Catfish aquaculture

This article deals with the biology, broodstock management, seed production techniques and grow-out culture practices in C. macrocephalus

Review of Statoconia Formation in Birds and Original Research in Chicks (Gallus domesticus)

This paper reviews published materials on statoconia formation in birds, and emphasizes works dealing with the embryonic chick (Gallus domesticus) saccule and utricule. Histological, biochemical and histochemical aspects of forming statoconial membranes and statoconial crystals of mammals are included. Results from our work with chick embryos permitted us to conclude that statoconia probably do not form by seeding of a subunit around central core. Instead, immature statoconia may emerge already formed, from a segmenting mass of organic material that seems to be secreted by the supporting cells of the saccular and utricular maculae. Crystallization of each statoconium may involve seeding of multiple subunits around many nucleation centers in the organic matrix. Following these processes, calcium (sometimes granular) attaches to immature statoconia and become subsequently incorporated between the fibrils of the organic matrix starting at the peripheral zone and advancing toward the central core. Our transmission electron microscopy findings, histochemistry and X-ray microanalysis complements of other investigators, who used chicks with light microscopic studies. These results agree with the notion that the secretion of an organic matrix constitutes the first step toward the formation of the statoconial membrane and statoconia. We show ultra-structurally how statoconia may be assembled from the organic matrix before they acquire their characteristic geometric shapes

Elliptical-P Cells in the Avian Perilymphatic Interface of the Tegmentum Vasculosum

Elliptical cells (E-P) are present at the perilymphatic interface lumen (PIL) of the lagena. The E-P cells often separate from the tegmentum vasculosum (TV) and have touching processes that form a monolayer between the K+ rich perilymph and the Na+ rich endolymph, similar to the mammalian Reissner\u27s membrane. We examined the TV of chicks (Gallus domesticus) and quantitated the expression of anti-S100ααββ and S100β. There was a 30% increase of S100β saturation in the light cells facing the PIL when compared to other TV light cells. We show that: (1) the dimer anti-S100ααββ and the mono-mer anti-S100β are expressed preferentially in the light cells and the E-P cells of TV; (2) expression of S100β is higher in light cells facing the PIL than in adjacent cells; (3) the expression of the dimer S100ααββ and monomer S100β overlaps in most inner ear cell types, including the cells of the TV, most S100ααββ positive cells express S100β, but S100β positive cells do not always express S100ααββ; and (4) the S100β expression in light cells, the abundant Na+-K+ ATPase on dark cells of the TV, and previously demonstrated co-localization of S100β/GABA in sensory cells suggest that S100β could have, in the inner ear, a dual neurotrophic-ionic modulating function

New insights into the catalytic activity of gold nanoparticles for CO oxidation in electrochemical media

This study reports the interaction between metal oxides and gold in acidic media and its effect on the electrochemical oxidation of carbon monoxide. We describe the oxidation of CO in acidic media on Au nanoparticles of 3 and 7 nm on different oxide supports, diamond and carbon electrodes. In addition, the effect of a TiOx support on Au nanoparticles was mimicked by supporting TiOx nanoparticles on bulk gold. The comparison of these two systems strongly suggests that electronic interactions between Au and TiOx, rather than Au nanoparticle size effects, are the driving force of the catalytic activity in Au–TiOx

Spin dynamics in exchange-biased F/AF bilayers

The spin dynamics of the ferromagnetic pinned layer of ferro-antiferromagnetic coupled NiFe/MnNi bilayers is investigated in a broad frequency range (30 MHz-6 GHz). A phenomenological model based on the Landau-Lifshitz equation for the complex permeability of the F/AF bilayer is proposed. The experimental results are compared to theoretical predictions.Comment: 12 pages, 3 figures, 1 tabl

One-parameter Darboux-transformed quantum actions in Thermodynamics

We use nonrelativistic supersymmetry, mainly Darboux transformations of the general (one-parameter) type, for the quantum oscillator thermodynamic actions. Interesting Darboux generalizations of the fundamental Planck and pure vacuum cases are discussed in some detail with relevant plots. It is shown that the one-parameter Darboux-transformed Thermodynamics refers to superpositions of boson and fermion excitations of positive and negative absolute temperature, respectively. Recent results of Arnaud, Chusseau, and Philippe physics/0105048 regarding a single mode oscillator Carnot cycle are extended in the same Darboux perspective. We also conjecture a Darboux generalization of the fluctuation-dissipation theoremComment: 14 pages, 13 figures, correction of the formula in the text after Eq. 7, accepted at Physica Script

Papaya Ringspot Virus Resistance of Transgenic Rainbow and SunUp is Affected by Gene Dosage, Plant Development, and Coat Protein Homology

R1 plants of the transgenic papaya line 55-1, which expresses a single coat protein (CP) gene of the mild strain of the papaya ringspot virus (PRSV) HA from Hawaii, were previously shown to be resistant only to PRSV isolates from Hawaii. Two transgenic papaya cultivars were subsequently derived from line 55-1. UH SunUp (SunUp) is homozygous for the CP gene insertion and UH Rainbow (Rainbow) is hemizygous for the CP gene because it is a F1 hybrid of a cross between SunUp and the nontransgenic papaya cultivar Kapoho. To determine the various parameters that affect the resistance of SunUp and Rainbow, plants at different developmental stages (younger and older) were inoculated with PRSV isolates from Hawaii, Brazil, Jamaica, and Thailand. Hawaiian isolates shared nucleotide sequence identities of 96.7-99.8% to the CP transgene, and the other isolates shared sequence identities of 89.5-92.5%. Resistance was affected by CP gene dosage, plant developmental stage, and CP sequence identity of the challenge isolate. Young and older hemizygous Rainbow plants were resistant to the homologous PRSV HA (99.8% homology to CP transgene), while only older Rainbow plants were resistant to the other Hawaiian isolates (96.7% homology). However, all inoculated Rainbow plants were susceptible to PRSV isolates collected from Jamaica, Brazil, and Thailand. In contrast, SunUp was resistant to all PRSV isolates, except the one from Thailand, regardless of the plant developmental stage. Resistance to the Thailand isolate, which shares 89.5% homology to the transgene, was observed only with SunUp plants inoculated at an older stage. Steady state RNA analysis and nuclear run-on experiments suggested that resistance of the transgenic papaya is RNA-mediated via post-transcriptional gene silencin

Comparison of DNA Fragmentation and Color Thresholding for Objective Quantitation of Apoptotic Cells

Apoptosis is a process of cell death characterized by distinctive morphological changes and fragmentation of cellular DNA. Using video imaging and color thresholding techniques, we objectively quantitated the number of cultured CD4 + T-lymphoblastoid cells (HUT78 cells, RH9 subclone) displaying morphological signs of apoptosis before and after exposure to γ-irradiation. The numbers of apoptotic cells measured by objective video imaging techniques were compared to numbers of apoptotic cells measured in the same samples by sensitive apoptotic assays that quantitate DNA fragmentation. DNA fragmentation assays gave consistently higher values compared with the video imaging assays that measured morphological changes associated with apoptosis. These results suggest that substantial DNA frag-mentation can precede or occur in the absence of the morphological changes which are associated with apoptosis in γ-irradiated RH9 cells

Serial analysis of gene expression reveals differential expression between endometriosis and normal endometrium. Possible roles for AXL and SHC1 in the pathogenesis of endometriosis

<p>Abstract</p> <p>Background</p> <p>Endometriosis is a clinical condition that affects up to 10% of the women of reproductive age. Endometriosis is characterized by the presence of endometrial tissues outside the uterine cavity and can lead to chronic pelvic pain, infertility and, in some cases, to ovarian cancer.</p> <p>Methods</p> <p>In order to better understand the pathogenesis of endometriosis, we have used Serial Analysis of Gene Expression (SAGE) to identify genes differentially in this disease by studying three endometriotic tissues and a normal endometrium sample. Promising candidates (AXL, SHC1, ACTN4, PI3KCA, p-AKT, p-mTOR, and p-ERK) were independently validated by immunohistochemistry in additional normal and endometriotic tissues.</p> <p>Results</p> <p>We identified several genes differentially expressed between endometriosis and normal endometrium. IGF2, ACTN4, AXL, and SHC1 were among the most upregulated genes. Comparison of the endometriosis gene expression profiles with the gene expression patterns observed in normal human tissues allowed the identification of endometriosis-specific genes, which included several members of the MMP family (MMP1,2,3,10,11,14). Immunohistochemical analysis of several candidates confirmed the SAGE findings, and suggested the involvement of the PI3K-Akt and MAPK signaling pathways in endometriosis.</p> <p>Conclusion</p> <p>In human endometriosis, the PI3K-Akt and MAPK signaling pathways may be activated via overexpression of AXL and SHC1, respectively. These genes, as well as others identified as differentially expressed in this study, may be useful for the development of novel strategies for the detection and/or therapy of endometriosis.</p

Partial Substitution of Cu Sites by Mg for the Improvement of CuWO4 Photoanodes Performance

The photoelectrochemical properties of CuWO4 (Mg x%) thin-films obtained by solution-based methods are investigated as a function of the material composition. The thin-films are prepared by spin-coating a single precursor solution onto FTO-coated glass substrates, followed by an annealing process at 550 °C. XRD, Raman, XPS, and electrochemical data studies indicate the formation of single-phase CuWO4 (Mg x%), with Mg2+ partially substituting Cu2+ sites. Photoelectrochemical studies under monochromatic illumination show an 88.2% increase in photocurrent responses and a 2-fold increase in charge carriers bulk separation efficiency at 1.0 V vs RHE, upon replacing 2.5% of Cu by Mg. DFT calculations reveal that Mg incorporation rearranges electron density, shifting the position of magnesium toward an axial oxygen atom, increasing the covalent nature of the bond and decreasing the Cu–O bond length. It is proposed that a change in the localization of the electron density away from the sphere of influence of the oxygen atom, and toward the shared space of the covalent bond, leads to better carrier mobility and the generation of higher photocurrents