bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular cloning of differentially expressed and cell cycle-related cDNAs in the maize root apex
Authors: Sabellil P A 
Published: November 2023

Abstract
Recent work on lower (yeast) and higher eukaryotic cells (animals and plants) has resulted in a consensus picture of the molecular factors which control the cell cycle. It is clear that the master cell cycle regulators are highly conserved across species and the progression of the cell cycle is regulated by very similar sets of molecules in all eukaryotic cells. It is also widely recognized that protein phosphorylation is central to cell cycle regulation in eukaryotes. However, different organisms are not only characterized by obviously different developmental patterns and lifestyles, but are also likely to have developed specific mechanisms for the spatial and temporal control of cell division. Here we briefly describe some of the more remarkable features of cell proliferation in higher plants as opposed to the cell cycle in yeast and animals. We also describe the root apex of maize which represents our experimental system to identify both evolutionary conserved genes encoding key cell cycle regulators and novel plant genes which may play important roles in the coordination of cell cycle events in relation to the organization of the meristem and plant development.
Expression of CDK gene variants and p34cdc-related protein kinase activities in synchronized alfalfa cells
Authors: Magyar Z , Meszaros T , Feher A , Brown S , Deak M , Bottka S , Gyorgyey J , Pongor S , Dudits D 
Published: November 2023

Abstract
The central role of p34cctc2-related kinases in control of cell cycle progression has been shown in a great variety of eukaryotic cells. In yeasts the cdc2/CDC28 genes encode the p34 serine/threonine protein kinase required for S phase and entry into mitosis. The p34cctcltcocs catalytic subunit requires association with a cyclin regulatory subunit for kinase activity. The cyclin-dependent protein kinases (CDKs) are complexed with different cyclins and extensively regulated by phosphorylation (reviewed by Solomon 1993). In multicellular eukaryotes different cyclins bind different CDKs during progression through various phases of the cell cycle (Pines 1993). The phylogenetic conservation of the p34cctc kinase function has allowed the identification of several plant homologues of the cdc2/CDC28 genes and the complementation of yeast mutation by plant cdc2 cDNAs (Hirayama et al. 1991; Hirt et al. 1991; Ferreira et al. 1991; Colasanti et al. 1991). Sequence analysis and functional characterization of various cdc2 gene variants revealed differences between plant cdc2 genes (Miao et al. 1993; Hirt et al. 1993). Differential expression of cdc2 genes was also detected after hormone treatment and in various tissues and organs of plants (Hirt et al. 1991; Martinez et al. 1992; Magyar et al. 1993; Fobert et al. 1994).
Introduction
Authors: Tomás-Barberán Francisco A , Robins Richard J 
Published: November 2023

Abstract
Secondary metabolites play a number of crucial roles in fruit and vegetables, being responsible for colour, appearance, flavour and taste. Thus, it is primarily the content of these metabolites within the product that is also responsible both for consumer selection of the commodity and for the enjoyment derived from its consumption. While it has long been recognized that ‘fruit and vegetables are good for you’, studies of fruit and vegetables over the last few years have demonstrated that these products contain constituents—notably vitamins and fibre—essential to a healthy, well-balanced diet. Furthermore, it has also been shown that some of the secondary metabolites of fruit and vegetables are beneficial to health in directly combating the onset of cancer and coronary diseases.
The emergence of stratigraphy
Authors: Hallam A 
Published: November 2023

Abstract
Generations of British and American geologists have been indoctrinated as students with the view that the English canal surveyor William Smith (1769-1839) was the father of stratigraphy. This has never been accepted, with good reason, on the European continent, where stratigraphy has been perceived as emerging gradually from a long tradition dating well back into the eighteenth century, with the seminal influence deriving from Werner.
The Ice Age
Authors: Hallam A 
Published: November 2023

Abstract
What are nowadays universally seen as deposits directly or indirectly due to glacial activity provided in the early part of the nineteenth century some of the strongest evidence in support of the diluvialist school of thought. Vast tracts of land in Northern Europe and around the Alps had long been known to be mantled by a chaotic assemblage of sediments ranging from muds, silts, sands, and gravels, which frequently had contorted structures, to extremely poorly sorted deposits we now refer to as till, with pebbles and boulders of rock embedded in a fine-grained matrix.
The age of the earth
Authors: Hallam A 
Published: November 2023

Abstract
It is customary for us nowadays to chuckle at Archbishop Ussher’s famous calculation that the earth was created in 4004 BC on 26 October at 9.00 a.m! Such an attitude fails to do justice to the highly scholarly tradition of textual and historical criticism within which Ussher worked, as a figure much respected by his contemporaries.
General considerations
Authors: Hallam A 
Published: November 2023

Abstract
This book is as much about scientists as ideas, or rather about the interaction of scientists with each other and the ideas they have argued about. Indeed, the recurring appearance in the text of leading scientists provides more of a link than the controversies that have been reviewed successively. It is an oversimplification if not a downright distortion to dub these figures radicals or reactionaries with respect to established theory, and any attempt to extend such a one-dimensional classification to those persons involved in more than one controversy is doomed. The transition through an individual lifetime from young turk to old fogey is in some cases clear to see.
The Evolution of Animal Mating Systems
Authors: Rees Jane A , Harvey Paul H 
Published: November 2023

Abstract
Attempts by evolutionary biologists to make sense of the natural diversity of animal mating systems typically employ observation, experiment, and theory. Inspection of the immense literature reveals that much of the work centres on interpreting mating systems within a long-standing tradition of evolutionary biology, that of sexual selection theory with its consequences for parental investment. As this chapter will illustrate, this approach has taken us a long way. But scientists cannot divorce themselves from their intellectual backgrounds and many studies have been coloured by inadequate theory. Indeed, incorrect assumptions underlying contemporary theory may have hindered the comprehension of mating systems as a whole. For example, it has often been assumed that variance in reproductive success among females is much less than that found among males. The general picture that emerged from making this assumption portrayed males as actively attempting to maximize the number of copulations they could achieve, while females were more choosy about who they mated with. It was also assumed that females bore the costs of reproduction almost exclusively. This was the paradigm that behavioural scientists were brought up on, so it is not surprising that their assumptions were not questioned when biased questions brought stock answers (perhaps the fact that similar sexual stereotypes exist in Western white middle-class culture made the errors less apparent). In more recent studies which have not made these assumptions, a somewhat different picture emerges.
Main circuit of brushless servomotors
Authors: Dote Yasuhiko , Hashimoto Yukio 
Published: November 2023

Abstract
The main circuit of a brushless servomotor is equipped with semiconductor devices capable of self-switching off and high-speed switching. They have been developed by applying the techniques of power electronics and micro-electronics and are classified into bipolar transistors, MOSFETs, GTOs, and SITs. They enable not only frequency control but also very rapid voltage and current wave generation very rapidly: in other words, they make possible the motor torque control, which is critical to motor controls. These power semiconductor switching devices are produced in modular form to be used in the main circuit, the configuration of which is shown in Fig. 5.1.
Examples of selection and application of brushless servomotors
Authors: Uchiyama Shunichi 
Published: November 2023

Abstract
Motors are indispensable for industrial equipments used in industry and everyday life. They come in a considerable number of varieties. In the past, the output of a single motor has often been distributed to several users. Today in the age of sophisticated automation, each actuator is frequently equipped with its own motor. Consequently, a wide range of information is required in selecting motors. This chapter will provide basic information necessary for machine designers in selecting optimal motors and to make optimal use of them.
General Introduction
Authors: Hendershot J R 
Published: November 2023

Abstract
A brushless motor, as its name suggests, is a motor without brushes, slip rings or mechanical commutator, such as are required in conventional DC motors or synchronous AC machines for connection to the rotor windings, [1,2]. Several motors satisfy this basic definition. The commonest is the AC induction motor, in which current in the rotor windings is produced by electromagnetic induction. As an AC motor, the induction motor employs a rotating magnetic field that rotates at a synchronous speed set by the supply frequency. However, the rotor rotates at a slightly slower speed because the process of electromagnetic induction requires relative motion, or slip, between the rotor conductors and the rotating field.
Magnetic Design
Authors: Miller TJE 
Published: November 2023

Abstract
The flux in a brushless permanent-magnet motor is established by the magnets. We have seen in Chapter 1 that the torque is proportional to the current and the flux, while the no-load speed is proportional to the voltage and inversely proportional to the flux. The flux is clearly a most important parameter in the design. This chapter describes the simplest methods of calculating it, for later use in the calculation of the EMF and torque equations and the speed/torque characteristic. The simplest motor is the 2-pok motor, Fig. 4.1. The flux is intended to link the coils of the phase windings on the stator, and these coils are located as close as possible to the magnet to minimize the amount of magnet flux that “leaks” from the N pole to the S pole without linking any turns of the windings.
Electronic Commutation Of Squarewave Motors
Authors: Miller TJE 
Published: November 2023

Abstract
This chapter describes the process of electronic commutation in squarewave brushless DC motors and their controllers. It also describes the differential equations used by the PCrBDC computer program for the dynamic simulation of 3-phase squarewave brushless DC motors, with wye, delta, and unipolar half-bridge connections. The commutation process is important for detailed understanding of the switching of the power transistors.
Magnetic Materials
Authors: Staton D A 
Published: November 2023

Abstract
This chapter reviews the material properties of permanent magnets, electrical steel and insulated wire. There is still widespread use of c.g.s. units in the magnet industry, whereas motors are usually designed in metric (SI) units in Europe and Japan, and in metric or mixed units in the USA. The most important magnetic conversion factors are given in Chapter 4. A brief description of the characteristics, parameters and equations associated with permanent magnets is given here, i.e. the normal and intrinsic hysteresis curves, major and minor loops, temperature effects, energy product, magnetization, etc. More detailed descriptions can be found in specialist works on permanent magnets, e.g. [1].
Artificial-intelligence-based switched reluctance motors, estimation, design, and control
Authors: Vas Peter 
Published: November 2023

Abstract
In a recent book [Vas, 1998], the fundamentals of switched reluctance motor drives were discussed together with various position estimators which can be used in position sensor less switched reluctance motor drives. Furthermore two main solutions for instantaneous torque-controlled switched reluctance motor drives have been discussed. The first solution uses profiled stator currents, and thus the drive contains a current controller, but the second solution uses profiled stator flux linkages, and the drive scheme contains a stator flux linkage controller. It has been shown that the second scheme is simpler to implement. Both schemes can operate in a wide speed range and offer the potential of using switched reluctance motors in many applications, where so far only other types of motors have been used.
Numerical methods for optimal control problems
Authors: Hocking Leslie M 
Published: November 2023

Abstract
Although a great deal can be learnt from closed-form solutions of optimal control problems, in general the solution of such problems can only be obtained by computation. Some numerical methods that can be used to solve optimal control problems are discussed in this chapter. Since the time-optimal principle TOP derived in Part A provides a criterion for the optimal control that is identical to that derived from the PMP as applied to time-optimal problems (see §9.1), we need only discuss the way in which the PMP can be implemented in a numerical solution of a general optimal control problem. The development of appropriate algorithms for such problems is fraught with obstacles, and it does not seem possible to produce schemes that will apply in general. Each problem, or class of problems, has to be considered on its own; all that can be done here is to describe methods that work in some specific cases.
3 How to compare two knots
Authors: Hemion Geoffrey 
Published: November 2023

Abstract
Let us consider the BASIC PLAN for solving the knot problem. The idea is very simple. It does not involve complicated algebraic structures. We need not burden ourselves with group theory, rings, modules, or polynomials. All that is needed is elementary common sense, combined with a few basic ideas from the theory of topology. Now as a basic philosophical principle the problem of comparing two complicated things with one another must always be reduced to the problem of comparing many simpler things. And in fact the simpler things must each be so simple as to allow the human (or even the mechanical) mind to compare them at a single glance. For example, let us imagine that we have two books, and the question arises as to whether or not they are the same. If their covers are different, then the problem has been solved; they are different. But even if the two books appear to be similar from the outside, still that is no guarantee that they are similar inside. The only way to be sure is to go through both of the books together and compare them, word for word—or even letter for letter. For this purpose, modern society has learned to appreciate the advantages of electronic computers.
Fundamental solutions
Authors: Hemion Geoffrey 
Published: November 2023

Abstract
We can apply this result in the theory of Diophantine inequalities to the basic plan for classifying Haken manifolds. Remember that the 3-manifold M consists of tetrahedrons—that is, a set of sets of four vertices. Furthermore, any normal surface consists of squares and triangles in the tetrahedrons. It is easy to see that any arbitrary normal surface can be completely specified by simply supplying a list of squares and triangles. But as far as the computer is concerned, a square is given by specifying which tetrahedrons Δ we are to take, and then specifying the way the square splits the four vertices into two pairs. In the case of the triangle we only need to specify the single vertex which is isolated from the other three by the splitting.
Why is the ‘difficult’ case difficult?
Authors: Hemion Geoffrey 
Published: November 2023

Abstract
It is true that the reader may have experienced difficulties in following the unwinding operations of the last chapter. Nevertheless, that is not the true difficulty. As far as programming the algorithm into our hypothetical computer is concerned, it is easy to set a somewhat larger—but finite—limit on the number of fundamental surfaces of zero complexity which are to be brought into consideration. The true difficulty lies in a completely different direction. As a matter of fact, I have neglected to mention a certain very critical detail. For let us think about the whole reduction process which is the basis of our plan for classifying knots. At each stage it involves splitting the given 3-manifold M along an incompressible surface, and in the process drawing lines along the newly-opened boundaries of the resulting 3-manifold, thereby giving a boundary pattern to aid us in gluing things back together again.
The hyperbolic plane
Authors: Hemion Geoffrey 
Published: November 2023

Abstract
To proceed, and in particular to understand the arguments in the Appendix, it is necessary to know a few facts about the hyperbolic plane. The hyperbolic plane is something of very great historical interest, so we will pause for two chapters in order to become acquainted with it. But to begin, let us go way back in the history of science and recall Euclid’s classical postulates of geometry.
The size of a homeomorphism
Authors: Hemion Geoffrey 
Published: November 2023

Abstract
In Chapter 15 it was shown that the problem of classifying Stallings fibrations is equivalent to the problem of classifying homeomorphisms of compact surfaces. Therefore we will concentrate on surfaces alone and allow ourselves to forget—for the time being at least-the more complicated problems which can occur in three dimensions. But even going beyond this, we will also rule out the case of compact surfaces without boundary. After all, a knot space does have a boundary to begin with. Then at each stage of the splitting of the knot space we must continue to deal with 3-dimensional pieces which have boundaries. On the other hand, a Stallings fibration over a surface without boundary must be a 3-manifold which itself has no boundary.
Small curves
Authors: Hemion Geoffrey 
Published: November 2023

Abstract
How can we prove that there is a number such as N of the previous chapter, which gives us a limit on the size of possible conjugating homeomorphisms which are to be investigated? Again, this question is too difficult to answer directly. The trick which I used was to first prove that a ‘small’ closed curve c must exist on the surface S. Now the idea of smallness is easy to define for curves on S. Let c be some arbitrary curve on S. The curve will be assumed to be closed, in the sense that its starting point is the same as its endpoint. Put another way, c is a mapping of the circle (the I-sphere) into S. We can assume that c is in general position with respect to the set of curves {ζ1, ... , ζn}. Then c generally passes through the fundamental region Δ of S in a number of arcs. The size of c is defined to be this number. Thus we shall say that c is small if its size is small.
Classifying mappings of surfaces
Authors: Hemion Geoffrey 
Published: November 2023

Abstract
Let f and g be two given homeomorphisms of a surface S onto itself. We have seen in Chapter 18 that homeomorphisms can be described in terms of lists of numbers. Furthermore the lengths of these lists are no greater than the size of the homeomorphism. The question is, does there exist a further homeomorphism h: S→ S such that f is isotopic to h-1 gh? According to the reasoning of the last chapter, we can find a definite (but large) number M(f, g), which depends only on the sizes of the known homeomorphisms f and g, such that if there exists a conjugating homeomorphism, then there also exists one of size no greater than M(f, g). (This is the number referred to as N in Chapter 18.) It is now, in principle at least, a simple matter to go through and check all possible homeomorphisms of size less than this number, looking for some conjugating homeomorphism. Our hypothetical computer will be set the task of going through all lists of lists with no more than M(f, g) entries. Of course it is true that most lists which might be chosen at random will not represent homeomorphisms of the surface. A number of rules will have to be formulated to identify lists which do, in fact, represent homeomorphisms. Furthermore, combinatorial rules will have to be formulated to identify a conjugating homeomorphism during the search. These are routine tasks which we can leave to the hypothetical programmer of our hypothetical computer.
The final result
Authors: Hemion Geoffrey 
Published: November 2023

Abstract
We are left with the task of relating this theory to the argument of Chapter 13. As we have seen in Chapter 3, the classification algorithm involves splitting 3-manifolds along incompressible surfaces to obtain, in the end, 3-cells with boundary patterns. This works fine except in the case that a piece suddenly appears which is a Stallings fibration containing no incompressible tori. How does the computer know when it is dealing with this case? Let M be the given 3-manifold which we know is a Stallings fibration.
From Finite To Infinite Sampling Series
Authors: Higgins J R 
Published: November 2023

Abstract
An interesting question, which has come up from time to time in the research literature, is whether sampling theorems involving infinitely many sampling points can be derived as limiting cases of finite sampling theorems. Indeed, the cardinal series arises as a formal limiting case of the finite Lagrange formula (the right-hand side of (1.2.1)), as we shall mention in a moment; but a fully rigorous treatment of this limiting procedure was not given until very recently. The present chapter is devoted entirely to the discussion of this problem by Hinsen and Klösters (1993).
Examples of Ockham algebras; the Berman classes
Authors: Blyth T S , Varlet J C 
Published: November 2023

Abstract
Recall that a distributive Ockham algebra is an algebra (L; ∧, v,f, 0, 1) of type (2, 2, 1 , 0, 0) in which (L; /\, V, 0, 1) is a bounded distributive lattice and x ↦ f(x) is a unary operation such thatf(0) = 1, f(l) = 0 and Without explicit mention to the contrary, all the Ockham algebras that we shall deal with will be distributive as lattices so we shall agree to drop the adjective ‘distributive’ and talk of an Ockham algebra. We shall often also denote this by the simpler notation (L;f).
Congruences on double MS-algebras
Authors: Blyth T S , Varlet J C 
Published: November 2023

Abstract
We now turn our attention to congruences on double MS-algebras. Here also an important role is played by the principal congruences ϑ (a, b) with a≤ b. It is clear from Theorem 2.1 that if L∈ DMS and a, b ∈ L are such that a ≤b then we have [ueq]Arguing precisely as in Theorem 8.1, we can characterise ϑ(a, b) as follows.
SecD and SecF
Authors: Pogliano K J , Beckwith J 
Published: November 2023

Abstract
Mutations within the secD locus were selected by their ability to cause internalization of an alkaline phosphatase-galactosidase fusion protein or to cause the induction of the secA gene1-2-3. Conditionally-lethal (cold-sensitive) and non-conditional mutations have been detected. Both classes of mutants accumulate the precursors of exported proteins at the permissive temperature of 37°C, and this secretion defect rapidly becomes worse at 23°C4. secD and secF mutants are indistinguishable except by complementation. It has been observed recently that null mutations lacking secD and secF are cold-sensitive for growth and have a severe protein export defect5. Overexpression of Sec D and SecF improves the export of proteins with defective signal sequences5.