Seebeck Nanoantennas for Infrared Detection and Energy Harvesting Applications

In this letter we introduce a new type of infrared sensor, based on thermocouple nanoantennas, which enables the energy detection and gathering in the mid-infrared region. The proposed detector combines the Seebeck effect, as a transduction mechanism, with the functionalities of the optical antennas for optical sensing. By using finite-element numerical simulations we evaluate the performance and optical-to-electrical conversion efficiency of the proposed device, unveiling its potential for optical sensing and energy harvesting applications.Comment: 4 pages, 3 figures, Invited paper at EUCAP 201

Dynamic expression of VDR and 1-­alpha-­hydroxylase in differentiated and re-­differentiated human articular chondrocytes

Abstract of a presentation at a conference of the International Cartilage Repair Society.Purpose: The goal was to investigate potential roles played by vitamin D in the regulation of joint cartilage biology. We studied the expression of two central elements of vitamin D metabolism, namely the vitamin D receptor and its converting enzyme 1­α­hydroxylase in human knee cartilage and chondrocytes. Methods and Materials: Expression of receptor and enzyme was determined by immunohistochemistry/immunofluorescence, reversetranscriptase PCR and western blot on differentiated, de­differentiated and re­differentiated chondrocytes. Cartilage was harvested from a macroscopically healthy looking area of the lateral femoral condyle during knee replacement surgery in 4 otherwise healthy patients aged 50­70. Suspension cultures of differentiated chondrocytes were established by short enzymatic digestion of cartilage using Collagenase XI and further incubation in non­adherent vessels. De­differentiated cells were the result of serial expansion of chondrocytes during 4 weeks after isolation in monolayers cultures. Chondrocyte re­differentiation was achieved by propagating cell pellets for 3 weeks in the presence of chondro­inductive morphogens. Results: Both protein and gene expression of vitamin D receptor appear to be very low or undetectable in native cartilage and/or differentiated chondrocytes. In contrast, receptor expression was upregulated in dedifferentiated cells after monolayer expansion, however, this upregulation was lost when cells regained chondrogenic phenotype in 3D pellets. The expression of 1­α­hydroxylase was observed on the superficial layer of chondrocytes in native cartilage, which correlated with weak but detectable outcomes by PCR and western blot on differentiated cultures. Similarly, levels of the enzyme were increased after cell expansion in monolayers and decreased in 3D pellet cultures. Conclusion: Our study uncover a previously unknown regulation of vitamin D receptor between differentiated and redifferentiated phenotypes in cartilage cells. Furthermore, this study is pioneering on investigating the expression of 1­α­hydroxylase in cartilage tissue and chondrocytes. Further work is needed to ascertain if receptor and enzyme expression is regulated in disease conditions or affected by inflammatory environments

Microarray tools to unveil viral-microbe interactions in nature

The interactions between viruses and their microbial hosts play a central role in the control of microbial communities in nature. However, the study of such interactions within the uncultured majority is technically very challenging. Here, we review how microarray tools can be used to analyze the interactions between viruses and their microbial hosts in nature, away from laboratory pure culture-based models. We show examples of how DNA arrays have been used to study the expression of viral assemblages in natural samples, and to assign viruses to hosts within uncultured communities. Finally, we briefly discuss the possibilities of protein and glycan arrays to gain insight into the ways microbes interact with their viruses.Our current studies with viral microarrays are supported by projects CGL2012-39627-C03-01 (to Josefa Antón) and AYA2011-24803 (to Víctor Parro) of the Spanish Ministry of Science and Innovation, which are co-financed with FEDER support from the European Union

Mistrust and negative self‐esteem:Two paths from attachment styles to paranoia

OBJECTIVES: Paranoia is known to be associated with insecure attachment, with negative self‐esteem as a mediator, but this pathway is insufficient to explain the paranoid individual’s beliefs about malevolent others. Mistrust is a likely additional factor as it is a core feature of paranoid thinking also associated with insecure attachment styles. In this study, we tested whether mistrust – operationalized as judgements about the trustworthiness of unfamiliar faces – constitutes a second pathway from insecure attachment to paranoia. DESIGN: The design of the study was cross‐sectional. METHODS: A nationally representative British sample of 1,508 participants aged 18–86, 50.8% female, recruited through the survey company Qualtrics, completed measurements of attachment style, negative self‐esteem, and paranoid beliefs. Usable data were obtained from 1,121 participants. Participants were asked to make trustworthiness judgements about computer‐generated faces, and their outcomes were analysed by conducting signal detection analysis, which provided measures of bias (the tendency to assume untrustworthiness in conditions of uncertainty) and sensitivity (accuracy in distinguish between trustworthy and untrustworthy faces). RESULTS: Results using structural equation modelling revealed a good model fit (RMSEA = .071, 95% CI: 0.067–0.075, SRMR = .045, CFI = .93, TLI = .92). We observed indirect effects through bias towards mistrust both for the relationship between attachment anxiety and avoidance (β = .003, 95% CI: 0.001–0.005,p < .001) and attachment anxiety and paranoia (β = .003, 95% CI 0.002–0.006, p < .001). We observed an indirect effect through negative self‐esteem only for the relationship between attachment anxiety and paranoia (β = .064, 95% CI: 0.053–0.077, p < .001). Trust judgements and negative self‐esteem were not associated with each other. CONCLUSIONS: We find that a bias towards mistrust is associated with greater paranoia. We also find indirect effects through bias towards mistrust between attachment styles and paranoia. Finally, we reaffirm the strong indirect effect through negative self‐esteem between attachment anxiety and paranoia. Limitations of the study are discussed. PRACTITIONER POINTS: When working with individuals suffering from paranoia, clinicians should consider not only explicit, deliberative cognitive processes of the kind addressed in cognitive behaviour therapy (e.g. cognitive restructuring) but also the way in which their patients make perceptual judgements (e.g., their immediate reactions on encountering new people) and consider interventions targeted at these judgements, for example, bias modification training. Assessment and clinical interventions for people should consider the role of trust judgements and the way in which they combine with low self‐esteem to provoke paranoid beliefs. Psychological interventions targeting paranoid beliefs should focus on both attachment anxiety and attachment avoidance

Paranoid beliefs and conspiracy mentality are associated with different forms of mistrust: A three-nation study

Paranoia and conspiracy are terms typically used interchangeably. However, although the underlying content of these types of beliefs might be similar (e.g., seeing others as powerful and threatening), recent research suggests that these constructs differ in important ways. One important feature shared by both constructs is excessive mistrust but this aspect might play different roles in each belief system. In this study we explored the strength of associations of different trust predictors (i.e., trust in institutions, trust in sources of information, perceptual trust, and interpersonal trust) between conspiracy mentality and paranoid beliefs. We tested this association in a large representative multinational sample (United Kingdom n = 2025; Spain n = 1951; and Ireland n = 1041). Confirmatory factor analysis supported a two-factor model of conspiracy and paranoid beliefs in each nation sample. Path and equality of constraints analysis revealed that paranoia was more strongly associated with perceptual mistrust (bias towards mistrusting unfamiliar faces) whereas conspiracy was more strongly associated with mistrust in political institutions. Although interpersonal mistrust and trust in social sources of information were associated significantly with conspiracy their association with paranoid beliefs was stronger. These findings clarify the role of different trust processes in both belief systems. Limitations of this study are discussed

Retinal-binding proteins mirror prokaryotic dynamics in multipond solar salterns

Microbial opsin (i.e. retinal-binding protein) dynamics has been studied along a salinity gradient in Santa Pola solar salterns (Alicante, Spain) by using culture-independent approaches and statistical analyses. Five ponds of salinities ranging from 18% to above 40% were sampled nine times along a year. Forty-three opsin-like sequences were retrieved by denaturing gradient gel electrophoresis and clustered into 18 different phylogroups, indicating that their diversity was higher than expected according to previous data. Moreover, the statistical correlation between environmental factors controlling microbial community structure and dynamics of environmental rhodopsin proteins indicated almost identical temporal fluctuations between the opsin-related sequences and their corresponding putative ‘producers’ in nature. Although most sequences were related to others previously detected in hypersaline environments, some pond-specific opsins putatively belonged to previously uncharacterized hosts. Furthermore, we propose that subtle changes in the bacteriorhodopsin ‘retinal proton binding pocket’, which is key in the photocycle function, could be the molecular basis behind a fine ‘photocycle-tuning’ mechanism to avoid inter/intraspecies light-competition in hypersaline environments.This work was supported by project CGL2012-39627-C03-01 of the Spanish Ministry of Economy and Competitiveness, which was also co-funded with FEDER support from the European Union

Multiphasic on/off pheromone signalling in moths as neural correlates of a search strategy

Insects and robots searching for odour sources in turbulent plumes face the same problem: the random nature of mixing causes fluctuations and intermittency in perception. Pheromone-tracking male moths appear to deal with discontinuous flows of information by surging upwind, upon sensing a pheromone patch, and casting crosswind, upon losing the plume. Using a combination of neurophysiological recordings, computational modelling and experiments with a cyborg, we propose a neuronal mechanism that promotes a behavioural switch between surge and casting. We show how multiphasic On/Off pheromone-sensitive neurons may guide action selection based on signalling presence or loss of the pheromone. A Hodgkin-Huxley-type neuron model with a small-conductance calcium-activated potassium (SK) channel reproduces physiological On/Off responses. Using this model as a command neuron and the antennae of tethered moths as pheromone sensors, we demonstrate the efficiency of multiphasic patterning in driving a robotic searcher toward the source. Taken together, our results suggest that multiphasic On/Off responses may mediate olfactory navigation and that SK channels may account for these responses

Interactions between Closely Related Bacterial Strains Are Revealed by Deep Transcriptome Sequencing

Comparative genomics, metagenomics, and single-cell technologies have shown that populations of microbial species encompass assemblages of closely related strains. This raises the question of whether individual bacterial lineages respond to the presence of their close relatives by modifying their gene expression or, instead, whether assemblages simply act as the arithmetic addition of their individual components. Here, we took advantage of transcriptome sequencing to address this question. For this, we analyzed the transcriptomes of two closely related strains of the extremely halophilic bacterium Salinibacter ruber grown axenically and in coculture. These organisms dominate bacterial assemblages in hypersaline environments worldwide. The strains used here cooccurred in the natural environment and are 100% identical in their 16S rRNA genes, and each strain harbors an accessory genome representing 10% of its complete genome. Overall, transcriptomic patterns from pure cultures were very similar for both strains. Expression was detected along practically the whole genome albeit with some genes at low levels. A subset of genes was very highly expressed in both strains, including genes coding for the light-driven proton pump xanthorhodopsin, genes involved in the stress response, and genes coding for transcriptional regulators. Expression differences between pure cultures affected mainly genes involved in environmental sensing. When the strains were grown in coculture, there was a modest but significant change in their individual transcription patterns compared to those in pure culture. Each strain sensed the presence of the other and responded in a specific manner, which points to fine intraspecific transcriptomic modulation.The group of J.A. is funded by grant CGL2012-39627-C03-01 from the Spanish Ministry of Economy and Competitiveness (MINECO), which is cofinanced with FEDER support from the European Union. P.G.-T. was an FPI-MINECO fellow. Research by the group of T.G. is funded in part by a grant from the Spanish Ministry of Economy and Competitiveness (BIO2012-37161), a grant from the Qatar National Research Fund (NPRP 5-298-3-086), and a grant from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC (grant agreement no. ERC-2012-StG-310325). L.P.P. was funded through the La Caixa-CRG international fellowship program

Round Robin test on V-shape bio-imaging transfer standard for determination of the Instrument Transfer Function of 3D optical profilers

A V-shape Bio-Transfer-Standard (V-BTS), developed and produced at the University of Helsinki (UH), was measured in two laboratories. In comparison to Siemens Star calibration specimens, the V-BTS performs better at high lateral frequencies close to the diffraction limit of the optical instrument. This peunits deteunining of the Instrument Transfer Function (ITF). The V-BTS features two lipid bilayer steps that partly overlap each other at an angle of 20, with an average height of 4.6 +/- 0.1 nm. The Round Robin (RR) test aims to determine whether the V-BTS and the developed application protocol work with different optical profilers in different laboratories. First the artefact was measured at Sensofar-Tech, S.L. using an S-neox profiler working in Phase Shifting Interferometry mode. Then V-BTS was measured at UH using a custom-built Scanning White Light Interferometer. All measurements done by four different operators at the two laboratories have a range or standard deviation of 0.1 nm which agrees with the theoretical estimates and with measurements done using an atomic force microscope and with a surface plasmon resonance based instrument. The RR results show the applicability of the V-BTS for calibration and for ITF characterization of 3D optical profilers.Peer reviewe