The OSIRIS-REx Thermal Emission Spectrometer (OTES) will provide remote measurements of mineralogy and thermophysical properties of Bennu to map its surface, help select the OSIRIS-REx sampling site, ...and investigate the Yarkovsky effect. OTES is a Fourier Transform spectrometer covering the spectral range 5.71–100 μm (
1750
–
100
cm
−
1
) with a spectral sample interval of
8.66
cm
−
1
and a 6.5-mrad field of view. The OTES telescope is a 15.2-cm diameter Cassegrain telescope that feeds a flat-plate Michelson moving mirror mounted on a linear voice-coil motor assembly. A single uncooled deuterated
l
-alanine doped triglycine sulfate (DLATGS) pyroelectric detector is used to sample the interferogram every two seconds. Redundant ∼0.855 μm laser diodes are used in a metrology interferometer to provide precise moving mirror control and IR sampling at 772 Hz. The beamsplitter is a 38-mm diameter, 1-mm thick chemical vapor deposited diamond with an antireflection microstructure to minimize surface reflection. An internal calibration cone blackbody target provides radiometric calibration. The radiometric precision in a single spectrum is
≤
2.2
×
10
−
8
W
cm
−
2
sr
−
1
/
cm
−
1
between 300 and
1350
cm
−
1
. The absolute integrated radiance error is
<
1
%
for scene temperatures ranging from 150 to 380 K. The overall OTES envelope size is
37.5
×
28.9
×
52.2
cm
, and the mass is 6.27 kg. The power consumption is 10.8 W average. OTES was developed by Arizona State University with Moog Broad Reach developing the electronics. OTES was integrated, tested, and radiometrically calibrated on the Arizona State University campus in Tempe, AZ.
Previous research has documented advantages and disadvantages of early bilinguals, defined as learning a 2nd language by school age and using both languages since that time. Relative to monolinguals, ...early bilinguals manifest deficits in lexical access but benefits in executive function. We investigated whether becoming bilingual after childhood (late bilinguals) can produce the cognitive advantages and disadvantages typical of early bilinguals. Participants were 30 monolingual English speakers, 30 late English-Spanish bilinguals, and 30 early Spanish-English bilinguals who completed a picture naming task (lexical access) and an attentional network task (executive function). Late and early bilinguals manifested equivalent cognitive effects in both tasks, demonstrating lexical access deficits and executive function benefits. These findings provide support for the hypothesis that cognitive effects associated with bilingualism arise as the result of proficient, habitual use of 2 languages and not of developmental changes associated with becoming bilingual during childhood.
The Lucy Thermal Emission Spectrometer (L’TES) will provide remote measurements of the thermophysical properties of the Trojan asteroids studied by the Lucy mission. L’TES is build-to-print hardware ...copy of the OTES instrument flown on OSIRIS-REx. It is a Fourier Transform spectrometer covering the spectral range 5.71–100 μm (1750–100 cm
−1
) with spectral sampling intervals of 8.64, 17.3, and 34.6 cm
−1
and a 7.3-mrad field of view. The L’TES telescope is a 15.2-cm diameter Cassegrain telescope that feeds a flat-plate Michelson moving mirror mounted on a linear voice-coil motor assembly to a single uncooled deuterated
l
-alanine doped triglycine sulfate (DLATGS) pyroelectric detector. A significant firmware change from OTES is the ability to acquire interferograms of different length and spectral resolution with acquisition times of 0.5, 1, and 2 seconds. A single ∼0.851 μm laser diode is used in a metrology interferometer to provide precise moving mirror control and IR sampling at 772 Hz. The beamsplitter is a 38-mm diameter, 1-mm thick chemical vapor deposited diamond with an antireflection microstructure to minimize surface reflection. An internal calibration cone blackbody target, together with observations of space, provides radiometric calibration. The radiometric precision in a single spectrum is ≤2.2 × 10
−8
W cm
−2
sr
−1
/cm
−1
between 300 and 1350 cm
−1
. The absolute temperature error is <2 K for scene temperatures >75 K. The overall L’TES envelope size is 37.6 × 29.0 × 30.4 cm, and the mass is 6.47 kg. The power consumption is 12.6 W average. L’TES was developed by Arizona State University with AZ Space Technologies developing the electronics. L’TES was integrated, tested, and radiometrically calibrated on the Arizona State University campus in Tempe, AZ. Initial data from space have verified the instrument’s radiometric and spatial performance.
English-acquiring children frequently make pronoun case errors, while German-acquiring children rarely do. Nonetheless, German-acquiring children frequently make article case errors. It is proposed ...that when child-directed speech contains a high percentage of case-ambiguous forms, case errors are common in child language; when percentages are low, case errors are rare. Input to English and German children was analyzed for percentage of case-ambiguous personal pronouns on adult tiers of corpora from 24 English-acquiring and 24 German-acquiring children. Also analyzed for German was the percentage of case-ambiguous articles. Case-ambiguous pronouns averaged 63·3% in English, compared with 7·6% in German. The percentage of case-ambiguous articles in German was 77·0%. These percentages align with the children's errors reported in the literature. It appears children may be sensitive to levels of ambiguity such that low ambiguity may aid error-free acquisition, while high ambiguity may blind children to case distinctions, resulting in errors.
A series of double-stranded, cyclic oligodeoxynucleotides with non-nucleotide bridges have been synthesized, and their physicochemical properties and susceptibility to enzymes have been investigated. ...These bridged duplexes are of potential interest for their binding properties to transcription factors and other DNA-binding proteins. Triethylene glycol has been employed as the bridge to alter the lipophilicity of the duplex and avoid the potential for enzymatic cleavage. The synthetic route involved the synthesis of a 3'-phosphorylated, nicked double-stranded precursor with the final internucleotide bond being formed chemically using a water soluble carbodiimide. These bridged duplexes have high thermal dissociation temperatures, and the Tm for a triethylene-bridged 20 base pair duplex was higher than that for the corresponding pentathymidylate-bridged duplex. EcoR I endonuclease cleaved a ligated, bridged duplex at a slower rate than the corresponding unmodified duplex, whereas the unligated, bridged duplex was cleaved more rapidly. Sufficient amounts of the bridged octamer and dodecamer were prepared for proton NMR spectroscopic studies, and 2D COSY and NOESY spectra were obtained. The results indicate that the ligated duplex has a B-form conformation.
The versatility of mixed model procedures in investigating large, unbalanced sets of genotype by environment data is illustrated on an historic set of yields from a South Australian oat evaluation ...program. Information on specific genotypic traits is included in the analysis in order to isolate unexplained genotype by environment interaction.PUBLICATION ABSTRACT
We have previously demonstrated that P. aeruginosa can have profound effects on the intestinal epithelial barrier via one of its virulence factors, the PA-I lectin/adhesin. The aims of the present ...study were to further characterize the interaction of P. aeruginosa and the intestinal epithelium using both in vitro and in vivo approaches.
In vitro assays examining the effect of bacterial growth phase, epithelial cell contact, and butanoyl homoserine lactone (C4-HSL), a quorum sensing signaling molecule know to affect various extracellular virulence factors in P. aeruginosa, on PA-I expression in P. aeruginosa were performed. In vivo studies were carried out by modeling catabolic stress in mice using a 30% surgical hepatectomy and direct introduction of P. aeruginosa and various virulence components into the cecum. The effect of this model on PA-I expression in P. aeruginosa was determined.
Results demonstrated that PA-I expression in P. aeruginosa is affected by its phase of growth, its contact to the intestinal epithelium, and its exposure to the quorum sensing molecule, C4-HSL. Furthermore, data from the present study suggest that the PA-I lectin/adhesin of P. aeruginosa may be increased in vivo by local factors within the cecum of mice in response to surgical stress.
These data indicate that multiple factors present in the intestinal microenvironment of a stressed host may induce certain opportunistic pathogens to express key virulence factors leading to a state of lethal gut-derived sepsis.
Pan-African terranes: realizing the metal potential Foster, R. P.; Leahy, K.; Hunns, S. R. ...
Institution of Mining and Metallurgy. Transactions. Section B: Applied earth sciences,
04/2001, Letnik:
110, Številka:
1
Journal Article
Recenzirano
The gold and base-metal potential of the Pan-African orogens is reviewed. Explorationists in these terranes face two scenarios: ground that has already been explored but merits re-evaluation in the ...light of new techniques or data, such as the Central African Copperbelt and the Damara Belt, and ground that has been subject to little previous exploration, such as the Mozambique Belt and Hoggar. It is predicted that genetic modelling, based on the source-migration-trap paradigm used in petroleum exploration and following a progression from geodynamic domain scale through terranes and mineral play types to prospect scale, will play an important part in future exploration in Africa. The greatest immediate potential of this methodology is seen to lie in its application to the Copperbelt, the Damaran Mobile Belt, the West Congolian Belt and, possibly, the exposed parts of the North African Altaid-style orogen from Hoggar to the Red Sea.
Ischemic preconditioning (IPC) protects the rat retina against the injury that ordinarily follows prolonged ischemia. It has been shown that release of adenosine, de novo protein synthesis, and ...mediators, such as protein kinase C and K(ATP) channels, is required for IPC protection. However, the molecular mechanisms of neuroprotection by IPC are unknown. Retinal cells die after ischemia by necrosis and apoptosis. This study was undertaken to investigate the effect of IPC on apoptosis after ischemia and some of the key proteins involved in the apoptotic cascade.
Retinal ischemia or IPC was produced in anesthetized Sprague-Dawley rats by increasing intraocular pressure above systolic arterial pressure. Retinal ischemia was induced 24 hours after either IPC or sham IPC. TUNEL staining was used to quantitate the number of cells with DNA fragmentation. The authors examined expression of cleaved forms of caspases-2 and -3, bax, and poly-adenosine diphosphate-ribose-polymerase (PARP) by Western blot analysis for evidence of apoptosis-related gene expression. To examine possible mechanisms of apoptosis after ischemia, the authors studied the expression of mitogen-activated protein kinases (MAP kinases). Functional recovery after ischemia was measured using electroretinography, and retinal histology was examined and quantitated by light microscopy.
Positive TUNEL staining, increases in caspase-2 and -3 cleavage, expression of bax and PARP, and activation of MAP kinases were found with ischemia. IPC attenuated these changes, but paradoxically, IPC itself triggered increased expression of MAP kinases.
IPC protects against ischemic injury, in part, by diminishing apoptosis-related gene expression and by altering protein phosphorylation.
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