A Physicist View of COVID-19 Airborne Infection through Convective Airflow in Indoor Spaces
covid-19, novel coronavirus, Airborne infection, indoor spaces
General Idea: Naturally produced droplets from humans (such as those produced by breathing, talking, sneezing, and coughing) include several types of cells (e.g., epithelial cells and cells of the immune system), physiological electrolytes contained in mucous and saliva (e.g. Na+, K+, Cl-), as well as, potentially, several infectious agents (e.g. bacteria, fungi, and viruses). In response to the novel coronavirus SARS-CoV-2 epidemic, which has become a major public health issue worldwide, we provide a concise overview of airborne germ transmission as seen from a physics perspective. We also study whether coronavirus aerosols can travel far from the immediate neighbourhood and get airborne with the convective currents developed within confined spaces. Methodology: Methods of fluid dynamics are utilized to analyse the behavior of various-size airborne droplets containing the virus. Study Findings: We show that existing vortices in the air can make a location far away from the source of the virus be more dangerous than a nearby (e.g., 6 feet away) location. Practical Implications: Our study reveals that it seems reasonable to adopt additional infection-control measures to the recommended 6 feet social distancing. We provide a recommendation that could help to slow down the spread of the virus.
Luis Alfredo Anchordoqui, Eugene M. Chudnovsky
Public aspects of medicine, Neoplasms. Tumors. Oncology. Including cancer and carcinogens
A Physics Modeling Study of COVID-19 Transport in Air
aerosol, covid-19, SARS-CoV-2, Transport, Airborne infection
Objectives: Health threat from COVID-19 airborne infection has become a public emergency of international concern. During the ongoing coronavirus pandemic, people have been advised by the Centers for Disease Control and Prevention to maintain social distancing of at least 2 m to limit the risk of exposure to the coronavirus. Experimental data, however, show that infected aerosols and droplets trapped inside a turbulent puff cloud can travel 7 to 8 m. We carry out a physics modeling study for COVID-19 transport in air. Methodology: We propose a nuclear physics analogy-based modeling of the complex gas cloud and its payload of pathogen-virions. We estimate the puff effective stopping range adapting the high-energy physics model that describes the slow down of α-particles (in matter) via interactions with the electron cloud. Analysis Findings: We show that the cloud stopping range is proportional to the diameter of the puff times its density. We use our puff model to determine the average density of the buoyant fluid in the turbulent cloud. A fit to the experimental data yields , where and are the average density of the puff and the air. We demonstrate that temperature variation could cause an O (≲ ±8%) effect in the puff stopping range for extreme ambient cold or warmth. We also demonstrate that aerosols and droplets can remain suspended for hours in the air. Therefore, once the puff slows down sufficiently, and its coherence is lost, the eventual spreading of the infected aerosols becomes dependent on the ambient air currents and turbulence.
Luis Alfredo Anchordoqui, James B. Dent, Thomas J. Weiler
A Pilot-Scale Supercritical Carbon Dioxide Extraction to Valorize Colombian Mango Seed Kernel
Mangifera indica L, circular economy, essential fatty acids, fruit by-products, response surface methodology, valorization strategy
Colombian mango production, which exceeded 261,000 t in 2020, generates about 40% of the whole fruit as solid waste, of which more than 50% are seed kernels (over 52,000 t solid by-product); though none is currently used for commercial purposes. This study reports the results of the supercritical carbon dioxide (scCO2) extraction of an oil rich in essential fatty acids (EFAs) from revalorized mango seed kernels and the optimization of the process by the Response Surface Methodology (RSM). In pilot-scale scCO2 experiments, pressure (23 MPa–37 MPa) and temperature (52 °C–73 °C) were varied, using 4.5 kg of CO2. The highest experimental oil extraction yield was 83 g/kg (37 MPa and 63 °C); while RSM predicted that 84 g/kg would be extracted at 35 MPa and 65 °C. Moreover, by fine-tuning pressure and temperature it was possible to obtain an EFA-rich lipid fraction in linoleic (37 g/kg) and α-linolenic (4 g/kg) acids, along with a high oleic acid content (155 g/kg), by using a relatively low extraction pressure (23 MPa), which makes the process a promising approach for the extraction of oil from mango waste on an industrial scale, based on a circular economy model.
Leidy J. Cerón-Martínez, Andrés M. Hurtado-Benavides, Alfredo Ayala-Aponte, Liliana Serna-Cock, Diego F. Tirado
A planarian nidovirus expands the limits of RNA genome size.
RNA viruses are the only known RNA-protein (RNP) entities capable of autonomous replication (albeit within a permissive host environment). A 33.5 kilobase (kb) nidovirus has been considered close to the upper size limit for such entities; conversely, the minimal cellular DNA genome is in the 100-300 kb range. This large difference presents a daunting gap for the transition from primordial RNP to contemporary DNA-RNP-based life. Whether or not RNA viruses represent transitional steps towards DNA-based life, studies of larger RNA viruses advance our understanding of the size constraints on RNP entities and the role of genome size in virus adaptation. For example, emergence of the largest previously known RNA genomes (20-34 kb in positive-stranded nidoviruses, including coronaviruses) is associated with the acquisition of a proofreading exoribonuclease (ExoN) encoded in the open reading frame 1b (ORF1b) in a monophyletic subset of nidoviruses. However, apparent constraints on the size of ORF1b, which encodes this and other key replicative enzymes, have been hypothesized to limit further expansion of these viral RNA genomes. Here, we characterize a novel nidovirus (planarian secretory cell nidovirus; PSCNV) whose disproportionately large ORF1b-like region including unannotated domains, and overall 41.1-kb genome, substantially extend the presumed limits on RNA genome size. This genome encodes a predicted 13,556-aa polyprotein in an unconventional single ORF, yet retains canonical nidoviral genome organization and expression, as well as key replicative domains. These domains may include functionally relevant substitutions rarely or never before observed in highly conserved sites of RdRp, NiRAN, ExoN and 3CLpro. Our evolutionary analysis suggests that PSCNV diverged early from multi-ORF nidoviruses, and acquired additional genes, including those typical of large DNA viruses or hosts, e.g. Ankyrin and Fibronectin type II, which might modulate virus-host interactions. PSCNV's greatly expanded genome, proteomic complexity, and unique features-impressive in themselves-attest to the likelihood of still-larger RNA genomes awaiting discovery.
Amir Saberi, Anastasia A Gulyaeva, John L Brubacher, Phillip A Newmark, Alexander E Gorbalenya
Biology (General), Immunologic diseases. Allergy
A pluriatividade das famílias rurais no Nordeste e no Sul do Brasil: pobreza rural e políticas públicas The pluriactivity of rural households in the Brazilian Northeast and South: rural poverty and public policies
Pluriatividade agrícola, Políticas Públicas, Public policies, family farm, famílias rurais, pluriactivity, pobreza rural, rural poverty
O artigo desfaz a ideia de que as famílias rurais pluriativas encontram ambientes favoráveis ao seu crescimento em regiões com economias locais mais dinâmicas e modernas. A pesquisa está apoiada em informações processadas a partir dos microdados da Pesquisa Nacional por Amostra de Domicílios - PNAD (1992 a 1999 e 2001 a 2005). Defende-se que, no caso da Região Sul, o crescimento (ou o não crescimento) da pluriatividade - e sua influência sobre o conjunto da agricultura familiar - depende fundamentalmente de concepções e ações políticas (políticas públicas). No Nordeste, a pluriatividade cresce associada à pobreza no interior da região.The paper aims to undo the idea that pluriactivity finds favorable environment to its growth in regions with dynamic and modern local economies. The research is based on information processing from the microdata of the Pesquisa Nacional por Amostra de Domicílios - PNAD (from 1992 to 1999 and from 2001 to 2005). This paper also points out that, in the case of the South region, the growth (or not growth) of pluriactivity - and its influence over family farms - depends fundamentally on political conceptions and political actions. In the Northeast, pluriactivity increases associated to poverty in interior areas of the region.
Economics as a science, Economic history and conditions
A política brasileira de segurança alimentar e nutricional: concepção e resultados
Fome zero. Segurança alimentar e nutricional. Direito humano à alimentação
O artigo discute a utilização do conceito de Segurança Alimentar e Nutricional no desenho do Projeto Fome Zero e a sua implementação a partir de diversos programas que tiveram início na década passada. Essa política pública é o resultado de uma trajetória histórica e de um novo contexto internacional no qual o combate à fome passou a ser associado ao reconhecimento de direitos por parte do Estado. Após apresentar alguns resultados o artigo conclui chamando a atenção para a necessidade de aperfeiçoar programas ligados ao abastecimento, educação alimentar e nutricional e agricultura urbana, de forma a viabilizar o funcionamento de um sistema integrado de Segurança Alimentar e Nutricional.
Revista Segurança Alimentar e Nutricional
https://periodicos.sbu.unicamp.br/ojs/index.php/san/article/view/8634614
Agriculture (General), Nutrition. Foods and food supply
A política de produção das áreas verdes municipais: análise histórica e projetual
História do planejamento urbano, Indicadores de análise, Pesquisa acadêmica em área de prática projetual, Sistemas de áreas verdes
A partir do século XX, a Administração Municipal de São Paulo passou a formular planos que norteavam a política para as áreas verdes públicas. Neste artigo discutimos as modificações observadas em duas experiências distintas, ocorridas, respectivamente, em 1974 e 2014. A análise desdobra-se em duas perspectivas: 1. com base em indicadores históricos, fundamentada na leitura de documentos oficiais; e 2. a partir de indicadores projetuais, nos quais são examinadas as práticas projetuais dos arquitetos envolvidos em cada experiência analisada. Para tanto, são descritos os modos como os indicadores foram formulados, bem como seu emprego nesta análise. Os resultados mostram uma tendência histórica de ênfase progressiva nos valores de conservação e recuperação ambiental, e diminuição da importância do papel social dos parques e áreas verdes urbanas, levando a modificações significativas na função do projeto arquitetônico para essas áreas.
Matheus de Vasconcelos Casimiro, Ana Gabriela Godinho Lima
Pós: Revista do Programa de Pós-Graduação em Arquitetura e Urbanismo da FAUUSP
https://www.revistas.usp.br/posfau/article/view/150212
Urban groups. The city. Urban sociology, Architecture
A post-synaptic scaffold at the origin of the animal kingdom.
The evolution of complex sub-cellular structures such as the synapse requires the assembly of multiple proteins, each conferring added functionality to the integrated structure. Tracking the early evolution of synapses has not been possible without genomic information from the earliest branching animals. As the closest extant relatives to the Eumetazoa, Porifera (sponges) represent a pivotal group for understanding the evolution of nervous systems, because sponges lack neurons with clearly recognizable synapses, in contrast to eumetazoan animals.We show that the genome of the demosponge Amphimedon queenslandica possesses a nearly complete set of post-synaptic protein homologs whose conserved interaction motifs suggest assembly into a complex structure. In the critical synaptic scaffold gene, dlg, residues that make hydrogen bonds and van der Waals interactions with the PDZ ligand are 100% conserved between sponge and human, as is the motif organization of the scaffolds. Expression in Amphimedon of multiple post-synaptic gene homologs in larval flask cells further supports the existence of an assembled structure. Among the few post-synaptic genes absent from Amphimedon, but present in Eumetazoa, are receptor genes including the entire ionotropic glutamate receptor family.Highly conserved protein interaction motifs and co-expression in sponges of multiple proteins whose homologs interact in eumetazoan synapses indicate that a complex protein scaffold was present at the origin of animals, perhaps predating nervous systems. A relatively small number of crucial innovations to this pre-existing structure may represent the founding changes that led to a post-synaptic element.
Onur Sakarya, Kathryn A Armstrong, Maja Adamska, Marcin Adamski, I-Fan Wang, Bruce Tidor, Bernard M. Degnan, Todd H Oakley, Kenneth S. Kosik
A potential hypothesis for 2019-nCoV infection therapy through delivery of recombinant ACE2 by red blood cell-hitchhiking
2019ncov, ACE2, nanoparticles, Drug Delivery, RBC hitchhiking
Abstract A novel infectious disease, caused by 2019 Novel Coronavirus (2019-nCoV) is responsible for the recent outbreak of severe respiratory disease. The 2019-nCoV spread rapidly and reaching epidemic proportions in many countries of the world. ACE2 was identified as a key receptor for 2019-nCoV infections. Excessive form of soluble ACE2 rescues cellular ACE2 activity which has a protective role in acute lung failure and neutralizes the virus. The short half-life of ACE2 is a major limitation to its practical application. Nanoparticle-based drug delivery systems are one of the most widely investigated approaches for developing novel therapies for a variety of diseases. Nevertheless, nanoparticles suffer from the rapid removal from the bloodstream by the reticuloendothelial system (RES). A noncovalent attachment of nanoparticles to RBCs increases their half-life in blood and allows transient accumulation in the lungs, while decreases their uptake by the liver and spleen. Connecting the recombinant ACE2 into the surface of nanoparticles that were attached to RBCs can be a potential therapeutic approach for 2019-nCoV infection through increasing their lung targeting to naturalize the virus and also acting as a bioreactor in the blood circulation to decrease serum level of Angiotensin II and protects lungs from injury/ARDS.
Zahra Sadat Aghili, Seyed Abbas Mirzaei, Mehdi Banitalebi-Dehkordi
A potential role for Galectin-3 inhibitors in the treatment of COVID-19
The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), the causative agent of coronavirus disease 2019 (COVID-19), has been declared a global pandemic by the World Health Organization. With no standard of care for the treatment of COVID-19, there is an urgent need to identify therapies that may be effective in treatment. Recent evidence has implicated the development of cytokine release syndrome as the major cause of fatality in COVID-19 patients, with elevated levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) observed in patients. Galectin-3 (Gal-3) is an animal lectin that has been implicated in the disease process of a variety of inflammatory conditions. Inhibitors of the small molecule Gal-3 have been shown to reduce the levels of both IL-6 and TNF-α in vitro and have shown anti-inflammatory effects in vivo. Additionally, a key domain in the spike protein of β-coronaviridae, a genus which includes SARS-CoV2, is nearly identical in morphology to human Gal-3. These spike proteins are critical for the virus’ entry into host cells. Here we provide a systematic review of the available literature and an impetus for further research on the use of Gal-3 inhibitors in the treatment of COVID-19. Further, we propose a dual mechanism by which Gal-3 inhibition may be beneficial in the treatment of COVID-19, both suppressing the host inflammatory response and impeding viral attachment to host cells.
John L. Caniglia, Maheedhara R. Guda, Swapna Asuthkar, Andrew J. Tsung, Kiran K. Velpula