scholarly journals Tissues development in stems of Aristolochia clematitis L. in the point of view of multicellular complexes formation

2014 ◽  
Vol 51 (1) ◽  
pp. 107-125 ◽  
Author(s):  
Zofia Puławska

After cytokinesis the cells do not separate but remain within the wall of the mother cell. After a series of divisions a multicellular complex arises. In the stems of <em>Aristolochia clematitis</em> procambium is closer related to protoxylem than to protophloem, and metaphloem is closer related to metaxylem than to protophloem. Since protophloem has a closer common origin with fibre primordia than with the remaining tissues, it cannot be decided unequivocally what is the origin of the fibres or when procambium differentiates. The common origin of the primary vascular tissues is visible in the pattern of the multicellular complexes, whereas the common origin of the secondary vascular tissue developing in the underground several-year-old parts of the stem can be traced in the arrangement of the single radial tiers. Some characteristics of symplastic growth are discussed.

Author(s):  
Mireia López-Bertran

This chapter explores the funerary rites in the Phoenician-Punic world from a comprehensive point of view, and it focuses on the common points arising from a large amount of data. The concern for burying their deceased and the belief in the soul’s afterlife show that the Phoenicians considered death as a transformation rather than as the end of a person’s life. Through our access to archaeological remains and written sources, we can reconstruct the existence of a meaningful burial program that was destined to provide a “good death” and afterlife. Funerary rituals, thus, are the actions or gestures to achieve this goal. The aim of this chapter is to explain the rites that family members undertook once someone died, in order to transform correctly the deceased person into an otherworldly being, the ancestor. The social implications of the data arising from burials are also briefly considered.


1917 ◽  
Vol 4 (6) ◽  
pp. 249-256
Author(s):  
Herbert L. Hawkins

The characters of the apical system of a series of Holectypus hemisphæricus from the same horizon at two localities in Dorsetshire are analysed and described. It is found that the average relations of the plates of the system are different at the two localities, although certain numbers of identical forms occur at both. Out of 189 specimens (from both localities), 40 show serious departures from the normal type. These abnormalities are of three classes. One, the most prevalent, consists in the presence of madreporic pores on genital 3, in addition to the normal perforation of genital 2. This is regarded as a “progressive variant” in the direction of Discoides. The second, occurring in three specimens, consists in the interpolation of a supernumerary plate within the system. It is suggested that this may be either a “regressive variant” towards Acrosalenia, or a “progressive variant” towards Nucleolites (as illustrated by N.orlicularis). In neither case would this variation coincide with actual phyletic sequence, so that it is styled “parallel variation”. The third type of variant, seen in one specimen only, combines both the first and second types, and in addition shows an absence of genital 5 and a corresponding increase in the size of the posterior oculars, which meet round the back of the system. The variation in this specimen is interpreted as being “progressive” towards Discoides, “parallel progressive” or “regressive” towards Nucleolites or Acrosalenia respectively, and “progressive” towards Conulus. There are indications of a different series of variants in the Holectypus depressus from the Cornbrash. The high percentage of variation in the composition of the apical system of Holectypus is regarded as an indication of the evolutional activity of the genus, and of its near approximation in time and phylogeny to the common origin of many of the groups of Irregular Echinoids.


1983 ◽  
Vol 38 (5-6) ◽  
pp. 501-504 ◽  
Author(s):  
Mária Ujhelyi

Seryl tRNA (anticodon GCU) from mammalian mito­chondria shows in comparison to other mitochondrial tRNAs additional special features differing from the generalized tRNA model. When arranged in the tradi­tional cloverleaf form, eight bases fall within the TΨC loop, and the entire dihydrouridine loop is lacking. This seryl tRNA molecule is therefore shorter than other tRNAs. It was originally thought to represent a mito­chondrial analogon of 5 S rRNA and its precise classifica­tion is still disputed. The present studies suggest that this mitochondrial tRNA represents a fossil molecule which is related to the common ancestor of the present tRNA and 5 S rRNA molecules.


Mathematics ◽  
2021 ◽  
Vol 9 (16) ◽  
pp. 1835
Author(s):  
Antonio Barrera ◽  
Patricia Román-Román ◽  
Francisco Torres-Ruiz

A joint and unified vision of stochastic diffusion models associated with the family of hyperbolastic curves is presented. The motivation behind this approach stems from the fact that all hyperbolastic curves verify a linear differential equation of the Malthusian type. By virtue of this, and by adding a multiplicative noise to said ordinary differential equation, a diffusion process may be associated with each curve whose mean function is said curve. The inference in the resulting processes is presented jointly, as well as the strategies developed to obtain the initial solutions necessary for the numerical resolution of the system of equations resulting from the application of the maximum likelihood method. The common perspective presented is especially useful for the implementation of the necessary procedures for fitting the models to real data. Some examples based on simulated data support the suitability of the development described in the present paper.


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 557
Author(s):  
Irene Mariñas-Collado ◽  
Elisa Frutos Bernal ◽  
Maria Teresa Santos Martin ◽  
Angel Martín del Rey ◽  
Roberto Casado Vara ◽  
...  

The knowledge of the topological structure and the automatic fare collection systems in urban public transport produce many data that need to be adequately analyzed, processed and presented. These data provide a powerful tool to improve the quality of transport services and plan ahead. This paper aims at studying, from a mathematical and statistical point of view, the Barcelona metro network; specifically: (1) the structural and robustness characteristics of the transportation network are computed and analyzed considering the complex network analysis; and (2) the common characteristics of the different subway stations of Barcelona, based on the passenger hourly entries, are identified through hierarchical clustering analysis. These results will be of great help in planning and restructuring transport to cope with the new social conditions, after the pandemic.


2001 ◽  
Vol 11 (4) ◽  
pp. 311-321
Author(s):  
DN Carmichael ◽  
Michael Lye

Heart failure has been defined in many ways and definitions change over time. The multiplicity of definitions reflect the paucity of our understanding of the primary underlying physiology of heart failure and the many diseases for which heart failure is the common end-point. Fundamentally, heart failure represents a failure of the heart to meet the body’s requirement for blood supply for whatever reason. It is thus a clinical syndrome with characteristic features – not a single disease in its own right. The syndrome includes symptoms and signs of organ underperfusion, fluid retention and neuroendocrine activation. The syndrome arises from a range of possible causes of which ischaemic heart disease is the commonest. From the point of view of a clinician, the underlying pathology will determine treatment options and prognosis. The extensive range of possible aetiologies present a diagnostic challenge both to correctly identify the syndrome amongst all other causes of dyspnoea and to identify the aetiology, allowing optimization of treatment.


Management ◽  
2014 ◽  
Vol 18 (1) ◽  
pp. 473-487
Author(s):  
Andrzej Czyżewski ◽  
Sebastian Stępień

Summary The objective of the paper is to present the results of negotiations on the EU budget for 2014-2020, with particular emphasis on the Common Agricultural Policy. Authors indicate the steps for establishing the budget, from the proposal of the European Commission presented in 2011, ending with the draft of UE budget agreed at the meeting of the European Council on February 2013 and the meeting of the AGRIFISH on March 2013 and then approved by the political agreement of the European Commission, European Parliament and European Council on June 2013. In this context, there will be an assessment of the new budget from the point of view of Polish economy and agriculture.


Acta Juridica ◽  
2021 ◽  
Vol 2021 ◽  
pp. 85-106
Author(s):  
J Barnard-Naudé

This paper is a response to Dale Hutchison’s recent arguments about the role of fairness in contract law after the Constitution. From the point of view of transformative constitutionalism, the paper argues that the fairness ‘debate’ in the South African law of contract should be approached as what it so patently is, namely, as evidence of a deep ideological conflict that has existed in our law of contract for a very long time, and that this debate now exists within the context of a larger debate about the appropriate transformative reach of the Constitution. The argument takes the form of two ‘dangerous supplements’ to Hutchison’s discourse. The first of these supplements contends that indeterminacy is a symptom of the common law itself, rather than a result of contract law’s contact with the Constitution. The second dangerous supplement suggests a responsible judicial engagement with bona fides and ubuntu, one that can exploit the strengths of both the common law and the Constitution and that understands good faith and ubuntu to be ‘inter-linking’ constitutional values that should be enlisted in unison or at least in resonance when it comes to the question of fairness in our contemporary law of contract. In conclusion, I offer a reading of Hutchison’s own politics of contract law and contend that his is an altruistic politics committed to the standard form. I contend that this politics of contract law is consistent with a transformative understanding of the post-apartheid legal order. ‘Law, like every other cultural institution, is a place where we tell one another stories about our relationships with ourselves, one another, and authority. In this, law is no different from the Boston Globe, the CBS evening news, Mother Jones, or a law school faculty meeting. When we tell one another stories, we use languages and themes that different pieces of the culture make available to us, and that limit the stories we can tell. Since our stories influence how we imagine, as well as how we describe, our relationships, our stories also limit who we can be’.


2021 ◽  
Vol 1 (1) ◽  
pp. 9-16
Author(s):  
Khamidulla Dadaboyev ◽  

This article is devoted to the analysis of the semantic structure of the common Turkic word “tortmoq” “pull, drag” on the example of factual materials recorded in the ancient Turkic, Old Turkic and Old Uzbek written monuments. The analysis showed that intralinguistic and extralinguistic factors, the possibilities of the Uzbek language in the process of expressing the meaning of this vocabulary, as well as the mastery of word usage by one author or another, played a certain role in the formation and development of the semantic scale of the lexeme. The conclusions can be used in enriching the point of view regarding semasiology, in improving the explanatory dictionary of the Uzbek language


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