Determination of hydrophobicity index: standard and mini disk infiltrometers

Non-Peer ReviewedSoil hydrophobicity drastically impacts water infiltration, retention and transport. Hydrophobicity index, a ratio of the sorptivity of water to ethanol, is a common measure of soil hydrophobicity. The sorptivity may be measured using the disk infiltrometer. The standard disk infiltrometer is large, cumbersome and expensive while the mini disk infiltrometer is compact and readily accessible. The objective of this study was to determine if the mini disk infiltrometer is comparable to the standard disk infiltrometer as a means of analyzing the soil hydrophobicity index. The soil hydrophobicity index was calculated from the sorptivities of water and ethanol as determined by both infiltrometer methods. Results indicate no statistical difference between soil hydrophobicity indices calculated from the standard and mini disk infiltrometer methods

Fungal surface measurements: water contact angles

Non-Peer ReviewedFungal surface properties have been implicated as one of the main factors affecting fungal colonization and adhesion to plant surfaces. Characterization of fungal surfaces through hydrophobic measurements is important for understanding its function. Water contact angles are a direct and simple approach for characterization of fungal surface hydrophobicity. The objective of this study was to evaluate if utilization of undisturbed fungal cultures coupled with versatile image analysis allow for more accurate contact angle measurements. Fungal cultures were grown on agar slide media and contact angles were measured utilizing a modified microscope and digital camera setup, with Low Bond Axisymmetric Drop Shape Analysis Model (LB_ADSA) for contact angle determination. Fungal strains were categorized into hydrophobic, hydrophilic and a newly defined hydroamphiphilic class containing fungi taxa with changing hydrophobicity

Temporal and spatial variations in nutrient stoichiometry and regulation of phytoplankton biomass in Hong Kong waters : influence of the Pearl River outflow and sewage inputs

Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Pollution Bulletin 57 (2008): 335-348, doi:10.1016/j.marpolbul.2008.01.020.In 2001, the Hong Kong government implemented the Harbor Area Treatment Scheme (HATS) under which 70% of the sewage that had been formerly discharged into Victoria Harbor is now collected and sent to Stonecutters Island Sewage Works where it receives chemically enhanced primary treatment (CEPT), and is then discharged into waters west of the Harbor. The relocation of the sewage discharge will possibly change the nutrient dynamics and phytoplankton biomass in this area. Therefore, there is a need to examine the factors that regulate phytoplankton growth in Hong Kong waters in order to understand future impacts. Based on a historic nutrient data set (1986-2001), a comparison of ambient nutrient ratios with the Redfield ratio (N:P:Si=16:1:16) showed clear spatial variations in the factors that regulate phytoplankton biomass along a west (estuary) to east (coastal/oceanic) transect through Hong Kong waters. Algal biomass was constrained by a combination of low light conditions, a rapid change in salinity, and strong turbulent mixing in western waters throughout the year. Potential stoichiometric Si limitation (up to 94% of the cases in winter) occurred in Victoria Harbor due to the contribution of sewage effluent with high N and P enrichment all year, except for summer when the frequency of stoichiometric Si limitation (48%) was the same as P, owing to the influence of the high Si in the Pearl River discharge. In the eastern waters, potential N limitation and N and P co-limitation occurred in autumn and winter respectively, because of the dominance of coastal/oceanic water with low nutrients and low N:P ratios. In contrast, potential Si limitation occurred in spring and a switch to potential N, P and Si limitation occurred in eastern waters in summer. In southern waters, there was a shift from P limitation (80%) in summer due to the influence of the N-rich Pearl River discharge, to N limitation (68%) in autumn, and to N and P co-limitation in winter due to the dominance of N-poor oceanic water from the oligotrophic South China Sea. Our results show clear temporal and spatial variations in the nutrient stoichiometry which indicates potential regulation of phytoplankton biomass in HK waters due to the combination of the seasonal exchange of the Pearl River discharge and oceanic water, sewage effluent inputs, and strong hydrodynamic mixing from SW monsoon winds in summer and the NE monsoon winds in winter.Financial support for this research was provided by the University Grants Council of Hong Kong AoE project (AoE/P-04/0401), and RGC project HKUST6478/05M. Support was also provided (to DMA) by U.S. National Science Foundation grants OCE-0402707 and OCE-0430724 and by NIEHS grant 1 P50-ES01274201

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Middle- and High-Latitude Mesosphere and Lower Thermosphere Mean Winds and Tides in Response to Strong Polar-Night Jet Oscillations

The dynamical behavior of the mesosphere and lower thermosphere (MLT) region during strongly disturbed wintertime conditions commonly known as polar-night jet oscillations (PJOs) is described in detail and compared to other wintertime conditions. For this purpose, wind measurements provided by two specular meteor radars located at Andenes (69°N, 16°E) and Juliusruh (54°N, 13°E) are used to estimate horizontal mean winds and tides as an observational basis. Winds and tidal main features are analyzed and compared for three different cases: major sudden stratospheric warming (SSW) with (a) strong PJO event, (b) non-PJO event, and (c) no major SSWs. We show that the distinction into strong PJOs, non-PJOs, and winters with no major SSWs is better suited to identify differences in the behavior of the mean winds and tides during the boreal winter. To assess the impact of the stratospheric disturbed conditions on the MLT region, we investigate the 30-year nudged simulation by the Extended Canadian Middle Atmosphere Model. Analysis of geopotential height disturbances suggests that changes in the location of the polar vortex at mesospheric heights are responsible for the jets observed in the MLT mean winds during strong PJOs, which in turn influence the evolution of semidiurnal tides by increasing or decreasing their amplitudes depending on the tidal component. © 2019. The Authors

Green roof and energy – role of climate and design elements in hot and temperate climates

In the past few decades, the air temperature of built environment and energy demand of buildings has been increased, particularly in summer. As a consequence, the number of heat waves, heat-related mortality and morbidity have increased. The wide application of air conditioning and high level of energy use are inevitable to save people's lives, particularly in hot and temperate climates. Under these circumstances, this study offers a scoping review of the articles published between 2000 and 2020 to evaluate the role of green roofs in building energy use in hot and temperate climates. Given the ongoing trend of urban overheating, the scope of this review is limited to hot–humid, temperate and hot–dry climate zones. This scoping review shows the benefits of green roofs for reducing the demand of building energy in different climate zones and highlights the higher magnitude of energy saving in temperate climates than hot-humid or hot-dry climates provided that the green roofs are well-irrigated and uninsulated. According to the review of the articles published between 2000 and 2020, the reduction in cooling load is maximum (mean 50.2%) in temperate climate zones for well-irrigated green roofs. The effectiveness in saving cooling load reduces in hot–humid and hot-dry climate zones with means of 10% and 14.8% respectively. Green roof's design elements also strongly influence the potential in saving energy, and the effectiveness is heavily influenced by background climatic conditions. The findings of this study assist building designers and communities to better understand the amount of energy savings due to green roofs and present the results in different climates quantitatively

Environmental management system vs green specifications: How do they complement each other in the construction industry?

Environmental Management System (EMS) has been one of the important tools for sustainable construction for around two decades. However, many issues concerning sustainable development have not been properly addressed, and there is a need for the introduction of green specifications to advance green performance in construction through contract management. This paper defines green specifications, identifies the reasons for adopting green specifications and highlights the environmental issues that may not be addressed by solely adopting EMS. It also presents the results of a recent survey of practitioners concerning their opinions towards green specifications and possible impacts arising from their adoption. From the results of the survey, a framework for developing green specifications is deemed valuable for the cities striving for sustainability. Interestingly, the level of acceptable changes brought about by green specifications as perceived by different industry stakeholders is found to be unrelated to whether they were from organizations implementing EMS or not