Variation of geochemical risk associated with the use of ophiolitic washing mud as refilling material in a basalt quarry of the Northern Apennine (Italy)

Ophiolitic sequences in Northern Apennines are usually exploited as source of raw material for civil engineering works. Grinding procedures of basalts imply the production of dusts with relatively high concentration of PHES. This paper studied the increase of geochemical risk when washing mud produced at Sasso di Castro quarry site (Tuscany) is reused as rock keeper in a near dismissed quarry and highlighted geochemical fractionation produced on the base of different mineral hardness. Co, Cr, Ni and V concentration measured in washing mud were higher than the limits fixed by the Italian law but compatible with background values. The mobility of these four elements during future weathering processes were estimated by considering the element transfer coefficients and assuming weathered rocks and soils as two different natural analogues of the future state of washing mud. The future concentration was estimated by considering the average lifetime of mineral grains calculated through their dissolution rate, molar volume and grain diameter. The variations of geochemical concentrations were used to estimate the percentage increase of the geochemical risk at the displacement place. After 50 years the associated geochemical risk is still considerably lower than the probability to be damaged by a single landslide event.     

Decisions under uncertainty: a computational framework for quantification of policies addressing infectious disease epidemics

Emerging infectious diseases continue to place a strain on the welfare of the population by decreasing the population’s general health and increasing the burden on public health infrastructure. This paper addresses these issues through the development of a computational framework for modeling and simulating infectious disease outbreaks in a specific geographic region facilitating the quantification of public health policy decisions. Effectively modeling and simulating past epidemics to project current or future disease outbreaks will lead to improved control and intervention policies and disaster preparedness. In this paper, we introduce a computational framework that brings together spatio–temporal geography and population demographics with specific disease pathology in a novel simulation paradigm termed, global stochastic field simulation (GSFS). The primary aim of this simulation paradigm is to facilitate intelligent what-if-analysis in the event of health crisis, such as an influenza pandemic. The dynamics of any epidemic are intrinsically related to a region’s spatio–temporal characteristics and demographic composition and as such, must be considered when developing infectious disease control and intervention strategies. Similarly, comparison of past and current epidemics must include demographic changes into any effective public health policy for control and intervention strategies. GSFS is a hybrid approach to modeling, implicitly combining agent-based modeling with the cellular automata paradigm. Specifically, GSFS is a computational framework that will facilitate the effective identification of risk groups in the population and determine adequate points of control, leading to more effective surveillance and control of infectious diseases epidemics. The analysis of past disease outbreaks in a given population and the projection of current or future epidemics constitutes a significant challenge to Public Health. The corresponding design of computational models and the simulation that facilitates epidemiologists’ understanding of the manifestation of diseases represents a challenge to computer and mathematical sciences.     

Holocene occurrence of Lophodermium piceae, a black spruce needle endophyte and possible paleoindicator of boreal forest health

Holocene occurrences of conifer needle endophytes have not previously been reported. We report the fossil remains of Lophodermium piceae (Fckl.) Hoehn., a fungal endophyte of black spruce (Picea mariana (Mill.) B.S.P.) needles, in macrofossils dating back to 8000 cal yr BP. Spruce budworm head capsules and L. piceae remains were found preceding charcoal layers delineating the transformation of four spruce−moss forest sites to spruce−lichen woodland. As L. piceae is found solely on senescent needles, its increased presence during these transformation periods likely indicates that the forests were in decline due to the spruce budworm (Choristoneura fumiferana (Clem.)) when they burned. Future paleoecological studies incorporating needle fungi observations could be used to investigate the historical occurrence of tree disease and the role of fungi in forest health and decline.     

个旧锡矿区围岩介质成矿地球化学作用

对碳酸盐地层的研究发现，个旧锡矿区围岩介质和地球化学作用对矿床的成因影响很大、联系密切，有明显的成矿控制作用。     

丘北县温浏金成矿区找金前景

根据对矿区地质、矿化(体)展布以及Au、As、Sb、Hg次生晕分析,结合金矿化信息、化探异常组合及矿床共生特征等,认为该区有较好的找金前景。     

A review of geochemical background concepts and an example using data from Poland

One of the most crucial issues of recent environmental sciences is the topic of background concentrations of elements and organic compounds in various abiotic and biotic systems. The relationship between natural and anthropogenically altered concentrations of chemical species is a question that involves many implications in the geosciences, environmental and biological sciences, toxicology, and other related disciplines. This is especially important when interpreting geochemical and biogeochemical anomalies of toxic elements and/or organic compounds in various media. To better understand the potential impact of hazardous substances in the environment, we must become more familiar with their spatial and temporal distribution and with their behavior under different physico-chemical and biotic conditions. This review presents an assessment of the geochemical background concept as used by various authors. Different assumptions and approaches to this topic are presented, including direct, statistical, and integrated methods. Based on the results derived from geochemical and biogeochemical studies performed in selected forest ecosystems of Poland, an integrated method is presented. As a consequence of data processing, a normal distribution of data points was obtained using an iterative 2σ-technique. This method of estimating geochemical background is feasible and can be used for setting environmental quality standards or for studying the impact of anthropogenic pollution sources on the environment.     

Extent of immobilisation of phosphate during aeration of nutrient-rich, anoxic groundwater

Nutrient-rich exfiltrating groundwater may impose a heavy phosphate load on surface water systems. However, iron oxides that bind PO₄ precipitate fast upon oxygenation at neutral pH and PO₄ may also become bound in Ca precipitates following upon pH increase, so load estimates based on conservative behaviour during exfiltration will be overestimates. Aeration experiments using natural groundwater were performed to characterise the immobilisation of PO₄ within one day after aeration started. Groundwaters having a wide variety in composition, were sampled in the coastal lowlands of the Western Netherlands. Three models were considered to describe the fast binding of PO₄ by Fe oxide type phases that form upon the oxygenation of dissolved Fe(II), each based on a different concept. The concepts were surface complexation, solid-solution precipitation and two-mineral precipitation. When the experimental data were compared with model results, all three models were found to be inadequate. Frequently, more immobilisation of PO₄ occurred than could be explained by binding to a Fe oxide type of phase alone. Uptake by Ca phosphates and/or Ca carbonates must additionally have played a role; alternatively, a non-ideal phase consisting of Ca, Fe and PO₄ precipitated upon oxygenation and CO₂ degassing. A predictive multiple regression model with two primary variables that reflect the driving forces for PO₄ immobilisation was deduced that describes immobilisation of phosphate after aeration of anoxic groundwater. The two primary variables are the log value of the groundwater Fe to PO₄ molar ratio and the saturation state for hydroxyapatite after the CO₂ degassing of groundwater. The model is useful for calculating the PO₄ load of surface water from exfiltration groundwater, taking into account fast immobilisation (<1 day) during exfiltration.     

SARS空间传播模式及其在疫情监控信息系统设计中的应用

在中国控制SARS(Severe Acute Respiratory Syndrome)疫情扩散与蔓延的大量科学实践活动基础上，从人地系统科学的理论和观点出发，提出了各种致病因子在人地互动过程中转移路径的逻辑模型，进而又提出了控制SARS疫情发展的人地互动逻辑模型。从后一个模型出发，把中国SARS疫情的发展规律归纳为5种传播模式，即异类病毒转移传播模式、家庭和社区接触传播模式、医院和门诊感染传播模式、市内随机扩散传播模式和飞点跳跃跨区传播模式。其中，跨区传播模式的影响最广泛、危害最巨大、控制起来最艰巨、复杂，是建立中国突发公共卫生事件应急机制、增强应急能力需要解决的主要问题和关键内容。为此，作者对中国的疫情控制应急机制及其实现提出了一些具体的看法和建议，包括对现有疫情系统进行技术改造和创新的建议，在全新运作机制和高技术基础上建立应急疫情监测控制信息系统的概念结构等内容。     

河南洛阳龙门石窟溶蚀病害机理的研究

河南洛阳龙门石窟位于碳酸盐岩体中,易于溶蚀。近年来,石窟区伊河水以及雨水中Cl-、SO2-3等有害离子明显增加,加剧了石窟的岩溶病害。在龙门石窟溶蚀现4、NO-4、NH+状调查的基础上,从岩溶的空间分布规律、岩体结构渗水连通网络和微观结构等方面探讨了溶蚀病害的机理。提出治理龙门石窟溶蚀病害的根本途径是治水,应该通过裂隙注浆,设置地表防渗铺盖和地表排水系统等止水措施,杜绝雨水入渗到洞窟内溶蚀雕刻品。此外,对现有岩溶沉淀物可以采用软化剥离的方法进行人工清除,对雕刻品上的溶洞、溶沟等可采用石窟原岩岩屑调制的修复砂浆进行充填修复。     

镇康章龙原生-红土型金矿地质

章龙金矿既有原生型、又有红土型的共生金矿床。矿床受构造、地层、围岩制约。红土型金矿还受地形、残坡积层、风化壳发育程度影响。