Cytotoxicity of TBBPA and effects on proliferation, cell cycle and MAPK pathways in mammalian cells

Poly-brominated flame retardants are ecotoxicologically relevant chemicals that can show high persistency in environmental samples and bioaccumulation in marine and fresh water animals. One of the most widely used compound is tetrabromobisphenol A (TBBPA). Until today, the toxicological data are rather fragmentary. Our studies on acute and sub-acute toxic effects with established cell lines demonstrate that TBBPA interferes with cellular signaling pathways. Cell viability is significantly reduced in a time- and concentration-dependent manner. The observed EC50 for rat kidney cells (NRK) was 52 microM (27 mg/l), 168 microM (90 mg/l) for A549 human lung cells, and 200 microM (108 mg/l) for Cal-62 human thyroid cells, respectively. The comparison of TBBPA with the non-brominated substance bisphenol A (BPA) clearly demonstrates that only the brominated compound exerts these effects on proliferation and cell viability. Cell cycle regulation was influenced considerably in Cal-62 cells, showing an explicit G2/M arrest in the cell cycle at TBBPA concentrations higher than 75 microM. Cellular signaling pathways directly connected to these affected parameters, e.g. the mitogen activated protein kinase (MAPK) cascades, are partly influenced in a cell specific and dose dependent manner. The extracellular-signal regulated kinase (ERK) is deactivated in NRK and A549 cells and activated in Cal-62 cells with increasing TBBPA concentrations.     

Environmental issues for polymer matrix composites and structural adhesives

The U.S. Department of Defense (DoD) has been utilizing polymer matrix composite (PMC) and structural adhesive materials in military equipment for over 20 years. However, the volume of PMCs in fielded systems has remained relatively low. Currently, however, the DoD has established strategic goals that will necessitate the use of lightweight composites in order to meet performance requirements. Therefore, the volume of composites used in DoD systems is expected to see an unprecedented 100-fold increase over the next 30 years. As production volumes increase, the need to address environmental impact increases. The major contributions to environmental degradation from composites are generation of hazardous air pollutants (HAPs) and generation of hazardous (HW) and solid wastes. HAPs result primarily during the curing of the composite. HWs arise from expiration of stockpiled resin materials and from soiled support media used during manufacturing and clean up. Due to the wide range of applications and materials systems, as well as manufacturing and repair requirements, a family of environmentally benign solutions is needed to reduce and eliminate environmental impacts from PMC manufacturing. Solutions are proposed involving use of new technologies and materials to reduce pollutants from composite manufacturing. The technologies proposed include alternative curing of thermoset composites using electron beam (E-beam) irradiation and materials substitution employing thermoplastics processed using electromagnetic irradiation.     

Levels and determinants of beta(1-->3)-glucans and fungal extracellular polysaccharides in house dust of (pre-)school children in three European countries

BACKGROUND: Mold growth is believed to be one causative factor underlying the association between dampness in buildings and increased respiratory morbidity. Measurements of beta(1-->3)-glucans and fungal extracellular polysaccharides (EPS) are used as markers of mold exposure in field studies. Little is known about their levels and determinants in homes. OBJECTIVE: To study levels and determinants of beta(1-->3)-glucan and EPS levels in mattress and living room floor dust in three European countries. METHODS: Mattress and living room floor dust was collected in the homes of 1065 German, Dutch, and Swedish (pre-)school children. All samples were analyzed for beta(1-->3)-glucans and EPS in one central laboratory. Determinants were assessed by questionnaire. RESULTS: Amounts of dust, EPS and beta(1-->3)-glucan levels differed between countries. Amounts of dust, beta(1-->3)-glucan and EPS levels for mattresses were only weakly correlated with those for living room floors. Floor dust beta(1-->3)-glucan loads, EPS loads and EPS concentrations were strongly correlated with the amount of dust sampled, which is largely determined by the type of floor that was sampled (carpeted floors had 5-20 higher amounts of dust). None of the other determinants was consistently and statistically significantly associated with amounts of dust, beta(1-->3)-glucan and EPS concentrations on floors and mattresses. CONCLUSION: Mattress dust and floor dust are two different measures of exposure to the investigated mold components. Living room floor beta(1-->3)-glucan and EPS loads and EPS concentrations are largely determined by the type of floor sampled. Differences between countries can only partly be explained by the determinants studied.     

Of timelines and timeliness: lessons from Typhoon Haiyan in early disaster response

Typhoon Haiyan struck the Philippines on 8 November 2013 with maximum sustained winds of 235 kilometres per hour, adversely affecting at least 11 million people and displacing some 673,000 in the central regions of the country. The disaster clearly overwhelmed the Philippine government despite its seemingly well‐crafted disaster management plan. Using timelines of different organisations, this paper identifies gaps in the government's response, mainly due to its failure in coordinating and managing relief operations, which adversely affected its effectiveness and efficiency in the delivery of critical goods and services following the disaster. The paper also demonstrates how non‐governmental organisations (NGOs), the United Nations, foreign governments and other organisations provided assistance, mainly through aid niching, to cover the government's shortcomings. The paper recommends a paradigm shift in the government's disaster response by integrating collaborative arrangements between government agencies and NGOs, and giving local governments the lead role, with the national government as support, in disaster planning and response.     

Plants as transmission channels for insect vibrational songs

Summary The vibrational songs of several species of cydnid bugs and small cicadas (leafhoppers and planthoppers) living on various types of plants are recorded by means of laser vibrometry. The recorded vibrational songs are analysed with respect to amplitude, frequency spectrum and structure in the time domain (Figs. 2–5).The emission of vibrational songs from singing insects on plants is simulated. A small magnet is glued to the surface of the plant and moved by means of an electromagnet about one cm away (Fig. 1). The vibrations are recorded by means of laser vibrometry. The propagation velocity of the vibrations increases with the square root of frequency, i.e. in the way expected for bending waves.The mechanical properties of plants ranging from soft bean plants to stiff reeds and maples are measured. The results are used for calculating the theoretical propagation velocities of bending waves. The measured and the calculated values are rather close (Table 1). Although the mechanical properties of the plants studied vary widely, the propagation velocities at a certain frequency are of the same order of magnitude (Table 1).In all the plants studied, only little vibrational energy is lost by friction at frequencies below some kHz. Communication by means of bending waves is possible over distances of some meters. The bending waves are reflected with little loss of energy both from the root and from the top of the plant. The vibration signals may therefore travel up and down the plant several times before decaying completely (Fig. 7). The vibration at a certain spot on the plant depends not only on the distance to and nature of the emitter, but also on the modes of vibration of the plant. The amplitude of vibration does not decrease monotonically with distance from the emitter (Fig. 6).These filtering properties of the plants mean that it is essentially impossible to predict which frequencies in the signals will be amplified or attenuated in the plant at the location of the receiving animal. The vibrational signals recorded from the animals cover wide frequency bandwidths. The signals are therefore well adapted to the filtering properties of the plants, but the signals of the species studied here do not appear to be particularly adapted to specific properties of the host plants.The muscular power needed for communication by means of various types of vibrational signals is calculated. The result of this calculation supports the conclusion that the signals recorded here are carried by means of bending waves.The communication strategies open to small insects are considered. Vibrational signals appear to be an efficient means of communication, but only certain types of signals are suited, because the plants cause a considerable distortion of the signals. One kind of distortion, the dispersive property, may — in theory — be used by the listening animals to obtain information about the direction and distance to the singing animals.Dedicated to Dr. F. ossiannilsson, whose pioneering studies led to the suggestion that small insects may use plants as transmission channels for their songs