Constraining isocurvature perturbations with the 21 cm emission from minihaloes

We investigate the effects of isocurvature perturbations on the 21 cm radiation from minihaloes (MHs) at high redshifts and examine constraints on the isocurvature amplitude and power spectrum using the next generation of radio telescopes such as the Square Kilometre Array. We find that there is a realistic prospect of observing the isocurvature imprints in the 21 cm emission from MHs, but only if the isocurvature spectral index is close to 3 (i.e. the spectrum is blue). When the isocurvature fraction increases beyond ∼10 per cent of the adiabatic component, we observe an unexpected decline in the 21 cm fluctuations from small-mass MHs, which can be explained by the incorporation small MHs into larger haloes. We perform a detailed Fisher-matrix analysis and conclude that the combination of future cosmic microwave background and 21 cm experiments (such as CMBPol and the Fast Fourier Transform Telescope) is ideal in constraining the isocurvature parameters, but will stop short of distinguishing between cold dark matter and baryon types of isocurvature perturbations, unless the isocurvature fraction is large and the spectrum is blue

A novel integrated dual microneedle-microfluidic impedance flow cytometry for cells detection in suspensions

In this study, a new, simple and cost-effective impedance detection of yeast cell concentration by using a novel integrated dual microneedle-microfluidic impedance flow cytometry was introduced. The reported method for impedance flow cytometry detection utilizes embedded electrode and probe in the microfluidic device to perform measurement of electrical impedance when a presence of cells at sensing area. Nonetheless, this method requires costly and complicatedly fabrication process of electrode. Furthermore, to reuse the fabricated electrode, it also requires intensive and tedious cleaning process. Due to that, a dual microneedle integrated at the half height of the microchannel for cell detection as well as for electrical measurement was demonstrated. A commercial available Tungsten needle was utilized as a dual microneedle. The microneedle was easy to be removed from the disposable PDMS microchannel and can be reused with the simple cleaning process, such as washed by using ultrasonic cleaning. Although this device was low cost, it preserves the core functionality of the sensor, which is capable of detecting the passing cells at sensing area. Therefore, this device is suitable for low cost medical and food safety screening and testing process in developing countries

Progressive changes of regional macular thickness after macular hole surgery with internal limiting membrane peeling

Citation: Kumagai K, Hangai M, Larson E, Ogino N. Progressive changes of regional macular thickness after macular hole surgery with internal limiting membrane peeling. Invest Ophthalmol Vis Sci. 2013;54:4491-4497. DOI:10.1167/iovs.13-11662 PURPOSE. To determine the changes of regional macular thickness after successful macular hole surgery (MHS) with internal limiting membrane (ILM) peeling during a 24-month followup period. METHODS. In a prospective, interventional case study, the authors evaluated 24 eyes of 24 patients who underwent 23-gauge transconjunctival pars plana vitrectomy with triamcinolone-assisted ILM peeling to treat idiopathic macular hole. Examinations were performed before and 1, 2, 3, 6, 9, 12, and 24 months after surgery. Average regional macular thicknesses in the Early Treatment Diabetic Retinopathy Study sectors were measured by spectral-domain optical coherence tomography. RESULTS. The four inner sectors showed a significant reduction in the average retinal thickness at 1 month after surgery (P 0.0001-0.020), and the thickness continued to decrease for 24 months except in the nasal sector. The four outer sectors had a significant increase at postoperative 1 month (P ¼ 0.0003-0.029) and then progressively decreased during the postoperative 24 months. The postoperative regional macular thinning was statistically significant even between 12 and 24 months (P ¼ 0.0007-0.026) in all sectors except in the inner nasal sector (P ¼ 0.13). The postoperative percent reduction rate was significantly different among four inner sectors after postoperative 3 months (P ¼ 0.0029-0.039) in the order of temporal > superior > inferior > nasal sectors. CONCLUSIONS. These results suggest that a progressive macular thinning occurs for at least 2 years with different patterns of the changes in the macular regions after successful MHS with ILM peeling

Dynamic Active Constraints for Surgical Robots using Vector Field Inequalities

Robotic assistance allows surgeons to perform dexterous and tremor-free procedures, but robotic aid is still underrepresented in procedures with constrained workspaces, such as deep brain neurosurgery and endonasal surgery. In these procedures, surgeons have restricted vision to areas near the surgical tooltips, which increases the risk of unexpected collisions between the shafts of the instruments and their surroundings. In this work, our vector-field-inequalities method is extended to provide dynamic active-constraints to any number of robots and moving objects sharing the same workspace. The method is evaluated with experiments and simulations in which robot tools have to avoid collisions autonomously and in real-time, in a constrained endonasal surgical environment. Simulations show that with our method the combined trajectory error of two robotic systems is optimal. Experiments using a real robotic system show that the method can autonomously prevent collisions between the moving robots themselves and between the robots and the environment. Moreover, the framework is also successfully verified under teleoperation with tool-tissue interactions.Comment: Accepted on T-RO 2019, 19 Page