Gravitational fields with sources, regular black holes, quasiblack holes, and analogue black holes

We discuss recent developments in gravitational fields with sources, regular black holes, quasiblack holes, and analogue black holes, related to the talks presented at the corresponding Parallel Session AT3 of the 13th Marcel Grossmann Meeting.Comment: Report of the Parallel Session AT3 at the Marcel Grossmann Meeting 13, Stockholm 2012, Proceedings of the Conference. 9 page

Quasinormal Modes Beyond Kerr

The quasinormal modes (QNMs) of a black hole spacetime are the free, decaying oscillations of the spacetime, and are well understood in the case of Kerr black holes. We discuss a method for computing the QNMs of spacetimes which are slightly deformed from Kerr. We mention two example applications: the parametric, turbulent instability of scalar fields on a background which includes a gravitational QNM, and the shifts to the QNM frequencies of Kerr when the black hole is weakly charged. This method may be of use in studies of black holes which are deformed by external fields or are solutions to alternative theories of gravity.Comment: Proceedings of the Sant Cugat Forum on Astrophysics (2014). Session on 'Gravitational Wave Astrophysics.' 7 page

Neural correlates of cognitive control of reaching movements in the dorsal premotor cortex of rhesus monkeys

Mirabella G, Pani P, Ferraina S. Neural correlates of cognitive control of reaching movements in the dorsal premotor cortex of rhesus monkeys. J Neurophysiol 106: 1454-1466, 2011. First published June 22, 2011; doi: 10.1152/jn.00995.2010.-Canceling a pending movement is a hallmark of voluntary behavioral control because it allows us to quickly adapt to unattended changes either in the external environment or in our thoughts. The countermanding paradigm allows the study of inhibitory processes of motor acts by requiring the subject to withhold planned movements in response to an infrequent stop-signal. At present the neural processes underlying the inhibitory control of arm movements are mostly unknown. We recorded the activity of single units in the rostral and caudal portion of the dorsal premotor cortex (PMd) of monkeys trained in a countermanding reaching task. We found that among neurons with a movement-preparatory activity, about one-third exhibit a modulation before the behavioral estimate of the time it takes to cancel a planned movement. Hence these neurons exhibit a pattern of activity suggesting that PMd plays a critical role in the brain networks involved in the control of arm movement initiation and suppression.Mirabella G, Pani P, Ferraina S. Neural correlates of cognitive control of reaching movements in the dorsal premotor cortex of rhesus monkeys. J Neurophysiol 106: 1454-1466, 2011. First published June 22, 2011; doi: 10.1152/jn.00995.2010.-Canceling a pending movement is a hallmark of voluntary behavioral control because it allows us to quickly adapt to unattended changes either in the external environment or in our thoughts. The countermanding paradigm allows the study of inhibitory processes of motor acts by requiring the subject to withhold planned movements in response to an infrequent stop-signal. At present the neural processes underlying the inhibitory control of arm movements are mostly unknown. We recorded the activity of single units in the rostral and caudal portion of the dorsal premotor cortex (PMd) of monkeys trained in a countermanding reaching task. We found that among neurons with a movement-preparatory activity, about one-third exhibit a modulation before the behavioral estimate of the time it takes to cancel a planned movement. Hence these neurons exhibit a pattern of activity suggesting that PMd plays a critical role in the brain networks involved in the control of arm movement initiation and suppression

A novel ringdown amplitude-phase consistency test

The ringdown signal emitted during a binary black hole coalescence can be modeled as a linear superposition of the characteristic damped modes of the remnant black hole that get excited during the merger phase. While checking the consistency of the measured frequencies and damping times against the Kerr BH spectrum predicted by General Relativity~(GR) is a cornerstone of strong-field tests of gravity, the consistency of measured excitation amplitudes and phases have been largely left unexplored. For a nonprecessing, quasi-circular binary black hole merger, we find that GR predicts a narrow region in the space of mode amplitude ratio and phase difference, independently of the spin of the binary components. % Using this unexpected result, we develop a new null test of strong-field gravity which demands that the measured amplitudes and phases of different ringdown modes should lie within this narrow region predicted by GR. We call this the \emph{amplitude-phase consistency test} and introduce a procedure for performing it using information from the ringdown signal. Lastly, we apply this test to the GW190521 event, using the multimodal ringdown parameters inferred by Capano et al.~(2021)~\cite{Capano:2021etf}. While ringdown measurements errors for this event are large, we show that GW190521 is consistent with the amplitude-phase consistency test. Our test is particularly well suited for accommodating multiple loud ringdown detections as those expected in the near future, and can be used complementarily to standard black-hole spectroscopy as a proxy for modified gravity, compact objects other than black holes, and binary precession

Geodetic precession and strong gravitational lensing in the dynamical Chern-Simons modified gravity

We have investigated the geodetic precession and the strong gravitational lensing in the slowly-rotating black hole in the dynamical Chern-Simons modified gravity theory. We present the formulas of the orbital period $T$ and the geodetic precession angle $\Delta\Theta$ for the timelike particles in the circular orbits around the black hole, which shows that the change of the geodetic precession angle with the Chern-Simons coupling parameter $\xi$ is converse to the change of the orbital period with $\xi$ for fixed $a$. We also discuss the effects of the Chern-Simons coupling parameter on the strong gravitational lensing when the light rays pass close to the black hole and obtain that for the stronger Chern-Simons coupling the prograde photons may be captured more easily, and conversely, the retrograde photons is harder to be captured in the slowly-rotating black hole in the dynamical Chern-Simons modified gravity. Supposing that the gravitational field of the supermassive central object of the Galaxy can be described by this metric, we estimated the numerical values of the main observables for gravitational lensing in the strong field limit.Comment: 19 pages, 5 figures, more clarifications and references added, accepted for publication in Classical and Quantum Gravit

Blockchain-based raw material shipping with PoC in Hyperledger Composer

In today’s world, a lot of various kinds of raw materials are shipped from one place to another as per the requirement of industries. This shipping process involved many multiple levels with multiple personalities or authorities. The intermediates may be influenced by some illegal external factors and there may be some theft or modification in the raw material which is in the shipping process. This generates a significant loss if the material is of high cost. Presently, the advancements in information technology precede a method to restrict this loss and it is blockchain. Blockchain technology is an essential feature in enabling a comprehensive view of events back to origination. The shipping chain of raw materials that provides integrity and tamper resistance for raw materials in the shipping process is proposed in the manuscript. we have also provided proof of concept (PoC) in Hyperledger Composer with performance evaluation.info:eu-repo/semantics/publishedVersio

Involving medical students in re-orienting health services: a photovoice study

Introduction: Healthcare reorientation aims for health services focused not exclusively on diseases but also on prevention and health promotion. The implementation depends strongly on professionals' willingness to actively participate in the reorientation. An effective strategy to boost reorientation is to reorient education and role definition of future professionals. This paper examines whether photovoice can be a suitable method to i) increase future health professionals' awareness of users' needs and expectations; and ii) enable a process of critical reflection on role definition and health services organisation. Methods: One hundred and seventy-two medical students participated in the photovoice project. Participants were asked to produce one photo combined with a caption, responding to a pre-identified question: "What is, in your opinion, the main aspect affecting users' satisfaction/dissatisfaction in a healthcare facility?". Participants discussed their photos in group discussions (n = 16) and participated in data analysis sessions (n = 4). Results: Participants' contributions revolved around how services were delivered (e.g., kindness, accessibility, attention to additional needs) rather than the service provided. The students showed their empathic side and proposed smart and inclusive solutions to improve overall users' experience. Conclusions: This study demonstrated the value of using photovoice to reach medical students and to integrate health promotion into their professional identities. The photovoice process, teamwork, and discussions opened a breach into traditional thinking regarding aspects of healthcare services that are taken for granted or are overlooked. Furthermore, participants' proposals often implied a change in the behaviour of professionals - their future selves - towards patients and low-cost improvements of organisational practices

Association of Kinesthetic and Read-Write Learner with Deep Approach Learning and Academic Achievement

Background: The main purpose of the present study was to further investigate study processes, learning styles, and academic achievement in medical students.Methods: A total of 214 (mean age 22.5 years) first and second year students - preclinical years - at the Asian Institute of Medical Science and Technology (AIMST) University School of Medicine, in Malaysia participated.  There were 119 women (55.6%) and 95 men (44.4%).   Biggs questionnaire for determining learning approaches and the VARK questionnaire for determining learning styles were used.  These were compared to the student’s performance in the assessment examinations.Results: The major findings were 1) the majority of students prefer to study alone, 2) most students employ a superficial study approach, and 3) students with high kinesthetic and read-write scores performed better on examinations and approached the subject by deep approach method compared to students with low scores.  Furthermore, there was a correlation between superficial approach scores and visual learner’s scores.Discussion: Read-write and kinesthetic learners who adopt a deep approach learning strategy perform better academically than do the auditory, visual learners that employ superficial study strategies.   Perhaps visual and auditory learners can be encouraged to adopt kinesthetic and read-write styles to enhance their performance in the exams

Real-time neural signals decoding onto off-the-shelf DSP processors for neuroprosthetic applications.

The control of upper limb neuroprostheses through the peripheral nervous system (PNS) can allow restoring motor functions in amputees. At present, the important aspect of the real-time implementation of neural decoding algorithms on embedded systems has been often overlooked, notwithstanding the impact that limited hardware resources have on the efficiency/effectiveness of any given algorithm. Present study is addressing the optimization of a template matching based algorithm for PNS signals decoding that is a milestone for its real-time, full implementation onto a floating-point Digital Signal Processor (DSP). The proposed optimized real-time algorithm achieves up to 96% of correct classification on real PNS signals acquired through LIFE electrodes on animals, and can correctly sort spikes of a synthetic cortical dataset with sufficiently uncorrelated spike morphologies (93% average correct classification) comparably to the results obtained with top spike sorter (94% on average on the same dataset). The power consumption enables more than 24 hours processing at the maximum load, and latency model has been derived to enable a fair performance assessment. The final embodiment demonstrates the real-time performance onto a low-power off-the-shelf DSP, opening to experiments exploiting the efferent signals to control a motor neuroprosthesis