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Flat panel CT versus multidetector CT in skull base imaging: are there differences in image quality?
No full textPurpose of this study was to compare image quality of the skull base in standard 20s protocol flat panel computed tomography (FPCT) with the new time and dose improved 10s protocol as well as with 128 slice multidetector computed tomography (MDCT).
10 whole skull preparations were scanned with either 128 slice MDCT(SOMATOM Definition AS+, Siemens, Erlangen) or FPCT (AXIOM-Artis, Siemens, Erlangen) using 10s or 20s protocol.
FPCT provides significantly better image quality and improved delimitation of clinically relevant structures in the anterior, temporal and posterior skull base compared to 128 slice MDCT. The 20s FPCT protocol yielded best delimitability of evaluated skull base structures. However, the shorter, dose saving 10s FPCT protocol was still significantly superior to 128 slice MDCT regarding delimitability of skull base structures and additionally showed no significant inferiority compared with the 20s FPCT protocol.
The 10s FPCT protocol yields a significantly better image quality at a comparable radiation dose exposure in imaging skull base structures compared to MDCT.Gefördert durch den Open-Access-Publikationsfonds der UB Marburg
Explaining Gender Differences in Confidence and Overconfidence in Math
No full textThis paper investigates empirically how and why men and women are different in their confidence levels. In the analysis, confidence is disentangled into two dimensions: confidence in correct math knowledge and overconfidence in false knowledge. Using the data of the PISA test in math, the findings highlight that math abilities have different effects on boys and girls. Overall, math abilities increase confidence and decrease overconfidence. However, the positive effect on confidence is smaller for girls, and the negative effect on overconfidence is larger for them. This gender-asymmetric effect implies that well-performing girls are more constrained from gaining confident attitudes through their abilities, compared to well-performing boys. The empirical evidence further indicates that the gender-asymmetric effect of abilities can be explained by gender socialization that undermines women’s achievements and limit their opportunities
Status and Migration Activity of Lead, Cobalt and Nickel in Water and in Bottom Sediments of Lake Markakol, Kazakhstan
No full textLake Markakol is located in a metal-rich mountain area of Kazakhstan. Metal input into the lake water and in the bottom sediments can be expected. Lead, cobalt and nickel monitoring in both near-surface and deep-water layers and in bottom sediments was carried out using flame atomic absorption spectrometric analyses. Lead contamination of surface water ranging from 2.6 to 6.8 µg/L occurs in all water samples with the exception of the surface water layer. In the deep-water section concentrations reach up to 13.0–16.2 µg/L. Cobalt concentrations range from 36.8 to 67.5 µg/L in the surface layer and from 25.5 to 69.2 µg/L in the deep-water layer. High values of nickel were found in the surface and bottom layers of the water, ranging from 13.5 to 49.0 and 17.2 to 49.0 µg/L, respectively. High concentrations of lead, cobalt and nickel were identified in all samples of the bottom sediments. The lead content in bottom sediments reaches 11.3, cobalt reaches 10.3–18.0 and nickel reaches 15.0 mg kg−1. The results and their assessment can serve as a basis for future monitoring and measures to reduce pollution, restore the lake ecosystem and ensure the safety of fishery products for humans.Gefördert durch den Open-Access-Publikationsfonds der UB Marburg
Left ventricular free wall rupture caused by myocardial ischemia without treatable atherosclerotic coronary disease: a case series
No full textBackground The clinical presentation of left ventricular free wall rupture (LVFWR) varies ranging from uneventful
condition to congestive heart failure.
Case summary Here we report two cases of LVFWR with different clinical presentation and notable outcome.
A 53-year-old male presenting emergently with signs of myocardial infarction received immediate coronary
angiography and thoracic CT-scan showing occlusion of the first marginal coronary branch without possibility of
revascularization and minimal pericardial extravasation. Under ICU surveillance, LVFWR occurred 24 h later and was
treated by pericardiocentesis and ECMO support followed by immediate uncomplicated surgical repair. Postoperative
therapy-refractory vasoplegia and electromechanical dissociation caused fulminant deterioration and the early
death of the patient. The second case is a 76-year old male brought to the emergency room after sudden syncope,
clinical sings of pericardial tamponade and suspicion of a type A acute aortic dissection. Immediate CT-angiography
excluded aortic dissection and revealed massive pericardial effusion and a hypoperfused myocardial area on the
territory of the first marginal branch. Immediate sternotomy under mechanical resuscitation enabled removal of the
massive intrapericardial clot and revealed LVFWR. After an uncomplicated surgical repair, an uneventful postoperative
course, the patient was discharged with sinus rhythm and good biventricular function. One year after the operation,
he is living at home, symptom free.
Discussion Whereas the younger patient, who was clinically stable at hospital admission received delayed surgery
and did not survive treatment, the older patient, clinically unstable at presentation, went into immediate surgery and
had a flawless postoperative course. Thus, early surgical repair of LVFWR leads to best outcome and treating LVFWR as
a high emergency regardless of the symptoms improve survival.Gefördert durch den Open-Access-Publikationsfonds der UB Marburg
Patent Settlements in the Pharmaceutical Industry: What Can We Learn From Economic Analysis?
No full textPatent settlements between originator and generic firms in the pharmaceutical industry have been challenged by antitrust and competition authorities in the U.S. and the EU. Particularly settlementswith large "reverse payments" to generic firms raise the concern of collusive behaviour for protecting weak patents and delaying price competition through generic entry and therefore harming consumers. However, it is still heavily disputed under what conditions such patent settlements are anticompetitive and violate antitrust rules. This article scrutinizes critically what economic analysis has so far contributed to our knowledge about the effects of these patent settlements and the possible rules for their antitrust treatment. An important claim of this paper is that the problem of patent settlements can only be understood, if we analyze it not only from a narrow antitrust perspective but also take into account its deep interrelationship with the problems (and the economics) of the patent system. Therefore we identify three different channels of effects, how patent settlements can influence consumer welfare: (1) price effects, (2) innovation incentive effects, and (3) effects via the incentives to challenge weak patents. The paper critically analyzes the existing economic studies and identifies a number of research gaps, especially also in regard to trade offs between different effects. It also suggests that policy solutions for these patent settlements should also be sought in combination with patent law solutions
CD154 als früher Aktivierungsmarker zur Detektion von antigenspezifischen CD4+ T-Zellen in PBMC von Pemphigus vulgaris-Patienten und Birkenpollenallergikern
No full textDie Analyse der Proliferation und Aktivierung von T-Lymphozyten nach antigener oder mitogener Stimulation ist ein wichtiger Parameter bei der Diagnose verschiedener Immundefekte und bei der Überwachung des Therapieerfolgs. In dieser Arbeit wurden neue Einblicke in die Rolle antigenspezifisch aktivierter T-Zellen bei den zellulären und humoralen Mechanismen der adaptiven Autoimmunantwort bei Pemphigus vulgaris (PV) und Birkenpollenallergie (BPA) gewonnen.
Sowohl nach Stimulation mit humanem Desmoglein (Dsg) 3, dem Hauptautoantigen bei PV, und nach Stimulation mit Birkenpollenextrakt (BPE) war die Expression von CD154 bei PV-Patienten und BPA im Vergleich zu gesunden Kontrollen (K) signifikant erhöht. Das Auftreten von reaktiven CD4+CD154+ T-Zellen war dabei nicht auf spezielle TH-Subtypen begrenzt. Darüber hinaus induzierte die Stimulation mit immundominanten Dsg3-Epitopen, insbesondere P2, eine starke CD4+ T-Zell-Reaktion über eine CD40-CD154-Interaktion, die dem menschlichen Dsg3-Protein ähnelt. Patienten mit aktiver Erkrankung (Partieller Remission) wiesen eine höhere Anzahl von Dsg3-und peptidspezifischen reaktiven CD4+ T-Zellen als Patienten in kompletter Remission oder K auf.
Durch die Isolierung dieser Zellen mittels Oberflächen- und Intrazellularfärbung und anschließender Durchflusszytometrie konnte eine schnelle ex-vivo Manipulation und detaillierte Analyse der CD4+ CD154+ T-Zellen durchgeführt werden. Diese Methode ermöglichte die Detektion von CD154+CD4+ T-Zellen unabhängig von ihrer Zytokinproduktion und MHC-Haplotyp. Die Ergebnisse zeigen, dass die CD154-Expression hoch sensitiv und spezifisch für humane antigenspezifisch aktivierte CD4+ T-Zellen bei PV und BPA ist.
Die Arbeit legt nahe, dass antigenspezifisch aktivierte CD154+ CD4+ T-Zellen eine zentrale Rolle in der Pathogenese spielen. Weitere Untersuchungen sind erforderlich, um die verschiedenen Einflussfaktoren auf die CD154-Expression und die langfristigen Auswirkungen besser zu verstehen. Diese Arbeit legt einen Grundstein für zukünftige prädiktive Mittel zur Überwachung der Krankheitsaktivität und zur Überprüfung von ImmuntherapienThe analysis of T lymphocyte proliferation and activation following antigenic or mitogenic stimulation is an important parameter in the diagnosis of various immunodeficiencies and in monitoring the success of therapy. In this study, new insights were gained into the role of antigen-specific activated T cells in the cellular and humoral mechanisms of the adaptive autoimmune response in pemphigus vulgaris (PV) and birch pollen allergy (BPA).
Both after stimulation with human desmoglein (Dsg) 3, the major autoantigen in PV, and after stimulation with birch pollen extract (BPE), the expression of CD154 was significantly increased in PV patients and BPA compared to healthy controls (K). The appearance of reactive CD4+CD154+ T cells was not limited to specific TH subtypes. Furthermore, stimulation with immunodominant Dsg3 epitopes, especially P2, induced a strong CD4+ T cell response via a CD40-CD154 interaction similar to the human Dsg3 protein. Patients with active disease (partial remission) had higher numbers of Dsg3 and peptide-specific reactive CD4+ T cells than patients in complete remission or K. By isolating these cells using surface and intracellular staining and subsequent flow cytometry, rapid ex vivo manipulation and detailed analysis of CD4+ CD154+ T cells could be performed. This method enabled the detection of CD154+CD4+ T cells independent of their cytokine production and MHC haplotype. The results show that CD154 expression is highly sensitive and specific for human antigen-specific activated CD4+ T cells in PV and BPA.
The work suggests that antigen-specifically activated CD154+ CD4+ T cells play a central role in pathogenesis. Further studies are needed to better understand the various factors influencing CD154 expression and the long-term effects. This work lays a foundation for future predictive tools to monitor disease activity and test immunotherapies
Individual Performance after Success and Failure - A Natural Experiment
No full textThe main goal of our study is to analyze how success and failure in crucial situations affect subsequent individual performance. Our study is based on evidence from a natural experiment of NBA (National Basketball Association) players: Based on play-by-play statistics of NBA games in 10 seasons (1818 observations of 345 sportsmen), we identify players who are responsible for the overtime by taking the last shot of the game. Players who miss the shot when the game is tied perform better in overtime than in the last quarter (within-subject comparison) but not significantly different to their game and season averages. Players who score the equalizer in the last shot of the regular game perform substantially worse in overtime compared to their 4th quarter performance as well as compared to their game and season averages. Yet the average performances in overtime of both groups do not differ significantly (between-subject comparison). We conclude that success in crucial situations leads to lower subsequent individual performance. Psychological explanations for this phenomenon, e.g. the role of overconfidence, are discussed. We argue that our findings can be transferred to behavior after success or failure in business settings since we have distinct identifications of performance and responsibility: the observed overtimes are clear and immediate outcomes of the last shots of our analyzed players; without their success or failure, the game would have been over after regular time
Identification of NAD-RNA species and ADPR-RNA decapping in Archaea
No full textNAD is a coenzyme central tometabolism that also serves as a 5′-terminal cap
for bacterial and eukaryotic transcripts. Thermal degradation of NAD can
generate nicotinamide and ADP-ribose (ADPR). Here, we use LC-MS/MS and
NAD captureSeq to detect and identify NAD-RNAs in the thermophilic model
archaeon Sulfolobus acidocaldarius and in the halophilic mesophile Haloferax
volcanii. None of the four Nudix proteins of S. acidocaldarius catalyze NADRNA
decapping in vitro, but one of the proteins (Saci_NudT5) promotes ADPRRNA
decapping. NAD-RNAs are converted into ADPR-RNAs, which we detect in
S. acidocaldarius total RNA. Deletion of the gene encoding the 5′−3′ exonuclease
Saci-aCPSF2 leads to a 4.5-fold increase in NAD-RNA levels.We propose
that the incorporation of NAD into RNA acts as a degradation marker for SaciaCPSF2.
In contrast, ADPR-RNA is processed by Saci_NudT5 into 5′-p-RNAs,
providing another layer of regulation for RNA turnover in archaeal cells.Gefördert durch den Open-Access-Publikationsfonds der UB Marburg
Citizens‘ support for inter-municipal cooperation: evidence from a survey in the German state of Hessen
No full textInter-municipal cooperation (IMC) is promoted as a way in which small, fiscally weak munic-ipalities can cope with intensified interregional competition and demographic change. We pro-vide first evidence on citizens’ support for IMC using survey data from rural Germany. We cover different fields of public services and find the support for IMC to be lower for services where IMC implies intensified interaction with citizens from neighboring municipalities. The main research question asks whether citizens’ support for IMC is larger in municipalities that can – by the logic of normative theory – expect higher net benefits from IMC. The answer is largely negative: While support for IMC decreases in the travel-time to neighboring municipal-ities, we do not find the support for IMC to be higher among citizens in small and/or fiscally weak municipalities, nor do we find the available of suitable partners to matter. At the same time, citizens’ policy preferences strongly depends on individual-level factors. Believing that IMC reduces citizens’ influence and control reduces the support for IMC substantially. Trust in local politicians and a high degree of emotional attachment to the home municipality reduce citizens’ support for IMC
Exclusionary Practices in Two-Sided Markets: The Effect of Radius Clauses on Competition Between Shopping Centers
No full textThis paper analyzes exclusionary conduct of platforms in two-sided markets. Motivated by recent antitrust cases against shopping centers introducing radius restrictions on their tenants, we provide a discussion of the likely positive and normative effects of exclusivity clauses, which prevent tenants from opening outlets in other shopping centers covered by the clause. In a standard two-sided market model with two competing shopping centers, we analyze incentives to introduce exclusivity clauses and the likely effects on social welfare. We show that exclusivity agreements are especially profitable for shopping centers and detrimental to social welfare if competition is intense between the two shopping centers. We argue that the focus of courts on market definition is misplaced in markets determined by competitive bottlenecks