Favorite Candidate Research Articles

Fabrication of high thermal conductive Al–cBN ceramic sinters by high temperature high pressure method

Al–cBN ceramic sinters were fabricated by sintering micro-powder mixture of Al and cBN under high temperature and high pressure condition. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) elemental mapping analyses and laser flashing thermal conductivity measurements were performed to investigate the sintering properties and thermal conductivity of the Al–cBN ceramic sinters. XRD analysis revealed these Al–cBN ceramic sinters were composed of a large portion of cBN and of a small portion of AlN, and very little amount of AlB 12 and hBN. Formation of boundary phase resulted in the rapid densification of the sinters, as well as the increase of their relative density with increasing Al additions. The Al–cBN ceramic sinters have a maximum thermal conductivity of about 1.94 W/cm K at room temperature and a much higher value of about 2.04 W/cm K at 200 °C. Their high thermal conductivity over that of AlN–hBN composites promise Al–cBN ceramic sinters favorite candidates as high efficiency heat sink materials for wide band gap semiconductors.

No-Show Paradoxes under Parliamentary Agendas

It may happen that the favorite candidate of a voter loses an election if that voter votes honestly, but gets elected if the voter abstains. Such a situation is known in the social choice literature under the name of no-show paradox. This paper is devoted to the evalution of the likelihood of that phenomenon under parliamentary voting rules.

Enzymes for Antifouling Strategies

During the past decades, much effort has been made to find efficient alternative solutions to prevent and/or disrupt the adhesion of fouling organisms to surfaces. The use of enzymes emerges among the investigated approaches as one of the favorite candidate antifouling technologies due to enzymes' biodegradability and affordable prices. An overview of the different enzymatic antifouling strategies is presented, highlighting the most promising groups of enzymes, and their utilization upon surface-confinement to control biofouling. While the main strategies to control marine biofouling include the degradation of secreted adhesives and the production of antifouling compounds, the main concepts to control pathogenic biofilms are based on cell lysis and on the degradation of extracellular matrix polymers. Although immobilization can improve enzyme stability, activity and antifouling performance, up to date relatively few scientific articles concerning the use of immobilized enzymes to control biofouling have been published. The successful incorporation of enzymes into coatings yielding surfaces with broad antifouling spectrum and long-term efficacy remains a challenge.

The (Elusive) Theory of Everything

Stephen Hawking's work on black holes and the origin of the universe is arguably the most concrete progress theoretical physicists have made toward reconciling Einstein's gravitation and quantum physics into one final theory of everything. Physicists have a favorite candidate for such a theory, string theory, but it comes in five different formulations, each covering a restricted range of situations. A network of mathematical connections, however, links the different string theories into one overarching system, enigmatically called M-theory: perhaps the network is itself the final theory. In a new book, The Grand Design, Hawking and Caltech physicist Leonard Mlodinow argue that the quest to discover a final theory may in fact never lead to a unique set of equations. Every scientific theory, they write, comes with its own model of reality, and it may not make sense to talk of what reality actually is. This essay is based on that book.

Scalar mesons and glueballs in Dp-Dq hard-wall models

We investigate the light scalar mesons and glueballs in the Dp-Dq hard-wall models, including D3-Dq, D4-Dq, and D6-Dq systems. It is found that only in the D4-D6 and D4-D8 hard-wall models are the predicted masses of the q̄q scalar meson f0 scalar glueball consistent with their experimental or lattice results. This indicates that D4-D6 and D4-D8 hard-wall models are the favorite candidates of the realistic holographic QCD model.

Wishful Thinking in the 2008 U.S. Presidential Election

In elections, political preferences are strongly linked to the expectations of the electoral winner—people usually expect their favorite candidate to win. This link could be driven by wishful thinking (a biasing influence of preferences), driven by a biasing influence of expectations on one’s wishes, or produced spuriously. To examine these competing possibilities in the 2008 U.S. presidential election, a longitudinal study assessed uncommitted young voters’ electoral expectations and preferences over four time points during the month before the election. The findings indicated clear support for wishful thinking: Over time, people’s preferences shaped their expectations, but the reverse was not the case. Moreover, these relations were larger among those more strongly identified with their political party and held even when perceptions of general candidate popularity were taken into account. Finally, changes in electoral expectations were consequential, as they shaped disappointment in the electoral results even after taking candidate preferences into account.

The Clamp Loader Assembles the β Clamp onto Either a 3′ or 5′ Primer Terminus: THE UNDERLYING BASIS FAVORING 3′ LOADING

Clamp loaders assemble sliding clamps onto 3' primed sites for DNA polymerases. Clamp loaders are thought to be specific for a 3' primed site, and unable to bind a 5' site. We demonstrate here that the Escherichia coli gamma complex clamp loader can load the beta clamp onto a 5' primed site, although with at least 20-fold reduced efficiency relative to loading at a 3' primed site. Preferential clamp loading at a 3' site does not appear to be due to DNA binding, as the clamp loader forms an avid complex with beta at a 5' site. Preferential loading at a 3' versus a 5' site occurs at the ATP hydrolysis step, needed to close the ring around DNA. We also address DNA structural features that are recognized for preferential loading at a 3' site. Although the single-stranded template strand extends in opposite directions from 3' and 5' primed sites, thus making it a favorite candidate for distinguishing between 3' and 5' sites, the single-strand polarity at a primed template junction does not determine 3' site selection for clamp loading. Instead, we find that clamp loader recognition of a 3' site lies in the duplex portion of the primed site, not the single-strand portion. We present evidence that the beta clamp facilitates its own loading specificity for a 3' primed site. Implications to eukaryotic clamp loader complexes are proposed.

Hybrid structure in PCL-HAp scaffold resulting from biomimetic apatite growth

Polymer-ceramic composites are favourite candidates when aiming to replace bone tissue. We present here scaffolds made of polycaprolactone-hydroxyapatite (PCL-HAp) composites, and investigate in vitro mineralisation of the scaffolds in SBF after or without a nucleation treatment. In vitro bioactivity is enhanced by HAp incorporation as well as by nucleation treatment, as demonstrated by simulated body fluid (SBF) mineralization. Surprisingly, we obtained a hybrid interconnected organic-inorganic structure, as a result of micropore invasion by biomimetic apatite, which results in a mechanical strengthening of the material after two weeks of immersion in SBF92. The presented scaffolds, due to their multiple qualities, are expected to be valuable supports for bone tissue engineering.

On YORP-induced spin deformations of asteroids

The alteration of the spin states of small Solar-System bodies by the YORP thermal effect has recently become a plausible and, for some, the favorite candidate for the formation of binary asteroids. The idea is that if an asteroid is slowly spun up to a state where some strength measure is exceeded; it can no longer remain rigid and adjusts to a new configuration. Such a process might involve global fission, global shape changes without fission, or gradual surface mass loss with subsequent mass re-accumulations forming a secondary body. Here I analyze the changes in the shape, spin, and state during slowly increasing angular momentum of rubble-pile, self-gravitating, homogeneous ellipsoidal bodies undergoing homogeneous motions. I use, as appropriate for rubble-pile asteroids, the strength models of granular materials with zero tensile strength (cohesionless but arbitrary dilatancy); those are characterized by the “angle of friction” material constant. There are distinct limit spins depending on that angle of friction and the shape, which were previously presented [Holsapple, K.A., 2001. Icarus 154, 432–448; Holsapple, K.A., 2004. Icarus 172, 272–303]. Here the deformations and state changes when the angular momentum is slowly increased from that of a limit spin state are determined, to study the YORP processes. When a body is at its limit spin and the angular momentum increases further, the body deforms in a unique way along definite paths in the ellipsoidal shape space: it evolves as an elongating shape with an increasing rotational inertia, which in most cases produces a decreasing spin. I give exact analytical solutions for those shape and spin histories, as well as the histories of the mass density, angular momentum and energy. Comparison to other approaches is made.

A fair distributed resource allocation method in UWB wireless PANs with WiMedia MAC

The WiMedia alliance has specified a distributed medium access control (WiMedia MAC) protocol based on ultra wideband (UWB) for high data rate WPANs (HR-WPANs). The merits of WiMedia MAC such as distributed nature and high data rate make it a favorite candidate in HR-WPAN. Although QoS parameters such as the range of service rates are provided to a traffic stream, the WiMedia MAC is not able to use the QoS parameters and to determine or adjust a service rate using the QoS parameters for the traffic stream. In this paper, we propose a fair and adaptive resource allocation method that allocates time slots to isochronous streams according to QoS parameters and the current traffic load condition in a fully distributed manner. Although the traffic load condition changes, each device independently recognizes the changes and calculates fair and maximum allowable service rates for traffic streams. From the numerical and simulation results, it is proved that the proposed method achieves high capacity of traffic streams and fair QoS provisioning under various traffic load condition.

Voces Populi and the Art of Listening

The strategy most damaging to many preferential election methods is to give insincerely low rank to the main opponent of one's favorite candidate. Theorem 1 determines the 3-candidate Condorcet method that minimizes the number of noncyclic profiles allowing this strategy. Theorems 2, 3, and 4 establish conditions for an anonymous and neutral 3-candidate single-seat election to be monotonic and still avoid this strategy completely. Plurality elections combine these properties; among the others conditional IRV gives the strongest challenge to the plurality winner. Conditional IRV is extended to any number of candidates. Theorem 5 is an impossibility of Gibbard-Satterthwaite type, describing 3 specific strategies that cannot all be avoided in meaningful anonymous and neutral elections.

The Real Debate

We in the United States are sliding down a ramp that will take us, in just 4 days, to the much anticipated Super Tuesday in the presidential nomination cycle, when voters in over 20 states participate in preliminary elections to select their favorite candidate. I have prepared for this by watching, in alternating stages of boredom and disbelief, the numerous debates staged by the creative powers who run television. I wonder whether the same sensations haven9t affected our scientific colleagues in other nations, where leadership is decided in an atmosphere that is, well, a bit more stately. Here it may be too late to change anyone9s mind about their vote on 5 February, but perhaps between now and the culminating summer conventions that will announce the final party candidates, we can have a debate focusing on the candidates9 views about science and technology.

Illusions of Managing History: The Enduring Relevance of Reinhold Niebuhr

January/February 2008 Historically Speaking 23 Illusions of Managing History: The Enduring Relevance of Reinhold Niebuhr* AndrewJ. Bacevich Reinhold Niebuhr, a towering presence in American intellectual life from the 1930s through the 1960s, thought deeply about the dilemmas confronting the United States as a consequence of its emergence as a global superpower. The truths he spoke are uncomfortable ones. They do not easily translate into sound bites suitable for the Sunday morning talk shows. Nor do they offer material from which to weave the sort of stump speech likely to boost the poll numbers of your favorite candidate in Iowa or New Hampshire. Four of those truths merit particular attention at present. They are the persistent sin of American Exceptionalism; the indecipherability of history; the false allure of simple solutions; and, finally, the imperative of appreciating the limits of power. One persistent theme of Niebuhr's writings on foreign policy concerns the difficulty that Americans have in seeing themselves as they really are. "Perhaps the most significant moral characteristic of a nation," he declared in 1932, "is its hypocrisy."' Niebuhr did not exempt his own nation from that judgment. The chief distinguishing feature of American hypocrisy lies in the conviction that America's very founding was a providential act, both an expression of divine favor and a summons to serve as God's chosen instrument . The Anglo-American colonists settling these shores, according to Niebuhr, saw it as America 's purpose "to make a new beginning in a corrupt world." They believed "that we had been called out by God to create a new humanity."2They believed further that this covenant with God marked America as a new Israel. As a Chosen People possessingwhat Niebuhr referred to as a "Messianic consciousness," Americans came to see themselves as set apart, their motives irreproachable , their actions not to be judged by standards applied to others." "Every nation has its own form of spiritual pride," Niebuhr observed in The Irony of American History. "Our version is that our nation turned its back upon the vices of Europe and made a new beginning." Even after World War II, he wrote, the United States remained "an adolescent nation , with illusions of childlike innocency."3 Indeed, the outcome of World War II, vaulting the United States to the apex of world power, seemed to affirm that the nation enjoyed God's favor and was doing God's work. Such illusions have proven remarkably durable. * On October 9, 2007, AndrewJ. Bacevich delivered Boston University 's 2007 University Lecture. We publish a substantial excerpt of the lecture here; an expanded version of the lecture appeared in theJanuary 2008 issue of WorldAffairs. Reinhold Niebuhr speaking at the Union Theological Seminary , February 1, 1959. (Photo by Walter Sanders/Time Life Pictures/Getty Images). We see them in the way that President Bush, certain of the purity of U.S. intentions in Iraq, shrugs off responsibility for the calamitous consequences ensuing from his decision to invade that country. We see them also in the way that the administration insists thatAbu Ghraib or Guantanamo or the policy of secret rendition that delivers suspected terrorists into the hands of torturers in no way compromises U.S. claims of support for human rights and die rule of law. It follows that only cynics or scoundrels would dare suggest that more sordid considerations might have influenced the American choice for war or that incidents like Abu Ghraib signify something other than simply misconduct by a handful of aberrant soldiers . As Niebuhr wrote, when we swathe ourselves in self-regard, it's but a short step to concluding that "onlymalice could prompt criticism of anyof ouractions "—an insight that goes far to explain the outrage expressed by senior U.S. officials back in 2003 when "Old Europe" declined to endorse the war.' In Niebuhr's view, America's rise to power derived less from divine favor than from good fortune combined with a fierce determination to convert that good fortune into wealth and power. The good fortune —Niebuhr referred to it as "America, rocking in the cradle of its continental security"—came in the form of a vast landscape, rich in resources, ripe for exploitation , and...

Chaperones as integrators of cellular networks: Changes of cellular integrity in stress and diseases

The complex integrity of the cells and its sudden, but often predictable changes can be described and understood by the topology and dynamism of cellular networks. All these networks undergo both local and global rearrangements during stress and development of diseases. Here, we illustrate this by showing the stress-induced structural rearrangement of the yeast protein-protein interaction network (interactome). In an unstressed state, the yeast interactome is highly compact, and the centrally organized modules have a large overlap. During stress, several original modules became more separated, and a number of novel modules also appear. A few basic functions such as theproteasome preserve their central position; however, several functions with high energy demand, such the cell-cycle regulation loose their original centrality during stress. A number of key stress-dependent protein complexes, such as the disaggregation-specific chaperone, Hsp104 gain centrality in the stressed yeast interactome. Molecular chaperones, heat shock, or stress proteins became established as key elements in our molecular understanding of the cellular stress response. Chaperones form complex interaction networks (the chaperome) with each other and their partners. Here, we show that the human chaperome recovers the segregation of protein synthesis-coupled and stress-related chaperones observed in yeast recently. Examination of yeast and human interactomes shows that chaperones 1) are intermodular integrators of protein-protein interaction networks, which 2) often bridge hubs and 3) are favorite candidates for extensive phosphorylation. Moreover, chaperones 4) become more central in the organization of the isolated modules of the stressed yeast protein-protein interaction network, which highlights their importance in the decoupling and recoupling of network modules during and after stress. Chaperone-mediated evolvability of cellular networks may play a key role in cellular adaptation during stress and various polygenic and chronic diseases, such as cancer, diabetes or neurodegeneration.

Dark Matter Search with the ANTARES Neutrino Telescope

Neutrino telescopes are a promising tool for Astroparticle Physics. Neutrinos are neutral, stable and weakly interacting, so these telescopes will open a new window to observe astrophysical objects like AGNs, GRBs or micro-quasars and will allow to look for new Physics, such as dark matter candidates. WIMPs, weakly interacting massive particles, are a possible constituent of dark matter. WIMPs can scatter and become gravitationally trapped in massive objects like the Sun, the Earth or the Galactic Center. Supersymmetry offers several candidates for WIMPs. In the Minimal Supersymmetric Standard Model (MSSM), the lightest supersymmetric particle is stable in most scenarios because of R-parity conservation. In many MSSM models, the favorite candidate is the lightest neutralino. Their annihilation could give rise to detectable rates of high energy neutrinos. Other possible WIMPs, like the lightest Kaluza-Klein (LKK) particle occuring in scenarios with extra-dimensions, can also be investigated. Neutrino telescopes have complementary potential with respect to direct searches, particularly in the range of large neutralino masses. In this paper we will discuss the prospects for dark matter searches with the ANTARES neutrino telescope that is presently under construction in the Mediterranean Sea.

Apophaticism in Thomas Aquinas: a re-reformulation and recommendation

Apophaticism has become quite fashionable, for political as well as philosophical reasons: political, because apophaticism opens up space between God and oppressive God-talk; and philosophical, because apophaticism provides theological warrant for embracing our Kantian limits. A correlate fashion has been to broaden our sense of who belongs to the ‘apophatic tradition’ – and Thomas Aquinas has been one of the favourite candidates for such reconsideration. Contrary to this trend, I argue that apophaticism is not a ‘rule’ for Thomas – far from it. Apophaticism is, ironically, one of the steps in Thomas's strategy to assemble the conceptual resources necessary for making positive statements about God. That strategy, in brief, consists of five moves: first, Thomas provisionally defines ‘God’ as the sufficient cause of certain effects ascribed to God; second, using the via negativa to rule out whatever is incompatible with a ‘God’ so specified, he argues that God-in-Godself can be identified with ‘God’; third, Thomas identifies ‘being’ as the common term between God and creatures (which is licit because, Thomas claims, being is not a genus); fourth, he argues that all beings tend toward their perfection, and that God is this perfection; and fifth, he concludes that this tendency-toward-God funds the making of meaningful, positive statements about God-in-Godself.

Identification of linear slow sausage waves in magnetic pores

AbstractThe analysis of an 11-hour series of high resolution white light observations of a large pore in the sunspot group NOAA 7519, observed on 5 June 1993 with the Swedish Vacuum Solar Telescope at La Palma on Canary Islands, has been recently described by Dorotovičet al. (2002). Special attention was paid to the evolution of a filamentary region attached to the pore, to horizontal motions around the pore, and to small-scale morphological changes. One of the results, relevant to out work here, was the determination of temporal area evolution of the studied pore where the area itself showed a linear trend of decrease with time at an average rate of −0.23 Mm2h−1during the entire observing period. Analysing the time series of the are of the pore, there is strong evidence that coupling between the solar interior and magnetic atmosphere can occur at various scales and that the referred decrease of the area may be connected with a decrease of the magnetic field strength according to the magnetic field-to-size relation. Periods of global acoustic, e.g.p-mode, driven waves are usually in the range of 5–10 minutes, and are favourite candidates for the coupling of interior oscillations with atmospheric dynamics. However, by assuming that magneto-acoustic gravity waves may be there too, and may act as drivers, the observed periodicities (frequencies) are expected to be much longer (smaller), falling well within the mMHz domain. In this work we determine typical periods of such range in the area evolution of the pore using wavelet analysis. The resulted periods are in the range of 20–70 minutes, suggesting that periodic elements of the temporal evolution of the area of this studied pore could be linked to, and considered as, observational evidence of linear low-frequency slow sausage (magneto-acoustic gravity) waves in magnetic pores. This would give us further evidence on the coupling of global solar oscillations to the overlaying magnetic atmosphere.

Sophisticated approval voting, ignorance priors, and plurality heuristics: A behavioral social choice analysis in a Thurstonian framework.

This project reconciles historically distinct paradigms at the interface between individual and social choice theory, as well as between rational and behavioral decision theory. The authors combine a utility-maximizing prescriptive rule for sophisticated approval voting with the ignorance prior heuristic from behavioral decision research and two types of plurality heuristics to model approval voting behavior. When using a sincere plurality heuristic, voters simplify their decision process by voting for their single favorite candidate. When using a strategic plurality heuristic, voters strategically focus their attention on the 2 front-runners and vote for their preferred candidate among these 2. Using a hierarchy of Thurstonian random utility models, the authors implemented these different decision rules and tested them statistically on 7 real world approval voting elections. They cross-validated their key findings via a psychological Internet experiment. Although a substantial number of voters used the plurality heuristic in the real elections, they did so sincerely, not strategically. Moreover, even though Thurstonian models do not force such agreement, the results show, in contrast to common wisdom about social choice rules, that the sincere social orders by Condorcet, Borda, plurality, and approval voting are identical in all 7 elections and in the Internet experiment.

Indirect detection of WIMPs

There is compelling evidence for the existence of dark matter in the Universe. One of the favourite candidates is a Weakly Interacting Massive Particle (WIMP). We will here focus on indirect ways to search for WIMPs and compare their advantages and disadvantages, the emphasis though will be on searches via neutrinos from the Earth/Sun. As a concrete WIMP example, we will focus on the neutralino that arises in supersymmetric extensions of the standard model.

The fairest vote of all.

This article discusses voting systems. Most American and French citizens--indeed, those of democracies the world over--spend little time contemplating their voting systems. In the U.S., many voters asked why the most popular candidate lost the election of 2000. But based on research by ourselves and colleagues, we can address a more fundamental issue: What kinds of systems, be they for electing national leaders or student council presidents, go furthest toward truly representing the wishes of the voters? In most national presidential electoral systems, a voter chooses only his or her favorite candidate rather than ranking them all. If just two candidates compete, this limitation makes no difference. But with three or more candidates, it can matter a great deal. Such ambiguity can be resolved by having voters submit complete rankings. If four candidates are running, each voter assigns four points to his or her favorite, three to the next favorite, two to the next, and one to the least favorite. The winner is the candidate with the biggest total.