Conditional Probability Of Finding Research Articles

A semiempirical model for adsorption of binary mixtures.

The statistical thermodynamics of polyatomic species mixtures adsorbed on two-dimensional lattices was developed based on generalization of the semiempirical approximation for the adsorption of single components [Romá, F. et al., Langmuir, 2006, 22, 3192-3197]. In this scheme, the partial adsorption isotherms are obtained using a correction function C[combining tilde], which relates to the conditional probability of finding the ith empty site to a lattice with i- 1 already vacant sites. This approximation allows us to write a new theoretical model using a combination of the correction functions corresponding to exact 1-D calculations and the Guggenheim-DiMarzio approach. Finally, comparisons with MC simulations and experimental data of methane-ethane and ethane-propylene mixtures on activated carbon are used to test the accuracy and reliability of the proposed model. The obtained results indicate that the new thermodynamic description is significantly better than the existing theoretical models developed to treat adsorption of interacting binary mixtures of polyatomics.

Counts of galaxy clusters as cosmological probes: the impact of baryonic physics

The halo mass function from N-body simulations of collisionless matter is generally used to retrieve cosmological parameters from observed counts of galaxy clusters. This neglects the observational fact that the baryonic mass fraction in clusters is a random variable that, on average, increases with the total mass (within an overdensity of 500). Considering a mock catalog that includes tens of thousands of galaxy clusters, as expected from the forthcoming generation of surveys, we show that the effect of a varying baryonic mass fraction will be observable with high statistical significance. The net effect is a change in the overall normalization of the cluster mass function and a milder modification of its shape. Our results indicate the necessity of taking into account baryonic corrections to the mass function if one wants to obtain unbiased estimates of the cosmological parameters from data of this quality. We introduce the formalism necessary to accomplish this goal. Our discussion is based on the conditional probability of finding a given value of the baryonic mass fraction for clusters of fixed total mass. Finally, we show that combining information from the cluster counts with measurements of the baryonic mass fraction in a small subsample of clusters (including only a few tens of objects) will nearly optimally constrain the cosmological parameters.

Effect of Stem Cell Source on Transplant Outcomes in Adults with Acute Leukemia: A Comparison of Unrelated Bone Marrow (BM), Peripheral Blood (PB) and Cord Blood (CB)

Currently, in the absence of an HLA matched sibling donor, an unrelated adult donor matched at 8 of 8 alleles for HLA A, B, C, DRB1 is preferred. However, the conditional probability of finding an 8 of 8 matched adult donor based on a preliminary analysis of the current National Marrow Donor Program donor registry is 51% for Caucasians, 30% for Hispanics, 20% for Asians and 17% for African Americans. Over the past decade, CB has emerged as an alternative. Just as an 8/8 HLA match with allele level typing is standard for recipients of BM and PB, a cell dose ≥2.5 × 107 nucleated cells/kg and ≥4/6 match with antigen level typing for A and B and allele-level for DRB1 are standard for recipients of CB today. To determine the relative efficacy of the three stem cell sources in the current era, we evaluated outcomes in 1240 adults aged >16 years with acute leukemia (707 AML; 533 ALL) transplanted after a myeloablative transplant preparatory regimen in 2002–2006. The graft was T replete BM (243 8/8 and 111 7/8 matched), T replete PB (518 8/8 and 210 7/8 matched) or CB (38 5–6/6 and 110 4/6 matched). Median follow up was 2 years in all groups. Compared to recipients of BM and PB, recipients of CB were younger (median age: 29 vs. 39 and 35 years, respectively) and more likely to have ALL. Disease status at transplantation was similar in all groups. As shown previously in children, the incidence of neutrophil recovery (□500/ul at day−42) was poorest in recipients of CB (78%) as compared to PB (96%) and BM (92%). Importantly, incidence of transplantrelated mortality (TRM) was less in recipients of 8/8 matched PB and BM as compared to those transplanted with 7/8 PB or 7/8 BM (p=0.001) or CB (p<0.001; recognizing that 74% of CB transplants were mismatched at 2 antigens). Probabilities of leukemia-free (LFS) and overall survival (OS) rates were highest in recipients of 8/8 matched PB and BM with no significant differences in TRM, LFS and OS rates in recipients of CB and 7/8 matched PB and BM. Together, these data suggest that8/8 matched PB or BM donor should be the first choice for adults with acute leukemia if time permits andpartially matched CB with an adequate cell dose is a suitable alternative for the large proportion of patients for whom an 8/8 matched unrelated adult donor cannot be identified or transplant is urgent.On the basis of prior studies in children demonstrating the potential impact of cell dose on outcomes, new strategies continue to be explored to reduce TRM and increase the efficacy of CB for adults with acute leukemia.TRMRelapseLFSOSPB, matched at A, B, C, DRB1 (8 of 8)27%30%43%45%BM, matched at A, B, C, DRB1(8 of 8)26%28%46%48%CB, matched or mismatched (6/6 n=9, 5/6 n=29, 4/6 n= 110)41%26%33%35%PB, mismatched at 1-locus (7 of 8)42%24%33%36%BM, mismatched at 1-locus (7 of 8)37%26%34%38%

Household Level Economic Incentives, Unemployment Trap and Job Finding Probability

This paper considers the sensitivity of the household's disposable income with respect to the labour market states and the labour market transitions of unemployed workers. The paper analyses the following questions: (i) which are the determinants of starting wages? (ii) how many unemployed are in the unemployment trap? (iii) how do household level economic incentives affect the conditional probability of finding a job? The empirical analysis is based on individual panel data covering the years 1987–1993 in Finland, when the unemployment rate rose from about 4% to 18%. We have estimated the starting wage equation to calculate the effects of hypothetical re-employment on the household's disposable income and to evaluate the frequency of the unemployment trap. To analyse factors affecting the transition out of unemployment to employment in open labour market, we estimate unemployment duration using a semi-parametric proportional risk model. The paper shows that the impact of the economic incentives, measured by the hypothetical change in household disposable income, on employment is more important in the recession than in the boom.

Exact results for one-dimensional totally asymmetric diffusion models

Several types of totally asymmetric diffusion models with and without exclusion are considered. For some models, conditional probabilities of finding N particles on lattice sites at time t with initial occupation at time t = 0 are expressed in a determinant form. On the other hand, the q-boson totally asymmetric diffusion model is introduced which interpolates the free boson model and the model with exclusion-like interaction. The effects of the interaction are compared for the case of two-particle diffusion.

Predicting Probabilities of Pregnancy and Multiple Gestation From In Vitro Fertilization—A New Model

In Brief Objective To develop a statistical model that adjusts for variation between patients and adequately predicts the observed distribution of pregnancies among singletons and multiple gestations of various orders. Methods All in vitro fertilization (IVF) cycles from the inception of the IVF program at Women and Infants' Hospital on May 26, 1988, until December 31, 1993, were evaluated using logistic regression in selected subsets. Results A new cycle-one specific model uses three different probabilities: P1, the probability of pregnancy (predicted by age and total embryo score); P2/P1, the conditional probability of finding a second implantation in those who had become pregnant with at least one (predicted by total embryo score); and P3/P2, the conditional probability of finding a third implantation in those who had become pregnant with at least two (with no significant predictors). This is the first model to use these three adjusted probabilities. Conclusion P1 increases with increasing total embryo score but decreases with increasing age. P2/P1 increases with increasing total embryo score but does not depend on age. Embryo scoring is useful because the total embryo score is a better predictor of P1 and P2/P1 than the number of embryos alone. By using patient-specific information (age and total embryo score) and cycle-specific tables, an estimate of the probability of pregnancy and multiple gestation can be provided before embryo transfer. To calculate probabilities of singletons, twins, and triplets, the probabilities of first, second, and third implantations must each be estimated.

Predicting Probabilities of Pregnancy and Multiple Gestation From In Vitro Fertilization—A New Model

Objective: To develop a statistical model that adjusts for variation between patients and adequately predicts the observed distribution of pregnancies among singletons and multiple gestations of various orders. Methods: All in vitro fertilization (IVF) cycles from the inception of the IVF program at Women and Infants’ Hospital on May 26, 1988, until December 31, 1993, were evaluated using logistic regression in selected subsets. Results: A new cycle-one specific model uses three different probabilities: P1, the probability of pregnancy (predicted by age and total embryo score); P2|P1, the conditional probability of finding a second implantation in those who had become pregnant with at least one (predicted by total embryo score); and P3|P2, the conditional probability of finding a third implantation in those who had become pregnant with at least two (with no significant predictors). This is the first model to use these three adjusted probabilities. Conclusion: P1 increases with increasing total embryo score but decreases with increasing age. P2|P1 increases with increasing total embryo score but does not depend on age. Embryo scoring is useful because the total embryo score is a better predictor of P1 and P2|P1 than the number of embryos alone. By using patient-specific information (age and total embryo score) and cycle-specific tables, an estimate of the probability of pregnancy and multiple gestation can be provided before embryo transfer.

Electron pairing and chemical bonds. Chemical structure, valences and structural similarities from the analysis of the Fermi holes

A new method of visualisation of bonding in molecules is introduced. The method is based on the analysis of Fermi holes associated with conditional probabilities of finding one electron of the pair provided the second, reference, electron is localised in a certain molecular region. Based on this analysis it is possible to get a clear and highly visual insight into the structure of molecular fragments (functional groups) in molecules. In addition to this visualisation, the new approach opens the possibility of the new definition of atomic and group valence and, also, can be applied as a new means of the quantitative characterisation of similarity of structural fragments in the series of related molecules.

One-Dimensional Stacking Order in Cs2PbCu(NO2)6

The successive Jahn-Teller phase transitions in Cs 2 PbCu(NO 2 ) 6 are studied with the X-ray scattering technique. Three ordered phases are observed to appear sequentially. The individual (001) atomic plane has the same antiferro-distorted structure throughout these ordered phases, and the structure of these phases is specified by giving the relative phase between the neighbouring (001) atomic layers. The conditional probabilities of finding a specified layer are determined by least-square fitting to the experimental diffraction characteristics. The close relationship between the stacking order of CDW in 1T-Ta 1- x Zn x Se 2 and the present system is discussed.

Percus-Yevick virial relation and scaled particle theory

The conditional probability of finding a cavityG(r) devoid of molecular centers of hard sphere fluid is modified by making use of the discontinuity atr=a/2 (a is the diameter of a molecule). The new equation of state thus obtained is bounded by the Percus-Yevick compressibility and virial pressure equations of state, which may be the upper and lower bounds to the results of machine calculation.