Composite infrared spectrometer (CIRS) on Cassini.

The Cassini spacecraft orbiting Saturn carries the composite infrared spectrometer (CIRS) designed to study thermal emission from Saturn and its rings and moons. CIRS, a Fourier transform spectrometer, is an indispensable part of the payload providing unique measurements and important synergies with the other instruments. It takes full advantage of Cassini's 13-year-long mission and surpasses the capabilities of previous spectrometers on Voyager 1 and 2. The instrument, consisting of two interferometers sharing a telescope and a scan mechanism, covers over a factor of 100 in wavelength in the mid and far infrared. It is used to study temperature, composition, structure, and dynamics of the atmospheres of Jupiter, Saturn, and Titan, the rings of Saturn, and surfaces of the icy moons. CIRS has returned a large volume of scientific results, the culmination of over 30 years of instrument development, operation, data calibration, and analysis. As Cassini and CIRS reach the end of their mission in 2017, we expect that archived spectra will be used by scientists for many years to come.

Composite infrared spectrometer (CIRS) on Cassini: publisher's note.

This publisher's note renumbers the reference list in Appl. Opt.56, 5274 (2017)APOPAI0003-693510.1364/AO.56.005274.

Heterorhabditis atacamensis n. sp. (Nematoda: Heterorhabditidae), a new entomopathogenic nematode from the Atacama Desert, Chile.

A new Heterorhabditis species of entomopathogenic nematode was isolated from soil of the Atacama Desert in Chile. The new species is characterized by morphometrics of the infective juvenile (IJ) with length (L) = 611 (578-666) µm, head to excretory pore length (EP) = 115 (101-126) µm, tail = 69 (62-79) µm long, (EP/tail) × 100 (E%) = 165 (149-182) and L/maximum body diameter (ratio a) = 28 (25-31). The male has spicules 45 (40-49) µm long, gubernaculum 20 (17-22) µm long and (spicule length/anal body diameter) × 100 (SW%) = 205 (179-249). The hermaphroditic adult has shallow cuticular folds immediately anterior and posterior to the vulva, a slight post-anal swelling and a finely rounded tail terminus. Morphologically, H. atacamensis n. sp. resembles H. safricana, H. marelatus, H. downesi and H. amazonensis, but can be distinguished by characters of adult and IJ stages. In particular, for adult males, H. atacamensis n. sp. differs from H. amazonensis by the number and orientation of the genital papillae and from H. downesi by the position of the excretory pore; by the shape of the female tail terminus from H. downesi and by the position of the IJ hemizonid from H. marelatus. Heterorhabditis atacamensis n. sp. is further characterized by internal transcribed spacer (ITS) and D2D3 rDNA sequences, the closest species, H. safricana, being separated by 13 bp across 730 bp of the ITS (incorporating ITS1 (partial sequence), 5.8S (complete sequence), ITS2 (complete sequence)) and 5 bp across 592 bp of the partial 28S (incorporating D2D3) sequence. The morphological and molecular data confirm that H. atacamensis n. sp. is a valid species.

HST spectroscopic observations of Jupiter after the collision of comet Shoemaker-Levy 9.

Ultraviolet spectra obtained with the Hubble Space Telescope identified at least 10 molecules and atoms in the perturbed stratosphere near the G impact site, most never before observed in Jupiter. The large mass of sulfur-containing material, more than 10(14) grams in S2 alone, indicates that many of the sulfur-containing molecules S2, CS2, CS, H2S, and S+ may be derived from a sulfur-bearing parent molecule native to Jupiter. If so, the fragment must have penetrated at least as deep as the predicted NH4SH cloud at a pressure of approximately 1 to 2 bars. Stratospheric NH3 was also observed, which is consistent with fragment penetration below the cloud tops. Approximately 10(7) grams of neutral and ionized metals were observed in emission, including Mg II, Mg I, Si I, Fe I, and Fe II. Oxygen-containing molecules were conspicuous by their absence; upper limits for SO2, SO, CO, SiO, and H2O are derived.

Molecular characterization of isolates of Beauveria bassiana obtained from overwintering and summer populations of Sunn Pest (Eurygaster integriceps).

AIM: To examine whether isolates of the entomopathogenic fungus Beauveria bassiana are more closely associated to their summer hosts compared with overwintering hosts, with recently developed molecular tools based on mitochondrial regions. METHODS AND RESULTS: Primers for the traditional ITS1-5.8S-ITS2 region and two mitochondrial intergenic regions, namely, nad3-atp9 and atp6-rns, were used. All amplified products were sequenced, aligned and Neighbour-Joining (NJ), parsimony and Bayesian phylogenetic inference analyses were performed. The isolates examined were grouped with very good support into three distinct groups, two of them showed geographical correlation, but no clear association to their host. CONCLUSIONS: The mitochondrial intergenic regions used were more informative than the nuclear ITS1-5.8S-ITS2 sequences. The sequence variability observed, that allowed the phylogenetic placement of the isolates into distinct groups, depended on the geographical origin of the isolates and can be exploited for designing group-specific and isolate-specific primers for their genetic fingerprinting. No clear associations with summer Sunn Pest populations were observed. SIGNIFICANCE AND IMPACT OF THE STUDY: Studies on the genetic variability of biocontrol agents like B. bassiana are indispensable for the development of molecular tools for their future monitoring.

Immunogenicity of Z-DNA depends on the size of polynucleotide presented in complexes with methylated BSA.

The importance of polynucleotide size for immunogenicity was tested with size-fractionated Z-DNA. High molecular weight Z-DNA, larger than 1000 bp, was fragmented by digestion with micrococcal nuclease. Fractions corresponding to less than 60, 60-120, 100-200, 200-400 and 400-900 bp were isolated by gel filtration on Sepharose 4B. These fractions and the greater than 1000 bp Z-DNA were mixed with methylated BSA and the complexes were injected into C57BL/6 mice with RIBI adjuvant. Only one of four mice responded to the less than 60 bp immunogen. All the fractions larger than 60 bp induced specific anti-Z-DNA antibodies, mostly of IgG isotype, in all animals injected. Fractions larger than 200 bp induced antisera of higher titer than did 60-120 or 100-200 bp fractions. All positive sera reacted with Z-DNA but not with B-DNA and only very weakly with denatured DNA. In competitive assays, similar concentrations of fragments larger than 60 bp inhibited binding to immobilized Z-DNA. A higher concentration of less than 60 bp fragments was required for competitive binding. Even for a highly immunogenic nucleic acid that differs from the B-DNA conformation, a polynucleotide larger than 100 bp is much more immunogenic than smaller fragments.