How degenerate can cosmological neutrinos be?

There are well-known bounds on light neutrino masses from cosmological energy density arguments. These arguments assume the neutrinos to be non-degenerate. We show how these bounds are affected if the neutrinos are degenerate. In this case, we obtain correlated bounds between neutrino mass and degeneracy.Comment: 5 pages, Latex, uses epsf.sty. (Some details added at the referee's request. One reference added.

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe

Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at root s(NN)=2.76TeV

The elliptic flow, v(2), of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4) is measured in Pb-Pb collisions at root s(NN)= 2.76TeVwith the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v(2) of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, p(T), is studied in the interval 3 <p(T)<10 GeV/c. A positive v(2) is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10-20% and 20-40% centrality classes) for the p(T) interval from 3 to about 5GeV/c with a significance larger than 3 sigma, based on the combination of statistical and systematic uncertainties. The v(2) magnitude tends to decrease towards more central collisions and with increasing pT. It becomes compatible with zero in the interval 6 <p(T)<10 GeV/c. The results are compared to models describing the interaction of heavy quarks and open heavy-flavour hadrons with the high-density medium formed in high-energy heavy-ion collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

Pseudorapidity and transverse-momentum distributions of charged particles in proton-proton collisions at root s=13 TeV

The pseudorapidity (eta) and transverse-momentum (p(T)) distributions of charged particles produced in proton-proton collisions are measured at the centre-of-mass energy root s = 13 TeV. The pseudorapidity distribution in vertical bar eta vertical bar <1.8 is reported for inelastic events and for events with at least one charged particle in vertical bar eta vertical bar <1. The pseudorapidity density of charged particles produced in the pseudorapidity region vertical bar eta vertical bar <0.5 is 5.31 +/- 0.18 and 6.46 +/- 0.19 for the two event classes, respectively. The transverse-momentum distribution of charged particles is measured in the range 0.15 <p(T) <20 GeV/c and vertical bar eta vertical bar <0.8 for events with at least one charged particle in vertical bar eta vertical bar <1. The evolution of the transverse momentum spectra of charged particles is also investigated as a function of event multiplicity. The results are compared with calculations from PYTHIA and EPOS Monte Carlo generators. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Hyperglycaemia in the critically ill patient: ideal treatment and impact of the condition

This thesis is composed of four distinct related chapters focusing on glycaemia in the intensive care unit (ICU), its treatment, and the impact of the condition. Specifically, this research concentrates on approaches to glycaemic management, enteral feeding, and implications of hyperglycaemia in the critically ill. The work submitted comprises three literature reviews and five original studies. In the critically ill, delayed gastric emptying occurs frequently and is associated with adverse outcomes. Numerous techniques to quantify gastric emptying exist (Chapter 1.2). Energy dense feeds are sometimes administered to patients with delayed gastric emptying based on the rationale that volume is a determinant of gastric emptying. However, in health, tight regulation of gastric emptying occurs via ‘enterogastric feedback’, such that it is calorie load (not volume) that is the major determinant of gastric emptying. An analysis of previously obtained data suggested energy dense feed is associated with a slower emptying rate than a standard feed, resulting in similar caloric delivery (Chapter 1.3). Hyperglycaemia occurs frequently during critical illness in patients with pre-existing diabetes. The current approach to treatment of glycaemia in this group is to treat them identical to patients without diabetes. This strategy may be flawed as observational data suggest that the impact of acute glycaemia on outcomes is dependent on premorbid glycaemia (Chapter 2.2). To provide further information, a prospective sequential period pilot study was completed (Chapter 2.3). This study suggests that a more liberal approach may reduce hypoglycaemia episodes and that further trials of more liberal glucose targets are warranted. The treatment of hyperglycaemia during critical illness (for both patients with and without pre-existing diabetes) requires administration of insulin; however, this is not without risk. Therefore a prospective, randomised, cross over study in critically ill patients to determine the effect of glucose-dependent insulinotropic polypeptide (GIP) was performed. The administration of GIP in pharmacological doses when compared to placebo did not effect glycaemia, glucose absorption or gastric emptying (Chapter 2.4). Stress hyperglycaemia occurs frequently in critically ill patients but is not generally considered a risk factor for subsequent glucose intolerance. A systematic review and meta-analysis was conducted suggesting stress hyperglycaemia was associated with an increased risk of both prediabetes and diabetes (Chapter 3.2). Subsequently, a prospective cohort study was performed confirming this signal and providing mechanistic information regarding the progression to prediabetes and diabetes (Chapter 3.3). Patients during and recovering from critical illness as well as ambulant patients with diabetes frequently experience episodes of hypoglycaemia. The counter-regulatory response to hypoglycaemia is to accelerate gastric emptying, increasing carbohydrate absorption from the small intestine. A study was performed to understand whether recurrent episodes of hypoglycaemia diminish the standard counter-regulatory response (Chapter 4.2). In healthy volunteers, the acceleration of gastric emptying during acute hypoglycaemia in health did not appear to be affected by antecedent hypoglycaemia. In summary, this program of work has contributed new and important information in the fields of diabetes management, feeding in the critical care setting, and the implications of stress hyperglycaemia in the critically ill.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 201