317 research outputs found
Towards a Precise Parton Luminosity Determination at the CERN LHC
A new approach to determine the LHC luminosity is investigated. Instead of
employing the proton-proton luminosity measurement, we suggest to measure
directly the parton-parton luminosity. It is shown that the electron and muon
pseudorapidity distributions, originating from the decay of W+, W- and Z0
bosons produced at 14 TeV pp collisions (LHC), constrain the x distributions of
sea and valence quarks and antiquarks in the range from about 3 x 10**-4 to
about 10**-1 at a Q**2 of about 10**4 GeV**2. Furthermore, it is demonstrated
that, once the quark and antiquark structure functions are constrained from the
W+,W- and Z0 production dynamics, other quark-antiquark related scattering
processes at the LHC like q-qbar --> W+W- can be predicted accurately. Thus,
the lepton pseudorapidity distributions provide the key to a precise parton
luminosity monitor at the LHC, with accuracies of about +-1% compared to the so
far considered goal of +-5%.Comment: plain tex, 14 pages, 5 figure
Enhancement of stability in randomly switching potential with metastable state
The overdamped motion of a Brownian particle in randomly switching piece-wise
metastable linear potential shows noise enhanced stability (NES): the noise
stabilizes the metastable system and the system remains in this state for a
longer time than in the absence of white noise. The mean first passage time
(MFPT) has a maximum at a finite value of white noise intensity. The analytical
expression of MFPT in terms of the white noise intensity, the parameters of the
potential barrier, and of the dichotomous noise is derived. The conditions for
the NES phenomenon and the parameter region where the effect can be observed
are obtained. The mean first passage time behaviours as a function of the mean
flipping rate of the potential for unstable and metastable initial
configurations are also analyzed. We observe the resonant activation phenomenon
for initial metastable configuration of the potential profile.Comment: 9 pages, 5 figures. In press in "European Physical Journal B
Dynamics and manipulation of entanglement in coupled harmonic systems with many degrees of freedom
Published versio
Look me in the eyes: constraining gaze in the eye-region provokes abnormally high subcortical activation in autism
FSW – Publicaties zonder aanstelling Universiteit Leide
Impact of the COVID-19 pandemic on TB services at ART programmes in low- and middle-income countries: a multi-cohort survey.
INTRODUCTION
COVID-19 stretched healthcare systems to their limits, particularly in settings with a pre-existing high burden of infectious diseases, including HIV and tuberculosis (TB). We studied the impact of COVID-19 on TB services at antiretroviral therapy (ART) clinics in low- and middle-income countries.
METHODS
We surveyed ART clinics providing TB services in the International Epidemiology Databases to Evaluate AIDS (IeDEA) consortium in Africa and the Asia-Pacific until July 2021 (TB diagnoses until the end of 2021). We collected site-level data using standardized questionnaires.
RESULTS
Of 46 participating ART clinics, 32 (70%) were in Africa and 14 (30%) in the Asia-Pacific; 52% provided tertiary care. Most clinics (85%) reported disrupted routine HIV care services during the pandemic, both in Africa (84%) and the Asia-Pacific (86%). The most frequently reported impacts were on staff (52%) and resource shortages (37%; protective clothing, face masks and disinfectants). Restrictions in TB health services were observed in 12 clinics (26%), mainly reduced access to TB diagnosis and postponed follow-up visits (6/12, 50% each), and restrictions in TB laboratory services (22%). Restrictions of TB services were addressed by dispensing TB drugs for longer periods than usual (7/12, 58%), providing telehealth services (3/12, 25%) and with changes in directly observed therapy (DOT) (e.g. virtual DOT, 3/12). The number of TB diagnoses at participating clinics decreased by 21% in 2020 compared to 2019; the decline was more pronounced in tertiary than primary/secondary clinics (24% vs. 12%) and in sites from the Asia-Pacific compared to Africa (46% vs. 14%). In 2021, TB diagnoses continued to decline in Africa (-8%) but not in the Asia-Pacific (+62%) compared to 2020. During the pandemic, new infection control measures were introduced or intensified at the clinics, including wearing face masks, hand sanitation and patient triage.
CONCLUSIONS
The COVID-19 pandemic led to staff shortages, reduced access to TB care and delays in follow-up visits for people with TB across IeDEA sites in Africa and the Asia-Pacific. Increased efforts are needed to restore and secure ongoing access to essential TB services in these contexts
Bivalent therapeutic vaccine against HPV16/18 genotypes consisting of a fusion protein between the extra domain A from human fibronectin and HPV16/18 E7 viral antigens.
In vivo targeting of human papillomavirus (HPV) derived antigens to dendritic cells might constitute an efficient immunotherapeutic strategy against cervical cancer. In previous works, we have shown that the extra domain A from murine fibronectin (mEDA) can be used to target antigens to toll-like receptor 4 (TLR4) expressing dendritic cells and induce strong antigen-specific immune responses. In the present study, we have produced a bivalent therapeutic vaccine candidate consisting of the human EDA (hEDA) fused to E7 proteins from HPV16 and HPV18 (hEDA-HPVE7-16/18) and evaluate its potential as a therapeutic vaccine against cervical cancer.
Recombinant fusion proteins containing HPV E7 proteins from HPV16 and HPV18 virus subtypes fused to hEDA were produced and tested in vitro on their capacity to bind TLR4 and induce the production of tumor necrosis factor-α or interleukin (IL)-12 by human monocytes and dendritic cells. The immunogenicity and potential therapeutic activity of the vaccine in combination with cisplatin or with the TLR3 agonist molecules polyinosinic-polycytidylic acid (Poly IC) or Poly ICLC was evaluated in mice bearing subcutaneous or genital orthotopic HPV16 TC-1 tumors.
hEDA-HPVE7-16/18 prototype vaccine binds human TLR4 and stimulate TLR4-dependent signaling pathways and IL-12 production by human monocyte-derived dendritic cell. Vaccination with hEDA-HPVE7-16/18 induced strong HPVE7-specific Cytotoxic T lymphocyte (CTL) responses and eliminated established tumors in the TC-1-based tumor model. The antitumor efficacy was significantly improved by combining the fusion protein with cisplatin or with the TLR-3 ligand Poly IC and especially with the stabilized analog Poly ICLC. Moreover, hEDA-HPVE7-16/18+Poly ICLC induced full tumor regression in 100% of mice bearing orthotopic genital HPV tumors.
Our results suggest that this therapeutic vaccine formulation may be an effective treatment for cervical tumors that do not respond to current therapies
Bumetanide for autism: more eye contact, less amygdala activation.
We recently showed that constraining eye contact leads to exaggerated increase of amygdala activation in autism. Here, in a proof of concept pilot study, we demonstrate that administration of bumetanide (a NKCC1 chloride importer antagonist that restores GABAergic inhibition) normalizes the level of amygdala activation during constrained eye contact with dynamic emotional face stimuli in autism. In addition, eye-tracking data reveal that bumetanide administration increases the time spent in spontaneous eye gaze during in a free-viewing mode of the same face stimuli. In keeping with clinical trials, our data support the Excitatory/Inhibitory dysfunction hypothesis in autism, and indicate that bumetanide may improve specific aspects of social processing in autism. Future double-blind placebo controlled studies with larger cohorts of participants will help clarify the mechanisms of bumetanide action in autism
Outcomes of Patients Lost to Follow-up in African Antiretroviral Therapy Programs: Individual Patient Data Meta-analysis.
BACKGROUND: Low retention on combination antiretroviral therapy (cART) has emerged as a threat to the Joint United Nations Programme on human immunodeficiency virus (HIV)/AIDS (UNAIDS) 90-90-90 targets. We examined outcomes of patients who started cART but were subsequently lost to follow-up (LTFU) in African treatment programs. METHODS: This was a systematic review and individual patient data meta-analysis of studies that traced patients who were LTFU. Outcomes were analyzed using cumulative incidence functions and proportional hazards models for the competing risks of (i) death, (ii) alive but stopped cART, (iii) silent transfer to other clinics, and (iv) retention on cART. RESULTS: Nine studies contributed data on 7377 patients who started cART and were subsequently LTFU in sub-Saharan Africa. The median CD4 count at the start of cART was 129 cells/μL. At 4 years after the last clinic visit, 21.8% (95% confidence interval [CI], 20.8%-22.7%) were known to have died, 22.6% (95% CI, 21.6%-23.6%) were alive but had stopped cART, 14.8% (95% CI, 14.0%-15.6%) had transferred to another clinic, 9.2% (95% CI, 8.5%-9.8%) were retained on cART, and 31.6% (95% CI, 30.6%-32.7%) could not been found. Mortality was associated with male sex, more advanced disease, and shorter cART duration; stopping cART with less advanced disease andlonger cART duration; and silent transfer with female sex and less advanced disease. CONCLUSIONS: Mortality in patients LTFU must be considered for unbiased assessments of program outcomes and UNAIDS targets in sub-Saharan Africa. Immediate start of cART and early tracing of patients LTFU should be priorities
Measurement of Azimuthal Asymmetries in Inclusive Production of Hadron Pairs in e+e- Annihilation at Belle
The Collins effect connects transverse quark spin with a measurable azimuthal
dependence in the yield of hadronic fragments around the quark's momentum
vector. Using two different reconstruction methods we observe statistically
significant azimuthal asymmetries for charged pion pairs in e+e- annihilation
at a center-of-mass energy of 10.52 GeV, which can be attributed to a
transverse polarization of the primordial quarks. The measurement was performed
using a sample of 79 million hadronic events collected with the Belle detector.Comment: 6 pages, 4 figure
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