Compensatory weight gain due to dopaminergic hypofunction: new evidence and own incidental observations

There is increasing evidence for a role of dopamine in the development of obesity. More specifically, dopaminergic hypofunction might lead to (over)compensatory food intake. Overeating and resulting weight gain may be induced by genetic predisposition for lower dopaminergic activity, but might also be a behavioral mechanism of compensating for decreased dopamine signaling after dopaminergic overstimulation, for example after smoking cessation or overconsumption of high palatable food. This hypothesis is in line with our incidental finding of increased weight gain after discontinuation of pharmaceutical dopaminergic overstimulation in rats. These findings support the crucial role of dopaminergic signaling for eating behaviors and offer an explanation for weight-gain after cessation of activities associated with high dopaminergic signaling. They further support the possibility that dopaminergic medication could be used to moderate food intake

Compensatory weight gain due to dopaminergic hypofunction: new evidence and own incidental observations

There is increasing evidence for a role of dopamine in the development of obesity. More specifically, dopaminergic hypofunction might lead to (over)compensatory food intake. Overeating and resulting weight gain may be induced by genetic predisposition for lower dopaminergic activity, but might also be a behavioral mechanism of compensating for decreased dopamine signaling after dopaminergic overstimulation, for example after smoking cessation or overconsumption of high palatable food. This hypothesis is in line with our incidental finding of increased weight gain after discontinuation of pharmaceutical dopaminergic overstimulation in rats. These findings support the crucial role of dopaminergic signaling for eating behaviors and offer an explanation for weight-gain after cessation of activities associated with high dopaminergic signaling. They further support the possibility that dopaminergic medication could be used to moderate food intake

Highly Upregulated Lhx2 in the Foxn1−/−^{−/−} Nude Mouse Phenotype Reflects a Dysregulated and Expanded Epidermal Stem Cell Niche

Hair cycling is a prime example of stem cell dependent tissue regeneration and replenishment, and its regulatory mechanisms remain poorly understood. In the present study, we evaluated the effect of a blockage in terminal keratinocytic lineage differentiation in the Foxn1$^{−/−}$ nude phenotype on the epithelial progeny. Most notably we found a constitutive upregulation of LIM homeobox protein 2 (Lhx2), a marker gene of epithelial stem cellness indispensible for hair cycle progression. However, histological evidence along with an erratic, acyclic rise of otherwise suppressed CyclinD1 levels along with several key markers of keratinocyte lineage differentiation indicate a frustrated expansion of epithelial stem cell niches in skin. In addition, CD49f/CD34/CD200–based profiling demonstrated highly significant shifts in subpopulations of epithelial progeny. Intriguingly this appeared to include the expansion of Oct4+ stem cells in dermal fractions of skin isolates in the Foxn1 knock-out opposed to wild type. Overall our findings indicate that the Foxn1$^{−/−}$ phenotype has a strong impact on epithelial progeny and thus offers a promising model to study maintenance and regulation of stem cell niches within skin not feasible in other in vitro or in vivo models

KLT relations from the Einstein-Hilbert Lagrangian

The Kawai-Lewellen-Tye (KLT) relations derived from string theory tell us that perturbative gravity amplitudes are the "square" of the corresponding amplitudes in gauge theory. Starting from the light-cone Lagrangian for pure gravity we make these relations manifest off-shell, for three- and four-graviton vertices, at the level of the action.Comment: 9 page

Colloquium: Quantum interference of clusters and molecules

We review recent progress and future prospects of matter wave interferometry with complex organic molecules and inorganic clusters. Three variants of a near-field interference effect, based on diffraction by material nanostructures, at optical phase gratings, and at ionizing laser fields are considered. We discuss the theoretical concepts underlying these experiments and the experimental challenges. This includes optimizing interferometer designs as well as understanding the role of decoherence. The high sensitivity of matter wave interference experiments to external perturbations is demonstrated to be useful for accurately measuring internal properties of delocalized nanoparticles. We conclude by investigating the prospects for probing the quantum superposition principle in the limit of high particle mass and complexity.Comment: 19 pages, 13 figures; v2: corresponds to published versio

Collectively enhanced Ramsey readout by cavity sub- to superradiant transition

When an inverted ensemble of atoms is tightly packed on the scale of its emission wavelength or when the atoms are collectively strongly coupled to a single cavity mode, their dipoles will align and decay rapidly via a superradiant burst. However, a spread-out dipole phase distribution theory predicts a required minimum threshold of atomic excitation for superradiance to occur. Here we experimentally confirm this predicted threshold for superradiant emission on a narrow optical transition when exciting the atoms transversely and show how to take advantage of the resulting sub- to superradiant transition. A $\pi/2$-pulse places the atoms in a subradiant state, protected from collective cavity decay, which we exploit during the free evolution period in a corresponding Ramsey pulse sequence. The final excited state population is read out via superradiant emission from the inverted atomic ensemble after a second $\pi/2$-pulse, and with minimal heating this allows for multiple Ramsey sequences within one experimental cycle. Our scheme is a fundamentally new approach to atomic state readout characterized by its speed, simplicity, and high sensitivity. It demonstrates the potential of sensors using collective effects in cavity-coupled quantum emitters

On-shell recursion relations for all Born QCD amplitudes

We consider on-shell recursion relations for all Born QCD amplitudes. This includes amplitudes with several pairs of quarks and massive quarks. We give a detailed description on how to shift the external particles in spinor space and clarify the allowed helicities of the shifted legs. We proof that the corresponding meromorphic functions vanish at z --> infinity. As an application we obtain compact expressions for helicity amplitudes including a pair of massive quarks, one negative helicity gluon and an arbitrary number of positive helicity gluons.Comment: 30 pages, minor change

Tracheoesophageal Fistula Closure in a Pediatric Patient Using a Supraclavicular Artery Island Flap

Acquired tracheoesophageal fistulas can lead to large defects with fatal complications. Surgical management is challenging but necessary to prevent respiratory infections and poor weight gain. Therefore, a reliable and pliable flap like the pedicled supraclavicular artery island flap with its wide arc of rotation and robust vascularization is needed for reconstruction. We highlight the surgical technique and postoperative measures in managing a tracheoesophageal fistula due to button battery ingestion in a 9-month-old boy with the supraclavicular artery island flap. In summary, the supraclavicular artery island flap is a safe and successful tool for closure of large acquired tracheoesophageal fistulas in pediatric patients