The secreted Ipa complex of Shigella flexneri promotes entry into mammalian cells.

The bacterial pathogen Shigella flexneri causes bacillary dysentery in humans by invading coloncytes. Upon contact with epithelial cells, S. flexneri elicits localized plasma membrane projections sustained by long actin filaments which engulf the microorganism. The products necessary for Shigella entry include three secretory proteins: IpaB, IpaC, and IpaD. Extracellular IpaB and IpaC associate in a soluble complex, the Ipa complex. We have immunopurified this Ipa complex on latex beads and found that they were efficiently internalized into HeLa cells. Like S. flexneri entry, uptake of the beads bearing the Ipa complex was associated with membrane projections and polymerization of actin at the site of cell-bead interaction and was dependent on small Rho GTPases. These results indicate that a secreted factor can promote S. flexneri entry into epithelial cells.

Disulfide oxidoreductase activity of Shigella flexneri is required for release of Ipa proteins and invasion of epithelial cells.

Secretion of IpaB, IpaC, and IpaD proteins of Shigella flexneri, essential for the invasion of epithelial cells, requires a number of proteins encoded by the spa and mxi loci on the large plasmid. Introduction of dsbA::Tn5 into S.flexneri from Escherichia coli K-12 reduced invasiveness, which resulted from a decrease in the capacity to release IpaB, IpaC, and IpaD proteins into the external medium. Examination of the surface-presented Ipa proteins of the dsbA mutant, however, revealed Ipa proteins at levels similar to those on wild-type cells. Since the defective phenotype was similar to that of the spa32 mutant of S. flexneri and the Spa32 sequence possessed two Cys residues, the effect of dsbA mutation of the folding structure of Spa32 under reducing conditions and on the surface expression of Spa32 was investigated. The results indicated that Spa32 was a disulfide-containing protein whose correctly folded structure was required for its presentation on the outer membrane. Indeed, replacing either one of the two Cys residues in Spa32 with Ser by site-directed mutagenesis reduced its capacity to release Ipa proteins into the external medium and led to the accumulation of Spa32 protein in the periplasm. These results indicated that the DsbA protein performs an essential function during the invasion of mammalian cells, by facilitating transport of the Spa32 protein across the outer membrane.

Fundamentos de percepción visual

IMPORTANTE: CÓMO LEERLO. El libro se puede descargar desde el Repositorio de la Universidad de Alicante. Al tratarse de un libro con gran número de animaciones, gifs, vídeos y enlaces a internet, es conveniente abrirlo mediante un lector para epub3, aunque en cualquier otro lector la parte de texto es totalmente accesible. Está optimizado para el lector ibooks del iPad, se puede leer por ejemplo mediante el lector Gitden para Android, mediante los lectores Azardi y Adobe Digital Edition 4.5 para PC o añadiendo el complemento para epub en el navegador Mozilla. Para los usuarios de iPad: al bajar el archivo epub desde la plataforma RUA directamente al dispositivo no se reconoce el formato, por lo que la aplicación ibooks no lo abre. Para evitarlo, recomendamos bajar el fichero en un ordenador y llevarlo al iPad, vía conexión por cable o a través de una nube de datos (la aplicación Dropbox es gratis).

HELPING YOUTH WITH AUTISM SPECTRUM DISORDER DEVELOP SOCIAL COMPETENCE IN COMMUNITY-BASED SETTINGS

The purpose of the current dissertation is to identify the features of effective interventions by exploring the experiences of youth with ASD who participate in such interventions, through two intervention studies (Studies 1 and 2) and one interview study (Study 3). Studies 1 and 2 were designed to support the development of social competence of youth with ASD through Structured Play with LEGO TM (Study 1, 12 youths with ASD, ages 7–12) and Minecraft TM (Study 2, 4 youths with ASD, ages 11–13). Over the course of the sessions, the play of the youth developed from parallel play (children playing alone, without interacting) to co-operative play (playing together with shared objectives). The results of Study 2 showed that rates of initiations and levels of engagement increased from the first session to the final session. In Study 3, 12 youths with ASD (ages 10–14) and at least one of their parents were interviewed to explore what children and their parents want from programs designed to improve social competence, which activities and practices were perceived to promote social competence by the participants, and which factors affected their decisions regarding these programs. The adolescents and parents looked for programs that supported social development and emotional wellbeing, but did not always have access to the programs they would have preferred, with factors such as cost and location reducing their options. Three overarching themes emerged through analysis of the three studies: (a) interests of the youth; (b) structure, both through interactions and instruction; and (c) naturalistic settings. Adolescents generally engage more willingly in interventions that incorporate their interests, such as play with Minecraft TM in Study 2. Additionally, Structured Play and structured instruction were crucial components of providing safe and supportive contexts for the development of social competence. Finally, skills learned in naturalistic settings tend to be applied more successfully in everyday situations. The themes are analysed through the lens of Vygotsky’s (1978) perspectives on learning, play, and development. Implications of the results for practitioners and researchers are discussed.

A wired - impressa e digital

O tema abordado neste relatório de estágio é a revista Wired impressa vs. digital. Tendo em conta, que uma das primeiras revistas a ser publicadas para Ipad foi a Wired, um periódico icónico que aborda assuntos referentes à tecnologia, decidi realizar uma análise exaustiva desta revista de forma a relacionar estes dois mundos tão díspares. Para tal, dividi este trabalho em duas partes distintas, sendo a primeira delas divididas em dois capítulos. No primeiro capítulo faz-se uma breve contextualização do universo da impressão. No segundo capítulo comparam-se os dois universos visuais da Wired, começando por um enquadramento histórico. Na segunda parte faz-se uma breve descrição da empresa na qual foi realizado um estágio curricular, fazendo ainda referência aos trabalhos desenvolvidos durante esse período.

LCD vs. E-ink: An Analysis of the Reading Behavior

Electronic books (e-book) are an interesting option compared to classic paper books. Most e-reading devices of the first generation were based on e-ink technology. With the appearance of the Apple iPad on the market, TFT-LCDs became important in the field of e-reading. Both technologies have advantages and disadvantages but the question remains whether one or the other technology is better for reading. In the present study we analyzed and compared reading behavior when reading on e-inkreader (e-ink displays) and on tablets (TFT-LCDs) as measured by eye-tracking. The results suggest that the reading behavior on tablets is indeed very similar to the reading behavior on e-ink-reader. Participants showed no difference in fixation duration. Significant differences in reading speed and in the proportion of regressive saccades suggest that tablets, under special artificial light conditions, may even provide better legibility.

Högläsning – En gemensam väg in i språket : En multipel fallstudie av fyra lärares medvetna högläsning i årskurs 4 och i årskurs 6

Studien undersöker och jämför hur fyra lärare arbetar medvetet med sin högläsning i klassrummet och ifall deras arbete förändras mellan årskurs 4 och årskurs 6. Undersökningen är disponerad som en multipel fallstudie, där varje enskilt fall först analyseras separat för att därpå korsanalyseras. För att kunna besvara studiens syfte och frågeställningar genomfördes en empirisk undersökning där de fyra fallen studerades genom metoderna enkät, observation, intervju och deltagarvalidering. Därefter analyserades fallen utifrån den sociokulturella teorin om lärande, skolans styrdokument och tidigare forskning inom ämnesområdet. Resultaten ger en positiv inblick i lärares arbete med högläsning i klassrummet. De didaktiska val som ligger bakom de deltagande lärarnas högläsning går att koppla till läroplanens syfte och centrala innehåll. Lärarna verkar arbeta varierat och eleverna tränas med högläsningen som utgångspunkt i läroplanens övergripande förmågor. Lärarna har alla märkt ett generellt minskat läsintresse hos barn och elever men anser sig överlag inte märka så mycket av detta i sina egna klassrum, vilket de kopplar till att de aktivt arbetar med att läsa högt för eleverna. Vidare anser de att elevernas språkutveckling och ordförståelse gynnas av högläsning då de får lyssna till det skrivna ordet. Studiens lärare är överens om att det är viktigt att avsätta tid till högläsning i undervisningen och använder sig av en dialogisk uppläsning i sina klassrum, där högläsningen blir ett pedagogiskt verktyg. Endast en av lärarna säger sig uttryckligen arbeta med specifika metoder och strategier utifrån ämnesdidaktisk forskning, men vid besöken observerades att även de övriga lärarna intuitivt arbetar implicit med lässtrategier i sin undervisning. Gemensamt för lärarna är att de ofta väljer att arbeta ämnesintegrerat och att högläsningen blir en naturlig del i ett tematiskt arbete. De menar också att behovet av deras högläsning i undervisningen snarast ökar i och med att eleverna blir äldre, då de möts av mer komplexa texter ju äldre de blir.

Tablet App halometer for the assessment of dysphotopsia

Purpose To assess the validity and repeatability of the Aston Halometer. Setting University clinic, United Kingdom. Design Prospective, repeated-measures experimental study. Methods The halometer comprises a bright light-emitting-diode (LED) glare source in the center of an iPad4. Letters subtending 0.21° (∼0.3 logMAR) were moved centrifugally from the LED in 0.05 degree steps in 8 orientations separated by 45 degrees for each of 4 contrast levels (1000, 500, 100, and 25 Weber contrast units [Cw]) in random order. Bangerter occlusion foils were inserted in front of the right eye to simulate monocular glare conditions in 20 subjects (mean age 27.7 ± 3.1 years). Subjects were positioned 2 meters from the screen in a dark room with the iPad controlled from an iPhone via Bluetooth operated by the researcher. The C-Quant straylight meter was also used with each of the foils to measure the level of straylight over the retina. Halometry and straylight repeatability was assessed at a second visit. Results Halo size increased with the different occlusion foils and target contrasts (F = 29.564, P <.001) as expected and in a pattern similar to straylight measures (F = 80.655, P <0.001). Lower contrast letters showed better sensitivity but larger glare-obscured areas, resulting in ceiling effects caused by the screen's field-of-view, with 500 Cw being the best compromise. Intraobserver and interobserver repeatability of the Aston Halometer was good (500Cw: 0.84 to 0.93 and 0.53 to 0.73) and similar to the straylight meter. Conclusion The halometer provides a sensitive, repeatable way of quantifying a patient-recognized form of disability glare in multiple orientations to add objectivity to subjectively reported discomfort glare.

Mobile app reading speed test

Aim: To validate the accuracy and repeatability of a mobile app reading speed test compared with the traditional paper version. Method: Twenty-one subjects wearing their full refractive correction glasses read 14 sentences of decreasing print size between 1.0 and -0.1 logMAR, each consisting of 14 words (Radner reading speed test) at 40 cm with a paper-based chart and twice on iPad charts. Time duration was recorded with a stop watch for the paper chart and on the App itself for the mobile chart allowing critical print size (CPS) and optimal reading speed (ORS) to be derived objectively. Results: The ORS was higher for the mobile app charts (194±29 wpm; 195±25 wpm) compared with the paper chart (166±20 wpm; F=57.000, p<0.001). The CPS was lower for the mobile app charts (0.17±0.20 logMAR; 0.18±0.17 logMAR) compared with the paper chart (0.25±0.17 logMAR; F=5.406, p=0.009). The mobile app test had a mean difference repeatability of 0.30±22.5 wpm, r=0.917 for ORS, and a CPS of 0.0±0.2 logMAR, r=0.769. Conclusions: Repeatability of the app reading speed test is as good (ORS) or better (CPS) than previous studies on the paper test. While the results are not interchangeable with paper-based charts, mobile app tablet-based tests of reading speed are reliable and rapid to perform, with the potential to capture functional visual ability in research studies and clinical practice.

The Effect of Mobile Technology as an Active Student Response System on the Acquisition of U.S. History Content of Secondary Students with Specific Learning Disabilities

Students with specific learning disabilities (SLD) typically learn less history content than their peers without disabilities and show fewer learning gains. Even when they are provided with the same instructional strategies, many students with SLD struggle to grasp complex historical concepts and content area vocabulary. Many strategies involving technology have been used in the past to enhance learning for students with SLD in history classrooms. However, very few studies have explored the effectiveness of emerging mobile technology in K-12 history classrooms. This study investigated the effects of mobile devices (iPads) as an active student response (ASR) system on the acquisition of U.S. history content of middle school students with SLD. An alternating treatments single subject design was used to compare the effects of two interventions. There were two conditions and a series of pretest probesin this study. The conditions were: (a) direct instruction and studying from handwritten notes using the interactive notebook strategy and (b) direct instruction and studying using the Quizlet App on the iPad. There were three dependent variables in this study: (a) percent correct on tests, (b) rate of correct responses per minute, and (c) rate of errors per minute. A comparative analysis suggested that both interventions (studying from interactive notes and studying using Quizlet on the iPad) had varying degrees of effectiveness in increasing the learning gains of students with SLD. In most cases, both interventions were equally effective. During both interventions, all of the participants increased their percentage correct and increased their rate of correct responses. Most of the participants decreased their rate of errors. The results of this study suggest that teachers of students with SLD should consider a post lesson review in the form of mobile devices as an ASR system or studying from handwritten notes paired with existing evidence-based practices to facilitate students’ knowledge in U.S. history. Future research should focus on the use of other interactive applications on various mobile operating platforms, on other social studies subjects, and should explore various testing formats such as oral question-answer and multiple choice.

HELPING YOUTH WITH AUTISM SPECTRUM DISORDER DEVELOP SOCIAL COMPETENCE IN COMMUNITY-BASED SETTINGS

The purpose of the current dissertation is to identify the features of effective interventions by exploring the experiences of youth with ASD who participate in such interventions, through two intervention studies (Studies 1 and 2) and one interview study (Study 3). Studies 1 and 2 were designed to support the development of social competence of youth with ASD through Structured Play with LEGO TM (Study 1, 12 youths with ASD, ages 7–12) and Minecraft TM (Study 2, 4 youths with ASD, ages 11–13). Over the course of the sessions, the play of the youth developed from parallel play (children playing alone, without interacting) to co-operative play (playing together with shared objectives). The results of Study 2 showed that rates of initiations and levels of engagement increased from the first session to the final session. In Study 3, 12 youths with ASD (ages 10–14) and at least one of their parents were interviewed to explore what children and their parents want from programs designed to improve social competence, which activities and practices were perceived to promote social competence by the participants, and which factors affected their decisions regarding these programs. The adolescents and parents looked for programs that supported social development and emotional wellbeing, but did not always have access to the programs they would have preferred, with factors such as cost and location reducing their options. Three overarching themes emerged through analysis of the three studies: (a) interests of the youth; (b) structure, both through interactions and instruction; and (c) naturalistic settings. Adolescents generally engage more willingly in interventions that incorporate their interests, such as play with Minecraft TM in Study 2. Additionally, Structured Play and structured instruction were crucial components of providing safe and supportive contexts for the development of social competence. Finally, skills learned in naturalistic settings tend to be applied more successfully in everyday situations. The themes are analysed through the lens of Vygotsky’s (1978) perspectives on learning, play, and development. Implications of the results for practitioners and researchers are discussed.

Next generation e-learning platform: virtual laboratory simulations

Bioscience subjects require a significant amount of training in laboratory techniques to produce highly skilled science graduates. Many techniques which are currently used in diagnostic, research and industrial laboratories require expensive equipment for single users; examples of which include next generation sequencing, quantitative PCR, mass spectrometry and other analytical techniques. The cost of the machines, reagents and limited access frequently preclude undergraduate students from using such cutting edge techniques. In addition to cost and availability, the time taken for analytical runs on equipment such as High Performance Liquid Chromatography (HPLC) does not necessarily fit with the limitations of timetabling. Understanding the theory underlying these techniques without the accompanying practical classes can be unexciting for students. One alternative from wet laboratory provision is to use virtual simulations of such practical which enable students to see the machines and interact with them to generate data. The Faculty of Science and Technology at the University of Westminster has provided all second and third year undergraduate students with iPads so that these students all have access to a mobile device to assist with learning. We have purchased licences from Labster to access a range of virtual laboratory simulations. These virtual laboratories are fully equipped and require student responses to multiple answer questions in order to progress through the experiment. In a pilot study to look at the feasibility of the Labster virtual laboratory simulations with the iPad devices; second year Biological Science students (n=36) worked through the Labster HPLC simulation on iPads. The virtual HPLC simulation enabled students to optimise the conditions for the separation of drugs. Answers to Multiple choice questions were necessary to progress through the simulation, these focussed on the underlying principles of the HPLC technique. Following the virtual laboratory simulation students went to a real HPLC in the analytical suite in order to separate of asprin, caffeine and paracetamol. In a survey 100% of students (n=36) in this cohort agreed that the Labster virtual simulation had helped them to understand HPLC. In free text responses one student commented that "The terminology is very clear and I enjoyed using Labster very much”. One member of staff commented that “there was a very good knowledge interaction with the virtual practical”.

El consumo tradicional de los nuevos medios. Análisis de la usabilidad de las publicaciones autóctonas para tableta en el contexto universitario español y brasileño

Esta investigación aborda el consumo que los jóvenes universitarios de España y Brasil realizan de las publicaciones para tabletas. A través del estudio de seis casos –las revistas españolas Don, VisàVis y Quality Sport, y los vespertinos brasileños O Globo a Mais, de Río de Janeiro; Estadão Noite, de Sao Paulo; y Diário do Nordeste Plus, de Fortaleza– se aplica una metodología cualitativa, el test de usabilidad, para detectar qué aspectos ralentizan y entorpecen la navegación en las nuevas generaciones de usuarios de medios móviles. A pesar de la influencia de las revistas impresas en la configuración de las publicaciones para tableta, los datos muestran que el usuario necesita “entrenarse” para conocer unas opciones de interacción a veces poco intuitivas o para las que carece de la madurez visual necesaria. Por ello las publicaciones más sencillas obtienen los mejores resultados de usabilidad.

Ämnesbetyg och provbetyg, en undersökning om relationen mellan ämnet matematik och de nationella proven

Denna undersökning handlar om sambandet mellan elevers betyg i ämnet matematik, och deras betyg på de nationella proven i samma ämne. Bakgrundsfakta kring området kommer att presenteras och jag kommer presentera en undersökning där jag samlat in betygen i ämnet matematik och betygen på de nationella proven i matematik från sex olika klasser i årskurs 6. Jag har även utfört en intervju med samtliga sex lärare för de olika klasserna för att få en djupare förståelse för lärarens syn på ämnesbetyg och provbetyg. Tidigare gjord forskning visar att de flesta elever får samma ämnesbetyg i matematik som de får på de nationella proven, men att skillnader finns. Könsaspekten kommer även vara en del av undersökningen då skolverket visar att det finns skillnader i pojkar och flickors resultat. Jag har sammanställt resultaten i tabellform i den första delen av undersökningen och i den andra delen redovisas intervjuerna. I resultatet kan man avläsa att det klassvis finns skillnader mellan ämnesbetyget och betyget på de nationella proven. Resultatet av intervjuerna visar att det finns ett flertal skillnader gällande hur lärare ser på de nationella proven och deras samspel med ämnesbetyget. Tillslut kommer jag diskutera resultaten gentemot den tidigare forskningen för att se huruvida denna undersökning stämmer överens med tidigare forskning samt analysera intervjuernas resultat.

Bilingual Lexical Access in Reading : Analyzing the Effect of Semantic Context on Non-Selective Access in Bilingual Memory

Recent empirical studies about the neurological executive nature of reading in bilinguals differ in their evaluations of the degree of selective manifestation in lexical access as implicated by data from early and late reading measures in the eye-tracking paradigm. Currently two scenarios are plausible: (1) Lexical access in reading is fundamentally language non-selective and top-down effects from semantic context can influence the degree of selectivity in lexical access; (2) Cross-lingual lexical activation is actuated via bottom-up processes without being affected by top-down effects from sentence context. In an attempt to test these hypotheses empirically, this study analyzed reader-text events arising when cognate facilitation and semantic constraint interact in a 22 factorially designed experiment tracking the eye movements of 26 Swedish-English bilinguals reading in their L2. Stimulus conditions consisted of high- and low-constraint sentences embedded with either a cognate or a non-cognate control word. The results showed clear signs of cognate facilitation in both early and late reading measures and in either sentence conditions. This evidence in favour of the non-selective hypothesis indicates that the manifestation of non-selective lexical access in reading is not constrained by top-down effects from semantic context.