Chemical characterization and DNA tracking of Sardinian botargo by Mugil cephalus from different geographical origins

The chemical composition of the Sardinian botargo by Mugil cephalus from different geographical origins was investigated. Fat ( approximately 20%), proteins ( approximately 50%), moisture ( approximately 22%), and salt ( approximately 7%) were measured in ground (G) and whole (W) commercial products. Among the nutritional compounds, omega-3 fatty acids were approximately 8%, squalene was approximately 15 mg/100 g, vitamin E was approximately 8.5 mg/kg, and cholesterol was approximately 300 mg/100 g, on average in both products. Antioxidant properties, assessed by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) test and expressed as Trolox equivalent antioxidant capacity (TEAC), showed quite good activity in extracted oil (0.8-1.1 mmol of Tolox/L). Major constituents in the samples varied noticeably, but only few statistical differences were evidenced between G or W products or between samples from different origins. Principal component analysis (PCA) of random amplified polymorphic DNA (RAPD) and proteins, coupled with both, did not differentiate samples from different origins. On the basis of our results, chemical and molecular data exclude the differentiation of samples from diverse origins.     

Characterization of new bisphenol a metabolites produced by CD1 mice liver microsomes and S9 fractions

Bisphenol A [2,2-bis(4-hydroxyphenyl)propane] (BPA) is a widely used industrial chemical resulting in occupational and consumer exposure. BPA possesses weak estrogenomimetic activity and can be cytotoxic, though the underlying mechanisms of its toxicity toward cells are not completely understood. The metabolism of BPA by CD1 mice liver microsomal and S9 fractions was investigated. Nine metabolites were isolated and characterized using HPLC and mass spectrometry. Many of these metabolites were characterized for the first time in mammals, namely isopropyl-hydroxyphenol (produced by the cleavage of BPA), a bisphenol A glutathione conjugate, glutathionyl-phenol, glutathionyl 4-isopropylphenol, and BPA dimers. Most of these metabolites apparently share a common metabolic pathway, for which considerable evidence supports the hypothesis of the production of a reactive intermediate, and also helps explain BPA cytotoxicity.     

The Brazilian Atlantic Forest: How much is left, and how is the remaining forest distributed? Implications for conservation

The neotropical Atlantic Forest supports one of the highest degrees of species richness and rates of endemism on the planet, but has also undergone a huge forest loss. However, there exists no broad-scale information about the spatial distribution of its remnants that could guide conservation actions, especially when systematic biodiversity data are not available. In this context, our objectives were to quantify how much of the forest still remains, and analyze its spatial distribution. We considered the entire Brazilian Atlantic Forest, and eight sub-regions, defined according to species distribution. The results revealed a serious situation: more than 80% of the fragments are <50 ha, almost half the remaining forest is <100 m from its edges, the average distance between fragments is large (1440 m), and nature reserves protect only 9% of the remaining forest and 1% of the original forest. On the other hand, our estimates of existing Atlantic Forest cover were higher than previous ones (7-8%), ranging from 11.4% to 16%. The differences among estimates are mainly related to our inclusion of intermediate secondary forests and small fragments (<100 ha), which correspond to approximately 32-40% of what remains. We suggest some guidelines for conservation: (i) large mature forest fragments should be a conservation priority; (ii) smaller fragments can be managed in order to maintain functionally linked mosaics; (iii) the matrix surrounding fragments should be managed so as to minimize edge effects and improve connectivity; and (iv) restoration actions should be taken, particularly in certain key areas. The clear differences in the amount remaining and its spatial distribution within each sub-region must be considered when planning for biodiversity conservation.     

Correction to: Estimation of the area-specific suspended sediment yield from discrete samples in different regions of Belgium

Journal of Soils and Sediments -     

Gaseous emissions of nitrogen and carbon from urban vegetable gardens in Bobo‐Dioulasso,Burkina Faso

Urban and peri‐urban agriculture (UPA) is an important livelihood strategy for the urban poor in sub‐Saharan Africa and contributes to meeting increasing food demands in the rapidly growing cities. Although in recent years many research activities have been geared towards enhancing the productivity of this land‐use system, little is known about turnover processes and nutrient efficiency of UPA. The aim of our study therefore was to determine horizontal fluxes of N, P, K, and C as well as gaseous N and C emissions in urban vegetable gardens of Bobo‐Dioulasso, Burkina Faso. Two gardens referred to as “Kodéni” and “Kuinima” were selected as representative for urban and peri‐urban systems classified as: (1) “commercial gardening + field crops and livestock system” and (2) “commercial gardening and semicommercial field crop system”, respectively. A nutrient‐balance approach was used to monitor matter fluxes from March 2008 to March 2009 in both gardens. Ammonia (NH₃), nitrous oxide (N₂O) and carbon dioxide (CO₂) emissions from the respective soils were measured during the coolest and the hottest period of the day using a closed‐chamber system. Annual partial balances amounted to 2056 kg N ha^–1, 615 kg P ha^–1, 1864 kg K ha^–1, and 33 893 kg C ha^–1 at Kodéni and to 1752 kg N ha^–1, 446 kg P ha^–1, 1643 kg K ha^–1, and 21 021 kg C ha^–1 at Kuinima. Emission rates were highest during the hot midday hours with peaks after fertilizer applications when fluxes of up to 1140 g NH₃‐N ha^–1 h^–1, 154 g N₂O‐N ha^–1 h^–1, 12 993 g CO₂‐C ha^–1 h^–1 were recorded for Kodéni and Kuinima. Estimated annual gaseous N (NH₃‐N + N₂O‐N) and C (CO₂‐C + CH₄‐C) losses reached 419 kg N ha^–1 and 35 862 kg C ha^–1 at Kodéni and 347 kg N ha^–1 and 22 364 kg C ha^–1 at Kuinima. For both gardens, this represented 20% and 106% of the N and C surpluses, respectively. Emissions of NH₃, largely emitted after surface application of manure and mineral fertilizers, accounted for 73% and 77% of total estimated N losses for Kodéni and Kuinima. To mitigate N losses nutrient‐management practices in UPA vegetable production of Bobo‐Dioulasso would greatly benefit from better synchronizing nutrient‐input rates with crop demands.     

3-Sulfanylhexanol precursor biogenesis in grapevine cells: the stimulating effect of Botrytis cinerea

Volatile thiols, compounds that contribute strongly to the varietal aroma, are present in much higher concentrations in sweet wines than in dry wines. This positive effect, due to the presence of Botrytis cinerea on the berries, in fact results from a strong enrichment of cysteine S-conjugate precursors in botrytized berries. In the present study, a convenient model was investigated to reproduce and therefore study this phenomenon. A Vitis vinifera cell culture was used as a simple model, and we focused on S-3-(hexan-1-ol)-l-cysteine (P-3SH), the cysteinylated precursor of 3-sulfanylhexanol. We demonstrated that grapevine cells were able to produce P-3SH and that the presence of B. cinerea considerably increased the precursor level (up to 1000-fold). This positive result was determined to be due to metabolites secreted by the fungus. These molecules were temperature sensitive, unstable over time, and their production was activated in the presence of grapevine cells. Moreover, part of the pathway leading to P-3SH was deciphered: it was directly derived from the cleavage of S-3-(hexan-1-ol)-l-glutathione, which itself was generated after a conjugation of glutathione on (E)-2-hexenal.     

Protein kinase G from pathogenic mycobacteria promotes survival within macrophages

Pathogenic mycobacteria resist lysosomal delivery after uptake into macrophages, allowing them to survive intracellularly. We found that the eukaryotic-like serine/threonine protein kinase G from pathogenic mycobacteria was secreted within macrophage phagosomes, inhibiting phagosome-lysosome fusion and mediating intracellular survival of mycobacteria. Inactivation of protein kinase G by gene disruption or chemical inhibition resulted in lysosomal localization and mycobacterial cell death in infected macrophages. Besides identifying a target for the control of mycobacterial infections, these findings suggest that pathogenic mycobacteria have evolved eukaryotic-like signal transduction mechanisms capable of modulating host cell trafficking pathways.     

番茄形态结构模型参数的多目标拟合估算方法研究

对番茄生长模型参数进行准确估算是模型得以验证和面向应用的前提条件。基于番茄拓扑结构,采用非线性最小二乘优化方法,通过对植株形态数据的多目标拟合,实现模型参数的最优估计和校准。非线性最小二乘法的权值根据目标数据自动调整,使得不同量纲和不同数值范围的观测数据可以在同一水平上进行,提高了计算的精度和稳定性;另一方面用差商近似代替导数加快了算法的收敛速度。通过应用拟合优度检验,得出模型输出对观测值的拟合程度较好,说明模型合理,参数可靠。实践表明该估算方法是对模型进行验证的一个行之有效的方法。     

Urban Growth Boundaries and Betterment: Rent‐Seeking by Landowners on Melbourne's Expanding Urban Fringe

Melbourne's Urban Growth Boundary (UGB) was legislated in 2002 and expanded substantially in 2010. Although based on strategic planning goals, UGBs have the capacity to influence land and housing markets. Landowners on the rural–urban fringe are a stakeholder group directly impacted by UGB policy, with multiple interests in containment policies and any land‐value effects. Following the 2010 expansion, substantial windfall profits to “instant millionaire” Melbourne landowners were openly reported. This paper critically interprets claims made by landowners in 264 public submissions responding to the proposed UGB expansion, and to an accompanying new policy instrument, the Growth Areas Infrastructure Contribution (GAIC). The GAIC was, in effect, a hypothecated tax on betterment expected to result from the UGB shift. Landowners commonly expressed fears that the UGB shift would not result in claimed value increases. On this basis, the GAIC was revised such that it is—at least in intention—a system wherein the tax is to be paid by housing developers and passed forward to homebuyers. The paper argues that the series of changes to the UGB and GAIC, including the modified “purchaser pays” system, may be understood as a response to rent‐seeking policy pressures from existing landowners as “insiders.” Although the unpopularity of the GAIC with landowners might have been anticipated, the outcome appears to legitimise their misinterpretation of the premise of development gain. A broader implication is that rent‐seeking behaviour by existing property owners can determine whether and how strategic planning policies are implemented.