Centromeres under pressure: Evolutionary innovation in conflict with conserved function

Centromeres are essential genetic elements that enable spindle microtubule attachment for chromosome segregation during mitosis and meiosis. While this function is preserved across species, centromeres display an array of dynamic features, including: (1) rapidly evolving DNA; (2) wide evolutionary diversity in size, shape and organization; (3) evidence of mutational processes to generate homogenized repetitive arrays that characterize centromeres in several species; (4) tolerance to changes in position, as in the case of neocentromeres; and (5) intrinsic fragility derived by sequence composition and secondary DNA structures. Centromere drive underlies rapid centromere DNA evolution due to the “selfish” pursuit to bias meiotic transmission and promote the propagation of stronger centromeres. Yet, the origins of other dynamic features of centromeres remain unclear. Here, we review our current understanding of centromere evolution and plasticity. We also detail the mutagenic processes proposed to shape the divergent genetic nature of centromeres. Changes to centromeres are not simply evolutionary relics, but ongoing shifts that on one side promote centromere flexibility, but on the other can undermine centromere integrity and function with potential pathological implications such as genome instability

Evaluating the Effectiveness of Video-Based Education of Venous Gas Embolism for Nurse Anesthesia Trainees

Background/Significance: Video-based learning is a growing method being utilized to train nurse anesthesia trainees (NATs) in crisis management, such as a venous gas embolism (VGE). Use of this educational modality may improve crisis management skills, competence, and confidence in the NAT. Purpose: The purpose of this project was to evaluate the effectiveness of an educational video in enhancing the appropriate crisis management of VGE among NATs as measured by their knowledge and confidence levels. Methods: A quasi-experimental pretest-posttest design on a single group of participants was utilized for this project. A total of 14 first year NATs were recruited from NorthShore University HealthSystems School of Nurse Anesthesia (NSUHS) and participated in this study. An instructional video that simulates the proper management of VGE, a knowledge assessment tool (KAT) to assess non-technical skills knowledge pertaining to VGE, and a student confidence survey were developed for implementation of this study. Results: A Wilcoxon Signed Matched-Pairs Ranks Test demonstrated that the median post-test scores were statistically higher that the median pre-test scores between pre and post-instructional video [Z= -3.301; p=0.001 (2- tailed)]. The knowledge questionnaire had an adequate post-test Kuder-Richardson-20 (KR-20) coefficient value =0.678. Conclusion: NATs that participated in the study gained knowledge and confidence from pre and post video implementation. The mean scores improved in every knowledge category (prevention, recognition, decision-making, and prioritization) and confidence category (identification, management, and learning crisis management). Key Words: video-education, venous gas embolism, teaching-methods, crisis management, confidence levels, nurse anesthesia trainees, non-technical skill

Improvements in Production of Single-Walled Carbon Nanotubes

A continuing program of research and development has been directed toward improvement of a prior batch process in which single-walled carbon nanotubes are formed by catalytic disproportionation of carbon monoxide in a fluidized-bed reactor. The overall effect of the improvements has been to make progress toward converting the process from a batch mode to a continuous mode and to scaling of production to larger quantities. Efforts have also been made to optimize associated purification and dispersion post processes to make them effective at large scales and to investigate means of incorporating the purified products into composite materials. The ultimate purpose of the program is to enable the production of high-quality single-walled carbon nanotubes in quantities large enough and at costs low enough to foster the further development of practical applications. The fluidized bed used in this process contains mixed-metal catalyst particles. The choice of the catalyst and the operating conditions is such that the yield of single-walled carbon nanotubes, relative to all forms of carbon (including carbon fibers, multi-walled carbon nanotubes, and graphite) produced in the disproportionation reaction is more than 90 weight percent. After the reaction, the nanotubes are dispersed in various solvents in preparation for end use, which typically involves blending into a plastic, ceramic, or other matrix to form a composite material. Notwithstanding the batch nature of the unmodified prior fluidized-bed process, the fluidized-bed reactor operates in a continuous mode during the process. The operation is almost entirely automated, utilizing mass flow controllers, a control computer running software specific to the process, and other equipment. Moreover, an important inherent advantage of fluidized- bed reactors in general is that solid particles can be added to and removed from fluidized beds during operation. For these reasons, the process and equipment were amenable to modification for conversion from batch to continuous production

Strategies to optimize the use of marginal donors in liver transplantation.

Liver transplantation is the treatment of choice for end stage liver disease, but availability of liver grafts is still the main limitation to its wider use. Extended criteria donors (ECD) are considered not ideal for several reasons but their use has dramatically grown in the last decades in order to augment the donor liver pool. Due to improvement in surgical and medical strategies, results using grafts from these donors have become acceptable in terms of survival and complications; nevertheless a big debate still exists regarding their selection, discharge criteria and allocation policies. Many studies analyzed the use of these grafts from many points of view producing different or contradictory results so that accepted guidelines do not exist and the use of these grafts is still related to non-standardized policies changing from center to center. The aim of this review is to analyze every step of the donation-transplantation process emphasizing all those strategies, both clinical and experimental, that can optimize results using ECD

P02-203 Representation of HIV/Aids and mental health co-morbidity in medical and social sciences literature

Introduction:Aim of this article is to explore the ways in which, over the last 25 years, knowledge about HIV/Aids and Mental Health co-morbidity has been represented within medical and social sciences literature.Methods:The study has been conducted on the texts of 1101 published manuscripts abstracts within from 1984 to 2008, referring to 379 different journals and retrieved on PUBMED database. It was used the following database search string: ("mental health"[Title/Abstract]) or ("mental illness"[Title/Abstract]) AND (("aids"[Title/Abstract]) or ("hiv"[Title/Abstract]))). A Computer Aided Text Analysis was conducted with dedicated software: T-Lab (Lancia) using Cluster Analysis.Results:Cluster Analysis allowed to identify five different main dimensions: 1:(27,68%) Health-care Service organizational development; 2: (22,10%) Mental health as empowering precursor of infection risks. 3: (8,58%) Quality of life; 4: (19,17%). Therapies and treatments' research; 5: (22,46%) Psychological issues, emotions and distress correlated to seropositive patients and their caregivers. Figure 1 it is a way to outline the five clusters literature trends over the time of 25 years.Conclusions:Our review could help to identify particular areas in need of change, to provide a baseline against which to assess future changes and to provide data for use in research health planning and policy analysis

Nanotecnología : diagnóstico para la brucelosis porcina

Porcine brucellosis is an important zoonosis to public health and to agricultural economy since it causes significant losses in production, and the establishment of sanitary restrictions on local and international trade. Therefore, it is important to have a rapid and reliable diagnosis. To date, confirmatory diagnosis of brucellosis mainly relies on the isolation of the bacterium, but it is difficult to implement. Currently, most of the diagnostic tests are based on serological assays useful for diagnosing herds; however there is still not an accurate diagnosis to test individual animals. Thus, in the present work we developed and evaluated a novel indirect immunoassay (iELISA) using a recombinant glycoprotein antigen formed by the LPS O: 9-O polysaccharide of Yersinia enterocolitica (identical to the O polysaccharide of B. suis) covalently coupled to the carrier protein AcrA, derived from Campylobacter jejuni. This antigen was previously characterized and validated for the diagnosis of brucellosis in humans and cattle. From the above mentioned antigen we have developed and validated the glyco-iELISA using a panel of positive and negative sera previously characterized by agglutination buffered plate antigen techniques (BPA), and by fluorescent polarization assay (FPA). The results indicate that the glyco-iELISA differentiates positive animals from clearly negative ones. A cut-off value of 0.56 resulted in a diagnostic test sensitivity and specificity of 100 %, respectively. In addition, as a proof of concept we set to develop, with a small panel of sera, an indirect fluorescence immunoassay with OAg-AcrA coupled to magnetic beads. Due to the advantage of using magnetic racks instead of centrifugation, reduced incubation time and more efficient washes, this platform has shown to be a valuable practical diagnostic tool. Both developed assays discriminate positive from negative animals, even in infected herds specifically identifying the infected animal and differentiating it from negative animals exposed.\nFil: Balzano Parodi, Rodrigo E. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaLa brucelosis porcina es una zoonosis de importancia para la salud pública y la economía agropecuaria, ya que provoca importantes pérdidas en la producción y restricciones sanitarias en el comercio interno y en las exportaciones. Por ello, es importante tener un diagnóstico rápido y confiable. Hasta la fecha, la prueba confirmatoria de brucelosis es el aislamiento de la bacteria, lo cual es difícil de implementar. Los test diagnósticos vigentes se basan en pruebas serológicas que son útiles para el diagnóstico de piaras pero no permiten obtener un diagnóstico fiable de los animales a nivel individual. Por esta razón, en este trabajo se desarrolló y evaluó un nuevo test diagnóstico. El mismo consiste en un inmunoensayo (iELISA) utilizando como antígeno una glicoproteína recombinante, la cual está formada por el polisacárido O del LPS de Yersinia enterocolitica O:9 (idéntico al polisacárido O de B. suis) unido covalentemente a la proteína transportadora AcrA derivada de Campylobacter jejuni. Este antígeno fue previamente caracterizado y validado para el diagnóstico de brucelosis en humanos y bovinos. A partir del mismo, se desarrolló y validó el glico-iELISA utilizando un panel de sueros positivos y negativos previamente caracterizados por las técnicas de aglutinación con antígeno bufferado en placa (BPA) y Ensayo de Polarización Fluorescente (FPA). Los resultados indican que el glico-iELISA permite discriminar claramente animales positivos de negativos, con un valor de cut-off de 0,56, resultando en una sensibilidad y especificidad diagnóstica de 100%. Además, se desarrolló como prueba de concepto, un inmunoensayo de fluorescencia basado en la unión covalente del mencionado antígeno a micropartículas magnéticas con un panel reducido de sueros. Esta plataforma presenta las ventajas de reducir los tiempos de incubación y los lavados son más eficientes utilizando racks magnéticos sin necesidad de centrifugar, entre otras. Ambos ensayos desarrollados permitieron discriminar animales positivos de negativos, incluso en piaras infectadas identificando puntualmente al animal infectado y diferenciándolo de los animales negativos expuestos

Scratching the scale labyrinth

In this paper, we introduce a new approach to computer-aided microtonal improvisation by combining methods for (1) interactive scale navigation, (2) real-time manipulation of musical patterns and (3) dynamical timbre adaption in solidarity with the respective scales. On the basis of the theory of well-formed scales we offer a visualization of the underlying combinatorial ramifications in terms of a scale labyrinth. This involves the selection of generic well-formed scales on a binary tree (based on the Stern-Brocot tree) as well as the choice of specific tunings through the specification of the sizes of a period (pseudo-octave) and a generator (pseudo-fifth), whose limits are constrained by the actual position on the tree. We also introduce a method to enable transformations among the modes of a chosen scale (generalized and refined “diatonic” and “chromatic” transpositions). To actually explore the scales and modes through the shaping and transformation of rhythmically and melodically interesting tone patterns, we propose a playing technique called Fourier Scratching. It is based on the manipulation of the “spectra” (DFT) of playing gestures on a sphere. The coordinates of these gestures affect score and performance parameters such as scale degree, loudness, and timbre. Finally, we discuss a technique to dynamically match the timbre to the selected scale tuning

P02-178 HIV/Aids and mental illness dual diagnosis: Exploring healthcare professionals' perspective

Aims:A growing body of scientific literature emphasizes a strong linkage between HIV/Aids and serious mental illness. In the Italian context, specialized services for combined management of dual diagnosis are increasingly requested, and healthcare professionals (HPWs) have to face up the difficulty emerging by this new situation. To bridge these gaps, the present study aimed at studying the representations of dual diagnosis, analyzing HPWs' experiences from their own perspectives, in order to understand their difficulty and create future good practices in healthcare services.Method:A quali-quantitative study was conducted with a multidisciplinary sample of professionals (N=91), drawn by HIV/Aids and Mental Health sites. Due to the exploratory nature of the research, data were collected from semi-structured interviews: HPWs were asked about their work experiences with HIV/Aids and Mental Illness. The interviews were fully audio-taped and verbatim transcribed. A computer-aided lexical correspondence analysis was conducted by a dedicated text-analysis software.Results:Data analysis showed out two main factorial dimensions: the first regarding the representation of the "Management of dual diagnosis within Health Services", and the second one referring to the "categorization of HIV/Aids-Mental Illness co-morbidity". Furthermore, four different Representational Conceptions were highlighted, corresponding to as many different ways HPWs use to represent/depict the aims of Health Service in relation to HIV/Aids-Mental Illness co-morbidity.Conclusion:This study reveals that socio-cultural meanings of dual diagnosis are not fixed; rather, they are ongoing co-constructed within the activities carried out by the HPWs involved in their specific health contexts in the exercise of their profession

A bacterial glycoengineered antigen for improved serodiagnosis of porcine brucellosis

Brucellosis is a highly zoonotic disease that affects animals and human beings. Brucella suis is the etiological agent of porcine brucellosis and one of the major human brucellosis pathogens. Laboratory diagnosis of porcine brucellosis mainly relies on serological tests, and it has been widely demonstrated that serological assays based on the detection of anti O-polysaccharide antibodies are the most sensitive tests. Here, we validate a recombinant glycoprotein antigen, an N-formylperosamine O-polysaccharide protein conjugate (OAg-AcrA), for diagnosis of porcine brucellosis. An indirect immunoassay based on the detection of anti-O-polysaccharide IgG antibodies was developed coupling OAg-AcrA to enzyme-linked immunosorbent assay plates (glycoiELISA). To validate the assay, 563 serum samples obtained from experimentally infected and immunized pigs, as well as animals naturally infected with B. suis biovar 1 or 2, were tested. A receiver operating characteristic (ROC) analysis was performed, and based on this analysis, the optimum cutoff value was 0.56 (relative reactivity), which resulted in a diagnostic sensitivity and specificity of 100% and 99.7%, respectively. A cutoff value of 0.78 resulted in a test sensitivity of 98.4% and a test specificity of 100%. Overall, our results demonstrate that the glyco-iELISA is highly accurate for diagnosis of porcine brucellosis, improving the diagnostic performance of current serological tests. The recombinant glycoprotein OAg-AcrA can be produced in large homogeneous batches in a standardized way, making it an ideal candidate for further validation as a universal antigen for diagnosis of "smooth" brucellosis in animals and humans.Fil: Cortina, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Balzano, Rodrigo E.. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Rey Serantes, Diego A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Caillava, Ana Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Elena, Sebastian. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Ferreira, A. C.. Instituto Nacional de Investigação Agrária e Veterinária; PortugalFil: Nicola, Ana M.. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Ugalde, Juan Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; ArgentinaFil: Comerci, Diego José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Ciocchini, Andres Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas ; Argentin

An intuitive introduction to the evolution of physical systems

We outline a unified introduction to the general problem of dynamics intended for a high-school students audience. The attempt consists in circumventing the lack of mathematical knowledge with the use of 1) geometric diagrams, 2) a discretized version of the equations of motion and 3) a simplified form of computation and analysis of their solutions. The aim is to allow students to approach theoretical features as well as computational aspects of the evolution equations through the use of spreadsheets, a work environment students are usually familiar with and an ideal tool for an intuitive approach to recursive algorithms. The proposal was presented to an audience composed of students of University courses of Physics teaching and to high-school Science teachers