Spermiogenesis and ultrastructure of the spermatozoon of Wardula capitellata (Digenea, Mesometridae), an intestinal parasite of the sparid teleost Sarpa salpa in Senegal

The spermiogenesis process in Wardula capitellata begins with the formation of a differentiation zone containing two centrioles associated with striated rootlets and an intercentriolar body. Each centriole develops into a free flagellum orthogonal to a median cytoplasmic process. Later these flagella rotate and become parallel to the median cytoplasmic process, which already exhibits two electron-dense areas and spinelike bodies before its proximodistal fusion with the flagella. The final stage of the spermiogenesis is characterized by the constriction of the ring of arched membranes, giving rise to the young spermatozoon, which detaches from the residual cytoplasm. The mature spermatozoon of W. capitellata presents most of the classical characters reported in digenean spermatozoa such as two axonemes of different lengths of the 9 + '1' trepaxonematan pattern, nucleus, mitochondrion, two bundles of parallel cortical microtubules and granules of glycogen. However, some peculiarities such as two lateral expansions accompanied by external ornamentation of the plasma membrane and spinelike bodies characterize the mature sperm. Moreover, a new spermatological character is described for the first time, the so-called cytoplasmic ornamented buttons.

Ultrastructural study of spermiogenesis and the spermatozoon of the proteocephalidean cestode Barsonella lafoni de Chambrier et al., 2009, a parasite of the catfish Clarias gariepinus (Burchell, 1822) (Siluriformes, Clariidae)

Spermiogenesis in the proteocephalidean cestode Barsonella lafoni de Chambrier et al., 2009 shows typical characteristics of the type I spermiogenesis. These include the formation of distal cytoplasmic protrusions forming the differentiation zones, lined by cortical microtubules and containing two centrioles. An electron-dense material is present in the apical region of the differentiation zone during the early stages of spermiogenesis. Each centriole is associated to a striated rootlet, being separated by an intercentriolar body. Two free and unequal flagella originate from the centrioles and develop on the lateral sides of the differentiation zone. A median cytoplasmic process is formed between the flagella. Later these flagella rotate, become parallel to the median cytoplasmic process and finally fuse proximodistally with the latter. It is interesting to note that both flagellar growth and rotation are asynchronous. Later, the nucleus enlarges and penetrates into the spermatid body. Finally, the ring of arching membranes is strangled and the young spermatozoon is detached from the residual cytoplasm. The mature spermatozoon presents two axonemes of the 9 +"1" trepaxonematan pattern, crested body, parallel nucleus and cortical microtubules, and glycogen granules. Thus, it corresponds to the type II spermatozoon, described in almost all Proteocephalidea. The anterior extremity of the gamete is characterized by the presence of an apical cone surrounded by the lateral projections of the crested body. An arc formed by some thick and parallel cortical microtubules appears at the level of the centriole. They surround the centriole and later the first axoneme. This arc of electron-dense microtubules disorganizes when the second axoneme appears, and then two parallel rows of thin cortical microtubules are observed. The posterior extremity of the male gamete exhibits some cortical microtubules. This type of posterior extremity has never been described in proteocephalidean cestodes. The ultrastructural features of the spermatozoon/spermiogenesis of the Proteocephalidea species are analyzed and compared.

Spermiogenesis and the spermatozoon ultrastructure of Robphildollfusium fractum (Digenea: Gyliauchenidae), an intestinal parasite of Sarpa salpa (Pisces: Teleostei)

Spermiogenesis in Robphildollfusium fractum begins with the formation of a differentiation zone containing: two centrioles, each bearing striated rootlets, nucleus, several mitochondria and an intercentriolar body constituted by seven electron-dense layers. The two centrioles originate two free flagella growing orthogonally to the median cytoplasmic process. Later, the free flagella rotate and undergo proximodistal fusion with the median cytoplasmic process. Nuclear and mitochondrial migrations occur before this proximodistal fusion. Finally, the young spermatozoon detaches from the residual cytoplasm after the constriction of the ring of arched membranes. The spermatozoon of R. fractum exhibits two axonemes of different length of the 9 +"1" trepaxonematan pattern, nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. Additionally, a shorter axoneme, which does not reach the nuclear region, the presence of an electron-dense material in the anterior spermatozoon extremity and the morphologies of both spermatozoon extremities characterize the mature sperm of R. fractum.

Spermiogenesis and ultrastructure of the spermatozoon of Wardula capitellata (Digenea, Mesometridae), an intestinal parasite of the sparid teleost Sarpa salpa in Senegal

The spermiogenesis process in Wardula capitellata begins with the formation of a differentiation zone containing two centrioles associated with striated rootlets and an intercentriolar body. Each centriole develops into a free flagellum orthogonal to a median cytoplasmic process. Later these flagella rotate and become parallel to the median cytoplasmic process, which already exhibits two electron-dense areas and spinelike bodies before its proximodistal fusion with the flagella. The final stage of the spermiogenesis is characterized by the constriction of the ring of arched membranes, giving rise to the young spermatozoon, which detaches from the residual cytoplasm. The mature spermatozoon of W. capitellata presents most of the classical characters reported in digenean spermatozoa such as two axonemes of different lengths of the 9 + '1' trepaxonematan pattern, nucleus, mitochondrion, two bundles of parallel cortical microtubules and granules of glycogen. However, some peculiarities such as two lateral expansions accompanied by external ornamentation of the plasma membrane and spinelike bodies characterize the mature sperm. Moreover, a new spermatological character is described for the first time, the so-called cytoplasmic ornamented buttons.

The Sottunga-Jurmo shear zone : structure and deformation history of a crustal-scale ductile shear zone in SW Finland

The aim of this study is to gain a better understanding of the structure and the deformation history of a NW-SE trending regional, crustal-scale shear structure in the Åland archipelago, SW Finland, called the Sottunga-Jurmo shear zone (SJSZ). Approaches involving e.g. structural geology, geochronology, geochemistry and metamorphic petrology were utilised in order to reconstruct the overall deformation history of the study area. The study therefore describes several features of the shear zone including structures, kinematics and lithologies within the study area, the ages of the different deformation phases (ductile to brittle) within the shear zone, as well as some geothermobarometric results. The results indicate that the SJSZ outlines a major crustal discontinuity between the extensively migmatized rocks NE of the shear zone and the unmigmatised, amphibolite facies rocks SW of the zone. The main SJSZ shows overall dextral lateral kinematics with a SW-side up vertical component and deformation partitioning into pure shear and simple shear dominated deformation styles that was intensified toward later stages of the deformation history. The deformation partitioning resulted in complex folding and refolding against the SW margin of the SJSZ, including conical and sheath folds, and in a formation of several minor strike-slip shear zones both parallel and conjugate to the main SJSZ in order to accommodate the regional transpressive stresses. Different deformation phases within the study area were dated by SIMS (zircon U-Pb), ID-TIMS (titanite U-Pb) and 40Ar/39Ar (pseudotachylyte wholerock) methods. The first deformation phase within the ca. 1.88 Ga rocks of the study area is dated at ca. 1.85 Ga, and the shear zone was reactivated twice within the ductile regime (at ca. 1.83 Ga and 1.79 Ga), during which the strain was successively increasingly partitioned into the main SJSZ and the minor shear zones. The age determinations suggest that the orogenic processes within the study area did not occur in a temporal continuum; instead, the metamorphic zircon rims and titanites show distinct, 10-20 Ma long breaks in deformation between phases of active deformation. The results of this study further imply slow cooling of the rocks through 600-700ºC so that at 1.79 Ga, 2 the temperature was still at least 600ºC. The highest recorded metamorphic pressures are 6.4-7.1 kbar. At the late stages or soon after the last ductile phase (ca. 1.79 Ga), relatively high-T mylonites and ultramylonites were formed, witnessing extreme deformation partitioning and high strain rates. After the rocks reached lower amphibolite facies to amphibolite-greenschist facies transitional conditions (ca. 500-550ºC), they cooled rapidly, probably due to crustal uplift and exhumation. The shear zone was reactivated at least once within the semi-brittle to brittle regime between ca. 1.79 Ga and 1.58 Ga, as evidenced by cataclasites and pseudotachylytes. In summary, the results of this study suggest that the Sottunga-Jurmo shear zone (and the South Finland shear zone) defines a major crustal discontinuity, and played a central role in accommodating the regional stresses during and after the Svecofennian orogeny.

Sopeutuva suunnittelu : sosiaalisen median suunnitteluprosessi yritysympäristössä: tapaus Alissa

Opinnäytetyö käsittelee sosiaalisen median palvelun suunnittelua yritysympäristössä. Työ perustuu todelliseen projektiin, joka toteutui kevään 2007 aikana Helsingin ammattikorkeakoulu Stadian ja Itella Oyj:n välillä. Projekti toteutettiin käyttämällä perinteistä multimediatuotannon suunnitteluprosessia, joka ei sellaisenaan vastannut projektin erityistarpeisiin. Sosiaalinen media muodostuu internet-sovelluksista, jotka mahdollistavat yhteistoiminnallisia tapoja tuottaa erilaisia sisältöjä, kuten tekstejä, kuvia ja videoita, ja reagoida niihin. Osallistumiseen ja sosiaalisuuteen liittyvien ominaisuuksien vuoksi on vaikeaa suunnitella sosiaalisen median sovellusta noudattamalla perinteistä suunnitteluprosessia, joka perustuu laajamittaiseen alkusuunnitteluun ja käsikirjoittamiseen. Työ tarkastelee vaihtoehtoista suunnittelumallia Getting Realia, joka perustuu pienen ohjelmistoyrityksen 37signalsin työskentelytapoihin. Getting Real soveltaa toistuviin kehitysjaksoihin perustuvaa prosessia, joka suosii pientä mutta monipuolista työryhmää ja dokumentoinnin minimoimista. Työ vertaa perinteistä suunnitteluprosessia ja Getting Realia toteutuneeseen projektiin. Analyysin lopputuloksena on ehdotus suunnitteluprosessiksi, joka yhdistää joustavan sovelluskehityksen ja systemaattisen prosessin, joka syntyy toimeksiantajan tarpeista.

Tectonic-palaeoenvironmental forcing of clay-mineral assemblages in nonmarine settings: the Oligocene-Miocene As Pontes Basin (Spain)

Two small, alluvial-lacustrine subbasins developed during the early restraining overstep stages of the Oligocene-Miocene As Pontes strike-slip Basin (NW Spain). Later, the basin evolved into a restraining bend stage and an alluvial-swamp-dominated depositional framework developed. The palaeobiological record demonstrates that the Oligocene-Miocene palaeoclimate in NW Spain was subtropical, warm and humid to subhumid.

ZONE INTERMÉDIAIRE – Recontruction de l’identité raciale dans L’Amant de Marguerite Duras

Tutkielman aiheena on Marguerite Durasin romaani L’Amant (suom. Rakastaja). Tarkastelen romaanin valkoihoisen nuoren tytön ”rodullisen” identiteetin rakentumista käyttäen heijastuskuvana Toista, tytön ”erirotuista” kiinalaista rakastajaa. Osittain omaelämäkerrallisen romaanin tapahtumat sijoittuvat Ranskan entiseen siirtomaahan, Indokiinaan. Kolonialismin aikainen rotusorto ja valkoisen ”rodun” mytologisen vallan rakentuminen ja konkretisoituminen ovat siis sekä tutkimukseni konteksti että tutkimuskohde. Tarkastelen missä määrin tytön rodullinen identiteetti pitää yllä – tai toisaalta rikkoo – ”rotujen” hierarkkista ajattelua. Tutkimuksen teoreettinen viitekehys on jälkikoloniaalinen (postkoloniaalinen) tutkimus, joka on monitieteellinen itsekriittinen tutkimusmetodi. Tutkimuksen tarkoituksena on kyseenalaistaa länsimaissa vallitsevia kategorioita. Päälähteinä käytetään mm. Dyerin (1997), Memmin (1994), Todorovin (1989), Girodin (2004), Hallin (1992, 1996), Derridan (1967, 1972, 1992), Shevoryn (2000), Dufourmentellen (2003) ja De Beauvoirin (1947) teoksia. Tutkimuksen keskeinen käsite on välitila, johon teoksen nuori tyttö voidaan tutkimustulosteni mukaan sijoittaa. Tyttö häilyy eräänlaisessa välitilassa valkoisen ja keltaisen ”rodun” välillä: hän tuntee kuuluvansa tavallaan molempiin ”rotuihin”, sillä hän on syntynyt Indokiinassa, puhuu paikallista kieltä ja suhtautuu paikallisiin tasavertaisemmin kuin valkoihoinen eliitti, mutta kuuluu kuitenkin syntyperältään valkoiseen ”rotuun”. Valkoisuutta ei usein määritellä ”roduksi”, vaikka muiden kuin valkoihoisten kohdalla ”rotu” määritellään joko negatiivisten tai positiivisten typologioiden mukaisesti. Tästä syystä valkoiset nähdään helposti ihmisyyden normina neutraaliksi väitetyssä valkoisten diskriminoivassa diskurssissa. L’Amant’ssa valkoisuus on näkemykseni mukaan kuitenkin näkyvää ja valkoisuuden valtaa kyseenalaistavaa. Valkoisen tytön perhe on valkoisten kolonialistien arvoasteikon alimmalla portaalla, sillä perhe on köyhä ja valkoisten valta rakentui suurelta osin siirtomaaisäntien taloudellispoliittiseen ylivaltaan. Koska tytön perheellä ei ole tarpeeksi varaa elitistiseen herruuteen, eliitti paheksuu tytön perhettä avoimesti erityisesti ”rotujen” välisen kielletyn suhteen tullessa julki, jolloin tyttö eristetään valkoisesta yhteisöstä. Kiinalainen puolestaan on miljardöörin perijä ja tämä suo hänelle hieman korkeamman aseman ”rotujen” hierarkiassa, vaikka hänen vaurautensa toisaalta uhkaakin valkoista valtaa. Myös romaanin monella tapaa konventioita rikkova seksuaalisuus on osa kielletyn suhteen välistä valtapeliä. Kirjailija strukturoi uudelleen patriarkaalisen sukupuolen rakentumisen feminisoimalla kiinalaisen miehen, sillä muussa tapauksessa hänen maskuliinisuutensa saattaisi saada ylivallan tytöstä, joka on sukupuolisesti Toinen.

Bulletin des armées de la République : réservé à la zone des armées

1915/01/04 (N60)-1915/06/30 (N110).