A review of East Asian reports of aurorae and comets circa AD 775

Given that a strong 14C variation in AD 775 has recently been suggested to be due to the largest solar flare ever recorded in history, it is relevant to investigate whether celestial events observed around that time may have been aurorae, possibly even very strong aurorae, or otherwise related to the 14C variation (e.g. a suggested comet impact with Earth's atmosphere). We critically review several celestial observations from AD 757 to the end of the 770s, most of which were previously considered to be true, and in some cases, strong aurorae; we discuss in detail the East Asian records and their wording. We conclude that probably none among the events after AD 770 was actually an aurora, including the event in AD 776 Jan, which was misdated for AD 774 or 775; the observed white qi phenomenon that happened "above the moon" in the south-east was most probably a halo effect near the full moon - too late in any case to be related to the 14C variation in AD 774/5. There is another report of a similar (or identical) white qi phenomenon "above the moon", reported just before a comet observation and dated to AD 776 Jan; the reported comet observed by the Chinese was misdated to AD 776, but actually sighted in AD 767. Our critical review of East Asian reports of aurorae circa AD 775 shows some very likely true Chinese auroral displays observed and reported for AD 762; there were also several events prior to AD 771 that may have been aurorae but are questionable.Comment: 15 pages with 4 figure

A Prospective Phase II Study of Induction Carboplatin and Vinorelbine followed by Concomitant Topotecan and Accelerated Radiotherapy (ART) in Locally Advanced Non-small Cell Lung Cancer (NSCLC)

BackgroundSurvival of locally advanced/unresectable non-small cell lung cancer (NSCLC) has improved with the use of concurrent radiation and chemotherapy over the past decades, but local and distant failure remain high. In addition, a key limiting factor in combining chemotherapy with accelerated radiotherapy (ART) is severe esophagitis. We investigated the toxicity, response rate, and overall survival (OS) with induction carboplatin and vinorelbine followed by concomitant topotecan and ART in patients with locally advanced/unresectable NSCLC.MethodsIn this phase II trial, stage IIIA or IIIB NSCLC patients with a Karnofsky performance score >60 were eligible. Patients received induction carboplatin (area under the curve = 5.5) on days 1 and 22, and vinorelbine (25 mg/m2) on days 1, 8, 22, and 29. During the concurrent chemoradiation, patients received intravenous topotecan (0.5 mg/m2) on days 43 to 47, days 57 to 61, and days 71 to 75 before the morning radiotherapy (RT) fraction. RT was administered in an accelerated fashion at 2 Gy per fraction, twice daily for five consecutive days, every other week, to a cumulative dose of 60 Gy during a 5-week period.ResultsThirty-seven patients were accrued; of these, 35 were evaluable. Overall response rate was 71% (14% complete response, 57% partial response). Six of 35 (17%) patients had stable disease. Four (11%) patients progressed during treatment. At a median follow-up of 45 months for surviving patients, the median survival based on Kaplan–Meier estimates is 17.9 months. OS at 1, 2, and 3 years is 62%, 41%, and 33%, respectively. Actuarial 5-year OS is 21%. The median time to first relapse is 12.2 months (9.1–24.7 months). There were no cases of grade 3 or 4 esophagitis.ConclusionsThis combined-modality regimen yielded encouraging OS rates, with no severe esophagitis. Using four-dimensional RT treatment planning, we plan to further evaluate altered fractionation RT and chemotherapy for this group of patients

Infall and Outflow around the HH 212 protostellar system

HH 212 is a highly collimated jet discovered in H2 powered by a young Class 0 source, IRAS 05413-0104, in the L1630 cloud of Orion. We have mapped around it in 1.33 mm continuum, 12CO ($J=2-1$), 13CO ($J=2-1$), C18O ($J=2-1$), and SO ($J_K = 6_5-5_4$) emission at $\sim$ \arcs{2.5} resolution with the Submillimeter Array. A dust core is seen in the continuum around the source. A flattened envelope is seen in C18O around the source in the equator perpendicular to the jet axis, with its inner part seen in 13CO. The structure and kinematics of the envelope can be roughly reproduced by a simple edge-on disk model with both infall and rotation. In this model, the density of the disk is assumed to have a power-law index of $p=-1.5$ or -2, as found in other low-mass envelopes. The envelope seems dynamically infalling toward the source with slow rotation because the kinematics is found to be roughly consistent with a free fall toward the source plus a rotation of a constant specific angular momentum. A 12CO outflow is seen surrounding the H2 jet, with a narrow waist around the source. Jetlike structures are also seen in 12CO near the source aligned with the H2 jet at high velocities. The morphological relationship between the H2 jet and the 12CO outflow, and the kinematics of the 12CO outflow along the jet axis are both consistent with those seen in a jet-driven bow shock model. SO emission is seen around the source and the H2 knotty shocks in the south, tracing shocked emission around them.Comment: 17 pages, 11 figures, Accepted by the Ap

Demonstrating the performance of a real-time optical colorimetric sensing device for monitoring the marine environment

The research objective is to develop a cost-effective event detection sensing system to inform targeted sampling by traditional means and act as a decision support tool. The Optical Colorimetric Sensor (OCS) uses an array of LEDs to detect change in water coloration and alert to events. A prototype comprises the following features: an LED array light source, photodiode detectors, robust deployable design, GSM communication and antifouling measures. The system has been evaluated using laboratory and field measurements. The system is robust and deployable in the aquatic environment. The OCS shows potential to detect events in the environment due to a pollution

Host Galaxies of Luminous Type 2 Quasars at z ~ 0.5

We present deep Gemini GMOS optical spectroscopy of nine luminous quasars at redshifts z ~ 0.5, drawn from the SDSS type 2 quasar sample. Our targets were selected to have high intrinsic luminosities (M_V < -26 mag) as indicated by the [O III] 5007 A emission-line luminosity (L_[O III]). Our sample has a median black hole mass of ~ 10^8.8 M_sun inferred assuming the local M_BH-sigma_* relation and a median Eddington ratio of ~ 0.7, using stellar velocity dispersions sigma_* measured from the G band. We estimate the contamination of the stellar continuum from scattered quasar light based on the strength of broad H-beta, and provide an empirical calibration of the contamination as a function of L_[O III]; the scattered light fraction is ~ 30% of L_5100 for objects with L_[O III] = 10^9.5 L_sun. Population synthesis indicates that young post-starburst populations (< 0.1 Gyr) are prevalent in luminous type 2 quasars, in addition to a relatively old population (> 1 Gyr) which dominates the stellar mass. Broad emission complexes around He II 4686 A with luminosities up to 10^8.3 L_sun are unambiguously detected in three out of the nine targets, indicative of Wolf-Rayet populations. Population synthesis shows that ~ 5-Myr post-starburst populations contribute substantially to the luminosities (> 50% of L_5100) of all three objects with Wolf-Rayet detections. We find two objects with double cores and four with close companions. Our results may suggest that luminous type 2 quasars trace an early stage of galaxy interaction, perhaps responsible for both the quasar and the starburst activity.Comment: 20 pages, 13 figures, 7 tables; accepted to Ap

Dust Obscuration in Lyman Break Galaxies at z~4

Measuring star formation rates (SFRs) in high-z galaxies with their rest-frame ultraviolet (UV) continuum can be uncertain because of dust obscuration. Prior studies had used the submillimeter emission at 850 um to determine the intrinsic SFRs of rest-frame UV selected galaxies, but the results suffered from the low sensitivity and poor resolution (~15''). Here, we use ultradeep Very Large Array 1.4 GHz images with ~1''-2'' resolutions to measure the intrinsic SFRs. We perform stacking analyses in the radio images centered on ~3500 Lyman break galaxies (LBGs) at z~4 in the Great Observatories Origins Deep Survey-North and South fields selected with Hubble Space Telescope/Advanced Camera for Surveys data. The stacked radio flux is very low, 0.08+/-0.15 uJy, implying a mean SFR of 6+/-11 M/yr. This is comparable to the uncorrected mean UV SFRs of 5 M/yr, implying that the z~4 LBGs have little dust extinction. The low SFR and dust extinction support the previous results that z~4 LBGs are in general not submillimeter galaxies. We further show that there is no statistically significant excess of dust-hidden star-forming components within ~22 kpc from the LBGs.Comment: 6 pages, 3 figures, and 2 tables. Accepted to the Astrophysical Journal (ApJ

Development of a real-time, continuous, optical turbidity and colorimetric sensing device for the marine environment

Our aquatic heritage is a vital resource. Anthropogenic activities and industrialisation, however, have led to increased pressures on our natural waters, and consequently, careful management is required to ensure their sustainability and health for future generations. It is important to acknowledge that one can only manage what one can measure, and therefore, environmental sensing of riverine, estuarine and marine waters is becoming increasingly important to ensure that European directives such as the Water Framework Directive [1], the Bathing Water Directive [2] and the Marine Strategy Framework Directive [3] can be met. Traditional approaches have typically involved the intermittent collection of samples at the relevant monitoring location (grab sampling), the transportation of the samples to the laboratory, the analysis of samples using various lab-based analytical techniques and the evaluation of results. In relation to aquatic environmental monitoring, this approach is not always ideal due a number of factors, for example, (1) the possibility of missing events due to insufficient sampling frequencies, (2) the potential for sample contamination from the point of collection to the laboratory, and (3) the inherent lead time from sample collection to analytical results can be problematic with regards to delayed reaction protocols and cause traceability. This research seeks to resolve some of these outstanding issues through the development of a prototype, real-time, continuous turbidity and colorimetric sensing device for the marine environment. The new device seeks to improve upon our existing Multi-Channel Optical Device (MOD) [4], see Figure 1, in terms of robustness and data transmittance capabilities. Potential applications are the detection of harmful algal bloom (HABs), for example cyanobacteria, which are toxic to both humans and animal species. The sensing device uses an array of coloured LEDs to not only detect and quantify changes in turbidity but also to signal changes in colour intensity. Significant challenges exist to ensure the robustness of sensing systems in the aforementioned aquatic environments, and these issues vary in significance depending on the classification and remoteness of the monitoring location. Of these challenges, biofouling is one of the key limiting factors. One important aspect of this research is that it also incorporates the testing and assessment of recently developed biofouling mitigation techniques. This device is based on a generic platform, which will potentially result in a plug and play approach for various other sensor elements. Figure 1: Multi-Channel Optical device (MOD). Acknowledgements: This research is funded by a Beaufort Marine Research Award, which is carried out under the Sea Change Strategy and the Strategy for Science Technology and Innovation (2006-2013), with the support of the Marine Institute, funded under the Marine Research Sub-Programme of the National Development Plan 2007–2013. [1] EU website, Water Framework Directive, [on-line], http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2000:327:0001:0072:EN:PDF, Accessed 2012(November). [2] EU Website, Bathing Water Directive, [on-line], http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2006:064:0037:0051:EN:PDF, Accessed 2012(November). [3] EU Website, Marine Strategy Framework Directive, [on-line], http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2008:164:0019:0040:EN:PDF, Accessed 2012(November). [4] Lau, K. T., Kim, J., O’Sullivan, T. et al, "Sensing technologies for monitoring the marine environment", MARTECH Conference, Cadiz, Spain, (2011)

Monitoring the marine environment using a low-cost colorimetric optical sensor

Anthropogenic activities have led to increased stress on our marine and other aquatic environments. There is a pressing need to monitor, measure, understand and mitigate the causes of these pressures. This paper presents the development and preliminary testing of a low-cost colorimetric optical sensor to detect colour-linked events in the marine environment. Potential applications may include the detection of Harmful Algal Blooms (HAB), which due to the production of toxins have deleterious effects on marine ecosystems and can ultimately lead to human, fish, bird and mammal deaths. Preliminary results indicate the capability of the sensor to differentiate between the colour signatures of several environmental samples