Radical and ion molecule mechanisms in the polymerization of hydrocarbons and chlorosilanes in RF plasmas at low pressures ( 1.0 torr)

The ion-molecule and the radical-molecule mechanisms are responsible for the dissociation of hydrocarbons, and chlorosilane monomers and the formation of polymerized species, respectively, in the plasma state of a RF discharge. In the plasma, of a mixture of monomer with Ar, the rate determining step for both dissociation and polymerization is governed by an ion-molecular type interaction. Additions of H2 or NH3 to the monomer Ar(+) mixture transforms the rate determining step from an ion-molecular interaction to a radical-molecule type interaction for both monomer dissociation and polymerization processes

Homogeneous reactions of hydrocarbons, silane, and chlorosilanes in radiofrequency plasmas at low pressures

The ion-molecule and radical-molecule mechanisms are responsible for the dissociation of hydrocarbon, silane, and chlorosilane monomers and the formation of polymerized species, respectively, in an RF plasma discharge. In a plasma containing a mixture of monomer and argon the rate-determining step for both dissociation and polymerization is governed by an ion-molecule type of interaction. Adding hydrogen or ammonia to the monomer-argon mixture transforms the rate-determining step from an ion-molecule interaction to a radical-molecule interaction for both monomer dissociation and polymerization

Acute toxicity, behavioural response and haematological alterations of Catla catla exposed to Reactive Red 120 textile dye

Textile is one of the most economic sectors in India. However, continuous discharge of textile waste waters loaded with a variety of synthetic dyes pose a huge threat to the surrounding ecosystems. Textile azo dyes are serious pollutants of the aquatic environment because of their environmental persistence and ability to be accumulated by aquatic organism. Here, we investigated the toxic effects of azo dye, Reactive Red 120 (RR 120) on the behavioural and some haematological parameters of the freshwater fish, Indian major carp Catla catla fingerlings. The fingerlings were procured and acclimatized in the laboratory condition for 15 days according to APHA. The LC50 value of RR 120 for C. catla, fingerlings was 35 mg L-1 for 96 h. Catla fish showed an abnormal behavioural change against azo dye RR 120 intoxication such as opercular movement, sluggish, lethargic and abnormal swimming, and loss of muscular tetany. Then, they were grouped in to 10 (10 in each). Among this one was considered as control and other groups of fingerlings were exposed to sub lethal concentrations (0.35, 0.7 and 3.5 mg L-1) in triplicate of RR 120 for 30 days. At fixed interval (10, 20,30 days) after the exposure blood samples were collected and were analyzed. Results obtained from this study show significantly RBC, Hb and PCV value exhibited significant decreased whereas, WBC, MCHC, MCV and MCH were increased in fish as compared control in all RR 120 exposed fingerlings. The present study clearly indicates the toxic effects of RR 120 even at sublethal concentrations of exposed fingerlings

Acute toxicity, behavioural response and haematological alterations of Catla catla exposed to Reactive Red 120 textile dye

275-279Textile is one of the most economic sectors in India. However, continuous discharge of textile waste waters loaded with a variety of synthetic dyes pose a huge threat to the surrounding ecosystems. Textile azo dyes are serious pollutants of the aquatic environment because of their environmental persistence and ability to be accumulated by aquatic organism. Here, we investigated the toxic effects of azo dye, Reactive Red 120 (RR 120) on the behavioural and some haematological parameters of the freshwater fish, Indian major carp Catla catla fingerlings. The fingerlings were procured and acclimatized in the laboratory condition for 15 days according to APHA. The LC50 value of RR 120 for C. catla, fingerlings was 35 mg L-1 for 96 h. Catla fish showed an abnormal behavioural change against azo dye RR 120 intoxication such as opercular movement, sluggish, lethargic and abnormal swimming, and loss of muscular tetany. Then, they were grouped in to 10 (10 in each). Among this one was considered as control and other groups of fingerlings were exposed to sub lethal concentrations (0.35, 0.7 and 3.5 mg L-1) in triplicate of RR 120 for 30 days. At fixed interval (10, 20, 30 days) after the exposure blood samples were collected and were analyzed. Results obtained from this study show significantly RBC, Hb and PCV value exhibited significant decreased whereas, WBC, MCHC, MCV and MCH were increased in fish as compared control in all RR 120 exposed fingerlings. The present study clearly indicates the toxic effects of RR 120 even at sublethal concentrations of exposed fingerlings

How are deep soils responding to warming?

Scientists aim to integrate observations from deep-soil-warming experiments worldwide to better understand how ecosystems vital to food security and environmental health will react to climate change

The LBDS Hercules sample of mJy radio sources at 1.4 GHz - II. Redshift distribution, radio luminosity function, and the high-redshift cut-off

{Abridged} A combination of spectroscopy and broadband photometric redshifts has been used to find the complete redshift distribution of the Hercules sample of millijansky radio sources. These data have been used to examine the evolution of the radio luminosity function (RLF) and its high-redshift cut-off. New redshifts have been measured for eleven sources, and a further ten upper limits are given. The total number of sources with known redshifts in the sample is now 47 (65%). We calculated broadband photometric redshifts for the remaining one-third of the sample. For the luminosity range probed by the present study (P_1.4 > 10^24.5 W/Hz/sr), we use the V/V_max test to show conclusively that there is a deficit of high-redshift (z > 2-2.5) objects. Comparison with the model RLFs of Dunlop & Peacock (1990) shows that our data can now exclude pure luminosity evolution. Two of the models of DP90, and the RLF deduced by direct binning of the data, both favour a luminosity dependence for the high-redshift cut-off, with lower-luminosity sources (P_1.4 \simeq 10^24 W/Hz/sr) in decline by z \simeq 1-1.5 while higher-luminosity sources (P_1.4 \simeq 10^{25-26} W/Hz/sr) decline in comoving number density beyond z \simeq 2-2.5.Comment: Revised version submitted to MNRAS. 16 pages, 12 figure

Warming and elevated CO2 promote rapid incorporation and degradation of plant-derived organic matter in an ombrotrophic peatland

Rising temperatures have the potential to directly affect carbon cycling in peatlands by enhancing organic matter (OM) decomposition, contributing to the release of CO2 and CH4 to the atmosphere. In turn, increasing atmospheric CO2 concentration may stimulate photosynthesis, potentially increasing plant litter inputs belowground and transferring carbon from the atmosphere into terrestrial ecosystems. Key questions remain about the magnitude and rate of these interacting and opposing environmental change drivers. Here, we assess the incorporation and degradation of plant- and microbe-derived OM in an ombrotrophic peatland after 4 years of whole-ecosystem warming (+0, +2.25, +4.5, +6.75 and +9°C) and two years of elevated CO2 manipulation (500 ppm above ambient). We show that OM molecular composition was substantially altered in the aerobic acrotelm, highlighting the sensitivity of acrotelm carbon to rising temperatures and atmospheric CO2 concentration. While warming accelerated OM decomposition under ambient CO2, new carbon incorporation into peat increased in warming × elevated CO2 treatments for both plant- and microbe-derived OM. Using the isotopic signature of the applied CO2 enrichment as a label for recently photosynthesized OM, our data demonstrate that new plant inputs have been rapidly incorporated into peat carbon. Our results suggest that under current hydrological conditions, rising temperatures and atmospheric CO2 levels will likely offset each other in boreal peatlands

Spectroscopy and Stellar Populations of Star-forming Galaxies at z~3 in the Hubble Deep Field - South

We present results of VLT/FORS2 spectroscopy of galaxies at z~3 in the Hubble Deep Field-South (HDF-S). A sample of galaxies was drawn from the photo-z catalogue based on the HST/WFPC2 optical images and the deep near-infrared images obtained with VLT/ISAAC as a part of the FIRES project. We selected galaxies with photometric redshift between 2.5 and 4. Most of the selected galaxies are bright in rest-frame UV wavelengths and satisfy color selection criteria of Lyman break galaxies (LBGs) at z~3. The number of target galaxies with I(AB)<25.0 was 15. We identified new 5 firm and 2 probable redshifts in addition to confirmations of previously known 6 galaxies at z~3. We found 6 among these 13 galaxies lie at a quite narrow redshift range at z = 2.80+-0.01. We examined stellar populations of the galaxies with spectroscopic redshifts through comparisons of their optical and near-IR photometry data with template spectra generated by a population synthesis code. The ages from the onset of star formation for these star-forming galaxies with I<=25.0 are typically 50-200 Myr, and their stellar masses are between (0.5-5) x 10^10 M_sun, consistent with previous studies. We also compared these SED fitting results with those for distant red galaxies (DRGs) at z>2 discovered by FIRES. DRGs have larger stellar masses, larger dust attenuation than our UV-luminous LBG sample, and their star formation rates are often comparable to LBGs. These trends suggest that majority of DRGs are indeed the most massive systems at the redshift and are still in the active star-forming phase. Unless the number density of DRGs is much smaller than LBGs, estimates based on UV selected sample could miss substantial part of stellar mass density at z~3.Comment: 13 pages, 10 Postscript figures, accepted for publication in A&

The phosphorylated prodrug FTY720 is a histone deacetylase inhibitor that reactivates ERα expression and enhances hormonal therapy for breast cancer

Estrogen receptor-α (ERα)-negative breast cancer is clinically aggressive and does not respond to conventional hormonal therapies. Strategies that lead to re-expression of ERα could sensitize ERα-negative breast cancers to selective ER modulators. FTY720 (fingolimod, Gilenya), a sphingosine analog, is the Food and Drug Administration (FDA)-approved prodrug for treatment of multiple sclerosis that also has anticancer actions that are not yet well understood. We found that FTY720 is phosphorylated in breast cancer cells by nuclear sphingosine kinase 2 and accumulates there. Nuclear FTY720-P is a potent inhibitor of class I histone deacetylases (HDACs) that enhances histone acetylations and regulates expression of a restricted set of genes independently of its known effects on canonical signaling through sphingosine-1-phosphate receptors. High-fat diet (HFD) and obesity, which is now endemic, increase breast cancer risk and have been associated with worse prognosis. HFD accelerated the onset of tumors with more advanced lesions and increased triple-negative spontaneous breast tumors and HDAC activity in MMTV-PyMT transgenic mice. Oral administration of clinically relevant doses of FTY720 suppressed development, progression and aggressiveness of spontaneous breast tumors in these mice, reduced HDAC activity and strikingly reversed HFD-induced loss of estrogen and progesterone receptors in advanced carcinoma. In ERα-negative human and murine breast cancer cells, FTY720 reactivated expression of silenced ERα and sensitized them to tamoxifen. Moreover, treatment with FTY720 also re-expressed ERα and increased therapeutic sensitivity of ERα-negative syngeneic breast tumors to tamoxifen in vivo more potently than a known HDAC inhibitor. Our work suggests that a multipronged attack with FTY720 is a novel combination approach for effective treatment of both conventional hormonal therapy-resistant breast cancer and triple-negative breast cancer

Climate warming and elevated CO2 alter peatland soil carbon sources and stability

Peatlands are an important carbon (C) reservoir storing one-third of global soil organic carbon (SOC), but little is known about the fate of these C stocks under climate change. Here, we examine the impact of warming and elevated atmospheric CO$_{2}$ concentration (eCO$_{2}$) on the molecular composition of SOC to infer SOC sources (microbe-, plant- and fire-derived) and stability in a boreal peatland. We show that while warming alone decreased plant- and microbe-derived SOC due to enhanced decomposition, warming combined with eCO$_{2}$ increased plant-derived SOC compounds. We further observed increasing root-derived inputs (suberin) and declining leaf/needle-derived inputs (cutin) into SOC under warming and eCO$_{2}$. The decline in SOC compounds with warming and gains from new root-derived C under eCO$_{2}$, suggest that warming and eCO$_{2}$ may shift peatland C budget towards pools with faster turnover. Together, our results indicate that climate change may increase inputs and enhance decomposition of SOC potentially destabilising C storage in peatlands