Developing a Relationship Between LIBS Ablation and Pit Volume for In Situ Dating of Geologic Samples

In planetary exploration, in situ absolute geochronology is an important measurement. Thus far, on Mars, the age of the surface has largely been determined by crater density counting, which gives relative ages. These ages can have significant uncertainty as they depend on many poorly constrained parameters. More than that, the curves must be tied to absolute ages to relate geologic timescales on Mars to the rest of the solar system. Thus far, only the lost lander Beagle 2 was designed to conduct absolute geochronology measurements, though some recent attempts using MSL Curiosity show that this investigation is feasible (Reference Farley here) and should be strongly encouraged for future flight

The impacts of water vapour and co-pollutants on the performance of electrochemical gas sensors used for air quality monitoring

The analytical performance of low cost air pollution sensors under real-world conditions is a key factor that will influence their future uses and adoption. In this study five different electrochemical gas sensors (O3, SO2, CO, NO, NO2) are tested for their performance when challenged with cross interferences of water vapour and other gaseous co-pollutants. These experiments were conducted under both controlled laboratory conditions and during ambient air monitoring in urban background air at a site in York, UK. Signal outputs for O3, SO2 and CO showed a positive linear dependence on relative humidity (RH). The output for the NO sensor showed a negative correlation. The output for the NO2 sensor showed no trend with RH. Potential co-pollutants (O3, SO2, CO, NO2, NO and CO2) were introduced under controlled conditions using gas standards and delivered to each sensor in series along with variable RH. A matrix of cross-interference sensitivities were established which could be used to correct sensor signals. Interference-corrected sensor responses were compared against reference observations over an 18-day period. Once cross interferences had been removed the corrected 5 min averaging data for O3, CO, NO and NO2 sensors showed good agreement with the reference techniques with r2 values of 0.89, 0.76, 0.72, and 0.69, respectively. The SO2 sensor could not be evaluated in ambient air since ambient SO2 was below the sensor limit of detection

The impacts of water vapour and co-pollutants on the performance of electrochemical gas sensors used for air quality monitoring

The analytical performance of low cost air pollution sensors under real-world conditions is a key factor that will influence their future uses and adoption. In this study five different electrochemical gas sensors (O3, SO2, CO, NO, NO2) are tested for their performance when challenged with cross interferences of water vapour and other gaseous co-pollutants. These experiments were conducted under both controlled laboratory conditions and during ambient air monitoring in urban background air at a site in York, UK. Signal outputs for O3, SO2 and CO showed a positive linear dependence on relative humidity (RH). The output for the NO sensor showed a negative correlation. The output for the NO2 sensor showed no trend with RH. Potential co-pollutants (O3, SO2, CO, NO2, NO and CO2) were introduced under controlled conditions using gas standards and delivered to each sensor in series along with variable RH. A matrix of cross-interference sensitivities were established which could be used to correct sensor signals. Interference-corrected sensor responses were compared against reference observations over an 18-day period. Once cross interferences had been removed the corrected 5 min averaging data for O3, CO, NO and NO2 sensors showed good agreement with the reference techniques with r2 values of 0.89, 0.76, 0.72, and 0.69, respectively. The SO2 sensor could not be evaluated in ambient air since ambient SO2 was below the sensor limit of detection

Clinical outcomes and cost effectiveness of computerâ guided versus conventional implantâ retained hybrid prostheses: A longâ term retrospective analysis of treatment protocols

BackgroundComputerâ guided systems were developed to facilitate implant placement at optimal positions in relation to the future prosthesis. However, the time, cost and, technique sensitivity involved with computerâ guided surgery impedes its routine practice. The aim of this study is to evaluate survival rates and complications associated with computerâ guided versus conventional implant placement in implantâ retained hybrid prostheses. Furthermore, longâ term economic efficiency of this approach was assessed.MethodsPatients were stratified according to implant placement protocol into a test group, using computerâ guided placement, and a control group, using traditional placement. Calibrated radiographs were used to measure bone loss around implants. Furthermore, the costs of the initial treatment and prosthetic complications, if any, were standardized and analyzed.ResultsFortyâ five patients (149 implants in the test group and 111 implants in the control group) with a minimum followâ up of 5 years, and a mean followâ up of 9.6 years, were included in the study. While no significant difference was found between both groups in terms of biologic and technical complications, lower incidence of implant loss was observed in the test group (P  0.05).ConclusionsComputerâ guided implant placement for an implantâ supported hybrid prosthesis is a valid, reliable alternative to the traditional approach for implant placement and immediate loading. Computerâ guided implant placement showed higher implant survival rates and comparable longâ term cost to nonâ guided implant placement.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145504/1/jper10157.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145504/2/jper10157_am.pd

PCI - HIPPI Interface Modules

Interface modules between PCI local bus and HIPPI are described. The modules are intended to aid the implementation of the high performance computer network. the aimed maximum throughput of the interface module is 100MBytes/sec while sustained data transfer rate depends of the particular system performance

Sequential updating of a new dynamic pharmacokinetic model for caffeine in premature neonates

International audienceCaffeine treatment is widely used in nursing care to reduce the risk of apnoea in premature neonates. To check the therapeutic efficacy of the treatment against apnoea, caffeine concentration in blood is an important indicator. The present study was aimed at building a pharmacokinetic model as a basis for a medical decision support tool. In the proposed model, time dependence of physiological parameters is introduced to describe rapid growth of neonates. To take into account the large variability in the population, the Pharmacokinetic model is embedded in a population structure. The whole model is inferred within a Bayesian framework. To update caffeine concentration predictions as data of an incoming patient are collected, we propose a fast method that can be used in a medical context. This involves the sequential updating of model parameters (at individual and population levels) via a stochastic particle algorithm. Our model provides better predictions than the ones obtained with models previously published. We show, through an example, that sequential updating improves predictions of caffeine concentration in blood (reduce bias and length of credibility intervals). The update of the pharmacokinetic model using body mass and caffeine concentration data is studied. It shows how informative caffeine concentration data are in contrast to body mass data. This study provides the methodological basis to predict caffeine concentration in blood, after a given treatment if data are collected on the treated neonate

Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes

Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA3 ) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO 3 staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent

Effects of Ionomycin on Egg Activation and Early Development in Starfish

Ionomycin is a Ca2+-selective ionophore that is widely used to increase intracellular Ca2+ levels in cell biology laboratories. It is also occasionally used to activate eggs in the clinics practicing in vitro fertilization. However, neither the precise molecular action of ionomycin nor its secondary effects on the eggs' structure and function is well known. In this communication we have studied the effects of ionomycin on starfish oocytes and zygotes. By use of confocal microscopy, calcium imaging, as well as light and transmission electron microscopy, we have demonstrated that immature oocytes exposed to ionomycin instantly increase intracellular Ca2+ levels and undergo structural changes in the cortex. Surprisingly, when microinjected into the cells, ionomycin produced no Ca2+ increase. The ionomycin-induced Ca2+ rise was followed by fast alteration of the actin cytoskeleton displaying conspicuous depolymerization at the oocyte surface and in microvilli with concomitant polymerization in the cytoplasm. In addition, cortical granules were disrupted or fused with white vesicles few minutes after the addition of ionomycin. These structural changes prevented cortical maturation of the eggs despite the normal progression of nuclear envelope breakdown. At fertilization, the ionomycin-pretreated eggs displayed reduced Ca2+ response, no elevation of the fertilization envelope, and the lack of orderly centripetal translocation of actin fibers. These alterations led to difficulties in cell cleavage in the monospermic zygotes and eventually to a higher rate of abnormal development. In conclusion, ionomycin has various deleterious impacts on egg activation and the subsequent embryonic development in starfish. Although direct comparison is difficult to make between our findings and the use of the ionophore in the in vitro fertilization clinics, our results call for more defining investigations on the issue of a potential risk in artificial egg activation