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A common phytoene synthase mutation underlies white petal varieties of the California poppy.
The California poppy (Eschscholzia californica) is renowned for its brilliant golden-orange flowers, though white petal variants have been described. By whole-transcriptome sequencing, we have discovered in multiple white petal varieties a single deletion leading to altered splicing and C-terminal truncation of phytoene synthase (PSY), a key enzyme in carotenoid biosynthesis. Our findings underscore the diverse roles of phytoene synthase in shaping horticultural traits, and resolve a longstanding mystery of the regaled golden poppy
The agroecology of malaria, maize, mosquitoes and dynamic landscape change in Ethiopia
PSAE Research Series No. 1
Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States
Widespread efforts to abate ozone (O3) smog have significantly reduced emissions of nitrogen oxides (NOx) over the past 2 decades in the Southeast US, a place heavily influenced by both anthropogenic and biogenic emissions. How reactive nitrogen speciation responds to the reduction in NOx emissions in this region remains to be elucidated. Here we exploit aircraft measurements from ICARTT (July–August 2004), SENEX (June–July 2013), and SEAC4RS (August–September 2013) and long-term ground measurement networks alongside a global chemistry–climate model to examine decadal changes in summertime reactive oxidized nitrogen (RON) and ozone over the Southeast US. We show that our model can reproduce the mean vertical profiles of major RON species and the total (NOy) in both 2004 and 2013. Among the major RON species, nitric acid (HNO3) is dominant (∼ 42–45%), followed by NOx (31%), total peroxy nitrates (ΣPNs; 14%), and total alkyl nitrates (ΣANs; 9–12%) on a regional scale. We find that most RON species, including NOx, ΣPNs, and HNO3, decline proportionally with decreasing NOx emissions in this region, leading to a similar decline in NOy. This linear response might be in part due to the nearly constant summertime supply of biogenic VOC emissions in this region. Our model captures the observed relative change in RON and surface ozone from 2004 to 2013. Model sensitivity tests indicate that further reductions of NOxemissions will lead to a continued decline in surface ozone and less frequent high-ozone events
Selective serotonin reuptake inhibitors in the treatment of generalized anxiety disorder
Selective serotonin reuptake inhibitors have proven efficacy in the treatment of panic disorder, obsessive–compulsive disorder, post-traumatic stress disorder and social anxiety disorder. Accumulating data shows that selective serotonin reuptake inhibitor treatment can also be efficacious in patients with generalized anxiety disorder. This review summarizes the findings of randomized controlled trials of selective serotonin reuptake inhibitor treatment for generalized anxiety disorder, examines the strengths and weaknesses of other therapeutic approaches and considers potential new treatments for patients with this chronic and disabling anxiety disorder
An online intervention for improving stroke survivors' health-related quality of life : study protocol for a randomised controlled trial
Background: Recurrent stroke is a major contributor to stroke-related disability and costs. Improving health-risk behaviours and mental health has the potential to significantly improve recovery, enhance health-related quality of life (HRQoL), independent living, and lower the risk of recurrent stroke. The primary aim will be to test the effectiveness of an online intervention to improve HRQoL among stroke survivors at 6 months' follow-up. Programme effectiveness on four health behaviours, anxiety and depression, cost-effectiveness, and impact on other hospital admissions will also be assessed. Methods/design: An open-label randomised controlled trial is planned. A total of 530 adults will be recruited across one national and one regional stroke registry and block randomised to the intervention or minimal care control group. The intervention group will receive access to the online programme Prevent 2nd Stroke (P2S); the minimal care control group will receive an email with Internet addresses of generic health sites designed for the general population. The primary outcome, HRQoL, will be measured using the EuroQol-5D. A full analysis plan will compare between groups from baseline to follow-up. Discussion: A low-cost per user option to supplement current care, such as P2S, has the potential to increase HRQoL for stroke survivors, and reduce the risk of second stroke
Testing the gravitational lensing explanation for the MgII problem in GRBs
Sixty percent of gamma-ray bursts (GRBs) reveal strong MgII absorbing
systems, which is a factor of ~2 times the rate seen along lines-of-sight to
quasars. The discrepancy in the covering factor is most likely to be the result
of either quasars being obscured due to dust, or the consequence of many GRBs
being strongly gravitationally lensed. We analyze observations of GRBs that
show strong foreground MgII absorption. We Monte-Carlo the distances between
foreground galaxies in the HUDF and lines of sight distributed randomly within
a radius derived from the covering factor, and find that galaxies are located
systematically closer to the position of the observed GRBs than expected for
random lines of sight. This over-density at small impact parameters is
statistically more robust than the well known excess of MgII absorbers among
GRB afterglow spectra, and presents a new puzzle for MgII absorption studies.
The over-density cannot be explained by obscuration in the GRB sample, but is a
natural consequence of gravitational lensing. Upon examining the particular
configurations of galaxies near a sample of GRBs with strong MgII absorption,
we find several intriguing lensing candidates. Our results suggest that lensing
provides a viable contribution to the observed enhancement of strong MgII
absorption along lines of sight to GRBs, and we outline the future observations
required to test this hypothesis conclusively.Comment: v2 includes major updates in response to referee's comments. 15
pages, 10 figures, accepted for publication in Ap
Relevance of collagen piezoelectricity to "Wolff's Law": A critical review
According to “Wolff's Law”, bone is deposited and reinforced at areas of greatest stress. From a clinical perspective, this “law” is supported by the strong association between bone density and physical activity. From a mechanistic standpoint, however, the law presents a challenge to scientists seeking to understand how osteocytes and osteoblasts sense the mechanical load. In the 1960s, collagen piezoelectricity was invoked as a potential mechanism by which osteocytes could detect areas of greater stress but piezoelectricity diminished in importance as more compelling mechanisms, such as streaming potential, were identified. In addition, accumulating evidence for the role of fluid-related shear stress in osteocyte's mechanosensory function has made piezoelectricity seemingly more obsolete in bone physiology. This review critically evaluates the role of collagen piezoelectricity (if any) in Wolff's Law—specifically, the evidence regarding its involvement in strain-generated potentials, existing alternate mechanisms, the present understanding of bone mechanosensation, and whether piezoelectricity serves an influential role within the context of this newly proposed mechanism. In addition to reviewing the literature, this review generates several hypotheses and proposes future research to fully address the relevance of piezoelectricity in bone physiology.National Center for Complementary and Alternative Medicine (U.S.) (grant K23-AT003238
Author Correction: A consensus-based transparency checklist.
An amendment to this paper has been published and can be accessed via a link at the top of the paper
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