University of Konstanz

About: University of Konstanz is a education organization based out in Konstanz, Baden-Württemberg, Germany. It is known for research contribution in the topics: Population & Membrane. The organization has 12115 authors who have published 27401 publications receiving 951162 citations. The organization is also known as: University of Constance & Universität Konstanz.

Diversity of Ferrous Iron-Oxidizing, Nitrate-Reducing Bacteria and their Involvement in Oxygen-Independent Iron Cycling

Abstract: In previous studies, three different strains (BrG1, BrG2, and BrG3) of ferrous iron-oxidizing, nitrate-reducing bacteria were obtained from freshwater sediments. All three strains were facultative anaerobes and utilized a variety of organic substrates and molecular hydrogen with nitrate as electron acceptor. In this study, analyses of 16S rDNA sequences showed that strain BrG1 was affiliated with the genus Acidovorax, strain BrG2 with the genus Aquabacterium, and strain BrG3 with the genus Thermomonas. Previously, bacteria similar to these three strains were detected with molecular techniques in MPN dilution series for ferrous iron-oxidizing, nitrate-reducing bacteria inoculated with different freshwater sediment samples. In the present study, further molecular analyses of these MPN cultures indicated that the ability to oxidize ferrous iron with nitrate is widespread amongst the Proteobacteria and may also be found among the Gram-positive bacteria with high GC content of DNA. Nitrate-reducing bacteria ox...

Boredom and academic achievement: Testing a model of reciprocal causation

Abstract: A theoretical model linking boredom and academic achievement is proposed. Based on Pekrun’s (2006) control-value theory of achievement emotions, the model posits that boredom and achievement reciprocally influence each other over time. Data from a longitudinal study with college students (N = 424) were used to examine the hypothesized effects. The study involved 5 assessments of students’ boredom and test performance during a university course spanning an entire academic year. Structural equation modeling was used to examine effects of boredom on achievement, and vice versa. The results show that boredom had consistently negative effects on subsequent performance, and performance had consistently negative effects on subsequent boredom, while controlling for students’ gender, age, interest, intrinsic motivation, and prior achievement. These results provide robust evidence for the proposed links between boredom and achievement and support systems-theoretical perspectives on the dynamics of emotions and achievement. From a broader educational perspective, the findings imply that researchers and practitioners alike should focus attention on boredom as an important, yet often overlooked, academic emotion.

Anodal Transcranial Direct Current Stimulation Temporarily Reverses Age-Associated Cognitive Decline and Functional Brain Activity Changes

Abstract: The rising proportion of elderly people worldwide will yield an increased incidence of age-associated cognitive impairments, imposing major burdens on societies Consequently, growing interest emerged to evaluate new strategies to delay or counteract cognitive decline in aging Here, we assessed immediate effects of anodal transcranial direct current stimulation (atDCS) on cognition and previously described detrimental changes in brain activity attributable to aging Twenty healthy elderly adults were assessed in a crossover sham-controlled design using functional magnetic resonance imaging (fMRI) and concurrent transcranial DCS administered to the left inferior frontal gyrus Effects on performance and task-related brain activity were evaluated during overt semantic word generation, a task that is negatively affected by advanced age Task-absent resting-state fMRI (RS-fMRI) assessed atDCS-induced changes at the network level independent of performance Twenty matched younger adults served as controls During sham stimulation, task-related fMRI demonstrated that enhanced bilateral prefrontal activity in older adults was associated with reduced performance RS-fMRI revealed enhanced anterior and reduced posterior functional brain connectivity atDCS significantly improved performance in older adults up to the level of younger controls; significantly reduced task-related hyperactivity in bilateral prefrontal cortices, the anterior cingulate gyrus, and the precuneus; and induced a more “youth-like” connectivity pattern during RS-fMRI Our results provide converging evidence from behavioral analysis and two independent functional imaging paradigms that a single session of atDCS can temporarily reverse nonbeneficial effects of aging on cognition and brain activity and connectivity These findings may translate into novel treatments to ameliorate cognitive decline in normal aging in the future