2,960 research outputs found
AXR3 and SHY2 interact to regulate root hair development
Signal transduction of the plant hormone auxin centres on the regulation of the abundance of members of the Aux/IAA family of transcriptional regulators, of which there are 29 in Arabidopsis. Auxin can influence Aux/IAA abundance by promoting the transcription of Aux/IAA genes and by reducing the half-life of Aux/IAA proteins. Stabilising mutations, which render Aux/IAA proteins resistant to auxin-mediated degradation, confer a wide range of phenotypes consistent with disruptions in auxin response. Interestingly, similar mutations in different family members can confer opposite phenotypic effects. To understand the molecular basis for this functional specificity in the Aux/IAA family, we have studied a pair of Aux/IAAs, which have contrasting roles in root hair development. We have found that stabilising mutations in AXR3/IAA17 blocks root hair initiation and elongation, whereas similar mutations in SHY2/IAA3 result in early initiation of root hair development and prolonged hair elongation, giving longer root hairs. The phenotypes resulting from double mutant combinations, the transient induction of expression of the proteins, and the pattern of transcription of the cognate genes suggest that root hair initiation is controlled by the relative abundance of SHY2 and AXR3 in a cell. These results suggest a general model for auxin signalling in which the modulation of the relative abundance of different Aux/IAA proteins can determine which down-stream responses are induced
CMB Power Spectrum Estimation via Hierarchical Decomposition
We have developed a fast, accurate and generally applicable method for
inferring the power spectrum and its uncertainties from maps of the cosmic
microwave background (CMB) in the presence of inhomogeneous and correlated
noise. For maps with 10 to 100 thousand pixels, we apply an exact power
spectrum estimation algorithm to submaps of the data at various resolutions,
and then combine the results in an optimal manner. To analyze larger maps
efficiently one must resort to sub-optimal combinations in which cross-map
power spectrum error correlations are only calculated approximately. We expect
such approximations to work well in general, and in particular for the
megapixel maps to come from the next generation of satellite missions.Comment: 10 pages, 5 figures, to be submitted to Phys. Rev.
Sexual Attraction Toward Clients, Use of Supervision, and Prior Training: A Qualitative Study of Predoctoral Psychology Interns
Interviews were conducted with 13 predoctoral psychology interns about an experience of sexual attraction toward a client, use of supervision to address the sexual attraction, and prior training regarding sexual attraction. Results indicated that sexual attraction to clients consisted of physical and interpersonal aspects. Therapists believed they were more invested and attentive than usual to clients to whom they were sexually attracted, and they indicated that sexual attraction created distance, distraction, and loss of objectivity. In terms of supervision, only half of the participants disclosed their sexual attraction to supervisors, and supervisors seldom initiated the discussion. Furthermore, trainees found it helpful when supervisors normalized the sexual attraction and provided the opportunity to explore feelings in supervision. Finally, trainees believed their training programs did not adequately address therapist sexual attraction
Urban Partnerships to Address Health Literacy in High Need Populations
Low health literacy disproportionately affects racial and ethnic minority communities and lower-income socioeconomic groups. To address this critical determinant of health inequity, two nonprofit organizations, Repairers of the Breach, a day shelter for individuals experiencing homelessness, and Bread of Healing a neighborhood-based clinic serving individuals with low incomes, partnered with researchers at Marquette University to implement and evaluate an evidence-supported health literacy program. The partnership delivered the curriculum in seven one-hour sessions over seven weeks. The program attendees were predominantly African American men and women from 19–73 years old. Most participants had formal education ranging from elementary school to some college. Forty individuals attended at least one class and 14 attendees completed 4 or more classes. Program completers demonstrated gains in confidence and topic knowledge. Most interviewees reported a personal/family need for the program, acceptability of the group format, and the ability to learn the skills they needed for self-care. The project used a successful collaboration between community-based organizations serving vulnerable populations and an urban academic institution to demonstrate the necessity, feasibility, acceptability, and effectiveness of formal health literacy education in adults with low incomes or who are experiencing homelessness. Urban and metropolitan serving institutions can work in partnership with community to address low health literacy in high need populations
On the jets, kinks, and spheromaks formed by a planar magnetized coaxial gun
Measurements of the various plasma configurations produced by a planar
magnetized coaxial gun provide insight into the magnetic topology evolution
resulting from magnetic helicity injection. Important features of the
experiments are a very simple coaxial gun design so that all observed
geometrical complexity is due to the intrinsic physical dynamics rather than
the source shape and use of a fast multiple-frame digital camera which provides
direct imaging of topologically complex shapes and dynamics. Three key
experimental findings were obtained: (1) formation of an axial collimated jet
[Hsu and Bellan, Mon. Not. R. Astron. Soc. 334, 257 (2002)] that is consistent
with a magnetohydrodynamic description of astrophysical jets, (2)
identification of the kink instability when this jet satisfies the
Kruskal-Shafranov limit, and (3) the nonlinear properties of the kink
instability providing a conversion of toroidal to poloidal flux as required for
spheromak formation by a coaxial magnetized source [Hsu and Bellan, Phys. Rev.
Lett. 90, 215002 (2003)]. A new interpretation is proposed for how the n=1
central column instability provides flux amplification during spheromak
formation and sustainment, and it is shown that jet collimation can occur
within one rotation of the background poloidal field.Comment: Physics of Plasmas (accepted
Modeling Extragalactic Foregrounds and Secondaries for Unbiased Estimation of Cosmological Parameters From Primary CMB Anisotropy
Using the latest physical modeling and constrained by the most recent data,
we develop a phenomenological parameterized model of the contributions to
intensity and polarization maps at millimeter wavelengths from external
galaxies and Sunyaev-Zeldovich effects. We find such modeling to be necessary
for estimation of cosmological parameters from Planck data. For example,
ignoring the clustering of the infrared background would result in a bias in
n_s of 7 sigma. We show that the simultaneous marginalization over a full
foreground model can eliminate such biases, while increasing the statistical
uncertainty in cosmological parameters by less than 20%. The small increases in
uncertainty can be significantly reduced with the inclusion of
higher-resolution ground-based data.
The multi-frequency analysis we employ involves modeling 46 total power
spectra and marginalization over 17 foreground parameters. We show that we can
also reduce the data to a best estimate of the CMB power spectra, and just two
principal components (with constrained amplitudes) describing residual
foreground contamination.Comment: 17 pages, 7 figures, submitted to Ap
Spirometry parameters used to define small airways obstruction in population-based studies: Systematic review
Background The assessment of small airways obstruction (SAO) using spirometry is practiced in population-based studies. However, it is not clear what are the most used parameters and cut-offs to define abnormal results. Methods We searched three databases (Medline, Web of Science, Google Scholar) for population-based studies, published by 1 May 2021, that used spirometry parameters to identify SAO and/or provided criteria for defining SAO. We systematically reviewed these studies and summarised evidence to determine the most widely used spirometry parameter and criteria for defining SAO. In addition, we extracted prevalence estimates and identified associated risk factors. To estimate a pooled prevalence of SAO, we conducted a meta-analysis and explored heterogeneity across studies using meta regression. Results Twenty-five studies used spirometry to identify SAO. The most widely utilised parameter (15 studies) was FEF25–75, either alone or in combination with other measurements. Ten studies provided criteria for the definition of SAO, of which percent predicted cut-offs were the most common (5 studies). However, there was no agreement on which cut-off value to use. Prevalence of SAO ranged from 7.5% to 45.9%. As a result of high heterogeneity across studies (I2 = 99.3%), explained by choice of spirometry parameter and WHO region, we do not present a pooled prevalence estimate. Conclusion There is a lack of consensus regarding the best spirometry parameter or defining criteria for identification of SAO. The value of continuing to measure SAO using spirometry is unclear without further research using large longitudinal data. PROSPERO registration number CRD4202125020
Predicting Landscape-Scale CO 2 Flux at a Pasture and Rice Paddy with Long-Term Hyperspectral Canopy Reflectance Measurements
Measurements of hyperspectral canopy reflectance provide a detailed snapshot of information regarding canopy biochemistry, structure and physiology. In this study, we collected 5 years of repeated canopy hyperspectral reflectance measurements for a total of over 100 site visits within the flux footprints of two eddy covariance towers at a pasture and rice paddy in northern California. The vegetation at both sites exhibited dynamic phenology, with significant interannual variability in the timing of seasonal patterns that propagated into interannual variability in measured hyperspectral reflectance. We used partial least-squares regression (PLSR) modeling to leverage the information contained within the entire canopy reflectance spectra (400–900 nm) in order to investigate questions regarding the connection between measured hyperspectral reflectance and landscape-scale fluxes of net ecosystem exchange (NEE) and gross primary productivity (GPP) across multiple timescales, from instantaneous flux to monthly integrated flux
The origin of Dendrosenecio within the Senecioneae (Asteraceae) based on chloroplastDNA EVIDENCE
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141916/1/ajb213859.pd
Mind the Gap: Integration of International Students
The international mobilisation of tertiary students is increasing from 0.8 million in 1975 to 3.5 million worldwide by 2016 (OECD, 2018). This increasingly fluid student migration, supported with various European initiatives, the Erasmus exchange program (since 1987) and the Bologna Declaration (since 1999), have influenced the profile of students within the Irish higher education system. By 2016, international students comprised 5.1% of total tertiary students in Ireland (OECD, 2018). According to Irish and UK research, lecturers have an important role in facilitating integration (British Council, 2014; Irish Council for International Students, 2017). However, for most faculty, the term internationalisation of the curriculum was unfamiliar (Clarke, Hui Yang & Harmon, 2018) and faculty also had mixed views on a need to explicitly address cultural and language issues in their learning outcomes or assessment tasks. Although some faculty viewed intercultural training as important most had not received this kind of support (Clarke et al., 2018). This report focuses on the integration challenges international students face, and what best-practice recommendations are available to assist lecturers in aiding integration
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