SuperSpec: On-chip spectrometer design, characterization, and performance

SuperSpec is an integrated, on-chip spectrometer for millimeter and sub-millimeter astronomy. SuperSpec is demonstrating a proof-of-principle multi-beam spectrometer on the sky at the Large Millimeter Telescope (LMT) in Mexico covering the 200 - 300 GHz frequency range with moderate resolution (R ~ 270 - 290). The dual-polarization, three-pixel instrument will consist of 6 SuperSpec spectrometer chips. We present the design and characterization of the devices being used in the first SuperSpec demonstration along with lab testing of the instrument performance

The Acute Phase Protein Ceruloplasmin as a Non-Invasive Marker of Pseudopregnancy, Pregnancy, and Pregnancy Loss in the Giant Panda

After ovulation, non-pregnant female giant pandas experience pseudopregnancy. During pseudopregnancy, non-pregnant females exhibit physiological and behavioral changes similar to pregnancy. Monitoring hormonal patterns that are usually different in pregnant mammals are not effective at determining pregnancy status in many animals that undergo pseudopregnancy, including the giant panda. Therefore, a physiological test to distinguish between pregnancy and pseudopregnancy in pandas has eluded scientists for decades. We examined other potential markers of pregnancy and found that activity of the acute phase protein ceruloplasmin increases in urine of giant pandas in response to pregnancy. Results indicate that in term pregnancies, levels of active urinary ceruloplasmin were elevated the first week of pregnancy and remain elevated until 20–24 days prior to parturition, while no increase was observed during the luteal phase in known pseudopregnancies. Active ceruloplasmin also increased during ultrasound-confirmed lost pregnancies; however, the pattern was different compared to term pregnancies, particularly during the late luteal phase. In four out of the five additional reproductive cycles included in the current study where females were bred but no birth occurred, active ceruloplasmin in urine increased during the luteal phase. Similar to the known lost pregnancies, the temporal pattern of change in urinary ceruloplasmin during the luteal phase deviated from the term pregnancies suggesting that these cycles may have also been lost pregnancies. Among giant pandas in captivity, it has been presumed that there is a high rate of pregnancy loss and our results are the first to provide evidence supporting this notion

SuperSpec: Development and Characterization of Kinetic Inductance Detector-Based On-Chip Spectrometer for Millimeter and Sub-Millimeter Observations

SuperSpec is an ultra-sensitive, moderate resolution (R ~ 300), on-chip spectrometer for mm and sub-mm wave observations of high redshift dusty galaxies. The device employs a filter-bank architecture in which Titanium Nitride kinetic inductance detectors (KIDs) are coupled to mm-wave resonant filters along a single microwave feedline. The detector's small size and and natural multiplexability compared to traditional grating spectrometers will enable future multi-object spectrographic measurements as well as high redshift line intensity mapping observations. This thesis presents the testing and characterization of these detectors, as well as preparations for on-sky deployment. Additionally, we present the progress on improvements to the SuperSpec filter bank technology utilizing thin film aluminum KIDs with a newly designed mm-wave filter bank structure

THE MARINE ENVIRONMENT AND ITS INFLUENCE ON SEAFARING AND MARITIME ROUTES IN THE PREHISTORIC AEGEAN

This article seeks to illustrate the decisive contribution of the sea environment and particularly the sea-surface circulation (which is determined by the circulation of sea currents and the winds) to the early growth of seafaring and maritime communications in the prehistoric Aegean. Given the means and techniques of navigation in that era, an attempt is made to reveal a dense network of sea routes which vessels could follow through the Aegean, in order to facilitate their trip. These sea routes are primarily based on environmental data and are confirmed concurrently by archaeological evidence and data of ancient sources. Therefore, it is evident that these sea routes played an important role not only in the early inhabitation of the Aegean islands and the foundation of coastal settlements throughout the Aegean area from the sixth millennium BC to the end of the third millennium BC, but in the development of the Aegean civilization during earlier prehistoric times as well

Perspectives on the production, and use, of rapid evidence in decision making during the COVID-19 pandemic: a qualitative study

Objectives: To describe perceptions of providing, and using rapid evidence, to support decision making by two national bodies (one public health policy and one front-line clinical practice) during the COVID-19 pandemic. Design: Descriptive qualitative study (March-August 2020): 25 semistructured interviews were conducted, transcribed verbatim and thematically analysed. Setting: Data were obtained as part of an evaluation of two Irish national projects; the Irish COVID-19 Evidence for General Practitioners project (General Practice (GP) project) which provided relevant evidence to address clinical questions posed by GPs; and the COVID-19 Evidence Synthesis Team (Health Policy project) which produced rapid evidence products at the request of the National Public Health Emergency Team. Participants: Purposive sample of 14 evidence providers (EPs: generated and disseminated rapid evidence) and 11 service ssers (SUs: GPs and policy-makers, who used the evidence). Main outcome measures: Participant perceptions. Results: The Policy Project comprised 27 EPs, producing 30 reports across 1432 person-work-days. The GP project comprised 10 members from 3 organisations, meeting 49 times and posting evidence-based answers to 126 questions. Four unique themes were generated. 'The Work' highlighted that a structured but flexible organisational approach to producing evidence was essential. Ensuring quality of evidence products was challenging, particularly in the context of absent or poor-quality evidence. 'The Use' highlighted that rapid evidence products were considered invaluable to decision making. Trust and credibility of EPs were key, however, communication difficulties were highlighted by SUs (eg, website functionality). 'The Team' emphasised that a highly skilled team, working collaboratively, is essential to meeting the substantial workload demands and tight turnaround time. 'The Future' highlighted that investing in resources, planning and embedding evidence synthesis support, is crucial to national emergency preparedness. Conclusions: Rapid evidence products were considered invaluable to decision making. The credibility of EPs, a close relationship with SUs and having a highly skilled and adaptable team to meet the workload demands were identified as key strengths that optimised the utilisation of rapid evidence. Ethics approval: Ethical approval was obtained from the National Research Ethics Committee for COVID-19-related Research, Ireland.</p

SuperSpec: the on-chip spectrometer: characterization of a full 300 channel filterbank (Conference Presentation)

SuperSpec is a new technology for millimeter and submillimeter spectroscopy. It is an on-chip spectrometer being developed for multi-object, moderate resolution (R = ~300), large bandwidth survey spectroscopy of high-redshift galaxies for the 1 mm atmospheric window. SuperSpec targets the CO ladder in the redshift range of z = 0 to 4, the [CII] 158 um line from z = 5 to 9, and the [NII] 205 um line from z = 4-7. All together these lines offer complete redshift coverage from z = 0 to 9. SuperSpec employs a novel architecture in which detectors are coupled to a series of resonant filters along a single microwave feedline instead of using dispersive optics. This construction allows for the creation of a full spectrometer occupying only 20 cm squared of silicon, a reduction in size of several orders of magnitude when compared to standard grating spectrometers. This small profile enables the production of future multi-object spectroscopic instruments required as the millimeter-wave spectroscopy field matures. SuperSpec uses a lens-coupled antenna to deliver astrophysical radiation to a microstrip transmission line. The radiation then propagates down this transmission line where upon proximity coupled half wavelength microstrip resonators pick off specific frequencies of radiation. Careful tuning of the proximity of the resonators to the feedline dials in the desired resolving power of the SuperSpec filterbank by tuning the coupling quality factor. The half wavelength resonators are then in turn coupled to the inductive meander of kinetic inductance detectors (KIDs), which serve as the power detectors for the SuperSpec filterbank. Each SuperSpec filter bank contains hundreds of titanium nitride TiN KIDs and the natural multiplexibility of these detectors allow for readout of the large numbers of required detectors. The unique coupling scheme employed by SuperSpec allows for the creation of incredibly low volume (2.6 cubic microns), high responsivity, TiN KIDs. Since responsivity is proportional to the inverse of quasiparticle-occupied volume, this allows SuperSpec to reach the low NEPs required by moderate resolution spectroscopy to be photon limited from the best ground-based observing sites. We will present the latest results from SuperSpec devices. In particular, detector NEPs, measured filter bank efficiency (including transmission line losses), and spectral profiles for a full ~ 300-channel filterbank. Finally, we will report on our system end to end efficiency and total system NEP