21 research outputs found

    The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing.

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    Microbial ecology is plagued by problems of an abstract nature. Cell sizes are so small and population sizes so large that both are virtually incomprehensible. Niches are so far from our everyday experience as to make their very definition elusive. Organisms that may be abundant and critical to our survival are little understood, seldom described and/or cultured, and sometimes yet to be even seen. One way to confront these problems is to use data of an even more abstract nature: molecular sequence data. Massive environmental nucleic acid sequencing, such as metagenomics or metatranscriptomics, promises functional analysis of microbial communities as a whole, without prior knowledge of which organisms are in the environment or exactly how they are interacting. But sequence-based ecological studies nearly always use a comparative approach, and that requires relevant reference sequences, which are an extremely limited resource when it comes to microbial eukaryotes. In practice, this means sequence databases need to be populated with enormous quantities of data for which we have some certainties about the source. Most important is the taxonomic identity of the organism from which a sequence is derived and as much functional identification of the encoded proteins as possible. In an ideal world, such information would be available as a large set of complete, well curated, and annotated genomes for all the major organisms from the environment in question. Reality substantially diverges from this ideal, but at least for bacterial molecular ecology, there is a database consisting of thousands of complete genomes from a wide range of taxa, supplemented by a phylogeny-driven approach to diversifying genomics [2]. For eukaryotes, the number of available genomes is far, far fewer, and we have relied much more heavily on random growth of sequence databases, raising the question as to whether this is fit for purpose

    Genome Evolution of Asexual Organisms and the Paradox of Sex in Eukaryotes

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    Leadership and Collaborative Governance in Managing Emergencies and Crises

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    Leadership and governance are two concepts very central to disaster management. This chapter analyzes disaster and crisis management in two mega-disasters of 2010: the Haiti Earthquake and Pakistan Floods. These two cases are compared and contrasted from collaborative governance, international coordination, and multi-layered leadership perspectives. Findings indicate that leadership is a multi-layered and multi-dimensional phenomenon and concept in disasters and collaborative settings. Leadership layers comprise presidential and political leadership, civilian government leadership, military leadership, international humanitarian leadership which is primarily UN centric, and also community leadership. Comparative governance and leadership structures in the two countries show that the Pakistan military response and their leadership stand out because of their commendable efforts in the flood response and relief phases. On the other hand, Haiti has no military forces and had to rely heavily on the US military. Overall political leadership seems to be very weak in the two countries. The issue of competitive elections in Haiti, the deaths of many government officials and the destruction of government offices in the capital city contributed to worsening Haiti’s government response. Findings also indicate that the International humanitarian leadership which is UN centric, and follows a UN cluster approach, has ample shortcomings and needs to be revamped and improved

    Gain-of-function variant in GLUD2 glutamate dehydrogenase modifies Parkinson's disease onset

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    Parkinson's disease (PD), a common neurodegenerative disorder characterized by progressive loss of dopaminergic neurons and their terminations in the basal ganglia, is thought to be related to genetic and environmental factors. Although the pathophysiology of PD neurodegeneration remains unclear, protein misfolding, mitochondrial abnormalities, glutamate dysfunction and/or oxidative stress have been implicated. In this study, we report that a rare T1492G variant in GLUD2, an X-linked gene encoding a glutamate dehydrogenase (a mitochondrial enzyme central to glutamate metabolism) that is expressed in brain (hGDH2), interacted significantly with age at PD onset in Caucasian populations. Individuals hemizygous for this GLUD2 coding change that results in substitution of Ala for Ser445 in the regulatory domain of hGDH2 developed PD 6–13 years earlier than did subjects with other genotypes in two independent Greek PD groups and one North American PD cohort. However, this effect was not present in female PD patients who were heterozygous for the DNA change. The variant enzyme, obtained by substitution of Ala for Ser445, showed an enhanced basal activity that was resistant to GTP inhibition but markedly sensitive to modification by estrogens. Thus, a gain-of-function rare polymorphism in hGDH2 hastens the onset of PD in hemizygous subjects, probably by damaging nigral cells through enhanced glutamate oxidative dehydrogenation. The lack of effect in female heterozygous PD patients could be related to a modification of the overactive variant enzyme by estrogens
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