2,608 research outputs found
Future prospects for exploring present day anomalies in flavour physics measurements with Belle II and LHCb
A range of flavour physics observables show tensions with their corresponding
Standard Model expectations: measurements of leptonic flavour-changing neutral
current processes and ratios of semi-leptonic branching fractions involving
different generations of leptons show deviations of the order of four standard
deviations. If confirmed, either would be an intriguing sign of new physics. In
this manuscript, we analyse the current experimental situation of such
processes and for the first time estimate the combined impact of the future
datasets of the Belle II and LHCb experiments on the present tensions with the
Standard Model expectations by performing scans of the new physics contribution
to the Wilson coefficients. In addition, the present day and future sensitivity
of tree-level CKM parameters, which offer orthogonal tests of the Standard
Model, are explored. Three benchmark points in time are chosen for a direct
comparison of the estimated sensitivity between the experiments. A high
complementarity between the future sensitivity achieved by the Belle II and
LHCb experiments is observed due to their relative strengths and weaknesses. We
estimate that all of the anomalies considered here will be either confirmed or
ruled out by both experiments independently with very high significance by the
end of data-taking at Belle II and the LHCb upgrade
A Face-On Tully-Fisher Relation
We construct the first "face-on" Tully-Fisher (TF) relation for 24 galaxies
with inclinations between 16 degrees and 41 degrees. The enabling measurements
are integral-field, echelle spectroscopy from the WIYN 3.5m telescope, which
yield accurate kinematic estimates of disk inclination to 15 degrees. Kinematic
inclinations are of sufficient accuracy that our measured TF scatter of 0.42
mag is comparable to other surveys even without internal-absorption
corrections. Three of four galaxies with significant kinematic and photometric
asymmetries also have the largest deviations from our TF relation, suggesting
that asymmetries make an important contribution to TF scatter. By measuring
inclinations below 40 degrees, we establish a direct path to linking this
scatter to the unprojected structure of disks and making non-degenerate
dynamical mass-decompositions of spiral galaxies.Comment: 13 pages, 3 figures (2 color). Accepted for publication in ApJ
Letter
The Tully-Fisher Relation of Barred Galaxies
We present new data exploring the scaling relations, such as the Tully-Fisher
relation (TFR), of bright barred and unbarred galaxies. A primary motivation
for this study is to establish whether barredness correlates with, and is a
consequence of, virial properties of galaxies. Various lines of evidence
suggest that dark matter is dominant in disks of bright unbarred galaxies at
2.2 disk scale lengths, the point of peak rotation for a pure exponential disk.
We test the hypothesis that the TF plane of barred high surface brightness
galaxies is offset from the mean TFR of unbarred galaxies, as might be expected
if barred galaxies are ``maximal'' in their inner parts. We use existing and
new TF data to search for basic structural differences between barred and
unbarred galaxies. Our new data consist of 2-dimensional Halpha velocity fields
derived from SparsePak integral field spectroscopy (IFS) and V,I-band CCD
images collected at the WIYN Observatory for 14 strongly barred galaxies. We
use WIYN/SparsePak (2-D) velocity fields to show that long-slit (1-D) spectra
yield reliable circular speed measurements at or beyond 2.2 disk scale lengths,
far from any influence of the bar. This enables us to consider line width
measurements from extensive TF surveys which include barred and nonbarred disks
and derive detailed scaling relation comparisons. We find that for a given
luminosity, barred and unbarred galaxies have comparable structural and
dynamical parameters, such as peak velocities, scale lengths, or colors. In
particular, the location of a galaxy in the TF plane is independent of
barredness. In a global dynamical sense, barred and unbarred galaxies behave
similarly and are likely to have, on average, comparable fractions of luminous
and dark matter at a given radius. (abridged)Comment: Accepted for publication in the ApJ (September 1, 2003 issue, v594).
Appendix figures with I-band image and superimposed 2-D velocity field plus
rotation curves must be downloaded separately (due to size constraints) from
http://www.astro.ubc.ca/people/courteau/public/courteau03_TFbars.ps.g
Tea, talk and technology: patient and public involvement to improve connected health âwearablesâ research in dementia
Plain English summary There are a growing number of mobile phones, watches and electronic devices which can be worn on the body to track aspects of health and well-being, such as daily steps, sleep and exercise. Dementia researchers think that these devices could potentially be used as part of future research projects, for example to help spot changes in daily activity that may signal the early symptoms of dementia. We asked a range of older people, including people living with dementia and their carers, to participate in interactive discussions about how future participants might find using these devices as part of research projects. We also invited volunteers to borrow a range of devices to test at home, giving them further insights. Discussions revealed that people were generally supportive of this type of research, provided they gave informed consent and that devices were discreet, comfortable and easy to use. They also valued technical support and regular feedback on study progress to encourage ongoing participation. These findings were used to develop a pool of devices for researchers, with computer software and written guidance to help plan, design and support studies. Our work shows that when given the right opportunities, people who are affected by dementia can provide valuable insights that can enhance the design, delivery and quality of future research. Abstract Background Increasingly, researchers are recognising the potential for connected health devices, including smartphones and smartwatches, to generate high resolution data about patterns of daily activity and health outcomes. One aim of the Dementias Platform UK (DPUK) project is to provide researchers with a secure means to collect, collate and link data generated by such devices, thereby accelerating this type of research in the field of dementia. We aimed to involve members of the public in discussions about the acceptability and feasibility of different devices and research designs to inform the development of a device pool, software platform and written guidance to support future studies. Methods Over 30 people attended a series of interactive workshops, drop-in sessions and meetings in Greater Manchester. This included people living with dementia and cognitive impairments, carers and people without memory problems. Discussions were tailored to suit different audiences and focused on the feasibility and acceptability of a range of different wearable devices and research designs. We also invited volunteers to borrow a device to test at home, enabling further insights from hands-on interactions with devices. Results Discussions revealed that people were supportive of connected health dementia research in principle, provided they gave informed consent and that devices were discreet, comfortable and easy to use. Moreover, they recommended technical support and regular feedback on study progress to encourage ongoing participation. Conclusion By using a range of discussion-based and practical activities, we found it was feasible to involve people affected by dementia and use their insights to shape the development of a software platform and device pool to support future connected health dementia research. We recommend that researchers planning such studies in future pay adequate attention to designing suitable participant information, technical support and mechanisms of providing study progress updates to support sustained engagement from participants
Mealtime Behaviour and Parent-Child Interaction: A Comparison of Children with Cystic Fibrosis, Children with Feeding Problems, and Nonclinic Controls
Examined the role of family interaction factors in dietary compliance problems reported by parents of children with cystic fibrosis (CF). The family mealtime interactions of children with CF, children with feeding problems and nonclinic controls were observed, and parents monitored children's eating behavior at home. Parents of children with CF reported more concern about feeding problems and recorded more disruptive mealtime behavior than parents of nonclinic children. Observational data showed children with CF to display overall rates of disruptive mealtime behavior not significantly different from either comparison group. Mothers of children with CF were observed to engage in higher rates of aversive interaction with their child than did mothers of nonclinic controls. Fathers of children with CF reported lower marital satisfaction than fathers of controls. Both mothers and fathers of children with CF reported lower parenting self-efficacy than non-CF families. Clinical implications are discussed
The Sloan Digital Sky Survey peculiar velocity catalogue
We present a new catalogue of distances and peculiar velocities (PVs) of 34â059 early-type galaxies derived from fundamental plane (FP) measurements using data from the Sloan Digital Sky Survey (SDSS). This 7016deg2 homogeneous sample comprises the largest set of PVs produced to date and extends the reach of PV surveys up to a redshift limit of z = 0.1. Our SDSS-based FP distance measurements have a mean uncertainty of 23âperâcent. Alongside the data, we produce an ensemble of 2048 mock galaxy catalogues that reproduce the data selection function, and are used to validate our fitting pipelines and check for systematic errors. We uncover a significant trend between group richness and mean surface brightness within the sample, which may hint at an environmental dependence within the FP or the presence of unresolved systematics, and can result in biased PVs. This is removed by using multiple FP fits as function of group richness, a procedure made tractable through a new analytic derivation for the integral of a three-dimensional (3D) Gaussian over non-trivial limits. Our catalogue is calibrated to the zero-point of the CosmicFlows-III sample with an uncertainty of 0.004âdex (not including cosmic variance or the error within CosmicFlows-III itself), which is validated using independent cross-checks with the predicted zero-point from the 2M++ reconstruction of our local velocity field. Finally, as an example of what is possible with our new catalogue, we obtain preliminary bulk flow measurements up to a depth of 135hâ1Mpcâ . We find a slightly larger-than-expected bulk flow at high redshift, although this could be caused by the presence of the Shapley supercluster, which lies outside the SDSS PV footprint
Imaging Carbon Monoxide Emission in the Starburst Galaxy NGC 6000
We present measurements of carbon monoxide emission in the central region of
the nearby starburst NGC 6000 taken with the Submillimeter Array. The J=2-1
transition of 12CO, 13CO, and C18O were imaged at a resolution of ~3''x2''
(450x300 pc). We accurately determine the dynamical center of NGC 6000 at
R.A(J2000.0)=15h49m49.5s and dec(J2000.0)=-29d23'13'' which agrees with the
peak of molecular emission position. The observed CO dynamics could be
explained in the context of the presence of a bar potential affecting the
molecular material, likely responsible for the strong nuclear concentration
where more than 85% of the gas is located. We detect a kinematically detached
component of dense molecular gas at relatively high velocity which might be
fueling the star formation. A total nuclear dynamical mass of 7x10^9 Msun is
derived and a total mass of gas of 4.6x10^8 Msun, yielding a Mgas/Mdyn~6%,
similar to other previously studied barred galaxies with central starbursts. We
determined the mass of molecular gas with the optically thin isotopologue C18O
and we estimate a CO-to-H2 conversion factor X(CO)=0.4x10^20 cm-2/(K km s-1) in
agreement with that determined in other starburst galaxies.Comment: 31 pages, 7 figures. Accepted for publication in Astronomical
Journal
Architecture of the MKK6-p38α complex defines the basis of MAPK specificity and activation
The mitogen-activated protein kinase (MAPK) p38α is a central component of signaling in inflammation and the immune response and is, therefore, an important drug target. Little is known about the molecular mechanism of its activation by double phosphorylation from MAPK kinases (MAP2Ks), because of the challenge of trapping a transient and dynamic heterokinase complex. We applied a multidisciplinary approach to generate a structural model of p38α in complex with its MAP2K, MKK6, and to understand the activation mechanism. Integrating cryo-electron microscopy with molecular dynamics simulations, hydrogen-deuterium exchange mass spectrometry, and experiments in cells, we demonstrate a dynamic, multistep phosphorylation mechanism, identify catalytically relevant interactions, and show that MAP2K-disordered amino termini determine pathway specificity. Our work captures a fundamental step of cell signaling: a kinase phosphorylating its downstream target kinase
The Antarctic ozone hole during 2015 and 2016
We reviewed the 2015 and 2016 Antarctic ozone holes, making use of a variety of ground-based and spacebased measurements of ozone and ultraviolet radiation, supplemented by meteorological reanalyses. The ozone hole of 2015 was one of the most severe on record with respect to maximum area and integrated deficit and was notably longlasting, with many values above previous extremes in October, November and December. In contrast, all assessed metrics for the 2016 ozone hole were at or below their median values for the 37 ozone holes since 1979 for which adequate satellite observations exist. The 2015 ozone hole was influenced both by very cold conditions and enhanced ozone depletion caused by stratospheric aerosol resulting from the April 2015 volcanic eruption of Calbuco (Chile)
The Antarctic ozone hole during 2014
We review the 2014 Antarctic ozone hole, making use of a variety of ground-based and space-based measurements of ozone and ultra-violet radiation, supplemented by meteorological reanalyses. Although the polar vortex was relatively stable in 2014 and persisted some weeks longer into November than was the case in 2012 or 2013, the vortex temperature was close to the long-term mean in September and October with modest warming events occurring in both months, preventing severe depletion from taking place. Of the seven metrics reported here, all were close to their respective median values of the 1979â2014 record, being ranked between 16th and 21st of the 35 years for which adequate satellite observations exist
- âŠ