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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.
Fertiliser input in annual cropping systems can benefit crops and weeds. The effects of organic and inorganic fertilisers on weed species composition were evaluated across two agroecological zones in Eswatini: the Highveld and the Middleveld. Weed field surveys and weed seed bank studies were conducted over two cropping seasons, 2020/2021 and 2021/2022, in fields managed by smallholder farmers practising maize and cattle production. Fertiliser regimes were cattle manure only, cattle manure plus inorganic fertiliser, and inorganic fertiliser only, replicated six times in each region. The weed survey was conducted using three 25-m transects, and the weed seed bank was assessed at sampling depths of 0–10 and 10–20 cm. Results showed that cattle manure only and cattle manure plus inorganic fertiliser regimes had higher species richness and diversity than the inorganic fertiliser only regime. However, weed seed distribution did not differ between sampling depths or fertiliser regimes. Twelve weed species, including bermudagrass, crabgrass, and goosegrass, were key contributors to the differences in species composition between fertiliser regimes and agroecological zones, and were the most prevalent weeds in the seed bank. The study established that fertiliser type influences weed species composition and diversity. Proper cattle manure composting is essential to mitigate weed proliferation and enhance sustainable maize production. These findings demonstrate the need for integrated weed management and fertiliser strategies to improve crop yield and agricultural sustainability for smallholder farmers.
We study the behaviour of a thin fluid filament (a rivulet) flowing in an air-filled Hele-Shaw cell. Transverse and longitudinal deformations can propagate on this rivulet, although both are linearly attenuated in the parameter range we use. On this seemingly simple system, we impose an external acoustic forcing, homogeneous in space and harmonic in time. When the forcing amplitude exceeds a given threshold, the rivulet responds nonlinearly, adopting a peculiar pattern. We investigate the dance’ of the rivulet both experimentally using spatiotemporal measurements, and theoretically using a model based on depth-averaged Navier–Stokes equations. The instability is due to a three-wave resonant interaction between waves along the rivulet, the resonance condition fixing the pattern wavelength. Although the forcing is additive, the amplification of transverse and longitudinal waves is effectively parametric, being mediated by the linear response of the system to the homogeneous forcing. Our model successfully explains the mode selection and phase-locking between the waves, it notably allows us to predict the frequency dependence of the instability threshold. The dominant spatiotemporal features of the generated pattern are understood through a multiple-scale analysis.
We study the well-posedness of solutions to the general nonlinear parabolic equations with merely integrable data in time-dependent Musielak–Orlicz spaces. With the help of a density argument, we establish the existence and uniqueness of both renormalized and entropy solutions. Moreover, we conclude that the entropy and renormalized solutions for this equation are equivalent. Our results cover a variety of problems, including those with Orlicz growth, variable exponents and double-phase growth.
In this work we present a framework to explain the prediction of the velocity fluctuation at a certain wall-normal distance from wall measurements with a deep-learning model. For this purpose, we apply the deep-SHAP (deep Shapley additive explanations) method to explain the velocity fluctuation prediction in wall-parallel planes in a turbulent open channel at a friction Reynolds number ${\textit{Re}}_\tau =180$. The explainable-deep-learning methodology comprises two stages. The first stage consists of training the estimator. In this case, the velocity fluctuation at a wall-normal distance of 15 wall units is predicted from the wall-shear stress and wall-pressure. In the second stage, the deep-SHAP algorithm is applied to estimate the impact each single grid point has on the output. This analysis calculates an importance field, and then, correlates the high-importance regions calculated through the deep-SHAP algorithm with the wall-pressure and wall-shear stress distributions. The grid points are then clustered to define structures according to their importance. We find that the high-importance clusters exhibit large pressure and shear-stress fluctuations, although generally not corresponding to the highest intensities in the input datasets. Their typical values averaged among these clusters are equal to one to two times their standard deviation and are associated with streak-like regions. These high-importance clusters present a size between 20 and 120 wall units, corresponding to approximately 100 and 600 $\unicode{x03BC} \textrm {m}$ for the case of a commercial aircraft.
For a group G and $m\ge 1$, $G^m$ denotes the subgroup generated by the elements $g^m$, where g runs through G. The subgroups not of the form $G^m$ are called nonpower subgroups. We extend the classification of groups with few nonpower subgroups from groups with at most nine nonpower subgroups to groups with at most 13 nonpower subgroups.
Recent developments in spatial audio and immersive technologies have expanded creative possibilities for composers and sound artists. This article presents a novel prototype of a spherical microphone with an ellipsoid casing and ten motorised condenser capsules, each capable of real-time adjustment of orientation and polar pattern. Unlike fixed-pattern or conventional ambisonic arrays, this design enables dynamic control over spatial coverage and directivity, offering new opportunities for multichannel recording, live performance and interactive sound art. While software-based spatialisation offers some flexibility, physical reconfiguration of capsules provides superior responsiveness and avoids latency, phase artefacts or resolution loss. This is especially critical in performance contexts where immediate acoustic adaptation is required. The system allows direct manipulation of capsule parameters during rehearsal or installation, effectively transforming the microphone into a performative instrument. The article compares the prototype with existing commercial ambisonic microphones, highlighting its distinctive advantages in workflow and compositional strategy. Use-case scenarios demonstrate how real-time control over spatial parameters enhances both technical precision and artistic expressiveness. The article concludes with a discussion of future directions, including collaborative testing with practitioners and integration into creative environments where spatial transparency, fidelity and interactivity are essential.
Under the Generalised Riemann Hypothesis (GRH), any element in the multiplicative group of a number field K that is globally primitive (i.e., not a perfect power in $K^*$) is a primitive root modulo a set of primes of K of positive density.
For elliptic curves $E/K$ that are known to have infinitely many primes ${\mathfrak{p}}$ of cyclic reduction, possibly under GRH, a globally primitive point $P\in E(K)$ may fail to generate any of the point groups $E(k_{\mathfrak{p}})$. We describe this phenomenon in terms of an associated Galois representation $\rho_{E/K, P}\,:\,G_K\to\mathrm{GL}_3({\widehat {{\mathbf{Z}}}})$, and use it to construct non-trivial examples of global points on elliptic curves that are locally imprimitive.
This study investigates the wake dynamics of a wall-mounted square cylinder with an aspect ratio of 2, subjected to varying inflow turbulence intensities, employing high-fidelity large-eddy simulation complemented by spectral proper orthogonal decomposition. The simulations are conducted at a Reynolds number of 43 000. A synthetic momentum source term is integrated within the Navier–Stokes equations to generate turbulence consistent with the von Kármán spectrum. Four inflow cases, comprising an undisturbed inflow and three disturbed inflows with turbulence intensities of 10 %, 20 % and 30 %, are examined to elucidate their impact on vortex shedding, shear-layer behaviours and coherent structures. Results demonstrate that increased turbulence intensity significantly modifies vortex coherence, suppresses recirculation regions, promotes earlier shear-layer reattachment on the top surface and leads to reattachment of the shear layer on the side surface. Spectral proper orthogonal decomposition analysis, conducted on 17 orthogonal planes in the streamwise (x), wall-normal (y) and spanwise (z) directions, reveals two dominant energetic frequencies: a primary vortex-shedding frequency around a Strouhal number of 0.084, and a secondary high frequency associated with Kelvin–Helmholtz instabilities. The imposed turbulence effectively redistributes spectral energy, diminishing the coherence and altering the spatial organisation of vortical structures. These findings enhance fundamental understanding of turbulent wake dynamics and flow–structure interactions in bluff-body flows.
The regulation of groundwater remains underdeveloped globally and often lags behind the domestic governance of surface water. As a result, groundwater is often subject to unfettered extraction, uses, and contamination. A clear understanding of ownership is central to the success of domestic regulations. However, the types of ownership regime in place in nations around the world are poorly documented in the academic literature. This study addresses that gap through a comparative analysis of domestic groundwater ownership regimes across ten jurisdictions in nine countries spanning five continents. It identifies three dominant models of groundwater ownership: private ownership, public ownership, and non-ownership with public oversight. It then examines how these ownership doctrines impact key dimensions of groundwater governance, including the nature and transferability of the ownership right, the level of government at which regulation takes place, implications for rights of use, and interactions with customary and Indigenous rights. Doing so offers unique insight into how nations with different legal traditions, governance structures, and customary practices address the ownership of groundwater resources. It also suggests that different ownership (and non-ownership) models can have distinct implications for other aspects of groundwater governance.
This musing explores the neoliberalization of addiction recovery and its implications for queer subjects, their affects and attachments. The author examines the ways in which neoliberal ideology usurps the critical potential of trauma-informed theory and practice in the context of addiction recovery, and offers a queer reading of the affects of addiction experienced as a negotiation of this tension. How do queer experiences both challenge and reflect the neoliberal ethos informing contemporary frameworks for addiction recovery? Through a media analysis of the Netflix mini-series, Feel Good, which depicts an experience of queer addiction and codependency, the author illustrates how a representation of queer affect is mediated by neoliberal formulations of subjectivity and pathology. A theoretical framework combining critical addiction studies and feminist affect studies is employed to examine the challenges and possibilities for queer subjects whose experiences at the intersection of systemic oppression and addictive attachment have the potential to subvert the neoliberalization of addiction recovery.