The "DEAD box" protein DbpA interacts specifically with the peptidyltransferase center in 23S rRNA.

The Escherichia coli DEAD (Asp-Glu-Ala-Asp) box protein DbpA is a putative RNA helicase and established RNA-dependent ATPase and is the only member of the DEAD box protein family for which a specific RNA substrate, bacterial 23S rRNA, has been identified. We have investigated the nature of this specificity in depth and have localized by deletion mutagenesis and PCR a single region of 93 bases (bases 2496-2588) in 23S rRNA that is both necessary and sufficient for complete activation of ATPase activity of DbpA. This target region forms part of the peptidyltransferase center and includes many bases involved in interaction with the 3' terminal adenosines of both A- and P-site tRNAs. Deletion of stem loops within the 93-base segment abolished ATPase activation. Similarly, point mutations that disrupt base pairing within stem structures ablated stimulation of ATPase activity. These data are consistent with roles for DbpA either in establishing and/or maintaining the correct three-dimensional structure of the peptidyltransferase center in 23S rRNA during ribosome assembly or in the peptidyltransferase reaction.

GAIP, a protein that specifically interacts with the trimeric G protein G alpha i3, is a member of a protein family with a highly conserved core domain.

Using the yeast two-hybrid system we have identified a human protein, GAIP (G Alpha Interacting Protein), that specifically interacts with the heterotrimeric GTP-binding protein G alpha i3. Interaction was verified by specific binding of in vitro-translated G alpha i3 with a GAIP-glutathione S-transferase fusion protein. GAIP is a small protein (217 amino acids, 24 kDa) that contains two potential phosphorylation sites for protein kinase C and seven for casein kinase 2. GAIP shows high homology to two previously identified human proteins, GOS8 and 1R20, two Caenorhabditis elegans proteins, CO5B5.7 and C29H12.3, and the FLBA gene product in Aspergillus nidulans--all of unknown function. Significant homology was also found to the SST2 gene product in Saccharomyces cerevisiae that is known to interact with a yeast G alpha subunit (Gpa1). A highly conserved core domain of 125 amino acids characterizes this family of proteins. Analysis of deletion mutants demonstrated that the core domain is the site of GAIP's interaction with G alpha i3. GAIP is likely to be an early inducible phosphoprotein, as its cDNA contains the TTTTGT sequence characteristic of early response genes in its 3'-untranslated region. By Northern analysis GAIP's 1.6-kb mRNA is most abundant in lung, heart, placenta, and liver and is very low in brain, skeletal muscle, pancreas, and kidney. GAIP appears to interact exclusively with G alpha i3, as it did not interact with G alpha i2 and G alpha q. The fact that GAIP and Sst2 interact with G alpha subunits and share a common domain suggests that other members of the GAIP family also interact with G alpha subunits through the 125-amino-acid core domain.

Expression of lactoferrin receptors is increased in the mesencephalon of patients with Parkinson disease.

The degeneration of nigral dopaminergic neurons in Parkinson disease is believed to be associated with oxidative stress. Since iron levels are increased in the substantia nigra of parkinsonian patients and this metal catalyzes the formation of free radicals, it may be involved in the mechanisms of nerve cell death. The cause of nigral iron increase is not understood. Iron acquisition by neurons may occur from iron-transferrin complexes with a direct interaction with specific membrane receptors, but recent results have shown a low density of transferrin receptors in the substantia nigra. To investigate whether neuronal death in Parkinson disease may be associated with changes in a pathway supplementary to that of transferrin, lactoferrin (lactotransferrin) receptor expression was studied in the mesencephalon. In this report we present evidence from immunohistochemical staining of postmortem human brain tissue that lactoferrin receptors are localized on neurons (perikarya, dendrites, axons), cerebral microvasculature, and, in some cases, glial cells. In parkinsonian patients, lactoferrin receptor immunoreactivity on neurons and microvessels was increased and more pronounced in those regions of the mesencephalon where the loss of dopaminergic neurons is severe. Moreover, in the substantia nigra, the intensity of immunoreactivity on neurons and microvessels was higher for patients with higher nigral dopaminergic loss. These data suggest that lactoferrin receptors on vulnerable neurons may increase intraneuronal iron levels and contribute to the degeneration of nigral dopaminergic neurons in Parkinson disease.

Diminished degradation of yeast cytochrome c by interactions with its physiological partners.

The level and structure of yeast iso-1-cytochrome c and iso-2-cytochrome c, encoded by the nuclear genes CYC1 and CYC7, respectively, are normally not altered in rho- mutants, which completely lack the cytochromes a.a3 subunits and cytochrome b that are encoded by mitochondrial DNA. In contrast, iso-cytochromes c containing the amino acid change Thr-78-->Ile (T78I) were observed at the normal or near-normal wild-type level in rho+ strains but were completely absent in rho- mutants. We have demonstrated with the "global" suppressor mutation Asn-52-->Ile and by pulse-chase labeling that the T78I iso-1-cytochrome c undergoes rapid cellular degradation in rho- mutants. Furthermore, specific mutations revealed that the deficiency of T78I iso-1 cytochrome c can be caused by the lack of cytochrome a.a3 or cytochrome c1, but not by the lack of cytochrome b. Thus, this and certain other, but not all, labile forms of cytochrome c are protected from degradation by the interaction with its physiological partners.

Mast cells express a peripheral cannabinoid receptor with differential sensitivity to anandamide and palmitoylethanolamide.

Mast cells are multifunctional bone marrow-derived cells found in mucosal and connective tissues and in the nervous system, where they play important roles in tissue inflammation and in neuroimmune interactions. Very little is known about endogenous molecules and mechanisms capable of modulating mast cell activation. Palmitoylethanolamide, found in peripheral tissues, has been proposed to behave as a local autacoid capable of downregulating mast cell activation and inflammation. A cognate N-acylamide, anandamide, the ethanolamide of arachidonic acid, occurs in brain and is a candidate endogenous agonist for the central cannabinoid receptor (CB1). As a second cannabinoid receptor (CB2) has been found in peripheral tissues, the possible presence of CB2 receptors on mast cells and their interaction with N-acylamides was investigated. Here we report that mast cells express both the gene and a functional CB2 receptor protein with negative regulatory effects on mast cell activation. Although both palmitoylethanolamide and anandamide bind to the CB2 receptor, only the former downmodulates mast cell activation in vitro. Further, the functional effect of palmitoylethanolamide, as well as that of the active cannabinoids, was efficiently antagonized by anandamide. The results suggest that (i) peripheral cannabinoid CB2 receptors control, upon agonist binding, mast cell activation and therefore inflammation; (ii) palmitoylethanolamide, unlike anandamide, behaves as an endogenous agonist for the CB2 receptor on mast cells; (iii) modulatory activities on mast cells exerted by the naturally occurring molecule strengthen a proposed autacoid local inflammation antagonism (ALIA) mechanism; and (iv) palmitoylethanolamide and its derivatives may provide antiinflammatory therapeutic strategies specifically targeted to mast cells ("ALIAmides").

Asperger's Disorder in College Students: Application of Acceptance and Commitment Therapy

College students with Asperger's Disorder (AD) are likely to face significant challenges as they encounter the unpredictable and socially demanding environment of their university setting. Acceptance and Commitment Therapy (ACT) can be a valuable approach to addressing many of these struggles. This paper will explore the application of ACT to problems that are commonly associated with individuals diagnosed with AD. Utilizing ACT and the Hexaflex Model as a guide for working with AD students can assist in establishing a greater understanding and acceptance of their unique internal experience, as well as their interaction with the external world. ACT can offer these students the ability to be more present in the moment, to recognize efforts to avoid negative experiences, and to move in directions in life that are personally meaningful.

The Impact of Prefrontal Cortex "Warm Up" on Immediate Cognitive Reappraisal Ability in Older Adolescents with Elevated Symptoms of Depression

Cognitive Reappraisal (CR) is a central component of Cognitive Behavioral Therapy for adolescent depression. Yet, previous research indicates that a brain region highly associated with successful CR in adults, the Prefrontal Cortex (PFC), is not fully developed until early adulthood. Thus, there is growing concern that CBT interventions directed at building CR abilities in depressed teens might be constrained by PFC immaturity. However, CR is an effective strategy for regulating affect. The current study evaluated an intervention aimed at enhancing CR performance through PFC “warm up” with a working memory task. Additionally, the study examined moderators of intervention response, as well as cognitive correlates of self-reported CR use. Participants included 48 older adolescents (mean age=19.1, 89% female) with elevated symptoms of depression who were randomly assigned to a lab-based WM or control activity followed by a CR task. Overall, results failed to support the effectiveness of “warm up” to augment CR performance. However, current level of depression predicted negative bias and sadness ratings after CR instructions, and this effect was qualified by an interaction with condition. The moderator analysis showed that depressive symptoms interacted with condition such that in the control condition, participants with higher depressive symptoms had significantly lower negative bias scores than individuals with lower depressive symptoms, but this pattern was not found in the experimental condition. Contrary to hypotheses, history of depression did not moderate treatment response. Additional analyses explored alternative explanations for the lack of intervention effects. There was some evidence to suggest that the WM task was frustrating and cognitively taxing. However, irritation scores and overall WM task accuracy did not predict subsequent CR performance. Lastly, multiple cognitive variables emerged as correlates of self-reported CR use, with cognitive flexibility contributing unique variance to self-reported CR use. Results pointed to new directions for improving CR performance among youth with elevated symptoms of depression.

Experiences with free and open courses using on-line multimedia resources

This paper analyzes the learning experiences and opinions obtained from a group of undergraduate students in their interaction with several on-line multimedia resources included in a free on-line course about Computer Networks. These new educational resources employed are based on the Web2.0 approach such as blogs, videos and virtual labs which have been added in a web-site for distance self-learning.

Herramientas Web en el proceso de enseñanza y aprendizaje del ciberperiodismo en la Comunidad Valenciana

Internet es un recurso de trabajo imprescindible en la tarea del ciberperiodista. Los profesionales de este campo utilizan la red como fuente de información, para crear, editar y distribuir contenidos informativos. Estas nuevas formas de trabajo, apoyadas en entornos telemáticos, se están haciendo extensibles a la universidad española, donde se está produciendo un proceso de adaptación de metodologías, técnicas y herramientas en los estudios de Periodismo. Para facilitar este proceso de ajuste por parte de los profesores de ciberperiodismo, esta investigación pretende establecer una tipología del uso de estos instrumentos en línea según los objetivos planteados en las guías docentes. Para ello, se han estudiado los programas de las asignaturas relacionadas con la docencia del ciberperiodismo en la Comunidad Valenciana. Se han seleccionado los instrumentos Web más utilizados por los profesores y se han organizado en una tabla según criterios de finalidad, acción y tipo de interacción que realiza el alumno con las herramientas y asimismo los objetivos ciberperiodísticos que pueden lograrse con cada una de ellas. La tabla ofrece información general de cada herramienta. El propósito es facilitar a los profesores un criterio de selección para elegir y profundizar en los espacios e instrumentos docentes más adecuados según las competencias que el alumno debe adquirir durante el proceso de enseñanza y aprendizaje en estos estudios.

An exercises editor for an e-learning environment

One of the most important tenets of e-learning is that it bridges work and learning. A great e-learning experience brings learning into the work environment. This is a key point, the capacity to construct a work environment when the student can develop proper tasks to complete the learning process. This paper describes a work environment based on the development of two tools, an exercises editor and an exercises viewer. Both tools are able to manage color images where, because of the implementation of basic steganographic techniques, it is possible to add information, exercises, questions, and so on. The exercises editor allows to decide which information must be visible or remain hidden to the user, when the image is loaded in the exercises viewer. Therefore, it is possible to hide the solutions of the proposed tasks; this is very useful to complete a self-evaluation learning process. These tools constitute a learning architecture with the final objective that learners can apply and practice new concepts or skills.

Entornos virtuales: predicción de la satisfacción en contexto universitario

El presente estudio persigue un doble objetivo: evaluar el grado de satisfacción de los estudiantes con la formación recibida en un entorno virtual y, analizar su capacidad predictiva sobre la satisfacción. Se ha utilizado la versión española del cuestionario Distance Education Learning Environments Survey (Sp-DELES). Los resultados ponen de manifiesto el significativo nivel de satisfacción de los estudiantes con la experiencia y revelan las variables más importantes a la hora de explicar la varianza en satisfacción.

Simultaneous synthesis of work exchange networks with heat integration

The optimal integration of work and its interaction with heat can represent large energy savings in industrial plants. This paper introduces a new optimization model for the simultaneous synthesis of work exchange networks (WENs), with heat integration for the optimal pressure recovery of process gaseous streams. The proposed approach for the WEN synthesis is analogous to the well-known problem of synthesis of heat exchanger networks (HENs). Thus, there is work exchange between high-pressure (HP) and low-pressure (LP) streams, achieved by pressure manipulation equipment running on common axes. The model allows the use of several units of single-shaft-turbine-compressor (SSTC), as well as stand-alone compressors, turbines and valves. Helper motors and generators are used to respond to any demand and excess of energy. Moreover, between the WEN stages the streams are sent to the HEN to promote thermal recovery, aiming to enhance the work integration. A multi-stage superstructure is proposed to represent the process. The WEN superstructure is optimized in a mixed-integer nonlinear programming (MINLP) formulation and solved with the GAMS software, with the goal of minimizing the total annualized cost. Three examples are conducted to verify the accuracy of the proposed method. In all case studies, the heat integration between WEN stages is essential to improve the pressure recovery, and to reduce the total costs involved in the process.

Modification of Hematite Electronic Properties with Trimethyl Aluminum to Enhance the Efficiency of Photoelectrodes

The electronic properties of hematite were investigated by means of synchrotron radiation photoemission (SR-PES) and X-ray absorption spectroscopy (XAS). Hematite samples were exposed to trimethyl aluminum (TMA) pulses, a widely used Al-precursor for the atomic layer deposition (ALD) of Al2O3. SR-PES and XAS showed that the electronic properties of hematite were modified by the interaction with TMA. In particular, the hybridization of O 2p states with Fe 3d and Fe 4s4p changed upon TMA pulses due to electron inclusion as polarons. The change of hybridization correlates with an enhancement of the photocurrent density due to water oxidation for the hematite electrodes. Such an enhancement has been associated with an improvement in charge carrier transport. Our findings open new perspectives for the understanding and utilization of electrode modifications by very thin ALD films and show that the interactions between metal precursors and substrates seem to be important factors in defining their electronic and photoelectrocatalytic properties.

Validation of a Spanish version of the Distance Education Learning Environments Survey (DELES) in Spain

The aim of this study was to examine the validity of the Spanish version of the Distance Education Learning Environments Survey (Sp-DELES). This instrument assesses students’ perceptions of virtual learning environments using six scales: Instructor Support, Student Interaction and Collaboration, Personal Relevance, Authentic Learning, Active Learning, and Autonomy. Further, the Sp-DELES includes an additional scale that assesses students’ Satisfaction with their classes. The original DELES has been used in at least 27 independent studies with strong reliability and validity. For this study, we sampled 265 students from the University of Alicante enrolled in various hybrid and distance education courses taught by the Department of Health Psychology. We analysed the Sp-DELES for validity using principal component factor analysis with varimax rotation, and for reliability using Cronbach’s alpha. The Sp-DELES exhibited good reliability (Cronbach’s alpha for the scales ranging from 0.86 to 0.97) and the original six-factor structure was replicated and accounted for 72.9 % of the total variance. Overall the results are consistent with those of the original English-language version of the instrument. The Sp-DELES has proven to be a reliable and valid instrument for assessing psychosocial learning environments in tertiary-level hybrid and distance-education settings.

Applied Research Sport Experiences, Milestones, and Educational Activities Associated With High-Performance Coaches' Development

What experiences are needed to become a high-performance coach? The present study addressed this question through structured retrospective quantitative interviews with 10 team- and 9 individual-sport coaches at the Canadian interuniversity-sport level. Minimum amounts of certain experiences were deemed necessary but not sufficient to become a high-performance coach (e.g., playing the sport they now coach and interaction with a mentor coach for all coaches, leadership opportunities as athletes for team-sport coaches only). Although coaches reported varying amounts of these necessary experiences, general stages of high-performance coach development were traced. Findings serve to identify and support potential high-performance coaches and increase the effectiveness of formal coaching-education programs.