106 research outputs found
Combined magnetic resonance imaging and photodynamic therapy using polyfunctionalised nanoparticles bearing robust gadolinium surface units
A robust dithiocarbamate tether allows novel gadolinium units based on DOTAGA (q = 1) to be attached to the surface of gold nanoparticles (2.6 â 4.1 nm diameter) along with functional units offering biocompatibility, targeting and photodynamic therapy. A dramatic increase in relaxivity (r1) per Gd unit from 5.01 mMâ1 sâ1 in unbound form to 31.68 mMâ1 sâ1 (10 MHz, 37 °C) is observed when immobilised on the surface due to restricted rotation and enhanced rigidity of the Gd complex on the nanoparticle surface. The singleâstep synthetic route provides a straightforward and versatile way of preparing multifunctional gold nanoparticles, including examples with conjugated zincâtetraphenylporphyrin photosensitizers. The lack of toxicity of these materials (MTT assays) is transformed on irradiation of HeLa cells for 30 minutes (PDT), leading to 75% cell death. In addition to passive targeting, the inclusion of units capable of actively targeting overexpressed folate receptors illustrates the potential of these assemblies as targeted theranostic agents
Herbivore management for biodiversity conservation: A case study of kangaroos in the Australian Capital Territory (ACT)
Populations of macropods are higher than estimated pre-European densities in many parts of Australia. To achieve appropriate densities of macropods in the Australian Capital Territory's nature reserves, multi-tenure kangaroo management units are used to tailor management of kangaroos and total grazing pressure to achieve conservation objectives. An adaptive management framework is recommended that monitors the state of the ground-layer vegetation and alters the cull accordingly. This case study may provide insights for kangaroo management in other temperate areas of Australia
Biotelemetry marches on: a cost-effective GPS device for monitoring terrestrial wildlife
<div><p>The availability of low-cost wildlife trackers increases the capacity to collect valuable ecological data when research budgets are limited. We converted a commercially available global positioning system (GPS) product into a low-cost tracking device that sends data via the mobile phone network, and assessed its performance under varying conditions. We established a stationary test, deploying devices along a continuum from open urban areas to topographically and structurally complex forested sites. We tested three features of the device: (a) the GPS, by measuring fix success rate, fix precision and horizontal dilution of precision (HDOP), (b) remote download capacity via the mobile phone network and (c) battery drain. Measures of GPS performance demonstrated high fix success rates and precision. HDOP values were influenced by habitat type and topographical position, but generally remained very low, giving an acceptable degree of error for most applications in wildlife research. Devices experienced delayed data transmission at sites with less phone reception, and faster battery drain at sites with denser vegetation. We recorded device malfunctions in 8.2% of the 110 sampling locations, but these were not associated with habitat type or topography. Our device was effective under a wide range of conditions, and the development process we used provides guidance to other researchers aiming to develop cost-effective wildlife trackers. Reducing the financial and labour costs of acquiring high-quality movement data will improve the capacity to increase sample size in animal movement studies.</p></div
Rotavirus Serotype G9P[8] and Acute Gastroenteritis Outbreak in Children, Northern Australia
Amino acid substitutions on the VP7 and NSP4 proteins were identified in regions known to influence function and may have contributed to the emergence and increased dominance of the outbreak strains
Toxic marine microalgae and shellfish poisoning in the British isles: history, review of epidemiology, and future implications
The relationship between toxic marine microalgae species and climate change has become a high profile and well discussed topic in recent years, with research focusing on the possible future impacts of changing hydrological conditions on Harmful Algal Bloom (HAB) species around the world. However, there is very little literature concerning the epidemiology of these species on marine organisms and human health. Here, we examine the current state of toxic microalgae species around the UK, in two ways: first we describe the key toxic syndromes and gather together the disparate reported data on their epidemiology from UK records and monitoring procedures. Secondly, using NHS hospital admissions and GP records from Wales, we attempt to quantify the incidence of shellfish poisoning from an independent source. We show that within the UK, outbreaks of shellfish poisoning are rare but occurring on a yearly basis in different regions and affecting a diverse range of molluscan shellfish and other marine organisms. We also show that the abundance of a species does not necessarily correlate to the rate of toxic events. Based on routine hospital records, the numbers of shellfish poisonings in the UK are very low, but the identification of the toxin involved, or even a confirmation of a poisoning event is extremely difficult to diagnose. An effective shellfish monitoring system, which shuts down aquaculture sites when toxins exceed regularity limits, has clearly prevented serious impact to human health, and remains the only viable means of monitoring the potential threat to human health. However, the closure of these sites has an adverse economic impact, and the monitoring system does not include all toxic plankton. The possible geographic spreading of toxic microalgae species is therefore a concern, as warmer waters in the Atlantic could suit several species with southern biogeographical affinities enabling them to occupy the coastal regions of the UK, but which are not yet monitored or considered to be detrimental
A qualitative study of service provision for alcohol related health issues in mid to later life
AIMS:Epidemiological surveys over the last 20 years show a steady increase in the amount of alcohol consumed by older age groups. Physiological changes and an increased likelihood of health problems and medication use make older people more likely than younger age groups to suffer negative consequences of alcohol consumption, often at lower levels. However, health services targeting excessive drinking tend to be aimed at younger age groups. The aim of this study was to gain an in-depth understanding of experiences of, and attitudes towards, support for alcohol related health issues in people aged 50 and over. METHODS:Qualitative interviews (n = 24, 12 male/12 female, ages 51-90 years) and focus groups (n = 27, 6 male/21 female, ages 50-95 years) were carried out with a purposive sample of participants who consumed alcohol or had been dependent. FINDINGS:Participants' alcohol misuse was often covert, isolated and carefully regulated. Participants tended to look first to their General Practitioner for help with alcohol. Detoxification courses had been found effective for dependent participants but only in the short term; rehabilitation facilities were appreciated but seen as difficult to access. Activities, informal groups and drop-in centres were endorsed. It was seen as difficult to secure treatment for alcohol and mental health problems together. Barriers to seeking help included functioning at a high level, concern about losing positive aspects of drinking, perceived stigma, service orientation to younger people, and fatalistic attitudes to help-seeking. Facilitators included concern about risk of fatal illness or pressure from significant people. CONCLUSION:Primary care professionals need training on improving the detection and treatment of alcohol problems among older people. There is also a compelling need to ensure that aftercare is in place to prevent relapse. Strong preferences were expressed for support to be provided by those who had experienced alcohol problems themselves
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers âŒ99% of the euchromatic genome and is accurate to an error rate of âŒ1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Population change among Pacific, kelp and silver gulls using natural and artificial feeding sites in south-eastern Tasmania
Hopping Down the Main Street: Eastern Grey Kangaroos at Home in an Urban Matrix
Most urban mammals are small. However, one of the largest marsupials, the Eastern Grey Kangaroo Macropus giganteus, occurs in some urban areas. In 2007, we embarked on a longitudinal study of this species in the seaside town of Anglesea in southern Victoria, Australia. We have captured and tagged 360 individuals to date, fitting each adult with a collar displaying its name. We have monitored survival, reproduction and movements by resighting, recapture and radio-tracking, augmented by citizen science reports of collared individuals. Kangaroos occurred throughout the town, but the golf course formed the nucleus of this urban population. The course supported a high density of kangaroos (2â5/ha), and approximately half of them were tagged. Total counts of kangaroos on the golf course were highest in summer, at the peak of the mating season, and lowest in winter, when many males but not females left the course. Almost all tagged adult females were sedentary, using only part of the golf course and adjacent native vegetation and residential blocks. In contrast, during the non-mating season (autumn and winter), many tagged adult males ranged widely across the town in a mix of native vegetation remnants, recreation reserves, vacant blocks, commercial properties and residential gardens. Annual fecundity of tagged females was generally high (â„70%), but survival of tagged juveniles was low (54%). We could not determine the cause of death of most juveniles. Vehicles were the major (47%) cause of mortality of tagged adults. Road-kills were concentrated (74%) in autumn and winter, and were heavily male biased: half of all tagged males died on roads compared with only 20% of tagged females. We predict that this novel and potent mortality factor will have profound, long-term impacts on the demography and behavior of the urban kangaroo population at Anglesea
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