1,223 research outputs found
An authentic approach to facilitating transfer of teacher's pedagogical knowledge
The pedagogical knowledge learned by pre-service teachers often fails to transfer to teaching practice. Instead, new teachers revert to instructional strategies they observed as children. This chapter describes design research conducted over four years, where pre-service teachers were immersed in an authentic learning environment using multimedia to learn mathematics assessment strategies. The first study was conducted with pre-service teachers in the second year of their degree, and then the second study followed up with the same people in their second year as practising teachers. The first study revealed several constraints for the participants on professional practice, including limited time and the influence of the supervising teacher. Later, as practising teachers, they faced cultural and practical constraints within the school environment that prevented them from fully operationalising the pedagogical principles they learned as pre-service teachers
Seasonal, Diel, and Spawning Habitat of the Rare Muscadine Darter (\u3cem\u3ePercina\u3c/em\u3e sp.) in the Conasauga River, Georgia
Modeling Supermassive Primordial Stars with MESA
Supermassive stars forming at 15 - 20 are one of the leading
contenders for the origin of the first quasars, over 200 of which have now been
discovered at 6. These stars likely form in pristine, atomically cooled
haloes immersed in strong Lyman-Werner UV backgrounds or in highly supersonic
baryon streaming flows. Atomic cooling triggers catastrophic baryon collapse
capable of building up stars at rates of up to 1 M yr.
Here we examine the evolution of supermassive stars with a much larger and
finer grid of accretion rates than in previous studies with the \texttt{MESA}
stellar evolution code. We find that their final masses range from 3.5
10 M - 3.7 10 M at accretion rates of
0.001 M yr - 1 M yr, respectively. We also
find that supermassive star evolution diverges at accretion rates of 0.01
M yr - 0.02 M yr, above which they evolve as
cool red hypergiants along the Hayashi track and collapse via the general
relativistic instability during central hydrogen burning, and below which they
evolve as hot blue supergiants and collapse at the end of their nuclear burning
lifetimes after exiting the main sequence.Comment: 11 pages, 10 figures, accepted by MNRA
Ανάδειξη της αγροτικής παραγωγής στην αστική καθημερινότητα. _προβολή _ εμπόριο _ ενημέρωση στην Θήβα
An 'aggregate economic' value (H), which is a combination of genetic control and relative economic value of traits, for all traits in the breeding objective was developed to aid in multitrait selection of strawberry cultivars in the subtropical southeast Queensland program. A profitability index for 12 traits was calculated from the effect of unit changes in each trait on changes in production costs and profitability. The index was applied to the breeding values of 3008 genotypes to produce estimates of H. H was validated by its high correlation (R=0.77) with year of selection (1945-1998) for commercial cultivars. H values for 3008 genotypes ranged from -0.36 to +0.28, when the zero value was set to the value of the cultivar 'Festival', which is the main cultivar grown in southeast Queensland. Modelling indicated that the gross margins were highly linearly related (R0.98) to H values where the genotype occupied less than 50% of total area planted in the industry, but this relationship became quadratic when the genotype occupied higher percentages of the total area planted to strawberries, and variation in gross margin increased as H values increased. H is efficient in identifying economically superior genotypes, but, when deploying new genotypes with high H, impacts on farm gross margin due to high adoption rates should also be considered
Turbulent Cold Flows Gave Birth to the First Quasars
How quasars powered by supermassive black holes (SMBHs) formed less than a
billion years after the Big Bang is still one of the outstanding problems in
astrophysics 20 years after their discovery. Cosmological simulations
suggest that rare cold flows converging on primordial haloes in low-shear
environments could have created these quasars if they were 10 - 10
M at birth but could not resolve their formation.
Semianalytical studies of the progenitor halo of a primordial quasar found that
it favours the formation of such seeds but could not verify if one actually
appeared. Here we show that a halo at the rare convergence of strong, cold
accretion flows creates massive BH seeds without the need for UV backgrounds,
supersonic streaming motions, or even atomic cooling. Cold flows drive violent,
supersonic turbulence in the halo that prevents star formation until it reaches
a mass that triggers sudden, catastrophic baryon collapse that forms 31,000 and
40,000 M stars. This simple, robust process ensures that haloes
capable of forming quasars by z 6 produce massive seeds. The first quasars
were thus a natural consequence of structure formation in cold dark matter
cosmologies, not exotic, finely-tuned environments as previously
thought.Comment: Author's version of a Letter published in Nature on July 6th, 202
Exploring structural and electronic effects in three isomers of tris{bis(trifluoromethyl)phenyl}borane: Towards the combined electrochemical-frustrated Lewis pair activation of H2
Three structural isomers of tris{bis(trifluoromethyl)phenyl}borane have been studied as the acidic com- ponent of frustrated Lewis pairs. While the 3,5-substituted isomer is already known to heterolytically cleave H2 to generate a bridging-hydride; ortho-substituents in the 2,4- and 2,5-isomers quench such reactivity through electron donation into the vacant boron pz orbital and steric blocking of the boron centre; as shown by electrochemical, structural and computational studies. Electrochemical studies of the corresponding borohydrides identify that the two-electron oxidation of terminal-hydrides occurs at more positive potentials than observed for [HB(C6F5)3]−, while the bridging-hydride oxidizes at a higher poten- tial still, comparable to that of free H2
Studying physiology within a flipped classroom – The importance of on-campus activities for nursing students’ experiences of mastery
Aims and objectives
To explore the on‐campus activities of the flipped classroom and their role in nursing students’ experiences of mastering physiology.
Background
A nurse must be confident in their knowledge of physiology to feel confident as a nurse. However, many nursing students do not believe in their ability to master physiology. The flipped classroom design could facilitate active learning and promote students’ confidence and competence in physiology.
Design
A design‐based research design was employed.
Methods
Twenty‐three nursing students enrolled in an anatomy and physiology course participated in two focus group interviews and wrote two individual reflective notes. The data were analysed by means of systematic text condensation and activity theory. Reporting was guided by the Consolidated Criteria for Reporting Qualitative Studies (COREQ).
Results
The study findings underscore the importance of careful design of on‐campus activities within the flipped classroom to support students’ experiences of mastery in physiology. Four themes were identified: (a) preparation which builds a foundation for learning; (b) the use of digital tools; (c) learning through dialogue with peers; and (d) experience of the expected learning outcomes.
Conclusions
On‐campus learning activities within a flipped classroom design could support students’ experiences of confidence in and mastery of physiology. However, the study participants found learner‐centred activities challenging and described feeling doubtful of their ability to master physiology. A didactic framework could take into account the circumstance that students perceive educational technology differently. When designing on‐campus activities, emphasis should be placed on collaboration rather than competition to help students develop confidence in their knowledge of physiology.publishedVersio
The IκB-protein BCL-3 controls toll-like receptor-induced MAPK activity by promoting TPL-2 degradation in the nucleus
Proinflammatory responses induced by Toll-like receptors (TLRs) are dependent on the activation of the NF-ĸB and mitogen-activated protein kinase (MAPK) pathways, which coordinate the transcription and synthesis of proinflammatory cytokines. We demonstrate that BCL-3, a nuclear IĸB protein that regulates NF-ĸB, also controls TLR-induced MAPK activity by regulating the stability of the TPL-2 kinase. TPL-2 is essential for MAPK activation by TLR ligands, and the rapid proteasomal degradation of active TPL-2 is a critical mechanism limiting TLR-induced MAPK activity. We reveal that TPL-2 is a nucleocytoplasmic shuttling protein and identify the nucleus as the primary site for TPL-2 degradation. BCL-3 interacts with TPL-2 and promotes its degradation by promoting its nuclear localization. As a consequence, Bcl3−/− macrophages have increased TPL-2 stability following TLR stimulation, leading to increased MAPK activity and MAPK-dependent responses. Moreover, BCL-3–mediated regulation of TPL-2 stability sets the MAPK activation threshold and determines the amount of TLR ligand required to initiate the production of inflammatory cytokines. Thus, the nucleus is a key site in the regulation of TLR-induced MAPK activity. BCL-3 links control of the MAPK and NF-ĸB pathways in the nucleus, and BCL-3–mediated TPL-2 regulation impacts on the cellular decision to initiate proinflammatory cytokine production in response to TLR activation
Efficacy of Online Training for Improving Camp Staff Competency
Preparing competent staff is a critical issue within the camp community. This quasi-experimental study examined the effectiveness of an online course for improving staff competency in camp healthcare practices among college-aged camp staff and a comparison group (N = 55). We hypothesized that working in camp would increase competency test scores due to opportunities for staff to experientially apply knowledge learned online. Hierarchical linear modeling was used to analyse the cross-level effects of a between-individuals factor (assignment to experimental or comparison group) and within-individual effects of time (pre-test, post-test #1, and post-test #2) on online course test scores. At post-test #2, the difference in average test scores between groups was ~30 points, with the treatment group scoring lower on average than the comparison group. Factors that may have influenced these findings are explored, including fatigue and the limited durability of online learning. Recommendations for research and practice are discussed
An Electrochemical Study of Frustrated Lewis Pairs: A Metal-free Route to Hydrogen Oxidation
[Image: see text] Frustrated Lewis pairs have found many applications in the heterolytic activation of H(2) and subsequent hydrogenation of small molecules through delivery of the resulting proton and hydride equivalents. Herein, we describe how H(2) can be preactivated using classical frustrated Lewis pair chemistry and combined with in situ nonaqueous electrochemical oxidation of the resulting borohydride. Our approach allows hydrogen to be cleanly converted into two protons and two electrons in situ, and reduces the potential (the required energetic driving force) for nonaqueous H(2) oxidation by 610 mV (117.7 kJ mol(–1)). This significant energy reduction opens routes to the development of nonaqueous hydrogen energy technology
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