197 research outputs found
In vitro effects of regulators on growth and morphogenesis of Ocimum basilicum L. ‘Alfavaca Green’ stem apexes
Large-scale cultivation of contamination free plants requires a good standardization
protocol and production methods. Basil is widely used for cosmetics, food and pharmaceutical
industries as it is rich in many bioactive compounds. This present study aimed to evaluate the
growth and in vitro anatomical aspects of apical buds of basil grown under
different concentrations rowth regulators like: NAA (Naphthalenoacetic Acid), BAP
(6-benzylaminopurine), and KIN (Kinetin). The in vitro establishment was evaluated every 20
days to calculate the, the percentage of plants with calluses, appearance of the roots, any abnormal
seedlings, any oxidized seedlings, and the number of sprouts per plant. Growth, physiological,
and morpho-anatomical evaluations were performed at 80 days. Basal callogenesis was observed
when cytokinin’s and auxins are used in combination. Auxin treatments caused hyperhydricity in
the stems and leaves. Medium A2 (0.05 mg L
-1 of NAA and 0.1 mg L
-1 of BAP), and A3
(0.05 mg L
-1 of NAA and 0.1 mg L
-1 of KIN) resulted in the best development of basil plants,
cultivar ‘Alfavaca Green’. The A2 produced plants with greater numbers of leaves, an average
bud length of 59.81 mm, and the best root properties. A2 and A1 have a higher percentage of
hyperhydricity (83 and 67%). The A3 resulted in an acceptable number of leaves (range: 21–39),
and this treatment produced the best shoot properties as well as fewer plants with hyperhydricity.
In addition, the A3 treatment produced plants with a shoot length, high shoot fresh and dry mass
(2.82 and 0.23 g), high chlorophyll index and leaf anatomy that was similar to the control.
Excluding the control, the other treatments presented more than 90% of the explants with calluses
in their bases
Copper modulates the biochemical and enzymatic activity and growth of tomato cultivars grown in vitro
Received: August 25th, 2020 ; Accepted: December 17th, 2020 ; Published: February 09th, 2021 ; Correspondence: [email protected] (Cu) is a micronutrient that is neglected for tomato growth. This study sought
to identify the effects of exposure to Cu on the growth and biochemical activity of two tomato
cultivars. Tomato seeds of ‘Carolina’ and ‘Cereja’ cultivars were disinfected and inoculated in
MS medium plus copper sulfate concentrations (CuSO4) (default MS, 25, 50, and 100 µm) and
had their growth monitored for 30 days. It was estimated that the growth and biomass
accumulation of tomato plants ‘Carolina’ and ‘Cereja’, both from the aerial part and the roots,
were benefited by 25 e 50 µm of CuSO4. However, it was observed that these concentrations were
inefficient in controlling hyperhydricity and leaf deformation. There was a reduction of these
phenomena in the treatment with 100 µm, in both cultivars. Tomato of ‘Carolina’ cultivar
subjected to 100 µm showed an increase in anthocyanins and superoxide dismutase (SOD)
activity in the root system. There was a reduction of catalase (CAT) activity in shoots exposed to
Cu. ‘Cereja’ tomatoes subjected to 100 µm showed an increase in CAT and SOD activity in
shoots and roots, respectively. It was concluded that the ‘Carolina’ and ‘Cereja’ tomatoes have
their growth impaired when exposed to 100 µm CuSO4. Concentrations higher than 50 µm of
CuSO4 cause an increase in the antioxidant activity in the shoot of tomato plants from the
‘Carolina’ cultivar. Concentrations higher than 50 µm CuSO4 increase SOD activity in the root
system of tomato plants from the ‘Cereja’ cultivar
Characterization of anti-crotalic antibodies
AbstractCrotalus durissus terrificus, C. d. collilineatus, C. d. cascavella and C. d. marajoensis are responsible minor but severe snake bites in Brazil. The venoms of these snakes share the presence of crotoxin, a neurotoxin comprising of two associated components, crotapotin and phospholipase A2 (PLA2). Treatment of the victims with specific antiserum is the unique effective therapeutic measure. The ability of anti-Crotalus antisera produced by the routine using crude venom to immunize horses or purified crotoxin and PLA2 as individual immunogens was compared. Antisera obtained from horses immunized with C. durissus terrificus crude venom were able to recognize and neutralize not only the toxins presents in C. durissus terrificus, but also the ones present in the venoms from C. d. collilineatus, C. d. cascavella and C. d. marajoensis. Antisera from horses immunized with individual crotoxin or PLA2, although in lesser titers, were also able of recognizing the toxins in all four Crotalus species and neutralize the lethality of the C. d. terrificus venom
Crackling Noise, Power Spectra and Disorder Induced Critical Scaling
Crackling noise is observed in many disordered non-equilibrium systems in
response to slowly changing external conditions. Examples range from Barkhausen
noise in magnets to acoustic emission in martensites to earthquakes. Using the
non-equilibrium random field Ising model, we derive universal scaling
predictions for the dependence of the associated power spectra on the disorder
and field sweep rate, near an underlying disorder-induced non-equilibrium
critical point. Our theory applies to certain systems in which the crackling
noise results from avalanche-like response to a (slowly) increasing external
driving force, and is characterized by a broad power law scaling regime of the
power spectra. We compute the critical exponents and discuss the relevance of
the results to experiments.Comment: 27 Latex Pages, 14 eps figure
Absolute Configuration of a Tetrahydrophenanthrene from Heliotropium ovalifolium by LC-NMR of Its Mosher Esters
A new tetrahydrophenanthrene (1, (1R,2R)-1-hydroxy-2-methoxy-6,9-dimethyl-2,3-dihydrophenanthren-4(1H)-one (heliophenanthrone)) has been isolated from the aerial parts of Heliotropium ovalifolium. Its structure was elucidated on the basis of spectroscopic data, and the absolute configuration of the asymmetric centers was determined from LC-NMR data of the Mosher ester derivatives
Fermionic Casimir effect with helix boundary condition
In this paper, we consider the fermionic Casimir effect under a new type of
space-time topology using the concept of quotient topology. The relation
between the new topology and that in Ref. \cite{Feng,Zhai3} is something like
that between a M\"obius strip and a cylindric. We obtain the exact results of
the Casimir energy and force for the massless and massive Dirac fields in the
()-dimensional space-time. For both massless and massive cases, there is a
symmetry for the Casimir energy. To see the effect of the mass, we
compare the result with that of the massless one and we found that the Casimir
force approaches the result of the force in the massless case when the mass
tends to zero and vanishes when the mass tends to infinity.Comment: 7 pages, 4 figures, published in Eur. Phys. J.
- …