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Graphical Models for Forensic Analysis
Published in Marloes Maathuis, Mathias Drton, Steffen Lauritzen, Martin Wainwright, Handbook of Graphical Models, 2018
A. Philip Dawid, Julia Mortera
The networks above only use the qualitative information as to which allele values are present in the mixture and the other profiles. A more sensitive analysis additionally uses measured continuous “peak heights” or “peak areas”, which give quantitative information on the amounts of DNA involved. (The DNA is amplified using the polymerase chain reaction (PCR) process and the peak height, or area, is a measure of the amount of the allele in the amplified sample expressed in relative fluorescence units.) This requires much more detailed modeling, but again this can be effected by means of a Bayesian network [5]. Because the mixture proportion frac of DNA contributed by one of the parties is a quantity common across all markers, we must now handle the markers all simultaneously within one “super-network”. Figure shows the top level network for two contributors, involving six markers (D8, vWA, D21, D18, FGA, TH01), each an instance of a module marker as shown in Figure . This network is an extended version of the one shown in Figure , incorporating additional structure to model the quantitative peak height information. In particular, the nodes Aweight etc. in marker are instances of a module that models the quantitative information on the peak height.
Methods for Biological Determination
Published in V. Dean Adams, Water and Wastewater Examination Manual, 2017
Turner Model 111-003Open the door and insert the primary filter (5-60) on the right side of the instrument. Slide in the secondary filter (2-64) on the left side.Turn on the power to the instrument and then the light source. Open the door and make certain the light source is on by looking through the primary filter. Allow about five minutes for the instrument to warm up.Note: Emissions from the blue light source can be harmful to the eye. Do not look directly into the lamp for any length of time.Fill a cuvette with 90% acetone for use as a blank. It is important to clean the outside of the cuvette thoroughly for blanks and samples.Place the blank in the sample compartment and set the fluorometer dial to zero using the blank knob.Measure the relative fluorescence of the standards and samples. Change the window (30X, 10X, 3X) by sliding the window orifice as necessary. Avoid any readings that are less than 20 or greater than 80 relative fluorescence units. Record relative fluorescence and the window (30X, 10X, 3X) used.Note 1: Use the IX window only for indication of dilutions needed. Results in this range will not be linear due to quenching effects.Note 2: Make sure that each sample is read using a window where five standards have been read also.Note 3: Rezero the fluorometer often and every time the window is changed.Acidify the samples and standards in the cuvettes one at a time with 2 drops of IN HCl. Gently agitate.Record the fluorescence not sooner than 1 minute or later than 2 minutes after acidification. Treat all samples identically.Note: The fluorescence should always decrease after acidification.Turn the power switch to off and clean the sample compartment.Pour all extracted samples and waste acetone into a labeled container for repurification by distillation.
Hybrid three-dimensional modelling for reservoir fluorescent dissolved organic matter risk assessment
Published in Inland Waters, 2022
Xinchen Wang, Hong Zhang, Edoardo Bertone, Rodney A. Stewart, Sara P. Hughes
In Tingalpa Reservoir, fDOM was measured using an EXO fDOM Smart Sensor (YSO.com) installed in a vertical profiling system (VPS) consisting of a buoy with a set of water quality probes underneath that are winched up and down the water column. The EXO fDOM fluorescence-based Smart Sensor has 365 ± 5 nm excitation and 480 ± 40 nm emission wavelength to estimate the quantity of fluorescent, humic-like DOM reported as relative fluorescence units (RFU) or quinine sulphate units (QSU). The measured fluorescence region is mainly representative of humic DOM, which has proven to be the dominant DOM during storm events (Nguyen et al. 2010). Historical preliminary data for Tingalpa Reservoir also identified humic, terrestrial DOM dominant during these events over autochthonous, protein-like DOM, which could prevail under dry conditions. Hence, the focus on storm events allows us to model the most likely worst-case scenarios for the water treatment operators.
Phosphorus limitation in low nitrogen lakes in New Zealand
Published in Inland Waters, 2022
Stephanie J. Guildford, Robert E. Hecky, Piet Verburg, Anathea Albert
Phosphatase enzymes associated with P-deficient phytoplankton in lake water act on the added substrate 4-methylumbelliferyl phosphate (4MUP) releasing phosphate and resulting in fluorescence, which was measured in relative fluorescence units with a fluorescence plate reader. The substrate was diluted in 0.2 µm filtered Tris buffer adjusted to pH 8.3 and added to the water sample to achieve a final concentration of 10 µM P. Fluorescence was standardized with 4-methylumbelliferone (4MU), which is naturally fluorescing. Substrate was also added to filtered freshwater media containing no P to monitor any nonbiological production of fluorescence during the assay. The 4MUP substrate was added to all wells except for the standard curve to start the reaction. The reaction temperature was set at 37 °C, and readings were taken every 10 min at excitation/emission wavelengths of 380/454 nm for 60 min. The rate of APA was normalized to Chl-a.
Bacteria-targeting chitosan/carbon dots nanocomposite with membrane disruptive properties improve eradication rate of Helicobacter pylori
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Muhammad Arif, Mohamed Sharaf, Quanjiang Dong, Lili Wang, Zhe Chi, Chen-Guang Liu
A colony of H. pylori was implanted into an LB Broth solution. The culture was incubated at 37 ºC with constant shaking for 18 h before being diluted at 1:100 in fresh media and incubated at 37 ºC until the OD600 value reached about 1.0. Approximately 5 × 106 bacterial cells were treated with different concentration of UCPM-NPs, CPM-NPs or CDs for 8 h. Following treatment, the culture was centrifuged, and the bacterial pellets were resuspended in an equal volume of 1 × PBS buffer (200 μL, pH 7.4). Before measuring fluorescence, 50 μL NPN (20 mM final concentration) was mixed with the treated bacteria and vortexed for 3 min. The bacterial suspension was then measured using a fluorimeter (Fluorolog-3, Horiba Scientific, USA) at 350 nm excitation wavelength and 420 nm emission wavelength. The results were expressed as relative fluorescence units: the fluorescence value of cell suspension with the test substance and NPN subtracted with the corresponding value of the cell suspension and NPN without the test substance.