bluuebunny/crossref_metadata_2025_split huggingface dataset:
l‐Arginine preferentially dilates stenotic segments of coronary arteries thereby increasing coronary flow
Authors: Lauer T. , Kleinbongard P. , Rath J. , Schulz R. , Kelm M. , Rassaf T. 
Published: March 2008

Abstract.Background and objectives.  Oxidized LDL cholesterol and cytokines increase arginase and decrease nitric oxide (NO) synthase expression in human endothelial cells, leading to a decrease in NO production. In arteriosclerotic plaques, characterized by increased oxidized LDL and cytokine levels, a sustained local NO reduction might enhance sensitivity of the downstream guanylyl cyclase system towards an acute NO increase. We tested whether application of the NO synthase substrate l‐arginine (l‐arg, 150 μmol min−1) or the NO donor isosorbide dinitrate (ISDN; 0.3 mg) preferentially dilates stenotic coronary artery segments (CS) subsequently increasing poststenotic coronary blood flow (CBF) in patients with coronary artery disease (CAD).Design, setting and subjects.  Changes in coronary diameter and circumferential surface area were assessed by quantitative coronary angiography (QCA) in a nonstenotic upstream segment, the CS, downstream the CS and in a reference vessel (n = 24). CBF was estimated in a subset of 13 patients by QCA and intracoronary Doppler.Results.  CS ranged from 62% to 89% (77 ± 5%). l‐arg increased minimal luminal diameter of the stenotic segment from 0.98 ± 0.06 to 1.14 ± 0.07 mm (P < 0.05) without affecting other coronary segments. Poststenotic CBF increased by 24 ± 3%. ISDN dilated all segments again with a predominance of CS (25 ± 4%) and increased poststenotic CBF by 38 ± 9%. In a multifactorial anova, a medication with an angiotensin‐converting enzyme inhibitor (decreasing inflammation and radical formation) and a ratio of LDL/HDL <3.5 were predictive for an l‐arg‐induced dilation.Conclusion.  The increase in poststenotic CBF without affecting nondiseased arteries highlights the therapeutic potential of l‐arg in patients with CAD.
The role of pressure in controlling the entry of water into the developing eggs of the Australian plague locust Chortoicetes terminifera (Walker)
Authors: LEES A. D. 
Published: March 2008

AbstractThe normal internal hydrostatic pressure and the additional pressure necessary to rupture the egg shell was measured in the eggs of Chortoicetes terminifera, Newly laid white eggs burst at c 0.15 kg cm‐2, but after external tanning the chorion withstands c 0.5 kg cm‐2 when removed from its tanned foam ‘corset’ and 1.0 kg cm‐2 if left embedded in the egg pod material. Older eggs with formed cuticles often withstand 2.0 kg cm‐2 but yield at rather lower pressures if they develop ‘pin‐holes’. As the OP of the egg contents always exceeds 7.7 kg cm‐2 the rigidity of the wall is clearly insufficient to permit the generation of high hydrostatic pressures capable of preventing water entry during the non‐absorbing phases of development. Real hydrostatic pressures are lower than 0.06 kg cm‐2 in the young intact egg and reach only c 0.5 and 0.3 kg cm‐2, respectively, during the absorptive and post‐absorptive phases of development.Several events contribute to the sigmoid form of the water uptake curve. Water is at first excluded by a permeability barrier associated with the chorion. Absorption is delayed until the yolk is completely enclosed by the serosal cell layer. After undergoing cleavage, the yolk is then rapidly mobilized to furnish precursors for cuticle synthesis; in consequence, the internal OP rises from δ 0.76d̀K to 0.93d̀K despite the massive inflow of water which is governed by the osmotic gradient. At blastokinesis the serosa becomes detached from the cuticle; cuticle deposition and yolk mobilization are halted, the OP falling rapidly to cδT 0.53d̀K. The bulk entry of water then ceases. Any excessive hydrostatic pressures which develop later are relieved by the formation of self‐sealing ‘pin‐holes’.
Proposal for a new term ‘echeme’ to replace ‘chirp’ in animal acoustics
Authors: BROUGHTON W. B. 
Published: March 2008

AbstractThe term ‘chirp’ as defined by Broughton (1952) and varied by him (1963a, b) is shown to be both inadequate and potentially misleading, particularly in the light of the principles of measurement of the time‐parameters of insect song, which are reviewed. It is important to include, in the measured duration of a given element, not only the durations of its constituent sub‐elements plus the intervals between them, but also an estimate of the interval that would have followed the last sub‐element, had the emission been prolonged further.‘Chirp’ should be totally restricted to initial, empirical descriptions of sounds that appear undivided to the human ear (or ultrasonics of corresponding length). For a first‐order assemblage of syllables, the term ‘echeme’ with a highly relevant etymology, is proposed.In early insect‐acoustics studies, Broughton (e.g. 1963a), seeking mainly to follow the admirable German terminology of Faber (e.g. 1953) and Jacobs (e.g. 1953), and to combine it with accepted physical terms, proposed certain English equivalents, many of which (such as ‘pulse’, ‘syllable’, ‘sequence’) have proved adequate in the years since then.The term ‘chirp’, however, had been rather loosely and inappropriately used in still earlier studies (Broughton, 1952, 1953; Chavasse et al., 1954) as the equivalent of Jacobs' Silbe (syllable = sound or ultrasound corresponding to one stroke of the singing apparatus). This was in direct conflict with the dictionary usage of ‘chirp’ as a sound that appears unitary and undivided to the unaided human ear (M. Duijm, personal communication in 1962).This is why, in the 1963 revision, Broughton abandoned the use of chirp as equivalent of Silbe, in favour of the direct translation, syllable; and proposed restricting ‘chirp’ to usage as a term for the first‐stage description of a unitary‐sounding element of an animal emission, regardless of its composition in terms of physical units (pulses) or physiological units (syllables). Thus, the song of Chorthippus brunneus (Thunberg)(Orth., Acrididae) sounds unitary to the human ear, but consists of a rapid series of sounds each corresponding to one stroke of the apparatus: it is therefore, according to the 1963 system, a ‘polysyllabic chirp’ (Fig. 1)‐a chirp that happens to be a first‐order assemblage of syllables. By contrast, the song of Chorthippus parallelus (Zetterstedt) is a clear series of unitary sounds each visibly produced by one movement, and is therefore a ‘sequence’ of ‘monosyllabic chirps’ (Fig. 2).
The aggregation of questing ticks, Rhipicephalus pulchellus, on grass stems, with observations on R.appendiculatus
Authors: BROWNING T. O. 
Published: March 2008

Abstract Rhipicephalus pulchellus was observed to aggregate on the tips of grass stems in the field in Kenya. Laboratory studies of this behaviour, using simulated glass ‘stems’ in sand‐trays, showed that this aggregation was not due to responses to either (a) chemical marks placed on the stems by climbing ticks, or (b) other stimuli transmitted down the stems by ticks already at their tips. Instead, the aggregation on stems appeared to be an adventitious result of the ticks aggregating on the ground (in the lab., under filter paper covering the sand substrate of the apparatus) and then climbing the nearest stem in due course. Briefer, comparative observations on R. appendiculatus indicated that it was much more mobile on the stems, spending less time at their tips, and not obviously aggregating.
Range of corixid sound signals in the biotope
Authors: THEISS JOACHIM , PRAGER JOACHIM 
Published: March 2008

ABSTRACT. The propagation of sound in the frequency band (2–12 kHz) used by the Corixidae was measured in two shallow natural ponds. At distances of more than 1 m from the shore the water was at least O.4 m deep. The first pond was eutrophic and contained no plants. The spread of sound into the open water obeyed approximately the geometric attenuation of the sound pressure level (SPL); a loss of 6dB for each doubling of the distance from the point sound source. Near the shore the attenuation was considerably greater, especially for low frequencies; for a 2 kHz signal the damping of the SPL was c. 40–50 dB/m.The second pond had dense plant growth, and the sound attenuation depended strongly on the photosynthetic activity of the waterplants. Measurements in winter, with an overcast sky, revealed only a slight damping effect of the plants for a 10kHz test signal. During intense sunlight in summer, however, in addition to the geometric attenuation the damping effect of the plants over a distance of O.5 m was 50 dB for a 2 kHz signal and 80 dB for 10 kHz. This effect was due to gas bubbles produced during intense photosynthesis.Song A of Corixa dentipes Thms. (Heteroptera) males elicits usually a response by male conspecifics. The threshold SPL for this response was measured to be c. 40 dB lower than the SPL at a distance of O.1 m from a stridulating animal. From the measurements of sound propagation it follows, therefore, that the effective range of Song A in the most favourable case is at least 10m, though in a pond overgrown with plants it can be less than O.4 m.
Influence of photoperiod on low temperature acclimation for cold‐hardiness in Drosophila auraria
Authors: HIGUCHI CHIZUKO , KIMURA MASAHITO T. 
Published: March 2008

ABSTRACT. Imagines of Drosophila auraria Peng, a reproductive diapause species, developed cold‐hardiness at low temperatures to a greater extent when exposed to a diapause‐inducing photoperiod (LD10:14 h) than when exposed to a diapause‐preventing photoperiod (LD 16:8h). Imagines kept at 18°C, which was the temperature at which they were reared to eclosion, did not survive a test exposure to ‐5°C for 8 days regardless of age or photoperiod. When transferred to 10 or 5°C, either from eclosion or from 8 days after eclosion, the survival rate, on testing, rose with time since transfer and rose faster and higher with a photoperiod of LD 10:14h than with LD16:8h. Flies transferred to 15°C only showed improved ability to survive the test if they were kept in LD 10:14h. When cultured at 18°C to the age of 8 days after eclosion, diapause was terminated in about 30% of females even at LD 10:14h. In these post‐diapause females the ability to develop cold‐hardiness at lower temperatures was somewhat less than in the diapausing females, but apparently greater than in the non‐diapause females. These results suggest that the physiological mechanism which promotes cold‐hardiness under a diapause‐inducing photoperiod is not directly linked to the process causing reproductive diapause.In Sapporo, flies from a natural population became tolerant to cold in October when they entered diapause and daily mean temperature fell below 15°C and the light/dark cycle fell below LD 12:12h.
Effects of wing‐pad removal and corpus allatum implantation on development of wings, flight muscles, and related structures in the striped ground cricket, Allonemobius fasciatus
Authors: TANAKA SEIJI 
Published: March 2008

ABSTRACT. Removal of a hindwing pad from late instar nymphs of the striped ground cricket, Allonemobius fasciatus DeGeer (Gryllidae) inhibits the formation of long‐winged adults. All nymphs become short‐winged when their hindwing pad is removed during the sixth (penultimate) instar or during the first 2 days of the seventh instar. When a hindwing pad is removed on day 4 of the seventh instar or later, there is no effect on wing development and at least 50% of the crickets emerge as long‐winged adults as in controls.The period sensitive for removal of a hindwing pad varies among different structures, e.g. elytra, hindwings, flight muscles, and the acrotergite of the first abdominal segment. As a result, some intermediate forms are produced when a hindwing pad is removed in the middle of the seventh instar.Implantation of corpora allata (CA) into late instar nymphs also inhibits formation of long‐winged adults. When CA are implanted on day 2 or 3 of the seventh instar, some of the resulting adults have abnormally short elytra. Implantation of CA at an earlier stage produces supernumerary (eighth instar) nymphs.
Anemotactic orientation of gypsy moth males and its modification by the attractant pheromone (+)‐disparlure during walking
Authors: PREISS R. , KRAMER E. 
Published: March 2008

ABSTRACT. Tracks of dewinged gypsy moth males, Lymantria dispar L. (Lymantriidae), walking upwind in an airstream without pheromone consist of marked alternations between more or less straight upwind segments, partly with an arcadic structure, and twisted segments. This apparently complicated behaviour can, however, simply be explained by a superposition of noise and two turning commands: an upwind turning tendency, derived from the anemoreceptive system, which represents an average of the moth's angular positions over a period of time; and an internal turning tendency which consists of strong but brief bursts. These bursts are produced intermittently; successive bursts do not necessarily alternate polarity. Amputation of one antenna increases the probability of bursts towards the amputated side; therefore a separate burst source is postulated for each antenna. In the presence of the attractant pheromone (+)‐disparlure, the anemotactic signal is weighted higher; twisted segments are, therefore, less pronounced.There is a chemotropotactical component involved in the male's orientation. The tropotactical signal, dependent on the difference of odour concentration perceived by the left and right antenna, competes with the upwind turning tendency.
Volatile spider‐mite pheromone and host‐plant kairomone, involved in spaced‐out gregariousness in the spider mite Tetranychus urticae
Authors: DICKE MARCEL 
Published: March 2008

ABSTRACT. From the host plant‐spider mite complex Phaseolus lunatus—Tetranychus urticae Koch a volatile chemical is emitted that acts as a kairomone for the predatory mite Phytoseiulus persimilis Athias‐Henriot (Sabelis et al., 1984a). This kairomone is apparently a byproduct of a vital physiological process and/or it has a function in the biology of the spider mite as well.The spider mite—host plant complex also emits a volatile spider‐mite dispersing pheromone. This is shown in the present study where spider mites were introduced into an odour patch on a horizontal screen in a vertical airflow olfactometer. When spider‐mite infested leaves of Lima bean are offered, the spider mites walk mainly straight and soon reach the edge of the screen. On the other hand, when clean Lima bean leaves are offered, the mites walk tortuously most of the time and reach the edge of the screen much later. Artificially damaged plants elicit the same response as undamaged plants. Differences in spider‐mite behaviour are observed in the vertical airflow olfactometer when odour of either clean or spider‐mite infested leaves is offered. A comparison of the behaviour in these two situations with that when no odour was offered suggests that Lima bean leaves emit a volatile kairomone that activates T. urticae and makes them return after losing the stimulus. A Y‐tube olfactometer experiment confirms the existence of this kairomone.At a low ratio of dispersing pheromone to plant kairomone, the spider mites behave as if only kairomone is present, walking mainly tortuously. At a high ratio they disperse. No aggregation‐pheromonal effect is observed.The possibility that the spider‐mite dispersing pheromone acts as a kairomone for P. persimilis is discussed.
Age‐dependent responses of last instar larvae of Spodoptera mauritia to precocene II
Authors: SANTHA P. C. , NAIR V. S. K. 
Published: March 2008

ABSTRACT. Last instar larvae of Spodoptera mauritia Boisd. (Lepidoptera: Noctuidae) of various ages were treated with a single dose of 80 μg or 160 μg of precocene II (PII) and the effects of larval—pupal transformation were studied. Final instar (sixth) larvae treated on day 0, 1 or 2 with 80 μg P II showed a high mortality; P II treatment during subsequent days of this stadium showed a diminishing tendency for mortality. P II prolonged the larval—pupal period in all larvae but the effect was somewhat reduced in the mid‐stadium.Treatments of 160μg P II to 0‐day‐old, 1‐day‐old, 2‐day‐old and 3‐day‐old larvae were highly toxic. Treatments of 4‐day‐old and 5‐day‐old larvae with 160 μg P II delayed pupation by 1 day, but in addition the larvae often moulted into larval—pupal intermediates. Co‐application of 50μg juvenile hormone analogue (ZR 512) with 160 μg P II restored both normal morphogenesis and a normally‐timed moult.
The effect of adult feeding on lipid and protein reserves in African armyworm, Spodoptera exempta, moths before and during reproduction
Authors: GUNN A. , GATEHOUSE A. G. 
Published: March 2008

ABSTRACT. Newly‐emerged Spodoptera exempta (Walker) (Lepidoptera: Noctuidae) moths contain high levels of lipid held largely in the abdominal fat body, the quantity depending on the larval feeding conditions. There is a positive relationship between weight‐related lipid content and moth weight, which is consistent for female but not for male moths, suggesting that larval feeding conditions producing large individuals allow the accumulation of quantitatively disproportionate lipid reserves. Male and female moths have comparable levels of abdominal protein.Changes in the water content in starved moths or ones provided with distilled water or sucrose solution show that while starved individuals die rapidly from desiccation, water‐fed moths regulate their water contents between narrow limits which are higher for females than for males. Sucrose‐fed moths maintain higher, more variable water contents probably due to the phagostimulatory effect of the sugar.Reproducing and unmated moths are able to supplement their lipid and, to a lesser extent, their protein reserves following carbohydrate uptake.During both larval and early adult stages, the capacity to accumulate lipid reserves in excess of those apparently required for reproduction, suggests that these reserves also provide the main fuel for the prolonged flights of which migratory individuals are known to be capable.
The combined effect of photoperiod and temperature on the calling behaviour of the true army worm,Pseudaletia unipuncta
Authors: DELISLE JOHANNE , McNEIL JEREMY N. 
Published: March 2008

ABSTRACT.Pseudaletia unipuncta(Haw.) (Lepidoptera: Noctuidae) virgin females, maintained at either 10 or 25d̀C under LD 12:12 or 16:8 h, started calling at different ages. For a given photoperiod, calling was initiated 11 days later at 10d̀C than at 25d̀C, while for a given temperature, calling at LD 12:12 h was 3–4 days later than at LD 16:8 h. At 10d̀C 50.8% of females did not call within 35 days at LD 12:12 h compared with 30.8% at LD 16:8 h. Calling started earlier in the scotophase at 10d̀C than at 25d̀C and at LD 16:8 h than at LD 12:12 h. Under all treatments calling generally advanced on successive nights. The time elapsed between the mean onset time of calling and the mid‐scotophase was relatively constant under both photoperiod conditions at 25d̀C, but at 10d̀C was more variable. The mean time spent calling increased significantly with calling age but did not differ significantly between the four experimental conditions tested.Older (15 days) females transferred from 10d̀C, LD 16:8 h to 25d̀C at either LD 163 or 12:12 h, required less time to initiate calling than younger (5 days) ones. Those transferred from 10d̀C, LD 12:12 h took the same time, regardless of their age at the time of the transfer. Females experiencing either a decrease or increase in daylength as well as a temperature increase, required respectively more or less time to initiate calling, compared with individuals that only experienced an increase in temperature.If temperature was the only parameter changed females that initiated calling soon after the transfer immediately adjusted their calling periodicity to prevailing conditions. When both temperature and photoperiod were altered, it took several days before calling periodicity adjusted to the new regime. The ecological implications of temperature and photoperiodic conditions on the possible autumn migration ofP. unipunctaare discussed.
Relative air humidity influences the function of the tarsal chemoreceptor cells of the cherry fruit fly (Rhagoletis cerasi)
Authors: STÄDLER ERICH , SCHÖNI RETO , KOZLOWSKI MAREK W. 
Published: March 2008

ABSTRACT. Electrophysiological recordings from the tarsal D‐sensilla of mature, 5–7‐day‐old female European cherry fruit fly (Rhagoletis cerasi L.) revealed that a large proportion of sensilla showed no sensory activity in response to stimulation with the oviposition deterring pheromone (‘ODP’) or sucrose. In contrast, good recordings were obtained from almost all sensilla in freshly emerged, 1‐day‐old flies. Ageing, nutritional state and contamination were excluded as possible major factors influencing the responsiveness of the D‐sensilla. The study of the variability in responsiveness of the sensilla of 1‐day‐old flies among different tarsomers, among tarsi of the same individual and among individuals, revealed that the major source of variability was among individuals.Individual flies were also affected by the humidity in the holding cages: relative air humidity of less then 75% for 4–6 days was shown to reduce the number of D‐sensilla giving recordings with a good signal‐to‐noise ratio. The D‐sensilla on the most distal tarsomers were affected most by the reduced (30–55% r. h.) air humidity. Flies which had contact with plant leaves showed less reduction in responsiveness at low air humidity (40% r. h.) then flies without leaf contact.
Circadian timing of cricket calling song: a clock persisting from nymphs to adults
Authors: WIEDENMANN GOTTFRIED 
Published: March 2008

ABSTRACT. Male Australian field crickets (Teleogryllus commodus, Walker) reared in LD 12:12 h were transferred to LL at different developmental stages and the timing of their circadian calling song rhythm was analysed in regard to the previous zeitgeber. The phase settings for the onset and end of activity were similar in crickets experiencing the LD/LL transition: (i) 3–52 days after the final moult, (ii) within 24 h before the final moult, or (iii) 1–10 days before the final moult. For all groups the results reveal entrainment of the circadian mechanism at the last LD, thus excluding age‐related differences. The rhythms of crickets, transferred from LD to LL as larval instars and also exposed to a reduced temperature (5–8oC) during their last night, were delayed by about 11 h, an effect similar to that in adult crickets after a comparable cold exposure (Loher & Wiedenmann, 1981).The results are interpreted showing that the circadian control of (the adult's) calling song already functions in the previous (non‐singing) larval stages. Since the rhythmicity continued through moults and sexual maturation, it is concluded that the control centres regulating those physiological processes (e.g. pars intercerebralis, corpora allata) are not essential to the basic circadian mechanism.