The Structure and Deposition of the Cuticle in the Adult Mealworm, Tenebrio Molitor L. (Coleoptera)

1948 ◽  
Vol s3-89 (6) ◽  
pp. 197-216
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
The Other ◽  
Secretory Cycle ◽  
Continuous Layer ◽  
Cement Layer ◽  
Dermal Glands ◽  
Basic Layer ◽  
Insoluble Form ◽  
The One ◽  
Pore Canals ◽  
Ammoniacal Silver

The conclusions on the structure of the cuticle in Tenebrio have been summarized on p. 204. Observations on the deposition of the cuticle are in general agreement with those made on Rhodnius. Mitosis and chromatolysis precede the formation of the definitive epidermis. The basic layer of the epicuticle, ‘cuticulin’, is then laid down. It consists of condensed lipoproteins (subsequently tanned, it is supposed, by quinones) and its deposition is immediately preceded by the peak in the secretory cycle of the subepidermal oenocytes. Pore canals from the epidermal cells penetrate the cuticulin layer and pour out silver-reducing material (believed to be dihydroxyphenols in insoluble form) upon its surface. This material is confined to the areas overlying the cell bodies during all but the last stages in its formation, when it fuses to give a more or less continuous layer. During the last few hours before moulting a wax layer appears to be laid down over this polyphenol layer. By the time moulting occurs the polyphenol layer is almost covered and the insect is nearly waterproof. During the first day after moulting, while the secretion of the wax is being completed, the loss of water by transpiration is about four to six times the normal. Very soon after moulting the dermal glands discharge the cement layer over the surface of the wax. The substance of this layer and the contents of the dermal glands reduce ammoniacal silver after extraction with boiling chloroform. It is suggested that it consists of polyphenol-containing material associated with protein and lipides. (It is shown that in Rhodnius the cement layer is formed by the admixture of secretion from the two types of dermal gland previously described. The one produces a solution of protein, the secretion of the other agrees in properties with that here described in Tenebrio. The similarity of this arrangement to that discovered by Pryor in the colleterial glands of the cockroach is pointed out.) In addition to these cement glands there are glands of unknown function opening into the floor of the pits in the cuticle. These are highly developed in the sternites of the male, small and inconspicuous in the female.

Further Studies of the Third Instar Larval Cuticle of Calliphora erythrocephala

1955 ◽  
Vol s3-96 (34) ◽  
pp. 181-191
Author(s):  
L. S. WOLFE
Keyword(s):  
Nitrate Solution ◽  
Silver Nitrate Solution ◽  
Instar Larva ◽  
Secretory Cycle ◽  
Calliphora Erythrocephala ◽  
The Third ◽  
Puparium Formation ◽  
Pore Canals ◽  
Third Instar Larva ◽  
Ammoniacal Silver

The penetration and reduction of ammoniacal silver nitrate solution in the epicuticle of the larva of Calliphora was studied. The epicuticle of the third instar larva is more permeable over the muscle insertions and cuticular sense organs. This finding is related to their development at the previous moult. A surface layer of orientated wax is not present. Proteinaceous and fatty materials from the feeding medium modify the properties of the cuticle surface. Chloroformmethanol extracts a soft light brown acidic lipide from the protein of the epicuticle after contaminants from the medium are removed. The water loss from larvae and puparia of different ages and after various treatments was studied. Young puparia recover from abrasion but larvae do not. An hypothesis that waxy substances are liberated on to the surface of the puparium during hardening and darkening of the cuticle is presented and discussed. The pore canals penetrate the endocuticle until they are cut off from the epidermis by the development of the prepupal cuticle just after the puparial contraction. An inner endocuticle in which pore canals were absent was not found. The structure of the pore canals as shown by phase contrast examination is discussed. The pore canals are three times more concentrated in the lateral regions than in the dorsal or ventral regions. The oenocytes go through a secretory cycle during puparium formation similar to that occurring before moulting of the larva.

scholarly journals The epicuticle in an insect, Rhodnius prolixus (Hemiptera)

1947 ◽  
Vol 134 (875) ◽  
pp. 163-181 ◽  
Keyword(s):  
Rhodnius Prolixus ◽  
Epidermal Cells ◽  
Continuous Film ◽  
Cement Layer ◽  
Dermal Glands ◽  
Pore Canals

The ʻepicuticle’ in Rhodnius consists of four layers. From within outwards these are: (i) the ‘cuticulin layer’ composed, it is suggested, of polymerized lipoproteins tanned by quinones; (ii) the ‘polyphenol layer’ rich in dihydroxyphenols; (iii) the ‘wax layer’ responsible for the waterproofing of the cuticle; (iv) the ‘cement layer’ of unknown nature protecting the wax. The pore canals appear to penetrate the cuticulin layer. The oenocytes produce the lipoproteins which are deposited by the epidermal cells to form the cuticulin layer. The polyphenols then appear at the tips of the pore canals as minute droplets which unite to form a continuous film over the surface of the cuticulin. The wax is then secreted, also by the epidermal cells, and laid down over the polyphenol layer immediately before the old skin is shed. The cement is secreted by the dermal glands and poured out over the surface of the wax within an hour after moulting. The storage and use of the reserves of glycogen, fat and protein during the moulting process are described.

The Deposition of the Third Instar Larval Cuticle of Calliphora erythrocephala

1954 ◽  
Vol s3-95 (29) ◽  
pp. 49-66
Author(s):  
L. S. WOLFE
Keyword(s):  
Secretory Granules ◽  
Histological Study ◽  
Epidermal Cells ◽  
Secretory Cycle ◽  
Calliphora Erythrocephala ◽  
The Third ◽  
Dermal Glands ◽  
Phenolic Substances ◽  
Pore Canals ◽  
Cytoplasmic Processes

A histological study has been made of the formation of the cuticle of the third instar of Calliphora. Increase in size of the epidermal cells and nuclei, particularly in the spiny regions, preceded the release of the moulting fluid. The cytoplasm first became vacuolated and this was followed by the appearance of many granules. The basement membrane is constituted in part by stellate tracheoblast cells. The membrane breaks down just before cuticle deposition and reappears after ecdysis. The outer epicuticle is formed from coalesced droplets aligned at the cell surface to form a delicate continuous, folded, acidophil, lipoprotein layer. Further, protein and lipoid (cuticulin) is added beneath this layer from cytoplasmic processes to form the inner epicuticle. These processes later became the pore canals. Endocuticle is secreted as filaments from the epidermal cells between and around the processes. During moulting, phenolic substances and oxidase are transported to the inner epicuticle only in the cuticular spines. Wax and cement layers are not formed and there are no dermal glands. The peak in the secretory cycle of the oenocytes corresponds to the time of deposition of the epicuticle and the secretory material shows similar staining properties to epicuticular material. The oenocyte groups are connected with each other and with the epidermis by cytoplasmic extensions, through which secretory granules pass. The muscle insertions are not attacked by the moulting fluid. They are thought to contain protein-bound sulphur. The separation of the muscle insertions and sensory organs from the exuvial cuticle occurs just before ecdysis. The nature of the epicuticle and the theory that the oenocytes are associated with its formation is discussed.

The Outer Layers of the Cuticle in the Cockroach Periplaneta americana and the Function of the Oenocytes

1950 ◽  
Vol s3-91 (13) ◽  
pp. 63-72 ◽  
Author(s):  
S. KRAMER ◽  
V. B. WIGGLESWORTH
Keyword(s):  
Honey Bee ◽  
Periplaneta Americana ◽  
Epidermal Cells ◽  
Cuticular Wax ◽  
Cement Layer ◽  
Dermal Glands ◽  
Protein Components ◽  
Egg Shell ◽  
Pore Canals

In the epicuticle of the cockroach there is a cement layer formed, as in other insects, by secretion from certain of the dermal glands at the time of moulting. These dermal glands are widely distributed over the abdominal tergites and sternites in both sexes. Their cell-bodies are atrophied in the mature insect. They differ in this respect from the very numerous dermal glands on the abdominal tergites of the male, which remain distended with vacuoles. The cuticular wax, which is freely exposed on the surface of the cuticle, is thought to be produced by the sub-epidermal oenocytes and to be discharged during the life of the cockroach, perhaps through the pore canals, by the epidermal cells. The oenocytes of the honey-bee are much larger during the height of wax secretion than they are in the foraging bee. The view that the oenocytes are concerned in wax metabolism is compatible with the view that they synthesize the lipoprotein (or wax protein) components of the cuticle and egg-shell.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

The Dermal Glands of Rhodnius Prolixus

1969 ◽  
Vol 27 ◽  
pp. 258-259
Author(s):  
J. E. Lai-Fook
Keyword(s):  
Fine Structure ◽  
Secretory Activity ◽  
Rhodnius Prolixus ◽  
Outermost Layer ◽  
Cement Layer ◽  
Dermal Glands

Dermal glands are epidermal derivatives which are reported to secrete either the cement layer, which is the outermost layer of the epicuticle or some component of the moulting fluid which digests the endocuticle. The secretions do not show well-defined staining reactions and therefore they have not been positively identified. This has contributed to another difficulty, namely, that of determining the time of secretory activity. This description of the fine structure of the developing glands in Rhodnius was undertaken to determine the time of activity, with a view to investigating their function.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Radioimmunotherapy for treatment of acute myeloid leukaemia and myelodysplastic syndrome

2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann
Keyword(s):  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Primary Tumour ◽  
The Other ◽  
Haematopoietic Stem Cell ◽  
Other Hand ◽  
Primary Reduction ◽  
The One ◽  
Acute Myeloid

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.

Das Ende der Postdemokratie, den Pessimismus überwinden.

2017 ◽  
Vol 47 (188) ◽  
pp. 487-494
Author(s):  
Daniel Mullis
Keyword(s):  
Political Thought ◽  
Social Dynamics ◽  
Social Conditions ◽  
The Other ◽  
Economic Decline ◽  
Far Right ◽  
Windows Of Opportunity ◽  
Political Events ◽  
Political Struggles ◽  
The One

In recent years, political and social conditions have changed dramatically. Many analyses help to capture these dynamics. However, they produce political pessimism: on the one hand there is the image of regression and on the other, a direct link is made between socio-economic decline and the rise of the far-right. To counter these aspects, this article argues that current political events are to be understood less as ‘regression’ but rather as a moment of movement and the return of deep political struggles. Referring to Jacques Ranciere’s political thought, the current conditions can be captured as the ‘end of post-democracy’. This approach changes the perspective on current social dynamics in a productive way. It allows for an emphasis on movement and the recognition of the windows of opportunity for emancipatory struggles.

Tolerance is theoretical and practical principles

1996 ◽  
pp. 13-23
Author(s):  
Mykhailo Babiy
Keyword(s):  
Religious Diversity ◽  
The Other ◽  
Nodal Points ◽  
Characteristic Features ◽  
The One ◽  
Ukrainian Society

Political ideological pluralism, religious diversity are characteristic features of modern Ukrainian society. On the one hand, multiculturalism, socio-political, religious differentiation of the latter appear as important characteristics of its democracy, as a practical expression of freedom, on the other - as a factor that led to the deconsocialization of society, gave rise to "nodal points" of tension, confrontational processes, in particular, in political and religious spheres.

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