bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fine structure of aphid stylet routes in plant tissues in correlation with EPG signals
Authors: TJALLINGII W. F. , ESCH TH. HOGEN 
Published: March 2008

Abstract. Plant penetration by Aphis fabae (Scopoli) was recorded by the electrical penetration graph (EPG) technique and followed by stylectomy during wave‐forms that were suspected of indicating sieve element punctures. The severed stylets in the plant tissue were subsequently processed for transmission electron microscopy (TEM) and sectioned either transverse or longitudinal to the stylets. Two completely serially sectioned probes from the epidermis to the phloem were reconstructed.In one probe the stylet pathway went to a sieve element and showed many empty branches of salivary sheath material. Breaks in cell walls filled with sheath material demonstrated that the majority of cells bordering the track had been punctured, which supports earlier evidence from EPGs. All types of cells showed punctures and the highest number was found inside the vascular bundle. Very few cells died, which would appear to be important for virus transmission, and in others cellular reactions remained limited to some callose formation. The route of the stylets was intercellular and passed through the secondary wall material. The role of pectinase in intercellular penetration, and previous evidence for intracellular tracks are discussed. Most sieve elements had been punctured but only one was eventually accepted. Thus, reaching a sieve element in a host plant does not automatically imply its acceptance though the reason remains unclear. Gelation of phloem proteins was shown in the stylet canal.In a second probe, plant cytological and morphological correlations with the EPG were emphasized. Probes by other aphid‐plant combinations showed great similarity.
Vibrational alarm communication in the damp‐wood termite Zootermopsis nevadensis
Authors: KIRCHNER WOLFGANG H. , BROECKER INGRID , TAUTZ JÜRGEN 
Published: March 2008

Abstract. Vibrational alarm communication was studied in the New World, damp‐wood termite Zootermopsis nevadensis (Isoptera: Termopsidae). Workers and soldiers react to disturbance such as sudden bright light or air currents by drumming their heads against the substratum. This drumming has been described as alarm signalling; its functional significance and perception by the nest mates, however, remained unclear. In the present study we analysed spectral and temporal properties and absolute amplitudes of the vibrational signals and used behavioural responses of the termites to determine the thresholds of the sense of vibration and to find out if and how the termites discriminate the conspecific alarm signals from the background noise.The drumming signals are trains of pulses of vibrations of the substratum with a pulse repetition rate of about 20 Hz. The carrier frequency depends on the substratum; in the nests studied it was in the range 1–3 kHz. The highest vibrational amplitudes measured close to the signal emitters are usually about 10m/s2 (acceleration, RMS). The threshold of the behavioural response is about 1m/s2 over a wide range of frequencies (10 Hz to 5 kHz), indicating that the termites can detect these signals as vibrations of the substratum. The animals respond preferentially to temporal patterns similar those of the natural signals; temporal rather than spectral cues seem to be used for signal discrimination.
The dynamics of collective exploration and trail‐formation in Monomorium pharaonis: experiments and model
Authors: FOURCASSIÉ V. , DENEUBOURG J. L. 
Published: March 2008

Abstract. When exploring a chemically unmarked area devoid of food sources, workers of the pest ant Monomorium pharaonis L. (Formicidae, Myrmicinae) leave scent marks on the ground and after 30–60min a network of diverging exploratory trails begins to emerge.Exploratory activity is affected by the nutritional state of the colony and a period of food deprivation induces a dramatic increase in the number of workers leaving the nest. A mathematical model based on a logistic growth equation is proposed to describe the exploratory recruitment observed. When travelling along exploratory trails the proportion of ants displaying trail‐laying behaviour is higher for outbound than for nestbound workers. Outbound ants also show a greater propensity than nestbound ants to follow the scent marks of their nestmates. The chemical used to mark a novel area does not appear to be colony‐specific and thus does not have a territorial function sensu stricto. The adaptive value of the collective exploratory behaviour observed in this study is discussed in relation to the common features of other pest ant species described in the literature.
Abdominal ventilatory pattern in crickets depends on the stridulatory motor pattern
Authors: PARIPOVIC I. , HENNIG R.M. , OTTO D. 
Published: March 2008

Abstract. Ventilatory motor patterns were recorded from abdominal muscles in crickets, Gryllus campestris L.and Teleogryllus commodus (Walker), at rest and during three types of stridulatory motor activity; calling, courtship and aggressive song.Increases in ventilatory period were almost exclusively due to an increase of the pause between expiratory bursts, whereas abdominal ventilatory bursts remained constant at 200 ms.Ventilatory patterns depended on the stridulatory motor pattern and indicated that the same basic respiratory oscillator exists in both cricket species.In G.campestris there was a strict 1:1 coupling between chirps and ventilatory bursts.In T.commodus such a relationship was also observed for the chirp part of the songs, but less strictly for the trill part of the calling song and not for the courtship song.In both species the onset of the ventilatory burst was within ± 100 ms of a stridulatory chirp.Ventilatory burst lasted longer the earlier they began before a stridulatory chirp.This suggests strongly that the stridulatory motor pattern terminates the expiratory burst, and thus influences the ventilatory motor pattern.
Laboratory‐simulated naturally‐decreasing day lengths, twilight and aphid photoperiodism
Authors: NUNES MARLIES VAZ , YOUNG STEPHEN , HARDIE JIM 
Published: March 2008

Abstract. Day‐length changes, as well as periods of twilight, that occur in the course of each natural day‐night cycle, were recreated for two chosen latitudes in a computer‐controlled ‘natural‐day‐length simulator’.The photoperiodic responses of two aphid species, Aphis fabae and Megoura viciae, were examined in conditions which mimicked late summer to autumn at two simulated latidudes, 51.5d̀N (e.g.Ascot, Southern Britain) and 60°N (e.g.southern tip of Shetland Islands, Northern Britain), with temperatures between 16°C (‘night’) and 18°C (‘day’).The responses under simulated natural photoperiodic conditions were similar to those observed under conventional experimental conditions of squarewave light‐dark cycles (with abrupt lights‐on and lights‐off and constant light intensities during the light phase): both aphid species responded to civil twilight as light, and the critical day lengths (including civil twilight) for the induction of sexual morphs by the two aphid species observed in the simulator were the same as those found in squarewave light‐dark cycles.Autumn field experiments (51.5°N) with the same clones of A.fabae and M.viciae revealed much longer critical day lengths for gynopara and male induction in A.fabae compared with those in the laboratory, but the same critical day length for ovipara induction in M.viciue. Minimal night temperatures in the field were on average 6°C, whereas maximal day temperatures declined from around 30°C in early September to 12°C at the end of October; it seems that the critical day lengths in A.fabae are temperature dependent, whereas the findings for M.viciae confirm that the critical day length is temperature compensated.
Life history of Galerucella nymphaeae and implications of reproductive diapause for rearing univoltine chrysomelids
Authors: TAUBER MAURICE J. , TAUBER CATHERINE A. , NECHOLS JAMES R. 
Published: March 2008

Abstract. Galerucella nymphaeae L., a chrysomelid that feeds on Lythrum spp., water lily and water chestnut, is closely related to two European species that were recently introduced into North America for biological control of L.salicaria, purple loosestrife. To develop a paradigm for continuously rearing these and other univoltine chrysomelids, we conducted field and laboratory studies on G. nymphaeae's development, reproduction and diapause.A high incidence of reproduction without diapause occurred when fourth instars, pupae, and adults (held as pairs) experienced very long daylengths (LD18:6 h), i.e. longer than those G.nymphaeae encounters in nature. Under similar photoperiodic conditions, adults maintained in groups showed a significantly higher rate of reproductive diapause than those held as pairs. Females laid three to seven egg masses/week, and the size of egg masses varied between nine and nineteen eggs. During their reproductive lifetimes, individual females showed a highly significant propensity to lay a consistent number of eggs/egg mass.After diapausing under short daylengths and low temperature (LD 10:14h, 5d̀C), adults transferred to long days (LD 18:6h at 21d̀C) had high rates of diapause termination and postdiapause oviposition. In contrast, those transferred to short daylengths (LD 10:14h at 21d̀C) had low rates of reproduction.Laboratory‐derived heat‐degree models accurately predicted egg and pupal, but not larval, development in the field. In nature, most females in the summer generation entered reproductive diapause without ovipositing; a small proportion of females that emerged relatively early (by mid June) oviposited before entering diapause. The overwintering population consists of adults from the first‐generation and a small number from the second generation.
Differential photoperiodic responses in genetically identical winged and wingless pea aphids, Acyrthosiphon pisum, and the effect of day length on wing development
Authors: NUNES MARLIES VAZ , HARDIE JIM 
Published: March 2008

Abstract. Winged and wingless individuals of a pink clone of the pea aphid, Acyrthosiphon pisum (Harris), showed differences in the response curves for photoperiodic induction of both males and sexual females (oviparae). The critical night length (CNL) for ovipara induction in winged aphids was 0.75 h shorter than in wingless aphids, whereas the CNL for male induction in winged aphids was 1.0h longer than in wingless aphids. This means that in winged aphids the CNL for male induction in winged aphids was 0.5 h longer than that for ovipara induction, while in wingless aphids the CNL for male induction was 1.0–1.5h shorter than that for ovipara induction, and also the shapes of the curves differed.Winged aphids were produced by wingless mothers which were crowded as young adults. However, when young adults were crowded in long nights, winged aphids were not produced, and the CNL for wing inhibition was between 9.5 and 10h. This effect of photoperiod on wing induction was maternal.
Hormonal control of lutein incorporation into pupal cuticle of the butterfly Inachis and the pupal melanization reducing factor
Authors: STARNECKER GERHARD 
Published: March 2008

Abstract. . Morphological colour adaptation of pupae of the butterfly Inachis io L. (Lepidoptera: Nymphalidae) is controlled by a factor which reduces cuticular melanization (Biickmann & Maisch, 1987). This so‐called pupal melanization reducing factor (PMRF) is located throughout the entire central nervous system of prepupae (Stamecker et al., 1994).Extracts of abdominal ganglia also stimulated dose‐dependently lutein incorporation into pupal cuticle. In the bioassay higher doses were required to increase cuticular lutein content than to reduce melanization. Ligatures during the prepupal stage demonstrated two different critical periods for these pigmentation effects: an early one for melanization reduction and a late one for lutein incorporation.An initial chromatographic purification yielded only two adjacent fractions which contained both the PMRF and the stimulation of lutein incorporation activity. Therefore it is assumed that only one hormone with a dual function may be responsible for pupal pigmentation.Lutein content was found in gut, fat body, epidermis and haemolymph of I.io. Lutein incorporation into cuticle occurred within 1.5 days of the pupal moult when the cuticle was not yet fully sclerotized. Lutein content is significantly higher in cuticle of yellow pupae than of black ones.
Lindernia brevidens: a novel desiccation‐tolerant vascular plant, endemic to ancient tropical rainforests
Authors: Phillips Jonathan R. , Fischer Eberhard , Baron Miriam , Van Den Dries Niels , Facchinelli Fabio , Kutzer Michael , Rahmanzadeh Ramtin , Remus Daniela , Bartels Dorothea 
Published: March 2008

SummaryA particular adaptation to survival under limited water availability has been realized in the desiccation‐tolerant resurrection plants, which tend to grow in a habitat with seasonal rainfall and long dry periods. One of the best‐studied examples is Craterostigma plantagineum. Here we report an unexpected finding: Lindernia brevidens, a close relative of C. plantagineum, exhibits desiccation tolerance, even though it is endemic to the montane rainforests of Tanzania and Kenya, where it never experiences seasonal dry periods. L. brevidens has been found exclusively in two fragments of the ancient Eastern Arc Mountains, which were protected from the devastating Pleistocene droughts by the stable Indian Ocean temperature. Analysis of the microhabitat reveals that L. brevidens is found in the same habitat as hygrophilous plant species, which further indicates that the plant never dries out completely. The objective of this investigation was to address whether C. plantagineum and L. brevidens have desiccation‐related pathways in common, or whether L. brevidens has acquired novel pathways. A third, closely related, desiccation‐sensitive species, Lindernia subracemosa, has been included for comparison. Mechanisms that confer cellular protection during extreme water loss are well conserved between C. plantagineum and L. brevidens, including the interconversion of 2‐octulose to sucrose within the two desiccation‐tolerant species. Furthermore, transcriptional control regions of desiccation‐related genes belonging to the late embryogenesis abundant (LEA) protein family are also highly conserved. We propose that L. brevidens is a neoendemic species that has retained desiccation tolerance through genome stability, despite tolerance being superfluous to environmental conditions.
AGL23, a type I MADS‐box gene that controls female gametophyte and embryo development in Arabidopsis
Authors: Colombo Monica , Masiero Simona , Vanzulli Silvia , Lardelli Paolo , Kater Martin M. , Colombo Lucia 
Published: March 2008

SummaryMADS‐box transcription factors are key regulators of plant developmental processes. While the function of MIKC (type II) MADS‐box genes has been intensively studied, only limited data are available for the other more recently identified classes of MADS‐box genes, despite these latter comprising more than 60% of the Arabidopsis MADS‐box gene family. Here we describe the function of AGL23, an Arabidopsis type I MADS‐box gene belonging to the Mα subfamily. We show that AGL23 plays an important role during development of the female gametophyte and embryo. The agl23‐1 mutant forms a functional megaspore. However, at this stage female gametophyte development is arrested and the megaspore persists during subsequent phases of ovule development. Despite the incomplete penetrance of the female gametophyte defect, plants homozygous for the agl23‐1 mutation were never identified. Analysis of developing seeds showed that embryos homozygous for the agl23‐1 allele are albino and unable to give rise to viable plants. Electron microscopy analysis revealed that this phenotype is due to the absence of chloroplasts, strongly suggesting that AGL23 is involved in controlling the biogenesis of organelles during embryo development.
Identification of major lysine residues of S3‐RNase of Petunia inflata involved in ubiquitin–26S proteasome‐mediated degradation in vitro
Authors: Hua Zhihua , Kao Teh‐hui 
Published: March 2008

SummaryS‐RNase‐based self‐incompatibility has been identified in three flowering plant families, including the Solanaceae, and this self/non‐self recognition mechanism between pollen and pistil is controlled by two polymorphic genes at the S‐locus, S‐RNase and S‐locus F‐box (SLF). S‐RNase is produced in the pistil and taken up by pollen tubes in a non‐S‐haplotype‐specific manner. How an allelic product of SLF interacts with self and non‐self S‐RNases to result in growth inhibition of self pollen tubes is not completely understood. One model predicts that SLF targets non‐self S‐RNases for ubiquitin/26S proteasome‐mediated degradation, thereby only allowing self S‐RNase to exert cytotoxic activity inside a pollen tube. To test this model, we studied whether any of the 20 lysine residues in S3‐RNase of Petunia inflata might be targets for ubiquitination. We identified six lysines near the C‐terminus for which mutation to arginine significantly reduced ubiquitination and degradation of the mutant S3‐RNase, GST:S3‐RNase (K141–164R) in pollen tube extracts. We further showed that GST:S3‐RNase (K141–164R) and GST:S3‐RNase had similar RNase activity, suggesting that their degradation was probably not caused by an ER‐associated protein degradation pathway that removes mis‐folded proteins. Finally, we showed that PiSBP1 (P. inflata S‐RNase binding protein 1), a potential RING‐HC subunit of the PiSLF (P. inflata SLF)‐containing E3‐like complex, could target S‐RNase for ubiquitination in vitro. All these results suggest that ubiquitin/26S proteasome‐dependent degradation of S‐RNase may be an integral part of the S‐RNase‐based self‐incompatibility mechanism.
Epidermal Dysplasia And Malassezia pachydermatis Infection In West Highland White Terriers
Authors: Scott Danny W. , Miller William H. 
Published: March 2008

Abstract— A chronic, severely pruritic, seborrhoeic skin disorder of West Highland White terriers is reported. The dermatosis has no apparent sex predilection, often begins in animals less than one year of age and is probably genetically programmed. This syndrome is characteristically refractory to standard therapeutic regimens.Histologically the dermatosis is characterized by variable degrees of hyperplastic superficial perivascular dermatitis with a keratinization defect, epidermal dysplasia and the presence of budding yeast in surface and follicular keratin. Malassezia pachydermatis is isolated in pure culture from the skin lesions.Because of the unique histological findings in this syndrome, we propose that the disorder be called “epidermal dysplasia and Malassezia pachydermatis infection in the West Highland White terrier”.Résumé— Une affection cutanée chronique, sévèrement, prurigineuse, séborrhéique, est décrite chez des West Highland White terriers. La dermatose, sans prédisposition apparente de sexe, débute souvent sur des animaux agés de moins d'un an et reconnait probablement une origine héréditaire. La caractéristique de ce syndrome est d'étre résistant aux thérapeutiques habituelles.A l'histologie, la dermatose est caractérisée par des degrés variables de dermatite hyperplasique superficielle périvasculaire avec un défaut de kératinisation une dysplasie épidermique et la présence de levures bourgeonnantes dans la kératine superficielle et folliculaire. Malassezia pachydermatis est isolée en culture pure à partir des lésions cutanées.En raison de l'aspect histologique univoque dans ce syndrome, nous proposons que cette affection soit appelée: “Dysplasie épidermique et infection àMalassezia pachydermatis du West Highland White terrier”.Zusammenfassung— Eine chronische, hochgradig pruriginÖse, seborrhoische Hauterkrankung des Westhighland‐White‐Terriers wird beschrieben. Die Dermatose zeigt keine deutliche Geschlechtsdisposition, beginnt oft im Alter unter einem Jahr und ist wahrscheinlich genetisch bedingt. Dieses Syndrom spricht auf die üblichen therapeatischen Maßnahmen nicht an (Diagnostik durch Biopsie).Histologisch ist diese Dermatose gekennzeichnet durch unterschiedliche Grade einer hyperplastischen, superfiziellen, perivaskulären Dermatitis mit Keratinisierungsdefekt, durch epidermale Dysplasie und die Anwesenheit von Sproßpilzen (Hefen) im oberflächlichen und follikulären Keratin.Aus den Hautveränderungen wird Malassezia pachydermatis in Reinkultur isoliert.Wegen der einzigartigen histologischen Befunde bei diesem Syndrom schlagen wir vor, diese Erkrankung “Epidermale Dysplasie und Malassezia pachydermatis—Infektion beim Westhighland‐White‐Terrier” zu nennen.
Essential Fatty Acid Supplementation In The Treatment Of Canine Atopy: A Preliminary Study
Authors: Lloyd David H. , Thomsett Lovell R. 
Published: March 2008

Abstract— In an open, uncontrolled study, 10 dogs with atopy were given evening primrose oil (EPO) (5ml/10kg/day) over a period of 9 weeks. During the first three weeks pruritus, scaling and oedema worsened but erythema and coat condition tended to improve. Subsequently all these parameters tended to improve. The effect on oedema was significant (p < 0.05). Eight of these dogs and two others were then given a 4:1 mixture of EPO and marine fish oil for 9 weeks. Although further reductions in scale and improvements in coat condition were marked in some animals, no significant changes occurred. Alterations in the plasma phospholipid essential fatty acid levels reflected the compositions of the two supplements. These findings suggest that EPO can ameliorate of atopy in dogs. This mirrors observations obtained in studies of human atopic eczema.Résumé— Dans une étude ouverte, sans lot témoin, 10 chiens souffrant d'atopie ont reçu de l'huile d'onagre (5 ml/10 kg/jour) pendant une période de 9 semaines. Pendant les 3 premières semaines, le prurit, le squamosis et l'oedème se sont aggravés mais, l'érythème et l'aspect du poil tendaient à s'améliorer. Enfin tous ces parametres tendaient à s'améliorer. L'effet sur l'érythème a été significatif (p < 0.05). Huit de ces chiens et deux autres ont alors reçu un mélange (4:1) d'huile d'onagre et d'huile de poisson de mer pendant 9 semaines.Bien qu'ultérieurement la diminution du squamosis et l'amélioration de l'état de la fourrure aient été manifestes chez certains animaux, il n'y eut pas de changement significatif. Les modifications des taux d'acides gras essentiels des phospholipides plasmatiques ont reflété la composition des deux supplémentations. Ces observations suggèrent que l'huile d'onagre peut apporter une amélioration de l'atopie canine. Cela reflète certains résultats observés lors d'études sur l'eczéma atopique de l'homme.Zusammenfassung— In einer offenen, nicht kontrollierten Untersuchung wurde 10 Hunden mit Atopie Nachtkerzenöl (EPO) in einer Dosierung von 5 ml/10 kg/Tag über einen Zeitraum von 9 Wochen verabreicht. Während der ersten 3 Wochen verschlimmerten sich Pruritus, Schuppenbildung und Ödeme, während Erytheme und Fellzustand eher eine Tendenz zur Besserung zeigten. Danach besserten sich alle diese Parameter. Die Wirkung auf Erytheme war signifikant (p < 0.05). Acht dieser Hunde und zwei andere erhielten 9 Wochen lang Nachtkerzenöl und Seefischöl in einer Mischung von 4:1 im Anschlufl an diese Untersuchung.Obwohl eine weitere Verminderung der Schuppenbildung und eine Vorbesserung der Fellqualität bei einigen Tieren festgestellt wurden, waren diese Veränderungen nicht signifikant.Die Veränderungen der essentiellen phospholipiden Fettsäuren im Plasma spiegeln die Zusammensetzung der beiden verabreichten Öle wieder. Diese Befunde weisen darauf hin, daß die Atopie des Hundes durch EPO gebessert werden kann. Dies entspricht auch Beobachtungen bei Untersuchungen des atopischen Exzems des Menschen.