Empowering pre-adolescent second-language learners in the middle school years

The thesis explores sociolinguistic issues facing pre-adolescent English-as-second-language learners. Topics covered include literacy issues, communicative competence issues at the intermediate and advanced English language development (ELD) levels, language and power relationships that affect pre-adolescent English language learners, politeness as a sociolinguistic tool, and the benefits of students acquiring the language of cooperative learning. The implications of these topics culminate in the development of a social studies curriculum unit designed for the middle-school classroom

Impacts of sea-level rise-induced erosion on the Catalan coast

The final publication is available at Springer via http://dx.doi.org/10.1007/s10113-016-1052-xThe Catalan coast as most of the developed Mediterranean coastal zone is characterized by the coincidence of stresses and pressures on the natural system with a high exposure and low adaptive capacity. Due to this, climate change-induced effects will increase natural hazards and aggravate their associated impacts and, in consequence, it is necessary to assess their effects for proper long-term management. In this work, we assess the impact of sea-level rise (SLR)-induced shoreline retreat on the Catalan coast for three scenarios ranging from 0.53 to 1.75 m by the year 2100. Implications are analysed in terms of affectation of two main functions provided by beaches, i.e. recreation and protection. Obtained results show that CC will be a serious threat to analysed functions since the expected enhanced shoreline retreat will severely decrease the recreational carrying capacity and the capacity of protection in the near future under tested scenarios. The actual level of development along the coastal zone reduces the natural resilient capacity of beaches to SLR in such a way that the lack of accommodation space can be identified as a main factor for the estimated impacts.Peer ReviewedPostprint (author's final draft

A method for continuous monitoring of the Ground Reaction Force during daily activity

Theoretical models and experimental studies of bone remodeling have identified peak cyclic force levels (or cyclic tissue strain energy density), number of daily loading cycles, and load (strain) rate as possible contributors to bone modeling and remodeling stimulus. To test our theoretical model and further investigate the influence of mechanical forces on bone density, we have focused on the calcaneus as a model site loaded by calcaneal surface tractions which are predominantly determined by the magnitude of the external ground reaction force (GRF)

Solución de Problemas Matriciales de “Gran Escala” sobre Procesadores Multinúcleo y GPUs

Few realize that, for large matrices, many dense matrix computations achieve nearly the same performance when the matrices are stored on disk as when they are stored in a very large main memory. Similarly, few realize that, given the right programming abstractions, coding Out-of-Core (OOC) implementations of dense linear algebra operations (where data resides on disk and has to be explicitly moved in and out of main memory) is no more difficult than programming high-performance implementations for the case where the matrix is in memory. Finally, few realize that on a contemporary eight core architecture or a platform equiped with a graphics processor (GPU) one can solve a 100, 000 × 100, 000 symmetric positive definite linear system in about one hour. Thus, for problems that used to be considered large, it is not necessary to utilize distributed-memory architectures with massive memories if one is willing to wait longer for the solution to be computed on a fast multithreaded architecture like a multi-core computer or a GPU. This paper provides evidence in support of these claimsPocos son conscientes de que, para matrices grandes, muchos cálculos matriciales obtienen casi el mismo rendimiento cuando las matrices se encuentran almacenadas en disco que cuando residen en una memoria principal muy grande. De manera parecida, pocos son conscientes de que, si se usan las abstracciones de programacón correctas, codificar algoritmos Out-of-Core (OOC) para operaciones de Álgebra matricial densa (donde los datos residen en disco y tienen que moverse explícitamente entre memoria principal y disco) no resulta más difícil que codificar algoritmos de altas prestaciones para matrices que residen en memoria principal. Finalmente, pocos son conscientes de que en una arquictura actual con 8 núcleos o un equipo con un procesador gráfico (GPU) es posible resolver un sistema lineal simétrico positivo definido de dimensión 100,000 × 100,000 aproximadamente en una hora. Así, para problemas que solían considerarse grandes, no es necesario usar arquitecturas de memoria distribuida con grandes memorias si uno está dispuesto a esperar un cierto tiempo para que la solución se obtenga en una arquitectura multihebra como un procesador multinúcleo o una GPU. Este trabajo presenta evidencias que soportan tales afirmaciones

Ultrathin film hydrogels with controlled swelling and viscoelastic properties deposited by nanosecond pulsed plasma induced-polymerization

Development of ultrathin film (utf) hydrogels for cutting-edge biomedical applications (i.e. artificial skins) is receiving increasing attention. Nonetheless, achieving accurate control on the structure and thickness of utf-hydrogels becomes extremely complex when assessed through conventional techniques. In this work, an atmospheric-pressure plasma-assisted deposition technique is reported, showing great thickness accuracy and versatility, to design utf-hydrogels with customized properties. For the first time, specific and independent control on the generation and nature of cross-links by only changing the plasma exposure frequency (fPE) during the synthesis process are reported. Thus, utf-hydrogels are successfully prepared with tuned swelling ratios and viscoelastic properties (ranging from 150 to 20 kPa). Moreover, a thickness accuracy of 9 nm is reported, permitting the accurate synthesis of utf-hydrogels below 150 nm. Exhaustive structural and topographical analyses allow elucidating the effects of the fPE on the cross-link generation mechanism, discarding any undesired effect on the thickness accuracy. To support the structural results obtained, quartz-crystal microbalance with dissipation (QCM-D) coupled with spectroscopic ellipsometry are put in the spotlight as an efficient and viable alternative for the characterization of the resulting properties of ultrathin film soft materials, including the presence of a hydrated layer at the interface.This work was supported by the Luxembourg National Research Fund (FNR) (C19/MS/13641732). J.S. was funded by the Margarita Salas Fellowship (Ministerio de Universidades de España and the European Union, NextGenerationEU).Peer ReviewedPostprint (published version

Programming matrix algorithms-by-blocks for thread-level parallelism

With the emergence of thread-level parallelism as the primary means for continued improvement of performance, the programmability issue has reemerged as an obstacle to the use of architectural advances. We argue that evolving legacy libraries for dense and banded linear algebra is not a viable solution due to constraints imposed by early design decisions. We propose a philosophy of abstraction and separation of concerns that provides a promising solution in this problem domain. The first abstraction, FLASH, allows algorithms to express computation with matrices consisting of blocks, facilitating algorithms-by-blocks. Transparent to the library implementor, operand descriptions are registered for a particular operation a priori. A runtime system, SuperMatrix, uses this information to identify data dependencies between suboperations, allowing them to be scheduled to threads out-of-order and executed in parallel. But not all classical algorithms in linear algebra lend themselves to conversion to algorithms-by-blocks. We show how our recently proposed LU factorization with incremental pivoting and closely related algorithm-by-blocks for the QR factorization, both originally designed for out-of-core computation, overcome this difficulty. Anecdotal evidence regarding the development of routines with a core functionality demonstrates how the methodology supports high productivity while experimental results suggest that high performance is abundantly achievabl

Grafted d/l-lactide to cellulose acetate by reactive melt processing: Its role as CA/PLA blend compatibilizer

AbstractCellulose acetate (CA) with a degree of substitution (DS) of 2.5 and polylactic acid (PLLA) were plasticized by melt extrusion using triacetin. Blends of resulting thermoplastic materials were then prepared and characterized by their tensile strength and differential scanning calorimetry (DSC). Thermal analysis revealed the invariability of the PLLA glass transition temperature in all blends, indicating that the compounds were immiscible. Grafted d/l lactide to CA copolymers were prepared by reactive melt processing using CA with different degree of substitution i.e. 2.1 and 2.5 and evaluated as CA/PLLA blend compatibilizer. The compatibility of the blends was investigated by scanning electron microscopy (SEM). Results showed that blend compatibility was improved evidencing the best performance of grafted copolymers with long grafted chains as blend compatibilizer of CA/PLLA blends. Finally, compatibilized blends compositions with enhanced ultimate elongation were achieved by using plasticized PLLA instead of neat PLLA