statistical support
Recently Published Documents


TOTAL DOCUMENTS

214
(FIVE YEARS 87)

H-INDEX

18
(FIVE YEARS 5)

2022 ◽  
Vol 25 ◽  
pp. 16-21
Author(s):  
Thomas J. Simonsen ◽  
Marcus Glahder ◽  
Thomas Pape ◽  
Kent Olsen ◽  
Marie Djernæs

We reconstruct a phylogenetic framework for the zygopteran family Lestidae based on a molecular dataset comprised of sequence data from the genes COI, 16S, 18S, 28S, and ITS1+2 from 41 ingroup taxa and 8 outgroup taxa with emphasis on the systematic position of the genus Chalcolestes Kennedy. We recover Lestidae as monophyletic with good statistical support. The family falls into two subequal clades. One, comprising the genus Sympecma Burmeister and Lestes Leach sensu lato (including the genus Archi­lestes Selys) is poorly to moderately supported. While the other, comprising the genera Austrolestes Tillyard, Indolestes Fraser, Orolestes McLachlan, and Chalcolestes is strongly supported. Chalcolestes is recovered as sister to the Oriental genus Orolestes with strong support. Our results thus support that Chalcolestes is a valid genus not closely related to Lestes. Monophyly of Lestes requires inclusion of the New World genus Archilestes, and our results support the need for a thorough revision of Lestes.


Phytotaxa ◽  
2022 ◽  
Vol 530 (1) ◽  
pp. 65-76
Author(s):  
RUIFANG XU ◽  
KEVIN D. HYDE ◽  
SAMANTHA C. KARUNARATHNA ◽  
JIAN-CHU XU ◽  
PETER E. MORTIMER ◽  
...  

During a survey of rubber tree plantations in Yunnan Province, China, a fungus growing on natural rubber latex was collected and isolated. Maximum likelihood and Bayesian analyses of combined ITS, LSU, SSU, tef-α and rpb2 genes showed the isolated taxon belongs to Wiesneriomycetaceae and was well separated from closely related genera with high statistical support. It can be differentiated from other genera in Wiesneriomycetaceae by synnemata with catenate conidia that are cylindrical, 0–4 to multi-septate, often with a dark brown band at the septa. Morphology, phylogenetic analyses and pairwise homoplasy index (PHI) tests provide evidence that the new isolate is a distinct genus. The genus Heveicola is introduced, with H. xishuangbannaensis as the type species. A key to the genera in Wiesneriomycetaceae is also provided.


2022 ◽  
Vol 9 ◽  
Author(s):  
Gordon W. Schuett ◽  
Randall S. Reiserer ◽  
Andrew M. Salywon ◽  
Steven Blackwell ◽  
Wendy C. Hodgson ◽  
...  

The importance of vertebrate animals as seed dispersers (zoochory) has received increasing attention from researchers over the past 20 years, yet one category in particular, diploendozoochory, remains understudied. As the term implies, this is a two-phase seed dispersal system whereby a secondary seed predator (carnivorous vertebrate) consumes a primary seed predator or granivore (rodent and bird) with undamaged seeds in their digestive tract (mouth, cheek pouch, crop, stomach, or other organ), which are subsequently eliminated with feces. Surprisingly, although snakes are among the most abundant predators of granivorous vertebrates, they are the least studied group insofar as our knowledge of seed rescue and secondary dispersal in a diploendozoochorous system. Here, using live snake subjects of the Sonoran Desert (one viperid and two colubrid species) and seeds of the Foothill Palo Verde (Parkinsonia microphylla), a dominant tree of the same region, we experimentally tested germination frequency and rate, and seedling viability. Specifically, to mimic rodents with seed-laden cheek pouches, we tested whether wild-collected P. microphylla seeds placed in the abdomen of thawed laboratory mice and ingested by the snakes would retain their germination viability. Second, we examined whether seeds exposed to gut transit germinated at a greater frequency and rate than the controls. While we found strong statistical support for our first hypothesis, both aspects of the second one were not significant. Accordingly, we provide an explanation for these results based on specific life-history traits (dormant and non-dormant seeds) of P. microphylla. Our study provides support for the role of snakes as important agents of seed rescue and dispersal in nature, their potential as ecosystem engineers, and crucial evidence for the investment of field-based studies on diploendozoochorous systems in deserts and other ecosystems.


2021 ◽  
Author(s):  
Paulo S.P. Silveira ◽  
Joaquim E. Vieira ◽  
Alexandre A. Ferraro ◽  
Jose O. Siqueira

Abstract Background: Bland and Altman plot method is a widely cited graphical approach to assess equivalence of quantitative measurement techniques. Perhaps due to its graphical output, it has been widely applied, however often misinterpreted by lacking of inferential statistical support. To compare data sets obtained from two measurement techniques, researchers may apply Pearson’s correlation, ordinal least-square linear regression, or the Bland-Altman plot methods, failing to locate the weakness of each measurement technique. We aim to develop and distribute a statistical method in R in order to add robust and suitable inferential statistics of equivalence. Methods: Three nested tests based on structural regressions are proposed to assess the equivalence of structural means (accuracy), equivalence of structural variances (precision), and concordance with the structural bisector line (agreement in measurements of data pairs obtained from the same subject) to reach statistical support for the equivalence of measurement techniques. Graphical outputs illustrating these three tests were added to follow Bland and Altman’s principles of easy communication. Results: Statistical p-values and robust approach by bootstrapping with corresponding graphs provide objective, robust measures of equivalence. Five pairs of data sets were analyzed in order to criticize previously published articles that applied the Bland and Altman’s principles, thus showing the suitability of the present statistical approach. In one case it was demonstrated strict equivalence, three cases showed partial equivalence, and one case showed poor equivalence. Package containing open codes and data is available with installation instructions on SourceForge for free distribution. Conclusions: Statistical p-values and robust approach assess the equivalence of accuracy, precision, and agreement for measurement techniques. Decomposition in three tests helps the location of any disagreement as a means to fix a new technique.


2021 ◽  
Author(s):  
Ronald E Crump ◽  
Ching-I Huang ◽  
Simon E F Spencer ◽  
Paul E Brown ◽  
Chansy Shampa ◽  
...  

Gambiense human African trypanosomiasis (gHAT) has been targeted for elimination of transmission (EoT) to humans by 2030. Whilst this ambitious goal is rapidly approaching, there remain fundamental questions about the presence of non-human animal transmission cycles and their potential role in slowing progress towards, or even preventing, EoT. In this study we focus on the country with the most gHAT disease burden, the Democratic Republic of Congo (DRC), and use mathematical modelling to assess whether animals may contribute to transmission in specific regions, and if so, how their presence could impact the likelihood and timing of EoT. By fitting two model variants – one with, and one without animal transmission – to the human case data from 2000–2016 we estimate model parameters for 158 endemic health zones of DRC. We evaluate the statistical support for each model variant in each health zone and infer the contribution of animals to overall transmission and how this could impact predicted time to EoT. We conclude that there are 24/158 health zones where there is moderate or high statistical support for some animal transmission. However, – even in these regions – we estimate that animals would be extremely unlikely to maintain transmission on their own. Animal transmission could hamper progress towards EoT in some settings, with projections under continuing interventions indicating that the number of health zones expected to achieve EoT by 2030 reduces from 68 to 61 if animals are included in the model. With supplementary vector control (at a modest 60% tsetse reduction) added to medical screening and treatment interventions, the predicted number of health zones meeting the goal increases to 147/158 for the model including animals. This is due to the impact of vector reduction on transmission to and from all hosts.


Phytotaxa ◽  
2021 ◽  
Vol 528 (2) ◽  
pp. 111-124
Author(s):  
LI LU ◽  
SAOWALUCK TIBPROMMA ◽  
SAMANTHA KARUNARATHNA ◽  
VINODHINI THIYAGARAJA ◽  
JIANCHU XU ◽  
...  

Coffee, an important economic crop, is often threatened by fungal infections. During a survey of coffee fungi in Yunnan Province, China, two saprobic Stictidaceae species were collected. Maximum likelihood (ML) and Bayesian posterior probability of combined LSU, ITS and mtSSU genes supported the placement of our fungal collections within Fitzroyomyces and Ostropomyces with high statistical support. A new species, Fitzroyomyces yunnanensis sp. nov. and a new record, Ostropomyces pruinosellus are introduced. These two species were recorded on coffee wood in sexual and asexual states, respectively. Their taxonomic placements were further supported by detailed morphological and phylogenetic comparisons of allied taxa.


2021 ◽  
Author(s):  
Kayleigh Rose O'Keeffe ◽  
Brandon T Wheeler ◽  
Charles E Mitchell

The interactions among host-associated microbes and parasites can have clear consequences for disease susceptibility and progression within host individuals. Yet, empirical evidence for how these interactions impact parasite transmission between host individuals remains scarce. We address this scarcity by using a field mesocosm experiment to investigate the interaction between a systemic fungal endophyte, Epichloe coenophiala, and a fungal parasite, Rhizoctonia solani, in leaves of a grass host, tall fescue. Specifically, we investigated how this interaction impacted parasite transmission under field conditions in replicated experimental host populations. Epichloe-inoculated populations tended to have greater disease prevalence over time, though this difference had weak statistical support. More clearly, Epichloe-inoculated populations experienced higher peak parasite prevalences than Epichloe-free populations. Epichloe conferred a benefit in growth; Epichloe-inoculated populations had greater aboveground biomass than Epichloe-free populations. Using biomass as a proxy, host density was correlated with peak parasite prevalence, but Epichloe still increased peak parasite prevalence after controlling for the effect of biomass. Together, these results suggest that within-host microbial interactions can impact disease at the population level. Further, while Epichloe is clearly a mutualist of tall fescue, it may not be a defensive mutualist in relation to R. solani.


Author(s):  
Bradley Beatson ◽  
Alex Pham ◽  
Sally S. Ong ◽  
Ishrat Ahmed ◽  
J. Fernando Arevalo ◽  
...  

Abstract Background Degenerative retinoschisis is a common condition defined by the splitting of the neurosensory retina that may rarely be associated with progressive retinal detachment (RD). Here, we aim to describe the anatomic and functional outcomes of surgical treatment of progressive symptomatic retinal detachment complicating degenerative retinoschisis (PSRDCR) using pars plana vitrectomy (PPV), scleral buckle (SB), or combined PPV/SB procedure. Methods A retrospective chart review of patients with PSRDCR between Jan 1, 2008 and Dec 31, 2019 was conducted. Data regarding demographics, surgical approach, and anatomic/functional outcomes were collected. Results Of the 4973 charts with RD repair during the study period, 36 eyes (0.7%) had retinoschisis with RD. 18 eyes met inclusion criteria (0.4%). The median age was 54 years (range 18–74) and all eyes were phakic. All eyes had outer layer breaks (OLBs) and 16 eyes (89%) had identifiable inner layer breaks. All OLBs were posterior to the equator in charts where position was recorded (16 eyes). The single surgery anatomic success (SSAS) and final anatomical success rates were 66% (12/18) and 100%, respectively. Eyes treated with PPV/SB had an SSAS rate of 75% (9/12), while PPV and SB had SSAS rates of 66% (2/3) and 33% (1/3), respectively. Conclusions PSRDCR is an exceedingly rare complication of degenerative retinoschisis associated with an SSAS rate lower than for uncomplicated rhegmatogenous RD. The majority of PSRDCR were repaired via combined PPV/SB in our study, and the rarity of this complication limits statistical support of an optimal surgical method in our and prior studies. The role of SB combined with PPV for PSRDCR requires further investigation.


Phytotaxa ◽  
2021 ◽  
Vol 524 (4) ◽  
pp. 283-292
Author(s):  
XINGGUO TIAN ◽  
SAMANTHA C. KARUNARATHNA ◽  
AUSANA MAPOOK ◽  
JIANCHU XU ◽  
DANFENG BAO ◽  
...  

A new species of Koorchaloma is described based on morphology and multigene phylogenetic analyses of ITS, LSU and RPB2. Phylogenetic analyses showed our strain clusters with K. europaea with moderate statistical support. Koorchaloma oryzae sp. nov. is morphologically similar to K. europaea, but it can be distinguished by the conidiophores and conidia, while ITS pairwise nucleotide comparison of these two species also revealed differences. Koorchaloma oryzae is compared with all known Koorchaloma species, and a key to Koorchaloma species is provided. Genealogical concordance phylogenetic species recognition analysis (PHI test) results of the new species and closely related species are also given.


2021 ◽  
Vol 24 (2) ◽  
pp. 32-61
Author(s):  
Rob Weitz ◽  
Viswa Viswanathan ◽  
David Rosenthal

In the summer of 2020, as the COVID-19 pandemic continued to spread around the world, institutions of higher education were faced with three options in terms of their teaching modality for fall 2020: resume in-person education, switch to online delivery, or adopt a hybrid approach. This observational research study aims to tease out the variables that explain the decisions announced in summer 2020 by various colleges and universities in the United States for their planned instruction for fall 2020. We propose and test eight hypotheses related to the decision. The study found statistical confirmation that universities with higher financial stability and/or prestige tended to select the online delivery option, while lower financial stability/prestige showed a preference to stay with in-person delivery. We also found public institutions were more likely to go online than private ones. Additionally, we found statistical support for our hypotheses that universities located in Republican leaning states and also those with a religious affiliation would prefer the in-person modality. The results also confirmed our hypothesis that universities offering a higher percentage of humanities degrees would have a greater probability of choosing the in-person modality. Interestingly, we did not find statistical support for our hypothesis that the level of COVID spread in the geographical area of a university’s location would affect its decision.


Sign in / Sign up

Export Citation Format

Share Document