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Author(s):  
Adriano Bonforti ◽  
Ricard Sole

Multicellular life forms have evolved many times in our planet, suggesting that this is a common evolutionary innovation. Multiple advantages have been proposed for multicellularity (MC) to emerge. In this paper we address the problem of how the first precondition for multicellularity, namely "stay together" might have occurred under spatially limited resources exploited by a population of unicellular agents. Using a minimal model of evolved cell-cell adhesion among growing and dividing cells that exploit a localised resource with a given size, we show that a transition occurs at a critical resource size separating a phase of evolved multicellular aggregates from a phase where unicellularity (UC) is favoured. The two phases are separated by an intermediate domain where where both UC and MC can be selected by evolution. This model provides a minimal approach to the early stages that were required to transition from Darwinian individuality to cohesive groups of cells associated with a physical cooperative effect: when resources are present only in a localised portion of the habitat, MC is a desirable property as it helps cells to keep close to the available local nutrients.


Significance On the contrary, since May, when the anti-junta National Unity Government (NUG) formed a military wing, fighting has spread nationwide. The most critical arena in the conflict is online space: both sides have effectively weaponised mobile technology and the internet. Impacts Internet shutdowns will impede COVID-19 public health programmes, risking further transmission of infection across borders. International human rights groups will not call for sanctions against tech companies because that would further hinder the opposition. Chinese surveillance technology will be a critical resource for the junta.


2021 ◽  
Vol 15 (12) ◽  
pp. e0010063
Author(s):  
Nicole A. P. Lieberman ◽  
Michelle J. Lin ◽  
Hong Xie ◽  
Lasata Shrestha ◽  
Tien Nguyen ◽  
...  

In spite of its immutable susceptibility to penicillin, Treponema pallidum (T. pallidum) subsp. pallidum continues to cause millions of cases of syphilis each year worldwide, resulting in significant morbidity and mortality and underscoring the urgency of developing an effective vaccine to curtail the spread of the infection. Several technical challenges, including absence of an in vitro culture system until very recently, have hampered efforts to catalog the diversity of strains collected worldwide. Here, we provide near-complete genomes from 196 T. pallidum strains–including 191 T. pallidum subsp. pallidum–sequenced directly from patient samples collected from 8 countries and 6 continents. Maximum likelihood phylogeny revealed that samples from most sites were predominantly SS14 clade. However, 99% (84/85) of the samples from Madagascar formed two of the five distinct Nichols subclades. Although recombination was uncommon in the evolution of modern circulating strains, we found multiple putative recombination events between T. pallidum subsp. pallidum and subsp. endemicum, shaping the genomes of several subclades. Temporal analysis dated the most recent common ancestor of Nichols and SS14 clades to 1717 (95% HPD: 1543–1869), in agreement with other recent studies. Rates of SNP accumulation varied significantly among subclades, particularly among different Nichols subclades, and was associated in the Nichols A subclade with a C394F substitution in TP0380, a ERCC3-like DNA repair helicase. Our data highlight the role played by variation in genes encoding putative surface-exposed outer membrane proteins in defining separate lineages, and provide a critical resource for the design of broadly protective syphilis vaccines targeting surface antigens.


2021 ◽  
Vol 2021 (12) ◽  
pp. 123302
Author(s):  
Ariane Soret ◽  
Ohad Shpielberg ◽  
Eric Akkermans

Abstract Thermodynamic uncertainty relations unveil useful connections between fluctuations in thermal systems and entropy production. This work extends these ideas to the disparate field of zero temperature quantum mesoscopic physics where fluctuations are due to coherent effects and entropy production is replaced by a cost function. The cost function arises naturally as a bound on fluctuations, induced by coherent effects—a critical resource in quantum mesoscopic physics. Identifying the cost function as an important quantity demonstrates the potential of importing powerful methods from non-equilibrium statistical physics to quantum mesoscopics.


Author(s):  
Na Geng ◽  
Xiaolan Xie

This paper is devoted to the management of advance admission requests for obstetric care. Pregnant women in China select one hospital and request admission for both antenatal and postnatal care after nine weeks of pregnancy. Schedulers must make the admission decision instantly based on the availability of the most critical resource, that is, hospital beds for postnatal care. The random delay between admission requests and postnatal care has created a distinct advance admission control problem. To address this issue, we propose a basic model that assumes a unit bed requirement for one day. Each admission generates a unit of revenue and each unit of overcapacity use incurs an overcapacity cost. With the objective of maximizing the expected net revenue, we establish an optimal policy for unlimited requests, that is, an expected arrival time quota (EATQ) policy that accepts a fixed quota of advance admission requests with the same expected date of confinement. We then propose an extended model for general capacity requirements. Using the Poisson approximation, we establish the optimality of the EATQ policy, which is shown to be solvable by a simple linear programming model. We compare the numerical results from the different policies and conduct a sensitivity analysis. The EATQ policy is demonstrated to be the best option in all test instances and notably outperforms the current admission rules used in hospitals, which usually accept admission requests according to some empirical monthly quota of the expected delivery month. The Poisson approximation is shown to be effective for determining the optimal EATQ policy for both stationary and nonstationary arrivals. Summary of Contribution: First, this paper investigates the advance admission control problem for obstetric care. Pregnant women in China choose one hospital and request admission for both antenatal and postnatal care after nine weeks of pregnancy but the most critical resource is hospitalization beds needed for postnatal care. The random delay between admission request and postnatal care makes the problem unique and challenging to solve. It belongs to the scope of computing and operations research. Second, this paper formulates a dynamic programming model, analyzes the structural properties of the optimal control policy, and finally proposes a mathematical programming model to determine the optimal quota. Numerical experiments show the validity of the proposed approach. It covers the research contents of theories on dynamic stochastic control, mathematic programming model, and experiments. Moreover, this paper is motivated by the practical problem (advance admission control) in obstetric units of Shanghai. Using these optimality properties, solution approaches, and numerical results, this paper provides guidance on how to manage advance obstetric admission requests.


2021 ◽  
Vol 3 (Supplement_5) ◽  
pp. v144-v156
Author(s):  
Lauritz Miarka ◽  
Manuel Valiente

Abstract Modeling of metastatic disease in animal models is a critical resource to study the complexity of this multi-step process in a relevant system. Available models of metastatic disease to the brain are still far from ideal but they allow to address specific aspects of the biology or mimic clinically relevant scenarios. We not only review experimental models and their potential improvements but also discuss specific answers that could be obtained from them on unsolved aspects of clinical management.


Author(s):  
Meghan Towne ◽  
Mari Rossi ◽  
Bess Wayburn ◽  
Jennifer Huang ◽  
Kelly Radtke ◽  
...  

Clinical and research laboratories extensively use exome sequencing due to its high diagnostic rates, cost savings, impact on clinical management, and efficacy for disease gene discovery. While the rates of disease gene discovery have steadily increased, only ~16% of genes in the genome have confirmed disease associations. Here we describe our diagnostic laboratory’s disease gene discovery and ongoing data-sharing efforts with GeneMatcher. In total, we submitted 246 candidates from 243 unique genes to GeneMatcher, of which 45.93% are now clinically characterized. Submissions with at least one case meeting our candidate genes reporting criteria were significantly more likely to be characterized as of October 2021 compared to genes with no candidates meeting our reporting criteria (p=0.025). We reported relevant findings related to these gene-disease associations for 480 probands. In 219 (45.63%) instances, these results were reclassifications after an initial candidate gene (uncertain) or negative report. Since 2013, we have co-authored 105 publications focused on delineating gene-disease associations. Diagnostic laboratories are pivotal for disease gene discovery efforts and can screen phenotypes based on genotype matches, contact clinicians of relevant cases, and issue proactive reclassification reports. GeneMatcher is a critical resource in these efforts.


2021 ◽  
Vol 73 ◽  
pp. 102171
Author(s):  
Mária Hámor-Vidó ◽  
Tamás Hámor ◽  
Lili Czirok

2021 ◽  
Vol 73 ◽  
pp. 102177
Author(s):  
Xu Tian ◽  
Yong Geng ◽  
Joseph Sarkis ◽  
Cuixia Gao ◽  
Xin Sun ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1081
Author(s):  
Daria Zaccaria ◽  
Noemi Vicentini ◽  
Maria Grazia Perna ◽  
Gianluigi Rosatelli ◽  
Victor V. Sharygin ◽  
...  

Discrete zircons, up to 9 mm in length, occur in alluvial deposits from the Veneto area. They are likely derived from the disaggregation of lamprophyric rocks belonging to a regional, pervasive dyke-swarm. Zircon and REE phases occur in both alkaline lamprophyres and connate calcite-bearing felsic lithics and their debris in lamprophyre breccia. We present 36 new complete U–Pb and trace element analyses of zircons and associated inclusions. We used a statistical approach on a larger dataset using new and literature data to evaluate the confidence figure to give an estimation of age of zircons. Inclusions suggest a genetic link with an S–CO2–ZrO–BaO–SrO–CaO-rich fluid/melt possibly associated with carbonate-rich alkaline parental magma and a metasomatised mantle source. This paper confirms the importance of calcite–syenite and lamprophyre genetic link and zircon magmatic origin, in contrast with hydrothermal and metamorphic zircons. U–Pb dating by LA-ICP-MS provides time constrains (40.5–48.4 Ma, Lutetian), consistent with the age of the alkaline magmatic event. Trace element data indicate a link to anorogenic magmatism associated with mantle upwelling. Complex zoning is highlighted by cathodoluminescence images. The Veneto zircons are helpful for regional geological information and may have commercial potential as a critical resource for green technologies.


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