A wolf in sheep"s clothing: carnivory in dominant sea urchins in the Mediterranean

Arbacia lixula and Paracentrotus lividus are the dominant sea urchins in the Mediterranean sublittoral, where they are key structuring species due to their grazing activity. It has been commonly accepted that competition between both species is minimized by specializing in different algal foods. A. lixula is considered to feed mainly on encrusting coralline algae, while P. lividus prefers fleshy macroalgae. We used stable isotope analysis to test if these species occupy different trophic positions at 3 locations in the western Mediterranean and one in Macaronesia. Our results show unambiguously that A. lixula always occupies a higher trophic level than P. lividus, with a δ15N comparable in some locations to strict carnivores such as Actinia schmidti or Marthasterias glacialis. A temporal monitoring at one locality showed that this signature of a higher trophic level is consistent throughout the year. These results are incompatible with the current belief of an herbivorous diet for A. lixula and suggest that it must be considered an omnivore tending to carnivory in Mediterranean ecosystems, feeding at least partially on sessile animals such as Cirripedia, Hydrozoa or Bryozoa. A parallel analysis of gut contents showed a predominance of vegetal items in both species, although A. lixula consistently had a higher abundance of animal components than P. lividus. Our results challenge the validity of using gut content observations alone for characterizing the trophic behaviour of omnivorous marine invertebrates that feed on a variety of food sources with different digestibility.

Genetic consequences of population expansions and contractions in the common hippopotamus (Hippopotamus amphibius) since the Late Pleistocene.

Over the past two decades, an increasing amount of phylogeographic work has substantially improved our understanding of African biogeography, in particular the role played by Pleistocene pluvial-drought cycles on terrestrial vertebrates. However, still little is known on the evolutionary history of semi-aquatic animals, which faced tremendous challenges imposed by unpredictable availability of water resources. In this study, we investigate the Late Pleistocene history of the common hippopotamus (Hippopotamus amphibius), using mitochondrial and nuclear DNA sequence variation and range-wide sampling. We documented a global demographic and spatial expansion approximately 0.1-0.3 Myr ago, most likely associated with an episode of massive drainage overflow. These events presumably enabled a historical continent-wide gene flow among hippopotamus populations, and hence, no clear continental-scale genetic structuring remains. Nevertheless, present-day hippopotamus populations are genetically disconnected, probably as a result of the mid-Holocene aridification and contemporary anthropogenic pressures. This unique pattern contrasts with the biogeographic paradigms established for savannah-adapted ungulate mammals and should be further investigated in other water-associated taxa. Our study has important consequences for the conservation of the hippo, an emblematic but threatened species that requires specific protection to curtail its long-term decline.

Wavelet Analysis in Turbulence

The objective of this thesis is to study wavelets and their role in turbulence applications. Under scrutiny in the thesis is the intermittency in turbulence models. Wavelets are used as a mathematical tool to study the intermittent activities that turbulence models produce. The first section generally introduces wavelets and wavelet transforms as a mathematical tool. Moreover, the basic properties of turbulence are discussed and classical methods for modeling turbulent flows are explained. Wavelets are implemented to model the turbulence as well as to analyze turbulent signals. The model studied here is the GOY (Gledzer 1973, Ohkitani & Yamada 1989) shell model of turbulence, which is a popular model for explaining intermittency based on the cascade of kinetic energy. The goal is to introduce better quantification method for intermittency obtained in a shell model. Wavelets are localized in both space (time) and scale, therefore, they are suitable candidates for the study of singular bursts, that interrupt the calm periods of an energy flow through various scales. The study concerns two questions, namely the frequency of the occurrence as well as the intensity of the singular bursts at various Reynolds numbers. The results gave an insight that singularities become more local as Reynolds number increases. The singularities become more local also when the shell number is increased at certain Reynolds number. The study revealed that the singular bursts are more frequent at Re ~ 107 than other cases with lower Re. The intermittency of bursts for the cases with Re ~ 106 and Re ~ 105 was similar, but for the case with Re ~ 104 bursts occured after long waiting time in a different fashion so that it could not be scaled with higher Re.

Les voix des contes : stratégies narratives et projets discursifs des contes de Perrault, Grimm et Andersen

Les contes de Charles Perrault, des frères Jacob et Wilhelm Grimm, et de Hans Christian Andersen sont parmi les plus connus du genre, mais leur rapprochement masque parfois le fait qu'ils n'ont pas été écrits à la même époque, ni dans la même culture, et qu'ils comportent de nombreuses différences, notamment du point de vue thématique. Il y a cependant aussi des textes extrêmement proches dans leurs recueils : « La belle au bois dormant » raconte comme « Dornröschen » (« Rose d'épine ») l'histoire d'une princesse condamnée à dormir cent ans, puis réveillée par un prince ; « Die sechs Schwäne » (« Les six cygnes ») et « De vilde Svaner » (« Les cygnes sauvages ») relatent tous les deux l'histoire d'une princesse à la recherche de ses frères transformés en cygnes par leur belle-mère. Ces cas-là aident à appréhender les différences essentielles entre les textes, mais aussi à mieux comprendre pourquoi, en dépit des différences, ils sont reconnus comme des parangons du genre. Avec une double approche linguistique et comparatiste, cette thèse s'attache à montrer que les auteurs construisent des manières de raconter particulières. Cela concerne par exemple la place du narrateur dans le récit, la logique selon laquelle s'enchaînent les événements, ou encore l'utilisation du discours représenté. Loin de constituer de simples préférences stylistiques, ces stratégies narratives doivent être mises en relation avec un « projet discursif » : en décidant de publier un recueil de contes, comment les auteurs envisagent-ils le genre, et comment se situent-ils dans le contexte littéraire et culturel de l'époque ? Bien que Perrault, les Grimm et Andersen développent chacun un projet différent, ils exploitent tous trois un mode d'énonciation particulier, à la façon d'un discours rapporté : le conte apparaît comme un enchevêtrement de voix où un conteur relate une histoire déjà racontée auparavant, comme s'il rapportait la voix d'un autre conteur, s'inscrivant ainsi dans une tradition où l'on parle toujours à la suite de quelqu'un. L'analyse des différences entre Perrault, les Grimm et Andersen permet ainsi de construire une poétique du genre : écrire un conte, c'est convoquer une tradition populaire et, d'un point de vue énonciatif, c'est inscrire sa voix dans le concert des voix généré par le conte.

The odd couple: contrasting phylogeographic patterns in two sympatric sibling species of woodlouse-­‐hunter spiders in the Canary Islands

Comparative phylogeography seeks for commonalities in the spatial demographic history of sympatric organisms to characterize the mechanisms that shaped such patterns. The unveiling of incongruent phylogeographic patterns in co-occurring species, on the other hand, may hint to overlooked differences in their life histories or microhabitat preferences. The woodlouse-hunter spiders of the genus Dysdera have undergone a major diversi cation on the Canary Islands. The species pair Dysdera alegranzaensis and Dysdera nesiotes are endemic to the island of Lanzarote and nearby islets, where they co-occur at most of their known localities. The two species stand in sharp contrast to other sympatric endemic Dysdera in showing no evidence of somatic (non-genitalic) differentiation. Phylogenetic and population genetic analyses of mitochondrial cox1 sequences from an exhaustive sample of D. alegranzaensis and D. nesiotes specimens, and additional mitochondrial (16S, L1, nad1) and nuclear genes (28S, H3) were analysed to reveal their phylogeographic patterns and clarify their phylogenetic relationships. Relaxed molecular clock models using ve calibration points were further used to estimate divergence times between species and populations. Striking differences in phylogeography and population structure between the two species were observed. Dysdera nesiotes displayed a metapopulation-like structure, while D. alegranzaensis was characterized by a weaker geographical structure but greater genetic divergences among its main haplotype lineages, suggesting more complex population dynamics. Our study con rms that co-distributed sibling species may exhibit contrasting phylogeographic patterns in the absence of somatic differentiation. Further ecological studies, however, will be necessary to clarify whether the contrasting phylogeographies may hint at an overlooked niche partitioning between the two species. In addition, further comparisons with available phylogeographic data of other eastern Canarian Dysdera endemics con rm the key role of lava ows in structuring local populations in oceanic islands and identify localities that acted as refugia during volcanic eruptions

The Articulation of Different Life Domains among Female Senior Managers and Their Subjective Well-Being : Focusing on Meaning Constructions in Everyday Life

Work-life issues have become a major concern across Western societies with the objective to promote women's careers and well-being. However, despite growing attempts to increase the number of women in senior management positions in European countries, such as Switzerland, they remain highly underrepresented. Inspired from the cultural approach in psychology, this article focuses on these women's concrete everyday life to understand how they articulate different life domains and how this influences their subjective well-being. A narrative approach based on reflexivity is adopted to analyze women's activity. Results show meaning intertwinements between life priorities that are often conflicting. Two psychological functions are identified: the feeling of control and the letting go of control. Each of these contributes to women's subjective well-being through the use of diversified supports, but their structuring roles appear only in relation to one another. Results are discussed in the light of existing literature and of their implications.

Osakeyhtiön nimellisarvoton pääomajärjestelmä

Tutkimuksen tavoitteena on tarkastella, millainen pääomajärjestelmä vastaisi parhaiten markkinoiden tämän hetken vaatimuksiin yritysten välisessä kilpailussa. Tutkimuksessa selvitetään, millaisen sääntelyn puitteissa nykyinen osakeyhtiömuoto ilmenee ja miten osakeyhtiölaillinen sääntely ja osakeyhtiö toimijana esiintyvät tutkimuksellisesti. Lisäksi tarkastellaan, mitkä tekijät ovat osaltaan vaikuttaneet siihen, että yritysten tulisi uudistaa pääomajärjestelmäänsä, jotta ne voisivat järjestää toimintansa mahdollisimman tehokkaasti. Tämän tutkielman luonne on puhtaasti teoreettinen. Tutkimus on suoritettu teoreettisesta näkökulmasta pohtien osakeyhtiöiden toiminnan sääntelyä ja millainen pääomajärjestelmä vastaisi nykyisiin liiketoiminnan vaatimuksiin parhaiten. Teorian avulla pyritään lisäämään ymmärtämystä, miksi tarvitaan uutta pääomajärjestelmää ja mitkä tekijät ovat muuttuneet niin, että nykyinen osakeyhtiölain sääntely ei ole enää tehokasta. Lopputuloksena voidaan todeta, että nimellisarvoton pääomajärjestelmä haastaa vahvasti perinteisen pääomarakenteen, sillä sen voisi katsoa vastaavan parhaiten kansainvälistymisen ja rahoitusmarkkinoiden tuomiin tämän hetken vaatimuksiin. Nimellisarvoton pääomajärjestelmä muuttaa osakeyhtiön merkityksellisesti vapaan ja sidotun oman pääoman erien suhdetta tuoden uusia mahdollisuuksia varainhankintaan ja rakenneratkaisuihin.

Structuration du raconter et évaluation de la racontabilité dans l'entretien médiatique

In this study, we assume that the organisation of storytelling activity is sensitive to emerging norms and, specifically, to what is worth telling from a participant's perspective. We associate the methods of conversation analysis with a labovian approach to oral narratives and examine how storytelling is collaboratively and sequentially built during a radio interview parody. After discussing the relevance of parodic data to understand how media practitioners see their own practices (here: telling a story during a media interview), we provide a detailed analysis of a deviant case by considering the relations between structuring the telling and evaluating the tellability. The analysis leads to show what kinds of interactional resources are used to accomplish the activity: for instance, concurrent topic formulations, shared configurations of grammatical constructions, adjacency pairs. The study also points out how competing agendas can configure the activity in dissimilar ways. Eventually, it underlines the issues of being the interviewee and the storyteller at the same time.

Myyttinen nainen johtajana – diskurssianalyysi ”naisjohtajan” kuvan rakentumisesta mediatekstissä

Tutkielman tavoitteena on selvittää, minkälaisista näkökulmista naisesta johtajana kirjoitetaan ja löytyykö mediateksteistä viittauksia myytteihin, arkkityyppeihin tai stereotypioihin. Tutkimusmenetelmänä käytetään diskurssianalyysiä, jonka avulla valittuja tekstejä tutkitaan. Tässä tutkimuksessa media on rajattu käsittämään sanoma- ja aikakauslehdet. Media muokkaa, mallintaa ja uusintaa lukijan käsityksiä naisesta johtajana. Mediatekstissä johtajuus määrittyy miehisen maailmankuvan kautta. Roolijako miehen ja naisen välillä on kirjoituksissa selvä. Naiseen johtajana liitetään sukupuoli, perhe ja yksityiselämä, mies mielletään kirjoituksissa pelkästään johtajaksi. Perheen merkitys naisen johtajakuvassa on hyvin voimakas. Asenteiden ja uskomusten muutostarpeet ovat olemassa, mutta muutokset tapahtuvat hyvin hitaasti. Media ylläpitää ja uusintaa vanhoja arvoja ja asenteita. Myytit, arkkityypit ja stereotypiat vaikuttavat alitajuisesti sosiaalisen todellisuuden rakentumiseen. Ne säilyvät ja vaikuttavat kansantaruissa, mytologioissa ja uskomuksissa, kuten myös mediatekstissä. Medialla voidaan katsoa olevan merkitystä ”naisjohtajan” kuvan rakentumiseen.

Estimación de funciones no lineales en mezclas post-no lineales

This paper proposes a new method for blindly inverting a nonlinear mapping which transforms a sum of random variables. This is the case of post-nonlinear (PNL) source separation mixtures. The importance of the method is based on the fact that it permits to decouple the estimation of the nonlinear part from the estimation of the linear one. Only the nonlinear part is inverted, without considering on the linear part. Hence the initial problem is transformed into a linear one that can then be solved with any convenient linear algorithm. The method is compared with other existing algorithms for blindly approximating nonlinear mappings. Experiments show that the proposed algorithm outperforms the results obtained with other algorithms and give a reasonably good linearized data

Quantification of environment-driven changes in epiphytic macroinvertebrate communities associated to Phragmites australis

The epiphytic macroinvertebrate communities associated with the Common Reed, Phragmites australis (Cav.) Trin. ex Steudel, were examined seasonally from summer 2004 to spring 2005 in eleven coastal lagoons of the Llobregat Delta (NE Spain) following the method proposed by Kornijów & Kairesalo (1994). The aims of the study were to: 1) characterise and quantify changes in epiphytic macroinvertebrate communities along environmental gradients; 2) assess the contribution of elements of the epiphytic compartment to structuring the community; 3) define the optima and tolerances of selected epiphytic macroinvertebrate taxa for the most relevant ecological factors responsible for assemblage composition; and 4) identify possible epiphytic species assemblages that would allow a lagoon"s typology to be established, as well as their representative indicator species. Communities showed statistically significant seasonal variation, with two faunal peaks: one in summer, with high chironomid densities, and the other in winter, with high naidid densities. These peaks showed a clear response to the influence of environmental factors. Salinity explained the highest percentage of total variance (36%), while trophic variables (nutrients, phytoplanktonic chlorophyll-a, and total organic carbon) and epiphyton biomass (19.2 and 4% of total variance explained, respectively) were secondary. Three different epiphytic macroinvertebrate species assemblages could be defined. These assemblages were directly linked to conductivity conditions, which determined the rate of survival of certain taxa, and to the existence of a direct connection with the sea, which permitted the establishment of 'brackish-water' species. In spite of the existence of these species assemblages, the species composition and biomass of epiphytic macroinvertebrates and epiphyton differed substantially between lagoons; both elements were subject to changes in the environment, which finally determined the site-to-site variation in the density and composition of the macroinvertebrate population

Naiskiintiöt ja työelämän tasa-arvo – diskurssianalyysi sukupuolikiintiöiden rakentumisesta eräiden suomalaisten lehtien teksteissä

Tutkielman tavoitteena on selvittää, miten ”sukupuolikiintiöt yritysten hallituksissa” rakentuvat suomalaisessa mediassa ja sitä kautta; nähdäänkö sukupuolikiintiöt toimivana keinona saavuttaa työelämän tasa-arvo. Tutkielmassa luodaan silmäys sukupuolirooleihin sekä niitä uusintaviin ja ylläpitäviin rakenteisiin yhteiskunnassa. Edelleen tavoitteena on selvittää, murtavatko naiskiintiöt liike-elämässä ja politiikassa vallitsevia johtajuuden sukupuolirooleja. Tutkielmassa käsitellään tasa-arvoa yhteiskunnallisessa, johtajuustutkimuksellisessa ja feministisessä valossa. Sukupuolikiintiöistä kirjoitettaessa voidaan havaita erilaisia suhtautumistapoja niiden vaikutuksesta tasa-arvon toteutumiseen. Tutkielmassa esimerkkeinä käytettyjä lehtitekstejä leimaavat vastakkainasettelut, voimakkaat tunteet ja jakautuminen eri leireihin. Tutkimusmenetelmänä on käytetty kriittistä, valtaorientoitunutta diskurssianalyysiä, joka on antoisa viitekehys mediamaailman käytäntöjen tutkimiseen kontekstissaan. Media on tässä tutkimuksessa rajattu käsittämään tiettyjä suomalaisia sanoma-, aikakausi- ja iltapäivälehtiä. Tutkimuksen pääongelmaksi nousevat tavat, joilla sukupuolikiintiöistä mediassa kirjoitetaan sekä asenteet, joita ne lukijoille välittävät. Tämän tutkimuksen keskeisinä tuloksina voidaan esittää yleisimmät suhtautumistavat sukupuolikiintiötä kohtaan mediassa, sekä kolme diskurssia, jotka useimmiten kiintiökeskusteluissa esiintyvät. Pätevyys- diskurssi painottaa yksilön pätevyyttä ensisijaisena valintakriteerinä hallitusjäseniä valittaessa. Uhka- diskurssi esittää sukupuolikiintiöt uhkavaatimuksena, johon tullaan turvautumaan kulttuuristen muutosten hitauden vuoksi. (Epä)tasa-arvo- diskurssi näkee sukupuolikiintiöt tasa-arvoa edistävänä keinona, mutta toisaalta kokee naiskiintiöt epätasa-arvoisina ja miehiä sortavina.

Studying the recent situation of information and communication technology industry

Globaalinen liiketoimintaympäristö on muutoksessa. Uudet teknologiat muuttavat toimintaympäristöä ja talouden säännöt muuttuvat nopeasti. Uusia liiketoimintamalleja tarvitaan. Tutkimuksen tavoitteena oli analysoida tieto- ja viestintäteollisuuden (ICT-teollisuus) nykytilannetta strategisesta ja kilpailuanalyyttisestä näkökulmasta, sekä luoda kuva ICT-teollisuudesta ja sen suurista pelureista Euroopassa ja USA:ssa. Tutkimus analysoi viittä suurta ICT-alan yritystä. Tutkimus oli luonteeltaan sekä kvalitatiivinen että kvantitatiivinen. Yrityksiä analysoitiin käyttäen numeerista ja laadullista materiaalia. Tutkimus perustui kirjallisuuteen, artikkeleihin, tutkimusraportteihin, yritysten internet-kotisivuihin ja vuosikertomuksiin. Tutkimuksen tuloksena voitiin löytää sekä yhtäläisyyksiä että eroavaisuuksia yritysten liiketoimintamallien ja taloudellisen menestymisen väliltä.

Finding an apprenticeship : hidden curriculum and social consequences

In Switzerland, the majority of students are oriented towards professional training after compulsory schooling. At this stage, one of the biggest challenges for them is to find an apprenticeship position. Matching supply and demand is a complex process that not only excludes some students from having direct access to professional training but also forces them to make early choices regarding their future sector of employment. So, how does one find an apprenticeship? And what do the students' descriptions of their search for apprenticeships reveal about the institutional determinants of social inequalities at play in the system? Based on 29 interviews conducted in 2014 with 23 apprentices and 6 recruiters in the Canton of Vaud, this article interrogates how the dimensions of educational and social trajectories combine to affect access to apprenticeships and are accentuated by recruiters using a "hidden curriculum" during the recruitment process. A hidden curriculum consists of knowledge and skills not taught by the educational institution but which appear decisive in obtaining an apprenticeship. By analysing the contrasting experiences of students in their search for an apprenticeship, we identify four types of trajectories that explain different types of school-to-apprenticeship transitions. We show how these determinants are reinforced by the "hidden curriculum" of recruitment based on the soft skills of feeling, autonomy, anticipation and reflexivity that are assessed in the context of recruitment interactions. The discussion section debates how the criteria that appear to be used to identify the "right apprentice" tend to (re)produce inequalities between students. This not only depends on their academic results but also on their social and cultural skills, their ability to anticipate their choices and, more widely, their ability to be a subject in their recruitment search. "The Subject is neither the individual, nor the self, but the work through which an individual transforms into an actor, meaning an agent able to transform his/her situation instead of reproducing it." (Touraine, 1992, p.476).

Unidirectional quantum walks: Evolution and exit times

In this paper we focus our attention on a particle that follows a unidirectional quantum walk, an alternative version of the currently widespread discrete-time quantum walk on a line. Here the walker at each time step can either remain in place or move in a fixed direction, e.g., rightward or upward. While both formulations are essentially equivalent, the present approach leads us to consider discrete Fourier transforms, which eventually results in obtaining explicit expressions for the wave functions in terms of finite sums and allows the use of efficient algorithms based on the fast Fourier transform. The wave functions here obtained govern the probability of finding the particle at any given location but determine as well the exit-time probability of the walker from a fixed interval, which is also analyzed.