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The incorporation of trace metals into land snail shells may record the ambient environmental conditions, yet this potential remains largely unexplored. In this study, we analyzed modern snail shells (Cathaica sp.) collected from 16 sites across the Chinese Loess Plateau to investigate their trace metal compositions. Our results show that both the Sr/Ca and Ba/Ca ratios exhibit minimal intra-shell variability and small inter-shell variability at individual sites. A significant positive correlation is observed between the shell Sr/Ca and Ba/Ca ratios across the plateau, with higher values being recorded in the northwestern sites where less monsoonal rainfall is received. We propose that shell Sr/Ca and Ba/Ca ratios, which record the composition of soil solution, may be controlled by the Rayleigh distillation in response to prior calcite precipitation. Higher rainfall amounts may lead to a lower degree of Rayleigh distillation and thus lower shell Sr/Ca and Ba/Ca ratios. This is supported by the distinct negative correlation between summer precipitation and shell Sr/Ca and Ba/Ca ratios, enabling us to reconstruct summer precipitation amounts using the Sr/Ca and Ba/Ca ratios of Cathaica sp. shells. The potential application of these novel proxies may also be promising for other terrestrial mollusks living in the loess deposits globally.
Convection in planetary environments is often modelled using stress-free boundary conditions, with diffusion-free geostrophic turbulence scalings frequently assumed. However, key questions remain about whether rotating convection with stress-free boundary conditions truly achieves the diffusion-free geostrophic turbulence regime. Here, we investigated the scaling behaviours of the Nusselt number ($Nu$), Reynolds number (${Re}$) and dimensionless convective length scale ($\ell /H$, where $H$ is the height of the domain) in rotating Rayleigh–Bénard convection under stress-free boundary conditions within a Boussinesq framework. Using direct numerical simulation data for Ekman number $Ek$ down to $5\times 10^{-8}$, Rayleigh number $Ra$ up to $5\times 10^{12}$, and Prandtl number $Pr = 1$, we show that the diffusion-free scaling of the heat transfer $Nu - 1 \sim Ra^{3/2}\, Pr^{-1/2}\, Ek^2$ alone does not necessarily imply that the flow is in a geostrophic turbulence regime. Under the stress-free conditions, ${Re}$ and $\ell /H$ deviate from the diffusion-free scalings, indicating a dependence on molecular diffusivity. We propose new non-diffusion-free scaling relations for this diffusion-free heat transfer regime with stress-free boundary conditions: $\ell /H \sim Ra^{1/8}\, Pr^{-1/8}\, Ek^{1/2}$ and ${Re} \sim Ra^{11/8}\, Pr^{-11/8}\, Ek^{3/2}$. Our findings highlight the need to assess both thermal and dynamic characteristics to confirm geostrophic turbulence.
We investigate radial and non-radial solutions to a class of (p, q)-Laplace equations involving weights. More precisely, we obtain existence and multiplicity results for nontrivial nonnegative radial and non-radial solutions, which extend results in the literature. Moreover, we study the non-radiality of minimizers in Hénon type (p, q)-Laplace problems and symmetry-breaking phenomena.
Dedicated to Professor Pavel Drábek on the occasion of his seventieth birthday
In the highlands of northern Chile, research on industrial mining camps and agropastoral sites (estancias) shows the relevance of a contemporary archaeology perspective for studying the impacts of capitalist expansion, ruination and deindustrialisation for local Indigenous communities.
Social anxiety disorder (SAD) is one of the most prevalent co-occurring conditions amongst cognitively unimpaired autistic people. The evidence-based treatment for social anxiety known as cognitive therapy for SAD (CT-SAD) may to an extent be beneficial to autistic people, but adaptations for autistic people are recommended to increase its effectiveness. The present study aimed to co-produce and pilot an adapted SAD treatment protocol for autistic people based on the Clark and Wells (1995) model, including assessing its feasibility and acceptability. A bespoke 12-week CBT online group intervention was created to meet the needs of autistic people with a diagnosis of SAD. The treatment protocol was created collaboratively with autistic people. It was piloted with seven adult participants (three males, four females) with autism or self-identified autism who completed the group intervention targeting SAD symptoms. With regard to feasibility, we met our initial aims of recruiting our intended sample size of a minimum of six participants for the intervention with an attendance rate of at least 80% of sessions. The excellent completion and attendance rates, respectively 100% and 95%, indicate that the intervention was acceptable to our participants. These findings extend previous research and support the continued adaptation of CBT interventions for autistic people. Furthermore, the evidence of feasibility indicates that further study to evaluate the efficacy of this group intervention is warranted.
Key learning aims
(1) To reflect on social anxiety, autism and identify ways to improve the delivery of cognitive therapy for autistic people.
(2) To identify useful adaptations to cognitive therapy for autistic people.
(3) To learn how to deliver group cognitive therapy remotely for autistic people who present with social anxiety.
This article addresses classical issues in conversation analysis related to the overall structural organization of social interaction, achieved through opening and closing sequences. While the integrity and autonomy of social interaction are most often oriented to by participants in single interactions, the study of some institutional interactions shows that forms of porosity between encounters do exist, in which one encounter impinges on another. This is the case of encounters-in-a-series, in which a new encounter is opened as the previous is not yet closed. The article examines interactions in which participants orient to the preservation of the integrity of successive encounters, contrasted with cases in which the initiation of the opening of a new encounter happens during or before the closing of the previous, and discusses how and when this is treated as normatively delicate or not, within the participants’ local endogenous analysis of the overall structural organization of the interaction. (Social interaction, conversation analysis, multimodality, overall structural organization, opening, closing, encounters-in-a-series, porosity)
Cystic echinococcosis (CE) is a significant zoonotic helminthic disease with considerable public health and economic impact in endemic regions. We aimed to analyse the climatic and environmental factors affecting the human CE cases in North Khorasan Province, northeast Iran. Using a geographic information system, we map the addresses of 316 hospitalised CE patients from 2012 to 2022 and examined the influence of climatic variables, altitude, and land cover on CE case distribution. Data were analysed using logistic regression models. Most patients were female (58.9%) and aged 21–60 years (67.4%), with liver involvement being the most common (57.3%). The multivariate model identified urban settings, irrigated and dry farms, soil temperature, and humidity as the most important geoclimatic determinants, respectively. In contrast, gardens, moderate and excellent rangelands, minimum, maximum, and mean air temperatures, and rainfall were only found to be significant factors in univariate models. High-risk areas for CE include urban and suburban regions, surrounding fields, and pastures where stray dogs and wild canids roam, livestock husbandries are present, and residents consume unsanitised vegetables. Additionally, areas with lower soil and weather temperatures and higher humidity conditions that may enhance the survival of E. granulosus eggs dispersed by canids were identified as high-risk zones. Health managers can use these findings to prioritise control programs and allocate limited resources to these areas, ultimately reducing the future incidence of CE.
In turbulent pipe flows, drag-reducing polymers are commonly used to reduce skin-friction drag; however, predicting this reduction in industry applications, such as crude oil pipelines, remains challenging. The skin-friction coefficient ($C_f$) of polymer drag-reduced turbulent pipe flows can be related to three dimensionless parameters: the solvent Reynolds number ($Re_s$), the Weissenberg number ($Wi$) and the ratio of solvent viscosity ($\eta _s$) to zero-shear-rate viscosity ($\eta _0$), denoted as $\beta$. The function that relates these four dimensionless numbers was determined using experiments of various pipe diameters ($D$), flow velocities ($U$) and drag-reducing polyacrylamide solutions. The experiments included measurements of streamwise pressure drop ($\Delta P$) for determining $C_f$, and measurements of shear viscosity ($\eta$) and elastic relaxation time ($\lambda$). This experimental campaign involved 156 flow conditions, each characterised by distinct values for $C_f$, $Re_s$, $Wi$ and $\beta$. Experimental results demonstrated good agreement with the relationship: $C_f^{-1/2} = \widehat {A}\log _{10}(Re_sC_f^{1/2})+\widehat {B}$, where $\widehat {A} = 27.6(Wi \beta )^{0.346}$ and $\widehat {B} = 122/15-58.9(Wi \beta )^{0.346}$. Based on this relationship, onset and maximum drag reduction are predicted to occur when $Wi \beta$ equals $3.76 \times 10^{-3}$ and $3.40 \times 10^{-1}$, respectively. This function can predict $C_f$ of dilute polyacrylamide solutions based on predefined parameters (bulk velocity, pipe diameter, density, solvent viscosity) and two measurable rheological properties of the solution (shear viscosity and elastic relaxation time) with an accuracy of $\pm 9.36$ %.
Disaster risk reduction measures are now being developed based on social vulnerability. This study aimed to identify socially vulnerable areas to disasters in Razavi Khorasan Province, Iran.
Methods
The research utilized a mixed method approach conducted in 2 stages. First, a vulnerability index was created using 8 sub-indices, and the value of the index was calculated for each of the 91 rural districts in the study area. In the second stage, spatial analysis using Anselin’s Local Moran’s I was performed to identify the most vulnerable districts.
Results
Results indicated that 40 of 91 districts, covering 49% of the total area, had high social vulnerability to disasters. Anselin’s Local Moran’s I analysis identified 2 high-high clusters consisting of 5 districts. The study also found that areas with higher social vulnerability were more susceptible to natural hazards such as floods and earthquakes.
Conclusions
Nearly half of the studied areas exhibited a high level of social vulnerability and were at risk of natural disasters. Implementing general measures to improve the socio-economic status of the population, such as increasing education and income levels, along with specific actions like assisting vulnerable populations in relocating to safer areas, can help mitigate disaster risks.