Deep underground environments are ideal for low background searches due to the attenuation of cosmic rays by passage through the earth. However, they are affected by backgrounds from γ-rays emitted ...by 40K and the 238U and 232Th decay chains in the surrounding rock. The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a liquid xenon TPC located within the Davis campus at the Sanford Underground Research Facility, Lead, South Dakota, at the 4850-foot level. In order to characterise the cavern background, in-situ γ-ray measurements were taken with a sodium iodide detector in various locations and with lead shielding. The integral count rates (0–3300 keV) varied from 596 Hz to 1355 Hz for unshielded measurements, corresponding to a total flux from the cavern walls of 1.9±0.4 $γ$ cm-2s-1. The resulting activity in the walls of the cavern can be characterised as 220±60 Bq/kg of 40K, 29±15 Bq/kg of 238U, and 13±3 Bq/kg of 232Th.
Deep underground environments are ideal for low background searches due to the attenuation of cosmic rays by passage through the earth. However, they are affected by backgrounds from γ-rays emitted ...by 40K and the 238U and 232Th decay chains in the surrounding rock. The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a liquid xenon TPC located within the Davis campus at the Sanford Underground Research Facility, Lead, South Dakota, at the 4850-foot level. In order to characterise the cavern background, in-situ γ-ray measurements were taken with a sodium iodide detector in various locations and with lead shielding. The integral count rates (0–3300 keV) varied from 596 Hz to 1355 Hz for unshielded measurements, corresponding to a total flux from the cavern walls of 1.9±0.4 $γ$ cm-2s-1. The resulting activity in the walls of the cavern can be characterised as 220±60 Bq/kg of 40K, 29±15 Bq/kg of 238U, and 13±3 Bq/kg of 232Th.
The Large Hadron Collider at CERN restarted in 2015 with a higher centre-of-mass energy of 13TeV. The instantaneous luminosity is expected to increase significantly in the coming years. An upgraded ...Level-1 trigger system has been deployed in the Compact Muon Solenoid experiment, in order to maintain the same efficiencies for searches and precision measurements as those achieved in the previous run. This system consists of the order of 100 electronics boards connected by the order of 3000 optical links, which must be controlled and monitoring coherently through software, with high operational efficiency. In this paper, we present the design of the software framework that is used to control and monitor the upgraded Level-1 trigger system, and experiences from using this software to commission the upgraded system.
This white paper presents the current status of the R&D for Analysis Facilities (AFs) and attempts to summarize the views on the future direction of these facilities. These views have been collected ...through the High Energy Physics (HEP) Software Foundation's (HSF) Analysis Facilities forum, established in March 2022, the Analysis Ecosystems II workshop, that took place in May 2022, and the WLCG/HSF pre-CHEP workshop, that took place in May 2023. The paper attempts to cover all the aspects of an analysis facility.
We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of ...highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.
Investment planning models inform investment decisions and government policies. Current models do not capture the intermittent nature of renewable energy sources, restricting the applicability of the ...models for high penetrations of renewables. We provide a methodology to capture spatial variation in wind output in combination with transmission constraints. The representation of wind distributions using stochastic approaches or using extensive historic data sets exceeds computational constraints for real world application. Hence we restrict the amount of input data, and use bootstrapping to illustrate the robustness of the results. For the UK power system we model wind deployment and the value of transmission capacity.
Peripheral blood cytopenias are a serious, dose-limiting toxicity of AZT therapy in patients infected by HIV. To evaluate the mechanism by which cytopenias develop, AZT effects of haematopoietic ...differentiation and growth were measured in serum-free, nucleoside-depleted cultures of normal human bone marrow. In contrast to native thymidine, AZT suppressed the proliferation of erythroid, granulocyte/macrophage and primitive haematopoietic stem cells in a dose-related and time-dependent fashion. Relative progenitor sensitivity varied, with half-maximal concentrations of 1-5 microM and 20-40 microM AZT for inhibition of erythroid and nonerythroid progenitor cell growth, respectively. Inhibition was observed over full ranges of concentrations of haematopoietic tissue-specific regulators (human erythropoietin, colony-stimulating activity, interleukin-3 and lymphocyte conditioned medium) and of platelet-derived growth factor (PDGF), an agent that enhances erythropoiesis in vitro via accessory marrow stromal elements. Furthermore, suppression was similar in cultures of marrow cells that were depleted of accessory populations, suggesting that its action is directed at progenitors. Finally, when deoxythymidine was added in increasing amounts to cultures with a half-maximal concentration of AZT, inhibition was abrogated. We conclude that AZT is a potent inhibitor of haematopoiesis in vitro, and that erythroid progenitors are particularly sensitive to its action. These results may explain the marrow hypoplasia that occurs during AZT administration in vivo.
We have investigated the role of contractile proteins of circulating mononuclear cells in generation of membrane-associated, erythroid growth regulatory molecules. Lymphocytes and monocytes were ...incubated under serum-free conditions without and with cytochalasin B, cytochalasin D, or colchicine, and effects on positive and negative erythropoietic activities were determined in cell membranes and in surface membrane vesicle-rich pellets and supernatants of dialyzed medium conditioned by the cells. In serum-free cultures of human bone marrow, plasma membranes and exfoliated membrane-derived vesicles from cytochalasin-treated lymphocytes lost their capacity to support the formation of erythroid bursts, while monocyte membrane-associated inhibitory activity was abolished by preincubation with cytochalasin. In contrast, membrane-associated activities of colchicine-treated cells were unaffected. Cytochalasin-induced alterations of membrane regulatory molecules were observed in a dose-dependent fashion over a wide range of concentrations (1 to 100 micrograms/mL) tested. However, the capacity of membrane vesicle-free supernatants of medium conditioned by lymphocytes or monocytes was unaffected by cytochalasins, regardless of drug concentration used. Lysates of cytochalasin B-treated cells inhibited the activity of deoxyribonuclease I to a greater degree than did lysates of untreated cells, suggesting that the relative amount of monomeric actin is increased in the cytoplasm of treated cells. Furthermore, results of experiments with D-glucose and with cytochalasin D suggest that cytochalasin effects are independent of alterations in glucose metabolism. The data indicate that expression of plasma membrane- associated regulators is sensitive to agents that block polymerization of actin. They raise the possibility that changes in distribution of actin between unpolymerized and filamentous pools may influence the organization and/or function of mononuclear cell surface-associated erythroid regulatory molecules.
We have investigated the role of contractile proteins of circulating mononuclear cells in generation of membraneassociated, erythroid growth regulatory molecules. Lymphocytes and monocytes were ...incubated under serum-free conditions without and with cytochalasin B, cytochalasin D, or colchicine, and effects on positive and negative erythropoietic activities were determined in cell membranes and in surface membrane vesicle-rich pellets and supernatants of dialyzed medium conditioned by the cells. In serum-free cultures of human bone marrow, plasma membranes and exfoliated membrane-derived vesicles from cytochalasintreated lymphocytes lost their capacity to support the formation of erythroid bursts, while monocyte membraneassociated inhibitory activity was abolished by preincubation with cytochalasin. In contrast, membrane-associated activities of colchicine-treated cells were unaffected. Cytochalasin-induced alterations of membrane regulatory molecules were observed in a dose-dependent fashion over a wide range of concentrations (1 to 100 μg/mL) tested. However, the capacity of membrane vesicle-free supernatants of medium conditioned by lymphocytes or monocytes was unaffected by cytochalasins, regardless of drug concentration used. Lysates of cytochalasin B-treated cells inhibited the activity of deoxyribonuclease I to a greater degree than did lysates of untreated cells, suggesting that the relative amount of monomeric actin is increased in the cytoplasm of treated cells. Furthermore, results of experiments with D-glucose and with cytochalasin D suggest that cytochalasin effects are independent of alterations in glucose metabolism. The data indicate that expression of plasma membrane-associated regulators is sensitive to agents that block polymerization of actin. They raise the possibility that changes in distribution of actin between unpolymerized and filamentous pools may influence the organization and/or function of mononuclear cell surfaceassociated erythroid regulatory molecules.
Endothelial cells are a known source of hematopoietic growth-enhancing factors, including platelet-derived growth factor (PDGF). In addition, endothelium interacts directly with plasma lipoproteins ...which have been shown to modulate hematopoiesis. To determine the relationship of these properties, we measured the release of an erythroid growth-enhancing factor from bovine endothelial cells under lipid-loaded and control conditions. Human bone marrow cells cultured under serum-free conditions form more erythroid, granulocyte/macrophage, and mixed hematopoietic colonies when supplemented with endothelial cell-conditioned medium (ECCM) than do controls (P less than 0.05). The activity is expressed over a wide range of erythropoietin, lymphocyte-conditioned medium (LCM), recombinant human interleukin-3, and colony-stimulating factor (CSF) concentrations, and is related to ECCM dose. In contrast, enhancing activity in ECCM prepared with 0-400 micrograms/ml acetylated low density lipoproteins (AcLDL) or native LDL is diminished to 0% in a dose-dependent fashion (relative to ECCM from unexposed cells or from cells incubated with very low density lipoproteins, P less than 0.05). Upon dilution, medium prepared from cells incubated with LDL shows a rightward shift in the dose-response curve for erythroid colony formation, while that prepared from AcLDL loaded cells demonstrates a downward shift, indicating that the inhibitory activities are kinetically distinct. Delipidation of ECCM prior to addition to marrow culture removes the inhibitory action of native LDL (P less than 0.05) but not that of AcLDL (P greater than 0.10). Immunochemical analysis suggests that the erythropoietic activity in ECCM is unrelated to that of PDGF, recombinant human CSF, and erythroid burst-promoting activity (BPA) present in LCM. This conclusion is supported by Northern blot analysis of endothelial cells using a cDNA probe for the v-sis homologue of the PDGF beta chain and by immunoprecipitation of metabolically labeled PDGF. The relative amounts of c-sis transcripts and of secreted PDGF were similar in endothelial cells incubated with or without AcLDL. We conclude that AcLDL impair the synthesis or release of an erythropoietic growth-enhancing factor(s) which is biologically distinct from PDGF and BPA present in LCM.
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