A Frequency Comb calibrated Solar Atlas

The solar spectrum is a primary reference for the study of physical processes in stars and their variation during activity cycles. In Nov 2010 an experiment with a prototype of a Laser Frequency Comb (LFC) calibration system was performed with the HARPS spectrograph of the 3.6m ESO telescope at La Silla during which high signal-to-noise spectra of the Moon were obtained. We exploit those Echelle spectra to study the optical integrated solar spectrum . The DAOSPEC program is used to measure solar line positions through gaussian fitting in an automatic way. We first apply the LFC solar spectrum to characterize the CCDs of the HARPS spectrograph. The comparison of the LFC and Th-Ar calibrated spectra reveals S-type distortions on each order along the whole spectral range with an amplitude of +/-40 m/s. This confirms the pattern found by Wilken et al. (2010) on a single order and extends the detection of the distortions to the whole analyzed region revealing that the precise shape varies with wavelength. A new data reduction is implemented to deal with CCD pixel inequalities to obtain a wavelength corrected solar spectrum. By using this spectrum we provide a new LFC calibrated solar atlas with 400 line positions in the range of 476-530, and 175 lines in the 534-585 nm range. The new LFC atlas improves the accuracy of individual lines by a significant factor reaching a mean value of about 10 m/s. The LFC--based solar line wavelengths are essentially free of major instrumental effects and provide a reference for absolute solar line positions. We suggest that future LFC observations could be used to trace small radial velocity changes of the whole solar photospheric spectrum in connection with the solar cycle and for direct comparison with the predicted line positions of 3D radiative hydrodynamical models of the solar photosphere.Comment: Accept on the 15th of October 2013. 9 pages, 10 figures. ON-lINE data A&A 201

Laser frequency combs for astronomical observations

A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require measurements of Doppler velocity drifts of about 1 centimeter per second per year, and astronomical spectrographs have not yet been calibrated to this tolerance. We demonstrate the first use of a laser frequency comb for wavelength calibration of an astronomical telescope. Even with a simple analysis, absolute calibration is achieved with an equivalent Doppler precision of approximately 9 meters per second at about 1.5 micrometers - beyond state-of-the-art accuracy. We show that tracking complex, time-varying systematic effects in the spectrograph and detector system is a particular advantage of laser frequency comb calibration. This technique promises an effective means for modeling and removal of such systematic effects to the accuracy required by future experiments to see direct evidence of the universe's putative acceleration.Comment: Science, 5th September 2008. 18 pages, 7 figures (7 JPG files), including Supporting Online Material. Version with higher resolution figures available at http://astronomy.swin.edu.au/~mmurphy/pub.htm

Big data, method and the ethics of location : a case study of a hookup app for men who have sex with men

With the rise of geo-social media, location is emerging as a particularly sensitive data point for big data and digital media research. To explore this area, we reflect on our ethics for a study in which we analyze data generated via an app that facilitates public sex among men who have sex with men. The ethical sensitivities around location are further heightened in the context of research into such digital sexual cultures. Public sexual cultures involving men who have sex with men operate both in spaces “meant” for public sex (e.g., gay saunas and dark rooms) and spaces “not meant” for public sex (e.g., shopping centers and public toilets). The app in question facilitates this activity. We developed a web scraper that carefully collected selected data from the app and that data were then analyzed to help identify ethical issues. We used a mixture of content analysis using Python scripts, geovisualisation software and manual qualitative coding techniques. Our findings, which are methodological rather than theoretical in nature, center on the ethics associated with generating, processing, presenting, archiving and deleting big data in a context where harassment, imprisonment, physical harm and even death occur. We find a tension in normal standards of ethical conduct where humans are involved in research. We found that location came to the fore as a key - though not the only - actor requiring attention when considering ethics in a big data context

Observation and modeling of energetic particles at synchronous orbit on July 29, 1977

In the twelve hours following a worldwide storm, there was a series of at least four magnetospheric substorms, the last and largest of which exhibited an expansion phase onset at approximately 1200 UT. Data from six spacecraft in three general local time groupings (0300, 0700, and 1300 LT) were examined and vector magnetic field data and energetic electron and ion data from approximately 15 keV to 2 MeV were employed

Locative Media and Identity

The role of location-based social networks (LBSNs) on identity is a relatively unexplored area within the growing cannon of work on locative media. Following an exegesis of Giddens’s argument that narrative biographical accounts are critical in self-identity in the modern age and Foucault’s technologies of the self, this article positions LBSN, and in particular Foursquare, as a contributor to self-identity in users’ lives. A close reading of ethnographic and interview data from Foursquare users reveals that in the context of the presentation, maintenance, and reflection upon self-identity, LBSN use can play an integral role in the self-identity of its users. The contribution of LBSN to indicators of user lifestyle, the intentional sharing of particular locations, and user recollection of events and locations are the key features of how LBSNs provide conduits to self-identity. The degree of usage in everyday life is identified as critical in the positioning of LBSN as a key contributor to identity narratives. With the integration of LBSN features into more mainstream social media platforms, this contribution to self-identity in the social media age is resilient to the demise of stand-alone LBSN application

Everyday life and locative play: an exploration of Foursquare and playful engagements with space and place

Foursquare is a location-based social network (LBSN) that combines gaming elements with features conventionally associated with social networking sites (SNSs). Following two qualitative studies, this article sets out to explore what impact this overlaying of physical environments with play has on everyday life and experiences of space and place. Drawing on early understandings of play, alongside the flâneur and ‘phoneur’ as respective methods for conceptualizing play in the context of mobility and urbanity, this article examines whether the suggested division between play and ordinary life is challenged by Foursquare, and if so, how this reframing of play is experienced. Second, this article investigates what effect this LBSN has on mobility choices and spatial relationships. Finally, the novel concept of the ‘phoneur’ is posited as a way of understanding how pervasive play through LBSNs acts as a mediating influence on the experience of space and place

Avaliação do potencial de diferentes populações de Cleruchoides noackae (Hymenoptera: Mymaridae) multiplicadas em laboratório.

Resumo

"We can remember it for you": location, memory, and commodification in social networking sites

This article explores the spatial self through the performative aspects of location sharing and geotagging in the process of self-representation on social networking sites (SNSs). Based on the legacy of early experimentations with location-based technologies for social interaction, the article asserts that the representation of location in SNSs has more temporal than spatial attributes. The article explores the immediacy of networks and the different kinds of temporality encountered in SNSs to address the commodification of geotagged content uploaded on SNSs. Location-based data are valuable commodities bought and sold in the market. Therefore, the act of archiving memories on SNSs is commodified and performed within the predetermined functions and actions set within the SNSs’ interfaces. SNSs devise ways to keep users constantly interacting with the present moment in time and simultaneously create memories of the recent past while disclosing personal data that companies use for profit

Effect of rescue medication on seizure duration in non-institutionalized children with epilepsy

OBJECTIVES: Characterize the real-world management of and outcomes for children with epilepsy receiving rescue medication for prolonged acute convulsive seizures (PACS) in the community. METHODS: PERFECT-3 (Practices in Emergency and Rescue medication For Epilepsy managed with Community-administered Therapy 3) was a European, retrospective observational study. Eligible patients were non-institutionalized children with epilepsy aged 3–16 years who had experienced ≥1 PACS in the past year and had ≥1 currently prescribed PACS rescue medication. Investigators provided clinical assessments and parents/guardians completed questionnaires. Statistical tests were post hoc; p values are descriptive. RESULTS: At enrollment (N = 286), most patients had prescriptions for diazepam (69.2%) and/or midazolam (55.9%); some had two (26.6%) or three (2.4%) prescribed rescue medications. Most patients experienced PACS despite regular anti-epilepsy medication. According to parents, the average duration of their child’s seizures without rescue medication was <5 minutes in 35.7% of patients, 5–<20 minutes in 42.6%, and ≥20 minutes in 21.7% (n = 258); with rescue medication seizure duration was <5 minutes in 69.4% of patients, 5–<20 minutes in 25.6%, and ≥20 minutes in 5.0%. Rescue medication use was significantly associated with average seizures lasting <5 minutes (χ2 = 58.8; p < 0.0001). At the time of their most recent PACS, 58.5–67.8% of children reportedly received rescue medication within 5 minutes of seizure onset, and 85.4–94.1% within 10 minutes. CONCLUSION: This study provides the first real-world data that rescue medications administered in the community reduce the duration of PACS in children with epilepsy. Study limitations including potential recall bias are acknowledged