Jupiter: its infrared spectrum from 16 to 40 micrometers

Spectral measurements of the thermal radiation from Jupiter in the band from 16 to 40 micrometers are analyzed under the assumption that pressure-broadened molecular hydrogen transitions are responsible for the bulk of the infrared opacity over most of this spectral interval. Both the vertical pressure-temperature profile and the molecular hydrogen mixing ratio are determined. The derived value ofthe molecular hydrogen mixing ratio, 0.89 +/- 0.11, is consistent with the solar value of 0.86.     

Superpressure balloon flights in the tropical stratosphere

Seven balloons were launched successfully from Ascension Island in January 1969. The balloons, flown at altitudes of 20 and 24 kilometers, will make possible a detailed analysis of the stratospheric circulation near the equator and will hopefully lead to an understanding of the quasi-biennial stratospheric oscillation in the tropics.     

美国农民纳税分析

税收是美国政府调节经济和社会分配的重要杠杆，农民缴纳的税收是美国政府财政收入的重要组成部分。近年来，在扶持农民、补贴农业的总体政策框架下，美国政府不断改革农业税制，缩减农民纳税范围，减轻农民税负，以增加农民的实际收入。一、美国农民纳税水平美国是个高税赋的国家，政府通过税收集中了约占GDP１／３以上的国民收入，以确保政府调节经济与社会分配功能的正常发挥。表１总结了近１０年来美国联邦与州以及地方政府财政收入情况。美国的税收资料是按照税目分类统计的，单独划分农民纳税资料难以查到。１９９８年，美国农业部…     

Discovery of a viral NLR homolog that inhibits the inflammasome

The NLR (nucleotide binding and oligomerization, leucine-rich repeat) family of proteins senses microbial infections and activates the inflammasome, a multiprotein complex that promotes microbial clearance. Kaposi's sarcoma-associated herpesvirus (KSHV) is linked to several human malignancies. We found that KSHV Orf63 is a viral homolog of human NLRP1. Orf63 blocked NLRP1-dependent innate immune responses, including caspase-1 activation and processing of interleukins IL-1β and IL-18. KSHV Orf63 interacted with NLRP1, NLRP3, and NOD2. Inhibition of Orf63 expression resulted in increased expression of IL-1β during the KSHV life cycle. Furthermore, inhibition of NLRP1 was necessary for efficient reactivation and generation of progeny virus. The viral homolog subverts the function of cellular NLRs, which suggests that modulation of NLR-mediated innate immunity is important for the lifelong persistence of herpesviruses.     

Phototropic Leaflet Reorientation in Alfalfa Germplasm Selected for Leaf Color and Size

Solar tracking has been described in several agronomic and wild species, yet variation within a given species has not been reported. To address that issue, photoperiod leaflet reorientation in response to vectorial light was measured in three alfalfa ( Medicago sativa L.) germplasm pools selected from the cultivar Ladak 65. Dark-leaf germplasm responded to all photosynthetic photon flux densities (PPFD) (100 to 700 μmol/m²/s) with no detectable lag period. Following a 24-h dark treatment only high PPFD (600 to 700μmol/m²/s) elicited reorientation. Pale-leaf germplasm responded to intermediate (300 to 400 μmol/m²/s) and high PPFD in a similar manner; however, the low (100-125μmol/m²/s) PPFD treatment had little effect on reorientation. The 24-h dark treatment decreased reorientation at all PPFD. Small-leaf germplasm responded equally to all PPFD and was not affected by the 24-h dark treatment. The results suggest that available energy levels may influence the reorientation response. Carbonyl cyanide m -chlorophenylhydrazone, an inhibitor of photophosphorylation, and 3-(3,4-dichlorophenyl)-1,1-dimethylurea, an inhibitor of non-cyclic photosynthetic electron transport, reduced reorientation only in the pale-leaf type. These results suggest that stored energy reserves were adequate to maintain leaflet reorientation in the absence of photosynthesis in all but the pale-leaf germplasm. In that germplasm photosynthetically generated energy may be required to support reorientation.