Assessing national livestock populations for the production of methane emission inventories

In an effort to accurately assess national methane (CH₄) production levels, many African countries are producing inventories of their national livestock populations. Conducting accurate livestock surveys is an expensive and time-consuming process, but is necessary because the most readily available data on livestock production are often incomplete or unsatisfactory. This paper looks at practical approaches to collecting data on livestock production and on the reproductive parameters for livestock, with special reference to African pastoralist populations, and makes qualified recommendations as to how inventory teams might be able to produce more accurate assessments of their total livestock populations. The methodology used during Nigeria's National Livestock Census (1990–92) serves as a basis for a discussion of the issues.     

Accelerated fractionation of heavy metals in contaminated soils and sediments using rotating coiled columns

A new approach to performing an accelerated sequential extraction of trace elements from solid samples has been proposed. It has been shown that rotating coiled columns (RCC) earlier used in counter-current chromatography can be successfully applied to the dynamic leaching of heavy metals from soils and sediments. A solid sample was retained in the rotating column as the stationary phase under the action of centrifugal forces while different eluents (aqueous solutions of complexing reagents, mineral salts and acids) were continuously pumped through. The procedure developed is time saving and requires only 4-5 h instead of the several days needed for traditional sequential extraction (TSE), complete automation being possible. Losses of solid sample are minimal. In most cases the recoveries of readily bioavailable and leachable forms of Pb, Zn, and Cd are higher, if a dynamic extraction in RCC is used. Since naturally occurring processes are always dynamic, continuous extraction in RCC may help to estimate the contents of leachable forms and their potential risk for the environment more correctly than batch TSE. The Kersten-Foerstner and McLaren-Crawford leaching schemes have been compared, the former has been found to be preferable.     

Copper, Copper Mining Effluents and Grazing as Potential Determinants of Algal Abundance and Diversity in Northern Chile

We experimentally tested threealternative hypotheses to explain the low algaldiversity and abundance in an intertidal zonereceiving the effluents of the copper mine El Salvadorin northern Chile. Our results demonstrated thatalgae were able to grow at the levels of dissolvedcopper detected in coastal waters of the area. Duringthe assays, growth and regeneration in several red,green and brown adult algae and juvenile Lessonia nigrescens were normal at copper levels of150 g L^-1 or, in some cases, higher. Wealso found that the coastal sea water mixed with theeffluent was not lethal to algae, although in somecases minor effects on growth were detected. Theseresults indicate that today's low algal diversity andabundance can not be explained by the current copperlevels in the area nor by the effect of the effluent.Exclusion of grazers, however, resulted in a fastcolonization by various algal species. This, togetherwith atypically high grazer density at the areas underthe influence of the effluent, strongly suggests thatherbivory, a factor not directly related to the miningoperation, is likely to be responsible for the lowalgal diversity and abundance in the studied locality.     

西印度洋地区海草生态系统

海草是海洋被子植物,广泛分布在温带和热带的海岸带水域,是地球上水生生态系统中最具生产力的生物之一.     

Verbreitung von Arginase in Lungengewebe von Säugetieren

The Science of Nature -     

辐射化学在环境激素研究中的应用

环境激素对地球生态系统带来严重威胁.大量难降解环境激素(如多氯联苯、二噁英)危害全球脆弱的生态环境,其直接后果之一就是人类乳腺癌等恶性疾病发病率急剧上升.因此,当今世界各国均十分重视环境激素的环境生物学机理研究.辐射化学作为一门高新技术,在环境激素污染物处理、降解机理与生命科学研究等方面可发挥重要作用,例如:同步辐射可用于直接观测溶液口的雌激素受体ER真实结构,脉冲辐解、激光光解和电子自旋共振用于研究环境激素活性瞬态粒子动力学等等.     

Respiratory health assessment and exposure to polycyclic aromatic hydrocarbons in Mexican indigenous population

Environmental Science and Pollution Research - Indoor air pollution is an important risk factor for the generation of lung diseases in developing countries. The indigenous population is...     

Solid-waste management in the rural area of BRAZIL: a case study in Quilombola communities

Although there has been a worldwide growing concern regarding solid-waste management, the rural area has been left behind on this matter. It is common knowledge that the lack of waste management is very detrimental to the environment and impact seriously the public health. Therefore, the aim of this work is to contribute to the decision-making process regarding waste management in the rural area by proposing a new methodology using the combination of risk analysis and complementary sustainability criteria. The proposed methodology was demonstrated through a case study in the State of Mato Grosso do Sul, Brazil. A field survey was performed to define the current scenarios and three new scenarios were proposed. The risk analysis showed that the major risk to which residents are vulnerable to is the appearance of vectors that can cause various types of diseases. Besides that, only 30% of rural Quilombola communities of Mato Grosso do Sul have waste collection and the predominant scenario is the burning of dry waste and use of organic waste for animal feeding. Using the complementary relevant criteria, the most suitable scenario do the studied communities would be the combination of household composting and source separation of dry waste. The proposed methodology can be easily applied to other rural regions seeking for sustainable waste management systems.     

Two roads to effectiveness: CEO feedback seeking,vision articulation,and firm performance

Humble leadership is attracting increased scholarly attention, but little is known about its effects when used in conjunction with less humble leadership behaviors that rely on a perception of the leader as confident and charismatic. This study contrasts the effects on top management team (TMT) potency and organizational performance of a more humble (feedback seeking) and a less humble (vision) CEO leader behavior. We hypothesize that CEO feedback seeking increases TMT potency and firm performance by communicating to TMT members that the organization values their input and encouraging their own feedback seeking, whereas CEO vision articulation influences these outcomes by fostering greater clarity about the firm's direction, and an enhanced ability to coordinate efforts within the TMT. CEOs who have not developed a vision can achieve a similar positive impact on TMT potency and firm performance by seeking feedback. In a sample of CEOs and TMT members from 65 firms, both CEO feedback seeking and vision articulation exhibit positive direct relationships with firm performance. However, only feedback seeking displays an indirect effect on performance via TMT potency. Finally, CEO feedback seeking has its strongest effects on firm performance and TMT potency for CEOs who are not seen as having a vision.     

Using a noise monitoring station in a small quarry located in an urban area

Mining plays an important role in Brazilian exports. On the other hand, large urban centers like São Paulo, with approximately 21 million inhabitants, also demand an increasing domestic consumption of natural resources, such as construction aggregate. There are many quarries located in the surroundings of urban centers in Brazil, competing with the growth of urbanized areas. Such proximity leads to a series of conflicts involving quarries and surrounding communities, where the increase in noise levels is highlighted. Operations in quarries, in general, are intermittent. Noisier equipment, such as drilling rigs and primary crushers, operates only a few hours during the day, while other operations, such as screening and secondary and tertiary crushing, are more constant. This paper presents a study carried out in a quarry located near São Paulo, where in addition to conventional short term noise measurements at surrounding receptors, one noise monitoring station was installed, allowing to identify the noisiest moments during the quarry operating time. Through data transmitted by wireless technology, it was possible to follow the noise variations emitted from mining activities in real time and observe the noisiest events that were recorded for events that exceeded the established standards. A mobile application associated to this monitoring station facilitated the quarry’s manager and employees to access immediately the monitoring information. Therefore, by using this system, it was possible to evaluate the effectiveness of noise reduction measures already taken and indicate what steps still need to be held.