Aviation Security: Transportation Security Administration May Face Resource and Other Challenges in Developing a System to Screen All Cargo Transported on Passenger Aircraft
Published: 2008-07-15T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: The Implementing Recommendations of the 9/11 Commission Act of 2007 requires the Transportation Security Administration (TSA) to implement a system to physically screen 100 percent of cargo on passenger aircraft by August 2010. To fulfill these requirements, the Department of Homeland Security's (DHS) TSA is developing the Certified Cargo Screening Program (CCSP), which would allow the screening of cargo to occur prior to placement on an aircraft. This testimony addresses four challenges TSA may face in developing a system to screen 100 percent of cargo: (1) deploying effective technologies; (2) changing TSA air cargo screening exemptions; (3) allocating compliance inspection resources to oversee CCSP participants; and (4) securing cargo transported from a foreign nation to the United States. GAO's comments are based on GAO products issued from October 2005 through February 2008, including selected updates conducted in July 2008.
section_title: What GAO Found
paragraphs: DHS has taken steps to develop and test technologies for screening and securing air cargo; however, TSA has not completed assessments of the technologies it plans to use as part of the CCSP. TSA has reported that there are several challenges that must be overcome to effectively implement any of these technologies, including the nature, type, and size of cargo to be screened and the location of air cargo facilities. In addition, the air cargo industry voiced concern about the costs associated with purchasing the screening equipment. GAO will likely review this issue in future work. TSA plans to revise and eliminate screening exemptions for some categories of air cargo, thereby reducing the percentage of cargo transported on passenger aircraft that is subject to alternative methods of screening. However, TSA plans to continue to exempt some types of domestic and outbound cargo (cargo transported by air from the United States to a foreign location) after August 2010. TSA based its determination regarding the changing of exemptions on professional judgment and the results of air cargo vulnerability assessments. However, TSA has not completed all of its air cargo vulnerability assessments, which would further inform its efforts. TSA officials stated there may not be enough compliance inspectors to oversee implementation of the CCSP and is anticipating requesting an additional 150 inspectors for fiscal year 2010. They further stated that they have not formally assessed the number of inspectors the agency will need. Without such an assessment, TSA may not be able to ensure that CCSP entities are meeting TSA requirements to screen and secure cargo. To ensure that existing air cargo security requirements are being implemented as required, TSA conducts audits, referred to as compliance inspections, of air carriers that transport cargo. The compliance inspections range from a comprehensive review of the implementation of all security requirements to a review of at least one security requirement by an air carrier or freight forwarder (which consolidates cargo from many shippers and takes it to air carriers for transport). GAO reported in October 2005 that TSA had conducted compliance inspections on fewer than half of the estimated 10,000 freight forwarders nationwide and, of those, had found violations in over 40 percent of them. GAO also reported that TSA had not analyzed the results of compliance inspections to systematically target future inspections. GAO reported in April 2007 that more work remains for TSA to strengthen the security of cargo transported from a foreign nation to the United States, referred to as inbound air cargo. Although TSA is developing a system to screen 100 percent of domestic and outbound cargo, TSA officials stated that it does not plan to include inbound cargo because it does not impose its security requirements on foreign countries. TSA officials said that vulnerabilities to inbound air cargo exist and that these vulnerabilities are in some cases similar to those of domestic air cargo, but stated that each foreign country has its own security procedures for flights coming into the United States.

section_title: Letter
paragraphs: We appreciate the opportunity to participate in today’s hearing to discuss  the security of the air cargo transportation system. In response to the  terrorist attacks of September 11, 2001, the Aviation and Transportation  Security Act was enacted in November 2001, which created the  Transportation Security Administration (TSA) and required it to provide  for the screening of all passengers and property, including cargo, U.S.  mail, and carry-on and checked baggage that is transported onboard  passenger aircraft. Recognizing the need to strengthen the security of air  cargo, Congress enacted, and the President signed into law, the  Implementing Recommendations of the 9/11 Commission Act of 2007,  which requires TSA to implement a system to physically screen 50 percent  of cargo on passenger aircraft by February 2009, and 100 percent of such  cargo by August 2010. To fulfill the requirements of the Act, TSA is  developing a program, referred to as the Certified Cargo Screening  Program (CCSP), which would allow the screening of air cargo to take  place at various points throughout the air cargo supply chain. Under the  CCSP, Certified Cargo Screening Facilities (CCSF), such as shippers,  manufacturing facilities, and freight forwarders that meet security  requirements established by TSA, will volunteer to screen cargo prior to  its loading onto an aircraft. Participation of the air cargo industry is  critical to the successful implementation of the CCSP. According to TSA  officials, air carriers will ultimately be responsible for screening 100  percent of cargo transported on passenger aircraft should air cargo  industry entities not volunteer to become a CCSF.
My testimony today focuses on the challenges TSA may face as it works to  develop a system to screen 100 percent of cargo transported on passenger  aircraft by August 2010. Our comments are based on GAO reports and  testimonies issued between October 2005 and February 2008 addressing  the security of the air cargo transportation system, including selected  updates to this work conducted in July 2008. In addition, this statement  includes selected information collected during our review of TSA’s report  on its air cargo screening exemptions as mandated by the Implementing  Recommendations of the 9/11 Commission Act of 2007. This review was  completed in July 2008 and has yet to be publicly issued. We will initiate a  review of TSA’s efforts to meet the requirement to screen 100 percent of  cargo transported on passenger aircraft in the near future, at the request of  the Chairman of the House Committee on Homeland Security and  Congressman Edward Markey.
We conducted our work in accordance with generally accepted  government auditing standards. Those standards require that we plan and  perform the audit to obtain sufficient, appropriate evidence to provide a  reasonable basis for our findings and conclusions based on our audit  objectives. We believe that the evidence obtained provides a reasonable  basis for our findings and conclusions based on our audit objectives.
subsections: section_title: Background
paragraphs: Air cargo ranges in size from 1 pound to several tons, and in type from  perishables to machinery, and can include items such as electronic  equipment, automobile parts, clothing, medical supplies, other dry goods,  fresh cut flowers, fresh seafood, fresh produce, tropical fish, and human  remains. Cargo can be shipped in various forms, including large containers  known as unit loading devices that allow many packages to be  consolidated into one container that can be loaded onto an aircraft,  wooden crates, assembled pallets, or individually wrapped/boxed pieces,  known as break bulk cargo. Participants in the air cargo shipping process  include shippers, such as individuals and manufacturers; indirect air  carriers, also referred to as freight forwarders; air cargo handling agents  who process and load cargo onto aircraft on behalf of air carriers; and air  carriers that store, load, and transport cargo. A shipper may also send  freight by directly packaging and delivering it to an air carrier’s ticket  counter or sorting center where either the air carrier or a cargo handling  agent will sort and load cargo onto the aircraft.
According to TSA’s Air Cargo Strategic Plan, issued in November 2003, the  agency’s mission for the air cargo program is to secure the air cargo  transportation system while not unduly impeding the flow of commerce.  TSA’s responsibilities for securing air cargo include, among other things,  establishing security requirements governing domestic and foreign  passenger air carriers that transport cargo, and domestic freight  forwarders. TSA is also responsible for overseeing the implementation of  air cargo security requirements by air carriers and freight forwarders  through compliance inspections, and, in coordination with the Department  of Homeland Security’s (DHS) Science and Technology (S&T) Directorate,  for conducting research and development of air cargo security  technologies. Air carriers are responsible for implementing TSA security  requirements, predominantly through a TSA-approved security program  that describes the security policies, procedures, and systems the air carrier  will implement and maintain to comply with TSA security requirements.  These requirements include measures related to the acceptance, handling,  and screening of cargo; training of employees in security and cargo  screening procedures; testing employee proficiency in cargo screening;  and access to cargo areas and aircraft. If threat information or events  indicate that additional security measures are needed to secure the  aviation sector, TSA may issue revised or new security requirements in the  form of security directives or emergency amendments applicable to  domestic or foreign air carriers. Air carriers must implement the  requirements set forth in the security directives or emergency  amendments in addition to those requirements already imposed and  enforced by TSA.
DHS’s U.S. Customs and Border Protection (CBP) has primary  responsibility for preventing terrorists and implements of terrorism from  entering the United States. Specifically, CBP screens inbound air cargo  upon its arrival in the United States to ensure that cargo entering the  country complies with applicable laws and does not pose a security risk.  CBP’s efforts include analyzing information on cargo shipments to identify  high-risk cargo arriving in the United States that may contain terrorists or  weapons of mass destruction, commonly known as targeting, and  physically screening this cargo upon its arrival.
Air carriers use several methods and technologies to screen cargo. These  currently include manual physical searches and the use of approved  technology, such as X-ray systems; explosives trace detection systems;  decompression chambers; explosive detection systems (EDS); and  certified explosives detection canine teams. Under TSA’s security  requirements for domestic and inbound cargo, passenger air carriers are  currently required to randomly screen a specific percentage of nonexempt  cargo pieces listed on each airway bill. As of October 2006, domestic  freight forwarders are also required, under certain conditions, to screen a  certain percentage of cargo prior to its consolidation. TSA does not  regulate foreign freight forwarders, or individuals or businesses that have  their cargo shipped by air to the United States.
section_title: DHS Is in the Early Stages of Testing Technologies to Screen and Secure Air Cargo
paragraphs: DHS has taken some steps to develop and test technologies for screening  and securing air cargo, but has not yet completed assessments of the  technologies TSA plans to approve for use as part of the CCSP. According  to TSA officials, there is no single technology capable of efficiently and  effectively screening all types of air cargo for the full range of potential  terrorist threats, including explosives and weapons of mass destruction.  We reported in October 2005, and again in April 2007, that TSA, working  with DHS’s S&T Directorate, was developing and pilot testing a number of  technologies to screen and secure air cargo with minimal impact on the  flow of commerce. DHS officials stated that once the department  determines which technologies it will approve for use with domestic air  cargo, it will consider the use of these technologies for enhancing the  security of inbound cargo shipments. These pilot programs seek to  enhance the security of cargo by improving the effectiveness of air cargo  screening through increased detection rates and reduced false alarm rates,  while addressing the two primary threats to air cargo identified by TSA— hijackers on an all-cargo aircraft and explosives on passenger aircraft. A  description of these pilot programs and their status is included in table 1.
Although TSA is moving forward with its plans to implement a system to  screen 100 percent of cargo transported on passenger aircraft, the agency  has not completed all of its assessments of air cargo screening  technologies. According to TSA officials, the results of its technology tests  will need to be analyzed before the agency determines which technologies  will be certified for screening cargo, and whether it will require air carriers  and other CCSP participants to use such technology. Although TSA has  not completed all of its pilot programs or set time frames for completing  all of them, TSA is planning on allowing CCSFs to use explosives trace  detection, explosive detection system (EDS), X-ray, and other technology  under CCSP for screening cargo. Without all of the results of its pilot  programs or a time frame for their completion, however, TSA cannot be  assured that the technologies the agency plans to approve for screening  cargo as part of the CCSP are effective. GAO will likely review this issue as  part of our planned review of TSA’s efforts to meet the requirement to  screen 100 percent of cargo transported on passenger aircraft.
According to TSA officials, tamper-evident/resistant security seals will be  essential for ensuring that cargo screened under the CCSP has not been  tampered with during transport from the CCSF to the air carrier. Officials  noted that the agency recognizes that the weakest link in the  transportation of air cargo is the chain of custody to and from the various  entities that handle and screen cargo shipments prior to its loading onto  an aircraft. Officials stated that the agency has taken steps to analyze the  chain of custody of cargo under the CCSP, and is drafting a security  program that will address all entities involved in the transportation and  screening of cargo under the CCSP to ensure that the chain of custody of  the cargo is secure. However, as of July 2008, TSA officials stated that the  agency is not conducting a pilot program to test tamper-evident/resistant  security seals. Therefore, the effectiveness of security seals to effectively  prevent cargo shipments from tampering is unknown. GAO will likely  review this issue as part of our planned review of TSA’s efforts to meet the  requirement to screen 100 percent of cargo transported on passenger  aircraft.
In addition, we reported in April 2007 that several air carriers we met with  were using large X-ray machines at facilities abroad to screen entire  pallets of cargo transported on passenger aircraft. These machines allow  for cargo on pallets to undergo X-ray screening without requiring the pallet  to be broken down. We also noted that CBP uses this technology to  screen inbound air cargo once it enters the United States. TSA officials  recently stated that the agency planned to pilot test large X-ray machines,  identifying that large X-ray machines could be used to screen certain types  of cargo that are currently exempt from TSA’s screening requirements, as  part of the agency’s efforts to screen 100 percent of cargo transported on  passenger aircraft. TSA officials stated that the agency plans to evaluate  this equipment beginning late 2008 as part of its CCSP pilot program and  to complete the evaluation at the conclusion of the CCSP pilot in August  2010.
In addition, as part of the agency’s plans to screen 100 percent of cargo  transported on passenger aircraft, TSA is taking steps to expand the use of  TSA-certified explosives detection canine teams to screen cargo before it  is placed onto passenger aircraft. In 2004, TSA conducted a pilot program  that determined that canine teams had an acceptable rate of detecting  explosives in an air cargo environment, even when the teams were not  specifically trained in this area. TSA is in the process of adding 170 canine  teams to support aviation security efforts, of which 85 will be primarily  used to screen air cargo. These teams are to be primarily located at the 20  airports that receive approximately 65 percent of all air cargo transported  within the United States. TSA officials, however, could not identify  whether the additional 85 canine teams will meet the agency’s increasing  screening needs as part of its efforts to screen 100 percent of such cargo,  thus raising questions regarding the future success of the CCSP.
According to TSA officials, the federal government and the air cargo  industry face several challenges that must be overcome to effectively  implement any of these technologies to screen or secure cargo. These  challenges include factors such as the nature, type and size of cargo to be  screened; environmental and climatic conditions that could impact the  functionality of screening equipment; low screening throughput rates;  staffing and training issues for individuals who screen cargo; the location  of air cargo facilities; employee health and safety concerns, such as  worker exposure to radiation; and the cost and availability of screening  technologies. As TSA takes steps to implement the CCSP, it will be critical  for the agency to address these challenges to ensure the effectiveness of  the program.
As TSA proceeds from piloting to implementing the CCSP, the issue of  who purchases the technologies to support the program will have to be  resolved. Specifically, TSA officials stated that under the CCSP, certified  facilities and air carriers will be responsible for purchasing equipment to  screen cargo. Officials noted that many air carriers already have screening  equipment in place at their facilities to support this screening, and stated  that TSA will reimburse CCSFs for the cost of the equipment, such as EDS,  for up to $375,000 per facility as long as these entities continue to meet  security requirements established by TSA. The CCSF, however, will be  responsible for maintaining the screening equipment and purchasing new  equipment in the future. In addition, CCSFs will be required to train their  staff to operate the equipment using TSA’s training standards. Air cargo  industry stakeholders have already raised concerns regarding the cost of  purchasing and maintaining screening equipment to support the CCSP.  According to some industry estimates, the cost of purchasing air cargo  screening equipment will be much more than the $375,000 TSA plans to  reimburse each CCSP participant. In addition, the air cargo industry has  expressed concern regarding the costs associated with training those  individuals who will be operating the air cargo screening equipment.
section_title: TSA Plans to Revise and Eliminate Screening Exemptions for Some Categories of Air Cargo, but Has Not Completed Air Cargo Vulnerability Assessments to Inform Its Efforts
paragraphs: TSA plans to revise and eliminate current exemptions for some categories  of cargo, thereby reducing the percentage of cargo transported on  passenger aircraft that is subject to alternative methods of screening.  These changes will go into effect in early 2009. However, according to  agency officials, TSA made these determinations based on a limited  number of vulnerability assessments, as well as professional judgment. In  February 2008, TSA issued a report assessing existing screening  exemptions for certain kinds of cargo transported on passenger aircraft  and evaluated the risk of maintaining those exemptions. As part of its  assessment, TSA officials stated that they considered and determined the  threat to and vulnerability of the exempted cargo types. TSA officials also  stated they based their determinations on which screening exemptions to  revise, maintain or eliminate in part on results from air cargo vulnerability  assessments at Category X airports they completed in accordance with  law. TSA has completed assessments at 6 of the 27 Category X airports.  Absent the completed assessments, which could help to identify potential  security vulnerabilities associated with the exemptions, TSA does not have  complete information with which to make risk-based decisions regarding  the security of air cargo. TSA officials have acknowledged the importance  of completing air cargo vulnerability assessments and stated that they will  complete them by the end of 2009. Officials further stated that as the  agency conducts additional air cargo vulnerability assessments, they will  assess the results to determine whether existing screening exemptions  should be revised, maintained or eliminated.
section_title: TSA Has Taken Actions to Strengthen Air Cargo Compliance Inspections, but More Resources May Be Needed to Ensure CCSP Participants Are Meeting TSA Screening Requirements
paragraphs: To ensure that existing air cargo security requirements are being  implemented as required, TSA inspects air carriers and freight forwarders  that transport cargo. Under the CCSP, TSA will also have to inspect other  entities, such as shippers, who volunteer to participate in the program.  These compliance inspections range from an annual comprehensive  review of the implementation of all air cargo security requirements to a  more frequent review of at least one security requirement by an air carrier  or freight forwarder. In October 2005, we reported that TSA had  conducted compliance inspections on less than half (49 percent) of the  estimated 10,000 freight forwarder facilities nationwide, and of those  freight forwarders they had inspected, the agency found violations in over  40 percent of them. We also reported that TSA had not determined what  constitutes an acceptable level of performance related to compliance  inspections, or compared air carriers’ and freight forwarders’ performance  against this standard; analyzed the results of inspections to systematically  target future inspections on those entities that pose a higher security risk  to the domestic air cargo system; or assessed the effectiveness of its  enforcement actions taken against air carriers and freight forwarders to  ensure that they are complying with air cargo security requirements. We  recommended that TSA develop a plan for systematically analyzing and  using the results of air cargo compliance inspections to target future  inspections and identify systemwide corrective actions. We also  recommended that TSA assess the effectiveness of enforcement actions in  ensuring air carrier and freight forwarder compliance with air cargo  security requirements. TSA officials stated that, since our report was  issued, the agency has increased the number of inspectors dedicated to  conducting domestic air cargo compliance inspections. Officials also told  us that TSA has begun analyzing compliance inspection results to  prioritize their inspections on those entities that have the highest rates of  noncompliance, as well as newly approved freight forwarders and air  carriers that have yet to be inspected. However, in recent discussions with  TSA officials regarding their plans to implement the CCSP, they stated that  there may not be enough compliance inspectors to conduct compliance  inspections of all the entities that could be a part of the CCSP, which TSA  officials told us could number in the thousands, once the program is fully  implemented by August 2010. As a result, TSA is anticipating requesting an  additional 150 cargo Transportation Security Inspectors for fiscal year  2010 to supplement its existing allocation of 450 Transportation Security  Inspectors. However, TSA officials stated that they have not formally  assessed the number of Transportation Security Inspectors the agency will  need. Without such an assessment, TSA may not be able to ensure that  entities involved in the CCSP are meeting TSA requirements to screen and  secure cargo. GAO will likely review this issue as part of our planned  review of TSA’s efforts to meet the requirement to screen 100 percent of  cargo transported on passenger aircraft.
section_title: TSA Has Not Identified a Strategy for Securing Inbound Air Cargo
paragraphs: We reported in April 2007 that more work remains in order for TSA to  strengthen the security of inbound cargo. As previously stated, TSA is  currently taking steps to develop a system of screening 100 percent of  domestic and outbound cargo transported on passenger aircraft. TSA does  not, however, currently plan to include inbound cargo as part of this  system. TSA officials acknowledge that vulnerabilities to inbound cargo  exist, but stated that each foreign country has its own security procedures  for flights coming into the United States, and further stated that TSA does  not impose its security requirements on foreign countries. According to  TSA, it will continue to work with other countries to encourage the  adoption of uniform measures for screening cargo flights bound for the  United States as it enhances its requirements for screening cargo  originating in the United States. TSA has begun working with foreign  governments to develop uniform air cargo security standards and to  mutually recognize each other’s security standards, referred to as  harmonization. We reported, however, that duplicative air cargo security  standards exist, which can impede the flow of commerce, expose air cargo  shipments to security risk, and damage high-value items.  For example, to  meet TSA requirements, passenger air carriers transporting cargo into the  United States must screen a certain percentage of nonexempt cargo  shipments, even though these shipments may have already been screened  by a foreign government. Air carrier representatives stated that meeting  TSA screening requirements is problematic in certain foreign countries  because air carriers are not permitted to rescreen cargo shipments that  have already been screened by foreign government employees and deemed  secure. These conflicts and duplication of effort could potentially be  avoided through harmonization.
According to TSA officials, pursuing harmonization would improve the  security of inbound cargo and assist TSA in performing its mission. For  example, officials stated that the harmonization of air cargo security  standards would provide a level of security to those entities not currently  regulated by the agency, such as foreign freight forwarders and shippers.  However, achieving harmonization with foreign governments may be  challenging because these efforts are voluntary and some foreign  countries do not share the United States’ view regarding air cargo security  threats and risks. Additionally, foreign countries may lack the resources or  infrastructure needed to develop an air cargo security program as  comprehensive as that of the United States. In April 2007, we  recommended that TSA, in collaboration with foreign governments and  the United States air cargo industry, systematically compile and analyze  information on air cargo security practices used abroad to identify those  that may strengthen TSA’s overall air cargo security program. TSA agreed  with this recommendation and, since the issuance of our report, has  reviewed the air cargo screening models of two foreign countries.  According to TSA officials, this review led to the design of their proposed  CCSP.
Opportunities exist for TSA to further strengthen its screening efforts for  inbound cargo in the following three key areas:  Conducting air cargo vulnerability assessments for inbound cargo.  As noted earlier, TSA is currently conducting air cargo vulnerability  assessments at Category X airports, but is not including inbound cargo in  these assessments. While TSA has plans to conduct vulnerability  assessments as part of its risk-based approach to securing inbound cargo,  the agency has not established a time frame for doing so. Such  assessments could provide information on the potential vulnerabilities  posed by the transport of inbound cargo. We reported in April 2007 that  TSA officials stated that they would conduct vulnerability assessments of  inbound cargo after they had assessed the vulnerability of domestic cargo.  Nevertheless, TSA officials acknowledged that vulnerabilities to inbound  cargo exist and that these vulnerabilities are in some cases similar to those  facing the domestic and outbound air cargo supply chain.
Assessing the vulnerability posed by maintaining screening  exemptions for inbound air cargo. TSA has not assessed the potential  vulnerabilities posed by inbound air cargo screening exemptions. In April  2007, we reported on the potential vulnerabilities associated with inbound  air cargo screening exemptions. Specifically, we reported that screening  exemptions could pose a risk to the inbound air cargo supply chain  because TSA has limited information on the background of and security  risks posed by foreign freight forwarders and shippers whose cargo may  fall into one of the exemption categories. We recommended that TSA  assess whether existing inbound air cargo screening exemptions pose an  unacceptable vulnerability to the air cargo supply chain and if necessary,  address these vulnerabilities. TSA agreed with this recommendation and  noted that the agency had recently revised and eliminated domestic and  outbound air cargo screening exemptions. However, TSA has yet to  address our recommendation for assessing inbound air cargo screening  exemptions.
Updating TSA’s Air Cargo Strategic Plan to address inbound cargo.  As part of TSA’s risk-based approach, TSA issued an Air Cargo Strategic  Plan in November 2003 that focused on securing the domestic air cargo  supply chain. However, in April 2007, we reported that this plan did not  include goals and objectives for securing inbound cargo, which presents  different security challenges than cargo transported domestically. To  ensure that a comprehensive strategy for securing inbound cargo exists,  we recommended that DHS develop a risk-based strategy to address  inbound cargo security that should define TSA’s and CBP’s responsibilities  for ensuring the security of inbound cargo. In response to our  recommendation, CBP issued its International Air Cargo Security Strategic  Plan in June 2007. While this plan identifies how CBP will partner with  TSA, it does not specifically address TSA’s responsibilities in securing  inbound cargo. According to TSA officials, the agency plans to revise its  Air Cargo Strategic Plan in the fall of 2008, and will address TSA’s strategy  for securing cargo from international last points of departure, as well as its  collaborative efforts with CBP to secure this cargo.
Ms. Chairwoman, this concludes my statement. I would be pleased to  answer any questions that you or other members of the subcommittee may  have at this time.
section_title: GAO Contact and Staff Acknowledgments
paragraphs: For further information on this testimony, please contact Cathleen Berrick  at (202) 512- 3404 or at berrickc@gao.gov. Contact points for our Offices of  Congressional Relations and Public Affairs may be found on the last page  of this statement.
Individuals making key contributions to this testimony include Steve D.  Morris, Assistant Director; Lara Kaskie; Tom Lombardi; Meg Ullengren;  and Margaret Vo.
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