Quality of Service Impact on Edge Physics Simulations for VR

—Mobile HMDs must sacrifice compute performance to achieve ergonomic and power requirements for extended use. Consequently, applications must either reduce rendering and simulation complexity - along with the richness of the experience - or offload complexity to a server. Within the context of edge-computing, a popular way to do this is through render streaming. Render streaming has been demonstrated for desktops and consoles. It has also been explored for HMDs. However, the latency requirements of head tracking make this application much more challenging. While mobile GPUs are not yet as capable as their desktop counterparts, we note that they are becoming more powerful and efficient. With the hard requirements of VR, it is worth continuing to investigate what schemes could optimally balance load, latency and quality. We propose an alternative we call edge-physics: streaming at the scene-graph level from a simulation running on edge-resources, analogous to cluster rendering. Scene streaming is not only straightforward, but compute and bandwidth efficient. The most demanding loops run locally. Jobs that hit the power-wall of mobile CPUs are off-loaded, while improving GPUs are leveraged, maximising compute utilisation. In this paper we create a prototypical implementation and evaluate its potential in terms of fidelity, bandwidth and performance. We show that an effective system which maintains high consistencies on typical edge-links can be easily built, but that some traditional concepts are not applicable, and a better understanding of the perception of motion is required to evaluate such a system comprehensively

Consensus Based Networking of Distributed Virtual Environments.

Distributed Virtual Environments (DVEs) are challenging to create as the goals of consistency and responsiveness become contradictory under increasing latency. DVEs have been considered as both distributed transactional databases and force-reflection systems. Both are good approaches, but they do have drawbacks. Transactional systems do not support Level 3 (L3) collaboration: manipulating the same degree-of-freedom at the same time. Force-reflection requires a client-server architecture and stabilisation techniques. With Consensus Based Networking (CBN), we suggest DVEs be considered as a distributed data-fusion problem. Many simulations run in parallel and exchange their states, with remote states integrated with continous authority. Over time the exchanges average out local differences, performing a distribued-average of a consistent, shared state. CBN aims to build simulations that are highly responsive, but consistent enough for use cases such as the piano-movers problem. CBN's support for heterogeneous nodes can transparently couple different input methods, avoid the requirement of determinism, and provide more options for personal control over the shared experience. Our work is early, however we demonstrate many successes, including L3 collaboration in room-scale VR, 1000's of interacting objects, complex configurations such as stacking, and transparent coupling of haptic devices. These have been shown before, but each with a different technique; CBN supports them all within a single, unified system

Creative destruction in science

Drawing on the concept of a gale of creative destruction in a capitalistic economy, we argue that initiatives to assess the robustness of findings in the organizational literature should aim to simultaneously test competing ideas operating in the same theoretical space. In other words, replication efforts should seek not just to support or question the original findings, but also to replace them with revised, stronger theories with greater explanatory power. Achieving this will typically require adding new measures, conditions, and subject populations to research designs, in order to carry out conceptual tests of multiple theories in addition to directly replicating the original findings. To illustrate the value of the creative destruction approach for theory pruning in organizational scholarship, we describe recent replication initiatives re-examining culture and work morality, working parents\u2019 reasoning about day care options, and gender discrimination in hiring decisions. Significance statement It is becoming increasingly clear that many, if not most, published research findings across scientific fields are not readily replicable when the same method is repeated. Although extremely valuable, failed replications risk leaving a theoretical void\u2014 reducing confidence the original theoretical prediction is true, but not replacing it with positive evidence in favor of an alternative theory. We introduce the creative destruction approach to replication, which combines theory pruning methods from the field of management with emerging best practices from the open science movement, with the aim of making replications as generative as possible. In effect, we advocate for a Replication 2.0 movement in which the goal shifts from checking on the reliability of past findings to actively engaging in competitive theory testing and theory building. Scientific transparency statement The materials, code, and data for this article are posted publicly on the Open Science Framework, with links provided in the article

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Synthesis and Characterization of Snails Venom Peptide as a Potential Inhibitor of NMDA Receptors in Alzheimer’s Disease

Alzheimer’s Disease (AD) is a neurodegenerative disease which is affecting million people globally. In 2021, 6.5 million people in US alone spent billions dollar for their treatment. While there is no cure for AD yet, there are therapeutics in development to slow the progression of AD. The specific aspect of AD which this study focuses on is the inhibition of the N-methyl-D-aspartate (NMDA) receptor. Previous research has shown that, in AD patients, the overactivation of the NMDA receptor leads to an overabundance of Ca+ ions within the nerve cell. This activates digestive enzymes causing premature neuron death which leads to dementia. Memantine has seen use in inhibiting NMDA which slowed the onset of dementia in AD patients. Additionally, cone snails venom peptides have shown potential in blocking the flow of ions through NMDA. In this study, computational screening of 41 Conus venom peptide against NMDA was conducted. Several peptides exhibited strong binding affinity with NMDA. Two peptides, 1M2C and 2I28, showed the binding affinity of -53.52 and -47.95 kcal/mol, respectively. These peptide candidates were synthesized using the standard Fmoc synthesis protocols by CEM Liberty Blue peptide synthesizer. Peptides’ characterizations were then conducted by mass spectrometry. The linear peptide showed two strong peaks at m/z 858.83 and 1715.17 correspond to [M+2H]2+ and [M+H]+ ions, respectively which exactly matched with the theoretical values. Cyclic peptide was synthesized by adding 10% DMSO and stirred for 24-48 hours. Cyclization was confirmed by mass spectrometry which showed the removal of four hydrogen (mass shift by 4) from four cysteine residues and forming disulfide bonds between Cys2-Cys8 and Cys3-Cys16. The performance of these peptides will be evaluated with Alzheimer animal model. The obtained results can accelerate the rational design of snails’ venom peptide inhibitors in the development of Alzheimer’s Disease therapeutics

Outcomes of integrase inhibitor-based antiretroviral therapy in a clinical cohort of treatment-experienced children, adolescents and young adults with HIV infection

Background: Data on integrase strand transfer inhibitor (INSTI) use in children, adolescents and young adults with HIV are limited. We evaluated virologic and safety outcomes following INSTI initiation among treatment-experienced children, adolescents and young adults. Methods: The DC Cohort is a multicenter observational study of individuals receiving HIV care in Washington, DC. This analysis included treatment-experienced participants 0-24 years of age who initiated an INSTI during 2011-2017. Viral suppression (VS) and safety outcomes were quantified. Differences in VS by age, sex and CD4 count were assessed using Kaplan-Meier curves. Results: Of 141 participants (median age 20 years; 35% \u3c18 years; 60% male; 89% Black; 62% perinatally-infected), 35% had VS and 65% lacked VS on INSTI initiation. Dolutegravir was the most commonly prescribed INSTI (55%). Among participants without VS at INSTI initiation, 46% achieved VS after a median of 2.7 months. Participants 13-24 (vs. 0-12) years old (P = 0.011) and participants with CD4 counts \u3c350 (vs. \u3e500) cells/μL were less likely to achieve VS (P \u3c 0.001). Among participants with VS at INSTI initiation, 51% sustained VS through a median of 11.0 months of follow-up; of the 49% with transient viremia, 77% later achieved VS again. There were no safety concerns associated with the use of INSTIs. Conclusions: More than half of treatment-experienced children, adolescents and young adults with detectable viremia at INSTI initiation did not achieve VS, while half of those with prior VS experienced transient viremia. Further evaluation of long-term outcomes associated with INSTI use among children, adolescents and young adults is warranted

Beyond guesswork: how accurate are surgeons at determining the degree of glenoid bone loss in instability surgery?

Background: Accurate measurement of glenoid bone loss (GBL) is critical to preoperative planning in cases of recurrent shoulder instability. The concept of critical bone loss has been established with a value of GBL >13.5% being associated with higher failure rate following arthroscopic Bankart Repair. Advanced imaging, such as magnetic resonance imaging (MRI) scans, can be used to quantify GBL prior to surgery using the best-fit circle technique. Surgeons have traditionally relied on visual inspection of the MRI scan preoperatively or on visual inspection of the glenoid at the time of arthroscopy to determine whether GBL is present. The purpose of this study is to determine if 3 fellowship-trained shoulder surgeons could adequately quantify GBL without using best-fit circle measurements on MRI. Methods: A retrospective review was performed which included 122 patients over an 8-year period that had an arthroscopic Bankart repair performed by 3 fellowship-trained surgeons. In all patients, preoperative MRI scans were retrospectively measured using best-fit circle technique to determine true GBL and compare that to the surgeons’ preoperative and intraoperative estimation of GBL. Results: GBL was correctly identified in only 36% (18/50) of patients when the preoperative best-fit circle measurements were not made. Critical bone loss was missed in 9.8% (12/122) of patients in the study group. The estimated mean bone loss in that group by visual inspection was 11.3% compared to 16% true bone loss measured on MRI. Even in the 18 patients with some identified bone loss prior to surgery, critical bone loss was missed in 6 patients when using visual inspection of the MRI or intraoperative inspection alone. Conclusion: Simple visual inspection of glenoid images on MRI scan and visual inspection of the glenoid at the time of surgery are inaccurate in determining the true extent of GBL especially in cases of subtle bone deficiency. Preoperative planning is dependent on the exact degree of bone deficiency and measurement on the MRI scan using the best-fit circle technique is recommended in all cases of instability surgery

Prevention of Perinatal HIV Transmission in an Area of High HIV Prevalence in the United States

Objective: To evaluate the uptake of perinatal HIV preventive interventions by the risk of perinatal HIV transmission in mother–infant pairs in a high–HIV prevalence area in the US. Study design: This was a retrospective cohort study of mother–infant pairs with perinatal HIV exposure during 2013-2017 managed at a subspecialty pediatric HIV program in Washington, DC. We collected demographic data, maternal HIV history, delivery mode, maternal and infant antiretroviral drug (ARV) use, and infant HIV test results. We compared the uptake of recommended preventive interventions in low-risk (ie, mothers on antiretroviral therapy [ART] with viral suppression) and high-risk (mothers without ART or viral suppression) mother–infant pairs using the Pearson chi-square, Fisher exact, and Wilcoxon rank-sum tests and logistic regression. Results: We analyzed 551 HIV-exposed infants (HEIs) and 542 mothers living with HIV. The majority of mothers received ARVs (95.5%), had HIV RNA ≤1000 copies/mL before delivery (81.9%), and received intrapartum zidovudine (ZDV; 65.5%). The majority of all HEIs were low risk (82.6%) and received postpartum ARVs (98.9%). Among the low-risk infants, 53.2% were delivered via cesarean delivery (CD), and 62.9% and 96.5% were administered intrapartum and postpartum ZDV, respectively. Among high-risk infants, 84.4% were delivered via CD, 78.1% received intrapartum ZDV, and 62.5% received combination ART. Nine high-risk infants acquired HIV perinatally. Conclusion: In an area of high HIV prevalence in the US, a large proportion of low-risk HEIs received intrapartum ZDV and were delivered via CD. We also observed missed opportunities for the prevention of perinatal HIV transmission