258 research outputs found
Normative perspectives on journalism studies: Stock-taking and future directions
Journalism has advanced greatly as a field in its own right in recent decades. As well as a cause for celebration, however, this may give rise to concerns – in particular that scholars may pay increasing attention to the inner workings of journalistic institutions at the expense of their external ties, impact and significance, including their normative ones. It is true that important normative analyses have appeared in the literature, six of which the article defines and exemplifies. So far, however, these ideas have had relatively little influence on the thought or practice of journalists. The article concludes by suggesting a way in which a closer and more constructive dialogue could be achieved between journalism scholars and practitioners, centring on the normative challenges faced by both sides
Impacts of climate change on plant diseases – opinions and trends
There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods
All Is Not Loss: Plant Biodiversity in the Anthropocene
Anthropogenic global changes in biodiversity are generally portrayed in terms of massive native species losses or invasions caused by recent human disturbance. Yet these biodiversity changes and others caused directly by human populations and their use of land tend to co-occur as long-term biodiversity change processes in the Anthropocene. Here we explore contemporary anthropogenic global patterns in vascular plant species richness at regional landscape scales by combining spatially explicit models and estimates for native species loss together with gains in exotics caused by species invasions and the introduction of agricultural domesticates and ornamental exotic plants. The patterns thus derived confirm that while native losses are likely significant across at least half of Earth's ice-free land, model predictions indicate that plant species richness has increased overall in most regional landscapes, mostly because species invasions tend to exceed native losses. While global observing systems and models that integrate anthropogenic species loss, introduction and invasion at regional landscape scales remain at an early stage of development, integrating predictions from existing models within a single assessment confirms their vast global extent and significance while revealing novel patterns and their potential drivers. Effective global stewardship of plant biodiversity in the Anthropocene will require integrated frameworks for observing, modeling and forecasting the different forms of anthropogenic biodiversity change processes at regional landscape scales, towards conserving biodiversity within the novel plant communities created and sustained by human systems
Susceptibility to ozone-induced airway inflammation is associated with decreased levels of surfactant protein D
BACKGROUND: Ozone (O(3)), a common air pollutant, induces exacerbation of asthma and chronic obstructive pulmonary disease. Pulmonary surfactant protein (SP)-D modulates immune and inflammatory responses in the lung. We have shown previously that SP-D plays a protective role in a mouse model of allergic airway inflammation. Here we studied the role and regulation of SP-D in O(3)-induced inflammatory changes in the lung. METHODS: To evaluate the effects of O(3 )exposure in mouse strains with genetically different expression levels of SP-D we exposed Balb/c, C57BL/6 and SP-D knockout mice to O(3 )or air. BAL cellular and cytokine content and SP-D levels were evaluated and compared between the different strains. The kinetics of SP-D production and inflammatory parameters were studied at 0, 2, 6, 12, 24, 48, and 72 hrs after O(3 )exposure. The effect of IL-6, an O(3)-inducible cytokine, on the expression of SP-D was investigated in vitro using a primary alveolar type II cell culture. RESULTS: Ozone-exposed Balb/c mice demonstrated significantly enhanced acute inflammatory changes including recruitment of inflammatory cells and release of KC and IL-12p70 when compared with age- and sex-matched C57BL/6 mice. On the other hand, C57BL/6 mice had significantly higher levels of SP-D and released more IL-10 and IL-6. Increase in SP-D production coincided with the resolution of inflammatory changes. Mice deficient in SP-D had significantly higher numbers of inflammatory cells when compared to controls supporting the notion that SP-D has an anti-inflammatory function in our model of O(3 )exposure. IL-6, which was highly up-regulated in O(3 )exposed mice, was capable of inducing the expression of SP-D in vitro in a dose dependent manner. CONCLUSION: Our data suggest that IL-6 contributes to the up-regulation of SP-D after acute O(3 )exposure and elevation of SP-D in the lung is associated with the resolution of inflammation. Absence or low levels of SP-D predispose to enhanced inflammatory changes following acute oxidative stress
T-cell exhaustion, co-stimulation and clinical outcome in autoimmunity and infection.
The clinical course of autoimmune and infectious disease varies greatly, even between individuals with the same condition. An understanding of the molecular basis for this heterogeneity could lead to significant improvements in both monitoring and treatment. During chronic infection the process of T-cell exhaustion inhibits the immune response, facilitating viral persistence. Here we show that a transcriptional signature reflecting CD8 T-cell exhaustion is associated with poor clearance of chronic viral infection, but conversely predicts better prognosis in multiple autoimmune diseases. The development of CD8 T-cell exhaustion during chronic infection is driven both by persistence of antigen and by a lack of accessory 'help' signals. In autoimmunity, we find that where evidence of CD4 T-cell co-stimulation is pronounced, that of CD8 T-cell exhaustion is reduced. We can reproduce the exhaustion signature by modifying the balance of persistent stimulation of T-cell antigen receptors and specific CD2-induced co-stimulation provided to human CD8 T cells in vitro, suggesting that each process plays a role in dictating outcome in autoimmune disease. The 'non-exhausted' T-cell state driven by CD2-induced co-stimulation is reduced by signals through the exhaustion-associated inhibitory receptor PD-1, suggesting that induction of exhaustion may be a therapeutic strategy in autoimmune and inflammatory disease. Using expression of optimal surrogate markers of co-stimulation/exhaustion signatures in independent data sets, we confirm an association with good clinical outcome or response to therapy in infection (hepatitis C virus) and vaccination (yellow fever, malaria, influenza), but poor outcome in autoimmune and inflammatory disease (type 1 diabetes, anti-neutrophil cytoplasmic antibody-associated vasculitis, systemic lupus erythematosus, idiopathic pulmonary fibrosis and dengue haemorrhagic fever). Thus, T-cell exhaustion plays a central role in determining outcome in autoimmune disease and targeted manipulation of this process could lead to new therapeutic opportunities
The conservation value of human-modified landscapes for the world's primates
Land-use change pushes biodiversity into human-modified landscapes, where native ecosystems are surrounded by anthropic land covers (ALCs). Yet, the ability of species to use these emerging covers remains poorly understood. We quantified the use of ALCs by primates worldwide, and analyzed species' attributes that predict such use. Most species use secondary forests and tree plantations, while only few use human settlements. ALCs are used for foraging by at least 86 species with an important conservation outcome: those that tolerate heavily modified ALCs are 26% more likely to have stable or increasing populations than the global average for all primates. There is no phylogenetic signal in ALCs use. Compared to all primates on Earth, species using ALCs are less often threatened with extinction, but more often diurnal, medium or large-bodied, not strictly arboreal, and habitat generalists. These findings provide valuable quantitative information for improving management practices for primate conservation worldwide
Simultaneous Analysis of Multiple Mycobacterium tuberculosis Knockdown Mutants In Vitro and In Vivo
Mycobacterium tuberculosis (Mtb) represents one of the most persistent bacterial threats to human health and new drugs are needed to limit its impact. Conditional knockdown mutants can help validate new drug targets, but the analysis of individual mutants is laborious and time consuming. Here, we describe quantitative DNA tags (qTags) and their use to simultaneously analyze conditional Mtb knockdown mutants that allowed silencing the glyoxylate and methylcitrate cycles (via depletion of isocitrate lyase, ICL), the serine protease Rv3671c, and the core subunits of the mycobacterial proteasome, PrcB and PrcA. The impact of gene silencing in multi-strain cultures was determined by measuring the relative abundance of mutant-specific qTags with real-time PCR. This achieved accurate quantification over a broad range of qTag abundances and depletion of ICL, Rv3671c, or PrcBA resulted in the expected impairment of growth of Mtb with butyrate as the primary carbon source, survival during oxidative stress, acid stress and starvation. The impact of depleting ICL, Rv3671c, or PrcBA in multi-strain mouse infections was analyzed with two approaches. We first measured the relative abundance of mutant-specific qTags in total chromosomal DNA isolated from bacteria that were recovered from infected lungs on agar plates. We then developed a two-step amplification procedure, which allowed us to measure the abundances of individual mutants directly in infected lung tissue. Both strategies confirmed that inactivation of Rv3671c and PrcBA severely reduced persistence of Mtb in mice. The multi-strain infections furthermore suggested that silencing ICL not only prevented growth of Mtb during acute infections but also prevented survival of Mtb during chronic infections. Analyses of the ICL knockdown mutant in single-strain infections confirmed this and demonstrated that silencing of ICL during chronic infections impaired persistence of Mtb to the extent that the pathogen was cleared from the lungs of most mice
Tau mislocation in glucocorticoid-triggered hippocampal pathology
The exposure to high glucocorticoids (GC) triggers neuronal atrophy and cognitive deficits, but the exact cellular mechanisms underlying the GC-associated dendritic remodeling and spine loss are still poorly understood. Previous studies have implicated sustained GC elevations in neurodegenerative mechanisms through GC-evoked hyperphosphorylation of the cytoskeletal protein Tau while Tau mislocation has recently been proposed as relevant in Alzheimer's disease (AD) pathology. In light of the dual cytoplasmic and synaptic role of Tau, this study monitored the impact of prolonged GC treatment on Tau intracellular localization and its phosphorylation status in different cellular compartments. We demonstrate, both by biochemical and ultrastructural analysis, that GC administration led to cytosolic and dendritic Tau accumulation in rat hippocampus, and triggered Tau hyperphosphorylation in epitopes related to its malfunction (Ser396/404) and cytoskeletal pathology (e.g., Thr231 and Ser262). In addition, we show, for the first time, that chronic GC administration also increased Tau levels in synaptic compartment; however, at the synapse, there was an increase in phosphorylation of Ser396/404, but a decrease of Thr231. These GC-triggered Tau changes were paralleled by reduced levels of synaptic scaffolding proteins such as PSD-95 and Shank proteins as well as reduced dendritic branching and spine loss. These in vivo findings add to our limited knowledge about the underlying mechanisms of GC-evoked synaptic atrophy and neuronal disconnection implicating Tau missorting in mechanism(s) of synaptic damage, beyond AD pathology.We would like to thank Rui Fernandes for TEM technical support. IS was supported by the Portuguese Foundation for Science and Technology (FCT).This work was funded by the Portuguese Foundation for Science and Technology (FCT) (grant NMC-113934 to IS and grant SFRH/BPD/80118/2011 to JC), Canon Foundation and project DoIT - Desenvolvimento e Operacionalização da Investigação de Translação (N° do projeto 13853), funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through the Programa Operacional Fatores de Competitividade (POFC).info:eu-repo/semantics/publishedVersio
Analysis of the population structure of a gorgonian forest (Placogorgia sp.) using a photogrammetric 3D modeling approach at Le Danois Bank, Cantabrian Sea
The presence of gorgonian forests and deep-sea sponge aggregations in the Le Danois Bank promoted its declaration as the “El Cachucho” Marine Protected Area (MPA) by the Spanish Ministry of Environment, and its inclusion in the Natura 2000 network. Both habitats are considered vulnerable, so follow-up surveys are being performed to monitor their conservation in compliance with the EU Habitats Directive. The use of a non-invasive methodology, which does not cause damage or alterations on benthic communities, is particularly necessary in vulnerable ecosystem studies and MPA monitoring.
This study analyzed the assemblage structure of a Placogorgia sp. population using a 3D photogrammetry-based method. The study was carried out through the analysis of the video transects obtained at the Le Danois Bank, using the Politolana underwater towed vehicle during the July 2017 ECOMARG survey. Recent developments in specific software of photogrammetric image analysis allowed extracting valuable information from these video transects. Using the Pix4D Mapper Pro software, 3D point clouds were obtained, and the size and morphometry of yellow fan-shaped gorgonian population structure could be evaluated. Due to gorgonian's high structural complexity, the use of length (i.e. height) as the morphometric descriptor of the real size of the colonies is not appropriate. Instead of length, the fan surface area covered by each gorgonian colony was selected as a suitable parameter of size. The direct measurement of this parameter was possible through a complete 3D reconstruction of the gorgonian forest.
A total of 426 colonies of Placogorgia sp. were digitalized to obtain surface measurements and fan spread orientation calculations in 3D models. The results show that gorgonian populations were mostly composed of a high proportion of small colonies (0–0.10 m2). The population structure distribution shows a high proportion (~27%) of recruits (0.5 m2). In 78% of the gorgonian colonies, facing angles were grouped inside the first quadrant (0°-90°), in accordance with the main current direction in this zone. Colony distribution and fan orientation inside the gorgonian forest can be used as data sources to improve monitoring and management programs of these unique habitats in MPAs
Polychlorinated biphenyls, cytochrome P450 1A1 (CYP1A1) polymorphisms, and breast cancer risk among African American women and white women in North Carolina: a population-based case-control study
INTRODUCTION: Epidemiologic studies have not shown a strong relationship between blood levels of polychlorinated biphenyls (PCBs) and breast cancer risk. However, two recent studies showed a stronger association among postmenopausal white women with the inducible M2 polymorphism in the cytochrome P450 1A1 (CYP1A1) gene. METHODS: In a population-based case-control study, we evaluated breast cancer risk in relation to PCBs and the CYP1A1 polymorphisms M1 (also known as CYP1A1*2A), M2 (CYP1A1*2C), M3 (CYP1A1*3), and M4 (CYP1A1*4). The study population consisted of 612 patients (242 African American, 370 white) and 599 controls (242 African American, 357 white). RESULTS: There was no evidence of strong joint effects between CYP1A1 M1-containing genotypes and total PCBs in African American or white women. Statistically significant multiplicative interactions were observed between CYP1A1 M2-containing genotypes and elevated plasma total PCBs among white women (P value for likelihood ratio test = 0.02). Multiplicative interactions were also observed between CYP1A1 M3-containing genotypes and elevated total PCBs among African American women (P value for likelihood ratio test = 0.10). CONCLUSIONS: Our results confirm previous reports that CYP1A1 M2-containing genotypes modify the association between PCB exposure and risk of breast cancer. We present additional evidence suggesting that CYP1A1 M3-containing genotypes modify the effects of PCB exposure among African American women. Additional studies are warranted, and meta-analyses combining results across studies will be needed to generate more precise estimates of the joint effects of PCBs and CYP1A1 genotypes
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