The influence of learner-generated domain representations on learning combinatorics and probability theory.

The aim of the current study was to examine the effects of providing support in the form of tools for constructing representations, and in particular the differential effects of the representational format of these tools (conceptual, arithmetical, or textual) in terms of perceived affordances and learning outcomes. The domain involved was combinatorics and probability theory. A between-subjects pre-test–post-test design was applied with secondary education students randomly distributed over four conditions. Participants completed the same tasks in a simulation-based learning environment. Participants in three experimental conditions were provided with a representational tool that could be used to construct a domain representation. The experimental manipulation concerned the format of the tool (conceptual, arithmetical, or textual). Participants in a control condition did not have access to a representational tool. Data from 127 students were analyzed. It was found that the construction of a domain representation significantly improved learning outcomes. The format in which students constructed a representation did not directly affect learning outcomes or the quality of the created domain representations. The arithmetical format, however, was the least stimulating for students to engage in externalizing their knowledge

The effects of representational format on learning combinatorics from an interactive computer simulation

The current study investigated the effects of different external representational formats on learning combinatorics and probability theory in an inquiry based learning environment. Five conditions were compared in a pre-test post-test design: three conditions each using a single external representational format (Diagram, Arithmetic, or Text), and two conditions using multiple representations (Text + Arithmetic or Diagram + Arithmetic). The major finding of the study is that a format that combines text and arithmetics was most beneficial for learning, in particular with regard to procedural knowledge, that is the ability to execute action sequences to solve problems. Diagrams were found to negatively affect learning and to increase cognitive load. Combining diagrams with arithmetical representations reduced cognitive load, but did not improve learning outcomes

Gravitational binding in 4D dynamical triangulation

In the dynamical triangulation model of four dimensional euclidean quantum gravity we investigate gravitational binding. Two scalar test particles (quenched approximation) have a positive binding energy, thereby showing that the model can represent gravitational attraction.Comment: 19 pages, LaTeX2e, version as accepted by Nucl Phys

Development of an NGS-based workflow for improved monitoring of circulating plasmids in support of risk assessment of antimicrobial resistance gene dissemination

Antimicrobial resistance (AMR) is one of the most prominent public health threats. AMR genes localized on plasmids can be easily transferred between bacterial isolates by horizontal gene transfer, thereby contributing to the spread of AMR. Next-generation sequencing (NGS) technologies are ideal for the detection of AMR genes; however, reliable reconstruction of plasmids is still a challenge due to large repetitive regions. This study proposes a workflow to reconstruct plasmids with NGS data in view of AMR gene localization, i.e., chromosomal or on a plasmid. Whole-genome and plasmid DNA extraction methods were compared, as were assemblies consisting of short reads (Illumina MiSeq), long reads (Oxford Nanopore Technologies) and a combination of both (hybrid). Furthermore, the added value of conjugation of a plasmid to a known host was evaluated. As a case study, an isolate harboring a large, low-copymcr-1-carrying plasmid (>200 kb) was used. Hybrid assemblies of NGS data obtained from whole-genome DNA extractions of the original isolates resulted in the most complete reconstruction of plasmids. The optimal workflow was successfully applied to multidrug-resistantSalmonellaKentucky isolates, where the transfer of an ESBL-gene-containing fragment from a plasmid to the chromosome was detected. This study highlights a strategy including wet and dry lab parameters that allows accurate plasmid reconstruction, which will contribute to an improved monitoring of circulating plasmids and the assessment of their risk of transfer

Співставлення чіткого та нечіткого підходів до розв’язку задач інформаційної безпеки

Проведено порівняння чіткого та нечіткого підходів із метою виявлення їх спільних рис та відмінностей. У задачі розподілу ресурсів захисту інформації проаналізовано принципи формування функцій належності до нечітких множин і їх вплив на кінцеві результати. Показано, що нечіткий підхід дає змогу оптимізувати показники системи захисту інформації за рахунок раціонального вибору функцій належності, які відображають основну характеристику об’єктів — їх динамічну вразливість. На прикладі системи з двох об’єктів із різними вразливостями встановлені умови, за яких досягається найвищий рівень співпадіння результатів у разі використання двох підходів. Методика може бути використана під час розрахунку допустимих витрат в інформаційних системах із довільною кількістю об’єктів, котрі відрізняються кількістю розміщеної інформації, вразливістю та рівнем допустимих втрат. Окреслені шляхи подальшого застосування приведеної методики в задачах інформаційної безпеки.Проведено сравнение четкого и нечеткого подходов с целью выявления их общих черт и различий. В задаче распределения ресурсов защиты информации проанализированы принципы формирования функций принадлежности к нечетким множествам и их влияние на конечные результаты. Показано, что нечеткий подход дает возможность оптимизировать показатели системы защиты информации за счет рационального выбора функций принадлежности, которые отражают основную характеристику объектов — их динамическую уязвимость. На примере системы из двух объектов с различными уязвимостями установлены условия, при которых достигается наивысший уровень совпадения результатов при использовании двух подходов. Методика может быть использована при расчете допустимых затрат в информационных системах с произвольным количеством объектов, которые отличаются объемом размещенной информации, уязвимостью и уровнем допустимых потерь. Обозначены пути дальнейшего применения приведенной методики в задачах информационной безопасности.A comparison of explicit and fuzzy approaches to identify their similarities and differences is carried out. In the problem of distribution of resources of information protection the principles of the formation of the membership functions to the fuzzy sets and their effect on the final results are analyzed. It is shown that the fuzzy approach gives the possibility to optimize the indicators of the system of information security through a rational choice of the membership functions, which reflect the basic characteristic of the objects - their dynamic vulnerability. Through the example of the system of two objects with different vulnerabilities the conditions under which the highest level of results coincidence is achieved using two approaches are established. The technique can be used when calculating the eligible costs of information systems with an arbitrary number of objects that have different volume of the placed information, vulnerability and level of acceptable losses. The ways of further application of the method in problems of information security are identified