Climatic effect of light-absorbing impurities on snow : experimental and field observations

Snow and ice are essential components of the Earth system, modulating the energy budget by reflecting sunlight back into the atmosphere, and through its importance in the hydrological cycle by being a reservoir for fresh water. Light-absorbing impurities (LAI), such as black carbon (BC) and mineral dust (MD), have a unique role in influencing the reflectance of the cryosphere. Deposition of the anthropogenic and natural LAI constituents onto these bright surfaces initiates powerful albedo feedbacks that will accelerate melt. This is important globally, but especially for regions such as the Arctic and the Himalaya. In this thesis, observations from both ambient and laboratory experiments are presented. The overarching research goal has been to better understand the climatic effect of LAI on snow. More specifically, an emphasis has been placed on exploring the process-level interactions between LAI and snow, which will enable better comprehension of LAI affecting the cryosphere. Key findings in this thesis involves the investigations on the horizontal variability of BC concentrations in the surface snow that indicate a larger variability on the order of meter scale at a pristine Arctic site compared to a polluted site nearby a major urban area. In outdoor experiments, where LAI were used to artificially dope natural snow surfaces, the snow albedo was observed to decrease following LAI deposition. The albedo decrease was on the same order as in situ measurements of LAI and albedo conducted elsewhere. As snow melted during the experiment, the snow density was observed to decrease with increasing LAI concentration, while this effect was not observed in non-melting snow. The water retention capacity in melting snow is likely to be decreased by the presence of LAI. Measurements examining the absorption of BC indicate that BC particles in the snow have less absorbing potential compared to BC particles generated in the laboratory. The LAI content of snow pit investigations from two glaciers in the Sunderdhunga valley, northern India, an area not previously examined for LAI, presented high BC and MD content, affecting the radiative balance of the glacier snow. At different points, MD may be greater than BC in absorbing light at the snow surface. A continued monitoring of LAI in the cryosphere, both on the detailed scale explored here, as well as on the larger modelling perspective is needed in order to understand the overall response of the cryosphere to climate change

Contrast-enhanced magnetic resonance angiography.

Contrast-enhanced magnetic resonance angiography (CE-MRA) is a diagnostic method for imaging of vascular structures based on nuclear magnetic resonance. Vascular enhancement is achieved by injection of a contrast medium (CM). Studies were performed using two different types of CM: conventional paramagnetic CM, and a new type of CM based on hyperpolarized (HP) nuclei. The effects of varying CM concentration with time during image acquisition were studied by means of computer simulations using two different models. It was shown that a rapid concentration variation during encoding of the central parts of k-space could result in signal loss and severe image artifacts. The results were confirmed qualitatively with phantom experiments. A postprocessing method was developed to address problems with simultaneous enhancement of arteries and veins in CE-MRA of the lower extremities. The method was based on the difference in flow-induced phase in the two vessel types. Evaluation of the method was performed with flow phantom measurements and with CE-MRA in two volunteers using standard pulse sequences. The flow-induced phase in the vessels of interest was sufficient to distinguish arteries from veins in the superior-inferior direction. Using this method, the venous enhancement could be extinguished. The possibility of using HP nuclei as CM for CE-MRA was evaluated. Signal expressions for a flow of HP CM imaged with a gradient echo sequence were derived. These signal expressions were confirmed in phantom experiments using HP 129Xe dissolved in ethanol. Studies were also performed with a new CM based on HP 13C. The CM had very long relaxation times (T1,in vivo/T2,in vivo≈ 38/1.3 s). The long relaxation times were utilized in imaging with a fully balanced steady-state free precession pulse sequence (trueFISP), where the optimal flip angle was found to be 180°. CE-MRA with the 13C-based CM in rats resulted in images with high vascular SNR (~500). CE-MRA is a useful clinical tool for diagnosing vascular disease. With the development of new contrast media, based on hyperpolarized nuclei for example, there is a potential for further improvement in the signal levels that can be achieved, enabling a standard of imaging of vessels that is not possible today

Minding the pandemic: A CSR perspective on patterns in Muslim religious responses to COVID-19

This article analyses clusters of Muslim responses to the COVID-19 pandemic in a theoretical framework provided by the cognitive science of religion. The responses include theological reflections on the origin, nature, and religious significance of the disease, religious justifications for restrictions on communal worship, apologetics in the light of COVID-19, and how aspects of the COVID-19 pandemic relate to issues of purity, impurity, and contagion. This article places the responses in a wider theoretical context that contributes to explaining their emergence as cultural representations, and, as a consequence, may promote further comparative research into responses to the COVID-19 pandemic in other religious traditions.

Religious education and teaching young people about humanity: Suggesting a new role for RE and for the academic study of religions in Sweden

This article is a suggestion for the rethinking of the role and purpose of religious education (RE) in Swedish public schools, in relation to two major recent reforms: of teachers training (2012) and of syllabi for RE (2011). Based on a notion of the ‘humanistic’ study of religions as he study of religion as a human cultural product, the article argues that a RE – mainly in lower and upper secondary school – informed by contemporary theoretical development, better than any other school subject can cater for the important task of educating young people about who they, as human beings, are and why. To substantiate this claim, the content of the above mentioned reforms are presented, and placed in historical context. Furthermore, the article provides a set of examples of how actual teaching may be structured to fulfil its proposed new task, with a basis in the current syllabi for lower and upper secondary school

The longitudinal biology of depression : PET studies of the dopamine and serotonin systems

The involvement of monoamine neurotransmission in the pathophysiology of depression was established already in the 1960s. However despite an abundance of research, the exact role of the serotonin (5-HT) and dopamine systems in depression have remained elusive. Positron emission tomography (PET) is a nuclear imaging technique that makes the study of the living human brain possible at a molecular level. In this thesis, PET methods were validated (study I) and applied to study aspects of the serotonin and dopamine systems in depression. This was done through patient and control comparisons (study II and III), through examining correlations between key 5-HT proteins (study IV), and through a longitudinal approach testing patients before and after treatments with known efficacy (study II and III). In study I, binding characteristics of the D2 dopamine receptor (D2R) radioligand [11C]raclopride was evaluated in brain regions where D2R density is low (i.e., outside striatum). In most extrastriatal brain regions, little or no decrease in binding was observed after administration of a pharmacological competitor, lending no support for valid quantification. Further, extrastriatal test-retest repeatability was poor. The results indicate that [11C]raclopride PET is not suitable for D2R quantification in extrastriatal brain regions. The aim of study II was to investigate D2R availability in patients with severe depression, compared with healthy controls at baseline and before and after electroconvulsive treatment. Nine patients hospitalized for depression were examined using [11C]raclopride PET before and after a series of electroconvulsive therapy treatments, and nine healthy, matched controls were examined twice. Lower striatal D2R availability was observed in patients compared with controls. No significant change in [11C]raclopride binding was observed in the patient group following treatment. The results suggest that low D2R is associated with severe depression. In Study III, [11C]MADAM PET was used to quantify the 5-HT transporter (5-HTT) in 17 patients with depression before and after treatment with cognitive behavioral therapy. Matched healthy controls were examined once with [11C]MADAM PET. Depression severity decreased and 5-HTT availability increased significantly in patients following the treatment. No significant difference in [11C]MADAM binding was observed between controls and patients at baseline. The results indicate that previous findings of 5-HT dysregulation in patients with depression reflect a temporary state rather than a permanent trait. The aim of study IV was to evaluate the correlation between 5-HTT availability and 5-HT 1B receptor (5-HT1B) availability in the human brain. [11C]MADAM and [11C]AZ10419369 PET was used to quantify 5-HTT and 5-HT1B respectively. 17 healthy individuals were examined with both radioligands. Strong correlations were observed in cortical regions while very weak correlations were observed in most subcortical regions. The results could be indicative of a strong transsynaptic regulation of the 5-HT system in cortical regions. However, the analysis was exploratory and [11C]MADAM signal to noise ratio is poor in cortex so the results should be interpreted with caution

Journal Staff

A life cycle assessment (LCA) of a low energy / passive house in northern Sweden, including building materials and energy use is reported. The case study building is semi detached house for two families situated in Östersund (lat. 63°N), Sweden. Each apartment having a floor space of 160 m2 divided on two floors. The building was constructed during 2010 with a design meeting the requirements for Swedish passive houses as defined by the Forum for energy efficiency buildings (FEBY) and the Swedish center for zero energy houses (SCNH).When it comes to more sustainable buildings, energy use in the build environment has been in focus for some time. The life cycle assessment in this study reveals that the building materials can contribute significantly to environmental burdens of a residential building in northern Sweden. Energy efficiency, efficient use of good building materials and issues of appropriate design need to be discussed in the same context to move toward a more sustainable built environment.For energy efficient buildings in a energy system with renewably based energy carriers, building materials might give rise to a significant or even dominating part of the life cycle impact of a building. This give rise to considerations regarding choices of building materials as well as design of buildings to minimize such impact; while not forgetting social aspects impacted by building design

The role of gender in students’ ratings of teaching quality in computer science and environmental engineering

Students’ ratings of teaching quality on course units in computer science and environmental engineering at a large Swedish university were obtained using the Course Experience Questionnaire; 8,888 sets of ratings were obtained from men and 4,280 sets were obtained from women over ten academic years. There were differences in the ratings given by students taking the two programs; in particular, teachers tended to receive higher ratings in subjects that were less typical for their gender than in subjects that were more typical for their gender. There were differences in the ratings given to male and female teachers, differences in the ratings given by male and female students, and interactions between these two effects. There was no systematic trend for students to give different ratings to teachers of the same gender as themselves compared with teachers of the other gender. Nevertheless, without exception even the statistically significant effects were small in magnitude and unlikely to be of theoretical or practical importance. It is concluded that the causes of differences in the career progression of male and female teachers in engineering education need to be sought elsewhere.   

Brands of athletes- The effect of brand personality of athletes on consumers

Purpose To investigate the effect of an individual celebrity athlete’s personality on the consumer behavior facets of perceived quality and purchase intention. Methodology A quantitative survey with 257 respondents all over the world to deductively test hypotheses. Theories The theoretical foundation of this thesis is the customer-based brand equity theory with a strong emphasis on brand personality. Furtherly used concepts include the consumer behavior facets of perceived quality and purchase intention. Findings Brand personality of athletes affects the perceived quality of their respective product brands. The perceived quality of the product brand positively influence purchase intention

Improving Usability and Efficiency in Warehouse operation, using Smart Glasses

Under senare år har flertalet intressanta personburna produkter, som härstammar ifrån smartphoneteknologin, blivit introducerade på marknaden. En av dessa teknologier som det vuxit ett stort intresse för, men ännu inte fått något kommersiellt genombrott, är smarta glasögon. Då teknologin är så pass ung, så har få aktörer gett sig in på marknaden och användningsområdet har inte hittills nått sin fulla potential och det finns mycket utrymme för förbättring. I detta examensarbete kommer ett specifikt användningsområde undersökas, detta område är lagerarbete. Tidigare inom lagerarbete finns det flera sätt att genomföra ett plock utav varor på; checka av på ett papper, skanna artiklar samt röststyrda lösningar. Consafe Logistics har utvecklat en röststyrd lösning, som går att använda hands-free, vilket frigör händerna så att de exklusivt kan användas till plocket. Deras lösning effektiviserade arbetet och var ungefär dubbelt så snabbt som bekräftelse av plock med skanner. I denna rapport kommer det undersökas om effektiviteten potentiellt kan förbättras ytterligare med hjälp av smarta glasögon och om ett framtida kommersiellt användningsområde finns inom lagerarbete. Fokus ligger också på att undersöka hur ett gränssnitt för smarta glassögon kan implementeras, för att göra det så enkelt som möjligt för användaren att förstå hur produkten ska användas. Därför är också användaren i centrum under hela projektet. Att produkten har stor användbarhet är något som är viktigt om effektiviteten ska kunna ökas. Projektet avslutades med ett proof-of-concept som visade tendenser att om smarta glasögon användes så utfördes arbetet snabbare och användarna kände sig mer säkra på hur arbetet skulle utföras.In recent years, several interesting wearable products which originates from smartphone technology have been introduced on the market. One of these products which has increased in interest, but not yet received a commercial breakthrough, is smart glasses. As the technology is still young and undeveloped, few players have embarked on the market and there is still room for improvement. In this thesis, a specific usage area for smart glasses is explored: namely warehousing. This thesis is focused on the manual pick in a warehouse and how a user can confirm this pick. There are several different tools to help a user with this; confirming on a piece of paper, scan a barcode and voice recognition solutions. Consafe Logistics has developed a voice controlled solution which can be operated hands-free, which makes it possible for a user to use their hands exclusively for handling the pick. With Consafe’s solution, the work was about twice as fast as when using a scanner to confirm a pick. This thesis will examine if the efficiency can be improved further by using smart glasses and if commercial use of smart glasses could have a future in warehousing. A major goal for this thesis was to investigate how to design an interface for smart glasses in order to make a product as usable as possible. Information on how to design an interface for smart glasses is scarce and in order to design a user friendly product, a user centered design process is employed. This thesis resulted in a proof of concept application which showed a tendency that the work proceeded faster and that the user was more confident in their work.Tekniken går framåt i en rasande fart, nya produkter introduceras dagligen och de senaste åren har det varit smarta produkter som det har satsat smycket på. Ända sedan iPhone kom 2007 har denna marknad exploderat och det är nu inte bara telefoner som ska vara smarta. En av dessa produkter som nyligen har börjat göras smarta är glasögon. Tanken bakom smarta glasögon är att du som användare ska kunna få samma information som i telefonen, men istället blir denna presenterad direkt i ditt synfält. Det finns många idéer om användningsområden för denna spännande teknik, men än så länge är det väldigt lite som har blivit satt i praktiken. I ett examensarbete som gjorts på Lunds Tekniska Högskola, har ett av de potentiella användningsområdena undersökts om det skulle finnas en fördel med att tillämpa tekniken. Detta område är lagerlokaler