Contrasting effects on deep convective clouds by different types of aerosols

Convective clouds produce a significant proportion of the global precipitation and play an important role in the energy and water cycles. We quantify changes of the convective cloud ice mass-weighted altitude centroid (Z_(IWC)) as a function of aerosol optical thickness (AOT). Analyses are conducted in smoke, dust and polluted continental aerosol environments over South America, Central Africa and Southeast Asia, using the latest measurements from the CloudSat and CALIPSO satellites. We find aerosols can inhibit or invigorate convection, depending on aerosol type and concentration. On average, smoke tends to suppress convection and results in lower Z_(IWC) than clean clouds. Polluted continental aerosol tends to invigorate convection and promote higher Z_(IWC). The dust aerosol effects are regionally dependent and their signs differ from place to place. Moreover, we find that the aerosol inhibition or invigoration effects do not vary monotonically with AOT and the variations depend strongly on aerosol type. Our observational findings indicate that aerosol type is one of the key factors in determining the aerosol effects on convective clouds

Left gastric vein on the dorsal side of the splenic artery: a rare anatomic variant revealed during gastric surgery

PURPOSE: The left gastric vein (LGV) is an important blood vessel requiring dissection during gastric surgery. We describe a rare anatomic variant of the LGV. METHODS: The LGV drainage pattern was analyzed relative to intraoperative vascular anatomy in 2,111 patients with gastric cancer who underwent radical resection from May 2007 to September 2012. The incidence of the anatomic variant was determined, and the diameter and length of the LGV and the distances from the end of the LGV to the splenoportal confluence and the root of the left gastric artery (LGA) were measured by abdominal CT reconstruction. RESULTS: In 6 of the 2,111 (0.28 %) gastric cancer patients who underwent radical resection, the LGV descended on the left side of the gastropancreatic fold, ran across the dorsal side of the splenic artery and drained into the splenic vein. The mean diameter and length of the LGV were 5.10 ± 0.40 and 37.40 ± 5.19 mm, respectively, and the mean distance from the end of the LGV to the splenoportal confluence was 13.05 ± 0.86 mm. The closer the LGV and LGA were to the root, the greater the distance between them, with a mean 13.85 ± 1.02 mm between the end of the LGV and the root of the LGA. CONCLUSIONS: In this rare anatomic variant, the LGV descends along the gastropancreatic fold, runs across the dorsal side of the splenic artery and drains into the splenic vein. Knowledge of this rare anatomic variant will help avoid damage to the LGV during gastric surgery

Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction

Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson {\it et al.} [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fan-like electron outflow region including three well-collimated electron jets appears. The ($>1$ MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS

The CDEX-1 1 kg Point-Contact Germanium Detector for Low Mass Dark Matter Searches

The CDEX Collaboration has been established for direct detection of light dark matter particles, using ultra-low energy threshold p-type point-contact germanium detectors, in China JinPing underground Laboratory (CJPL). The first 1 kg point-contact germanium detector with a sub-keV energy threshold has been tested in a passive shielding system located in CJPL. The outputs from both the point-contact p+ electrode and the outside n+ electrode make it possible to scan the lower energy range of less than 1 keV and at the same time to detect the higher energy range up to 3 MeV. The outputs from both p+ and n+ electrode may also provide a more powerful method for signal discrimination for dark matter experiment. Some key parameters, including energy resolution, dead time, decay times of internal X-rays, and system stability, have been tested and measured. The results show that the 1 kg point-contact germanium detector, together with its shielding system and electronics, can run smoothly with good performances. This detector system will be deployed for dark matter search experiments.Comment: 6 pages, 8 figure