Cryptic AUG is important for 48S ribosomal assembly during internal initiation of translation of coxsackievirus B3 RNA

We have investigated the possible role of a conserved cis-acting element, the cryptic AUG, present in the 5' UTR of coxsackievirus B3 (CVB3) RNA. CVB3 5' UTR contains multiple AUG codons upstream of the initiator AUG, which are not used for the initiation of translation. The 48S ribosomal assembly takes place upstream of the cryptic AUG. We show here that mutation in the cryptic AUG results in reduced efficiency of translation mediated by the CVB3 IRES; mutation also reduces the interaction of mutant IRES with a well characterized IRES trans-acting factor, the human La protein. Furthermore, partial silencing of the La gene showed a decrease in IRES activity in the case of both the wild-type and mutant. We have demonstrated here that the interaction of the 48S ribosomal complex with mutant RNA was weaker compared with wild-type RNA by ribosome assembly analysis. We have also investigated by chemical and enzymic modifications the possible alteration in secondary structure in the mutant RNA. Results suggest that the secondary structure of mutant RNA was only marginally altered. Additionally, we have demonstrated by generating compensatory and non-specific mutations the specific function of the cryptic AUG in internal initiation. Results suggest that the effect of the cryptic AUG is specific and translation could not be rescued. However, a possibility of tertiary interaction of the cryptic AUG with other cis-acting elements cannot be ruled out. Taken together, it appears that the integrity of the cryptic AUG is important for efficient translation initiation by the CVB3 IRES RNA.

Interplay between NS3 protease and human La protein regulates translation-replication switch of Hepatitis C virus

HCV NS3 protein plays a central role in viral polyprotein processing and RNA replication. We demonstrate that the NS3 protease (NS3(pro)) domain alone can specifically bind to HCV-IRES RNA, predominantly in the SLIV region. The cleavage activity of the NS3 protease domain is reduced upon HCV-RNA binding. More importantly, NS3(pro) binding to the SLIV hinders the interaction of La protein, a cellular IRES-trans acting factor required for HCV IRES-mediated translation, resulting in inhibition of HCV-IRES activity. Although overexpression of both NS3(pro) as well as the full length NS3 protein decreased the level of HCV IRES mediated translation, replication of HCV replicon RNA was enhanced significantly. These observations suggest that the NS3(pro) binding to HCV IRES reduces translation in favor of RNA replication. The competition between the host factor (La) and the viral protein (NS3) for binding to HCV IRES might regulate the molecular switch from translation to replication of HCV.

Annexin A2 and PSF proteins interact with p53 IRES and regulate translation of p53 mRNA

p53 mRNA has been shown to be translated into two isoforms, full-length p53 (FL-p53) and a truncated isoform Delta N-p53, which modulates the functions of FL-p53 and also has independent functions. Previously, we have shown that translation of p53 and Delta N-p53 can be initiated at Internal Ribosome Entry Sites (IRES). These two IRESs were shown to regulate the translation of p53 and Delta N-p53 in a distinct cell-cycle phase-dependent manner. Earlier observations from our laboratory also suggest that the structural integrity of the p53 RNA is critical for IRES function and is compromised by mutations that affect the structure as well as RNA protein interactions. In the current study, using RNA affinity approach we have identified Annexin A2 and PTB associated Splicing Factor (PSF/SFPQ) as novel ITAFs for p53 IRESs. We have showed that the purified Annexin A2 and PSF proteins specifically bind to p53 IRES elements. Interestingly, in the presence of calcium ions Annexin A2 showed increased binding with p53 IRES. Immunopulldown experiments suggest that these two proteins associate with p53 mRNA ex vivo as well. Partial knockdown of Annexin A2 and PSF showed decrease in p53 IRES activity and reduced levels of both the p53 isoforms. More importantly the interplay between Annexin A2, PSF and PTB proteins for binding to p53mRNA appears to play a crucial role in IRES function. Taken together, our observations suggest pivotal role of two new trans-acting factors in regulating the p53-IRES function, which in turn influences the synthesis of p53 isoforms.

Distinctive contributions of the ribosomal P-site elements m(2)G966, m(5)C967 and the C-terminal tail of the S9 protein in the fidelity of initiation of translation in Escherichia coli

The accuracy of pairing of the anticodon of the initiator tRNA (tRNA(fMet)) and the initiation codon of an mRNA, in the ribosomal P-site, is crucial for determining the translational reading frame. However, a direct role of any ribosomal element(s) in scrutinizing this pairing is unknown. The P-site elements, m(2)G966 (methylated by RsmD), m(5)C967 (methylated by RsmB) and the C-terminal tail of the protein S9 lie in the vicinity of tRNA(fMet). We investigated the role of these elements in initiation from various codons, namely, AUG, GUG, UUG, CUG, AUA, AUU, AUC and ACG with tRNA(CAU)(fmet) (tRNA(fMet) with CAU anticodon); CAC and CAU with tRNA(GUG)(fme); UAG with tRNA(GAU)(fMet) using in vivo and computational methods. Although RsmB deficiency did not impact initiation from most codons, RsmD deficiency increased initiation from AUA, CAC and CAU (2- to 3.6-fold). Deletion of the S9 C-terminal tail resulted in poorer initiation from UUG, GUG and CUG, but in increased initiation from CAC, CAU and UAC codons (up to 4-fold). Also, the S9 tail suppressed initiation with tRNA(CAU)(fMet)lacking the 3GC base pairs in the anticodon stem. These observations suggest distinctive roles of 966/967 methylations and the S9 tail in initiation.

Integrated relative translation and rotation control of spacecraft formations

Formation flying of small spacecraft provides a way to improve the resolution by aperture distribution. This requires autonomous control of relative position and relative attitude. The present work addresses the formation control using a PID controller to maintain both relative position and relative attitude. To avoid continuous pulsing due to noise, a dead-band has been provided in the position loop. PID control has been selected to maintain the formation in the presence of unmodeled disturbances. Simulations show that the proposed controller meets the required translational and rotational relative motions even in the presence of disturbances.

The translation initiation factor DAP5 promotes IRES-driven translation of p53 mRNA

Translational regulation of the p53 mRNA can determine the ratio between p53 and its N-terminal truncated isoforms and therefore has a significant role in determining p53-regulated signaling pathways. Although its importance in cell fate decisions has been demonstrated repeatedly, little is known about the regulatory mechanisms that determine this ratio. Two internal ribosome entry sites (IRESs) residing within the 5'UTR and the coding sequence of p53 mRNA drive the translation of full-length p53 and Delta 40p53 isoform, respectively. Here, we report that DAP5, a translation initiation factor shown to positively regulate the translation of various IRES containing mRNAs, promotes IRES-driven translation of p53 mRNA. Upon DAP5 depletion, p53 and Delta 40p53 protein levels were decreased, with a greater effect on the N-terminal truncated isoform. Functional analysis using bicistronic vectors driving the expression of a reporter gene from each of these two IRESs indicated that DAP5 preferentially promotes translation from the second IRES residing in the coding sequence. Furthermore, p53 mRNA expressed from a plasmid carrying this second IRES was selectively shifted to lighter polysomes upon DAP5 knockdown. Consequently, Delta 40p53 protein levels and the subsequent transcriptional activation of the 14-3-3 sigma gene, a known target of Delta 40p53, were strongly reduced. In addition, we show here that DAP5 interacts with p53 IRES elements in in vitro and in vivo binding studies, proving for the first time that DAP5 directly binds a target mRNA. Thus, through its ability to regulate IRES-dependent translation of the p53 mRNA, DAP5 may control the ratio between different p53 isoforms encoded by a single mRNA.

Is the cellular initiation of translation an exclusive property of the initiator tRNAs?

Translation of mRNAs is the primary function of the ribosomal machinery. Although cells allow for a certain level of translational errors/mistranslation (which may well be a strategic need), maintenance of the fidelity of translation is vital for the cellular function and fitness. The P-site bound initiator tRNA selects the start codon in an mRNA and specifies the reading frame. A direct P-site binding of the initiator tRNA is a function of its special structural features, ribosomal elements, and the initiation factors. A highly conserved feature of the 3 consecutive G:C base pairs (3GC pairs) in the anticodon stem of the initiator tRNAs is vital in directing it to the P-site. Mutations in the 3GC pairs diminish/abolish initiation under normal physiological conditions. Using molecular genetics approaches, we have identified conditions that allow initiation with the mutant tRNAs in Escherichia coli. During our studies, we have uncovered a novel phenomenon of in vivo initiation by elongator tRNAs. Here, we recapitulate how the cellular abundance of the initiator tRNA, and nucleoside modifications in rRNA are connected with the tRNA selection in the P-site. We then discuss our recent finding of how a conserved feature in the mRNA, the Shine-Dalgarno sequence, influences tRNA selection in the P-site.

Translation Induction on Indian Language Corpora Using Translingual Themes from Other Languages

Identifying translations from comparable corpora is a well-known problem with several applications, e.g. dictionary creation in resource-scarce languages. Scarcity of high quality corpora, especially in Indian languages, makes this problem hard, e.g. state-of-the-art techniques achieve a mean reciprocal rank (MRR) of 0.66 for English-Italian, and a mere 0.187 for Telugu-Kannada. There exist comparable corpora in many Indian languages with other ``auxiliary'' languages. We observe that translations have many topically related words in common in the auxiliary language. To model this, we define the notion of a translingual theme, a set of topically related words from auxiliary language corpora, and present a probabilistic framework for translation induction. Extensive experiments on 35 comparable corpora using English and French as auxiliary languages show that this approach can yield dramatic improvements in performance (e.g. MRR improves by 124% to 0.419 for Telugu-Kannada). A user study on WikiTSu, a system for cross-lingual Wikipedia title suggestion that uses our approach, shows a 20% improvement in the quality of titles suggested.

Design of a manual press for the production of compacted stabilized soil blocks

In this paper, we discuss the design of a manually operated soil compaction machine that is being used to manufacture stabilized soil blocks (SSB). A case study of manufacturing more than three million blocks in a housing project using manually operated machines is illustrated. The paper is focussed on the design, development, and evaluation of a manually operated soil compaction machine for the production of SSB. It also details the machine design philosophy, compaction characteristics of soils, employment generation potential of small-scale stabilized soil block productions systems, and embodied energy. Static compaction of partially saturated soils was performed to generate force-displacement curves in a confined compaction process were generated. Based on the soil compaction data engineering design aspects of a toggle press are illustrated. The results of time and motion study on block production operations using manual machines are discussed. Critical path network diagrams were used for small-scale SSB production systems. Such production systems generate employment at a very low capital cost.

Manual para la cría y reproducción de la lapa roja (Ara macao L.) en condiciones de zoocriadero en Nicaragua

Durante las últimas décadas se han conseguido importantes avances en la cría del Ara macao L. y parte de la razón del incremento en la reproducción son los avances en la nutrición, la estimulacion de nidificación y facilidad de la cría manual de sus polluelos. En la actualidad se ha estado trabajando en la identificación de rasgos de dimorfismo sexual, pero esta especie no posee muchos. El uso de incubadoras se ha popularizado en grado apreciable, y como resultado es posible retirar los huevos poco después de la puesta y proceder a incubación y al cuidado de los polluelos después de nacidos de forma separada. Mientras tanto y durante este proceso, los adultos ya estarán nidificando de nuevo. Este sistema a menudo llamado "doble nidada" estimula el ciclo reproductivo natural de los guacamayos y obviamente permite doblar el número de polluelos en cada época de cría. El uso de registros en el criadero permitirá obtener mejores resultados, para esto se diseñan fichas de registro reproductivo y fichas de registro individual.El aspecto exótico de los guacamayos puede dar la impresión de que son delicados y por ello propensos a enfermar. La mayoría de estos guacamayos exigen cuidados sencillos y gozan de larga vida con tal que se les instale en un entorno limpio y se alimenten de forma balanceada. Hay que someter a estrecha observación todas las aves recién adquiridas, en especial si han sido importadas. El estrés causado por el transporte y por un entorno que no les es familiar, habrá reducido la resistencia del ave a las enfermedades. Aparte de ello, cabe que en su nuevo entorno se encuentre con microorganismos dañinos con los que no se hayan familiarizado y a los cuales son virtualmente inmunes las aves ya instaladas. Al igual que cualquier otro animal, pueden verse aquejados por un número considerable de enfermedades, por cuyo motivo ha de constituir objetivo de todo aquel que disponga de varios ejemplares, reducir, a través de la higiene, la incidencia del riesgo que sobre ellos se cierne y tener plena conciencia de cuales son las situaciones en las que cualquier enfermedad puede propagarse.

Manual de crianza, raza, entrenamiento y reglamento del gallo de combate

Los gallos de combate llegaron a América provenientes de Europa; los conquistadores españoles trajeron gallos del tipo bankivoyde; malayoide, entre otros. Los primeros gallos de combate se originaron hace más de cinco mil años, ascendientes de los que hoy conocemos como Asiles Las primeras peleas de gallo se registraron en la India tres mil años antes de Cristo. Posiblemente las primeras aves que se pelearon por separado, fueron machos nacidos en cautiverio, tanto Malayos (Gallus giganteus)como Bankivas (subespecies de Gallus gallus). Para la selección y formación del "gallo de combate" intervinieron una serie de factores, los cuales se tejieron alrededor de la antigua Bélica de estas aves, de allí vendría el interés por crearlos, teniendo antes que capturarlo y trasladarlo desde su hábitat natural (los bosques) al cautiverio,cuando eran pollitos. Seguramente el primer criador de gallos de combate se daría cuenta de la actitud Bélica conflictiva en los pollones; quienes, al crecer demostrarían sus primeras actitudes de luchadores, matándose unos a otros. Esto forzaría a los criadores a separarlos en pequeñas jaulas rústicas. Luego hicieron la primera selección de los mejores ejemplares, según las actitudes de lucha, fuerza, velocidad, agilidad, entre otras. Antes de empezar con la explicación del manejo de los gallos de pelea, es necesario ejecutar algunas aclaraciones con relación a lo que son los gallos de pelea, y sobre todo, quienes son los que se encargan de su manejo. Cabe entender que, no todas las personas que están en este medio son iguales, y la forma más sencilla de explicar esto, es marcar la diferencia entre "galleros" y "criadores de gallos" Estos últimos, para tener aves de calidad, le es indispensable saber eleccionar a los reproductores, tal vez esta es la tarea más difícil de todas. Fundamentar la base para una buena alimentación, sana y racional. Es muy importante conocer sobre el tema de las instalaciones, para los que quieren iniciar su criadero de aves de combate. Deben tomarse en cuenta, en el manejo del gallo de pelea, las prácticas adecuadas del descreste y tusado. Las enfermedades se reconocen por sus señales muy claras. Las vacunas es el método más sencillo y más barato de prevenir pérdidas. El entrenamiento o cuido apropiado y la buena alimentación del gallo, son esenciales para obtener victorias o buen rendimiento durante el combate, si falta uno de éstos dos, puede ser fatal para sus gallos. Existen distintos tipos de entrenamientos para un gallo de pelea, ninguno es criticable, pero definitivamente es necesario preguntarse ¿Están ganando con este método? En síntesis hay que identificar y evaluar, comenzando desde el lugar en dónde desarrollar nuestras crías, depende mucho de las condiciones climáticas y ambientales(humedad, sol, temperatura, disposición de agua fresca, entre otras). Disponibilidad de materia prima como granos, alimento balanceado, y forraje verde. Disposición de personal calificado en la temática y permanencia continúa.

Discriminative language model adaptation for Mandarin broadcast speech transcription and translation

This paper investigates unsupervised test-time adaptation of language models (LM) using discriminative methods for a Mandarin broadcast speech transcription and translation task. A standard approach to adapt interpolated language models to is to optimize the component weights by minimizing the perplexity on supervision data. This is a widely made approximation for language modeling in automatic speech recognition (ASR) systems. For speech translation tasks, it is unclear whether a strong correlation still exists between perplexity and various forms of error cost functions in recognition and translation stages. The proposed minimum Bayes risk (MBR) based approach provides a flexible framework for unsupervised LM adaptation. It generalizes to a variety of forms of recognition and translation error metrics. LM adaptation is performed at the audio document level using either the character error rate (CER), or translation edit rate (TER) as the cost function. An efficient parameter estimation scheme using the extended Baum-Welch (EBW) algorithm is proposed. Experimental results on a state-of-the-art speech recognition and translation system are presented. The MBR adapted language models gave the best recognition and translation performance and reduced the TER score by up to 0.54% absolute. © 2007 IEEE.