15,769 research outputs found
Impacts of fuel consumption taxes on mobility patterns and CO2 emissions using a system dynamic approach
Current transport behaviour leads to increasing congestion of the infrastructure, growing dependence on fossil fuels, increasing energy demand, and growing CO2 emissions. Policies based principally on increasing system speed and in particular car speeds will lead to greater urban sprawl with increases in average trip lengths. Time saved by speed increases are traded for more distance. This trend is not sustainable in the longer term. Transport policies based just on time savings for citizens may not be the basis for our city planning strategy. The same happens with transport cost. With underpriced transport, the market undervalues land use location, which again may lead city to sprawl and could induce greater trip lengths. In this study, the efficiency of a fuel consumption or CO2 tax policy is analysed as a policy to internalise externalities of transport in a fair travel cost. Based on system dynamics theory, an integrated land use and transport model is proposed in order to assess the effects and impacts of such policy in the short, medium and long term. Different scenarios related to clean vehicles are incorporated. This model is applied to three cities Madrid, Vienna and Leeds and compares their results
Exclusion and discovery via Drell-Yan in the 4DCHM
Searches for Z' bosons are most sensitive in the dilepton channels at hadron
colliders. Whilst finite width and interference effects do affect the
modifications the presence of BSM physics makes to Standard Model (SM)
contributions, generic searches are often designed to minimize these. The
experimental approach adopted works well in the case of popular models that
predict a single and narrow Z' boson allowing these effects to effectively be
neglected. Conversely, finite width and interference effects may have to be
taken into account in experimental analyses when such Z' states are wide or
where several states are predicted. We explore the consequences of these
effects in the 4-Dimensional Composite Higgs Model (4DCHM) which includes
multiple new Z' bosons and where the decays of these resonances to non-SM
fermions can result in large widths
Interference effects in heavy W'-boson searches at the LHC
Interference effects are widely neglected in searches for new physics. This
is the case in recent publications on searches for W'-bosons using leptonic
final states.
We examine the effects of interference on distributions frequently used to
determine mass limits for possible W'-bosons and show that there are important
qualitative effects on the behaviour of the new physics signal.
There are two main consequences. Firstly, exclusion limits where
interferences effects have not been considered are likely to have been
overestimated. Secondly, presenting experimental results as a function of a
transverse mass cut rather than in terms of the contribution of new physics to
the total cross-section would be more informative.Comment: 31 pages, 8 figures. Published versio
Drell-Yan production of multi Z'-bosons at the LHC within Non-Universal ED and 4D Composite Higgs Models
The Drell-Yan di-lepton production at hadron colliders is by far the
preferred channel to search for new heavy spin-1 particles. Traditionally, such
searches have exploited the Narrow Width Approximation (NWA) for the signal,
thereby neglecting the effect of the interference between the additional
Z'-bosons and the Standard Model Z and {\gamma}. Recently, it has been
established that both finite width and interference effects can be dealt with
in experimental searches while still retaining the model independent approach
ensured by the NWA. This assessment has been made for the case of popular
single Z'-boson models currently probed at the CERN Large Hadron Collider
(LHC). In this paper, we test the scope of the CERN machine in relation to the
above issues for some benchmark multi Z'-boson models. In particular, we
consider Non-Universal Extra Dimensional (NUED) scenarios and the 4-Dimensional
Composite Higgs Model (4DCHM), both predicting a multi-Z' peaking structure. We
conclude that in a variety of cases, specifically those in which the leptonic
decays modes of one or more of the heavy neutral gauge bosons are suppressed
and/or significant interference effects exist between these or with the
background, especially present when their decay widths are significant,
traditional search approaches based on the assumption of rather narrow and
isolated objects might require suitable modifications to extract the underlying
dynamics
Separability properties of higher-rank GBS groups
A rank generalized Baumslag-Solitar group is a group that splits as a
finite graph of groups such that all vertex and edge groups are isomorphic to
. In this paper we classify these groups in terms of their
separability properties. Specifically, we determine when they are residually
finite, subgroup separable and cyclic subgroup separable
Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170 000 participants in 26 randomised trials
Background: Lowering of LDL cholesterol with standard statin regimens reduces the risk of occlusive vascular events in a wide range of individuals. We aimed to assess the safety and efficacy of more intensive lowering of LDL cholesterol with statin therapy. Methods: We undertook meta-analyses of individual participant data from randomised trials involving at least 1000 participants and at least 2 years' treatment duration of more versus less intensive statin regimens (five trials; 39 612 individuals; median follow-up 5·1 years) and of statin versus control (21 trials; 129 526 individuals; median follow-up 4·8 years). For each type of trial, we calculated not only the average risk reduction, but also the average risk reduction per 1·0 mmol/L LDL cholesterol reduction at 1 year after randomisation. Findings: In the trials of more versus less intensive statin therapy, the weighted mean further reduction in LDL cholesterol at 1 year was 0·51 mmol/L. Compared with less intensive regimens, more intensive regimens produced a highly significant 15% (95% CI 11–18; p<0·0001) further reduction in major vascular events, consisting of separately significant reductions in coronary death or non-fatal myocardial infarction of 13% (95% CI 7–19; p<0·0001), in coronary revascularisation of 19% (95% CI 15–24; p<0·0001), and in ischaemic stroke of 16% (95% CI 5–26; p=0·005). Per 1·0 mmol/L reduction in LDL cholesterol, these further reductions in risk were similar to the proportional reductions in the trials of statin versus control. When both types of trial were combined, similar proportional reductions in major vascular events per 1·0 mmol/L LDL cholesterol reduction were found in all types of patient studied (rate ratio [RR] 0·78, 95% CI 0·76–0·80; p<0·0001), including those with LDL cholesterol lower than 2 mmol/L on the less intensive or control regimen. Across all 26 trials, all-cause mortality was reduced by 10% per 1·0 mmol/L LDL reduction (RR 0·90, 95% CI 0·87–0·93; p<0·0001), largely reflecting significant reductions in deaths due to coronary heart disease (RR 0·80, 99% CI 0·74–0·87; p<0·0001) and other cardiac causes (RR 0·89, 99% CI 0·81–0·98; p=0·002), with no significant effect on deaths due to stroke (RR 0·96, 95% CI 0·84–1·09; p=0·5) or other vascular causes (RR 0·98, 99% CI 0·81–1·18; p=0·8). No significant effects were observed on deaths due to cancer or other non-vascular causes (RR 0·97, 95% CI 0·92–1·03; p=0·3) or on cancer incidence (RR 1·00, 95% CI 0·96–1·04; p=0·9), even at low LDL cholesterol concentrations. Interpretation: Further reductions in LDL cholesterol safely produce definite further reductions in the incidence of heart attack, of revascularisation, and of ischaemic stroke, with each 1·0 mmol/L reduction reducing the annual rate of these major vascular events by just over a fifth. There was no evidence of any threshold within the cholesterol range studied, suggesting that reduction of LDL cholesterol by 2–3 mmol/L would reduce risk by about 40–50%
Automorphism groups of positive entropy on minimal projective varieties
We determine the geometric structure of a minimal projective threefold having
two `independent and commutative' automorphisms of positive topological
entropy, and generalize this result to higher-dimensional smooth minimal pairs
(X, G). As a consequence, we give an effective lower bound for the first
dynamical degree of these automorphisms of X fitting the `boundary case'.Comment: Advances in Mathematics (to appear); 11 page
Human–Computer Interaction considerations when developing cyber ranges
The number of cyber-attacks are continuing to rise globally. It is therefore vital for organisations to develop the necessary skills to secure their assets and to protect critical national infrastructure. In this short paper, we outline human-computer interaction elements which should be considered when developing a cybersecurity training platform, in an effort to maintain levels of user engagement. We provide an overview of existing training platforms before covering specialist cyber ranges. Aspects of human-computer interaction are covered with regards to their relevance in the context of cyber ranges. We conclude with design suggestions when developing a cyber range platform
Women\u2019s human rights when experiencing humanitarian crises and conflicts: the impact of United Nations Security Council Resolutions on women, peace, security, and the CEDAW General Recommendation no. 30.
Violence and insecurity are strictly linked to unequal political, social, and economic power. However, the continuity of violence is obscured by masculinist
and patriarchal rules of security within gendered structures, especially inside the division of public/private dimensions and spaces, of production-reproduction activities, and of conflicts of war/peace.
Nowadays, there is a general perception of the gendered dimensions of humanitarian emergencies in public policy outcomes and more in general
in institutional contexts where the central role of women in security and maintaining peace, at all levels of decision making, both prior to, during, and
after the conflict stage, hostilities, and peace-keeping and peace-building stages, as well as in trying to pursue a condition of reconciliation and reconstruction, has been formally recognized at international level.
Nevertheless, it is necessary to focus on some problems related to the conceptualization of and legal provision for \u2018gender based security\u2019 and its
subsequent effects upon accountability, with particular reference to transitional justice and post-conflict societies. It is important to assess a range of contemporary issues implicated for women and security, such as violence and other forms of harassment in times of post-conflict
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