JPEG2000-Based Data Hiding and its Application to 3D Visualization

Non

Near-infrared photoresponse sensitization of solvent additive processed poly(3-hexylthiophene)/fullerene solar cells by a low band gap polymer

With the aim of extending the photoresponse of the poly(3-hexylthiophene)/[6,6]-phenyl-C61-butyric acid methyl ester photovoltaic system into the near-infrared region, a low band gap polymer poly [2,1,3-benzothiadiazole-4,7-diyl[4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b\u27]dithiophene-2, 6-diyl]] was incorporated to make ternary blend solar cells. Solvent additive 1,8-diiodooctane (DIO) was applied to optimize the phase separation in a one-step active layer preparation. Devices fabricated with DIO additive demonstrate an improvement of device power conversion efficiency by 17%, which can be attributed to favorable microscopic structure of the ternary blend with 1:1:0.2 composition processed with DIO and extended absorption on the red side of the visible spectrum up to 900 nm

Une méthode efficace d'insertion de données cachées basée sur JPEG2000 sans perte pour une visualisation scalable et synchronisée de terrain 3D

La visualisation 3D d'un terrain sur des médias de faibles capacités amène à résoudre des problèmes de compression de données et de synchronisation de ces données obtenues, à travers le réseau, à partir de serveurs distants. Le transfert doit aussi pouvoir se faire de façon progressive afin de permettre un affichage sur le média client bien qu'une faible partie des données aura été transmise. Ce travail cherche à résoudre ces problèmes en utilisant le standard JPEG2000 et en particulier le schéma de compression sans perte des données. La compression et la synchronisation des données est assurée grâce à une méthode d'insertion de données cachées permettant de placer toutes les données issues de plusieurs fichiers dans une seule image au format JPEG2000. La scalabilité de la résolution est issue de l'insertion du modèle numérique de terrain, lui même décomposé en ondelettes, dans l'image de texture associée, permettant ainsi un transfert hiérarchique et une synchronisation des données

Testosterone related to age and life-history stages in male baboons and geladas

AbstractDespite significant advances in our knowledge of how testosterone mediates life-history trade-offs, this research has primarily focused on seasonal taxa. We know comparatively little about the relationship between testosterone and life-history stages for non-seasonally breeding species. Here we examine testosterone profiles across the life span of males from three non-seasonally breeding primates: yellow baboons (Papio cynocephalus or P. hamadryas cynocephalus), chacma baboons (Papio ursinus or P. h. ursinus), and geladas (Theropithecus gelada). First, we predict that testosterone profiles will track the reproductive profiles of each taxon across their respective breeding years. Second, we evaluate age-related changes in testosterone to determine whether several life-history transitions are associated with these changes. Subjects include males (>2.5 years) from wild populations of each taxon from whom we had fecal samples for hormone determination. Although testosterone profiles across taxa were broadly similar, considerable variability was found in the timing of two major changes: (1) the attainment of adult levels of testosterone and (2) the decline in testosterone after the period of maximum production. Attainment of adult testosterone levels was delayed by 1 year in chacmas compared with yellows and geladas. With respect to the decline in testosterone, geladas and chacmas exhibited a significant drop after 3 years of maximum production, while yellows declined so gradually that no significant annual drop was ever detected. For both yellows and chacmas, increases in testosterone production preceded elevations in social dominance rank. We discuss these differences in the context of ecological and behavioral differences exhibited by these taxa

Pulse oximetry and photoplethysmographic waveform analysis of the esophagus and bowel

Purpose of review This article reviews the development of novel reflectance pulse oximetry sensors for the esophagus and bowel, and presents some of the techniques used to analyze the waveforms acquired with such devices. Recent findings There has been much research in recent years to expand the utility of pulse oximetry beyond the simple measurement of arterial oxygen saturation from the finger or earlobe. Experimental sensors based on reflectance pulse oximetry have been developed for use in internal sites such as the esophagus and bowel. Analysis of the photoplethysmographic waveforms produced by these sensors is beginning to shed light on some of the potentially useful information hidden in these signals. Summary The use of novel reflectance pulse oximetry sensors has been successfully demonstrated. Such sensors, combined with the application of more advanced signal processing, will hopefully open new avenues of research leading to the development of new types of pulse oximetry-based monitoring techniques

Conducting polymer nanoparticles for targeted cancer therapy

First and second generation photosensitizers used in photodynamic therapy (PDT) have shown promising results in clinical applications, aided by recent improvements in light absorption efficiency and quantum yield of singlet oxygen formation. However, these photosensitizers still have several drawbacks that prevent PDT from being an efficient therapy, including lack of selectivity to diseased tissue, observation of dark toxicity, and hydrophobicity of the sensitizer. Conducting polymers are promising candidates as next generation sensitizers for PDT due to their large extinction coefficients ( \u3e 10(7) L mol(-1) cm(-1)), ability to undergo intersystem crossing to the triplet state at high rates, and triplet energies that are close to that of oxygen. Targeting of conducting polymer poly[2-methoxy-5-(2-ethylhexyl-oxy)-p-phenylenevinylene] (MEH-PPV) nanoparticles to folate receptors (FR) was achieved by development of blended nanoparticles containing amphiphilic polymer polystyrene graft ethylene oxide functionalized with carboxylic acid (PS-PEG-COOH) with chemically active moieties that can be functionalized with folic acid. The resulting organic nanoparticles are buffer stable and exhibit excellent biocompatibility in the dark. The functionalized nanoparticles (FNPs) were studied in OVCAR3 (ovarian cancer cell line, FR+), MIA PaCa2 (pancreatic cell line, FR-), and A549 (lung cancer cell line, marginally FR+). Complete selectivity of the FNPs towards FR+ cell lines was found, and is attributed to the hydrophobicity and large negative zeta potential of the nanoparticles. Quantification of PDT results by MTS assays and flow cytometry show that PDT treatment was fully selective to the FR overexpressing cell line (OVCAR3). No cell mortality was observed for the other cell lines studied here within experimental error

Multi-Scale Predictors of Parasite Risk in Wild Male Savanna Baboons (Papio Cynocephalus)

Several factors are thought to shape male parasite risk in polygynous and polygynandrous mammals, including male-male competition, investment in potentially immunosuppressive hormones, and dispersal. Parasitism is also driven by processes occurring at larger scales, including host social groups and populations. To date, studies that test parasite-related costs of male behavior at all three scales—individual hosts, social groups, and the host population—remain rare. To fill this gap, we investigated multi-scale predictors of helminth parasitism in 97 male savanna baboons (Papio cynocephalus) living in the Amboseli ecosystem in Kenya over a 5-year span. Controlling for multi-scale processes, we found that many of the classic indicators of male mating effort—high dominance rank, testosterone, and glucocorticoids—did not predict helminth infection risk. However, we identified two parasite-related costs associated with male behavior: (i) socially connected males exhibited higher Trichuris trichiura egg counts and greater parasite species richness than socially isolated males and (ii) males with stable group residency exhibited higher parasite species richness than males who frequently dispersed to new social groups. At the population level, males harbored more parasites following periods of drought than rainfall. Lastly, parasites exhibited positive covariance suggesting that infection risk increases if a host already harbors one or more parasite taxa. These results indicate that multi-scale processes are important in driving male parasite risk and that some aspects of male behavior are costly. Together, our results provide an unusually holistic perspective on the drivers of parasite risk in the context of male behaviors and life histories

Androgen correlates of male reproductive effort in wild male long-tailed macaques (Macaca fascicularis): A multi-level test of the challenge hypothesis.

The challenge hypothesis (Wingfield et al., 1990) has been broadly utilised as a conceptual framework to study male androgen correlates of reproductive challenges in mammals. These studies mainly assessed male androgen responsiveness to a general degree of challenge over extended periods of time. Short term co-variation between the socio-sexual challenging context and androgen levels remains, however, largely understudied. We thus aim at providing a multi-level test of the challenge hypothesis by investigating the inter- and intra-individual variations in faecal androgen excretion associated to 1) breeding seasonality, 2) dominance rank, 3) mate-guarding activity and 4) value of the guarded female. We studied long-tailed macaques, a species in which males engage in highly challenging monopolisation of females over discreet periods of time. This particularity allows testing specifically the predicted increase from level B to level C in the challenge hypothesis. The study was carried out during two reproductive seasons on three groups of wild long-tailed macaques. We combined behavioural observations and non-invasive measurements of faecal androgen metabolite (fAM) levels. We found that, as predicted by the challenge hypothesis, male long-tailed macaques respond not only to seasonal but also to short term reproductive challenges by adapting their androgen levels. First, males exhibited a seasonal rise in fAM levels during the mating period which may be triggered by fruit availability as shown by our phenological data. Second, males had increased androgen levels when mate-guarding females and, across mate-guarding periods, males had higher fAM levels when monopolising high-ranking parous females than when monopolising low-ranking ones. Finally, high-ranking males had higher fAM levels than low-ranking males year round. Our study confirms that, in species with a high degree of female monopolisability, androgen may be an important physiological fitness enhancing tool for males by increasing female monopolisation efficiency (in particular with highly valuable females) and helping males to respond to rank take-over challenges

Comparison of non-invasive peripheral venous saturations with venous blood co-oximetry

The estimation of venous oxygen saturations using photoplethysmography (PPG) may be useful as a noninvasive continuous method of detecting changes in regional oxygen supply and demand (e.g. in the splanchnic circulation). The aim of this research was to compare PPG-derived peripheral venous oxygen saturations directly with venous saturation measured from co-oximetry blood samples, to assess the feasibility of non-invasive local venous oxygen saturation. This paper comprises two similar studies: one in healthy spontaneously-breathing volunteers and one in mechanically ventilated anaesthetised patients. In both studies, PPG-derived estimates of peripheral venous oxygen saturations (SxvO2) were compared with co-oximetry samples (ScovO2) of venous blood from the dorsum of the hand. The results were analysed and correlation between the PPG-derived results and co-oximetry was tested for. In the volunteer subjects,moderate correlation (r = 0.81) was seen between SxvO2 values and co-oximetry derived venous saturations (ScovO2), with a mean (±SD) difference of +5.65 ± 14.3% observed between the two methods. In the anaesthetised patients SxvO2 values were only 3.81% lower than SpO2 and tended to underestimate venous saturation (mean difference = –2.67 ± 5.89%) while correlating weakly with ScovO2 (r = 0.10). The results suggest that significant refinement of the technique is needed to sufficiently improve accuracy to produce clinically meaningful measurement of peripheral venous oxygen saturation. In anaesthetised patients the use of the technique may be severely limited by cutaneous arteriovenous shunting