263,565 research outputs found
Proyecto de minicentral hidroeléctrica en el río de Sall
No full textAquest projecte tracta el disseny, càlcul i construcció de tots els elements necessaris per l’instal·la cio d’una minicentral hidroelèctrica en el riu de Sall situat al Pallars Sobirà (Lleida) pertanyent a la conca de l’Ebre.
Aquests elements seran principalment la pressa d’aigua, la canonada de derivació, la cambra de càrrega, la canonada forçada, l’edifici de la central i tots els equips electromecànics principals i auxiliars
Proyecto de minicentral hidroeléctrica en el río de Sall
No full textAquest projecte tracta el disseny, càlcul i construcció de tots els elements necessaris per l’instal·la cio d’una minicentral hidroelèctrica en el riu de Sall situat al Pallars Sobirà (Lleida) pertanyent a la conca de l’Ebre.
Aquests elements seran principalment la pressa d’aigua, la canonada de derivació, la cambra de càrrega, la canonada forçada, l’edifici de la central i tots els equips electromecànics principals i auxiliars
Proyecto de minicentral hidroeléctrica en el río de Sall
No full textAquest projecte tracta el disseny, càlcul i construcció de tots els elements necessaris per l’instal·la cio d’una minicentral hidroelèctrica en el riu de Sall situat al Pallars Sobirà (Lleida) pertanyent a la conca de l’Ebre.
Aquests elements seran principalment la pressa d’aigua, la canonada de derivació, la cambra de càrrega, la canonada forçada, l’edifici de la central i tots els equips electromecànics principals i auxiliars
Assessment of i<i>n vitro</i> spermatogenesis initiation after immunodetection of Sall-4, c-kit and Stra-8 proteins in CD-1 prepubertal mice testes (6.5 <i>dpp</i>) at D4 and Sall-4 immunodetection at D16 and D30 of culture, in the absence or presence of RE.
No full text<p>(<b>A</b>) Immunohistochemical detection of Sall-4, c-kit and Stra-8 on seminiferous tubule sections of prepubertal mice testes at D4 of culture in the absence (<b>A1–A4–A7</b>) or presence (<b>A2–A5–A8</b>) of RE and their corresponding <i>in vivo</i> ages (10.5 <i>dpp</i>) (<b>A3–A6–A9</b>). Brown staining was considered as a positive immunodetection of Sall-4, c-kit and Stra-8 in seminiferous tubule sections counterstained with haematoxylin. Negative control is shown on the right of each positive immunostaining. Photomicrographs were captured at a × 1000 magnification and the scale bars represent 40 μm. (<b>B</b>) Effect of RE on Sall-4, c-kit and Stra-8 expression in seminiferous tubules of prepubertal mice testes (6.5 <i>dpp</i>) cultured for 4 days <i>in vitro</i>. (<b>B1</b>) Mean proportion of Sall-4-positive cells per seminiferous tubule section (blue column) and mean proportion of Sall-4 positive tubules (red column). (<b>B2</b>) Mean proportion of c-kit positive cells per seminiferous tubule section (blue column) and mean proportion of c-kit positive tubules (red column). (<b>B3</b>) Mean proportion of Stra-8 positive cells per seminiferous tubule section (blue column) and mean proportion of Stra-8 positive tubules (red column). Values are represented as mean ± s.e.m., n = 4. Asterisk indicates a statistically significant difference between BM and RE or between BM and <i>in vivo</i> condition (<i>p</i><0.05). (<b>C</b>) Immunohistochemical detection of Sall-4 on seminiferous tubule sections of cultured prepubertal mice testes at D16 and D30 in the absence (<b>C1–C2</b>) or presence (<b>C3–C4</b>) of RE and their corresponding <i>in vivo</i> ages (22.5 <i>dpp</i> and 36.5 <i>dpp</i>, respectively) (<b>C5–C6</b>). Brown staining was considered as a positive immunodetection of Sall-4 in seminiferous tubule sections counterstained with haematoxylin. Negative control is shown on the right of each positive immunostaining. Photomicrographs were captured at a × 1000 magnification and the scale bars represent 40 μm. (<b>D</b>) Assessment of <i>in vitro</i> maintenance of undifferentiated type A spermatogonia after immunodetection of Sall-4 at D16 and D30 of culture, in the presence or absence of RE. (<b>D1</b>) Mean proportion of Sall-4-positive cells per seminiferous tubule section (blue column) and mean proportion of Sall-4 positive tubules (red column) at D16 of culture. (<b>D2</b>) Mean proportion of Sall-4-positive cells per seminiferous tubule section (blue column) and mean proportion of Sall-4 positive tubules (red column) at D30 of culture. Values are represented as mean ± s.e.m., n = 4. Asterisk indicates a statistically significant difference between BM and RE or between BM and <i>in vivo</i> condition (<i>p</i> < 0.05). <b><i>Footnotes</i>: BM</b>: Basal Medium, <b>D</b>: day, <b><i>dpp</i></b>: days post partum, <b><i>n</i></b>: Number of mice testes used in each condition, <b>NS</b>: No statistical Significance, <b>RE</b>: Retinol, <b>s.e.m.</b>: Standard Error of Mean, <b>IgG</b>: Immunoglobulin G</p
Genetic analysis of the Sall transcription factor family in murine development
No full textSpalt (sal)-like proteins are transcription factors that are described for nematodes, shrimp, insects and multiple chordata analyzed till date.
Mutations in genes of the spalt like transcription factor family have been shown to manifest in phenotypic aberrations in several model organisms. Moreover, humans carrying mutations in spalt like genes suffer from various developmental defects.
A deeper understanding of the role of Sall genes in mammalian development will therefore be required to gain insights into general development as well as elucidate the underlying principles of Townes-Brocks Syndrome and Duane-Radial Ray Syndrome, caused by mutations in SALL1 and SALL4 respectively. Mouse is the closest system to humans that is accessible to reverse genetics. Therefore, I decided to study the effects of loss of Sall orthologous genes in Mus musculus by means of genetic manipulation.
This approach generated phenotypes with full penetrance that enables the investigation of cellular responses to SALL proteins. As a result, I have identified a novel function for Sall genes in maintenance of pluripotency within progenitor populations
Promoting learner autonomy through a self-access language learning (SALL) component of a taught English course
No full textLearner autonomy is a fundamental goal of all learning for all learners (Cotterall, 2000; Littlewood, 1999) because access to formal education is always finite but the pursuit of lifelong learning is essential in all societies, especially those that are knowledge-based where constant updating of skills is crucial. A common approach to promoting learner autonomy is through self-access language learning (SALL) and there have been attempts to integrate SALL into taught English courses in different institutions around the world, particularly in Asia e.g. Hong Kong, Japan, Thailand (see for example, Fisher, Hafner & Young, 2007; Gardner, 2007a, 2007b; Kongchan & Darasawang, 2015; Mayeda, MacKenzie & Nuspliger, 2016; Thompson & Atkinson, 2010; Toogood & Pemberton, 2002; Watson & Agawa, 2016). However, there is insufficient evidence to show whether such integration effectively promotes learner autonomy and there is an absence of guiding principles to guide such integration. In addition, there is no practical and well-established model for measuring learner autonomy but such a model is necessary for evaluating the extent to which SALL promotes learner autonomy in a taught course context.
This study aims to address these gaps in the literature by examining the extent to which the SALL component of an academic English course for science students in a Hong Kong university changes students’ perceptions of SALL and promotes learner autonomy. Using a grounded theory approach and drawing on both qualitative and quantitative data from 163 students and 7 teachers, the findings show that a large majority of the students became more positive about SALL and had a better understanding of what SALL entails as a result of attending the English course. Their learner autonomy developed to a considerable, though varying extent. The data shows that the salient factors affecting the development of students’ learner autonomy during the course include the design of the SALL component, students’ language learning motivation and attitudes towards language learning, their use of language learning strategies and their prior language learning experiences.
Another important feature of this study is the longitudinal approach adopted to examine the long-term impact of SALL on the students’ autonomous development after the completion of the English course. Through two follow-up interviews with 7 students, which were conducted nine months after the end of the course and one and a half years after the students’ graduation respectively, it was found that the SALL component had had a positive impact on the students’ further studies and on their careers as it equipped students with various independent learning skills which are transferrable to a wide variety of contexts. Examining the longitudinal autonomous development trajectories of the learners confirmed the notion that context, L2 identity, motivation and learner autonomy are strongly intertwined.
Based on the empirical data, this study i) develops a 4-level model of learner autonomy which operationalises the autonomy construct and enables researchers and practitioners to measure and describe the level of autonomy of a learner, and ii) proposes a set of guiding principles for maximising the effectiveness of the integration of SALL into taught language courses.published_or_final_versionApplied English StudiesDoctoralDoctor of Philosoph
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
SALL protein tetramerisation is essential for transcription factor function
No full textMammalian Spalt-like proteins (SALL1-4) are important for early embryonic
development and organ formation. These proteins feature a conserved N-terminal
domain that interacts with the NuRD co-repressor complex and several C2H2 zincfinger
clusters, of which zinc-finger cluster 4 (ZFC4) is required for binding to AT-rich
DNA. SALL1 and SALL4 are expressed in mouse embryonic stem cells (mESCs) and
are mutated in human congenital disorders, Townes-Brocks syndrome (TBS) and
Okihiro syndrome respectively. SALL proteins can form multimeric complexes whose
nature and biological function remain unclear. This research project aims to
understand the molecular mechanism and potential functions of SALL protein
multimerisation.
I defined a 33 amino acid glutamine-rich (Q-rich) region near the N-terminus of SALL4
that is necessary and sufficient for interaction with endogenous SALL1 and SALL4 in
mESCs. AlphaFold predicts this Q-rich region to form an alpha-helix and SEC-MALS
analysis on recombinant protein complexes detected a discrete and stable tetramer.
When modelled in mESCs, a missense mutation in the Q-rich region of SALL4 found
in an Okihiro syndrome patient abolished multimerisation and disrupted nuclear sublocalisation
to AT-rich pericentric heterochromatin. This resembles defects in DNA
binding due to pathogenic SALL4 mutations in the DNA binding domain ZFC4,
indicating a potential role for transcription factor multimerisation in efficient binding to
target genes. Genome-wide approaches including CUT&RUN and RNA-seq have
verified a loss of DNA binding in Q-rich mutants and consequent deregulation of target
genes. Taken together, these findings demonstrate that SALL4 multimerisation is
required for correct genome binding and transcription factor function.
Expanding from what was learned about the Q-rich region in SALL4, I investigated
the SALL1 Q-rich region which is very conserved. Modelling the Okihiro syndrome
mutation in SALL1 abolished multimerisation and SALL1 missing the Q-rich region
altogether did not co-localise with AT-rich pericentric heterochromatin, indicating
functional conservation. Furthermore, a potential dominant-negative effect of mutated
SALL1 that is found in Townes-Brocks syndrome patients and is linked to a more
severe phenotype was studied. This prevalent TBS mutation that leads to a loss of
the ZFCs but retains the Q-rich region was able to redistribute SALL4 away from its
binding sites at AT-rich pericentric heterochromatic foci in fixed and live mESCs.
Thus, disease-truncations might reduce the DNA binding ability of the heterocomplex
and exert a dominant-negative effect on other SALL proteins, contributing to the more
severe phenotype seen in patients with these mutations.
Taken together, these results show that SALL protein multimerisation is crucial for the
function of this transcription factor family and shed light on the molecular basis of
Townes-Brocks and Okihiro syndromes
Framebreaker
No full textA bold, nonobjective painting, Eric Sall's Framebreaker emphasizes contrasting painting techniques, some used to define flat forms with precise edges, others to pull thick paint messily across the canvas. Dominating the composition is a hulking, leaning structure with stacked bars of pure colors along its sides that contrast the central area filled with palette-knife smeared paint, richly varied in its combinations of bright and dull, dark and light, and pure and tainted hues. The central structure's top right corner reads as a black wall receding into depth against the sunset wash in the background. Mitered pink, white, purple and black bands along the painting's four sides suggest a window frame that, as the title suggests, is "broken" by the massive central element. Sall stated: "I arrive at the imagery of my paintings through a balance of making deliberate shapes and spontaneously painting gestural marks in an expressive manner. This balance of distinctive approaches to making a painting is rooted in my passion for the process of painting itself, specifically a passion for making rich fields of color, a keenness for painting straight lines, and a strong desire to 'muck' things up by pulling paint across the surface with various painting knives and brushes." Eric Sall received a BFA from the Kansas City Art Institute in 1999 and an MFA from Virginia Commonwealth University in 2006. - Karen C. Gerety Fol
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