Studies of Volcanic Influence on Aerosols, Clouds and Climate

This thesis focuses on the influence of volcanism on the compositions of the aerosols in the upper troposphere (UT) and lowermost stratosphere (LMS), and their direct and indirect impact on climate. Aerosol data were obtained by aircraft-borne sampling, using the CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) platform, and laboratory-based ion beam analysis of aerosol samples at the Lund Ion Beam Analysis Facility (LIBAF). Aerosol composition data were compared to particle size distributions obtained from onboard optical particle counter (OPC) measurements, demonstrating good agreement between the two analysis systems. The impact on climate was investigated using satellite observations of aerosol and optical properties of cirrus clouds. These were provided by the CALIOP and MODIS instruments onboard the NASA satellites CALIPSO, Terra and Aqua. The aerosol load in the LMS has varied considerably since 2000, mainly due to volcanic injections of particles and particleforming gases. Tropical volcanoes affect the LMS for up to two years after eruption, through transport within the Brewer- Dobson circulation. In contrast, extra-tropical volcanoes inject aerosols directly into the LMS, which subside to the UT within months. The eruption of Kasatochi in August 2008 increased the aerosol load in the northern hemisphere LMS by a factor of ~10. Apart from sulfate and ash, both fresh and aged volcanic aerosols contain surprisingly large amounts of carbonaceous aerosols, and the value of the oxygen:carbon ratio (O/C) of ~2 indicates an organic origin. Entrainment of the organic aerosol present in the tropospheric background within volcanic jets and plumes was suggested to be the cause. Using CALIOP data, it was shown that the stratospheric aerosol at altitudes below 15 km constitutes a significant part of the volcanic forcing. During the period from 2008 to the middle of 2012, volcanic forcing in the LMS constituted 30% of that in the rest of the stratosphere. In addition, volcanism was found to have a significant influence on aerosol concentrations in the UT of the northern hemisphere. Comparison with cirrus reflectance (CR) data obtained using the MODIS instrument revealed a strong anti-correlation between the CR and particulate sulfur mass concentration, suggesting that the volcanic aerosol affected midlatitude cirrus clouds. In 2011, the CR was 8% lower than in 2001. Since cirrus clouds warm the Earth, this decrease is associated with regional cooling. The results of these studies show that previous estimates of the impact of volcanism on climate have been underestimated. The investigations of the direct and indirect radiative effects of volcanism on the UT and LMS presented here provide new information on the effect of volcanism on the Earth’s climate. This will allow more realistic estimates of the impact of volcanism on climate variability, and improve climate models providing more realistic projections of future global temperatures

Privatization, Investment and Ownership Efficiency

We provide a model that explains the following empirical observations: i) private ownership is more efficient than public ownership, ii) privatizations are associated with increases in efficiency and iii) the increase in efficiency predates the privatization. The two key mechanisms explaining the results are: (i) a government owner keeping control takes into account the negative effect on employment of investment and (ii) a privatizing government has a stronger incentive to invest than an acquiring firm: the government exploits the fact that investments increase the sales price not only due to the increase in the acquirer's profit, but also due to a reduced profit for the non-acquirer.Privatization; Asset Ownership; Restructuring; Oligopoly

Getting a Better Price: Strategic Behaviour before Changes in Ownership of Corporate Assets

We propose a model of investments prior to corporate ownership changes. We derive conditions under which the selling of a firm triggers overinvestment by both the seller and the buyer prior to the asset transfer. In a setting with Cournot competition, we show that these incentives can drive the consumer prices in a post-acquisition duopoly below those of an ongoing triopoly. Our analysis warns against a mechanical use of pre-merger benchmarks in ex post merger evaluations.Mergers & Acquisitions; Ownership; Auctions; Strategic Investments; Merger Evaluations

Att skapa �verenskommelse - En studie om F�rs�kringskassans organisationsf�r�ndring via ett kommunikationsperspektiv

Syfte: Uppsatsen har som syfte att söka förståelse på anställdas reaktion på organisationsförändring utifrån ett kommunikationsperspektiv. Metod: Till sin karaktär är uppsatsen en fallstudie med en icke generaliserande deduktiv ansats som riktas gentemot Försäkringskassan. Teoretiskt ramverk: Uppsatsen teoretiska ramverk är uppbyggt på en socialkonstruktivistisk grund och riktar fokus gentemot kommunikationens skapande kraft vid organisationsförändring. Empiri: Uppsatsen är baserad på 10 semistrukturerade intervjuer av anställda vid Försäkringskassan. Intervjuerna har sedermera transkriberats för att tydliggöra språkets nyanser. Resultat: Uppsatsen tydliggör att det är kommunikationen eller avsaknaden av densamma som skapar reaktion under en organisationsförändring. Kontinuerlig och aktiv kommunikation från involverade parter skapar förutsättning för organisatoriska överenskommelser och trivsel på arbetsplatsen. Bristande kommunikation skapar hos involverade parter frustration, irritation och bristande förståelse. Utfallet av en organisationsförändring har ett starkt samband med hur organisationen utifrån kommunikation hanterar de olika reaktioner som uppkommer bland personal under en förändring

A Generalised Area Law for Hadronic String Reinteractions

A new model for hadronic string reinteractions based on a generalised area law is presented. The model describes both the hadronic final states in $e^+e^-$ annihilation and the diffractive structure function in deep inelastic scattering. The model also predicts a shift in the W-mass reconstructed from hadronic decays of W-pairs of the order 65 MeV.Comment: 11 pages, 5 figures, see also http://www3.tsl.uu.se/~rathsman/gal/ Slightly shortened version with minor modifications for publicatio

An array of highly flexible electrodes with a tailored configuration locked by gelatin during implantation-initial evaluation in cortex cerebri of awake rats.

A major challenge in the field of neural interfaces is to overcome the problem of poor stability of neuronal recordings, which impedes long-term studies of individual neurons in the brain. Conceivably, unstable recordings reflect relative movements between electrode and tissue. To address this challenge, we have developed a new ultra-flexible electrode array and evaluated its performance in awake non-restrained animals

Intercomparison of in-situ aircraft and satellite aerosol measurements in the stratosphere

Aerosol composition and optical scattering from particles in the lowermost stratosphere (LMS) have been studied by comparing in-situ aerosol samples from the IAGOS-CARIBIC passenger aircraft with vertical profiles of aerosol backscattering obtained from the CALIOP lidar aboard the CALIPSO satellite. Concentrations of the dominating fractions of the stratospheric aerosol, being sulphur and carbon, have been obtained from post-flight analysis of IAGOS-CARIBIC aerosol samples. This information together with literature data on black carbon concentrations were used to calculate the aerosol backscattering which subsequently is compared with measurements by CALIOP. Vertical optical profiles were taken in an altitude range of several kilometres from and above the northern hemispheric extratropical tropopause for the years 2006-2014. We find that the two vastly different measurement platforms yield different aerosol backscattering, especially close to the tropopause where the influence from tropospheric aerosol is strong. The best agreement is found when the LMS is affected by volcanism, i.e., at elevated aerosol loadings. At background conditions, best agreement is obtained some distance (>2 km) above the tropopause in winter and spring, i.e., at likewise elevated aerosol loadings from subsiding aerosol-rich stratospheric air. This is to our knowledge the first time the CALIPSO lidar measurements have been compared to in-situ long-term aerosol measurements. © 2019, The Author(s)

Population pharmacokinetics of apramycin from first-in-human plasma and urine data to support prediction of efficacious dose

BACKGROUND: Apramycin is under development for human use as EBL-1003, a crystalline free base of apramycin, in face of increasing incidence of multidrug-resistant bacteria. Both toxicity and cross-resistance, commonly seen for other aminoglycosides, appear relatively low owing to its distinct chemical structure. OBJECTIVES: To perform a population pharmacokinetic (PPK) analysis and predict an efficacious dose based on data from a first-in-human Phase I trial. METHODS: The drug was administered intravenously over 30 min in five ascending-dose groups ranging from 0.3 to 30 mg/kg. Plasma and urine samples were collected from 30 healthy volunteers. PPK model development was performed stepwise and the final model was used for PTA analysis. RESULTS: A mammillary four-compartment PPK model, with linear elimination and a renal fractional excretion of 90%, described the data. Apramycin clearance was proportional to the absolute estimated glomerular filtration rate (eGFR). All fixed effect parameters were allometrically scaled to total body weight (TBW). Clearance and steady-state volume of distribution were estimated to 5.5 L/h and 16 L, respectively, for a typical individual with absolute eGFR of 124 mL/min and TBW of 70 kg. PTA analyses demonstrated that the anticipated efficacious dose (30 mg/kg daily, 30 min intravenous infusion) reaches a probability of 96.4% for a free AUC/MIC target of 40, given an MIC of 8 mg/L, in a virtual Phase II patient population with an absolute eGFR extrapolated to 80 mL/min. CONCLUSIONS: The results support further Phase II clinical trials with apramycin at an anticipated efficacious dose of 30 mg/kg once daily

Systemic and Intra-Nodal Activation of NK Cells After Rituximab Monotherapy for Follicular Lymphoma

Monotherapy with the anti-CD20 monoclonal antibody rituximab can induce complete responses (CR) in patients with follicular lymphoma (FL). Resting FcRγIII+ (CD16+) natural killer (NK) cells respond strongly to rituximab-coated target cells in vitro. Yet, the contribution of NK cells in the therapeutic effect in vivo remains unknown. Here, we followed the NK cell repertoire dynamics in the lymph node and systemically during rituximab monotherapy in patients with FL. At baseline, NK cells in the tumor lymph node had a naïve phenotype albeit they were more differentiated than NK cells derived from control tonsils as determined by the frequency of CD56dim NK cells and the expression of killer cell immunoglobulin-like receptors (KIR), CD57 and CD16. Rituximab therapy induced a rapid drop in NK cell numbers coinciding with a relative increase in the frequency of Ki67+ NK cells both in the lymph node and peripheral blood. The Ki67+ NK cells had slightly increased expression of CD16, CD57 and higher levels of granzyme A and perforin. The in vivo activation of NK cells was paralleled by a temporary loss of in vitro functionality, primarily manifested as decreased IFNγ production in response to rituximab-coated targets. However, patients with pre-existing NKG2C+ adaptive NK cell subsets showed less Ki67 upregulation and were refractory to the loss of functionality. These data reveal variable imprints of rituximab monotherapy on the NK cell repertoire, which may depend on pre-existing repertoire diversity