GABA-modulating bacteria of the human gut microbiota.

The gut microbiota affects many important host functions, including the immune response and the nervous system1. However, while substantial progress has been made in growing diverse microorganisms of the microbiota2, 23-65% of species residing in the human gut remain uncultured3,4, which is an obstacle for understanding their biological roles. A likely reason for this unculturability is the absence in artificial media of key growth factors that are provided by neighbouring bacteria in situ5,6. In the present study, we used co-culture to isolate KLE1738, which required the presence of Bacteroides fragilis to grow. Bioassay-driven purification of B. fragilis supernatant led to the isolation of the growth factor, which, surprisingly, is the major inhibitory neurotransmitter GABA (γ-aminobutyric acid). GABA was the only tested nutrient that supported the growth of KLE1738, and a genome analysis supported a GABA-dependent metabolism mechanism. Using growth of KLE1738 as an indicator, we isolated a variety of GABA-producing bacteria, and found that Bacteroides ssp. produced large quantities of GABA. Genome-based metabolic modelling of the human gut microbiota revealed multiple genera with the predicted capability to produce or consume GABA. A transcriptome analysis of human stool samples from healthy individuals showed that GABA-producing pathways are actively expressed by Bacteroides, Parabacteroides and Escherichia species. By coupling 16S ribosmal RNA sequencing with functional magentic resonance imaging in patients with major depressive disorder, a disease associated with an altered GABA-mediated response, we found that the relative abundance levels of faecal Bacteroides are negatively correlated with brain signatures associated with depression

Model of Bayesian tangent eye shape for eye capture

Iris recognition system captures an image of an individual's eye. In addition, the process of segmentation, normalization and feature extraction is followed by the iris of an eye image in the system. Using the algorithms proposed by J. Daugman, Iris recognition system has significantly improved over the last decade, and it has been used in so many practical applications. However, some difficulties related to Iris position and movement are still to be improved. To overcome these difficulties one can enhance the image acquisition process. Obtaining a method in extracting quality of eye images automatically from the video stream is the main area of interest in this study. Besides, a Bayesian inference solution called Bayesian Tangent Eye Shape Model (BTESM) was suggested depending on estimation of tangent shape. During image acquisition, constraints on the position and motion of the subjects can be decreased owing to this approach. Owing to maximum a posteriori estimation, we can identify similarity transform coefficients as well as the eye shape parameters in BTESM. To apply the maximum a posteriori procedure, tangent Eye shape vector was considered the state of the model which is hidden and expectation maximization depending on searching algorithm was adopted. Hence, after being tested and matched to future studies, the acquisitioned eye image has been proved to be adequate for Iris recognition system

Foliar Morphology And Anatomy Of The Gigantopterid Plant Delnortea Abbottiae, From The Lower Permian Of West Texas

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142005/1/ajb214202.pd

Функціоналізовані вуглецеві нанотрубки на поруватому кремнії для сенсорних застосувань

Еволюція газових датчиків на основі вуглецевих нанотрубок (CNTs) викликала великий інтерес серед дослідників в останнє десятиріччя через їх вибірковість для різних газоподібних середовищ, швидку реакцію, високу чутливість та роботу за кімнатної температури. Функціоналізовані одностінні вуглецеві нанотрубки (F-SWCNTs) та функціоналізовані багатостінні вуглецеві нанотрубки (FMWCNTs) були використані для виготовлення датчика газу на основі діоксиду азоту. Плівки з CNTs наносилися на порувату підкладку кремнію (n-типу) методом краплинного лиття. Шар поруватого кремнію (PS) був виготовлений за допомогою фотоелектрохімічного травлення. Щільність прикладеного струму становить 20 мА/см2 із зеленим лазерним випромінюванням, а типовий час фотоелектрохімічного травлення становив близько 15 хв. Коли зразки F-SWCNTs та F-MWCNTs піддавалися впливу газу NO2 при різних робочих температурах, результати відгуку чутливості показують, що FSWCNTs мають кращі показники, ніж F-MWCNTs. При 200 °C, чутливість F-SWCNTs/PS досягає 61 %, час відгуку та час відновлення становили відповідно 10 с і 214 с, тоді як для F-MWCNTs/PS чутливість сягає 57 % при 100 °С, час відгуку та час відновлення складали приблизно 20 с і 647 с відповідно. У той же час, F-MWCNTs мають робочу температуру (100 °C) меншу за температури F-SWCNTs (200 °C).The evolution of carbon nanotube (CNTs) based gas sensors has attracted great interest among researchers in the last decade because of their selectivity for various gaseous media, fast response, high sensitivity and room temperature operation. Functionalized single-walled carbon nanotubes (F-SWCNTs) and functionalized multi-walled carbon nanotubes (F-MWCNTs) have been utilized to manufacture nitrogen dioxide gas sensor. CNTs films have been deposited on (n-type) porous silicon substrate by the drop casting technique. A porous silicon layer (PS) was prepared using the photo-electrochemical etching. The applied current density is 20 mA/cm2 with green laser radiation, and the typical photo-electrochemical etching time was about 15 min. When the F-SWCNTs and F-MWCNTs samples were exposed to NO2 gas at different operating temperatures, the sensitivity response results show that the F-SWCNTs have better performance than the F-MWCNTs. At 200 °C the F-SWCNTs/PS sensitivity reaches 61%, the response time and the recovery time were about 10 s and 214 s, respectively; whereas for the F-MWCNTs/PS the sensitivity reaches 57 % at 100 °C, the response time and the recovery time were about 20 s and 647 s, respectively. At the same time, the F-MWCNTs have an operating temperature (100 °C) less than that of the F-SWCNTs (200 °C)

Real-Time Vision-Based Stiffness Mapping

This paper presents new findings concerning a hand-held stiffness probe for the medical diagnosis of abnormalities during palpation of soft-tissue. Palpation is recognized by the medical community as an essential and low-cost method to detect and diagnose disease in soft-tissue. However, differences are often subtle and clinicians need to train for many years before they can conduct a reliable diagnosis. The probe presented here fills this gap providing a means to easily obtain stiffness values of soft tissue during a palpation procedure. Our stiffness sensor is equipped with a multi degree of freedom (DoF) Aurora magnetic tracker, allowing us to track and record the 3D position of the probe whilst examining a tissue area, and generate a 3D stiffness map in real-time. The stiffness probe was integrated in a robotic arm and tested in an artificial environment representing a good model of soft tissue organs; the results show that the sensor can accurately measure and map the stiffness of a silicon phantom embedded with areas of varying stiffness

Radial force characteristics of multi-consequent-pole bearingless motor

Multi-consequent-pole bearingless motors can be used in low speed rotating and swinging stages (or platforms) under specific conditions. A test machine has been designed and built and in this machine two axes of freedom are actively controlled in the radial x-y directions. The suspension windings are of a novel toroidal shape, i.e., they are wound around the stator yoke. This produces a low axial length because the coil ends are compact. In the paper, a multi-consequent-pole rotor design is presented. The design procedure considered the leakage fluxes and magnetic saturation and used a three dimensional finite element analysis before the machine was constructed and tested. This paper proposes a novel structure for the suspension windings and the rotor. The suspension of the rotor was found to be successfully achieved and these characteristics are put forward in the paper

6-Nitro-2-(3-hydroxypropyl)-1H-benz[de]isoquinoline-1,3-dione, a potent antitumor agent, induces cell cycle arrest and apoptosis

<p>Abstract</p> <p>Background</p> <p>Anticancer activities of several substituted naphthalimides (1H-benz[de]isoquinoline-1,3-diones) are well documented. Some of them have undergone Phase I-II clinical trials. Presently a series of ten N-(hydroxyalkyl) naphthalimides (compounds <b>1a-j) </b>were evaluated as antitumor agents.</p> <p>Methods</p> <p>Compounds <b>1a-j </b>were initially screened in MOLT-4, HL-60 and U-937 human tumor cell lines and results were compared with established clinical drugs. Cytotoxicities of compounds <b>1d </b>and <b>1i </b>were further evaluated in a battery of human tumor cell lines and in normal human peripheral blood mononuclear cells. Cell cycle analysis of compound <b>1i </b>treated MOLT-4 cells was studied by flow cytometry. Its apoptosis inducing effect was carried out in MOLT-4 and HL-60 cells by flow cytometry using annexin V-FITC/PI double staining method. The activities of caspase-3 and caspase-6 in MOLT-4 cells following incubation with compound <b>1i </b>were measured at different time intervals. Morphology of the MOLT-4 cells after treatment with <b>1i </b>was examined under light microscope and transmission electron microscope. ³H-Thymidine and ³H-uridine incorporation in S-180 cells in vitro following treatment with 8 μM concentration of compounds <b>1d </b>and <b>1i </b>were studied.</p> <p>Results</p> <p>6-Nitro-2-(3-hydroxypropyl)-1H-benz[de]isoquinoline-1,3-dione (compound <b>1i</b>), has exhibited maximum activity as it induced significant cytotoxicity in 8 out of 13 cell lines employed. Interestingly it did not show any cytotoxicity against human PBMC (IC₅₀value 273 μM). Cell cycle analysis of compound <b>1i </b>treated MOLT-4 cells demonstrated rise in sub-G₁fraction and concomitant accumulation of cells in S and G₂/M phases, indicating up-regulation of apoptosis along with mitotic arrest and/or delay in exit of daughter cells from mitotic cycle respectively. Its apoptosis inducing effect was confirmed in flow cytometric study in MOLT-4 and the action was mediated by activation of both caspase 3 and 6. Light and transmission electron microscopic studies corroborated its apoptosis inducing efficacy at a concentration of 10 μM in MOLT-4 cells. Its apoptosis induction was also observed in HL-60 cells to an extent much greater than well known apoptosis inducing agents as camptothecin and cis-platin at 10 μM concentration each. It significantly inhibited DNA and RNA synthesis in S-180.</p> <p>Conclusions</p> <p>In essence, compound <b>1i </b>showed potential as an antitumor agent.</p

Maximal interferon induction by influenza lacking NS1 is infrequent owing to requirements for replication and export.

Influenza A virus exhibits high rates of replicative failure due to a variety of genetic defects. Most influenza virions cannot, when acting as individual particles, complete the entire viral life cycle. Nevertheless influenza is incredibly successful in the suppression of innate immune detection and the production of interferons, remaining undetected in >99% of cells in tissue-culture models of infection. Notably, the same variation that leads to replication failure can, by chance, inactivate the major innate immune antagonist in influenza A virus, NS1. What explains the observed rarity of interferon production in spite of the frequent loss of this, critical, antagonist? By studying how genetic and phenotypic variation in a viral population lacking NS1 correlates with interferon production, we have built a model of the "worst-case" failure from an improved understanding of the steps at which NS1 acts in the viral life cycle to prevent the triggering of an innate immune response. In doing so, we find that NS1 prevents the detection of de novo innate immune ligands, defective viral genomes, and viral export from the nucleus, although only generation of de novo ligands appears absolutely required for enhanced detection of virus in the absence of NS1. Due to this, the highest frequency of interferon production we observe (97% of infected cells) requires a high level of replication in the presence of defective viral genomes with NS1 bearing an inactivating mutation that does not impact its partner encoded on the same segment, NEP. This is incredibly unlikely to occur given the standard variation found within a viral population, and would generally require direct, artificial, intervention to achieve at an appreciable rate. Thus from our study, we procure at least a partial explanation for the seeming contradiction between high rates of replicative failure and the rarity of the interferon response to influenza infection