Our PET project: an unlimited supply of big and small water sample vials for the assay of radon in water

2015 ◽  
Vol 307 (3) ◽  
pp. 2277-2280 ◽  
Author(s):  
Paola Tuccimei ◽  
Derek Lane-Smith ◽  
Gianfranco Galli ◽  
Carlo Lucchetti ◽  
Gabriele De Simone ◽  
...  
Keyword(s):  
Water Sample ◽  
Small Water ◽  
Unlimited Supply ◽  
Radon In Water

scholarly journals Towards environmental DNA-based bioassessment of freshwater reservoirs with small volumes of water: robust molecular protocols

2021 ◽  
Author(s):  
Rebecca Ker Loh ◽  
Sujatha Narayanan Kutty ◽  
Darren Chong Jinn Yeo ◽  
Rudolf Meier
Keyword(s):  
Water Sample ◽  
Environmental Dna ◽  
Cost Effective ◽  
Sampling Time ◽  
Small Water ◽  
Tropical Reservoirs ◽  
Frequent Monitoring ◽  
Planktonic Crustaceans ◽  
Water Volumes ◽  
Dna Template

Bioassessment of freshwater quality via eDNA is rapidly developing into a powerful alternative to traditional methods involving collecting, sorting, and identifying macroinvertebrates based on morphology. Particularly attractive would be methods that can use remote-controlled boats for sampling because it would allow for cost-effective, and frequent monitoring at multiple sites. The latter will be particularly important for tropical reservoirs that require year-around surveillance. We here optimize molecular protocols for capturing reservoir-specific differences in metazoan communities based on small water volumes (15 mL). The optimization is based on samples from two freshwater reservoirs with very different water qualities ("reservoir signal"). Each reservoir was sampled at three sites ("biological replicates"). For each water sample, the DNA was extracted twice ("technical replicates"). We then tested how much DNA template (0.1 ng to 15 ng) and how many PCR cycles (25 or 35) minimized variance between technical replicates. We find that 15 mL is sufficient for capturing the reservoir signal regardless of sampling time, template amounts, or PCR cycle numbers. Indeed, extrapolation from our results suggests that <1 mL would be sufficient because only 17 of 59 metazoan mOTUs (mainly planktonic crustaceans and rotifers) detected with a 313bp COI minibarcode were shared. We find that the use of 35 PCR cycles significantly lowered the number of detected species and that template amounts <0.5 ng yielded somewhat higher variance between technical replicates. Despite extensive trials, the variance between technical replicates remained high (Bray-Curtis: 5-20%; Jaccard: 10-40%) and we predict that it will be difficult to reduce this variance further. However, the overall reservoir differences are so strong that all biological and technical replicates can be correctly assigned.

Identification of Asbestos Fibres in a Water Sample by X-Ray Microanalysis

1975 ◽  
Vol 33 ◽  
pp. 274-275
Author(s):  
K. A. Brookes ◽  
D. Finbow ◽  
Madeleine Samuel
Keyword(s):  
Water Sample ◽  
Background Radiation ◽  
X Ray ◽  
Left Hand ◽  
Transmission Imaging ◽  
Different Types ◽  
Normal Specimen ◽  
Liquid Nitrogen Cooling ◽  
Normal Transmission ◽  
Additional Port

Investigation of the particulate matter contained in the water sample, revealed the presence of a number of different types and certain of these were selected for analysis.An A.E.I. Corinth electron microscope was modified to accept a Kevex Si (Li) detector. To allow for existing instruments to be readily modified, this was kept to a minimum. An additional port is machined in the specimen region to accept the detector, with the liquid nitrogen cooling dewar conveniently housed in the left hand cupboard adjacent to the microscope column. Since background radiation leads to loss in the sensitivity of the instrument, great care has been taken to reduce this effect by screening and manufacturing components that are near the specimen from material of low atomic number. To change from normal transmission imaging to X-ray analysis, the special 4-position specimen rod is inserted through the normal specimen airlock.

Colletotrichum Gloeosporioides Species Complex: Pathogen Causing Anthracnose, Gummosis and Die-Back Diseases of Cashew (Anacardium Occidentale L.) In Ghana

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
A. Muntala ◽  
P. M. Norshie ◽  
K. G. Santo ◽  
C. K. S. Saba
Keyword(s):  
Species Complex ◽  
Colletotrichum Gloeosporioides ◽  
Potato Dextrose Agar ◽  
Causal Agent ◽  
Anacardium Occidentale ◽  
Causative Organism ◽  
Pathogenicity Test ◽  
Small Water ◽  
Colletotrichum Gloeosporioides Species Complex

A survey was conducted in twenty-five cashew (Anacardium occidentale) orchards in five communities in the Dormaa-Central Municipality of Bono Region of Ghana to assess the incidence and severity of anthracnose, gummosis and die-back diseases on cashew. Cashew diseased samples of leaves, stem, inflorescences, twigs, flowers, nuts and apples showing symptoms (e. g. small, water-soaked, circular or irregular yellow, dark or brown spots or lesions on leaves, fruits and flowers, sunken surface, especially on the apples, blight, gum exudates) were collected for isolation of presumptive causative organism. The pathogen was isolated after disinfecting the excised diseased pieces in 70% ethanol, plated on potato dextrose agar (PDA) and incubated at 28 oC for 3 to 7 days. The identity of the putative pathogen was morphologically and culturally confirmed as belonging to Colletotrichum gloeosporioides species complex using standard mycological identification protocols. The pathogen had varied conidia sizes of between 9-15 up to 20 μm in length and diameter of 3-6 μm. The conidia were straight and cylindrically shaped with rounded or obtuse ends. The septate mycelium was whitish-grey, velvety and cotton-like in appearance from the top. The results confirmed the presence of the pathogen in the orchards with incidence ranging from 6.9% and 14.0% for gummosis and averaged 22.9% for anthracnose infected orchards. The result of the pathogenicity test confirmed the isolates to be pathogenic on inoculated cashew seedlings and were consistently re-isolated, thereby establishing the pathogen as the true causal agent of the said diseases in cashew trees and thus completed the Koch’s postulate.

The impact of biometric parameters of a hydromacrophyte habitat on the structure of zooplankton communities in various types of small water bodies

2009 ◽  
Vol 38 (2) ◽  
Author(s):  
Natalia Kuczyńska-Kippen ◽  
Barbara Nagengast ◽  
Tomasz Joniak
Keyword(s):  
Water Bodies ◽  
Small Water ◽  
Biometric Parameters ◽  
Zooplankton Communities ◽  
The Impact ◽  
Small Water Bodies

The impact of biometric parameters of a hydromacrophyte habitat on the structure of zooplankton communities in various types of small water bodies

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