198,125 research outputs found
My friend Alex M\"uller
No full textAlex, the main discoverer of high Tc superconductivity, was also a dear
friend. Here I offer a few frank anecdotes, possibly inaccurate in some details
but heartfelt and accurate in the substance, as a personal tribute to our
friendship.Comment: To appear on Physica C Superconductivity -- K. Alex M\"uller memorial
issu
Masanes-Galley-M\"uller and the State-Update Postulate
No full textMasanes, Galley and M\"uller claim to have derived a unique rule for quantum
state update consequent upon a measurement outcome. Upon closer examination,
their proof implicitly assumes its first step, namely that the state-update
rule is linear.Comment: 6 pages; v2: added reply to their reply to my comment, trying to
avoid talking past one anothe
Alex M\"uller, the High-Tc Field-Effect Transistor and Electric-Field Gated Quantum Materials
No full textAlex M\"uller and Georg Bednorz are widely recognized for their trailblazing
discovery of high-temperature superconductivity and their groundbreaking
research on SrTiO3. In comparison, their substantial contributions to inventing
the high-Tc superconducting field-effect transistor remain relatively unknown.
Nevertheless, their efforts were crucial in developing the electric field
effect into a valuable tool for studying a broad spectrum of complex materials.
This article provides a brief overview of these developments and of the current
status in this field, with a particular focus on Alex M\"uller's visionary role
in advancing the field following the discovery of high-temperature
superconductivity.Comment: Contribution to a planned memorial issue for K.A. M\"uller by Physica
K. Alex M\"uller and his important role in ferroelectricity
No full textIn this review we concentrate on the work of K. Alex M\"uller in connection
with his activities on oxide perovskites and ferroelectrics which were central
to his research career long before he successfully discovered the first high
temperature superconductor (HTSC) together with J. G. Bednorz in 1986. Not
accidentally, but taking his long experience in perovskite ferroelectrics into
account, the first HTSC was an oxide perovskite which had never been considered
before to be superconducting.Comment: 8 pages, 4 figure
Sex ratio variation and sex determination in the mallee dragon Ctenophorus fordi.
No full textRecent evidence suggests that many Australian agamids show temperature-dependent sex determination (TSD) with variation in sex determining mechanisms among closely related taxa. However, as shown in other vertebrates, sex ratios can also be influenced by genetic or phenotypic differences among females in their propensity to produce sons or daughters, and these influences might confound any thermal effects of incubation per se. To address these issues, we investigated the determinants of sex ratios in the mallee dragon Ctenophorus fordi, together with a detailed analysis of karyotypes. There was no detectable variation in sex ratios arising from variation among females, clutches or incubation temperatures, which might indicate genetic sex determination for this species. However, there was no evidence of cytologically distinct sex chromosomes using standard banding techniques. The sex ratio pattern in C. fordi strongly contrasts with the results for the congener Ctenophorus pictus, where sex ratios show variation among females. Thus, Australian agamids offer promising opportunities to address fundamental issues in sex ratio biology
K. Alex M\"uller: Science between ferroelectricity and superconductivity
No full textK. Alex M\"uller started his scientific career in 1958 when he was about
thirty-one years old. After his wife passed away and being in his nineties, his
interest in physics gradually faded. In those years shortly before he passed
away, on January 9, 2023, he was no longer interested in superconductivity or
ferroelectricity, he had become essentially devoted to philosophy and
psychology. It is of note that altogether his research in physics comprised
sixty years of activity. Almost in the middle of this period, he was awarded
the Nobel Prize in Physics for the discovery of high-temperature
superconductivity in ceramic copper oxides in 1987. This discovery made him
truly famous. While most researchers are familiar with his Nobel Prize work,
many are not aware of the fact that K. Alex M\"uller was already an acclaimed
scientist before that and highly respected in the field of perovskite oxides,
ferroelectricity, structural phase transitions, Jahn-Teller physics, electron
paramagnetic resonance (EPR) and, especially so in the properties of SrTiO3.Comment: 13 pages, 7 figures, 1 tabl
A Cheeger-M\"uller theorem for manifolds with wedge singularities
No full textWe study the spectrum and heat kernel of the Hodge Laplacian with
coefficients in a flat bundle on a closed manifold degenerating to a manifold
with wedge singularities. Provided the Hodge Laplacians in the fibers of the
wedge have an appropriate spectral gap, we give uniform constructions of the
resolvent and heat kernel on suitable manifolds with corners. When the wedge
manifold and the base of the wedge are odd dimensional, this is used to obtain
a Cheeger-M\"uller theorem relating analytic torsion with the Reidemeister
torsion of the natural compactification by a manifold with boundary.Comment: 74 pages, 7 figures, small modification
Consistent sex ratio bias of individual female dragon lizards.
No full textSex ratio evolution relies on genetic variation in either the phenotypic traits that influence sex ratios or sex-determining mechanisms. However, consistent variation among females in offspring sex ratio is rarely investigated. Here, we show that female painted dragons (Ctenophorus pictus) have highly repeatable sex ratios among clutches within years. A consistent effect of female identity could represent stable phenotypic differences among females or genetic variation in sex-determining mechanisms. Sex ratios were not correlated with female size, body condition or coloration. Furthermore, sex ratios were not influenced by incubation temperature. However, the variation among females resulted in female-biased mean population sex ratios at hatching both within and among years
How to Swoop and Grasp like a Bird with a Passive Claw for High-Speed Grasping
No full textThis dataset corresponds to the publication:
"How to Swoop and Grasp like a Bird with a Passive Claw for High-Speed Grasping" W. Stewart, E. Ajanic, M. M¨uller, and D. Floreano. Transactions on Mechatronics
Human introductions create opportunities for intra-specific hybridization in an alien lizard
No full textIntroduction of individuals from multiple sources could create opportunities for hybridization between previously isolated lineages, which may impact on the invasion process. Identifying the phylogeographic origin of introduced populations is therefore an important task to further test the causes and consequences of human-mediated translocations. The common wall lizard (Podarcis muralis) shows a strong phylogeographic structure as a result of past isolation in glacial refugia, but it has also been commonly introduced outside of its native range. Here we analysed 655 base pairs (bp) of the cytochrome b sequence from 507 individuals from 23 introduced populations of P. muralis in England. We identified 12 unique haplotypes in the introduced populations that were nested into five native geographically distinct clades with genetic divergences ranging from 2.1 to 5.7 %. Multiple clade origin was common within populations, with a maximum of three different haplotype clades being represented within a single population. The genetic data are consistent with a scenario whereby initial establishment was a result of translocation of animals from their native range, whereas more recent establishment (i.e. since the mid-1980s) is the result of translocations of animals from previously established non-native populations. However, this requires further study. Overall, our results show that human introductions have created substantial opportunities for hybridization between genetically and phenotypically distinct lineages, which may have important consequences for the establishment success and long-term viability of introduced wall lizard populations
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