Dusty Starbursts and the Growth of Cosmic Structure

Dusty starbursts were more numerous around z~1 than today and appear to be responsible for the majority of cosmic star formation over the Hubble time. We suggest that they represent a common phase within galaxies in general which is triggered by the growth of cosmic structure. We discuss the origin of the luminosity of luminous infrared galaxies at z~1. Are these galaxies dominated by star formation or nuclear activity ? What is triggering their strong activity ? Is it triggered by external interactions or did it happen naturally within isolated galaxies ? We present HST-ACS high resolution optical images of luminous infrared galaxies at z~0.7 showing the evolution of the morphology of these galaxies as a function of infrared luminosity, or star formation rate, and discuss the effect of the environment on their activity.Comment: 4 pages, 2 figures, to appear in Proceeding of the "Multi-Wavelength Cosmology" Conference held in Mykonos, Greece, June 2003, ed.M. Plionis (Kluwer

What fraction of stars formed in infrared galaxies at high redshift?

Star formation happens in two types of environment: ultraviolet-bright starbursts (like 30 Doradus and HII galaxies at low redshift and Lyman-break galaxies at high redshift) and infrared-bright dust-enshrouded regions (which may be moderately star-forming like Orion in the Galaxy or extreme like the core of Arp 220). In this work I will estimate how many of the stars in the local Universe formed in each type of environment, using observations of star-forming galaxies at all redshifts at different wavelengths and of the evolution of the field galaxy population.Comment: 7 pages, 0 figs, to appear in proceedings of "Starbursts - From 30 Doradus to Lyman break galaxies", edited by Richard de Grijs and Rosa M. Gonzalez Delgado, published by Kluwe

Evolution of the infrared luminosity density and star formation history up to z~1: preliminary results from MIPS

Using deep observations of the Chandra Deep Field South obtained with MIPS at 24mic, we present our preliminary estimates on the evolution of the infrared (IR) luminosity density of the Universe from z=0 to z~1. We find that a pure density evolution of the IR luminosity function is clearly excluded by the data. The characteristic luminosity L_IR* evolves at least by (1+z)^3.5 with lookback time, but our monochromatic approach does not allow us to break the degeneracy between a pure evolution in luminosity or an evolution in both density and luminosity. Our results imply that IR luminous systems (L_IR > 10^11 L_sol) become the dominant population contributing to the comoving IR energy density beyond z~0.5-0.6. The uncertainties affecting our measurements are largely dominated by the poor constraints on the spectral energy distributions that are used to translate the observed 24mic flux into luminosities.Comment: 4 pages, 2 figures. To be published in "Starbursts: From 30 Doradus to Lyman Break Galaxies", held in Cambridge, 6-10 September 2004, Ed. R. de Grijs & R. M. Gonzalez Delgad

Development of a planar multi-body model of the human knee joint

The aim of this work is to develop a dynamic model for the biological human knee joint. The model is formulated in the framework of multibody systems methodologies, as a system of two bodies, the femur and the tibia. For the purpose of describing the formulation, the relative motion of the tibia with respect to the femur is considered. Due to their higher stiffness compared to that of the articular cartilages, the femur and tibia are considered as rigid bodies. The femur and tibia cartilages are considered to be deformable structures with specific material characteristics. The rotation and gliding motions of the tibia relative to the femur can not be modeled with any conventional kinematic joint, but rather in terms of the action of the knee ligaments and potential contact between the bones. Based on medical imaging techniques, the femur and tibia profiles in the sagittal plane are extracted and used to define the interface geometric conditions for contact. When a contact is detected, a continuous non-linear contact force law is applied which calculates the contact forces developed at the interface as a function of the relative indentation between the two bodies. The four basic cruciate and collateral ligaments present in the knee are also taken into account in the proposed knee joint model, which are modeled as non-linear elastic springs. The forces produced in the ligaments, together with the contact forces, are introduced into the system’s equations of motion as external forces. In addition, an external force is applied on the center of mass of the tibia, in order to actuate the system mimicking a normal gait motion. Finally, numerical results obtained from computational simulations are used to address the assumptions and procedures adopted in this study.Fundação para a Ciência e a Tecnologia (FCT

Prescrição de antimicrobianos para idosos hospitalizados: análise do benefício e associação com implementação de limitação de esforço terapêutico e cuidados paliativos

Background and Objectives: Many advances have occurred in the prevention, diagnosis and treatment of infectious diseases, but they are still the main causes of hospitalization and death in older adults. The objective of this study was to verify the benefit of antimicrobial use and its association with the implementation of other therapeutic measures and with the indication of palliative care in the last two weeks of life of hospitalized older adults, in order to subsidize the development of rational models for this group. Methods: A retrospective study was carried out by analyzing the medical records of the older adult participants of the cohort epidemiological study ―Development of a Care Line for Older Adults at the University Hospital of Santa Maria‖, which presented death as an outcome. Results: Of the 97 individuals evaluated, 89.7% (n = 87) used antibiotics in the last two weeks of life. Among those who used antibacterial agents, 38.9% presented clinical signs of improvement after treatment initiation (n=28). Thus, it was possible to affirm that there was no association between symptom relief and antibacterial use (p = 0.377). Among those who benefited from antibiotic therapy, 46.4% were indicated for respiratory infection and 14.3% for urinary tract infection. We found no dependence between the use of antibacterial drugs and the other therapeutic measures adopted (p = 0.057), nor with the indication of palliative care (p = 0.065). Conclusion: There was little evidence of benefit in the use of antibiotics in the studied group, which indicates the need for a different care plan adequacy for this patient profile.Justificación y Objetivos: Ocurrieron muchos avances en la prevención, diagnóstico y tratamiento de las enfermedades infecciosas, pero todavía son las principales causas de hospitalización y muerte en ancianos. El presente trabajo tuvo como objetivo verificar el beneficio del uso de antimicrobianos y su asociación con la implementación de otras medidas terapéuticas y con la indicación de cuidados paliativos en las dos últimas semanas de vida de ancianos en internación hospitalaria con el fin de fomentar el desarrollo de modelos racionales de prescripción para este grupo. Métodos: Se desarrolló un estudio retrospectivo realizado por el análisis de historiales de los ancianos participantes del estudio epidemiológico del tipo cohorte ―Desarrollo de una línea de cuidados para el anciano en el Hospital Universitario de Santa María‖, que presentaron muerte como desenlace. Resultados: De los 97 individuos evaluados, el 89,7% (n = 87) hicieron uso de antibiótico en las dos últimas semanas de vida. Entre los que utilizaron el antibacteriano, el 38,9% presentó signos clínicos de mejora después del inicio del tratamiento (n = 28). Así fue posible afirmar que no hubo asociación entre el alivio de los síntomas y el uso de antibacteriano (p = 0,377). Entre los que se beneficiaron de la antibioticoterapia, el 46,4% fue indicado para infección respiratoria y el 14,3% para infección del tracto urinario. No se encontró dependencia entre el uso de antibacteriano y las otras medidas terapéuticas adoptadas (p = 0,057), ni con la indicación de cuidado paliativo (p = 0,065). Conclusión: Se observó poca evidencia de beneficio en el uso de antibacteriano en el grupo estudiado, lo que señala la necesidad de una adecuación del plan de cuidado diferenciada para ese perfil de pacientes.Justificativa e Objetivos: Muitos avanços ocorreram em prevenção, diagnóstico e tratamento das doenças infecciosas, porém elas ainda são as principais causas de hospitalização e morte em idosos. O objetivo deste trabalho foi verificar o benefício do uso de antimicrobianos e sua associação com a implementação de outras medidas terapêuticas e com a indicação de cuidados paliativos nas duas últimas semanas de vida de idosos em internação hospitalar, a fim de subsidiar o desenvolvimento de modelos racionais de prescrição para este grupo. Métodos: Foi desenvolvido um estudo retrospectivo realizado pela análise de prontuários dos idosos participantes do estudo epidemiológico do tipo coorte ―Desenvolvimento de uma linha de cuidados para o idoso no Hospital Universitário de Santa Maria‖ que apresentaram óbito como desfecho. Resultados: Dos 97 indivíduos avaliados, 89,7% (n = 87) fizeram uso de antibiótico nas duas últimas semanas de vida. Entre aqueles que utilizaram antibacteriano, 38,9% apresentaram sinais clínicos de melhora após o início do tratamento (n = 28). Assim, foi possível afirmar que não houve associação entre o alívio dos sintomas e o uso de antibacteriano (p = 0,377). Entre aqueles que se beneficiaram da antibioticoterapia, 46,4% foram indicados para infecção respiratória e 14,3% para infecção do trato urinário. Não foi encontrada dependência entre o uso de antibacteriano e as outras medidas terapêuticas adotadas (p = 0,057), nem com a indicação de cuidado paliativo (p = 0,065). Conclusão: Observou-se pouca evidência de benefício no uso de antibacteriano no grupo estudado, o que sinaliza a necessidade de uma adequação de plano de cuidado diferenciada para esse perfil de pacientes

The Mexican consensus on the diagnosis, treatment, and prevention of NSAID-induced gastropathy and enteropathy

Más de 30 millones de personas consumen diariamente antiinflamatorios noesteroideos (AINE) en el mundo, y este consumo se ve incrementado anualmente. Aunque losAINE poseen propiedades analgésicas y antiinflamatorias, sus eventos adversos gastrointesti-nales son bien reconocidos. En nuestro país no existía un consenso respecto al diagnóstico,tratamiento y prevención de la gastropatía y la enteropatía por AINE, por lo que la AsociaciónMexicana de Gastroenterología reunió a un grupo de expertos para establecer recomendacionesde utilidad para la comunidad médica. En este consenso se emitieron 33 recomendaciones. Elconsenso destaca que el riesgo de toxicidad gastrointestinal de los AINE varía según el fármacoempleado y su farmacocinética, lo cual debe ser considerado al momento de su prescripción. Losfactores de riesgo de complicación gastroduodenal por AINE son: antecedente de úlcera pép-tica, edad mayor a 65 a˜nos, dosis altas del AINE, infección por Helicobacter pylori (H.pylori), ypresencia de comorbilidades graves. Los síntomas y el da˜no gastroduodenal inducido por AINEson variables ya que puede cursar asintomático o manifestarse como anemia por deficiencia dehierro, hemorragia, estenosis y perforación. La cápsula endoscópica y la enteroscopia son méto-dos diagnósticos directos en la enteropatía por AINE. Respecto a la prevención, se recomiendaprescribir la dosis mínima necesaria de un AINE para obtener el efecto deseado y durante elmenor tiempo. Finalmente, los inhibidores de la bomba de protones (IBP) representan el están-dar de oro para la profilaxis y tratamiento de los efectos gastroduodenales, mas no son útilesen la enteropatía

Teste imunoenzimático com base em anticorpo monoclonal para a detecção de anticorpos contra os herpesvírus bovino tipos 1 e 5

Os herpesvírus bovino tipos 1 (BoHV-1) e 5 (BoHV-5) são agentes virais genética e antigenicamente relacionados, associados com diversas manifestações clínicas em bovinos, incluindo doença respiratória, genital, neurológica e abortos. Estudos epidemiológicos indicam que esses vírus estão amplamente disseminados no rebanho bovino brasileiro. O diagnóstico sorológico, que permite identificar animais portadores da infecção latente, se constitui em importante ferramenta para monitoramento individual e de rebanho. O presente artigo relata a padronização de um teste imunoenzimático do tipo ELISA, com base em anticorpo monoclonal (AcM), para a detecção de anticorpos séricos que reagem contra BoHV-1 e/ou BoHV-5. Inicialmente, determinou-se o AcM mais adequado para a sensibilização das placas, as diluições apropriadas do antígeno e dos soros-teste e o ponto de corte do ensaio. Após a padronização, o ensaio foi validado testando-se 506 amostras de soro bovino, previamente testadas para anticorpos neutralizantes contra BoHV-1 e/ou BoHV-5 pela técnica de soroneutralização (SN). Comparando-se com os resultados da SN frente a BoHV-1, o teste de ELISA apresentou sensibilidade e especificidade de 96,6% e 98,3%, respectivamente. Os valores preditivos positivo e negativo foram de 97,6%, a concordância foi de 97,6% e o índice de correlação kappa entre os testes foi de 0,95, o que indica uma excelente concordância. Comparando-se com os resultados da SN frente o BoHV-5, o ELISA apresentou 94,3% de sensibilidade; 97,9% de especificidade; 97,1% de valor preditivo positivo e 95,9% de valor preditivo negativo. Para BoHV-5, a concordância entre os testes foi de 96,4% e o índice de correlação foi de 0,92, também excelente. Esses resultados demonstram que o teste padronizado apresenta sensibilidade e especificidade adequados para o diagnóstico sorológico das infecções por BoHV-1 e BoHV-5 em nível individual e de rebanho. Dessa forma, o ensaio pode se constituir em alternativa para o teste de SN e para os kits de ELISA importados.Bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5) are antigenic and genetically related viruses associated with different clinical syndromes in cattle, including respiratory, reproductive, neurological disease and abortion. Epidemiological studies indicate the widespread distribution of both viruses among Brazilian cattle. Serological diagnosis, that allows the identification of latently infected animals, represents an important tool for individual and herd monitoring. The present article describes the standardization of a monoclonal antibody (MAb)-based immunoenzymatic test (ELISA) for detection of antibodies to BoHV-1 and/or BoHV-5. The initial steps involved the determination of the most suitable MAb, the appropriate dilutions of viral antigen and serum samples, and the cut-off value of the assay. After standardization, the ELISA was validated by testing 506 cattle serum samples previously tested for neutralizing antibodies to BoHV-1 and BoHV-5 by virus neutralizing assay (VN). Comparing to the VN for BoHV-1 antibodies, the ELISA presented sensitivity and specificity of 96.6% and 98.3%, respectively. Positive and negative predictive values were 97.6%, the concordance between the tests was 97.6% and the coefficient of correlation k (kappa) was 0.95, demonstrating an excellent correlation. Comparing to the VN for BoHV-5 antibodies, the ELISA presented 94.3% of sensitivity, 97.9% of specificity, 97.1% of positive predictive value, 95.9% negative predictive value, concordance of 96.4% and kappa coefficient of 0.92. These results demonstrate that the ELISA presents suitable specificity and sensitivity to be used for individual and herd serological diagnosis of BoHV-1 and BoHV-5, thus, representing an alternative for VN assays and imported ELISA kits

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe