Measurement of the Multi-TeV Neutrino Interaction Cross-Section with IceCube Using Earth Absorption

Neutrinos interact only very weakly, so they are extremely penetrating. The theoretical neutrino–nucleon interaction cross-section, however, increases with increasing neutrino energy, and neutrinos with energies above 40 teraelectronvolts (TeV) are expected to be absorbed as they pass through the Earth. Experimentally, the cross-section has been determined only at the relatively low energies (below 0.4 TeV) that are available at neutrino beams from accelerators1,2. Here we report a measurement of neutrino absorption by the Earth using a sample of 10,784 energetic upward-going neutrino-induced muons. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the neutrino–nucleon interaction cross-section for neutrino energies 6.3–980 TeV, more than an order of magnitude higher than previous measurements. The measured cross-section is about 1.3 times the prediction of the standard model3, consistent with the expectations for charged- and neutral-current interactions. We do not observe a large increase in the cross-section with neutrino energy, in contrast with the predictions of some theoretical models, including those invoking more compact spatial dimensions4 or the production of leptoquarks5. This cross-section measurement can be used to set limits on the existence of some hypothesized beyond-standard-model particles, including leptoquarks

Neighbourhood choice and neighbourhood reproduction

Although we know a lot about why households choose certain dwellings, we know relatively little about the mechanisms behind their choice of neighbourhood. Most studies of neighbourhood choice focus only on one or two dimensions of neighbourhoods: typically poverty and ethnicity. In this paper we argue that neighbourhoods have multiple dimensions and that models of neighbourhood choice should take these dimensions into account. We propose the use of a conditional logit model. From this approach we can gain insight into the interaction between individual and neighbourhood characteristics which lead to the choice of a particular neighbourhood over alternative destinations. We use Swedish register data to model neighbourhood choice for all households which moved in the city of Uppsala between 1997 and 2006. Our results show that neighbourhood sorting is a highly structured process where households are very likely to choose neighbourhoods where the neighbourhood population matches their own characteristics. We find that income is the most important driver of the sorting process, although ethnicity and other demographic and socioeconomic characteristics play important roles as well.PostprintPeer reviewe

Interactions between dietary chicory, gut microbiota and immune responses

This thesis provides a better understanding of interactions between diet, gut microbiota, and immune responses to a specific dietary fiber source, chicory (Cichorium intybus L). This was achieved by examining the impact of chicory fiber on animal performance, digestibility, gut development, commensal bacteria community structure in small and large intestine, and follow-up reactions with specific immune components, cytoprotective heat shock protein (HSP) 27 and 72, in vivo and in vitro. The impacts of dietary chicory on nutrient utilization, performance, and gut environment and morphology were investigated in chickens and young pigs. One-day-old chicks were fed cereal-based diets with inclusion of 60 or 120 g/kg chicory forage and/or root, with each forage diet derived from two harvests. Growing pigs were fed diets without and with inclusion of 80 or 160 g/kg chicory forage and/or root. The results showed that chicory inclusion maintained good animal performance and was accompanied by changes in gut morphology. Total tract apparent digestibility of non-starch polysaccharides (NSP) and uronic acid in broilers decreased with inclusion of 120 g/kg chicory, but not with inclusion of 60 g/kg. This indicates that chicory can be used as a palatable fiber source for broiler chickens and young pigs. Gut microbiota complexity and dietary NSP-induced changes in pigs were examined using terminal restriction fragment length polymorphism (T-RFLP). The analysis revealed four primary microbiota clusters: luminal and mucosal ileal microbiota and luminal and mucosal colonic microbiota. In the ileum, lactic acid bacteria (LAB) were dominant and responsive to inulin-type fructan. In the colon, bacteria belonging to clostridial cluster IV and XIVa responded to chicory pectin, whereas Prevotella was related to cereal xylan. Mapping of cytoprotective HSP27 and HSP72 occurrence in porcine gut revealed region- and cell type-specific features. Physiological expression of HSP72 was correlated with LAB, representing an important interplay between HSPs and commensal microbes. In-depth studies of interactions between lactobacilli and gut mucosa and their effects on barrier function and HSP expression revealed protective effects from lactobacilli by enhancing HSP and tight junction protein expression under pathogen challenge

Macronutrient cycling in surface waters

The levels and relative proportions of macronutrients set the conditions for life in surface waters. Man-made disturbances to macronutrient cycling have caused environmental problems such as eutrophication, acidification and global change. In this thesis, macronutrient cycling was studied by performing spatial and temporal large-scale studies of aquatic, terrestrial and atmospheric national monitoring data. Trophic status was found to have a profound impact on nitrate-nitrogen (NO₃-N) concentrations in surface waters. Lakes and streams of the same trophic status displayed opposite NO₃-N patterns. These findings are of great importance when dealing with environmental assessment on the landscape scale, and an awareness of these patterns may also facilitate the design of sampling programs. Trophic status also seems important for trends in total phosphorus (TP) and total organic carbon (TOC) concentrations in boreal and alpine catchments. A temporal study of TP and TOC concentrations showed decreases in nutrient-poor catchments and increases in more nutrient-rich surface waters. Different responses of terrestrial organic matter production and decomposition to temperature increases may be responsible for the observed patterns. Consequently, continued global warming may lead to a stronger polarization between the nutrient-poor northern and the more nutrient-rich southern catchments. Further studies showed that nutrient conditions in soils and surface waters were strongly affected by atmospheric deposition. By using large data-sets on nutrient content in soils and nutrient concentrations in lakes, it was found that carbon to nitrogen ratios (C:N) in the organic soil layer and in lakes increased from the southern to the northern parts of Sweden, resulting in a strong relationship between soil and lake water C:N. The strong relationship was primarily due to the high correlation between nitrogen (N) in organic soil layer and lake N. Large-scale variations in soil C content were not strongly linked to lake C concentrations whereas soil N seemed to leach in the form of NO₃-N to lakes. By calculating catchment soil, lake and river mouth C stocks, it was estimated that about 10 % of Sweden's total terrestrial net ecosystem production is transported through lakes annually. This indicates that the amount of C exported from soils is substantial and that boreal soils maybe less important as a C sink as previously thought. Furthermore, it was found that the colored portion of C was selectively lost and that the decrease in water color was dependent on water retention time. This implies that under conditions predicted in future climate scenarios of increased precipitation, water reaching the seas will be more colored than today. The results from this thesis highlight the importance of atmospheric N deposition and trophic status to macronutrient cycling in both terrestrial and aquatic ecosystems

Online behavior from desktop and mobile devices are connected

Cell phones and other mobile devices are used to access the Internet even at home and at work where computers are easily available. They are no longer a mere backup to the computer. This means that it makes little sense to study Internet access from mobile devices separate from other Internet access. We need new methods that encompass online behavior from desktop computers and mobile devices as well as stationary and mobile online behavior

A Clash between the Business and Political Climates in Sweden - Gender in the European Structural Fund Partnerships

In this paper we highlight and discuss a Swedish equality paradox in two different spheres: entrepreneurship and politics. We focus on the EU Structural Funds and women entrepreneurs' access to resources through the European Regional Development Fund (ERDF). Combining human geography and political science, we draw upon network and partnership theory posing questions concerning the room for manoeuvre for women entrepreneurs to gain access to relevant networks, to create new networks in order to establish relations with EU related partnerships, and to gain access to the process of allocating EU structural fund financial resources

The Rise in Female Employment and the Role of Tax Incentives - An Empirical Analysis of the Swedish Individual Tax Reform of 1971

Sweden reached the 2007 OECD average level of female labor force participation already in 1974. Before, but not after, 1971 the average tax rate facing the housewife was a function of the income of her husband. By exploiting a rich register based data source I utilize the exogenous variation provided by the individual tax reform to analyze the evolution of female employment in Sweden in the beginning of the 1970’s. Simulations suggest that employment among married women would have been 10 percentage points lower in 1975 if the 1969 statutory income tax system still had been in place in 1975.female labor supply, income tax reforms

Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

Using Computer Vision Technologies to Make the Virtual Visible

Mobile Life CentreMobile 2.