Tolerance to heavy metals in Littorina saxatilis from a metal contaminated estuary in the Isle of Man

2004 ◽  
Vol 84 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Erema R. Daka ◽  
Stephen J. Hawkins
Keyword(s):  
Littorina Saxatilis ◽  
Co Tolerance ◽  
Isle Of Man ◽  
Run Off ◽  
High Zinc ◽  
Lead Tolerance ◽  
Test Concentration ◽  
A Site ◽  
High Lead ◽  
Tolerance To Copper

Population differences were measured in the tolerance of Littorina saxatilis from sites around the Isle of Man, to acute exposure to zinc, lead, copper and cadmium. Animals from a site influenced by disused mine run-off in Laxey estuary (high zinc) were compared with animals from less contaminated estuaries (Peel-high lead, but lower zinc), and the relatively uncontaminated Castletown and Ramsey estuaries, plus the open coast near Derbyhaven. Median lethal times (LT50) were estimated for each test concentration (5, 10, 20 mg l−1 Zn; 5, 10 mg l−1 Pb; 0·5, 1·0, 2·0 mg l−1 Cu and Cd) except for those that did not produce sufficient mortalities. Individuals from Laxey estuary showed significantly higher tolerances to zinc (10 mg l−1) and lead (5 mg l−1) than animals from the unpolluted sites. No co-tolerance to copper or cadmium was apparent. Population tolerance to zinc was correlated with reduced accumulation rates. Lead tolerance may result from the ability of the tolerant individuals to sequester the metal and detoxify it in their tissues; the littorinids from Laxey had significantly higher rates of lead accumulation.

scholarly journals The Escherichia coli cysG promoter belongs to the ‘extended −10’ class of bacterial promoters

1993 ◽  
Vol 296 (3) ◽  
pp. 851-857 ◽  
Author(s):  
T Belyaeva ◽  
L Griffiths ◽  
S Minchin ◽  
J Cole ◽  
S Busby
Keyword(s):  
Escherichia Coli ◽  
Point Mutations ◽  
Growth Conditions ◽  
Upstream Region ◽  
E Coli ◽  
Run Off ◽  
A Site ◽  
Specific Sequences

The Escherichia coli cysG promoter has been subcloned and shown to function constitutively in a range of different growth conditions. Point mutations identify the -10 hexamer and an important 5′-TGN-3′ motif immediately upstream. The effects of different deletions suggest that specific sequences in the -35 region are not essential for the activity of this promoter in vivo. This conclusion was confirmed by in vitro run-off transcription assays. The DNAase I footprint of RNA polymerase at the cysG promoter reveals extended protection upstream of the transcript start, and studies with potassium permanganate as a probe suggest that the upstream region is distorted in open complexes. Taken together, the results show that the cysG promoter belongs to the ‘extended -10’ class of promoters, and the base sequence is similar to that of the P1 promoter of the E. coli galactose operon, another promoter in this class. In vivo, messenger initiated at the cysG promoter appears to be processed by cleavage at a site 41 bases downstream from the transcript start point.

scholarly journals Environmental Issues within the Chlor-Alkali Manufacturing Industry -

2012 ◽  
Vol 69 (2) ◽  
Author(s):  
Tania MIHAIESCU ◽  
Radu MIHAIESCU ◽  
Antonia ODAGIU
Keyword(s):  
Manufacturing Industry ◽  
Mercury Contamination ◽  
Mercury Compounds ◽  
Mercury Cell ◽  
Run Off ◽  
Plant Equipment ◽  
Pollutant Source ◽  
Almost All ◽  
A Site ◽  
Diffuse Emissions

At present is estimated that around 12000 tones of mercury are contained in mercury cells used for chlorine production in the EU. Mercury contamination risk, remains active for long periods after the removing of the pollutant source, and is recognized as extremely dangerous for humans and environment due to the toxicity of various mercury compounds that can accumulate in the trophic chains. Almost all facilities using mercury -cell process reports unaccounted for mercury losses. The annual mercury balance for a site is never zero. This is because mercury accumulates in plant equipment and structures during the life of the plant. The majority of mercury losses occur, in the various process wastes. Considerable emissions of mercury can also occur with run-off water. The soil at many sites is contaminated with mercury due to deposition of atmospheric diffuse emissions and/or historical disposal of mercury contaminated wastes. An even greater problem is represented by the decommissioning of obsolete facilities when large quantities of mercury can escape in the environment despite all precaution measures.

A Neolithic Site at Ronaldsway, Isle of Man

1947 ◽  
Vol 13 ◽  
pp. 139-160 ◽  
Author(s):  
J. R. Bruce ◽  
E. M. Megaw ◽  
B. R. S. Megaw
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Chance Discovery ◽  
Isle Of Man ◽  
Neolithic Site ◽  
Pioneer Study ◽  
A Site

When, in 1935, Dr Grahame Clark rediscovered the unpublished finds from a site at Glencrutchery, near Douglas in the Isle of Man, he at once realised that he had come upon the relics of a culture that was new to British archaeology. Its age and affinities were quite unknown, and in his most useful pioneer study (Clark, 1935, pp. 85–91) of the material, Dr Clark suggested that it should be assigned to a period which he called the ‘Ultimate Bronze Age’ of the Island, perhaps contemporary with the Iron Age in Britain.Investigation of material from other Manx sites subsequently made a much earlier dating seem likely, and this impression was confirmed in 1943 by the discovery of a richly-furnished dwelling site at Ronaldsway. Thanks to this chance discovery it is now apparent that we have to deal with a new facet of Neolithic civilisation in these Islands. So far it is known to us only in the Isle of Man.

Eels Under Standing Wave Conditions

1982 ◽  
Vol 40 ◽  
pp. 492-495
Author(s):  
O.L. Krivanek ◽  
J. TaftØ
Keyword(s):  
Standing Wave ◽  
Wave Conditions ◽  
Set Up ◽  
A Site ◽  
Complex Crystal

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.

Head Size and DNA Content in Bacteriophage T4

1972 ◽  
Vol 30 ◽  
pp. 200-201
Author(s):  
Fred Eiserling ◽  
A. H. Doermann ◽  
Linde Boehner
Keyword(s):  
Electron Microscopy ◽  
Dna Content ◽  
Bacteriophage T4 ◽  
Head Size ◽  
Virus Particles ◽  
Altered Protein ◽  
A Cell ◽  
Bacterial Viruses ◽  
A Site ◽  
Protein Shell

The control of form or shape inheritance can be approached by studying the morphogenesis of bacterial viruses. Shape variants of bacteriophage T4 with altered protein shell (capsid) size and nucleic acid (DNA) content have been found by electron microscopy, and a mutant (E920g in gene 66) controlling head size has been described. This mutant produces short-headed particles which contain 2/3 the normal DNA content and which are non-viable when only one particle infects a cell (Fig. 1).We report here the isolation of a new mutant (191c) which also appears to be in gene 66 but at a site distinct from E920g. The most striking phenotype of the mutant is the production of about 10% of the phage yield as “giant” virus particles, from 3 to 8 times longer than normal phage (Fig. 2).

Exploration-Stage Implementation Variation

2014 ◽  
Vol 222 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Stephanie Romney ◽  
Nathaniel Israel ◽  
Danijela Zlatevski
Keyword(s):  
Parent Training ◽  
Average Cost ◽  
Cost Savings ◽  
Training Group ◽  
Group Differences ◽  
Triple P ◽  
Community Based ◽  
Parent Training Program ◽  
A Site ◽  
The Cost

The present study examines the effect of agency-level implementation variation on the cost-effectiveness of an evidence-based parent training program (Positive Parenting Program: “Triple P”). Staff from six community-based agencies participated in a five-day training to prepare them to deliver a 12-week Triple P parent training group to caregivers. Prior to the training, administrators and staff from four of the agencies completed a site readiness process intended to prepare them for the implementation demands of successfully delivering the group, while the other two agencies did not complete the process. Following the delivery of each agency’s first Triple P group, the graduation rate and average cost per class graduate were calculated. The average cost-per-graduate was over seven times higher for the two agencies that had not completed the readiness process than for the four completing agencies ($7,811 vs. $1,052). The contrast in costs was due to high participant attrition in the Triple P groups delivered by the two agencies that did not complete the readiness process. The odds of Triple P participants graduating were 12.2 times greater for those in groups run by sites that had completed the readiness process. This differential attrition was not accounted for by between-group differences in participant characteristics at pretest. While the natural design of this study limits the ability to empirically test all alternative explanations, these findings indicate a striking cost savings for sites completing the readiness process and support the thoughtful application of readiness procedures in the early stages of an implementation initiative.

Sign in / Sign up

Export Citation Format

Share Document