Organization and Development of the Macronuclear Anlage in Stylonychia Notophora Stokes

1970 ◽  
Vol 6 (2) ◽  
pp. 351-363
Author(s):  
G. R. SAPRA ◽  
C. M. S. DASS
Keyword(s):  
Early Stages ◽  
Break Up ◽  
Pass Through ◽  
Replication Bands ◽  
Two Bodies ◽  
Heavy Labelling

The development of the macronuclear Anlage of Stylonychia notophora was studied by means of cytochemical and autoradiographic techniques. In early stages of its differentiation, the Anlage has its chromatin distributed homogeneously. Nine to ten hours later chromosomes are noticed; the nucleus is possibly diploid. Following this, the number of chromosomes increases progressively resulting in polyploidy. Later, chromosomes uncoil and polytenization follows. After consolidation and shrinkage of these chromosomes, the Anlage splits into two bodies. Five series of replication bands quickly pass through each and the vegetative macronucleus results. Synthesis of RNA by the new macronucleus starts soon after the shrinkage stage. The old macronuclei break up into small spherical bodies which are gradually resorbed in the cytoplasm. When [3H]thymidine is provided continuously to the exconjugants, there is little uptake into the Anlage until the old macronucleus is completely resorbed. Only after this, heavy labelling is noticed. Fate of the previously labelled macronuclei during conjugation shows that their breakdown products are re-utilized for the development of the new macronucleus.

Interaction of solid bodies with atmospheres of protoplanets

2018 ◽  
Vol 14 (S345) ◽  
pp. 351-352
Author(s):  
Ernst A. Dorfi ◽  
Florian Ragossnig
Keyword(s):  
Kinetic Energy ◽  
Physical Properties ◽  
Planet Formation ◽  
Frictional Heating ◽  
Protoplanetary Disk ◽  
Small Bodies ◽  
Early Stages ◽  
Break Up ◽  
Solid Bodies ◽  
Stellar Source

AbstractDuring the early stages of planet formation accretion of small bodies add mass to the planet and deposit their energy kinetic energy. Caused by frictional heating and/or large stagnation pressures within the dense and extended atmospheres most of the in-falling bodies get destroyed by melting or break-up before they impact on the planet’s surface. The energy is added to the atmospheric layers rather than heating the planet directly. These processes can significantly alter the physical properties of protoplanets before they are exposed with their primordial atmospheres to the early stellar source when the protoplanetary disk becomes evaporated.

Research of Self-Oscillating Processes in the Zone of Interaction of an Elastic Tire with a Solid Support Base

2021 ◽  
pp. 3-15
Author(s):  
M.M. Zhileykin
Keyword(s):  
Rear Axle ◽  
Solid Support ◽  
Diagnostic Feature ◽  
Early Stages ◽  
Wheeled Vehicles ◽  
Oscillating Processes ◽  
Two Bodies ◽  
Oscillating Mode

When two bodies interact in contact, self-oscillations or relaxation vibrations can occur, which are vibrations of parts of bodies relative to each other. The study of the processes occurring in the zone of an elastic tire interaction with a solid support base is of particular interest, since they directly affect the safety of movement of wheeled vehicles. The aim of the work is to study the conditions for the occurrence of self-oscillating processes in the zone of interaction of an elastic tire with a solid support base in three rolling modes: traction, driven, and braking. It has been established that the appearance of a self-oscillating mode in the zone of interaction of an elastic tire with a solid support base is a useful diagnostic feature providing recognition of the development of the process of losing adhesion of a wheel with a support base when the rear axle skids at early stages.

The Role of the Input in the Acquisition of Third Person Singular Verbs in English

2003 ◽  
Vol 46 (4) ◽  
pp. 863-877 ◽  
Author(s):  
Anna L. Theakston ◽  
Elena V. M. Lieven ◽  
Michael Tomasello
Keyword(s):  
Language Acquisition ◽  
Language Use ◽  
Alternative Explanation ◽  
Early Stages ◽  
Grammatical Subject ◽  
Stage Of Development ◽  
Verb Forms ◽  
Third Person ◽  
Pass Through

During the early stages of language acquisition, children pass through a stage of development when they produce both finite and nonfinite verb forms in finite contexts (e.g., "it go there," "it goes there"). Theorists who assume that children operate with an abstract understanding of tense and agreement marking from the beginnings of language use tend to explain this phenomenon in terms of either performance limitations in production (e.g., V. Valian, 1991) or the optional use of finite forms in finite contexts due to a lack of knowledge that tense and agreement marking is obligatory (the optional infinitive hypothesis; K. Wexler, 1994, 1996). An alternative explanation, however, is that children's use of nonfinite forms is based on the presence of questions in the input ("Where does it go¿") where the grammatical subject is immediately followed by a nonfinite verb form. To compare these explanations, 2 groups of 24 children aged between 2 years 6 months and 3 years were exposed to 6 known and 3 novel verbs produced in either declaratives or questions or in both declaratives and questions. The children were then questioned to elicit use of the verbs in either finite or nonfinite contexts. The results show that for novel verbs, the children's patterns of verb use were closely related to the patterns of verb use modeled in the language to which they were exposed. For known verbs, there were no differences in the children's use of individual verbs, regardless of the specific patterns of verb use modeled in the language they heard. The implications of these findings for theories of early verb use are discussed.

scholarly journals VIII. Researches on the impregnation of the ovum in the amphibia; and on the early stages of development of the embryo. ( third series.)

1854 ◽  
Vol 144 ◽  
pp. 229-244 ◽  
Keyword(s):  
Vitelline Membrane ◽  
Stages Of Development ◽  
Early Stages ◽  
Pass Through

In a note dated April 18th, 1853, which was added to my last paper on the “ Impregnation of the Ovum'',” whilst it was printing, I recorded the fact that, “ through the adoption of a different mode of examination” from that which I had previously employed, I had seen the spermatozoon pass through the gelatinous covering and the vitelline membrane of the egg into the vitelline chamber and the yelk.

scholarly journals On the life-cycle of Spirochaetagallinarum

Parasitology ◽  
1911 ◽  
Vol 4 (4) ◽  
pp. 463-477 ◽  
Author(s):  
E. Hindle
Keyword(s):  
Life Cycle ◽  
Malpighian Tubules ◽  
Coelomic Fluid ◽  
Open Wound ◽  
Infected Tick ◽  
Argas Persicus ◽  
Transverse Division ◽  
Break Up ◽  
Pass Through ◽  
Peculiar Mode

The life-cycle of S. gallinarum may be briefly summarised as follows:Commencing with the ordinary parasite in the blood of the fowl, the spirochaete grows until it reaches a certain length (16 μ–19 μ) and then divides by the peculiar mode of transverse division described above. This process is repeated and is probably the only method of multiplication of the parasite within the blood. When the spirochaetes disappear from the circulation some of them break up into coccoid bodies which, however, do not usually redevelop in the fowl. When the spirochaetes are ingested by Argas persicus, some of them pass through the gut wall into the coelomic fluid. From this medium they bore their way into the cells of the various organs of the tick and there break up into a number of coccoid bodies. These intracellular forms multiply by ordinary fission in the cells of the Malpighian tubules and gonads. Some of the coccoid bodies are formed in the lumen of the gut and Malpighian tubules. The result is that some of the coccoid bodies may be present in the Malpighian secretion and excrement of an infected tick and when mixed with the coxal fluid may gain entry into another fowl by the open wound caused by the tick's bite. They then elongate and redevelop into ordinary spirochaetes in the blood of the fowl, and the cycle may be repeated.

scholarly journals A Geometrical Proof of Professor Morley's Extension of Feuerbach's Theorem

1919 ◽  
Vol 38 ◽  
pp. 2-5
Author(s):  
Herbert W. Richmond
Keyword(s):  
The Other ◽  
National Academy Of Sciences ◽  
Geometrical Proof ◽  
Special Cases ◽  
The Common ◽  
Break Up ◽  
Pass Through ◽  
Academy Of Sciences ◽  
Circular Points

In the Proceedings of the National Academy of Sciences of the U.S.A., Vol. II. (1916), page 171, Professor F. Morley has established a theorem which both extends and simplifies the theorem of Feuerbach, viz., All curves of class three which (i) touch the six lines OP, OQ, OR, QR, RP, PQ joining four orthocentric points, O, P, Q, R, and (ii) pass through the circular points, also touch the common nine-points-circle of the triangles PQR, OQR, ORP, OPQ. Sixteen of these curves of class three break up into one of the four points aud a circle touching the sides of the triangle formed by the other three. Thus the sixteen instances of Feuerbach's theorem derivable from the four triangles are included as special cases, in Morley's theorem. A purely geometrical proof of the theorem may be worth consideration.

scholarly journals Physiological Sexual Body, Emotional Body and Sexuality

2016 ◽  
Vol 9 (1) ◽  
pp. 41-41
Author(s):  
T. Strepetova ◽  
◽  
D. Trotta ◽  
L. Otranto ◽  
F. Gorga ◽  
...  
Keyword(s):  
External World ◽  
Clinical Applications ◽  
Complex Interaction ◽  
The Body ◽  
The Other ◽  
Sexual Distress ◽  
Pass Through ◽  
The Individual ◽  
Two Bodies ◽  
Sexual Body

Objective: Our body is at the same time a biological and a sexological body. Biological body is innate and based on our genes and their capacity to express and realize their potentials. Our sexual body is acquisite and is related to our education and learning and our capacity to decode and read the external world. Our sexological body is a lot more than our biological body. Our aim is to differentiate the two bodies and the better understand and handle sexual misunderstanding and sexual difficulties. Design and Method: Sexuality as acted and performed is the resulting and final step of a complex interaction of different forces. By means of the observation of the physical and sexual body and its position in the space, its rhythms and its tonicity it is possible to relate to the emotions that live inside and pass through the human being. And, on the contrary, acting on the body, modifying its posture and its movements is possible to influence sexual sensations and feelings. Results: Observing and acting on the physical body is useful in influencing and positively modifying the individual sexual emotional and psychological mind, and to lessen sexual distress or to resolve sexual impairment. Conclusions: Biological and emotional body are tightly related. The observation and the analysis of one body reflect the other as well as the intervention on one of the two bodies can influence and transform the other one. This can lead to important results and clinical applications.

scholarly journals Heat flowing from cold to hot without external intervention by using a “thermal inductor”

2019 ◽  
Vol 5 (4) ◽  
pp. eaat9953 ◽  
Author(s):  
A. Schilling ◽  
X. Zhang ◽  
O. Bossen
Keyword(s):  
Ambient Temperature ◽  
Second Law Of Thermodynamics ◽  
Thermal Bath ◽  
Quasi Equilibrium ◽  
External Energy ◽  
Peltier Element ◽  
Pass Through ◽  
External Intervention ◽  
Two Bodies ◽  
External Driving

The cooling of boiling water all the way down to freezing, by thermally connecting it to a thermal bath held at ambient temperature without external intervention, would be quite unexpected. We describe the equivalent of a “thermal inductor,” composed of a Peltier element and an electric inductance, which can drive the temperature difference between two bodies to change sign by imposing inertia on the heat flowing between them, and enable continuing heat transfer from the chilling body to its warmer counterpart without the need of an external driving force. We demonstrate its operation in an experiment and show that the process can pass through a series of quasi-equilibrium states while fully complying with the second law of thermodynamics. This thermal inductor extends the analogy between electrical and thermal circuits and could serve, with further progress in thermoelectric materials, to cool hot materials well below ambient temperature without external energy supplies or moving parts.

Fates and migratory routes of primitive streak cells in the chick embryo

Development ◽  
1996 ◽  
Vol 122 (5) ◽  
pp. 1523-1534 ◽  
Author(s):  
D. Psychoyos ◽  
C.D. Stern
Keyword(s):  
Chick Embryo ◽  
Primitive Streak ◽  
Final Position ◽  
Fate Map ◽  
Early Chick Embryo ◽  
Carbocyanine Dyes ◽  
Early Stages ◽  
Migratory Routes ◽  
Pass Through ◽  
Different Tissues

We have used carbocyanine dyes to fate map the primitive streak in the early chick embryo, from stages 3+ (mid-primitive streak) to 9 (8 somites). We show that presumptive notochord, foregut and medial somite do not originate solely from Hensen's node, but also from the anterior primitive streak. At early stages (4- and 4), there is no correlation between specific anteroposterior levels of the primitive streak and the final position of their descendants in the notochord. We describe in detail the contribution of specific levels of the primitive streak to the medial and lateral halves of the somites. To understand how the descendants of labelled cells reach their destinations in different tissues, we have followed the movement of labelled cells during their emigration from the primitive streak in living embryos, and find that cells destined to different structures follow defined pathways of movement, even if they arise from similar positions in the streak. Somite and notochord precursors migrate anteriorly within the streak and pass through different portions of the node; this provides an explanation for the segregation of notochord and somite territories in the node.

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