An Analysis of Distributed Systems Syllabi With a Focus on Performance-Related Topics

We analyze a dataset of 51 current (2019-2020) Distributed Systems syllabi from top Computer Science programs, focusing on finding the prevalence and context in which topics related to performance are being taught in these courses. We also study the scale of the infrastructure mentioned in DS courses, from small client-server systems to cloud-scale, peer-to-peer, global-scale systems. We make eight main findings, covering goals such as performance, and scalability and its variant elasticity; activities such as performance benchmarking and monitoring; eight selected performance-enhancing techniques (replication, caching, sharding, load balancing, scheduling, streaming, migrating, and offloading); and control issues such as trade-offs that include performance and performance variability.Comment: Accepted for publication at WEPPE 2021, to be held in conjunction with ACM/SPEC ICPE 2021: https://doi.org/10.1145/3447545.3451197 This article is a follow-up of our prior ACM SIGCSE publication, arXiv:2012.0055

A pilot randomized controlled trial of pioglitazone for the treatment of poorly controlled asthma in obesity

Background: Obese asthmatics tend to have poorly controlled asthma, and resistance to standard asthma controller medications. The purpose of this study was to determine the efficacy of pioglitazone, an anti-diabetic medication which can alter circulating adipokines and have direct effects on asthmatic inflammation, in the treatment of asthma in obesity. Methods: A two-center, 12-week, randomized, placebo-controlled, double-blinded trial. Treatments were randomly assigned with concealment of allocation. The primary outcome was difference in change in airway reactivity between participants assigned to pioglitazone versus placebo at 12weeks. Results: Twenty-three participants were randomized to treatment, 19 completed the study. Median airway reactivity, measured by PC20 to methacholine was 1.99 (IQR 3.08) and 1.60 (5.91) mg/ml in placebo and pioglitazone group at baseline, and 2.37 (15.22) and 5.08 (7.42) mg/ml after 12weeks, p=0.38. There was no difference in exhaled nitric oxide, asthma control or lung function between treatment groups over the 12week trial. Participants assigned to pioglitazone gained a significant amount more weight than those assigned to placebo (pioglitazone group mean weight 113.6, CI 94.5-132.7kg at randomization and 115.9, CI 96.9-135.1 at 12weeks; placebo mean weight 127.5, CI 108.4 - 146.6kg at randomization and 124.5, CI 105.4 - 143.6kg at 12weeks; p=0.04). Conclusions: This pilot study suggests limited efficacy for pioglitazone in the treatment of poorly controlled asthma in obesity, and also the potential for harm, given the weight gain in those assigned to active treatment, and the association between increased weight and worse outcomes in asthma. Trial Registration: Clinicaltrials.gov (NCT00634036

Grain and Nutritional Quality Traits of Southwestern U.S. Blue Maize Landraces

Anthocyanin‐rich Southwestern blue maize (Zea mays L.) landraces are receiving interest as functional foods, and commercial production is increasing. We determined variation in kernel color, anthocyanin content, texture, and selected compositional traits of representative varieties. In 2013, eight varieties were grown at four locations in New Mexico. Total kernel anthocyanin content (TAC) and component pigments were measured with spectrophotometry and HPLC, respectively. Oil, protein, starch, and kernel density were determined using NIR spectroscopy and amino acid concentrations using wet chemistry. An average of 49.6 mg/100 g of TAC with a range of 17.6–65.1 mg/100 g was observed. Cyanidin and pelargonidin were major components, and peonidin and succinyl 3‐glucoside were minor components. Low levels of disuccinyl glucoside were detected. Blue kernels were higher in anthocyanin than purple or red kernels. Floury kernels displayed the highest protein and oil contents and the lowest starch content and kernel density. The highest starch and kernel density levels were observed in small flint/dent and pop‐flint/dent kernels. Amino acid content was variable across genotypes and locations

Phytoene Accumulation in the Novel Microalga Chlorococcum sp. Using the Pigment Synthesis Inhibitor Fluridone

Carotenoids are lipophilic pigments found in plants and algae, as well as some bacteria, archaea, and fungi that serve two functions—(1) as light harvesting molecules—primary carotenoids, and (2) as antioxidants, acting against reactive oxygen species–secondary carotenoids. Because of their strong antioxidant properties, they are also valuable for the development of anti-aging and photo-protective cosmetic applications. Of particular interest is the carotenoid phytoene, for its colorless and UV absorption characteristics. In this study, we targeted a reduction of phytoene desaturase (PDS) activity with the pigment-inhibiting herbicide 1-methyl-3-phenyl-5-[3- (trifluoromethyl)phenyl]pyridin-4-one (fluridone), which leads to the over-accumulation of phytoene in the recently characterized microalgal strain Chlorococcum sp. (UTEX B 3056). After post-incubation with fluridone, phytoene levels were measured at ~33 ug/mg cell tissue, as opposed to non-detectable levels in control cultures. Hence, the novel microalga Chlorococcum sp. is a viable candidate for the production of the high-value carotenoid phytoene and subsequent applications in cosmeceuticals, as well as more obvious nutraceutical and pharmaceutical applications

Transient peak-strain matching partially recovers the age-impaired mechanoadaptive cortical bone response

Mechanoadaptation maintains bone mass and architecture; its failure underlies age-related decline in bone strength. It is unclear whether this is due to failure of osteocytes to sense strain, osteoblasts to form bone or insufficient mechanical stimulus. Mechanoadaptation can be restored to aged bone by surgical neurectomy, suggesting that changes in loading history can rescue mechanoadaptation. We use non-biased, whole-bone tibial analyses, along with characterisation of surface strains and ensuing mechanoadaptive responses in mice at a range of ages, to explore whether sufficient load magnitude can activate mechanoadaptation in aged bone. We find that younger mice adapt when imposed strains are lower than in mature and aged bone. Intriguingly, imposition of short-term, high magnitude loading effectively primes cortical but not trabecular bone of aged mice to respond. This response was regionally-matched to highest strains measured by digital image correlation and to osteocytic mechanoactivation. These data indicate that aged bone’s loading response can be partially recovered, non-invasively by transient, focal high strain regions. Our results indicate that old murine bone does respond to load when the loading is of sufficient magnitude, and bones’ age-related adaptation failure may be due to insufficient mechanical stimulus to trigger mechanoadaptation

The Mini Astrophysical MeV Background Observatory (MAMBO) CubeSat Mission

The origin of the cosmic diffuse gamma-ray (CDG) background in the 0.3 – 30 MeV energy range is a mystery that has persisted for over 40 years. The Mini Astrophysical MeV Background Observatory (MAMBO) is a CubeSat mission concept motivated by the fact that, since the MeV CDG is relatively bright, only a small detector is required to make high-quality measurements of it. Indeed, the sensitivity of space-based gamma-ray instruments to the CDG is limited not by size, but by the locally generated instrumental background produced by interactions of energetic particles in spacecraft materials. Comparatively tiny CubeSat platforms provide a uniquely quiet environment relative to previous gamma-ray science missions. The MAMBO mission will provide the best measurements ever made of the MeV CDG spectrum and angular distribution, utilizing two key innovations: 1) low instrumental background on a 12U CubeSat platform; and 2) an innovative shielded spectrometer design that simultaneously measures signal and background. Enabling technologies include the use of compact silicon photomultipliers (SiPMs) for scintillator readout, and a tagged calibration source for real-time gain adjustment. We describe the MAMBO instrument, readout, commercial 12U bus systems, and mission concept in detail, including simulations and laboratory measurements demonstrating the key measurement concept