bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parasitoids as a driving force in the evolution of the gall size of Urophora on Cardueae hosts
Authors: Zwölfer H , Arnold-Rinehart F 
Published: November 2023

Abstract
In the tephritid genus Urophora, gall forming evolved from non-galling ancestors whose larvae mined within the achenes and receptables of Asteraceae flower heads. In the Palearctic Urophora species an evolutionary trend to increase the proportion of lignified gall tissue can be recognized. This includes the transition from unilocular to multilocular galls. The structure and size of Urophora galls influences larval survival and parasitization rates by a complex of parasitoids with a distinct guild structure and an ancient and stable association with Urophora hosts. The available evidence leads to the conclusion that parasitoid pressure was one of the driving forces in the evolution of Urophora galls.
Strategy in the search for new biologically active plant constituents
Authors: Hostettmann K , Marston A , Wolfender J L 
Published: November 2023

Abstract
The plant kingdom represents an extraordinary reservoir of novel molecules. Of the estimated 250,000-500,000 plant species around the globe, only a small percentage has been investigated phytochemically and the fraction subjected to biological or pharmacological screening is even lower. Since plants may contain hundreds or even thousands of metabolites, there is currently a resurgence of interest in the vegetable kingdom as a possible source of new lead compounds for introduction into therapeutical screening programmes. The rapid disappearance of tropical forests and other important areas of vegetation has meant that it is essential to have access to methods which lead to the rapid isolation and identification of bioactive natural products.
Acetogenins from Annonaceae
Authors: Cave A 
Published: November 2023

Abstract
Acetogenins from Annonaceae are a series of C-35/C-37 natural products of polyketide origin derived from fatty acids. Their structure is characterized by a long alkyl chain bearing a terminal unsaturated methyl y-lactone (sometimes rearranged to a propanone y-lactone), one or two tetrahydrofuran rings, several oxygenated substituents (hydroxyl, acetoxyl, ketone), and in some cases a double bond and/or epoxy group (Fig. 10.1). To date, they have been isolated only from the Annonaceae.Annonaceous acetogenins exhibit a broad range of potent biological activities, especially antitumoural, cytotoxic, antiparasitic, and pesticidal properties.
Bioactive compounds from plants and higher fungi of Ethiopia
Authors: Dagne E , Abate D 
Published: November 2023

Abstract
The application of plants for medicinal purposes has been known to man since time immemorial. In Africa, as in many parts of the world, medicinal plants still play a pivotal role in treating the ill. It is estimated that the tropical African flora comprises over 30, 000 plant species grouped into about 2500 genera and distinguished by a high degree of endemism (Brenan 1978). Ethiopia, with its diverse topography including great mountain ranges, has a rich endemic element in its flora. Approximately 7000 higher plant species are known to occur in Ethiopia (Hepper 1979).
Panamanian flora: source of bioactive compounds
Authors: Gupta M P 
Published: November 2023

Abstract
The isthmus of Panama joins North and South America and contains a mixture of the biota in these two parts of the continent. This geographical position and its typical tropical climate have given rise to great biological diversity. For example, the flora of Panama is one of the 25 richest in the world: it has been estimated that there are between 8000 and 10000 vascular species in Panama, of which 17.3 per cent are endemic. There are also large numbers of non-vascular species, but these have not been fully investigated. Tables 16.1 and 16.2 give general information about the Panamanian flora.
Partitioning of photosynthetic carbon: the role of nitrate activation of protein kinases
Authors: Foyer C H , Champigny M L , Aladier M -H V , Ferrarii S 
Published: November 2023

Abstract
Sucrose is the main product of photosynthesis in crop plants, but photosynthesis is also required for primary nitrogen (N) assimilation in leaves. The reductive assimilation of N0-to the level of glutamine (Gin) and glutamate (Glu) must be coordinated with photosynthesis, since the energy required for the assimilation process is derived from photosynthetic electron flow, and the carbon (C) skeletons needed for amino acid synthesis are provided by photosynthetic CO assimilation. In addition, it is evident that complex molecular strategies are employed to regulate the partitioning of photosynthetic C between sucrose and amino acid synthesis. Over large distances, for example between the shoots and roots, cycling of N and C compounds allows information on the C and N status to be conveyed from one tissue to another. This is used to modulate N-absorption in the roots to match the demand for N. In the leaf cytoplasm, a multifactorial network of regulatory processes is employed to modulate the relative fluxes of assimilated C through the two metabolic pathways. The levels of sucrose and amino acids in the foliar cytosol act as endogenous regulators at the molecular and metabolic levels. Sucrose-phosphate synthase (SPS), nitrate reductase (NR), and phosphoenolpyruvate carboxylase (PEPCase) are considered to be the gateways to the assimilatory pathways of sucrose synthesis and N assimilation and the anaplerotic pathway respectively. These cytosolic enzymes are modulated in response to the addition of N to the plants and their activities vary with the rate of photosynthesis. The regulation of PEPCase and NR gene expression by N is well characterized as is the regulation of NR gene expression by sucrose (Cheng et al. 1986; Galangau et al. 1988; Sugiharto and Sugiyama 1992). In addition, all these enzymes are subject to covalent modulation via protein phosphorylation (S.C. Huber et al. 1994). NR and SPS, for example, are inactivated rapidly by phosphorylation in response to changes in irradiance or CO2 supply.
Molecular and biochemical properties of calmodulin-like domain protein kinases
Authors: Harmon A C , Yoo B -C , Lee J -Y , Zhang Y , Roberts D M 
Published: November 2023

Abstract
Diverse stimuli such as growth regulators, stress, pathogen attack, and red light elicit responses by affecting changes in intracellular free calcium concentration in plants. How a single second messenger, Ca+,is involved in bringing about different responses is under current investigation. While the complete answer is not yet known, it is clear that there are many high affinity calcium-binding proteins in plants that differ in function and these proteins are likely to contribute to the specificity of responses. There are several isoforms of calmodulin and of the calmodulin-like domain protein kinase (CDPK), as well as other proteins that are predicted to be calcium-binding proteins. Differences in the Ca+ sensitivity, location, and target proteins with which each interacts would confer specificity as far as which types of calcium signals may be sensed, and which response pathways are turned on.
Plant protein phosphorylation in signal transduction and the control of development: cloning and characterization of protein kinase genes from Arabidopsis and Petunia
Authors: Tregear J W , Decroocq-Ferrant V , Thomas M , Bianchi M W , Le Guen L , Lessard P , Lecharny A , Kreis M 
Published: November 2023

Abstract
Although studies on signal transduction in plants have traditionally lagged behind those on animal and fungal systems, it is becoming increasingly clear that many basic signalling components are conserved between all three groups of organisms. Information previously obtained from other eukaryotic systems has provided a means to study related mechanisms in plants, thus providing the first glimpses of how plant cells respond to both internal and external signals. During evolution, signal transduction components appear to have been conserved not only as individual entities, but also in groups in the form of signal transduction ‘modules’. Our interest in studying the mechanisms controlling development and metabolism in higher plants has led us to look in Arabidopsis thaliana and Petunia hybrida for homologues of protein kinases which might form part of these evolutionarily conserved modules.
Visual motion processing for figure/ground segregation, collision avoidance, and optic flow analysis in the pigeon
Authors: Frost Barrie J , Sun Hongjin 
Published: November 2023

Abstract
In a very rich diversity of species, spanning essentially the entire animal kingdom, one finds great similarities in the fundamental mechanisms that have evolved to process vision. For example we find that vertebrates and invertebrates alike have very circumscribed areas of their visual field specialized for higher acuity or other functions, which result in single or multiple foveae, visual streaks, and even bi- or multifocal optical systems.
Small size in amphibians-its ecological and evolutionary implications
Authors: Clarke B T 
Published: November 2023

Abstract
An overview of the ecological and evolutionary implications of reduced body size in amphibians is presented. Three significant formative influences in the evolution of the modern lissamphibian morphotypes-the limbless, worm-like caecilians, the tailed tetra podurodeles, and the squat, tailless anurans-are outlined. These influences are the shift from an aquatic to a terrestrial lifestyle, the development of concealment and water conservation strategies leading to fossoriality, and a reduction in body size. The last of these ultimately leads to the evolution of extremely small adult body size and is examined in greater detail. Miniaturization may occur sporadically in distantly related forms or in more closely related species, within a monophyletic lineage. Two kinds of miniaturization are identified-primary andsecondary. Primary miniaturization involves some form of radical morphological reorganization. Secondary miniaturization produces morphologically simi lar forms differing mainly in size. A systematic survey of small and miniature amphibians is presented and comment is provided on the morphological consequences of size reduction for each of the three amphibian orders. The ecological, behavioural, and evolutionary advantages of reduced body size to small and miniature amphibians are discussed. The need for further data, particularly accurate ecological and behavioural observational work, is noted.
Carotenoids and colour in fruit and vegetables
Authors: Britton George , Hornero-Méndez Dámaso 
Published: November 2023

Abstract
Carotenoids and anthocyanins are the most important pigments for providing attractive colours in fruit and vegetables. In contrast to the water-soluble anthocyanins, the carotenoids are water-insoluble, isoprenoid lipid molecules, and are usually located in membrane structures in discrete organelles, namely chloroplasts (in green tissues) or chromoplasts (in yellow, orange or red tissues). Carotenoids may be found in, and may provide or contribute to the colour of, all parts of plants: roots, leaves, flowers, fruit and seeds.
Phenolic compounds and oxidative mechanisms in fruit and vegetables
Authors: Amiot Marie J , Fleuriet Annie , Cheynier Veronique , Nicolas Jacques 
Published: November 2023

Abstract
Phenolic compounds form one of the main classes of secondary metabolites with a large range of structures (Table 4.1; Fig. 4.1), and contribute to the organoleptic and nutritional qualities of fruit and vegetables (Macheixet al.,1990). Oxidative mechanisms involving phenolic compounds may modify the quality of fresh or processed fruit and vegetables. Enzymatic browning is one of the main oxidative phenomena inducing the development of undesirable colour, flavour and a loss of nutrients. In heat-processed fruit and vegetables products, non-enzymatic browning (Maillard reaction) can also occur. In some cases, such as in plums, figs or dates, enzymatic browning is required for quality.
Aroma biochemistry of fruits and vegetables
Authors: Sanz Carlos , Olias Jose M , Perez Ana G 
Published: November 2023

Abstract
Aroma compounds contribute heavily to the overall sensory quality of fruit and vegetables. Aroma is a complex mixture of a large number of volatile compounds whose composition is specific to species and often to variety. In some cases the typical fruit and vegetable aromas can be ascribed to a specific compound, although in general the overall aroma quality is the sum of a multitude of compounds. At present, it is difficult to ascertain the relative contribution of each volatile component to a characteristic or a desirable aroma. During the last three decades, physicochemical methods of analysis, such as spectrophotometry, nuclear magnetic resonance, and specially gasliquid chromatography coupled to mass spectrometry allowed the isolation and identification of a large number of volatile compounds from plant aromas. However, rather less work has been done on elucidating the aroma formation mechanisms. These valuable studies are only a beginning to the process of understanding and regulating the aroma quality of fruits and vegetables. In this sense, biotechnological applications for aroma-determining substances in the food industry may support studies leading to a deeper knowledge of aroma biochemistry, since chemical synthesis cannot completely fulfil the requirements of specific chirality found among some aroma impact compounds, or the increasing demand for natural compounds by consumers.
Potentially anticarcinogenic secondary metabolites from fruit and vegetables
Authors: Hertog Michaël G L , Van Poppel Geert , Verhoeven Dorette 
Published: November 2023

Abstract
Cancer embraces a group of diseases which have in common that a cell or a group of cells is altered in such a way that it escapes growth control and replicates, thus prohibiting a normal functioning of the organ in which these cells are located. There is overwhelming evidence from experimental and epidemiological studies that most common forms of human cancers are related to environmental life-style factors such as diet, in combination with genetic factors that influence the susceptibility of individuals to these factors (Doll and Peto, 1981; Steinmetz and Potter, 1991a; Marshall, 1991). A large number of epidemiologic studies have shown that the consumption of vegetables and fruit is inversely associated with risk of cancer, particularly cancers of the alimentary and respiratory tract (Blocket al.,1992). Vegetables and fruit contain a large number of components that could, by a variety of mechanisms, explain these cancer-protective effects. Until recently, most attention has been paid to vitamins such as vitamin C, pro-vitamin A, and dietary fibre in these foods but in recent years it has been shown that these plant tissues contain a whole variety of potentially anticarcinogenic secondary metabolites. These include, amongst others, flavonoids, phenolic acids, terpenes, glucosinolates, and carotenoids (Table 16.1). The term ‘secondary metabolite’ refers to compounds that are not essential to the survival of the whole plant or certain parts of the plant.
The Biological Basis Of Human Patterns Of Mating And Marriage
Authors: Reynolds Vernon 
Published: November 2023

Abstract
Mating and marriage are very different kinds of things. Mating is a kind of behaviour, and is found in all animal species. Marriage is a social institution and, like other such institutions, is found only in human society.
I shall begin by discussing mating rather than marriage, and this will be mainly in the context of non-human primates rather than humans. Secondly, I shall look at human mating patterns in relation to the structure of the human body, and critically assess some scenarios of the original condition of man. Thirdly, I shall look at human marriage patterns and the phenomenon of marriage itself in relation to mating. Fourthly, I shall attempt some reconciliation between the principles of systems of marriage and systems of mating, and try to see whether marriage itself is comprehensible in biological terms. Finally, I shall look at the question of how and why marriage came into existence at all, and try to draw some conclusions.
The pelagic ecosystem
Authors: Hecky R E 
Published: November 2023

Abstract
The structure and function of Lake Tanganyika’s pelagic ecosystem has great relevance to aquatic sciences in general as well as its own intrinsic significance to the human economy of the lake and its environs. The pelagic ecosystem accounts for most of the production of organic carbon in the lake (Hecky & Fee, 1981), and the pelagic fishery, when fully developed, will account for most of the fish yield (Chapt. 7). The most intensively exploited areas yield higher catches per unit area than any other great lake, with a carbon transfer efficiency from primary production to fish production as high as the most efficient marine fisheries (Hecky et al.,1981). Although other great lakes are as large, none of them have Tanganyika’s unique hydrography which accentuates the importance of the pelagic system. Because of its great size, great age, and long water and elemental residence times, the lake occupies an intermediate position on the time and space scales which extend from small lakes to the worlds oceans.
The benthic fish community
Authors: Coulter G W 
Published: November 2023

Abstract
There is a remarkable benthic fish community in deep water in Lake Tanganyika that is rich in endemic species and genetically diverse. Its lower limit is determined by oxygen concentration, some species ranging down to about 200 m depth at the south of the lake where the oxygenated layer is deepest. There is also a group living above the bottom that may more properly be termed bathypelagic. Many of these species occupy wide ranges of depths. Some remain all their lives in deep water while others make diurnal or periodic migrations inshore. They occupy environments much different from those of the littoral or pelagic communities, and should be regarded as an ecologically distinct category.
Steady-State and Transient Operation Of Synchronous Machines and Synchronous Motor Drives
Authors: Vas Peter 
Published: November 2023

Abstract
In the normal configuration, a three-phase synchronous machine has a symmetrical three-phase winding on its stator, which is sometimes also referred to as the armature winding, and it is similar to the stator winding of a three-phase induction machine. Its rotor can be either cylindrical or it can have salient poles, as shown in Fig. 2.25. As discussed in Section 2.7.6.2, on the rotor their is a field winding which is excited by d.c., and it is connected to the external d.c. source via slip rings and brushes. Sometimes there are no brushes, but there is brushless excitation by (rotating) diodes. Further-more, sometimes there are also damper windings on the rotor, the roles of which have been described in Section 2.7.6.2. Steam turbine driven synchronous machines (turbogenerators) run at high speeds (they have 2–4 poles) and are equipped with cylindrical rotors, since this construction is mechanically more reliable (it withstands the centrifugal forces at high speeds) than a salient-pole construction. However, water-driven generators (hydrogenerators) and also smaller independent generators (for example, used in emergency power supplies), run at relatively low speeds (a few hundred revolutions per minute) and they are constructed with salient poles (since this requires a larger number of poles; see eqn (4.1-1)). It should be noted that it is possible to construct a three-phase synchronous machine where the d.c. excitation winding is on the stator and the three-phase winding, supplied by a.c. is on the rotor, (inverted machine). However, this would require an increased number of slip rings and the currents through the slip rings would be large. It is an advantage of the application of the wound-rotor machine that the excitation flux can be varied to operate the synchronous machine with any desired value of power factor, which can be lagging, unity, or leading.
Motor And Controller Types
Authors: Hendershot J R , Miller TJE 
Published: November 2023

Abstract
There are several different configurations of brushless motors which use rotating permanent magnets and stationary phase coils. The main reason for so many different variations has to do with the utilization of different magnet grades in addition to the wide range of applications. For example, if an application requires rapid acceleration and deceleration of the load (as in servo systems) then the torque/inertia ratio should be as high as possible. This indicates the use of an interior-rotor motor with high-energy magnets.
Control Systems Performance
Authors: Gray G 
Published: November 2023

Abstract
Brushless permanent-magnet motors have a linear torque/current characteristic, low torque ripple, and fast response. This makes them highly suitable for controlling speed, position or torque, either in a single-quadrant variable control mode, or as four-quadrant servomotors with reverse speed capability and dynamic braking. This chapter describes the brushless permanent-magnet motor and its controller as a control system. It includes a review of the simplified mathematical models that describe the motor and controller, followed by the main types of control system. Control system design is described in relation to closed-loop operation, frequency response, step response, stability, steady-state error, root loci, lead/lag compensation, pole placement, and robustness. The design and tuning of PID controllers is discussed in both linear (analog) and digital forms. Z-transform methods are described for discrete digital systems. The chapter concludes with a review of modern control methods including adaptive control, optimal control, and observers.
Basic algebra of matrices
Authors: Barnett Stephen 
Published: November 2023

Abstract
The first step in the development of matrix algebra is to denote an array by a single letter-almost invariably an upper case (‘capital’) letter is used, for example In some books bold type, A, is used for matrices. The numbers in the array are called the elements of A. The standard notation for elements is to use the same letter but lower case, and with two suffices which describe the position of an element.
Unique solution of linear equations
Authors: Barnett Stephen 
Published: November 2023

Abstract
In this chapter we shall study the solution of n simultaneous linear equations inn unknowns x1, x2,…xn in the form It is tempting to try to extend the ideas of matrix algebra developed in Chapter 2 so as to include ‘division’. We could then solve (3.2) by writing x = b + A, or borrowing the notation from ordinary algebra, If we could find the matrix denoted by A–1, in (3.4), then this would give the desired solution vector x. However, it turns out that the best way to proceed is the reverse: we solve the equations, and then use this solution to find the matrix A-1• The second part of this procedure will be delayed until Chapter 4.
An Introduction To Sampling Theory
Authors: Higgins J R 
Published: November 2023

Abstract
Series of this kind and their generalizations and extensions form the subject matter of this book.On the theoretical side, sampling theory methods interact with fields such as interpolation a.nd approximation, special functions and the expansion of special functions in series, expansions associated with eigenvalue problems, constructive function theory, entire functions and the Paley-Wiener theory, numerical analysis and harmonic analysis.