Anomaly Detection in Paleoclimate Records using Permutation Entropy

Permutation entropy techniques can be useful in identifying anomalies in paleoclimate data records, including noise, outliers, and post-processing issues. We demonstrate this using weighted and unweighted permutation entropy of water-isotope records in a deep polar ice core. In one region of these isotope records, our previous calculations revealed an abrupt change in the complexity of the traces: specifically, in the amount of new information that appeared at every time step. We conjectured that this effect was due to noise introduced by an older laboratory instrument. In this paper, we validate that conjecture by re-analyzing a section of the ice core using a more-advanced version of the laboratory instrument. The anomalous noise levels are absent from the permutation entropy traces of the new data. In other sections of the core, we show that permutation entropy techniques can be used to identify anomalies in the raw data that are not associated with climatic or glaciological processes, but rather effects occurring during field work, laboratory analysis, or data post-processing. These examples make it clear that permutation entropy is a useful forensic tool for identifying sections of data that require targeted re-analysis---and can even be useful in guiding that analysis.Comment: 15 pages, 7 figure

A category-specific advantage for numbers in verbal short-term memory: Evidence from semantic dementia

This study explored possible reasons for the striking difference between digit span and word span in patients with semantic dementia. Immediate serial recall (ISR) of number and non-number words was examined in four patients. For every case, the recall of single-digit numbers was normal whereas the recall of non-number words was impaired relative to controls. This difference extended to multi-digit numbers, and remained even when frequency, imageability, word length, set size and size of semantic category were matched for the numbers and words. The advantage for number words also applied to the patients' reading performance. Previous studies have suggested that semantic memory plays a critical role in verbal short-term memory (STM) and reading: patients with semantic dementia show superior recall and reading of words that are still relatively well known compared to previously known but now semantically degraded words. Additional assessments suggested that this semantic locus was the basis of the patients' category-specific advantage for numbers. Comprehension was considerably better for number than non-number words. Number knowledge may be relatively preserved in semantic dementia because the cortical atrophy underlying the condition typically spares the areas of the parietal lobes thought to be crucial in numerical cognition but involves the inferolateral temporal-lobes known to support general conceptual knowledge. © 2003 Elsevier Ltd. All rights reserved

Quantification of MUCIN 1, cell surface associated and MUCIN16, cell surface associated proteins in tears and conjunctival epithelial cells collected from postmenopausal women

Srinivasan, S., Heynen, M. L., Martell, E., Ritter, R., Jones, L., & Senchyna, M. (2013). Quantification of MUCIN 1, cell surface associated and MUCIN16, cell surface associated proteins in tears and conjunctival epithelial cells collected from postmenopausal women. Molecular Vision, 19, 970–979.Purpose: To quantify the expression of mucin 1, cell surface associated (MUC1) and mucin 16, cell surface associated (MUC16) proteins and messenger ribonucleic acid (mRNA) in a cohort of postmenopausal women (PMW), to explore the relationship between mucin expression, dry eye symptomology, and tear stability.Methods: Thirty-nine healthy PMW (>50 years of age) were enrolled in this study. No specific inclusion criteria were used to define dry eye; instead, a range of subjects were recruited based on responses to the Allergan Ocular Surface Disease Index (OSDI) questionnaire and tear stability measurements as assessed by non-invasive tear breakup time (NITBUT). Tears were collected from the inferior tear meniscus using a disposable glass capillary tube, and total RNA and total protein were isolated from conjunctival epithelial cells collected via impression cytology. Expression of membrane-bound and soluble MUC1 and MUC16 were quantified with western blotting, and expression of MUC1 and MUC16 mRNA was assessed with real-time PCR.Results: OSDI responses ranged from 0 to 60, and NITBUT ranged from 18.5 to 2.9 s. Only two statistically significant correlations were found: soluble MUC16 protein concentration and MUC16 mRNA expression with OSDI vision related (−0.47; p=0.01) and ocular symptom (0.39; p=0.02) subscores, respectively. Post hoc exploratory analysis on absolute expression values was performed on two subsets of subjects defined as asymptomatic (OSDI ≤6, n=12) and moderate to severe symptomatic (OSDI ≥20, n=12). The only significant difference between the two subgroups was a significant reduction in MUC16 mRNA expression found in the symptomatic dry eye group (1.52±1.19 versus 0.57±0.44; p=0.03).Conclusions: A broad exploration of mucin expression compared to either a sign (NITBUT) or symptoms of dry eye failed to reveal compelling evidence supporting a significant relationship, other than a potential association between MUC16 with specific symptoms. Furthermore, comparison of mucin protein and expression levels between the asymptomatic and moderate to severe symptomatic subgroups revealed only one significant difference, a reduction in MUC16 mRNA expression in the symptomatic subgroup.Funding for this study was provided by Alcon Research Ltd and the Natural Sciences and Engineering Research Council of Canada (NSERC)

Developmental Basis of Pronephric Defects in Xenopus Body Plan Phenotypes

AbstractWe have used monoclonal antibodies that recognize the pronephric tubules or pronephric duct to explore the induction of the embryonic kidney in developing Xenopus embryos. Morphogenesis of the pronephros was examined in UV-ventralized and lithium-dorsalized embryos. We find that the pronephric tubules are present in all but the strongest UV-induced phenotypes, but absent from relatively moderate lithium phenotypes. Interestingly the pronephric duct, which develops from the ventroposterior portion of the pronephric anlage, is missing from more of the mild UV phenotypes than are pronephric tubules. The loss of the capacity to form pronephroi in UV-ventralized embryos is caused by the loss of tissues capable of inducing the pronephric mesoderm, as marginal zone explants from ventralized embryos are still competent to respond to pronephric-inductive signals. Explant recombination experiments indicate that the tissue responsible for both the loss of pronephroi in UV-ventralized embryos and the induction of pronephroi during normal development is the anterior somites. The absence of pronephroi in relatively mild lithium phenotypes has a developmental basis different from that of the UV phenotype, as explants from lithium-treated embryos are effective inducers of pronephroi in recombinants with competent mesoderm, even though they themselves do not form pronephroi in isolation. Together these data indicate that dorsal tissues, especially the anterior somites, are responsible for the establishment of the intermediate mesoderm and the induction of the embryonic kidneys and that even mild dorsalization destroys the capacity to form cells competent to receive this signal