Inter-Regional Transfer Trade Flows in the English Football League

This paper examines the pattern and extent of inter-regional transfers of professional footballers between clubs in the English football league system over the period 1990-1991 to 1999-2000. Our study emlploys a variant form of an established trade flow model and, in presenting and confirming tbe pattern and extent of inter-regional transfers, it indicates the wider applications of the conventional trade model.

Influence of phytophagous behaviour on prey consumption by Macrolophus pygmaeus

Omnivorous Heteroptera constitute an important component of predatory guilds with high potential for biological control. Understanding the relative effects of plant feeding on the suppression of prey by omnivores could be an important element for improving biological control strategies. In the current paper, the effects of different plant food sources on the predation rate of the omnivorous predator Macrolophus pygmaeus (Hemiptera: Miridae) were examined. In all the experiments, second instar nymphs of the aphid Myzus persicae (Homoptera: Aphididae) were used as prey at different densities. First, we evaluated the rate at which the predator preyed on M. persicae at various prey densities on pepper and eggplant leaves. Then, using eggplant flowers or pollen as additional food sources, we estimated predator efficiency for three different prey densities. The predation rate was not affected by the type of plant leaf used. However, the results showed that the predation rate of M. pygmaeus was significantly reduced when flowers or pollen were provided at high prey densities. The importance of these results in understanding the influence of phytophagy on predation rates of omnivorous predators is discussed

Selection of Macrolophus melanotoma between its main non-crop host plant (Dittrichia viscosa) and eggplant, pepper and tomato, in choice experiments

Στη μελέτη αυτή εξετάσθηκε η προτίμηση του αρπακτικού Macrolophus melanotoma (Costa) (=M. caliginosus Wagner) (Hemiptera: Miridae) μεταξύ του Dittrichia viscosa L. (W. Greuter) (Asteraceae), που αποτελεί το κύριο φυτό ξενιστή του, σε σχέση με τη μελιτζάνα, πιπεριά και τομάτα, καθώς και μεταξύ της μελιτζάνας, πιπεριάς και τομάτας. Τα πειράματα πραγματοποιήθηκαν σε κλωβούς όπου το αρπακτικό είχε τη δυνατότητα να επιλέξει μεταξύ δύο φυτών διαφορετικών ειδών. Σε κάθε επανάληψη, ένα ενήλικο του αρπακτικού ελευθερωνόταν είτε επί της βάσης του κλωβού μεταξύ των δύο φυτών είτε στα κορυφαία φύλλα του φυτού μελιτζάνας, πιπεριάς ή τομάτας. Η θέση του αρπακτικού καταγραφόταν μετά από 20min, 1, 2, and 24h από την ελευθέρωσή του στον κλωβό. Σύμφωνα με τα αποτελέσματα, το Μ. melanotoma έδειξε υψηλή προτίμηση για το φυτό από το οποίο προερχόταν, δηλαδή το D. viscosa, σε σχέση με το φυτό μελιτζάνας, πιπεριάς ή τομάτας. Μεταξύ των τριών σολανωδών φυτών είχε σχετικά μεγαλύτερη προτίμηση για τη μελιτζάνα. Επομένως, το M. melanotoma φάνηκε να μην προτιμά την τομάτα και την πιπεριά, όμως θα πρέπει να μελετηθεί περαιτέρω η δυνατότητά του να αποικίζει καλλιέργειες μελιτζάνας.The host plant selection of the predator Macrolophus melanotoma (Costa) (=M. caliginosus Wagner) (Hemiptera: Miridae) was studied between: i) its major non-crop host plant, Dittrichia viscosa L. (W. Greuter) (Asteraceae) and the solanaceous plants eggplant, pepper and tomato, and ii) between eggplant, pepper and tomato, in choice experiments. The experiments were performed in cages where two potted plants without prey were placed. In each replicate, an adult predator was released in the centre of the cage or on the solanaceous plant. The position of the released predator in each cage was recorded at intervals of 20min, 1, 2, and 24h after its introduction. The results showed that M. melanotoma had a high selection preference rate for its origin host plant (D. viscosa) irrespectively of the solanaceous plant that was present in the cage. The experiments investigating the relative preference of M. melanotoma when given access only to solanaceous plants revealed that it preferred eggplant at higher rates than pepper and tomato. These data indicate that M. melanotoma originating from D. viscosa patches might have a very low potential to colonize pepper or tomato crops in the open field. However, its potential to colonize eggplant crops should be further evaluated

Contribution to the ecological management of the seed chalcid wasp Eurytoma plotnikovi Nikol’skaya (Hymenoptera: Eurytomidae) in pistachio orchards

δε διατίθεται περίληψη στα ελληνικάAspects related to the management of the pistachio seed wasp Eurytoma plotnikovi Nikol’skaya (Hymenoptera: Eurytomidae), were investigated. E. plotnikovi has internal feeding habits. However, the external appearance of the fruits could be used to distinguish between infested and uninfested fruits, since fruits partly blackish or brownish and shriveled had higher infestation levels than those without any discolouration. The adult emergence from the fruits was completed within a short period of 12 days, from the middle until the end of May. This pest overwinters as larva inside the mummified fruits. The application of sanitation measures for the control of this pest was experimentally investigated. The results showed that no adults emerged from fruits that were buried in the soil but also from those that remained on the soil surface during winter. Thus, it seems that there is no need for burying them by tillage under the soil as it had been proposed. This result might be essential in the wider adoption of this method in the management of this pest

Contribution to the ecological management of the seed chalcid wasp Eurytoma plotnikovi Nikol’skaya (Hymenoptera: Eurytomidae) in pistachio orchards

δε διατίθεται περίληψη στα ελληνικάAspects related to the management of the pistachio seed wasp Eurytoma plotnikovi Nikol’skaya (Hymenoptera: Eurytomidae), were investigated. E. plotnikovi has internal feeding habits. However, the external appearance of the fruits could be used to distinguish between infested and uninfested fruits, since fruits partly blackish or brownish and shriveled had higher infestation levels than those without any discolouration. The adult emergence from the fruits was completed within a short period of 12 days, from the middle until the end of May. This pest overwinters as larva inside the mummified fruits. The application of sanitation measures for the control of this pest was experimentally investigated. The results showed that no adults emerged from fruits that were buried in the soil but also from those that remained on the soil surface during winter. Thus, it seems that there is no need for burying them by tillage under the soil as it had been proposed. This result might be essential in the wider adoption of this method in the management of this pest

Selection of Macrolophus melanotoma between its main non-crop host plant (Dittrichia viscosa) and eggplant, pepper and tomato, in choice experiments

Στη μελέτη αυτή εξετάσθηκε η προτίμηση του αρπακτικού Macrolophus melanotoma (Costa) (=M. caliginosus Wagner) (Hemiptera: Miridae) μεταξύ του Dittrichia viscosa L. (W. Greuter) (Asteraceae), που αποτελεί το κύριο φυτό ξενιστή του, σε σχέση με τη μελιτζάνα, πιπεριά και τομάτα, καθώς και μεταξύ της μελιτζάνας, πιπεριάς και τομάτας. Τα πειράματα πραγματοποιήθηκαν σε κλωβούς όπου το αρπακτικό είχε τη δυνατότητα να επιλέξει μεταξύ δύο φυτών διαφορετικών ειδών. Σε κάθε επανάληψη, ένα ενήλικο του αρπακτικού ελευθερωνόταν είτε επί της βάσης του κλωβού μεταξύ των δύο φυτών είτε στα κορυφαία φύλλα του φυτού μελιτζάνας, πιπεριάς ή τομάτας. Η θέση του αρπακτικού καταγραφόταν μετά από 20min, 1, 2, and 24h από την ελευθέρωσή του στον κλωβό. Σύμφωνα με τα αποτελέσματα, το Μ. melanotoma έδειξε υψηλή προτίμηση για το φυτό από το οποίο προερχόταν, δηλαδή το D. viscosa, σε σχέση με το φυτό μελιτζάνας, πιπεριάς ή τομάτας. Μεταξύ των τριών σολανωδών φυτών είχε σχετικά μεγαλύτερη προτίμηση για τη μελιτζάνα. Επομένως, το M. melanotoma φάνηκε να μην προτιμά την τομάτα και την πιπεριά, όμως θα πρέπει να μελετηθεί περαιτέρω η δυνατότητά του να αποικίζει καλλιέργειες μελιτζάνας.The host plant selection of the predator Macrolophus melanotoma (Costa) (=M. caliginosus Wagner) (Hemiptera: Miridae) was studied between: i) its major non-crop host plant, Dittrichia viscosa L. (W. Greuter) (Asteraceae) and the solanaceous plants eggplant, pepper and tomato, and ii) between eggplant, pepper and tomato, in choice experiments. The experiments were performed in cages where two potted plants without prey were placed. In each replicate, an adult predator was released in the centre of the cage or on the solanaceous plant. The position of the released predator in each cage was recorded at intervals of 20min, 1, 2, and 24h after its introduction. The results showed that M. melanotoma had a high selection preference rate for its origin host plant (D. viscosa) irrespectively of the solanaceous plant that was present in the cage. The experiments investigating the relative preference of M. melanotoma when given access only to solanaceous plants revealed that it preferred eggplant at higher rates than pepper and tomato. These data indicate that M. melanotoma originating from D. viscosa patches might have a very low potential to colonize pepper or tomato crops in the open field. However, its potential to colonize eggplant crops should be further evaluated

Recognizing recurrent neural networks (rRNN): Bayesian inference for recurrent neural networks

Recurrent neural networks (RNNs) are widely used in computational neuroscience and machine learning applications. In an RNN, each neuron computes its output as a nonlinear function of its integrated input. While the importance of RNNs, especially as models of brain processing, is undisputed, it is also widely acknowledged that the computations in standard RNN models may be an over-simplification of what real neuronal networks compute. Here, we suggest that the RNN approach may be made both neurobiologically more plausible and computationally more powerful by its fusion with Bayesian inference techniques for nonlinear dynamical systems. In this scheme, we use an RNN as a generative model of dynamic input caused by the environment, e.g. of speech or kinematics. Given this generative RNN model, we derive Bayesian update equations that can decode its output. Critically, these updates define a 'recognizing RNN' (rRNN), in which neurons compute and exchange prediction and prediction error messages. The rRNN has several desirable features that a conventional RNN does not have, for example, fast decoding of dynamic stimuli and robustness to initial conditions and noise. Furthermore, it implements a predictive coding scheme for dynamic inputs. We suggest that the Bayesian inversion of recurrent neural networks may be useful both as a model of brain function and as a machine learning tool. We illustrate the use of the rRNN by an application to the online decoding (i.e. recognition) of human kinematics