Supporting 3rd-grade students’ model-based explanations about groundwater: A quasi-experimental study of a curricular intervention

Scientific modelling is a key practice in which K-12 students should engage to begin developing robust conceptual understanding of natural systems, including water. However, little past research has explored primary students’ learning about groundwater, engagement in scientific modelling, and/or the ways in which teachers conceptualize and cultivate model-based science learning environments. We are engaged in a multi-year project designed to support 3rd-grade students’ formulation of model-based explanations (MBE) for hydrologic phenomenon, including groundwater, through curricular and instructional support. In this quasi-experimental comparative study of five 3rd-grade classrooms, we present findings from analysis of students’ MBE generated as part of experiencing a baseline curricular intervention (Year 1) and a modelling-enhanced curricular intervention (Year 2). Findings show that students experiencing the latter version of the unit made significant gains in both conceptual understanding and reasoning about groundwater, but that these gains varied by classroom. Overall, student gains from Year 1 to Year 2 were attributed to changes in two of the five classrooms in which students were provided additional instructional supports and scaffolds to enhance their MBE for groundwater. Within these two classrooms, the teachers enacted the Year 2 curriculum in unique ways that reflected their deeper understanding about the practices of modelling. Their enactments played a critical role in supporting students’ MBE about groundwater. Study findings contribute to research on scientific modelling in elementary science learning environments and have important implications for teachers and curriculum developers

Interactome and evolutionary conservation of Dictyostelid small GTPases and their direct regulators

The GTP binding proteins known as small GTPases make up one of the largest groups of regulatory proteins and control almost all functions of living cells. Their activity is under respectively positive and negative regulation by guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), which together with their upstream regulators and the downstream targets of the small GTPases form formidable signaling networks. While genomics has revealed the large size of the GTPase, GEF and GAP repertoire, only a small fraction of their interactions and functions have yet been experimentally explored. Dictyostelid social amoebas have been particularly useful in unraveling the roles of many proteins in the Rac-Rho and Ras-Rap families of GTPases in directional cell migration and regulation of the actin cytoskeleton. Almost completely assembled genomes and cell-type specific and developmental transcriptomes are available for Dictyostelium species that span the 0.5 billion years of evolution of the group from their unicellular ancestor. In this work, we identified all GTPases, GEFs and GAP from genomes representative of the four major taxon groups and investigated their phylogenetic relationships and evolutionary conservation and change in their functional domain architecture and in their developmental and cell-type specific expression. We performed hierarchical cluster analysis of the expression profiles of the ~2000 analysed genes to identify putative interacting sets of GTPases, GEFs and GAPs, which highlighted sets known to interact experimentally and many novel combinations. The work represents a valuable resource for research into all fields of cellular regulation

The SLUGGS Survey: Globular cluster system kinematics and substructure in NGC 4365

We present a kinematic analysis of the globular cluster (GC) system of the giant elliptical galaxy NGC 4365 and find several distinct kinematic substructures. This analysis is carried out using radial velocities for 269 GCs, obtained with the DEIMOS instrument on the Keck II telescope as part of the SAGES Legacy Unifying Globulars and Galaxies Survey (SLUGGS). We find that each of the three (formerly identified) GC colour subpopulations reveal distinct rotation properties. The rotation of the green GC subpopulation is consistent with the bulk of NGC 4365's stellar light, which `rolls' about the photometric major axis. The blue and red GC subpopulations show `normal' rotation about the minor axis. We also find that the red GC subpopulation is rotationally dominated beyond 2.5 arcmin (~17 kpc) and that the root mean squared velocity of the green subpopulation declines sharply with radius suggesting a possible bias towards radial orbits relative to the other GC subpopulations. Additionally, we find a population of low velocity GCs that form a linear structure running from the SW to the NE across NGC 4365 which aligns with the recently reported stellar stream towards NGC 4342. These low velocity GCs have g'-i' colours consistent with the overall NGC 4365 GC system but have velocities consistent with the systemic velocity of NGC 4342. We discuss the possible formation scenarios for the three GC subpopulations as well as the possible origin of the low velocity GC population.Comment: 15 pages, 12 figures, accepted for publication in MNRAS. For more information on "The SLUGGS Survey" see: http://sluggs.swin.edu.au

The protein kinases of Dictyostelia and their incorporation into a signalome

© 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)Protein kinases are major regulators of cellular processes, but the roles of most kinases remain unresolved. Dictyostelid social amoebas have been useful in identifying functions for 30% of its kinases in cell migration, cytokinesis, vesicle trafficking, gene regulation and other processes but their upstream regulators and downstream effectors are mostly unknown. Comparative genomics can assist to distinguish between genes involved in deeply conserved core processes and those involved in species-specific innovations, while co-expression of genes as evident from comparative transcriptomics can provide cues to the protein complement of regulatory networks. Genomes and developmental and cell-type specific transcriptomes are available for species that span the 0.5 billion years of evolution of Dictyostelia from their unicellular ancestors. In this work we analysed conservation and change in the abundance, functional domain architecture and developmental regulation of protein kinases across the 4 major taxon groups of Dictyostelia. All data are summarized in annotated phylogenetic trees of the kinase subtypes and accompanied by functional information of all kinases that were experimentally studied. We detected 393 different protein kinase domains across the five studied genomes, of which 212 were fully conserved. Conservation was highest (71%) in the previously defined AGC, CAMK, CK1, CMCG, STE and TKL groups and lowest (26%) in the “other” group of typical protein kinases. This was mostly due to species-specific single gene amplification of “other” kinases. Apart from the AFK and α-kinases, the atypical protein kinases, such as the PIKK and histidine kinases were also almost fully conserved. The phylogeny-wide developmental and cell-type specific expression profiles of the protein kinase genes were combined with profiles from the same transcriptomic experiments for the families of G-protein coupled receptors, small GTPases and their GEFs and GAPs, the transcription factors and for all genes that upon lesion generate a developmental defect. This dataset was subjected to hierarchical clustering to identify clusters of co-expressed genes that potentially act together in a signalling network. The work provides a valuable resource that allows researchers to identify protein kinases and other regulatory proteins that are likely to act as intermediates in a network of interest.This work was funded by grant 100293/Z/12/Z from the Wellcome Trust, grant 742288 from the European Research Council and grant BB/K000799/1 from the BBSRC. K.K. was also supported by EMBO Long-term fellowship ALTF 295–2015 and by JSPS Overseas Research Fellowship H28–1002.Peer reviewe

Effects of chicory / ryegrass swards compared with ryegrass swards on the performance and carcass quality of grazing beef steers

An experiment investigated whether the inclusion of chicory (Cichorium intybus) in swards grazed by beef steers altered their performance, carcass characteristics or parasitism when compared to steers grazing perennial ryegrass (Lolium perenne). Triplicate 2-ha plots were established with a chicory/ryegrass mix or ryegrass control. Forty-eight Belgian Blue-cross steers were used in the first grazing season and a core group (n = 36) were retained for finishing in the second grazing season. The experiment comprised of a standardisation and measurement period. During standardisation, steers grazed a ryegrass/white clover pasture as one group. Animals were allocated to treatment on the basis of liveweight, body condition and faecal egg counts (FEC) determined 7 days prior to the measurement period. The measurement period ran from 25 May until 28 September 2010 and 12 April until 11 October 2011in the first and second grazing year. Steers were weighed every 14 days at pasture or 28 days during housing. In the first grazing year, faecal samples were collected for FEC and parasite cultures. At the end of the first grazing year, individual blood samples were taken to determine O. ostertagi antibody and plasma pepsinogen levels. During winter, animals were housed as one group and fed silage. In the second grazing year, steers were slaughtered when deemed to reach fat class 3. Data on steer performance showed no differences in daily live-weight gain which averaged 1.04 kg/day. The conformation, fat grade and killing out proportion of beef steers grazing chicory/ryegrass or ryegrass were not found to differ. No differences in FEC, O. ostertagi antibody or plasma pepsinogen levels of beef steers grazing either chicory/ryegrass or ryegrass were observed. Overall, there were no detrimental effects of including chicory in swards grazed by beef cattle on their performance, carcass characteristics or helminth parasitism, when compared with steers grazing ryegrass

Wide-field imaging of NGC 4365's globular cluster system: The third subpopulation revisited

Analysis of the globular cluster (GC) system of the giant elliptical (E3) galaxy NGC 4365, from eight Hubble Space Telescope/Advanced Camera for Surveys (ACS) pointings and a wide-field Subaru/SuprimeCam (S-Cam) image, is presented. We determine the lower limit on the number of GCs to be 6450+-110 and show that the GC system extends beyond 134 kpc (9.5 galaxy effective radii). We revisit the question of whether NGC 4365 has a bimodal or trimodal GC colour distribution and find support for three distinct GC colour subpopulations (i.e. blue, green and red). Sersic profile fits to the radial surface density of each subpopulation reveal that the blue GCs are more extended than either red or green GCs. We find significant differences in the median half light radii for GCs in the blue, green and red subpopulations as well as in the subpopulation ellipticities. A KS test on the mass functions show >98 per cent probability that all three subpopulations are distinct from one another. We also find radial gradients of GC size and colour (metallicity) and a blue tilt. The properties, including surface density profile, position angle, ellipticity and radial colour gradient, of the red GC subpopulation are very similar to the properties of NGC 4365's starlight. This result supports the hypothesis that red GCs are formed along with the bulk of the diffuse starlight in the galaxy. NGC 4365 has a kinematically distinct core and a significant misalignment between the photometric and kinematic major axes. We discuss the possibility that these kinematic features are related to the presence of the distinct third GC subpopulation. We briefly discuss implications for the formation of NGC 4365. (Condensed from original.)Comment: 27 pages, 28 figures, accepted for publication in MNRA

Psychiatric comorbidities in epilepsy: population co-occurrence, genetic correlations and causal effects

Background: Psychiatric comorbidities are common in patients with epilepsy. Reasons for the co-occurrence of psychiatric conditions and epilepsy remain poorly understood. Aim: We aimed to triangulate the relationship between epilepsy and psychiatric conditions to determine the extent and possible origins of these conditions. Methods Using nationwide Swedish health registries, we quantified the lifetime prevalence of psychiatric disorders in patients with epilepsy. We then used summary data from genome-wide association studies to investigate whether the identified observational associations could be attributed to a shared underlying genetic aetiology using cross-trait linkage disequilibrium score regression. Finally, we assessed the potential bidirectional relationships using two-sample Mendelian randomisation. Results: In a cohort of 7 628 495 individuals, we found that almost half of the 94 435 individuals diagnosed with epilepsy were also diagnosed with a psychiatric condition in their lifetime (adjusted lifetime prevalence, 44.09%; 95% confidence interval (CI) 43.78% to 44.39%). We found evidence for a genetic correlation between epilepsy and some neurodevelopmental and psychiatric conditions. For example, we observed a genetic correlation between epilepsy and attention-deficit/hyperactivity disorder (rg =0.18, 95% CI 0.09 to 0.27, p<0.001)—a correlation that was more pronounced in focal epilepsy (rg =0.23, 95% CI 0.09 to 0.36, p<0.001). Findings from Mendelian randomisation using common genetic variants did not support bidirectional effects between epilepsy and neurodevelopmental or psychiatric conditions. Conclusions: Psychiatric comorbidities are common in patients with epilepsy. Genetic correlations may partially explain some comorbidities; however, there is little evidence of a bidirectional relationship between the genetic liability of epilepsy and psychiatric conditions. These findings highlight the need to understand the role of environmental factors or rare genetic variations in the origins of psychiatric comorbidities in epilepsy

Effect of anaerobic digestate fuel pellet production on Enterobacteriaceae and Salmonella persistence

Publication history: Accepted - 10 June 2022; Published online - 7 July 2022.Production of digestate pellets for fuel has been identified as a promising circular economy approach to provide renewable energy and additional income to farms, while at the same time presenting the potential to divert raw digestate from nutrient-saturated land and reduce the risk to water quality. Although previous research has investigated the feasibility of pellet production, there has been little focus on the bio-safety aspects of the system. Little is currently known about the persistence of bacteria present in the digestate and the potential impacts on human health for those handling this product. The aim of the present research was to determine the effect that each step in the pellet production process has on bacteria numbers: anaerobic digestion, mechanical separation, solid drying, and pelletisation. Enterobacteriaceae enumeration by colony count method was used to quantify bacteria, and the presence of Salmonella at each stage was determined. The Enterobacteriaceae count reduced with each stage, and the final pelletisation step reduced bacteria numbers to below detectable levels (<10 colony forming units/g). Salmonella was only detected in the starting slurry and absent from digestate onwards. Storage of the pellets under winter and simulated summer conditions showed no reactivation of Enterobacteriaceae over time. The pelletisation process produces a digestate product with Enterobacteriaceae counts below the maximum threshold (PAS110 specification) for transport off the source farm, but care must still be taken when handling digestate pellets as complete sterilisation has not been confirmed.This project was supported by The Bryden Centre. The Bryden Centre project is supported by the European Union's INTERREG VA Programme, managed by the Special EU Programmes Body (SEUPB). The work was also supported by Queen's University Belfast and the Agri-Food and Biosciences Institute in Northern Ireland

The Grizzly, September 26, 1995

Ursinus Improves in National Rankings • Racism in Everywhere • The Dawn of a New S.T.A.R. • Royersford Teachers Strike • Restaurant Night is Back! • Stories from Abroad • Help, I\u27m an E-mail Addict! • Political Parties, Presidents, and Colin Powell • Writing Off Old Men\u27s? • Way to go, Collegeville! • Letters to the Editor • Spirit of Life Ensemble to Perform • Tobin Display at Berman • Are Wismer\u27s Grades Slipping? • Hillel Trip a Success • Celebrating Hispanic Heritage • What\u27s Going on at Ursinus College? • U.S.G.A. Minutes • C.A.B. Minutes • Conserve, Conserve, Conserve! What You Can do to Save Energy and the Earth • Soccer Team Splits • Field Hockey Team Wins Fourth Straight • Runners Compete • Football Team Not Offensive in Loss • Volleyball Team Nets Third Winhttps://digitalcommons.ursinus.edu/grizzlynews/1363/thumbnail.jp