Inference and prediction in bulk arrival queues and queues with service in stages

This paper deals with the statistical analysis from a Bayesian point of view, of bulk arrival queues where the batch size is considered as a fixed constant. The focus is on prediction of the usual measures of performance of the system in the steady state. The probability generating function of the posterior predictive distribution of the number of customers in the system and the Laplace transform of the posterior predictive distribution of the waiting time in the system are obtained. Numerical inversion of these transforms is considered. Inference and prediction of its equivalent single queue with service in stages is also discussed. © 1998 John Wiley & Sons, Ltd.     

Correlative 3D cryo X-ray imaging reveals intracellular location and effect of designed antifibrotic protein–nanomaterial hybrids

Revealing the intracellular location of novel therapeutic agents is paramount for the understanding of their effect at the cell ultrastructure level. Here, we apply a novel correlative cryo 3D imaging approach to determine the intracellular fate of a designed protein–nanomaterial hybrid with antifibrotic properties that shows great promise in mitigating myocardial fibrosis. Cryo 3D structured illumination microscopy (cryo-3D-SIM) pinpoints the location and cryo soft X-ray tomography (cryo-SXT) reveals the ultrastructural environment and subcellular localization of this nanomaterial with spatial correlation accuracy down to 70 nm in whole cells. This novel high resolution 3D cryo correlative approach unambiguously locates the nanomaterial after overnight treatment within multivesicular bodies which have been associated with endosomal trafficking events by confocal microscopy. Moreover, this approach allows assessing the cellular response towards the treatment by evaluating the morphological changes induced. This is especially relevant for the future usage of nanoformulations in clinical practices. This correlative super-resolution and X-ray imaging strategy joins high specificity, by the use of fluorescence, with high spatial resolution at 30 nm (half pitch) provided by cryo-SXT in whole cells, without the need of staining or fixation, and can be of particular benefit to locate specific molecules in the native cellular environment in bio-nanomedicine.

A novel 3D cryo correlative approach locates designed therapeutic protein–nanomaterial hybrids in whole cells with high specificity and resolution. Detection of treatment-induced morphological changes, crucial for pre-clinical studies, are revealed.     

EPR study of the alimemazine cation radical

The EPR spectrum of alimemazine cation radicals (ALMZ⁺) in a perchlorate single crystal has been studied at 293 K. Since strong exchange interactions between the radicals did not allow the determination of the hyperfine splitting constants, the spectrum of an ALMZ⁺ solution, frozen at 77 K, was also studied. The results, checked by computer simulation, indicate orthorhombic symmetry of the g(2.0075, 2.0059, 2.0023) and hfs (A=3.6G; A=2.0G; A=15.6G) tensors.     

Suppression of back-to-back hadron pairs at forward rapidity in d+Au collisions at √s(NN)=200 GeV

Back-to-back hadron pair yields in d+Au and p+p collisions at √s(NN)=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η|<0.35 and the associated hadron at forward rapidity (deuteron direction, 3.0<η<3.8). Pairs were also detected with both hadrons measured at forward rapidity; in this case, the yield of back-to-back hadron pairs in d+Au collisions with small impact parameters is observed to be suppressed by a factor of 10 relative to p+p collisions. The kinematics of these pairs is expected to probe partons in the Au nucleus with a low fraction x of the nucleon momenta, where the gluon densities rise sharply. The observed suppression as a function of nuclear thickness, p(T), and η points to cold nuclear matter effects arising at high parton densities.     

Thermal decomposition of meat and bone meal

A series of runs has been performed to study the thermal behavior of meat and bone meal (MBM) both in inert and reactive atmosphere. Although they are actually burned, the thermal decomposition of such MBM wastes has not been studied from a scientific point of view until now. The aim of this work is to present and discuss the thermogravimetric behavior of MBM both in nitrogen and air atmospheres. A thermobalance has been used to carry out the study at three different heating rates. A kinetic scheme able to correlate simultaneously (with no variation of the kinetic constants) the runs performed at different heating rates and different atmospheres of reaction is presented.     

Near infrared spectroscopy: A novel technique for classifying and characterizing polysulfone membranes

The industrial manufacture of membranes is well established at the present time. More than any other process, the production of ultrafiltration membranes by immersion or evaporation (phase inversion) precipitation techniques is one of the most common. In many cases, the macroscopic properties of the membranes are similar from one membrane to another and it is impossible to distinguish them, while they differ notably from the microscopic point of view. The aim of this work is to develop a method for the classification of polysulfone ultrafiltration membranes prepared either by immersion or evaporation. It also presents a classification of those membranes by thickness. For these purposes, near infrared spectroscopy (NIR) combined with chemometric techniques are attempted here for the first time in the area of membrane research. The NIR technique permits fast analytical measurement of membrane samples, together with the possibility of characterization in on-line mode, without destruction or invasion of the samples. This appears to be an excellent routine analysis for purposes of membrane classification. The membranes were prepared in our Universitat Autònoma de Barcelona (UAB) laboratory and, after obtaining the NIR spectra, principal component analysis (PCA) was used to describe the system. The second stage involved the application of a pattern recognition method: supervised independent modeling of class analogy (SIMCA) in order to classify unknown samples. Finally, the ultrafiltration membranes were classified in terms of the membrane preparation technique (immersion or evaporation). In addition, membranes prepared by immersion were classified by thickness.     

Halide ion-selective electrode array calibration

The calibration of several ions (Cl(-), Br(-), F(-) and OH(-)) measured with an ion selective electrodes (ISE) array has been carried out in the presence of interferents using an experimental design and multivariate calibration methods. Partial least squares regression and principal component regression do not seem to improve the test set prediction compared to multivariate linear regression. In the case of very slight or no interference on the ISE, each ion can be determined using the corresponding ISE and univariate calibration methods, but the use of multivariate methods does not lead to worse results.     

Density functional calculations for modeling the oxidized states of the active site of nickel-iron hydrogenases. 1. Verification of the method with paramagnetic Ni and Co complexes

ZORA relativistic DFT calculations are presented which aim to reproduce geometric structures and EPR properties of [Ni(mnt)(2)](-) (H(2)mnt = maleonitrildithiol), two other paramagnetic low-spin Ni(III) complexes, and an asymmetric paramagnetic Co(II) complex. The study tests the accuracy of the computational method as a prior step to the modeling of the geometric and electronic structure of the active site of NiFe hydrogenases in its EPR-active oxidized states Ni-A and Ni-B. Systematic deviations from experiment are found for the calculated g-values; relative differences among them are, however, well reproduced. Because no significant improvements have been achieved by using larger basis sets or more sophisticated functionals, g-values may be calculated rather rapidly at the VWN level. This is most important for the modeling of the active site of NiFe hydrogenases because its complexity does not permit calculations at high levels of theory. For [Ni(mnt)(2)](-), excellent agreement between calculated and experimental results is obtained for the (14)N quadrupole coupling, whereas the calculated hyperfine couplings are not always in good agreement with experimental data.