Evidence for glaciation in Elysium

It is suggested that certain landforms in the Elysium region of Mars provide strong evidence for glaciation. Landscapes related to subglacial volcanism suggest that ice was a primary agent in the development of Elysium

Profitable Prudence: The Case for Public Employer Defined Benefit Plans

Defined benefit plans remain the predominant form of retirement benefit for employees of state and local governments in the United States, which employ more than 10 percent of the nation’s workforce. This chapter describes the divergence between pensions in private industry, where the focus has shifted sharply toward defined contribution plans, and in the public sector, where defined benefit plans continue to dominate. One reason is that public employers have the ongoing responsibility of attracting and retaining a large workforce whose diversity is unmatched in private industry. We also offer an economic analysis of public plans, focusing on the value-added to state economies from investment returns which are often superior to those generated by defined contribution plans

Discipline Disproportionalities in Schools: The Relationship between Student Characteristics and School Disciplinary Outcomes

According to a 2014 report from the US Department of Education’s Office for Civil Rights, black students represent only 15% of students across the nation, but 35% of students suspended once are black, 44% of students suspended more than once are black, and 36% of expelled students are black. These disparate disciplinary aggregate outcomes, while troubling, do not provide as much information as policymakers need. In this study, we exploit three years of student-level discipline data from Arkansas to assess the extent to which black students or other minority students were more likely to receive certain types of punishments, even for the same infraction. In previous studies utilizing the same dataset, we find that, consistent with the recent reports on this topic, black students were punished more frequently; furthermore, we find that black students received slightly longer punishments than their white peers in the same school. The current study utilizes multinomial logit to assess the extent to which student demographics predict consequence type, even after controlling for infraction-level information and district characteristics. Black students, males, and low-income students (eligible for free- and reduced- lunch) were more likely to receive certain types of exclusionary consequences such as out-of-school suspension, expulsion, and referrals to Alternative Learning Environments relative to in-school-suspension

Disparate Use of Exclusionary Discipline: Evidence on Inequities in School Discipline from a U.S. State

There is much discussion in the United States about exclusionary discipline (suspensions and expulsions) in schools. According to a 2014 report from the US Department of Education’s Office for Civil Rights, Black students represent 15% of students, but 44% of students suspended more than once, and 36% of expelled students. This analysis uses seven years of individual infraction-level data from public schools in Arkansas. We examine whether disproportionalities exist within schools, or are instead, a function of the type of school attended. We find that marginalized students are more likely to receive exclusionary discipline, even after controlling for the nature and number of disciplinary referrals, but that most of the differences occur across schools rather than within schools

Do School Discipline Policies Treat Students Fairly? A Second Look at School Discipline Rate Disparities

Much work has documented that African-American students are more likely to receive expulsions and suspensions than their white peers. These disparities are troubling, but researchers and policymakers need more information to fully understand this issue. We use three years of student level discipline data for an entire state to assess whether non-white students are receiving different disciplinary consequences from their white peers in the same schools, for similar infractions and with similar behavioral history. We find that Black students received more severe (longer) punishments than their White peers in the state for the same types of infractions. These differences are due primarily to school-level differences, but even within the same schools, Black students receive slightly longer punishments than their White peers

Demonstration project in low-cost shoreline erosion control : final report to County Administrator, County of Accomack, Virginia

·1ow cost erosion control structures were installed at ten shoreline sites located in the lower Chesapeake Bay and on the Potomac and Rappahannock Rivers to further test the applicability of the perched beach concept under diverse littoral environments. The perched beach is achieved via installation of a low sill parallel to the shoreline. The objective of the sill is to provide a partial barrier behind which an elevated (perched) beach is accreted. When successful, ~he perched beach backshore and foreshore acts to reduce the frequency of direct wave attack against the fastland and thereby reducing the erosion rate. In this study, sills were used in conjunction with existing groins as well as alone. Some testing was performed on the use of a spur with existing groins as a device to prevent the formation of a downdrift erosion notch where the groin intersects the fastland. The sills were formed with a series of large PVC-coated nylon bags hydraulically filled with sand or with stone filled gabions. In one case compacted used auto tires were utilized as fill for a gabion. Evaluation of the response to the structures was based upon a series of surveyed beach profiles at each site and sequential photography. At each site the beach profiles were surveyed for several months prior to and following the installation of the various structures. Additional profiles were run adjacent to the treated areas. The structures were emplaced between late March and early June of 1978

Breaking and Seating of Rigid Pavements

Breaking and seating has been utilized extensively in Kentucky to rehabilitate portland cement concrete pavements. Experience over three or four years with this type of design and construction are summarized and reported. Breaking to a range of nominal fragments is evaluated. Evaluation of two roller weights for seating is reported. The use of dynamic deflections to evaluate the effectiveness of the breaking and seating process and to measure the appropriateness of the asphaltic concrete overlay

Hormonal control of rectal gland secretion in the European lesser spotted dogfish 'Scyliorhinus canicula'

1) Using the corrosion casting technique, which utilises a fast polymerising monomer resin, the vasculature of the rectal gland in Scyliorhinm canicula was studied using light and scanning electron microscopy. Possible control sites for altering blood flow through the rectal gland were identified. 2) A viable and reliable isolated perfused preparation of the rectal gland of S. canicula was developed by optimising flow rate, time of perfusion and viability of individual preparations. The combination of dibutryl cyclic adenosine monophosphate plus the potent phosphodiesterase inhibitor Isobutyl-methyl xanthine, was used as a test of viability for individual preparations. This combination potently stimulated chloride clearance rates from the isolated perfused rectal gland. 3) The isolated perfused preparation was then used to test a variety of hormones that could be involved in the control of rectal gland activity. The hormones, vasoactive intestinal peptide and urotensin II did not stimulate chloride clearance rates from the isolated perfused gland. However, the endogenous natriuretic peptide, C-type natriuretic peptide did stimulate chloride clearance rate from the perfused rectal gland in a dose dependant manner. Endogenous glucagon also stimulated chloride clearance rate. 4) Using cannulated fish, administration of angiotensin II and C-type natriuretic peptide in vivo, produced vasopressor and vasodepressor responses respectively and C-type natriuretic peptide inhibited the vasopressor action of angiotensin II when the two peptides were administered simultaneously. Administration of angiotensin II to the isolated perfused rectal gland produced a vasoconstrictor effect, increasing perfusion pressure. C-type natriuretic peptide did not produce any significant effect. A combination of the two peptides in vitro appeared to reduce the vasoconstrictor effect of angiotensin II. In addition this hormonal combination in vitro appeared to exert a synergistic effect increasing chloride clearance rates from the isolated perfused rectal gland. 5) The lack of a VIP stimulatory effect on the isolated perfused rectal gland in the present study is in agreement with previous reports. Using protein purification techniques including, gel-permeation, and reverse-phase high performance liquid chromatography an endogenous gut peptide was obtained that stimulated rectal gland activity in 5. canicula. This peptide was subsequently characterised as scyliorhinin II and it is proposed that the previously identified rectin and scyliorhinin II are the same peptide

Nondestructive Evaluation of Rigid Pavements Using Road Rater Deflections [1986]

Dynamic deflections have been used to determine in-place structural conditions of rigid pavements, based on modifications of principles and experience with the structural evaluation of flexible pavements. Details of the use of elastic layer theory to simulate deflection measurements associated with loadings for the Kentucky Road Rater are presented. Included is an illustration of the use of field deflection measurements to back calculate in-place moduli. The procedures are generally iterative and involve matching measured deflections with theoretical deflections. Elastic layer principles have been used to simulate deflections only at the mid slab position. Relationships regarding deflections at other locations on the slab currently involve empirical analyses. Evaluations involving the effects of pavement temperature, time of day, season, etc. are still empirical. In summary, major aspects of this report will be twofold. One will be related to procedures and principles applied to the use of deflections and layer elastic theory to estimate effective parameters representative of existing in-place pavement conditions. The second will be related to the application of deflection measurements and evaluation methodologies to determine appropriate recommendations of rehabilitation strategies and scheduling for rigid pavements

Nondestructive Evaluation of Rigid Pavements Using Road Rater Deflections [1984]

Road Rater deflections have been used to determine in-place structural conditions of rigid and composite pavements, based on modifications of principles and experience with the structural evaluation of flexible pavements. Details of the use of elastic layer theory to simulate deflection measurements associated with loadings for the Kentucky Road Rater are presented. Included is an illustration of the use of field deflection measurements to back calculate\u27 in-place moduli. The procedures are generally iterative and involve matching measured deflections with theoretical deflections. Elastic layer principles have been used to simulate deflections only at the midslab position. Relationships regarding deflections at other locations on the slab currently involve empirical analyses. Evaluations involving the effects of pavement temperature, time of day, season, etc. are still empirical. In summary, major aspects of this paper will be twofold. One will be related to procedures and principles applied to the use of deflections and layer elastic theory to estimate effective parameters representative of existing in-place pavement conditions. The second will be related to the application of deflection measurements and evaluation methodologies to determine appropriate recommendations of rehabilitation strategies and scheduling for rigid pavements