Duplicate Samples Research Articles

Donor Notification and Response Rate in a Stand-alone Blood Center in Western India

Background and Objectives: Counseling and notification of reactive blood donors play an important part in maintaining the chain of safe blood. The process of notification involves informing donors about the status of their reactivity against five major and mandatory transfusion-transmitted infections (TTIs). Such notification and timely follow-up till the donor reaches the referred place help in reducing the burden of TTI in society, thereby improving blood safety. The aim of this study is to highlight the importance of prompt donor notification, referral, and follow-up. Materials and Methods: This was a retrospective cross-sectional study carried out at a stand-alone blood center from January 2019 to October 2021. A total of 36,162 donations were screened for the five mandatory TTIs-HIV (I and II), hepatitis C virus (HCV), hepatitis B virus (HBV), syphilis, and malaria. All reactive results were retested with a duplicate tube sample and a bag sample to confirm the reactivity. Donors were notified regarding the serostatus by phone and called for reporting at our blood center, and referred to Integrated Testing & Counseling Centre (ICTC) or any other referral center. Results: A total of 212 (0.58%) out of 36162 donors were tested reactive during the study period. Out of them, 40.56% (n = 86) were hepatitis B virus reactive, 21.7% (n = 46) were HIV (I and II) reactive, 20.7% (n = 44) were HCV reactive, and remaining 17.1% (n = 36) were syphilis reactive. All the donors were informed. Out of them, 71.69% (n = 152) responded to the communication and 52.83% (n = 112) personally visited the blood center or respective ICTC for further evaluation. Conclusion: Even after laying strict criteria for predonation screening and counseling, few donors do conceal their high-risk behavior or even their serostatus and continue to donate blood, leading to the wastage of resources. Thorough follow-up of seroreactive donors helps in improving blood safety and also improves their quality of life by the commencement of timely treatment.

Pharmacological Treatment of Early-Onset Schizophrenia: A Critical Review, Evidence-Based Clinical Guidance and Unmet Needs

Early-onset schizophrenia (EOS) – onset before age 18 – is linked with great disease burden and disability. Decision-making for EOS pharmacological treatment may be challenging due to conflicting information from evidence and guidelines and unidentified care needs may remain unmet.We searched for systematic reviews, meta-analyses and umbrella reviews of EOS pharmacological treatment published in PubMed over the past 10 years and selected five clinical guidelines from Europe, North-America and Australia. Based on predefined outcomes, we critically compared the evidence supporting EOS-approved drugs in Europe and/or North-America with guidelines recommendations. We also evaluated the coverage of these outcomes to identify unmet needs.One systematic review, nine meta-analyses and two umbrella reviews (k=203 trials, N=81,289 participants, including duplicated samples across selected articles) were retrieved. Evidence supported the efficacy of aripiprazole, clozapine, haloperidol, lurasidone, molindone, olanzapine, quetiapine, risperidone and paliperidone in EOS, all of which obtained approval for EOS either in Europe and/or in North-America. Cognition, functioning and quality of life, suicidal behaviour and mortality and services utilisation and cost-effectiveness were poorly covered/uncovered.Among the antipsychotics approved for EOS, aripiprazole, lurasidone, molindone, risperidone, paliperidone and quetiapine emerged as efficacious and comparably safe options. Olanzapine is known for a high risk of weight gain and haloperidol for extrapyramidal side-effects. Treatment-resistant patients should be offered clozapine. Future long-term trials looking at cognition, functioning, quality of life, suicidal behaviour, mortality, services utilisation and cost-effectiveness are warranted. Closer multi-agency collaboration may bridge the gap between evidence, guidelines and approved drugs.

The history of seed banking and the hazards of backup.

Seeds and other plant materials in seed and gene bank collections are rarely considered adequately conserved today unless genetically identical duplicate samples have been created and safely stored elsewhere. This paper explores the history of seed banking to understand how, why and with what consequences copying collections came to occupy this central place. It highlights a shift in the guiding metaphor for long-term preservation of seed collections, from banking to backup. To understand the causes and consequences of this shift in metaphor, the paper traces the intertwined histories of the central long-term seed storage facility of the United States (opened in 1958) and the international seed conservation system into which that facility was integrated in the 1970s. This account reveals how changing conceptions of security, linked to changing economic, political and technological circumstances, transformed both the guiding metaphors and the practices of seed conservation in these institutions. Early instantiations of long-term cold storage facilities vested security in robust infrastructures and the capacities of professional staff; between the 1960s and 1990s, this configuration gave way to one in which security was situated in copies rather than capacities. This observation ultimately raises questions about the security promised and achieved through present-day infrastructures for crop genetic resources conservation.

O-252 Next generation sequencing analysis of the seminal microbiome in male partners of women with idiopathic recurrent pregnancy loss: results of a prospective cohort study

Abstract Study question Is there an association between the semen microbiome, seminal reactive oxygen species (ROS) and DNA fragmentation in men with recurrent pregnancy loss (RPL)? Summary answer This pilot study outlines the subtle role that microbiota play in influencing ROS and sperm DNA damage for male partners of women with RPL What is known already RPL is defined as the loss of two or more consecutive pregnancies. This devastating condition impacts approximately 1% of couples. Paternal causes are not routinely screened for and an underlying cause is not found in up to 50% of cases. Recent studies have reported an association between elevated seminal ROS and sperm DNA fragmentation in the male partner, and RPL. We hypothesised that seminal microbiota contribute to increased ROS and sperm DNA damage. To test this, we investigated the relationship between seminal bacterial composition and ROS levels in men with proven fertility versus men with a history of RPL. Study design, size, duration We conducted a prospective, case-control study and recruited participants between November 2018 and March 2020 at Imperial College Healthcare NHS Trust. A total of 109 men participated in the study; 46 men with RPL and 63 men with proven fertility and no history of RPL. Each participant attended for a single study visit which consisted of a full medical history, assessment of testicular volume, height, weight, blood samples and production of a semen sample. Participants/materials, setting, methods Routine semen analysis (WHO) and endocrine and lipid profiles were performed for all patients. Semen ROS and DNA fragmentation were performed (luminol and TUNEL methodologies, respectively). ROS were classified as high (>3.77 RLU/s) or low (<3.77 RLU/s). Metataxonomic profiling of samples was performed using Illumina Miseq-based sequencing of the V1-V2 hypervariable regions of bacterial 16S rRNA gene amplicons. Multivariate and univariate modelling was performed to explore associations between metataxonomic profiles, ROS levels and clinical metadata. Main results and the role of chance Men with RPL had higher mean semen volume (p = 0.02) and increased prevalence of high ROS (p = 0.02, Fisher's exact) compared with controls; but other clinical characteristics were similar between groups. A total of 3,700,136 high quality sequence reads were generated for the dataset with an average of 33,946 reads/sample. Hierarchical clustering of bacterial genera relative abundances identified 4 distinct microbial signatures characterised by high relative abundance of 1. Streptococcus, 2. Lactobacillus and Gardnerella, 3. polymicrobial (including Prevotella), and 4. Corynebacterium and Finegoldia. Prevalences of these groups were similar in control and RPL groups (p = 0.11). Additionally, no association between the bacterial genera groups and elevated ROS, DNA fragmentation, or clinical factors such as age, ethnicity, or semen volume were observed (chi-square tests). At species taxonomy level relative abundance of L. crispatus was higher in controls compared to RPL, but did not withstand false discovery rate correction for multiple testing (p = 0.006, q = 0.67). Higher relative abundance of Microbacterium was detected in semen samples with high DNA fragmentation (p = 8.7E-4, q = 0.08). This relationship was even stronger within the RPL cohort (p = 2.8E-5, q = 0.002). No significant enrichment of specific taxa was observed between high or low ROS samples however, low ROS was associated with Corynebacterium relative abundance >20%. Limitations, reasons for caution More patients are required to enhance statistical power. Duplicate sample collection may establish the robustness of seminal compositions observed. Time since last sexual intercourse samples may affect the analysis. Concomitant analysis of the vaginal microbiome of female partners may improve our understanding of how partners may affect each other’s fertility. Wider implications of the findings Our data suggests interactions between microbiota composition, ROS and sperm DNA damage which may be implicated in the pathogenesis of recurrent miscarriage. Further studies are needed to determine if seminal microbiota play causal roles in RPL, and whether interventions modifying the seminal microbiome may modify pregnancy outcomes in affected couples Trial registration number not applicable

Determination of Total Amino Acids in Infant Formulas, Adult Nutritionals, Dairy, and Cereal Matrixes by UHPLC-UV: Interlaboratory Validation Study, Final Action 2018.06.

A method for the quantification of total amino acids (including taurine and excluding tryptophan) using ultra- HPLC separation coupled to UV detection (UHPLC-UV) was granted First Action status (AOAC 2018.06) by the AOAC INTERNATIONAL Stakeholder Program for Infant Formula and Adult Nutritionals (SPIFAN) in 2018. An interlaboratory study was conducted to further assess method performance against the AOAC Standard Method Performance Requirements (AOAC SMPR® 2014.013). Dairy and cereal matrixes were added to expand the scope of the method in collaboration with IDF (International Dairy Federation), ISO (International Organization for Standardization), and AACCI (American Association of Cereal Chemists International, now Cereals & Grains Association). Sixteen different matrixes were chosen to cover the requirements of AOAC, IDF/ISO, and AACCI. Blind duplicate samples were organized into specific series to ensure that each pair was analyzed on the same day. Fifteen laboratories returned results. Data from four laboratories were considered invalid and removed from the dataset. Remaining data were assessed according to the Appendix D of the AOAC Official Methods of AnalysisSM (guidelines for collaborative study procedures). This method generally met the requirements listed in the SMPR for infant formulas and adult nutritionals, except for taurine. Method performance was comparable in dairy and cereal matrixes. Five different UHPLC instruments were used with either commercial or in-house reagents, demonstrating that the method is not limited to a single supplier. This method was recommended for Final Action in infant and adult/pediatric nutritional formulas by the AOAC SPIFAN Nutrients Expert Review Panel in April 2021, with the exception of taurine. The corresponding IDF/ISO Draft International Standard (DIS) was approved by national bodies in May 2022, and comments collected during the ballot were incorporated into this manuscript. AOAC Official Method 2018.06 for the determination of total amino acids in infant formulas, adult nutritionals, dairy, and cereal matrixes was successfully validated in an interlaboratory study.

Millimeter-wave gas spectroscopy for breath analysis of COPD patients in comparison to GC-MS

The analysis of human breath is a very active area of research, driven by the vision of a fast, easy, and non-invasive tool for medical diagnoses at the point of care. Millimeter-wave gas spectroscopy (MMWGS) is a novel, well-suited technique for this application as it provides high sensitivity, specificity and selectivity. Most of all, it offers the perspective of compact low-cost systems to be used in doctors’ offices or hospitals. In this work, we demonstrate the analysis of breath samples acquired in a medical environment using MMWGS and evaluate validity, reliability, as well as limitations and perspectives of the method. To this end, we investigated 28 duplicate samples from chronic obstructive lung disease patients and compared the results to gas chromatography-mass spectrometry (GC-MS). The quantification of the data was conducted using a calibration-free fit model, which describes the data precisely and delivers absolute quantities. For ethanol, acetone, and acetonitrile, the results agree well with the GC-MS measurements and are as reliable as GC-MS. The duplicate samples deviate from the mean values by only 6% to 18%. Detection limits of MMWGS depend strongly on the molecular species. For example, acetonitrile can be traced down to 1.8 × 10−12 mol by the MMWGS system, which is comparable to the GC-MS system. We observed correlations of abundances between formaldehyde and acetaldehyde as well as between acetonitrile and acetaldehyde, which demonstrates the potential of MMWGS for breath research.

Global distributions, source-type dependencies, and concentration ranges of per- and polyfluoroalkyl substances in groundwater

A meta-analysis was conducted of published literature reporting concentrations of per- and polyfluoroalkyl substances (PFAS) in groundwater for sites distributed in 20 countries across the globe. Data for >35 PFAS were aggregated from 96 reports published from 1999 to 2021. The final data set comprises approximately 21,000 data points after removal of time-series and duplicate samples as well as non-detects. The reported concentrations range over many orders of magnitude, from ng/L to mg/L levels. Distinct differences in concentration ranges are observed between sites located within or near sources versus those that are not. Perfluorooctanoic acid (PFOA), ranging from <0.03 ng/L to ~7 mg/L, and perfluorooctanesulfonic acid (PFOS), ranging from 0.01 ng/L to ~5 mg/L, were the two most reported PFAS. The highest PFAS concentration in groundwater is ~15 mg/L reported for the replacement-PFAS 6:2 fluorotelomer sulfonate (6:2 FTS). Maximum reported groundwater concentrations for PFOA and PFOS were compared to concentrations reported for soils, surface waters, marine waters, and precipitation. Soil concentrations are generally significantly higher than those reported for the other media. This accrues to soil being the primary entry point for PFAS release into the environment for many sites, as well as the generally significantly greater retention capacity of soil compared to the other media. The presence of PFAS has been reported for all media in all regions tested, including areas that are far removed from specific PFAS sources. This gives rise to the existence of a “background” concentration of PFAS that must be accounted for in both regional and site-specific risk assessments. The presence of this background is a reflection of the large-scale use of PFAS, their general recalcitrance, and the action of long-range transport processes that distribute PFAS across regional and global scales. This ubiquitous distribution has the potential to significantly impact the quality and availability of water resources in many regions. In addition, the pervasive presence of PFAS in the environment engenders concerns for impacts to ecosystem and human health.

Determination of Quality of Green Chili Sauce Served by Street Food Venders (SFVs) in Delhi (India)

Background: India is enriched with local culture and street food vending practices. Street food joints (SFJs) cater to the demands of the economic and on-the-go needs of the consumers. In view of its increasing popularity, the quality and safety aspects of street foods need continuous evaluation. Objectives: There are few studies in our country focusing on the quality determination of sauces being served as an accompaniment to street foods by local vendors. Therefore, this study was undertaken to assess the quality of commonly served green chili sauce. Methods: A total of 100 samples in duplicate of green chili sauce were collected from street food joints in five geographical zones of Delhi. The pH, titratable acidity, and total soluble solids (TSS) content on a salt-free basis were assessed for all samples using standardized estimation techniques given by the national regulator (Food Safety and Standards Authority of India- FSSAI). Results: The pH of the samples was in the range of 3.1-5.1. The average titratable acidity expressed as acetic acid was 0.67± 0.25 %, which is below the limit of 1% given by FSSAI. The average TSS content (salt-free basis) was found to be 6.23 ± 3.75 %, which is well below the regulatory limit of 8%. Only 25% of samples conformed to the national regulatory limits for all parameters. Conclusion: Stringent surveillance system which lays emphasis on the training of microentrepreneurs needs to be framed to ensure regulatory compliance amongst small-scale manufacturers of street foods such as green chili sauce.

Investigation of selenium nutritional status and dietary pattern among children in Kashin-Beck disease endemic areas in Shaanxi Province, China using duplicate portion sampling method.

Selenium deficiency is a primary risk factor of Kashin-Beck disease (KBD). This study aimed to investigate whether children in endemic areas could maintain sufficient selenium intake after termination of selenium supplement administration, and evaluate their comprehensive nutritional status and dietary structure. Duplicate portion sampling combined with a questionnaire was adopted to collect data on categories and quantity of all food ingested in three consecutive days. Occipital hair was also collected to detect selenium content by hydride generation atomic fluorescence spectrometry (HGAFS). CDGSS3.0 software and factor analysis were integrated to assess the children's comprehensive nutritional status and dietary structure. This study included 240 sex-matched (1:1) children aged 7-12years from KBD endemic (n=120) and non-endemic (n=120) areas. Overall, 720 solid food, 720 liquid, and 240 hair samples were collected for selenium determination. The mean selenium level in hair of children in endemic areas (0.38±0.16mg/kg) was significantly lower than that in children in non-endemic areas (0.56±0.28mg/kg, Z=-5.249, p<0.001). The dietary selenium intake of children in endemic areas was 40.0% lower than that in children in non-endemic areas (Z=-9.374, p<0.001). Children in endemic areas consumed significantly less diverse dietary items leading to significantly less intake of multiple nutrients compared to children in non-endemic areas. The dietary selenium intake of most children in endemic areas was less than the recommended amount. The dietary structure of children was undiversified, which limited the intake of multiple nutrients. Therefore, comprehensive nutrition rather than sole selenium intake should be the primary concern in the future.

The “Gandalf” soil sampling project at a former industrial site in Copenhagen, Denmark: evaluating soil classification reliability

Handling and transport of contaminated soil from industrial sites in Denmark requires classification based on concentrations of selected metals and organic contaminants. Reliable soil classification is needed for defensible remedial decision-making. Today’s sampling process in Denmark is based on grab sampling of prescribed standard volumes of soil; 30 tons is typically used as the basic sampling Decision Unit. Soil classification follows a number of varying systems, but classification into five classes (class 0 to class 4) based on analytical results from sub-samples of 50 g is the most common. In this study we investigate the sampling uncertainty obtained by sampling of &gt; 1800 samples at a former industrial site in Copenhagen, Denmark. The aim of the study was to conduct a critical assessment of the current sampling strategy by determination of soil classification errors obtained for duplicate primary samples collected from the same truck- load of soil, but with different distances from the original primary sample. It is also discussed which contaminants are the major parameters responsible for final soil classification designations. The original primary samples for the soil classification were taken at the centre of a 7 × 7 m grid for every 33 cm to a depth of 1 m or 3 m. In addition - for approximately half of the positions - samples were taken at a distance of 1, 2 or 3 m from the original sample. The classifications for the original samples were compared to the classifications for the additional samples in the same Decision Unit (7 × 7 × 0.33 m box) and from duplicate original samples. The results show that at least 50 % of all samples were misclassified, 20 % were mis-classified by two or more classes. This study demonstrates that the risk of misclassification is highest for less mobile parameters, metals and PAHs compared to the volatile organic solvents.

Understanding sampling variation – a vital aspect of industrial research experiments

Industrial research experiments are conducted in various scales in the mining industry. Regardless of the experimental purpose, sampling and analysis is normally always a part of the experimental process to collect necessary data. However, in order to ensure that the experiment will enable valid conclusions, the understanding and minimisation of sampling variation is crucial. Two effective methods for evaluation of sampling variability in any process sampling situation are the duplicate and replication experiments. The application of sampling experiments in the early phases of a demo- or pilot-scale experiment is an effective way to both understand the total measurement system variability, as well as the possibility to improve sampling methods if the sampling variability is deemed too high to enable representative results to use for experimental evaluation. LKAB is an iron ore mining company in the north of Sweden where experiments are conducted in all parts of the process value chain with regularity. In the current state of the world, encountering more and more threats to our global climate and environment, a focus for LKAB has been to reduce the use of fossil fuel as well as to minimize waste and tailings. One of LKABs current environmental initiatives is to investigate the feasibility of recovering and processing apatite from tailings of the LKAB beneficiation process. Further processing of recovered apatite will generate critical raw materials, phosphorous, rare-earth elements, and fluorine. To increase the understanding of the process variability of various analytical parameters in a pilot-scale experiment within this project, both duplicate and replication sampling experiments were conducted during one of the pilot-scale campaigns. The sampling experiments were applied to three separate sampling locations where two different sampling methods were used. Results show that both sampling method and sampling experimental method can affect the results obtained. The case study showed that the sampling variability was higher for sampling locations where grab sampling was applied, in comparison to composite sampling that generated lower sampling variability at one of the sampling locations in the pilot plant. This indicate that the composite sampling method can produce more representative results and should be favourable in future process experiments. The results also indicate that the duplicate sampling experiment is more robust to outliers in comparison to the replication experiment. The duplicate experiment is also able to quantify the process variability and evaluate the relative sampling to process variability which can be an advantage in some cases.

Implementation of a QAQC program for in-situ grade control by pulsed fast and thermal neutron activation methods

Following years of development and testing, in-situ chemical assay by Pulsed Fast and Thermal Neutron Activation (PFTNA) has been implemented in mining grade control at BHP Western Australian Iron Ore as a world first. Demonstrating the technical capability and aptness of a new methodology, however, is not sufficient to ensure the sustained quality of reported assay data. The success of moving from testing stage to implementation in active mining grade control, is chiefly dependent on the robustness of ongoing quality control and quality management. This paper shows the steps undertaken to achieve end to end monitoring of data acquired by Blasthole Assay Tools (BHAT) using PFTNA methods. The main challenge forin situ chemical assay by the BHAT is to design a quality assurance/quality control program (QA/QC) without a physical sample being collected, and in consequence, without the conventional separation into the focus areas sample collection, sample preparation and laboratory analysis. In this context, the BHAT combines all in one in-strument, and different ways to monitor data integrity, repeatability and accuracy need to be established as outlined below. After the validity of a BHAT calibration has been verified and a tool is in operation, data is monitored on a daily basis to check that relevant operational parameters inside the tool are working within defined acceptance limits. Measurement error in the field is monitored with repeat logs in Blastholes, and inter-instrument error by replicate logs of different BHAT units in the same Blastholes. Accuracy and instrument drift over longer periods are monitored by repeated logs in Reverse Circulation (RC) drill holes. Operational parameters, such as neutron output and spectral resolution of the instrument detector are monitored by scheduled logs in dedicated testing facilities. Also, duplicate manual sampling in Blastholes isused to compare grade populations obtained by different sampling methods in mining pits to aid grade reconciliation from mining to production. By routine application of these QA/QC steps, in conjunction with close communication of results to mining teams, the new BHAT technology has been successfully embedded in day to day mining operations.

Temporal patterns of plastic contamination in surface waters at the SS Yongala shipwreck, Great Barrier Reef, Australia

Plastic pollution is ubiquitous within the marine environment, including surface waters, water column and benthic sediments. Marine plastic contamination is expected to increase if future projections of increased plastic production eventuate. Conversely, national and international efforts are aiming to reduce marine plastic contamination. In this context, scientists, managers and the general public are increasingly interested in understanding the status and temporal trends of plastic contamination in the marine environment. Presented here is the first temporal assessment of plastic contamination in surface waters of the Great Barrier Reef (GBR), Australia. Specifically, duplicate surface seawater samples (n = 66) were collected at the SS Yongala shipwreck (Central GBR) monthly from September 2016 to September 2019 and analysed for plastic presence and abundance. The processing workflow involved density separation, followed by filtration, visual identification and sizing of putative plastics using stereomicroscopy, and chemical characterisation using Fourier transform infrared spectroscopy. A total of 533 plastic items were identified across all tows, consisting of macro-, meso- and microplastic fragments and fibres, with polypropylene and polyethylene being the most common polymers. Plastic contamination was detected in every replicate tow, bar one. Plastic concentrations fluctuated and spiked every three months, although contamination did not significantly alter across the three-year period. Wind speed, salinity and river discharge volume, but not surface current speed nor sea surface temperature, had a significant influence on the levels of plastic contamination. This study reveals, for the first time, the chronic presence of plastic debris in the surface waters of the GBR highlighting the need for long-term and on-going monitoring of the marine environment for plastic contamination.

Evaluation of the stability of temocillin in elastomeric infusion devices used for outpatient parenteral antimicrobial therapy in accordance with the requirements of the UK NHS Yellow Cover Document

ObjectiveTo evaluate the stability of temocillin solution in two elastomeric infusion devices – Easypump II LT 270–27- S and Dosi-Fusor L25915-250D1 for OPAT administration during 14 days of 5°C±3°C fridge...

Characterization of Avocado Improved Creole Varieties of Nuevo León, México

The avocado is native to central and eastern Mexico, and the highlands of Guatemala. Three races of avocado are recognized: the Mexican race (Persea americana var. drymifolia), the Guatemalan race (Persea americana var. guatemaltensis) and the Antillean race (Persea americana var. americana). The state of Nuevo León is part of the primary center of origin for P. americana var. drymifolia, where the varieties used have been selected by the producers based on their production, quality and size of the fruit. These cultivars are grafted trees with genotypes of interest called “Improved Creole Varieties”. In this study, some characteristics of a group of these varieties are presented. Collection of the fruits for their characterization was carried out in commercial Creole avocado orchards under irrigation conditions in the municipalities of Aramberri and Zaragoza in the southern region and in Sabinas Hidalgo and Bustamante in the northern region of the state of Nuevo León. A duplicate sample of ripe avocado fruits of ten genotypes was evaluated. The following characteristics of ripe fruits were determined: total oil content, fruit and seed weight, fruit shape, skin and pulp color when ripe, skin appearance and texture, etc. A great diversity was detected in the characteristics evaluated in the improved native varieties of avocado, highlighting the importance in its preservation and use of the diversity of Creole avocados cultivated in Nuevo León. Key words: diversity, oil content, fruit weight

Assessing Salmonella prevalence and complexity through processing using different culture methods

Conventional Salmonella surveillance requires a week for isolation, confirmation, and subsequent serotyping. We previously showed that this could be reduced by 24 h by combining the pre-enrichment and enrichment steps into a single selective pre-enrichment step and was tested on directly after picking. The goal of this study was 2-fold: 1) to evaluate the use of selective pre-enrichment through each step of processing, including postintervention when the Salmonella load is reduced, and 2) to assess any changes in serovar populations in Salmonella positive samples. Duplicate carcass drip samples, each representative of 500 broiler carcasses, were collected by catching processing water drip under moving carcass shackle lines in each of three commercial broiler slaughter plants. Samples were collected post-pick, post-inside-outside bird wash (IOBW), and post-chill; duplicate wing rinses were performed pre- and post-antimicrobial parts dip. Each processing plant was sampled 6 times for a total of 180 samples collected. The number of Salmonella positives identified with selective pre-enrichment conditions (48/180) was similar to traditional selective enrichment culture conditions (52/180), showed good concordance in recovery rate between the 2 culture methods (Fisher's exact test, P = 0.72). We also found that the incidence of Salmonella reduced dramatically after antimicrobial intervention (post-pick 66.7% vs. post chill 8.3%). When serovar populations were evaluated in Salmonella positive samples using CRISPR-SeroSeq, we detected four different Salmonella serovars, Kentucky, Infantis, Schwarzengrund, and Typhimurium, and their incidence rose between post-pick and post-IOBW. The relative abundance of Infantis within individual samples increased between post-pick and post-IOBW while the relative abundance of the other 3 serovars decreased. These results suggest that a selective pre-enrichment step reduces the time required for Salmonella isolation without negatively affecting detection and serovar profiles in culture positive samples were not altered between culture conditions used.

Evaluation of acquisition modes for semi-quantitative analysis by targeted and untargeted mass spectrometry.

RationaleAnalyte quantitation by mass spectrometry underpins a diverse range of scientific endeavors. The fast‐growing field of mass spectrometer development has resulted in several targeted and untargeted acquisition modes suitable for these applications. By characterizing the acquisition methods available on an ion mobility (IM)‐enabled orthogonal acceleration time‐of‐flight (oa‐ToF) instrument, the optimum modes for analyte semi‐quantitation can be deduced.MethodsSerial dilutions of commercial metabolite, peptide, or cross‐linked peptide analytes were prepared in matrices of human urine or Escherichia coli digest. Each analyte dilution was introduced into an IM separation‐enabled oa‐ToF mass spectrometer by reversed‐phase liquid chromatography and electrospray ionization. Data were acquired for each sample in duplicate using nine different acquisition modes, including four IM‐enabled acquisitions modes, available on the mass spectrometer.ResultsFive (metabolite) or seven (peptide/cross‐linked peptide) point calibration curves were prepared for analytes across each of the acquisition modes. A nonlinear response was observed at high concentrations for some modes, attributed to saturation effects. Two correction methods, one MS1 isotope‐correction and one MS2 ion intensity‐correction, were applied to address this observation, resulting in an up to twofold increase in dynamic range. By averaging the semi‐quantitative results across analyte classes, two parameters, linear dynamic range (LDR) and lower limit of quantification (LLOQ), were determined to evaluate each mode.ConclusionA comparison of the acquisition modes revealed that data‐independent acquisition and parallel reaction monitoring methods are most robust for semi‐quantitation when considering achievable LDR and LLOQ. IM‐enabled modes exhibited sensitivity increases, but a simultaneous reduction in dynamic range required correction methods to recover. These findings will assist users in identifying the optimum acquisition mode for their analyte quantitation needs, supporting a diverse range of applications and providing guidance for future acquisition mode developments.

Volatilisation of selenium from coals by heating at different temperature: application of sequential extraction scheme on ash

ABSTRACT An important issue to the earth’s atmosphere is the volatilisation of elements such as selenium, from the burning of coal at different temperatures. In the current work, the volatilisation of selenium (Se) during combustion of coal samples at different control temperature range in an electrically controlled furnace was carried out. The coal samples were obtained from various coal fields of Sindh, Pakistan. The duplicate coal samples were combusted in controlled furnace by applying three temperature rounds (200°C, 400°C and 900°C). The ash formed following each temperature round was examined to know the volatilisation contents of Se after burning of coal samples at different temperature. The fractionation of Se in coal ash gained after combustion at 900°C was subjected to three-stage sequential extraction scheme (SES). The obtained data indicated that the total contents of Se in coal samples of block II of Thar coal field (TCF), and Site I and Site II of Lakhra coal field (LCF) were observed in the range of 7.72–14.3, 9.02–16.3 and 8.92–14.2 mg/kg, respectively. It was observed that after the burning of coal samples at 900°C, about 75–81.8% of the total Se was volatised out into atmosphere.

P263. Actigraphically Measured Slowing in Depression – A Meta-Analysis

Psychomotor slowing is a key feature in depressive disorders. Meta-analyses have synthesized studies examining actigraphically measured slowing in unipolar and bipolar depression with several limitations, such as missing studies, lack of rigorous criteria for diagnoses, or exclusion of duplicate samples. Following PRISMA guidelines, we conducted a novel meta-analysis on actigraphically measured slowing in depression with strict inclusion/exclusion criteria for diagnosis ascertainment and sample duplications.

Diurnal Variability of SARS-CoV-2 RNA Concentrations in Hourly Grab Samples of Wastewater Influent during Low COVID-19 Incidence.

Wastewater-based epidemiology (WBE) has been widely deployed during the COVID-19 pandemic, but with limited evaluation of the utility of discrete sampling for large sewersheds and low COVID-19 incidence. In this study, SARS-CoV-2 RNA was measured in 72 consecutive hourly influent grab samples collected at a wastewater treatment plant serving nearly 500 000 residents when incidence was low (approximately 20 cases per 100 000). We characterized diurnal variability and relationships between SARS-CoV-2 RNA detection and physicochemical covariates [flow rate, total ammonia nitrogen (TAN), and total solids (TS)]. The highest detection rate observed was 82% during the first peak flow, which occurred in the early afternoon (14:00). Higher detection rates were also observed when sampling above median TAN concentrations (71%; p < 0.01; median = 40.26 mg of NH4/L). SARS-CoV-2 RNA concentrations were weakly correlated with flow rate (Kendall’s τ = 0.16; p < 0.01), TAN (τ = 0.19; p < 0.05), and TS (τ = 0.18; p < 0.01), suggesting generally low RNA sewer discharges as expected at low incidence. Our results elucidated sensible adjustments to maximize detection rates, including using multiple gene targets, collecting duplicate samples, and sampling during higher flow and TAN discharges. Optimizing the lower-incidence bounds of WBE can help assess its suitability for verifying COVID-19 reemergence or eradication.