Lactation patterns of pinnipeds are not explained by optimization of maternal energy delivery rates

Within pinnipeds, phocids and otariids show differing maternal care strategies. Phocids rear young out of body stores in a yearly cycle with a single stay ashore when the mother fasts while lactating, whereas otariids provision their young by repeated foraging trips to sea alternating with brief stays ashore where they suckle their young. In a previous optimality model, these differences have been interpreted as adaptations based on differing energy requirements of large (phocid) and smaller (otariid) species, and the time budget of the large elephant and the much smaller Antarctic fur seal were correctly predicted. Our refined model—extended to pinniped species of all sizes—predicts lactation strategies to shift from attendance cycles to 1-year cycles with increasing body mass and provides an explanation for the finding that phocid pups are weaned at lower relative mass than otariid pups. However, other predictions do not correspond to empirical findings. In particular, the model does not explain the behavior of large otariids and small phocids. Thus, maternal metabolic requirements alone appear insufficient to explain observed lactation patterns. In the light of our results, we discuss more generally the scope and limitations of optimality models when applied in a comparative framework to a group of related species.     

我国农村作物秸秆资源化调查研究

本文分析了全国秸杆资源化现状和存在问题，探讨秸秆的利用途径和开发价值，对合理开发利用全国的秸秆资源提出了初步建议。     

采用过程方法实施安全检查工作的探讨

将八项质量管理原则之一的过程方法应用于传统安全检查中,通过分析得到安全检查过程的输入、过程实现所需落实的职责和权限以及准则和方法、安全检查过程输出的相关信息,高效地实施安全检查工作,以达到消除隐患及危险有害因素、确保安全生产的目的;采用该方法实施安全检查,在检查的针对性、全面性、整改的彻底性、预防的系统性等方面均较传统的安全检查有所改进,是发现和消除安全隐患的有效方法之一。     

好氧瞬时供料法合成生物可降解塑料的研究进展

聚羟基烷酯(PHAs)作为一种可以完全生物降解的合成塑料替代品而受到越来越多的关注。好氧瞬时供料法由于高的PHAs合成能力及可利用混合菌群(如活性污泥)和有机废弃物合成PHAs显著降低成本而成为目前最具应用前景的PHAs合成技术。文章阐明了好氧瞬时供料法合成PHAs的代谢机制及工艺过程,并就采用该方法合成PHAs的过程中诸多的影响因素进行分析和探讨。     

内蒙古自然保护区生物多样性保护现状

内蒙古经过进多年的建设,已建立了202个自然保护区,由于多年来实行的是以抢救性保护为主的方针和政策,自然保护区建设数量增长较快,随之而来的“重数量轻质量、重建立轻管护”的问题也较为突出。本文仅是一个探索,希望能对自然保护区的生物多样性保护起到一个促进作用,推动自然保护区的可持续发展,文章还欠完善,希望引起同行的兴趣,共同探讨。     

Critical flow-storm approach to total maximum daily load(TMDL) development: an analytical conceptual model

One of the key challenges in the total maximum daily load (TMDL) development process is how to define the critical condition for a receiving waterbody. The main concern in using a continuous simulation approach is the absence of any guarantee that the most critical condition will be captured during the selected representative hydrologic period, given the scarcity of long-term continuous data. The objectives of this paper are to clearly address the critical condition in the TMDL development process and to compare continuous and event-based approaches in defining critical condition during TMDL development for a waterbody impacted by both point and nonpoint source pollution. A practical, event-based critical flow-storm (CFS) approach was developed to explicitly addresses the critical condition as a combination of a low stream flow and a storm event of a selected magnitude, both having certain frequencies of occurrence. This paper illustrated the CFS concept and provided its theoretical basis using a derived analytical conceptual model. The CFS approach clearly defined a critical condition, obtained reasonable results and could be considered as an alternative method in TMDL development.     

Quantitative analysis of CO2 embodiment in international trade: An overview of emerging literatures

The increasing volume of CO₂ embodiment in international trade adds a layer of complexity to environmental policies and has raised arguments on the traditional production based responsibility for CO₂ emissions. In order to help understand the quantity of CO₂ embodiment in trade and its policy implications, this paper gives observations to recently emerging literatures that quantitatively discuss CO₂ embodiment in trade. The analytical approaches share the principle of using input and output modeling but vary dramatically in study boundary and estimation accuracy. The calculations can be roughly categorized into three types: direct quantification of CO₂ embodiments in multiregional trade, direct quantification of CO₂ embodiment in bilateral trade, and indirect analysis by comparing the scenarios with or without trade. The practical estimations strongly rely on trade partner selection and data availability. An obvious imbalance of net CO₂ embodiment in the commodity trade between major developed countries and developing economies as a whole was confirmed by these literatures. Carbon taxes and other possible limitations on CO₂ emissions have been addressed. The consistency across the calculations could be enhanced by systematic analyses in more detail to convince the international community to take binding commitments for the reduction of global CO₂ emissions.     

Emissions corridors for reducing the risk of a collapse of the Atlantic thermohaline circulation

In this paper, we present the integrated assessment model dimrise (dynamic integrated model of regular climate change impacts and singular events). This model is designed to investigate the stability of the Atlantic thermohaline circulation (THC) and to derive related climate policy recommendations. It is written in GAMS and comprises a dynamic model of the THC coupled to a climate model and a global economy model for assessing the monetary cost of climate protection. The THC model is a dynamic four-box interhemispheric extension of the classic Stommel model calibrated against results obtained using the CLIMBER-2 climate model. The reduced-form climate model used to drive the THC model is the ICLIPS multi-gas climate model, which is a computationally efficient, globally aggregated model able to mimic the response of more sophisticated carbon cycle and atmosphere-ocean general circulation models. The THC and climate modules are coupled to a globally aggregated Ramsey-type optimal growth model of the world economy derived from the Nordhaus DICE model. Together, these components create a novel dynamic fully coupled computationally efficient integrated assessment model. Illustrative applications demonstrate that dimrise is able to derive (constrained) economically optimal emissions paths that comply with prescribed bounds on admissible THC weakening imposed in order to avoid an irrevocable breakdown. In addition, emissions corridors are presented which contain all possible emissions paths that do not endanger the stability of the THC and that simultaneously obey restrictions on welfare loss arising from mitigation efforts. The presented results show that, under worst-case conditions, the stability of the THC may be threatened within two decades if global emissions would not deviate from the business-as-usual trajectory.

新苏南模式中应对环境问题的路径选择

苏南模式固有的弊端所导致的＂村村点火、乡乡冒烟＂的经济格局导致了严重的环境问题。随着新苏南模式的诞生,环境问题有所改善,但仍然存在着固有的路径依赖。通过对原因的分析,可以发现,政府、企业与公众的共同参与是解决问题的关键,具体而言：一是转换政府角色,引入市场机制;二是公众主动参与,发展第三组织;三是企业积极参与,发展生态产业。