scholarly journals Correlates of non-random patterns of capsule switching in pneumococcus

2019 ◽  
Author(s):  
Shreyas S. Joshi ◽  
M. A. Al-Mamun ◽  
Daniel M. Weinberger

ABSTRACTBackgroundPneumococcus is a diverse pathogen, with >90 serotypes, each of which has a distinct polysaccharide capsule. Pneumococci can switch capsules, evading vaccine pressure. Certain serotype pairs are more likely to switch, but the drivers of these patterns are not well understood.MethodsWe used the PubMLST and Global Pneumococcal Sequencing (GPS) databases to quantify the number of genetic lineages on which different serotype pairs co-occur. We also quantified the genetic diversity of each serotype. Regression models evaluated the relationship between shared polysaccharide structural components and the frequency of serotype switching and diversity.ResultsA number of serotype pairs co-occurred on the same genetic lineage more commonly than expected. Co-occurrence of between-serogroup pairs was more common when both serotypes had glucose as a component of the capsule (and, potentially, glucuronic acid). Diversity also varied markedly by serotype and was lower for serotypes with glucuronic acid in the capsule and higher for those with galactose in the capsule.ConclusionsCertain pairs of serotypes are more likely to occur on the same genetic background, and these patterns were correlated with shared polysaccharide components. This might indicate adaptation of strains to produce capsules with particular characteristics.

2019 ◽  
Vol 221 (10) ◽  
pp. 1669-1676
Author(s):  
Shreyas S Joshi ◽  
Mohammad A Al-Mamun ◽  
Daniel M Weinberger

Abstract Background Pneumococcus is a diverse pathogen, with >90 serotypes, each of which has a distinct polysaccharide capsule. Pneumococci can switch capsules, evading vaccine pressure. Certain serotype pairs are more likely to occur on the same genetic background as a results of serotype switching, but the drivers of these patterns are not well understood. Methods We used the PubMLST and Global Pneumococcal Sequencing Project databases to quantify the number of genetic lineages on which different serotype pairs occur together. We also quantified the genetic diversity of each serotype. Regression model were used to evaluate the relationship between shared polysaccharide components and the frequency of serotype co-occurrence and diversity. Results A number of serotype pairs occurred together on the same genetic lineage more commonly than expected. Co-occurrence of between-serogroup pairs was more common when both serotypes had glucose as a component of the capsule (and, potentially, glucuronic acid, any-N-acetylated sugar, or ribitol). Diversity also varied markedly by serotype and was associated with the presence of specific sugars in the capsule. Conclusions Certain pairs of serotypes are more likely to co-occur on the same genetic background. These patterns were correlated with shared polysaccharide components. This might reflect adaptation of strains to produce capsules with specific characteristics.


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 423 ◽  
Author(s):  
Rima D. Lucardi ◽  
Lisa E. Wallace ◽  
Gary N. Ervin

The spatial expansions of invasive organisms in the novel range are generally expected to follow an isolation-by-distance relationship (IBD) if the invasion is biologically driven; however, many invasions are facilitated anthropogenically. This research focused on the extant expansion patterns of cogongrass (Imperata cylindrica). Cogongrass is a widespread invasive species throughout the southern United States (US). Patterns of infestation vary among US states. Cogongrass is pyrogenic, and its invasion threatens softwood (Pinus spp.) plantations, a substantial economic market for this US region. Over 600 individuals were sampled from seven invaded US states, using amplified fragment length polymorphisms (AFLPs) to assess genetic diversity and population structure. We suspected that differences in historical management efforts among US states influenced differences in genetic diversity and structure. We detected two genetic lineages at the highest level of analysis. One genetic lineage was locally restricted, whereas the other was found throughout the study region. Admixed individuals were found in all US states and consistently co-occurred with the dominant lineage, suggesting that secondary contact and hybridization may have facilitated expansion. The widespread prevalence of only one of the two detected genetic lineages suggests a primary genetic lineage responsible for on-going population expansion in the US.


1986 ◽  
Vol 51 (10) ◽  
pp. 2250-2258 ◽  
Author(s):  
Rudolf Kohn ◽  
Zdena Hromádková ◽  
Anna Ebringerová

Several fractions of acid hemicelluloses isolated from rye bran were characterized by molar ratios of saccharides (D-Xyl, L-Ara, D-Glc, D-Gal) and 4-O-methyl-D-glucuronic acid and protein content. Binding of Pb2+ and Cu2+ ions to these acid polysaccharides was considered according to function (M)b = f([M2+]f), expressing the relationship between the amount of metal (M)b bound to 1 g of the substance and the concentration of free ions [M2+]f in the equilibrium solution and according to the association degree β of these cations with carboxyl groups of uronic acid at a stoichiometric ratio of both components in the system under investigation. Acid hemicelluloses contained only a very small portion of uronic acid ((COOH) 0.05-0.18 mmol g-1); the model polysaccharide, 4-O-methyl-D-glucurono-D-xylan of beech, was substantially richer in uronic acid content ((COOH) 0.73 mmol g-1). Consequently, the amount of lead and copper bound to acid hemicelluloses is very small ((M)b 0.017-0.025 mmol g-1) at [M2+]f = 0.10 mmol l-1. On the other hand, much greater amount of cations ((M)f 0.09-0.10 mmol g-1) was bound to the glucuronoxylan. The association degree β was like with the majority of samples (β = 0.31-0.38). The amount of lead and copper(II) bound to acid hemicelluloses from rye bran is several times lower than that bound to dietary fiber isolated from vegetables (cabbage, carrot), rich in pectic substances.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A305-A306
Author(s):  
Jesse Moore ◽  
Ellita Williams ◽  
Collin Popp ◽  
Anthony Briggs ◽  
Judite Blanc ◽  
...  

Abstract Introduction Literature shows that exercise moderates the relationship between sleep and emotional distress (ED.) However, it is unclear whether different types of exercise, such as aerobic and strengthening, affect this relationship differently. We investigated the moderating role of two types of exercise (aerobic and strengthening) regarding the relationship between ED and sleep. Methods Our analysis was based on data from 2018 National Health Interview Survey (NHIS), a nationally representative study in which 2,814 participants provided all data. Participants were asked 1) “how many days they woke up feeling rested over the past week”, 2) the Kessler 6 scale to determine ED (a score >13 indicates ED), and 3) the average frequency of strengthening or aerobic exercise per week. Logistic regression analyses were performed to determine if the reported days of waking up rested predicted level of ED. We then investigated whether strengthening or aerobic exercise differentially moderated this relationship. Covariates such as age and sex were adjusted in the logistic regression models. Logistic regression analyses were performed to determine if subjective reporting of restful sleep predicted level of ED. We investigated whether strengthening exercise or aerobic exercise differentially moderated this relationship. Covariates such as age and sex were adjusted in the logistic regression models. Results On average, participants reported 4.41 restful nights of sleep (SD =2.41), 3.43 strengthening activities (SD = 3.19,) and 8.47 aerobic activities a week (SD=5.91.) We found a significant association between days over the past week reporting waking up feeling rested and ED outcome according to K6, Χ2(1) = -741, p= <.001. The odds ratio signified a decrease of 52% in ED scores for each unit of restful sleep (OR = .48, (95% CI = .33, .65) p=<.001.) In the logistic regression model with moderation, aerobic exercise had a significant moderation effect, Χ2(1) = .03, p=.04, but strengthening exercise did not. Conclusion We found that restful sleep predicted reduction in ED scores. Aerobic exercise moderated this relationship, while strengthening exercise did not. Further research should investigate the longitudinal effects of exercise type on the relationship between restful sleep and ED. Support (if any) NIH (K07AG052685, R01MD007716, K01HL135452, R01HL152453)


Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 37
Author(s):  
Tomás de Figueiredo ◽  
Ana Caroline Royer ◽  
Felícia Fonseca ◽  
Fabiana Costa de Araújo Schütz ◽  
Zulimar Hernández

The European Space Agency Climate Change Initiative Soil Moisture (ESA CCI SM) product provides soil moisture estimates from radar satellite data with a daily temporal resolution. Despite validation exercises with ground data that have been performed since the product’s launch, SM has not yet been consistently related to soil water storage, which is a key step for its application for prediction purposes. This study aimed to analyse the relationship between soil water storage (S), which was obtained from soil water balance computations with ground meteorological data, and soil moisture, which was obtained from radar data, as affected by soil water storage capacity (Smax). As a case study, a 14-year monthly series of soil water storage, produced via soil water balance computations using ground meteorological data from northeast Portugal and Smax from 25 mm to 150 mm, were matched with the corresponding monthly averaged SM product. Linear (I) and logistic (II) regression models relating S with SM were compared. Model performance (r2 in the 0.8–0.9 range) varied non-monotonically with Smax, with it being the highest at an Smax of 50 mm. The logistic model (II) performed better than the linear model (I) in the lower range of Smax. Improvements in model performance obtained with segregation of the data series in two subsets, representing soil water recharge and depletion phases throughout the year, outlined the hysteresis in the relationship between S and SM.


2021 ◽  
Vol 13 (14) ◽  
pp. 7697
Author(s):  
Sung Yul Ryoo ◽  
Sang Cheol Park

Shadow work continues to witness a significant uptick in the context of mobile shopping. Therefore, we question whether shadow work perceived by mobile shoppers may become a bigger problem, create fatigue for mobile shoppers, and lead them to discontinue the use of mobile shopping apps. This study examines the relationship between shadow work and the discontinuance of mobile shopping apps. Data from a total of 266 completed surveys were collected by a market research firm. We adopted partial least squares structural equation modeling (PLS-SEM) to assess both the measurement and structural components of the model. The results show that both information overload and system feature overload positively influence individuals’ shadow work. This study explores the concept of shadow work in the context of mobile shopping apps. Specifically, the study developed the relationships between the antecedents and consequences of shadow work in the mobile shopping context. The main contribution of our study is that it introduces an integrative model of shadow work in the mobile shopping context, highlighting the importance of shadow work.


Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3415
Author(s):  
Hursuong Vongsachang ◽  
Aleksandra Mihailovic ◽  
Jian-Yu E ◽  
David S. Friedman ◽  
Sheila K. West ◽  
...  

Understanding periods of the year associated with higher risk for falling and less physical activity may guide fall prevention and activity promotion for older adults. We examined the relationship between weather and seasons on falls and physical activity in a three-year cohort of older adults with glaucoma. Participants recorded falls information via monthly calendars and participated in four one-week accelerometer trials (baseline and per study year). Across 240 participants, there were 406 falls recorded over 7569 person-months, of which 163 were injurious (40%). In separate multivariable regression models incorporating generalized estimating equations, temperature, precipitation, and seasons were not significantly associated with the odds of falling, average daily steps, or average daily active minutes. However, every 10 °C increase in average daily temperature was associated with 24% higher odds of a fall being injurious, as opposed to non-injurious (p = 0.04). The odds of an injurious fall occurring outdoors, as opposed to indoors, were greater with higher average temperatures (OR per 10 °C = 1.46, p = 0.03) and with the summer season (OR = 2.69 vs. winter, p = 0.03). Falls and physical activity should be understood as year-round issues for older adults, although the likelihood of injury and the location of fall-related injuries may change with warmer season and temperatures.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 302
Author(s):  
Malik Sallam ◽  
Azmi Mahafzah

The rapid evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is manifested by the emergence of an ever-growing pool of genetic lineages. The aim of this study was to analyze the genetic variability of SARS-CoV-2 in Jordan, with a special focus on the UK variant of concern. A total of 579 SARS-CoV-2 sequences collected in Jordan were subjected to maximum likelihood and Bayesian phylogenetic analysis. Genetic lineage assignment was undertaken using the Pango system. Amino acid substitutions were investigated using the Protein Variation Effect Analyzer (PROVEAN) tool. A total of 19 different SARS-CoV-2 genetic lineages were detected, with the most frequent being the first Jordan lineage (B.1.1.312), first detected in August 2020 (n = 424, 73.2%). This was followed by the second Jordan lineage (B.1.36.10), first detected in September 2020 (n = 62, 10.7%), and the UK variant of concern (B.1.1.7; n = 36, 6.2%). In the spike gene region, the molecular signature for B.1.1.312 was the non-synonymous mutation A24432T resulting in a deleterious amino acid substitution (Q957L), while the molecular signature for B.1.36.10 was the synonymous mutation C22444T. Bayesian analysis revealed that the UK variant of concern (B.1.1.7) was introduced into Jordan in late November 2020 (mean estimate); four weeks earlier than its official reporting in the country. In Jordan, an exponential increase in COVID-19 cases due to B.1.1.7 lineage coincided with the new year 2021. The highest proportion of phylogenetic clustering was detected for the B.1.1.7 lineage. The amino acid substitution D614G in the spike glycoprotein was exclusively present in the country from July 2020 onwards. Two Jordanian lineages dominated infections in the country, with continuous introduction/emergence of new lineages. In Jordan, the rapid spread of the UK variant of concern should be monitored closely. The spread of SARS-CoV-2 mutants appeared to be related to the founder effect; nevertheless, the biological impact of certain mutations should be further investigated.


2021 ◽  
Vol 7 (1) ◽  
pp. 205630512098445
Author(s):  
Nora Kirkizh ◽  
Olessia Koltsova

Availability of alternative information through social media, in particular, and digital media, in general, is often said to induce social discontent, especially in states where traditional media are under government control. But does this relation really exist, and is it generalizable? This article explores the relationship between self-reported online news consumption and protest participation across 48 nations in 2010–2014. Based on multilevel regression models and simulations, the analysis provides evidence that those respondents who reported that they had attended a protest at least once read news online daily or weekly. The study also shows that the magnitude of the effect varies depending on the political context: surprisingly, despite supposedly unlimited control of offline and online media, autocratic countries demonstrated higher effects of online news than transitional regimes, where the Internet media are relatively uninhibited.


i-com ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 139-151
Author(s):  
Thomas Schmidt ◽  
Miriam Schlindwein ◽  
Katharina Lichtner ◽  
Christian Wolff

AbstractDue to progress in affective computing, various forms of general purpose sentiment/emotion recognition software have become available. However, the application of such tools in usability engineering (UE) for measuring the emotional state of participants is rarely employed. We investigate if the application of sentiment/emotion recognition software is beneficial for gathering objective and intuitive data that can predict usability similar to traditional usability metrics. We present the results of a UE project examining this question for the three modalities text, speech and face. We perform a large scale usability test (N = 125) with a counterbalanced within-subject design with two websites of varying usability. We have identified a weak but significant correlation between text-based sentiment analysis on the text acquired via thinking aloud and SUS scores as well as a weak positive correlation between the proportion of neutrality in users’ voice and SUS scores. However, for the majority of the output of emotion recognition software, we could not find any significant results. Emotion metrics could not be used to successfully differentiate between two websites of varying usability. Regression models, either unimodal or multimodal could not predict usability metrics. We discuss reasons for these results and how to continue research with more sophisticated methods.


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