35 research outputs found
The dynamics of expanding mangroves in New Zealand
In contrast to the global trend of mangrove decline, New Zealand mangroves are rapidly expanding, facilitated by elevated sediment inputs in coastal waters as a consequence of large-scale land use changes following European settlement. New Zealand mangroves are at the southern limit of the global mangrove extent, which limits the tree height of Avicennia marina var. australasica, the only mangrove species present. Mangroves in New Zealand thrive in the sheltered environments of infilling drowned river valleys with abundant supply of fine terrigenous sediments, showing various stages of mangrove succession and expansion dynamics. Bio-physical interactions and carbon dynamics in these expanding temperate mangrove systems show similarities to, but also differ from those in tropical mangrove forests, for instance due to the limited height and complexity of the mangrove communities. Likewise, ecosystem services provided by New Zealand mangroves deviate from those offered by tropical mangroves. In particular, the association of mangrove expansion with the accumulation of (the increased supply of) fine sediments and the consequent change of estuarine ecosystems, has provoked a negative perception of mangrove expansion and subsequently led to mangrove clearance. Over recent decades, a body of knowledge has been developed regarding the planning and decision making relating to mangrove removal, yet there are still effects that are unknown, for example with respect to the post-clearance recovery of the original sandflat ecosystems. In this chapter we discuss the dynamics of New Zealandâs expanding mangroves from a range of viewpoints, with the aim of elucidating the possible contributions of expanding mangroves to coastal ecosystem services, now and in the future. This chapter also reviews current policies and practice regarding mangrove removal in New Zealand and addresses the (un)known effects of mangrove clearance. These combined insights may contribute to the development of integrated coastal management strategies that recognise the full potential of expanding mangrove ecosystems
Differential expression of pro-inflammatory and oxidative stress mediators induced by nitrogen dioxide and ozone in primary human bronchial epithelial cells
CONTEXT: NO(2) and O(3) are ubiquitous air toxicants capable of inducing lung damage to the respiratory epithelium. Due to their oxidizing capabilities, these pollutants have been proposed to target specific biological pathways, but few publications have compared the pathways activated. OBJECTIVE: This work will test the premise that NO(2) and O(3) induce toxicity by activating similar cellular pathways. METHODS: Primary human bronchial epithelial cells (HBECs, n = 3 donors) were exposed for 2 hours at an air-liquid interface to 3 ppm NO(2), 0.75 ppm O(3), or filtered air and harvested 1 hr post-exposure. To give an overview of pathways that may be influenced by each exposure, gene expression was measured using PCR arrays for toxicity and oxidative stress. Based on the results, genes were selected to quantify whether expression changes were changed in a dose- and time-response manner using NO(2) (1, 2, 3, or 5 ppm), O(3) (0.25, 0.50, 0.75, or 1.00 ppm), or filtered air and harvesting 0, 1, 4 and 24 hrs post-exposure. RESULTS: Using the arrays, genes related to oxidative stress were highly induced with NO(2) while expression of pro-inflammatory and vascular function genes were found subsequent to O(3). NO(2) elicited the greatest HMOX1 response, whereas O(3) more greatly induced IL-6, IL-8, and PTGS2 expression. Additionally, O(3) elicited a greater response 1 hr post-exposure and NO(2) produced a maximal response after 4 hrs. CONCLUSION: We have demonstrated that these two oxidant gases stimulate differing mechanistic responses in vitro and these responses occur at dissimilar times
Antioxidant supplementation and nasal inflammatory responses among young asthmatics exposed to high levels of ozone
The inflammatory response to ozone in atopic asthma suggests that soluble mediators of inflammation are released in response to oxidant stress. Antioxidants may alleviate additional oxidative stress associated with photochemical oxidant pollution. This study investigates the impact of antioxidant supplementation on the nasal inflammatory response to ozone exposure in atopic asthmatic children. We conducted a randomized trial using a double-blinded design. Children with asthma (n = 117), residents of Mexico City, were given randomly a daily supplement of vitamins (50 mg/day of vitamin E and 250 mg/day of vitamin C) or placebo. Nasal lavages were performed three times during the 4-month follow-up and analysed for content of interleukin-6 (IL-6), IL-8, uric acid and glutathione (GSx). IL-6 levels in the nasal lavage were increased significantly in the placebo group after ozone exposure while no increase was observed in the supplement group. The difference in response to ozone exposure between the two groups was significant (P = 0¡02). Results were similar for IL-8, but with no significant difference between the groups (P = 0¡12). GSx decreased significantly in both groups. Uric acid decreased slightly in the placebo group. Our data suggest that vitamin C and E supplementation above the minimum dietary requirement in asthmatic children with a low intake of vitamin E might provide some protection against the nasal acute inflammatory response to ozone
Making Visible the Invisible Act of Doping
This paper describes the construction of the visual space of surveillance by the global anti-doping apparatus, it is a space inhabited daily by professional cyclists. Two principal mechanisms of this apparatus will be discussedâthe Whereabouts System and the Biological Passport; in order to illustrate how this space is constructed and how it visualises the invisible act of doping. These mechanisms act to supervise and govern the professional cyclist and work to classify them as either clean or dirty in terms of the use of prohibited doping substances or methods. Contrary to the analysis of liberal anti-doping scholars such as Hanstad, Loland and Møller this paper argues that Foucaultâs Panopticon paradigm is a useful tool for the analysis of this apparatus. The Whereabouts System and Biological Passport are the instruments by which the anti-doping apparatus intensifies the construction of the space of surveillance in professional sport. This space of surveillance not only locates and makes visible the physical location of each individual cyclist, but it also makes visible their internal bodily functions, in this case the composition and the fluctuations of the composition of their blood. In making the cyclist visible the instruments do not allow the cause of doping, or the event of doping to be known or observed. Rather what they do is cast the body in terms of abnormalities of time, place or blood. In the case of an abnormality of the cyclistâs blood, the cause itself cannot be identified with any certainty, all that is made visible is a suggestion, or a probability, that doping may have occurred. The ultimate effects are twofoldâan internalisation and continual monitoring of oneâs self as well as by the authorities, and a radical change in the nature and the definition of the offence of doping. No longer is it positive evidence of doping that is punishable, but what becomes punishable is an abnormality, in the cyclistâs location, or their body, which suggests a probability that the invisible act of doping may have occurred. In the course of this process accepted manners of proving an offence by the use of scientific evidence and expert commentary are transformed. The Whereabouts System and the Biological Passport open up a new manner in which the invisible can be visualised. Through the discourse and the attendant commentary of the expert a new alliance between doping and the law is constructed. The result is a redistribution of the way in which the law visualises and treats the symptoms (the signifier) and the signified act of doping. The Whereabouts System and Biological Passport are the instruments by which the anti-doping apparatus intensifies the construction of the space of surveillance in professional sport. This space of surveillance not only locates and makes visible the physical location of each individual cyclist, but it also makes visible their internal bodily functions, in this case the composition and the fluctuations of the composition of their blood. In making the cyclist visible the instruments do not allow the cause of doping, or the event of doping to be known or observed. Rather what they do is cast the body in terms of abnormalities of time, place or blood. In the case of an abnormality of the cyclistsâs blood, the cause itself cannot be identified with any certainty, all that is made visible is a suggestion, or a probability, that doping may have occurred. The ultimate effects are twofoldâan internalisation and continual monitoring of oneâs self as well as by the authorities, and a radical change in the nature and the definition of the offence of doping. No longer is it positive evidence of doping that is punishable, but what becomes punishable is an abnormality, in the cyclistâs location, or their body, which suggests a probability that the invisible act of doping may have occurred. In the course of this process accepted manners of proving an offence by the use of scientific evidence and expert commentary are transformed. The Whereabouts System and the Biological Passport open up a new manner in which the invisible can be visualised. Through the discourse and the attendant commentary of the expert a new alliance between doping and the law is constructed. The result is a redistribution of the way in which the law visualises and treats the symptoms (the signifier) and the signified act of doping
Is children's choice in health care rhetoric or reality? A scoping review
Aim. This paper is a report of a scoping review examining children and young people's health services with respect to choice in order to inform future development of choice initiatives. Background. The importance of including children and young people in the choice agenda reflects the increasing acknowledgement that, individually and collectively, they are important consumers of health care in their own right. Data sources. A scoping review of all major health and medical research databases was undertaken using current guidelines to identify original relevant research papers and grey literature sources from 1990 to 2006. Review methods. Reference Manager software was used to collate, summarize, categorize, store and retrieve the search results. Papers meeting the inclusion criteria were read in full and descriptively summarized using a data extraction sheet. Each paper was repeatedly selected using a snowballing approach until saturation was reached. Results. Children and young people want more say in the planning and development of appropriate hospital and community health services. However, little evaluative research was found about whether these choices are acted upon and lead to more responsive services. Conclusion. Choice for children and young people is viewed as a positive development in health care and many innovative examples of their involvement in decision-making were found. These illustrated that, given the opportunity, children and young people are willing and able to make decisions about their healthcare services. However, there is a long way to go before the rhetoric of the choice agenda is realized. Š 2008 The Authors