225 research outputs found
production at the LHC
The search for di-Higgs production at the LHC in order to set limits on Higgs
trilinear coupling and constraints on new physics is one of the main
motivations for the LHC high luminosity phase. Recent experimental analyses
suggest that such analyses will only be successful if information from a range
of channels is included. We therefore investigate di-Higgs production in
association with two hadronic jets and give a detailed discussion of both the
gluon- and weak boson fusion contributions, with a particular emphasis on the
phenomenology with modified Higgs trilinear and quartic gauge couplings. We
perform a detailed investigation of the full hadronic final state and find that
production should add sensitivity to a di-Higgs search combination at
the HL-LHC with 3 ab. Since the WBF and GF contributions are sensitive
to different sources of physics beyond the Standard Model, we devise search
strategies to disentangle and isolate these production modes. While gluon
fusion remains non-negligible in WBF-type selections, sizeable new physics
contributions to the latter can still be constrained. As an example of the
latter point we investigate the sensitivity that can be obtained for a
measurement of the quartic Higgs-gauge boson couplings.Comment: 11 pages, 9 figure
Unboxed data constructors -- or, how cpp decides a halting problem
We propose a new language feature for ML-family languages, the ability to
selectively *unbox* certain data constructors, so that their runtime
representation gets compiled away to just the identity on their argument.
Unboxing must be statically rejected when it could introduce *confusions*,
that is, distinct values with the same representation.
We discuss the use-case of big numbers, where unboxing allows to write code
that is both efficient and safe, replacing either a safe but slow version or a
fast but unsafe version.
We explain the static analysis necessary to reject incorrect unboxing
requests.
We present our prototype implementation of this feature for the OCaml
programming language, discuss several design choices and the interaction with
advanced features such as Guarded Algebraic Datatypes.
Our static analysis requires expanding type definitions in type expressions,
which is not necessarily normalizing in presence of recursive type definitions.
In other words, we must decide normalization of terms in the first-order
lambda-calculus with recursion. We provide an algorithm to detect
non-termination on-the-fly during reduction, with proofs of correctness and
completeness.
Our termination-monitoring algorithm turns out to be closely related to the
normalization strategy for macro expansion in the `cpp` preprocessor.Comment: Author version, to appear at POPL 202
Decoding cognition from spontaneous neural activity
In human neuroscience, studies of cognition are rarely grounded in non-task-evoked, ‘spontaneous’ neural activity. Indeed, studies of spontaneous activity tend to focus predominantly on intrinsic neural patterns (for example, resting-state networks). Taking a ‘representation-rich’ approach bridges the gap between cognition and resting-state communities: this approach relies on decoding task-related representations from spontaneous neural activity, allowing quantification of the representational content and rich dynamics of such activity. For example, if we know the neural representation of an episodic memory, we can decode its subsequent replay during rest. We argue that such an approach advances cognitive research beyond a focus on immediate task demand and provides insight into the functional relevance of the intrinsic neural pattern (for example, the default mode network). This in turn enables a greater integration between human and animal neuroscience, facilitating experimental testing of theoretical accounts of intrinsic activity, and opening new avenues of research in psychiatry
The host with the most? The effects of the Olympic Games on happiness
We show that hosting the Olympic Games in 2012 had a positive impact on the life satisfaction and happiness of Londoners during the Games, compared to residents of Paris and Berlin. Notwithstanding issues of causal inference, the magnitude of the effects is equivalent to moving from the bottom to the fourth income decile. But they do not last very long: the effects are gone within a year. These conclusions are based on a novel panel survey of 26,000 individuals who were interviewed during the summers of 2011, 2012, and 2013, i.e. before, during, and after the event. The results are robust to selection into the survey and to the number of medals won
Systemic interferon type I and B cell responses are impaired in autoimmune polyendocrine syndrome type 1
Autoimmune polyendocrine syndrome type I (APS-1) is caused by mutations in the autoimmune regulator (AIRE) gene and characterised clinically by multiple autoimmune manifestations and serologically by autoantibodies against tissue proteins and cytokines. We here hypothesised that lack of AIRE expression in thymus affects blood immune cells and performed whole-blood microarray analysis (N = 16 APS-I patients vs 16 controls), qPCR verification, and bioinformatic deconvolution of cell subsets. We identified B cell responses as being downregulated in APS-1 patients, which was confirmed by qPCR; these results call for further studies on B cells in this disorder. The type I interferon (IFN-I) pathway was also downregulated in APS-1, and the presence of IFN antibodies is the likely reason for this mild overall downregulation of the IFN-I genes in most APS-1 patients.publishedVersio
Incidence of primary hepatitis C infection and risk factors for transmission in an Australian prisoner cohort
Background. Hepatitis C virus (HCV) infection is common in prisoner populations, particularly those with a history of injecting drug use (IDU). Previous studies of HCV incidence have been based on small case numbers and have not distinguished risk event
Naomi: a new modelling tool for estimating HIV epidemic indicators at the district level in sub-Saharan Africa.
INTRODUCTION: HIV planning requires granular estimates for the number of people living with HIV (PLHIV), antiretroviral treatment (ART) coverage and unmet need, and new HIV infections by district, or equivalent subnational administrative level. We developed a Bayesian small-area estimation model, called Naomi, to estimate these quantities stratified by subnational administrative units, sex, and five-year age groups. METHODS: Small-area regressions for HIV prevalence, ART coverage and HIV incidence were jointly calibrated using subnational household survey data on all three indicators, routine antenatal service delivery data on HIV prevalence and ART coverage among pregnant women, and service delivery data on the number of PLHIV receiving ART. Incidence was modelled by district-level HIV prevalence and ART coverage. Model outputs of counts and rates for each indicator were aggregated to multiple geographic and demographic stratifications of interest. The model was estimated in an empirical Bayes framework, furnishing probabilistic uncertainty ranges for all output indicators. Example results were presented using data from Malawi during 2016-2018. RESULTS: Adult HIV prevalence in September 2018 ranged from 3.2% to 17.1% across Malawi's districts and was higher in southern districts and in metropolitan areas. ART coverage was more homogenous, ranging from 75% to 82%. The largest number of PLHIV was among ages 35 to 39 for both women and men, while the most untreated PLHIV were among ages 25 to 29 for women and 30 to 34 for men. Relative uncertainty was larger for the untreated PLHIV than the number on ART or total PLHIV. Among clients receiving ART at facilities in Lilongwe city, an estimated 71% (95% CI, 61% to 79%) resided in Lilongwe city, 20% (14% to 27%) in Lilongwe district outside the metropolis, and 9% (6% to 12%) in neighbouring Dowa district. Thirty-eight percent (26% to 50%) of Lilongwe rural residents and 39% (27% to 50%) of Dowa residents received treatment at facilities in Lilongwe city. CONCLUSIONS: The Naomi model synthesizes multiple subnational data sources to furnish estimates of key indicators for HIV programme planning, resource allocation, and target setting. Further model development to meet evolving HIV policy priorities and programme need should be accompanied by continued strengthening and understanding of routine health system data
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