2,285 research outputs found
Use of gibberellin in floriculture
This review aimed to show the use of gibberellin in floriculture. In this context, it should be noted that the benefit of the activity of the gibberellins has brought major advances in the field of physiology. Its use is one of the most important tools for the development of agriculture. Thus, the study concluded that the use of gibberellins has been increasingly used by producers and is also a vast important subject that may help in increasing the production of flowers if the farms are dedicated to this purpose.Keywords: Regulators plants, flowers, phenotypic characteristics, postharves
Stem diameter and height of chrysanthemum cv Yoko ono as affected by gibberellic acid
The effect of gibberellic acid has been shown mainly to promote cell division and elongation. This study was aimed to evaluate the development of height and diameter of the stems of chrysanthemum cultivar Yoko ono by the applications of gibberellic acid (GA3) in the field. The treatments were composed of four doses (0, 40, 80 and 120 mg L-1) at 15 and 30 days after transplanting. From the findings, It can be concluded that GA3 significantly affected the diameter of stem at higher doses, and was unable to affect the height of stem.Key words: Dendranthema grandiflora, flowers, plant regulator, concentration
Phytopythium kandeliae (Oomycetes, Straminipila)
Abstract Phytopythium kandeliae was recently published as a new combination. The existence of contradictory information about the vouchers CBS 111.91, 112.91 and 113.91 at the CBS-KNAW and the identity of the ex-type specimen is herein clarified
In vitro and in vivo assessment of the anti-malarial activity of Caesalpinia pluviosa
<p>Abstract</p> <p>Background</p> <p>To overcome the problem of increasing drug resistance, traditional medicines are an important source for potential new anti-malarials. <it>Caesalpinia pluviosa</it>, commonly named "sibipiruna", originates from Brazil and possess multiple therapeutic properties, including anti-malarial activity.</p> <p>Methods</p> <p>Crude extract (CE) was obtained from stem bark by purification using different solvents, resulting in seven fractions. An MTT assay was performed to evaluate cytotoxicity in MCF-7 cells. The CE and its fractions were tested <it>in vitro </it>against chloroquine-sensitive (3D7) and -resistant (S20) strains of <it>Plasmodium falciparum</it> and <it>in vivo </it>in <it>Plasmodium chabaudi</it>-infected mice. <it>In vitro </it>interaction with artesunate and the active <it>C. pluviosa </it>fractions was assessed, and mass spectrometry analyses were conducted.</p> <p>Results</p> <p>At non-toxic concentrations, the 100% ethanolic (F4) and 50% methanolic (F5) fractions possessed significant anti-malarial activity against both 3D7 and S20 strains. Drug interaction assays with artesunate showed a synergistic interaction with the F4. Four days of treatment with this fraction significantly inhibited parasitaemia in mice in a dose-dependent manner. Mass spectrometry analyses revealed the presence of an ion corresponding to <it>m/z </it>303.0450, suggesting the presence of quercetin. However, a second set of analyses, with a quercetin standard, showed distinct ions of <it>m/z </it>137 and 153.</p> <p>Conclusions</p> <p>The findings show that the F4 fraction of <it>C. pluviosa </it>exhibits anti-malarial activity <it>in vitro </it>at non-toxic concentrations, which was potentiated in the presence of artesunate. Moreover, this anti-malarial activity was also sustained <it>in vivo </it>after treatment of infected mice. Finally, mass spectrometry analyses suggest that a new compound, most likely an isomer of quercetin, is responsible for the anti-malarial activity of the F4.</p
Cerebral tuberculomas in aids patients - A forgotten diagnosis?
The human immunodeficiency virus (HIV) infection epidemics increased the prevalence, multi-drug resistance and disseminated forms of tuberculosis. The central nervous system (CNS) tuberculosis has high mortality and morbidity, and it is usually divided into diffuse (meningitis) and localized (tuberculoma and abscess) forms. We report three cases of cerebral tuberculomas in AIDS patients: one with definitive diagnosis, confirmed with histopathology, and two with probable diagnosis, based on clinical information, radiological images, Mycobaterium tuberculosis isolation out of the CNS and adequate response to antituberculous treatment. Further, we discuss diagnostic, therapeutic and prognostic issues of tuberculomas, with emphasis in the distinction from cerebral tuberculous abscesses. Despite of their infrequent presentation, tuberculomas should be considered in the differential diagnosis of cerebral expansive lesions in patients with AIDS.623B79379
Gauge symmetry and W-algebra in higher derivative systems
The problem of gauge symmetry in higher derivative Lagrangian systems is
discussed from a Hamiltonian point of view. The number of independent gauge
parameters is shown to be in general {\it{less}} than the number of independent
primary first class constraints, thereby distinguishing it from conventional
first order systems. Different models have been considered as illustrative
examples. In particular we show a direct connection between the gauge symmetry
and the W-algebra for the rigid relativistic particle.Comment: 1+22 pages, 1 figure, LaTeX, v2; title changed, considerably expanded
version with new results, to appear in JHE
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