University of Konstanz
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Suppression of coherent errors during entangling operations in NV centers in diamond
No full textWe consider entangling operations in a single nitrogen-vacancy center in diamond where the hyperfine-coupled nuclear spin qubits are addressed with radio frequency pulses conditioned on the state of the central electron spin. Limiting factors for the gate fidelity are coherent errors due to off-resonant driving of neighboring transitions in the dense, hyperfine-split energy spectrum of the defect and non-negligible perpendicular hyperfine tensor components that narrow the choice of 13C nuclear spin qubits. We address these issues by presenting protocols based on synchronization effects that allow for a complete suppression of both error sources in state-of-the-art CNOT gate schemes. This is possible by a suitable choice of parameter sets that incorporate the error into the scheme instead of avoiding it. These results contribute to the recent progress toward scalable quantum computation with defects in solids.publishe
Psychology of Planning
No full textPlanning has been studied in different fields of psychology, including cognitive, developmental, personality, social, and work and organizational research. This article looks at the planning process through the lens of motivation science, and asks the question, What kind of planning can help people reach their goals? We focus on the strategy of making if-then plans (also known as forming implementation intentions). We discuss what kinds of cognitive performance can be enhanced by if-then planning (e.g., attention control, prospective memory, executive functions, and decision making), and whether if-then planning may also benefit people's emotion control, their desired behavior change, and their pending social interactions. We point to the positive impacts of making if-then plans on thinking, feeling, and acting, and we list moderators pertaining to sample characteristics and features of the underlying goals and of the if-then plans themselves. Finally, the underlying processes of if-then planning effects are delineated in the hope of better understanding what kind of if-then planning might work best in promoting flexible but tenacious goal pursuit.update
Exercise Modalities for Improving Frontal Plane Knee and Foot Posture in Healthy Adults : A Systematic Review
No full textLower extremity misalignments increase the risk of chronic overload and acute injuries during sports and daily activities. Medial positioning of the knee and foot in the frontal plane is one of the key biomechanical risk factors associated with lower extremity injuries and pain. Different exercise interventions have been implemented to counteract misalignments. However, most studies have been conducted on clinical populations. Therefore, in this review, we aimed to assess the preventive effects of exercise interventions on frontal plane knee and foot posture in healthy individuals. Electronic databases (PubMed, Web of Science, PEDro) were systematically searched for original articles published between 2008 and 2024. This review included clinical trials on healthy adults (18–45 years) with or without lower extremity biomechanical misalignments, examining the effects of exercise interventions alone on knee and foot frontal plane biomechanics. Eligible studies reported at least one relevant frontal plane foot and knee biomechanical measure, such as knee valgus/abduction, medial knee displacement, foot pronation/eversion, or navicular drop. Studies involving non-exercise interventions, single-session protocols, and participants with neurological or spinal disorders, pain, or injury were excluded. A total of 35 articles with 1095 participants were included in this review. A total of 20 studies included individuals without a biomechanical misalignment, and 15 studies focused on individuals with a biomechanical misalignment. Mean values, standard deviations, and p-values were extracted from the included studies. Effect sizes and confidence intervals were then calculated to provide a quantitative presentation of the data. In conclusion, in healthy individuals without biomechanical misalignment, technique training and core muscles strengthening were most effective for improving knee valgus. Hip, core, and foot muscle strengthening reduced foot pronation in those with pronated feet, while short foot exercises improved foot positioning in individuals with flat feet. Combining lower extremity strengthening with knee position control training may reduce knee valgus in individuals with increased knee valgus.publishe
Time-averaged interference fringe analysis : A quantitative study of nanomembrane vibration dynamics
No full textIn this work, we present a method for characterizing nano/micro membrane resonators through the analysis of averaged interference fringes obtained from continuous light measurements. As the membrane vibrates, the interference fringes display blurring and contrast reduction, from which we establish a direct relationship between the vibration amplitude and the blurred area. This method offers a fast and straightforward approach to characterizing membrane vibrations and determining the dispersion relationship. Additionally, it enables the simultaneous extraction of multiple vibrational modes, providing mode numbers and phase differences that can be used to reconstruct dynamic vibration profiles. Its efficiency and broad frequency range make it particularly well-suited for high-frequency applications and rapid data collection.publishe
Is There a Timeless Truth for Good Arrangement of Paintings in Art Galleries and Museums? : An Experimental Investigation of the Barnes Collection
No full textThe Barnes Foundation is a traditional art collection and it is one of a kind as for the assorted hanging of the paintings. The sophisticated wall compositions by Albert Barnes were created as a tool for art education, and they have not been altered since 1951. Today, we are interested whether Barnes’ taste withstood the test of time. We asked participants in an online study to create their own hangings on five of the original gallery walls, and also tested whether beholders are able to identify a missing painting from a selection of suitable alternatives. Results show that Barnes’ motifs are reproduced by a significant number of participants and that experts produce more Barnes-like displays than naive participants. We conclude that Albert Barnes based his choices at least to some degree on universally valid visual aspects that are still understood today, especially by people trained in the visual domain.publishe
Gene expression comparisons between captive and wild shrew brains reveal captivity effects
No full textCompared with their free-ranging counterparts, wild animals in captivity experience different conditions with lasting physiological and behavioural effects. Although shifts in gene expression are expected to occur upstream of these phenotypes, we found no previous gene expression comparisons of captive versus free-ranging mammals. We assessed gene expression profiles of three brain regions (cortex, olfactory bulb and hippocampus) of wild shrews (Sorex araneus) compared with shrews kept in captivity for two months and undertook sample dropout to examine robustness given limited sample sizes. Consistent with captivity effects, we found hundreds of differentially expressed genes in all three brain regions, 104 overlapping across all three, that enriched pathways associated with neurodegenerative disease, oxidative phosphorylation and genes encoding ribosomal proteins. In the shrew, transcriptomic changes detected under captivity resemble responses in several human pathologies, including major depressive disorder and neurodegeneration. While interpretations of individual genes are tempered by small sample sizes, we propose captivity influences brain gene expression and function and can confound analyses of natural processes in wild individuals under captive conditions.publishe
Magnetic nutation : Transient separation of magnetization from its angular momentum
No full textFor nearly 90 years, precession and relaxation processes have been thought to dominate the magnetization dynamics. Only recently has it been considered that, on short time scales, an inertia-driven magnetization dynamics should become relevant, leading to additional nutation of the magnetization vector. Here, we trigger magnetic nutation via a sudden excitation of a thin Ni80Fe20 (Permalloy) film with an ultrashort optical pulse, that leads to an abrupt tilting of the effective field acting on the magnetic moments, separating the dynamics of the magnetization from that of its angular momentum. We investigate the resulting magnetization dynamics in the inertial regime experimentally by the time-resolved magneto-optical Kerr effect. We find a characteristic oscillation in the Kerr signal in the range ∼0.1 THz superimposed on the precessional oscillations with GHz frequencies. By comparison with atomistic spin dynamics simulations, we demonstrate that this observation cannot be explained by the well-known Landau-Lifshitz-Gilbert equation of motion but can be attributed to inertial contributions leading to nutation of the magnetization vector around its angular momentum. Hence, an optical and nonresonant excitation of inertial magnetization dynamics can trigger and control different magnetic processes, ranging from demagnetization via nutation to precession in a single device. These findings will have profound implications for the understanding of ultrafast spin dynamics and magnetization switching.publishe
Resolving Symbiodiniaceae Diversity Across Coral Microhabitats and Reef Niches
No full textDinoflagellates of the family Symbiodiniaceae are important symbionts of diverse marine animals and they also occupy different environmental niches on coral reefs. The link between diversity at ecosystem‐scale to microhabitats of Symbiodiniaceae within the coral holobiont is largely unknown. Using ITS2‐amplicon sequencing, we compared Symbiodiniaceae communities across four environments (seawater, near‐reef vs. distant sediments and turf algae) and two coral microhabitats (tissue, mucus) on a coral reef in the Red Sea. We found that coral and environmental habitats were both dominated by the genera Symbiodinium , Cladocopium and Durusdinium , but environmental habitats additionally harboured Fugacium , Gerakladium and Halluxium . Each environmental habitat harboured a distinct Symbiodiniaceae community. Nonetheless, 17 ITS2 sequences were shared among coral and environmental habitats and were also part of nearly half of the ITS2 type profiles in coral‐based communities. Tissues and mucus of 49 coral colonies from 17 genera had largely identical Symbiodiniaceae communities. Together with the large difference between environmental Symbiodiniaceae communities and those in the coral tissue and mucus, our results indicate a clear barrier between host‐associated and environmental Symbiodiniaceae communities marked by only few shared complete type profiles. Monitoring coral colonies after mucus sampling confirmed its suitability for long‐term monitoring of coral‐associated Symbiodiniaceae communities.publishe