Implications of patterns of use of freely-available online formative tests for online summative tasks

The use of online assessment tasks in a summative context can create tensions between the institution’s need for security to ensure the validity of individual evaluations and the student’s need for flexibility of access. This is especially the case in recent years, with the upsurge of students engaged in paid employment while enrolled in full-time study. The lowest rate of engagement of students in paid employment at the three institutions in which our study was based was 65%, the highest 75%. One quarter of all students at this institution spent more than 20 hours a week in paid employment. Ninety seven percent of students in paid work were enrolled on a full-time basis. This study determined from automatically recorded times of logon, individual question submission and whole test submission the patterns of use of online feedback-enriched MCQ tests by 656 students across the three institutions in Perth, Western Australia. The conditions under which the tests were available to students varied from a strictly secured, summative task available for a limited time on campus within hours governed by the accessibility of automatically locked-down computer rooms and the availability of staff for live or video invigilation to a freely accessible formative learning exercise. Mismatches between preferred and available times severe enough to exclude some external students from assessment were identified. Evidence was found that for younger (16-18 year old) students especially, meaningful engagement with test-structured tasks lasts no more than 10 minutes, one third of the designed time of our current summative online tests. The one third, approximately, of enrolled students who did not use the online test facility had significantly poorer academic outcomes. The advantage granted by test use increased substantially with repetition. The question of how to ensure the security and validity of online testing while increasing real flexibility of access remains unresolved for us. We accept the social responsibility of finding a solution

Co-expression analysis of PAX3-positive follicular melanocytes.

<p>A) The transverse section of the hair follicle shows both PAX3 and HES1 co-expressing (enlarged in B), and single PAX3-expressing (enlarged in C), melanocytes in the outer root sheath (ORS). The line circumscribes the hair follicle. PAX3 was labelled with mouse monoclonal antibody (DSHB). D) The longitudinal section of the hair follicle shows PAX3 and MLANA co-expressing (enlarged in the insert on the left) and single PAX3-expressing (enlarged in the insert on the right) melanocytes in the outer root sheath (ORS). E) Single PAX3-expresing (arrows) and PAX3 and MLANA co-expressing (arrowheads) melanocytes in the matrix of the hair bulb. PAX3 was labelled with rabbit polyclonal antibody (Invitrogen).</p

Co-expression of PAX3 and MITF in melanocytic and melanoma cells.

<p>A–C) Double immunofluorescent staining showing co-expression of PAX3 and MITF in: (A) the epidermal melanocytes of normal skin; (B) primary melanoma; and (C) in an A2058 metastatic melanoma cell line. Arrowheads in (A) show PAX3-positive normal epidermal melanocytes. Lines in (A) and (B) demarcate epidermal-dermal border (EDB). The variable PAX3 expression was clearly visible in the A2058 cell line (C). For all these experiments depicted in the figure, PAX3 was labelled with rabbit polyclonal antibody (Invitrogen). D) Graph showing the overall number of MITF and PAX3 double labelled cells in normal skins, naevi, primary melanomas and melanoma metastases. Each column represents a percentage of MITF-positive cells that are also PAX3-positive averaged across all samples. E) Double immunofluorescent staining shows PAX3 and MITF co-expressing melanocytes (yellow-orange) in the bulb of the hair follicle of normal skin. Note the single MITF-labelled melanocytes (green) at the base of the hair.</p

PAX3 expression in melanocytic and melanoma cells.

<p>A) Immunohistochemistry shows PAX3 expression (top panel) in representative samples of normal skin, naevus, primary melanoma and melanoma metastasis, compared to MITF expression in adjacent sections (bottom panel). B–D) Show the distribution of PAX3-positive melanocytes (arrowheads) in normal skin: along the hair follicle (early (B) and late (C) anagen); and in the epidermis (D). Arrows in (D) point to the cytoplasmic melanin deposit distinguishable from the nuclear PAX3 staining (arrowheads). Asterisk in (B) and (C) marks a dermal papilla. PAX3 was labelled with mouse monoclonal antibody (DSHB). E) <i>PAX3</i> expression was analysed by RT-PCR and the graph shows the mean fold increase of <i>PAX3</i> expression in naevi, primary melanomas and lymph node metastases normalised to the expression in normal skin.</p

Co-expression analysis of PAX3-positive epidermal melanocytes of normal skin.

<p>Epidermal melanocytes of normal skin show a variable differentiation status: less differentiated melanocytes co-expressing PAX3 (mouse monoclonal antibody, DSHB) and HES1 (A); more differentiated co-expressing PAX3 (rabbit polyclonal, Invitrogen) and MLANA (B); and mature melanocytes expressing only MLANA (B). Single HES1-labelled cells in the epidermis are keratinocytes (A). C) PAX3 (mouse monoclonal antibody, DSHB) and Ki67 co-expressing melanocytes are also observed in the epidermis of sun-exposed skin. Lines in (A), (B) and (C) demarcate the epidermal-dermal border (EDB) or epidermal surface (ES). D) Graph shows the distribution of differentiation marker expression in normal skin melanocytes with respect to melanocyte location (in epidermis, outer root sheath (ORS), or hair follicle bulb).</p

Co-expression of PAX3 with markers of cell survival and migration in melanocytic and melanoma cells.

<p>A) Double immunofluorescent staining showing PAX3 (mouse monoclonal antibody, DSHB) and BCL2L1 co-expression in representative samples of normal skin, naevus, primary melanoma and melanoma metastasis. B) PAX3 (mouse monoclonal antibody, DSHB) and MCAM co-expression in normal skin (epidermal melanocytes), naevus, primary melanoma and melanoma metastasis. Lines in (A) and (B) demarcate the epidermal-dermal border (EDB) or epidermal surface (ES). C) In contrast to the epidermal melanocytes, some PAX3-positive melanocytes in the outer root sheath (ORS) co-express MCAM. D) Graph showing the overall number of PAX3, BCL2L1 double-labelled cells in normal skins, naevi, primary melanomas and melanoma metastases. Each column represents a percentage of PAX3-positive cells that are also BCL2L1-positive, averaged across all samples. E) Graph showing the overall number of PAX3, MCAM double-labelled cells in normal skins, naevi, primary melanomas and melanoma metastases. Each column represents a percentage of PAX3-positive cells that are also MCAM-positive, averaged across all samples.</p

Is requisite for maintenance of a subpopulation of superior collicular neurons and shows a diverging expression pattern to during superior collicular development-1

Nerated at E11 populate the SS and SP, whereas cells generated at E13 intersect these regions to populate the SI, with a subsequent migration of a subpopulation upwards to the SS by E17. Thus, the SS consists of two different populations of cells, with the most recently generated cells residing in the more superficial regions. Adapted from [14]. Abbrev. , strata ; , ; , . "Cells Migrated" column relates to the developmental timepoint when the cells have migrated to their final destination.<p><b>Copyright information:</b></p><p>Taken from "is requisite for maintenance of a subpopulation of superior collicular neurons and shows a diverging expression pattern to during superior collicular development"</p><p>http://www.biomedcentral.com/1471-213X/8/62</p><p>BMC Developmental Biology 2008;8():62-62.</p><p>Published online 30 May 2008</p><p>PMCID:PMC2430198.</p><p></p

Target gene expression following <i>PAX3</i> silencing.

<p>Remaining expression levels (%) of PAX3 downstream target genes in melanocytes (NHEM-n and NHEM-a (I)) and melanoma cells (WM115 and M14) assessed two day post-transfection with <i>PAX3</i> siRNA. Cells were treated with 10 μM siPAX3#1 (s224172, Ambion) alone, with consistent results observed across several independent experiments. Expression levels of downstream target genes were normalised to 18S (ΔCt) and calculated relative to the negative control siRNA (ΔΔCt). Each silencing experiment was performed with a biological duplicate.</p

Is requisite for maintenance of a subpopulation of superior collicular neurons and shows a diverging expression pattern to during superior collicular development-5

Rol indicating expression in astrocytes of the myelencephalon. GFAP+ processes extend from cells located at the pial surface, however the dorsal half of the superior colliculus in mice, like that of wildtype, is not populated by GFAP+ cells. Therefore, cell fate switching and/or transdifferentiation towards the astrocytic lineage does not account for the reduction in Pax7cells dorsally. Immunohistochemical detection of Pax6 (e, f, [inset from e]) and Engrailed (En-1) (g, h [inset from g]) was utilised to examine mesencephalic boundary formation, which appear morphologically unaffected in mutant mice. Abbrev. , cerebral cortex; , interpeduncular fossa;, mesencephalon; , pretectum; , rhombencephalic isthmus. Scale bar: a-d,f,h 100 μm; e,g 500 μm.<p><b>Copyright information:</b></p><p>Taken from "is requisite for maintenance of a subpopulation of superior collicular neurons and shows a diverging expression pattern to during superior collicular development"</p><p>http://www.biomedcentral.com/1471-213X/8/62</p><p>BMC Developmental Biology 2008;8():62-62.</p><p>Published online 30 May 2008</p><p>PMCID:PMC2430198.</p><p></p

Is requisite for maintenance of a subpopulation of superior collicular neurons and shows a diverging expression pattern to during superior collicular development-2

L) and unique (ventral [E11]/dorsal [E13]) expression patterns (a). We propose that cells generated at E13 show reduced capacity for long term maintenance in mutant mice (b), generating a phenotype whereby a superficial region is absent of Pax7cells, and the region immediately ventral to this exhibits a reduction in the number of Pax7cells (refer Fig 2e). Abbrev. , cerebral cortex; , inferior colliculus.<p><b>Copyright information:</b></p><p>Taken from "is requisite for maintenance of a subpopulation of superior collicular neurons and shows a diverging expression pattern to during superior collicular development"</p><p>http://www.biomedcentral.com/1471-213X/8/62</p><p>BMC Developmental Biology 2008;8():62-62.</p><p>Published online 30 May 2008</p><p>PMCID:PMC2430198.</p><p></p