Tree density and site quality influence on Pinus halepensis Mill. reproductive characteristics after large fires

In Spain, many Pinus halepensis Mill. forests have been seriously affected by significant forest fires in the past decade, in 1994 alone, more than 100 000 ha were burned in Eastern Spain. In order to study the reproductive characteristics of P. halepensis after forest fires, six locations were selected in four areas affected by serious fires in the summer of 1994, and the following different precipitation zones were studied: dry-subhumid, dry and semi-arid. Ten years after the fires, data relevant to the production of pine cones: serotinous (grey), mature (brown), immature (green) and opened cones, was collected from areas with natural post-fire regeneration. Various cone and seed characteristics, such as pine cone seed number and weight, and germination percentage, were measured. The results showed greater production of cones and strobili in high-density sites. The biggest cone sizes (volume) and seed number per cone were related to site quality (dry-subhumid precipitation zone). Also, viability and germination percentages were higher with better site quality, with significant differences in values for serotinous and non-serotinous cones. Despite these differences, the canopy seed bank was large enough to ensure regeneration in this area for this age stand.     

Growth and nutrient accumulation of Brazil nut trees (Bertholletia excelsa) in agroforestry at different fertilizer levels

The Brazil nut tree(Bertholletia excelsa) is a frequent component of agroforestry systems in the Amazon because of its adaptation to nutrient-poor upland soils and multiple uses.We investigated the aboveground biomass production(kg dry weight),nutrient uptake and requirements(N,P,Ca,Mg,K) of Brazil nut trees of different sizes grown under agroforestry conditions and fertilized at different levels.Eight of 70 experimental trees with different size were harvested and stem,branches and leaves were separated.Nutrient contents were determined for three trees of varying size.Average tree growth was fast,but variability was high,suggesting considerable potential for the improvement of this economically important species.The trees responded to increased levels of fertilizer and lime with significantly increased foliar nutrient contents and growth,probably because of the improved availability of Mg and Ca for which the species seems to have a relatively high demand.In contrast to Brazil nut trees grown in forest or dense plantations,the agroforestry trees invested a substantial part of their biomass and nutrients in large branches and developed spreading crowns.To improve stem form,reduce competition with associated crops for light and recycle nutrients,regular pruning of lower branches or planting arrangements that favor self-pruning are recommended.These measures would also increase the recycling of Ca and Mg,large quantities of which are contained in the branches.     

COMBINATION OF RADIATION THERAPY AND FIROCOXIB FOR THE TREATMENT OF CANINE NASAL CARCINOMA

Carcinomas represent two‐thirds of canine nasosinal neoplasms. Although radiation therapy (RT) is the standard of care, the incidence of local recurrence following treatment is high. Cyclooxygenase‐isoform‐2 (COX‐2) is expressed in 71–95% of canine nasal carcinomas and has been implicated in tumor growth and angiogenesis. Accordingly, COX‐2 inhibition seems rational to improve outcome. Dogs with histologically confirmed, previously untreated nasal carcinomas were randomized to receive the combination of a selective COX‐2 inhibitor (firocoxib) and palliative RT (Group 1) or RT and placebo (Group 2). Patients were regularly monitored with blood tests, urinalysis, and computed tomography. Pet owners were asked to complete monthly a quality‐of‐life questionnaire. Twenty‐four dogs were prospectively enrolled. According to Adams modified system, there were five stage 1, five stage 2, three stage 3, and 11 stage 4 tumors. Two dogs had metastases to regional lymph nodes. Median progression‐free interval and overall survival were 228 and 335 days in Group 1 (n = 12) and 234 and 244 days in Group 2 (n = 12). These differences were not statistically significant. The involvement of regional lymph nodes was significantly associated with progression‐free interval and overall survival (P = 0.004). Quality of life was significantly improved in Group 1 (P = 0.008). In particular, a significant difference was observed for activity and appetite. Although not providing a significant enhancement of progression‐free interval and overall survival, firocoxib in combination with RT is safe and improved life quality in dogs with nasal carcinomas.     

Milk production,intake, digestion,blood parameters,and ingestive behavior of cows supplemented with by-products from the biodiesel industry

This study aimed to evaluate the intake, digestion, blood parameters, and feeding behavior of crossbred dairy cows (Holstein?×?Gir) managed on Panicum maximum Jacq. cv. Tanzania-1 and provided supplementation with groundnut cake, sunflower cake, or palm kernel cake (to replace soybean meal). Sixteen cows were randomly assigned in a Latin square design with four treatments and four experimental periods. The consumption of nutrients from the pasture did not vary between experimental treatments. Cows receiving the palm kernel cake supplement had a reduced crude protein, non-fibrous carbohydrate, and total digestible nutrient intake and an increase in the average consumption of ether extract. There was also a reduction in the digestibility of dry matter. The inclusion of supplements in the diet did not influence the average time spent eating, ruminating, or resting. The mean values of respiratory and heart rates showed thermal comfort during the trial period. There was a reduction in blood urea nitrogen with palm kernel cake supplementation, and the values of total protein, albumin, and glucose were also significantly different with this supplement. It is recommended that cakes of groundnut cake and sunflower cake seed be used for a total replacement of soybean meal supplements for lactating cows, but the use of palm kernel cake is not recommended.

     

Detection of land animal remains in fish meals by the polymerase chain reaction-restriction fragment length polymorphism technique

In the present study a technique was developed with the aim of guaranteeing the composition and security of fish meals, since it allows verification of whether these meals contain land animal remains. The method is based on polymerase chain reaction (PCR) and length polymorphism, followed by a restriction fragment length polymorphism (RFLP). Specific primers for every species were designed and calibrated, generating exclusively a PCR product with a specific size when DNA for each species was present in the sample. This technique allows the detection of land animal remains in fish meals, specifically cow, chicken, pig, horse, sheep, and goat. The identity of the PCR products can be confirmed by RFLP analysis using only one restriction enzyme. The selected restrictase generated one characteristic restriction profile for every species included in this study. The detection limit of this method was calculated by using mixtures of fish meals in different proportions and meal that exclusively contained remains of one of these land species studied. The analytical strategy herein proposed was applied to fish and meat meals, giving good results, both in the analyzed standards and in commercial samples.     

Strecker degradation of phenylalanine initiated by 2,4-decadienal or methyl 13-oxooctadeca-9,11-dienoate in model systems

The reaction of 2,4-decadienal and methyl 13-oxooctadeca-9,11-dienoate with phenylalanine was studied to determine if alkadienals and ketodienes are able to produce the Strecker-type degradation of amino acids to the corresponding Strecker aldehydes. When reactions were carried out at 180 degrees C, both carbonyl compounds degraded phenylalanine to phenylacetaldehyde, among other compounds. The yield of the phenylacetaldehyde produced depended on the reaction pH and increased linearly with both the amount of the lipid and the reaction time. The yield of this conversion was approximately 8% when starting from decadienal and approximately 6% when starting from methyl 13-oxooctadeca-9,11-dienoate, and the reaction rate was lower for the ketone than for the aldehyde. Simultaneous to these reactions, the lipid was converted into pyrrole, pyridine, or aldehyde derivatives as a result of several competitive reactions. In particular, 9-14% of the decadienal was converted into hexanal under the assayed conditions. All these reactions are suggested to be produced as a consequence of the oxidation of the alkadienal or the ketodiene to the corresponding epoxyalkenal or unsaturated epoxyketone, which were identified in the reaction mixtures by GC-MS. All these results suggest that alkadienals and ketodienes, which are quantitatively important secondary lipid oxidation products, can degrade amino acids to their corresponding Strecker aldehydes. Therefore, under appropriate conditions, these products are not final products of the lipid oxidation and can participate in carbonyl-amine reactions analogously to other lipid oxidation products with two oxygenated functions.     

Solid foodstuff supplemented with phenolics from grape: antioxidant properties and correlation with phenolic profiles

Osmotic dehydration was assessed as an operation for supplementing a solid foodstuff (a gel was used as the model food) with grape phenolics from a concentrated red grape must to increase its antioxidant properties. The model food was processed for up to 24 h, and the osmotic pressure was adjusted by diluting the concentrated red grape must. In all conditions tested, low molecular weight phenolics (相似文献   

Use of natural and modified cyclodextrins as inhibiting agents of peach juice enzymatic browning

Although cyclodextrins (CDs) have been successfully used as antibrowning agents in different fruit juices, no research has studied the effect of these compounds on enzymatic browning in peach juice. In this paper, the color of fresh peach juice was evaluated in the presence of two types of natural (alpha-CD and beta-CD) and a modified (maltosyl-beta-CD) CD, and the effectiveness of these compounds as browning inhibitors was determined using the color space CIELAB system. Moreover, to clarify the mechanism by which CDs inhibit peach juice enzymatic browning, the process was kinetically modeled in the absence and presence of CDs using a colorimetric method; the apparent complexation constants between the mixtures of diphenols present in peach juice and some types of CD were calculated. The results show that the highest affinity constant was presented by alpha-CD (Kc = 18.31 mM-1) followed by maltosyl-beta-CD (Kc = 11.17 mM-1), whereas beta-CD was incapable of inhibiting peach juice enzymatic browning. Keywords: Cyclodextrin; browning; peach; juice; color; polyphenol oxidase.     

D-amino acid formation in sterilized alkali-treated olives

The occurrence of d-amino acids in commercial ripe olives, a well-known sterilized alkali-treated product, was investigated by high-performance liquid chromatography (HPLC) with precolumn automatic derivatization. Absolute amounts of D-amino acids were in total 18.6-38.2 mg/100 g edible portion. The major D-amino acids were D-aspartic acid, D-glutamic acid, D-serine, and D-leucine. Furthermore, to evaluate the effects of sterilization time and olive pH on amino acid racemization, a simulated processing of green ripe olives was carried out. Serine (both free and bound form) was the most-racemized amino acid after heat treatment. Sterilization (15-35 min at 121 degrees C) increased the racemization values of both free and protein-bound amino acids, although in case of protein-bound phenylalanine the increase was not statistically significant. With an increase of pH from 8 to 10 units, the racemization values of all amino acids increased significantly, except for free forms of aspartic and glutamic acids. In general, the effects of the sterilization time and olive pH on total concentration (L + D enantiomers) of each amino acid were also significant.