Influence of stand,site and meteorological variables on the maximum leaf area index of beech,oak and Scots pine

Different multiple linear regression models of maximum leaf area index (LAI_max) based on stand characteristics, site quality, meteorological variables and their combinations were constructed and cross-validated for three economically important tree species in Flanders, Belgium: European beech (Fagus sylvatica L.), Pedunculate oak (Quercus robur L.) and Scots pine (Pinus sylvestris L.). The models were successfully tested on similar datasets of experimental sites across Europe. For each species, ten homogeneous and mature stands were selected, covering the species’ entire stand productivity range based on an a priori site index classification. LAI_max was derived from measurements of leaf area index (LAI) made by means of hemispherical digital photography over the whole growing season (mid-April till end October 2008). Species-specific models of LAI_max for beech and oak were mostly driven by management practice affecting stand characteristics and tree growth. Tree density and dominant height were main predictors for beech, while stand age and tree-ring growth were important in the oak models. Scots pine models were more affected by site quality and meteorological variables. The beech meteorological model showed very good agreement with LAI at several European sites. Scots pine’s stand model predicted well LAI across Europe. Since the species-specific models did not share common predictors, generic models of LAI_max were developed for the 30 studied sites. Dominant height was found to be the best predictor in those generic models. As expected, they showed a lower predictive performance than species-specific ones.     

What rights and benefits? The implementation of participatory forest management in Kenya: The case of Eastern Mau Forest Reserve

The study espoused the access analytical framework to investigate how introduction of Participatory Forest Management (PFM) in Kenya has changed the various actors’ ability to benefit from the forest resources of Eastern Mau Forest Reserve. Data collected through key informant interviews, and a household survey showed that implementation of PFM has triggered new income opportunities for forest adjacent communities in seedling production and beekeeping. However, PFM bestowed no real decision-making powers to the established Community Forest Associations (CFAs) over important forest resources such as timber and firewood. Members of the local communities and other actors have continued to access these resources through various structural and relational means, in the same way as before the introduction of PFM. Further, it is documented that PFM has introduced additional burdens on the local communities, especially the poorest households, as a result of increased enforcement of rules. Based on these findings, it is suggested that the PFM policy in Kenya, in its current form, is unlikely to realize its dual objectives of forest conservation and livelihood enhancement. To attain them would require a further devolution of rights to the CFAs.     

Fatty acid influence on Prochilodus lineatus (Characiformes,Prochilodontidae) embryo cryopreservation parameters.

This study aimed to evaluate the vitellogenic transference and incorporation of long‐chain polyunsaturated fatty acids (LC‐PUFA) into the membranes of Prochilodus lineatus embryos, aiming to increase the permeability to cryoprotectants and resistance to electric fields. One hundred thirty broodstock of P. lineatus were fed with control (C) or fish oil‐supplemented diets (FO) for 12 months. The fatty acid (FA) profle was determined using gas chromatography. For the neutral fraction, the FO group had a decrease in monounsaturated fatty acids (MUFA) and an increase in n3PUFA and, n6PUFA. To test for cryoprotectant toxicity, embryos were exposed for 20 min to a cryoprotectant solution of 1,2‐Propanediol (Prop) at a concentration of 5 or 6 molar (M). For FO, a reduction in survival of 33.1% was observed in 5 M, and no survival was observed at 6 M. Embryo samples were exposed the six polarized electric fields (3.4–51.6 joules), and with 11.2 J of energy, the control group exhibited reduced survival in 98.3% of the fish, whereas the FO presented superior resistance, exhibiting a survival similar to that of the OJ up to 40.2 J. We conclude that FA were transferred between P. lineatus broodstock to the embryos, with an increase in LC‐PUFA resulting in lower survival rates in the cryoprotectant test in the FO group and a greater physical plasticity of FO embryos to electrical field tests.     

Heavy metals in horse blood, serum, and feed in Minas Gerais, Brazil

Pollution is a subject of worldwide concern and discussion and various areas of science are seeking to integrate their knowledge in an attempt to improve understanding of the harmful effects of modern human activities. Thus, the objective of the current study was to assess the potential for using the horse as a bio-indicator of environmental pollution. Blood and serum samples from 120 horses from locations with different degrees of urbanization and industrialization and the feeds used for these animals were analyzed to determine their heavy metal (Cd, Pb, Ni, Cu, and Zn) content. The data obtained were compared. The results did not show increases in heavy metal concentration in the blood and serum of the horses with the intensification of urbanization and industrialization around the farms. Only Cd, as determined in the blood of the animals, showed a certain potential for using horses as bio-indicators of environmental pollution. The data for sex, age, and chemical composition of the foodstuffs supplied to the animals were not determinants in explaining the variation in the concentrations of heavy metals observed.     

Lymphosarcoma in an Eastern king snake and a rhinoceros viper

An antemortem diagnosis of lymphosarcoma was made in a captive Eastern king snake and a rhinoceros viper. The Eastern king snake died on the 1st day after biopsy of a liver nodule, and necropsy revealed multiple tumor nodules throughout all major organ systems. The rhinoceros viper died after chemotherapy with cytosine arabinoside. The major gross lesion was a large paracolonic coelomic tumor that extended into the adjacent musculature and subcutaneous tissue of the lateral abdominal wall. The immediate cause of death of the rhinoceros viper was believed to be severe renal tubular necrosis.     

The carotenoid pigments of the date

The carotenoid pigments of the date (Phoenix dactylifera) were investigated in 2 soft cultivars, ‘Hayany’ and ‘Barhee’, and in the semi-dry ‘Deglet Noor’. The total carotenoid content in the ripe fruit was 10–12 μg/g fresh weight. The carotenoid pattern in all investigated fruits was that of the chloroplast type, with only slight differences between the cultivars. Changes in the carotenoid pattern during ripening were followed in ‘Hayany’ and ‘Deglet Noor’. The total carotenoid content decreased drastically from 36.3 to 21.2 μg/g dry weight in the soft dates, and from 23.2 to 12.0 μg/g dry weight in the semi-dry cultivar. The carotenoid degradation may be due primarily to the loss of moisture during maturation, and is probably unrelated to the gradual darkening of the ripening fruit. The pattern of the retained carotenoids remained essentially similar.The vitamin A values of the 3 cultivars, expressed as retinol equivalents, were calculated.     

Fluorescent Stain Method for the Simultaneous Determination of Mitochondrial Potential and Integrity of Plasma and Acrosomal Membranes in Boar Sperm

The purpose of this study was to validate a technique for simultaneous evaluation of the plasma, acrosomal and mitochondrial membranes in boar spermatozoa, using an association of fluorescent probes: Propidium iodide (PI), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and JC-1. Three ejaculates from each of four different boars, all showing motility >or=80% and abnormal morphology 相似文献   

Practical Techniques for Bovine Sperm Simultaneous Fluorimetric Assessment of Plasma, Acrosomal and Mitochondrial Membranes

This experiment was performed to develop and validate practical techniques for simultaneous evaluation of the integrity of plasma and acrosomal membranes, as well as mitochondrial function in bovine spermatozoa using associations of fluorescent probes. Four protocols of fluorescent probes association were defined: protocol 1: propidium iodide (PI), fluorescein isothiocyanate‐conjugated Pisum sativum agglutinin (FITC‐PSA) and rhodamine 123; protocol 2: PI, FITC‐PSA and MitoTracker Green FM (MITO); protocol 3: PI, Hoechst 33342 (H342), FITC‐PSA and CMXRos; and protocol 4: PI, H342, FITC‐PSA and JC‐1. Three ejaculates from each of the four bulls (n = 12) were utilized, showing sperm motility ≥80% and abnormal morphology ≤10%. The semen was diluted in Modified Tyrode’s medium (TALP) (25 × 10⁶ spermatozoa/ml) and split into two aliquots, one sample was flash‐frozen in liquid nitrogen and thawed. Samples for three treatments were prepared with the following ratio of fresh semen : flash‐frozen semen: 100 : 0, 50 : 50 and 0 : 100. Samples were stained in all four protocols and evaluated by epifluorescence microscopy. Protocol 1 did not result in a satisfactory stain, so it could not be validated. Protocols 2, 3 and 4 were validated and showed high determination coefficient to plasma membrane integrity (R² = 0.95, 0.93 and 0.92, respectively), acrosome integrity (R² = 0.95, 0.92 and 0.91, respectively) and mitochondrial function (R² = 0.84, 0.93 and R² = 0.93, respectively). These techniques are efficient for the simultaneous integrity evaluation of plasma and acrosomal membranes and mitochondrial function in bovine spermatozoa. However, JC‐1 has an advantage over MITO and CMXRos, as it separates two cell populations with high and low mitochondrial membrane potential.