Lattice QCD Production on Commodity Clusters at Fermilab

We describe the construction and results to date of Fermilab's three Myrinet-networked lattice QCD production clusters (an 80-node dual Pentium III cluster, a 48-node dual Xeon cluster, and a 128-node dual Xeon cluster). We examine a number of aspects of performance of the MILC lattice QCD code running on these clusters.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 6 pages, LaTeX, 8 eps figures. PSN TUIT00

An observation of LHR noise with banded structure by the sounding rocket S29 Barium-GEOS

The measurement of electrostatic and obviously locally produced noise near the lower hybrid frequency made by the sounding rocket S29 Barium-GEOS is reported. The noise is strongly related to the spin of the rocket and reaches well below the local lower hybrid resonance frequency. Above the altitude of 300 km the noise shows banded structure roughly organized by the hydrogen cyclotron frequency. Simultaneously with the banded structure, a signal near the hydrogen cyclotron frequency is detected. This signal is also spin related. The characteristics of the noise suggest that it is locally generated by the rocket payload disturbing the plasma. If this interpretation is correct we expect plasma wave experiments on other spacecrafts, e.g., the space shuttle to observe similar phenomena

Rupture Directivity of Fluid-Induced Seismic Events

The hazards associated with induced seismicity have been hard to predict, especially when new technologies have been deployed, or when extant technologies have been deployed or up-scaled in new settings. The failure to adequately manage induced seismicity hazards has had major economic and environmental implications in many countries, where regulators have been forced to shut down industry operations. Recent examples include the Groningen gas field in the Netherlands, hydraulic fracturing of the Bowland shale in the UK, the CASTOR offshore UGS site in Spain, and the Pohang and Basel deep geothermal projects in South Korea and Switzerland respectively, with the latter one being seismically active several years after the injection well was shut-in. To better understand the complex rupture processes of induced earthquakes, we first compile the seismic waveforms of multiple seismic events induced by different fluid-injection operations, as hydraulic fracturing (HF) in shale gas wells and enhanced geothermal systems, wastewater disposal (WWD), and gas storage. We then implement the Empirical Green’s Function (EGF) method to measure for each analysed induced earthquake their rupture time and directivity, which complement other key source mechanism parameters of the same events already calculated, as moment magnitudes and focal mechanisms. The EGF method allows the measurement of the Source Time Function (STF) of a seismic event at each seismic station that recorded it, by deconvolving its seismic signal with the one from another seismic event of smaller magnitude but with very similar hypocentral location. This deconvolution between seismic waveforms from Target and EGF events allows a numerical removal of all factors that affect the recorded seismic waveform (like the earth structure, the near surface, and the instrument response) except for the event’s source itself, obtaining a STF for each target event at every seismic station. We then measure for each target event the rupture time at each station from the obtained STF, and invert the rupture times with respect to each station’s azimuth. We use the coefficient of determination (R2) of the inverted rupture time variation with azimuth to determine whether an induced earthquake had a predominant unilateral or bilateral rupture. In most cases, we observed a consistent self-similar scaling of the earthquake’s magnitude and mean rupture time, and a predominant unilateral rupture for higher magnitude events. In each case, we also examine whether the rupture directivity is driven by the local stress conditions, or by the fluid injection that induced them. Finally, we discuss the possibility of implementing the same methods to monitor the recently awarded CCS licenses in the UK Continental Shelf

Revised physical elements of the astrophysically important O9.5+O9.5V eclipsing binary system Y Cyg

Thanks to its long and rich observational history and rapid apsidal motion, the massive eclipsing binary Y Cyg represents one of the cornestones to critical tests of stellar evolution theory for massive stars. Yet, the determination of the basic physical properties is less accurate than it could be given the existing number of spectral and photometric observations. Our goal is to analyze all these data simultaneously with the new dedicated series of our own spectral and photometric observations from observatories widely separated in longitude. We obtained new series of UBV observations at three observatories separated in local time to obtain complete light curves of Y Cyg for its orbital period close to 3 days. This new photometry was reduced and carefully transformed to the standard UBV system using the HEC22 program. We also obtained new series of red spectra secured at two observatories and re-analyzed earlier obtained blue electronic spectra. Our analyses provide the most accurate so far published value of the apsidal period of 47.805 +/- 0.030 yrs and the following physical elements: M1=17.72+/-0.35$ Msun, M2=17.73+/-0.30 Msun, R1=5.785+/-0.091 Rsun, and R2=5.816+/-0.063 Rsun. The disentangling thus resulted in the masses, which are somewhat higher than all previous determinations and virtually the same for both stars, while the light curve implies a slighly higher radius and luminosity for star 2. The above empirical values imply the logarithm of the internal structure constant log k2 = -1.937. A comparison with Claret's stellar interior models implies an age close to 2 millions yrs for both stars. The claimed accuracy of modern element determination of 1-2 per cent seems still a bit too optimistic and obtaining new high-dispersion and high-resolution spectra is desirable.Comment: 13 pages; accepted for publication in Astronomy and Astrophysic

Trigger, an active release experiment that stimulated auroral particle precipitation and wave emissions

The experiment design, including a description of the diagnostic and chemical release payload, and the general results are given for an auroral process simulation experiment. A drastic increase of the field aligned charged particle flux was observed over the approximate energy range 10 eV to more than 300 keV, starting about 150 ms after the release and lasting about one second. The is evidence of a second particle burst, starting one second after the release and lasting for tens of seconds, and evidence for a periodic train of particle bursts occurring with a 7.7 second period from 40 to 130 seconds after the release. A transient electric field pulse of 200 mv/m appeared just before the particle flux increase started. Electrostatic wave emissions around 2 kHz, as well as a delayed perturbation of the E-region below the plasma cloud were also observed. Some of the particle observations are interpreted in terms of field aligned electrostatic acceleration a few hundred kilometers above the injected plasma cloud. It is suggested that the acceleration electric field was created by an instability driven by field aligned currents originating in the plasma cloud

CYP2C8 status of patients with malaria influences selection of Plasmodium falciparum pfmdr1 Alleles after Amodiaquine-Artesunate treatment

info:eu-repo/semantics/publishedVersio

Governance in Service Delivery in the Middle East and North Africa. World Development Report Background Paper

This paper examines the clientelistic equilibrium that remains prevalent in much of the Middle East and North Africa (MENA) region during the post-independence period, undermining service delivery and creating inequality in access. Political institutions and social practices that shape incentives for policymakers, service providers, and citizens create what can be called a potentially tenuous, “clientelistic equilibrium.” Service delivery is influenced by political institutions that allow for the capture of public jobs and service networks, and by social institutions that call upon individuals to respond more readily to members of their social networks than to others. The result is poor quality service delivery (e.g., absenteeism, insufficient effort), difficulties in access (e.g., need for bribes, connections), and inequalities in the provision of services