934 research outputs found

    Nanofertilizer use for adaptation and mitigation of the agriculture/climate change dichotomy effects

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    Artigo de revisãoAgriculture is considered a significant climate change (CC) driver due to greenhouse gas (GHG) emissions and the loss of fertilizers that contribute to water eutrophication. On the other hand, climate change effects are already impacting agriculture, endangering food security. This paper explores the dichotomies of the effects of agriculture on CC as well as of CC on agriculture, focusing on the contribution that nanofertilizers can bring to this complex system in both directions. The strategies to reduce CC while adapting and mitigating its effects must be a global effort. It is not possible to focus only on the reduction in GHG emissions to stop the effects that are already being felt worldwide. Nanofertilizers, especially slow- and controlled-release nanofertilizers, can reduce the nutrient input and also boost productivity while mitigating some CC effects, such as soil nutrient imbalance and agricultural emissions. As so, this review highlights the benefits of nanofertilizers and their role as a part of the strategy to reduce the reach of CC and mitigate its ever-growing effects, and presents some guidelines for the increased use of these materials in order to enhance their efficacy in this strategy.Fundação para a Ciência e Tecnologiainfo:eu-repo/semantics/publishedVersio

    Esophageal mucosal resection versus esophagectomy: a comparative study of surgical results in patients with advanced megaesophagus

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    The surgical treatment of advanced megaesophagus has no consensus, being esophagectomy the more commonly used method. Since it has high morbimortality--inconvenient for benign disease -, in recent years an alternative has been introduced: the esophageal mucosal resection. To compare early and late results of the two techniques evaluating the operative time, length of ICU stay; postoperative hospitalization; total hospitalization; intra- and postoperative complication rates; mortality; and long-term results. Were evaluated retrospectively 40 charts, 23 esophagectomies and 17 mucosectomies. In assessing postoperative results, interviews were conducted by using a specific questionnaire. Comparing the means of esophagectomy and mucosal resection, respectively, the data were: 1) surgical time--310.2 min and 279.7 min (p > 0.05); 2) length of stay in ICU--5 days and 2.53 days (p 0.05); 4) length of hospital stay after surgery--19.05 days and 14.94 days (p> 0.05); 5) presence of intraoperative complications--65% and 18% (p 0.05). In the assessment of late postoperative score (range 0-10) esophagectomy (n = 5) obtained 8.8 points and 8.8 points also got mucosal resection (n = 5). Esophageal mucosal resection proved to be good alternative for surgical treatment of megaesophagus. It was advantageous in the immediate postoperative period by presenting a lower average time in operation, the total hospitalization, ICU staying and complications rate. In the late postoperative period, the result was excellent and good in both operations.The surgical treatment of advanced megaesophagus has no consensus, being esophagectomy the more commonly used method. Since it has high morbimortality--inconvenient for benign disease -, in recent years an alternative has been introduced: the esophageal m2812831sem informaçãosem informaçã

    Novel and conserved microRNAs in soybean floral whorls

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    AbstractMicroRNAs (miRNAs) correspond to a class of endogenous small non-coding RNAs (19–24nt) that regulates the gene expression, through mRNA target cleavage or translation inhibition. In plants, miRNAs have been shown to play pivotal roles in a wide variety of metabolic and biological processes like plant growth, development, and response to biotic and abiotic stress. Soybean is one of the most important crops worldwide, due to the production of oil and its high protein content. The reproductive phase is considered the most important for soybean yield, which is mainly intended to produce the grains. The identification of miRNAs is not yet saturated in soybean, and there are no studies linking them to the different floral organs. In this study, three different mature soybean floral whorls were used in the construction of sRNA libraries. The sequencing of petal, carpel and stamen libraries generated a total of 10,165,661 sequences. Subsequent analyses identified 200 miRNAs sequences, among which, 41 were novel miRNAs, 80 were conserved soybean miRNAs, 31 were new antisense conserved soybean miRNAs and 46 were soybean miRNAs isoforms. We also found a new miRNA conserved in other plant species, and finally one miRNA-sibling of a soybean conserved miRNA. Conserved and novel miRNAs were evaluated by RT-qPCR. We observed a differential expression across the three whorls for six miRNAs. Computational predicted targets for miRNAs analyzed by RT-qPCR were identified and present functions related to reproductive process in plants. In summary, the increased accumulation of specific and novel miRNAs in different whorls indicates that miRNAs are an important part of the regulatory network in soybean flower

    Chitosan as a biostimulant component in nanofertilizers

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    Comunicação em painelO desenvolvimento de alternativas aos fertilizantes convencionais tem vindo a ganhar destaque nos últimos anos. A necessidade de alimentar a crescente população mundial, as premissas de sustentabilidade a que o mundo se propõe e a necessidade efetiva de combater os efeitos das alterações climáticas, são precursores desta mudança, a par dos preços galopantes que se têm verificado nos inputs de produção. Assim, o desenvolvimento de nanofertilizantes surge como uma oportunidade para o setor agrícola, numa lógica de solução-à-medida e de precisão de aplicação. A inclusão de substâncias bioestimulantes nas formulações deve ser considerada, a fim de aumentar a resistência e a resiliência das culturas aos efeitos das alterações antropogénicas, que já se fazem sentir e que irão piorar nos próximos anos. O quitosano é um polissacarídeo, biocompatível e biodegradável que tem sido utilizado como veículo para outros compostos agrícolas devido às suas propriedades biodegradáveis e não tóxicas. A maior parte da quitina comercial, da qual o quitosano é derivado, é produzida a partir de resíduos de camarões, gambas e caranguejos. Este composto é apontado como tendo efeito bioestimulante para o sistema imunitário das culturas, promovendo efeitos antifúngicos, antivirais, bionematicidas e o reforço de enzimas catalisadoras. Vários estudos relataram melhorias no solo após a sua utilização, como a maior retenção de água e remoção de metais pesados, mas também efeitos benéficos na qualidade da água, pelo controlo de contaminação por algas. Uma vez que as preparações de quitosano são distintas de estudo para estudo, e a componente fitotoxicológica é muitas vezes inexistente, este estudo teve como objetivo alcançar uma formulação de quitosano a ser utilizado em pellets nanofertilizantes e aferir o seu efeito na germinação de Lepidium sativum L. Os ensaios de germinação utilizando Lepidium sativum L., são realizados de acordo com a norma europeia EN 16086-2, onde o índice de comprimento das raízes e o índice de vitalidade de Munoo Liisa são determinados, permitindo qualificar o nível de fitotoxicidade ou o efeito bioestimulante do composto. Neste estudo são realizados dois tratamentos e feita a comparação com o controlo. Em cada modalidade, foram colocadas dez sementes sobre um papel filtro, em placas de Petri de 9 cm de diâmetro e em quadruplicado. Adicionaram-se 3 mL de solução e incubaram-se as placas a 25 ± 2 °C, durante 72 h. As imagens foram tratadas com o software “Image J” e realizou-se a análise de variância a 1 fator, sendo a comparação múltipla de médias realizada através do teste de Tukey (p<0,05). Não é expectável encontrar efeito fitotóxico do composto, mas sim confirmar o efeito bioestimulante do quitosano, utilizado na presente forma, para incorporar o design final dos pellets nanofertilizantes em desenvolvimento.The development of alternatives to conventional fertilizers has been gaining momentum in recent years. The need to feed the growing world population, the premises of sustainability that the world proposes and the effective need to combat the effects of climate change, are precursors of this change, along with the galloping prices that have been registered in production inputs. Thus, the development of nanofertilizers appears as an opportunity for the agricultural sector, in a logic of tailor-made solution and precision of application. The inclusion of biostimulants must be considered in order to increase the resistance and resilience of crops to the effects of anthropogenic changes, which are already being felt and will become worse in the coming years. Chitosan is a biodegradable, biocompatible polysaccharide that has been used as a carrier for other agricultural compounds due to its biodegradable and non-toxic properties. Most commercial chitin, from which chitosan is derived, is produced from shrimp, prawn and crab waste. This compound is reported to have a biostimulant effect on crop immune systems, promoting antifungal, antiviral, bionematicidal effects and enhancing catalytic enzymes. Several studies have reported soil improvements after its use, such as increased water retention and removal of heavy metals, but also beneficial effects on water quality by controlling algal contamination. Since chitosan preparations are distinct from study to study, and the phytotoxicological component is often lacking, this study aimed to achieve a formulation of chitosan to be used in nano fertilizer pellets and to assess the effect on the germination of Lepidium sativum L. Germination tests using Lepidium sativum L., are carried out according to the European standard EN 16086-2, where the root length index and the Munoo-Liisa vitality index are determined, allowing to qualify the level of phytotoxicity or the biostimulant effect of the compound. Two treatments are tested and compared with the control. In each mode, ten seeds were placed on a filter paper, in Petri dishes of 9 cm diameter and in quadruplicate. Then, 3 mL of solution are added and the petri dishes go to incubation at 25 ± 2 °C during 72 h. The images are treated with the software "Image J" and the analysis of variance was performed at 1 factor, being the multiple comparison of means obtained through the Tukey test (p<0.05). It is not expected to find phytotoxic effect of the compound, but rather to confirm the biostimulant effect of chitosan, used in the present form, to incorporate in the final design of the nanofertilizer pellets under development.Fundação para a Ciência e a Tecnologiainfo:eu-repo/semantics/publishedVersio

    Potential alternative feed sources for ruminant feeding from the biodiesel production chain by-products

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    This study aimed to evaluate the chemical composition, fractionation of nitrogen compounds and carbohydrates, digestibility parameters, gas production kinetics and ruminal fermentation of fruit seed cakes. The experiment was conducted in a completely randomized design with three fruit seed cakes (treatments) and four replications. The cakes were made of seeds of custard apple (Annona squamosa), soursop (Annona muricata) and passion fruit (Passiflora edulis), which were collected in a biodiesel plant. The passion fruit seed cake presented the highest content of dry matter, neutral detergent fibre crude protein (NDFcp), acid detergent fibre (ADF), lignin and total carbohydrates (P&lt;0.05). The custard apple seed cake presented high proportions of crude protein, condensed tannins and digestible energy (P&lt;0.05). The soursop seed cake presented higher values for ether extract and total digestible nutrients (P&lt;0.05). For potential degradability, the authors detected a difference between the custard apple, soursop and passion fruit seed cakes. The total volume of gases was higher for custard apple and soursop seed cakes. Custard apple seed cake presented higher proportions of in vitro degradation parameters (P&lt;0.05). Thus this cake could provide greater nutrient levels when supplied in ruminant diets, followed by soursop seed cake and passion fruit seed cake. Keywords: alternative food, by-products, ruminant feeding, seed cake, semi-ari

    Roughness of Sandpile Surfaces

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    We study the surface roughness of prototype models displaying self-organized criticality (SOC) and their noncritical variants in one dimension. For SOC systems, we find that two seemingly equivalent definitions of surface roughness yields different asymptotic scaling exponents. Using approximate analytical arguments and extensive numerical studies we conclude that this ambiguity is due to the special scaling properties of the nonlinear steady state surface. We also find that there is no such ambiguity for non-SOC models, although there may be intermediate crossovers to different roughness values. Such crossovers need to be distinguished from the true asymptotic behaviour, as in the case of a noncritical disordered sandpile model studied in [10].Comment: 5 pages, 4 figures. Accepted for publication in Phys. Rev.

    Identification of Schistosoma mansoni microRNAs

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    Background: MicroRNAs (miRNAs) constitute a class of single-stranded RNAs which play a crucial role in regulating development and controlling gene expression by targeting mRNAs and triggering either translation repression or messenger RNA (mRNA) degradation. miRNAs are widespread in eukaryotes and to date over 14,000 miRNAs have been identified by computational and experimental approaches. Several miRNAs are highly conserved across species. In Schistosoma, the full set of miRNAs and their expression patterns during development remain poorly understood. Here we report on the development and implementation of a homology-based detection strategy to search for miRNA genes in Schistosoma mansoni. In addition, we report results on the experimental detection of miRNAs by means of cDNA cloning and sequencing of size-fractionated RNA samples. Results: Homology search using the high-throughput pipeline was performed with all known miRNAs in miRBase. A total of 6,211 mature miRNAs were used as reference sequences and 110 unique S. mansoni sequences were returned by BLASTn analysis. The existing mature miRNAs that produced these hits are reported, as well as the locations of the homologous sequences in the S. mansoni genome. All BLAST hits aligned with at least 95% of the miRNA sequence, resulting in alignment lengths of 19-24 nt. Following several filtering steps, 15 potential miRNA candidates were identified using this approach. By sequencing small RNA cDNA libraries from adult worm pairs, we identified 211 novel miRNA candidates in the S. mansoni genome. Northern blot analysis was used to detect the expression of the 30 most frequent sequenced miRNAs and to compare the expression level of these miRNAs between the lung stage schistosomula and adult worm stages. Expression of 11 novel miRNAs was confirmed by northern blot analysis and some presented a stage-regulated expression pattern. Three miRNAs previously identified from S. japonicum were also present in S. mansoni. Conclusion: Evidence for the presence of miRNAs in S. mansoni is presented. The number of miRNAs detected by homology-based computational methods in S. mansoni is limited due to the lack of close relatives in the miRNA repository. In spite of this, the computational approach described here can likely be applied to the identification of pre-miRNA hairpins in other organisms. Construction and analysis of a small RNA library led to the experimental identification of 14 novel miRNAs from S. mansoni through a combination of molecular cloning, DNA sequencing and expression studies. Our results significantly expand the set of known miRNAs in multicellular parasites and provide a basis for understanding the structural and functional evolution of miRNAs in these metazoan parasites

    Metabolic profile and histopathology of kidneys and liver of lambs fed silages of forages adapted to a semi-arid environment

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    Thirty-two mixed-breed ram lambs (average age, 5.6 ± 0.4 months, and average live weight, 17.61 ± 2.63 kg) were used to evaluate the effect of diets containing silages of forages adapted to a semi-arid environment on the metabolic profile in serum and the histopathological assessment of liver and kidney tissues of the lambs. Lambs were allocated, in a completely randomised design, to four treatments (silage of old man saltbush (Atriplex nummularia Lind), buffelgrass (Cenchrus ciliaris), gliricidia (Gliricidia sepium) and ‘pornunça’ (Manihot sp.). The feedlot period was 49 days, and animals were slaughtered at an average weight of 27 ± 4.6 kg. On the last day of the experiment, blood was collected from the jugular vein of all animals to measure the protein, metabolic and energy profiles of the lambs. At slaughter, kidney and liver samples were collected for histopathological examination. The consuming of the diet containing buffelgrass silage resulted in a significantly higher activity of alanine-aminotransferase (30.14 IU/L) and the concentrations of urea (44.25 mg/dL), creatinine (0.94 mg/dL) and albumin (4.48 g/dL) in serum. Diets containing gliricidia silage resulted in significantly higher gamma-glutamyl transferase activity (92.0 IU/L), while the diets with pornunça silage resulted in higher serum levels of triglycerides (37.85 mg/dL). The diets had no effect on aspartate-aminotransferase enzyme activity and total protein, cholesterol and globulin concentrations, or the albumin : globulin ratio in serum. Mild congestion, necrosis and foci of mineralisation were observed in the kidneys of animals fed diets containing old man saltbush (50%) and pornunça (25%) silages, and mild fatty degeneration and mild mononuclear inflammatory infiltrate in their livers. In conclusion, diets containing silages of forages that are adapted to semi-arid environments may be used for feeding lambs, given the absence of dysfunctioning plasmatic levels of liver enzymes and energy and protein profiles. Additionally, kidney failure was not observed in lambs fed these diets during the feedlot period.Keywords: blood parameters, buffelgrass, gliricidia, old man saltbush, pornunç

    Characteristics of carcass and non-carcass components of lambs fed diets containing silages of forages adapted to the semi-arid environment

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    The aim of this study was to evaluate the effects of diets containing silages of forages that are adapted to the semi-arid environment on the characteristics of the carcass and of non-carcass components of 32 mixed-breed lambs at approximately six months old, with an average live weight of 17.61 ± 2.63 kg. Lambs were assigned to four treatments (diets containing silages of Atriplex nummularia Lind, Cenchrus ciliaris, Gliricidia sepium and Manihot sp.) in a completely randomized design with eight replicates. Animals fed the diet containing old man saltbush showed higher values for the intakes of dry matter (1.080 g/day), crude protein (190 g/day) and total digestible nutrients (740 g/day), body condition score (2.81 points), fatness (2.87 points), carcass conformation (3.19 points), live weight (29.1 kg), empty bodyweight (23.41 kg), weights of the commercial cuts neck, shoulder and ribs (0.46, 0.82 and 1.12 kg, respectively), and skin weight (1.972 kg). No differences were found between the diets for carcass dressing percentage, external and internal carcass lengths, leg length and circumference, rump circumference and width, chest width and depth, full bodyweight, empty bodyweight, cooling losses, pH before and after cooling, loin, and leg. Silages of old man saltbush, buffelgrass, gliricidia and pornunça are recommended for inclusion in lamb diets. Diets with old man saltbush silage provide the best results for characteristics of the carcass and of non-carcass components besides weight gain, which can reach up to 200 g/day depending on the formulation.Keywords: Carcass composition, feedlot, saltbush, shee

    Carcass characteristics and meat quality of sheep fed buffelgrass silage to replace corn silage

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    The aim of the study was to evaluate the carcass characteristics, proximate composition, and sensorial attributes of meat from sheep fed diets in which buffelgrass silage replaced corn silage. Thirty-two intact male crossbred Santa Inês sheep with an average live weight of 20.09 ± 2.0 kg were housed in individual stalls and allotted at random to four treatments in which corn silage was replaced by buffelgrass silage at the levels of 0 (control), 33.3%, 66.6%, and 100%. After an adaption period of 10 days, the sheep were fed for an additional 61 days. Feed was offered ad libitum and corn silage comprised 60% of the diet for the control group. Carcass characteristics, non-carcass components and meat quality were evaluated. Hot carcass yield, cold carcass yield, true carcass yield, trimmings, fat weight, and mesenteric and omental fat weight were highest for the control group (P &lt;0.05). Loin eye area had a quadratic response (P =0.02), with the largest areas being observed in animals fed the diet containing 66.6% buffelgrass silage. Liver weight (P &lt;0.01), luminosity of the meat (P &lt;0.05), and cooking loss (P &lt;0.05) likewise had nonlinear responses to the concentration of buffelgrass silage in the diet. The treatments did not have significant negative influence on the nutritional and organoleptic characteristics of the meat
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