Bayesian Analysis of Simple Step-stress Model under Weibull Lifetimes

Department of Statistics, Cochin University of Science & Technology, Part of this work has been supported by grants from DST and CSIR, Government of India. 2Department of Mathematics and Statistics, IIT Kanpur

VUV-Laserablation von Spinnenseide

Spinnenseide gehört zu den stabilsten bekannten Polymerverbindungen. Spinnfäden können bis auf das Dreifache ihrer ursprünglichen Länge gedehnt werden, bevor sie reißen, und dabei mit rund 160 MJ/m³ mehr als dreimal soviel Energie absorbieren wie die stärkste synthetisch hergestellte Faser Kevlar (50 MJ/m³). Dabei weisen Spinnfäden mit 2 bis 5 Mikrometer nur ein Zehntel des Durchmessers eines menschlichen Haares auf. Das präzise, berührungslose Bearbeiten von Spinnenseide ist für verschiedene technische Anwendungen interessant, insbesondere wenn dabei ihre außergewöhnlichen Eigenschaften erhalten bleiben. Könnten die von Natur aus dünnen Seidenfäden gezielt in ihrem Durchmesser verringert werden, so wären sie unter anderem in der Mikroelektronik einzusetzen. Hier könnten sie als Trägermaterial für eine dünne, elektrisch leitfähige Schicht fungieren. Man erhielte Nanodrähte, die auch in mechanisch besonders belasteten Mikroelektronikbauteilen (MEMS) Verwendung finden könnten. In dieser Arbeit wird die Verwendung der laserinduzierten Ablation zur gezielten Bearbeitung von Haltefäden der Schwarzen Witwe (Latrodectus hesperus) beschrieben. Eingesetzt wurde ein VUV-Excimerlaser vom Typ LPF 205 (Lambda-Physik, Göttingen) mit einer Wellenlänge von 157 nm und einer Pulsdauer von 18 ns. Eine berührungslose Laserbearbeitung bei 157 nm erlaubt einen effizienten und präzisen Abtrag von Material durch Ablation aufgrund der geringen optischen Eindringtiefe von unter 100 nm oberhalb einer Schwellenfluenz (Energie/Fläche) von Φth=29 mJ/cm², ohne dabei das umgebende Material thermisch zu beeinträchtigen. Parallel zur Ablation setzt allerdings eine wellenförmige Oberflächenstrukturierung auf der Faseroberfläche ein, wodurch die mechanische Belastbarkeit der Faser entscheidend geschwächt wird. Die Ursache hierfür liegt im Abbau materialbedingter Spannungsfelder („stress release“) innerhalb einer durch das Laserlicht induzierten dünnen Schmelzschicht. Im Rahmen dieser Arbeit ist es nun gelungen, diese Strukturen durch einen anschließenden Glättungsprozeß zu entfernen. Dabei wird auf der bestrahlten Oberfläche mittels Laserlichts eine glatte Ablation erzielt. Mit feinerer Abstufung dieser Prozeßschritte konnte der Durchmesser des verwendeten Spinnenseidefadens zum Teil um 70 Prozent bis auf ca. 750 nm verringert werden. Durch Zugfestigkeitsexperimente wurde belegt, daß die mechanischen Eigenschaften der so bearbeiteten Spinnenseide weitgehend erhalten bleiben. Die im Rahmen dieser Arbeit angewandte Methode erlaubt somit eine präzise Laserablation von Spinnenseide und ähnlichen hochabsorbierenden Materialien, ohne deren Kernsubstanz in ihrer Beschaffenheit zu verändern.

Studies of cap-independent mRNA translation in Drosophila melanogaster

Control of protein synthesis is a key step in the regulation of gene expression during apoptosis and the heat shock response. Under such conditions, cap-dependent translation is impaired and Internal Ribosome Entry Site (IRES)-dependent translation plays a major role in mammalian cells. Although the role of IRES-dependent translation during apoptosis has been mainly studied in mammals, its role in the translation of Drosophila apoptotic genes has not been yet studied. The observation that the Drosophila mutant embryos for the cap-binding protein, the eukaryotic initiation factor eIF4E, exhibits increased apoptosis in correlation with up-regulated proapoptotic gene reaper (rpr) transcription constitutes the first evidence for the existence of a cap-independent mechanism for the translation of Drosophila proapoptotic genes. The mechanism of translation of rpr and other proapoptotic genes was investigated in this work. We found that the 5 UTR of rpr mRNA drives translation in an IRES-dependent manner. It promotes the translation of reporter RNAs in vitro either in the absence of cap, in the presence of cap competitors, or in extracts derived from heat shocked and eIF4E mutant embryos and in vivo in cells transfected with reporters bearing a non functional cap structure, indicating that cap recognition is not required in rpr mRNA for translation. We also show that rpr mRNA 5 UTR exhibits a high degree of similarity with that of Drosophila heat shock protein 70 mRNA (hsp70), an antagonist of apoptosis, and that both are able to conduct IRES-mediated translation. The proapoptotic genes head involution defective (hid) and grim, but not sickle, also display IRES activity. Studies of mRNA association to polysomes in embryos indicate that both rpr, hsp70, hid and grim endogenous mRNAs are recruited to polysomes in embryos in which apoptosis or thermal stress was induced. We conclude that hsp70 and, on the other hand, rpr, hid and grim which are antagonizing factors during apoptosis, use a similar mechanism for protein synthesis. The outcome for the cell would thus depend on which protein is translated under a given stress condition. Factors involved in the differential translation driven by these IRES could play an important role. For this purpose, we undertook the identification of the ribonucleoprotein (RNP) complexes assembled onto the 5 UTR of rpr mRNA. We established a tobramycin-affinity-selection protocol that allows the purification of specific RNP that can be further analyzed by mass spectrometry. Several RNA binding proteins were identified as part of the rpr 5 UTR RNP complex, some of which have been related to IRES activity. The involvement of one of them, the La antigen, in the translation of rpr mRNA, was established by RNA-crosslinking experiments using recombinant protein and rpr 5 UTR and by the analysis of the translation efficiency of reporter mRNAs in Drosophila cells after knock down of the endogenous La by RNAi experiments. Several uncharacterized proteins were also identified, suggesting that they might play a role during translation, during the assembly of the translational machinery or in the priming of the mRNA before ribosome recognition. Our data provide evidence for the involvement of La antigen in the translation of rpr mRNA and set a protocol for purification of tagged-RNA-protein complexes from cytoplasmic extracts. To further understand the mechanisms of translation initiation in Drosophila, we analyzed the role of eIF4B on cap-dependent and cap-independent translation. We showed that eIF4B is mostly involved in cap-, but not IRES-dependent translation as it happens in mammals.

Development of directly modulated high speed telecommunication lasers based on surface defined feedback gratings

High-speed semiconductor lasers are an integral part in the implemen- tation of high-bit-rate optical communications systems. They are com- pact, rugged, reliable, long-lived, and relatively inexpensive sources of coherent light. Due to the very low attenuation window that exists in the silica based optical fiber at 1.55 μm and the zero dispersion point at 1.3 μm, they have become the mainstay of optical fiber com- munication systems. For the fabrication of lasers with gratings such as, distributed bragg reflector or distributed feedback lasers, etching is the most critical step. Etching defines the lateral dimmensions of the structure which determines the performance of optoelectronic devices. In this thesis studies and experiments were carried out about the exist- ing etching processes for InP and a novel dry etching process was de- veloped. The newly developed process was based on Cl2/CH4/H2/Ar chemistry and resulted in very smooth surfaces and vertical side walls. With this process the grating definition was significantly improved as compared to other technological developments in the respective field. A surface defined grating definition approach is used in this thesis work which does not require any re-growth steps and makes the whole fabrication process simpler and cost effective. Moreover, this grating fabrication process is fully compatible with nano-imprint lithography and can be used for high throughput low-cost manufacturing. With usual etching techniques reported before it is not possible to etch very deep because of aspect ratio dependent etching phenomenon where with increasing etch depth the etch rate slows down resulting in non-vertical side walls and footing effects. Although with our de- veloped process quite vertical side walls were achieved but footing was still a problem. To overcome the challenges related to grating defini- tion and deep etching, a completely new three step gas chopping dry etching process was developed. This was the very first time that a time multiplexed etching process for an InP based material system was demonstrated. The developed gas chopping process showed extra ordinary results including high mask selectivity of 15, moderate etch- ing rate, very vertical side walls and a record high aspect ratio of 41. Both the developed etching processes are completely compatible with nano imprint lithography and can be used for low-cost high-throughput fabrication. A large number of broad area laser, ridge waveguide laser, distributed feedback laser, distributed bragg reflector laser and coupled cavity in- jection grating lasers were fabricated using the developed one step etch- ing process. Very extensive characterization was done to optimize all the important design and fabrication parameters. The devices devel- oped have shown excellent performance with a very high side mode suppression ratio of more than 52 dB, an output power of 17 mW per facet, high efficiency of 0.15 W/A, stable operation over temperature and injected currents and a threshold current as low as 30 mA for almost 1 mm long device. A record high modulation bandwidth of 15 GHz with electron-photon resonance and open eye diagrams for 10 Gbps data transmission were also shown.

Capturing Emergent Semantics from Social Annotation Systems

The ongoing growth of the World Wide Web, catalyzed by the increasing possibility of ubiquitous access via a variety of devices, continues to strengthen its role as our prevalent information and commmunication medium. However, although tools like search engines facilitate retrieval, the task of finally making sense of Web content is still often left to human interpretation. The vision of supporting both humans and machines in such knowledge-based activities led to the development of different systems which allow to structure Web resources by metadata annotations. Interestingly, two major approaches which gained a considerable amount of attention are addressing the problem from nearly opposite directions: On the one hand, the idea of the Semantic Web suggests to formalize the knowledge within a particular domain by means of the "top-down" approach of defining ontologies. On the other hand, Social Annotation Systems as part of the so-called Web 2.0 movement implement a "bottom-up" style of categorization using arbitrary keywords. Experience as well as research in the characteristics of both systems has shown that their strengths and weaknesses seem to be inverse: While Social Annotation suffers from problems like, e. g., ambiguity or lack or precision, ontologies were especially designed to eliminate those. On the contrary, the latter suffer from a knowledge acquisition bottleneck, which is successfully overcome by the large user populations of Social Annotation Systems. Instead of being regarded as competing paradigms, the obvious potential synergies from a combination of both motivated approaches to "bridge the gap" between them. These were fostered by the evidence of emergent semantics, i. e., the self-organized evolution of implicit conceptual structures, within Social Annotation data. While several techniques to exploit the emergent patterns were proposed, a systematic analysis - especially regarding paradigms from the field of ontology learning - is still largely missing. This also includes a deeper understanding of the circumstances which affect the evolution processes. This work aims to address this gap by providing an in-depth study of methods and influencing factors to capture emergent semantics from Social Annotation Systems. We focus hereby on the acquisition of lexical semantics from the underlying networks of keywords, users and resources. Structured along different ontology learning tasks, we use a methodology of semantic grounding to characterize and evaluate the semantic relations captured by different methods. In all cases, our studies are based on datasets from several Social Annotation Systems. Specifically, we first analyze semantic relatedness among keywords, and identify measures which detect different notions of relatedness. These constitute the input of concept learning algorithms, which focus then on the discovery of synonymous and ambiguous keywords. Hereby, we assess the usefulness of various clustering techniques. As a prerequisite to induce hierarchical relationships, our next step is to study measures which quantify the level of generality of a particular keyword. We find that comparatively simple measures can approximate the generality information encoded in reference taxonomies. These insights are used to inform the final task, namely the creation of concept hierarchies. For this purpose, generality-based algorithms exhibit advantages compared to clustering approaches. In order to complement the identification of suitable methods to capture semantic structures, we analyze as a next step several factors which influence their emergence. Empirical evidence is provided that the amount of available data plays a crucial role for determining keyword meanings. From a different perspective, we examine pragmatic aspects by considering different annotation patterns among users. Based on a broad distinction between "categorizers" and "describers", we find that the latter produce more accurate results. This suggests a causal link between pragmatic and semantic aspects of keyword annotation. As a special kind of usage pattern, we then have a look at system abuse and spam. While observing a mixed picture, we suggest that an individual decision should be taken instead of disregarding spammers as a matter of principle. Finally, we discuss a set of applications which operationalize the results of our studies for enhancing both Social Annotation and semantic systems. These comprise on the one hand tools which foster the emergence of semantics, and on the one hand applications which exploit the socially induced relations to improve, e. g., searching, browsing, or user profiling facilities. In summary, the contributions of this work highlight viable methods and crucial aspects for designing enhanced knowledge-based services of a Social Semantic Web.

Integrating top down policies and bottom up practices in Urban and Periurban Agriculture: an Italian dilemma

The paper deals with some relevant and contradictory aspects of urban and peri-urban agriculture in Italy: the traditional exclusion of agricultural areas from the goals of territorial planning; the separation between top-down policies and bottom-up practices; the lack of agricultural policies at local scale. In the first part the paper summarises the weak relation between urban planning and agriculture, showing how in Italy this gap has been only partially overcome by new laws and plans. Moreover the paper focuses on how, due to the lack of suitable solutions coming from regional and local planning, a large number of vibrant initiatives were started by local stakeholders. In order to show the limitations and the potentialities of these various approaches, three peculiar experiences based on Milan, Turin and Pisa are presented. They give a cross-section of the variegated Italian situation, demonstrating that a major challenge in Italian context affects the fields of governance and inclusiveness.

A simple retroelement based knock-down system in Dictyostelium

Characteristics of DIRS-1 Mediated Knock-Downs __ We have previously shown that the most abundant Dictyostelium discoideum retroelement DIRS-1 is suppressed by RNAi mechanisms. Here we provide evidence that both inverted terminal repeats have strong promoter activity and that bidirectional expression apparently generates a substrate for Dicer. A cassette containing the inverted terminal repeats and a fragment of a gene of interest was sufficient to activate the RNAi response, resulting in the generation of ~21 nt siRNAs, a reduction of mRNA and protein expression of the respective endogene. Surprisingly, no transitivity was observed on the endogene. This was in contrast to previous observations, where endogenous siRNAs caused spreading on an artificial transgene. Knock-down was successful on seven target genes that we examined. In three cases a phenotypic analysis proved the efficiency of the approach. One of the target genes was apparently essential because no knock-out could be obtained; the RNAi mediated knock-down, however, resulted in a very slow growing culture indicating a still viable reduction of gene expression.

Investigation of Multiphase Power Converter using Integrated Coupled Inductor Regarding Electric Vehicle Application

The challenge of reducing carbon emission and achieving emission target until 2050, has become a key development strategy of energy distribution for each country. The automotive industries, as the important portion of implementing energy requirements, are making some related researches to meet energy requirements and customer requirements. For modern energy requirements, it should be clean, green and renewable. For customer requirements, it should be economic, reliable and long life time. Regarding increasing requirements on the market and enlarged customer quantity, EVs and PHEV are more and more important for automotive manufactures. Normally for EVs and PHEV there are two important key parts, which are battery package and power electronics composing of critical components. A rechargeable battery is a quite important element for achieving cost competitiveness, which is mainly used to story energy and provide continue energy to drive an electric motor. In order to recharge battery and drive the electric motor, power electronics group is an essential bridge to convert different energy types for both of them. In modern power electronics there are many different topologies such as non-isolated and isolated power converters which can be used to implement for charging battery. One of most used converter topology is multiphase interleaved power converter, pri- marily due to its prominent advantages, which is frequently employed to obtain optimal dynamic response, high effciency and compact converter size. Concerning its usage, many detailed investigations regarding topology, control strategy and devices have been done. In this thesis, the core research is to investigate some branched contents in term of issues analysis and optimization approaches of building magnetic component. This work starts with an introduction of reasons of developing EVs and PEHV and an overview of different possible topologies regarding specific application requirements. Because of less components, high reliability, high effciency and also no special safety requirement, non-isolated multiphase interleaved converter is selected as the basic research topology of founded W-charge project for investigating its advantages and potential branches on using optimized magnetic components. Following, all those proposed aspects and approaches are investigated and analyzed in details in order to verify constrains and advantages through using integrated coupled inductors. Furthermore, digital controller concept and a novel tapped-inductor topology is proposed for multiphase power converter and electric vehicle application.

Atenci??n educativa al alumnado s??ndrome de down

Se presenta experiencia educativa que propone la obtenci??n de un mayor conocimiento sobre el alumnado con s??ndrome de down para atender mejor a sus necesidades. Se realiza en el CEIP Julio Rodr??guez en Armilla, Granada y en el IES Chauchina en Chauchina, Granada. Los objetivos son: conocer las caracter??sticas del alumnado con retraso mental; detecci??n y valoraci??n ajustada de sus capacidades y necesidades educativas especiales; dise??ar y elaborar propuestas curriculares adaptadas a sus estilos de aprendizaje; conocer las respuestas, opciones educativas y medidas adecuadas para este alumnado; autoformarnos y recopilar material relacionado con la tem??tica; b??squeda y an??lisis de materiales innovadores para la intervenci??n educativa y atenci??n a la diversidad del alumnado escolar; mejorar nuestra pr??ctica docente.

Plan integral para la formación, el empleo y la vida independiente para las personas con Síndrome de Down y otras discapacidades psíquicas.

Figuran como colaboradores las profesoras Nuria Illán y María Ángeles García Cerdá de la Universidad de Murcia

Socio-affective development in infants with Down' s Syndrome. 'Desarrollo socio-afectivo en ni??os con s??ndrome de Down'

El libro es el resultado de la compilaci??n de las colaboraciones de expertos internacionales reunidos en un Simposio Internacional sobre Psicolog??a y Psicobiolog??a Educativa e Integraci??n Social de las personas con S??ndrome de Down, organizado por Juan Perera (Asociaci??n S??ndrome de Down de Baleares. Universidad de las Islas Baleares) y Jean A. Rondal (Laboratorio de Psicoling????stica de la Universidad de Lieja, B??lgica), bajo los auspicios del Gobierno Balear y otras instituciones y organismos. La colaboraci??n de los autores murcianos (Candel, Carranza y P??rez L??pez) versa sobre el desarrollo socio-afectivo de los ni??os afectados por el S??ndrome y presenta los resultados de una investigaci??n longitudinal sobre el temperamento de los ni??os con s??ndrome Down. Los objetivos de la investigaci??n son: el estudio de los componentes temperamentales en el desarrollo de los ni??os con S??ndrome Down. La evaluaci??n del grado de estabilidad/inestabilidad de las diferencias temperamentales en los ni??os con S??ndrome Down y an lisis del grado de homogeneidad de los componentes temperamentales de estos ni??os como grupo y las diferencias con un grupo de control de ni??os no retrasados. Los resultados confirman la existencia de diferencias individuales en el temperamento de los ni??os con S??ndrome Down.

Estimulación precoz en niños con síndrome de Down.

1) Confeccionar una 'escala de aptitudes' que partiendo de hechos y datos establecidos en Neurología evolutiva y Psicología sirvieran para un triple fin: ver a qué nivel está el niño, programar a partir de ese nivel la aptitud y ejercicios a realizar, y que la misma escala sirva de registro de control. 2) Aplicar un programa de estimulación precoz a una muestra representativa de niños asturianos con síndrome de Down; valorar su eficacia, la dependencia con el momento de su iniciación, con la colaboración familiar, el nivel socio-cultural y económico de los padres y la repercusión de la patología asociada. 51 niños divididos en grupos por semestres dependiendo del momento de iniciación de la estimulación precoz. Seguimiento global de 838 días y un control de 13.224 aptitudes. Para la elaboración del manual de perfiles de desarrollo de aptitudes: 1) análisis de investigaciones semejantes de estimulación precoz en niños con síndrome de Down o en deficientes mentales; 2) análisis de los sistemas de control de la evolución del niño deficiente. Para su aplicación: 1) informatización del expediente, ficha de factores familiares y manual de control de cada niño; 2) elaboración de una ficha médica que recogiese algunos factores familiares; 3) elaboración de un método de aprendizaje y programación de actitudes a enseñar a cada niño y modo de desarrollar tal enseñanza. 1) El manual de perfiles de desarrollo de aptitudes sirve tanto para indicar el nivel de maduración del niño, como para orientar sobre las aptitudes que se le deben enseñar. Se aplica a niños de 0 a 24 meses, abarca el desarrollo evolutivo global y comprende las 4 áreas clásicas del mismo. 2) Su programa de información permite: conocer automática e inmediatamente la evolución de cada niño, comparar al niño con el grupo de pertenencia y contrastar su evolución con la de niños normales y con la de niños con síndrome de Down que no han recibido estimulación precoz y valorar su eficacia. 3) Los niños con síndrome de Down que han recibido estimulación precoz desde el primer semestre de vida obtienen tempranamente aptitudes de las cuatro áreas de desarrollo. 4) La diferencia entre grupos de edades cronológicas afines es más evidente a partir de los 12 meses. 5) La estimulación precoz es tanto o más beneficiosa cuanto más tempranamente se empiece. 6) La motricidad se adquiere antes que las demás aptitudes y las del área social se asimilan más tarde. 7) La colaboración de los padres fue quizás uno de los factores que más influyó en los resultados. 8) No se observa relación directa entre su grado de colaboración y el nivel socio-económico. 9) La patología asociada en el síndrome de Down es quizás un factor importante en el éxito o fracaso del programa realizado.

Numerical Simulation of Electroosmotic Flow with Step Change in Zeta Potential

Electroosmotic flow is a convenient mechanism for transporting polar fluid in a microfluidic device. The flow is generated through the application of an external electric field that acts on the free charges that exists in a thin Debye layer at the channel walls. The charge on the wall is due to the chemistry of the solid-fluid interface, and it can vary along the channel, e.g. due to modification of the wall. This investigation focuses on the simulation of the electroosmotic flow (EOF) profile in a cylindrical microchannel with step change in zeta potential. The modified Navier-Stoke equation governing the velocity field and a non-linear two-dimensional Poisson-Boltzmann equation governing the electrical double-layer (EDL) field distribution are solved numerically using finite control-volume method. Continuities of flow rate and electric current are enforced resulting in a non-uniform electrical field and pressure gradient distribution along the channel. The resulting parabolic velocity distribution at the junction of the step change in zeta potential, which is more typical of a pressure-driven velocity flow profile, is obtained.

Las danzas del folklore chileno aplicadas en los niños con Síndrome de Down.

Lograr que el niño con Síndrome de Down desarrolle la expresión musical por medio de danzas del folklore chileno a través de la elaboración de un material didáctico que permita trabajar con este tipo de niños. Las hipótesis de partida son: a) Si las danzas del folklore chileno son adaptadas para niños con Síndrome de Down, entonces podrán ejecutarse pudiendo así obtener un nuevo lenguaje de expresión y, por otro lado, los profesores de música podrán abordar un nuevo campo de desarrollo en la especialidad; b) Las bases del trabajo en los niños con Síndrome de Down servirán para abrir otros campos de desarrollo en la disciplina musical. 13 alumnos del Instituto de Desarrollo para niños con Síndrome de Down y otras deficiencias de Chile. Investigación exploratoria y descriptiva que parte de la observación de un grupo de sujetos a partir de la cual se establece un plan de trabajo acorde con sus conductas. Posteriormente se realiza un sondeo con el propósito de conocer la realidad de los educadores con respecto al aprendizaje, estudio y aplicación de las danzas del folklore chileno en los niños con Síndrome de Down y de la importancia que tiene el aprendizaje de las danzas. Se selecciona un grupo de estudio que pueda seguir instrucciones en lo que respecta al desplazamiento en el tiempo y el espacio, para realizar una etapa de enseñanza-aprendizaje en la cuál se van evaluando de manera formativa y cualitativa la capacidad de retención de la coreografía, pasos, sincronización con las frases musicales y con la pareja de baile. Encuesta dirigida a educadores que pretende detectar la realidad de la enseñanza-aprendizaje en los niños con Síndrome de Down. Registro de observación sobre las aptitudes de los niños en las clases de danza. a) Poca importancia de la actividad artística-musical en los niños con Síndrome de Down debido a la falta de preparación de profesores de Educación Musical; b) Desconocimiento por parte de los directores de escuelas especiales, profesores y administrativos de la educación de la relevancia que tiene el quehacer musical en niños con este síndrome; c) Los conocimientos que entregan las diferentes universidades son destinados específicamente a preparar a profesores de Educación Musical para trabajar con alumnos normales y no de Educación Especial; d) El niño con Síndrome de Down manifiesta capacidad para aprender una coreografía en cuanto al paso y desplazamiento que una danza de folklore chileno así lo exige; e) La enseñanza de las danzas pierde su continuidad debido a las características especificas de este grupo de sujetos.