Valence band study of thermoelectric Zintl-phase SrZn_2Sb_2 and YbZn_2Sb_2: X-ray photoelectron spectroscopy and density functional theory

The electronic structure of SrZn_2Sb_2 and YbZn_2Sb_2 is investigated using density functional theory and high-resolution x-ray photoemission spectroscopy. Both traditional Perdew-Burke-Ernzerhof and state-of-the-art hybrid Heyd-Scuseria-Ernzerhof functionals have been employed to highlight the importance of proper treatment of exchange-dependent Zn  3d states, Yb 4f states, and band gaps. The role of spin-orbit corrections in light of first-principles transport calculations are discussed and previous claims of Yb^(3+) valence are investigated with the assistance of photoelectron as well as scanning and transmission electron microscopy

Security aspects of OSPF as a MANET routing protocol

OSPF, Open Shortest Path First, is an Intra-gateway routing protocol first developed as an IETF effort. It is widely adopted in large enterprise-scale networks, being well regarded for its fast convergence and loop-free routing. It is versatile in terms of which interface types it supports, such as point-to-point links or broadcast networks. It also offers scalability through hierarchical routing and by using centralization to reduce the amount of overhead on networks which have broadcast or broadcast-similar properties. An interface type missing from the standard so far is that of a wireless network, characterized by non-guaranteed bidirectional links combined with unreliable broadcasting, and existing interface types generally perform poorly under these networks. The IETF has therefore instituted a Working Group to standardize such an interface type extension to the latest version, OSPF version 3. This interface type will permit mobility and multi-hop characteristics in addition to those of wireless links in general. Such networks are usually referred to as Mobile Ad-hoc Networks (MANET). MANET routing protocols are subject to more severe security issues than ordinary, wireline-oriented protocols are. This thesis aims to indentify key security aspects of OSPF as a MANET routing protocol

Endringsledelse ved implementering av digitale systemer

Masteroppgaven har fokus på følgende problemstilling: Hvilke grep kan ledelsen i E-verket ta for å forbygge og handtere endringsmotstand i organisasjonen knyttet til implementering av digitale verktøy og systemer? For å belyse problemstillingen nærmere, har jeg lagt til grunn følgende forskningsspørsmål: a) Hvorfor oppstår endringsmotstand blant ansatte i E-verket ved gjennomføring av digitale endringsprosesser? b) Hvilke tiltak kan ledelsen i E-verket gjennomføre for å øke måloppnåelsen i digitaliseringsprosesser? For å besvare forskningsspørsmålene har jeg benyttet en casestudie. Datagrunnlaget er innhentet gjennom intervju med 5 ansatte i E-verket. I det teoretiske underlaget har jeg i første delen av oppgaven hatt fokus på teori og forskning som kan forklare hvorfor endingsmotstand oppstår. I den andre delen har jeg vektlagt å få fram relevant forskning som kan underbygge ledelsestiltak for å forebygge endingsmotstand samt tiltak for å handtere endingsmotstand. I denne delen har endringsledelse stått sentralt. Den overordnede målsettingen i studien har vært å få fram kunnskap om hvordan E-verket i større grad kan lykkes med implementering av digitale systemer med utgangspunkt i et endringsperspektiv. Studien gir i liten grad grunnlag for å trekke slutninger mht. spesifikke årsaksfaktorer som hver for seg er avgjørende for å forklare endingsmotstand i digitale prosesser. Empirien kan imidlertid gi visse indikasjoner på at det muligens kan foreligge en form for akkumulativ effekt der flere årsaksfaktorer kan inngå og samlet utgjøre et mulig sett av forklaringer på endringsmotstand. I denne forbindelse gir studien visse holdepunkter for at tiltak både enkeltvis og samlet kan være relevant både for å forebygge og handtere endringsmotstand i endringsprosesser. Eksempelvis vil elementer som; vektlegging av bedre kommunikasjon fra ledelsen ved introduksjon av endringsprosesser, større grad av ledelsesinvolvering, bedre opplæring, vektlegging av tiltak for å lette ekstraarbeid som en følge av endringstiltak samt tiltak for i større grad å fremme en kultur for ending i organisasjonen, enkeltvis og/eller samlet, trolig kunne være bidrag til at ledelsen i E-verket i større grad vil kunne lykkes med gjennomføring av framtidige digitaliseringsprosjekter i selskapet

Investigation of the human nasal microbiome in persons with long- And short-term exposure to methicillin-resistant <i>Staphylococcus aureus</i> and other bacteria from the pig farm environment

Since its emergence in the early 2000s, livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398) has led to an increasing number of human infections in Denmark and other European countries with industrial pig production. LA-MRSA CC398 is primarily associated with skin infections among pig farm workers but is also increasingly recognized as a cause of life-threatening disease among elderly and immunocompromised people. Pig farm workers may serve as vehicles for the spread of LA-MRSA CC398 and other farm-origin bacteria between farms and into the general population. Yet, little is known about the bacterial community dynamics in pig farm workers and other persons with long- and short-term exposure to the pig farm environment. To gain insight into this, we investigated the nasal microbiomes in pig farm workers during a workweek on four LA-MRSA CC398-positive pig farms, as well as in short-term visitors two hours before, immediately after, and 48 hours after a 1-hour visit to another LA-MRSA CC398-positive pig farm. S. aureus and LA-MRSA CC398 carriage was quantified by means of culture, and the composition of the bacterial communities was investigated through sequencing of the 16S rRNA gene. Pig farm workers often carried LA-MRSA CC398 and other bacteria from the pig farm environment, both at work and at home, although at lower levels at home. In contrast, short-term visitors were subject to a less dramatic and rapidly reversible change in the nasal bacterial community composition. These results suggest that pig farm workers may be an important source of LA-MRSA CC398 and perhaps other pathogens of human and veterinary relevance

Protein kinase A type I activates a CRE-element more efficiently than protein kinase A type II regardless of C subunit isoform

<p>Abstract</p> <p>Background</p> <p>Protein kinase A type I (PKAI) and PKAII are expressed in most of the eukaryotic cells examined. PKA is a major receptor for cAMP and specificity is achieved partly through tissue-dependent expression and subcellular localization of subunits with different biochemical properties. In addition posttranslational modifications help fine tune PKA activity, distribution and interaction in the cell. In spite of this the functional significance of two forms of PKA in one cell has not been fully determined. Here we have tested the ability of PKAI and PKAII formed by expression of the regulatory (R) subunits RIα or RIIα in conjunction with Cα1 or Cβ2 to activate a co-transfected luciferace reporter gene, controlled by the cyclic AMP responsive element-binding protein (CREB) <it>in vivo</it>.</p> <p>Results</p> <p>We show that PKAI when expressed at equal levels as PKAII was significantly (p < 0.01) more efficient in inducing Cre-luciferace activity at saturating concentrations of cAMP. This result was obtained regardless of catalytic subunit identity.</p> <p>Conclusion</p> <p>We suggest that differential effects of PKAI and PKAII in inducing Cre-luciferace activity depend on R and not C subunit identity.</p

To Invest or Not -- Renewal of the Norwegian Bottom Trawler Fleet

In order to survive and prosper fishing companies have to balance the need for continuity and change. Investment strategy is a good indicator on the direction companies are headed in terms of capacity, onboard production, and the financial risks they are willing to take. However, the success of an investment does not only depend on company decision and timing, but also how companies tackle unpredicted changes in the competitive environment. Cash flow rise and fall with the quota. Accordingly, successful investment strategies in such settings are often linked to timing and capacity decisions. In this paper we propose a framework that explains the investment strategy behind fishing vessel renewal. The hypothesis that cash flow and profitability impact the decision on when to replace an old vessel with a new is tested by studying the pattern of renewal of Norwegian bottom trawlers in a closed fishery. Results suggest that the decision of renewal is taken on rising quota, just before it peaks. Due to long planning and construction time new vessels are operational under conditions very different than predicted. Declining quota and revenues provides challenging conditions, especially for companies building new vessels. However, companies building new vessels have better economic performance than companies not renewing. And vessels being renewed have more fishing licenses than other vessels. An important observation is that the ITQ system has prolonged renewal, as companies buy licenses rather than new vessels. On rising quotas, owners of fully licensed vessels renew 25% of the Norwegian fleet in 2012-2014

Analysis of S–N data for new and corroded mooring chains at varying mean load levels using a hierarchical linear model

Results from full scale fatigue tests of offshore mooring chains are analyzed. The data set includes new and used chains, tested at a variety of mean load levels. The used chains have been retrieved after operation offshore and include samples with varying surface conditions, ranging from as-new to heavily corroded. Based on a parameterized S–N curve intercept parameter, the effects of mean load and chain condition are estimated empirically by regression analysis. A hierarchical linear model is used, to account for and quantify correlations within subsets of the data. The choice of grouping criterion for the hierarchical model is discussed, and assessed based on the current data. Results show that the mean load and corrosion effects are both significant. Differences in the fatigue performance of new versus used chains are quantified and discussed.publishedVersio