16,103 research outputs found
Understanding the Role of Phosphoinositide 3-Kinase and its Function as a Driving Force behind the ER Stress Response in Fibrostenotic Crohnâs Disease-affected Ileal Smooth Muscle Cells
Crohnâs disease (CD) affects about 780,000 people in the United States alone, and it is estimated that 6-15 per 100,000 persons will receive a diagnosis of this disease each year. There currently is no cure for Crohnâs disease, and available medical therapies simply serve to alleviate the inflammation. This does not help treat fibrostenosis that Crohnâs disease patients may develop, which can only be treated surgically. Finding alternatives to treat CD requires an understanding of mechanisms at the biochemical level. In this thesis, we attempted to gain a better understanding of certain pathways found to be active in Crohnâs disease-affected ileal smooth muscle cells. We found an upregulation of the ER stress pathway via expression of its surrogate, the GRP78 protein. We also showed evidence that the phosphoinositide 3-kinase (PI3K) pathway, a key proliferative pathway, is linked to ER stress in these cells, and is an upstream driving force of the ER stress response. Further research on the link between the PI3K and ER stress pathways needs to be conducted, and can potentially serve as a target for therapeutics to help reduce proliferation in fibrostenotic Crohnâs disease-affected ileal smooth muscle cells
On the general governing equations of electromagnetic acoustic transducers
In this paper, we present the general governing equations of electrodynamics
and continuum mechanics that need to be considered while mathematically
modelling the behaviour of electromagnetic acoustic transducers (EMATs). We
consider the existence of finite deformations for soft materials and the
possibility of electric currents, temperature gradients, and internal heat
generation due to dissipation. Starting with Maxwell's equations of
electromagnetism and balance laws of nonlinear elasticity, we present the
governing equations and boundary conditions in incremental form in order to
solve wave propagation problems of boundary value type.Comment: Version 2: Added reference [16] and corrected grammar at a couple of
place
Enhancing Data Security by Making Data Disappear in a P2P Systems
This paper describes the problem of securing data by making it disappear
after some time limit, making it impossible for it to be recovered by an
unauthorized party. This method is in response to the need to keep the data
secured and to protect the privacy of archived data on the servers, Cloud and
Peer-to-Peer architectures. Due to the distributed nature of these
architectures, it is impossible to destroy the data completely. So, we store
the data by applying encryption and then manage the key, which is easier to do
as the key is small and it can be hidden in the DHT (Distributed hash table).
Even if the keys in the DHT and the encrypted data were compromised, the data
would still be secure. This paper describes existing solutions, points to their
limitations and suggests improvements with a new secure architecture. We
evaluated and executed this architecture on the Java platform and proved that
it is more secure than other architectures.Comment: 18 page
Implementing TontineCoin
One of the alternatives to proof-of-work (PoW) consensus protocols is proof-of- stake (PoS) protocols, which address its energy and cost related issues. But they suffer from the nothing-at-stake problem; validators (PoS miners) are bound to lose nothing if they support multiple blockchain forks. Tendermint, a PoS protocol, handles this problem by forcing validators to bond their stake and then seizing a cheaterâs stake when caught signing multiple competing blocks. The seized stake is then evenly distributed amongst the rest of validators. However, as the number of validators increases, the benefit in finding a cheater compared to the cost of monitoring validators reduces, weakening the systemâs defense against the problem. Previous work on TontineCoin addresses this problem by utilizing the concept of tontines. A tontine is an investment scheme in which each participant receives a portion of benefits based on their share. As the number of participants in a tontine decreases, individual benefit increases, which acts as a motivation for participants to eliminate each other. Utilizing this feature in TontineCoin ensures that validators (participants of a tontine) are highly motivated to monitor each other, thus strengthening the system against the nothing-at-stake problem. This project implements a prototype of Tendermint using the Spartan Gold codebase and develops TontineCoin based on it. This implementation is the first implementation of the protocol, and simulates and contrasts five different normal operations in both the Tendermint and TontineCoin models. It also simulates and discusses how a nothing-at-stake attack is handled in TontineCoin compared to Tendermint
Countering Drug Resistance in the Developing World: An Assessment of Incentives across the Value Chain and Recommendations for Policy Interventions
The emergence and spread of drug resistance is draining available resources and threatening our ability to treat infectious diseases in developing countries. HIV/AIDS, tuberculosis, malaria, diarrhea, and respiratory tract infections continue to be the leading causes of death in many developing countries, many of which have already been exacerbated by resistance. Countering drug resistance often involves complex tradeoffs between activities such as the development of new products; ensuring treatment heterogeneity; and guaranteeing quality and ensuring systemic availability, affordability, compliance, adherence and rational use of drugs and diagnostics. A careful understanding of all the players involved in the resistance problem and their incentives to engage in activities that counter drug resistance is crucial for policymakers and resource managers in a range of institutions and agencies. This paper presents results gathered through quasi-structured interviews to understand these incentives and develop recommendations to better align them with resistance-countering activities.drug resistance; developing countries; HIV/AIDS; supply chains; drugs; diagnostics; recommendations; policy
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