High data rate wireless packet data networks have made real-time IP based services available through mobile devices. At the same time, differences in the characteristics of radio technologies (802.11/WiFi and 3G networks) make seamless handoff across heterogeneous wireless networks difficult. Despite this, many believe that the ultimate goal of next generation networks (often referred to as the fourth generation) is to allow convergence of such dissimilar heterogeneous networks. Supporting voice over Internet Protocol in next-generation wireless systems is thought by some to require support for mobility and quality of service features. Currently a mobile node can experience interruptions or even sporadic disconnections of an on going real-time session due to handovers between both networks of different types and networks of the same type. Many tests have already been done in this area and one may wonder why it is worth spending even more time investigating it? This thesis focuses on the important problem of providing session security despite handovers between networks (be they operated by the same operator or different operators and be they the same link technologies or different). One of the goals in this thesis is to investigate how an ongoing speech session can continue despite a change in transmission media1. Additionally, a number of security threats that could occur due to the handover will be identified and presented. Finally, the most suitable solution to address these threats will be tested in a real environment. Eventual shortcomings and weaknesses will be identified and presented; along with suggestions for future work.  1 When utilizing IP over carriers such as wired Ethernet, WLAN, and 3G. / Trådlösa hög-hastighets datanät har möjliggjort appliceringen av realtids tjänster på mobil utrustning över IP. Samtidigt har skillnaderna i de olika radioteknologierna (802.11/WiFi och 3G näten) introducerat nya problem med att upprätthålla trådlösa kommunikationen tvärs den heterogena trådlösa accessen. Många tror att slutmålet för nästa generations nätverk (ofta refererade som fjärde generationens nätverk) är att tillåta konvergensen av dessa olika heterogena nätverk. Stödet för Voice over Internet Protokollet (VoIP) i nästa generations trådlösa nät tror somliga kräver ett inslag av kombination mellan mobilitet samt upprätthållandet av kvaliteten. För närvarande kan den mobila noden (MN) råka ut för störningar och även sporadiska avbrott av en pågående realtidssessionen på grund av övergångar mellan samma eller olika typer av medier. Många tester har redan gjorts inom det här området och man kan fråga sig varför det är värt att lägga ner ännu mer tid på att undersöka det här? Det här examensarbetet fokuserar på det viktiga problemet som handlar om att kunna erbjuda sessions säkerhet trots övergångar mellan näten (oavsett om dessa drivs av samma eller olika operatörer samt oavsett om de är av samma eller olika nätverks typ). Ett av målen för det här examensarbetet är att undersöka hur en pågående talsession behålls vid byte av transmissionsmedia2. Vidare kommer olika säkerhetsaspekter och hot som kan tänkas uppstå vid bytet att identifieras och presenteras. Slutligen kommer den mest lämpade lösningen till problemet att testas i verklig miljö. Eventuella brister och svagheter kommer att identifieras och redovisas i slutet av rapporten tillsammans med förslag på framtida arbete. 2 Då man nyttjar IP bärare som trådbundet Ethernet, WLAN och 3G.

This study aims to generate increased understanding for, and to portray, the mobile lifestyle vanlife by examining motives, obstacles and potential consequences of this particular lifestyle.  The study was conducted using qualitative method. The selection of study participants was aimed towards people who own or have owned a mobile home and lives or have lived in it periodically at the least. The selection was interviewed through semi structured interviews, and the empiric material was analyzed using thematic analysis.  The results show that vanlife can be seen as a form of voluntary simplicity because it’s a minimalistic lifestyle both in terms of resource- and energy consumption and because of the simpler dwelling. Vanlife can also be seen as a form of lifestyle migration because of the great importance of the destination to people within vanlife, but also because they can move to these places whenever they feel due to the flexible mobility of their homes.  The strongest motive is freedom in various aspects – such as freedom to travel but also financial freedom. Another strong motive is the feeling of belonging to a community. The opinions about the environmental impact of the lifestyle are divided among the participants, but some testify of negative impacts on local environments. Cold weather and safety concerns are some of the obstacles to vanlife, and a feeling of not belonging anywhere are one of the consequences. Additionally, vanlifers don’t want to be confused with people living at traditional camping grounds.

The non-homogenous demographic distribution in the northern parts of Sweden complicates the conditions to operate well-functioning public transport. The accessibility varies between bigger cities and smaller towns. Because of the covid-19 outbreak, one may see how the changed travel patterns vary geographically. This thesishas examined how the daily travel with bus in the region of Västerbotten have changed because of the covid-19 pandemic. Six bus lines in the region are examined based on the categories: short-, mid-range- and long travel distances. A comparison in travel volume between these lines are done, one week before the pandemic compared with the same week one year after. The comparison is based on ticket type and travel distance. The study shows that the decrease of travels with bus in the region of Västerbotten is more noticeable on shorter travel distances, where the regular travel volume also is higher. A decrease is in that way clearer in areas with higher population density. At mid-range distances, there is a less prominent decrease in travel volume compared to short and long travel distances. Meanwhile, the change in travels depending on ticket type shows that season tickets have decreased the most. The variation between agesshows that limited travel patterns affect older generations more. The spatial variation of travels in the region highlights eventual future problems with the provision of public transport. Areas where the travel volume were low before the pandemic, now has even lower volumes. This complicates the main role of public transport, to maintain aregional cohesion and provide well-functioning transport service to all citizens.

The Mammoth Site in Hot Springs, South Dakota preserves a unique death assemblage of sub-adult and adult male Columbian mammoths (Mammuthus columbi). Extensive work on the site has led to a detailed understanding of the taphonomy of the assemblage; yet the life histories and ecology of these mammoths remain relatively unknown. Tooth enamel from four Mammoth Site mammoth individuals were bulk sampled with one of the individuals (MSL 742) also serially micro-sampled for 𝛿13C, 𝛿18O, and 87Sr/86Sr. Isotopic results indicate that MSL 742 remained within the southern and western Black Hills year-round with no consistent migration patterns. 𝛿13C and 𝛿18O values contain minimal fluctuations, suggesting drinking water and forage was sourced from the local hot springs and surrounding landscape. This study suggests the high level of sloped landscapes in the region may have resulted in a “bull”-only region, explaining the absence of females and juvenile mammoths at the site.

The flexibility of future mobile networks exploiting modern technologies such as cloud-optimized radio access and software-defined networks opens a gateway to deploying dynamic strategies for live and on-demand content delivery. Traditional live broadcasting systems are spectral inefficient. It takes up a lot more radio spectrum than that of mobile networks, to cover the same size of an area. Furthermore, content caching at base stations reduces network traffic in core networks. However, numerous duplicated copies of contents are still transmitted in the unicast fashion in radio access networks. It consumes valuable radio spectrum and unnecessary energy. Finally, due to the present of numerous mobile receivers with a wide diversity of wireless channels in a base station coverage area, it is a challenge to select a proper modulation scheme for video broadcasting to optimize the quality of services for users. In this thesis, the challenges and the problems in the current strategies for content delivery are addressed. A holistic novel solution is proposed that considers user preferences, user mobility, device-to-device communication, physical-layer resource allocation, and video quality prediction. First, a system-level scheduling framework is introduced to increase the spectral efficiency on broadcasting live contents onto mobile networks. It considers the audience preferences for allocating radio resources spatially and temporally. Second, to reduce the redundant transmissions in radio access networks, a content distribution system that exploits user mobility is proposed that utilizes the urban-scale user mobility and broadcasting nature of wireless communication for delay-tolerant large size content. Third, to further reduce the energy consumption in network infrastructure, a content distribution system that relies on both user mobility, and device-to-device communication is proposed. It leverages the mobile users as content carriers to offload the heavy mobile traffic from network-level onto device-level. Fourth, to mitigate the multi-user channel diversity problem, a cross-layer approach is deployed to increase the video quality for users especially for those who have a low signal-to-noise ratio signal. Finally, data mining techniques are employed to predict video qualities of wireless transmissions over mobile networks. The holistic solution has been empirically developed and evaluated. It achieves high spectral and energy efficiency and mitigates the video quality degradation in mobile networks.

Background As digitalization and the Internet of Things (IoT) evolves in a rapid pace, the need for engineers, IT specialists and software developers introduce an increasing shortage of skilled workers. Managing the existing workforce is a challenge, increasing the interest in the antecedents and implications of their mobility activities. Employee turnover has been broadly viewed as a disadvantage for firms losing valuable human capital, increasing the implementation of retention strategies. On the other hand, an increasing amount of studies argue that mobility within a region is a source of knowledge spillovers and can enhance innovation and productivity, as well as regional economic growth by facilitating access to new external ideas and capabilities. There is a gap in the research on employees’ perception of opportunities and preferences that leads them to engage in mobility within the regional high-tech sector instead of other types of mobility. Objectives The purpose of this thesis is to increase the understanding of what factors influence the mobility of employees within the regional high-tech industry. Therefore, the perceived opportunities and preferences for different types of mobility are investigated. The aim is that the findings will facilitate the management of employee mobility and maximize the local organizations’ joint human capital. Method A quantitative survey study is conducted, collecting data from two high-tech organizations operating within the same geographical region. The collected data includes individual, organizational and external factors, as well as the intentions for turnover and considerations for different types of mobility. SPSS is used to statistically test what factors are associated with high-tech employees’ opportunities and preferences for mobility within the regional industry. Results High-tech personnel perceive most opportunities for alternative employment within the high-tech industry in another region, while finding another job within the region is perceived more difficult. If employees considered leaving their current organization, most would prefer to take a job within the regional high-tech industry. Satisfaction with pay, training opportunities and supervisors in the current job have a reducing effect on the intention to leave the organization, while perception of having alternative employment opportunities have an increasing effect on both turnover intention and for considering mobility within the same industry. No significant model for predicting the preference for mobility within the same region was found in this study. Conclusions The majority of high-tech personnel already prefer mobility within the regional industry if they were leaving their current job, but there is a mismatch with the perceived opportunities for this type of mobility. Actions towards matching the opportunities with the preferences are expected to result in benefits for the region by increasing the local overall knowledge base, provide the organizations with more opportunities to attract highly skilled workers locally, and increase employees’ job satisfaction and performance through better job-matches.

Vehicle to Vehicle (V2V) communication provides a flexible and real-time information dissemination mechanism through various applications of Intelligent Transportation Systems (ITS). Achieving seamless connectivity through multi-hop vehicular communication with sparse network is a challenging issue. In this paper, we have studied this multi-hop vehicular connectivity in an urban scenario using GPS traces obtained from San Francisco Yellow cabs. Our current work describes a new algorithm for the analysis of topological properties like connectivity and partitions for any kind of vehicular or mobile computing environment. The novel approach uses bitwise manipulation of sparse matrix with an efficient storage technique for determining multi-hop connectivity. The computation mechanism can be further scaled to parallel processing environment. The main contribution of this research is threefold. First, developing an efficient algorithm to quantify multi-hop connectivity with the aid of bitwise manipulation of sparse matrix. Second, investigating the time varying nature of multi-hop vehicular connectivity and dynamic network partitioning of the topology. Third, deriving a mathematical model for calculating message propagation rate in an urban environment.

Myocardial dysfunction is a major consequence of septic shock and contributes to the high mortality of sepsis. High-mobility group box 1 (HMGB1) serves as a late mediator of lethality in sepsis. We have reported that glucan phosphate (GP) attenuates cardiac dysfunction and increases survival in cecal ligation and puncture (CLP)-induced septic mice. In the present study, we examined the effect of GP on HMGB1 translocation from the nucleus to the cytoplasm in the myocardium of septic mice. GP was administered to mice 1 h before induction of CLP. Sham-operated mice served as control. The levels of HMGB1, Toll-like receptor 4 (TLR4), and NF-κB binding activity were examined. In an in vitro study, H9C2 cardiomyoblasts were treated with lipopolysaccharide (LPS) in the presence or absence of GP. H9C2 cells were also transfected with Ad5-IκBα mutant, a super repressor of NF-κB activity, before LPS stimulation. CLP significantly increased the levels of HMGB1, TLR4, and NF-κB binding activity in the myocardium. In contrast, GP administration attenuated CLP-induced HMGB1 translocation from the nucleus to the cytoplasm and reduced CLP-induced increases in TLR4 and NF-κB activity in the myocardium. In vitro studies showed that GP prevented LPS-induced HMGB1 translocation and NF-κB binding activity. Blocking NF-κB binding activity by Ad5-IκBα attenuated LPSinduced HMGB1 translocation. GP administration also reduced the LPS-stimulated interaction of HMGB1 with TLR4. These data suggest that attenuation of HMGB1 translocation by GP is mediated through inhibition of NF-κB activation in CLP-induced sepsis and that activation of NF-κB is required for HMGB1 translocation.

No description available.

Stable isotopes of mammoths and mastodons have the potential to illuminate ecological changes in late Pleistocene landscapes and megafaunal populations as these species approached extinction. The ecological factors at play in this extinction remain unresolved, but isotopes of bone collagen (δ13C, δ15N) and tooth enamel (δ13C, δ18O, 87Sr/86Sr) from midwestern North America are leveraged to examine ecological and behavioral changes that occurred during the last interglacial-glacial cycle. Both species had significant C3 contributions to their diets and experienced increasing levels of niche overlap as they approached extinction. A subset of mastodons after the last glacial maximum exhibit low δ15N values that may represent expansion into a novel ecological niche, perhaps densely occupied by other herbivores. Stable isotopes from serial and microsampled enamel show increasing seasonality and decreasing temperatures as mammoths transitioned from Marine Isotope Stage (MIS) 5e to glacial conditions (MIS 4, MIS 3, MIS 2). Isotopic variability in enamel suggests mobility patterns and life histories have potentially large impacts on the interpretation of their stable isotope ecology. This study further refines the ecology of midwestern mammoths and mastodons demonstrating increasing seasonality and niche overlap as they responded to landscape changes in the final millennia before extinction.