1,909 research outputs found

    Comparison of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in the serum of hypothyroxinemic and euthyroid dogs.

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    ObjectiveTo determine the profile of 14 polybrominated diphenyl ethers (PBDEs) and 23 polychlorinated biphenyls (PCBs) in serum of domestic canines and whether this was predictive of thyroid hormone status.SamplesSerum samples were collected from 51 client-owned dogs visiting the University of California Davis William R. Pritchard Veterinary Medical Teaching Hospital during 2012 to 2016 for routine appointments. Fifteen dogs were diagnosed with hypothyroxinemia while 36 were euthyroid.ProceduresConcentrations of PBDEs and PCBs in canine serum samples were measured by gas chromatography mass spectrometry. Logistic regression analysis was used to determine the association between the presence/absence of canine hypothyroxinemia and the serum concentration of individual PBDE or PCB congeners.ResultsThe median concentrations of total PBDE and PCB congeners in the hypothyroxinemic group were 660 and 1,371 ng/g lipid, respectively, which were higher than concentrations detected in the control group. However, logistic regression analysis determined that current concentrations of PBDEs and PCBs in canines were not significantly associated with hypothyroxinemia. BDE 183 was the only congener showing near significance (p = 0.068).ConclusionsPBDE and PCB congeners were detected in all canine samples confirming ongoing exposure to these pollutants. Because household dogs share the human environment, they may serve as biosentinels of human exposure to these contaminants

    Revolutionary Disobedience

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    Over the past few decades, civil disobedience has become one of the most widely studied subjects in jurisprudence. Scholars such as Rawls and Dworkin have offered their unique reflections on the subject. Whilst many have made great contributions to clarify its purposes and justifications, they have neglected one of the most important and fundamental forms of political disobedience, namely revolutionary disobedience. Unlike an act of civil disobedience, which recognizes governmental authority and legitimacy, revolutionary disobedience explicitly denies and challenges them. Manifested as a rupture between the constituent power (ruled/governed) and constituted power (ruler/governor) in a given state, it is designed to terminate the authority relationship between them, signifying a state of exception, which deviates from the juridical norm. Contrary to traditional civil disobedience, which reveals the unjust nature of a particular law or policy, thereby fostering constitutional changes if the government so allows, in a case of revolutionary disobedience the people directly announce their presence to oust the government from office and even reshape the constitutional order as well as create a new state. It is an exertion of popular sovereignty, reengaging the people in the collective authorship of the sovereign will. Hence, an act of revolutionary disobedience is an exercise of self-determination and is inherently democratic. In this Article, I construct a theory of revolutionary disobedience and analyze its correlation with the people (nation), the constitution, the state, and the democratic boundary problem. The theory is further developed with the highlight of two political disobedience movements: the Indian Independence Movement and the Umbrella Movement of Hong Kong. The study exposes the limits of conventional civil disobedience and showcases the ground-breaking role for revolutionary disobedience for constitutional creation. Defending that Hongkongers are a people, I suggest that they can invoke revolutionary disobedience as a direct course of action to engage themselves in the higher law-making of the land and forfeit the authority of the government. The final section offers a reply to the Hong Kong Bar Association, which has accused the last phase of the Umbrella Movement of damaging the rule of law. I make a rebuttal to such contention and further analyze how revolutionary disobedience is perfectly compatible with the rule of law

    Adaptive multi-scale retinex algorithm for contrast enhancement of real world scenes

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    Contrast enhancement is a classic image restoration technique that traditionally has been performed using forms of histogram equalization. While effective these techniques often introduce unrealistic tonal rendition in real-world scenes. This paper explores the use of Retinex theory to perform contrast enhancement of real-world scenes. We propose an improvement to the Multi-Scale Retinex algorithm which enhances its ability to perform dynamic range compression while not introducing halo artifacts and greying. The algorithm is well suited to be implemented on the GPU and by doing so real-time processing speeds are achieved

    The Anomalous Trajectories of the Pioneer Spacecraft

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    Because of their unique designs, the Pioneer 10 and 11 spacecraft have provided the cleanest Doppler, deep-space navigation data. Analysis of this data can be interpreted as showing an anomalous acceleration of these craft directed towards the Sun of aP∌8×10−8cm/s2a_P \sim 8 \times 10^{-8} {\rm cm/s}^2. The background of this discovery and the significance of the result are discussed.Comment: 5 pages, 2 figures, to be published in the Proceedings of the Second Meeting on CPT and Lorentz Symmetr

    Quantum Transport and Field Induced Insulating States in Bilayer Graphene pnp Junctions

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    We perform transport measurements in high quality bilayer graphene pnp junctions with suspended top gates. At a magnetic field B=0, we demonstrate band gap opening by an applied perpendicular electric field, with an On/Off ratio up to 20,000 at 260mK. Within the band gap, the conductance decreases exponentially by 3 orders of magnitude with increasing electric field, and can be accounted for by variable range hopping with a gate-tunable density of states, effective mass, and localization length. At large B, we observe quantum Hall conductance with fractional values, which arise from equilibration of edge states between differentially-doped regions, and the presence of an insulating state at filling factor {\nu}=0. Our work underscores the importance of bilayer graphene for both fundamental interest and technological applications.Comment: 4 figures, to appear in Nano Lett. Minor typos correcte

    Search for a Standard Explanation of the Pioneer Anomaly

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    The data from Pioneer 10 and 11 shows an anomalous, constant, Doppler frequency drift that can be interpreted as an acceleration directed towards the Sun of a_P = (8.74 \pm 1.33) x 10^{-8} cm/s^2. Although one can consider a new physical origin for the anomaly, one first must investigate the contributions of the prime candidates, which are systematics generated on board. Here we expand upon previous analyses of thermal systematics. We demonstrate that thermal models put forth so far are not supported by the analyzed data. Possible ways to further investigate the nature of the anomaly are proposed.Comment: Changes made for publicatio

    The Apparent Anomalous, Weak, Long-Range Acceleration of Pioneer 10 and 11

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    Recently we reported that radio Doppler data generated by NASA's Deep Space Network (DSN) from the Pioneer 10 and 11 spacecraft indicate an apparent anomalous, constant, spacecraft acceleration with a magnitude ∌8.5×10−8\sim 8.5\times 10^{-8} cm s−2^{-2}, directed towards the Sun (gr-qc/9808081). Analysis of similar Doppler and ranging data from the Galileo and Ulysses spacecraft yielded ambiguous results for the anomalous acceleration, but it was useful in that it ruled out the possibility of a systematic error in the DSN Doppler system that could easily have been mistaken as a spacecraft acceleration. Here we present some new results, including a critique suggestions that the anomalous acceleration could be caused by collimated thermal emission. Based partially on a further data for the Pioneer 10 orbit determination, the data now spans January 1987 to July 1998, our best estimate of the average Pioneer 10 acceleration directed towards the Sun is ∌7.5×10−8\sim 7.5 \times 10^{-8} cm s−2^{-2}.Comment: Latex, 7 pages and 2 figures. Invited talk at the XXXIV-th Rencontres de Moriond Meeting on Gravitational Waves and Experimental Gravity. Les Arcs, Savoi, France (January 23-30,1999). Corrected typo

    Aggregating multiple body sensors for analysis in sports

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    Real time monitoring of the wellness of sportspersons, during their sporting activity and training, is important in order to maximise performance during the sporting event itself and during training, as well as being important for the health of the sportsperson overall. We have combined a suite of common, off-the-shelf sensors with specialist body sensing technology we are developing ourselves and constructed a software system for recording, analysing and presenting sensed data gathered from a single player during a sporting activity, a football match. We gather readings for heart rate, galvanic skin response, motion, heat flux, respiration, and location (GPS) using on-body sensors, while simultaneously tracking player activity using a combination of a playercam video and pitch-wide video recording. We have aggregated all this sensed data into a single overview of player performance and activity which can be reviewed, post-event. We are currently working on integrating other non-invasive methods for real-time on-body monitoring of sweat electrolytes and pH via a textile-based sweat sampling and analysis platform. Our work is heading in two directions; firstly from post-event data aggregation to real-time monitoring, and secondly, to convert raw sensor readings into performance indicators that are meaningful to practitioners in the field

    Sensor node localisation using a stereo camera rig

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    In this paper, we use stereo vision processing techniques to detect and localise sensors used for monitoring simulated environmental events within an experimental sensor network testbed. Our sensor nodes communicate to the camera through patterns emitted by light emitting diodes (LEDs). Ultimately, we envisage the use of very low-cost, low-power, compact microcontroller-based sensing nodes that employ LED communication rather than power hungry RF to transmit data that is gathered via existing CCTV infrastructure. To facilitate our research, we have constructed a controlled environment where nodes and cameras can be deployed and potentially hazardous chemical or physical plumes can be introduced to simulate environmental pollution events in a controlled manner. In this paper we show how 3D spatial localisation of sensors becomes a straightforward task when a stereo camera rig is used rather than a more usual 2D CCTV camera
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