From continental extension to seafloor spreading: crustal structure of the Goban Spur rifted margin, southwest of the UK     

Andrew D. Bullock  Timothy A. Minshull 《Geophysical Journal International》2005,163(2):527-546

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Editors' Introduction: The Practices of Fieldwork     

Stuart Corbridge  Emma Mawdsley 《Singapore journal of tropical geography》2003,24(2):145-146

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Dissolved and particulate organic carbon in Chesapeake Bay     

Thomas R. Fisher  James D. Hagy  Emma Rochelle-Newall 《Estuaries and Coasts》1998,21(2):215-229

We measured dissolved and particulate organic carbon (DOC and POC) in samples collected along 13 transects of the salinity gradient of Chesapeake Bay. Riverine DOC and POC end-members averaged 232±19 μM and 151±53 μM, respectively, and coastal DOC and POC end-members averaged 172±19 μM and 43±6 μM, respectively. Within the chlorophyll maximum, POC accumulated to concentrations 50–150 μM above those expected from conservative mixing and it was significantly correlated with chlorophylla, indicating phytoplankton origin. POC accumulated primarily in bottom waters in spring, and primarily in surface waters in summer. Net DOC accumulation (60–120 μM) was observed within and downstream of the chlorophyll maximum, primarily during spring and summer in both surface and bottom waters, and it also appeared to be derived from phytoplankton. In the turbidity maximum, there were also net decreases in chlorophylla (?3 μg l^?1 to ?22 μg l^?1) and POC concentrations (?2 μM to ?89 μM) and transient DOC increases (9–88 μM), primarily in summer. These occurred as freshwater plankton blooms mixed with turbid, low salinity seawater, and we attribute the observed POC and DOC changes to lysis and sedimentation of freshwater plankton. DOC accumulation in both regions of Chesapeake Bay was estimated to be greater than atmospheric or terrestrial organic carbon inputs and was equivalent to ≈10% of estuarine primary production.  相似文献   

Abnormal terns,sick sea and shore birds,organochlorines and arboviruses in the Indian Ocean     

W.R.P. Bourne  J.A. Bogan  D. Bullock  A.W. Diamond  C.J. Feare 《Marine pollution bulletin》1977,8(7):154-158

It has been suggested that congenital abnormalities and defects of feather growth of young terns along the east coast of the USA may be due to organochlorine pollution. Similar abnormalities are also found in young terns and neurological symptoms in terns and other species in the Indian Ocean, where there is still little pollution, in association with an acute infestation of ticks infected with arboviruses. It is postulated infection with the viruses provides an alternative explanation for the abnormalities seen in the birds.  相似文献   

Long-term growth rates of cirio (Fouquieria columnaris), a giant succulent of the Sonoran Desert in Baja California     

Martín Escoto-Rodríguez  Stephen H. Bullock   《Journal of Arid Environments》2002,50(4):593

Factors affecting temporal and spatial variations of growth were studied in cirio, a succulent often surpassing 10 m in height. Measurements were obtained for intervals of 3–93 years at 14 sites in Baja California. Height tended to be asymptotic but total plant length (i.e. including all succulent stems) increased in linear relation to trunk diameter. Growth in length showed an overall average of 4·6 cm year⁻¹ but ranged from 0·3–16·7 cm year⁻¹ (annualized from data for intervals >34 year). Most of the variation was among individuals, but some differences between sites were also significant. Growth was clearly and strongly related to size only for individuals less than 1 m in height. Repeated measures on the same individuals showed that the autocorrelation of growth was about 0·8 between intervals of 3 or more years. Differences among individuals were related to physiographic position, the presence of caliche and the density of neighboring plants, which together explained 43% of the variation. We discuss the implications of these results for age estimates, indicators of site quality and studies of similar plants.  相似文献   

Palaeontology,stratigraphy and sedimentology of Woodeaton Quarry (Oxfordshire) and a new microvertebrate site from the White Limestone Formation (Bathonian,Jurassic)     

Simon Wills  Emma Louise Bernard  Philippa Brewer  Charlie J. Underwood  David J. Ward 《Proceedings of the Geologists' Association. Geologists' Association》2019,130(2):170-186

Woodeaton Quarry in Oxfordshire has previously yielded a number of large sauropod vertebrae and other (unpublished) dinosaur remains from a horizon in the Rutland Formation. No review of the wider terrestrial fauna from Woodeaton has been published to date. Here we present an overview of new material recovered from a microvertebrate site at the top of the White Limestone Formation (Middle Jurassic, Bathonian, Great Oolite Group, Retrocostatum Zone) and review the stratigraphy to provide a comprehensive local stratigraphic framework and place the quarry in the correct regional context. The terrestrial fauna is similar to that found from other UK Bathonian microvertebrate sites and includes probable dromaeosaurid theropods, ornithischians, tritylodontids and mammaliaforms such as amphitheriids, docodonts, ‘eutriconodonts’, ‘haramyids’ and multituberculates. Placement of the White Limestone Formation boundaries are clarified with respect to the Rutland and Forest Marble Formations. This indicates that the microvertebrate bed from Woodeaton is slightly older than that of the well-known mammal bed from nearby Kirtlington Quarry.  相似文献   

A new deal for lone parents? Training lone parents for work in West London     

Fiona Smith  John Barker  Emma Wainwright  Elodie Marandet  Sue Buckingham 《Area》2008,40(2):237-244

In this paper we explore the impacts of the training programmes offered to lone mothers with young children on the Government's 'New Deal for Lone Parents' in one local labour market: West London. Our research suggests that regulatory workfare policies are (re)producing and reinforcing gendered inequalities in the labour market by encouraging lone mothers to undertake training in feminised occupational areas such as childcare. We will argue that in a local economy such as West London where more childcare workers are desperately needed to enable other more highly skilled workers to take up employment opportunities, such training programmes may be doing little more than exacerbating the already gendered and class-based polarisation of the labour market – embedding low-skilled, poorly qualified lone mothers into low-paid jobs.  相似文献   

Comparison of long-term and short-term uplift rates along an active blind reverse fault zone (Bajo Segura,Se Spain)     

Jordi Giménez  Maria J. Borque  Antonio J. Gil  Pedro Alfaro  Antonio Estévez  Emma Suriñach 《Studia Geophysica et Geodaetica》2009,53(1):81-98

The seismic activity of the Guardamar-Torrevieja zone (Eastern Betic Cordillera, SE Spain) can be associated with the Bajo Segura fault zone, an E-W reverse blind fault with secondary NW-SE dextral faults. A high-precision levelling profile 30 kilometers long was set up and levelled in 1997 to monitor the vertical displacement of this active fault zone. This profile runs parallel to an older high-precision levelling line included in the Spanish first order levelling network measured by the Instituto Geográfico Nacional (IGN) in two different campaigns (1934 and 1976). The 1997 line was relevelled in 2003 and 10 new benchmarks were set up, both to increase benchmark density and to restore some of the 1997 benchmarks that had been destroyed. We have used the 1976 IGN and the 2003 measurement to construct a recent vertical movements profile with a significant time difference (27 years). This recent vertical movements profile shows that the vertical movements are very small, nearly equal to the error bars, with a 0.2 mm/year rise in the town of Guardamar, and a 0.2 mm/year subsidence of the southern part of the profile (Punta Prima) respect to the town of Torrevieja. These movements could be related to the activity of the Bajo Segura and the San Miguel faults respectively. Using geological markers we have deduced uplift rates of 0.1 mm/year during the last 3 million years. Therefore, these preliminary results indicate that geodetically (short-term deformation) determined uplift rates are similar to those estimated from geological markers (long term deformation).  相似文献   

Respiration,growth and grazing rates of three ciliate species in hypoxic conditions     

Emma Rocke  Hongbin Liu 《Marine pollution bulletin》2014

Marine hypoxic episodes are affecting both marine and freshwater bodies all over the world. Yet, limited data exists with regard to the effects of decreasing oxygen on protist metabolism. Three ciliate species were therefore isolated from Hong Kong coastal waters. Controlled hypoxic conditions were simulated in the lab environment, during which time growth, respiration and grazing rates were measured. Euplotes sp. and a Oxytrichidae-like ciliate showed decreased growth and respiration below 2.5 mg O₂ L⁻¹, however Uronema marinum kept steady growth and respiration until below 1.5 mg O₂ L⁻¹. Euplotes sp. and the Oxytrichidae-like ciliate had the highest ingestion rate, which dropped significantly below 3.0 mg O₂ L⁻¹. U.marinum grazing rates were affected at and below 1.5 mg O₂ L⁻¹, correlating with their drop in growth and respiration at this lower concentration. This study illustrates the slowing metabolism of key grazing protists, as well as species-specific tolerance in response to hypoxia.  相似文献   

Reactivity of dissolved organic matter in response to acid deposition     

Sara M. Ekström  Margareta Sandahl  P. Anders Nilsson  Dan B. Kleja  Emma S. Kritzberg 《Aquatic Sciences - Research Across Boundaries》2016,78(3):463-475

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