A new multivariable 6-psi-6 summation formula

By multidimensional matrix inversion, combined with an A_r extension of Jackson's 8-phi-7 summation formula by Milne, a new multivariable 8-phi-7 summation is derived. By a polynomial argument this 8-phi-7 summation is transformed to another multivariable 8-phi-7 summation which, by taking a suitable limit, is reduced to a new multivariable extension of the nonterminating 6-phi-5 summation. The latter is then extended, by analytic continuation, to a new multivariable extension of Bailey's very-well-poised 6-psi-6 summation formula.Comment: 16 page

Study on the corrosion behavior of polymeric nanocomposite coatings containing halloysite nanotubes loaded with multicomponent inhibitor

In the present study, the halloysite nanotubes (HNTs) were loaded with a multicomponent inhibitor (LHNT) comprising mainly benzotriazole (BTA), sodium benzoate (SB), and lauric acid (LA) via the vacuum cycling method. The successful loading of the BTA + LA + SB inhibitor has been confirmed by the TGA, FTIR, and BET analyses. The TGA analysis has determined ? 14% loading of the BTA + LA + SB into the HNTs. Moreover, UV-vis analysis shows that the time and pH-dependent have incremental release of the multicomponent inhibitor in various studied media. The composite coatings (LHNT COAT) were developed by reinforcing the 3 wt% of LHNTs into the epoxy matrix. The corrosion protection of the developed LHNT COAT was enhanced by 99.6% and 98.88% compared to the blank epoxy and unloaded HNT coatings, respectively. This improvement in the corrosion behavior can be attributed to the active release of the multicomponent inhibitor, as was also demonstrated by the electrochemical impedance spectroscopic (EIS) test. It is further predicted that the improved corrosion inhibition efficiency of LHNT COAT may be due to the formation of some components produced from the reaction of the inhibitor components or from the inhibitor reaction with the corrosive medium. The high corrosion resistance of LHNT COAT makes it attuned to several industrial applications.This publication was made possible by NPRP Grant 11S-1226-170132 and NPRP 13S-0120-200116 from the Qatar National Research Fund (a member of the Qatar Foundation). Statements made herein are solely the responsibility of the authors. The authors would like to thank the Central laboratory Unit (CLU), Qatar University, for SEM and TEM analyses.Scopu

Observation of Quantum Asymmetry in an Aharonov-Bohm Ring

We have investigated the Aharonov-Bohm effect in a one-dimensional GaAs/GaAlAs ring at low magnetic fields. The oscillatory magnetoconductance of these systems are for the first time systematically studied as a function of density. We observe phase-shifts of $\pi$ in the magnetoconductance oscillations, and halving of the fundamental $h/e$ period, as the density is varied. Theoretically we find agreement with the experiment, by introducing an asymmetry between the two arms of the ring.Comment: 4 pages RevTex including 3 figures, submitted to Phys. Rev.

Cosmic-ray strangelets in the Earth's atmosphere

If strange quark matter is stable in small lumps, we expect to find such lumps, called ``strangelets'', on Earth due to a steady flux in cosmic rays. Following recent astrophysical models, we predict the strangelet flux at the top of the atmosphere, and trace the strangelets' behavior in atmospheric chemistry and circulation. We show that several strangelet species may have large abundances in the atmosphere; that they should respond favorably to laboratory-scale preconcentration techniques; and that they present promising targets for mass spectroscopy experiments.Comment: 28 pages, 4 figures, revtex

Nonhermitean Random Matrix Models : a Free Random Variable Approach

Using the standard concepts of free random variables, we show that for a large class of nonhermitean random matrix models, the support of the eigenvalue distribution follows from their hermitean analogs using a conformal transformation. We also extend the concepts of free random variables to the class of nonhermitean matrices, and apply them to the models discussed by Ginibre-Girko (elliptic ensemble) and Mahaux-Weidenm\"uller (chaotic resonance scattering).Comment: 7 pages LaTeX, 1 EPS figur

Psychological distress during pandemic Covid-19 among adult general population: Result across 13 countries

The COVID-19 pandemics caused an unprecedented mortality, distress, and globally poses a challenge to mental resilience. To our knowledge, this is the first study that aimed to investigate the psychological distress among the adult general population across 13 countries. This cross-sectional study was conducted through online survey by recruiting 7091 respondents. Psychological distress was evaluated with COVID-19 Peritraumatic Distress Index (CPDI). The crude prevalence of psychological distress due to COVID-19 is highest in Vietnam, followed by Egypt, and Bangladesh. Through Multivariate Logistic Regression Analysis, the respondents from Vietnam holds the highest level of distress, while the respondents from Sri Lanka holds the lowest level of distress with reference to Nepal.Female respondents had higher odds of having reported psychological distress, and those with tertiary education were less likely to report psychological distress compared to those with lower level of education. The findings indicate that psychological distress is varies across different countries. Therefore, different countries should continue the surveillance on psychological consequences through the COVID-19 pandemic to monitor the burden and to prepare for the targeted mental health support interventions according to the need. The coping strategies and social support should be provided especially to the lower educational attainment group

Polyphasic taxonomy of Aspergillus section Candidi based on molecular, morphological and physiological data

Aspergillus section Candidi historically included a single white-spored species, A. candidus. Later studies clarified that other species may also belong to this section. In this study, we examined isolates of species tentatively assigned to section Candidi using a polyphasic approach. The characters examined include sequence analysis of partial β-tubulin, calmodulin and ITS sequences of the isolates, morphological and physiological tests, and examination of the extrolite profiles. Our data indicate that the revised section Candidi includes 4 species: A. candidus, A. campestris, A. taichungensis and A. tritici. This is strongly supported by all the morphological characteristics that are characteristic of section Candidi: slow growing colonies with globose conidial heads having white to yellowish conidia, conidiophores smooth, small conidiophores common, metulae present and covering the entire vesicle, some large Aspergillus heads with large metulae, presence of diminutive heads in all species, conidia smooth or nearly so with a subglobose to ovoid shape, and the presence of sclerotia in three species (A. candidus, A. taichungensis and A. tritici). Aspergillus tritici has been suggested to be the synonym of A. candidus previously, however, sequence data indicate that this is a valid species and includes isolates came from soil, wheat grain, flour and drums from India, Ghana, Sweden, The Netherlands and Hungary, making it a relatively widespread species. All species produce terphenyllins and candidusins and three species (A. candidus, A. campestris and A. tritici) produce chlorflavonins. Xanthoascins have only been found in A. candidus. Each of the species in section Candidi produce several other species specific extrolites, and none of these have been found in any other Aspergillus species. A. candidus has often been listed as a human pathogenic species, but this is unlikely as this species cannot grow at 37 °C. The pathogenic species may be A. tritici or white mutants of Aspergillus flavus

Team dynamics in emergency surgery teams: results from a first international survey

Background: Emergency surgery represents a unique context. Trauma teams are often multidisciplinary and need to operate under extreme stress and time constraints, sometimes with no awareness of the trauma\u2019s causes or the patient\u2019s personal and clinical information. In this perspective, the dynamics of how trauma teams function is fundamental to ensuring the best performance and outcomes. Methods: An online survey was conducted among the World Society of Emergency Surgery members in early 2021. 402 fully filled questionnaires on the topics of knowledge translation dynamics and tools, non-technical skills, and difficulties in teamwork were collected. Data were analyzed using the software R, and reported following the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). Results: Findings highlight how several surgeons are still unsure about the meaning and potential of knowledge translation and its mechanisms. Tools like training, clinical guidelines, and non-technical skills are recognized and used in clinical practice. Others, like patients\u2019 and stakeholders\u2019 engagement, are hardly implemented, despite their increasing importance in the modern healthcare scenario. Several difficulties in working as a team are described, including the lack of time, communication, training, trust, and ego. Discussion: Scientific societies should take the lead in offering training and support about the abovementioned topics. Dedicated educational initiatives, practical cases and experiences, workshops and symposia may allow mitigating the difficulties highlighted by the survey\u2019s participants, boosting the performance of emergency teams. Additional investigation of the survey results and its characteristics may lead to more further specific suggestions and potential solutions

Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume

The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimer’s Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-β PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-β positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimer’s disease-related phenotypes, including measures of cognition or brain Amyloid-β burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes