The impact of voluntary environmental protection instruments on company environmental performance

In the last decade there has been increasing emphasis on the use of voluntary environmental protection tools such as corporate environmental reporting (CER) and environmental management systems (EMSs). There has been relatively little research, however, on the impact of these tools on the actual environmental performance of companies. This paper presents the findings of a survey of 40 companies operating in Western Australia to determine the extent to which the implementation of two voluntary instruments has influenced company environmental performance. The research considered four questions: To what extent have CER and EMSs influenced the environmental performance of companies operating in Western Australia? What are the characteristics of these influences? How does the influence of EMSs on environmental performance compare to that of CER? Have other external factors concurrently influenced environmental performance? In general, most respondents indicated that EMSs had influenced environmental management practices to some extent. On the other hand, CER was seen more as a public relations exercise and had less impact on company practices compared with EMSs. Other factors that influenced environmental performance included pressure from clients, senior management, the public and regulators; corporate culture; and cost savings

Adhesion and Migration of Monocytes and Dendritic Cells in Type 1 Diabetes

SAMENVATTING VOOR NIET-INGEWIJDEN Type 1 diabetes, vroeger ook wel jeugddiabetes genoemd, wordt gekenmerkt door een afweerreactie gericht tegen de insuline-producerende ß cellen. Bij deze afweerreactie valt het afweersysteem (immuunsysteem) de lichaamseigen ß cellen in de alvleesklier aan en vernietigt deze. Deze afweerreactie waarbij het lichaam zichzelf aanvalt wordt een auto-immuunreactie genoemd. Als gevolg van deze auto-immuunreactie vermindert de productie van insuline, die belangrijk is voor de glucose huishouding binnen het lichaam. Door de verminderde inType 1 diabetes is characterized by a T cell mediated destruction of the insulin-producing ß cells in the islets of Langerhans that are situated in the pancreas. Prior to the infiltration of lymphocytes into the pancreas, an accumulation of macrophages (mf) and dendritic cells (DC) is observed. It is generally thought that these mf and DC originate from blood monocytes that have entered the pancreas and have differentiated into mf or DC. On the basis of their normal physiological role, these cells presumably take up self-antigens and process these into peptides, which they present, after a so-called “steady-state” or “homeostatic” trafficking of the DC to the draining lymph nodes, to T lymphocytes in the para-cortical area. Normally this leads to tolerance induction and T regulatory cells are induced. However in the case of diabetes development, not regulatory T cells, but erroneously effector T lymphocytes become activated and islet autoimmunity is induced. These effector T cells that were primed in the lymph node, become re-activated after re-circulation upon recognition of the self-antigens in the pancreas and consequently – together with macrophages - initiate inflammation and mediate ß cell destruction, which is a hallmark of type 1 diabetes. In this thesis I have studied the processes involved in the early accumulation of mf and DC in the pancreas prior to the infiltration of lymphocytes. The extravasation of monocytes from the circulation into the pancreas is a complex process. Amongst other factors, adhesion molecules, chemokines and myeloid related proteins (MRPs) play an important role in the adhesive and migratory responses of the monocytes that enable effective extravasation. I studied the adhesive and migratory behaviour of human monocytes of type 1 diabetic patients and compared these functions with those of monocytes of type 2 diabetic patients and healthy control subjects. First of all, I was not able to detect any differences between patients and control subjects regarding the subdivision of circulating monocytes in mature and immature cells based on the expression of CD14 and CD16 (chapter 2.1). Secondly, monocytes of patients with type 1 diabetes displayed an intrinsically increased surface expression of the pro-inflammatory molecule MRP8/14 and an increased serum level of MRP8/14. When monocytes were allowed to adhere to the extra cellular matrix component fibronectin the cells showed an enhanced expression and production of MRP8/14. The monocytes of type 1 diabetes patients showed the strongest expression and production of MRP8/14 which was significantly increased over that of healthy control monocytes (chapter 2.2). Furthermore, such activated type 1 diabetic monocytes showed an even stronger adhesion to fibronectin, which was indeed found to be the effect of exposition of the monocytes to MRP8/14 (chapter 2.1). My findings suggest a positive feedback mechanism regarding the adhesive capacity of monocytes in type 1 diabetes: circulating monocytes express and secrete higher levels of MRP8/14 as compared to healthy control subjects, resulting in increased MRP8/14 in the serum. The increased serum MRP8/14 induces an increased adhesive capacity to fibronectin of the monocytes, which leads to an even larger secretion of MRP8/14 compared to healthy controls. In this thesis I also describe that the increased MRP8/14 in the serum induced an increased expression of CD11b/CD18 on the monocytes that is likely involved in the increased adhesion of the type 1 diabetic monocytes to endothelial cells that I observed (chapter 2.2). After the adhesion studies I investigated the migratory behaviour of monocytes of type 1 diabetes patients and observed a remarkably decreased response towards the pro-inflammatory chemokines CCL2 and CCL3. Both the transendothelial migration (measured in a Transwell system) and the chemotaxis (measured in the classical Boyden assay) towards these pro-inflammatory chem

Micro-simulation as a tool to assess policy concerning non-point source pollution: the case of ammonia in Dutch agriculture

Non-point source pollution is notoriously difficult to asses. A relevant example is ammonia emissions in the Netherlands. Since the mid 1980s the Dutch government has sought to reduce emissions through a wide variety of measures, the effect of which in turn is monitored using modeling techniques. This paper presents the current generation of mineral emission models from agriculture based on micro-simulation of farms in combination with a spatial equilibrium model for the dispersion of manure from excess regions with high livestock intensities within the country to areas with low livestock intensitie

Field trial for assessment of avian influenza vaccination effectiveness in Indonesia

The aim of this field study was to determine the efficacy of vaccination against highly pathogenic avian influenza (HPAI) virus strain H5N1 in Indonesia. A limited, prototype clinical trial was performed using a standardised treatment group, in which poultry flocks were vaccinated at least twice with a selected H5N1 vaccine, and a control group comprising flocks treated with nonstandardised procedures chosen by the farmer. Each group consisted of six flocks comprising either layers or native chickens. Haemagglutination inhibition (HI) antibody levels were determined by regular serum sampling, and outbreak surveillance relied on non-Al-vaccinated sentinel birds. After three vaccinations high antibody titres were produced in the treatment group, and the percentage of layers with an HI titre > 40 was approximately 90%. Although no conclusions can be drawn regarding reduction of virus transmission, this study demonstrated that 11 farms remained free from Al during the observation period, and that a surveillance programme based on differentiating infected from vaccinated animals (DIVA) can be implemented