Implications of hobnail features in anaplastic thyroid carcinoma and precursor lesions

Anaplastic thyroid carcinoma (ATC) has the poorest prognosis of all thyroid cancers. Morphologically, it is characterized by pleomorphic undifferentiated cells. In some cases, a differentiated precursor lesion, either papillary thyroid carcinoma (PTC) or follicular thyroid carcinoma, can be identified adjacent to the anaplastic component. There are certain morphological variants of PTC that are known to be associated with more aggressive behavior, but a recently described, understudied variant is the hobnail variant. It is characterized histologically by micropapillary structures lined by cells with abundant eosinophilic cytoplasm and apically-placed bulging nuclei. The aim of this study was to evaluate the frequency of hobnail cells in ATC and associated precursor lesions. Microscopic slides from 21 cases of ATC diagnosed at Thomas Jefferson University Hospital between 2014 and 2017 were studied. 11 cases had an identifiable differentiated component, 8 of which were PTC. Hobnail cells were identified within the precursor PTC lesion in 5/8 of these cases. The high frequency of hobnail features in PTC precursor lesions associated with ATC suggests that hobnail features are an indicator of tumor aggressiveness. Further study is warranted to determine the prognostic value of hobnail cells in thyroid neoplasms

Meeting the requirements of both classroom-based and systemic assessment of mathematics proficiency: the potential of Rasch measurement theory

The challenges inherent in assessing mathematical proficiency depend on a number of factors, amongst which are an explicit view of what constitutes mathematical proficiency, an understanding of how children learn and the purpose and function of teaching. All of these factors impact on the choice of approach to assessment. In this article we distinguish between two broad types of assessment, classroom-based and systemic assessment. We argue that the process of assessment informed by Rasch measurement theory (RMT) can potentially support the demands of both classroom-based and systemic assessment, particularly if a developmental approach to learning is adopted, and an underlying model of developing mathematical proficiency is explicit in the assessment instruments and their supporting material. An example of a mathematics instrument and its analysis which illustrates this approach, is presented. We note that the role of assessment in the 21st century is potentially powerful. This influential role can only be justified if the assessments are of high quality and can be selected to match suitable moments in learning progress and the teaching process. Users of assessment data must have sufficient knowledge and insight to interpret the resulting numbers validly, and have sufficient discernment to make considered educational inferences from the data for teaching and learning responses

Mathematics, curriculum and assessment : the role of taxonomies in the quest for coherence

A challenge encountered when monitoring mathematics teaching and learning at high school is that taxonomies such as Bloom’s, and variations of this work, are not entirely adequate for providing meaningful feedback to teachers beyond very general cognitive categories that are difficult to interpret. Challenges of this nature are also encountered in the setting of examinations, where the requirement is to cover a range of skills and cognitive domains. The contestation as to the cognitive level is inevitable as it is necessary to analyse the relationship between the problem and the learners’ background experience. The challenge in the project described in this article was to find descriptive terms that would be meaningful to teachers. The first attempt at providing explicit feedback was to apply the assessment frameworks that include a content component and a cognitive component, namely knowledge, routine procedures, complex procedures and problem solving, currently used in the South African curriculum documents. The second attempt investigated various taxonomies, including those used in international assessments and in mathematics education research, for constructs that teachers of mathematics might find meaningful. The final outcome of this investigation was to apply the dimensions required to understand a mathematical concept proposed by Usiskin (2012): the skills-algorithm, property-proof, use-application and representation-metaphor dimension. A feature of these dimensions is that they are not hierarchical; rather, within each of the dimensions, the mathematical task may demand recall but may also demand the highest level of creativity. For our purpose, we developed a two-way matrix using Usiskin’s dimensions on one axis and a variation of Bloom’s revised taxonomy on the second axis. Our findings are that this two-way matrix provides an alternative to current taxonomies, is more directly applicable to mathematics and provides the necessary coherence required when reporting test results to classroom teachers. In conclusion we discuss the limitations associated with taxonomies for mathematics.Michael and Susan Dell Foundationhttp://www.pythagoras.org.zatm201

An application of the Rasch measurement theory to an assessment of geometric thinking levels

The purpose of this study is to apply the Rasch model to investigate both the Van Hiele theory for geometric development and an associated test. In terms of the test, the objective is to investigate the functioning of a classic 25-item instrument designed to identify levels of geometric proficiency. The data set consists of responses by 244 students (106 for a pre-test and 138 for a post-test) of which 76 students sat both the pre-test and the post-test. The summary item statistics do not show statistically discernible differences between observed and expected scores under the Rasch model (Chi-square statistic). The Rasch analysis confirms to some strong extent the Van Hiele theory of geometric development. The study identifies some problematic test items as they only require knowledge of a specific aspect of geometry instead of testing geometric reasoning. In terms of the Van Hiele theory, the Rasch analyses identified as problematic some items about class inclusion, an issue which has also been raised in other studies.http://www.tandfonline.com/loi/rmse202016-01-31hb201

Investigating the treatment of missing data in an Olympiad-type test – the case of the selection validity in the South African Mathematics Olympiad

The purpose of the South African Mathematics Olympiad is to generate interest in mathematics and to identify the most talented mathematical minds. Our focus is on how the handling of missing data affects the selection of the ‘best’ contestants. Two approaches handling missing data, applying the Rasch model, are described. The issue of guessing is investigated through a tailored analysis. We present two microanalyses to illustate how missing data may impact selection; the first investigates groups of contestants that may miss selection under particular conditions; the second focuses on two contestants each of whom answer 14 items correctly. This comparison raises questions about the proportion of correct to incorrect answers. Recommendations are made for future scoring of the test, which include reconsideration of negative marking and weighting as well as considering the inclusion of 150 or 200 contestants as opposed to 100 contestants for participation in the final round.Our respected and loved colleague, Tim Dunne, sadly passed away in a car accident after this article had been submitted for publication. We acknowledge his valuable contribution not only to the article but also to the field of Rasch measurement theory.http://www.pythagoras.org.zaam2016Science, Mathematics and Technology Educatio

Measuring the combinatorial expression of solute transporters and metalloproteinases transcripts in colorectal cancer

Published: 19 August 2009Background: It was hypothesised that colorectal cancer (CRC) could be diagnosed in biopsies by measuring the combined expression of a small set of well known genes. Genes were chosen based on their role in either the breakdown of the extracellular matrix or with changes in cellular metabolism both of which are associated with CRC progression. Findings: Gene expression data derived from quantitative real-time PCR for the solute transporter carriers (SLCs) and the invasion-mediating matrix metalloproteinases (MMPs) were examined using a Linear Descriminant Analysis (LDA). The combination of MMP-7 and SLC5A8 was found to be the most predictive of CRC. Conclusion: A combinatorial analysis technique is an effective method for both furthering our understanding on the molecular basis of some aspects of CRC, as well as for leveraging well defined cancer-related gene sets to identify cancer. In this instance, the combination of MMP-7 and SLC5A8 were optimal for identifying CRC.Caroline A. Kerr, Robert Dunne, Barney M. Hines, Michelle Zucker, Leah Cosgrove, Andrew Ruszkiewicz, Trevor Lockett and Richard Hea

Improving Characterization of Understudied Human Microbiomes Using Targeted Phylogenetics.

Whole-genome bacterial sequences are required to better understand microbial functions, niche-specific bacterial metabolism, and disease states. Although genomic sequences are available for many of the human-associated bacteria from commonly tested body habitats (e.g., feces), as few as 13% of bacterium-derived reads from other sites such as the skin map to known bacterial genomes. To facilitate a better characterization of metagenomic shotgun reads from underrepresented body sites, we collected over 10,000 bacterial isolates originating from 14 human body habitats, identified novel taxonomic groups based on full-length 16S rRNA gene sequences, clustered the sequences to ensure that no individual taxonomic group was overselected for sequencing, prioritized bacteria from underrepresented body sites (such as skin and respiratory and urinary tracts), and sequenced and assembled genomes for 665 new bacterial strains. Here, we show that addition of these genomes improved read mapping rates of Human Microbiome Project (HMP) metagenomic samples by nearly 30% for the previously underrepresented phylum Fusobacteria, and 27.5% of the novel genomes generated here had high representation in at least one of the tested HMP samples, compared to 12.5% of the sequences in the public databases, indicating an enrichment of useful novel genomic sequences resulting from the prioritization procedure. As our understanding of the human microbiome continues to improve and to enter the realm of therapy developments, targeted approaches such as this to improve genomic databases will increase in importance from both an academic and a clinical perspective.IMPORTANCE The human microbiome plays a critically important role in health and disease, but current understanding of the mechanisms underlying the interactions between the varying microbiome and the different host environments is lacking. Having access to a database of fully sequenced bacterial genomes provides invaluable insights into microbial functions, but currently sequenced genomes for the human microbiome have largely come from a limited number of body sites (primarily feces), while other sites such as the skin, respiratory tract, and urinary tract are underrepresented, resulting in as little as 13% of bacterium-derived reads mapping to known bacterial genomes. Here, we sequenced and assembled 665 new bacterial genomes, prioritized from a larger database to select underrepresented body sites and bacterial taxa in the existing databases. As a result, we substantially improve mapping rates for samples from the Human Microbiome Project and provide an important contribution to human bacterial genomic databases for future studies

Meals for the dead:investigating Romano-British accessory vessels in burials using organic residue analysis

Accessory vessels, including platters, dishes, beakers, flagons, jars, and amphorae, are a common feature of Romano-British burials, raising questions as to their provenance; for example, were such vessels recycled from the domestic sphere or made specially for funerary purposes? Furthermore, uncertainty surrounds their purpose: did they contain foods for the deceased, possibly for their final journey to the underworld? Interestingly, organic residue analysis of vessels from Baginton, a site adjacent to The Lunt fort, Coventry, an early (mid to late first century) Roman military cremation cemetery did not yield evidence for food offerings and may have reflected the use of seconds or damaged vessels in burials, perhaps to provide a symbolic meal. In contrast, here we provide, for the first time, direct chemical and isotopic evidence for ‘meals for the dead’, comprising mainly dairy products, often mixed with leafy plants, extracted from somewhat unusual accessory vessels found in a small, enclosed inhumation cemetery, perhaps associated with a family group, which dates to the late (third to late fourth century, or early fifth century A.D) in urban Canterbury. Thus, we can confirm that accessory vessels found in later Romano-British burials were, in this instance, used in the laying out of funerary meals, presumably to nourish the soul on the journey to the underworld. These preliminary insights on vessel use and burial practices across the span of the Roman occupation of Britain thus provide a strong hint at the diversity of Roman burial practices