142 research outputs found
Resurrection of the sea pen genus Ptilella Gray, 1870 and description of Ptilella grayi n. sp. from the NE Atlantic (Octocorallia: Pennatulacea)
The order Pennatulacea covers a group of specialized and morphologically distinct octocorals found in all oceans from intertidal areas to more than 6000 m in depth. Sea pens constitute an important structural component in marine soft-bottom communities by increasing the complexity of these environments. Despite being both morphologically distinctive and ecologically important, the taxonomy and systematics of sea pens is still poorly understood. Recent molecular studies have shown the existence of convergent morphological features, making the current familial distribution of genera unstable. The genus Pennatula Linnaeus, 1758 was one of the first described octocoral genera. It is the type genus of its family, Pennatulidae. Colonies of this genus have a characteristic morphology. Recent sampling efforts in the northeastern Atlantic have provided a number of colonies initially attributable to the genus Pennatula. Both morphological and molecular (mtMutS, Cox1 and 28S genes) study of this material supports the polyphyletic nature of this genus and the need to resurrect the genus Ptilella Gray, 1870 to accommodate these and other species. A new species, Ptilella grayi n. sp., is described and illustrated. The species Pennatula bayeri is proposed to be a junior synonym of Pennatula bellissima (here also considered in the genus Ptilella)
Genome skimming elucidates the evolutionary history of Octopoda
Phylogenies for Octopoda have, until now, been based on morphological characters or a few genes. Here we provide the complete mitogenomes and the nuclear 18S and 28S ribosomal genes of twenty Octopoda specimens, comprising 18 species of Cirrata and Incirrata, representing 13 genera and all five putative families of Cirrata (Cirroctopodidae, Cirroteuthidae, Grimpoteuthidae, Opisthoteuthidae and Stauroteuthidae) and six families of Incirrata (Amphitretidae, Argonautidae, Bathypolypodidae, Eledonidae, Enteroctopodidae, and Megaleledonidae) which were assembled using genome skimming. Phylogenetic trees were built using Maximum Likelihood and Bayesian Inference with several alignment matrices. All mitochondrial genomes had the ‘typical’ genome composition and gene order previously reported for octopodiforms, except Bathypolypus ergasticus, which appears to lack ND5, two tRNA genes that flank ND5 and two other tRNA genes. Argonautoidea was revealed as sister to Octopodidae by the mitochondrial protein-coding gene dataset, however, it was recovered as sister to all other incirrate octopods with strong support in an analysis using nuclear rRNA genes. Within Cirrata, our study supports two existing classifications suggesting neither is likely in conflict with the true evolutionary history of the suborder. Genome skimming is useful in the analysis of phylogenetic relationships within Octopoda; inclusion of both mitochondrial and nuclear data may be key
The effect of review writing on learning engagement in channel partner relationship management
To develop the knowledge and skill sets of channel partner firms, firms increasingly introduce learning programs as part of their relationship management strategies. Yet, the engagement of channel partners in these programs tends to be low though. The current research, conducted in collaboration with a Fortune 100 information technology company, examines ways to strengthen learning engagement. In accordance with self-regulated learning theory, the authors propose and demonstrate that when channel partners write reviews of a learning module that they attended, beyond providing ratings,they are better able to reflect on the relevance of their learning experience and they are further engaged in learning activities. The audience and focus of these written reviews determine the engagement of the channel partner sales personnel. Therefore, review writing is a valuable, informal mechanism to motivate them. These effects are moderated by characteristics of both the channel partner (learning orientation of the salesperson, identification with the manufacturer) and the relationship with the manufacturer (length and exclusivity)
Implementation of a Referral Pathway and Peri-operative Checklist for Delivery of Surgical Tracheostomy Provision during the COVID-19 Pandemic
Genome skimming elucidates the evolutionary history of Octopoda
11 pages, 5 figures, 3 tables, supplementary data https://doi.org/10.1016/j.ympev.2023.107729Phylogenies for Octopoda have, until now, been based on morphological characters or a few genes. Here we provide the complete mitogenomes and the nuclear 18S and 28S ribosomal genes of twenty Octopoda specimens, comprising 18 species of Cirrata and Incirrata, representing 13 genera and all five putative families of Cirrata (Cirroctopodidae, Cirroteuthidae, Grimpoteuthidae, Opisthoteuthidae and Stauroteuthidae) and six families of Incirrata (Amphitretidae, Argonautidae, Bathypolypodidae, Eledonidae, Enteroctopodidae, and Megaleledonidae) which were assembled using genome skimming. Phylogenetic trees were built using Maximum Likelihood and Bayesian Inference with several alignment matrices. All mitochondrial genomes had the ‘typical’ genome composition and gene order previously reported for octopodiforms, except Bathypolypus ergasticus, which appears to lack ND5, two tRNA genes that flank ND5 and two other tRNA genes. Argonautoidea was revealed as sister to Octopodidae by the mitochondrial protein-coding gene dataset, however, it was recovered as sister to all other incirrate octopods with strong support in an analysis using nuclear rRNA genes. Within Cirrata, our study supports two existing classifications suggesting neither is likely in conflict with the true evolutionary history of the suborder. Genome skimming is useful in the analysis of phylogenetic relationships within Octopoda; inclusion of both mitochondrial and nuclear data may be keyThis work was funded by a Tony Ryan Fellowship and an Irish Research Council postgraduate scholarship (GOIPG/2017/1740) to MT. FÁF-Á was supported by an Irish Research Council–Government of Ireland Postdoctoral Fellowship Award (ref. GOIPD/2019/460) and a JdC-I Postdoctoral Fellowship Grant (ref. IJC2020-043170-I) awarded by MCIN/AEI /10.13039/501100011033 and the European Union NextGenerationEU/PRTR. This research was supported by the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S). We are grateful to two anonymous referees for their thoughtful contributionsPeer reviewe
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Improved charge collection of the buried p-i-n a-Si:H radiation detectors
Charge collection in hydrogenated amorphous silicon (a-Si:H) radiation detectors is improved for high LET particle detection by adding thin intrinsic layers to the usual p-i-n structure. This buried p-i-n structure enables us to apply higher bias and the electric field is enhanced. When irradiated by 5.8 MeV {alpha} particles, the 5.7 {mu}m thick buried p-i-n detector with bias 300V gives a signal size of 60,000 electrons, compared to about 20,000 electrons with the simple p-i-n detectors. The improved charge collection in the new structure is discussed. The capability of tailoring the field profile by doping a-Si:H opens a way to some interesting device structures. 17 refs., 7 figs
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Measurements of 1/f noise in A-Si:H pin diodes and thin-film-transistors
We measured the equivalent noise charge of a-Si:H pin diodes (5 {approximately} 45{mu}m i-layer) with a pulse shaping time of 2.5 {mu}sec under reverse biases up to 30 V/{mu}m and analyzed it as a four component noise source. The frequency spectra of 1/f noise on the soft-breakdown region and of the Nyquist noise from contact resistance of diodes were measured. Using the conversion equations for a CR-RC shaper, we identified the contact resistance noise and the 1/f noise as the main noise sources in the low bias and high bias regions respectively. The 1/f noise of a-Si:H TFTs with channel length of 15 {mu}m was measured to be the dominant component up to {approximately}100kHz for both saturation and linear regions. 15 refs., 7 figs
The prospectivity of a potential shale gas play: An example from the southern Pennine Basin (central England, UK)
During the Serpukhovian (late Mississippian) Stage, the Pennine Basin, now underlying much of northern England, consisted of a series of interlinked sub-basins that developed in response to the crustal extension north of the Hercynic orogenic zone. For the current study, mudstone samples of the Morridge Formation from two sub-basins located in the south-eastern part of the Pennine Basin were collected from the Carsington Dam Reconstruction C3 Borehole (Widmerpool Gulf sub-basin) and the Karenight 1 Borehole (Edale Gulf sub-basin). Detailed palynological analyses indicate that aside from the dominant (often 90% or more) heterogeneous amorphous organic matter (AOM), variable abundances of homogeneous AOM and phytoclasts are present. To complement the palynological dataset, a suite of geochemical and mineralogical techniques were applied to evaluate the prospectivity of these potentially important source rocks. Changes in the carbon isotope composition of the bulk organic fraction (δ13COM) suggest that the lower part (Biozone E2a) of Carsington DR C3 is markedly more influenced by terrigenous kerogen than the upper part of the core (Biozones E2a3–E2b1). The Karenight 1 core yielded more marine kerogen in the lower part (Marine Bands E1–E2b) than the upper part (Marine Band E2b). Present day Rock-Eval™ Total Organic Carbon (TOC) surpasses 2% in most samples from both cores, a proportion suggested by Jarvie (2012) that defines prospective shale gas reservoirs. However, when the pyrolysable component that reflects the generative kerogen fraction is considered, very few samples reach this threshold. The kerogen typing permits for the first time the calculation of an original hydrogen index (HIo) and original total organic carbon (TOCo) for Carboniferous mudstones of the Pennine Basin. The most prospective part of Carsington DR C3 (marine bands E2b1–E2a3) has an average TOCo of 3.2% and an average HIo of 465 mg/g TOCo. The most prospective part of Karenight 1 (242.80–251.89 m) is characterized by an average TOCo of 9.3% and an average HIo of 504 mg/g TOCo. Lastly, X-ray diffraction (XRD) analysis confirms that the siliceous to argillaceous mudstones contain a highly variable carbonate content. The palynological, geochemical and mineralogical proxies combined indicate that marine sediments were continuously being deposited throughout the sampled intervals and were punctuated by episodic turbiditic events. The terrestrial material, originating from the Wales-Brabant High to the south of the Pennine Basin, was principally deposited in the Widmerpool Gulf, with much less terrigenous organic matter reaching the Edale Gulf. As a consequence, the prospective intervals are relatively thin, decimetre-to meter-scale, and further high resolution characterization of these intervals is required to understand variability in prospectivitiy over these limited intervals
Sr-Nd isotope stratification along water depth: An example from Datong hydrological station of Yangtze River
School Surveillance, Control, and Resistance in the United Kingdom
This chapter outlines the development of the current socio-political context within which U.K. schools experience surveillance and implement their security and disciplinary procedures. Schools are suggested to have developed their approaches to social control against a background of neoliberalism and audit culture. This involves the marketisation of much of the school system through an ‘academisation’ process; linked to this is an increased surveillance of teachers and students through datafication, CCTV and other digital means. Another form of surveillance- biopolitical control in schools- shows itself through the traditionalisation of gendered school uniform and the increasing pathologisation of the behaviour of ethnic minorities
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