A novel fluorescence-based assay for the rapid detection and quantification of cellular deoxyribonucleoside triphosphates

Current methods for measuring deoxyribonucleoside triphosphates (dNTPs) employ reagent and labor-intensive assays utilizing radioisotopes in DNA polymerase-based assays and/or chromatography-based approaches. We have developed a rapid and sensitive 96-well fluorescence-based assay to quantify cellular dNTPs utilizing a standard real-time PCR thermocycler. This assay relies on the principle that incorporation of a limiting dNTP is required for primer-extension and Taq polymerase-mediated 5-3' exonuclease hydrolysis of a dual-quenched fluorophore-labeled probe resulting in fluorescence. The concentration of limiting dNTP is directly proportional to the fluorescence generated. The assay demonstrated excellent linearity (R(2) > 0.99) and can be modified to detect between ∼0.5 and 100 pmol of dNTP. The limits of detection (LOD) and quantification (LOQ) for all dNTPs were defined as <0.77 and <1.3 pmol, respectively. The intra-assay and inter-assay variation coefficients were determined to be <4.6% and <10%, respectively with an accuracy of 100 ± 15% for all dNTPs. The assay quantified intracellular dNTPs with similar results obtained from a validated LC-MS/MS approach and successfully measured quantitative differences in dNTP pools in human cancer cells treated with inhibitors of thymidylate metabolism. This assay has important application in research that investigates the influence of pathological conditions or pharmacological agents on dNTP biosynthesis and regulation.

A Scheme Design of Cloud + End Technology in Demand Side Management

Demand Side Management (DSM) plays an important role in Smart Grid. It has large scale access points, massive users, heterogeneous infrastructure and dispersive participants. Moreover, cloud computing which is a service model is characterized by resource on-demand, high reliability and large scale integration and so on and the game theory is a useful tool to the dynamic economic phenomena. In this study, a scheme design of cloud + end technology is proposed to solve technical and economic problems of the DSM. The architecture of cloud + end is designed to solve technical problems in the DSM. In particular, a construct model of cloud + end is presented to solve economic problems in the DSM based on game theories. The proposed method is tested on a DSM cloud + end public service system construction in a city of southern China. The results demonstrate the feasibility of these integrated solutions which can provide a reference for the popularization and application of the DSM in china.

Controlled periodic illumination in semiconductor photocatalysis

Controlled periodic illumination is a hypothesis postulated in the early 1990s for enhancing the efficiency of semiconductor photocatalytic reactions. This technique has been proposed to improve photocatalytic efficiency by the nature of photon introduction alone. Before its application in semiconductor photocatalysis, controlled periodic illumination had been investigated in other fields including photosynthesis. This paper presents a detailed review of the state of the art research undertaken on the application of controlled periodic illumination in semiconductor photocatalysis. The review briefly introduces semiconductor photocatalysis, and then presents a detailed explanation of this technique, its importance to photocatalytic efficiency, an overview of previous results of its application in significant studies and present knowledge. Results from previous as well as some of the most recent studies indicate potential applications of controlled periodic illumination in areas other than just the improvement of the efficiency of the photocatalytic process.

The Dark Side of Nudging: The Ethics, Political Economy, and Law of Libertarian Paternalism

Libertarian paternalism, as advanced by Cass Sunstein, is seriously flawed, but not primarily for the reasons that most commentators suggest. Libertarian paternalism and its attendant regulatory implications are too libertarian, not too paternalistic, and as a result are in considerable tension with ‘thick’ conceptions of human dignity. We make four arguments. The first is that there is no justification for a presumption in favor of nudging as a default regulatory strategy, as Sunstein asserts. It is ordinarily less effective than mandates; such mandates rarely offend personal autonomy; and the central reliance on cognitive failures in the nudging program is more likely to offend human dignity than the mandates it seeks to replace. Secondly, we argue that nudging as a regulatory strategy fits both overtly and covertly, often insidiously, into a more general libertarian program of political economy. Thirdly, while we are on the whole more concerned to reject the libertarian than the paternalistic elements of this philosophy, Sunstein’s work, both in Why Nudge?, and earlier, fails to appreciate how nudging may be manipulative if not designed with more care than he acknowledges. Lastly, because of these characteristics, nudging might even be subject to legal challenges that would give us the worst of all possible regulatory worlds: a weak regulatory intervention that is liable to be challenged in the courts by well-resourced interest groups. In such a scenario, and contrary to the ‘common sense’ ethos contended for in Why Nudge?, nudges might not even clear the excessively low bar of doing something rather than nothing. Those seeking to pursue progressive politics, under law, should reject nudging in favor of regulation that is more congruent with principles of legality, more transparent, more effective, more democratic, and allows us more fully to act as moral agents. Such a system may have a place for (some) nudging, but not one that departs significantly from how labeling, warnings and the like already function, and nothing that compares with Sunstein’s apparent ambitions for his new movement.

The Dark Side of Nudging

A podcast of a talk presented at a conference in Berlin organized by the Vervassungsblog on Choice Architecture in Democracies, in January 2015 - Verfassungsblog - Autonomy vs. Technocracy: Libertarian Paternalism revisited

Largest Matching Areas for Illumination and Occlusion Robust Face Recognition

In this paper, we introduce a novel approach to face recognition which simultaneously tackles three combined challenges: 1) uneven illumination; 2) partial occlusion; and 3) limited training data. The new approach performs lighting normalization, occlusion de-emphasis and finally face recognition, based on finding the largest matching area (LMA) at each point on the face, as opposed to traditional fixed-size local area-based approaches. Robustness is achieved with novel approaches for feature extraction, LMA-based face image comparison and unseen data modeling. On the extended YaleB and AR face databases for face identification, our method using only a single training image per person, outperforms other methods using a single training image, and matches or exceeds methods which require multiple training images. On the labeled faces in the wild face verification database, our method outperforms comparable unsupervised methods. We also show that the new method performs competitively even when the training images are corrupted.

Parkinson’s Is Time on Your Side? Evidence for Difficulties with Sensorimotor Synchronization

There is lack of consistent evidence as to how well PD patients are able to accurately time their movements across space with an external acoustic signal. For years, research based on the finger-tapping paradigm, the most popular paradigm for exploring the brain's ability to time movement, has provided strong evidence that patients are not able to accurately reproduce an isochronous interval [i.e., Ref. (1)]. This was undermined by Spencer and Ivry (2) who suggested a specific deficit in temporal control linked to emergent, rhythmical movement not event-based actions, which primarily involve the cerebellum. In this study, we investigated motor timing of seven idiopathic PD participants in event-based sensorimotor synchronization task. Participants were asked to move their finger horizontally between two predefined target zones to synchronize with the occurrence of two sound events at two time intervals (1.5 and 2.5 s). The width of the targets and the distance between them were manipulated to investigate impact of accuracy demands and movement amplitude on timing performance. The results showed that participants with PD demonstrated specific difficulties when trying to accurately synchronize their movements to a beat. The extent to which their ability to synchronize movement was compromised was found to be related to the severity of PD, but independent of the spatial constraints of the task.

Power Spectral Density Side-Channel Attack Overlapping Window Method

Cryptographic algorithms have been designed to be computationally secure, however it has been shown that when they are implemented in hardware, that these devices leak side channel information that can be used to mount an attack that recovers the secret encryption key. In this paper an overlapping window power spectral density (PSD) side channel attack, targeting an FPGA device running the Advanced Encryption Standard is proposed. This improves upon previous research into PSD attacks by reducing the amount of pre-processing (effort) required. It is shown that the proposed overlapping window method requires less processing effort than that of using a sliding window approach, whilst overcoming the issues of sampling boundaries. The method is shown to be effective for both aligned and misaligned data sets and is therefore recommended as an improved approach in comparison with existing time domain based correlation attacks.

Multifunctional nanoparticles for MR and fluorescence imaging

In the past few years a new generation of multifunctional nanoparticles (NPs) has been proposed for biomedical applications, whose structure is more complex than the structure of their predecessor monofunctional counterparts. The development of these novel NPs aims at enabling or improving the performance in imaging, diagnosis and therapeutic applications. The structure of such NPs comprises several components exhibiting various functionalities that enable the nanoparticles to perform multiple tasks simultaneously, such as active targeting of certain cells or compartmentalization, imaging and delivery of active drugs. This thesis presents two types of bimodal bio-imaging probes and describes their physical and chemical properties, namely their texture, structure, and 1H dynamics and relaxometry, in order to evaluate their potential as MRI contrast agents. The photoluminescence properties of these probes are studied, aiming at assessing their interest as optical contrast agents. These materials combine the properties of the trivalent lanthanide (Ln3+) complexes and nanoparticles, offering an excellent solution for bimodal imaging. The designed T1- type contrast agent are SiO2@APS/DTPA:Gd:Ln or SiO2@APS/PMN:Gd:Ln (Ln= Eu or Tb) systems, bearing the active magnetic center (Gd3+) and the optically-active ions (Eu3+ and Tb3+) on the surface of silica NPs. Concerning the relaxometry properties, moderate r1 increases and significant r2 increases are observed in the NPs presence, especially at high magnetic fields, due to susceptibility effects on r2. The Eu3+ ions reside in a single low-symmetry site, and the photoluminescence emission is not influenced by the simultaneous presence of Gd3+ and Eu3+. The presence of Tb3+, rather than Eu3+ ion, further increases r1 but decreases r2. The uptake of these NPs by living cells is fast and results in an intensity increase in the T1-weighted MRI images. The optical features of the NPs in cellular pellets are also studied and confirm the potential of these new nanoprobes as bimodal imaging agents. This thesis further reports on a T2 contrast agent consisting of core-shell NPs with a silica shell surrounding an iron oxide core. The thickness of this silica shell has a significant impact on the r2 and r2* relaxivities, and a tentative model is proposed to explain this finding. The cell viability and the mitochondrial dehydrogenase expression given by the microglial cells are also evaluated.

“Should we all be on Marx’s side?” Contributions of post-marxist discourse theory to the historiography of communism

Drawing on post-marxist discourse theory inspired by the writings of Ernesto Laclau and Chantal Mouffe, this article puts the case for a literature on communism situated at the crossroads of critical theory, cultural studies and historiography. Specific illustration is provided by the author's own research on British communism and the Spanish Civil War. However, the scope of the article is much broader and it is intended as a contribution to the theoretical discussion of future possibilities for communist history-writing. The article concludes that discourse should be regarded neither as a flat surface of tightly knit signifiers nor as an impenetrable monolith of meaning systems. Rather, it should be seen as an inherently dynamic phenomenon, with its own condensations and dispersions along the historical continuum. In this lies its significance for historians of communism.

On the solvation in lipid bilayers measured by pyrene fluorescence: thermal and molecular composition influence on equivalent polarity in lipidic mixtures

Phosphatidylcholine (PC), sphingomyelin (SM) and cholesterol (CHOL) are major constituents of mammalian cell membranes. DPPC/CHOL and DPPC/DMPC are well-known binary mixtures. POPC/CHOL, DOPC/CHOL, egg-SM/CHOL, egg-SM/POPC and egg-SM/DOPC are less studied, but also important for the comprehension of the POPC/egg-SM/CHOL mixtures. These provide complex media for which polarity is hard to access. It is mainly determined by the water penetrating the bilayer (unevenly distributed creating a polarity gradient), though the influence of the dipoles from phospholipids (e.g. –PO, –CO, –OH) and the double bond in the steroid ring of CHOL cannot be neglected. CHOL derivatives are an interesting tool to verify the influence of the double bonds in the polarization of its surroundings. Pyrene fluorescence was used to access an equivalent polarity (associated to the dielectric constant) near the lipid/water interface of lipid bilayers. POPC/CHOL and DOPC/CHOL have similar thermal behavior and variation with CHOL content, though for lower CHOL content the equivalent polarity is higher for the DOPC/CHOL mixtures. The studies with DPPC and DMPC showed that pyrene does not seem to have a marked preference for either ordered or disordered phases. For DPPC/CHOL and egg-SM/CHOL the highlight goes to the behavior of the mixtures at higher CHOL amounts, where there is a substantial change in the thermal behavior and polarity values especially for the egg-SM/CHOL mixture. Egg-SM/POPC and egg-SM/DOPC show different behavior depending on which phospholipid has a higher molar proportion. The ternary mixtures analyzed do not exhibit significant differences, though there is the indication of the existence of a more ordered environment at lower temperatures and a less ordered environment for higher temperatures. The presence of 7DHC or DCHOL in egg-SM bilayers showed a tendency for the same behavior detected upon mixing higher amounts of CHOL.

This Side of Paradise due date card

This is a due date card for the book titled This Side of Paradise, with stamped dates from 1939-1941.

The Ms. Parma 1959 in the context of portuguese hebrew illumination

Tese de mestrado, Arte, Património e Teoria do Restauro, Universidade de Lisboa, Faculdade de Letras, 2011

Peroxide-based hybrid and prodrug antimalarials to deliver cysteine protease inhibitors into the parasitic food vacuole

Tese de doutoramento, Farmácia (Química Farmacêutica e Terapêutica), Universidade de Lisboa, Faculdade de Farmácia, 2014