Generic method for bijections between blossoming trees and planar maps

This article presents a unified bijective scheme between planar maps and blossoming trees, where a blossoming tree is defined as a spanning tree of the map decorated with some dangling half-edges that enable to reconstruct its faces. Our method generalizes a previous construction of Bernardi by loosening its conditions of applications so as to include annular maps, that is maps embedded in the plane with a root face different from the outer face. The bijective construction presented here relies deeply on the theory of \alpha-orientations introduced by Felsner, and in particular on the existence of minimal and accessible orientations. Since most of the families of maps can be characterized by such orientations, our generic bijective method is proved to capture as special cases all previously known bijections involving blossoming trees: for example Eulerian maps, m-Eulerian maps, non separable maps and simple triangulations and quadrangulations of a k-gon. Moreover, it also permits to obtain new bijective constructions for bipolar orientations and d-angulations of girth d of a k-gon. As for applications, each specialization of the construction translates into enumerative by-products, either via a closed formula or via a recursive computational scheme. Besides, for every family of maps described in the paper, the construction can be implemented in linear time. It yields thus an effective way to encode and generate planar maps. In a recent work, Bernardi and Fusy introduced another unified bijective scheme, we adopt here a different strategy which allows us to capture different bijections. These two approaches should be seen as two complementary ways of unifying bijections between planar maps and decorated trees.Comment: 45 pages, comments welcom

A Behavioral Test of the Affinity-Seeking Model: Nonverbal Tactics Among Strangers and Acquaintances.

This research examined the Affinity-Seeking model devised by Bell and Daly (1984). Two components of the model were considered: preinteraction expectancies constraining a social encounter and the competency of the individual as an affinity-seeker. It was hypothesized that strangers would approach a friendly target through the reciprocity strategy and an unfriendly target through the compensatory strategy by increasing behavioral cues of immediacy (e.g., eye-gaze, smiling/laughter, verbalizations, and proximity). It was hypothesized, on the other hand, that acquaintances would not increase their behavioral involvement in view of a friendly expectancy while they would compensate for an unfriendly one. The findings revealed that neither strangers nor acquaintances actively sought affinity with their partners. Rather, they adopted passive affinity-seeking strategies (concede control, conversational rule-keeping) as the means to ensure a pleasant and polite encounter. The behavioral components of affinity-seeking competency were addressed

Non-Metric Cranial Differentiation Between Asian and Native American Populations for Ancestry Assessment

Assessing ancestry from skeletal remains provides important information to aid in personal identification. However, trying to specify ancestry for Native American and Asian populations in the United States is a current challenge in laboratory analyses. Both Native American and Asian populations are still often combined in research for a variety of reasons: small sample sizes, skeletal similarities and less emphasis in contemporary literature. Historically, Carlton Coon, in 1939, and Riesenfield, in 1956, refer to this combination of both Native American and Asian populations as “Mongoloid,” a term which is deemed by many as an offensive and inaccurate categorization of both populations by modern standards. The intent of this research is to analyze non-metric features of Native American and Asian crania to determine which traits, if any, may be used to differentiate between those two populations. Data analysis using frequency tables, chi-square and logistic regression methods show that some traits are statistically significant and are, therefore, linked to one population. By using these traits to help differentiate between Native American and Asian crania, ancestry may be identified more easily in forensic casework

Encouraging ‘Returns’, Obstructing Departures and Constructing Causal Links: The New Creed of Euro-African Migration Management

This paper explores whether the policy level constitutes a new element in what Hernández-León coined as “the migration industry” in 2005. The paper unravels the impact of semantic and legal shifts at different scales over the past two decades on the framing of irregular migration. Several key moments have marked Euro-African relations in the field migration. Through the decoding of political exchanges between African and European actors, this article shows the predominant objectives of migration policies. The first aims to encourage "returns" of migrants from Europe to Africa. The second seeks to dissuade potential African candidates from leaving (implied towards Europe), and the third presupposes that the returns of some migrants will make potential migrants renounce the journey. In order to prevent departures and to justify returns, new causal links appear in speeches. There is here an idea of an archetypal model linking returns and deterrents. This binary justification of a presupposed causality between returns and departures is questionable however because evidence shows that returns will not necessarily have the expected deterrent effect. Nevertheless, the migration and development nexus has gradually come to complement the migration and security nexus. At different scales and through semantic and legal shifts, emigration has been framed as a “problem” then as a “crime” in the dominant policy discourse. Through the design and implementation of departure deterrence programmes, actors from NGOs, international organisations, political institutions and the media are strengthening the controversial notion of "illegal emigration" which, gradually, has become a new resource in the field of migration management.DFI

Understanding college student emotional functioning during COVID-19

The novel coronavirus has resulted in mass infection and death. To prevent spread of the virus, colleges and universities shut down and transitioned to remote learning, which mandated all college students to leave residential housing and relocate to a permanent address. Previous literature suggests college students who experienced housing displacement due to a natural disaster reported heightened distress and poorer overall functioning (Davis, Grills-Taquechel, & Ollendick, 2010). Prior to the COVID-19 outbreak, college student mental health was deemed a public health concern, however, it is expected to worsen following the outbreak (Galea, Merchant, & Lurie, 2020). Researchers suggest peer support and connection buffers against worsened psychological symptoms when students experience disaster (Kuhl & Boyraz, 2017). This study seeks to understand pre-COVID place of residence and campus connectedness as a predictor for emotional functioning two months into the pandemic. A moderated regression analysis was used to evaluate if campus connectedness and emotional functioning varied as a function of place of residence before the outbreak. Findings suggested no significant interaction between pre-COVID place of residence and campus connectedness, however, exploratory analyses revealed that gender and trauma history affect emotional functioning among students. Implications of this research suggest that historical trauma should be considered for students who experience disaster and, perhaps, universities should adopt a trauma-informed approach to welcome students back on campus during the pandemic

Hasard, providence et politique chez Jean Bodin

Egalement publié en ligne en 2007, sur le site des actes du 49e colloques international d'études humanistes, Tours, 3-9 juillet 2006. CESR [Centre d'études supérieures de la Renaissance]. http://umr6576.cesr.univ-tours.fr/Publications/HasardetProvidence/fichiers/pdf/Couzinet.pdf"Dans les Six Livres de la République, Bodin affirme qu'« il n'y a rien de fortuit en ce monde ». Alors que Machiavel et Montaigne accordent une place centrale à la Fortune en politique, Bodin semble vouloir l'en éliminer complètement, car en jouant la providence contre le hasard, il apporte des éléments de réponse à une question qui est aussi la leur : à quelles conditions une communauté politique, quel qu'en soit le régime, peut-elle prolonger sa survie le plus longtemps possible, sachant que, comme tous les êtres naturels, elle est mortelle ? Alors que, pour Montaigne et Machiavel, les grands événements sont le plus sujets à la Fortune et le moins aux volontés humaines, Bodin y voit autant de manifestations sensibles de Dieu dans la nature, pensables en termes de « conjonctions » : tout ce qui arrive résulte de la conjonction de plusieurs causes et, dans le cas des grands événements, le concours des astres, des nombres et des volontés humaines témoigne de l'action d'un Dieu qui a tout créé selon le nombre, le poids et la mesure. C'est dans ce sens qu'il n'y a pas de hasard.

Using Mobile Technology to Increase the Math Achievement and Engagement of Students with Disabilities

The advent of advanced technologies provides new opportunities for delivering instruction to students with disabilities. Many classrooms have access to mobile devices, such as iPads and Kindles, and educators utilize these devices to differentiate instruction and augment teacher-led instruction. This delivery method, known as blended learning, can create an enriched learning environment where students are exposed to individualized lessons that are self-paced and provide multiple modes of presentation. However, there is little empirical investigation into how students interact with digital devices or what components of online learning directly impact student learning and engagement with the content. In order to design authentic learning experiences that support students with disabilities and provide access to the general education curriculum, it is critical that researchers thoroughly examine the design on digital lessons and how students navigate digital environments. The focus of this study was to investigate how students use mobile devices in a classroom setting and how they interact with academic content delivered in a digital format. The math achievement and engagement of students with disabilities was compared in two conditions - teacher-led math instruction (Traditional Math Instruction, TMI) and instruction delivered on a mobile device (Mobile App Instruction, MAI). Additionally, teacher and student perceptions of math knowledge and engagement were collected for both conditions using surveys. The surveys were administered after the intervention was completed. The results of the study indicate neither instructional method was significantly more effective in increasing the math achievement or the engagement of students with disabilities. Survey data revealed the teacher did not feel one condition was more effective at increasing math achievement or engagement. Data from the student surveys indicated that students in the TMI condition felt they learned more and were more engaged than the students in the MAI condition. Observational data indicated there was no significant difference in engagement for students in the TMI group and the MAI group. Data collected from the online learning platform suggested students easily accessed the lessons and completed embedded activities and questions. However, data from the learning videos indicate students accessed the videos but did not watch them through to completion, and did not answer the embedded questions

Biotransformation of halogenated compounds by lyophilized cells of Rhodococcus erythropolis in a continuous solid-gas biofilter

The irreversible hydrolysis of 1-chlorobutane to 1-butanol and HCl by lyophilized cells of Rhodococcus erythropolis NCIMB 13064, using a solid–gas biofilter, is described as a model reaction. 1-Chlorobutane is hydrolyzed by the haloalkane dehalogenase from R. erythropolis. A critical water thermodynamic activity (aw ) of 0.4 is necessary for the enzyme to become active and optimal dehalogenase activity for the lyophilized cells is obtained for a aw of 0.9. A temperature of reaction of 40 ◦ C represents the best compromise between stability and activity. The activation energy of the reaction was determined and found equal to 59.5 kJ/mol. The absence of internal diffusional limitation of substrates in the biofilter was observed. The apparent Michaelis–Menten constants Km and Vmax for the lyophilized cells of R. erythropolis were 0.011 (1-chlorobutane thermodynamic activity, aClBut ) and 3.22 µmoles/min g of cell, respectively. The activity and stability of lyophilized cells were dependent on the quantity of HCl produced. Since possible modifications of local pH by the HCl product, pH control by the addition of volatile Lewis base (triethylamine) in the gaseous phase was employed. Triethylamine plays the role of a volatile buffer that controls local pH and the ionization state of the dehalogenase and prevents inhibition by Cl− . Finally, cells broken by the action of the lysozyme, were more stable than intact cells and more active. An initial reaction rate equal to 4.5 µmoles/min g of cell was observed