High-Redshift Starbursting Dwarf Galaxies Revealed by GRB Afterglows

We present a study of 15 long-duration gamma-ray burst (GRB) host galaxies at z>2. The GRBs are selected with available early-time afterglow spectra in order to compare interstellar medium (ISM) absorption-line properties with stellar properties of the host galaxies. In addition to five previously studied hosts, we consider new detections for the host galaxies of GRB050820 and GRB060206 and place 2-sigma upper limits to the luminosities of the remaining unidentified hosts. We examine the nature of the host galaxy population and find that (1) the UV luminosity distribution of GRB host galaxies is consistent with expectations from a UV luminosity weighted random galaxy population with a median luminosity of =0.1 L*; (2) there exists a moderate correlation between UV luminosity and SiII 1526 absorption width, which together with the observed large line widths of W(1526)>1.5 Ang for a large fraction of the objects suggests a galactic outflow driven velocity field in the host galaxies; (3) there is tentative evidence for a trend of declining ISM metallicity with decreasing galaxy luminosity in the star-forming galaxy population at z=2-4; (4) the interstellar UV radiation field is found ~ 35-350 times higher in GRB hosts than the Galactic mean value; and (5) additional galaxies are found at < 2" from the GRB host in all fields with known presence of strong MgII absorbers, but no additional faint galaxies are found at < 2" in fields without strong MgII absorbers. Our study confirms that the GRB host galaxies (with known optical afterglows) are representative of unobscured star-forming galaxies at z>2, and demonstrates that high spatial resolution images are necessary for an accurate identification of GRB host galaxies in the presence of strong intervening absorbers.Comment: 24 emulateapj pages, 24 figures, ApJ in press; full-resolution version available at http://lambda.uchicago.edu/public/tmp/ghost.pd

Damped Lyman Alpha Systems in Galaxy Formation Simulations

We investigate the population of z=3 damped Lyman alpha absorbers (DLAs) in a recent series of high resolution galaxy formation simulations. The simulations are of interest because they form at z=0 some of the most realistic disk galaxies to date. No free parameters are available in our study: these have been fixed by physical and z=0 observational constraints, and thus our study provides a genuine consistency test. The precise role of DLAs in galaxy formation remains in debate, but they provide a number of strong constraints on the nature of our simulated bound systems at z=3 because of their coupled information on neutral H I densities, kinematics, metallicity and estimates of star formation activity. Our results, without any parameter-tuning, closely match the observed incidence rate and column density distributions of DLAs. Our simulations are the first to reproduce the distribution of metallicities (with a median of Z_{DLA} = Z_{solar}/20) without invoking observationally unsupported mechanisms such as dust biasing. This is especially encouraging given that these simulations have previously been shown to have a realistic 0<z<2 stellar mass-metallicity relation. Additionally, we see a strong positive correlation between sightline metallicity and low-ion velocity width, the normalization and slope of which comes close to matching recent observational results. However, we somewhat underestimate the number of observed high velocity width systems; the severity of this disagreement is comparable to other recent DLA focused studies. By z=0 the majority of the z=3 neutral gas forming the DLAs has been converted into stars, in agreement with rough physical expectations. [Abridged]Comment: 24 pages, 18 figures, MNRAS in press. Minor update with a few added details and typographical/grammatical fixes. Movie at http://www.ast.cam.ac.uk/~app26

The processing and impact of dissolved riverine nitrogen in the Arctic Ocean

© The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estuaries and Coasts 35 (2012): 401-415, doi:10.1007/s12237-011-9417-3.Although the Arctic Ocean is the most riverine-influenced of all of the world’s oceans, the importance of terrigenous nutrients in this environment is poorly understood. This study couples estimates of circumpolar riverine nutrient fluxes from the PARTNERS (Pan-Arctic River Transport of Nutrients, Organic Matter, and Suspended Sediments) Project with a regionally configured version of the MIT general circulation model to develop estimates of the distribution and availability of dissolved riverine N in the Arctic Ocean, assess its importance for primary production, and compare these estimates to potential bacterial production fueled by riverine C. Because riverine dissolved organic nitrogen is remineralized slowly, riverine N is available for uptake well into the open ocean. Despite this, we estimate that even when recycling is considered, riverine N may support 0.5–1.5 Tmol C year−1 of primary production, a small proportion of total Arctic Ocean photosynthesis. Rapid uptake of dissolved inorganic nitrogen coupled with relatively high rates of dissolved organic nitrogen regeneration in N-limited nearshore regions, however, leads to potential localized rates of riverine-supported photosynthesis that represent a substantial proportion of nearshore production.Funding for this work was provided through NSFOPP- 0229302 and NSF-OPP-0732985.Support to SET was additionally provided by an NSERC Postdoctoral Fellowship

Late quaternary sea-ice and sedimentary redox conditions in the eastern Bering Sea – Implications for ventilation of the mid-depth North Pacific and an Atlantic-Pacific seesaw mechanism

On glacial-interglacial and millennial timescales, sea ice is an important player in the circulation and primary productivity of high latitude oceans, affecting regional and global biogeochemical cycling. In the modern North Pacific, brine rejection during sea-ice freezing in the Sea of Okhotsk drives the formation of North Pacific Intermediate Water (NPIW) that ventilates the North Pacific Ocean at 300 m to 1000 m water depth. Glacial intervals of the late Quaternary, however, experienced a deepening of glacial NPIW to at least 2000 m, with the strongest ventilation observed during cold stadial conditions of the last deglaciation. However, the origin of the shifts in NPIW ventilation is poorly understood. Numerical simulations suggest an atmospheric teleconnection between the North Atlantic and the North Pacific, in response to a slowdown or shutdown of the Atlantic meridional overturning circulation. This leads to a build-up of salinity in the North Pacific surface ocean, triggering deep ventilation. Alternatively, increased sea-ice formation in the North Pacific and its marginal seas may have caused strengthened overturning in response to enhanced brine rejection. Here we use a multi-proxy approach to explore sea-ice dynamics, sedimentary redox chemistry, and benthic ecology at Integrated Ocean Drilling Program Site U1343 in the eastern Bering Sea across the last 40 ka. Our results suggest that brine rejection from enhanced sea-ice formation during early Heinrich Stadial 1 locally weakened the halocline, aiding in the initiation of deep overturning. Additionally, deglacial sea-ice retreat likely contributed to increased primary productivity and expansion of mid-depth hypoxia at Site U1343 during interstadials, confirming a vital role of sea ice in the deglacial North Pacific carbon cycle

Outcome Measures of Functioning and Physical Activity in Patients with Low Back Pain - Exemplified in Patients Who Undergo Lumbar Fusion Surgery

INTRODUCTION: Chronic low back pain (LBP) can negatively affect health in terms of disability and decreased levels of functioning and physical activity. Chronic LBP due to degenerative disc disease (DDD) is a subgroup of LBP for which lumbar fusion surgery (LFS) is a treatment option. LFS is usually evaluated with patient-reported outcome measures (PROMs) of disability, but physical capacity tasks measuring functioning and accelerometers measuring physical activity can complement the use of PROMs to better understand patients’ health. AIM: To investigate aspects of the measurement of functioning and physical activity in patients with LBP. METHODS: In Study I, articles on physical capacity tasks for patients with LBP were systematically identified and the level of evidence for the reliability, validity, and responsiveness of the tasks was determined. Studies II‒IV included patients with chronic LBP due to DDD scheduled for LFS. In Study II, the responsiveness and minimal important change of four physical capacity tasks were investigated with hypothesis testing and the optimal cutoff point method. In Study III, patients’ preoperative level of physical activity was studied with accelerometers. Associations with potential barriers to physical activity were investigated with regression analysis. In Study IV, preoperative predictors of the patients’ levels of physical activity and disability six months after surgery were investigated with regression analysis. RESULTS: Five-repetition sit-to-stand, five-minute walk, 50-foot walk, progressive isoinertial lifting evaluation, and timed up-and-go demonstrated the best evidence for reliability and validity for patients with chronic LBP (Study I). Of these, five-repetition sit-to-stand also showed adequate responsiveness. One-minute stair climbing demonstrated adequate results for both reliability and responsiveness. In Studies II–IV, 118 patients with chronic LBP due to DDD were included. Fifty- foot walk, timed up-and-go, and one-minute stair climbing demonstrated adequate responsiveness while 5-minute walk did not (Study II). Ninety-eight patients did not fulfill the WHO recommendations on physical activity, of whom 32 did not accumulate a single minute of the required 150 minutes per week of physical activity. Moreover, high levels of fear of movement and disability were associated with a low preoperative level of physical activity (Study III). A low preoperative level of physical activity and a high preoperative level of self-efficacy for exercise were predictors of a larger increase in the postoperative physical activity. A high preoperative level of disability and low preoperative levels of pain catastrophizing and self-efficacy for exercise were predictors of a more favorable outcome for disability (Study IV). CONCLUSIONS: Fifty-foot walk and timed up-and-go showed adequate results for reliability, validity,  and responsiveness and are recommended for assessment of functioning in patients with chronic LBP due to DDD undergoing LFS. Future pre- and postoperative interventions targeting fear of movement and disability might increase the level of physical activity in physically-inactive patients. The prediction model of physical activity could possibly be used in clinical practice to predict  which patients are in need of extra pre- and postoperative interventions to increase their level of physical activity.

Från industrier till upplevelser : en studie av symbolisk och materiell omvandling i Bergslagen

In old industrial regions traces from historical mining and production of iron and steel have become a valuable resource in developing a tourism industry and other experience-oriented industries in the post-industrial society. The so called Experience Industry became a buzz-word in regional development programs during the 2000´s. The region of Bergslagen in the middle of Sweden is a good example of this structural change in economy which has been going on since the crisis of the steel industry in the middle of the 1970´s. In the 1980’s, the region was seen as one of the most depressed areas in Sweden, together with the sparsely populated north. Because of that, cultural heritage has been promoted to strengthen regional identity in Bergslagen. Strengthening regional identity is still a matter in regional development in the region, but today efforts are more concentrated on commercial use and packaging of heritage as experience in order to create an attractive image of Bergslagen. Statistical data shows that the regional labour market is changing. During the 1990s and early 2000s employment in the Experience Economy in Bergslagen has increased by almost 30 percent. The emerging labour force is in many ways different from the traditional patterns on the regional labour market. Traditionally marginalized group, such as women, young people and immigrants are well represented. But they are often low educated, low paid and part-time employed. On the other hand we also find a growing well educated and well paid group of employees. They are often in-migrants or commuters from places outside the region. Campaigns to promote Experience Industries on the local level are common in many places in the region. Local campaigns tend to focus on tourism and the commercial use of the typical industrial heritage associated with Bergslagen. However, the regional identity is often considered a problem due to the negative image of Bergslagen which where formed after the crisis for the steel industry. Although there is a tendency towards a more positive approach to Bergslagen, developers and politicians often still claim that they rather use other local and regional identities in place marketing than being a place in Bergslagen

Group counseling - a way to ignite hope and motivation : A qualitative study at Study-motivating folk high school course

På Studiemotiverande folkhögskolekurs (SMF) går individer som är arbetslösa och behöver förberedas samt finna motivation till att påbörja eller återuppta reguljära studier, varav gruppvägledning utgör en väsentlig del av arbetet. Hur gruppvägledning effektivt kan utövas är dock beroende av ett flertal centrala faktorer och forskning visar att det finns en otillräcklig förståelse för arbetssättets positiva fördelar samt ett lågt själv­förtroende bland vägledare i utövandet. Utifrån detta dilemma undersöker studien vad de centrala faktorerna är i syfte att effektivt utöva gruppvägledning samt hur arbetssättet upplevs stärka deltagarna till fortsatta studier. En kvalitativ undersökning med sju geografiskt spridda folkhögskolor i Sverige har genomförts. Tidigare forskning på området ligger till grund för analysen, samt de tre teorierna Mattering Climate, Self-Determination Theory och Hope-Action Theory. I resultatet framkom följande centrala faktorer för ett effektivt utövande av gruppvägledning; relationsskapande, bekräftelse av deltagarna, sammanhållning, samt gruppvägledande aktiviteter som studiebesök och ta del av andras och sin egna berättelse. Bland de främsta effekterna sågs  stärkt självkänsla, självkännedom, motivation, arbetsmarknadskunskap, visionering av framtida karriär­vägar, samt en känsla av hopp som den röda tråden. Gruppvägledning kan utifrån studien stödja en målgrupp som tappat motivationen och behöver utveckla ett utforskande förhållnings­sätt gentemot övergången till reguljära studier.

Brand equity har betydelse i byggbranschen : En studie om köpbeslutsprocessen, brand equity och beslutspåverkande roller

I denna studie studeras brand equity och dess påverkan på köpbeslutsprocessen. Hur påverkar brand equity köpare? Vilka steg i köpbeslutsprocessen påverkas? Genom att studera detta kan säljande företag få en ökad förståelse för hur köpare resonerar vid inköp, vilket kan användas när de ska utforma effektivare säljstrategier. Dessutom kommer beslutspåverkande roller att studeras för att resultatet ska bli mer praktiskt applicerbart då det ofta är flera individer som är inblandande när företag ska genomföra inköp.Studien har en kvalitativ ansats med semistrukturerade intervjuer som grund för att studera vilken betydelse varumärken har under köpbeslutsprocessen i byggbranschen. Intervjuerna har genomförts med sju individer som är ansvarig eller haft en stor roll vid inköp av maskindrivna handverktyg på sina företag.Det resultat som studien kommer fram till påvisar att brand equity har betydelse. Ju starkare ett varumärkes brand equity är desto mer påverkan har det på köpbeslutsprocessen. Detta får till följd att varumärken med starkare brand equity blir favoriserade och effektiviserar köpbeslutsprocessen eftersom att köpare tenderar att sålla bort varumärken med svag brand equity. Köpare gör en mindre omfattande köpbeslutsprocess då de väljer att utvärdera färre varumärken. Med varumärken som har ett starkt brand equity upplever dessutom köpare att det finns mindre risk att göra felköp. Säljande företag bör på grund av studiens resultat arbeta aktivt med att förbättra brand equity för sina varumärken. Förutom det praktiska bidraget att studien kan användas för att förbättra säljstrategier kommer studien ge ökad förståelse för brand equity i B2B

Bränsleförbrukning i ett åkeri : En studie av åkeriers verksamhet avseende bränsleförbrukning &amp; CO2-utsläpp

Bakgrund &amp; Problem: Transport och distribution utgör grundläggande aktiviteter i ett transportföretag, såsom en 3PL-aktörs, verksamhet. I denna verksamhet är tunga transporter vanligt förekommande vilket utgör en betydande del av världens totala koldioxidutsläpp. Samtidigt som bränsleförbrukning står för en stor del av ett åkeris totala kostnader driver det även CO2-utsläpp i en redan, sett ur ett miljömässigt perspektiv, ansträngd värld. Att på sikt reducera dem globala CO2-utsläppen kommer kräva en omställning av transportsektorn och en övergång från fossila bränslen till mer förnyelsebara. För det enskilda åkeriet kan minskad bränsleförbrukning sänka kostnaderna samtidigt som det är fördelaktigt för miljön då det leder till minskade CO2-utsläpp. Vad driver då bränsleförbrukningen i ett åkeri? I denna studie ligger fokus främst på sparsam körning, transportplanering och teknologi som de faktorer som påverkar bränsleförbrukningen. I sammanhanget är även val av bränsle relevant men denna faktor har analyserats separat då det snarare är en faktor som driver CO2-utsläpp än bränsleförbrukningen i sig. Syfte: Syftet med denna studie är att studera ett urval av transportföretaget GDL:s åkerier och dess verksamhet med primärt fokus på bränsleförbrukning och CO2-utsläpp. Ambitionen vid arbetets slut är att kunna betygsätta åkeriernas verksamhet med utgångspunkt i deras bränsleförbrukning och de faktorer som driver den. Studien syftar även till att klargöra maktförhållandet mellan uppdragsgivare, som GDL, och åkerier. Metod: Studien tillämpar ett positivistiskt vetenskapligt synsätt med abduktion som angreppssätt. Baserat på de frågeställningar som studeras i detta arbete har en kvalitativ forskningsmetod applicerats överlag med små inslag av kvantitativa aspekter. Slutsats: De faktorer som huvudsakligen driver bränsleförbrukning är sparsam körning, transportplanering och teknologi. Sparsam körning är den faktor som denna studie bedömer ha störst påverkan och en fullständig implementering kan resultera i en bränslereduktion på 10-30 5(95) procent. Förutom mängden bränsle som förbrukas har även val av bränsle möjligheten att påverka företag positivt, främst miljömässigt men även ekonomiskt, där alternativa bränslen är huvudsakligt fokus. I denna studie hanteras bränslen som är förekommande inom studiens åkerier och bland dessa har HVO klart lägst CO2-utsläpp. Inflytandet från större aktörer, som GDL, är i nuläget svårt att precisera och varierar mellan åkerier. GDL:s position på marknaden borde, om så önskas, möjliggöra att ett större inflytande utövas gentemot de mindre aktörer som till stor del kör åt GDL.Background &amp; Problem: Transportation and distribution, such as 3PL, pose an essential part of a logistics company’s scope of duties; especially heavy transports, which account for a big part of the worldwide CO2-emissions, are an essential part of the business. Whilst fuel consumption makes up the majority of a company’s total consecutive expenses, it also augments carbon dioxide emission in our already flawed world. Therefore, the aim in the long run is a readjustment in the transport sector which includes the transition from fossil fuels towards renewable energy sources as well as the reduction of fuel consumption in general. This is also in the interest of the distribution companies, as they thereby can save expenses and reduce their ecological footprint at the same time. Yet, what determines the fuel consumption of a distribution company? To decry that, this study will primarily focus on eco-driving, route planning as well as technology as the main drivers of fuel consumption. It hereby is necessary to consider the chosen kind of fuel as an important factor regarding the CO2-emissions; this, however, will be analyzed separately. Purpose: The purpose of this paper is to study a selection distribution companies that primarily work on behalf of GDL, to examine which factors drive fuel consumption and CO2 emissions 6(95) within these companies. This papers ambition is to fairly evaluate the distribution companies and grade them accordingly, based on factors that drive fuel consumption and CO2 emissions. Additionally, this paper also aims to clarify the power structure between outsourcers, such as GDL, and their distributors. Method: This paper applies a positivistic scientific view with abduction as an approach. Based on this papers research questions it was determined that a qualitative research method should be applied throughout the study, with minor quantitative elements. Conclusions: The main factors for fuel consumption are parsimonious driving, route planning as well as technology. Hereby, frugal driving was ranked as the most important one as it can lead to a saving of 10-30 percent. Furthermore, the amount of used fuel can be positively influenced through the choice of certain fuel types. This has economical as well as ecological effects; the study focusses on renewable fuels, such as HVO, which has by far the lowest CO2- emissions amongst the fuels that were drawn into consideration. Influence by bigger actors, such as GDL, makes it hard to determine between different companies’ standings, as GDL’s position directly influences their smaller distributers