泥河湾盆地于家沟遗址AMS-14C年代学研究及其考古学意义

于家沟遗址作为泥河湾盆地中唯一具有新旧石器工业过渡的典型遗址,为研究东亚旧石器向新石器时代过渡提供了理想的场所。本文通过于家沟遗址剖面沉积物(厚约550 cm)的加速器质谱法(AMS-~(14)C)年代测定,确定了于家沟剖面的年代跨度为16.19?—?2.43 ka BP,其中旧石器向新石器时代的转化时限为9.35 ka BP。该遗址中发现的最早陶器经同层位地层推测,其年代为13.60 ka BP,是目前中国北方发现的最早陶器。陶器的使用可能改善了古人类的生活条件;大量细石器反映出泥河湾盆地中采猎经济高度繁荣。因此,在晚更新世末期气候开始变暖的背景下陶器和细石器的出现一定程度推动了中国北方旧石器时代向新石器时代的转变。     

Elevated CO2 alters larval proteome and its phosphorylation status in the commercial oyster, Crassostrea hongkongensis

Ocean acidification (OA) is beginning to have noticeable negative impact on calcification rate, shell structure and physiological energy budgeting of several marine organisms; these alter the growth of many economically important shellfish including oysters. Early life stages of oysters may be particularly vulnerable to OA-driven low pH conditions because their shell is made up of the highly soluble form of calcium carbonate (CaCO₃) mineral, aragonite. Our long-term CO₂ perturbation experiment showed that larval shell growth rate of the oyster species Crassostrea hongkongensis was significantly reduced at pH < 7.9 compared to the control (8.2). To gain new insights into the underlying mechanisms of low-pH-induced delays in larval growth, we have examined the effect of pH on the protein expression pattern, including protein phosphorylation status at the pediveliger larval stage. Using two-dimensional electrophoresis and mass spectrometry, we demonstrated that the larval proteome was significantly altered by the two low pH treatments (7.9 and 7.6) compared to the control pH (8.2). Generally, the number of expressed proteins and their phosphorylation level decreased with low pH. Proteins involved in larval energy metabolism and calcification appeared to be down-regulated in response to low pH, whereas cell motility and production of cytoskeletal proteins were increased. This study on larval growth coupled with proteome change is the first step toward the search for novel Protein Expression Signatures indicative of low pH, which may help in understanding the mechanisms involved in low pH tolerance.     

Predicting regional spread of non-native species using oceanographic models: validation and identification of gaps

Predicting spread is a central goal of invasion ecology. Within marine systems, researchers have increasingly made use of oceanographic circulation models to estimate currents and track species dispersal. However, the accuracy of these models for predicting biological patterns, particularly for non-native species, has generally not been validated. Particularly, we wished to examine the ability of models to predict physical and biological processes, which jointly determine the spread of marine larval organisms. We conducted two empirical studies—a recruitment study and a drift card study—along the coast of New England, USA, focusing on two invaders of concern—the European green crab (Carcinus maenas) and the Asian shore crab (Hemigrapsus sanguineus), to explicitly evaluate the ability of oceanographic models to predict patterns of spread. We used data from the large-scale drift card study to validate our ability to capture dispersal patterns driven purely by physical processes. Next, we conducted a recruitment study to evaluate our ability to reproduce patterns of biological dispersal. We were generally capable of reproducing drift cards patterns—suggesting that the physical mechanics in the model were predictive. However, predicted biological patterns were inconsistent—we were able to predict dispersal patterns for H. sanguineus but not for C. maenas. Our results highlight the importance of validating models and suggest that more work is necessary before we can reliably use oceanographic models to predict biological spread of intertidal organisms.     

小流域水质评价方法对比研究

为分析小流域水质评价方法的准确度和适应度,以小安溪流域2017年和2018年的监测数据为基础,利用单因子评价法、综合指数评价法、内梅罗污染指数法和加拿大水质指数法进行水质评价,利用等标水质分析的思想对比了四种方法的评价准确度.评价结果显示:单因子评价法更适合评价水质分布较均匀的流域,内梅罗污染指数法要更为客观一些,加拿...     

环境执法在环保垂改中的基本路径与主要任务

为积极稳妥推进全国省以下环保机构监测监察执法垂直管理制度改革试点工作,本文紧紧围绕《关于省以下环保机构监测监察执法垂直管理制度改革试点工作的指导意见》精神,以环境执法改革为主体主线,从环境执法的总体方向、基本路径、主要任务三个方面进行政策分析解读,给各地在环保垂直管理制度改革试点工作中有效推进环境执法改革,提供改革路径指引和参考。     

Partnerships and governance at the environment–health nexus in Ontario: lessons from five case examples

The move towards partnerships and collaborative governance models has been advocated in global health discussions for many years now. A case example methodology was applied to this study. It was composed of a document review and semi-structured interviews with key informants from five environment and public health partnerships in the province of Ontario, Canada. These case examples highlight the merits and the challenges of diverse partnerships, and the importance of governance and leadership models, scaling up (and out) impact, and cross-cultural communications to these arrangements. Further work is required to articulate situations in which public health partnerships can be strengthened.     

POTENTIAL CLIMATE CHANGE IMPACTS ON MOUNTAIN WATERSHEDS IN THE PACIFIC NORTHWEST1

ABSTRACT: Global climate change due to the buildup of greenhouse gases in the atmosphere has serious potential impacts on water resources in the Pacific Northwest. Climate scenarios produced by general circulation models (GCMs) do not provide enough spatial specificity for studying water resources in mountain watersheds. This study uses dynamical downscaling with a regional climate model (RCM) driven by a GCM to simulate climate change scenarios. The RCM uses a subgrid parameterization of orographic precipitation and land surface cover to simulate surface climate at the spatial scale suitable for the representation of topographic effects over mountainous regions. Numerical experiments have been performed to simulate the present-day climatology and the climate conditions corresponding to a doubling of atmospheric CO₂ concentration. The RCM results indicate an average warming of about 2.5°C, and precipitation generally increases over the Pacific Northwest and decreases over California. These simulations were used to drive a distributed hydrology model of two snow dominated watersheds, the American River and Middle Fork Flathead, in the Pacific Northwest to obtain more detailed estimates of the sensitivity of water resources to climate change. Results show that as more precipitation falls as rain rather than snow in the warmer climate, there is a 60 percent reduction in snowpack and a significant shift in the seasonal pattern of streamflow in the American River. Much less drastic changes are found in the Middle Fork Flathead where snowpack is only reduced by 18 percent and the seasonal pattern of streamflow remains intact. This study shows that the impacts of climate change on water resources are highly region specific. Furthermore, under the specific climate change scenario, the impacts are largely driven by the warming trend rather than the precipitation trend, which is small.