Study of High-Transverse-Momentum Higgs Boson Production in Association with a Vector Boson in the qqbb Final State with the ATLAS Detector

This Letter presents the first study of Higgs boson production in association with a vector boson (V=W or Z) in the fully hadronic qqbb final state using data recorded by the ATLAS detector at the LHC in proton-proton collisions at sqrt[s]=13  TeV and corresponding to an integrated luminosity of 137  fb^{-1}. The vector bosons and Higgs bosons are each reconstructed as large-radius jets and tagged using jet substructure techniques. Dedicated tagging algorithms exploiting b-tagging properties are used to identify jets consistent with Higgs bosons decaying into bb[over ¯]. Dominant backgrounds from multijet production are determined directly from the data, and a likelihood fit to the jet mass distribution of Higgs boson candidates is used to extract the number of signal events. The VH production cross section is measured inclusively and differentially in several ranges of Higgs boson transverse momentum: 250-450, 450-650, and greater than 650 GeV. The inclusive signal yield relative to the standard model expectation is observed to be μ=1.4_{-0.9}^{+1.0} and the corresponding cross section is 3.1±1.3(stat)_{-1.4}^{+1.8}(syst)  pb.

Measurement of the Centrality Dependence of the Dijet Yield in p+Pb Collisions at sqrt[s_{NN}]=8.16 TeV with the ATLAS Detector

ATLAS measured the centrality dependence of the dijet yield using 165  nb^{-1} of p+Pb data collected at sqrt[s_{NN}]=8.16  TeV in 2016. The event centrality, which reflects the p+Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter. The central-to-peripheral ratio of the scaled dijet yields, R_{CP}, is evaluated, and the results are presented as a function of variables that reflect the kinematics of the initial hard parton scattering process. The R_{CP} shows a scaling with the Bjorken x of the parton originating from the proton, x_{p}, while no such trend is observed as a function of x_{Pb}. This analysis provides unique input to understanding the role of small proton spatial configurations in p+Pb collisions by covering parton momentum fractions from the valence region down to x_{p}∼10^{-3} and x_{Pb}∼4×10^{-4}.

Search for New Phenomena in Two-Body Invariant Mass Distributions Using Unsupervised Machine Learning for Anomaly Detection at sqrt[s]=13 TeV with the ATLAS Detector

Searches for new resonances are performed using an unsupervised anomaly-detection technique. Events with at least one electron or muon are selected from 140  fb^{-1} of pp collisions at sqrt[s]=13  TeV recorded by ATLAS at the Large Hadron Collider. The approach involves training an autoencoder on data, and subsequently defining anomalous regions based on the reconstruction loss of the decoder. Studies focus on nine invariant mass spectra that contain pairs of objects consisting of one light jet or b jet and either one lepton (e,μ), photon, or second light jet or b jet in the anomalous regions. No significant deviations from the background hypotheses are observed. Limits on contributions from generic Gaussian signals with various widths of the resonance mass are obtained for nine invariant masses in the anomalous regions.

"They Protect us as if they were our Mom" Masking Attitudes from Freelist Survey Data and Qualitative Interviews in San Diego School Communities

BACKGROUND

Despite being disproportionately impacted by COVID-19 due to a lack of structural support, marginalized communities have been largely ignored in the politically polarized debate over school masking. In response to this, we sought to explore masking attitudes by centering the voices of parents and children at historically marginalized, predominantly Hispanic schools in southern California.

METHODS

We conducted a mixed-methods study with parents and children attending 26 low-income predominantly Hispanic-serving elementary schools. A random sample of parents was asked to provide a freelist of words they associate with masking. A subset of parents with children aged 4-6 was recruited from these surveys to participate in parent-child interviews (PCI). We calculated Smith's salience index for all unique items, stratifying by language (English/Spanish). Item salience guided PCI thematic analysis for additional context and meaning.

RESULTS

648 participants provided 1118 unique freelist items in English and Spanish. 19 parent-child pairs were interviewed, 11 in Spanish and 8 in English. The most salient words were "safety"(0.37), "protection"(0.12), "prevention"(0.05), "health"(0.04), "good"(0.03), "can't breathe"(0.03), "necessary"(0.02), "care"(0.02), "precaution"(0.02), and "unnecessary"(0.02). Spanish speakers had a more favorable view of masking than English speakers, particularly regarding "protection" (0.20 vs 0.08) and "prevention" (0.10 vs 0.02).

DISCUSSION

Masking is an affordable individual-level risk mitigation that protects the communities that have inequitably shouldered the burdens of the COVID-19 pandemic. We recommend that policymakers prioritize the views of those most impacted when deciding on risk mitigation policies like school masking.

Observation of WZγ Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter reports the observation of WZγ production and a measurement of its cross section using 140.1±1.2  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. The WZγ production cross section, with both the W and Z bosons decaying leptonically, pp→WZγ→ℓ^{'}^{±}νℓ^{+}ℓ^{-}γ (ℓ^{(^{'})}=e, μ), is measured in a fiducial phase-space region defined such that the leptons and the photon have high transverse momentum and the photon is isolated. The cross section is found to be 2.01±0.30(stat)±0.16(syst)  fb. The corresponding standard model predicted cross section calculated at next-to-leading order in perturbative quantum chromodynamics and at leading order in the electroweak coupling constant is 1.50±0.06  fb. The observed significance of the WZγ signal is 6.3σ, compared with an expected significance of 5.0σ.

Combined Measurement of the Higgs Boson Mass from the H→γγ and H→ZZ^{*}→4ℓ Decay Channels with the ATLAS Detector Using sqrt[s]=7, 8, and 13 TeV pp Collision Data

A measurement of the mass of the Higgs boson combining the H→ZZ^{*}→4ℓ and H→γγ decay channels is presented. The result is based on 140  fb^{-1} of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11±0.09(stat)±0.06(syst)=125.11±0.11  GeV. This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics.

Search for Dark Photons in Rare Z Boson Decays with the ATLAS Detector

A search for events with a dark photon produced in association with a dark Higgs boson via rare decays of the standard model Z boson is presented, using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. The dark boson decays into a pair of dark photons, and at least two of the three dark photons must each decay into a pair of electrons or muons, resulting in at least two same-flavor opposite-charge lepton pairs in the final state. The data are found to be consistent with the background prediction, and upper limits are set on the dark photon's coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α_{D}ϵ^{2}, in the dark photon mass range of [5, 40] GeV except for the ϒ mass window [8.8, 11.1] GeV. This search explores new parameter space not previously excluded by other experiments.

Observation of Single-Top-Quark Production in Association with a Photon Using the ATLAS Detector

This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139  fb^{-1} of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688±23(stat) _{-71}^{+75}(syst)  fb, to be compared with the standard model prediction of 515_{-42}^{+36}  fb at next-to-leading order in QCD.

Measurement of Suppression of Large-Radius Jets and Its Dependence on Substructure in Pb+Pb Collisions at sqrt[s_{NN}]=5.02 TeV with the ATLAS Detector

This letter presents a measurement of the nuclear modification factor of large-radius jets in sqrt[s_{NN}]=5.02  TeV Pb+Pb collisions by the ATLAS experiment. The measurement is performed using 1.72  nb^{-1} and 257  pb^{-1} of Pb+Pb and pp data, respectively. The large-radius jets are reconstructed with the anti-k_{t} algorithm using a radius parameter of R=1.0, by reclustering anti-k_{t} R=0.2 jets, and are measured over the transverse momentum (p_{T}) kinematic range of 158 Collapse

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Measurement of the Sensitivity of Two-Particle Correlations in pp Collisions to the Presence of Hard Scatterings

A key open question in the study of multiparticle production in high-energy pp collisions is the relationship between the "ridge"-i.e., the observed azimuthal correlations between particles in the underlying event that extend over all rapidities-and hard or semihard scattering processes. In particular, it is not known whether jets or their soft fragments are correlated with particles in the underlying event. To address this question, two-particle correlations are measured in pp collisions at sqrt[s]=13  TeV using data collected by the ATLAS experiment at the LHC, with an integrated luminosity of 15.8  pb^{-1}, in two different configurations. In the first case, charged particles associated with jets are excluded from the correlation analysis, while in the second case, correlations are measured between particles within jets and charged particles from the underlying event. Second-order flow coefficients, v_{2}, are presented as a function of event multiplicity and transverse momentum. These measurements show that excluding particles associated with jets does not affect the measured correlations. Moreover, particles associated with jets do not exhibit any significant azimuthal correlations with the underlying event, ruling out hard processes contributing to the ridge.

Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector

A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[s]=13  TeV, corresponding to an integrated luminosity of 140  fb^{-1} recorded by the ATLAS experiment at LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, are studied. Backgrounds are estimated based on a hybrid approach involving Monte Carlo simulations and data-driven methods. Statistically significant excesses with respect to backgrounds dominated by the single parton scattering are seen in the di-J/ψ channel consistent with a narrow resonance at 6.9 GeV and a broader structure at lower mass. A statistically significant excess is also seen in the J/ψ+ψ(2S) channel. The fitted masses and decay widths of the structures are reported.

Observation of the γγ→ττ Process in Pb+Pb Collisions and Constraints on the τ-Lepton Anomalous Magnetic Moment with the ATLAS Detector

This Letter reports the observation of τ-lepton-pair production in ultraperipheral lead-lead collisions Pb+Pb→Pb(γγ→ττ)Pb and constraints on the τ-lepton anomalous magnetic moment a_{τ}. The dataset corresponds to an integrated luminosity of 1.44  nb^{-1} of LHC Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a τ-lepton decay, an electron or charged-particle track(s) from the other τ-lepton decay, little additional central-detector activity, and no forward neutrons. The γγ→ττ process is observed in Pb+Pb collisions with a significance exceeding 5 standard deviations and a signal strength of μ_{ττ}=1.03_{-0.05}^{+0.06} assuming the standard model value for a_{τ}. To measure a_{τ}, a template fit to the muon transverse-momentum distribution from τ-lepton candidates is performed, using a dimuon (γγ→μμ) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for a_{τ} is -0.057 Collapse

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Influence of plasma kinetic energy during the pulsed laser deposition of borophene films on silicon (100)

Developing borophene films with good structural stability on non-metallic substrates to maximize their potential in photosensitivity, gas detection, photothermia, energy storage, and deformation detection, among others has been challenging in recent years. Herein, we succeeded in the pulsed laser deposition of multilayered borophene films on Si (100) with β12 or χ3 bonding by tuning the mean kinetic energy in the plasma during the deposition process. Raman and X-ray photoelectron spectroscopies confirm β12 and χ3 bonding in the films. Borophene films with β12 bonding were obtained by tuning a high mean kinetic energy in the plasma, while borophene with χ3 bonding required a relatively low mean kinetic energy. Atomic force microscopy (AFM) micrographs revealed a granular and directional growth of the multilayered borophene films following the linear atomic terraces from the (100) silicon substrate. AFM nanofriction was used to access the borophene surfaces and to reveal the pull-off force and friction coefficient of the films where the surface oxide showed a significant contribution. To summarize, we show that it is possible to deposit multilayered borophene thin films with different bondings by tuning the mean kinetic energy during pulsed laser deposition. The characterization of the plasma during borophene deposition accompanies our findings, providing support for the changes in kinetic energy.

Strong Constraints on Jet Quenching in Centrality-Dependent p+Pb Collisions at 5.02 TeV from ATLAS

Jet quenching is the process of color-charged partons losing energy via interactions with quark-gluon plasma droplets created in heavy-ion collisions. The collective expansion of such droplets is well described by viscous hydrodynamics. Similar evidence of collectivity is consistently observed in smaller collision systems, including pp and p+Pb collisions. In contrast, while jet quenching is observed in Pb+Pb collisions, no evidence has been found in these small systems to date, raising fundamental questions about the nature of the system created in these collisions. The ATLAS experiment at the Large Hadron Collider has measured the yield of charged hadrons correlated with reconstructed jets in 0.36  nb^{-1} of p+Pb and 3.6  pb^{-1} of pp collisions at 5.02 TeV. The yields of charged hadrons with p_{T}^{ch}>0.5  GeV near and opposite in azimuth to jets with p_{T}^{jet}>30 or 60 GeV, and the ratios of these yields between p+Pb and pp collisions, I_{pPb}, are reported. The collision centrality of p+Pb events is categorized by the energy deposited by forward neutrons from the struck nucleus. The I_{pPb} values are consistent with unity within a few percent for hadrons with p_{T}^{ch}>4  GeV at all centralities. These data provide new, strong constraints that preclude almost any parton energy loss in central p+Pb collisions.

Search for Heavy Neutral Leptons in Decays of W Bosons Using a Dilepton Displaced Vertex in sqrt[s]=13 TeV pp Collisions with the ATLAS Detector

A search for a long-lived, heavy neutral lepton (N) in 139  fb^{-1} of sqrt[s]=13  TeV pp collision data collected by the ATLAS detector at the Large Hadron Collider is reported. The N is produced via W→Nμ or W→Ne and decays into two charged leptons and a neutrino, forming a displaced vertex. The N mass is used to discriminate between signal and background. No signal is observed, and limits are set on the squared mixing parameters of the N with the left-handed neutrino states for the N mass range 3  GeV Collapse

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Test of CP Invariance in Higgs Boson Vector-Boson-Fusion Production Using the H→γγ Channel with the ATLAS Detector

A test of CP invariance in Higgs boson production via vector-boson fusion has been performed in the H→γγ channel using 139  fb^{-1} of proton-proton collision data at sqrt[s]=13  TeV collected by the ATLAS detector at the LHC. The optimal observable method is used to probe the CP structure of interactions between the Higgs boson and electroweak gauge bosons, as described by an effective field theory. No sign of CP violation is observed in the data. Constraints are set on the parameters describing the strength of the CP-odd component in the coupling between the Higgs boson and the electroweak gauge bosons in two effective field theory bases: d[over ˜] in the HISZ basis and c_{HW[over ˜]} in the Warsaw basis. The results presented are the most stringent constraints on CP violation in the coupling between Higgs and weak bosons. The 95% C.L. constraint on d[over ˜] is derived for the first time and the 95% C.L. constraint on c_{HW[over ˜]} has been improved by a factor of 5 compared to the previous measurement.

TiO2/AgO composites by one step photo reduction technique as electron transport layers (ETL) for dye-sensitized solar cells

Dye-sensitized solar cell's electron transport layer is responsible for transporting photo-generated electrons to the outer circuit. Utilizing localized surface plasmon resonance (SPR), light absorption could be enhanced to a greater degree, which can drive dye molecules to excited state more effectively than far-field light. In this work, TiO₂ nanoparticles were prepared by solvothermal method, and Ag nanoparticles were decorated over TiO₂ surface through photodeposition method. XRD data of the TiO₂ sample exhibits anatase phase and in the Ag nanoparticle decorated TiO₂ sample, peaks corresponding to (111) planes of Ag was observed. UV-Vis absorption analysis of the TiO₂ and Ag decorated TiO₂ samples showed absorption in the UV region for the TiO_2, and the SPR effect was detected for the Ag deposited TiO₂ samples. Ag nanoparticles decorated over TiO₂ was observed to be spherical in shape through the images from transmission electron microscope. Presence of both Ag and AgO in the prepared sample was revealed through the data from X-ray photoelectron spectroscopy. The prepared material was used as photoanodes in the construction of the DSSCs, and their performance was evaluated.

Observation of WWW Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter reports the observation of WWW production and a measurement of its cross section using 139  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWW production cross section is measured to be 820±100 (stat)±80 (syst)  fb, approximately 2.6 standard deviations from the predicted cross section of 511±18  fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy.

A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery

The standard model of particle physics1-4 describes the known fundamental particles and forces that make up our Universe, with the exception of gravity. One of the central features of the standard model is a field that permeates all of space and interacts with fundamental particles5-9. The quantum excitation of this field, known as the Higgs field, manifests itself as the Higgs boson, the only fundamental particle with no spin. In 2012, a particle with properties consistent with the Higgs boson of the standard model was observed by the ATLAS and CMS experiments at the Large Hadron Collider at CERN10,11. Since then, more than 30 times as many Higgs bosons have been recorded by the ATLAS experiment, enabling much more precise measurements and new tests of the theory. Here, on the basis of this larger dataset, we combine an unprecedented number of production and decay processes of the Higgs boson to scrutinize its interactions with elementary particles. Interactions with gluons, photons, and W and Z bosons-the carriers of the strong, electromagnetic and weak forces-are studied in detail. Interactions with three third-generation matter particles (bottom (b) and top (t) quarks, and tau leptons (τ)) are well measured and indications of interactions with a second-generation particle (muons, μ) are emerging. These tests reveal that the Higgs boson discovered ten years ago is remarkably consistent with the predictions of the theory and provide stringent constraints on many models of new phenomena beyond the standard model.

Association between vitamin D deficiency and common variants of Vitamin D binding protein gene among Mexican Mestizo and indigenous postmenopausal women

PURPOSE

Vitamin D deficiency (VDD) and polymorphisms in the group-specific component (GC) gene are known to be associated in different populations. However, the effects of such genetic variants may vary across different populations. Thus, the objective of this study was to estimate the association between Vitamin D-Binding Protein (VDBP) haplotypes and VDD in mestizo postmenopausal women and Mexican Amerindian ethnic groups.

METHODS

This was a cross-sectional study of 726 postmenopausal Mexican women from the Health Workers Cohort Study (HWCS) and 166 postmenopausal women from the Metabolic Analysis in an Indigenous Sample (MAIS) cohort in Mexico. GC polymorphisms (rs7045 and rs4588) were analyzed by TaqMan probes. Serum 25-hydroxyvitamin D [25(OH)D] levels were measured by Chemiluminescent Microparticle Immuno Assay.

RESULTS

The prevalence of VDD serum 25(OH)D < 20 ng/mL was 43.7% in mestizo women and 44.6% in indigenous women. In HWCS, the single nucleotide polymorphisms (SNPs) rs7041 and rs4588 were associated with VDD. In addition, women from the HWCS, carrying the haplotypes GC2/2 and GC1f/2 had higher odds of VDD (OR = 2.83, 95% CI 1.14, 7.02; and OR = 2.30, 95% CI 1.40, 3.78, respectively) compared to women with haplotype 1f/1 s. These associations were not statistically significant in the MAIS cohort.

CONCLUSIONS

Our results show genetic association of the analyzed SNPs and related haplotypes, on the GC gene, with VDD in mestizo Mexican postmenopausal women. Moreover, a high prevalence of VDD with high genetic variability within the country was observed. Our results support the need for national policies for preventing VDD.

Self-assembled monolayer formation of pentamers-like molecules onto FCC(111) surfaces: the case of curcuminoids onto Au(111) surface

The adsorption of rigid straight electrically polarized pentamers over a FCC(111) surface is studied. The model was inspired by the deposition of 2-thiophene molecules over the Au(111) surface, which was previously characterized by experimental techniques and simulated under the frame of the density functional theory. We now obtain and report the charge distribution of the molecule which allows to propose a deposition model followed by Monte Carlo simulations over an ad-hoc lattice gas model. We show that for a certain value of the chemical potential there exists an isotropic-nematic phase transition which can explain the formation of a self-assembled monolayer like the one observed in the transmission electron microscopy images. An order parameter is defined to characterize the transition which presents a step-like behavior at a critical chemical potential value. The possible nature of the nematic transition in conjunction with an ergodicity breakdown is discussed as future work by means of statistical physics techniques.

'Desculturización,' urbanization, and nutrition transition among urban Kichwas Indigenous communities residing in the Andes highlands of Ecuador

BACKGROUND

The nutrition transition continues to affect populations throughout the world. The added impact of market integration and urbanization exacerbates the impact of the nutrition transition upon Indigenous populations worldwide.

OBJECTIVES

This study aims to explore the nutritional concerns of the urban Kichwas community residing in the Andes highlands of Ecuador.

STUDY DESIGN

This is a qualitative study.

METHODS

Eight focus groups were conducted with Kichwas men and women in November 2015 in the Imbabura province of the Andes in Ecuador.

DATA ANALYSIS

Applied thematic analysis was used to analyze findings regarding nutrition.

RESULTS

The participants shared concerns regarding increased intake of fast food, poor meal timing, and a shift in the child's food preferences that rejects traditional foods. They attributed these concerns to urbanization resulting from an increase in dual-income households and a loss of cultural identity.

CONCLUSIONS

Synergistic cultural factors are related to nutritional concerns voiced by the urban Kichwas community.

PUBLIC HEALTH IMPLICATIONS

Syndemic theory is a useful interpretive lens regarding nutritional trends within the Kichwas communities as they relate to the increased risk of chronic disease.

P5268Prognostic implications of cardiac magnetic resonance in patient with mid range ejection fraction: can we predict worse outcomes?

Purpose

According to current ESC guidelines, mid-range ejection fraction (mrEF) might represent a separate subgroup of patients with distinct underlying characteristics, prognosis and treatment response. Cardiac magnetic resonance (CMR) is the gold standard for measuring volumes, mass and ejection fraction of the heart. We aimed to find long-term prognostic value of various CMR parameters in patients mrEF.

Methods

137 patients with mrEF underwent CMR (1.5T) between 2012 and 2018 and were consecutively included. Volumes, mass and ejection fraction were assessed using short axis SSFP images and the Simpson method (using commercially available software). Myocardial fibrosis was determined by late gadolinium enhancement (LGE). Clinical parameters after a median of 762 (230–1315 days) were recorded. Patients with other significant cardiac affection rather than mrEF were excluded (pre-capillary pulmonary hypertension and significant valve disease). The primary endpoint was defined as a combined outcome of all-cause death or heart failure decompensation requiring in-hospital admission.

Results

Mean age was 63.0±12.4 years. 76.6% were males. Mean left ventricle ejection fraction (LVEF) was 45±2.69%. Main aetiologies were ischemic (46%), idiopathic (32.12%), myocarditis (9.5%), tachycardiomyopathy (6.57%) enolic (2.2%) stress cardiomyopathy (0.7%) and others (2.9%).

A combined model for predicting outcomes in patients with mrEF using CMR parameters was obtained. This model was able to predict 32.7% (coefficient of determination, R-squared) of the adverse events (p<0.01). Significant CMR parameters and results are shown on table 1.

Combined model for predicting outcomes in patients with mrEF using CMR parameters Variable p value iRVEDV (indexed right ventricular end-diastolic volume) <0.01 RVEF (right ventricle ejection fraction 0.03 iRVESV (indexed right ventricular end-systolic volume) <0.01 Presence of late enhancement (yes/no) 0.09 iLA (indexed left atrial) Volume <0.01 iLV (indexed left ventricle) mass <0.01 Variables and their significance are shown individually.

Conclusions

In patients with mid-range ejection fraction, RV volumes and ejection fraction, as well as LV mass and LA volume, were significant predictors of worse outcomes in a combined model. If supported by further studies, these findings may help the clinician select the patients with higher risk of complications and in need of a closer follow-up.

Risk and resiliency: the syndemic nature of HIV/AIDS in the indigenous highland communities of Ecuador

OBJECTIVES

This community-based study explores the syndemic nature of HIV/AIDS risk and resilience among Indigenous Kichwa communities in the province of Imbabura, Ecuador. This study elucidates individual and community-level factors that serve to exacerbate HIV/AIDS risk, as they relate to underlying macrolevel, structural forces. Critically, this study also elicited opportunities for community-based opportunities for resiliency from HIV/AIDS.

STUDY DESIGN

Exploratory qualitative study.

METHODS

Guided by syndemic theory, a qualitative study was conducted to explore HIV risk and resilience among Indigenous Kichwa communities in the Northern Andean highlands of Ecuador. Eight focus groups (n = 59) with men and women from two communities were conducted. The data were analyzed using applied thematic analysis techniques.

RESULTS

Identified risk factors for HIV/AIDS centered around the following themes: (1) parents leaving the community for work, (2) alcohol and drug consumption, (3) unprotected sex, and (4) barriers to health care. Identified HIV/AIDS resiliency factors included the preservation of Indigenous culture and family-focused interventions.

CONCLUSIONS

The identified risk factors for HIV/AIDS are interrelated within a complex syndemic relationship. The mutually reinforcing individual-level risk factors of substance abuse and risky sexual behavior coalesce with violence to exacerbate the risk for HIV/AIDS acquisition among Ecuadorian Highland Indigenous communities. Moreover, HIV/AIDS risk prevails in the macrolevel context of disproportionate unemployment among Indigenous peoples and a systematically fragmented healthcare system. It is critical that public health professionals work to revolutionize the systematic discrimination that underpins indigenous health disparities at-large.

Synthesis of salt-stable fluorescent nanoparticles (quantum dots) by polyextremophile halophilic bacteria

Here we report the biological synthesis of CdS fluorescent nanoparticles (Quantum Dots, QDs) by polyextremophile halophilic bacteria isolated from Atacama Salt Flat (Chile), Uyuni Salt Flat (Bolivia) and the Dead Sea (Israel). In particular, a Halobacillus sp. DS2, a strain presenting high resistance to NaCl (3-22%), acidic pH (1-4) and cadmium (CdCl2 MIC: 1,375 mM) was used for QDs biosynthesis studies. Halobacillus sp. synthesize CdS QDs in presence of high NaCl concentrations in a process related with their capacity to generate S2- in these conditions. Biosynthesized QDs were purified, characterized and their stability at different NaCl concentrations determined. Hexagonal nanoparticles with highly defined structures (hexagonal phase), monodisperse size distribution (2-5 nm) and composed by CdS, NaCl and cysteine were determined by TEM, EDX, HRXPS and FTIR. In addition, QDs biosynthesized by Halobacillus sp. DS2 displayed increased tolerance to NaCl when compared to QDs produced chemically or biosynthesized by non-halophilic bacteria. This is the first report of biological synthesis of salt-stable QDs and confirms the potential of using extremophile microorganisms to produce novel nanoparticles. Obtained results constitute a new alternative to improve QDs properties, and as consequence, to increase their industrial and biomedical applications.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

High-resolution imaging of photoreceptors in healthy human eyes using an adaptive optics retinal camera

PURPOSE

To determine the effects of age on perifoveal cone density in healthy subjects using adaptive optics.

METHODS

Healthy subjects of various ages were imaged using an adaptive optics retinal camera (RTX-1^® Imagine Eyes, Orsay, France). All patients underwent a comprehensive ophthalmologic examination and retinal imaging using spectral-domain optical coherence tomography (Spectralis^®, Heidelberg Engineering, Heidelberg, Germany). Cone density together with cone spacing and cone mosaic packing were measured in the nasal and temporal area 450 µm from the fovea. A multivariate analysis was performed to determine which of the following parameters were related to a decrease in cone density: age, axial length, central macular thickness, and retrofoveal choroidal thickness.

RESULTS

One hundred and sixty-seven eyes of 101 subjects aged 6-78 years were studied. Perifoveal cone density significantly decreased with age (R² = 0.17, p<0.01). Inversely, cone spacing increased with age (R²=0.18, p<0.01). There was no change in the cone packing mosaic (p>0.05). The mean coefficient of variation between fellow eyes was 3.9%. Age and axial length were related to a cone density decrease, while choroidal and retinal thicknesses did not affect cone metrics in healthy subjects.

CONCLUSIONS

A moderate perifoveal cone loss occurs with age. The precise consequences of these findings on visual function should be investigated. In addition to a better understanding of normal retinal anatomy, these results could act as a comparative database for further studies on normal and diseased retinas.

Descriptive study of ultrasound images of the upper airway obtained after insertion of laryngeal mask

OBJECTIVE

To evaluate clinical usefulness of ultrasound images of the upper airway in order to check correct laryngeal mask placement.

MATERIAL AND METHODS

A prospective observational study was conducted on patients scheduled for abdominal surgery under general anaesthesia, in whom the patency of the upper airway was ensured using an Ambu^®AuraGain^TM laryngeal mask. An ultrasound scan was performed of the upper-airway in the cranio-caudal direction and with longitudinal scans in the anterior midline and parasagittal axis, in three moments: before, after inserting and after removing the mask. All recorded images were evaluated in a second time by a radiologist-expert in upper airway ultrasound. Subsequently, the ultrasound data were related to the clinical difficulty of the insertion and presence of air leaks.

RESULTS

Data was collected from 30 patients (20 females and 10 males) being operated on for abdominal hysterectomy (15), eventroplasty (6), uterine myomectomy (3), and umbilical (4) and inguinal herniorrhaphy (2). The blind insertion of the masks did not present difficulties in 24 (80%) patients. Air leakage was detected in 8 (26.7%) patients, which was moderate in 7 cases and severe in one of them. The ultrasound findings confirmed good mask placement in 22 (73.3%) patients. Anatomical airway changes after laryngeal mask extraction were only observed in 3 (12%) patients, all of them minor. There was a statistically significant association (P<.05) between difficulty in inserting the device and the level of air leakage.

CONCLUSIONS

Upper airway ultrasound is a useful diagnostic method to evaluate laryngeal mask placement. Laryngeal oedema was not observed after removal of the device.

Anaesthetic management of a paediatric patient with congenital fibre type disproportion myopathy

Congenital fibre type disproportion (CFTD) is a rare type of myopathy that is characterised by muscle weakness and hypotonia during childhood. Clinical features include motor delay, feeding difficulties, limb weakness, joint contractures, and scoliosis. A report is presented of the anaesthetic management of a 3-year-old girl with CFTD myopathy associated with a mutation of the TPM3 gene, scheduled for adenotonsillectomy because of obstructive sleep apnoea hypopnoea syndrome (OSAHS). The main concerns were the possible susceptibility to malignant hyperthermia, the risk of anaesthesia-induced rhabdomyolysis, a greater sensitivity to non-depolarising muscle relaxants, and the presence of OSAHS. Total intravenous anaesthesia with propofol and the use of rocuronium/sugammadex appear to be safe options. Given the high risk of respiratory compromise and other complications, patients should be closely monitored in the post-operative period.

Mercury contamination level and speciation inventory in Lakes Titicaca & Uru-Uru (Bolivia): Current status and future trends

Aquatic ecosystems of the Bolivian Altiplano (∼3800 m a.s.l.) are characterized by extreme hydro-climatic constrains (e.g., high UV-radiations and low oxygen) and are under the pressure of increasing anthropogenic activities, unregulated mining, agricultural and urban development. We report here a complete inventory of mercury (Hg) levels and speciation in the water column, atmosphere, sediment and key sentinel organisms (i.e., plankton, fish and birds) of two endorheic Lakes of the same watershed differing with respect to their size, eutrophication and contamination levels. Total Hg (THg) and monomethylmercury (MMHg) concentrations in filtered water and sediment of Lake Titicaca are in the lowest range of reported levels in other large lakes worldwide. Downstream, Hg levels are 3-10 times higher in the shallow eutrophic Lake Uru-Uru than in Lake Titicaca due to high Hg inputs from the surrounding mining region. High percentages of MMHg were found in the filtered and unfiltered water rising up from <1 to ∼50% THg from the oligo/hetero-trophic Lake Titicaca to the eutrophic Lake Uru-Uru. Such high %MMHg is explained by a high in situ MMHg production in relation to the sulfate rich substrate, the low oxygen levels of the water column, and the stabilization of MMHg due to abundant ligands present in these alkaline waters. Differences in MMHg concentrations in water and sediments compartments between Lake Titicaca and Uru-Uru were found to mirror the offset in MMHg levels that also exist in their respective food webs. This suggests that in situ MMHg baseline production is likely the main factor controlling MMHg levels in fish species consumed by the local population. Finally, the increase of anthropogenic pressure in Lake Titicaca may probably enhance eutrophication processes which favor MMHg production and thus accumulation in water and biota.

Reply #1 to: Glycemic Choreoballism

In Response To: Lee D, Ahn TB. Glycemic choreoballism. Tremor Other Hyperkinet Mov. 2016; 6. doi: 10.7916/D8QJ7HNF Original Article: Cosentino C, Torres L, Nuñez Y, et al. Hemichorea/hemiballism associated with hyperglycemia: report of twenty cases. Tremor Other Hyperkinet Mov. 2016; 6. doi: 10.7916/D8DN454P.

Hemichorea/Hemiballism Associated with Hyperglycemia: Report of 20 Cases

Background

Hemichorea/hemiballism associated with nonketotic hyperglycemia is a well-recognized syndrome, but few case series have been reported in the literature.

Case Report

We describe 20 patients with hemichorea/hemiballism associated with hyperglycemia (9 males and 11 females) with mean age of 67.8 years. Ten patients had a previous diagnosis of type 2 diabetes mellitus, and one had type 1 diabetes mellitus. Six of them had documentation of poor diabetic control over at least the last 3 months. Nine patients had new-onset hyperglycemia with a diagnosis of diabetes mellitus made after discharge. Seventeen patients had unilateral chorea/ballism, while three had bilateral chorea/ballism. Eighteen cases had striatal hyperdensities on computed tomography (CT) and/or hyperintense signals on magnetic resonance imaging (MRI). The putamen was affected in all cases, and the caudate nucleus was involved in nine.

Discussion

Hemichorea/hemiballism associated with nonketotic hyperglycemia can be the presenting sign of diabetes mellitus in almost half of cases or can occur after a few months of poor glycemic control in patients with diagnosed diabetes. This case series is one of the largest to date and adds valuable information about clinical and neuroimaging features that are comparable with published data but also emphasize the role of adequate diabetes mellitus control.

Bilateral Hypertrophic Olivary Degeneration and Holmes Tremor without Palatal Tremor: An Unusual Association

BACKGROUND

Lesions in the Guillain-Mollaret triangle or dentate-rubro-olivary pathway may lead to hypertrophic olivary degeneration (HOD), a secondary trans-synaptic degeneration of the inferior olivary nucleus. HOD is usually associated with palatal tremor and rarely with Holmes tremor. Bilateral HOD is a very unusual condition and very few cases are reported.

CASE REPORT

We report here two cases of bilateral HOD after two different vascular lesions located at the decussation of superior cerebellar peduncles, thus impairing both central tegmental tracts and interrupting bilaterally the dentate-rubral-olivary pathway. Interestingly, both developed bilateral Holmes tremor but not palatal tremor.

DISCUSSION

Lesions in some of the components in the Guillain-Mollaret triangle may develop Holmes tremor with HOD and without palatal tremor. Magnetic resonance imaging is an invaluable tool in these cases. Better understanding of the pathways in this loop is needed.

An easy synthetic way to exfoliate and stabilize MWCNTs in a thermoplastic pyrrole-containing matrix assisted by hydrogen bonds

MWCNTs were dispersed in a thermoplastic polymer containing pyrrole units in the main chain and hydroxyl pendant groups, affording a well-distributed percolative network. The resulting soft nanocomposite shows stable conductive behavior.

Development and assessment of the disposition index based on the oral glucose tolerance test in subjects with different glycaemic status

Insulin secretion and insulin sensitivity indexes are related by hyperbolic functions, allowing the calculation of the disposition index (DI) as the product of the acute insulin response (AIR) and the insulin sensitivity index (Si) from intravenous glucose tolerance test (IVGTT). Our objective was to develop an oral-DI based on the oral glucose tolerance test (OGTT) and to assess its association with glucose tolerance status. This research is structured in three studies. Study 1: OGTT were performed in 833 non-diabetic Chilean women (18-60 years) without family history of diabetes mellitus. Study 2: an independent group of n = 57 non-diabetic (18-46 years) without family history of diabetes mellitus carried out an OGTT and an abbreviated IVGTT. Study 3: a sample of 1674 Chilean adults (18-60 years) with different glycaemic status performed an OGTT. An adequate statistical fit for a rectangular hyperbola was found between the area under the curve of insulin-to-glucose ratio (AUCI/G-R) and the Matsuda ISI-COMP index (study 1). The oral-DI derived as AUCI/G-R × ISI-COMP was previously termed insulin-secretion-sensitivity index-2 (ISSI-2). ISSI-2 significantly correlated with DI from IVGTT (rho = 0.34; p = 0.009) (study 2). ISSI-2 shows important differences across groups of subjects with different glycaemic status (study 3). We have confirmed that ISSI-2 replicates the mathematical properties of DI, showing significant correlations with DI from the abbreviated MM-IVGTT. These results indicate that ISSI-2 constitutes a surrogate measure of insulin secretion relative to insulin sensitivity and emphasizes the pivotal role of impaired insulin secretion in the development of glucose homeostasis dysregulation.