8,568 research outputs found
Sequential Flavour Symmetry Breaking
The gauge sector of the Standard Model (SM) exhibits a flavour symmetry which
allows for independent unitary transformations of the fermion multiplets. In
the SM the flavour symmetry is broken by the Yukawa couplings to the Higgs
boson, and the resulting fermion masses and mixing angles show a pronounced
hierarchy. In this work we connect the observed hierarchy to a sequence of
intermediate effective theories, where the flavour symmetries are broken in a
step-wise fashion by vacuum expectation values of suitably constructed spurion
fields. We identify the possible scenarios in the quark sector and discuss some
implications of this approach.Comment: 22 pages latex, no figure
Development and trialling of a tool to support a systems approach to improve social determinants of health in rural and remote Australian communities: the healthy community assessment tool
IntroductionThe residents of many Australian rural and remote communities do not have the essential infrastructure and services required to support healthy living conditions and community members choosing healthy lifestyle options. Improving these social determinants of health is seen to offer real opportunities to improve health among such disadvantaged populations. In this paper, we describe the development and trialling of a tool to measure, monitor and evaluate key social determinants of health at community level. MethodsThe tool was developed and piloted through a multi-phase and iterative process that involved a series of consultations with community members and key stakeholders and trialling the tool in remote Indigenous communities in the Northern Territory of Australia. ResultsThe indicators were found to be robust, and by testing the tool on a number of different levels, face validity was confirmed. The scoring system was well understood and easily followed by Indigenous and non-Indigenous study participants. A facilitated small group process was found to reduce bias in scoring of indicators. ConclusionThe Healthy Community Assessment Tool offers a useful vehicle and process to help those involved in planning, service provision and more generally promoting improvements in community social determinants of health. The tool offers many potential uses and benefits for those seeking to address inequities in the social determinants of health in remote communities. Maximum benefits in using the tool are likely to be gained with cross-sector involvement and when assessments are part of a continuous quality improvement program
Disordered eating and internalizing symptoms in preadolescence
Objectives
Research has demonstrated links between disordered eating, anxiety, and depression in adults and adolescents but there is limited research investigating these associations in preadolescence. The current study examined the associations between disordered eating, anxiety, and depression during preadolescence, as well as the role of gender in moderating these associations.
Method
Two hundred and thirteen children (M = 10.3 years; 51.2% male) reported levels of disordered eating (ChEAT) and anxiety and depression symptoms (RCADSā25).
Results
Regression analyses support an association between disordered eating and both anxiety and depression in preadolescence. Overall, there were no significant differences between boys and girls when the main effect was examined, which differs from research in adolescents.
Discussion
These findings highlight the importance of early detection for disordered eating behaviors and attitudes, as well as anxiety and depression in both boys and girls during preadolescence. Longitudinal research examining these associations is vital to help understand the trajectories of these problems, but also the gender differences in disordered eating that emerge during adolescence. Transdiagnostic interventions targeting several coāoccurring problems, such as disordered eating, anxiety, and depression might be effective for preventing the development of eating disorders in the long term
Approaching the adiabatic timescale with machine-learning
The control and manipulation of quantum systems without excitation is
challenging, due to the complexities in fully modeling such systems accurately
and the difficulties in controlling these inherently fragile systems
experimentally. For example, while protocols to decompress Bose-Einstein
condensates (BEC) faster than the adiabatic timescale (without excitation or
loss) have been well developed theoretically, experimental implementations of
these protocols have yet to reach speeds faster than the adiabatic timescale.
In this work, we experimentally demonstrate an alternative approach based on a
machine learning algorithm which makes progress towards this goal. The
algorithm is given control of the coupled decompression and transport of a
metastable helium condensate, with its performance determined after each
experimental iteration by measuring the excitations of the resultant BEC. After
each iteration the algorithm adjusts its internal model of the system to create
an improved control output for the next iteration. Given sufficient control
over the decompression, the algorithm converges to a novel solution that sets
the current speed record in relation to the adiabatic timescale, beating out
other experimental realizations based on theoretical approaches. This method
presents a feasible approach for implementing fast state preparations or
transformations in other quantum systems, without requiring a solution to a
theoretical model of the system. Implications for fundamental physics and
cooling are discussed.Comment: 7 pages main text, 2 pages supporting informatio
In Situ Mapping of the Organic Matter in Carbonaceous Chondrites and Mineral Relationships
Carbonaceous chondrite organic matter represents a fossil record of reactions that occurred in a range of physically, spatially and temporally distinct environments, from the interstellar medium to asteroid parent bodies. While bulk chemical analysis has provided a detailed view of the nature and diversity of this organic matter, almost nothing is known about its spatial distribution and mineralogical relationships. Such information is nevertheless critical to deciphering its formation processes and evolutionary history
Phosphorylation at serines 104 and 106 by Erk1/2 MAPK is important for estrogen receptor-Ī± activity
Phosphorylation of estrogen receptor-Ī± (ERĪ±) at specific residues in transcription activation function 1 (AF-1) can stimulate ERĪ± activity in a ligand-independent manner. This has led to the proposal that AF-1 phosphorylation and the consequent increase in ERĪ± activity could contribute to resistance to endocrine therapies in breast cancer patients. Previous studies have shown that serine 118 (S118) in AF-1 is phosphorylated by extracellular signal-regulated kinases 1 and 2 (Erk1/2) mitogen-activated protein kinase (MAPK) in a ligand-independent manner. Here, we show that serines 104 (S104) and 106 (S106) are also phosphorylated by MAPK in vitro and upon stimulation of MAPK activity in vivo. Phosphorylation of S104 and S106 can be inhibited by the MAP-erk kinase (MEK)1/2 inhibitor U0126 and by expression of kinase-dead Raf1. Further, we show that, although S118 is important for the stimulation of ERĪ± activity by the selective ER modulator 4-hydroxytamoxifen (OHT), S104 and S106 are also required for the agonist activity of OHT. Acidic amino acid substitution of S104 or S106 stimulates ERĪ± activity to a greater extent than the equivalent substitution at S118, suggesting that phosphorylation at S104 and S106 is important for ERĪ± activity. Collectively, these data indicate that the MAPK stimulation of ERĪ± activity involves the phosphorylation not only of S118 but also of S104 and S106, and that MAPK-mediated hyperphosphorylation of ERĪ± at these sites may contribute to resistance to tamoxifen in breast cancer
FE-SEM, FIB and TEM Study of Surface Deposits of Apollo 15 Green Glass Volcanic Spherules
Surface deposits on lunar pyroclastic green (Apollo 15) and orange (Apollo 17) glass spherules have been attributed to condensation from the gas clouds that accompanied fire-fountain eruptions. The fire fountains cast molten lava high above the lunar surface and the silicate melt droplets quenched before landing producing the glass beads. Early investigations showed that these deposits are rich in sulfur and zinc. The deposits are extremely fine-grained and thin, so that it was never possible to determine their chemical compositions cleanly by SEM/EDX or electron probe x-ray analysis because most of the excited volume was in the under-lying silicate glass. We are investigating the surface deposits by TEM, using focused ion beam (FIB) microscopy to extract and thin the surface deposits. Here we report on chemical mapping of a FIB section of surface deposits of an Apollo green glass bead 15401using the ultra-high resolution JEOL 2500 STEM located at NASA Johnson Space Center
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