"Towards 'a real reunion'?" : Archbishop Aleksi Lehtonen's efforts for closer relations with the Church of England 1945–1951

Mika KT Pajusen väitös "Towards 'a real reunion'?" – Archbishop Aleksi Lehtonen's efforts for closer relations with the Church of England 1945–1951 on yleiseen kirkkohistoriaan lukeutuva tutkimus Englannin kirkon ja Suomen evankelis-luterilaisen kirkon välisistä suhteista Aleksi Lehtosen arkkipiispakaudella 1945–1951. Suhteita on tutkittu kolmesta näkökulmasta: ekumeenisesta, poliittisesta ja kirkkopoliittisesta. Tutkimuskausi alkaa pastori H.M. Waddamsin joulukuussa 1944 Suomeen tekemän vierailun jälkimainingeista ja päättyy arkkipiispa Lehtosen kuolemaan pääsiäisenä 1951. Kirkollisten suhteiden kehitystä rytmittivät lukuisat vierailut, jotka osoittivat Englannin kirkon asenteen muuttumisen sodan aikaisesta neuvostomyönteisyydestä kylmän sodan aikaiseen täysin vastakkaiseen kantaan. Englantilaiset vieraat kohtasivat Suomessa sekä kirkon että yhteiskunnan ylimmän johdon. Molemmat maat olivat valmiita tukemaan hyviä kirkollisia suhteita tilanteen niin salliessa, joskaan eivät kovin suunnitelmallisesti. Suomen evankelis-luterilainen kirkko käytti hyviä suhteita Englannin kirkkoon saadakseen tukea ja ymmärrystä omalle kirkolleen ja yhteiskunnalleen kokemaansa Neuvostoliiton uhkaa vastaan erityisesti vaaran vuosina 1944–1948. Englannin kirkko halusi tukea suomalaista sisarkirkkoaan, mutta varoi, ettei tuottaisi tuellaan enemmän haittaa kuin hyötyä suhteessa Neuvostoliittoon. Sodan jälkeinen ekumeeninen jälleenrakentaminen lähensi kirkkoja toisiinsa. Lehtonen pyrki jatkamaan 1930-luvun kirkkojen välisiä, ehtoollisvieraanvaraisuuden saavuttaneita neuvotteluita kohti täyttä kirkollista yhteyttä. Häntä motivoi sekä evankelis-katolinen teologia että pyrkimys tukea oman maan ja kirkon läntisiä yhteyksiä. Tämä haastoi Englannin kirkon ekumeenisen linjan, joka Suomen kirkon sijasta pyrki jatkamaan neuvotteluja Tanskan, Norjan ja Islannin luterilaisten kirkkojen kanssa, joilla ei vielä ollut virallista ekumeenista sopimusta Englannin kirkon kanssa. Lehtosen pyrkimyksistä huolimatta Englannin kirkko päätyi jättämään Suomen tilanteen hautumaan. Sillä se tarkoitti suhteiden koetinkivenä olleen historiallisen piispuuden leviämistä läpi Suomen kirkon ennen kuin katsoi olevansa valmis jatkamaan kohti täyttä kirkollista yhteyttä. Molemmissa kirkoissa vaikutti pieni, innokkaiden, lähempiä suhteita toivoneiden kirkollisten vaikuttajien ydinjoukko. Englantilaisia Suomen-ystäviä motivoi tarve auttaa Suomea hankalassa poliittisessa tilanteessa. Suomessa arkkipiispa Lehtonen tuki korkeakirkollista liturgista liikettä, jolla oli läheinen yhteys anglikaanisuuteen, mutta joka sai vastaansa vanhoilliset pietistit. Suomen kirkon yleinen mielipide asettui etupäässä pietistiselle kannalle, jolle anglikaanisuus näyttäytyi teologisesti sekä liian katolisena että liian reformoituna. Kirkolliset suhteet tasaantuivat vuoden 1948 Lambeth-konferenssin jälkeen, joka rohkaisi anglikaanisia kirkkoja hyväksymään 1930-luvun neuvottelujen lähempiin kirkollisiin suhteisiin tähtäävät suositukset. Lehtonen näytti tyytyvän tähän. Samaan aikaan lähempää kirkollista kanssakäymistä tukenut ekumeeninen jälleenrakennus tuli tiensä päähän. Lehtonen jatkoi läheisempien suhteiden edistämistä, mutta hänen intonsa hiipui yhdessä heikkenevän terveydentilan kanssa. Osoituksena Lehtosen linjan kapeudesta Suomen evankelis-luterilaisen kirkon piispoista ei löytynyt hänen kuoltuaan ketään, joka olisi jatkanut hänen aktiivista anglikaanimyönteistä linjaansa.

Uskon lyhyt oppimäärä : Suomen keskiaikaisten kivikirkkojen kalkkimaalausten välittämä raamattukuva

Tämä tutkielma on kokoava tutkimus Raamatusta nousevista kuva-aiheista, joita esiintyy 1400-luvun lopun ja 1510-luvun henkilömaalauksissa Suomen keskiaikaisissa kivikirkoissa. Aikaisempi Suomen keskiaikaista kirkkotaidetta koskeva tutkimus on ollut pääosin taidehistoriallista. Tutkielma pyrkii vastaamaan kysymykseen, millaisena Raamattu näyttäytyy suomalaisissa keskiaikaisissa kirkkomaalauksissa. Tutkimuskohteena ovat 1470–1490 –luvuilla Suomessa työskennelleen Taivassalon maalariryhmän maalaamat kirkot sekä 1500-luvun alussa maalatut kuvasarjat Länsi-Uudellamaalla, Hattulassa, Raumalla ja Pyhtäällä. Vanhasta testamentista peräisin olevia kuva-aiheita on vain 1510-luvulla tehdyissä maalaussarjoissa, joissa ne toimivat Kristukseen liittyvänä vertauskuvina ja hänen toimintansa selittäjinä. Vanhasta testamentista Suomen keskiaikaisten kirkkojen seinille on päässyt vanhan liiton keskeisiä henkilöitä, kuten Mooses, Daniel, Iisak ja Simson. Pelastushistoriaan kiinteästi liittyvät luominen ja syntiinlankeemus esiintyvät maalaussarjoissa kirkkosalin seinällä. Sen sijaan Kristuksen esikuvat löytyvät kirkkojen kattoholveista. Neitsyt Mariaan liittyvistä kuva-aiheista valtaosa on peräisin muualta kuin Raamatusta. Maalauksissa, jotka pohjaavat Raamattuun, Maria liittyy kiinteästi poikaansa Jeesukseen. Maria on yhdistetty Jeesuksen elämän loppuun ja alkuun; syntymäkertomuksiin ja kärsimykseen, kuolemaan ja ylösnousemukseen. Maria-aiheita esiintyy sekä Taivassalon ryhmän maalauksissa että 1500-luvun maalaussarjoissa. Jeesuksen elämä on havainnollistettu kalkkimaalauksissa yksityiskohtaisesti, etenkin Jeesuksen kärsimyshistorian osalta. Vain harvassa kirkossa Jeesus ei ole päässyt lainkaan osaksi maalauskokonaisuutta. Maalauksista välittyy kuva Jeesuksesta, joka etsii aikuisen ihmisen uskoa. Niin ikään maalausten Jeesus on pikemminkin ihmiskuntaa pelastamaan tullut taivaallinen Kristus kuin mies Jeesus Nasaretilainen. Viimeistä tuomiota esittävät maalauskokonaisuudet sekä evankelistasymbolit poikkeavat hyvin vähän eri kirkoissa. Molempien aiheiden kuvaamistavat olivat siinä määrin vakiintuneet, että erot kirkkojen välillä selittyvät käytetyillä mallikirjoilla ja maalareiden taidoilla. Viimeinen tuomio ja evankelista-symbolit kuuluvat suosituimpien kuva-aiheiden joukkoon. Jeesuksen opetuslapset on useassa kirkossa esitetty niin sanottuna credo-sarjana sekä osana kirkon pyhimysjoukkoa. Käsitellyn aineiston pohjalta nousee kuva Raamatusta, joka on lyhennetty ja tiivistetty. Keskiaikaisiin kuvaraamattuihin ja hartauskirjoihin verrattuna suomalaisissa kalkkimaalauksissa pitäydytään pitkälle olennaisessa kertomuksessa, eikä Jeesuksen elämää turhan tähden lähdetä selostamaan vaikeaselkoisin typologioin. Kuvakertomukset ovat ajan hengen mukaisesti vahvasti Kristus-keskeisiä. Kuitenkin kokonaisuutena Vanha testamentti pääsee maalauksissa paremmin esille kuin Uusi testamentti, josta huomio kiinnittyy lähes yksinomaan evankeliumeihin.

Sleep quantity and quality during heat-based training and the effects of cold-water immersion recovery

- Introduction Heat-based training (HT) is becoming increasingly popular as a means of inducing acclimation before athletic competition in hot conditions and/or to augment the training impulse beyond that achieved in thermo-neutral conditions. Importantly, current understanding of the effects of HT on regenerative processes such as sleep and the interactions with common recovery interventions remain unknown. This study aimed to examine sleep characteristics during five consecutive days of training in the heat with the inclusion of cold-water immersion (CWI) compared to baseline sleep patterns. - Methods Thirty recreationally-trained males completed HT in 32 ± 1 °C and 60% rh for five consecutive days. Conditions included: 1) 90 min cycling at 40 % power at VO2max (Pmax) (90CONT; n = 10); 90 min cycling at 40 % Pmax with a 20 min CWI (14 ± 1 °C; 90CWI; n = 10); and 30 min cycling alternating between 40 and 70 % Pmax every 3 min, with no recovery intervention (30HIT; n = 10). Sleep quality and quantity was assessed during HT and four nights of 'baseline' sleep (BASE). Actigraphy provided measures of time in and out of bed, sleep latency, efficiency, total time in bed and total time asleep, wake after sleep onset, number of awakenings, and wakening duration. Subjective ratings of sleep were also recorded using a 1-5 Likert scale. Repeated measures analysis of variance (ANOVA) was completed to determine effect of time and condition on sleep quality and quantity. Cohen's d effect sizes were also applied to determine magnitude and trends in the data. - Results Sleep latency, efficiency, total time in bed and number of awakenings were not significantly different between BASE and HT (P > 0.05). However, total time asleep was significantly reduced (P = 0.01; d = 1.46) and the duration periods of wakefulness after sleep onset was significantly greater during HT compared with BASE (P = 0.001; d = 1.14). Comparison between training groups showed latency was significantly higher for the 30HIT group compared to 90CONT (P = 0.02; d = 1.33). Nevertheless, there were no differences between training groups for sleep efficiency, total time in bed or asleep, wake after sleep onset, number of awakenings or awake duration (P > 0.05). Further, cold-water immersion recovery had no significant effect on sleep characteristics (P > 0.05). - Discussion Sleep plays an important role in athletic recovery and has previously been demonstrated to be influenced by both exercise training and thermal strain. Present data highlight the effect of HT on reduced sleep quality, specifically reducing total time asleep due to longer duration awake during awakenings after sleep onset. Importantly, although cold water recovery accelerates the removal of thermal load, this intervention did not blunt the negative effects of HT on sleep characteristics. - Conclusion Training in hot conditions may reduce both sleep quantity and quality and should be taken into consideration when administering this training intervention in the field.

Identification of IDUA and WNT16 phosphorylation-related non-synonymous polymorphisms for bone mineral density in meta-analyses of genome-wide association studies

Protein phosphorylation regulates a wide variety of cellular processes. Thus, we hypothesize that single-nucleotide polymorphisms (SNPs) that may modulate protein phosphorylation could affect osteoporosis risk. Based on a previous conventional genome-wide association (GWA) study, we conducted a three-stage meta-analysis targeting phosphorylation-related SNPs (phosSNPs) for femoral neck (FN)-bone mineral density (BMD), total hip (HIP)-BMD, and lumbar spine (LS)-BMD phenotypes. In stage 1, 9593 phosSNPs were meta-analyzed in 11,140 individuals of various ancestries. Genome-wide significance (GWS) and suggestive significance were defined by α = 5.21 × 10–6 (0.05/9593) and 1.00 × 10–4, respectively. In stage 2, nine stage 1–discovered phosSNPs (based on α = 1.00 × 10–4) were in silico meta-analyzed in Dutch, Korean, and Australian cohorts. In stage 3, four phosSNPs that replicated in stage 2 (based on α = 5.56 × 10–3, 0.05/9) were de novo genotyped in two independent cohorts. IDUA rs3755955 and rs6831280, and WNT16 rs2707466 were associated with BMD phenotypes in each respective stage, and in three stages combined, achieving GWS for both FN-BMD (p = 8.36 × 10–10, p = 5.26 × 10–10, and p = 3.01 × 10–10, respectively) and HIP-BMD (p = 3.26 × 10–6, p = 1.97 × 10–6, and p = 1.63 × 10–12, respectively). Although in vitro studies demonstrated no differences in expressions of wild-type and mutant forms of IDUA and WNT16B proteins, in silico analyses predicts that WNT16 rs2707466 directly abolishes a phosphorylation site, which could cause a deleterious effect on WNT16 protein, and that IDUA phosSNPs rs3755955 and rs6831280 could exert indirect effects on nearby phosphorylation sites. Further studies will be required to determine the detailed and specific molecular effects of these BMD-associated non-synonymous variants. © 2015 American Society for Bone and Mineral Research.

The role of lakes in carbon cycling in boreal catchments

Lakes are an important component of ecosystem carbon cycle through both organic carbon sequestration and carbon dioxide and methane emissions, although they cover only a small fraction of the Earth's surface area. Lake sediments are considered to be one of rather perma-nent sinks of carbon in boreal regions and furthermore, freshwater ecosystems process large amounts of carbon originating from terrestrial sources. These carbon fluxes are highly uncer-tain especially in the changing climate. -- The present study provides a large-scale view on carbon sources and fluxes in boreal lakes situated in different landscapes. We present carbon concentrations in water, pools in lake se-diments, and carbon gas (CO2 and CH4) fluxes from lakes. The study is based on spatially extensive and randomly selected Nordic Lake Survey (NLS) database with 874 lakes. The large database allows the identification of the various factors (lake size, climate, and catchment land use) determining lake water carbon concentrations, pools and gas fluxes in different types of lakes along a latitudinal gradient from 60oN to 69oN. Lakes in different landscapes vary in their carbon quantity and quality. Carbon (C) content (total organic and inorganic carbon) in lakes is highest in agriculture and peatland dominated areas. In peatland rich areas organic carbon dominated in lakes but in agricultural areas both organic and inorganic C concentrations were high. Total inorganic carbon in the lake water was strongly dependent on the bedrock and soil quality in the catchment, especially in areas where human influence in the catchment is low. In inhabited areas both agriculture and habitation in the catchment increase lake TIC concentrations, since in the disturbed soils both weathering and leaching are presumably more efficient than in pristine areas. TOC concentrations in lakes were related to either catchment sources, mainly peatlands, or to retention in the upper watercourses. Retention as a regulator of the TOC concentrations dominated in southern Finland, whereas the peatland sources were important in northern Finland. The homogeneous land use in the north and the restricted catchment sources of TOC contribute to the close relationship between peatlands and the TOC concentrations in the northern lakes. In southern Finland the more favorable climate for degradation and the multiple sources of TOC in the mixed land use highlight the importance of retention. Carbon processing was intensive in the small lakes. Both CO2 emission and the Holocene C pool in sediments per square meter of the lake area were highest in the smallest lakes. How-ever, because the total area of the small lakes on the areal level is limited, the large lakes are important units in C processing in the landscape. Both CO2 and CH4 concentrations and emissions were high in eutrophic lakes. High availability of nutrients and the fresh organic matter enhance degradation in these lakes. Eutrophic lakes are often small and shallow, enabling high contact between the water column and the sediment. At the landscape level, the lakes in agricultural areas are often eutrophic due to fertile soils and fertilization of the catchments, and therefore they also showed the highest CO2 and CH4 concentrations. Export from the catchments and in-lake degradation were suggested to be equally important sources of CO2 and CH4 in fall when the lake water column was intensively mixed and the transport of sub-stances from the catchment was high due to the rainy season. In the stagnant periods, especially in the winter, in-lake degradation as a gas source was highlighted due to minimal mixing and limited transport of C from the catchment. The strong relationship between the annual CO2 level of lakes and the annual precipitation suggests that climate change can have a major impact on C cycling in the catchments. Increase in precipitation enhances DOC export from the catchments and leads to increasing greenhouse gas emissions from lakes. The total annual CO2 emission from Finnish lakes was estimated to be 1400 Gg C a-1. The total lake sediment C pool in Finland was estimated to be 0.62 Pg, giving an annual sink in Finnish lakes of 65 Gg C a-1.

Identification of a novel FGFRL1 MicroRNA target site polymorphism for bone mineral density in meta-analyses of genome-wide association studies

MicroRNAs (miRNAs) are critical post-transcriptional regulators. Based on a previous genome-wide association (GWA) scan, we conducted a polymorphism in microRNAs' Target Sites (poly-miRTS)-centric multistage meta-analysis for lumbar spine (LS)-, total hip (HIP)-, and femoral neck (FN)-bone mineral density (BMD). In stage I, 41,102 poly-miRTSs were meta-analyzed in 7 cohorts with a genome-wide significance (GWS) α=0.05/41,102=1.22×10-6. By applying α=5×10-5 (suggestive significance), 11 poly-miRTSs were selected, with FGFRL1 rs4647940 and PRR5 rs3213550 as top signals for FN-BMD (P-value=7.67×10-6 and 1.58×10-5) in gender-combined sample. In stage II in silico replication (two cohorts), FGFRL1 rs4647940 was the only signal marginally replicated for FN-BMD (P-value=5.08×10-3) at α=0.10/11=9.09×10-3. PRR5 rs3213550 was also selected based on biological significance. In stage III de novo genotyping replication (two cohorts), FGFRL1 rs4647940 was the only signal significantly replicated for FN-BMD (P-value=7.55×10-6) at α=0.05/2=0.025 in gender-combined sample. Aggregating three stages, FGFRL1 rs4647940 was the single stage I-discovered and stages II- and III-replicated signal attaining GWS for FN-BMD (P-value=8.87×10-12). Dual-luciferase reporter assays demonstrated that FGFRL1 3' untranslated region harboring rs4647940 appears to be hsa-miR-140-5p's target site. In a zebrafish microinjection experiment, dre-miR-140-5p is shown to exert a dramatic impact on craniofacial skeleton formation. Taken together, we provided functional evidence for a novel FGFRL1 poly-miRTS rs4647940 in a previously known 4p16.3 locus, and experimental and clinical genetics studies have shown both FGFRL1 and hsa-miR-140-5p are important for bone formation. © The Author 2015. Published by Oxford University Press. All rights reserved.

A multi-centre open-label randomised non-inferiority trial comparing watchful waiting to antibiotic treatment for acute otitis media without perforation in low-risk urban Aboriginal and Torres Strait Islander children (the WATCH trial): study protocol for a randomised controlled trial

Background Treatment guidelines recommend watchful waiting for children older than 2 years with acute otitis media (AOM) without perforation, unless they are at high risk of complications. The high prevalence of chronic suppurative otitis media (CSOM) in remote Aboriginal and Torres Strait Islander communities leads these children to be classified as high risk. Urban Aboriginal and Torres Strait Islander children are at lower risk of complications, but evidence to support the subsequent recommendation for watchful waiting in this population is lacking. Methods/Design This non-inferiority multi-centre randomised controlled trial will determine whether watchful waiting is non-inferior to immediate antibiotics for urban Aboriginal and Torres Strait Islander children with AOM without perforation. Children aged 2 − 16 years with AOM who are considered at low risk for complications will be recruited from six participating urban primary health care services across Australia. We will obtain informed consent from each participant or their guardian. The primary outcome is clinical resolution on day 7 (no pain, no fever of at least 38 °C, no bulging eardrum and no complications of AOM such as perforation or mastoiditis) as assessed by general practitioners or nurse practitioners. Participants and outcome assessors will not be blinded to treatment. With a sample size of 198 children in each arm, we have 80 % power to detect a non-inferiority margin of up to 10 % at a significance level of 5 %, assuming clinical improvement of at least 80 % in both groups. Allowing for a 20 % dropout rate, we aim to recruit 495 children. We will analyse both by intention-to-treat and per protocol. We will assess the cost- effectiveness of watchful waiting compared to immediate antibiotic prescription. We will also report on the implementation of the trial from the perspectives of parents/carers, health professionals and researchers. Discussion The trial will provide evidence for the safety and effectiveness of watchful waiting for the management of AOM in Aboriginal and Torres Strait Islander children living in urban settings who are considered to be at low risk of complications.

Structure of Mycobacterium tuberculosis RuvA, a protein involved in recombination

The process of recombinational repair is crucial for maintaining genomic integrity and generating biological diversity. In association with RuvB and RuvC, RuvA plays a central role in processing and resolving Holliday junctions, which are a critical intermediate in homologous recombination. Here, the cloning, purification and structure determination of the RuvA protein from Mycobacterium tuberculosis (MtRuvA) are reported. Analysis of the structure and comparison with other known RuvA proteins reveal an octameric state with conserved subunit-subunit interaction surfaces, indicating the requirement of octamer formation for biological activity. A detailed analysis of plasticity in the RuvA molecules has led to insights into the invariant and variable regions, thus providing a framework for understanding regional flexibility in various aspects of RuvA function.

Changing trends in counselling: A counselling psychologist's personal journey

The paper follows the development of "counselling" from the talking cures of ancient times through Chaucer's tales to the recent history of therapies in the Western world. The roles played by various leaders in the field is explored. Finally the therapies in vogue more recent decades are introduced.

Identification of loci for migraine with aura

Common migraine, i.e. migraine with (MA) or without aura (MO), is a chronic neurological disorder affecting about 10% of the Caucasian population. In MA, migraine headache is preceded by visual, sensoric and/or dysphasic reversible aura symptoms. Twin and family studies have suggested a multifactorial mode of inheritance for common migraine, and a stronger genetic component for MA than for MO. Since there is no biological or genetic marker to identify common migraine, aura symptoms provide a distinctive character to identify those suspected of suffering from migraine. The aim of this study was to identify MA susceptibility loci in well-phenotyped migraine samples with familial predisposition using different gene mapping methods. Genes coding for endothelin1 and its receptors EDNRA and ENDRB are potential candidate genes for cortical spreading depression (CSD), which is considered to be the underlying mechanism of migraine aura. The role of these genes in MA was studied in 850 Finnish migraine cases and 890 control individuals. Rare homozygous EDNRA SNPs showed nominal association with MA and with the age of onset trait (20 years). This result was also detected in the pooled analysis on 648 German MA cases and 651 control individuals when the test was adjusted for gender and sample origin. Evaluation of SNP genotyping reactions with two different DNA polymerase enzymes ensured that the genotype quality was high, and thus the discovered associations are considered reliable. The role of the 19p13 region was studied in a linkage analysis of 72 Finnish MA families. This region contains two migraine-associated genes: CACNA1A, which is associated with a predisposition to a rare Mendelian form of MA, familial hemiplegic migraine (FHM), and the insulin receptor gene (INSR) that is associated with common migraine. No evidence of linkage between the 19p13 and MA was detected. A novel visual aura locus was mapped to chromosome 9q21-q22 with significant evidence of linkage using a genome-wide linkage approach in 36 Finnish MA families. Five additional, potential loci were also detected. The 9q21-q22 region has previously been linked to occipitotemporal lobe epilepsy and MA, both of which involve prominent visual symptoms. Our result further supports a shared background for these episodic disorders.

Sinteractive anodic powders improve densification and electrochemical properties of BaZr0.8Y0.2O3-δ electrolyte films for anode-supported solid oxide fuel cells

The difficult sintering of BaZr0.8Y0.2O 3-δ (BZY20) powders makes the fabrication of anode-supported BZY20 electrolyte films complex. Dense BZY20 membranes were successfully fabricated on anode substrates made of sinteractive NiO-BZY20 powders, prepared by a combustion method. With respect to traditional anode substrates made of powders prepared by mechanical mixing, the anode substrates made of the wet-chemically synthesized composite NiO-BZY20 powders significantly promoted the densification of BZY20 membranes: dense BZY20 films were obtained after co-pressing and co-firing at 1300 °C, a much lower temperature than those usually needed for densifying BZY20 membranes. Improved electrochemical performance was also observed: the supported BZY20 films maintained a high proton conductivity, up to 5.4 × 10-3 S cm-1 at 700 °C. Moreover, an anode-supported fuel cell with a 30 m thick BZY20 electrolyte film fabricated at 1400 °C on the anode made of the wet-chemically synthesized NiO-BZY20 powder showed a peak power density of 172 mW cm-2 at 700 °C, using La0.6Sr0.4Co 0.2Fe0.8O3-δ-BaZr0.7Y 0.2Pr0.1O3-δ as the cathode material, with a remarkable performance for proton-conducting solid oxide fuel cell (SOFC) applications.

Hot corrosion of γ-Y2Si2O7 in strongly basic Na2CO3 molten salt environment

γ-Y2Si2O7 is a promising candidate both for high temperature structural applications and as thermal barrier coatings due to its unique combination of properties, such as high melting point, good machinability, high thermal stability, low linear thermal expansion coefficient (3.9 × 10-6 K-1, 25-1400 °C) and low thermal conductivity (<3 W/m K above 300 °C). In this work, the hot corrosion behavior of γ-Y2Si2O7 in strongly basic Na2CO3 molten salt at 850-1000 °C for 20 h in flowing air was investigated. In the employed conditions, multi-layer corrosion scales with total thickness less than 90 μm were formed. At 850-900 °C, the outmost layer of the scale was composed of the reprecipitation of Y2O3, the bottom of a Si-rich Na2O·xSiO2 (x > 3.65) melt layer, and the middle of a NaYSiO4 layer. At 1000 °C, the corrosion products turned out to be a mixture of NaY9Si6O26 and Si-rich Na2O·xSiO2 (x > 3.65). In all cases, a thin layer of protective SiO2 formed under the Na2O·xSiO2 melt and protected the bulk material from further corrosion.

Low-temperature synthesis and sintering of γ-Y2Si2O7

In this article, a novel pressureless solid-liquid reaction method is presented for preparation of yttrium disilicate (γ-Y2Si2O7). Single-phase γ-Y2Si2O7 powder was synthesized by calcination of SiO2 and Y2O3 powders with the addition of LiYO2 at 1400 °C for 4 h. The addition of LiYO2 significantly decreased the synthesis temperature, shortened the calcination time, and enhanced the stability of γ-Y2Si2O7. The sintering of these powders in air and O2 was studied by means of thermal mechanical analyzer. It is shown that the γ-Y2Si2O7 sintered in oxygen had a faster densification rate and a higher density than that sintered in air. Furthermore, single-phase γ-Y2Si2O7 with a density of 4.0 g/cm3 (99% of the theoretical density) was obtained by pressureless sintering at 1400 °C for 2 h in oxygen. Microstructures of the sintered samples are studied by scanning electron microscope.

The effect of high versus low intensity heat acclimation on performance and neuromuscular responses

This study examined the effect of exercise intensity and duration during 5-day heat acclimation (HA) on cycling performance and neuromuscular responses. 20 recreationally trained males completed a ‘baseline’ trial followed by 5 consecutive days HA, and a ‘post-acclimation’ trial. Baseline and post-acclimation trials consisted of maximal voluntary contractions (MVC), a single and repeated countermovement jump protocol, 20 km cycling time trial(TT) and 5x6 s maximal sprints (SPR). Cycling trials were undertaken in 33.0 ± 0.8 °C and 60 ± 3% relative humidity.Core(Tcore), and skin temperatures (Tskin), heart rate (HR), rating of perceived exertion (RPE) and thermal sensation were recorded throughout cycling trials. Participants were assigned to either 30 min high-intensity (30HI) or 90 min low-intensity (90LI) cohorts for HA, conducted in environmental conditions of 32.0 ± 1.6 °C. Percentage change time to complete the 20 km TT for the 90LI cohort was significantly improved post-acclimation(-5.9 ± 7.0%; P=0.04) compared to the 30HI cohort (-0.18 ± 3.9%; P<0.05). The 30HI cohort showed greatest improvements in power output (PO) during post-acclimation SPR1 and 2 compared to 90LI (546 ± 128 W and 517 ± 87 W,respectively; P<0.02). No differences were evident for MVC within 30HI cohort, however, a reduced performance indicated by % change within the 90LI (P=0.04). Compared to baseline, mean Tcore was reduced post-acclimation within the 30HI cohort (P=0.05) while mean Tcore and HR were significantly reduced within the 90LI cohort (P=0.01 and 0.04, respectively). Greater physiological adaptations and performance improvements were noted within the 90LI cohort compared to the 30HI. However, 30HI did provide some benefit to anaerobic performance including sprint PO and MVC. These findings suggest specifying training duration and intensity during heat acclimation may be useful for specific post-acclimation performance.