Sökresultat

Herbivory is an important part of most ecosystems and affects the ecosystems' carbon balance both directly and indirectly. Little is known about herbivory and its impact on the carbon balance in high arctic mire ecosystems. We hypothesized that trampling and grazing by large herbivores influences the vegetation density and composition and thereby also the carbon balance. In 2010, we established fe

Multi taper spectrogram decomposition of the time-lag kernel of a time-frequency distribution might result in computationally efficient calculations if the number of multi tapers to be considered in the spectrogram are small. In this paper, penalty functions are designed and used in the computation of multi tapers corresponding to the Wigner distribution time-lag kernel. The resulting multi taper

A new program of Compton scattering on deuterium is under way at the tagged-photon facility at MAX-Lab in Lund, Sweden. We will measure differential cross sections between 60A degrees and 150A degrees over the photon energy range 60-115 MeV in 5 MeV steps, with the ultimate goal of obtaining new precision information on the electric and magnetic polarizabilities of the neutron.

Population fluctuations and synchrony influence population persistence; species with larger fluctuations and more synchronised population fluctuations face higher extinction risks. Here, we analyse the effect of diet specialisation, mobility, length of the flight period, and distance to the northern edge of the species' distribution in relation to between-year population fluctuations and synchrony

Background: Misuse of substances is a major contributor to disability and mortality worldwide. The use of tobacco, alcohol, and illegal drugs in adolescence and young adulthood are well-known risk factors for subsequent substance-related harms. A better understanding of adolescent and young adult substance use behaviors and their correlates might help develop new prevention programs. This thesis a

A search for diphoton events with large missing transverse momentum has been performed using proton-proton collision data at is root s = 7 TeV recorded with the ATLAS detector, corresponding to an integrated luminosity of 4.8 fb(-1). No excess of events was observed above the Standard Model prediction and model-dependent 95% confidence level exclusion limits are set. In the context of a generalise

Energy spectra of superconducting nanospheres observed via tunneling spectroscopy are theoretically discussed. In the energy gap we find small peaks which correspond to the two-particle dynamics beyond the mean-field BCS approximation. These peaks promise to be a sensitive test of theories of superconductivity as their number and positions depend on the approximation used.

Wind and ocean currents may potentially have important effects on travelling animals, as an animal which does not respond to lateral flow will be drifted from its intended direction of movement. By analysing daily movements of migrating ospreys Pandion haliaetus and marsh harriers Circus aeruginosus, as recorded by satellite telemetry, in relation to global wind data, we showed that these raptors

Background: Excessive and inappropriate use of antibiotics is considered to be the most important reason for development of bacterial resistance to antibiotics. As antibiotic resistance may spread across borders, high prevalence countries may serve as a source of bacterial resistance for countries with a low prevalence. Therefore, bacterial resistance is an important issue with a potential serious

In this study the excited-state dynamics of protochlorophyllide a (PChlide), the substrate of the enzyme protochlorophyllide oxidoreductase, was examined by means of time-resolved absorption anisotropy and magic-angle measurements. The solvent polarity dependent anisotropy data provide strong evidence for the existence of an excited-state with charge-transfer character. A solvent dependency is als

The purpose of the present study was to explore the risk for complications and reoperations following open repairs for sliding groin hernias.

In this work we investigated the ability of a series of amino acids to act as cloud condensation nuclei using a static thermal gradient diffusion type cloud condensation nucleus counter. Particles of pure dry l-glycine, glycyl-glycine, l-serine, l-methionine, l-glutamic acid, l-aspartic acid, and l-tyrosine were studied as well as internally mixed dry particles containing ammonium sulfate and one

Colossal magnetoresistance (CMR) is associated with the phase transition from a metallic ferromagnetic to insulating paramagnetic phase, which can be controlled by an applied magnetic field. The insulating phase occurs due to trapping of the charge carriers by polaronic lattice distortions, which raise the resistivity. Theories based on local physics predict that the magnitude of the resistivity j

A collection of 38 articles on Archaeology, Historical Arcaheology, Historical Osteology, History and Art History by authors in Sweden, Denmark and Germany, an introduction and also a bibliography as a tribute to retired reader Anders Ödman at the Department of Archaeology and Ancient History, Lund University.

Context. A key science goal of the Gaia-ESO survey (GES) at the VLT is to use the kinematics of low-mass stars in young clusters and star forming regions to probe their dynamical histories and how they populate the field as they become unbound. The clustering of low-mass stars around the massive Wolf-Rayet binary system gamma(2) Velorum was one of the first GES targets. Aims. We empirically determ

Popular Abstract in Swedish Forskningen har visat Den ökade prevalensen av kronisk hjärtsvikt utgör en enorm utmaning för sjukvården. Trots att vi idag har effektiva medicinska behandlingar vid hjärtsvikt och bra läkemedel så är sjukligheten och dödligheten fortfarande betydande. Hjärtsvikt leder till en förändrad kärlreaktivitet generellt i cirkulationen, dock är betydelsen av denna endast känd The increased prevalence of chronic congestive heart failure (HF) is a tremendous challenge for society. In spite of effective medical treatment for acute HF, better pharmacological treatment for specific neurohormonal intervention and better diagnostic tools, e.g. biomarkers of natriuretic peptides, the morbidity and mortality due to this disease are still prominent. HF leads to vascular dysfunct

Sex hormones, particularly the androgens, are important for the growth of the prostate gland and have been implicated in prostate cancer carcinogenesis, yet the determinants of endogenous steroid hormone levels remain poorly understood. Twin studies suggest a heritable component for circulating concentrations of sex hormones, although epidemiologic evidence linking steroid hormone gene variants to

In some recent papers by the first two authors it was shown that for any algebraic crossed product A, where A(0), the subring in the degree zero component of the grading, is a commutative ring, each non-zero two-sided ideal in A has a non-zero intersection with the commutant C-A(A(0)) of A(0) in A. This result has also been generalized to crystalline graded rings; a more general class of graded ri