Letter to the Editor Concerning Simultaneous, Single-Particle Measurements of Size and Loading Give Insights into the Structure of Drug-Delivery Nanoparticles

The vexing error of excess variance in the sizing of single particles degrades accuracy in applications ranging from quality control of nanoparticle products to hazard assessment of nanoplastic byproducts. The particular importance of lipid nanoparticles for vaccine and medicine delivery motivates this comment on a publication$^{\textrm{1}}$ in ACS Nano. In ref 1, the benchmark measurements of a nanoparticle standard manifest large errors of the size distribution that contradict the claim of validation. Such errors can bias the correlation of fluorescence intensity as an optical proxy for the molecular loading of lipid nanoparticles and give misleading insights from power-law models of intensity$-$size data. Looking forward, measurement error models have the potential to address this widespread issue.Comment: Peer reviewed and pending acceptance by ACS Nan

Una aproximación a la identificación de paisajes urbanos históricos

Como aporte al desarrollo del Proyecto “La Plata, Paisaje Cultural”, el grupo de trabajo conformado por los arquitectos María Marta Aversa, Natalia Bertone, Talía Salomone, Roberto Delage y Marianela Novoa Farkas, bajo la dirección de la Mgr. Arq. Cristina Vitalone, trabajó sobre la Región Capital de la provincia de Buenos Aires, con la finalidad de contribuir a la re construcción del proceso perceptivo integral de su territorio, a partir de la identificación de los paisajes urbanos históricos, culturalmente más significativos, de su frente fluvial, de las áreas urbano-portuarias e islas, de las interfases urbanas y de la movilidad, centrada en la redes ferroviarias. Esta aproximación se sustenta en la comprensión de que La Plata, es la ciudad más importante de un sistema las centros urbanos que, más allá de pertenecer a tres municipios La Plata, Berisso y Ensenada, conforman una región de interdependencias múltiples espacio-temporales, físico-funcionales, socio-culturales, económico-financieras y político- jurisdiccionales. Un escenario que nació a fines del siglo XIX con la fundación de una ciudad nueva (1882) y el potenciamiento de su dinamismo económico con la construcción científica de un puerto natural, ambos hechos que determinaron el proceso de ocupación, poblamiento y organización plena de un territorio a escala regional. También en su concepción de Ciudad Planificada que incluyó al extenso territorio que la circundaba para cumplir con los roles que le tocaba asumir: Ciudad Capital, Ciudad con Puerto, Ciudad de los Poderes Públicos, Ciudad Universitaria, Ciudad Moderna, Ciudad Higiénica…, determinantes tanto de la concepción como del emplazamiento del trazado urbano del casco fundacional. En esta escala, el valor simbólico de la Ciudad Planificada comienza en el ordenamiento de su propio Ejido y, específicamente, en tres de los elementos de su paradigmático trazado urbano que estructuraron el unívoco espacio regional hasta 1957: un eje urbano-portuario-monumental que nacía en el puerto, plataforma de transporte fluvial, conteniendo la edilicia más representativa de los avances tecnológicos en producción de energías, los gobiernos, local y provincial, la seguridad, la cultura, la educación y el culto hasta concluir, en origen, en otra plataforma de transporte terrestre-ferrovial; un boulevard de circunvalación entre el casco urbano fundacional y su periferia de quintas y chacras, y un bosque, puerta va y viene entre ciudad y región, todos a la vez, referentes espaciales, funcionales e históricos de la memoria colectiva de sus habitantes. En ese contexto, los autores reflexionan sobre la necesidad de entre otras acciones: • valorizar y proteger los bienes patrimoniales, naturales y culturales, tangibles e intangibles, que contribuyan a estimular el sentido de pertenencia a una misma región; • recuperar y ampliar los espacios libres y construidos que, en conjunto, refuercen la infraestructura socio-cultural en pos de mejorar la calidad de las áreas urbanas, de vida de sus habitantes y la atractividad del territorio regional. • promover un itinerario cultural a escala regional que relacione armónicamente nuevas intervenciones físicas, espaciales, funcionales y ambientales con el entramado urbano histórico preexistente. • inducir acciones de recuperación y/o construcción de nexos físico-funcionales-ambientales entre la Ciudad Capital, el Frente Fluvial, las áreas Urbano-Portuarias y de Islas y sus Interfases Urbanas, con la reactivación del ferrocarril, la introducción de nuevos medios de transporte público, la construcción de bici sendas y peatonales, de abras y recorridos de vinculación sensorial con paisajes múltiples y, entre otras, con la apertura del Canal Oeste al transporte fluvial recreativo.El documento aporta al conocimiento de la Región Capital de la provincia de Buenos Aires teniendo en cuenta los paisajes urbanos históricos más significativos del territorio integrado por tres municipios, La Plata, Berisso y Ensenada. Es resultado de la primera fase de un proyecto de investigación, en desarrollo, inscrito en el Programa Res. CIC 2002-99 "Planificación y Gestión Estratégica Urbana y Territorial" con sede en el Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica de la Comisión de Investigaciones Científicas de la Provincia de Buenos Aires

Psycho-social factors associated with mental resilience in the Corona lockdown.

The SARS-CoV-2 pandemic is not only a threat to physical health but is also having severe impacts on mental health. Although increases in stress-related symptomatology and other adverse psycho-social outcomes, as well as their most important risk factors have been described, hardly anything is known about potential protective factors. Resilience refers to the maintenance of mental health despite adversity. To gain mechanistic insights about the relationship between described psycho-social resilience factors and resilience specifically in the current crisis, we assessed resilience factors, exposure to Corona crisis-specific and general stressors, as well as internalizing symptoms in a cross-sectional online survey conducted in 24 languages during the most intense phase of the lockdown in Europe (22 March to 19 April) in a convenience sample of N = 15,970 adults. Resilience, as an outcome, was conceptualized as good mental health despite stressor exposure and measured as the inverse residual between actual and predicted symptom total score. Preregistered hypotheses (osf.io/r6btn) were tested with multiple regression models and mediation analyses. Results confirmed our primary hypothesis that positive appraisal style (PAS) is positively associated with resilience (p < 0.0001). The resilience factor PAS also partly mediated the positive association between perceived social support and resilience, and its association with resilience was in turn partly mediated by the ability to easily recover from stress (both p < 0.0001). In comparison with other resilience factors, good stress response recovery and positive appraisal specifically of the consequences of the Corona crisis were the strongest factors. Preregistered exploratory subgroup analyses (osf.io/thka9) showed that all tested resilience factors generalize across major socio-demographic categories. This research identifies modifiable protective factors that can be targeted by public mental health efforts in this and in future pandemics

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

Peer reviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Observation of tW production in the single-lepton channel in pp collisions at root s=13 TeV

A measurement of the cross section of the associated production of a single top quark and a W boson in final states with a muon or electron and jets in proton-proton collisions at root s = 13 TeV is presented. The data correspond to an integrated luminosity of 36 fb(-1) collected with the CMS detector at the CERN LHC in 2016. A boosted decision tree is used to separate the tW signal from the dominant t (t) over bar background, whilst the subleading W+jets and multijet backgrounds are constrained using data-based estimates. This result is the first observation of the tW process in final states containing a muon or electron and jets, with a significance exceeding 5 standard deviations. The cross section is determined to be 89 +/- 4 (stat) +/- 12 (syst) pb, consistent with the standard model.Peer reviewe

Measurement of the top quark mass using events with a single reconstructed top quark in pp collisions at root s=13 TeV

Abstract:A measurement of the top quark mass is performed using a data sample en-riched with single top quark events produced in thetchannel. The study is based on proton-proton collision data, corresponding to an integrated luminosity of 35.9 fb−1, recorded at√s= 13TeV by the CMS experiment at the LHC in 2016. Candidate events are selectedby requiring an isolated high-momentum lepton (muon or electron) and exactly two jets,of which one is identified as originating from a bottom quark. Multivariate discriminantsare designed to separate the signal from the background. Optimized thresholds are placedon the discriminant outputs to obtain an event sample with high signal purity. The topquark mass is found to be172.13+0.76−0.77GeV, where the uncertainty includes both the sta-tistical and systematic components, reaching sub-GeV precision for the first time in thisevent topology. The masses of the top quark and antiquark are also determined separatelyusing the lepton charge in the final state, from which the mass ratio and difference aredetermined to be0.9952+0.0079−0.0104and0.83+1.79−1.35GeV, respectively. The results are consistentwithCPTinvariance

Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at root s=13 TeV

Measurements of Higgs boson production cross sections and couplings in events where the Higgs boson decays into a pair of photons are reported. Events are selected from a sample of proton-proton collisions at root s = 13TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137 fb(-1). Analysis categories enriched in Higgs boson events produced via gluon fusion, vector boson fusion, vector boson associated production, and production associated with top quarks are constructed. The total Higgs boson signal strength, relative to the standard model (SM) prediction, is measured to be 1.12 +/- 0.09. Other properties of the Higgs boson are measured, including SM signal strength modifiers, production cross sections, and its couplings to other particles. These include the most precise measurements of gluon fusion and vector boson fusion Higgs boson production in several different kinematic regions, the first measurement of Higgs boson production in association with a top quark pair in five regions of the Higgs boson transverse momentum, and an upper limit on the rate of Higgs boson production in association with a single top quark. All results are found to be in agreement with the SM expectations.Peer reviewe