Precision- and time study of altimeters on standing trees

Skogsmästarstudenter på SLU har i sitt examensarbete studerat och jämfört precisionen samt tidsåtgången mellan tre olika höjdmätare. Ett träds höjd används vid flera olika sammanhang, exempelvis används trädets höjd som en komponent vid beräkning av trädets biomassa. Baserat på uppskattad biomassa i ett träd kan mängden bunden koldioxid beräknas för dels det enskilda trädet eller på fastighetsnivå. Uppskattning av trädets volym utförs bland annat med hjälp av trädets höjd, grundyta och ett formtal som ska motsvara trädets avsmalning. Höjden på stående skog kan uppskattas med flertalet metoder. Exempel på sådana är, drönare, laserdata och mindre handenheter. Det finns ett stort utbud av mindre handenheter. Det huvudsakliga syftet för denna studie är att jämföra tre olika höjdmätare, Haglöf Vertex laser 2 VL402, Arboreals mobilapplikation och pinnen. Studien behandlar vilken mätmetod som ger det mest korrekta värdet utifrån den verkliga höjden. Studien jämför även mätningarnas tidsåtgång för att se vilken utav höjdmätarna som är effektivast. Resultatet baseras på totalt 180 mätningar på 30 träd i olika höjder. Två mätningar per träd och höjdmätare. Facit till mätningarna utgörs av en kontrollmätning på varje träd som gjorts efter att träden fällts. Det visar sig att mobilapplikationen Arboreal har de minsta avvikelserna mellan de olika mätarna med ett spann från 0,05 - 1,78 meter från den verkliga höjden med ett avvikande medelvärde på 0,2 meter. Arboreal underskattar i snitt varje träds höjd med 0,2 meter. Att Arboreal underskattar höjden bevisas då medelvärdet för varje höjd presenteras, det verkliga medelvärdet för alla trädens höjd är 21,76 meter och Arboreals medelvärde är 21,56 meter. Pinnen underskattar trädens i höjd i snitt med 1,09 meter, detta ligger längst ifrån det verkliga värdet. Vertex höjdmätare har en bra precision men överskattar höjden och avviker i snitt med 0,3 meter ifrån det verkliga värdet. Tidsstudien visade att Vertex är den effektivaste mätmetoden, genomsnittstiden per träd är 10,8 sekunder, lite drygt 40 sekunder snabbare än Pinnen som i snitt mäter ett träds höjd på 52,5 sekunder. Mellan den minst effektiva mätmetoden Pinnen och den mest effektiva mätmetoden Vertex ligger Arboreal med en genomsnittstid per träd på 35,9 sekunder per träd. Hypotesprövning kunde bevisa med 99,9 procents säkerhet att Vertex är den mest effektiva höjdmätaren.In a bachelors ‘degree project, forestry students at SLU have studied the precision of three different altimeters, they have also studied the time that each one of the altimeters needs to establish the hight of a standing tree. The height of a tree is used in several different contexts, for example the height of the tree is used as a component in calculating the tree's biomass. Based on the estimated biomass of a tree, the amount of bound carbon dioxide can be calculated for both the individual tree and at the property level. Estimation of the volume of the tree is performed partly with the help of the height of the tree, the base surface and a shape number that must correspond to the tree's taper. The height of standing forest can be estimated with several methods, such as drones, laser data and with smaller handsets. There is a large selection of smaller handsets. The main purpose of this study is to compare three different altimeters, Haglöf Vertex laser 2 VL402, Arboeral's mobile application and Pinnen. The aim of the study is to see which measurement method has the most correct value based on the actual height, further purpose is to compare the time consumption of the measurements to see which of the altimeters is the most effective. The result consists of a total of 180 measurements on 30 different trees. Two measurements per tree and altimeter. The answer to the real hight of the trees was given when the trees were felled and measured on the ground. It turns out that the mobile application Arboreal has the smallest deviations between the different altimeters, with a range from 0.05 - 1.78 meters and a deviating average of 0.2 meters, Arboreal underestimates the average height of each tree by 0.2 meters. The fact that arboreal underestimated the height is proved when the mean value for each height is represented. The real average for all the tree heights is 21.75 meters and Arboreal's average were 21.55 meters. The stick underestimates the height of the trees by an average of 1.09 meters and is furthest from the real value. Vertex has good precision but overestimates the height and deviates on average by 0.3 meters from the fair value. The time study showed that Vertex is the fastest for measuring height, the average time per tree is 10.8 seconds, a little over 40 seconds faster than Pinnen, which on average measures a tree's height in 52.5 seconds. Between Pinnen and Vertex is Arboreal with an average time per tree of 35.9 seconds. Hypothesis testing could prove that with 99.9 percent certainty that Vertex is the fastest altimeter in this study

Determination of Thermal Expansion Coefficients and Locating the Temperature-Induced Phase Transition in Methylammonium Lead Perovskites Using X-ray Diffraction

Lead halogen perovskites, and particularly methylammonium lead iodine, CH3NH3PbI3, have recently attracted considerable interest as alternative solar cell materials, and record solar cell efficiencies have now surpassed 20%. Concerns have, however, been raised about the thermal stability of methylammonium lead iodine, and a phase transformation from a tetragonal to a cubic phase has been reported at elevated temperature. Here, this phase transition has been investigated in detail using temperature-dependent X-ray diffraction measurements. The phase transformation is pinpointed to 54 degrees C, which is well within the normal operating range of a typical solar cell. The cell parameters were extracted as a function of the temperature, from which the thermal expansion coefficient was calculated. The latter was found to be rather high (alpha(v) = 1.57 X 10(-4) K-1) for both the tetragonal and cubic phases. This is 6 times higher than the thermal expansion coefficient for soda lime glass and CIGS and 11 times larger than that of CdTe. This could potentially be of importance for the mechanical stability of perovskite solar cells in the temperature cycling experienced under normal day night operation. The experimental knowledge of the thermal expansion coefficients and precise determination of the cell parameters can potentially also be valuable while conducting density functional theory simulations on these systems in order to deliver more accurate band structure calculations

Replicative and non-replicative mechanisms in the formation of clustered CNVs are indicated by whole genome characterization

Clustered copy number variants (CNVs) as detected by chromosomal microarray analysis (CMA) are often reported as germline chromothripsis. However, such cases might need further investigations by massive parallel whole genome sequencing (WGS) in order to accurately define the underlying complex rearrangement, predict the occurrence mechanisms and identify additional complexities. Here, we utilized WGS to delineate the rearrangement structure of 21 clustered CNV carriers first investigated by CMA and identified a total of 83 breakpoint junctions (BPJs). The rearrangements were further sub-classified depending on the patterns observed: I) Cases with only deletions (n = 8) often had additional structural rearrangements, such as insertions and inversions typical to chromothripsis; II) cases with only duplications (n = 7) or III) combinations of deletions and duplications (n = 6) demonstrated mostly interspersed duplications and BPJs enriched with microhomology. In two cases the rearrangement mutational signatures indicated both a breakage-fusion-bridge cycle process and haltered formation of a ring chromosome. Finally, we observed two cases with Alu- and LINE-mediated rearrangements as well as two unrelated individuals with seemingly identical clustered CNVs on 2p25.3, possibly a rare European founder rearrangement. In conclusion, through detailed characterization of the derivative chromosomes we show that multiple mechanisms are likely involved in the formation of clustered CNVs and add further evidence for chromoanagenesis mechanisms in both "simple" and highly complex chromosomal rearrangements. Finally, WGS characterization adds positional information, important for a correct clinical interpretation and deciphering mechanisms involved in the formation of these rearrangements.Peer reviewe

Cytogenetically visible inversions are formed by multiple molecular mechanisms

Cytogenetically detected inversions are generally assumed to be copy number and phenotypically neutral events. While nonallelic homologous recombination is thought to play a major role, recent data suggest the involvement of other molecular mechanisms in inversion formation. Using a combination of short-read whole-genome sequencing (WGS), 10X Genomics Chromium WGS, droplet digital polymerase chain reaction and array comparative genomic hybridization we investigated the genomic structure of 18 large unique cytogenetically detected chromosomal inversions and achieved nucleotide resolution of at least one chromosomal inversion junction for 13/18 (72%). Surprisingly, we observed that seemingly copy number neutral inversions can be accompanied by a copy-number gain of up to 350 kb and local genomic complexities (3/18, 17%). In the resolved inversions, the mutational signatures are consistent with nonhomologous end-joining (8/13, 62%) or microhomology-mediated break-induced replication (5/13, 38%). Our study indicates that short-read 30x coverage WGS can detect a substantial fraction of chromosomal inversions. Moreover, replication-based mechanisms are responsible for approximately 38% of those events leading to a significant proportion of inversions that are actually accompanied by additional copy-number variation potentially contributing to the overall phenotypic presentation of those patients.Funding Agencies|Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentUnited States Department of Health &amp; Human ServicesNational Institutes of Health (NIH) - USANIH Eunice Kennedy Shriver National Institute of Child Health &amp; Human Development (NICHD) [NICHD R03 HD092569]; Hjarnfonden; Kungliga Fysiografiska Sallskapet i Lund</p