Reuleaux: Robot Base Placement by Reachability Analysis

Before beginning any robot task, users must position the robot's base, a task that now depends entirely on user intuition. While slight perturbation is tolerable for robots with moveable bases, correcting the problem is imperative for fixed-base robots if some essential task sections are out of reach. For mobile manipulation robots, it is necessary to decide on a specific base position before beginning manipulation tasks. This paper presents Reuleaux, an open source library for robot reachability analyses and base placement. It reduces the amount of extra repositioning and removes the manual work of identifying potential base locations. Based on the reachability map, base placement locations of a whole robot or only the arm can be efficiently determined. This can be applied to both statically mounted robots, where position of the robot and work piece ensure the maximum amount of work performed, and to mobile robots, where the maximum amount of workable area can be reached. Solutions are not limited only to vertically constrained placement, since complicated robotics tasks require the base to be placed at unique poses based on task demand. All Reuleaux library methods were tested on different robots of different specifications and evaluated for tasks in simulation and real world environment. Evaluation results indicate that Reuleaux had significantly improved performance than prior existing methods in terms of time-efficiency and range of applicability.Comment: Submitted to International Conference of Robotic Computing 201

Toward an Alternative Intrinsic Probe for Spectroscopic Characterization of a Protein

The intrinsic fluorescent amino acid tryptophan is the unanimous choice for the spectroscopic investigation of proteins. However, several complicacies in the interpretation of tryptophan fluorescence in a protein are inevitable and an alternative intrinsic protein probe is a longstanding demand. In this contribution, we report an electron-transfer reaction in a human transporter protein (HSA) cavity which causes the tryptophan residue (Trp214) to undergo chemical modification to form one of its metabolites kynurenine (Kyn214). Structural integrity upon modification of the native protein is confirmed by dynamic light scattering (DLS) as well as near and far circular dichroism (CD) spectroscopy. Femtosecond-resolved fluorescence transients of the modified protein describe the dynamics of solvent molecules in the protein cavity in both the native and denatured states. In order to establish general use of the probe, we have studied the dipolar interaction of Kyn214 with a surface-bound ligand (crystal violet, CV) of the protein. By using the sensitivity of FRET, we have determined the distance between Kyn214 (donor) and CV (acceptor). Our study is an attempt to explore an alternative intrinsic fluorescence probe for the spectroscopic investigation of a protein. In order to establish the efficacy of the modification technique we have converted the tryptophan residues of other proteins (bovine serum albumin, chymotrypsin and subtilisin Carlsberg) to kynurenine and confirmed their structural integrity. We have also shown that catalytic activity of the enzymes remains intact upon the modification

Grasping unknown objects in clutter by superquadric representation

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this paper, a quick and efficient method is presented for grasping unknown objects in clutter. The grasping method relies on real-time superquadric (SQ) representation of partial view objects and incomplete object modelling, well suited for unknown symmetric objects in cluttered scenarios which is followed by optimized antipodal grasping. The incomplete object models are processed through a mirroring algorithm that assumes symmetry to first create an approximate complete model and then fit for SQ representation. The grasping algorithm is designed for maximum force balance and stability, taking advantage of the quick retrieval of dimension and surface curvature information from the SQ parameters. The pose of the SQs with respect to the direction of gravity is calculated and used together with the parameters of the SQs and specification of the gripper, to select the best direction of approach and contact points. The SQ fitting method has been tested on custom datasets containing objects in isolation as well as in clutter. The grasping algorithm is evaluated on a PR2 robot and real time results are presented. Initial results indicate that though the method is based on simplistic shape information, it outperforms other learning based grasping algorithms that also work in clutter in terms of time-efficiency and accuracy.Peer ReviewedPostprint (author's final draft

Interaction of an Antituberculosis Drug with a Nanoscopic Macromolecular Assembly: Temperature-Dependent Förster Resonance Energy Transfer Studies on Rifampicin in an Anionic Sodium Dodecyl Sulfate Micelle

In this contribution, we report studies on the nature of binding of a potent antituberculosis drug, Rifampicin (RF) with a model drug delivery system, sodium dodecyl sulfate (SDS) micelle. Temperature dependent dynamic light scattering (DLS), conductometry, and circular dichroism (CD) spectroscopy have been employed to study the binding interaction of the drug with the micelle. The absorption spectrum of the drug RF in the visible region has been employed to study Förster resonance energy transfer (FRET) from another fluorescent drug Hoechst 33258 (H33258), bound to the micelle. Picosecond-resolved FRET studies at room temperature confirm the simultaneous binding of the two drugs to the micelle and the distance between the donor−acceptor pair is found to be 34 Å. The temperature dependent FRET study also confirms that the location and efficiency of drug binding to the micelle changes significantly at the elevated temperature. The energy transfer efficiency of the donor H33258, as measured from time-resolved studies, decreases significantly from 76% at 20 °C to 60% at 55 °C. This reveals detachment of some amount of the drug molecules from the micelles and increased donor−acceptor distance at elevated temperatures. The estimated donor−acceptor distance increases from a value of 33 Å at 20 °C to 37 Å at 55 °C. The picosecond resolved FRET studies on a synthesized DNA bound H33258 in RF solution have been performed to explore the interaction between the two. Our studies are expected to find relevance in the exploration of a potential vehicle for the vital drug rifampicin

Photoselective excited state dynamics in ZnO–Au nanocomposites and their implications in photocatalysis and dye-sensitized solar cells

Improving the performance of photoactive solid-state devices begins with systematic studies of the metal–semiconductor nanocomposites (NCs) upon which such devices are based. Here, we report the photo-dependent excitonic mechanism and the charge migration kinetics in a colloidal ZnO–Au NC system. By using a picosecond-resolved Förster resonance energy transfer (FRET) technique, we have demonstrated that excited ZnO nanoparticles (NPs) resonantly transfer visible optical radiation to the Au NPs, and the quenching of defect-mediated visible emission depends solely on the excitation level of the semiconductor. The role of the gold layer in promoting photolytic charge transfer, the activity of which is dependent upon the degree of excitation, was probed using methylene blue (MB) reduction at the semiconductor interface. Incident photon-to-current efficiency measurements show improved charge injection from a sensitizing dye to a semiconductor electrode in the presence of gold in the visible region. Furthermore, the short-circuit current density and the energy conversion efficiency of the ZnO–Au NP based dye-sensitized solar cell (DSSC) are much higher than those of a DSSC comprised of only ZnO NP. Our results represent a new paradigm for understanding the mechanism of defect-state passivation and photolytic activity of the metal component in metal–semiconductor nanocomposite systems

SOME RESULTS ON GENERALIZED (k,μ)(k,\mu)-PARACONTACT METRIC MANIFOLDS

The object of this paper is to study Codazzi type of Ricci tensor in generalized $(k,\mu )$-paracontact metric manifolds. Next we study cyclic parallel Ricci tensor in generalized $(k,\mu )$-paracontact metric manifolds. Further, we characterized generalized $(k,\mu )$-paracontact metric manifolds whose structure tensor $\phi$ is $\eta$-parallel. Finally, we investigate locally $\phi$-Ricci symmetric generalized $(k,\mu )$-paracontact metric manifolds

An exploration of appearance-driven fruit and vegetable waste through the eyes of children: A consumer socialisation perspective

“We need to find the beauty inside these vegetables, and not only on the outside.” ―Dana Cowin, Food & Wine Editor-In-Chief Food waste is a global issue with negative social, economic, and environmental consequences. Of all the food categories, fruits and vegetables comprise the largest share of global foodstuffs waste. A major cause of this waste is consumers’ unwillingness to purchase and consume produce that look atypical, or suboptimal. In this thesis, fresh fruits and vegetables that deviate in appearance from what is considered normal, are called ‘suboptimal’. The suboptimal foods literature has tended to focus on adult consumers’ perceptions and behaviours towards suboptimal produce, with a dearth of research that has explored this context from the young consumer’s perspective. Understanding these behaviours from the perspectives of children, is not just a novel perspective for understanding consumer behaviour towards suboptimal produce waste, but also provides an opportunity to understand how these perceptions are socialised. The young consumer segment comprises of children characterised by their concerns for global sustainability issues and willingness to participate in consumer activism to voice their concerns for environmental degradation; hence their voices are increasingly being heard and taken into consideration by both industry and policy makers. The overall objective of this thesis is to explore suboptimal produce consumption, purchase, and preference from the perspectives of children, thereby also casting light on how these preferences are socialised. To do so, a two-step methodological approach involving a mock shopping activity and focus group discussions with 97 children aged between 5 and 11 was undertaken. The first step was a shopping activity which was used to directly observe how fruit and vegetable choices are made. This was followed by focus group discussions which asked children about their preference between a suboptimal and optimal fruit or vegetable; their previous exposure to atypical fruit and vegetables; and their knowledge and awareness about suboptimal produce waste and waste reduction initiatives. Thereafter an inductive thematic analysis was used to analyse the data and derive themes which have been reported across the three papers which form the results section of this thesis. In line with the global target to halve per capita food waste by 2030 (Target 12.3 of the 12th Sustainable Development Goal), retailers worldwide have initiated selling suboptimal produce in supermarkets. The retailing strategy to market suboptimal produce includes using imagery that may appeal to children, however there is a dearth of research that has studied how children perceive suboptimal produce. Hence, the first paper (chapter 3) explored how children perceive the edibility of suboptimal fruits and vegetables with respect to different types of appearance defects, namely shape, size and colour defects, and blemish levels. This study found that children are largely accepting of suboptimal produce. Specifically, defects in shape, size, and certain colour defects were positively perceived, whilst blemishes and brown discolorations were negatively perceived. Overall, in comparison to the past literature on how (adult) consumers perceive suboptimal produce, children were more accepting of most appearance defects. Hence, the findings of this study have implications for retailers selling suboptimal produce, who could potentially market suboptimal produce to children as they are accepting of most types of appearance-defects in fruits and vegetables. Academically, this paper revealed the nuances of consumer edibility perceptions with respect to different types of appearance defects. Furthermore, the findings revealed that children’s edibility perceptions were linked to familiarity, a product of one’s food socialisations, which informed the objective of the second study which was to explore how appearance-preferences for fresh fruits and vegetables are socialised. Although research suggests the possibility of consumers’ rejection of suboptimal produce being socialised, empirical research that has explored these socialisations is lacking. Understanding these socialisations provides useful insight into how suboptimal produce purchase, consumption, and use could be normalised. Hence, the second paper (chapter 4) explored the underlying socialisations that lead to either the acceptance or rejection of suboptimal produce. Four factors were identified as socialising factors that lead to the acceptance of suboptimal produce. These include growing fruits and vegetables at home, repurposing suboptimal produce, learning about food waste, and produce choice autonomy. These factors familiarise and normalise seeing, using, and consuming suboptimal produce. These socialisations also empower children to challenge the existing appearance-based prejudices against suboptimal produce, and likewise make volitional choices favouring suboptimal produce over the regular optimal produce. Alternatively, the factors that contribute to the rejection of suboptimal produce are driven by children’s observations of parents’ produce choice behaviours in-store, and parental/family norms about how fruits and vegetables should be chosen, prepared, and consumed. These observations and subsequent practice of family norms convey desirable produce appearance preferences, which are learnt and replicated. Overall, this study provides implications for public policy that is working towards normalising suboptimal produce. It provides a novel perspective to suboptimal produce preference or rejection by exploring the phenomenon through the consumer socialisation lens. The third paper (chapter 5), presents suggestions for retailers to consider in light of preventing suboptimal produce devaluation and waste through children’s own voices. The findings highlight that the current marketing strategies retailers employ for selling suboptimal produce differentiates and devalues produce on the basis of appearance. Hence alternative strategies, such as relaxing appearance standards and allowing shelf space for produce with extreme appearance deformities, and using non-discriminatory branding, product placement, messaging and pricing strategies were suggested. Additionally, strategies to prevent suboptimal produce waste were suggested. These include targeted marketing of suboptimal produce to children and redistributing suboptimal produce to children through the existing ‘Free Fruit for Kids’ channel; encouraging suboptimal produce choice in-store by using facts to spread awareness about suboptimal produce waste and gamifying the purchase and consumption of suboptimal produce; and donating unsold suboptimal produce to poor local communities. These recommendations not only show how suboptimal produce devaluation and waste could be minimised, but also opens new frontiers for suboptimal produce retailing strategies. In sum, this thesis makes a number of academic and applied contributions. It is the first body of work that has explored consumer behaviour towards suboptimal produce from a young consumer’s perspective. It is also the first to have examined and compared children’s perceptions about all the major appearance defects in fresh produce to report how these perceptions differ across varying appearance defects. As a result, the implications of this research are more specific to different types of appearance defects. It has applied the consumer socialisation theory to identify the socialisations that form these perceptions towards suboptimal produce, thereby advancing the suboptimal produce waste literature by understanding consumer perceptions through a sociological lens. Alternatively, it has contributed to the consumer socialisation literature by showing how various food-related social practices (e.g., growing produce, repurposing suboptimal produce, grocery shopping etc.) influence consumer perception and valuation of suboptimal produce. In practice, the findings from the three papers largely inform retailing practices for marketing and selling suboptimal produce. The research also influences how policy makers could implement normalisation strategies for increasing the acceptance of suboptimal produce. These suggestions are useful for organisations working with the United Nations to meet their food waste reduction targets and goals, thereby enhancing the value of food whilst also achieving greater food sustainability in the long-run

COUGH AND CHEST PAIN WITH AN UNCOMMON CAUSE

Multiple  Hereditary  Exostoses  is  an  autosomal  dominant  disorder  with  multiple  cartilage  capped  bony  outgrowths  in  tibia  ,fibula, femur,  and  sometimes  the  ribs  and  scapula. They may  present  with  variety  of  symptoms  depending  on  the  structures  it  compresses  such  as  nerves,  arteries  or  may  lead  to  limb  deformities  or  may  cause  bursitis , or  may  undergo  malignant  transformation. A  33 year old  male  presented  to  our  outpatient  department  with  recurrent  cough  and  left  sided  chest  pain. On  evaluation  he  was  found  to  have  multiple  bony  outgrowths  in the scapula ,5th  rib , and  limbs. Similar  bony  outgrowths  were  also  present  in  his  father  and  grandfather. On  clinical  and  radiological  basis  a  diagnosis of  Multiple  Hereditary  Exostoses  was  made. His  symptoms  gradually  subsided  with  removal  of  the  rib  and  scapular  exostoses. Thus  evaluation  of  bony  structures  should  not  be  overlooked  in  cases  of  cough  and  chest  pain.Keywords: Cough, Chestpain, Multiple  Hereditary  Exostoses.Â