Revisiting cell-particle association in vitro: A quantitative method to compare particle performance

Nanoengineering has the potential to revolutionize medicine by designing drug delivery systems that are both efficacious and highly selective. Determination of the affinity between cell lines and nanoparticles is thus of central importance, both to enable comparison of particles and to facilitate prediction of in vivo response. Attempts to compare particle performance can be dominated by experimental artifacts (including settling effects) or variability in experimental protocol. Instead, qualitative methods are generally used, limiting the reusability of many studies. Herein, we introduce a mathematical model-based approach to quantify the affinity between a cell-particle pairing, independent of the aforementioned confounding artifacts. The analysis presented can serve as a quantitative metric of the stealth, fouling, and targeting performance of nanoengineered particles in vitro. We validate this approach using a newly created in vitro dataset, consisting of seven different disulfide-stabilized poly(methacrylic acid) particles ranging from ~100 to 1000 nm in diameter that were incubated with three different cell lines (HeLa, THP-1, and RAW 264.7). We further expanded this dataset through the inclusion of previously published data and use it to determine which of five mathematical models best describe cell-particle association. We subsequently use this model to perform a quantitative comparison of cell-particle association for cell-particle pairings in our dataset. This analysis reveals a more complex cell-particle association relationship than a simplistic interpretation of the data, which erroneously assigns high affinity for all cell lines examined to large particles. Finally, we provide an online tool (http://bionano.xyz/estimator), which allows other researchers to easily apply this modeling approach to their experimental results

The Evaluation of Potentiostats: Electrochemical Detection Devices

This study evaluated the performance of three types of potentiostats; EmStat, CheapStat and UTMStat. EmStat is the smallest potentiostat available in the market. CheapStat is an open-source potentiostat suitable for educational applications. In addition, UTMStat is the extension of CheapStat, which was designed to overcome few weaknesses of CheapStat such as the input controller/ switch and data storage handling of the cyclic voltammogram. The cyclic voltammetry and amperometry measurements of ions ferrocyanide ([Fe(CN)6]4−) and chloride (Cl-) were carried out for each potentiostat. EmStat potentiostat is not only able to detect but also to measure ferrocyanide and chloride ions. However, CheapStat and UTMStat are only able to detect and measure ferrocyanide ions. The experiment is unable to be conducted due to limitation of waveform selection on both devices. Nevertheless, CheapStat and UTMStat could provide a reliable measurement to realize miniaturized lab-on-chip applications as shown in this study

Selection of transformation-efficient barley genotypes based on TFA (transformation amenability) haplotype and higher resolution mapping of the TFA loci

Barley (Hordeum vulgare) cv. ‘Golden Promise’ is one of the most useful and well-studied cultivars for genetic manipulation. In a previous report, we identified several transformation amenability (TFA) loci responsible for Agrobacterium-mediated transformation using the F2 generation of immature embryos, derived from ‘Haruna Nijo’ × ‘Golden Promise,’ as explants. In this report, we describe higher density mapping of these TFA regions with additional SNP markers using the same transgenic plants. To demonstrate the robustness of transformability alleles at the TFA loci, we genotyped 202 doubled haploid progeny from the cross ‘Golden Promise’ × ‘Full Pint.’ Based on SNP genotype, we selected lines having ‘Golden Promise’ alleles at TFA loci and used them for transformation. Of the successfully transformed lines, DH120366 came the closest to achieving a level of transformation efficiency comparable to ‘Golden Promise.’ The results validate that the genetic substitution of TFA alleles from ‘Golden Promise’ can facilitate the development of transformation-efficient lines from recalcitrant barley cultivars

Do online reviews reflect a product's true perceived quality? An investigation of online movie reviews across cultures

This paper investigates when the reported average of online ratings matches the perceived average assessment of the population as a whole, including the average assessments of both raters and non-raters. We apply behavioral theory to capture intentions in rating online movie reviews in two dissimilar countries – China and the United States. We argue that consumers’ rating behaviors are affected by cultural influences and that they are influenced in predictable ways. Based on data collected from IMDB.com and Douban.com, we found significant differences across raters from these two different cultures. Additionally, we examined how cultural elements influence rating behavior for a hybrid culture – Singapore. To study whether online consumer reviews are subjected to under-reporting bias, which is, consumers with extreme opinions are more likely to report their opinions than consumers with moderate reviews causing online reviews to be a biased estimator of a product’s true quality, we compare the consumer reviews posted online with those from an experimental study. Our results shows that under-reporting is more prevalent among US online network, thus online reviews are a better movie perceived quality proxy in China and Singapore than in the US

Do online reviews reflect a product’s true perceived quality? An investigation of online movie reviews across cultures

This paper investigates when the reported average of online ratings matches the perceived average assessment of the population as a whole, including the average assessments of both raters and non-raters. We apply behavioral theory to capture intentions in rating online movie reviews in two dissimilar countries – China and the United States. We argue that consumers’ rating behaviors are affected by cultural influences and that they are influenced in predictable ways. Based on data collected from IMDB.com and Douban.com, we found significant differences across raters from these two different cultures. Additionally, we examined how cultural elements influence rating behavior for a hybrid culture – Singapore. To study whether online consumer reviews are subjected to under-reporting bias, which is, consumers with extreme opinions are more likely to report their opinions than consumers with moderate reviews causing online reviews to be a biased estimator of a product’s true quality, we compare the consumer reviews posted online with those from an experimental study. Our results shows that under-reporting is more prevalent among US online network, thus online reviews are a better movie perceived quality proxy in China and Singapore than in the US

Ratings Lead You to the Product, Reviews Help you Clinch it? The Dynamics and Impact of Online Review Sentiments on Product Sales

Published in Decision Support Systems, 2014, 57, 42-53. http://dx.doi.org/10.1016/j.dss.2013.07.009</p

The evaluation of potentiostats: electrochemical detection devices

This study evaluated the performance of three types of potentiostats; EmStat, CheapStat and UTMStat. EmStat is the smallest potentiostat available in the market. CheapStat is an open-source potentiostat suitable for educational applications. In addition, UTMStat is the extension of CheapStat, which was designed to overcome few weaknesses of CheapStat such as the input controller/ switch and data storage handling of the cyclic voltammogram. The cyclic voltammetry and amperometry measurements of ions ferrocyanide ([Fe(CN)6]4−) and chloride (Cl-) were carried out for each potentiostat. EmStat potentiostat is not only able to detect but also to measure ferrocyanide and chloride ions. However, CheapStat and UTMStat are only able to detect and measure ferrocyanide ions. The experiment is unable to be conducted due to limitation of waveform selection on both devices. Nevertheless, CheapStat and UTMStat could provide a reliable measurement to realize miniaturized lab-on-chip applications as shown in this study

Characterization of Genetic and Allelic Diversity Amongst Cultivated and Wild Lentil Accessions for Germplasm Enhancement

Intensive breeding of cultivated lentil has resulted in a relatively narrow genetic base, which limits the options to increase crop productivity through selection. Assessment of genetic diversity in the wild gene pool of lentil, as well as characterization of useful and novel alleles/genes that can be introgressed into elite germplasm, presents new opportunities and pathways for germplasm enhancement, followed by successful crop improvement. In the current study, a lentil collection consisting of 467 wild and cultivated accessions that originated from 10 diverse geographical regions was assessed, to understand genetic relationships among different lentil species/subspecies. A total of 422,101 high-confidence SNP markers were identified against the reference lentil genome (cv. CDC Redberry). Phylogenetic analysis clustered the germplasm collection into four groups, namely, Lens culinaris/Lens orientalis, Lens lamottei/Lens odemensis, Lens ervoides, and Lens nigricans. A weak correlation was observed between geographical origin and genetic relationship, except for some accessions of L. culinaris and L. ervoides. Genetic distance matrices revealed a comparable level of variation within the gene pools of L. culinaris (Nei's coefficient 0.01468-0.71163), L. ervoides (Nei's coefficient 0.01807-0.71877), and L. nigricans (Nei's coefficient 0.02188-1.2219). In order to understand any genic differences at species/subspecies level, allele frequencies were calculated from a subset of 263 lentil accessions. Among all cultivated and wild lentil species, L. nigricans exhibited the greatest allelic differentiation across the genome compared to all other species/subspecies. Major differences were observed on six genomic regions with the largest being on Chromosome 1 (c. 1 Mbp). These results indicate that L. nigricans is the most distantly related to L. culinaris and additional structural variations are likely to be identified from genome sequencing studies. This would provide further insights into evolutionary relationships between cultivated and wild lentil germplasm, for germplasm improvement and introgression