Grass carp (Ctenopharyngodon idella) grazing on duckweed (Spirodela polyrhiza)

The aims of this experiment were (1) toquantify the ability of grass carp to processduckweed and (2) to assess indirect changes inwater chemistry and phytoplankton community,caused by grass carp feeding. Yearling grass carp sized 126 ± 7.7 mm (TL) and19.6 g in weight were kept in 9 laminate tanksof 1 m³ for 14 days. Two stockingdensities (2 and 6 fish per m³) anda control without fish were used. Standard growthrate (SGR) of grass carp fed exclusively onduckweed was 0.70% body weight (BW) d^–1and food conversion ratio (FCR) reached 2.0(average water temperature =21.1 ± 3.8 °C). Daily food intakewas 0.2 g of duckweed dry weight (DW), i.e.,1% of average BW of grass carp. SGR ofduckweed growing in 20 × 20 cm floatingenclosures, differed significantly[F(6,2) = 417.9; p = 0.002] between the twostocking densities of grass carp and thecontrol tanks (without fish). Mean SGR ofduckweed was 0.02 g g^–1 day^–1 and thehighest SGR was recorded in the control tanks.Both decrease in NH₄-N and increase inNO₂-N concentrations differedsignificantly between the treatments[F(2,2) = 45.3; p = 0.02 and F(2,2) = 19.2; p = 0.04 respectively]. Changes in other nitrogenand phosphorus components (NO₃-N, TN, TPand PO₄-P) caused by stocking of grasscarp were not significant. Biomass ofphytoplankton, dominated by filamentous algaeand blue-greens, increased proportionately tostocking density of grass carp. Althoughduckweed has a large potential for nutrientremoval, the most common pathway for thenutrients released through grass carp grazingif duckweed cover is loose is theirincorporation into phytoplankton biomass.     

Jojoba seed meal proteins associated with proteolytic and protease inhibitory activities

The jojoba, Simmondsia chinensis, is a characteristic desert plant native to the Sonoran desert. The jojoba meal after oil extraction is rich in protein. The major jojoba proteins were albumins (79%) and globulins (21%), which have similar amino acid compositions and also showed a labile thrombin-inhibitory activity. SDS-PAGE showed two major proteins at 50 kDa and 25 kDa both in the albumins and in the globulins. The 25 kDa protein has trypsin- and chymotrypsin-inhibitory activities. In vitro digestibility of the globulins and albumins resembled that of casein and soybean protein concentrates and was increased after heat treatment. The increased digestibility achieved by boiling may be attributed to inactivation of the protease inhibitors and denaturation of proteins.     

Trypanocidal activity of extracts and fractions of Bertholletia excelsa

Crude extracts and fractions of Bertholletia excelsa stem barks were tested for trypanocidal activity. Acetone and methanol extracts showed significant in vitro trypanocidal activity against trypomastigote form of Trypanosoma cruzi since in the concentration of 500 microg/ml, the parasites were reduced in 100% and 90.3% respectively, whereas the triterpene betulinic acid pure isolated from hexane extract presented 75.4%.     

Nature and Origin of Lipids in Clay Fractions from a Fluvisol in a Sewage Sludge Deposition Field

Few studies on free lipids in total solvent extracts from soil clay fractions directly measured by gas chromatography–mass spectrometry (GC/MS) have been reported so far. In this study, we aimed to examine the free lipids in the clay fraction separated from a Fluvisol profile on which sewage sludge was deposited 6 years ago and provide information on the sources, diagenetic processes and organic pollutants derived from the sludge. Clay fractions were separated from the four horizons of a Fluvisol and analysed for the biochemically stable lipid pool. The GC/MS analysis of the lipid fraction showed that lipid signatures were dominated by alkanes (C₁₇–C₃₃), alkanoic acids (C₁₂–C₁₈), alkanols (C₁₄–C₃₀), aromatic acids and phthalate esters. Sources of lipids show predominant bacterial contribution as shown by the alkane, fatty acids and n-alkanol distributions. The preservation of lipids of microbial origin in the clay fraction was revealed by the presence of even number, branched alkanes and short-chain and branched fatty acids. These results imply that similar pedogenic processes took place in this soil profile affected by hydromorphic conditions with some quantitative changes in the clay lipid compositions between different soil horizons. Some aromatic acids and xenobiotics such as phthalates were detected in the lipid extracts of the clay fractions in depth (0–85 cm) of the soil profile, which has implications for pollution of soils and ground waters in situations of sewage sludge deposition.     

Comparative performance of F1 hybrids and open-pollinated ‘Bell’ pepper varieties (Capsicum annuum L.) under suboptimal temperature regimes

Summary Two Bell pepper F₁ hybrids demonstrated a significant advantage over open-pollinated varieties under growing conditions of suboptimal temperatures. Both hybrids gave significantly higher marketable yields than most of the varieties compared with them.Early total yields were also significantly higher in both hybrids. Hybrid No 12 was significantly higher than all the other varieties in both early and overall marketable yields.Two experimental hybrids produced by the use of ms ₁ and ms ₂ genes were found to be as promising as the regular hybrids.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. 1972 Series, No 2245E.     

Species-specific sensitivity of earthworm coelomocytes to dermal metal (Cd,Cu, Ni,Pb, Zn) exposures: Methodological approach

Earthworm immune-competent cells (coelomocytes) can be adversely affected by soil metal contamination. The aim of the present paper was to perform comparative studies on the coelomocytes of four lumbricid species dermally exposed for 2 days to filter paper soaked with Ni, Cu, Zn, Cd, or Pb chlorides (1 mM). Coelomocytes were expelled by electro-stimulation, counted, and assayed ex vivo by flow cytometry and spectrofluorometry. The coelomocytes of Allolobophora chlorotica and Dendrobaena veneta contain both amoebocytes and riboflavin-storing eleocytes; consequently, they were subjected to assays based on flow cytometric quantification of autofluorescent eleocytes and spectrofluorometric measurement of riboflavin content in coelomocyte lysates. In Al. chlorotica, the number of coelomocytes, the percentage of eleocytes, and the amount of riboflavin were significantly lower in Cu-exposed worms although these cytometric parameters were less affected by Ni, Zn, Cd exposure, and entirely unaffected by Pb exposure. In D. veneta, such cellular effects were also only observed in Cu-exposed worms. The coelomic fluids of Aporrectodea caliginosa and Lumbricus rubellus are constitutionally impoverished of eleocytes; therefore, these species could not be subjected to assays measuring the riboflavin content of these granular cells. Rather, the amoebocytes of Ap. caliginosa and L. rubellus were subjected to flow cytometric measurements of in vitro neutral red uptake (NR). However, the NR uptake assay was technically demanding, requiring a strictly normalized incubation period over all samples to yield useful comparative data. In contrast, the riboflavin content in the coelomocyte lysates of eleocyte-rich species appears to be a robust and convenient immune-function biomarker of environmental stress.     

Riboflavin storage in earthworm chloragocytes and chloragocyte-derived eleocytes and its putative role as chemoattractant for immunocompetent cells

We have shown previously that riboflavin is stored in chloragosomes of chloragocyte-derived earthworm eleocytes what may have an adaptive value for worms vulnerable to soil-derived pathogen invasion. Thus, it is important to determine whether riboflavin stores are also present in earthworm species with low eleocyte counts, especially in the chloragocytes of their chloragogen tissue that surrounds the coelomic site of the intestine, and find out its putative roles in earthworm immunity. Experiments were performed on adult worms from 6 species. Freely floating coelomocytes (consisting of amoebocytes plus species-specific numbers of eleocytes) were extruded by mild electric shock and then chloragocytes from the same anaesthetized worm were mechanically detached into buffer. Both cell suspensions were analyzed by spectrofluorometry for riboflavin content. It turned out that riboflavin is stored in species-specific quantities in all investigated species. Riboflavin storage predominates in free coelomocytes of eleocyte-rich species (Eisenia andrei, Dendrobaena veneta, Allolobophora chlorotica) while in chloragocytes of species with few eleocytes (Lumbricus terrestris, L. rubellus, and Aporrectodea caliginosa). Upon a massive microbial impact, the coelomocytes (both amoebocytes and eleocytes) are involved in the formation of multicellular bodies encapsulating soil-derived pathogens, what is connected with enhanced coelomocyte mobility. Thus the second aim of the present investigation was to check if riboflavin can participate in coelomocyte accumulations. Tests performed in a 48-well chemotaxis chamber revealed that riboflavin behave as chemoattractant for coelomocytes of all investigated earthworm species, which may be one of mechanisms underpinning its immunomodulatory functions.     

Cone beam computed tomography and intraoral radiography for diagnosis of dental abnormalities in dogs and cats

The development of veterinary dentistry has substantially improved the ability to diagnose canine and feline dental abnormalities. Consequently, examinations previously performed only on humans are now available for small animals, thus improving the diagnostic quality. This has increased the need for technical qualification of veterinary professionals and increased technological investments. This study evaluated the use of cone beam computed tomography and intraoral radiography as complementary exams for diagnosing dental abnormalities in dogs and cats. Cone beam computed tomography was provided faster image acquisition with high image quality, was associated with low ionizing radiation levels, enabled image editing, and reduced the exam duration. Our results showed that radiography was an effective method for dental radiographic examination with low cost and fast execution times, and can be performed during surgical procedures.     

乳酸乳球菌乳脂亚种IMAU60064增殖培养基的优化

以分离自西藏那曲县罗玛镇传统发酵酸牦牛奶中的乳酸乳球菌乳脂亚种（Lactococcus lactis subsp．Cremoris）IMAU60064为试验菌株,研究其最佳的培养条件。对碳源、氮源、缓冲盐等培养基成分及培养条件进行优化,并采用响应面法对优选的碳源、氮源和缓冲盐类的组成含量进行优化,得到IMAU60064的增殖培养基为：葡萄糖23g／L、大豆蛋白胨11g／L、牛肉膏11g／L、胰蛋白胨5g／L、NaAC1．8g／L、K2HP041．2g／L、柠檬酸钠1．2g／L、MgSO4·7H200．4g／L、MnSO4·5H2O54mg／L、L-半胱氨酸盐酸盐0．5g/L、吐温80为1g／L。Lactococcus lactis subsp．cremorisIMAU60064在此增殖培养基中经30℃,14h培养活菌数可达到3．26×10^8cFu／mL,比在MRS中（6．54×10^7CFU／mL）提高近5倍。