Heavy metal distribution and controlling factors within coastal plain sediments, Bells Creek catchment, southeast Queensland, Australia

Bells Creek catchment in southeast Queensland (Australia) is a non-industrialised coastal plain limited to small settlements and agricultural land. A study was initiated to examine elevated metal concentrations and to assess horizontal and vertical distribution of those elements. Ninety-nine samples were analysed for Cr, V, Ni, Cu, Zn, Pb, As, Fe, Mn and Al. Total organic carbon, sulfur content and mineralogy of samples along with land-use practices across the catchment were used to identify processes which influence metal distribution. A comparison between metal concentration within the study area and mean heavy metal content of standard sandstone showed that except for Mn, all other metals showed elevated levels throughout the catchment. When metal concentrations were compared to parent bedrock, however, it was concluded that elevated levels are likely to be natural. A normalisation procedure was applied to the data set and this analysis validated that elevated trace metal concentrations in most samples are not due to artificial contamination. While surficial estuarine sediments were only enriched in V, soils were dominantly enriched in Cr, Zn and V. Overall, geochemistry and mineralogy of the samples show the effect of both natural and anthropogenic inputs to the catchment, however, natural processes are more dominant than anthropogenic inputs in concentrating metals.     

The use of image fusion in prenatal medicine

Fusion imaging (FI), the simultaneous display of the same anatomical region using two imaging modalities, has been used in other areas of medicine for both diagnosis and guiding interventions. Examples include positron emission tomography-computed tomography (PET-CT) imaging in oncology and ultrasound-magnetic resonance imaging (US-MRI) fusion in biopsies of the prostate gland. The underlying principle is to take advantage of the complementary information in each modality to improve accuracy, be it diagnostic accuracy or targeting accuracy in biopsies. For example, PET-CT overlays the metabolic activity of lesions on the superb spatial and anatomical detail of CT. While the historical mainstay of fetal imaging has been ultrasound, advances in ultrafast MR imaging together with advances in fetal MRI over the past two decades, have resulted in the opportunity to explore fusion imaging in fetal medicine. We present an overview of the principles of US-MRI fusion imaging in prenatal medicine, report our local experience, and review the literature in this emerging area. We share our perspective on how FI can improve diagnostic confidence, be used as an educational tool, and potentially enhance guidance in certain fetal procedures.     

The use of fetal MRI for renal and urogenital tract anomalies

Fetal anomalies are detected in approximately 2% of all fetuses and, among these, genitourinary tract abnormalities account for 30% to 50% of all structural anomalies present at birth. Although ultrasound remains the first line diagnostic modality, fetal MRI provides important additional structural and functional information, especially with the development of faster sequences and the use of functional sequences. The added value of MRI-based imaging is three-fold: (a) improvement of diagnostic accuracy by adequate morphological examination, (b) detection of additional anomalies, and (c) in addition, MRI has the potential to provide information regarding renal function. In this review, we describe the role of fetal MRI in the anatomical evaluation of renal and urogenital tract anomalies, and we also touch upon the contribution of functional MRI to the diagnostic workup of these conditions.     

Participatory assessment of the sustainability of livelihoods in the agroecosystem of Abesard,Iran

In order to improve the livelihoods of communities and make them more sustainable, study of the vulnerability of livelihoods seems necessary. In this paper, participatory vulnerability analysis was used within a sustainable rural livelihoods framework to assess the sustainability of livelihoods in the agroecosystem of Abesard, Iran. In addition, this paper explored vulnerability contexts that affect livelihood assets. Findings revealed that land use change, climate variability, market fluctuations and higher mechanisation were the main reasons of vulnerability. To overcome these problems and to adapt to changes, households have followed livelihood strategies such as agricultural intensification, livelihood diversification, and agricultural biodiversity. The government has also provided some services such as extension programmes, fertilizers, and subsidies to compensate for asset limitations. Overall, implementation of the following development policies are recommended: (1) support of agricultural production by government institutions; (2) moving towards the development of sustainable agricultural practises that integrate a variety of methods in a sustainable manner; (3) development of agricultural intensification in a sustainable way that compensates for any inadequacy of assets; and (4) providing adult vocational training programmes for both men and women related to on-farm and off-farm activities. In the end, results highlighted the need for more emphasis on overcoming the challenges of sustainable agriculture using a participatory approach in assessment of the vulnerability of community livelihoods.     

输电线路受外力破坏应变监测方法研究

输电线路通过金具与杆塔连接,线路受力直接传递到金具上,因此,金具可以反映线路的受力.基于这一原理,提出通过金具表面应变变化监测输电线路受力破坏情况.利用输电线路模拟试验台进行应变试验,应变片分别黏贴在金具不同部位,通过对线路施加载荷,测量应变信号.结果表明,金具某些部位应变变化与受力之间成线性关系,适合作为检测信号以监...