Työhyvinvoinnin kannalta merkitykselliset tekijät peruskoulun työyhteisössä:vastavalmistuneiden opettajien näkökulmia

Tiivistelmä. Opettajien työhyvinvointi on jo pitkään ollut pinnalla niin julkisessa keskustelussa kuin alaa koskevassa tutkimuksessa. Viitteet kasvatusalan heikentyvistä työoloista herättävät huolta opettajien työssäjaksamisesta sekä ammatin houkuttelevuudesta. Koska ammattitaitoiset ja työhönsä sitoutuneet opettajat ovat laadukkaan ja yhdenvertaisen koulutuksen tärkeimpiä resursseja, on työnteon edellytysten turvaaminen ja kehittäminen välttämätöntä. Pro gradu -tutkielmassamme tarkastelemme, mitkä tekijät ovat vastavalmistuneiden opettajien mukaan merkityksellisiä työhyvinvoinnin kannalta, sekä työyhteisön ja sen yhteisöllisyyden merkityksellisyyttä suhteessa työhyvinvointiin. Tutkimuksen kohteeksi on valittu työuransa alussa olevat opettajat, sillä vastavalmistuneelle niin työhön liittyvät tekijät kuin uutena jäsenenä työyhteisö ja sen yhteisöllisyys näyttäytyvät ainutlaatuiselta näkökantilta. Tutkimuksen tarkoituksena on kasvatusalan työhyvinvointiin liittyvien merkityksellisien kokemuksien ja näkemyksien avulla myös tunnistaa mahdollisia työhön liitännäisiä voimavaroja esimerkiksi työyhteisöstä. Tutkimus on toteutettu kvalitatiivisesti ja aineistolähtöistä sisällönanalyysia hyödyntäen. Aineistonkeruu toteutettiin haastattelemalla joko kasvokkain tai etäyhteyksiä hyödyntäen. Tutkimukseen osallistui seitsemän vastavalmistunutta opettajaa, jotka työskentelevät peruskoulussa erilaisissa opetustehtävissä. Vastavalmistuneiden opettajien mukaan työhyvinvoinnin kannalta merkitykselliset tekijät liittyivät niin henkilökohtaiseen työskentelyyn, työntekoa ohjaaviin rakenteiseen ja olosuhteisiin kuin työyhteisöön ja sen yhteisöllisyyteen. Merkityksellisien tekijöiden välillä ilmeni paljon liitännäisyyksiä ja opettajat käsittivät työhyvinvointinsa hyvin moninaisena. Tuloksissa korostui työhyvinvoinnin henkilökohtainen ja tilannesidonnainen luonne, sillä haastatteluissa nousi erityisen merkitykselliseksi haastateltavien yksilöllisistä työnteon konteksteista kumpuavat tekijät

Primer genoma mitocondrial en restos humanos de la Costa de Santa Cruz, Argentina

En este trabajo se presenta la secuencia completa de ADN mitocondrial, obtenida a partir de restos óseos de un hombre adulto, hallado en el sitio Cañadón Misioneros (provincia de Santa Cruz, Argentina), con una antigüedad de 70 ± 30 años antes del presente. La secuencia corresponde al haplogrupo (hg) D4h3a5, nativo de América y exclusivo del sur de Patagonia, donde ha sido descripto tanto en muestras antiguas como actuales. Esta secuencia constituye el primer dato de ADN mitocondrial en la costa atlántica de Patagonia con la resolución suficiente para definir a nivel de subhaplogrupo. Se discuten las implicancias en cuanto a los vínculos biológicos de las poblaciones que habitaron esa porción del espacio patagónico en el marco de la información genética y arqueológica disponible.We describe the complete mitochondrial genome sequence of an adult male skeleton, discovered at Cañadón Misioneros (Santa Cruz Province, Argentina), and dated 70 ± 30 years before present. The DNA sequence corresponded to haplogroup D4h3a5, native to the Americas and exclusive to the south of Patagonia, where it has been observed both in ancient and present-day individuals. This is the first mitochondrial DNA data of the Atlantic coast of Patagonia of sufficient resolution to permit classification at the subhaplogroup level. The implications for the genetic affinities of populations of this region of Patagonia will be discussed in the context of available genetic and archaeological information

VIBES: VIsual Binary Exoplanet survey with SPHERE Upper limits on wide S-planet and S-BD frequencies, triple system discovery, and astrometric confirmation of 20 stellar binaries and three triple systems

Recent surveys indicate that planets in binary systems are more abundant than previously thought, which is in agreement with theoretical work on disc dynamics and planet formation in binaries. In order to measure the abundance and physical characteristics of wide-orbit giant exoplanets in binary systems, we have designed the 'VIsual Binary Exoplanet survey with Sphere' (VIBES) to search for planets in visual binaries. It uses the SPHERE instrument at VLT to search for planets in 23 visual binary and four visual triple systems with ages of <145 Myr and distances of <150 pc. We used the IRDIS dual-band imager on SPHERE to acquire high-contrast images of the sample targets. For each binary, the two components were observed at the same time with a coronagraph masking only the primary star. For the triple star, the tight components were treated as a single star for data reduction. This enabled us to effectively search for companions around 50 individual stars in binaries and four binaries in triples. We derived upper limits of $<$13.7\% for the frequency of sub-stellar companions around primaries in visual binaries, $<$26.5\% for the fraction of sub-stellar companions around secondaries in visual binaries, and an occurrence rate of $<$9.0\% for giant planets and brown dwarfs around either component of visual binaries. We have combined our observations with literature measurements to astrometrically confirm, for the first time, that 20 binaries and two triple systems, which were previously known, are indeed physically bound. Finally, we discovered a third component of the binary HD~121336. The upper limits we derived are compatible with planet formation through the core accretion and the gravitational instability processes in binaries. These limits are also in line with limits found for single star and circumbinary planet search surveys.Comment: Accepted for publication in Astronomy & Astrophysics on 18.09.2020 21 pages, 11 figure

Predicting protein decomposition: the case of aspartic-acid racemization kinetics

The increase in proportion of the non-biological (D-) isomer of aspartic acid (Asp) relative to the L- isomer has been widely used in archaeology and geochemistry as a tool for dating. The method has proved controversial, particularly when used for bones. The non-linear kinetics of Asp racemization have prompted a number of suggestions as to the underlying mechanism(s) and have led to the use of mathe- matical transformations which linearize the increase in D-Asp with respect to time. Using one example, a suggestion that the initial rapid phase of Asp racemization is due to a contribution from asparagine (Asn), we demonstrate how a simple model of the degradation and racemization of Asn can be used to predict the observed kinetics. A more complex model of peptide bound Asx (Asn+Asp) racemization, which occurs via the formation of a cyclic succinimide (Asu), can be used to correctly predict Asx racemi- zation kinetics in proteins at high temperatures (95-140 °C). The model fails to predict racemization kinetics in dentine collagen at 37 °C. The reason for this is that Asu formation is highly conformation dependent and is predicted to occur extremely slowly in triple helical collagen. As conformation strongly in£uences the rate of Asu formation and hence Asx racemization, the use of extrapolation from high temperatures to estimate racemization kinetics of Asx in proteins below their denaturation temperature is called into question. In the case of archaeological bone, we argue that the D:L ratio of Asx re£ects the proportion of non- helical to helical collagen, overlain by the e¡ects of leaching of more soluble (and conformationally unconstrained) peptides. Thus, racemization kinetics in bone are potentially unpredictable, and the proposed use of Asx racemization to estimate the extent of DNA depurination in archaeological bones is challenged

The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits: II- Survey description, results and performances

In anticipation of the VLT/SPHERE planet imager guaranteed time programs, we have conducted a preparatory survey of 86 stars between 2009 and 2013 in order to identify new faint comoving companions to ultimately carry out a comprehensive analysis of the occurence of giant planets and brown dwarf companions at wide (10-2000 AU) orbits around young, solar-type stars. We used NaCo at VLT to explore the occurrence rate of giant planets and brown dwarfs between typically 0.1 and 8''. Diffraction-limited observations in H-band combined with angular differential imaging enabled us to reach primary star-companion brightness ratios as small as 10-6 at 1.5''. 12 systems were resolved as new binaries, including the discovery of a new white dwarf companion to the star HD8049. Around 34 stars, at least one companion candidate was detected in the observed field of view. More than 400 faint sources were detected, 90% of them in 4 crowded fields. With the exception of HD8049B, we did not identify any new comoving companions. The survey also led to spatially resolved images of the thin debris disk around HD\,61005 that have been published earlier. Finally, considering the survey detection limits, we derive a preliminary upper limit on the frequency of giant planets for semi-major axes of [10,2000] AU: typically less than 15% between 100 and 500 AU, and less than 10% between 50 and 500 AU for exoplanets more massive than 5 MJup and 10 MJup respectively, considering a uniform input distribution and with a confidence level of 95%.Comment: 19 pages, 8 figures, 12 Tables, accepted to A&

The VLT/NaCo Large program to probe the occurrence of exoplanets and brown dwarfs in wide orbits: I- Sample definition and characterization

Young, nearby stars are ideal targets to search for planets using the direct imaging technique. The determination of stellar parameters is crucial for the interpretation of imaging survey results particularly since the luminosity of substellar objects has a strong dependence on system age. We have conducted a large program with NaCo at the VLT in order to search for planets and brown dwarfs in wide orbits around 86 stars. A large fraction of the targets observed with NaCo were poorly investigated in the literature. We performed a study to characterize the fundamental properties (age, distance, mass) of the stars in our sample. To improve target age determinations, we compiled and analyzed a complete set of age diagnostics. We measured spectroscopic parameters and age diagnostics using dedicated observations acquired with FEROS and CORALIE spectrographs at La Silla Observatory. We also made extensive use of archival spectroscopic data and results available in the literature. Additionally, we exploited photometric time-series, available in ASAS and Super-WASP archives, to derive rotation period for a large fraction of our program stars. We provided updated characterization of all the targets observed in the VLT NaCo Large program, a survey designed to probe the occurrence of exoplanets and brown dwarfs in wide orbits. The median distance and age of our program stars are 64 pc and 100 Myr, respectively. Nearly all the stars have masses between 0.70 and 1.50sun, with a median value of 1.01 Msun. The typical metallicity is close to solar, with a dispersion that is smaller than that of samples usually observed in radial velocity surveys. Several stars are confirmed or proposed here to be members of nearby young moving groups. Eight spectroscopic binaries are identified.Comment: 64 pages with Appendix, 15 figures, accepted to A&