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The use of biological hard structures, such as otoliths, is the most common method of aging bony fish (Pannella, 1971; Gauldie and Nelson, 1990; Stevenson and Campana, 1992), dating back [...]

The elemental composition of mineralized vertebral cartilage has proven useful for reconstructing the movement and environmental history of elasmobranchs. However, the effects of intrinsic and extrinsic factors on vertebral chemistry have not been well explored, making meaningful interpretations of results difficult. This study quantified trace element incorporation along the corpus calcareum of 116 Round Stingray (Urobatis halleri) vertebrae and explored the influence of intrinsic (i.e., sex) and extrinsic (i.e., location and year) factors on vertebral edge chemical variations. We quantified eight element/Ca ratios (Li/Ca, Mg/Ca, Mn/Ca, Co/Ca, Cu/Ca, Zn/Ca, Sr/Ca, Ba/Ca) by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Behavioral sexual segregation by Round Stingrays explained differences found in Mn/Ca, Zn/Ca, Sr/Ca, and Ba/Ca ratios. Higher vertebral Mn/Ca and Zn/Ca in females likely originate from the use of salt marsh habitats as a refuge as well as higher reproductive hormone concentrations during gestation, respectively. Female and male Round Stingrays were also found to have an inverse relationship between Sr/Ca and Ba/Ca, likely due to environmental differences (e.g., temperature) between their sexually segregated habitats. This study demonstrates how multielement signatures in vertebral cartilage may improve understanding of habitat use and migration throughout life and advances the development of biomineral usage as an environmental proxy in elasmobranchs., Author(s): Bethany E. Brodbeck [sup.1] [sup.2] , Kady Lyons [sup.3] , Nathan R. Miller [sup.4] , John A. Mohan [sup.1] Author Affiliations: (1) grid.266826.e, 0000 0000 9216 5478, School of [...]

IMPACT: This article presents novel analyses of the income sources of National Health Service (NHS) acute trusts in England. The results suggest that there are variations according to deprivation in the extent of private financial resources available to NHS institutions. They suggest a need to open up discussions about how best to mitigate spatial differences in the charitable and private patient income of NHS trusts, particularly if these sources of income grow in importance going forward. The article provides—for the first time—an analysis of spatial variation in the income sources of National Health Service (NHS) acute trusts in England. It shows that, compared to trusts serving less deprived communities, trusts serving more deprived communities receive a lower proportion of income from charitable sources; and that trusts serving deprived communities also receive a lower proportion of income from private patients. The study serves to provide evidence of spatial inequality in the private resources that support local public institutions. [ABSTRACT FROM AUTHOR]

The broken inversion symmetry at the ferromagnet (FM)/heavy‐metal (HM) interface leads to spin‐dependent degeneracy of the energy band, forming spin‐polarized surface states. As a result, the interface serves as an effective medium for converting spin accumulation into 2D charge current through the inverse Rashba–Edelstein effect. Exploring and assessing this spin‐to‐charge conversion (SCC) phenomenon at the FM/HM interface can offer a promising avenue to surpass the presumed limits of SCC in bulk HM layers. Spintronic heterostructures are utilized as a platform to measure the SCC experienced by photoexcited spin currents. Therefore, FM/HM heterostructures emitting terahertz electric field upon illumination by femtosecond laser pulses enable quantitative measure of the ultrafast SCC process. This results demonstrate a robust interfacial spin‐to‐charge conversion (iSCC) within a synthetic antiferromagnetic heterostructure, specifically for the NiFe/Ru/NiFe configuration, by isolating the SCC contribution originating from the interface and the bulk heavy‐metal (HM). Through the measurements of the emitted terahertz pulse, the iSCC at the NiFe/Ru interface is identified to be ≈27% of the strength as compared to SCC from the highest spin‐Hall conducting heavy‐metal, Pt. The results thus highlight the significance of interfacial engineering as a promising pathway for achieving efficient ultrafast spintronic devices. [ABSTRACT FROM AUTHOR]

Collective spin arrangements manifest diverse spin textures, encompassing ferromagnetism, antiferromagnetism, and chiral vortices. However, mapping these spin textures in ultrathin magnetic multilayers has remained elusive. A reconfigurable chiral spintronic terahertz emission method is introduced through investigations on a model system of synthetic antiferromagnet and the spin information of individual ferromagnet (FM) layers is extracted. Upon femtosecond photoexcitation of the synthetic antiferromagnet (FM1/Ru/FM2), the ferromagnets generate a pair of linearly polarized ultrafast spin currents, which, after relaxation at the FM/Ru interface, emit corresponding THz pulses. The Ruderman–Kittel–Kasuya–Yosida interactions between the two FMs give rise to magnetic‐field‐controlled spin textures causing a spin relaxation imbalance at the interfaces and induce a phase shift between the orthogonal components of the emitted terahertz fields, consequently reconfiguring the polarization of the emitted terahertz field from linear to circular. This approach offers a novel means of investigating electronic and magnetic states in ultrathin spintronic heterostructures, low‐dimensional quantum materials, topological insulators, and Weyl semimetals. Furthermore, it enables the exploration of spin textures, including skyrmions, merons, and solitons. [ABSTRACT FROM AUTHOR]

Objective: Understanding the spatial connectivity of elasmobranch populations is critical for regional fisheries management. The Blacktip Shark Carcharhinus limbatus is abundant in coastal waters of the Gulf of Mexico (GoM) and important in recreational and commercial fisheries. Based on genetic and tagging studies, GoM Blacktip Sharks are currently managed under separate quotas between the eastern and western GoM (divided at 88°W), but no studies have used vertebral chemistry to assess the population structure of adult Blacktip Sharks. Methods: We compared vertebral elemental signatures (barium [Ba], magnesium [Mg], manganese [Mn], strontium [Sr], and zinc [Zn]) for the first year of life with last occupied habitats (vertebral edges) in Blacktip Sharks collected from the western (Texas and Louisiana) and eastern (Alabama and Florida) coastal waters of the northern GoM. Result: We found significant regional differences in Ba, Mg, Mn, and Sr vertebral edge signatures, suggesting ecological separation of Blacktip Sharks. Significant correlation between first‐year and edge signatures suggested a high degree of residency between life stages. Cross‐validated discriminant function analyses yielded highest regional classification accuracies when Florida sharks were grouped separately west of 88°W (90%), demonstrating the unique elemental signatures of eastern versus western GoM Blacktip Sharks under current management delineations. Conclusion: Combined, these findings demonstrate that trace element markers can distinguish regional populations of Blacktip Sharks and provide a complimentary approach in addition to genetics and physical tagging to support current stock management efforts. Impact statementStocks of Blacktip Sharks are managed under separate quotas in the eastern and western Gulf of Mexico. In this study, elemental signatures in mineralized vertebral cartilage of Blacktip Sharks confirm ecological population separation. Natural chemical tags in shark vertebrae offer an additional tool to characterize population connectivity and stock delineation for highly migratory shark species. [ABSTRACT FROM AUTHOR]

The impurity incorporation in host high spin-orbit coupling materials like platinum (Pt) has shown improved charge-to-spin conversion efficiency by modifying the up-spin and down-spin electrons trajectories via bending or skewing them in opposite directions. This enables efficient generation, manipulation, and transport of spin currents. In this study, we irradiated the Pt thin films with pulsed hot dense oxygen plasma in non-focus mode operation and analyzed the spin Hall angle of the oxygen plasma irradiated Pt films using spin torque ferromagnetic resonance (ST-FMR). Our results demonstrate a 2.4 times enhancement in the spin Hall angle after transient oxygen plasma treatment of Pt as compared to pristine Pt. This improvement might be because of the introduction of disorder and defects in the Pt lattice due to transient oxygen plasma processing, which enhanced the spin-orbit coupling and leads to more efficient charge-to-spin conversion without breaking the spin-orbit torque symmetries. Our findings offer a new method of dense plasma focus device-based modification of material for the development of advanced spintronic devices based on Pt and other heavy metals. [ABSTRACT FROM AUTHOR]

Validation of band pair deposition rates in elasmobranch vertebrae is essential for accurate age estimation using band pair counting techniques. We present a validation study of the vertebral band pair deposition rate for juvenile common thresher sharks Alopias vulpinus in the northeastern Pacific Ocean (NEPO) using tag and recapture with oxytetracycline (OTC) injection. A total of 14 juvenile A. vulpinus marked with OTC from 1998 through 2013 were recaptured with times at liberty ranging from 1.08 to 3.81 years with an average of 2.14 years (±0.97 years standard deviation, SD). Shark size ranged from 80 to 128 cm fork length (LF) at the time of OTC injection and from 112 to 168 cm LF for those measured at recapture. The slopes of the relationships between band pairs post OTC and years at liberty for each reader ranged from 0.84 to 0.95, slightly lower than the 1.0 slope expected from annual band pair formation. These findings preliminarily support previous age and growth assumptions based on a one band pair per year deposition rate. However, high variation in band pair deposition rates between samples, coupled with regression slopes falling just under one band pair per year, indicates that further investigation is needed to refine band pair deposition rate estimates. [ABSTRACT FROM AUTHOR]

Post‐release mortality threatens shark populations already imperiled by overfishing, capture stress, and a changing climate. Few studies have quantified post‐release mortality for sharks captured in land‐based recreational fisheries. From 2018 to 2021, a land‐based shark post‐release mortality study was conducted and identified water temperature and species‐specific behavior as contributing factors to post‐release mortality. The purpose of this study was to estimate the effectiveness of disseminating the recommendation for best practices to recreational shark anglers and to determine if this information influenced angler behavior. Awareness of our post‐release mortality study influenced an angler's likely release behavior, with an increase in sharks landed in the water and corresponding decrease of sharks landed on dry sand. This study demonstrated direct evidence of conservation‐based changes in angler behavior following effective research communication and involvement of anglers in research. Outreach and engagement initiatives aimed at providing best handling practices to recreational anglers should be easily digestible, widely available, and an important component of future research. [ABSTRACT FROM AUTHOR]

Stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) are ubiquitous ecological tracers used to elucidate an organism's diet and habitat. However, the application of stable isotope ratios to reconstruct a consumer's ecology relies upon accurate rates for isotopic turnover at both a tissue and species-specific level. This study estimated isotope turnover rates and trophic discrimination factors in four different tissues (liver, digestive tissue, muscle, and skin) with variable metabolic activity in winter flounder Pseudopleuronectes americanus using a controlled diet-switch experiment. Differences in half-lives were noted among the tissues and between the experimental diets for both δ15N and δ13C. The experimental diets of krill and mysis had variability in nutritional composition, resulting in similar turnovers in δ15N but slower turnovers in δ13C for fish fed krill. Turnovers in both δ15N and δ13C were strongly influenced by metabolism, with the contribution reaching up to 98%, as fish exhibited minimal overall growth. The results of this study demonstrate the importance of considering differences in the catabolic activity of tissue maintenance for fish exhibiting minimal growth, as well as differences in metabolic assimilation of dietary sources that vary in their protein and lipid contents. [ABSTRACT FROM AUTHOR]

Shortfin Mako Isurus oxyrinchus are ecologically and economically important apex predators throughout the global oceans. The eastern North Pacific Ocean contains several coastal nurseries for this species, where juveniles can forage and grow until venturing into offshore pelagic habitats, where seasonal migration and reproduction occurs. Opportunistically sampled vertebrae from both male and female juvenile Shortfin Mako (65.5-134.4 cm total length, neonate to age 2) were sourced from two distinct nurseries in the eastern North Pacific: the Southern California Bight (n = 12), USA, and Bahía Sebastián Vizcaíno (n = 11), Mexico. Mineralized vertebral cartilage was analyzed to determine concentrations of selected elements (Li, Mg, Mn, Zn, Sr, Ba, standardized to Ca) using laser ablation inductively coupled plasma mass spectrometry, targeting growth bands at specific life stages, including postparturition at the birth band and the recent life history of the individual at the vertebral edge. The elemental variation exhibited by these individuals over ~1 month of life before capture was explored by comparing recent vertebral concentrations, with Zn:Ca, Sr:Ca, and Ba:Ca concentrations significantly different between nurseries (Southern California Bight versus Bahía Sebastián Vizcaíno). Element variability through ontogeny was detected, as Li:Ca, Mg:Ca, and Zn:Ca concentrations were significantly different between individual past and recent vertebral bands. These findings suggest that vertebral chemistry approaches may enhance understanding of nursery habitat sources of migratory sharks. [ABSTRACT FROM AUTHOR]

Ferromagnet/nonmagnet (FM/NM) bilayer-based spin Hall nano-oscillators (SHNOs)—a sub-class of spintronic oscillator devices—have promising potential toward realizing low-power physical reservoir computing systems because of their inherent nonlinearity and miniature form factor. However, most of the studies on SHNOs indicate that an external biasing magnetic field is necessary for their operation, creating a bottleneck for their practical implementation in designing small and compact RC hardware. In this report, using micromagnetic simulation, we demonstrate biasing field-free operation of a FM/NM bilayer-based SHNO by exploiting the magnetic anisotropy. Our results reveal that the magnetic anisotropy in the FM layer provides active control over the DC tunability of auto-oscillation frequency and the threshold value of current needed for sustained auto-oscillations. We show that the increase in uniaxial anisotropy substantially modifies the spatial profile of auto-oscillation and eventually leads to the reduction in the threshold current for auto-oscillation, which could be utilized to design low-power computing hardware using SHNO devices. [ABSTRACT FROM AUTHOR]

The practice of catch and release fishing is common among anglers but has been shown to cause unintended mortalities in some species. Current post-release mortality estimates used in coastal shark stock assessments are typically derived from boat-based shark fisheries, which differ from shore-based operations that expose sharks to potentially more stressful environmental and handling conditions. Recreational post-release mortality rates in shore-based fisheries must be quantified to improve stock assessment models and to create guidelines that protect species from overexploitation. Here, we partnered with experienced anglers acting as citizen scientists to deploy pop-up satellite archival transmitting tags (PSAT, n = 22) and acceleration data loggers (ADLs, n = 22). on four commonly caught sharks including the blacktip shark (Carcharhinus limbatus, n = 11), bull shark (Carcharhinus leucas, n = 14), tiger shark (Galeocerdo cuvier, n = 6), and great hammerheads (Sphyrna mokarran, n = 2). Mortality occurred within minutes to hours post-release. If evidence of mortality occurred after normal diving behavior had been re-established for 10 days, then the mortality was considered natural and not related to the catch-and-release process. Post-release mortality estimates ranged from 0% for bull and tiger sharks to 45.5% for blacktip sharks. Of the two great hammerheads, one died within 30 minutes post-release while the other exhibited mortality characteristics 14 days after release. Moribund blacktip sharks experienced on average 3.4–4.9°C warmer water compared with survivors. Recovery periods were estimated for survivors of each species and were highly variable, differing based on duration of tag deployment. High variability in responses to capture and release between species demonstrates the need for species-specific assessments of post-release mortality in shore-based recreational fisheries. [ABSTRACT FROM AUTHOR]

According to the latest estimates, the Gulf of Maine is currently warming faster than 99% of the world's oceans. As a result, this region has become an ideal location for research into the effects that warming has on the historical fisheries that make up this ocean basin. Both white hake (Urophycis tenuis) and red hake (Urophycis chuss) are common Gulf of Maine groundfish species, distributed both inshore and offshore. While these two species are closely related phycid hakes, white hake stocks are recognized in the Gulf of Maine as rebuilding, while red hake are above target biomass levels. As a species commonly found throughout the Gulf of Maine that prefers cooler waters (4-12°C), we hypothesize the effects of climate change might influence stock behavior, such as changes in species distribution. We used generalized additive models (GAMs) to describe the relationship between hake abundance and environmental conditions using bottom temperature, bottom salinity, depth, and catch data contributed by the Maine Department of Marine Resources during their Maine - New Hampshire Inshore Trawl Surveys of the last 22 years (2000 - 2021). Our results reveal species-specific preferences for bottom temperature (white hake ~9 to ~13°C, red hake < 12°C) and depth (white hake ~55 to ~100m, red hake > ~65m), with no significant correlation to bottom salinity. Spatially over time, white hake abundance displayed a gradual center of gravity northward, while red hake rapidly increased inshore. Overall, these results highlight species-specific density changes in inshore distribution, consistent with previous studies, with considerable implications on future management strategies in this region. [ABSTRACT FROM AUTHOR]

Electrical control of photogenerated terahertz (THz) spin current pulses from a spintronic emitter has been at the forefront for the development of scalable, cost‐efficient, wideband optospintronic devices. Artificially combined ferroelectric and ferromagnet heterostructure provides the potential avenue to deterministically control the phase of THz spin current pulse through piezoelectric strain. Here, the electric field‐mediated piezoelectric strain control of photogenerated THz spin current pulse from a multiferroic spintronic emitter is demonstrated. The phase reversal of the THz spin current pulse is obtained from the combined effect of piezoelectric strain and a small magnetic field applied opposite to the initial magnetization of the ferromagnet. The piezoelectric strain‐controlled phase switching of THz spin current thus opens a door to develop efficient strain engineered scalable on‐chip THz spintronics devices. [ABSTRACT FROM AUTHOR]

Considers the arguments advanced for an expansion of academic programs incorporating service learning. Briefly describes several programs in relation to the validity of these arguments. Suggests that geography could benefit from incorporating elements of service learning in order to enhance its treatment of ethical issues. (MJP)

Understanding biological and environmental factors that influence movement behaviors and population connectivity of highly migratory fishes is essential for cooperative international management and conservation of exploited populations, like bluefin tuna. Pacific bluefin tuna Thunnus orientalis (PBT) spawn in the western Pacific Ocean and then juveniles disperse to foraging grounds across the North Pacific. Several techniques have been used to characterize the distribution and movement of PBT, but few methods can provide complete records across ontogeny from larvae to adult in individual fish. Here, otolith biominerals of large PBT collected from the western, eastern, and south Pacific Ocean, were analyzed for a suite of trace elements across calcified/proteinaceous growth zones to investigate patterns across ontogeny. Three element:Ca ratios, Li:Ca, Mg:Ca, and Mn:Ca displayed enrichment in the otolith core, then decreased to low stable levels after age 1–2 years. Thermal and metabolic physiologies, common diets, or ambient water chemistry likely influenced otolith crystallization, protein content, and elemental incorporation in early life. Although similar patterns were also exhibited for otolith Sr:Ca, Ba:Ca and Zn:Ca in the first year, variability in these elements differed significantly after age-2 and in the otolith edges by capture region, suggesting ocean-specific environmental factors or growth-related physiologies affected otolith mineralization across ontogeny. [ABSTRACT FROM AUTHOR]

The article traces the post-war history of the British hospital contributory schemes, which had developed during the inter-war years to the point where, through the accumulation of small weekly contributions from a mass membership, they provided substantial proportions of hospital income. A minority of contributory schemes remained in existence post-1948, but their subsequent development has received little attention. Some evolved into provident associations offering private health insurance; others remained committed to the provision of low-cost benefits to a blue-collar clientele, and continued to be known as hospital contributory schemes. This article outlines the principal features of the contributory schemes' contemporary history. We first explore why many schemes decided to continue in existence. The next section uses national and individual scheme records to delineate the market niche which they captured and to investigate their role in post-war health provision, relative to the state system. In particular we trace the decline of convalescent home benefit, and the gradual trend towards a more uniform benefit package, of which optical and dental grants were the most popular. We then survey patterns of membership and account for the main trends in support for cash plan products since 1950. Finally, we ask to what extent the schemes were able to retain their character as a 'movement' with distinctive mutualist and charitable features, particularly in the more competitive environment of the later twentieth century.

There has recently been much debate about the influence of social capital on health outcomes. In particular it has been suggested that levels of social capital vary from place to place and that such variations may account for previously unexplained between-place variations in health outcomes. As yet few studies exist of the influence of small-area variations in social capital on health outcomes. One reason for this is the difficulty of obtaining indicators for small areas such as electoral wards in England, and we describe a method used to derive what we term 'synthetic estimates' of aspects of social capital by linking coefficients produced from multi-level analyses of national survey datasets to census data. We produce estimates for electoral wards in England and apply these in multi-level models of our response variable, the probability of survival of individuals surveyed in the Health and Lifestyle Survey of England. We report various combinations of models incorporating individual attributes, health-related behaviours, area measures of deprivation, and area measures of social capital. Our overall conclusion is that we find little support, at this spatial scale, for the proposition that area measures of social capital exert a beneficial effect on health outcomes. Keywords: Social capital; Place; Health inequalities; Health and Lifestyle Survey; Multi-level modeling; UK

Presents a tribute to Dan Davidson, American Department of Foreign Language's (ADFL) 1997 honoree as an outstanding educator, focusing on Davidson's work to expand Russian studies nationwide and forge ties between U.S. Russianists and Russia itself over the past decades, beginning with the post-Sputnik era. Davidson was able to go beyond the Iron Curtain and begin Russia-based study programs for young Americans. (SM)

General practitioner fundholding is often represented as one of the more successful elements of the 1989/90 Conservative reforms of the UK National Health Service (NHS). Successive annual `waves' of fundholding practices were approved from 1990 through to 1997 and, over time, the initiative came to involve some 50% of UK general practitioners. Fundholding is known to have had a strong regional geography that changed with evolving fundholding eligibility criteria. Further, there have been persistent allegations that fundholding tended to occur disproportionately in areas of higher social status. Past studies of fundholding have tended to consider single waves or the overall impact of the initiative rather than its development over time. They have also tended to work at a single geographic scale or through single-region case studies when exploring the statistical regularities underlying the uptake of fundholding. Using multilevel analysis, this paper seeks to enhance understanding of fundholding through an examination of the interaction of district health authority and practice characteristics across all implemented waves for all general medical practices in England and Wales. We conclude that wave mattered on a national scale, that deprivation was relatively unimportant and that there were certain types of area that exhibited persistent but unexpected high uptake. Keywords: Primary care; Geography of health care; General practice fundholding; Multilevel models; General practice; UK