Red Fraction Among Satellite Galaxies with Disk-like Light Profiles: Evidence for Inflow in the H I Disk

The relationships between color, characterized with respect to the g – r red sequence; stellar structure, as determined using the i-band Sérsic index; and group membership are explored using the Sloan Digital Sky Survey (SDSS). The new results place novel constraints on theories of galaxy evolution, despite the strong correlation between color and stellar structure. Observed correlations are of three independent types—those based on stellar structure, on the color of disk-like galaxies, and on the color of elliptical galaxies. Of particular note, the fraction of galaxies residing on the red sequence measured among galaxies with disk-like light profiles is enhanced for satellite galaxies compared to central galaxies. This fraction increases with group mass. When these new results are considered, theoretical treatments of galaxy evolution that adopt a gas accretion model centered on the hot galactic halo cannot consistently account for all observations of disk galaxies. The hypothesis is advanced that inflow within the extended H I disk prolongs star formation in satellite galaxies. When combined with partial ram pressure stripping (RPS) of this disk, this new scenario is consistent with the observations. This is demonstrated by applying an analytical model of RPS of the extended H I disk to the SDSS groups. These results motivate incorporating more complex modes of gas accretion into models of galaxy evolution, including cold mode accretion, an improved treatment of gas dynamics within disks, and disk stripping

The Crab pulsar and its pulsar-wind nebula in the optical and infrared

We investigate the emission mechanism and evolution of pulsars that are associated with supernova remnants. We used imaging techniques in both the optical and near infrared, using images with very good seeing (<0.6) to study the immediate surroundings of the Crab pulsar. In the case of the infrared, we took two data sets with a time window of 75 days, to check for variability in the inner part of the Crab nebula. We also measure the spectral indices of all these wisps, the nearby knot, and the interwisp medium, using our optical and infrared data. We then compared the observational results with the existing theoretical models. We report variability in the three nearby wisps located to the northwest of the pulsar and also in a nearby anvil wisp in terms of their structure, position, and emissivity within the time window of 75 days. All the wisps and the inner knot display red spectra with similar spectral indices. Similarly, the interwisp medium regions also show red spectra similar to those of the wisps. Also, based on archival HST data and our IR data, we find that the inner knot remains stationary for a time period of 13.5 years. The projected average velocity relative to the pulsar for this period is < 8 km/s. By comparing the spectral indices of the structures in the inner Crab with the current theoretical models, we find that the Del Zanna et al. (2006) model for the synchrotron emission fits our observations, although the spectral index is at the flatter end of their modelled spectra.Comment: 8 pages, 5 figure

Are Forensic Locksmiths Really Qualified to Testify as Experts in Cases of Insurance Fraud: An Examination of the Admissibility of Forensic Locksmith Opinions under Rule 702

This Note will argue that while forensic locksmiths may be qualified as experts under Rule 702, they should not necessarily be qualified to testify as to which key started a vehicle last. Part I of this note will discuss the basic history and case law which has established the requirements necessary to qualify an expert to testify under the Rule 702. In addition, Part I will discuss the recently enacted amendments to Rule 702 and how the amended Rule 702 has expanded the admissibility of expert witnesses. Part II of this note will discuss the generally accepted procedures of forensic locksmiths, including their qualifications under Rule 702. This discussion will include a brief history of the development of forensic locksmith analysis procedures. Part III will discuss the Key Pathway Analysis as an example of expert testimony that may not be admissible under Rule 702. The Key Pathway Analysis is a variation of traditionally recognized forensic locksmith procedures that has been repeatedly challenged in court for not following the guidelines established under Rule 702. Finally, Part IV will analyze problems that exist between the admissibility of expert testimony as to which key last started the vehicle and the potential for bad faith suits in wrongfully denying insurance claims

“Dollars Versus [Equality] Rights”: Money and the Limits on Distributive Justice

The social benefit challenges under the Charter’s equality guarantee offer insight into the Supreme Court of Canada’s approach to claims for distributive justice. In most of these cases, the financial costs to government of rights recognition play a role in the analysis. A survey of the outcomes of these cases and the “dollars” at stake reveals a “follow the money” pattern. In all cases in which the claim that the government regime creates an inequality was successful, the cost to the public purse of finding in favour of the equality claimant was characterized by the Court as low or inexpensive. All those cases in which the public cost of recognition was regarded as significantly high have failed, although some inexpensive claims have also failed. The correlation suggests that a minimal budgetary impact is a necessary, albeit not sufficient, condition for a successful social benefit challenge. Conversely, the correlation indicates that a significant budgetary impact poses a serious, if not insurmountable, barrier to success. The social benefit equality cases have also been the occasion of the Court’s elaboration of a doctrinal framework for factoring budgetary impacts into the adjudication of rights claims under the Charter. Much of the discussion in this regard has been on the question of at what stage of Charter analysis — the rights analysis, the section 1 analysis (and its subparts), and/or the remedy stage — the public cost of rights recognition should or should not be weighed against other factors. From an initial position of high principle — that governmental concerns about saving time and money should not trump rights — the jurisprudence has, over the past 30 years, reached a point at which the financial impact on government may play a significant role at all three stages of analysis, often curtailing a meaningful exploration of both the Charter values and the non-monetary regulatory concerns at stake. If the Charter equality guarantee is truly to be given substantive content, the n judges, lawyers and legal scholars need to work out a more coherent framework for taking account of budgetary impacts. an overview is provided of the sorts of considerations that need to be integrated into such a framework

The relation of maturity to total yield and seasonal distribution of yield in orchardgrass (Dactylis glomerata L.)

Orchardgrass (Dactylis glomerata L.) is grown in the United States from the Canadian border to the northern parts of the Gulf states (8). Although Tennessee is near the southern boundary of orchardgrass adaptation, it ranks seventh among the states with 265,000 acres. Yields of orchardgrass per acre tend to be lower near the southern boundary of its adaptation. Seasonal distribution of orchardgrass production is not uniform. In Tennessee the most rapid growth occurs in the spring and early summer. Rate of growth is slow in late summer and then increases in the fall. It would be desirable to have an orchardgrass which would produce more during late summer. Orchardgrass is often grown in association with perennial legumes such as alfalfa. Since the orchardgrass varieties grown in Tennessee mature earlier than these legumes, it is difficult to get maximum yields of high quality forage from orchardgrass-legume mixtures. A later maturing variety of orchardgrass is needed. The objective of this study was to determine the relationship in orchardgrass of maturity (time of anthesis) to total season production and seasonal distribution of production

Time-dependence in Relativistic Collisionless Shocks: Theory of the Variable "Wisps" in the Crab Nebula

We describe results from time-dependent numerical modeling of the collisionless reverse shock terminating the pulsar wind in the Crab Nebula. We treat the upstream relativistic wind as composed of ions and electron-positron plasma embedded in a toroidal magnetic field, flowing radially outward from the pulsar in a sector around the rotational equator. The relativistic cyclotron instability of the ion gyrational orbit downstream of the leading shock in the electron-positron pairs launches outward propagating magnetosonic waves. Because of the fresh supply of ions crossing the shock, this time-dependent process achieves a limit-cycle, in which the waves are launched with periodicity on the order of the ion Larmor time. Compressions in the magnetic field and pair density associated with these waves, as well as their propagation speed, semi-quantitatively reproduce the behavior of the wisp and ring features described in recent observations obtained using the Hubble Space Telescope and the Chandra X-Ray Observatory. By selecting the parameters of the ion orbits to fit the spatial separation of the wisps, we predict the period of time variability of the wisps that is consistent with the data. When coupled with a mechanism for non-thermal acceleration of the pairs, the compressions in the magnetic field and plasma density associated with the optical wisp structure naturally account for the location of X-ray features in the Crab. We also discuss the origin of the high energy ions and their acceleration in the equatorial current sheet of the pulsar wind.Comment: 13 pages, 4 figures, accepted to ApJ. High-resolution figures and mpeg movies available at http://astron.berkeley.edu/~anatoly/wisp