Effect of Cropping System on Physical Properties of Clay Soil Under Intensive Rice Cultivation

Cropping systems are thought to alter soil quality in paddy rice fields. This study was conducted to quantify the long‐term effects of continuous crop production under different cropping systems with different crop rotations on physical properties of alluvial clay soil in the Mekong Delta, Vietnam. Soil samples were collected from four treatments: (i) traditional intensive rice monoculture with three rice crops per year (R–R–R); (ii) rotation with two rice crops and maize (R–M–R); (iii) rotation with two rice crops and mung bean (R–Mb–R); and (iv) rotation with one rice and two upland crops, mung bean and maize (R–Mb–M). We hypothesized that cropping systems with rotations of upland crops and their temporary beds improve the physical quality of paddy rice soil; hence, they are better options towards sustainable agriculture. Results show an improvement of soil physical quality for systems with two rice crops and one upland crop (R–M–R and R–Mb–R) and those with one rice crop with two upland crops (R–Mb–M) compared with intensive rice monoculture (R–R–R). This was translated in decreased bulk density and soil strength, increased soil organic carbon and total porosity, and higher aggregate stability index, plant‐available water capacity, and Dexter's S index, especially at depths of 10–20 and 20–30 cm. The systems with different upland crops (maize or mung bean) showed similar high physical quality improvement. To maintain soil quality in future seasons, introducing a cropping system with at least one upland crop in rotation with rice is recommended. Copyright © 2014 John Wiley & Sons, Ltd.     

Chemical composition and antioxidant activity of yerba-mate (Ilex paraguariensis A.St.-Hil., Aquifoliaceae) extract as obtained by spray drying

Yerba-mate or mate? (Ilex paraguariensis A.St.-Hil., Aquifoliaceae) leaves are typically used for their stimulant, antioxidant, antimicrobial, and diuretic activity, presenting as principal components polyphenolic compounds. In this study, the objective was to develop a yerba-mate dry extract by using spray drying technology and to evaluate the dry extract antioxidant activity and chemical composition. The results obtained by means of the DPPH assay show that the extract presents an IC(50) of 2.52 mg/mL. The yerba-mate spray-dried extract presents high catalase-like activity, suggesting that it is a strong free-radical scavenger. The antioxidant activity as expressed as catalase-like activity was related to total polyphenol content. In addition, the results show that the spray-dried extract presents high polyphenol content, namely, high concentrations of caffeic acid (1.54 mg/g), 5-caffeoylquinic acid (91.40 mg/g), rutin (5.38 mg/g), and total phenolics (178.32 mg/g), which justifies its high antioxidant activity.     

Validation of the tetrasensor honey test kit for the screening of tetracyclines in honey

Regarding anti-infectious agents, no maximum residue limits are fixed for honey in the European legislation. Discussions are being conducted in order to set working limits at the European level; for example, for tetracyclines, 20 microg/kg was proposed. The Tetrasensor Honey test kit is a receptor-based assay using dipsticks for a rapid screening (30 min) of honey on the presence of tetracyclines. The test was validated according to Commission Decision 2002/657/EC. The test detects tetracycline, oxytetracycline, chlortetracycline, and doxycycline in honey in a specific and sensitive way. Depending on the type of tetracycline, detection capabilities (CCbeta) between 6 and 12 microg/kg were obtained (4-7 microg/kg for dried dipsticks). The test is rugged and participation with the test in an international ring trial gave compliant results. It can be concluded that the Tetrasensor Honey test kit is a simple and reliable test that can even be used at the production site.     

Managing scarce water resources in Asia: The nature of the problem and can remote sensing help?

Water demands are outstripping supplies in many parts of Asia and causing conflicts, especially as rapidly urbanizing and industrializing areas compete with more traditional agriculture on alluvial plains near expanding metropolises. The environment is increasingly being seen as a legitimate and important user of water, often in competition with irrigation, domestic, industrial, hydropower and community uses of water. Any future scenario requires an improvement in water productivity, especially in agriculture. Surface and ground water supplies are not well regulated owing primarily to a weak knowledge base, analytical capacity in addition to a number of traditional institutional, governance, political and other factors. Water policy makers have, therefore, to work out strategies for integrated water and environmental management, which rely on a proper knowledge base of the basin hydrological and pollution conditions. Examples from various countries in Asia are elaborated in this paper to demonstrate how spatially distributed evapotranspiration data from remote sensing, in conjunction with other key data, can help to build the knowledge base for integrated basin scale water management. Remote sensing is not a solution, but it provides key data that is difficult to access by conventional data collection methods.     

Mutations in CIC and FUBP1 contribute to human oligodendroglioma

Oligodendrogliomas are the second most common malignant brain tumor in adults and exhibit characteristic losses of chromosomes 1p and 19q. To identify the molecular genetic basis for this alteration, we performed exomic sequencing of seven tumors. Among other changes, we found that the CIC gene (homolog of the Drosophila gene capicua) on chromosome 19q was somatically mutated in six cases and that the FUBP1 gene [encoding far-upstream element (FUSE) binding protein] on chromosome 1p was somatically mutated in two tumors. Examination of 27 additional oligodendrogliomas revealed 12 and 3 more tumors with mutations of CIC and FUBP1, respectively, 58% of which were predicted to result in truncations of the encoded proteins. These results suggest a critical role for these genes in the biology and pathology of oligodendrocytes.     

Altered telomeres in tumors with ATRX and DAXX mutations

The proteins encoded by ATRX and DAXX participate in chromatin remodeling at telomeres and other genomic sites. Because inactivating mutations of these genes are common in human pancreatic neuroendocrine tumors (PanNETs), we examined the telomere status of these tumors. We found that 61% of PanNETs displayed abnormal telomeres that are characteristic of a telomerase-independent telomere maintenance mechanism termed ALT (alternative lengthening of telomeres). All of the PanNETs exhibiting these abnormal telomeres had ATRX or DAXX mutations or loss of nuclear ATRX or DAXX protein. ATRX mutations also correlate with abnormal telomeres in tumors of the central nervous system. These data suggest that an alternative telomere maintenance function may operate in human tumors with alterations in the ATRX or DAXX genes.     

Cortex is driven by weak but synchronously active thalamocortical synapses

Sensory stimuli reach the brain via the thalamocortical projection, a group of axons thought to be among the most powerful in the neocortex. Surprisingly, these axons account for only approximately 15% of synapses onto cortical neurons. The thalamocortical pathway might thus achieve its effectiveness via high-efficacy thalamocortical synapses or via amplification within cortical layer 4. In rat somatosensory cortex, we measured in vivo the excitatory postsynaptic potential evoked by a single synaptic connection and found that thalamocortical synapses have low efficacy. Convergent inputs, however, are both numerous and synchronous, and intracortical amplification is not required. Our results suggest a mechanism of cortical activation by which thalamic input alone can drive cortex.