Corpuscles of Stannius of freshwater catfish, Clarias Batrachus

O presente artigo estuda o número, localização e estrutura citológica dos corpúsculos de Stannius do bagre de água doce Clarias batrachus. Ocorre apenas um tipo celular e as células são eosina +, AF + e PAS +

Design and Validation for FPGA Trust under Hardware Trojan Attacks

Field programmable gate arrays (FPGAs) are being increasingly used in a wide range of critical applications, including industrial, automotive, medical, and military systems. Since FPGA vendors are typically fabless, it is more economical to outsource device production to off-shore facilities. This introduces many opportunities for the insertion of malicious alterations of FPGA devices in the foundry, referred to as hardware Trojan attacks, that can cause logical and physical malfunctions during field operation. The vulnerability of these devices to hardware attacks raises serious security concerns regarding hardware and design assurance. In this paper, we present a taxonomy of FPGA-specific hardware Trojan attacks based on activation and payload characteristics along with Trojan models that can be inserted by an attacker. We also present an efficient Trojan detection method for FPGA based on a combined approach of logic-testing and side-channel analysis. Finally, we propose a novel design approach, referred to as Adapted Triple Modular Redundancy (ATMR), to reliably protect against Trojan circuits of varying forms in FPGA devices. We compare ATMR with the conventional TMR approach. The results demonstrate the advantages of ATMR over TMR with respect to power overhead, while maintaining the same or higher level of security and performances as TMR. Further improvement in overhead associated with ATMR is achieved by exploiting reconfiguration and time-sharing of resources

Kinetics of the Oxidation of Hydrogen Sulfide by Atmospheric Oxygen in an Aqueous Medium

Hydrogen sulfide is an important acid rain precursor and this led us to investigate the kinetics of its oxidation in aqueous phase by atmospheric oxygen. The kinetics was followed by measuring the depletion of oxygen in a reactor. The reaction was studied under pseudo order conditions with [H2S] in excess. The kinetics followed the rate law: -d[O2]/dt = k[S][O2]t (A) Where [S] represents the total concentration of hydrogen sulfide, [O2]t is the concentration of oxygen at time t and k is the second order rate constant. The equilibria (B - C) govern the dissolution of H2S; the sulfide ion in water forms different species: H2S K1 HS- + H+ (B) HS- K2 S2- + H+ (C) Where K1 and K2 are first and second dissociation constants of H2S. Although, H2S is present as undissociated H2S, HS- and S2- ions, nature of [H+ ] dependence of reaction rate required only HS- to be reactive and dominant. The rate law (A) on including [H+ ] dependence became Equation (D). -d[O2]/dt = k1K1[H+ ][S][O2]t / ([H+ ] 2 + K1[H+ ] + K1K2) (D) Our results indicate anthropogenic VOCs such as acetanilide, benzene, ethanol, aniline, toluene, benzamide, o-xylene, m-xylene, p-xylene and anisole to have no significant effect on the reaction rate and any observed small effect is within the uncertainty of the rate measurements

Detection of off-pulse emission from PSR B0525+21 and PSR B2045-16

We report the detection of off-pulse emission from two long period pulsars PSR B0525+21 and PSR B2045-16 using the Giant Metrewave Radio Telescope (GMRT). We recorded high time resolution interferometric data at 325 MHz and gated the data offline to separate the on- and off-pulse sections of the pulsar. On imaging the two temporal sections separately, we detected a point source in the off-pulse images of both the pulsars coincident with the pulsar locations in the on-pulse images. The long periods (3.75 and 1.96 s respectively) and low spin-down energies (E ~ 10exp(31) erg s-1) of the two pulsars argue against a pulsar wind nebula (PWN) origin for the off-pulse emission. The derived estimates of the ISM particle density required to drive a PWN do not support such an interpretation. A magnetospheric origin for the off-pulse emission raises questions regarding the location of the emission region, which is an important input into pulsar emission models.Comment: 15 pages, 11 figure

A CNN and LSTM-based Model for Creating Captions for Photos

Can a machine interpret an image's meaning with the same speed as the human brain when it is seen? This problem was heavily researched by computer vision specialists, who believed it to be unsolvable until recently. It is now possible to develop models that can generate captions for pictures because of advancements in deep learning techniques, accessibility to large datasets, and processing power. This will be accomplished by the Python-based implementation of the article's deep learning convolutional neural network technique and a particular kind of recurrent neural network. Here the proposed model uses CNN and LSTM methods to achieve desired tas

Occultations of 50 radio sources at 327 MHz

Radio positions and brightness distributions derived from lunar occultations observed with the Ooty radio telescope at 327 MHz are reported for 50 radio sources, most of them in the flux density range of 0.3-2×10-26Wm-2/Hz-1. A lange majority of the so urces is resolved, with angular sizes of about 2-20 arcsec. Only 13 sources are identified with optical objects; nine with galaxies, three with blue-stellar objects and one with a stellar object

Formation of a gold-carbon dot nanocomposite with superior catalytic ability for the reduction of aromatic nitro groups in water

We report the synthesis of a gold-carbon dot nanocomposite and its utility as a recyclable catalyst for the reduction of aromatic nitro groups. The presence of carbon dots on gold nanosurfaces enhanced the reduction rate by two-fold

A diffuse bubble-like radio-halo source MRC 0116+111: imprint of AGN feedback in a low-mass cluster of galaxies

We present detailed observations of MRC 0116+111, revealing a luminous, mini radio-halo of ~240 kpc diameter located at the centre of a cluster of galaxies at redshift z = 0.131. Our optical and multi-wavelength GMRT and VLA radio observations reveal a highly unusual radio source: showing a pair of giant (~100 kpc diameter) bubble-like diffuse structures, that are about three times larger than the analogous extended radio emission observed in M87 - the dominant central radio galaxy in the Virgo Cluster. However, in MRC 0116+111 we do not detect any ongoing Active Galactic Nucleus (AGN) activity, such as a compact core or active radio jets feeding the plasma bubbles. The radio emitting relativistic particles and magnetic fields were probably seeded in the past by a pair of radio-jets originating in the AGN of the central cD galaxy. The extremely steep high-frequency radio spectrum of the north-western bubble, located ~100 kpc from cluster centre, indicates radiation losses, possibly because having detached, it is rising buoyantly and moving away into the putative hot intra-cluster medium. The other bubble, closer to the cluster centre, shows signs of ongoing particle re-acceleration. We estimate that the radio jets which inflated these two bubbles might have also fed enough energy into the intra-cluster medium to create an enormous system of cavities and shock fronts, and to drive a massive outflow from the AGN, which could counter-balance and even quench a cooling flow. Therefore, this source presents an excellent opportunity to understand the energetics and the dynamical evolution of radio-jet inflated plasma bubbles in the hot cluster atmosphere.Comment: 15 pages, 8 figures. Accepted for publication in MNRA

Deep GMRT 150 MHz observations of the LBDS-Lynx region: Ultra-Steep Spectrum Radio Sources

It has been known for nearly three decades that high redshift radio galaxies exhibit steep radio spectra, and hence ultra-steep spectrum radio sources provide candidates for high-redshift radio galaxies. Nearly all radio galaxies with z > 3 have been found using this redshift-spectral index correlation. We have started a programme with GMRT to exploit this correlation at flux density levels about 10 to 100 times deeper than the known high-redshift radio galaxies which were identified primarily using the already available radio catalogues. In our programme, we have obtained deep, high resolution radio observations at 150 MHz with GMRT for several 'deep' fields which are well studied at higher radio frequencies and in other bands of the electromagnetic spectrum, with an aim to detect candidate high redshift radio galaxies. In this paper we present results from the deep 150 MHz observations of LBDS-Lynx field, which has been already imaged at 327, 610 and 1412 MHz with the WSRT and at 1400 and 4860 MHz with the VLA. The 150 MHz image made with GMRT has a rms noise of ~0.7 mJy/beam and a resolution of ~19" X 15". It is the deepest low frequency image of the LBDS-Lynx field. The source catalog of this field at 150 MHz has about 765 sources down to ~20% of the primary beam response, covering an area of about 15 degree$^2$. Spectral index was estimated by cross correlating each source detected at 150 MHz with the available observations at 327, 610, 1400 and 4860 MHz and also using available radio surveys such as WENSS at 327 MHz and NVSS and FIRST at 1400 MHz. We find about 150 radio sources with spectra steeper than 1. About two-third of these are not detected in SDSS, hence are strong candidate high-redshift radio galaxies, which need to be further explored with deep infra-red imaging and spectroscopy to estimate the redshift.Comment: Accepted for publication in MNRAS, 24 pages (including 12 pages online material), 9 Figures, 5 Table