Tactile information improves visual object discrimination in kea, Nestor notabilis, and capuchin monkeys, Sapajus spp.

In comparative visual cognition research, the influence of information acquired by nonvisual senses has received little attention. Systematic studies focusing on how the integration of information from sight and touch can affect animal perception are sparse. Here, we investigated whether tactile input improves visual discrimination ability of a bird, the kea, and capuchin monkeys, two species with acute vision, and known for their tendency to handle objects. To this end, we assessed whether, at the attainment of a criterion, accuracy and/or learning speed in the visual modality were enhanced by haptic (i.e. active tactile) exploration of an object. Subjects were trained to select the positive stimulus between two cylinders of the same shape and size, but with different surface structures. In the Sight condition, one pair of cylinders was inserted into transparent Plexiglas tubes. This prevented animals from haptically perceiving the objects' surfaces. In the Sight and Touch condition, one pair of cylinders was not inserted into transparent Plexiglas tubes. This allowed the subjects to perceive the objects' surfaces both visually and haptically. We found that both kea and capuchins (1) showed comparable levels of accuracy at the attainment of the learning criterion in both conditions, but (2) required fewer trials to achieve the criterion in the Sight and Touch condition. Moreover, this study showed that both kea and capuchins can integrate information acquired by the visual and tactile modalities. To our knowledge, this represents the first evidence of visuotactile integration in a bird species. Overall, our findings demonstrate that the acquisition of tactile information while manipulating objects facilitates visual discrimination of objects in two phylogenetically distant species

Single spin probe of Many-Body Localization

We use an external spin as a dynamical probe of many body localization. The probe spin is coupled to an interacting and disordered environment described by a Heisenberg spin chain in a random field. The spin-chain environment can be tuned between a thermalizing delocalized phase and non-thermalizing localized phase, both in its ground- and high-energy states. We study the decoherence of the probe spin when it couples to the environment prepared in three states: the ground state, the infinite temperature state and a high energy N\'eel state. In the non-thermalizing many body localized regime, the coherence shows scaling behaviour in the disorder strength. The long-time dynamics of the probe spin shows a logarithmic dephasing in analogy with the logarithmic growth of entanglement entropy for a bi-partition of a many-body localized system. In summary, we show that decoherence of the probe spin provides clear signatures of many-body localization.Comment: 5 pages, 4 figure

High temperature thermal conductivity of 2-leg spin-1/2 ladders

Based on numerical simulations, a study of the high temperature, finite frequency, thermal conductivity $\kappa(\omega)$ of spin-1/2 ladders is presented. The exact diagonalization and a novel Lanczos technique are employed.The conductivity spectra, analyzed as a function of rung coupling, point to a non-diverging $dc-$limit but to an unconventional low frequency behavior. The results are discussed with perspective recent experiments indicating a significant magnetic contribution to the energy transport in quasi-one dimensional compounds.Comment: 4 pages, 4 figure

Mapping out the time-evolution of exoplanet processes

There are many competing theories and models describing the formation, migration and evolution of exoplanet systems. As both the precision with which we can characterize exoplanets and their host stars, and the number of systems for which we can make such a characterization increase, we begin to see pathways forward for validating these theories. In this white paper we identify predicted, observable correlations that are accessible in the near future, particularly trends in exoplanet populations, radii, orbits and atmospheres with host star age. By compiling a statistically significant sample of well-characterized exoplanets with precisely measured ages, we should be able to begin identifying the dominant processes governing the time-evolution of exoplanet systems.Comment: Astro2020 white pape

Excitation of equatorial Kelvin and Yanai waves by tropical cyclones in an ocean general circulation model

Tropical cyclones (TCs) actively contribute to the dynamics of Earth's coupled climate system. They influence oceanic mixing rates, upper-ocean heat content, and air–sea fluxes, with implications for atmosphere and ocean dynamics on multiple spatial and temporal scales. Using an ocean general circulation model with modified surface wind forcing, we explore how TC winds can excite equatorial ocean waves in the tropical Pacific. We highlight a situation where three successive TCs in the western North Pacific region, corresponding to events in 2003, excite a combination of Kelvin and Yanai waves in the equatorial Pacific. The resultant thermocline adjustment significantly modifies the thermal structure of the upper equatorial Pacific and leads to eastward zonal heat transport. Observations of upper-ocean temperature by the Tropical Atmosphere Ocean (TAO) buoy array and sea-level height anomalies using altimetry reveal wave passage during the same time period with similar properties to the modeled wave, although our idealized model methodology disallows precise identification of the TC forcing with the observed waves. Results indicate that direct oceanographic forcing by TCs may be important for understanding the spectrum of equatorial ocean waves, thus remotely influencing tropical mixing and surface energy budgets. Because equatorial Kelvin waves are closely linked to interannual variability in the tropical Pacific, these findings also suggest TC wind forcing may influence the timing and amplitude of El Niño events

Asteroseismic classification of stellar populations among 13000 red giants observed by Kepler

Of the more than 150000 targets followed by the Kepler Mission, about 10% were selected as red giants. Due to their high scientific value, in particular for Galaxy population studies and stellar structure and evolution, their Kepler light curves were made public in late 2011. More than 13000 (over 85%) of these stars show intrinsic flux variability caused by solar-like oscillations making them ideal for large scale asteroseismic investigations. We automatically extracted individual frequencies and measured the period spacings of the dipole modes in nearly every red giant. These measurements naturally classify the stars into various populations, such as the red giant branch, the low-mass (M/Msol 1.8) secondary clump. The period spacings also reveal that a large fraction of the stars show rotationally induced frequency splittings. This sample of stars will undoubtedly provide an extremely valuable source for studying the stellar population in the direction of the Kepler field, in particular when combined with complementary spectroscopic surveys.Comment: 6 page, 5 figures, accepted by ApJ

Meta-analysis discovery of tissue-specific DNA sequence motifs from mammalian gene expression data

BACKGROUND: A key step in the regulation of gene expression is the sequence-specific binding of transcription factors (TFs) to their DNA recognition sites. However, elucidating TF binding site (TFBS) motifs in higher eukaryotes has been challenging, even when employing cross-species sequence conservation. We hypothesized that for human and mouse, many orthologous genes expressed in a similarly tissue-specific manner in both human and mouse gene expression data, are likely to be co-regulated by orthologous TFs that bind to DNA sequence motifs present within noncoding sequence conserved between these genomes. RESULTS: We performed automated motif searching and merging across four different motif finding algorithms, followed by filtering of the resulting motifs for those that contain blocks of information content. Applying this motif finding strategy to conserved noncoding regions surrounding co-expressed tissue-specific human genes allowed us to discover both previously known, and many novel candidate, regulatory DNA motifs in all 18 tissue-specific expression clusters that we examined. For previously known TFBS motifs, we observed that if a TF was expressed in the specified tissue of interest, then in most cases we identified a motif that matched its TRANSFAC motif; conversely, of all those discovered motifs that matched TRANSFAC motifs, most of the corresponding TF transcripts were expressed in the tissue(s) corresponding to the expression cluster for which the motif was found. CONCLUSION: Our results indicate that the integration of the results from multiple motif finding tools identifies and ranks highly more known and novel motifs than does the use of just one of these tools. In addition, we believe that our simultaneous enrichment strategies helped to identify likely human cis regulatory elements. A number of the discovered motifs may correspond to novel binding site motifs for as yet uncharacterized tissue-specific TFs. We expect this strategy to be useful for identifying motifs in other metazoan genomes

Perspectives on the Missiological Legacy of Martin Luther and the Protestant Reformation

Upon the occasion of the 500th anniversary Martin Luther’s publication of his 95 theses, this composite article brings together five perspectives on the missiological legacy of the reformer and the subsequent Protestant Reformation. The blend of voices makes clear that Luther and the subsequent Protestant Reformation do not have a simple missiological legacy but rather various legacies: theological, ecclesiological, political, and practical; some of which co-exist, and even collide, in the same ecclesiastical community. The scandalous legacy of a splintered and splintering church remains. Yet, demonstrations of mutual recognition, reciprocal respect, and genuine fellowship can be found in certain missiological circles