67 research outputs found
Why Some Interfaces Cannot be Sharp
A central goal of modern materials physics and nanoscience is control of
materials and their interfaces to atomic dimensions. For interfaces between
polar and non-polar layers, this goal is thwarted by a polar catastrophe that
forces an interfacial reconstruction. In traditional semiconductors this
reconstruction is achieved by an atomic disordering and stoichiometry change at
the interface, but in multivalent oxides a new option is available: if the
electrons can move, the atoms don`t have to. Using atomic-scale electron energy
loss spectroscopy we find that there is a fundamental asymmetry between
ionically and electronically compensated interfaces, both in interfacial
sharpness and carrier density. This suggests a general strategy to design sharp
interfaces, remove interfacial screening charges, control the band offset, and
hence dramatically improving the performance of oxide devices.Comment: 12 pages of text, 6 figure
Mechanisms and in vivo functions of contact inhibition of locomotion
Contact inhibition of locomotion (CIL) is a process whereby a cell ceases motility or
changes its trajectory upon collision with another cell. CIL was initially characterized more than
half a century ago and became a widely studied model system to understand how cells migrate
and dynamically interact. Although CIL fell from interest for several decades, the scientific
community has recently rediscovered this process. We are now beginning to understand the
precise steps of this complex behaviour and to elucidate its regulatory components, including
receptors, polarity proteins and cytoskeletal elements. Furthermore, this process is no longer just
in vitro phenomenology; we now know from several different in vivo models that CIL is essential
for embryogenesis and in governing behaviours such as cell dispersion, boundary formation and
collective cell migration. In addition, changes in CIL responses have been associated with other
physiological processes, such as cancer cell dissemination during metastasis
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Motives and comprehension in a public goods game with induced emotions
This study analyses the sensitivity of public goods contributions through the lens of psychological motives. We report the results of a public goods experiment in which subjects were induced with the motives of care and anger through autobiographical recall. Subjects' preferences, beliefs, and perceptions under each motive are compared with those of subjects experiencing a neutral autobiographical recall control condition. We find, but only for those subjects with the highest comprehension of the game, that care elicits significantly higher contributions than anger, with the control treatment in between. This positive influence of the care motive on unconditional giving is accounted for partly by preferences for giving and partly by the beliefs concerning greater contributions by others. Anger also affects attention to own and other's payoffs (using mouse tracking) and perceptions of the game's incentive structure (cooperative or competitive)
Identification of a General O-linked Protein Glycosylation System in Acinetobacter baumannii and Its Role in Virulence and Biofilm Formation
Acinetobacter baumannii is an emerging cause of nosocomial infections. The isolation of strains resistant to multiple antibiotics is increasing at alarming rates. Although A. baumannii is considered as one of the more threatening “superbugs” for our healthcare system, little is known about the factors contributing to its pathogenesis. In this work we show that A. baumannii ATCC 17978 possesses an O-glycosylation system responsible for the glycosylation of multiple proteins. 2D-DIGE and mass spectrometry methods identified seven A. baumannii glycoproteins, of yet unknown function. The glycan structure was determined using a combination of MS and NMR techniques and consists of a branched pentasaccharide containing N-acetylgalactosamine, glucose, galactose, N-acetylglucosamine, and a derivative of glucuronic acid. A glycosylation deficient strain was generated by homologous recombination. This strain did not show any growth defects, but exhibited a severely diminished capacity to generate biofilms. Disruption of the glycosylation machinery also resulted in reduced virulence in two infection models, the amoebae Dictyostelium discoideum and the larvae of the insect Galleria mellonella, and reduced in vivo fitness in a mouse model of peritoneal sepsis. Despite A. baumannii genome plasticity, the O-glycosylation machinery appears to be present in all clinical isolates tested as well as in all of the genomes sequenced. This suggests the existence of a strong evolutionary pressure to retain this system. These results together indicate that O-glycosylation in A. baumannii is required for full virulence and therefore represents a novel target for the development of new antibiotics
Perceiving emotion in non-social targets: The effect of trait empathy on emotional contagion through art
Do individuals with and without depression value depression differently? And if so, why?
Exploring the relationship between governance mechanisms in healthcare and health workforce outcomes: a systematic review
Multi-criteria decision analysis with goal programming in engineering, management and social sciences: a state-of-the art review
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