bluuebunny/crossref_metadata_2025 huggingface dataset:
A Putative Role for the Immunoproteasome in the Maintenance of Pluripotency in Human Embryonic Stem Cells
Authors: Atkinson Stuart P. , Collin Joseph , Irina Neganova , Anyfantis George , Kyung Bo Kim , Lako Majlinda , Armstrong Lyle
Published: April 2012

The function of the proteasome is essential for maintenance of cellular homeostasis, and in pluripotent stem cells, this has been extended to the removal of nascent proteins in a manner that restricts differentiation. In this study, we show enhanced expression of genes encoding subunits of the 20S proteasome in human embryonic stem cells (hESCs) coupled to their downregulation as the cells progress into differentiation. The decrease in expression is particularly marked for the alternative catalytic subunits of the 20S proteasome variant known as the immunoproteasome indicating the possibility of a hitherto unknown function for this proteasome variant in pluripotent cells. The immunoproteasome is normally associated with antigen-presenting cells where it provides peptides of an appropriate length for antibody generation; however, our data suggest that it may be involved in maintaining the pluripotency in hESCs. Selective inhibition of two immunoproteasome subunits (PSMB9 and PSMB8) results in downregulation of cell surface and transcriptional markers that characterize the pluripotent state, subtle cell accumulation in G1 at the expense of S-phase, and upregulation of various markers characterizing the differentiated primitive and definitive lineages arising from hESC. Our data also support a different function for each of these two subunits in hESC that may be linked to their selectivity in driving proteasome-mediated degradation of cell cycle regulatory components and/or differentiation inducing factors.
GABAB receptors do not internalize after baclofen treatment, possibly due to a lack of β‐arrestin association: Study with a real‐time visualizing assay
Authors: Sudo Yuka , Hojo Minoru , Ando Yuko , Takada Masafumi , Murata Hiroaki , Kurata Shinji , Nishida Noriyuki , Uezono Yasuhito
Published: April 2012

The mechanism of agonist‐induced GABAB receptor (GABABR) internalization is not well understood. To investigate this process, we focused on the interaction of GABABR with β‐arrestins, which are key proteins in the internalization of most of the G protein‐coupled receptors, and the agonist‐induced GABABR internalization and the interaction of GABABR with β‐arrestin1 and β‐arrestin2 were investigated in real time using GABABR and β‐arrestins both of which were fluorescent protein‐tagged. We then compared these profiles with those of μ‐opioid receptors (μOR), well‐studied receptors that associate and cointernalize with β‐arrestins. When stimulated by the specific GABABR agonist baclofen, GABABR composed of GABAB1aR (GB1aR) and fluorescent protein‐tagged GABAB2R‐Venus (GB2R‐V) formed functional GABABR; they elicited G protein‐activated inwardly rectifying potassium channels as well as nontagged GABABR. In cells coexpressing GB1aR, GB2R‐V, and β‐arrestin1‐Cerulean (βarr1‐C) or β‐arrestin2‐Cerulean (βarr2‐C), real‐time imaging studies showed that baclofen treatment neither internalized GB2R‐V nor mobilized βarr1‐C or βarr2‐C to the cell surface. This happened regardless of the presence of G protein‐coupled receptor kinase 4 (GRK4), which forms a complex with GABABR and causes GABABR desensitization. On the other hand, in cells coexpressing μOR‐Venus, GRK2, and βarr1‐C or βarr2‐C, the μOR molecule formed μOR/βarr1 or μOR/βarr2 complexes on the cell surface, which were then internalized into the cytoplasm in a time‐dependent manner. Fluorescence resonance energy transfer assay also indicated scarce association of GB2R‐V and β‐arrestins‐C with or without the stimulation of baclofen, while robust association of μOR‐V with β‐arrestins‐C was detected after μOR activation. These findings suggest that GABABRs failure to undergo agonist‐induced internalization results in part from its failure to interact with β‐arrestins. Synapse 66:759–769, 2012.© 2012 Wiley Periodicals, Inc.
Environmental argumentation as sociocultural activity
Authors: Oliveira Alandeom W. , Akerson Valarie L. , Oldfield Martha
Published: April 2012

While environmental argumentation has recently received much attention from science educators, little consideration has been given to how personal identities and social relationships can either support or constrain student argumentation. This study attends to this issue by examining environmental argumentation as a sociocultural activity (how students implicitly create identities and relationships through environmental warrants and claims). By integrating rhetorical and sociocultural analysis of oral discourse, we examine argumentation about environmental dilemmas (problematic scenarios involving animals and the environment). Although students set forth a variety of warrants (social, economic, contextual, biocentric, and expertise‐based), the dilemmas led to distinct forms of argumentation. One dilemma involving a pet iguana fostered non‐adversarial argumentation wherein students identified themselves as animal lovers and cooperative discussants. By contrast, the other two dilemmas (the hypothetical encounter with a fawn in the woods and the observation of classroom lights being unnecessarily left on) led to the unexpected emergence of sexual identities, combative disagreement, and conflict resolution on social rather than rational grounds. The main implication of this study is that it highlights the need for educators to pay closer attention to specific textual elements in the design of environmental dilemmas (types of prompts used, decision‐makers' identities, statements of intentionality and outcome, moral complexity, values of nature, and social representation or cultural images of animals) in order to foster an appropriate and productive sociocultural classroom context for rational and reasoned environmental argumentation to take place without the constraints of unexpected social complications. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 869–897, 2012
Prevalence of tetrahydrobiopterine (BH4)‐responsive alleles among Austrian patients with PAH deficiency: comprehensive results from molecular analysis in 147 patients
Authors: Sterl Elisabeth , Paul Karl , Paschke Eduard , Zschocke Johannes , Brunner‐Krainz Michaela , Windisch Eva , Konstantopoulou Vassiliki , Möslinger Dorothea , Karall Daniela , Scholl‐Bürgi Sabine , Sperl Wolfgang , Lagler Florian , Plecko Barbara
Published: April 2012

Phenylketonuria (PKU, MIM 261600) is an autosomal recessive disorder caused by mutations of the phenylalanine hydroxylase gene (PAH, GenBank U49897.1, RefSeq NM_000277). To date more than 560 variants of the PAH gene have been identified. In Europe there is regional distribution of specific mutations. Due to recent progress in chaperone therapy, the prevalence of BH4‐responsive alleles gained therapeutic importance. Here we report the mutational spectrum of PAH deficiency in 147 unrelated Austrian families. Overall mutation detection rate was 98.6 %. There was a total of 62 disease‐causing mutations, including five novel mutations IVS4 + 6T>A, p.H290Y, IVS8‐2A>G, p.A322V and p.I421S. The five most prevalent mutations found in patients were p.R408W, IVS12 + 1G>A, p.R261Q, p.R158Q and IVS2 + 5G>C. Neonatal phenylalanine levels before treatment were available in 114/147 patients. Prediction of BH4‐responsiveness in patients with full genotypes was exclusively made according to published data. Among the 133 patients needing dietary treatment, 28.4 % are expected to be BH4 “non‐responsive”, 4.5 % are highly likely BH4‐responsive, 35.8 % are probably BH4‐responsive while no interpretation was possible for 31.3 %. The mutation data reflect the population history of Austria and provide information on the likely proportion of Austrian PKU patients that may benefit from BH4‐therapy.
Multivariate decoding of fMRI data
Authors: Heinzle J. , Anders S. , Bode S. , Bogler C. , Chen Y. , Cichy R.M. , Hackmack K. , Kahnt T. , Kalberlah C. , Reverberi C. , Soon C.S. , Tusche A. , Weygandt M. , Haynes J.-D.
Published: April 2012

The advent of functional magnetic resonance imaging (fMRI) of brain function 20 years ago has provided a new methodology for non-in­vasive measurement of brain function that is now widely used in cognitive neurosci­ence. Traditionally, fMRI data has been an­alyzed looking for overall activity chang­es in brain regions in response to a stimu­lus or a cognitive task. Now, recent develop­ments have introduced more elaborate, con­tent-based analysis techniques. When mul­tivariate decoding is applied to the detailed patterning of regionally-specific fMRI signals, it can be used to assess the amount of infor­mation these encode about specific task-vari­ables. Here we provide an overview of sev­eral developments, spanning from applica­tions in cognitive neuroscience (perception, attention, reward, decision making, emotion­al communication) to methodology (informa­tion flow, surface-based searchlight decod­ing) and medical diagnostics.
Experimental models of spatial neglect
Authors: Wilke M. , Dechent P. , Schmidt-Samoa C.
Published: April 2012

Spatial neglect is a debilitating neuropsy­chological disorder that is characterized by an impaired or lost ability to explore the space contralateral to the lesion and to re­act to stimuli presented on this side. Lesion sites that have been implicated in spatial ne­glect form a widely distributed network con­sisting of a number of cortical (i.e., frontopa­rietal) and subcortical (i.e., thalamic) areas that are activated during attention and vi­suomotor tasks in healthy individuals. While detailed understanding of the brain circuits and mechanisms involved in spatial neglect is a prerequisite for the development of ef­fective therapies, this has proven to be dif­ficult in human patients because of the size and variability of lesion sites. Therefore, ex­perimental models where predefined brain regions can be systematically inactivated are of great advantage. Neglect models have been developed in nonhuman primates in whom it is possible to pharmacologically in­activate small brain regions and in humans by means of noninvasive stimulation/inacti­vation methods such as transcranial magnet­ic stimulation. In this article, we discuss theo­ries about the mechanisms of spatial neglect such as the hemispheric imbalance model and the supporting experimental evidence, with an emphasis on imaging experiments that have explored the effects of lesions on dynamic brain activity.
Comparison of neonatal and maternal outcomes associated with head‐pushing and head‐pulling methods for impacted fetal head extraction during cesarean delivery
Authors: Bastani Parvin , Pourabolghase Shabnam , Abbasalizadeh Fatemeh , Motvalli Leila
Published: April 2012

Objective

To compare the morbidity and mortality of 2 current techniques during cesarean delivery of an impacted fetal head.

Methods

In a comparative setting, 59 pregnant women with obstructed labor due to impacted fetal head were recruited. The patients were categorized into 2 groups according to method of extraction: the “push” group (n = 30) and the “pull” group (n = 29). Uterus relaxants were used before cesarean in all cases and the incision was higher and wider than routine. Maternal and neonatal morbidities were compared between the groups.

Results

Maternal complications in the push and pull groups were extension of the uterine incision (15 [50.0%] vs 5 [17.2%]); T or J incision (3 [10.0%] vs 4 [13.8%]); blood transfusion (3 [10.0%] vs 1 [3.4%]); wound infection (4 [13.3%] vs 1 [3.4%]); fever (16 [53.3%] vs 3 [10.3%]); and urinary tract infection (10 [33.3%] vs 0 [0.0%]). Incidences of extension of the uterine incision, fever, and urinary tract infection were significantly higher in the push group (P = 0.008).

Conclusion

Owing to a lower rate of abnormal incision and postpartum fever/infection with the pull method, this technique is preferable to the push method.
Ahab, American
Authors: McWilliams Susan
Published: April 2012

Despite common portrayals of Ahab as beyond the pale of common humanity, Melville offers much reason inMoby-Dickto regard Ahab as a reflection of ordinary American political life. Two of Ahab's most definitive characteristics—his isolation and his desire for domination—do not differentiate him from the other characters in the book but rather underscore how much he is like them. Among thePequod's crew in particular, those traits are the rule rather than the exception, a fact that helps to explain why the crew members are so quick to adopt Ahab's way of thinking: in large measure, it is already their own. Along these lines, looking at Ahab as a representative American man makes it possible to better understand Melville's true anxieties about the prospects for democratic flourishing in the United States.
War, Revenge, and Jewish Ethics: Rabbi Shaul Yisraeli's Essay on Kibiyeh Revisited
Authors: Eisen Robert
Published: April 2012

In 1953 the government of the newly founded state of Israel sent an elite army unit to attack the village of Kibiyeh, just across the Jordanian border. The attack was in reprisal for violence against Jewish villages on the Israeli side of the border. Since the end of the 1948 war, armed groups from Jordanian border towns had been infiltrating Israel and terrorizing its citizens, and in one such raid on the village of Yehud, a woman and her two young children were killed. The Israeli attack on Kibiyeh was in response to that incident. Kibiyeh was chosen as the target because the perpetrators of the violence in Yehud had apparently come from there. In the Kibiyeh raid, several dozen Arabs were killed, including women and children. Condemnation of the raid from the international community was swift. Opinion in Israel was mostly supportive of the operation, though a vocal minority opposed it.
Qui seront les premiers nés du baby-boom à risque de vulnérabilité financière à la retraite? Une comparaison Québec-Ontario
Authors: Légaré Jacques , Boucher Marie-Pier Bergeron
Published: April 2012

The oncoming retirement of baby boomers has governments worried. Will individual baby boomers demonstrate the ability to prepare financially for their retirement? Well-being in retirement depends largely on financial preparedness during working life. Those baby boomers who are the most vulnerable at the end of their working lives are more likely to become vulnerable during retirement. This study looks at the income of the first baby boomers, those born between 1946 and 1956, aged 50 to 60, according to the 2006 Canadian census. First we establish the socio-economic categories for which members are most financially vulnerable. Then, we estimate how many baby boomers are vulnerable and to what extent. This study’s preferred approach is an interprovincial comparison between Quebec and Ontario, used to analyze individual aspects of baby boomers’ financial positions.
Reexamining the relationship between design performance and the design process using reflection in action
Authors: Tang Hsien-Hui , Lee Yuying Y. , Chen Wenzhi
Published: April 2012

Reflective actions in collaborative design can potentially improve design performance and results. This paper quantitatively reexamines the relationships between reflective activities and design performance during the collaborative design process in terms of reflection in action. Twenty sets of protocol data were encoded by a modified version of Valkenburg and Dorst's coding scheme. Using statistical testing, the relationship between the design performance and the number of activities plus the transitions was examined. A significant statistical correlation was found between the percentage of mature framing (setting up of a desired goal with sufficient follow-ups) and the overall performance. These quantitative results verify the qualitative findings of the previous study.
Analysis of Trends and Emergency Activities Relating to Critical Victims of the Chuetsuoki Earthquake
Authors: Kondo Hisayoshi , Koido Yuichi , Hirose Yasuo , Kumagai Ken , Homma Masato , Henmi Hiroshi
Published: April 2012

Introduction: When a large-scale disaster occurs, it is necessary to use the available resources in a variety of sites and scenes as efficiently as possible. To conduct such operations efficiently, it is necessary to deploy limited resources to the places where they will be the most effective. In this study, emergency and medical response activities that occurred following the Chuetsuoki Earthquake in Japan were analyzed to assess the most efficient and effective activities.

Methods: Records of patient transports by emergency services relating to the Niigata Chuetsuoki Earthquake, a magnitude 6.8 earthquake that struck Japan on 16 July 2007 were analyzed, and interview surveys were conducted.

Results: The occurrence of serious injuries caused by this earthquake essentially was limited to the day the earthquake struck. A total of 682 patients were treated on the day of the quake, of which about 90 were hospitalized. Of the 17 patients whose conditions were life-threatening, three were rescued and transported to hospital by firefighters, three were transported by ambulance, and 11 were transported to hospital using private means. Sixteen people were subsequently transferred to other hospitals, six of these by helicopter. There was difficulty in meeting all of the requests for emergency services within 4 to 6 hours of the earthquake’s occurrence. Most transports of patients whose conditions were life-threatening were between hospitals rather than from the scene of the injury. Transfers of critical patients between hospitals were efficient early on, but this does not necessarily mean that inter-hospital transfers were given higher priority than treatment at emergency scenes.

Conclusion: During the acute emergency period following a disaster-causing event, it is difficult to meet all requests for emergency services. In such cases, it is necessary to conduct efficient activities that target critically injured patients. Since hospital transfers are matters of great urgency, it is necessary to consider assigning resource investment priority to hospital transfers during this acute period, when ambulance services may be insufficient to meet all needs. To deal with such disasters appropriately, it is necessary to ensure effective information exchange and close collaboration between ambulance services, firefighting organizations, disaster medical assistance teams, and medical institutions.
The Evaluation of Research Methods during Disaster Exercises: Applicability for Improving Disaster Health Management
Authors: Legemaate G.A. Guido , Burkle Frederick M , Bierens Joost J.L.M.
Published: April 2012

Introduction: The objective of this study was to investigate whether disaster exercises can be used as a proxy environment to evaluate potential research instruments designed to study the application of medical care management resources during a disaster.

Methods: During an 06 April 2005 Ministerial-level exercise in the Netherlands, three functional areas of patient contact were assessed: (1) Command and Control, through the application of an existing incident management system questionnaire; (2) patient flow and quality of patient distribution, through registration of data from prehospital casualty collection points, ambulances, and participating trauma centers (with inclusion of data in a flow chart); and (3) hospital coping capacity, through timed registration reports from participating trauma centers.

Results: The existing incident management system questionnaire used for evaluating Command and Control during a disaster exercise would benefit from minor adaptations and validation that could not be anticipated in the exercise planning stage. Patient flow and the quality of patient distribution could not be studied during the exercise because of inconsistencies among data, and lack of data from various collection points. Coping capacity was better measured by using 10-minute rather than one hour time intervals, but provided little information regarding bottlenecks in surge capacity.

Conclusion: Research instruments can be evaluated and improved when tested during a disaster exercise. Lack of data recovery hampers disaster research even in the artificial setting of a national disaster exercise. Providers at every level must be aware that proper data collection is essential to improve the quality of health care during a disaster, and that predisaster cooperation is crucial to validate patient outcomes. These problems must be addressed pre-exercise by stakeholders and decision-makers during planning, education, and training. If not, disaster exercises will not meet their full potential.
Time for Order in Chaos! A Health System Framework for Foreign Medical Teams in Earthquakes
Authors: Lind Karin , Gerdin Martin , Wladis Andreas , Westman Lina , von Schreeb Johan
Published: April 2012

The number of reported natural disasters is increasing, as is the number of foreign medical teams (FMTs) sent to provide relief. Studies show that FMTs are not coordinated, nor are they adapted to the medical needs of victims. Another key challenge to the response has been the lack of common terminologies, definitions, and frameworks for FMTs following disasters.

In this report, a conceptual health system framework that captures two essential components of health care response by FMTs after earthquakes is presented. This framework was developed using expert panels and personal experience, as well as an exhaustive literature review.

The framework can facilitate decisions for deployment of FMTs, as well as facilitate coordination in disaster-affected countries. It also can be an important tool for registering agencies that send FMTs to sudden onset disasters, and ultimately for improving disaster response.
Transitioning Mental Health & Psychosocial Support: From Short-Term Emergency to Sustainable Post-Disaster Development. Humanitarian Action Summit 2011
Authors: Patel P.P. , Russell J. , Allden K. , Betancourt T.S. , Bolton P. , Galappatti A. , Hijazi Z. , Johnson K. , Jones L. , Kadis L. , Leary K. , Weissbecker I. , Nakku J.
Published: April 2012

Introduction: The Working Group (WG) on Mental Health and Psychosocial Support participated in its second Humanitarian Action Summit in 2011. This year, the WG chose to focus on a new goal: reviewing practice related to transitioning mental health and psychosocial support programs from the emergency phase to long-term development. The Working Group's findings draw on a review of relevant literature as well as case examples.

Objectives: The objective of the Working Group was to identify factors that promote or hinder the long term sustainability of emergency mental health and psychosocial interventions in crisis and conflict, and to provide recommendations for transitioning such programs from relief to development.

Methods: The Working Group (WG) conducted a review of relevant literature and collected case examples based on experiences and observations of working group members in implementing mental and psychosocial programming in the field. The WG focused on reviewing literature on mental health and psychosocial programs and interventions that were established in conflict, disaster, protracted crisis settings, or transition from acute phase to development phase. The WG utilized case examples from programs in Lebanon, the Gaza Strip, Sierra Leone, Aceh (Indonesia), Sri Lanka, and New Orleans (United States).

Results: The WG identified five key thematic areas that should be addressed in order to successfully transition lasting and effective mental health and psychosocial programs from emergency settings to the development phase. The five areas identified were as follows: Government and Policy, Human Resources and Training, Programming and Services, Research and Monitoring, and Finance.

Conclusions: The group identified several recommendations for each thematic area, which were generated from key lessons learned by working group members through implementing mental health and psychosocial support programs in a variety of settings, some successfully sustained and some that were not.
Prehospital Analgesia in New South Wales, Australia
Authors: Bendall Jason C. , Simpson Paul M. , Middleton Paul M.
Published: April 2012

Introduction:With at least 20% of ambulance patients reporting pain of moderate to severe intensity, pain management has become a primary function of modern ambulance services. The objective of this study was to describe the use of intravenous morphine, inhaled methoxyflurane, and intranasal fentanyl when administered in the out-of-hospital setting by paramedics within a large Australian ambulance service.

Methods:A retrospective analysis was conducted using data from ambulance patient health care records (PHCR) for all cases from 01 July 2007 through 30 June 2008 in which an analgesic agent was administered (alone or in combination).

Results:During the study period, there were 97,705 patients ≤100 years of age who received intravenous (IV) morphine, intranasal (IN) fentanyl, or inhaled methoxyflurane, either alone or in combination. Single-agent analgesia was administered in 87% of cases. Methoxyflurane was the most common agent, being administered in almost 60% of cases. Females were less likely to receive an opiate compared to males (RR = 0.83, 95% CI, 0.82–0.84,p<0.0001). Pediatric patients were less likely to receive opiate analgesia compared to adults (RR = 0.65, 95% CI, 0.63–0.67,p<0.0001). The odds of opiate analgesia (compared to pediatric patients 0–15 years) were 1.47; 2.10; 2.56 for 16–39 years, 40–59 years, and ≥60 years, respectively. Pediatric patients were more likely to receive fentanyl than morphine (RR = 1.69, 95% CI, 1.64–1.74,p< 0.0001).

Conclusion:In this ambulance service, analgesia most often is provided through the use of a single agent. The majority of patients receive non-opioid analgesia with methoxyflurane, most likely because all levels of paramedics are authorized to administer that analgesic. Females and children are less likely to receive opiate-based analgesia than their male and adult counterparts, respectively. Paramedics appear to favor intranasal opiate delivery over intravenous delivery in children with acute pain.
Post-Traumatic Stress Disorder and Job Stress among Firefighters of Urban Japan
Authors: Saijo Yasuaki , Ueno Takeji , Hashimoto Yoshihiro
Published: April 2012

Introduction: Post-traumatic stress disorder (PTSD) is a common condition among Japanese firefighters. The purpose of this study was to clarify the relationship of PTSD scores to job stress, social support, and depressive stress among Japanese firefighters.

Methods: A total of 1,667 Japanese firefighters working for the local government completed a questionnaire that was used to gather information pertaining to age, gender, job type, job class, marital status, and smoking and drinking habits. Questionnaires from the Center for Epidemiologic Studies Depression Scale (CES-D), the Japanese version of the U.S. National Institute for Occupational Safety and Health (NIOSH) Generic Job Stress Questionnaire, and the IES-R were also used.

Results: After adjustment for age and gender, subjects in the PTSD-positive group had significantly higher scores for inter-group conflict, role ambiguity, and CES-D, as well as significantly lower scores for social support from their supervisors compared to those in the PTSD-negative group.

Conclusions: High inter-group conflict and role ambiguity, as well as low social support from supervisors and the presence of depressive symptoms, may influence the development of PTSD among Japanese firefighters.
PERSISTENT DEFICIT, GROWTH, AND INDETERMINACY
Authors: Minea Alexandru , Villieu Patrick
Published: April 2012

In this paper, we look for long-run and short-run effects of fiscal deficits on economic growth in an endogenous growth model with productive public spending that may be financed by public deficit and debt. The model shows a multiplicity of long-run balanced growth paths (a high-growth and a low-growth steady state) and a possible indeterminacy of the transition path, which may be consistent with the empirical literature, which exhibits strong nonlinear responses of economic growth to fiscal deficits. Starting from the high-growth steady state, a positive impulse in the deficit ratio exerts an adverse effect on economic growth in the long run, after an initial rise. Starting from the low-growth steady state, the situation may be radically undetermined, and the effect of fiscal deficit impulses is subjected to “optimistic” or “pessimistic” views on public-debt sustainability.
The Power of the Unexpected
Authors: Warner Brian
Published: April 2012

The history of astronomy has provided variable sources of unexpected kinds—from novae recorded in oriental archives, rapid radio, optical and high-energy changes in white dwarfs, neutron star and black hole binaries, to recent discoveries with satellites. A brief overview is given, as a prelude to a conference that anticipates a tidal wave of observations and discoveries to be made at all wavelengths during the next five to ten years.
Light Echoes of Transients and Variables
Authors: Rest Armin
Published: April 2012

Tycho Brahe's observations of a supernova in 1572 challenged the contemporaneous European view of the cosmos that the celestial realm was unchanging. 439 years later we have once again seen the light that Tycho saw, as some of the light from the 1572 supernova is reflected off dust and is only now reaching Earth. These light echoes, as well as ones detected from other transients and variables, give us a very rare opportunity in astronomy: direct observation of the cause (the supernova explosion) and the effect (the supernova remnant) of the same astronomical event. Furthermore, in some cases we can compare light echoes at different angles around a supernova remnant, and thus investigate possible asymmetry in the supernova explosion. In addition, in cases where the scattering dust is favorably positioned, the geometric distance to the SN remnant can be determined using polarization measurements. These techniques have been successfully applied to various transients in the last decade, and the talk gave an overview of the scientific results and techniques, with a particular focus on the challenges we will face in the current and upcoming wide-field time-domain surveys.
Gamma-Ray Waveband and Multi-Waveband Variability of Blazars
Authors: Ciprini Stefano
Published: April 2012

The Fermi Gamma-ray Space Telescope, as an all-sky survey and monitoring mission, is producing well-sampled gamma-ray light curves for dozens of blazars and other high-energy sources. We report highlights of gamma-ray variability properties, and outline multi-frequency observing campaigns that are targeted to new or known blazars which emit gamma rays.
Two Centuries of Observing R Coronæ Borealis
Authors: Clayton Geoffrey C.
Published: April 2012

R Coronæ Borealis was found to be variable in the year 1783, and was one of the first variable stars to be so identified. Its class, the R Coronæ Borealis (RCB) stars, are rare hydrogen-deficient carbon-rich supergiants. RCB stars undergo massive declines of up to 8 mag due to the formation of carbon dust at irregular intervals. The mechanism of dust formation around RCB stars is not well understood, but the dust is thought to form in or near the atmosphere of the star. Their rarity may stem from the fact that they are in an extremely rapid phase of the evolution, or are in an evolutionary phase that most stars do not undergo. Several evolutionary models have been suggested to account for the RCB stars, including a merger of two white dwarfs (WDs) or a final helium-shell flash (FF) in a PN central star. The large overabundance of 18O found in most of the RCB stars favours the WD merger model, while the presence of Li in the atmospheres of five RCB stars favours the FF one. In particular, the measured isotopic abundances imply that many, if not most, RCB stars are produced by WD mergers, which may be the low-mass counterparts of the more massive mergers thought to produce type Ia supernovæ. Understanding these enigmatic stars depends to a large extent on continuous monitoring to catch their irregular but rapid variations caused by dust formation, their variations due to stellar pulsations, and long-term changes that may occur over centuries. I will use observations of R Coronæ Borealis obtained over 200 years to demonstrate what kinds of monitoring are necessary for these and similar classes of variables.
Probing Magnetic Mysteries with Stellar Flares
Authors: Osten Rachel A.
Published: April 2012

Flares are a fact of life for stars in the cool half of the H-R diagram. The production of magnetic fields and the consequent dynamic interactions of field and plasma give rise to observational phenomena which span the electromagnetic spectrum. Stellar flares have an impact not only on the stellar atmosphere but also the stellar environment, which can include forming and already formed planets. This talk gave a brief review of our current state of understanding of stellar flares, highlighting some of the main unanswered questions by a panchromatic approach. It also emphasized commonalities between observations and analysis of stellar flares and other types of transient and variable sources.
Summary: A Very Timely Conference
Authors: Wyse Rosemary F. G.
Published: April 2012

The conference poster includes a very apt phrase that describes a primary motivation for this conference: Time discovers truth. This aphorism, attributed to Seneca, was certainly affirmed by the many exciting talks and discussions at this conference, in both formal and informal settings.
The CoRoT and Kepler Revolution in Stellar Variability Studies
Authors: Degroote Pieter , Debosscher Jonas
Published: April 2012

Space-based observations of variable stars have revolutionized the field of variability studies. Dedicated satellites such as the CoRoT and Kepler missions have duty cycles which are unachievable from the ground, and effectively solve many of the aliasing problems prevalent in ground-based observation campaigns. Moreover, the location above the Earth's atmosphere eliminates a major source of scatter prevalent in observations from the ground. These two major improvements in instrumentation have triggered significant increases in our knowledge of the stars, but in order to reap the full benefits they are also obliging the community to adopt more efficient techniques for handling, analysing and interpreting the vast amounts of new, high-precision data in an effective yet comprehensive manner. This workshop heard an outline of the history and development of asteroseismology, and descriptions of the two space missions (CoRoT and Kepler) which have been foremost in accelerating those recent developments. Informal discussions on numerous points peppered the proceedings, and involved the whole audience at times. The conclusions which the workshop reached have been distilled into a list of seven recommendations (Section 5) for the asteroseismology community to study and absorb. In fact, while addressing activities (such as stellar classification or analysing and modelling light curves) that could be regarded as specific to the community in question, the recommendations include advice on matters such as improving communication, incorporating trans-disciplinary knowledge and involving the non-scientific public that are broad enough to serve as guidelines for the astrophysical community at large.
Binarity and Stellar Evolution
Authors: Griffin R. E. M. , Rucinski Slavek
Published: April 2012

Models of stellar evolution constitute an extremely powerful, and for the most part apparently very successful, tool for understanding the progression of a star through its lifetime as a fairly compact entity of incandescent gas. That success has led to stellar evolution theory becoming a crutch when an observer is faced with objects whose provenance or current state are in some way puzzling, but how safe a crutch? The validity of the theory is best checked by examining binary systems whose component parameters have been determined with high precision, but it can be (and needs to be) honed through the many challenges which non-conformist single stars and triple systems also present. Unfortunately the lever of observational parameters to constrain or challenge stellar evolution theory is not as powerful as it could be, because not all determinations of stellar parameters for the same systems agree to within the precisions claimed by their respective authors. What are the sources of bias—the data, the instrument or the techniques? The workshop was invited to discuss particularly challenging cases, and to attempt to identify how and where progress might be pursued.
Workshop on Extreme Physics
Authors: Mundell Carole , Sullivan Mark
Published: April 2012

Never before has there been such a wealth of versatile ground- and space-based facilities with which to detect variable emission across the electromagnetic spectrum and beyond, to non-EM signals such as neutrinos and gravitational waves, to probe the most extreme phenomena in the Universe. The variable sky is already providing a wealth of new and surprising observations of phenomena such as GRBs, SNe and AGN that are pushing current theories beyond the state of the art. Multi-messenger follow-up will soon become de rigeur, and upcoming radio and optical all-sky transient surveys will revolutionise the study of the transient Universe. In addition to the technical and data challenges presented by such surveys, a major new challenge will be the interpretation of the wealth of available data and the identification of the underlying physics of new classes of variable (and potentially exotic) objects. Theoretical predictions will be vital for interpreting these future transient discoveries.

The goal of this workshop was to bring together theorists and observers in order to identify unexplored synergies across three main research areas of extreme physics: gamma-ray bursts, supernovæ and, more generically, relativistic jets. It aimed to discuss key outstanding questions in these rapidly moving fields, such as the composition and acceleration of GRB and AGN jets, GRB progenitors and central engines, the origin of the wide range of observed variability time-scales in GRB prompt and after-glow light curves and related cosmological applications, the physics of the newly-discovered ultra-luminous SN-like optical transients—as well as to speculate on what we might hope to discover with future technology.

The workshop absorbed two 90-minute sessions, selecting 3 main science topics (Relativistic Jets, GRBs and SNe) which it organised as structured discussions driven by a series of short but provocative questions. The final session featured a panel-led debate but with full audience participation.
Cepheids in Galactic Open Clusters: An All-sky Census
Authors: Anderson Richard I. , Eyer Laurent , Mowlavi Nami
Published: April 2012

We perform an all-sky search for classical (type I) Cepheids that are members of Galactic Open Clusters. Our approach is multi-dimensional, using all available spatial and kinematic parameters. The quantification of errors is crucial for this analysis, so care is taken to find adequate and realistic representations of parameter uncertainties. The data employed in the calculation are taken from published catalogues and the literature, supplemented by specific radial-velocity observations. Our work in progress is outlined here, and issues related to the inhomogeneity of cluster radii in the literature are discussed in some detail.
Aqueye and Iqueye, Very-High-Time-Resolution Photon-Counting Photometers
Authors: Barbieri Cesare , Naletto Giampiero , Zampieri Luca , Verroi Enrico , Gradari Serena , Collins Susan , Shearer Andy
Published: April 2012

We describe very high-time-resolution photometers capable of tagging the arrival time of each photon with a resolution and accuracy of few hundred picoseconds, for hours of continuous acquisition, and with a dynamic range of more than 6 orders of magnitude. The final goal is the conceptual definition of a “quantum” photometer for the E-ELT, capable of detecting and measuring second-order correlation effects in photon streams from celestial sources. Two prototype units have been built and operated, one for the Asiago 1.8-m telescope (AquEYE) and one for the 3.5-m NTT (IquEYE).Here we will present results obtained by IquEYE on the Crab Nebula pulsar in simultaneous radio observations with Jodrell Bank in December 2009.
Time-Resolved Spectroscopy with SDSS
Authors: Bickerton Steven , Badenes Carles , Hettinger Thomas , Beers Timothy , Huang Sonya
Published: April 2012

We present a brief technical outline of the newly-formed project, “Detection of Spectroscopic Differences over Time” (DS/DT). Our collaboration is using individual exposures from the SDSS spectroscopic archive to produce a uniformly-processed set of time-resolved spectra. Here we provide an overview of the properties and processing of the available data, and highlight the wide range of time base-lines present in the archive.
Improved Time-Series Photometry and Calibration Method for Non-Crowded Fields: MMT Megacam and HAT-South Experiences
Authors: Chang Seo-Won , Byun Yong-Ik , Kim Dae-Won
Published: April 2012

We present a new photometric reduction method for precise time-series photometry of non-crowded fields that does not need to involve relatively complicated and CPU intensive techniques such as point-spread-function (PSF) fitting or difference image analysis. This method, which combines multi-aperture index photometry and a spatio-temporal de-trending algorithm, gives much superior performance in data recovery and light-curve precision. In practice, the brutal filtering that is often applied to remove outlying data points can result in the loss of vital data, with seriously negative impacts on short-term variations such as flares. Our method utilizes nearly 100% of available data and reduces the rms scatter to several times smaller than that for archived light curves for brighter stars. We outline the details of our new method, and apply it to cases of sample data from the MMT survey of the M37 field, and the HAT-South survey.
Characterising the Dwarf Nova Population of the Catalina Real-time Transient Survey
Authors: de Budè Deanne , Woudt Patrick , Warner Brian
Published: April 2012

Results of a high-speed photometric study of dwarf novæ in the Catalina Real-time Transient Survey are given. A population of faint dwarf novæ near the orbital period minimum is detected. At the shortest periods there is a correlation between orbital period and outburst interval.
Inferring Rotation Periods of Young Stars from Synoptic Observations
Authors: Hartigan Patrick , Johns-Krull Christopher M. , Scowen Paul
Published: April 2012

Using known distributions for the periods, amplitudes and light-curve shapes of young stars, we examine how well one could measure periods of these objects in the upcoming era of large synoptic surveys. Surveys like the LSST should be able to recover accurate rotation periods for over 90% of targets of interest in regions near to massive-star formation. That information will usher in a new era in our understanding of how the angular momentum of a young star/disk system evolves with time.
Interstellar Scintillation as a Cosmological Probe: Prospects and Challenges
Authors: Koay J. Y. , Macquart J.-P. , Rickett B. J. , Bignall H. E. , Jauncey D. L. , Lovell J. E. J. , Reynolds C. , Pursimo T. , Kedziora-Chudczer L. , Ojha R.
Published: April 2012

The discovery that interstellar scintillation (ISS) is suppressed for compact radio sources at z ≳ 2 has enabled ISS surveys to be used as cosmological probes. We discuss briefly the potential and challenges involved in such an undertaking, based on a dual-frequency survey of ISS carried out to determine the origin of this redshift dependence.
An Extremely Luminous Outburst from a Relativistic Tidal Disruption Event
Authors: Levan A. J.
Published: April 2012

We present the discovery and monitoring observations of Swift 1644+57, a luminous outburst from the nucleus of a galaxy at z = 0.35. Precise astrometry ties the source to within a few hundred parsecs of the nucleus of its host, and suggests a link to the massive black hole that probably resides there. The high luminosity and rapid variability are strongly indicative of a beamed source. We suggest that this event is best explained by the tidal disruption of a passing star by the supermassive black hole, which simultaneously created a powerful panchromatic explosion. However, it has also been proposed that such events may be related to the core collapse of massive stars. Future observations of a sample of similar events, focussing on their locations within the hosts, should distinguish in a straightforward manner between the two proposals.
Solar System Science with Robotic Telescopes
Authors: Lister T. A.
Published: April 2012

An increasing number of sky surveys is already on-line or soon will be, leading to a large boost in the detection of Solar System objects of all types. For Near-Earth Objects (NEOs) that could potentially hit the Earth, timely follow-up is essential. I describe the development of an automated system which responds to new detections of NEOs from Pan-STARRS and automatically observes them with the LCOGT telescopes. I present results from the first few months of operation, and plans for the future with the 6-site, 40-telescope global LCOGT Network.
The NOAO Variable-Sky Project
Authors: Matheson T. , Blum R. , Jannuzi B. , Lauer T. , Norman D. , Olsen K. , Ridgway S. , Saha A. , Shaw R. , Walker A.
Published: April 2012

Modern time-domain surveys have demonstrated that finding variable objects is relatively straightforward. The problem now is one of selecting and following up discoveries. With even larger-scale surveys on the horizon, the magnitude of the problem will inevitably increase. One way to prepare for the coming deluge is to have realistic estimates of the numbers of potential detections so that resources can be developed to meet that need. To that end, astronomers at the National Optical Astronomy Observatory (NOAO) have begun a project to characterize the variable sky in terms of type of objects, distribution on the sky and range of variation.
Classification of ASKAP VAST Radio Light Curves
Authors: Rebbapragada Umaa , Lo Kitty , Wagstaff Kiri L. , Reed Colorado , Murphy Tara , Thompson David R.
Published: April 2012

The VAST survey is a wide-field survey that observes with unprecedented instrument sensitivity (0.5 mJy or lower) and repeat cadence (a goal of 5 seconds) that will enable novel scientific discoveries related to known and unknown classes of radio transients and variables. Given the unprecedented observing characteristics of VAST, it is important to estimate source classification performance, and determine best practices prior to the launch of ASKAP's BETA in 2012. The goal of this study is to identify light-curve characterization and classification algorithms that are best suited for archival VAST light-curve classification. We perform our experiments on light-curve simulations of eight source types and achieve best-case performance of approximately 90% accuracy. We note that classification performance is most influenced by light-curve characterization rather than classifier algorithm.
The Importance of Timing Metadata
Authors: Rots Arnold H.
Published: April 2012

We emphasize the crucial importance for authors and researchers to attach good and adequate metadata to their time-domain data. We provide pointers to existing and emerging standards, and provide guidance for labelling time in publications.