Desert methane: Implications for life detection on Mars

Methane, a potential biosignature, has recently been detected in the martian atmosphere. This Note focuses on field investigations/operational simulations and laboratory studies which resulted in successful detection of methane within arid terrestrial soils, as distinct from the usual methanogen environment, but in at least partial analogy to martian conditions.     

Participation in payments for ecosystem services: Case studies from the Lacandon rainforest, Mexico

Understanding people’s willingness to participate in projects and programmes of payments for ecosystem services (PES) has not been a key analytical concern of the scholarly literature around this new field of environmental policy and practice. This paper analyses participation in four communities benefiting from payments for biodiversity and carbon fixation in Mexico, and contrasts the results for each case with neighbouring communities that do not receive payments. We take a holistic approach that accounts for procedural rules, actors’ interactions, institutions and values, and individuals’ characteristics. We show that the nature of PES rules and the effectiveness of communication with government officers and NGOs influence resource managers’ ability and willingness to participate. We highlight community size, resource managers’ ability to diversify livelihood activities and local perspectives on the conservation of common forests, particularly sacred values and intergenerational concerns on forest conservation, as critical participation drivers. This analysis provides insights on why and how these new institutions may be attractive for some resource managers and permits to draw some recommendations for the future design of PES projects and programmes.     

基于数据挖掘探析张奇文治疗癫痫的用药规

目的：基于数据挖掘技术探析全国名中医张奇文治疗癫痫的用药规律。方法：收集1998年9月1日至2019年9月30日张奇文治疗癫痫的医案,对医案中的数据进行规范化处理,构建数据库,应用古今医案云平台V2.3.5对中药使用频次、四气五味、功效归经、关联、聚类等进行分析,并总结临床经验。结果：共筛选出40首处方,中药120味。排前10位的中药分别为全蝎、蜈蚣、僵蚕、炙甘草、麦芽、山楂、钩藤、羚羊角、珍珠、牛黄,药性以平、温为主,药味主要为甘、辛、苦,主要归肝、肺、脾经,功效以通络止痛、攻毒散结、息风镇痉等为主。关联组合支持度高的组合为全蝎-蜈蚣、全蝎-僵蚕、僵蚕-蜈蚣、钩藤-全蝎、钩藤-蜈蚣。结论：张奇文治疗癫痫标本兼顾,治标重视息风,治本重视健脾。     

Examples of predominantly two-body orbits in the Sun-Jupiter asteroid system

Accurate numerical continuation of families of plane symmetric direct periodic orbits around the large primary in the Sun-Jupiter case of the restricted problem of three bodies allows the determination of the vertical branching points where families of three-dimensional symmetric periodic orbits bifurcate from the planar ones. Three families of plane periodic orbits, and the initial segments of ten bifurcating families of three-dimensional ones are determined. The stability of these families is examined and examples of their orbits are illustrated.     

International greenhouse gas inventory systems: A comparison between CORINAIR and IPCC methodologies in the EU

There are several different approaches currently taken by the 15 EU countries in compiling their IPCC inventories for the FCCC. Six countries (France, Ireland, Italy, Luxembourg, Portugal, Spain) use the CORINAIR system and then aggregate and reformat the data into the required IPCC format. Of the remaining countries, two strictly follow the IPCC methodology (Finland and Greece), five (Denmark, Germany, Netherlands, Sweden, United Kingdom) estimate emissions using a combination of national and IPCC methodologies, while the final two (Austria and Belgium) use a combination of national and CORINAIR methodologies (transformed to IPCC). Comparison of the national inventories in both the IPCC and CORINAIR formats shos some revealing discrepancies between the two systems at both sector and gas level that by chance cancel out when aggregated at the EU level.     

Ecophysiology of the saguaro cactus (Carnegiea gigantea) in the Saguaro National Monument: relationship to symptoms of decline

The purpose of this study was to examine physiological correlates to the phenomenon of epidermal browning and saguaro decline in Saguaro National Monument. Gas exchange characteristics, surface temperatures, and the extent of epidermal browning in tissues of both healthy and declining saguaro cacti (Carnegiea gigantea) at different solar orientations were examined in eight long-term monitoring plots in the Rincon Mountain District of the Saguaro National Monument near Tucson, Arizona during both wet and dry seasons and years.Daily maximum surface temperatures were greatest on west-oriented tissues, as predicted by a simple model. However, south- and south-west-oriented tissues showed the highest browning indices, suggesting that browning may be more related to cumulative thermal loading than to extreme late afternoon temperature events. During the wet season, maximum nocturnal CO₂uptake rates and total nocturnal CO₂uptake were negatively correlated with browning index. Uptake rates during dry seasons and dry years was minimal, and not related to browning indices. However, healthy tissues of saguaros that also had tissues with high browning indices had wet-season maximum CO₂uptake rates as high as saguaros without damaged tissues, suggesting that the browning is not systemic but rather is tissue- and angle-specific. Instantaneous measures of water-use efficiency did not vary significantly or predictably by angle, but rather were greatest during night-time and in tissues when CO₂uptake was greatest. We suggest that browning symptoms on cacti are most likely due to natural abiotic stress, and are unrelated to systemic pollution stress or increased UV-B radiation.