Short-term memory trace mediated by termination kinetics of olfactory receptor.

Odorants activate receptors in the peripheral olfactory neurons, which sends information to higher brain centers where behavioral valence is determined. Movement and airflow continuously change what odor plumes an animal encounters and little is known about the effect one plume has on the detection of another. Using the simple Drosophila melanogaster larval model to study this relationship we identify an unexpected phenomenon: response to an attractant can be selectively blocked by previous exposure to some odorants that activates the same receptor. At a mechanistic level, we find that exposure to this type of odorant causes prolonged tonic responses from a receptor (Or42b), which can block subsequent detection of a strong activator of that same receptor. We identify naturally occurring odorants with prolonged tonic responses for other odorant receptors (Ors) as well, suggesting that termination-kinetics is a factor for olfactory coding mechanisms. This mechanism has implications for odor-coding in any system and for designing applications to modify odor-driven behaviors

Exploiting Spectral Leakage for Spectrogram Frequency Super-resolution

The spectrogram is a classical DSP tool used to view signals in both time and frequency. Unfortunately, the Heisenberg Uncertainty Principal limits our ability to use them for detecting and measuring narrowband signal modulation in wideband environments. On a spectrogram, instantaneous frequency can only be measured to the nearest bin without additional interpolation. This work presents a novel technique for extracting higher accuracy frequency estimates. Whereas most practitioners seek to suppress spectral leakage, we use mismatched windows to exploit such artifacts in order to produce super-resolved spectral displays. We present a derivation of our methodology and exhibit several interesting examples.Comment: Presented at the 2013 Asilomar Conference on Signals, Systems & Computer

Sea-Level Rise Practitioner Workshop Report: Leading Practices and Current Challenges

Seas are rising, and so is action in coastal communities to prepare. The uncertain timing of rising seas, difficulties evaluating long-term rise while facing more immediate causes of flooding such as typhoons and fluvial flooding, and simply the threat of permanent inundation of coastal zones settled for hundreds or thousands of years presents unprecedented challenges. As in all sectors impacted by anthropogenic climate change, working with others facing novel challenges to share progress and difficulties, collaborate regionally, and build competence and confidence in finding solutions can be invaluable

Periodic Optical Variability of Radio Detected Ultracool Dwarfs

A fraction of very low mass stars and brown dwarfs are known to be radio active, in some cases producing periodic pulses. Extensive studies of two such objects have also revealed optical periodic variability and the nature of this variability remains unclear. Here we report on multi-epoch optical photometric monitoring of six radio detected dwarfs, spanning the $\sim$M8 - L3.5 spectral range, conducted to investigate the ubiquity of periodic optical variability in radio detected ultracool dwarfs. This survey is the most sensitive ground-based study carried out to date in search of periodic optical variability from late-type dwarfs, where we obtained 250 hours of monitoring, delivering photometric precision as low as $\sim$0.15%. Five of the six targets exhibit clear periodicity, in all cases likely associated with the rotation period of the dwarf, with a marginal detection found for the sixth. Our data points to a likely association between radio and optical periodic variability in late-M/early-L dwarfs, although the underlying physical cause of this correlation remains unclear. In one case, we have multiple epochs of monitoring of the archetype of pulsing radio dwarfs, the M9 TVLM 513-46546, spanning a period of 5 years, which is sufficiently stable in phase to allow us to establish a period of 1.95958 $\pm$ 0.00005 hours. This phase stability may be associated with a large-scale stable magnetic field, further strengthening the correlation between radio activity and periodic optical variability. Finally, we find a tentative spin-orbit alignment of one component of the very low mass binary LP 349-25.Comment: Accepted to The Astrophysical Journal; 22 pages; 12 figure

Witness to Hope: Catholic Schools Respond to COVID-19

The twin uncertainties of the pandemic and the economic downturn have taken a toll on our Catholic schools. Yet reports across the country are that Catholic schools have been very successful in remote learning. Although there are well-documented efforts to define the values of Catholic schools, these values are not fully known and there is still not a well-crafted national value proposition for Catholic schools. As the context surrounding Catholic schools has changed, it has become imperative that Catholic schools coalesce around a new value proposition during uncertain times. What follows is an attempt by a group of dedicated Catholic school stakeholders determined to change the narrative. As our schools have pivoted to new forms of delivery and connections, this ad hoc group represents the same type of creative efforts to form a community. As a committee, we identified five themes of hope that can continue to guide the work and witness of our Catholic schools: prayer, partnership with families, personalization, persistence, and planning. In the following sections, we provide a rationale and overview of each theme. We also include relevant testimonials of diverse stakeholders to illuminate each theme and give voice to the hope across our school communities

Radio Observations of the Hubble Deep Field South region: I. Survey Description and Initial Results

This paper is the first of a series describing the results of the Australia Telescope Hubble Deep Field South (ATHDFS) radio survey. The survey was conducted at four wavelengths - 20, 11, 6, and 3 cm, over a 4-year period, and achieves an rms sensitivity of about 10 microJy at each wavelength. We describe the observations and data reduction processes, and present data on radio sources close to the centre of the HDF-S. We discuss in detail the properties of a subset of these sources. The sources include both starburst galaxies and galaxies powered by an active galactic nucleus, and range in redshift from 0.1 to 2.2. Some of them are characterised by unusually high radio-to-optical luminosities, presumably caused by dust extinction.Comment: Accepted by AJ. 32 pages, 4 tables, 3 figures. PDF with full-resolution figures is on http://www.atnf.csiro.au/people/rnorris/N197.pd

COVID Witness to Hope: Catholic Schools Respond to COVID-19

The twin uncertainties of the pandemic and the economic downturn have taken a toll on our Catholic schools. Yet reports across the country are that Catholic schools have been very successful in remote learning. Although there are well-documented efforts to define the values of Catholic schools, these values are not fully known and there is still not a well-crafted national value proposition for Catholic schools. As the context surrounding Catholic schools has changed, it has become imperative that Catholic schools coalesce around a new value proposition during uncertain times. What follows is an attempt by a group of dedicated Catholic school stakeholders determined to change the narrative. As our schools have pivoted to new forms of delivery and connections, this ad hoc group represents the same type of creative efforts to form a community. As a committee, we identified five themes of hope that can continue to guide the work and witness of our Catholic schools: prayer, partnership with families, personalization, persistence, and planning. In the following sections, we provide a rationale and overview of each theme. We also include relevant testimonials of diverse stakeholders to illuminate each theme and give voice to the hope across our school communities

Practitioner needs to adapt to Sea-Level Rise: Distilling information from global workshops

Climate-induced sea-level rise threatens the world’s coastal populations, critical infrastructure, and ecosystems. The science of sea-level rise (SLR) has developed to inform understanding of global climate mitigation and adaptation challenges, but there is much less engagement with practitioners to discern their climate services needs and support the development of adaptation planning and action on the ground. In addition, adaptation planning and implementation processes for SLR are relatively new and practitioners developing leading practices are seeking interaction with their peers and the SLR science community. To address these gaps, we co-produced online global workshops with sixty-nine practitioners from twenty-six countries. These workshops aimed to increase understanding of the state of SLR adaptation planning practice worldwide, gather information on practitioners' existing knowledge and service needs to advance their adaptation efforts, and facilitate exchange between practitioners engaged with coastal adaptation and the SLR science community. The workshops uncovered commonalities across contexts and identified consistent needs from scientists and other technical experts amongst the practitioner community. These needs include generating more localized SLR impact data, understanding of compound risk, creating data timelines for decision making, and developing clarity about uncertainties and probabilities. We also observed important differences between urban and rural locations and between places with different economic resources. To meet their needs, practitioners identified three crucial next steps: 1) Develop more online engagement opportunities, 2) Establish a global practitioner community of practice, and 3) Scale and improve the provision of climate services