Espacios sagrados en el mundo andino. Excavación de una huanca en Las Pailas (Cachi, Salta, Argentina)

En el mundo andino prehispánico, el estudio de las prácticas agrícolas requiere abordar el universo social y simbólico que constituye la matriz de significado,considerando que el espacio natural y social no son elementos indisociados dentro de la cosmovisión de los grupos. En este marco, nos proponemos analizar el registro material vinculado a las prácticas rituales en el sitio arqueológico de Las Pailas (Cachi, Salta). Para ello se excavó una estructura con singularidades arquitectónicas cuyo registro artefactual indicaría que allí se habrían desarrollado actividades de carácter festivo-ritual.Fil: Paez, Maria Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Arqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Lynch, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Arqueología; ArgentinaFil: Besa, Yamila. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Arqueología; Argentin

Espacios sagrados en el mundo andino : Excavación de una <i>huanca</i> en Las Pailas (Cachi, Salta, Argentina)

El estudio de las prácticas rituales materializadas en las huancas debe comprenderse en el marco de un interés más amplio que compete a la interpretación de la vida campesina en tiempos prehispánicos. Para las sociedades andinas, la vida campesina está intersectada cotidianamente por un fuerte simbolismo y ritualidad que es intrínseco a cada una de las actividades relacionadas con lo agrícola. Por tanto, la comprensión de la dimensión simbólica se torna fundamental para abordar las prácticas campesinas de este sector de Los Andes en tiempos prehispánicos. La literatura andina destaca la presencia de marcadores de piedra con una función relacionada al culto de los ancestros y la fertilidad de las tierras para el área andina (Duviols 1978, 1979). Este registro podría relacionarse con aquellas interpretaciones que consideran que la ritualidad que envuelve las prácticas campesinas habría representado una parte sustancial para el fortalecimiento y la reproducción del territorio comunal en su cartografía física y sagrada (Pérez Galán 2010). Es así que en este trabajo nos proponemos presentar y discutir la excavación de una estructura de piedra sobre la que se puede inferir una funcionalidad vinculada a la órbita de lo sagrado. Las interpretaciones realizadas se enmarcan y complementan con un registro de similar naturaleza para el sitio arqueológico de Las Pailas (Cachi, Salta).Facultad de Ciencias Naturales y Muse

Las Pailas agricultural fields (Cachi, Salta)

El sitio arqueológico Las Pailas constituye uno de los enclaves agrícolas de mayor importancia en el Valle Calchaquí Norte. Incluye 500 hectáreas de campos agrícolas irrigados por una amplia red de canales, con características que hacen suponer una ocupación continua desde los inicios del Primer Milenio de la era cristiana. Las prospecciones realizadas en los últimos años han permitido detectar una nueva área de cultivo denominada Las Pailas 2, la cual está espacialmente vinculada al sector 1 y muy similar en lo que hace a la estructura del espacio agrícola. A pesar de la vastedad de la extensión agrícola de la región, su estudio ha sido relegado dentro de las investigaciones. La reanudación de los trabajos ha permitido ampliar el conocimiento sobre el vínculo que estas sociedades habrían mantenido con la tierra, las características del cultivo en el sitio y el tipo de estrategias hidráulicas desarrolladas para asegurar la productividad agrícola. En muchos casos, éstos encuentran importantes puntos de anclaje con las prácticas campesinas de los actuales pobladores locales de esta porción de los Andes Meridionales.The archaeological site of Las Pailas is one of the most important agricultural enclaves in the North Calchaquí Valley. It includes 500 hectares of farmland irrigated by a network of canals, a characteristic which leads us to think that the place was settled since the beginning of the First Millennium AD. Research carried out in the past few years has identified a new cultivation area, Las Pailas 2, which is spacially linked to Las Pailas 1. It is supposed to be related to the former and it is very similar regarding the structure of agricultural land. Despite the vastness of the agricultural extension of the region, its study seems to have been relegated to secondary research. The resumption of exploration has improved knowledge and raised awareness of the relationship between ancient societies with their land, the features of the kind of farming carried out, and the type of hydraulic strategies developed to ensure agricultural production. In many cases the former aspects, are important connections to the current farming practices of local people living in this portion of the southern Andes nowadays.Facultad de Ciencias Naturales y Muse

The impact of arterial input function determination variations on prostate dynamic contrast-enhanced magnetic resonance imaging pharmacokinetic modeling: a multicenter data analysis challenge, part II

This multicenter study evaluated the effect of variations in arterial input function (AIF) determination on pharmacokinetic (PK) analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data using the shutter-speed model (SSM). Data acquired from eleven prostate cancer patients were shared among nine centers. Each center used a site-specific method to measure the individual AIF from each data set and submitted the results to the managing center. These AIFs, their reference tissue-adjusted variants, and a literature population-averaged AIF, were used by the managing center to perform SSM PK analysis to estimate Ktrans (volume transfer rate constant), ve (extravascular, extracellular volume fraction), kep (efflux rate constant), and τi (mean intracellular water lifetime). All other variables, including the definition of the tumor region of interest and precontrast T1 values, were kept the same to evaluate parameter variations caused by variations in only the AIF. Considerable PK parameter variations were observed with within-subject coefficient of variation (wCV) values of 0.58, 0.27, 0.42, and 0.24 for Ktrans, ve, kep, and τi, respectively, using the unadjusted AIFs. Use of the reference tissue-adjusted AIFs reduced variations in Ktrans and ve (wCV = 0.50 and 0.10, respectively), but had smaller effects on kep and τi (wCV = 0.39 and 0.22, respectively). kep is less sensitive to AIF variation than Ktrans, suggesting it may be a more robust imaging biomarker of prostate microvasculature. With low sensitivity to AIF uncertainty, the SSM-unique τi parameter may have advantages over the conventional PK parameters in a longitudinal study

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Caso cl\uednico-radiol\uf3gico

Caso Cl\uednico Reci\ue9n nacido var\uf3n, producto de un embarazo normal, nacido por parto vaginal, 2 900 g de peso, APGAR 8-9, edad gestacional 36 semanas. Al nacer el examen cl\uednico era normal. Se adapta r\ue1pidamente al pecho materno y presenta tr\ue1nsito intestinal normal. Al segundo d\ueda de vida, presenta m\uednima distensi\uf3n abdominal por lo que se solicita radiograf\ueda (Rx) simple de abdomen con proyecciones anteroposterior (AP) (Figura 1a) y lateral en dec\ufabito dorsal y con rayo horizontal (Figura 1b)..

IVIM diffusion-weighted imaging of the liver at 3.0 T: Comparison with 1.5 T

Purpose: To compare intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) of the liver between 1.5 T and 3.0 T in terms of parameter quantification and inter-platform reproducibility. Materials and methods: In this IRB approved prospective study, 19 subjects (17 patients with chronic liver disease and 2 healthy volunteers) underwent two repeat scans at 1.5 T and 3.0 T. Each scan included IVIM DWI using 16 b values from 0 to 800 s/mm2. A single observer measured IVIM parameters for each platform and estimated signal to noise ratio (eSNR) at b0, 200, 400 and 800 s/mm2. Wilcoxon paired tests were used to compare liver eSNR and IVIM parameters. Inter-platform reproducibility was assessed by calculating within-subject coefficient of variation (CV) and Bland–Altman limits of agreement. An ice water phantom was used to test ADC variability between the two MRI systems. Results: The mean invitro difference in ADC between the two platforms was 6.8%. eSNR was significantly higher at 3.0T for all selected b values (p = 0.006–0.020), except for b0 (p = 0.239). Liver IVIM parameters were significantly different between 1.5 T and 3.0 T (p = 0.005–0.044), except for ADC (p = 0.748). The inter-platform reproducibility of true diffusion coefficient (D) and ADC were good, with mean CV of 10.9% and 11.1%, respectively. Perfusion fraction (PF) and pseudodiffusion coefficient (D*) showed more limited inter-platform reproducibility (mean CV of 22.6% for PF and 46.9% for D*). Conclusion: Liver D and ADC values showed good reproducibility between 1.5 T and 3.0 T platforms; while there was more variability in PF, and large variability in D* parameters between the two platforms. These findings may have implications for drug trials assessing the role of IVIM DWI in tumor response and liver fibrosis