Thermodynamics of bcc metals in phase-field-crystal models

We examine the influence of different forms of the free-energy functionals used in the phase-field-crystal (PFC) model, and compare them with the second-order density-functional theory (DFT) of freezing, by using bcc iron as an example case. We show that there are large differences between the PFC and the DFT and it is difficult to obtain reasonable parameters for existing PFC models directly from the DFT. Therefore, we propose a way of expanding the correlation function in terms of gradients that allows us to incorporate the bulk modulus of the liquid as an additional parameter in the theory. We show that this functional reproduces reasonable values for both bulk and surface properties of bcc iron, and therefore it should be useful in modeling bcc materials. As a further demonstration, we also calculate the grain boundary energy as a function of misorientation for a symmetric tilt boundary close to the melting transition.Peer reviewe

Nest cover and faecal glucocorticoid metabolites are linked to hatching success and telomere length in breeding Common Eiders (Somateria mollissima)

Habitat-associated crypsis may affect perceived predation vulnerability, selecting for different predator avoidance strategies. Glucocorticoids could mediate the adjustment of escape responses to the extent of crypsis, introducing an overlooked source of variation in glucocorticoid-fitness relationships. However, prolonged exposure to elevated glucocorticoids may be costly, leading to accelerated telomere loss and, consequently, senescence. Here, we examined how nest cover and immunoreactive faecal glucocorticoid metabolite (fGCM) levels are linked to hatching success and telomere length in breeding female Common Eiders (Somateria mollissima (L., 1758)). We hypothesized that the degree of nest crypsis, reflecting differences in perceived predation risk, would moderate the relationship between reproductive success and fGCM levels. We also expected that telomere length would be shorter in birds with higher glucocorticoid concentration. Results showed that individuals with high fGCM levels had higher hatching success in nests with low cover, while low fGCM levels were more successful in well-concealed nests. We found that shorter telomeres were associated with high fGCM in nesting sites offering little cover and with low fGCM in well-concealed ones. This study provides the first evidence of habitat-dependent moderation of the relationships between stress physiology, telomere length and hatching success.Peer reviewe

Phase field crystal study of symmetric tilt grain boundaries of iron

We apply the phase field crystal model to study the structure and energy of symmetric tilt grain boundaries of bcc iron in 3D. The parameters for the model are obtained by using a recently developed eight-order fitting scheme [A. Jaatinen et al., (2009)]. The grain boundary free energies we obtain from the model are in good agreement with previous results from molecular dynamics simulations and experiments

DDFT calibration and investigation of an anisotropic phase-field crystal model

The anisotropic phase-field crystal model recently proposed and used by Prieler et al. [J. Phys.: Condens. Matter 21, 464110 (2009)] is derived from microscopic density functional theory for anisotropic particles with fixed orientation. Further its morphology diagram is explored. In particular we investigated the influence of anisotropy and undercooling on the process of nucleation and microstructure formation from atomic to the microscale. To that end numerical simulations were performed varying those dimensionless parameters which represent anisotropy and undercooling in our anisotropic phase-field crystal (APFC) model. The results from these numerical simulations are summarized in terms of a morphology diagram of the stable state phase. These stable phases are also investigated with respect to their kinetics and characteristic morphological features.Comment: It contain 13 pages and total of 7 figure

”Ei voi aivan pelkästään luokkakuvan ja tikkataulun perusteella antaa numeroita”:kuudennen luokan oppilaiden ja heidän liikunnanopettajiensa käsityksiä ja kokemuksia liikunnan oppilasarvioinnista

Tiivistelmä. Tässä pro gradu -tutkielmassa tarkastellaan opettajien ja oppilaiden käsityksiä ja kokemuksia liikunnan oppilasarvioinnista. Tutkimuksen tavoitteena on selvittää kuudennen luokan oppilaiden ja heidän opettajiensa käsityksiä ja kokemuksia liikunnan oppilasarvioinnin oikeudenmukaisuudesta ja sen toteutumisesta. Lisäksi tutkimuksen tarkoituksena on vertailla oppilaiden ja opettajien käsitysten ja kokemusten yhteneväisyyksiä ja eroavaisuuksia. Tutkimus on laadullinen tapaustutkimus, jossa on myös kvantitatiivisen tutkimuksen piirteitä. Tutkimuksen lähestymistapana on sekä fenomenografia että fenomenologia. Tutkimusjoukon muodostivat erään Pohjois-Pohjanmaan koulun kuudennen luokan oppilaat sekä heidän liikunnanopettajansa. Opettajien aineisto (n=4) kerättiin teemahaastattelulla ja oppilaiden aineisto (n=51) kyselylomakkeen avulla kevään 2013 aikana. Aineiston analyysissa käytettiin teoriaohjaavaa sisällönanalyysiä sekä SPSS 20 -ohjelman tilastollisia testejä määrällisen aineiston analysoinnissa. Teorian ja tutkimustulosten mukaan on todettavissa, että liikunnan oppilasarvioinnin oikeudenmukainen toteuttaminen on haastavaa. Objektiivista arviointia on mahdotonta toteuttaa arvioijan henkilökohtaisten mieltymysten vuoksi. Liikunnanopettajat kuitenkin pyrkivät oikeudenmukaisen arvioinnin tekemiseen parhaansa mukaan. Suurin osa oppilaista kokikin saaneensa oikeudenmukaista oppilaan arviointia. Yhtenä huomattavana asiana nousi kuitenkin esiin suosiminen ja henkilökemioiden yhteys arviointiin. Opettajien ja oppilaiden mukaan henkilökemioilla ja persoonallisuuspiirteillä on vaikutusta arviointiin, jolloin arvioinnista muodostuu epäoikeudenmukaista. Käsitykset arviointikriteereistä vaihtelivat opettajien ja oppilaiden keskuudessa. Myös opettajien käyttämät arviointikriteerit poikkesivat toisistaan. Naisopettajat painottavat miesopettajia enemmän liikunnan lajitaitoja, kun taas miehet korostavat asenteen merkitystä. Oppilaiden tulisi tietää opettajiensa arviointikriteerit, mutta tutkittavien oppilaiden mukaan heillä ei ole riittävää käsitystä niistä. Opettajien arviointikäytänteet eivät ole yhteneväisiä, joten annettavien arvosanojen perusteet vaihtelevat opettajakohtaisesti. Opettajat pohtivat liikunnan arvioinnin tarpeellisuutta eikä yhtenevää näkemystä arviointitavasta ollut. Oppilaat säilyttäisivät arvioinnin liikunnassa, mutta mielipiteet arviointitavasta jakaantuivat numeroarviointiin sekä sanallisen ja numeroarvioinnin yhdistelmään. Tutkimuksen tulokset tuovat lisätietoa liikunnan oppilasarvioinnin haastavuudesta ja oikeudenmukaisen arvioinnin ongelmakohdista. Tutkimuksen tulokset eivät ole tilastollisesti yleistettävissä, sillä tutkimuksessa tarkasteltiin vain pienen joukon käsityksiä ja kokemuksia liikunnan oppilasarvioinnin oikeudenmukaisuudesta ja arviointikäytänteistä. Tulokset antavat kuitenkin viitteitä siitä, ettei liikunnan oppilasarviointi ole koskaan täysin oikeudenmukaista, sillä arviointikäytänteet vaihtelevat eri opettajien kesken

Controlling crystal symmetries in phase-field crystal models

We investigate the possibility to control the symmetry of ordered states in phase-field crystal models by tuning nonlinear resonances. In two dimensions, we find that a state of square symmetry as well as coexistence between squares and hexagons can be easily obtained. In contrast, it is delicate to obtain coexistence of squares and liquid. We develop a general method for constructing free energy functionals that exhibit solid-liquid coexistence with desired crystal symmetries. As an example, we develop a free energy functional for square-liquid coexistence in two dimensions. A systematic analysis for determining the parameters of the necessary nonlinear terms is provided. The implications of our findings for simulations of materials with simple cubic symmetry are discussed.Comment: 19 pages, 6 figure

Glycoprotein YKL-40 Is Elevated and Predicts Disease Severity in Puumala Hantavirus Infection

Most cases of hemorrhagic fever with renal syndrome (HFRS) in Europe are caused by the Puumala hantavirus (PUUV). Typical features of the disease are increased vascular permeability, acute kidney injury (AKI), and thrombocytopenia. YKL-40 is an inflammatory glycoprotein involved in various forms of acute and chronic inflammation. In the present study, we examined plasma YKL-40 levels and the associations of YKL-40 with disease severity in acute PUUV infection. A total of 79 patients treated in Tampere University Hospital during 2005–2014 were studied. Plasma YKL-40 was measured in the acute phase, the recovery phase, and one year after hospitalization. Plasma YKL-40 levels were higher during the acute phase compared to the recovery phase and one year after hospitalization (median YKL-40 142 ng/mL, range 11–3320, vs. 45 ng/mL, range 15–529, vs. 32 ng/mL, range 3–213, p < 0.001). YKL-40 level was correlated with the length of hospital stay (r = 0.229, p = 0.042), the levels of inflammatory markers—that is, blood leukocytes (r = 0.234, p = 0.040), plasma C-reactive protein (r = 0.332, p = 0.003), and interleukin-6 (r = 0.544, p < 0.001), and maximum plasma creatinine level (r = 0.370, p = 0.001). In conclusion, plasma YKL-40 levels were found to be elevated during acute PUUV infection and correlated with the overall severity of the disease, as well as with the degree of inflammation and the severity of AKI

Glycoprotein YKL-40 Is Elevated and Predicts Disease Severity in Puumala Hantavirus Infection

Most cases of hemorrhagic fever with renal syndrome (HFRS) in Europe are caused by the Puumala hantavirus (PUUV). Typical features of the disease are increased vascular permeability, acute kidney injury (AKI), and thrombocytopenia. YKL-40 is an inflammatory glycoprotein involved in various forms of acute and chronic inflammation. In the present study, we examined plasma YKL-40 levels and the associations of YKL-40 with disease severity in acute PUUV infection. A total of 79 patients treated in Tampere University Hospital during 2005–2014 were studied. Plasma YKL-40 was measured in the acute phase, the recovery phase, and one year after hospitalization. Plasma YKL-40 levels were higher during the acute phase compared to the recovery phase and one year after hospitalization (median YKL-40 142 ng/mL, range 11–3320, vs. 45 ng/mL, range 15–529, vs. 32 ng/mL, range 3–213, p < 0.001). YKL-40 level was correlated with the length of hospital stay (r = 0.229, p = 0.042), the levels of inflammatory markers—that is, blood leukocytes (r = 0.234, p = 0.040), plasma C-reactive protein (r = 0.332, p = 0.003), and interleukin-6 (r = 0.544, p < 0.001), and maximum plasma creatinine level (r = 0.370, p = 0.001). In conclusion, plasma YKL-40 levels were found to be elevated during acute PUUV infection and correlated with the overall severity of the disease, as well as with the degree of inflammation and the severity of AKI

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