Pygmies, Giants, and Skins

Understanding the equation of state (EOS) of neutron-rich matter is a central goal of nuclear physics that cuts across a variety of disciplines. Indeed, the limits of nuclear existence, the collision of energetic heavy ions, the structure of neutron stars, and the dynamics of core-collapse supernova all depend critically on the nuclear-matter EOS. In this contribution I focus on the EOS of cold baryonic matter with special emphasis on its impact on the structure, dynamics, and composition of neutron stars. In particular, I discuss how laboratory experiments on neutron skins as well as on Pygmy and Giant resonances can help us elucidate the structure of these fascinating objects.Comment: Invited Talk given at the 11th International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference Series (JPCS

Do we understand the incompressibility of neutron-rich matter?

The ``breathing mode'' of neutron-rich nuclei is our window into the incompressibility of neutron-rich matter. After much confusion on the interpretation of the experimental data, consistency was finally reached between different models that predicted both the distribution of isoscalar monopole strength in finite nuclei and the compression modulus of infinite matter. However, a very recent experiment on the Tin isotopes at the Research Center for Nuclear Physics(RCNP) in Japan has again muddled the waters. Self-consistent models that were successful in reproducing the energy of the giant monopole resonance (GMR) in nuclei with various nucleon asymmetries (such as 90Zr, 144Sm, and 208Pb) overestimate the GMR energies in the Tin isotopes. As important, the discrepancy between theory and experiment appears to grow with neutron excess. This is particularly problematic as models artificially tuned to reproduce the rapid softening of the GMR in the Tin isotopes become inconsistent with the behavior of dilute neutron matter. Thus, we regard the question of ``why is Tin so soft?'' as an important open problem in nuclear structure.Comment: 12 pages, 3 figures, and 1 table. Submitted to the "Focus issue on Open Problems in Nuclear Structure", Journal of Physics

Remote multiparametric monitoring and management of heart failure patients through cardiac implantable electronic devices

In this review we focus on heart failure (HF) which, as known, is associated with a substantial risk of hospitalizations and adverse cardiovascular outcomes, including death. In recent years, systems to monitor cardiac function and patient parameters have been developed with the aim to detect subclinical pathophysiological changes that precede worsening HF. Several patient-specific parameters can be remotely monitored through cardiac implantable electronic devices (CIED) and can be combined in multiparametric scores predicting patients’ risk of worsening HF with good sensitivity and moderate specificity. Early patient management at the time of pre-clinical alerts remotely transmitted by CIEDs to physicians might prevent hospitalizations. However, it is not clear yet which is the best diagnostic pathway for HF patients after a CIED alert, which kind of medications should be changed or escalated, and in which case in-hospital visits or in-hospital admissions are required. Finally, the specific role of healthcare professionals involved in HF patient management under remote monitoring is still matter of definition. We analyzed recent data on multiparametric monitoring of patients with HF through CIEDs. We provided practical insights on how to timely manage CIED alarms with the aim to prevent worsening HF. We also discussed the role of biomarkers and thoracic echo in this context, and potential organizational models including multidisciplinary teams for remote care of HF patients with CIEDs

Acción del análogo tumoral de PTH (PTHrP) en la regulación de factores asociados al fenotipo invasivo y a la angiogénesis en células de cáncer de colon humano

El péptido relacionado con la hormona paratiroidea (PTHrP) está implicado en varios cánceres humanos, entre los que se encuentra el cáncer colorrectal (CCR). Esta patología implica varios procesos, como mayor supervivencia celular, proliferación, migración, invasión, transición epitelio-mesenquimática (TEM) y angiogénesis. Previamente encontramos que PTHrP induce la proliferación, supervivencia y migración de células Caco-2 y HCT116, dos líneas celulares de tumores de colon humano. La invasión celular durante la progresión del cáncer se ha asociado a la pérdida de características epiteliales, la remodelación de la matriz extracelular, y el desarrollo de vascularización, por lo que abordar estos procesos es de relevancia para entender el rol de PTHrP en la enfermedad y constituye el objetivo de este trabajo. Se observó que el tratamiento con PTHrP 10-8 M en estas células aumenta los niveles de ARNm de la metaloproteinasa de la matriz 7 (MMP-7) y la expresión proteica de la proteína ácida y rica en cisteína SPARC, dos proteínas que participan en la reestructuración del estroma y que están fuertemente implicadas en la invasión tumoral. Además el tratamiento con PTHrP disminuyó los niveles proteicos de citoqueratina-18 (CK-18) un marcador epitelial asociado con TEM mediante Western blot e Inmunocitoquímica. Los niveles del factor de crecimiento endotelial vascular (VEGF), del factor inducible por hipoxia 1α (HIF-1α) y de la metaloproteinasa de la matriz 9 (MMP-9) por RT-qPCR mostraron que PTHrP aumenta la transcripción de estos factores implicados en la angiogénesis tumoral. Estos resultados sugieren un nuevo rol de PTHrP en la regulación de fenómenos asociados a un fenotipo más agresivo de células derivadas de cáncer colorrectalFil: Carriere, P.. Universidad Nacional del Sur.Fil: Riquelme, A.N.. Universidad Nacional del Sur.Fil: Novoa Díaz, M.B.. Universidad Nacional del Sur.Fil: Calvo, N. . Universidad Nacional del Sur.Fil: Gentili, C.. Universidad Nacional del Sur

Tokenizzazione di azioni e azioni tokens

Il lavoro analizza il fenomeno della rappresentazione delle partecipazioni azionarie in tokens e delle azioni tokens native. Dopo una breve illustrazione della circolazione della ric- chezza nella tecnologia a registro distribuito (distributed ledger technology, c.d. DLT), lo studio esamina la nozione di cripto-attività e la relativa tassonomia, come elaborate dalla proposta di Regolamento (UE) MiCA (Market in Crypto-Asset), evidenziando le criticità di inquadramento. L’attenzione si sofferma altresì sulle verosimili ripercussioni dell’approvazione del Regolamento (UE) 2022/858 relativo a un regime pilota. Successivamente il contributo approfondisce le cripto-attività nella prospettiva societaria mediante una valutazione di assimilabilità dei security tokens ai tradizionali strumenti finanziari e svolge una distinzione tra security tokens e utility tokens e tra utility tokens e NFT (non-fungible tokens). Muovendo da una ricostruzione delle tecniche di legittimazione e circolazione delle partecipazioni sociali previste dal Codice civile, il testo delinea la possibilità di rappresentare, de iure condito, azioni, quote o altri strumenti so- cietari su DLT e ne valuta la compatibilità con il quadro giuridico vigente. In conclusione, il lavoro formula alcune proposte de iure condendo per l’applicazione della tecnologia DLT nelle infra- strutture di mercato

Low-cost electrochemical detection of arsenic in the groundwater of Guanajuato state, central Mexico using an open-source potentiostat

Arsenic is a carcinogenic groundwater contaminant that is toxic even at the parts-per-billion (ppb) level and its on-site determination remains challenging. Colorimetric test strips, though cheap and widely used, often fail to give reliable quantitative data. On the other hand, electrochemical detection is sensitive and accurate but considerably more expensive at the onset. Here, we present a study on arsenic detection in groundwater using a low-cost, open-source potentiostat based on Arduino technology. We tested different types of gold electrodes (screen-printed and microwire) with anodic stripping voltammetry (ASV), achieving low detection limits (0.7 μg L(-1)). In a study of arsenic contaminated groundwaters in Mexico, the microwire technique provides greater accuracy than test strips (reducing the median error from -50% to +2.9%) and greater precision (reducing uncertainties from ±25% to ±4.9%). Most importantly, the rate of false negatives versus the World Health Organisation’s 10 μg L(-1) limit was reduced from 50% to 0% (N = 13 samples). Arsenic determination using open-source potentiostats may offer a low-cost option for research groups and NGOs wishing to perform arsenic analysis in-house, yielding superior quantitative data than the more widely used colorimetric test strips

Fluoromycobacteriophages for rapid, specific, and sensitive antibiotic susceptibility testing of Mycobacterium tuberculosis

Rapid antibiotic susceptibility testing of Mycobacterium tuberculosis is of paramount importance as multiple- and extensively- drug resistant strains of M. tuberculosis emerge and spread. We describe here a virus-based assay in which fluoromycobacteriophages are used to deliver a GFP or ZsYellow fluorescent marker gene to M. tuberculosis, which can then be monitored by fluorescent detection approaches including fluorescent microscopy and flow cytometry. Pre-clinical evaluations show that addition of either Rifampicin or Streptomycin at the time of phage addition obliterates fluorescence in susceptible cells but not in isogenic resistant bacteria enabling drug sensitivity determination in less than 24 hours. Detection requires no substrate addition, fewer than 100 cells can be identified, and resistant bacteria can be detected within mixed populations. Fluorescence withstands fixation by paraformaldehyde providing enhanced biosafety for testing MDR-TB and XDR-TB infections. © 2009 Piuri et al

Comparative study of in situ N2 rotational Raman spectroscopy methods for probing energy thermalisation processes during spin-exchange optical pumping

Spin-exchange optical pumping (SEOP) has been widely used to produce enhancements in nuclear spin polarisation for hyperpolarised noble gases. However, some key fundamental physical processes underlying SEOP remain poorly understood, particularly in regards to how pump laser energy absorbed during SEOP is thermalised, distributed and dissipated. This study uses in situ ultra-low frequency Raman spectroscopy to probe rotational temperatures of nitrogen buffer gas during optical pumping under conditions of high resonant laser flux and binary Xe/N2 gas mixtures. We compare two methods of collecting the Raman scattering signal from the SEOP cell: a conventional orthogonal arrangement combining intrinsic spatial filtering with the utilisation of the internal baffles of the Raman spectrometer, eliminating probe laser light and Rayleigh scattering, versus a new in-line modular design that uses ultra-narrowband notch filters to remove such unwanted contributions. We report a ~23-fold improvement in detection sensitivity using the in-line module, which leads to faster data acquisition and more accurate real-time monitoring of energy transport processes during optical pumping. The utility of this approach is demonstrated via measurements of the local internal gas temperature (which can greatly exceed the externally measured temperature) as a function of incident laser power and position within the cell