Evolution of Insect Olfaction Hansson, Bill S.; Stensmyr, Marcus C.
Neuron (Cambridge, Mass.),
12/2011, Letnik:
72, Številka:
5
Journal Article
Recenzirano
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Neuroethology utilizes a wide range of multidisciplinary approaches to decipher neural correlates of natural behaviors associated with an animal's ecological niche. By placing emphasis on comparative ...analyses of adaptive and evolutionary trends across species, a neuroethological perspective is uniquely suited to uncovering general organizational and biological principles that shape the function and anatomy of the nervous system. In this review, we focus on the application of neuroethological principles in the study of insect olfaction and discuss how ecological environment and other selective pressures influence the development of insect olfactory neurobiology, not only informing our understanding of olfactory evolution but also providing broader insights into sensory processing.
Controlling the properties of semiconductor/metal interfaces is a powerful method for designing functionality and improving the performance of electrical devices. Recently ...semiconductor/superconductor hybrids have appeared as an important example where the atomic scale uniformity of the interface plays a key role in determining the quality of the induced superconducting gap. Here we present epitaxial growth of semiconductor-metal core-shell nanowires by molecular beam epitaxy, a method that provides a conceptually new route to controlled electrical contacting of nanostructures and the design of devices for specialized applications such as topological and gate-controlled superconducting electronics. Our materials of choice, InAs/Al grown with epitaxially matched single-plane interfaces, and alternative semiconductor/metal combinations allowing epitaxial interface matching in nanowires are discussed. We formulate the grain growth kinetics of the metal phase in general terms of continuum parameters and bicrystal symmetries. The method realizes the ultimate limit of uniform interfaces and seems to solve the soft-gap problem in superconducting hybrid structures.
We investigate zero-bias conductance peaks that arise from coalescing subgap Andreev states, consistent with emerging Majorana zero modes, in hybrid semiconductor-superconductor wires defined in a ...two-dimensional InAs/Al heterostructure using top-down lithography and gating. The measurements indicate a hard superconducting gap, ballistic tunneling contact, and in-plane critical fields up to 3 T. Top-down lithography allows complex geometries, branched structures, and straightforward scaling to multicomponent devices compared to structures made from assembled nanowires.
Flies, like all animals, need to find suitable and safe food. Because the principal food source for Drosophila melanogaster is yeast growing on fermenting fruit, flies need to distinguish fruit with ...safe yeast from yeast covered with toxic microbes. We identify a functionally segregated olfactory circuit in flies that is activated exclusively by geosmin. This microbial odorant constitutes an ecologically relevant stimulus that alerts flies to the presence of harmful microbes. Geosmin activates only a single class of sensory neurons expressing the olfactory receptor Or56a. These neurons target the DA2 glomerulus and connect to projection neurons that respond exclusively to geosmin. Activation of DA2 is sufficient and necessary for aversion, overrides input from other olfactory pathways, and inhibits positive chemotaxis, oviposition, and feeding. The geosmin detection system is a conserved feature in the genus Drosophila that provides flies with a sensitive, specific means of identifying unsuitable feeding and breeding sites.
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► Geosmin, the odor of mold, activates only olfactory sensory neurons expressing Or56a ► These neurons connect to projection neurons that respond exclusively to geosmin ► This circuit confers innate avoidance and, upon activation, overrides attraction ► This pathway is used by flies to detect harmful microbes that produce geosmin
A neuronal circuit that detects a volatile chemical released by toxic mold has been mapped in fly brain. Activation of this evolutionarily conserved circuit overrides a number of innate behaviors such as attraction to other odors and egg laying on substrates, revealing the underlying mechanisms of hard-wired and selectively advantageous avoidance of harmful bacteria in the environment.
We investigate the deflection of light by a rotating global monopole spacetime and a rotating Letelier spacetime in the weak deflection approximation. To this end, we apply the Gauss-Bonnet theorem ...to the corresponding osculating optical geometries and show that the deflection of light increases in each spacetime due to the presence of the global monopole parameter and the string cloud parameter, respectively. The results obtained for the deflection angle in the equatorial plane generalize known results for the corresponding nonrotating global monopole and Letelier spacetimes as well as the Kerr solution.
The concept of cell signaling in the context of nonenzyme-assisted protein modifications by reactive electrophilic and oxidative species, broadly known as redox signaling, is a uniquely complex topic ...that has been approached from numerous different and multidisciplinary angles. Our Review reflects on five aspects critical for understanding how nature harnesses these noncanonical post-translational modifications to coordinate distinct cellular activities: (1) specific players and their generation, (2) physicochemical properties, (3) mechanisms of action, (4) methods of interrogation, and (5) functional roles in health and disease. Emphasis is primarily placed on the latest progress in the field, but several aspects of classical work likely forgotten/lost are also recollected. For researchers with interests in getting into the field, our Review is anticipated to function as a primer. For the expert, we aim to stimulate thought and discussion about fundamentals of redox signaling mechanisms and nuances of specificity/selectivity and timing in this sophisticated yet fascinating arena at the crossroads of chemistry and biology.
Schreckstoff (fear substance) is an alarm signal released by injured fish that induces a fear response. Its chemical nature has long been debated. A new study finds that zebrafish Schreckstoff is ...composed of at least three components, two of which elicit the fear response only in combination.
Schreckstoff (fear substance) is an alarm signal released by injured fish and inducing a fear response. Its chemical nature has long been debated. A new study finds that zebrafish Schreckstoff is composed of at least three components, two of which elicit the fear response only in combination.
Insect genomics: A lousy fly Stensmyr, Marcus C.
Current biology,
03/2024, Letnik:
34, Številka:
5
Journal Article
Recenzirano
The bee louse (Braula coeca) is a honeybee inquiline and a long-standing taxonomic mystery. A new study unravels their genomic architecture and shows that these enigmatic flies have evolved from ...scale insect-exploiting drosophilid ancestors and share genetic similarities with their honeybee hosts.
The bee louse (Braula coeca) is a honeybee inquiline and a long-standing taxonomic mystery. A new study unravels their genomic architecture and shows that these enigmatic flies have evolved from scale insect-exploiting drosophilid ancestors and share genetic similarities with their honeybee hosts.
Novel pathogenic coronaviruses - such as SARS-CoV and probably SARS-CoV-2 - arise by homologous recombination between co-infecting viruses in a single cell. Identifying possible sources of novel ...coronaviruses therefore requires identifying hosts of multiple coronaviruses; however, most coronavirus-host interactions remain unknown. Here, by deploying a meta-ensemble of similarity learners from three complementary perspectives (viral, mammalian and network), we predict which mammals are hosts of multiple coronaviruses. We predict that there are 11.5-fold more coronavirus-host associations, over 30-fold more potential SARS-CoV-2 recombination hosts, and over 40-fold more host species with four or more different subgenera of coronaviruses than have been observed to date at >0.5 mean probability cut-off (2.4-, 4.25- and 9-fold, respectively, at >0.9821). Our results demonstrate the large underappreciation of the potential scale of novel coronavirus generation in wild and domesticated animals. We identify high-risk species for coronavirus surveillance.
We introduce a hybrid qubit based on a semiconductor nanowire with an epitaxially grown superconductor layer. Josephson energy of the transmonlike device ("gatemon") is controlled by an electrostatic ...gate that depletes carriers in a semiconducting weak link region. Strong coupling to an on-chip microwave cavity and coherent qubit control via gate voltage pulses is demonstrated, yielding reasonably long relaxation times (~0.8 μs) and dephasing times (~1 μs), exceeding gate operation times by 2 orders of magnitude, in these first-generation devices. Because qubit control relies on voltages rather than fluxes, dissipation in resistive control lines is reduced, screening reduces cross talk, and the absence of flux control allows operation in a magnetic field, relevant for topological quantum information.
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