7,103 research outputs found
CP violation in 2HDM and EFT: the ZZZ vertex
We study the CP violating ZZZ vertex in the two-Higgs doublet model, which is
a probe of a Jarlskog-type invariant in the extended Higgs sector. The form
factor is evaluated at one loop in a general gauge and its
magnitude is estimated in the realistic parameter space. Then we turn to the
decoupling limit of the two-Higgs doublet model, where the extra scalars are
heavy and the physics can be described by the Standard Model supplemented by
higher-dimensional operators. The leading operator contributing to at
one loop is identified. The CP violating ZZZ vertex is not generated in the
effective theory by dimension-8 operators, but instead arises only at the
dimension-12 level, which implies an additional suppression by powers of the
heavy Higgs mass scale.Comment: 21 pages; v2: added references and comments, appendix A on method of
regions, and appendix B on derivation of CP-violating effective Lagrangian.
Corrected discussion of dimension-12 operators contributing to ZZZ vertex.
Final JHEP versio
Performance Bounds for Grouped Incoherent Measurements in Compressive Sensing
Compressive sensing (CS) allows for acquisition of sparse signals at sampling
rates significantly lower than the Nyquist rate required for bandlimited
signals. Recovery guarantees for CS are generally derived based on the
assumption that measurement projections are selected independently at random.
However, for many practical signal acquisition applications, including medical
imaging and remote sensing, this assumption is violated as the projections must
be taken in groups. In this paper, we consider such applications and derive
requirements on the number of measurements needed for successful recovery of
signals when groups of dependent projections are taken at random. We find a
penalty factor on the number of required measurements with respect to the
standard CS scheme that employs conventional independent measurement selection
and evaluate the accuracy of the predicted penalty through simulations.Comment: Revised for publication. 21 pages, 10 figure
Protein interface classification by evolutionary analysis
Background
Distinguishing biologically relevant interfaces from lattice contacts in protein crystals is a fundamental problem in structural biology. Despite efforts towards the computational prediction of interface character, many issues are still unresolved.
Results
We present here a protein-protein interface classifier that relies on evolutionary data to detect the biological character of interfaces. The classifier uses a simple geometric measure, number of core residues, and two evolutionary indicators based on the sequence entropy of homolog sequences. Both aim at detecting differential selection pressure between interface core and rim or rest of surface. The core residues, defined as fully buried residues (>95% burial), appear to be fundamental determinants of biological interfaces: their number is in itself a powerful discriminator of interface character and together with the evolutionary measures it is able to clearly distinguish evolved biological contacts from crystal ones. We demonstrate that this definition of core residues leads to distinctively better results than earlier definitions from the literature. The stringent selection and quality filtering of structural and sequence data was key to the success of the method. Most importantly we demonstrate that a more conservative selection of homolog sequences - with relatively high sequence identities to the query - is able to produce a clearer signal than previous attempts.
Conclusions
An evolutionary approach like the one presented here is key to the advancement of the field, which so far was missing an effective method exploiting the evolutionary character of protein interfaces. Its coverage and performance will only improve over time thanks to the incessant growth of sequence databases. Currently our method reaches an accuracy of 89% in classifying interfaces of the Ponstingl 2003 datasets and it lends itself to a variety of useful applications in structural biology and bioinformatics. We made the corresponding software implementation available to the community as an easy-to-use graphical web interface at http://www.eppic-web.org.ISSN:1471-210
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Symptoms of mood disorders in family carers of older people with dementia who experience caregiver burden: a network approach
Background: Informal carers of people with dementia are at greater risk of anxiety and depressive disorders if they find caregiving to be a burden. The aim of this study was to use a network analysis of cross-sectional data to investigate the relationships between anxiety and depressive symptoms in family carers of older people with dementia who experience burden. Methods: Sixty family carers exhibiting high levels of burden using the Zarit Burden Interview were included in the study. Participants completed the Hospital Anxiety and Depression Scale.The network analysis identified the depression and anxiety symptom network using features including a topological graph, network centrality metrics and community analysis. The network was estimated through the graphical LASSO technique in combination with a walktrap algorithm to obtain the clusters within the network and the connections between the nodes (symptoms). A directed acyclic graph was generated to model symptom interactions. Results: The resulting network architecture shows important bridges between depression and anxiety symptoms. Lack of pleasure and loss of enjoyment were identified as potential gateway symptoms to other anxiety and depression symptoms and represent possible therapeutic targets for psychosocial interventions. Fear and loss of optimism were highly central symptoms, indicating their importance as warning signs of more generalised anxiety and depression. Conclusions: This network analysis of depressive and anxiety symptoms in overburdened family carers provides important insights as to what symptoms may be the most important targets for behavioural interventions
Optimization of termite in-ground monitoring stations: An evaluation trial
Subterranean termites are serious pests of wood in service in much of the world. One of the most popular techniques for monitoring and controlling termites is the use of in-ground monitoring stations. Different cellulosic matrices were evaluated in terms of mass loss, moisture content variation andtermite presence, accounting for spatial coordinates and monitoring station conditional variables, including: type of cellulosic matrix, matrix treatment and meteorological conditions, during one year in field conditions, both in Portugal and in the USA. A multivariate redundancy analysis wasperformed resulting in 60.4% of data variability being explained by the variables considered in this analysis. Spatial variables were responsible for the highest amount of variance observed in the response variables monitored for the termite monitoring stations, followed by the type of cellulosic matrix,from which cellulose and Hevea brasiliensis were the most influential variables. The optimization of termite in-ground monitoring stations should be performed through correct evaluation of termite feeding preferences and decay resistance, in order to choose an adequate bait matrix and a proper baitdesign. The termite species biology and the geographical location where control programs will be applied should also be taken into account
Systematic Observation of Corner Kick Strategies in Portuguese Football Players
Set pieces are important for the success of football teams, with the corner kick being one of the most game defining events. The aim of this research was twofold: (1) to analyze the corner kicks of a senior football amateur team, and (2) to compare the corner kicks of successful and unsuccessful teams (of the 2020/21 sporting season). In total, 500 corners were observed using a bespoke notational analysis tool, using a specific observational instrument tool (8 criteria; 25 categories). Out of the 500 corner kicks, 6% resulted in a goal. A greater number of direct corners using inswing trajectories were performed (n = 54%). Corners were delivered to central and front post areas most frequently (n = 79%). Five attackers were most predominantly used for offensive corners (n = 58%), but defenders won the ball more frequently (n = 44%). Attempts at goal occurred following a corner most commonly from outside of the box (n = 7%). Goals were scored most frequently with the foot (n = 16%) and head (n = 15%). Successful teams are more effective at reaching the attackers and score more goals directly from corners. Unsuccessful teams deliver more corner kicks out of play, the first touch is more frequently from the opposition defenders, and fewe goals are scored from corner kicks. The study provides an insight into the determining factors and patterns that influence corner kicks and success in football matches. This information should be used by coaches to prepare teams for both offensive and defensive corner kicks to increase team success and match outcomes.info:eu-repo/semantics/publishedVersio
Physical fitness spurts in pre-adolescent boys and girls: Timing, intensity and sequencing
We aim to (1) estimate age of attainment of the peak mid-growth spurt in stature (age-at-peak MGS) in
pre-adolescent boys and girls; (2) identify the timing, intensity, and sequences of physical fitness (PF)
spurts aligned by the age-at-peak MGS; and (3) identify any sex differences in PF spurts aligned by age-at peak MGS. The sample included 180 Portuguese children (90 girls) aged 6 to 10 years at study entry who
were followed annually for 4 years. Height, health-, and performance-related PF were assessed. Age-at peak MGS and PF spurts were estimated using a non-smooth mathematical procedure. Boysâ and girlsâ
age-at-peak MGS occurred at 7.8 ± 0.47 years and 8.0 ± 0.72 years, respectively. PF spurtsâ timing aligned
by age-at-peak MGS were as follows: (1) before age-at-peak MGS: boys â static strength, aerobic capacity,
explosive leg strength, and flexibility; girls â speed, agility, aerobic capacity, and upper body strength; (2)
coincident with age-at-peak MGS: girls â explosive leg strength and flexibility; (3) after age-at-peak MGS:
boys â abdominal strength, upper body strength, agility, and speed; girls â abdominal strength and static
strength. Boys and girls attained their MGS at relatively similar ages. However, the timing and sequences
of PF spurts, aligned on age-at-MGS, were different between boys and girls.info:eu-repo/semantics/publishedVersio
Ocean acidification during the early Toarcian extinction event : evidence from boron isotopes in brachiopods
This project was funded by the European Unionâs Horizon 2020 research and innovation program under the Marie SkĆodowska-Curie grant agreement and project BASE-LiNE Earth (643084) and by the Slovak Research and Development Agency (APVV17-0555) and the Slovak Scientific Grant Agency (VEGA 0169/19).The loss of carbonate production during the Toarcian Oceanic Anoxic Event (T-OAE, ca.183 Ma) is hypothesized to have been at least partly triggered by ocean acidification linkedto magmatism from the Karoo-Ferrar large igneous province (southern Africa and Antarctica).However, the dynamics of acidification have never been directly quantified across theT-OAE. Here, we present the first record of temporal evolution of seawater pH spanning thelate Pliensbachian and early Toarcian from the Lusitanian Basin (Portugal) reconstructedon the basis of boron isotopic composition (ÎŽ11B) of brachiopod shells. ÎŽ11B declines by ~1â°across the Pliensbachian-Toarcian boundary (Pl-To) and attains the lowest values (~12.5â°)just prior to and within the T-OAE, followed by fluctuations and a moderately increasingtrend afterwards. The decline in ÎŽ11B coincides with decreasing bulk CaCO3 content, inparallel with the two-phase decline in carbonate production observed at global scales andwith changes in pCO2 derived from stomatal indices. Seawater pH had declined significantlyalready prior to the T-OAE, probably due to the repeated emissions of volcanogenicCO2. During the earliest phase of the T-OAE, pH increased for a short period, likely dueto intensified continental weathering and organic carbon burial, resulting in atmosphericCO2 drawdown. Subsequently, pH dropped again, reaching the minimum in the middle ofthe T-OAE. The early Toarcian marine extinction and carbonate collapse were thus driven,in part, by ocean acidification, similar to other Phanerozoic events caused by major CO2 emissions and warming.Publisher PDFPeer reviewe
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