Yeast extract on growth,nutrient utilization and haemato‐immunological responses of Nile tilapia

Dietary supplementation (0, 10, 20, 40, 60, 80 g kg^?1) of a nucleotide source (NuPro^®) was evaluated on growth, nutrient utilization, haemato‐immunological responses and resistance to experimental infection of Nile tilapia. Fish (2.63 ± 0.63 g) were fed experimental diets to satiation three times a day for 75 days. Feed intake increased linearly with increasing levels of NuPro^® promoting higher weight gain (P < 0.05). Survival, feed conversion and protein retention were not affected. Following the growth trial, fish were challenged with Aeromonas hydrophila by intraperitoneal injection. Survival and innate immune responses (phagocytosis and lysozyme activity) were not significantly affected. However, among the haematological variables, thrombocyte, leucocyte and monocyte counts increased linearly (P < 0.05). The indirect measurement of digestibility in juvenile Nile tilapia (122.32 ± 11 g) indicated a linear decrease in protein (1.41%), dry matter (5.72%) and energy (4.10%) digestibility coefficients as dietary supplementation increased (P < 0.05). NuPro^® showed to be a beneficial additive to be supplemented in diets for juvenile Nile tilapia, providing 32.8% increase in feed intake and 28.8% in weight gain, as well as in thrombocyte, leucocyte and monocyte counts in blood, possibly indicating a more efficient defence response in the highest dietary supplementation levels tested.     

Crystalline Ropes of Metallic Carbon Nanotubes

Fullerene single-wall nanotubes (SWNTs) were produced in yields of more than 70 percent by condensation of a laser-vaporized carbon-nickel-cobalt mixture at 1200degreesC. X-ray diffraction and electron microscopy showed that these SWNTs are nearly uniform in diameter and that they self-organize into "ropes," which consist of 100 to 500 SWNTs in a two-dimensional triangular lattice with a lattice constant of 17 angstroms. The x-ray form factor is consistent with that of uniformly charged cylinders 13.8 +/- 0.2 angstroms in diameter. The ropes were metallic, with a single-rope resistivity of <10(-4) ohm-centimeters at 300 kelvin. The uniformity of SWNT diameter is attributed to the efficient annealing of an initial fullerene tubelet kept open by a few metal atoms; the optimum diameter is determined by competition between the strain energy of curvature of the graphene sheet and the dangling-bond energy of the open edge, where growth occurs. These factors strongly favor the metallic (10,10) tube with C5v symmetry and an open edge stabilized by triple bonds.     

Thermal and Chemical Properties of Gelatin from Tilapia (Oreochromis niloticus) Scale

ABSTRACT

Gelatin from the scale of Nile tilapia was extracted and characterized chemically, thermally, and structurally. Scales of Nile tilapia were subjected to acid pretreatment and extraction with water at 60°C. The process yielded 12.1% (m/m) on a dry basis. The 6.67% gelatin solution had a gel strength of 233.5 ± 14g. The amino acid composition revealed that 20.02% was comprised of imino acids and glycine (34.49%) as the most abundant amino acids. The scale gelatin had α1, α2, and β subunits and was thermally stable up to 200ºC. The Fourier transform infrared spectrum showed absorption in the regions of amides A, I, II, and III. The characterization of tilapia scale gelatin showed that the obtained product was similar to commercial gelatin, thereby demonstrating its potential application.     

Isotype patterns of immunoglobulins: hallmarks for clinical status and tissue parasite density in Brazilian dogs naturally infected by Leishmania (Leishmania) chagasi

The role of anti-leishmanial immune response underlying the susceptibility/resistance during canine visceral leishmaniasis (CVL) has been recognized throughout ex vivo and in vitro investigations. Recently, we demonstrated that immunoglobulin levels (Igs), as well as the parasite load are relevant hallmarks of distinct clinical status of CVL. To further characterize and upgrade the background on this issue, herein, we have evaluated, in Leishmania (Leishmania) chagasi naturally infected dogs, the relationship between tissue parasitism (skin, bone marrow, spleen, liver and lymph node), the CVL clinical status (asymptomatic (AD), with no suggestive signs of the disease; oligosymptomatic (OD), with maximum three clinical signs-opaque bristles; localized alopecia and moderate loss of weight; symptomatic (SD), serologically positive with severe clinical signs of visceral leishmaniasis), and the humoral immunological profile of anti-Leishmania immunoglobulins (IgG, IgG1, IgG2, IgM, IgA and IgE). Our major statistically significant findings revealed distinct patterns of tissue parasite density within L. chagasi-infected dogs despite their clinical status, pointing out the spleen and skin as the most relevant sites of high parasitism during ongoing CVL. Parasite density of bone marrow and spleen were the most reliable parasitological markers to decode the clinical status of CVL. Moreover, the parasite density of bone marrow better correlates with most anti-Leishmania Igs reactivity. Additionally, a prognostic hallmark for canine visceral leishmaniasis was found, highlighting strong correlation between IgG1 and asymptomatic disease, but with IgA, IgE and IgG2 displaying better association with symptomatic disease. The new aspects of this study highlighted pioneer findings that correlated the degree of tissue parasite density (low (LP), medium (MP) and high (HP) parasitism) with distinct patterns of anti-Leishmania Igs reactivity. In this scope, our data re-enforce the anti-Leishmania IgG but with IgA reactivity as the better marker for overall tissue parasitism. The association between clinical status, Ig profile and the tissue parasitism support a novel investigation on the impact of humoral immune response and susceptibility/resistance mechanism during ongoing CVL.     

A Far-Field Hydrothermal Plume from Loihi Seamount

An extensive helium plume in the north central Pacific emanates from Loihi Seamount on the flanks of Hawaii. The maximum helium signal is found at a depth of about 1100 meters, the same depth as the near-field plume directly above Loihi Seamount. Although this helium plume is strongest near Hawaii, where the 3He/4He ratio at a depth of about 1100 meters reaches values 28 percent above the atmospheric ratio, it can be detected quite clearly at latitude 24°N, over 400 kilometers to the north. Excess 3He is also present on the same isopycnal between 15°N and 20°N at 135°W, some 2000 kilometers east of the Hawaiian Islands.     

Expression of Genes Associated with Apoptosis in the Porcine Corpus Luteum During the Oestrous Cycle

The corpus luteum (CL) of the pig lacks luteolytic sensitivity (LS) to prostaglandin (PG) F‐2α until after day 12 of the oestrous cycle, but the mechanisms underlying this phenomenon are poorly understood. As luteolysis involves apoptosis, we hypothesized that critical apoptotic proteins may be deficient in CLs that lack LS. The specific aim of these studies was to examine mRNA expression and protein levels of apoptosis genes/proteins (BAX/Bax, BCLX/Bcl‐x, CASP3/Caspase‐3, CASP8/Caspase‐8, NFΚB1/NFκB, TP53/p53) in porcine CLs collected at different stages of the oestrous cycle. CLs were collected surgically, mRNA and protein extracted, and expression/levels analyzed by semi‐quantitative (SQ) PCR and Western blots, respectively. At the mRNA expression level, only BAX (maximal on day 4) and TP53 (maximal on day 7) showed significant variations during the oestrous cycle. At the protein level, only Bcl‐x and Caspase‐3 showed significant changes during the cycle; Bcl‐x decreased on day 13 and Caspase‐3 increased on day 13. It is concluded that apoptosis‐associated proteins (i.e. Bcl‐x and Caspase 3) may play a critical role in luteolytic sensitivity in the pig.     

Distribution of Mercury and Monomethylmercury in Sediments of Vigo Ria, NW Iberian Peninsula

Fifty four samples of surface sediments (1-cm of thickness) and a gravity core of 154-cm long were collected in the Vigo Ria, NW of Iberian Peninsula. In the laboratory the sediments were oven dried at 40°C, desegregated, homogenised and analyzed for total Hg, monomethylmercury (MMHg), Al, and particulate organic carbon (POC). Mercury in sediments varied within a broad range: 0.09 to 8.9 nmol g^?1 the higher concentrations being found in the shipyards and docks areas of Vigo port (southern–middle Ria zone). No correlation was found between Hg and POC. The good exponential correlation between total Hg and Al levels suggests that Hg is closely associated with the fine fraction of sediments. Monomethylmercury concentrations in surface sediments ranged between <1.4 (DL) and 8.5 pmol g^?1 being the spatial distribution similar to that observed for total Hg. The lack of correlations MMHg–Al and MMHg–POC suggests that in situ processes of methylation/demethylation are responsible for MMHg distribution rather than the sediment characteristics. Additionally, these processes appear mercury-dependent only for Hg concentrations above 2.5 nmol g^?1. On the basis of these results it was estimated that 155 kg of Hg (0.1% MMHg) are present in the surface sediments of Vigo Ria, being 61% of anthropogenic origin.     

AMMONIUM AND NITRATE IN SOIL AND RATOON SUGARCANE GROWN IN FUNCTION OF NITROGEN ON OXISOL

After harvest, sugarcane residues left on the soil surface can alter nitrogen (N) dynamics in the plant-soil system. In Oxisols, the nitrogen fertilizer applied had its effects on the levels of ammonium and nitrate in the soil, N concentration in the plant leaves, and on the growth and productivity of second ratoon plants. The N rates tested were of 0, 60, 120, 180, and 240 kg ha^?1. Each treatment was replicated four times. Four months after the experiment was started, ammonium and nitrate concentration in the soil, N levels in plant leaves, and plant growth were evaluated. Productivity was evaluated 11 months after the experiment was set. By increasing the content of mineral N in soil, plant growth variables reflected differences in the production of stems; however, it did not affect foliar N. The use of leaf analysis was not important to assess the nutritional status of nitrogen in the ratoon sugarcane. Nitrogen concentration in soil was affected by nitrogen fertilization, but not the N content in leaves. The rate of 138 kg N ha^?1enabled greater production of sugarcane stalks (140 t ha^?1).