123 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
Do pesticide and pathogen interactions drive wild bee declines?
There is clear evidence for wild insect declines globally. Habitat loss, climate change, pests, pathogens and environmental pollution have all been shown to cause detrimental effects on insects. However, interactive effects between these stressors may be the key to understanding reported declines. Here, we review the literature on pesticide and pathogen interactions for wild bees, identify knowledge gaps, and suggest avenues for future research fostering mitigation of the observed declines. The limited studies available suggest that effects of pesticides most likely override effects of pathogens. Bees feeding on flowers and building sheltered nests, are likely less adapted to toxins compared to other insects, which potential susceptibility is enhanced by the reduced number of genes encoding detoxifying enzymes compared with other insect species. However, to date all 10 studies using a fully-crossed design have been conducted in the laboratory on social bees using Crithidia spp. or Nosema spp., identifying an urgent need to test solitary bees and other pathogens. Similarly, since laboratory studies do not necessarily reflect field conditions, semi-field and field studies are essential if we are to understand these interactions and their potential effects in the real-world. In conclusion, there is a clear need for empirical (semi-)field studies on a range of pesticides, pathogens, and insect species to better understand the pathways and mechanisms underlying their potential interactions, in particular their relevance for insect fitness and population dynamics. Such data are indispensable to drive forward robust modelling of interactive effects in different environmental settings and foster predictive science. This will enable pesticide and pathogen interactions to be put into the context of other stressors more broadly, evaluating their relative importance in driving the observed declines of wild bees and other insects. Ultimately, this will enable the development of more effective mitigation measures to protect bees and the ecosystem services they supply
Indications of suppressed high p_T hadron production in nucleus-nucleus collisions at CERN-SPS
Inclusive pion production at high transverse momenta (p_T > 2 GeV/c) in
nucleus-nucleus (A+A) collisions at CERN SPS (sqrt(s_NN)~20 GeV) is revisited
and systematically compared to all existing proton-proton data in the same
range of center-of-mass energies. The ratio of A+A to p+p pion cross-sections
(nuclear modification factor) for 0-8% central Pb+Pb, Pb+Au and S+Au reactions
does not show a strong enhancement as a function of p_T as previously found,
but is consistent with scaling with the number of nucleon-nucleon (NN)
collisions. Neutral pion yields per NN collision in head-on Pb+Pb reactions are
suppressed, whereas peripheral yields are enhanced. These results together
indicate that some amount of ``jet quenching'' may already be present in
central heavy-ion reactions at sqrt(s_NN)~20 GeV.Comment: Updated versions of Figs. 1,2 and 4. Minor text modification
Performance measures of net-enabled hypercompetitive industries: the case of tourism
This paper investigates the theory and practise of e-metrics. It examines the tourism sector as one of the most successful sectors on-line and identifies best practice in the industry. Qualitative research with top e-Marketing executives demonstrates the usage and satisfaction levels from current e-metrics deployment, selection of e-metrics for ROI calculation as well as intention of new e-metrics implementation and future trends and developments. This paper concludes that tourism organizations gradually realise the value of e-measurement and are willing to implement e-metrics to enable them evaluate the effectiveness of their planning processes and assess their results against their short and the long term objectives
Physics Results from RICH Detectors
RICH detectors have become extraordinarily useful. Results include
measurement of solar neutrino rates, evidence for neutrino oscillations,
measurement of TeV gamma-rays from gravitational sources, properties of QCD,
charm production and decay, and measurement of the CKM matrix elements Vcs, Vcb
and Vub. A new value |Vub/Vcb|=0.087+/-0.012 is determined.Comment: Invited talk at ``The 3rd International Workshop on Ring Imaging
Cherenkov Detectors," Ein-Gedi, Dead-Sea, Israel, Nov. 15-20, 1998, 21 pages,
22 fig
Intra-articular injections of high-molecular-weight hyaluronic acid have biphasic effects on joint inflammation and destruction in rat antigen-induced arthritis
To assess the potential use of hyaluronic acid (HA) as adjuvant therapy in rheumatoid arthritis, the anti-inflammatory and chondroprotective effects of HA were analysed in experimental rat antigen-induced arthritis (AIA). Lewis rats with AIA were subjected to short-term (days 1 and 8, n = 10) or long-term (days 1, 8, 15 and 22, n = 10) intra-articular treatment with microbially manufactured, high-molecular-weight HA (molecular weight, 1.7 Ă— 10(6 )Da; 0.5 mg/dose). In both tests, 10 buffer-treated AIA rats served as arthritic controls and six healthy animals served as normal controls. Arthritis was monitored by weekly assessment of joint swelling and histological evaluation in the short-term test (day 8) and in the long-term test (day 29). Safranin O staining was employed to detect proteoglycan loss from the epiphyseal growth plate and the articular cartilage of the arthritic knee joint. Serum levels of IL-6, tumour necrosis factor alpha and glycosaminoglycans were measured by ELISA/kit systems (days 8 and 29). HA treatment did not significantly influence AIA in the short-term test (days 1 and 8) but did suppress early chronic AIA (day 15, P < 0.05); however, HA treatment tended to aggravate chronic AIA in the long-term test (day 29). HA completely prevented proteoglycan loss from the epiphyseal growth plate and articular cartilage on day 8, but induced proteoglycan loss from the epiphyseal growth plate on day 29. Similarly, HA inhibited the histological signs of acute inflammation and cartilage damage in the short-term test, but augmented acute and chronic inflammation as well as cartilage damage in the long-term test. Serum levels of IL-6, tumour necrosis factor alpha, and glycosaminoglycans were not influenced by HA. Local therapeutic effects of HA in AIA are clearly biphasic, with inhibition of inflammation and cartilage damage in the early chronic phase but with promotion of joint swelling, inflammation and cartilage damage in the late chronic phase
SUSY GUTs with Yukawa unification: a go/no-go study using FCNC processes
We address the viability of exact Yukawa unification in the context of
general SUSY GUTs with universal soft-breaking sfermion and gaugino mass terms
at the GUT scale. We find that this possibility is challenged, unless the
squark spectrum is pushed well above the limits allowed by naturalness. This
conclusion is assessed through a global fit using electroweak observables and
quark flavour-changing neutral current (FCNC) processes. The problem is mostly
the impossibility of accommodating simultaneously the bottom mass and the BR(B
--> Xs gamma), after the stringent CDF upper bound on the decay Bs --> mu^+
mu^- is taken into account, and under the basic assumption that the b --> s
gamma amplitude have like sign with respect to the Standard Model one, as
indicated by the B --> Xs l^+ l^- data.
With the same strategy, we also consider the possibility of relaxing Yukawa
unification to b - tau Yukawa unification. We find that with small departures
from the condition tan beta ~= 50, holding when Yukawa unification is exact,
the mentioned tension is substantially relieved. We emphasize that in the
region where fits are successful the lightest part of the SUSY spectrum is
basically fixed by the requirements of b - tau unification and the applied FCNC
constraints. As such, it is easily falsifiable once the LHC turns on.Comment: 10 pages, 1 figure, 5 tables. v3: A few textual modifications.
Conclusions unchanged. Matches journal versio
Gauged flavour symmetry for the light generations
We study the phenomenology of a model where an SU(2)^3 flavour symmetry
acting on the first two generation quarks is gauged and Yukawa couplings for
the light generations are generated by a see-saw mechanism involving heavy
fermions needed to cancel flavour-gauge anomalies. We find that, in constrast
to the SU(3)^3 case studied in the literature, most of the constraints related
to the third generation, like electroweak precision bounds or B physics
observables, can be evaded, while characteristic collider signatures are
predicted.Comment: 16 pages, 3 figure
Challenging SO(10) SUSY GUTs with family symmetries through FCNC processes
We perform a detailed analysis of the SO(10) SUSY GUT model with D3 family
symmetry of Dermisek and Raby (DR). The model is specified in terms of 24
parameters and predicts, as a function of them, the whole MSSM set of
parameters at low energy scales. Concerning the SM subset of such parameters,
the model is able to give a satisfactory description of the quark and lepton
masses, of the PMNS matrix and of the CKM matrix. We perform a global fit to
the model, including flavour changing neutral current (FCNC) processes Bs -->
mu+ mu-, B --> Xs gamma, B --> Xs l+ l- and the B(d,s) - bar B(d,s) mass
differences Delta M(d,s) as well as the flavour changing (FC) process B+ -->
tau+ nu. These observables provide at present the most sensitive probe of the
SUSY mass spectrum and couplings predicted by the model. Our analysis
demonstrates that the simultaneous description of the FC observables in
question represents a serious challenge for the DR model, unless the masses of
the scalars are moved to regions which are problematic from the point of view
of naturalness and probably beyond the reach of the LHC. We emphasize that this
problem could be a general feature of SUSY GUT models with third generation
Yukawa unification and weak-scale minimal flavour violation.Comment: 1 + 37 pages, 5 figures, 11 tables. v3: minor typos fixed. Matches
JHEP published versio
Multiclass prediction of different dementia syndromes based on multi-centric volumetric MRI imaging
IntroductionDementia syndromes can be difficult to diagnose. We aimed at building a classifier for multiple dementia syndromes using magnetic resonance imaging (MRI).MethodsAtlas-based volumetry was performed on T1-weighted MRI data of 426 patients and 51 controls from the multi-centric German Research Consortium of Frontotemporal Lobar Degeneration including patients with behavioral variant frontotemporal dementia, Alzheimer’s disease, the three subtypes of primary progressive aphasia, i.e., semantic, logopenic and nonfluent-agrammatic variant, and the atypical parkinsonian syndromes progressive supranuclear palsy and corticobasal syndrome. Support vector machine classification was used to classify each patient group against controls (binary classification) and all seven diagnostic groups against each other in a multi-syndrome classifier (multiclass classification).ResultsThe binary classification models reached high prediction accuracies between 71 and 95% with a chance level of 50%. Feature importance reflected disease-specific atrophy patterns. The multi-syndrome model reached accuracies of more than three times higher than chance level but was far from 100%. Multi-syndrome model performance was not homogenous across dementia syndromes, with better performance in syndromes characterized by regionally specific atrophy patterns. Whereas diseases generally could be classified vs controls more correctly with increasing severity and duration, differentiation between diseases was optimal in disease-specific windows of severity and duration.DiscussionResults suggest that automated methods applied to MR imaging data can support physicians in diagnosis of dementia syndromes. It is particularly relevant for orphan diseases beside frequent syndromes such as Alzheimer’s disease
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