Search

Northern elephant seals (Mirounga angustirostris) have been integral to the development and progress of biologging technology and movement data analysis, which continue to improve our understanding of this and other species. Adult female elephant seals at Año Nuevo Reserve and other colonies along the west coast of North America were tracked annually from 2004 to 2020, resulting in a total of 653 instrument deployments. This paper outlines the compilation and curation process of these high-resolution diving and location data, now accessible in two Dryad repositories. The code used for data processing alongside the corresponding workflow is available through GitHub and Zenodo. This data set represents 3,844,927 dives and 596,815 locations collected from 475 individual seals with 178 repeat samplings over 17 years. We anticipate that these data will stimulate further analysis and investigation into elephant seal biology and aid in developing new analytical approaches for large marine predators.

Wildlife researchers must balance the need to safely capture and handle their study animals to sample tissues, collect morphological measurements, and attach dataloggers while ensuring their results are not confounded by stress artifacts caused by handling. To determine the physiological effects of research activities including chemical immobilization, transport, instrumentation with biologgers, and overnight holding on a model marine mammal species, we collected hormone, blood chemistry, hematology, and heart rate data from 19 juvenile northern elephant seals (Mirounga angustirostris) throughout a translocation experiment. Across our six sampling timepoints, cortisol and aldosterone data revealed a moderate hormonal stress response to handling accompanied by minor changes in hematocrit and blood glucose, but not ketone bodies or erythrocyte sedimentation rate. We also examined heart rate as a stress indicator and found that interval heart rate, standard deviation of heart rate, and apnea-eupnea cycles were influenced by handling. However, when seals were recaptured after several days at sea, all hormonal and hematological parameters had returned to baseline levels. Furthermore, 100 % of study animals were resighted in the wild post-translocation, with some individuals observed over four years later. Together, these findings suggest that while northern elephant seals exhibit measurable physiological stress in response to handling, they recover rapidly and show no observable long-term deleterious effects, making them a robust species for ecological and physiological research.

Air-breathing vertebrates must balance their response to diel shifts in prey accessibility with physiological thresholds and the need to surface after each dive. Weddell seal (Leptonychotes weddellii) dive behaviors were tracked across the year under rapidly-changing light regimes in the Ross Sea, Antarctica ( ~ 75-77°S). This provides a natural experiment with free-living seals experiencing 24-hrs of light (Polar Day), light/dark cycling, and continuous darkness (Polar Night). The Weddell seals temporal niche switches from nocturnal diving in the summer to diurnality for the remainder of the year. Rhythmicity in dive efforts (depth, duration, post-dive surface recuperation, bottom time, and exceeding physiologic thresholds) is stronger and more closely circadian during times of the year with light/dark cycling compared with Polar Day or Night. With light/dark cycling, animals also make the most extreme dives (those that far exceed the calculated aerobic dive limit, cADL) significantly earlier than solar noon. Offsetting the longest dives that require longer surface recuperation times from mid-day allows animals to maximize total dive time under high-light conditions conducive for visual hunting. We identify an optimal foraging strategy to exploit a diel preyscape in a highly-seasonal environment, while balancing tradeoffs imposed by physiological thresholds in a diving mammal.

Many animals and plants have species-typical annual cycles, but individuals vary in their timing of life-history events. Individual variation in fur replacement (moult) timing is poorly understood in mammals due to the challenge of repeated observations and longitudinal sampling. We examined factors that influence variation in moult duration and timing among elephant seals (Mirounga angustirostris). We quantified the onset and progression of fur loss in 1178 individuals. We found that an exceptionally rapid visible moult (7 days, the shortest of any mammals or birds), and a wide range of moult start dates (spanning 6-10× the event duration) facilitated high asynchrony across individuals (only 20% of individuals in the population moulting at the same time). Some of the variation was due to reproductive state, as reproductively mature females that skipped a breeding season moulted a week earlier than reproductive females. Moreover, individual variation in timing and duration within age-sex categories far outweighed (76-80%) variation among age-sex categories. Individuals arriving at the end of the moult season spent 50% less time on the beach, which allowed them to catch up in their annual cycles and reduce population-level variance during breeding. These findings underscore the importance of individual variation in annual cycles.

BACKGROUND: Elephant seals exhibit extreme hypoxemic tolerance derived from repetitive hypoxia/reoxygenation episodes they experience during diving bouts. Real-time assessment of the molecular changes underlying protection against hypoxic injury in seals remains restricted by their at-sea inaccessibility. Hence, we developed a proliferative arterial endothelial cell culture model from elephant seals and used RNA-seq, functional assays, and confocal microscopy to assess the molecular response to prolonged hypoxia. RESULTS: Seal and human endothelial cells exposed to 1% O2 for up to 6 h respond differently to acute and prolonged hypoxia. Seal cells decouple stabilization of the hypoxia-sensitive transcriptional regulator HIF-1α from angiogenic signaling. Rapid upregulation of genes involved in glutathione (GSH) metabolism supports the maintenance of GSH pools, and intracellular succinate increases in seal but not human cells. High maximal and spare respiratory capacity in seal cells after hypoxia exposure occurs in concert with increasing mitochondrial branch length and independent from major changes in extracellular acidification rate, suggesting that seal cells recover oxidative metabolism without significant glycolytic dependency after hypoxia exposure. CONCLUSIONS: We found that the glutathione antioxidant system is upregulated in seal endothelial cells during hypoxia, while this system remains static in comparable human cells. Furthermore, we found that in contrast to human cells, hypoxia exposure rapidly activates HIF-1 in seal cells, but this response is decoupled from the canonical angiogenesis pathway. These results highlight the unique mechanisms that confer extraordinary tolerance to limited oxygen availability in a champion diving mammal.

Populations and species are threatened by human pressure, but their fate is variable. Some depleted populations, such as that of the northern elephant seal (Mirounga angustirostris), recover rapidly even when the surviving population was small. The northern elephant seal was hunted extensively and taken by collectors between the early 1800s and 1892, suffering an extreme population bottleneck as a consequence. Recovery was rapid and now there are over 200,000 individuals. We sequenced 260 modern and 8 historical northern elephant seal nuclear genomes to assess the impact of the population bottleneck on individual northern elephant seals and to better understand their recovery. Here we show that inbreeding, an increase in the frequency of alleles compromised by lost function, and allele frequency distortion, reduced the fitness of breeding males and females, as well as the performance of adult females on foraging migrations. We provide a detailed investigation of the impact of a severe bottleneck on fitness at the genomic level and report on the role of specific gene systems.

Deep ocean foraging northern elephant seals (Mirounga angustirostris) consume fish and squid in remote depths of the North Pacific Ocean. Contaminants bioaccumulated from prey are subsequently transferred by adult females to pups during gestation and lactation, linking pups to mercury contamination in mesopelagic food webs (200-1000 m depths). Maternal transfer of mercury to developing seal pups was related to maternal mercury contamination and was strongly correlated with maternal foraging behavior (biotelemetry and isotopes). Mercury concentrations in lanugo (hair grown in utero) were among the highest observed worldwide for young pinnipeds (geometric mean 23.01 μg/g dw, range 8.03-63.09 μg/g dw; n = 373); thus, some pups may be at an elevated risk of sub-lethal adverse health effects. Fetal mercury exposure was affected by maternal foraging geographic location and depth; mercury concentrations were highest in pups of the deepest diving, pelagic females. Moreover, pup lanugo mercury concentrations were strongly repeatable among successive pups of individual females, demonstrating relative consistency in pup mercury exposure based on maternal foraging strategies. Northern elephant seals are biosentinels of a remote deep-sea ecosystem. Our results suggest that mercury within North Pacific mesopelagic food webs may also pose an elevated risk to other mesopelagic-foraging predators and their offspring.

Purpose: The purpose of this paper is to monitor leakage in the static sealing interface, using three-dimensional and two-dimensional surface topography parameters as indicators. Design/methodology/approach: This study involved developing a test rig for examining fluid leakage in metallic seals. Leakage of water through the interface of the metallic valve and valve seats was measured. The analysis focused on the combined effect of roughness, waviness and form error of metallic seal surfaces on leakage, with a detailed emphasis on the significance of form errors through harmonic analysis. Findings: The findings suggest that three-dimensional or areal surface texture parameters have more predictive control over leakage compared to two-dimensional or profile parameters, as they provide information about micro-leak channels in all directions. Moreover, it was observed that average amplitude parameters of surface topography, particularly the form error of metallic valves, are strongly correlated with leakage values compared with the roughness and waviness of the contact surface. In addition, the leakage in metallic seals is profoundly influenced by lower-order harmonics, with a corresponding increase as the average undulation number of the flatness profile rises. Originality/value: This research contributes to the understanding of the relationship between surface topography and sealing performance, particularly in metallic seals. By emphasizing the importance of form errors and using advanced surface texture analysis techniques, the study offers insights that can aid in optimizing the design and performance of static seals in industrial applications. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0186/ [ABSTRACT FROM AUTHOR]

A rise in pinniped-fisheries interactions has been observed due to the global decline in fish populations primarily attributed to overfishing, and/or due to the recent population recovery of several pinniped species. Although many studies have quantified these interactions, a limited number delve into their behavioral aspects. We consulted 374 studies on pinniped-fisheries interactions from 1980 to 2020 and analyzed which of them addressed the interaction from a behavioral perspective. Additionally, we examined the role of learning in pinnipeds and their ability to capture prey from fishing gear. The stimulus-reward relationship in operational interactions was addressed in 51 (14%) studies, involving 10 (19%) of the world's 54 pinniped species or subspecies. Depredation behavior (43%) and attack behavior (35%) were frequently reported during fishing interactions. Understanding associative and non-associative learning mechanisms has the potential to reduce economic losses from fishing activity, advance efficient mitigation measures to minimize conflicts, and establish pragmatic conservation priorities based on a better understanding of the behavioral aspects of these interactions. More research is needed to explore the effectiveness of deterrents in different species, improve methods of reducing habituation, and evaluate long-term behavioral effects, fostering effective strategies for minimizing conflicts and promoting coexistence between humans and pinnipeds. [ABSTRACT FROM AUTHOR]

Gas film floating ring seals are extensively utilized in aircraft engines, and precise analysis of gas film performance is crucial for ensuring reliable seal design. For this reason, this paper proposes the Reynolds–Bernoulli small-perturbation (RBSP) model to analyze the performance of the gas film based on the conservation of mechanical energy. Through experimental verification and comparison with other analytical models, the results of the RBSP model calculations are both reliable and more broadly applicable. Analyses using the finite element method revealed that the differential pressure effect of Poiseuille flow and the dynamic pressure effect of Couette flow are the primary factors enabling the floating ring to overcome resistance and establish a non-contact seal. Additionally, an appropriate sealing clearance and an increased width of the floating ring could significantly enhance the dynamic performance of the seal. The research findings offer a dependable performance analysis method for designers of gas film floating ring seals. [ABSTRACT FROM AUTHOR]

Clay sealings (cretulae) have traditionally been assumed to have been used in ancient administrative systems to secure the shipment of commodities and to account for their receipt. However, research in Western Asia has revealed that they were primarily used as a complex administrative tool in the management of storehouses and the goods they contained, ensuring the personal accountability of the individuals under whose seal or combination of seals particular items were stored. Although stamp seals are relatively common finds in the Indus Civilization, clay sealings are not as numerous as in contemporaneous sites throughout Western Asia. This rarity has led to speculation about the actual use of seals in the Indus Civilization. However, the study of an exceptional assemblage of clay sealings found at the Indus site of Lothal in Gujarat, India, has shed light on the function and use of these objects in the Indus Civilization. In particular, the stratigraphic analysis of the discovery context has made it possible to consider the existence of an administrative archive comparable to those excavated in Western Asia. [ABSTRACT FROM AUTHOR]

Copyright of Stratum Plus Journal is the property of P.P. Stratum plus and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the course of their long history in Aegean societies, seals acquired a polyvalent significance that arose from their active 'participation' in different social spheres and manifested itself in a superb level of technique and virtuosity. This paper examines the role of Minoan and Mycenaean seals as status symbols, highlighting not their creation but rather the practices of wearing, displaying, using, and perceiving them. The discussion spans two main chronological periods: the Second Palace Period (mid-17th to mid-15th century BCE) and the Third Palace Period (14th-13th century BCE), during which seals served different functions as status mediators. In the earlier period, a notable tension in the social significance of seals is evident when comparing evidence from Crete and the Greek Mainland. While Minoan seals were used as sphragistic tools, Mycenaean seals were not. In the later period, the use of seals in Mainland Greece was driven by their role as administrative tools within the palatial sphere. This dynamic analysis sheds light on the evolving roles and transformations of seals, influenced by varying social environments and demonstrating the multiple ways these artifacts embodied and mediated power. Additionally, it shows how their symbolic potential could express individual or collective identities. [ABSTRACT FROM AUTHOR]

Genetically diverse avian influenza viruses (AIVs) are maintained in wild aquatic birds with increasingly frequent spillover into mammals, yet these represent a small proportion of the overall detections. The isolation of AIVs in marine mammals, including seals, has been reported sporadically over the last 45 years. Prior to 2016, all reports of AIVs detected in seals were of low-pathogenicity AIVs. In spite of this, the majority of reported AIV outbreaks caused fatal respiratory diseases, with harbor seals particularly susceptible to infection. The H5 clade 2.3.4.4b highly pathogenic AIV (HPAIV) was detected in seals for the first time in 2016. Recently, many cases of mass seal die-offs have occurred because of 2.3.4.4b HPAIV and are attributed to spillover from wild bird species. The potential for seal-to-seal transmission has been considered after the mass mortality of southern elephant seals off the coast of Argentina. Close contact between seals and wild birds, the rapid evolution of H5N1 AIVs, and the possibility of efficient mammal-to-mammal transmission are increasing concerns due to the potential for the establishment of a marine mammal reservoir and public health risks associated with the pandemic potential of the virus. This manuscript details the detection of AIVs in the seal population, comparing interesting features of various subtypes with an emphasis on avian-to-mammal-to-mammal transmission. Phylogenetic characterizations of the representative seal isolates were performed to demonstrate the relationships within the different virus isolates. Furthermore, we demonstrate that the reassortment events between different LPAIVs occurred before and after the viruses reached the seal population. The reassortment of viral segments plays an important role in the evolution of influenza viruses. Taken together, these data report on the 45 year history between seals and AIVs. [ABSTRACT FROM AUTHOR]

Highly pathogenic avian influenza A(H5N1) virus was detected in dead seals on Tyuleniy Island in eastern Russia, in the Sea of Okhotsk. Viruses isolated from dead northern fur seals belong to clade 2.3.4.4b and are closely related to viruses detected predominantly in the Russian Far East and Japan in 2022–2023.

The heat source analysis and quantitative calculation of heat production of the bearing-support structure system can provide a reliable basis for the thermal protection design of the bearing cavity. Through theoretical analysis of heat transfer and tribology，a heat generation analysis model for the bearing-support system of an aircraft engine is established. 1D thermal-fluid coupling calculations of the bearing-support system are carried. The intermediate bearing support frames of the aero-engine compressor and turbine are analyzed for heat generation separately to evaluate the effects of different heat sources on the heat generation of the bearing-support system under cruise operating conditions. The results show that the wall temperature of the right frame of the compressor intermediate support system increases radially upward by 1.73%. The heat transfer coefficient（HTC）increases radially upward by 20 times due to the presence of interstage sealing between the main flow path and the disk cavity. Among them，the heat sources with the highest percentage of heat generation are through the support walls，bearings，and seals，and heat generation by the seals in the bearing-support system accounts for 29% in the intermediate bearing support frame of the compressor and 35% in the intermediate bearing support frame of the turbine.

This is a study of initial stages of adaptation of the ancient human population to the use of aquatic food supplies in the White Sea. The main aim of archaeozoological analysis was to study the processes of formation of faunal remains and strategies on seals hunting during the Eneolithic in the White Sea region. The archaeological source material consists of faunal remains recovered from two Eneolithic sites of the Kandalaksha bay. The results of archaeozoological studies confirmed the high importance of the ringed seal and harp seal in the hunting prey of the inhabitants of the studied sites. Eneolithic hunting strategies of the White Sea region were closely related to the behavioral and ecological patterns of seals. The seal hunt was based on a model of exploiting a massive seasonal resource. Hunting pressure on the ringed seal and harp seal populations was significant. Seals were the main suppliers of meat, skin and fat for the inhabitants of the Eneolithic sites of this part of Fennoscandia. The studies of the lithic tools from the Early Metal period settlements from Kandalaksha bay provide additional evidences of a specialized marine hunting. Apparently, in the Eneolithic (IV – III millennia calBC), the economic and cultural type of sea hunters was formed on the shores of the White Sea.

Failures in hydraulic systems in offshore wind turbines represent an enormous challenge for manufacturers and operators, as the pitch system statistically is one of the subsystems contributing the most to the downtime of the turbines, which is the case for both electrical and hydraulic pitch systems. However, the complex failure mechanisms of the various different hydraulic components mean that, typically, the critical components of hydraulic systems must be tested to better understand the failure mechanisms. Nonetheless, conventional testing procedures are lengthy and costly. Accelerated testing plays a critical role as it can mimic hydraulic system failure mechanisms in a shorter period. However, the lack of standardized test methods and detailed knowledge about the failure-accelerating effects complicates the process. Therefore, this paper offers a comprehensive examination of approaches applicable to conducting accelerated tests on hydraulic systems. It identifies and discusses five primary component types or sub-components related to the acceleration of testing in hydraulic systems: pumps, cylinders, seals, valves, and hoses. Each section references studies that delve into accelerated testing methodologies for these individual components. Furthermore, within each component, a concise overview of the current techniques is provided, followed by a discussion and summary based on the state of the art.

Museum specimens preserve genetic information that can help resolve phylogenetic relationships of now extinct species. The Caribbean monk seal, Neomonachus tropicalis, is the only marine mammal driven to extinction in tropical seas and one of the few marine mammals to go extinct in historical times. Prior to 1700 it was widely distributed throughout the coasts of North, Central and South America, and in the Bahamas, Greater and Lesser Antilles. The species was first taxonomically placed in the genus Monachus, along with the Hawaiian and Mediterranean monk seals and it was later moved together with the Hawaiian monk seal into the newly described genus Neomonachus. Here, we present the complete mitochondrial genome of the Caribbean monk seal and a phylogenetic reconstruction, confirming its sister taxa relationship with the Hawaiian monk seal, and thus the monophyly of the genus Neomonachus. Our estimates of divergence times are contemporaneous with or predate the emergence of the Isthmus of Panama. We also identify limited genetic variation among five specimens of Caribbean monk seal. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Babylon Center for Humanities Studies is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For DanaIt is often forgotten that a variety of French peculiar to the British Isles, known as Anglo-Norman was, for more than four centuries post-Conquest, the default language for inscriptions of an amatory nature, on jewellery especially. The large number of inscribed rings, brooches and seal matrices unearthed by metal-detectorists in recent decades whose finds are recorded in detail on the Portable Antiquities Scheme (PAS) database have prompted this consideration of these legends — often simple rhyming couplets or 'posies' — especially in the context of that set of romantic conventions retrospectively termed 'Courtly Love'.1 [ABSTRACT FROM AUTHOR]

The paper considers the appearance and meaning of city walls on ducal and municipal seals in 13th-century Poland. Despite the great popularity of the motif, actual stone or brick fortifications, both of towns and castles, were rare in Poland at the time. It is especially striking that in the area of Kuyavia, where local dukes introduced the motif onto their seals at an early stage, such architectonic structures were almost entirely absent. Several towns also employed images of stone walls on their seals before they gained the real fortifications. The motif of fortification is examined here as a symbol of civilization in a wider sense, and particularly that of the communal town. The final section the paper explores ways in which Polish society might have come to understand this symbolism. [ABSTRACT FROM AUTHOR]

This study investigates the tribological behaviour of copper-impregnated carbo-graphite (ICG) compared to plain carbo-graphite (CG) under various parameter-product (PV) values and temperatures. Impregnation significantly enhanced ICG's hardness (70%) and reduced porosity (98.6%) compared to CG. The CoF for CG was lower than that for ICG attributed to the formation of a lubricating graphite-rich tribo-film that facilitated easy shearing at the contact interface. The wear mechanisms for CG at elevated temperatures were identified as adhesion, oxidation and delamination, likely exacerbated by the material's softening. In contrast, ICG exhibited superior wear resistance, attributed to its higher hardness and the formation of a protective tribo-layer containing copper and graphite. This tribo-layer offered a low-shear interface at lower PV values, reducing friction. However, at higher PV values, ICG wear increased due to abrasion and adhesion. Overall, copper impregnation offers a promising strategy to improve the wear resistance of carbo-graphite, particularly at elevated temperatures. [ABSTRACT FROM AUTHOR]

Failures in hydraulic systems in offshore wind turbines represent an enormous challenge for manufacturers and operators, as the pitch system statistically is one of the subsystems contributing the most to the downtime of the turbines, which is the case for both electrical and hydraulic pitch systems. However, the complex failure mechanisms of the various different hydraulic components mean that, typically, the critical components of hydraulic systems must be tested to better understand the failure mechanisms. Nonetheless, conventional testing procedures are lengthy and costly. Accelerated testing plays a critical role as it can mimic hydraulic system failure mechanisms in a shorter period. However, the lack of standardized test methods and detailed knowledge about the failure-accelerating effects complicates the process. Therefore, this paper offers a comprehensive examination of approaches applicable to conducting accelerated tests on hydraulic systems. It identifies and discusses five primary component types or sub-components related to the acceleration of testing in hydraulic systems: pumps, cylinders, seals, valves, and hoses. Each section references studies that delve into accelerated testing methodologies for these individual components. Furthermore, within each component, a concise overview of the current techniques is provided, followed by a discussion and summary based on the state of the art. [ABSTRACT FROM AUTHOR]

Highly pathogenic influenza A virus (HPIAV) H5N1 within the genetic clade 2.3.4.4b has emerged in wild birds in different regions of the world, leading to the death of >70 million birds. When these strains spread to pinniped species a remarkable mortality has also been observed. A detailed genetic characterization of HPIAV isolated from pinnipeds is essential to understand the potential spread of these viruses to other mammalian species, including humans. To gain insight into these matters a detailed phylogenetic analysis of HPIAV H5N1 2.3.4.4b strains isolated from pinniped species was performed. The results of these studies revealed multiple transmission events from birds to pinnipeds in all world regions. Different evolutionary histories of different genes of HPIAV H5N1 2.3.4.4b strains gave rise to the viruses infecting pinnipeds in different regions of the world. European strains isolated from pinnipeds represent a completely different genetic lineage from strains isolated from South American ones. All strains isolated from pinnipeds bear characteristics of a highly pathogenic form for of avian influenza in poultry. Amino acid substitutions, previously shown to confer an adaptive advantage for infecting mammals, were observed in different genes in all pinniped species studied.

The working processes and integral characteristics of piston long-stroke low-speed compressor stages are considered. Well-known technologies for increasing the feed rate are considered as objects of comparison: selection of the main dimensions and parameters of the stage; changing the size and design of valves, using elastomeric structural materials; change in the design of the cylinder-piston seal; changing the layout of the suction valve in the working chamber. Indicator efficiency, supply coefficient and tightness coefficient, as well as discharge temperature are considered as integral indicators. The following independent parameters are considered: parameters of the state of the working fluid at suction, discharge pressure, main dimensions and parameters of the stage, distance from the suction valve to the top dead center, seat diameters of the suction and discharge valves, as well as physical and mechanical properties of structural materials. A comparative analysis of the efficiency of the working process of the stage under consideration is carried out using various technologies for reducing the intensity of mass transfer through leaks in the working chamber of a low-speed, long-stroke piston stage. An assessment is made of the achievable value of the feed coefficient with the combined use of various technologies. The features of the working processes of the object under consideration and the relationship between the intensity of mass flows of working gas through leaks in the working chamber of the stage and the technologies used have been studied. The presented results of the theoretical analysis reflect the nature of the change in the integral characteristics of the stage depending on the technologies used to reduce the intensity of mass transfer through leaks in the working chamber of the stage under consideration.

Sleep is a crucial part of the daily activity patterns of mammals. However, in marine species that spend months or entire lifetimes at sea, the location, timing, and duration of sleep may be constrained. To understand how marine mammals satisfy their daily sleep requirements while at sea, we monitored electroencephalographic activity in wild northern elephant seals (Mirounga angustirostris) diving in Monterey Bay, California. Brain-wave patterns showed that seals took short (less than 20 minutes) naps while diving (maximum depth 377 meters; 104 sleeping dives). Linking these patterns to accelerometry and the time-depth profiles of 334 free-ranging seals (514,406 sleeping dives) revealed a North Pacific sleepscape in which seals averaged only 2 hours of sleep per day for 7 months, rivaling the record for the least sleep among all mammals, which is currently held by the African elephant (about 2 hours per day).

Age determination of wild animals, including pinnipeds, is critical for accurate population assessment and management. For most pinnipeds, current age estimation methodologies utilize tooth or bone sectioning which makes antemortem estimations problematic. We leveraged recent advances in the development of epigenetic age estimators (epigenetic clocks) to develop highly accurate pinniped epigenetic clocks. For clock development, we applied the mammalian methylation array to profile 37,492 cytosine-guanine sites (CpGs) across highly conserved stretches of DNA in blood and skin samples (n = 171) from primarily three pinniped species representing the three phylogenetic families: Otariidae, Phocidae and Odobenidae. We built an elastic net model with Leave-One-Out-Cross Validation (LOOCV) and one with a Leave-One-Species-Out-Cross-Validation (LOSOCV). After identifying the top 30 CpGs, the LOOCV produced a highly correlated (r = 0.95) and accurate (median absolute error = 1.7 years) age estimation clock. The LOSOCV elastic net results indicated that blood and skin clock (r = 0.84) and blood (r = 0.88) pinniped clocks could predict age of animals from pinniped species not used for clock development to within 3.6 and 4.4 years, respectively. These epigenetic clocks provide an improved and relatively non-invasive tool to determine age in skin or blood samples from all pinniped species.

Social identity influences policy preferences and actions regarding wildlife. Using data from a survey of residents, commercial fishers, and tourists on Cape Cod, Massachusetts, this study examined the relationships between self-selected social identities (i.e., animal protection, environmental, hunter, and angler) within these stakeholder groups and ocean management priorities, support for the Marine Mammal Protection Act (MMPA), and acceptance of lethal management of seals and white sharks. Results revealed three social identity clusters: (1) identification with environmental and animal protection groups (non-consumptive), (2) identification with both non-consumptive (environmental, animal protection) and consumptive (angler, hunter) groups, and (3) identification with none of the groups. Residents were a mix of identities; tourists primarily identified with the non-consumptive and, to a lesser extent, no identification clusters; and commercial fishers identified with the mixed nonconsumptive/consumptive and no identification clusters. The overlap between consumptive and non-consumptive identifications illustrates the heterogeneity of social identity. Participants in the non-consumptive cluster favored policies prioritizing wildlife, the environment, and marine mammal protections more strongly than those in other clusters. Findings contribute to research examining social identity theory to improve understanding of public wildlife management preferences, within the novel context of rebounding populations of marine predators such as pinnipeds and white sharks. [ABSTRACT FROM AUTHOR]

Bijapur, now a district headquarters in Karnataka, was formerly the seat of the Adil Shahi kingdom of the Deccan which ruled the region for nearly two centuries (1489-1686 AD). The founder of the Adilshahi dynasty, Sultan Yusuf Adil Shah made Bijapur, or Vijyapur the capital of the Bijapur kingdom. The rulers of the Adilshahi dynasty ordered their engravers to engrave the seals in their names. We find many seals of this dynasty representing different rulers, princes, princesses, or officials. The seals of the Adil Shahi dynasty are very peculiar in many facets. Some important seals of the same period will be studied in this small article. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Historía da Sociedade e da Cultura is the property of Revista de Historia da Sociedade e da Cultura and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the tribological behavior of elastomers in dry conditions is essential for sealing applications, as dry contact may occur even in lubricated conditions due to local dewetting. In recent decades, Persson and co-authors have developed a comprehensive theory for rubber contact mechanics and dry friction. In this work, their model is implemented and extended, particularly by including static friction based on the bond population model by Juvekar and coworkers. Validation experiments are performed using a tribometer over a wide range of materials, temperatures and speeds. It is shown that the friction model presented in this work can predict the static and dynamic dry friction of various commercial rubber materials with different base polymers (FKM, EPDM and NBR) with an average accuracy of 10%. The model is then used to study the relevance of different elastomer friction contributions under various operating conditions and for different roughness of the counter surface. The present model will help in the development of novel optimized sealing solutions and provide a foundation for future modeling of lubricated elastomer friction. [ABSTRACT FROM AUTHOR]

There exists widespread evidence that the Near Eastern societies manufactured seals. However, among these, South Arabian seals remain largely neglected while performing various particularly revealing functions. For instance, the practice of sealing allowed for the explicit expression of ownership as well as the act of witnessing in legal matters. More broadly, seals were a means of articulating individual identities and reinforcing communal belonging. This paper is the first study on the seals of ancient South Arabia after the unpublished Ph.D. dissertation by Diana P. Wong (1999. "Stamp Seals of the Ancient Yemen." Unpublished PhD diss., Berkely). It investigates a corpus comprising 85 published seals currently held in museums and private collections across three continents. After providing a brief survey of the region's history, this article analyses the epigraphic and iconographic content carved on the corpus, offering some reflections on the typology and characteristics of the seals, as well as on the society of ancient South Arabia. [ABSTRACT FROM AUTHOR]

From 2011-2018, we conducted surveillance in marine mammals along the California coast for influenza A virus (IAV), frequently detecting anti-influenza antibodies and intermittently detecting IAV. In spring 2019, this pattern changed. Despite no change in surveillance intensity, we detected IAV RNA in 10 samples in March and April, mostly in nasal and rectal swabs from northern elephant seals (Mirounga angustirostris). Although virus isolation was unsuccessful, IAV sequenced from one northern elephant seal nasal swab showed close genetic identity with pandemic H1N1 IAV subclade 6B.1A.1 that was concurrently circulating in humans in the 2018/19 influenza season. This represents the first report of human A(H1N1)pdm09 IAV in northern elephant seals since 2010, suggesting IAV continues to spill over from humans to pinnipeds.

Gas film floating ring seals are extensively utilized in aircraft engines, and precise analysis of gas film performance is crucial for ensuring reliable seal design. For this reason, this paper proposes the Reynolds–Bernoulli small-perturbation (RBSP) model to analyze the performance of the gas film based on the conservation of mechanical energy. Through experimental verification and comparison with other analytical models, the results of the RBSP model calculations are both reliable and more broadly applicable. Analyses using the finite element method revealed that the differential pressure effect of Poiseuille flow and the dynamic pressure effect of Couette flow are the primary factors enabling the floating ring to overcome resistance and establish a non-contact seal. Additionally, an appropriate sealing clearance and an increased width of the floating ring could significantly enhance the dynamic performance of the seal. The research findings offer a dependable performance analysis method for designers of gas film floating ring seals.

Genetically diverse avian influenza viruses (AIVs) are maintained in wild aquatic birds with increasingly frequent spillover into mammals, yet these represent a small proportion of the overall detections. The isolation of AIVs in marine mammals, including seals, has been reported sporadically over the last 45 years. Prior to 2016, all reports of AIVs detected in seals were of low-pathogenicity AIVs. In spite of this, the majority of reported AIV outbreaks caused fatal respiratory diseases, with harbor seals particularly susceptible to infection. The H5 clade 2.3.4.4b highly pathogenic AIV (HPAIV) was detected in seals for the first time in 2016. Recently, many cases of mass seal die-offs have occurred because of 2.3.4.4b HPAIV and are attributed to spillover from wild bird species. The potential for seal-to-seal transmission has been considered after the mass mortality of southern elephant seals off the coast of Argentina. Close contact between seals and wild birds, the rapid evolution of H5N1 AIVs, and the possibility of efficient mammal-to-mammal transmission are increasing concerns due to the potential for the establishment of a marine mammal reservoir and public health risks associated with the pandemic potential of the virus. This manuscript details the detection of AIVs in the seal population, comparing interesting features of various subtypes with an emphasis on avian-to-mammal-to-mammal transmission. Phylogenetic characterizations of the representative seal isolates were performed to demonstrate the relationships within the different virus isolates. Furthermore, we demonstrate that the reassortment events between different LPAIVs occurred before and after the viruses reached the seal population. The reassortment of viral segments plays an important role in the evolution of influenza viruses. Taken together, these data report on the 45 year history between seals and AIVs.

The efficiency of quarry hydraulic excavators will depend on several factors, namely the climatic conditions of the area where hydraulic excavators are used, the degree of air pollution (pollination), the performance of the structural parts of the excavator, the reliability of the hydraulic system, the performance and cleanliness of the hydraulic working fluid. In this area, research was carried out on the performance of seals used in the hydraulic system of quarry excavators. The article presents the results of experimental tests of the existing type of oil seal a and b, as well as the proposed oil seal type c, shown in Fig. 1. [ABSTRACT FROM AUTHOR]

Under the Marine Mammal Protection Act of 1972, seals have recolonized historic ranges along the New England coast after near extirpation from bounty hunting in the 19th and 20th centuries. On Cape Cod, Massachusetts, concerns that rebounding seal populations damage fisheries and draw great white sharks have led some to call for a seal cull. Surveys on Cape Cod found strong opposition to lethal management among residents and tourists, and neutrality, on average, among commercial fishers. For all three samples, lethal management support was substantially explained by general attitudes toward seals and partially mediated by specific ecological benefits and risks associated with seals. Positive attitudes toward seals and perceived ecosystem benefits reduced support for lethal management among residents, tourists and commercial fishers. Negative attitudes and perceived ecological risks of seals increased lethal management support. These findings suggest communication of the ecological benefits of species can enhance continued marine mammal conservation. [ABSTRACT FROM AUTHOR]

This article deals with the question of the extent to which the Teutonic Order, as a clerical order of knights founded during the Third Crusade, succeeded in expressing its self-confidence and identity by means of its seal. The "geographical" area of investigation extends to the bailiwicks of Franconia, Alsace–Burgundy, Lorraine, Austria, An der Etsch and in the mountains (South Tyrol) as well as the so-called Deutschmeistertum, whereby the terms mentioned do not necessarily correspond to the present-day areas of that designation. The time frame is within the Middle Ages. Due to the large number of surviving seals of the Teutonic Order, however, only a small insight from a larger study can be provided here. Selected seals of the Order's various internal leadership strata are therefore presented, compared and examined to determine whether and to what extent they express a form of self-confidence and identity. [ABSTRACT FROM AUTHOR]

The in-pipe robot is the most commonly used technique in offshore pipelines. The use of rubber sealing discs is important for in-pipe robots to ensure that the robots are moved by fluid pressures inside offshore pipelines. This paper focuses on the measuring and modeling of the wax–oil gel-breaking process at the soft frictional area between sealing discs and the pipe wall. In this study, a detailed characterization of the gel-scraping process and in situ probing portable microscopy are performed. Two contributions are made in this study. First, a direct observation of wax–oil deposition breaking is employed to detect the minute changes at the in-pipe robot. Second, we find that a simple function is possible to describe the relationship between the wax contents and dewaxing efficiency, in which the debris material removal ratio (DRR) is discussed. Thus, the gel deposition-breaking phenomena are quite different under the influence of rubber sealing discs. This result is further confirmed by the real contact ratio measurements. It is important to research the sealing disc further and apply it more in the petroleum industry, especially in in-pipe robots for deepwater pipeline systems. [ABSTRACT FROM AUTHOR]

Social identity influences policy preferences and actions regarding wildlife. Using data from a survey of residents, commercial fishers, and tourists on Cape Cod, Massachusetts, this study examined the relationships between self-selected social identities (i.e., animal protection, environmental, hunter, and angler) within these stakeholder groups and ocean management priorities, support for the Marine Mammal Protection Act (MMPA), and acceptance of lethal management of seals and white sharks. Results revealed three social identity clusters: (1) identification with environmental and animal protection groups (non-consumptive), (2) identification with both non-consumptive (environmental, animal protection) and consumptive (angler, hunter) groups, and (3) identification with none of the groups. Residents were a mix of identities; tourists primarily identified with the non-consumptive and, to a lesser extent, no identification clusters; and commercial fishers identified with the mixed non-consumptive/consumptive and no identification clusters. The overlap between consumptive and non-consumptive identifications illustrates the heterogeneity of social identity. Participants in the non-consumptive cluster favored policies prioritizing wildlife, the environment, and marine mammal protections more strongly than those in other clusters. Findings contribute to research examining social identity theory to improve understanding of public wildlife management preferences, within the novel context of rebounding populations of marine predators such as pinnipeds and white sharks.

This article is a translation of Of seals and souls: Changes in the position of seals in the world-view of Icelandic small-scale fishermen, published in 1990 in volume 3, number 2 of Maritime Anthropological Studies. It was translated by Karina Gerdau. This article deals with the changing attitudes of Icelandic artisanal fishermen towards seals. The material on which this study is based comes from fieldwork in a fishing village on Iceland's east coast, but also from the author's experience as a native participant in artisanal fishing. It is often argued that, in order to understand a particular cultural change, it is necessary to see how it is "externally induced yet indigenously orchestrated" (Sahlins, 1985. p. viii). In this case, the external influence came from campaigns against the slaughter of marine mammals by environmental and animal protection organizations.