Study of the Water Solubility and Sorption on Particulate Matters of Phthalate in the Presence of Humic Acid Using 14C Labelled Di-(2-Ethylhexyl)Phthalate

Phthalate esters have become widespread contaminants in the aquatic environment, because of their extensive use as non-reactive plasticizers. There is, however, little accurate data on their solubility, transportation, and distribution in the aquatic environment. In this work, we have investigated the influence of humic acid on the water solubility of di-(2-ethylhexyl)phthalate (DEHP), one of the most frequently used phthalate esters in the laboratory studies for DEHP. We have also studied the solid–water distribution of DEHP in the presence of humic acid and particulate matter (activated carbon, ferrihydrite, and kaolinite) to simulate their distribution in a natural aquifer (ternary system). The results show that the water solubility of DEHP can be significantly increased by humic acid. The shape K _eq value, the binding constant of DEHP between water and humic acid at equilibrium, was obtained by fitting experimental data for each humic acid. The shape K _eq values in the ternary system apparently decreased in the order of ferrihydrite ≤ kaolinite ≈ octanol/water partition activated carbon systems. This result shows that the increase in the hydrophobicity of HA remaining in the solution will lead to the apparent increase of shape K _eq in the system since more hydrophilic solid sorbs relatively more hydrophilic HA molecule. The solid–water partition coefficient (shape K _W-P ) for DEHP in the environment estimated from this study is consistent with those reported based on the experiments for natural samples. Quantitative values obtained in this study, such as K'_ow, shape K _eq, and shape K _W-P , can be useful for estimating the behavior of DEHP.     

An application of the mixed linear model and the dirichlet process prior in veterinary medicine research

This article applies Bayesian nonparametric techniques of analysis to the mixed linear model. The distribution of the random effects is specific as a nonparametric prior. A Dirichlet process prior is specified on the space of prior distributions. A modified Dirichlet process is described and applied using a Gibbs sampler. The approach is demonstrated in an investigation of the changes over time of packed cell volume in two breeds of cattle.     

Nitrogen and carbon mineralization of semi-arid shrubland soil exposed to long-term atmospheric nitrogen deposition

Anthropogenic N-deposition represents a significant input of N into semi-arid chaparral and coastal sage scrub (CSS) shrublands of southern California. High levels of atmospheric N deposition have the potential to increase soil C and N mineralization, and we hypothesize that semi-arid shrubland soil exposed to long-term (decades) high N deposition will have significantly higher C and N mineralization potentials. This hypothesis was tested in a laboratory incubation where the inorganic N (NH₄+NO₃) and CO₂ production of soils maintained at a constant temperature of 25°C and a soil moisture of 0.25 g H₂O/g (65% water-filled pore space) were sampled sequentially over a 50-week period. The temporal trend in cumulative C and N mineralization was well described by a first- and zero-order model, respectively. Long-term atmospheric N deposition significantly increased potential N mineralization but not C mineralization, and both the rate and total N mineralization were significantly positively correlated with the surface (0–10 cm) soil δ ¹⁵N natural abundance and negatively correlated with the surface soil C:N ratio. While the incubation techniques used here do not provide realistic estimates of in situ C or N mineralization, these assays indicate that atmospheric N deposition has significantly altered ecosystem N storage and cycling.     

Micropropagation of <Emphasis Type="Italic">Salvadora</Emphasis><Emphasis Type="Italic">persica</Emphasis>-a tree of arid horticulture and forestry

A micropropagation method for Jaal (Salvadora persica)—a tree of arid horticulture and forestry has been developed. Nodal segments of fresh shoot sprouts originated from axillary buds obtained from a plant around 35–40 years old lopped plant were used as explants for establishment of in vitro cultures. Surface-sterilized explants produced optimum number of shoots through activation of axillary buds on Murashige and Skoog’s (MS) medium containing 8.88 μM BA (6-benzyladenine) + additives (25 mgl⁻¹ each of adenine sulphate, arginine, citric acid, 50 mgl⁻¹ ascorbic acid). The shoot multiplication was influenced by the successive transfer of the mother explants for 4–5 passages. The maximum number (23.1 ± 0.73 shoots per explant) of shoots were regenerated on MS supplemented with 1.11 μM BA + 1.16 μM Kn (Kinetin) + 0.54 μM NAA (α-naphthalene acetic acid). About 90% shoots pulse-treated with a combination of 2460.27 μM Indole-3-butyric acid (IBA) + 494.56 μM NOA (2-naphthoxy acetic acid) were rooted ex vitro on soilrite within 15–18 days. Over 80% cloned plantlets were hardened successfully in a green house and transferred to polybag/pots.     

Longitudinal growth strain as a log and wood quality predictor for plantation-grown <Emphasis Type="Italic">Eucalyptus nitens</Emphasis> sawlogs

Peripheral longitudinal growth strain (LGS) was measured on a total of 81, 22-year-old pruned Eucalyptus nitens trees from five thinning treatments in a plantation thinning trial in Tasmania. Growth strain data were gathered at breast height on each tree using the CIRAD-Forêt method. The effects of thinning treatment and tree diameter on LGS and its relationships to solid-wood traits determined in a processing trial were examined. LGS was significantly higher in the direction of the prevailing wind and was not significantly affected by either thinning treatment or tree diameter. An index of log end splitting was positively related to tree diameter, sawlog position (upper/lower), and LGS, which explained up to an additional 20% of the variance after tree diameter and log position were accounted for in a linear regression model. High LGS and log end splitting were significant indicators of increased board end splitting.     

Soil biological properties under different tree based traditional agroforestry systems in a semi-arid region of Rajasthan,India

An investigation was carried out in an Entisol at farmers’ field in Jaipur district, Rajasthan, India during 2002–2004 to evaluate the effect of traditionally grown trees on soil biological characteristics. Traditionally grown trees in farm lands for study consisted of Prosopis cineraria (L.), Dalbergia sissoo (Roxb.) ex DC, Acacia leucophloea (Roxb.) and Acacia nilotica (L.) Del. having a canopy diameter of 8 m. Results revealed significant and substantial improvement in soil biological activity in terms of microbial biomass C, N and P, dehydrogenase and alkaline phosphatase activity under different tree based agroforestry systems as compared to a no tree control (cropping alone). Soil microbial biomass C, N and P under agroforestry varied between 262–320, 32.1–42.4 and 11.6–15.6 μg g⁻¹ soil, respectively, with corresponding microbial biomass C, N and P of 186, 23.2 and 8.4 μg g⁻¹ soil under a no tree control. Fluxes of C, N and P through microbial biomass were also significantly higher in P. cineraria based land use system followed by D. sissoo, A. leucophloea and Acacia nilotica in comparison to a no tree control. Thus, it is concluded that agroforestry system at farmers’ field enhance soil biological activity and amongst trees, P. cineraria based system brought maximum and significant improvement in soil biological activity.     

Comparative analysis of a wood: adhesive bondline

The wood–adhesive interface was analyzed using five methods with the objective of quantitatively assessing penetration of adhesive into the porous wood network. Methods included fluorescence microscopy, scanning electron microscopy, backscatter electron imaging, wavelength dispersive spectroscopy, and X-ray microtomography (XMT). Each method provided a visual inspection, and all of the analysis methods were applied to the same field of view. XMT was the primary technique of interest. Rubidium hydroxide was used in place of sodium hydroxide in the formulation of phenol–formaldehyde adhesive. Rubidium was found to increase the X-ray attenuation of the adhesive. However, rubidium migrated beyond the adhesive interphase during specimen preparation, thus reducing its effectiveness for image contrast enhancement. The wood species studied included red oak (Quercus rubra), Douglas-fir (Pseudotsuga menziesii), and hybrid poplar (Populus deltoides × Populus trichocarpa). All techniques used for this study were useful, but each presented some limitations for bondline analysis. Despite the problem with rubidium migration, XMT for this application was promising.     

Defining the poor by the rural communities of Burkina Faso: implications for the development of sustainable parkland management

Parklands are mixtures of trees and shrubs that farmers select for certain functions. In the Sahel, parklands are cultivated together with staple food crops, such as millet and sorghum. Parkland trees are sources of foods, including fruits, fats, oils, leafy vegetables, nuts and condiments that complement food crops in the local diet. Despite their socio-economic and ecological role, many studies have shown that the parklands are degrading very rapidly. Therefore, there is a need to undertake restoration actions that are based on a clear understanding of the livelihood context, such as the wealth status of the farmers, in which these agroecosystems are evolving. Thus, we conducted a wealth survey with rural communities in two different farming systems of Burkina Faso that are the cereal-based system in the “Plateau Central” and the cotton-based system in the “Boucle du Mouhoun”. A total of twelve villages were sampled, six villages for each system. The Participatory Analysis of Poverty and Livelihood Dynamics (PAPoLD) method was used by rural farmers to rank farmer households of their communities according to their wealth status. The results revealed that 70% of households in the Plateau Central and 56% in the “Boucle du Mouhoun” managed to escape poverty, and became wealthy. However, 2% of households of the villages in the Plateau Central and 6% in “Boucle du Mouhoun” fell into poverty in the same period whereas 9 and 12% remained poor in these zones, respectively. The main causes associated with households getting out of poverty are subsidies for cotton, external revenues from relatives working in towns and gardening activities. Death of spouse, illness, high number of people in the household and indebtedness are the main causes that lead into poverty. The implications of these findings in designing appropriate policies and management options for a sustainable management of agroforestry parklands under different land use systems were finally discussed.     

Effects of gibberellin A<Subscript>4/7</Subscript>, 6-benzylaminopurine and chlormequat chloride on the number of male and female strobili and immature cones in Chinese pine (<Emphasis Type="Italic">Pinus tabuliformis</Emphasis>) with foliar sprays

Three kinds of plant growth regulators, gibberellinA 4/7 (GA 4/7 ), 6-benzylaminopurine (BA), and chlormequat chloride (CCC), were evaluated for their ability to promote strobilus and cone production in a Chinese pine (Pinus tabuliformis Carr.) clonal seed orchard. Treatments (0, 250, 500, or 1000 mg L -1 ) were applied during three periods (June- July, July-August and August-September) in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed...