Estmating groundwater changes in the Rufiji basin by using data from the GRACE satellites

HG 13 2014 Preface This Bachelor's thesis is Carl Lindgren's degree project in Hydrology and Hydrogeology at the Department of Physical Geography and Quaternary Geology, Stockholm University. The Bachelor's thesis comprises 15 credits (one half term of full-time studies). Supervisor has been Steve Lyon at the Department of Physical Geography and Quaternary Geology, Stockholm University. Examiner has been Ian Brown at the Department of Physical Geography and Quaternary Geology, Stockholm University. The author is responsible for the contents of this thesis. Stockholm, 11 July 2014 Lars-Ove Westerberg Director of studies Estimating groundwater changes in the Rufiji basin by using data from the GRACE satellites 1 Abstract Groundwater is an important water resource and vital for providing water to sustain human life and livelihoods around the world. It is a renewable resource but recharge is often a slow process and there is therefore a significant risk for overuse. It is therefor of importance to monitor how groundwater develops over time, which is a difficult process as changes in groundwater are difficult and expensive to measure. This becomes an even larger issue in developing countries or areas where measurements in the field cannot be performed due to political or economic reasons. The launch of the GRACE satellites in 2002 made it possible to follow groundwater developments through remote sensing and this possibility has been used in numerous studies around the world. This study used the methods developed in previous studies to measure groundwater developments in the Rufiji basin in Tanzania. For the study period 2003 to 2012 no clear trends could be identified in groundwater and the larger variations that occurred during the period coincided with years of more or less precipitation than average precipitation. There is a strong seasonality in groundwater with the lowest levels prior to the rainy season and the highest levels at the end of the rainy season that clearly could be identified from the GRACE data. Although data from the GRACE satellites are a very powerful tool to monitor groundwater developments the low spatial resolution limits its practical applications. For the Rufiji basin, which has large variation in topography and human concentration, groundwater developments are likely to be unevenly distributed which cannot be measured using GRACE due to this spatial limitation

Carotenoid Biosynthesis in Seed of Arabidopsis thaliana

Seed of Arabidopsis thaliana accumulate carotenoids during development. These are mainly β-carotene, violaxanthin and lutein. By overexpression of an endogenous phytoene synthase (psy) under control of the seed-specific napin (nap) promoter the carotenoid content was elevated, resulting in increased levels in mainly β-carotene, violaxanthin, lutein and α-carotene. Transgenic seeds were also found to contain increased levels of ABA and displayed a delay in germination. The levels of ABA had a good correlation to the varying increases in lutein and violaxanthin content in seeds from plants hemizygous for the nap:psy construct. Seeds from plants overexpressing a β-carotene ketolase (bkt) from the green algae Haematococcus pluvialis, also under control of the napin promoter contained small amounts of ketocarotenoids, mainly 4-keto-lutein. When plants carrying the nap:bkt construct were crossed to plants carrying nap:psy this resulted in seeds where the total ketocarotenoid content had increased up to 13-fold. In seeds of the aba1-3 mutant of Arabidopsis which is mutated in the zeaxanthin epoxididase (zep) zeaxanthin levels were increased up to 40-fold and in seed of plants overexpressing an endogenous β-carotene hydroxylase (bch) it was found that the violaxanthin content had increased up to 20-fold. In seed from plants transgenic for nap:bch, neoxanthin and ABA levels were also increased. Just as for plants transgenic for nap:psy these seeds displayed a delay in germination. When γ-tocopherol content was analysed it was found that in seeds of nap:psy and nap:bch transformants it was only half of that found in wild type. In the Arabidopsis mutant abscisic acid-insensitive 3-1 (abi3-1) that is mutated in a seed-specific transcription factor, the seeds were found to have increased levels of β-carotene, violaxanthin, lutein and γ-tocopherol

Flugrullen Flyropa

Validerat; 20101217 (root

Real-time wood moisture-content determination using dual-energy X-ray computed tomography scanning

The estimation of the pixel-wise distribution of the moisture content (MC) in wood using X-ray computed tomography (CT) requires two scans of the same wood specimen at different MCs, one of which is known. Image-processing algorithms are needed to compensate for the anisotropic distortion that wood undergoes as it dries. An alternative technique based on dual-energy CT (DECT) to determine MC in wood has been suggested by several authors. The purpose of the present study was to evaluate the hypothesis that DECT can be used for the determination of MC in real time. A method based on the use of the quotient between the linear attenuation coefficients (μ) at different acceleration voltages (the so-called quotient method) was used. A statistical model was created to estimate the MC in solid sapwood of Scots pine, Norway spruce and brittle willow. The results show a regression model with R2 &gt; 0.97 that can predict the MC in these species with a RMSE of prediction of 0.07, 0.04 and 0.11 (MC in decimal format) respectively and at MC levels ranging from the green to the totally dry condition. Individual measurements of MC show an uncertainty of up to ±0.4. It is concluded that under the conditions prevailing in this study, and in studies referred to in this paper, it is not possible to measure MC with DECT.Validerad;2019;Nivå 2;2019-10-24 (johcin)</p

BODYGUARD is required for the biosynthesis of cutin in Arabidopsis

International audienceThe cuticle plays a critical role in plant survival during extreme drought conditions. There are, however, surprisingly, many gaps in our understanding of cuticle biosynthesis. An Arabidopsis thaliana T-DNA mutant library was screened for mutants with enhanced transpiration using a simple condensation spot method. Five mutants, named cool breath (cb), were isolated. The cb5 mutant was found to be allelic to bodyguard (bdg), which is affected in an a/bhydrolase fold protein important for cuticle structure. The analysis of cuticle components in cb5 (renamed as bdg-6) and another T-DNA mutant allele (bdg-7) revealed no impairment in wax synthesis, but a strong decrease in total cutin monomer load in young leaves and flowers. Root suberin content was also reduced. Overexpression of BDG increased total leaf cutin monomer content nearly four times by affecting preferentially C18 polyunsaturated x-OH fatty acids and dicarboxylic acids. Whole-plant gas exchange analysis showed that bdg-6 had higher cuticular conductance and rate of transpiration; however, plant lines overexpressing BDG resembled the wild-type with regard to these characteristics. This study identifies BDG as an important component of the cutin biosynthesis machinery in Arabidopsis. We also show that, using BDG, cutin can be greatly modified without altering the cuticular water barrier properties and transpiration

Requirements for accessing data in network storage

So far, the intended scope of the DECoupled Application Data Enroute (DECADE) working group has mainly been focused on peer-to-peer (P2P) applications. There are however many non-P2P-based applications that could also benefit from in-network storage for caching content. The target of DECADE should thus be to specify a mechanism that is also suitable for generic applications with certain characteristics and not only P2P applications. This document enumerates a number of requirements that should be considered during the design and implementation of this mechanism.Work in progress4WARDNetIn