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Energy is the fundamental currency of the universe, driving the mechanisms of natural and artificial systems alike. From the molecular bonds in our bodies to the colossal fusion reactions within stars, every process hinges on the availability and ability of energy transmission. The capacity to harness energy has allowed human civilization to develop in the way we knowand understand it today. From harnessing fire to the construction of aqueducts to the monumental leap of the Industrial Revolution. These innovations are the essence of humanity’s historicalstrides in developing our current societies.However, just as every currency transaction incurs fees, our quest for energy comes at a cost. Our fossil fuel-powered world, while spurring unprecedented growth has also introduced not a few environmental costs.As we seek more efficient and sustainable ways to harness energy, we must recognize and address the challenges these solutions bring, balancing innovation with environmental stewardship.

Kishorekumar, M.; Jayakumar, N.; Jawahar, P.; Neethiselvan, N.; Padmavathy, P.; Karuppasamy, K.; Sudhan, C., and Chandravanshi, S., 2024. Length–weight relationship of nine elasmobranch species landed along the south Tamil Nadu coast, India. Journal of Coastal Research, 40(6), 1160–1165. Charlotte (North Carolina), ISSN 0749-0208. The present study was conducted to establish the length–weight relationship of nine elasmobranch species from the coast of southern Tamil Nadu, India. In total, 2686 specimens of nine species of elasmobranchs belonging to five orders, seven families, and eight genera were collected fortnightly from commercial catches with different fishing gear, such as trawl net, gill net, and deep-sea longline, from the Thoothukudi, Mandapam, and Thengapattanam fishing harbors from December 2022 to November 2023. The results showed that most species exhibited positive allometric growth and that values of b were within the expected range of 2.5 to 3.5. The maximum b value (3.17) was observed for male Pateobatis bleekeri. The total length–weight relationship or disc width–weight relationship showed good fit with r2 values, varying from 0.8374 to 0.9969. The calculated b values in the current study showed that all males, females, and combined sexes of P. bleekeri, Aetobatus ocellatus, and Acroteriobatus variegatus showed negative allometric growth (b < 3). In the study, a new maximum total length is reported for P. bleekeri, and this study provides the first estimate,, of the length–weight relationship for the critically endangered species A. variegatus. The study provides baseline information for biological studies, stock assessment and management, and conservation of elasmobranch resources in a sustainable way along this coast. [ABSTRACT FROM AUTHOR]

Over one third of sharks, rays and chimaeras (chondrichthyans) are threatened with extinction globally. In the Mediterranean Sea, more than half of chondrichthyan species face this risk, although a variety of international, regional, and national rules and regulations apply directly and indirectly targeting management and conservation for these species. In this work, we provide an overview of relevant legislation and policies in the region, which regulate, inter alia, commercial fisheries, while highlighting through cases studies how implementation in practice at national level looks like. Horizontal gaps and inconsistencies that hinder chondrichthyan management in the region are also illustrated. Furthermore, we present recommendations for improvement and additional tools that can be used, even if not originally or explicitly targeting chondrichthyans, for improving the management of these taxa in the Mediterranean. [ABSTRACT FROM AUTHOR]

Abstract Age data are essential for estimating life history parameters and are thus critical for population assessment, management, and conservation. Traditional vertebrae-based age estimation in elasmobranchs can be costly, time intensive, of low accuracy, and is by necessity lethal. Herein, epigenetic clocks were developed for an elasmobranch, the cownose ray (Rhinoptera bonasus), using aquarium-born individuals (n = 42) with known dates of birth (age range: 7−7,878 days or 0−21 years) and two tissue types (fin clips and whole blood) that can be sampled in a relatively non-invasive manner. Enzymatically-converted restriction site-associated DNA sequencing (ECrad-seq) was used to identify CpG sites that exhibited age-correlated DNA methylation. The epigenetic clocks developed were highly accurate (mean absolute error, MAE, < 0.75 years) and precise (R 2 > 0.98). Age-associated CpG sites were identified across tissues, and a multi-tissue clock was also highly accurate (MAE 22 years were predicted to be 22.10−23.49 years old. Overall, the results have important implications for future epigenetic clock development and noninvasive age estimation in elasmobranchs.

A fast and robust two‐point ray tracing method was developed for layered vertical transversely isotropic media with strong anisotropy. Utilizing the Christoffel slowness equation, a novel generalized dimensionless ray parameter, qx${{q}_x}$, modified from the ray parameter (horizontal slowness), was proposed to efficiently and simultaneously determine the ray paths and travel times for direct and reflected quasi‐P, quasi‐SV and quasi‐SH waves. The Newton optimization algorithm was employed to solve the nonlinear offset equation accurately, resulting in rapid convergence to the true value. The inferred analytical equations show that the generalized ray parameter stabilizes the inversion process at large offsets. Additionally, a piecewise function was introduced to enhance the initial value estimation and calculation efficiency. The numerical results demonstrate that this novel approach can reduce the iteration error to 10−10 m in less than three iterations. Monte Carlo simulations further validated the effectiveness of the qx${{q}_x}$ method for inferring the true ray paths at various offsets within complex velocity models. Furthermore, the qx${{q}_x}$ method can address the triplication issue in quasi‐SV waves and exhibit robustness in strong‐layered vertical transversely isotropic media. [ABSTRACT FROM AUTHOR]

Hardwoods are complex heterogeneous and orthotropic structures that have evolved to the present day, adapting to successive climate episodes to prosper on Earth. Attributing a specific functionality to individual hardwood elements is difficult because of their interconnection in this heterogeneous three-dimensional network. However, tree physiology research is helping to enhance knowledge in this field. This work is a short review of the possible functionalities of hardwood elements, in some cases supported by experimentation and in others by comparative anatomy. It is intended for students or researchers starting out in the world of hardwood anatomy to aid their understanding of the functionality of hardwood elements. [ABSTRACT FROM AUTHOR]

Marine vibrators represent an alternative seismic source technology that could come to market in the near future. A key challenge related to marine vibrator seismic data is the effect that phase dispersion from source motion has on the signal during transmission. As such, the recorded moving vibrator data will benefit from being phase corrected, so that the data appear as if they had been shot with a stationary source. This transformation is called the source motion correction. Previous source motion corrections used either specific dephasing operators for specific sweep types or pre‐correlation methods for any sweep type. A source motion correction dephasing operator has been derived, demonstrated and applied to real seismic data collected during a Marine Vibrator Joint Industry Project field trial of an array of marine vibrators. This dephasing operator has been made more general so that any strictly monotonic sweep through time may be used for this correction regardless of sweep type (e.g. linear or exponential). Moreover, the correction uses the pilot sweep as a direct input, measuring from it, the instantaneous frequency which can then be used to build the dephasing operator. This new more general form brings two key advantages over previous dephasing operator corrections: (1) Non‐analytically defined sweeps can now be source motion corrected, and (2) even when an analytically defined sweep (e.g. linear) is used, the transmitted sweep from the marine vibrator can vary from the theoretical input sweep; this correction can account for these changes. Furthermore, given that this source motion correction is a dephasing operator, it can be applied pre‐ or post‐correlation of the raw data with the pilot sweep, thus allowing greater flexibility in the processing. Lastly, some previously derived source motion corrections based on dephasing operators contained errors in their derivation; this new derivation addresses these errors resulting in an improved correction. [ABSTRACT FROM AUTHOR]

Elasmobranchs (sharks and rays) are the most threatened marine vertebrates, particularly in tropical and subtropical areas. Their population status is often poorly understood due to insufficient information. Despite reportedly harbouring critical elasmobranch habitats, the Banc d'Arguin National Park (PNBA) in Mauritania lacks comprehensive and updated information on the diversity of elasmobranch species in the area. We developed a baseline inventory based on morphological and molecular identification and metabarcoding. DNA barcoding of tissue samples from elasmobranch processing sites and freshly sampled specimens was used to build a genetic reference database of local elasmobranch species. The richness and diversity of species in the PNBA were described via metabarcoding of seawater eDNA samples using an elasmobranch-specific assay and our reference database. We detected 27 species, including 12 new species records for the PNBA. We further uncover potentially undescribed species of Gymnura and Torpedo, while taxonomic corrections are noted for previously reported species. In particular, the reportedly abundant Mustelus mustelus was absent from tissue and eDNA samples, while M. punctulatus was detected instead. Taxa that have anecdotally become regionally extinct or rare (e.g., sawfishes, wedgefishes, lemon sharks) were not detected, highlighting local species diversity shifts within the last few decades. Results show that 67.9% of elasmobranch species in the PNBA are threatened with extinction according to the IUCN Red List of Threatened Species. This study emphasises the importance of taxonomic identification in support of species management and provides a baseline to inform future studies and conservation measures to avoid further species losses. [ABSTRACT FROM AUTHOR]

To achieve sustainable shark fisheries, it is key to understand not only the biological drivers and environmental consequences of overfishing, but also the social and economic drivers of fisher behavior. The extinction risk of sharks is highest in coastal tropical waters, where small‐scale fisheries are most prevalent. Small‐scale fisheries provide a critical source of economic and nutritional security to coastal communities, and these fishers are among the most vulnerable social and economic groups. We used Kenya's and Zanzibar's small‐scale shark fisheries, which are illustrative of the many data‐poor, small‐scale shark fisheries worldwide, as case studies to explore the relationship between extinction risk and the economic and nutritional value of sharks. To achieve this, we combined existing data on shark landings, extinction risk, and nutritional value with sales data at 16 key landing sites and information from interviews with 476 fishers. Shark fisheries were an important source of economic and nutritional security, valued at >US$4 million annually and providing enough nutrition for tens of thousands of people. Economically and nutritionally, catches were dominated by threatened species (72.7% and 64.6–89.7%, respectively). The most economically valuable species were large and slow to reproduce (e.g. mobulid rays, wedgefish, and bull, silky, and mako sharks) and therefore more likely to be threatened with extinction. Given the financial incentive and intensive fishing pressure, small‐scale fisheries are undoubtedly major contributors to the decline of threatened coastal shark species. In the absence of effective fisheries management and enforcement, we argue that within small‐scale fisheries the conditions exist for an economically incentivized feedback loop in which vulnerable fishers are driven to persistently overfish vulnerable and declining shark species. To protect these species from extinction, this feedback loop must be broken. [ABSTRACT FROM AUTHOR]

The size—and hence the age—at first maturity is a very important feature of fish and other water-breathing ectotherms (WBE), as it determines, jointly with their subsequent growth, longevity, and fecundity, the reproductive output that their life-history attempts to optimize. Here, based on the fact that gill surface area (S) is related to their weight (W) according to S ∝ Wd, with d always < 1, which causes relative oxygen supply to decline with size, and body fluids and tissues to gradually become hypercapnic and acidic, we posit that a pH "reproductive respiration threshold" (RRT) triggers the hormonal cascade leading to maturation. Previous studies showed that such a RRT exists and takes similar values in hundreds of species of bony fish and invertebrate WBE. Here, we show that the RRT is significantly lower in non-viviparous marine Chondrichthyes, as assessed based on 1622 pairs of length at first maturity and maximum length in 918 species of Chondrichthyes, i.e., 414 species of sharks, 470 of rays, and 34 of chimaera. The hypothesis that the high concentration of urea retained for the purpose of osmoregulation by marine Chondrichthyes is the reason for this difference was tested through comparison of marine, euryhaline, and freshwater rays, which retain differing urea concentrations. We found that in rays, decreasing urea retention correlates with increasing RRT, with freshwater rays approaching the values occurring in bony fish. Finally, we found that viviparity, which increases the oxygen demand of pregnant Chondrichthyes, induces higher RRT, thus again linking respiration and the attainment of first maturity. These results support the existence of critical maturation RRT, while also suggesting a role for urea that was previously undocumented. [ABSTRACT FROM AUTHOR]

Anatomical features that underlie tree functions in E. angolense and E. cylindricum were investigated in this study. Mechanical, hydraulic and storage functions, including their presumed dominance in either stem and root region were also stated. This study was carried out at Forestry Research Institute of Nigeria (FRIN), Jericho hills, Ibadan. Stem and root wood cores were obtained by non-destructive sampling from tree stem at breast height of 1.35m, while root samples were obtained from the lateral root of each mature tree at a radius of about 100cm to the trunk. Sectioning of sample materials was performed using a Reichert microtome sliding machine. Maceration was done by preparing wood samples into slivers in equal volume of glacial acetic acid (ethanoic acid) and hydrogen peroxide (1:1) in two hours (2hrs) at a temperature of 100°C. Microscopic investigations and measurements of wood cells were performed using a Zeis light microscope (Standard 25), and all data analyses were completed using R statistical software (R Core Team 2016). Results showed average values of vessel parameters, fibre parameters were higher at the stem region than at the root region in both wood species, while ray dimensions were higher at the root regions than at the stem regions of the two species. This suggested that the two wood species would rather trade off mechanical and hydraulic functions for storage function at the root region in order to be efficient in water conduction as large vessels will bring about embolism. Therefore, vessels were wider in the stem regions than in the root regions of the two wood species; rays were also wider in the root than in the stem, hence, this study revealed that storage functions could be dominance in the root region rather than the stem region of both E. angolense and E. cylindricum. [ABSTRACT FROM AUTHOR]

The goal of this article is to examine the behavior of reinforced concrete (RC) rays that strengthen superficially the basalt fiber-reinforced polymer (BFRP) fabrics. We found out that one ray without BFRP and seven rays enveloped within numerous lay-up arrangements. The importance of the study is to improve the flexural capacity of rays, using fiber-reinforced polymer procedure and examine the over-reinforcement technique.

Basswood samples were exposed to oxygen glow-discharge plasmas for 30 min, and etching of radial and tangential longitudinal surfaces was measured. It was hypothesized that there would be a positive correlation between etching and plasma energy, and differential etching of wood surfaces because of variation in the microstructure and chemical composition of different woody tissues. Etching at the surface of basswood samples was examined using profilometry. Light and scanning electron microscopy were used to examine the microstructure of samples exposed to plasma. There was a large effect of plasma energy on etching of basswood surfaces, and radial surfaces were etched to a greater extent than tangential surfaces. However, rays at radial surfaces were more resistant to etching than fibers, resulting in greater variation in the etching of radial versus tangential surfaces. The same phenomenon occurred at radial surfaces of balsa wood, jelutong and New Zealand white pine subjected to plasma etching. The possible reasons for the greater resistance of rays to plasma etching are explored, and it is suggested that such differential etching of wood surfaces may impose a limitation on the use of plasma to precisely etch functional patterns at wood surfaces (raised pillars, grooves), as has been done with other materials. [ABSTRACT FROM AUTHOR]

Elasmobranch population declines due to human impacts have been documented at a global scale, having impacts on the functioning and structure of marine ecosystems. This situation leads to an international focus on the conservation of their populations and a key step in the management and conservation of elasmobranch populations is to understand their trophic ecology. Here, by using stable isotopes analysis, we investigated the trophic relationships, trophic niche breadth, and trophic redundancy among 21 batoids and 12 sharks inhabiting the Persian Gulf and Gulf of Oman, two productive areas of the Arabian Sea considered global elasmobranch hotspots. Isotopic results revealed differences in the trophic niche and trophic position among the elasmobranch sampled at species and at family level. For example, the batoids of the family Torpedinidae and the sharks of the family Triakidae occupied higher trophic positions and the family Glaucostegidae showed a lower trophic niche width, whereas the batoids of the family Myliobatidae or Gymnuridae, in overall, showed lower higher trophic niche width, reflecting the trophic habits described for most of the sampled species. We also provided some insights into the ecology of poorly known species, especially relevant for those that are endangered at a global or regional scale. In conclusion, we provide new information about the trophic ecology among batoids and sharks inhabiting the Persian Gulf and Gulf of Oman. This information is highly useful to study the consequences of future changes on their feeding preferences due to natural or human-related factors. [ABSTRACT FROM AUTHOR]

Simple Summary: Fungal diseases, despite their low incidence in fish, appear to be lethal in many teleost and elasmobranch species. There are many fungi involved, including Paecilomyces spp., Exophiala spp. and Fusarium spp., among the most frequently diagnosed. Fungal diseases in elasmobranchs have been documented in animals under human care in aquariums since 1980. Most cases have resulted in high mortality due to a lack of information concerning the treatment and medical and environmental management of mycoses in these species. Antifungal drugs are frequently prescribed to improve clinical signs or lesions in animals affected by fungal infections. Azole agents appear to be the most effective antifungals in the treatment of systemic fungal infections. However, more evidence concerning the use of these drugs in elasmobranchs is needed. Introduction: Elasmobranchs currently constitute an important part of the animal collection of many aquariums worldwide. Their maintenance under human care has allowed us to describe and identify new pathogens and diseases affecting them, as well as to determine different treatments for these diseases. Great advances in elasmobranch husbandry have been developed. Methods: A search was performed on scientific databases as PubMed and other specialized sources (IAAAM archive). Results: Little information on pharmacotherapeutics is available in this taxonomic group, and treatments lack a scientific base and instead are frequently dependent on empirical knowledge. Pharmacokinetic studies are the first step to determining therapeutic protocols that are safe and effective. The available bibliography shows that a majority of the mycoses recorded in cartilaginous fish are severe, aggravated by the fact that the antifungal treatments administered, following the guidelines used for teleost species, are ineffective in elasmobranchs. Azoles appear to be a promising group of antifungals for use in treating systemic mycoses in sharks and rays. Conclusions: Based on the findings of this review, it is essential to investigate the pharmacokinetics of the different antifungals in these species in order to provide therapeutic options for fungal infections in cartilaginous fish. [ABSTRACT FROM AUTHOR]

Solar Power Plant (PLTS) absorbs solar energy and is adjusted to the change in circulation from 06.00 in the morning to 17.00 in the afternoon. This requires adjustment to the installation of a solar power plant so that energy capture can be optimal; this adjustment uses a sunlight capture tool called Suntracker. The main tools are in the form of movers, timers and work steps that can be dragged. Based on the testing results and discussion of the overall design of solar trackers, namely. The highest current measurement results in stationary solar cells (static) occur at 11.00 WIB, which is 0.23 A. The highest current measurement results on solar trackers also occur at 10.00 WIB, 0.25 A. The highest voltage measurement in stationary solar cells occurs at 10.00 WIB, which is 14.2 volts. Moreover, the highest voltage measurement results on the solar tracker occurred at 10.00 WIB, which is 20.3 volts. [ABSTRACT FROM AUTHOR]

Methods for calculating the special function of wave catastrophe B4 and its first derivatives, which describe edge focusing of the caustic-tip type with an edge, are studied. The caustic and ray structures of this singularity are constructed. The characteristic amplitude–phase sections of the special function and its derivatives are calculated. The method of rotation of the integration contour and the method of ordinary differential equations are considered and compared both in terms of accuracy and speed. It is shown that the method of ordinary differential equations works stably in the region of negative values of the first two parameters of the special function, and the method of rotation of the integration contour exhibits stability in the region of positive values. Thus, the approaches are complementary. However, the calculation time for the method of ordinary differential equations is an order of magnitude less than the time for the method of rotation of the integration contour. [ABSTRACT FROM AUTHOR]

This contribution describes the acquisition and trigger system for the HEPD-02 calorimeter that will be used onboard the CSES-02 satellite for the CSES/Limadou mission. This mission arises from the collaboration between the Chinese Space Agency (CNSA) and the Italian Space Agency (ASI) and plans the realization of a constellation of satellites which will monitor ionospheric parameters supposed to be related to earthquakes. It will also monitor the solar activity and the interaction with the magnetosphere and will study the cosmic rays in low energy ranges, extending data from PAMELA and AMS. The CSES-02 satellite will be equipped with various instruments, including the High-Energy Particle Detector (HEPD-02), which was designed to measure the energy of particles coming from Van Allen belts. Signals from the HEPD-02 are acquired and digitized by an electronic board that also produces the trigger for the experiment. A new generation ASIC (CITIROC) for the amplification, shaping and memorization of signals from PMTs will be used on this board. The new ASIC allows the use of the peak detector feature, optimizing the acquisition of signals with different temporal characteristics. Along with this, new algorithms for trigger generation have been developed, providing trigger pre-scaling, concurrent trigger masks and Gamma Ray Burst detection. Using pre-scaled concurrent triggers will allow the study of very sensitive regions of a satellite's orbit such as the South Atlantic Anomaly and polar regions and to detect rare events such as GRBs while still monitoring particle bursts. In this contribution, the progress status of this work will be presented along with the measurements and tests made to finalize the flight model of the board. [ABSTRACT FROM AUTHOR]

This paper explores new approaches to the application and creation of digital media in the context of the rapid development of artificial intelligence technology, with a particular focus on virtual reality interaction. The study utilizes the spatial distance of the enclosing spheres in the hybrid hierarchical enclosing box and the characteristic of non-intersection between the enclosing boxes for collision detection, and the collision information returned by the rays is analyzed in depth. Meanwhile, the intersection test method is used to improve the efficiency of collision detection. And a subjective evaluation of 10 users’ experience in virtual reality art interaction was conducted. The results showed that the system was highly rated in accuracy (average score of 8.39), but rated lower in simplicity (average score of 4.28). There was a positive relationship between the user’s eye gaze duration and the number of interruptions and misoperations in art interactions. At an eye gaze duration of 0.2 seconds, half of the users did not experience interaction interruptions; when the gaze duration increased to 1.2 seconds, all users had no interruptions. This paper provides a practical reference case for using AI technology in digital media applications and creation, especially in enhancing the accuracy and efficiency of virtual reality interactions.

In this review of the behavioural patterns of chondrichthyan fishes, we have strived to produce a comprehensive catalogue of events and states and develop standardized terminology. Hence, actions that are slightly different, will be pooled under inclusive titles. Those used by different investigators are included in quotations within the textual descriptions of the motor patterns. This standardized ethogram will ideally lead to an increase in inter-observer reliability, giving researchers more confidence when reading colleagues' papers that report behaviours that appear similar to theirs despite being described for different species. The descriptions are presented under the following categories: (1) maintenance (2) courtship (3) filter feeding (4) scavenging (5) predation (6) sociality (7) aggression and (8) defence. The many actions are illustrated by line drawings and photographs in composite figures with an attempt to provide an example of each action for a chimaera, shark, and ray. The diversity of patterns is evident from this ethogram, consistent with observation that the brain-to-body mass ratios of cartilaginous fishes are greater than a third of the bird species and greater than those for some mammalian species. The major impetus for assembling this ethogram is to demonstrate the diversity of behaviours exhibited by members of the Chondrichthyes and to dispel the apocryphal belief that members of this taxon are 'simple feeding machines'. [ABSTRACT FROM AUTHOR]

Abstract—The transition from the traditional representation of the wave field in the vertical section of an underwater sound channel as a function of depth and time to the distribution of this field in the 3D phase space "depth–angle–time" is considered. For this purpose, the method of coherent states developed in quantum theory is used. The meaning of the proposed transition is that the field intensity distribution in the specified phase space is less sensitive to sound velocity fluctuations than in the original 2D depth–time space. This fact can be used in solving inverse problems. As an example, we consider the reconstruction of the coordinates of a source in a waveguide from measurements of the field intensity distribution of this source in phase space. [ABSTRACT FROM AUTHOR]

Our knowledge of sawfishes remains scant for Latin America. Pristis pristis (largetooth sawfish) and Pristis pectinata (smalltooth sawfish) are critically endangered. In the Yucatán Peninsula (YP), P. pristis and P. pectinata inhabit coastal landscapes.A total of 290 surveys of fishers' local ecological knowledge (LEK), including a geospatial component, were collected; 74 literature sources and available archaeological data for the region were reviewed.Interdisciplinary results show the following: the common past presence of sawfishes, their cultural significance for coastal societies, and the contemporary absence of sawfishes in coastal areas where they existed historically; sightings of juveniles were only documented by elder fishers, and only two recent narratives mention sawfishes caught incidentally 5 years ago.Geospatial results provide evidence for 52 geographic sites where sawfishes were common in the YP.Results support the development of research methodologies to study human–nature interactions integrating LEK. This matters in the YP, where sociocultural values and landscapes have changed rapidly through increasing tourism development and human overcrowding.The results can help conservation managers understand the past presence and contemporary loss of sawfishes, and their habitat, and contribute to understanding the defaunation of megafauna in the YP through time. This is critical for tourism and fishery ecosystem services on which communities of the YP rely for their economies. [ABSTRACT FROM AUTHOR]

The wave-impacted waters off exposed sandy beaches support marine megafauna, including dolphins, whales, sharks, rays and turtles. To characterise variation in megafaunal assemblages in this challenging habitat, we used drone-based remote sensing to survey marine megafauna off 23 beaches along 1050 km of the New South Wales (NSW, Australia) coast from 2017 to 2020. The surveys occurred from September to May and included 17,085 drone flights, with megafaunal abundances standardised by flight hours. In total, we identified 3838 individual animals from 16 taxa, although no megafauna was observed off 5 of the 23 beaches surveyed. Bottlenose dolphins were the most commonly sighted taxa and accounted for 82.3% of total megafaunal abundance. Cownose (6.7%) and eagle (3.4%) rays were the next most abundant taxa, with potentially dangerous sharks being rarely sighted (<1% of total megafauna). The megafaunal assemblages off wave-exposed beaches in northern NSW significantly differed from those in the central region, whereas the assemblages off the central region and southern NSW did not differ significantly. Wave exposure and water temperature were the best predictors of megafaunal assemblage structure. The richness of marine megafauna off ocean beaches was significantly greater in northern than southern NSW, and turtles were only observed off beaches in the northern region. However, variation in megafaunal richness, as well as the abundances of total megafauna, dolphins, rays, sharks and turtles were not significantly explained by water temperature, wave height, distance to estuary, or proximity to the nearest reef. Overall, drone-based surveys determined that megafaunal assemblages off wave-exposed beaches are characterised by sparse individuals or small groups of sharks, turtles and rays, punctuated by occasional large aggregations of dolphins, cownose rays and schooling sharks. The exception to this pattern was bottlenose dolphins, which routinely patrolled some beaches in northern NSW. [ABSTRACT FROM AUTHOR]

Summary: A recurring motif of Carlquist's work is the identification of traits typical for primary xylem of angiosperms as a whole, but found in the secondary xylem of certain species. These traits together make up the 'Carlquistian syndrome'. Convergent occurrence of the syndrome in plants with similar habits suggests its adaptive value. One of its components — raylessness — has received the most attention and has been regarded as the result of selection favouring stem rigidity. However, how raylessness (or the Carlquistian syndrome in general) arises ontogenetically has been little studied. Here, we report that in some plants secondary xylem resembles primary xylem of the same individual, and not that of angiosperms in general as observed by Carlquist. Based on literature and microslide surveys, we identified this prolongation of primary xylem patterns into secondary xylem in most major clades of non-monocot angiosperms, including magnoliids, asterids and rosids. [ABSTRACT FROM AUTHOR]

Summary: Storage of nutrients and water are important functions of secondary xylem that have received much attention lately. In most of these studies, the storage role has been attributed to the fraction and arrangement of ray and axial parenchyma. However, in the current article, we show that in many species, especially those from tropical and subtropical regions (where most of the world's plant species are found), nutrient and water storage is carried out by living imperforate tracheary elements (ITEs), colloquially termed "living fibres". The occurrence of living fibres has been long recognized by anatomists, and especially emphasized in the work of Sherwin Carlquist. In spite of this, living fibres have remained largely unacknowledged by most plant physiologists and ecologists. To raise awareness about the existence of living fibres and to celebrate the illuminating work of Sherwin Carlquist, we summarize our current understanding of the structure, function, and occurrence of living fibres and emphasize that they should receive more attention when studying storage in wood. [ABSTRACT FROM AUTHOR]

Considerable research exists on the life history traits, evolutionary history, and environmental factors that shape the population genetic structure of marine organisms, including sharks and rays. Conservation concerns are particularly strong for this group as they are highly susceptible to anthropogenic stressors due to a combination of life history traits including late maturity and low fecundity. Here, we provide a review and synthesis of the global phylogeography of sharks and rays. We examined existing data for 40 species of sharks belonging to 17 genera and 19 species of rays belonging to 11 genera. Median joining haplotype networks were constructed for each species for the mtDNA cytochrome C oxidase subunit I (COI), and an Analysis of Molecular Variance (AMOVA) was conducted to understand patterns of genetic diversity and structure across the three major ocean basins--the Indian, Atlantic and Pacific Oceans. Haplotype networks showed very shallow coalescence in most species, a finding previously reported for marine teleosts. Star topologies were predominant among sharks while complex mutational topologies predominated among rays, a finding we attribute to extremely limited dispersal in the early life history of rays. Population structuring varied amongst species groups, apparently due to differences in life history traits including reproductive philopatry, site fidelity, pelagic habitat, migratory habits, and dispersal ability. In comparison to reef-associated and demersal species, pelagic and semi pelagic species showed lower levels of structure between and within ocean basins. As expected, there is variation between taxa and groups, but there are also some broad patterns that can guide management and conservation strategies. [ABSTRACT FROM AUTHOR]

Estuarine and coastal ecosystems act as important habitats for several elasmobranchs. However, little is known about the species, spatial and temporal distribution patterns, and variability in abundance of elasmobranchs occurring in estuaries along the Indian coast. Fishery surveys in Zuari, a tropical estuary on the Arabian Sea coast of India during 2018–2019, yielded 727 individuals of 18 elasmobranchs elasmobranch species from seven families in the small-scale fisheries. The size composition showed that juvenile and sub-adults' life stages dominated the catch. Most taxa were infrequent in the catch and the top five abundant species were Scoliodon laticaudus, Rhizoprionodon acutus, Chiloscyllium arabicum, Pastinachus sephen, Glaucostegus granulatus, and Himantura uarnak, which shared 70% of the total numerical records. The species richness and diversity of elasmobranchs were the highest in the lower reach with a salinity range (25–34 psu) and estuarine mouth width (3–5 km), whereas evenness was maximum in the upper reaches with a salinity range (20–25 psu) and estuarine mouth width (1–2 km). The numerical abundance and diversity of elasmobranchs were markedly high during dry saline phase (673) and very low counts (54) during the wet phase. Thus, a clear seasonal difference was evident in the distribution of elasmobranchs in Zuari estuary. The ecological guild of elasmobranchs in the Zuari estuarine environments can be broadly categorised into non-marine transients (five species) and others as euryhaline generalists (nine species) and estuarine generalists (four species). Spatial maps show the distribution of elasmobranch species in the estuary followed a strong salinity gradient and the lower reaches showed the highest abundance. The study highlighted the importance of conserving the estuaries of the Indian Ocean region which act as shark habitats and are being impacted by urbanisation and climate change, further provides insights into spatial estuarine use by elasmobranchs. [ABSTRACT FROM AUTHOR]

More than half of the Mediterranean sharks and rays are threatened by fishing exploitation. However, population assessments are limited by the scarcity of specific data on fishing catches. In this study, we assessed temporal trends of the indicators developed within the European Marine Strategy Framework Directive over the last two decades in order to assess the conservation status of demersal sharks and batoids in the Balearic Islands, which represent an important fraction of the bycatch of bottom trawling in this area. On the basis of a georeferenced, fishery-independent dataset of 19 species of elasmobranchs, we analyzed 20 year time series (2002–2021) of nine indicators regarding area distribution, population size, population status, and community structure. Between 30% and 50% of the elasmobranch species and functional groups showed increasing trends in distribution area and population size. This was especially true for batoids, whereas the distribution area and population size of most sharks remained stable over the study period. The remaining indicators showed stability or, in some cases, variable trends. Only in one case did we find a negative trend sustained all along the time series (i.e., the proportion of R. radula large individuals in relation to the reference period). Overall, our results suggest that the populations of elasmobranchs from the Balearic Islands show stable or recovery trends, mainly in terms of distribution area and density. However, it remains elusive whether this community can recover to the levels of more than half a century ago, before the development of the bottom trawl fishery, or whether this apparent current steady state should be interpreted as a new equilibrium. [ABSTRACT FROM AUTHOR]

Conservation and management of chondrichthyans are becoming increasingly important, as many species are particularly vulnerable to fishing activities, primarily as bycatch, which leads to incomplete catch reporting, potentially hiding the impact on these organisms. Here, we aimed at implementing an eDNA metabarcoding approach to reconstruct shark and ray bycatch composition from 24 hauls of a bottom trawl fishing vessel in the central Mediterranean. eDNA samples were collected through the passive filtration of seawater by simple gauze rolls encapsulated in a probe (the "metaprobe"), which already showed great efficiency in detecting marine species from trace DNA in the environment. To improve molecular taxonomic detection, we enhanced the 12S target marker reference library by generating sequences for 14 Mediterranean chondrichthyans previously unrepresented in public repositories. DNA metabarcoding data correctly identifies almost all bycaught species and detected five additional species not present in the net, highlighting the potential of this method to detect rare species. Chondrichthyan diversity showed significant association with some key environmental variables (depth and distance from the coast) and the fishing effort, which are known to influence demersal communities. As DNA metabarcoding progressively positions itself as a staple tool for biodiversity monitoring, we expect that its melding with opportunistic, fishery-dependent surveys could reveal additional distribution features of threatened and elusive megafauna. [ABSTRACT FROM AUTHOR]

Understanding how elasmobranchs respond to stressors is imperative so that effective measures to reduce mortality be employed, whether in commercially captured animals or sharks and rays maintained in human care. Currently, reflex action mortality predictors (RAMPs) are the most reliable proxies to indicate an animal's condition state, commonly employed for both teleost and elasmobranchs. As our understanding of mortality predictors is evolving, is it necessary that traditional indicators be constantly reviewed and new proxies proposed, in order to improve the tools available for the best possible evaluation of a stressed individual. In this context, this review aimed to compile data on behavioral and visual proxies, along with the proposition of new proxies to guide professionals and assist them in identifying signs associated with alarming situations that might potentially result in the death of highly stressed individuals or sub-lethal effects at population level (migration, reproduction) that may seriously compromise the success of release measures. [ABSTRACT FROM AUTHOR]

The study was conducted at the Forest College and Research Institute, Mettupalayam, during 2019-2022, to explore new alternative pulpwood species with good paper-making potential. The samples were collected from seeds origin Pterygota alata which were farm grown in Pollachi, India. A total of 12 trees were removed with a specification of four different girth classes (30-45, 45-90, 120-150, 150-180 cm), from that 6 samples were collected from three different radial positions (pith, middle, and periphery) with the dimension of 2x2x2 cm³. Then samples were subjected to microtomy, maceration, and optical analysis. Fibre, vessel, and ray anatomy were studied in the current investigation. Results revealed that the maximum value of fibre length (1458.96 ±3.47 μm), fibre diameter (25.50±1.29 μm), vessel diameter (74.94±0.13 μm), vessels area (47723.47±359.67 μm²), ray height (1731.89±46.89 μm) ray width (165.07±1.41 μm) and ray frequency (5.51±0.02 ray/mm²) were identified at the peripheral region at the girth of 150-180 and 120-150 cm. The study suggested that Pterygota alata could be the prominent alternate species for pulp and paper production. [ABSTRACT FROM AUTHOR]

Overfishing and habitat degradation are major threats to marine megafauna worldwide. Marine protected areas (MPAs) are effective spatial conservation tools for reducing anthropogenic pressures on threatened species but their benefits for megafauna are still debated. While the effects of MPAs on species abundances are widely reported, few studies have simultaneously investigated the confounding effect of habitat.This study aimed at disentangling the effects of coral reef habitat and spatial protection on megafauna densities in a shallow lagoon partly covered by a no‐take MPA in New Caledonia (South‐west Pacific).Twenty replicates of aerial‐video surveys (representing 17 h of videos) were conducted during a 5‐month period to estimate and map the densities of five megafauna taxa (dugongs, sea turtles, sharks, Dasyatidae rays and Myliobatidae rays). A permutational multivariate analysis of variance was then applied to assess and disentangle the effects of coral reef habitat obtained from high‐resolution satellite imagery and spatial protection on megafauna taxa densities.The analysis revealed a significant effect of protection for sharks and Myliobatidae, with observed densities respectively 9 and 3 times higher inside the MPA compared with outside. The results also highlighted a significant combined effect of habitat and protection for dugongs and Dasyatidae, as well as a significant effect of habitat alone for Dasyatidae. In contrast, no significant effect of habitat or protection was detected for sea turtles.In conclusion, this study revealed positive effects of protection (alone or combined with habitat) for four of the five studied megafauna taxa, confirming the effectiveness of the current MPA. Future studies should be conducted over broader spatial and temporal scales to examine whether detected effects hold beyond the surveyed period and area. [ABSTRACT FROM AUTHOR]

Basswood samples were exposed to oxygen glow-discharge plasmas for 30 min, and etching of radial and tangential longitudinal surfaces was measured. It was hypothesized that there would be a positive correlation between etching and plasma energy, and differential etching of wood surfaces because of variation in the microstructure and chemical composition of different woody tissues. Etching at the surface of basswood samples was examined using profilometry. Light and scanning electron microscopy were used to examine the microstructure of samples exposed to plasma. There was a large effect of plasma energy on etching of basswood surfaces, and radial surfaces were etched to a greater extent than tangential surfaces. However, rays at radial surfaces were more resistant to etching than fibers, resulting in greater variation in the etching of radial versus tangential surfaces. The same phenomenon occurred at radial surfaces of balsa wood, jelutong and New Zealand white pine subjected to plasma etching. The possible reasons for the greater resistance of rays to plasma etching are explored, and it is suggested that such differential etching of wood surfaces may impose a limitation on the use of plasma to precisely etch functional patterns at wood surfaces (raised pillars, grooves), as has been done with other materials.

Introduction: Elasmobranchs currently constitute an important part of the animal collection of many aquariums worldwide. Their maintenance under human care has allowed us to describe and identify new pathogens and diseases affecting them, as well as to determine different treatments for these diseases. Great advances in elasmobranch husbandry have been developed. Methods: A search was performed on scientific databases as PubMed and other specialized sources (IAAAM archive). Results: Little information on pharmacotherapeutics is available in this taxonomic group, and treatments lack a scientific base and instead are frequently dependent on empirical knowledge. Pharmacokinetic studies are the first step to determining therapeutic protocols that are safe and effective. The available bibliography shows that a majority of the mycoses recorded in cartilaginous fish are severe, aggravated by the fact that the antifungal treatments administered, following the guidelines used for teleost species, are ineffective in elasmobranchs. Azoles appear to be a promising group of antifungals for use in treating systemic mycoses in sharks and rays. Conclusions: Based on the findings of this review, it is essential to investigate the pharmacokinetics of the different antifungals in these species in order to provide therapeutic options for fungal infections in cartilaginous fish.

We recorded 23 Ranong guitarfish (Rhinobatos ranongensis) in Southwest Aceh, Indonesia. Measured specimens ranged between 72 and 87 cm total length. There are 20 recorded guitarfish species (Genus Rhinobatos) and so far, three of them have been recorded in Indonesia: Jimbaran shovelnose ray (Rhinobatos jimbaranensis), Indonesian shovelnose ray (Rhinobatos pengali) and Shaw's shovelnose guitarfish (Rhinobatos thouiniana). Rhinobatos ranongensis is listed as Vulnerable by IUCN and found in the Eastern Indian Ocean. The only recorded samples are from Andaman Sea, Myanmar and western Thailand. The specimens that landed in Southwest Aceh is the first recorded in Indonesia and the largest ever recorded. [ABSTRACT FROM AUTHOR]

Elasmobranchs are among the most endangered animals, with records of decline worldwide. In this context, we aim to understand the patterns and trends of scientific production, with special emphasis on conservation. Was performed a scientometric analysis on the Web of Science platform, collecting data on scientific production between 1950 and 2019. We identified 8,172 valid articles on elasmobranchs with production increasing exponentially during the study period. The trend of themes changed, in the 1980s descriptive biology stood out (for example, morphological and physiological studies) and currently themes related to life history, conservation and fisheries have gained space. Even so, there were few studies explicitly related to elasmobranch conservation, especially in Asian countries (only 5.5% of the articles from this region were conservation related) where threats from overexploitation are high. For the effective conservation of sharks and rays, it is vitally important that there are more incentives in research, there also needs to be a greater focus on less studied species, reducing the amount of data deficient species and filling the critical information gaps that currently undermine conservation efforts. [ABSTRACT FROM AUTHOR]

Ambient noise tomography is a powerful tool that has found increasing application in reservoir analysis and imaging. The Cachar fold belt in lower Assam, northeast India encompasses several wells under active hydrocarbon production, along with several dry wells. To overcome the lack of active seismic data over the entire fold belt, a passive seismic study was carried out to image the concealed three‐dimensional sub‐surface structures. The data were recorded from February to November 2011 by a network of 65 wideband seismometers spanning an area of about 40 × 60 km2. The data are crosscorrelated in the 2–5 s band, followed by phase‐weighted stacking to estimate noise correlation functions with surface wave signatures. The traveltimes picked from the frequency‐time analysis are utilized in a tomographic inversion for Rayleigh wave group velocities. The group velocity anomalies have a lateral resolution of ~ 3.5 × 5.5 km2 and variations of up to ±20%$\pm 20\%$ for each period. The group velocities are in turn inverted for S‐wave velocity distribution as a function of depth. The three‐dimensional S‐wave velocity tomograms reveal the tight anticlines and broad synclines, with high‐ and low‐velocity zones corresponding to structural highs and lows, respectively. The structural interpretation is supported for the part of the region with producing wells and covered by active seismic data, wherein the post‐stack time migrated seismic section shows anticlinal and synclinal features similar to those obtained from ambient noise tomography. The structures revealed by ambient noise tomography can help identify zones of interest to be targeted by active seismic surveys in the Cachar fold belt. [ABSTRACT FROM AUTHOR]

The objective of this paper was to characterize bycatch in an experimental fishery for Patagonian toothfish in Ecuador during 2017–2021. Diversity was analysed using Shannon, Margalef, Simpson, and Dominance indices. Bycatch representativity was calculated as the difference percentage between the target catch and non-target, in weight. The bycatch comprised 51 taxa and was composed primarily of fish. In addition, 12 species of pelagic habits (i.e. fishes and sharks) were also captured during the deployment/retrieval of fishing gear. The most frequent species (by number of individuals) were chimaeras (Hydrolagus melanophasma), grenadiers (Antimora rostrata , Coryphaenoides delsolari , and Coryphaenoides armatus), and sharks (Etmopterus granulosus and Centroscymnus owstonii). The diversity was medium low, according to the Shannon indices (0.5–1.8), with a negative trend for dominance and a positive trend for equitability. [ABSTRACT FROM AUTHOR]

Elasmobranchs play a significant role in structuring the marine food webs in many marine habitats. Estuaries provide an essential habitat primarily as nurseries for elasmobranchs. The present study investigates the feeding preferences of megabenthic predatory elasmobranchs from Caranzalem Bay, Goa. The elasmobranchs in this habitat were represented by guitarfishes, Glaucostegus granulatus and Glaucostegus obtusus; rays, Brevitrygon walga, Pastinachus sephen, Neotrygon kuhlii, and Maculabatis gerrardi; and bamboo sharks, Chiloscyllium griseum and Chiloscyllium spp. Crustaceans were the major prey of these predators followed by teleosts and cephalopods. The bamboo shark was an opportunistic predator while rays and guitarfish were specialised feeders on penaeid shrimps. Indices suggest that bamboo sharks occupy the highest trophic level in this benthic food chain while guitarfishes and rays function as mesopredators. Ontogenetic dietary changes were observed in all predators, indicating the feeding niche segregation among size classes. Low resource overlap was observed between and within species probably due to high prey availability in the bay. These elasmobranch species frequently occur in bycatch, which can negatively affect their populations and thereby impact the lower trophic strata resulting in large-scale ecological repercussions. [ABSTRACT FROM AUTHOR]

Based on ecosystem survey data in the Barents Sea in August–October 2004–2021. the results of studies of the distribution and size-sex composition of seven species of skates (Amblyraja radiata, Amblyraja hyperborea, Rajella fyllae and Bathyraja spinicauda as well as Dipturus oxyrinchus, Leucoraja fullonica and Rajella lintea), as well as estimates of the abundance and biomass of four common skate species. An expansion of the area and the northern and/or eastern boundaries of the distribution of warm-water boreal species of skates (round, spinytail) and some increase in their abundance and biomass were revealed. At the same time, a decrease in the abundance and biomass of the Arctic skate and a shift in its distribution to the cold-water part of the Barents Sea were noted. Significant changes in the size and sex composition of the majority of skate species were not revealed. [ABSTRACT FROM AUTHOR]

The results of hematological, cytochemical, and biochemical surveys for fish blood in the specimen Ocellate river stingray Potamotrygon motoro and two specimens of cat sharks including the Halmahera epaulette shark Hemiscyllium halmahera and the grey bambooshark Chiloscyllium griseumare have been reported. A comparison in the parameters analyzed in the survey between the common carp Cyprinus carpio, the wels catfish Silurus glanis, and the sterlet Acipenser ruthenus has been performed. A high percentage of eosinophils involved in antiparasite immunity in the Cartilaginous fishes is recorded. A high content of cationic protein in lysosomes of neutrophils in these fish species can indicate a considerable potent phagocytic activity of the latter. A low amount of alanine aminotransferase in the analyzed shark and ray specimens compared to the bony fish was recorded, which indicate the strength of membranes in hepatocytes and cardiomyocytes. [ABSTRACT FROM AUTHOR]

Research on the feeding habits of batoids provides information of intra and interspecific interactions of this taxon in marine ecosystems. We analyzed 832 stomachs of nine ray species collected from the artisanal fishery on the Northwest coast of Baja California Sur (NBCS). We identified 79 prey items assembled in five trophic groups (crustaceans, fish, mollusks, polychaetes, and sipunculidae). Results indicated that the red crab Pleuroncodes planipes was the most important prey in the diet of the seven batoid species. A low dietary similarity of the rays was observed, which evidenced different feeding strategies. In this regard, we identified four well‐separated trophic guilds. Each guild was characterized by the consumption of specific prey: (1) Hypanus dipterurus and Narcine entemedor that fed mostly on polychaetes; (2) Rostroraja velezi and Gymnura marmorata fed mostly on fishes (Clupeidae and Batrachoididae); (3) Hypanus longus, Myliobatis californica, and Platyrhinoidis triseriata fed on crustaceans (Munnidae) and Sipunculus worms; and (4) Pseudobatos productus and Zapteryx exasperata fed on crustaceans (Portunidae) and fishes (Synodontidae and Batrachoididae). We concluded that batoids off the NBCS show prey sharing between the different species. [ABSTRACT FROM AUTHOR]

We relied on local knowledge of fishers in five coastal communities in Ghana to investigate ecological factors that affect fishing for elasmobranchs (sharks and rays) and the changes in the abundance of sharks and rays from 1980 to 2020. We gathered data using participant observation, interviews, focus group discussions, and participatory rural appraisal techniques. The results revealed fisher's understanding of six main ecological conditions, which have been applied over the years to improve fishing and maximize fisher catch: season and weather conditions, lunar phase, bait type, presence of seabirds and fish movement, the color of seawater, and sea current. Most elasmobranch species were abundant in 1980 but became severely depleted as of 2020, except Blue Shark (Prionace glauca) and Devil rays (Mobula spp.), shared by the fishers. We found fishers' local ecological knowledge consistent with scholarly knowledge and call for its inclusion in research, decision-making, and management interventions by biologists and policymakers. [ABSTRACT FROM AUTHOR]

Introduction: Sometimes, a patient receives a poor quality medical image from a medical imaging center. Which the doctor orders to re-image with a drug contrast media agent. At this time, practical action is challenging to provide a proper image. Cobalt oxide nanoparticles show different activities based on different sizes and shapes. Objectives of this project is achievement a critical size of cobalt oxide nanoparticles between 5 to 10 nanometers for easy circulation in the blood and Investigation of the effect of cobalt oxide nanoparticles on the quality of CT from laboratory mice(Mus musculus).Material and Methods: In this study, the coupling method was used to prepare the cobalt oxide nanoparticles. Co3O4 nanoparticle coatings are used for this purpose. They were investigated through the Fourier-transform infrared (FTIR) analysis, X-rays diffraction (XRD). In order to investigate the efficacy of cobalt oxide nanoparticles, we injected a suspension into the Mus musculus, and then the computerized tomography (CT) scans were taken before and after injection of the nanoparticles. Then, quantity evaluation was performed using the calculating the average local contrast media of the whole image.Results: The average size of cobalt oxide nanoparticles was obtained about 5.8 nm, which is an appropriate size in the nanometer scale. After injecting of cobalt oxide nanoparticles into the mice and then CT scan imaging, we have obtained a better clarity.Conclusion: Cobalt oxide nanoparticles behave well for use as a pharmacological contrast media agent in CT scan imaging.