An evaluation of the interaction of morning residual layer and afternoon mixed layer ozone in Houston using ozonesonde data

The Tropospheric Ozone Pollution Project (TOPP) launched >220 ozonesondes in Houston (July 2004–June 2008) providing examples of pollution transported into, re-circulated within, and exported from the Houston area. Fifty-one launches occurred during the Texas Air Quality Study (TexAQS) II and the summer portion of IONS-06 (INTEX [Intercontinental Transport Experiment] Ozonesonde Network Study). On 11 days during TexAQS II and on 8 other occasions, ozonesondes were launched both at dawn and in the afternoon. Analysis of these “intensive” launch sequences shows that morning residual layer (RL) ozone concentrations ([O₃]) explained 60–70% of the variability found in the afternoon mixed layer (ML). Furthermore, maximum RL [O₃] is nearly identical to the mean ML [O₃] from the previous afternoon (morning minus afternoon = ?1.6 ± 8.4 ppbv). During TexAQS II, mean [O₃] below 1.3 km (the mean ML height from ozonesonde data) increased from 37 ± 22 ppbv in the morning to 74 ± 18 ppbv in the afternoon, suggesting an average net local daily O₃ production of ～500–900 tons over the metropolitan Houston area.     

Natural disasters and older US adults with disabilities: implications for evacuation

We analysed 2003 and 2004 Behavioral Risk Factor Surveillance System (BRFSS) data from New Orleans-Metairie-Kenner, LA to produce estimates of the number of community dwelling people aged 65 years or older with a disability and requiring special equipment.(4) Approximately, 47,840 (31.6 per cent) older adults with a disability and 24,938 (16.6 per cent) older adults requiring the use of special equipment were community dwelling and might require assistance to evacuate or a shelter that could accommodate special equipment. Older adults who need special equipment were likely to be female, unmarried and white, and to rate their health as fair or poor. Personnel who plan and prepare for evacuations and temporary shelter during disasters need baseline information on the number of older adults with a disability or who require special equipment. A surveillance system, such as the BRFSS, gathers information that planners can use to prepare for and to deliver services.     

National contributions to global ecosystem values

Current conservation templates prioritize biogeographic regions with high intensity ecosystem values, such as exceptional species richness or threat. Intensity-based targets are an important consideration in global efforts, but they do not capture all available opportunities to conserve ecosystem values, including those that accrue in low intensity over large areas. We assess six globally-significant ecosystem values—intact wilderness, freshwater availability, productive marine environments, breeding habitat for migratory wildlife, soil carbon storage, and latitudinal potential for range shift in the face of climate change—to highlight opportunities for high-impact broadly-distributed contributions to global conservation. Nations can serve as a cohesive block of policy that can profoundly influence conservation outcomes. Contributions to global ecosystem values that exceed what is predicted by a nation's area alone, can give rise to countries with the capacity to act as ‘conservation superpowers’, such as Canada and Russia. For these conservation superpowers, a relatively small number of national policies can have environmental repercussions for the rest of the world.     

Riparian plant material inputs to the Murray River, Australia: composition, reactivity, and role of nutrients

By changing riparian plants from Eucalypts to pasture and exotic deciduous trees, modern development has altered the type of carbon assimilated by Australian rivers. To investigate influences of plant litter substrates on biochemical oxygen demand, plant materials entering the Murray River were analyzed for their composition and mineralization potential. Plant materials were distinguished compositionally by two principal components, structural carbon and macronutrients, as: (i) Eucalyptus leaves, (ii) Eucalyptus bark and Casuarina cunninghamiana seed cone, (iii) grasses, (iv) macrophytes, (v) aquatic herbs, (vi) non-eucalypt leaf (Salix, Casuarina, Acacia). Ratios of C/P (1879-14524) and C/N (65-267) were relatively high in Eucalyptus bark, while mean N/P (7-60) ratios were similar among plant materials. Terrestrial weathering increased C/P and C/N ratios, while N/P ratios remained similar, due to greater loss of N and P relative to C. Aerobic decay experiments showed that nutrient supplementation accelerated decay of all organic substrates, except for grasses that decayed efficiently without supplementation. Aquatic herbs also had substantial carbon availability, macrophytes and non-eucalypt leaves had intermediate carbon availability, while eucalypt leaf and bark had intermediate to low carbon availabilities. Because biochemical oxygen demand varies with organic substrates sampled from the Murray River, and also with soluble nutrient availability, it is plausible that that modern changes to riverine plant communities and land use have influenced the biogeochemistry of this river toward faster, and more complete, processing of allochthonous carbon.     

Fe-Al改性硅藻土与CaO配施改良Cd污染土壤

以人工模拟Cd污染土壤为研究对象,以Fe-Al改性硅藻土和CaO为原料制备组配改良剂,通过土壤培养试验研究了Fe-Al改性硅藻土与CaO不同配比对组配改良剂改良Cd污染土壤效果的影响.结果表明,向Cd污染土壤施加Fe-Al改性硅藻土与CaO以不同配比所制得组配改良剂对土壤Cd形态、pH值、CEC值、OM值、含水率、有效氮、速效磷、有效钾均产生了积极的影响.当Fe-Al改性硅藻土与CaO的配比为1：6时,土壤可交换态Cd含量较空白对照降低了74.67%,较单一施加Fe-Al改性硅藻土和CaO分别降低了64.63%和7.87%,与对照相比,土壤pH值提升了0.45,土壤CEC提升了69.78%,土壤有效氮、速效磷分别提升了28.57%、70.85%.Fe-Al改性硅藻土与CaO配施能有效控制土壤Cd污染,同时还可有效改善土壤耕作性能.     

Divergence of carbon dioxide fluxes in different trophic areas of Taihu Lake,China

IntroductionCarbondioxide(CO2 )isaprincipalgreenhousegasandthereforetheirair waterexchangesareimportantproblemsinterrestrialecosystemsforclimatechangestudy(Frankignoulle ,1 998;Chimel,2 0 0 1 ) .ThedirectionofCO2 gasexchange(evasionorinvasion)isdependentonthedirectionoftheCO2concentrationgradientbetweentheairandthesurfacewater;themagnitudeoftheexchangedependsadditionallyonthegasexchangecoefficient,k.Alloflakesinland ,withitssmallareabutlargeatmosphericCO2 fluxrange ,playanimportantroleinev…     

On the communicative significance of whistles in wild killer whales (Orcinus orca)

Killer whales (Orcinus orca) use pulsed calls and whistles in underwater communication. Unlike pulsed calls, whistles have received little study and thus their function is poorly known. In this study, whistle activities of groups of individually known killer whales were compared quantitatively across behavioural categories. Acoustic recordings and simultaneous behavioural observations were made of northern resident killer whales off Vancouver Island in 1996 and 1997. Whistles were produced at greater rates than discrete calls during close-range behavioural activities than during long-range activities. They were the predominant sound-type recorded during socializing. The number of whistles per animal per minute was significantly higher during close-range behavioural activities than during long-range activities. Evidently, whistles play an important role in the close-range acoustic communication in northern resident killer whales.     

含硅熔渣对水稻养分吸收及产量的影响

采用盆栽试验方法，研究了不同含硅熔渣对水稻养分的吸收和产量的影响，结果表明，在施用氮、磷、钾肥的基础上，增施不同类型的含硅熔渣，可提高水稻中硅和磷的含量，降低根系、茎叶和籽粒中的氮、钾含量，增加水稻对氮、磷、钾、硅的总吸收量。不同含硅熔渣的增产效果差异较大，增产最显著的是铁渣和黄磷炉渣，分别比对照增产43．4％和31．6％，施用含硅熔渣的各处理比对照平均增产19．1％，各处理间的产量经方差分析和多重比较达显著或极显著差异水平。扩散方程、Elovich方程和多项式方程均能很好地描述水稻生长期内水稻对N、P、K、Si的吸收过程，尤以多项式方程拟合最佳。     

Nitrogen fertilizers: meeting contemporary challenges

At 81.7 million tonnes (Mt), commercial fertilizer nitrogen (N) accounts for approximately half of all N reaching global croplands today and supplies basic food needs for at least 40% of the population. The challenge is to continue to help meet that need while minimizing the risk of negative environmental impacts through improved N-use efficiency. Fertilizer-N efficiency on corn in the US has increased more than 30% over the last 20 years, but additional progress can be made for corn and other crops. Current N efficiency and productivity are generally lower in most of Asia than in North America, but they are improving. The fertilizer industry recognizes its crucial role in meeting basic human needs, now and in the future. It stands ready to meet the challenge of adopting new practices and technologies that will allow it to do so with greater efficiency and in a way that not only sustains life, but also sustains the quality of life.