Case 27-2011: A 17-Year-Old Boy with Abdominal Pain and Weight Loss

Pr e sen tat ion of C a se Dr. Nina Mayer (Medicine-Pediatrics): A 17-year-old boy was seen in the pediatric gastroenterology clinic of this hospital because of abdominal pain and weight loss. The patient had been well until approximately 6 weeks earlier, when intermittent crampy abdominal pain developed. Approximately 3 weeks later, nonbloody diarrhea developed and lasted for a week, associated with one episode of emesis. Thereafter, abdominal pain occurred daily, was predominantly located in the right lower quadrant, radiated to the right flank, and was associated with lower back discomfort, borborygmi, and constipation. During the fourth week of illness, after the diarrhea had resolved, the patient saw his primary care physician. Serum levels of glucose, alanine aminotransferase, and thyrotropin were normal, as were tests of renal function. Tests for tissue transglutaminase IgA antibodies, hepatitis A virus, hepatitis C virus, and the human immunodeficiency virus (HIV) were negative. Results of tests for serum antibodies to Epstein-Barr virus (EBV) were consistent with past infection; testing was positive for hepatitis B virus surface antibody and negative for hepatitis B surface antigen, indicating immunity or past infection. Other results are shown in Two weeks later, the patient was seen in the pediatric gastroenterology clinic at this hospital. He rated the abdominal pain at 5 on a scale of 0 to 10, with 10 indicating the most severe pain. He reported one bowel movement of hard stool daily, and one episode of blood streaking on the stool after straining, with no mucus. He reported that he had lost 18.2 kg during the previous 2 years. The first 11 to 12 kg was intentional; however, during the 6 weeks before this evaluation, additional weight loss had occurred unintentionally. The body-mass index (the weight in kilograms divided by the square of the height in meters) had reportedly decreased from 27.0 (>95th percentile for his age) to 20.5 (25th to 50th percentile). He reported night sweats with chills but no fever. The patient had visited relatives in Haiti approximately 4 years earlier for 1 week; he reported no exposure to persons with respiratory or gastrointestinal symptoms while there or recently. Skin tests for tuberculosis were reportedly negative befor

Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements

Measurement of W± and Z-boson production cross sections in pp collisions at √s=13 TeV with the ATLAS detector

See paper for full list of authors - 17 pages plus author list + cover pages (34 pages total), 5 figures, 3 tables, submitted to Phys. Lett. B, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2015-03/International audienceMeasurements of the $W^{\pm} \rightarrow \ell^{\pm} \nu$ and $Z \rightarrow \ell^+ \ell^-$ production cross sections (where $\ell^{\pm}=e^{\pm},\mu^{\pm}$) in proton-proton collisions at $\sqrt{s}=13$ TeV are presented using data recorded by the ATLAS experiment at the Large Hadron Collider, corresponding to a total integrated luminosity of 81 pb$^{-1}$. The total inclusive $W^{\pm}$-boson production cross sections times the single-lepton-flavour branching ratios are $\sigma_{W^+}^{tot}= 11.78 \pm 0.02 (stat) \pm 0.32 (sys) \pm 0.59 (lumi)$ nb and $\sigma_{W^-}^{tot} = 8.75 \pm 0.02 (stat) \pm 0.24 (sys) \pm 0.44 (lumi)$ nb for $W^+$ and $W^-$, respectively. The total inclusive $Z$-boson production cross section times leptonic branching ratio, within the invariant mass window $66 < m_{\ell\ell} < 116$ GeV, is $\sigma_{Z}^{tot} = 1.97 \pm 0.01 (stat) \pm 0.04 (sys) \pm 0.10 (lumi)$ nb. The $W^+$, $W^-$, and $Z$-boson production cross sections and cross-section ratios within a fiducial region defined by the detector acceptance are also measured. The cross-section ratios benefit from significant cancellation of experimental uncertainties, resulting in $\sigma_{W^+}^{fid}/\sigma_{W^-}^{fid} = 1.295 \pm 0.003 (stat) \pm 0.010 (sys)$ and $\sigma_{W^{\pm}}^{fid}/\sigma_{Z}^{fid} = 10.31 \pm 0.04 (stat) \pm 0.20 (sys)$. Theoretical predictions, based on calculations accurate to next-to-next-to-leading order for quantum chromodynamics and next-to-leading order for electroweak processes and which employ different parton distribution function sets, are compared to these measurements

Search for an invisibly decaying Higgs boson or dark matter candidates produced in association with a Z boson in pp collisions at root s=13 TeV with the ATLAS detector

SCOAP