scholarly journals THE CIRCUMFUSION SYSTEM FOR MULTIPURPOSE CULTURE CHAMBERS

1967 ◽  
Vol 32 (1) ◽  
pp. 89-112 ◽  
Author(s):  
George G. Rose

A self-contained mechanical system for circulating nutrient fluid through 12 tissue culture chambers is described in detail. This system utilizes nonperforated cellophane membranes in the chambers which separate the circulating nutrient from the tissue culture environments. The nutrient, therefore, is dialyzed through the cellophane of each chamber; some cell products are retained in the microenvironment between the closely apposed cellophane and cover slip, whereas the other cell products move from chamber to chamber in the circulating nutrient. The resultant environmental conditions directed by the circumfusion systems are highly favorable for maintaining the differentiation of chick embryo tissues over protracted periods; a number of micrographs are shown.

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 542
Author(s):  
Dariusz Kulus ◽  
Natalia Miler

Lamprocapnos spectabilis (L.) Fukuhara (bleeding heart) is valued both in the horticultural and pharmaceutical markets. Despite its great popularity, information on the in vitro tissue culture technology in this species is limited. There is also little knowledge on the application of plant extracts in the tissue culture systems of plants other than orchids. The aim of this study is to compare the utility of traditional plant growth regulators (PGRs) and natural extracts—obtained from the coconut shreds, as well as oat, rice, and sesame seeds—in the micropropagation and cryopreservation of L. spectabilis ‘Gold Heart’ and ‘White Gold’. The biochemical analysis of extracts composition is also included. In the first experiment related to micropropagation via axillary buds activation, the single-node explants were cultured for a 10-week-long propagation cycle in the modified Murashige and Skoog medium fortified either with 1.11 µM benzyladenine (BA) and 1.23 µM indole-3-butritic acid (IBA) or with 10% (v/v) plant extracts. A PGRs- and extract-free control was also considered. In the cryopreservation experiment, the same 10% (v/v) extracts were added into the medium during a seven-day preculture in the encapsulation-vitrification cryopreservation protocol. It was found that the impact of natural additives was cultivar- and trait-specific. In the first experiment, the addition of coconut extract favoured the proliferation of shoots and propagation ratio in bleeding heart ‘Gold Heart’. Rice extract, on the other hand, promoted callus formation in ‘White Gold’ cultivar and was more effective in increasing the propagation ratio in this cultivar than the conventional plant growth regulators (4.1 and 2.6, respectively). Sesame extract suppressed the development of the explants in both cultivars analysed, probably due to the high content of polyphenols. As for the second experiment, the addition of plant extracts into the preculture medium did not increase the survival level of the cryopreserved shoot tips (sesame and oat extracts even decreased this parameter). On the other hand, coconut extract, abundant in simple sugars and endogenous cytokinins, stimulated a more intensive proliferation and growth of shoots after rewarming of samples. Analysing the synergistic effect of conventional plant growth regulators and natural extracts should be considered in future studies related to L. spectabilis.


2002 ◽  
Vol 15 (2) ◽  
pp. 205 ◽  
Author(s):  
Christina Flann ◽  
Pauline Y. Ladiges ◽  
Neville G. Walsh

A study of morphological variation in Leptorhynchos squamatus (Labill.) Less. across its range in south-eastern Australia was undertaken to test the hypothesis that L. squamatus includes two taxa. Phenetic pattern analyses of both field-collected and herbarium specimens on the basis of morphology confirmed two major groups. Bract, cypsela, pappus bristle and leaf characters were particularly important in separating the two groups. The taxa are separated by altitude differences with one being a low-altitude plant found in many habitats and the other being a high-altitude taxon that is a major component of alpine meadows. Lowland plants have dark bract tips, fewer and wider pappus bristles than alpine plants, papillae on the cypselas and more linear leaves. A somewhat intermediate population from the Major Mitchell Plateau in the Grampians shows some alpine and some lowland characters but is included in the lowland taxon. Seeds from five populations (two alpine, two lowland and Major Mitchell) were germinated and plants grown for 18 weeks under four controlled sets of environmental conditions. The experiment showed that leaf size and some other characters are affected by environmental conditions, but that there are underlying genetic differences between the lowland and alpine forms. Leptorhynchos squamatus subsp. alpinus Flann is described here to accommodate the highland taxon.


Author(s):  
Ekta Sharma

The Presented summary paper target is to draw the attention of the public to the benefits of Environment and how we are connected to the Environment. To show that if there’s any change in the Environmental conditions, then how the conditions change in human beings lives. Living Being, whether a Human Being or Animals or plants,  are all directly or indirectly Dependent on the Environment for their Survival. When asked truly it can be said that none of the living being can survive without the presence of Environment. It is difficult to find absolutely natural environments, and it is common that the naturalness varies in a continuum, from ideally 100% natural in one extreme to 0% natural in the other. More precisely, we can consider the different aspects or components of an environment, and see that their degree of naturalness is not uniform.


1961 ◽  
Vol 39 (5) ◽  
pp. 925-932 ◽  
Author(s):  
Helen J. Morton ◽  
Joseph F. Morgan

Seventeen structurally related compounds were tested for their ability to substitute for phenylalanine or tyrosine in the nutrition of chick embryo heart fragments. DL-Alanyl-DL-phenylalanine replaced phenylalanine. All other compounds had negligible effects, and most were toxic at high concentrations. β-Phenylserine, a phenylalanine antagonist, actually prolonged the survival of chick heart cells but only if both phenylalanine and tyrosine were present. Similarly, optimal reversal of β-phenylserine toxicity was dependent on the presence of both amino acids. Although phenylalanine and tyrosine are not interconvertible in the present system, it has been shown that three phenylalanine antagonists, p-fluorophenylalanine, β-2-thienylalanine, and β-phenylserine, can be identified by their relationship to tyrosine, rather than to phenylalanine.


1975 ◽  
Vol 19 (3) ◽  
pp. 301-304
Author(s):  
Ann E. Martin

The present study was conducted to investigate the effects of environmental conditions on visual workload. The environmental variables used were temperature, studied at levels of 45°F., WBGT, and 95°F., WBGT; and noise, studied at 83 dBA intermittent noise and 93 dBA continuous noise. Workload was defined as the amount of attention demanded from an operator as measured by performance decrement on a secondary task while performing a primary and secondary task simultaneously. The secondary task was reading random numbers, and the primary task was reading word lists. Significant differences (p<.05) were found between the control condition and all experimental conditions. The low temperature and high temperature-continuous noise conditions were significantly different from the other conditions. Noise and temperature were found to significantly increase workload (p<05).


2019 ◽  
Vol 188 (3) ◽  
pp. 860-864 ◽  
Author(s):  
Harry A Meyer ◽  
Hannah E Larsen ◽  
Nézira O Akobi ◽  
Garret Broussard

Abstract Tardigrade behavioural studies have focused on responses to abiotic environmental conditions. Predator–prey interactions have received some attention, but not how predators and prey might detect one another. Here, we investigate whether a predatory tardigrade species is attracted to, and a potential prey tardigrade avoids, areas previously occupied by the other. In our experiments, Milnesium lagniappe was the predator and Macrobiotus acadianus the prey. Petri dishes with non-nutrient agar were used as experimental arenas. In one treatment, we allowed Macrobiotus to roam over half of the agar for 20 h, while leaving the other half free of Macrobiotus. We then removed the prey and introduced the predator. In the control treatment, no prey were added. Results indicated that Milnesium individuals were significantly concentrated in the area previously occupied by Macrobiotus, whereas no such concentration was evident when Macrobiotus had not been present. A similar protocol was used to test whether Macrobiotus avoided areas previously occupied by the predator. As expected, Macrobiotus were significantly concentrated in the area never occupied by Milnesium, unlike the control treatment. These results suggest that both species can detect the other without physical contact and react accordingly. Given that the experiments were conducted in darkness, detection is probably olfactory.


2014 ◽  
Vol 16 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Martyna Kandefer-Szerszeń ◽  
Zbigniew Kawecki ◽  
Bogusław Sałata ◽  
Maria Witek

Water extracts the fructifications of 56 species of fungi were examined as a source of antiviral substances with activity against VS and vaccinia viruses. Extracts from 16 fungal species exhibited the antiviral activity. Water extracts from <i>Boletus edulis</i> active against vaccinia virus and extract from <i>Armillariella mellea</i> active against VS virus are particularly worth nothing. Both of them in applied concentrations were not toxic in chick embryo fibroblasts tissue culture.


2007 ◽  
pp. 55-67 ◽  
Author(s):  
Slobodan Milanovic

The development of Gypsy moth (Lymantria dispar L) was monitored in laboratory conditions, on the foliage of the species Quercus cerris L. Quercus petraea (Matt) Liebl. and Quercus robur L. The experiment was established in the controlled environmental conditions, at the temperature of 25?C, photoperiod 14:10 (day: night) and relative humidity 70%. The objective of the research was to determine the suitability of the study host plant species for gypsy moth development. The study results show that Gypsy moth caterpillars cultivated on Q. petraea foliage had a lower survival, higher number of moultings, longer preadult development and lower fecundity, which makes this species less suitable compared to the other two. Gypsy moth caterpillars cultivated on Q. cerris foliage had the highest survival degree the lowest number of moultings, the shortest preadult development and the highest fecundity, which makes this species the most favourable for gypsy moth development. Q. robur was between the former two species in this respect.


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