Transposing MISA Learning Scenarios into IMS Units of Learning

Commentary on: Chapter 17: Applying Learning Design to Supported Open Learning. (McAndrew & Weller, 2005) Abstract: This paper reports an exploratory study investigating the transposition process of a course called the Black Box into a Unit of Learning (UoL), characterized by its collaborative and multi-actor distance learning scenario. It was graphically represented by using the MOT software used in the MISA Instructional Engineering Method. To transpose this scenario into an IMSLD UoL, the iterative nature of this study helped develop the MOT+LD editor and an IMSLD Graphical Representation Code (GRC) now embedded in the editor. The study showed that the MISA method and Level A of the IMSLD Specification share several conceptual elements and representations that accentuate their complementarity in a coherent and clear manner. This finding is very encouraging to extend the analysis of levels B and C of the specification and adapt the MISA method to ease the construction of fully interoperable IMSLD UoL. Editors: Colin Tattersall and Rob Koper

Childhood Sexual Abuse, Intellectual Disability, and Subsequent Physical and Mental Health Disorders: A Matched Cohort Study

This study assesses whether children with intellectual disabilities (ID) are more at risk of sexual abuse and whether they have similar consultation rates for physical and mental health disorders than children without ID. The matched-cohort design study uses administrative databases of children who had a sexual abuse report corroborated by a child protection agency and a matched group from the general population. Children with ID were 3.5 times more likely to have a corroborated sexual abuse report when compared to their peers without ID and a higher postabuse number of medical consultations for physical and mental health disorders. Children with ID are more at risk of sexual abuse and physical and mental health disorders and may also be more vulnerable to the effects of abuse

Delivery of Learning Design: the Explor@ System’s Case

The IMS Learning Design Specification (IMS-LD) presents new challenges to learning delivery systems. To comply with this specifi-cation, delivery platforms must understand different learning strategies and course structures, must manage multi-actor environments, must allow for standard learning objects integration, must deal with condi-tions and rules to be validated on runtime and must support notifica-tions. In this chapter, we take a look at these requirements from the view-point of an open delivery system, Explor@-2. Explor@-2 is the result of a research stream that started a decade ago at Télé-université’s LICEF research center. Explor@ has focused, right from the begin-ning, on a resource (or learning object) management orientation, mak-ing it possible to assemble a set of educational support tools, docu-ments and services to be shared across all programs, courses or activi-ties delivered by an organization. The chapter presents Explor@-2’s basic learning design information model and analyses how Explor@-2 can deal with IMS-LD compliant courses – how it can deliver units of learning modelled either with the IMS-LD level A specification or with the IMS-LD level B or C specifications. The chapter ends with some conclusions on future research and development to be done in order to build a fully IMS-LD compliant delivery system as well as on some promising directions for developing powerful and adaptive dis-tance learning environments

The Incahuasi resurgent caldera (Ayacucho Province, Peru), a site of high-magnitude explosive eruptions in Miocene times

In this work we document a large Miocene resurgent caldera located south of the Ayacucho province (area between the cities of Coracora, Jaqui and Pauza), where geothermal-epithermal economic potentials might exist, and this is the first resurgent caldera ever reported in the Peruvian territory. Geological studies combined with geochronological and remote sensing analyses allowed us to recognize a flat and depressed area at Laguna de Parinacochas (3278 m asl), a 10 x 8 km-large salar (salt lake) encircled by hills and elevations peaking at about 3600 m asl. On the north-western side of the salt lake, the crest consists of weathered whitish-yellowish ignimbrite deposits, with local sliding structures towards the lake. The eastern side of Laguna de Parinacochas exhibits a series of normal faults at the north-western base of Sara Sara volcano, with subsidence towards Laguna de Parinacochas depression. In our interpretation these morpho-structural features around the lake are expressions of the southern part of a wider caldera complex. Siliciclastic and finely stratified lacustrine sedimentary sequences, in which major ca 9 Ma-old Plinian tephra fall deposits are interbedded, are exposed in the area and support the existence of an intra-caldera paleo-lake. Altered zones with kaolin and silicified patches, fluid circulations, hot springs, bubbling, and sulfur smells are reported within and on the edge of a vast 25 x 35 km-wide structure that we call the Incahuasi caldera system. The caldera is likely polygenic and the last collapse event occurred during the eruption of the approx. 300 cubic km, 9 Ma-old rhyolitic Caraveli ignimbrite, which flowed 100 km west to the Pacific seashore. In addition, a combination of structural elements reveals that the 16 x 18 km-wide and about 1 km-high volcanic complex located north of Laguna de Parinacochas has been upheaved partly by tectonic processes, and also by volcanic resurgence, as evidenced by a typical apical graben associated with intense alteration features. The lavas that cap the resurgent dome are dated at ca 6.6 Ma and seemingly mark the end of the activity at the Incahuasi caldera system. Younger volcanism in the area includes formation of the Sara Sara edifice, a quaternary volcano that grew near, but outside of the Incahuasi caldera complex. Sara Sara erupted essentially rhyo-dacitic products, notably during repeated powerful Plinian events of Pleistocene age. This suggests the presence of a potentially still active silicic reservoir at some depth beneath the area

In vitro irradiation of basement membrane enhances the invasiveness of breast cancer cells

Following removal of the primary breast tumour by conservative surgery, patients may still have additional malignant foci scattered throughout the breast. Radiation treatments are not designed to eliminate all these residual cancer cells. Rather, the radiation dose is calculated to optimise long-term results with minimal complications. In a tumour, cancer cells are surrounded by a basement membrane, which plays an important role in the regulation of gene expression. Using an invasion chamber, we have shown that irradiation before cell plating of a reconstituted basement membrane (Matrigel; Becton Dickinson, Bedford, MA, USA) increased the invasiveness of the breast cancer cells MDA-MB-231. This radiation enhancement of invasion was associated with the upregulation of the pro-invasive gene matrix metalloproteinase (MMP)-2. The expression of membrane type 1 matrix metalloproteinase (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP), which are required to activate the MMP-2, were also increased. Confirming the role of MMP-2 and MT1-MMP, radiation enhancement of cancer cell invasion was prevented by an MMP-2 inhibitor and an anti-MT1-MMP antibody. This study also demonstrated that radiation can potentially enhance the invasion ability by inducing the release of pro-invasive factors stored in the Matrigel. Conversely, no enhancement of invasiveness was observed with the low metastatic cell line MCF-7. This lack of invasiveness correlated with the absence of the MMP-2 activator MT1-MMP in the MCF-7 cells. Radiotherapy is an efficient modality to treat breast cancer which could be further improved by inhibiting the pro-invasive gene upregulated by radiation

Does Father Know Best? A Formal Model of the Paternal Influence on Childhood Social Anxiety

We explore paternal social anxiety as a specific risk factor for childhood social anxiety in a rational optimization model. In the course of human evolution, fathers specialized in external protection (e.g., confronting the external world) while mothers specialized in internal protection (e.g., providing comfort and food). Thus, children may instinctively be more influenced by the information signaled by paternal versus maternal behavior with respect to potential external threats. As a result, if fathers exhibit social anxiety, children interpret it as a strong negative signal about the external social world and rationally adjust their beliefs, thus becoming stressed. Under the assumption that paternal signals on social threats are more influential, a rational cognitive inference leads children of socially anxious fathers to develop social anxiety, unlike children of socially anxious mothers. We show in the model that mothers cannot easily compensate for anxious paternal behavior, but choose to increase maternal care to maintain the child’s wellbeing. We discuss research directions to test the proposed model as well as implications for the prevention and treatment of child social anxiety

Non-monotonic changes in clonogenic cell survival induced by disulphonated aluminum phthalocyanine photodynamic treatment in a human glioma cell line

<p>Abstract</p> <p>Background</p> <p>Photodynamic therapy (PDT) involves excitation of sensitizer molecules by visible light in the presence of molecular oxygen, thereby generating reactive oxygen species (ROS) through electron/energy transfer processes. The ROS, thus produced can cause damage to both the structure and the function of the cellular constituents resulting in cell death. Our preliminary investigations of dose-response relationships in a human glioma cell line (BMG-1) showed that disulphonated aluminum phthalocyanine (AlPcS₂) photodynamically induced loss of cell survival in a concentration dependent manner up to 1 μM, further increases in AlPcS₂concentration (>1 μM) were, however, observed to decrease the photodynamic toxicity. Considering the fact that for most photosensitizers only monotonic dose-response (survival) relationships have been reported, this result was unexpected. The present studies were, therefore, undertaken to further investigate the concentration dependent photodynamic effects of AlPcS₂.</p> <p>Methods</p> <p>Concentration-dependent cellular uptake, sub-cellular localization, proliferation and photodynamic effects of AlPcS₂were investigated in BMG-1 cells by absorbance and fluorescence measurements, image analysis, cell counting and colony forming assays, flow cytometry and micronuclei formation respectively.</p> <p>Results</p> <p>The cellular uptake as a function of extra-cellular AlPcS₂concentrations was observed to be biphasic. AlPcS₂was distributed throughout the cytoplasm with intense fluorescence in the perinuclear regions at a concentration of 1 μM, while a weak diffuse fluorescence was observed at higher concentrations. A concentration-dependent decrease in cell proliferation with accumulation of cells in G₂+M phase was observed after PDT. The response of clonogenic survival after AlPcS₂-PDT was non-monotonic with respect to AlPcS₂concentration.</p> <p>Conclusions</p> <p>Based on the results we conclude that concentration-dependent changes in physico-chemical properties of sensitizer such as aggregation may influence intracellular transport and localization of photosensitizer. Consequent modifications in the photodynamic induction of lesions and their repair leading to different modes of cell death may contribute to the observed non-linear effects.</p

The Effect of the CO32- to Ca2+ Ion activity ratio on calcite precipitation kinetics and Sr2+ partitioning

<p>Abstract</p> <p>Background</p> <p>A proposed strategy for immobilizing trace metals in the subsurface is to stimulate calcium carbonate precipitation and incorporate contaminants by co-precipitation. Such an approach will require injecting chemical amendments into the subsurface to generate supersaturated conditions that promote mineral precipitation. However, the formation of reactant mixing zones will create gradients in both the saturation state and ion activity ratios (i.e., <inline-formula><m:math name="1467-4866-13-1-i1" xmlns:m="http://www.w3.org/1998/Math/MathML"><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:msub><m:mrow><m:mi>O</m:mi></m:mrow><m:mrow><m:mn>3</m:mn></m:mrow></m:msub></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msup></m:mrow></m:msub><m:mo class="MathClass-bin">/</m:mo><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">+</m:mo></m:mrow></m:msup></m:mrow></m:msub></m:math></inline-formula>). To better understand the effect of ion activity ratios on CaCO₃precipitation kinetics and Sr²⁺co-precipitation, experiments were conducted under constant composition conditions where the supersaturation state (Ω) for calcite was held constant at 9.4, but the ion activity ratio <inline-formula><m:math name="1467-4866-13-1-i2" xmlns:m="http://www.w3.org/1998/Math/MathML"><m:mrow><m:mo class="MathClass-open">(</m:mo><m:mrow><m:mi>r</m:mi><m:mo class="MathClass-rel">=</m:mo><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:msub><m:mrow><m:mi>O</m:mi></m:mrow><m:mrow><m:mn>3</m:mn></m:mrow></m:msub></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msup></m:mrow></m:msub><m:mo class="MathClass-bin">/</m:mo><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">+</m:mo></m:mrow></m:msup></m:mrow></m:msub></m:mrow><m:mo class="MathClass-close">)</m:mo></m:mrow></m:math></inline-formula> was varied between 0.0032 and 4.15.</p> <p>Results</p> <p>Calcite was the only phase observed, by XRD, at the end of the experiments. Precipitation rates increased from 41.3 ± 3.4 μmol m^-2min^-1at <it>r = </it>0.0315 to a maximum rate of 74.5 ± 4.8 μmol m^-2min^-1at <it>r = </it>0.306 followed by a decrease to 46.3 ± 9.6 μmol m^-2min^-1at <it>r </it>= 1.822. The trend was simulated using a simple mass transfer model for solute uptake at the calcite surface. However, precipitation rates at fixed saturation states also evolved with time. Precipitation rates accelerated for low <it>r </it>values but slowed for high <it>r </it>values. These trends may be related to changes in effective reactive surface area. The <inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" name="1467-4866-13-1-i1"><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:msub><m:mrow><m:mi>O</m:mi></m:mrow><m:mrow><m:mn>3</m:mn></m:mrow></m:msub></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msup></m:mrow></m:msub><m:mo class="MathClass-bin">/</m:mo><m:msub><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mi>C</m:mi><m:msup><m:mrow><m:mi>a</m:mi></m:mrow><m:mrow><m:mn>2</m:mn><m:mo class="MathClass-bin">+</m:mo></m:mrow></m:msup></m:mrow></m:msub></m:math></inline-formula> ratios did not affect the distribution coefficient for Sr in calcite (D^P_Sr²⁺), apart from the indirect effect associated with the established positive correlation between D^P_Sr²⁺and calcite precipitation rate.</p> <p>Conclusion</p> <p>At a constant supersaturation state (Ω = 9.4), varying the ion activity ratio affects the calcite precipitation rate. This behavior is not predicted by affinity-based rate models. Furthermore, at the highest ion ratio tested, no precipitation was observed, while at the lowest ion ratio precipitation occurred immediately and valid rate measurements could not be made. The maximum measured precipitation rate was 2-fold greater than the minima, and occurred at a carbonate to calcium ion activity ratio of 0.306. These findings have implications for predicting the progress and cost of remediation operations involving enhanced calcite precipitation where mineral precipitation rates, and the spatial/temporal distribution of those rates, can have significant impacts on the mobility of contaminants.</p