bluuebunny/crossref_metadata_2025 huggingface dataset:
Responses of Male and Female Black Grouse to Male Vocal Display
Authors: Hovi Matti , Alatalo Rauno V. , Halonen Matti , Lundberg Arne
Published: May 2010

The evolution of leks may be explained by several hypotheses. The ‘female preference’ hypothesis, which states that females favour males that have aggregated, has recently gained some empirical support. Low‐quality, unattractive males may, however, settle near attractive males, as predicted by the ‘hotshot’ hypothesis. We tested whether black grouse Tetrao tetrix females use auditory cues to find the preferred leks, and whether males respond to vocal display emitted on leks. We conducted a playback experiment with male vocal display (rookooing) on leks, where the visiting females and displaying males were counted. The number of males tended to increase more on playback leks. Specifically, the number of 1‐year‐old males was greater on playback sites than on control sites. Also, the number of females, in relation to the lek size before the start of the experiment tended to increase. In addition, we used aviary playback trials to test whether females distinguish between single‐male and multi‐male displays. In a choice test, females showed greater preference for the ‘multi‐male’ tape. The tendency for increased male numbers on playback leks resulted from increased visits of young, mobile males which were attracted to leks that they perceived to be large. This suggests a ‘hotshot’‐type mechanism in the settlement of young males. Because females also responded to the supplemented auditory advertisement, or directly to the increased number of males, the ‘female preference’ hypothesis is also supported. Females may, at least in part, base their decision of which lek to visit on auditory cues, but visual contact to males may be also needed.
Rattling Behavior of Prairie Rattlesnakes (Crotalus viridis viridis, Viperidae) in Relation to Sex, Reproductive Status, Body Size, and Body Temperature
Authors: Kissner Kelley J. , Forbes Mark R. , Secoy Diane M.
Published: May 2010

We examined whether sex, reproductive status, body size, or body temperature of prairie rattlesnakes (Crotalus viridis viridis) was related to when snakes rattled in response to an approaching observer. We found that gravid females allowed significantly closer approaches than males, suggesting that females relied on crypsis to avoid predation, possibly because pregnancy constrained their locomotive ability. Smaller snakes allowed significantly closer approaches than did larger snakes. Smaller snakes may be more cryptic or slower, which may influence their waiting to rattle until the observer was close. Overall, we found no consistent relationship between the distance from the observer that a snake rattled and its body temperature. However, cooler gravid females allowed closer approaches by the observer than did warmer gravid females. In summary, reproductive status, body size, and body temperature appear to influence the costs and benefits of crypsis vs. active defense of rattlesnakes.
Do Reproductive Status and Lamb Gender Affect the Foraging Behavior of Bighorn Ewes?
Authors: Ruckstuhl Kathreen E. , Festa‐Bianchet Marco
Published: May 2010

In female ungulates lactation carries a high energetic cost and mothers often devote more care to sons than to daughters. The aims of this study were to determine whether lactating bighorn ewes have higher foraging time, bite rate or selectivity of forage than barren ewes and whether reproductive status affects migration patterns. Ewes with male lambs were predicted to spend more time foraging and to have a higher bite rate than ewes with female lambs. There were no differences in foraging behavior according to ewe reproductive status from April to August. In September‐November lactating ewes had a higher bite rate and spent more time foraging than nonlactating ewes but lamb gender did not affect foraging behavior. Lactating ewes gained less weight than nonlactating ones until mid‐August; from mid‐August to late September mass gain was similar for both groups of ewes. Nonlactating ewes spent more time standing but reproductive status did not affect vigilance behavior or step rate while foraging. Ewes with lambs did not differ from nonlactating ewes in step rate. Pregnant ewes migrated earlier than barren ewes to alpine areas in spring. By so doing they abandoned areas with good quality forage presumably to give birth in areas safer from predation. All ewes spent most of the summer in the alpine range but nonlactating ewes returned to the winter range earlier than lactating ewes, probably to profit from the abundant forage there.
Field Response of Tadpoles to Conspecific and Heterospecific Alarm
Authors: Adams Michael J. , Claeson Shannon
Published: May 2010

Many organisms use chemical cues from a variety of sources to mediate predator avoidance. Response to heterospecific alarm cues has been demonstrated for tadpoles within but not among taxa and alarm response behavior has seldom been examined under field conditions. This study examined the response of three sympatric amphibian larvae and predaceous larval Dytiscus sp. (diving beetle) to damage‐release signals in natural ponds by using capture rates from treated funnel traps as an index of larval behavior. Hyla regilla (Pacific tree frog) tadpoles avoided traps treated with either crushed conspecifics or with Rana aurora (red‐legged frog) tadpoles but the larger ranids and Ambystoma macrodactylum (long‐toed salamander) did not respond to either treatment. H. regilla tadpoles were likely susceptible to any potential predators of ranid tadpoles in these ponds and this result is consistent with the hypothesis that a response to heterospecific alarm occurs in sympatric prey with shared predators.
Vibration Signal Behavior of Waggle‐dancers in Swarms of the Honey Bee, Apis mellifera (Hymenoptera: Apidae)
Authors: Schneider S. S. , Visscher P. K. , Camazine S.
Published: May 2010

We hypothesize two functions of the vibration signal (dorsal ventral abdominal vibration = DVAV) during swarming in honey bees: 1. it enhances recruitment to the specific sites advertised by the waggle dancers which also perform the vibration signal; and 2. it acts as a nonspecific modulatory signal to stimulate activity in other bees. The stimulation of activity invoked by the second hypothesis might include increasing nest‐site scouting and dance following early in the house‐hunting process or rousing quiescent bees to prepare them for lift‐off late in the process, or both. In studies of neotropical African bee swarms in Costa Rica and European bees in California we tested these hypotheses by looking for associations between production of vibration signals by nest‐site recruiters and site attractiveness (indicated by which site was ultimately chosen and by distance from the swarm since swarms may have a distance preference). Overall, bees dancing for the chosen sites performed vibration signals to the same extent as those dancing for the other sites. There were no distance differences between sites whose scouts did and did not vibrate other bees. These results are inconsistent with the hypothesis that the vibration signal enhances recruitment to especially high quality sites and they support the hypothesis that it plays a general excitatory role in the context of house hunting by swarming bees.
A Functionally Equivalent Artificial Neural Network Model of the Prey Orientation Behavior of Waterstriders (Gerridae)
Authors: Snyder Michael R.
Published: May 2010

Waterstriders, a family (Heteroptera, Gerridae) of predacious insects, orient toward the source of water surface vibrations. We describe an artificial neural network that simulates a waterstrider's discrete rotational movement towards a prey item and compare the results to published data. A back‐propagation network with six input units, each corresponding to a vibration receptor on a leg of the waterstrider, and two output units corresponding to the elicited angle of rotation, was used. The network was trained with a full complement of receptors to rotate towards the point source of a surface vibration. When the network was tested with all receptors present, a linear relationship was found between the desired and obtained rotational angles. Lesioning of one or two receptors resulted in marked deviation from linearity within the angular range of detection corresponding to that of the amputated receptor(s), while amputation of three receptors resulted in the network rotating contralaterally to all vibrations originating ipsolaterally to the lesioned side. All trials produced results that corresponded qualitatively to published behavioral data.
Patch Exploitation, Patch‐leaving and Pre‐emptive Patch Defence in the Parasitoid Wasp Trissolcus basalis (Insecta: Scelionidae)
Authors: Field Scott A.
Published: May 2010

Female parasitoids forage for host resources essential to the development of their offspring, so patch exploitation decisions have a direct influence on their fitness. This paper analyses the patch exploitation behaviour and patch‐leaving decisions of the parasitoid wasp Trissolcus basalis (Hymenoptera: Scelionidae), when searching alone on patches of host eggs in the laboratory. Oviposition behaviour was examined in detail and the temporal and sequential structure of patch exploitation was analysed. Time inhomogeneities representing major behavioural change points during patch visits were identified, and the behavioural sequence within homogeneous periods was summarised. As the patch neared full depletion, wasps switched from a repetitive cycle of host examination and oviposition to a ‘leaving routine’, in which they alternated between searching on and off the patch, before abruptly leaving it. Despite the absence of competitors, females remained on the patch for up to 5 h after initiating the leaving routine, and periodically interrupted it to engage in bouts of active patch defence. Such pre‐emptive patch defence was more pronounced when the patch was larger and the resource value therefore greater. This unique patch‐leaving strategy is interpreted as an adaptation to high levels of resource competition and the consequent risk of losing offspring through superparasitism by competitors.
Use of Landmarks in Three Species of Food‐storing Corvids
Authors: Gould‐Beierle Kristy L. , Kamil Alan C.
Published: May 2010

The use of landmarks by Clark's nutcrackers (Nucifraga columbiana), pinyon jays (Gymnorbinus cyanocepbalus), and Western scrub jays (Apbelocoma coerulescens) was investigated in three experiments. In the first experiment, birds were trained to find a hidden food reward beneath wood chips near a plastic landmark located 20 cm from one edge of a stationary tray. During unrewarded test trials, all species displaced their searching in response to movement of the landmark in both parallel and perpendicular directions; however, searching was displaced significantly more in the parallel direction. In a second experiment, the landmark was removed with the tray stationary or shifted. When the tray was shifted, all species responded by searching relative to the shifted tray. This indicates that the global (room) cues were not being used as salient landmarks. In the third experiment, the tray was placed in different positions for each trial, making global cues unreliable. As in experiment 1, all species displaced their searching in response to parallel and perpendicular movement of the landmark, with movement being similar in both directions. These results indicate no species differences on this landmark‐use task.
Mounting Interactions between Female Japanese Macaques: Testing the Influence of Dominance and Aggression
Authors: Vasey Paul L. , Chapais Bernard , Gauthier Carole
Published: May 2010

The goal of the work reported here was to determine whether female Japanese macaques (Macaca fuscata) participated in same‐sex mounting interactions during homosexual consortships to communicate about asymmetries in their dominance relationships and to reduce aggression. Focal data were collected during 21 homosexual consortships involving 14 females living in a captive, mixed‐sex group of 37 individuals. We identified eight types of mounts, one solicitation used specifically to request to mount (hands‐on‐hindquarters solicitation), two solicitations used specifically to request to be mounted (hindquarter and back presentations), and one behavior employed to facilitate mounts‐in‐progress (clasping). We tested whether dominant consort partners (1) mounted more and (2) requested to mount more than their subordinate partners and whether subordinate consort partners (1) requested to be mounted more and (2) facilitated mounts‐in‐progress more than their dominant partners. Finally, we examined whether mounting was temporally linked to the onset of aggressive interactions between consort partners and whether it functioned to defuse incipient aggression. None of these predictions was supported. All types of mounts, mount solicitations, and clasping occurred bi‐directionally within consort dyads. Mutual sexual attraction and gratification provided the proximate motivation for these mounting interactions and, in turn, for the formation and maintenance of their homosexual consortships.
A Technique for Quantitative Description of Aggression‐produced Social Systems
Authors: Lott Dale F. , North Gerry J.
Published: May 2010

We describe a technique for the quantitative description of social systems produced by aggressive interactions between individuals. The assumption underlying the technique is that individuals often employ one or both of two different strategies to gain access to resources. One strategy is to use an established relationship to claim resources wherever they are found (dominance); the other is to exclude competitors from resources in a specific area (territoriality). Our technique allows us to quantify the degree to which the behavioral dimension of each of these strategies is manifested by each individual and also by the whole set of interacting individuals. It will be possible to correlate the quantified social system variables generated by this approach with quantified ecological variables, such as population density and abundance of food, thus contributing to the development of a more rigorous behavioral ecology.

We illustrate this method with quantitative descriptions of variation in juvenile rainbow trout (Oncorbyn‐cus mykiss) correlated with variation in population density and stream flow velocity.
Long‐distance Homing Ability inDasypoda altercator(Hymenoptera, Melittidae)
Authors: Chmurzyński Jerzy A. , Kieruzel Maria , Krzysztofiak Anna , Krzysztofiak Lech
Published: May 2010

Homing rates and initial orientations after release from different directions were investigated in the solitary beeDasypoda altercator.Homing rates and the proportion of individuals returning on the day of release declined with distance, implying that homing from greater distances is not based solely on the use of landmarks. A long duration of return (often not on the same day) and high efficiency of homing (four bees out of 10 returned from a 4 km distance over the lake), as well as an increase in average return speed ≅ 10 m/min) with distance of bees homing on the same day suggest that homing is also not based upon radial scatter as the sole tactic. This is supported by the observation that the initial orientations of the bees were not equally probable. Departures towards the sun greatly exceeded those away from the sun and the bees also tended to depart in cardinal geographical (or geomagnetic) directions, preferring meridional directions (especially southward) to parallel ones (of which east was preferred). Departure directions did not depend on wind direction but did depend, to some extent, on the landscape features of release sites. However, bees neither tended to depart in the direction of the nest, nor did homing success correlate with the direction of departure in relation to that of the nest.
Age and Behavior of Honey Bees, Apis mellifera (Hymenoptera: Apidae), that Perform Vibration Signals on Workers
Authors: Painter‐Kurt S. , Schneider S. S.
Published: May 2010

The vibration signal is one of the most commonly occurring communication displays in honey bee (Apis mellifera) colonies. It may function in a ‘modulatory’ manner, because it causes a nonspecific increase in activity that enhances a variety of behaviors depending upon the age and caste of the recipient. We examined honey bee workers that performed vibration signals on other workers in three observation hives, each containing a population of marked bees of known age. In all three colonies, the mean age of the first performance of the vibration signal was significantly different from the mean age at which workers first performed waggle dances, carried pollen loads, or attended the queen. However, workers of all ages, except those less than 3 d old, could perform vibration signals. In older workers of foraging age, signal performance was most closely associated with recent foraging success. Younger workers that vibrated did not appear to be early‐maturing foragers and thus their signals were probably not influenced by food collection. Rather, for these preforaging‐age workers, signal performance was associated more with periods of orientation flight, during which younger bees learn the location of the nest and surrounding landmarks. Thus, the vibration signal may be triggered by different stimuli in different worker age classes. Because it elicits a general increase in activity in all recipients, the signal may help adjust many different colony behaviors simultancously to changes in foraging success and colony development.
Impact of Social Ties on Dispersal, Reproduction and Dominance in Feral House Mice (Mus musculus domesticus)
Authors: Gerlach Gabriele
Published: May 2010

The existence of a relationship between the social ties an individual has to other family members and its further role within the family was tested in feral house mice (Mus musculus domesticus), according to the ‘Social cohesions hypothesis’. It is predicted by the hypothesis that individuals not forming strong social ties are the first who emigrate.

House mice were studied using a population cage system that allowed continuous observation of individually marked animals. Data on time staying with other animals (social ties), aggressive interactions, body weight, reproduction, and emigration were collected daily. The results may be summarized as follows:

Male emigrants were less integrated in cohorts of male littermates compared with their brothers of the same age. These male cohorts appeared to protect single males from attacks by the dominant male. No difference could be observed in social ties to other family members.

After weaning, there was no difference in social ties of male and female offspring. However, after sexual maturation social ties of males decreased significantly while those of females remained almost constant.

Female emigrants showed the same intensity of social ties as their resident sisters.

No difference could be found between social ties of females becoming pregnant and their nonreproductive sisters of the same age. Reproduction or reproductive suppression could not be explained by having more or less contact with other reproductive females.

Dominant males spent least of all time with other family members.

The social cohesions hypothesis has to be rejected in analysing proximate causes of emigration. In house mice, male emigration was caused by aggression of the dominant male in competition for the top rank within the group. This was enhanced by a lower integration in the group of same‐aged brothers but is not related to a lack of integration into the family.
Quantifying Predation Risk for Refuging Animals: A Case Study with Golden Marmots
Authors: Blumstein Daniel T.
Published: May 2010

Although a variety of behaviors expose animals to some risk of predation, there is no accepted way to compare their relative risk. For animals that retreat to refugia when alarmed by predators, the proportion of time devoted to each out‐of‐refuge behavior multiplied by the total time required to return to a refuge can be used to compare a behavior's relative predation risk. Total time to return to a refuge is a function of both response time ‐ the time required to respond to an increased risk of predation — and travel time — the time required to flee to a refuge once alarmed. Quantifying these components can illustrate how animals minimize exposure to predators. Golden marmots (Marmota caudata aurea) were a refuging prey species used to examine the utility of this measure and to understand how marmots minimized their risk of exposure to predation. Golden marmots devoted different amounts of time to looking, foraging, self‐grooming, and playing. To estimate the behavior‐specific time required to return to refugia, the location of different activities was noted and a behavior‐specific travel time was calculated. Alarm calls were played back to marmots engaged in different behaviors to determine, in a standardized manner, if there were behavior‐specific response times. Marmots appeared to minimize their predation risk by performing most behaviors close to refugia. Results suggest that foraging was the riskiest behavior, largely because marmots foraged far from refugia and spent about 30% of their time foraging. While sample sizes were small, results also suggested that play, a rare adult behavior, exposed animals to predation because of a relatively long response time.
The Effect of Feeding History on Prey Capture Behaviour in the Orbweb Spider Argiope keyserlingi Karsch (Araneae: Araneidae)
Authors: Herberstein Marie E. , Abernethy Kirsten E. , Backhouse Kelly , Bradford Heidi , de Crespigny Fleur E. , Luckock Peter R. , Elgar Mark A.
Published: May 2010

The prey capture behaviour of the orb‐web spider Argiope keyserlingi Karsch was examined experimentally by subjecting spiders to two different feeding regimes (food deprived and food satiated) and three types of prey: Drosophila, blowflies (Lucilia cuprina) and bees (Apis mellifera). The attack behaviour of the spiders was influenced by both their foraging history and the type of prey. Food deprived spiders attacked Drosophila and bees more frequently than food satiated spiders, and food satiated spiders travelled more slowly to any of the prey types than food deprived spiders. Furthermore, Drosophila were never wrapped in silk but only grasped with the chelicerae, whereas both blowflies and bees were always wrapped. This provides experimental confirmation that feeding history affects the decision of orb‐web spiders to accept or reject any given prey.
The Effect of Queen Number on Nestmate Discrimination in the Facultatively Polygynous Ant Pseudomyrmex pallidus (Hymenoptera: Formicidae)
Authors: Starks Philip T. , Watson Rebecca E. , Dipaola Matthew J. , Dipaola Christian P.
Published: May 2010

We present evidence indicating that the level of nestmate discrimination in the facultatively polygynous ant Pseudomyrmex pallidus varies predictably with the number of queens in the colony. P. pallidus workers were introduced into observation arenas in either nestmate or non‐nestmate pairs. During the 5‐min period immediately following the first contact between test ants, all interactions and relative distances were recorded. Aggression between non‐nestmates was negatively correlated with the number of queens in the colony and distance between nestmates was positively correlated. These results are consistent with predictions of Reeve's (1989) optimal acceptance threshold model.
Experimental Investigation of the Mechanism of Reproductive Differentiation in the Queenless Ant, Diacamma sp., from Japan
Authors: Tsuji Kazuki , Peeters Christian , Hölldobler Bert
Published: May 2010

We test two hypotheses about regulation of the reproductive division of labour in the permanently queenless ponerine ant, Diacamma sp., from Japan. All workers emerge with gemmae (tiny innervated thoracic appendages), but only one individual keeps them in each colony, and she is the only mated reproductive worker (gamergate). The gemmae of all other workers are mutilated by the gamergate soon after their emergence, and they can never mate. In the presence of gamergate, mutilated workers have inactive ovaries and do not behave aggressively. Two possible consequences of mutilation are: 1. olfactory signal — a pheromone inhibiting the oogenesis of mutilated workers is no longer released by the gemmae; and 2. endocrine degeneration of its afferent neuronal connections interferes reproductive physiology of a gamergate. Gemmae of gamergates were coated with shellac (to prevent pheromone emission) or removed, and over three weeks we studied any changes in ovarian activity of the gamergates as well as nestmate workers. Coating of gemmae did not elicit worker oviposition, suggesting that gemmae pheromones do not have a regulatory function. Experimental mutilation of gamergates resulted in a slight increase in both the frequency of dominance interactions and the ovarian activity of mutilated workers, but this effect was much lower than in colonies where the gamergate was removed. This contrasts with the immediate change in the behaviour (aggressive to timid) of newly emerged workers following mutilation.
Neocortex Size Predicts Group Size in Carnivores and Some Insectivores
Authors: Dunbar R. I. M. , Bever Julian
Published: May 2010

Neocortex size has been shown to correlate with group size in primates. Data for carnivores and insectivores are used to test the generality of this relationship. The data suggest that carnivores lie on the same grade as the primates, but that insectivores lie on a separate grade to the left of these two orders. Among the insectivores, there appears to be a distinction between the ‘advanced’ genera (which show a relationship between group size and neocortex size) and the ‘basal’ genera (which do not).
The Light and Magnetic Compass of the Weaver Ant, Oecophylla smaragdina (Hymenoptera: Formicidae)
Authors: Jander Rudolf , Jander Ursula
Published: May 2010

Some of the foraging of the arboreal Australian weaver ant Oecophylla smaragdina takes place on the ground. Odor trails and compass orientation are used to return to the trunk of their nesting tree. Field experiments established directional responses to light and the natural magnetic field. The precision of the light compass orientation is much greater than that of the magnetic compass orientation: the respective average wrapped‐around standard deviations (WSD) of directional choices towards home are WSD = ± 48° and WSD = ± 105°.
Parental Fin Digging by Cichlasoma octofasciatum (Teleostei: Cichlidae) and the Effect of Parents' Satiation State on Brood Provisioning
Authors: Zworykin Dmitry D.
Published: May 2010

Although parental care in fishes does not usually include provisioning offspring after hatching, various types of brood provisioning have been documented for some bony fishes, and in particular, for cichlids. For example, fin digging occurs among biparental substrate brooding cichlids of the ‘genus’ Cichlasoma sensu lato. Parental fin digging by Cichlasoma octofasciatum was investigated under laboratory conditions. Fin digging was performed significantly more often by females than by males. For both sexes, the frequency of fin digging increased significantly with brood age, especially from ages 3 to 10 d of fry: this was more pronounced in females. The parents' own current satiation state during performance of fin digging influenced the fin digging frequency: for both sexes it was higher in hungry than in satiated parents.
STOP Fracture study: Southern Health Osteoporotic Fracture Screening Project
Authors: Teede H. J. , Renouf D. A. , Jayasuriya I. A. , Barrie D.
Published: May 2010

Background:  Osteoporosis is a major healthcare issue with over 50% of postmenopausal women suffering an osteoporosis‐related fracture. Vertebral fractures, the commonest, are often asymptomatic, unrecognised and untreated.

Aims:  In a high risk population we aimed to screen for vertebral fractures with a lateral chest X‐ray then to intervene to highlight risk and improve fracture prevention.

Methods:  In this prospective interventional study, 104 postmenopausal women, presenting to hospital for unrelated conditions, were recruited. A baseline lateral chest X‐ray and fracture risk questionnaire was completed with a follow‐up questionnaire at 12 months. Where fractures were detected the study team intervened through correspondence, including evidence‐based guidelines recommending investigations and management to patients and general practitioners.

Results:  Ninety‐six women had a lateral chest X‐ray with 53 (55%) having vertebral fractures. Sixty‐five women completed baseline questionnaires and 64/65 had a calculated 5‐year fracture risk greater than 10%. At 12 months, 21% were commenced or continued on bisphosphonates with 17% adhering to therapy while eight had sustained a subsequent symptomatic fracture and eight women had died.

Conclusions:  Fifty‐five per cent of women over 65 years, presenting to hospital with unrelated medical conditions, had a previous minimal trauma vertebral fracture on lateral chest X‐ray. Potentially, a lateral chest X‐ray may provide a simple effective screening tool for osteoporotic fracture in this high‐risk population. Despite notification and recommendations to both patients and general practitioners, treatment uptake was poor, highlighting the need for further research into risk perception and behaviour change in both practitioners and patients.
Prevalence of Helicobacter pylori positivity in patients undergoing percutaneous coronary intervention
Authors: Hiew C. , Duggan A. , de Malmanche T. , Hatton R. , Baker F. , Attia J. , Collins N.
Published: May 2010

Background The adverse effect of haemorrhagic complications after percutaneous coronary intervention (PCI) on outcome is well established with Helicobacter pylori infection known to be an important precipitant of peptic ulcer disease in patients receiving non‐steroidal anti‐inflammatory drug therapy. The prevalence of H. pylori positivity in patients undergoing PCI and receiving subsequent antiplatelet therapy is unknown.

Aims: We sought to determine the prevalence and features associated with H. pylori positivity in patients undergoing PCI.

Methods: All patients undergoing PCI between August 2008 and April 2009 were identified and assessed for H. pylori positivity with serological status determined by using a commercially supplied enzyme‐linked immunosorbent assay.

Results: A total of 245 patients undergoing PCI during the study period had samples obtained for H. pylori serology. Of these, 91 were positive for H. pylori serology (37%) and 148 were negative (60%) with six samples being equivocal (3%). Of those patients positive for H. pylori, 75% were on agents at admission known to promote or precipitate gastrointestinal haemorrhage. Patients positive for H. pylori tended to be older, with increased creatinine and more likely to be receiving proton pump inhibitor therapy.

Conclusions: In an unselected cohort of patients undergoing PCI in a single centre, we detected a prevalence of H. pylori positivity in 37% of patients; this denotes a potentially treatable precipitant of haemorrhage in a considerable portion of patients receiving dual antiplatelet therapy after PCI. Further prospective study is required to determine if the presence of H. pylori positivity is associated with adverse events in terms of gastrointestinal and cardiac outcomes.
Negative soil feedbacks accumulate over time for non‐native plant species
Authors: Diez Jeffrey M. , Dickie Ian , Edwards Grant , Hulme Philip E. , Sullivan Jon J. , Duncan Richard P.
Published: May 2010

Ecology Letters (2010) 13: 803–809

The enemy release hypothesis is a common explanation for species invasions, suggesting that introduced species benefit from leaving behind natural enemies in the native range. However, any such advantage may attenuate over time. In this study, we test a prediction of this more dynamic enemy release hypothesis: that non‐native plant species that became established longer ago exhibit stronger negative feedbacks with the soil. Consistent with declining enemy release over time, we found increasingly negative soil feedbacks for species established longer ago in New Zealand. Negative soil feedbacks were also stronger for more widespread species, but weaker for more locally abundant species, suggesting that species accumulate negative interactions as they spread and can be locally regulated by these interactions. We also present data to support the common assumption that relatives have similar impacts on and responses to soil communities. Together, these data highlight the dynamic nature of novel interactions arising from species introductions.
Local context drives infection of grasses by vector‐borne generalist viruses
Authors: Borer Elizabeth T. , Seabloom Eric W. , Mitchell Charles E. , Power Alison G.
Published: May 2010

Ecology Letters (2010) 13: 810–818

Host characteristics commonly determine infection risk, but infection can also be mediated by regional‐ or local‐scale variation in the biotic and abiotic environment. Experiments can clarify the relative importance of these factors. We quantified drivers of infection by barley and cereal yellow dwarf viruses (B/CYDV), a group of generalist, vector‐borne grass pathogens, at hierarchically nested spatial scales (105–1 m) by planting individuals of six common grass species into five Pacific Coast grassland sites spanning 7° of latitude (> 5000 total hosts) and applying a factorial combination of nitrogen and phosphorus fertilizer. Infection differed most among experimental blocks (102–103 m scale), suggesting that local factors control infection risk; infection increased with cover of long‐lived hosts and phosphorus, but not nitrogen, fertilization. For B/CYDV, local context more strongly predicts infection risk than host species traits or regional context; such spatially nested experiments can clarify the factors underlying variation in infection risk.
How do traits vary across ecological scales? A case for trait‐based ecology
Authors: Messier Julie , McGill Brian J. , Lechowicz Martin J.
Published: May 2010

Ecology Letters (2010) 13: 838–848

Despite the increasing importance of functional traits for the study of plant ecology, we do not know how variation in a given trait changes across ecological scales, which prevents us from assessing potential scale‐dependent aspects of trait variation. To address this deficiency, we partitioned the variance in two key functional traits (leaf mass area and leaf dry matter content) across six nested ecological scales (site, plot, species, tree, strata and leaf) in lowland tropical rainforests. In both traits, the plot level shows virtually no variance despite high species turnover among plots and the size of within‐species variation (leaf + strata + tree) is comparable with that of species level variation. The lack of variance at the plot level brings substantial support to the idea that trait‐based environmental filtering plays a central role in plant community assembly. These results and the finding that the amount of within‐species variation is comparable with interspecific variation support a shift of focus from species‐based to trait‐based ecology.
A global perspective on belowground carbon dynamics under nitrogen enrichment
Authors: Liu Lingli , Greaver Tara L.
Published: May 2010

Ecology Letters (2010) 13: 819–828

Nitrogen (N) effects on ecosystem carbon (C) budgets are critical to understand as C sequestration is considered as a mechanism to offset anthropogenic CO2 emissions. Interactions between aboveground C and N cycling are more clearly characterized than belowground processes. Through synthesizing data from multiple terrestrial ecosystems, we quantified the responses of belowground C cycling under N addition. We found that N addition increased litter input from aboveground (+20%) but not from fine root. N addition inhibited microbial activity as indicated by a reduction in microbial respiration (−8%) and microbial biomass carbon (−20%). Although soil respiration was not altered by N addition, dissolved organic carbon concentration was increased by 18%, suggesting C leaching loss may increase. N addition increased the C content of the organic layer (+17%) but not the mineral soil layer. Overall, our meta‐analysis indicates that N addition will increase short term belowground C storage by increasing C content of organic layer. However, it is difficult to predict the response of long term C sequestration since there is no significant change in mineral soil C content.
Introduced grazers can restrict potential soil carbon sequestration through impacts on plant community composition
Authors: Bagchi Sumanta , Ritchie Mark E.
Published: May 2010

Ecology Letters(2010) 13: 959–968

Grazing occurs over a third of the earth’s land surface and may potentially influence the storage of 109Mg year−1of greenhouse gases as soil C. Displacement of native herbivores by high densities of livestock has often led to overgrazing and soil C loss. However, it remains unknown whether matching livestock densities to those of native herbivores can yield equivalent soil C sequestration. In the Trans‐Himalayas we found that, despite comparable grazing intensities, watersheds converted to pastoralism had 49% lower soil C than watersheds which retain native herbivores. Experimental grazer‐exclusion within each watershed type, show that this difference appears to be driven by indirect effects of livestock diet selection, leading to vegetation shifts that lower plant production and reduce likely soil C inputs from vegetation byc.25 gC m−2 year−1. Our results suggest that while accounting for direct impacts (stocking density) is a major step, managing indirect impacts on vegetation composition are equally important in influencing soil C sequestration in grazing ecosystems.
Early intervention with phosphodiesterase‐5 inhibitors after prostate brachytherapy improves subsequent erectile function
Authors: Pahlajani Geetu , Raina Rupesh , Jones J. Stephen , Burdick Michael , Ali Marwan , Li Jianbo , Mahadevan Arul , Ciezki Jay , Zippe Craig
Published: May 2010

Study Type – Therapy (case series) Level of Evidence 4

OBJECTIVE

To examine the early use of phosphodiesterase‐5 inhibitor (PDE‐5i; sildenafil citrate) in preventing subsequent erectile dysfunction (ED) after (monotherapy) prostate brachytherapy (PB, an accepted option for Gleason 6 or low‐volume Gleason 7 prostate cancer), as PB is currently being offered more frequently in younger patients, and ED can be a side‐effect often within the first 12 months after treatment.

PATIENTS AND METHODS

We examined a single‐surgeon series of 69 patients who had been treated with PB from 2002 to 2005. All patients had a follow‐up of ≥1 year; prospectively, and patients had baseline, 6‐ and 12‐month assessments using the Sexual Health Inventory for Men (SHIM) and International Index of Erectile Function (IIEF)‐6 scores. The 69 patients were divided into early treatment with PDE‐5i (31) and not treated with PDE‐5i (38), and their SHIM and IIEF‐6 scores were compared at baseline, 6 and 12 months. Daily sildenafil (25–50 mg) was given immediately after PB for 12 months. Overall, for the entire group, the mean prostate‐specific antigen (PSA) level was 6.8 ng/mL; 78% had Gleason 6 cancer and 20% had Gleason 7 (3 + 4) cancer. The mean age in the early PDE‐5i group was 64.8 years, and was 66.0 years in the no‐PDE‐5i group. The mean radiation dose in the early PDE‐5i group was 50.2 Gy, and 43.9 Gy in the other group (P= 0.08).

RESULTS

In the no‐PDE‐5i group, the mean baseline SHIM score of 17.1 decreased rapidly to 9.1 at 6 months (P= 0.01) and stayed at 9.3 at 12 months (P= 0.01). In the early PDE‐5i group, the mean baseline SHIM score of 21.8 decreased slightly to 17.6 at 6 months (P= 0.2), and was maintained at 17.9 at 12 months (P= 0.2). Using the Wilcoxon rank‐sum test, the 6‐ and 12‐month SHIM scores in the two groups (P < 0.001). The IIEF‐6 questionnaire confirmed the SHIM analysis.

CONCLUSIONS

After PB patients had a significant decline in SHIM/IIEF‐6 scores at 6 and 12 months. Our results indicate a 50% decrease in the quality of their erections. This provides an opportunity to initiate early intervention with PDE‐5i or perhaps vacuum constriction devices or intraurethral alprostadil. In this study, the early use of PDE‐5i after PB maintained erectile function at both 6 and 12 months.
Bipolar transurethral resection in saline vs traditional monopolar resection of the prostate: results of a randomized trial with a 2‐year follow‐up
Authors: Chen Qi , Zhang Li , Fan Qi‐Liang , Zhou Juan , Peng Yu‐Bing , Wang Zhong
Published: May 2010

Study Type – Therapy (RCT) Level of Evidence 1b

OBJECTIVE

To present 2‐year follow‐up data of a randomized clinical trial comparing bipolar transurethral resection in saline (TURIS) with monopolar transurethral resection of the prostate (TURP).

PATIENTS AND METHODS

In all, 100 consecutive patients with benign prostatic hyperplasia (BPH) were randomized to TURIS or TURP. The breath ethanol test was used before and every 10 min during surgery to assess fluid absorption. Complications and treatment efficacy were evaluated after surgery.

RESULTS

The operative duration and resected tissue weight were similar between the groups. The mean decreases in serum sodium and haemoglobin after surgery were significantly less in the TURIS group. The mean (standard deviation) irrigant absorbed was significantly less in TURIS than in the TURP group, at 208 (344)mL vs 512 (706) mL respectively (P < 0.001). In both the TURIS and TURP groups there were significant improvements in International Prostate Symptoms Scores and maximum urinary flow rates. The acute and late complications in the groups were statistically similar.

CONCLUSION

Bipolar TURIS seems to be a safe and effective procedure, which is associated with significantly less fluid absorption and similar efficacy as traditional monopolar TURP.
Vocational Education and Training and Human Capital Development: current practice and future options
Authors: WALLENBORN MANFRED
Published: May 2010

EU neighbouring countries (partner countries) have made considerable efforts to improve their vocational education and training (VET) systems, with different policies and strategies that take account of country‐specific priorities in human capital development. This article addresses the donor community. It analyses the role of partner countries' VET in contributing to human capital development in order to benefit better from the globalised economy. The emerging debate on the role of VET in these countries and among donors is considered in terms of the functional dimensions of employability, productivity and sustainable growth, taking into account the economic, social and ecological dimension of growth and development. Not addressed is the systemic perspective on VET in terms of improving existing curricula, learning arrangements and textbooks. The article focuses, rather, on functional dimensions of VET that are relevant to achieve development goals and makes some recommendations for international cooperation. Given the complexity of multi‐stakeholder‐driven VET systems, cooperation needs to build on existing VET structures. Moreover, cooperation must contribute to an effective reform implementation.
Vocational Education for Sustainable Development: an obligation for the European Training Foundation
Authors: VIERTEL EVELYN
Published: May 2010

This article presents an argued case for making sustainable development a policy obligation for the European Training Foundation (ETF) and for vocational education and training (VET) reform in the partner countries that are served by ETF. In relation to ETF it points out that no major emphasis has been put to date on combining economic, social and environmental considerations. It then analyses the ways economies operate in relation to sustainable development and the changed knowledge and skills needed for both economies and for a sustainable future. Implications for VET reform include attending to the broad goals of inclusion and equity, a reconsideration of the competences to be developed and the didactic approaches within a framework of lifelong learning. The didactics proposed are in line with current thinking related to constructivist pedagogy, an inter‐disciplinary approach to ‘real life’ problems and increasing the porosity of school boundaries to the community. The scope of VET's mission should extend well beyond the confines of preparing young people for narrow labour market skills.

The article is of particular significance for re‐directing the focus of ETF and VET reform policy but will be of interest to a much wider audience, as it provides a synthesis of future‐oriented ideas and options relating to education's obligations to face the urgent need to ensure sustainability.
Subitizing and counting in typical and atypical development
Authors: Schleifer Patrick , Landerl Karin
Published: May 2010

Enumeration performance in standard dot counting paradigms was investigated for different age groups with typical and atypically poor development of arithmetic skills. Experiment 1 showed a high correspondence between response times and saccadic frequencies for four age groups with typical development. Age differences were more marked for the counting than the subitizing range. In Experiment 2 we found a discontinuity between subitizing and counting for dyscalculic children; however, their subitizing slopes were steeper than those of typically developing control groups, indicating a dysfunctional subitizing mechanism. Across both experiments a number of factors could be identified that affect enumeration in the subitizing and the counting range differentially. These differential patterns further support the assumption of two qualitatively different enumeration processes.
Does Centralization Affect the Number and Size of Lobbies?
Authors: REDOANO MICHELA
Published: May 2010

Previous research has shown that the effect of fiscal centralization is to reduce lobbying. However empirical evidence suggests that this is not always the case. This paper attempts to explain the empirical evidence in a two‐jurisdiction political economy model of endogenous lobby formation and policy determination. We measure lobbying in two ways: (i) the number of lobbies formed under the two settings and (ii) their impact on policy decisions. We show that, contrary to the predictions of the preference dilution effect, the effect of centralization on lobbying are ambiguous with respect to both measures of lobbies.
Asymmetric Information and Annuities
Authors: PLATONI SILVIA
Published: May 2010

The standard Rothschild and Stiglitz (1976) and Wilson (1977) analysis of adverse selection economies is extended to a particular model of annuity market which features both elements of moral hazard and adverse selection. Individuals are heterogeneous with respect to time preferences and they make investments in health care that affect their survival probabilities. The main case considered is that where both preferences and investments (and hence the endogenous survival probabilities) are unobserved. Thus, the model captures a further source of inefficiency that is particular to annuity market: an endogenous correlation between the desire for annuities and the survival probabilities. The basic insights of Wilson (1977)—as worked out by Eckstein, Eichenbaum and Peled (1985)—are worth also in this new setting. When the equilibrium is separating, the government intervention may yield Pareto improvements. If the equilibrium is pooling, the government intervention may improve the well‐being of individuals affected by the inefficiencies and the negative externalities caused by the asymmetric information.