Affordance-based robot object retrieval

Autonomous Robots - Natural language object retrieval is a highly useful yet challenging task for robots in human-centric environments. Previous work has primarily focused on commands specifying...     

Quantum approaches to graph colouring

In this paper, we investigate quantum algorithms for graph colouring problems, in particular for 2- and 3-colouring of graphs. Our main goal is to establish a set of quantum representations and operations suitable for the problem at hand. We propose unitary- as well as measurement-based quantum computations, also taking inspiration from answer set programming, a form of declarative programming close to traditional logic programming. The approach used is one in which we first generate arbitrary solutions to the problem, then constraining these according to the problem’s input. Though we do not achieve fundamental speed-ups, our algorithms show how quantum concepts can be used for programming and moreover exhibit structural differences. For example, we compute all possible colourings at the same time. We compare our algorithms with classical ones, highlighting how the same type of difficulties give rise to NP-complete behaviour, and propose possible improvements.     

Removal of dissolved rhenium by sorption onto organic polymers: study of rhenium as an analogue of radioactive technetium

Technetium (99Tc) is one of the main components of nuclear wastes. Tc characteristics can be predicted by studying rhenium (75Re), one of its chemical analogue, thus avoiding the use of a radioactive element at high concentrations. The objectives of this experimental study was to understand the sorption behavior of Re with natural organic materials in order to define the possible condition of Tc uptake in case where Tc may be transferred into surface or ground waters. As the well-defined organic sorbents we chose chitosan which contains amine -NH2 groups; poly-galacturonic acid (PGA) and poly-styrene sulfonates (PSS) which contain respectively carboxyl -COOH and sulfonate -SO3H groups. Concerning the reaction of Re with PGA or with PSS, no interaction between Re and carboxyl or sulfonate groups was found within the detection limit of this study. Re sorption on chitosan was found to be dependent on ionic strength and pH. We propose that non-specific sorption of perrhenate ion ReO4- via electrostatic interaction takes place at the protonated amine groups NH3+. The polymer-solution interface can be described by the electric diffuse double layer model combined with the Langmuir-Freundlich model. The calculation is in good agreement with our experimental results.     

Processing of observed pupil size modulates perception of sadness and predicts empathy.

Facial autonomic responses may contribute to emotional communication and reveal individual affective style. In this study, the authors examined how observed pupillary size modulates processing of facial expression, extending the finding that incidentally perceived pupils influence ratings of sadness but not those of happy, angry, or neutral facial expressions. Healthy subjects rated the valence and arousal of photographs depicting facial muscular expressions of sadness, surprise, fear, and disgust. Pupil sizes within the stimuli were experimentally manipulated. Subjects themselves were scored with an empathy questionnaire. Diminishing pupil size linearly enhanced intensity and valence judgments of sad expressions (but not fear, surprise, or disgust). At debriefing, subjects were unaware of differences in pupil size across stimuli. These observations complement an earlier study showing that pupil size directly influences processing of sadness but not other basic emotional facial expressions. Furthermore, across subjects, the degree to which pupil size influenced sadness processing correlated with individual differences in empathy score. Together, these data demonstrate a central role of sadness processing in empathetic emotion and highlight the salience of implicit autonomic signals in affective communication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Internal working models, self-reported problems, and help-seeking attitudes among college students.

A person's internal working models of close relationships (J. Bowlby, 1988) incorporate 2 discrete yet interrelated cognitive schemas: a self model containing perceptions of one's own worth and lovability and an other model embodying core expectations about the trustworthiness and dependability of intimate others in one's social world. This study tested hypothesized interrelationships, in a college-student sample, (a) between self-model differences and self-reported problems and (b) among other-model differences, problem levels, and help-seeking attitudes. As expected, students with positive self models reported significantly fewer problems than did students with negative self models. In addition, students' other-model grouping significantly interacted with their problem levels to predict their expressed willingess to seek counseling. Implications of the findings for counseling practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gyroid‐Structured 3D ZnO Networks Made by Atomic Layer Deposition

3D continuous ZnO morphologies with characteristic feature sizes on the 10 nm length scale are attractive for electronic device manufacture. However, their synthesis remains a challenge because of the low crystallization temperature of ZnO. Here, we report a method for the robust and reliable synthesis of fully crystalline 3D mesoporous ZnO networks by means of atomic layer deposition (ALD) of ZnO into a self‐assembled block copolymer template. By carefully optimizing the processing conditions we are able to synthesize several‐micrometer‐thick layers of mesoporous ZnO networks with a strut width of 30 nm. Two 3D mesoporous morphologies are manufactured: a periodic gyroid structure and a random worm‐like morphology. Exploiting the ALD property to conformally coat complex surfaces of high aspect ratio, the channel network of a 3D continuous channel network of a self‐assembled block copolymer is replicated into ZnO. X‐ray photoemission spectroscopy and x‐ray diffraction measurements reveal that the chemical composition of the mesoporous structures is uniform and consists of wurtzite‐ZnO throughout the film. Scanning electron microscopy reveals an average pore dimension of 30 nm. The potential of this material for a hybrid photovoltaic application is demonstrated by the manufacture of a poly(3‐hexylthiophene)/ZnO solar cell.     

Status of behavioral reorientation techniques in the modification of homosexuality: A review.

The use of behavioral techniques to modify various characteristics of sexual preference has increased substantially since 1960. Since 1960, 13 group studies and 24 case studies designed to alter one or more characteristics of sexual preference have been conducted. A number of different procedures have been employed to alter sexual preference, heterosocial skills, and gender identity. The present article attempts to summarize the critical components of the reorientation programs, examine the outcomes of the programs, and discuss possible shortcomings of the procedures currently used. Results of the review indicate that (a) very few females request sexual reorientation treatment (only 4 female homosexuals were included in the sexual orientation literature); (b) the controlled studies yield more conservative data than do the uncontrolled studies (of the studies noted above, only 54% of the group studies and 46% of the case studies included some control variables); and (c) the use of multiple-target treatment procedures greatly enhances the effectiveness of the procedures. (50 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Digital access,choice and agency in remote Sarawak

Internet use and access to digital devices continues to increase even in remote regions around the world, but users do not participate equally or engage in the same practices online. This leads to inequalities in the outcomes different groups of users can generate as a result of their online practices. Drawing from recent literature on digital divides and using a theoretical framework focused on user choice and agency, we present data from a study of internet and device use in remote villages in Sarawak, a state of Malaysia on the island of Borneo. These villages lack most basic infrastructure such as paved roads or grid electricity, but some have mobile phone and mobile internet access installed under Malaysia’s Universal Service Provision. We discuss qualitative and quantitative data collected between 2015 and 2017 to point to the opportunities as well as obstacles users in remote communities encounter in their engagements with digital devices and the internet. We argue that while remote areas seem to lag behind urban areas in terms of users’ internet skills and practices, people choose to engage with these technologies in ways that are appropriate to their needs and to the local low-bandwidth environment. To enable these communities to tap into additional potential benefits of internet use, however, faster and more reliable access is a prerequisite.     

Measurement of protein-like fluorescence in river and waste water using a handheld spectrophotometer

Protein-like fluorescence intensity in rivers increases with increasing anthropogenic DOM inputs from sewerage and farm wastes. Here, a portable luminescence spectrophotometer was used to investigate if this technology could be used to provide both field scientists with a rapid pollution monitoring tool and process control engineers with a portable waste water monitoring device, through the measurement of river and waste water tryptophan-like fluorescence from a range of rivers in NE England and from effluents from within two waste water treatment plants. The portable spectrophotometer determined that waste waters and sewerage effluents had the highest tryptophan-like fluorescence intensity, urban streams had an intermediate tryptophan-like fluorescence intensity, and the upstream river samples of good water quality the lowest tryptophan-like fluorescence intensity. Replicate samples demonstrated that fluorescence intensity is reproducible to +/- 20% for low fluorescence, 'clean' river water samples and +/- 5% for urban water and waste waters. Correlations between fluorescence measured by the portable spectrophotometer with a conventional bench machine were 0.91; (Spearman's rho, n = 143), demonstrating that the portable spectrophotometer does correlate with tryptophan-like fluorescence intensity measured using the bench spectrophotometer.     

Charge Separation in BaTiO3 Nanocrystals: Spontaneous Polarization Versus Point Defect Chemistry

The fate of photogenerated charges within ferroelectric metal oxides is key for photocatalytic applications. The authors study the contributions of i) tetragonal distortion, responsible for spontaneous polarization, and ii) point defects, on charge separation and recombination within BaTiO₃ (BTO) nanocrystals of cubic and tetragonal structure. Electron paramagnetic resonance (EPR) in combination with O₂ photoadsorption experiments show that BTO nanocrystals annealed at 600 °C have a charge separation yield enhanced by a factor > 10 compared to TiO₂ anatase nanocrystals of similar geometries. This demonstrates for the first time the beneficial effect of the BTO perovskite nanocrystal lattice on charge separation. Strikingly, charge separation is considerably hindered within BTO nanoparticles annealed ≥ 600 °C, due to the formation of Ba–O divacancies that act as charge recombination centers. The opposing interplay between tetragonal distortion and annealing-induced defect formation inside the lattice highlights the importance of defect engineering within perovskite nanoparticles.