We investigated the epizoic diatoms colonizing the carapace of the spider crab Hyastenus hilgendorfi inhabiting Lake Timsah in the Suez Canal. A total of 63 individuals, free of macro-epibionts, were examined to assess the diversity, abundance, and seasonal dynamics of their associated diatom communities. A total of 61 diatom taxa belonging to 31 genera were recorded, with raphid pennate diatoms being the most dominant, particularly Navicula lanceolata. Diatom density and diversity exhibited clear seasonal variation, where Summer had the highest richness and Spring the highest cell densities. Overall, males hosted more diatom taxa than females, however, sex-specific differences fluctuated seasonally. The cluster analysis revealed distinct diatom assemblages between sexes and seasons, showing subtle but significant variation in epibiont structure. These findings provide the first detailed characterization of epizoic diatom assemblages on H. hilgendorfi. They suggest that seasonal variations in diatom communities may influence the crab’s camouflage effectiveness by altering biofilm characteristics which facilitate macro-epibiont settlement.

Given a number field F with ring of integers $\mathcal {O}_{F}$, one can associate to any torsion free subgroup of $\operatorname {SL}(2,\mathcal {O}_{F})$ of finite index a complete Riemannian manifold of finite volume with fibered cusp ends. For natural choices of flat vector bundles on such a manifold, we show that analytic torsion is identified with the Reidemeister torsion of the Borel-Serre compactification. This is used to obtain exponential growth of torsion in the cohomology for sequences of congruence subgroups.

It is often thought that compulsory retirement funding gains support from paternalistic considerations. This paper examines this claim. I argue that compulsory retirement funding is more coherent when understood as an attempt at temporal smoothing than counterfactual insurance. An implication is that any paternalistic case for retirement funding faces problems that are more severe than they would be if compulsory retirement funding were insurance. I label these the problems of ‘inverted bias’ and of the ‘arbitrariness of income from labour’. The paper then makes some suggestions about how these points about paternalism bear on the problem of justice in retirement funding.

Between 1898 and 1923, a series of disputes erupted among fishing communities in the British Gold Coast Colony (modern-day Ghana) following the introduction of larger and more productive sea fishing nets. All along the coast, fishers debated the environmental and economic consequences of adopting the nets, which debates shifted across African and colonial forums. Focusing on these disputes, this article interrogates the ways in which sites of fishing innovations and experimentation became sites of intense conflict and negotiation throughout the Gold Coast Colony as different groups debated and contested technological change. In the process, voices advocating for caution within the fishing industry were effectively marginalised through the manoeuvring of net advocates while the introduction of colonial arbitration within the realm of fisheries offered new challenges to the authority of African leaders within the marine space.

This paper investigates the everyday use of coins at the Roman Red Sea ports of Berenike and Myos Hormos, challenging their conventional interpretation as mere indicators of trade prosperity. Adopting a contextualized approach, the paper analyzes coin finds alongside non-numismatic evidence – including ceramics, botanical and zoological remains, and epigraphic records – to uncover their role in daily economic activities. The study demonstrates how coins functioned across diverse settings such as marketplaces, industrial zones, religious sites, and residential areas, highlighting their integration into the economic, social, and cultural fabric of the ports. Beyond serving as a medium of exchange, coins played crucial roles in taxation, service payments, and religious offerings. By reconstructing the transactional dynamics of the ancient ports, the paper provides new insights into the interactions between residents and visitors, enriching our understanding of daily life in these vibrant hubs through a holistic archaeological perspective.

This study examines the use of English on signage in the areas surrounding two U.S. military bases in Japan, Yokosuka Navy Base and Yokota Air Base, highlighting the diverse functions of English that emerge through interactions between American residents and Japanese locals. In these areas, including streets that have become tourist destinations for Japanese visitors, various commercial establishments coexist, some offering authentic products and services for Americans, and others commodifying American culture for Japanese tourists. Within these public spaces, English signage, along with other semiotic resources, plays a central role in shaping a uniquely commodified environment infused with American culture. The study identifies two key features of English signage that distinguish these areas from other parts of Japan: (1) the prominence of informational English signage targeting Americans, such as monolingual English traffic signs and church signs, which reflects the dense American population; and (2) the symbolic use of English by Japanese shop owners, which do not signal modernity or globalization as English signage typically does elsewhere in Japan, but instead commodifies American culture to attract Japanese tourists. These uses of English on signage, alongside other semiotic materials, shape a unique visual and cultural landscape, underscoring the multifaceted roles of English in non‑English‑speaking countries like Japan, including both the ‘authentic’ use of English in communication with Americans and the ‘commodified authenticity’ conveyed through English employed by Japanese shop owners to appeal to Japanese audiences.

This study provides the first results on the population dynamics of Sphyraena sphyraena (Linnaeus, 1758) in the western Mediterranean. Otoliths and scales reading were used for its age and growth investigation in Eastern coast of Algeria. The monthly evolution in marginal increment data of scales and otoliths revealed that only one annulus is formed per year in February. Fish length and radii of the scales or otoliths were closely correlated. Both methods showed four age groups. ANOVA test (P < 0.05) revealed insignificant differences between both estimates of length at age results. Growth parameters estimated using length-at-age data from both methods confirming the age determination results. The total mortality (Z ), natural mortality (M ), and fishing mortality (F ) were estimated at 1.19 year−1, 0.826 year−1, and 0.363 year−1, respectively. The growth performance index (Ø ) was 2.57. The estimated exploitation ratio (E ) was 0.305. The length–weight relationship is EW = 0.0104 TL2.702, showed that the growth rates were negative allometric. The results revealed the compatibility of otoliths and scales reading for assessment studies of Sphyraena sphyraena .

In Brazil, laws are being adopted prohibiting the use and distribution of non-recyclable plastic bags and encouraging the use of recyclable, biodegradable and bioplastic bags. However, there is no specific standard method in Brazil to inspect the carbon content of bioplastics. This work aims to implement the sample preparation for radiocarbon biogenic fraction determination in bioplastics in the new radiocarbon laboratory at the Federal University of Bahia (LAPA14C-UFBA). Six plastic samples from Brazilian markets with bio-based seals were collected in regular Brazilian markets, four bags and two tubes. All samples were combusted and graphitized in the LAPA14C-UFBA and the graphites were measured at the Radiocarbon Laboratory (LAC-UFF). The biogenic fraction analysis followed the Standard Test Methods for Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis (ASTM D6866-24). Since the bioplastic manufactured in Brazil is derived from sugarcane, a C4 plant where δ13C values are different from those of petroleum-derived plastic, the biogenic fraction was obtained via the isotopic mixture equation. The results showed a robust direct correlation (r=0.998) between the fractions obtained by the two methods, indicating that δ13C analysis can be used, in this case, as an alternative in determining the biogenic fraction of plastics. From the results obtained, four out of the six samples analyzed showed biogenic fraction values below the 51% required by the I’m Green label, with values ranging from 4% to 43%, according to the δ3C and 14C analysis, showing the efficiency of both techniques in determining the biogenic fraction.