Nitrous oxide emissions from irrigated cotton soils of northern Australia

An automated gas sampling methodology has been used to estimate nitrous oxide (N2O) emissions from heavy black clay soil in northern Australia where split applications of urea were applied to furrow irrigated cotton. Nitrous oxide emissions from the beds were 643 g N/ha over the 188 day measurement period (after planting), whilst the N2O emissions from the furrows were significantly higher at 967 g N/ha. The DNDC model was used to develop a full season simulation of N2O and N2 emissions. Seasonal N2O emissions were equivalent to 0.83% of applied N, with total gaseous N losses (excluding NH3) estimated to be 16% of the applied N.

Carbon pools and fluxes along an environmental gradient in northern Arizona

Carbon pools and fluxes were quantified along an environmental gradient in northern Arizona. Data are presented on vegetation, litter, and soil C pools and soil CO2 fluxes from ecosystems ranging from shrub-steppe through woodlands to coniferous forest and the ecotones in between. Carbon pool sizes and fluxes in these semiarid ecosystems vary with temperature and precipitation and are strongly influenced by canopy cover. Ecosystem respiration is approximately 50 percent greater in the more mesic, forest environment than in the dry shrub-steppe environment. Soil respiration rates within a site vary seasonally with temperature but appear to be constrained by low soil moisture during dry summer months, when approximately 75% of total annual soil respiration occurs. Total annual amount of CO2 respired across all sites is positively correlated with annual precipitation and negatively correlated with temperature. Results suggest that changes in the amount and periodicity of precipitation will have a greater effect on C pools and fluxes than will changes in temperature :in the semiarid Southwestern United States.

Examination of relationships between urban form, household activities, and time allocation in the Atlanta Metropolitan Region

A substantial body of research is focused on understanding the relationships between socio-demographics, land-use characteristics, and mode specific attributes on travel mode choice and time-use patterns. Residential and commercial densities, inter-mixing of land uses, and route directness in conjunction with transportation performance characteristics interact to influence accessibility to destinations as well as time spent traveling and engaging in activities. This study uniquely examines the activity durations undertaken for out-of-home subsistence; maintenance, and discretionary activities. Also examined are total tour durations (summing all activity categories within a tour). Cross-sectional activities are obtained from household activity travel survey data from the Atlanta Metropolitan Region. Time durations allocated to weekdays and weekends are compared. The censoring and endogeneity between activity categories and within individuals are captured using multiple equations Tobit models. The analysis and modeling reveal that land-use characteristics such as net residential density and the number of commercial parcels within a kilometer of a residence are associated with differences in weekday and weekend time-use allocations. Household type and structure are significant predictors across the three activity categories, but not for overall travel times. Tour characteristics such as time-of-day and primary travel mode of the tours also affect traveler's out-of-home activity-tour time-use patterns.

Infant and young child feeding indicators and determinants of poor feeding practices in India : secondary data analysis of National Family Health Survey 2005–06

Background: In India, poor feeding practices in early childhood contribute to the burden of malnutrition and infant and child mortality. Objective. To estimate infant and young child feeding indicators and determinants of selected feeding practices in India. Methods: The sample consisted of 20,108 children aged 0 to 23 months from the National Family Health Survey India 2005–06. Selected indicators were examined against a set of variables using univariate and multivariate analyses. Results: Only 23.5% of mothers initiated breastfeeding within the first hour after birth, 99.2% had ever breastfed their infant, 89.8% were currently breastfeeding, and 14.8% were currently bottle-feeding. Among infants under 6 months of age, 46.4% were exclusively breastfed, and 56.7% of those aged 6 to 9 months received complementary foods. The risk factors for not exclusively breastfeeding were higher household wealth index quintiles (OR for richest = 2.03), delivery in a health facility (OR = 1.35), and living in the Northern region. Higher numbers of antenatal care visits were associated with increased rates of exclusive breastfeeding (OR for ≥ 7 antenatal visits = 0.58). The rates of timely initiation of breastfeeding were higher among women who were better educated (OR for secondary education or above = 0.79), were working (OR = 0.79), made more antenatal clinic visits (OR for ≥ 7 antenatal visits = 0.48), and were exposed to the radio (OR = 0.76). The rates were lower in women who were delivered by cesarean section (OR = 2.52). The risk factors for bottle-feeding included cesarean delivery (OR = 1.44), higher household wealth index quintiles (OR = 3.06), working by the mother (OR=1.29), higher maternal education level (OR=1.32), urban residence (OR=1.46), and absence of postnatal examination (OR=1.24). The rates of timely complementary feeding were higher for mothers who had more antenatal visits (OR=0.57), and for those who watched television (OR=0.75). Conclusions: Revitalization of the Baby Friendly Hospital Initiative in health facilities is recommended. Targeted interventions may be necessary to improve infant feeding practices in mothers who reside in urban areas, are more educated, and are from wealthier households.

The comparison of international and local sustainable assessment tools of landscape design for housing estate developments : case of Bangkok Metropolitan Region, Thailand

Various countries have been introducing sustainable assessment tools for real estate design to produce integrated sustainability components not just for the building, but also the landscape component of the development. This paper aims to present the comparison between international and local assessment tools of landscape design for housing estate developments in Bangkok Metropolitan Region (BMR), Thailand. The methodologies used are to review, then compare and identify discrepancy indicators among the tools. This paper will examine four international tools; LEED for Neighbourhood Development (LEED – ND) of United State of America (USA), EnviroDevelopment standards of Australia, Residential Landscape Sustainability of United Kingdom (UK) and Green Mark for Infrastructure of Singapore; and three BMR’s existing tools; Land Subdivision Act B.E. 2543, Environmental Impact Assessment Monitoring Awards (EIA-MA) and Thai’s Rating for Energy and Environmental Sustainability of New construction and major renovation (TREES-NC). The findings show that there are twenty two elements of three categories which are neighbourhood design, community management, and environmental condition. Moreover, only one element in neighbourhood designs different between the international and local tools. The sustainable assessment tools have existed in BMR but they are not complete in only one assessment tool. Thus, the development of new comprehensive assessment tool will be necessary in BMR; however, it should meet the specific environment and climate condition for housing estate development at BMR.

Multi-criteria ranking and receptor modelling of airborne fine particles at three sites in the Pearl River Delta region of China

The multi-criteria decision making methods, Preference METHods for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GAIA), and the two-way Positive Matrix Factorization (PMF) receptor model were applied to airborne fine particle compositional data collected at three sites in Hong Kong during two monitoring campaigns held from November 2000 to October 2001 and November 2004 to October 2005. PROMETHEE/GAIA indicated that the three sites were worse during the later monitoring campaign, and that the order of the air quality at the sites during each campaign was: rural site > urban site > roadside site. The PMF analysis on the other hand, identified 6 common sources at all of the sites (diesel vehicle, fresh sea salt, secondary sulphate, soil, aged sea salt and oil combustion) which accounted for approximately 68.8 ± 8.7% of the fine particle mass at the sites. In addition, road dust, gasoline vehicle, biomass burning, secondary nitrate, and metal processing were identified at some of the sites. Secondary sulphate was found to be the highest contributor to the fine particle mass at the rural and urban sites with vehicle emission as a high contributor to the roadside site. The PMF results are broadly similar to those obtained in a previous analysis by PCA/APCS. However, the PMF analysis resolved more factors at each site than the PCA/APCS. In addition, the study demonstrated that combined results from multi-criteria decision making analysis and receptor modelling can provide more detailed information that can be used to formulate the scientific basis for mitigating air pollution in the region.

Integrated governance arrangements of airport-region urban infrastructure development : gaining insights from urban infrastructure development in the Brisbane airport region

Polarising the issue of governance is the increasingly acknowledged role of airports in regional economic development, both as significant sources of direct employment and as attractants of commerce through enhanced mobility (Vickerman, Spiekermann & Wegener 1999; Hakfoort, Poot & Rietveld 2001). Most airports were once considered spatially removed from their cities, but as cities have expanded their airports no longer sit distinct of the urban environment. This newfound spatial proximity means that decisions for land use and development on either city or airport land are likely to have impacts that affect one another in either or both the short- or long-term (Stevens, Baker and Freestone 2007). These impacts increase the demand for decision making to find ways of integrating strategies for future development to ensure that airport developments do not impede the sustainable growth of its city, and likewise that city developments do not impede the sustainable growth of its airport (Gillen 2006). However questions of how, under what conditions, and to what extent decision making integration might be suitable for “airport regions” are yet to be explored let alone answered.

Impact of zooming and enhancing Region of Interests for optimizing user experience on mobile sports video

In mobile videos, small viewing size and bitrate limitation often cause unpleasant viewing experiences, which is particularly important for fast-moving sports videos. For optimizing the overall user experience of viewing sports videos on mobile phones, this paper explores the benefits of emphasizing Region of Interest (ROI) by 1) zooming in and 2) enhancing the quality. The main goal is to measure the effectiveness of these two approaches and determine which one is more effective. To obtain a more comprehensive understanding of the overall user experience, the study considers user’s interest in video content and user’s acceptance of the perceived video quality, and compares the user experience in sports videos with other content types such as talk shows. The results from a user study with 40 subjects demonstrate that zooming and ROI-enhancement are both effective in improving the overall user experience with talk show and mid-shot soccer videos. However, for the full-shot scenes in soccer videos, only zooming is effective while ROI-enhancement has a negative effect. Moreover, user’s interest in video content directly affects not only the user experience and the acceptance of video quality, but also the effect of content type on the user experience. Finally, the overall user experience is closely related to the degree of the acceptance of video quality and the degree of the interest in video content. This study is valuable in exploiting effective approaches to improve user experience, especially in mobile sports video streaming contexts, whereby the available bandwidth is usually low or limited. It also provides further understanding of the influencing factors of user experience.

Influence of historic land use change on the biosphere-atmosphere-exchange of C and N trace gases in the humid, subtropical region of Queensland

Increases in atmospheric concentrations of the greenhouse gases (GHGs) carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) due to human activities have been linked to climate change. GHG emissions from land use change and agriculture have been identified as significant contributors to both Australia’s and the global GHG budget. This is expected to increase over the coming decades as rates of agriculture intensification and land use change accelerate to support population growth and food production. Limited data exists on CO2, CH4 and N2O trace gas fluxes from subtropical or tropical soils and land uses. To develop effective mitigation strategies a full global warming potential (GWP) accounting methodology is required that includes emissions of the three primary greenhouse gases. Mitigation strategies that focus on one gas only can inadvertently increase emissions of another. For this reason, detailed inventories of GHGs from soils and vegetation under individual land uses are urgently required for subtropical Australia. This study aimed to quantify GHG emissions over two consecutive years from three major land uses; a well-established, unfertilized subtropical grass-legume pasture, a 30 year (lychee) orchard and a remnant subtropical Gallery rainforest, all located near Mooloolah, Queensland. GHG fluxes were measured using a combination of high resolution automated sampling, coarser spatial manual sampling and laboratory incubations. Comparison between the land uses revealed that land use change can have a substantial impact on the GWP on a landscape long after the deforestation event. The conversion of rainforest to agricultural land resulted in as much as a 17 fold increase in GWP, from 251 kg CO2 eq. ha-1 yr-1 in the rainforest to 889 kg CO2 eq. ha-1 yr-1 in the pasture to 2538 kg CO2 eq. ha-1 yr-1 in the lychee plantation. This increase resulted from altered N cycling and a reduction in the aerobic capacity of the soil in the pasture and lychee systems, enhancing denitrification and nitrification events, and reducing atmospheric CH4 uptake in the soil. High infiltration, drainage and subsequent soil aeration under the rainforest limited N2O loss, as well as promoting CH4 uptake of 11.2 g CH4-C ha-1 day-1. This was among the highest reported for rainforest systems, indicating that aerated subtropical rainforests can act as substantial sink of CH4. Interannual climatic variation resulted in significantly higher N2O emission from the pasture during 2008 (5.7 g N2O-N ha day) compared to 2007 (3.9 g N2O-N ha day), despite receiving nearly 500 mm less rainfall. Nitrous oxide emissions from the pasture were highest during the summer months and were highly episodic, related more to the magnitude and distribution of rain events rather than soil moisture alone. Mean N2O emissions from the lychee plantation increased from an average of 4.0 g N2O-N ha-1 day-1, to 19.8 g N2O-N ha-1 day-1 following a split application of N fertilizer (560 kg N ha-1, equivalent to 1 kg N tree-1). The timing of the split application was found to be critical to N2O emissions, with over twice as much lost following an application in spring (emission factor (EF): 1.79%) compared to autumn (EF: 0.91%). This was attributed to the hot and moist climatic conditions and a reduction in plant N uptake during the spring creating conditions conducive to N2O loss. These findings demonstrate that land use change in subtropical Australia can be a significant source of GHGs. Moreover, the study shows that modifying the timing of fertilizer application can be an efficient way of reducing GHG emissions from subtropical horticulture.

Influence of historical landscapes, drainage evolution and ecological traits on patterns of genetic diversity in Southeast Asian freshwater snakehead fishes

Snakehead fishes in the family Channidae are obligate freshwater fishes represented by two extant genera, the African Parachannna and the Asian Channa. These species prefer still or slow flowing water bodies, where they are top predators that exercise high levels of parental care, have the ability to breathe air, can tolerate poor water quality, and interestingly, can aestivate or traverse terrestrial habitat in response to seasonal changes in freshwater habitat availability. These attributes suggest that snakehead fishes may possess high dispersal potential, irrespective of the terrestrial barriers that would otherwise constrain the distribution of most freshwater fishes. A number of biogeographical hypotheses have been developed to account for the modern distributions of snakehead fishes across two continents, including ancient vicariance during Gondwanan break-up, or recent colonisation tracking the formation of suitable climatic conditions. Taxonomic uncertainty also surrounds some members of the Channa genus, as geographical distributions for some taxa across southern and Southeast (SE) Asia are very large, and in one case is highly disjunct. The current study adopted a molecular genetics approach to gain an understanding of the evolution of this group of fishes, and in particular how the phylogeography of two Asian species may have been influenced by contemporary versus historical levels of dispersal and vicariance. First, a molecular phylogeny was constructed based on multiple DNA loci and calibrated with fossil evidence to provide a dated chronology of divergence events among extant species, and also within species with widespread geographical distributions. The data provide strong evidence that trans-continental distribution of the Channidae arose as a result of dispersal out of Asia and into Africa in the mid–Eocene. Among Asian Channa, deep divergence among lineages indicates that the Oligocene-Miocene boundary was a time of significant species radiation, potentially associated with historical changes in climate and drainage geomorphology. Mid-Miocene divergence among lineages suggests that a taxonomic revision is warranted for two taxa. Deep intra-specific divergence (~8Mya) was also detected between C. striata lineages that occur sympatrically in the Mekong River Basin. The study then examined the phylogeography and population structure of two major taxa, Channa striata (the chevron snakehead) and the C. micropeltes (the giant snakehead), across SE Asia. Species specific microsatellite loci were developed and used in addition to a mitochondrial DNA marker (Cyt b) to screen neutral genetic variation within and among wild populations. C. striata individuals were sampled across SE Asia (n=988), with the major focus being the Mekong Basin, which is the largest drainage basin in the region. The distributions of two divergent lineages were identified and admixture analysis showed that where they co-occur they are interbreeding, indicating that after long periods of evolution in isolation, divergence has not resulted in reproductive isolation. One lineage is predominantly confined to upland areas of northern Lao PDR to the north of the Khorat Plateau, while the other, which is more closely related to individuals from southern India, has a widespread distribution across mainland SE Asian and Sumatra. The phylogeographical pattern recovered is associated with past river networks, and high diversity and divergence among all populations sampled reveal that contemporary dispersal is very low for this taxon, even where populations occur in contiguous freshwater habitats. C. micropeltes (n=280) were also sampled from across the Mekong River Basin, focusing on the lower basin where it constitutes an important wild fishery resource. In comparison with C. striata, allelic diversity and genetic divergence among populations were extremely low, suggesting very recent colonisation of the greater Mekong region. Populations were significantly structured into at least three discrete populations in the lower Mekong. Results of this study have implications for establishing effective conservation plans for managing both species, that represent economically important wild fishery resources for the region. For C. micropeltes, it is likely that a single fisheries stock in the Tonle Sap Great Lake is being exploited by multiple fisheries operations, and future management initiatives for this species in this region will need to account for this. For C. striata, conservation of natural levels of genetic variation will require management initiatives designed to promote population persistence at very localised spatial scales, as the high level of population structuring uncovered for this species indicates that significant unique diversity is present at this fine spatial scale.

Rapid displacement of dengue virus type 1 by type 4, Pacific region, 2007-2009

Since 2000-2001, dengue virus type 1 has circulated in the Pacific region. However, in 2007, type 4 reemerged and has almost completely displaced the strains of type 1. If only 1 serotype circulates at any time and is replaced approximately every 5 years, DENV-3 may reappear in 2012.