Probing of tertiary interactions in RNA: 2'-hydroxyl-base contacts between the RNase P RNA and pre-tRNA.

A general method has been developed to analyze all 2' hydroxyl groups involved in tertiary interactions in RNA in a single experiment. This method involves comparing the activity of populations of circularly permuted RNAs that contain or lack potential hydrogen-bond donors at each position. The 2' hydroxyls of the pre-tRNA substrate identified as potential hydrogen bond donors in intermolecular interactions with the ribozyme from eubacterial RNase P (P RNA) are located in the T stem and T loop, acceptor stem, and 3' CCA regions. To locate the hydrogen-bond acceptors for one of those 2' hydroxyls in the P RNA, a phylogenetically conserved adenosine was mutated to a guanosine. When this mutant P RNA was used, increased cleavage activity of a single circularly permuted substrate within the population was observed. The cleavage efficiency (kcat/Km) of a singly 2'-deoxy-substituted substrate at this position in the T stem was also determined. For the wild-type P RNA, the catalytic efficiency was significantly decreased compared with that of the all-ribo substrate, consistent with the notion that this 2' hydroxyl plays an important role. For the P RNA mutant, no additional effect was found upon 2'-deoxy substitution. We propose that this particular 2' hydroxyl in the pre-tRNA interacts specifically with this adenosine in the P RNA. This method should be useful in examining the role of 2' hydroxyl groups in other RNA-RNA and RNA-protein complexes.

Tertiary structure of an amyloid immunoglobulin light chain protein: a proposed model for amyloid fibril formation.

An immunoglobulin light chain protein was isolated from the urine of an individual (BRE) with systemic amyloidosis. Complete amino acid sequence of the variable region of the light chain (VL) protein established it as a kappa I, which when compared with other kappa I amyloid associated proteins had unique residues, including Ile-34, Leu-40, and Tyr-71. To study the tertiary structure, BRE VL was expressed in Escherichia coli by using a PCR product amplified from the patient BRE's bone marrow DNA. The PCR product was ligated into pCZ11, a thermal-inducible replication vector. Recombinant BRE VL was isolated, purified to homogeneity, and crystallized by using ammonium sulfate as the precipitant. Two crystal forms were obtained. In crystal form I the BRE VL kappa domain crystallizes as a dimer with unit cell constants isomorphous to previously published kappa protein structures. Comparison with a nonamyloid VL kappa domain from patient REI, identified significant differences in position of residues in the hypervariable segments plus variations in framework region (FR) segments 40-46 (FR2) and 66-67 (FR3). In addition, positional differences can be seen along the two types of local diads, corresponding to the monomer-monomer and dimer-dimer interfaces. From the packing diagram, a model for the amyloid light chain (AL) fibril is proposed based on a pseudohexagonal spiral structure with a rise of approximately the width of two dimers per 360 degree turn. This spiral structure could be consistent with the dimensions of amyloid fibrils as determined by electron microscopy.

Removal of endocrine disrupting compounds from wastewater: a comparison between a conventional activated sludge with tertiary treatment and membrane bioreactors

Póster presentado en 19th International Congress of Chemical and Process Engineering, Prague, Czech Republic August 28th-September 1st, 2010.

Recolonization of mortars by endolithic organisms on the walls of San Roque church in Campeche (Mexico): A case of tertiary bioreceptivity

San Roque church (Campeche, Mexico) was built at the end of the 17th century with a micritic limestone and lime mortar in baroque style. In 2005 the church exhibited heavy biodeterioration associated with the development of extensive dark green phototrophic-based biofilms. Several cyanobacteria belonging to the order Chroococcales and lichenized fungi (Toninia nordlandica, Lobaria quercizans, Lecanora subcarnea, Cystocoleus ebeneus) were predominant in the dark biofilm samples, as revealed by DNA-based molecular techniques. In 2009, a cleaning and restoration intervention was adopted; however, after few months, microbial recolonization started to be noticeable on the painted church walls, representing an early phototrophic-based recolonization. According to molecular analysis, scanning electron microscopy observations and digital image analysis of cross sections, new phototrophic-based colonization, composed of cyanobacteria and bryophytes, developed mainly beneath the restored mortars. The intrinsic properties of the mortars, the tropical climate of Campeche and the absence of a biocide treatment in the restoration protocol influenced the recolonization of the church façades and enhanced the overall rate of deterioration in a short-term period.

Catheter-related bloodstream infection: burden of disease in a tertiary hospital

Background: Surveillance programmes have become the most effective tool for controlling catheter-related bloodstream infections (CRBSI). However, few studies have investigated programmes covering all hospital settings. Aim: To describe the results of a control and prevention programme for CRBSI based on compliance with recommendations for insertion and maintenance, using annual burden of disease in a tertiary level hospital. Methods: A CRBSI control and prevention programme involving all hospital settings was implemented. The programme consisted of CRBSI surveillance, direct observation of insertion and maintenance of catheters to determine performance, and education for healthcare workers. Findings: In total, 2043 short-term catheters were inserted in 1546 patients for 18,570 catheter-days, and 279 long-term catheters were inserted in 243 patients for 40,440 catheter-days. The annual incidence density was 5.98 (first semester 6.40, second semester 5.64) CRBSI per 1000 catheter-days for short-term catheters, and 0.57 (first semester 0.66, second semester 0.43) CRBSI per 1000 catheter-days for long-term catheters. One hundred and forty insertion procedures were observed, with an average insertion time of 13 (standard deviation 7) min. Compliance with recommendations was as follows: hand hygiene, 86.8%; use of alcoholic chlorhexidine solution for skin disinfection, 35.5%; use of mask, 93.4%; use of gloves, 98.7%; use of gown, 75.0%; use of sterile cloth, 93.8%; use of cap, 92.2%; bandage application, 62.7%; and use of aseptic technique, 89.5%. Forty-five maintenance procedures were observed, and compliance rates were as follows: hand hygiene, 42.1%; use of gloves, 78.1%; and port disinfection with alcoholic chlorhexidine solution, 32.5%. Conclusion: The CRBSI control and prevention programme implemented at the study hospital has decreased the rate of CRBSI, provided important information about the total burden of disease, and revealed possible ways to improve interventions in the future.

A proposal for teaching with authentic texts in order to develop social awareness in a language subject in tertiary education

The University of the 21st century has to establish links with society and prepare students for the demands of the working world. Therefore, this article is a contribution to the integral preparation of university students by proposing the use of authentic texts with social content in English lessons so that students acquire emotional and social competencies while still learning content. This article will explain how the choice of texts on global issues such as racism and gender helps students to develop skills such as social awareness and critical thinking to deepen their understanding of discrimination, injustice or gender differences in both oral and written activities. A proposal will be presented which involves using the inauguration speech from Mandela's presidency and texts with photographs of women so that students analyse them whilst utilising linguistic tools that allow them to explore a text's social dimension.

How to Use Cooperative Learning for Assessing Students’ Emotional Competences: A Practical Example at the Tertiary Level

Cooperative learning allows students acquisition of competences that are essential for the labour market such as leadership, critical thinking, communication, and so on. For this reason, different cooperative activities were designed in a language subject in English Studies so that students could work in groups and acquire those competences. This article describes some such activities and the emotional competences that students acquire with them. Moreover, a survey was conducted in order to establish students’ opinions about the main competences they acquired with the activities designed and their opinion about a cooperative methodology. Students’ answers were positive and they were aware of what they had learned.

A primitive pyrothere (Mammalia, Notoungulata) from the early Tertiary of northwestern Venezuela / Bryan Patterson --.

v.33:no.22(1977)

Fossil specimens of Macrochelys from the Tertiary of the plains / Rainer Zangerl --

v.10:no.2(1945)

Design and synthesis of constrained azacyclic pyrrolidine analogues of FTY720 as anticancer agents & metal coordination-controlled and bifunctional catalysis toward tertiary β-Ketols

Cette thèse se compose en deux parties: Première Partie: La conception et la synthèse d’analogues pyrrolidiniques, utilisés comme agents anticancéreux, dérivés du FTY720. FTY720 est actuellement commercialisé comme médicament (GilenyaTM) pour le traitement de la sclérose en plaques rémittente-récurrente. Il agit comme immunosuppresseur en raison de son effet sur les récepteurs de la sphingosine-1-phosphate. A fortes doses, FTY720 présente un effet antinéoplasique. Cependant, à de telles doses, un des effets secondaires observé est la bradycardie dû à l’activation des récepteurs S1P1 et S1P3. Ceci limite son potentiel d’utilisation lors de chimiothérapie. Nos précédentes études ont montré que des analogues pyrrolidiniques dérivés du FTY720 présentaient une activité anticancéreuse mais aucune sur les récepteurs S1P1 et S1P3. Nous avons soumis l’idée qu’une étude relation structure-activité (SARs) pourrait nous conduire à la découverte de nouveaux agents anti tumoraux. Ainsi, deux séries de composés pyrrolidiniques (O-arylmethyl substitué et C-arylmethyl substitué) ont pu être envisagés et synthétisés (Chapitre 1). Ces analogues ont montré d’excellentes activités cytotoxiques contre diverses cellules cancéreuses humaines (prostate, colon, sein, pancréas et leucémie), plus particulièrement les analogues actifs qui ne peuvent pas être phosphorylés par SphK, présentent un plus grand potentiel pour le traitement du cancer sans effet secondaire comme la bradycardie. Les études mécanistiques suggèrent que ces analogues de déclencheurs de régulation négative sur les transporteurs de nutriments induisent une crise bioénergétique en affamant les cellules cancéreuses. Afin d’approfondir nos connaissances sur les récepteurs cibles, nous avons conçu et synthétisé des sondes diazirine basées sur le marquage d’affinité aux photons (méthode PAL: Photo-Affinity Labeling) (Chapitre 2). En s’appuyant sur la méthode PAL, il est possible de récolter des informations sur les récepteurs cibles à travers l’analyse LC/MS/MS de la protéine. Ces tests sont en cours et les résultats sont prometteurs. Deuxième partie: Coordination métallique et catalyse di fonctionnelle de dérivés β-hydroxy cétones tertiaires. Les réactions de Barbier et de Grignard sont des méthodes classiques pour former des liaisons carbone-carbone, et généralement utilisées pour la préparation d’alcools secondaires et tertiaires. En vue d’améliorer la réaction de Grignard avec le 1-iodobutane dans les conditions « one-pot » de Barbier, nous avons obtenu comme produit majoritaire la β-hydroxy cétone provenant de l’auto aldolisation de la 5-hexen-2-one, plutôt que le produit attendu d’addition de l’alcool (Chapitre 3). La formation inattendue de la β-hydroxy cétone a également été observée en utilisant d’autres dérivés méthyl cétone. Étonnement dans la réaction intramoléculaire d’une tricétone, connue pour former la cétone Hajos-Parrish, le produit majoritaire est rarement la β-hydroxy cétone présentant la fonction alcool en position axiale. Intrigué par ces résultats et après l’étude systématique des conditions de réaction, nous avons développé deux nouvelles méthodes à travers la synthèse sélective et catalytique de β-hydroxy cétones spécifiques par cyclisation intramoléculaire avec des rendements élevés (Chapitre 4). La réaction peut être catalysée soit par une base adaptée et du bromure de lithium comme additif en passant par un état de transition coordonné au lithium, ou bien soit à l’aide d’un catalyseur TBD di fonctionnel, via un état de transition médiée par une coordination bidenté au TBD. Les mécanismes proposés ont été corroborés par calcul DFT. Ces réactions catalytiques ont également été appliquées à d’autres substrats comme les tricétones et les dicétones. Bien que les efforts préliminaires afin d’obtenir une enantioselectivité se sont révélés sans succès, la synthèse et la recherche de nouveaux catalyseurs chiraux sont en cours.

How returns from tertiary education differ by field of study. Implications for policy-makers and students. CEPS Working Document No. 411/July 2015

With the huge growth in enrolment in higher education, the key question facing young people today is not so much “what to study” as “whether to study”. Taking a methodologically innovative approach, this paper measures the net present value of university education and compares returns from studying a range of different subjects. We use data from 5 European countries (France, Italy, Hungary, Poland and Slovenia) and include (opportunity) costs in the computation. Results suggest that enrolling in science, technology, engineering and mathematics (STEM) courses is often not the best investment for students, especially female students. In choosing what to study, therefore, students are taking decisions that are consistent with their own private returns. This suggests that policymakers should consider changing the incentives offered if they wish to change students’ behaviour.