Clusters of synaptic inputs on dendrites of layer 5 pyramidal cells in mouse visual cortex

The spatial organization of synaptic inputs on the dendritic tree of cortical neurons plays a major role for dendritic integration and neural computations, yet, remarkably little is known about it. We mapped the spatial organization of glutamatergic synapses between layer 5 pyramidal cells by combining optogenetics and 2-photon calcium imaging in mouse neocortical slices. To mathematically characterize the organization of inputs we developed an approach based on combinatorial analysis of the likelihoods of specific synapse arrangements. We found that the synapses of intralaminar inputs form clusters on the basal dendrites of layer 5 pyramidal cells. These clusters contain 4 to 14 synapses within <= 30 mu m of dendrite. According to the spatiotemporal characteristics of synaptic summation, these numbers suggest that there will be non-linear dendritic integration of synaptic inputs during synchronous activation

Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana)

Infectious diseases remain a significant threat to human health, contributing to more than 17 million deaths, annually. With the worsening trends of drug resistance, there is a need for newer and more powerful antimicrobial agents. We hypothesized that animals living in polluted environments are potential source of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of microbes, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances. Here, we characterized antibacterial properties in extracts of various body organs of cockroaches (Periplaneta americana) and showed potent antibacterial activity in crude brain extract against methicillin-resistant Staphylococcus aureus and neuropathogenic E. coli K1. The size-exclusion spin columns revealed that the active compound(s) are less than 10 kDa in molecular mass. Using cytotoxicity assays, it was observed that pre-treatment of bacteria with lysates inhibited bacteria-mediated host cell cytotoxicity. Using spectra obtained with LC-MS on Agilent 1290 infinity liquid chromatograph, coupled with an Agilent 6460 triple quadruple mass spectrometer, tissues lysates were analyzed. Among hundreds of compounds, only a few homologous compounds were identified that contained isoquinoline group, chromene derivatives, thiazine groups, imidazoles, pyrrole containing analogs, sulfonamides, furanones, flavanones, and known to possess broad-spectrum antimicrobial properties, and possess anti-inflammatory, anti-tumour, and analgesic properties. Further identification, characterization and functional studies using individual compounds can act as a breakthrough in developing novel therapeutics against various pathogens including superbugs

Energy cost of walking with flat feet

Abstract A comparative study has been conducted to assess the effects of arch support on oxygen consumption in 20 subjects with flat feet who were generally complaining about fatigue, and also to explore whether their feeling of weariness was objective or not. The resting, walking and final recovery heart rates, blood pressures, and walking oxygen consumption values of the patients with flat feet were measured and calculated and compared to a control group using treadmill and oxygen consumption devices. In stage one the patients did not wear any arch support. Then suitable arch supports were prepared for each patient and in stage two they wore these arch supports. The results did not show any significant difference between the resting heart rates, blood pressure and oxygen consumptions. However, differences in walking heart rate, systolic blood pressure, final recovery heart rate, oxygen consumption, and energy cost values were found to be significant between stage one and two of the test in the patient group. The difference in walking diastolic blood pressure values without and with arch support were found to be insignificant. It may therefore be deduced that oxygen consumption during walking is decreased when a suitable arch support is applied to patients with flat feet

A nondestructive testing technique: Nail penetration test

This study presents a practical nondestructive testing (NDT) method: the nail penetration test (NPT). The major tools of the test technique are a gas nailer with 130 J (95.88 ft-lbf) power, concrete nails, and a gas nailer cell. The study covers three different limestone aggregate types. Six concrete mixtures were prepared from each aggregate type. Five nail shots were performed on each concrete mixture (or grade) and the average value was obtained. The average nail penetration depths were correlated with the compressive strength of concrete. Other NDT techniques, such as the Schmidt rebound hammer (SRH), ultrasonic pulse velocity (UPV), and Windsor probe (WP), were also applied to concrete samples. The measured compressive strength values were compared with those obtained from the empirical relationships using the data from the NPT, SRH, UPV, and WP. It was found that the reliability of the NPT to estimate the compressive strength of concrete is very high. The tool employed in the investigation covers a relatively wide range of compressive strength of concrete. This testing tool is proposed to estimate the compressive strength of in-place concrete. © 2012, American Concrete Institute

A Novel Characterization Method for MEMS Based Electrostatic Resonators for Q Enhancement and Feedthrough Current Elimination

This paper introduces a new technique for electrostatic resonance characterization based on 2nd harmonic distortion terms at the output current. Mathematical analysis of the output current shows that the 2nd harmonic component exhibits higher quality factor (Q) than the 1st harmonic. Besides, output current to feedthrough current ratio is higher in the 2nd harmonic term. Experimental results show that the Q of the resonating system is enhanced by 66% with 2nd harmonic operation. Moreover, the resonance peak has been improved from 0.2 dB to 5dB, showing the effective increase in output current to the feedthrough ratio

Design of a Resonator-on-Microchannel (RoM) for Gravimetric Detection Applications in Liquid Environment

This paper presents a novel biosensor structure consisting of a resonator placed at the top wall of a microchannel (Resonator-on-Microchannel: RoM). The proposed biosensor structure is aimed to be used for real-time gravimetric detection of microscale biological targets in liquid environment by tracking the resonance frequency change of the system as the sought particles/cells are attached to the resonator surface. The damping effects are minimized with the help of the proposed resonator placement as well as the hydrophobic coating applied around the resonator gaps. Measurement results show that the quality factor drops only by a factor of 0.5 in liquid environment, validating the operation of the structure. (C) 2016 The Authors. Published by Elsevier Ltd