| 1. |
- Geijer Lundin, Erik, 1976-
(författare)
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Uplink Load in CDMA Cellular Radio Systems
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The uplink of code division multiple access (CDMA) cellular radio systems is often interference limited. The interference originates from many users whose transmission powers are not observable for the system. This thesis introduces uplink load and applies means of explicitly considering the users’ radio environment when approximating and controlling the load.A desirable property of all cellular radio systems is uplink feasibility, i.e., existence of finite user transmission powers to support the allocated services. Uplink load can be considered as a measure of how far from infeasibility the system is. The performed characterization of uplink load lead to two concrete definitions related to the amount of received and transmitted power, respectively.An important part of the total load is the intercell load which is caused by users connected to neighboring base stations. If not carefully handled, the intercell load can jeopardize uplink feasibility. Conversely, knowledge of a lower intercell load can be used to increase the resource assignments. A common denominator in all the work in this thesis is that the intercell load is explicitly considered.When approximating uplink load, a centralized approach is adopted to study information gathered in several base stations. This yields good approximations of the average load. However, centralized approximations can not detect momentarily peaks in the load. A number of resource allocation algorithms making control decisions in the local base stations are proposed based on experience from characterizing uplink load. As the algorithms study the intercell load, yet without measuring the interference power, they are robust in the sense that they will never assign resources yielding an infeasible system.A straightforward way of controlling the uplink load is to use measurements of the received interference power. This approach, just as the proposed load approximations, can gain from knowing the background noise power. The same framework used for designing robust resource allocation algorithms, is also used for estimating the background noise power.
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| 2. |
- Lundin, Anette
(författare)
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Rättfärdigade prioriteringar : en kvalitativ analys av hur personal i äldreomsorgen hanterar motstridiga verksamhetslogiker
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation aims at contributing to social scientific knowledge about prevailing prioritizations in eldercarepractice by looking at an economic and a caring logic, and how these logics are overlapping, contradictory or comein conflict with each other. A more concrete aim is to understand how the personnel describe their work with orfor balance between the logics and their justifications prioritizations made in the care of older persons. The researchquestion is: How do personnel and care unit manager at a public nursing home understand and handle the twologics that govern care work for facilitating wellbeing of the residents. The aim and research question led to threesub-aims: 1) to analyze the personnel’s experiences of and meaning making about the care work they carry out, 2)to illuminate and problematize the two logics above, and 3)to analyze how the personnel justify their prioritizationsin prevailing context, and how their accountability have an effect on their professional identities.Empirical material was gathered through 13 individual interviews with care personnel and their care unitmanager at a public nursing home in Sweden. These interviews were complemented by a group interview. Thematerial was analyzed by the use of three methods: phenomenology (Paper I and II), reflexive analysis (Paper III),and a positioning analysis (Paper IV). Paper I found that the personnel understands the residents’ well-being asbeing characterized by feeling of being existentially touched. This essence is constituted by feeling freedom ofchoice, pleasure, and closeness to someone or something. In Paper II, the work for facilitating this kind of wellbeingwas characterized by three ambiguities: (i) freedom of choice for the older persons vs. institutionalconstraints, (ii) the residents' need for activation vs. wanting not to be activated, and (iii) the residents' need forroutine vs. the eldercarers' not being able to know what the residents need. Paper III showed that the care unitmanager created a hybrid of the two logics (economy is care and vice versa) and that the personnel oppose thishybrid. The opposition is shaped as the personnel divides their work in care and “those other things”. Thesefindings showed how interaction between the logics expresses itself in practice and that it is the personnel who hasto handle contradictions between the logics in their everyday care work. The positioning analysis in Paper IV hadthree levels. The first level showed how the carers align with their peers and that they find the organizationalframe, within which they have agency, changed due to increased workload. This change led to an order of priorities.The second level showed that the carers relate to three aspects when making accounts: the care itself, the olderpersons, and the media. The third level showed that the carers share a view of administration, cleaning, servingmeals, and filling up supplies, as not being parts of caring.The dissertation’s theoretical framework focused on theories on logics, accountability, and professionalidentity. The conclusion is that both logics are needed in order to facilitate the well-being of the older persons. Therelationships between the two logics are not always clear and if their contradictions are not illuminated, there is arisk for a care practice that does not facilitate the well-being of their residents. An important theoreticalcontribution is that logics of activities should be understood vertically (form political, through management, anddown to the level of practice) instead of horizontally. The practical implications emphasize the importance ofsupporting the personnel’s professional identity on the one hand, and discussing the logics on the other. Byunderstanding differences between definitions on management-level and practice level, a homogeneity can bereached.
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| 3. |
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| 4. |
- Lundin, Erik
(författare)
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Evolution of New Genes and Functions
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- To answer major evolutionary questions, we need a better understanding of the effects of mutations on specific functions and organism fitness. The aim of this thesis was to elucidate how new functions evolve and potential trade-offs with the original function.Paper I identified a bimodal distribution of fitness effects of mutations in Salmonella enterica HisA protein. Most mutations negatively affected protein function but the effect was masked at high gene expression. Expression levels and the extent to which the studied protein limited growth were important in determining the fitness effects of mutations. No fitness prediction tool was satisfactorily alone but in combination predictions were improved.In Paper II, S. enterica HisA was evolved to acquire TrpF activity. Numerous pathways towards improved TrpF activity were examined and several improvement mechanisms were identified. Improved TrpF activity extensively reduced the original activity, generalist enzymes were rare and restoring original activity after an initial loss was difficult. Furthermore, expression levels had a major impact on the shape of the trade-off curve.In Paper III, adaptation during serial passage of Escherichia coli and S. enterica under laboratory conditions were examined. Adaptive mutations were identified in four different laboratory media and their fitness effects were determined. Little overlap in mutation spectra was found in the different media and species suggesting that adaptation was media-specific. Furthermore, media adaptation mutations reduced the accuracy of fitness assays and the use of pre-adapted strains improved the sensitivity of fitness assays 10-fold.Paper IV examined evolution of novel metabolic capabilities in S. enterica by analyzing growth on 124 non-native carbon sources. Growth was observed on 25 compounds and for five of these, the causative mutation was identified. Increased gene expression of cryptic genes was a major mechanism for acquiring the novel phenotypes.In conclusion, my results show that in most cases many types of mutations can improve a function and allow adaptive evolution but this often is associated with a trade-off and loss in other abilities. Increased gene expression was a major mechanism by which bacteria could compensate for loss of an activity as well as acquire new metabolic capabilities.
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| 5. |
- Lundin, Erik, 1963-
(författare)
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Slow Transit Constipation : Aspects of Diagnosis and Treatment
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Oral 111-Indium-DTPA colonic scintigraphy was used to assess segmental transit in 23 patients with slow transit constipation (STC) and 13 controls. The transit time did not differ between patients and controls in the right colon, whereas the patients had a consistent delay from the transverse colon and distally (P<0.05–0.001). Two individual patients had a delay in the right colon.Twenty-eight patients underwent a left- (n=26) or a right (n=2) hemicolectomy for STC, after evaluation including colonic scintigraphy. Twenty-three patients (80%) were satisfied with the outcome after a median of 50 months. The median stool frequency increased from one to seven per week (P<0.001). The number of patients with bloating, excessive straining and painful defecation decreased (P<0.05). The laxative use decreased (P<0.01) and faecal continence was unchanged. A blunted rectal sensation correlated to a poor outcome.Fifty constipated patients with slow colonic transit and 28 controls were investigated with anorectal manovolumetry. Anal resting pressure was lower (P<0.05), and squeeze pressure tended to be lower (P=0.09) in patients. Rectal sensation was not different between groups, although ten patients had a threshold for filling sensation above the 95th percentile of controls. The rectal compliance was increased in patients (P<0.05–0.01).Total and segmental colonic transit was assessed with radio-opaque marker study and scintigraphy in 35 constipated patients, and related to normal values. Twenty-seven of 31 female patients had a prolonged total transit time on marker study, and 26 on scintigraphy. Of those 31 patients, 29 had prolonged segmental transit only in one or two segments on marker study. The two methods gave a similar result, except in the descending colon (P<0.05). However, the results varied considerably for individual patients.In conclusion, patients with STC often benefit from a segmental colonic resection, following assessment including scintigraphy. Anorectal physiology testing may predict surgical results.
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| 6. |
- Lundin, Erik, 1982-
(författare)
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The role of inland waters in the carbon cycle at high latitudes
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Understanding the drivers of climate change requires knowledge about the global carbon (C) cycle. Although inland waters play an important role in the C cycle by emitting and burying C, streams and lakes are in general overlooked in bottom-up approached C budgets. In this thesis I estimated emissions of carbon dioxide (CO2) and methane (CH4) from all lakes and streams in a 15 km2 subarctic catchment in northern Sweden, and put it in relation to the total catchment C exchange. I show that high-latitude aquatic systems in general and streams in particular are hotspots for C emission to the atmosphere. Annually, the aquatic systems surveyed in this study emitted about 10.8 ± 4.9 g C m-2 yr-1 (ca. 98 % as CO2) which is more than double the amount of the C laterally exported from the catchment. Although the streams only covered about 4% of the total aquatic area they emitted ca. 95% of the total aquatic C emission. For lake emissions, the ice break-ups were the most important annual events, counting for ca. 45% of the emissions. Overall, streams dominated the aquatic CO2 emission in the catchment while lakes dominated CH4 emission, 96 % and 62 % of the totals, respectively. When summing terrestrial and aquatic C fluxes together it showed that the aquatic emissions alone account for approximately two thirds of the total annual catchment C loss. The consequence of not including inland waters in bottom-up derived C budgets is therefore a risk of overestimating the sink capacity of the subarctic landscape. However, aquatic systems can also act as C sinks, by accumulating C in sediment and thereby storing C over geological time frames. Sediment C burial rates were estimated in six lakes from a chronology based on 210Pb dating of multiple sediment cores. The burial rate ranged between 5 - 25 g C m-2 yr-1, which is of the same magnitude as lake C emissions. I show that the emission:burial ratio is about ten times higher in boreal compared to in subarctic-arctic lakes. These results indicate that the balance between lakes C emission and burial is both directly and indirectly dependent on climate. This process will likely result in a future increase of C emissions from high-latitude lakes, while the C burial capacity of these same lakes sediments weaken.
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| 7. |
- Stecksén, Anna, 1982-
(författare)
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Stroke thrombolysis on equal terms? : implementation and ADL outcome
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Stroke thrombolysis is a method for restoring cerebral blood flow after ischemic stroke, with high priority in the Swedish national guidelines. implementation of stroke thrombolysis in Swedish routine stroke care has shown marked differences between demographic groups, hospital types, and regions. The general aim of this thesis were to examine the implementation of ischemic stroke thrombolysis in Swedish routine stroke care with an equity perspective; to gain more insight into the factors that influence implementation, how the treatment has reached patient groups, and differences in long-term outcomes between women and men. Analysis of data from research interviews with clinicians working within stroke care displayed that the facilitators of and barriers to the implementation of stroke thrombolysis could broadly be categorized into those related to individuals, to social interactions and context, and to organizational and resource issues. Key facilitating factors expressed in interviews were work pride and motivation, good leadership, involvement of all staff members in the implementation process, and quality assurance. Major barriers concerned lack of competence and experience, outdated attitudes regarding stroke management, counterproductive power structures, lack of continuity, and insufficient human resources. National quality register data displayed that stroke thrombolysis treatment expanded to reach more patients with mild deficits. Groups with higher education were more likely to receive treatment, compared to groups with lower educational level. These education group differences have, however, decreased over time in relative terms, but not in absolute terms. Further, there were considerable between-hospitals differences in treatment rates for patients with milder deficits, associated with hospital’s overall stroke thrombolysis rates. Moreover, larger non-university hospitals displayed treatment rate differences between educational groups that were not attributable to patient characteristics. Among thrombolysis-treated women and men, that was independent in ADL before their stroke and survived the first year post-stroke, women experienced higher probability to be dependent in ADL at both 3 and 12 months post-stroke, compared to men. This difference remained significant despite comprehensive adjustments for individual characteristics, symptom severity, and acute effects from stroke thrombolysis.This thesis displays that clinicians face barriers and facilitators at several levels, suggesting implementation interventions could be targeted towards both the individual-, the social interactions and context-, and also the organisation and available resources level. Assurance of clinicians’ individual competence, peer support, and clinical leadership seem to be important areas to intervene. Stroke thrombolysis rates have expanded over time, and an increase in stroke thrombolysis delivery to patients with mild stroke symptoms has contributed to this increase. However, it seems considerable differences between hospitals inhibit equity of care delivery. Further, socioeconomically disadvantaged groups receive less often stroke thrombolysis. Type of hospital seems to play a role, yet the reasons for this difference are not fully understood. This thesis also display that stroke thrombolysis-treated women that survive 1 year after stroke, appears to face higher risk for dependency in ADL, compared to men.
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| 8. |
- Wåhlin, Nils, 1955-
(författare)
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Näringslivsledares arbete i nätverk : identitetsskapandets dynamik
- 1994
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is concerned with the work of business leaders. The interest lies in the holders of positions as Chairpersons, Boardmembers and Managing Directors. This study, however, goes beyond the position holder to consider the actions of actors, as they operate within networks with concurrent multiple business activities. The purpose is to generate knowledge and understanding of the activities and relations of multibusiness leaders involved in managing small and medium-sized companies.Major schools of thought on the manager's job are described. The review relates the scientific debate about different schools and emphasises the need for more inductive research. The call for processual and contextual analysis leads to an epistemological position grounded in understanding through interpretation. The method used in this study adopts such an approach, and thus aims to discover qualities of the studied phenomenon based on social constructivism. Empirical reality is approached by means of intensive studies of a few cases.Case descriptions of the work of multibusiness leaders in the National, Regional, Intermediary, Independent, and Developing Networks are undertaken, where the interaction processes of the different actors are described according to the working life history of the actor, and to the networking and work activities carried out.The analysis is based upon four themes (the actor's 'task legitimacy', 'economic legitimacy', 'idea development' and 'network'). The first two themes have been given the generic term 'legitimacy concept', not only to reflect the interactive and changeable aspects of work, but also to illustrate how work in itself is intimately interwoven in an institutional context. The creation of 'task legitimacy' and 'economic legitimacy' of the leaders is analysed. The analysis of the actors' idea development results in a description of differing visions in the individual networks. This description takes up visions covering long-term industrial leadership, regional co-operative leadership, restructuring leadership, flexible market-adaptive leadership and network-based leadership.In a survey of the existing literature, the role of a leader is seen as one of many managerial roles, a view that is based upon the work of Mintzberg (1973). This study contrasts with the above picture, by discussing a reciprocal dependency between the leader's leadership role and his/her other roles. This reciprocity and concurrency is dealt with by introducing the concept of identity as a theoretical aid, thus reflecting in a more appropriate way the complex and interactive actor.The social identity concept (Tajfel, 1982) is used, in order to answer more profoundly the research questions. As leaders are reciprocally dependent on a network for their own existence, we must both look inward in order to be able to understand at a deeper level the actors' motives, and look outward to be able to look at identity creation in a wider industry context. What I have termed näringslivsledaridentitet (the Identity of Multibusiness Leaders), is a substantial part of this study's findings. The concept is used in order to be able to describe how the actors' inner and outer motives merge in identity creating processes. The actors' different patterns of interaction are absorbed into a composite whole.
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