The state operator in process algebra

+138hlm.;21c

Efecto de la interacción riego-fertilización, en surco doble, sobre la producción de la papa (Solanum tuberosum sp andigena).

Se evaluó el efecto de distintos niveles de riego y fertilizantes sobre la producción de papa bajo el sistema de siembra en surco doble. El trabajo se realizó en el Centro Experimental Tibaitatá (Cundinamarca), en un lote de la serie Mosquera, de topografía plana y sin problemas de erosión. Se estudiaron 3 niveles de riego, 10 tratamientos de fertilización y la variedad de papa ICA-San Jorge. Se midieron los siguientes parámetros: curvas de avance; curvas de infiltración instantánea, acumulada y básica. Con base en estos parámetros se determinó el tiempo de avance, el tiempo de riego, pérdidas por percolación y escorrentía y eficiencia del riego. Hubo respuesta altamente significativa a la fertilización, pero no para el riego ni para la interacción riego por fertilización, situación que se debió a que las condiciones de alta precipitación, registrada durante el ensayo, determinaron contenidos altos de humedad en el suelo y el riego sólo se aplicó al final del período vegetativo. Se encontró respuesta altamente significativa al P, pero no al N ni a la interacción de este elemento con el P. La mejor relación N:P:K fué 1:3:1Papa-Solanum tuberosumMaestría en CienciasMaestrí

Contribución al estudio del viroide causante del ahusamiento de los tubérculos de papa: el potato spindle tuber viroid-PSTV.

Papa-Solanum tuberosumMaestría en CienciasMaestrí

Efecto de la fertilización fosfórica sobre la producción del arroz (Oriza sativa L.) de riego bajo tres sistemas de siembra.

Se analiza la importancia del fósforo y su absorción por las plantas de arroz, la disponibilidad del fósforo en suelos inundados, los síntomas de deficiencia en el cultivo, la fertilización fosfórica bajo riego con énfasis en el uso de rocas fosfóricas. Se describen y analizan investigaciones con roca fosfórica como fuente de fósforo bajo el sistema de siembra convencional, el fangueo y transplante con las variedades CICA-4, CICA-8, ORYZICA-1, ORYZICA-2 y ORYZICA-3, en el Valle del Zulia. Los resultados mostraron efectos significativos del fósforo sobre la producción de arroz en los 3 sistemas de manejo. Pero solamente hubo diferencias significativas entre los 2 tipos de rocas en el sistema de siembra convencional, aunque no las hubo entre estas y los superfosfatos. En fangueo y transplante no hubo diferencias entre las fuentes estudiadasArroz-Oryza sativ

Small-scale solar magnetic fields

As we resolve ever smaller structures in the solar atmosphere, it has become clear that magnetism is an important component of those small structures. Small-scale magnetism holds the key to many poorly understood facets of solar magnetism on all scales, such as the existence of a local dynamo, chromospheric heating, and flux emergence, to name a few. Here, we review our knowledge of small-scale photospheric fields, with particular emphasis on quiet-sun field, and discuss the implications of several results obtained recently using new instruments, as well as future prospects in this field of research.Comment: 43 pages, 18 figure

Particle physics models of inflation

Inflation models are compared with observation on the assumption that the curvature perturbation is generated from the vacuum fluctuation of the inflaton field. The focus is on single-field models with canonical kinetic terms, classified as small- medium- and large-field according to the variation of the inflaton field while cosmological scales leave the horizon. Small-field models are constructed according to the usual paradigm for beyond Standard Model physicsComment: Based on a talk given at the 22nd IAP Colloquium, ``Inflation +25'', Paris, June 2006 Curve omitted from final Figur

Estimation of Admission D-dimer Cut-off Value to Predict Venous Thrombotic Events in Hospitalized COVID-19 Patients: Analysis of the SEMI-COVID-19 Registry

Background: Venous thrombotic events (VTE) are frequent in COVID-19, and elevated plasma D-dimer (pDd) and dyspnea are common in both entities. Objective: To determine the admission pDd cut-off value associated with in-hospital VTE in patients with COVID-19. Methods: Multicenter, retrospective study analyzing the at-admission pDd cut-off value to predict VTE and anticoagulation intensity along hospitalization due to COVID-19. Results: Among 9386 patients, 2.2% had VTE: 1.6% pulmonary embolism (PE), 0.4% deep vein thrombosis (DVT), and 0.2% both. Those with VTE had a higher prevalence of tachypnea (42.9% vs. 31.1%; p = 0.0005), basal O2 saturation <93% (45.4% vs. 33.1%; p = 0.0003), higher at admission pDd (median [IQR]: 1.4 [0.6–5.5] vs. 0.6 [0.4–1.2] µg/ml; p < 0.0001) and platelet count (median [IQR]: 208 [158–289] vs. 189 [148–245] platelets × 109/L; p = 0.0013). A pDd cut-off of 1.1 µg/ml showed specificity 72%, sensitivity 49%, positive predictive value (PPV) 4%, and negative predictive value (NPV) 99% for in-hospital VTE. A cut-off value of 4.7 µg/ml showed specificity of 95%, sensitivity of 27%, PPV of 9%, and NPV of 98%. Overall mortality was proportional to pDd value, with the lowest incidence for each pDd category depending on anticoagulation intensity: 26.3% for those with pDd >1.0 µg/ml treated with prophylactic dose (p < 0.0001), 28.8% for pDd for patients with pDd >2.0 µg/ml treated with intermediate dose (p = 0.0001), and 31.3% for those with pDd >3.0 µg/ml and full anticoagulation (p = 0.0183). Conclusions: In hospitalized patients with COVID-19, a pDd value greater than 3.0 µg/ml can be considered to screen VTE and to consider full-dose anticoagulation. © 2021, Society of General Internal Medicine

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Paleobiology of titanosaurs: reproduction, development, histology, pneumaticity, locomotion and neuroanatomy from the South American fossil record

Fil: García, Rodolfo A.. Instituto de Investigación en Paleobiología y Geología. Museo Provincial Carlos Ameghino. Cipolletti; ArgentinaFil: Salgado, Leonardo. Instituto de Investigación en Paleobiología y Geología. General Roca. Río Negro; ArgentinaFil: Fernández, Mariela. Inibioma-Centro Regional Universitario Bariloche. Bariloche. Río Negro; ArgentinaFil: Cerda, Ignacio A.. Instituto de Investigación en Paleobiología y Geología. Museo Provincial Carlos Ameghino. Cipolletti; ArgentinaFil: Carabajal, Ariana Paulina. Museo Carmen Funes. Plaza Huincul. Neuquén; ArgentinaFil: Otero, Alejandro. Museo de La Plata. Universidad Nacional de La Plata; ArgentinaFil: Coria, Rodolfo A.. Instituto de Paleobiología y Geología. Universidad Nacional de Río Negro. Neuquén; ArgentinaFil: Fiorelli, Lucas E.. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica. Anillaco. La Rioja; Argentin