Population Dynamics at the Range Margin : Implications of Climate Change on Sublittoral Blue Mussels (Mytilus trossulus)

Examining changes in abundance and demographic rates at species distribution margins may provide the first signs of broader species responses to environmental change. Still, the joint impact of space and time have remained relatively unstudied in most marginal regions. In order to examine the influence of climate variability on mussel distribution patterns, we monitored three sublittoral and marginal blue mussel (Mytilus trossulus) populations, spaced along a salinity gradient. Densities and biomasses peaked toward the saltier parts of the study area and showed relatively larger variations toward the low saline edge. Temporally, the areas showed a consistent increase in abundance after a synchronized large-scale recruitment event, which was followed by a decline in population size, occurring much faster toward the very range edge. Salinity, temperature, winter severity, and wave exposure explained most of the spatiotemporal variation in mussel abundances and adults showed positive effects on recruit abundance. We show empirically that the dynamics of edge populations are not driven by large changes in climate variables but that small spatial and temporal changes in key environmental variables have large and non-linear population level effects. Our results also show that fluctuating recruitment is a key factor for population stability affecting the storage potential of marginal populations, which dramatically decrease toward the edge. Our study provides a window into future population patterns and processes that drive marginal mussel populations in an altered sea characterized by rising temperature and declining salinity.Peer reviewe

Control System Commissioning of Fully Levitated Bearingless Machine

The bearingless permanent magnet synchronous motor (BPMSM) is a compact motor structure that combines the motoring and bearing functions based on well-designed integrated windings for generating both torque and magnetic suspension force. In order to achieve a successful high-performance control design for the BPMSM, an adequate model of the rotor dynamics is essential. This paper proposes simplified multiple-input and multiple-output (MIMO) control approaches, namely the pole placement and the linear-quadratic regulator (LQR), that allow to carry out identification experiments in full levitation. Additionally, the stability of the MIMO levitation controller is verified with the rotation tests. Compared with other recently published works, the novelty of this paper is to experimentally demonstrate that a stable fully levitated five-degrees-of-freedom (5-DOF) operation of a bearingless machine can be achieved by the proposed approach, and thereby, options for commissioning of such a system are obtained

Regulatory effects of PRF and titanium surfaces on cellular adhesion, spread, and cytokine expressions of gingival keratinocytes

Dental implant material has an impact on adhesion and spreading of oral mucosal cells on its surface. Platelet-rich fibrin (PRF), a second-generation platelet concentrate, can enhance cell proliferation and adhesion. The aim was to examine the regulatory effects of PRF and titanium surfaces on cellular adhesion, spread, and cytokine expressions of gingival keratinocytes. Human gingival keratinocytes were cultured on titanium grade 4, titanium grade 5 (Ti5), and HA discs at 37 °C in a CO2 incubator for 6 h and 24 h, using either elutes of titanium-PRF (T-PRF) or leukocyte and platelet-rich fibrin (L-PRF), or mammalian cell culture medium as growth media. Cell numbers were determined using a Cell Titer 96 assay. Interleukin (IL)-1β, IL-1Ra, IL-8, monocyte chemoattractant protein (MCP)-1, and vascular endothelial growth factor (VEGF) expression levels were measured using the Luminex® xMAP™ technique, and cell adhesion and spread by scanning electron microscopy. Epithelial cell adhesion and spread was most prominent to Ti5 surfaces. L-PRF stimulated cell adhesion to HA surface. Both T-PRF and L-PRF activated the expressions of IL-1 β, IL-8, IL-1Ra, MCP-1, and VEGF, T-PRF being the strongest activator. Titanium surface type has a regulatory role in epithelial cell adhesion and spread, while PRF type determines the cytokine response.</p

PTPRD and CNTNAP2 as markers of tumor aggressiveness in oligodendrogliomas

Oligodendrogliomas are typically associated with the most favorable prognosis among diffuse gliomas. However, many of the tumors progress, eventually leading to patient death. To characterize the changes associated with oligodendroglioma recurrence and progression, we analyzed two recurrent oligodendroglioma tumors upon diagnosis and after tumor relapse based on whole-genome and RNA sequencing. Relapsed tumors were diagnosed as glioblastomas with an oligodendroglioma component before the World Health Organization classification update in 2016. Both patients died within 12 months after relapse. One patient carried an inactivating POLE mutation leading to a clearly hypermutated progressed tumor. Strikingly, both relapsed tumors carried focal chromosomal rearrangements in PTPRD and CNTNAP2 genes with associated decreased gene expression. TP53 mutation was also detected in both patients after tumor relapse. In The Cancer Genome Atlas (TCGA) diffuse glioma cohort, PTPRD and CNTNAP2 expression decreased by tumor grade in oligodendrogliomas and PTPRD expression also in IDH-mutant astrocytomas. Low expression of the genes was associated with poor overall survival. Our analysis provides information about aggressive oligodendrogliomas with worse prognosis and suggests that PTPRD and CNTNAP2 expression could represent an informative marker for their stratification.publishedVersionPeer reviewe

The N-glycome of human embryonic stem cells

<p>Abstract</p> <p>Background</p> <p>Complex carbohydrate structures, glycans, are essential components of glycoproteins, glycolipids, and proteoglycans. While individual glycan structures including the SSEA and Tra antigens are already used to define undifferentiated human embryonic stem cells (hESC), the whole spectrum of stem cell glycans has remained unknown. We undertook a global study of the asparagine-linked glycoprotein glycans (N-glycans) of hESC and their differentiated progeny using MALDI-TOF mass spectrometric and NMR spectroscopic profiling. Structural analyses were performed by specific glycosidase enzymes and mass spectrometric fragmentation analyses.</p> <p>Results</p> <p>The data demonstrated that hESC have a characteristic N-glycome which consists of both a constant part and a variable part that changes during hESC differentiation. hESC-associated N-glycans were downregulated and new structures emerged in the differentiated cells. Previously mouse embryonic stem cells have been associated with complex fucosylation by use of SSEA-1 antibody. In the present study we found that complex fucosylation was the most characteristic glycosylation feature also in undifferentiated hESC. The most abundant complex fucosylated structures were Le^xand H type 2 antennae in sialylated complex-type N-glycans.</p> <p>Conclusion</p> <p>The N-glycan phenotype of hESC was shown to reflect their differentiation stage. During differentiation, hESC-associated N-glycan features were replaced by differentiated cell-associated structures. The results indicated that hESC differentiation stage can be determined by direct analysis of the N-glycan profile. These results provide the first overview of the N-glycan profile of hESC and form the basis for future strategies to target stem cell glycans.</p

Ienepiteelisolujen kiinnittyminen ja sytokiiniaktiivisuuden mittaaminen titaani- ja hydroksiapatiittipinnoilla ja sen muokkaaminen runsasverihiutaleisella fibriinillä

Kliinisesti on havaittu, että hammasimplanttien ja niitä ympäröivän epiteelin välille muodostuvan sidoksen puute altistaa usein peri-implantiitille ja sen johdosta myös implantin menetykselle. Implantin titaanipinnan karhennus joko mekaanisesti tai kemiallisesti saattaa edistää epiteelin kiinnittymistä implantin pinnalle, mutta käytännön sovelluksia on olemassa niukasti. Runsaasti verihiutaleita sisältävän fibriinin (engl. platelet-rich fibrin, PRF) on havaittu lisäävän epiteelisolujen proliferaatiota, mikä näin ollen myös edistää niiden kiinnittymistä. Tutkimuksemme tarkoituksena oli vertailla in vitro -olosuhteissa PRF:n vaikutusta epiteelisolujen kiinnittymiseen ja adheesioon hammasta simuloivan hydroksiapatiitin ja hammasimplanteissa käytettyjen titaanimateriaalien pinnoille. Epiteelisolut kasvatettiin hydroksiapatiitti- ja titaanikiekkojen (luokan 4 titaani, Ti4 ja luokan 5 titaani, Ti5) päällä 6 tunnin ja 24 tunnin ajan kolmessa erilaisessa elatusaineessa. Elatusaineina käytettiin: titaaniputkessa valmistettua runsasverihiutaleista fibriiniä (T-PRF), runsas leukosyyttistä ja verihiutaleista fibriiniä (L-PRF) sekä kaupallista elatusainetta ilman seerumia (SFM-X). Näytteiden solumäärät laskettiin kaupallisella laskimella. Eri sytokiinien eli interleukiini (IL)-1β, IL-1Ra, IL-8, monosyytti kemoattraktantti proteiinin (MCP)-1 sekä vaskulaarisen endoteelikasvutekijän (VEGF) tasot määritettiin käyttämällä Luminex xMAP™-tekniikkaa. Solujen kiinnittyminen ja adheesio kiekkojen pinnoille kuvattiin pyyhkäisyelektronimikroskoopin avulla. Eri titaanilaatujen välillä havaittiin selviä eroja, kun arvioitiin visuaalisesti solujen kiinnittymistä ja leviämistä. Tutkimuksessa käytetyistä erilaisista elatusaineista T-PRF sai aikaan suurimman sytokiiniaktiivisuuden näytteissä. Kokonaisuudessaan voidaan todeta, että muokkaamalla implanttien titaanin koostumusta, voidaan mahdollisesti saada ienepiteelisoluille paremmat edellytykset kiinnittymiseen implanttihoidossa. Myös samanaikaisesti voidaan todeta, että PRF aktivoi voimakkaasti sytokiinien aktiivisuutta epiteelisoluissa