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1.
A rapid and low cost procedure, the carbon immunoassay (CIA) test, was evaluated for the diagnosis of Toxoplasma gondii infections. Using a closely related parasite (Besnoitia jellisoni) as antigen, and homologous or heterologous immune sera, it was demonstrated by light and electron microscopy that CIA is a very reliable and specific test. As it is neither expensive nor time-consuming, it can be recommended for general and routine laboratory use. 相似文献
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Inmaculada Riba Enrique García-Luque Alejandra Maz-Courrau María Luisa González de Canales Tomás Ángel DelValls 《Water, air, and soil pollution》2010,212(1-4):329-336
This study assesses the effect of salinity in bioavailability and toxicity of Zn by means of laboratory bioassays by observing contamination in both sediment and water, accumulation of Zn in biological tissues, and histopathological damage in the gills and guts tissues of Ruditapes philippinarum clams, which were exposed to different types of sediments from the Gulf of Cádiz (SW Spain) as well as two dilutions of toxic mud coming from an accidental mining spill. With this objective, the coefficients of distribution (K D) for Zn between overlying water and sediments were calculated, the histopathological frequencies in the tissues of the gills and guts of clams were determined, and the biota-sediment bioaccumulation factors as well as the bioaccumulation factors were quantified in the different stations. Results showed that the greatest histopathological damages appeared when the salinity values decreased. Statistical results showed that salinity was inversely correlated with histopathological damage (p?<?0.01) for the lesion index for gills. The most outstanding results were observed in the two dilutions of toxic mud (0.3% and 7.9%) at a salinity value of 10. Salinity was inversely correlated with the concentration of Zn in biological tissues (p?<?0.05) and inversely correlated with the concentration of Zn in water and sediment. Zn mobilization to the overlying water is produced when salinity values decrease. 相似文献
5.
Juan Eugenio Álvaro María Teresa Lao Mourad Baghour Moumen Abdelmajid 《Journal of plant nutrition》2016,39(8):1057-1062
The growth and essential oil (EO) production of parsley were evaluated in response to salinity and nutrient solution concentrations in a soilless culture. Parsley plants that were 60 days old were potted in a coconut fiber and peat moss medium and were treated with four different nutrient solutions, including T1, T2, T3 and T4. The T1 nutrient solution was the standard, the T2 and T3 solutions contained incremental macronutrient concentrations with an electrical conductivity (EC) of up to 2.2 and 3.2 dS m?1, respectively, and the T4 solution was the same as T2 but with sodium chloride (NaCl) and an incremental macronutrient concentration with an EC of 3.2 dS m?1. Next, these plants were grown for 90 days in a greenhouse with natural daylight in Nador, Morocco. Shoot and root growth significant decreased with increasing EC. However, the salinity that resulted from the addition of NaCl did not affect plant growth in the nutrient solutions. The optimum obtained growth and EO production were 1.2 and 2.2 dS m?1, respectively. Consequently, the optimum EC value (based on the EO production) of parsley in the soilless culture was 1.2–2.2 dS m?1. 相似文献
6.
The viability of metapopulations in fragmented landscapes has become a central theme in conservation biology. Landscape fragmentation
is increasingly recognized as a dynamical process: in many situations, the quality of local habitats must be expected to undergo
continual changes. Here we assess the implications of such recurrent local disturbances for the equilibrium density of metapopulations.
Using a spatially explicit lattice model in which the considered metapopulation as well as the underlying landscape pattern
change dynamically, we show that equilibrium metapopulation density is maximized at intermediate frequencies of local landscape
disturbance. On both sides around this maximum, the metapopulation may go extinct. We show how the position and shape of the
intermediate viability maximum is responding to changes in the landscape’s overall habitat quality and the population’s propensity
for local extinction. We interpret our findings in terms of a dual effect of intensified landscape disturbances, which on
the one hand exterminate local populations and on the other hand enhance a metapopulation’s capacity for spreading between
habitat clusters. 相似文献
7.
A. ROSAS R. VÁZQUEZ‐DUHALT R. TINOCO A. SHIMADA L.R. DABRAMO M.T. VIANA 《Aquaculture Nutrition》2008,14(6):481-489
The kinetics of amino acid absorption in the proximal section of three fish species were studied using an everted intestine technique and a pancreatic digest of casein (Tryptone), as the model amino acid mixture. Fresh intestine of rainbow trout (Oncorhynchus mykiss) was used to set up the experimental system, and results were compared with those obtained using intestines from totoaba (Totoaba macdonaldi) and bluefin tuna fish (Thunnus orientalis). The kinetics of amino acid absorption was sigmoidal for all amino acids and for each species of fish tested. In general, specific absorptions of essential amino acids were higher than those of non‐essential ones. No correlation between the concentration of amino acids in the Tryptone solution and the corresponding absorptions was found. The maximum specific absorption rates of all amino acids for trout were 10 times higher than those determined for totoaba and bluefin tuna. The relative amounts of the different amino acids preferentially absorbed in all three species were different. Results obtained from the everted technique may be applicable to the design of formulated diets for large fish species with commercial value. 相似文献
8.
Raquel Lucas-González Manuel Viuda-Martos José Ángel Pérez-Álvarez Juana Fernández-López 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(1):67-73
The aim of the work was to study the influence of particle size in the composition, physicochemical, techno-functional and physio-functional properties of two flours obtained from persimmon (Diospyros kaki Trumb. cvs. ‘Rojo Brillante’ (RBF) and ‘Triump’ (THF) coproducts. The cultivar (RBF and THF) and particle size significantly affected all parameters under study, although depending on the evaluated property, only one of these effects predominated. Carbohydrates (38.07–46.98 g/100 g) and total dietary fiber (32.07–43.57 g/100 g) were the main components in both flours (RBF and THF). Furthermore, insoluble dietary fiber represented more than 68% of total dietary fiber content. All color properties studied were influenced by cultivar and particle size. For both cultivars, the lower particle size, the higher lightness and hue values. RBF flours showed high values for emulsifying activity (69.33–74.00 mL/mL), while THF presented high values for water holding capacity (WHC: 9.47–12.19 g water/g sample). The bile holding capacity (BHC) and fat/oil binding values were, in general, higher in RBF (19.61–12.19 g bile/g sample and 11.98–9.07, respectively) than THF (16.12–12.40 g bile/g sample and 9.78–7.96, respectively). The effect of particle size was really evident in both WHC and BHC. Due to their dietary fiber content, techno-functional and physio-functional properties, persimmon flours seem to have a good profile to be used as potential functional ingredient. 相似文献
9.
Viridiana Peraza-Gómez Antonio Luna-González Ángel I Campa-Córdova Melina López-Meyer Jesús A Fierro-Coronado & Píndaro Álvarez-Ruiz 《Aquaculture Research》2009,40(13):1481-1489
The protective effect of a probiotic mixture (PM) and antiviral plants, against the white spot syndrome virus (WSSV) in Litopenaeus vannamei , was evaluated in three experiments. The PM was composed of four lactic acid bacteria (LAB) and one yeast strain. The plant mixture was composed of Ocimum sanctum and commercial antiviral plants (VPH® , HSV® ). Shrimp in each experiment (weighing 2.7±0.7, 11.5±1.3, 11.70±2.5 g) were cultured in 120-L plastic tanks and fed twice a day with commercial feed plus additives (plants or bacteria and yeast). Animals were monitored for the occurrence of WSSV by single-step and nested PCR. The PM and powdered antiviral plants added to the commercial feed showed an increase in survival and a decrease in the prevalence of WSSV in shrimp. The results showed that both the PM and the powdered antiviral plants can provide protection for shrimp against WSSV. 相似文献
10.
J P Hanus H Guerrero E R Biehl C T Kenner 《Journal of the Association of Official Analytical Chemists》1979,62(1):29-35
A high pressure liquid chromatographic (HPLC) procedure is described for determining 13 polynuclear aromatic hydrocarbon (PNA) compounds in oysters at the 2 ppb level. These compounds are extracted from shellfish with acetonitrile and partitioned into petroleum ether; the petroleum ether is removed and the residue is saponified. The aromatic compounds are isolated by passing the saponifeid residue through silica gel and further purified and fractionated by muStyragel gel permeation chromatography. The in-ividual PNAs are then quantitatively determined by using a reverse phase HPLC column coupled to fluorescence, spectrophotometric, and 254 nm absorbance detectors in series. Recoveries from spiked samples generally were greater than 80%. 相似文献