bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eggsac development rates and phenology of agrobiont linyphiid spiders in relation to temperature
Authors: Thorbek P. , Sunderland K.D. , Topping C.J. 
Published: October 2003

AbstractSpider densities are often low after winter in annual crops, and crop management decimates spider populations several times per year. Population recovery rates and phenology depend on reproductive and development rates, which in turn are driven largely by temperature. We aimed to quantify the relationships between eggsac development rates and temperature in order to understand the relative value of different linyphiid species for the biological control of agricultural pests. Female adults of nine linyphiid species were collected from winter wheat in the UK over 3 years; Bathyphantes gracilis (Blackwall), Erigone atra (Blackwall), Erigone dentipalpis (Wider), Erigone promiscua O.P.‐Cambridge), Tenuiphantes tenuis (Blackwall) [formerly Lepthyphantes tenuis (Blackwall)], Meioneta rurestris (C.L. Koch), Oedothorax apicatus (Blackwall), Oedothorax fuscus (Blackwall), and Oedothorax retusus (Westring). These are agrobiont species that are dominant in agroecosystems. We tested how well development in the field can be predicted on the basis of laboratory experiments. We also built a simple phenology simulation model to test whether spider phenology in the field can be predicted by a general knowledge of the relationship between temperature and development rate. The relationships between temperature and development rates of eggsacs were not linear as described by a day‐degree model, but exponential as described by a biophysical model. Duration of the eggsac development period in the field was predicted accurately from laboratory experiments. We only found minor differences between development thresholds of eggsacs at constant temperatures compared with fluctuating temperatures. The phenology model predicted the phenology of L. tenuis and E. atra well, but the number of generations predicted for O. fuscus was not realised in the field. This suggests that development of this species may be affected by factors other than temperature. The methods used here could also be applied to other natural enemies, to determine whether their thermal biology is conducive to a role as biocontrol agents in disturbed agricultural systems.
Trap cropping to control Delia radicum populations in cruciferous crops: first results and future applications
Authors: Rousse P. , Fournet S. , Porteneuve C. , Brunel E. 
Published: October 2003

AbstractThis study evaluates the efficacy of a new approach to the control of Delia radicum populations. We suggest associating the primary crop with a trap crop that is expected to be more attractive to D. radicum females and to attract and sustain their natural enemies such as Aleochara bilineata and A. bipustulata. Various cruciferous species were compared in terms of their preference for adult D. radicum females, and performance, as estimated by larval survival. Laboratory results were complemented by field experiments in which the selected trap crops were associated with broccoli plants. The following results were obtained. Of the six different cruciferous plant species tested, Delia radicum females showed a strong preference for Chinese cabbage, with turnip also being attractive. Following the laboratory results, turnip was chosen as a trap crop because it was easier to cultivate and presented good preference and performance. In the field experiments, Aleochara adults were present in higher numbers in plots associated with turnips than in pure broccoli plots. The presence of Aleochara adults in plots with turnips improved plant protection; as fewer broccoli plants were attacked, the attacked plants were less severely damaged, and more D. radicum pupae were parasitised than in pure broccoli plots. Delia radicum females did not lay fewer eggs on broccoli plants associated with turnips. Moreover, protection and parasitism were more effective in the rows closest to the central row of turnips, suggesting that Aleochara adults limit their activity to its immediate vicinity.
Effect of optical brighteners on the insecticidal activity of a nucleopolyhedrovirus in three instars of Spodoptera frugiperda
Authors: Martínez Ana‐Mabel , Simón Oihane , Williams Trevor , Caballero Primitivo 
Published: October 2003

AbstractCertain optical brighteners are effective UV protectants, and can improve the insecticidal activity of baculoviruses. We evaluated the effect of 10 optical brighteners, from four chemically different groups, on the insecticidal activity of a nucleopolyhedrovirus (SfMNPV) in third instar Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). The most effective optical brighteners were Blankophor BBH and Calcofluor M2R, both of which are stilbenes. The distyryl‐biphenyl derivative, Tinopal CBS, had no effect, whereas the stilbenes, Blankophor CLE and Leucophor SAC and the styryl‐benzenic derivative, Blankophor ER, resulted in a decrease in virus induced mortality compared to larvae infected with SfMNPV alone. Mixtures of SfMNPV + 0.1% Calcofluor M2R had relative potencies of 2.7, 6.5, and 61.6 in the second, third, and fourth instars, respectively. The mean time to death differed with instar, but was not affected by the addition of 0.1% Calcofluor M2R. Analysis of published studies indicated that the concentration of Calcofluor M2R‐related stilbenes was positively correlated with the relative potency observed in mixtures with homologous NPVs. The average magnitude of optical brightener activity did not differ significantly between early instars of 10 species of Lepidoptera. We conclude that virus formulations containing optical brighteners may be valuable for control of late instar lepidopteran pests.
Effect of expected offspring survival probability on host selection in a solitary parasitoid
Authors: Goubault Marlène , Plantegenest Manuel , Poinsot Denis , Cortesero Anne Marie 
Published: October 2003

AbstractOptimal Foraging Theory predicts that parasitoid females should optimize their host selection to maximize their lifetime fitness gain and parasitize the most profitable hosts. In particular, in solitary parasitoids, females should avoid superparasitism, at least when sufficient unparasitized hosts are available. However, when unparasitized hosts are scarce, they should prefer, among already parasitized hosts, those that provide the best survival probability to their progeny, which depends on the age and the developmental stage of the first parasitoid.To test this hypothesis in a solitary ectoparasitoid, Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae), we first assessed the survival probability of a second parasitoid according to the time elapsed since initial parasitism. We then analyzed the female selection behavior in patches containing a mixture of hosts parasitized over various time intervals.Our results showed that the older the opponent larva was, the lower the survival probability of the second parasitoid was. However, when the first individual had reached the prepupal stage, both individuals could complete their development. At this stage, the survival probability of the second parasitoid was surprisingly high but such individuals were reduced in size.Our study also showed that host acceptance by females was strongly correlated with the survival probability of their progeny when the first parasitoid was from 0 to less than 10 days‐old. When the first parasitoid had reached the prepupal stage, females usually rejected these hosts, although the survival probability of the offspring was quite high. This discordance between female host selection behavior and progeny survival probability is discussed.
Effects of an optical brightener and an abrasive on iridescent virus infection and development of Aedes aegypti
Authors: Marina Carlos F. , Arredondo‐Jiménez Juan I. , Ibarra Jorge E. , Fernández‐Salas Ildefonso , Williams Trevor 
Published: October 2003

AbstractThe insecticidal properties of certain entomopathogenic viruses can be greatly improved in mixtures with substances that affect the integrity of the insect peritrophic membrane, particularly optical brighteners. We aimed to determine the effect of an optical brightener, Blankophor BBH, and an abrasive compound, silicon carbide, alone and in mixtures, on the prevalence of patent and covert infection of Aedes aegypti (L.) (Diptera: Culicidae) by Invertebrate iridescent virus 6 (IIV‐6) (Iridoviridae). The prevalence of patent infection by IIV‐6 was < 1.5% in all treatments involving virus. Contrary to predictions, there were significantly fewer patent infections in virus treatments involving Blankophor with or without silicon carbide compared with controls. Covert infection of adults detected by insect bioassay was between 6.7 and 12.2%, although no significant differences were observed between treatments. Exposure to IIV‐6 alone or silicon carbide alone did not significantly increase larval mortality compared to the controls, whereas exposure to Blankophor alone, or in any combination with IIV‐6 or silicon carbide, clearly increased larval mortality. These effects did not carry‐over to the pupal stage. Adult females emerged ∼1.5 days later than males. Compared to control insects, female development rate was extended by 11.4 and 12.6% in the treatments involving IIV‐6 alone and silicon carbide alone, respectively. The sex ratio at adult emergence did not differ significantly between control insects and those of other treatments. These results support the hypothesis that the gut is unlikely to represent the principal point of infection of mosquito larvae by iridescent viruses.
Freud and Jung: an incomplete encounter1
Authors: McFarland Solomon Hester 
Published: October 2003

Abstract:  The author discusses the bases of the close, personal and professional relationship between Freud and Jung, and conjectures that the eventual schism between them was the result of the different profound psychological needs that each had for the other. Because of his identification with the psychoanalytic enquiry, particularly as it was based in large measure on his own self analysis, Freud looked to Jung as a collaborator who would not deviate from the principles at the basis of psychoanalysis, seeking psychoanalysis’ acceptance within the established scientific community. From Jung's point of view, Freud fulfilled the role of a respected father figure who, Jung hoped, would grant him the autonomy and freedom to pursue his own scientific enquiry, based on Freud's ideas, but which he would revise according to his own researches. These led Jung to certain revisions and additions, such as the nature and function of the libido, the broadening of the idea of the complex (as in the Oedipus complex) to include a number of universal, archetypal themes, and the elaboration of the concept of the self.During the years of their relationship, they shared a mutual psychological support which was deeply important to each, based on reciprocal love and respect but also on a fantasy that each would be able to supply to the other a key capacity that the other lacked. Jung was able to offer important scientific verifications of a number of psychoanalytic notions via the Word Association Test, such as the concept of repression, of the complex, including the Oedipus complex, and the proof of the existence of the unconscious. However, neither could supply to the other what each looked for in the other at the psychological level.The final breakdown and rupture in their relationship was caused by their theoretical differences and by the fact that they became bitter competitors in a race to publish treatises on the nature and origins of spirituality and religion. It has left in its wake the implicit traces of discord and misapprehension which have characterized much of subsequent professional relationships between the two traditions.
Attending to the General Interest: New Mechanisms for Mediating between the Individual, Collective and General Interest in Québec
Authors: Bernier Luc , Bouchard Marie , Lévesque Benoît 
Published: October 2003

AbstractWe develop an approach to studying new business governance models and we illustrate how these models take the general interest into account. We outline the main prevailing trends, in the context of the Québec model of development, and discuss the new conceptions of the state and of its role in governance. As a result of this, organizations and institutions are playing a new role in the pursuit of the general interest, which we examine using the ‘Solidarity Fund’ of the Fédération des travailleurs et travailleuses du Québec (FTQ). We suggest that a partnership‐based governance model may help support the emergence of a new mixed economy that weds the general interest with individual and collective interests in an original way.
Residual Claims in Co‐operatives: Design Issues
Authors: Srinivasan R. , Phansalkar S.J. 
Published: October 2003

AbstractThis paper examines issues in the design of a co‐operative member's contractual relationship with the other agents (including the remaining members) using organizational economics. The paper assumes that the central defining characteristic of a co‐op is the residual claim specification. Agency theory identifies certain inherent problems of the co‐op form, the horizon problem, common property problem, and non‐transferability. Non‐transferability both reduces the incentive to monitor and imposes limits on portfolio diversification. This paper argues that features such as claim incompleteness and non‐transferability are not inherent to the co‐op but may be transaction‐cost economizing. The paper also argues that the pre‐emptive payoff feature by which the residual claimants (the co‐op members) also become fixed payoff agents can affect the risk of other agents, and is an important determinant of co‐op risk. A co‐op may have more than one potential residual claim base. Five generic design choices are available for handling possible multiple claim bases: battleground, pre‐specified allocation, limited return, alignment, and fixed payoff. The paper uses the design of residual claims in sugar co‐ops to show how a co‐op can partly overcome some of the problems identified by agency theory. This illustration ties together the issues of claim incompleteness and non‐transferability, pre‐emptive payoff, and multiple claim bases.
Production et rationalisation des intermédiaires financiers: Leçons à tirer de l’expérience des Caisses Populaires Acadiennes
Authors: Leclerc André , Fortin Mario 
Published: October 2003

ResumeNous mesurons à l’aide du DEA (Data Envelopment Analysis) l’efficacité des caisses populaires acadiennes en utilisant la valeur des produits d’intermédiation ainsi que le nombre de transactions réalisées par chaque caisse entre 1997 et 2000, au moment où un important programme de fusions et de réingénierie financière était mis en place. Cette analyse permet d’établir plusieurs résultats. Tout d’abord, l’inclusion des produits transactionnels réduit environ de moitié l’inefficacité technique et économique par rapport à l’inefficacité obtenue lorsque l’output des caisses est limité seulement aux produits transactionnels. Un algorithme d’auto‐amorçage permet de vérifier que ce résultat est statistiquement significatif. Ensuite, nous montrons que le programme de fusions a touché surtout les caisses moins efficaces et a permis d’augmenter de façon importante leur efficacité grâce à une baisse du nombre d’employés en équivalent temps complet. Finalement, nous montrons que d’importants progrès technologiques ont été réalisés entre 1997 et 2000 en raison de l’accroissement du nombre de transactions informatisées. Des gains additionnels de productivité ont été rendus possible grâce à l’amélioration de l’efficacité des caisses ayant participéà une fusion tandis que les caisses n’ayant pas fusionné, bien que plus efficaces au départ que les autres, n’ont pas réalisé de gains d’efficacité.
Models with Errors due to Misreported Measurements
Authors: Henderson Brent , Jarrett Richard 
Published: October 2003

SummaryMeasurement error and misclassification models feature prominently in the literature. This paper describes misreporting error, which can be considered to fall somewhere between these two broad types of model.Misreporting is concerned with situations where a continuous random variable X is measured with error and only reported as the discrete random variable Z. Data grouping or rounding are the simplest examples of this, but more generally X may be reported as a value z of Z which refers to a different interval from the one in which X lies. The paper discusses a method for handling misreported data and draws links with measurement error and misclassification models.A motivating example is considered from a prenatal Down's syndrome screening, where the gestational age at which mothers present for screening is a true continuous variable but is misreported because it is only ever observed as a discrete whole number of weeks which may in fact be in error. The implications this misreporting might have for the screening are investigated.
Non‐Parametric Testing of Conditional Variance Functions in Time Series
Authors: Laïb Naâmane 
Published: October 2003

SummaryThis paper proposes a non‐parametric test for examining hypotheses about variance functions under stationarity and ergodicity conditions. Special cases of nonlinear time series models are studied, and it is found that under mild conditions the test is consistent. Its power is examined in a simulation study.
A Lack‐of‐Fit Test for Heteroscedastic Regression Models via Cosine‐Series Smoothers
Authors: Li Chin‐Shang 
Published: October 2003

SummaryIn this paper, a test is derived to assess the validity of heteroscedastic nonlinear regression models by a non‐parametric cosine regression method. For order selection, the paper proposes a data‐driven method that uses the parametric null model optimal order. This method yields a test that is asymptotically normally distributed under the null hypothesis and is consistent against any fixed alternative. Simulation studies that test the lack of fit of a generalized linear model are conducted to compare the performance of the proposed test with that of an existing non‐parametric kernel test. A dataset of esterase levels is used to demonstrate the proposed method in practice.
Identifying Children's Peer Social Networks in School Classrooms: Links Between Peer Reports and Observed Interactions
Authors: Gest Scott D. , Farmer Thomas W. , Cairns Beverley D. , Xie Hongling 
Published: October 2003

AbstractLinks between peer reports of social cluster membership and observed classroom interactions were examined in a sample of 72 children in 4th grade and 7th grade. All participating children in each classroom identified as many social clusters in the classroom as they could recall. Using the social‐cognitive map (SCM) procedure, these individual reports were aggregated to summarize the number of times a given child was nominated as being in the same social cluster as each of his or her classmates (i.e., a co‐nomination profile) and to identify the classmates in each child's social cluster. Extensive classroom observations allowed for a parallel summary of the number of times a given child was observed to interact with each of his or her classmates (i.e., an interaction profile). Results indicated that correlations between conomination profiles and interaction profiles were positive and statistically reliable. Children were observed to interact with members of their SCM‐identified social cluster at a rate four times higher than with other same‐sex classmates. These effects did not vary reliably by grade, sex or aggressive risk status.
Relational Aggression, Relational Victimization, and Language Development in Preschoolers
Authors: Bonica Cheryl , Arnold David H. , Fisher Paige H. , Zeljo Alexandra , Yershova Kseniya 
Published: October 2003

AbstractWe investigated language development, relational aggression, and relational victimization in ethnically, socioeconomically diverse preschoolers. Relational aggression was positively related to language development. Girls were more relationally aggressive than boys, and higher‐socioeconomic status (SES) children were more relationally aggressive and victimized than lower‐SES children. Neither gender nor SES conclusively moderated the relation between language and relational aggression, though some findings suggest the possibility of stronger relations among boys and lower‐SES children. Teachers agreed on ratings of relational aggression and relational victimization to a moderate extent.
The Effect of Gender Context on Children's Social Behavior in a Limited Resource Situation: An Observational Study
Authors: Green Vanessa A. , Cillessen Antonius H. N. , Berthelsen Donna , Irving Kym , Catherwood Di 
Published: October 2003

AbstractKnowing when to compete and when to cooperate to maximize opportunities for equal access to activities and materials in groups is critical to children's social and cognitive development. The present study examined the individual (gender, social competence) and contextual factors (gender context) that may determine why some children are more successful than others. One hundred and fifty‐six children (M age=6.5 years) were divided into 39 groups of four and videotaped while engaged in a task that required them to cooperate in order to view cartoons. Children within all groups were unfamiliar to one another. Groups varied in gender composition (all girls, all boys, or mixed‐sex) and social competence (high vs. low). Group composition by gender interaction effects were found. Girls were most successful at gaining viewing time in same‐sex groups, and least successful in mixed‐sex groups. Conversely, boys were least successful in same‐sex groups and most successful in mixed‐sex groups. Similar results were also found at the group level of analysis; however, the way in which the resources were distributed differed as a function of group type. Same‐sex girl groups were inequitable but efficient whereas same‐sex boy groups were more equitable than mixed groups but inefficient compared to same‐sex girl groups. Social competence did not influence children's behavior. The findings from the present study highlight the effect of gender context on cooperation and competition and the relevance of adopting an unfamiliar peer paradigm when investigating children's social behavior.
An Extension of the Structural Change Model to International Economic Relations
Authors: Araujo Ricardo Azevedo , Teixeira Joanílio Rodolpho 
Published: October 2003

ABSTRACTIn this paper Pasinetti's model of structural economic dynamics (1981) is extended to consider international economic relations. Conditions for full employment, full expenditure of income and equilibrium of the trade balance are established for an open economy that requires capital goods to produce final commodities. Analytical results concerning the benefits from free trade and international learning are formally studied. In addition, static and dynamic aspects of the ‘principle of comparative cost advantage’ are analysed considering the determinants of the specialization level.