Performance and nutrient dynamics of holm oak (<Emphasis Type="Italic">Quercus ilex</Emphasis> L.) seedlings in relation to nursery nutrient loading and post-transplant fertility

Holm oak (Quercus ilex L.) seedlings were exponentially (E) nutrient loaded using incremental increases in fertilizer addition or conventionally (C) fertilized using a constant fertilizer rate during nursery culture. The fertility treatments (mg N plant⁻¹) were control (0), 25E, 100E, and 100C. Subsequently, 1-year-old plants were transplanted under simulated soil fertility gradients in a greenhouse to evaluate effects of nutrient loading and post-transplant fertility on seedling performance. Post-transplant fertility consisted of fertilizing plants at two rates (0 vs. 200 mg N plant⁻¹). A water-soluble fertilizer 20-20-20 was supplied in both nursery and post-transplant experiments. Nutrient loading increased plant N content by 73% in 100E and by 75% in 100C relative to controls, although no significant differences were detected between constant and exponential fertilization regimes at the 100 mg N plant⁻¹ rate. When transplanted, nutrient loading promoted post-transplant root growth relative to shoot, implicating potential to confer competitive advantage to loaded holm oak seedlings after trans-planting. In contrast, post-transplant fertility increased new shoot dry mass by 140% as well as N, P and K content relative to controls. Results suggest that holm oak seedlings can be successfully nutrient loaded in the nursery at higher fertility rates, improving its potential to extend new roots, but alternative fertilization regimes and schedules that better fit nutrient availability to the growth rhythm and conservative strategy of this species must be tested.     

Effect of emerged shipment on the physiological condition of the adductor muscle in adult giant lion's paw scallop Nodipecten subnodosus (Sowerby 1835)

Currently, there is an increasing interest in shipping live adult scallops to markets and broodstock to hatcheries; nevertheless, information about the shipping effect on live scallops physiology is very scarce. In a previous study, a method in emersion was developed to ship scallop seed out of water, but it was not known whether this method is useful to transport adult organisms. As a consequence, the purpose of this study was to evaluate the effects of transportation by the emersion method on the physiological status of the adductor muscle of adult giant lion's paw scallop. Live specimens were packaged in a container and transported in emersion for 11 h. Six scallops were frozen in a farm and a similar number were frozen as soon as they arrived to the laboratory. Physiological indices were determined in each lot and the survival was estimated 24 h after re‐immersion. As a result of the transportation, a significant loss (P<0.05) of total carbohydrates, glycogen, adenosine 5′‐triphosphate and adenilated energetic charge, and a significant increase (P<0.05) in the free amino acids concentration were observed. Eighty‐eight per cent survival was achieved; therefore, we conclude that this method is appropriate for shipping live adult scallops of Nodipecten subnodosus.     

Supercritical fluid extraction of pesticides from a table-ready food composite of plant origin (gazpacho)

Supercritical fluid carbon dioxide extraction (SFE) has been evaluated for the extraction of 17 organohalogen and organophosphate pesticides in gazpacho (a table-ready food composite containing crude vegetables, white bread, vegetable oil, water, and other minor components) using anhydrous magnesium sulfate as drying agent. The effects of different parameters, such as fat content in gazpacho composites, magnesium sulfate/gazpacho ratio, supercritical fluid volume, pressure, temperature, and static modifier additions, on SFE recoveries from spiked gazpacho samples have been studied. Analyses were performed by gas chromatography (GC) with flame photometric (FPD), electron capture (ECD), and mass spectrometry (MSD) detectors. In most experiments, recoveries obtained for the nonpolar organohalogen pesticides were lower than those obtained for the most polar organophosphate pesticides, but overall pesticide recoveries determined by using the optimal SFE conditions indicate that SFE could be used to determine pesticide residue levels in gazpacho.     

Specific polymerase chain reaction for differential diagnosis of Dirofilaria immitis and Dipetalonema reconditum using primers derived from internal transcribed spacer region 2 (ITS2)

Both Dirofilaria immiti and Dipetalonema reconditum may be found in blood of infected dogs but it is not easy to distinguish D. immitis from D. reconditum in morphology. We cloned and sequenced the contiguous internal transcribed spacer (ITS) region, ITS1-5.8S-ITS2, of these two different parasites and published on GenBank as AF217800 for D. immiti and AF217801 for D. reconditum in this study. We designed two pairs of specific primers derived from ITS2 being used for polymerase chain reaction (PCR). The amplicons of ITS2 from D. immiti and D. reconditum are 302 and 348bp, respectively. Moreover, the limitation for amplifying ITS2 gene using this PCR demonstrated that 1 x 10(-2) microfilaria of each species of parasite smashed or even with mixed samples could be detected and the PCR products were predicted as the same as that described above. Thus, D. immiti and D. reconditum could be differentially diagnosed by this specific PCR. Seventeen clinical cases were evaluated and all of them were correctly identified. In this study, ITS1-5.8S-ITS2 of D. immiti or D. reconditum were the first time sequenced and analyzed. No significant similarity of ITS1 and ITS2 between D. immiti and D. reconditum could be observed.     

Vermicomposting leachate as liquid fertilizer for the cultivation of sugarcane (Saccharum sp.)

In vermicomposting, the main product is the worm casts, but a leachate is generated that contains large amounts of plant nutrients. This leachate is normally diluted to avoid plant damage. We investigated how dilution of vermicompost leachate combined with different concentrations of nitrogen (N) - phosphorus (P) - potassium (K) triple 17 fertilizer, and polyoxyethylene tridecyl alcohol as dispersant and polyethylene nonylphenol as adherent to increase efficiency of fertilizer uptake, affected sugarcane plant development. The vermicomposting leachate with pH 7.8 and electrolytic conductivity 2.6 dS m^?1, contained 834 mg potassium (K) l^?1, 247 mg nitrate (NO₃^?) l^?1 and 168 mg phosphate (PO₄^3?) l^?1, was free of pathogens and resulted in a 65% germination index. Vermicompost leachate did not inhibit sugarcane growth and mixed with 170 g l^?1 NPK triple 17 fertilizer resulted in the best plant development. No dispersant or adherent was required to improve plant height and stem development.     

Influence of Salinity in the Bioavailability of Zn in Sediments of the Gulf of Cádiz (Spain)

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.     

Classification of wine and alcohol vinegar samples based on near-infrared spectroscopy. Feasibility study on the detection of adulterated vinegar samples

Near-infrared (NIR) spectroscopy was used to discriminate between wine vinegar (red or white) and alcohol vinegar. One orthogonal signal correction method (OSC) was applied on a set of 73 vinegar NIR spectra from both origins and artificial blends made in the laboratory in order to remove information unrelated to a specific chemical response (tartaric acid), which was selected due to its high discriminant ability to differentiate between wine vinegar and alcohol vinegar samples. These corrected NIR spectra, as well as raw NIR spectra and 14 physicochemical variables, were used to develop separate classification models using the potential functions method as a class-modeling technique. The aforementioned models were compared to evaluate the suitability of NIR spectroscopy as a rapid method for discriminating between vinegar origins. The transformation of vinegar NIR spectra by means of an orthogonal signal correction method prompted a notable improvement in the specificity of the constructed classification models. The classification model developed was then applied to artificial vinegar blends made in the laboratory to test its capacity to recognize adulterated vinegar samples.     

Histological alterations in gills of shrimp Litopenaeus vannamei in low‐salinity waters under different stocking densities: Potential relationship with nitrogen compounds

Two experimental modules with different stocking densities (M1 = 70 and M2 = 120 shrimp /m²) were examined weekly over a culture cycle in tanks with low‐salinity water (1.9 g/L) and zero water exchange. Results showed survival rates of 87.7 and 11.9% in M1 and M2, respectively. Water temperature, pH, dissolved oxygen, electrical conductivity and chlorophyll a were not significantly (p > .05) different between modules. In contrast, the concentrations of nitrogen compounds were significantly (p < .05) different between modules, except nitrite‐N (M2 were 2.31 ± 1.38 mg/L N‐TAN, 0.18 ± 0.49 mg/L N‐NO₂^? and 6.83 ± 6.52 mg/L N‐NO₃^?; in M1: 0.97 ± 0.73 mg/L N‐TAN, 0.05 ± 0.21 mg/L N‐NO₂^? and 0.63 ± 0.70 mg/L N‐NO₃^?). When waters of both modules reached higher levels of ammonia and nitrite, histological alterations were observed in gills. The histological alterations index (HAI) was higher in M2 (5‐112) than in M1 (2‐22).     

Characterization of Collagen from Different Discarded Fish Species of the West Coast of the Iberian Peninsula

ABSTRACT

Skin collagen of six discarded fish species was analyzed and compared. Acid soluble collagen (ASC) was extracted; a characteristic sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profile for type I collagen was obtained, except for Chimaera mostrosa. Contents of collagen calculated from HPro (31.85% average) were higher than those determined from ASC extracts (17.75% average), with Galeus spp. being the species with the higher percentage. Amino acid analysis revealed the typical composition of collagen, with very few differences among species. Specific profiles were obtained after protease digestion. Denaturation temperature of ASC correlated well with imino and hydroxyproline contents.

Results demonstrate the feasibility of using the obtained collagens in different industrial applications.