Developmental trajectory of Caenorhabditis elegans nervous system governs its structural organization

A central problem of neuroscience involves uncovering the principles governing the organization of nervous systems which ensure robustness in brain development. The nematode Caenorhabditis elegans provides us with a model organism for studying this question. In this paper, we focus on the invariant connection structure and spatial arrangement of the neurons comprising the somatic neuronal network of this organism to understand the key developmental constraints underlying its design. We observe that neurons with certain shared characteristics - such as, neural process lengths, birth time cohort, lineage and bilateral symmetry - exhibit a preference for connecting to each other. Recognizing the existence of such homophily helps in connecting the physical location and morphology of neurons with the topological organization of the network. Further, the functional identities of neurons appear to dictate the temporal hierarchy of their appearance during the course of development. Providing crucial insights into principles that may be common across many organisms, our study shows how the trajectory in the developmental landscape constrains the eventual spatial and network topological organization of a nervous system.Comment: 25 pages, 8 figures + 24 pages supplementary materia

A hierarchy index for networks in the brain reveals a complex entangled organizational structure

Networks involved in information processing often have their nodes arranged hierarchically, with the majority of connections occurring in adjacent levels. However, despite being an intuitively appealing concept, the hierarchical organization of large networks, such as those in the brain, are difficult to identify, especially in absence of additional information beyond that provided by the connectome. In this paper, we propose a framework to uncover the hierarchical structure of a given network, that identifies the nodes occupying each level as well as the sequential order of the levels. It involves optimizing a metric that we use to quantify the extent of hierarchy present in a network. Applying this measure to various brain networks, ranging from the nervous system of the nematode Caenorhabditis elegans to the human connectome, we unexpectedly find that they exhibit a common network architectural motif intertwining hierarchy and modularity. This suggests that brain networks may have evolved to simultaneously exploit the functional advantages of these two types of organizations, viz., relatively independent modules performing distributed processing in parallel and a hierarchical structure that allows sequential pooling of these multiple processing streams. An intriguing possibility is that this property we report may be common to information processing networks in general.Comment: 16 pages, 5 figures + 10 pages Supplementary Informatio

Prompt sky localization of compact binary sources using meshfree approximation

The number of gravitational wave signals from the merger of compact binary systems detected in the network of advanced LIGO and Virgo detectors is expected to increase considerably in the upcoming science runs. Once a confident detection is made, it is crucial to reconstruct the source's properties rapidly, particularly the sky position and chirp mass, to follow up on these transient sources with telescopes operating at different electromagnetic bands for multi-messenger astronomy. In this context, we present a rapid parameter estimation (PE) method aided by mesh-free approximations to accurately reconstruct properties of compact binary sources from data gathered by a network of gravitational wave detectors. This approach builds upon our previous algorithm (Pathak et al.\cite{pathak2022rapid}) to expedite the evaluation of the likelihood function and extend it to enable coherent network PE in a ten-dimensional parameter space, including sky position and polarization angle. Additionally, we propose an optimized interpolation node placement strategy during the start-up stage to enhance the accuracy of the marginalized posterior distributions. With this updated method, we can estimate the properties of binary neutron star (BNS) sources in approximately 2.4~(2.7) minutes for the \TaylorF~(\texttt{IMRPhenomD}) signal model by utilizing 64 CPU cores on a shared memory architecture. Furthermore, our approach can be integrated into existing parameter estimation pipelines, providing a valuable tool for the broader scientific community.Comment: 20 pages, 10 figure

Assessment of Educational Environment of Newly Established Medical College by UG Medical Students: A Mixed Method Study

Introduction: Educational environment always play a crucial role in the development of students as well as faculty of any institution. In India, there is a continuous increase in the number of medical colleges and the number of MBBS seats, but the quality of education with quantity is questionable. To answer this question, the present study was planned to know the educational environment in a new Medical Institution that ejected its alumni in 2018. Aim: To analyze the educational environment of a newly established Medical College in eastern Uttar Pradesh. Materials and Methods: The present study was a descriptive cross-sectional which took six months to complete. This study used the Dundee Ready Education Environment Measure (DREEM) questionnaire, open-ended questions and focus group discussions (FGDs). The study was conducted on MBBS students in Government Medical College, Azamgarh, UP. Results: The batch-wise Global DREEM scores were 169.08 (alumni), 156.23 (interns), 168.76 (2015), 164.16 (2016), 176.23 (2017), 176.94 (2018). This demonstrates that the educational environment is satisfactory in all domains and comes under the 3rd category of the educational environment index. The FGDs showed a positive response in all batches but with high variability in scores, which indicates lack of standardization in Medical Education. The open-ended questions’ responses revealed many merits and demerits about five domains. Conclusion: The variability of DREEM score, FGDs and open ended questions denotes the lack of standardization in the Medical Education system and the scores of the Education Environment Index (all domains) must move from category III (satisfactory) to category IV (excellence)

Test of the Second Postulate of Relativity from Gravitational Wave Observations

The second postulate of special relativity states that the speed of light in vacuum is independent of the emitter's motion. Though this claim has been verified in various experiments and observations involving electromagnetic radiation with very high accuracy, such a test for gravitational radiation still needs to be explored. We analyzed data from the LIGO and Virgo detectors to test this postulate for gravitational radiation within the ambit of \textit{emission models}, where the speed of gravitational waves emitted by a source moving with a velocity $v$ relative to a stationary observer is given by ${c' = c + k\,v}$, where $k$ is a constant. We have estimated the upper bound on the 90\% credible interval over $k$ that parameterizes the deviation from the second postulate to be ${k \leq 8.3 \times {10}^{-18}}$ which is several orders of magnitude more stringent compared to previous bounds obtained from electromagnetic observations. The Bayes' factor supports the second postulate, with very strong evidence that the data is consistent with the null hypothesis $k = 0$. This confirms that the speed of gravity is independent of the motion of the emitter, upholding the principle of relativity for gravitational interactions.Comment: 7 pages, 3 figure

Synthesis and Photodetection Properties of Sonochemically Exfoliated Cu0.2Sn0.8Se Nanoparticles

Transition metal chalcogenides (TMCs) with atomically minute structure have shown excessive potential for their optoelectronics field applications and their counterparts. TMCs unique layer dependent properties have pinched increasing consideration of scientists. Here, the high yield synthesis of atomically minute Cu0.2Sn0.8Se nanoparticles has been reported. The nanoparticles are synthesised by sonochemical exfoliation technique. The exfoliated Cu0.2Sn0.8Se nanoparticles have orthorhombic lattice structure which is confirmed from powder X-ray Diffraction with Pnma space group. The lateral morphology of the assynthesized nanoparticles examined under transmission electron microscopy showed them to be of uniform spherical shape. The selected area electron diffraction showed a spot pattern stating the particles to be single crystalline. Moreover, the photodetector based on Cu0.2Sn0.8Se nanoparticles thin film is fabricated. The periodic 670 nm laser illumination of power intensity 3 mW/cm2 is used to study the detector properties. The enhanced photo responsivity and specific detectivity is observed along with fast response. The outstanding detection properties are revealed from the responsivity, specific detectivity, and external quantum efficiency (EQE) of Cu0.2Sn0.8Se nanoparticles-based photodetector

A prospective, multi-centric, observational registry to evaluate performance of Excel™ DES in ‘Real World, All Comers’ patient population

AbstractObjectivesThis study aims to assess the safety and efficacy of a biodegradable polymer-coated Rapamycin-Eluting Stent (Excel) used in conjunction with six-month dual antiplatelet therapy in daily practice.BackgroundThe polymeric material of cardiac stents has been reported to adversely affect the safety profile of the drug-eluting stents and is also suspected to cause serious long-term complications. It has been proposed that the biodegradable polymer coatings may reduce such late-stage adverse effects.MethodsThis is a prospective, multi-center registry of 654 patients from across 9 cardiology centers in India, who were enrolled and exclusively treated with Excel stents between February 2008 and May 2010. The recommended antiplatelet regimen included clopidogrel and aspirin for 6 months period, followed by lifelong aspirin therapy.ResultsThe study population included 46.94% diabetics, 24.31% smokers, 48.93% hypertensives and 14.98% hyperlipidemics. The cumulative rates of major adverse cardiac events were 0.153% at discharge and 1.38% at 12 months. The mean percentage of stenosis was 88.24 ± 9.17% No events occurred between 6 and 12 months.ConclusionsThis multi-center registry study on “real world, all comers” has, thus, showed that EXCEL™ stent which is PLA-coated biodegradable Rapamycin-Eluting Stent exhibited high efficacy and safety profile in treatment of patients undergoing PCI as evidenced by significantly lower rates of MACE and no case of stent thrombosis. There was no event even after DAPT was discontinued after 6 months