Glassy dynamics of partially pinned fluids: an alternative mode-coupling approach

We use a simple mode-coupling approach to investigate glassy dynamics of partially pinned fluid systems. Our approach is different from the mode-coupling theory developed by Krakoviack [Phys. Rev. Lett. 94, 065703 (2005), Phys. Rev. E 84, 050501(R) (2011)]. In contrast to Krakoviack's theory, our approach predicts a random pinning glass transition scenario that is qualitatively the same as the scenario obtained using a mean-field analysis of the spherical p-spin model and a mean-field version of the random first-order transition theory. We use our approach to calculate quantities which are often considered to be indicators of growing dynamic correlations and static point-to-set correlations. We find that the so-called static overlap is dominated by the simple, low pinning fraction contribution. Thus, at least for randomly pinned fluid systems, only a careful quantitative analysis of simulation results can reveal genuine, many-body point-to-set correlations

Design of a Multimodal Fingertip Sensor for Dynamic Manipulation

We introduce a spherical fingertip sensor for dynamic manipulation. It is based on barometric pressure and time-of-flight proximity sensors and is low-latency, compact, and physically robust. The sensor uses a trained neural network to estimate the contact location and three-axis contact forces based on data from the pressure sensors, which are embedded within the sensor's sphere of polyurethane rubber. The time-of-flight sensors face in three different outward directions, and an integrated microcontroller samples each of the individual sensors at up to 200 Hz. To quantify the effect of system latency on dynamic manipulation performance, we develop and analyze a metric called the collision impulse ratio and characterize the end-to-end latency of our new sensor. We also present experimental demonstrations with the sensor, including measuring contact transitions, performing coarse mapping, maintaining a contact force with a moving object, and reacting to avoid collisions.Comment: 6 pages, 2 pages of references, supplementary video at https://youtu.be/HGSdcW_aans. Submitted to ICRA 202

Towards Robust Autonomous Grasping with Reflexes Using High-Bandwidth Sensing and Actuation

Modern robotic manipulation systems fall short of human manipulation skills partly because they rely on closing feedback loops exclusively around vision data, which reduces system bandwidth and speed. By developing autonomous grasping reflexes that rely on high-bandwidth force, contact, and proximity data, the overall system speed and robustness can be increased while reducing reliance on vision data. We are developing a new system built around a low-inertia, high-speed arm with nimble fingers that combines a high-level trajectory planner operating at less than 1 Hz with low-level autonomous reflex controllers running upwards of 300 Hz. We characterize the reflex system by comparing the volume of the set of successful grasps for a naive baseline controller and variations of our reflexive grasping controller, finding that our controller expands the set of successful grasps by 55% relative to the baseline. We also deploy our reflexive grasping controller with a simple vision-based planner in an autonomous clutter clearing task, achieving a grasp success rate above 90% while clearing over 100 items.Comment: 6 pages, 1 page of references, supplementary video at https://youtu.be/f8Coo02Jvdg. Submitted to ICRA 202

Optimal Distance for Normal Gait Speed Testing

Walking speed tests are powerful health screening tools, but variation in protocols present different diagnostic cutoffs. What distance for a gait speed test validly represents overall gait speed is unknown. To determine the optimal testing distance that represents overall gait speed. Vitals and measurements were taken from participants and were instructed to walk at their normal gait speed for 20m through Brower timing gates at every 5m. Speeds from 0-5m, 5-10m, and 10-20m were compared using a mixed effect model. The average speed for 0-5m segment was 1.361 m/s, 5-10m was 1.449 m/s, and the 10-20m average speed was 1.467 m/s. Comparing 0-5m to 5-10m, the estimated difference was 0.088 m/s with a 95% CI between 0.062-0.079 m/s with a p-value \u3c 0.0001. Comparing 0-5m to 10-20m, the estimated difference was 0.106 m/s with a p-value of \u3c0.0001. The estimated 5-10m to 10-20m difference was 0.018 m/s with a p-value of 0.18. The average gait speeds of the 5-10m and 10-20m segments were not significantly different when compared, but significantly different compared to the average gait speed for 0-5m. This was expected because a patient will still be accelerating to their actual walking speed in the first 5m. The most efficient distance for subjects to walk is between 5-10 meters. Using a walk speed test under 5 meters is not advised

Wide-field two-photon microscopy with temporal focusing and HiLo background rejection

Scanningless depth-resolved microscopy is achieved through spatial-temporal focusing and has been demonstrated previously. The advantage of this method is that a large area may be imaged without scanning resulting in higher throughput of the imaging system. Because it is a widefield technique, the optical sectioning effect is considerably poorer than with conventional spatial focusing two-photon microscopy. Here we propose wide-field two-photon microscopy based on spatio-temporal focusing and employing background rejection based on the HiLo microscope principle. We demonstrate the effects of applying HiLo microscopy to widefield temporally focused two-photon microscopy

A moderate increase in dietary zinc reduces DNA strand breaks in leukocytes and alters plasma proteins without changing plasma zinc concentrations.

BackgroundFood fortification has been recommended to improve a population's micronutrient status. Biofortification techniques modestly elevate the zinc content of cereals, but few studies have reported a positive impact on functional indicators of zinc status.ObjectiveWe determined the impact of a modest increase in dietary zinc that was similar to that provided by biofortification programs on whole-body and cellular indicators of zinc status.DesignEighteen men participated in a 6-wk controlled consumption study of a low-zinc, rice-based diet. The diet contained 6 mg Zn/d for 2 wk and was followed by 10 mg Zn/d for 4 wk. To reduce zinc absorption, phytate was added to the diet during the initial period. Indicators of zinc homeostasis, including total absorbed zinc (TAZ), the exchangeable zinc pool (EZP), plasma and cellular zinc concentrations, zinc transporter gene expression, and other metabolic indicators (i.e., DNA damage, inflammation, and oxidative stress), were measured before and after each dietary-zinc period.ResultsTAZ increased with increased dietary zinc, but plasma zinc concentrations and EZP size were unchanged. Erythrocyte and leukocyte zinc concentrations and zinc transporter expressions were not altered. However, leukocyte DNA strand breaks decreased with increased dietary zinc, and the level of proteins involved in DNA repair and antioxidant and immune functions were restored after the dietary-zinc increase.ConclusionsA moderate 4-mg/d increase in dietary zinc, similar to that which would be expected from zinc-biofortified crops, improves zinc absorption but does not alter plasma zinc. The repair of DNA strand breaks improves, as do serum protein concentrations that are associated with the DNA repair process. This trial was registered at clinicaltrials.gov as NCT02861352

Non-descanned multifocal multiphoton microscopy with a multianode photomultiplier tube

Multifocal multiphoton microscopy (MMM) improves imaging speed over a point scanning approach by parallelizing the excitation process. Early versions of MMM relied on imaging detectors to record emission signals from multiple foci simultaneously. For many turbid biological specimens, the scattering of emission photons results in blurred images and degrades the signal-to-noise ratio (SNR). We have recently demonstrated that a multianode photomultiplier tube (MAPMT) placed in a descanned configuration can effectively collect scattered emission photons from each focus into their corresponding anodes significantly improving image SNR for highly scattering specimens. Unfortunately, a descanned MMM has a longer detection path resulting in substantial emission photon loss. Optical design constraints in a descanned geometry further results in significant optical aberrations especially for large field-of-view (FOV), high NA objectives. Here, we introduce a non-descanned MMM based on MAPMT that substantially overcomes most of these drawbacks. We show that we improve signal efficiency up to fourfold with limited image SNR degradation due to scattered emission photons. The excitation foci can also be spaced wider to cover the full FOV of the objective with minimal aberrations. The performance of this system is demonstrated by imaging interneuron morphological structures deep in the brains of living mice.Grant RO1 EY017656National Institutes of Health (U.S.) (9P41EB015871)5 R01 NS0513204R44EB012415National Science Foundation (U.S.) (CBET-0939511)Singapore-MIT Alliance for Research and TechnologyMIT Skoltech InitiativeHamamatsu CorporationDavid H. Koch Institute for Integrative Cancer Research at MIT (Bridge Project Initiative

2020-2021 KSU Concerto Competition Finals

Students of the KSU School of Music perform in the final round of the 2020-2021 Concerto Competition. Winners will perform with the KSU Symphony Orchestra or the KSU Wind Ensemble when health and safety permit. Presented virtually from Morgan Concert Hall of the Bailey Performance Center.https://digitalcommons.kennesaw.edu/musicprograms/2328/thumbnail.jp

Index case finding facilitates identification and linkage to care of children and young persons living with HIV/AIDS in Malawi

OBJECTIVES: Evaluation of a novel index case finding and linkage-to-care programme to identify and link HIV-infected children (1-15 years) and young persons (>15-24 years) to care. METHODS: HIV-infected patients enrolled in HIV services were screened and those who reported untested household members (index cases) were offered home- or facility-based HIV testing and counselling (HTC) of their household by a community health worker (CHW). HIV-infected household members identified were enrolled in a follow-up programme offering home and facility-based follow-up by CHWs. RESULTS: Of the 1567 patients enrolled in HIV services, 1030 (65.7%) were screened and 461 (44.8%) identified as index cases; 93.5% consented to HIV testing of their households and of those, 279 (64.7%) reported an untested child or young person. CHWs tested 711 children and young persons, newly diagnosed 28 HIV-infected persons (yield 4.0%; 95% CI: 2.7-5.6), and identified an additional two HIV-infected persons not enrolled in care. Of the 30 HIV-infected persons identified, 23 (76.6%) were linked to HIV services; 18 of the 20 eligible for ART (90.0%) were initiated. Median time (IQR) from identification to enrolment into HIV services was 4 days (1-8) and from identification to ART start was 6 days (1-8). CONCLUSIONS: Almost half of HIV-infected patients enrolled in treatment services had untested household members, many of whom were children and young persons. Index case finding, coupled with home-based testing and tracked follow-up, is acceptable, feasible and facilitates the identification and timely linkage to care of HIV-infected children and young persons

Intelligent Massive MIMO Systems for Beyond 5G Networks: An Overview and Future Trends

Machine learning (ML) which is a subset of artificial intelligence is expected to unlock the potential of challenging large-scale problems in conventional massive multiple-input-multiple-output (CM-MIMO) systems. This introduces the concept of intelligent massive MIMO (I-mMIMO) systems. Due to the surge of application of different ML techniques in the enhancement of mMIMO systems for existing and emerging use cases beyond fifth-generation (B5G) networks, this article aims to provide an overview of the different aspects of the I-mMIMO systems. First, the characteristics and challenges of the CM-MIMO have been identified. Secondly, the most recent efforts aimed at applying ML to a different aspect of CM-MIMO systems are presented. Thirdly, the deployment of I-mMIMO and efforts towards standardization are discussed. Lastly, the future trends of I-mMIMO-enabled application systems are presented. The aim of this paper is to assist the readers to understand different ML approaches in CM-MIMO systems, explore some of the advantages and disadvantages, identify some of the open issues, and motivate the readers toward future trends