12,109 research outputs found
The telomerase essential N-terminal domain promotes DNA synthesis by stabilizing short RNA-DNA hybrids.
Telomerase is an enzyme that adds repetitive DNA sequences to the ends of chromosomes and consists of two main subunits: the telomerase reverse transcriptase (TERT) protein and an associated telomerase RNA (TER). The telomerase essential N-terminal (TEN) domain is a conserved region of TERT proposed to mediate DNA substrate interactions. Here, we have employed single molecule telomerase binding assays to investigate the function of the TEN domain. Our results reveal telomeric DNA substrates bound to telomerase exhibit a dynamic equilibrium between two states: a docked conformation and an alternative conformation. The relative stabilities of the docked and alternative states correlate with the number of basepairs that can be formed between the DNA substrate and the RNA template, with more basepairing favoring the docked state. The docked state is further buttressed by the TEN domain and mutations within the TEN domain substantially alter the DNA substrate structural equilibrium. We propose a model in which the TEN domain stabilizes short RNA-DNA duplexes in the active site of the enzyme, promoting the docked state to augment telomerase processivity
Migration and global environmental change. DR8a: quantifying change in ecosystem services and exposure to hazards in the Mediterranean basin over the next 50 years that might be relevant to migration
A New Phenomenon: Sub-Tg, Solid-State, Plasticity-Induced Bonding in Polymers
Polymer self-adhesion due to the interdiffusion of macromolecules has been an
active area of research for several decades [70, 43, 62, 42, 72, 73, 41]. Here,
we report a new phenomenon of sub-Tg, solid-state, plasticity-induced bonding;
where amorphous polymeric films were bonded together in a period of time on the
order of a second in the solid-state at ambient temperatures nearly 60 K below
their glass transition temperature (Tg) by subjecting them to active plastic
deformation. Despite the glassy regime, the bulk plastic deformation triggered
the requisite molecular mobility of the polymer chains, causing
interpenetration across the interfaces held in contact. Quantitative levels of
adhesion and the morphologies of the fractured interfaces validated the sub-Tg,
plasticity-induced, molecular mobilization causing bonding. No-bonding outcomes
(i) during the compression of films in a near hydrostatic setting (which
inhibited plastic flow) and (ii) between an 'elastic' and a 'plastic' film
further established the explicit role of plastic deformation in this newly
reported sub-Tg solid-state bonding
The Effects of the Food Stamp Program on Energy Balance and Obesity
The Effects of the Food Stamp Program on Energy Balance and ObesityFood Stamp Program (FSP), Supplemental Nutrition Assistance Program (SNAP), obesity, body mass index (BMI), nutrition assistance, Food Consumption/Nutrition/Food Safety, Q18, H53, I12, I18, I38,
Avionics test bed development plan
The plan is for a facility for the early investigation and evaluation of new concepts for the control of large space structures, orbiter attached flex body experiments, and orbiter enhancements. This plan outlines a distributed data processing facility that will utilize the current JSC laboratory resources for the test bed development. The future studies required for implementation, the management system for project control, and the baseline system configuration are described
The governance of wolves in transboundary regions: a triquetrous study of ephemeral agreements transcending sub-national and national boundaries
Thesis (M.S.) University of Alaska Fairbanks, 2013Contradictory management objectives in adjacent jurisdictions can affect transboundary wolves and their associated socio-ecological systems. Elite interviews and case study methodology were used in this thesis to explore three transboundary wolf management agreements, their effectiveness, and their impacts on wolves, ecosystems and stakeholders. Separate agreements between the State of Alaska and: Yukon-Charley Rivers National Preserve, and Denali National Park and Preserve, and an agreement between Italy and Switzerland show that despite a diversity of socio-ecological contexts, approaches, and hierarchical level of actors, transboundary wolf agreements are prone to ephemerality. The ephemerality of these agreements appears to be due primarily to institutional path dependency, and to political tension between management entities. The impacts of these agreements and their cessation, on socio-ecological systems are limited by the agreements' limited scopes. The agreements do however figure incrementally into larger trends, especially including changes in rural and urban identities, and in large carnivore management discourse. I argue that a diversity of wolf management approaches across a landscape, and the inherent conflict between management entities preserves adaptive capacity by preventing one size fits all prescriptions based on incomplete knowledge. Assuming no acute state of emergency, incremental rather than transformational change is more equitable to diverse stakeholders; allowing public perception, policy, and scientific knowledge to shift concurrently. The cases also suggest that facilitating trans-entity conversation and coordination at multiple levels would support understanding, and increase the prevalence of creative agreements contributing to amenable, incremental change. Landscape Conservation Cooperatives are put forth as a potential platform or template for this facilitation
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