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The dark side
Gregory A Petsko
Genome Biology , 2000, DOI: 10.1186/gb-2000-1-3-comment1003
Abstract: We will all face the dark side before long, as the emphasis in genomics shifts from identifying and sequencing genes to the problem of determining what their products do. Leaving aside the formidable technical challenges posed by that problem, there remains the prospect that the job, as commonly considered, is impossible: because the term 'function' means very different things to different people, and a given gene product might have almost as many 'functions' as there are scientists studying it. There is its biochemical function: the chemical or physical process it carries out when isolated from the cell and studied in vitro. There is its cellular function - signal transduction protein, translation inhibitor, transcription factor, and so on - which may depend on its location in the cell, what other molecules it is bound to, when in the cell cycle it is expressed, and so on. Then there is its larger biological function, which is most often defined by the pheno-type that is observed when it is deleted or mutated: growth control, or immune regulation, or involvement in morpho-genesis, to name but a few possibilities. The layers are almost infinite, especially for genes in metazoan organisms.Consider actin. Its biochemical function is to bind ATP and hydrolyse it, but it is not very good at that on its own. The ATPase activity can be modulated by the binding of other molecules - a common phenomenon in biochemistry. One could also say that the 'real' function of actin is to self-polymerize, forming filaments. This brings us closer to the cellular roles of actin, but these are legion: essential component of the cytoskeleton, 'railroad track' along which vesicles and other cellular constituents run, anchor for myosin in muscle contraction, target for the mushroom toxin phalloidin, rigidifier of microvilli, backbone of the acrosome, inhibitor of DNase I, and many more. When can we say we know what the 'function' of the actin gene is?Clearly any attempt to understand functio
The Dark Side of Creativity  [PDF]
Lanlan Liu, Maolin Ye
Open Journal of Social Sciences (JSS) , 2015, DOI: 10.4236/jss.2015.39026
Abstract: Creativity has been regarded as a positive force to promote the development of individuals, organizations and society. However, creativity also has a hidden dark side. In recent years, re-searchers have proposed the concept of the dark side of creativity and vicious creativity, and the concept focuses on the relationship between creativity and dishonesty. The article combed the researchers on the study of the relationship between creativity and dishonest behavior, creativity by improving individual defending their actions to increase the ability of the dishonest behavior of the individual in a dilemma situation.
The Dark Side of Conscientiousness  [PDF]
Adrian Furnham
Psychology (PSYCH) , 2017, DOI: 10.4236/psych.2017.811122
Abstract: This paper reports on two studies, each with large adult populations, which look at Dark-Side correlates (subclinical Personality Disorders) of two different measures of Trait Conscientiousness. In the first study, 5300 British adults completed the Prudence scale of the Hogan Personality Inventory (HPI) as well as the Hogan Development Survey (HDS), which measures Dark-Side traits. Correlation and regression results confirmed many of the associations between the seven facets of the Prudence scale and the Dark Side traits. Results showed that people who score high on Excitable, Mischievous and Imaginative reported low scores, while those who scored high on Diligent reported high scores on Prudence and its facets. In the second study, 6700 British adults completed the NEO-PI-R Conscientiousness Scale with six facet scores as well as the HDS. Regressions showed a similar pattern: people scoring high on Bold and Diligent, and low on Excitable and Cautious reported higher Conscientiousness. Similarities and differences in the findings for the two studies are considered. Paradoxically Conscientiousness is negatively associated with those Dark Side traits that are correlated with leadership emergence. Limitations of these studies are discussed.
Simulations: the dark side  [PDF]
Daan Frenkel
Physics , 2012,
Abstract: This paper discusses the Monte Carlo and Molecular Dynamics methods. Both methods are, in principle, simple. However, simple does not mean risk-free. In the literature, many of the pitfalls in the field are mentioned, but usually as a footnote - and these footnotes are scattered over many papers. The present paper focuses on the `dark side' of simulation: it is one big footnote. I should stress that `dark', in this context, has no negative moral implication. It just means: under-exposed.
The Bright Side of Dark Matter  [PDF]
A. Edery
Physics , 1999, DOI: 10.1103/PhysRevLett.83.3990
Abstract: We show that it is not possible in the absence of dark matter to construct a four-dimensional metric that explains galactic observations. In particular, by working with an effective potential it is shown that a metric which is constructed to fit flat rotation curves in spiral galaxies leads to the wrong sign for the bending of light i.e. repulsion instead of attraction. Hence, without dark matter the motion of particles on galactic scales cannot be explained in terms of geodesic motion on a four- dimensional metric. This reveals a new bright side to dark matter: it is indispensable if we wish to retain the cherished equivalence principle.
On the colour of the dark side of the Moon  [PDF]
Peter Thejll,Chris Flynn,Hans Gleisner,Torben Andersen,Ana Ulla,Mette Owner-Petersen,Ahmad Darudi,Henriette Schwarz
Physics , 2014, DOI: 10.1051/0004-6361/201322776
Abstract: Aims. 'Earthshine' is the dim light seen on the otherwise dark side of the Moon, particularly when it is close to new. 'Earthlight', or reflected sunlight from the Earth, is the source of Earthshine. Using B and V band CCD images of both the dark and bright side of the Moon, we aim to estimate the Johnson photometry B-V colour of the Earthshine for the first time since the late 1960s. From these measurements we are also able to quantify the colour of Earthlight. Methods. We present images of the Moon taken with a small refractor in Hawaii, in B and V bands and taken under favourable conditions so that scattered light in both bands almost completely cancels, yielding a map of the surface in B-V colour. Co-addition of 100 such images taken in rapid succession substantially improves the signal to noise ratio, and several sources of photometric bias are eliminated by use of relative methods. Results. The earthlit dark side of the Moon is observed to be 0.150 +/- 0.005 mag bluer in B-V than the sunlit bright side, in good agreement with the only known previous measurement of this quantity from 1967. Arguing on the basis of the change in B - V for sunlight reflected once o? the Moon, we derive a colour for earthlight of B-V = 0.44+/-0.02 mag (without applying a small, uncertain, phase-dependent reddening correction). The absence of a colour-gradient in the B-V image implies that the scattering properties of the atmosphere+optical system are almost exactly matched in the two wavelength bands, the consequences of which are discussed.
The Dark Side of the Universe  [PDF]
Joseph Silk
Physics , 2001, DOI: 10.1142/S0217751X02013101
Abstract: Most of the matter in the universe is invisible. I review the status of dark matter and describe how both the theory of galaxy formation and novel types of experimental searches are revitalizing attempts to find non-baryonic dark matter.
On The Dark Side of Quasar Evolution  [PDF]
Kristen Menou,Zoltan Haiman
Physics , 2004, DOI: 10.1086/423951
Abstract: Recent improved determinations of the mass density rho_BH of supermassive black holes (SMBHs) in the local universe have allowed accurate comparisons of rho_BH with the amount of light received from past quasar activity. These comparisons support the notion that local SMBHs are ``dead quasars'' and yield a value epsilon >~ 0.1 for the average radiative efficiency of cosmic SMBH accretion. BH coalescences may represent an important component of the quasar mass assembly and yet not produce any observable electromagnetic signature. Therefore, ignoring gravitational wave (GW) emission during such coalescences, which reduces the amount of mass locked into remnant BHs, results in an overestimate of epsilon. Here, we put constraints on the magnitude of this bias. We calculate the cumulative mass loss to GWs experienced by a representative population of BHs during repeated cosmological mergers, using loss prescriptions based on detailed general relativistic calculations. Despite the possibly large number of mergers in the assembly history of each individual SMBH, we find that near--equal mass mergers are rare, and therefore the cumulative loss is likely to be modest, amounting at most to an increase by 20 percent of the inferred epsilon value. Thus, recent estimates of epsilon >~ 0.1 appear robust. The space interferometer LISA should provide empirical constraints on the dark side of quasar evolution, by measuring the masses and rates of coalescence of massive BHs to cosmological distances.
The Dark Side of Neutron Stars  [PDF]
Chris Kouvaris
Physics , 2013,
Abstract: We review severe constraints on asymmetric bosonic dark matter based on observations of old neutron stars. Under certain conditions, dark matter particles in the form of asymmetric bosonic WIMPs can be effectively trapped onto nearby neutron stars, where they can rapidly thermalize and concentrate in the core of the star. If some conditions are met, the WIMP population can collapse gravitationally and form a black hole that can eventually destroy the star. Based on the existence of old nearby neutron stars, we can exclude certain classes of dark matter candidates.
The Dark Side of Neutron Stars  [PDF]
Chris Kouvaris
Advances in High Energy Physics , 2013, DOI: 10.1155/2013/856196
Abstract: We review severe constraints on asymmetric bosonic dark matter based on observations of old neutron stars. Under certain conditions, dark matter particles in the form of asymmetric bosonic WIMPs can be effectively trapped onto nearby neutron stars, where they can rapidly thermalize and concentrate in the core of the star. If some conditions are met, the WIMP population can collapse gravitationally and form a black hole that can eventually destroy the star. Based on the existence of old nearby neutron stars, we can exclude certain classes of dark matter candidates. 1. Introduction Compact stars such as neutron stars and white dwarfs can lead in general to two types of constraints regarding dark matter candidates. The first one has to do with annihilating dark matter that changes the thermal evolution of the star. Annihilation of Weakly Interacting Massive Particles (WIMPs) that are trapped inside compact stars can lead to the production of significant amount of heat that can change the temperature of old stars [1–4]. Such a phenomenon can be in principle contrasted to observations. The second type of constraints is related to asymmetric dark matter [5–12]. Asymmetric dark matter is an attractive alternative to thermally produced dark matter especially due to the intriguing possibility of relating its asymmetry to the baryonic one. For recent reviews see [13, 14]. Due to the asymmetry, WIMP annihilation is not significant in this case. If a certain amount of WIMPs is trapped inside the star, the WIMPs can quite rapidly thermalize and concentrate within a tiny radius in the core of the star. If the WIMP population grows significantly, WIMPs might become self-gravitating and they might collapse forming a mini black hole. Under certain conditions, the black hole might consume the rest of the star, thus leading to the ultimate destruction of the star. However, very old (older than a few billion years) nearby neutron stars have been well observed and studied. The simple presence of such verified old stars leads to the conclusion that no black hole has consumed the star and as we will argue, this can lead to very severe constraints on the properties of certain types of asymmetric dark matter. We should also mention that additional constraints on asymmetric dark matter can be imposed on different ways (e.g., from asteroseismology [15–17], from effects on the transport properties of the neutron stars [18], and/or from hybrid dark matter rich compact stars [19, 20]). One can easily figure out that fermionic WIMPs, due to the fact that they have to overcome Fermi
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