bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sex‐ratio bias in an aphid parasitoid‐hyperparasitoid association: a test of two hypotheses
Authors: MACKAUER M. , LARDNER R. M. 
Published: March 2008

Abstract.

We tested the hypothesis that biased sex ratios in the aphidiid parasitoid, Aphidius ervi, are the result of sex‐specific mortality of immatures due to hyperparasitism. The solitary hyperparasitoid, Dendrocerus carpenteri, deposits its eggs on the prepupa or pupa of the primary parasitoid after its pea‐aphid host is mummified.
In dichotomous choice tests, females of D.carpenteri accepted immatures of both sexes of A.ervi with equal frequency. Independent of the sex of the primary parasitoid, the probability of a mummified pea aphid being hyperparasitized did not differ between large (adult at the time of death) and small (fourth nymphal instar) mummies.
As predicted by‘host quality’models of offspring sex allocation, D.carpenteri produced a higher proportion of female than male offspring in large mummies. These laboratory results were supported by field data.
Because hyperparasitism by D.carpenteri is random with regard to host sex, it should have no influence on optimal sex allocation by the primary parasitoid.
Bloodmeal evacuation from the midgut of Glossina pallidipes in relation to tsetse foraging activity and trappabiIity
Authors: MADUBUNYI L. CHUKA 
Published: March 2008

Abstract.

Foraging for bloodmeals is the most frequently recurrent and probably the most targetable of all activities that render tsetse vulnerable to interception with static trapping devices.
Surgical monitoring of the rnidgut every 24 h during three successive days of food deprivation, showed that a full bloodmeal, irrespective of its size or source, vacated the rnidgut of both sexes of Glossina pallidipes Austen in eight progressive stages.
Probing responsiveness in both sexes increased exponentially during the first four stages of their midgut evacuation, reaching a peak between stages 3 and 5. Thereafter it decreased, also exponentially.
Most G.pallidipes caught by NG2G traps baited with cow urine and acetone had midguts in the last three stages (6–8) of bloodmeal evacuation. The same was true of the majority of those that failed to feed on a calf shortly after entrapment.
The implications of the foregoing for tsetse foraging activity and trappability as well as for the potency of cattle urine and acetone as odour‐bait for tsetse are discussed.
Dynamics of parasitism in the organ‐pipe wasp, Trypoxylon politurn: effects of spatial scale on parasitoid functional response
Authors: MOLUMBY ALAN 
Published: March 2008

Abstract.

Life tables and rates of parasitism were tabulated from mud nests built by Trypoxylon politum (Hymenoptera: Sphecidae) at nine different nesting sites from Missouri and Mississippi.
Most developmental mortality occurred either during the first two instars of development, or during the inactive prepupal phase. The majority (76%) of deaths were caused by insect parasitoids and cleptoparasites. Levels of parasitism and survivorship varied among nesting sites, and among locations within the two sites surveyed at a fine spatial scale.
Total developmental mortality, K, was positively associated with the number of hosts (immature T.politum) per site. Within one of two sites sampled at a fine spatial scale, K was negatively associated with the local density of hosts. Levels of total parasitism were positively associated with host population size, and negatively associated with local host density within one of the two sites sampled at a fine spatial scale.
Levels of parasitism by Melittobia (Hymenoptera: Eulophidae) were positively associated with the number of hosts per site, but negatively associated with the local density of hosts within sites. Melittobia parasitism was also negatively associated with the local density of old nesting material within sites.
Parasitism by Melittobia was a function of both the numbers of nests per quadrat and the mean nest size per quadrat at one of the two sites surveyed at a fine scale. At the other site, parasitism by Melittobia was a function of mean nest size per quadrat.
The life cycle and nesting behaviour of T.politum, in relation to the regulation of its numbers, is discussed.
Foraging and courtship behaviour in males of the solitary bee Anthophora plumipes (Hymenoptera: Anthophoridae): thermal physiology and the roles of body size
Authors: STONE GRAHAM N. , LODER PHILIP M. J. , M.BLACKBURN TIM 
Published: March 2008

Abstract.

The effects of climate and body size on male behaviour were examined in the solitary bee Anthophora plumipes (Hymenoptera: Anthophoridae), which shows resource‐based polygyny at floral food sources in Britain in spring.
Larger males are able to fly at lower temperatures than smaller males, and can therefore court females under conditions in which smaller males cannot fly. This is predicted from patterns of endothermic ability at low temperatures already demonstrated within this species.
Video analysis of male competition for opportunities to initiate courtship with tethered females showed that larger males are also competitively superior, and can displace smaller males from favoured flight positions immediately behind females.
The mating system shown by male A plumipes is strongly dependent on male density. At low densities, males show exclusive territoriality at floral sources. As male density increases, this strategy is abandoned in favour of patrolling with considerable spatial overlap between males, and opportunistic Polygyny.
Despite high endothermic abilities, male behaviour is highly dependent on weather, and particularly ambient temperature. Males bask in the early morning and maintain high thoracic temperatures. Temperature data from freshly killed bees show that thoracic warming from solar sources effectively doubles the thermogenic power generated by the bee alone at low ambient temperatures.
Male strategies in A.plumipes are compared to female responses to climate. Having controlled for differences in body size there is no difference in endothermic abilities between the sexes. Males do not, however, fly under conditions in which females of the same size would remain active. These results are discussed in the light of differential dependence of reproductive success on flight activity for the two sexes.
Correlates of male mating success in two natural populations of the damselfly lschnura graellsii (Odonata: Coenagrionidae)
Authors: CORDERO A. 
Published: March 2008

Abstract.

Two natural populations of Ischnura graellsii were studied in north‐west Spain by means of mark‐release‐recapture techniques. Recaptured males were a random sample of the original marked population with regard to date of marking. At O Rosal a greater proportion of young males than old males disappeared after marking; at Lourizán recaptured males were larger than unrecaptured ones.
The number of matings observed in both populations showed great daily variation. Most of the variation is accounted for by climatic variables. Most males (56–65%) and many females (41–45%) were never observed to mate.
Male LMS was highly correlated with lifespan in both populations. At O Rosal, male LMS was also positively correlated with body length, and mated males were larger than unmated males. This surprising result for a non‐territorial species was due to the positive correlation between date of marking and size. There was a positive correlation between body size and mobility for males at O Rosal, but mobility was not correlated with male LMS.
As predicted by sexual selection theory, the standardized variance in male LMS was greater than in female LMS. Variation in mature lifespan explained 16% of variance in male LMS at Lourizán and 28% at O Rosal.
Flexible patch time allocation by the leafminer parasitoid, Opius dimidiatus
Authors: NELSON J. M. , ROITBERG B. D. 
Published: March 2008

Abstract.

The ability to use flexible decision rules can be an advantage to parasitoid females searching for patchily‐distributed hosts. In a series of laboratory experiments the hypothesis that Opius dimidiatus, a solitary parasitoid of the chrysanthemum leafminer (Liriomyza trifolii), adjusts the time she allocates to searching for her larval hosts in response to both patch qualities and experiences with hosts was tested by varying such patch parameters as area, presence of host mines and density of host mines, and by allowing ovipositions and encounters with parasitized hosts.
Though leaf area was not a factor, the presence of host mines in a leaf did increase the time a female O.dimidiatus spent searching, over time spent on unmined leaves.
When host mine density was increased, females responded by increasing their search period in a density‐dependent manner, suggesting a perception of patch quality.
Ovipositions in hosts caused females to reset their‘giving‐up time’(GUT), or increase search intensity, by adding an amount of search time that increased with each successive oviposition. Conversely, encounters with parasitized (unsuitable) hosts incremented the GUT, but by an amount that decreased with each successive encounter.
Nocturnal activity and resource utilization in the aphid hyperparasitoid, Dendrocerus carpenteri
Authors: VOLKL WOLFGANG , KRANZ PETRA 
Published: March 2008

Abstract.

Females of the aphid hyperparasitoid Dendrocerus carpenteri (Curtis) search successfully for hosts during both day and night. Oviposition numbers per host patch did not differ significantly between day and night.
D.carpenteri females also displayed a nocturnal flight activity, showing that they are not only capable of searching on a given host plant but also of dispersing between host plants.
Nocturnal oviposition activity was mainly influenced by egg load. Females with a high egg load laid more eggs at night than females with a comparatively low egg load. Thus, D.carpenteri females may use nocturnal foraging to compensate for the lack of oviposition opportunities during day.
D.carpenteri females which foraged continuously for hosts both day and night (= for 24 h per day) benefitted from an 1.4‐fold increase in lifetime reproductive success when compared to females which foraged only by day (= for 16 h per day).
The benefit of night foraging for this species is a significantly increased reproductive success.
Mode of inheritance of face fly diapause and its correlation with other developmental traits
Authors: KIM Y. , KRAFSUR E.S. , BAILEY T. B. , ZHAO SULING 
Published: March 2008

Abstract.

Adult face flies, Musca autumnalis De Geer, respond to short photoperiods by entering diapause. Diapause responses to different photoperiods at a mean temperature of 17°C varied among seven laboratory face fly strains. Old strains lost much of their diapause responses.
To analyse the nature of diapause inheritance, hybrids and their back‐crosses were made between two strains that showed the greatest difference in diapause introduction at 10:14 h(L:D), and 17°C.
Responses of hybrids to the short photoperiod were intermediate to those of their parents. Joint scaling tests showed that diapause did not fit an additive model and the lack of fit was attributed to incomplete dominance. No cytoplasmic effect was detected, but diapause was partially sex linked.
Diapause heritabilities were 47% and 30% in the broad and narrow senses, respectively.
Estimates of the minimum number of diapause genes suggested a small number.
Developmental rates of egg to adult, ovarian follicle growth, and pterin accumulation were inversely correlated with diapause propensities, suggesting pleiotropy or linkage.
Discriminant conditioning of foragers in the Asian honey bees Apis cerana and A.dorsata
Authors: WELLS HARRINGTON , RATHORE RAM R. S. 
Published: March 2008

Abstract.

Nectivore foraging environments are typically modelled as choices among non‐fluctuating rewards, but in reality they often consist of intermittent daily nectar and pollen sources. Intermittent rewards create two distinct foraging problems for colonial nectivores: re‐recruitment (periodically returning to intermittent rewards) and re‐allocation (finding new rewards).
The role of scent in learning and remembering the locations of discontinuous nectar rewards was examined by testing re‐recruitment efficiency of Apis cerana and A.dorsata to reward‐correlated scents (odour discriminant self‐conditioning). Experiments examined the responses of non‐naive foragers to an odour correlated with prior reward, and to odours not correlated with prior rewards, by placing different scents into a colony and observing the number of bees re‐recruited to a feeding station.
Re‐recruitment of non‐naive foragers in both species was significantly greater in response to the conditioning scent than to the experimental controls. However, species behaviour differed in one aspect; re‐recruited A.cerana foragers landed on the feeding station when unscented reward was offered, whereas re‐recruited A.dorsata foragers returned but would not land without conditioning scent present in the reward.
Acoustically‐orienting parasitoids in calling and silent males of the field cricket Teleogryllus oceanicus
Authors: ZUK MARLENE , SIMMONS LEIGH W. , ROTENBERRY JOHN T. 
Published: March 2008

Abstract.

On three Hawaiian Islands, the introduced Australasian field cricket Teleogryllus oceanicus Le Guillou (Orthoptera: Gryllidae) was found to be attacked by the phonotactic parasitoid tachinid fly, Ormia ochracea Bigot.
Noncalling males occurred with callers in all locations, but silent males were more heavily parasitized than callers.
Body size was unrelated to both calling status and the likelihood of harbouring parasitoid larvae.
An experiment examining the likelihood of calling in the laboratory by males collected as silent or calling individuals showed no difference between the two classes of males, after accounting for parasitoid levels; males harbouring larvae were less likely to call.
Freeze‐protection of overwintering monarch butterflies in Mexico: critical role of the forest as a blanket and an umbrella
Authors: ANDERSON J. B. , BROWER L. P. 
Published: March 2008

Abstract. 1. At their high‐altitude overwintering sites in Mexico, monarch butterflies frequently are subjected to sub‐zero°C temperatures during December‐March. Although monarchs have moderate supercooling ability, two ecological factors strongly influence their capacity to resist freezing: wetting and exposure to the clear night sky.2. As shown in Fig. 2, 50% of a population of butterflies with water on their body surfaces freeze at warmer sub‐zero temperatures (‐4.2°C) compared to butterflies with no water on their bodies (‐7.7°C). 100% mortality occurs, respectively, at −7.7°C and −15°C.3. Comparative measurements of rainfall within a large overwintering colony in Mexico indicated that the intact canopy acts as an umbrella that reduces butterfly wetting during winter storms.4. Variable experimental exposure of butterflies to the clear night sky indicated that openings in the forest canopy increases radiational cooling and causes monarch body temperatures to drop as much as 4°C below ambient air temperature. Monarchs under dense cover had body temperatures approximately the same as the ambient air temperature, but more exposed individuals had body temperatures below ambient in direct proportion to the degree of exposure. Consequently, forest thinning increases the probability that the butterflies will freeze to death.5. Whereas both wetting and exposure are increased by disturbance of the forest canopy, the interaction of these two factors exacerbates freezing mortality during winter storms: 50% of dry and unexposed butterflies froze at −8°C, whereas wetted and fully exposed butterflies froze at only −0.5°C.6. Butterflies inside and on the bottom of the fir bough clusters are better protected from wetting than those on the outside. This supports the hypothesis that the structure of the butterfly clusters has evolved through individual selection to avoid wetting.7. The data strongly reinforce previous evidence that forest thinning should be totally prevented within and adjacent to the overwintering sites in order to minimize both wetting and exposure of the butterflies that synergistically increase winter mortality at the overwintering sites in Mexico.
Magnetic resonance guided focused ultrasound surgery. Ablation of soft tissue at bone–muscle interface in a porcine model
Authors: Kopelman D. , Inbar Y. , Hanannel A. , Pfeffer R. M. , Dogadkin O. , Freundlich D. , Liberman B. , Catane R. 
Published: March 2008

ABSTRACTBackground  Pain management treatments of patients with bone metastases have either efficacy problems or significant side effects. Percutaneous radiofrequency ablation has recently proved to be of palliative value. Magnetic resonance guided focused ultrasound surgery (MRgFUS) uses focused ultrasonic energy to non‐invasively create a heat‐coagulated lesion deep within the body in a controlled, accurate manner. The surgeon can monitor and control energy deposition in real time. This technology represents a potential treatment modality in oncological surgery. We investigated the ability of two MRgFUS methods to accurately and safely target and ablate soft tissue at its interface with bone.Materials and methods  Heat‐ablated lesions were created by MRgFUS at the bone–muscle interface of 15 pigs. Two different methods of energy delivery were used. Temperature rise at the target adjacent to bone was monitored by real time MR thermal images. Results were evaluated by MRI (magnetic resonance imaging), nuclear scanning and by histopathological evaluation.Results  Soft tissue lesion sizes by both methods were in the range of 1–2 cm in diameter. Targeting the focus ‘behind’ the bone, achieved the same result with a single sonication only. Follow up MRI and histopathological examination of all lesions showed focal damage at its interface with bone and localized damage to the outer cortex on the side closer to the targeted tissue. There was no damage to non‐targeted tissue.Conclusion  MRgFUS by both energy deposition methods can be used to produce controlled well‐localized damage to soft tissue in close proximity to bone, with minimal collateral damage.
Classification of chronic kidney disease by estimated glomerular filtration rate
Authors: Marsik C. , Endler G. , Gulesserian T. , Wagner O. F. , Sunder‐Plassmann G. 
Published: March 2008

ABSTRACTBackground  Serum creatinine concentration alone as a marker of kidney function is inadequate. Thus several equations for estimating glomerular filtration rate (eGFR) have been proposed within the last years.Patients and methods  In our study we compared three frequently used equations, the abbreviated modification of diet in renal disease (MDRD) formula, the extended MDRD formula and the recently proposed Mayo clinic equation in a large patient cohort.Results  A total of 244 507 patients attending the Vienna General Hospital were evaluated for their kidney function and three equations for eGFR were compared. The median age of the patients was 51 years (ranging from 18·0 to 102·6 years) with 44·3% males (n = 108 527).We observed a significant increase of patients with eGFR classes four and five (according to Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines) with advanced age. Whereas approximately 1% of patients < 30 years presented with eGFR classes four and five (defined as eGFR < 30 mL min−1 1·73 m−2), this prevalence increased up to ∼12% in patients at the age of 80 years or older. All three equations showed comparable results for eGFR classes four and five. The proportion of patients with mild to moderate impairment of kidney function is higher using both MDRD equations.Conclusions  The MDRD equations (particularly the abbreviated MDRD formula) result in considerably higher rates of eGFR classes two and three compared to the Mayo Clinic equation, while all three were comparable in classes four and five. This should be considered when eGFR is used in the diagnosis of chronic kidney disease.
Alterations of hepatic ATP homeostasis and respiratory chain during development of non‐alcoholic steatohepatitis in a rodent model
Authors: Serviddio G. , Bellanti F. , Tamborra R. , Rollo T. , Romano A. D. , Giudetti A. M. , Capitanio N. , Petrella A. , Vendemiale G. , Altomare E. 
Published: March 2008

ABSTRACTBackground Mitochondrial dysfunction is considered a key player in non‐alcoholic steatohepatitis (NASH) but no data are available on the mitochondrial function and ATP homeostasis in the liver during NASH progression. In the present paper we evaluated the hepatic mitochondrial respiratory chain activity and ATP synthesis in a rodent model of NASH development.Materials and methods Male Wistar rats fed a High Fat/Methionine‐Choline Deficient (MCD) diet to induce NASH or a control diet (SHAM), and sacrificed after 3, 7 and 11 weeks. The oxidative phosphorylation, the F0F1ATPase (ATP synthase) and the ATP content were assessed in liver mitochondria.Results NASH mitochondria exhibited an increased rate of substrate oxidation at 3 weeks, which returned to below the normal level at 7 and 11 weeks, concomitantly with the coupling between the phosphorylation activity and the mitochondrial respiration (ADP/O). Uncoupling of NASH liver mitochondria did not allow the recovery of the maximal respiration rate at 7 and 11 weeks. The ATPase (ATP synthase) activity was similar in NASH and SHAM rats, but the mitochondrial ATP content was significantly lower in NASH livers.Conclusions The loss of hepatic ATP stores is not dependent on the F0F1‐ATPase but resides in the respiratory chain. Dysfunction of both Complex I and II of the mitochondrial respiratory chain during NASH development implies a mitochondrial adaptive mechanism occurring in the early stages of NASH.
The effects of transgalactosylated oligosaccharides on gut flora metabolism in rats associated with a human faecal microflora
Authors: Rowland I.R. , Tanaka R. 
Published: March 2008

The effect on various caecal bacteria and their metabolic activities of feeding diet containing transgalactosylated oligosaccharides (TOS) with or without Bifidobacterium breve (administered in the drinking water) was investigated in rats colonized with a human faecal microflora. TOS (5% w/w in diet) or TOS plus B. breve, given for 4 weeks, induced increases in caecal concentration of total anaerobic bacteria, lactobacilli and bifidobacteria, and decreases in numbers of enterobacteria. Caecal pH was significantly reduced by feeding TOS, as were the activities of β‐glucuronidase and nitrate reductase. In contrast, β‐glucosidase activity was increased in TOS‐fed rats.Dietary TOS was also associated with decreased conversion, by caecal contents, of the dietary carcinogen 2‐amino‐3‐methyl‐3H‐imidazo[4, 5‐f] quinoline (IQ) to its genotoxic 7‐hydroxy derivative.