Conducting Controlled human infection model studies in India is an ethical obligation

Weighing competing obligations and achieving the “greatest balance” of right over wrong guides an individual, an agency or a country in determining what ought to be done in an ethically challenging situation. Conducting controlled human infection model (CHIM) studies in India is one such situation. The ethical challenge in conducting a CHIM study lies in completing the difficult task of introducing standardised, attenuated strains of micro-organisms into normal healthy volunteers, at the same time ensuring the safety of these healthy individuals from potential and completely informed risks in a fashion that is transparent and accountable. The bar is further raised against the background of already fragile public confidence in biomedical research in India; especially when “deliberate” introduction of microbial agents into healthy individuals is involved, with the larger altruistic objective of gain to society as a whole. This paper discusses the uses of CHIM studies with respect to the larger scientific Indian research enterprise of the 21st century. It further explores etic and emic perspectives in conducting such trials in India and seeks to generate an ethical coherence to the justification for conducting CHIM studies in India. The paper deliberates on ethical issues arising out of conducting CHIM studies and reflects on how developing the capacity for CHIM studies in India is likely to strengthen the health research and development sector in the country

Identification of Top Performing Economies

Using seven indicators of the economic performance of 187 countries, the paper identifies the top 50 performers during the decades of 1981-90 and 1991-2000. Five of these indicators are the trend rates of growth over a decade in imports, FDI, capital formation, per capita income and forex reserves. Average inflation rate and HDI are the remaining indicators. Comparison of top performers of the 1980s and the 1990s suggest that high performance in inflation and HDI are the precondition for consistency of high overall performance over time. The paper also examines the interrelationship among the indicators over time.

Constraining Orbital Periods from Nonconsecutive Observations: Period Estimates for Long-Period Planets in Six Systems Observed by K2 During Multiple Campaigns

Most planetary discoveries with the K2 and TESS missions are restricted to short periods because of the limited duration of observation. However, the re-observation of sky area allows for the detection of longer period planets. We describe new transits detected in six candidate planetary systems which were observed by multiple K2 mission campaigns. One of these systems is a multiplanet system with four candidate planets; we present new period constraints for two planets in this system. In the other five systems, only one transit is observed in each campaign, and we derive period constraints from this new data. The period distributions are highly multimodal resulting from missed potential transits in the gap between observations. Each peak in the distribution corresponds to transits at an integer harmonic of the two observed transits. We further detail a generalized procedure to constrain the period for planets with multiple observations with intervening gaps. Because long period photometrically discovered planets are rare, these systems are interesting targets for follow-up observations and confirmation. Specifically, all six systems are bright enough (V = 10.4-12.7) to be amenable to radial velocity follow-up. This work serves as a template for period constraints in a host of similar yet-to-be-discovered planets in long baseline, temporally gapped observations conducted by the TESS mission.Comment: 10 pages, 5 figures; accepted for publication in A

A Substellar Companion to a Hot Star in K2's Campaign 0 Field

The K2 mission has enabled searches for transits in crowded stellar environments very different from the original Kepler mission field. We describe here the reduction and analysis of time series data from K2's Campaign 0 superstamp, which contains the 150 Myr open cluster M35. We report on the identification of a substellar transiting object orbiting an A star at the periphery of the superstamp. To investigate this transiting source, we performed ground based follow-up observations, including photometry with the Las Cumbres Observatory telescope network and high resolution spectroscopy with Keck/High Resolution Echelle Spectrometer. We confirm that the host star is a hot, rapidly rotating star, precluding precision radial velocity measurements. We nevertheless present a statistical validation of the planet or brown dwarf candidate using speckle interferometry from the WIYN telescope to rule out false positive stellar eclipsing binary scenarios. Based on parallax and proper motion data from Gaia Data Release 2 (DR2), we conclude that the star is not likely to be a member of M35, but instead is a background star around 100 pc behind the cluster. We present an updated ephemeris to enable future transit observations. We note that this is a rare system as a hot host star with a substellar companion. It has a high potential for future follow-up, including Doppler tomography and mid-infrared secondary transit observations

A Coupled Experimental and Computational Approach to Quantify Deleterious Hemodynamics, Vascular Alterations, and Mechanisms of Long-Term Morbidity in Response to Aortic Coarctati

Introduction Coarctation of the aorta (CoA) is associated with morbidity despite treatment. Although mechanisms remain elusive, abnormal hemodynamics and vascular biomechanics are implicated. We present a novel approach that facilitates quantification of coarctation-induced mechanical alterations and their impact on vascular structure and function, without genetic or confounding factors. Methods Rabbits underwent thoracic CoA at 10 weeks of age (~ 9 human years) to induce a 20 mm Hg blood pressure (BP) gradient using permanent or dissolvable suture thereby replicating untreated and corrected CoA. Computational fluid dynamics (CFD) was performed using imaging and BP data at 32 weeks to quantify velocity, strain and wall shear stress (WSS) for comparison to vascular structure and function as revealed by histology and myograph results. Results Systolic and mean BP was elevated in CoA compared to corrected and control rabbits leading to vascular thickening, disorganization and endothelial dysfunction proximally and distally. Corrected rabbits had less severe medial thickening, endothelial dysfunction, and stiffening limited to the proximal region despite 12 weeks of normal BP (~ 4 human years) after the suture dissolved. WSS was elevated distally for CoA rabbits, but reduced for corrected rabbits. Discussion These findings are consistent with alterations in humans. We are now poised to investigate mechanical contributions to mechanisms of morbidity in CoA using these methods

All-optical sub-Kelvin sympathetic cooling of a levitated microsphere in vacuum

Funding: UK Engineering and Physical Sciences Research Council (EP/P030017/1).We demonstrate all-optical sympathetic cooling of a laser-trapped microsphere to sub-Kelvin temperatures, mediated by optical binding to a feedback-cooled adjacent particle. Our study opens prospects for multi-particle quantum entanglement and sensing in levitated optomechanics.Publisher PDFPeer reviewe

Laser Writing of Parabolic Micromirrors with a High Numerical Aperture for Optical Trapping and Rotation

On-chip optical trapping systems allow for high scalability and lower the barrier to access. Systems capable of trapping multiple particles typically come with high cost and complexity. Here we present a technique for making parabolic mirrors with micron-size dimensions and high numerical apertures (NA>1). Over 350 mirrors are made by simple CO2 laser ablation of glass followed by gold deposition. We fabricate mirrors of arbitrary diameter and depth at a high throughput rate by carefully controlling the ablation parameters. We use the micromirrors for 3-dimensional optical trapping of microbeads in solution, achieving a maximum optical trap stiffness of 52 pN/{\mu}m/W. We then further demonstrate the viability of the mirrors as in-situ optical elements through the rotation of a vaterite particle using reflected circularly polarized light. The method used allows for rapid and highly customizable fabrication of dense optical arrays.Comment: 6 pages, 5 figure

Laser writing of parabolic micromirrors with a high numerical aperture for optical trapping and rotation

Funding: This work was supported by the UK Engineering and Physical Sciences Research Council (EP/P030017/1 and EP/S014403/1), by the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Program (Grant Agreement No. 819346). HO acknowledges support from the Carnegie Trust for Universities of Scotland (Grant No. RIG007685). KD acknowledges support from the Australian Research Council (Grant No. DP220102303).On-chip optical trapping systems allow for high scalability and lower the barrier to access. Systems capable of trapping multiple particles typically come with high cost and complexity. Here, we present a technique for making parabolic mirrors with micrometer-size dimensions and high numerical apertures (NA > 1). Over 350 mirrors are made by simple CO2 laser ablation of glass followed by gold deposition. We fabricate mirrors of arbitrary diameter and depth at a high throughput rate by carefully controlling the ablation parameters. We use the micromirrors for three-dimensional optical trapping of microbeads in solution, achieving a maximum optical trap stiffness of 52 pN/μm/W. We, then, further demonstrate the viability of the mirrors as in situ optical elements through the rotation of a vaterite particle using reflected circularly polarized light. The method used allows for rapid and highly customizable fabrication of dense optical arrays.Publisher PDFPeer reviewe