Volatile compounds of vegetarian soybean kapi, a fermented Thai food condiment

Kapi is a traditional shrimp paste used as a food condiment in Thailand. Several vegetarian soybean kapi, S1-S5, were fermented from various bacterial starter cultures isolated from commercial shrimp paste. The volatile compounds of S1-S5 were analyzed using SPME coupled with gaschromatography/mass spectrometry and compared to three samples of commercial vegetarian kapi (J1-J3) and commercial shrimp pastes (K1-K3). 124 volatile compounds consisting of aldehydes, alcohols,ketones, acids and esters, N-containing compounds, aromatic compounds, S-containing compounds, miscellaneous, indoles and hydrocarbons were identified. Principle component analysis and cluster analysis separated the volatile profile of the fermented samples into four groups. Vegetarian soybean kapi, S1, S4 and S5 produced from Bacillus subtilis IS4, TISTR10 and TISTR1, respectively, were classified into the following groups containing commercial kapi (J1, J2, K2 and K3), that had a predominance of indole, S-containing and N-containing compounds. Sensory evaluation of S1 showed a strong kapi odor with higher scores among the vegetarian soybean kapi and there were no significant differences in evaluation scores between S1 and commercial vegetarian kapi J1-J3. These data demonstrate that B. subtilis IS4 can be employed as a starter culture to produce an acceptable vegetarian soybean kapi substitute for shrimp paste kapi.Key words: Vegetarian kapi, volatile compounds, fermentation, principal component analysis, cluster analysis

Volatile compounds of vegetarian soybean kapi, a fermented Thai food condiment

Kapi is a traditional shrimp paste used as a food condiment in Thailand. Several vegetarian soybean kapi, S1-S5, were fermented from various bacterial starter cultures isolated from commercial shrimp paste. The volatile compounds of S1-S5 were analyzed using SPME coupled with gaschromatography/mass spectrometry and compared to three samples of commercial vegetarian kapi (J1-J3) and commercial shrimp pastes  (K1-K3). 124 volatile compounds consisting of aldehydes, alcohols, ketones, acids and esters, N-containing compounds, aromatic compounds, S-containing compounds, miscellaneous, indoles and hydrocarbons were identified. Principle component analysis and cluster analysis separated the volatile profile of the fermented samples into four groups. Vegetarian soybean kapi, S1, S4 and S5 produced from Bacillus subtilis IS4, TISTR10 and TISTR1, respectively, were classified into the following groups containing commercial kapi (J1, J2, K2 and K3), that had a predominance of indole, S-containing and N-containing compounds. Sensory evaluation of S1 showed a strong kapi odor with higher scores among the vegetarian soybean kapi and there were no significant differences in evaluation scores between S1 and commercial vegetarian kapi J1-J3. These data demonstrate that B. subtilis IS4 can be employed as a starter culture to produce an acceptable vegetarian soybean kapi substitute for shrimp paste kapi.Key words: Vegetarian kapi, volatile compounds, fermentation, principal component analysis, cluster analysis

The Apparently Decaying Orbit of WASP-12

We present new transit and occultation times for the hot Jupiter WASP-12b. The data are compatible with a constant period derivative: $\dot{P}=-29 \pm 3$ ms yr$^{-1}$ and $P/\dot{P}= 3.2$ Myr. However, it is difficult to tell whether we have observed orbital decay, or a portion of a 14-year apsidal precession cycle. If interpreted as decay, the star's tidal quality parameter $Q_\star$ is about $2\times 10^5$. If interpreted as precession, the planet's Love number is $0.44\pm 0.10$. Orbital decay appears to be the more parsimonious model: it is favored by $\Delta\chi^2=5.5$ despite having two fewer free parameters than the precession model. The decay model implies that WASP-12 was discovered within the final $\sim$0.2% of its existence, which is an unlikely coincidence but harmonizes with independent evidence that the planet is nearing disruption. Precession does not invoke any temporal coincidence, but does require some mechanism to maintain an eccentricity of $\approx$0.002 in the face of rapid tidal circularization. To distinguish unequivocally between decay and precession will probably require a few more years of monitoring. Particularly helpful will be occultation timing in 2019 and thereafter.Comment: 10 pages [AAS journals, in press, note added in proof

Quantifying structure in networks

We investigate exponential families of random graph distributions as a framework for systematic quantification of structure in networks. In this paper we restrict ourselves to undirected unlabeled graphs. For these graphs, the counts of subgraphs with no more than k links are a sufficient statistics for the exponential families of graphs with interactions between at most k links. In this framework we investigate the dependencies between several observables commonly used to quantify structure in networks, such as the degree distribution, cluster and assortativity coefficients.Comment: 17 pages, 3 figure

Detection of Planetary Emission from the Exoplanet TrES-2 using Spitzer /IRAC

We present here the results of our observations of TrES-2 using the Infrared Array Camera on Spitzer. We monitored this transiting system during two secondary eclipses, when the planetary emission is blocked by the star. The resulting decrease in flux is 0.127%+-0.021%, 0.230%+-0.024%, 0.199%+-0.054%, and 0.359%+-0.060%, at 3.6 microns, 4.5 microns, 5.8 microns, and 8.0 microns, respectively. We show that three of these flux contrasts are well fit by a black body spectrum with T_{eff}=1500 K, as well as by a more detailed model spectrum of a planetary atmosphere. The observed planet-to-star flux ratios in all four IRAC channels can be explained by models with and without a thermal inversion in the atmosphere of TrES-2, although with different atmospheric chemistry. Based on the assumption of thermochemical equilibrium, the chemical composition of the inversion model seems more plausible, making it a more favorable scenario. TrES-2 also falls in the category of highly irradiated planets which have been theoretically predicted to exhibit thermal inversions. However, more observations at infrared and visible wavelengths would be needed to confirm a thermal inversion in this system. Furthermore, we find that the times of the secondary eclipses are consistent with previously published times of transit and the expectation from a circular orbit. This implies that TrES-2 most likely has a circular orbit, and thus does not obtain additional thermal energy from tidal dissipation of a non-zero orbital eccentricity, a proposed explanation for the large radius of this planet.Comment: 8 pages, 4 figures, 2 tables. Accepted for publication in the Astrophysical Journal. V2: New figure added ; other minor changes throughou

Thermal Phase Variations of WASP-12b: Defying Predictions

[Abridged] We report Warm Spitzer full-orbit phase observations of WASP-12b at 3.6 and 4.5 micron. We are able to measure the transit depths, eclipse depths, thermal and ellipsoidal phase variations at both wavelengths. The large amplitude phase variations, combined with the planet's previously-measured day-side spectral energy distribution, is indicative of non-zero Bond albedo and very poor day-night heat redistribution. The transit depths in the mid-infrared indicate that the atmospheric opacity is greater at 3.6 than at 4.5 micron, in disagreement with model predictions, irrespective of C/O ratio. The secondary eclipse depths are consistent with previous studies. We do not detect ellipsoidal variations at 3.6 micron, but our parameter uncertainties -estimated via prayer-bead Monte Carlo- keep this non-detection consistent with model predictions. At 4.5 micron, on the other hand, we detect ellipsoidal variations that are much stronger than predicted. If interpreted as a geometric effect due to the planet's elongated shape, these variations imply a 3:2 ratio for the planet's longest:shortest axes and a relatively bright day-night terminator. If we instead presume that the 4.5 micron ellipsoidal variations are due to uncorrected systematic noise and we fix the amplitude of the variations to zero, the best fit 4.5 micron transit depth becomes commensurate with the 3.6 micron depth, within the uncertainties. The relative transit depths are then consistent with a Solar composition and short scale height at the terminator. Assuming zero ellipsoidal variations also yields a much deeper 4.5 micron eclipse depth, consistent with a Solar composition and modest temperature inversion. We suggest future observations that could distinguish between these two scenarios.Comment: 19 pages, 10 figures, ApJ in press. Improved discussion of gravity brightenin

OncoLog Volume 40, Number 01 January-March 1995

Genetic testing: a new paradigm for medullary thyroid carcinoma Bone marrow transplantation now available as an outpatient procedure Adjuvant chemotherapy for breast cancer: 20 years of progress at M. D. Andersonhttps://openworks.mdanderson.org/oncolog/1049/thumbnail.jp