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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of microsatellite markers in Cannabis Sativa for fingerprinting and genetic relatedness analyses

Al-Ghanim, Hussain J. 09 January 2003 (has links)
Microsatellite markers were developed for Cannabis sativa L. (marijuana) to estimate the level of polymorphism, usefulness for DNA typing (genotype identification), and to measure the genetic relationships between the different plants. Twelve different oligonucleotide probes were used to screen an enriched microsatellite library of Cannabis sativa in which 49% of the clones contained microsatellite sequences. Characterization of microsatellite loci in Cannabis revealed that GA/CT was the most abundant class of isolated microsatellites representing 50% overall. Eleven polymorphic SSR markers were developed, derived from dinucleotide motifs and eight from trinucleotide motifs. A total of 52 alleles were detected averaging 4.7 alleles/locus. The expected heterozygosity of the eleven loci ranged between 0.368 and 0.710 and the common probability of identical genotypes was 1.8 x 107. The loci identified 27 unique profiles of the 41 Cannabis samples. The eleven microsatellite markers developed in this study were found to be useful for DNA fingerprinting and for assessing genetic relationships in Cannabis.
2

How the E. Coli Hsp70 Molecular Chaperone, DnaK, Binds a Client Protein

Tilitsky, Joseph 27 October 2017 (has links)
Protein folding is essential for all cellular life. While some proteins are able to reach their folded state reliably using nothing but their amino acid sequence, a great number of essential proteins are unable to do so without the aid of molecular chaperones. One family of molecular chaperone, the Hsp70 family, is found in virtually all cell types and across all domains of life. Certain to the function of Hsp70s are how they bind their client proteins. Substantial effort has been expended to study how Hsp70s work on model peptides as a substrate mimic, but relatively little work has been performed using full-length protein substrates. This work examines how the E. coli Hsp70, DnaK, binds a full-length unfolded client protein, the pro-form of E. coli alkaline phosphatase, or proPhoA. I use a combination of biophysical techniques to under how DnaK binds proPhoA with regards to affinity, stoichiometry, and binding site selection. I find that DnaK binds each vii of the potential binding sites within proPhoA with roughly equal affinity. In addition, DnaK for a complex with proPhoA with a 1:1 stoichiometry and is selective for a single binding site on proPhoA.
3

Experiments on the Inactivation of Zinc by the Mineral Fractions of the Soil

Hassett, John J. 01 May 1967 (has links)
Zinc deficiency, in many cases, is closely related to organic matter decomposition. DeRemer and Smith (1964) studied the effects of decomposing sugar beet tops on the reactions of Zn65 in a Portneuf soil. They found that with time the Zn65 associated with lime minerals, eschangable, and water soluble fractions of the soil decreased, while that found with the organic and mineral fractions increases. This increase in the mineral fraction is of particular interest, since the majority of the Zn65 was found to be with this fraction after a period of time. They also showed that the increase in Zn65 associated with sand-silt size fraction after a rough separation was greater than with the clay fraction. Smith, Henry, and Shourky (1965) studied the Zn65 associated with the organic fraction as it changed with time. They found that the Zn65 associated with the fulvic acid increased rapidly during early incubation periods, but in the later incubation periods had decreased considerably and was found in the mineral fraction. Shourky (1966), in a study of the effect of decomposing organic matter on the available Zn65 as determined with various reagents, found that after 12 weeks incubation a great portion of the Zn65 was found associated with the mineral fraction.
4

Weighted Density Approximations for Kohn-Sham Density Functional Theory

Cuevas-Saavedra, Rogelio 10 1900 (has links)
<p>Approximating the exchange-correlation energy in density functional theory (DFT) is a crucial task. As the only missing element in the Kohn-Sham DFT, the search for better exchange-correlation functionals has been an active field of research for fifty years. Many models and approximations are known and they can be summarized in what is known as the Jacob’s ladder. All the functionals in that ladder are local in the sense that they rely on the information of only one electronic coordinate. That is, even though the exchange-correlation hole, the cornerstone in density functional theory, is a two-electron coordinate quantity, one of the coordinates is averaged over in “Jacob’s ladder functionals.” This makes the calculations considerably more efficient. On the other hand, some of the important constraints on the form of the exchange-correlation functional become inaccessible in the one-point forms. The violation of these constraints leads to functionals plagued by systematic errors, leading to qualitatively incorrect descriptions of some chemical and physical processes.</p> <p>In this thesis the idea of a weighted density approximation (WDA) is explored. More specifically, a symmetric and normalized two-point functional is proposed for the exchange-correlation energy functional. The functional is based entirely on the hole for the uniform electron gas. By construction, these functionals fulfill two of the most important constraints: the normalization of the exchange-correlation hole and the uniform electron gas limit. The findings suggest that we should pursue a whole new generation of “new Jacob’s ladder” functionals.</p> <p>A further step was considered. Given the relevance of the long-range behavior of the exchange-correlation hole, a study of the electronic direct correlation function was performed. The idea was to build up the long-range character of the hole as convoluted pieces of the simple and short-ranged direct correlation function. This direct correlation function provides better results, at least for the correlation energy in the spin-polarized uniform electron gas.</p> <p>The advantage of one-point functionals is their computational efficiency. We therefore attempted to develop new methods that mitigate the relative computational inefficiency of two-point functionals. This led to new methods for evaluating the six-dimensional integrals that are inherent to the exchange-correlation energy.</p> / Doctor of Philosophy (PhD)
5

Recombinant expression of Verrucomicrobium spinosum tyrosinase in Escherichia coli, its purification and characterisation

Winroth, Lena January 2019 (has links)
No description available.
6

Förslag på riktvärden för sulfathalter i ytvatten

Jonsson, Julia January 2019 (has links)
Detta examensarbete kommer att vara den avslutande delen i mina studier inom samhällsbyggnads-programmet vid Luleå tekniska universitet. Under min verksamhetsförlagda utbildning, på WSP Sverige AB har jag fått arbeta i uppdrag där kunskaper om vattenkemi och biologi har behövts. Syftet med examenarbetet är att undersöka möjliga förslag på riktvärden för sulfathalter i ytvatten. Examensarbetet tog sin början med att formulera frågeställningar att forma arbetet kring. Utifrån frågeställningarna har jag sedan börjat undersöka vilka länder som har riktvärden för sulfathalter implementerat i miljölagstiftningen. Valet var självklart, att hitta ett land med liknande klimat som norra Sverige för att riktvärdena skulle vara relevanta och trovärdiga. Valet blev att undersöka riktvärden i Kanada. Under examensarbetets gång har jag fått lära mig mycket. Till exempel att kunna läsa och ta till mig information om toxikologiska undersökningar och förstå dess relevans. Detta har i sin tur lett till att jag lärt mig nya begrepp som används inom området miljö och vatten. Jag har även fått en inblick över hur komplext och stort arbetet området miljö och vatten är och fått en bra grund att stå på inför kommande utmaningar i mitt framtida yrkesliv.
7

Digitala läromedel i kemi? : En undersökning av hur de digitala läromedel i kemi för grundskolans senare del som finns på marknaden ser ut.

Lindberg, Emma January 2018 (has links)
Samhället har genomgått en förändring från analoga system till digitala.Läromedel som används i skolan behöver följa med i utvecklingen. Syftet meddenna studie är att undersöka hur digitala läromedel i kemi ser ut. Det är även avintresse att ta reda på hur de digitala läromedlen gör för att skapa en bild avämnet kemi som är intresseväckande och intressant samt om dessa digitalaläromedel är utformade för att tillgodose det syfte som presenteras i kursplanenför kemi i grundskolan. Tre olika läromedel, Kemi Direkt från Sanomautbildning, PLUS Kemi från Natur &amp; Kultur och Spektrum Kemi från Liber AB,undersöks med hänsyn till flera olika punkter och aspekter. Undersökningenomfattar hur dessa digitala läromedel presenteras för läsaren, vad det finns förolika möjligheter att ta del av materialet, vilka anpassningar läromedlettillhandahåller för såväl svaga som starka elever, vad det finns för material föratt underlätta planering, laborationer och bedömning. Vidare vad det finns föruppgifter och hur dessa uppgifter rättas eller bedöms, om de olika syftenauppfylls samt hur intressant och förstående är den information som presenterasom växthuseffekten och den förhöjda växthuseffekten. Alla tre läromedel finnssom fysiska böcker som sedan har digitaliserats och på olika sätt anpassats föratt finnas tillgängliga digitalt. Det medför att de inte upplevs som innovativa ochintressanta digitala läromedel även om det såklart inte heller finns stora fel ochbrister. Det framkommer att Spektrum Kemi är det läromedel som uppvisar denstörsta responsen på de undersökta parametrarna. Önskvärt skulle vara ett nyttläromedel som inte är en digitalisering av en tidigare förlaga utan som är skapadför att vara digital och använder tekniken och den digitala världens alla finesseroch möjligheter.
8

The cloning of the clrA gene of Ideonella dechloratans / Kloning av clrA-genen hos Ideonella dechloratans

Moonen, Nele January 2017 (has links)
No description available.
9

Solid Polymer Lithium-ion Conducting Electrolytes for Structural Batteries

Willgert, Markus January 2012 (has links)
<p>QC 20121207</p>
10

Hur påverkar lösligt β-glukan GI-värdet? : Analys av vetebaserat bröd

Ehlin, Sarah January 2020 (has links)
The work was done in collaboration with Lantmännen's research foundation to produce a new and health-promoting bread. The dietary fiber beta-glucan was added to bread at a sufficiently high content to have positive health effects on blood cholesterol and blood sugar levels. The bread should also have a high sensory quality. In this project the effects of addition of beta-glucan on the theoretical GI (glycemic index) and GL (glycemic load) were investigated. An in vitro analysis was used, and the GL was calculated from the GI. These analyses were carried out on both freeze-dried bread and fresh bread containing different concentrations of beta-glucan. A sensory analysis was also done to see if there was any difference between the control bread and the bread containing the beta-glucan. The purpose of the work was to investigate how the theoretical GI value and the theoretical GL value are affected by two different preparations of beta-glucan (with concentration of 32% respectively 75% beta-glucan) in bread with end concentrations of 0.2 and 2.0 % beta-glucan of the total quantity of flour. The result indicates that there is significant effect on GI and GL of beta-glucan in wheat-based bread. Between the reference bread and the 0.2% bread of the freeze-dried bread, a significant difference was seen with a p-value of 0.048 in a paired t-test. It also was a significant difference between the reference bread and the 2.0% bread with a pvalue of 0.014 in a paired t-test. The GI values were calculated to 65 and 63 respectively for 0.2 and 2.0% beta glucan for the freeze-dried bread. The GI value for the fresh bread were calculated to 68 and 52 respectively for 0.2 and 2.0% beta glucan. The GL-values for the fresh-bread were calculated to 79 and 60 respectively for 0.2 and 2.0% beta glucan. The GL-values for the freeze-dried bread were calculated to 38 and 37 respectively for 0.2 and 2.0% beta glucan. A significant difference was seen between the reference bread and thefresh bread containing 2% added betaglucan (p-value = 0.002using t-test). The fresh bread with 0.2% added betaglucan had at about the same GI value as the reference bread and a significant difference could not be seen (p = 0.7642). In other studies, whole grain flour and a dietary fiber content of 15-45 g / serving have been shown to have an effect on the GI and GL values. The desired result is to have attenuated effects on blood sugar levels in the blood after food intake and thus be able to achieve prerequisites for blood sugar claims. To achieve the desired effect a whole-wheat flour should be used to raise the dietary fiber content and reduce the proportion of wheat flour and glucose available.

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