Molecular hydrogen (H2) mixing ratio and stable isotopic composition (dD) at the Cabauw tall tower in the Netherlands (2008-2012)

Measurements of the stable isotopic composition (dD(H2) or dD) of atmospheric molecular hydrogen (H2) are a useful addition to mixing ratio (X(H2)) measurements for understanding the atmospheric H2 cycle. dD datasets published so far consist mostly of observations at background locations. We complement these with observations from the Cabauw tall tower at the CESAR site, situated in a densely populated region of the Netherlands. Our measurements show a large anthropogenic influence on the local H2 cycle, with frequently occurring pollution events that are characterized by X(H2) values that reach up to 1 ppm and low dD values. An isotopic source signature analysis yields an apparent source signature below -400 per mil, which is much more D-depleted than the fossil fuel combustion source signature commonly used in H2 budget studies. Two diurnal cycles that were sampled at a suburban site near London also show a more D-depleted source signature (-340 per mil), though not as extremely depleted as at Cabauw. The source signature of the Northwest European vehicle fleet may have shifted to somewhat lower values due to changes in vehicle technology and driving conditions. Even so, the surprisingly depleted apparent source signature at Cabauw requires additional explanation; microbial H2 production seems the most likely cause. The Cabauw tower site also allowed us to sample vertical profiles. We found no decrease in (H2) at lower sampling levels (20 and 60m) with respect to higher sampling levels (120 and 200m). There was a significant shift to lower median dD values at the lower levels. This confirms the limited role of soil uptake around Cabauw, and again points to microbial H2 production during an extended growing season, as well as to possible differences in average fossil fuel combustion source signature between the different footprint areas of the sampling levels. So, although knowledge of the background cycle of H2 has improved over the last decade, surprising features come to light when a non-background location is studied, revealing remaining gaps in our understanding.

The magical transformation contest in the ancient storytelling tradition

El concurso de transformación mágica, esquema narrativo difundido en la tradición popular, se presenta en dos variantes principales: los hechiceros que compiten pueden metamorfosearse en varios seres o crear esos seres por medios mágicos. En cualquier caso el concursante ganador da a luz criaturas más fuertes que superan las de su oponente. La segunda variante fue preferida en el antiguo Cercano Oriente (Sumeria, Egipto, Israel). La primera se puede encontrar en algunos mitos griegos sobre cambiadores de forma (por ejemplo, Zeus y Némesis). El mismo esquema narrativo puede haber influido en un episodio de la Novela de Alejandro (1.36-38), en el que Darío envía regalos simbólicos a Alejandro y los dos monarcas enemigos ofrecen contrastantes explicaciones de ellos. Esta historia griega racionaliza el concurso de cuento de hadas, transfiriendo las fantásticas hazañas de creaciones milagrosas a un plano secundario pero realista de metáfora lingüística.

Employer Branding idag : Attraktivitet genom sociala medier

The use of social media has during the last couple of years increased and is now a major part of most of the organizations marketing strategies. But how does this fit with the Employer Branding strategies? And how does this affect the organizational attractiveness as an employer? These were two of the questions we wanted to examine and analyze. In order to answer these questions, we conducted interviews with six different companies divided into 3 subgroups. The intention of this was to get a wider perspective of how the implementation of social media in the Employer Branding could work. And could this change the recruitment process? What we could see afterwards is that more time is spent on taking references online through social media sites. Some say it is more honest than the traditional references that the candidate got to choose. Other conclusions that we could find was that it is important to use social media in todays market but it is crucial to use it in a proper way. Companies must form a strategy based on their Employee Value Proposition in order to reach the wanted receivers using social media. It is also important that the Employee Value Proposition is based on the companies’ corporate values.

Two years survival rate of Class II ART restorations in primary molars using two ways to avoid saliva contamination

AIM To compare the survival rates of Class II Atraumatic Restorative Treatment (ART) restorations placed in primary molars using cotton rolls or rubber dam as isolation methods. METHODS A total of 232 children, 6-7 years old, both genders, were selected having one primary molar with proximal dentine lesion. The children were randomly assigned into two groups: control group with Class II ART restoration made using cotton rolls and experimental group using rubber dam. The restorations were evaluated by eight calibrated evaluators (Kappa > 0.8) after 6, 12, 18 and 24 months. RESULTS A total of 48 (20.7%) children were considered dropout, after 24 months. The cumulative survival rate after 6, 12, 18 and 24 months was 61.4%, 39.0%, 29.1% and 18.0%, respectively for the control group, and 64.1%, 55.1%, 40.1% and 32.1%, respectively for the rubber dam group. The log rank test for censored data showed no statistical significant difference between the groups (P = 0.07). The univariate Cox Regression showed no statistical significant difference after adjusting for independent variables (P > 0.05). CONCLUSION Both groups had similar survival rates, and after 2 years, the use of rubber dam does not increase the success of Class II ART restorations significantly.

Shear bond strengths of three glass ionomer cements to enamel and dentine

OBJECTIVES The shear bond strength of three glass ionomer cements (GIC) to enamel and dentine was evaluated. STUDY DESIGN Sound permanent human molars (n=12) were grinded perpendicular to their axial axes, exposing smooth, flat enamel and dentine surfaces. The teeth were embedded in resin and conditioned with polyacrylic acid (25%; 10s). Twenty four specimens of each GIC: Fuji IX (FJ-GC), Ketac Molar Easymix (KM-3M ESPE) and Maxxion (MX-FGM) were prepared according to the Atraumatic Restorative Treatment (ART) (12 enamel and 12 dentine), in a bonding area of 4.91 mm² and immersed in water (37°C, 24h). The shear bond strength was tested in a universal testing machine. Non-parametric statistical tests (Friedman and post-hoc Wilcoxon Signed Ranks) were carried out (p=0.05). RESULTS The mean (±sd) of shear bond strength (MPa), on enamel and dentine, were: KM (6.4±1.4 and 7.6±1.5), FJ (5.9±1.5 and 6.0±1.9) and MX (4.2±1.5 and 4.9±1.5), respectively. There was a statistically significant difference between the GICs in both groups: enamel (p=0.004) and dentine (p=0.002). The lowest shear bond value for enamel was with MX and the highest for dentine was KM (p<0.05). CONCLUSION It is concluded that KM has the best adhesion to both enamel and dentine, followed by FJ and MX.

Digitala primärkällor i historieundervisningen: En utmaning för elevers historiska tänkande och historiska empati

In this study, 110 Swedish upper secondary students use a historical database designed for research. We analyze how they perceive the use of this digital tool in teaching and if they are able to use historical thinking and historical empathy in their historical writing and presentations. Using case-study methodology including questionnaires, observations, interviews and text analysis we find this to be a complex task for students. Our results highlight technological problems and problems in contextualizing historical evidence. However, students show interest in using primary sources and ability to use historical thinking and historical empathy, especially older students in more advanced courses when they have time to reflect upon the historical material.

"Jag är inte en så'n som är bra på matte" : Hur faktorer i skolan kan påverka elevers matematiska subjektskapande

Matematik som ämne har under lång tid uppfattats som maskulint kodat. Sådana genusstyrda föreställningar kan anses leva kvar än idag, då det efter analys av statistik framgår att de personer som väljer yrken och utbildningar som är matematikintensiva till stor del är män. I skolans styrdokument står det att att elevers könstillhörighet inte ska avgöra vilka studier och arbeten de väljer i framtiden. Syftet med denna studie är därför att undersöka hur flickors och pojkars matematiska subjektskapande påverkas av faktorer i skolan. Genom att utgå från begrepp som kan ses som centrala i den poststrukturalistiska feministiska teoribildningen möjliggörs denna komparativa litteraturstudie.   De forskningspublikationer som har jämförts och analyserats har resulterat i en sammanställning av olika faktorer som påverkar elevers matematiska subjektskapande. De återkommande faktorer som vi har valt att behandla i denna studie är hur läraren påverkar elevers matematiska subjektskapande, hur klassrumsdiskursen påverkar elevers matematiska subjektivitet samt hur subjektskapandet påverkar matematiska strategier. Resultatet visar att det inte går att urskilja tydliga skillnader mellan flickors och pojkars matematiska prestationer i förskolan och början av årskurs 1, utan dessa ökar under de första skolåren. Av de publikationer vi har analyserat framkommer att subjektskapandet påverkas av faktorer i skolan och att lärares genusstyrda föreställningar har betydelse för subjektskapandet.    Genom att se på människan som ett lärandesubjekt, som hela tiden skapas och skapar sig själv i förhållande till sammanhanget, möjliggörs föreställningen om att även det matematiska subjektskapandet kan ses som föränderligt. Med detta synsätt är subjektet inte matematiskt, utan detta är istället något som subjektet kan bli. Att som lärare ha detta förhållningssätt är av stor relevans för professionen, då det är en förutsättning för att alla elever ska ha möjlighet att utvecklas. 

Punahilkalla on ollut eväät kunnossa – Antero Mertarannan jääkiekkoselostusten intertekstuaaliset kielen piirteet

Tutkin urheilutoimittaja Antero Mertarannan jääkiekkoselostusten kielen piirteitä. Litteroimani aineisto on MM-kisoista keväältä 2011, ja analysoin niitä kielen piirteitä, joita voi toistuvuuden perusteella pitää Mertarannalle ominaisina. Tutkimustani läpäisevä käsite on intertekstuaalisuus: Mistä se selostukseen kirvoittuu? Miten se vaikuttaa selostukseen? Pureudun tarkasti myös mielikuviin, joita Mertaranta luo sekä joukkueista että pelaajista. Hyödynnän analyysissani Norman Faircloughin (1992) perustavan intertekstuaalisuuden ja avoimen intertekstuaalisuuden käsitteitä. Mertarannalla intertekstuaalisuuden ensimmäinen virike tulee pelitilanteesta, joka käynnistää assosiaatioketjun. Assosiaatiot kumpuavat herkästi pelaajan ominaispiirteistä ja joukkueen edustamasta maasta. Suomalaisten kuvailussa on useimmiten alluusio suomalaiseen musiikkiin. Mertarannan selostuksessa on kertomuksen, kansallisromanttisen kuvailun ja show-juonnon elementtejä, ja lisäksi hän muuntelee sananlaskuja ja idiomeja pelitilanteisiin sopiviksi. Mertaranta myös imitoi pelaajia: Vastustajien referointi alkaa lähes aina kysymyksellä, jolloin vastustaja näyttäytyy hölmistyneessä valossa. Suomalaisten referoinnit taas hohkaavat itsevarmuutta. Intertekstuaalisuus osoittautuu Mertarannan huumorin perustaksi.

On estimating attenuation from the amplitude of the spectrally whitened ambient seismic field

International audience

Novae species cycadearum Africae Australis /

Reprinted from Tijdschrift voor natuurlijke geschiedenis en physiologie, v. 4.

A novel antigen capture ELISA for the specific detection of IgG antibodies to elephant endotheliotropic herpes virus

BACKGROUND Elephants are classified as critically endangered animals by the International Union for Conservation of Species (IUCN). Elephant endotheliotropic herpesvirus (EEHV) poses a large threat to breeding programs of captive Asian elephants by causing fatal haemorrhagic disease. EEHV infection is detected by PCR in samples from both clinically ill and asymptomatic elephants with an active infection, whereas latent carriers can be distinguished exclusively via serological assays. To date, identification of latent carriers has been challenging, since there are no serological assays capable of detecting seropositive elephants. RESULTS Here we describe a novel ELISA that specifically detects EEHV antibodies circulating in Asian elephant plasma/serum. Approximately 80 % of PCR positive elephants display EEHV-specific antibodies. Monitoring three Asian elephant herds from European zoos revealed that the serostatus of elephants within a herd varied from non-detectable to high titers. The antibody titers showed typical herpes-like rise-and-fall patterns in time which occur in all seropositive animals in the herd more or less simultaneously. CONCLUSIONS This study shows that the developed ELISA is suitable to detect antibodies specific to EEHV. It allows study of EEHV seroprevalence in Asian elephants. Results confirm that EEHV prevalence among Asian elephants (whether captive-born or wild-caught) is high.

The optical design of a far infrared imaging FTS for SPICA

This paper describes the optical design of the far infrared imaging spectrometer for the JAXA's SPICA mission. The SAFARI instrument, is a cryogenic imaging Fourier transform spectrometer (iFTS), designed to perform backgroundlimited spectroscopic and photometric imaging in the band 34-210 μm. The all-reflective optical system is highly modular and consists of three main modules; input optics module, interferometer module (FTS) and camera bay optics. A special study has been dedicated to the spectroscopic performance of the instrument, in which the spectral response and interference of the instrument have been modeled, as the FTS mechanism scans over the total desired OPD range.

SAFARI optical system architecture and design concept

SpicA FAR infrared Instrument, SAFARI, is one of the instruments planned for the SPICA mission. The SPICA mission is the next great leap forward in space-based far-infrared astronomy and will study the evolution of galaxies, stars and planetary systems. SPICA will utilize a deeply cooled 2.5m-class telescope, provided by European industry, to realize zodiacal background limited performance, and high spatial resolution. The instrument SAFARI is a cryogenic grating-based point source spectrometer working in the wavelength domain 34 to 230 μm, providing spectral resolving power from 300 to at least 2000. The instrument shall provide low and high resolution spectroscopy in four spectral bands. Low Resolution mode is the native instrument mode, while the high Resolution mode is achieved by means of a Martin-Pupplet interferometer. The optical system is all-reflective and consists of three main modules; an input optics module, followed by the Band and Mode Distributing Optics and the grating Modules. The instrument utilizes Nyquist sampled filled linear arrays of very sensitive TES detectors. The work presented in this paper describes the optical design architecture and design concept compatible with the current instrument performance and volume design drivers.

The hierarchic structure of fears: A cross-cultural replication with the fear survey schedule in a portuguese sample

A confirmatory attempt is made to assess the validity of a hierarchic structural model of fears. Using a sample comprising 1,980 adult volunteers in Portugal, the present study set out to delineate the multidimensional structure and hierarchic organization of a large set of feared stimuli by contrasting a higher-order model comprising general fear at the highest level against a first-order model and a unitary fear model. Following a refinement of the original model, support was found for a five-factor model on a first-order level, namely (1) Social fears, (2) Agoraphobic fears, (3) Fears of bodily injury, death and illness, (4) Fears of display to aggressive scenes, and (5) Harmless animals fears. These factors in turn loaded on a General fear factor at the second-order level. However, the firstorder model was as parsimonious as a hierarchic higher-order model. The hierarchic model supports a quantitative hierarchic approach which decomposes fear disorders into agoraphobic, social, and specific (animal and bloodinjury) fears.