Some Lessons Learned Running Virtual Reality Experiments Out of the Laboratory

In the past twelve months, our team has had to move rapidly from conducting most of our user experiments in a laboratory setting, to running experiments in the wild away from the laboratory and without direct synchronous oversight from an experimenter. This has challenged us to think about what types of experiment we can run, and to improve our tools and methods to allow us to reliably capture the necessary data. It has also offered us an opportunity to engage with a more diverse population than we would normally engage with in the laboratory. In this position paper we elaborate on the challenges and opportunities, and give some lessons learned from our own experience

Weapons Make the Man (Larger): Formidability Is Represented as Size and Strength in Humans

In order to determine how to act in situations of potential agonistic conflict, individuals must assess multiple features of a prospective foe that contribute to the foe's resource-holding potential, or formidability. Across diverse species, physical size and strength are key determinants of formidability, and the same is often true for humans. However, in many species, formidability is also influenced by other factors, such as sex, coalitional size, and, in humans, access to weaponry. Decision-making involving assessments of multiple features is enhanced by the use of a single summary variable that encapsulates the contributions of these features. Given both a) the phylogenetic antiquity of the importance of size and strength as determinants of formidability, and b) redundant experiences during development that underscore the contributions of size and strength to formidability, we hypothesize that size and strength constitute the conceptual dimensions of a representation used to summarize multiple diverse determinants of a prospective foe's formidability. Here, we test this hypothesis in humans by examining the effects of a potential foe's access to weaponry on estimations of that individual's size and strength. We demonstrate that knowing that an individual possesses a gun or a large kitchen knife leads observers to conceptualize him as taller, and generally larger and more muscular, than individuals who possess only tools or similarly mundane objects. We also document that such patterns are not explicable in terms of any actual correlation between gun ownership and physical size, nor can they be explained in terms of cultural schemas or other background knowledge linking particular objects to individuals of particular size and strength. These findings pave the way for a fuller understanding of the evolution of the cognitive systems whereby humans – and likely many other social vertebrates – navigate social hierarchies

GaInP/GaAs dual junction solar cells on Ge/Si epitaxial templates

In this study, we report synthesis of large area (> 2 cm^2) crack-free GaInP/GaAs double junction solar cells on 50 mm diameter Ge/Si templates fabricated using wafer bonding and ion implantation induced layer transfer techniques. Defect removal from the template film and film surface prior to epitaxial growth was found to be critical to achievement of high open circuit voltage and efficiency. Cells grown on templates prepared with chemical mechanical polishing in addition a wet chemical etch show comparable performance to control devices grown on bulk Ge substrates. Current-voltage (I–V) data under AM 1.5 illumination indicate that the short circuit current is comparable in templated and control cells, but the open circuit voltage is slightly lower (2.08V vs. 2.16V). Spectral response measurements indicate a drop in open circuit voltage due to a slight lowering of the top GaInP cell band gap. The drop in band gap is due to a difference in the indium composition in the two samples caused by the different miscut (9° vs. 6°) of the two kinds of substrates

Reduced Expression of Inflammatory Genes in Deceased Donor Kidneys Undergoing Pulsatile Pump Preservation

Background The use of expanded criteria donor kidneys (ECD) had been associated with worse outcomes. Whole gene expression of pre-implantation allograft biopsies from deceased donor kidneys (DDKs) was evaluated to compare the effect of pulsatile pump preservation (PPP) vs. cold storage preservation (CSP) on standard and ECD kidneys. Methodology/Principal Findings 99 pre-implantation DDK biopsies were studied using gene expression with GeneChips. Kidneys transplant recipients were followed post transplantation for 35.8 months (range = 24–62). The PPP group included 60 biopsies (cold ischemia time (CIT) = 1,367+/−509 minutes) and the CSP group included 39 biopsies (CIT = 1,022+/−485 minutes) (P Conclusions/Significance Inflammation was the most important up-regulated pattern associated with pre-implantation biopsies undergoing CSP even when the PPP group has a larger number of ECD kidneys. No significant difference was observed in delayed graft function incidence and graft function post-transplantation. These findings support the use of PPP in ECD donor kidneys

5Gen: A Framework for Prototyping Applications Using Multilinear Maps and Matrix Branching Programs

Secure multilinear maps (mmaps) have been shown to have remarkable applications in cryptography, such as program obfuscation and multi-input functional encryption (MIFE). To date, there has been little evaluation of the performance of these applications. In this paper we initiate a systematic study of mmap-based constructions. We build a general framework, called 5Gen, to experiment with these applications. At the top layer we develop an optimizing compiler that takes in a high-level program and compiles it to an optimized matrix branching program needed for the applications we consider. Next, we optimize and experiment with several obfuscators and MIFE constructions and evaluate their performance. The 5Gen framework is modular and can easily accommodate new mmap constructions as well as new obfuscators and MIFE constructions. 5Gen is an open-source tool that can be used by other research groups to experiment with a variety of mmap-based constructions

Evidence for proton acceleration up to TeV energies based on VERITAS and Fermi-LAT observations of the Cas A SNR

We present a study of $\gamma$-ray emission from the core-collapse supernova remnant Cas~A in the energy range from 0.1GeV to 10TeV. We used 65 hours of VERITAS data to cover 200 GeV - 10 TeV, and 10.8 years of \textit{Fermi}-LAT data to cover 0.1-500 GeV. The spectral analysis of \textit{Fermi}-LAT data shows a significant spectral curvature around $1.3 \pm 0.4_{stat}$ GeV that is consistent with the expected spectrum from pion decay. Above this energy, the joint spectrum from \textit{Fermi}-LAT and VERITAS deviates significantly from a simple power-law, and is best described by a power-law with spectral index of $2.17\pm 0.02_{stat}$ with a cut-off energy of $2.3 \pm 0.5_{stat}$ TeV. These results, along with radio, X-ray and $\gamma$-ray data, are interpreted in the context of leptonic and hadronic models. Assuming a one-zone model, we exclude a purely leptonic scenario and conclude that proton acceleration up to at least 6 TeV is required to explain the observed $\gamma$-ray spectrum. From modeling of the entire multi-wavelength spectrum, a minimum magnetic field inside the remnant of $B_{\mathrm{min}}\approx150\,\mathrm{\mu G}$ is deduced.Comment: 33 pages, 9 Figures, 6 Table

A review of sample analysis at mars-evolved gas analysis laboratory analog work supporting the presence of perchlorates and chlorates in gale crater, mars

Funding Information: The research reviewed in this paper was funded by the Mars Science Laboratory (MSL) project office. M.-P.Z. acknowledges funding from the Ministerio de Ciencia e Innovacion (ref. PID2019-104205GB-C21). The authors are grateful to the engineers and scientists of the MSL Curiosity team, who have made the mission possible and the reported data available. The authors would also like to thank the two anonymous reviewers who provided careful reviews that increased the quality of this manuscript. The authors would like to remember and recognize the contributions of Rafael Navarro-Gonzalez, a dedicated SAM and HABIT team member who passed away on 28 January 2021. Navarro-Gonzalez, who was a distinguished researcher, conducted laboratory experiments that demonstrated that chloromethanes could form through a reaction between perchlorates and organics during sample heating, which greatly advanced our understanding of perchlorates and organic detection on Mars. Data Availability Statement: SAM data are publicly available through the NASA Planetary Data System at: http://pds-geosciences.wustl.edu/missions/msl/sam.htm, which was updated in March 2021. See references for the original research articles that contain the data reviewed in this paper.Peer reviewedPublisher PD

Dark Matter Constraints from a Joint Analysis of Dwarf Spheroidal Galaxy Observations with VERITAS

We present constraints on the annihilation cross section of WIMP dark matter based on the joint statistical analysis of four dwarf galaxies with VERITAS. These results are derived from an optimized photon weighting statistical technique that improves on standard imaging atmospheric Cherenkov telescope (IACT) analyses by utilizing the spectral and spatial properties of individual photon events. We report on the results of $\sim$230 hours of observations of five dwarf galaxies and the joint statistical analysis of four of the dwarf galaxies. We find no evidence of gamma-ray emission from any individual dwarf nor in the joint analysis. The derived upper limit on the dark matter annihilation cross section from the joint analysis is $1.35\times 10^{-23} {\mathrm{ cm^3s^{-1}}}$ at 1 TeV for the bottom quark ($b\bar{b}$) final state, $2.85\times 10^{-24}{\mathrm{ cm^3s^{-1}}}$ at 1 TeV for the tau lepton ($\tau^{+}\tau^{-}$) final state and $1.32\times 10^{-25}{\mathrm{ cm^3s^{-1}}}$ at 1 TeV for the gauge boson ($\gamma\gamma$) final state.Comment: 14 pages, 9 figures, published in PRD, Ascii tables containing annihilation cross sections limits are available for download as ancillary files with readme.txt file description of limit