In the olfactory bulb, odor representations by principal mitral cells are modulated by local inhibitory circuits. While dendrodendritic synapses between mitral and granule cells are typically thought ...to be a major source of this modulation, the contributions of other inhibitory neurons remain unclear. Here we demonstrate the functional properties of olfactory bulb parvalbumin-expressing interneurons (PV cells) and identify their important role in odor coding. Using paired recordings, we find that PV cells form reciprocal connections with the majority of nearby mitral cells, in contrast to the sparse connectivity between mitral and granule cells. In vivo calcium imaging in awake mice reveals that PV cells are broadly tuned to odors. Furthermore, selective PV cell inactivation enhances mitral cell responses in a linear fashion while maintaining mitral cell odor preferences. Thus, dense connections between mitral and PV cells underlie an inhibitory circuit poised to modulate the gain of olfactory bulb output.
•PV cells form dense reciprocal connections with most neighboring principal cells•PV cells show much broader odor-tuning properties compared to mitral or granule cells•Increase in respiration even without odors is a strong driver of PV cell activity•Inactivation experiments suggest that PV cells linearly control olfactory bulb output
Functions of neural circuits rely on inhibition provided by diverse types of inhibitory neurons. Kato et al. use paired recordings and in vivo two-photon calcium imaging to show that parvalbumin-expressing interneurons linearly control the output of the olfactory bulb.
Animals sense sounds through hierarchical neural pathways that ultimately reach higher-order cortices to extract complex acoustic features, such as vocalizations. Elucidating how spectrotemporal ...integration varies along the hierarchy from primary to higher-order auditory cortices is a crucial step in understanding this elaborate sensory computation. Here we used two-photon calcium imaging and two-tone stimuli with various frequency-timing combinations to compare spectrotemporal integration between primary (A1) and secondary (A2) auditory cortices in mice. Individual neurons showed mixed supralinear and sublinear integration in a frequency-timing combination-specific manner, and we found unique integration patterns in these two areas. Temporally asymmetric spectrotemporal integration in A1 neurons suggested their roles in discriminating frequency-modulated sweep directions. In contrast, temporally symmetric and coincidence-preferring integration in A2 neurons made them ideal spectral integrators of concurrent multifrequency sounds. Moreover, the ensemble neural activity in A2 was sensitive to two-tone timings, and coincident two-tones evoked distinct ensemble activity patterns from the linear sum of component tones. Together, these results demonstrate distinct roles of A1 and A2 in encoding complex acoustic features, potentially suggesting parallel rather than sequential information extraction between these regions.
Defect functionalization of single-walled carbon nanotubes (SWCNTs) by chemical modification is a promising strategy for near-infrared photoluminescence (NIR PL) generation at >1000 nm, which has ...advanced telecom and bio/medical applications. The covalent attachment of molecular reagents generates sp3-carbon defects in the sp2-carbon lattice of SWCNTs with bright red-shifted PL generation. Although the positional difference between proximal sp3-carbon defects, labeled as the defect binding configuration, can dominate NIR PL properties, the defect arrangement chemistry remains unexplored. Here, aryldiazonium reagents with π-conjugated ortho-substituents (phenyl and acetylene groups) were developed to introduce molecular interactions with nanotube sidewalls into the defect-formation chemical reaction. The functionalized chiral SWCNTs selectively emitted single defect PL in the wavelength range of ∼1230–1270 nm for (6,5) tubes, indicating the formation of an atypical binding configuration, different from those exhibited by typical aryl- or alkyl-functionalized chiral tubes emitting ∼1150 nm PL. Moreover, the acetylene-based substituent design enabled PL brightening and a subsequent molecular modification of the doped sites using click chemistry.
The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of gastric cancer (GC) was published in 2016, and ...covered the management and treatment of local, locoregional, locally advanced and metastatic disease. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and The Japanese Society of Medical Oncology (JSMO) to convene a special guidelines meeting immediately after the JSMO Annual Meeting in 2018. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic GC in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic GC representing the oncological societies of Japan (JSMO), China (CSCO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of both the current treatment practices and the drug availability and reimbursement situations in the individual participating Asian countries.
For decades, improved theory and experiment of the n=2 ^{3}P fine structure of helium have allowed for increasingly precise tests of quantum electrodynamics, determinations of the fine-structure ...constant α, and limitations on possible beyond-the-standard-model physics. Here we use the new frequency-offset separated-oscillatory-fields technique to measure the 2^{3}P_{2}→2^{3}P_{1} interval. Our result of 2 291 176 590(25) Hz represents a major step forward in precision for helium fine-structure measurements.
Summary
Background
Bariatric surgery leads to a higher remission rate for type 2 diabetes mellitus than non‐surgical treatment. However, it remains unsolved which surgical procedure is the most ...efficacious. This network meta‐analysis aimed to rank surgical procedures in terms of diabetes remission.
Methods and findings
We electronically searched for randomized controlled trials in which at least one surgical treatment was included among multiple arms and the diabetes remission rate was included in study outcomes. A random‐effects network meta‐analysis was performed within a frequentist framework. The hierarchy of treatments was expressed as the surface under the cumulative ranking curve value. Results of the analysis of 25 eligible randomized controlled trials that covered non‐surgical treatments and eight surgical procedures (biliopancreatic diversion BPD, BPD with duodenal switch, Roux‐en Y gastric bypass, mini gastric bypass mini‐GBP, laparoscopic adjustable gastric banding, laparoscopic sleeve gastrectomy, greater curvature plication and duodenal‐jejunal bypass) showed that BPD and mini‐GBP had the highest surface under the cumulative ranking curve values among the eight surgical treatments.
Conclusion
Current network meta‐analysis indicated that BPD or mini‐GBP achieved higher diabetes remission rates than the other procedures. However, the result needs to be interpreted with caution considering that these procedures were in the minority of bariatric surgeries.
Instability and transition in the boundary layer on a slender cone ($60^{\circ }$ apex angle) rotating in still fluid are investigated using hot-wire anemometry as well as through linear stability ...analysis. In contrast to broad cones (including the disk), where a cross-flow instability dominates the transition and different studies report similar transition Reynolds numbers, the reported transition Reynolds numbers on slender cones are scattered. The present experiments provide quantitative experimental datasets and the stability and transition are evaluated based on both the Reynolds number and a Görtler number. The results consistently show that the instability development depends on the Görtler number rather than the Reynolds number and that transition starts at a well-defined Görtler number, whereas the transition Reynolds number depends on the rotational rate. The measured disturbance that first grows in the laminar region has a frequency approximately the same as or twice the rotational rate of the cone, which according to the stability analysis corresponds to the critical frequency of a slightly inclined vortex structure with respect to the cone axis or an axisymmetric vortex structure. These structures are similar to those observed in the flow visualisations of Kobayashi & Izumi (J. Fluid Mech., vol. 127, 1983, pp. 353–364) and considered as being due to a centrifugal instability.
Abstract
Integration of multi-frequency sounds into a unified perceptual object is critical for recognizing syllables in speech. This “feature binding” relies on the precise synchrony of each ...component’s onset timing, but little is known regarding its neural correlates. We find that multi-frequency sounds prevalent in vocalizations, specifically harmonics, preferentially activate the mouse secondary auditory cortex (A2), whose response deteriorates with shifts in component onset timings. The temporal window for harmonics integration in A2 was broadened by inactivation of somatostatin-expressing interneurons (SOM cells), but not parvalbumin-expressing interneurons (PV cells). Importantly, A2 has functionally connected subnetworks of neurons preferentially encoding harmonic over inharmonic sounds. These subnetworks are stable across days and exist prior to experimental harmonics exposure, suggesting their formation during development. Furthermore, A2 inactivation impairs performance in a discrimination task for coincident harmonics. Together, we propose A2 as a locus for multi-frequency integration, which may form the circuit basis for vocal processing.
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