16 research outputs found
Post-mortem volatiles of vertebrate tissue
Volatile emission during vertebrate decay is a complex process that is understood incompletely. It depends on many factors. The main factor is the metabolism of the microbial species present inside and on the vertebrate. In this review, we combine the results from studies on volatile organic compounds (VOCs) detected during this decay process and those on the biochemical formation of VOCs in order to improve our understanding of the decay process. Micro-organisms are the main producers of VOCs, which are by- or end-products of microbial metabolism. Many microbes are already present inside and on a vertebrate, and these can initiate microbial decay. In addition, micro-organisms from the environment colonize the cadaver. The composition of microbial communities is complex, and communities of different species interact with each other in succession. In comparison to the complexity of the decay process, the resulting volatile pattern does show some consistency. Therefore, the possibility of an existence of a time-dependent core volatile pattern, which could be used for applications in areas such as forensics or food science, is discussed. Possible microbial interactions that might alter the process of decay are highlighted
Vertical profiles in NO3 and N2O5 measured from an aircraft: Results from the NOAA Pâ3 and surface platforms during the New England Air Quality Study 2004
The nocturnal nitrogen oxides, NO3 and N2O5, are important to the chemical transformation and transport of NOx, O3 and VOC. Their concentrations, sources and sinks are known to be vertically stratified in the nighttime atmosphere. In this paper, we report vertical profiles for NO3 and N2O5 measured from an aircraft (the NOAA Pâ3) as part of the New England Air Quality Study in July and August 2004. The aircraft data are compared to surface measurements made in situ from a ship and by longâpath DOAS. Consistent with previous, vertically resolved studies of NO3 and N2O5, the aircraft measurements show that these species occur at larger concentrations and are longer lived aloft than they are at the surface. The array of in situ measurements available on the Pâ3 allows for investigation of the mechanisms that give rise to the observed vertical gradients. Selected vertical profiles from this campaign illustrate the role of biogenic VOC, particularly isoprene and dimethyl sulfide, both within and above the nocturnal and/or marine boundary layer. Gradients in relative humidity and aerosol surface may also create a vertical gradient in the rate of N2O5 hydrolysis. Lowâaltitude intercepts of power plant plumes showed strong vertical stratification, with plume depths of 80 m. The efficiency of N2O5 hydrolysis within these plumes was an important factor determining the lowâlevel NOx and O3 transport or loss at night. Averages of nocturnal O3, NO2, NO3 and N2O5 binned according to altitude were consistent with the trends from individual profiles. While production rates of NO3 peaked near the surface, lifetimes of NO3 and N2O5 were maximum aloft, particularly in the free troposphere. Variability in NO3 and N2O5 was large and exceeded that of NO2 or O3 because of inhomogeneous distribution of NOx emissions and NO3 and N2O5 sinks
Therapeutic control and resistance of the EGFR-driven signaling network in glioblastoma
The alteration of the epidermal growth factor receptor (EGFR)-driven signaling network is a characteristic feature of glioblastomas (GBM), and its inhibition represents a treatment strategy. However, EGFR-targeted interventions have been largely ineffective. Complex perturbations in this system are likely to be central to tumor cells with high adaptive capacity and resistance to therapies. We review key concepts and mechanisms relevant to EGFR-targeted treatment resistance at a systems level. Our understanding of treatment resistance as a systems-level phenomenon is necessary to develop effective therapeutic options for GBM patients. This is allowing us to go beyond the notion of therapeutic targets as single molecular components, into strategies that can weaken cancer signaling robustness and boost inherent network-level vulnerabilities
Beneficial soil microbiome for sustainable agricultural production
The projected increase in world population and the need to reduce the
reliance on non-renewable inputs, such as synthetic agrochemicals, are challenging
the current vision of agriculture. In particular, to achieve a fair and sustainable
global food security, disruptive changes in crop production are unavoidable.
A promising strategy proposes to exploit the metabolic capabilities of soil microbial
communities, i.e., the microbiome, to conjugate stable yield with reduced impact on
the agroecosystem. In this chapter, we introduce the microbiome populating the root-soil interface from an evolutionary perspective. Next, we discuss the molecular
bases of plant-microbe interactions in soil and how these interactions impact plant
growth, development and health. We illustrate how plant-probiotic members of the
microbiome can be isolated from soil and further characterized for their biological
activities, a key pre-requisite for translational applications. In addition, we focus on
paradigmatic examples of soil microbes turned into inoculants for agriculture, their
fate on soil, their impact on the native microbiome and the beneficial effects exerted
on crop productio