Microsurgically generated discontinuities provoke heritable changes in cellular handedness of a ciliate, Stylonychia mytilus

Development ◽  
1991 ◽  
Vol 111 (2) ◽  
pp. 337-356
Author(s):  
X.B. Shi ◽  
Z.I. Qiu ◽  
W. He ◽  
J. Frankel
Keyword(s):  
Large Scale ◽  
Mirror Image ◽  
The Other ◽  
Left Edge ◽  
Left Handed ◽  
Specific Manner ◽  
The Right ◽  
Anteroposterior Polarity ◽  
Posterior Anterior ◽  
Stylonychia Mytilus

Stylonychia mytilus is a dorsoventrally flattened ciliate with compound ciliary structures arranged in a specific manner on the cell surface. In mirror-image (MI) doublets of this ciliate, two nearly complete sets of ciliary structures are arrayed side-by-side, one in a normal or ‘right-handed’ (RH) arrangement, the other in a reversed or ‘left-handed’ (LH) arrangement. MI-doublets exist in two forms, one with the RH component on the right, the LH component on the left, and feeding structures near the center (‘buccal-adjoining MI-doublet’); the other with the RH component on the left, the LH component on the right, and feeding structures on the lateral edges (‘buccal-opposing MI-doublet’). We describe an operation that can generate either type of MI-doublet. This operation interchanges large anterior and posterior regions of the cell, transposing the original posterior region anteriorly (P—A) and the original anterior region posteriorly (A—P), while retaining the original anteroposterior polarity of each region. Two sets of new ciliary structures then are formed in mirror-image arrangement, with the set in the P—A region oriented normally and the set in the A—P region undergoing a reversal of polarity along its anteroposterior axis. This sometimes creates end-to-end MI forms, but more commonly produces side-by-side MI-doublets through a folding together of the P—A and A—P regions. This folding occurs because one lateral edge of the cell had been removed during the operation; if the left edge was removed, the complex folds to the left and forms a buccal-adjoining MI-doublet, whereas if the right edge was removed, the complex folds to the right and forms a buccal-opposing MI-doublet. Both types can reorganize and later divide true-to-type, although the ‘buccal-opposing’ type is by far the more stable of the two. The generation of mirror-image forms is dependent on the prior abnormal juxtaposition of regions from opposite ends of the cell, and involves a coordinated respecification of large-scale organization. We interpret this response to be a consequence of intercalation of missing intervening positional values in the zone of posterior-anterior abutment.

Lateral Onset Asynchrony in Left-Handers

1976 ◽  
Vol 43 (1) ◽  
pp. 255-259 ◽  
Author(s):  
Takeshi Hatta
Keyword(s):  
Visual Field ◽  
Standard Stimulus ◽  
The Other ◽  
Right Visual Field ◽  
Left Handed ◽  
The Right ◽  
Onset Asynchrony

Study of matching judgment was designed to demonstrate an effect of lateral onset asynchrony in left-handed subjects, 7 males and 8 females. Japanese Hirakana letters or random forms were presented to one visual field first and to the other visual field second. 15 left-handers were requested to judge whether the successively presented stimuli were “same” or “different.” The results showed that for both types of stimuli there are no differences in accuracy of matching judgment whether the standard stimulus was presented to the right visual field first or to the left. These results indicate that the left-handed subjects may have a tendency toward hemispheric equi-potentiality for recognition of both verbal and non-verbal materials.

A Note on Five Inscriptions in Swansea

1971 ◽  
Vol 39 ◽  
pp. 47-51
Author(s):  
Roger Ling
Keyword(s):  
Eighteenth Century ◽  
The Other ◽  
White Marble ◽  
Left Edge ◽  
South Wales ◽  
Royal Institution ◽  
The Right ◽  
Half Thickness

The following five inscriptions, three of which were noted in Rome in the eighteenth century, while the other two are unpublished, have found their way to the Royal Institution of South Wales at Swansea.1. Plate X, a. White marble plaque, sub-rectangular in form, but with top right corner broken away (33·5 × 29·0 × 3·25). Top and bottom edges smooth; sides very roughly cut; back flat and smooth over much of surface, but chipped away to nearly half thickness at top, and a smooth ledge cut along bottom. Dowel holes drilled at two points in step created by latter (shallower hole at one side looks modern, deeper hole at middle looks ancient) and at centre of left edge. Some scratches at back, especially along top ledge and at bottom right corner, also look modern.Letters: 1. 1, 2.7; 1. 2, 2.3; 11. 3–5, 2.0; 11. 6–7, 1.7; 1. 8, 2.2. Ligature of Ӕ at end of 1.3. Stops generally triangles of various sizes, pointing down and a little to the right, but sometimes comma-like; in all the usual places, as well as at end of lines 2, 4, 6, 7.

PECULIARITY OF THE LEGAL RELATIONSHIP OF ENVIRONMENTAL LAW

2021 ◽  
pp. 88-97
Author(s):  
Andrian Cretu ◽  
◽  
◽  
Keyword(s):  
Natural Resources ◽  
Large Scale ◽  
Raw Materials ◽  
Environmental Law ◽  
The Other ◽  
Unintended Effects ◽  
Legal Relationship ◽  
Intensive Exploitation ◽  
The Right ◽  
Relationship Of

The possibilities of man to turn natural resources into sources of profit have led the legislator and the right, in general, to resort to much tougher regulations in the field of environmental protection, this could not be possible without knowing precisely the nature of the legal relationship that would lay the basis for subsequent regulations, and in the doctrinal plan it and today suffers from numerous criticisms, debates and controversies. However, one thing is for certain, the relationship of the environment is one of the particular, double-side, where, on the one hand, it regulates the relations between people are established on the occasion of the use, protection, conservation and development, environmental factors, and by the other hand, it requires the modeling of the principles of the other areas of the law with which they come in contact with, and this is asked for a better connectivity and efficiency in the plan for the defense of the values of the environment, the most valuable in the world is on the verge of collapse, natural. In this sense, the realities of today show that the twentieth century is the time of the greatest discoveries and transformations of civilization, but also the most complex and sometimes unintended effects on life. Not long ago, renewable natural resources of the Earth, would be sufficient for the needs of humanity, but for now, as a result of the population explosion, and the unprecedented development of all areas of the business, the demand for raw materials and energy for the production of goods has increased greatly, and the intensive exploitation of natural resources show more obviously, an ecological imbalance. In the context of large-scale changes that can jeopardize the quality of the environment, it is necessary to consider the intentions underlying the exploitation of environmental resources, emerging from the alarming situation that can no longer be tolerated, risking the survival and existence of the human species.

Synchronization Error in Bilateral Simultaneous Flexion of Elbows

1975 ◽  
Vol 40 (2) ◽  
pp. 527-532 ◽  
Author(s):  
R. Nakamura ◽  
R. Taniguchi ◽  
Y. Oshima
Keyword(s):  
Warning Signal ◽  
Mirror Image ◽  
Sound Stimulus ◽  
Synchronization Error ◽  
Experimental Conditions ◽  
Synchronization Errors ◽  
Left Handed ◽  
Left And Right ◽  
The Difference ◽  
The Right

Using 7 left- and 7 right-handed subjects, the difference in time between left and right arms in the initiation of bilateral simultaneous flexion of elbows (synchronization error) was measured under three conditions: response to a sound stimulus with a warning signal, response to a sound stimulus without a warning signal, and self-initiated trial (option). The absolute value of synchronization errors depended upon experimental conditions. In conditions ‘with warning’ and ‘option’ the dominance shown in performance of left-handed subjects was the mirror-image of that shown by the right-handed subjects. The right biceps muscle responded faster in left-handed subjects and vice versa. Right-handed subjects showed rather a constant value in their dispersion of synchronization errors.

scholarly journals Leer je kinderen minder te tolereren! Teach your children to tolerate less!

Pedagogiek ◽  
2021 ◽  
Vol 41 (3) ◽  
Author(s):  
Anders Schinkel
Keyword(s):  
Large Scale ◽  
Critical Reflection ◽  
The Other ◽  
Content Type ◽  
Other Hand ◽  
The One ◽  
The Right

Abstract Toleration is a person’s response, on the one hand, to something she disapproves of, and on the other hand, to her inclination to put a stop to that which she disapproves of. When people think about toleration from a pedagogical perspective, as a virtue to be cultivated, attention naturally focuses on the latter: how do we teach someone to control herself, to take the other’s perspective, et cetera; and how do we make sure someone develops ‘tolerant’ views? Discussions about this virtually always concern the same topics, however; critical reflection on the objects of (in)tolerance are lacking. When we turn our gaze outwards, we see that intolerable practices take place on a large scale (e.g. ecologically destructive practices) that we all ‘tolerate’ – because we don’t care enough. We ought to teach children to care about the right things to the right degree; and that means we need to teach them not to tolerate certain practices.

scholarly journals Neutrino masses in a supersymmetric model with exotic right-handed neutrinos in global 𝒵3 ⊗ (B − L) symmetry

2021 ◽  
Vol 36 (02) ◽  
pp. 2150010
Author(s):  
M. C. rodriguez
Keyword(s):  
Experimental Data ◽  
The Other ◽  
Tree Level ◽  
Supersymmetric Model ◽  
Neutrino Masses ◽  
Seesaw Mechanism ◽  
Mixing Angle ◽  
Neutrino Sector ◽  
Left Handed ◽  
The Right

We build a supersymmetric model with [Formula: see text] gauge symmetry, with a global [Formula: see text] symmetry. The [Formula: see text] symmetry is necessary to keep the proton stable at least at tree level. There is also a global [Formula: see text] symmetry, where [Formula: see text] and [Formula: see text] are the usual baryonic and leptonic numbers, respectively. We introduce three nonidentical right-handed neutrinos plus new scalars fields. After symmetry breaking, the right-handed neutrinos together with one left-handed neutrino get Majorana masses via the seesaw mechanism. The other two left-handed neutrinos get their Majorana masses at 1-loop level. We will also explain the mixing angle in the neutrino sector in agreement with the experimental data and we get several interesting candidates to the observed dark matter.

Heating and Cooling of Food

2019 ◽  
Author(s):  
Alan Kelly
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Large Scale ◽  
The Other ◽  
Left Hand ◽  
Heating And Cooling ◽  
The Right ◽  
Liquid Flows ◽  
Simple Systems ◽  
Cold Liquid

As we have seen, heating of food is one of the oldest and most powerful ways of making food safe and stable, whether cooking a burger on a barbecue or pasteurizing juice, but is also a potentially highly damaging thing to do to many food products. So, it makes sense that a key principle of processing food is to understand how to control the flow of heat as precisely as possible. In Chapter 8, I introduced how we can maximize the efficient transfer of heat into and out of food in a kitchen in simple systems, like pots on stoves. In practice, in large-scale processes, to transfer heat efficiently from hot to cold, and in this way keep the lords of thermodynamics happy while minimizing damage to the food being heated, we need to use clever pieces of equipment, called heat exchangers (reflecting the fact that, just as the cold part of the system gets hotter, so the hot part gets colder in the deal; fair exchange is no robbery). To visualize a heat exchanger, imagine a simple metal tube, through which a cold liquid is flowing from one end to the other. Now surround that tube with a larger one, through which a hot liquid flows (as shown in Figure 11.1). The wall of the inner tube is exposed to cold on the inside and hot on the outside, and this temperature gradient is the pump that transfers heat across that wall, in nature’s obsessive quest for equality in all things temperature-y. So, now we have two tubes laid horizontally in concentric neatness, say with a hot and a cold liquid flowing in from the left-hand side; as they exit at the right-hand side, the outer hot liquid will be colder, and the inner liquid will have gained the lost heat and thus become hotter. If the tubes were sufficiently long, then both would come out at exactly the same temperature.

Molecular and morphological characterisation of two reproductively isolated species with mirror-image anatomy (Nematoda: Cephalobidae)

Nematology ◽  
1999 ◽  
Vol 1 (6) ◽  
pp. 591-612 ◽  
Author(s):  
Paul De Ley ◽  
Marie-Anne Felix ◽  
Linda Frisse ◽  
Steven Nadler ◽  
Paul Sternberg ◽  
...  
Keyword(s):  
Sequence Data ◽  
Large Subunit ◽  
Mirror Image ◽  
Valid Species ◽  
Rrna Gene ◽  
Separate Species ◽  
Dna Sequence Data ◽  
Left Handed ◽  
The Right ◽  
Large Subunit Rrna

Abstract Detailed descriptions are given of the amphimictic nematode strains PS1158, PS2052 and PS2160, which are unusual in that they only differ in predominant body handedness. Although these strains are morphologically identical in all other respects, published reproductive data and new DNA sequence data of the D2/D3 region of the large subunit rRNA gene show that they do represent two separate species. On the basis of comparison with type material, the left-handed strains PS1158 and PS2160 are identified as Acrobeloides bodenheimeri, and the right-handed strain PS2052 as A. camberenensis, which is re-instated as a valid species. A. bodenheimeri and its relatives exhibit various types of diagnostic and taxonomic problems at species level, and it is shown that D2/D3 sequence data provide an important new diagnostic tool for addressing these problems. Phylogenetic analysis shows that two right-handed parthenogenetic strains identified as A. maximus represent a third species which is more closely related to A. camberenensis than to A. bodenheimeri. Caracterisation morphologique et moleculaire de deux especes intersteriles de chiralite contraire (Nematoda: Cephalobidae) - Une description detaillee est donnee des souches amphimictiques de nematodes PS1158, PS2052 et PS2160, souches inhabituelles car differant par la chiralite du corps. Bien que ces souches soient morphologiquement identiques sous tout autre rapport, les resultats publies de tests de croisement et de nouvelles donnees concernant la sequence d'ADN de la region D2/D3 du gene de la grosse sous-unite d'ARN ribosomal montrent qu'elles representent en fait deux especes distinctes. Se fondant sur une comparaison avec le materiel type, les souches sinistres PS1158 et PS2160 sont identifiees comme Acrobeloides bodenheimeri et la souche dextre PS2052 comme A. camberenensis, ainsi retabli comme espece valide. A. bodenheimeri et les especes proches posent differents problemes diagnostiques et taxinomiques au niveau specifique, et nous montrons que les donnees de sequence D2/D3 fournissent un nouvel outil diagnostique important pour aborder ces problemes. L'analyse phylogenetique montre que deux souches parthenogenetiques dextres identifiees comme A. maximus representent en fait une troisieme espece, plus proche de A. camberenensis que de A. bodenheimeri.

Eppur si muove!

2001 ◽  
Vol 1 ◽  
pp. 147-180 ◽  
Author(s):  
Nicola Munaro ◽  
Cecilia Poletto ◽  
Jean-Yves Pollock
Keyword(s):  
Sharp Contrast ◽  
The Other ◽  
Striking Difference ◽  
Left Periphery ◽  
Left Edge ◽  
Comparative Syntax ◽  
Wh Questions ◽  
The Right ◽  
The Town

This article offers a comparative syntax approach to wh-questions in French and Bellunese, a Northern Italian dialect spoken in the town of Belluno. A striking difference between the two languages, otherwise very closely related, lies in the fact that bare wh-words in root questions, which display obligatory subject clitic inversion (SCLI), must appear at the right edge of the sentence in Bellunese. In French on the other hand apparent in situ structures ban SCLI and do not accept que in sharp contrast with Bellunese. To make sense of these data we suggest that despite appearances wh-words in Bellunese do move to the left periphery, just as they must in French SCLI structures. This in turn requires that the remaining IP also move to the left periphery which should then be “highly split”. The minimal parameter distinguishing French and Bellunese, we claim, lies in the existence of a class of non assertive clitics in Bellunese, which have turned into interrogative markers. Their absence in French triggers obligatory wh-movement to a high operator position at the left edge of the CP domain. In this light it is suggested that French wh in situ questions also involves invisible remnant IP movement and wh movement to a truncated left periphery.

scholarly journals II. The inheritance of sinistrality in Limnæa peregra ( Mollusca, Pulmonata )

1931 ◽  
Vol 219 (462-467) ◽  
pp. 51-131 ◽  
Keyword(s):  
Fresh Water ◽  
Mirror Image ◽  
Left Hand ◽  
Left Handed ◽  
The Difference ◽  
The Right

Limncea peregra is one of the commonest British fresh-water molluscs. Like other aquatic Pulmonates, it is hermaphrodite and breeds either by self- or cross-fertilisation. Normally the shell and body are coiled in a right-handed spiral (“dextral”) . Very rarely a reversed (“sinistral”) form occurs in which the whole symmetry is completely inverted : the shell and body are coiled in a left-handed spiral, the heart and kidney are reversed ; the rectum, penis and vagina open on the left-hand side of the neck instead of the right; the osphradium is on the left and the consequent asymmetry of the nervous ganglia is reversed. A sinistral snail is a complete mirror image of a dextral. The difference involves the whole development of each individual : it is apparent in the first division of the egg and obvious in the second. To be twisted either to the right or to the left seem to be the only available morphological possibilities. A shell which is not dextral is not necessarily sinistral, nor vice versa ; the shells might be coiled on the flat, something like a Planorbis . We have had a few of these monsters (fig. 8, Plate 10), of which the animals have been sinistral : if fertile they have normal dextral or sinistral young and appear to play no particular part in the genetic scheme. But a spiral mode of cleavage in the egg and a spiral twist in the soft parts of the adult seem to be essential qualities of gastropod mollusca, and an animal which is neither dextral nor sinistral is presumably impossible : the twist being obligatory there is no third alternative.

Sign in / Sign up

Export Citation Format

Share Document