de ethische kant van het vertalen van verhalen die zijn geboren temidden van het puin, van getuigenissen die zijn gevormd tussen luchtaanvallen, tussen herinneringen en de dreiging van stilte. Elk te vertalen woord moet een terrein doorkruisen dat vol ligt met machtsrelaties, taalkundige verhullingen of verbloemingen, en onverschilligheid. Dit dwingt de vertaler om de dunne lijn te bewandelen tussen enerzijds het afzwakken van menselijk verdriet ten behoeve van de leesbaarheid van de vertaling, en anderzijds het behouden van de urgentie ervan in een taal die in de regel menselijk lijden op geneutraliseerde wijze communiceert. Uitgaande van de Palestijnse ervaring, stelt dit betoog dat vertalen niet langer slechts een linguïstische oefening betreft, maar een politieke en morele taak, beladen met de verantwoordelijkheid om normalisering van gewelddadige bezetting en volksuitroeiing tegen te gaan, alsmede het scheppen van ruimte voor stemmen van hen die misschien niet meer leven als hun zinnen zijn uitgesproken. Tijdens het vertalen van Palestijnse bronnen draagt de vertaler niet alleen betekenis over, maar probeert tegelijkertijd ook Palestijns leven, autonomie en erfgoed te behouden in een wereld die daar vaak pas aandacht voor heeft als een te laat is