An Analysis of Stable Isotopes from n-alkanes derived from Leaf Waxes in North America

Leaf wax biomarkers are increasingly becoming a fundamental aspect of paleoclimate research. The strength of the relationship between their molecular and isotopic properties and environmental conditions is critical to their effectiveness in reconstructing past environments. To address the current lack of data pertaining to arid and semi-arid environments, soil and modern plant samples (grasses, trees, forbs, and shrubs) from sites in the western United States were analyzed to assess relationships between normal alkane molecular distribution, δD and δ13C and seasonal/annual climatic conditions in semi-arid ecosystems. The data show a stronger relationship between δD of leaf waxes (δDwax) in soils and δD of mean annual precipitation (δDMAP) than the δD of plants. δDwax of grasses and soils correlate with latitude, mean annual vapor pressure deficit (VPD), mean annual temperature (MAT), and annual relative humidity (RH). No relationships were observed between δ13Cwax or the molecular distribution of the waxes and any of the climate variables tested. There is an offset between the δD and δ13C of these waxes and the δD and δ13C of the environment in which they were created. The apparent fractionation (εwax/atm) between δDwax and δDMAP for grasses and soils correlated with latitude as well as mean annual RH. There was no relationship found for the carbon discrimination between δ13Cwax and δ13Catm (Δleafwax/atm) and the climatic variables tested. To further investigate the dominant environmental drivers controlling the composition of leaf wax biomarkers, data from the Western United States was then combined with published data from studies throughout the United States. These combined data show distinct distributions of εwax/atm from soils in different climates. The εwax/atm of the plants display correlations to mean annual VPD. The data also show an increase in the Average Chain Length (ACL) of the n-alkanes in soils with increased temperature and aridity. In contrast to previous studies, the offset between carbon isotope composition of bulk leaf tissue and leaf wax biomarkers varied in the soils. This suggests that the fractionation between the carbon isotope composition of bulk leaf tissue and leaf wax could be due to the differences in environmental or vegetation type. The data presented here suggest careful consideration of ecosystem type is critical to reconstructing past environmental conditions using leaf wax biomarkers

Promoting knowledge creation discourse in an Asian primary five classroom: Results from an inquiry into life cycles

The phrase 'knowledge creation' refers to the practices by which a community advances its collective knowledge. Experience with a model of knowledge creation could help students to learn about the nature of science. This research examined how much progress a teacher and 16 Primary Five (Grade 4) students in the International Baccalaureate Primary Years Programme could make towards the discourse needed for Bereiter and Scardamalia's model of knowledge creation. The study consisted of two phases: a five-month period focusing on the development of the classroom ethos and skills needed for this model (Phase 1), followed by a two-month inquiry into life cycles (Phase 2). In Phase 1, we examined the classroom practices that are thought to support knowledge creation and the early experiences of the students with a web-based inquiry environment, Knowledge Forum®. In Phase 2, we conducted a summative evaluation of the students' work in Knowledge Forum in the light of the model. The data sources included classroom video recordings, artefacts of the in-class work, the Knowledge Forum database, a science content test, questionnaires, and interviews. The findings indicate that the students made substantial progress towards the knowledge creation discourse, particularly regarding the social structure of this kind of discourse and, to a lesser extent, its idea-centred nature. They also made acceptable advances in scientific knowledge and appeared to enjoy this way of learning. The study provides one of the first accounts in the literature of how a teacher new to the knowledge creation model enacted it in an Asian primary classroom. © 2011 Taylor & Francis.postprin

Efficient Bayesian-based Multi-View Deconvolution

Light sheet fluorescence microscopy is able to image large specimen with high resolution by imaging the sam- ples from multiple angles. Multi-view deconvolution can significantly improve the resolution and contrast of the images, but its application has been limited due to the large size of the datasets. Here we present a Bayesian- based derivation of multi-view deconvolution that drastically improves the convergence time and provide a fast implementation utilizing graphics hardware.Comment: 48 pages, 20 figures, 1 table, under review at Nature Method

On the use of simulation as a Big Data semantic validator for supply chain management

Simulation stands out as an appropriate method for the Supply Chain Management (SCM) field. Nevertheless, to produce accurate simulations of Supply Chains (SCs), several business processes must be considered. Thus, when using real data in these simulation models, Big Data concepts and technologies become necessary, as the involved data sources generate data at increasing volume, velocity and variety, in what is known as a Big Data context. While developing such solution, several data issues were found, with simulation proving to be more efficient than traditional data profiling techniques in identifying them. Thus, this paper proposes the use of simulation as a semantic validator of the data, proposed a classification for such issues and quantified their impact in the volume of data used in the final achieved solution. This paper concluded that, while SC simulations using Big Data concepts and technologies are within the grasp of organizations, their data models still require considerable improvements, in order to produce perfect mimics of their SCs. In fact, it was also found that simulation can help in identifying and bypassing some of these issues.This work has been supported by FCT (Fundacao para a Ciencia e Tecnologia) within the Project Scope: UID/CEC/00319/2019 and by the Doctoral scholarship PDE/BDE/114566/2016 funded by FCT, the Portuguese Ministry of Science, Technology and Higher Education, through national funds, and co-financed by the European Social Fund (ESF) through the Operational Programme for Human Capital (POCH)

The Role of Zinc in the Modulation of Neuronal Proliferation and Apoptosis

Although a requirement of zinc (Zn) for normal brain development is well documented, the extent to which Zn can modulate neuronal proliferation and apoptosis is not clear. Thus, we investigated the role of Zn in the regulation of these two critical events. A low Zn availability leads to decreased cell viability in human neuroblastoma IMR-32 cells and primary cultures of rat cortical neurons. This occurs in part as a consequence of decreased cell proliferation and increased apoptotic cell death. In IMR-32 cells, Zn deficiency led to the inhibition of cell proliferation through the arrest of the cell cycle at the G0/G1 phase. Zn deficiency induced apoptosis in both proliferating and quiescent neuronal cells via the intrinsic apoptotic pathway. Reductions in cellular Zn triggered a translocation of the pro-apoptotic protein Bad to the mitochondria, cytochrome c release, and caspase-3 activation. Apoptosis is the resultant of the inhibition of the prosurvival extracellular-signal-regulated kinase, the inhibition of nuclear factor-kappa B, and associated decreased expression of antiapoptotic proteins, and to a direct activation of caspase-3. A deficit of Zn during critical developmental periods can have persistent effects on brain function secondary to a deregulation of neuronal proliferation and apoptosis

An Interprofessional, Tailored Behavioral Intervention for Sleep Problems in Autism: Use of Sensory Data to Inform Intervention

Purpose: The purpose of this poster is to demonstrate how Sensory Profile data informed occupational therapy sleep interventions for two participants as part of an Interprofessional Tailored Behavioral Intervention study

Novel Characterization of Lymphatic Valve Formation during Corneal Inflammation

Lymphatic research has progressed rapidly in recent years. Though lymphatic dysfunction has been found in a wide array of disorders from transplant rejection to cancer metastasis, to date, there is still little effective treatment for lymphatic diseases. The cornea offers an optimal site for lymphatic research due to its accessible location, transparent nature, and lymphatic-free but inducible features. However, it still remains unknown whether lymphatic valves exist in newly formed lymphatic vessels in the cornea, and how this relates to an inflammatory response. In this study, we provide the first evidence showing that lymphatic valves were formed in mouse cornea during suture-induced inflammation with the up-regulation of integrin alpha 9. The number of corneal valves increased with the progression of inflammatory lymphangiogenesis. Moreover, we have detected lymphatic valves at various developmental stages, from incomplete to more developed ones. In addition to defining the average diameter of lymphatic vessels equipped with lymphatic valves, we also report that lymphatic valves were more often located near the branching points. Taken together, these novel findings not only provide new insights into corneal lymphatic formation and maturation, but also identify a new model for future investigation on lymphatic valve formation and possibly therapeutic intervention

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Impact of COVID-19 on Formal Education: An International Review of Practices and Potentials of Open Education at a Distance

In terms of scale, shock, and disenfranchisement, the disruption to formal education arising from COVID-19 has been unprecedented. Anecdotally, responses from teachers and educators around the world range from heightened caution to being inspired by distance education as the “new normal.” Of all the challenges, face-to-face and formal teaching have been most heavily affected. Despite some education systems demonstrating resilience, a major challenge is sustaining quality and inclusiveness in formal education suddenly delivered at a distance. In probing these issues, this article profiles international perspectives on the role of open education in responding to the impact on formal school and higher education caused by the COVID-19 pandemic. We proceed by highlighting and analysing practices and case studies from 13 countries representing all global regions, identifying and discussing the challenges and opportunities that have presented themselves. Reports cover the period from the beginning of 2020 until 11 March 2021, the first anniversary of the COVID-19 outbreak as declared by the World Health Organization. In our comparative study, we identify seven key aspects of which three (missing infrastructure and sharing OER, open education and access to OER, and urgent need for professional development and training for teachers) are directly related to open education at a distance. After comparing examples of existing practice, we make recommendations and offer insights into how open education strategies can lead to interventions that are effective and innovative—to improve formal education at a distance in schools and universities in the future

Antimicrobial resistance (AMR) nanomachines: mechanisms for fluoroquinolone and glycopeptide recognition, efflux and/or deactivation

In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics—the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins. Expression of efflux systems is regulated by GntR-like (S. aureus NorG), MarR-like (MgrA, MepR) regulators or a two-component signal transduction system (TCS) (S. aureus ArlSR). Resistance to the glycopeptide antibiotic teicoplanin occurs via efflux regulated by the TcaR regulator in S. aureus. Resistance to vancomycin occurs through modification of the D-Ala-D-Ala target in the cell wall peptidoglycan and removal of high affinity precursors, or by target protection via cell wall thickening. Of the six Van resistance types (VanA-E, VanG), the VanA resistance type is considered in this review, including its regulation by the VanSR TCS. We describe the recent application of biophysical approaches such as the hydrodynamic technique of analytical ultracentrifugation and circular dichroism spectroscopy to identify the possible molecular effector of the VanS receptor that activates expression of the Van resistance genes; both approaches demonstrated that vancomycin interacts with VanS, suggesting that vancomycin itself (or vancomycin with an accessory factor) may be an effector of vancomycin resistance. With 16 and 19 proteins or protein complexes involved in fluoroquinolone and glycopeptide resistances, respectively, and the complexities of bacterial sensing mechanisms that trigger and regulate a wide variety of possible resistance mechanisms, we propose that these antimicrobial resistance mechanisms might be considered complex ‘nanomachines’ that drive survival of bacterial cells in antibiotic environments