Algorithms for All Single Deletions in a Minimum Apanning Tree, Simulataneously

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryNational Science Foundation / NSF CCR-931569

The Need for New Search Strategies for Fourth Generation Quarks at the LHC

Most limits on the fourth generation heavy top quark (the t') are based on the assumed dominance of t' -> Wb, which is expected to be case in the minimal fourth generation framework with a single Higgs (the so called SM4). Here we show, within a variant of a Two Higgs Doublet Model with four generations of fermions, that, in general, a different t' detection strategy is required if the physics that underlies the new heavy fermionic degrees of freedom goes beyond the "naive" SM4. We find that the recent CMS lower bounds: m_{t'}< 450 GeV in the semi-leptonic channel pp -> t't' -> l\nu qqbb and m_{t'}< 557 GeV in the dilepton channel pp -> t't' ->ll\nu \nu bb, that were obtained using the customary (SM4-driven) detection strategies, do not apply. In particular, we demonstrate that if the decay t' -> ht dominates, then applying the "standard" CMS search tools leads to a considerably relaxed lower bound: m_{t'} >~350 GeV. We, therefore, suggest an alternative search strategy that is more sensitive to beyond SM4 dynamics of the fourth generation fermions.Comment: 12 pages, 8 figure

Human-centred automation to simplify the path to social and economic sustainability

Musculoskeletal Disorders (MSDs) pose a serious threat to sustainability in manufacturing. In particular, this phenomenon impacts the sustainability indicators of worker health and safety and the Gross Domestic Product (GDP). Effective MSD prevention measures would therefore constitute a remarkable contribution to social and economic sustainability. This chapter provides first an outline of existing methods to prevent MSD at the workplace. Analysis of the approaches yields that effective solutions require earmarked finances as well as qualified personnel, both of which are not affordable for many companies. In pursuit of solutions, Human-centred Automation (HCA), a recent paradigm in manufacturing, proposes the design of manufacturing systems using intelligent technology to support the worker instead of replacing him/her. HCA has the unique potential of reducing the effort needed to implement MSD prevention strategies by simplifying the path to social and economic sustainability. This chapter demonstrates this process with the example of the “Working Posture Controller” (WPC), which illustrates how the HCA concept can be applied. Finally, the lessons learned from the case are outlined, providing a vision of how future workplaces can benefit from HCA

Tumor-Shed PGE2 Impairs IL2Rγc-Signaling to Inhibit CD4+ T Cell Survival: Regulation by Theaflavins

BACKGROUND:Many tumors are associated with decreased cellular immunity and elevated levels of prostaglandin E2 (PGE2), a known inhibitor of CD4+ T cell activation and inducer of type-2 cytokine bias. However, the role of this immunomodulator in the survival of T helper cells remained unclear. Since CD4+ T cells play critical roles in cell-mediated immunity, detail knowledge of the effect tumor-derived PGE2 might have on CD4+ T cell survival and the underlying mechanism may, therefore, help to overcome the overall immune deviation in cancer. METHODOLOGY/PRINCIPAL FINDINGS:By culturing purified human peripheral CD4+ T cells or Jurkat cells with spent media of theaflavin- or celecoxib-pre-treated MCF-7 cells, we show that tumor-shed PGE2 severely impairs interleukin 2 receptor gammac (IL2Rgammac)-mediated survival signaling in CD4+ T cells. Indeed, tumor-shed PGE2 down-regulates IL2Rgammac expression, reduces phosphorylation as well as activation of Janus kinase 3 (Jak-3)/signal transducer and activator of transcription 5 (Stat-5) and decreases Bcl-2/Bax ratio thereby leading to activation of intrinsic apoptotic pathway. Constitutively active Stat-5A (Stat-5A1 6) over-expression efficiently elevates Bcl-2 levels in CD4+ T cells and protects them from tumor-induced death while dominant-negative Stat-5A over-expression fails to do so, indicating the importance of Stat-5A-signaling in CD4+ T cell survival. Further support towards the involvement of PGE2 comes from the results that (a) purified synthetic PGE2 induces CD4+ T cell apoptosis, and (b) when knocked out by small interfering RNA, cyclooxygenase-2 (Cox-2)-defective tumor cells fail to initiate death. Interestingly, the entire phenomena could be reverted back by theaflavins that restore cytokine-dependent IL2Rgammac/Jak-3/Stat-5A signaling in CD4+ T cells thereby protecting them from tumor-shed PGE2-induced apoptosis. CONCLUSIONS/SIGNIFICANCE:These data strongly suggest that tumor-shed PGE2 is an important factor leading to CD4+ T cell apoptosis during cancer and raise the possibility that theaflavins may have the potential as an effective immunorestorer in cancer-bearer

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Recent Advances in Our Understanding of the Role of Meltwater in the Greenland Ice Sheet System

Nienow, Sole and Cowton’s Greenland research has been supported by a number of UK NERC research grants (NER/O/S/2003/00620; NE/F021399/1; NE/H024964/1; NE/K015249/1; NE/K014609/1) and Slater has been supported by a NERC PhD studentshipPurpose of the review:  This review discusses the role that meltwater plays within the Greenland ice sheet system. The ice sheet’s hydrology is important because it affects mass balance through its impact on meltwater runoff processes and ice dynamics. The review considers recent advances in our understanding of the storage and routing of water through the supraglacial, englacial, and subglacial components of the system and their implications for the ice sheet Recent findings:   There have been dramatic increases in surface meltwater generation and runoff since the early 1990s, both due to increased air temperatures and decreasing surface albedo. Processes in the subglacial drainage system have similarities to valley glaciers and in a warming climate, the efficiency of meltwater routing to the ice sheet margin is likely to increase. The behaviour of the subglacial drainage system appears to limit the impact of increased surface melt on annual rates of ice motion, in sections of the ice sheet that terminate on land, while the large volumes of meltwater routed subglacially deliver significant volumes of sediment and nutrients to downstream ecosystems. Summary:  Considerable advances have been made recently in our understanding of Greenland ice sheet hydrology and its wider influences. Nevertheless, critical gaps persist both in our understanding of hydrology-dynamics coupling, notably at tidewater glaciers, and in runoff processes which ensure that projecting Greenland’s future mass balance remains challenging.Publisher PDFPeer reviewe

Chains of (dis)trust: exploring the underpinnings of knowledge sharing and quality care across mental health services

Quality and safety in healthcare settings are underpinned by organisational cultures, which facilitate or impede the refinement, sharing and application of knowledge. Avoiding the use of the term culture as a residual category, we focus specifically on describing chains of (dis)trust, analysing their development across relatively low-trust service contexts and their impact upon knowledge-sharing and caregiving. Drawing upon data from in-depth interviews with service users, healthcare professionals, service managers and other stakeholders across three mental healthcare (psychosis) teams in southern England, we identify micro-mechanisms that explain how (dis)trust within one intra-organisational relationship impacts upon other relationships. Experiences and inferences of vulnerability, knowledge, uncertainty, interests and time, among actors who are both trustees and trusters across different relationships, are pertinent to such analyses. This more micro-level understanding facilitates detailed conceptualisations of trust chains as meso-level tendencies that contribute to wider vicious or virtuous cycles of organisational (dis)trust. We explore how knowledge-sharing and caregiving are vitally interwoven within these chains of trust or distrust, enhancing and/or inhibiting the instrumental and communicative aspects of quality healthcare as a result

Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora

The Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% for the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/c charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1 ± 0.6 % and 84.1 ± 0.6 %, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation