Correlation energy functional and potential from time-dependent exact-exchange theory

In this work we have studied a new functional for the correlation energy obtained from the exact-exchange (EXX) approximation within time-dependent density functional theory (TDDFT). Correlation energies have been calculated for a number of different atoms showing excellent agreement with results from more sophisticated methods. These results loose little accuracy by approximating the EXX kernel by its static value, a procedure which enormously simplifies the calculations. The correlation potential, obtained by taking the functional derivative with respect to the density, turns out to be remarkably accurate for all atoms studied. This potential has been used to calculate ionization potentials, static polarizabilities and van der Waals coefficients with results in close agreement with experiment.Comment: 6 pages, 2 figure

Cultivar and Year-to-Year Variation of Phytosterol Content in Rye (Secale cereale L.)

Intake of phytosterols (and -stanols) has been shown to decrease the level of low-density lipoprotein cholesterol and thus protect against development of cardiovascular diseases. Therefore, studies on the cultivar and year-to-year variation in phytosterol content in rye grains have been performed. The phytosterol content and composition of different rye cultivars, grown under identical conditions on the same field in three consecutive years, were analyzed. Both cultivar and year-to-year variation in sterol content were statistically significant (p < 0.0001). The total sterol content varied from 1007 ± 21 mg/kg in the highest yielding cultivar, Tsulpan 3, to 761 ± 10 mg/kg in the lowest yielding cultivar (Amando in the 1999 harvest). Because the meteorological conditions varied substantially between the different years, it was possible to deduce the impact of varying weather conditions on phytosterol content in the different cultivars. The studied cultivars had all the lowest phytosterol contents in the dry and warm harvest season of 1999. Although there were statistically significant cultivar and year-to-year variations in the sterol composition (p < 0.0001), these were only between 2 and 4% of the total sterol content

Optimal control of strong-field ionization with time-dependent density-functional theory

We show that quantum optimal control theory (OCT) and time-dependent density-functional theory (TDDFT) can be combined to provide realistic femtosecond laser pulses for an enhanced ionization yield in many-electron systems. Using the H$_2$-molecule as a test case, the optimized laser pulse from the numerically exact scheme is compared to pulses obtained from OCT+TDDFT within the TD exact-exchange (TDEXX) and the TD local-density approximation (TDLDA). We find that the TDDFT-pulses produces an ionization yield of up to 50% when applied to the exact system. In comparison, pulses with a single frequency but the same fluence typically reach to yields around 5-15%, unless the frequency is carefully tuned into a Fano-type resonance that leads to $\sim 30$ yield. On the other hand, optimization within the exact system alone leads to yields higher than 80%, demonstrating that correlation effects beyond the TDEXX and TDLDA can give rise to even more efficient ionization mechanisms

”Styrka är det nya smala” : en diskursanalytisk granskning av svenska träningsbloggar skrivna av kvinnor

Syftet med denna avhandling är att granska hur fitnesskroppen och kvinnlighet konstrueras genom bloggtexter skrivna av svenska bloggerskor. Med fitness i detta sammanhang avses olika former av kroppsbyggning. I detta fall är målet för kvinnorna att tävla inom fitness vilket innebär att de presenterar sina muskulösa och fettsnåla kroppar på en fitnesstävling. Under de senaste åren har antalet gym ökat men även hälsan har blivit ett större individuellt ansvar samtidigt som uppfattningen kring genus blivit mer flexibelt, både när det kommer till identiteten och synen på kroppen. En muskulös kropp uppfattas däremot fortfarande som maskulin. Av denna orsak är det av intresse att studera hur kvinnor med muskler konstruerar sina kroppar och genus genom bloggtexter. Bloggar och sociala medier har fått ett starkt fotfäste i vårt postmoderna samhälle, vilket är orsak till varför specifikt bloggtexter och deras sociala påverkan är av intresse i avhandlingen. Som material fungerar sex stycken fitnessbloggar skrivna av svenska kvinnor som tävlar i olika former av fitness. Kvinnorna är i åldrarna 20-35 år som har dokumenterat sina reflektioner kring fitness, kroppen och genus i sina bloggtexter mellan år 2012 och 2015. Genom att utföra en diskursanalys enligt Foucault har olika diskursiva konstruktioner och subjektspositioner kännetecknats, främst genom att belysa motstridigheterna som uppstår mellan diskurserna. Avhandlingen lyfter fram fyra diskurser som besvarar forskningsfrågorna: hälsodiskursen, dualismdiskursen, diskursen kring egenmakt samt genusdiskursen. Diskurserna är starkt förankrade med varandra och besvarar specifikt på forskningsfrågorna som tangerar fitnesskroppen, kvinnligheten och fitnesskvinnan. Avhandlingen konstaterar att den muskulösa kvinnokroppen konstrueras i bloggtexterna som kvinnlig även om det finns starka motstridigheter i detta. Resultaten visar också att fitnesskroppen är ett resultat av disciplinering och ett individuellt ansvarstagande av hälsan

Engineering central carbon metabolism with phosphoketolase pathways in Saccharomyces cerevisiae

We need more efficient biocatalysts to make sustainable microbial production of chemicals and fuels more profitable before they can replace petroleum-based sources. Rewiring the metabolic pathways in the biocatalysts to avoid the loss of carbon as CO2 can aid in improving product yields and thereby the profitability of the process. In this thesis, I investigated the use of phosphoketolase (PK) pathways in the yeast Saccharomyces cerevisiae to produce the precursor metabolite acetyl-CoA without loss of carbon as CO2. Firstly, we investigated the effect of acetyl-phosphate (AcP) accumulation from the linear PK pathway when downstream product formation is limited. Accumulated AcP was degraded to acetate, which limited the benefit of the PK pathway. Furthermore, we investigated a combinatorial strategy to supply acetyl-CoA and NADPH for fatty acid (FA) production. We combined the PK strategy with overexpression of the transcription factor Stb5 to activate NADPH generating pathways. This strategy increased the FA titer in the glucose phase, but with a counteractive response that possibly arose from the lack of an effective NADPH sink. Secondly, we expanded the linear PK pathway to a novel configuration of the cyclic non-oxidative glycolysis (NOG) that can recycle all the carbon from glucose into acetyl-CoA, thus potentially increasing product yields even further. We showed through kinetic modeling that the new configuration resolves potential bottlenecks in the previous configuration. We verified both in vitro and in vivo functionality of the cycle in S.\ua0cerevisiae. Furthermore, we demonstrated increased titers of an acetyl-CoA-derived product in the glucose phase compared to the linear PK pathway, indicating increased precursor supply from the cycle. Finally, we further characterized the S.\ua0cerevisiae strain with the cycle, using omics. Most notably, the cycle strain yielded respiro-fermentative growth in chemostat cultures with acetate as the main overflow metabolite. This points to a metabolic imbalance and extensive AcP degradation to acetate, which needs to be resolved before the cycle can be efficiently utilized. This thesis highlights the status of this novel NOG configuration and will aid in the further development of cell factories with high-yield production of acetyl-CoA-derived products

From Semantics to Pragmatics

The topic of this thesis is the distinction between semantics and pragmatics. Semantics is concerned with the literal meanings of expressions, what is explicitly expressed with expressions and providing truth conditions for sentences. While the subject matter of pragmatics, being the more nebulous one, is focused on non-literal meanings of expressions, what is implicitly conveyed with expressions and non-truth-conditional content. In this thesis I will present two theories: David Kaplan’s theory of indexicals and demonstratives and Robert Stalnaker’s assertion theory. The guiding question of this work is how these theorists distinguish semantics from pragmatics. How does the distinction appear in their theories? To point out, neither of the theories is aimed to specifically solve how the distinction is to be made. Kaplan’s aim is to create semantics for indexical expressions, whereas Stalnaker wants to explain how necessary a posteriori identity statements can be informative according to his two-dimensional semantic theory. Despite the differing goals underlying their theories, Kaplan and Stalnaker are not oblivious of the distinction between semantics and pragmatics. In fact, how the distinction is eventually made by these theorists, strongly depends on how each of the theories is built.Tutkielmassani käsittelen semantiikan ja pragmatiikan välistä erottelua. Karkeasti ottaen semantiikalla tarkoitetaan tutkimusalaa, joka käsittelee ilmaisujen kirjaimellista merkitystä, mitä ilmaisuilla eksplisiittisesti ilmaistaan sekä lauseiden totuusehtojen muodostamista. Pragmatiikan alaan lasketaan perinteisesti kuuluvan ilmaisujen ei-kirjaimellisen merkityksen tarkastelun, mitä ilmaisuilla implisiittisesti välitetään sekä lauseiden ei-totuusehdollisen sisällön tarkastelun. Esittelen tutkielmassani kaksi teoriaa: David Kaplanin teorian indeksikaaleista ja demonstratiiveista sekä Robert Stalnakerin teorian siitä, miten väittämä vaikuttaa kontekstiin. Tutkielmani keskeinen kysymys on, miten semantiikan ja pragmatiikan välinen erottelu ilmenee Kaplanin ja Stalnakerin teorioissa. Mainittakoon, että kumpikaan teoria ei ensisijaisesti pyri vastaamaan asettamaani kysymykseen. Kaplanin tarkoitus on osoittaa, että indeksikaalisille ilmaisuille voidaan luoda semantiikka. Stalnaker pyrkii puolestaan esittämään, miten välttämättömät a posteriori identiteettiväitteet voivat olla informatiivisia hänen kehittämän kaksiulotteisen semanttisen teorian mukaan. Erilaisista päämääristä huolimatta sekä Kaplan että Stalnaker ovat varsin tietoisia erottelusta semantiikan ja pragmatiikan välillä, mikä ilmenee erityisesti luvussa 4

Beyond mammography : an evaluation of complementary modalities in breast imaging

Breast cancer is the main cause of cancer death among women worldwide and the goal of mammography screening is to reduce breast cancer-specific mortality. The reduction of the sensitivity of mammography for detecting cancer among women with dense breasts requires the use of complementary methods for this subset of women. Three of the projects in this thesis examine the performance of such complementary methods and a fourth study investigates the association between the biomarker BPE (background parenchymal enhancement) and risk factors for breast cancer. In study 1, we prospectively compared the sensitivity and specificity of Automated Breast Volume Scanner (ABVS) with handheld ultrasound for detection of breast cancer among women with a suspicious mammographic finding who were recalled after attending the population-based mammography screening program. We performed both methods on 113 women and found 26 malignant lesions. Analysis was performed in two categories: breasts with a suspicious screening mammography and breasts with a negative screening mammography. In the first category (n=118) the sensitivity of both methods was 88% (p=1.0), the specificity of handheld ultrasound was 93.5 % and ABVS was 89.2%. The difference in specificity was not statistically significant (p=0.29). For breasts without a suspicious mammographic finding, the sensitivity of handheld ultrasound and ABVS was 100% (p=1.0), the specificity was 100% and 94.1% respectively. The difference in specificity was statistically significant (p=0.03). In summary, ABVS has similar sensitivity to handheld ultrasound, but lower specificity in breasts with a negative mammogram. In study 2, we explored the incremental cancer detection rate when adding a threedimensional infrared imaging (3DIRI) score to screening mammography among women with dense breasts (Volpara volumetric density >6 % on the previous mammography examination) who attended the population-based mammography screening program. Women with a negative mammogram and positive 3DIRI score were triaged for a DCEMRI examination to verify the presence of cancer. Of 1727 participants, 7 women had a mammography-detected breast cancer. Among women with a negative mammogram and a positive infrared imaging (n=219), an additional 6 cancers in 5 women were detected on MRI resulting in an incremental cancer detection rate of 22.5 per 1000. Among women with a negative mammography and infrared examination, one woman was diagnosed with breast cancer during the two-year follow-up. The study does not provide information on the proportion of cancers that might have been detected had MRI been performed among women with a negative mammogram and 3DIRI score. Consequently, this study does not shed light on the diagnostic accuracy of infrared imaging or whether using an infrared risk score is the optimal method for identifying women who would benefit from additional imaging modalities. In study 3, we used MRI examinations of study 2 among women without breast cancer (n=214) to explore the association between BPE at DCE-MRI and a large array of risk factors for breast cancer. Thanks to the Karma database, we had unique access to data from self-reporting questionnaires on risk factors. BPE and mammographic density were assessed visually by three radiologists and BPE was further dichotomized into low and high. We created categorical variables for other risk factors. We calculated the univariable associations between BPE and each risk factor and fitted an adjusted logistic regression model. In the adjusted model, we found a negative association with age (p=0.002), and a positive association with BMI (p=0.03). There was a statistically significant association with systemic progesterone (p=0.03) but since only five participants used progesterone preparations, the result is uncertain. Although the likelihood for high BPE increased with increase in mammographic density, the association was not statistically significant (p=0.23). We were able to confirm earlier findings that BPE is associated with age, BMI and progesterone, but we could not find an association with other risk factors for breast cancer. In study 4, we compared the diagnostic accuracy, reading-time, and inter-rater agreement of an abbreviated protocol (aMRI) to the routine full protocol (fMRI) of contrast-enhanced breast MRI. The MRI examinations were performed before biopsy and among women who were not part of a surveillance program due to an increased familial risk of breast cancer. Analysis was performed on a per breast basis. Aggregated across three readers, the sensitivity and specificity were 93.0% and 91.7% for aMRI, and 92.0% and 94.3% for the fMRI. Using a generalized estimating equations approach to compare the two protocols, the difference in sensitivity was not statistically significant (p=0.840), and the difference in specificity was significant (p=0.003). There was a statistically significant difference in average reading time of 67 seconds for aMRI and 126 seconds for the fMRI (p= 0.000). The inter-rater agreement was 0.79 for aMRI and 0.83 for fMRI. We were able to demonstrate that the abbreviated protocol has similar sensitivity to the full protocol even if MRI is performed before biopsy and the images lack telltale signs of malignancy. In conclusion, this thesis provides new knowledge about the biomarker BPE, broadens our knowledge on the diagnostic accuracy of two different imaging modalities and highlights the importance of good study design for diagnostic accuracy studies