What is a Gene? A Two Sided View

The need to account for all currently available experimental observations concerning the gene nature, has reshaped the concept of gene turning it from the essentially mechanistic unit, predominant during the '70s, into a quite abstract open and generalized entity, whose contour appears less defined as compared to the past. Here we propose the essence of the gene to be considered double faced. In this respect genotypic and phenotypic entities of a gene would coexist and mix reciprocally. This harmonizes present knowledge with current definitions and predisposes for remodelling of our thinking as a consequence of future discoveries. A two sided view of the gene also allows to combine the genetic and epigenetic aspects in a unique solution, being structural and functional at the same time and simultaneously able to include the different levels in an overlapping unicum

What is a public sector pension worth?

We measure accruals in defined benefit (DB) pension plans for public and private sector workers in Britain, using typical differences in scheme rules and sector-specific lifetime age-earnings profiles by sex and educational group. We show not just that coverage by DB pension plans is greater in the public sector, but that median pension accruals as a % of salary are almost 5% higher among DB-covered public sector workers than covered private sector workers. This is largely driven by earlier normal pension (retirement) ages. For workers of different ages in the two sectors, marginal accruals also vary as a result of differences in earnings profiles across the sectors. The differences in earnings profiles across sectors should induce caution in using calculated coefficients on wages from cross sections of data in order to estimate sectoral wage effects

What is the Accretion Rate in Sgr A*?

The radio source Sgr A* at the center of our Galaxy is believed to be a 2.6 x 10^6 solar mass black hole which accretes gas from the winds of nearby stars. We show that limits on the X-ray and infrared emission from the Galactic Center provide an upper limit of ~ 8 x 10^{-5} solar masses per year on the mass accretion rate in Sgr A*. The advection-dominated accretion flow (ADAF) model favors a rate < 10^{-5} solar masses per year. In comparison, the Bondi accretion rate onto Sgr A*, estimated using the observed spatial distribution of mass losing stars and assuming non-interacting stellar winds, is ~ 3 x 10^{-5} solar masses per year. There is thus rough agreement between the Bondi, the ADAF, and the X-ray inferred accretion rates for Sgr A*. We discuss uncertainties in these estimates, emphasizing the importance of upcoming observations by the Chandra X-ray observatory (CXO) for tightening the X-ray derived limits.Comment: to appear in ApJ Letter

What is a public sector pension worth?

We measure accruals in defined benefit (DB) pension plans for public and private sector workers in Britain, using typical differences in scheme rules and sector-specific lifetime age-earnings profiles by sex and educational group. We show not just that coverage by DB pension plans is greater in the public sector, but that median pension accruals as a % of salary are almost 5% higher among DB-covered public sector workers than covered private sector workers. This is largely driven by earlier normal pension (retirement) ages. For workers of different ages in the two sectors, marginal accruals also vary as a result of differences in earnings profiles across the sectors. The differences in earnings profiles across sectors should induce caution in using calculated coefficients on wages from cross sections of data in order to estimate sectoral wage effects.

What is a robot companion - friend, assistant or butler?

The study presented in this paper explored people's perceptions and attitudes towards the idea of a future robot companion for the home. A human-centred approach was adopted using questionnaires and human-robot interaction trials to derive data from 28 adults. Results indicated that a large proportion of participants were in favour of a robot companion and saw the potential role as being an assistant, machine or servant. Few wanted a robot companion to be a friend. Household tasks were preferred to child/animal care tasks. Humanlike communication was desirable for a robot companion, whereas humanlike behaviour and appearance were less essential. Results are discussed in relation to future research directions for the development of robot companions

What is the gravity dual of a chiral primary?

In the AdS/CFT correspondence a chiral primary is described by a supergravity solution with mass equaling angular momentum. For AdS_3 X S^3 we are led to consider three special families of metrics with this property: metrics with conical defects, Aichelburg-Sexl type metrics generated by rotating particles, and metrics generated by giant gravitons. We find that the first two of these are special cases of the complete family of chiral primary metrics which can be written down using the general solution in hep-th/0109154, but they correspond to two extreme limits - the conical defect metrics map to CFT states generated by twist operators that are all identical, while the Aichelburg-Sexl metrics yield a wide dispersion in the orders of these twists. The giant graviton solutions in contrast do not represent configurations of the D1-D5 bound state; they correspond to fragmenting this system into two or more pieces. We look at the large distance behavior of the supergravity fields and observe that the excitation of these fields is linked to the existence of dispersion in the orders and spins of the twist operators creating the chiral primary in the CFT.Comment: 33 pages, Latex, 3 figure

What is the Mass of a Gap-Opening Planet?

High contrast imaging instruments such as GPI and SPHERE are discovering gap structures in protoplanetary disks at an ever faster pace. Some of these gaps may be opened by planets forming in the disks. In order to constrain planet formation models using disk observations, it is crucial to find a robust way to quantitatively back out the properties of the gap-opening planets, in particular their masses, from the observed gap properties, such as their depths and widths. Combing 2D and 3D hydrodynamics simulations with 3D radiative transfer simulations, we investigate the morphology of planet-opened gaps in near-infrared scattered light images. Quantitatively, we obtain correlations that directly link intrinsic gap depths and widths in the gas surface density to observed depths and widths in images of disks at modest inclinations under finite angular resolution. Subsequently, the properties of the surface density gaps enable us to derive the disk scale height at the location of the gap $h$, and to constrain the quantity $M_{\rm p}^2/\alpha$, where $M_{\rm p}$ is the mass of the gap-opening planet and $\alpha$ characterizes the viscosity in the gap. As examples, we examine the gaps recently imaged by VLT/SPHERE, Gemini/GPI, and Subaru/HiCIAO in HD 97048, TW Hya, HD 169142, LkCa 15, and RX J1615.3-3255. Scale heights of the disks and possible masses of the gap-opening planets are derived assuming each gap is opened by a single planet. Assuming $\alpha=10^{-3}$, the derived planet mass in all cases are roughly between 0.1-1 $M_{\rm J}$.Comment: 40 pages (single column), 14 figures, 2 tables, ApJ publishe

Ending Child Marriage in a Generation: What Research is Needed?

In recent years, the obstacles that child marriage poses to development and to the achievement of the Millennium Development Goals have been widely recognized. Varied responses to the problem have been devised. The number of programs testing different approaches to ending child marriage has grown, and many have been evaluated. We are starting to get a sense of what works and the general areas in which investing in research could make a difference.The purpose of this paper is to identify gaps in the research on child marriage in which additional investment could catalyze change. Much remains to understand about child marriage and how to influence it. By mapping out current knowledge of child marriage and the programs designed to address it, and by highlighting questions to which we do not yet know the answers, the paper is intended to generate discussion in the field and clarify what we need to know to bring an end to this deeply harmful practice.The paper also moves us closer to the development of a shared theory of change for this field: given that many organizations are now working in this area, how can their programs and related research be understood -- aligned -- in such a way that their work feeds into a single theory of change?The research gaps on their own should not drive investments in child marriage. A worthy research mandate must also be driven by programmatic and advocacy needs. The recommended areas for research are not meant to provide a definitive menu, but rather to describe the general contours of what we know and what we need to understand better

Q&amp;A: Cellular near death experiences-what is anastasis?

Apoptosis is a form of programmed cell death that is carried out by proteolytic enzymes called caspases. Executioner caspase activity causes cells to shrink, bleb, and disintegrate into apoptotic bodies and has been considered a point of no return for apoptotic cells. However, relatively recent work has shown that cells can survive transient apoptotic stimuli, even after executioner caspase activation. This process is called anastasis. In this Q&amp;A, we answer common questions that arise regarding anastasis, including how it is defined, the origin of the name, the potential physiological consequences, molecular mechanisms, and open questions for this new field of study