Cardiac Resynchronisation Therapy and its effects on systolic heart failure

Cardiac Resynchronisation Therapy (CRT) is now an established therapeutic option for patients with symptomatic left ventricular systolic dysfunction, broad QRS duration (>120 milliseconds on surface electrocardiogram) and on optimal tolerated medical therapy. The numbers of implants are rising throughout the Westernised world. The United Kingdom has also had a rapid increase in CRT implantation. Despite the large randomised trials which prove clinical effectiveness, there is a realisation that a significant minority of patients who undergo CRT implantation do not derive the anticipated clinical benefit. This has been labelled as non-response with up to 40 percent of patients being affected depending on diagnostic criteria. However potential solutions to a lack of clinical benefit do exist. These include medical optimisation of the patient’s heart failure pharmacotherapy following CRT implantation, and device based optimisation adjusting atrioventricular and ventriculo-ventricular (AV and VV) intervals. Other reasons for a lack of clinical improvement may be explained on pathophysiology which is currently not accounted for in the guidelines and selection criteria. The thesis is therefore dedicated to the exploration of these issues using the dataset from the specialist heart failure pacing clinic at the Royal Brompton Hospital. The study of medical optimisation following CRT implantation observed increased rates of neurohormonal antagonists and anticoagulants when a systematic structured clinical approach was adopted. One potential method of evaluating device based optimisation is impedance cardiography and within chapter V, a cohort of 44 patients underwent device based optimisation with either conventional echocardiographic techniques or impedance cardiography. Though underpowered and a pilot study, the impedance cardiographic method within this cohort performed adequately. Heart failure remains a complex syndrome with complex pathophysiology. One of the potential reasons for non-response is the lack of acknowledgement of other physiological criteria in the selection criteria. The study performed using cardiac magnetic resonance (CMR) imaging to evaluate right ventricular function on cardiovascular outcomes in patients following CRT implantation. Here it was demonstrated that right ventricular dysfunction as assessed by CMR is a powerful predictor of adverse outcomes and of a failure to undergo left ventricular remodelling. The last study chapter was a small pilot study which compared impedance cardiographic performance to echocardiography within an intensive care setting. Whilst the numbers of patients recruited were small (n=6), the adjustment of atrioventricular and ventriculo-ventricular delays did induce a change in haemodynamics. In conclusion the thesis represents studies and work focussed on the problem of lack of clinical benefit experienced by patients following CRT implantation. It has covered a prognosticator and two potential methods for improving the rate of clinical response following CRT implantation.Open Acces

Continuous-variable entanglement distillation over a pure loss channel with multiple quantum scissors

Entanglement distillation is a key primitive for distributing high-quality entanglement between remote locations. Probabilistic noiseless linear amplification based on the quantum scissors is a candidate for entanglement distillation from noisy continuous-variable (CV) entangled states. Being a non-Gaussian operation, quantum scissors is challenging to analyze. We present a derivation of the non-Gaussian state heralded by multiple quantum scissors in a pure loss channel with two-mode squeezed vacuum input. We choose the reverse coherent information (RCI)---a proven lower bound on the distillable entanglement of a quantum state under one-way local operations and classical communication (LOCC), as our figure of merit. We evaluate a Gaussian lower bound on the RCI of the heralded state. We show that it can exceed the unlimited two-way LOCCassisted direct transmission entanglement distillation capacity of the pure loss channel. The optimal heralded Gaussian RCI with two quantum scissors is found to be significantly more than that with a single quantum scissors, albeit at the cost of decreased success probability. Our results fortify the possibility of a quantum repeater scheme for CV quantum states using the quantum scissors.Comment: accepted for publication in Physical Review

How sapient is homo economicus? The evolutionary origins of trade, ethics and economic rationality

The paper argues that economism and, in particular, the individual drive to maximize utility and amass profit are not enough to ensure the efficient functioning of an economy; and that even for elementary economic activities, such as trade, exchange and contracting to occur smoothly, it is essential that human beings be endowed with appropriate social norms, such as a critical level of trustworthiness. This, in turn, implies that an economy's development can depend significantly on whether the citizenry is endowed with the relevant norms. Where these norms come from and how they gather stability remain open questions, though we can get some important insights from theories of evolutionary processes

Resurgence of Second Wave of Pandemic Covid-19 and Its Impact on Physical and Mental Well-Being of Employees & Coping Mechanism

COVID 19 has had a far-reaching impact on the world since it appeared in November / December 2019. No country has escaped the wrath of this pandemic. Even developed countries in Europe, America, South America and various Asian countries were totally inundated with cases of COVID 19. The global healthcare system has completely collapsed and countries struggled to cope with the huge rush of cases. Initially, most governments did not know how to respond to the emerging situation and most countries reacted by imposing strict lockdown and maintaining social distancing protocols by using masks, gloves, sanitizer, PPE kit and by trying to improve healthcare system. The world had not seen such humanitarian crisis since the Spanish Flu of 1918. This second wave of pandemic covid is really a great concern for the organizations as it’s going to have a far-reaching impact on the mental health and wellbeing of people across the globe. As the cases are increasing at such a fast pace in India and death rates are very high, therefore few state governments had to take the decision to impose lockdown and curfews for saving lives. The business world is continuously learning and adapting towards this change of pandemic Covid -19. The second wave of pandemic COVID -19 causing infection rates and death rates very high resulting and increasing incidence and severity of Mucormucosis.Immuno-suppressive treatments are being widely used for the treatment of pandemic COVID -19 infection. People are living in congregating setting and facing more barriers to healthcare. This paper mainly focuses on Resurgence of Pandemic COVID -19 and its impact on people in society including Employees in organizations. This research paper is also studying the impact of the second wave of COVID -19 on physical and mental well-being of people and most importantly coping strategies to be taken into consideration by employers or managers to get more positivity and enthusiasm from their people. This paper also gives insights about Indian central and state government’s approach and efforts to manage this pandemic crisis especially in India during second wave of pandemic COVID -19. This research paper will also give light on few important issues such as crisis management in India, vaccination process and other related issues. Keywords: Second wave of Pandemic COVID -19, Lockdown, Social distancing, COVID protocols, vaccination, physical health and mental health, healthcare, infrastructure, oxygen plants, front line workers. DOI: 10.7176/EJBM/13-10-12 Publication date:May 31st 202

High-dimensional Frequency-Encoded Quantum Information Processing with Passive Photonics and Time-Resolving Detection

In this Letter, we propose a new approach to process high-dimensional quantum information encoded in a photon frequency domain. In contrast to previous approaches based on nonlinear optical processes, no active control of photon energy is required. Arbitrary unitary transformation and projection measurement can be realized with passive photonic circuits and time-resolving detection. A systematic circuit design for a quantum frequency comb with arbitrary size has been given. The criteria to verify quantum frequency correlation has been derived. By considering the practical condition of detector's finite response time, we show that high-fidelity operation can be readily realized with current device performance. This work will pave the way towards scalable and high-fidelity quantum information processing based on high-dimensional frequency encoding

All-photonic multiplexed quantum repeaters based on concatenated bosonic and discrete-variable quantum codes

Long distance quantum communication will require the use of quantum repeaters to overcome the exponential attenuation of signal with distance. One class of such repeaters utilizes quantum error correction to overcome losses in the communication channel. Here we propose a novel strategy of using the bosonic Gottesman-Kitaev-Preskill (GKP) code in a two-way repeater architecture with multiplexing. The crucial feature of the GKP code that we make use of is the fact that GKP qubits easily admit deterministic two-qubit gates, hence allowing for multiplexing without the need for generating large cluster states as required in previous all-photonic architectures based on discrete-variable codes. Moreover, alleviating the need for such clique-clusters entails that we are no longer limited to extraction of at most one end-to-end entangled pair from a single protocol run. In fact, thanks to the availability of the analog information generated during the measurements of the GKP qubits, we can design better entanglement swapping procedures in which we connect links based on their estimated quality. This enables us to use all the multiplexed links so that large number of links from a single protocol run can contribute to the generation of the end-to-end entanglement. We find that our architecture allows for high-rate end-to-end entanglement generation and is resilient to imperfections arising from finite squeezing in the GKP state preparation and homodyne detection inefficiency. In particular we show that long-distance quantum communication over more than 1000 km is possible even with less than 13 dB of GKP squeezing. We also quantify the number of GKP qubits needed for the implementation of our scheme and find that for good hardware parameters our scheme requires around $10^3-10^4$ GKP qubits per repeater per protocol run.Comment: 31 + 25 pages, 40 figure

COVID-19 Diagnosis from Cough Acoustics using ConvNets and Data Augmentation

With the periodic rise and fall of COVID-19 and countries being inflicted by its waves, an efficient, economic, and effortless diagnosis procedure for the virus has been the utmost need of the hour. COVID-19 positive individuals may even be asymptomatic making the diagnosis difficult, but amongst the infected subjects, the asymptomatic ones need not be entirely free of symptoms caused by the virus. They might not show any observable symptoms like the symptomatic subjects, but they may differ from uninfected ones in the way they cough. These differences in the coughing sounds are minute and indiscernible to the human ear, however, these can be captured using machine learning-based statistical models. In this paper, we present a deep learning approach to analyze the acoustic dataset provided in Track 1 of the DiCOVA 2021 Challenge containing cough sound recordings belonging to both COVID-19 positive and negative examples. To perform the classification on the sound recordings as belonging to a COVID-19 positive or negative examples, we propose a ConvNet model. Our model achieved an AUC score percentage of 72.23 on the blind test set provided by the same for an unbiased evaluation of the models. The ConvNet model incorporated with Data Augmentation further increased the AUC-ROC percentage from 72.23 to 87.07. It also outperformed the DiCOVA 2021 Challenge's baseline model by 23% thus, claiming the top position on the DiCOVA 2021 Challenge leaderboard. This paper proposes the use of Mel frequency cepstral coefficients as the feature input for the proposed model.Comment: DiCOVA, top 1st, This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Secret key distillation across a quantum wiretap channel under restricted eavesdropping

The theory of quantum cryptography aims to guarantee unconditional information-theoretic security against an omnipotent eavesdropper. In many practical scenarios, however, the assumption of an all-powerful adversary is excessive and can be relaxed considerably. In this paper we study secret key distillation across a lossy and noisy quantum wiretap channel between Alice and Bob, with a separately parameterized realistically lossy quantum channel to the eavesdropper Eve. We show that under such restricted eavesdropping, the key rates achievable can exceed the secret key distillation capacity against an unrestricted eavesdropper in the quantum wiretap channel. Further, we show upper bounds on the key rates based on the relative entropy of entanglement. This simple restricted eavesdropping model is widely applicable, e.g., to free-space quantum optical communication, where realistic collection of light by Eve is limited by the finite size of her optical aperture. Future work will include calculating bounds on the amount of light Eve can collect under various realistic scenarios.Comment: 14 pages, 19 figures. We welcome comments and suggestion