Information Capacity of Vesicle Release in Neuro-Spike Communication

© 1997-2012 IEEE. Information transmission in the nervous system is performed through the propagation of spikes among neurons, which is done by vesicle release to chemical synapses. Understanding the fundamentals of this communication can lead to the implementation of bio-inspired nanoscale communication paradigms. In this letter, we utilize a realistic pool-based model for vesicle release and replenishment in hippocampal pyramidal neurons and evaluate the capacity of information transmission in this process by modeling it as a binary channel with memory. Then, we derive a recurrence relation for the number of available vesicles, which is used to find successful bit transmission probabilities and mutual information between input and output. Finally, we evaluate the spiking probability that maximizes mutual information and derive the capacity of the channel

The Role Of HR Managers In Developing Intellectual Capital: A Comparative Case Study And Viewpoints On Some Selected Companies

In modern times, the role of human resource (HR) managers has changed as HR policies are planned in accordance with the changing global environment. Their role has expanded to include team building and development of intellectual capital (IC). Workforce diversity has driven many CEOs and HR directors to develop a systematic method for dealing with and ensuring cooperation from the workforce in order to maintain organizational discipline. Rapid advancement, innovations, and changing business trends provide a platform for HR managers to formulate strategies and develop IC to lead the organization in a better manner. This case study research proposes two models - Employees’ Commitment Model (ECM) and Organizational Commitment Model (OCM) - which explain the methodology and techniques for developing IC in modern companies. Further, these models are applied to some selected companies. ECM pertains to developing an individual’s IC, while OCM presents the organizational strategy for adopting and developing IC in modern companies. In a rapidly changing global environment, service-oriented activities are in high demand across sectors. Consequently, HR managers are willing to innovate and invest in IC. Management tools of training, coaching, dealing, and instilling a sense of ownership best develop a company’s IC. Until a few decades back, companies invested in the production processes; later, the focus shifted to technology. Today, the focus is on workers’ knowledge or investment in IC

New chromosome numbers in the genus Trigonella L. (Fabaceae)from Turkey

Somatic chromosome numbers of 45 Trigonella L. (Fabaceae), collected from different localities in Turkey was examined. Chromosome numbers were determined as 2n = 14, 16, 30 and 46. B chromosome was also observed in somatic cells of some taxa (Trigonella arcuata C.A. Meyer and Trigonella procumbens (Besser) Reichb.). In addition, one or two satellites were observed in some taxa (Trigonella lunata Boiss., Trigonella velutina Boiss., Trigonella strangulata Boiss., Trigonella crassipes Boiss. and Trigonella cariensis Boiss.).Keywords: Chromosome number, Leguminosae, Trigonell

Transmitter and Receiver Architectures for Molecular Communications: A Survey on Physical Design with Modulation, Coding, and Detection Techniques

Inspired by nature, molecular communications (MC), i.e., the use of molecules to encode, transmit, and receive information, stands as the most promising communication paradigm to realize the nanonetworks. Even though there has been extensive theoretical research toward nanoscale MC, there are no examples of implemented nanoscale MC networks. The main reason for this lies in the peculiarities of nanoscale physics, challenges in nanoscale fabrication, and highly stochastic nature of the biochemical domain of envisioned nanonetwork applications. This mandates developing novel device architectures and communication methods compatible with MC constraints. To that end, various transmitter and receiver designs for MC have been proposed in the literature together with numerable modulation, coding, and detection techniques. However, these works fall into domains of a very wide spectrum of disciplines, including, but not limited to, information and communication theory, quantum physics, materials science, nanofabrication, physiology, and synthetic biology. Therefore, we believe it is imperative for the progress of the field that an organized exposition of cumulative knowledge on the subject matter can be compiled. Thus, to fill this gap, in this comprehensive survey, we review the existing literature on transmitter and receiver architectures toward realizing MC among nanomaterial-based nanomachines and/or biological entities and provide a complete overview of modulation, coding, and detection techniques employed for MC. Moreover, we identify the most significant shortcomings and challenges in all these research areas and propose potential solutions to overcome some of them.This work was supported in part by the European Research Council (ERC) Projects MINERVA under Grant ERC-2013-CoG #616922 and MINERGRACE under Grant ERC-2017-PoC #780645

Fundamentals of molecular information and communication science

© 1963-2012 IEEE. Molecular communication (MC) is the most promising communication paradigm for nanonetwork realization since it is a natural phenomenon observed among living entities with nanoscale components. Since MC significantly differs from classical communication systems, it mandates reinvestigation of information and communication theoretical fundamentals. The closest examples of MC architectures are present inside our own body. Therefore, in this paper, we investigate the existing literature on intrabody nanonetworks and different MC paradigms to establish and introduce the fundamentals of molecular information and communication science. We highlight future research directions and open issues that need to be addressed for revealing the fundamental limits of this science. Although the scope of this development encompasses wide range of applications, we particularly emphasize its significance for life sciences by introducing potential diagnosis and treatment techniques for diseases caused by dysfunction of intrabody nanonetworks

Data-Agnostic Model Poisoning against Federated Learning: A Graph Autoencoder Approach

This paper proposes a novel, data-agnostic, model poisoning attack on Federated Learning (FL), by designing a new adversarial graph autoencoder (GAE)-based framework. The attack requires no knowledge of FL training data and achieves both effectiveness and undetectability. By listening to the benign local models and the global model, the attacker extracts the graph structural correlations among the benign local models and the training data features substantiating the models. The attacker then adversarially regenerates the graph structural correlations while maximizing the FL training loss, and subsequently generates malicious local models using the adversarial graph structure and the training data features of the benign ones. A new algorithm is designed to iteratively train the malicious local models using GAE and sub-gradient descent. The convergence of FL under attack is rigorously proved, with a considerably large optimality gap. Experiments show that the FL accuracy drops gradually under the proposed attack and existing defense mechanisms fail to detect it. The attack can give rise to an infection across all benign devices, making it a serious threat to FL.Comment: 15 pages, 10 figures, submitted to IEEE Transactions on Information Forensics and Security (TIFS

Analysis of information flow in MISO neuro-spike communication channel with synaptic plasticity

Communication among neurons is the most promising technique for biocompatible nanonetworks. This necessitates the thorough communication theoretical analysis of information transmission among neurons. The information flow in neuro-spike communication channel is regulated by the ability of neurons to change their synaptic strengths over time, i.e. synaptic plasticity. Thus, the performance evaluation of the nervous nanonetwork is incomplete without considering the influence of synaptic plasticity. Hence, in this paper, we provide a comprehensive model for multiple-input single-output (MISO) neuro-spike communication by integrating the spike timing dependent plasticity (STDP) into existing channel model. We simulate this model for a realistic scenario with correlated inputs and varying spiking threshold. We show that plasticity is strengthening the correlated input synapses at the expense of weakening the synapses with uncorrelated inputs. Moreover, a nonlinear behavior in signal transmission is observed with changing spiking threshold.This work was supported in part by the ERC projects MINERVA (ERC-2013-CoG #616922) and the ERC Proof of Concept project MINRGRACE (ERC-2017-PoC #780645)

Performance analysis for capacitive electrical neural interfaces

Neural interfaces will pave the way for novel treatment methods for neural disorders, which are due to communication problems in nervous system. Such disorders include spinal cord injuries, Alzheimer's and Multiple Sclerosis. In this work, we present a novel neural stimulator, which will act as the transmitter part of a neural interface. We perform in detail physical analysis of such a device for the first time, considering the electrostatic and capacitive effects. We also establish the stimulation requirements of the post-synaptic neuron and support our findings with COMSOL simulations. This work will pave the way to the design of more efficient neural stimulators.This work was supported in part by the ERC project MINERVA (ERC-2013-CoG #616922), and the ERC Project MINERGRACE (ERC-2018-PoC #780645)

Follow-up observations of pulsating subdwarf B stars: Multisite campaigns on PG 1618+563B and PG 0048+091

We present follow-up observations of pulsating subdwarf B (sdB) stars as part of our efforts to resolve the pulsation spectra for use in asteroseismological analyses. This paper reports on multisite campaigns of the pulsating sdB stars PG 1618+563B and PG 0048+091. Data were obtained from observatories placed around the globe for coverage from all longitudes. For PG 1618+563B, our five-site campaign uncovered a dichotomy of pulsation states: Early during the campaign the amplitudes and phases (and perhaps frequencies) were quite variable while data obtained late in the campaign were able to fully resolve five stable pulsation frequencies. For PG 0048+091, our five-site campaign uncovered a plethora of frequencies with short pulsation lifetimes. We find them to have observed properties consistent with stochastically excited oscillations, an unexpected result for subdwarf B stars. We discuss our findings and their impact on subdwarf B asteroseismology.Comment: 50 pages including 17 figures and 10 tables. Accepted for publication in the Astrophysical Journa