Sudakov effects and the dipole amplitude

In this study we incorporate the Sudakov form factor into the dipole factorization formula, where the hard scale of the former is provided by the photon virtuality $Q^2$. We obtain a general formula which we then apply to the well-known GBW and BGK saturation models. Parameters of the above Sudakov-improved models are successfully fitted to the $F_2$ data from HERA. We observe, in particular, that inclusion of the Sudakov factor on top of the GBW model improves description of data at large $Q^2$.Comment: 18 pages, 9 figures, 4 table

Effects of gluon kinematics and the Sudakov form factor on the dipole amplitude

We investigate effects of exact gluon kinematics on the parameters of the Golec-Biernat-W\"usthoff, and Bartels-Golec-Biernat-Kowalski saturation models. The resulting fits show some differences, particularly, in the normalization of the dipole cross section $\sigma_0$. The refitted models are used for the dijet production process in DIS to investigate effects of the Sudakov form factor at Electron Ion Collider energies.Comment: 19 pages, 8 figures; v2: references adde

チョウコウネツキン コウソ オ ソシ ト スル バイオ センサー ノ カイハツ : ポリアミン カンレン コウソ ノ キノウ カイセキ ト D-プロリン ダツスイソ コウソ キノウ デンキョク センサー ノ カイハツ

An amperometric enzyme sensor give us higher sensitivity and specificity for the substrate determination. In spite of advantages of enzyme sensor, many enzymes so far found have been too labile to use as biosensor elements in artificial circumstances for a longer period. Hyperthermophiles, which can grow above 90℃, have been known to produce much more stable enzymes under various artificial conditions. In this work, we carried out screening, biochemical characterization and improvement of production for hyperthermostable enzymes which are more useful as the elements in the biosensors. We focused on the polyamines as one of the substrates of biosensors. Polyamines have been known to play many important roles in cell proliferation, differentiation and transformation. The concentration of the polyamines together with their acetyl conjugates remarkably increases in the biological fluids and the affected tissues of cancer patients. Therefore, their polyamines are listed as tumor markers. Gas and ion chromatographies have been so far used for polyamine determination, but have some problems from the aspects of high sensitivity and easy operation. Thus, we here developed biosensors using hyperthermostable enzymes for polyamine determination. Such enzyme sensors are more useful for the simple and rapid determination of polyamines and application for clinical analysis and food analysis In addition, we tried the construction of biosensor using the hyperthermophilic enzyme, D-Proline dehydrogenase. As the results, we found the thermostable agmatinase and spermidine dehydrogenase in hyperthermophiles, Pyrococcus horikoshii and Sulfolobus tokodaii, respectively. We succeeded the construction of novel amperometric sensor for D-proline determination using D-Proline dehydrogenase derived from Pyrobaculum islandicum

Dust from Comet 209P/LINEAR during its 2014 Return: Parent Body of a New Meteor Shower, the May Camelopardalids

We report a new observation of the Jupiter-family comet 209P/LINEAR during its 2014 return. The comet is recognized as a dust source of a new meteor shower, the May Camelopardalids. 209P/LINEAR was apparently inactive at a heliocentric distance rh = 1.6 au and showed weak activity at rh < 1.4 au. We found an active region of <0.001% of the entire nuclear surface during the comet's dormant phase. An edge-on image suggests that particles up to 1 cm in size (with an uncertainty of factor 3-5) were ejected following a differential power-law size distribution with index q=-3.25+-0.10. We derived a mass loss rate of 2-10 kg/s during the active phase and a total mass of ~5x10^7 kg during the 2014 return. The ejection terminal velocity of millimeter- to centimeter-sized particles was 1-4 m/s, which is comparable to the escape velocity from the nucleus (1.4 m/s). These results imply that such large meteoric particles marginally escaped from the highly dormant comet nucleus via the gas drag force only within a few months of the perihelion passage.Comment: 18 pages, 4 figures, accepted on 2014 December 11 for publication in the Astrophysical Journal Letter

Astrocyte GluN2C NMDA receptors control basal synaptic strengths of hippocampal CA1 pyramidal neurons in the stratum radiatum

Experience-dependent plasticity is a key feature of brain synapses for which neuronal N-Methyl-D-Aspartate receptors (NMDARs) play a major role, from developmental circuit refinement to learning and memory. Astrocytes also express NMDARs, although their exact function has remained controversial. Here, we identify in mouse hippocampus, a circuit function for GluN2C NMDAR, a subtype highly expressed in astrocytes, in layer-specific tuning of synaptic strengths in CA1 pyramidal neurons. Interfering with astrocyte NMDAR or GluN2C NMDAR activity reduces the range of presynaptic strength distribution specifically in the stratum radiatum inputs without an appreciable change in the mean presynaptic strength. Mathematical modeling shows that narrowing of the width of presynaptic release probability distribution compromises the expression of long-term synaptic plasticity. Our findings suggest a novel feedback signaling system that uses astrocyte GluN2C NMDARs to adjust basal synaptic weight distribution of Schaffer collateral inputs, which in turn impacts computations performed by the CA1 pyramidal neuron