67 research outputs found
Carrion Availability in Space and Time
Introduction
Availability of carrion to scavengers is a central issue in carrion ecology and management, and is crucial for understanding the evolution of scavenging behaviour. Compared to live animals, their carcasses are relatively unpredictable in space and time in natural conditions, with a few exceptions (see below, especially Sect. âCarrion Exchange at the Terrestrial-Aquatic Interfaceâ). Carrion is also an ephemeral food resource due to the action of a plethora of consumers, from microorganisms to large vertebrates, as well as to desiccation (i.e., loss of water content; DeVault et al. 2003; Beasley et al. 2012; Barton et al. 2013; MoleĂłn et al. 2014). With a focus on vertebrate carcasses, here we give an overview of (a) the causes that produce carrion, (b) the rate of carrion production, (c) the factors affecting carrion quality, and (d) the distribution of carrion in space and time, both in terrestrial and aquatic environments (including their interface). In this chapter, we will focus on naturally produced carrion, whereas non-natural causes of animal mortality are described in chapter âHuman-Mediated Carrion: Effects on Ecological Processesâ. However, throughout this chapter we also refer to extensive livestock carrion, because in the absence of strong restrictions such as those imposed in the European Community after the bovine spongiform encephalopathy crisis (DonĂĄzar et al. 2009; Margalida et al. 2010), the spatiotemporal availability of carrion of extensive livestock and wild ungulates is similar
Epithelial-immune cell interplay in primary Sjogren syndrome salivary gland pathogenesis
In primary Sjogren syndrome (pSS), the function of the salivary glands is often considerably reduced. Multiple innate immune pathways are likely dysregulated in the salivary gland epithelium in pSS, including the nuclear factor-kappa B pathway, the inflammasome and interferon signalling. The ductal cells of the salivary gland in pSS are characteristically surrounded by a CD4(+) T cell-rich and B cell-rich infiltrate, implying a degree of communication between epithelial cells and immune cells. B cell infiltrates within the ducts can initiate the development of lymphoepithelial lesions, including basal ductal cell hyperplasia. Vice versa, the epithelium provides chronic activation signals to the glandular B cell fraction. This continuous stimulation might ultimately drive the development of mucosa-associated lymphoid tissue lymphoma. This Review discusses changes in the cells of the salivary gland epithelium in pSS (including acinar, ductal and progenitor cells), and the proposed interplay of these cells with environmental stimuli and the immune system. Current therapeutic options are insufficient to address both lymphocytic infiltration and salivary gland dysfunction. Successful rescue of salivary gland function in pSS will probably demand a multimodal therapeutic approach and an appreciation of the complicity of the salivary gland epithelium in the development of pSS. Salivary gland dysfunction is an important characteristic of primary Sjogren syndrome (pSS). In this Review, the authors discuss various epithelial abnormalities in pSS and the mechanisms by which epithelial cell-immune cell interactions contribute to disease development and progression
Pan-cancer analysis of whole genomes
Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe
The ERK and JNK pathways in the regulation of metabolic reprogramming.
Most tumor cells reprogram their glucose metabolism as a result of mutations in oncogenes and tumor suppressors, leading to the constitutive activation of signaling pathways involved in cell growth. This metabolic reprogramming, known as aerobic glycolysis or the Warburg effect, allows tumor cells to sustain their fast proliferation and evade apoptosis. Interfering with oncogenic signaling pathways that regulate the Warburg effect in cancer cells has therefore become an attractive anticancer strategy. However, evidence for the occurrence of the Warburg effect in physiological processes has also been documented. As such, close consideration of which signaling pathways are beneficial targets and the effect of their inhibition on physiological processes are essential. The MAPK/ERK and MAPK/JNK pathways, crucial for normal cellular responses to extracellular stimuli, have recently emerged as key regulators of the Warburg effect during tumorigenesis and normal cellular functions. In this review, we summarize our current understanding of the roles of the ERK and JNK pathways in controlling the Warburg effect in cancer and discuss their implication in controlling this metabolic reprogramming in physiological processes and opportunities for targeting their downstream effectors for therapeutic purposes.Brunel Research Initiative & Enterprise Fund, Brunel University
of London (to CB), Kay Kendall Leukemia Fund (KKL443) (to CB),
250 Great Minds Fellowship, University of Leeds (to SP), AMMF
Cholangiocarcinoma Charity (to SP and PMC), and Bloodwise
(17014) (to SP and CB)
Enhancing the production of light olefins from heavy crude oils: Turning challenges into opportunities
The large reserves of heavy crude oils and the significant demand of light olefins, particularly propylene, have created new opportunities for developing advanced catalyst and process technologies that efficiently upgrade asphaltenes-enriched crudes to high values chemicals. Indeed, many petrochemicals are produced during crude oil refining as side streams, because the primary goal of the crude oil refinery is the production of transportation fuel. This paper attempts to briefly review the properties of heavy crude oils, the major process technologies for the production of light olefins such as steam cracking and fluid catalytic cracking and finally the catalyst technology mainly focused on ZSM-5 and HY zeolites. We include not only the current understanding of the olefin production technologies, but also the challenges involved in the upgrading of unconventional crudes and residue with high content of heteroatoms and unsaturated poly-aggregate asphaltenes. A strategy for processing unconventional oil that involves the utilization of steam (catalytic) cracking process, in a FCC-type configuration, and enhanced cracking catalyst with high hydrothermal stability is also analyzed
Enhancing the production of light olefins from heavy crude oils: Turning challenges into opportunities
The large reserves of heavy crude oils and the significant demand of light olefins, particularly propylene, have created new opportunities for developing advanced catalyst and process technologies that efficiently upgrade asphaltenes-enriched crudes to high values chemicals. Indeed, many petrochemicals are produced during crude oil refining as side streams, because the primary goal of the crude oil refinery is the production of transportation fuel. This paper attempts to briefly review the properties of heavy crude oils, the major process technologies for the production of light olefins such as steam cracking and fluid catalytic cracking and finally the catalyst technology mainly focused on ZSM-5 and HY zeolites. We include not only the current understanding of the olefin production technologies, but also the challenges involved in the upgrading of unconventional crudes and residue with high content of heteroatoms and unsaturated poly-aggregate asphaltenes. A strategy for processing unconventional oil that involves the utilization of steam (catalytic) cracking process, in a FCC-type configuration, and enhanced cracking catalyst with high hydrothermal stability is also analyzed
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