Uptake and fecal excretion of Coxiella burnetii by Ixodes ricinus and Dermacentor marginatus ticks

Background: The bacterium Coxiella burnetii is the etiological agent of Q fever and is mainly transmitted via inhalation of infectious aerosols. DNA of C. burnetii is frequently detected in ticks, but the role of ticks as vectors in the epidemiology of this agent is still controversial. In this study, Ixodes ricinus and Dermacentor marginatus adults as well as I. ricinus nymphs were fed on blood spiked with C. burnetii in order to study the fate of the bacterium within putative tick vectors. Methods: Blood-feeding experiments were performed in vitro in silicone-membrane based feeding units. The uptake, fecal excretion and transstadial transmission of C. burnetii was examined by quantitative real-time PCR as well as cultivation of feces and crushed tick filtrates in L-929 mouse fibroblast cells and cell-free culture medium. Results: Ticks successfully fed in the feeding system with engorgement rates ranging from 29% (D. marginatus) to 64% (I. ricinus adults). Coxiella burnetii DNA was detected in the feces of both tick species during and after feeding on blood containing 105 or 106 genomic equivalents per ml blood (GE/ml), but not when fed on blood containing only 104 GE/ml. Isolation and cultivation demonstrated the infectivity of C. burnetii in shed feces. In 25% of the I. ricinus nymphs feeding on inoculated blood, a transstadial transmission to the adult stage was detected. Females that molted from nymphs fed on inoculated blood excreted C. burnetii of up to 106 genomic equivalents per mg of feces. Conclusions: These findings show that transstadial transmission of C. burnetii occurs in I. ricinus and confirm that I. ricinus is a potential vector for Q fever. Transmission from both tick species might occur by inhalation of feces containing high amounts of viable C. burnetii rather than via tick bites

Untersuchung der in vivo Kinetik von ApoB3543 (ApoB-Marburg) mittels stabiler Isotopentechnik

Hypercholesterinämien, insbesondere Erhöhungen des LDL-Cholesterin sind ein Hauptrisikofaktor für die koronare Herzkrankheit (KHK). Die Lipoproteine geringer Dichte (LDL) spielen eine zentrale Rolle im Prozess der Atherogenese. Das Hauptstrukturprotein der LDL ist Apolipoprotein B 100. Apo B 100 ist essentiell für die Bindung der LDL an den LDL-Rezeptor und deren Aufnahme in die Zelle. Bindungsdefekte des Apo B an den LDL-Rezeptor (familiär defektes Apo B; FDB) und LDL-Rezeptordefekte (Familiäre Hypercholesterinämie) sind die häufigste Ursache monogenetischer Hypercholesterinämien. Mittlerweile sind 4 Mutationen im ApoB-Gen bekannt, die durch eine Änderung der Bindungsstelle zum LDL-Rezeptor bedingen (Arg3500Gln; Arg3531Cys; Arg3500Trp; R3480W). Ziel der Arbeit war es ein Kollektiv von 853 koronarangiographierten Patienten mittels DGGE (denaturierender Gradienten Gelelektrophorese) auf Mutationen in der Codon 3456-3553 Region zu untersuchen. In dieser Region liegen alle bis dato beschriebenen, mit einer Hypercholesterinämie einhergehenden ApoB-Defekte. Der Lipoproteinstoffwechsel der Mutationsträger wurde mittels stabiler Isotopentechnik untersucht. Wir fanden fünf Patienten mit einer Mutation in der Codon 3456-3553 Region des Apo B-100 Gens. Wir können noch keine Aussagen zur Häufigkeit dieser Mutation in der Allgemeinpopulation machen, aber in unserem KHK- Kollektiv war sie die häufigste Mutation, vergleichbar der Häufigkeit der R3500Q- Mutation in anderen KHK- Kollektiven. Eine Patientin der fünf gefundenen Mutationsträger war die Trägerin der bekannten FDBR3500Q- Mutation. Die R3500Q- Mutation ist die am besten beschriebene FDB- Mutation und bedingt einen Austausch der basischen Aminosäure Arginin gegen das neutrale Glutamin. Die Patientin zeigte in bezug auf Klinik und Lipoproteinp arametern ein vergleichbares Verhalten, wie die, in anderen Untersuchungen, beschriebenen R3500Q- Mutationsträger. Wir konnten bei vier der fünf Patienten eine noch nicht beschriebene His3543Tyr- Mutation im Exon 26 des Apo B-100 Gens darstellen Die Mutation bedingt einen Austausch der basischen Aminosäure Histidin gegen die neutrale Aminosäure Tyrosin. Es kommt zu einem Verlust einer positiven Ladung in einem, für die ApoB-100- Konformation und die Bindung an den LDL- Rezeptor, elementaren Bereich des Apo B-100. Eine Beeinflussung des Lipoproteinhaushaltes durch zusätzliche Mutationen im LDL- Rezeptorgen oder durch den ApoE- Polymorphismus konnten wir ausschließen. Die ApoBMarburg- Mutation zeigt bei moderaterer Ausprägung der Hypercholesterinämie ein ähnliches klinisches Bild, wie die bisher beschriebenen FDB- Mutationen. Wir fanden in der in- vivo- Kinetikuntersuchung des Lipidstoffwechsels dieser Mutationsträger große Veränderungen, verglichen mit dem Lipidmetabolismus normaler Probanden. Die Veränderungen, besonders des ApoB-100- Stoffwechsels, stimmen mit den bisher beschriebenen Turnoveruntersuchungen der FDB- Mutationen R3500Q und R3500W überein. Auch bei unserer Mutation sehen wir die mehrfach vorbeschriebene Variationsbreite in der klinischen und metabolischen Ausprägung der FDB- Mutationen. Wir folgern aus diesen Gründen, dass es sich bei der His3543Tyr- Mutation um eine klinisch relevante Mutation handelt, die ähnliche klinische und metabolische Auswirkungen auf den Lipidstoffwechsel hat wie die bisher beschriebenen FDB- Mutationen. Weiterhin muss diese neue Mutation als häufige, angeborene Ursache der Hyperlipidämie gewertet werden

QuestEnvSim: Environment-Aware Simulated Motion Tracking from Sparse Sensors

Replicating a user's pose from only wearable sensors is important for many AR/VR applications. Most existing methods for motion tracking avoid environment interaction apart from foot-floor contact due to their complex dynamics and hard constraints. However, in daily life people regularly interact with their environment, e.g. by sitting on a couch or leaning on a desk. Using Reinforcement Learning, we show that headset and controller pose, if combined with physics simulation and environment observations can generate realistic full-body poses even in highly constrained environments. The physics simulation automatically enforces the various constraints necessary for realistic poses, instead of manually specifying them as in many kinematic approaches. These hard constraints allow us to achieve high-quality interaction motions without typical artifacts such as penetration or contact sliding. We discuss three features, the environment representation, the contact reward and scene randomization, crucial to the performance of the method. We demonstrate the generality of the approach through various examples, such as sitting on chairs, a couch and boxes, stepping over boxes, rocking a chair and turning an office chair. We believe these are some of the highest-quality results achieved for motion tracking from sparse sensor with scene interaction

Ballistic bipolar junctions in chemically gated graphene ribbons

The realization of ballistic graphene pn-junctions is an essential task in order to study Klein tunneling phenomena. Here we show that intercalation of Ge under the buffer layer of pre-structured SiC-samples succeeds to make truly nano-scaled pn-junctions. By means of local tunneling spectroscopy the junction width is found to be as narrow as 5 nm which is a hundred times smaller compared to electrically gated structures. The ballistic transmission across the junction is directly proven by systematic transport measurements with a 4-tip STM. Various npn- and pnp-junctions are studied with respect to the barrier length. The pn-junctions are shown to act as polarizer and analyzer with the second junction becoming transparent in case of a fully ballistic barrier. This can be attributed to the almost full suppression of electron transmission through the junction away from normal incidence.DFG/SPP/145

Population Inversion in Monolayer and Bilayer Graphene

The recent demonstration of saturable absorption and negative optical conductivity in the Terahertz range in graphene has opened up new opportunities for optoelectronic applications based on this and other low dimensional materials. Recently, population inversion across the Dirac point has been observed directly by time- and angle-resolved photoemission spectroscopy (tr-ARPES), revealing a relaxation time of only ~ 130 femtoseconds. This severely limits the applicability of single layer graphene to, for example, Terahertz light amplification. Here we use tr-ARPES to demonstrate long-lived population inversion in bilayer graphene. The effect is attributed to the small band gap found in this compound. We propose a microscopic model for these observations and speculate that an enhancement of both the pump photon energy and the pump fluence may further increase this lifetime.Comment: 18 pages, 6 figure

Effects of dietary menthol-rich bioactive lipid compounds on zootechnical traits, blood variables and gastrointestinal function in growing sheep

Background The present study aimed at investigating the influence of 90% menthol-containing plant bioactive lipid compounds (PBLC, essential oils) on growth performance, blood haematological and biochemical profile, and nutrient absorption in sheep. Twenty-four growing Suffolk sheep were allotted into three dietary treatments: Control (without PBLC), lower dose of PBLC (PBLC-L; 80 mg/d) and higher dose of PBLC (PBLC-H; 160 mg/d). Sheep in all groups were fed meadow hay ad libitum plus 600 g/d of concentrate pellets for 28 d. Results Average daily gain was not affected by treatment. Feeding of PBLC increased hay and total feed intake per kg body weight (P < 0.05). Counts of total leucocytes, lymphocytes and monocytes were not different among treatments. However, neutrophil count decreased (P < 0.05) in PBLC-H with a similar trend in PBLC-L (P < 0.10). Concentrations of glucose, bilirubin, triglycerides, cholesterol, urea and magnesium in serum were not different among sheep fed different doses of PBLC. However, serum calcium concentration tended to increase in PBLC-H (P < 0.10) and serum concentrations of aspartate & asparagine (P < 0.01) and glutamate & glutamine (P < 0.05) increased linearly with increasing PBLC dose. In ruminal epithelia isolated from the rumen after killing, baseline conductance (Gt; P < 0.05) and short-circuit current (Isc; P < 0.01) increased in both PBLC groups. Ruminal uptakes of glucose and methionine in the presence of Na+ were not affected by the dietary PBLC supplementation. In the absence of Na+, however, glucose and methionine uptakes increased (P < 0.05) in PBLC-H. In the jejunum, Isc tended to increase in PBLC-H (P < 0.10), but baseline Gt was not affected. Intestinal uptakes of glucose and methionine were not influenced by PBLC in the presence or absence of Na+. Conclusion The results suggest that menthol-rich PBLC increase feed intake, and passive ion and nutrient transport, the latter specifically in the rumen. They also increased serum concentrations of urea precursor amino acids and tended to increase serum calcium concentrations. Future studies will have to show whether some of these findings might be commonly linked to a stimulation of transient receptor potential (TRP) channels in the gastrointestinal tract

Developing and Evaluating a University Recommender System

A challenge for many young adults is to find the right institution to follow higher education. Global university rankings are a commonly used, but inefficient tool, for they do not consider a person's preferences and needs. For example, some persons pursue prestige in their higher education, while others prefer proximity. This paper develops and evaluates a university recommender system, eliciting user preferences as ratings to build predictive models and to generate personalized university ranking lists. In Study 1, we performed offline evaluation on a rating dataset to determine which recommender approaches had the highest predictive value. In Study 2, we selected three algorithms to produce different university recommendation lists in our online tool, asking our users to compare and evaluate them in terms of different metrics (Accuracy, Diversity, Perceived Personalization, Satisfaction, and Novelty). We show that a SVD algorithm scores high on accuracy and perceived personalization, while a KNN algorithm scores better on novelty. We also report findings on preferred university features.publishedVersio

Phonon-pump XUV-photoemission-probe in graphene: evidence for non-adiabatic heating of Dirac carriers by lattice deformation

We modulate the atomic structure of bilayer graphene by driving its lattice at resonance with the in-plane E1u lattice vibration at 6.3um. Using time- and angle-resolved photoemission spectroscopy (tr-ARPES) with extreme ultra-violet (XUV) pulses, we measure the response of the Dirac electrons near the K-point. We observe that lattice modulation causes anomalous carrier dynamics, with the Dirac electrons reaching lower peak temperatures and relaxing at faster rate compared to when the excitation is applied away from the phonon resonance or in monolayer samples. Frozen phonon calculations predict dramatic band structure changes when the E1u vibration is driven, which we use to explain the anomalous dynamics observed in the experiment.Comment: 16 pages, 8 figure

Ultrasonographic Evaluation of Teat Structure and Detection of Prominent Annular Folds in Brazilian Dairy Buffaloes

Udder and teat characteristics differ between buffaloes (Bubalus bubalis) and cattle (Bos taurus) and the differences are important in relation machine milk ability. Dairy buffalo milk out more slowly and are more difficult to milk than dairy cows, especially when milking machines are used. The goal of this study was to determine the ultrasonographic characteristics of udder and teat morphology in dairy buffaloes in Brazil, a country with a relatively recent history of buffalo farming. External assessment of the udder type and ultrasonography of the teat were done in 63 purebred Murrah and Mediterranian x Murrah dairy buffalo cows on three farms with different management systems. Udder types differed among farms; the rear-heavy udder type was most prevalent on two farms and the ball-shaped type occurred frequently on the third farm. Ultrasonographic measurements of the teat were made on one farm and showed correlations between the width of the teat tip and teat canal length, between the width of the teat tip and teat wall thickness and between the width of the teat tip and teat length. During the ultrasonographic examination of the teat, hyperechogenic membrane-like structures in the region of the annular folds, referred to as prominent annular folds (pAFs), were detected in at least one teat in 98 % of all buffaloes. These folds caused narrowing of the lumen between the teat cistern and gland cistern, but their physiological function and relevance concerning machine milk ability remain unclear. Further studies are needed to evaluate the effect of prominent annular folds on milk flow characteristics during mechanical milking in dairy buffaloes