Low-level Contamination Research Articles

Levels of Lead in Residential Drinking Water and Iron Deficiency among Patients with End Stage Kidney Disease.

Although those with kidney disease may have heightened susceptibility to heavy metal toxicity, whether low levels of drinking water lead contamination have clinical consequence is unknown. Given that lead toxicity is known to associate with iron deficiency, we merged data from the Environmental Protection Agency (EPA) Safe Drinking Water Information and United States Renal Data Systems to examine whether municipal 90th percentile drinking water lead levels associate with iron deficiency among incident dialysis patients. Iron deficiency was defined across thresholds of transferrin saturation (<10% and 20%) and ferritin (<100 and <200 ng/ml), and simultaneous transferrin saturation <20% and ferritin <200 ng/ml, all obtained within 30 days of dialysis initiation. The average 90th percentile of drinking water lead samples per patient city of residence over a 5-year period before dialysis initiation was examined at the <1 μg/L level of detection, and at the 25th, 50th, and 100th percentile of the EPA's actionable level (15 μg/L). Among 143,754 incident ESKD patients, those in cities with drinking water lead contamination had 1.06 (95% CI, 1.03 to 1.09), 1.06 (95% CI, 1.02 to 1.10), and 1.07 (95% CI, 1.03 to 1.11) higher adjusted odds of a transferrin saturation <20%, ferritin <200 ng/ml, and simultaneous transferrin saturation <20% and ferritin <200 ng/ml, respectively. These associations were apparent across the range of lead levels found commonly in the United States and were significantly greater among Black patients (multiplicative interaction P values between lead and race <0.05). Even exposure to low levels of lead contamination, as commonly found in US drinking water, may have adverse hematologic consequence in patients with advanced kidney disease. These associations are particularly evident among Black people and, although consistent with other environmental injustices facing minorities in the United States, might reflect a greater susceptibility to lead intoxication.

Virulence and antimicrobial-resistance of shiga toxin-producing E. coli (STEC) Isolated from edible shellfish and its public health significance

Shiga toxin-producing E. coli (STEC) are an important cause of foodborne illness in humans with infections ranging from mild non-bloody diarrhea to bloody diarrhea (BD) and hemolytic uremic syndrome (HUS). This study aimed to investigate the distribution of STEC in shellfish from coastal shores of Lake Timsah in Ismailia Governorate, Egypt and its probable hazard to seafood consumers. Samples from the external surface and tissues of shrimp (n = 45), crabs (n = 45), and oysters (n = 45) batches were examined bacteriologically for the presence of STEC and tested for their antibiotic sensitivity. Moreover, occurrence of virulence genes was determined via detection of stx1, stx2 and eaeA genes using PCR. Overall, E. coli and presumptive STEC isolates (from CHROMagar) were identified from the surface (55.6 and 5.9%) and tissues (42.2 and 8.9%) of the examined shellfish batches, respectively. Five STEC isolates had been confirmed and found belonging to O26:H11, O125:H6, O146:H21, and O159 serogroups, those were 4 isolates from tissues of the three shellfish species and one isolate from the crab surface. The STEC isolates were multi-drug resistant, showing complete resistance to; penicillins, amoxycillin/clavulanic acid, colistin, fosfomycin, ceftriaxone, ciprofloxacin, and tetracycline, however, they were sensitive to gentamycin except O159 serogroup. The current study revealed low level of contamination of shellfish from coastal shores of Lake Timsah with STEC, however, it also highlights the extreme level of antimicrobial resistance exhibited by the presumptive and confirmed STEC isolates which is very hazardous for seafood consumers in the study area.

504 “Chimeric sorting” as an effective tool for selection of genetically modified dermal fibroblasts to be used in fundamental or applied skin research

A technology has been developed for efficient isolation of a stable pool of HIF1a overexpressing mouse fibroblasts using a high-throughput selection of cell clones on a cellulose carrier. The pHIF1a-CBD-PDGFR genetic construct has been generated containing a EYFP reporter, a target sequence of HIF1a gene (a key factor of adaptation to hypoxia in wound healing and regeneration) and a CBD/PDGFR chimeric gene construct. The presence of CBD (cellulose-binding domain) / PDGFR (platelet-derived growth factor receptor) chimeric construct in protein-producing cells enables their specific binding to cellulose carrier thus providing a possibility for cell selection based on their adhesive phenotype (“chimeric sorting”). For genetic modification, a line of immortalized postnatal mouse dermal fibroblasts was used (dp3T3cell line). This cell line has been developed using 3T3 protocol and combines the basic features of primary dermal fibroblasts with the experimental advantages of immortal cells. The high-throughput selection of HIF1a overexpressing cells was performed using BD FACSAria™ Fusion Cell Sorter (with EYFP as a reporter) or by chimeric sorting on day 5th after dp3T3 cell transfection (electroporation) using half of transfected cells for each approach (0.9±0.2x10ˆ6). The CBD-PDGFR driven chimeric sorting was performed on cellulose filter papers, 75g/cm2. In 3 weeks chimeric sorting allowed to obtain 3±1x10ˆ6 stably transfected cells with changed morphology (less stellate and more elongate), while FACS sorting yielded 8 colonies with 0.6±0.3x10ˆ5 cells each with only 3 colonies exhibiting modified phenotype. Thus, “chimeric sorting” of transfected fibroblasts on a cellulose carrier appeared to be more effective in selection of HIF1a overexpressing cells as compared to conventional FACS. The advantageous efficiency of this approach was reflected in both its specificity (low level of contamination with cells of original phenotype) and its productivity (higher yield of stably transfected cells).

Time to evaluate decision support systems for antimicrobial prescribing outside the hospital

Time to evaluate decision support systems for antimicrobial prescribing outside the hospital

Land Recovery and Soil Management with Agroforestry Systems

Soils have many ecological functions and provide various ecosystem services including support for global food and fuel production. However, FAO reports indicate that approximately one-third of the planet’s arable lands show levels of degradation from processes including soil erosion, low levels of nutrients, acidification, salinization, compaction, sealing, and contamination. These conditions are also found in Brazil where soil degradation is largely caused by inadequate land management. Worldwide, strategic policies have been presented to mitigate this problem, with emphasis on sustainable agriculture. Among them, agroforestry has been identified as a viable system for mitigating and recovering degraded areas. Agroforestry techniques have been developed and tested but are still not understood by farmers, due to their complexity. This study aimed to analyze experiences and studies with agroforestry reported from Australia, some countries in Africa, and Brazil to search for similarities in these complex systems and identify possible correlations to support the hypothesis that land recovery can be enhanced through soil management using agroforestry. A Sankey diagram was developed to illustrate relationships among problems, the adoption of agroforestry and improvements, and the most important contributions. Data analysis shows that the main problems related to soil degradation are soil erosion and decreased soil fertility, while the adoption of agroforestry systems proved to improve different aspects of soil quality and to be a safe path to sustainable agricultural production. To obtain more information on the adoption of these systems in different locations, soils, and climates, it is important to implement policies for reducing land degradation. Furthermore, the assessment of the economic, environmental and social benefits of improving soil fertility and decreasing erosion in agroforestry systems is necessary to validate the use of agroforestry as a sustainable agricultural practice.

Distribution, risk assessment, and source identification of trace metal pollution along the Babolsar coastal area, Caspian Sea.

The Caspian Sea is exposed to numerous anthropogenic activities such as untreated wastewater discharge and agricultural activities which increased trace metals contamination. The current study was employed to assess the distribution, ecological risk assessment, and source identification of some trace metals in 125 samples of surface sediments and soil from 6 distinctive sections of Babolsar in the coastal line of the Caspian Sea. The sediment quality guidelines (SQGs) and individual risk assessment indices including enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (Cf), and potential risk factor (Er) suggested a hazardous level of Cd and Cr contamination. There was a relatively high level of Pb contamination while other studied trace metals were at a low contamination level. Cumulative risk indices such as modified degree of contamination (mCD), pollution load index (PLI), and the potential ecological risk index (RI) identified that the river, wetland, and farmland sites were more contaminated compared to the Caspian Sea samples which exhibited a moderate level of contamination. The lowest level of contamination was recorded in the coastline and river delta sites. Two analytical methods including Pearson's correlation coefficient and multivariate clustering dendrogram were also applied to identify the potential sources of contamination. The results suggested that wastewaters, nitrogen, and phosphate fertilizers were the main anthropogenic source of Cd, Co, Pb, and Ni while fossil fuels and transportation activities were the predominant sources of anthropogenic Cu, V, and Zn contamination. Further studies about trace metals risk assessment and fractionation could contribute to more effective decisions for reducing the anthropogenic trace metal pollution in the Caspian Sea.

Analysis of Colostrum and Udder Skin Swabs from a Dairy Goat Herd in Germany regarding the Occurrence of Mycobacterium avium Subsp. paratuberculosis.

Simple SummaryThe analysis of transmission routes for paratuberculosis as well as their prevention are critical for effective disease control. The aim of the present study was to assess the importance of colostrum and the udder skin as routes for transmission of Mycobacterium avium subspecies paratuberculosis (MAP) within a dairy goat herd. Swabs of the udder skin and colostrum samples were collected from goats of a paratuberculosis-infected herd during lambing season and analyzed for MAP DNA. Additionally, cultivation of the swabs was performed. MAP could not be detected in the colostrum. A low number of udder skin swabs was positive for MAP DNA but no bacteria could be cultured. Because the detection methods are imperfect, the occurrence of MAP in colostrum or on the udder skin can never be completely excluded. Therefore, present recommendations concerning colostrum and youngstock management should still be re-evaluated, but applied in goat herds within a paratuberculosis control program until the role of colostrum and udder skin for within-herd transmission of MAP is further investigated.Oral intake of Mycobacterium avium subspecies paratuberculosis (MAP) in first days of life is considered to be the main route of infection for paratuberculosis. This can be related to a direct contact to contaminated feces or feeding of MAP containing colostrum. Colostrum is believed to become contaminated either by lactogenic shedding or introduction of MAP from environmental sources. In this pilot study, the presence of MAP in individual and bulk colostrum samples from a paratuberculosis-infected, vaccinated dairy goat herd in Germany and the effect of udder skin disinfection on the MAP load of colostrum were examined. In order to distinguish between lactogenic shedding and fecal contamination, 49 udder skin swabs were cultivated on solid medium whereas 29 swabs were additionally analyzed by qPCR. qPCR was applied on 110 individual colostrum samples collected from 55 goats, one before and one after disinfection with a mycobactericidal disinfectant, and 14 bulk colostrum samples. MAP DNA was detected in 10.3% (3/29) of the swab samples, but no viable MAP was cultivated from any sample. These results indicate a low-level MAP contamination of the udder skin and colostrum of milking goats suggesting a low risk of MAP transmission via these routes.

Survey of the Presence of Nivalenol and Deoxynivalenol in Wheat Flour Factories of Khuzestan Province, Iran

Background: Wheat is frequently contaminated by Deoxynivalenol (DON) and Nivalenol (NIV), which are type B trichothecenes produced by Fusarium fungi. Most problems related to these contaminants involve prolonged feed intake at low levels of contamination. This study investigated the occurrence of NIV and Deoxynivalenol (DON) in wheat flour in flour factories in Khuzestan Providence, Iran. Methods: In total, 104 samples were collected in this study. An acetonitrile/water mixture (84:16, v/v) was used to extract the samples. The extracts were filtered and purified using a Whatman No. 4 paper and MycoSepTM 227 column. Then, they were evaporated to dryness at 40˚C under a nitrogen stream. After dissolving the dry residue in the mobile phase, containing a mixture of methanol, acetonitrile, and water (5:5:90, v/v/v), the contents of NIV and DON in the samples were measured in High-Performance Liquid Chromatography (HPLC) system with a column C18 (150 mm×4.6 mm ID, 5 μm) and a UV detector (220 nm). Results: The results showed that among 104 wheat flour samples, 28 (26.8%) and 54 (51.9%) samples were contaminated with NIV and DON, respectively. The mean and maximum concentrations were 118.75 and 2278 ng/g for NIV, and 593 and 67.88 ng/g for DON, respectively. Conclusion: Based on the findings, DON and NIV had significantly lower concentrations than the maximum tolerated level (1 μg/g), established by the Institute of Standards and Industrial Research of Iran. Therefore, there were no health risks for consumers at the studied contamination levels.

A Comparative Study to Determine the Nutritive Value of National Brands and Locally Baked Cookies, Detection of Aflatoxin B1 and Aflatoxigenic Fungi in Quetta

It’s worthy to get knowledge about the nutritional value of the food which is being consumed by people so far. Various forms of malnutrition are the reason of suffering for millions of the people in each corner of the world. Biscuits have got popularity in Pakistani culture. They are being baked locally and well-known brands are also its suppliers. Nutritional value of local biscuits is still unknown. The aim of the study was to analyze proximate value of local biscuits and branded biscuits, their comparison and determination of rancidity, AFB1 and aflatoxigenic fungi as they prevail in wheat products and peanuts. So, 16 local biscuits samples and 16 branded biscuit samples were selected for analysis. AOAC methods were used for proximate analysis, TLC for AFB1 detection. Proximate analysis showed local biscuits have following mean values for: protein 12.01%, ether extracts 26.625, crude fiber 1.25%, moisture 40.28%, and ash 0.52%. On the other hand, mean value of protein was observed 7.47%, ether extracts 22.26%, crude fiber 0.89%, moisture 2.66%, and ash 0.56% in the branded biscuits. Rancidity of branded biscuits was having mean value 0.39 mEq and locally baked biscuits were having 0.55 mEq but both were able to consume. So, it shows local biscuits are good source of nutrition and fit for consumption for all the ages. In local biscuit samples 87.5% had low contamination level and 12.50% samples had medium level. In contrast, no branded sample has crossed the permissible limit of AFB1 and aflatoxigenic fungi was detected in none of the sample.

Ambulance sanitation in Italy: a pilot study

Abstract&#x0D; Introduction: the assessment of biological agents' exposure in the work environment is an employer's duty. Air and surfaces could be transmission's vehicles of pathogens. We consider the ambulance as the work environment where, respecting hygienic targets of low risk, we can prevent out-of-hospital infections for workers and patients. Our study analyzes standard sanitation and fumigation; the aim is to reach the lower level of surfaces' contamination. &#x0D; Materials and Methods: we chose, thanks to bibliography, three points of sampling: stretcher, oxygen knob and backdoor's handle. The points were tested before sanification on three different ambulances. We made thus standard sanitation with Sodium Hypochlorite on two ambulances and fumigation on the other one. After that, we sampled the same three points on each ambulance. Samples were analyzed with standard culture methods after 72 hours. &#x0D; Results: first samples showed a high bacterial load on every surface. Both standard sanification and fumigation showed success in decreasing bacterial load. Without approved rating standards for ambulance's hygiene we refer to ISPESL's Guidelines about safety and hygiene in surgical wards. Here the standard is 50 cfu/sample, referred to a surface of 20 cm², without pathogens. &#x0D; Discussion and Conclusions: our analysis is just quantitative, further qualitative analysis should be conducted in order to assess pathogens on ambulances. Both standard sanitation and fumigation show success in decreasing bacterial load however with higher levels than those indicated by guidelines. Further analysis would be needed to define load standards in order to ensure a safe environment for workers and patients.

COVID-19 dispersion in naturally-ventilated classrooms: a study on inlet-outlet characteristics

Infectious aerosol dispersion poses significant infection risks (i.e., COVID-19) in classrooms due to dense and long occupancy. Natural ventilation is an effective strategy to reduce airborne infection transmission. The building-related parameters, particularly openings, determine the natural ventilation effectiveness in reducing contaminant dispersion, necessitating an inquiry due to complex dispersion and airflow patterns. This paper investigates the correlation between window height, natural ventilation, and COVID-19 dispersion. A simulation pipeline involving a parametric 3D design environment, computational fluid dynamics (CFD), and energy simulations is developed and implemented on nine design scenarios representing different inlet-outlet heights of a free-running (no heating, cooling or mechanical ventilation) classroom. The inlet height and the inlet-outlet height difference have a considerable impact on indoor infection risk confirming that stack ventilation and the Bernoulli effect decrease indoor contaminant concentration. Proximity to openings does not ensure lower contamination levels. Proximity to the contaminant does not result in higher contamination levels.

A Sustainable Decision Support System for Drinking Water Systems: Resiliency Improvement against Cyanide Contamination

Maintaining drinking water quality is considered important in building sustainable cities and societies. On the other hand, water insecurity is an obstacle to achieving sustainable development goals based on the issues of threatening human health and well-being and global peace. One of the dangers threatening water sources is cyanide contamination due to industrial wastewater leakage or sabotage. The present study investigates and provides potential strategies to remove cyanide contamination by chlorination. In this regard, the main novelty is to propose a sustainable decision support system for the dirking water system in a case study in Iran. First, three scenarios have been defined with low ([CN−] = 2.5 mg L−1), medium ([CN−] = 5 mg L−1), and high ([CN−] = 7.5 mg L−1) levels of contamination. Then, the optimal chlorine dosage has been suggested as 2.9 mg L−1, 4.7 mg L−1, and 6.1 mg L−1, respectively, for these three scenarios. In the next step, the residual cyanide was modelled with mathematical approaches, which revealed that the Gaussian distribution has the best performance accordingly. The main methodology was developing a hybrid approach based on the Gaussian model and the genetic algorithm. The outcomes of statistical evaluations illustrated that both injected chlorine and initial cyanide load have the greatest effects on residual cyanide ions. Finally, the proposed hybrid algorithm is characterized by the multilayer perceptron algorithm, which can forecast residual cyanide anion with a regression coefficient greater than 0.99 as a soft sensor. The output can demonstrate a strong positive relationship between residual cyanide- (RCN−) and injected chlorine. The main finding is that the proposed sustainable decision support system with our hybrid algorithm improves the resiliency levels of the considered drinking water system against cyanide treatments.

Assessing multiple fecal sources to surf zone waters of two recreational beaches by bacterial community analysis

Fecal sources to recreational surf zone waters should be identified to protect public health. While watershed origins of human and other fecal sources are often discoverable by quantitative polymerase chain reaction (qPCR) of fecal markers using spatially stratified samples, similarly assessing wastewater treatment plant (WWTP) outfall and other offshore contributions to surf zones is challenged by individual marker fate and transport. Here, bacterial communities were assessed for relatedness between all hypothesized fecal sources and surf zone waters for two urban California recreational beaches, by sequencing genes encoding 16S rRNA and analyzing data using SourceTracker and FEAST. Ambient marine bacterial communities dominated the surf zone, while fecal (human, dog, or gull) or wastewater (sewage or treated WWTP effluent) bacterial communities were present at low proportions and those from recycled water were absent. Based on the relative abundances of bacterial genera specifically associated with human feces, the abundances of HF183 in bacterial community sequences, and FEAST and SourceTracker results when benchmarked to HF183, the major sources of HF183 to surf zone waters were human feces and treated WWTP effluent. While surf zone sequence proportions from human sources (feces, sewage and treated WWTP effluent) appeared uncorrelated to previously obtained qPCR HF183 results, the proportions of human fecal and potential human pathogen sequences in surf zone waters were elevated when there were more swimmers (i.e. during weekday afternoons, holidays and busy weekends, and race events), thus confirming previously-published qPCR-based conclusions that bather shedding contributed low levels of human fecal contamination. Here, bacterial community sequencing also showed evidence that treated WWTP effluent from an offshore outfall was entering the surf zone, thereby resolving a prior uncertainty. Thus, bacterial community sequencing not only confirms qPCR HF183-based human marker detections, but further allows for confirming fecal sources for which individual marker quantification results can be equivocal.

Genome-Resolved Characterization of Structure and Potential Functions of the Zebrafish Stool Microbiome.

Zebrafish have been used as a model organism for more than 50 years and are considered an excellent model for studying host-microbiome interactions. However, this largely depends on our understanding of the zebrafish gut microbiome itself. Despite advances in sequencing and data analysis methods, the zebrafish gut microbiome remains highly understudied. This study performed the de novo metagenome assembly and recovery of the metagenome-assembled genomes (MAGs) through genome binning (and refinement) of the contigs assembled from the zebrafish stool. The results indicate that majority of the MAGs had excellent quality i.e. high completeness (≥90%) and low contamination levels (≤5%). MAGs mainly belong to the taxa that are known to be members of the core zebrafish stool microbiome, including the phylum Proteobacteria, Fusobacteriota, and Actinobacteriota. However, most of the MAGs remained unclassified at the species level and reflected previously unexplored microbial taxa and their potential novelty. These MAGs also contained genes with predicted functions associated with diverse metabolic pathways that included carbohydrate, amino acid, and lipid metabolism pathways. Lastly, we performed a comparative analysis of Paucibacter MAGs and reference genomes that highlighted the presence of novel Paucibacter species and enriched metabolic potential in the recovered MAGs.

Poly-l-lactic acid (PLLA)/anthocyanin nanofiber color indicator film for headspace detection of low-level bacterial concentration

Since bacterial contamination is a significant threat to humans, early detection is essential to safeguard dietary safety and physical health. Here, a nanofiber color indicator film based on poly-l-lactic acid (PLLA) as the support and anthocyanin as the indicator material was prepared by electrostatic spinning. It was found that the PLLA/0.8CY nanofiber color indicator film was hydrophobic (the water contact angle of 102.4°) and contained uniform nanofibers with an average diameter of 750 nm. In addition, the film's humidity insensitivity, reusability, color stability, and ammonia sensitivity (the limits of detection 35.39 ppm) made the film environmentally friendly and more accurate and faster for bacterial detection. The film was able to sense 102 CFU/mL of gram-positive and negative bacteria after the model strain E. coli and L. monocytogene. Thus, the PLLA/0.8CY nanofiber color indicator film was able to perform headspace nondestructive detection of low-level bacterial contamination.

Method development and application to sediments for multi-residue analysis of organic contaminants using gas chromatography-tandem mass spectrometry.

A method for the determination of four classes of potentially toxic substances (PTSs) was developed and applied in marine sediments, including (i) polycyclic aromatic hydrocarbons (PAHs), (ii) polychlorinated biphenyls (PCBs), (iii) polybrominated diphenyl ethers (PBDEs), and (iv) organochlorinated pesticides (OCPs). The method is based on ultrasonic extraction with a mixture of dichloromethane:methanol (9:1 v/v) and gas chromatography coupled with tandem mass spectrometry analysis (GC-MS/MS) in multiple reaction monitoring (MRM) mode. A total of 89 compounds were identified using two precursor-product ion standards for each analyte. The method detection limit (MDL; 0.001-0.055ngg-1 dw) and method quantification limit (MQL; 0.002-0.184ngg-1 dw) are below the usual thresholds of pollution adopted by international sediment quality guidelines. The method proved to be selective, sensitive, accurate, and linear, with the advantage of reducing sample handling time and consumable expenses (solvent, adsorbents). The developed method was successfully applied to surface sediments of Sepetiba Bay, Rio de Janeiro State, Brazil. Total concentrations of PAH (29.20-209.5ngg-1 dw), PCB (0.06-2.16ngg-1 dw), OCP (0.03-0.33ngg-1 dw), and PBDE (0.06-0.21ngg-1 dw) represent a baseline for these compounds and revealed mild to low levels of contamination in comparison to other coastal bays in SE Brazil. By using the proposed method, we expect this preliminary dataset can be expanded and include other similar coastal systems from developing countries marked by scarcity of information about levels, risk assessment, and specific sediment quality guidelines encompassing multiple classes of regulated and emerging organic contaminants.

An in vitro model of microbial contamination in the operating room.

Infection associated with tissue-contacting biomedical devices is a compelling clinical problem initiated by the microbial colonization of the device surface. Among the possible sources of contaminating bacteria is the operating room (OR) itself, where viable bacteria in the atmosphere can sediment onto a device surface intraoperatively. We have developed an aerosolizing system that can reproducibly spray small quantities of aerosolized bacteria onto a surface to mimic OR contamination. This paper describes the design of the system and characterizes key aspects associated with its operation. The area density of sprayed bacteria is on the order of 102 /cm2 . Using titanium (Ti) alloy coupons as test substrates contaminated by staphylococci, we quantify the fraction of bacteria that are well adhered to the substrate, those that can be removed by sonication, and those that are not recovered after spraying. Despite the relatively low levels of surface contamination, we furthermore show that such a model is able to demonstrate a statistically significant reduction in colonization of Ti coupons modified by antimicrobial quaternary ammonium compounds relative to unmodified controls.

Maize response to localized mineral or organic NP starter fertilization under different soil tillage methods

An early maize (Zea mays L.) sowing date plays a key role in increasing the grain yield, especially in a temperate climate. The adoption of reduced tillage techniques, such as strip tillage (ST), can decrease cultivation costs, compared to plowing (PLOW), but might also reduce the crop early development rate as a result of lower soil temperatures. Therefore, farmers often adopt starter fertilizations when sowing maize, in order to improve the early-season nutrient uptake, nutrient use efficiency and plant development. The aims of this study were to assess the effects of the adoption of ST, compared to PLOW, and a starter fertilization with deep-injected digestate (DIG) or sub-surface placed diammonium phosphate (DAP), compared to an unfertilized treatment (NT) on the early growth, grain yield and grain qualitative and sanitary traits of maize. Field experiments were carried out in NW Italy over the 2019 and 2020 growing seasons on two different soils. ST determined cooler soil conditions at both sites, compared to PLOW, thus resulting in lower NDVI values due to both slower plant development and lower final crop density. The starter fertilization with DAP recorded the best early vigor and canopy development, expressed as plant height in both sites and for both tillage techniques, while the DIG values were intermediate between the DAP and NT treatments. Although the effects on the early vigor of maize differed between the experimental sites, displaying more pronounced differences in the finer-textured soil, ST on average delayed the flowering (+2.2 days) and consequently delayed the moisture dry down process (+1.2% grain moisture content at harvest), compared to PLOW. The starter fertilization with DIG or DAP led to an earlier flowering, compared to NT (−2.6 and −4.6 days, respectively). The grain yield was not affected by the tillage system, as the plants in ST compensated for the lower plant density with an increased ear length (+1.5%). Instead, DIG and DAP recorded similar and higher grain yields (+1.8 and +1.6 Mg ha−1) than NT. DIG application led to a higher grain protein content and lower level of fumonisin contamination than the other treatments, while ST determined higher deoxynivalenol values than PLOW. The combination of ST and DIG as a starter fertilization can help maintain the production level and the grain quality, compared to conventional techniques that involve the use of mineral fertilizers and plowing, thereby leading to a higher sustainability of the maize cropping system.

Probing the Thermodynamics of Biomagnification in Zoo-Housed Polar Bears by Equilibrium Sampling of Dietary and Fecal Samples.

In a proof-of-concept study, we recently used equilibrium sampling with silicone films to noninvasively derive the thermodynamic limit to a canine’s gastrointestinal biomagnification capability (BMFlim) by determining the ratio of the products of the volume (V) and fugacity capacity (Z) of food and feces. In that earlier study, low contaminant levels prevented the determination of contaminant fugacities (f) in food and feces. For zoo-housed polar bears, fed on a lipid-rich diet of fish and seal oil, we were now able to measure the increase in f of nine native polychlorinated biphenyls (PCBs) upon digestion, providing incontestable proof of the process of gastrointestinal biomagnification. A high average BMFlim value of ∼171 for the bears was caused mostly by a remarkable reduction in fugacity capacity driven by a high lipid assimilation capacity. Lipid-rich diets increase the uptake of biomagnifying contaminants in two ways: because they tend to have higher contaminant concentrations and because they lead to a high Z value drop during digestion. We also confirmed that equilibrium sampling yielded similar Z values for PCBs originally present in food and feces and for isotopically labeled PCBs spiked onto those samples, which makes the method suitable for investigating the biomagnification capability of organisms, even if native contaminant concentrations in their diet and feces are low.

Environmental contamination by Chlamydia trachomatis and Neisseria gonorrhoeae: is it time to change our infection control practices? Results of a regional study

ObjectivesNucleic acid amplification tests (NAATs) are highly sensitive for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) DNA/ribosomal RNA (rRNA). Previous studies have demonstrated contamination of surfaces in...