Measurements of the Isotopic Ratio 6Li/7Li in Stars with Planets

High-resolution (R = 143,000), high signal-to-noise (S/N = 700-1100) Gemini-S bHROS spectra have been analyzed in a search for 6Li in 5 stars which host extrasolar planets. The presence of detectable amounts of 6Li in these mature, solar-type stars is a good monitor of accretion of planetary disk material, or solid bodies themselves, into the outer layers of the parent stars. Detailed profile-fitting of the Li I resonance doublet at lambda 6707.8 A reveals no detectable amounts of 6Li in any star in our sample. The list of stars analyzed includes HD 82943 for which 6Li has been previouly detected at the level of 6Li/7Li = 0.05 +/- 0.02. The typical limits in the derived isotopic fraction are 6Li/7Li <= 0.00-0.02. These upper limits constrain the amount of accreted material to less than ~ 0.02 to 0.5 Jovian masses. The presence of detectable amounts of 6Li would manifest itself as a red asymmetry in the Li I line-profile and the derived upper limits on such asymmetries are discussed in light of three-dimensional hydrodynamic model atmospheres, where convective motions also give rise to slight red asymmetries in line profiles.Comment: 33 pages, 7 figures, 6 tables, accepted for publication in Ap

Bronchial airway anastomotic complications after pediatric lung transplantation: Incidence, cause, management, and outcome

ObjectiveAirway complications are a recognized surgical complication and an important source of morbidity after adult lung transplantation. Little is known about these complications after pediatric lung transplantation.MethodsData of pediatric lung transplants performed between January 1990 and December 2002 in a single pediatric institution were reviewed retrospectively.ResultsA total of 214 patients, with a mean age of 9.8 ± 6.1 years (range 0.01-19.7 years), underwent 239 lung transplants: 231 bilateral and 8 single. Mean follow-up was 3.4 years. Forty-two airway complications requiring interventions (stenosis = 36; dehiscence = 4; malacia = 2) developed in 30 recipients (complication rate: 9% of 470 bronchial anastomoses at risk). There were airway complications in 29 bilateral lung transplants (13%) and 1 single lung transplant (13%). Mean time to diagnosis was 51 ± 27 days (median: 53, range 1-96 days), and diagnoses were made in 90% of patients within the first 3 months after transplantation. Preoperative Pseudomonas cepacia, postoperative fungal lung infection, and days on mechanical ventilator were found to be significant risk factors on multivariate analysis (P = .002, P = .013 and P = .003, respectively). Treatment included rigid bronchoscopic dilatation in 17 patients, balloon dilatation in 13 patients, and stent placement in 12 patients. Other treatments consisted of debridement, fibrin glue application, chest tube placement, and pneumonectomy followed by retransplantation. No patients died as a direct result of airway complications. There was no significant difference in the incidence of bronchiolitis obliterans or overall survival in comparison with patients who did not have airway complications.ConclusionsAirway complications are a significant cause of morbidity after pediatric lung transplantation. The majority are successfully treated, and patient outcomes are not adversely affected

Exodoncia: Comunicación bucosinusal : Tratamiento inmediato de las mismas

En mucho de los casos existe la posibilidad de que se produzca una comunicación bucosinusal durante la exodoncia. En primera instancia se debe realizar un correcto diagnostico a través de una placa radiográfica para poder implementar el tratamiento que corresponda, ya que en aquellos pacientes que presentan un seno maxilar demasiado neumatizado la apertura del antro es inminente cuando se deben extraer piezas dentarías en las que sus ápices están en intimo contacto con el piso del seno maxilar correspondiente. Una vez instalada dicha comunicación el tratamiento inmediato debe ser el cierre del alvéolo a través de una sutura hermética en las partes blandas para lograr así la formación del coagulo dentro del mismo y así favorecer la cicatrización.Facultad de Odontologí

A 2-MS/s, 11.22 ENOB, extended input range SAR ADC with improved DNL and offset calculation

A 12-bit successive approximation register analog-to-digital converter (ADC) with extended input range is presented. Employing an input sampling scaling technique, the presented ADC can digitize the signals with an input range of 3.2 V pp-d (±1.33 V REF ). The circuit also includes a comparator offset compensation technique that results in a residual offset of less than 0.5 LSB. The chip has been designed and implemented in a 0.13-μm CMOS process and demonstrates the state-of-the-art performance, featuring an SNDR of 69.3 dB and the SFDR of 79 dB without requiring any calibration. Total power consumption of the ADC is 0.9 mW, with a measured differential non-linearity of 1.2/-1.0 LSB and INL of 2.3/-2.2 LSB

The OPERA experiment Target Tracker

The main task of the Target Tracker detector of the long baseline neutrino oscillation OPERA experiment is to locate in which of the target elementary constituents, the lead/emulsion bricks, the neutrino interactions have occurred and also to give calorimetric information about each event. The technology used consists in walls of two planes of plastic scintillator strips, one per transverse direction. Wavelength shifting fibres collect the light signal emitted by the scintillator strips and guide it to both ends where it is read by multi-anode photomultiplier tubes. All the elements used in the construction of this detector and its main characteristics are described.Comment: 25 pages, submitted to Nuclear Instrument and Method

Mortality after emergency department intubation

Introduction The purpose of this study is to identify the rate of emergency department (ED) intubation and the mortality associated with ED intubation. Methods We conducted a retrospective chart review of all patients intubated in the ED between 1 January 2004 an

Percepção de estudantes de psicologia sobre a informática em sua formação profissional

Neste artigo analisa-se uma pesquisa de natureza qualitativa, cujo objetivo era explorar a percepção de 45 alunos de psicologia de diferentes universidades da cidade de Santiago do Chile, sobre a incorporação da informática como apoio para a aprendizagem em sua formação profissional. A informação foi coletada através de entrevistas semiestruturadas e analisou-se mediante o processo de codificação da Teoría Fundamentada. Os resultados mostram como categorias principais, o conhecimento da informática, a valoração da informática, e os fatores que obstaculizam o uso desta. Da codificação seletiva se desprende uma alta valoração da informática como ferramenta econômica e cômoda, mas também se observa uma alta reticência dos alunos diante de sua utilização no trabalho profissional tradicional do psicólogo. Encontraram-se fatores pessoais e institucionais nos que se baseia a valoração, a motivação e o nível de conhecimento dos estudantes diante do uso de ferramentas informáticas.This paper analyses a qualitative research aimed to exploring the perception of 45 psychology students from different universities in Santiago de Chile, about incorporating information systems to support learning in their professional training. Data were collected through semi structured interviews and their analysis was based on Grounded Theory's coding process. Results show that the major categories are computer knowledge, appreciation of computers and factors that hinder their use. From the selective coding a positive evaluation emerges of information systems as an economic and useful tool. However, there is also a high reluctance on the part of the students regarding the use of such tools in the psychologist' traditional professional work. Personal and organizational factors were found as bases for students' assessment, motivation and level of knowledge facing the use of these tools.En este artículo se analiza una investigación de naturaleza cualitativa, cuyo objetivo era explorar la percepción de 45 alumnos de psicología de diferentes universidades de la ciudad de Santiago de Chile, sobre la incorporación de la informática como apoyo para el aprendizaje en su formación profesional. La información se recolectó a través de entrevistas semiestructuradas y se analizó mediante el proceso de codificación de la Teoría Fundamentada. Los resultados muestran como categorías principales, el conocimiento de la informática, la valoración de la informática, y los factores que obstaculizan el uso de ésta. De la codificación selectiva se desprende una alta valoración de la informática como herramienta económica y cómoda, pero también se observa una alta reticencia de los alumnos frente a su utilización en el trabajo profesional tradicional del psicólogo. Se encontraron factores personales e institucionales en los cuales se fundamenta la valoración, la motivación y el nivel de conocimiento de los estudiantes frente al uso de herramientas informáticas

Long-term follow-up of beryllium sensitized workers from a single employer

<p>Abstract</p> <p>Background</p> <p>Up to 12% of beryllium-exposed American workers would test positive on beryllium lymphocyte proliferation test (BeLPT) screening, but the implications of sensitization remain uncertain.</p> <p>Methods</p> <p>Seventy two current and former employees of a beryllium manufacturer, including 22 with pathologic changes of chronic beryllium disease (CBD), and 50 without, with a confirmed positive test were followed-up for 7.4 +/-3.1 years.</p> <p>Results</p> <p>Beyond predicted effects of aging, flow rates and lung volumes changed little from baseline, while D_LCO dropped 17.4% of predicted on average. Despite this group decline, only 8 subjects (11.1%) demonstrated physiologic or radiologic abnormalities typical of CBD. Other than baseline status, no clinical or laboratory feature distinguished those who clinically manifested CBD at follow-up from those who did not.</p> <p>Conclusions</p> <p>The clinical outlook remains favorable for beryllium-sensitized individuals over the first 5-12 years. However, declines in D_LCO may presage further and more serious clinical manifestations in the future. These conclusions are tempered by the possibility of selection bias and other study limitations.</p