Temporal dynamics of the neural representation of hue and luminance contrast

Hue and luminance contrast are the most basic visual features, emerging in early layers of convolutional neural networks trained to perform object categorization. In human vision, the timing of the neural computations that extract these features, and the extent to which they are determined by the same or separate neural circuits, is unknown. We addressed these questions using multivariate analyses of human brain responses measured with magnetoencephalography. We report four discoveries. First, it was possible to decode hue tolerant to changes in luminance contrast, and luminance contrast tolerant to changes in hue, consistent with the existence of separable neural mechanisms for these features. Second, the decoding time course for luminance contrast peaked 16-24 ms before hue and showed a more prominent secondary peak corresponding to decoding of stimulus cessation. These results are consistent with the idea that the brain uses luminance contrast as an updating signal to separate events within the constant stream of visual information. Third, neural representations of hue generalized to a greater extent across time, providing a neural correlate of the preeminence of hue over luminance contrast in perceptual grouping and memory. Finally, decoding of luminance contrast was more variable across participants for hues associated with daylight (orange and blue) than for anti-daylight (green and pink), suggesting that color-constancy mechanisms reflect individual differences in assumptions about natural lighting

Rapid topography mapping of scalar fields: Large molecular clusters

The following article appeared in Journal of Chemical Physics 137.7 (2012): 074116 and may be found at http://scitation.aip.org/content/aip/journal/jcp/137/7/10.1063/1.4746243An efficient and rapid algorithm for topography mapping of scalar fields, molecular electron density (MED) and molecular electrostatic potential (MESP) is presented. The highlight of the work is the use of fast function evaluation by Deformed-atoms-in-molecules (DAM) method. The DAM method provides very rapid as well as sufficiently accurate function and gradient evaluation. For mapping the topography of large systems, the molecular tailoring approach (MTA) is invoked. This new code is tested out for mapping the MED and MESP critical points (CP's) of small systems. It is further applied to large molecular clusters viz. (H 2O) 25, (C 6H 6) 8 and also to a unit cell of valine crystal at MP26-31G(d) level of theory. The completeness of the topography is checked by extensive search as well as applying the Poincaré-Hopf relation. The results obtained show that the DAM method in combination with MTA provides a rapid and efficient route for mapping the topography of large molecular systemsAuthors thank the Center for Development of Advanced Computing (C-DAC), Pune for financial and computational support. S.R.G. is grateful to the Department of Science and Technology (DST) for the award of J. C. Bose National Fellowship. R. López acknowledges partial funding from the CAM (S2009_PPQ-1545, LIQUORGAS) and MICINN (CTQ2010-19232). Authors are also thankful to Dr. Graeme M. Day, University of Cambridge, for providing the coordinates of unit cell of valine crystal and to Dr. V. Subramanian, CLRI, Chennai for providing some test run

A Comparison of Culture- and PCR-Based Methods to Detect Six Major Non-O157 Serogroups of Shiga Toxin-Producing Escherichia coli in Cattle Feces

Citation: Noll, L. W., Shridhar, P. B., Dewsbury, D. M., Shi, X. R., Cernicchiaro, N., Renter, D. G., & Nagaraja, T. G. (2015). A Comparison of Culture- and PCR-Based Methods to Detect Six Major Non-O157 Serogroups of Shiga Toxin-Producing Escherichia coli in Cattle Feces. Plos One, 10(8), 12. doi:10.1371/journal.pone.0135446Culture-based methods to detect the six major non-O157 (O26, O45, O103, O111, O121 and O145) Shiga toxin-producing E. coli (STEC) are not well established. Our objectives of this study were to develop a culture-based method to detect the six non-O157 serogroups in cattle feces and compare the detection with a PCR method. Fecal samples (n = 576) were collected in a feedlot from 24 pens during a 12-week period and enriched in E. coli broth at 40 degrees C for 6 h. Enriched samples were subjected to immunomagnetic separation, spread-plated onto a selective chromogenic medium, and initially pooled colonies, and subsequently, single colonies were tested by a multiplex PCR targeting six serogroups and four virulence genes, stx1, stx2, eae, and ehxA (culture method). Fecal suspensions, before and after enrichment, were also tested by a multiplex PCR targeting six serogroups and four virulence genes (PCR method). There was no difference in the proportions of fecal samples that tested positive (74.3 vs. 77.4%) for one or more of the six serogroups by either culture or the PCR method. However, each method detected one or more of the six serogroups in samples that were negative by the other method. Both culture method and PCR indicated that O26, O45, and O103 were the dominant serogroups. Higher proportions (P < 0.05) of fecal samples were positive for O26 (44.4 vs. 22.7%) and O121 (22.9 vs. 2.3%) serogroups by PCR than by the culture method. None of the fecal samples contained more than four serogroups. Only a small proportion of the six serogroups (23/640; 3.6%) isolated carried Shiga toxin genes. The culture method and the PCR method detected all six serogroups in samples negative by the other method, highlighting the importance of subjecting fecal samples to both methods for accurate detection of the six non-O157 STEC in cattle feces

Better root:shoot ratio conferred enhanced harvest index in transgenic groundnut overexpressing the rd29A:DREB1A gene under intermittent drought stress in an outdoor lysimetric dry-down trial

An outdoor confined trial was conducted during the postrainy season of 2009 for physiological evaluation of induced drought tolerance in transgenic plants of groundnut variety JL 24 overexpressing a transcription factor, DREB1A driven by the stress-inducible promoter of the rd29A gene, both from Arabidopsis thaliana. Lysimetric system was used for growing the plants, where intermittent drought stress was imposed at mid-flowering and peak pod-filling stages of the crop, by subjecting plants to a cycle of drying and re-watering. The lysimetric system facilitated complete recovery of roots, thereby, facilitating studies on variations in the root:shoot ratio induced across the genotypes under controlled wellwatered (WW) and imposed drought stress (DS) conditions. Under DS the root:shoot ratio showed a significant (P <0.005) positive correlation with pod yield and harvest index (HI), reflecting clearly the better performance of two transgenic events GNRD11 and GNRD33 than the untransformed variety JL 24. The transgenic event GNRD11, in particular, showed enhanced HI along with significantly higher (P <0.05) seed yield that was 22% and 25% higher than JL 24 and the elite breeding groundnut cultivar ICGV 86031, respectively. Better HI in these transgenic events, when compared to the untransformed control, was mainly due to the effective partitioning of the accumulated biomass, more towards roots and pods while relatively less towards shoot biomass, leading to higher root:shoot ratio and better yield, also suggesting better water use efficiency in the former compared to the latter

ALL-Digital Baseband 65nm PLL/FPLL Clock Multiplier Using 10-Cell Library

PLLs for clock generation are essential for modern circuits, to generate specialized frequencies for many interfaces and high frequencies for chip internal operation. These circuits depend on analog circuits and careful tailoring for each new process, and making them fault tolerant is an incompletely solved problem. Until now, all digital PLLs have been restricted to sampled data DSP techniques and not available for the highest frequency baseband applications. This paper presents the design and preliminary evaluation of an all-digital baseband technique built entirely with an easily portable 10-cell digital library. The library is also described, as it aids in research and low volume design porting to new processes. The advantages of the digital approach are the wide variety of techniques available to give varying degrees of fault tolerance, and the simplicity of porting the design to new processes, even to exotic processes that may not have analog capability. The only tuning parameter is digital gate delay. An all-digital approach presents unique problems and standard analog loop stability design criteria cannot be directly used. Because of the quantization of frequency, there is effectively infinite gain for very small loop error feedback. The numerically controlled oscillator (NCO) based on a tapped delay line cannot be reliably updated while a pulse is active in the delay line, and ordinarily does not have enough frequency resolution for a low-jitter output

Diagnosis of Oral Cancers by Targeting VPAC Receptors: Preliminary Report

Introduction: Oral cancer is a major health problem. The study of exfoliative cytology material helps in the differentiation of premalignant and malignant alterations of oral lesions. The objective of this study was to assess the feasibility of detecting oral cancer by targeting genomic VPAC (combined vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide) receptors expressed on malignant oral cancer cells. Patients & methods: All patients with suspected oral cavity cancers/lesions formed the study group. The samples from the oral cavity lesion or suspicious area were collected with a cytology brush. The harvested material was examined for malignant cells by 1. the standard PAP stain and 2. targeting the VPAC receptors on the cell surface using a fluorescent microscope. Similarly, malignant cells were identified from cells shed in oral gargles. Results: A total of 60 patients with oral lesions were included in the study. The histopathological diagnosis was squamous cell carcinoma in 30 of these. The VPAC receptor positivity both on the brush cytology staining as well oral gargle staining was more sensitive than the brush cytology PAP staining. The accuracy of the various techniques was as follows, brush cytology PAP staining at 86.67%, brush cytology VPAC staining at 91.67% and oral gargle VPAC staining at 95%. Conclusions: This preliminary study validates our belief that malignant cells in the saliva can be identified by targeting the VPAC receptors. The test is simple, easy, non-invasive and reliable in the detection of oral cancers

A novel accessory muscle in the flexor compartment of anterior forearm inserting into the tenosynovium of the flexor pollicis longus

A common variant of accessory muscles in the anterior forearm is the Gantzer’s muscle (GM). GM arises as a muscle belly from flexor digitorum superficialis (FDS) or ulnar coronoid process to merge distally with the flexor pollicis longus (FPL) muscle. In the present case report, we describe a novel accessory muscle in the flexor compartment of the forearm. The proximal attachment was tendinous and came from three sources: FDS muscle, ulnar coronoid process, and the medial aspect of the proximal radius. The distal tendon of the novel accessory muscle ran parallel to FPL, passed through the carpal tunnel, and entered the palmar aspect of the hand. In the hand, the tendon thinned out and blended with the tenosynovium of the FPL, contributing to the sheath around the FPL tendon. This accessory muscle of the FPL is comparable to the frequently documented Gantzer muscle (GM); however, the present case exhibited fundamental nuances that distinguish it from the previously described iterations of the GM in the following ways: 1) The novel accessory muscle is tendinous from its proximal origin and throughout the upper one-third of the forearm, and one component of its origin arose from the medial aspect of the radius. Gantzer muscles with an origin on the radius have not been previously reported. 2) In the middle one-third, the tendinous proximal attachment transitioned to a muscle belly that passed through the carpal tunnel and entered the hand. 3) In the hand, the novel tendon widened, thinned, and merged with the tenosynovium of the FPL. Accessory muscles are a common finding in the anterior forearm during cadaveric dissection. In patients, they can be the cause of neuropathies due to compression of the anterior interosseous nerve. Awareness of variations is also important for clinicians who examine the forearm and hand, as well as hand and surgeons

Multicomponent analysis of the tumour microenvironment reveals low CD8 T cell number, low stromal caveolin-1 and high tenascin-C and their combination as significant prognostic markers in non-small cell lung cancer

The complex interplay of the tumour microenvironment (TME) and its role in disease progression and response to therapy is poorly understood. The majority of studies to date focus on individual components or molecules within the TME and so lack the power correlative analysis. Here we have performed a multi-parameter analysis of the TME in 62 resectable non-small cell lung cancer (NSCLC) specimens detailing number and location of immune infiltrate, assessing markers of cancer-associated fibroblasts, caveolin-1 and tenascin-C, and correlating with clinicopathological details, as well as markers of disease progression such as epithelial-to-mesenchymal transition (EMT). The influence of individual parameters on overall survival was determined in univariate and multivariate analysis and the combination of risk factors and interplay between components analysed. Low numbers of CD8 T cells, low stromal levels of caveolin-1 or high levels of tenascin-C were significant prognostic markers of decreased overall survival in both univariate and multivariate analysis. Patients with two or more risk factors had dramatically reduced overall survival and those with all three a median survival of just 7.5 months. In addition, low levels of tumour E-cadherin correlated with reduced immune infiltrate into the tumour nests, possibly linking EMT to the avoidance of CD8 T cell control. The multicomponent approach has allowed identification of the dominant influences on overall survival, and exploration of the interplay between different components of the TME in NSCLC

Nanoceria: A Rare-Earth Nanoparticle as a Novel Anti-Angiogenic Therapeutic Agent in Ovarian Cancer

Ovarian cancer (OvCa) is the fifth most common cause of death from all cancers among women in United Sates and the leading cause of death from gynecological malignancies. While most OvCa patients initially respond to surgical debulking and chemotherapy, 75% of patients later succumb to the disease. Thus, there is an urgent need to test novel therapeutic agents to counteract the high mortality rate associated with OvCa. In this context, we have developed and engineered Nanoceria (NCe), nanoparticles of cerium oxide, possessing anti-oxidant properties, to be used as a therapeutic agent in OvCa. We show for the first time that NCe significantly inhibited production of reactive oxygen species (ROS) in A2780 cells, attenuated growth factor (SDF1, HB-EGF, VEGF(165) and HGF) mediated cell migration and invasion of SKOV3 cells, without affecting the cell proliferation. NCe treatment also inhibited VEGF165 induced proliferation, capillary tube formation, activation of VEGFR2 and MMP2 in human umbilical vascular endothelial cells (HUVEC). NCe (0.1 mg/kg body weigh) treatment of A2780 ovarian cancer cells injected intra-peritoneally in nude mice showed significant reduction (p \u3c 0.002) in tumor growth accompanied by decreased tumor cell proliferation as evident from reduced tumor size and Ki67 staining. Accumulation of NCe was found in tumors isolated from treated group using transmission electron microscopy (TEM) and inductively coupled plasma mass spectroscopy (ICP-MS). Reduction of the tumor mass was accompanied by attenuation of angiogenesis, as observed by reduced CD31 staining and specific apoptosis of vascular endothelial cells. Collectively, these results indicate that cerium oxide based NCe is a novel nanoparticle that can potentially be used as an anti-angiogenic therapeutic agent in ovarian cancer