bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of high frequency intensity oscillations at RESEDA using the CASCADE detector
Authors: Häussler W. , Böni P. , Klein M. , Schmidt C. J. , Schmidt U. , Groitl F. , Kindervater J.
Published: April 2011

We have explored the technological potential of combining neutron resonance spin echo (NRSE) with the time-of-flight method in quasielastic neutron scattering (QENS) experiments. For these test measurements at the new NRSE instrument RESEDA (FRM II, Munich), we have employed CASCADE, one of the fastest neutron detectors in the world, developed at the University of Heidelberg. Conventionally, scintillation detectors are used, in order to detect neutron intensities with high time resolution. In contrast, we used the new CASCADE detector converting neutrons in thin 10B layers being capable of resolving neutron intensity modulations up to the megahertz regime. This fast detector allows us to abandon the last resonance flip coil of a standard NRSE setup. The classical spin echo signal is replaced by a time-modulated signal. In this setup, fast intensity modulations are present at the detector position. In order to demonstrate, that NRSE-CASCADE operates well up to detector frequencies of 10 MHz, we performed elastic polarization test measurements on a standard sample. The CASCADE detector is a multidetector accumulating counts in 128 × 128 pixels on a surface of 200 mm × 200 mm. We have analyzed the signal in 600 pixels, providing information about the spin phase reaching the detector and about the resolution function of this new variant tested at RESEDA.
Impact of field-induced quantum confinement in tunneling field-effect devices
Authors: Vandenberghe William G. , Sorée Bart , Magnus Wim , Groeseneken Guido , Fischetti Massimo V.
Published: April 2011

Being the working principle of a tunnel field-effect transistor, band-to-band tunneling is given a rigorous quantum mechanical treatment to incorporate confinement effects, multiple electron and hole valleys, and interactions with phonons. The model reveals that the strong band bending near the gate dielectric, required to create short tunnel paths, results in quantization of the energy bands. Comparison with semiclassical models reveals a big shift in the onset of tunneling. The effective mass difference of the distinct valleys is found to reduce the subthreshold swing steepness.
Spontaneous formation of highly regular superlattice structure in InGaN epilayers grown by molecular beam epitaxy
Authors: Wu Z. H. , Kawai Y. , Fang Y.-Y. , Chen C. Q. , Kondo H. , Hori M. , Honda Y. , Yamaguchi M. , Amano H.
Published: April 2011

In this letter, we have investigated the structural properties of thick InGaN layers grown on GaN by plasma-assisted molecular beam epitaxy, using two growth rates of 1.0 and 3.6 Å/s. A highly regular superlattice (SL) structure is found to be spontaneously formed in the film grown at 3.6 Å/s but not in the film grown at 1.0 Å/s. The faster grown film also exhibits superior structural quality, which could be due to the surface roughness suppression caused by kinetic limitation, and the inhibition of the Frank–Read dislocation generation mechanism within the spontaneously formed SL structure.
Semiclassical approach to plasmon–electron coupling and Landau damping of surface plasmons
Authors: Gao Yi , Yuan Zhe , Gao Shiwu
Published: April 2011

A semiclassical model is developed to describe plasmon–electron coupling and electronic damping of surface plasmons. It is compared with the ab initio linear response calculations for metallic thin films in the jellium approximation and for a realistic crystalline Mg(0001) surface. The semiclassical model is able to reproduce the quantum oscillations of plasmon linewidth, which was obtained in the previous ab initio calculations. In addition, state-resolved analysis reveals the origin of these oscillations, which result from superposition of the short-period oscillations of individual electron–hole pair transitions. The semiclassical model is further applied to a crystalline Mg(0001) surface, where linewidth dispersion of the surface plasmon is calculated and shows good agreement with earlier ab initio calculation and experiment. Our results suggest that this semiclassical approach is quite promising for the quantitative description of plasmon–electron coupling and associated processes such as surface-enhanced Raman scattering, light emission, and fluorescence.
Japanese children's amae and mothers’ attachment status as assessed by the Adult Attachment Interview
Authors: Behrens Kazuko Y. , Kondo‐Ikemura Kiyomi
Published: April 2011

This study explored whether Japanese mothers’ attachment status, as judged by the Adult Attachment Interview (AAI), would affect the way they perceive their child's amae. Amae, an indigenous Japanese concept of relatedness, has troubled, fascinated, and even mystified scholars across disciplines. In particular, amae has been sometimes misconstrued as the insecure–ambivalent pattern of attachment due to their apparent behavioral similarities. In an attempt to explore an empirical link between attachment and amae, Japanese mothers’ (N = 47) views on their six‐year‐olds’ amae were examined based on a brief amae questionnaire, given following the standard AAI. Mothers generally reported their child's amae similarly for questions of frequency (e.g., how often your child exhibits amae behaviors) or situations (e.g., in what circumstances your child most often engages in amae). However, a difference emerged when mothers’ free descriptions of their child's amae were examined for the content quality, categorized, and analyzed against their secure/insecure attachment statuses. Secure mothers depicted their child's amae as being more affective, thus more welcoming, whereas insecure mothers depicted their child's typical amae as being more instrumental or manipulative, thus perhaps less welcoming. Japanese mothers’ current states of mind with respect to attachment do appear to affect the way they perceive their child's typical amae. Future research on attachment and amae is discussed.
Perturbations of dark solitons
Authors: Ablowitz M. J. , Nixon S. D. , Horikis T. P. , Frantzeskakis D. J.
Published: April 2011

A direct perturbation method for approximating dark soliton solutions of the nonlinear Schrödinger (NLS) equation under the influence of perturbations is presented. The problem is broken into an inner region, where the core of the soliton resides, and an outer region, which evolves independently of the soliton. It is shown that a shelf develops around the soliton that propagates with speed determined by the background intensity. Integral relations obtained from the conservation laws of the NLS equation are used to determine the properties of the shelf. The analysis is developed for both constant and slowly evolving backgrounds. A number of problems are investigated, including linear and nonlinear damping type perturbations.
Maximum-likelihood estimation of damage location in guided-wave structural health monitoring
Authors: Flynn Eric B. , Todd Michael D. , Wilcox Paul D. , Drinkwater Bruce W. , Croxford Anthony J.
Published: April 2011

This paper describes the formulation of a maximum-likelihood estimate of damage location for guided-wave structural health monitoring (GWSHM) using a minimally informed, Rayleigh-based statistical model of scattered wave measurements. Also introduced are two statistics-based methods for evaluating localization performance: the localization probability density function estimate and the localizer operating characteristic curve. Using an ensemble of measurements from an instrumented plate with stiffening stringers, the statistical performance of the so-called Rayleigh maximum-likelihood estimate (RMLE) is compared with that of seven previously reported localization methods. The RMLE proves superior in all test cases, and is particularly effective in localizing damage using very sparse arrays consisting of as few as three transducers. The probabilistic basis used for modelling the complicated wave scattering behaviour makes the algorithm especially suited for localizing damage in complicated structures, with the potential for improved performance with increasing structure complexity.
Analysis of Two in Planta Expressed LysM Effector Homologs from the FungusMycosphaerella graminicolaReveals Novel Functional Properties and Varying Contributions to Virulence on Wheat
Authors: Marshall Rosalind , Kombrink Anja , Motteram Juliet , Loza-Reyes Elisa , Lucas John , Hammond-Kosack Kim E. , Thomma Bart P.H.J. , Rudd Jason J.
Published: April 2011

Secreted effector proteins enable plant pathogenic fungi to manipulate host defenses for successful infection. Mycosphaerella graminicola causes Septoria tritici blotch disease of wheat (Triticum aestivum) leaves. Leaf infection involves a long (approximately 7 d) period of symptomless intercellular colonization prior to the appearance of necrotic disease lesions. Therefore, M. graminicola is considered as a hemibiotrophic (or necrotrophic) pathogen. Here, we describe the molecular and functional characterization of M. graminicola homologs of Ecp6 (for extracellular protein 6), the Lysin (LysM) domain-containing effector from the biotrophic tomato (Solanum lycopersicum) leaf mold fungus Cladosporium fulvum, which interferes with chitin-triggered immunity in plants. Three LysM effector homologs are present in the M. graminicola genome, referred to as Mg3LysM, Mg1LysM, and MgxLysM. Mg3LysM and Mg1LysM genes were strongly transcriptionally up-regulated specifically during symptomless leaf infection. Both proteins bind chitin; however, only Mg3LysM blocked the elicitation of chitin-induced plant defenses. In contrast to C. fulvum Ecp6, both Mg1LysM and Mg3LysM also protected fungal hyphae against plant-derived hydrolytic enzymes, and both genes show significantly more nucleotide polymorphism giving rise to nonsynonymous amino acid changes. While Mg1LysM deletion mutant strains of M. graminicola were fully pathogenic toward wheat leaves, Mg3LysM mutant strains were severely impaired in leaf colonization, did not trigger lesion formation, and were unable to undergo asexual sporulation. This virulence defect correlated with more rapid and pronounced expression of wheat defense genes during the symptomless phase of leaf colonization. These data highlight different functions for MgLysM effector homologs during plant infection, including novel activities that distinguish these proteins from C. fulvum Ecp6.
ITP: a historical perspective
Authors: Stasi Roberto , Newland Adrian C.
Published: April 2011

A clinical syndrome of bleeding and purpura consistent with a diagnosis of immune thrombocytopenia (ITP) was described by Werlhof long before platelets were identified as the cellular component of blood playing an essential role in primary haemostasis. Although a role for the spleen was suggested nearly a century ago, the pathophysiology of ITP has remained elusive for many decades. During this time Werlhof’s disease was renamed idiopathic thrombocytopenic purpura, from which the acronym ITP originally derives. The second half of the 20th century brought recognition of the autoimmune components of ITP, and hence the need for a new standard nomenclature, which has recently been accepted. ITP currently stands for Immune Thrombocytopenia, a name that more appropriately reflects the low platelet count rather than purpura as the main feature of the disease, as well as to defining its underlying nature. Advances in our knowledge of the disease have paralleled the availability of new therapeutic agents, and we are now entering an era of pathophysiologically‐based treatment options.
Disseminated Mycobacterium kansasii infection with hepatic abscesses in a renal transplant recipient
Authors: Kaur P. , Fishman J.A. , Misdraji J. , Varma M.C. , Kotton C.N.
Published: April 2011

P. Kaur, J.A. Fishman, J. Misdraji, M.C. Varma, C.N. Kotton. Disseminated Mycobacterium kansasii infection with hepatic abscesses in a renal transplant recipient Transpl Infect Dis 2011: 13: 531–535. All rights reserved

Abstract: Mycobacterium kansasii is the second most frequent cause of non‐tuberculous mycobacterial disease in the United States after Mycobacterium avium complex. While primarily it is a pulmonary disease, extrapulmonary manifestations are common. This case report describes a recent renal transplant recipient with disseminated M. kansasii infection presenting with hepatic abscesses, with discussion of clinical management issues and strategies, and a review of the literature.
Understanding Student Attempts to Find a Line of Fit
Authors: Sorto M. Alejandra , White Alexander , Lesser Lawrence M.
Published: April 2011

The least squares method of fitting a line is not one that naturally occurs to students. We present three tasks to understand student views on how lines may be fit.
Hypoxia‐inducible factor pathway activation in restless legs syndrome patients
Authors: Patton S. M. , Ponnuru P. , Snyder A. M. , Podskalny G. D. , Connor J. R.
Published: April 2011

Background and purpose:  These studies tested the hypothesis that hypoxia inducible factor‐1α (HIF‐1α) pathway activation occurs in substantia nigra neurons and brain microvasculature in patients with restless legs syndrome.

Methods:  Immunohistochemical analyses of substantia nigra tissue from six RLS and six control subjects were analyzed for HIF‐1α, neuronal nitric oxide synthase (nNOS) and nitrotyrosine immunoreactivity. Microvessel lysates were obtained from cortex tissue from four RLS and four control subjects and the lysates were quantified for HIF‐2α and vascular endothelial growth factor (VEGF) expression using immunoblot analyses. HIF‐1α activation of peripheral blood monocyte cells (PBMCs) (14 RLS and 9 control) was determined through immunoblot analysis of PBMC lysates for EPO.

Results:  HIF‐1α immunoreactivity in substantia nigra neurons was significantly increased in five of six RLS patients as compared with controls. In addition, nNOS and nitrotyrosine expression are up‐regulated in the substantia nigra of four of six RLS patients as compared with controls. HIF‐2α and VEGF expression are significantly up‐regulated in the microvasculature lysates from four RLS cortical brain tissue as compared with controls. Erythropoietin levels are significantly increased in RLS PBMCs.

Conclusions:  These results demonstrate that the hypoxia pathway is activated in multiple cell types in individuals with RLS. Increased nNOS and nitrotyrosine suggests that nitric oxide is involved in the activation. Activation of the hypoxia pathway can result from or contribute to cellular iron deficiency. These observations suggest a novel direction to explore in RLS that is tied to the iron deficiency model but better explains the findings in postmortem studies.
Overconfidence Among Professional Investors: Evidence from Mutual Fund Managers
Authors: Puetz Alexander , Ruenzi Stefan
Published: April 2011

Abstract:  We examine overconfidence among equity mutual fund managers. While overconfidence has been extensively documented among retail investors, evidence from professional investors is scarce. Consistent with theories of overconfidence, we find that fund managers trade more after good past performance. The higher trading activity after good performance is driven by individual portfolio performance, while the market performance has no significant impact. We rule out some alternative explanations for our results like increased trading as a response to tournament incentives, as a response to inflows, or as a rational reaction due to managerial learning about abilities.
Negotiations about helpfulness – the relationship between formal and informal care in home care arrangements
Authors: Büscher Andreas , Astedt‐Kurki Päivi , Paavilainen Eija , Schnepp Wilfried
Published: April 2011

Scand J Caring Sci; 2011; 25; 706–715

Negotiations about helpfulness – the relationship between formal and informal care in home care arrangements

Background:  Informal caregiving by family members is the most common way of caring for sick people at home. However, the number of care arrangements, in which both formal (nurses) and informal (family members) caregivers are involved, is considerable and increasing. Despite implicit assumptions in research that the involvement of nurses in home care arrangements is inherently beneficial, there is evidence that their involvement may have a destabilising effect.

Aims:  The purpose of this study was to investigate the relationship between nurses and family caregivers and its impact on the actual care that is provided.

Method:  Eighty‐eight interviews with family caregivers (n = 57) and nurses (n = 31) were conducted in Germany and analysed according to the Grounded Theory methodology.

Findings:  The relationship between formal and informal care is an encounter of two quite different perspectives that is focused on a negotiation process about caregiving work and the helpfulness of the actions taken and the interventions used. For family caregivers, it is determined by the goal of facilitating work and care for their sick family member. The nurses’ work is characterised by a process of shaping different realities in different homes. The results reveal the processes that lead to the involvement of nurses into home care arrangements and offer a deeper understanding of the negotiation processes between formal and informal caregivers.

Conclusions:  To provide sufficient support in home care, nurses need the ability to engage in negotiation processes that take the whole home care arrangement into account. Developmental work is needed to design services that are helpful for family caregivers.
International volunteering and development: global citizenship and neoliberal professionalisation today
Authors: Baillie Smith Matt , Laurie Nina
Published: April 2011

International volunteering occupies a popular place in contemporary UK public imaginations. It is supported by a range of stakeholders, including the state, the corporate sector and non‐government organisations (NGOs), which increasingly share a narrative emphasising international volunteering’s capacity to develop volunteers whose impacts on global equity or their professional identities emerge on their return as much as during their stay overseas. This paper explores discourses and practices of citizenship, professionalisation and partnership as they produce and are produced through contemporary international volunteering. We do this through interrogating the overlapping genealogies of international volunteering and development. Our analysis explores the ways in which international volunteering seems to both exemplify neoliberal ideas of individual autonomy, improvement and responsibility and at the same time allies itself to notions of collective global citizenship, solidarity, development and activism. To illustrate our argument we examine two sets of volunteering partnerships, those that support the Department for International Development’s £10 million, 3‐year programme focused on sending young, British disadvantaged people as international volunteers, and the corporate citizenship volunteer programmes supported by VSO and the international consulting firm, Accenture. Interrogating contemporary state, corporate and civil society promotion of international volunteering allows us to examine how notions of professionalisation and global and neoliberal citizenship are produced through development imaginaries, and are negotiated and constructed among and by new volunteering populations and sectors at a moment when, particularly due to the credit crunch, economic and career futures are fragile and uncertain.
The Design of Bonded Bimaterial Lattices that Combine Low Thermal Expansion with High Stiffness
Authors: Berger Jonathan , Mercer Chris , McMeeking Robert M. , Evans Anthony G.
Published: April 2011

In engineered systems where thermal strains and stresses are limiting, the ability to tailor the thermal expansion of the constituent materials independently from other properties is desirable. It is possible to combine two materials and space in such a way that the net coefficient of thermal expansion (CTE) of the structure is significantly different from the constituents, including the possibility of zero and negative thermal expansion. Bimaterial lattices that combine low, negative, or an otherwise tailored CTE with high stiffness, when carefully designed, have theoretical properties that are unmatched by other known material systems. Of known lattice configurations with tailorable CTE, only one geometry, a pin‐jointed lattice, has been shown to be stretch dominated and thus capable of having stiffness that approaches its theoretical upper bound. A related lattice with bonded joints, more amenable to fabrication, is developed that has a stiffness and CTE similar to the pinned structure. Analytical models for this rigid‐jointed lattice's CTE and stiffness are developed and compared successfully with numerical results. A near space‐filling, negative thermal expansion version of this lattice is devised and fabricated from titanium and aluminum. CTE measurements on this lattice are made and are well predicted by the analytical and numerical models. These insights guide the design of a family of bonded lattices with low areal density, low or negative CTE, and high stiffness to density ratio. Such lattices are shown to have a thermomechanical response that converges on pin‐jointed behavior when the lattice elements are long and slender.
HOST PLANT SELECTION IN THE COLORADO BEETLE LARVA
Authors: DE WILDE J.
Published: April 2011

In the food finding behaviour of the Colorado beetle larva, random searching and random biting are two apparently spontaneous behaviour elements belonging to different motor systems. Locomotion is directed by light and by host odour, biting is slightly inhibited by indifferent substrates like glass and filter paper. Initiation and maintenance of feeding are partly dependent upon different stimuli, as shown by the behaviour of the larva on Solanum demissum Lindl. Substances inhibiting the ingestion of food do not necessarily interfere with locomotory responses causing the insect to remain on the plant, nor do they prevent the feeding action from being released. This may lead to the cyclic process represented in fig. 6. The factors regulating intensity of motivation and threshold releasing stimulus are discussed.

1. Rapidement après l'éclosion, le premier stade larvaire de Leptinotarsa fait au hasard des mouvements d'exploration.

2. Ces mouvements peuvent ětre dirigés par la lumière (intensité, couleur) et par l'odeur de la feuille de Solanum.

3. Chez une larve en exploration, la morsure faite au hasard est un autre élément du comportement spontané, qui peut ětre inhibé par les impulsions reçues par les palpes.

4. Le début et le maintien de l'alimentation dépendent partiellement de différents stimuli, comme le montre le comportement de la larve sur Solanum demissum. Les substances inhibant l'ingestion d'aliment n'empěchent pas nécessairement l'acte alimentaire d'ětre déclanché.

5. Ceci peut aboutir à un cycle fermé représenté dans le diagramme.

6. Le rǒle de constituants nutritifs dans la sélection de la plante‐hǒte est discuté.
DIETETIC REQUIREMENTS AND INTERMEDIARY PROTEIN METABOLISM OF AN INSECT (CALLIPHORA ERYTHROCEPHALA MEIG.)
Authors: SEDEE J. W.
Published: April 2011

Calliphora erythrocephala commonly known as the Bluebottle belongs to the Diptera. The larvae of this insect feed on food which is heavily infected with bacteria. Unlike most other terrestrial insects which excrete uric acid, the larvae of C. erythrocephala excrete ammonia, the most toxic end product of nitrogen metabolism. In this direct excretion of ammonia the larvae therefore behave like many aquatic animals. Under natural conditions the larvae grow very rapidly. After a growth period of six or seven days they become mature, stop feeding, migrate to a dry place and then pupate.

Although the larvae of C. erythrocephala usually live in an environment heavily contaminated with bacteria, it is possible to rear the larvae from the egg under aseptic conditions. When reared on adequate diets the aseptic larvae grow as well as those under natural conditions and metamorphose into normal adult flies.

As in its mode of feeding and living the larvae of the Bluebottle are extreme specialists, it was to be expected that these specialisations may influence its dietetic requirements and intermediary metabolism. In how far these expectations came true was studied in a series of experiments in which the larvae were reared under aseptic conditions so that the intestinal bacteria could not interfere with the results of the feeding experiments and those of the study of the intermediary metabolism.
HOST FINDING OF CHOETOSPILA ELEGANS WESTW. (HYM. CHALCID.) A PARASITE OF SITOPHILUS GRANARIUS L. (COLEOPT. CURCUL.)
Authors: VAN DEN ASSEM J. , KUENEN D. J.
Published: April 2011

The parasite Choetospila elegans is an ectoparasite on Coleoptera larvae and was studied in relation to Sitophilus granarius. Only 3rd and 4th stage larvae are parasitized, as a rule, and it is possible that late 2nd stage larvae are occasionally attacked.

Larvae within grain are found by detection of mechanical stimuli set up by the larvae's activity which can be imitated by other animals moving within a hollow grain. This agrees with the fact that the parasites choose grains containing the largest of the active stages of the weevil.

Der Parasit Choetospila elegans lebt als Ektoparasit an Käferlarven und wurde in Beziehung zu Shophilus granarius untersucht. In der Regel wird nur das 3. und 4. Larvenstadium parasitiert, aber es ist möglich, daß gelegentlich ältere Larven des 2. Stadiums befallen werden.

Die innerhalb der Körner lebenden Larven werden durch Wahrnehmung mechanischer Reize gefunden, die durch Aktivität der Larven hervorgerufen, aber auch von anderen Tieren nachgeahmt werden können, die sich innerhalb eines hohlen Kornes bewegen. Das stimmt mit der Tatsache überein, daß die Parasiten die Körner mit den größten der aktiven Stadien des Käfers auswählen.
THE FEEDING AND EXCRETION RATES OF APHIS FABAE SCOP. ON VICIA FABA L
Authors: BANKS C. J. , NIXON H. L.
Published: April 2011

The feeding and excretion rates of nymphs of Aphis fabae, feeding on young leaves of Vicia faba, were studied, using host plants grown in water culture and made radioactive with 32P. The amounts of sap ingested at first were small but the rate of ingestion increased rapidly between 12 and 16 hr. The maximum rate of feeding was estimated at 0.2 mg sap/hr, an uptake of 59 per cent of the mean body weight of the insects per hour. The results are discussed in relation to other recent work on aphid feeding and excretion.

DIE NAHRUNGSAUFNAHME‐ UND EXKRETIONSRATEN VON APHIS FABAE SCOP. AN VICIA FABA L.

Unter Benutzung von Wirtspflanzen, die in Wasserkultur angezogen und mit 32T radioaktiv gemacht waren, wurden Nahrungsaufnahme‐ und Exkretionsraten der Larven von Aphis fabae untersucht, die an jungen Blättern von Vicia faba saugten. Die aufgenommenen Saftmengen wurden für Zeitabschnitte von 1–24 Stunden Dauer geprüft. Die maximale Nahrungsaufnahmerate wurde mit 0,2 mg/Stunden geschätzt. Die Exkretionsrate von 32P variierte beträchtlich, war aber bei kürzerer Nahrungsaufnahme von weniger als 12 Stunden Dauer höher, und bei längeren Nahrungsaufnahmezeiten niedriger und weniger variabel. Die Ergebnisse werden im Hinblick auf andere neuere Arbeiten über die Ernährung und Exkretion von Blattläusen diskutiert. Es wird vermutet, daß die maximale Rate der Nahrungsaufname, die für diese Insekten angegeben wird, unter den Bedingungen des Versuchs die “normale” war und daß die Mehrzahl der Aphiden offenbar 12 Stunden oder mehr brauchen, um mit ihren Stechborsten bis zum Phloem vorzudringen.
EFFECT OF THE MUTILATION OF WINGS ON THE REPRODUCTION OF THE BEAN APHID APHIS FABAE SCOP
Authors: CHIANG H. C.
Published: April 2011

Mutilation of the wings by pinching and twisting them immediately after the aphid emerged hastened its reproduction. The hastening was more striking among individuals so treated which were kept in light than those kept in dark. Reproduction was also hastened, but to a slighter degree, among individuals with naturally deformed wings.

It has been shown by earlier workers that bodily exercises hastened reproduction. The facts revealed in the present paper suggest that the nervous changes resulting from bodily exercise are more important than the actual exercises themselves.

DIE WIRKUNG DER FLUGELVERSTÜMMELUNG AUF DIE FORTPFLANZUNG DER SCHWARZEN BOHNENLAUS, APHIS FABAE SCOP.

Verstümmelung der Flügel durch Zusammenpressen und ‐drehen gleich nach der Häutung beschleunigte die Fortpflanzung der Blattläuse. Diese Beschleunigung war unter im Licht gehaltenen Tieren auffallender als unter solchen, die in der Dunkelheit gehalten wurden. Die Fortpflanzung ging auch bei solchen Blattläusen — wenn auch im geringeren Grade — schneller vor sich, die ohne künstlichen Eingriff schon mit verstümmelten Flügeln schlüpften.

Von früheren Autoren ist gezeigt worden, daß auch körperliche Betätigung die Fortpflanzung beschleunigte. Die Befunde der vorliegenden Arbeit weisen nun darauf hin, daß die durch körperliche Bewegung verursachte Nerventätigkeit wichtiger ist als die Ausübung selbst.
DIE WIRKUNG VON APHIDENSTICHEN AUF PFLANZLICHE ZELLEN
Authors: MAREK JOHANNES
Published: April 2011

Die Aphiden rufen durch den Einstich bei ihren Wirtspflanzen Reaktionen mannigfaltiger Art hervor. So sind uns Auswirkungen auf den Wasserhaushalt und den Stoffwechsel pflanzlicher Gewebe bekannt, die auf die Einwirkung pflanzensaugender Insekten zurückzuführen sind. Diese Reaktionen werden durch das Zusammenwirken der mechanischen und chemischen Komponente des Stiches ausgelöst.

Die Arbeit ist durchgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft. Zu besonderem Dank bin ich für Förderung der Arbeit Herrn Professor Dr. K. Gößwald und Herrn Privat‐Dozenten Dr. W. Kloft verpflichtet.

EFFECTS OF PIERCING PLANTS‐CELLS BY APHIDS

The result of puncturing plant‐cells by aphids was demonstrated as follows: The aphids, Myzus astralunicus Donc., were allowed to pierce detached bulb scales of Allium cepa, in green light, and were then anaesthetized with CO2. The stylets were then severed using iridectomy scissors (Fig, 1). The epidermis was dissected off, mounted on a slide and observed under a phase‐contrast microscope. The point of injection remained marked by the stylets which stuck in the epidermis. Intercellular and extracellular puncturing could be distinguished.

It was possible to demonstrate a shortening of the time deplasmolysis in the cells lying close to the injection, and also an increase of streaming in the cell plasma. In cells which had been pierced directly, a saliva‐sheath was formed (Fig. 2 and 3). The extent of the effect of the saliva was studied using radioactive aphids. After these radioactive aphids had pierced the epidermis the part containing the stylets was mounted on a slide. This preparation was kept in the dark for 14 days, with a special film (Kodak, Scientific Plates, Auto radiographic) covering it. The film was developed and fixed, and a preparation was thus obtained with the developed film covering the epidermis. Darkened spots on the film showed the parts of the cells which had been made radioactive by the saliva.

Very fine needles made by galvanic etching were also stuck into the cells, to demonstrate the mechanical effects of aphid punctures. This mechanical stimulus by needles only a few μ in diameter caused streaming in the cell plasma and a shortening of deplasmolysis time. It is clear that the importance of these mechanical effects must not be underestimated. The increased plasma‐streaming was apparently caused by ammo‐acids in aphid's saliva, and also by the amino‐acids produced from proteins when the cells were injured. Kloft (1956) found 4 amino‐acids in the saliva of M. ascalonicus. The effect of these amino‐acids on deplasmolysis‐time is being examined, but as yet no effect has been detected.

Finally, when fine glass‐capillaries are used to imitate piercing by plantsucking insects and when the glass‐capillaries contain amino‐acids, deplasmolysis‐time is reduced.
DISPERSAL OF THE GLASSHOUSE RED SPIDER MITETETRANYCHUS URTICAEKOCH (ACARINA, TETRANYCHIDAE)
Authors: HUSSEY N. W. , PARR W. J.
Published: April 2011

Under glass Tetranychus urticae Koch spreads by (a) migration of teneral females to ovi‐position sites (b) migration of mites from heavily infested plants by falling without the usual silken parachutes normally used by Tetranychid mites and (c) movement over the soil surface in accordance with the plane of polarized light.

It is postulated that the effect of this combination of dispersal mechanisms is to restrict mite populations to one portion of a glasshouse from season to season with relatively slow lateral spread from these centres during each growing season.

DIE AUSBREITUNG DER BOHNENSPINNMILBE TETRANYCHUS URTICAE KOCH (ACARINA, TETRANYCHIDAE)

Bewegung auf der Wirtspflanze ist auf negativ geotaktisches Wandern der jungen Weibchen beschränkt, während Abwanderung nur stattfindet, wenn die Wirtspflanze so sehr zu Schaden gekommen ist, daß an den obersten Teilen der Pflanze keine frischen Blätter mehr vorhanden sind.

Experimente haben gezeigt, daß — ungleich anderen Tetranychiden — Milben dieser Art nicht an “seidenen Fallschirmen” in der Luft treiben können, sondern zwangsläufig von “seidenen Fäden” zu Boden fallen, die sie als pendelnde Taue an stark befallenen Pflanzen bilden. Am Boden reagieren die Milben auf die Ebene des polarisierten Lichtes.

Es wird daraus geschlossen, daß in Gurkenhäusern die Ausbreitung von den Überwinterungsplätzen oder stark befallenen Pflanzen aus seitwärts nur in beschränktem Ausmaße erfolgt, so daß die Kolonien von Jahr zu Jahr in den gleichen Teilen des Gewächshauses auftreten.
BIOCHEMISTRY AND GENETICS OF ESTERASES IN HOUSEFLIES (MUSCA DOMESTICA) WITH SPECIAL REFERENCE TO THE DEVELOPMENT OF RESISTANCE TO ORGANOPHOSPHORUS COMPOUNDS*
Authors: VAN ASPEREN K.
Published: April 2011

The paper reviews and reconsiders the experimental work on esterases in the housefly performed in the Laboratory for Research on Insecticides in Wageningen (formerly in Utrecht). It is attempted to integrate the different aspects of former studies, adding new data where necessary and possible. Two subjects that are intimately connected with esterases are briefly discussed, viz. the mode of action of organophosphorus insecticides and the mechanism of resistance to these compounds. A discussion on the possible functions of the esterases studied concludes the paper.

BIOCHEMIE UND GENETIK DER ESTERASEN IN STUBENFLIEGEN (MUSCA DOMESTICA), MIT SPEZIELLER BERÜCKSICHTIGUNG DER RESISTENZ GEGEN ORGANISCHE PHOSPHORVERBINDUNGEN

Die Arbeit gibt eine Übersicht über die experimentellen Untersuchungen an Esterasen der Stubenfliege, die im Laboratorium für Insektizid‐Forschung durchgeführt wurden. Es wurde versucht, die verschiedenen Aspekte früherer Arbeiten zu integrieren; nötigenfalls sind neue Daten beigefügt. Zwei Probleme, die sehr eng mit der Aktivität von Esterasen verknüpft sind, nämlich der Wirkungsmechanismus der Phosphorsäureester und die Resistenz gegen diese Substanzen werden ebenfalls besprochen. Eine Betrachtung über die Funktion der Esterasen beschließt die Arbeit.
GROWTH AND FOOD CONSUMPTION DURING THE LARVAL STAGES OF PAROPSIS ATOMARIA (COLEOPTERA: CHRYSOMELIDAE)
Authors: CARNE P. B.
Published: April 2011

The relative gross efficiency of food utilization by the larvae of Paropsis atomaria was estimated on eight occasions during their development on shoots of their preferred host plant, Eucalyptus blakelyi. The overall conversion ratio of 0.200 is compared with the ratios determined by other authors for a range of phytophagous insects. The ratios obtained for the separate growth stages of P. atomaria suggest that conversion efficiency declines temporarily following each ecdysis, and as the final‐instar larva approaches maturity.

WACHSTUM UND NAHRUNGSAUFNAHME DER LARVENSTADIEN VON PAROPSIS ATOMARIA (COLEOPTERA: CHRYSOMELIDAE)

Die Käferlarven wurden im Laboratorium auf abgeschnittenen Trieben der bevorzugten Wirtspflanze, Eucalyptus blakelyi Maiden, gezüchtet. Außer während des ersten Larvenstadiums und während der letzten Tage des vierten Larvenstadiums vergrößerte sich der Zuwachs der Larven mit der Zeit geometrisch.

Der große Futterausnützungs‐Quotient oder die “Umsatzrate” (Lebendgewichtzuwachs der Larven/Frischgewicht des aufgenommenen Futters) wurde während der 18 Tage des Larvenlebens 8mal gemessen. Die Umsatzrate sank vorübergehend nach jeder Häutung und auch in den letzten Tagen des vierten Larvenstadiums. Während dieser letzten Periode nahm das Wachstum der Larven verhältnismäßig schneller ab als die Nahrungsaufnahme; gleichzeitig erhöhte sich der Wassergehalt im Kot.

Die Umsatzraten von P. atomaria (0.200) und der ebenfalls Eucalyptus‐Blätter fressenden Sägewespe Perga affinis (0.242) liegen in der Mitte des Bereichs des Quotienten, der von anderen Autoren für pflanzenfressende Insektenarten ermittelt wurde.
FORMATION OF SEXUPARAE IN THE APHID, ERIOSOMA PYRICOLA, ON PEAR ROOTS1
Authors: SETHI S. L. , SWENSON K. G.
Published: April 2011

Alate sexuparae were produced in cultures of the aphid, Eriosoma pyricola Baker & Davidson, on the roots of pear plants treated to induce cessation of shoot growth. No sexuparae were produced as long as shoot growth continued. E. pyricola could be cultured on detached pieces of pear root. Sexuparae were not produced in such cultures exposed to constant temperatures over a range from 12° to 27° in continuous darkness. Nor were they produced on detached root pieces with either 16‐hr or 10‐hr photoperiods. No sexuparae were produced when plants were exposed for 4 weeks to environmental conditions that induced cessation of growth and their roots were detached and infested with virginoparous aphids. Nor were sexuparae produced on root pieces from dormant plants from the field.

DIE BILDUNG VON SEXUPAREN BEI DER BLATTLAUS ERIOSOMA PYRICOLA AN BIRNBAUMWURZELN

In Zuchten der Blattlaus Eriosoma pyricola auf den Wurzeln von Birnenpflanzen, deren Wachstum durch bestimmte Behandlung zum Stillstand gebracht worden war, wurden geflügelte Sexupare gebildet. Solange das Triebwachstum fortdauerte, wurden keine Sexuparen hervorgebracht. Wachstumsstillstand wurde bei den Birnensämlingen durch Behandlung mit Kurztagen, 10 Std Licht und 14 Std Dunkelheit, bei konstant 24° induziert. Birnensämlinge, die unter Langtag, 16 Std Licht bei 24° und 8 Std Dunkelheit bei 18°, gehalten wurden, blieben viel längere Zeit wüchsig. Bei der Induktion des Wachstumsstillstandes schienen die Nachttemperaturen wichtiger als die Tageslänge zu sein. Unter den Birnensämlingen trat hinsichtlich ihrer Reaktion auf Umweltbedingungen genetische Variabilität auf. Gelegentlich hörte ein Sämling unter Langtagbedingungen auf zu wachsen oder wuchs unter Kurztagbedingungen weiter. In diesen Fällen war die Produktion von Sexuparen in den Blattlauskolonien auf den Wurzeln vom Pflanzenwachstum und nicht von den Umweltfaktoren abhängig. E. pyricola konnte auf abgeschnittenen Birnenwurzelstücken gehalten werden. In solchen Zuchten wurden keine Sexupare erzeugt, wenn sie im Dauerdunkel konstanten Temperaturen zwischen 12 und 27° ausgesetzt waren. Diese wurden auf abgeschnittenen Wurzelstücken auch nicht hervorgebracht, wenn die Aphiden Photoperioden von 16 oder 10 Std Licht erhielten. Keine Sexupare entstanden, wenn Pflanzen für 4 Wochen Umwelteinflüssen ausgesetzt wurden, die das Wachstum zum Stillstand bringen, und ihre Wurzeln dann abgeschnitten und mit virginoparen Aphiden besiedelt wurden; noch wurden Sexupare auf Wurzelstücken von ruhenden Pflanzen aus dem Freiland erzeugt.
EFFECT OF DESICCATION ON THE LIGHT REACTIONS OF CARPOPHILUS DIMIDIATUS AND TRIBOLIUM CASTANEUM
Authors: AMOS T. G. , WATERHOUSE F. L.
Published: April 2011

The effect of desiccation on the light reactions of Carpophilus dimidiatus and Tribolium castaneum was studied. The results indicated that in C. dimidiatus the light reactions of normal adults of either sex were unaffected by humidity conditions. After desiccation, light responses were found to vary according to humidity conditions and also with respect to the sex of adults examined. In T. castaneum normal adults showed different light reactions according to the humidity test conditions. However at one condition only, i.e. ‘high’ humidity, the sexes responded differently. After desiccation light responses were still found to vary according to humidity but in both ‘high’ and ‘low’ humidities the response varied according to sex.

INFLUENCE DE LA DESSICCATION SUR LES RÉACTIONS À LA LUMIÈRE DE CARPOPHILUS DIMIDIATUS ET TRIBOLIUM CASTANEUM

On a étudié l'action de la dessiccation sur les réactions à la lumière de Carpophilus dimidiatus et Tribolium castaneum. Les résultats indiquent que les réactions à la lumière des adultes normaux de C. dimidiatus des deux sexes sont indépendantes des conditions d'humidité. Après dessiccation, les réponses à la lumière ont varié suivant les conditions d'humidité et aussi selon le sexe des adultes examinés. Chez Tribolium castaneum, les adultes normaux ont manifesté des réactions différentes à la lumière en fonction des conditions d'humidité. Cependant dans une condition unique, c'est à dire une humidité «élevée», les sexes ont répondu différemment. Après dessiccation, les réactions à la lumière ont toujours été trouvées variables selon l'humidité, mais pour les deux humidités élevée et basse la réponse a varié suivant le sexe de l'adulte.
BIOCHEMICAL STUDIES ON INSECTICIDE RESISTANCE IN MUSCA DOMESTICA
Authors: GIL L. , FINE B. C. , DINAMARCA M. L. , BALAZS I. , BUSVINE J. R. , AGOSIN M.
Published: April 2011

Microsomal metabolism of DDT is more active in housefly strains showing resistance to DDT. Susceptible as well as resistant strains produce two fairly polar metabolites in vitro (metabolites 2 and 3), and a water‐soluble metabolite (metabolite 1). Resistance to DDT in one of the strains studied (Fe) is apparently brought about by the production of large amounts of metabolite 1 in vivo and not by DDT‐dehydrochlorination. DDT‐dehydrochlorination can explain resistance per se in two strains (P2/sel and DS), but additional degrees of resistance are given in the P2/sel strain by microsomal enzyme activity. The two strains (Fc and P2/sel) which employ microsomal oxidative enzymes show induction of microsomal enzymes upon DDT pre‐treatment. This enzyme induction by DDT is accompanied by an increase in the rate of incorporation of C14‐labelled uracil into total RNA. It is suggested that cross‐resistance between DDT and pyrethrum (with associated resistance to naphthalene) may be related to microsomal enzyme induction.

BIOCHEMISCHE UNTERSUCHUNGEN AN DER INSEKTIZID‐RESISTENZ VON MUSCA DOMESTICA

Der mikrosomale DDT‐Stoffwechsel ist stärker bei Hausfliegenarten, die Resistenz gegen DDT aufweisen. Sowohl die empfindlichen wie die widerstandsfähigen Arten bringen in vitro zwei annähernd polare Metabolyte (Metabolyt 2 und 3) und einen wasserlöslichen Metabolyten hervor (Metabolyt 1). Die Resistenz gegen DDT bei einem der untersuchten Stämme (Fe) wird vermutlich durch das Zustandekommen grosser Mengen von Metabolyt 1 in vivo und nicht durch DDT‐Dehydrochlorination verursacht. Die DDT‐Dehydrochlorination an sich erklärt die Resistenz bei zwei Stämmen, P2/sel und DS, doch wird die Resistenz bei P2/sel noch durch mikrosomale Enzymtätigkeit erhöht. Die Stämme Fe und P2/sel, bei denen mikrosomale Oxydationsenzyme zur Wirkung kommen, weisen nach DDT‐Vorbehandlung eine Induktion der mikrosomalen Enzyme auf.

Gleichlaufend mit dieser Induktion der Enzyme durch DDT erfolgt eine grössere Aufnahme von C14‐markiertem Uracyl in die RNS. Es wird vermutet, daß die “cross‐resistance” zwischen DDT und Pyrethrum (und gleichzeitiger Resistenz gegen Naphthalin) in Zusammenhang mit der mikrosomalen Enzyminduktion stehen könnte.
THE IMPORTANCE OF WATER IN THE NORMAL GROWTH OF LARVAE OF TENEBRIO MOLITOR
Authors: MURRAY D. R. P.
Published: April 2011

Although Tenebrio molitor larvae can exhibit extremely regular growth curves, all too frequently they do not. The role of water in this failure is investigated.

When the larvae feed on wholemeal flour the humidity is of little consequence, but when there is much roughage (bran), and metabolic water per unit weight of food is low, the relative humidity becomes a critical factor and in the absence of drinking water successful development may become impossible. With steadily lowered humidity the difference between larvae given access to water and those deprived of it becomes progressively more marked.

DIE BEDEUTUNG DES WASSERS BEIM NORMALEN WACHSTUM DER LARVE VON TENEBRIO MOLITOR

Im Gegensatz zur allgemeinen Annahme ist es möglich, außerordentlich regelmäßige Wachstumskurven von Larven des Mehlkäfers zu erhalten; sie bestehen aus alternierenden Abschnitten linearen Wachstums und nicht aus einem Netto‐Wachstum von etwa gleichmäßiger Dauer. Jedoch sind Abweichungen von diesem Ergebnis häufig. Die möglichen Ursachen dieser Abweichungen werden untersucht. Während die häufigste wahrscheinlich das Verschwinden der als Freßreiz verantwortlichen Substanz aus der Nahrung darstellt, ist ein anderer mächtiger Einfluß die Verfügbarkeit von Wasser.

Änderungen der Feuchtigkeit, die aus einem Unterschied in der von der Nahrung absorbierten Wassermenge herrühren, verursachen nur geringe Unterschiede, wenn die Larven in voll‐ausgemahlenem Mehl heranwachsen; aber wenn die Nahrung aus Kleie besteht mit ihrem hohen Anteil unverdaulicher Substanzen und einer geringen Ergiebigkeit von Stoffwechselwasser pro Gewichtseinheit der Nahrung, dann wird die relative Luftfeuchtigkeit zu einem kritischen Faktor. Unter diesen Umständen kann der Zugang zu trinkbarem Wasser den ganzen Unterschied zwischen Erfolg und Versagen der Entwicklung ausmachen.

In dem Maße wie die Wasserversorgung zunehmend geringer wird, vermindert sich auch das Gewicht der gefressenen Nahrung, aber zusätzlich ist auch die Zunahme des Körpergewichts pro Einheit aufgenommener Futtermenge sehr herabgesetzt. Bei niedrigsten Feuchtigkeiten wird die Menge der aufgenommenen Nahrung außerordentlich klein, und obwohl enorme Wassermengen getrunken werden mögen, können die Larven ihre Nahrung nicht verwerten und zehren von ihren Fettreserven bis zum Eintritt des Todes.

Eine andere Hemmung des Wachstums unter offensichtlich günstigen Bedingungen wird beschrieben und eine Betrachtung darüber angestellt, ob es sich dabei um einen Fall fakultativer Diapause handeln könnte.
EVALUATION OF OUR THOUGHTS ON SECONDARY PLANT SUBSTANCES
Authors: FRAENKEL G.
Published: April 2011

The paper presents and evaluates modern concepts about the role of the secondary plant substances in the host selection of phytophagous insects. It deals with the following main topics: A. The role of nutrients in host selection. B. The concept of utilization in this context. C. The role of the secondary substances as attractants. D. The role of the secondary substances as repellents. The conclusion is reached that host selection is principally guided by the presence and/or absence of secondary substances, and that qualitatively and quantitatively nutrients can play only a very minor part, if one at all, in this context.

BEWERTUNG UNSERER VORSTELLUNGEN ÜBER SEKUNDÄRE PFLANZENSTOFFE

Die Arbeit bringt und beurteilt moderne Auffassungen über die Rolle der sekundären Pflanzeninhaltsstoffe bei der Wirtswahl phytophager Insekten. Sie enthält die folgenden Hauptabschnitte: A. Die Rolle der Nährstoffe bei der Wirtswahl. B. Die Auffassung der Ausnutzung in diesem Zusammenhang. C. Die Rolle der sekundären Pflanzenstoffe als Attraktants. D. Die Rolle der sekundären Pflanzenstoffe als Repellents. Es wird die Schlußfolgerung gezogen, daß die Wirtspflanzenwahl grundsätzlich von der Gegenwart und/oder dem Fehlen sekundärer Pflanzenstoffe bestimmt wird, und Nährstoffe, wenn überhaupt, in diesem Zusammenhang, quantitativ und qualitativ nur eine sehr untergeordnete Rolle spielen können.