1,437 research outputs found
ITS phylogeny of Balsamorhiza and Wyethia (Asteraceae: Heliantheae)
Journal ArticleThe relationships among the species of Balsamorhiza and Wyethia (Asteraceae: Heliantheae) were examined using data from the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA. The ITS sequences were obtained from nine species of Balsamorhiza and 14 species of Wyethia as well as seven outgroup genera
Phylogeny of Balsamorhiza and Wyethia (Asteraceae: Heliantheae) using ITS, ETS, and trnK sequence data
Journal ArticleBalsamorhiza and Wyethia together comprise 24 species native to western North America. All species in the two genera are perennial herbs with large taproots and chromosome base numbers of x = 19. The species of Balsamorhiza have exclusively basal leaves while the species of Wyethia have cauline leaves (in addition to basal leaves in some species)
Measuring Changes in Phenology of Oklahoma Asteraceae Using Herbarium Specimens
Analyzing shifts in plant flowering times (flowering phenology) in response to changing climate is crucial to understanding the impacts of climate change on plants. Herbaria contain the physical record of reproductive events from past seasons, making them an important source of long-term data for studies of phenology. We measured changes in flowering phenology of four Oklahoma native plants in the Asteraceae (sunflower) family: Grindelia ciliata, Liatris punctata, Ratibida columnifera, and Vernonia baldwinii. These species were selected to represent the morphological and phylogenetic diversity of the Asteraceae in Oklahoma and were represented in the Robert Bebb Herbarium (OKL) with over 100 specimens each. We created novel protocols for scoring the flowering phenology of these species into numeric categories, called phenophases. We looked for correlations between the collection date and both the year of collection and the temperature in that year. There was a significant relationship between collection date and year only in peak flowering specimens of G. ciliata. There was a significant relationship between statewide annual temperature and collection date only in peak flowering specimens of V. baldwinii. There was a significant relationship between the annual temperature of the climate division of the state where the plants were collected and collection date for peak flowering in G. ciliata, R. columnifera, and V. baldwinii, for first flowers in V. baldwinii, and for last flowers in L. punctata. More precise temperature data thus lead to an improvement of the model, but in all cases temperature or year explained relatively little of the total variation in flowering time
Exploring Source Credibility when Communicating about Agricultural Science on Twitter
Universities must strategically communicate agricultural science to effectively reach millennials skeptical of agricultural innovations and constantly assessing the credibility of online information. Universities are trusted information sources and must maintain credibility on social media platforms such as Twitter, used by millennials to receive and share information. Source credibility seeks to understand message source and recipient characteristics that influence recipients’ perceptions of a source’s expertise and trustworthiness. The purpose of this study was to explore differences in engagement when specific factors affecting source credibility were emphasized when communicating with millennials about agricultural science on Twitter. The purpose was accomplished by describing the level of engagement and the differences in engagement observed between perceived gender, race, and age of university scientists. Over seven months, researchers wrote press releases about published journal articles authored by two or more diverse, university-affiliated scientists. They published multiple tweets about each release, with the only difference being the scientists’ headshots. Scientists were categorized as perceived male versus female, White versus Non-White, and older versus younger. Descriptive analysis of engagement metrics from 32 tweets found those with females performed better than those with males. Non-White scientist tweets performed better with the exception of engagement rate. Tweets featuring younger scientists received more engagement than older. The exploratory results implied tweets featuring young, Non-White females may elicit higher engagement. Future studies should examine if engagement metrics are correlated with source credibility dimensions. Strategically featuring diverse scientists in research communication may be utilized to build engagement in universities’ social media
KLF9 and JNK3 Interact to Suppress Axon Regeneration in the Adult CNS
Neurons in the adult mammalian CNS decrease in intrinsic axon growth capacity during development in concert with changes in Krüppel-like transcription factors (KLFs). KLFs regulate axon growth in CNS neurons including retinal ganglion cells (RGCs). Here, we found that knock-down of KLF9, an axon growth suppressor that is normally upregulated 250-fold in RGC development, promotes long-distance optic nerve regeneration in adult rats of both sexes. We identified a novel binding partner, MAPK10/JNK3 kinase, and found that JNK3 (c-Jun N-terminal kinase 3) is critical for KLF9\u27s axon-growth-suppressive activity. Interfering with a JNK3-binding domain or mutating two newly discovered serine phosphorylation acceptor sites, Ser106 and Ser110, effectively abolished KLF9\u27s neurite growth suppression in vitro and promoted axon regeneration in vivo. These findings demonstrate a novel, physiologic role for the interaction of KLF9 and JNK3 in regenerative failure in the optic nerve and suggest new therapeutic strategies to promote axon regeneration in the adult CNS
Experimental determination of the role of increased surface area in pool boiling from nanostructured surfaces
The use of nanostructured surfaces to enhance pool boiling heat transfer performance has previously been demonstrated for a variety of outwardly-projecting nanostructures such as nanowires and nanotubes. Such enhancement has been attributed to a variety of factors, including greater surface area, improved wickability, and superior nucleation site density as compared to unmodified surfaces. However, since these three phenomena are inherently interlinked with the presence of the nanostructures, isolating each one for independent study to truly understand its relative importance in enhancing pool boiling heat transfer has remained a challenge. In this work, nanoporous anodized aluminum oxide (AAO) films on metallic aluminum (Al) substrates are used to serve as an inverse representation of an aligned nanowire array with similar increase in surface area but without inter-nanowire/nanotube wicking action or significant change in observed static wetting behavior relative to Al control samples with a solid native oxide film. Further, it is shown via a combination of experiment and analytical modeling that the AAO-covered Al samples studied here do not represent a significant increase in nucleation site density relative to the control samples. In this way, the influence of enhanced surface area of a nanostructured sample on pool boiling performance was isolated and quantitatively determined. Pool boiling performance for Al samples with solid native oxides and AAO films was measured using a custom-built test setup, with the commercial, low surface tension, dielectric coolant Novec™ HFE-7100 as the working fluid. Results were interpreted via a nanopore wetting model along with imaging analysis of bubble size, which collectively point to wickability and nucleation site density playing a greater role than increased surface area in nanostructure-based pool boiling enhancement
Measuring Changes in Phenology of Oklahoma Asteraceae Using Herbarium Specimens
Analyzing shifts in plant flowering times (flowering phenology) in response to changing climate is crucial to understanding the impacts of climate change on plants. Herbaria contain the physical record of reproductive events from past seasons, making them an important source of long-term data for studies of phenology. We measured changes in flowering phenology of four Oklahoma native plants in the Asteraceae (sunflower) family: Grindelia ciliata, Liatris punctata, Ratibida columnifera, and Vernonia baldwinii. These species were selected to represent the morphological and phylogenetic diversity of the Asteraceae in Oklahoma and were represented in the Robert Bebb Herbarium (OKL) with over 100 specimens each. We created novel protocols for scoring the flowering phenology of these species into numeric categories, called phenophases. We looked for correlations between the collection date and both the year of collection and the temperature in that year. There was a significant relationship between collection date and year only in peak flowering specimens of G. ciliata. There was a significant relationship between statewide annual temperature and collection date only in peak flowering specimens of V. baldwinii. There was a significant relationship between the annual temperature of the climate division of the state where the plants were collected and collection date for peak flowering in G. ciliata, R. columnifera, and V. baldwinii, for first flowers in V. baldwinii, and for last flowers in L. punctata. More precise temperature data thus lead to an improvement of the model, but in all cases temperature or year explained relatively little of the total variation in flowering time.The authors thank the MPBIO department at the University of Oklahoma for supporting John Unterschuetz with the George L. and Cleo Cross Endowed Scholarship as an undergraduate student researcher during this investigation.Ye
Low-dose aspirin for the prevention of preterm delivery in nulliparous women with a singleton pregnancy (ASPIRIN): a randomised, double-blind, placebo-controlled trial.
BACKGROUND: Preterm birth remains a common cause of neonatal mortality, with a disproportionately high burden in low-income and middle-income countries. Meta-analyses of low-dose aspirin to prevent pre-eclampsia suggest that the incidence of preterm birth might also be decreased, particularly if initiated before 16 weeks of gestation.
METHODS: ASPIRIN was a randomised, multicountry, double-masked, placebo-controlled trial of low-dose aspirin (81 mg daily) initiated between 6 weeks and 0 days of pregnancy, and 13 weeks and 6 days of pregnancy, in nulliparous women with an ultrasound confirming gestational age and a singleton viable pregnancy. Participants were enrolled at seven community sites in six countries (two sites in India and one site each in the Democratic Republic of the Congo, Guatemala, Kenya, Pakistan, and Zambia). Participants were randomly assigned (1:1, stratified by site) to receive aspirin or placebo tablets of identical appearance, via a sequence generated centrally by the data coordinating centre at Research Triangle Institute International (Research Triangle Park, NC, USA). Treatment was masked to research staff, health providers, and patients, and continued until 36 weeks and 7 days of gestation or delivery. The primary outcome of incidence of preterm birth, defined as the number of deliveries before 37 weeks\u27 gestational age, was analysed in randomly assigned women with pregnancy outcomes at or after 20 weeks, according to a modified intention-to-treat (mITT) protocol. Analyses of our binary primary outcome involved a Cochran-Mantel-Haenszel test stratified by site, and generalised linear models to obtain relative risk (RR) estimates and associated confidence intervals. Serious adverse events were assessed in all women who received at least one dose of drug or placebo. This study is registered with ClinicalTrials.gov, NCT02409680, and the Clinical Trial Registry-India, CTRI/2016/05/006970.
FINDINGS: From March 23, 2016 to June 30, 2018, 14 361 women were screened for inclusion and 11 976 women aged 14-40 years were randomly assigned to receive low-dose aspirin (5990 women) or placebo (5986 women). 5780 women in the aspirin group and 5764 in the placebo group were evaluable for the primary outcome. Preterm birth before 37 weeks occurred in 668 (11·6%) of the women who took aspirin and 754 (13·1%) of those who took placebo (RR 0·89 [95% CI 0·81 to 0·98], p=0·012). In women taking aspirin, we also observed significant reductions in perinatal mortality (0·86 [0·73-1·00], p=0·048), fetal loss (infant death after 16 weeks\u27 gestation and before 7 days post partum; 0·86 [0·74-1·00], p=0·039), early preterm delivery (\u3c34 \u3eweeks; 0·75 [0·61-0·93], p=0·039), and the incidence of women who delivered before 34 weeks with hypertensive disorders of pregnancy (0·38 [0·17-0·85], p=0·015). Other adverse maternal and neonatal events were similar between the two groups.
INTERPRETATION: In populations of nulliparous women with singleton pregnancies from low-income and middle-income countries, low-dose aspirin initiated between 6 weeks and 0 days of gestation and 13 weeks and 6 days of gestation resulted in a reduced incidence of preterm delivery before 37 weeks, and reduced perinatal mortality.
FUNDING: Eunice Kennedy Shriver National Institute of Child Health and Human Development
Spatially periodic vapor bubble activity during subcooled pool boiling on 1D aluminum alloy micro-fin arrays
Within the broad field of micro- and nano- scale surface modification to improve pool boiling performance, micro-fin arrays are especially attractive due to their ability to significantly increase wetted surface area with minimal increase in size or weight compared to macroscopic fins. In addition, their regular and repeating geometry enables greater potential for parametric optimization, uniformity, and repeatability as compared to more randomized alternatives. However, the presence of a regular, repeating microscale pattern on a heated surface has previously been shown to create alternating regions of liquid and vapor flow at small length scales which can strongly affect the macroscopic heat transfer performance of the surface. In this work, a combination of pool boiling experiments, high-speed imaging, and numerical modeling were used to investigate vapor bubble behavior and pool boiling heat transfer characteristics from one-dimensional (1D) aluminum alloy micro-fin arrays in the dielectric coolant HFE-7100. Results showed that the presence of 1D micro-fin arrays can significantly enhance pool boiling performance above that of a planar, unpatterned baseline surface but with important and sometimes nonintuitive dependence on micro-fin height. Experimental data indicated that a simple increase in surface area does not necessarily correlate to improved heat transfer performance, while high-speed imaging revealed that the presence of the micro-fins induces a periodic series of upward and downward flow patterns, in addition to distinct vapor bubble migration behavior. These results expand the range of surface types and working fluids for which spatially periodic and distinct liquid/vapor transport pathways created via microscale surface modification have been reported
The Student Movement Volume 107 Issue 6: Night Market Lights Up Andrews Campus
HUMANS
Meet Franky Paypa, AUSA Executive Secretary, Interviewed by: Lauren Kim
Meet 19-Year-Old Female CS Major: Andrea Stanko, Interviewed by Kavya Mohanram
Meet Jaden Leiterman, AFIA President, Interviewed by: Nora Martin
ARTS & ENTERTAINMENT
WAUS: A Michiana Music Oasis, Aiko J. Ayala Rios
Conductor Profile: Dr. Marc Élysée, Wambui Karanja
Currently..., Solana Campbell
That\u27s What I Like! The Essential Filipino Jam Playlist, Bella Hamann
NEWS
Community Engagement Initiative Celebrates Third Year, Scott Moncrieff
Illegal Exports: Why Mexico is Suing US Arms Dealers, Julia Randall
KASA x SASA Night Market, Alannah Tjhatra
IDEAS
DeFINE Chapel: A Proposition, Bella Hamann
Docuseries: To Love or to Hate?, Abigail Shim
For the Love of Food: A Celebration of Filipino American Cuisine, Rachel Ingram-Clay
PULSE
A Guide to Worship in Berrien Springs, Zothile Sibanda
Help Me! How To Survive The Mid-Semester Crisis, Amelia Stefanescu
Students Speak on Co-Curricular Credits, Wambui Karanja
The Gazebo\u27s Post-Covid Makeover, Melissa Moore
LAST WORD
The Meaning of Student Movement , Alannah Tjhatrahttps://digitalcommons.andrews.edu/sm-107/1005/thumbnail.jp
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