THE FUSION OF INDIVIDUAL TREE DETECTION AND VISUAL INTERPRETATION IN ASSESSMENT OF FOREST VARIABLES FROM LASER POINT CLOUDS

In this study we searched the obtainable accuracy of forest inventory based on the individual tree detection (ITD) by using fusion of automatic ITD (ITDauto) and visual interpretation of laser point clouds. Current ITD algorithms, mostly based on segmentation of canopy height models (CHMs), are not able to utilize the whole information included in three-dimensional point clouds. We hypothesized that visual interpretation of the point cloud could provide so-called "best case" tree detection that could be achievable automatically. We refer to this method consisting of ITDauto and visual interpretation as ITDvisual. We assessed the plot level accuracies of the ITDauto and ITDvisual in boreal managed forest conditions using 322 plots. Based on the results the accuracy of ITD can be improved with visual interpretation. Omission trees are mainly missing from both ITD-methods. ITDvisual produced more accurate estimates for all forest variables compared to ITDauto, e.g. RMSE% in volume decreased from 33.3% to 27.8% and bias% in volume from 4.1% to 2.3%. Area-based approach (ABA) is becoming more general for operational forest inventories with sparser laser data. ITDvisual would be justified if it could replace expensive field work in plot-wise measurements needed for ABA. Further research is needed in the use of ITD results as a reference for ABA

Akustisen äänenlaatuindeksin (AVQI) version 03.01 validointi suomenkielisille puhujille

The Acoustic Voice Quality Index (AVQI) is an objective tool based on six acoustic parameters.It uses sustained vowel and continuous speech in the analyses and therefore it must be validatedin different languages. In this study, the newest version of AVQI (03.01) with an extendedcontinuous speech sample and improved internal consistency was validated to Finnish-speakingpopulation. The study included 197 native Finnish-speaking voluntary participants, out ofwhich 111 were patients from a phoniatric clinic and 86 were healthy voice users. A sustainedvowel and a reading sample were recorded. Mean number of the syllables comparable to the3 second sustained vowel was calculated from the reading samples. Sixteen voice specialistsevaluated the overall voice quality of the voice samples with a four-point scale. Statistic analyseswere performed to test the diagnostic accuracy between healthy and disordered voices inFinnish-speaking population. The number of syllables, comparable to 3 seconds of sustainedvowel, was 31. The correlation between the AVQI scores and the overall voice quality wasstrong (Spearman’s rho 0.77, p= 0.01). The AVQI score 1.83 was the best to distinguish healthyand dysphonic voices. The study confirmed the AVQI03.01FIN version to be a good tool invoice disorder diagnostics in Finnish speaking population.Akustinen äänenlaatuindeksi (AVQI) on objektiivinen, kuuteen eri akustiseen muuttujaan perustuva äänen arviointimenetelmä. Se käyttää analyysissaan vokaali- ja jatkuvan puheen ääninäytettä, ja siksi AVQI validoidaan ennen käyttöönottoa eri kielille. Tässä tutkimuksessa validoitiin AVQI:n uusi, sisäisesti yhdenmukaisempi, pidempää jatkuvan puheen näytettä käyttävä versio (03.01) suomenkielisille puhujille. Tutkimuksessa oli osallistujina 197 vapaaehtoista, äidinkielenään suomea puhuvaa henkilöä, joista 111 oli sairaalan foniatrisen yksikön potilaita ja 86 terveäänisiä. Osallistujilta tallennettiin luenta- ja vokaaliääninäytteet. Luentanäytteistä mitattiin keskimääräinen kolmen sekunnin vokaaliääntöä vastaava tavujen määrä. Kuusitoista asiantuntijakuuntelijaa arvioi neliportaisella asteikolla äänen yleislaatua. Tilastollisilla menetelmillä arvioitiin AVQI-analyysin diagnostista kykyä erotella terve- ja äänihäiriöääni toisistaan suomenkielisellä aineistolla. Kolmen sekunnin vokaaliääntöä vastaavaksi tavumääräksi määritettiin 31 tavua. AVQI-tulosten ja kuunteluarvioiden välinen yhteys oli vahva (Spearmanin rho 0.77, p= 0.01). Paras erottelevuus terveen- ja äänihäiriöäänen välille saatiin raja-arvolla 1,83. Tutkimus osoitti AVQI 03.01FIN -version toimivan hyvin äänihäiriöiden diagnostisena työkaluna

Sparse Density, Leaf-Off Airborne Laser Scanning Data in Aboveground Biomass Component Prediction

The demand for cost-efficient forest aboveground biomass (AGB) prediction methods is growing worldwide. The National Land Survey of Finland (NLS) began collecting airborne laser scanning (ALS) data throughout Finland in 2008 to provide a new high-detailed terrain elevation model. Similar data sets are being collected in an increasing number of countries worldwide. These data sets offer great potential in forest mapping related applications. The objectives of our study were (i) to evaluate the AGB component prediction accuracy at a resolution of 300 m(2) using sparse density, leaf-off ALS data (collected by NLS) derived metrics as predictor variables; (ii) to compare prediction accuracies with existing large-scale forest mapping techniques (Multi-source National Forest Inventory, MS-NFI) based on Landsat TM satellite imagery; and (iii) to evaluate the accuracy and effect of canopy height model (CHM) derived metrics on AGB component prediction when ALS data were acquired with multiple sensors and varying scanning parameters. Results showed that ALS point metrics can be used to predict component AGBs with an accuracy of 29.7%-48.3%. AGB prediction accuracy was slightly improved using CHM-derived metrics but CHM metrics had a more clear effect on the estimated bias. Compared to the MS-NFI, the prediction accuracy was considerably higher, which was caused by differences in the remote sensing data utilized.</p

The nature of supernovae 2010O and 2010P in Arp 299-I. Near-infrared and optical evolution

We present near-infrared and optical photometry, plus optical spectroscopy of two stripped-envelope supernovae (SNe) 2010O and 2010P that exploded in two different components of an interacting luminous infrared galaxy Arp 299 within only a few days of one another. SN 2010O is found to be photometrically and spectroscopically similar to many normal Type Ib SNe and our multiwavelength observations of SN 2010P suggest it to be a Type IIb SN. No signs of clear hydrogen features or interaction with the circumstellar medium are evident in the optical spectrum of SN 2010P. We derive estimates for the host galaxy line-of-sight extinctions for both SNe, based on both light curve and spectroscopic comparison finding consistent results. These methods are also found to provide much more robust estimates of the SN host galaxy reddening than the commonly used empirical relations between extinction and equivalent width of Na i D absorption features. The SN observations also suggest that different extinction laws are present in different components of Arp 299. For completeness, we study high-resolution pre-explosion images of Arp 299 and find both SNe to be close to, but not coincident with, extended sources that are likely massive clusters. A very simple model applied to the bolometric light curve of SN 2010O implies a rough estimate for the explosion parameters of E-k approximate to 3 x 10(51) erg, M-ej approximate to 2.9 M-circle dot and M-Ni approximate to 0.16 M-circle dot.</p

The Massive Progenitor of the Possible Type II-Linear Supernova 2009hd in Messier 66

We present observations of SN2009hd in the nearby galaxy M66. This SN is one of the closest to us in recent years but heavily obscured by dust, rendering it unusually faint in the optical, given its proximity. We find that the observed properties of SN2009hd support its classification as a possible Type II-L SN, a relatively rare subclass of CC-SNe. High-precision relative astrometry has been employed to attempt to identify a SN progenitor candidate, based on a pixel-by-pixel comparison between HST F555W and F814W images of the SN site prior to explosion and at late times. A progenitor candidate is identified in the F814W images only; this object is undetected in F555W. Significant uncertainty exists in the astrometry, such that we cannot definitively identify this object as the SN progenitor. Via insertion of artificial stars into the pre-SN HST images, we are able to constrain the progenitor's properties to those of a possible supergiant, with M(F555W)0>-7.6 mag and (V-I) 0>0.99 mag. The magnitude and color limits are consistent with a luminous RSG; however, they also allow for the possibility that the star could have been more yellow than red. From a comparison with theoretical massive-star evolutionary tracks, which include rotation and pulsationally enhanced mass loss, we can place a conservative upper limit on the initial mass for the progenitor of <20 M_sun. If the actual mass of the progenitor is near the upper range allowed by our derived mass limit, then it would be consistent with that for the identified progenitors of the SNII-L 2009kr and the high-luminosity SNII-P 2008cn. The progenitors of these three SNe may possibly bridge the gap between lower-mass RSG that explode as SNeII-P and LBV, or more extreme RSG, from which the more exotic SNeII-n may arise. Very late-time imaging of the SN2009hd site may provide us with more clues regarding the true nature of its progenitor.Comment: 19 pages, 9 figures, 3 tables, accepted for publication in Ap

Spitzer observations of SN 2014J and properties of mid-IR emission in Type Ia supernovae

SN 2014J in M82 is the closest Type Ia supernova (SN Ia) in decades. The proximity allows for detailed studies of supernova physics and provides insights into the circumstellar and interstellar environment. In this work we analyze Spitzer mid-IR data of SN 2014J in the 3.6 and 4.5 {\mu}m wavelength range, together with several other nearby and well-studied SNe Ia. We compile the first composite mid-IR light-curve templates from our sample of SNe~Ia, spanning the range from before peak brightness well into the nebular phase. Our observations indicate that SNe Ia form a very homogeneous class of objects at these wavelengths. Using the low-reddening supernovae for comparison, we constrain possible thermal emission from circumstellar dust around the highly reddened SN 2014J. We also study SNe 2006X and 2007le, where the presence of matter in the circumstellar environment has been suggested. No significant mid-IR excess is detected, allowing us to place upper limits on the amount of pre-existing dust in the circumstellar environment. For SN 2014J, $M_{dust} < 10^{-5}$ M$_{\odot}$ within $r_{dust} \sim 10^{17}$ cm, which is insufficient to account for the observed extinction. Similar limits are obtained for SNe 2006X and 2007le.Comment: 9 pages, 4 figures. Published in MNRA

How consistent are the transcriptome changes associated with cold acclimation in two species of the Drosophila virilis group?

This work was financially support by a Marie Curie Initial Training Network grant, “Understanding the evolutionary origin of biological diversity” (ITN-2008–213780 SPECIATION), grants from the Academy of Finland to A.H. (project 132619) and M.K. (projects 268214 and 272927), a grant from NERC, UK to M.G.R. (grant NE/J020818/1), and NERC, UK PhD studentship to D.J.P. (NE/I528634/1).For many organisms the ability to cold acclimate with the onset of seasonal cold has major implications for their fitness. In insects, where this ability is widespread, the physiological changes associated with increased cold tolerance have been well studied. Despite this, little work has been done to trace changes in gene expression during cold acclimation that lead to an increase in cold tolerance. We used an RNA-Seq approach to investigate this in two species of the Drosophila virilis group. We found that the majority of genes that are differentially expressed during cold acclimation differ between the two species. Despite this, the biological processes associated with the differentially expressed genes were broadly similar in the two species. These included: metabolism, cell membrane composition, and circadian rhythms, which are largely consistent with previous work on cold acclimation/cold tolerance. In addition, we also found evidence of the involvement of the rhodopsin pathway in cold acclimation, a pathway that has been recently linked to thermotaxis. Interestingly, we found no evidence of differential expression of stress genes implying that long-term cold acclimation and short-term stress response may have a different physiological basis.PostprintPeer reviewe

SN 2011ht: Confirming a Class of Interacting Supernovae with Plateau Light Curves (Type IIn-P)

We present photometry and spectroscopy of the Type IIn supernova (SN) 2011ht, identified previously as a SN impostor. The light curve exhibits an abrupt transition from a well-defined ~120 day plateau to a steep bolometric decline. Leading up to peak brightness, a hot emission-line spectrum exhibits signs of interaction with circumstellar material (CSM), in the form of relatively narrow P-Cygni features of H I and He I superimposed on broad Lorentzian wings. For the remainder of the plateau phase the spectrum exhibits strengthening P-Cygni profiles of Fe II, Ca II, and H-alpha. By day 147, after the plateau has ended, the SN entered the nebular phase, heralded by the appearance of forbidden transitions of [O I], [O II], and [Ca II] over a weak continuum. At this stage, the light curve exhibits a low luminosity that is comparable to that sub-luminous Type II-P supernovae, and a relatively fast visual-wavelength decline that is significantly steeper than the Co-56 decay rate. However, the total bolometric decline, including the IR luminosity, is consistent with Co-56 decay, and implies a low Ni-56 mass of ~0.01 M(Sun). We therefore characterize SN 2011ht as a bona-fide core-collapse SN very similar to the peculiar SNe IIn 1994W and 2009kn. These three SNe define a subclass, which are Type IIn based on their spectrum, but that also exhibit well-defined plateaus and produce low Ni-56 yields. We therefore suggest Type IIn-P as a name for this subclass. Possible progenitors of SNe IIn-P, consistent with the available data, include 8-10 M(Sun) stars, which undergo core collapse as a result of electron capture after a brief phase of enhanced mass loss, or more massive M>25 M(Sun) progenitors, which experience substantial fallback of the metal-rich radioactive ejecta. In either case, the energy radiated by these three SNe during their plateau must be dominated by CSM interaction (abridged).Comment: accepted, post-proof version (includes new data