The Lake Malawi cichlid genus Labeotropheus has been a source of confusion among biologists and taxonomists. Although unique populations of both L. fuelleborni and L. trewavasae exist throughout the ...lake, these populations have not been elevated to species, despite taxonomists doing so for populations within other Lake Malawi cichlids. One reason for this oversight is the supposed consistent differences in morphology between Labeotropheus species; since, where they co-occur, L. fuelleborni is always deeper-bodied than L. trewavasae, it is thought that all deep-bodied populations of Labeotropheus are L. fuelleborni, and the slender ones are L. trewavasae. Using geometric morphometrics, we analyze 18 populations of Labeotropheus and show that body shape varies among populations, and does not always fall into a deep-body/slender-body dichotomy. These differences in body shape are not related to geographical distance among populations, but are possibly related to the type of habitat in which the populations are found. Further, head shape is extremely variable among populations, and we find two locations where there is convergence in head shape between sympatric L. fuelleborni and L. trewavasae. Our results suggest that the morphological criteria applied to the Labeotropheus are not accurate, and hamper the recognition of Labeotropheus biodiversity.
•Virtual Reality is as a viable training method for low-voltage electrical safety.•VR training demonstrates overall effectiveness in reaction, learning, and duration.•Trainees react positively, ...notably for engagement, intention to use, and enjoyment.•VR facilitates learning; trainees retain substantial knowledge after four weeks.•Most trainees consider the 29- to 44-minute training duration appropriate.
Introduction: The widespread use and inherent risks associated with low-voltage electrical equipment require all workers to understand its hazards and how to manage them. Despite being the most commonly used method for raising safety awareness, lecture-based training often proves ineffective. Virtual reality (VR) allows the user to be immersed in a virtual environment and actively participate in practical training while maintaining their safety, which can potentially result in engaging and effective training. This paper investigates the effectiveness of using immersive VR for low-voltage (LV) electrical safety training to understand the potential benefits of VR technology for industrial safety training applications. Method: A within-group experimental design was employed with 18 participants undertaking the LV VR training. The effectiveness of the training was evaluated by measuring participants’ reactions, learning, and training duration. Participants’ learning was measured before, immediately after, and four weeks after the training, whereas reaction and suitability of training duration were measured after the training. Results: Participants reported highly positive reactions to the LV VR training, particularly regarding their level of engagement, intention to use the system in the future, and enjoyment. Knowledge test scores significantly improved immediately after training with high effect sizes. Although scores decreased significantly four weeks after training, they remained significantly higher compared to before training. The training duration, ranging from 29 to 44 minutes was considered suitable for the training. Conclusions: LV VR training effectively elicited positive reactions from trainees and supporting trainees to acquire and retain safety information while maintaining appropriate training duration. Practical Implications: VR emerges as a viable alternative training method worth exploring for organizations seeking to improve their safety training programs. VR combines educational and entertainment values, facilitating enjoyable learning experiences.
In 2013, we released a position paper to launch a community effort to define a common set of building blocks for constructing graph algorithms in the language of linear algebra. This led to the ...GraphBLAS. We released a specification for the C programming language binding to the GraphBLAS in 2017. Since that release, multiple libraries that conform to the GraphBLAS C specification have been produced. In this position paper, we launch the next phase of this ongoing community effort: a project to assemble a set of high level graph algorithms built on top of the GraphBLAS. While many of these algorithms are well-known with high quality implementations available, they have not been assembled in one place and integrated with the GraphBLAS. We call this project the LAGraph graph algorithms project and with this position paper, we put out a call for collaborators to join us. While the initial goal is to just assemble these algorithms into a single framework, the long term goal is a library of production-worthy code, with the LAGraph library serving as an open source repository of verified graph algorithms that use the GraphBLAS.
The Lake Malawi cichlid genus Labeotropheus has been a source of confusion among biologists and taxonomists. Although unique populations of both L. fuelleborni and L. trewavasae exist throughout the ...lake, these populations have not been elevated to species, despite taxonomists doing so for populations within other Lake Malawi cichlids. One reason for this oversight is the supposed consistent differences in morphology between Labeotropheus species; since, where they co-occur, L. fuelleborni is always deeper-bodied than L. trewavasae, it is thought that all deep-bodied populations of Labeotropheus are L. fuelleborni, and the slender ones are L. trewavasae. Using geometric morphometrics, we analyze 18 populations of Labeotropheus and show that body shape varies among populations, and does not always fall into a deep-body/slender-body dichotomy. These differences in body shape are not related to geographical distance among populations, but are possibly related to the type of habitat in which the populations are found. Further, head shape is extremely variable among populations, and we find two locations where there is convergence in head shape between sympatric L. fuelleborni and L. trewavasae. Our results suggest that the morphological criteria applied to the Labeotropheus are not accurate, and hamper the recognition of Labeotropheus biodiversity. Keywords Labeotropheus * Morphology * Geometric morphometrics * Head shape * Habitat type * Species concepts * Species criteria * Lake Malawi Cichlid
Quantum chemical calculations have been performed to evaluate the adsorption of NO on cobalt in several extraframework environments within ferrierite zeolites. All possible arrangements of the two ...nearby framework aluminum atoms have been considered for the B and G ferrierite cobalt sites. The cobalt–nitrosyl orientation, i.e., bent versus linear, depends on the local zeolite environment. The enthalpies and free energies of adsorption are also functions of the local zeolite environment. NO adsorption is favored by about 50 kJ/mol on cobalt in the B site compared to the G site. This large difference is attributable to two factors: differences in NO-induced strain on the cobalt–zeolite environments as well as an intrinsic difference based on the coordinative unsaturation of cobalt. A simulation of the temperature-programmed desorption profile reveals three distinct cobalt environments for adsorbed NO, showing the dependence of a macroscopic property that is related to catalytic activity on the local zeolite environment near a metal cation. This observation suggests that the increase in the turnover of NO to N
2 per cobalt atom with increasing cobalt loading reported in the literature may be related to the same factors. A detailed analysis of the cobalt–nitrosyl bond was also performed.
The extraframework locations of many metal cations in pentasil zeolites, such as ferrierite, are not known, but new infrared bands in the 800–1000 cm
−1 region are experimentally observed upon ...exchange. To investigate the origin of these bands and to better understand cation siting, density functional theory calculations were performed on ferrierite cluster models for seven divalent metals: magnesium, manganese, iron, cobalt, nickel, copper, and zinc. The calculated properties, such as the metal–zeolite binding energy, follow a U-shaped trend with respect to the number of metal d electrons. The calculated infrared bands are consistent with the occupation of the B and G ferrierite sites by the metal cations. However, a definitive assignment of the published experimental infrared bands to particular extraframework sites was not possible. Despite this limitation, all seven metals were shown to perturb the ferrierite framework similarly. All of the cations coordinate to four framework oxygen atoms and the framework T–O bonds associated with these oxygen atoms are elongated by the metal. This elongation is shown to be proportional to the wavenumber of the infrared bands.
The catalytic activity of metal-exchanged zeolites for nitrogen oxide (NO x ) reduction in the literature, as measured by the turnover of individual metal atoms, is not constant but generally ...increases with metal loading. The occupation of specific zeolite environments by metal atoms is also a function of the metal loading, suggesting that the metal−zeolite coordination environment influences the observed catalytic activity. Here, first principles calculations were applied to examine the adsorption of several molecules relevant to de-NO x catalysis for two metal−zeolite environments. For a given adsorbate, the preference for cobalt in the ferrierite B environment over the G environment ranges from negligible to approximately 40 kJ/mol. Two primary characteristics were identified that account for the variable preferential adsorption. First, calculations revealed that cobalt in the B environment is more coordinatively unsaturated than cobalt in the G environment. The second characteristic arises from the adsorbate-induced strain on the local zeolite environments, which is generally larger for the G environment. Additional effects are discussed for molecules capable of forming secondary hydrogen bonds with the zeolite and/or highly polar molecules such as water.
GBTL-CUDA: Graph Algorithms and Primitives for GPUs Zhang, Peter; Zalewski, Marcin; Lumsdaine, Andrew ...
2016 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW),
05/2016
Conference Proceeding
GraphBLAS is an emerging paradigm for graph computation that makes it easy to program new graph algorithms in a highly abstract language of linear algebra. The promise of GraphBLAS is that an ...abstract graph program will execute in a wide variety of programming environments, ranging from embedded environments to distributed memory computers. In this paper we present our initial implementation of GraphBLAS primitives for graphics processing unit (GPU) systems called GraphBLAS Template Library (GBTL). Our implementation is an ongoing effort in the context of GraphBLAS standardization efforts by a diverse group of academics and representatives of the industry. Our implementation consists of a high-level C ++ frontend, and the GPU functionality is implemented with a combination of the CUSP library for sparse-matrix computation on GPU and the NVIDIA Thrust framework for abstract GPU programs. We give initial performance results of our implementations, and we discuss solutions to the problems we encountered when providing a low-level implementation for a high-level generic interface.
In the first of this two-paper series, a new model is presented that simulates the effects of a temperature perturbation on the rate of slow desorption as a function of mass remaining. The model ...assumes slow desorption is controlled by one-dimensional diffusion from a single or many hydrophobic micropores and that the micropores of a geosorbent are defined by a γ distribution of diffusion rate constants. Simulation results indicate that during slow desorption the relative increase in flux upon heating increases with decreasing micropore width. Simulation results also indicate that the relative increase in flux upon heating increases with desorption time when diffusion occurs from successively smaller width micropores with decreasing mass remaining. In paper 2, the model is tested and used to examine micropore geometry in natural and model solids by simulating results from temperature stepped desorption (TSD) experiments.
This paper presents an analysis of the symbolic conditions which govern health care provision in the Scottish prison system. The paper considers the wider context of Scottish prisons, where health ...care provision follows a similar structure both in juvenile and adult prisons. Our intention is to provoke a debate about the doxa (Bourdieu, 1977), which underlies decision making in respect of health care in prison, in a political environment where pragmatism, allied to the 'pathologisation' of social policies, health and criminal justice has been a hegemonic force.
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