红枫湖、百花湖水中溶解有机物分子量分布特征及环境地球化学意义

溶解有机物（dissolved organio matter， DOM）通常是指能够通过0.45μm滤膜的有机物质。0.45μm的定义是根据传统的过滤滤膜直径来划分的，不是一个绝对的定义。DOM在水环境中起着重要的作用，它是水环境中重要的配位体和吸附载体。DOM在水化学和生态环境中的重要作用，主要表现在它不仅可以和基本的金属离子和有机化合物结合，还可以与毒性金属离子和除草剂、杀虫剂结合（wershow ond Goldberg，1972）。湖泊水中DoM的浓度及物理化学性质能够影响水生态环境的结构及初级生产力。溶解有机物按元素组成来分，主要含有C、O、H、N、P、S以及灰分。按重量计算，其中C占总有机物的50％，其次是O（科O％）、H（一5％）、N（0.5～6.5％）、P（＜1.0％）、S（＜1.0％）和灰分（1.2-5.0％）（Thurman，1985）。DOM一般由多种有机化合物组成，其中腐殖物质是溶解有机质的主要组成部分，一般占有机质总量的50-80％。目前通常可人为地将腐殖物质划分为胡敏素、胡敏酸和富里酸（Aiken et oL，1 985）。其余的非腐殖类物质主要包括碳水化合物、氨基酸、叶绿素、藻类分泌物、酚酮类化合物、脂肪酸和亲水性有机酸等（Thurman，1985）a在水环境中一些金属离子和微量元素通常和DOM相结合，而这些元素的作用和在水中的迁移都受DoM的分子量分布的影响（chiou etal．，1986）。 DOM的分子量及其分布是指示水质量的一个重要参数，同时在水处理过程中对于研究DOM的去处效率有重要作用（vuorio et oL，1998）。具有不同分子量分布的DOM与金属的络合能力也不同，则它们对金属的生物有效性的作用就不同（wuetal．，2002）。分子量变化的程度可以进一步理解DOM的自然形成过程，也可以在弓！用水处理过程中优化腐殖质的去除过程。红枫湖和百花湖是贵州地区两个人工水库，通过对两湖水文条件的测量，探讨了影响DOM分子量及分布变化的环境因素，包括溶解氧的含量、水体温度、pH值、叶绿素。的含量、光照强度、藻类生长情况、生物活动等，以及溶解有机物的来源，人为污染情况等。本文采样高效体积排阻色谱法（High PerformanceSizeExclusion cbromatograP场，HPsEC）测量了红枫湖、百花湖水中的DOM的含量及分子量分布，得出了以下几点认识：1、选择HPsEC实验的最佳条件：0.03M NaCl和0.002的磷酸盐缓冲液作为流动相，pH为6.8，离子强度为0．034mol几，紫外检测波长为254nm。2、红枫湖、百花湖水中DOM主要以分子量小于3500Da的组分为主，占总溶解有机物的90％以上。根据洗脱曲线的峰面积，可以把DOM分为3个不同 分子量的组分，其中大分子量组分（MW＞2000Da）的含量占总DOM的35％一68％；中等分子量组分（Z000Da＞MW>1000Da）的含量为27％-57％；小分子量组分（MW＜1000Da）占总DOM的3％一31％。 3、红枫湖、百花湖水中Doc含量受气候条件的影响。丰水期，水体上部DOC含量较大，下部较小‘平水期和枯水期，上下水体中DOC含量一致。各组分DOc含量变化与总DOC含量变化相似。DOC含量也表现出明显的季节性变化特征。丰水期DOC含量较高，而在平水期和枯水期含量较低。红枫湖和百花湖二者之间DOC含量没有明显的差别。4、红枫湖、百花湖水中DOM平均分子量也受气候条件的影响。丰水期，随深度的增大，DoM平均分子量增大；平水期和枯水期，上下水体DOM平均分子量一致。DO入左的季节性变化与DOC相反，丰水期，DOM平均分子量偏低；而在平水期和枯水期，DOM平均分子量偏高。5、重均分子量和数均分子量虽然变化趋势相似，但是它们的变化幅度不同，所以多分散系数也会发生变化。总的来说，在水体上部多分散系数偏大，水体下部偏小。丰水期多分散系数较大，平水期和枯水期多分散系数较小。6、随着气候条件的变化，各分子量组分的DOM含量及DOC浓度也在发生变化。大分子量组分随深度而增大，而中等和小分子量组分随深度而减小。丰水期，中等和小分子量组分含量较多，而大分子量组分较少；平水期和枯水期，大分子量组分含量较多，中等和小分子量组分含量较少。

Shape-Time Photography

We introduce a new method to describe, in a single image, changes in shape over time. We acquire both range and image information with a stationary stereo camera. From the pictures taken, we display a composite image consisting of the image data from the surface closest to the camera at every pixel. This reveals the 3-d relationships over time by easy-to-interpret occlusion relationships in the composite image. We call the composite a shape-time photograph. Small errors in depth measurements cause artifacts in the shape-time images. We correct most of these using a Markov network to estimate the most probable front surface, taking into account the depth measurements, their uncertainties, and layer continuity assumptions.

(Semi-)Predictive Discretization During Model Selection

In this paper, we present an approach to discretizing multivariate continuous data while learning the structure of a graphical model. We derive the joint scoring function from the principle of predictive accuracy, which inherently ensures the optimal trade-off between goodness of fit and model complexity (including the number of discretization levels). Using the so-called finest grid implied by the data, our scoring function depends only on the number of data points in the various discretization levels. Not only can it be computed efficiently, but it is also independent of the metric used in the continuous space. Our experiments with gene expression data show that discretization plays a crucial role regarding the resulting network structure.

PROTRACTED HYPOFRACTIONATED RADIOTHERAPY for GRAVES' OPHTHALMOPATHY: A PILOT STUDY of CLINICAL and RADIOLOGIC RESPONSE

Purpose: To evaluate the clinical and radiologic response of patients with Graves' ophthalmopathy given low-dose orbital radiotherapy (RT) with a protracted fractionation.Methods and Materials: Eighteen patients (36 orbits) received orbital RT with a total dose of 10 Gy, fractionated in 1 Gy once a week over 10 weeks. of these, 9 patients received steroid therapy as well. Patients were evaluated clinically and radiologically at 6 months after treatment. Clinical response assessment was carried out using three criteria: by physical examination, by a modified clinical activity score, and by a verbal questionnaire considering the 10 most common signs and symptoms of the disease. Radiologic response was assessed by magnetic resonance imaging.Results: Improvement in ocular pain, palpebral edema, visual acuity, and ocular motility was observed in all patients. Significant decrease in symptoms such as tearing (p < 0.001) diplopia (p = 0.008), conjunctival hyperemia (p = 0.002), and ocular grittiness (p = 0.031) also occurred. Magnetic resonance imaging showed decrease in ocular muscle thickness and in the intensity of the T2 sequence signal in the majority of patients. Treatments were well tolerated, and to date no complications from treatment have been observed. There was no statistical difference in clinical and radiologic response between patients receiving RT alone and those receiving RT plus steroid therapy.Conclusion: RT delivered in at a low dose and in a protracted scheme should be considered as a useful therapeutic option for patients with Graves' ophthalmopathy. (C) 2012 Elsevier Inc.

Accelerated partial irradiation for breast cancer: Systematic review and meta-analysis of 8653 women in eight randomized trials

Background and purpose: Accelerated partial breast irradiation (APBI) is the strategy that allows adjuvant treatment delivery in a shorter period of time in smaller volumes. This study was undertaken to assess the effectiveness and outcomes of APBI in breast cancer compared with whole-breast irradiation (WBI). Material and methods: Systematic review and meta-analysis of randomized controlled trials of WBI versus APBI. Two authors independently selected and assessed the studies regarding eligibility criteria. Results: Eight studies were selected. A total of 8653 patients were randomly assigned for WBI versus APBI. Six studies reported local recurrence outcomes. Two studies were matched in 5 years and only one study for different time of follow-up. Meta-analysis of two trials assessing 1407 participants showed significant difference in the WBI versus APBI group regarding the 5-year local recurrence rate (HR = 4.54, 95% CI: 1.78-11.61, p = 0.002). Significant difference in favor of WBI for different follow-up times was also found. No differences in nodal recurrence, systemic recurrence, overall survival and mortality rates were observed. Conclusions: APBI is associated with higher local recurrence compared to WBI without compromising other clinical outcomes. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

Volumetric consequences of particle loss by grading entropy.

Chemical and biological processes, such as dissolution in gypsiferous sands and biodegradation in waste refuse, result in mass or particle loss, which in turn lead to changes in solid and void phase volumes and grading. Data on phase volume and grading changes have been obtained from oedometric dissolution tests on sand–salt mixtures. Phase volume changes are defined by a (dissolution-induced) void volume change parameter (Λ). Grading changes are interpreted using grading entropy coordinates, which allow a grading curve to be depicted as a single data point and changes in grading as a vector quantity rather than a family of distribution curves. By combining Λ contours with pre- to post-dissolution grading entropy coordinate paths, an innovative interpretation of the volumetric consequences of particle loss is obtained. Paths associated with small soluble particles, the loss of which triggers relatively little settlement but large increase in void ratio, track parallel to the Λ contours. Paths associated with the loss of larger particles, which can destabilise the sand skeleton, tend to track across the Λ contours.

Determinants of port centrality in maritime container transportation.

This paper adapts Freeman’s measures of degree, closeness and betweenness centrality and applies them to assessing: port centrality in relation to direct connectivity; accessibility to all ports in the network (direct and indirect routes) and; as an intermediary between other ports. An additional parameter added to the formulae ensures that the relative importance of available shipping capacity and foreland market coverage are also accounted for. Validation of this adapted measure is provided by the results obtained from an empirical application. These reveal that foreland market coverage exerts a particularly strong influence on a port’s demand and closeness centrality

Statistical Evaluation of the Predictive Toxicology Challenge 2000-2001

Toivonen, H., Srinivasan, A., King, R. D., Kramer, S. and Helma, C. (2003) Statistical Evaluation of the Predictive Toxicology Challenge 2000-2001. Bioinformatics 19: 1183-1193

From epistemic origins to journal impact factors: what do citations tell us?

Urquhart, C. (2006). From epistemic origins to journal impact factors: what do citations tell us? International Journal of Nursing Studies, 43(1), 1-2.

The heavy metal content of skeletons from an ancient metalliferous polluted area in southern Jordan with particular reerence to bioaccumulation and human health

Pyatt, F.B., Pyatt, A.J., Walker, C., Sheen, T., Grattan, J.P, The heavy metal content of skeletons from an ancient metalliferous polluted area in southern Jordan with particular reerence to bioaccumulation and human health, Ecotoxicology & Environmental Safety 60, 13th August 2003, 295-300

Drainage induced convection rolls in foams

Hutzler, S., Cox, S.J., Janiaud, E. and Weaire, D. (2007) Drainage induced convection rolls in foams. Colloids and Surfaces A: Physicochemical and Engineering Aspects Volume 309, Issues 1-3, 1 November 2007, Pages 33-37 A Collection of Papers Presented at the 6th Eufoam Conference, Potsdam, Germany, 2-6 July, 2006 Sponsorship: European Space Agency (14914/02/NL/SH, 14308/00/NL/SG) (AO-99-031) CCN 002 MAP Project AO-99-075); Science Foundation Ireland (RFP 05/RFP/PHY0016); Royal Society; UWA Learned Societies.

Steady drainage in emulsions: corrections for surface Plateau borders and a model for high aqueous volume fraction

Peron, N., Cox, S.J., Hutzler, S. and Weaire, D. (2007) Steady drainage in emulsions: corrections for surface Plateau borders and a model for high aqueous volume fraction. The European Physical Journal E - Soft Matter. 22: 341-351. Sponsorship: This research was supported by the European Space Agency (14914/02/NL/SH, 14308/00/NL/SG) (AO-99-031) CCN 002 MAP Project AO-99-075) and Science Foundation Ireland (RFP 05/RFP/PHY0016). SJC acknowledges support from EPSRC (EP/D071127/1).

A viscous froth model for dry foams in the Surface Evolver

Cox, S.J. (2005) A Viscous Froth Model for Dry Foams in the Surface Evolver. Coll. Surf. A 263:81-89. Sponsorship: Partial support from both the Ulysses France?Ireland Exchange Scheme and the European Space Agency, Contract 14308/00/NL/SH (AO-99-031) CCN 002 MAP Project AO-99-075.

Developmental Learning for Autonomous Robots

M.H. Lee, Q. Meng and F. Chao, 'Developmental Learning for Autonomous Robots', Robotics and Autonomous Systems, 55(9), pp 750-759, 2007.

The impact of short duration, high intensity exercise on cardiac troponin release

The aim of this study was to assess the appearance of cardiac troponins (cTnI and/or cTnT) after a short bout (30 s) of ‘all-out’ intense exercise and to determine the stability of any exercise-related cTnI release in response to repeated bouts of high intensity exercise separated by 7 days recovery. Eighteen apparently healthy, physically active, male university students completed two all-out 30 s cycle sprint, separated by 7 days. cTnI, blood lactate and catecholamine concentrations were measured before, immediately after and 24 h after each bout. Cycle performance, heart rate and blood pressure responses to exercise were also recorded. Cycle performance was modestly elevated in the second trial [6·5% increase in peak power output (PPO)]; there was no difference in the cardiovascular, lactate or catecholamine response to the two cycle trials. cTnI was not significantly elevated from baseline through recovery (Trial 1: 0·06 ± 0·04 ng ml−1, 0·05 ± 0·04 ng ml−1, 0·03 ± 0·02 ng ml−1; Trial 2: 0·02 ± 0·04 ng ml−1, 0·04 ± 0·03 ng ml−1, 0·05 ± 0·06 ng ml−1) in either trial. Very small within subject changes were not significantly correlated between the two trials (r = 0·06; P>0·05). Subsequently, short duration, high intensity exercise does not elicit a clinically relevant response in cTnI and any small alterations likely reflect the underlying biological variability of cTnI measurement within the participants.