The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Applying a COVID-19 Sample-pooling Technique to Forensics Identification of Illicit Drugs

This paper presents a method for materially speeding up the identification process of suspect illicit drugs by pooling samples that require GC-MS analysis. This method can be applied to samples seized from a single suspect that are similar in appearance and therefore meet the Israeli Dangerous Drug Ordinance requirements for sampling. A complementary test (GC, TLC, or FTIR) conducted separately on each of the sampled units can prove conclusively that all units contain the same drug. This study shows that even with large differences in relative weight of mixes in a pool, each drug is easily identifiable by GC-MS and dominant peaks do not overshadow minority substances. By using this method, a narcotics lab can improve its throughput of expert opinions in narcotics cases, and at the same time save resources, extend instrument life, and be more environment-friendly

Applying a COVID-19 Sample-pooling Technique to Forensics Identification of Illicit Drugs

This paper presents a method for materially speeding up the identification process of suspect illicit drugs by pooling samples that require GC-MS analysis. This method can be applied to samples seized from a single suspect that are similar in appearance and therefore meet the Israeli Dangerous Drug Ordinance requirements for sampling. A complementary test (GC, TLC, or FTIR) conducted separately on each of the sampled units can prove conclusively that all units contain the same drug. This study shows that even with large differences in relative weight of mixes in a pool, each drug is easily identifiable by GC-MS and dominant peaks do not overshadow minority substances. By using this method, a narcotics lab can improve its throughput of expert opinions in narcotics cases, and at the same time save resources, extend instrument life, and be more environment-friendly

Killing Mechanism of Stable <i>N</i>‑Halamine Cross-Linked Polymethacrylamide Nanoparticles That Selectively Target Bacteria

Increased resistance of bacteria to disinfection and antimicrobial treatment poses a serious public health threat worldwide. This has prompted the search for agents that can inhibit both bacterial growth and withstand harsh conditions (<i>e.g.</i>, high organic loads). In the current study, <i>N</i>-halamine-derivatized cross-linked polymethacrylamide nanoparticles (NPs) were synthesized by copolymerization of the monomer methacrylamide (MAA) and the cross-linker monomer <i>N</i>,<i>N</i>-methylenebis(acrylamide) (MBAA) and were subsequently loaded with oxidative chlorine using sodium hypochlorite (NaOCl). The chlorinated NPs demonstrated remarkable stability and durability to organic reagents and to repetitive bacterial loading cycles as compared with the common disinfectant NaOCl (bleach), which was extremely labile under these conditions. The antibacterial mechanism of the cross-linked P(MAA-MBAA)-Cl NPs was found to involve generation of reactive oxygen species (ROS) only upon exposure to organic media. Importantly, ROS were not generated upon suspension in water, revealing that the mode of action is target-specific. Further, a unique and specific interaction of the chlorinated NPs with Staphylococcus aureus was discovered, whereby these microorganisms were all specifically targeted and marked for destruction. This bacterial encircling was achieved without using a targeting module (<i>e.g.</i>, an antibody or a ligand) and represents a highly beneficial, natural property of the P(MAA-MBAA)-Cl nanostructures. Our findings provide insights into the mechanism of action of P(MAA-MBAA)-Cl NPs and demonstrate the superior efficacy of the NPs over bleach (<i>i.e.</i>, stability, specificity, and targeting). This work underscores the potential of developing sustainable P(MAA-MBAA)-Cl NP-based devices for inhibiting bacterial colonization and growth

Differential Effects of Prenylation and S-Acylation on Type I and II ROPS Membrane Interaction and Function1[W][OA]

Prenylation primarily by geranylgeranylation is required for membrane attachment and function of type I Rho of Plants (ROPs) and Gγ proteins, while type II ROPs are attached to the plasma membrane by S-acylation. Yet, it is not known how prenylation affects ROP membrane interaction dynamics and what are the functional redundancy and specificity of type I and type II ROPs. Here, we have used the expression of ROPs in mammalian cells together with geranylgeranylation and CaaX prenylation-deficient mutants to answer these questions. Our results show that the mechanism of type II ROP S-acylation and membrane attachment is unique to plants and likely responsible for the viability of plants in the absence of CaaX prenylation activity. The prenylation of ROPs determines their steady-state distribution between the plasma membrane and the cytosol but has little effect on membrane interaction dynamics. In addition, the prenyl group type has only minor effects on ROP function. Phenotypic analysis of the CaaX prenylation-deficient pluripetala mutant epidermal cells revealed that type I ROPs affect cell structure primarily on the adaxial side, while type II ROPs are functional and induce a novel cell division phenotype in this genetic background. Taken together, our studies show how prenyl and S-acyl lipid modifications affect ROP subcellular distribution, membrane interaction dynamics, and function