Abstract Objectives: To determine the cut-off point of the cochlear radiation dose as a risk factor for hearing loss in patients with vestibular schwannoma treated with radiosurgery. Methods: A systematic review of the literature was performed without language or publication year restrictions in the MEDLINE/PubMed, EMBASE, Web of Science, LILACS/VHL and Cochrane Library databases. Studies that met the following criteria were included: 1) population: adults of both sexes who underwent radiosurgery for vestibular schwannoma treatment; 2) exposure: cochlear radiation; 3) outcome: hearing loss; 4) type of study: cohort. Two independent reviewers conducted the entire review process. The registration number in PROSPERO was CRD42020206128. Results: From the 333 articles identified in the searches, seven were included after applying the eligibility criteria. There was no standardization as to how to measure exposure or outcome in the included studies, and most studies did not present sufficient data to enable meta-analysis. Conclusion: It was not possible to determine a cut-off point for high cochlear dose that could be considered a risk factor for hearing loss.

Mari-mari (Cassia leiandra Benth.) is an Amazonian native fruit that is highly appreciated in the northern region of Brazil, but there are few studies regarding its chemical composition and/or biological properties. A phytochemical study was conducted on the extracts of the pulp, peel and seeds; and their antioxidant, cytotoxic and antimicrobial potential were also determined. Methanol and acetone extracts from different fruit parts were subjected to total phenolic, 2,2-diphenyl-1 picrylhydrazyl (DPPH) radical scavenging and FeIII reducing capacity (FRAP) assays. From the peel extracts, the engeletin and astilbin could also be isolated and characterized based on nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. A quantification using ultra-fast liquid chromatography of acetone dry crude extracts (DCE) of the peel showed that engeletin was the main compound (532.77 mg g-1 DCE). Astilbin content was also determined (131.53 mg g-1 DCE). The antibacterial and antiproliferative activities were evaluated and the methanol extract of the peel showed higher growth inhibition activity against all tested bacteria. Engeletin showed a relevant antimicrobial effect against Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli. Acetone and methanol peel extracts exhibited a relevant inhibitory effect on the proliferation of breast carcinoma cells (MCF-7), with no toxicity to the normal cell line (NIH/3T3).

Abstract The indiscriminate use of allopathic drugs has selected resistant bacterial and fungal populations which represents a severe public health problem worldwide. On the other hand, plants are in a prominent position due to the capability to synthesize structurally complex bioactive metabolites that can be an alternative to resistant microorganisms’ control. In this work, we evaluated the chemical composition and the antimicrobial, antioxidant, and cytotoxic potential of the fractionated extract of C. savannarum in ethyl acetate. The extract of C. savannarum was divided into 12 fractions that were submitted to phytochemical screening, minimum inhibitory concentration (MIC), reduction of 1,1-diphenyl-2-picrylhydrazine (DPPH), and hemolytic activity of sheep erythrocytes assays. During the investigation, all extract fractions presented alkaloids, triterpenoids, steroids, and phenolic compounds in qualitative analyses, while in the quantitative evaluation, we observed the presence of both phenols and flavonoids in these fractions. Among the fraction, the highest phenolic content was observed in the Cs23-24 fraction (2.480 mg EAG/g), while the Cs31-34 fractions presented the highest amount of flavonoid (182.25 μg EQ/100 mg). Nine of the 12 fractions of the moss species’ extract showed antimicrobial action Against Gram-positive bacteria: Bacillus cereus, Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis; Gram-negative bacteria: Pseudomonas aeruginosa; and also antifungal activity against Candida albicans and Candida glabata. The cytotoxic assay demonstrated that the tested fractions did not induce hemolysis at concentrations 10 and 100(µG/ML). In the antioxidant evaluation, the Cs55-69 fractions were the ones that presented the highest scavenging activity (57, 0%) followed by the Cs45-54 fraction (42.7%). Overall, the evaluation of the biological potential of the fractionated extracts of Campylopus savannarum showed promising data, in the search for natural antimicrobial compounds.

Resumo O uso indiscriminado de drogas alopáticas tem selecionado populações bacterianas e fúngicas resistentes, o que representa um grave problema de saúde pública mundial. Por outro lado, as plantas ocupam posição de destaque devido à capacidade de sintetizar metabólitos bioativos estruturalmente complexos que podem ser uma alternativa ao controle de microrganismos resistentes. Neste trabalho, avaliamos a composição química e o potencial antimicrobiano, antioxidante e citotóxico do extrato fracionado de C. savannarum em acetato de etila. O extrato de C. savannarum foi dividido em 12 frações que foram submetidas aos ensaios de triagem fitoquímica, concentração inibitória mínima (CIM), redução de 1,1-difenil-2-picrilhidrazina (DPPH) e atividade hemolítica de eritrócitos de ovinos. Durante a investigação, todas as frações do extrato apresentaram alcalóides, triterpenóides, esteróides e compostos fenólicos nas análises qualitativas, enquanto na avaliação quantitativa, observou-se a presença de fenóis e flavonoides nessas frações. Dentre as frações, o maior teor de fenólicos foi observado na fração Cs23-24 (2,480 mg EAG/g), enquanto as frações Cs31-34 apresentaram a maior quantidade de flavonoides (182,25 μg EQ/100 mg). Nove das 12 frações do extrato da espécie de musgo apresentaram ação antimicrobiana contra bactérias Gram-positivas: Bacillus cereus, Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis; Bactérias Gram-negativas: Pseudomonas aeruginosa; e também atividade antifúngica contra Candida albicans e Candida glabata. O ensaio citotóxico demonstrou que as frações testadas não induziram hemólise nas concentrações 10 e 100(µG/ML). Na avaliação antioxidante, as frações Cs55-69 foram as que apresentaram maior atividade seqüestradora (57,0%) seguida da fração Cs45-54 (42,7%). No geral, a avaliação do potencial biológico dos extratos fracionados de Campylopus savannarum mostrou dados promissores, na busca de compostos antimicrobianos naturais.

Resumo Foram avaliadas a composição da dieta de duas espécies de Characideos (Knodus heteresthes e Moenkhausia lepidura) nos rios Teles Pires e Juruena, amostrados em setembro e outubro de 2016. Analisamos 226 estômagos de K. heteresthes e 425 de M. lepidura, sendo utilizados os métodos volumétrico e frequência de ocorrência, aplicando-se o índice de importância alimentar. Para a similaridade das dietas entre as espécies calculamos a sobreposição de nicho com índice de Pianka. Ambas as espécies no rio Juruena têm preferência alimentar por artrópodes (IAi > 0,95), no rio Teles Pires a dieta concentra-se em três fontes para ambas espécies: artrópodes (IAi > 0,52), vegetais (IAi > 0,33) e peixes (IAi > 0,12). A dieta é dissimilar quando comparados os ambientes (ANOSIM, R ≥ 0,57; p < 0,001), com alta sobreposição de nicho trófico (α > 0,97), independente do ambiente amostrado. No rio Teles Pires, ambas as espécies foram classificadas como onívoras com tendência insetívora e no rio Juruena ocorre o comportamento insetívoro.

Abstract The composition of the diet of two species of characids (Knodus heteresthes and Moenkhausia lepidura) was evaluated in the Teles Pires and Juruena Rivers, sampled in September and October 2016. We analyzed 226 stomachs of K. heteresthes and 425 of M. lepidura. The analysis of the stomach contents was based on volumetric and frequency of occurrence methods, applying the food importance index. For the similarity of the diets between the species we calculated the niche overlap with Pianka’s index. Both species in the Juruena River have a dietary preference for arthropods (IAi > 0.95). In the Teles Pires River the diet is concentrated in three sources for both species: arthropods (IAi > 0.52), vegetables (IAi > 0.33) and fish (IAi > 0.12). The diet was dissimilar when compared to environments (ANOSIM, R ≥ 0.57, p < 0.001) with high trophic niche overlap (α > 0.97), regardless of the sampled environment. In the Teles Pires River, both species were classified as omnivorous with an insectivorous tendency and in the Juruena River the insectivorous behaviour occurs.

Resumo Esse trabalho objetivou analisar a eficiência do reforço com adição de barras de aço e adesivo epóxi em vigas de concreto armado. Foram produzidas cinco vigas. Quatro receberam reforço à flexão e em duas delas também foram utilizados grampos em “U” para melhorar a ancoragem do reforço. Os ensaios mostraram que os grampos reduziram a resistência das vigas em relação às sem grampos. As vigas reforçadas sem grampos obtiveram melhores resultados, sendo o maior limitador a aderência entre o epóxi e a viga. O uso dos grampos para tentar resolver o problema da aderência deram originalidade a essa pesquisa. As conclusões foram baseadas nas comparações entre as vigas ensaiadas.

Abstract This work was aimed at analyzing the efficiency of the strengthening of reinforced concrete beams with the addition of steel bars and epoxy adhesive. Five beams were produced, out of which four beams were strengthened to flexure. In two of them, “U” clips were also used to improve the anchorage of the strengthening. The tests demonstrated that the clips reduced the resistances of the beams compared to those without clips. The strengthened beams without clips yielded better results, but the largest limiting factor was the adherence between the epoxy and beam. The use of clips for solving the problem of adherence made this research original. The conclusions were based on the comparisons of the tested beams.

Resumen Este trabajo tuvo como objetivo analizar la eficiencia del refuerzo en vigas de hormigón armado mediante la adición de barras de acero y adhesivo epoxi. Se produjeron cinco vigas. Cuatro recibieron refuerzo a flexión, y en dos de ellas fueron adicionadas también abrazaderas “U” para mejorar el anclaje del refuerzo. Los ensayos mostraron que las abrazaderas redujeron la resistencia de las vigas, en comparación con las que no tenían. Las vigas reforzadas sin abrazaderas obtuvieron mejores resultados, pero el factor limitante más importante fue la adherencia entre el epoxi y la viga. El uso de abrazaderas para intentar resolver el problema de la adherencia dio originalidad a esta investigación. Las conclusiones se basaron en la comparación entre las vigas ensayadas.

ABSTRACT Ischemia is responsible for many metabolic abnormalities in the heart, causing changes in organ function. One of modifications occurring in the ischemic cell is changing from aerobic to anaerobic metabolism. This change causes the predominance of the use of carbohydrates as an energy substrate instead of lipids. In this case, the glycogen is essential to the maintenance of heart energy intake, being an important reserve to resist the stress caused by hypoxia, using glycolysis and lactic acid fermentation. In order to study the glucose anaerobic pathways utilization and understand the metabolic adaptations, New Zealand white rabbits were subjected to ischemia caused by Inflow occlusion technique. The animals were monitored during surgery by pH and lactate levels. Transcription analysis of the pyruvate kinase, lactate dehydrogenase and phosphoenolpyruvate carboxykinase enzymes were performed by qRT-PCR, and glycogen quantification was determined enzymatically. Pyruvate kinase transcription increased during ischemia, followed by glycogen consumption content. The gluconeogenesis increased in control and ischemia moments, suggesting a relationship between gluconeogenesis and glycogen metabolism. This result shows the significant contribution of these substrates in the organ energy supply and demonstrates the capacity of the heart to adapt the metabolism after this injury, sustaining the homeostasis during short-term myocardial ischemia.

ABSTRACT In this study, we have optimized production of bacterial cellulose (BC) by Komagataeibacter hansenii ATCC 23769 in a static cultivation using sisal juice, an agroindustrial residue, as substrate. Optimization of fermentation parameters has been carried out using the one-variable-at-a-time method. Effect of initial sugar concentration, pH, nitrogen supplement, and cultivation time was evaluated. The influence of nitrogen source and quantity for bacterial cellulose production was studied using a central composite rotational design (CCRD).The highest production of BC (3.38 g/L) was obtained after 10 days of cultivation, using sisal juice (pH 5) at 15 g/L of sugars and supplemented with 7.5 g/L of extract yeast. The cellulose production yield in selected sisal culture conditions was three times higher than the yield in synthetic medium, indicating that sisal juice is a suitable substrate for BC production.

BACKGROUND: Cryotherapy is a widely used technique in physical therapy clinics and sports. However, the effects of cryotherapy on dynamic neuromuscular control are incompletely explained. OBJECTIVES: To evaluate the effects of cryotherapy applied to the calf, ankle and sole of the foot in healthy young adults on ground reaction forces during gait initiation. METHOD: This study evaluated the gait initiation forces, maximum propulsion, braking forces and impulses of 21 women volunteers through a force platform, which provided maximum and minimum ground reaction force values. To assess the effects of cooling, the task - gait initiation - was performed before ice application, immediately after and 30 minutes after removal of the ice pack. Ice was randomly applied on separate days to the calf, ankle and sole of the foot of the participants. RESULTS: It was demonstrated that ice application for 30 minutes to the sole of the foot and calf resulted in significant changes in the vertical force variables, which returned to their pre-application values 30 minutes after the removal of the ice pack. Ice application to the ankle only reduced propulsion impulse. CONCLUSIONS: These results suggest that although caution is necessary when performing activities that require good gait control, the application of ice to the ankle, sole of the foot or calf in 30-minute intervals may be safe even preceding such activities.

Background: Seaweeds are good sources of dietary fibre, which can influence glucose uptake and glycemic control. Objective: To investigate and compare the in vitro inhibitory activity of different extracts from Undaria pinnatifida (Wakame), Himanthalia elongata (Sea spaghetti) and Porphyra umbilicalis (Nori) on α-glucosidase activity and glucose diffusion. Methods: The in vitro effects chloroform-, ethanol- and water-soluble extracts of the three algae were assayed on α-glucosidase activity and glucose diffusion through membrane. Principal Components Analysis (PCA) was applied to identify patterns in the data and to discriminate which extract will show the most proper effect. Results: Only water extracts of Sea spaghetti possessed significant in vitro inhibitory effects on α-glucosidase activity (26.2% less mmol/L glucose production than control, p < 0.05) at 75 min. PCA distinguished Sea spaghetti effects, supporting that soluble fibre and polyphenols were involved. After 6 h, Ethanol-Sea spaghetti and water-Wakame extracts exerted the highest inhibitory effects on glucose diffusion (65.0% and 60.2% vs control, respectively). This extracts displayed the lowest slopes for glucose diffusion-time lineal adjustments (68.2% and 62.8% vs control, respectively). Conclusions: The seaweed hypoglycemic effects appear multi-faceted and not necessarily concatenated. According to present results, ethanol and water extracts of Sea spaghetti, and water extracts of Wakame could be useful for the development of functional foods with specific hypoglycemic properties.

Antecedentes: Las algas son importante fuente alimentaria de fibra dietética y puede influir sobre la absorción de glucosa y el control glucémico. Objetivo: Evaluar y comparar in vitro los efectos de diferentes extractos de las algas Undaria pinnatifida (Wakame), Himanthalia elongata (Espagueti de mar) y Porphyra umbilicalis (Nori) sobre la actividad enzimàtica α-glucosidasa y la difusión de glucosa. Métodos: Se estudiaron los efectos de los extractos clorofórmicos, etànólicos y acuosos de las tres algas sobre la actividad α-glucosidasa y la difusión de glucosa a través de una membrana de diàlisis. Se aplicó a los resultados un análisis de los componentes principales (PCA) para identificar posibles patrones de composición y seleccionar el extracto que mejores propiedades posea. Resultados: El extracto acuoso de Espagueti de mar inhibió de forma significativa la actividad α-glucosidasa (26,2% menos liberación de glucosa, p < 0,05). El PCA sugiere que la fibra soluble y los polifenoles son los responsables de tal efecto. Respecto a la difusión de glucosa, el extracto etanólico de Espagueti de mar y el acuoso de Wakame mostraron un mayor efecto inhibidor después de 6 horas (65% y 60,2% vs control, respectivamente) y las menores pendientes en los ajustes lineales difusión de glucosa-tiempo (68,2% y 62,8% vs control respectivamente). Conclusiones: Los resultados de los diferentes extractos sugieren que los efectos hipogluceminates de las algas son variados y no están necesariamente concatenados. Los extractos acuosos y etanólicos de Espagueti de mar y los acuosos de Wakame parecen los más adecuados para el desarrollo de alimentos funcionales con propiedades hipoglucemiantes.

Restructured pork (RP) enriched in Seaweeds are potential functional foods. The antiapoptotic and hypocholesterolemic effects of consuming cholesterol enriched diets containing Wakame-RP (CW), Nori-RP (CN) and Sea Spaghetti (CS) were tested in a 1-wk study. Groups of six rats per group were fed a mix of 85% AIN-93M rodent-diet containing cholesterol and cholic acid as a cholesterol rising agent plus 15% RP containing alga. These diets were compared to control-RP diets enriched or not in cholesterol (CC and C, respectively). After 1-wk, cholesterol feeding significantly increased liver apoptosis markers which were significantly reduced by CS (cellular cycle DNA, caspase-3, and cytochrome c), CN (caspase-3 and cytochrome c) and CW (caspase-3) diets. CN and CS diets significantly blocked the cholesterolaemic rising effect observed in the CC group but no protective effect was observed in the CW group. Differences in seaweed composition added to RP appear responsible for blocking or not the proapoptotic and hypercholesterolemic effects of high cholesterol-RP consumption; thus, any generalization on seaweed effects or food containing seaweeds must be avoided. Although present results are worthy, future studies are demanded to ascertain the utility of consuming algal-RP as part of usual diets.

La incorporación de algas, ricas en fibra y compuestos asociados, a reestructurados de carne de cerdo (R) resulta en derivados cárnicos potencialmente funcionales. En este trabajo se estudian los efectos antiapoptóticos e hipocolesterolemiantes de dietas en las que se incluyen agentes hipercolesterolemiantes y R enriquecidos en diferentes algas, Wakame (RW), Nori-R (RN) y Espagueti de Mar (RE). Durante una semana grupos de seis ratas cada uno recibieron una mezcla constituida por 85% de dieta AIN-93M para roedores suplementada con colesterol y ácido cólico, como agente hipercolesterolemiante, y 15% de RW, RN o RE. Estas dietas fueron comparadas con otras a las que se incorporó R control y a las que se añadió o no el agente hipercolesterolemiante. Después de 1 semana de tratamiento el incremento de marcadores de apoptosis hepática observado en el lote control con colesterol se redujo por el consumo de las dietas RE (DNA ciclo celular, caspasa-3, y citocromo c), RN (caspasa-3, y citocromo c) and RW (caspasa-3). Sólo las dietas con RN and RE bloquearon significativamente la inducción hipercolesterolemiante de la dieta control enriquecida en colesterol. Teniendo en cuenta las diferencias observadas entre los lotes respecto a sus efectos hipocolesterolémicos y antiapoptóticos, debe evitarse cualquier generalización sobre el consumo de algas y en particular de carnes conteniendo algas. Aunque los resultados son relevantes, deben realizarse estudios futuros para determinar la utilidad del consumo de estos R enriquecidos en algas dentro de dietas habituales.

Background: Pain is one of the most feared outcomes of surgery by patients, yet current practices of pain management are suboptimal. Failure to address acute postoperative pain can have a variety of consequences that affect physical and psychological aspects of the patient. Current perioperative pain management normally consists of opioid therapy, which has been a mainstay for many years. However, use of opioids can have moderate risks, including nausea/vomiting, dizziness, and constipation, or more severe risks, including respiratory depression and immunosupression. Aim: In order to address some of the issues surrounding perioperative pain management, a group of key opinion leaders gathered at an international summit to analyze the current practices of perioperative pain management. One of the topics focused on buprenorphine's role in perioperative pain and the information discussed is presented throughout this article. Conclusion: Buprenorphine has been demonstrated to be effective and safe in many postoperative pain models. Its administration versatility, its manageable side effects, and its use in combination with other analgesics allow buprenorphine therapy to be successful in perioperative pain management.

Antecedentes: El dolor es uno de los eventos más temidos por los pacientes después de una cirugía, y en la actualidad el manejo del dolor es subóptimo. La falta de control del dolor agudo postoperatorio puede tener una serie de consecuencias que afectan a los aspectos físicos y emocionales de los pacientes. El manejo habitual del dolor postoperatorio se basa en la utilización de opioides, pilar de tratamiento desde hace muchos años. Sin embargo, el uso de opioides puede tener riesgos moderados, como son las náuseas y vómitos, mareos y constipación, o riesgos más severos que incluyen a la inmunosupresión y depresión respiratoria. Objetivo: Para poder determinar algunos de los factores circundantes del dolor postoperatorio, se realizó una reunión cumbre internacional en la que un grupo de líderes de opinión analizó las prácticas habituales de manejo de dolor postoperatorio. Uno de los temas abordados fue el rol de la buprenorfina en el manejo del dolor perioperatorio, y la información discutida se presenta a lo largo de este artículo. Conclusión: La buprenorfina ha demostrado ser eficaz y segura en muchos modelos de dolor postoperatorio. Su versatilidad de administración, sus efectos secundarios manejables y su posibilidad de ser combinada con otros analgésicos hacen que la buprenorfina sea exitosa en el manejo del dolor perioperatorio.

O intuito deste estudo foi avaliar as espécies acarinas encontradas em amostras de poeira de cortinas presentes em 33 salas e 22 quartos de um total de 41 domicílios na cidade de Campinas, SP. Foram encontrados 148 ácaros. Desse total, 83 foram encontrados na sala de TV (56,1% do total) e 65 nos quartos (43,9%). As principais subordens encontradas foram: Acaridida (n = 79; 53.4%), Actinedida (n = 53; 35.8%), Oribatida (n = 14; 9.5%) e Gamasida (n = 2; 1.3%). As principais famílias observadas foram: Pyroglyphidae (n = 61; 41,2% do total), Eriophyidae (n = 25; 16,9%), Tarsonemidae (n = 15; 10,1%) e Glycyphagidae (n = 13; 8,8%). Não houve diferença significativa no número de ácaros observados nas amostras da sala e do quarto.

The aim of this study was to investigate the mite fauna present in 33 living room and 22 bedroom curtain dust samples from 41 different homes in the southern Brazilian city of Campinas, SP. A total of 148 mite bodies were found. Of these, 83 were found in living-room curtain samples (56.1% of total) and 65 were in bedroom curtain dust samples (43.9%). The most frequently observed mite suborders were: Acaridida (n = 79; 53.4%), Actinedida (n = 53; 35.8%), Oribatida (n = 14; 9.5%), and Gamasida (n = 2; 1.3%). The most frequent families were Pyroglyphidae (n = 61; 41.2%), Eriophyidae (n = 25; 16.9%), Tarsonemidae (n = 15; 10.1%), and Glycyphagidae (n = 13; 8.8%). No statistical difference was observed between the number of mites found in the samples from living room and bedroom curtains.

O experimento, realizado em casa de vegetação no Departamento de Ciência do Solo da Universidade Federal de Lavras, teve por objetivo estudar o efeito de diferentes relações de CaSO4/CaCO3, que simulam o uso de gesso e calcário, na movimentação de nutrientes no solo e no crescimento do algodoeiro, cultivar IAC-20. As proporções de CaSO4/CaCO3 utilizadas foram: 0/100, 25/75, 50/50, 75/25 e 100/0, com base em peso equivalente, além de um tratamento-testemunha, sem aplicação de CaSO4 e CaCO3. Observou-se acentuada movimentação de cálcio e de sulfato em profundidade, como íons acompanhantes, com o aumento da relação CaSO4/CaCO3. Para o N-NO3- e Mg2+, ao contrário do N-NH4+ e K+, observou-se um acúmulo em profundidade, com a elevação da relação CaSO4/CaCO3. Neste estudo, o gesso teve pouco ou nenhum efeito sobre a acidez e Al trocável presentes nas camadas subsuperficiais. A produção de matéria seca do algodoeiro foi reduzida com o aumento da relação CaSO4/CaCO3, porém, quando comparada à do tratamento-testemunha, a aplicação de gesso aumentou-a significativamente, atestando o potencial de uso do gesso agrícola.

The experiment was carried out in greenhouse at the Soil Science Departament - Federal University of Lavras, Minas Gerais, Brazil. The objective was to study the effects of different CaSO4/CaCO3 ratios on the movement of nutrients in soil and cotton growth. The treatments consisted of four CaSO4/CaCO3 percentage ratios (100/0, 75/25, 50/50, 25/75 and 0/100), in an equivalent basis. A control treatment, without application of either CaSO4 or CaCO3, was also established. Substantial calcium and sulfate movement downwards was observed with increasing CaSO4/CaCO3 ratios. On the contrary, N-NH4+ and K, N-NO3- and Mg movement increased with the CaSO4/CaCO3 ratios. Gypsum had little or no effect on subsoil acidity and exchange aluminum. Dry matter yield of cotton was reduced with increasing CaSO4/CaCO3 ratios, however, as compared to the control treatment. The application of gypsum was capable of markedly reducing the negative growth effect of acid soils.