Modeling the impacts of agroforestry systems on the spatial patterns of soil erosion risk in three catchments of Claveria, the Philippines

Agroforestry is one of the preferred land-use options for smallholder farms in tropical landscapes due to its ability to increase land productivity and protect soil from erosion. We investigated the impacts of agroforestry and traditional monocropping systems on the spatial patterns of soil erosion risk in three catchment areas of Claveria, the Philippines, using WaTEM/SEDEM, a spatially distributed soil erosion model. The model predicts soil loss in catchments based on the Revised Universal Soil Loss Equation (RUSLE) by taking into account the influences of rainfall, soil erodibility, vegetation cover and 2-dimensional variations in landscape structure. The predicted soil erosion rates were transformed into risk values in order to identify areas with higher risk for erosion. Model results indicate a large spatial variability in soil erosion risk patterns, with higher risks occurring on slopes greater than 8% on land under non-agroforestry use. The soil erosion risk maps were used to formulate site-specific agroforestry recommendations for future landscape amelioration plans.     

The effects of urban retail greenery on consumer experience: Reviewing the evidence from a restorative perspective

Over the last three decades solid empirical evidence for the positive influence of greenery on human psychological and cognitive functioning has been steadily accruing. Based on this evidence, researchers and practitioners increasingly realize the importance of urban greening as a strategic activity to promote human wellbeing. Although commercial and retail activities constitute a significant and influential component of urban contexts, a concern is that the stakeholders involved (e.g. merchants) can sometimes be reluctant to integrate vegetation in commercial districts. This can be an important stumbling block for the process of urban greening. In this paper we introduce the concept of Biophilic Store Design (BSD) as the retail design strategy to consciously tap the beneficial effects of vegetation. The central aim of this paper is to demonstrate that the reluctance of certain retail stakeholders to integrate greening practices like BSD is unjustified. Two lines of evidence in support of this claim will be discussed. On the one hand, we sketch a conceptual framework which supports the view that BSD can have restorative effects for those implied in store environments. On the other hand, we review Wolf's multi-study research program on the effects of urban greening on consumer behavior, attitudes, and perceptions. These two lines of evidence show that commercial activities and urban greening are not to be considered as antagonistic but as mutually reinforcing practices.     

Electron microscopic investigations on the cytology of Ustilago avenae as influenced by the systemic fungicides triadimefon,nuarimol, and imazalil-nitrate: A thin-section and freeze-fracture study

Investigations were undertaken on fungicide-treated and untreated sporidia of Ustilago avenae. Thin-section and freeze-fracture techniques were employed in order to show their intracellular structure. The fungicides triadimefon, nuarimol, and imazalil-nitrate were applied at 5 μg ml⁻¹ for 8 and 16 hr. Their fungicidal actions were expressed at the morphological level in form of inhibition of the budding process of the sporidia resulting in filamentous promycelium and at the ultrastructural level in the form of enlarged diameters of the cells, considerable thickening of peripheral cell walls and septa, and higher contrast together with progressing necrosis. Furthermore, an increased number of mitochondria was found in the fungicide-treated organism. As compared to the untreated controls, their organelles were enlarged and irregular in shape. Higher amounts of endoplasmic reticulum and new arrangements of the membranes to myelin-like structures were observed as well as an extensive vacuolization and accumulation of lipid bodies. The vacuoles were filled up with membrane-like aggregates and vesicles, which could be extruded by exocytosis. Specific structures on the plasmalemma of plasmatic and extraplasmatic fracture faces point to exocytosis. Moreover, hemispherical pits and protrusions, aggregation of intramembrane particles, and disappearance of the straight, fissure-like invaginations were observed. An extended incubation period (16 hr) with triadimefon and nuarimol resulted in the complete destruction of the cellular system of most sporida.     

Estimation of Daily Human Intake of Food Flavonoids

The daily intake of food flavonoids was determined using a semiquantitative food frequency questionnaire (FFQ) and a four day non consecutive food diary (4DFR) in a group of 45 female Flemish dietitians. The subjects were asked to report their food intake three times: day 1 using the FFQ (FFQ1); between day 2 and 13 using a four day non consecutive food diary (4DFR); and again the FFQ on day 14 (FFQ2). The total flavonoid intake in mg/day as estimated with the different methods were respectively (mean and SD) for FFQ1 166.0 +/- 146.6 mg/day; for 4DFR 203.0 +/- 243.2 mg/day; and for FFQ2 158.3 +/- 151.8 mg/day. There was a significant different estimate for the amount of flavan-3-ols, flavanones and flavones when comparing the two FFQs with the 4DFR. The two research methods classified 88% of the 45 dietitians in the same or in an adjacent quartile for total flavonoid intake. The findings of this study indicate that the developed FFQ seems to be a simple and reliable method to assign subjects in quartiles of flavonoid intake.     

TOTAL MERCURY AND METHYLMERCURY IN SEDIMENTS AND IN THE POLYCHAETE NEREIS DIVERSICOLOR AT GROOT BUITENSCHOOR (SCHELDT ESTUARY,BELGIUM)

Water, Air, &; Soil Pollution - Total mercury (Hg) and methylmercury (MeHg) concentrations were determined in sediments and in the polychaete worm Nereis diversicolor at 13 stations of a...     

Mercury contamination of the harbour porpoise Phocoena phocoena and other cetaceans from the North Sea and the kattegat

Total Hg levels were determined in 17 harbour porpoises Phocoena phocoena collected in the North Sea and the Kattegat (muscle, liver and kidney), as well as in a sperm whale Physeter macrocephalus, a common dolphin Delphinus delphis and two bottle-nose dolphins Tursiops truncatus collected in Belgium. Juvenile porpoises (total body length less than 140 cm) were characterized by total Hg concentrations increasing with length (t.i. with age) with median values of 3.1 μg g^?1 dw in muscle, 6.2 in liver and 5.7 in kidney, and liver to muscle resp. liver to kidney ratios varying between 1 and 2. In adults, liver concentrations were higher (up to 500 μg g^?1 dw) with liver to muscle and to kidney ratios up to 20. Median McHg concentrations in 5 of the porpoises were 4.0 μg g^?1 dw in muscle and 6.9 in liver. These values did not increase as strongly with length (t.i. with age, at least for juveniles) as total Hg did; as a consequence, the relative McHg levels decreased from 100% in juveniles to 2 or 3 % in the liver of adults. Such results seem to reflect the existence of a slow mineralization phenomenon and storage of inorganic Hg, mainly in the liver.     

Development of an autonomous early warning system for Bactrocera dorsalis (Hendel) outbreaks in remote fruit orchards

Developing an autonomous early warning system for detecting pest resurgence is an essential task to reduce the probabilities of massive Oriental fruit fly (Bactrocera dorsalis (Hendel)) outbreaks. By preventing pest outbreaks, farmers would be able to reduce their dependence on chemical pesticides. Chemical pesticide abuse often brings harmful consequences to human health and natural environments. Since an agroecological system can change at a fast rate due to the soil degradation and the environmental factors changes, the rise of pest density cannot be immediately detected by traditional methodologies. In this study, an autonomous early warning system, built upon the basis of wireless sensor networks and GSM networks, is presented to effectively capture long-term and up-to-the-minute natural environmental fluctuations in fruit farms. In addition, two machine learning techniques, self-organizing maps and support vector machines, are incorporated to perform adaptive learning and automatically issue a warning message to farmers and government officials via GSM networks when the population density of B. dorsalis significantly rises. The proposed system also provides sensor fault warning messages to system administrators when one or more faulty sensors give abnormal readings to the system. Then, farmers and government officials would be able to take precautionary actions in time before major pest outbreaks cause an extensive crop loss, as well as to schedule maintenance tasks to repair faulted devices. The experimental results indicate that the proposed early warning system is able to detect the incidents of possible pest outbreaks in a variety of seasonal conditions with sensitivity, specificity, accuracy, and precision around 98%, 100%, 100%, and 100%, respectively, as well as to transmit the early warning messages to farmers and government officials via Short Message Service using the GSM network. The proposed early warning system can be easily adopted in different fruit farms without extra efforts from farmers and government officials since it is built based on machine learning techniques, and the warning messages are delivered to their mobile phones as text messages. The proposed early warning system also shows great potential to assist farmers to update their pest control operations in the fruit farms, and help government officials to improve farming systems.     

Brominated phenols as auxin-like molecules

2,6-Dibromophenol (DBP) was reported as an auxin-like molecule using molecular quantum similarity measures. In this study, the auxin activity of this molecule and its chlorinated homologue is further determined using a bacterial biosensor: the auxin-inducible ipdC promoter of Azospirillum brasilense. We were able to demonstrate that DBP can induce gene expression, but to a lesser extent than the auxin indole-3-acetic acid (IAA) and that DBP is not an antagonist for the IAA signalling pathway. To investigate the role of the bromine groups, the molecule 2,6-dichlorophenol (DCP) was also tested for gene expression induction. However, no induction could be observed. In a second part, DBP and other molecules were modelled in the auxin-binding pocket of the plant auxin receptor TIR1 to evaluate theoretical binding energies. Both DBP and its chlorinated homologue DCP are not strong ligands compared to other known auxins such as IAA. The importance of a carboxylated side chain for optimal binding (and probably auxin activity) was demonstrated.     

Urban plant species patterns are highly driven by density and function of built-up areas

This paper aims to assess the relative importance of the type of built-up area in structuring plant species composition and richness in urbanised environments. The study was carried out in the city of Brussels where all vascular plant species were recorded in 189 grid cells of 1 km² each. The effect of urban land use type on species composition was investigated using first Canonical Correspondence Analysis. Densely built-up area was the most powerful predictor for species composition, followed by industrial built-up areas, half open or open built-up areas with plantations, and open built-up areas with much natural vegetation in the surroundings. Indicator species were found for each type of built-up area and a response curve to the amount of built land was produced using Generalised Additive Modelling. Various types of built-up areas had different effects on environmental conditions as inferred by Ellenberg’s indicator values, as well as on the species richness, species rarity, number of exotic species and proportion of extinction-prone species. It is concluded that future ecological studies should not treat urban areas as homogeneous areas by combining all anthropogenic factors into one aggregated variable. Instead, the urban matrix should be categorised in subsystems as it is multidimensional and highly variable across space.