Human-in-the-Loop SLAM

Building large-scale, globally consistent maps is a challenging problem, made more difficult in environments with limited access, sparse features, or when using data collected by novice users. For such scenarios, where state-of-the-art mapping algorithms produce globally inconsistent maps, we introduce a systematic approach to incorporating sparse human corrections, which we term Human-in-the-Loop Simultaneous Localization and Mapping (HitL-SLAM). Given an initial factor graph for pose graph SLAM, HitL-SLAM accepts approximate, potentially erroneous, and rank-deficient human input, infers the intended correction via expectation maximization (EM), back-propagates the extracted corrections over the pose graph, and finally jointly optimizes the factor graph including the human inputs as human correction factor terms, to yield globally consistent large-scale maps. We thus contribute an EM formulation for inferring potentially rank-deficient human corrections to mapping, and human correction factor extensions to the factor graphs for pose graph SLAM that result in a principled approach to joint optimization of the pose graph while simultaneously accounting for multiple forms of human correction. We present empirical results showing the effectiveness of HitL-SLAM at generating globally accurate and consistent maps even when given poor initial estimates of the map.Comment: AAAI 201

Effect of realistic interatomic interactions and two-body correlation on the heat capacity of a trapped BEC

An approximate many-body theory has been used to calculate the heat capacity and the condensate fraction of a BEC with effective repulsive interaction. The effect of interactions has been analyzed and compared with the non-interacting case. It has been found that the repulsive interaction lowers the critical temperature from the value found in the non-interacting case. The difference between the critical temperatures increases with the increase in the total number of atoms in the trap.Comment: 15 pages, 5 figure

On-farm impact analysis of resource conservation technology on wheat at Tarai-Teesta Flood plain of Eastern Indo-Gangetic Plain (IGP)

Adoption of resource conservation technologies (RCT) may improve the productivity, reduce cost and sustainability of wheat production in the irrigated areas of eastern Indo-Gangetic plains (IGP) of South Asia. Critical on –farm study on factors favouring adoption and non-adoption is required. Findings from an on-farm trial conducted during 2005-2009 are used to evaluate the on-farm impacts of zero tillage (ZT) in wheat from three sites at Tarai-Teesta flood plain of eastern IGP. On an average, there was 11.54% increase in productivity in ZT wheat over conventional tilled (CT) wheat. Water productivity increased from 1.99 kg m-3 in CT to 2.73 kg m-3 in ZT due to lower estimated water use (1147 m3 ha-1 in ZT than 1435 m3 ha-1 in CT) and higher productivity (3.38 t ha-1 in ZT than 3.03 t ha-1 in CT). Saving in tractor operation and diesel use in farmers’ ZT wheat fields were 3.23 and 19.09 hours ha-1. Sowing can be done earlier by one week through adoption of ZT machine for better utilization of limited winter. Savings in ZT on farmers’ fields were in the components of land preparation (1938 Rs ha-1), seed (462 Rs ha-1), nitrogen (269 Rs ha-1), phosphate fertilizer (104 Rs ha-1) and irrigation (380 Rs ha-1) over conventional wheat cultivation. Availability of zero-till seeder and its servicing, skilled operator and sometimes reluctance of local tiller operator for apprehension of lower earnings from single tillage pass are also revealed as the factors of non-adoption. More such in-depth studies should be conducted on site-specific basis so that it can be replicated more widely in areas for the benefit of the farming community

Evidence for the existence of a novel enzyme system. myo-inositol-1-phosphate dehydrogenase in Phaseolus aureus

A novel enzyme system, myo-inositol-1-phosphate dehydrogenase, has been isolated from germinating mung bean seeds. The dehydrogenation and cleavage of myo-inositol 1-phosphate by this enzyme leads to the synthesis of a pentose phosphate which appears to be ribulose 5-phosphate. The pH optimum of the enzyme is 8.6; NAD+ is required as coenzyme and no other nucleotides can replace NAD+. Mono- or divalent cations are not essential for the enzyme activity. Stoichiometry of the reaction suggests that 2 mol of NAD+ are reduced per mol of ribulose-5-P generated

RNA synthesis in maturing avian erythrocyte nuclei

The rate of RNA synthesis and its inhibition by α-amanitin in the nuclei of mature and immature avian erythrocytes are increased with the increase in ionic strength of incubation medium. Polyacrylamide gel electrophoresis indicates that heterogeneous species of RNAs are synthesised in the mature and immature erythrocyte nuclei. However, a large number of high molecular weight RNAs are synthesised in the nuclei of immature erythrocytes. Elution profiles on poly(U)-sepharose chromatography indicate that the RNAs synthesised in the nuclei of two types of cell contain poly(A) segments. Sixteen per cent of mature erythrocyte nuclear RNA syntbesised are polyadenylated, while it is 13% in immature erythrocyte nuclei. However, the total RNA synthesised is 2-3 fold higher in immature erythrocyte nuclei than that in mature erythrocyte nuclei

Role of B-ring of colchicine in its binding to tubulin

The chemical specificity of the colchicine-binding site of tubulin is less stringent for the presence of the B-ring than the A- and C-rings of colchicine, Colchicine analogues with modifications in the B-ring bind to tubulin at the same site as colchicine. Analogues with smaller or no substituents in the B-ring bind tubulin remarkably faster than colchicine. Thus, a compound without the B-ring [2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone] binds tubulin even at 4 °C and the binding is almost instantaneous at 37 °C. Colcemid and 2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone bind reversibly to tubulin, whereas colchicine and desacetamidocolchicine bind almost irreversibly, suggesting that the size of the B-ring moiety of colchicine is not related to the reversibility of binding. We conclude that although the presence of the B-ring of colchicine does not appear to be an essential prerequisite for the drug-tubulin interaction, the B-ring substituents play an important role in determining the binding properties of colchicine to tubulin