The incubatory chamber of marsupial carditids (Bivalvia: Carditidae: Thecaliinae) as an exaptation

Paleobiology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Damián Eduardo Pérez ◽  
Ignacio María Soto
Keyword(s):  
Precise Definition ◽  
The Other ◽  
Present Evidence ◽  
Phylogenetic Studies ◽  
Evolutionary Pathways ◽  
Alternative Scenarios ◽  
Evolutionary Narratives ◽  
Definition Of

Abstract Marsupial carditids of the subfamily Thecaliinae are characterized by the presence of an “incubatory chamber” in female shells, where the eggs hatch and develop during their first stages. According to recent phylogenetic studies, Thecaliinae are closely related to Carditinae, a group that has a byssal gape. This structure occurs in the same area as the incubatory chamber, and both structures could be evolutionarily related. Using the newest phylogenetic context for the subfamilies, we test whether the incubatory chamber of Thecaliinae is related to characters present in Carditinae. We also provided a more precise definition of the implied structures. Two distinct morphologies for the incubatory chamber are described: one with an exteriorly opened pouch (present in the genera Powellina and Milneria) and the other with a completely internal funicular infold (present in Thecalia). The byssal gape is present in the Cardiobyssata clade (Carditamerinae + (Carditinae + Thecaliinae)), and we discuss whether the incubatory chamber could be the result of an exaptation event, and the possible evolutionary pathways implied. According to the present evidence, we propose a co-optation of the byssal gape into a new function (brooding of larvae) at some point during the transition from the Carditinae to the Thecaliinae lineages, thus determining an exaptation. Adaptative processes probably modified this structure into the incubatory chamber (an external pouch first, and a funicular infold later). We discuss alternative scenarios and implications on phylogenetic studies and the importance of considering non-adaptative evolutionary scenarios in the study of evolutionary narratives.

Pozycja ustrojowa parlamentu finlandzkiego Eduskunty

2019 ◽  
Vol 1 ◽  
pp. 145-162
Author(s):  
Viktoria Serzhanova
Keyword(s):  
Internal Structure ◽  
Structure Functions ◽  
Precise Definition ◽  
The Other ◽  
Basic Law ◽  
Form Of Government ◽  
Rules Of Procedure ◽  
The Subject ◽  
The Moment ◽  
Definition Of

The hereby paper takes up the analysis of the constitutional position of the Finnish parliament Eduskunta from the moment of its establishment and as a result of its development during the centuries, with a special attention paid to the present normative state and on the basis of the hitherto constitutional practice. It aims at deriving the origin and presenting the evolution of this authority at the Finnish lands, which in consequence leads to reliable conclusions in the scope of determining its current constitutional position in the system of the supreme state authorities of Finland. The subject of the paper focuses on the analysis of the beginnings of Eduskunta’s formation and Finnish parliamentarianism, its further evolution, current composition, internal structure, functions and competences presented on the basis of the exegesis of the provisions of the binding basic law of 1999 and the parliament’s rules of procedure. The constitutional principles referring to the parliament and the analysis of Eduskunta’s relations with the other supreme state authorities, which determine the state’s form of government, seem to be of particular significance in this context, as they contribute to a more precise definition of Eduskunta’s constitutional position, as well as to pointing out its originality and dissimilarity regarding other contemporary democratic states.

Drøftelse af flygtningebegrebets definition

1979 ◽  
Vol 48 (1-4) ◽  
pp. 139-141
Keyword(s):  
International Law ◽  
Nordic Countries ◽  
Precise Definition ◽  
The Other ◽  
General Definition ◽  
Refugee Status ◽  
Strict Adherence ◽  
High Commissioner ◽  
Definition Of ◽  
Legal Concepts

AbstractThe main subject of the debate was whether or not it is advisable to extend the concept of refugee beyond the present strict legal definitions and include more humanitarian concerns as suggested by Poul Hartling. On the one hand it was maintained in alia that — an extension of the international concept would create a discrepancy between the national concepts and the international concept — the concept of refugee applicable at the time of passing legislation concerning refugees still pertains — the quota-systems require strict adherence to legal definitions — the unsuccessful conference on territorial asylum proved the difficulty of adopting common norms of a broad humanitarian nature wrich is at the same time acceptable to governments - it was easier for the UNHCR in his pragmatic international work of a humanitarian administrative and social nature to adopt a wide concept, whereas the national refugee agencies whose problems is primarily that of issuing residence permits have to apply a more precise and narrow definition. Others took the view that — even in international law the concept of refugee is not totally static; in this respect it was mentioned that in spite of unmerous laws on refugees in Sweden, a precise definition has never been found - a liberal interpretation of existing written norms was called for rather than attempts to establish totally new definitions in a legally binding form - humanitarian concerns are not opposed to legal concepts; on the contrary, the legal concepts emerge from humanitarian and other political concerns — the definition in international law is to be considered a minimum norm. It was suggested that the refugee concept could be much wider in the field of assistance rather than in the field of protection. The dichotomy of having two refugee concepts, an international and a national come out as a practical problem when it comes to recognizing the refugee status. Theoretically, the dichotomy does not create serious problems, because the recognition is declaratory, not constitutive. In practical terms, there is a problem, however, because there is only one (effective) recognition of refugee status, the national recognition. It was noted that the High Commissioner often responded spontaneously to emergency situations involving wholely or in part groups of people falling beyond or on the verge of his mandate. The UN General Assembly, however, never failed to welcome such action thereby accepting a wider definition of UNCHR's mandate. The problems of de facto refugees were discussed. Reluctance was expressed towards extending the number of categories of refugees, e.g. by adding C and D categories to the A and B categories existing in the Nordic countries. It was preferable to extend the general definition of refugee in the manner of e.g. the Netherlands, Switzerland, or Sweden. A consequence of recognizing de facto refugees explicitly one way or the other was that the concept of de facto refugee would disappear. A common international definition which includes de facto refugees was called for. On the other hand, a warning was issued against adopting a very precise definition thereby creating new limits and new categories of people needing humanitarian assistance or protection but falling outside accepted categories. The problem of lacking international sanctions against countries which do not apply the international minimum standards was mentioned. It was pointed out, however, that the good offices and diplomatic initiatives of the High Commissioner often proved highly effective. Finally, a number of participants invited the High Commissioner to engage deeper into regional arrangements and to open a regional office in the Nordic countries.

scholarly journals The Unmarriageables: Why the Name is Essential to Denote the Scheduled Castes?

2020 ◽  
Vol 7 (1) ◽  
pp. 1927
Author(s):  
Karl M. Siddharthar
Keyword(s):  
Social Justice ◽  
Caste System ◽  
Precise Definition ◽  
The Other ◽  
Whistle Blowing ◽  
Doctoral Thesis ◽  
Scheduled Castes ◽  
Definition Of ◽  
The Masses

What the Book is about? To dispel all the needless interpretations and confusions about the Caste and to compel all the Scholars, Academicians, Legislators, Politicians and even the Masses not to deviate themselves from the precise definition of Caste in the matters of Annihilation of Caste, Emancipation of Depressed Classes, Reservation etc. is what this Book aims to achieve. The concept of 'Unmarriageability' and the nomenclature of 'Unmarriageables' introduced in this Book is merely an extended reinterpretation of Dr.Ambedkar's finding in his Doctoral Thesis that Caste is nothing but the Mechanism of Endogamy. Hence, it became inevitable that the first chapter introduce the readers to the writings and speeches of Dr.Ambedkar for the better understanding about Caste and Untouchability- the premises based on which the entire Book is constructed. Proceeding from here, the rest of the chapters are in fact series of arguments built one over the other to expose the existence of stigma of Unmarriageability, its significance in sustaining Caste and the need to annihilate it in order to annihilate Caste. Whistle blowing the stigma of Unmarriageability is intended to dismantle the foundation of Caste system and also is a strategic spearhead to question the general conscience of this society and simultaneously safeguarding the principles of Social Justice, the aspects of which is dealt in the last two chapters.

On the functions of swearing in Persian

2016 ◽  
Vol 4 (2) ◽  
pp. 234-254 ◽  
Author(s):  
Mohammad Ali Salmani Nodoushan
Keyword(s):  
Precise Definition ◽  
The Other ◽  
Deontological Ethics ◽  
Definition Of

The burgeoning literature on studies of swearing suggests that any acceptable definition of swearing involves three features: (a) non-literal meanings, (b) taboo subjects, and (c) emotions. It also suggests that swearwords fall into one of the three classes: aggressive, cathartic, or social. Driven by a rich corpus of swearwords from Persian, this paper argues that swearing in Persian does not necessarily involve these three features, and that a redefinition of swearing is needed. It then borrows ideas from ethics to suggest that any precise definition of swearing will have to involve the distinction between teleological and deontological ethics. It further envisages a continuum for swearing, with teleological ethics at one end and deontological ethics at the other, on which different forms of swearing can be arranged based on the degree to which they lean towards either end.

Phylogeny of parasitic Platyhelminthes: a critical study of synapomorphies proposed on the basis of the ultrastructure of spermiogenesis and spermatozoa

1991 ◽  
Vol 69 (6) ◽  
pp. 1421-1440 ◽  
Author(s):  
Jean-Lou Justine
Keyword(s):  
Precise Definition ◽  
The Other ◽  
Critical Study ◽  
Nuclear Region ◽  
Spiral Pattern ◽  
Parasitic Species ◽  
Dense Granules ◽  
Sperm Characteristics ◽  
Paraphyletic Group ◽  
Definition Of

Recent cladistic phylogenies of the Platyhelminthes, especially the parasitic species, use for synapomorphies several characters of the spermatozoa, together with other characters. This paper reinvestigates synapomorphies based on sperm characteristics. The outgroup usually chosen for such studies on the parasitic Platyhelminthes (Cercomeria) is the "Dalyelliida" or "Dalyellioida," generally considered a paraphyletic group, but sperm structure in this group shows great variation. In this paper, the Typhloplanoida, which have a plesiomorphic structure (two free axonemes), are considered the outgroup. One of the synapomorphies recently proposed for the Neodermata is "spermatozoon with axonemes incorporated in the cytoplasm." This definition introduces convergences with several other groups of nonparasitic Platyhelminthes. A more precise definition of spermiogenesis, based on a detailed description, is proposed in this paper and avoids homoplasies: "proximodistal fusion of the axonemes." This implies the presence of dorsal and ventral microtubules in the nuclear region of the spermatozoon. This synapomorphy characterizes the Cercomeridea but not the Neodermata (= Udonellidea + Cercomeridea). The character "absence of dense granules in the spermatozoon" should be considered a synapomorphy for the Neodermata and has almost no homoplasies. For the Temnocephalidea, the spiral pattern of the peripheral microtubule row is proposed as a synapomorphy. This character is present in Didymorchis; however, Didymorchis lacks tentacles, which are present in the other genera, and thus the ultrastructural synapomorphy is in conflict with a recently proposed morphological synapomorphy for this group: the presence of tentacles. No synapomorphy of the spermatozoon can be proposed for the Monogenea, but the presence of lateral microtubules lining the axonemes is proposed as a synapomorphy for the polyopisthocotylean Monogenea, and the absence of dorsal and lateral microtubules is proposed as a synapomorphy for the monopisthocotylean Monogenea (this is a reversal of the synapomorphy for the Cercomeridea defined above). The cyclophyllidean Eucestoda show a twisting of the peripheral microtubules of the spermatozoon, which is proposed as a synapomorphy.

scholarly journals Il recupero del sé attraverso l'autobiografia

2005 ◽  
Author(s):  
Leonardo Trisciuzzi ◽  
Barbara Sandrucci ◽  
Tamara Zappaterra
Keyword(s):  
Mental Activity ◽  
The State ◽  
Precise Definition ◽  
The Other ◽  
Definition Of ◽  
Over Time

The request for a precise definition of memory would put any serious academic into difficulty. To provide a synthetic response, we could define memory as a marvellous mechanism, a means for taking us back in time. Memory is, therefore, a mental activity which connects us over time and gives a meaning to existence. Telling one's story, one's autobiography, signifies primarily taking stock of the state of one's own identity; it signifies communication, communicating who we are to ourselves and others. It means transforming the interior monologue into dialogue with the other; it means scanning and modulating our emotions through the representation of the events of our lives.

scholarly journals A Precise Definition of an Inference (by the Example of Natural Deduction Systems for Logics $I_{\langle \alpha,\beta \rangle}$

2017 ◽  
Vol 23 (1) ◽  
pp. 83-104 ◽  
Author(s):  
В.О. Шангин
Keyword(s):  
Classical Logic ◽  
Natural Deduction ◽  
Precise Definition ◽  
The Other ◽  
Deduction System ◽  
Introduction Rule ◽  
Special Cases ◽  
Natural Deduction System ◽  
Alpha Beta ◽  
Definition Of

In the paper, we reconsider a precise definition of a natural deduction inference given by V. Smirnov. In refining the definition, we argue that all the other indirect rules of inference in a system can be considered as special cases of the implication introduction rule in a sense that if one of those rules can be applied then the implication introduction rule can be applied, either, but not vice versa. As an example, we use logics $I_{\langle\alpha, \beta\rangle}, \alpha, \beta \in \{0, 1, 2, 3,\dots \omega\}$, such that $I_{\langle 0, 0\rangle}$is propositional classical logic, presented by V. Popov. He uses these logics, in particular, a Hilbert-style calculus $HI_{\langle\alpha, \beta\rangle}, \alpha, \beta \in \{0, 1, 2, 3,\dots \omega\}$, for each logic in question, in order to construct examples of effects of Glivenko theorem’s generalization. Here we, first, propose a subordinated natural deduction system $NI_{\langle\alpha, \beta\rangle}, \alpha, \beta \in \{0, 1, 2, 3,\dots \omega\}$, for each logic in question, with a precise definition of a $NI_{\langle\alpha, \beta\rangle}$-inference. Moreover, we, comparatively, analyze precise and traditional definitions. Second, we prove that, for each $\alpha, \beta \in \{0, 1, 2, 3,\dots \omega\}$, a Hilbert-style calculus $HI_{\langle\alpha, \beta\rangle}$and a natural deduction system $NI_{\langle\alpha, \beta\rangle}$are equipollent, that is, a formula $A$ is provable in $HI_{\langle\alpha, \beta\rangle}$iff $A$ is provable in $NI_{\langle\alpha, \beta\rangle}$. DOI: 10.21146/2074-1472-2017-23-1-83-104

scholarly journals High-order metaphysics as high-order abstractions and choice in set theory

2020 ◽  
Author(s):  
Vasil Dinev Penchev
Keyword(s):  
Set Theory ◽  
Axiom Of Choice ◽  
High Order ◽  
Precise Definition ◽  
The Other ◽  
Axiom Scheme ◽  
The One ◽  
Definition Of ◽  
The Axiom Of Choice ◽  
Comprehension Axiom

The link between the high-order metaphysics and abstractions, on the one hand, and choice in the foundation of set theory, on the other hand, can distinguish unambiguously the “good” principles of abstraction from the “bad” ones and thus resolve the “bad company problem” as to set theory. Thus it implies correspondingly a more precise definition of the relation between the axiom of choice and “all company” of axioms in set theory concerning directly or indirectly abstraction: the principle of abstraction, axiom of comprehension, axiom scheme of specification, axiom scheme of separation, subset axiom scheme, axiom scheme of replacement, axiom of unrestricted comprehension, axiom of extensionality, etc.

Radar Usage and Speed in Fog

1951 ◽  
Vol 4 (02) ◽  
pp. 149-155
Author(s):  
E. M. Robb
Keyword(s):  
Precise Definition ◽  
The Other ◽  
The Road ◽  
Other Hand ◽  
Full Discussion ◽  
Definition Of ◽  
Made In

The use of radar in relation to the Rule of the Road at sea is a subject over which there is still a great deal of controversy. An examination of the main problems involved was made in this Journal (Vol. 3, No. 1, January 1950) by Captain F. J. Wylie who concluded in his paper that the use of radar might justify a more liberal interpretation of the term ‘moderate speed’ than has hitherto been countenanced; and a recent amendment to theKing's Regulations and Admiralty Instructionsclearly accepts the use of radar as an existing circumstance within the meaning of Article 16.No attempt, however, has so far been made to arrive at a precise definition of ‘moderate speed’, and it may well be that the reasons which prevented a definition being made in the non-radar case are in fact given more force when radar, with its added variables, is used. On the other hand it is unlikely that any progress in the matter can be made without a full discussion of the factors involved, and Captain Robb's paper, though it may be possible to dispute some of his conclusions, is presented here as an interesting attempt to achieve a definition which can serve as a guide to shipmasters.—Ed.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Sign in / Sign up

Export Citation Format

Share Document