Ian Campbell - Academia.edu (original) (raw)

Papers by Ian Campbell

Tissue and Cell, 1984

In mayfly nymphs of the genus C'aluhuriscoides. cell complexes with an osmoregulatory function (s... more In mayfly nymphs of the genus C'aluhuriscoides. cell complexes with an osmoregulatory function (so-called chloride cells) arc found in the integuments of the oral gills. the abdominal gills and gill filaments, the coxae and the thoracic sternites. The cutlcle overlying each cell complex is a rigid circular plate which is known to be porous to colloidal lanthanum suspensions. The present study shows that the plate is composed only of the cuticulin and dense layers of the epicuticle. Both layers have substructures built of subunits on almost perfect hexagonal lattices. The lattice spacmgs arc S3 and 9.5nm for the dense layer and the cuticulin layer respectively. During moulting the apical plasma membrane of the chloride cell remains adpressed to the old porous plate. The new porous plate is formed from a new chloride cell which intrudes from the base of the integument. Throughout the moult small pores persist in the new and otherwise continuous cuticle to allow continuity of the cytoplasm of the apical and basal portions of the old chloride cell. It is thought that this phenomenon allows osmoregulatory function of the chloride cell complex to be maintamcd during the moult.

Skin electronics require stretchable conductors that satisfy metallike conductivity, high stretch... more Skin electronics require stretchable conductors that satisfy metallike conductivity, high stretchability, ultrathin thickness, and facile patternability, but achieving these characteristics simultaneously is challenging. We present a float assembly method to fabricate a nanomembrane that meets all these requirements. The method enables a compact assembly of nanomaterials at the water–oil interface and their partial embedment in an ultrathin elastomer membrane, which can distribute the applied strain in the elastomer membrane and thus lead to a high elasticity even with the high loading of the nanomaterials. Furthermore, the structure allows cold welding and bilayer stacking, resulting in high conductivity. These properties are preserved even after high-resolution patterning by using photolithography. A multifunctional epidermal sensor array can be fabricated with the patterned nanomembranes.

SIL Proceedings, 1922-2010, 2000

Abundant water resources in Thailand have shaped agriculture and politics and society. Thai popul... more Abundant water resources in Thailand have shaped agriculture and politics and society. Thai population density has been high, largely supported by water based agriculture, rice and fish being important national staples. Although water is abundant in Thailand, the growth of large cities which "drain" water from surrounding farming areas has caused water shortages in several Thai river basins, particularly in those near Bangkok and the central plains, leading to advocacy of large scale interbasin water transfers. The published literature on limnology in Thailand is slight and expertise is limited with few researchers, few resources, limited to access to literature and lack research culture in many universities.

Aquatic Insects, 1993

ABSTRACT

Global Change Biology

Rivers suffer from multiple stressors acting simultaneously on their biota, but the consequences ... more Rivers suffer from multiple stressors acting simultaneously on their biota, but the consequences are poorly quantified at the global scale. We evaluated the biological condition of rivers globally, including the largest proportion of countries from the Global South published to date. We gathered macroinvertebrate‐ and fish‐based assessments from 72,275 and 37,676 sites, respectively, from 64 study regions across six continents and 45 nations. Because assessments were based on differing methods, different systems were consolidated into a 3‐class system: Good, Impaired, or Severely Impaired, following common guidelines. The proportion of sites in each class by study area was calculated and each region was assigned a Köppen‐Geiger climate type, Human Footprint score (addressing landscape alterations), Human Development Index (HDI) score (addressing social welfare), % rivers with good ambient water quality, % protected freshwater key biodiversity areas; and % of forest area net change r...

... For example, a number of tree species around Tonlé Sap Great Lake in Cambodia bear fruit and ... more ... For example, a number of tree species around Tonlé Sap Great Lake in Cambodia bear fruit and seeds during the time of flooding ... It is not possible to have rivers in their pristine ecological condition and still have large-scale fisheries, hydropower, large-scale irriga-tion ...

Sustainability Science, Oct 15, 2014

Kluwer Academic Publishers eBooks, 1990

1. The food of two stoneflies in an acid, iron-rich stream, consisted overwhelmingly of numerous ... more 1. The food of two stoneflies in an acid, iron-rich stream, consisted overwhelmingly of numerous small detritus particles and a few large leaf fragments. Iron bacteria, algae, fungi and pollen were present but normally sparse in gut contents and their nutritional significance is unknown. 2. In gut contents preparations, detrital food weighed 13.4 ± 0.89. 10-4 mg mm-2, and leafy food 8.3 ± 2.03. 10-4 mg mm-2. 3. Gut contents of Leuctra nigra were replaced 7.3,10.7 and 18.5 times per day and of Nemurellapicteti 10.4, 16.0 and 24.0 times per day at 5, 10 and 13.5°C, respectively. 4. These data on feeding, and quantitative estimates of population densities, enabled calculations of daily and annual population food intake to be made. Nemurella picteti consumed 30.8 g m-2 Y-I of fine detritus and 34.9 g m-2 Y-I leaves; Leuctra nigra consumed 94.7 g m-2 Y-I fine detritus and 49.1 g m-2 Y-I leaves. S toneflies thus consumed over 80 g leaf litter m-2 Y-I, comfortably exceeding the mean standing crop.

Academic Press eBooks, 2009

... 4. Historical Changes in Hydrology 5. Potential Effects of Climate Change on the ... Watercou... more ... 4. Historical Changes in Hydrology 5. Potential Effects of Climate Change on the ... Watercourse Environmental Change in Upper Mekong 1. General 2. Geohydrological Characteristics ... 374026-7 1. Environmental management--Mekong River Watershed--International cooperation ...

Frontiers in Environmental Science, Oct 19, 2020

Development of large scale hydropower is proceeding rapidly in the Mekong basin without adequate ... more Development of large scale hydropower is proceeding rapidly in the Mekong basin without adequate consideration of the severe and cumulative impacts the dams and reservoirs will, and are already beginning to, have on biodiversity, livelihoods and the economies of the lower Mekong countries. Migratory aquatic species will be particularly affected, and global experience indicates that fishways proposed for large mainstream and tributary dams will not provide effective amelioration. An offset strategy of remediating small weirs, flood control devices, regulators and irrigation works on tributaries and flood plains is more likely to be an effective and economically efficient means of supplementing fisheries to compensate for the negative impact of mainstream dams. Mainstream hydropower developments may result in future stranded assets, high electricity costs and even threaten the sovereignty of lower Mekong countries.

Verhandlungen, Dec 1, 2000

Environmental Toxicology and Chemistry, Aug 1, 1990

The relationship between copper speciation and acute toxicity to the AustraHan freshwater shrimp,... more The relationship between copper speciation and acute toxicity to the AustraHan freshwater shrimp, Paratya australiensis was determined using a combination of copper ion selective electrode measurements, complexing resins and computer calculations to measure the speciation in test solutions. A number of problems were encountered with the use of the copper ion selective electrode in waters containing added complexing agents. In solutions containing nitrilotriacetic acid or glycine, uncomplexed copper(II) ions were found to be the most acutely toxic form of copper to the shrimp. However, at least one other species, the singly charged complex (Cu-Glycine)+, also appears to be mildly toxic. The results of this study demonstrate the importance of considering metal speciation when assessing the impact of heavy metals on aquatic organisms.

Environmental Toxicology and Chemistry, 1992

Postmolt individuals of the freshwater prawn Paratya australiensis were more sensitive to copper ... more Postmolt individuals of the freshwater prawn Paratya australiensis were more sensitive to copper toxicity than individuals at other stages of the molt cycle. In contrast to other reports, molting frequently was not increased by exposure to sublethal concentrations of copper.

Verhandlungen, Mar 1, 1998

Springer eBooks, 1990

Elsevier eBooks, 2009

ABSTRACT Tonle Sap Great Lake, or Boeng Tonle Sap in Cambodian terminology, is the largest and mo... more ABSTRACT Tonle Sap Great Lake, or Boeng Tonle Sap in Cambodian terminology, is the largest and most important natural freshwater lake in Southeast Asia. It plays a critical role in Cambodian Khmer culture, in the economy of Cambodia, and in the ecology and hydrology of the Mekong River basin. Boeng Tonle Sap comprises a permanent lake surrounded by an extensive floodplain. The permanent lake consists of two basins-a large northwest basin and a smaller southeast basin-linked by a relatively narrow strait. Tonle Sap Great Lake, like much of the rest of the Mekong River system of which it forms a component, is a monotonal flood-pulsed system. The dry season permanent lake begins to enlarge as floodwaters from the Mekong back up the Tonle Sap River. The sediment-laden water flows through channels in the low levees surrounding the dry season lake margins, and extends over the extensive surrounding floodplain, depositing its sediment as if flows. Tonle Sap Great Lake is of international significance culturally, hydrologically, and ecologically. Culturally it was the center of the great Khmer civilization from at least 800 AD to the 1440s. Hydrologically the lake provides a regulator for the flow of the Mekong River into the delta of Viet Nam. Ecologically it is a key component of one of the world's largest fisheries, and certainly the largest subsistence fishery.

AGU Spring Meeting Abstracts, May 1, 2005

Bioassessment tools are being developed to assess the Ecological health of the Lower Mekong River... more Bioassessment tools are being developed to assess the Ecological health of the Lower Mekong River. A multinational team of local specialists has been established working with two international mentors. This approach allows geographical homogeneity of methods, assurance of quality and capacity building. A range of potential indicators were tested in the first year of the program, with benthic and littoral invertebrates, zooplankton and benthic diatoms finally being selected for further development. The first two year's assessments indicate that the health of the Mekong is generally good, with the exception of the Mekong delta, where population density is high and agriculture is most intensive. There is little industry in the Mekong Basin, and as yet no large dams have been constructed. Surveys will be conducted on a three to five year cycle, with different regions in the basin being targeted each year. Development of appropriate metrics to quantify river health is now a priority.

SIL Proceedings, 1922-2010, 1998