Thermobia domestica belongs to an ancient group of insects and has a remarkable ability to digest crystalline cellulose without microbial assistance. By investigating the digestive proteome of ...Thermobia, we have identified over 20 members of an uncharacterized family of lytic polysaccharide monooxygenases (LPMOs). We show that this LPMO family spans across several clades of the Tree of Life, is of ancient origin, and was recruited by early arthropods with possible roles in remodeling endogenous chitin scaffolds during development and metamorphosis. Based on our in-depth characterization of Thermobia's LPMOs, we propose that diversification of these enzymes toward cellulose digestion might have endowed ancestral insects with an effective biochemical apparatus for biomass degradation, allowing the early colonization of land during the Paleozoic Era. The vital role of LPMOs in modern agricultural pests and disease vectors offers new opportunities to help tackle global challenges in food security and the control of infectious diseases.
Potato pectin falls to
Phytophthora
Phytophthora infestans
is a plant oomycete pathogen that drove the potato famines of the 1800s and continues to afflict potato fields today. The polysaccharide ...pectin makes up about a third of the cell wall in potatoes. Sabbadin
et al
. identified a family of lytic polysaccharide monooxygenases (LMPOs) that cleave pectin and are upregulated in
P. infestans
during infection. Silencing the relevant LMPO gene successfully inhibited
P. infestans
infections. These findings open doors for disease intervention targets and for biotech applications. —PJH
Virulence factors secreted by the plant pathogen
Phytophthora infestans
target pectin polysaccharides in plant cell walls.
The oomycete
Phytophthora infestans
is a damaging crop pathogen and a model organism to study plant-pathogen interactions. We report the discovery of a family of copper-dependent lytic polysaccharide monooxygenases (LPMOs) in plant pathogenic oomycetes and its role in plant infection by
P. infestans
. We show that LPMO-encoding genes are up-regulated early during infection and that the secreted enzymes oxidatively cleave the backbone of pectin, a charged polysaccharide in the plant cell wall. The crystal structure of the most abundant of these LPMOs sheds light on its ability to recognize and degrade pectin, and silencing the encoding gene in
P. infestans
inhibits infection of potato, indicating a role in host penetration. The identification of LPMOs as virulence factors in pathogenic oomycetes opens up opportunities in crop protection and food security.
•Biological lignocellulose deconstruction mechanisms are diverse.•They are widely but sparsely dispersed across the Tree of Life.•Some mechanisms operate at physico-chemical extremes of the ...biosphere.•Diversity informs biotechnology for biofuels generation.
Organisms use diverse mechanisms involving multiple complementary enzymes, particularly glycoside hydrolases (GHs), to deconstruct lignocellulose. Lytic polysaccharide monooxygenases (LPMOs) produced by bacteria and fungi facilitate deconstruction as does the Fenton chemistry of brown-rot fungi. Lignin depolymerisation is achieved by white-rot fungi and certain bacteria, using peroxidases and laccases. Meta-omics is now revealing the complexity of prokaryotic degradative activity in lignocellulose-rich environments. Protists from termite guts and some oomycetes produce multiple lignocellulolytic enzymes. Lignocellulose-consuming animals secrete some GHs, but most harbour a diverse enzyme-secreting gut microflora in a mutualism that is particularly complex in termites. Shipworms however, house GH-secreting and LPMO-secreting bacteria separate from the site of digestion and the isopod Limnoria relies on endogenous enzymes alone. The omics revolution is identifying many novel enzymes and paradigms for biomass deconstruction, but more emphasis on function is required, particularly for enzyme cocktails, in which LPMOs may play an important role.
Apprenticeship, the process of developing from novice to proficiency under the guidance of a skilled expert, varies across cultures and among different skilled communities, but for many communities ...of practice, apprenticeship offers an ideal ethnographic point of entry. For certain kinds of anthropological fieldwork, such as studies of bodily arts, apprenticeship may offer an essential research method. In this article, three anthropologists discuss their experiences using apprenticeship in fieldwork and consider the practical and theoretical issues of apprenticeship as a site of ethnographic inquiry. As a channel for achieving social inclusion, apprenticeship offers anthropologists opportunities to navigate and chart interpersonal power, access to emic types of knowledge, first-hand experience of the pedagogical milieu, and avenues to acquire cultural proficiency. Because apprenticeship itself includes mechanisms to socialize emerging skill, such as disciplining the generation of variation that is inherent in each individual’s rediscovery or reinvention of skill, apprenticeship encourages our subjects to collaborate with us by allowing them to critique the ethnographer’s performance and provide feedback in familiar, locally-meaningful ways.
A systems approach to animal communication Hebets, Eileen A.; Barron, Andrew B.; Balakrishnan, Christopher N. ...
Proceedings of the Royal Society. B, Biological sciences,
03/2016, Letnik:
283, Številka:
1826
Journal Article
Recenzirano
Odprti dostop
Why animal communication displays are so complex and how they have evolved are active foci of research with a long and rich history. Progress towards an evolutionary analysis of signal complexity, ...however, has been constrained by a lack of hypotheses to explain similarities and/or differences in signalling systems across taxa. To address this, we advocate incorporating a systems approach into studies of animal communication—an approach that includes comprehensive experimental designs and data collection in combination with the implementation of systems concepts and tools. A systems approach evaluates overall display architecture, including how components interact to alter function, and how function varies in different states of the system. We provide a brief overview of the current state of the field, including a focus on select studies that highlight the dynamic nature of animal signalling. We then introduce core concepts from systems biology (redundancy, degeneracy, pluripotentiality, and modularity) and discuss their relationships with system properties (e.g. robustness, flexibility, evolvability). We translate systems concepts into an animal communication framework and accentuate their utility through a case study. Finally, we demonstrate how consideration of the system-level organization of animal communication poses new practical research questions that will aid our understanding of how and why animal displays are so complex.
Tuberculosis transmission continues to be a major public health challenge. In this cluster-randomized, controlled trial conducted in Vietnam, active community-wide screening for tuberculosis over 4 ...years is shown to decrease the prevalence of tuberculosis.
Mozambique is one of the countries with the deadly implementation gaps in the tuberculosis (TB) care and services delivery. In-hospital delays in TB diagnosis and treatment, transmission and ...mortality still persist, in part, due to poor-quality of TB care cascade.
We aimed to assess, from the healthcare workers' (HCW) perspective, factors associated with poor-quality TB care cascade and explore local sustainable suggestions to improve in-hospital TB management.
In-depth interviews and focus group discussions were conducted with different categories of HCW. Audio-recording and written notes were taken, and content analysis was performed through atlas.ti7.
Bottlenecks within hospital TB care cascade, lack of TB staff and task shifting, centralized and limited time of TB laboratory services, and fear of healthcare workers getting infected by TB were mentioned to be the main factors associated with implementation gaps. Interviewees believe that task shifting from nurses to hospital auxiliary workers, and from higher and well-trained to lower HCW are accepted and feasible. The expansion and use of molecular TB diagnostic tools are seen by the interviewees as a proper way to fight effectively against both sensitive and MDR TB. Ensuring provision of N95 respiratory masks is believed to be an essential requirement for effective engagement of the HCW on high-quality in-hospital TB care. For monitoring and evaluation, TB quality improvement teams in each health facility are considered to be an added value.
Shortage of resources within the national TB control programme is one of the potential factors for poor-quality of the TB care cascade. Task shifting of TB care and services delivery, decentralization of the molecular TB diagnostic tools, and regular provision of N95 respiratory masks should contribute not just to reduce the impact of resource scarceness, but also to ensure proper TB diagnosis and treatment to both sensitive and MDR TB.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Global in Global Health is Not a Given Mason, Paul H; Kerridge, Ian; Lipworth, Wendy
The American journal of tropical medicine and hygiene
96, Številka:
4
Journal Article
Recenzirano
Odprti dostop
AbstractThe process of globalization is commonly espoused as a means for promoting global health. Efforts to "go global" can, however, easily go awry as a result of lack of attention to local social, ...economic, and political contexts and/or as a result of commercial and political imperatives that allow local populations to be exploited. Critical analysis of the processes of globalization is necessary to better understand the local particularities of global projects and confront challenges more transparently. We illustrate the potential adverse impacts of globalization in the global health setting, through examination of international tuberculosis control, global mental health, and the establishment of transnational biobank networks.
Tuberculosis (TB) researchers and clinicians, by virtue of the social disease they study, are drawn into an engagement with ways of understanding illness that extend beyond the strictly biomedical ...model. Primers on social science concepts directly relevant to TB, however, are lacking. The particularities of TB disease mean that certain social science concepts are more relevant than others. Concepts such as structural violence can seem complicated and off-putting. Other concepts, such as gender, can seem so familiar that they are left relatively unexplored. An intimate familiarity with the social dimensions of disease is valuable, particularly for infectious diseases, because the social model is an important complement to the biomedical model. This review article offers an important introduction to a selection of concepts directly relevant to TB from health sociology, medical anthropology and social cognitive theory. The article has pedagogical utility and also serves as a useful refresher for those researchers already engaged in this genre of work. The conceptual tools of health sociology, medical anthropology and social cognitive theory offer insightful ways to examine the social, historical and cultural dimensions of public health. By recognizing cultural experience as a central force shaping human interactions with the world, TB researchers and clinicians develop a more nuanced consideration of how health, illness and medical treatment are understood, interpreted and confronted.
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