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Situated learning theory offers a theoretical modality for promoting a knowledge, skilled, and ethically adept future geoscience workforce. Features of situated learning pedagogies include field-based instruction and situating students within a community of practice. While there is an assumed value of such approaches, there is limited research exploring why and how these situated approaches are beneficial for students. Situated learning theory is an underutilised framework applied among geoscience education researchers, which emphasises legitimate peripheral participation in communities of practice. In this paper, our research objective was to systematically explore the ways scholars have applied situated learning theory in post-secondary geoscience curricula. To address our research objective, we utilised systematic literature review procedures, wherein we collected and synthesised ten articles extracted from several prominent sources that featured peer-reviewed scholarship for geoscience education research. To analyse articles, we developed a coding framework both deductively from the core tenants of situated learning theory and inductively based on how articles had applied the framework. Thematically, using the codes as a guide, we identified 3 themes highlighting trends in scholars' application of situated learning theory to undergraduate geoscience curricula, (1) instructional practices, (2) student outcomes, and (3) assessment techniques. Using the codes and themes, this study provides a framework to guide others who aspire to integrate situated learning theory into geoscience curricula.

BackgroundTwo single-nucleotide polymorphisms (SNPs) (rs4281084 and rs12155594) within the neuregulin-1 (NRG1) gene have been associated with psychosis transition. However, the neurobiological changes associated with these SNPs remain unclear. We aimed to determine what relationship these two SNPs have on lateral ventricular volume and white matter integrity, as abnormalities in these brain structures are some of the most consistent in schizophrenia.MethodsStructural (n = 370) and diffusion (n = 465) magnetic resonance imaging data were obtained from affected and unaffected individuals predominantly of European descent. The SNPs rs4281084, rs12155594, and their combined allelic load were examined for their effects on lateral ventricular volume, fractional anisotropy (FA) as well as axial (AD) and radial (RD) diffusivity. Additional exploratory analyses assessed NRG1 effects on gray matter volume, cortical thickness, and surface area throughout the brain.ResultsIndividuals with a schizophrenia age of onset ⩽25 and a combined allelic load ⩾3 NRG1 risk alleles had significantly larger right (up to 50%, padj = 0.01) and left (up to 45%, padj = 0.05) lateral ventricle volumes compared with those with allelic loads of less than three. Furthermore, carriers of three or more risk alleles, regardless of age of onset and case status, had significantly reduced FA and elevated RD but stable AD in the frontal cortex compared with those carrying fewer than three risk alleles.ConclusionsOur findings build on a growing body of research supporting the functional importance of genetic variation within the NRG1 gene and complement previous findings implicating the rs4281084 and rs12155594 SNPs as markers for psychosis transition. [ABSTRACT FROM AUTHOR]

The mixed-lineage leukemia gene (MLL) is associated with more than 25 chromosomal translocations involving band 11q23 in diverse subtypes of human acute leukemia. Conditional expression of a 50 kDa amino terminal fragment spanning the AT hook motifs of MLL (MLL3AT) causes cell cycle arrest, upregulation of p21Cip1 and p27KiP1 and partial monocytic differentiation of the monoblastic U937 cell line, suggesting a major role for MLL3AT in MLL-AF9-induced myelomonocytic differentiation. In this study, we analyzed the subcellular localization of conditionally expressed MLL3AT in both U937 and HeLa cell lines. Immunofluorescence staining, confocal laser scanning microscopy and immunoelectron microscopy indicated that MLL3AT, like endogenous MLL, localized in the nucleoplasm in a punctate pattern of distribution, including regions attached to the nuclear envelope and the periphery of the nucleolus. We found that MLL3AT and endogenous MLL were present in interphase nuclear matrices and colocalized with topoisomerase II to mitotic chromosomal scaffolds. Nucleoplasm and nucleolar localization was observed even for MLL-AF9 and MLL-AF4 conditionally expressed chimeric proteins, suggesting a common target conferred by the amino terminus of MLL to many if not all the chimeric MLL proteins. The nuclear matrix/scaffold association suggests a role for the amino terminus of MLL in the modulation of chromatin structure, leading to epigenetic effects on the maintenance of gene expression. [ABSTRACT FROM AUTHOR]

Antioxidant metabolism has been examined in red spruce growing at two sites with similar levels of ozone pollution but different winter temperatures. The northern site was Whiteface Mountain, New York with a latitude of 44° 31' (NY). The southern site was Whitetop Mountain, Virginia with a latitude of 30° 54' (VA). The northern site has lower winter temperatures. At the NY site two populations of trees were defined with respect to cold tolerance. An effort was made to establish a temporal relationship between the antioxidant capacity of conifer needles on one hand and the different stages of winter hardening/dehardening, and the induction of dormancy, on the other. The hypothesis tested was that winter injury of red spruce was due to an increased demand for glutathione at levels exceeding the inherent capacity of the needles and/or the altered activities of glutathione reductase. In the autumn, as temperatures began to decrease, photosynthetic potential decreased as spruce entered dormancy. At the same time, cold tolerance (measured as needle electrolyte leakage) gradually increased. Glutathione metabolism appeared to be coupled to these processes. At both sites, seasonal changes in glutathione levels were observed. These changes were found to coincide temporally with the onset and cessation of dormancy (as measured by decline in photosynthetic activity). The same pattern was observed at the northern and the southern site with the winter increases being greater at the former. Glutathione began to increase as soon as needles entered dormancy and began hardening. Glutathione reductase activities closely followed the dehardening process during spring, while glutathione concentration continued to stay relativeIy high with prehardening levels reached only by summer. At the northern site during the winter, cold-tolerant trees had significantly higher glutathione reductase activities compared with cold-sensitive ones. Based on these data, it is proposed that individuals that cannot respond to the increased demand for glutathione reductase activity during the hardening, winter and dehardening periods, become susceptible to winter injury. [ABSTRACT FROM AUTHOR]