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The Black Sea is an enclosed sea surrounded by six coastal countries, of which Bulgaria and Romania are EU Member States. The Convention for the Protection of the Black Sea Against Pollution was ratified in 1994 by all coastal countries. This Convention is the only European regional sea convention to which the EU is not a Party. While Romania and Bulgaria are in favor of EU accession to the Convention, Turkey, Russia and Ukraine thus far have blocked accession. In this paper, we develop a negotiation model with endogenous enforcement and exogenous fraud to analyze the different positions of groups of coastal countries relative to EU accession to the Convention. Our model contributes to defining a proposal that the EU could make to the opposing states such that they accept the EU as a Party to the Convention. In that context we investigate also whether Romania and Bulgaria might be better off delegating their decision power to the EU, rather than retaining their individual voting rights.
Until a decade ago, it was unusual for officials in the Islamic Republic to use the word aqaliat (minority) to refer to ethno-linguistic minorities or Muslim sect minorities. Efforts to cast Sunni Muslims as a minority, or Azeri speakers, were treated with hostility, as the state, following a specific proclamation on ethnicity and sectarianism by Ayatollah Khomeini, viewed these concepts as divisive to the ummah and ultimately a threat to national security. Aqaliat was instead reserved for non-Muslims, specifically those recognized as minorities in the constitution: Assyrian, Chaldean and Armenian Christians, and Zoroastrian and Jewish Iranians. It is therefore worthwhile to examine how one such minority community, Iranian Armenians, has reacted to these changes.
Mature leaves of tree seedlings were exposed to high light in four experimental gaps in the Jamaican upper montane rainforest (UMRF). Two of the six species studied were light-demanders: Alchornea latifolia and Clethra occidentalis. Two were gap-favoured: Pittosporum undulatum (an invasive) and Palicourea alpina (a subcanopy shrub). One was intermediate: Hedyosmum arborescens, and one was shade-tolerant: Guarea glabra. After five months, the following significant changes occurred in shade leaves that were exposed to gaps (‘shade-to-gap’ leaves; values as % of those in the pre-gap shade): maximum rate of photosynthesis + 40% (Alchornea), +35% (Clethra), −34% (Pittosporum), +72% (Palicourea); dark respiration +120% (Alchornea), +140% (Clethra), +60% (Pittosporum), +233% (Palicourea), +175% (Hedyosmum), +100% (Guarea); leaf thickness +18% (Alchornea), +18% (Clethra), +14% (Palicourea); leaf mass per unit area +18% (Alchornea), +15% (Pittosporum). Leaves produced in the gaps were (as a percentage of total live leaf number) 74% (Alchornea), 71% (Clethra), 50% (Pittosporum), 71% (Palicourea), 62% (Hedyosmum) and 50% (Guarea). Photosynthetic rates of leaves produced in the gaps were 53–120% higher than ‘shade-to-gap’ leaves. Overall, shade leaves on the three native, more light-demanding species (Alchornea, Clethra and Palicourea) showed photosynthetic acclimation, while the more shade-tolerant species (Hedyosmum and Guarea and Pittosporum undulatum) showed little acclimation in shade-to-gap leaves.
Thriving at work is closely related to the way employees are embedded in their social contexts, such as the structure of their communication relations with coworkers. In previous research, communication relations have been found to negatively relate to thriving at work. However, social network theory suggests that communication relations are beneficial in obtaining resources in the workplace, which might increase thriving at work. To reconcile the seemingly conflicting mechanisms, we draw on social network theory to unpack the mechanisms underlying communication relations by considering the instrumental and expressive roles. Using a structural equation model, we investigate the indirect effects of communication networks on thriving at work via advice-seeking networks (instrumental) and friendship networks (expressive). Our findings indicate communication relations are negatively related to thriving at work via advice-seeking relations, but are positively related to thriving at work via friendship relations.
The viscoelasticity of a dilute bubble suspension is theoretically derived from the constitutive equation originally for a dilute emulsion proposed by Frankel & Acrivos (J. Fluid Mech., vol. 44, issue 1, 1970, pp. 65–78). Non-dimensionalization of the original tensor equation indicates that the viscoelasticity is systematized for a given void fraction by the capillary number $Ca$ and dynamic capillary number $Cd$, representing the bubble deformability and unsteadiness of bubble deformation. Comprehensive evaluation of the viscoelasticity according to the volume fraction, $Ca$ and $Cd$ reveals that whether the viscosity increases or decreases depends on whether $Ca$ or $Cd$ exceeds a common critical value. In addition, it is indicated that the bubble suspension has the most prominent viscoelasticity when the time scale of the shear deformation is the same as the relaxation time of the suspended bubble and when the bubbles keep a spherical shape, that is, $Ca \ll 1$ and $Cd = 1$. The applicability of this theory in flow prediction was examined in a Taylor–Couette system, and experimentally good agreement was confirmed.
Epistemic exhaustion is cognitive fatigue generated by efforts to determine, retain, or communicate what one believes under conditions that make doing so especially taxing. I argue that the creation and maintenance of epistemic exhaustion is a tool that the socially and politically powerful can and do use in order to retain power. I consider a variety of conversational tactics and three circumstances—partisan polarization, epistemic chaos, and epistemic oppression—that can leave people prone to epistemic exhaustion. I survey several common responses to epistemic exhaustion and offer some suggestions for how we ought to respond to epistemically exhausting circumstances.
Schistosomiasis is a serious health issue in tropical regions, and natural compounds have gained popularity in medical science. This study investigated the potential effects of pumpkin seed oil (PSO) on Biomphalaria [B.] alexandrina snails (Ehrenberg, 1831), Schistosoma [S.] mansoni (Sambon, 1907) miracidium, and cercariae. The chemical composition of PSO was determined using gas chromatography/mass spectrometry. A bioassay was performed to evaluate the effects of PSO on snails, miracidia, and cercariae. The results showed no significant mortality of B. alexandrina snails after exposure to PSO, but it caused morphological changes in their hemocytes at 1.0 mg/ml for 24 hours. PSO exhibited larvicidal activity against miracidia after 2 hours of exposure at a LC50 of 618.4 ppm. A significant increase in the mortality rate of miracidia was observed in a dose- and time-dependent manner, reaching a 100% death rate after 10 minutes at LC90 and 15 minutes at LC50 concentration. PSO also showed effective cercaricidal activity after 2 hours of exposure at a LC50 of 290.5 ppm. Histological examination revealed multiple pathological changes in the digestive and hermaphrodite glands. The PSO had genotoxic effects on snails, which exhibited a significant increase [p≤0.05] in comet parameters compared to the control. The findings suggest that PSO has potential as a molluscicide, miracidicide, and cercaricide, making it a possible alternative to traditional molluscicides in controlling schistosomiasis.
In recent decades, Canada and other democracies have experienced a significant rise in migrant settlement. This has sparked much interest among scholars and policy makers in the forces that encourage or impede the political incorporation of newcomers. In this research note, we consider a factor that has received relatively little scrutiny, the impact of immigrants’ attention to native-country politics on willingness to participate in residential-country elections and affiliate with a political party in that country. We examine this through an original survey of Americans in Canada conducted during the 2020 US election cycle. A randomized experiment demonstrates that directing the attention of American emigrants to US campaigns can lower interest in Canadian elections and weaken attachments to a Canadian political party, particularly for those who are less integrated into Canadian society. These findings point to a potential tension between political engagement as an emigrant versus as an immigrant.
Grapevine fanleaf virus (GFLV) is one of the most severe virus diseases of grapevines, causing fanleaf degeneration that is transmitted by Xiphinema index. This paper aims to isolate Xiphinema species from Tunisian vineyard soil samples and assess their ability to acquire and transmit GFLV under natural and controlled conditions. Based on morphological and morphometric analyses, Tunisian dagger nematodes were identified as X. index and Xiphinema italiae. These results were confirmed with molecular identification tools using species-specific polymerase chain reaction primers. The total RNA of GFLV was extracted from specimens of Xiphinema and amplified based on real-time polymerase chain reaction using virus-specific primers. Our results showed that X. index could acquire and transmit the viral particles of GFLV. This nepovirus was not detected in X. italiae, under natural conditions; however, under controlled conditions, this nematode was able to successfully acquire and transmit the viral particles of GFLV.
The column collapse experiment is a simplified version of natural and industrial granular flows. In this set-up, a column built with grains collapses and spreads over a horizontal plane. Granular flows are often studied with a monodisperse distribution; however, this is not the case in natural granular flows where a variety of grain sizes, known as polydispersity, is a common feature. In this work, we study the effect of polydispersity, and of the inherent changes that polydispersity causes in the initial packing fraction, in dry and immersed columns. We show that dry columns are not significantly affected by polydispersity, reaching similar distances at similar times. In contrast, immersed columns are strongly affected by the polydispersity and packing fraction, and the collapse sequence is linked to changes of the basal pore fluid pressure $P$. At the collapse initiation, negative changes of $P$ beneath the column produce a temporary increase of the column strength. The negative change of $P$ lasts longer in polydisperse columns than in monodisperse columns, delaying the collapse sequence. Conversely, during the column spreading, positive changes of $P$ lead to a decrease of the shear strength. For polydisperse collapses, the excess of $P$ lasts longer, allowing the material to reach farther distances, compared with the collapses of monodisperse materials. Finally, we show that a mobility model that scales the final runout with the collapse kinetic energy remains true for different polydispersity levels in a three-dimensional configuration, capturing the scaling between the micro to macro controlling features.
We study a version of the Craig interpolation theorem formulated in the framework of the theory of institutions. This formulation proved crucial in the development of a number of key results concerning foundations of software specification and formal development. We investigate preservation of interpolation properties under institution extensions by new models and sentences. We point out that some interpolation properties remain stable under such extensions, even if quite arbitrary new models and sentences are permitted. We give complete characterisations of such situations for institution extensions by new models, by new sentences, as well as by new models and sentences, respectively.
In this article, I argue that God is authoritative over us because he is our divine, causal parent. As our causal parent, God has duties to relate to us, but he can only fulfil those duties if he has the practical authority to give us commands aimed at our sanctification. From ought-implies-can reasoning, I conclude that God has that authority. After I make this argument, I show how the view has significant advantages over extant arguments for divine authority and can help solve other significant problems in philosophy of religion.
By using fixed point argument, we give a proof for the existence of singular rotationally symmetric steady and expanding gradient Ricci solitons in higher dimensions with metric $g=\frac {da^2}{h(a^2)}+a^2g_{S^n}$ for some function h where $g_{S^n}$ is the standard metric on the unit sphere $S^n$ in $\mathbb {R}^n$ for any $n\ge 2$. More precisely, for any $\lambda \ge 0$ and $c_0>0$, we prove that there exist infinitely many solutions ${h\in C^2((0,\infty );\mathbb {R}^+)}$ for the equation $2r^2h(r)h_{rr}(r)=(n-1)h(r)(h(r)-1)+rh_r(r)(rh_r(r)-\lambda r-(n-1))$, $h(r)>0$, in $(0,\infty )$ satisfying $\underset {\substack {r\to 0}}{\lim }\,r^{\sqrt {n}-1}h(r)=c_0$ and prove the higher-order asymptotic behavior of the global singular solutions near the origin. We also find conditions for the existence of unique global singular solution of such equation in terms of its asymptotic behavior near the origin.
Biological types, including holotypes and reference genomes, are particular biological entities that represent an entire class of biological entities. This paper presents a feminist analysis of biological typing by asking whether we have reason to criticize the practices of selecting holotypes and reference genomes for being androcentric. I offer three distinct reasons why androcentrism can be objectionable: androcentric practices may inadequately account for traits or experiences of women/females, reinforce male/female dichotomies, or overgeneralize from particulars. I then evaluate whether the practices of selecting holotypes and genomes are objectionably androcentric in these three ways. These typing practices, especially as applied to the case of humans, are objectionably androcentric in some ways but not others. Whether a typing practice problematically ignores the traits or experiences of women depends on whether the typing practice involves non-accidentally taking the traits or experiences of male humans as typical, which, I argue, is true both in the case of holotypes and genomes. Neither holotypes nor genomes reinforce male/female dichotomies, although some features of these practices may appear to do so. Finally, both holotypes and genomes are criticizable for overgeneralizing from particulars, although this criticism does not depend on these practices being androcentric.
Boundary-layer disturbances are analysed on a $5^{\circ }$ half-angle blunted cone in Mach 5, high-enthalpy flow ($h_0 = 9\ {\rm MJ}\ {\rm kg}^{-1}$) with a low wall-to-edge temperature ratio, $T_w/T_e = 0.18$. Schlieren and focused laser differential interferometry (FLDI) are utilized to assess the structures and frequency content associated with disturbances. Wave packets are identified from bursts of modal content on time-resolved spectrograms. Bandpass filtering, proper orthogonal decomposition (POD) and space–time POD are then applied to the schlieren data. Bandpass filtering suggests the presence of wave packet dispersion and elongation indicative of slow-acoustic-wave synchronization. Modal reconstruction techniques indicate the radiation of content outside the boundary layer and distinct orientation changes within disturbances, potentially the first experimental evidence of the supersonic-mode instability in such a flow field. Cross-bicoherence computations are carried out for discrete time segments of data from both schlieren and FLDI data. They demonstrate that the most dominant nonlinear interactions are the fundamental–first-harmonic and the fundamental–low-frequency interactions.
The gas-particle flow with multiple dispersed solid phases is associated with a complicated multiphase flow dynamics. In this paper, a unified algorithm is proposed for the gas-particle multiphase flow. The gas-kinetic scheme (GKS) is used to simulate the gas phase and the multiscale unified gas-kinetic wave–particle (UGKWP) method is developed for the multiple dispersed solid particle phase. For each disperse solid particle phase, the decomposition of deterministic wave and statistic particle in UGKWP is based on the local cell's Knudsen number. The method for solid particle phase can become the Eulerian fluid approach at the small cell's Knudsen number and the Lagrangian particle approach at the large cell's Knudsen number. This becomes an optimized algorithm for simulating dispersed particle phases with a large variation of Knudsen numbers due to different physical properties of the individual particle phase, such as the particle diameter, material density, etc. The GKS-UGKWP method for gas-particle flow unifies the Eulerian–Eulerian and Eulerian–Lagrangian methods. The particle and wave decompositions for the solid particle phase and their coupled evolution in UGKWP come from the consideration to balance the physical accuracy and numerical efficiency. Two cases of a gas–solid fluidization system, i.e. one circulating fluidized bed and one turbulent fluidized bed, are simulated. The typical flow structures of the fluidized particles are captured, and the time-averaged variables of the flow field agree well with the experimental measurements. In addition, the shock particle–bed interaction is studied by the proposed method, which validates the algorithm for the polydisperse gas-particle system in the highly compressible case, where the dynamic evolution process of the particle cloud is investigated.
The mining industry is heavily dependent on energy-intensive processes, such as rock breakage, which leads to significant operational costs. This paper explores microwave-assisted rock breakage as an innovative method to enhance the efficiency of comminution within the mining industry. It introduces a system that employs a Klystron microwave power source with a maximum output of 7.5 MW, using a $\mathrm{TM}_{010}$ single-mode cavity at 3 GHz, to channel energy inside a specially designed rock cavity. The paper emphasizes the importance of designing an efficient microwave cavity for this system, focusing on the cavity’s design and simulation. Through both simulated results (using HFSS software) and experimental observations, the study reveals the promising application of microwave technology in the field of mining. The simulated frequency response of the designed cavity (S11) is −22 dB, it demonstrates significant potential for reducing both energy consumption and associated costs. Additionally, the designed cavity is fabricated from aluminum and filled with polyether ether ketone material. The measured frequency response (S11) of the cavity at 3 GHz is −17 dB.