Effects of Sand Addition to Heavy Saline-Alkali Soil on the Infiltration and Salt Leaching in Hetao Irrigation District, China

Proceeding PaperSoil salinity is a matter of great economic and environmental implications. In Hetao Irrigation District, soil salinity limits crop productivity affecting about 69% of its total cultivated land due to natural soil salinisation and salt accumulation caused by irrigation. The goal of this study is to contribute to the alleviation of this problem through the technique of adding wind-sand to the top layer of heavy saline-alkali soil, and to evaluate and analyse their effects on the infiltration and salt leaching. The experiment was carried out on a laboratory scale. Clayey soil with 21 g/kg of salts collected at the Ulat Front Banner site was used. Wind-sand was added to the top 30 cm layer of this soil. The infiltration tests were carried out in plastic columns with 9 cm diameter and 45 cm high, loaded with a soil and wind-sand mixture (from 2% to 30% ratio), supplied by a constant hydraulic head. Soil water samples were collected for 15 days for quantification of the soil salt leaching. A significant increase of the infiltration rate was observed in the first infiltration hour, rising from 1 to 9 mm/h, in response to the addition of 8% and 30% of sandy particles, respectively. The effects of wind-sand in salt leaching were relevant in the top 20 cm layer. After 7 days of infiltration there was a decrease in the salt content in soils with 4%, 8%, and 30% of sand particles added, of 35%, 55%, and 95%, respectively, in relation to the control. In conclusion, the practice of adding sandy particles to the topsoil is a soil melioration method that allows a positive impact on soil infiltration and salt leaching. An addition of 8% of sand seems to be a good choice, as it favours an increase in salt leaching of about 55% after 7 days. These results are encouraging and appeal to field studies to assess the impact on a field-scale system, and the effects of this soil melioration on irrigation, drainage, and agronomic aspectsinfo:eu-repo/semantics/publishedVersio

Sistemas agroflorestais agroecológicos em Rondônia: espécies, idade dos plantios e origem dos agricultores.

Sistemas agroflorestais são uma opção de uso do solo muito propícia para pequenos agricultores na região Amazônica brasileira. Esta pesquisa objetivou determinar idade dos sistemas agroflorestais, quais as espécies perenes que ocorrem e seu uso por produtores agroecológicos em diferentes municípios do Estado de Rondônia, bem como origem dos produtores. Foram visitados 23 sistemas em 20 propriedades. Foram encontrados sistemas com a média de 17 anos de plantio, onde café é a cultura principal. As espécies florestais de maior ocorrência foram paricá (Schizolobium parahyba var. amazonicum (Huber ex Ducke), seguida de ipê (Tabebuia sp), cerejeira (Torresia acreana Ducke ) e teca (Tectona grandis L. f.).Resumos do VIII Congresso Brasileiro de Agroecologia. Porto Alegre/RS ? 25 a 28/11/2013. Trabalho número 14753

Coating of Magnetite Nanoparticles with Fucoidan to Enhance Magnetic Hyperthermia Efficiency

Magnetic nanoparticles (NP), such as magnetite, have been the subject of research for application in the biomedical field, especially in Magnetic Hyperthermia Therapy (MHT), a promising technique for cancer therapy. NP are often coated with different compounds such as natural or synthetic polymers to protect them from oxidation and enhance their colloidal electrostatic stability while maintaining their thermal efficiency. In this work, the synthesis and characterization of magnetite nanoparticles coated with fucoidan, a biopolymer with recognized biocompatibility and antitumoral activity, is reported. The potential application of NP in MHT was evaluated through the assessment of Specific Loss Power (SLP) under an electromagnetic field amplitude of 14.7 kA m−1 and at 276 kHz. For fucoidan-coated NP, it was obtained SLP values of 100 and 156 W/g, corresponding to an Intrinsic Loss Power (ILP) of 1.7 and 2.6 nHm2kg−1, respectively. These values are, in general, higher than the ones reported in the literature for non-coated magnetite NP or coated with other polymers. Furthermore, in vitro assays showed that fucoidan and fucoidan-coated NP are biocompatible. The particle size (between ca. 6 to 12 nm), heating efficiency, and biocompatibility of fucoidan-coated magnetite NP meet the required criteria for MHT application

Coherent phonon and unconventional carriers in the magnetic kagome metal Fe3_3Sn2_2

Temperature- and fluence-dependent carrier dynamics of the magnetic Kagome metal Fe$_3$Sn$_2$ were studied using the ultrafast optical pump-probe technique. Two carrier relaxation processes ($\tau_1$ and $\tau_2$) and a laser induced coherent optical phonon were observed. By using the two-temperature model for metals, we ascribe the shorter relaxation $\tau_1$ (~1 ps) to hot electrons transferring their energy to the crystal lattice via electron-phonon scattering. $\tau_2$ (~25 ps), on the other hand, cannot be explained as a conventional process and is attributed to the unconventional (localized) carriers in the material. The observed coherent oscillation is assigned to be a totally symmetric A$_{1g}$ optical phonon dominated by Sn displacements out of the Kagome planes, and possesses a prominently large amplitude, on the order of 10$^{-3}$, comparable to the maximum of the reflectivity change ($\Delta$R/R). This amplitude is equivalent to charge-density-wave (CDW) systems, although no signs of such an instability were hitherto reported in Fe$_3$Sn$_2$. Our results set an unexpected connection between Fe$_3$Sn$_2$ and kagome metals with CDW instabilities, and suggest a unique interplay between phonon and electron dynamics in this compound.Comment: 12 pages, 14 figure

Otimização da diagnose molecular de vírus, bactéria e fungo em cana-de-açúcar.

RESUMO: Visando à otimização da diagnose molecular de plântulas de cana-de-açúcar, tentou-se desenvolver iniciadores específicos para escaldadura e ferrugem alaranjada, assim como a comparação da PCR comum e a PCR em Tempo Real (PCR/TR) de maior resolução, importante para doenças com grande período de latência, como as causadas por: 1- Bactérias, (a) raquitismo-da-soqueira (Leifsonina xyli subsp. Xyli) e (b) escaldadura (Xanthomonas aibilineans); 2- Vírus, (a) amarelinho (Sugarcane Yellow Leaf Vírus); (b) mosaico (Sugarcane Mosaic Vírus) e (c) fijivirus (Fiji disease vírus); 3- fungo, (a) carvão (Sporisorium scitamineum) e (b) ferrugem alaranjada (Puccinia kuehnii). As plântulas foram obtidas do quarentenário do IAC. Os iniciadores da literatura para cana-de-açúcar detectaram especificamente o raquitismo, amarelinho, mosaico e fijivirus, enquanto os desenvolvidos para PCR/TR para as mesmas doenças, incluindo a escaldadura e ferrugem alaranjada, possibilitaram a detecção com maior diluição das amostras. Os iniciadores da ferrugem alaranjada, além de não detectarem a ferrugem marrom, também diferenciaram a ferrugem branca do milho. Os da escaldadura não foram específicos somente para o gênero Erwinia, enquanto que os da literatura não diferenciaram também outras espécies dos gêneros Kanthomonas, Pseudomonas, Enwinia, Stenotrophomona e Pantoea. A otimização das diluições para PCR/TR a partir de cDNA foi de apenas lOX. Porém, para extratos de DNA de planta, foi maior, de lOOX a lOOOX,indicando a maior sensibilidade do método. Dos 28 pares de iniciadores testados, os melhores para o agente causal de cada doença e curvas de diluições (com eficiência de PCR de 1,05 a 1,28) são apresentados

Análises moleculares de bactérias e fungo em cana-de-açúcar.

RESUMO: A cana-de-açúcar é uma das principais culturas do Brasil, que é o maior produtor mundial de açúcar e álcool. A cultura da cana-de-açucar é extremamente vulnerável a doenças devido ao sistema de propagação por toletes facilitar a disseminação dos patógenos, uma vez que os colmos mesmo infectados podem não apresentar sintomas. A propagação dessas doenças em monoculturas em grandes áreas facilita as epidemias, sendo importante para o plantio de mudas sadias, métodos para a detecção precoce de doenças. Dentre as doenças mais importantes em cana-de-açúcar, são conhecidas as causadas por bactérias como a Leifsonia xyli subsp.xyli, agente causal do Raquitismo-da-soqueira ou ?ratoon stunting disease? (RSD) e a Xanthomonas albilineans, responsável pela Escaldadura das folhas ou ?sugarcarne leaf scald? (Ashby); por fungo como o do carvão (Ustilago scitaminea) que é uma doença considerada em todos os programas de melhoramento genético, com longo período de latência. Foram utilizadas como amostras folhas de plântulas de cana-açúcar desenvolvidas de cultura de tecido com cerca de 2 meses de transplante. Foram utilizados iniciadores de literatura para raquitismo e escaldadura ou desenvolvido pelo laboratório para carvão. Os fragmentos amplificados de cada doença foram clonados e a identidade confirmada por BLAST. O DNA dos controles positivos das reações foi obtido de clones dos fragmentos amplificados de plantas infectadas. Os iniciadores desenvolvidos para carvão mostraram especificidade em amostras de folhas de plântulas de cana-de-açúcar. A detecção de infecção confirma a eficácia da metodologia em plântulas com 2 meses de transplante, assim como o uso de clones como controle positivo, a maior facilidade para diagnostico de infecção em plântulas de cana-de-açúcar

Low-Protein Diet during Lactation and Maternal Metabolism in Rats

Some metabolic alterations were evaluated in Wistar rats which received control or low-protein (17%; 6%) diets, from the pregnancy until the end of lactation: control non-lactating (CNL), lactating (CL), low-protein non-lactating (LPNL) and lactating (LPL) groups. Despite the increased food intake by LPL dams, both LP groups reduced protein intake and final body mass was lower in LPL. Higher serum glucose occurred in both LP groups. Lactation induced lower insulin and glucagon levels, but these were reduced by LP diet. Prolactin levels rose in lactating, but were impaired in LPL, followed by losses of mammary gland (MAG) mass and, a fall in serum leptin in lactating dams. Lipid content also reduced in MAG and gonadal white adipose tissue of lactating and, in LPL, contributed to a decreased daily milk production, and consequent impairment of body mass gain by LPL pups. Liver mass, lipid content and ATP-citrate enzyme activity were increased by lactation, but malic enzyme and lipid: glycogen ratio elevated only in LPL. Conclusion. LP diet reduced the development of MAG and prolactin secretion which compromised milk production and pups growth. Moreover, this diet enhanced the store of lipid to glycogen ratio and suggests a higher risk of fatty liver development

Plant species of Sub-Family Valerianaceae—A review on its effect on the Central Nervous System

Valerianaceae, the sub-family of Caprifoliaceae, contains more than 300 species of annual and perennial herbs, worldwide distributed. Several species are used for their biological properties while some are used as food. Species from the genus Valeriana have been used for their antispasmodic, relaxing, and sedative properties, which have been mainly attributed to the presence of valepotriates, borneol derivatives, and isovalerenic acid. Among this genus, the most common and employed species is Valerianaofficinalis. Although valerian has been traditionally used as a mild sedative, research results are still controversial regarding the role of the different active compounds, the herbal preparations, and the dosage used. The present review is designed to summarize and critically describe the current knowledge on the different plant species belonging to Valerianaceae, their phytochemicals, their uses in the treatment of different diseases with particular emphasis on the effects on the central nervous system. The available information on this sub-family was collected from scientific databases up until year 2020. The following electronic databases were used: PubMed, Scopus, Sci Finder, Web of Science, Science Direct, NCBI, and Google Scholar. The search terms used for this review included Valerianaceae, Valeriana, Centranthus, Fedia, Patrinia, Nardostachys, Plectritis, and Valerianella, phytochemical composition, in vivo studies, Central Nervous System, neuroprotective, antidepressant, antinociceptive, anxiolytic, anxiety, preclinical and clinical studies.UIDB/05183/2020, DL 57/2016/CP1361/CT0022, UIDB/00313/2020info:eu-repo/semantics/publishedVersio

Collective oscillations of excitable elements: order parameters, bistability and the role of stochasticity

We study the effects of a probabilistic refractory period in the collective behavior of coupled discrete-time excitable cells (SIRS-like cellular automata). Using mean-field analysis and simulations, we show that a synchronized phase with stable collective oscillations exists even with non-deterministic refractory periods. Moreover, further increasing the coupling strength leads to a reentrant transition, where the synchronized phase loses stability. In an intermediate regime, we also observe bistability (and consequently hysteresis) between a synchronized phase and an active but incoherent phase without oscillations. The onset of the oscillations appears in the mean-field equations as a Neimark-Sacker bifurcation, the nature of which (i.e. super- or subcritical) is determined by the first Lyapunov coefficient. This allows us to determine the borders of the oscillating and of the bistable regions. The mean-field prediction thus obtained agrees quantitatively with simulations of complete graphs and, for random graphs, qualitatively predicts the overall structure of the phase diagram. The latter can be obtained from simulations by defining an order parameter q suited for detecting collective oscillations of excitable elements. We briefly review other commonly used order parameters and show (via data collapse) that q satisfies the expected finite size scaling relations.Comment: 19 pages, 7 figure