324 research outputs found
Information Aggregation with Costly Information and Random Ordering: Experimental Evidence
The cost of information is an often ignored factor in economic situations although the information acquisition behavior of the decision makers has a crucial influence on the outcome. In this experiment, we study an information aggregation process in which participants decide in a random sequence. Participants observe predecessors decisions and can acquire additional private information at a fixed price. We analyze participants information acquisition behavior and updating procedures. About one half of the individuals act rationally, whereas the other participants systematically overestimate the private signal value. This leads to excessive signal acquisitions and reduced conformity.
Information aggregation with costly information and random ordering : experimental evidence
The cost of information is an often ignored factor in economic situations although the information acquisition behavior of the decision makers has a crucial influence on the outcome. In this experiment, we study an information aggregation process in which participants decide in a random sequence. Participants observe predecessors decisions and can acquire additional private information at a fixed price. We analyze participants information acquisition behavior and updating procedures. About one half of the individuals act rationally, whereas the other participants systematically overestimate the private signal value. This leads to excessive signal acquisitions and reduced conformity
The angiographic presentation of European Moyamoya angiopathy.
BACKGROUND AND PURPOSE
Little is known about the angiographic presentation of Moyamoya angiopathy (MMA) in non-Asian patients.
METHODS
Conventional cerebral angiograms from 155 Caucasian patients diagnosed as MMA were analyzed with respect to extracranial champagne bottle neck sign, Suzuki stages, collateral status, as well as presence of aneurysms and posterior cerebral artery stenosis.
RESULTS
In 84 of 155 angiograms, the extracranial carotid artery was visualized, in 65 of them (77.4%), a champagne bottle neck sign was noted. Of the 278 analyzable hemispheres, 13.7%,11.2%, 37.8%, 27.3%, 8.6%, and 1.4% were classified as Suzuki stage I, stage II, stage III, stage IV, stage V, and stage VI, respectively. Among 280 hemispheres, in 53 hemispheres (18.9%) isolated basal collaterals (pathway I) and in 104 hemispheres (37.1%) choroidal and pericallosal collaterals (including basal collaterals, pathway II) were found. In 74 hemispheres (26.4%) ethmoidal collaterals (pathways III), and in 17 hemispheres (6.1%) vault collaterals were visualized. Patients with higher Suzuki stages IV-VI (pâ=â0.008) and ethmoidal collaterals (pâ<â0.001) suffered more often from cerebral hemorrhage. Transient ischemic attacks occurred more frequently in patients with Suzuki stage I to III (pâ<â0.001). In 10 of 155 patients (6.5%), the angiogram revealed a cerebral aneurysm. In 13 patients (8.4%), a stenotic P1 segment of the posterior cerebral artery was found.
CONCLUSIONS
This is so far the largest observational study about angiography in Caucasian European MMA patients. A comparison with Asian data indicates similarity of disease in Caucasian and Asian patients
Insights into the decontamination of cocaine-positive hair samples
A highly discussed step in hair sample preparation for forensic analytics is the applied decontamination. The here presented investigations aim to gain insight and give recommendations on how to conduct this decontamination for the analysis of cocaine consumption in hair. Key insights were gained from the investigation of cocaine consumer hair, which was artificially contaminated in a humid atmosphere with 13C6 labelled cocaine and from cocaine powder contaminated hair. Several decontamination protocols were investigated, whereby the usage of a decontamination protocol consisting of multiple short repetitive washes allowed to visualize the wash-out of (13C6-) cocaine. Multiple methanol washes proved to be an efficient and simple decontamination approach. Our findings showed that decontamination protocols can successfully wash-out recent cocaine contaminations. They were observed to be rather quickly washed-out, whereas cocaine from consumption or âolderâ cocaine contaminations were shown to eliminate both at a constant rate (from inner hair compartments). Thus, the usage of decontamination protocols to differentiate between consumption and contamination was shown to be limited. As contamination can happen any time at any level, only the application of elaborated decision trees, based on cocaine metabolite ratios and thresholds, can provide the distinction between consumption and contamination. Thus, the authors highly recommend the usage of such tools on all hair samples analyzed for cocaine consumption
Cutaneous manifestations in Moyamoya angiopathy: A review.
AbstractBackground and purpose: Moyamoya angiopathy (MA) is a progressive cerebrovascular disease with a poorly understood pathophysiology. It is mainly characterized by progressive bilateral stenosis of the terminal intracranial part of the supraclinoid internal carotid arteries and the proximal parts of the middle and anterior cerebral arteries. This results in earlyâonset ischemic or hemorrhagic strokes. The disease may be idiopathic (known as Moyamoya disease) or associated with other heritable or acquired conditions, including type 1 neurofibromatosis or other RASopathies, sickle cell disease, Down syndrome, or autoimmune disorders (known as Moyamoya syndrome). Apart from the brain, other organ manifestations including cutaneous ones have also been described in MA patients.Materials and methods: A literature research on PubMed was performed for articles mentioning the cutaneous association in MA and published between 1994 and October 2020.Conclusion: The present review summarizes the cutaneous associations as well as the coincidental dermatological findings seen in MA patients. Those include changes in the epidermis, dermis, or skin appendages for example cafĂ©âauâlait spots, hypomelanosis of Ito, livedo racemosa, hemangiomas, premature graying of hair, chilblains etc
Livedo racemosa in neurological diseases: an update on the differential diagnoses
Livedo is a netâlike violaceous skin pattern. It can be classified as physiological or pathological. The physiological livedo reticularis usually appears in cold conditions, whereas the pathological and irregular livedo, which persists in warm temperatures, is often labeled as 'livedo racemosa'. Some neurological pathologies are associated with livedo, most commonly those with an inflammatory component or those derived from systemic disorders. The present review summarizes the most important central and peripheral neurological diseases in pediatric and adult age groups associated with livedo, providing physicians with an overview of the clinical presentation, etiology, diagnosis and management of these conditions
Die Wahrnehmung von UmweltgefĂ€hrdungen: Ăsterreich im internationalen Vergleich
"Dieser Beitrag untersucht die Wahrnehmung verschiedener UmweltgefĂ€hrdungen in Ăsterreich und im internationalen Vergleich. Die zentrale Fragestellung ist, wie sich die Risikowahrnehmung ĂŒber die LĂ€nder hinweg und innerhalb der LĂ€nder unterscheidet. Die Analyse basiert auf reprĂ€sentativen Bevölkerungsumfragen, die im Rahmen des International Social Survey Programme ISSP zwischen 2010 und 2013 in 34 LĂ€ndern erhoben wurden. Die empirische Analyse zeigt eine Differenzierung entlang Problemen, die mit naturrĂ€umlichen Gegebenheiten wie Wasserknappheit in Zusammenhang stehen, sowie sozial induzierten Alltagsproblemen wie MĂŒllentsorgung und sozial bedingten weitreichenden Problemen wie Klimawandel und AtommĂŒll. NaturrĂ€umliche Probleme werden vor allem in LĂ€ndern wie Mexiko und SĂŒdafrika genannt und können daher mit klimatischen Bedingungen erklĂ€rt werden, wĂ€hrend die beiden sozial induzierten Problemfelder keinen spezifischen LĂ€ndergruppen zugeordnet werden können. Ăsterreich selbst liegt im Mittelfeld, weder naturrĂ€umliche noch sozial induzierte Probleme werden hier ĂŒberproportional hĂ€ufig wahrgenommen." (Autorenreferat)"This article explores the perception of environmental problems in Austria within the context of a comparative international approach. The analysis centers on the question of differences in risk perception across countries and within countries. It utilizes representative national public opinion data, which were collected by the International Social Survey Programme ISSP in 34 countries between 2010 and 2013. The results indicate a differentiation along nature and climate oriented problems such as water shortage, socially induced everyday issues (for example waste disposal), and socially induced severe problems, i.e. climate change and nuclear waste. Whereas the first set of problems can be found in countries such as Mexico and South Africa and thus be explained by climate conditions, socially induced problems are not linked to specific sets of countries or regions. Finally, the Austrian perception of the different risks is moderate, thus neither natural problems nor socially induced problems are named disproportionately often when compared with other countries." (author's abstract
LC-MS/MS analysis of Î9-THC, CBN and CBD in hair: investigation of artefacts
In forensic toxicology, high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) is increasingly used for the fast and sensitive measurement of a wide range of drugs. For our routine casework, a liquid chromatography atmospheric pressure chemical ionization-tandem mass spectrometry (LC-APCI-MS/MS) method for the quantification of Î9-tetrahydrocannabinol (Î9-THC), cannabinol (CBN) and cannabidiol (CBD) in hair was established and fully validated. Separation was achieved using a KinetexÂź C18 column (100âmm Ă 2.1âmm, 100âĂ
, 1.7âÎŒm, Phenomenex) at a flow rate of 0.5âmL/min. Measurements were performed on a QTrap 5,500 mass spectrometer (Sciex, Darmstadt, Germany). Unexpected signals were observed in authentic THC-positive hair samples. First, a signal with a slightly shifted retention time of THC whose origin could be assigned to the isomer Î8-THC. Second, additional peaks exhibiting the same fragments as CBN and Î9-THC but eluting at different retention times were detected. Spiking experiments and enhanced product ion scans (EPI) pointed to the origin of these additional signals as result of in-source decarboxylation of Î9-tetrahydrocannabinolic acid A (Î9-THCA-A) into Î9-THC and further partial oxidation of Î9-THC into CBN, respectively. Positive findings of Î9-THCA-A in hair have been shown to derive from external contamination, therefore, the herein described artefacts may be used as indirect markers for external contamination
Single sample preparation for the simultaneous extraction of drugs, pharmaceuticals, cannabinoids and endogenous steroids in hair
A combined sample preparation for the simultaneous extraction of drugs, pharmaceuticals, cannabinoids and endogenous steroids was developed based on three independent fully validated analytical methods.
Recently, we published a multi-analyte method for the simultaneous analysis of 116 drugs and pharmaceuticals including different substance groups like opioids, stimulants, benzodiazepines, z-drugs, antidepressants and neuroleptics based on a single sample workup followed by a single analytical measurement with LC-MS/MS. However, in some cases, additional analysis of further substance groups, such as cannabinoids and endogenous steroids, is required, which are analyzed in our laboratory using separate sample preparation and separate analytical methods. The goal of this study was to use the knowledge from the different sample preparations and combine them into a single sample preparation and extraction workflow for the simultaneous extraction of drugs, pharmaceuticals, cannabinoids, and endogenous steroids to be analyzed with the appropriate analytical methods. A partial validation of selected parameters such as selectivity, linearity, limit of quantification (LOQ), accuracy, precision and robustness for the different analytical methods was carried out and revalidated. In addition, comparative measurements of quality controls and authentic pools were performed and statistically evaluated using the unpaired t-test or the non-parametric Mann-Whitney test. The results using the newly established sample preparation and extraction were in good agreement with the original data. In conclusion, the newly established sample preparation is suitable for the combined extraction of drugs, pharmaceuticals, cannabinoids and endogenous steroids, and gives reliable results for quantification of various substances
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Standardised Models for Inducing Experimental Peritoneal Adhesions in Female Rats
Animal models for adhesion induction are heterogeneous and often poorly described. We compare and discuss different models to induce peritoneal adhesions in a randomized, experimental in vivo animal study with 72 female Wistar rats. Six different standardized techniques for peritoneal trauma were used: brushing of peritoneal sidewall and uterine horns (group 1), brushing of parietal peritoneum only (group 2), sharp excision of parietal peritoneum closed with interrupted sutures (group 3), ischemic buttons by grasping the parietal peritoneum and ligating the base with Vicryl suture (group 4), bipolar electrocoagulation of the peritoneum (group 5), and traumatisation by electrocoagulation followed by closure of the resulting peritoneal defect using Vicryl sutures (group 6). Upon second look, there were significant differences in the adhesion incidence between the groups (P < 0.01). Analysis of the fraction of adhesions showed that groups 2 (0%) and 5 (4%) were significantly less than the other groups (P < 0.01). Furthermore, group 6 (69%) was significantly higher than group 1 (48%) (P < 0.05) and group 4 (47%) (P < 0.05). There was no difference between group 3 (60%) and group 6 (P = 0.2). From a clinical viewpoint, comparison of different electrocoagulation modes and pharmaceutical adhesion barriers is possible with standardised models
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