Concerning the Verity of the MMRD Relation for Novae

It has long been claimed that novae reaching the highest luminosity at the peak of their eruptions appear to fade the fastest from maximum light. The relationship between peak brightness and fade rate is known as the Maximum-Magnitude, Rate-of-Decline (MMRD) relation. Lightcurve parameters for the most recent sample of M31 recurrent novae are presented and used to buttress the case that the observed MMRD relation can be explained as a consequence of observational selection effects coupled with expectations from standard nova models.Comment: 5 pages; 1 figure; 1 table (figure data); abbreviated version accepted for publication in Research Notes of the AA

Economic Impact of Heavy Loads On the Highway Infrastructure

During the 1986 General Assembly the Extended-Weight Coal Haul Road System was created by the Kentucky State Legislature. This system was defined to include those highways where more than 50,000 tons of coal had been hauled during the previous year. Trucks hauling coal on the extended-weight system were authorized to exceed the normal weights limits through the payment of an annual decal fee. In efforts to identify the benefactors of the extended coal haul system legislation, this study has been conducted to identify the overall economic impact of hauling heavier total gross weights by coal truck on the highway infrastructure in Kentucky in 1996. In order to identify the overall economic impact of hauling heavier weights by coal truck an economic analysis had to be preformed. This economic analysis compared the monetary benefits achieved by all users for hauling heavier weights by coal truck to the additional expenses incurred by allowing heavier weights to be hauled on the highway infrastructure

Microfabricated structures with electrical isolation and interconnections

The invention is directed to a microfabricated device. The device includes a substrate that is etched to define mechanical structures at least some of which are anchored laterally to the remainder of the substrate. Electrical isolation at points where mechanical structures are attached to the substrate is provided by filled isolation trenches. Filled trenches may also be used to electrically isolate structure elements from each other at points where mechanical attachment of structure elements is desired. The performance of microelectromechanical devices is improved by 1) having a high-aspect-ratio between vertical and lateral dimensions of the mechanical elements, 2) integrating electronics on the same substrate as the mechanical elements, 3) good electrical isolation among mechanical elements and circuits except where electrical interconnection is desired

Generation of mechanical oscillation applicable to vibratory rate gyroscopes

To achieve a drive-axis oscillation with improved frequency and amplitude stability, additional feedback loops are used to adjust force-feedback loop parameters. An amplitude-control loop measures oscillation amplitude, compares this value to the desired level, and adjusts damping of the mechanical sense-element to grow or shrink oscillation amplitude as appropriate. A frequency-tuning loop measures the oscillation frequency, compares this value with a highly stable reference, and adjusts the gain in the force-feedback loop to keep the drive-axis oscillation frequency at the reference value. The combined topology simultaneously controls both amplitude and frequency. Advantages of the combined topology include improved stability, fast oscillation start-up, low power consumption, and excellent shock rejection

XTE J0111.2-7317 : a nebula-embedded X-ray binary in the SMC

The observed characteristics of the nebulosity surrounding the SMC High Mass X-ray Binary XTE J0111.2-7317 are examined in the context of three possible nebular types: SNR, bowshock and HII region. Observational evidence is presented which appears to support the interpretation that the nebulosity surrounding XTE J0111.2-7317 is an HII region. The source therefore appears to be a normal SMC Be X-ray binary (BeXRB) embedded in a locally enhanced ISM which it has photoionised to create an HII region. This is supported by observations of the X-ray outburst seen with BATSE and RXTE in 1998-1999. It exhibited characteristics typical of a giant or type II outburst in a BeXRB including large spin-up rates, Lx~10E38 erg/sq.cm-s, and a correlation between spin-up rate and pulsed flux. However, the temporal profile of the outburst was unusual, consisting of two similar intensity peaks, with the first peak of shorter duration than the second.Comment: Accepted for publication by MNRA

Repositioning the Boundaries between Public and Private Healthcare Providers in the English NHS

Background and Objectives: Neoliberal ‘reform’ has in many countries shifted services across the boundary between the public and private sector. This policy re-opens the question of what structural and managerial differences, if any, differences of ownership make to healthcare providers. This paper examines the relationships between ownership, organisational structure and managerial regime within an elaboration of Donabedian’s reasoning about organisational structures. Using new data from England it considers: 1. How do the internal managerial g regimes of differently owned healthcare providers differ, or not? 2. In what respects did any such differences arise from differences in ownership or for other reasons? Methods: An observational systematic qualitative comparison of differently-owned providers was the strongest feasible research design. We systematically compared a maximum-variety sample (by ownership) of community health services (CHS); out-of-hours primary care (OOH); hospital planned orthopaedics and ophthalmology providers (N=12 cases). The framework of comparison was the ownership theory mentioned above. Findings: The relationships between ownership (one one hand) and organisation structures and managerial regimes (on the other), differed at different organisational levels. Top-level governance structures diverged by organisational ownership and objectives among the case-study organisations. All the case-study organisations irrespective of ownership had hierarchical, bureaucratic structures and managerial regimes for coordinating everyday service production, but to differing extents. In doctor-owned organisations the doctors’, but not other occupations’, work was controlled and coordinated in a more-or-less democratic, self-governing ways. Conclusion: Ownership does make important differences to healthcare providers’ top-level governance structures and accountabilities; and to work coordination activity, but with different patterns at different organisational levels. These findings have implications for understanding the legitimacy, governance and accountability of healthcare organisations, the distribution and use of power within them, and system-wide policy interventions, for instance to improve care coordination; and for the correspondingly required foci of healthcare organisational research

Furfural induces reactive oxygen species accumulation and cellular damage in Saccharomyces cerevisiae

<p>Abstract</p> <p>Background</p> <p>Biofuels offer a viable alternative to petroleum-based fuel. However, current methods are not sufficient and the technology required in order to use lignocellulosic biomass as a fermentation substrate faces several challenges. One challenge is the need for a robust fermentative microorganism that can tolerate the inhibitors present during lignocellulosic fermentation. These inhibitors include the furan aldehyde, furfural, which is released as a byproduct of pentose dehydration during the weak acid pretreatment of lignocellulose. In order to survive in the presence of furfural, yeast cells need not only to reduce furfural to the less toxic furan methanol, but also to protect themselves and repair any damage caused by the furfural. Since furfural tolerance in yeast requires a functional pentose phosphate pathway (PPP), and the PPP is associated with reactive oxygen species (ROS) tolerance, we decided to investigate whether or not furfural induces ROS and its related cellular damage in yeast.</p> <p>Results</p> <p>We demonstrated that furfural induces the accumulation of ROS in <it>Saccharomyces cerevisiae</it>. In addition, furfural was shown to cause cellular damage that is consistent with ROS accumulation in cells which includes damage to mitochondria and vacuole membranes, the actin cytoskeleton and nuclear chromatin. The furfural-induced damage is less severe when yeast are grown in a furfural concentration (25 m<it>M</it>) that allows for eventual growth after an extended lag compared to a concentration of furfural (50 m<it>M</it>) that prevents growth.</p> <p>Conclusion</p> <p>These data suggest that when yeast cells encounter the inhibitor furfural, they not only need to reduce furfural into furan methanol but also to protect themselves from the cellular effects of furfural and repair any damage caused. The reduced cellular damage seen at 25 m<it>M </it>furfural compared to 50 m<it>M </it>furfural may be linked to the observation that at 25 m<it>M </it>furfural yeast were able to exit the furfural-induced lag phase and resume growth. Understanding the cellular effects of furfural will help direct future strain development to engineer strains capable of tolerating or remediating ROS and the effects of ROS.</p

The Borrego Mountain, California, earthquake of 9 April 1968: A preliminary report

The largest earthquake to hit California in more than 15 years occurred at 02:28:58.9 GCT on 9 April 1968 near Borrego Mountain, on the western edge of the Imperial Valley. The Seismological Laboratory at Pasadena has tentatively assigned the shock a magnitude of 6.5, an epicentral location of 33 ° 08.8' N, 116 ° 07.5' W, and a focal depth of 20 km. The earthquake was felt throughout most of southern California and adjacent areas, but the absence of severe damage and casualties was in large part due to the relatively undeveloped nature of the epicentral region. Indeed, it would have been difficult to pick a location in the southernmost part of the State more remote from centers of population