Melting and differentiation of early-formed asteroids: The perspective from high precision oxygen isotope studies

A number of distinct methodologies are available for determining the oxygen isotope composition of minerals and rocks, these include laser-assisted fluorination, secondary ion mass spectrometry (SIMS)and UV laser ablation. In this review we focus on laser-assisted fluorination, which currently achieves the highest levels of precision available for oxygen isotope analysis. In particular, we examine how results using this method have furthered our understanding of early-formed differentiated meteorites. Due to its rapid reaction times and low blank levels, laser-assisted fluorination has now largely superseded the conventional externally-heated Ni “bomb” technique for bulk analysis. Unlike UV laser ablation and SIMS analysis, laser-assisted fluorination is not capable of focused spot analysis. While laser fluorination is now a mature technology, further analytical improvements are possible via refinements to the construction of sample chambers, clean-up lines and the use of ultra-high resolution mass spectrometers. High-precision oxygen isotope analysis has proved to be a particularly powerful technique for investigating the formation and evolution of early-formed differentiated asteroids and has provided unique insights into the interrelationships between various groups of achondrites. A clear example of this is seenin samples that lie close to the terrestrial fractionation line (TFL). Based on the data from conventional oxygen isotope analysis, it was suggested that the main-group pallasites, the howardite eucrite diogenite suite (HEDs) and mesosiderites could all be derived from a single common parent body. However,high precision analysis demonstrates that main-group pallasites have a Δ17O composition that is fully resolvable from that of the HEDs and mesosiderites, indicating the involvement of at least two parent bodies. The range of Δ17O values exhibited by an achondrite group provides a useful means of assessing the extent to which their parent body underwent melting and isotopic homogenization. Oxygen isotope analysis can also highlight relationships between ungrouped achondrites and the more well-populated groups. A clear example of this is the proposed link between the evolved GRA 06128/9 meteorites and the brachinites. The evidence from oxygen isotopes, in conjunction with that from other techniques, indicates that we have samples from approximately 110 asteroidal parent bodies (∼60 irons, ∼35 achondrites and stony-iron, and ∼15 chondrites) in our global meteorite collection. However, compared to the likely size of the original protoplanetary asteroid population, this is an extremely low value. In addition, almost all of the differentiated samples (achondrites, stony-iron and irons) are derived from parent bodies that were highly disrupted early in their evolution. High-precision oxygen isotope analysis of achondrites provides some important insights into the origin of mass-independent variation in the early Solar System. In particular, the evidence from various primitive achondrite groups indicates that both the slope 1 (Y&R) and CCAM lines are of primordial significance. Δ17O differences between water ice and silicate-rich solids were probably the initial source of the slope 1 anomaly. These phases most likely acquired their isotopic composition as a result of UV photo-dissociation of CO that took place either in the early solar nebula or precursor giant molecular cloud. Such small-scale isotopic heterogeneities were propagated into larger-sized bodies, such as asteroids and planets, as a result of early Solar System processes, including dehydration, aqueous alteration,melting and collisional interactions

SoK: Layer-Two Blockchain Protocols

Blockchains have the potential to revolutionize markets and services. However, they currently exhibit high latencies and fail to handle transaction loads comparable to those managed by traditional financial systems. Layer-two protocols, built on top of layer-one blockchains, avoid disseminating every transaction to the whole network by exchanging authenticated transactions off-chain. Instead, they utilize the expensive and low-rate blockchain only as a recourse for disputes. The promise of layer-two protocols is to complete off-chain transactions in sub-seconds rather than minutes or hours while retaining asset security, reducing fees and allowing blockchains to scale. We systematize the evolution of layer-two protocols over the period from the inception of cryptocurrencies in 2009 until today, structuring the multifaceted body of research on layer-two transactions. Categorizing the research into payment and state channels, commit-chains and protocols for refereed delegation, we provide a comparison of the protocols and their properties. We provide a systematization of the associated synchronization and routing protocols along with their privacy and security aspects. This Systematization of Knowledge (SoK) clears the layer-two fog, highlights the potential of layer-two solutions and identifies their unsolved challenges, indicating propitious avenues of future work

Burden of injury along the development spectrum: Associations between the Socio-demographic Index and disability-adjusted life year estimates from the Global Burden of Disease Study 2017

Background: The epidemiological transition of non-communicable diseases replacing infectious diseases as the main contributors to disease burden has been well documented in global health literature. Less focus, however, has been given to the relationship between sociodemographic changes and injury. The aim of this study was to examine the association between disability-adjusted life years (DALYs) from injury for 195 countries and territories at different levels along the development spectrum between 1990 and 2017 based on the Global Burden of Disease (GBD) 2017 estimates. Methods: Injury mortality was estimated using the GBD mortality database, corrections for garbage coding and CODEm-the cause of death ensemble modelling tool. Morbidity estimation was based on surveys and inpatient and outpatient data sets for 30 cause-of-injury with 47 nature-of-injury categories each. The Socio-demographic Index (SDI) is a composite indicator that includes lagged income per capita, average educational attainment over age 15 years and total fertility rate. Results: For many causes of injury, age-standardised DALY rates declined with increasing SDI, although road injury, interpersonal violence and self-harm did not follow this pattern. Particularly for self-harm opposing patterns were observed in regions with similar SDI levels. For road injuries, this effect was less pronounced. Conclusions: The overall global pattern is that of declining injury burden with increasing SDI. However, not all injuries follow this pattern, which suggests multiple underlying mechanisms influencing injury DALYs. There is a need for a detailed understanding of these patterns to help to inform national and global efforts to address injury-related health outcomes across the development spectrum

Burden of injury along the development spectrum : associations between the Socio-demographic Index and disability-adjusted life year estimates from the Global Burden of Disease Study 2017

Background The epidemiological transition of non-communicable diseases replacing infectious diseases as the main contributors to disease burden has been well documented in global health literature. Less focus, however, has been given to the relationship between sociodemographic changes and injury. The aim of this study was to examine the association between disability-adjusted life years (DALYs) from injury for 195 countries and territories at different levels along the development spectrum between 1990 and 2017 based on the Global Burden of Disease (GBD) 2017 estimates. Methods Injury mortality was estimated using the GBD mortality database, corrections for garbage coding and CODEm-the cause of death ensemble modelling tool. Morbidity estimation was based on surveys and inpatient and outpatient data sets for 30 cause-of-injury with 47 nature-of-injury categories each. The Socio-demographic Index (SDI) is a composite indicator that includes lagged income per capita, average educational attainment over age 15 years and total fertility rate. Results For many causes of injury, age-standardised DALY rates declined with increasing SDI, although road injury, interpersonal violence and self-harm did not follow this pattern. Particularly for self-harm opposing patterns were observed in regions with similar SDI levels. For road injuries, this effect was less pronounced. Conclusions The overall global pattern is that of declining injury burden with increasing SDI. However, not all injuries follow this pattern, which suggests multiple underlying mechanisms influencing injury DALYs. There is a need for a detailed understanding of these patterns to help to inform national and global efforts to address injury-related health outcomes across the development spectrum.Peer reviewe

Reducing Obesity Among American Women

In 1998, heart disease killed approximately 371,000 women in the United States, more that double the second leading cause of death, cancer. Obesity is the leading contributor to diseases of the heart and also the most controllable cause. We discuss several methods commonly used in the U.S. to control obesity, including, diet pills, exercise, better nutrition, and surgery. We considered the pros and cons of each weight control technique, concluding that most effective way to improve long-term health is via nutrition and exercise. We propose a campaign to communicate the benefits of good nutrition and exercise to the women of the U.S. through targeted, customized advertisements. The campaign will focus on presenting the health risks, namely heart disease, of obesity and the alternatives available to improve their health, reducing their risk of heart disease

Outsourcing at LSI Logic

This project presents a real decision involving the outsourcing of technicians at LSI Logic

Team Five A\u27s

The purpose of this report is for Team Five A· s to analyze and explain the factors and experiences that contributed as well as detracted to its own evolution from a working group to a high performance team. We will accomplish this objective by outlining the cultural diversity of the various team members based on nationality as well as by identifying the observations and experiences the team associated with the five stages of our model of team development. This report will explain each stage of our model, will identify the lessons we have learned, and will provide recommendations for how we would conduct team evolution in the future

Cross-Cultural Teams and Projects: Issues and Trends in the ‘90s

Knowledge sharing in the 1990s has grown, having significant bearing on the success of today\u27s global business ventures. With the speed of innovation, and advances in communication and transportation technology, companies must respond faster and more efficiently than ever before to gain market share. To create a competitive advantage, companies are increasingly dependent on projects involving cross-cultural teams. The growing trend of utilizing cross-cultural teams has challenged corporations to learn how to effectively manage their diversity and harness its ingenuity to produce high performance. This study seeks to identify critical issues involved in sharing knowledge among cross-cultural teams. From an extensive literature search and a collaborative synthesis of information, our findings indicate that trust is critical to success. Without a solid foundation of trust, teams will not bond. During the process of knowledge sharing, information becomes distorted causing misguided decisions and false conclusions. The use of advanced communication technology will continue to increase the effectiveness of information dissemination. As knowledge flows throughout the cross-cultural team, a concentration of diversity leads to innovation and creativity. Managers of cross-cultural teams are learning to adapt their management style to foster an open and honest environment that promotes skills and encourages team members to disclose knowledge freely

Technology Selection: Application of Goal Programming Technique in Brownfield Industry

Abstract: In the brown field cleanup process, the technology selection process is complex due to the number of technologies available as well as the criteria affecting the cleanup. In a complex environment it is often difficult to make such technology tradeoffs. Goal programming offers a management technique to minimize the complexity of decision

Strategy & Policy Issues: Telecommunication Industry

Introduction: This is the era of communications. The impact cannot be overstated. This is one of the most rapidly growing segments of high-tech industry. Rapid changes are taking place the communication market to meet the new demands and to achieve revenue growth. It has also fueled growth and expansion in many other areas of high-tech industry. Once upon a time, information technology (IT) and telecommunication were two separate and discrete entities. Information technology was a means of tracking and storing information, while telecommunication was just a means of keeping us all connected. During past several years, these and other technologies are rapidly converging. The convergence of voice, video and data networks, has created further opportunities and threats for service providers. This convergence with deregulation has created a market where the broadcasters, satellite companies, Internet / service providers and other service providers are looking to provide integrated services to consumers and businesses. In this report, we will outline the telecommunication industry, review the market trends and identify the strategic and policy issues faced by the telecommunications industry.