The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction

Search for long-lived neutral particles in pp collisions at s√=13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter

This paper describes a search for pairs of neutral, long-lived particles decaying in the ATLAS calorimeter. Long-lived particles occur in many extensions to the Standard Model and may elude searches for new promptly decaying particles. The analysis considers neutral, long-lived scalars with masses between 5 and 400 GeV, produced from decays of heavy bosons with masses between 125 and 1000 GeV, where the long-lived scalars decay into Standard Model fermions. The analysis uses either 10.8 fb−1 or 33.0 fb−1 of data (depending on the trigger) recorded in 2016 at the LHC with the ATLAS detector in proton–proton collisions at a centre-of-mass energy of 13 TeV. No significant excess is observed, and limits are reported on the production cross section times branching ratio as a function of the proper decay length of the long-lived particles

Global Retinoblastoma Presentation and Analysis by National Income Level

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4) were female. Most patients (n = 3685 84.7%) were from low-and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 62.8%), followed by strabismus (n = 429 10.2%) and proptosis (n = 309 7.4%). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 95% CI, 12.94-24.80, and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 95% CI, 4.30-7.68). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs. © 2020 American Medical Association. All rights reserved

Islamic Commercial Law (II): An overview. Some principles and rules

Shari¿a commercial law is a complex system and covers numerous areas. Accordingly, only a selective and general overview can be given. This includes a look at some general principles, followed by an examination of some aspects that are characteristic of the regime, markedly different from those to which Western lawyers are accustomed, or both. In addition, it should be borne in mind that it is not possible to provide an account that is at the same time brief and wholly accurate. What follows, therefore, can be an approximation only

Textural, chemical and isotopic insights into the nature and behaviour of metamorphic monazite

Monazite is a mineral of choice for dating metamorphism in amphibolite- and granulite-grade metapelites. However, there exist a number of difficulties that complicate the interpretation of monazite geochronological data and prevent its application to many geological problems. The two main obstacles addressed in this contribution are firstly, the minor but significant (e.g. 1–30 Ma) dispersal in duplicate isotope dilution thermal ionisation mass spectrometry (ID-TIMS) U–Pb age data commonly recorded from a single rock, and secondly, the difficulty of attaching monazite age data to pressure and temperature information. Through a multidisciplinary approach utilising TIMS and laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) isotope data, quantitative and qualitative EMP chemical analyses of monazite, and textural studies, we assess the significance of Pb loss, older components, and continuous and episodic monazite growth in the generation of dispersed age data. Three samples from the Canadian Cordillera and one sample from the Himalaya of Pakistan are examined. Each sample exhibits an age dispersion of between 1 and 12 Ma for single crystal and multi-grain TIMS U–Pb monazite age determinations. Consideration of the closure temperature for Pb diffusion in monazite and the metamorphic temperatures experienced by these samples suggests diffusive Pb loss did not play a significant part in generating this age dispersal. The LA-MC-ICPMS study indicates that an older component (<100 Ma older than the TIMS ages) contributed to the age dispersal in three of the four samples. In all the samples however, chemical analyses identified that the majority of monazites examined exhibited significant intra-crystalline zoning in Y content. The LA-MC-ICPMS analysis of one sample that was constrained to zones of distinct Y content indicates that these zones are of distinct age. We suggest that monazite grown before the appearance of garnet and during garnet breakdown is relatively rich in Y, whereas monazite grown after garnet is relatively poor in Y. A combination of these chemical data with textural observations suggests that once monazite had entered the mineral assemblage it grew or recrystallised episodically throughout the prograde and retrograde paths of the metamorphic event. This behaviour contributes to, and in one of the samples controls, the observed age dispersal. This recognition allows the generation of pressure–temperature�time points by combining textural and chemical information of monazite with in situ age determinations, and pressure–temperature information from garnet. Thus, the episodic growth of compositionally distinct monazite throughout a metamorphic event provides the geochronologist with a very valuable chronological tool