A parameterisable FPGA-tailored architecture for YOLOv3-Tiny

Object detection is the task of detecting the position of objects in an image or video as well as their corresponding class. The current state of the art approach that achieves the highest performance (i.e. fps) without significant penalty in accuracy of detection is the YOLO framework, and more specifically its latest version YOLOv3. When embedded systems are targeted for deployment, YOLOv3-tiny, a lightweight version of YOLOv3, is usually adopted. The presented work is the first to implement a parameterised FPGA-tailored architecture specifically for YOLOv3-tiny. The architecture is optimised for latency-sensitive applications, and is able to be deployed in low-end devices with stringent resource constraints. Experiments demonstrate that when a low-end FPGA device is targeted, the proposed architecture achieves a 290x improvement in latency, compared to the hard core processor of the device, achieving at the same time a reduction in mAP of 2.5 pp (30.9% vs 33.4%) compared to the original model. The presented work opens the way for low-latency object detection on low-end FPGA devices

Can adsorption be studied in the electrode potential range of severe hydrogen evolution

Surface enhanced Raman spectroscopy(SERS) has been applied to obtain structural information of surface species adsorbed at electrode surface in the electrode potential range of severe hydrogen evolution, which is very difficult to be gained by using most of spectroelectrochemical and conventional electrochemical methods

Initial potential effect on the dissociative adsorption of methanol on a roughened platinum electrode in acidic solution

In situ Raman spectroscopic and voltammetric studies indicate that dissociative adsorption of methanol on the rough platinum electrode occurs in the hydrogen ad/desorption potential range, and the dissociative extent depends on the initial potential of the electrode before contacting methanol, in addition to the contacting time. As the dissociative product, carbon monoxide competes the site of strongly bound hydrogen preferentially, and shifts the ad/desorption potentials of weakly bound hydrogen towards more positive ones gradually with the increase of CO coverage. Whereas, formaldehyde dissociates more easily by far and completely suppresses H-adsorption. The confocal Raman spectroscopy developed on transition metals shows some intriguing advantages in investigating electrocatalytic oxidation of small organic molecules

Probing electrode/electrolyte interfacial structure in the potential region of hydrogen evolution by Raman spectroscopy

The detailed interfacial structure in the potential region of severe hydrogen evolution, to date, is far from clear due to lack of both experimental data and correlated theoretic models. It has been shown that it is possible to surmount, to some extent, the disturbance of the spectroelectrochemical measurement by strong hydrogen bubbling in the potential region of severe hydrogen evolution by using a surface enhancement effect and a thin-layer cell configuration. Using this approach, we have obtained surface enhanced Raman scattering (SERS) spectra of water at an Ag electrode at very negative potentials at various concentrations of NaClO4. To explain the abnormal reversal of the peak intensity ratio of the bending to the stretching vibration, a preliminary model of the electrode/electrolyte interface is presented. The water molecule is oriented with one hydrogen attached to the surface and the oxygen towards an adsorbed cation which is partially dehydrated owing to the very strong electrostatic force. Raman spectra of hydrogen bound at a Pt electrode in solutions of varying pH from 0 to 14 at potentials of mild hydrogen evolution have also been presented for the first time. The spectra reveal that the Pt-hydrogen interaction is influenced by both the potential and the interfacial structure. These primary studies may initiate more molecular-level research of electrochemical interfaces in the potential region of hydrogen evolution

Surface Raman spectroscopic investigation of pyridine adsorption at platinum electrodes - effects of potential and electrolyte

Surface enhanced Raman spectra of pyridine (Py) at Pt electrodes have been investigated as a function of potential and supporting electrolyte. The results show a large difference from those reported for coinage metal electrodes of Ag, Au and Cu, emphasising the effective involvement of chemical enhancement on Pt surfaces. At very negative (or positive) potentials, Raman spectra show the competitive coadsorption of hydrogen (or oxygen-containing species) with Py, and in acidic solutions, PyH+ ions prefer to dissociate into Py adsorbed on Pt surfaces even in the presence of chloride ions. The differences in the surface bonding strength for Py on Pt and coinage metal electrodes are explained in terms of the different electronic configurations of the metals

The lncRNA HOTAIR transcription is controlled by HNF4α-induced chromatin topology modulation

The expression of the long noncoding RNA HOTAIR (HOX Transcript Antisense Intergenic RNA) is largely deregulated in epithelial cancers and positively correlates with poor prognosis and progression of hepatocellular carcinoma and gastrointestinal cancers. Furthermore, functional studies revealed a pivotal role for HOTAIR in the epithelial-to-mesenchymal transition, as this RNA is causal for the repressive activity of the master factor SNAIL on epithelial genes. Despite the proven oncogenic role of HOTAIR, its transcriptional regulation is still poorly understood. Here hepatocyte nuclear factor 4-α (HNF4α), as inducer of epithelial differentiation, was demonstrated to directly repress HOTAIR transcription in the mesenchymal-to epithelial transition. Mechanistically, HNF4α was found to cause the release of a chromatin loop on HOTAIR regulatory elements thus exerting an enhancer-blocking activity

Inhibition of the tyrosine phosphatase SHP-2 suppresses angiogenesis in vitro and in vivo

Endothelial cell survival is indispensable to maintain endothelial integrity and initiate new vessel formation. We investigated the role of SHP-2 in endothelial cell survival and angiogenesis in vitro as well as in vivo. SHP-2 function in cultured human umbilical vein and human dermal microvascular endothelial cells was inhibited by either silencing the protein expression with antisense-oligodesoxynucleotides or treatment with a pharmacological inhibitor (PtpI IV). SHP-2 inhibition impaired capillary-like structure formation (p < 0.01; n = 8) in vitro as well as new vessel growth ex vivo (p < 0.05; n = 10) and in vivo in the chicken chorioallantoic membrane (p < 0.01, n = 4). Additionally, SHP-2 knock-down abrogated fibroblast growth factor 2 (FGF-2)-dependent endothelial proliferation measured by MTT reduction ( p ! 0.01; n = 12). The inhibitory effect of SHP-2 knock-down on vessel growth was mediated by increased endothelial apoptosis ( annexin V staining, p ! 0.05, n = 9), which was associated with reduced FGF-2-induced phosphorylation of phosphatidylinositol 3-kinase (PI3-K), Akt and extracellular regulated kinase 1/2 (ERK1/2) and involved diminished ERK1/2 phosphorylation after PI3-K inhibition (n=3). These results suggest that SHP-2 regulates endothelial cell survival through PI3-K-Akt and mitogen-activated protein kinase pathways thereby strongly affecting new vessel formation. Thus, SHP-2 exhibits a pivotal role in angiogenesis and may represent an interesting target for therapeutic approaches controlling vessel growth. Copyright (C) 2007 S. Karger AG, Basel

Surface enhanced Raman scattering from bare cobalt electrode surfaces

Surface enhanced Raman spectra (SERS) of adsorbed species from a bare cobalt (Co) bulk electrode were observed for the first time with confocal Raman microscopy. A combined AFM, Raman and electrochemical study shows that a proper roughening procedure is vitally important for obtaining good-quality surface Raman spectra from the Co electrode. The surface enhancement factor ranges from 2 to 3 orders of magnitude, depending critically on the surface roughening procedure. The present study provides a bright prospect for the wide investigation of systems of practical application

Electronic properties of metal nanorods probed by surface-enhanced Raman spectroscopy

Applying the probe molecule strategy, surface-enhanced Raman spectroscopy has been used, for the first time, as a diagnostic tool of the electronic properties of metal nanorods; the vibrational frequency of the probe molecule SCN- at Cu nanorods is shown to critically depend on the nanorod's diameter in the range from 50 to 15 nm; the up-shifting of the Fermi level with a decrease of the nanorod's diameter is interpreted based on the change of cohesive energy owing to the high ratio of surface to bulk atoms

In-situ SERS study on the electro-oxidation with HCOOH on a roughened platinum electrode

The dissociative adsorption and oxidation behavior of HCOOH on Pt was investigated by cyclic voltammogram (CV) and in-situ surface enhanced Raman spectroscopy (SERS) techniques. The in-stiu SERS of HCOOH adsorption, dissociation and oxidation on rough Pt is reported. It is found that HCOOH can spontaneously dissociate. The surface Raman spectra of CO, the strongly adsorbed intermediate and COOH, the weakly adsorbed intermediate of the dissociative adsorption of HCOOH were successfully obtained for the first time. At the same time, the Raman spectra of the finally oxidized product CO2 of HCOOH was also firstly detected. The dual path reaction mechanism for the oxidation of HCOOH was confirmed at molecular level