Selectivity of sodium pyrophosphate and unbuffered chlorides (CuCl2 and LaCl3) as extractants of aluminum bound to soil organic matter in soils of the sandy coastal plain in São Paulo state

O Al em complexos com matéria orgânica do solo é comumente determinado por técnicas de dissolução seletiva. Um extrator comum para essa forma do elemento é o pirofosfato de sódio. Devido à sua falta de seletividade para algumas amostras de solos, extratores não tamponados de Al, como CuCl2 e LaCl3, têm sido recomendados. A seletividade do pirofosfato de sódio (Al p) e dos cloretos não tamponados de cobre (AlCu) e de lantânio (AlLa) como extratores de Al ligado à matéria orgânica foi avaliada em 31 perfis de solos (Espodossolos e Neossolos Quartzarênicos), representativos das áreas sob vegetação de restinga do litoral paulista. Os resultados foram comparados aos obtidos com oxalato de amônio e KCl, seguindo-se as interpretações comumente observadas na literatura quanto à capacidade extratora e seletividade dos reagentes utilizados. Pirofosfato careceu de total seletividade para amostras que apresentaram formas inorgânicas de Al. Os reagentes CuCl2 e LaCl3, por sua vez, foram mais seletivos para as formas de Al orgânico nas mesmas amostras, cuja ordem de extractabilidade foi: Al p>AlCu>AlLa . As diferentes habilidades extratoras e as relações entre os reagentes utilizados possibilitaram convergir evidências analíticas a fim de analisar e interpretar algumas determinações, como saturação por Al no húmus e estabilidade das interações Corg-metal. Horizontes espódicos Bs, Bhs e Bsm detiveram a maior estabilidade da interação Corg-metal e saturação por Al no húmus entre todos os horizontes estudados. Dos resultados encontrados, conclui-se que todos os reagentes analisados podem ser utilizados como extratores de Al associado à matéria orgânica dos solos, uma vez que permitiram estabelecer relações e interpretações contundentes quanto ao entendimento da química dos complexos Al-húmus dos solos de restinga estudados. Esses extratores, portanto, são adequados e têm potencial para os estudos e entendimento dos processos envolvidos na gênese dos Espodossolos tropicais derivados de sedimentos quartzosos costeiros.Aluminum in complexes with soil organic matter is usually determined by selective extraction techniques. A common extractant for this Al form is sodium pyrophosphate. Due to its lack of selectivity for some soil samples, unbuffered Al extractants, such as CuCl2 and LaCl3, have been recommended. The selectivity of sodium pyrophosphate (Al p) and of unbuffered Cu (AlCu) and La (AlLa) chlorides to extract aluminum bound to soil organic matter (Al-humus) was evaluated in soil samples from 31 pedons (Spodosols and Quartzipsamments) representative of the sandy coastal plains of the state of São Paulo. The results were compared with those obtained by ammonium oxalate and KCl and the extraction capacity and selectivity of the reagents interpreted as commonly used in the literature. Pyrophosphate was not totally selective for some samples containing inorganic aluminum. CuCl2 and LaCl3, in turn, were more selective for Al-humus in the same samples and their order of extractability was: Al p>AlCu>AlLa . Based on the different extraction capacities and the relations between the reagents used the analytic evidences were converged in order to analyze and interpret parameters such as Al saturation in the soil organic matter and stability of C-metal interactions. The stability of the interaction C-metal and humus Al saturation of all horizons studied was greater in the Bs, Bhs and Bsm spodic horizons. Based on the results it was concluded that all reagents studied can be used as Al extractants since they allow establishing relations and interpretations that may help understanding the complex chemistry of Al-humus on the studied Restinga soil. These extractors are therefore adequate and promising to study and understand processes involved in the genesis of tropical Spodosols derived from sandy coastal plain sediments.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPES

Evidencias do cambio climático na hidrografía e a dinámica das rías e da plataforma galega

16 páginas, 9 figuras, 3 tablas[EN] This study is focused on multidecadal-scale variations of the hydrographic and hydrodynamic features of Rías and shelf waters off Galicia. Water masses take, through their thermohaline characteristics, a footprint of the climatic variability, mainly caused by changes either in the hydrological budget (precipitation, evaporation, runoff), in heat exchange and wind stress. In this study we focus in the evidences of change in the surface and sub-surface water mass characteristics. Regarding surface water masses, a significant warming during the last 45 years has been noticed, at a rate of 0.17 ºC/ decade. This warming was especially intense from the 1970’s, 0.27 ºC/decade. The tendency is opposite in subsurface waters, but it only takes into account data from the last 15 years. Regarding hydrodynamics, because of its strong influence in the renewal time of the Rías and consequently in their living resources, a study of decadal changes in the estuarine circulation of the Rías de Vigo and Arousa has been made. Results showed a progressive decay in the estuarine circulation, which causes an increase of renewal times. On the other hand, indirect evidence of a possible deceleration of the winter Iberian Poleward Current (IPC) are reported. This slow down is partially caused by a decrease in the meridional (N-S) temperature gradient off the Iberian coast. Nevertheless, the fall of the meridional gradient is not clear because it has been inferred from surface waters. On the contrary, IPC seems to be intensified by the increasing southerly autumn winds, although it appears weakened by the decreasing southerly winter winds. Thus, the overall effect of the CIP is still uncertain. Finally, a study of sea level and wave changes on the Galician coast has been made. An increase of (2-2.5 cm/ decade) in the sea level as well as a decrease in the wave height (3 cm/decade) has been reported, but in this last topic results are not significant[GA] Este estudo centrarase en determinar as variacións que ocorren a escalas multidecadais nas características hidrográficas e hidrodinámicas das augas das rías e da plataforma fronte a Galicia. As masas de auga reciben a través das súas características termohalinas unha pegada das alteracións climáticas, principalmente a causa de cambios no balance hidrolóxico (precipitación, evaporación, achegas continentais), do intercambio de calor e da acción do vento. Neste estudo analizaremos as evidencias de cambio nas características das masas de auga superficiais e subsuperficiais. Nas primeiras detectouse quentamento de xeito significativo nos últimos 45 anos a unha taxa media de 0,17 ºC por década, especialmente intenso desde hai 30 anos, 0,27 ºC por década. Nas augas subsuperficiais a tendencia é a inversa, aínda que só se conta con datos dos últimos 15 anos. En canto á hidrodinámica, e pola súa forte implicación nos tempos de renovación da ría e, polo tanto, nos recursos mariños que viven nela, fíxose un estudo sobre os cambios na circulación estuárica das rías de Vigo e Arousa nas últimas décadas. Os resultados amosan un descenso paulatino a longa escala temporal da circulación que causa un aumento dos tempos de renovación. Por outra banda, achéganse evidencias indirectas dunha posible ralentización da corrente invernal cara ao Polo (CIP) causada por un descenso no gradiente meridional (N-S) de temperatura fronte ás costas ibéricas. Non obstante, o descenso do gradiente meridional non está claro, pois induciuse só a partir de datos superficiais. Ademais, a propia CIP amosa estar intensificada pola maior intensidade dos ventos sur no outono e debilitada polo descenso dos ventos do sur no inverno, polo que o efecto global na CIP é aínda incerto. Por último, faise un estudo dos cambios do nivel do mar e da ondada nas costas galegas que amosa un aumento daquel (2-2,5 cm/década) e un descenso desta (3 cm/década), aínda que no caso da ondada os resultados non son concluíntesPeer reviewe

Analysis of total arsenic content in purchased rice from Ecuador

Natural and anthropogenic sources contribute to arsenic contamination in water and human food chain in Andean countries. Human exposure to arsenic via rice consumption is of great concern in countries where this crop is the dominant staple food, and limited information is available on the arsenic contamination on rice in Ecuador. This work was to contribute to the lack of knowledge analysing total arsenic by hydride generation-atomic absorption spectrometry in the samples of white, brown and parboiled rice purchased in Ecuadorian markets and produced in the two main rice wetlands in Ecuador, Guayas and Los Ríos, were carried out. For the samples from Guayas, arsenic concentration in white, brown and parboiled rice were 0.174 ± 0.014, 0.232 ± 0.021, and 0.186 ± 0.017 mg/kg respectively, whereas samples of white rice from Los Ríos showed a total arsenic level of 0.258 ± 0.037 mg/kg. This last arsenic concentration exceeds recommended maximum permissible limit by the FAO/WHO. Obtained data have available to estimate the Ecuadorian dietary exposure revealing serious health risk for population.S

Evaluation of Soil Organic Carbon Storage of Atillo in the Ecuadorian Andean Wetlands

Identifying the SOC levels and revealing the potential of SOC storage of ecosystems difficult to sample and study are necessary contributions to the understanding of the global reserves of SOC. Wetlands store large amounts of SOC within their soils. They have an important role in water regulation and have great biological and floristic diversity. Therefore, this study aimed to assess the SOC stock in Atillo micro-watershed in the Ecuadorian Andean wetlands at two soil depths (0¿30 cm and 30¿60 cm below ground) and to assess the importance of the ecosystem and its conservation in favor of reducing emissions due to degradation processes. For that, we sampled the study zone with 101 composite samples of soil to obtain the SOC storage for each sample point in Mg/ha. A SOC estimation to evaluate its spatial distribution was performed using the geostatistical method Kriging. The results show a high storage capacity of the study zone with SOC values of 126 to 454 Mg/ha in the 0¿30 cm soil profile and 148 to 350 Mg/ha in the 30¿60 cm soil profile. The preservation and protection mechanisms of high SOC reserves should be taken into account to prevent the emission of CO2

Signaling through the leukocyte integrin LFA-1 in T cells induces a transient activation of Rac-1 that is regulated by Vav and PI3K/Akt-1

12 p.-8 fig.Integrin LFA-1 is a receptor that is able to transmit multiple intracellular signals in leukocytes. Herein we show that LFA-1 induces a potent and transient increase in the activity of the small GTPase Rac-1 in T cells. Maximal Rac-1 activity peaked 10-15 min after LFA-1 stimulation and rapidly declined to basal levels at longer times. We have identified Vav, a guanine nucleotide exchange factor for Rac-1, and PI3K/Akt, as regulators of the activation and inactivation phases of the activity of Rac-1, respectively, in the context of LFA-1 signaling based on the following experimental evidence: (i) LFA-1 induced activation of Vav and PI3K/Akt with kinetics consistent with a regulatory role for these molecules on Rac-1, (ii) overexpression of a constitutively active Vav mutant induces activation of Rac independently of LFA-1 stimulation whereas overexpression of a dominant-negative Vav mutant blocks LFA-1-mediated Rac activation, (iii) pharmacological inhibition of PI3K/Akt prevented the fall in the activity of Rac-1 after its initial activation but had no effect on Vav activity, and (iv) overexpression of a dominant-negative or a constitutively active Akt-1 induced or inhibited, respectively, Rac-1 activity. Finally, we show that T cells with a sustained Rac activity have impaired capacity to elongate onto ICAM-1. These results demonstrate that down-regulation of the activity of this GTPase is a requirement for the regulation of T cell morphology and motility and highlight the importance of temporal regulation of the signaling triggered from this integrin.This work was supported in part by Grants CICYT SAF 2001–2807 from Ministerio de Ciencia y Tecnología and FIS-01/1367 from Ministerio de Sanidad y Consumo (to C. C.), a fellowship from Comunidad de Madrid (to L. S.-M.), a Formación de Profesorado Universitario predoctoral fellowship from Ministerio de Educación, Cultura y Deporte (to N. S.-S.), and a postdoctoral fellowship from Ministerio de Educación, Cultura y Deporte (to M. D. G.-L.).Peer reviewe

Aportaciones a la flora de Galicia, X

In this study mentioned 79 different plants with interest to the flora of Galicia and other territories of the Iberian Peninsula. One of them are new records for Spain flora (Watsonia bulbillifera), 24 are regional novelties (Crassula arborescens, Teline monspessulana, Hippocrepis comosa, Chamaesyce polygonifolia, Myosotis congesta, Verbena bonariensis, Senecio pyrenaicus, Taraxacum acutangulum, T. braun-blanquetii, T. cantabricum, T. ekmanii, T. fulgidum, T. hispanicum, T. lambinonii, T. maculosum, T. pinto-silvae, T. rubicundum, T. sundbergii, Agropyrum cristatum subsp. pectinatum, Bromus inermis, Pennisetum clandestinum, Eragrostis mexicana var. virescens, Iris planifolia, Chasmanthe floribunda), 26 novedades provinciales (Ranunculus peltatus subsp. peltatus var. peltatus, Modiola caroliniana, Sedum dendroideum, Paraserianthes lophantha, Geranium purpureum, Calystegia silvatica subsp. disjuncta, Echium vulgare subsp. pustulatum, Linaria aguillonensis, Linaria lamarckii, Glechoma hederacea, Asperula aristata subsp. scabra, Taraxacum drucei, T. gallaecicum, T. marklundii, T. nordstedtii, Luzula lactea, Commelina communis, Canna indica, Cyperus involucratus, Paspalum notatum, Asphodelus fistulosus, Muscari neglectum, Veratrum album, Iris foetidissima and Hedychium gardnerianum, Passiflora caerulea). Also 15 of them are commented by its taxonomic, ecologic or chorological interest. Clypeola jonthlaspi, Alchemilla transiens, Asperula cynanchica subsp. cynanchica, Valeriana tripteris subsp. tripteris, Luzula sudetica and Rhynchos pora modesti-lucennoi are confirmed for the Galician flora. Morever, in the light of further information, we remove 6 plants from the catalog of the vascular flora of Galicia (Iberis amara, I. linifolia, Sedum sediforme, Anarrhinum laxiflorum, Asperula aristata subsp. aristata and Taraxacum palustre) and Carex vesicaria from the catalog of the Parque Nacional de las Illas Atlánticas.En este trabajo se mencionan 79 plantas de diverso interés para la flora de Galicia y otras zonas de la Península ibérica. Se incluyen 1 novedades para España (Watsonia bulbillifera), 24 novedades regionales (Crassula arborescens, Teline monspessulana, Hippocrepis comosa, Chamaesyce polygonifolia, Myosotis congesta, Verbena bonariensis, Senecio pyrenaicus, Taraxacum acutangulum, T. braun-blanquetii, T. cantabricum, T. ekmanii, T. fulgidum, T. hispanicum, T. lambinonii, T. maculosum, T. pinto-silvae, T. rubicundum, T. sundbergii, Agropyrum cristatum subsp. pectinatum, Bromus inermis, Pennisetum clandestinum, Eragrostis mexicana var. virescens, Iris planifolia, Chasmanthe floribunda), 26 novedades provinciales (Ranunculus peltatus subsp. peltatus var. peltatus, Modiola caroliniana, Sedum dendroideum, Paraserianthes lophantha, Geranium purpureum, Calystegia silvatica subsp. disjuncta, Echium vulgare subsp. pustulatum, Linaria aguillonensis, Linaria lamarckii, Glechoma hederacea, Asperula aristata subsp. scabra, Taraxacum drucei, T. gallaecicum, T. marklundii, T. nordstedtii, Luzula lactea, Commelina communis, Canna indica, Cyperus involucratus, Paspalum notatum, Asphodelus fistulosus, Muscari neglectum,Veratrum album, Iris foetidissima y Hedychium gardnerianum, Passiflora caerulea) y otras 15 de interés diverso, bien ecológico, corológico o taxonómico. Se confirma la presencia de Clypeola jonthlaspi, Alchemilla transiens, Asperula cynanchica subsp. cynanchica, Valeriana tripteris subsp. tripteris, Luzula sudetica y Rhynchospora modesti-lucennoi. También, y a la luz de la información obtenida, eliminamos del catálogo de la flora vascular de Galicia 6 taxones (Iberis amara, I. linifolia, Sedum sediforme, Anarrhinum laxiflorum, Asperula aristata subsp. aristata y Taraxacum palustre) y Carex vesicaria del Parque Nacional de las Illas Atlánticas

Antimicrobial use and aetiology of bloodstream infections in critically ill patients during early stages of SARS-CoV-2 pandemic

Background: During early stages of COVID-19 pandemic, antimicrobials were commonly prescribed.Aim: To describe clinical, microbiological and antimicrobial use changes in bloodstream infections (BSI) of ICU patients during the first wave of COVID-19 pandemic compared to pre-COVID-19 era. Methods: Observational cohort study of patients admitted to ICU of Bellvitge University Hospital was conducted during the COVID-19 pandemic (March-June 2020) and before COVID-19 pandemic (March-June 2019). Differences in clinical characteristics, anti-microbial consumption and incidence and aetiology of BSI were measured.Findings: COVID-19 patients had significantly less comorbidities with obesity the only risk factor that increased in frequency. COVID-19 patients more frequently required invasive supportive care measures, had longer median ICU stay and higher mortality rates. The incidence of BSIs was higher in COVID-19 period (RR 3.2 [95%CI 2.2-4.7]), occurred in patients who showed prolonged median ICU stay (21days) and was associated with high mortality rate (47%). The highest increases in the aetiological agents were observed for AmpC-producing bacteria (RR 11.1 [95%CI 2.6-47.9]) and non-fermenting rods (RR 7.0 [95% CI 1.5-31.4]). The emergence of bacteraemia caused by Gram-negative rods resistant to amoxicillin-clavulanate, which was used as empirical therapy during early stages of the pandemic, led to an escalation towards broader-spectrum antimicrobials such as mer-openem and colistin which was also associated with the emergence of resistant isolates.Conclusions: The epidemiological shift towards resistant phenotypes in critically ill COVID-19 patients was associated with the selective use of antimicrobials. Our study provides evidence of the impact of empirical therapy on the selection of bacteria and their consequences on BSI over the subsequent months.& COPY; 2022 The Authors. Published by Elsevier Ltd on behalf of The Healthcare Infection Society.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)