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Otolith morphological and microchemical analyses are relatively new scientific research methods used in fish stock evaluation and management. However, in Tunisia, only morphological methods have been used. The objective of this study was the Sarpa salpa stock discrimination of Djerba and Kerkennah by the otoliths morphological and microchemical analysis, while carrying out a fluctuating asymmetry analysis and a stock comparison of males and females for each population. The results revealed significant differences between the Djerba and Kerkennah populations, significant differences between the stocks of males and females in each population, and a highly significant fluctuating asymmetry for both populations. The results of the otolith morphological analysis were similar to those of the microchemical analysis. This result proves that both morphological and microchemical analyses are powerful tools for fish stock discrimination.
The socioeconomic role of guanxi networks among individuals has been widely recorded, yet macro-level analysis has been sparse in empirical research. This research fills that gap by presenting the first nationally representative evidence illustrating the connection between regional guanxi culture and population mobility among cities in China, with a particular focus on instrumental guanxi culture. To quantify guanxi culture, we employ online search indices related to gift giving, a measure which is challenging to capture through traditional survey data. Applying matched prefecture-level data spanning from 2011 to 2019, the panel model reveals a strong negative correlation between a city's instrumental guanxi culture and inbound migration, while sentimental guanxi culture exhibits a positive correlation with inbound mobility. This research not only adds to the existing theories by exploring the macro-level effects of both instrumental and sentimental guanxi practices but also introduces an innovative method for quantifying guanxi culture through big data analysis.
We present a detailed analysis of random motions moving in higher spaces with a natural number of velocities. In the case of the so-called minimal random dynamics, under some broad assumptions, we give the joint distribution of the position of the motion (for both the inner part and the boundary of the support) and the number of displacements performed with each velocity. Explicit results for cyclic and complete motions are derived. We establish useful relationships between motions moving in different spaces, and we derive the form of the distribution of the movements in arbitrary dimension. Finally, we investigate further properties for stochastic motions governed by non-homogeneous Poisson processes.
A central goal in the field of developmental psychopathology is to evaluate the complex, dynamic transactions occurring among biological, psychological, and broader social-cultural contexts that predict adaptive and maladaptive outcomes across ontogeny. Here, I briefly review research on the effects of a history of childhood maltreatment on parental, child, and dyadic functioning, along with more recent studies on the intergenerational transmission of trauma. Because the experience and sequelae of child maltreatment and the intergenerational transmission of trauma are embedded in complex biopsychosocial contexts, this research is best conceptualized in a developmental psychopathology framework. Moreover, there is a pressing need for investigators in this area of study to adopt dynamic, multi-level perspectives as well as using developmentally guided, sophisticated research methods. Other directions for research in this field are suggested, including the implementation of collaborative interdisciplinary team science approaches, as well as community-based participatory research, to increase representation, inclusion, and equity of community stakeholders. A greater focus on cultural and global perspectives is also recommended.
Relations between diplomats and civil society are central to diplomatic work. However, scholarship on diplomacy has not paid sufficient attention to how diplomats interact with civil society actors abroad. This article theorises and empirically examines diplomatic engagements with civil society organisations (CSOs) in host states. The article introduces a new concept – maternalism – into the analytical toolbox of diplomacy studies. While the Bourdieu-inspired ‘practice turn’ has entailed a recalibration of the study of diplomacy towards the everyday work of diplomats, I claim that we need notions that will help us understand these everyday practices in the context of structural power inequalities. In this endeavour, instead of turning to the established notion of paternalism, I follow feminist thinking regarding motherhood and the ethics of care. Maternalism is proposed as a complementary heuristic to paternalism that is helpful in capturing different modes of engagement between unequal actors in international politics and is not marked by financial dependency or military power. Maternalism and paternalism rely on distinct practices of care and control. To empirically illustrate the utility of the notion of maternalism, I analyse diplomats representing seven liberal states in the illiberal states of Poland and Hungary.
This article focuses on the role of servants in María Lugones’ “Playfulness, ‘World’-Travelling, and Loving Perception.” I show that Lugones uses and erases the work of servants in developing her understanding of world-traveling. This theoretical marginalization and instrumentalization challenges her claim to capture concrete, lived experience. This article argues that Lugones’ theory is “pseudo-concrete”: it capitulates into the very abstractions it seeks to overcome. Focusing on the role of servants reveals the class character of world-traveling and, in turn, its inability to grasp class relations. This article, thus, invites decolonial feminists to reconsider the advantages of class analysis for understanding not only capitalist domination but also perception, identification, and love.
This paper responds to two trends in debates about Plato's view of women in the Republic. First, many scholars argue or assume that Plato seeks to minimize the influence of femininity in the ideal city, and to make guardian women themselves as “masculine” as possible. Second, scholars who address the relationship between Plato's views of women and his psychological theory tend to focus on the reasoning and appetitive parts of the tripartite soul. In response to the first point, we argue that the idea that Plato seeks to masculinize/de-feminize the city oversimplifies his treatment of Greek gender norms. Although he does want to eliminate some traditionally feminine qualities from the city, he also seeks to eliminate many masculine qualities as well. Moreover, while he tries to make guardian women more like men in some respects, he simultaneously aims to make guardian men more like Greek women in important ways. Regarding the second point, we argue that this project of reimagining gender norms is illuminated by Plato's psychology, but instead of emphasizing reason and appetite, we show how his views are connected to his account of the third, “spirited” part of the soul, thumos, and its dual hard/soft or aggressive/gentle nature.
On December 19, 2023, the U.S. Department of State announced the geographic coordinates defining the outer limits of the U.S. continental shelf in areas beyond 200 nautical miles from the coast. For convenience, the United States—and also this Essay—refers to the portion of a country's continental shelf that is beyond 200 nautical miles from the coast as the “extended continental shelf,” or ECS. The announcement states that the United States has ECS in seven different regions which collectively amounts to approximately a million square kilometers (about 380,000 square miles).
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.