1,012 research outputs found
A study on the hadroproduction of heavy resonances in ATLAS experiment at the LHC
This work is devoted to the study of the hadroproduction of heavy resonances and related topics. The study begins with a chapter that analyzes some experimental issues on heavy quarkonia production, pointing out the important role that the ATLAS detector at LHC can play in this regard. The main goal of chapter 2 is revising some theoretical aspects on bottomonia production, some relevant heavy quarkonia production models are visited, pointing out the most relevant features involved in this work. Later, chapter 3 describes the most relevant techniques used in order to generate the Upsilon(nS) family, as well as a description on the changes and new implementations in the original software of PYTHIA: In summary, all the tools that we needed when carrying out the bottomonia hadroproduction analysis. In chapter 4 we focused on the study of the information available on Upsilon production, basing our analysis of bottomonia inclusive production on the results from Run IB of the CDF collaboration : We analyze the differential Upsilon(nS) cross sections, extracting some relevant NRQCD matrix elements, paying attention to the problem concerning the factorization of the cross section, etc. In chapter 5 we make some predictions on bottomonium hadroproduction at the forthcoming LHC energies and kinematic conditions: We show the expected differential and integrated cross section for all Upsilon(nS) resonances, etc. In chapter 6 we present a proposal to probe gluon densities in the proton using Upsilon hadroproduction, within the framework of the colour-octet mechanism. Aside the proposal, we included predicted production rates, and details that arose during the development of the idea. Finally, in order to help the reading of this work, a lot of technical details have been separated from the main body of the text, gathering them in the appendices A-B-C
New accurate measurement of 36ArH+ and 38ArH+ ro-vibrational transitions by high resolution IR absorption spectroscopy
The protonated Argon ion, ArH, has been identified recently in
the Crab Nebula (Barlow et al. 2013) from Herschel spectra. Given the
atmospheric opacity at the frequency of its =1-0 and =2-1 rotational
transitions (617.5 and 1234.6 GHz, respectively), and the current lack of
appropriate space observatories after the recent end of the Herschel mission,
future studies on this molecule will rely on mid-infrared observations. We
report on accurate wavenumber measurements of ArH and
ArH rotation-vibration transitions in the =1-0 band in the
range 4.1-3.7 m (2450-2715 cm). The wavenumbers of the (0)
transitions of the =1-0 band are 2612.501350.00033 and
2610.701770.00042 cm () for ArH and
ArH, respectively. The calculated opacity for a gas thermalized at
a temperature of 100 K and a linewidth of 1 km.s of the (0) line is
(ArH). For column densities of
ArH larger than cm, significant absorption
by the (0) line can be expected against bright mid-IR sources
Prospects for probing the gluon density in protons using heavy quarkonium hadroproduction
We examine carefully bottomonia hadroproduction in proton colliders,
especially focusing on the LHC, as a way of probing the gluon density in
protons. To this end we develop some previous work, getting quantitative
predictions and concluding that our proposal can be useful to perform
consistency checks of the parameterization sets of different parton
distribution functions.Comment: LaTeX, 14 pages, 6 EPS figure
Detection of the Ammonium Ion in Space
We report on the detection of a narrow feature at 262816.73 MHz towards Orion
and the cold prestellar core B1-bS, that we attribute to the 1(0)-0(0) line of
the deuterated Ammonium ion, NH3D+. The observations were performed with the
IRAM 30m radio telescope. The carrier has to be a light molecular species as it
is the only feature detected over 3.6 GHz of bandwidth. The hyperfine structure
is not resolved indicating a very low value for the electric quadrupolar
coupling constant of Nitrogen which is expected for NH3D+ as the electric field
over the N nucleus is practically zero. Moreover, the feature is right at the
predicted frequency for the 1(0)-0(0) transition of the Ammonium ion, 262817(6)
MHz (3sigma), using rotational constants derived from new infrared data
obtained in our laboratory in Madrid. The estimated column density is
1.1(0.2)e12 cm-2. Assuming a deuterium enhancement similar to that of NH2D, we
derive N(NH4+) sim 2.6e13 cm-2, i.e., an abundance for Ammonium of a few
1e(-11).Comment: Accepted for publication in the Astrophysical Journal Letters 04 June
201
Estimating the impact of influenza on the epidemiological dynamics of SARS-CoV-2
As in past pandemics, co-circulating pathogens may play a role in the epidemiology of coronavirus disease 2019 (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In particular, experimental evidence indicates that influenza infection can up-regulate the expression of ACE2âthe receptor of SARS-CoV-2 in human cellsâand facilitate SARS-CoV-2 infection. Here we hypothesized that influenza impacted the epidemiology of SARS-CoV-2 during the early 2020 epidemic of COVID-19 in Europe. To test this hypothesis, we developed a population-based model of SARS-CoV-2 transmission and of COVID-19 mortality, which simultaneously incorporated the impact of non-pharmaceutical control measures and of influenza on the epidemiological dynamics of SARS-CoV-2. Using statistical inference methods based on iterated filtering, we confronted this model with mortality incidence data in four European countries (Belgium, Italy, Norway, and Spain) to systematically test a range of assumptions about the impact of influenza. We found consistent evidence for a 1.8â3.4-fold (uncertainty range across countries: 1.1 to 5.0) average population-level increase in SARS-CoV-2 transmission associated with influenza during the period of co-circulation. These estimates remained robust to a variety of alternative assumptions regarding the epidemiological traits of SARS-CoV-2 and the modeled impact of control measures. Although further confirmatory evidence is required, our results suggest that influenza could facilitate the spread and hamper effective control of SARS-CoV-2. More generally, they highlight the possible role of co-circulating pathogens in the epidemiology of COVID-19
Anti-inflammatory, pro-proliferative and antimicrobial potential of the compounds isolated from Daemonorops draco (Willd.) Blume
Ethno-pharmacological relevance: Daemonorops draco (D. draco) commonly known as âDragon's bloodâ is one of the most used plants by Momok, Anak Dalam and Talang Mamak tribes from Indonesia as a remedy for wound healing. Aim of the study: This study aimed to identify the extract, fractions and compounds responsible for the anti-inflammatory and pro-proliferative activities of the D. draco resin. Additionally, the antimicrobial activity against two bacteria and one yeast species was analysed. Materials and methods: Bio-guided isolation of compounds with anti-inflammatory, pro-proliferative and antimicrobial activities from the D. draco resin was carried out by measuring: the inhibition of NF-ÎșB and activation of Nrf2 in THP-1, HaCaT, NIH-3T3 cells; cell proliferation in NIH-3T3 and HaCaT cells; and the antimicrobial effect on E. coli, S. aureus and C. albicans. Results: Guided isolation by bioassay gave rise to the isolation and characterisation by nuclear magnetic resonance and mass spectrometry of three compounds: 1 (Bexarotene), 2 (Taspine) and 3 (2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone). All compounds showed NF-ÎșB inhibitory activity with IC50 values of 0.10â0.13, 0.22â0.24 and 3.75â4.78 ÎŒM, respectively, while the positive control, Celastrol, had an IC50 of 7.96 ÎŒM. Likewise, all compounds showed an activating effect of Nrf2 with EC50 values of 5.34â5.43, 163.20â169.20 and 300.82â315.56 nM, respectively, while the positive control, CDDO-Me, had an EC50 of 0.11 nM. In addition, concerning the pro-proliferative activity, compound 1 (IC50 = 8.62â8.71 nM) showed a capacity of 100%, compound 2 (IC50 = 166â171 nM) showed a capacity of 75%, and compound 3 (IC50 = 469â486 nM) showed a capacity of 65%, while FSB 10% (positive control) had a pro-proliferative activity of 100% in the NIH3T3 cell lines (fibroblasts) and HaCaT (keratinocytes). Finally, all the compounds showed antimicrobial activity with MIC values of 0.12â0.16, 0.31â0.39 and 3.96â3.99 ÎŒM, respectively, in S. aureus, E. coli and C. albicans strains, while the positive control, Ofloxacin, had a MIC of 27.65 ÎŒM. Conclusion: This study managed to isolate, for the first time, three compounds (Bexarotene, Taspine and 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone) from the resin of D. draco, with anti-inflammatory, and pro-proliferative as well as antimicrobial activitie
A 3D mathematical model for planning ostectomy on long-bone angular deformities
This study describes a 3D mathematical model for planning a corrective ostectomy on long bones with angular deformities based on CT imaging. The use of three-dimensional information allows the model to compute and correct the bone angulation and rotation. The cutting point selection is developed minimizing the bone length reduction inherent in an ostectomy process. An example of its application on a two year old dog is shown at the end of the paper.Veterinari
Ethnicity Does Not Impact Physical Therapy Studentsâ Clinical Readiness and Performance, a United States Exploratory Study
Purpose: To explore the impact of ethnicity on clinical readiness and performance among Doctor of Physical Therapy (DPT) students, as determined by 1) Physical Therapist Self-Efficacy (PTSE) score, 2) self-confidence treating patients, and 3) final American Physical Therapy Association (APTA) Clinical Performance Instrument (CPI) clinical reasoning and summative ratings during clinical experiences. Methods: This study is a survey-based, descriptive, and exploratory cross-sectional research design involving sample of 211 DPT students evaluated for differences across ethnic studentsâ groups 1) PTSE score during student clinical experiences, 2) confidence with treating initial and subsequent same-patient visits, and 3) final CPI clinical reasoning and summative scores during clinical experiences. Results: Kruskal-Wallis test showed no difference across ethnic groups (American Indian or Alaskan Native, Asian/Pacific Islander, Black or African American, Hispanic, White or Caucasian, prefer not to answer, and multiple ethnicity) in 1) clinical reasoning self-efficacy (PTSE), n=211, p=.438; 2) confidence treating at initial visit n=211, p=.088 and subsequent patient visits n=211, p=.584; and 3) clinical performance on the CPI for clinical reasoning n=211, p=.273 and summative n=211, p=.189 scores. Conclusions and Recommendations: All ethnic groups demonstrated strong clinical readiness and performance during each clinical experience level. Ethnic groups did not differ on clinical reasoning self-efficacy or confidence treating patients. Although the gap appears to be closing, there continues to be underrepresentation of ethnic groups in DPT programs. We recommend investigating factors impacting underrepresentation of ethnic groups in DPT academic programs to explore initiatives to close the diversity gap and best match societal representation
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