bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vaccination of calves againstOstertagia ostertagiwith cysteine proteinase enriched protein fractions
Authors: Geldhof P. , Claerebout E. , Knox D. , Vercauteren I. , Looszova A. , Vercruysse J. 
Published: March 2003

SummaryCysteine proteinase enriched fractions obtained by thiol‐sepharose chromatography ofOstertagia ostertagimembrane‐bound protein extract (S3‐thiol) or total adult excretory–secretory (ES‐thiol) products were tested in a vaccination experiment to evaluate their protective efficacy againstO. ostertagiin cattle. Calves were vaccinated three times and subsequently challenged with a trickled infection of 25 000 infective larvae in total over 25 days (1000 L3/day, 5 days/week). Geometric mean cumulative egg counts in the ES‐thiol group were reduced by 60% during the 2‐month period between the first challenge infection and necropsy, compared to the control group (P < 0·002). No reduction in egg output was observed in the S3‐thiol group. At necropsy, calves immunized with ES‐thiol had a significantly higher percentage of inhibited L4 larvae (9·8%) and had in total 18% less worms than the control calves, but this reduction was not statistically significant. Both the female and male adult worms were significantly smaller in the ES‐thiol group than in the control group. Although no significant difference was observed in the number of eggs per female worm between the groups, there was a trend to less eggs per female worm in the ES‐thiol group. Number of worms, size of adult worms and number of eggs per female worm were not significantly different between the S3‐thiol group and the control group. Systemic immunization with QuilA as adjuvant induced a significant rise inOstertagia‐specific antibody levels in the abomasal mucosa.Ostertagia‐specific local antibody levels showed a significant negative correlation with the size of the adult worms, the number of eggs per female worm and the cumulative faecal egg counts. However, these correlations were quite weak and did not appear to be isotype‐specific.
Production of a recombinant version of a Heligmosomoides polygyrus antigen that is preferentially recognized by resistant mouse strains
Authors: Hoselton Scott , Piche Lisa , Gustad Thomas , Robinson Michael 
Published: March 2003

SummaryProtective immunity to the mouse nematode parasite, Heligmosomoides polygyrus, has been characterized and found to be composed of the Th2 type. However, many inbred mouse strains cannot produce this protective immune response during a primary infection. A possible reason for this lack of protection in poor responding strains could be due to lack of recognition of specific protective antigens by these strains. Recently, evidence suggests that specific antigens exist that are only recognized by fast responding strains during a primary infection. Using monoclonal antibodies to screen an H. polygyrus cDNA library enabled the production of a recombinant protein, 3A4, which is antigenically similar to those found in the excretory/secretory antigens (E/S) of both L4 and adult parasites. Protein 3A4 shares approximately 70% sequence homology with an E/S protein that induces protection to Trichostrongylus colubriformis in guinea‐pigs. Antibodies that bind to 3A4 are preferentially produced in SWR compared to BALB/c mice following immunization with L4 homogenate, although both strains of mice were able to produce comparable levels of specific antibodies after immunization with 3A4 protein. It is believed that 3A4 may have considerable importance in dissecting out the nature of the immune response to H. polygyrus infection, particularly in mouse strains of differing response phenotype.
Duration of behaviour patterns during oviposition by the bruchid beetle, Callosobruchus maculatus
Authors: PARR MARTIN , TRAN BRUNO , SIMMONDS MONIQUE , CREDLAND PETER 
Published: March 2003

The behaviour of insects between making contact with a potential oviposition site and the act of oviposition itself determines the conditions in which their progeny begin development and, in many cases, whether a crop or commodity is damaged. In this paper the behaviour of female cowpea seed beetles, Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae), during this period has been examined. The duration of discrete behaviour patterns within this period and the transitional frequencies between them have been used to compare the behaviour of beetles on two different hosts. In a 30‐min period, beetles laid more eggs on mung than adzuki beans and rejected mung as an oviposition site much less frequently.A log‐linear contingency table analysis of the transitional frequencies indicated a highly significant interaction between successive behaviours and between the second of the two behaviours and the host seed, indicating that the sequence of behaviours is partially determined by the host seed. Grooming, departure from the seed and loops in behavioural sequences occur more often on adzuki than mung and are indicative of a less acceptable host. Discriminant analysis showed that the total time spent exhibiting different behaviour patterns was significantly different on the two hosts. Mann–Whitney tests revealed small but significant differences in the mean durations of only three behaviour patterns on the two seed types.Measurement of the duration of each behavioural pattern confirms what can be deduced about host acceptability by observing the simple occurrence of different behavioural patterns and the determination of the frequency of transitions between them. Differences in acceptability were predominantly reflected in the frequency of certain behaviour patterns and of particular transitions from one pattern to another, not in the mean duration of each exhibition of a defined behaviour pattern. It is argued that the utility of measuring the duration of behavioural elements could only be demonstrated because behavioural patterns or categories were precisely defined.
Diversity in gas exchange and muscular activity patterns in insects studied by a respirometer‐actograph
Authors: Tartes Urmas , Kuusik Aare , Vanatoa Alo 
Published: March 2003

SummaryDifferent events in insect gas exchange and muscular activity are described by a new system of automatic respirometers, a differential electrolytic microrespirometer‐actograph. This is very sensitive to volumetric changes caused by insect respiration and/or body movements. In this system, oxygen generation and its regulation are combined in the same current circuit. According to this principle, the oxygen consumed by the insect is continuously replaced by equal amounts of electrolytically produced oxygen. This simple laboratory‐made apparatus records simultaneously metabolic rate, the cyclicity of external gas exchange, rhythms of muscular ventilating and the pattern of other body movements, including abdominal pulsations not observable with the naked eye. The respirometer‐actograph described here is applicable also to the recording of the respiration of other terrestrial arthropods or other living organisms or tissues.
Geographic variation in cold hardiness of eggs and neonate larvae of the yellow‐spotted longicorn beetle Psacothea hilaris
Authors: Shintani Yoshinori , Ishikawa Yukio 
Published: March 2003

SummaryCold hardiness of eggs and neonate larvae of the yellow‐spotted longicorn beetle, Psacothea hilaris (Pascoe) was examined using six geographical populations in Japan. Particular attention was paid to cold hardiness of eggs and neonate larvae of the subtropical population (Ishigaki), because the east Japan populations are considered to have been introduced from a subtropical area, and the overwintering stage in the east Japan populations is incidentally shifted from the original mature larval stage to the egg or neonate larval stages. When the eggs were exposed to low temperatures for 1 h, the decrease in hatchability became significant at –12°C in the southernmost two populations (Ishigaki and Naze), and at –16°C in the northern populations. After 1 h exposure to –20°C, few eggs could hatch in the Ishigaki population, whereas 27–55% of the eggs survived in the northern populations. Pre‐chilling of the eggs at 10°C for 10 days enhanced the cold hardiness in all populations. This effect was particularly distinct in the subtropical population; the eggs of the Ishigaki population became as cold hardy as those of the northern populations after acclimation. These results suggest that the subtropical population is capable of establishing itself in east Japan, where the winter is cold.
Localization of the photoreceptor for photoperiodism in the stink bug, Plautia crossota stali
Authors: Morita Akihiro , Numata Hideharu 
Published: March 2003

SummaryThe brown‐winged green bug Plautia crossota stali Scott (Heteroptera: Pentatomidae) shows a long‐day photoperiodic response with respect to the control of adult diapause. The location of the photoreceptor for this response was examined by surgical removal of putative photoreceptor organs. Even after both ocelli were removed, the insects responded normally to the photoperiod. After bilateral removal of the compound eyes, the insects developed reproductive organs and the volume of the corpus allatum increased regardless of photoperiod. Therefore, the compound eyes play a major role in the reception of photic information for photoperiodism in P. c. stali. However, because removal of the bilateral compound eyes did not completely prevent the response to photoperiod, photoreceptors other than the compound eyes can also receive photic information for photoperiodism.
Real‐time measurement of pheromone release from individual female moths and synthetic dispensers in a wind tunnel by recording of single receptor‐neurone responses
Authors: Valeur Peter G. , Hansson BilL. S. , Löfstedt Christer 
Published: March 2003

SummaryMeasurements of single neurone activity in the peripheral pheromone receptors of male Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae) were performed in a wind tunnel using a portable electrophysiological recording unit. Filter paper and rubber septa loaded with synthetic sex pheromone, as well as individual conspecific female glands, were used as pheromone sources. Recordings, up to 3 h long, were analysed for temporal variation in spiking activity. The recordings were performed 2 m downwind of the source, where the pheromone plume had a width of approximately 12 cm, as could be measured with the single cell preparations. The system allowed reliable measurements of relative pheromone concentration with a 20‐s time resolution. The release rate from rubber septa loaded with pheromone was more or less constant over time, whereas the release rate from filter paper loaded with pheromone decreased to one tenth of the initial value within 6 min from the application of the pheromone. The release of pheromone from female pheromone glands was pulsed with an interval of 2–10 min between bursts. This pulsing was not caused by retraction of the gland, as the glands were forcibly extruded during the entire experiment, but should reflect variation in transport of pheromone to the gland surface and subsequent release. The demonstrated stability of the preparations using tungsten electrodes, the reliable monitoring of female‐produced pheromone plumes at several metres distance, and the time resolution obtained are important steps towards field monitoring of natural pheromone plumes, as well as pheromone concentration and distribution in applications for mating disruption.
Respiratory physiology and water relations of three species of Pogonomyrmex harvester ants (Hymenoptera: Formicidae)
Authors: Quinlan Michael C. , Lighton JohN. R. B. 
Published: March 2003

AbstractThe respiratory physiology and water relations of three harvester ant species (Pogonomyrmex rugosus Emery, P. occidentalis[Cresson] and P. californicus[Buckley]) were examined at three temperatures (15, 25 and 35°C) using a flow‐through respirometry system. As intact ants tended to be active during testing, we performed a parallel set of experiments on individuals rendered motionless by decapitation. Both intact and decapitated ants exhibited discontinuous ventilation. Decapitation caused metabolic rate (V˙CO2) and burst frequency to decrease in all three species. Burst volume either remained constant or increased after removal of the head, though mass‐specific V˙CO2 was unaffected except in P. rugosus. Mass‐specific V˙CO2s of headless harvesters were comparable with published values derived from motionless specimens of other ant species. The mean Q10 for intact ants of all three species was 2.37; for decapitated insects the mean was 2.32. Respiratory water constituted a small (< 5%) fraction of total loss, and we believe that discontinuous ventilation does not act to conserve water in these organisms, although it may serve other functions.
Flight activity of three Spodoptera spp., Spodoptera litura, S. exigua and S. depravata, measured by flight actograph
Authors: Saito Osamu 
Published: March 2003

SummaryFlight activities of three Spodoptera species were measured by the aid of flight actograph: S. litura and S. exuiga being regarded as long‐distance migratory insects, and S. depravata being non‐migratory and diapause‐inducible species. In all species tested, flight activities were observed only in scotophase, males showed far higher activities than females, being several times higher at the time of maximum flight activity, which was observed within 2 days after adult eclosion. Total flight activity in males was highest in S. litura, some being flyable even 12 days after eclosion, followed by S. exigua being one‐third compared to the former species, while in S. depravata flight activity was nearly half of that of the second species and most ceased to fly within a week after eclosion. There occurred species‐specific daily rhythms in flight activity during respective scotophase. In S. litura, both females and males exhibited a peak of flight activity shortly after light‐off and exhibited the second flight activity in late scotophase, the females slightly but the males more actively compared to early scotophase. In S. exigua, both sexes did not respond to light‐off, did not show a peak of flight activity in early scotophase, whereas males, but not females prominently increased activity toward the end of scotophase. In S. depravata, both sexes exhibited a peak of flight activity in early scotophase, and the males revived flight activity, being maximum shortly before light‐on, but the females did not show a clear rhythm in flight activity. These features observed in flight activity were discussed in relation with migratory capability.
Body movements and their role as triggers of heartbeats in pupae of the Colorado potato beetle Leptinotarsa decemlineata
Authors: Kuusik Aare , Tartes Urmas , Vanatoa Alo , Hiiesaar Külli , Metspalu Luule 
Published: March 2003

SummaryRhythmic body movements and their role as triggers of intermittent heartbeats were studied in pupae of Leptinotarsa decemlineata Say. Heartbeats and body movements were recorded simultaneously by means of an optical method (infra‐red cardiography) combined with respirometry. IR‐cardiography allows heartbeats and body movements to be distinguished on the basis of their different rates (40–80 min−1 and 4–8 min−1, respectively) and amplitude.In the mid‐interecdysial period, abdominal movements in the pupae were always accompanied by heart activity beginning after the first 5–12 abdominal strokes. Simultaneous periods of abdominal movements and heartbeats lasted 2–5 min, while the intervening pause ranged from 40 to 72 min at 24°C.Experiments of forced heart activity showed that a slight external tactile stimulus (prodding once with a single hair), applied prior to an expected heartbeat bout, evoked abdominal movements followed soon afterwards by contractions of the dorsal vessel. Repeated prodding with a hair evoked body rotating movements (1–3 strokes) at any time with heartbeats starting at the first movement.We surmise that rhythmic body movements play an active role in the triggering of heart activity in pupae according to the principle of cardiac reflex response. This is a possible mechanism for synchronizing periods of heart activity with periods of rhythmic body movements. Haemolymph circulation in pupae is favoured when heartbeat bouts are accompanied by active body movements.
Divergent nutrition‐related adaptations in two cockroach populations inhabiting different environments
Authors: Mira Alex , Raubenheimer David 
Published: March 2003

Abstract.Developmental, reproductive and size‐related variables were compared between two ecologically different strains of Periplaneta americana (L.). One strain was a laboratory‐reared culture, and the other a feral strain inhabiting an urban environment. The feral population was originally founded by escapees from the culture, but may also include immigrants from other urban populations. Both final‐instar nymphs and adults of the feral insects were heavier than their equivalents from the cultured population, this weight difference being due to a higher capacity for the storage of water and heavier fat‐free carcasses. Feral cockroaches also had heavier oothecae, which contained heavier offspring than those from cultured females. Feral animals had one or two more larval stadia and higher growth rates. Size‐related differences persisted in first and second filial generations reared under laboratory conditions on a nutritionally balanced diet, but were not apparent in first filial insects reared on a vegetable diet. Greater resistance to starvation was found in feral animals, and this was attributed primarily to their larger water stores. Feral animals were found to harbour a higher density of endosymbiotic bacteria in the fat body, which are known to enhance the efficiency of protein utilization. The data suggest that the characteristics of feral animals have been selected in the nutritionally harsh feral environment compared with the more benign culture conditions, with water availability playing a role.
Age‐related decline in stand productivity: the role of structural acclimation under hydraulic constraints
Authors: Magnani F. , Mencuccini M. , Grace J. 
Published: March 2003

ABSTRACTThe decline in above‐ground net primary productivity (Pa) that is usually observed in forest stands has been variously attributed to respiration, nutrient or hydraulic limitations. A novel model is proposed to explain the phenomenon and the co‐occurring changes in the balance between foliage, conducting sapwood and fine roots. The model is based on the hypothesis that a functional homeostasis in water transport is maintained irrespective of age: hydraulic resistances through the plant must be finely tuned to transpiration rates so as to avoid extremely negative water potentials that could result in diffuse xylem embolism and foliage dieback, in agreement with experimental evidence. As the plant grows taller, allocation is predicted to shift from foliage to transport tissues, most notably to fine roots. Higher respiration and fine root turnover would result in the observed decline inPa. The predictions of the model have been compared with experimental data from a chronosequence ofPinus sylvestrisstands. The observed reduction inPais conveniently explained by concurrent modifications in leaf area index and plant structure. Changes in allometry and shoot hydraulic conductance with age are successfully predicted by the principle of functional homeostasis.
Water movement between epidermal cells of barley leaves – a symplastic connection?
Authors: Fricke W. 
Published: March 2003

ABSTRACTUsing the cell‐pressure probe the possibility of symplastic water flow between cells of the upper epidermis of barley leaves was investigated. Cells analysed had either an intact or a more or less damaged cellular environment. Cell damage caused large pressure differentials (0·9 MPa) between damaged and adjacent intact cells. Turgor in cells adjacent to damaged cells decreased significantly. Turgor decreases were the larger the more the adjacent, damaged cell was leaking (decreases by 2·5–4·4%). In cells surrounded by a patch of leaking cells, turgor decreased the most, by 18·1–20·4%. In contrast, half‐times of water exchange (T1/2) of cells were not affected by a damaged cellular environment. Assuming that in the barley leaf epidermis, plasmodesmata close at pressure‐differentials at or exceeding 0·2 MPa as shown for other plant cells (The Plant Journal 2, 741–750; Canadian Journal of Botany 65, 509–511), it is concluded that symplastic water flow contributes insignificantly to water exchange between cells. Mechanical damage to one individual cell is enough to induce significant turgor changes in neighbouring cells.
Water stress‐induced abscisic acid accumulation in relation to reducing agents and sulfhydryl modifiers in maize plant
Authors: Jia W. , Zhang J. 
Published: March 2003

ABSTRACTSignalling process of water stress‐induced abscisic acid (ABA) accumulation was investigated in maize (Zea mays L.) leaf and root tissues. Potent free‐radical scavengers and reducing agents, N‐acetyl cysteine (NAC) and cystein (Cys), significantly inhibited or nearly completely blocked dehydration‐induced ABA accumulation. Dithiothreitol (DTT), a reducing agent but not a free‐radical scavenger, also significantly inhibited such accumulation whereas solely free‐radical scavengers, dimethyl sulphoxide (DMSO) and melatonin (Mela), had no effects. Moreover, water stress‐induced ABA accumulation was not affected either by free radicals, such as superoxide anion and hydrogen peroxide, or by oxidants such as KIO4. These observations suggest that the blocking of water stress‐induced ABA accumulation resulted from the reducing effect, rather than from anything associated with free radicals. The disulphide bond might be crucial to the reactivity of some signal element(s) in the signalling process of water stress‐induced ABA accumulation. To test the hypothesis, we used a sulfhydryl modifier, iodoacetamide (IOA), and found that it nearly totally blocked the water stress‐induced ABA accumulation. Furthermore, an impermeable sulfhydryl modifier, p‐chloromercuriphenylsulphonic acid (PCMBS), could also inhibit the water stress‐induced ABA accumulation in the leaf tissues. These results indicate that water stress‐perception protein(s) or receptor(s) may be located on the plasmalemma and a sulfhydryl group in the extracellular domain is critical to the reactivity of the speculated water stress receptors. Cys, DTT and IOA did not lead to a decrease of the baseline ABA level, i.e. in non‐stressed roots. Result indicates that their blocking of water stress‐induced ABA accumulation occurred upstream of the ABA biosynthesis pathway, i.e. in the signalling process that initiates such accumulation.
Suramin inhibits oxidant signalling in tobacco suspension‐cultured cells
Authors: Miles G. P. , Samuel M. A. , Ellis B. E. 
Published: March 2003

AbstractPlant cells respond to ultraviolet radiation and other oxidant‐generating agents by mobilizing cellular defences, but the signal network linking perception of redox perturbation with defence remains unknown. Irradiation of tobacco suspension‐cultured cells with UVC was found to induce the activation of a specific MAPK46 (salicylic acid‐induced protein kinase) within 1 min. To explore where UVC and other oxidants might initially act to trigger this signal response, we employed suramin, a non‐membrane‐permeable reagent that interferes with membrane receptor‐mediated signalling in mammalian cells. Pre‐treatment of tobacco cells with suramin strongly attenuated the UVC‐induced activation of MAPK46 in a concentration‐dependent manner. Suramin was also able to interdict both ozone‐ and hydrogen peroxide‐induced activation of MAPK46, indicating that reactive oxygen species (ROS) signalling to the MAPK cascade in general may be initiated at the cell membrane, perhaps through oxidative activation of membrane receptors.