Biochemical, Physiological and Anatomical Mechanisms of Adaptation of Callistemon citrinus and Viburnum lucidum to NaCl and CaCl2 Salinization

Callistemon citrinus and Viburnum lucidum are very appreciated and widespread ornamental shrubs for their abundant flowering and/or brilliant foliage. The intrinsic tolerance to drought/salinity supports their use in urban areas and in xeriscaping. Despite adaptive responses of these ornamental species to sodium chloride (NaCl) have been extensively explored, little is known on the effects of other salt solution, yet iso-osmotic, on their growth, mineral composition and metabolism. The present research aimed to assess responses at the biochemical, physiological and anatomical levels to iso-osmotic salt solutions of NaCl and CaCl2 to discriminate the effects of osmotic stress and ion toxicity. The two ornamental species developed different salt-tolerance mechanisms depending on the salinity sources. The growth parameters and biomass production decreased under salinization in both ornamental species, independently of the type of salt, with a detrimental effect of CaCl2 on C. citrinus. The adaptive mechanisms adopted by the two ornamental species to counteract the NaCl salinity were similar, and the decline in growth was mostly related to stomatal limitations of net CO2 assimilation rate, together with the reduction in leaf chlorophyll content (SPAD index). The stronger reduction of C. citrinus growth compared to V. lucidum, was due to an exacerbated reduction in net photosynthetic rate, driven by both stomatal and non stomatal limitations. In similar conditions, V. lucidum exhibited other additional adaptive response, such as modification in leaf functional anatomical traits, mostly related to the reduction in the stomata size allowing plants a better control of stomata opening than in C. citrinus. However, C. citrinus plants displayed an increased ability to retain higher Cl- levels in leaves than in roots under CaCl2 salinity compared to V. lucidum, thus, indicating a further attempt to counteract chloride toxicity through an increased vacuolar compartmentalization and to take advantages of them as chip osmotica

Leaf Anatomy and Photochemical Behaviour of Solanum lycopersicum

Plants can be exposed to ionising radiation not only in Space but also on Earth, due to specific technological applications or after nuclear disasters. The response of plants to ionising radiation depends on radiation quality/quantity and/or plant characteristics. In this paper, we analyse some growth traits, leaf anatomy, and ecophysiological features of plants of Solanum lycopersicum L. “Microtom” grown from seeds irradiated with increasing doses of X-rays (0.3, 10, 20, 50, and 100 Gy). Both juvenile and compound leaves from plants developed from irradiated and control seeds were analysed through light and epifluorescence microscopy. Digital image analysis allowed quantifying anatomical parameters to detect the occurrence of signs of structural damage. Fluorescence parameters and total photosynthetic pigment content were analysed to evaluate the functioning of the photosynthetic machinery. Radiation did not affect percentage and rate of seed germination. Plants from irradiated seeds accomplished the crop cycle and showed a more compact habitus. Dose-depended tendencies of variations occurred in phenolic content, while other leaf anatomical parameters did not show distinct trends after irradiation. The sporadic perturbations of leaf structure, observed during the vegetative phase, after high levels of radiation were not so severe as to induce any significant alterations in photosynthetic efficiency

Ostrácodos de Antofagasta de la Sierra, Puna catamarqueña, Argentina: su aporte a las interpretaciones paleolimnológicas del Holoceno

La Puna catamarqueña es un ámbito importante para los estudios paleoclimáticos. La concentración de agua y alimento en los humedales de esta zona hiperárida hace que los mismos tengan un rol esencial como centro de recursos para animales y las sociedades humanas. Por ello, el reconocimiento de los cambios paleoambientales tiene gran importancia en la comprensión de los patrones de ocupación humana durante el Holoceno relacionado con la disponibilidad de recursos. Se describen aquí asociaciones de ostrácodos actuales de humedales de Antofagasta de la Sierra, Puna catamarqueña, a fin de aportar datos para la interpretación de registros paleolimnológicos holocenos. Se analizaron las asociaciones de seis ambientes acuáticos diferentes por encima del piso de los 3400 msnm, lénticos y lóticos, considerando su heterogeneidad espacial. Este tipo de estudios son importantes para el avance de las investigaciones paleolimnológicas y paleoclimáticas de esta zona en donde la cantidad de datos disponibles es escasa. Entre las especies reconocidas, la especie de mayor distribución es Hemicypris panningi (Brehm). Habita vegas con abundante vegetación, tanto en facies de aguas estancadas como corrientes. Otra especie con una amplia distribución es Penthesilenula kohanga (Rossetti, Eagar y Martens). El análisis de las asociaciones recuperadas permite afirmar que la diversidad y composición específica de vegas de fondo de cuenca, lagunas y vegas de quebradas de altura (por encima de los 4000 msnm) presentan diferencias notables. Las vegas de fondo son los sitios más biodiversos, y están dominados por Hemicypris panningi y Penthesilenula kohanga. Por su parte, en las vegas de quebradas de altura, la biodiversidad es menor y se hallan presentes exclusivamente Heterocypris incongruens (Ramdohr) y Hemicypris panningi, mientras que en los ambientes lagunares se hallan presentes Paracandona sp. y Eucypris sp. aff. cecryphalium Cusminsky y Whatley.Simposio VIII: Paleoentomología y paleolimnología: objetivos particulares y comunesFacultad de Ciencias Naturales y Muse

RenalGuard system in high-risk patients for contrast-induced acute kidney injury.

BACKGROUND: High urine flow rate (UFR) has been suggested as a target for effective prevention of contrast-induced acute kidney injury (CI-AKI). The RenalGuard therapy (saline infusion plus furosemide controlled by the RenalGuard system) facilitates the achievement of this target. METHODS: Four hundred consecutive patients with an estimated glomerular filtration rate ≤30 mL/min per 1.73 m(2) and/or a high predicted risk (according to the Mehran score ≥11 and/or the Gurm score >7%) treated by the RenalGuard therapy were analyzed. The primary end points were (1) the relationship between CI-AKI and UFR during preprocedural, intraprocedural, and postprocedural phases of the RenalGuard therapy and (2) the rate of acute pulmonary edema and impairment in electrolytes balance. RESULTS: Urine flow rate was significantly lower in the patients with CI-AKI in the preprocedural phase (208 ± 117 vs 283 ± 160 mL/h, P 0.32 mg/kg (HR 5.03, 95% CI 2.33-10.87, P < .001) were independent predictors of CI-AKI. Pulmonary edema occurred in 4 patients (1%). Potassium replacement was required in 16 patients (4%). No patients developed severe hypomagnesemia, hyponatremia, or hypernatremia. CONCLUSIONS: RenalGuard therapy is safe and effective in reaching high UFR. Mean intraprocedural UFR ≥450 mL/h should be the target for optimal CI-AKI prevention