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In this article, we investigate necessary and sufficient conditions on the perturbation ρ for the existence of positive least energy solutions of the critical singular semilinear elliptic equation $ -\Delta u = \frac{|u|^{2^{*}(s)-2}}{|x|^s}u + \rho(u) $ with Dirichlet boundary condition in a bounded smooth domain in $\mathbb R^n$ containing the origin, where $2^*(s)=\frac{2(n-s)}{n-2}$, $0\leq s \lt 2 \lt n$. We show that the almost necessary and sufficient condition obtained for the case s = 0 in [1] differs conceptually when $0 \lt s \lt 2$.
Loess–paleosol outcrops were logged and dated to trace loess cover during the Pleistocene in a low-elevation mountainous area. The exposed successions were a maximum of 15 m thick and stratigraphically fragmentary. Still, results suggest that loess was deposited in all climatically suitable periods within the limits of the dating methods (ca. 400 ka), and probably also beyond this. Luminescence measurements provided numerical ages from ca. 18 ka to ca. 200 ka and minimum ages of up to >267 ka. Loess accumulation was also active during the relatively mild MIS 3. A new occurrence of a well-preserved Quaternary tephra was documented, correlative with the middle Pleistocene Bag Tephra (ca. 340 or 368 ka). The dating of loess successions provided valuable data on geomorphic evolution as well, identifying hydrological changes and constraining a maximum incision and uplift rate of 0.008–0.035 mm/yr for the western part of the area. The low thickness of loess–paleosol successions and the stratigraphic gaps seem to be a consequence of repeated erosion during the Pleistocene rather than a result of non-deposition. The mountains probably have been covered with loess for most of the time during the past 1 Ma. This should be taken into consideration in studies influenced by the loess cover of an area.
Superadas las crisis sociales y políticas que tuvieron lugar en las décadas finales del período Preclásico, nuevas entidades comienzan a emerger en el panorama geopolítico de las tierras bajas mayas. En el caso del Petén campechano, el descubrimiento de sitios arqueológicos con vestigios de estructuras defensivas y monumentos pétreos permite inferir la configuración de una nueva realidad en la que entidades como Oxpemul parecen comenzar a despuntar. En este sitio destacan dos monumentos que preservan registro iconográfico de cautivos, las Estelas 22 y 23; estas exhiben patrones iconográficos típicos del Clásico temprano, entre los que destacan tres figuras desnudas e hincadas. Con la toma de nuevas fotografías diurnas y nocturnas de las estelas y la utilización de la herramienta computacional Reflectance Transformation Imaging, se presentan nuevas interpretaciones de los monumentos de Oxpemul; además, a través de los nuevos análisis iconográficos se proponen nuevas consideraciones sobre las dinámicas sociopolíticas regionales durante los contextos tempranos en los que Oxpemul parece jugar un papel destacable.
Social construction theory postulates that policy outcomes depend on whether target groups are imagined by the public as deserving or undeserving. However, recent evidence demonstrates that the constructions in question are contentious rather than uniformly shared. This article applies the conjoint-experimental method to measure the social construction of immigrant (il)legality and to assess its political implications. We demonstrate that it is multidimensional because the absence of legal status is associated with receipt of government benefits, Hispanic origin, police record, poor English fluency, and less education. We also show that whereas the receipt of government benefits is not associated with the absence of legal status among most respondents, individuals who hold this association support stricter immigration-enforcement policies. Our findings corroborate the social construction approach but also indicate that researchers may want to measure multiple dimensions of target-group constructions in addition to deservingness.
Metal pollution is a major global issue in aquatic environments, affecting environmental quality and potentially altering host–parasite dynamics. This study evaluates the buffering role of a larval trematode Himasthla sp. under experimental conditions to test the effect of copper (Cu) exposure on the survival of the marine snail Echinolittorina peruviana. Snails were collected from intertidal rocky pools over a two-month period from Coloso (23°45’S, 70°28’W), northern Chile, and identified as parasitized or unparasitized. Both groups were then exposed to Cu concentrations (3 and 6 mg/L). Kaplan–Meier curves were used to determine the percentage of survival over time and the respective confidence intervals (CI). A nested ANOVA was conducted to assess whether rediae abundance per snail varied by experiment time, snail status, and Cu concentration. Snail survival was affected by both Cu-concentrations, but the effect was greater at 6 mg/L. At 3 mg/L, 57% (CI: 49.9–66.6%) of unparasitized snails were alive at 192 h, while 56% (CI: 46.6–67.4%) of parasitized snails survived at 216 h. At 6 mg/L, 42% (CI:35-51%) of unparasitized snails survived at 192 h, while 48% of parasitized snails survived at 216 h (CI:39-59%). Regardless of Cu concentration, after 240 h, all unparasitized snails had died, while 15% of parasitized snails remained alive. Dead snails harboured 125±53 rediae, while survivors had 194±73 rediae, with no significant differences between treatments. Our results show that parasitized snails survived longer than unparasitized snails, suggesting a trade-off between parasitism and host survival in polluted environments.
What is the current state of Comparative Regionalism (CR) as a field of research? Since its inception, CR has suffered from a chasm between those who take European integration as the model for conceptualising, theorising, comparing, and designing regionalism worldwide, and the critics, who reject EU-centrism in favour of more contextualised approaches focusing on the Global South. This paper challenges this characterisation by showing how CR has fundamentally changed in the last decade or so. We detail three ‘silent’ transformations: (i) conceptually, scholars disaggregate regionalism into specific components, rendering systematic comparison more tractable and less individual case-centric; (ii) theoretically, scholars develop frameworks that build on general social science theories and actively seek to move beyond EU-centrism; and (iii) methodologically, scholars use more rigorous comparative designs and a broader range of data. These changes, we suggest, indicate a ‘mainstreaming’ of CR, with attendant benefits and costs.
We examine whether the heterogeneity of expectations is associated with idiosyncratic variations in experience. Combining household survey data and administrative data from the Netherlands, we find that given market development, households’ expectations about house price changes vary with their individual experience. This association is related to the use of information conveyed by experience, which varies in terms of informativeness, recency, and household sophistication. Finally, we find that individual experience also explains how far house price expectations deviate from realized house prices and that it may affect household behavior. Our findings elucidate the role that individual experience plays in expectation formation.
Although both butterflies and dragonflies are four-winged insects, their wing geometries and kinematics differ significantly. Butterflies have a much narrower gap between their forewing and hindwing than dragonflies. While previous research has extensively investigated the forewing–hindwing interactions in dragonfly flight, this work focuses on their interactions in butterfly flight. The interactions are studied based on numerical simulations of the Navier–Stokes equations around a butterfly-inspired flapping wing with an adjustable slot, representing the narrow gap between the forewing and hindwing. The slot is controlled by a dihedral angle between the forewing and hindwing. The lift coefficients of wings with different slot sizes and locations are investigated in detail. The results show that the forewing–hindwing interactions can significantly enhance the lift if the slot is properly configured. When the slot is configured by elevating the forewing at a 10-degree dihedral angle relative to the hindwing during flapping flight, the wing generates over 20 % more lift than the model without a slot. The streamwise ram effect and tip-vortex capture are shown to be responsible for the lift enhancement by using a lift decomposition formula. The streamwise ram effect reduces the streamwise velocity beneath the forewing, decreasing the negative vortex lift associated with spanwise vorticity. The tip-vortex capture enhances the positive vortex lift associated with streamwise vorticity when the hindwing captures the tip vortex shedding from the forewing.
Grazing management is an important component affecting pasture stability, but the underlying demographic mechanisms remain poorly understood in mixed-species systems. This three-year study investigated how grazing height (15 and 20 cm pre-grazing) and strategic spring defoliation (7 cm) influence stability in mixed pastures composed of complementary C3/C4 grasses (Lolium arundinaceum and Cenchrus clandestinus). Utilising demographic and tiller size/density relationship theories, we examined population dynamics to better understand pasture stability. The results indicated that height management significantly affected the demographic traits, with shorter grazing (15 cm) increasing tiller emergence and population density while reducing individual tiller weight (TW). In addition, higher tiller population density (TPD) and lower TW were observed in the shorter treatments. Despite these contrasting responses, the mixed pasture maintained consistent stability across treatments through compensatory relationships between tiller traits. The stability index remained close to 1 (0.956 ± 0.02) regardless of management, demonstrating robust demographic equilibrium. Individual species showed distinct seasonal stability patterns – L. arundinaceum dominating in winter and C. clandestinus in spring and summer – yet their complementary growth maintained year-round system stability. The self-thinning law effectively revealed stable size-density compensation across treatments, suggesting its utility for assessing mixed sward persistence. These findings demonstrate that mixed pastures can maintain demographic stability under varying grazing regimes through species complementarity and population compensatory mechanisms.
We synthesized pre-last glacial maximum pollen records to reconstruct North American pollen diversity since ca. 130 ka. Using taxonomic diversity (a measure of the number and abundance of taxa) and functional diversity (a measure of the number and abundance of different phenotypes) we identified temporal and spatial diversity trends for six North American bioregions: Arctic, Intermountain West, Mexico, Pacific Northwest, Southeast, and Yucatán. Reconstructed taxonomic temporal and spatial trends vary among bioregions, with regional diversity patterns captured in the functional metric, suggesting shifts in species composition coincide with shifts in ecosystem function. However, significant shifts in taxonomic pollen diversity differed in frequency, magnitude, and timing from their functional counterparts. Variations in both regional taxonomic and functional diversity response to global and regional temperature trends were evident, suggesting temperature alone does not fully explain changes in species composition. Regional richness estimates exhibited higher stability relative to the weighted diversity estimates indicating low levels of species turnover through Late Quaternary warming–cooling phases. Shifts in regional diversity did not predictably respond to stadial and interstadial transitions. Instead, North American patterns of plant diversity over the last ca. 130 ka differ geographically, likely responding to regional rather than global climate change.
The extant literature on diamond industries in Africa has predominantly focused on men, with few attempts to examine the industry from a gendered lens. I trace women and highlight their gendered roles in the diamond-mining industry in colonial Ghana (Gold Coast). Relying on archival, oral, and visual sources, this article highlights women’s involvement in Ghana’s diamond industry in different capacities—as discoverers, washers, licensed prospectors, and dealers. Ultimately, I argue that the dominance men have enjoyed in studies about diamond mining in Ghana (and Africa generally) reproduces the colonial archive but can be overcome through creative and innovative research.
On July 19, 2024, the International Court of Justice (ICJ) rendered an advisory opinion on Legal Consequences Arising from the Policies and Practices of Israel in the Occupied Palestinian Territory, Including East Jerusalem. By votes of 11–4, the Court found that Israel's continued presence in the Occupied Palestinian Territory (OPT) was unlawful and needed to be ended as rapidly as possible. By a 14–1 majority, the Court also found that Israel was obligated to cease all new settlement activities, evacuate existing settlers from the OPT, and make reparation. The ICJ further opined by votes of 12–3 that all states and international organizations were obliged not to recognize as legal the situation arising from Israel's unlawful presence in the OPT, that all states must refrain from giving aid or assistance to the maintenance of that situation, and that the United Nations “should consider the precise modalities” required to bring Israel's unlawful presence in the OPT to an end.
Which additional epistemic skills or attributes must a competent journalist possess in order to produce competent science journalism? I aim to answer this question by bringing together insights from journalism, science communication, and epistemology. In Section 2, I outline the Epistemic Challenge for Science Journalism. In Section 3, I present the dominant answer in the literature, the Knowledge-Based Solution, and argue against it. In Section 4, I propose an alternative, the Confirmation-Based Solution. In Section 5, I argue that this solution can address recent concerns regarding journalistic objectivity. Section 6 discusses my proposal in the context of epistemological debates about norms of assertion. Section 7 concludes.
We describe a geometric, stable pair compactification of the moduli space of Enriques surfaces with a numerical polarization of degree $2$, and identify it with a semitoroidal compactification of the period space.