Chaos, Percolation and the Coronavirus Spread

The dynamics of the spreading of the COVID-19 virus has similar features to turbulent flow, chaotic maps, and other non-linear systems: a small seed grows exponentially and eventually saturates. Like in the percolation model, the virus is most dangerous if the probability of transmission (or the bond probability p in the percolation model) is high. This suggests a relation with the population density, ρs, which must be higher than a certain value (ρs > 1,000 persons/km2). A "seed' implanted in such populations grows vigorously and affects nearby places at distance x. Thus, the spreading is governed by the ratio ρ = ρs/x. Assuming a power law dependence τ of the number of positives to the virus N+ from ρ, we find τ = 0.55, 0.75, and 0.96 for South Korea, Italy, and China, respectively

A Generalization of Uniformly Extremely Convex Banach Spaces

We discuss a new class of Banach spaces which are the generalization of uniformly extremely convex spaces introduced by Wulede and Ha. We prove that the new class of Banach spaces lies strictly between either the classes of -uniformly rotund spaces and -strongly convex spaces or classes of fully -convex spaces and -strongly convex spaces and has no inclusive relation with the class of locally -uniformly convex spaces. We obtain in addition some characterizations and properties of this new class of Banach spaces. In particular, our results contain the main results of Wulede and Ha

A rare novel mutation in TECTA causes autosomal dominant nonsyndromic hearing loss in a Mongolian family

BACKGROUND: The genetic basis of autosomal dominant nonsyndromic hearing loss is complex. Genetic factors are responsible for approximately 50% of cases with congenital hearing loss. However, no previous studies have documented the clinical phenotype and genetic basis of autosomal dominant nonsyndromic hearing loss in Mongolians. METHODS: In this study, we performed exon capture sequencing of a Mongolian family with hereditary hearing loss and identified a novel mutation in TECTA gene, which encodes α -tectorin, a major component of the inner ear extracellular matrix that contacts the specialized sensory hair cells. RESULTS: The novel G → T missense mutation at nucleotide 6016 results in a substitution of amino acid aspartate at 2006 with tyrosine (Asp2006Tyr) in a highly conserved zona pellucida (ZP) domain of α-tectorin. The mutation is not found in control subjects from the same family with normal hearing and a genotype-phenotype correlation is observed. CONCLUSION: A novel missense mutation c.6016 G > T (p.Asp2006Tyr) of TECTA gene is a characteristic TECTA-related mutation which causes autosomal dominant nonsyndromic hearing loss. Our result indicated that mutation in TECTA gene is responsible for the hearing loss in this Mongolian family

Genetic polymorphisms and related risk factors of ischemic stroke in a Mongolian population in China

Ischemic stroke is caused by an interruption in the flow of blood to the brain and a risk factor for death and disability. Recent genome-wide association studies have identified more than 40 common sequence variants associated with ischemic stroke. However, the results are not always the same in populations with different genetic backgrounds. In the present study, we evaluated a hypothesis that a North Asian population living in a geographic area with unusually harsh environmental conditions would develop unique genetic risks. We investigated the candidate genes for ischemic stroke and risk factors in a Chinese Mongolian population which has not been explored previously. A total of 167 stroke cases and 176 controls were included in the study. Genotyping was performed by amplicon sequencing. The association was detected with single nucleotide polymorphisms (SNPs) located within genes NINJ2 (rs12425791) and ALDH2 (rs2238151) as well as intergenic rs9536591 were significantly associated with ischemic stroke, of which SNP rs12425791 of the NINJ2 gene was the strongest association. ALDH2 gene encodes mitochondrial aldehyde dehydrogenase, involved in the oxidative pathway of alcohol metabolism. Sex, age, body mass index and high blood pressure might be the risk factors. The current work also demonstrated genetic heterogeneity exists between Chinese and other populations. Our study provided the new insights into the genetic basis and environmental factors of ischemic stroke in Mongolian population

Corrosion behaviour of new quaternary ZrNbTiAl alloys in simulated physiological solution using electrochemical techniques and surface analysis methods

The potential biomedical application of three new quaternary Zr alloys, namely Zr6Ti15Nb4Al, Zr32Ti15Nb4Al, and Zr49Ti15Nb4Al, was evaluated in vitro using electrochemical methods complemented with surface analysis of corrosion resistance. Cyclic potentiodynamic polarization (CCP) and electrochemical impedance spectroscopy (EIS) tests were performed in Ringer’s solution at 37 ºC. The electrochemical behavior of the ZrTiNbAl quaternary alloys was consistent with the formation of passivating oxide films on the surfaces of these materials. Localized breakdown of the oxide layer occurred on Zr6Ti15Nb4Al and Zr32Ti15Nb4Al alloys subjected to positive anodic polarization, a feature confirmed by scanning electron microscopy (SEM) on retrieved samples. The Zr49Ti15Nb4Al alloy, which had the highest titanium (49 wt.%) content, exhibited a larger passive range in the polarization curve and was immune to localized corrosion breakdown in a simulated physiological solution for the range of polarizations that can occur in the human bod

Some Characterizations of k-Strictly Convex and k-Smooth Banach Spaces

In this paper, some characterizations of k-strictly convex (k-smooth, respectively) spaces are given. As special cases for k=1, some characterizations of strictly convex (smooth, respectively) spaces are given