Optimizing the representation of orientation preference maps in visual cortex

The colorful representation of orientation preference maps in primary visual cortex has become iconic. However, the standard representation is misleading because it uses a color mapping to indicate orientations based on the HSV (hue, saturation, value) color space, for which important perceptual features such as brightness, and not just hue, vary among orientations. This means that some orientations stand out more than others, conveying a distorted visual impression. This is particularly problematic for visualizing subtle biases caused by slight overrepresentation of some orientations due to, for example, stripe rearing. We show that displaying orientation maps with a color mapping based on a slightly modified version of the HCL (hue, chroma, lightness) color space, so that primarily only hue varies between orientations, leads to a more balanced visual impression. This makes it easier to perceive the true structure of this seminal example of functional brain architecture

Reversing the eyes and reverse perspectives:Pseudoscopic amplification of reverspectives

Stereoscopic photographs of works in reverse perspective do not reveal their three-dimensional structure whereas pseudoscopic photographs enhance the apparent depth effects.</p

Nonparametric Sparsification of Complex Multiscale Networks

Many real-world networks tend to be very dense. Particular examples of interest arise in the construction of networks that represent pairwise similarities between objects. In these cases, the networks under consideration are weighted, generally with positive weights between any two nodes. Visualization and analysis of such networks, especially when the number of nodes is large, can pose significant challenges which are often met by reducing the edge set. Any effective “sparsification” must retain and reflect the important structure in the network. A common method is to simply apply a hard threshold, keeping only those edges whose weight exceeds some predetermined value. A more principled approach is to extract the multiscale “backbone” of a network by retaining statistically significant edges through hypothesis testing on a specific null model, or by appropriately transforming the original weight matrix before applying some sort of threshold. Unfortunately, approaches such as these can fail to capture multiscale structure in which there can be small but locally statistically significant similarity between nodes. In this paper, we introduce a new method for backbone extraction that does not rely on any particular null model, but instead uses the empirical distribution of similarity weight to determine and then retain statistically significant edges. We show that our method adapts to the heterogeneity of local edge weight distributions in several paradigmatic real world networks, and in doing so retains their multiscale structure with relatively insignificant additional computational costs. We anticipate that this simple approach will be of great use in the analysis of massive, highly connected weighted networks

Fluconazole-Associated Birth Defects: A Comprehensive Review

Background: The August 2013 publication of a large historical cohort study in the New England Journal of Medicine has reignited interest in the potential teratogenic effects of fluconazole when used in pregnant females. Fluconazole is an effective and commonly-utilized antifungal medication. Thus, maternal and fetal exposure to fluconazole is expected in the general population, and pharmacists are expected to counsel patients regarding any risks to their prescribed treatment. Methods: A literature review of all published literature indexed to PubMed (January 1966 to October 2013) and International Pharmaceutical Abstracts (January 1975 to October 2013) including fluconazole and teratogenic effects and published in the English language was conducted. Results: Fourteen publications were included for analysis including case reports (n=7), cross-sectional research (n=2), and historical cohort studies (n=5). Conclusion: There appears to be little to no fetal risk resulting from a single dose or short duration antifungal therapy with fluconazole. However, prolonged high-dose fluconazole therapy has increased potential to confer teratogenic effects. In those cases, the risks of such therapy should be weighed against potential benefits

A multivariant recall-by-genotype study of the metabolomic signature of BMI

OBJECTIVE: This study estimated the effect of BMI on circulating metabolites in young adults using a recall‐by‐genotype study design. METHODS: A recall‐by‐genotype study was implemented in the Avon Longitudinal Study of Parents and Children. Samples from 756 participants were selected for untargeted metabolomics analysis based on low versus high genetic liability for higher BMI defined by a genetic risk score (GRS). Regression analyses were performed to investigate associations between BMI GRS group and relative abundance of 973 metabolites. RESULTS: After correction for multiple testing, 29 metabolites were associated with BMI GRS group. Bilirubin was among the most strongly associated metabolites, with reduced levels measured in individuals in the high‐BMI GRS group (β = −0.32, 95% CI: −0.46 to −0.18, Benjamini‐Hochberg adjusted p = 0.005). This study observed associations between BMI GRS group and the levels of several potentially diet‐related metabolites, including hippurate, which had lower mean abundance in individuals in the high‐BMI GRS group (β = −0.29, 95% CI: −0.44 to −0.15, Benjamini‐Hochberg adjusted p = 0.008). CONCLUSIONS: Together with existing literature, these results suggest that a genetic predisposition to higher BMI captures differences in metabolism leading to adiposity gain. In the absence of prospective data, separating these effects from the downstream consequences of weight gain is challenging

Randomized controlled trial to study plaque inhibition in calcium sodium phosphosilicate dentifrices

Objectives To evaluate the effect of three calcium sodium phosphosilicate (CSPS)/sodium monofluorophosphate containing dentifrices, compared to positive and negative controls on plaque re-growth in a non-brushing model, after 4 days of twice daily use, as determined by plaque area and Turesky plaque index (TPI). Methods This was an exploratory, single-centre, examiner-blind, randomised, controlled, five treatment period, crossover, plaque re-growth study, with supervised use of study products. Twenty-three healthy adult volunteers were randomized to receive experimental 5% CSPS dentifrice; two marketed 5% CSPS dentifrices; active comparator mouthrinse and negative control dentifrice. At the start of each treatment period, zero plaque was established by dental prophylaxis and study products were dispensed as either dentifrice slurries or mouthrinse, twice daily for the next 4 days. No other forms of oral hygiene were permitted. After 96 h, supra-gingival plaque was determined by plaque area (direct entry, planimetric method) and TPI. Changes from zero plaque were analysed. Results For both measures, plaque re-growth at 96 h was significantly lower following treatment with active comparator mouthrinse and significantly higher following treatment with the experimental 5% CSPS dentifrice, compared to all other treatments. There were no statistically significant differences between the three other treatments, except between the marketed 5% CSPS dentifrices, for overall plaque area. Conclusions The comparator mouthwash was significantly more effective at preventing plaque accumulation than the dentifrice slurries. The three marketed dentifrices contained sodium lauryl sulphate and were more effective at reducing plaque re-growth than the experimental dentifrice formulated with a tegobetaine/adinol surfactant system. Clinical relevance The CSPS containing dentifrices tested in this study showed no significant chemical-therapeutic anti-plaque benefits compared to a negative control dentifrice. However, sodium lauryl sulphate-containing dentifrices controlled plaque more effectively than a tegobetaine/adinol-containing CSPS dentifrice suggesting that the impact of surfactant selection on anti-plaque activity of formulations warrants further investigation

Zygote morphogenesis but not the establishment of cell polarity in plasmodium berghei Is controlled by the small GTPase, RAB11A

Plasmodium species are apicomplexan parasites whose zoites are polarized cells with a marked apical organisation where the organelles associated with host cell invasion and colonization reside. Plasmodium gametes mate in the mosquito midgut to form the spherical and presumed apolar zygote that morphs during the following 24 hours into a polarized, elongated and motile zoite form, the ookinete. Endocytosis-mediated protein transport is generally necessary for the establishment and maintenance of polarity in epithelial cells and neurons, and the small GTPase RAB11A is an important regulator of protein transport via recycling endosomes. PbRAB11A is essential in blood stage asexual of Plasmodium. Therefore, a promoter swap strategy was employed to down-regulate PbRAB11A expression in gametocytes and zygotes of the rodent malaria parasite, Plasmodium berghei which demonstrated the essential role of RAB11A in ookinete development. The approach revealed that lack of PbRAB11A had no effect on gamete production and fertility rates however, the zygote to ookinete transition was almost totally inhibited and transmission through the mosquito was prevented. Lack of PbRAB11A did not prevent meiosis and mitosis, nor the establishment of polarity as indicated by the correct formation and positioning of the Inner Membrane Complex (IMC) and apical complex. However, morphological maturation was prevented and parasites remained spherical and immotile and furthermore, they were impaired in the secretion and distribution of microneme cargo. The data are consistent with the previously proposed model of RAB11A endosome mediated delivery of plasma membrane in Toxoplasma gondii if not its role in IMC formation and implicate it in microneme function

A framework for research into continental ancestry groups of the UK Biobank

BACKGROUND: The UK Biobank is a large prospective cohort, based in the UK, that has deep phenotypic and genomic data on roughly a half a million individuals. Included in this resource are data on approximately 78,000 individuals with “non-white British ancestry.” While most epidemiology studies have focused predominantly on populations of European ancestry, there is an opportunity to contribute to the study of health and disease for a broader segment of the population by making use of the UK Biobank’s “non-white British ancestry” samples. Here, we present an empirical description of the continental ancestry and population structure among the individuals in this UK Biobank subset. RESULTS: Reference populations from the 1000 Genomes Project for Africa, Europe, East Asia, and South Asia were used to estimate ancestry for each individual. Those with at least 80% ancestry in one of these four continental ancestry groups were taken forward (N = 62,484). Principal component and K-means clustering analyses were used to identify and characterize population structure within each ancestry group. Of the approximately 78,000 individuals in the UK Biobank that are of “non-white British” ancestry, 50,685, 6653, 2782, and 2364 individuals were associated to the European, African, South Asian, and East Asian continental ancestry groups, respectively. Each continental ancestry group exhibits prominent population structure that is consistent with self-reported country of birth data and geography. CONCLUSIONS: Methods outlined here provide an avenue to leverage UK Biobank’s deeply phenotyped data allowing researchers to maximize its potential in the study of health and disease in individuals of non-white British ancestry. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40246-022-00380-5

Proton Aurora on Mars: A Dayside Phenomenon Pervasive in Southern Summer

We present observations of proton aurora at Mars made using the Imaging UltraViolet Spectrograph (IUVS) onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. Martian proton aurora display a prominent intensity enhancement in the hydrogen Lyman‐alpha (121.6 nm) emission between ~110 and 150 km altitude. Using altitude‐intensity profiles from periapsis limb scan data spanning nearly two Martian years, we create a comprehensive database of proton aurora and characterize their phenomenology. Due to Mars\u27 lack of a global dipole magnetic field, Martian proton aurora are expected to form on the dayside via electron stripping and charge exchange between solar wind protons and the neutral corona. We observe proton aurora in ~14% of dayside periapsis profiles (with notable seasonal variability), making proton aurora the most commonly observed type of aurora at Mars. We determine that the primary factors influencing proton aurora occurrence rates are solar zenith angle and season. The highest proton aurora occurrence rates are at low solar zenith angles on the Mars dayside, consistent with known formation processes. Proton aurora have highest emission enhancements, peak intensities, peak altitudes, and occurrence rates (nearing 100%) around southern summer solstice. This time period corresponds with the seasonal inflation of the neutral lower atmosphere, the onset of Martian dust storm season, seasonally increased coronal hydrogen column densities, and higher atmospheric temperature and solar wind flux following perihelion. The results of our study provide a new understanding of the primary factors influencing proton aurora, and the long‐term variability of these phenomena as observed over multiple Mars years