Mobitop: Accessing hierarchically organized georeferenced multimedia annotations

A*STA

Investigating perceptions of a location-based annotation system

A*STA

Transitions in diatom assemblages and pigments through dry and wet season conditions in the Red River, Hanoi (Vietnam)

Background and aims – Biomonitoring is an important tool for assessing river water quality, but is not routinely applied in tropical rivers. Marked hydrological changes can occur between wet and dry season conditions in the tropics. Thus, a prerequisite for ecological assessment is that the influence of ‘natural’ hydrological change on biota can be distinguished from variability driven by water quality parameters of interest. Here we aimed to (a) assess seasonal changes in water quality, diatoms and algal assemblages from river phytoplankton and artificial substrates through the dry-wet season transition (February–July 2018) in the Red River close to Hanoi and (b) evaluate the potential for microscopic counts and high-performance liquid chromatography (HPLC) analysis of chlorophyll and carotenoid pigments for biomonitoring in large tropical rivers.Methods – River water (phytoplankton) and biofilms grown on artificial glass substrates were sampled monthly through the dry (February–April) to wet (May–August) season transition and analysed via microscopic and HPLC techniques.Key results – All phototrophic communities shifted markedly between the dry and wet seasons. Phytoplankton concentrations were low (ca. thousands of cells/mL) and declined as the wet season progressed. The dominant phytoplankton taxa were centric diatoms (Aulacoseira granulata and Aulacoseira distans) and chlorophytes (Scenedesmus and Pediastrum spp.), with chlorophytes becoming more dominant in the wet season. Biofilm diatoms were dominated by Melosira varians, and areal densities declined in the wet season when fast-growing pioneer diatom taxa (e.g. Achnanthidium minutissimum, Planothidium lanceolatum) and non-degraded Chlorophyll a concentrations increased, suggesting active phytobenthos growth in response to scour damage. Otherwise, a-phorbins were very abundant in river seston and biofilms indicating in situ Chlorophyll a degradation which may be typical of tropical river environments. The very large range of total suspended solids (reaching > 120 mg L-1) and turbidity appears to be a key driver of photoautotrophs through control of light availability.Conclusions – Hydrological change and associated turbidity conditions exceed nutrient influences on photoautotrophs at inter-seasonal scales in this part of the Red River. Inter-seasonal differences might be a useful measure for biomonitoring to help track how changes in suspended solids, a major water quality issue in tropical rivers, interact with other variables of interest

Managing media rich geo-spatial annotations for a map-based mobile application using clustering

The world has still to emerge fully from the housing-triggered Global Financial Crisis, but housing crises are not new. The history of housing shows long-run social progress, littered with major disasters; nevertheless the progress is often forgotten, whilst the difficulties hit the headlines. Housing Economics provides a long-term economic perspective on macro and urban housing issues, from the Victorian era onwards. A historical perspective sheds light on modern problems and the constraints on what can be achieved; it concentrates on the key policy issues of housing supply, affordability, tenure, the distribution of migrant communities, mortgage markets and household mobility. Local case studies are interwoven with city-wide aggregate analysis. Three sets of issues are addressed: the underlying reasons for the initial establishment of residential neighbourhoods, the processes that generate growth, decline and patterns of integration/segregation, and the impact of historical development on current problems and the implications for policy

Tagnsearch: Searching and navigating geo-referenced collections of photographs

A*STAR gran

Exploring hierarchically organized georeferenced multimedia annotations in the MobiTOP system

A*STA

Sharing mobile multimedia annotations to support inquiry-based learning using Mobitop

A*STAR5820/2009</p

Sharing hierarchical mobile multimedia content using the MobiTOP system

A*STA

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions