Marine-Derived Chitosan Nanoparticles Improved the Intestinal Histo-Morphometrical Features in Association with the Health and Immune Response of Grey Mullet (Liza ramada)

Marine-derived substances are known for their beneficial influences on aquatic animals’ performances and are recommended to improve intestinal health, immunity, and anti-oxidative status. The present study investigates the role of chitosan nanoparticles on the intestinal histo-morphometrical features in association with the health and immune response of Grey Mullet (Liza ramada). Chitosan nanoparticles are included in the diets at 0, 0.5, 1, and 2 g/kg and introduced to fish in a successive feeding trial for eight weeks. The final body weight (FBW), weight gain (WG), and specific growth rate (SGR) parameters are significantly increased while feed conversion ratio (FCR) decreases by chitosan nanoparticles compared to the control (p < 0.05). The morphometric analysis of the intestines reveals a significant improvement in villus height, villus width, and the number of goblet cells in chitosan-treated groups in a dose-dependent manner. Additionally, there is a positive correlation between the thickness of the enterocyte brush border and the chitosan dose, referring to an increasing absorptive activity. Histologically, the intestinal wall of Grey Mullet consists of four layers; mucosa, sub-mucosa, tunica muscularis (muscular layers), and serosa. The histological examination of the L. ramada intestine shows a normal histo-morphology. The epithelial layer of intestinal mucosa is thrown into elongated finger-like projections, the intestinal villi. The values of hemoglobin, hematocrit, red blood cells (RBCs), total protein (TP), albumin, and globulin are significantly increased in fish fed 1, and 2 g/kg of chitosan nanoparticles compared to fish fed 0 and 0.5 g/kg (p < 0.05). The highest levels of TP and albumin are observed in fish fed 1 g/kg diet (p < 0.05). The lysozyme activity and phagocytic index are significantly enhanced by feeding chitosan nanoparticles at 0.5, 1, and 2 g/kg, whereas the phagocytic activity is improved in fish fed 1 and 2 g/kg (p < 0.05). The highest lysozyme activity and phagocytic index are observed in fish fed 1 g/kg. SOD is significantly activated by feeding chitosan nanoparticles at 1 g/kg. Simultaneously, glutathione peroxidase (GPx) and catalase (CAT) activities also are enhanced by feeding chitosan at 1 and 2 g/kg, compared to fish fed 0 and 0.5 g/kg (p < 0.05). The highest GPx and CAT activities are observed in fish fed 1 g/kg (p < 0.05). Conversely, the malondialdehyde (MDA) levels are decreased by feeding chitosan at 1 and 2 g/kg, with the lowest being in fish fed 1 g/kg (p < 0.05). To summarize, the results elucidate that L. ramada fed dietary chitosan nanoparticles have a marked growth rate, immune response, and anti-oxidative response. These improvements are attributed to the potential role of chitosan nanoparticles in enhancing intestinal histo-morphometry and intestinal health. These results soundly support the possibility of using chitosan nanoparticles at 1–2 g/kg as a feasible functional supplement for aquatic animals.     

Application of touchdown enzyme time release (TETR)-PCR for diagnosis of Chlamydophila abortus infection

Chlamydophila abortus-DNA was detected using a touchdown enzyme time-release (TETR)-polymerase chain reaction (PCR) assay as an improved test for sensitive and rapid diagnosis of abortion in small ruminants. Two hundred and fifty two placentae, liver or spleen tissue samples from aborting ewes and goats or aborted lambs and kids in which C. abortus infection was suspected were examined by TETR-PCR and the results were compared with cell culture. Sixty-five tissue samples were found to be TETR-PCR positive while only 56 samples were cell culture-positive. After resolution of discrepant samples with a confirmatory nested PCR assay, TETR-PCR had a sensitivity of 97% and a specificity of 99.5% while culture had a sensitivity of 84.8% and a specificity of 100%. The analytical sensitivity of the TETR-PCR assay was determined with DNA extracted from 4-fold serial dilution of C. abortus B577 culture and found to be 0.25 inclusion-forming unit per PCR. No reduction in the analytical sensitivity was noted when the assay was tested with mouse liver samples spiked with 4-fold serial dilution of C. abortus B577 culture. No target product was amplified when DNA from Chlamydophila pecorum was tested. TETR-PCR used in this study is a practical, rapid, sensitive and specific assay that could be used for the detection of C. abortus in infected tissue samples. We recommend the use of this assay as a supplemental diagnostic tool for detection of C. abortus in infected tissue samples.     

Addition of Leucaena-KX2 mulch in a shaded coffee agroforestry system increases both stable and labile soil C fractions

Agroforestry systems have the potential to increase sequestration of atmospheric carbon dioxide (CO₂) as soil organic carbon (SOC) because of the increased rates of organic matter addition and retention. However, few studies have characterized the relative stability of sequestered SOC in soil. We characterized SOC storage in aggregate size and chemical stability classes to estimate the relative stability of SOC pools after the addition of Leucaena-KX2 pruning residues (mulch) from 2006 to 2008 in a shaded coffee agroforestry system in Hawaii. Soil samples were separated by microaggregate isolation, density flotation and dispersion, and acid hydrolysis, resulting in five distinct fractions that differed in relative stability: coarse particulate organic matter (POM), fine POM, microaggregate-protected POM, silt + clay hydrolyzable soil organic matter (SOM), and silt + clay non-hydrolyzable SOM. With mulch addition, the fine POM fraction increased. There was also a shift in the proportion of SOC to more stable silt + clay fractions. In the absence of mulch there was no significant change in SOC fractions. Given that the turnover time of SOC in silt + clay fractions is on the order of decades to centuries, the potential benefits of active shade management and mulching compensate for the loss of C sequestration in tree biomass from pollarding.     

The flavonoid glycosides and procyanidin composition of Deglet Noor dates (Phoenix dactylifera)

The fruits of the date palm (Phoenix dactylifera) are consumed throughout the world and are an important part of the diet in the Middle East. Dates at the rutab and tamar maturity and ripening stages contain a wide array of phenolic antioxidants, but little is known about the composition of phenolic compounds in dates at the khalal stage of ripening. In the current study, the flavonoid glycoside and procyanidin compositions of dates of the cultivar Deglet Noor harvested at the khalal stage of maturity were characterized using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI/MS/MS). Procyanidin oligomers through decamers were identified in extracts of these dates. Higher molecular weight polymers, undecamers through heptadecamers, were also apparent from mass spectra. Thirteen flavonoid glycosides of luteolin, quercetin, and apigenin, 19 when considering isomeric forms, were also identified. Mass spectra indicate that both methylated and sulfated forms of luteolin and quercetin are present as mono-, di-, and triglycosylated conjugates whereas apigenin is present as only the diglycoside. LC-ESI/MS/MS spectra indicate that quercetin and luteolin formed primarily O-glycosidic linkages whereas apigenin is present as the C-glycoside.     

Acidulated activation of phosphate rock enhances release,lateral transport and uptake of phosphorus and trace metals upon direct-soil application

Phosphate rock (PR) was activated via acidulation with HCl, EDTA, and oxalic acid to enhance its reactivity. The release, lateral transport, and uptake of phosphorus (P) along with trace metals from pristine and activated PRs were investigated in a soil micro-block system over a period of 27 days, using wheat (Triticum aestivum L.) plants. Significantly (p < 0.05) higher amounts of available soil P, Fe, Mn, and Zn were released from all the PRs after application to soil within first 9 days of seedling transplantation, while the release of other trace metals (Cd, Co, Cr, Cu, Ni, and Pb) was minimal (<1.2 mg kg^?1). On cumulative basis, APR-O (oxalic acid activated PR) was the most efficient amendment releasing 164% more available P, followed by APR-E (EDTA activated PR) releasing 130% more available P, compared to the pristine PR. Similar results were also observed in the release of available Fe, Mn, Zn, and other trace metals. The highest diffusive mass fluxes for available P, Mn, Fe, and Zn in soil were observed after 3 days of seedling transplantation, which reduced subsequently. The uptake of P, Fe, Mn, and Zn by wheat plants was increased by 394%, 715%, 92%, and 91%, respectively, in APR-O application compared to the pristine PR, while it was increased by 280%, 188%, 16%, and 27%, respectively, in APR-E application compared to the pristine PR. Subsequently, APR-O and APR-E amendments resulted in enhanced shoot lengths, root lengths, shoot dry matter, and root dry matter contents of wheat plants. Hence, it was concluded that activation of PR with oxalic acid and EDTA prior to direct soil application may enhance the reactivity of PR and could serve as a cost-effect fertilization strategy for higher wheat crop production.     

Genetic architecture of plant height in maize phenotype‐selected introgression families

This study aimed at developing, characterizing and evaluating two maize phenotypic‐selected introgression libraries for a collection of dominant plant height (PHT)‐increasing alleles by introgressing donor chromosome segments (DCS) from Germplasm Enhancement of Maize (GEM) accessions into elite inbred lines: PHB47 and PHZ51. Different backcross generations (BC₁‐BC₄) were developed and the tallest 23 phenotype‐selected introgression families (PIFs) from each introgression library (PHB47 or PHZ51) were selected for single nucleotide polymorphism genotyping to localize DCS underlying PHT. The result shows that most PIFs carrying DCS were significantly (α = 0.01) taller than the respective recurrent parent. In addition, they contained larger donor genome proportions than expected in the absence of selection or random mating across all BC generations. The DCS were distributed over the whole genome, indicating a complex genetic nature underlying PHT. We conclude that our PIFs are enriched for favourable PHT‐increasing alleles. These two libraries offer opportunities for future PHT gene isolation and allele characterization and for breeding purposes, such as novel cultivars for biofuel production.     

利用Aster高分辨率卫星图像估测灌溉小麦叶绿素（摘选）

无损识别作物属性为了解作物对各种环境影响的反应提供一种快速、准确的方法。作物叶绿素含量是判断作物健康情况和估测作物产量的重要指标。近年来,在局地和大尺度下通过遥感技术测定作物参数已作为地域特性管理的有力工具。在区域尺度上,评估了通过高分辨率卫星图像预测小麦属性的潜力。植被指数NDVI、RVI、GNDVIbr和其他波段比值都来自于Aster影响和相关作物叶绿素含量。通过导出植被指数,证明了利用Aster高分辨率卫星影像映射作物叶绿素含量空间变化的有效性。NDVI和红绿波段比被作为评价小麦叶绿素含量的敏感性指标（R=0.73和R=0.72）。结果表明,在区域范围内利用高空间分辨率卫星影像取得作物叶绿素水平对评估作物状况是一种行之有效的方法。      

Effect of taurine supplementation on the metabolism and body lipid‐to‐protein ratio in juvenile Atlantic salmon (Salmo salar)

Previously, we reported that methionine intake determined the taurine concentration in the liver of on‐growing Atlantic salmon fed plant protein diets. Further, the methionine intake and/or the increased taurine concentration following increased methionine intake affected the liver lipid metabolism. The following study therefore aimed to test whether taurine affected the growth or the type of growth when added in high plant protein diets naturally low in taurine but equal and adequate in dietary methionine. Juvenile Atlantic salmon [initial body weight (BW) of 2 g] were fed plant protein diets (16.5% fishmeal), which were supplemented with taurine or not for a period of 56 days. As a control for growth and normal metabolism, a fishmeal‐based commercial diet (68% fishmeal) was used. Supplementation with taurine to high plant protein diets had a slightly negative effect on weight gain, but the final body weight was not different. Interestingly, the pool of free amino acids in the liver and muscle was significantly higher in fish fed the supplemented diet as compared with fish fed the plant protein diet without taurine supplementation. Liver polyamine concentration was higher in fish fed the supplemented diet than in fish fed the similar diet without supplementation. Additionally, juvenile salmon fed the plant‐based diet supplemented with taurine had a lower body lipid‐to‐protein ratio due to a reduced whole‐body lipid content, while the whole‐body protein content was similar between treatments. Our study thus indicates that the addition of a low concentration of taurine to high plant protein diets interacts with lipid metabolism and storage, concomitantly affecting the general metabolism as the concentrations of the free amino acids and polyamines in the liver were significantly higher. The possible reasons for these changes are discussed.     

Antioxidant potential of sesame (Sesamum indicum) cake extract in stabilization of sunflower and soybean oils

Recently natural antioxidants have gained increased interest because natural food ingredients are safer than synthetic ones. Antioxidant activities and protective effects of sesame cake extract (SCE) in stabilizing sunflower oil (SFO) and soybean oil (SBO) were tested. Since different antioxidant compounds have different mechanisms of action, 2,2-azinobis (3-ethylbenzthiazoline sulfonate) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, and β-carotene/linoleic acid test system were used to assess the antioxidant efficacy of SCE. Total phenolic, flavonoid and flavonol contents in SCE were 1.94 (mg gallic acid equivalent (GAE) g⁻¹ dry weight (DW)), 0.88 (mg quercetain equivalent (QE) g⁻¹ DW), and 0.40 (mg QE g⁻¹ DW), respectively. Protective effects of SCE in stabilizing SFO and SBO were tested, compared to synthetic antioxidants, by measuring their peroxide values (PV), conjugated dienes (CD), conjugated trienes (CT) and p-anisidine value during accelerated storage. Results indicated that SCE exhibited stronger antioxidant activity in SFO and SBO than butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), while its antioxidant activity was less than that of tert-butyl hydroquinone (TBHQ).     

蚯蚓粪对土壤环境质量和作物生长影响的研究现状与展望

蚯蚓粪是一种优质、安全的天然有机肥料,对土壤环境质量和作物生长具有明显的改善和促进作用。综述蚯蚓粪的性质及其在改善土壤理化性状、提高土壤肥力和促进作物生长方面的研究现状,并提出了当前研究存在的局限和对未来工作的展望。