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Biology subjects

Kumar, M. D.

Publications and source records attributed to Kumar, M. D..

2 recordsLinked to original sources

A binocular perception deficit characterizes prey pursuit in developing mice

The mouse continues to be one of the most powerful models in which to address the molecular and cellular mechanisms underlying mammalian visual system development. In particular, integration of binocular information at the cellular level has long been studied in specific regions of the mouse visual cortex to gain mechanistic insight into the development of vision. However, we lack an understanding of the development of the visual perceptions themselves in mice and other species that might rely on successful binocular integration. Further, the superior colliculus also processes binocular input and it remains unclear how early visual experience differentially impacts activity in this brain area during behavior. To address these major outstanding questions, we quantified the natural visually-guided behavior of postnatal day 21 (P21) and adult mice using a live prey capture assay and a computerized-spontaneous perception of visual objects tasks (C-SPOT). Analysis of both behavioral assays revealed robust and specific binocular visual field processing deficits in P21 mice as compared to adults. In addition, c-Fos expression in the anterior region of the superior colliculus (SC), the region that would process stimuli located in the binocular visual field, was highly different between P21 mice and adults after C-SPOT. We thus exploited a natural visual pursuit behavior and C-SPOT to provide the first demonstration of a specific visual perception deficit related to binocular integration in developing mice. HighlightsO_LIJuvenile (P21) mice robustly investigate live insects C_LIO_LIInsect pursuit behavior relying on binocular vision is immature in P21 mice C_LIO_LIVisually-induced arrest responses are similar between P21 and adult mice. C_LIO_LIEthologically-relevant visual experience differentially increases c-Fos expression in the superior colliculus of juveniles versus adults. C_LI

animal behavior and cognition↗

A Novel Uranium Bioremediation Approach using Radioresistance Deinocoocus radiodurans Biofilm

Deinococcus radiodurans, is the most radiation tolerant organism ever known, it has gained importance in recent years as a potential candidate for bioremediation of heavy metals, especially radioactive ones. This study investigates the efficiency of a recombinant D. radiodurans (DR1-bf+) strain with an ability to form biofilm for uranium remediation. The modified Arsenazo III dye method was used to estimate the uranium concentration. Uranyl nitrate aqueous solution is generated during the operation of nuclear fuel reprocessing. The D. radiodurans biofilm (DR1-bf+) grown in the presence of 20 mM Ca2+ showed remarkable ability of uranyl ion removal. DR1-bf+ (+Ca2+) biofilm removed [~]75 {+/-} 2% of 1000 mg/L uranium within 30 minutes post treatment from uranyl nitrate aqueous solution. U removal rate was also found to be directly proportional to biofilm age. This study discusses the ability of D. radiodurans biofilm in uranium removal.\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC=\"FIGDIR/small/503896_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (34K):\norg.highwire.dtl.DTLVardef@1905462org.highwire.dtl.DTLVardef@93f7f6org.highwire.dtl.DTLVardef@7c6d1dorg.highwire.dtl.DTLVardef@dfb11f_HPS_FORMAT_FIGEXP M_FIG Graphical abstract C_FIG

microbiology↗