Förekomst av klinisk fotröta och Dichelobacter nodosus hos svenska slaktlamm

Fotröta är en smittsam klövsjukdom hos får som har stor påverkan på djurhälsa och produktion. Sjukdomen ger en nekrotiserande inflammation i klövspaltshuden, som senare ger en underminering av klövens sulhorn. I de allvarligaste fallen kan sjukdomen leda till att klövkapseln lossnar. Kliniskt bedöms fotröta enligt en femgradig skala (0-5), där grad 0 representerar en frisk klöv och grad 5 en allvarligt infekterad klöv. I Sverige krävs minst en klöv med fotröta > grad 2 för att man ska klassa ett får som drabbat av klinisk fotröta. Fotröta orsakas av Dichelobacter nodosus, en anaerob och gramnegativ bakterie. D. nodosus har både virulenta och benigna stammar, vilka har olika möjlighet att orsaka sjukdom hos får. Bakterien bedöms ha begränsad förmåga att överleva i miljön, och sprids framförallt via direkt och indirekt kontakt mellan får. Det första fallet av fotröta i Sverige rapporterades 2004. År 2009 genomfördes en prevalensstudie på svenska slaktlamm och prevalensen var då 5,8 %. Syftet med den här studien var att göra en uppdaterad prevalensstudie hos svenska slaktlamm för den kliniska förekomsten av fotröta och jämföra dessa resultat med den tidigare utförda prevalensstudien från 2009. I studien skedde också provtagning för att undersöka förekomsten av D. nodosus hos slaktlamm med hjälp av PCR. De D. nodosus som upptäcktes i studien virulensbestämdes för att ge en bild över distributionen av virulenta och benigna stammar som förekommer i landet. Under hösten 2020 samlades 2048 klövar in från 512 slaktlamm in från 8 olika slakterier runtom i landet. Klövarna bedömdes kliniskt och graderades enligt den femgradiga skalan. Samtliga klövar provtogs med svabb för att undersöka förekomsten av D. nodosus genom att köra svabbproverna i en detektions-PCR. De prover som var positiva för D. nodosus analyserades i ytterligare en PCR för att virulensbestämmas. Prevalensen undersöktes både på nationell nivå och på regional nivå, där landet delades in i tre olika regioner baserat på slakteriernas geografiska placering: södra Sverige, norra Sverige och Gotland. Resultatet från studien visade att prevalensen av fotröta grad 2 var 1,8 %, av fotröta grad 1 14,9 % och att 83,6 % av klövarna var friska (fotröta grad 0). Inga klövar med fotröta > grad 3 hittades i studien. Inga regionala skillnader i prevalens kunde ses gällande klinisk fotröta (grad 2). Förekomsten av D. nodosus var 6,1 % och förekomsten var signifikant större i södra Sverige jämfört med Gotland. D. nodosus var vanligast på klövar med fotröta grad 2, men förekom även hos klövar med fotröta grad 1 och 0. Samtliga D. nodosus som hittades i studien var benigna. Prevalensen i den här studien var signifikant lägre än i studien som utfördes 2009. Förekomsten av fotröta har alltså minskat hos svenska slaktlamm, vilket är positivt för både djurvälfärd och produktion. D. nodosus är inte vitt spridd hos slaktlammen och förekom endast hos 6,1 % av provtagna djur i den här studien. Alla D. nodosus som upptäcktes i den här studien var benigna, vilket gör att förekomsten av virulent D. nodosus kan anses vara låg inom landet.Footrot is an infectious claw disease in sheep that has an impact on both animal welfare and production. The clinical signs of the disease is a necrotising inflammation in the interdigital skin that later evolves to underrunning of the sole horn and, in the most severe cases, causes a complete separation of the hoof capsule from underlying tissues. Clinically, a scoring system is used to determine the severity of the disease. The scoring system has different scores (0-5), where score 0 indicates a completely healthy hoof and score 5 a severely affected hoof. In Sweden, clinical footrot is defined as the presence of a lesion scored > 2 in at least one hoof of the animal. Footrot is caused by Dichelobacter nodosus, an anaerobic and Gram-negative bacterium. D. nodosus has both benign and virulent strains, with different capability to cause disease in sheep. The bacterium’s ability to survive in the environment is limited, and the main transmission of the disease occurs directly and indirectly between sheep. The first case of footrot in Sweden was reported in 2004. In 2009, a study was conducted on the prevalence of footrot in Swedish slaughter lambs and a prevalence of 5.8% were reported. The aim of this study was to perform an updated prevalence study on footrot in Swedish slaughter lambs and compare this with the previous results from the prevalence study in 2009. All of the lambs were also sampled to determine the prevalence of D. nodosus via a PCR assay. The samples where D. nodosus could be found were analysed in another PCR-assay to determine their virulence, and to provide information regarding the distribution of benign and virulent strains in Sweden. Feet from 512 slaughter lambs (in total 2048 feet) were collected from 8 different slaughter houses located in different areas of the country during autumn 2020. All feet were clinically examined and scored according to the previously described scoring system. Swab samples were taken from all feet to detect the presence of D. nodosus. Samples where D. nodosus was detected were also analysed to determine the virulence of the found bacteria. The prevalence was evaluated both nationally and regionally, where the country was devided in to three different regions: south of Sweden, north of Sweden and Gotland. The prevalence of footrot score 2 in this study was 1.8%, of footrot score 1 14.9% and of footrot score 0 83.6%. No lambs with a score > 3 were found in this study. No regional differences in prevalence of footrot score > 2 were significant. The prevalence of D. nodosus was 6.1%, and the prevalance was significantly higher in south of Sweden when compared to the prevalence on Gotland. D. nodosus was most common on hooves with score 2, but was also detected on hooves with score 1 and 0. All D. nodosus detected in this study were benign. The prevalence in this study was significantly lower than the previously reported prevalence in 2009. This shows that footrot has decreased in Swedish slaughter lambs, which is positive with regard to both animal welfare and production. D. nodosus is not widely spread among the slaughter lambs, with a prevalence of 6.1 % in this study. All the D. nodosus found in this study were benign, which shows that the prevalence of virulent D. nodosus in Sweden is probably low

Operando Single Particle Catalysis - Combining a Nanoreactor and Plasmonic Nanospectroscopy

Heterogeneous catalysis is an important cornerstone of modern society with strong ties to the development of sustainable sources of energy and products. Catalysts are typically realized as supported metal nanoparticles that offer active sites that can accelerate chemical reactions by providing energetically more favorable reaction paths. Despite their broad use, the scrutiny of catalysts under realistic application conditions, such as high pressure and temperature, is a major experimental challenge. This difficulty is further amplified by the complexity present in real catalysts, often consisting of large ensembles of nanoparticles that all are unique. Furthermore, reactors used in catalysis studies often give rise to ill-defined reaction conditions in terms of catalyst distribution, reactant concentration and temperature. To mitigate these challenges, techniques are being developed to enable studies of catalytic nanoparticles under relevant operation conditions, so-called operando techniques. In this context, down-sized chemical reactors can be utilized to achieve precise control of both the catalyst, and the operating conditions. In this thesis, I have performed in situ studies of chemical reactions in/on nanoparticles by utilizing plasmonic nanospectroscopy based on the localized surface plasmon resonance (LSPR) phenomenon. The resonance condition for LSPR depends on both nanoparticle properties (size, shape, material) and the surrounding medium, which makes it possible to determine the physical and chemical state of individual nanoparticles optically. The LSPR response was used to study the oxidation of Cu nanoparticles, revealing the complex nature of nanoparticle oxidation kinetics, as well as particle specific oxidation mechanisms. Furthermore, a nanoreactor platform was developed and used in combination with plasmonic nanospectroscopy to perform operando characterization of individual Cu and Pt catalyst nanoparticles during CO oxidation. The obtained results illustrate how the oxidation of Cu results in catalyst deactivation and how reactant gradients formed inside the catalyst bed strongly affects the state of the catalyst, and thus its activity. Moreover, the nanoreactor enabled operando characterization of catalyst beds comprising 1000 well defined nanoparticles that could be individually addressed

Targeting smooth muscle microRNAs for therapeutic benefit in vascular disease.

In view of the bioinformatic projection that a third of all protein coding genes and essentially all biological pathways are under control of microRNAs (miRNAs), it is not surprising that this class of small RNAs plays roles in vascular disease progression. MiRNAs have been shown to be involved in cholesterol turnover, thrombosis, glucose homeostasis and vascular function. Some miRNAs appear to be specific for certain cells, and the role that such cell-specific miRNAs play in vascular disease is only beginning to be appreciated. A notable example is the miR-143/145 cluster which is enriched in mature and highly differentiated smooth muscle cells (SMCs). Here we outline and discuss the recent literature on SMC-expressed miRNAs in major vascular diseases, including atherosclerosis, neointima formation, aortic aneurysm formation, and pulmonary arterial hypertension. Forced expression of miR-145 emerges as a promising strategy for reduction and stabilization of atherosclerotic plaques as well as for reducing neointimal hyperplasia. It is concluded that if obstacles in the form of delivery and untoward effects of antimirs and mimics can be overcome, the outlook for targeting of SMC-specific miRNAs for therapeutic benefit in vascular disease is bright

Democracy or Dictatorship: An American Reaction to the Developments in The Netherlands Between 1935 and 1945

From Suffering and Survival: The Netherlands, 1940-1945, a four-day conference held at Dordt College in the fall of 1990 to commemorate the 50th anniversary of the Nazi occupation of The Netherlands and the 45th anniversary of The Netherlands\u27 liberation

The damper levels influence on vehicle roll, pitch, bounce and cornering behaviour of passenger vehicles - A study in cooperation with Volvo Car Corporation

The competition within the automotive industry is increasing. It is therefore important to reduce the resources and time spent on developing new vehicles. A significant part of the development is the chassis tuning which consumes a lot of time and resources. Dampers have a key role in chassis tuning and a better understanding of how the level of damping affects the vehicle behaviour could reduce both the number of prototypes built and the time spent on chassis tuning. This thesis investigates the possibility to develop a tool which captures the vehicle behaviour accurately enough to be used for choosing damper levels in the concept phase and as an aid in the tuning of dampers. A Simulink model was developed together with a graphical user interface allowing the user to easily change the level of damping and run simulations. In order to validate the model and see how changes to the level of damping affect the vehicle behaviour, both subjective and objective tests were performed for different damper configurations. It was found that the changes in vehicle behaviour for the various damper levels had a good correlation between the simulation model and the results from the physical tests. However in absolute numbers differences were found between simulations and objective tests. In order to verify the simulation model a limited number of objective tests are required. The tested vehicle should also be measured properly in order to receive better input data to the simulation model.The study found that the pitch balance in the vehicle is mostly affected by the difference in compression and rebound damping between the front and rear dampers. Lower damping at low vertical wheel velocities has a negative impact on roll control. This can to a limited extent be compensated with higher roll stiffness. A good balance between the front and rear damping is also required in order to have good connection to the road and make the vehicle feel more comfortable. The subjective and objective evaluation showed that it might be the time lag between lateral acceleration and steering wheel angle is a good indication of the vehicles turn-in capabilities and that the roll angle time lag determines the response. However more objective and subjective tests are required in order to confirm this connection. A better understanding of how to define good vehicle behaviour objectively is also required if the tool should be used in the concept phase

What effect does the relationship between the encoding-retrieval match and cue overload have on memory performance? Is confidence-accuracy correlation affected by the diagnostic value of a cue? An assessment of memory functions.

The encoding-retrieval match has been established as a means to improve memory performance. It has recently been proposed that memory performance is not only explained by the encoding-retrieval match and that the cue overload effect needs to be taken into account when predicting memory performance. In the present study, participants were tested using a cued recall methodology. During a study phase, participants viewed word-pairs with pictures in the background. During the test phase the participants identified whether intact or recombined word-pairs were presented while again having pictures in the background. The pictures contributed as retrieval cues during the test phase. The participants also rated their confidence about their decision on a 1-5 scale. By using the pictures in the background as the manipulation, memory performance in a Baseline condition, a Diagnostic Cue condition (with a unique picture) and a Non-Diagnostic Cue condition (with a re-used picture) was statistically analyzed to explore the relationship between the encoding-retrieval match and the cue overload effect. The analysis showed that during the Diagnostic Cue condition, participants’ performance was enhanced relative to the Baseline condition. The cue overload effect undermined the positive effect that the encoding-retrieval match had on memory performance during the Non-Diagnostic Cue condition. Confidence ratings significantly and positively correlated with accuracy. No significant difference between the CA-correlations of the different conditions was discovered. This study's results suggests that a cues diagnostic value has great importance for whether a person may benefit or not from the encoding-retrieval match during cued recall

REFERENCE LETTERS AND THE UNINFORMED BUSINESS EDUCATOR: A U.S. LEGAL PERSPECTIVE

While providing references to students, business professors have to meet dual demands of giving sincere references to prospective employers while avoiding any potential litigation claims of “defamation” and “violation of privacy” from the students. While the approach of providing bare minimum information may seem to mitigate the risk of litigation claims of defamation from former students, it might serve as a potential pitfall for facing “intentional misrepresentation” liability from the prospective employer. This paper addresses these concerns, together with other legal issues U.S. business educators face in this area of potential liability. Suggestions are offered to those who provide references for the purpose of minimizing the possibility of litigation exposure, either from the student or from his future employer

Best practice in determining key photophysical parameters in triplet–triplet annihilation photon upconversion

Triplet–triplet annihilation photon upconversion (TTA-UC) is a process in which low-energy light is transformed into light of higher energy. During the last two decades, it has gained increasing attention due to its potential in, e.g., biological applications and solar energy conversion. The highest efficiencies for TTA-UC systems have been achieved in liquid solution, owing to that several of the intermediate steps require close contact between the interacting species, something that is more easily achieved in diffusion-controlled environments. There is a good understanding of the kinetics dictating the performance in liquid TTA-UC systems, but so far, the community lacks cohesiveness in terms of how several important parameters are best determined experimentally. In this perspective, we discuss and present a “best practice” for the determination of several critical parameters in TTA-UC, namely triplet excited state energies, rate constants for triplet–triplet annihilation (kTTA), triplet excited-state lifetimes (τT), and excitation threshold intensity (Ith). Finally, we introduce a newly developed method by which kTTA, τT, and Ith may be determined simultaneously using the same set of time-resolved emission measurements. The experiment can be performed with a simple experimental setup, be ran under mild excitation conditions, and entirely circumvents the need for more challenging nanosecond transient absorption measurements, a technique that previously has been required to extract kTTA. Our hope is that the discussions and methodologies presented herein will aid the photon upconversion community in performing more efficient and manageable experiments while maintaining—and sometimes increasing—the accuracy and validity of the extracted parameters