Impact of community masking on COVID-19: A cluster-randomized trial in Bangladesh

Persuading people to mask Even in places where it is obligatory, people tend to optimistically overstate their compliance for mask wearing. How then can we persuade more of the population at large to act for the greater good? Abaluck et al . undertook a large, cluster-randomized trial in Bangladesh involving hundreds of thousands of people (although mostly men) over a 2-month period. Colored masks of various construction were handed out free of charge, accompanied by a range of mask-wearing promotional activities inspired by marketing research. Using a grassroots network of volunteers to help conduct the study and gather data, the authors discovered that mask wearing averaged 13.3% in villages where no interventions took place but increased to 42.3% in villages where in-person interventions were introduced. Villages where in-person reinforcement of mask wearing occurred also showed a reduction in reporting COVID-like illness, particularly in high-risk individuals. —CA

Formation mechanism of super cluster over the tropics

A large-scale cloud phenomenon was analyzed to understand its internal structure, organization and movement. A westward moving uncommon super cluster was shown to have developed in the study region while each cloud cluster moved FJESE. The super cluster has horizontal length 2000 km, life time more than 2 days, very low TBB (<210 K) cloud area ~40× 104 km2 and moved westward with a speed of ~6 m/s. These features are some what different from the usual properties of super cluster as reported in several works. It was found that new clouds successively formed and interacted between themselves, and organized to form cloud clusters. The cloud clusters merged with the old large cluster to take part in the maintenance of super cluster. The propagation speed and the direction of the super cluster was followed by the formation of new cluster.

The Effect of ­High-Tech Clusters on the Productivity of Top Inventors

The high-tech sector is concentrated in a small number of cities. The ten largest clusters in computer science, semiconductors, and biology account for 69 percent, 77 percent, and 59 percent of all US inventors, respectively. Using longitudinal data on 109,846 inventors, I find that geographical agglomeration results in significant productivity gains. When an inventor moves to a city with a large cluster of inventors in the same field, she experiences a sizable increase in the number and quality of patents produced. The presence of significant productivity externalities implies that the agglomeration of inventors generates large gains in the aggregate amount of innovation produced in the United States. (JEL D62, J24, L60, O31, 034, R32)

Tracks on films and multi-charged clusters

When conducting experiments on the electric explosion of titanium foil in water, a “strange” radiation was detected, leaving dotted traces on the film. The velocity of the carriers of this radiation was estimated as 20–40 m/s, and their energy, estimated by the Coulomb drag mechanism, turned out to be equal to 700 MeV. Subsequently, it was found that similar traces are formed at various types of high-current arc discharges, both of artificial and natural origin. Many solutions have been proposed to explain the nature of “strange” radiation, but none of them describes the details of the process of formation of dotted traces. We believe that these traces on the film could appear due to the action of charged micron-sized clusters. The possibility of the existence of clusters in the form of a nucleus from a certain number of similarly charged ions enclosed in a spherical shell of water molecules is shown. The force of the Coulomb repulsion of ions is compensated by the compression force of the shell polarized by the inhomogeneous electric field created by the nuclear charge. As the cluster approaches the surface of the film, a cluster with a small charge separates from it. It is accelerated in the electric field of a “large” cluster to energy of about 1 GeV. Having received a recoil momentum, a large cluster moves away from the film, braking in an inhomogeneous electric field, and then “falls” onto it again, and the process is repeated.

Phylogenomic and comparative genomic analyses of species of the family Pseudomonadaceae: Proposals for the genera Halopseudomonas gen. nov. and Atopomonas gen. nov., merger of the genus Oblitimonas with the genus Thiopseudomonas, and transfer of some misclassified species of the genus Pseudomonas into other genera

The evolutionary relationships among species of the family Pseudomonadaceae were examined based on 255 available genomes representing >85 % of the species from this family. In a phylogenetic tree based on concatenated sequences of 118 core proteins, most species of the genus Pseudomonas grouped within one large cluster which also included members of the genera Azotobacter and Azomonas . Within this large cluster 18–30 clades/subclades of species of the genus Pseudomonas consisting of between 1 and 36 species, were observed. However, a number of species of the genus Pseudomonas branched outside of this main cluster and were interspersed among other genera of the family Pseudomonadaceae . This included a strongly supported clade (Pertucinogena clade) consisting of 19 mainly halotolerant species. The distinctness of this clade from all other members of the family Pseudomonadaceae is strongly supported by 24 conserved signature indels (CSIs) in diverse proteins that are exclusively found in all members of this clade. Nine uncharacterized members of the genus Pseudomonas also shared these CSIs and they branched within the Pertucinogena clade, indicating their affiliation to this clade. On the basis of the strong evidence supporting the distinctness of the Pertucinogena clade, we are proposing transfer of species from this clade into a novel genus Halopseudomonas gen. nov. Pseudomonas caeni also branches outside of the main cluster and groups reliably with Oblitimonas alkaliphila and Thiopseudomonas denitrificans . Six identified CSIs are uniquely shared by these three species and we are proposing their integration into the emended genus Thiopseudomonas , which has priority over the name Oblitimonas . We are also proposing transfer of the deep-branching Pseudomonas hussainii , for which 22 exclusive CSIs have been identified, into the genus Atopomonas gen. nov. Lastly, we present strong evidence that the species Pseudomonas cissicola and Pseudomonas geniculata are misclassified into the genus Pseudomonas and that they are specifically related to the genera Xanthomonas and Stenotrophomonas , respectively. In addition, we are also reclassifying ‘Pseudomonas acidophila’ as Paraburkholderia acidicola sp. nov. (Type strain: G-6302=ATCC 31363=BCRC 13035).

The Role of Phylogenetics in Unravelling Patterns of HIV Transmission towards Epidemic Control: The Quebec Experience (2002–2020)

Phylogenetics has been advanced as a structural framework to infer evolving trends in the regional spread of HIV-1 and guide public health interventions. In Quebec, molecular network analyses tracked HIV transmission dynamics from 2002–2020 using MEGA10-Neighbour-joining, HIV-TRACE, and MicrobeTrace methodologies. Phylogenetics revealed three patterns of viral spread among Men having Sex with Men (MSM, n = 5024) and heterosexuals (HET, n = 1345) harbouring subtype B epidemics as well as B and non-B subtype epidemics (n = 1848) introduced through migration. Notably, half of new subtype B infections amongst MSM and HET segregating as solitary transmissions or small cluster networks (2–5 members) declined by 70% from 2006–2020, concomitant to advances in treatment-as-prevention. Nonetheless, subtype B epidemic control amongst MSM was thwarted by the ongoing genesis and expansion of super-spreader large cluster variants leading to micro-epidemics, averaging 49 members/cluster at the end of 2020. The growth of large clusters was related to forward transmission cascades of untreated early-stage infections, younger at-risk populations, more transmissible/replicative-competent strains, and changing demographics. Subtype B and non-B subtype infections introduced through recent migration now surpass the domestic epidemic amongst MSM. Phylodynamics can assist in predicting and responding to active, recurrent, and newly emergent large cluster networks, as well as the cryptic spread of HIV introduced through migration.

CRISPR-Cas9-mediated Large Cluster Deletion and Multiplex Genome Editing in Paenibacillus polymyxa

Clustered regularly interspaced short palindromic repeats (CRISPR) system has rapidly advanced genetic engineering research. The system has been applied for different genetic engineering purposes in multiple organisms including the quite rarely explored Paenibacillus polymyxa. Only limited studies on CRISPR-based system have been described for this highly interesting and versatile bacterium. Here, we demonstrated the utilization of a Cas9-based system to realize 32.8 kb deletion of genomic region by using a single targeting sgRNA. Large cluster deletion was successfully performed with remarkable efficiency of 97 %. Furthermore, we also exploited the system for multiplexing by editing of two distantly located genes at once. We investigated double gene knockouts as well as simultaneous gene integrations and reached editing efficiencies of 78 % and 50 %, respectively. The findings reported in this study are anticipated to accelerate future research in P. polymyxa and related species.