Sulphur-bearing species in the star forming region L1689N

We report observations of the expected main S-bearing species (SO, SO2 and H2S) in the low-mass star forming region L1689N. We obtained large scale (~300''x200'') maps of several transitions from these molecules with the goal to study the sulphur chemistry, i.e. how the relative abundances change in the different physical conditions found in L1689N. We identified eight interesting regions, where we carried out a quantitative comparative study: the molecular cloud (as reference position), five shocked regions caused by the interaction of the molecular outflows with the cloud, and the two protostars IRAS16293-2422 and 16293E. In the cloud we carefully computed the gas temperature and density by means of a non-LTE LVG code, while in other regions we used previous results. We hence derived the column density of SO, SO2 and H2S, together with SiO and H2CO - which were observed previously - and their relevant abundance ratios. We find that SiO is the molecule that shows the largest abundance variations in the shocked regions, whereas S-bearing molecules show more moderate variations. Remarkably, the region of the brightest SiO emission in L1689N is undetected in SO2, H2S and H2CO and only marginally detected in SO. In the other weaker SiO shocks, SO2 is enhanced with respect to SO. We propose a schema in which the different molecular ratios correspond to different ages of the shocks. Finally, we find that SO, SO2 and H2S have significant abundance jumps in the inner hot core of IRAS16293-2422 and discuss the implications of the measured abundances.Comment: Accepted 08/10/0

Sulphur chemistry and molecular shocks: the case of NGC1333-IRAS2

We present SO and SO2 observations in the region of the low mass protostar IRAS2/NGC1333. The East-West outflow originating from this source has been mapped in four transitions of both SO and SO2. In addition, CS observations published in the literature have been used. We compute the SO, SO2 and CS column densities and the physical conditions at several positions of the outflow using LTE and a non-LTE LVG approximations. The SO2/SO and CS/SO abundance ratios are compared with the theoretical predictions of a chemical model adapted to the physical conditions in the IRAS2 outflow. The SO2/SO abundance ratios are constant in the two lobes of the outflow whereas CS/SO is up to 6 times lower in the shocked gas of the East lobe than in the West one. The comparison with the chemical model allows us to constrain the age of the outflow produced by IRAS2 to >5e3yr. We find low densities and temperatures for the outflow of IRAS2 (70 K) from SO and SO2 emission probably because the two molecules trace the cooled entrained material. The East lobe of the outflow shows denser gas compared to the West lobe. We also discuss some constraints on the depleted form of sulphur

Season of birth, clinical manifestations and Dexamethasone Suppression Test in unipolar major depression

<p>Abstract</p> <p>Background</p> <p>Reports in the literature suggest that the season of birth might constitute a risk factor for the development of a major psychiatric disorder, possibly because of the effect environmental factors have during the second trimester of gestation. The aim of the current paper was to study the possible relationship of the season of birth and current clinical symptoms in unipolar major depression.</p> <p>Methods</p> <p>The study sample included 45 DSM-IV major depressive patients and 90 matched controls. The SCAN v. 2.0, Hamilton Depression Rating Scale (HDRS) and Hamilton Anxiety Scale (HAS) were used to assess symptomatology, and the 1 mg Dexamethasone Suppression Test (DST) was used to subcategorize patients.</p> <p>Results</p> <p>Depressed patients as a whole did not show differences in birth season from controls. However, those patients born during the spring manifested higher HDRS while those born during the summer manifested the lowest HAS scores. DST non-suppressors were almost exclusively (90%) likely to be born during autumn and winter. No effect from the season of birth was found concerning the current severity of suicidal ideation or attempts.</p> <p>Discussion</p> <p>The current study is the first in this area of research using modern and rigid diagnostic methodology and a biological marker (DST) to categorize patients. Its disadvantages are the lack of data concerning DST in controls and a relatively small size of patient sample. The results confirm the effect of seasonality of birth on patients suffering from specific types of depression.</p

The TESS science processing operations center

The Transiting Exoplanet Survey Satellite (TESS) will conduct a search for Earth's closest cousins starting in early 2018 and is expected to discover ∼1,000 small planets with R[subscript p] < 4 R[subscript ⊕] and measure the masses of at least 50 of these small worlds. The Science Processing Operations Center (SPOC) is being developed at NASA Ames Research Center based on the Kepler science pipeline and will generate calibrated pixels and light curves on the NASA Advanced Supercomputing Division's Pleiades supercomputer. The SPOC will also search for periodic transit events and generate validation products for the transit-like features in the light curves. All TESS SPOC data products will be archived to the Mikulski Archive for Space Telescopes (MAST)

Modeling Light Adaptation in Circadian Clock: Prediction of the Response That Stabilizes Entrainment

Periods of biological clocks are close to but often different from the rotation period of the earth. Thus, the clocks of organisms must be adjusted to synchronize with day-night cycles. The primary signal that adjusts the clocks is light. In Neurospora, light transiently up-regulates the expression of specific clock genes. This molecular response to light is called light adaptation. Does light adaptation occur in other organisms? Using published experimental data, we first estimated the time course of the up-regulation rate of gene expression by light. Intriguingly, the estimated up-regulation rate was transient during light period in mice as well as Neurospora. Next, we constructed a computational model to consider how light adaptation had an effect on the entrainment of circadian oscillation to 24-h light-dark cycles. We found that cellular oscillations are more likely to be destabilized without light adaption especially when light intensity is very high. From the present results, we predict that the instability of circadian oscillations under 24-h light-dark cycles can be experimentally observed if light adaptation is altered. We conclude that the functional consequence of light adaptation is to increase the adjustability to 24-h light-dark cycles and then adapt to fluctuating environments in nature

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

The early mathematical education of Ada Lovelace

Ada, Countess of Lovelace, is remembered for a paper published in 1843, which translated and considerably extended an article about the unbuilt Analytical Engine, a general-purpose computer designed by the mathematician and inventor Charles Babbage. Her substantial appendices, nearly twice the length of the original work, contain an account of the principles of the machine, along with a table often described as ‘the first computer program’. In this paper we look at Lovelace's education before 1840, which encompassed older traditions of practical geometry; newer textbooks influenced by continental approaches; wide reading; and a fascination with machinery. We also challenge judgements by Dorothy Stein and by Doron Swade of Lovelace's mathematical knowledge and skills before 1840, which have impacted later scholarly and popular discourse

Platelet 5-hydroxytryptamine uptake in affective disorders.

There is evidence that blood platelets accumulate, store and release 5-hydroxytryptamine (5-HT, serotonin) in a manner analagous to the central nervous system serotonergic synaptosome. The biogenic amine hypothsis of affective disorders states that depression is associated with a deficiency of brain 5-HT. Therefore, a study was carried out to compare the platelet 5-HT uptake characteristics of platelets from depressive patients and healthy control subjects. The rate of platelet 5-HT uptake was lower in depressive patients than in age and sex matched control subjects. There was no correlation between severity of illness and rate of 5-HT uptake, and the results for a group of patients tested both when depressed and again after recovery were similar on the two occasions. It is suggested that a low rate of 5-HT uptake is a trait contributing to a predisposition to depressive illness. A seasonal variation in 5-HT transport was observed in both controls and patients. The rate of 5-HT uptake was lowest in late spring and early summer, which is also the time of year of greatest incidence of depression and the peak in the suicide rate. Inhibition of 5-HT uptake was observed in depressed patients treated with either amitriptyline or zimelidine. The extent of inhibition of 5-HT transport was related to plasma drug concentrations, but did not correlate with clinical improvement. Prophylactic treatment with lithium increased the rate of platelet 5-HT uptake towards normal values in both unipolar and bipolar patients. The significance of these findings and their possible relationship to some other biochemical abnormalities observed in depressive patiente are discussed