Dual-polarized chipless humidity sensor tag

In this letter, a miniaturized, flexible and high data dense dual-polarized chipless radio frequency identification (RFID) tag is presented. The tag is designed within a minuscule footprint of 29 × 29 mm2 and has the ability to encode 38-bit data. The tag is analyzed for flexible substrates including Kapton® HN DuPont™ and HP photopaper. The humidity sensing phenomenon is demonstrated by mapping the tag design, using silver nano-particle based conductive ink on HP photopaper substrate. It is observed that with the increasing moisture, the humidity sensing behavior is exhibited in RF range of 4.1–17.76 GHz. The low-cost, bendable and directly printable humidity sensor tag can be deployed in a number of intelligent tracking applications

Absolute quantification of priority bacteria in aquaculture using digital PCR

Modern aquaculture systems are designed for intensive rearing of fish or other species. Both land-based and offshore systems typically contain high loads of biomass and the water quality in these systems is of paramount importance for fish health and production. Microorganisms play a crucial role in removal of organic matter and nitrogen-recycling, production of toxic hydrogen sulfide (H2S), and can affect fish health directly if pathogenic for fish or exerting probiotic properties. Methods currently used in aquaculture for monitoring certain bacteria species numbers still have typically low precision, specificity, sensitivity and are time-consuming. Here, we demonstrate the use of Digital PCR as a powerful tool for absolute quantification of sulfate-reducing bacteria (SRB) and major pathogens in salmon aquaculture, Moritella viscosa, Yersinia ruckeri and Flavobacterium psychrophilum. In addition, an assay for quantification of Listeria monocytogenes, which is a human pathogen bacterium and relevant target associated with salmonid cultivation in recirculating systems and salmon processing, has been assessed. Sudden mass mortality incidents caused by H2S produced by SRB have become of major concern in closed aquaculture systems. An ultra-sensitive assay for quantification of SRB has been established using Desulfovibrio desulfuricans as reference strain. The use of TaqMan® probe technology allowed for the development of multi-plex assays capable of simultaneous quantification of these aquaculture priority bacteria. In single-plex assays, limit of detection was found to be at around 20 fg DNA for M. viscosa, Y. ruckeri and F. psychrophilum, and as low as 2 fg DNA for L. monocytogenes and D. desulfuricans.publishedVersio

Formation and fate of oil-related aggregates (ORAs) in seawater at different temperatures

In this study, the formation and fate of oil-related aggregates (ORAs) from chemically dispersed oil in seawater (SW) were investigated at different temperatures (5 °C, 13 °C, 20 °C). Experiments in natural SW alone, and in SW amended with typical marine snow constituents (phytoplankton and mineral particles), showed that the presence of algae stimulated the formation of large ORAs, while high SW temperature resulted in faster aggregate formation. The ORAs formed at 5 °C and 13 °C required mineral particles for sinking, while the aggregates also sank in the absence of mineral particles at 20°. Early in the experimental periods, oil compound accumulation in ORAs was faster than biodegradation, particularly in aggregates with algae, followed by rapid biodegradation. High abundances of bacteria associated with hydrocarbon biodegradation were determined in the ORAs, together with algae-associated bacteria, while clustering analyses showed separation between bacterial communities in experiments with oil alone and oil with algae/mineral particles.publishedVersio

Multiplex droplet digital PCR assay for detection of Flavobacterium psychrophilum and Yersinia ruckeri in Norwegian aquaculture

We report the development of ddPCR assays for single and simultaneous detection of the bacterial pathogens Flavobacterium psychrophilum and Yersinia ruckeri in water from land-based recirculation aquaculture systems (RAS), producing Atlantic salmon (Salmo salar) smolt. The method was tested and verified for use in water analyses from RAS production sites, and proved to be specific and with sensitivity 0.0011 ng DNA for F. psychrophilum and 1.24 ng for Y. ruckeri. These bacteria are important fish pathogens that have caused reoccurring salmonid infection disease in RAS. Monitoring pathogen levels in water samples could be a useful alternative surveillance strategy to evaluate operational risk assessment connected to stress factors. Water quality is essential for fish health and growth in RAS production in general, and high or increasing levels of these pathogens in the RAS water may generate an early indication of unfavourable conditions in the RAS environment, and give directions to operational actions. This approach may reduce fish mortality, reduce production loss, and offer more effective and targeted preventive measures within RAS production.publishedVersio

Early warning through video monitoring: Dissolved hydrogen sulphide (H2S) affects Atlantic salmon swimming behavior in recirculating aquaculture systems

Hydrogen sulphide (H2S) poses a major threat in marine land-based recirculating aquaculture systems (RAS) leading to acute mortality in sensitive fish species such as Atlantic salmon (Salmo salar). To date, little is known about the effects of H2S on the physiology and behavior of the species. The present study analyzed Atlantic salmon swimming behavior in response to H2S in a controlled trial. The setup consisted of two Recirculating Aquaculture Systems (RAS) in parallel. The control RAS comprised of one fish tank (800 L, 10 kg fish/m3 (≈ 70 fish)), while the exposure RAS included two fish tanks (800 L; 10 and 30 kg fish/ m3 (≈ 70 and 200 fish)). Swimming behavior was monitored via a submerged custom-built stereo camera system and an overhead surveillance camera. Fish (smolt, ≈ 114 g) were exposed once a day for 10 consecutive days to increasing H2S concentrations, from ≈ 1- up to ≈ 68 μg/L (2 μM). Continuous measurements of dissolved H2S, O2 and CO2 were taken using a real-time monitoring system. Three swimming parameters were extrapolated from video recordings using machine learning algorithms: i) speed, ii) pattern (representing whether the fish swim in a straight or zigzagging direction) and iii) dispersion (indicative of schooling behavior). The results showed that fish reacted rapidly to H2S, with a stress response characterized by faster swimming speed, erratic pattern, and loss of schooling behavior. The response was concentration-dependent, increasing linearly up to 30–40 μg/L, above which a clear threshold was observed. Notably, concentrations around 40–50 μg/L, induced significantly greater behavioral changes compared to lower concentrations, and further increases in H2S did not lead to additional changes in behavior. Swimming parameters quickly returned to basal levels, comparable to the one's prior exposure, once H2S was no longer present in the water. This study provides new insights on the sensitivity of Atlantic salmon to acute H2S exposure and highlights the potential behind the use of machine vision as an early warning tool for poor water quality in RAS.publishedVersio

Infective endocarditis in intravenous drug abusers: an update

Infective endocarditis despite advances in diagnosis remains a common cause of hospitalization, with high morbidity and mortality rates. Through literature review it is possible to conclude that polymicrobial endocarditis occurs mainly in intravenous drug abusers with predominance in the right side of the heart, often with tricuspid valve involvement. This fact can be associated with the type of drug used by the patients; therefore, knowledge of the patient's history is critical for adjustment of the therapy. It is also important to emphasize that the most common combinations of organisms in polymicrobial infective endocarditis are: Staphylococcus aureus, Streptococcus pneumonia and Pseudomonas aeruginosa, as well as mixed cultures of Candida spp. and bacteria. A better understanding of the epidemiology and associated risk factors are required in order to develop an efficient therapy, although PE studies are difficult to perform due to the rarity of cases and lack of prospective cohorts.This work was supported by Portuguese Foundation for Science and Technology (FCT) through the grants SFRH/BPD/47693/2008, SFRH/BPD/20987/2004 and SFRH/BPD/72632/2010 attributed to Claudia Sousa, Claudia Botelho and Diana Rodrigues, respectively

Recent developments in recirculating aquaculture systems: a review

This article presents the recent advancements in recirculating aquaculture systems (RAS). The review explores new developments and potential future breakthroughs in RAS systems across leading countries. It highlights technical and technological advancement in plant management aimed at improving water quality, production efficiency, and animal welfare. A significant aspect of recent progress is the integration of artificial intelligence (AI), which is being used to optimize system performance, enhance monitoring, and support more precise and predictive management strategies. The review also addresses advancements in pathogen control and the prevention of disease outbreaks. Specific case studies of cutting-edge RAS systems from different parts of the world are discussed. The review also investigates how the improvements in RAS technology can help mitigate environmental impact. Finally, the paper focuses on advancements in the production of six fish species farmed in Europe, namely Atlantic salmon (Salmo salar), European seabass (Dicentrarchus labrax), gilthead seabream (Sparus aurata), yellowtail kingfish (Seriola lalandi), arctic charr (Salvelinus alpinus), and rainbow trout (Oncorhynchus mykiss). This review is part of the ERA-NET BlueBio cofound-funded project titled “Optimizing land-based fish production in next generation digital recirculating aquaculture systems,” which is focusing on the above-mentioned fish species

Analysis of Compound Synergy in High-Throughput Cellular Screens by Population-Based Lifetime Modeling

Despite the successful introduction of potent anti-cancer therapeutics, most of these drugs lead to only modest tumor-shrinkage or transient responses, followed by re-growth of tumors. Combining different compounds has resulted in enhanced tumor control and prolonged survival. However, methods querying the efficacy of such combinations have been hampered by limited scalability, analytical resolution, statistical feasibility, or a combination thereof. We have developed a theoretical framework modeling cellular viability as a stochastic lifetime process to determine synergistic compound combinations from high-throughput cellular screens. We apply our method to data derived from chemical perturbations of 65 cancer cell lines with two inhibitors. Our analysis revealed synergy for the combination of both compounds in subsets of cell lines. By contrast, in cell lines in which inhibition of one of both targets was sufficient to induce cell death, no synergy was detected, compatible with the topology of the oncogenically activated signaling network. In summary, we provide a tool for the measurement of synergy strength for combination perturbation experiments that might help define pathway topologies and direct clinical trials