Analysis of combined isotropic and anisotropic line-width data with a view to improved rotational CARS thermometry

Includes bibliographical references.The development of a new line-width model and recently measured rotational (anisotropic) line-widths has allowed for a critical analysis of the various basis rates models. These basis rates will be analysed using both vibrational (isotropic) and rotational line-width data. The data sets are analysed individually and in combination. For all fits, parameter correlations are determined. In addition, the sensitivity of the goodness of fit to variations in the effective interaction length for collisions, le, is investigated. To complete the investigation full rotational spectra are calculated and compared with experimental spectra

Potato Cultivar Differences Associated with Mealiness

Russet Burbank, Norchip, Pontiac, and LaSoda potato cultivars were examined for the parameters mealy and waxy. Russet Burbank was judged dry, hard and particulate, typifying mealiness. Using phase contrast microscopy and scanning electron microscopy, raw mealy cells were determined to be larger and more irregularly shaped than cells from waxy cultivars. Mealy cooked cells were engorged with gelatinized starch, cell walls were more polarized, and cell shapes were better retained after mashing, when compared to waxy cells. NMR-T2 bound water readings from Russet Burbank and Pontiac samples did not differ from each other. Starch granule sizes and shapes varied by cultivar

Microscopic Characterization of a Transposon-Induced Male-Sterile, Female-Sterile Mutant in Glycine max L.

Premise of research. A male-sterile, female-sterile mutant was discovered in a w4-m mutable line of Glycine max L. The mechanism of its sterility was not well understood. Therefore, different cytological and microscopic techniques were undertaken to better understand the process of mutant phenotype development. Molecular research indicated that mer3 was responsible for the sterility. Methodology. Macro images were collected of whole plants, flowers, anthers, pods, and ovules. Chromosome spreads from anthers at various meiotic stages were examined. Confocal scanning laser microscopy using optical sectioning was utilized on whole anthers and ovules at various developmental stages. Whole mature anthers and isolated pollen images were collected and studied with SEM. Pivotal results. In observations of the mutant, male cell development was found to begin normally and then digresses at metaphase I of meiosis, when abnormal segregation of chromosomes with reduced bivalent formation was observed. It was the abnormal formation of univalents and bivalents that led to male sterility. On the female side, the progression of development was arrested in the megagametophyte stage likely because of abnormal meiosis, leading to ovule abortion and female sterility. Conclusions. The G. max male-sterile, female-sterile mutant was shown to have the same phenotype of mer3 sterility already shown in Arabidopsis, rice, yeast, and some animal systems

Extreme Cranial Ontogeny in the Upper Cretaceous Dinosaur Pachycephalosaurus

BACKGROUND: Extended neoteny and late stage allometric growth increase morphological disparity between growth stages in at least some dinosaurs. Coupled with relatively low dinosaur density in the Upper Cretaceous of North America, ontogenetic transformational representatives are often difficult to distinguish. For example, many hadrosaurids previously reported to represent relatively small lambeosaurine species were demonstrated to be juveniles of the larger taxa. Marginocephalians (pachycephalosaurids + ceratopsids) undergo comparable and extreme cranial morphological change during ontogeny. METHODOLOGY/PRINCIPAL FINDINGS: Cranial histology, morphology and computer tomography reveal patterns of internal skull development that show the purported diagnostic characters for the pachycephalosaurids Dracorex hogwartsia and Stygimoloch spinifer are ontogenetically derived features. Coronal histological sections of the frontoparietal dome of an adult Pachycephalosaurus wyomingensis reveal a dense structure composed of metaplastic bone with a variety of extremely fibrous and acellular tissue. Coronal histological sections and computer tomography of a skull and frontoparietal dome of Stygimoloch spinifer reveal an open intrafrontal suture indicative of a subadult stage of development. These dinosaurs employed metaplasia to rapidly grow and change the size and shape of their horns, cranial ornaments and frontoparietal domes, resulting in extreme cranial alterations during late stages of growth. We propose that Dracorex hogwartsia, Stygimoloch spinifer and Pachycephalosaurus wyomingensis are the same taxon and represent an ontogenetic series united by shared morphology and increasing skull length. CONCLUSIONS/SIGNIFICANCE: Dracorex hogwartsia (juvenile) and Stygimoloch spinifer (subadult) are reinterpreted as younger growth stages of Pachycephalosaurus wyomingensis (adult). This synonymy reduces the number of pachycephalosaurid taxa from the Upper Cretaceous of North America and demonstrates the importance of cranial ontogeny in evaluating dinosaur diversity and taxonomy. These growth stages reflect a continuum rather than specific developmental steps defined by "known" terminal morphologies

Physico-electrochemical Characterization of Pluripotent Stem Cells during Self-Renewal or Differentiation by a Multi-modal Monitoring System.

Monitoring pluripotent stem cell behaviors (self-renewal and differentiation to specific lineages/phenotypes) is critical for a fundamental understanding of stem cell biology and their translational applications. In this study, a multi-modal stem cell monitoring system was developed to quantitatively characterize physico-electrochemical changes of the cells in real time, in relation to cellular activities during self-renewal or lineage-specific differentiation, in a non-destructive, label-free manner. The system was validated by measuring physical (mass) and electrochemical (impedance) changes in human induced pluripotent stem cells undergoing self-renewal, or subjected to mesendodermal or ectodermal differentiation, and correlating them to morphological (size, shape) and biochemical changes (gene/protein expression). An equivalent circuit model was used to further dissect the electrochemical (resistive and capacitive) contributions of distinctive cellular features. Overall, the combination of the physico-electrochemical measurements and electrical circuit modeling collectively offers a means to longitudinally quantify the states of stem cell self-renewal and differentiation

The variable toxicity of silver ions in cell culture media

The elevated interest in silver ions (Ag+) as a broad spectrum antimicrobial for use on medical devices has increased the number and importance of in vitro biocompatibility testing, however little consideration is given to the culture environment in which the assessments are performed. The current investigation assessed the viability of mouse fibroblasts (L929) exposed to different concentrations of Ag+ in both Dulbecco's modified Eagle's medium (DMEM) and minimal essential medium Eagle, alpha modification (αMEM). We identified a significant increase in the EC50 of L929 cells exposed to Ag+ in αMEM compared to DMEM, which was matched by a corresponding decrease in Ag+ availability in αMEM at concentrations ≤400 μM, as detected by inductively coupled plasma mass spectrometry (ICP-MS). The reduced availability was not observed for Ag+ > 400 μM, the concentration above which caused in vitro cytotoxicity in L929 cells in αMEM; while linear quantification of Ag+ was observed in DMEM. Equilibration of the chloride and glucose components between media did not affect cytotoxicity on primary test cells; mesenchymal stromal cells (MSCs). Overall, our results present evidence of the importance of culture conditions on the in vitro evaluation of silver, with DMEM providing a reliable basal media in which to conduct assessments