Magnetic Field and Plasma Observations at Mars: Initial Results of the Mars Global Surveyor Mission

The magnetometer and electron reflectometer investigation (MAG/ER) on the Mars Global Surveyor spacecraft has obtained magnetic field and plasma observations throughout the near-Mars environment, from beyond the influence of Mars to just above the surface (at an altitude of approximately 100 kilometers). The solar wind interaction with Mars is in many ways similar to that at Venus and at an active comet, that is, primarily an ionospheric-atmospheric interaction. No significant planetary magnetic field of global scale has been detected to date (<2 x 10(21) Gauss-cubic centimeter), but here the discovery of multiple magnetic anomalies of small spatial scale in the crust of Mars is reported.     

Adverse reaction to procaine penicillin G in horses

Adverse reactions to intramuscular injections of procaine penicillin G are reported in 11 horses, five of which died. The clinical findings are presented and suggest central nervous involvement in most cases. Post mortem findings in one horse were consistent with anaphylaxis whereas in other cases the clinical findings, duration of treatment, speed of onset and subsequent completion of treatment supports diagnosis of an acute procaine toxicity syndrome.     

南疆灌区冬小麦/夏玉米改良模式增产潜力与机理分析

田间试验系统地比较了新冬20/沈玉2002不同套种模式（“522模式”与“952模式”）及“521模式”下保麦10号/蠡玉35、保麦10号/登海3672、新冬20/蠡玉35的产量、叶面积指数、光合势及干物质积累等性状的差异。结果表明,“522模式”新冬20/沈玉2002周年产量（17 838.2 kg·hm^-2）较“952模式”(16 550.9 kg·hm^-2)增产7.8%,其中,冬小麦增产18.4%。“521模式”保麦10号/蠡玉35、保麦10号/登海3672、新冬20/蠡玉35周年产量为19 905.0～20 751.0 kg·hm^-2,其中,冬小麦产量为9 740～10 275 kg·hm^-2、夏玉米产量为9 630～10 211.0 kg·hm^-2;冬小麦孕穗期和开花期叶面积指数分别为6.0、5.0左右,返青至成熟的总光合势290.2～324.3×10⁴·m²·d·hm^-2;夏玉米生育期111 d,大喇叭口期至吐丝后20 d的叶面积指数均保持在4左右,生育期间总光合势233.1～257.5×10⁴·m²·d·hm^-2,冬小麦和玉米总光合势为523.3～581.8×10⁴·m²·d·hm^-2;总干物质量38 569.1～40 487.0 kg·hm^-2;冬小麦产量的边际效应为85.7%～112.9%。“521模式”比“952模式”大幅度增产,是小麦行数和边行数及边际产量增大的结果,并将夏玉米播期提至麦收前15 d左右,延长玉米生育期（达110 d左右）,优化株行配置使玉米增产显著,实现全年超高产。“521模式”同时充分利用了冬小麦边际补偿效应和玉米时间补偿效应,较“952模式”易获得周年超高产。并对超高产栽培技术进行了讨论。     

Stratospheric Mean Ages and Transport Rates from Observations of Carbon Dioxide and Nitrous Oxide

Measurements of stratospheric carbon dioxide (CO2) and nitrous oxide (N2O) concentrations were analyzed to investigate stratospheric transport rates. Temporal variations in tropospheric CO2 were observed to propagate into the stratosphere, showing that tropospheric air enters the lower tropical stratosphere continuously, ascends, and is transported rapidly (in less than 1 month) to both hemispheres. The mean age A of stratospheric air determined from CO2 data is approximately 5 years in the mid-stratosphere. The mean age is mathematically equivalent to a conserved tracer analogous to exhaust from stratospheric aircraft. Comparison of values for A from models and observations indicates that current model simulations likely underestimate pollutant concentrations from proposed stratospheric aircraft by 25 to 100 percent.     

Preliminary Studies on Cryopreservation of Common Tench (Tinca tinca) Embryos (Work in Progress)

Vitrification could provide a promising tool for the cryopreservation of fish embryos. However, to achieve cryopreservation using vitrification, chilling sensitivity and cryoprotectants toxicity were determined using tench embryos at four developmental stages (11, 17, 23 and 29 h). Embryos treated with alcalase (2 ml/998 ml, 2 min at 22°C) were exposed to chilling with/without warming. Other embryos were exposed to methanol and glycerol at the concentration of 10% and 20% for periods of 20 min. At last, embryos were incubated at special incubator cages where hatching rates were counted. Regarding chilling sensitivity and exposure to chilling followed by warming, the hatching rates of embryos decreased significantly (p < 0.001) after exposure to 0°C at all developmental stages except the 29-h stage compared with the controls. The embryo stage most sensitive to chilling was 11-h stage. The 29-h stage exhibited the least sensitivity to low temperature while 17-h and 23-h stages were intermediate in their sensitivity to chilling. The toxicity of methanol increased significantly (p < 0.001) with developmental stage for 11, 17 and 23-h stages. The highest hatching rates of tench embryos were obtained with 29-h embryos using various concentrations of methanol. The hatching rates of tench embryos exposed to glycerol concentrations were approximately similar to those embryos exposed to methanol concentrations except for 11-h embryos that showed no hatching. Unfortunately, we could not obtain living embryos in any of the conditions examined after vitrification. In conclusion, it was quite difficult to vitrify the tench embryos during this study using various vitrifying solutions and the method reported by Chen & Tian (2005) and further studies are needed to achieve successful cryopreservation.     

Synthesis of self-pillared zeolite nanosheets by repetitive branching

Hierarchical zeolites are a class of microporous catalysts and adsorbents that also contain mesopores, which allow for fast transport of bulky molecules and thereby enable improved performance in petrochemical and biomass processing. We used repetitive branching during one-step hydrothermal crystal growth to synthesize a new hierarchical zeolite made of orthogonally connected microporous nanosheets. The nanosheets are 2 nanometers thick and contain a network of 0.5-nanometer micropores. The house-of-cards arrangement of the nanosheets creates a permanent network of 2- to 7-nanometer mesopores, which, along with the high external surface area and reduced micropore diffusion length, account for higher reaction rates for bulky molecules relative to those of other mesoporous and conventional MFI zeolites.