Controlling vitrification in Larixdecidua via culture media manipulation

1989 ◽  
Vol 19 (10) ◽  
pp. 1334-1337 ◽  
Author(s):  
J. McLaughlin ◽  
D. F. Karnosky

Vitrification rates obtained from our inverted embryo system were significantly decreased by lowering the cytokinin concentrations in Brown and Lawrence medium containing 10 mM L-glutamine from 10 to 1 mg/L, or by replacing 10 mM L-glutamine with equimolar concentrations of Ca(NO3)2 or by adding 1 g/L Gelrite to the normal 10 g/L Difco–Bacto agar in the culture media. In all treatments, decreased vitrification was accompanied with decreased adventitious bud production. With reduced N6-benzylaminopurine, vitrification decreased from 77 to 29%, but bud production decreased from 61 to 17 buds per explant and mortality increased from 3 to 33%. Incorporation of Ca(NO3)2 into the media decreased vitrification from 87 to 21%, but the number of adventitious buds per embryo decreased from 75 to 42. Vitreous shoots were reverted to normal development with an 81% reversion frequency and a 6% mortality rate by culturing these shoots on Gresshof and Doy medium with one-half total nitrogen. Elongation of previously vitreous shoots was best when these shoots were cultured on Gresshof and Doy medium + 0.5 mg/L N6-benzylaminopurine for 2 weeks, followed by subculture on Gresshof of and Doy medium + 10 g/L charcoal.

2002 ◽  
Vol 104 (1) ◽  
pp. 116-126 ◽  
Author(s):  
Melissa Campbell

In June 1997, 13-month-old Jaidyn Leskie disappeared from Moe, a rural Victorian town. His body was found in January 1998. Through a discussion of three presentations of ‘loss’, this paper contends those involved in the case were constructed by the media as ‘bogans' — powerless outsiders — because they defied categorisation within narrow conceptions of ‘normal Australian society’. While Jaidyn himself was a ‘lost child’, his family and associates were likened to a ‘lost tribe’, whose alliances, feuds and kinship networks became exotic, exploitative entertainment. Lacking rhetorical tools to ‘explain’ such a distinctive culture, media coverage constructed bogans as victims of failed social policy: their culture ‘caused’ by economic downsizing, unemployment, drug use and single parenthood. Finally, when members of Jaidyn's family accepted money for media interviews, they were painted as ‘losing their innocence’. This reveals insecurities underpinning the concept ‘bogan’: evidently, bogans were not supposed to engage in media manipulation themselves.


Weed Science ◽  
2007 ◽  
Vol 55 (4) ◽  
pp. 346-351 ◽  
Author(s):  
Russ W. Gesch ◽  
Debra Palmquist ◽  
James V. Anderson

Previous evidence indicates that changes in well-defined phases of dormancy in underground adventitious buds of leafy spurge in late summer and autumn are regulated by complex sensing and signaling pathways involving aboveground sugar signals. However, little information exists concerning seasonal photosynthesis and carbohydrate partitioning of leafy spurge, although such information would help to elucidate the involvement of sugar in controlling bud dormancy. An outdoor study was conducted over two growing seasons to determine and model seasonal patterns of photosynthesis and aboveground carbohydrate partitioning and their relationship to underground adventitious bud carbohydrate status. Photosynthesis and total nonstructural carbohydrate (TNC) content of aboveground tissues was greatest during vegetative growth. Photosynthesis gradually declined over the growing season, whereas TNC decreased sharply during flowering, followed by a gradual decline between midsummer and autumn. Leaf starch increased dramatically to midsummer before declining sharply throughout late summer and early autumn, whereas sucrose content responded inversely, indicating a mobilization of starch reserves and export of sugars to overwintering belowground sink tissues. Because newly formed underground adventitious buds showed a continuous increase in TNC from midsummer through autumn, export of sugars from aboveground tissues likely contributed to the increase in TNC. These results may facilitate new strategies for biological control of leafy spurge.


2007 ◽  
Vol 7 ◽  
pp. 525-532
Author(s):  
Qing Guo ◽  
Zao-he Wu ◽  
Ming-liang Qian ◽  
Binhe Gu

The purpose of this study was to investigate the roles of coral sands in the enrichment and isolation of ammonium-oxidizing bacteria (AOB). We hypothesized that the porous coral sands provided additional surface area and nutrients for the growth of periphytic AOB. In the present study, an orthogonal test was designed to compare the AOB conversion rates of ammonium-nitrogen (NH4+N) to nitrite-nitrogen (NO2--N) among various combinations of culture media. Results showed that the conversion of NH4+N to NO2--N increased significantly when the coral sands were added, implying that coral sands were beneficial to the growth of AOB. Additions of potassium dihydrogen phosphate (KH2PO4) or sodium bicarbonate (NaHCO3) to the media became unnecessary when coral sands were used, but the addition of KH2PO4was needed when the molar nitrogen to phosphorus (N:P) ratio reached 10 in the enrichment media using calcium carbonate (CaCO3) powder as a calcium source.


Author(s):  
Gabriela de Oliveira Fernandes ◽  
Marcella Pecora Milazzotto ◽  
Andrei Antonioni Guedes Fidelis ◽  
Taynan Stonoga Kawamoto ◽  
Ligiane de Oliveira Leme ◽  
...  

Abstract The present study aimed to identify biomarkers to assess the quality of in vitro produced (IVP) bovine embryos in the culture media. IVP embryos on Day (D) 5 of development were transferred to individual drops, where they were maintained for the last 48 h of culture. Thereafter, the medium was collected and the embryos were transferred to the recipients. After pregnancy diagnosis, the media were grouped into the pregnant and nonpregnant groups. The metabolic profiles of the media were analyzed via electrospray ionization mass spectrometry, and the concentrations of pyruvate, lactate, and glutamate were assessed using fluorimetry. The spectrometric profile revealed that the media from embryos from the pregnant group presented a higher signal intensity compared to that of the nonpregnant group; the ions 156.13 Da [M + H]+, 444.33 Da [M + H]+, and 305.97 Da [M + H]+ were identified as biomarkers. Spent culture medium from expanded blastocysts (Bx) that established pregnancy had a greater concentration of pyruvate (p = 0.0174) and lesser concentration of lactate (p = 0.042) than spent culture medium from Bx that did not establish pregnancy. Moreover, pyruvate in the culture media of Bx can predict pregnancy with 90.9% sensitivity and 75% specificity. In conclusion, we identified markers in the culture media that helped in assessing the most viable IVP embryos with a greater potential to establish pregnancy.


HortScience ◽  
2018 ◽  
Vol 53 (10) ◽  
pp. 1487-1493 ◽  
Author(s):  
Doina Clapa ◽  
Claudiu Bunea ◽  
Orsolya Borsai ◽  
Adela Pintea ◽  
Monica Hârța ◽  
...  

The current research was carried out to investigate the effects of iron source in the culture media for Vaccinium corymbosum L. ʻBluerayʼ, ʻDukeʼ, and ʻPatriotʼ cultivars grown on five different types of medium (Woody Plant Medium supplemented with 1.0 mg·L−1 zeatin and 0, 25, 50, 75, and 100 mg·L−1 Sequestrene 138). After 10 weeks of culture, seven physiological parameters were measured, such as the number and length of axillary shoots, rooting and acclimatization percentage, as well as chlorophyll (a, b, a/b) and carotenoid content of the leaves. Adding Sequestrene 138 to the culture media led to a slight decrease of the proliferation rate but increased the length of the shoots. The chlorophyll and carotenoid content in all of the three cultivars was considerably increased as the iron concentration of the media increased. The shoots developed on the Sequestrene 138–free medium were chlorotic and short, whereas at different concentrations of iron in the culture medium the shoots were dark green and vigorous, providing a greater acclimatization success than those grown in iron-free medium.


1994 ◽  
Vol 40 (1) ◽  
pp. 28-34 ◽  
Author(s):  
P. H. Goodwin ◽  
C. R. Sopher

The diffusible brown pigment produced by some strains of Xanthomonas campestris pv. phaseoli was found to be due to the secretion and subsequent oxidation of homogentisic acid (2, 5-dihydroxyphenylacetic acid) rather than tyrosinase activity as previously reported. Homogentisic acid is an intermediate in tyrosine catabolism for a number of bacteria. Brown-pigmented strains appeared to be disrupted in tyrosine catabolism and could not use tyrosine as a nutrient. Nonpigmented strains, however, could utilize tyrosine as a nutrient, and although they secreted homogentisic acid, the levels were approximately 1/100th that of brown-pigmented strains. Production of brown pigment was stimulated by tyrosine and repressed by glucose. Growth in glucose resulted in a drop in the pH of the media, and the greatest pigment formation was associated with a shift to alkaline conditions in the culture media. By buffering the media near pH 7.0, brown pigment formation was repressed, even though unoxidized homogentisic acid accumulated in the culture media. The disruption of tyrosine catabolism corresponds to other reports describing differences between brown-pigmented and nonpigmented strains, and provides further support for the retention of a special taxonomic status for the brown-pigmented strains.Key words: homogentisic acid, pigments, Xanthomonas, fuscans.


Author(s):  
Urszula Panicz

The aim of the article is to solve the problem, whether the media is responsible for the decline in the quality of a public debate. The comparison of media transmission has led to the conclusion that media was especially critically oriented towards PiS what brought about its politicization. The idea of Marcin Król is used in order to describe the reasons of media manipulation. The measure that could lead to the end of such conflicts has been suggested. That is deliberative democracy.


2008 ◽  
Vol 28 ◽  
pp. 343-359 ◽  
Author(s):  
Audrey Haynes

This paper examines the research in media and presidential nomination campaigns as it has emerged during the post-reform era and moved into the new millennia. While there has been ample progress in the field, most notable has been the change in tone in the research from “bad” news to “good” news. Interpretations from the most recent research in the area suggest that the news media do not perform as poorly as judged in the earlier decades, at least in terms of providing information to voters. Moreover, voters are now portrayed not as naïve citizens who are easily manipulated by the media, but rather more resilient to media manipulation, and active consumers of information for political learning purposes.


2020 ◽  
Vol 9 (S1-i2-Dec) ◽  
pp. 1-4
Author(s):  
K Premanand ◽  
M Kasirajan

The growth of technology has given the viability to media, which has emerged as ‘the third eye for humans to comprehend the world. The people are too dependent onthese technologies, where they have forgotten their real nature of life. Because of global surveillance, technology has become a double-edged sword, where individual privacy is been lost. Moreover, people have exchanged their precious gift of freedom for the technology, which has become the manacle that restrains them to the core these days. The media is used as a tool to manipulate the thought process of the people in this digital era. The politicians are using these strings to make the people as the puppets, they induce the thought within people and restrict them from thinking beyond. This paper attempts to study the effects of Global surveillance and Media manipulation through George Orwell’s 1984.


2020 ◽  
Author(s):  
Mariana Ferdes ◽  
Rodica Roxana Constantinescu

The chrome shavings waste obtained as a result of the leather finishing process accumulates in a large volume in tanneries and represent a major problem for the environment. This waste are particularly resistant to attack of microorganisms, due to the significant concentration of chromium and are thus difficult to degrade. In this study, chrome shavings were analyzed microbiologically by determining the total number of germs and the number of yeasts and molds on specific culture media. Several bacterial and fungal strains were isolated from the cultures in Petri dishes, after the growth of the colonies. These strains were characterized in terms of the production of proteolytic enzymes, by a method of screening on the media with casein, which allows the determination of proteolytic indices of microorganisms. As a result of the tests performed, five bacterial strains probably belonging to the genus Bacillus and two fungal strains from the genera Penicillium and Cladosporium were selected.


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