Influence of Certain Substances on the Fluidity of the Cytoplasm and the Fertilizability of the Egg of the Sea-urchin, Psammechinus miliaris

Development ◽  
1953 ◽  
Vol 1 (3) ◽  
pp. 319-325
Author(s):  
Elsa Wicklund ◽  
Georg Kriszat ◽  
John Runnström

After nuclear maturation the eggs of Psammechinus (Ps.) miliaris are still ‘underripe’ with respect to their cytoplasm. This phenomenon is particularly conspicuous in Ps. miliaris from the Swedish west coast (see, for a summary, Runnström, 1949). In the small individuals of Ps. miliaris dredged from a depth of 30–40 metres this state of underripeness may last for months, so that full cytoplasmic maturity may be reached only in the latter half of August (Lindahl & Runnström, 1929). The littoral form of Ps. miliaris, on the other hand, has already attained cytoplasmic maturity in the latter half of June. Temperature conditions evidently play a decisive role in the phenomenon. The swelling of the jelly coat surrounding the egg certainly plays an important role in the process of ‘cytoplasmic’ maturation. Removal of the jelly coat sometimes improves fertilization, but not always. This latter fact proves that the state of underripeness resides also in the cytoplasm itself.

1970 ◽  
Vol 52 (2) ◽  
pp. 455-468
Author(s):  
R. PRESLEY ◽  
P. F. BAKER

1. A method is described for the direct counting of male pronuclei in recently fertilized sea-urchin eggs. 2. Using this method, fertilization rate determinations were made to compare 30% artificial sea water (A.S.W.), isotonic KCl, sea water containing lauryl sulphate, calcium-free and magnesium-free A.S.W. containing EDTA, and sea water containing uranyl nitrate, as agents blocking fertilization but permitting further development of previously fertilized eggs. 3. 30% A.S.W. was found to be less satisfactory than the other agents, lacking instant effect, and tending to promote polyspermy. The other agents all gave sigmoid rate curves, that of uranyl nitrate lagging 15-25 sec. behind the others. 4. Evidence was found that uranyl nitrate acts at a later stage in fertilization than the other agents. 5. Sigmoid rate curves were found, except with 30% A.S.W., when eggs with the bulk of the jelly coat removed, and nicotine-treated eggs, were fertilized. 6. Analysis of sperm distribution among eggs from samples fertilized for more than 40 sec. confirmed that re-fertilization takes place at a lower rate than primary fertilization. 7. The processes blocked by KCl and uranyl nitrate were found to precede the cortical responses to fertilization, and the termination of nicotine sensitivity.


Reproduction ◽  
2006 ◽  
Vol 131 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Jason R Herrick ◽  
Amber M Brad ◽  
Rebecca L Krisher

The objectives of this study were to manipulate metabolism of glucose through glycolysis and the pentose phosphate pathway (PPP) in porcine oocytes during in vitro maturation, and determine the effects of this manipulation on meiotic progression, intracellular glutathione (GSX) concentrations and embryonic development. Cumulus-oocyte complexes isolated from abattoir ovaries were matured (40–44 h) in Purdue Porcine Medium for maturation alone (control) or supplemented with pyrroline-5 carboxylate (PC, 0.1 μM; PPP stimulator), diphenyleneiodonium (DPI, 0.1 μM; PPP inhibitor), dinitrophenol (DNP, 10 μM; glycolytic stimulator), hexametaphosphate (HMP, 100 μM; glycolytic inhibitor), PC + HMP or DNP + DPI. At the conclusion of in vitro maturation, cumulus cells were removed and oocytes were randomly allocated for analysis of GSX, metabolism and nuclear maturation, or in vitro fertilization and embryo culture. Both DPI and DNP + DPI decreased (P ≤ 0.05) the activity of glycolysis and the PPP, increased (P ≤ 0.05) the percentage of immature oocytes, and decreased (P ≤ 0.05) the proportion of mature oocytes compared with control oocytes and oocytes from the other treatments. Embryonic development (cleavage and blastocyst stage) and the intracellular content of GSX were also decreased (P ≤ 0.05) following exposure to DPI or DNP + DPI compared with control oocytes and oocytes from the other treatments. Oocyte metabolism, nuclear maturation, GSX content and embryonic development were unaffected (P > 0.05) following exposure to PC, DNP, HMP or PC + HMP. Our results suggest that metabolism of glucose through the PPP and/or glycolysis plays a key role in the control of nuclear and cytoplasmic maturation of porcine oocytes in vitro.


2016 ◽  
Vol 6 (2) ◽  
pp. 118-135
Author(s):  
Lucia Della Torre

Not very long ago, scholars saw it fit to name a new and quite widespread phenomenon they had observed developing over the years as the “judicialization” of politics, meaning by it the expanding control of the judiciary at the expenses of the other powers of the State. Things seem yet to have begun to change, especially in Migration Law. Generally quite a marginal branch of the State's corpus iuris, this latter has already lent itself to different forms of experimentations which then, spilling over into other legislative disciplines, end up by becoming the new general rule. The new interaction between the judiciary and the executive in this specific field as it is unfolding in such countries as the UK and Switzerland may prove to be yet another example of these dynamics.


2019 ◽  
Vol 34 (2) ◽  
Author(s):  
Sipho Stephen Nkosi

The note is about the appeal lodged by the late Mrs Winnie Madikizela-Mandela to the SCA against the decision of the Eastern Cape High Court, Mthatha, dismissing her application for review in 2014. In that application, she sought to have reviewed the decision of the Minister of Land Affairs, to transfer the now extended and renovated Qunu property to Mr Mandela and to register it in his name. Because her application was out of time, she also applied for condonation of her delay in making the application. The court a quo dismissed both applications with costs, holding that there had been an undue delay on her part. Mrs Mandela then approached the Supreme Court of Appeal, for special leave to appeal the decision of the court a quo. Two questions fell for decision by the SCA: whether there was an unreasonable and undue delay on Mrs Mandela’s part in instituting review proceedings; and whether the order for costs was appropriate in the circumstances of the case. The SCA held that there was indeed an unreasonable delay (of seventeen years). Shongwe AP (with Swain, Mathopo JJA, Mokgothloa and Rodgers AJJA concurring) held that the fact that there had been an undue delay does not necessarily mean that an order for costs should, of necessity, particularly where, as in this case, the other litigant is the state. It is the writer’s view that two other ancillary points needed to be raised by counsel and pronounced on by the Court: (a) the lawfulness and regularity of the transfer of the Qunu property to Mr Mandela; and (b) Mrs Mandela’s status as a customary-law widow—in relation to Mr Mandela.


2017 ◽  
Vol 1 (1) ◽  
pp. 90
Author(s):  
Dian Septiandani ◽  
Abd. Shomad

Zakat is one of principal worship requiring every individual (<em>mukallaf</em>) with considerable property to spend some of the wealth for zakat under several conditions applied within. On the other hand, tax is an obligation assigned to taxpayers and should be deposited into the state based on policies applied, with no direct return as reward, for financing the national general expense. In their development, both zakat and tax had quite attention from Islamic economic thought. Nevertheless, we, at first, wanted to identify the principles of zakat and tax at the time of Rasulullah SAW. Therefore, this study referred to normative research. The primary data was collected through library/document research and the secondary one was collected through literature review by inventorying and collecting textbooks and other documents related to the studied issue.


Author(s):  
K. E. Stupak ◽  

The article deals with analyzing the main streams of the education policy in Finland, which reflect the relationship between a person and society in modern socio–economic conditions. Such policy directs the system of education to change the person and his mind himself. Finland using its education system, has long before been concerned about preparing people for the future by reforming approaches to teaching in schools and higher education institutions. As a result, it has achieved world–wide recognition and top positions in various ratings have resulted. Therefore, today there is a great interest of scientists in certain issues of education functioning in Finland. Thus, G. Androshchuk, V. Butova. I. Zhernokleeva, T. Pushkareva and others study in their works the purpose and decisive role of Finland's education policy in the development of the education system. S. Grinyuk and V. Zagvozdkin pay attention to the practical the steps of reforming the Finnish system of education. T. Drobyshevsk investigates the system of providing educational services in Finland as a sector of knowledge production. L. Volynets, P. Kukharchuk consider the principles of the state education policy of Finland. L. Smolskaya examines the role of the state policy in implementing the "Finnish phenomenon"; P. Basyliuk and Yu. Kulykova, focus attention on the study of the evolution of the system of higher education in Finland; O. Scherbak reveals peculiarities of vocational education and training.


Author(s):  
Anatolii Petrovich Mykolaiets

It is noted that from the standpoint of sociology, “management — a function of organized systems of various nature — (technical, biological, social), which ensures the preservation of their structure, maintaining a certain state or transfer to another state, in accordance with the objective laws of the existence of this system, which implemented by a program or deliberately set aside”. Management is carried out through the influence of one subsystem-controlling, on the other-controlled, on the processes taking place in it with the help of information signals or administrative actions. It is proved that self-government allows all members of society or a separate association to fully express their will and interests, overcome alienation, effectively combat bureaucracy, and promote public self-realization of the individual. At the same time, wide direct participation in the management of insufficiently competent participants who are not responsible for their decisions, contradicts the social division of labor, reduces the effectiveness of management, complicates the rationalization of production. This can lead to the dominance of short-term interests over promising interests. Therefore, it is always important for society to find the optimal measure of a combination of self-management and professional management. It is determined that social representation acts, on the one hand, as the most important intermediary between the state and the population, the protection of social interests in a politically heterogeneous environment. On the other hand, it ensures the operation of a mechanism for correcting the political system, which makes it possible to correct previously adopted decisions in a legitimate way, without resorting to violence. It is proved that the system of social representation influences the most important political relations, promotes social integration, that is, the inclusion of various social groups and public associations in the political system. It is proposed to use the term “self-government” in relation to several levels of people’s association: the whole community — public self-government or self-government of the people, to individual regions or communities — local, to production management — production self-government. Traditionally, self-government is seen as an alternative to public administration. Ideology and practice of selfgovernment originate from the primitive, communal-tribal democracy. It is established that, in practice, centralization has become a “natural form of government”. In its pure form, centralization does not recognize the autonomy of places and even local life. It is characteristic of authoritarian regimes, but it is also widely used by democratic regimes, where they believe that political freedoms should be fixed only at the national level. It is determined that since the state has achieved certain sizes, it is impossible to abandon the admission of the existence of local authorities. Thus, deconcentration appears as one of the forms of centralization and as a cure for the excesses of the latter. Deconcentration assumes the presence of local bodies, which depend on the government functionally and in the order of subordination of their officials. The dependency of officials means that the leadership of local authorities is appointed by the central government and may be displaced.


2016 ◽  
Vol 1 (1) ◽  
Author(s):  
D.G. Shah ◽  
D.N. Mehta ◽  
R.V. Gujar

Bryophytes are the second largest group of land plants and are also known as the amphibians of the plant kingdom. 67 species of bryophytes have been reported from select locations across the state of Gujrat. The status of family fissidentaceae which is a large moss family is being presented in this paper. Globally the family consists of 10 genera but only one genus, Fissidens Hedw. has been collected from Gujarat. Fissidens is characterized by a unique leaf structure and shows the presence of three distinct lamina, the dorsal, the ventral and the vaginant lamina. A total of 8 species of Fissidens have been reported from the state based on vegetative characters as no sporophyte stages were collected earlier. Species reported from the neighboring states also showed the absence of sporophytes. The identification of different species was difficult due to substantial overlap in vegetative characters. Hence a detailed study on the diversity of members of Fissidentaceae in Gujarat was carried out between November 2013 and February 2015. In present study 8 distinct species of Fissidens have been collected from different parts of the state. Three species Fissidens splachnobryoides Broth., Fissidens zollingerii Mont. and Fissidens curvato-involutus Dixon. have been identified while the other five are still to be identified. Fissidens zollingerii Mont. and Fissidens xiphoides M. Fleisch., which have been reported as distinct species are actually synonyms according to TROPICOS database. The presence of sexual reproductive structures and sporophytes for several Fissidens species are also being reported for the first time from the state.


2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Vinay Chauhan ◽  
Sushma Kaushal

Environmental scanning yields greater anticipatory management that provides important inputs for aquitision and use of information for planning and designing organization strategies. Apart from this, effective environmental scanning activities are likely to deal with threats and grasp the opportunities to finally link with enhancing organizational effectiveness. In fact this relationship matrix has led the researchers to conduct an environmental scanning through an examination of the existing status the components of the macro-environment vis-a-vis their relationship with the organizational effectiveness. There are a number of approaches, which describe the macro-environment, of which PEST analysis is regarded as the most common approach for considering the external business environment. Thus, the present study applies PEST analysis to scan the existing business environment. Jammu and Kashmir due to its peculiar political, geographical, economic, and socio-cultural features, had led its cost mountain economy become a distinctive identity. Despite the fact that the state has rich endowments, international relations with its neighbours vis-a-vis its impact on political environment also pose developmental challenges for the business units operating in the state. This has provided valid rationale for conducting the present. The environmental scanning is done through the perception of the select entrepreneurs operating MSMEs in the state of J & K. An impact analysis of environmental factors (PEST) on the organizational effectiveness is also done in the study. The findings of the study show that the political environment of the state that is not favourable for entrepreneural development whereas the rest of the other drivers of PEST i.e. economic environment, socio-cultural environment, and technological environment show a favourable response of the entrepreneurs. In terms of cause and effect relationship, it is found that the first two drivers of the PEST i.e. political and economic dimension impacts OE positively whereas the other two dimensions namely socio-cultural and technological impacts OE negatively but it is pertinent to mention that the impact is very less and is insigninificant. The study also suggests some of strategic options for developing and creating an enabling environment for successful entrepreneurial development to achieve integrated development of the state.


Author(s):  
Dunja Apostolov-Dimitrijevic

This paper explains political democratization in Post-Milosevic Serbia, utilizing two different accounts of the democratization process: one rooted in the rational choice framework and the other in structuralism. While rational choice explains the decisive role of political leadership in overcoming path dependence, the structuralist explanations show the transnational linkages that encourage democratization in the face of domestic setbacks. This particular debate between the two types of explanations represents the larger debate concerning the role of internal factors and external linkages in propelling democratization in transitional societies. The paper concludes by integrating the two sets of explanations offered by each theoretical perspective, in order to develop a coherent understanding of Serbia's democratization.   Full text available at: https://doi.org/10.22215/rera.v9i1.240


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