14098 research outputs found
Sort by
Exploring Math Moments: Middle-Schoolers’ Phases Of Problem-Solving, Executive Functions In Practice, And Collaborative Problem Solving
No full textCollaborative problem solving (CPS) has been shown to both engage and benefit students’ learning of mathematics. However, there is evidence that group work is not always easy to facilitate, in part because educators lack details about learners’ engagement during group work: the processes of problem solving involved, and how these are engaged. In this exploratory study, we focused on these processes in the moments of related math activity, or math moments, engaged by two groups of interested, urban, middle-school aged students during four sessions of work in the Virtual Math Teams (VMT) environment. We examined three phases of their problem solving: Exploring, Constructing, and Checking. In addition, to further describe the students’ cognitive and behavioral engagement, we considered both the process of students\u27 use of executive functions (EF), during problem solving, termed executive functions in practice (EFP), as well as the stage of CPS (Participation, Cooperation, and Collaboration), during phases of problem solving. We learned that the relation between each phase of problem solving, categories of EFP, and stages of CPS vary; for example, the problem-solving phase of Exploring was found to have a more positive effect on EFP and CPS than either Constructing or Checking. Implications for educational practice, and next steps for related research are described
Distinguishing Classes Of Neuroactive Drugs Based On Computational Physicochemical Properties And Experimental Phenotypic Profiling In Planarians
No full textMental illnesses put a tremendous burden on afflicted individuals and society. Identification of novel drugs to treat such conditions is intrinsically challenging due to the complexity of neuropsychiatric diseases and the need for a systems-level understanding that goes beyond single molecule-target interactions. Thus far, drug discovery approaches focused on target-based in silico or in vitro high-throughput screening (HTS) have had limited success because they cannot capture pathway interactions or predict how a compound will affect the whole organism. Organismal behavioral testing is needed to fill the gap, but mammalian studies are too time-consuming and cost-prohibitive for the early stages of drug discovery. Behavioral medium-throughput screening (MTS) in small organisms promises to address this need and complement in silico and in vitro HTS to improve the discovery of novel neuroactive compounds. Here, we used cheminformatics and MTS in the freshwater planarian Dugesia japonica–an invertebrate system used for neurotoxicant testing–to evaluate the extent to which complementary insight could be gained from the two data streams. In this pilot study, our goal was to classify 19 neuroactive compounds into their functional categories: antipsychotics, anxiolytics, and antidepressants. Drug classification was performed with the same computational methods, using either physicochemical descriptors or planarian behavioral profiling. As it was not obvious a priori which classification method was most suited to this task, we compared the performance of four classification approaches. We used principal coordinate analysis or uniform manifold approximation and projection, each coupled with linear discriminant analysis, and two types of machine learning models–artificial neural net ensembles and support vector machines. Classification based on physicochemical properties had comparable accuracy to classification based on planarian profiling, especially with the machine learning models that all had accuracies of 90–100%. Planarian behavioral MTS correctly identified drugs with multiple therapeutic uses, thus yielding additional information compared to cheminformatics. Given that planarian behavioral MTS is an inexpensive true 3R (refine, reduce, replace) alternative to vertebrate testing and requires zero a priori knowledge about a chemical, it is a promising experimental system to complement in silico cheminformatics to identify new drug candidates
The RNA Chaperone Protein ProQ Is A Pleiotropic Regulator In Enteropathogenic \u3cem\u3eEscherichia coli\u3c/em\u3e
No full textEnteropathogenic Escherichia coli (EPEC) is a gastrointestinal pathogen that affects individuals of all age groups, with infections ranging from subclinical colonization to acute or persistent diarrhea. The bacterium\u27s ability to cause diarrhea depends on the locus of enterocyte effacement (LEE) pathogenicity island. Although regulation of the LEE has been systematically characterized, until the last decade, studies mainly focused on its transcriptional control. Posttranscriptional regulation of the LEE continues to be an underappreciated and understudied area of gene regulation. In the past few years, multiple reports have shed light on the roles of RNA-binding proteins, such as Hfq and CsrA, that modulate virulence in EPEC. This study was undertaken to explore the role of another RNA chaperone protein, ProQ, in the pathophysiology of EPEC. Our results suggest that deletion of proQ globally derepresses gene expression from the LEE in lysogeny broth (LB) suggesting that ProQ is a negative regulator of the LEE. Further interrogation revealed that ProQ exerts its effect by downregulating the expression of PerC – a prominent transcriptional activator of the LEE-encoded master regulator ler, which, in turn leads to the observed repression from the other LEE operons. Furthermore, ProQ appears to moonlight as it affects other physiological processes including type IV pili biogenesis, flagellar-dependent motility, biofilm formation, tryptophan metabolism, and antibiotic resistance. Our study provides the very first evidence to implicate ProQ as a pleiotropic regulator in EPEC
Conformational Change In A Four-Tetrad DNA G-Quadruplex Upon Intercalation Of A Small-Molecule Ligand PyDH2
No full textG-quadruplexes (G4s) are non-canonical DNA structures implicated in a number of biological processes. Small-molecule ligands can alter stability and folding of G4s, which can potentially be exploited for therapeutic purposes. In this work, we investigate the interaction of telomeric DNA fragment from Tetrahymena thermophila (TET25, 5′-G(TTGGGG)₄-3′) with a G4 ligand PyDH2 belonging to the bisquinolinium family. When alone, TET25 adopts a mixture of three conformations, with the most abundant being a four-tetrad hybrid G4. In the presence of PyDH2, surprisingly, TET25 folds into an antiparallel chair G4, with PyDH2 intercalated between G-tetrads 2 and 3, according to our crystal structure. The structure represents the second example, and the first crystallographic evidence, of ligand intercalation into a G4. In solution, the interaction of PyDH2 and TET25 leads to a number of complexes differing by G4 topology and binding stoichiometry, strong stabilization of G4 (∆Tₘ = 12.4 °C in the presence of one equiv. of PyDH2) and large hysteresis of ∼10 °C, suggesting that ligand binding and G4 folding processes are complex
Korean Pioneers: The History, Identity, and Legacy of the First Korean Americans
No full textIn examining Korean American history, the starting date for their arrival is conventionally recognized as 1903, when roughly 7,000 laborers migrated to Hawaii. This first wave consisted primarily of young men, many of whom didn’t plan to stay in the US. However, as their stays continued and other Koreans continued migrating, they began developing a unique cultural identity within the United States. This paper aims to determine the unique identities that developed during this first wave of immigration between 1903 and 1945, how they assimilated, and how they interacted with other ethnic minorities and later waves of Korean immigrants.
The research revolves around the specific wave of Korean immigration in the early 1900s. The paper will explore census data, personal accounts, and general literature written on the Korean immigration experience. Similarly, I aim to include a geographic element, examining how differences emerged between Koreans who moved to Hawaii, California, and the Mountain West. Through these varied lenses, it should become clear how the first Korean immigrants to the US developed a distinct cultural footprint and how that identity established a legacy for future Korean immigrants
Privatisation and Toleration: How the Eighteenth-Century Enlightenment Impacted European Attitudes Towards Religion
No full textFor centuries, scholars have debated the significance of the Enlightenment in its impact on European attitudes to religion. On one hand, many scholars immediately following the eighteenth century saw the period as a particularly anti-religious one. For many, particularly at the popular level, the supposed birth of toleration during the Enlightenment and the post-Renaissance rise of free thought and rationalism brought about a dramatic shift in opinions and attitudes towards religion—manifesting, particularly, in the widespread acceptance of irreligion. Today, most historians adopt a more cautious approach, recognising that rarely does history conform to such simple narratives. This paper seeks to understand how the eighteenth-century Enlightenment may have affected European attitudes to religion. It makes a modest case for an acceleration in the field of toleration—in both reform and rhetoric—and the privatisation of religious faith in the eighteenth century, through dominant intellectual practice and through the growth of the Pietistic and Evangelical movements. Ultimately, it argues that the Enlightenment on its own did not greatly affect people’s attitudes to religion; rather, it accelerated and in some respects strengthened changes that were already evident before the eighteenth century
Writing in the Aftermath of War: Literature and Disenchantment in Postwar Central America
No full textThis article examines the challenges faced by Central American writers during a period of profound cultural, political, and economic change, as Central America transitioned from an era of civil war and revolutionary struggle to one of peace, democracy, and neoliberal state-building, spanning from the 1990s to the 2010s. At the core of this change was a pervasive sense of disenchantment, understood not merely as disillusionment with the failures of the peacebuilding process but as a hollowing out of society’s capacity to envision Central American reality on a broader and more meaningful scale. This deeper, more intractable aspect of disenchantment and its implications for the literary enterprise are the focus of this article. I argue that the forces shaping Central America’s postwar modernity have profoundly undermined the groundwork of affectivity, imagination, and memory that literature’s humanizing potential depends on. As a result, Central American writers face the paradoxical task of upholding their literary vocation when literature’s power to produce aesthetic and emancipatory experiences is in decline