Noisy Non-Adaptive Group Testing: A (Near-)Definite Defectives Approach

The group testing problem consists of determining a small set of defective items from a larger set of items based on a number of possibly-noisy tests, and is relevant in applications such as medical testing, communication protocols, pattern matching, and many more. We study the noisy version of the problem, where the output of each standard noiseless group test is subject to independent noise, corresponding to passing the noiseless result through a binary channel. We introduce a class of algorithms that we refer to as Near-Definite Defectives (NDD), and study bounds on the required number of tests for vanishing error probability under Bernoulli random test designs. In addition, we study algorithm-independent converse results, giving lower bounds on the required number of tests under Bernoulli test designs. Under reverse $Z$-channel noise, the achievable rates and converse results match in a broad range of sparsity regimes, and under $Z$-channel noise, the two match in a narrower range of dense/low-noise regimes. We observe that although these two channels have the same Shannon capacity when viewed as a communication channel, they can behave quite differently when it comes to group testing. Finally, we extend our analysis of these noise models to the symmetric noise model, and show improvements over the best known existing bounds in broad scaling regimes.Comment: Submitted to IEEE Transactions on Information Theor

Analysis of the Australian web threat landscape

One in approximately eight Australian IPs are exposed to one or more web threats on any typical day, finds this report released by an Australian Research Council (ARC) Linkage Project involving Trend Micro and Deakin University. The researchers’ analysed malicious activity from over 200,000,000 web requests per day from Australia, with around 400,000 of these issued to malicious web pages.Abstract This report discusses threats on the Australian web landscape. We analyse web logs and provide statistics on what is happening to the average Australian user of the world-wide web. The analysis covers aspects such as the volume and timing of web threats attacking Australians and the source geography of the malicious activity. We look at a case study of a web attack that had global reach and describe the impact of this attack on Australian web users

How Remote Work is Shaking Up the U.S. Workforce: Research on the Recent Shift to Remote Work

As the COVID-19 pandemic swept across the United States and lingered, it brought many new norms in the workplace. At the top of that list is the number of employees now working remotely. Though remote work is not a new concept, mandated lockdown restrictions beginning in March of 2020 prevented most citizens from working in their business offices. Companies were challenged to re-evaluate business practices and determine whether their employees could produce work from home. There have been benefits recognized in the past for remote work, including employee life balance. The environmental benefits of people working remotely are possibly the most appealing, and those benefits were felt during the pandemic, as polluting transportation emissions decreased. New ways of communication are the specific focus of employers, as they attempt to keep employee engagement high. Knowledge sharing and involvement present challenges for companies, but research on ways to achieve these things looks promising. While remote work remains a foreign and unwelcome way to work for many, the United States continues to plow through the barriers of traditional work methods. Many people continue moving out of large metropolitan cities to lower their cost of living, but some employers are responding to this move by lowering salaries to meet cost of living standards in each employee’s new area of residency. Time will tell if this response from employers will reduce the number of those aspiring to escape big city life. The effects of remote work on employees’ mental health and their performance are key indicators of whether remote work is considered successful. However, these two indicators contradict one another. This leaves companies confused as to how to establish the balance between remote work and in-person work moving forward. Yet employers continue finding ways to make the most out of the current remote work climate

Short-Term Changes in LDL Density and Lipoprotein Particle Number in Trained Men After 3 Different Modes of Exercise

Short-Term Changes in LDL Density and Lipoprotein Particle Number in Trained Men After 3 Different Modes of Exercise Jonathan M. Oliver, Steven E. Martin, Shawn P. Glowacki, Wade Womack, John S. Green, FACSM, and Stephen F. Crouse, FACSM, Texas A&M University, TX 77843, (Sponsor: S. F. Crouse) PURPOSE: To determine the short-term changes in LDL density and lipoprotein particle number after three different modes of exercise in trained men. METHODS: Twenty seven subjects were randomly assigned to complete either (resistance [RE], endurance [EE], or combination resistance/endurance [CE]) exercise. Fasting blood samples were obtained 24 h before (baseline) and 24 h after exercise. The average group characteristics were as follows: [RE: n = 9, age = 22 + 1 yr, weight = 75.7 ± 4 kg, %fat = 14 + 1, V.O2peak = 3.43 + 0.1 L/min], [EE: n = 9, age = 23 + 1 yr, weight = 87.7 ± 4 kg, %fat = 17 + 3, V.O2peak = 4.0 + 0.10 L/min], [CE: n = 9, age = 22 + 1 yr, weight = 99.7 + 5 kg, %fat = 21 + 3, V.O2peak = 3.94 + 0.10 L/min]. RESULTS: of a 3 (GROUP) x 2 (TIME) ANOVA (repeated for TIME) for all dependent variables were as follows: No significant GROUP x TIME interactions were determined for any of the plasma volume adjusted dependent variables. A GROUP main effect was observed for LDL density. LDL density was significantly higher in both RE and EE groups compared to the CE group. A TIME main effect was observed for LDL density and the number of LDL3 and LDL4 particles. Significant increases in LDL density (1.0314 g/cm2 to 1.0316 g/cm2), and the number of LDL3 (7.8%), and LDL4 (7.1%) particles occurred 24 h after exercise compared to baseline values. CONCLUSION: These data show that regardless of exercise group, LDL density and the number of LDL3 and LDL4 particles were significantly elevated 24 h after a single exercise session in trained men

Hadronic form factors for rare semileptonic BB decays

We discuss first results for the computation of short distance contributions to semileptonic form factors for the rare $B$ decays $B \to K^{*} \ell^+\ell^-$ and $B_s \to \phi \ell^+ \ell^-$. Our simulations are based on RBC/UKQCD's $N_f=2+1$ ensembles with domain wall light quarks and the Iwasaki gauge action. For the valence $b$-quark we chose the relativistic heavy quark action.Comment: 7 pages, 1 table, 3 figures, presented at the 33rd International Symposium on Lattice Field Theory (Lattice2015), July 14-18, 2015, Kobe, Japa