Nectar and oleiferous trichomes as floral attractants in Bulbophyllum saltatorium Lindl. (Orchidaceae)

Although many Orchidaceae have deceit flowers that produce no reward, the most common reward, when present, is nectar. Bulbophyllum, however, is unusual in that the labellar secretions of most species investigated to date lack sugars, and, therefore, cannot be considered true nectar. The African species Bulbophyllum saltatorium is an exception in that it produces not only nectar but also possesses specialized, capitate oleiferous trichomes. The nectary of B. saltatorium is borne on the labellum and is represented by a deep, narrow, median longitudinal groove, having a small aperture, and flanked by trichomes. Isodiametric epidermal cells lining this groove secrete nectar which collects both in the groove and on the surface of the labellum. As well as a nectary, the labellum of B. saltatorium also bears three types of unicellular trichomes: the longest trichomes are borne distally and abaxially; the marginal ones form a rim around the entire labellum, and finally, massive, capitate trichomes occur proximally and adaxially. These are oleiferous, containing large quantities of oil which might function as precursors of volatile components of fragrance or provide a food-reward. To the best of our knowledge, this is the first time for such oleiferous trichomes to be described for Bulbophyllum. Therefore, apart from their color and markings, flowers of this species are able to attract pollinators in at least two, possibly three ways: food-reward in the form of nectar; fragrance; and possibly food-rewards in the form of food-hairs

Floral micromorphology of the Australian carnivorous bladderwort Utricularia dunlopii, a putative pseudocopulatory species

Flowers of sexually deceptive taxa generally possess a set of morphological and physiological characters that mimic their insect pollinators. These characters often include a specific insect-like floral configuration, together with scent glands osmophores) that produce fragrances which chemically resemble insect sex pheromones. Furthermore, these flowers tend not to produce pollinator food rewards. According to some authors, flowers of the Australian bladderwort Utricularia dunlopii (and species of the Utricularia capilliflora complex) resemble insects, and pollination perhaps occurs by pseudocopulation. The aims of this paper are to compare the structure and distribution of floral glandular trichomes in the Australian carnivorous plant U. dunlopii with those of closely related species assigned to the same section and to discuss their putative function. Floral tissues of U. dunlopii P. Taylor, Utricularia paulinae Lowrie, Utricularia dichotoma Labill. and Utricularia uniflora R.Br. (section Pleiochasia) were investigated using light microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. In U. dunlopii, two long, erect, filiform appendages arising from the upper lip of the corolla, together with three arising from the lower lip, bear numerous glandular trichomes that may function as osmophores. In other species, such as U. uniflora and U. paulinae, glandular papillae on the corolla palate may also function as osmophores. The floral anatomical and morphological organisation of U. dunlopii differs from that of the other investigated species, indicating that its insect pollinators are also likely to differ. Morphological and ultrastructural observations, while generally contributing to our understanding of the flower of U. dunlopii, do not refute the possibility that pollination here may occur by pseudocopulation. Further field-based investigations, however, are now necessary to test this hypothesis

Dynacov: recharging Electric Vehicles while in motion:A collaboration between Coventry University and Coventry City Council

Dynamic Wireless Power Transfer (DWPT) revolutionises Electric Vehicles EVs by enabling on-the-go recharging through electromagnetic induction between a primary coil beneath the road and a secondary coil in the vehicle. Addressing EV limitations like range and recharging time, DWPT could drive EV adoption, especially among high-mileage vehicles, crucial for carbon emission reduction. The Dynacov project, led by Coventry City Council and funded by Western Power Distribution, aimed to develop DWPT and create an ecosystem for secure, automated wireless charging based on ISO 15118 standards . Targeting buses, heavy goods transport, and strategic road networks, this initiative involves Coventry University and Cenex in Systems Modelling activities to assess deployment areas and electrical grid impacts. Kenilworth Road in Coventry was chosen for DWPT feasibility assessment due to its varied traffic conditions and feasibility for infrastructure installation. Surveys confirmed viability and grid capacity to handle peak power demands. The initial project, constrained by the grid’s capability at 150kW, aimed to simultaneously charge two vehicles. This technology could transform transportation and sustainability, but the next steps involve accurately estimating project costs for technology procurement, installation, grid connection, and project management. DWPT, showcased in Dynacov, holds the potential to reshape EV charging dynamics.

Inertial measurement units for clinical movement analysis: reliability and concurrent validity

The aim of this study was to investigate the reliability and concurrent validity of a commercially available inertial-sensor-based motion capture system, Xsens MVN BIOMECH, during clinically relevant functional activities. A clinician with no prior experience of motion capture technologies and an experienced clinical movement scientist each assessed 26 healthy participants within each of two sessions using a camera-based motion capture system and the MVN BIOMECH system. Participants performed overground walking, squatting, and jumping. Sessions were separated by 4 ± 3 days. Reliability was evaluated using intraclass correlation coefficient and standard error of measurement, and validity was evaluated using the coefficient of multiple correlation and the linear fit method. Day-to-day reliability was generally fair-to-excellent in all three planes for hip, knee, and ankle joint angles in all three tasks. Within-day (between-rater) reliability was fair-to-excellent in all three planes during walking and squatting, and poor-to-high during jumping. Validity was excellent in the sagittal plane for hip, knee, and ankle joint angles in all three tasks and acceptable in frontal and transverse planes in squat and jump activity across joints. Our results suggest that the MVN BIOMECH system can be used by a clinician to quantify lower-limb joint angles in clinically relevant movements

Floral ultrastructure of two Brazilian aquatic-epiphytic bladderworts : Utricularia cornigera Studnička and U. nelumbifolia Gardner (Lentibulariaceae)

Utricularia cornigera and Utricularia nelumbifolia are giant, aquatic-epiphytic species of carnivorous bladderwort from southeastern Brazil that grow in the central ‘urns’ of bromeliads. Both species have large, colourful flowers. The main aim of our study is to ascertain whether the prominent floral palate of U. cornigera and U. nelumbifolia functions as an unguentarius-i.e. an organ that bears osmophores. Floral tissues of both species were investigated using light microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. Floral palates of U. cornigera and U. nelumbifolia provide clear visual signals for pollinating insects. In both species, the palate possesses diverse micro-morphology, comprising unicellular, conical to villiform papillae and multicellular, uniseriate, glandular trichomes that frequently display terminal branching. The most characteristic ultrastructural feature of these papillae was the presence of relatively large, polymorphic plastids (chromoplasts) containing many plastoglobuli. Similar plastids are known to occur in the fragrance-producing (osmophores) and oil-producing (elaiophores) tissues of several orchid species. Thus, these palate papillae may play a key role in providing the olfactory stimulus for the attraction of insect pollinators. Nectariferous trichomes were observed in the floral spurs of both species, and in U. nelumbifolia, free nectar was also recorded. The location, micro-morphology, anatomy and ultrastructure of the floral palate of the two species investigated may thus indicate that the palate functions as an unguentarius. Furthermore, the flowers of these taxa, like those of U. reniformis, have features consistent with bee pollination

Distribution of slow and fast rotators in the Fornax cluster

We present integral field spectroscopy of 10 early-type galaxies in the nearby, low-mass, Fornax cluster, from which we derive spatially resolved stellar kinematics. Based on the morphologies of their stellar velocity maps we classify 2/10 galaxies as slow rotators, with the remaining eight galaxies fast rotators. Supplementing our integral field observations with morphological and kinematic data from the literature, we analyse the ‘kinematic’ type of all 30 galaxies in the Fornax cluster brighter than MK = −21.5 mag (M* ∼ 6 × 109 M⊙). Our sample's slow rotator fraction within one virial radius is 7+4−6 per cent. 13+8−6 per cent of the early-type galaxies are slow rotators, consistent with the observed fraction in other galaxy aggregates. The fraction of slow rotators in Fornax varies with cluster-centric radius, rising to 16+11−8 per cent of all kinematic types within the central 0.2 virial radii, from 0 per cent in the cluster outskirts. We find that, even in mass-matched samples of slow and fast rotators, slow rotators are found preferentially at higher projected environmental density than fast rotators. This demonstrates that dynamical friction alone cannot be responsible for the differing distributions of slow and fast rotators. For dynamical friction to play a significant role, slow rotators must reside in higher mass sub-haloes than fast rotators and/or form in the centres of groups before being accreted on to the cluster

Prospectus, October 8, 1986

https://spark.parkland.edu/prospectus_1986/1024/thumbnail.jp

Prospectus, October 15, 1986

https://spark.parkland.edu/prospectus_1986/1025/thumbnail.jp

Nectar-Secreting and Nectarless Epidendrum: Structure of the Inner Floral Spur

Epidendrum, the largest genus of Neotropical orchids, contains both nectar-secreting and nectarless species. Here, we compare the fine structure of the inner floral spur, termed the cuniculus, in nectariferous (E. difforme, E. nocturnum,E. porpax, E. rigidum, E. vesicatum) and seemingly nectarless (E. capricornu, E. ciliare, E. criniferum, E. pseudepidendrum, E. radicans, E. xanthoianthinum) species. This is the first time for such a detailed investigation of cuniculus structure to be undertaken for Epidendrum. Our aim was to characterize features indicative of secretory activity and to ascertain whether flowers presumed to be nectarless produce alternative pollinator food-rewards. The cuniculus is formed by fusion of the basal part of the labellum and column and extends alongside the ovary and transmitting tract. Our study indicates that all investigated species produce nectar or nectar-like secretion to varying degrees, and no alternative pollinator food-rewards were observed. Even though macroscopic investigation of presumed rewardless species failed to reveal the presence of secretion within the cuniculus, close observations of the cells lining the cuniculus by LM, SEM, and TEM revealed the presence of cuticular blisters and surface material. Moreover, the similarity of both the thick tangential cell walls (with the exception of E. vesicatum) and organelle complement of cuniculus epidermal cells in both copiously nectariferous species and those producing only small quantities of surface secretion confirmed the presence of secretory activity in species generally regarded to be rewardless. The secretory character was particularly obvious in the cells of the cuniculus of E. nocturnum, but also in E. ciliare, E. radicans and E. xanthoianthinum, since electron-dense cytoplasm and mitochondria, ER and secretory vesicles were abundant. Furthermore, cell wall protuberances occurred in E. nocturnum, which was indicative of intense transmembrane transport. This investigation highlights the need to examine more closely whether Epidendrum spp. considered to lack food-rewards based solely on macroscopic examination really are rewardless and deceptive

Prospectus, October 22, 1986

https://spark.parkland.edu/prospectus_1986/1026/thumbnail.jp