Flavonol glycoside distribution in cultivars and hybrids of Leucaena leucocephala

Flavonol glycosides found in the leaves of Leucaena leucocephala comprised the 3-arabinosides, 3-rhamnosides and 3-glucuronides of quercetin and myricetin, and quercetin-3-rhamnosylglucoside, at a total concentration of 3–4%. In cultivars of high productivity (Peru, El Salvador (K28) and Cunningham) all seven compounds occurred with a largely constant pattern of relative concentrations. However in the cosmopolitan form naturalised throughout the tropics the 3-arabinosides were invariably absent. The same feature which was conspicuous on the high performance liquid chromatography trace, occurred with a low frequency (ca 10%) in Peru and Cunningham. The pattern provides a quick method for identifying the provenance of commercial leucaena leaf meal, and also for detecting blending or adulteration with other leaf meals. The flavonol glycoside distribution of those species associated with ‘leucaena’ leaf meal (Acacia villosa, Calliandra calothyrsus, Manihot utilissima and Sesbania grandiflora) is very different, and all have fewer compounds. All compounds occur in the apical tissue of young leucaena seedlings, enabling identification of cultivar from seed in 10 days. Comparison of leaf flavonol patterns for L. leucocephala, L. pulverulenta their known F₁ hybrid, and an entity known locally in Java as ‘L. glabrata’ strongly suggest a hybrid origin for the latter.     

Degradation of disinfection byproducts by carbonate green rust

Disinfection byproducts (DBPs) in drinking water flowing through corroded iron or steel pipes may encounter carbonate green rust (GR(CO32-)), a mixed Fe(II)/Fe(lll) hydroxide mineral and potent reductant. This research was performed to investigate the kinetics and pathways of the degradation of selected halogenated DBPs in the presence of GR(C032-). Trichloronitromethane was rapidly degraded to methylamine via sequential hydrogenolysis followed by nitro-reduction. Haloacetic acids reacted solely via sequential hydrogenolysis. Trichloroacetonitrile, 1,1,1-trichloropropanone, and trichloroacetaldehyde hydrate were transformed via hydrolysis and hydrogenolysis. Chloroform was unreactive over 300 h. The buffer identity affected reductive dehalogenation rates of DBPs, with faster rates in MOPS buffer than in carbonate buffer, the latter being representative of the buffer in drinking water systems. GR(CO32-) was unstable in both buffers and transformed to magnetite within 48 h. Thus, slower reacting compounds (half life >3 hours) were transformed by a combination of minerals. Reductive dehalogenation kinetics were influenced by DBP chemical structure and correlated with one-electron reduction potential.     

Campylobacter in waterfowl and aquatic environments: incidence and methods of detection

Campylobacters are emerging as one of the most significant causes of human infections worldwide, and the role that waterfowl and the aquatic environment have in the spread of disease is beginning to be elucidated. On a world scale campylobacters are possibly the major cause of gastrointestinal infections. Campylobacters are common commensals in the intestinal tract of many species of wild birds, including waterfowl. They are also widely distributed in aquatic environments where their origins may include waterfowl as well as sewage effluents and agricultural runoff. Campylobacters have marked seasonal trends. In temperate aquatic environments they peak during winter, whereas spring-summer is the peak period for human infection. Campylobacter species may survive, and remain potentially pathogenic, for long periods in aquatic environments. The utility of bacterial fecal indicators in predicting the presence of campylobacters in natural waters is questionable. Viable but nonculturable Campylobacter cells may occur, but whether they have any role in the generation of outbreaks of campylobacteriosis is unclear. The routine detection of Campylobacter spp. in avian feces and environmental waters largely relies on conventional culture methods, while the recognition of a particular species or strain is based on serotyping and increasingly on molecular methods. Thus, PCR combined with selective enrichment enhances the detection of campylobacters in water and feces, while DNA sequencing facilitates recognition of particular species and strains.     

Illegal unregulated and unreported fishing: Methods and increasing trends in Lake Naivasha,Kenya

Illegal, unregulated and unreported (IUU) fishing is a negative social vice that adversely affects global capture fishery production. The inadequate disclosure of IUU methods and trends in fishery waters hampers management actions to curb illegal fishing activities. Seldom have empirical studies been conducted on IUU methods and their trends in Lake Naivasha. Therefore, this study analysed data on the fisheries monitoring, control and surveillance (MCS) during 2012 to 2018 to test for the significance of trends, and compare the enforcement plans to seizures of illegal fishing gear in the lake. The IUU fishing methods included both the types of equipment and the means used to perpetrate illicit capture or acquisition of fish from the lake. The results indicate a 37% reduction of MCS enforcement patrols during 2018 compared to 2012, and a 16% to 100% upsurge in the quantity of seized IUU fishing items. Illegal fishing boats potentially threaten the fishery of Lake Naivasha with an additional fishing effort of 22% above the 176 licensed boats. An average of 10,700 fishing nets seized per year has the potential fishing intensity of 74 gillnets/km² against an ideal intensity of 12 gillnets/km². The frequencies of MCS patrols in Lake Naivasha exhibit no particular trends and likely ineffective in deterring the upsurge of IUU activities, or the evolution of new illegal fishing methods. An increased seizure of illegal fishing boats, outboard engines and gillnets could imply their rampant use in IUU fishing activities. These findings merit a multi‐stakeholder participatory approach to identifying the MCS weaknesses and opportunities for sharing resources to strengthen the fishery management efforts in Lake Naivasha.     

A Three-Stage Approach for Segmenting Degraded Color Images: Smoothing,Lifting and Thresholding (SLaT)

In this paper, we propose a Smoothing, Lifting and Thresholding (SLaT) method with three stages for multiphase segmentation of color images corrupted by different degradations: noise, information loss and blur. At the first stage, a convex variant of the Mumford–Shah model is applied to each channel to obtain a smooth image. We show that the model has unique solution under different degradations. In order to properly handle the color information, the second stage is dimension lifting where we consider a new vector-valued image composed of the restored image and its transform in a secondary color space to provide additional information. This ensures that even if the first color space has highly correlated channels, we can still have enough information to give good segmentation results. In the last stage, we apply multichannel thresholding to the combined vector-valued image to find the segmentation. The number of phases is only required in the last stage, so users can modify it without the need of solving the previous stages again. Experiments demonstrate that our SLaT method gives excellent results in terms of segmentation quality and CPU time in comparison with other state-of-the-art segmentation methods.     

A Novel Image Secret Sharing Scheme without Third-Party Scrambling Method

Mobile Networks and Applications - Values such as cellular sum in initial configurations and neighbor radius can potentially affect confusion and diffusion in cellular automata. Specifically, both...     

Process-to-Policy (P2Pol): using carbon emission pinch analysis (CEPA) tools for policy-making in the energy sector

Clean Technologies and Environmental Policy - Global warming is a major international issue due to rising levels of greenhouse gases such as CO2. Many countries now face the challenge to find...     

Learning from failure: understanding the anticipated–achieved building energy performance gap

Over the past 20 years a number of studies have identified and provided explanations for a significant ‘performance gap' between designed and actual energy performance of buildings. The anticipated and achieved energy performance of an advanced, innovative building that aspired to net-positive energy performance is studied: the Centre for Interactive Research on Sustainability (CIRS) building at the University of British Columbia in Vancouver, Canada. Selected performance ‘failures’ that became evident during operation of CIRS are studied for how they were discovered and the efforts required for their resolution: the energy systems and associated controls and monitoring. The key findings show the barriers were neither economic nor technical. Instead, the primary impediments were institutional regimes – arising from the ways that various life-cycle stages were specified, contracted and implemented. The key issues emphasize the importance of having meaningful and effective building energy monitoring capabilities, an understanding of energy system boundaries in design and analysis, crossing the gaps between different stages of a building life cycle, and feedback processes throughout design and operation. The disclosure of ‘failure’ and lessons learned is a valuable contribution to subsequent advancement for the building stakeholders and the wider professional and research communities.