Unified Command Research Articles

Hurricane Isaac Post-Storm Response1

ABSTRACT Hurricane Isaac made landfall on August 29, 2012 over Louisiana, lingering overhead for more than 60 hours. While most were concerned with surviving the 80+ mph winds and ensuing storm surge and floods, Coast Guard members statewide knew there would be no calm after the storm; instead it would be a grueling fight to restore the port to normalcy. The slow moving storm caused grounded deep draft vessels and barges, spilled oil, releases of hazardous materials (HAZMAT), and damage to various buildings and infrastructures. U.S. Coast Guard Sector New Orleans integrated local, states, and federal agencies into a Unified Command structure to coordinate limited resources post-storm. Within Sector New Orleans, the Incident Management Division (IMD) made it their primary mission to mitigate any substantial threats of oil discharges or HAZMAT releases and ensure proper cleanup. On September 2, 2012, IMD utilized the Incident Command System (ICS) to establish a Marine Environmental Response (MER) Incident Management Team (IMT) to achieve their post storm mission. The MER IMT consisted of 200 personnel, of which 60 were Coast Guard members, and included representatives from the National Strike Force, U.S. Environmental Protection Agency (EPA), U.S. Fish and Wildlife Service (USFWS), National Oceanic and Atmospheric Administration (NOAA), Louisiana Department of Environmental Quality (LDEQ), Louisiana Oil Spill Coordinator's Office (LOSCO), Louisiana Department of Wildlife and Fisheries (LDWF), and three Oil Spill Removal Organizations (OSROs); together the team collected 4500 barrels of oily water and 1200 HAZMAT containers, deployed over 11,000 feet of containment boom, and federalized three pollution projects. The MER IMT was disestablished on September 28, 2012 leaving Sector New Orleans IMD to maintain complete management of the ongoing federalized projects, “Fantome”, “Map Drilling”, and “Gulf South”. The projects included oil discharges in adjacent waterways of two oil production/storage facilities, oil discharges from fixed facility barges, and oil discharges from a storage platform along the marsh shoreline. Sector New Orleans executed $9.5 million in Oil Spill Liability Trust Funds towards emergency response efforts and successfully restored safety to the public health, welfare, environment, and maritime community.

6. Coordination and control

Any complex operation requires a system for management. In most societies, disaster management is the responsibility of the government. Coordination and control is a system that provides the oversight for all of the disaster management functions. The roles and responsibilities of a coordination and control centre include: (1) planning; (2) maintenance of inventories; (3) activation of the disaster response plan; (4) application of indicators of function; (5) surveillance; (6) information management; (7) coordination of activities of the BSFs; (8) decision-making; (9) priority setting; (10) defining overarching goal and objectives for interventions; (11) applying indicators of effectiveness; (12) applying indicators of benefit and impact; (13) exercising authority; (14) managing resources; (15) initiating actions; (16) preventing influx of unneeded resources; (17) defining progress; (18) providing information; (19) liasing with responding organisations; and (20) providing quality assurance. Coordination and control is impossible without communications. To accomplish coordination and control, three factors must be present: (1) mandate; (2) power and authority; and (3) available resources. Coordination and control is responsible for the evaluation of the effectiveness and benefits/impacts of all interventions. Coordination and control centres (CCCs) are organised hierarchically from the on-scene CCCs (incident command) to local provincial to national CCCs. Currently, no comprehensive regional and international CCCs have been universally endorsed. Systems such as the incident command system, the unified command system, and the hospital incident command system are described as are the humanitarian reform movement and the importance of coordination and control in disaster planning and preparedness.

Unified transition to cooperative unmanned systems under Spatial Grasp paradigm

A novel philosophy, ideology, methodology, and supporting high-level networking technology will be revealed capable of guiding gradual transition to intelligent unmanned systems with a variety of important practical applications. The approach is based on a completely different type of high-level language capable of grasping top semantics of complex spatial operations in dynamic and unpredictable environments while shifting numerous technical details to effective automatic implementation. The language is based on holistic and gestalt principles rather than traditional multi-agent organizations, providing high integrity and super-summative features of the solutions described. Cooperative networked interpretation of the language in distributed systems and different parallel and distributed scenarios in it will be demonstrated that can be performed by any combination of manned and unmanned components under unified command and control provided by the technology described.

The Hartford Consensus: How to Maximize Survivability in Active Shooter and Intentional Mass Casualty Events

The recent events at the Boston Marathon bombings, the bombing at the shopping mall in Nairobi, Kenya, and the shootings at the Navy Yard in Washington, DC continue to make it clear that active shooter and intentional mass casualty incidents require comprehensive responses to increase survival and minimize disabilities. The Joint Committee to Create a National Policy to Enhance Survivability from Mass Casualty Shooting Events was formed to identify the needed changes to improve survival. It was initiated by the American College of Surgeons (ACS) in an effort to ensure that victims receive expeditious treatment of their injuries. On 2 April and 11 July 2013, a group of select representatives from national public safety organizations that included health, law enforcement, fire, prehospital care, trauma care, and the military met in Hartford, Connecticut, USA to suggest strategies to increase survivability from active shooter and intentional mass casualty events. The concepts supported by both meetings have become known as the Hartford Consensus [1, 2]. The overarching principle of the Hartford Consensus is that the current response and management of these events needs to change. Lessons learned from previous events make this clear. An analysis of the emergency medical response at Columbine High School in Colorado revealed that there was significant delay and some victims may have died waiting for medical treatment [3]. More recently, at the Los Angeles Airport shooting on 1 November 2013, an officer was wounded and left unattended for 33 min even though for most of that time there was no threat from the suspected gunman [4]. The officer had no signs of life upon arrival at the medical center and was unable to be revived. Delays such as these are not acceptable. There are several reasons for the delay in attending to victims. The response to events is hindered by the lack of a unified command structure and common language of the various responding groups. Because these events typically happen in a very short time, any delay in formulating a coordinated response can mean the difference between life or death for the victims. Traditionally, responding police officers have focused on suppressing the shooter. Until that is accomplished, treating victims is a secondary objective. Providing hemorrhage control has not been one of their responsibilities. The desire to provide a safe environment for emergency medical services (EMS) has prevented access to victims until law enforcement grants them access. This philosophy has resulted in medical responders waiting at the perimeter of the event. Law enforcement in the past has focused on management of the crime scene and collecting and preserving evidence to the detriment of victim survival. The Hartford Consensus has declared that these response issues must be eliminated and the expeditious attention to victim survival is a priority. The Hartford Consensus produced two documents [1, 2]. The first describes the fundamental concepts to increase survival and the second is a call to action. The call to action is that no one should die from uncontrolled bleeding. An acronym summarizes the needed response: THREAT (T indicates threat suppression, H for hemorrhage control, RE for rapid extrication of the victims from the scene, A for assessment by medical providers, and T for transport to definitive care). Although responders may include the public, law enforcement, EMS/fire/rescue, and definitive trauma care, hemorrhage control must be seen as a core law enforcement responsibility. L. Jacobs (&) Academic Affairs, Hartford Hospital, Hartford, CT, USA e-mail: lenworth.jacobs@hhchealth.org

Japan, the Ministry of Defense and Cyber-Security

Following a series of shocks that rocked Japan's confidence in its cyber-security provisions, in April 2014 the Japanese Ministry of Defense will finally set up a unified command to deal with cyber-security threats. However, many issues, including the role of Japan's military in the protection of critical national infrastructure and the nation's cyber-warfare doctrine, have yet to be finalised. Paul Kallender examines recent policy and posture changes by the Ministry of Defense as it tries to get to grips with new and changing cyber-security challenges.

Persistence of Gulf of Mexico Surface Oil from the 2010 Deepwater Horizon Spill

Persistence of Gulf of Mexico Surface Oil from the 2010 Deepwater Horizon Spill Rick C. Crowsey (bio) British Petroleum (BP) began drilling the Macondo well in the Gulf of Mexico (approximately 50 m (80 km) East-Southeast of South Pass, Louisiana) using the Marianas rig in October 2009. Drilling had reached more than 9,000 feet (2,743 m) below sea level (approximately 4,000 feet (1,219 m) below the sea floor) when Hurricane Ida damaged the rig, requiring it be towed in for repairs. The Deepwater Horizon rig arrived at the Macondo site on January 31, 2010 to complete the planned additional 9,000 feet (2,743 m) of drilling (Graham et al. 2011). After several months of drilling, a negative pressure test was begun on the morning of April 20th as one of the final steps planned for the semisubmersible Deepwater Horizon. An unexpected loss of power, followed by an explosion occurred at approximately 9:49 p.m. that evening. The fire started by the explosion raged aboard the Deepwater Horizon oil rig on the Macondo Prospect for approximately 36 hours before the rig sank (Bly 2010). Hydrocarbons flowed from the reservoir through the well bore until it was finally capped on July 15, 2010 (Graham et al. 2011). When the fire began on the Deepwater Horizon, no one expected it would trigger one of the largest oil spills in the Gulf of Mexico or that it would negatively impact the U.S. Gulf Coast from Texas to Florida. It was only after the rig sank that NOAA ordered acquisition of any and all imagery of the Gulf of Mexico surrounding the Macondo well. Estimates of the flow rate varied widely. Early reports by Unified Command and SkyTruth estimated only a few thousand barrels per day through the end of April 2010 (Ramseur 2011). By the end of May, estimates ranged between a few thousand barrels per day (again reported by Unified Command) to as much as 100,000 barrels per day (by Chiang as a range of 10,000 to 100,000 barrels per day). While the circumstances limit the ability to accurately determine the amount of hydrocarbons expelled from the well prior to the July 15th capping, the On Scene Coordinator Report estimates the total discharge to be approximately 5 million barrels (210 million gallons; Ramseur 2011). Regardless of the accuracy of this value, the magnitude and length of time over which this occurred is chilling. My work as a forensic geographer began when I left NASA in 1996 and has included analysis for one side or the other on lawsuits spawned by similar disasters, including Hurricane Katrina, railroad accidents, oil spills, marine collisions and [End Page 359] spills, light pollution, refinery fires and explosions. Based on this experience I followed the progress of this event with some interest, expecting a call to address what would become a surprisingly difficult question to answer: "Where did the oil go?" As hydrocarbons continued to escape from the well bore at an alarming rate, the question of where the oil was and where it went became more important each day. Surprisingly, the data needed to answer this question quickly became increasingly difficult to find or to access. While NOAA had begun collecting satellite imagery from a variety of sources, including RADARSAT, ENVISAT, and MODIS, the archive of these data along with in situ data was turned over to BP within weeks of the creation of a comprehensive GIS. BP housed it behind a secure firewall. Repeated requests by others and me outside BP for access to the data were met with what appeared to be delay, misdirection, and obfuscation. While access to the source data was denied or limited, most requests were pointed to the ERMA Deepwater Gulf Response website (http://gomex.erma.noaa.gov/erma.html). This site was developed and is maintained jointly by NOAA, EPA, and the University of New Hampshire's Coastal Response Research Center. While this site provides access to visualizations of much of the data needed to figure out where the oil went, it doesn't provide access to the daily imagery or shapefiles of oil extent created by NOAA...

Repurposing Cyber Command

ABSTRACT: Recent debates about the organizational relationship between Cyber Command and the NSA stress political issues over force employment. This article focuses on the latter, making the case that Cyber Command should be split from the NSA, because nations that marshal and mobilize their cyber power and integrate it into strategy and doctrine will ensure significant national security advantage. Cyber Command provides the best route for developing the tactics, techniques, and procedures necessary for achieving these goals. ********** For twenty years, members of the United States' national security community, including readers of this journal, have debated the potential tactical, operational, and strategic effects of cyber components and capabilities. (1) Recently, these discussions have become intertwined with arguments about the organizational relationships as well as the Title 10 (traditional military) and Title 50 (intelligence and covert) authorities that exist under the Unified Command Plan. Because of this expanding controversy, there is a growing chorus calling for a split between the National Security Agency (NSA) and US Cyber Command. These debates are important. Yet they subsume the pivotal issue --how cyber components and capabilities will affect US national security--beneath more transient legal and political issues generated in the wake of Edward Snowden. Furthermore, past and current debates often overlook a basic truth: battlefield outcomes and strategic effects are the product of actual force employment, not theoretical arguments or proving-ground tests. Cyber Command should be cleaved from NSA, but not for reasons of political expediency. Cyber Command should be split from NSA because the United States needs an organizational arrangement that provides for the development and normalization of Title 10 and Title 50 cyber capabilities, while maintaining a focus on how such will affect the use of military force and US national security. Cyber Command should be split from the NSA because nations that marshal and mobilize their cyber power and integrate it into strategy and doctrine will ensure significant national security advantage, and Cyber Command currently provides the best route for achieving such. (2) Cyber Command should be removed from under US Strategic Command and established as a unified combatant command. That action represents the most effective means for developing and maturing the tactics, techniques, and procedures that will allow US cyber components and capabilities to be employed for military purposes and to generate strategic effects. Currently, there are two primary reasons why the establishment of a unified combatant command presents a better solution than tasking existing branch and service structures. First, speed is of the essence. Tasking an existing branch or service, or even establishing a new service, would open up organizational and bureaucratic rivalries likely to slow (if not cripple) the development of cyber components and capabilities. Second, in the near term, Title 10 and Title 50 concerns, vagueness in the cyber rules of engagement, concerns about political blowback, and fears that US cyber weapons could be reverse engineered and used against the United States, all highlight the importance of an organizational solution that synchronizes and deconflicts activities across the whole of government. In short, the United States needs a combatant command that can do two things: (1) craft the tactical, operational, and strategic cyber capabilities US national security will need in the decades to come; and, (2) oversee their application, integration, and execution. Cyber Command is the best choice and now is the time to act. Operationalizing Cyber When Cyber Command was established in 2009, it made sense that it be stood up as a sub-unified command under Strategic Command. Until recently the line between computer network attacks and computer network exploits was chiefly one of intent (i. …

Police Traffic Management System Design Based on GIS

In order to improve the public security organs unified command, rapid response, coordination of combat capability, the paper designs a new type of police traffic management GIS system. The system is a communication, command, control, and information ( C3I ) in one of the complex systems. The system mainly consists of three layers:the dynamic traffic information collection, decision analysis layer, scheduling executive level, as well as to provide various levels of data sharing, access, exchange of data exchange platform, and information exchange for all types of modules communication platform.

Standardized early medical care of Lushan earthquake victims in army hospitals

Objective To summarize the experiences with early treatment of the wounded associated with 4 · 20 Lushan earthquake in army hospitals.Methods Emergency response programs were started and tent hospitals were set up.According to the basic principle of wartime wound treatment regulation,emergency triage,emergency medical care,transferring,specialized treatment and evacuation were performed for the wounded in this earthquake.Results After the earthquake,the emergency rescue programs were started in the hospital.Twenty minutes later,emergence medical team with full equipment were set out for the epicenter and the tent hospitals were set up.A total of 181 earthquake cases were admitted within two weeks,of which 68 (37.6％) were transferred from the scene of earthquake and 113 (62.4％) were transferred after the primary treatment (including cases evacuating from other hospitals).Forty-nine surgeries had been done,including 30 emergence ones.Thirty-four cases (including 14 severe wounded) were evacuated to superior hospitals as their vital signs turned stable.There was no death or surgical wound infection.Conclusions Peacetime complete emergence programs and materials reserves,unified and well-organized command as well as normative grading treatment system in army hospitals assure the standardized medical care with high efficiency and high quality for earthquake victims.However,more researches are needed over diagnosis methods and standards for wound severity,equipment improvement and standards for casualty evacuation. Key words: Wounds and injuries; First aid; Progressive patient care; Earthquakes

Study on Integrated Control of Vehicle Yaw and Rollover Stability Using Nonlinear Prediction Model

This paper proposes the integrated controller of the yaw and rollover stability controls based on the prediction model. A nonlinear 3-DoF vehicle model with a piecewise linearization tire model is built up as the rollover predictive model, and its accuracy is verified by vehicle tests. A yaw stability controller and a rollover stability controller are proposed, respectively. Then coordinated control strategy is investigated for the integration of vehicle yaw and roll stability controls. The additional yaw torque and braking torque of each wheel are calculated. The unified command of valves is sent combined with ABS control algorithm. Virtual tests in CarSim are carried out, including slalom condition and double-lane change condition. Results indicate that the coordinated control algorithm improves vehicle yaw and roll stability effectively.

Negotiating a unified Atlantic naval command: Anglo-American summit talks and the impact of domestic politics

From Trafalgar in 1805 to the Battle of Jutland in 1916, the Royal Navy was in its prime. It symbolised Britain's early industrialisation, safeguarded British trade, protected strategically vital sea lanes around the British Isles and the empire, and projected British power to far-flung corners of the world. Despite British acceptance of naval parity with the United States under the terms of the Five-Power Naval Limitation Treaty signed in Washington in 1922 (and the gradual establishment of the US Navy as the world's most powerful and important naval force), within Britain the Royal Navy remained highly respected and was popularly seen as a yardstick of British greatness. When plans for a unified Supreme Allied Atlantic Naval Command (SACLANT) under an American admiral were leaked in February 1951, furious British popular and political protest ensued. The plans appeared to be a slight upon the Royal Navy, an affront to Britain's status and maritime history, and a damaging reflection of the state of the Anglo-American relationship. The Attlee government was pilloried for accepting SACLANT in principle and, once restored to power in October 1951, Churchill pledged to seek alternative arrangements with President Truman. This article casts new light upon the consequent negotiations about the Atlantic Command at an Anglo-American summit meeting in January 1952. Specifically, it argues that understanding the conduct of these talks and ultimate British acquiescence requires careful consideration of domestic political considerations in Britain and the United States – an explanatory factor hitherto missed in the (surprisingly few) existing analyses of the SACLANT issue.

TRACHEOTOMY DURING THE CARDIOPULMONARY RESUSCITATION PROCESS

ObjectivesTracheotomy is very important in the process of cardiopulmonary resuscitation (CPR), especially the cardiac arrest result form obstruction of respiratory tract. It is advantageous, when tracheotomy is undertaken, that the...

Accuracy of Two-Line-Element Data forGeostationary and High-Eccentricity Orbits

Accuracy of Two-Line-Element Data forGeostationary and High-Eccentricity Orbits

The Creation of Indian Integrated Commands: Organisational Learning and the Andaman and Nicobar Command

India took an unprecedented step 10 years ago by setting up a joint theatre operational command for the Andaman and Nicobar Islands (ANC). This article seeks to examine the following questions: why did India decide to establish its first joint operational command? Why has the creation of this and other unified commands been so incremental in the Indian context? What are the arguments for and against jointness, integration and joint operational commands in the Indian context? The article will firstly discuss the concept of joint operational commands and then theories of organisational military change. Secondly, it will look at the debate in India about jointness and these commands, and how this led to the creation of the ANC. Lastly, it will conclude with observations about the ANC and the future of similar commands in the Indian context. Unless disaster or political events incentivise Indian politicians to force change on the defence establishment, it is unlikely that there will be any further joint operational theatre commands (like the ANC) in the future, but joint operational functional commands (like the strategic forces command, SFC) are more likely.

Reseach on Multimodal Logistics Emergency Decision System Based on GIS

In order to reduce the loss of multimodal transport logistics , ensure the efficient, safe, realize the emergency state unified command, information sharing, coordination, rapid rescue, the study established the multimodal transport logistics emergency decision-making function modules, researched and developed application system of emergency decision based on GIS+GPS, and VC# technologies.The system is easy to use, compatibility, strong practicability, it can provide technical support and application value for multimodal logistics emergency rescue.

Failing to Establish a Unified Command in Louisiana During Hurricane Katrina

When Hurricane Katrina struck the United States in 2005, unified commands were established in several states under the principles of the Incident Command System (ICS). These unified commands helped to steer relief efforts. In Louisiana, however, a true unified command was never established, leaving mitigation efforts confused, chaotic, and ineffective. This article looks at the general concept of an ICS unified command; the attempt to establish a unified command in Louisiana; and reasons that the command never materialized.

A Study on Emergency Supply Chain and Risk Based on Urgent Relief Service in Disasters

In order to make the affected areas receive urgent relief service timely and accurately after the disasters, the effective operation of emergency logistics and quick response to the urgent demands in the affected areas is very critical. In this paper, firstly, the emergency supply chain management in disasters is presented, and the risk of disasters and urgent relief decision-making are analyzed, then the support mechanism of emergency logistics including infrastructure support, unified command and network coordination, law guarantee, contingency plan and emergency transportation channel is analyzed. Secondly, the evaluating indicators are specified by introducing the salvable degree concept, the salvable degrees of the affected areas which lie on the impact degrees of relief demands in the corresponding affected areas are analyzed and evaluated by the extension technique, and then a two-objective optimization model with the urgent relief demand time-varying fill rate maximization and the urgent relief distribution time-varying window minimization is developed in order to distribute urgent relief to the identified affected area sets. Finally, a numerical example demonstrates our conclusions.

Tulsa Oklahoma Oktoberfest Tent Collapse Report

Background. On October 17, 2007, a severe weather event collapsed two large tents and several smaller tents causing 23 injuries requiring evacuation to emergency departments in Tulsa, OK. Methods. This paper is a retrospective analysis of the regional health system's response to this event. Data from the Tulsa Fire Department, The Emergency Medical Services Authority (EMSA), receiving hospitals and coordinating services were reviewed and analyzed. EMS patient care reports were reviewed and analyzed using triage designators assigned in the field, injury severity scores, and critical mortality. Results. EMT's and paramedics from Tulsa Fire Department and EMSA provided care at the scene under unified incident command. Of the 23 patients transported by EMS, four were hospitalized, one with critical spinal injury and one with critical head injury. One patient is still in ongoing rehabilitation. Discussion. Analysis of the 2007 Tulsa Oktoberfest mass casualty incident revealed rapid police/fire/EMS response despite challenges of operations at dark under severe weather conditions and the need to treat a significant number of injured victims. There were no fatalities. Of the patients transported by EMS, a minority sustained critical injuries, with most sustaining injuries amenable to discharge after emergency department care.

Research on Urban Public Safety Emergency Management Early Warning System based on Technologies for the Internet of Things

Abstract Urban public safety emergency management early warning system based on technologies for the Internet of Things(IOT) can realize the function of omni-directional monitoring and control, accurate prediction and efficient disposal. The rescue mechanism of a unified command, complete function and response sensitivity, and operate efficient be formed by the system. And improve the city's ability to withstand to public emergencies have great significance. In this paper, the current research situation for Internet of Things application in the field of public safety is introduced. The characteristic,structure and constitution are expatiated in details with illustration. Then the software and hardware platform,and the system function are analyzed. The key technologies and the technical research routes of the system are expounded.

Strengthening Relations or Securing Resources? AFRICOM and US Military Interest in Africa

The September 11, 2001 attacks on American soil set into motion a new heightened level of international scrutiny and action. In response to the supposed foreign attacks, President G.W. Bush announced his plan for a War on Terrorism. Amidst the implementation of various anti-terrorist inspired mechanisms such as the creation of the US Department of Homeland Security, the Patriot Act, and a color-coded threat level chart, the Bush administration also refocused its aims on radical activity in Africa. Citing failed states on the continent as a national security hazard due to their alleged terrorist recruiting and harboring activities, in 2007 the Pentagon announced the creation of the United States Africa Command (AFRICOM) in order to defend the region from terrorist influences. AFRICOM is a unified command agency, which centralizes and regulates all US military relations throughout the continent of Africa.The official mission statement of AFRICOM declares the function of the organization to be for the US Department of Defense to coordinate, assist, and bolster the anti-terrorism efforts of sovereign African nations. It reads: Unlike traditional Unified Commands, Africa Command will focus on war prevention rather than war-fighting. Africa Command intends to work with African nations and African organizations to build regional security and crisis-response capacity in support of U.S. government efforts in Africa.Despite the rhetoric of cooperation and non-military intervention, the establishment of AFRICOM has raised the eyebrows of many critics. Some assert that the true interests of the United States in Africa are not those that are reflective of African unity or prosperity. Critics vocalize accusations that the United States is utilizing their War on Terrorism as a guise under which they can secure a military foothold in geo-strategic points throughout the African continent; many of which points have significant deposits of highly sought after natural resources. Fears of a neo-colonial resurgence that would threaten the sovereignty of African nations also surround the controversy over AFRICOM. What could be the long-term effects of a renewed US military force in Africa? What implications could this force have on the foreign policies of some African nations? Will the creation of AFRICOM bring security and political tranquility to unstable African governments? These are but a few of the question that will be tackled in this paper. This essay seeks to examine and critique the role of AFRICOM in US-African relations and to explore the possible benefits and detriments the establishment presents to African countries. The methodology utilized for this study consists primarily of document analysis of scholarly materials (journal articles, editorials, books, policy statements, etc.). Africa’s growing geo-strategic significance has put the continent back on the radars of world powers. Therefore, in order to comprehensively access Africa’s future, one must investigate the motives and aims of international players in Africa.