Unconventional human T cells accumulate at the site of infection in response to microbial ligands and induce local tissue remodeling

The antimicrobial responsiveness and function of unconventional human T cells are poorly understood, with only limited access to relevant specimens from sites of infection. Peritonitis is a common and serious complication in individuals with end-stage kidney disease receiving peritoneal dialysis. By analyzing local and systemic immune responses in peritoneal dialysis patients presenting with acute bacterial peritonitis and monitoring individuals before and during defined infectious episodes, our data show that Vg9/ Vd2+ gd T cells and mucosal-associated invariant T cells accumulate at the site of infection with organisms producing (E)-4- hydroxy-3-methyl-but-2-enyl pyrophosphate and vitamin B2, respectively. Such unconventional human T cells are major producers of IFN-g and TNF-a in response to these ligands that are shared by many microbial pathogens and affect the cells lining the peritoneal cavity by triggering local inflammation and inducing tissue remodeling with consequences for peritoneal membrane integrity. Our data uncover a crucial role for Vg9/Vd2 T cells and mucosal-associated invariant T cells in bacterial infection and suggest that they represent a useful predictive marker for important clinical outcomes, which may inform future stratification and patient management. These findings are likely to be applicable to other acute infections where local activation of unconventional T cells contributes to the antimicrobial inflammatory response

THz commensurate echoes: Periodic rephasing of molecular transitions in free-induction decay

We report the first study of coherent transients excited by ultrafast pulses of THz radiation. Using a newly developed optoelectronic source of well-collimated beams of subpicosecond pulses of THz radiation to excite N2O vapor, we have observed the subsequent emission from the vapor of coherent THz pulse trains extending to as long as 1 nsec. The origin of these subpicosecond THz pulses (echoes) is a periodic rephasing, during the free-induction decay, of the more than fifty coherently excited rotational lines with commensurate transition frequencies. From the decay and reshaping of the echoes the coherent relaxation time T2 and the anharmonicity factor for the N2O molecule are evaluated.Peer reviewedElectrical and Computer Engineerin

Machine-learning algorithms define pathogen-specific local immune fingerprints in peritoneal dialysis patients with bacterial infections

The immune system has evolved to sense invading pathogens, control infection, and restore tissue integrity. Despite symptomatic variability in patients, unequivocal evidence that an individual's immune system distinguishes between different organisms and mounts an appropriate response is lacking. We here used a systematic approach to characterize responses to microbiologically well-defined infection in a total of 83 peritoneal dialysis patients on the day of presentation with acute peritonitis. A broad range of cellular and soluble parameters was determined in peritoneal effluents, covering the majority of local immune cells, inflammatory and regulatory cytokines and chemokines as well as tissue damage–related factors. Our analyses, utilizing machine-learning algorithms, demonstrate that different groups of bacteria induce qualitatively distinct local immune fingerprints, with specific biomarker signatures associated with Gram-negative and Gram-positive organisms, and with culture-negative episodes of unclear etiology. Even more, within the Gram-positive group, unique immune biomarker combinations identified streptococcal and non-streptococcal species including coagulase-negative Staphylococcus spp. These findings have diagnostic and prognostic implications by informing patient management and treatment choice at the point of care. Thus, our data establish the power of non-linear mathematical models to analyze complex biomedical datasets and highlight key pathways involved in pathogen-specific immune responses

IMPROVE-PD Finder: A Web-Based Platform to Search and Share Peritoneal Dialysis Biobank, Registry, and Clinical Trial Metadata

Peritoneal dialysis (PD) is a life-sustaining kidney replacement therapy for the increasing number of people with permanent kidney failure across all age groups worldwide. Although PD potentially offers socioeconomic and performance benefits over hemodialysis, both treatments severely accelerate complications of chronic kidney disease, in particular atherosclerotic disease progression that worsens outcomes when compared with non-dialysis patients.1 Improved understanding of the underlying molecular pathogenic mechanisms should help in the design of interventions that improve outcomes.2 Current state of the art in PD research, however, faces major limitations. Although there are numerous in vitro and ex vivo studies on complex cellular and molecular networks active in PD3, 4, 5 and in vivo animal models of PD6, 7, 8 that provide in-depth pathomechanistic insights and allow identification of promising therapeutic targets,9,S1,S2 translation into clinical studies is a major challenge.S3 Patient studies that aim to substantiate experimental findings with definitive clinical outcome data are mostly small. As a result, they have not provided sufficient power to derive meaningful or clinically implementable conclusions.2 Basic PD technique has hardly changed over decades, despite high PD-related complication rates. Randomized prospective trials with hard clinical end points studied with adequate power are difficult to realize in a multifactorial setting with low patient numbers (360,000 worldwide) and are associated with high costs. To overcome these barriers intermediate end points such as PD effluent biomarkers associated (but not necessarily causally related) with hard clinical end points and composite end points are often studied.S4,S5 Equally, combining analyses of existing cohort studies and trial data through collaborative sharing might be of considerable benefit

ASSIGNMENT OF A COMBINATION STATE vt=1+vt′=1v_{t} = 1 + v_{t}{'} = 1 of (H3CO)3(H_{3}CO)_{3}

Author Institution: Laboratoire de Spectroscopie Hertzienne Associ\'{e} au C. N. R. S.(La 249)Trioxane molecule $(H_{2}CO)_{3}$ permits us to observe rotational spectra of an excited state $v_{t} = 1+ v_{t}^{\prime} =1$ the vibrational energy for which is located at $832\, cm^{-1}$ from the ground state. Microwave transitions have been measured in the frequency range 60 up to 140 GHz, that is to say for values of the quantum number J going from 6 to 13. Analysis of the spectra relies on the hypothesis that there is no accidentally strong resonance between the vibrational states concerned and thus the expressions reported by TARRAGO can be used. Most precisely the assignment is made from the splitting of the $K = 0, \Sigma_{t} \ell_{t} = 0$ transitions. Accurate parameters are obtained by a direct diagonalization of the energy matrix and a least squares procedure. Most of the observed frequencies agree with the calculated ones."

LINESHAPE MODEL ANALYSIS FOR MEASUREMENTS IN THE MICROWAVE REGION

$^{a}$J.-F. D'Eu, B. Lemoine, F. Rohart, J. Mol. Spectrosc. in press (2002).Author Institution: Laboratoire de Physique des Lasers, Atomes et Mol\'{e}cules, UMR-CNRS/Universit\'{e} de Lille I, Centre d'Etudes et de Recherches Lasers et Applications, Universit\'{e} des Sciences et Technologies de LilleWe present lineshape studies performed in the millimeter range on CO and $N_{2}O$ in collision with various perturbing gases ($N_{2}, O_{2}, CO_{2}, H_{2}$, rare gases). Beside the goal of providing accurate spectroscopic parameters allowing for fine analysis of atmospheric spectra, reported measurements have given a clear evidence of line narrowing processes, that is of a failure of the Voigt profile. These experimental observations have allowed tackling studies on the physical origin of frequently reported line narrowings. Up to a recent time and from a pure numerical point of view, it was generally recognized that Galatry and Speed Dependent Voigt profiles lead to an equal quality in the fitting of experimental lineshapes. As a consequence, it was not possible to distinguish between the two possible origins of narrowing effects: velocity/speed changing collisions (Dicke or diffusion process) or speed dependence of relaxation rates. From our observations, it is observed that the optical diffusion parameter involved in the Galatry profile may have a strongly nonlinear pressure dependence, in agreement with similar observations reported on infrared HCN $lines^{a}$. As a general conclusion, it seems possible to claim that, except for the case of very light collision partners (He and $H_{2}$), narrowing effects originate mainly from the speed dependence of relaxation rates that have to be modeled by a Speed Dependent Voigt profile

Optimización del sistema de bombeo mecanico del campo tigre

El continuo cambio de las bombas de subsuelo y los problemas presentados en las varillas de succión que se utilizan en el sistema de Bombeo Mecánico del Campo Tigre, motivó la realización de este trabajo, con el fin de establecer el tipo de bomba que mejor se adapte a las necesidades de cada pozo además de la sarta de varillas, motor de superficie y su respectiva unidad de bombeo. Este trabajo se llevó a cabo siguiendo las siguientes fases: La primera fase consistió en identificar mediante un control estadístico los problemas más comunes que han originado los cambios de bombas. La segunda fase se dedicó a la actualización de la configuración mecánica de los pozos, para conocer la completación real y definir aspectos relacionados con cambios posibles del equipo. Luego se hizo un inventario general de los tipos de bombas disponibles así como también el tipo de unidades de bombeo y motores operando en los pozos. La tercera fase consistió en calcular la máxima tasa de producción de cada pozo, sobre la base de estimaciones de las presiones estática y fluyente de los pozos. En esta fase cobraron mucha importancia las cartas dinamométricas y medición de niveles que se le hicieron a los pozos. Con ayuda de estos datos, sumados a los del fluido producido por cada pozo, se procedió al análisis del conjunto bomba-varillas-motor-unidad de bombeo de cada pozo. En este punto se determinó que la gran mayoría del equipo que utilizan los pozos están sobredimensionados, considerando los parámetros de diseño que actualmente tiene cada pozo, tales como carrera superficial y velocidad de bombeo. Finalmente, se dan las recomendaciones sobre el tipo de bomba que se debería utilizar en cada pozo, la sarta de varillas más adecuada de acuerdo a las recomendaciones del Instituto Americano del Petróleo, el motor y la unidad de bombeo para cada pozo. Es posible mantener la misma producción de los pozos realizando sencillos ajustes al diseño de su sistema de bombeo, logrando con ello el incremento de la eficiencia y durabilidad de las bombas de subsuelo, y una reducción del esfuerzo de los motores. Todo ello redundará en un alargamiento de la vida útil de toda la instalación con los consiguientes beneficios económicos

Detección de problemas de alto corte de agua en el yacimiento hollín principal y sus posibles soluciones: bloque 7, del oriente ecuatoriano

El objetivo de este estudio es el análisis de los altos cortes de agua en los pozos completados en Hollín Principal del Campo Coca-Payamino, Bloque 7, del Mapa Catastral Petrolero Ecuatoriano, identificando sus causas y presentando recomendaciones técnicas para mejorar la economía del proyecto. Se elaboró en este estudio las curvas de producción anual de petróleo, de producción total de líquido y de WOR (4), iniciando en enero de 1991 y finalizando en abril de 1998, observándose claramente problemas de alta producción de agua. Para el diagnóstico, se han empleado procedimientos conocidos como el análisis del WOR y su derivada (6, 7), así como el de la tasa crítica de conificación (8). Con este análisis se ha determinado como causas principales de la alta producción de agua, la baja relación de permeabilidad horizontal/vertical (kh/kv) que existe en el yacimiento; y, la alta viscosidad del petróleo a condiciones de yacimiento, lo que ha provocado una mayor movilidad del agua. Sin embargo, las altas tasas de producción de líquido resultan ser el principal motivo para que se hayan presentado, en un tiempo muy corto, altos cortes de agua; aunque, en ciertos pozos, la presencia de multicapas ha retrasado la aparición de estos elevados cortes del agua. La tasa crítica por pozo (qc), ha sido calculada en máximo 32 bls/d pero, lamentablemente, esta tasa no resulta rentable por lo reducida y por el largo tiempo requerido para el retorno de la inversión. Sería conveniente, correr los registros de PLT (6) y RST (6), para determinar con exactitud el camino de la entrada de agua y su magnitud. Conviene, de otro lado, diseñar nuevas completaciones para separación del agua y del crudo, dentro del pozo mismo (4, 12, 13); de esta manera, buena parte de esta agua se volvería a inyectar desde el fondo mismo y debido a la reducción de la presión hidrostática en el pozo, se esperaría aumentar la producción de petróleo

LINESHAPE STUDY OF THE J=3−2J=3-2 ROTATIONAL TRANSITION OF CO PERTURBED BY N2N_{2} AND O2O_{2}

Author Institution: Laboratoire de Physique des Lasers, Atomes et Mol\'{e}cules; Laboratoire de Photophysique Mol\'{e}culaire, Universit\'{e} de Paris-SudWe report on the collisional relaxation of the $J=3-2$ rotational line of CO induced by nitrogen and oxygen. Measurements have been made by using a millimeter wave video-type spectrometer at several temperatures between 240 and 400K. In the 20-400 m Torr pressure range investigated, significant deviations from the Voigt profile have been observed. The observed lineshapes have been studied by means of a quasi-analytical speed dependent Galatry profile. This allows to point out a correlation between the parameters describing the speed dependence of relaxation and the molecular diffusion. The retrieved collisional relaxation coefficients and their temperature dependence both favourably compare to previous reported measurements. Theoretical results obtained from the Robert-Bonamy collisional formalism and from the brownian motion theory allows to consider the possible origins of observed lineshapes