Fortuna Field Station

Apoptosis of inflammatory cells and their subsequent clearance (efferocytosis) by macrophages (Mphis) are key mechanisms orchestrating successful resolution of inflammation. Although the powerful proinflammatory agents lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNF-alpha) influence rates of inflammatory cell apoptosis, little is known about their effects on efferocytosis. We have demonstrated that LPS and TNF-alpha potently inhibit efferocytosis of neutrophils by monocyte-derived Mphis. Inhibition was both concentration and time dependent, although the effect of TNF-alpha was more rapid. We have found that soluble TNF receptor-I attenuated LPS inhibition of phagocytosis, indicating that TNF-alpha production is critical. Inhibition of efferocytosis by LPS was found to be positively associated with Mphi production of TNF-alpha, but negatively with interleukin-10 (IL-10) release. A critical role for IL-10 in the regulation of phagocytosis was suggested by 2 important findings: LPS inhibition was observed more rapidly in the presence of an anti-human IL-10 receptor-alpha antibody, and efferocytosis by IL-10-deficient Mphis was markedly reduced compared to wild-type Mphis. Furthermore, exogenous IL-10 and glucocorticoids reversed inhibitory effects of LPS on efferocytosis via suppression of TNF-alpha production. We suggest that efferocytosis is regulated in an autocrine manner by pro- and anti-inflammatory mediators, and the inflammatory milieu determines whether inflammation successfully resolves.

The construction sector is regarded as one of the fundamental causes of environmental pollution globally due to noise, water, air pollution from harmful gases, dust, solid and liquid waste. Furthermore, due to heavy machinery operations, oil spills occur frequently. Therefore, an environmental management plan was introduced as a document prepared during the environmental management process to guide the environmental impact mitigation through the entire construction project life cycle, from project initiation to decommissioning as a legal requirement for all contractors to comply. However, despite compliance in the form of an environmental management plan being a legal requirement for construction projects in South Africa, environmental management plans are not prevalent, pervasive, enforced on construction sites. Therefore, the study examines the prevalence and effectiveness of environmental management plans as legal requirements on construction projects in eThekwini Municipality of KwaZulu-Natal. A quantitative study was employed, and data were analyzed using IBM Statistical Package for Social Sciences (SPSS) version 27. Descriptive statistics was adopted for the data analysis. The technique used to collect data was convenience sampling based on proximity and familiarity and completed in close-ended questionnaires through google forms and completed questionnaires copies, 91 population participated in the study from different contractors. Cronbach’s Alpha reliability test was used to determine the internal consistency of the constructs used to examine the prevalence and effectiveness of environmental management plans as legal requirements. Internal consistency of various scales was deemed acceptable for interpretation. The results revealed that contractors do not provide enough training and induction about environment management plans to staff and construction workers before the project starts. Therefore, this causes contractors to not fully comply with an environmental management plan because site managers and construction workers are not making a better-informed decision on protecting the environment when they are physically involved in the execution of activities onsite. The results further suggested that contractors see environmental management plans as a waste of time; they prefer to focus on production and profit maximization. Therefore, this has led to contractors not complying with construction projects' environmental management plans. The results also suggested that few contractors have environmental management plans on their daily site Instruction; not all contractors consider environmental management plans on their daily site instructions. The absence of environmental management plan on daily site instructions of contractors on-site is one of the factors causing contractors to continue harming and degrading the environment because site management and construction workers are not daily reminded about the environmental hazards on-site during the execution of activities. Therefore, contractors need to start considering environmental management plans on their daily site instruction to remind their employees about expected and potential hazards because they are physically involved with execution on site. Therefore, it will benefit the effectiveness of environmental environment plans on construction projects.