The objective of this work is to categorize the available fly ashes in different parts of the world into distinct groups based on its compositional attributes. Kohonen's self-organizing feature map and radial basis function networks are applied in a cascading fashion for the classification of fly ashes in terms of its chemical parameters. The basic procedure of the methodology consists of three stages: apply self-organizing neural net to ascertain possible number of groups, delineate them and identify the group sensitive attributes; (...) find mean values of sensitive attributes of the elicited groups and augment them as start-up prototypes in k-means algorithm and find the refined centroids of these groups; incorporate the centroids in a two layer radial basis function network and fine-tune the delineated groups and develop an indexing equation using the weights of the stabilized network. Further, to demonstrate the utility of this classification scheme, the so formed groups were correlated with their performance in High Volume Fly Ash Concrete System [HVFAC]. The categorization was found to be excellent and compares well with Canadian Standard Association's [CSA A 3000] classification scheme. (shrink)

Plamondon & Alimi's model will gain substantially in credibility when it is able to come up with predictions for new (rather than old) experimental results that discriminate between various models. Moreover, the present model is nothing more than a descriptive not an explanation for motor performance. A link to the contribution of various neuronal mechanisms involved in motor control and of muscle properties to the performance of the model is crucial.

Recent results have shown that the relative activation of muscles is different for isometric contractions and for movements. These results exclude an explanation of muscle activation patterns by a combination ofreciprocal and coactivation commands. These results also indicate that joint stiffness is not uniquely determined and that it may be different for isometric contractions and movements.

Background. The COVID-19 pandemic necessitated drastic changes to undergraduate medical training at the University of Botswana (UB). To save the academic year when campus was locked down, the Department of Medical Education conducted a needs assessment to determine the readiness for emergency remote teaching (ERT) of the Faculty of Medicine, UB. Objectives. To report on the findings of needs assessment surveys to assess learner and teaching staff preparedness for fair and just ERT, as defined by philosopher John Rawls. Methods. Needs (...) assessment surveys were conducted using Office 365 Forms distributed via WhatsApp, targeting medical students and teaching staff during the 5 undergraduate years. Data were analysed quantitatively and qualitatively. Results. Ninety-two percent (266/289) of students and 73.5% (62/84) of teaching staff responded. Surveys revealed a high penetration of smartphones among students, but poor internet accessibility and affordability in homes. Some teaching staff also reported internet and device insufficiencies. Only WhatsApp was accessible to students and teaching staff. Conclusions. For equitable access to ERT in the future, the surveys revealed infrastructural improvement needs, including wider, stronger, affordable WiFi coverage within Botswana and enhanced digital infrastructures in educational institutions, with increased support for students. (shrink)

In our society, where interest in Buddhist meditation is expanding enormously, numerous scientific studies are now conducted on the neurophysiological effects of meditation practices and on the neural correlates of meditative states. However, very few studies have been conducted on the experience associated with contemplative practice: what it is like to meditate -- from moment to moment, at different stages of practice -- remains almost invisible in contemporary contemplative science. Recently, 'micro-phenomenological' interview methods have been developed to help us become (...) aware of lived experience and describe it with rigour and precision. The present article presents the results of a pilot project1 aimed at applying these methods to the description of meditative experience. The first part of the article describes these methods and their adjustment for the investigation of meditative experience. The second part provides micro- phenomenological descriptions of two processes of which meditation practice enables the practitioner to become aware: the process of losing contact with the current situation and generation of virtual ones in 'mind-wandering' episodes, and the process of emergence of a thought. The third part of the article highlights the interest such descriptions may have for practitioners and for teachers of meditation, defines the status of these results, and outlines directions for further research. (shrink)

The larval arms of echinoid plutei are used for locomotion and feeding. They are composed of internal calcite skeletal rods covered by an ectoderm layer bearing a ciliary band. Skeletogenesis includes an autonomous molecular differentiation program in primary mesenchyme cells (PMCs), initiated when PMCs leave the vegetal plate for the blastocoel, and a patterning of the differentiated skeletal units that requires molecular cues from the overlaying ectoderm. The arms represent a larval feature that arose in the echinoid lineage during the (...) Paleozoic and offers a subject for the study of gene co-option in the evolution of novel larval features. We isolated new molecular markers in two closely related but differently developing species, Heliocidaris tuberculata and Heliocidaris erythrogramma. We report the expression of a larval arm-associated ectoderm gene tetraspanin, as well as two new PMC markers, advillin and carbonic anhydrase. Tetraspanin localizes to the animal half of blastula stage H. tuberculata and then undergoes a restriction into the putative oral ectoderm and future location of the postoral arms, where it continues to be expressed at the leading edge of both the postoral and anterolateral arms. In H. erythrogramma, its expression initiates in the animal half of blastulae and expands over the entire ectoderm from gastrulation onward. Advillin and carbonic anhydrase are upregulated in the PMCs postgastrulation and localized to the leading edge of the growing larval arms of H. tuberculata but do not exhibit coordinated expression in H. erythrogramma larvae. The tight spatiotemporal regulation of these genes in H. tuberculata along with other ontogenetic and phylogenetic evidence suggest that pluteus arms are novel larval organs, distinguishable from the processes of skeletogenesis per se. The dissociation of expression control in H. erythrogramma suggest that coordinate gene expression in H. tuberculata evolved as part of the evolution of pluteus arms, and is not required for larval or adult development. (shrink)

The star-nosed mole is aptly named. Its distinctive snout consists of 22 tendrils ringing a pair of nostrils and, from some angles, the entire setup resembles a misshapen star. The tendrils are fleshy and look a bit like fingers, and, like fingers, they have a certain dexterity. But why? Why does the mole have such a singular appendage as opposed to something more ordinary? What is the function or purpose of this bizarre structure? From the dedicated work of Ken Catania, (...) of Vanderbilt University, and colleagues, it appears that the appendage facilitates rapid handling of small prey items, making it advantageous for an organism whose diet consists of tiny invertebrates. We might therefore hazard that this feature arose evolutionarily because it conferred this benefit. But the matter is difficult to resolve, because current utility does not permit a straightforward inference of a reason for existence. -/- A correction has been published: BioScience, Volume 72, Issue 7, July 2022, Page 708. (shrink)

The use of platelet rich plasma as a novel treatment is discussed in the context of a qualitative research study comprising 38 interviews with sports medicine practitioners and other stakeholders working within the English Premier League during the 2013–16 seasons. Analysis of the data produced several overarching themes: conservatism versus experimentalism in medical attitudes; therapy perspectives divergence; conflicting versions of appropriate evidence; subcultures; community beliefs/practices; and negotiation of medical decision-making. The contested evidence base for the efficacy of PRP is presented (...) in the context of a broader professional shift towards evidence based medicine within sports medicine. Many of the participants while accepting this shift are still committed to casuistic practices where clinical judgment is flexible and does not recognize a context-free hierarchy of evidentiary standards to ethically justifiable practice. We also discuss a tendency in the data collected to consider the use of deceptive, placebo-like, practices among the clinician participants that challenge dominant understandings of informed consent in medical ethics. We conclude that the complex relation between evidence and ethics requires greater critical scrutiny for this emerging specialism within the medical community. (shrink)