371 research outputs found
How stressful are economic competitions in the lab? An investigation with physiological measures
Competition is ubiquitous in economic life. Yet, negative consequences of competitive environments have been reported and everyday experience suggests that competitive situations can be very stressful. It is, however, an open question whether or not economic competitions in the laboratory indeed elicit physiological stress reactions. Our study examined the subjectively perceived stress and the physiological changes induced by a well-established economic laboratory competition paradigm (first used in Niederle and Vesterlund 2007) in a mixed-gender sample of
105 healthy participants. A mental arithmetic task was performed first under a piece rate (i.e., non-competitive) payment scheme and afterwards under a tournament condition. In a third round, participants decided how to be paid (i.e., piece rate or tournament). Our results indicate that compared to a control group, which performed only the non-competitive condition, the competitive game condition indeed elicited subjective and physiological reactions that are indicative of mild stress. Furthermore, reactions that are thought to reflect an active coping style were related to the self-selection into competition in the third round of the game. We speculate that real-life economic competitions might be even stronger stressors and the way how people cope with this kind of stress might be related to competitiveness in real-life economic contexts
Early detection of myocardial involvement in idiopathic inflammatory myopathies detected by cardiac magnetic resonance imaging
Teaching Method as a Determinant of Student Attitude
The purpose of this study is to assess the effect on student attitude with respect to using a hands-on teaching method in the elementary school, but limiting hands-on experience in the middle school. The primary question addressed is this: do students' attitudes towards science decline in middle school when hands-on science methods are used less frequently?
Student attitudes of grades three, five, seven, and eight are compared. Male and female students from two districts with presently two different approaches to teaching science are subjects of this study. An attitudinal survey comparing student attitude as it develops from grades three to eight was used.
This study finds that student attitude of students consistently exposed to a hands-on teaching methods in grades three through eight do not decrease in seventh and eighth grade as students whose middle school teachers limit hands-on teaching and learning experience. This study concludes that once hands-on teaching methods are employed in a district at the elementary school, it is imperative to continue usage of hands-on teaching methods at all grade levels.SUNY BrockportEducation and Human DevelopmentMaster of Science in Education (MSEd)Education and Human Development Master's These
COMT Val(158)Met genotypes differentially influence subgenual cingulate functional connectivity in healthy females
Brain imaging studies have cons stently shown subgenual Anterior Cingulate Cortical (sgACC) involvement in emotion processing. catechol-O-methyltransferase (COMT) Val(158) and Met(158) polymorphisms may influence such emotional brain processes in specific ways. Given that resting-state fMRI (rsfMRI) may increase our understanding on brain functioning, we integrated genetic and rsfMRI data and focused on sgACC functional connections. No studies have yet investigated the influence of the COMT Val(158)Met polymorphism (rs4680) on sgACC resting-state functional connectivity (rsFC) in healthy individuals. A homogeneous group of 61 Caucasian right-handed healthy female university students, all within the same age range, underwent isfMRI. Compared to Met158 homozygotes, Val(158) allele carriers displayed significantly stronger rsFC between the sgACC and the left parahippocampal gyrus, ventromedial parts of the inferior frontal gyrus (IFG), and the nucleus accumbens (NAc). On the other hand, compared to Val(158) homozygotes, we found in Met(158) allele carriers stronger sgACC rsFC with the medial frontal gyrus (MEG), more in particular the anterior parts of the medial orbitofrontal cortex. Although we did not use emotional or cognitive tasks, our sgACC rsFC results point to possible distinct differences in emotional and cognitive processes between Val(158) and Met(158) allele carriers. Hovvever, the exact nature of these directions remains to be determined
Untersuchung der DNA-bindenden Eigenschaften neuer Nukleobasen-gekoppelter Pyrrolcarboxamide, Combilexine und Hetaren[a]carbazol-Derivate: Validierung und Etablierung von in-vitro- und in-silico-Methoden
Da maligne Neoplasien durch Mutationen in Proto-Onko- und/oder Tumorsuppressorgenen ausgelöst werden, stellt die DNA eines der wichtigsten Targets für die Entwicklung neuer Zytostatika dar. Auch bei den im Arbeitskreis Pindur designten und synthetisier-ten Verbindungen der Nukleobasen-gekoppelten Pyrrolcarboxamid-, der Hetaren[a]carbazol- und der Combilexin-Reihe handelt es sich um DNA-Liganden mit potentiell antitumoraktiven Eigenschaf-ten. Die einen dualen Bindemodus aufweisenden Combilexine bestehen aus einem Interkalator (u. a. Naphthalimid, Acridon), der über einen Linker variabler Kettenlänge mit einer rinnenbin-denden, von Netropsin abgeleiteten Bispyrrol-, oder einer bioisosteren Imidazol-, Thiazol- oder Thiophen-pyrrolcarboxamid-struktur verknüpft ist. Das N-terminale Ende der Combilexine
wird von einer N,N-Dimethylaminopropyl- oder -ethyl-Seitenkette gebildet.
Die DNA-Affinitäten der Liganden wurden mittels Tm-Wert-Messung-en bestimmt. Diese Denaturierungsexperimente wurden sowohl mit poly(dAdT)2- als auch mit Thymus-DNA (~42% GC-Anteil) durchge-führt, um Aussagen zur Stärke und zur Sequenzselektivität der DNA-Bindung machen zu können. Des Weiteren wurden die Bindekon-stanten einiger ausgewählter Vertreter mit Hilfe des Ethidium-bromid-Verdrängungsassays ermittelt; einige Testverbindungen wurden zudem auf potentiell vorhandene, TOPO I-inhibierende Eigenschaften untersucht. Diese biochemischen und biophysika-lischen Tests wurden durch Molecular Modelling-Studien ergänzt, die die Berechnung von molekularen Eigenschaften, die Durch-führung von Konformerenanalysen und die Simulation von DNA-Ligand-Komplexen (Docking) umfassten. Durch Korrelation der in vitro-Befunde mit den in silico-Daten gelang es, vor allem für die Substanzklasse der Combilexine einige richtungweisende Struktur-
Wirkungsbeziehungen aufzustellen. So konnte gezeigt werden, dass die Einführung eines Imidazol-Rings in die rinnen-bindende Hetaren-pyrrolcarboxamid-Struktur der Combilexine aufgrund der H-Brücken-Akzeptor-Funktion des sp2-hybridisierten N-Atoms eine Verschiebung der Sequenzselektivität der DNA-Bindung von AT- zu GC-reichen Arealen der DNA bedingt. Zudem erwies sich ein C3-Linker für die Verknüpfung des Naphthalimids mit dem rinnenbindenden Strukturelement als am besten geeignet, während bei den Acridon-Derivaten die Verbindungen mit einem N-terminalen Buttersäure-Linker die höchste DNA-Affinität aufwiesen. Dies ist sehr wahrscheinlich auf die im Vergleich zum Naphthalimid-Molekül geringere y-Achsen-Ausdehnung (bzgl. eines x/y-Koordinatensystems) des Acridons zurückzuführen. Die ermittelten Struktur-Wirkungsbeziehungen können dazu herangezogen werden, das rationale Design neuer DNA-Liganden mit potentiell stärkerer DNA-Bindung zu optimieren.Malignant neoplasms are derived by mutations in proto-onco- and/or tumor suppressor genes. Therefore, DNA is one of the most important targets for the development oft anticancer drugs. The new derivatives of the nucleobase-conjugated pyrrole carboxamides, the hetarene[a]carbazoles and the combilexin series designed and synthesized in our group, belong to these DNA-targeting compounds with potential antitumor activity. The combilexins show a dual binding mechanism by consisting of an intercalating tricyclic system (e. g. naphthalimide, acridone), which is connected by a linker with varying length to a minor groove binding, Netropsin related bispyrrole or to a bioiso-steric imidazole-, thiazole- or thiophene-pyrrole carboxamide structure. The N-terminal end of the combilexins is built by an N,N-dimethylamino-propyl or -ethyl side chain.
To
estimate the DNA binding affinity of these ligands Tm-value measurements were performed. For these DNA thermal denaturation studies, poly(dAdT)2- as well as calf thymus DNA (~42% GC base pairs) were used to determine the strength and the sequence selectivity of drug binding. Besides, ethidiumbromide displace-ment assays were performed to determine the binding constants of some chosen derivatives and the possibly existing topoiso-merase I inhibition activity of the ligands was estimated by the help of a topoisomerase I relaxation assay. These biophysi-cal and biochemical experiments were supplemented by molecular modelling studies which include the calculation of molecular properties, the performance of conformational analysis and the simulation of DNA-ligand complexes (docking). The association of the computer-generated data with the experimental results made it possible to develop structure activity relationships, especially for the derivatives of the combilexin series. It could be shown for example, that
the usage of imidazole for the construction of the minor groove binding hetarene-pyrrole carboxamide structure results in a shift of the sequence selectivity of drug binding from AT- towards GC-rich areas of DNA because of the H-bond acceptor properties of the sp2-hybridised nitrogen atom. Besides, it has been proved that a C3-linker is the most suitable tether for the connection of a naphthalimide molecule with the groove binding element, while among the acridone derivatives the compounds with a C4-linker show the highest DNA binding affinities. This is probably attri-buted to the smaller y-axis-range of the acridone structure com-pared to the naphthalimide tricyclus. The estimated structure activity relationships should affect the synthetic design of more efficient antitumor drugs
Chronic toxicity of cadmium to Chironomus riparius (Diptera: Chironomidae) at different food levels.
Effect of eplerenone on extracellular cardiac matrix biomarkers in patients with acute ST-elevation myocardial infarction without heart failure: insights from the randomized double-blind REMINDER Study
Objective: Aldosterone stimulates cardiac collagen synthesis. Circulating biomarkers of collagen turnover provide a useful tool for the assessment of cardiac remodeling in patients with an acute myocardial infarction (MI). Methods: The REMINDER trial assessed the effect of eplerenone in patients with an acute ST-elevation Myocardial Infarction (STEMI) without known heart failure (HF), when initiated within 24 h of symptom onset. The primary outcome was almost totally (>90%) driven by natriuretic peptide (NP) thresholds after 1-month post-MI (it also included a composite of cardiovascular death or re-hospitalization or new onset HF or sustained ventricular tachycardia or fibrillation or LVEF ≤40% after 1-month post-MI). This secondary analysis aims to assess the extracellular matrix marker (ECMM) levels with regards to: (1) patients` characteristics; (2) determinants; (3) and eplerenone effect. Results: Serum levels of ECMM were measured in 526 (52%) of the 1012 patients enrolled in the REMINDER trial. Patients with procollagen type III N-terminal propeptide (PIIINP) above the median were older and had worse renal function (p < 0.05). Worse renal function was associated with increased levels of PIIINP (standardized β ≈ 0.20, p < 0.05). Eplerenone reduced PIIINP when the levels of this biomarker were above the median of 3.9 ng/mL (0.13 ± 1.48 vs. -0.37 ± 1.56 ng/mL, p = 0.008). Higher levels of PIIINP were independently associated with higher proportion of NP above the prespecified thresholds (HR = 1.95, 95% CI 1.16-3.29, p = 0.012). Conclusions: Eplerenone effectively reduces PIIINP levels when baseline values were above the median. Eplerenone may limit ECMM formation in post-MI without HF
INCREASED CADMIUM EXCRETION IN METAL-ADAPTED POPULATIONS OF THE MIDGE CHIRONOMUS RIPARIUS (DIPTERA)
Cardiac magnetic resonance imaging derived quantification of myocardial ischemia and scar improves risk stratification and patient management in stable coronary artery disease
Background: Quantification of myocardial ischemia and necrosis might ameliorate prognostic models and lead to improved patient management. However, no standardized consensus on how to assess and quantify these parameters has been established. The aim of this study was to quantify these variables by cardiac magnetic resonance imaging (CMR) and to establish possible incremental implications in cardiovascular risk prediction.
Methods: This study is a retrospective analysis of patients with known or suspected coronary artery disease (CAD) referred for adenosine perfusion CMR was performed. Myocardial ischemia and necrosis were assessed and quantified using an algorithm based on standard first-pass perfusion imaging and late gadolinium enhancement (LGE). The combined primary endpoint was defined as cardiac death, non-fatal myocardial infarction, and stroke.
Results: 845 consecutive patients were enrolled into the study. During the median follow-up of 3.64 [1.03; 10.46] years, 61 primary endpoints occurred. Patients with primary endpoint showed larger extent of ischemia (10.7 ± 12.25% vs. 3.73 ± 8.29%, p < 0.0001) and LGE (21.09 ± 15.11% vs. 17.73 ± 10.72%, p < 0.0001). A risk prediction model containing the extent of ischemia and LGE proved to be superior in comparison to all other models (χ² increase: from 39.678 to 56.676, integrated discrimination index: 0.3851, p = 0.0033, net reclassification index: 0.11516, p = 0.0071). The beneficial effect of revascularization tended to be higher in patients with greater extents of ischemia, though statistical significance was not reached.
Conclusions: Quantification of myocardial ischemia and LGE was shown to significantly improve existing risk prediction models and might thus lead to an improvement in patient management
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