On the Gravitational Two-Body System and an Infinite Set of Laplace-Runge-Lenz Vectors

The current approach of a system of two bodies that interact through a gravitational force goes beyond the familiar expositions [1-3] and derives some interesting features and laws that are overlooked. A new expression for the angular momentum of a system in terms of the angular momenta of its parts is deduced. It is shown that the characteristics of the relative motion depend on the system’s total mass, whereas the characteristics of the individual motions depend on the masses of the two bodies. The reduced energy and angular momentum densities are constants of motion that do not depend on the distribution of the total mass between the two bodies;whereas the energy may vary in absolute value from an infinitesimal to a maximum value which occurs when the two bodies are of equal masses. In correspondence with infinite possible ways to describe the absolute rotational positioning of a two body system, an infinite set of Laplace-Runge-Lenz vectors (LRL) are constructed, all fixing a unique orientation of the orbit relative to the fixed stars. The common expression of LRV vector is an approximation of the actual one. The conditions for nested and intersecting individual orbits of the two bodies are specified. As far as we know, and apart from the law of periods, the laws of equivalent orbits concerning their associated periods, areal velocities, angular velocities, velocities, energies, as well as, the law of total angular momentum, were never considered before.

Rays’ Change of Directions between Inertial Frames and Stellar Aberration

The path of a light’s signal is one and the same in the universal space regardless of the inertial frame by which it is identified. However, only one frame can be taken stationary and identified with the universal space while all other frames are moving. The direction of the path of a light’s pulse in a moving frame is determined in terms of its direction in the stationary one;the result is utilized to explain stellar aberration and show that the tilted direction in the moving frame depends only on its velocity. The aberration increment vector is introduced and employed to determine the apparent position of a star at each point of the earth orbit. Aberration in an earth satellite relative to the geocentric frame is presented. The direction’s change of a light beam between graded inertial frames promotes explaining aberration in an earth’s satellite in parallel to stellar aberration on earth.

Hodographs of the Gravitational Two-Body System and Discrepancies between Newtonian Laws of Equivalent Kepler Orbits and General Relativity

We show first that an orbit, which is naturally characterized by its eccentricity and semi-latus rectum, can equally be characterized by other sets of parameters, and proceed to determine mass-independent characterizations. The latter is employed to obtain the laws of equivalent orbits, which by definition have the same eccentricity and orbit’s parameter [1]. These laws relate the values of the same physical observables on two equivalent orbits to the corresponding total mass;they include the laws of velocity, angular velocity, radial velocity, areal velocity, acceleration, period, energy and angular momentum. Regardless of the share of the two bodies of a fixed total mass, the same relative orbit occurs for the same initial conditions. Moreover, the same orbit can be traced by different total masses but with different relative velocities. The concept of a gravitational field generated by a set of masses is shown to be meaningful only when the center of mass is not changed by the test mass. The associated concept of the “nothing”, which is an infinitesimal mass that allows for the property just mentioned to be fulfilled, is introduced and its orbits are determined. The perturbation of the nothing orbits due to its replacement by a finite mass is determined. It is proved that such a replacement can have a qualitative effect resulting in a “phase transition” of an orbit from unbound to bound, and that the nothing’s circular orbits cannot be occupied by any material body. The Galileo law of free fall, on which the equivalence principle hinges and which is exact only for “nothing-like” falling objects, is revised to determine the duration of free fall of a body of an arbitrary mass. The wholeness of Newton’s laws and the associated concept of force as an interaction are highlighted, and some contradictions between the Newtonian laws of equivalent Kepler’s orbits and the general relativistic predictions are discussed. It is demonstrated that Newton’s law of gravitation is not an approximation of Einstein field Equations even in the case of a static weak field. However, both theories have a common limit corresponding to the case in which the alien concept of a field can be incorporated in the Newtonian theory. We also show that the relative velocity’s hodograph [2-4], the alternative Laplace-Runge-Lenz (LRL) vector derived by Hamilton [4-6], as well as an infinite set of LRL vectors, result all from one vector. The hodograph is a proper circular arc for hyperbolic motion, a circle less a point for parabolic motion, and a full circle for bound motion.

Analysis of Construction Duration and Cost for Public Sector Civil Engineering Projects in Libya

Public construction project data were analyzed to develop models for the actual construction duration and actual cost. Based on 50 civil engineering projects in Libya from the database of the Great Man-Made River System 1992-2009, the models identified extension as a main factor that affecting both the actual duration and cost of a project, while considering the contract cost and contract duration as fixed for the project. The suitability of each model was confirmed by examining RMSE (root mean squared error), NSE (Nash-Sutcliffe efficiency), and MEF (modeling efficiency factor). The models were validated with data from 17 different projects. The validation of both models demonstrated that models are very practical and accurate. The models are very effective in capturing the uniqueness of Libyan construction industry practice.

Brownfields and Children under 18 in Detroit

Children in Detroit are disproportionately exposed to toxins and pollutants when compared to children who reside in the suburbs,subjecting Detroit children to many health conditions such as asthma and lead poisoning.This disturbing knowledge was the impetus to focus on looking at GIS datasets that might help start to address the following question:To what extent is the health of Detroit’s children threatened by brownfields in the neighborhoods in which they live and go to school?Three datasets were used to investigate the relationship between under 18 populations and brownfield presence in Detroit.This study was able to identify the potential areas of concern.This study recommends to discern how brownfield may be affecting residents,in particular those residents under the age of 18,by examining smaller areas at a larger scale to get a true picture of the brownfield landscape in Detroit.

Osteonecrosis of the jaw in a patient taking once-yearly infusion of zoledronic acid for osteopenia

Osteonecrosis of the jaw (ONJ) is an adverse effect of nitrogen-containing bisphosphonates. Advancing age, intravenous administration of zoledronic acid (ZOL), history of dento-alveolar surgery, and concomitant systemic diseases such as diabetes are known as risk factors for developing ONJ. However, despite numerous studies, the exact pathophysiology remains unclear and management strategies are largely anecdotal. Once-yearly intravenously administered 5 mg ZOL was approved by the US Food and Drug Administration in 2007 for the treatment of osteoporosis and its efficacy with 3 year-regimen had been recently proven in preventing new clinical fracture. Although occurrences of ONJ have been reported to be rare with this drug administration, available data is very limited and long-term outcomes are lacking. We present a case of ONJ identified in an osteopenic patient with an intermittent but long standing sore mouth related to exposed mandibular bone. Once-yearly infusion of zoledronic acid used in the treatment of osteopenia may contribute to the spontaneous development of ONJ, especially in those presenting with multiple comorbidity factors. This report suggests the importance of health care professionals keeping abreast of new developments in this area and providing appropriate information to their patients.

The Mapping and Characterization of Cruella (Cru), a Novel Allele of Capping Protein α (Cpa), Identified from a Conditional Screen for Negative Regulators of Cell Growth and Cell Division

A Flp/FRT EMS mutagenesis screen was conducted in the eye of Drosophila melanogaster on chromosome 2R to identify negative regulators of cell growth and cell division. In addition to the EMS mutation in the mosaic eye, an ark loss of function allele (ark82) was utilized to block apoptosis in the homozygous mutant cells, setting up a screen for conditional regulators of cell growth and cell division. In the present study, we focus on the characterization and mapping of one mutant that resulted from this screen, Cruella (cru). A cross between flies with the flippase enzyme directed to the developing eye and flies with the mutations cru, ark82, revealed an unusual phenotype that resulted in the homozygous mutant tissue appearing black, in contrast to the expected red. To map the location of this mutation, complementation tests against the Bloomington deficiency kit were conducted. Cru failed to complement previously characterized alleles of capping protein α (cpa). Thus, cpacru is a novel allele of cpa and displays phenotypes similar to previously characterized alleles such as cpa 107E, cpa 69E, and cpascrd . The human homolog, Cap Z, is conserved in humans and serves a similar role in act in filament regulation.

Twitter Application to Chinese Language Learning:Lessons and Suggestions

本行动研究将推特对140字符的要求和中初级中文二语学习者在宽松环境中进行语言输出的需求联系起来,把推特引入大学中文二语课堂。基于学生推特行为的描述性统计数据和学生对期末调查问卷的反馈,本文反思和总结了此次教学探索的经验教训。作者提出,把推特这样的社交应用用作教育工具,任务性学习或项目性学习方面的教学结构设计仍然是必要的。作者也探讨了如何利用推特的社交功能建设中文二语学习者和教育者的学习社区。

On Universal Space and Time

In earlier papers [1]-[4], it was shown that the consistency of the concept of time with motion requires time and distance to be of the same dimension, and thus measured by the same unit. The arising reduced system of units revealed that mass and energy were only different facets of one entity, and resulted in the well-known mass-energy equivalence formula as a natural consequence. The physical space can be identified with any inertial frame, but when it comes to comparing the results of measurements in two frames, or more, only one frame, say S, can be taken stationary and identified with the physical space, whereas all other inertial frames are moving relative to S. The equivalence of inertial frames as sites of one physical world implies that an intrinsic units system of length, time, mass and charge should be defined in terms of basic constituent physical blocks that have the same identity in all inertial frames. A basic feature of the universal space and time theory (UST) is that the same one time prevails in all inertial frames. The scaling transformations (STs) that relate the geometric distances in two frames, S (s) when chosen the stationary frame, are derived, and applied to explain the Doppler’s effect. The time distance between a moving object in S and an observer depends on its state of motion;and the Euclidean form of the STs is employed to explain arrival of some meta-stable at the earth’s surface despite its short lifetime. The quantitative predicted Doppler’s effect, which is in a striking agreement with the Ives-Stilwell experimental results, coincides with the relativistic prediction for longitudinal motion, but yet predicts a complete absence of a transverse effect at a right angle. In coming parts of this work it will be shown that the UST explains elaborately the drag effect, stellar aberration, and produces naturally the relativistic mechanics. The UST will also be completed through deriving the scaling transformations of the second type, by which the null results of Michelson and Morley experiment, Michelson and Gale experiment, and the Sagnac effect are explained. The current work and our intended future works in UST are new versions containing basic conceptions and visions that didn’t appear in earlier versions [1]-[6].

On Universal Mechanics and Superluminal Velocities

In this work we continue to set up the theory of universal space and time and derive the Euclidean form of the scaling transformations. Two types of velocities emerge, inertial and universal, with the former bound by the light velocity c whereas the latter is unbound, and may accommodate consistently particles’ velocities possibly exceeding c. The inertial velocity is the ratio of the simultaneous source’s displacement and the corresponding length of the light trip to the observer, whereas the universal velocity has its familiar meaning for motion in a synchronous inertial frame. Defining the momentum as the product of universal velocity and mass, and utilizing the already established mass-energy equivalence, the mechanics constructed on the bases of the new concepts, named universal mechanics, admits superluminal velocities but yet coincides with the relativistic mechanics in its basic dynamical components and their inter-relations. The possibility of superluminal velocities provides a straight forward explanation of the presence of the μ-meson particles abundantly at the sea level despite their generation at high altitude and their short lifetime.

A Multi-Leveled Approach to Intrusion Detection and the Insider Threat

When considering Intrusion Detection and the Insider Threat, most researchers tend to focus on the network architecture rather than the database which is the primary target of data theft. It is understood that the network level is adequate for many intrusions where entry into the system is being sought however it is grossly inadequate when considering the database and the authorized insider. Recent writings suggest that there have been many attempts to address the insider threat phenomena in regards to database technologies by the utilization of detection methodologies, policy management systems and behavior analysis methods however, there appears to be a lacking in the development of adequate solutions that will achieve the level of detection that is required. While it is true that Authorization is the cornerstone to the security of the database implementation, authorization alone is not enough to prevent the authorized entity from initiating malicious activities in regards to the data stored within the database. Behavior of the authorized entity must also be considered along with current data access control policies. Each of the previously mentioned approaches to intrusion detection at the database level has been considered individually, however, there has been limited research in producing a multileveled approach to achieve a robust solution. The research presented outlines the development of a detection framework by introducing a process that is to be implemented in conjunction with information requests. By utilizing this approach, an effective and robust methodology has been achieved that can be used to determine the probability of an intrusion by the authorized entity, which ultimately address the insider threat phenomena at its most basic level.

Oxidized Dopamine Acrylamide Primer to Achieve Durable Resin-Dentin Bonding

The durability of the resin-dentin bonding interface is a key issue in clinical esthetic dentistry.Inspired by the extraordinary bioadhesive properties of marine mussels in a wet environment,we designed and synthetized N-2-(3,4-dihydroxylphenyl)acrylamide(DAA)according to the functional domain of mussel adhesive proteins.DAA’s properties of collagen cross-linking,collagenase inhibition,inducing collagen mineralization in vitro,and as a novel prime monomer for clinical dentin adhesion use,its optimal parameters,and effect on the adhesive longevity and the bonding interface’s integrity and mineralization,were evaluated in vitro and in vivo.The results showed that oxide DAA can inhibit the activity of collagenase and cross collagen fibers to improve the anti-enzymatic hydrolysis of collagen fibers and induce intrafibrillar and interfibrillar collagen mineralization.As a primer used in the etch-rinse tooth adhesive system,oxide DAA can improve the durability and integrity of the bonding interface by anti-degradation and mineralization of the exposed collagen matrix.Oxidized DAA(OX-DAA)is a promising primer for improving dentin durability;using 5%OX-DAA ethanol solution and treating the etched dentin surface for 30 s is the optimal choice when used as a primer in the etch-rinse tooth adhesive system.

Bryan Van Norden, Taking back Philosophy.: A Multicultural Manifesto

Bryan Van Norden, an American who specializes in Chinese philosophy, has spent much time in Asia and has taught at three esteemed institutions in the US, China, and Singapore.The book is intended to raise interest in Asian philosophy among a wide audience, particularly American students,philosophy faculty, and administrators.Van Norden is keen to promote the study of Asian philosophy;the end of Chapter One tasks faculty and administrators with diversifying their hiring practices and asks students to urge their teachers to broaden course offerings beyond Western philosophy.