Oxygen Isotope Composition of Phosphate Along Vertical Weathering Profiles that Developed on Igneous Rocks: Testing Modern Analogues for Identifying Terrestrial Life in Ancient Paleosols

Life on Earth began in its early oceans before moving on to land. Determining the exact timing of an established biosphere on land, however, has been elusive, due largely to the lack of either fossil or chemical evidence on land deposits. Here I test a hypothesis that the activity of land biota can be recorded in the oxygen isotope composition of phosphate in weathering profiles developed on igneous parent rocks. Igneous rock contains phosphate (PO43-), which is readily utilized for biological activities during soil development. The oxygen in PO43- does not readily exchange its oxygen with ambient water. However, during intracellular pyrophosphate hydrolysis, the P-O bonds in PO43- break and reform repeatedly, resulting in exchange of oxygen with that of ambient water. Since the exchange occurs at low temperature and approaches equilibrium, the biologically processed PO43- will have much higher δ18O values than the ones from igneous sources. Thus, if an igneous weathering profile had been colonized by land biota, we shall expect to see an increase in the oxygen isotope composition of the bulk phosphate (δ18OPO4) from pristine un-weathered igneous rocks to the upper more weathered ones. To test this hypothesis, I targeted two recent weathering profiles: 1) a basalt weathering profile with continuous weathering since ~2 Ma near the town of Karamu, New Zealand, and 2) a basalt weathering profile with continuous weathering since ~4 Ma on Hainan Island in China. Samples were collected vertically across the profiles and then phosphate was extracted from them and precipitated as silver phosphate. Phosphate analyzed from the New Zealand profile shows a dramatic increase in its δ18O across the entire weathered section relative to fresh basalt. The δ18OPO4 of weathered samples range from ~19.4-24.9‰ while fresh unweathered parent basalt samples are between 7.4-8.6‰. The transition between the two is abrupt. The data from the Hainan profile are also consistent with the presence of biological P-recycling. The result of this study has an important implication for chronicling the early colonization of land by life. As long as there were biological activities on land the phosphate oxygen isotope composition will display a dramatic increase in δ18OPO4 up soil profiles developed on igneous parent rocks. Even if the upper section of an ancient paleosol is not preserved, which is often the case for paleosols, the dramatic increase in δ18OPO4 at the very beginning of signs of weathering, as shown by the Karamu section, increases the possibility of discerning early land biota activities in old weathering profiles developed on igneous rocks

Economic status of the public accountant

Within the experience of most all practicing Public Accountants, there comes to mind with pointed emphasis the fact that our functional utility is not fully understood by the general public in business life. A logical solution whereby this void will be reduced, consists of bringing the curve of Service to a closer ratio of co-ordination with the curve of Public Requirements. A thorough understanding, and therefore a freer use by the Public Accountant, of the scientific laws and principles of economics as related to industrial endeavor, would, in the writer\u27s opinion, have more potentiality for remedy of this void, than could be claimed for any of the popular methods now employed to accomplish the same result. Original item in Boxno. 040

Potential vorticity mixing by marginally unstable baroclinic disturbances

The weakly nonlinear dynamics of a baroclinic wave in a two-layer model near minimum critical shear is described in terms of a nonlinear critical layer problem which is completely integrable in the absence of dissipation. Sufficiently small amplitude supercritical inviscid disturbances are found to equilibrate to leading order, even though the absolute potential enstrophy of the lowest layer is always transient and transferred irreversibly to smaller and smaller scales. The inviscid equilibrium amplitude of the fundamental is found to be larger by a factor of 2 than the weakly dissipative value found by Pedlosky, implying that the limits t [RIGHTWARDS ARROW] ∞ and vanishing dissipation are not interchangeable. The fundamental equilibrates when the mixing in the lowest layer results in the streamwise homogenization of the coarse-grained potential vorticity. It is also noted that coarse-grain homogenization can be established on faster time scales than the fine-grain versions discussed by Rhines and Young. With weak or vanishing supercriticality or larger initial disturbance amplitudes, the fundamental may either equilibrate or oscillate periodically, depending on the form and strength of the initial disturbance. In the oscillating case, the baroclinic vortex reversibly wraps up and un-wraps and there is no tendency to mix potential vorticity. Finally, the possibility of further instabilities similar to those discussed by Killworth and McIntyre, and Haynes for the Rossby wave critical layer problem is also noted

A Model Part-Time Bachelor\u27s Degree Program for Adults at California Public Research Institutions

The purpose of this study was to assess the opportunities available to adults for continuing their education part-time to complete a Bachelor\u27s degree and to assess a California research institution\u27s perception of part-time study. Adult student enrollments in postsecondary education have increased 114 percent between 1970 and 1985. Part-time student enrollments rose nearly 87 percent during the same time frame and part-time students now comprise approximately 42 percent of the enrollment in postsecondary education. California research institutions are typically still providing services for the traditional day-time student. There is a persistent resistance to change by faculty. Changing the way the institution provides services to adults attending part-time and introducing new teaching methods requires campus and University of California systemwide approvals. These approvals are highly capital intensive and their procedures time consuming. Thus, responding to rapidly changing social and economic conditions is difficult. A survey of part-time students at a research institution provided data for descriptive statistics. Interviews with part-time degree administrators and faculty at research institutions provided their viewpoints regarding part-time students. This qualitative study utilized the interpretive paradigm. Data clearly indicated the need for development of part-time education at California public research institutions that would provide an opportunity for academic, personal and social growth. Working adults see themselves more as consumers of educational products than do most traditional college students. Their educational objectives are often more focused and they expect specific results from their educational investment (e.g., job advancement, career change). Public research institutions need to embrace two goals: First, change the current traditional approach by leaders of California public research institutions to create an educational environment responsive to the diverse characteristics, conditions and needs of adults. Second, increase access for the hundreds of adults seeking part-time study to obtain a Bachelor\u27s degree at a California public research institution. An important component of leadership responsibility is to constantly re-evaluate assumptions based on routine practice, which are comfortable, and to strive to implement effective new ways of educating all students--youth, young adults and older adults. A model part-time degree program was developed to provide guidance for higher education administrators

Internal solitary waves in the ocean: Analysis using the periodic, inverse scattering transform

The periodic, inverse scattering transform (PIST) is a powerful analytical tool in the theory of integrable, nonlinear evolution equations. Osborne pioneered the use of the PIST in the analysis of data form inherently nonlinear physical processes. In particular, Osborne's so-called nonlinear Fourier analysis has been successfully used in the study of waves whose dynamics are (to a good approximation) governed by the Korteweg--de Vries equation. In this paper, the mathematical details and a new application of the PIST are discussed. The numerical aspects of and difficulties in obtaining the nonlinear Fourier (i.e., PIST) spectrum of a physical data set are also addressed. In particular, an improved bracketing of the "spectral eigenvalues" (i.e., the +/-1 crossings of the Floquet discriminant) and a new root-finding algorithm for computing the latter are proposed. Finally, it is shown how the PIST can be used to gain insightful information about the phenomenon of soliton-induced acoustic resonances, by computing the nonlinear Fourier spectrum of a data set from a simulation of internal solitary wave generation and propagation in the Yellow Sea.Comment: 10 pages, 4 figures (6 images); v2: corrected a few minor mistakes and typos, version accepted for publication in Math. Comput. Simu

Evaluation of alternative discrete-event simulation experimental methods

The aim of the research was to assist non-experts produce meaningful, non-terminating discrete event simulations studies. The exemplar used was manufacturing applications, in particular sequential production lines. The thesis addressed the selection of methods for introducing randomness, setting the length of individual simulation runs, and determining the conditions for starting measurements". Received wisdom" in these aspects of simulation experimentation was not accepted.The research made use of a Markov Chain queuing model and statistica analysis of exhaustive computer-based experimentation using test models. A specific production-line model drawn from the motor industry was used as a point of reference. A distinctive,quality control like, process of facilitating the controlled introduction of "representative randomness" from a pseudo random-number generator was developed, rather than relying on a generator's a priori performance in standard statistical tests of randomness. This approach proved to be effective and practical. Other results included: The distortion in measurements due to the initial conditions of a simulation run of a queue was only corrected by a lengthy run and not by discarding early results. Simulation experiments of the same queue, demonstrated that a single long run gave greater accuracy than having multiple runs. The choice of random number generator is less important than the choice of seed. Notably, RANDU (a "discredited"MLCG) with careful seed selection was able to outperform in tests both real random numbers, and other MLCGs if their seed were chosen randomly,99.8% of the time. Similar results were obtained for Mersenne Twister and Descriptive Sampling.Descriptive Samnpling was found to provide the best samples and was less susceptible to errorsin the forecast of the required sample size. A method of determining the run length of the simulation that would ensure the run was representative of the true condifions was proposed. An interactive computer program was created to assist in the calculation of the run length of a simulation and determine seeds so as to obtain" highly representative" samples, demonstrating the facility required in simulation software to support theses elected methods

Documenting occupational sorting by gender in the UK across three cohorts: does a grand convergence rely on societal movements?

We consider the extent to which temporal shifts have been responsible for an increased tendency for females to sort into traditionally male roles over time, versus childhood factors. Drawing on three cohort studies, which follow individuals born in the UK in 1958, 1970 and 2000, we compare the shift in the tendency of females in these cohorts to sort into traditionally male roles compared to males, to the combined effect of a large set of childhood variables. For all three cohorts, we find strong evidence of sorting along gendered lines, which has decreased over time, yet there is no erosion of the gender gap in the tendency to sort into occupations with the highest share of males. Within the cohort, we find little evidence that childhood variables change the tendency for females of either the average or highest ability to sort substantively differently. Our work is highly suggestive that temporal shifts are what matter in determining the differential gendered sorting patterns we have seen over the last number of decades, and also those that remain today. These temporal changes include attitudinal changes, technology advances, policy changes and economic shifts

Certificate of Approval: Friend or Foe?

A certificate of approval (COA) is required for state- funded projects that impact historic properties. Sometimes seen as a preferable alternative to Section 106, this presentation will discuss the challenges and opportunities for local governments in following the COA process

Multiphase flow analysis of cylinder using a new cavitation model

Cavitating flow simulation is of practical importance for many engineering systems, such as marine propellers, pump impellers, nozzles, injectors, torpedoes, etc. The present work is to test a new cavitation model. The governing equation is the Navier-Stokes equation based on an homogeneous mixture model. The solver employs an implicit preconditioning algorithm in curvilinear coordinates. The computations have been carried out for the cylinders with 0-, 1/2- and 1-caliber forebody and then compared with experiments and other numerical results. Fairly good agreement with experiments and numerical results has been achieved.http://deepblue.lib.umich.edu/bitstream/2027.42/84283/1/CAV2009-final99.pd