Cristina Almeida Aguiar

Podcasts in Higher Education: Students’ and Lecturers’ Perspectives

This paper reports the use of podcasts in blended-learning at the University of Minho, in Portugal. Six lecturers created their own podcasts with different purposes in order to support their undergraduate and graduate courses and their students’ (n=318) learning. The reported study belongs to a broader project about the impact of podcasts in blended-learning and it reports data from two semesters. Results give evidence of students’ acceptance regarding podcasts although they do not yet make use of the advantages of media and mobile technologies. The lecturers considered podcasts worthwhile for teaching and for students to learn, but they are time-consuming and there is no institutional recognition. In spite of this, they intend to continue using podcasts in their courses.

Use of short podcasts to reinforce learning outcomes in biology

Received for publication, March 31, 2009Cristina Aguiar‡, Ana Ame´lia Carvalho§, and Carla Joana Carvalho§From the ‡CBMA/Departamento de Biologia, Universidade do Minho, Braga 4710-057, Portugal,§Instituto de Educac e Psicologia, Universidade do Minho, Braga 4710-057, PortugalPodcasts are audio or video files which can be auto-matically downloaded to one’s computer when theepisodes become available, then later transferred to aportable player for listening. The technology thereby enablesthe user to listen to and/or watch the content anywhereat any time. Formerly popular as radio shows, podcast-ing was rapidly explored and used in different areas andwith several purposes, due to the facility of its produc-tion, editing, and distribution. Higher education was noexception and several universities around the world,aware of the audio power of easy online access, havebeen stimulating the use of podcasts [1–4]. Most of thestudies have been using audio files [5–7] but video files(vodcasts or vidcasts) or a record with images (enhancedpodcast) can also be produced. Another type of podcastis a screen capture with a recorded voice (screencast)generally used for demonstrating a task or tutorial on acomputer screen.Some authors claim that it is a renaissance of audiofor learning, though digital audio content would neverreplace reading, listening to live presentations, or themultitude of other ways of obtaining information [2, 6, 8].Audio can effectively be a great way to deliver informa-tion especially for auditory learners [8, 9] and the possi-bility to stop, start, and replay makes it very appropriatefor students with special needs or different learningpaces. According to several authors [2, 6, 10, 11] audiocan have pedagogical advantages because the spokenword can influence both cognition and motivation. Fur-thermore, voice is personal and its frequencies allow theadjustment of intonation, inflection, phrasing, pacing,volume, loudness, and timbre.In higher education, podcasts may be created forseveral purposes such as vocabulary revision, listeningexercises, interviews with native speakers, summaries ofa lecture or lectures, describing homework assignments,giving feedback, guidelines, reducing the effects of isola-tion, promoting inclusivity, developing students’ studyskills through collaborative learning, providing guidance,and so on [1, 5–7, 12–14]. Also, podcasting has beenproposed as a way of changing teacher practices and tomotivate students through innovation [2, 6, 8].Several recommendations should be followed whenproducing podcasts. Podcast length should undoubtedlybe related to its content and purpose. However, toavoid the loss of attention in listening, a general rulewould be to produce short podcasts [5–7], around 1 to5 min length [15]. Podcasts should have technicalquality, being important to produce episodes free ofbackground noise, tinny-sounding, and verbal mistakesthat interrupt the flow of the podcast. It is also impor-tant to engage listeners and keep their attentionthrough the entire episode, preferably by keeping pod-casts short and simple, clear and concise, lively andentertaining [5, 16, 17].

Antimicrobial and antioxidant properties of propolis ethanol extracts from Terceira Island (Azores, Portugal)

Bees produce a resinous mixture named propolis known to have several functions in the beehive, namely structural and sanitary [1,2]. Propolis presents a rich and complex chemical composition, imparted from the several plant materials collected, and several compounds and extracts have been associated with biological activities of high interest [3]. This study focuses on the antimicrobial activity and antioxidant capacity of ethanolic extracts (EE) obtained from propolis samples collected in 2010, in five different areas of the Terceira Island (Azores Archipelago). Antimicrobial activity was evaluated by dilution assay incorporating different EE concentrations in solid media. Bacteria and yeasts of clinical and agrofood relevance were used as indicators of susceptibility. The results showed that Gram-positive bacteria displayed more resistance (best MIC value 200 μg/ml) than the Gram-negative (100 μg/ml). Extracts with higher antibacterial activity (e.g. EE4 and EE5) were generally distinct from those with greater activity against yeast (EE1), but species-specific susceptibilities and extract-specific efficacies against particular microorganisms were also observed, only EE1 was effective against S. epidermidis. A relationship between propolis macroscopic characteristics (colour, hardness and odour) and its antifungal activity was noticed. If confirmed for a broader range of samples, this relationship may constitute an important diagnostic tool. The antioxidant capacity was assessed using cyclic voltammetry [4]. EE4 and EE5 showed the highest antioxidant capacities (39.6 and 23.5 mM eq. gallic acid, respectively), in agreement with results from the antimicrobial assays. Chemical characterization of all EE are underway. Despite being collected in a somewhat confined geographic area propolis samples exhibited diverse antimicrobial activities with different efficiencies and antioxidant capacities.