Infectivity Enhances Prediction of Viral Cascades in Twitter

Models of contagion dynamics, originally developed for infectious diseases, have proven relevant to the study of information, news, and political opinions in online social systems. Modelling diffusion processes and predicting viral information cascades are important problems in network science. Yet, many studies of information cascades neglect the variation in infectivity across different pieces of information. Here, we employ early-time observations of online cascades to estimate the infectivity of distinct pieces of information. Using simulations and data from real-world Twitter retweets, we demonstrate that these estimated infectivities can be used to improve predictions about the virality of an information cascade. Developing our simulations to mimic the real-world data, we consider the effect of the limited effective time for transmission of a cascade and demonstrate that a simple model for slow but non-negligible decay of the infectivity captures the essential properties of retweet distributions. These results demonstrate the interplay between the intrinsic infectivity of a tweet and the complex network environment within which it diffuses, strongly influencing the likelihood of becoming a viral cascade.Comment: 16 pages, 10 figure

Expertise diversity of teams predicts originality and long-term impact in science and technology

Despite the growing importance of teams in producing innovative and high-impact science and technology, it remains unclear how expertise diversity among team members relates to the originality and impact of the work they produce. Here, we develop a new method to quantify the expertise distance of researchers based on their prior career histories and apply it to 23 million scientific publications and 4 million patents. We find that across science and technology, expertise-diverse teams tend to produce work with greater originality. Teams with more diverse expertise have no significant impact advantage in the short- (2 years) or mid-term (5 years). Instead, they exhibit substantially higher long-term impact (10 years), increasingly attracting larger cross-disciplinary influence. This impact premium of expertise diversity among team members becomes especially pronounced when other dimensions of team diversity are missing, as teams within the same institution or country appear to disproportionately reap the benefits of expertise diversity. While gender-diverse teams have relatively higher impact on average, teams with varied levels of gender diversity all seem to benefit from increased expertise diversity. Given the growing knowledge demands on individual researchers, implementation of incentives for original research, and the tradeoffs between short-term and long-term impacts, these results may have implications for funding, assembling, and retaining teams with originality and long-lasting impacts.Comment: 31 pages, 5 figure

A case report on ATP6V0A4 gene mutation: Forecast of familial deafness by genetic investigation in a patient with autosomal recessive distal renal tubular acidosis

The autosomal recessive form of distal renal tubular acidosis (dRTA), a condition associated with the systemic accumulation of acid owing to its reduced elimination through kidneys, is caused by ATP6V0A4 mutation, which is typically related to either late-onset sensorineural hearing loss (SNHL) or normal hearing. This article reports dRTA in seven year old boy, born to a Chinese couple who have family history of deafness. The patient does not have hearing impairment. ATP6V0A4 gene sequencing demonstrated that there were 2 heterozygous mutations, c.1376C>T and c.1029+5G>A, in gene ATP6V0A4. c.1376C > T (p.Ser459Phe) is a kind of missense mutation in gene ATP6V0A4. c.1029+5G>A is a kind of intragenic mutation near the cutting area of gene ATP6V0A4. ATP6V0A4 gene mutation study substantiated the autosomal recessive dRTA without hearing impairment in the patient. This case report emphasizes the significance of early diagnosis and genetic screening of recessive forms of dRTA independent of hearing status and offer suitable intervention to treat dRTA as well as diminish the influence of SNHL on the child’s learning and communication in daily life.Keywords: Renal tubular acidosis, Homeostasis, Electrolytes, Hearing impairment, ATP6V0A4 gene, Mutatio

A theoretical study of the mechanism of the addition reaction between carbene and azacyclopropane

The mechanism of the addition reaction between carbene and azacyclopropane was investigated using the second-order Moller–Plesset perturbation theory (MP2). By using the 6-311+G* basis set, geometry optimization, vibrational analysis and the energy properties of the involved stationary points on the potential energy surface were calculated. From the surface energy profile, it can be predicted that there are two reaction mechanisms. The first one (1) is carbene attack at the N atom of azacyclopropane to form an intermediate, 1a (IM1a), which is a barrier-free exothermic reaction. Then, IM1a can isomerize to IM1b via a transition state 1a (TS1a), in which the potential barrier is 30.0 kJ/mol. Subsequently, IM1b isomerizes to a product (Pro1) via TS1b with a potential barrier of 39.3 kJ/mol. The other one (2) is carbene attack at the C atom of azacyclopropane, firstly to form IM2 via TS2a, the potential barrier is 35.4 kJ/mol. Then IM2 isomerizes to a product (Pro2) via TS2b with a potential barrier of 35.1 kJ/mol. Correspondingly, the reaction energy for the reactions (1) and (2) is –478.3 and –509.9 kJ/mol, respectively. Additionally, the orbital interactions are also discussed for the leading intermediate