建立正常人肺血管容量的无创精确测量方法的初步报告*

目的: 由于传统呼吸调控环路忽略了对血液循环的决定性作用,肺（静脉）血管容量相关研究甚少,亟需建立肺血管容量测量方法。方法: 选择正常志愿者完成CT全肺扫描,图像数据经过计算机软件分析处理,从肺尖到肺底以40~50层进行肺野手工切划,相邻层间由计算机自动模拟连接,在去除干扰后进行全肺血管（≥0.6 mm）高精度三维立体成像技术处理,进而计算全肺和肺血管容积。结果: 12例正常志愿者从肺尖到肺底CT扫描图片层数为530±98（431~841）张。全肺和肺血管的总容积是3705±857（2398~5383）ml ,肺血管血液总的容积是125±32（94~201）ml。按肺静脉系统血管容量约为全肺血管血液容量一半计算,应该是63±16（47~100）ml。结论: 肺CT扫描数据分析三维立体成像建立肺血管容量无创测量方法精确可行。     

Fertilizer and manure equivalent rates on forage corn production (<i>Zea mays</i>)

An experiment with increasing rates of fertilizer and manure in silage corn was established to evaluate the agronomic crop response and to estimate the manure nitrogen availability. The treatments were designed to deliver 0, 67, 100 and 133% of the crop nitrogen requirements (CNR), using ammonium sulphate and manure as N source. Dry matter (DM) yield was similar among treatments receiving N, but those values were greater than those found in the control. Nitrogen extraction at harvest was not statistically different in treatments with fertilizer or manure, but it was higher in these treatments than in the control without N (p≤ 0.05). With both sources of N, crop N extraction was adjusted to a quadratic regression equation, as a function of N rates. According to the fertilizer equivalence (EF) methodology, the rate of 231.3 kg/ha of inorganic fertilizer N, and 752.9 kg/ha of total N in manure, had 129.5 kg/ha of N extracted by the crop. The ratio of the above rates, fertilizer N/ manure total N, represents the crop available manure N; in the present study, it was 30.7% of total N in the manure. Since no differences in yield were observed between N sources, it is concluded that N fertilizer can be substituted by manure, at a rate estimated to provide the crop N requirements. The estimation of the manure available N is important to adjust manure rates, thereafter avoiding excessive applications and pollution risks.     

Proteome analysis of low-abundance proteins using multidimensional chromatography and isotope-coded affinity tags

The effectiveness of proteome-wide protein identification and quantitative expression profiling is dependent on the ability of the analytical methodologies employed to routinely obtain information on low-abundance proteins, as these are frequently of great biological importance. Two-dimensional gel electrophoresis, the traditional method for proteome analysis, has proven to be biased toward highly expressed proteins. Recently, two-dimensional chromatography of the complex peptide mixtures generated by the digestion of unseparated protein samples has been introduced for the identification of their components, and isotope-coded affinity tags (ICAT) have been introduced to allow for accurate quantification of the components of protein mixtures by mass spectrometry. Here, we demonstrate that the combination of isotope coded affinity protein tags and multidimensional chromatography/mass spectrometry of tryptic peptide mixtures is capable of detecting and quantifying proteins of low abundance in complex samples.     

A global comparison of grassland biomass responses to CO2 and nitrogen enrichment

Grassland ecosystems cover vast areas of the Earth''s surface and provide many ecosystem services including carbon (C) storage, biodiversity preservation and the production of livestock forage. Predicting the future delivery of these services is difficult, because widespread changes in atmospheric CO₂ concentration, climate and nitrogen (N) inputs are expected. We compiled published data from global change driver manipulation experiments and combined these with climate data to assess grassland biomass responses to CO₂ and N enrichment across a range of climates. CO₂ and N enrichment generally increased aboveground biomass (AGB) but effects of CO₂ enrichment were weaker than those of N. The response to N was also dependent on the amount of N added and rainfall, with a greater response in high precipitation regions. No relationship between response to CO₂ and climate was detected within our dataset, thus suggesting that other site characteristics, e.g. soils and plant community composition, are more important regulators of grassland responses to CO₂. A statistical model of AGB response to N was used in conjunction with projected N deposition data to estimate changes to future biomass stocks. This highlighted several potential hotspots (e.g. in some regions of China and India) of grassland AGB gain. Possible benefits for C sequestration and forage production in these regions may be offset by declines in plant biodiversity caused by these biomass gains, thus necessitating careful management if ecosystem service delivery is to be maximized. An approach such as ours, in which meta-analysis is combined with global scale model outputs to make large-scale predictions, may complement the results of dynamic global vegetation models, thus allowing us to form better predictions of biosphere responses to environmental change.     

The livelihood impacts of oil palm: smallholders in Indonesia

The biodiversity and climate consequences of oil palm (Elaeis guineensis) expansion across South East Asia have received considerable attention. The human side of the issue, highlighted with reports of negative livelihood outcomes and rights abuses by oil palm companies, has also led to controversy. Oil palm related conflicts have been widely documented in Indonesia yet uptake by farmers has also been extensive. An assessment of the livelihood impacts of oil palm development, including sources of conflict, is needed to shed light on the apparent contradiction between these reports and the evident enthusiasm of farmers to join the oil palm craze thereby informing future expansion. We assessed the impact of oil palm development on the economic wellbeing of rural farmers in Indonesia. We found that many smallholders have benefited substantially from the higher returns to land and labour afforded by oil palm but district authorities and smallholder cooperatives play key roles in the realisation of benefits. Conflicts between communities and companies have resulted almost entirely from lack of transparency, the absence of free, prior, and informed consent and unequal benefit sharing, and have been exacerbated by the absence of clear land rights. We make specific recommendations to improve the present situation and foster the establishment of smallholder friendly production regimes. Oil palm expansion in Indonesia is set to continue. If environmental standards can be raised and policy interventions targeted at the broader social impacts of land development this expansion may be achieved to the significant benefit of large numbers of rural smallholders.     

The Importance of Hunting and Habitat in Determining the Abundance of Tropical Forest Species in Equatorial Guinea

Understanding the impact of hunting on wildlife populations is crucial to achieving sustainability and requires knowledge of prey abundance responses to different levels of exploitation. While the abundance of primates has been shown to respond independently to hunting and habitat, habitat is rarely considered simultaneously when evaluating the impacts of hunting. Furthermore, the importance of these two factors in determining the abundance of other species has not been well investigated. We evaluate the independent effects of hunting and habitat on the abundance of a diverse assemblage of species, using a series of predictions and data from a study in Equatorial Guinea. Line transect surveys in sites of varying hunting intensity and habitat, and weekly interviews with hunters on current hunting effort in each site, were conducted. We also consider the role of past hunting, and discuss the interrelationships between hunting and habitat variables. We show that for primates, hunting is important in determining abundance, while for rodents and duikers, habitat is more important. Our findings show that the effects of hunting and habitat on abundance vary greatly between species, are often confounded and require an approach that isolates their independent effects to determine the true impact of hunting. Conservation managers must consider and incorporate habitat heterogeneity when managing hunting systems, taking into account the way in which the relative importance of these factors can vary between species.     

Small grains for starch production

Wheat, sorghum, rice, barley, oat and rye grains are actual or potential raw materials for the industrial production of starch, but only the first three are so used. All six contain about 60% to 70% starch, and yield oil and protein as valuable byproducts of starch manufacture. Successful competition of these grains with the present major industrial sources of starch— corn, potatoes and cassava— depends on a number of factors, including comparative costs of the raw materials, efficiency of processing methods, and value of the byproducts.