Movement of metolachlor in soil: effect of new organo-clay formulations

The use of commercially available formulations of metolachlor has resulted in its leaching and migration to water sources. Formulations of metolachlor designed to reduce its leaching in soil have been prepared by adding the herbicide dissolved in an organic solvent or in water to organo-clay complexes. Best formulations were made when the organo-clay complex was formed by adsorbing the monovalent organic cations benzyltrimethylammonium (BTMA) or benzyltriethylammonium (BTEA) onto sodium montmorillonite (Mont) at 0.5 or 0.8 mole kg⁻¹ clay. Adsorption of metolachlor to organo-clays followed the sequence Mont-BTMA 0.5 > Mont-BTMA 0.8 > Mont-BTEA 0.8 > Mont-BTEA 0.5 > Mont. Fourier transform infrared (FTIR) analysis demonstrated the occurrence of shifts of several peaks of adsorbed metolachlor relative to the free herbicide, indicating the existence of strong interactions between metolachlor molecules and the organo-clay surface. Leaching studies employing organo-clay and commercial formulations were carried out under greenhouse and field conditions. Metolachlor applied as organo-clay formulations leached less than the commercial formulation. Organo-clay formulations prepared by adding the herbicide as a water solution showed less leaching in the soil profile than those made by using organic solvent. Under greenhouse conditions, the herbicidal activity of organo-clay formulations was similar to that of the commercial one. Under field conditions, leaching from Mont-BTMA 0.5-metolachlor was less than that from the commercial formulation, demonstrating the environmental and agricultural advantages of the organo-clay formulations of metolachlor. © 1999 Society of Chemical Industry     

The economic value of old growth trees in Israel

We estimated the annual value of old growth trees in Israel using a Contingent Valuation (CV) study. We used the payment card (PC) procedure and surveyed both forest visitors as well as a representative sample of the general population. It was found out that the annual value can range between 2.35 and 19.9 million Euros depending on the assumption with respect to who are the beneficiaries of the project. This value is important since old growth trees are used less for active recreation but has an important role in the heritage of the country. As such they should be allocated funds to be preserved. This paper tries to understand the value of this commodity from an economic point of view in order to conclude if it deserves the financial effort needed to be preserved.     

Water use by Tabor and Kermes oaks growing in their respective habitats in the Lower Galilee region of Israel

We estimated water use by the two main oak species of the Lower Galilee region of Israel—Tabor (Quercus ithaburensis) and Kermes (Quercus calliprinos)—to develop management options for climate-change scenarios. The trees were studied in their typical phytosociological associations on different bedrock formations at two sites with the same climatic conditions. Using the heat-pulse method, sap flow velocity was measured in eight trunks (trees) of each species during a number of periods in 2001, 2002 and 2003. Hourly sap flux was integrated to daily transpiration per tree and up-scaled to transpiration at the forest canopy level. The annual courses of daytime transpiration rate were estimated using fitted functions, and annual totals were calculated. Sap flow velocity was higher in Tabor than in Kermes oak, and it was highest in the youngest xylem, declining with depth into the older xylem. Average daytime transpiration rate was 67.9 ± 4.9 l tree⁻¹ d⁻¹, or 0.95 ± 0.07 mm d⁻¹, for Tabor oak, and 22.0 ± 1.7 l tree⁻¹d⁻¹, or 0.73 ± 0.05 mm d⁻¹, for Kermes oak. Differences between the two oak species in their forest canopy transpiration rates occurred mainly between the end of April and the beginning of October. Annual daytime transpiration was estimated to be 244 mm year⁻¹ for Tabor oak and 213 mm year⁻¹ for Kermes oak. Adding nocturnal water fluxes, estimated to be 20% of the daytime transpiration, resulted in total annual transpiration of 293 and 256 mm year⁻¹ by Tabor and Kermes oaks, respectively. These amounts constituted 51% and 44%, respectively, of the 578 mm year⁻¹ average annual rainfall in the region. The two species differed in their root morphology. Tabor oak roots did not penetrate the bedrock but were concentrated along the soil–rock interface within soil pockets. In contrast, the root system of Kermes oak grew deeper via fissures and crevices in the bedrock system and achieved direct contact with the deeper bedrock layers. Despite differences between the two sites in soil–bedrock lithological properties, and differences in the woody structure, annual water use by the two forest types was fairly similar. Because stocking density of the Tabor oak forests is strongly related to bedrock characteristics, thinning as a management tool will not change partitioning of the rainfall between different soil pockets, and hence soil water availability to the trees. In contrast, thinning of Kermes oak forests is expected to raise water availability to the remaining trees.     

Detection of blood‐brain barrier dysfunction using advanced imaging methods to predict seizures in dogs with meningoencephalitis of unknown origin

BackgroundThe blood‐brain barrier (BBB), which separates the intravascular and neuropil compartments, characterizes the vascular bed of the brain and is essential for its proper function. Recent advances in imaging techniques have driven the development of methods for quantitative assessment of BBB permeability.Hypothesis/ObjectivesPermeability of the BBB can be assessed quantitatively in dogs with meningoencephalitis of unknown origin (MUO) and its status is associated with the occurrence of seizures.AnimalsForty dogs with MUO and 12 dogs without MUO.MethodsRetrospective, prospective cohort study. Both dynamic contrast enhancement (DCE) and subtraction enhancement analysis (SEA) methods were used to evaluate of BBB permeability in affected (DCE, n = 8; SEA, n = 32) and control dogs (DCE, n = 6; SEA, n = 6). Association between BBB dysfunction (BBBD) score and clinical characteristics was examined. In brain regions where BBBD was identified by DCE or SEA magnetic resonance imaging (MRI) analysis, immunofluorescent staining for albumin, glial fibrillary acidic protein, ionized calcium binding adaptor molecule, and phosphorylated mothers against decapentaplegic homolog 2 were performed to detect albumin extravasation, reactive astrocytes, activated microglia, and transforming growth factor beta signaling, respectively.ResultsDogs with BBBD had significantly higher seizure prevalence (72% vs 19%; P = .01) when compared to MUO dogs with no BBBD. The addition of SEA to routine MRI evaluation increased the identification rate of brain pathology in dogs with MUO from 50% to 72%.Conclusions and Clinical ImportanceImaging‐based assessment of BBB integrity has the potential to predict risk of seizures in dogs with MUO.     

Roasted pigs and bao dumplings: Festive food and imagined transnational identity in Chinese–Vietnamese festivals

Abstract: This article explores the ways by which special dishes prepared for the Chinese community festivals in the Vietnamese town of Hoi An negotiate and expand the notions of ethnic identity and place of origin of migrant groups. Although the festivals stress specific regional identities in (Imperial) China, the food consumed in the communal feasts defines much wider scopes of ethnicity and territory. By discussing these alternative scopes and comparing the feasts in two festivals, the article suggests that a new transnational ‘greater‐Chinese’ identity is celebrated in contemporary Chinese‐Vietnamese community festivals. The scope and importance of this new identity is analysed in relation to an imagined ‘greater‐China’ as a dominant player in the forthcoming ‘Pacific Century’. The position of the culinary sphere as a privileged arena for sociocultural negotiation, especially in post‐socialist authoritarian regimes, is also discussed.     

Dynamics of replication-independent histone turnover in budding yeast

Chromatin plays roles in processes governed by different time scales. To assay the dynamic behavior of chromatin in living cells, we used genomic tiling arrays to measure histone H3 turnover in G1-arrested Saccharomyces cerevisiae at single-nucleosome resolution over 4% of the genome, and at lower (approximately 265 base pair) resolution over the entire genome. We find that nucleosomes at promoters are replaced more rapidly than at coding regions and that replacement rates over coding regions correlate with polymerase density. In addition, rapid histone turnover is found at known chromatin boundary elements. These results suggest that rapid histone turnover serves to functionally separate chromatin domains and prevent spread of histone states.     

Metabolic and behavioral adaptation of light-bodied chicks to meal feeding.

1. Two-week-old male chicks of a light-bodied strain were fed one (1M) or two (2M) 2-h meals per day. An additional group was pair-fed (P1M) the amount consumed by the 1M group on the previous day. 2. After 21 days, final body weight of the 1M and 2M chicks attained 65% and 80%, respectively, of that of the control group fed ad libitum. The weight gain of the P1M chicks was equal to that of the 1M chicks. 3. Food consumption of chicks adapted to meals was not even throughout the feeding period. On day 16 of the experiment, the 1M birds consumed 65% of the meal during the first 30 min. P1M chicks behaved similarly to the 1M ones. The intake of the 2M chicks during each meal was exactly half of their daily consumption, despite the uneven time period between meals. 4. The time during which food remained in the gastrointestinal tract (GIT) was longer under the meal feeding regimes than in the ad libitum-fed groups. 5. Although neither body composition nor metabolisable energy was affected by meal regime, food utilisation was poorer in the 1M and P1M than in the ad libitum and 2M-fed chicks.     

Efect of intermittent feeding on blood plasma growth hormone and prolactin in chickens of a heavy breed

1. Variations in plasma growth hormone (GH) and prolactin concentrations were determined during growth (at 20, 33, 56 and 83 d of age) in ad libitum (control) and intermittently (alternate days) fed chicks.

2. In each group of birds the concentration of plasma GH was inversely related to age. The mean prolactin concentration was highest in the youngest (20‐d‐old) birds.

3. The concentration of plasma GH in the intermittently‐fed birds deprived of food for 24 h (depleted birds) was significantly higher than that in the controls at 33, 56 and 83 d of age. The mean GH concentration in the intermittently‐fed birds 24 h after refeeding (repleted birds) was less than that in the depleted ones.

4. The overall mean concentration of plasma prolactin in the depleted birds was significantly less than that in the control and repleted birds.

5. These results are consistent with the effects of fasting on GH and prolactin secretion and demonstrate that growth retardation in the intermittently‐fed birds was not due to impaired GH secretion.     

Compensatory growth and sexual maturity in broiler females reared under severe food restriction from day of hatching

1. Compensatory growth and the onset of lay were studied in White Rock broiler females severely restricted in food intake from day of hatching.

2. When changed to feeding ad libitum the restricted birds gained weight rapidly, but stabilised at a mean body weight 500 to 700 g less than that of controls fed ad libitum. Egg production was similar to that of controls.

3. Birds maintained at low mean body weight (2 224 g at 42 weeks) by continued restriction did not come into lay. In groups maintained at somewhat higher mean body weights (2 300 to 2 700 g) for periods of up to a year, some birds came into lay.

4. Birds fed ad libitum showed accelerated development of comb, ovary and oviduct and weighed 2 300 to 2 700 g between 14 and 15 weeks of age, but did not come into lay until 20.5 weeks of age.

5. These results suggest that a minimum body weight and age may be required for the onset of lay in this strain.