Noble Gas Clusters and Nanoplasmas in High Harmonic Generation

We report a study of high harmonic generation from noble gas clusters of xenon atoms in a gas jet. Harmonic spectra were investigated as a function of backing pressure, showing spectral shifts due to the nanoplasma electrons in the clusters. At certain value of laser intensity this process may oppose the effect of the well-known ionization-induced blueshift. In addition, these cluster-induced harmonic redshifts may give the possibility to estimate cluster density and cluster size in the laser-gas jet interaction range.Comment: 5 pages, 4 figure

RG Flows and Stability in Defect Field Theories

We investigate defects in scalar field theories in four and six dimensions in a double-scaling (semiclassical) limit, where bulk loops are suppressed and quantum effects come from the defect coupling. We compute $\beta$-functions up to four loops and find that fixed points satisfy dimensional disentanglement -- i.e. their dependence on the space dimension is factorized from the coupling dependence -- and discuss some physical implications. We also give an alternative derivation of the $\beta$ functions by computing systematic logarithmic corrections to the Coulomb potential. In this natural scheme, $\beta$ functions turn out to be a gradient of a `Hamiltonian' function ${\cal H}$. We also obtain closed formulas for the dimension of scalar operators and show that instabilities do not occur for potentials bounded from below. The same formulas are reproduced using Rigid Holography.Comment: 35 pages, 1 figure; v2: added reference

Defects, Rigid Holography and CC-theorems

We consider a general scalar QFT with a linear defect in $D=4-\epsilon$ and a surface defect in $D=6-\epsilon$. Using holography and the Hamilton-Jacobi formalism, we show that the $\beta$ functions controlling the defect RG flow are the gradient of the entropy function. In the case of conformal field theories, this allows the proof that the relevant $C$-functions decrease monotonically along the RG flow. We provide evidence that this property also holds in the full quantum theory for general scalar field theories. An obstruction to the gradient property seems to appear at two loop order when fermions are added.Comment: 6 pages, no figures; v2: published versio

Modular detergents tailor the purification and structural analysis of membrane proteins including G-protein coupled receptors

Detergents enable the purification of membrane proteins and are indispensable reagents instructural biology. Even though a large variety of detergents have been developed in the lastcentury, the challenge remains to identify guidelines that allowfine-tuning of detergents forindividual applications in membrane protein research. Addressing this challenge, here weintroduce the family of oligoglycerol detergents (OGDs). Native mass spectrometry (MS)reveals that the modular OGD architecture offers the ability to control protein purificationand to preserve interactions with native membrane lipids during purification. In addition to abroad range of bacterial membrane proteins, OGDs also enable the purification and analysisof a functional G-protein coupled receptor (GPCR). Moreover, given the modular design ofthese detergents, we anticipatefine-tuning of their properties for specific applications instructural biology. Seen from a broader perspective, this represents a significant advance forthe investigation of membrane proteins and their interactions with lipids

CD200 is up-regulated in R6/1 transgenic mouse model of Huntington's disease

In Huntington's disease (HD), striatal medium spiny neurons (MSNs) are particularly sensitive to the presence of a CAG repeat in the huntingtin (HTT) gene. However, there are many evidences that cells from the peripheral immune system and central nervous system (CNS) immune cells, namely microglia, play an important role in the etiology and the progression of HD. However, it remains unclear whether MSNs neurodegeneration is mediated by a non-cell autonomous mechanism. The homeostasis in the healthy CNS is maintained by several mechanisms of interaction between all brain cells. Neurons can control microglia activation through several inhibitory mechanisms, such as the CD200-CD200R1 interaction. Due to the complete lack of knowledge about the CD200-CD200R1 system in HD, we determined the temporal patterns of CD200 and CD200R1 expression in the neocortex, hippocampus and striatum in the HD mouse models R6/1 and HdhQ111/7 from pre-symptomatic to manifest stages. In order to explore any alteration in the peripheral immune system, we also studied the levels of expression of CD200 and CD200R1 in whole blood. Although CD200R1 expression was not altered, we observed and increase in CD200 gene expression and protein levels in the brain parenchyma of all the regions we examined, along with HD pathogenesis in R6/1 mice. Interestingly, the expression of CD200 mRNA was also up-regulated in blood following a similar temporal pattern. These results suggest that canonical neuronal-microglial communication through CD200-CD200R1 interaction is not compromised, and CD200 up-regulation in R6/1 brain parenchyma could represent a neurotrophic signal to sustain or extend neuronal function in the latest stages of HD as pro-survival mechanism

DAMPAK KEBERADAAN LIPPO PLAZA TERHADAP KINERJA LALU LINTAS DI RUAS JALAN VETERAN KOTA KUPANG

This research aimed at measuring level of performance in the form of service capacity at Veteran St., as it was affected by the existence of Lipo Plaza. The affect of the business center on service capacity of some sections of roads would be expressed in the comparisons of traffic volume, traffic capacity and degree of saturation (DS) before its existence, to the same after it had existed. Result of analysis in this research showed that there was a change in traffic volume, either increasing or decreasing. Increase of traffic volume occurred at segment of Veteran St., Patung Kirab area, Nostalgia Park area, Ina Bo’I, W.R. Monginsidi St., and Perintis Kemerdekaan St., each in value of 81.5 pmu/h, 35.97 pmu/h, 17.41 pmu/h, 8.83 pmu/h and 38.94 pmu/h respectively; whereas decrease of the same occurred at road segment to the back of Ruko Oebobo, in the value of 1.37 pmu/h. Service level of Veteran St. was proved to be still adequate despite the dercrease of DS at Veteran St., Patung Kirab area, Nostalgia Park area, Ina Boi, W.R. Monginsidi St, and Perintis Kemerdekaan St., each in the value of 4.05%, 2.07%, 0.75% 0.34% and 2.86 respectively. There was still location with decreasing DS that is the segment of road to the back of Ruko Oebobo, namely 0.13%. Observation also showed that there exists potency for traffic jam, therefore measures for prevention was recommended, such as installing warning traffic-light at intersection of Veteran St., Nostalia Park and Ruko Oebobo, and temporary road separator at Veteran St. These could as well prevent traffic crash at conflict points

Reduced fractalkine levels lead to striatal synaptic plasticity deficits in Huntington's disease

Huntington's disease (HD) is an inherited neurodegenerative disorder in which the striatum is the most affected brain region. Although a chronic inflammatory microglial reaction that amplifies disease progression has been described in HD patients, some murine models develop symptoms without inflammatory microglial activation. Thus, dysfunction of non-inflammatory microglial activity could also contribute to the early HD pathological process. Here, we show the involvement of microglia and particularly fractalkine signaling in the striatal synaptic dysfunction of R6/1 mice. We found reduced fractalkine gene expression and protein concentration in R6/1 striata from 8 to 20 weeks of age. Consistently, we also observed a down-regulation of fractalkine levels in the putamen of HD patients and in HD patient hiPSC-derived neurons. Automated cell morphology analysis showed a non-inflammatory ramified microglia in the striatum of R6/1 mice. However, we found increased PSD-95-positive puncta inside microglia, indicative of synaptic pruning, before HD motor symptoms start to manifest. Indeed, microglia appeared to be essential for striatal synaptic function, as the inhibition of microglial activity with minocycline impaired the induction of corticostriatal long-term depression (LTD) in wild-type mice. Notably, fractalkine administration restored impaired corticostriatal LTD in R6/1 mice. Our results unveil a role for fractalkine-dependent neuron-microglia interactions in the early striatal synaptic dysfunction characteristic of HD