Phenology modelling of major insect pests in fruit orchards from biological basics to decision support: the forecasting tool SOPRA*

The forecasting tool SOPRA has been developed with the objective of optimizing timing of monitoring, management and control measures of insect pests in fruit orchards in Switzerland. Applying time‐varying distributed delay approaches, phenology‐models were developed driven by solar radiation, air temperature and soil temperature on hourly basis. Relationships between temperature and stage‐specific development rates for relevant stages of the life cycles were established under controlled laboratory conditions for Dysaphis plantaginea, Hoplocampa testudinea, Cydia pomonella, Grapholita lobarzewskii, Cacopsylla pyri, Rhagoletis cerasi, Anthonomus pomorum and Adoxophyes orana. The implementation of body temperatures in the models is based on habitat selection and biophysical modelling of habitat conditions. In order to validate modelling, phenology predictions were compared with several years of independent field observations. On the basis of local weather data, the age structure of the pest populations is simulated and crucial events for management activities are announced. Through a web interface, the simulation results are made available to consultants and growers ( http://www.sopra.info ) and the latter can be applied as a decision support system for the eight major insect pests of fruit orchards in the alpine valleys and north of the Alps on local and regional scale.     

Determination of flavonol metabolites in plasma and tissues of rats by HPLC-radiocounting and tandem mass spectrometry following oral ingestion of [2-(14)C]quercetin-4'-glucoside

Epidemiological studies suggest that consumption of flavonol-rich diets decreases the risk of developing heart disease and certain cancers. Recent studies have detected flavonol conjugates in blood and urine following various dietary interventions. To assess to what extent flavonols also accumulate in tissues, where they might be expected to exert anti-carcinogenic and anti-atherogenic effects, [2-(14)C]quercetin-4'-glucoside was synthesized and fed to rats. After 60 min, 93.6% of the ingested radioactivity was recovered from the intestine, incorporated into 18 metabolites that had undergone deglycosylation followed by varying degrees of glucuronidation, methylation, and/or sulfation. [(14)C]Quercetin, the aglycon of the radiolabeled substrate, was present in the intestine and in trace amounts in the liver but was not detected in the plasma and kidneys. The original [2-(14)C]quercetin-4'-glucoside was detected exclusively in the intestine, where it accounted for only 26.2% of the radioactivity. The remainder of the recovered radioactivity was located mainly in the plasma, liver, and kidneys as (14)C-labeled metabolites. However, compared to the quantities in the gastrointestinal tract, the levels of metabolites in plasma and body tissues were very low, indicating only limited absorption into the blood stream. The data demonstrate that quercetin-4'-glucoside, which is a major flavonol in onions, undergoes rapid and extensive metabolism in the intestine, and this appears not to be associated to any extent with transport across the gut wall into the blood stream.     

Solution chemistry in acid forest soils: Are the BC : Al ratios as critical as expected in Switzerland?

The molar ratio of base nutrient cations to total dissolved aluminum (BC : Al_tot) in the soil solution was measured at six forest sites in Switzerland in acid mineral soils to determine whether the ratio measured in the field was lower than the critical value of 1, as predicted by the mapping of exceedances of critical loads of acidity. The soil chemistry was then related to the soil solution composition to characterize the typical effective base saturation (BS) and BC : Al ratio in soil leading to critical BC : Al_tot in the soil solution. The median BC : Al_tot ratio in the soil solution never reached the critical value in the root zone at any sites for the whole observation period (1999–2002), suggesting that the BC : Al_tot ratios measured in the field might be higher than those modeled for the determination of critical loads of acidity. The gibbsite model usually applied for the calculation of critical loads was a poor predictor of the Al³⁺ activity at the study sites. A curvilinear pH‐pAl³⁺ relationship was found over the whole range of pH (3.8–6.5). Above a pH of 5.5, the slope of the pH‐pAl³⁺ relation was close to 3, suggesting equilibrium with Al(OH)₃. It decreased to values smaller than 1.3 below a pH of 5.5, indicating complexation reactions with soil organic matter. The BS and the BC : Al ratios in the soils were significantly correlated to the BC : Al_tot ratios in the soil solution. The soil solutions with the lowest BC : Al_tot ratios (≤ 2) were typically found in mineral soils with a BS below 10 % and a BC : Al ratio in the soil lower than 0.2. In acid pseudogleyed horizons overlying a calcareous substrate, the soil solution chemistry was strongly influenced by the composition of the underlying soil layers. The soil solutions at 80 cm had pH values and BC : Al_tot ratios much higher than expected. This situation should be taken into account for the calculations of critical loads of acidity.     

Does exceeding the critical loads for nitrogen alter nitrate leaching,the nutrient status of trees and their crown condition at Swiss Long-term Forest Ecosystem Research (LWF) sites?

Nitrogen (N) deposition exceeds the critical loads for this element in most parts of Switzerland apart from the Alps. At 17 sites (8 broadleaved stands, 8 coniferous stands, and 1 mixed stand) of the Swiss Long-term Forest Ecosystem Research network, we are investigating whether N deposition is associated with the N status of the forest ecosystems. N deposition, assessed from throughfall measurements, was related to the following indicators: (1) nitrate leaching below the rooting zone (measured on a subset of 9 sites); (2) the N nutrition of the forest stand based on foliar analyses (16 sites); and (3) crown defoliation, a non specific indicator of tree vitality (all 17 sites). Nitrate leaching ranging from about 2 to 16 kg N ha⁻¹ a⁻¹ was observed at sites subjected to moderate to high total N deposition (>10 kg ha⁻¹ a⁻¹). The C/N ratio of the soil organic layer, or, when it was not present, of the upper 5 cm of the mineral soil, together with the pool of organic carbon in the soil, played a critical role, as previous studies have also found. In addition, the humus type may need to be considered as well. For instance, little nitrate leaching (<2 kg N ha⁻¹ a⁻¹) was recorded at the Novaggio site, which is subjected to high total N deposition (>30 kg ha⁻¹ a⁻¹) but characterized by a C/N ratio of 24, large organic C stocks, and a moder humus type. Foliar N concentrations correlated with N deposition in both broadleaved and coniferous stands. In half of the coniferous stands, foliar N concentrations were in the deficiency range. Crown defoliation tended to be negatively correlated with N concentrations in the needles. In the majority of the broadleaved stands, foliar N concentrations were in the optimum nutritional range or, on one beech plot with high total N deposition (>25 kg ha⁻¹ a⁻¹), above the optimum values. There was no correlation between the crown defoliation of broadleaved trees and foliar concentrations.     

Fijian teachers on the move: Causes,implications and policies

Abstract: Education has increasingly come to be seen as a potent development tool, not least because the quality of the education system today affects a country's development for decades to come. The migration of teachers – both internationally by way of emigration and internally within countries – may adversely affect the quality of education especially in a country like Fiji with a limited human resource capacity. The emigration of workers, particularly of highly skilled workers who are endowed with high levels of human capital, has severe implications for a small country like Fiji. The emigration of teachers who are the largest professional group of migrants has led to the filling of vacancies by less experienced and junior teachers and is widely believed to have led to falling educational standards. In addition to international migration, there is substantial internal migration of teachers, mostly away from remote schools to urban areas. Rural schools find it particularly difficult to recruit and keep qualified and experienced personnel. In the process, rural areas have been drained of some of their best human resources. This article provides an overview of the scale of migration of secondary teachers from Fiji, raises development issues connected to the international and internal migration of teachers, describes policy responses that this migration has elicited and identifies areas requiring further research with a view to making policy recommendations as well as contributing to the literature on skilled migration in the Pacific.     

Discovery of an unmelted h-chondrite inclusion in an iron meteorite

The link between H chondrites and silicate inclusions in group IIE iron meteorites has long been suspected, but direct evidence for a common parentage has remained elusive. The discovery of an unmelted chondritic inclusion in the Techado iron meteorite sheds light on the genetic relation between these two groups, providing clues on the origin of chondritic materials as inclusions in iron meteorites. It is proposed that the complex IIE iron meteorite breccias formed by collisions with several different bodies, followed by deep burial of metal and silicate fragments in the asteroidal megaregolith.     

Leukoencephalomalacia and laminar neuronal necrosis following smoke inhalation in a dog

Acute respiratory and neurologic disease after smoke inhalation are well documented, but human patients may also develop delayed-onset neurologic symptoms associated with leukoencephalomalacia after exposure to smoke or carbon monoxide. In this case, a dog developed progressive neurologic signs 6 days after rescue from an apartment fire. At necropsy 9 days after smoke inhalation, leukoencephalomalacia of the central cerebral white matter was accompanied by laminar necrosis of cerebrocortical neurons. This is the first report of delayed posthypoxic leukoencephalopathy in a nonhuman animal.     

Trapped solar wind noble gases, kr81/kr exposure ages and k/ar ages in apollo 11 lunar material

Grain size and etching experiments show that the fine lunar material contains large amounts of trapped solar wind particles. Elemental and isotopic compositions of the noble gases in solar material and in the terrestrial atmosphere are significantly different, except for the Ar(36)/ Ar(38) and the Kr isotope ratios. Exposure ages of two rocks and of the fine material are between 380 and 510 x 10(6) years. Feldspar concentrates give K/Ar ages of 3220 and 3300 x 10(6) years, significantly higher than the unseparated rock.     

Influence of Soluble and Slow-Release Fertilizers on Vegetative Growth of Containerized Citrus Nursery Trees

The production system for certified citrus nursery trees in São Paulo State, Brazil, stipulates the use of screenhouses, rigorous selection of rootstocks, and the production of budwood under high standards in order to prevent diseases such as sudden death, Citrus Var, and foot rot (Phytophthora spp.). The establishment of adequate nutritional levels for citrus nursery trees also leads to higher production efficiency in this system. This work was divided into two trials. The first evaluated the influence of certain concentrations and formulas of slow-release fertilizer on the growth of ‘Pera’ sweet orange (Citrus sinensis L. Osbeck) budded on ‘Rangpur’ lime (Citrus limonia Osbeck) on two substrates. The development of ‘Rangpur’ lime liners was not influenced by composition of the substrate, nor by the concentrations or formulas of slow-release fertilizers. Substrate composition and formulas, or concentrations of fertilizers also did not affect budded tree growth, except that the greatest root fresh and dry matter were found in plants cultivated with lower concentrations. The second trial evaluated the influence of different soluble and slow-release fertilizers on growth of ‘Valencia’ sweet orange (Citrus sinensis L. Osbeck) nursery trees budded on ‘Rangpur’ lime. Scion length, stem diameter, scion fresh and dry matter, and leaf area were not affected by fertilizer sources. Fertigation induced the greatest development of roots (fresh and dry matter) when limestone was added.