Parallelizing Operational Weather Forecast Models for Portable and Fast Execution

This paper describes a high-level library (The Nearest Neighbor Tool, NNT) that has been used to parallelize operational weather prediction models. NNT is part of the Scalable Modeling System (SMS), developed at the Forecast Systems Laboratory (FSL). Programs written in NNT rely on SMS's run-time system and port between a wide range of computing platforms, performing well in multiprocessor systems. We show, using examples from operational weather models, how large Fortran 77 codes can be parallelized using NNT. We compare the ease of programmability of NNT and High Performance Fortran (HPF). We also discuss optimizations like data movement overlap (in interprocessor communication and I/O operations), and the minimization of data exchanges through the use of redundant computations. We show that although HPF provides a simpler programming interface, NNT allows for program optimizations that increase performance considerably and still keeps a simple user interface. These optimizations have proven essential to run weather prediction models in real time, and HPF compilers should incorporate them in order to meet operational demands. Throughout the paper, we present performance results of weather models running on a network of workstations, the Intel Paragon, and the SGI Challenge. Finally, we study the cost of programming global address space architectures with NNT's local address space paradigm.     

Novel Peptide‐Heterocycle Hybrids: Synthesis and Preliminary Studies on Calpain Inhibition

New peptidic compounds, having peptide chains linked to bi‐ and tricyclic heterocycles (peptide‐heterocycle hybrids), have been synthesized. The heterocyclic components are derivatives of partially reduced isoquinoline and pyrido[1,2‐b]isoquinoline bearing α,β‐unsaturated carbonyl functionalities. The heterocyclic compounds have been used as acylating agents in coupling reactions with short N‐unprotected peptides. Based on our interest on potential calpain inhibitors, we have used short (2–4 amino acids) peptides with hydrophobic amino acids of the two enantiomeric series. We report preliminary studies on the inhibition of calpain, with some compounds having IC₅₀ values in the nanomolar range.     

The Secretome of Human Neonatal Mesenchymal Stem Cells Modulates Doxorubicin-Induced Cytotoxicity: Impact in Non-Tumor Cells

Doxorubicin (Dox) is one of the most widely used treatments for breast cancer, although limited by the well-documented cardiotoxicity and other off-target effects. Mesenchymal stem cell (MSC) secretome has shown immunomodulatory and regenerative properties, further potentiated under 3D conditions. This work aimed to uncover the effect of the MSC-derived secretome from 3D (CM3D) or 2D (CM2D) cultures, in human malignant breast cells (MDA-MB-231), non-tumor breast epithelial cells (MCF10A) and differentiated AC16 cardiomyocytes, co-treated with Dox. A comprehensive proteomic analysis of CM3D/CM2D was also performed to unravel the underlying mechanism. CM3D/CM2D co-incubation with Dox revealed no significant differences in MDA-MB-231 viability when compared to Dox alone, whereas MCF10A and AC16 viability was consistently improved in Dox+CM3D-treated cells. Moreover, neither CM2D nor CM3D affected Dox anti-migratory and anti-invasive effects in MDA-MB-231. Notably, Ge-LC-MS/MS proteomic analysis revealed that CM3D displayed protective features that might be linked to the regulation of cell proliferation (CAPN1, CST1, LAMC2, RANBP3), migration (CCN3, MMP8, PDCD5), invasion (TIMP1/2), oxidative stress (COX6B1, AIFM1, CD9, GSR) and inflammation (CCN3, ANXA5, CDH13, GDF15). Overall, CM3D decreased Dox-induced cytotoxicity in non-tumor cells, without compromising Dox chemotherapeutic profile in malignant cells, suggesting its potential use as a chemotherapy adjuvant to reduce off-target side effects.     

Comparison of acids on the induction of an Acid Tolerance Response in Salmonellatyphimurium, consequences for food safety

Salmonellatyphimurium inactivation at pH 3.0 in Brain Heart Infusion (BHI) and Meat Extract (ME) was studied using stationary-phase cells grown in non-acidified BHI (pH 7.4) and ME (pH 6.6) and acidified BHI and ME at pH values of 6.4, 5.4 and 4.5 with acetic, ascorbic, citric, lactic, malic and hydrochloric acids. Cells grown in buffered BHI (pH 7.0) were used as non-acid adapted control cells.     

Dendrimer-based nanoprobe for dual modality magnetic resonance and fluorescence imaging

A novel PAMAM dendrimer-based nanoprobe for dual magnetic resonance and fluorescence imaging modalities was synthesized. Fluorescence studies revealed that Gd(III) complexation to the probe has no effect on the quantum yield; however, increases in the dye content resulted in partial quenching. The potential of the new nanoprobe, G6-(Cy5.5)(1.25)(1B4M-Gd)(145), as a dual modality imaging agent was demonstrated in vivo by the efficient visualization of sentinel lymph nodes in mice by both MRI and fluorescence imaging modalities.     

Membrane gas separation progresses for process intensification strategy in the petrochemical industry

The focus of this paper is on the progresses in membrane gas separation technology applied in the oil refining and petrochemical sector. Industrial applications, research trends on new materials and technical solutions, challenges and possible applications will be discussed. Other membrane operations will be briefly addressed, owing to their increasing number of installed systems in the refinery/petrochemical industry. This paper outlines how implementation of membrane technology in refineries and in the petrochemical industry result in Process Intensification (e.g., reduced footprint, better material utilization, reduced energy, reduced utilities and waste).     

Developing uranium dicarbide-graphite porous materials for the SPES project

Uranium carbide dispersed in graphite was produced under vacuum by means of carbothermic reduction of different uranium oxides (UO₂, U₃O₈ and UO₃), using graphite as the source of carbon. The thermal process was monitored by mass spectrometry and the gas evolution confirmed the reduction of the U₃O₈ and UO₃ oxides to UO₂ before the carbothermic reaction, that started to occur at T > 1000 °C. XRD analysis confirmed the formation of α-UC₂ and of a minor amount of UC. The morphology of the produced uranium carbide was not affected by the oxides employed as the source of uranium.     

Functionalization of polydimethylsiloxane membranes to be used in the production of voice prostheses

Abstract

The voice is produced by the vibration of vocal cords which are located in the larynx. Therefore, one of the major consequences for patients subjected to laryngectomy is losing their voice. In these cases, a synthetic one-way valve set (voice prosthesis) can be implanted in order to allow restoration of speech. Most voice prostheses are produced with silicone-based materials such as polydimethylsiloxane (PDMS). This material has excellent properties, such as optical transparency, chemical and biological inertness, non-toxicity, permeability to gases and excellent mechanical resistance that are fundamental for its application in the biomedical field. However, PDMS is very hydrophobic and this property causes protein adsorption which is followed by microbial adhesion and biofilm formation. To overcome these problems, surface modification of materials has been proposed in this study. A commercial silicone elastomer, Sylgard^TM 184 was used to prepare membranes whose surface was modified by grafting 2-hydroxyethylmethacrylate and methacrylic acid by low-pressure plasma treatment. The hydrophilicity, hydrophobic recovery and surface energy of the produced materials were determined. Furthermore, the cytotoxicity and antibacterial activity of the materials were also assessed. The results obtained revealed that the PDMS surface modification performed did not affect the material's biocompatibility, but decreased their hydrophobic character and bacterial adhesion and growth on its surface.     

Solubility of alkanes in a polystyrene matrix

The solubilities of seven alkanes in a matrix of uncrosslinked polystyrene were measured at several different temperatures. A gravimetric method reported earlier was used to monitor the sorption of the solvents. The experimental measurements showed unambiguously that the solubility of the alkanes diffusing into a polystyrene matrix reached a constant and reproducible value typical for each system and temperature. These values could be interpreted very well with the Flory–Huggins solubility parameter (χ = a(entropic contribution to x) + b(enthalpic contribution to x)/T[absolute temperature in Kelvin (K)]) or with the van't Hoff equation (ln K_S = ΔS/R(gas constant) ? ΔH/RT, where K_S is the equilibrium constant, ΔS is the entropy change, and ΔH is the enthalpy change). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008