There is no robust evidence that allelic variations of rs16969968 or rs1051730 are associated with smoking cessation after NRT. Original submitted 26 November 2014; Revision submitted 9 March 2015.

The amplicon size analysis proved to be the most accurate method using the haplotype as a possible genetic marker for future testing. Although the results were not significant, further molecular analyses of the DBH gene and other candidate genes can clarify the utility of the molecular phase in psychiatric genetics and personalized medicine.

In a recent Letter 1 Mahler et al. employed the minimum entropy production principle (MEPP) to derive the steady-state density and temperature spatial profiles of an electron-hole plasma (EHP) generated by laser irradiation of silicon at low (<50 K) temperatures. Since the EHP is generated at the surface, the steady-state profiles are established and maintained primarily through diffusion processes within the plasma. Their calculations show an EHP temperature which rises monotonically away from the sample surface and, for a high enough laser intensity, an EHP density which has its maximum value in the bulk. This behavior, which is used to explain luminescence experiments in silicon and other semiconductors, is claimed to represent "perhaps the most universal collective excitation effect observed in these materials. ,, We believe that the distributions of Mahler et al. are the result of an improper application of the MEPP. In this Comment we wish to point out the source of the inconsistency.Briefly, Mahler et al. start with the linear phenomenological transport equations [their Eq. (1)], applicable to carriers whose only interaction with the lattice is assumed to be through momentum transfer. From the continuity equation, if steady state and infinite carrier lifetime are assumed, the particle current, j m9 is determined by the generation rate at the surface and is a constant in the bulk. Mahler et al. then claim that since the EHP temperature is not constrained externally, MEPP implies that j Q = 0. This condition leads to the interesting distributions reported and is the one which is inconsistent with the physics of the situation. The j q of Eq. (1) enters the entropy production expression 2 ' 3 conjugate to the VT" 1 thermodynamic force. Since the EHP does not internally conserve momentum in collisions with the lattice, j Q in the situation here represents the total energy flow 3 in the EHP (heat conduction associated with VT" 1 as well as heat of transport associated with j m 2 ) and not the "substantial current density of internal energy" as interpreted by Mahler et al.Since the laser supplies energy to the EHP in the generation region, continuity and steady-state considerations imply that j q is a nonzero constant in the bulk. This reasonably assumes that negligible heat is lost out the sample surface. We note that the inconsistency of the analysis of Mahler et al. occurs since, in fact, there is no clear separation of the external constraints on the particle and thermal thermodynamic forces. Indeed, the stationary particle and heat currents should be carefully derived with use of variational principles to minimize the entropy production with respect to a combination of externally constrained forces conjugate to the particle and energy fluxes. A realistic expression for the entropy production should also include the nanosecond lifetime effects 4 and the picosecond or perhaps nanosecond 5 time constant associated with EHP-lattice energy coupling over most of the temperature range of interest. When the above ...

X-chromosome inactivation (XCI) epigenetically silences one X chromosome in every cell in female mammals. Although the majority of X-linked genes are silenced, in humans 20% or more are able to escape inactivation and continue to be expressed. Such escape genes are important contributors to sex differences in gene expression, and may impact the phenotypes of X aneuploidies; yet the mechanisms regulating escape from XCI are not understood. We have performed an enrichment analysis of transcription factor binding on the X chromosome, providing new evidence for enriched factors at the transcription start sites of escape genes. The top escape-enriched transcription factors were detected at the RPS4X promoter, a well-described human escape gene previously demonstrated to escape from XCI in a transgenic mouse model. Using a cell line model system that allows for targeted integration and inactivation of transgenes on the mouse X chromosome, we further assessed combinations of RPS4X promoter and genic elements for their ability to drive escape from XCI. We identified a small transgenic construct of only 6 kb capable of robust escape from XCI, establishing that gene-proximal elements are sufficient to permit escape, and highlighting the additive effect of multiple elements that work together in a context-specific fashion.