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Dive into the research topics where Mika Peck is active.

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Featured researches published by Mika Peck.


Environmental Toxicology and Chemistry | 2004

Sediments are major sinks of steroidal estrogens in two United Kingdom rivers

Mika Peck; Richard Gibson; Andreas Kortenkamp; Elizabeth M. Hill

The occurrence of intersex fish in a number of European rivers has been attributed to exposure to estrogenic chemicals present in sewage treatment work (STW) effluents. To further understand the environmental fate of these contaminants, the estrogenic activity of effluents, water, and sediments were investigated both upstream and downstream of the major STW discharge in two United Kingdom rivers. Estrogenic activity, determined using the yeast estrogen-receptor transcription screen, of the major STW effluents on both rivers was similar, ranging from 1.4 to 2.9 ng 17beta-estradiol equivalents (EEQ)/L. Estrogenic activities of surface waters 1 km upstream and downstream of both STW inputs were less than the limits of detection (0.04 ng/L); however, levels of estrogenic activity in sediments were between 21.3 and 29.9 ng EEQ/kg and were similar at both upstream and downstream sites. Effluent and sediment extracts were fractionated by reverse phase-high-performance liquid chromatography, and estrogenic active fractions were further analyzed by gas chromatography-mass spectrometry. The major active chemicals in the two effluents and in the sediments were estrone with lesser amounts of 17beta-estradiol; however, at one site, a number of other unidentified estrogenic fractions were detected in the sediments. These results suggest that riverine sediments are a major sink and a potential source of persistent estrogenic contaminants.


Steroids | 2007

Identification of the steroid fatty acid ester conjugates formed in vivo in Mytilus edulis as a result of exposure to estrogens

Pierre Labadie; Mika Peck; Christophe Minier; Elizabeth M. Hill

Vertebrate-type sex steroids have been detected in a number of mollusk species and may play a role in the reproductive physiology of the animal. Mollusks are also exposed to exogenous estrogenic steroids that are present in sewage effluents, and these may add to the estrogenic burden of exposed animals. We investigated the uptake of estrogens in the blue mussel, Mytlius edulis and report for the first time the identity of estrogen fatty acid ester metabolites formed in vivo in an invertebrate. We exposed mussels to waterborne radiolabeled [(14)C]-17beta-estradiol (E2) or estrone (E1) and determined the nature of their metabolites using radio-HPLC and mass spectrometry (MS). After 13 days of exposure to 10ng/L E2, concentrations of radiolabeled residues were 2428-fold higher in M. edulis soft tissues compared with the ambient water concentration of E2. All the E2 residues in the mussel were present as a lipophilic ester which, in depuration studies, had a half-life of 8.3 days. Exposure of mussels to [(14)C]-E1 (70ng/L) resulted in formation of a similar lipophilic metabolite that after hydrolysis released [(14)C]-E2. Tandem MSMS analyses of the purified steroid ester fraction isolated from mussels exposed to either E2 or E1 revealed that they had the same composition and comprised C16:0, C16:1 and C16:2 esters of E2. This work reveals that in vivo E1 is rapidly metabolized to E2 in mussels prior to conjugation to C16 fatty acid esters, proving that C17-ketoreductase and C16 fatty acid acyl-CoA:E2 acyltransferase are important enzymes for the metabolism of estrogens in M. edulis.


Marine Pollution Bulletin | 2008

Ras gene in marine mussels: a molecular level response to petrochemical exposure.

Inês Lima; Mika Peck; J. Rendón-von Osten; Amadeu M.V.M. Soares; Lúcia Guilhermino; Jeanette M. Rotchell

Mussels are susceptible to numerous toxicants and are often employed as bioindicators. This study investigated the status of the ras proto-oncogene in Mytilus galloprovincialis following petrochemical exposure. A M. galloprovincialis homologue of the vertebrate ras gene was isolated, showing conserved sequence in regions of functional importance and a high incidence of polymorphic variation. Mutational damage was investigated in mussels chronically exposed to the water-accommodated fraction of #4 fuel-oil (WAF), and in mussels collected along the NW coast of Portugal in sites with different levels of petrochemical contamination. A ras gene point mutation was identified in the codon 35 of one individual exposed to 12.5% WAF. No mutations were detected in mussels from the WAF control or environmental samples. This represents the first report of a ras gene mutation, experimentally-induced by petrochemical exposure, in an invertebrate species.


Zootaxa | 2014

A new species of Riama Gray, 1858 (Squamata: Gymnophthalmidae) from the Tropical Andes

Vanessa Aguirre-Peñafiel; Omar Torres-Carvajal; Pedro M. Sales Nunes; Mika Peck; Simon T. Maddock

A new species of Riama lizard from the western slopes of the Andes in northern Ecuador is described herein. Morphologically, Riama yumborum sp. nov. can be distinguished from all other congenerics by having an incomplete nasoloreal suture and a cylindrical hemipenial body with diagonally orientated flounces on its lateral aspect. Phylogenetic analyses of mitochondrial and nuclear DNA support the monophyly of the new species and its sister taxon relationship with R. labionis, which occurs allopatrically.


American Journal of Primatology | 2014

Research and in situ conservation of owl monkeys enhances environmental law enforcement at the Colombian‐Peruvian border

Angela M. Maldonado; Mika Peck

This study reports on impacts of illegal trade in owl monkeys (Aotus nancymaae, A. vociferans) for the biomedical research market in the Colombian‐Peruvian Amazonian border. Through freedom of information requests and interviews with hunters we found that 912 owl monkeys, including A. nancymaae captured in Peru, were trapped over a 3‐month period in 2012 to supply a malaria research facility based in Leticia, Colombia, which had trapping permits for the use of only 800 A. vociferans annually yet experimentation took place using A. nancymaae. High levels of extraction in Peru have had population‐level impacts with significantly lower densities of Aotus spp. (3–24 individuals/km2) compared to Colombian sites with low hunting pressure (26–44 individuals/km2). Post‐experimental release of this species in Colombian territory has created a new distribution whose status and impacts on resident populations of A. vociferans remain unknown. The trapping method has also had environmental impact, with loss of over 65,000 trees (including sleeping sites), annually. As Aotus species are registered under the Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II, international trade requires official permission and evidence that extraction does not impact wild populations. However, no official records exist and CITES legislation has failed, due principally to a lack of appropriate monitoring by national authorities responsible for compliance. Of further concern is that we had previously documented and reported the illegal trade to the appropriate governmental authorities yet still no action was taken—as demonstrated by the continuing trade in 2013. Enforcement eventually occurred when a non‐governmental organization initiated legal action against organizations responsible. A successful second instance ruling by the Colombian States Council in 2013 revoked trapping permits. Using the trade in owl monkeys as a case study we consider implementation, compliance, and enforcement of CITES in the border area to identify mechanisms to improve enforcement of environmental legislation. Am. J. Primatol. 76:658–669, 2014.


PeerJ | 2016

A new method for ecoacoustics? Toward the extraction and evaluation of ecologically-meaningful soundscape components using sparse coding methods

Alice Eldridge; Michael A. Casey; Paola Moscoso; Mika Peck

Passive acoustic monitoring is emerging as a promising non-invasive proxy for ecological complexity with potential as a tool for remote assessment and monitoring (Sueur & Farina, 2015). Rather than attempting to recognise species-specific calls, either manually or automatically, there is a growing interest in evaluating the global acoustic environment. Positioned within the conceptual framework of ecoacoustics, a growing number of indices have been proposed which aim to capture community-level dynamics by (e.g., Pieretti, Farina & Morri, 2011; Farina, 2014; Sueur et al., 2008b) by providing statistical summaries of the frequency or time domain signal. Although promising, the ecological relevance and efficacy as a monitoring tool of these indices is still unclear. In this paper we suggest that by virtue of operating in the time or frequency domain, existing indices are limited in their ability to access key structural information in the spectro-temporal domain. Alternative methods in which time-frequency dynamics are preserved are considered. Sparse-coding and source separation algorithms (specifically, shift-invariant probabilistic latent component analysis in 2D) are proposed as a means to access and summarise time-frequency dynamics which may be more ecologically-meaningful.


conference of the international speech communication association | 2016

Sinusoidal modelling for ecoacoustics

Patrice Guyot; Alice Eldridge; Ying Chen Eyre-Walker; Alison Johnston; Thomas Pellegrini; Mika Peck

Biodiversity assessment is a central and urgent task, necessary to monitoring the changes to ecological systems and under- standing the factors which drive these changes. Technological advances are providing new approaches to monitoring, which are particularly useful in remote regions. Situated within the framework of the emerging field of ecoacoustics, there is grow- ing interest in the possibility of extracting ecological informa- tion from digital recordings of the acoustic environment. Rather than focusing on identification of individual species, an increas- ing number of automated indices attempt to summarise acoustic activity at the community level, in order to provide a proxy for biodiversity. Originally designed for speech processing, sinu- soidal modelling has previously been used as a bioacoustic tool, for example to detect particular bird species. In this paper, we demonstrate the use of sinusoidal modelling as a proxy for bird abundance. Using data from acoustic surveys made during the breeding season in UK woodland, the number of extracted sinusoidal tracks is shown to correlate with estimates of bird abundance made by expert ornithologists listening to the recordings. We also report ongoing work exploring a new approach to investigate the composition of calls in spectro-temporal space that constitutes a promising new method for Ecoaoustic biodiversity assessment.


Journal of Ecoacoustics | 2018

Emotional associations with soundscape reflect human-environment relationships

Paola Moscoso; Mika Peck; Alice Eldridge

In line with the development of socio-ecological perspectives in conservation science, there is increasing interest in the role of soundscape perception in understanding human-environment interactions; the impact of natural soundscapes on human wellbeing is also increasingly recognized. However, research to date has focused on preferences and attitudes to western, urban locations. This study investigated individual emotional associations with local soundscape for three social groups living in areas with distinct degrees of urbanization, from pristine forest and pre-urban landscapes in Ecuador, to urban environments in UK and USA. Participants described sounds that they associated with a range of emotions, both positive and negative, which were categorized according to an adapted version of Schafer’s sound classification scheme. Analyses included a description of the sound types occurring in each environment, an evaluation of the associations between sound types and emotions across social groups, and the elaboration of a soundscape perception map. Statistical analyses revealed that the distribution of sound types differed between groups, reflecting essential traits of each soundscape and tracing the gradient of urbanization. However, some associations were universal: Natural Sounds were primarily associated with positive emotions, whereas Mechanical and Industrial Sounds were linked to negative emotions. Within nonurban environments, natural sounds were associated with a much wider range of emotions. Our analyses suggest that Natural Sounds could be considered as valuable natural resources that promotes human wellbeing. Special attention is required within these endangered forest locations, which should be classified as a ‘threatened soundscapes’, as well as ‘threatened ecosystems’, as we begin to understand the role of soundscape for the wellbeing of the local communities. The methodology presented in this paper offers a fast, cheap tool for identifying reactions towards landscape modification and identifying sounds of social relevance. The potential contribution of soundscape perception within the current conservation approaches is discussed.


Journal of Experimental Marine Biology and Ecology | 2006

Biomarker responses of the estuarine brown shrimp Crangon crangon L. to non-toxic stressors: Temperature, salinity and handling stress effects

Salomé Menezes; Amadeu M.V.M. Soares; Lúcia Guilhermino; Mika Peck


Chemosphere | 2007

Profiles of environmental and endogenous estrogens in the zebra mussel (Dreissena polymorpha)

Mika Peck; Pierre Labadie; Christophe Minier; Elizabeth M. Hill

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Sam Shanee

Oxford Brookes University

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