Expression of Ripening-Related Genes in Prickly Pear (Opuntia sp.) Fruits

To throw light on the expression of ripening-related genes in prickly pear (Opuntia sp.) fruits and on the possible role of the gaseous hormone ethylene in nonclimacteric fruit ripening, cDNA fragments that showed high homologies with 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase cDNAs from other plants were cloned and partially characterized. Thus, the corresponding genes were accordingly named opaccs-1 and opacco-1, after Opuntia ACC synthase-1 and Opuntia ACC oxidase-1, respectively. Southern analysis suggests the presence of at least one copy of both genes, as well as other related homologous sequences in the Opuntia genome. Northern analysis of the opaccs-1 gene shows an enhanced expression in ripening fruit tissues, whereas opacco-1 expression is highly induced in ripe tissues with respect to the green fruits and mature cladodes. These results are in agreement with an active metabolic role of ethylene during nonclimacteric prickly pear fruit ripening. This is the first report on the analysis at the molecular level of ripening-related genes of the Opuntia genus.     

Evaluation of cerebrospinal fluid lactate and plasma lactate concentrations in anesthetized dogs with and without intracranial disease

The objectives of this study were to establish a reference interval for canine cerebrospinal fluid lactate (CSFL) and to compare CSFL and plasma lactate (PL) concentrations in anesthetized dogs with and without intracranial disease. Using a prospective study, canine blood and cerebrospinal fluid were collected for lactate analysis in 11 dogs with intracranial disease after undergoing magnetic resonance imaging (MRI) (Group ID-MRI), in 10 healthy dogs post-MRI (Group H-MRI), and in 39 healthy dogs after induction of anesthesia (Group H-Sx). Dogs were anesthetized for the procedures using different anesthetic protocols. Neurological scores (NS) and sedation scores (SS) were assessed pre-anesthesia in ID-MRI dogs. The CSFL reference interval [90% confidence interval (CI) for lower and upper limits] was 1.1 (1.0 to 1.2) to 2.0 (2.0 to 2.1) mmol/L. Mean ± SD CSFL concentrations were: ID-MRI, 2.1 ± 0.8; H-MRI, 1.6 ± 0.4; and H-Sx, 1.6 ± 0.2 mmol/L. There was a tendency for higher CSFL in dogs in the ID-MRI group than in those in the H-MRI or H-Sx groups (P = 0.12). There was agreement between CSFL and PL in ID-MRI dogs (P = 0.007), but not in dogs in H-MRI (P = 0.5) or H-Sx (P = 0.2). Of the ID-MRI dogs, those with worse NS had higher CSFL (r² = 0.44). The correlation between CSFL and PL in dogs with intracranial disease and between worse NS and higher CSFL warrants further investigation into the use of CSFL and PL for diagnostic and prognostic purposes.     

Lipid classes from marine species and meals intended for cephalopod feeding

In this study, HPTLC was used to make a quantitative analysis of the total lipid content (TL dry weight) and their classes in 39 samples, including molluscs, crustaceans, fish and meals in an attempt to identify those most suitable for formulating diets for cephalopods by reference to an index of nutritional quality (OI_LC: Oser’s index modified for lipid classes). All the crustaceans analysed (<10% TL), fish from artisanal fisheries such as Boops boops, Gadus poutassou, Mugil sp. and Gadus minutus (<10% TL) and the plant meals (TL < 5%) would cause fewer digestive problems than the fish that were a by-catch from fish farms (B. boops or Sparus aurata), pelagic species (Sardina pilchardus or Trachurus trachurus) or krill meal, which are characterised by their high lipid content (20–60% TL). These latter feeds were associated with neutral lipids, mainly triglycerides during the summer. Mytilus galloprovincialis, Carcinus maenas, G. poutassou, Mugil sp., S. pilchardus and G. minutus had a more appropriate lipid content and profile during the winter, when they showed a higher OI_LC due to the greater variety of polar lipid classes they contained. Phospholipids like PS, PI and PE seem to be limiting nutrients in cephalopods because of their high content (78–542, 41–309 and 152–2,114 mg/100 g, respectively) compared with the rest of the samples. None of the meals analysed showed a good nutritional balance per se and should only be used in conjunction with other foods.     

Influence of fish food and faecal pellets on short‐term oxygen uptake,ammonium flux and acid volatile sulphide accumulation in sediments impacted by fish farming and non‐impacted sediments

Sediment cores were taken from impacted and non‐impacted areas and subjected to different incubations: (i) uninoculated, (ii) inoculated with fish feed and (iii) inoculated with gilthead seabream (Sparus aurata) faeces. After inoculation (or not), the cores were incubated for 8 h and the following biogeochemical fluxes were determined: sediment oxygen uptake (SOU), total ammonia nitrogen flux (TAN_f) and the production of acid volatile sulphides (AVS‐S_p). The results showed that the impacted sediments had a more pronounced benthic metabolism than non‐impacted sediments. Correlations between the variables and factorial analysis showed that oxygen consumption caused by the organic enrichment appeared as the trigger for subsequent biogeochemical alterations. The addition of faeces led to proportionally higher benthic rates of SOU, TAN_f and AVS‐S_p than those obtained in the feed incubations. Although the feed is relatively sterile and does not create an oxygen demand until colonized by bacteria, the faeces are already richly colonized with fish gut bacteria and could start to consume oxygen without the lag phase experienced in the incubations with feed. The TAN_f values measured after the addition of feed or faeces seem to be more related to the leaching velocity of TAN than with the benthic flux, given the short incubation time.     

The proteolytic digestive activity and growth during ontogeny of Parachromis dovii larvae (Pisces: Cichlidae) using two feeding protocols

The proteolytic digestive activity and growth of Parachromis dovii larvae during the ontogeny were evaluated in a recirculation system using two feeding strategies during a 28-day period. Larvae were reared using two feeding protocols (three replicates each): (A) Artemia nauplii (at satiation), fed from exogenous feeding [8 days after hatching (DAH)] until 15 DAH followed by nauplii substitution by formulated feed (20 % day^?1) until 20 DAH and then formulated feed until 28 DAH; (B) formulated feed (100 % BW daily) from exogenous feeding until 28 DAH. Levels of acid (pepsin type) and alkaline digestive proteases as well as growth and survival of larvae were measured along the feeding period. Survival was high and similar between treatments: 98.9 ± 0.0 for Artemia, 97.3 ± 0.0 % for formulated feed. The specific growth rate for length and weight was higher in larvae fed with Artemia nauplii than in larvae reared with formulated feed: 3.4 ± 0.1 versus 1.8 ± 0.1 % day^?1 for body length (P = 0.009) and 12.2 ± 0.1 versus 6.5 ± 0.3 % day^?1 for body weight (P = 0.002). The acid and alkaline proteolytic activity was detected, in both treatments, from the beginning of the experiment, at 8 DAH. The total enzymatic activity (U larva^?1) for acid and alkaline proteases was higher in larvae reared with Artemia after 12 DAH, whereas the specific enzymatic activity was similar for both enzyme types in the two treatments. The results suggest that P. dovii larvae were capable to digest formulated diets from the beginning of exogenous feeding and that they could be reared with formulated feeds. However, the formulated feed used should be nutritionally improved because of the poor growth obtained in this research.     

Field performance of <Emphasis Type="Italic">Pinus halepensis</Emphasis> planted in Mediterranean arid conditions: relative influence of seedling morphology and mineral nutrition

In Mediterranean arid regions, relatively small planting stock has traditionally been used in an attempt to reduce drought susceptibility, though few studies have examined influences of initial seedling morphology and nutrition on long-term plantation establishment. We fertilized Pinus halepensis Mill. seedlings in the nursery with controlled release fertilizer (CRF) varying in formulations and rates; 9-13-18 and 17-10-10 (N-P-K) formulations at 3, 5 and 7 g l⁻¹ substrate plus an unfertilized control and we evaluated growth and survival 7 years after planting in arid conditions in Almería province, southeast Spain. Interactions between initial height and fertilizer treatments occurred during the first 3 years; initial size advantages of specific fertilizer treatments (7 g l⁻¹ of 9-13-18 and 17-10-10 at 3 g l⁻¹) persisted after 7 years. The largest and most nutrient-rich seedlings from 9-13-18 at 7 g l⁻¹ (41.0 cm tall, 4.4 mg of P per g of root tissue at time of planting) exhibited the highest survival after 7 years (79%), while survival declined to 42% for non-fertilized plants (12.9 cm tall and 0.6 mg of P per g of root tissue). Initial seedling morphological parameters were most consistently correlated with field performance. Root P concentration was the nutrient variable most closely related to survival. Our data emphasizes importance of longer-term experiments to accurately assess influences of nursery treatments on field responses, particularly in arid areas. We suggest that larger seedlings with greater nutrient reserves than are currently being used should be incorporated into Mediterranean plantations.     

Effect of <Emphasis Type="Italic">Acrocomia aculeata</Emphasis> Kernel Oil on Adiposity in Type 2 Diabetic Rats

The macauba palm (Acrocomia aculeata) is native of tropical America and is found mostly in the Cerrados and Pantanal biomes. The fruits provide an oily pulp, rich in long chain fatty acids, and a kernel that encompass more than 50% of lipids rich in medium chain fatty acids (MCFA). Based on biochemical and nutritional evidences MCFA is readily catabolized and can reduce body fat accumulation. In this study, an animal model was employed to evaluate the effect of Acrocomia aculeata kernel oil (AKO) on the blood glucose level and the fatty acid deposit in the epididymal adipose tissue. The A. aculeata kernel oil obtained by cold pressing presented suitable quality as edible oil. Its fatty acid profile indicates high concentration of MCFA, mainly lauric, capric and caprilic. Type 2 diabetic rats fed with that kernel oil showed reduction of blood glucose level in comparison with the diabetic control group. Acrocomia aculeata kernel oil showed hypoglycemic effect. A small fraction of total dietary medium chain fatty acid was accumulated in the epididymal adipose tissue of rats fed with AKO at both low and high doses and caprilic acid did not deposit at all.     

Assessing the potential use of two portable chlorophyll meters in diagnosing the nutritional status of plants

The SPAD-502 and the FieldScout CM 1000 chlorophyll meters were compared in their performance in diagnosing the nutritional status of plants. Leaves of a wide range of greenness were used to push the sensitivity of the tools to their limits. Both devices showed high reproducibility when used by different operators. The SPAD-readings were well-correlated with leaf nitrogen (N) concentrations, since leaves from heavily fertilized plants were not included in the sample population. The FieldScout-readings showed a marked saturation curve with the leaf N concentration, thus it cannot be used as a reliable N nutritional status index. The results also showed that the use of SPAD-502 in the diagnosis of the nutritional status of an orchard requires the establishment of specific critical concentrations for cultivars and sampling dates. The SPAD-502 appeared to have potential in the diagnosis of the nutritional status of the orchard for nutrients other than N.