Recent earthquakes near Whittier, California

This paper deals with recent earthquakes noted in a small area near and to the south of Whittier, California, culminating in a shock at 8:46 a.m., P.S.T., on July 8, 1929, which just barely attained destructive intensity. Since the establishment of the Seismological Laboratory and the first group of auxiliary stations of the coordinated network in southern California, installed in 1926 and 1927, earthquakes emanating from this district have been registered as follows: a sharp shock at 11:14 a.m., P.S.T., on October 8, 1927; a swarm of small shocks on December 30 and 31, 1928; and a group in May, 1929. Also, following the main shock, many aftershocks occurred within a few hours, and since then shocks have continued to occur, at increasingly long and irregular intervals, down to the time of writing

Reputation Agent: Prompting Fair Reviews in Gig Markets

Our study presents a new tool, Reputation Agent, to promote fairer reviews from requesters (employers or customers) on gig markets. Unfair reviews, created when requesters consider factors outside of a worker's control, are known to plague gig workers and can result in lost job opportunities and even termination from the marketplace. Our tool leverages machine learning to implement an intelligent interface that: (1) uses deep learning to automatically detect when an individual has included unfair factors into her review (factors outside the worker's control per the policies of the market); and (2) prompts the individual to reconsider her review if she has incorporated unfair factors. To study the effectiveness of Reputation Agent, we conducted a controlled experiment over different gig markets. Our experiment illustrates that across markets, Reputation Agent, in contrast with traditional approaches, motivates requesters to review gig workers' performance more fairly. We discuss how tools that bring more transparency to employers about the policies of a gig market can help build empathy thus resulting in reasoned discussions around potential injustices towards workers generated by these interfaces. Our vision is that with tools that promote truth and transparency we can bring fairer treatment to gig workers.Comment: 12 pages, 5 figures, The Web Conference 2020, ACM WWW 202

Photon recycling in lead iodide perovskite solar cells.

Lead-halide perovskites have emerged as high-performance photovoltaic materials. We mapped the propagation of photogenerated luminescence and charges from a local photoexcitation spot in thin films of lead tri-iodide perovskites. We observed light emission at distances of ≥50 micrometers and found that the peak of the internal photon spectrum red-shifts from 765 to ≥800 nanometers. We used a lateral-contact solar cell with selective electron- and hole-collecting contacts and observed that charge extraction for photoexcitation >50 micrometers away from the contacts arose from repeated recycling between photons and electron-hole pairs. Thus, energy transport is not limited by diffusive charge transport but can occur over long distances through multiple absorption-diffusion-emission events. This process creates high excitation densities within the perovskite layer and allows high open-circuit voltages.The authors acknowledge financial support from the Engineering and Physical Sciences Research Council of the UK (EPSRC) and King Abdulaziz City for Science and Technology (KACST). L.M.P.O. and H.J.B. also thank the Nano doctoral training center (NanoDTC) for financial support. M.S., M.V. and J.M.R. thank the Winton programme for the physics of sustainability. M.C.Q would like to thank the Marie Curie Actions (FP7-PEOPLE-IEF2013) for funding. M.A.J. thanks Nyak Technology Ltd for PhD scholarship and B.E. acknowledges the Foundation for Fundamental Research on Matter (FOM), which is part of the Netherlands Organization for Scientific Research (NWO). F.D. acknowledges funding through a Herchel Smith Research Fellowship. We acknowledge Prof. Henning Sirringhaus, Prof. Neil Greenham, Prof. Ullrich Steiner, Dr. Erwin Reisner and Prof. Richard Phillips for providing support and access to their facilities.This is the author accepted manuscript. The final version is available from the American Association for the Advancement of Science via http://dx.doi.org/10.1126/science.aaf116

Linkage of the current ALS-resistance status with field history information of multiple fields infested with blackgrass (Alopecurus myosuroides Huds.) in southern Germany

The repetitive use of herbicides as major tool to control troublesome weeds in agriculture caused an increase in resistant weeds lately, especially when Integrated Weed Management principles were ingnored. In a case study approach we sampled blackgrass (Alopecurus myosuroides Huds.) in three distinctive locations for at least 3 years. Based on field infestation level, greenhouse biotests and laboratory analyses we grouped 23 fields as resitant (R), 28 fields as less sensitive (I) and 39 fields as sensitive (S) with regard to their ALS resistance status. Field history information was collected for 90 fields. Variables regarding the frequency of 1) summer crops, 2) winter cerals, 3) ploughing, 4) herbicide use, and 5) early versus late seeding were calculated. Fields with a higher frequency of summer crops, ploughing and later sowing dates in the crop rotation were less frequently grouped into R and I. No relationship was found between the number of modes of action used and the resistance status. Intensity of ALS-inhibitor use of grass herbicides played a role to distinguish resistant from sensitive fields. Our results suggest that cultural measures to bring the blackgrass population size to lower levels are more important than the selection by the herbicide.Zusammenhang des ALS-Resistenzstatus bei Ackerfuchsschwanz (Alopecurus myosuroides Huds.) mit den durchgeführten Bewirtschaftungsmaßnahmen auf mehreren Feldern in SüddeutschlandDer übermäßige Einsatz von Herbiziden als einzige Maßnahme zur Reduzierung von Problemunkräutern hat in den letzten jahren zu einer Zunahme resistenter Unkrautpopulationen geführt. Im Rahmen einer Fallstudie wurde daher Ackerfuchsschwanzsamen (Alopecurus myosuroides Huds.) an 3 Standorten über einen Zeitraum von mindetstens 3 Jahren beprobt. Basierend auf einer Befallseinschätzung im Feld, Gewächshaustests und Laboranalysen wurden 23 Felder als resistent (R), 28 Felder als vermindert sensitiv (I) und 39 Felder als sensitive Felder (S) gegenüber ALS-Inhibitoren klassifiziert. In Interviews mit den Landwirten konnten die Bewirtschaftungsmaßnahmen für diese 90 Felder erfragt werden. Aus diesen wurden Variablen, die den Anteil an 1) der Sommerungen in der Fruchtfolge, 2) des Wintergetreides in der Fruchtfolge, 3) den Pflugeinsatz, 4) den Herbizideinsatz sowie 5) die Saatzeitpunktewahl repräsentieren, generiert. Mit einer Zunahme an Sommerungen in der Fruchtfolge, einem erhöhten Pflugeinsatz sowie der häufigeren Wahl später Saatterminewar eine geringere Häufigkeit an resistenten Feldern zu beobachten. Dagegen wurde kein Zusammenhang zwischen der Anzahl der eingesetzten Wirkstoffklassen und dem Resistenzstatus gefunden. Signifikante Unterschiede beim Einsatz von ALS-Inhibitoren waren nur zwischen S und R erkennbar. Unsere Ergebnisse zeigen, dass ackerbauliche Maßnahmen eine stärkere Wirkung auf die Resistenzentwicklung haben, als die Häufigkeit and Art des Herbizid-Einsatzes

A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

A second study of blasting recorded in Southern California

Since the publication of our paper entitled "A Study of Blasting Recorded in Southern California" one further large blast has been set off in this region, and others moderate, to comparatively small, in magnitude. Two of these especially have afforded opportunity for further direct investigation. Others have yielded additional information

CO₂ Reduction to CO with 19% Efficiency in a Solar-Driven Gas Diffusion Electrode Flow Cell under Outdoor Solar Illumination

Solar-driven reduction of carbon dioxide represents a carbon-neutral pathway for the synthesis of fuels and chemicals. We report here results for solar-driven CO₂ reduction using a gas diffusion electrode (GDE) directly powered by a photovoltaic cell. A GaInP/GaInAs/Ge triple-junction photovoltaic cell was used to power a reverse-assembled gas diffusion electrode employing a Ag nanoparticle catalyst layer. The device had a solar-to-CO energy conversion efficiency of 19.1% under simulated AM 1.5G illumination at 1 Sun. The use of a reverse-assembled GDE prevented transition from a wetted to a flooded catalyst bed and allowed the device to operate stably for >150 h with no loss in efficiency. Outdoor measurements were performed under ambient solar illumination in Pasadena, California, resulting in a peak solar-to-CO efficiency of 18.7% with a CO production rate of 47 mg·cm⁻² per day and a diurnal-averaged solar-to-fuel conversion efficiency of 5.8%

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)