The objective of this study is to elucidate the efficiency of enation-structure (at node) recognition method at pre-flowing stage and to understand the population genetic variation of the Mikania weeds in Taiwan. The plant materials collected by recognizing enation-structure symptom method from North, Central, South and East Taiwan and off-shore islands. Using PCR¡V sequencing marker techniques, the sequencing revealed that nrDNA ITS region could identify three Mikania weeds and the 97% similarity of phylogenetic relationship between M.cordata and M.micrantha are more closer than that between M.cordata and M.scandens, whose ITS sequence is obtained from GeneBank. However ,the sequences of chloroplast DNA of M.cordata and M.micrantha at trnL intron¡]436bp¡^or trnL-trnF IGS¡]345 bp¡^are almost the same and could not be used as molecular markers. The recognizing techniques of enation-structure was supported by the nrDNA ITS region and ISSR results at the end, thus the finding can be recommended to the Council of Agriculture in order to eliminate the weed and to reduce the impact on M.cordata, which is native in Taiwan. Moreover, the findings of ISSR analysis in the aspect of population genetic variation indicated that high genetic differentiation ¡]Gst>0.5¡^was found among the M. cordata and M.micrantha populations. Based on the Mantle test, there was no relationship between genetic distance and geographic distance in M.micrantha¡]r=0.0053,p=0.47¡^.This phenomenon revealed that populations of M.micrantha had complex population variability within the short-term invaded into Taiwan that might be resulted from the random dispersion of human activities. The population of M.micrantha was established by few individuals (founders) and grown rapidly in Taiwan, resulting in population differentiation via genetic drift. In contrast to M.micrantha ,there was relationship between genetic distance and geographic distance in M.cordata ¡]r=0.44,p=0.025¡¯¡^.It revealed that populations of M.cordata agreed to the concept of isolation by distance model, which might be evolved from the result of natural dispersion. In conclusion, the population structure of M.micrantha in Taiwan is stable , suggesting that control of Mikania population should be based on different populations where have large differentiation among them .

A DNA sequence-based phylogenetic tree (Dillon et al., 2004) places the species of the genus Sorghum into two sister lineages, one with x = 5 and the other with x = 10 as a basic chromosome number. It has not been resolved whether or not these lineages are monophyletic or polyphyletic. A repetitive sequence, CEN38, found only in Sorghum and sugarcane, was used to assess evolutionary relationships among Sorghum species. The objectives of this research were to determine the taxonomic distribution of CEN38, its chromosomal position(s), and its organization in DNA. CEN38 was detected by filter hybridization to be present in the DNA of 16 of 21 Sorghum species analyzed, ranging from 15 to ~21,000 copies. It was detected by fluorescence in situ hybridization (FISH) only in chromosomes of species of the section Eu-sorghum, where it had a pericentromeric distribution. The low copy number and/or chromosomal distribution of CEN38 in other Sorghum species apparently does not allow for its detection by FISH. Analysis of restriction enzyme digested DNA with homology to CEN38 and of fragments amplified by PCR using primers selected to amplify S. bicolor CEN38 sequences showed that S. laxiflorum and S. macrospermum have tandemly arranged CEN38 sequences as is found in S. bicolor. This supports the close evolutionary affinity of the species in the x = 10 lineage. In the x = 5 lineage, DNA of 11 of 16 species analyzed hybridized with CEN38 by filter hybridization. In S. versicolor, large DNA fragments (4.36 kb to 23 kb) generated by digestion with restriction enzymes hybridized to CEN38. Since a ladder of smaller fragments was not detected, CEN38 may have been inserted into a transposable element in this species and dispersed throughout the genome. Among species of the x = 5 lineage, PCR using primers for S. bicolor CEN38 amplified only DNA fragments from S. timorense and these formed a ladder based on a ~125 bp repeat. Since hybridization of the CEN38 sequence to DNA of S. timorense was not detected by filter hybridizations, these sequences apparently are not similar to CEN38. Cloning and sequencing of DNA from species of the x = 5 lineage that hybridizes to CEN38 are needed to determine whether or not they are in the CEN38 family. A monophyletic or polyphyletic origin of the x = 5 and x = 10 lineages was not resolved.

The main goal of this research is to understand molecular mechanisms of GAA/TTC-associated genetic instability in a model eukaryotic organism, S. cerevisiae. We demonstrate that expanded GAA/TTC repeats represent a threat to eukaryotic genome integrity by triggering double-strand breaks and gross chromosomal rearrangements. The fragility potential strongly depends on the length of the tracts and orientation of the repeats relative to the replication origin and to block replication fork progression. MutSbeta complex and endonuclease activity of MutLalpha play an important role in facilitation of fragility. In addition to GAA/TTC triplex forming repeats, non-GAA polypurine polypyrimidine mirror repeats that are prone to the formation of similar structures were found to be hotspots for rearrangements in humans and other model organisms. These include H-DNA forming sequences located in the major breakpoint cluster region at BCL2, intron 21 of PKD1, and promoter region of C-MYC. Lastly, we have investigated the effect of the triplex-binding small molecules, azacyanines, on GAA-mediated fragility using the chromosomal arm loss assay. We have found that in vivo, azacyanines stimulate (GAA/TTC)-mediated arm loss in a dose dependent manner in actively dividing cells. Azacyanines treatment enhances the GAA-induced replication arrest. We discovered that also, azacyanines at concentrations that induce fragility also inhibit cell growth. Over 60% of yeast cells are arrested at G2/M stage of the cell cycle. This implies an activation of DNA-damage checkpoint response.

The Gravity Recovery and Climate Experiment (GRACE) has been orbiting the Earth and determining its gravity field since 2002. Throughout the course of the mission, the orbital elements occasionally change such that the satellites enter a repeat ground track configuration. Repeat ground tracks result in reduced spatial resolution of the satellites, which poses problems in the context of gravity recovery. The monthly gravity solutions during these periods are examined and shown to have lower quality than usual. The characteristics of these repeat period solutions are identified and compared to a period of uniform coverage to illustrate the ways in which the solutions are degraded. An investigation into the underlying physical and computational sources of these errors is also presented. / text

Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder, caused by a GAA repeat expansion mutation within intron 1 of the FXN gene, resulting in reduced level of frataxin protein. Normal individuals have 5 to 40 GAA repeat sequences, whereas affected individuals have approximately 70 to more than 1000 GAA triplets. Frataxin is a mitochondrial protein involved in iron-sulphur cluster and heme biosynthesis. The reduction in frataxin expression leads to oxidative stress, mitochondrial iron accumulation and consequential cell death with the primary sites of neurons of the dorsal root ganglia and the dentate nucleus of the cerebellum. FRDA, which is the most common inherited ataxia, affecting 1:50,000 Caucasians, is characterised by neurodegeneration, cardiomyopathy, diabetes mellitus and skeletal deformities. To investigate FRDA molecular disease mechanisms and therapy, several human FXN YAC transgenic mouse models have been established: Y47R, containing normal-sized (GAA)9 repeats; YG8R and YG22R, which initially contained expanded GAA repeats of 90-190 units and 190 units, respectively, but which have subsequently been bred to now contain expanded GAA repeats of 120-220 units and 170-260 units, respectively, and YG8sR (YG8R with a small GAA band) that was recently generated from YG8R breeding. To determine the FXN transgene copy number in the enhanced GAA repeat expansion-based FRDA mouse lines, a TaqMan qPCR assay was developed. The results demonstrated that the YG22R and Y47R lines had a single copy of the FXN transgene while the YG8R line had two copies. The YG8s lines showed less than one copy of the target gene, suggesting potential deletion of the FXN gene. Single integration sites of all transgenes were confirmed by fluorescence in situ hybridisation (FISH) analysis of metaphase and interphase chromosomes. However, in the YG8s line, at least 25% of the YG8s cells had no signals, while the remaining cells showed one signal corresponding to the transgenic FXN gene. In addition, the analysis of FXN exons in YG8s rescue mice by PCR confirmed the presence of all FXN exons in these lines, suggesting the incidence of somatic mosaicism in these lines. Extended functional analysis was carried out on these mice from 4 to 12 months of age. Coordination ability of YG8R, YG8sR and YG22R ‘FRDA-like’ mice, together with Y47R and C57BL6/J wild-type control mice, was assessed using accelerating rotarod analysis. The results indicated a progressive decrease in the motor coordination of YG8R, YG22R and YG8sR mice compared to Y47R or C57BL6/J controls. Locomotor activity was also assessed using an open field beam-breaker apparatus followed by four additional functional analyses including beam-walk, hang wire, grip strength and foot print tests. The results indicated significant functional deficits in the FRDA mouse models. Glucose and insulin tolerance tests were also conducted in the FRDA mouse models, indicating glucose intolerance and insulin hypersensitivity in the aforementioned lines. To investigate the correlation between the FRDA-like pathological phenotype and frataxin deficiency in the FRDA mouse models, frataxin mRNA and protein levels as well as somatic GAA repeat instability were examined. The results indicated that somatic GAA repeats increased in the cerebellum and brain of YG22R, YG8R and YG8sR mice, together with significantly reduced levels of FXN mRNA and protein in the liver of YG8R and YG22R compared to Y47R. However, YG8sR lines showed a significant decrease in FXN mRNA in all of the examined tissues compared to Y47R human FXN and C57BL6/J mouse Fxn mRNA. Protein expression levels were also considerably reduced in all the tissues of YG8sR mice compared to Y47R. Subsequently, the telomere length of human and mouse FRDA and control fibroblasts was assessed using qPCR and Q-FISH. The results indicated that the FRDA cells had chromosomes with relatively longer telomeric repeats in comparison to the controls. FRDA cells were screened for expression of telomerase activity using the TRAP assay and a quantitative assay for hTERT mRNA expression using TaqMan qRT-PCR. The results indicated that telomerase activity was not present in the FRDA cells. To investigate whether FRDA cells maintained their telomeres by ALT associated PML bodies (APBs), co-localisation of PML bodies with telomeres was assessed in these cells using combined immunofluorescence to PML and Q-FISH for telomere detection. The results demonstrated that the FRDA cells had significantly higher co-localised PML foci with telomeric DNA compared to the normal cells. Moreover, telomere sister chromatid exchange (T-SCE) frequencies were analysed in the human FRDA cell lines using chromosome orientation FISH (CO-FISH). The results indicated a significant increase in T-SCE levels of the FRDA cell lines relative to the controls. Furthermore, growth curve and population doubling analysis of the human FRDA and control fibroblasts was carried out. The results showed that the FRDA fibroblast cell cultures underwent growth arrest with higher cumulative population doubling compared to the controls. Though, further analysis of telomere length at different passage numbers revealed that the FRDA cells lost telomeres faster than the controls. Finally, the telomere dysfunction-induced foci (TIF) assay was performed to detect DNA damage in the human FRDA fibroblast cells using an antibody against DNA damage marker γ-H2AX and a synthetic PNA probe for telomeres. The frequency of γ-H2AX foci was significantly higher in the FRDA cells compared to the controls. Similarly, the FRDA cells had greater frequencies of TIFs in comparison to the controls, suggesting induced telomere dysfunction in the FRDA cells.

La transmisión asistida por relay o transmisión cooperativa es una nueva técnica de diversidad espacial donde aparece un elemento nuevo (un relay o un usuario cooperativo) en la tradicional transmisión punto a punto (fuente a destino). Ahora en la comunicación intervienen tres enlaces: fuente-relay, relay-destino y fuente-destino. El relay, además de asistir a la fuente en la transmisión de un mensaje, permite combatir las degradaciones que puede sufrir el canal como el shadowing y el pathloss. Aunque esta técnica está basada en el trabajo realizado en los 70 por Van der Meulen, Cover y El Gamal, ha sido en los últimos años cuando se han vuelto a considerar el uso de relays. En realidad, la transmisión asistida por un relay puede verse como un sistema virtual multi-antena (virtual MIMO) donde las antenas están distribuidas en diferentes terminales. Sin embargo, al contrario de los sistemas multi-antena y debido a la limitación de la actual tecnología radio, el relay debe trabajar en modo half-duplex, ya que no puede transmitir y recibir simultáneamente en la misma banda. Este hecho, motiva que la transmisión deba realizarse en dos fases ortogonales en función del modo del relay (recibiendo datos - relay-receive phase o transmitiendo datos - relay-transmit phase). Estas fases pueden implementarse en el dominio de la frecuencia o el tiempo.Esta tesis investiga protocolos y estrategias para la transmisión asistida por relay para mejorar la eficiencia espectral y homogeneizar el servicio para todos los usuarios en un sistema de comunicación celular. La introducción del relay en la comunicación implica la redefinición de muchas técnicas y protocolos considerados en las comunicaciones punto a punto y en los sistemas multi-antena, situados en la capa física y/o superiores.En primer lugar se presentan los achievable rates obtenidos por la transmisión asistida por relay en función del rol del relay (amplifica y retransmite o decodifica y retransmite), el tipo de transmisión (siempre transmite, incremental o selectiva), los datos transmitidos por el relay (repite los símbolos recibidos o son independientes) y el tipo del protocolo half duplex. En función de los terminales activos en cada fase de la comunicación (fuente, destino o relay), existen hasta cuatro protocolos. Otro aspecto considerado es la asignación de recursos (resource allocation) para cada fase de la comunicación, la cual puede estar fijada de antemano o puede ser ajustada dinámicamente en función de los canales de los diferentes enlaces. En el caso de que todos los coeficientes del canal se conocieran perfectamente, los terminales podrían transmitir síncronamente, mejorando la comunicación gracias a la ganancia debida a técnicas de pre-codificación por medio de los autovectores del canal (con antenas distribuidas).Además dos técnicas de transmisión asistida por relay son evaluadas cuando existen múltiples relays por destino. Ambas dependen del tipo de mensajes transmitidos a cada relay (mensajes independientes o uno común). La asignación de recursos para ambas técnicas puede verse como un problema convexo.Tres escenarios resumen diferentes tipos de transmisión asistida por relay para múltiples fuentes y un solo destino: RMAC (Relay-assisted Multiple Access Channel), UC (User Cooperation) and MARC (Multiple Access Relay Channel). Su diferencia se basa en el tipo de relay half- duplex considerado. La transmisión puede hacerse síncrona o asíncronamente. Las fuentes y los relays están limitados en potencia y el acceso de ellos en cada fase de la comunicación pude hacerse por medio de TDMA (time division multiple access), FDMA (frequency division multiple access) or SC (superposition coding multiple access). La asignación de recursos puede ser formulada como un problema convexo en algunos casos y la solución óptima puede ser encontrada. Seguidamente la transmisión asistida por relay y duplexada en tiempo es aplicada a un sistema celular centralizado basado en TDMA en el downlink. Con el objetivo de mejorar la eficiencia espectral se propone el reuso espacial de un slot temporal para las transmisiones de los relays hacia sus respectivos destinos (slot de relay), generando interferencia para todos los restantes destinos activos. Un algoritmo de control de potencia basado en la teoría de juegos es propuesto para combatir la interferencia generada. Bajo esa configuración, un algoritmo de scheduling investiga las posibles ganancias debidas al multi-user gain y mide el overhead introducido.Otra forma de tratar con la interferencia es la de controlar el rate de nuestra transmisión (rate control management). Bajo ciertas condiciones es posible modelar la función de densidad de probabilidad de la potencia interferente. En ese caso, la fuente ajusta el rate para maximizar el throughput de la comunicación. Esta solución es extendida para el caso en el que cada destino es asistido por varios relays. Las dos soluciones propuestas son capaces de proporcionar mejores resultados que la transmisión directa, a pesar de la interferencia existente en el slot de relay. Finalmente, se investiga el control dinámico del enlace para la transmisión asistida por relay con dos diferentes tipos de conocimiento sobre el canal: conocimiento estadístico (statistical knowledge of the channel state) o conocimiento del canal instantáneo (actual information about the current channel state).Estos dos tipos de conocimiento derivan en diferentes estrategias a utilizar para seleccionar la modulación y el esquema de codificación (MCS). En el primer caso, los rates seleccionados no están adaptados al canal actual, por lo que el destino puede recibir erróneamente los mensajes. Los protocolos de retransmisión de mensajes (ARQ - automatic repeat request) son los encargados de asegurarse la correcta recepción y son redefinidos para la transmisión asistida por relay.. En este trabajo, se especifica los códigos espacio-tiempo distribuidos, la codificación en al fuente y el relay y la longitud de las retransmisiones. Cuando la fuente conoce algún parámetro del canal instantáneo puede adaptar el MCS para esa realización del canal. En ese caso se investiga la predicción del error en las transmisiones asistidas por relay, y con ello es posible diseñar el MCS para que maximice la cantidad de información transmitida para una probabilidad de pérdida de paquete o que maximice el throughput. / The relay-assisted or cooperative transmission is a relatively new class of spatial diversity technique where a new element comes up in the conventional source-destination or point-to point communication: an assisting relay or cooperating user. The relay assists to the source in transmitting a message to the destination and allows dealing with the channel impairments like shadowing and pathloss. Although the seminal works were issued in the 70's by van der Meulen, Cover and El Gamal, it has been during the last years when it has re-gained more attention by the researchers. In fact, the relay-assisted transmission can be seen as a virtual MIMO (Multiple Input Multiple Output) with distributed antennas. In contrast to MIMO systems, the transmission requires the use of additional channel resources because of the limitation of the current radio technology: the relay terminal is constrained to work in half-duplex mode, which motivates that the transmission must be carried out in two orthogonal phases (relay-receive and relay-transmit phase), duplexed in time or frequency domains.This dissertation investigates protocols and strategies for the relay-assisted transmission which improve the spectral efficiency and homogenize service in the cellular communication systems. The new element present in the communication, the relay terminal, imposes a redefinition of many techniques and protocols commonly used in the point-to-point and MIMO systems, which are placed at the physical and upper layers.First, achievable rates using the relay-assisted transmission are provided which depend on the role of the relay (amplify-and-forward or decode-and-forward), the type of the transmission (persistent transmission, incremental or selective relaying), the data transmitted by the relays (repetition or unconstrained coding) and the type of half-duplex protocol. There are up to four protocol definition depending on the activity of the terminals on each phase. An additional aspect addressed is the resource allocation for each phase, that is, either it is fixed beforehand (static) or it is adjusted dynamically (dynamic) as a function of the channel quality. For the single-user relay- assisted transmission the resources can be allocated based on the channel quality of the different links. Moreover, if there is complete channel state information about all channel coefficients, source and relay can transmit synchronously enhancing the transmission thanks to the (distributed) eigenvector precoding techniques.Two relay-assisted transmission techniques are evaluated when a destination is assisted by multiple relays. Both depend on the messages intended to each assisting relay (independent or common messaging). The resource allocation for both techniques is shown to be convex. Additionally, three different scenarios illustrate the multi-user relay-assisted transmission with a single destination and different types of half-duplex relays: RMAC (Relay-assisted Multiple Access Channel), UC (User Cooperation) and MARC (Multiple Access Relay Channel). The relay-assisted transmission can be done synchronously or asynchronously. The sources and relays are power limited and access in each phase of the communication by TDMA (time division multiple access), FDMA (frequency division multiple access) or SC (superposition coding multiple access). For those scenarios the allocation of transmitted power and time resources can be formulated as a convex problem under some circumstances, evaluating the optimal solution.Afterwards, the relay-assisted transmission duplexed in time is applied to a centralized cellular system based on TDMA in the downlink. The reuse of one time slot for the transmissions done from the relays to destinations (relay slot) is proposed to improve the spectral efficiency. This solution produces interference for all the destinations active in that time slot. A power control algorithm (at the relays) based on game theory is proposed to combat the generated interference. Under that configuration a scheduler algorithm explores the multi-user gain for the relay-assisted transmission, measuring the introduced overhead.Another way of dealing with the interference is by rate control management. Under some circumstances it is possible to model the probability density function (pdf) of the interfering power. In such a case, the source can tune the transmission rate in order to maximize the throughput. This solution is extended to the case where each destination is assisted by multiple relays. In spite of the interfering power, both proposed solutions are able to provide significant gains over the direct transmission.Finally, the dynamic link control of the relay assisted transmission is investigated under two different assumptions on the knowledge about the channel: statistical knowledge of the channel state and actual information about the current channel state. Both types of knowledge lead to different transmission strategies, in terms of selecting the modulation and coding scheme (MCS). Under the first case, the transmission rates are not adapted to the current channel realization and the destination can decode wrongly the messages. The Automatic Repeat reQuest (ARQ) protocols are redefined for the relayassisted transmission to cope with these events. In this work we specify the (distributed) space-time codes, the coding at the source and relay and the length of the retransmissions. When there is actual information about the channel state the MCS can be adapted to the current channel realization. In such a case, the link error prediction for the relay-assisted transmission is investigated, and thus the MCS can be designed for maximizing the information rate for a given probability of packet loss or maximizing the throughput.

alpha-actinin is a ubiquitous protein found in most eukaryotic organisms. The ability to form dimers allows alpha-actinin to cross-link actin in different structures. In muscle cells alpha-actinin is found at the Z-disk of sarcomeres. In non-muscle cells alpha-actinin is found in zonula adherens or focal adhesion sites where it can bind actin to the plasma membrane. alpha-actinin is the shortest member of the spectrin superfamily of proteins which also includes spectrin, dystrophin and utrophin. Several hypotheses suggest that alpha-actinin is the ancestor of this superfamily. The structure of alpha-actinin in higher organisms has been well characterized consisting of three main domains: an N-terminal actin-binding domain with two calponin homology domains, a central rod domain with four spectrin repeats and a C-terminal calcium-binding domain. Data mining of genomes from diverse organisms has made possible the discovery of new and atypical alpha-actinin isoforms that have not been characterized yet. Invertebrates contain a single alpha-actinin isoform, whereas most of the vertebrates contain four. These four isoforms can be broadly classified in two groups, muscle isoforms and non-muscle isoforms. Muscle isoforms bind actin in a calcium independent manner whereas non-muscle isoforms bind actin in a calcium-dependent manner. Some of the protozoa and fungi isoforms are atypical in that they contain fewer spectrin repeats in the rod domain. We have purified and characterized two ancestral alpha-actinins from the parasite Entamoeba histolytica. Our results show that despite the shorter rod domain they conserve the most important functions of modern alpha-actinin such as actin-bundling formation and calcium-binding regulation. Therefore it is suggested that they are genuine alpha-actinins. The phylogenetic tree of alpha-actinin shows that the four different alpha-actinin isoforms appeared after the vertebrate-invertebrate split as a result of two rounds of genome duplication. The atypical alpha-actinin isoforms are placed as the most divergent isoforms suggesting that they are ancestral isoforms. We also propose that the most ancestral alpha-actinin contained a single repeat in its rod domain. After a first intragene duplication alpha-actinin with two spectrin repeats were created and a second intragene duplication gave rise to modern alpha-actinins with four spectrin repeats.

This research deals mainly with the impact of a family on an ineffectual studying of children. Unwillingness to study has become one of the most serious problems of general education. It is a very important reason for being absent from school, not attending lessons, repeating studies, and elimination from school. Students, who have to repeat their studies, quite often break them. Such kind of students and teenagers usually join the groups of unskilled labor force, unemployed people or even go with criminal gangs. From the social perspective the group of students who do not want to study and who are absent from school quite often is also problematic. They hate school and teachers, tramp in the streets, quite often use hard drink and drugs, smoke, and behave not socially. The aim of the research is to reveal the peculiarities of the families in which children study ineffectually. The goals of the research are: to analyze pedagogical and psychological literature researching the impact of a family on effective/ineffective studying; to interpret effective/ineffective studying in the context of new social changes and the process of education reform; to do the empirical research and to analyze the results from the perspective of social reasons (family) of ineffective studying. A survey has been carried out where questionnaires were given to the ineffectively studying students and their mentors, and the following conclusions could be proposed. Family atmosphere influences the... [to full text]

<p>NatA binds inositol hexakisphosphate and other ligands, and exhibits conformational flexibility dependent on the ligand bound.</p> / Dissertation

<p>The objective of the study was to conduct an internal validation on miniSTR systems and apply it to cases received from the South African Missing Persons Task Team (SAMPTT). This was prompted by the fact that miniSTR systems have been shown to out perform some of the commercial kits available in the time of the study and provide an alternative to mtDNA when analysing degraded DNA from skeletal remains and that the DNA extracted from skeletal remains received from the SAMPTT would be degraded due to the remains generally being fragmented or charred and buried for many years. The miniSTR loci chosen for validation comprised the Combined DNA Index System (CODIS) thirteen core loci and were arranged into four triplexes and one uniplex.</p>