An experiment (E166) at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme in which a multi-GeV electron beam passed through a helical undulator to generate multi-MeV, circularly polarized photons which were then converted in a thin target to produce positrons (and electrons) with longitudinal polarization above 80% at 6 MeV. The results are in agreement with Geant4 simulations that include the dominant polarization-dependent interactions of electrons, positrons and photons in matter.

None

The Java Metadata Facility is introduced by Java Specification Request (JSR) 175 [1], and incorporated into the Java language specification [2] in version 1.5 of the language. The specification allows annotations on Java program elements: classes, interfaces, methods, and fields. Annotations give programmers a uniform way to add metadata to program elements that can be used by code checkers, code generators, or other compile-time or runtime components. Annotations are defined by annotation types. These are defined the same way as interfaces, but with the symbol {at} preceding the interface keyword. There are additional restrictions on defining annotation types: (1) They cannot be generic; (2) They cannot extend other annotation types or interfaces; (3) Methods cannot have any parameters; (4) Methods cannot have type parameters; (5) Methods cannot throw exceptions; and (6) The return type of methods of an annotation type must be a primitive, a String, a Class, an annotation type, or an array, where the type of the array is restricted to one of the four allowed types. See [2] for additional restrictions and syntax. The methods of an annotation type define the elements that may be used to parameterize the annotation in code. Annotation types may have default …

This report provides an overview of major legislative and policy developments related to campaign finance during the 110th Congress.

Driven by the hydrophobic effect, a water-soluble, chiral, self-assembled supramolecular host is able to encapsulate hydrophobic organic guests in aqueous solution. Small aromatics can be encapsulated in the supramolecular assembly, and the simultaneous encapsulation of multiple guests is observed in many cases. The molecular host assembly is able to recognize different substitutional isomers of disubstituted benzenes with ortho substitution leading to the encapsulation of two guests, but meta or para substitution leading to the encapsulation of only one guest. The scope of hydrophobic guest encapsulation is further explored with chiral natural product guests. Upon encapsulation of chiral guests into the racemic host, diastereomeric host-guest complexes are formed with observed diastereoselectivities of up to 78:22 in the case of fenchone.

If there is a single word that both characterized 2007 and dominated the thoughts and actions of many Laboratory employees throughout the year, it is transition. Transition refers to the major shift that took place on October 1, when the University of California relinquished management responsibility for Lawrence Livermore National Laboratory (LLNL), and Lawrence Livermore National Security, LLC (LLNS), became the new Laboratory management contractor for the Department of Energy's (DOE's) National Nuclear Security Administration (NNSA). In the 55 years under the University of California, LLNL amassed an extraordinary record of significant accomplishments, clever inventions, and momentous contributions in the service of protecting the nation. This legacy provides the new organization with a built-in history, a tradition of excellence, and a solid set of core competencies from which to build the future. I am proud to note that in the nearly seven years I have had the privilege of leading the Computation Directorate, our talented and dedicated staff has made far-reaching contributions to the legacy and tradition we passed on to LLNS. Our place among the world's leaders in high-performance computing, algorithmic research and development, applications, and information technology (IT) services and support is solid. I am especially gratified to …

Understanding feedbacks between terrestrial and atmospheric systems is vital for predicting the consequences of global change, particularly in the rapidly changing Arctic. Fire is a key process in this context, but the consequences of altered fire regimes in tundra ecosystems are rarely considered, largely because tundra fires occur infrequently on the modern landscape. We present paleoecological data that indicate frequent tundra fires in northcentral Alaska between 14,000 and 10,000 years ago. Charcoal and pollen from lake sediments reveal that ancient birchdominated shrub tundra burned as often as modern boreal forests in the region, every 144 years on average (+/- 90 s.d.; n = 44). Although paleoclimate interpretations and data from modern tundra fires suggest that increased burning was aided by low effective moisture, vegetation cover clearly played a critical role in facilitating the paleo-fires by creating an abundance of fine fuels. These records suggest that greater fire activity will likely accompany temperature-related increases in shrub-dominated tundra predicted for the 21st century and beyond. Increased tundra burning will have broad impacts on physical and biological systems as well as land-atmosphere interactions in the Arctic, including the potential to release stored organic carbon to the atmosphere.

This report discusses the national security problem of China's role in weapons proliferation and issues related to the U.S. policy response, including legislation, since the mid-1990's.

This report outlines Iran's activities and influence in Iraq. Iran is materially assisting major Shiite Muslim political factions in Iraq, most of which have longstanding ideological, political, and religious ties to Tehran, and their armed militias.

None

The Head Observation Organizer, HObO, is a computer program that stores and manages measured ground-water levels. HObO was developed to help ground-water modelers compile, manage, and document water-level data needed to calibrate ground-water models. Well-construction and water-level data from the U.S. Geological Survey National Water Database (NWIS) easily can be imported into HObO from the NWIS web site (NWISWeb). The water-level data can be flagged to determine which data will be included in the calibration data set. The utility program HObO_NWISWeb was developed to simplify the down loading of well and water-level data from NWISWeb. An ArcGIS NWISWeb Extension was developed to retrieve site information from NWISWeb. A tutorial is presented showing the basic elements of HObO.

This report provides an overview of Jordanian politics and current issues in U.S. -Jordanian relations. It provides a brief overview of Jordan's government and economy and of its cooperation in promoting Arab-Israeli peace and other U.S. policy objective in the Middle East.

Vacuum studies of metal single crystal surfaces using electron and molecular beam scattering revealed that the surface atoms relocate when the surface is clean (reconstruction) and when it is covered by adsorbates (adsorbate induced restructuring). It was also discovered that atomic steps and other low coordination surface sites are active for breaking chemical bonds (H-H, O=O, C-H, C=O and C-C) with high reaction probability. Investigations at high reactant pressures using sum frequency generation (SFG)--vibrational spectroscopy and high pressure scanning tunneling microscopy (HPSTM) revealed bond breaking at low reaction probability sites on the adsorbate-covered metal surface, and the need for adsorbate mobility for continued turnover. Since most catalysts (heterogeneous, enzyme and homogeneous) are nanoparticles, colloid synthesis methods were developed to produce monodispersed metal nanoparticles in the 1-10 nm range and controlled shapes to use them as new model catalyst systems in two-dimensional thin film form or deposited in mesoporous three-dimensional oxides. Studies of reaction selectivity in multipath reactions (hydrogenation of benzene, cyclohexene and crotonaldehyde) showed that reaction selectivity depends on both nanoparticle size and shape. The oxide-metal nanoparticle interface was found to be an important catalytic site because of the hot electron flow induced by exothermic reactions like carbon monoxide oxidation.

Water-content profiles across the membrane electrode assembly of a polymer-electrolyte fuel cell were measured using high-resolution neutron imaging and compared to mathematical-modeling predictions. It was found that the membrane held considerably more water than the other membrane-electrode constituents (catalyst layers, microporous layers, and macroporous gas-diffusion layers) at low temperatures, 40 and 60 C. The water content in the membrane and the assembly decreased drastically at 80 C where vapor transport and a heat-pipe effect began to dominate the water removal from the membrane-electrode assembly. In the regimes where vapor transport was significant, the through-plane water-content profile skewed towards the cathode. Similar trends were observed as the relative humidity of the inlet gases was lowered. This combined experimental and modeling approach has been beneficial in rationalizing the results of each and given insight into future directions for new experimental work and refinements to currently available models.

This short paper summarizes the results we presented at the LEHTSC2007 conference. Recent doping and temperature dependence of angle-resolved photoemission data of underdoped superconducting cuprate Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (Bi2212) have revealed the presence of two energy scales exhibiting distinct behaviours. One, which dominates the antinodal region, increases with underdoping and does not show obvious temperature dependence across Tc. This is a behaviour known for more than a decade and considered as the general gap behaviour in the underdoped regime. The other, which dominates the near-nodal regime, does not increase with less doping and opens near Tc via a BCS-like temperature dependence. This is a behaviour not previously observed in the single particle spectra. We propose a momentum space picture of these two energy scales or energy gaps that could resolve the seemingly contradictory gap measurements among different experimental techniques. Our results have also further constrained the theory for high-Tc superconducting cuprates.

The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of illness and injury surveillance activities that provide an early warning system to detect health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence, occupational injuries and illnesses, and disabilities and deaths among current workers.

Testimony issued by the Government Accountability Office with an abstract that begins "The U.S. Coast Guard, a multi-mission maritime military service within the Department of Homeland Security, has requested more than $9 billion for fiscal year 2009 to address its responsibilities for homeland security missions (such as undocumented migrant interdiction) and non-homeland security missions (such as environmental protection). Integral to conducting its missions, is the Deepwater program--a 25-year, $24 billion effort to upgrade or replace vessels and aircraft. This testimony discusses: budget request and trends, and performance statistics, challenges in balancing operations across multiple missions, and Deepwater affordability, management, and its impact on operations. GAO's comments are based on products issued from 1997 to 2008. This testimony also discusses on-going work related to patrol boat operations. To conduct its work, GAO analyzed documentation and interviewed relevant officials."

A letter report issued by the Government Accountability Office with an abstract that begins "In January 2007 the President announced an initiative, referred to as Grow the Force, to increase the end strength in the Army by more than 74,000 by 2013 and the Marine Corps by 27,000 personnel by 2011 to enhance U.S. forces, reduce stress on deployable personnel, and provide necessary forces for success in the Global War on Terrorism. The Department of Defense (DOD) estimates that it will need more than $17 billion for facilities to accommodate the planned personnel increases. GAO was asked to review (1) the process the Army and Marine Corps used to develop construction projects associated with Grow the Force, (2) the extent to which the projects submitted in DOD's budget requests for fiscal years 2007 and 2008 support the initiative, and (3) whether the Army and Marine Corps plan to use temporary facilities while construction projects are completed. GAO reviewed the construction projects associated with Grow the Force in DOD's budget requests for fiscal years 2007 and 2008, reviewed stationing documents, and interviewed officials at Army and Marine Corps headquarters and six installations on the process used to develop projects. In comments …

A letter report issued by the Government Accountability Office with an abstract that begins "Improvised explosive devices (IED) have been and continue to be a significant threat to U.S. forces. The Department of Defense (DOD) expanded efforts to defeat IEDs with the establishment of the Joint Improvised Explosive Device Defeat Organization (JIEDDO) in January 2006. GAO was asked to review JIEDDO's management and operations. For this second report in its series, GAO determined (1) the extent to which JIEDDO's management processes provide adequate assurances that its financial information is accurate and provides transparency over its operations and (2) the extent to which JIEDDO identifies, records, tracks, and reports numbers of all personnel, including contractors. GAO analyzed data for the first half of fiscal year 2007, which included 47 funding transactions totaling $1.34 billion for 24 initiatives to address these objectives."

Testimony issued by the Government Accountability Office with an abstract that begins "During the last decade, conflict in the Democratic Republic of the Congo (DRC)--one of the world's poorest countries--led directly or indirectly to the deaths of an estimated 5.4 million Congolese. A U.S.-supported peace process began in 2001, and the country's first democratically elected president in 40 years was inaugurated in 2006. However, conflict in the country has continued. In enacting the Democratic Republic of the Congo Relief, Security, and Democracy Promotion Act of 2006 (the Act), Congress established 15 U.S. policy objectives that address humanitarian, social development, economic and natural resource management, governance, and security concerns in the DRC. The Act mandated that GAO review U.S. programs in the DRC that support these policy objectives. In this testimony, based on its December 2007 report, GAO identifies (1) U.S. programs and activities that support the Act's objectives, (2) major challenges hindering the accomplishment of the objectives. For its report, GAO obtained and analyzed program documents for seven U.S. agencies--the Departments of Agriculture (USDA), Defense (DOD), Health and Human Services (HHS), Labor (DOL), State, and the Treasury and the U.S. Agency for International Development (USAID). GAO also met with officials …

Testimony issued by the Government Accountability Office with an abstract that begins "Since September 11, 2001, the need to secure U.S. borders has increased in importance and attracted greater public and Congressional attention. The Department of Homeland Security (DHS) has spent billions of dollars to prevent the illegal entry of individuals and contraband between ports of entry--government-designated locations where DHS inspects persons and goods to determine whether they may be lawfully admitted into the country. Yet, while DHS apprehends hundreds of thousands of such individuals each year, several hundreds of thousands more enter the country illegally and undetected. The U.S. Customs and Border Protection (CBP), a component of DHS, is the lead federal agency in charge of securing our nation's borders. This testimony summarizes GAO's work on DHS's efforts on selected border security operations and programs related to (1) inspecting travelers at U.S. ports of entry, (2) detecting individuals attempting to enter the country illegally between ports of entry, and (3) screening of international travelers before they arrive in the United States and challenges remaining in these areas. GAO's observations are based on products issued from May 2006 through February 2008. In prior reports, GAO has recommended various actions to …

Testimony issued by the Government Accountability Office with an abstract that begins "Hospitals submit data on a series of quality measures to the Centers for Medicare & Medicaid Services (CMS) and receive scores on their performance. CMS instituted the Reporting Hospital Quality Data for Annual Payment Update Program (APU program) to collect the quality data from hospitals and report their rates on the measures on its Hospital Compare Web site. For hospital quality data to be useful to patients and other users, they need to be reliable, that is, accurate and complete. The Deficit Reduction Act of 2005 directed CMS to implement a value-based purchasing program for Medicare that beginning in fiscal year 2009 would adjust payments to hospitals based on factors related to the quality of care they provide. This statement provides information on (1) how hospitals collect and submit quality data to CMS and (2) how CMS works to ensure the reliability of the quality data submitted. This statement is based primarily on Hospital Quality Data: HHS Should Specify Steps and Time Frame for Using Information Technology to Collect and Submit Data (GAO-07-320, Apr. 25, 2007) and Hospital Quality Data: CMS Needs More Rigorous Methods to Ensure Reliability …

Testimony issued by the Government Accountability Office with an abstract that begins "The housing government-sponsored enterprises (GSEs)--Fannie Mae, Freddie Mac, and the Federal Home Loan Bank System (FHLBank System), play a critical role in the nation's housing finance system. However, concerns exist that the fragmented federal oversight structure for the GSEs is not well positioned to help ensure that they operate in a safe and sound manner and fulfill their housing missions. This testimony provides information on the GSEs' missions and risks, the current regulatory structure, and proposed regulatory reforms. To prepare this testimony, GAO relied on a substantial body of previous work and updated its analysis in light of recent events."

A letter report issued by the Government Accountability Office with an abstract that begins "Surface transportation programs need to be reexamined in the context of the nation's current unsustainable fiscal path. Surface transportation programs are particularly ready for review as the Highway Trust Fund faces a fiscal imbalance at a time when both congestion and travel demand are growing. As you requested, this report (1) provides an overview of the federal role in surface transportation and the goals and structures of federal programs, (2) summarizes GAO's conclusions about the structure and performance of these programs, and (3) provides principles to assess options for focusing future surface transportation programs. GAO's study is based on prior GAO reports, stakeholder reports and interviews, Department of Transportation documents, and the views of transportation experts."