1,873 research outputs found
Toll-like receptor (TLR) 2 and TLR4 gene expression in canine heart
Toll-like receptors (TLRs) are archetypal pattern recognition receptors of immediate importance for an efficacious innate immune response. TLRs exhibit marked differential tissue activity and their levels within a discrete cell type can be highly dynamic. Of 13 known mammalian paralogues, three TLRs have been identified in the dog. Although cardiac TLR expression has been reported in other species, this study is the first to present evidence that these innate immune receptors are expressed in the canine heart. Heart tissue samples from all four chambers were collected from healthy dogs immediately after euthanasia and stored at -80°C until analysis. Total RNA was extracted with TRI Regent. Specific primers were designed for amplification of canine TLR2 and TLR4 based on previously reported sequences for these genes. Reverse transcription was performed with M-MLV reverse transcriptase. PCR amplification was performed and PCR products analyzed by agarose gel electrophoresis. Bands were excised from the gel and the DNA isolated and cloned using the TA CloningŸ Kit. The correct sequence for each product was verified by nucleotide sequencing. TLR4 expression was detected in the left ventricle and right atrium; TLR2 was detectable at low levels in the right atrium only. Identity of the RT-PCR products was confirmed by sequencing. Our findings show that at least two TLR paralogues- namely TLR2 and TLR4 - are expressed in the canine heart. Additional studies are warranted to determine these immune receptors' potential implication in the development of naturally occurring heart disease in the dog
In vino veritas: Theory and evidence on social drinking
It is a persistent phenomenon in many societies that a large proportion of alcohol consumption takes place in company of other people. While the phenomenon of social or public drinking is well discussed in disciplines as social psychology and anthropology, economists have paid little attention to the social environment of alcohol consumption. This paper tries to close this gap and explains social drinking as a trust facilitating device. Since alcohol consumption tends to make some people (unwillingly) tell the truth, social drinking can eventually serve as a signaling device in social contact games. Empirical support is obtained from a cross-country analysis of trust and a newly developed index of moderate alcohol consumption. --social and public drinking,alcohol consumption,social contact games,trust,signaling
Vetoing and inaugurating policy like others do : evidence on spatial interactions in voter initiatives
A sizeable literature studies whether governments strategically interact with each other
through policy-diffusion, learning, fiscal and yardstick competition. This paper asks
whether, in the presence of direct democratic institutions, spatial interactions additionally
result from votersâ direct actions. The proposed mechanism is that the votersâ
actions in vetoing a decision or inaugurating a preferred policy by a binding initiative
in their jurisdiction can potentially have spillover effects on the actions of voters and
special interest groups of neighboring jurisdictions. Utilizing data on around 1,800
voter-petitions across over 12,000 German municipalities in 2002-09, we find that a
jurisdictionâs probability of hosting a petition is positively driven by the neighborsâ direct
democratic activity. These effects are persistent, and are stronger for more visible
instruments of direct democracy. The interactions are also mostly driven by petitions
in same or similiar policy areas, and are stronger in towns with relatively more per
capita newspapers
Design of a parallel robot with additively manufactured flexure hinges for a cryogenic work environment
Automation is ubiquitous in today's industrial landscape and is finding its way into more and more highly specialised applications - also in the field of cryopreservation. The extreme work conditions in cryobanks place exceptionally high demands on the mechanical and electronic components used. The preservation and storage of biological samples take place at temperatures between -130 °C and -196 °C using liquid nitrogen as a cooling medium. The bearings and joints used in industrial parallel kinematic robots (for example, ball bearings or Cardan joints) jam at these ambient parameters and are unsuitable for an application within a cryobank. We, therefore, develop methods and technologies to enable fully automated handling of biological samples under cryogenic working conditions. The basis for this is a parallel kinematic robot structure that allows the drives to be placed outside the cold environment. In contrast, the rest of the robot structure can be actuated in a cryogenic container. In this context, the passive joints for this parallel robot are designed as additively manufactured monolithic flexure hinges. This paper presents the design, simulation, and construction of the parallel robot and focuses on the flexure hinges fabricated using the selective laser melting process (SLM). We describe the design of the flexure hinges, their intended use in the robot, and the experimental setup used for their validation. We also compare the operating parameters recorded in experiments (such as bending angle, bending moment) with the data obtained in finite element method simulations (FEM). In addition, we describe the geometric constraints and deviations of the manufactured joints due to the manufacturing process
Enterprise Liability, Public and Private
In Sweden, where forests cover more than 60% of the land area, silviculture and the use of forest products by industry and society play crucial roles in the national carbon balance. A scientific challenge is to understand how different forest management and wood use strategies can best contribute to climate change mitigation benefits. This study uses a set of models to analyze the effects of different forest management and wood use strategies in Sweden on carbon dioxide emissions and removals through 2105. If the present Swedish forest use strategy is continued, the long-term climate change mitigation benefit will correspond to more than 60 million tons of avoided or reduced emissions of carbon dioxide annually, compared to a scenario with similar consumption patterns in society but where non-renewable products are used instead of forest-based products. On average about 470 kg of carbon dioxide emissions are avoided for each cubic meter of biomass harvested, after accounting for carbon stock changes, substitution effects and all emissions related to forest management and industrial processes. Due to Swedenâs large export share of forest-based products, the climate change mitigation effect of Swedish forestry is larger abroad than within the country. The study also shows that silvicultural methods to increase forest biomass production can further reduce net carbon dioxide emissions by an additional 40 million tons of per year. Forestryâs contribution to climate change mitigation could be significantly increased if management of the boreal forest were oriented towards increased biomass production and if more wood were used to substitute fossil fuels and energy-intensive materials
Comparative study of probabilistic modeling approaches for chloride ingress in concrete structures with macroâcracks
Probabilistic service life analyses for assessing the risk of chloride-induced corrosion in uncracked concrete are often realized using the well-known chloride ingress model of the fib Model Code for Service Life Design. In practice, however, concrete includes cracks, which alter the resistance of the concrete against the chloride ingress. In the past, different approaches to account for preexisting cracks, were developed. In this study, these modeling approaches are summarized and compared in context of the probabilistic service life prognosis. Furthermore, a new approach to account for cracks by theoretically adapting the convection zone is presented. This study demonstrates that the choice of model extension to account for cracks vastly influences the prediction results and shows the limits of application of the current extensions
Auswirkungen des Klimas auf das Bauen mit Beton
Durch den Klimawandel werden sich auch die Einwirkungen auf das Bauen im Allgemeinen, vor allem aber auf den
Baustoff Beton im Speziellen verĂ€ndern. In diesem Zusammenhang sind die zukĂŒnftig höchstwahrscheinlich hĂ€ufiger
auftretenden Maximaltemperaturen ĂŒber 30 °C zu nennen. Um die Auswirkungen des Klimawandels auf den
Frisch- und Festbeton abschÀtzen zu können, wurden im Rahmen dieses Beitrags unterschiedliche Regelwerke auf
deren GĂŒltigkeit ĂŒberprĂŒft, fĂŒr den Fall, dass perspektivisch mit höheren Lufttemperaturen zu rechnen ist. Die
Bemessungsmodelle der Regelwerke wurden mit Hilfe von aktuellen Klimadaten exemplarisch fĂŒr Rheinstetten bei
Karlsruhe bewertet. Aufgrund der Bewertung lÀsst sich Folgendes ableiten: der Einfluss steigender Lufttemperaturen
wird sich auf die Frischbetoneigenschaften in der Zukunft kritischer auswirken. Sowohl die HydratationswÀrmeentwicklung
des Zements als auch die OberflĂ€chenverdunstung des Frischbetons rĂŒcken stĂ€rker in den Fokus.
Sie mĂŒssen durch praxistaugliche technologische MaĂnahmen auf ein sinnvolles MaĂ reduziert werden. Die Eigenschaften
des Festbetons sind von der Betontemperatur und dessen relativem Feuchtegehalt abhĂ€ngig. HierfĂŒr
liegen jedoch noch keine normierten Materialmodelle vor. Jedoch fĂŒhren nur wesentlich erhöhte Temperaturen in
Kombination mit einem hohen Feuchtegehalt des Betons zu kritischen Festigkeitsverlusten. Derzeit wird nicht davon
ausgegangen, dass die vom Klimawandel verursachten erhöhten Temperaturen solche kritischen Umgebungsrandbedingungen
erzeugen werden, dass diese zu einer BeeintrĂ€chtigung der Festbetoneigenschaften fĂŒhren
werden. Jedoch berĂŒcksichtigen die gegenwĂ€rtig verfĂŒgbaren Regelwerke weder fĂŒr die Frischbeton- noch fĂŒr die
Festbetoneigenschaften, die sich offensichtlich verÀndernden Klimarandbedingungen
Insights in the thermal volume transition of poly(2-oxazoline) hydrogels
Polymers with a lower or an upper critical solution temperature (LCST or UCST) can precipitate in a very narrow temperature range. Cross-linking of such polymers and adding them to suited solvent results in smart gels that are capable of greatly changing their dimensions with changing temperature. This transition occurs very often in a broad temperature range, which limits the applicability of smart materials. To shed some light into the design of thermo-responsive hydrogels with a narrow phase transition, poly(2-ethyl-2-oxazoline) (PEtOx), poly(2-isopropyl-2-oxazoline), and statistical copolymers of 2-butyl-2-oxazoline and 2-ethyl-2-oxazoline, respectively, are synthesized and the concentration-dependent cloud point temperatures (Tcp) of the free polymers in aqueous media are determined in relation to the thermo-responsive swelling behavior of the respective hydrogels. A narrow thermal transition of the hydrogels can only be achieved when the Tcp of the free polymers in water is independent on the concentration. Aqueous salt solutions can render even PEtOx into a concentration independent LCST polymer. However, this salt effect does not work for hydrogels
Daring to process the trauma: using a web-based training to reduce psychotherapistsâ fears and reservations around implementing trauma-focused therapy
Sansen L, Saupe L, Steidl A, Fegert JM, Hoffmann U, Neuner F. Daring to process the trauma: using a web-based training to reduce psychotherapistsâ fears and reservations around implementing trauma-focused therapy. European Journal of Psychotraumatology. 2019;10(1): 1696590.Although trauma-focused interventions are the first-line therapies for patients with posttraumatic stress disorder (PTSD), they are not frequently used in clinical practice. Factors preventing therapists from applying trauma-focused methods include a lack of training and negative attitudes towards trauma-focused therapy. The aim of the present study was to investigate which factors predict willingness to carry out trauma-focused therapy and to examine whether a web-based training is able to reduce negative attitudes and reservations about these interventions. In a wait-list controlled evaluation study, therapists (N = 499) were randomized into an intervention or a wait-list control group. Results show that trauma-treatment specific competencies and overcoming pre-existing concerns towards trauma-focused therapy significantly predict therapistsâ willingness to utilize trauma-focused interventions. Thus, the content alignment of the web-based course is appropriate for improving therapistsâ willingness to conduct trauma-focused therapy. A retrospective examination of therapists after the training and a comparison of fears and reservations before and after the training demonstrate a significant reduction of fears and reservations. In terms of perceived contraindications, no effects of the web-based training were found. The present study provides compelling evidence that web-based training in evidence-based PTSD therapy is able to reduce reservations that may prevent therapists from applying evidence-based trauma-focused interventions
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TLR4 Deficiency Protects against Hepatic Fibrosis and Diethylnitrosamine-Induced Pre-Carcinogenic Liver Injury in Fibrotic Liver
Background
The development of hepatocellular carcinoma (HCC) is a common consequence of advanced liver fibrosis but the interactions between fibrogenesis and carcinogenesis are still poorly understood. Recently it has been shown that HCC promotion depends on Toll-like receptor (TLR) 4. Pre-cancerogenous events can be modelled in mice by the administration of a single dose of diethylnitrosamine (DEN), with HCC formation depending amongst others on interleukin (IL) 6 production. Mice lacking the hepatocanalicular phosphatidylcholine transporter ABCB4 develop liver fibrosis spontaneously, resemble patients with sclerosing cholangitis due to mutations of the orthologous human gene, and represent a valid model to study tumour formation in pre-injured cholestatic liver. The aim of this study was to investigate DEN-induced liver injury in TLR4-deficient mice with biliary fibrosis.
Methods
ABCB4-deficient mice on the FVB/NJ genetic background were crossed to two distinct genetic backgrounds (TLR4-sufficient C3H/HeN and TLR4-deficient C3H/HeJ) for more than 10 generations. The two congenic knockout and the two corresponding wild-type mouse lines were treated with a single dose of DEN for 48 hours. Phenotypic differences were assessed by measuring hepatic collagen contents, inflammatory markers (ALT, CRP, IL6) as well as hepatic apoptosis (TUNEL) and proliferation (Ki67) rates.
Results
Hepatic collagen accumulation is significantly reduced in ABCB4-/-:TLR4-/-double-deficient mice. After DEN challenge, apoptosis, proliferation and inflammatory markers are decreased in TLR4-deficient in comparison to TLR4-sufficient mice. When combining ABCB4 and TLR4 deficiency with DEN treatment, hepatic IL6 expression and proliferation rates are lowest in fibrotic livers from the double-deficient line. Consistent with these effects, selective digestive tract decontamination in ABCB4-/- mice also led to reduced tumor size and number after DEN.
Conclusion
This study demonstrates that liver injury upon DEN challenge depends on pre-existing fibrosis and genetic background. The generation of ABCB4-/: TLR4-/- double-deficient mice illustrates that TLR4-deficiency protects against hepatic injury in a preclinical mouse model of chronic liver disease
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