Einstein Observatory solid state spectrometer observations of M87 and the Virgo cluster

X-ray observations of the galaxy M87 and of a region in the Virgo cluster displaced 7 minutes from the center of M87 are presented. X-ray spectra are obtained at these two locations with the slid state spectrometer onboard the Einstein Observatory. Emission lines were observed in both locations, indicating the presence of heavy elements at abundances approximately solar (to within a factor of 2). A temperature gradient, T increases from approximately 1.4 keV at the position of M87 to T approximately 3.35 keV 7' away, was detected. There is lower temperature thermal emission at the center of M87 with T approximately 0.6 keV, consistent with models for cooling flows in this cluster. In addition to the thermal emission, a power law component in the spectrum of M87, was detected consistent with that observed by HEAO-1, indicating that this component probably originates in the galaxy itself. The presence of intracluster gas having density approximately .001 cu cm and temperature approximately 30 million K is indicated

What we can learn from magnetic Compton scattering : application to the determination of spin polarization

Studies of spin-resolved electron momentum densities involve the measurement of the so-called magnetic Compton profile. This is a one-dimensional projection of the electron momentum distribution of only those electrons that contribute to the spin moment of a sample. The technique is applicable to ferri- and ferromagnetic materials. The profile is obtained via the inelastic 'Compton' scattering of high energy X-rays. Since electrons originating from different atomic orbitals have specific momentum densities, it is often possible to determine the origin of the magnetism present. Typically, interpretation requires the use of electronic structure calculations using molecular orbital and band structure approaches. Here, we highlight the application of the technique to the determination of the Fermi level spin polarization, the knowledge of which is important to the development of novel spintronic materials

In what sense are dogs special? Canine cognition in comparative context

The great increase in the study of dog cognition in the current century has yielded insights into canine cognition in a variety of domains. In this review, we seek to place our enhanced understanding of canine cognition into context. We argue that in order to assess dog cognition, we need toregard dogs from three different perspectives: phylogenetically, as carnivoran and specifically a canid; ecologically, as social, cursorial hunters; and anthropogenically, as a domestic animal. A principled understanding of canine cognition should therefore involve comparing dogs’ cognition with that of other carnivorans, other social hunters, and other domestic animals. This paper contrasts dog cognition with what is known about cognition in species that fit into these three categories, with a particular emphasis on wolves, cats, spotted hyenas, chimpanzees, dolphins, horses, and pigeons. We cover sensory cognition, physical cognition, spatial cognition, social cognition, and self-awareness. Although the comparisons are in-complete, because of the limited range of studies of some of the other relevant species, we conclude that dog cognition is influenced by the membership of all three of these groups, and taking all three groups into account, dog cognition does not look exceptional

Plasma harmonics Lissajous measurements

June 17-21 200

Soil amendment with activated charcoal can reduce dieldrin uptake by cucumbers

Organochlorine pesticides (OCP) were once applied world wide but have been banned meanwhile in most countries because of their ecotoxicity, bioaccumulation and persistence. However, residues can still be present in soils even many years after applications have been stopped and taken up by crop plants. OCP accumulation from bound residues was found to be a particular problem in Cucurbitaceae plants. Two soil surveys performed in 2002 and 2005 in Switzerland revealed that OCP residues were taken up by cucumbers grown in soils that have been converted to organic production in the meantime. Even if legal tolerance values are not exceeded, this is a serious economic problem for the farmers affected by contaminated crops, because consumers of organically grown crops are only willing to pay the higher prices for these than for conventional products because they are particularly concerned about health and environmental quality and therefore expect pristine food. One approach to address the problem would be to increase the capacity of affected soils to bind OCP residues in order to prevent their uptake by the crops. In this study, we wanted to test the potential use of activated charcoal (AC) for this purpose. In addition, we wanted to assess the possibility of using OCP sorption in soil by Tenax® beads as a predictor for the phytoavailability of these compounds to cucumbers. We performed two pot experiments in which the cash crop cucumber (Cucumis sativus L.) was grown in soil with bound residues of dieldrin (70 µg/kg), pentachloroaniline (<0.01 µg/kg) and p,p-DDE. The soil was taken from a field under organic farming in which these residues were found in the 2005 survey. In the first experiment, cucumbers were grown for 12 to 13 weeks (until fruits were ripe) in soil into which AC had been mixed at concentrations of 200, 400, and 800 mg/kg and in untreated controls. In the second experiment, Tenax® beads were added to the soil and cucumbers, grown with and without AC amendment (800 mg/kg soil), were harvested after 4, 8, 10, 11, 12, and 13 weeks. Dieldrin was the only pesticide detected in the sampled cucumbers and extracted from soil by the Tenax beads. Dieldrin concentrations in the cucumbers were significantly reduced in the treatments with 400 and 800 mg/kg AC. Also significantly less dieldrin was sorbed by Tenax from the soil amended with 800 mg/kg AC than from the untreated control soil. More dieldrin was found to be sorbed by Tenax in the last 3-4 weeks of the experiment, particularly in the control soil, but this trend was not significant. The correlation between the amounts of Tenax-sorbed dieldrin and dieldrin accumulation in the cucumber fruits was significant in control soil and 800 mg/kg AC soil. Hence, Tenax appeared to be suited for the assessment of dieldrin solubility in soil and of phytoavailability to cucumbers

High-accuracy optical clock based on the octupole transition in 171Yb+

We experimentally investigate an optical frequency standard based on the 467 nm (642 THz) electric-octupole reference transition 2S1/2(F=0) -> F7/2(F=3) in a single trapped 171Yb+ ion. The extraordinary features of this transition result from the long natural lifetime and from the 4f136s2 configuration of the upper state. The electric quadrupole moment of the 2F7/2 state is measured as -0.041(5) e(a0)^2, where e is the elementary charge and a0 the Bohr radius. We also obtain information on the differential scalar and tensorial components of the static polarizability and of the probe light induced ac Stark shift of the octupole transition. With a real-time extrapolation scheme that eliminates this shift, the unperturbed transition frequency is realized with a fractional uncertainty of 7.1x10^(-17). The frequency is measured as 642 121 496 772 645.15(52) Hz.Comment: 5 pages, 4 figure

The effect of training on referrals to an outpatient adolescent sex offender treatment program

This study examines the effect of training on referrals to an outpatient adolescent sexual offender treatment program. Fifty-two juvenile court probation officers were trained to assess and identify adolescent sex offenders who met program referral criteria. Pre- and post-training tests were administered to measure the effect of training on a subject\u27s knowledge and understanding of sex offender assessment. Utilizing the Juvenile Sexual Offender Decision Criteria Form (University of Washington, 1986), referrals before and following training were evaluated to determine if they met program criteria. Analysis of the data suggested that training improved subjects\u27 knowledge and understanding, but not their ability to correctly identify adolescent sex offenders who met program referral criteria. Methodological problems, interagency differences, minimal treatment/referral options, and training inadequacies may explain the obtained results