896 research outputs found
Principal Components of Short-term Variability in Venus' UV Albedo
We explore the dominant modes of variability in the observed albedo at the
cloud tops of Venus using the Akatsuki UVI 283-nm and 365-nm observations,
which are sensitive to SO2 and unknown UV absorber distributions respectively,
over the period Dec 2016 to May 2018. The observations consist of images of the
dayside of Venus, most often observed at intervals of 2 hours, but interspersed
with longer gaps. The orbit of the spacecraft does not allow for continuous
observation of the full dayside, and the unobserved regions cause significant
gaps in the datasets. Each dataset is subdivided into three subsets for three
observing periods, the unobserved data are interpolated and each subset is then
subjected to a principal component analysis (PCA) to find six oscillating
patterns in the albedo. Principal components in all three periods show similar
morphologies at 283-nm but are much more variable at 365-nm. Some spatial
patterns and the time scales of these modes correspond to well known physical
processes in the atmosphere of Venus such as the ~4 day Kelvin wave, 5 day
Rossby waves and the overturning circulation, while others defy a simple
explanation. We also a find a hemispheric mode that is not well understood and
discuss its implications.Comment: 9 pages, 6 figures, accepted in A&
Modulation of physical understanding by common marmosets (Callithrix jacchus)
The understanding of physical causality in common marmosets was tested using support problems in which a pair of sheets was presented to determine whether subjects would choose the sheet that had a food item on it (i.e., the sheet was supporting the food item). In two experiments, the conditions were manipulated in terms of the length of the sheet, the distance between the sheet and the food item, the presence of a gap separating the two sheets, and the size of the food item. In Experiment 1, the marmosets had difficulty rejecting an irretrievable food item when it was located closer to them than a retrievable item. Although their performance was strongly affected by the size of the irretrievable food item, they quickly learned to reject that alternative. In contrast, no improvement was found when one sheet was divided into two pieces such that the food item could not be retrieved when its near side was pulled. A similar response tendency was observed in Experiment 2, in which the effects of the large food item were examined in three different conditions. Thus, common marmosets were influenced by the perceptual features of the food in solving the support problems, as are other non-human primates. In addition, they consistently failed to appreciate the presence of a gap and, therefore, failed to reject the distracter alternative. However, all animals rapidly learned that the size of the food item was an irrelevant variable, and some showed an elementary conceptual understanding of support. These findings suggest that marmosets’ physical understanding may improve with experience
Quantum magnonics: magnon meets superconducting qubit
The techniques of microwave quantum optics are applied to collective spin
excitations in a macroscopic sphere of ferromagnetic insulator. We demonstrate,
in the single-magnon limit, strong coupling between a magnetostatic mode in the
sphere and a microwave cavity mode. Moreover, we introduce a superconducting
qubit in the cavity and couple the qubit with the magnon excitation via the
virtual photon excitation. We observe the magnon-vacuum-induced Rabi splitting.
The hybrid quantum system enables generation and characterization of
non-classical quantum states of magnons.Comment: 10 pages, 6 figure
High expression of a novel carnitine palmitoyltransferase I like protein in rat brown adipose tissue and heart: isolation and characterization of its cDNA clone
AbstractTo characterize energy metabolism in rat brown adipose tissue (BAT), we carried out differential screening of a cDNA library of BAT with a cDNA probe of white adipose tissue (WAT) and isolated one cDNA clone. It contained a single open reading frame of 2,316 bases which encodes a protein of 88.2 kDa. The predicted amino acid sequence showed the highest homology (62.6%) with that of rat carnitine palmitoyltransferase I (CPTI). The transcript corresponding to this cDNA was found to be abundantly expressed in BAT and heart. Therefore, the isolated clone is concluded to encode a CPTI like protein expressed in BAT and heart
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