陆地生态系统的恢复--模拟全球变化所引起的酸性输入减少和海盐输入增加的影响

到2010年<哥德堡议定书>正式实施时,欧洲自20世纪70年代末以来已减少的酸化硫和氮释放量将进一步减少.这里我们论述了通过使用应用于3个大型"清洁雨"实验(即分别在挪威里斯达尔谢伊阿[Risdalsheia],瑞典耶德松[Gardsjon]以及丹麦克洛斯特海泽[Klosterhede]的所谓"屋顶实验")的酸化模型MAGIC讨论恢复酸化陆地生态系统的结果.<哥德堡议定书>的实施将启动通过重建盐基饱和恢复上述3处土壤的进程.恢复率较低,在今后30年中,盐基饱和增加不足5%.气候引发的风暴严重性的加剧将增加海盐输入生态系统的量.这将为土壤提供额外的碱阳离子,并使恢复速度翻一番,同时还将随着沉积的碱阳离子与存储在土壤中的酸性交换导致高海盐输入之后的强酸性脉动.因此,酸化集水区土壤和径流的进一步恢复将取决于酸沉积下降的数量和速率,在近岸系统的情况下,还取决于海盐输入事件的频率和强度.     

Energy use and transport correlation linking personal and travel related energy uses to the urban structure

This paper considers relationships between sustainability objectives, transport, spatial design of the built environment and rational use of energy. Conventional transport modelling, housing supply and energy assessment tools are drawn together to provide a common platform for appraisal of city-wide energy use by stationary and mobile sources. The paper outlines methodologies developed for the city of Belfast, Northern Ireland. The paper concludes by briefly reviewing the effect in terms of mobile and stationary energy consumption and travel behaviour of implementing sustainable policy measures in current and future years within the study area.     

Scale,context, and decision making in agricultural adaptation to climate variability and change

This work presents a framework for viewing agricultural adaptation, emphasizing the multiple spatial and temporal scales on which individuals and institutions process information on changes in their environment. The framework is offered as a means to gain perspective on the role of climate variability and change in agricultural adaptation, and developed for a case study of Australian agriculture. To study adaptation issues at the scale of individual farms we developed a simple modelling framework. The model highlights the decision making element of adaptation in light of uncertainty, and underscores the importance of decision information related to climate variability. Model results show that the assumption of perfect information for farmers systematically overpredicts adaptive performance. The results also suggest that farmers who make tactical planting decisions on the basis of historical climate information are outperformed by those who use even moderately successful seasonal forecast information. Analysis at continental scales highlights the prominent role of the decline in economic operating conditions on Australian agriculture. Examples from segments of the agricultural industry in Australia are given to illustrate the importance of appropriate scale attribution in adapting to environmental changes. In particular, adaptations oriented toward short time scale changes in the farming environment (droughts, market fluctuations) can be limited in their efficacy by constraints imposed by broad changes in the soil/water base and economic environment occuring over longer time scales. The case study also makes the point that adaptation must be defined in reference to some goal, which is ultimately a social and political exercise. Overall, this study highlights the importance of allowing more complexity (limited information, risk aversion, cross-scale interactions, mis-attribution of cause and effect, background context, identification of goals) in representing adaptation processes in climate change studies.     

An Integrated Assessment of Climate Change and the Accelerated Introduction of Advanced Energy Technologies - An Application of MiniCAM 1.0

We report results from the application of an integrated assessment model, MiniCAM 1.0. The model is employed to explore the full range of climate change implications of the successful development of cost effective, advanced, energy technologies. These technologies are shown to have a profound effect on the future magnitude and rate of anthropogenic climate change. We find that the introduction of assumptions developed by a group of ‘bottom-up’ modelers for the LEESS scenarios into a ‘top-down’ model, the Edmonds-Reilly-Barns Model, leads to ‘top down’ emissions trajectories similar to those of the LEESS. The cumulative effect of advanced energy technologies is to reduce annual emissions from fossil fuel use to levels which stabilize atmospheric concentrations below 550 ppmv. While all energy technologies play roles, the introduction of advanced biomass energy production technology is particularly important. The consideration of all greenhouse related anthropogenic emissions, and in particular sulfur dioxide, is found to be important. We find that the consideration of sulfur dioxide emissions coupled to rapid reductions in carbon dioxide emissions leads to higher global mean temperatures prior to 2050 than in the reference case. This result is due to the short-term cooling impact of sulfate aerosols, which dominates the long-term warming impact of CO₂ and CH₄ in the years prior to 2050. We also show that damage calculations which use only mean global temperature and income may be underestimating damages by up to a factor of five. Disaggregating income reduces this to a factor of two, still a major error. Finally, the role of the discount rate is shown to be extraordinarily important to technology preference.     

Prenatal diagnosis,fetal pathology,and cytogenetic analysis of mosaic trisomy 14

While true mosaicism occurs in only 0–25 per cent of genetic amniocenteses, nearly 2–5 per cent of amniotic fluid cell cultures contain a second cell line. In the common practice of prenatal diagnosis, an aberrant cell line confined to a single colony is usually disregarded. We present a case of mosaic trisomy 14 which was not detected on initial chromosome analysis. At birth, multiple malformations were apparent. Newborn cytogenetic studies revealed mosaicism [46,XX/46,XX,-14,+i(14q)] with an isochromosome 14 in 37 per cent of lymphocytes. Additional cells from the initial amniotic fluid culture were analysed post-delivery and the isochromosome 14 identified in only one of 12 total colonies. This case illustrates two important lessons in prenatal diagnosis. First, amniotic fluid cell cultures may not accurately reflect the relative distribution of the normal and abnormal cell lines within a mosaic fetus. Second, while it is generally reasonable to disregard mosaicism confined to a single colony, this policy will, on rare occasion, result in diagnostic error. This should be taken into consideration, particularly when dealing with autosomal trisomies potentially compatible with livebirth.     

The functionality of female reciprocal calls in the Iberian midwife toad (<Emphasis Type="Italic">Alytes cisternasii</Emphasis>): female-female acoustic competition?

Female midwife toads (genus Alytes) emit highly variable reciprocal calls of unclear function prior to and during courtship. In some species, female-female competition, expressed as physical fighting, has been reported. Males of Majorcan midwife toads (Alytes muletensis) show phonotactic response to female calls, and females of Iberian midwife toads (Alytes cisternasii) respond differently according to the male call characteristics. In this study, I test the hypothesis of female-female acoustic competition as an additional function of female reciprocal calls. Playback tests indicate that female calls are not clearly involved in female acoustic competition in the Iberian midwife toad, therefore female calls could be directed at males rather than towards competitive females.     

Unemployment effects of climate policy

This paper models the unemployment effects of restrictions on greenhouse gas emissions, embodying two of the most significant types of short-term economic imperfections that generate unemployment: sectoral rigidities in labor mobility and sectoral rigidities in wage adjustments. A labor policy is also analyzed that would reduce the direct negative economic effects of the emissions restrictions.The politics of limiting greenhouse gas emissions are often dominated by relatively short-term considerations. Yet the current economic modeling of emissions limitations does not embody economic features that are likely to be particularly important in the short term, in particular, the politically sensitive unemployment rate. Moreover, only a few of these studies also consider policies that would offset the negative direct economic effects of emissions restrictions. For plausible estimates of the parameters, the model shows that, with the labor market imperfections, if there were no offsetting policies, the reductions in GNP in the U.S. in the first 10 years after emissions restrictions were imposed would be as much as 4%. However, if there were two policies, instead of just one: a counteracting labor market policy, as well as the emissions restrictions, the negative direct economic effects could be completely eliminated.     

Meckel-Gruber syndrome: Prenatal diagnosis at 10 menstrual weeks using embryoscopy

A case of Meckel—Gruber syndrome was diagnosed by embryoscopy at 10 menstrual weeks, allowing for early termination of pregnancy. Post-mortem examination confirmed the presence of polydactyly and bilateral cystic lesions of the mesonephros and metanephros. Both the forming nephrons and the collecting ducts were involved in the formation of renal cysts.