Composition of Jupiter irregular satellites sheds light on their origin

Irregular satellites of Jupiter with their highly eccentric, inclined and distant orbits suggest that their capture took place just before the giant planet migration. We aim to improve our understanding of the surface composition of irregular satellites of Jupiter to gain insight into a narrow time window when our Solar System was forming. We observed three Jovian irregular satellites, Himalia, Elara, and Carme, using a medium-resolution 0.8-5.5 micro m spectrograph on the National Aeronautics and Space Administration (NASA) Infrared Telescope Facility (IRTF). Using a linear spectral unmixing model we have constrained the major mineral phases on the surface of these three bodies. Our results confirm that the surface of Himalia, Elara, and Carme are dominated by opaque materials such as those seen in carbonaceous chondrite meteorites. Our spectral modeling of NIR spectra of Himalia and Elara confirm that their surface composition is the same and magnetite is the dominant mineral. A comparison of the spectral shape of Himalia with the two large main C-type asteroids, Themis (D 176 km) and Europa (D 352 km), suggests surface composition similar to Europa. The NIR spectrum of Carme exhibits blue slope up to 1.5 microm and is spectrally distinct from those of Himalia and Elara. Our model suggests that it is compositionally similar to amorphous carbon. Himalia and Elara are compositionally similar but differ significantly from Carme. These results support the hypotheses that the Jupiter irregular satellites are captured bodies that were subject to further breakup events and clustered as families based on their similar physical and surface compositions

Star formation activity in the Galactic H II region Sh2-297

We present a multiwavelength study of the Galactic H II region Sh2-297, located in Canis Major OB1 complex. Optical spectroscopic observations are used to constrain the spectral type of ionizing star HD 53623 as B0V. The classical nature of this H II region is affirmed by the low values of electron density and emission measure, which are calculated to be 756 cm^-3 and 9.15 x 10^5 cm^-6 pc using the radio continuum observations at 610 and 1280 MHz, and VLA archival data at 1420 MHz. To understand local star formation, we identified the young stellar object (YSO) candidates in a region of area ~ 7.5' x 7.5' centered on Sh2-297 using grism slitless spectroscopy (to identify the Halpha emission line stars), and near infrared (NIR) observations. NIR YSO candidates are further classified into various evolutionary stages using color-color (CC) and color-magnitude (CM) diagrams, giving 50 red sources (H-K > 0.6) and 26 Class II-like sources. The mass and age range of the YSOs are estimated to be ~ 0.1 - 2 Msolar and 0.5 - 2 Myr using optical (V/V-I) and NIR (J/J-H) CM diagrams. The mean age of the YSOs is found to be ~ 1 Myr, which is of the order of dynamical age of 1.07 Myr of the H II region. Using the estimated range of visual extinction (1.1 - 25 mag) from literature and NIR data for the region, spectral energy distribution (SED) models have been implemented for selected YSOs which show masses and ages to be consistent with estimated values. The spatial distribution of YSOs shows an evolutionary sequence, suggesting triggered star formation in the region. The star formation seems to have propagated from the ionizing star towards the cold dark cloud LDN1657A located west of Sh2-297.Comment: 19 pages, 13 figures, 3 tables. Accepted for publication in The Astrophysical Journa

Lipid peroxidation and antioxidant status in head and neck squamous cell carcinoma patients

Oxidative stress, a consequence of an imbalance between the formation and inactivation of reactive oxygen species, may be involved in the pathogenesis of many diseases including cancer. To evaluate the magnitude of oxidative stress, a study on the plasma levels of superoxide dismutase, total thiols, ascorbic acid and malondialdehyde (MDA) has been done in head and neck squamous cell carcinoma patients before the start of any oncological treatment and compared with healthy controls. The specific activity of superoxide dismutase in cancer patients is decreased significantly when compared to the control (p < 0.05). The total thiol and ascorbic acid levels are significantly reduced (p < 0.005) whereas MDA levels are significantly increased in the patients (p < 0.00005). Our findings show that the oxidative stress is elevated in cancer patients as evidenced by elevated levels of lipid peroxidation products and depletion of enzymatic and non-enzymatic antioxidants

On Line Chemical Cleaning of Critical Heat Exchangers for Cooling Water Deposit and their Control to Sustain High Production Level of Methanol - An Experience and Case Study at GNFC

Deposit control is the most critical aspect of cooling water treatment because it is directly related to very purpose for a cooling system heat removal. Any deposit present in heat transfer surfaces impairs heat removal and there for reduces the efficiency of entire system. Cooling water deposits are of two types - scales and fouling. Scales are hard dense, crystalline deposits for-med by the precipitation of dissolved materials when their solubility have been exceeded due to change in conditions. Foulants form softer non crystalline deposits because suspended materials settle out or adhere to metal surfaces

History of early life adversity is associated with increased food addiction and sex-specific alterations in reward network connectivity in obesity.

Background:Neuroimaging studies have identified obesity-related differences in the brain's resting state activity. An imbalance between homeostatic and reward aspects of ingestive behaviour may contribute to obesity and food addiction. The interactions between early life adversity (ELA), the reward network and food addiction were investigated to identify obesity and sex-related differences, which may drive obesity and food addiction. Methods:Functional resting state magnetic resonance imaging was acquired in 186 participants (high body mass index [BMI]: ≥25: 53 women and 54 men; normal BMI: 18.50-24.99: 49 women and 30 men). Participants completed questionnaires to assess ELA (Early Traumatic Inventory) and food addiction (Yale Food Addiction Scale). A tripartite network analysis based on graph theory was used to investigate the interaction between ELA, brain connectivity and food addiction. Interactions were determined by computing Spearman rank correlations, thresholded at q &lt; 0.05 corrected for multiple comparisons. Results:Participants with high BMI demonstrate an association between ELA and food addiction, with reward regions playing a role in this interaction. Among women with high BMI, increased ELA was associated with increased centrality of reward and emotion regulation regions. Men with high BMI showed associations between ELA and food addiction with somatosensory regions playing a role in this interaction. Conclusions:The findings suggest that ELA may alter brain networks, leading to increased vulnerability for food addiction and obesity later in life. These alterations are sex specific and involve brain regions influenced by dopaminergic or serotonergic signalling

Development and Validation of a Stability-Indicating RP-HPLC Method for Duloxetine Hydrochloride in its Bulk and Tablet Dosage Form

The objective of the present work was to develop a stability-indicating RP-HPLC method for duloxetine hydrochloride (DUL) in the presence of its degradation products generated from forced decomposition studies. The drug substance was found to be susceptible to stress conditions of acid hydrolysis. The drug was found to be stable to dry heat, photodegradation, oxidation and basic condition attempted. Successful separation of the drug from the degradation products formed under acidic stress conditions was achieved on a Hypersil C-18 column (250 mm × 4.6 mm id, 5μm particle size) using acetonitrile: 0.01 M potassium dihydrogen phosphate buffer (pH 5.4 adjusted with orthophosphoric acid) (50:50, v/v) as the mobile phase at a flow rate of 1.0 ml/min. Quantification was achieved with photodiode array detection at 229 nm over the concentration range 1–25 μg/ml with range of recovery 99.8–101.3 % for DUL by the RP-HPLC method. Statistical analysis proved the method to be repeatable, specific, and accurate for estimation of DUL. It can be used as a stability-indicating method due to its effective separation of the drug from its degradation products

Conductivity of Metallic Si:B near the Metal-Insulator Transition: Comparison between Unstressed and Uniaxially Stressed Samples

The low-temperature dc conductivities of barely metallic samples of p-type Si:B are compared for a series of samples with different dopant concentrations, n, in the absence of stress (cubic symmetry), and for a single sample driven from the metallic into the insulating phase by uniaxial compression, S. For all values of temperature and stress, the conductivity of the stressed sample collapses onto a single universal scaling curve. The scaling fit indicates that the conductivity of si:B is proportional to the square-root of T in the critical range. Our data yield a critical conductivity exponent of 1.6, considerably larger than the value reported in earlier experiments where the transition was crossed by varying the dopant concentration. The larger exponent is based on data in a narrow range of stress near the critical value within which scaling holds. We show explicitly that the temperature dependences of the conductivity of stressed and unstressed Si:B are different, suggesting that a direct comparison of the critical behavior and critical exponents for stress- tuned and concentration-tuned transitions may not be warranted

The COMPLETE Nature of the Warm Dust Ring in Perseus

The Perseus molecular cloud complex is a ~30pc long chain of molecular clouds most well-known for the two star-forming clusters NGC1333 and IC348 and the well-studied outflow source in B5. However, when studied at mid- to far-infrared wavelengths the region is dominated by a ~10pc diameter shell of warm dust, likely generated by an HII region caused by the early B-star HD278942. Using a revised calibration technique the COMPLETE team has produced high-sensitivity temperature and column-density maps of the Perseus region from IRAS Sky Survey Atlas (ISSA) 60 and 100um data. In this paper, we combine the ISSA based dust-emission maps with other observations collected as part of the COMPLETE Survey, along with archival H-alpha and MSX observations. Molecular line observations from FCRAO and extinction maps constructed by applying the NICER method to the 2MASS catalog provide independent estimates of the ``true'' column-density of the shell. H-alpha emission in the region of the shell confirms that it is most likely an HII region located behind the cloud complex, and 8um data from MSX indicates that the shell may be interacting with the cloud. Finally, the two polarisation components previously seen towards background stars in the region can be explained by the association of the stronger component with the shell. If confirmed, this would be the first observation of a parsec-scale swept-up magnetic field.Comment: Accepted by ApJ. Figures have been compressed - full resolution version available at http://cfa-www.harvard.edu/COMPLETE/results.htm

Phase Transition in the Three-Dimensional ±J\pm J Ising Spin Glass

We have studied the three-dimensional Ising spin glass with a $\pm J$ distribution by Monte Carlo simulations. Using larger sizes and much better statistics than in earlier work, a finite size scaling analysis shows quite strong evidence for a finite transition temperature, $T_c$, with ordering below $T_c$. Our estimate of the transition temperature is rather lower than in earlier work, and the value of the correlation length exponent, $\nu$, is somewhat higher. Because there may be (unknown) corrections to finite size scaling, we do not completely rule out the possibility that $T_c = 0$ or that $T_c$ is finite but with no order below $T_c$. However, from our data, these possibilities seem less likely.Comment: Postscript file compressed using uufiles. The postscript file is also available by anonymous ftp at ftp://chopin.ucsc.edu/pub/sg3d.p

Analysis of Livelihood Structure of Pastoralists in Banni Grassland in Kachchh District of Gujarat in India

Banni grassland in Kachchh district of Gujarat in India is situated at 69024’ E longitude to 23042’ N latitude axis and spread in about 3847 sq km area. Banni region is a vast salt affected plain and experiences arid climate with average rainfall of 317mm received by southwest monsoon spread between June to September with high coefficient of Variation of 65%. Banni grassland is home to migratory pastoralists, generally called maldharies, for more than 500 years. Banni area comprises of 48 hamlets/villages organized into 19 Panchayats with a population of approximately 40,000 people. Maldharies are landless and depend upon village commons (Gauchars) for their livestock rearing. Banni buffaloes, kankrej cows, sheep, goat and camel are the domesticated animals. Breeding of kankrej bullocks and banni buffaloes for draught and milch purpose respectively was the traditional occupation and main source of income for maldharies. They breed and sell these animals to farmers in Gujarat and other parts of the country. Since late 1970s there has been a gradual shift in livestock population formerly dominated by kankrej cows to one now dominated by banni buffaloes. Change in vegetation pattern, especially invasion of Prosopis juliflora is attributed as one of the main reasons by farmers for this occupational shift. Feeding on P. juliflora pods over a period of time leads to dislocation and weakening of jaws in cows leading to their death. Mechanization of agriculture in Kachchh and other parts of Gujarat has led to reduction in use of bullocks for draught purpose. Consequently the demand for kankrej bullocks has also reduced drastically. On the other hand, banni buffaloes are tolerant to ill effects of feeding on P. juliflora. Hence, number of banni buffaloes has increased drastically since 1980s when compared to kankrej cows. Improved road connectivity of villages in banni area to Bhuj city and other towns and establishment of milk collection centers in the region has also played a vital role in growth and development of banni buffalo based dairy enterprise. These internal and external factors have led to change in occupational structure in banni region. Hence, documentation of changes in occupational structure and the driving factors behind such change is important. This research paper has the objective of analyzing the combination of various livelihood options available for pastoralist households of banni region