An example of fingerprint detection of greenhouse climate change

As an example of the technique of fingerprint detection of greenhouse climate change, a multivariate signal or fingerprint of the enhanced greenhouse effect is defined using the zonal mean atmospheric temperature change as a function of height and latitude between equilibrium climate model simulations with control and doubled CO₂ concentrations. This signal is compared with observed atmospheric temperature variations over the period 1963 to 1988 from radiosonde-based global analyses. There is a significant increase of this greenhouse signal in the observational data over this period.These results must be treated with caution. Upper air data are available for a short period only, possibly too short to be able to resolve any real greenhouse climate change. The greenhouse fingerprint used in this study may not be unique to the enhanced greenhouse effect and may be due to other forcing mechanisms. However, it is shown that the patterns of atmospheric temperature change associated with uniform global increases of sea surface temperature, with El NinoSouthern Oscillation events and with decreases of stratospheric ozone concentrations individually are different from the greenhouse fingerprint used here.     

Calculation of the visible-UV absorption spectra of hydrogen sulfide,bisulfide, polysulfides,and As and Sb sulfides,in aqueous solution

Recently we showed that visible-UV spectra in aqueous solution can be accurately calculated for arsenic (III) bisulfides, such as As(SH)₃, As(SH)₂S^- and their oligomers. The calculated lowest energy transitions for these species were diagnostic of their protonation and oligomerization state. We here extend these studies to As and Sb oxidation state III and v sulfides and to polysulfides S _n ^2- , n = 2–6, the bisulfide anion, SH^-, hydrogen sulfide, H₂S and the sulfanes, S _n H₂, n = 2–5. Many of these calculations are more difficult than those performed for the As(iii) bisulfides, since the As and Sb(v) species are more acidic and therefore exist as highly charged anions in neutral and basic solutions. In general, small and/or highly charged anions are more difficult to describe computationally than larger, monovalent anions or neutral molecules. We have used both Hartree-Fock based (CI Singles and Time-Dependent HF) and density functional based (TD B3LYP) techniques for the calculations of absorption energy and intensity and have used both explicit water molecules and a polarizable continuum to describe the effects of hydration. We correctly reproduce the general trends observed experimentally, with absorption energies increasing from polysulfides to As, Sb sulfides to SH^- to H₂S. As and Sb(v) species, both monomers and dimers, also absorb at characteristically higher energies than do the analogous As and Sb(III)species. There is also a small reduction in absorption energy from monomeric to dimeric species, for both As and Sb III and v. The polysufides, on the other hand, show no simple systematic changes in UV spectra with chain length, n, or with protonation state. Our results indicate that for the As and Sb sulfides, the oxidation state, degree of protonation and degree of oligomerization can all be determined from the visible-UV absorption spectrum. We have also calculated the aqueous phase energetics for the reaction of S₈ with SH^- to produce the polysulfides, S _n H^-, n = 2–6. Our results are in excellent agreement with available experimental data, and support the existence of a S₆ species.     

U–Pb SHRIMP zircon dating of Grenvillian metamorphism in Western Sierras Pampeanas (Argentina): Correlation with the Arequipa-Antofalla craton and constraints on the extent of the Precordillera Terrane

Metamorphism of Grenvillian age (ca. 1.2 Ga; U–Pb zircon dating) is recognized for the first time in the Western Sierras Pampeanas (Sierra de Maz). Conditions reached granulite facies (ca. 780 °C and ca. 780 MPa). Comparing geochronological and petrological characteristics with other outcrops of Mesoproterozoic basement, particularly in the northern and central Arequipa-Antofalla craton, we suggest that these regions were part of a single continental crustal block from Mesoproterozoic times, and thus autochthonous or parautochthonous to Gondwana.     

华北北部中生代岩墙群

岩墙群是深源岩浆浅侵位的产物，它可提供有关壳-幔演化的重要信息。通过华北北部大同早中生代碳酸岩-煌斑岩岩墙群、赤峰早中生代闪长玢岩岩墙群、林西中生代辉绿岩岩墙群、京北晚中生代双峰式岩墙群的对比研究，揭示了华北中生代存在的两次底侵作用及其相关的伸展作用。华北早、晚中生代岩墙群与晋北地区元古代岩墙群的初步对比，从一个侧面反映了华北壳幔的演变。     

Spatial characterisation of the Benguela ecosystem for ecosystem-based management

The three countries of the Benguela Current Large Marine Ecosystem (BCLME), namely Angola, Namibia and South Africa, have committed to implementing ecosystem-based management (EBM) including an ecosystem approach to fisheries (EAF) in the region, to put in practice the principles of sustainable development in ocean-related matters. There is also recognition of the need for marine spatial planning (MSP) as a process for informing EBM with regard to the allocation and siting of ocean uses so that ecosystem health is ensured and trade-offs between ecosystem services are appropriately dealt with. Marine spatial planning is both an integrated and an area-based process, and this paper produces a spatial characterisation of the BCLME for achieving a common basis for MSP in the region, focusing on the oceanography, biology and fisheries. Recognising spatial variation in physical driving forces, primary and secondary production, trophic structures and species richness, four different subsystems are characterised: (1) north of the Angola–Benguela Front, (2) from the Angola–Benguela Front to Lüderitz, (3) from Lüderitz to Cape Agulhas, and (4) from Cape Agulhas to Port Alfred on the south-east coast of South Africa. Research and monitoring requirements of relevance for MSP and EBM in the region are identified, focusing on understanding variability and change, including with regard to the boundary areas identified for the system. To this end, 14 cross-shelf monitoring transects are proposed (including seven that are already being monitored) to estimate fluxes of biota, energy and materials within and between the subsystems. The usefulness of models for understanding ecosystem variability and changes is recognised and the need for fine-scale resolution of both sampling and modelling for adequate MSP as input to EBM for the often-conflicting interests of conserving biodiversity, and managing fisheries, recreation, offshore oil and gas exploration and exploitation, offshore mining and shipping routes, is emphasised.     

Use of probiotic bacteria to improve growth and survivability of farmed New Zealand abalone (Haliotis iris)

The effects of two probiotic feeds containing two and three bacterial isolates were evaluated on the growth performance of New Zealand abalone (Haliotis iris). Probiotic bacteria were isolated from the guts of healthy adult abalone. The isolates were screened qualitatively and quantitatively according to their ability to hydrolyse nutrients (i.e. proteins, starch and alginate), produce acid and resist bile salts. Based on the screening results, we developed a multi-strain conglomerate of 2- and 3- probiotic bacterial strains that were supplemented into a commercial abalone feed to use in our experiments. The 2-probiotic conglomerate consisted of Exiguobacterium JHEb1 and Vibrio JH1, and the 3-probiotic conglomerate consisted of Exiguobacterium JHEb1, Vibrio JH1 and Enterococcus JHLDc. The probiotic feeding trial involved abalone juveniles (20–30 mm in maximum shell length). Both probiotic feeds significantly improved abalone growth compared to that of the unsupplemented feed. The 3-probiotic supplemented feed produced a significant shell length increase of 20.9%, a wet weight gain of 19.8% and a five-fold reduction in mortality compared to the controls. The 2-probiotic supplemented feed resulted in significant increases in shell length (15.4%) and reduced mortality (five-fold), but not in weight gain, compared to controls.     

Effect of size grading on the growth performance of shortfin eel (Anguilla australis) during its yellow stage

It is generally believed that size grading in a fish farm improves the total biomass output, because it will minimise the stress imposed by larger individuals over small individuals, resulting in higher feed intake and growth rate. The objective of this study was to evaluate the effect of size grading on individual growth performance of yellow New Zealand shortfin eel (Anguilla australis). A 109 day trial was conducted in a recirculation aquaculture system (RAS) with 103 eels of similar initial weight (101 ± 12 g). All eels were individually marked by PIT (passive integrated transponder) tags. On day 42, eels were graded to establish the following groups: only small eels (S-graded ≤ 135 g), only large eels (L-graded > 135 g), and small and large eels together (S-ungraded and L-ungraded). The large eels showed better specific growth rate (SGR), feed intake (FI) and feed conversion ratio (FCR) than the small eels. Nevertheless, no significant differences were found either between L-graded and L-ungraded or between S-graded and S-ungraded. The age of eels was not significantly different between groups. These findings suggest that the individual growth rate performance of the eels is not primarily a consequence of social interaction among tank-mates.     

块系岩体间黏弹性性质对摆型波传播的影响

基于深部非连续自应力等级块系岩体构造理论,研究冲击载荷在块系岩体中以摆型波形式传播时岩块间黏弹性性质对摆型波传播的影响。当岩块间具有五种不同黏弹性性质时,通过对块系岩体的始端和末端区域中间岩块加速度响应计算及各岩块加速度正负摆幅幅值分析可知：岩块间黏性变化时,对岩块加速度衰减周期没有影响,但黏性增大时各岩块正负摆幅下降幅度比黏性周期增大时大;岩块间弹性变化时岩块加速度衰减周期均发生变化,但弹性减小时正负摆幅值向平衡位置平移,弹性周期减小时块系岩体的前半部分岩块正负摆幅曲线均出现波动且负摆波动较大,岩块间弹性梯级增大时,岩块加速度迅速衰减,同时各岩块加速度的正负摆幅曲线在初始端区域出现波动。     

NDCI法Ⅱ类水体叶绿素a浓度高光谱遥感数据估算

以太湖、巢湖为研究区,以Hyperion和HJ-1A卫星HSI高光谱数据以及实测水质浓度数据为实验数据,引入归一化叶绿素指数(NDCI),对Ⅱ类水体的高光谱叶绿素a浓度估算进行分析研究.首先对高光谱数据的光谱通道设置以及水体光谱特征进行分析,研究确定模型的最优波段.然后,将确定最优波段后的NDCI反射率因子作为变量与实测样本点数据进行回归分析,得到NDCI与叶绿素a浓度之间的回归关系,进行叶绿素a浓度的估算.与常用的比值法、一阶微分法和三波段法相比,NDCI的性能优于这3种方法,表明NDCI是一种计算简单、估算精度高、实用性强的Ⅱ类水体叶绿素a浓度估算方法.     

Estimating periphyton standing crop in streams: a comparison of chlorophyll a sampling and visual assessments

Periphyton standing crop is often measured as chlorophyll a but there is increasing interest in using visual assessments of periphyton cover. Visual methods are rapid and require no sample analysis, but can be regarded as subjective with high inter-operator variability. We investigated variability in periphyton standing crop across operators, rivers and time, as determined visually and from chlorophyll a measurements. We found that visual assessments (comprising percentage cover estimates of up to eight periphyton categories) distinguished sites and occasions as effectively as chlorophyll a. Furthermore, an estimate of chlorophyll a could be derived from the visual assessments. Because our surveys were conducted in only three rivers, general applicability of the derivation of estimated chlorophyll a from the visual assessments warrants further investigation. The current recommendation of 20 views was sufficient for realistic visual assessments of average cover. Overall, our results indicated that inter-operator variability in visual assessments need not be a major concern, given adequate training.