Three-Particle Azimuthal Correlations

Two-particle azimuthal correlations in central Au+Au collisional at RHIC have revealed a broadened away-side structure, with respect to perpherial Au+Au, pp, and d+Au. This could be explained by different physics mechanisms such as: large angle gluon radiation, deflected jets, Cerenkov gluon radiation, and conical flow generated by hydrodynamic shock-waves. We can discriminate the scenarios with conical emission, Cerenkov radiation and conical flow, from the other mechanisms though three-particle correlations. In addition, the associated particle pT dependence can be used to distinguish conical flow from simple Cerenkov gluon radiation. We will discuss three-particle correlation analyses that have been performed at RHIC and what can be done at the LHC.Comment: Talk given at 'High p_T physics at the LHC', Jyvaskyla, Finland, March 200

Analysis Method for Jet-Like Three-Particle Azimuthal Correlations

Jet-like three-particle azimuthal correlations can discriminate various physical scenarios that have been proposed to explain the observed strong modification to two-particle azimuthal correlations. The three-particle correlation analysis is notoriously difficult in heavy-ion collisions due to the large combinatoric backgrounds. We describe the general idea behind the jet-like three-particle azimuthal correlation analysis, with emphasis put on the subtraction of the combinatoric backgrounds. We discuss in detail the various systematic effects in such an analysis.Comment: This is the final published version in NIM

Antibiotic prophylaxis is associated with subsequent resistant infections in children with an initial extended-spectrum-cephalosporin-resistant Enterobacteriaceae infection

ABSTRACT The objective of this study was to assess the association between previous antibiotic use, particularly long-term prophylaxis, and the occurrence of subsequent resistant infections in children with index infections due to extended-spectrum-cephalosporin-resistant Enterobacteriaceae . We also investigated the concordance of the index and subsequent isolates. Extended-spectrum-cephalosporin-resistant Escherichia coli and Klebsiella spp. isolated from normally sterile sites of patients aged &lt;22 years were collected along with associated clinical data from four freestanding pediatric centers. Subsequent isolates were categorized as concordant if the species, resistance determinants, and fumC-fimH ( E. coli ) or tonB ( Klebsiella pneumoniae ) type were identical to those of the index isolate. In total, 323 patients had 396 resistant isolates; 45 (14%) patients had ≥1 subsequent resistant infection, totaling 73 subsequent resistant isolates. The median time between the index and first subsequent infections was 123 (interquartile range, 43 to 225) days. In multivariable Cox proportional hazards analyses, patients were 2.07 times as likely to have a subsequent resistant infection (95% confidence interval, 1.11 to 3.87) if they received prophylaxis in the 30 days prior to the index infection. In 26 (58%) patients, all subsequent isolates were concordant with their index isolate, and 7 (16%) additional patients had at least 1 concordant subsequent isolate. In 12 of 17 (71%) patients with E. coli sequence type 131 (ST131)-associated type 40-30, all subsequent isolates were concordant. Subsequent extended-spectrum-cephalosporin-resistant infections are relatively frequent and are most commonly due to bacterial strains concordant with the index isolate. Further study is needed to assess the role prophylaxis plays in these resistant infections. </jats:p

Standard and derived Planck quantities: selected analysis and derivations

We provide an overview of the fundamental units of physical quantities determined naturally by the values of fundamental constants of nature. We discuss a comparison between the 'Planck units', now widely used in theoretical physics and the pre-quantum 'Stoney units' in which, instead of the Planck constant, the charge of the electron is used with very similar quantitative results. We discuss some of the physical motivation for these special units, attributed much after they were introduced, and also put forth a summary of the arguments supporting various cases for making specific physical interpretations of the meanings of some of these units. The new aspects we discuss are a possible physical basis for the Stoney units, their link to the Planck units, and also the importance of Planck units for thermodynamical quantities in the context of quantum gravity.Comment: 22 pages, 1 tabl

Neutralization of Diverse Human Cytomegalovirus Strains Conferred by Antibodies Targeting Viral gH/gL/pUL128-131 Pentameric Complex

Human cytomegalovirus (HCMV) is the leading cause of congenital viral infection, and developing a prophylactic vaccine is of high priority to public health. We recently reported a replication-defective human cytomegalovirus with restored pentameric complex glycoprotein H (gH)/gL/pUL128-131 for prevention of congenital HCMV infection. While the quantity of vaccine-induced antibody responses can be measured in a viral neutralization assay, assessing the quality of such responses, including the ability of vaccine-induced antibodies to cross-neutralize the field strains of HCMV, remains a challenge. In this study, with a panel of neutralizing antibodies from three healthy human donors with natural HCMV infection or a vaccinated animal, we mapped eight sites on the dominant virus-neutralizing antigen-the pentameric complex of glycoprotein H (gH), gL, and pUL128, pUL130, and pUL131. By evaluating the site-specific antibodies in vaccine immune sera, we demonstrated that vaccination elicited functional antiviral antibodies to multiple neutralizing sites in rhesus macaques, with quality attributes comparable to those of CMV hyperimmune globulin. Furthermore, these immune sera showed antiviral activities against a panel of genetically distinct HCMV clinical isolates. These results highlighted the importance of understanding the quality of vaccine-induced antibody responses, which includes not only the neutralizing potency in key cell types but also the ability to protect against the genetically diverse field strains. IMPORTANCE HCMV is the leading cause of congenital viral infection, and development of a preventive vaccine is a high public health priority. To understand the strain coverage of vaccine-induced immune responses in comparison with natural immunity, we used a panel of broadly neutralizing antibodies to identify the immunogenic sites of a dominant viral antigen-the pentameric complex. We further demonstrated that following vaccination of a replication-defective virus with the restored pentameric complex, rhesus macaques can develop broadly neutralizing antibodies targeting multiple immunogenic sites of the pentameric complex. Such analyses of site-specific antibody responses are imperative to our assessment of the quality of vaccine-induced immunity in clinical studies

Previous antibiotic exposure increases risk of infection with extended-spectrum-β-lactamase- and AmpC-producing Escherichia coli and Klebsiella pneumoniae in pediatric patients

The objective of this study was to determine whether antibiotic exposure is associated with extended-spectrum-beta-lactamase- or AmpC-producing Escherichia coli or Klebsiella pneumoniae infections in children. We collected extended-spectrum-beta-lactamase- or AmpC-producing E. coli or K. pneumoniae isolates and same-species susceptible controls from normally sterile sites of patients aged ≤21 years, along with associated clinical data, at four free-standing pediatric centers. After controlling for potential confounders, the relative risk of having an extended-spectrum-beta-lactamase-producing isolate rather than a susceptible isolate was 2.2 times higher (95% confidence interval [CI], 1.49 to 3.35) among those with antibiotic exposure in the 30 days prior to infection than in those with no antibiotic exposure. The results were similar when analyses were limited to exposure to third-generation cephalosporins, other broad-spectrum beta-lactams, or trimethoprim-sulfamethoxazole. Conversely, the relative risk of having an AmpC-producing versus a susceptible isolate was not significantly elevated with any antibiotic exposure in the 30 days prior to infection (adjusted relative risk ratio, 1.12; 95% CI, 0.65 to 1.91). However, when examining subgroups of antibiotics, the relative risk of having an AmpC-producing isolate was higher for patients with exposure to third-generation cephalosporins (adjusted relative risk ratio, 4.48; 95% CI, 1.75 to 11.43). Dose-response relationships between antibiotic exposure and extended-spectrum-beta-lactamase-producing or AmpC-producing isolates were not demonstrated. These results reinforce the need to study and implement pediatric antimicrobial stewardship strategies, and they indicate that epidemiological studies of third-generation cephalosporin-resistant E. coli and K. pneumoniae isolates should include resistance mechanisms when possible

The purpose of United Nations Security Council practice: Contesting competence claims in the normative context created by the Responsibility to Protect.

Practice theory provides important insight into the workings of the Security Council. The contribution is currently limited however by the conjecture that practice theory operates on ‘a different analytical plane’ to norm / normative theory (Adler-Nissen and Pouliot 2014). Building on existing critiques (Duval and Chowdhury 2011; Schindler and Wille 2015) we argue that analyzing practices separately from normative positions risks misappropriating competence and reifying practice that is not fit for purpose. This risk is realized in Adler-Nissen and Pouliot’s (2014) practice based account Libya crisis. By returning the normative context created by the Responsibility to Protect (R2P) to the analytical foreground, and by drawing on a pragmatic conception of 'ethical competence' (Frost 2009), we find that pre-reflexive practices uncritically accepted as markers of competence – e.g. ‘penholding’ – can contribute to the Council’s failure to act collectively in the face of mass atrocity. Drawing on extensive interview material we offer an alternative account of the Libya intervention, finding that the practices of the permanent three (France, UK and US) did not cultivate the kind of collective consciousness that is required to implement R2P. This is further illustrated by an account of the Security Council’s failure in Syria, where the P3’s insistence on regime change instrumentalized the Council at the expense of R2P-appropriate practice. This changed when elected members became ‘penholders’. Practice theory can facilitate learning processes that help the Council meet its responsibilities, but only through an approach that combines its insights with those of norm / normative theory

The functional response of a generalist predator

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