Remote work and social jetlag: Systematic review and empirical investigation of the healthy adult working force in Finland

This study aimed to investigate the association between remote work and sleep parameters (social jetlag, self-reported sleep quality, and sleep duration) among healthy adult working force in Finland. The hypothesis was that remote work would reduce social obligations, which are the main cause of social jetlag, and therefore associate with smaller amount of social jetlag and with other sleep parameters, especially among evening chronotypes. This hypothesis was based on a systematic review of effects of COVID-19 restrictions on social jetlag, which was conducted. This thesis utilizes data from a survey conducted in Climate Nudge Project and included 830 participants who worked or studied full-time after excluding those with sleep, health, or work ability issues. Remote work was operationalized as work modality and as frequency of work at the workplace. Statistical analyses were conducted using t-tests for work modality and simple linear regression and general linear models to assess the association between remote work and sleep parameters after inclusion of covariates. Remote work was associated with longer sleep duration and smaller amount of social jetlag. Those with any amount of remote work (work modality) compared with full week of work at the workplace had 17 minutes longer sleep duration during weekdays and 21 minutes shorter social jetlag. Predictions from general linear model produced similar results and these associations were strongest among evening types. Overall, these findings suggest that remote work may have a beneficial impact on sleep duration and social jetlag. Future studies should examine whether remote work increases productivity, which could increase the opportunities for remote work within companies and therefore utilize the beneficial association between remote work and sleep.Tämä tutkimus tutki etätyön ja uniparametrien (sosiaalinen aikaerorasitus, itsearvioitu unen laatu ja unen kesto) välistä yhteyttä suomalaisessa terveessä aikuisväestössä. Tutkimuksen hypoteesi oli, että etätyö vähentäisi sosiaalisten velvollisuuksien määrää, jotka ovat sosiaalisen aikaerorasituksen pääaiheuttajia, mikä olisi yhteydessä alhaisempaan sosiaaliseen aikaerorasitukseen sekä muihin uniparametreihin, erityisesti iltatyypeillä. Tutkimuksen hypoteesi perustui tehtyyn systemaattiseen katsaukseen COVID-19 rajoitusten vaikutuksista sosiaaliseen aikaerorasitukseen. Tämä pro gradu -tutkielma hyödyntää kyselydataa Ilmastotuuppaus-projektista. Tutkimus sisälsi 830 vastaajaa, jotka työskentelivät tai opiskelivat täysipäiväisesti ilman unen, terveyden tai työkyvyn ongelmia Etätyö operationalisoitiin työmuotona sekä työpaikalla tehdyn työn frekvenssinä. Tilastolliset analyysit suoritettiin käyttämällä t-testejä työmuodolle sekä yksinkertaisia lineaarisia regressio- ja yleisiä lineaarisia malleja arvioimaan etätyön ja uniparametrien välistä yhteyttä kovariaattien huomioimisen jälkeen. Etätyö oli yhteydessä pidempään unen kestoon sekä vähäisempään sosiaaliseen aikaerorasitukseen. Mikä tahansa määrä etätyötä (työmuoto) verrattuna koko viikon työhön työpaikalla, oli yhteydessä 17 minuuttia pidempään unen kestoon ja 21 minuuttia lyhyempään sosiaaliseen aikaerorasitukseen. Yleisen lineaarisen mallin mallinnukset antoivat vastaavanlaiset tulokset ja nämä yhteydet olivat suurimpia iltatyypeillä. Kaikkiaan, nämä tulokset antavat viitteitä, että etätyöllä voi olla positiivisen yhteys unen kestoon ja sosiaaliseen aikaerorasitukseen. Jatkotutkimusten tulisi tutkia lisääkö etätyö työn tuottavuutta, mikä voisi olla tapa lisätä etätyön mahdollisuutta yrityksissä ja sitä kautta hyödyntää etätyön hyödyllistä vaikutusta uneen

Ikä vaikuttaa kuusen kuolleisuuteen

Ikääntyminen ja kilpailu heikentävät puiden veden ja ravinteiden saantia, joka altistaa ne kuolemiselle. Joissakin tutkimuksissa kuusen eloonjäämisen on havaittu laskevan suurissa läpimittaluokissa, mutta iän vaikutusta ei ole otettu huomioon. Tässä tutkimuksessa tarkasteltiin kuusen ikääntymisen vaikutusta eloonjäämiseen sovittamalla useita vaihtoehtoisia eloonjäämismalleja

Polarised Multiangular Reflectance Measurements Using the Finnish Geodetic Institute Field Goniospectrometer

The design, operation, and properties of the Finnish Geodetic Institute Field Goniospectrometer (FIGIFIGO) are presented. FIGIFIGO is a portable instrument for the measurement of surface Bidirectional Reflectance Factor (BRF) for samples with diameters of 10 – 50 cm. A set of polarising optics enable the measurement of linearly polarised BRF over the full solar spectrum (350 – 2,500 nm). FIGIFIGO is designed mainly for field operation using sunlight, but operation in a laboratory environment is also possible. The acquired BRF have an accuracy of 1 – 5% depending on wavelength, sample properties, and measurement conditions. The angles are registered at accuracies better than 2°. During 2004 – 2008, FIGIFIGO has been used in the measurement of over 150 samples, all around northern Europe. The samples concentrate mostly on boreal forest understorey, snow, urban surfaces, and reflectance calibration surfaces

Photometric modelling for laboratory measurements of dark volcanic sand

We have performed laboratory measurements of the bidirectional reflectance factor (BRF) of a sample of dark volcanic sand. The measurements were carried out with three different treatments of the sample to produce different porosity and roughness characteristics. We model the measured BRF with a semi-numerical scattering model for particulate media, meant especially for dark planetary regoliths. We compare the BRF in two different spectral bands, 500-600 nm and 800-900 nm. The particulate medium (PM). scattering model is found to fit the measured data well, with a phase function representing the differences between the spectral bands. The interpretation of the physical parameters of the PM model is qualitatively sound, but remains somewhat uncertain due in part to the difficulty of characterizing the measured sample. (C) 2016 Elsevier Ltd. All rights reserved.Peer reviewe

Multiple Scattering in Discrete Random Media Using First-Order Incoherent Interactions

Peer reviewe

Models for integrating and identifying the effect of senescence on individual tree survival probability for Norway spruce

Ageing and competition reduce trees’ ability to capture resources, which predisposes them to death. In this study, the effect of senescence on the survival probability of Norway spruce (Picea abies (L.) Karst.) was analysed by fitting alternative survival probability models. Different model formulations were compared in the dataset, which comprised managed and unmanaged plots in long-term forest experiments in Finland and Norway, as well as old-growth stands in Finland. Stand total age ranged from 19 to 290 years. Two models were formulated without an age variable, such that the negative coefficient for the squared stem diameter described a decreasing survival probability for the largest trees. One of the models included stand age as a separate independent variable, and three models included an interaction term between stem diameter and stand age. According to the model including stand age and its interaction with stem diameter, the survival probability curves could intersect each other in stands with a similar structure but a different mean age. Models that did not include stand age underestimated the survival rate of the largest trees in the managed stands and overestimated their survival rate in the old-growth stands. Models that included stand age produced more plausible predictions, especially for the largest trees. The results supported the hypothesis that the stand age and senescence of trees decreases the survival probability of trees, and that the ageing effect improves survival probability models for Norway spruce

Spectral Reflectance Processing via Local Wavelength-Direction Correlations

The spectral bidirectional reflectance distribution function (BRDF) maps incident radiation of a surface to its outgoing counterpart at different wavelengths. This function plays a fundamental role in characterizing the various types of earth surfaces. Due to its high dimensionality, the measurements, analysis, and simulation of spectral BRDF are challenging. In this letter, we introduce a new method for processing spectral reflectance using the so-called data-adjacency, i.e., the correlation between adjacent wavelengths and viewing directions. The results show that the benefits of efficient representation, noise reduction, and analysis capability can all be integrated to the data.Peer reviewe

Light scattering from volcanic-sand particles in deposited and aerosol form

The light-scattering properties of volcanic sand collected in Iceland are studied here to characterize the sand particles and develop a reference for future remote-sensing observations. While such sand is common in Iceland, the smaller-size fraction can be readily transported by winds and found in the atmosphere at distant locations. The sand appears dark when deposited on a surface due to the high optical absorption of the material. Therefore, atmospheric regions containing such particles during a dust storm may absorb sunlight considerably, causing redistribution of solar energy. Here, we measure the angular scattered-light intensity and degree of linear polarization from the sand. This is done with two experimental apparatuses, the Cosmic Dust Laboratory (CoDuLab) at the Institute de Astrofísica de Andalucía (IAA) and the goniospectropolarimeter (FIGIFIGO) at the Finnish Geospatial Research Institute (FGI). Two scattering-scenarios of practical interest for remote-sensing applications are considered: (1) single sand-particles suspended in aerosol as an optically thin cloud, and (2) the same particles deposited on a substrate. We also model the measurements with the discrete dipole approximation to estimate the complex-valued refractive index m, where we find that m ≈ 1.6 + 0.01i at λ = 647 nm. Lastly, we present a comparative analysis of the polarimetric response of the sand particles with that reported in the literature for carbon-soot, another highly absorbing atmospheric contaminant.Peer reviewe

Elvytys : KÄYPÄ HOITO -SUOSITUS (Päivitystiivistelmä)

Käypä hoito -suositus. Päivitystiivistelmä. English abstrac

Networked web-cameras monitor congruent seasonal development of birches with phenological field observations

Ecosystems' potential to provide services, e.g. to sequester carbon, is largely driven by the phonological cycle of vegetation. Timing of phenological events is required for understanding and predicting the influence of climate change on ecosystems and to support analyses of ecosystem functioning. Analyses of conventional camera time series mounted near vegetation has been suggested as a means of monitoring phenological events and supporting wider monitoring of phenological cycle of biomes that is frequently done with satellite earth observation (EO). Especially in the boreal biome, sparsely scattered deciduous trees amongst conifer-dominant forests pose a problem for EO techniques as species phenological signal mix, and render EO data difficult to interpret. Therefore, deriving phonological information from on the ground measurements would provide valuable reference data for earth observed phonology products in a larger scale. Keeping this in mind, we established a network of digital cameras for automated monitoring of phenological activity of vegetation in the boreal ecosystems of Finland. Cameras were mounted at 14 sites, each site having 1-3 cameras. In this study, we used data from 12 sites to investigate how well networked cameras can detect the phenological development of birches (Betula spp.) along a latitudinal gradient. Birches typically appear in small quantities within the dominant species. We tested whether the small, scattered birch image elements allow a reliable extraction of colour indices and the temporal changes therein. We compared automatically derived phenological dates from these birch image elements both to visually determined dates from the same image time series and to independent observations recorded in the phenological monitoring network covering the same region, Automatically extracted season start dates, which were based on the change of green colour fraction in spring, corresponded well with the visually interpreted start of the season, and also to the budburst dates observed in the field. Red colour fraction turned out to be superior to the green colour-based indices in predicting leaf yellowing and fall. The latitudinal gradients derived using automated phenological date extraction corresponded well with the gradients estimated from the phenological field observations. We conclude that small and scattered birch image elements allow reliable extraction of key phonological dates for the season start and end of deciduous species studied here, thus providing important species-specific data for model validation and for explaining the temporal variation in EO phenology products.Peer reviewe