Dense Molecular Clumps associated with the LMC Supergiant Shells LMC 4 \& LMC 5

We investigate the effects of Supergiant Shells (SGSs) and their interaction on dense molecular clumps by observing the Large Magellanic Cloud (LMC) star forming regions N48 and N49, which are located between two SGSs, LMC 4 and LMC 5. $^{12}$CO ($J$=3-2, 1-0) and $^{13}$CO ($J$=1-0) observations with the ASTE and Mopra telescopes have been carried out towards these regions. A clumpy distribution of dense molecular clumps is revealed with 7 pc spatial resolution. Large velocity gradient analysis shows that the molecular hydrogen densities ($n({\rm H}_2)$) of the clumps are distributed from low to high density ($10^3$-$10^5$ cm$^{-3}$) and their kinetic temperatures ($T_{\rm kin}$) are typically high (greater than $50$ K). These clumps seem to be in the early stages of star formation, as also indicated from the distribution of H$\alpha$, young stellar object candidates, and IR emission. We found that the N48 region is located in the high column density HI envelope at the interface of the two SGSs and the star formation is relatively evolved, whereas the N49 region is associated with LMC 5 alone and the star formation is quiet. The clumps in the N48 region typically show high $n({\rm H}_2)$ and $T_{\rm kin}$, which are as dense and warm as the clumps in LMC massive cluster-forming areas (30 Dor, N159). These results suggest that the large-scale structure of the SGSs, especially the interaction of two SGSs, works efficiently on the formation of dense molecular clumps and stars.Comment: 26 pages, 7 tables, 16 figure

Dense Clumps in Giant Molecular Clouds in the Large Magellanic Cloud: Density and Temperature Derived from 13^{13}CO(J=3−2J=3-2) Observations

In order to precisely determine temperature and density of molecular gas in the Large Magellanic Cloud, we made observations of optically thin $^{13}$CO($J=3-2$) transition by using the ASTE 10m telescope toward 9 peaks where $^{12}$CO($J=3-2$) clumps were previously detected with the same telescope. The molecular clumps include those in giant molecular cloud (GMC) Types I (with no signs of massive star formation), II (with HII regions only), and III (with HII regions and young star clusters). We detected $^{13}$CO($J=3-2$) emission toward all the peaks and found that their intensities are 3 -- 12 times lower than those of $^{12}$CO($J=3-2$). We determined the intensity ratios of $^{12}$CO($J=3-2$) to $^{13}$CO($J=3-2$), $R^{12/13}_{3-2}$, and $^{13}$CO($J=3-2$) to $^{13}$CO($J=1-0$), $R^{13}_{3-2/1-0}$, at 45\arcsec resolution. These ratios were used for radiative transfer calculations in order to estimate temperature and density of the clumps. The parameters of these clumps range kinetic temperature $T\mathrm{_{kin}}$ = 15 -- 200 K, and molecular hydrogen gas density $n(\mathrm{H_2})$ = 8$\times 10^2$ -- 7$\times 10^3$ cm$^{-3}$. We confirmed that the higher density clumps show higher kinetic temperature and that the lower density clumps lower kinetic temperature at a better accuracy than in the previous work. The kinetic temperature and density increase generally from a Type I GMC to a Type III GMC. We interpret that this difference reflects an evolutionary trend of star formation in molecular clumps. The $R^{13}_{3-2/1-0}$ and kinetic temperature of the clumps are well correlated with H$\alpha$ flux, suggesting that the heating of molecular gas $n(\mathrm{H_2})$ = $10^3$ -- $10^4$ cm$^{-3}$ can be explained by stellar FUV photons.Comment: 39 pages, 7 figures, 4 tables. Accepted for publication in The Astronomical Journa

Detection of anaerobic carbon monoxide-oxidizing thermophiles in hydrothermal environments.

Carboxydotrophic anaerobic thermophiles have been isolated from various hydrothermal environments and are considered to be important carbon monoxide (CO) scavengers or primary producers. However, the ecological factors that influence the distribution, abundance and CO-oxidizing activities of these bacteria are poorly understood. A previous study detected the carboxydotrophic bacteria Carboxydothermus spp. in a hot spring sample and found that they constituted up to 10% of the total bacterial cells. In this study, we investigated environmental features, potential microbial CO-oxidation activities and the abundance of Carboxydothermus spp. in various hot springs to determine environmental factors that affect CO oxidizers and to see whether Carboxydothermus spp. are common in these environments. We detected potential microbial CO-oxidation activities in samples that showed relatively high values of total organic carbon, total nitrogen, oxidation-reduction potential and soil-water content. The abundance of Carboxydothermus spp. did not correlate with the presence of potential microbial CO-oxidation activities; however, Carboxydothermus spp. were detected in a wide range of environments, suggesting that these bacteria are widely distributed in spite of the relatively low population size. This study implies that thermophilic CO oxidizers occur in a wide range of environments and oxidize CO in somewhat oxidative environments rich in organic matter

Coexistence of Trichome Variation in a Natural Plant Population: A Combined Study Using Ecological and Candidate Gene Approaches

The coexistence of distinct phenotypes within populations has long been investigated in evolutionary ecology. Recent studies have identified the genetic basis of distinct phenotypes, but it is poorly understood how the variation in candidate loci is maintained in natural environments. In this study, we examined fitness consequences and genetic basis of variation in trichome production in a natural population of Arabidopsis halleri subsp. gemmifera. Half of the individuals in the study population produced trichomes while the other half were glabrous, and the leaf beetle Phaedon brassicae imposed intensive damage to both phenotypes. The fitness of hairy and glabrous plants showed no significant differences in the field during two years. A similar result was obtained when sibling hairy and glabrous plants were transplanted at the same field site, whereas a fitness cost of trichome production was detected under a weak herbivory condition. Thus, equivalent fitness of hairy and glabrous plants under natural herbivory allows their coexistence in the contemporary population. The pattern of polymorphism of the candidate trichome gene GLABROUS1 (GL1) showed no evidence of long-term maintenance of trichome variation within the population. Although balancing selection under fluctuating biotic environments is often proposed to explain the maintenance of defense variation, the lack of clear evidence of balancing selection in the study population suggests that other factors such as gene flow and neutral process may have played relatively large roles in shaping trichome variation at least for the single population level

Usefulness of dexmedetomidine to prevent emergence agitation in a patient with Krabbe disease: a case report

Abstract Background We report the case of a child with Krabbe disease who underwent three repeated surgeries and anesthetic management, and we discuss the major concerns about Krabbe disease and the usefulness of a perioperative administration of dexmedetomidine to prevent emergence agitation and hypertension. The patient was scheduled to undergo bilateral orchiopexy, adenotonsillectomy, and knee flexor tendon lengthening under general anesthesia during a 2-year period. Case presentation Adenotonsillectomy was scheduled as the second operation when the patient was 4 years old. His height and body weight were 93 cm and 10.3 kg, respectively. Anesthesia was induced with 8% sevoflurane mixed with 6 L/min of O2 and maintained with N2O (3.5 L/min), O2 (1.5 L/min), and sevoflurane (1.5–2.0%). Upon completion of the right tonsillectomy, 1 h before the end of the surgery, a continuous infusion of dexmedetomidine (0.2 μg/kg/h) was started to prevent emergence agitation, irritability, resultant hypertension, and postoperative bleeding. Fentanyl (25 μg) was administered intravenously to reduce postoperative pain. The surgery was uneventful, and the patient’s emergence from general anesthesia was prompt. He exhibited no symptoms of emergence agitation or irritability. During his stay in the intensive care unit, 0.2–0.7 μg/kg/h of dexmedetomidine and 6.25 μg/h of fentanyl were continuously administered. The patient was discharged to the ward the following morning without complications. Conclusions The perioperative administration of dexmedetomidine was useful to prevent emergence agitation, hypertension, and resultant postoperative bleeding in a pediatric patient with Krabbe disease. Three repeated anesthetic management using inhalation anesthesia were completed uneventfully without muscle relaxants

ラットC6 グリオーマ細胞におけるケタミンとセボフルランの抗炎症作用関連遺伝子のスクリーニング

In the present study, we have conducted cDNA microarray in C6, rat brain glioma cell line, to assess anti-infl ammatory eff ects of ketamine and sevofl urane in the central nervous system. The cultured C6 cells were treated with ketamine （0-100 μM） and sevofl urane （0 and 0.66 mM）. Total RNA was extracted from the cells and labeled with fl uorescent dye and then hybridized with microarray slide, containing 1936 genes. Quantitative analysis of each gene expression was confi rmed by real-time polymerase chain reaction （PCR）. Microarray analyses showed that ketamine downregulated the expression of 4 proinfl ammatory cytokine genes and upregulated that of 2 antiinfl ammatory cytokine genes. On the other hand, sevofl urane downregulated the expression of 2 proinfl ammatory cytokines but upregulated that of two other proinfl ammatory cytokines. Furthermore, sevofl urane failed to stimulate the expressions of anti-infl ammatory cytokines. Although patterns of cytokine expression in response to ketamine and sevofl urane were diff erent from each other described above, both anesthetics downregulated a key cytokine, interleukin（ IL）-1β remarkably in microarray analysis, which was confi rmed by real time PCR. These results suggest that both ketamine and sevofl urane show mainly anti-infl ammatory properties through the inhibition of IL-1β