3,755 research outputs found
The uptake of macronutrients by an active silicon accumulator plant growing in two different substrata
Pennisetum clandestinum (Graminae/Poaceae) an active Si-accumulator, was cultivated in two different substrata, both with reduced Si solubility. Plants growing in organic-rich soils contained much less Ca, K, Na and Si, than species growing in sandy soils. Although the highest macronutrient concentrations were associated to the highest Si levels in the organs of P. clandestinum, the R correlation values indicate that Si does not influence the internal balance and the uptake of these elements. In ca 65% of the cases roots have the highest average values regardless of the type of culture, while the contents of Mg in the shoots and roots of P. clandestinum were generally not significantly different (P>0.05). A significant decline of the macronutrient levels associated to the shoots and roots of P. clandestinum was observed from the 4th to the 6th month assay, especially for Ca in both organs, while for Mg and Na the decline is focused mainly in the shoots; K and Si decline is generally below 10%. When average values of Si in shoots and roots of plants collected from organic- rich and sandy soils were plotted against the average concentrations of Ca, K, Mg and Na in the same organs, weak but positive R correlation values were obtained - the highest R values were observed for Na and K and the lowest for Ca and Mg, regardless of the culture. Exception for the high R value observed for K, although the influence of Si on the K status in the whole plant is time-depending - R values, diminished from the 4th to the 6th month, as it happens in the majority of the cases. In conclusion, P. clandestinum can grow well and healthily in substrata with acid pH values and high carbonate content and low solubility of Si suggesting that the definition of the essentiality of Si, even in a Si-accumulator plant is still a matter of great controversy.publishersversionpublishe
Characteristics of two conditioning regimens cyclophosphamide plus antithymocyte globulin versus cyclophosphamide plus busulfan in allogeneic stem cell transplantation for severe aplastic anemia
Universidade Federal de São Paulo, São Paulo, BrazilHosp Santa Marcelina, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
The taxonomic status of the endangered thin-spined porcupine, Chaetomys subspinosus (Olfers, 1818), based on molecular and karyologic data
<p>Abstract</p> <p>Background</p> <p>The thin-spined porcupine, also known as the bristle-spined rat, <it>Chaetomys subspinosus </it>(Olfers, 1818), the only member of its genus, figures among Brazilian endangered species. In addition to being threatened, it is poorly known, and even its taxonomic status at the family level has long been controversial. The genus <it>Chaetomys </it>was originally regarded as a porcupine in the family Erethizontidae, but some authors classified it as a spiny-rat in the family Echimyidae. Although the dispute seems to be settled in favor of the erethizontid advocates, further discussion of its affinities should be based on a phylogenetic framework. In the present study, we used nucleotide-sequence data from the complete mitochondrial cytochrome <it>b </it>gene and karyotypic information to address this issue. Our molecular analyses included one individual of <it>Chaetomys subspinosus </it>from the state of Bahia in northeastern Brazil, and other hystricognaths.</p> <p>Results</p> <p>All topologies recovered in our molecular phylogenetic analyses strongly supported <it>Chaetomys subspinosus </it>as a sister clade of the erethizontids. Cytogenetically, <it>Chaetomys subspinosus </it>showed 2n = 52 and FN = 76. Although the sexual pair could not be identified, we assumed that the X chromosome is biarmed. The karyotype included 13 large to medium metacentric and submetacentric chromosome pairs, one small subtelocentric pair, and 12 small acrocentric pairs. The subtelocentric pair 14 had a terminal secondary constriction in the short arm, corresponding to the nucleolar organizer region (Ag-NOR), similar to the erethizontid <it>Sphiggurus villosus</it>, 2n = 42 and FN = 76, and different from the echimyids, in which the secondary constriction is interstitial.</p> <p>Conclusion</p> <p>Both molecular phylogenies and karyotypical evidence indicated that <it>Chaetomys </it>is closely related to the Erethizontidae rather than to the Echimyidae, although in a basal position relative to the rest of the Erethizontidae. The high levels of molecular and morphological divergence suggest that <it>Chaetomys </it>belongs to an early radiation of the Erethizontidae that may have occurred in the Early Miocene, and should be assigned to its own subfamily, the Chaetomyinae.</p
Aluminium tolerance in bean traditional cultivars from Madeira
Common bean (Phaseolus vulgaris L.) is the most important legume crop in the world, providing low-cost, high quality protein, minerals and dietary fiber for human nutrition. The crop was originated from diversity centers in America and exhibits adaptation abilities to different environmental conditions, including soil with low pH. Acid soils occupy 30% of the agro ecosystem areas in the world. In Madeira, acid Andosols and unsatured Cambisols are the dominant groups of soils. Generally, under acidic and infertile conditions, besides of H+ toxicity, soluble aluminium (Al) is the most important abiotic factor limiting plant development and crop productivity. In the field, the hidden roots are also affected and the reduction of root growth under Al stress can be clearly observed in early stages. Seedlings of fifty bean accessions from the Archipelago of Madeira were tested under controlled conditions in the presence of 50 mM Al at pH 4.4. In general, the tested germplasm appeared to be sensitive or very sensitive to Al toxicity. However, fifteen traditional cultivars clearly exhibited elevated Al-tolerance, with an average root relative elongation (RRE) exceeding 50%, while top six accessions surpassed the 60% RRE mark. The Madeira bean germplasm is a valuable resource for sustainable crop production in acid soils and it could be used as parental lines in breeding programs aimed for Al tolerance in common beans
Quality of life in Dutch patients with primary biliary cholangitis:Discrepancies between patients’ perspectives and objective disease parameters
Aim: This study aims to assess the health-related quality of life (HRQoL) in a Dutch population of patients with primary biliary cholangitis (PBC) in relation to the prognosis and need for second line-therapy, based on both objective disease parameters and patients’ perspectives. Methods: In this cross-sectional multicenter study, HRQoL was assessed by using the Dutch PBC-40 according to objective clinical parameters and patients’ perspectives on treatment and prognosis. Results: In total, 178/269 (66%) patients responded; mean age 61.2 (SD 9.9) years and 165 (92.7%) women. The PBC-40 domain scores did not differ according to the GLOBE score response (p > 0.05 for all) or according to the POISE criteria (p > 0.05), except for the domain itch (p = 0.031). Patients who considered their survival to be impaired scored higher on all domains as compared to those expecting a normal prognosis (p < 0.05). Similarly, PBC-40 domain scores were higher among patients who considered that they were in need of additional therapy compared to those who did not (p < 0.05 for all, except for domain itch [p = 0.056]). However, 45/62 (72.6%) patients with a self-expected impaired prognosis had a GLOBE score indicative of a normal prognosis. Twenty-five of the 40 (62.5%) patients who believed they needed additional therapy were below POISE criteria. Conclusion: The HRQoL of patients with PBC was impaired in terms of nonfavorable disease status according to the expectations of patients, but not according to objective disease parameters. Substantial discrepancies between patients’ perspectives and objective parameters were observed, which highlights the need for better patient guidance among patient with PBC.</p
In situ H2O2 treatment of blue-green algae contaminated reservoirs causes significant improvement in drinking water treatability.
The evaluation of water quality improvement brought about by in situ treatment of eutrophic water bodies, especially those used for human supply, is a challenging task since each water system responds differently. To overcome this challenge, we applied exploratory factor analysis (EFA) to understand the effects of using hydrogen peroxide (H2O2) on eutrophic water used as a drinking water supply. This analysis was used to identify the main factors that described the water treatability after exposing blue-green algae (cyanobacteria) contaminated raw water to H2O2 at both 5 and 10 mg L-1. Cyanobacterial chlorophyll-a was undetectable following the application of both concentrations of H2O2 after four days, while not causing relevant changes to green algae and diatoms chlorophyll-a concentrations. EFA demonstrated that the main factors affected by both H2O2 concentrations were turbidity, pH and cyanobacterial chlorophyll-a concentration, which are important variables for a drinking water treatment plant. The H2O2 caused significant improvement in water treatability by decreasing those three variables. Finally, the use of EFA was demonstrated to be a promising tool in identifying which limnological variables are most relevant concerning the efficacy of water treatment, which in turn can make water quality monitoring more efficient and less costly
Estudos preliminares sobre a fertilidade dos solos de sequeiros em algumas zonas de Santiago.
A b s t r a c t : D r y l a n d f a r m i n g o n t h e s t e e p s l o p e s o f S a n t i a g o i s c a r a c t e r i z e d a s l o w i n p u t f a r m i n g . E v e r y y e a r t h e
f a r m e r s p r e p a r e a n d c u l t i v a t e t h e i r l a n d s , b u t t h e r e h a s n o t b e e n a n y s t u d y t o i d e n t i f y a n d q u a n t i f y t h e l i m i t i n g
f a c t o r e s c a u s i n g t h e d e c l i n e i n p r o d u c t i o n e v e n i n y e a r s o f g o o d r a i n f a l l . I n 1 9 8 7 , a y e a r o f g o o d r a i n f a l l , o n e
c o u l d i d e n t i f y s m a l l áreas a r o u n d t h e f a r m e r ' s h o u s e s , w h e r e t h e c o r n a n d b e a n s d i d n o t s h o w a n y s i g n o f m i n e -
r a l d i f i c i e n c y O n t h e o t h e r h a n d , t h e d i f i c i e n c y s y m p t o m s b e c a m e m o r e s e v e r e w i t h t h e d i s t a n c e f r o m t h e h o u -
s e s . T h e o b j e c t i v e s o f t h i s s t u d y w e r e t o d e t e r m i n e n u t r i e n t l e v e i s i n t h e s o i l s a n d p l a n t s , a n d t o i d e n t i f y p o s s i b l e
l i m i t i n g f a c t o r s i n t h e d r y l a n d a g r i c u l t u r a T h u s , f i v e r e p r e s e n t a t i v e áreas w e r e c h o s e n i n Ribeira de Faveta a n d
Assomada w i t h d i f f e r e n c e s i n c o r n p l a n t v i g o r a n d s t a n d . S o i l a n d p l a n t s a m p l e s w e r e t a k e n a n d a n a l y s e d f o r
m a c r o e l e m e n t s a n d m i c r o e l e m e n t s i n t h e l a b o r a t o r y . A l s o , p l a n t h e i g h t , p l a n t d e n s i t y , s l o p e , a s p e c t , a n d t h e d i s -
t a n c e a w a y f r o m t h e h o u s e s w e r e m e a s u r e d . R e s u l t s o f s o i l a n d p l a n t a n a l y s i s i d e n t i f i e d P o t a s s i u m a n d P h o s p h o -
r o u s t o b e r e l a t e d w i t h p l a n t h e i g h t
Salicornia as a fermented product: development of an optimised procedure for a controlled process
In order to develop a fermented product with young stems of salicornia/pickleweed, an experiment was worked out and the fermentative process was studied. Initial data on the bacterial fauna of the plants revealed the existence of no lactic acid bacteria. Therefore, we chose to use of starting cultures. Sterile “heart cabbage”
juice was the base for different fermentative bacteria: Lactobacillus plantarum, Leuconostoc mesenteroides,
Pediococcus acidilactici, and pH, titrated acidity and salinity were evaluated. The same experiment was undertaken with and without the glasswort or salicornia. Significant differences were observed only with L. plantarum: pH variation and percentage of lactic acid suffered a significant increase during the fermentative
process, specially when salicornia was introduced in the juice. Results obtained for the titrated acidity were also
good, since approximately 1% lactic acid was detected, as a result of the fermentative activity in the different starting cultures. Predominant species by the end of the fermentation was L. plantarum, being the one that produced higher quantities of lactic acid
Quantitative structure-activity relationships (QSAR) of 4-amino-2,6-diarylpyrimidine-5-carbonitriles with anti-inflammatory activity
The experimental anti-inflammatory activities of eight 4-amino-2,6-diarylpyrimidine-5-carbonitriles were subjected to a QSAR analysis based on results from B3LYP/6-31G(d,p) and AM1 electronic structure calculations. Principal component analyses and regressions based on these data indicate that potentially more active compounds should have low dipole moment and partition coefficient values and also be affected by the values of the charges of the carbon atoms through which the two aromatic rings are bonded to the pyrimidinic ring. Two new molecules were predicted to be at least as active as those with the highest activities used in the model building stage. One of them, having a methoxy group attached to one of the aromatic rings, was predicted to have an anti-inflammatory activity value of 52.3%. This molecule was synthesized and its experimental activity was found to be 52.8%, in agreement with the AM1 theoretical prediction. This value is 5% higher than the largest value used for modeling
Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)
Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade
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