Raising awareness of the accessibility challenges in mathematics MOOCs

MOOCs provide learning environments that make it easier for learners to study from anywhere, at their own pace and with open access to content. This has revolutionised the field of eLearning, but accessibility continues to be a problem, even more so if we include the complexity of the STEM disciplines which have their own specific characteristics. This work presents an analysis of the accessibility of several MOOC platforms which provide courses in mathematics. We attempt to visualise the main web accessibility problems and challenges that disabled learners could face in taking these types of courses, both in general and specifically in the context of the subject of mathematics

Lecciones ecológicas de la historia amazónica: impacto diferencial del uso del suelo en las estructuras y biomasas aéreas de bosques secundarios en Napo, Ecuador

Amazonian forests mitigate climate change, are being deforested and recover their structures and functions throughout secondary succession. It is necessary to understand how different land-uses alter such a recovery and why landowners decide to clear-cut some areas while letting others to fallow. That was addressed by counting and measuring all trees of at least 10 cm diameter in four one-hectare plots whose land-use histories were exhaustively reconstructed using ethnographic-historical methods. Plots A (12-15 years old), B (22-25 years old) and C (35-37 years old) were pastures and oligocultures for feeding human populations growing during a period of vigorous oil-exploration; next, food demands changed and plots were abandoned. Plot D (35-40 years old) was used for self-consumption, shifting agriculture (more than 50 planted species), afterwards used and managed for extracting resources during secondary succession. Tree diameters in plots B and C were larger compared to those found in plots A and D –which were similar. The latter suggests that fallow management in plot D kept its forest structurally young, hence, the Amazon may include forests chronologically older than the age suggested by their structures. Similar results were found for total basal area and aboveground biomass, while the high density of individuals in plot D suggests a vigorous gap regeneration. In conclusion: different land-uses are confirmed to alter further succession, and the changes of food demand and food security affect farmer`s decisions on letting forests to recover. Local development planners may take the later into account

Secreted protein acidic and rich in cysteine produced by human melanoma cells modulates polymorphonuclear leukocyte recruitment and antitumor cytotoxic capacity

The expression of secreted protein acidic and rich in cysteine (SPARC) has been associated with the malignant progression of different types of human cancer. SPARC was associated with tumor cell capacity to migrate and invade, although its precise role in tumor progression is still elusive. In the present study, we show that SPARC produced by melanoma cells modulates the antitumor activity of polymorphonuclear leukocytes (PMN). Administration to nude mice of human melanoma cells in which SPARC expression was transiently or stably knocked down by antisense RNA (SPARC-sup cells) promoted PMN recruitment and obliterated tumor growth even when SPARC-sup cells accounted for only 10% of injected malignant cells. In addition, SPARC-sup cells stimulated the in vitro migration and triggered the antimelanoma cytotoxic capacity of human PMN, an effect that was reverted in the presence of SPARC purified from melanoma cells or by reexpressing SPARC in SPARC-sup cells. Leukotrienes, interleukin 8, and growth-related oncogene, in combination with Fas ligand and interleukin 1, mediated SPARC effects. These data indicate that SPARC plays an essential role in tumor evasion from immune surveillance through the inhibition of the antitumor PMN activity.Facultad de Ciencias Veterinaria

Secreted protein acidic and rich in cysteine produced by human melanoma cells modulates polymorphonuclear leukocyte recruitment and antitumor cytotoxic capacity

The expression of secreted protein acidic and rich in cysteine (SPARC) has been associated with the malignant progression of different types of human cancer. SPARC was associated with tumor cell capacity to migrate and invade, although its precise role in tumor progression is still elusive. In the present study, we show that SPARC produced by melanoma cells modulates the antitumor activity of polymorphonuclear leukocytes (PMN). Administration to nude mice of human melanoma cells in which SPARC expression was transiently or stably knocked down by antisense RNA (SPARC-sup cells) promoted PMN recruitment and obliterated tumor growth even when SPARC-sup cells accounted for only 10% of injected malignant cells. In addition, SPARC-sup cells stimulated the in vitro migration and triggered the antimelanoma cytotoxic capacity of human PMN, an effect that was reverted in the presence of SPARC purified from melanoma cells or by reexpressing SPARC in SPARC-sup cells. Leukotrienes, interleukin 8, and growth-related oncogene, in combination with Fas ligand and interleukin 1, mediated SPARC effects. These data indicate that SPARC plays an essential role in tumor evasion from immune surveillance through the inhibition of the antitumor PMN activity.Facultad de Ciencias Veterinaria

Normal, and lognormal: two frequency distributions, and one Unified Neutral Theory for studying Tropical forests

Los inventarios de biodiversidad en sitios contrastantes obtienen datos con distribuciones normales y lognormales, útiles para cuantificar cómo el cambio climático afecta a los bosques del mundo. Sin embargo, casi todos los biólogos están familiarizados con la normal, pero menos discuten el por qué la distribución lognormal de frecuencias relativas de especies ocurre en tantas comunidades bióticas. Pretendemos incorporar a más estudiosos a dicha discusión. Tanto la normal como la lognormal tienen medias y valores extremos. Ello es consistente con el teorema del límite central; válido cuando los datos de un muestreo provienen de procesos aleatorios y el muestreo ha sido estocástico y representativo. Según la Teoría Neutral Unificada de la Biodiversidad y la Biogeografía de Steve Hubbell, basta considerar que la natalidad, mortalidad, migraciones y especiación en una comunidad, y desde la metacomunidad circundante, ocurren al azar y simétricamente entre especies, para explicar que las frecuencias relativas de la comunidad sigan una distribución lognormal. Ello es consistente con la Biogeografía de Islas, y se puede aplicar –por tanto a la articulación de abundancias relativas de especies arbóreas en bosques que se regeneran por sucesión secundaria, donde el sitio talado constituye una isla que luego es colonizada. En el sofisticado siglo XXI, conocimientos numéricos tan simples, como la normal y la lognormal, siguen siendo necesarios para mover las fronteras de la ciencia afrontando temas permanentes: por qué en tantos lugares hay especies más abundantes que otras, y cómo se puede contrarrestar la pérdida de las especies en dificultad.Biodiversity surveys among contrasting sites get normal, and lognormal distributed data used for quantifying how Climate Change affects forests around the world. Yet most biologists are familiarized with the normal distribution, while few discuss why the lognormal distribution of relative frequencies of species is so common in many communities of living beings. We aim to add more researchers into such a discussion. Both normal and lognormal have mean and extreme values –which is consistent with the Central Limit Theorem. Such a theorem is valid when the data come from random processes, and when the sampling excercise of collecting the data has been stocastic and representative. According to Steve Hubbell’s Unified Neutral Theory of Biodiversity and Biogeography, random birth, death, migration and speciation in a community –and from the surrounding metacomunity are enough for generating lognormal distributions of relative frequencies of co-existing species. That is consistent with Island Biogography, and is applicable to the assembly of relative abundances of tree species during secondary succession, where the clear-cut site is an island further colonized by tree species. Deep into the sophisticated 21st century, simple numerical knowledge like the normal and lognormal are still needed for moving the borders of science by facing permanent subjects: why in so many places some species are more abundant than others, and how to tackle the loss of endangered species

Considering and interpreting leisure: pastimes, entertainments, hobbies and addictions in the Barcelona of 1900

Coordinació: Teresa-M. SalaIn the throes of modernization, the Barcelona of 1900 was buzzing with energy and an unprecedented culture of leisure emerged. The city’s residents made full use of their free time, forging relationships with one another through a highly varied range of initiatives and activities, taking advantage of existing opportunities and creating new ones. In addition to the traditional celebration of civic festivals, popular meals and various types of processions, innovative new forms of cultural consumption sprang up to satisfy all tastes and budgets. Numerous cinemas opened, the first amusement parks threw open their gates and new theatres raised their curtains. Thanks to these developments, the vicinity around the avenue Paral·lel became the epicentre of Barcelona nightlife. This book offers a panoply of images of the diversions, entertainments and hobbies of that fascinating era of contrasts, the turn-of-the-century Barcelona of Modernisme

¿CUÁN IMPORTANTES SON LOS BOSQUES SECOS PARA LAS URBANIZACIONES? EL CASO DE DAULE, ECUADOR

Global change and direct sun near the ecuador increase the temperature of cities whereas forests regulate such temperature. We therefore assessed the structure and above ground biomass of two forest remnants nearby a newly built urbanization in Daule, Ecuador (Daule 1-2). We made n=5 transects (25 m × 4 m) covering 0.05 ha/site, then measured all trees ≥2.5 cm dbh (1.3 m above ground level) and compared with other forests studied by Alwyn Gentry. Daule-1 and Daule-2 had 39 and 35 individuals, respectively whereas Gentry found 159 and 216 individuals at Capeira and Esmeraldas. The densities for our n=5 transects (average ± standard error) were smaller for (Daule-1=780±37.42 ind/ha) and (Daule-2=740±40.00 ind/ha) while Capeira and Esmeraldas (n=10 transects for each site) which had (2270±211.37 ind/ha) and (3540±265.50 ind/ha), respectively (ANOVA, P<0.001). The carbon captured was Daule-1=131.6 Mg/ha, Daule-2=111.7 Mg/ha, Daule-1+Daule-2=243.3 Mg/ha likewise Capeira 210.6 Mg / ha and Esmeraldas 181.5 Mg / ha. Such results suggest that forest remnants play an important role for people’s life quality by capturing carbon dioxide and producing oxygen; role they would play better if the forests would have more extensive.El calentamiento global y el sol directo cerca del ecuador aumentan la temperatura en las ciudades, mientras que los bosques son los encargados de regular dicha temperatura. Evaluamos la estructura y biomasa aérea de dos remanentes de bosques cerca de una urbanización en construcción en Daule, Ecuador (Daule 1-2). Se tomaron n=5 transectos (25 m x 4 m) cubriendo 0.05 ha/sitio, medimos todos los árboles ≥2,5 cm dap (1.3 m sobre el nivel del suelo) y comparamos con otros bosques estudiados por Alwyn Gentry. Daule-1 y Daule-2 tenían 39 y 35 individuos, respectivamente, mientras que Gentry encontró 159 y 216 individuos en Capeira y Esmeraldas. La densidad en los n=5 transectos (promedio ± error estándar) fueron menores para (Daule-1=780±37.42 ind/ha) y (Daule-2=740±40.00 ind/ha) en tanto que Capeira y Esmeraldas (n=10 transectos para cada sitio) tuvieron (2270±211.37 ind/ha) y (3540±265.50 ind/ha), respectivamente (ANOVA, P<0.001). El carbono capturado fueDaule-1=131.6 Mg/ha, Daule-2=111.7 Mg/ha, Daule-1+Daule-2=243.3Mg/ha así mismo Capeira 210.6 Mg/ha y Esmeraldas 181.5 Mg/ha. Tales resultados sugieren que los remanentes de bosques juegan un papel importante para la calidad de vida de las personas al capturar dióxido de carbono y producir oxígeno; papel que jugarían mejor si los bosques fueran más extensos. &nbsp

Non-invasive Diagnostic of Helicobacter pylori in Stools by Nested-qPCR

The aim of this study was to develop a non-invasive diagnostic test for the detection of Helicobacter pylori in stool samples from digestive symptomatic patients, using a new protocol of nested-qPCR. A total of 143 patients were invited to participate in the study. A gastric biopsy of each patient was collected for Rapid Urease Testing (RUT) and histology by Giemsa stain. A fecal sample for nested-qPCR analysis was also obtained. DNA was extracted from the fecal samples, and conventional PCR followed by qPCR of the ureC gene of H. pylori was carried out. We evaluated the presence of H. pylori, in 103 females and 40 males, mean (± SD) age of 56.5 ± 14.18. The sensitivity of RUT to detect the infection was 67.0% (95% C.I.: 57.2 – 75.8) and specificity was 92.3% (95% C.I.: 76.5 – 99.1). Histology by Giemsa stain, commonly used as a reference for H. pylori detection, showed a sensitivity of 98.6% (95% C.I.: 92.5 – 100.0) and a specificity of 89.7% (95% C.I.: 72.7 – 97.8). In contrast, detection of H. pylori infection in stools by nested-qPCR showed a sensitivity of 100% (95% C.I.: 94.9 – 100.0) and a specificity of 83.9% (95% C.I.: 66.3 – 94.6). Our test, based in nested-qPCR is a better diagnostic alternative than conventional RUT, and is similar to histology by Giemsa stain in the detection of H. pylori, by which the test could be used for non-invasive diagnosis in clinical practice