statistical association
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2022 ◽  
Vol 4 (1) ◽  
Author(s):  
Kalins Banerjee ◽  
Jun Chen ◽  
Xiang Zhan

ABSTRACT The important role of human microbiome is being increasingly recognized in health and disease conditions. Since microbiome data is typically high dimensional, one popular mode of statistical association analysis for microbiome data is to pool individual microbial features into a group, and then conduct group-based multivariate association analysis. A corresponding challenge within this approach is to achieve adequate power to detect an association signal between a group of microbial features and the outcome of interest across a wide range of scenarios. Recognizing some existing methods’ susceptibility to the adverse effects of noise accumulation, we introduce the Adaptive Microbiome Association Test (AMAT), a novel and powerful tool for multivariate microbiome association analysis, which unifies both blessings of feature selection in high-dimensional inference and robustness of adaptive statistical association testing. AMAT first alleviates the burden of noise accumulation via distance correlation learning, and then conducts a data-adaptive association test under the flexible generalized linear model framework. Extensive simulation studies and real data applications demonstrate that AMAT is highly robust and often more powerful than several existing methods, while preserving the correct type I error rate. A free implementation of AMAT in R computing environment is available at https://github.com/kzb193/AMAT.


Author(s):  
Balogun Islamiat D ◽  
Inabo Helen I ◽  
Ella Elijah E

The efficacy of current or any intended antimalarial can only be resolute by cultivation and susceptibility studies. The aim of this research was to cultivate Plasmodium falciparum in vitro and comparing the antiplasmodial effects of standard antimalarial medications including herbaceous preparation. Asymptomatic pupils attending some schools in Zaria, Kaduna state, Nigeria were recruited into this research and blood samples were collected from them. Microscopy was done after thin and thick blood films were prepared and stained. The antiplasmodial activities of antimalarial drugs as well as herbal preparation were determined after the successful culturing of red blood cells in the Jatropha curcas medium.The phytochemical constituents of the herbs that made up the concoction were determined. The incidence of asymptomatic Plasmodium infection amongst school kids was 17.5%. There was no statistical association of location, gender and age with the obtained prevalence. Presence of alkaloids was observed in every plant screened while the same was also observed for tannins except in Enantia chloranta.Steroids and phlobatanins were observed in Citrus aurantifolia while there was presence of saponins in all the plant extracts except Cymbopogbon citratus. All the plants except Enantia chloranta contained flavonoids. There was presence of terpenoids in all screened plants except Azadirachta indica and Cymbopogbon citratus while cardiac glycosides were found in every plant except Magnifera indica and Enantia chloranta. Results obtained from the in vitro cultivation of the Plasmodium falciparum with Athemether/lumefanthrine, amodiaquine and herbal concoction showed average percentage parasite inhibition of 80%, 37.8% and 38.6% respectively. This implies that Arthemether/lumefanthrine was capable of inhibiting the growth of the parasite best. The herbal concoction also inhibited growth (38.6% inhibition). There is need for additional investigation on a wider variety of plants to explore their antiplasmodial activities since there is evidence that it works, and it is quite available and affordable.


Author(s):  
Christopher F. Baum ◽  
Jesús Otero

We present a new command, radf, that tests for explosive behavior in time series. The command computes the right-tail augmented Dickey and Fuller (1979, Journal of the American Statistical Association 74: 427–431) unitroot test and its further developments based on supremum statistics derived from augmented Dickey–Fuller-type regressions estimated using recursive windows (Phillips, Wu, and Yu, 2011, International Economic Review 52: 201–226) and recursive flexible windows (Phillips, Shi, and Yu, 2015, International Economic Review 56: 1043–1078). It allows for the lag length in the test regression and the width of rolling windows to be either specified by the user or determined using data-dependent procedures, and it performs the date-stamping procedures advocated by Phillips, Wu, and Yu (2011) and Phillips, Shi, and Yu (2015) to identify episodes of explosive behavior. It also implements the wild bootstrap proposed by Phillips and Shi (2020, Handbook of Statistics: Financial, Macro and Micro Econometrics Using R, Vol. 42, 61–80) to lessen the potential effects of unconditional heteroskedasticity and account for the multiplicity issue in recursive testing. The use of radf is illustrated with an empirical example.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Marianne Kaiser ◽  
Jan Dahl ◽  
Stine Jacobsen ◽  
Magdalena Jacobson ◽  
Pia Haubro Andersen ◽  
...  

Abstract Background Postpartum dysgalactia syndrome (PDS) is associated with a significantly higher activation of the inflammatory and stress response at parturition than in the healthy sow. Therefore, reliable and possibly non-invasive biomarkers for substantial increases of inflammation are searched to support the PDS diagnosis. This report studies the possible changes of the inflammatory marker enzyme adenosine deaminase (ADA) in serum and saliva of 38 PDS positive sows (PDS+) and 38 healthy sows (PDS-). Sampling was performed every 24 h from 60 h before to 36 h after parturition. Isoenzyme 1 (ADA1) and isoenzyme 2 (ADA2), as well as total ADA (tADA), were measured and their statistical association with several serum and saliva biomarkers of inflammation and stress was investigated. Results Compared to a baseline (60 to 36h prepartum), salivary activities of ADA1, ADA2 and tADA increased significantly over time in both PDS+ and PDS- sows, reaching their peaks after parturition. In serum from PDS- sows, no changes were observed over time in either ADA1, ADA2 or tADA. In PDS+ sows, serum ADA2 activity decreased temporarily after parturition followed by a significant increase compared to baseline. ADA1, ADA2 and tADA were all significantly associated with several inflammatory biomarkers and ADA1 in serum was associated with serum cortisol. Although serum activity was higher in PDS+ than in PDS- sows, the differences were not statistically significant. Further, no difference was noted between the groups in the analyses of saliva. Conclusions Salivary ADA1 and ADA2 increased in all sows after parturition, potentially as a response to the postpartum inflammation. However, no difference in the activity of ADA1, ADA2 and tADA were found between PDS+ and PDS- sows indicating inability to diagnose PDS under the conditions described in this report.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lingfei Wang

AbstractSingle-cell RNA sequencing (scRNA-seq) provides unprecedented technical and statistical potential to study gene regulation but is subject to technical variations and sparsity. Furthermore, statistical association testing remains difficult for scRNA-seq. Here we present Normalisr, a normalization and statistical association testing framework that unifies single-cell differential expression, co-expression, and CRISPR screen analyses with linear models. By systematically detecting and removing nonlinear confounders arising from library size at mean and variance levels, Normalisr achieves high sensitivity, specificity, speed, and generalizability across multiple scRNA-seq protocols and experimental conditions with unbiased p-value estimation. The superior scalability allows us to reconstruct robust gene regulatory networks from trans-effects of guide RNAs in large-scale single cell CRISPRi screens. On conventional scRNA-seq, Normalisr recovers gene-level co-expression networks that recapitulated known gene functions.


2021 ◽  
Vol 902 (1) ◽  
pp. 012047
Author(s):  
S A Asmarasari ◽  
C Sumantri ◽  
A Gunawan ◽  
E Taufik ◽  
A Anggraeni ◽  
...  

Abstract Kappa casein (CSN3) is a standout amongst the most vital milk proteins in mammals that assumes a crucial part in milk quality and coagulation. This study aimed to determine genetic polymorphism of the Kappa casein gene (CSN3) and associate its genotype variants on various cumulative milk yields in Holstein Friesian (HF) dairy cattle. A number of 61 blood samples were collected from 2 Holstein Friesian populations, respectively, from IRIAP Breeding Station in Ciawi (61) and Lembang Artificial Insemination Center (Lembang AIC) (17). Real Time -Polymerase Chain Reaction (RT-PCR) method was used to identify variant genotypes of the Kappa Casein gene. In population were detected all three genotypes GG, GT, and TT. The most frequent genotype was TT, with a frequency of 0.63. Results from the statistical association analysis between g.13975G>T CSN3 genotype and cumulative milk yield in standard lactation length were not significant.


Author(s):  
Patxi León-Guereño ◽  
Héctor Galindo-Domínguez ◽  
Eneko Balerdi-Eizmendi ◽  
Mateusz Rozmiarek ◽  
Ewa Malchrowicz-Mośko

Abstract Background Recreational running has greatly increased over the last decade, and different research has tried to understand the motivation that leads these amateur athletes to run. However, most research has focused on adult athletes, while the motivation behind older adult athletes has been overlooked. Methods The aim of this research was to analyse the motivational aspects of amateur runners aged over 50 years, and to consider the influence that years of practice, type of participation and some socio-demographical variables have on these older adults’ motivation behind running. 244 older adult amateur athletes in total completed an online survey with the 56 items contained in the motivation of marathoners scales (MOMS), 108 of whom were female (44%), and 136 were male runners (56%). Athletes were asked about their years’ running experience (< 1 year, 1–5 years, 6–10 years, > 10 years), their participation in running events (recreationally, half marathon, marathon, ultramarathon) and age (ranges 50–60, more than 60 years), gender (male, female), family life (whether in a relationship or not), and whether they had children (yes, no). Results The results showed statistical differences in the nine MOMS dimensions in terms of years’ running experience and participation in different running events. Moreover, older adult runners’ gender and age subsequently showed statistical differences with five and six motivational factors respectively, while athletes that did not have children were more likely to run regarding competition and showing recognition. Family life did not show any statistical association with any of the dimensions on the scale in this population, while regression analyses showed that, mainly, years’ running experience and participation were positively predicted, together with most motivational dimensions, while having children was negatively predicted in some of them. Conclusions This study showed that older adult runners’ reasons for participating differ from those obtained in previous studies, especially regarding training experience and participation in events. Therefore, the older adult population should be specifically addressed.


Author(s):  
Miguel Castillo ◽  
Jorge Saavedra ◽  
Tomás Quiñones ◽  
Tatiana Osses ◽  
María José Torres

The spatial and temporal behavior of the occurrence of forest fires in Chile was evaluated in the presence of COVID-19 and mobility restrictions. The fire period from 2015–2016 to 2020–2021 was considered and statistics on mobility restrictions were granted by the Government of Chile. The analysis was developed at different scales of geographic perception. At the national and regional levels, the global behavior of the occurrence was determined, and later at the communal level, the political territorial unit, to determine internal variations attributable to the mobility dynamics in the quarantine period. In the process, the meteorological background of the fire activity was also considered. The results indicate that it is possible to rule out a meteorological effect, based on the variation of the moisture content of fine fuel. There was also no statistical association between the humidity of the fuel and the variation in the occurrence of fires. It is concluded that the communes that presented the greatest mobility of people before the pandemic were those that obtained the greatest reduction in fires. The variation in mobility, the product of restriction measures, is a statistical predictor of the increase or decrease in fires.


2021 ◽  
Vol 5 (1) ◽  
pp. 015-020
Author(s):  
Katamea Tina ◽  
Mukuku Olivier ◽  
Nzala Patient Dinanga ◽  
Nsasi Bénédicte Malonda ◽  
Mpoy Charles Wembonyama ◽  
...  

Introduction: Despite advances in the management of sickle cell disease (SCD), gaps still exist in the knowledge of healthcare professionals (HCPs) about the disease. The objective of this study was to assess the knowledge of HCPs about SCD. Methods: This is a cross-sectional study involving 465 HCPs (physicians and nurses) who responded to the DFConhecimento instrument questionnaire. Performance was tested in terms of average score and proportion of correct response for each questionnaire item topic. Results: The average score for respondents was 4.6 ± 1.9 out of a total of 13 points. Proportions of professionals who responded well were greater than 58% in three topics (Neonatal screening program, Sickle cell conditions, and Sickle cell anemia genotype). In the other topics, rates of good response ranged from 11.6% to 46.0%. There was a statistical association between best performance and medical title: physicians were more knowledgeable than nurses (OR = 6.26; 95% CI: 2.69-14.56). Conclusion: This study highlighted that knowledge of SCD among HCPs is very inadequate. This lack of sufficient information on SCD from HCPs indicates the need to develop continuing education programs.


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