Cause of Chirality Consensus

Biological macromolecules, proteins and nucleic acids are composed exclusively of chirally pure monomers. The chirality consensus appears vital for life and it has even been considered as a prerequisite of life. However the primary cause for the ubiquitous handedness has remained obscure. We propose that the chirality consensus is a kinetic consequence that follows from the principle of increasing entropy, i.e. the 2nd law of thermodynamics. Entropy increases when an open system evolves by decreasing gradients in free energy with more and more efficient mechanisms of energy transduction. The rate of entropy increase is the universal fitness criterion of natural selection that favors diverse functional molecules and drives the system to the chirality consensus to attain and maintain high-entropy non-equilibrium states.Comment: 8 pages, 2 figure

Study on the Effect of Mno2 as Sintering Additive in Structural, Magnetic and Electrical Properties of Solid-State Derived Ni0.8Zn0.2Fe2O4

Ni-Zn ferrites have been synthesized with varying MnO2 as sintering aid as well as enhancer in magnetic property. The influence of MnO2 additive on the properties of Ni-Zn ferrites was studied by the conventional ceramic method (solid oxide mixing followed by calcination). The results showed that MnO2 does not form a visible second phase while the added concentration was restricted to 0−0.6 weight%. The average grain size, sintering density and gradually decrease with the increase of the MnO2 content. And the DC resistivity continuously increases with the increase of MnO2 content. The saturation magnetization (magnetic moment in unit mass) first increases slightly when mass fraction of MnO2 is less than 0.4% MnO2, and then gradually decreases with increasing the MnO2 mass fraction due to the exchange interaction of the cations. When the excitation frequency is less than 1 MHz, the power loss (Pcv) continuously increases with increasing the MnO2 content due to the decrease of average grain size. However, when the excitation frequency exceeds 1 MHz, eddy current loss gradually becomes the predominant contribution to Pcv. The present investigations reports the effect of additive MnO2 in varying amount i.e. 0.0%, 0.2%, 0.4% and 0.6% on the structural, magnetic and electric properties of NI0.8ZN0.2Fe2O4 prepared by solid oxide mixing method. The powders were calcined at 950ᵒC for 4hrs, XRD analysis conducted. After the confirmation of phases, powders were pressed into pellet. The pellet of different composition were sintered at different temperature and characterized for apparent porosity, bulk density and B-H loop using Magneta. For the phase formation, the pellets were characterized by using XRD and for the microstructure analysis, the pellets were characterized by using FESEM. DC resistivity, magnetic properties are affected by addition of MnO

On the Performance of Multiple Antenna Cooperative Spectrum Sharing Protocol under Nakagami-m Fading

In a cooperative spectrum sharing (CSS) protocol, two wireless systems operate over the same frequency band albeit with different priorities. The secondary (or cognitive) system which has a lower priority, helps the higher priority primary system to achieve its target rate by acting as a relay and allocating a fraction of its power to forward the primary signal. The secondary system in return is benefited by transmitting its own data on primary system's spectrum. In this paper, we have analyzed the performance of multiple antenna cooperative spectrum sharing protocol under Nakagami-m Fading. Closed form expressions for outage probability have been obtained by varying the parameters m and Omega of the Nakagami-m fading channels. Apart from above, we have shown the impact of power allocation factor (alpha) and parameter m on the region of secondary spectrum access, conventionally defined as critical radius for the secondary system. A comparison between theoretical and simulated results is also presented to corroborate the theoretical results obtained in this paperComment: Accepted in the proceedings of IEEE PIMRC 2015 Hong Kong, Chin

Better Result in Packet Loss and Saving Energy in Ad-Hoc Network by using Improved MAC Protocol

An Ad-Hoc network is a wireless, decentralized, dynamic network in which devices associate with each other in their link range, in which the basic 802.11 MAC protocol uses the Distributed Coordination Function (DCF) to share the media between various devices. But use of 802.11 MAC protocol in Ad-Hoc networks affected by different issues such as restricted power capacity, packet loss because of transmission error, various control traffic and failure to avoid packet collision. To solve these problems various protocols have been proposed. But we don�t have any perfect protocol which can resolve the issues related to power management, packet collision and packet loss efficiently. In this research paper, we suggest a new protocol to adjust the upper & lower bounds for the contention window to decrease the number of collisions. As well as it proposes a power control scheme, triggered by the MAC layer to reduce the packet loss, energy wastage and decrease the number of collisions during transmission. The proposed MAC protocol is implemented and performance is compared with existing 802.11 MAC protocol. We computed the Packet Delivery Fraction(PDF), average End-to-End(e-e) delay, average throughput and packet loss in several conditions. We find proposed protocol is comparatively improved than the existing protocol

ALZHEIMER’S DISEASE: A CONSEQUENCE OF IMPAIRED MITOPHAGY?

Neurodegenerative disorders involve complexities of the pathologies, characterized by the progressive loss of neuronal viability, leading to severe physical and cognitive impairments in affected patients. These disorders although may differ in clinical outcomes yet they share common features such as aggregation of neurotoxic metabolites and perturbed cellular and neuronal homeostasis. Mitochondrion is an indispensable organelle for neuronal survival, and its role and place have become critical in research arena of aging and neurodegenaration. The accumulation of damaged mitochondria has been linked to normal aging and multiple age-related disorders including Alzheimer’s disease (AD). Survival and proper function of mitochondria depend on several attributes that include mitochondrial biogenesis and fusion and fission. Mitophagy is an utmost requirement for degradation and removal of damaged mitochondria where the target mitochondria are identified by the autophagosomes and delivered to the lysosome for degradation. Mitophagy plays important roles in mitochondrial homeostasis, neuroprotection, and resistance to neurodegeneration. AD besides other characteristic features involves mitochondrial dysfunctional, bioenergetic deficit, and altered mitophagy. The autophagy/lysosome pathway that removes damaged mitochondria (mitophagy) is compromised in AD, resulting in the accumulation of dysfunctional mitochondria that contribute to synaptic dysfunction and cognitive deficits by triggering Aβ and Tau accumulation through increases in oxidative damage and cellular energy deficits. The present work reviews the various implications of mitophagy in relevance to the pathology of AD