Creation of a New European Metrology Network on Pollution Monitoring (POLMO)

Driven by a wide set of European regulations, strategies and action plans, to cope with and to minimize environmental pollution in Europe, the need for pollution monitoring especially on chemicals and radionuclides is constantly growing in importance as it supports the ambition of the European Union: “In 2050, we live well within the planet’s ecological limits”. This can be reached only on the basis of high-quality data on pollution monitoring as well as strong metrological cooperation between all relevant European partners and stakeholders. To foster this goal a strong, collaborative, multi-disciplinary, long-term and self-sustaining “European Metrology Network on pollution monitoring”, as a metrological reference infrastructure, needs to be generated and managed. Such a metrological network will be developed over the next years within the framework of an EMPIR network project called POLMO. POLMO will focus first on chemicals and radionuclides pollution in the different compartments of the environment (water, air, soil) but also will strive to expand its expertise to other areas such as light or noise pollution on longer terms. The detailed objectives of the POLMO network are: To become an international point of focus and create stronger connections for all the different stakeholder communities (active networks and associations, research centres, testing laboratories, manufacturers, industry, standardization bodies, regulators) with NMIs/DIs. This should allow new approaches to meet stakeholder requirements by developing multidisciplinary metrological research overpassing current regulatory principles. To maximize efficiency of NMIs/DIs activity and minimise resources (human, infrastructures, financial) as well as knowledge, data and best-practice transfers between NMIs/DIs and with the main EU organisations as well as stakeholders in the POLMO context. Demonstrate the role of metrology in the European research area. Moreover, to define the place and role of the metrology in the pollution monitoring chain of measurements and to demonstrate its added value and benefit. To maximize and accelerate dissemination of reliable metrology practices for pollution monitoring through mutually recognized and agreed approaches The goal of this poster is to describe how the POLMO Metrology Network will be implemented from mid 2022 in particular by the means of an EMPIR JNP (Joint Network Programme) in the framework of EURAMET (European Association of National Metrology Institutes). The project could support the need for harmonization and reliability of e-DNA measurements, as necessary to support their recognition, by organizing the development of missing metrological tools at European level

Procedures for the identification and detection of adulteration of fish and meat products

The addition or exchange of cheaper fish species instead of more expensive fish species is a known form of fraud in the food industry. This can take place accidentally due to the lack of expertise or act as a fraud. The interest in detecting animal species in meat products is based on religious demands (halal and kosher) as well as on product adulterations. Authentication of fish and meat products is critical in the food industry. Meat and fish adulteration, mainly for economic pursuit, is widespread and leads to serious public health risks, religious violations, and moral loss. Economically motivated adulteration of food is estimated to create damage of around € 8 to 12 billion per year. Rapid, effective, accurate, and reliable detection technologies are keys to effectively supervising meat and fish adulteration. Various analytical methods often based on protein or DNA measurements are utilized to identify fish and meat species. Although many strategies have been adopted to assure the authenticity of fish and meat and meat a fish products, such as the protected designation of origin, protected geographical indication, certificate of specific characteristics, and so on, the coverage is too small, and it is unrealistic to certify all meat products for protection from adulteration. Therefore, effective supervision is very important for ensuring the suitable development of the meat industry, and rapid, effective, accurate, and reliable detection technologies are fundamental technical support for this goal. Recently, several methods, including DNA analysis, protein analysis, and fat-based analysis, have been effectively employed for the identification of meat and fish species.

A novel method of quantifying sperm to determine the potential for sperm depletion in male American lobsters Homarus americanus (H. Milne Edwards, 1837) (Decapoda: Astacidea: Nephropidae)

Sperm limitation is a concern for a number of heavily fished decapods; however, work to assess this concern is sometimes hampered by a lack of simple techniques to quantify sperm transferred during reproduction. Our primary goal was to determine if DNA measurements could be used to quantify the sperm content of spermatophores and thus facilitate investigations of sperm limitation in American lobsters (Homarus americanus H. Milne Edwards, 1837). This was achieved by measuring the amount of DNA in a sample and then calibrating those values by using flow cytometry to count the number of individual sperm present in the sample. Our results show that the DNA quantification technique provides a fast and accurate way to quantify sperm. We then demonstrated the utility of the method by using it to examine the rate at which males can produce sperm under simulated conditions of repeated mating events, a situation that might lead to a reduction in the number of sperm per spermatophore. While spermatophores obtained from male lobsters at three-day intervals varied substantially in the number of sperm they contained (range 427,090–5,028,996; mean 2,306,473), there was no clear decline in sperm count over time. These results suggest that male lobsters replenish their sperm supplies rapidly, and that sperm recharge rate is unlikely to be a factor that could lead to sperm limitation in American lobster populations.

HIV-1 DNA decay dynamics in early treated individuals: practical considerations for clinical trial design

Background Initiation of combination antiretroviral therapy (cART) soon after HIV-1 infection limits the establishment of viral reservoirs. Thus, early treated individuals are preferred candidates to evaluate novel viral remission strategies. However, their cART-dependent HIV-1 DNA decay dynamics are still poorly defined. This can hamper the design and interpretation of results from clinical trials intended to further reduce viral reservoirs. Objectives To clarify the duration of cART needed for the HIV-1 reservoir to be stabilized in early treated individuals. Methods We characterized the longitudinal decline of total HIV-1 DNA levels by droplet digital PCR in 21 individuals initiating cART within 6 months after estimated HIV-1 acquisition. Measurements were taken at cART initiation, after 6 months and annually until Year 4. Correlations between virological and clinical parameters were statistically analysed. Statistical modelling was performed applying a mixed-effects model. Results Total HIV-1 DNA experienced a median overall decrease of 1.43 log10 units (IQR = 1.17–1.69) throughout the 4 years of follow-up. Baseline levels for total HIV-1 DNA, viral load, absolute CD4+ T cell count and CD4+/CD8+ ratio correlate with final HIV-1 DNA measurements (R2 = 0.68, P < 0.001; R2 = 0.54, P = 0.012; R2 = −0.47, P = 0.031; and R2 = −0.59, P = 0.0046, respectively). Statistical modelling shows that after 2 years on cART the viral reservoir had reached a set point. Conclusions A waiting period of 2 years on cART should be considered when designing interventions aiming to impact latent HIV-1 reservoir levels and viral rebound kinetics after cART discontinuation, in order to facilitate interpretation of results and enhance the chance of viral control.

Bleaching correction for DNA-measurements in highly diluted solutions using confocal microscopy

Precise and reliable determination of the nucleic acid concentration in biological samples still remains a challenge. This is particularly since the established fluorescene-based methods provide insufficient results, when only minute sample quantitites are available for analysis. Among other effects, photobleaching is the main reason for this. Since large molecules diffuse more slowly than small molecules, they are exposed to more excitation cycles and therefore have a higher probability of permanently losing their fluorescence. Solutions with large molecules hence show a reduced fluorescence. In this paper we present a method to correct this effect and thus allow high-precision sample concentration determination in minute sample quantities (< 2 µl drops with concentrations < 20 pg/µl). For this purpose, we used confocal microscopy with single molecule sensitivity. In the first step, we derived calibration curves from DNA solutions with defined fragment length. We analyzed dilution series over a wide concentration range (1 pg/µl – 1000 pg/µl) and measured their specific diffusion coefficients by employing fluorescence correlation spectroscopy. Using this information, we correct the measured fluorescence intensity of the calibration solutions for photobleaching effects. Subsequently, we evaluated our method by analyzing a series of DNA mixtures of varying composition.