Why 'scaffolding' is the wrong metaphor : the cognitive usefulness of mathematical representations.

The metaphor of scaffolding has become current in discussions of the cognitive help we get from artefacts, environmental affordances and each other. Consideration of mathematical tools and representations indicates that in these cases at least (and plausibly for others), scaffolding is the wrong picture, because scaffolding in good order is immobile, temporary and crude. Mathematical representations can be manipulated, are not temporary structures to aid development, and are refined. Reflection on examples from elementary algebra indicates that Menary is on the right track with his ‘enculturation’ view of mathematical cognition. Moreover, these examples allow us to elaborate his remarks on the uniqueness of mathematical representations and their role in the emergence of new thoughts.Peer reviewe

Оценка эффективности хирургического метода у больных с EGFR-мутированной аденокарциномой легкого III–IV стадии после терапии ингибиторами тирозинкиназы

Objective. To assess the overall and disease-free survival rates in patients with EGFR-mutated lung adenocarcinoma, who underwent surgery after achieving the objective response to tyrosine kinase inhibitor (TKI) therapy.Material and Methods. The overall and disease-free survival rates were analyzed in 18 patients with EGFR-positive lung adenocarcinoma, which was inoperable at presentation due to locally advanced disease or the evidence of distant metastasis. In accordance with the clinical standards, patients were recommended for TKI therapy. Surgical resection was performed after achieving the objective tumor response to TKI therapy. The control group included 23 patients with EGFR mutation-positive lung adenocarcinoma, who did not undergo surgery after receiving TKI therapy.Results. The study revealed a statistically significant effect of surgical resection on the overall survival (OS) in patients with EGFR mutation-positive stage III–IV lung adenocarcinoma after response to TKI therapy (p=0.004). However, there was no statistically significant effect on the disease-free survival (DFS) (p=0.40). There was a tendency to increase in the median OS in patients of the study group (46 months) compared to that in patients of the control group (26 months). Surgery in the study group was characterized with some technical difficulties associated with severe fibrosis. However, this did not affect the duration of surgery and the volume of blood loss.Conclusion. Tumor resection in patients with EGFR mutation-positive stage III–IV lung adenocarcinoma is feasible and safe, but requires highly qualified team surgeons in well-equipped medical centers. Our study revealed that the combination of EGFR-TKI and tumor resection provided better PFS and OS than EGFR-TKI alone. However, further studies are required.Цель исследования ‒ оценить показатели общей и безрецидивной выживаемости у пациентов с EGFR-мутированной аденокарциномой легкого, у которых выполнено хирургическое вмешательство после развития объективного ответа на прием ингибиторов тирозинкиназы (ИТК).Материал и методы. Проанализированы показатели общей и безрецидивной выживаемости 18 больных аденокарциномой легкого с наличием активирующей EGFR-мутации, изначально неоперабельных из-за местнораспространенного опухолевого процесса или наличия отдаленного метастазирования. В соответствии со стандартами оказания специализированной медицинской помощи пациентам был рекомендован прием ИТК. Выполнение хирургических вмешательств оказалось возможным после получения объективного ответа опухоли («stage down») на таргетную терапию. В группу сравнения включено 23 больных аденокарциномой легкого с EGFR-позитивным мутационным статусом, получавших ИТК, но без оперативного вмешательства.Результаты. Выявлено значимое влияние хирургического вмешательства на показатели общей выживаемости (ОВ) у больных EGFR-мутированной аденокарциномой легкого III–IV стадии после приема ИТК (р=0,004). Однако значимого влияния на безрецидивную выживаемость (БРВ) не отмечено (р=0,40). Выявлена тенденция к увеличению медианы ОВ у пациентов исследуемой группы (46 мес) по сравнению с контрольной группой (26 мес). По сравнению со стандартным объемом хирургического вмешательства операции, выполненные у исследуемой группы пациентов, отличались техническими сложностями, связанными с выраженным фиброзом при выделении элементов корня легкого и выполнении лимфодиссекции, но не отличались по длительности и объему кровопотери.Заключение. Хирургические вмешательства у больных с EGFR-мутированной аденокарциномой легкого III–IV стадии технически выполнимы и безопасны, но для их проведения необходимы опытные бригады специалистов и хорошо оснащенные медицинские центры. Статистические данные свидетельствуют о значимом росте показателей выживаемости после операций как компонента комплексного лечения у данной когорты больных, с использованием ИТК, однако данное направление требует дальнейшего изучения

"Just the Boys Playing on Computers": An Activity Theory Analysis of Differences in the Cultures of Two Engineering Firms

Using activity theory as a supplement to genre studies, this article explores a case of the disintegration of a traditional engineering firm. It focuses on the causes of such disintegration and the role of different types of communication in serving as sites where contradictions can be brought to visibility and resolution. The authors' goal is both to show the power of activity theory in illuminating issues of tension, contradiction, and dissonance that lead to the breakup of the original organization into two separate firms and point to fundamental differences in the cultures of traditional engineering firms and software design enterprises

From diagnosis toward academic support: Developing a disciplinary, esp-based writing task and rubric to identify the needs of entering undergraduate engineering students

This paper reports on the central role of disciplinary (engineering) criteria in the development of an ESP-based diagnostic writing task and rubric, used to identify entering undergraduate engineering students in need of academic support. In this mixed methods study, Phase 1 investigated the usefulness of a generic writing task and analytic rubric used for the diagnosis. Phase 2, informed by the results of Phase 1, focused on the development of an engineering writing task. The outcomes of the two phases were merged to develop an engineering ESP-based writing task and rubric, informed by a) the collaboration of language/writing experts and engineering stakeholders, and b) criteria, indigenously drawn from the engineering community of practice. The study supports an academic literacies approach in diagnostic assessment (rather than a generic, one-size-fits-all, 'academic literacy' approach), and suggests that the demands of university study are best viewed as the practices of disciplinary communities of practice. The paper provides evidence of the increased meaningfulness and usefulness of a disciplinary, ESP-based approach in diagnosing need for academic support