Estimation of baseline levels of bacterial community tolerance to Cr, Ni, Pb, and Zn in unpolluted soils, a background for PICT (pollution-induced community tolerance) determination

The PICT method (pollution-induced community tolerance) can be used to assess whether changes in soil microbial response are due to heavy metal toxicity or not. Microbial community tolerance baseline levels can, however, also change due to variations in soil physicochemical properties. Thirty soil samples (0–20 cm), with geochemical baseline concentrations (GBCs) of heavy metals and from five different parent materials (granite, limestone, schist, amphibolite, and serpentine), were used to estimate baseline levels of bacterial community tolerance to Cr, Ni, Pb, and Zn using the leucine incorporation method. General equations (n = 30) were determined by multiple linear regression using general soil properties and parent material as binary variables, explaining 38% of the variance in log IC50 (concentration that inhibits 50% of bacterial growth) values for Zn, with 36% for Pb, 44% for Cr, and 68% for Ni. The use of individual equations for each parent material increased the explained variance for all heavy metals, but the presence of a low number of samples (n = 6) lead to low robustness. Generally, clay content and dissolved organic C (DOC) were the main variables explaining bacterial community tolerance for the tested heavy metals. Our results suggest that these equations may permit applying the PICT method with Zn and Pb when there are no reference soils, while more data are needed before using this concept for Ni and Cr.

Pollution-Induced Tolerance of Soil Bacterial Communities to Oxytetracycline-Spiked Manure

The use of manure as a fertilizer is a common agricultural practice that can improve soil physicochemical and biological properties. However, antibiotics and their metabolites are often present, leading to the adaptation of soil bacterial communities to their presence. The aim of this study was to assess the effects of the extensively used, broad-spectrum antibiotic oxytetracycline on soil microbial community adaptation using a pollution-induced community tolerance assay. Manure-amended soil was spiked with oxytetracycline (0, 2, 20, 60, 150, and 500 mg kg−1) three times every ten days in the selection phase. The detection phase was conducted in Biolog EcoPlates with a second oxytetracycline exposure (0, 5, 20, 40, 60, and 100 mg L−1). All treatments demonstrated decreased metabolic activity after exposure to ≥ 5 mg L−1 oxytetracycline during the detection phase. Meanwhile, a significant increase in tolerance was observed following exposure to ≥ 20 mg oxytetracycline per kg soil during the selection phase. Therefore, the pollution-induced community tolerance approach with Biolog EcoPlates was a useful system for the detection of antibiotic selection pressures on soil bacterial communities. It is important to properly manage animal waste before their application to the soil to reduce the occurrence of antibiotic-resistance in the environment.

Religious vilification laws in New Zealand: Should the freedom of expression be taken as gospel?

<p>With ever-increasing multiculturalism and diversity within New Zealand, this paper explores the potential for religious vilification laws to be passed in order to promote community tolerance. New Zealand’s Human Rights Act 1993 includes both civil and criminal offences for the incitement of hostility on the grounds of race. There is no commensurate provision protecting religion. This paper considers the harm that religious vilification laws seek to remedy, and whether their efficacy in preventing this harm is proportionate to the incursion upon the freedom of expression. Ultimately, it suggests that while there are real harms associated with religious hate speech, the adversarial legal system is a flawed instrument through which to deal with it.</p>

Religious vilification laws in New Zealand: Should the freedom of expression be taken as gospel?

<p>With ever-increasing multiculturalism and diversity within New Zealand, this paper explores the potential for religious vilification laws to be passed in order to promote community tolerance. New Zealand’s Human Rights Act 1993 includes both civil and criminal offences for the incitement of hostility on the grounds of race. There is no commensurate provision protecting religion. This paper considers the harm that religious vilification laws seek to remedy, and whether their efficacy in preventing this harm is proportionate to the incursion upon the freedom of expression. Ultimately, it suggests that while there are real harms associated with religious hate speech, the adversarial legal system is a flawed instrument through which to deal with it.</p>

Annoyance due to road traffic noise: an attempt to describe the effects of non-acoustic factors

The annoyance response is traditionally presented as the percentage of people highly annoyed as a function of the noise exposure, DNL, or similar. It is, however, a well-known fact that the noise level per se only explains about one-third of the variance of the annoyance response. An analysis based on the Community Tolerance Level, CTL, quantifies the combined effect of all non-acoustic factors, but does not explain the effect of each individual one. The paper is an attempt to separately quantify the effect of different non-acoustic factors.

Non-responder phenotype reveals apparent microbiome-wide antibiotic tolerance in the murine gut

Broad spectrum antibiotics cause both transient and lasting damage to the ecology of the gut microbiome. Antibiotic-induced loss of gut bacterial diversity has been linked to susceptibility to enteric infections. Prior work on subtherapeutic antibiotic treatment in humans and non-human animals has suggested that entire gut communities may exhibit tolerance phenotypes. In this study, we validate the existence of these community tolerance phenotypes in the murine gut and explore how antibiotic treatment duration or a diet enriched in antimicrobial phytochemicals might influence the frequency of this phenotype. Almost a third of mice exhibited whole-community tolerance to a high dose of the β-lactam antibiotic cefoperazone, independent of antibiotic treatment duration or dietary phytochemical amendment. We observed few compositional differences between non-responder microbiota during antibiotic treatment and the untreated control microbiota. However, gene expression was vastly different between non-responder microbiota and controls during treatment, with non-responder communities showing an upregulation of antimicrobial tolerance genes, like efflux transporters, and a down-regulation of central metabolism. Future work should focus on what specific host- or microbiome-associated factors are responsible for tipping communities between responder and non-responder phenotypes so that we might learn to harness this phenomenon to protect our microbiota from routine antibiotic treatment.