1,721,151 research outputs found
Swearing at work and permissive leadership culture
No full textPurpose: the purpose of this paper is to examine the use of expletives and swearing in the workplace. It proposes to challenge leadership style and to suggest ideas for management best practice.Design/methodology/approach: case studies and qualitative analysis were applied, methods that fit well for this sensitive topic.Findings: this paper identifies the relevance, and even the importance, of using non‐conventional and sometimes uncivil language in the workplace.Research limitations/implications: sample size and representativeness present limitations.Practical implications: there is a need for leaders to apply, under certain circumstances, a permissive leadership culture. This paper advises leaders on how it may lead to positive consequences.Originality/value: the paper is an original contribution to an area where research is scarce. A certain originality element stems from the fact that, focusing on swearing language, the paper found it necessary to use swear words (avoiding usage of the explicit form); bearing in mind the purpose of the paper, the paper hopes that this will not cause offence to the readership of the journal
The invasive gastropod Crepidula fornicata: reproduction and recruitment in the intertidal at its northernmost range in Wales, UK, and implications for its secondary spread
No full textThe establishment and spread of a non-native species in an introduced range depends to a large extent on the performance of the species under the prevailing environmental conditions. The spawning, larval and spatfall periods of the invasive gastropod Crepidula fornicata were monitored in the intertidal zone at its northernmost range in Wales, UK, between February 2010 and January 2011. The duration of the reproductive season was similar to that recorded from more southerly European populations. Spawning and larval release occurred throughout most of the year even at low seawater temperatures of <7 °C, but benthic recruitment was observed over a much shorter period at seawater temperatures >16 °C. Recruitment was low and likely controlled by post-settlement mortality. These observations suggest that C. fornicata’s northwards spread in Welsh waters will not be limited by seawater temperature negatively affecting reproduction, but by processes acting after larval release. These data show the importance of incorporating settlement and post-settlement processes into studies on recruitment success when aiming to predict the potential spread of a potentially harmful invader such as C. fornicata
The influence of mussel-modified habitat on Fucus serratus L. a rocky intertidal canopy-forming macroalga
Full text linkThe influence of habitat modification by Mytilus edulis L. on the settlement and development of Fucus serratus populations was investigated on rocky shores of the Isle of Anglesey, North Wales. Settlement of fucoids was higher inside mussel habitat than outside on one of two shores studied. The effect of microhabitat on survival of fucoid germlings was examined by transplanting the germlings into and outside mussel habitats, each with and without the exclusion of grazers. Observation showed that periwinkles and top shells were abundant in mussel habitat, while limpets dominated bare rock. Exclusion of grazers greatly enhanced the survival of fucoid germlings in both habitats, indicating that while mussel habitat supports a different grazer assemblage to bare rock, both assemblages are important in limiting fucoid recruitment. The risk of dislodgement was assessed and compared between fucoids growing on mussel shells and bare rock. In situ pull-tests showed that less force was required to detach large fertile thalli growing on mussel shells than those growing on the rock. Adhesion was generally broken between the mussel and the rock rather than between the holdfast and the mussel. These observations indicate that mussels provide an unstable substrate for mature fucoids. Overall results suggest that a negative effect of mussel-modified habitat on fucoids is profound in adults; but the effect is context-dependent in juveniles and can be positive at settlement. Results from a survey on population structure of fucoids across two shores showed that there were greater numbers of large fertile fucoids growing directly attached to rock than on mussel shells, while there was no difference for juvenile fucoids confirming the experimental results. Moreover thalli larger than 60 cm were found only on the rock but not on shells. This finding suggests that a mussel dominated habitat may have a significant impact on reproductive output in fucoid populations
Cannibalistic interactions in two co-occurring decapod species: Effects of density, food, alternative prey and habitat
No full textCannibalism is a potentially important factor in the regulation of populations in a range of habitats. The intensity of this biotic factor may be determined by both intra and interspecific interactions. Cancer pagurus and Porcellana platycheles are two co-occurring decapods on Atlantic rocky shores. In laboratory mesocosms, we investigated intra and intersize class cannibalistic and interspecific predatory behaviours in those species. We addressed the effects of prey and predator densities, food, starvation, alternative prey and habitat type. No agonistic behaviour was noted in P. platycheles, suggesting a non-aggressive co-existence between gregarious individuals. Predation of C. pagurus on P. platycheles was intense, possibly accounting for the spatial segregation observed in the natural environment. Cannibalism among C. pagurus juveniles was low and only on vulnerable prey (i.e. at moulting), suggesting a non-aggressive co-existence among juveniles. However, intersize class cannibalism in C. pagurus was intense (ontogenetic shift), possibly reflecting the juvenile-adult segregation in the natural environment. Prey and predator densities, food and habitat type strongly influenced this behaviour. Possible interference among cannibals was noted, with lower prey consumption at high predator density. Food supply alone had more effect on cannibalistic rate than did alternative prey (P. platycheles) and predator starvation. Structurally complex habitats (small pebble and Fucus serratus habitats) yielded higher prey survival than the sandy habitat, and the behaviours of both prey and cannibals reflected the small-scale spatial distribution of individuals in the wild. Intersize class cannibalism and interspecific agonistic relationships may account for the intertidal distribution of crab species at low tide
Larval microhabitat associations of the non-native gastropod Crepidula fornicata and effects on recruitment success in the intertidal zone
No full textHabitat-specific distributions of marine benthic invertebrates can be caused by several processes acting prior to, during or after settlement, including differential settlement and varying levels ofmortality between habitat types following adaptation of the benthicmode. The non-native gastropod Crepidula fornicata is known for its gregarious settlement patterns, yet associations with other shellfish species are also common. In the present study, a series of no-choice and choice laboratory assays were undertaken in which larvae were offered different settlement substrata, separately and simultaneously, to investigate whether differential settlement of C. fornicata larvae occurs in favour of specific microhabitat types. A field experiment was also conducted to test if recruitment success in the intertidal differed between microhabitat types, by comparing densitiesof young (b2 weeks) andolder (b8 weeks) settlers. The laboratory studies indicated that settlement occurs in larger numbers in association with certain habitats. However, settlement in association with specific microhabitat types was not observed in the intertidal. Instead, the distribution of C. fornicata recruits is established after settlement, as the distribution of older recruits, but not younger ones, differed between microhabitat types. Our findings show that the availability of certain complex structures in the intertidal zone is highly important in determining survival success of C. fornicata, due to varying levels of post-settlement mortality
The importance of larval supply, larval habitat selection and post-settlement mortality in determining intertidal adult abundance of the invasive gastropod Crepidula fornicata
No full textUnderstanding the processes that drive the recruitment of invasive non-native species is of critical importance in evaluating their potential to colonise previously unoccupied habitats. The slipper limpet Crepidula fornicata has spread rapidly into most European waters since its first introduction from the North West Atlantic in the late 19th century. Its invasion success is thought to have been aided by its long larval phase and its tolerance towards a wide range of environmental conditions. The Milford Haven Waterway in Wales, U.K. supports a population with highly variable densities in the intertidal as well as the subtidal zone. In the present study, we tested a series of existing models to investigate the roles of larval supply, larval habitat selection and post-settlement mortality in determining the final distribution of C. fornicata in the intertidal zone of the Milford Haven Waterway. During the main reproductive season of 2011, data on total settlement rates and recruitment were collected by deploying slate panels for varying durations in the low intertidal zone, and data on larval abundances were obtained by taking frequent plankton samples at two sites with contrasting adult densities: Beggars Reach (~ 15 ± 13 ind m? 2) and Pennar (~ 343 ± 360 ind m? 2). Total larval densities were much higher at Pennar, but densities of late-stage larvae (i.e. larval supply) were similar at both sites, indicating that local hydrodynamics may have resulted in the spatial homogenisation of supply of late-stage, metamorphically competent larvae, despite the higher larval production at the high adult abundance site. Settlement rates also did not differ between sites. Seasonal recruitment was overall low, indicating that post-settlement mortality, likely as a consequence of exposure to intertidal conditions, is very high. The lack of a relationship between adult abundance and settlement rates indicates that the final distribution of C. fornicata in the intertidal may be a result of differential post-settlement mortality. Understanding recruitment patterns in non-native species is essential for developing management strategies for potentially harmful invaders such as C. fornicata
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Settlement and post-settlement interactions between Semibalanus balanoides (L.) (Crustacea: Cirripedia) and three species of fucoid canopy algae
No full textManipulative field experiments carried out on sheltered rocky shores investigated settlement and post-settlement interactions between Semibalanus balanoides and three species of fucoid canopy algae, Fucus spiralis L., Ascophyllum nodosum (L.) Le Jolis and Fucus serratus L. All three species had a negative effect on settlement and early recruitment of S. balanoides, densities being significantly lower on settlement tiles beneath the canopy compared to cleared areas. Investigation of the mechanism by which settlement and recruitment were inhibited showed the importance of sweeping of algal fronds at all three shore heights. In addition, we found that the F. serratus canopy inhibited settlement not only by its sweeping action but also by limiting the access of cyprids to the substratum. Detailed examination of the sweeping effect in F. serratus showed that newly settled cyprids transplanted beneath a canopy suffered extremely high mortality (between 82 and 97%) over just one high water period. Mortality was significantly reduced for individuals that had settled within a matrix of adults. Metamorphosis of cyprids to spat conferred no additional resistance to sweeping-induced mortality but resistance increased in 6 day old spat. Mortality in S. balanoides after the end of the settlement season was monitored for three months in experimental treatments and controls. Mortality rates were significantly lower under the canopy than in cleared areas in both the F. spiralis and Ascophyllum zones. The overall influence of each canopy species on the development of barnacle populations on sheltered shores is discussed
Interaction between a fucoid canopy and limpet grazing in structuring a low shore intertidal community
No full textThe relative roles of a macroalgal canopy, Fucus serratus L., and a grazer, Patella vulgata L., in structuring a low shore community of a sheltered, rocky intertidal site were examined using a factorial experimental design. Canopy removal and grazer exclusion treatments were used to determine the effects of both factors on the understorey community. Re-establishment of the canopy was studied in relation to grazing pressure and substrate type in order to determine how this macroalga maintains its spatial and temporal dominance on the low shore. In addition, the size of canopy clearances were varied to determine the effect of gap size on community structure. Removal of the F. serratus canopy alone resulted in little change to the understorey community. Few understorey species were adversely affected by exposure to increased light levels and the grazing pressure of limpets was sufficient to prevent large scale recruitment of algae. Removal of limpets alone resulted in little change except for a greatly enhanced recruitment of F. serratus juveniles, indicating that grazing pressure rather than the canopy was inhibiting recruitment of the canopy species. Large changes in community structure only occurred following removal of both the canopy and grazers together since either the canopy or limpet grazing alone was sufficient to prevent large scale recruitment of algae. Limpet grazing did not prevent the re-establishment of a F. serratus canopy, although recovery was delayed in comparison to plots where limpets were removed. The size of gaps in the canopy had no discernible effect on the species composition or rate of succession in experimental treatments
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