Search Results (4,715)

Coated SS316L is a potential alternative to the graphite bipolar plates (BPPs) used in proton-exchange membrane fuel cells (PEMFCs) owing to their low manufacturing cost and machinability. Due to their susceptibility to corrosion and passivation, which increases PEMFC ohmic resistance, protective and conductive coatings on SS316L have been developed. However, coating adhesion is one of the challenges in the harsh acidic environment of PEMFCs, affecting the performance and durability of BPPs. This study compares mechanical polishing and the frequently adopted chemical etchants for SS316L: Adler’s, V2A, and Carpenter’s etchant with different etching durations and their impact on the wettability, adhesion, and corrosion resistance of a Nb-coated SS316L substrate. Contact angle measurements and laser microscopy revealed that all etching treatments increased the hydrophobicity and surface roughness of SS316L substrates. Ex situ potentiodynamic and potentiostatic polarization tests and interfacial contact resistance analysis revealed high corrosion resistance, interfacial conductivity, and adhesion of the Nb-coated SS316L substrate pretreated with V2A (7 min) and Adler’s (3 min) etchant. Increased hydrophobicity (contact angle = 101°) and surface roughness (R_a = 74 nm) achieved using V2A etchant led to the lowest corrosion rate (3.3 µA.cm⁻²) and interfacial resistance (15.4 mΩ.cm²). This study established pretreatment with V2A etchant (a solution of HNO₃, HCl, and DI water (1:9:23 mole ratio)) as a promising approach for improving the longevity, electrochemical stability, and efficiency of the coated SS316L BPPs for PEMFC application. Full article

The rise of the Internet of Things (IoT) has transformed our daily lives by connecting objects to the Internet, thereby creating interactive, automated environments. However, this rapid expansion raises major security concerns, particularly regarding intrusion detection. Traditional intrusion detection systems (IDSs) are often ill-suited to the dynamic and varied networks characteristic of the IoT. Machine learning is emerging as a promising solution to these challenges, offering the intelligence and flexibility needed to counter complex and evolving threats. This comprehensive review explores different machine learning approaches for intrusion detection in IoT systems, covering supervised, unsupervised, and deep learning methods, as well as hybrid models. It assesses their effectiveness, limitations, and practical applications, highlighting the potential of machine learning to enhance the security of IoT systems. In addition, the study examines current industry issues and trends, highlighting the importance of ongoing research to keep pace with the rapidly evolving IoT security ecosystem. Full article

Human endogenous retroviruses (HERVs) are retroviral sequences integrated into 8% of the human genome resulting from ancient exogenous retroviral infections. Unlike endogenous retroviruses of other mammalian species, HERVs are mostly replication and retro-transposition defective, and their transcription is strictly regulated by epigenetic mechanisms in normal cells. A significant addition to the growing body of research reveals that HERVs’ aberrant activation is often associated with offsetting diseases like autoimmunity, neurodegenerative diseases, cancers, and chemoresistance. Adult T-cell leukemia/lymphoma (ATLL) is a very aggressive and chemoresistant leukemia caused by the human T-cell leukemia virus type 1 (HTLV-1). The prognosis of ATLL remains poor despite several new agents being approved in the last few years. In the present study, we compare the expression of HERV genes in CD8⁺-depleted PBMCs from HTLV-1 asymptomatic carriers and patients with acute ATLL. Herein, we show that HERVs are highly upregulated in acute ATLL. Our results further demonstrate that the oncoprotein Fra-2 binds the LTR region and activates the transcription of several HERV families, including HERV-H and HERV-K families. This raises the exciting possibility that upregulated HERV expression could be a key factor in ATLL development and the observed chemoresistance, potentially leading to new therapeutic strategies and significantly impacting the field of oncology and virology. Full article

Dehydroepiandrosterone and its sulfate are the most abundant steroids in humans. The metabolism of dehydroepiandrosterone can differ significantly depending on the organ or tissue and the subtype of steroid receptors expressed in it. For dehydroepiandrosterone, as a precursor of all steroid hormones, intracrine hormonal activity is inherent. This unique feature could be beneficial for the medicinal application, especially for the local treatment of various pathologies. At present, the clinical use of dehydroepiandrosterone is limited by its Intrarosa^® (Quebec city, QC, Canada) prasterone) 6.5 mg vaginal suppositories for the treatment of vaginal atrophy and dyspareunia, while the dehydroepiandrosterone synthetic derivatives Triplex, BNN 27, and Fluasterone have the investigational status for the treatment of various diseases. Here, we discuss the molecular targets of dehydroepiandrosterone, which open future prospects to expand its indications for use. Dehydroepiandrosterone, as an oral drug, is surmised to have promise in the treatment of osteoporosis, cachexia, and sarcopenia, as does 10% unguent for skin and muscle regeneration. Also, 5-androstenediol, a metabolite of dehydroepiandrosterone, is a promising candidate for the treatment of acute radiation syndrome and as an immunostimulating agent during radiopharmaceutical therapy. The design and synthesis of new 5-androstenediol derivatives with increased bioavailability may lead to the appearance of highly effective cytoprotectors on the pharmaceutical market. The argumentations for new clinical applications of these steroids and novel insights into their mechanisms of action are discussed. Full article

The adoption of telemedicine among the elderly is vital due to their unique healthcare needs and growing engagement with technology. This study explores the factors influencing their adoption behaviors, identifying both facilitating and inhibiting elements. While previous research has examined these factors, few have empirically assessed the simultaneous influence of barriers and enablers using a sample of elderly individuals. Using behavioral reasoning theory (BRT), this research investigates telehealth adoption behaviors of the elderly in India. A conceptual model incorporates both “reasons for” and “reasons against” adopting telehealth, capturing the nuanced dynamics of adoption behaviors. Data from 375 elderly individuals were collected to validate the model through structural equation modeling. The findings reveal that openness to change significantly enhances attitudes towards telehealth and “reasons for” adoption, influencing behaviors. This research contributes to the healthcare ecosystem by improving the understanding of telehealth adoption among the elderly. It validates the impact of openness to change alongside reasons for and against adoption, refining the understanding of behavior. By addressing impediments and leveraging facilitators, this study suggests strategies to maximize telehealth usage among the elderly, particularly those who are isolated, improving their access to medical services. Full article

We were tasked by Canada’s COVID-19 Immunity Task Force to describe severe adverse events (SAEs) associated with emergency department (ED) visits and/or hospitalizations in individuals with immune-mediated inflammatory diseases (IMIDs). At eight Canadian centres, data were collected from adults with rheumatoid arthritis (RA), axial spondyloarthritis (AxS), systemic lupus (SLE), psoriatic arthritis (PsA), and inflammatory bowel disease (IBD). We administered questionnaires, analyzing SAEs experienced within 31 days following SARS-CoV-2 vaccination. About two-thirds (63%) of 1556 participants were female; the mean age was 52.5 years. The BNT162b2 (Pfizer) vaccine was the most common, with mRNA-1273 (Moderna) being second. A total of 49% of participants had IBD, 27.4% had RA, 14.3% had PsA, 5.3% had SpA, and 4% had SLE. Twelve (0.77% of 1556 participants) SAEs leading to an ED visit or hospitalization were self-reported, occurring in 11 participants. SAEs included six (0.39% of 1556 participants) ED visits (including one due to Bell’s Palsy 31 days after first vaccination) and six (0.39% of 1556 participants) hospitalizations (including one due to Guillain-Barré syndrome 15 days after the first vaccination). Two SAEs included pericarditis, one involved SLE (considered a serious disease flare), and one involved RA. Thus, in the 31 days after SARS-CoV-2 vaccination in our IMID sample, very few serious adverse events occurred. As SARS-CoV2 continues to be a common cause of death, our findings may help optimize vaccination acceptance. Full article

High-silica adakites exhibit specific compositions, as follows: SiO₂ ≥ 56 wt.%, Al₂O₃ ≥ 15 wt.%, Y ≤ 18 ppm, Yb ≤ 1.9 ppm, K₂O/Na₂O ≥ 1, MgO < 3 wt.%, high Sr/Y (≥10), and La/Yb (>10). Devonian I-type adakitic granitoids in the northern Appalachians of New Brunswick (NB, Canada) share geochemical signatures of adakites elsewhere, i.e., SiO₂ ≥ 66.46 wt.%, Al₂O₃ > 15.47 wt.%, Y ≤ 22 ppm, Yb ≤ 2 ppm, K₂O/Na₂O > 1, MgO < 3 wt.%, Sr/Y ≥ 33 to 50, and La/Yb > 10. Remarkably, adakitic intrusions in NB, including the Blue Mountain Granodiorite Suite, Nicholas Denys, Sugar Loaf, Squaw Cap, North Dungarvan River, Magaguadavic Granite, Hampstead Granite, Tower Hill, Watson Brook Granodiorite, Rivière-Verte Porphyry, Eagle Lake Granite, Evandale Granodiorite, North Pole Stream Suite, and the McKenzie Gulch porphyry dykes all have associated Cu mineralization, similar to the Middle Devonian Cu porphyry intrusions in Mines Gaspé, Québec. Trace element data support the connection between adakite formation and slab break-off, a mechanism influencing fertility and generation of porphyry Cu systems. These adakitic rocks in NB are oxidized, and are relatively enriched in large ion lithophile elements, like Cs, Rb, Ba, and Pb, and depleted in some high field strength elements, like Y, Nb, Ta, P, and Ti; they also have Sr/Y ≥ 33 to 50, Nb/Y > 0.4, Ta/Yb > 0.3, La/Yb > 10, Ta/Yb > 0.3, Sm/Yb > 2.5, Gd/Yb > 2.0, Nb + Y < 60 ppm, and Ta + Yb < 6 ppm. These geochemical indicators point to failure of a subducting oceanic slab (slab rollback to slab break-off) in the terminal stages of subduction, as the generator of post-collisional granitoid magmatism. The break-off and separation of a dense subducted oceanic plate segment leads to upwelling asthenosphere, heat advection, and selective partial melting of the descending oceanic slab (adakite) and (or) suprasubduction zone lithospheric mantle. The resulting silica-rich adakitic magmas ascend through thickened mantle lithosphere, with minimal affect from the asthenosphere. The critical roles of transpression and transtension are highlighted in facilitating the ascent and emplacement of these fertile adakitic magmas in postsubduction zone settings. Full article

Accurate precipitation intensity forecasting is crucial for effective flood management and early warning systems. This study evaluates the performances of convolutional neural network (CNN) and long short-term memory (LSTM) models in predicting hourly precipitation intensity using data from Sainte Catherine de la Jacques Cartier station near Québec City. The models predict precipitation levels from one to six hours ahead, which are categorized into slight, moderate, heavy, and very heavy precipitation intensities. Our methodology involved gathering hourly precipitation data, defining input combinations for multistep ahead forecasting, and employing CNN and LSTM models. The performances of these models were assessed through qualitative and quantitative evaluations. The key findings reveal that the LSTM model excelled in the short-term (1HA to 2HA) and long-term (3HA to 6HA) forecasting, with higher R² (up to 0.999) and NSE values (up to 0.999), while the CNN model was more computationally efficient, with lower AICc values (e.g., −16,041.1 for 1HA). The error analysis shows that the CNN demonstrated higher precision in the heavy and very heavy categories, with a lower relative error, whereas the LSTM performed better for the slight and moderate categories. The LSTM outperformed the CNN in minor- and high-intensity events, but the CNN exhibited a better performance for significant precipitation events with shorter lead times. Overall, both models were adequate, with the LSTM providing better accuracy for extended forecasts and the CNN offering efficiency for immediate predictions, highlighting their complementary roles in enhancing early warning systems and flood management strategies. Full article

Thermostable amylases are among the most widely used and desirable enzymes in the food industry. Indeed, they guarantee faster reactions at high temperatures, enhanced substrate solubility and reduced microbial contamination and cooling costs. The objective of this work is to study the amylase activity of three strains of aerobic thermophilic bacteria isolated from the hot spring of Hammam Salhine, located in the wilaya of Skikda, Algeria. The three extracellular amylase-producing strains were subjected to the quantification of amylase activity. They presented medium to high activity, with significantly the best production for the AS1 strain with an activity of 10.62 ± 1.289 U (p > 0.05). Monitoring the kinetics of AS1 amylase activity reveals that the maximum enzymatic activity was reached after 52 h with a value of 53.665 ± 2.534 U. The maximum growth was reached after 54 h of fermentation at an OD of 0.865 ± 0.081 at 600 nm. The study of the effect of the variation in physicochemical parameters on the activity of AS1 amylase extract shows that the enzymatic activity was maximal at a temperature of 100 °C, a pH of 8.0 and in the absence of NaCl. The amylase extract of this strain showed significant thermostability at 100 °C. Full article

The rapidly increasing skin cancer rates in Canada are alarming, with current data estimating that 1/3 of Canadians will be affected in their lifetime. Thus, deeper understanding of high-risk sun exposure behaviors is needed to help counter this trend. Only limited action has been taken by federal/provincial governments to reduce skin cancer incidence. A cross-sectional survey study was conducted in Manitoba, with frequency counts, means, and percentages used to encapsulate responses. Age- and gender-adjusted odds ratios were calculated using logistic regression analyses. Our study identified worrying inadequacies in sun protective behaviors and attitudes, with the threat of such high-risk behaviors amplified by a lack of skin cancer awareness. Alarming elements were noted in participants’ sun exposure history (>65% reported a history of sunburns, >50% previously used a tanning bed, and >75% recently tanned for pleasure), beliefs and attitudes (>50% believe that they look better/healthier with a tan, and >40% believe that having a base tan is protective against further sun damage), and sun protection efforts (sun protective clothing was used <60% of the time, sunscreen was used by <50%, and there was a lack of knowledge about sunscreen characteristics in ~30% of respondents), in addition to significant differences being established between demographic subgroups (based on gender, age, skin phototype, income, and education attained). This study provides worrisome insight onto the grim landscape of sun protective behaviors and attitudes in Manitoba, which will inevitably translate into higher skin cancer rates and should serve as a call to action to promote targeted public health messaging in this jurisdiction and beyond. Full article

This study investigates the relationship between corporate ethics and the information intermediation element of public companies’ information environment. Drawing on the well-established virtue, deontological, and consequential ethical theories, we predict that higher corporate ethics standards have a positive effect on financial analysts’ behavior and earnings forecasts. Using a sample of 5276 firm-year observations from 780 publicly listed US companies, multivariate regression analyses document a significant positive association between company’s level of ethical commitment and analyst coverage and forecast accuracy. Furthermore, the results show that firms with fewer incidents of ethical misconduct are associated with higher analyst consensus. These findings hold across a battery of robustness tests and indicate that a firm’s ethical commitment enhances its corporate information environment and allows financial analysts to play a more effective intermediary role in capital markets. Full article

Nitrogen is an essential nutrient for plant functioning, photosynthesis, and metabolic activities. In terrestrial settings, nitrogen is not always sufficiently available because its basic form (N₂) must be fixed into other forms, such as nitrate and ammonium, to be usable by plants. Adding nitrogenous fertilizer to soils may provide a means of increasing forest productivity. Ammoniacal nitrogen (N-NH₃), an effluent produced during gold extraction, requires mining companies to manage its long-distance and costly transportation offsite for disposal. Applying this nitrogenous effluent, in its treated form of ammonium sulfate (ammoniacal nitrogen from mine water was converted into ammonium sulfate locally), to regional forest stands could provide a cost-effective and more environmentally sound means of managing this waste product and enhance forest productivity. Here, we conducted greenhouse- and field-based experiments to evaluate ammonium sulfate fertilization on black spruce (Picea mariana) and jack pine (Pinus banksiana) seedling growth. We assigned five treatments, varying in terms of the fertilizer concentration and presence/absence of biochar, to seedlings in greenhouse trials. We also applied various concentrations of ammonium sulfate to an 8-year-old black spruce plantation in Abitibi-Témiscamingue, Québec. We found that black spruce and jack pine seedlings experienced greater growth than the controls in terms of the stem diameter (32–44%), seedling height (21–49%), and biomass (86–154%). In the field experiment, we observed 37% greater volumetric growth in plots receiving medium-level fertilization than the control. Although nitrogen fertilization lowered the soil pH, essential nutrients increased to favor greater seedling growth. Thus, ammonium sulfate, derived from local mining effluent, appears to offer a suitable alternative for enriching nitrogen-limited boreal soils and increasing tree growth. This application could benefit both regional mining industries and forest management bodies. Full article

Laboratory flotation tests carried out using an ore sample containing Rare Earth Elements (REEs) present as monazite and bastnaesite show that the flotation of monazite is slower and yielded lower recovery than that of bastnaesite. Results show that when studying the performances of a concentration process for an REE ore, it is essential to not look only at the behavior of the individual REEs but to convert elemental assays into mineral assays to obtain the mineral’s actual response to the concentration process. The results of the laboratory flotation tests are used to calibrate a flotation simulator applied to study different circuit configurations for the concentration of the REE minerals. Indeed, it is shown that for the studied ore, two cleaning stages of a rougher concentrate are sufficient to produce a concentrate with a Total Rare Earth Oxide (TREO) grade above 40%, which is acceptable for the subsequent hydrometallurgical process. The simulation also shows that it may be feasible, if required for the hydrometallurgy step, to separate bastnaesite and monazite by taking advantage of the different flotation kinetics of the two minerals. Full article

For almost a thousand years (1090–1990), Santa Maria della Scala in Siena—arguably one of the oldest surviving hospitals in the world—opened its doors to pilgrims, travelers, the sick, the poor, and the gittati (children who were “cast off” and left on its steps). Making manifest the traditional adage of hospitality, all the guests who presented themselves there were to be welcomed as Christ himself. In this paper, I explore this broadening of the Church’s vision of its healing ministry (that is, beyond care for the sick) alongside the increasing dedication of the laity to the opera misericordiae (the works of mercy) in the late and high Middle Ages with the Ospedale di Santa Maria della Scala in Siena as a case in point. I will make reference to the mid-fifteenth century fresco cycle in the Pellegrinaio of the hospital that bears witness to its celebrated functions and speaks to how and by whom these were carried out. Full article