MALDI imaging mass spectrometry for direct tissue analysis: a new frontier for molecular histology

Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) is a powerful tool for investigating the distribution of proteins and small molecules within biological systems through the in situ analysis of tissue sections. MALDI-IMS can determine the distribution of hundreds of unknown compounds in a single measurement and enables the acquisition of cellular expression profiles while maintaining the cellular and molecular integrity. In recent years, a great many advances in the practice of imaging mass spectrometry have taken place, making the technique more sensitive, robust, and ultimately useful. In this review, we focus on the current state of the art of MALDI-IMS, describe basic technological developments for MALDI-IMS of animal and human tissues, and discuss some recent applications in basic research and in clinical settings

Estimating the Number of Paediatric Fevers Associated with Malaria Infection Presenting to Africa's Public Health Sector in 2007

Peter Gething and colleagues compute the number of fevers likely to present to public health facilities in Africa and the estimated number of these fevers likely to be infected with Plasmodium falciparum malaria parasites

Thermal Conductivity of Pyroclastic Soil (Pozzolana) from the Environs of Rome

The paper reveals the experimental procedure and thermo-physical characteristics of a coarse pyroclastic soil (Pozzolana), from the neighborhoods of Rome, Italy. The tested samples are comprised of 70.7% sand, 25.9% silt, and 3.4% clay. Their mineral composition contained 38% pyroxene, 33% analcime, 20% leucite, 6% illite/muscovite, 3% magnetite, and no quartz content was noted. The effective thermal conductivity of minerals was assessed to be about 2.14W·m−1·K−1. A transient thermal probe method was applied to measure the thermal conductivity (λ) over a full range of the degree of saturation (Sr), at two porosities (n) of 0.44 and 0.50, and at room temperature of about 25 ◦C. The λ data obtained were consistent between tests and showed an increasing trend with increasing Sr and decreasing n. At full saturation (Sr = 1), a nearly quintuple λ increase was observed with respect to full dryness (Sr = 0). In general, the measured data closely followed the natural trend of λ versus Sr exhibited by published data at room temperature for other unsaturated soils and sands. The measured λ data had an average root-mean-squared error (RMSE) of 0.007W·m−1·K−1 and 0.008W·m−1·K−1 for n of 0.50 and 0.44, respectively, as well as an average relative standard deviation of the mean at the 95%confidence level (RSDM0.95) of 2.21% and 2.72 % for n of 0.50 and 0.44, respectively. B V. R. Tarnawski vlodek.tarnawski

Canadian Field Soils IV: Modeling Thermal Conductivity at Dryness and Saturation

The thermal conductivity data of 40 Canadian soils at dryness (lambda(dry)) and at full saturation (lambda(sat)) were used to verify 13 predictive models, i.e., four mechanistic, four semi-empirical and five empirical equations. The performance of each model, for lambda(dry) and lambda(sat), was evaluated using a standard deviation (SD) formula. Among the mechanistic models applied to dry soils, the closest lambda(dry) estimates were obtained by MaxRTCM (SD = +/- 0.018 Wm(-1).K-1), followed by de Vries and a series-parallel model (S-||). Among the semi-empirical equations (deVries-ave, Advanced Geometric Mean Model (A-GMM), Chaudhary and Bhandari (C-B) and Chen's equation), the closest lambda(dry) estimates were obtained by the C-B model (+/- 0.022 Wm(-1).K-1). Among the empirical equations, the top lambda(dry) estimates were given by CDry-40 (+/- 0.021 Wm(-1).K-1 and +/- 0.018 Wm(-1).K-1 for18-coarse and 22-fine soils, respectively). In addition, lambda(dry) and lambda(sat) models were applied to the lambda(sat) database of 21 other soils. From all the models tested, only the maxRTCM and the CDry-40 models provided the closest lambda(dry) estimates for the 40 Canadian soils as well as the 21 soils. The best lambda(sat) estimates for the 40-Canadian soils and the 21 soils were given by the A-GMM and the S-|| model