Richard Howard | University of Nottingham (original) (raw)
Papers by Richard Howard
This paper attempts to elucidate possible relationships between three multifaceted constructs: ps... more This paper attempts to elucidate possible relationships between three multifaceted constructs: psychopathy, impulsiveness and violence. A recently developed and validated quadripartite violence typology is described which parses violence into two motivationally distinct types according to whether it is appetitively or aversively driven. Nested within each type are 2 sub-types which depend on whether the violence is impulsive or premeditated/controlled. An attempt is then made to link each type and subtype of violence with, firstly, psychopathy as viewed through the prism of the Triarchic Psychopathy Model (TPM) which parses psychopathy into the three phenotypic components of Meanness, Boldness and Disinhibition; and secondly, impulsiveness parsed using the UPPS model into Urgency, (lack of) Perseverance, (lack of) Premeditation, and Sensation seeking. It is suggested that violence that is appetitively driven and controlled/premeditated (motivated by a desire for self-gratification) is related to Boldness; that violence that is appetitively driven and impulsive (motivated by a desire for excitement) is related to the combination of Boldness and Meanness; and that violence that is aversively driven and impulsive (motivated by a desire to protect oneself from a perceived and immediate threat) is related to the combination of Meanness and Disinhibition. It remains unclear whether, or how, the fourth violence type motivated by a desire for vengeance relates to the triarchic psychopathy components. While the suggested relationships are hypothetical, they provide a platform for empirical verification in future studies.
Ten years ago the author advanced a novel hypothesis that proposed a causal link between childho... more Ten years ago the author advanced a novel hypothesis that proposed a causal link between childhood conduct disorder (CD) and early alcohol abuse in the genesis of adult antisocial behavior. In the context of antecedent CD, progressive and accelerating use of alcoholand other drugs in adolescence was said to result in increasing disinhibition and progressive misuse of alcohol. Exposure of the vulnerable adolescent brain to excessive amounts of alcohol and other substances putatively results in structural and functional changes in the brain, particularly in those areas involved in emotional self- regulation. As a consequence, such individuals emerge into adulthood as emotionally impulsive and at high risk of serious antisocial conduct.
Evidence is here reviewed that supports several propositions. arising from this hypothesis: 1. The transition from childhood conduct disorder (CD) to adult antisocial behavior is mediated and moderated by early alcohol abuse. 2. Emotional impulsiveness is a core feature of severe personality disorder. 3. Severe personality disorder and emotional impulsiveness are associated with severe criminal violence. 4. Reoffending in patients with personality disorders is associated with severe drug and alcohol abuse, adult antisocial personality with severe CD, and severe borderline personality disorder. 5. Emotional impulsiveness as seen in severe personality disorder commonly manifests in anger. 6. An emotionally impulsive brain can be trained to be less impulsive.
Laser Radar Technology and Applications IV, 1999
ABSTRACT The Video Guidance Sensor is a key component of NASA's Automated Rendezvous &... more ABSTRACT The Video Guidance Sensor is a key component of NASA's Automated Rendezvous & Capture Program. The Video Guidance Sensor Uses laser illumination of a passive target in the field of view of an on-board camera and signal processor to determine the relative position and attitude between the target and sensor. The Video Guidance Sensor flew on space shuttle mission STS-95 in November of 1998 and was a marked success. Comparisons of experimental results from that mission and theoretical models predicting the optical performance will be discussed.
Laser Radar Technology and Applications III, 1998
ABSTRACT NASA's Marshall Space Flight Center flew on the STS-87 mission an active sensor ... more ABSTRACT NASA's Marshall Space Flight Center flew on the STS-87 mission an active sensor system, the Video Guidance Sensor (VGS), to demonstrate its functioning in space and to collect performance data. The VGS was designed to provide near-range sensor data as part of an automatic rendezvous and docking system. The sensor determines the relative positions and attitudes between the active sensor and the passive target. The VGS uses laser diodes to illuminate retro-reflectors in the target, a solid-state camera to detect the return from the target, and a frame grabber and digital signal processor to convert the video information into the relative positions and attitudes. The system is designed to operate with the target within a relative azimuth of +/- 9.5 degrees and a relative elevation of +/- 7.5 degrees. The system will acquire and track the target within that field-of-view anywhere from 1.5 meters to 110 meters range, and is designed to acquire at relative attitudes of +/- 10 degrees in pitch and yaw and at any roll angle. The data is output from the sensor at 5 Hz, and the target and sensor software have been designed to permit two independent sensors to operate simultaneously (in order to allow for redundancy). The data from the flight experiment includes raw video data from the VGS camera, relative position and attitude measurements from the VGS to the target, independent hand-held laser ranges from the Shuttle Aft Flight Deck to the target, and Remote Manipulator System position data to correlate with the VGS data. The experiment was quite successful and returned much useful information. The experience gained from the design and flight of this experiment will lead to improved video sensors in the future.
Laser Radar Technology and Applications III, 1998
ABSTRACT The Video Guidance Sensor was flown on STS-87 in November of 1997 and is the key element... more ABSTRACT The Video Guidance Sensor was flown on STS-87 in November of 1997 and is the key element of an automatic rendezvous and docking program under development by NASA Marshall Space Flight Center. The system used laser illumination of a passive target in the field of view of an on-board camera and processed the video image to determine the relative position and attitude between the target and the sensor. Comparisons of mission results with theoretical models are discussed.
Transplantation proceedings, 2006
The aim of the current study was to clarify whether recurrence of hepatitis C (HCV) infection aff... more The aim of the current study was to clarify whether recurrence of hepatitis C (HCV) infection affects biliary complications after liver transplantation (OLT), with special reference to late biliary anastomotic strictures (LBAS). We reviewed 665 consecutive adult OLT recipients with a choledochocholedochostomy without T-tube placement between 1990 and 2005. Biliary anastomotic stricture was confirmed by ERCP. The LBAS was defined as stricture that occurred 30 days or more after OLT. Recurrence of HCV was diagnosed by histological examination using liver biopsy specimen and confirmed by the presence of HCV-RNA. Early HCV recurrence was defined as recurrence that occurred within 6 months after OLT; LBAS occurred in 54 patients (8% of total). Mean duration from OLT to occurrence of LBAS was 6.9 months (1-44 months). Patients with HCV infection had higher occurrence of LBAS than did non-HCV patients (11% vs 5%, P = .0093). Among HCV patients, those with early HCV recurrence had exclusive...
Transplantation, Jan 15, 2007
Liver transplantation (LT) from controlled donation after cardiac death (DCD) donors has increase... more Liver transplantation (LT) from controlled donation after cardiac death (DCD) donors has increased steadily during the past decade because of the donor shortage in the United States. Although early reports of LT from DCD donors provided evidence for acceptable outcomes, long-term graft and patient survival rates from these procedures have been reviewed only recently. From February 1990 to June 2006, 1209 LTs were performed from donation after brain death (DBD) donors, and 24 were performed from DCD donors at our institution. Detailed review of donor and recipient characteristics, and survival rates were evaluated in the two groups. One- and 3-year patient survival was similar in both groups, (DCD 86.8%, 81.7% vs. DBD 84.0%, 76.0%, respectively; P=0.713). Graft survival appeared inferior in the DCD group compared with the DBD group at 1 year (69.1% vs. 78.7%) and 3 years (58.6% vs. 70.2%), but there was no statistical difference (P=0.082). There were no significant differences in hep...
Progress in transplantation (Aliso Viejo, Calif.), 2008
Signed donor cards clearly demonstrate the donor's intention to donate organs after death. In... more Signed donor cards clearly demonstrate the donor's intention to donate organs after death. In many states, this donation cannot be rescinded by the next of kin, and organs can be recovered from the donor even if the family objects. The family usually does not object if the donor has signed an organ donor card, especially if the donor had discussed the issue with the family. In some situations, however, the family objects to donation despite the signed organ donor card. If the organ procurement organization pursues donation, adverse publicity and even legal action are possible. It can be a challenge for organ procurement personnel to deal with families who object to donation in the face of a signed organ donor card in a manner that will lead to successful organ recovery without adverse consequences. This article describes 4 cases where the donor had a signed organ donor card but the family initially objected to donation. Ultimately organs were recovered from 3 of these donors.
Transplantation, 2002
The results of kidney transplantation have improved markedly over the last three decades. Despite... more The results of kidney transplantation have improved markedly over the last three decades. Despite this, patients still lose grafts and die. We sought to determine whether the causes of graft loss and death have changed over the last 30 years. We reviewed patients who underwent transplantation or who died between January 1, 1970 and December 31, 1999. We compared the causes of graft loss or death for three decades: 1970 to 1979, 1980 to 1989, and 1990 to 1999. From January 1, 1970 to December 31, 1999, we performed 2501 kidney transplantations in 2225 patients. For the three periods, 210, 588, and 383 patients lost their grafts, respectively. Graft survival increased substantially. Graft loss occurred later after transplantation, with 36.0% losing grafts in the first year during 1970 to 1970, 22.8% during 1980 to 1989, and 11.4% during 1990 to 1999. Death with a functioning graft increased from 23.8% for 1970 to 1979 to 37.5% for 1990 to 1999. Concomitantly, rejection as a cause of graft loss fell from 65.7% for 1970 to 1979 to 44.6% for 1990 to 1999. Approximately two thirds of the patients who died after transplantation died with a functioning graft and one third died after returning to dialysis. Cardiac disease as a cause of death increased from 9.6% for 1970 to 1979 to 30.3% for 1990 to 1999. Deaths from cancer and stroke also increased significantly over the three decades from 1.2% and 2.4%, respectively, for 1970 to 1979, to 13.2% and 8.0%, respectively, for 1990 to 1999. The causes of graft loss and death have changed over the last three decades. By better addressing the main causes of death, cardiac disease, and stroke with better prevention, graft loss due to death with a functioning graft will be reduced.
2008 IEEE Aerospace Conference, 2008
The exploration systems architecture defines missions that require rendezvous, proximity operatio... more The exploration systems architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in low earth orbit (LEO) and in low lunar orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&amp;amp;amp;amp;amp;amp;amp;amp;amp;D). The crewed missions may also perform rendezvous and docking operations and may require different
2008 IEEE Aerospace Conference, 2008
ABSTRACT In May 2007 the first US-sponsored fully autonomous rendezvous and capture was successfu... more ABSTRACT In May 2007 the first US-sponsored fully autonomous rendezvous and capture was successfully performed by DARPA's Orbital Express (OE) mission. For the following three months, the Boeing ASTRO spacecraft and the Ball Aerospace NEXTSat performed multiple rendezvous and docking maneuvers to demonstrate some of the technologies needed for satellite servicing. MSFC's advanced video guidance sensor (AVGS) was a near-field proximity operations sensor integrated into ASTRO's Autonomous Rendezvous and Capture Sensor System (ARCSS), which provided relative state knowledge to the ASTRO GN&C system. AVGS was one of the primary docking sensors included in ARCSS. This paper provides an overview of the AVGS sensor that flew on orbital express, a summary of the AVGS ground testing, and a discussion of AVGS performance on-orbit for OE. The AVGS is a laser-based system that is capable of providing bearing at midrange distances and full six degree- of-freedom (6-DOF) knowledge at near ranges. The sensor fires lasers of two different wavelengths to illuminate retro- reflectors on the long range target (LRT) and the Short Range Target (SRT) mounted on NEXTSat. The retro- reflector filters allow one laser wavelength to pass through and be reflected, while blocking the other wavelength. Subtraction of one return image from the other image removes extraneous light sources and reflections from anything other than the corner cubes on the LRT and SRT. The very bright spots that remain in the subtracted image are processed to provide bearing or 6-DOF relative state information. AVGS was operational during the Orbital Express unmated scenarios and the sensor checkout operations. The OE unmated scenarios ranged from 10 meters to 7 kilometers ending in either a docking or a free-flyer capture. When the target was pointed toward the AVGS and in the AVGS operating range and field-of-view (i.e. along the approach corridor of the NEXTSat), the AVGS provided full 6-DOF measurements. The AVGS p- erformed very well during the sensor check-out operations, effectively tracking beyond its 10-degree Pitch and Yaw limit-specifications. AVGS also provided excellent performance during the unmated operations, effectively tracking its targets, and showing good agreement between the SRT and LRT data. The AVGS consistently exceeded the tracking range expectations for both the SRT and LRT. During the approach to re-mate in scenario 3-1 recovery the AVGS began tracking the LRT at 150 m, well beyond the OE specified operational range of 120 meters, and functioned as the primary sensor for the autonomous rendezvous and docking. For all scenarios, the AVGS was used while ASTRO was in the approach corridor to NEXTSat, and during close proximity operations and docking.
Advanced Telescope and Instrumentation Control Software II, 2002
The software development for an upgrade to the Hobby-Eberly Telescope (HET) was done in LabVIEW. ... more The software development for an upgrade to the Hobby-Eberly Telescope (HET) was done in LabVIEW. In order to improve the performance of the HET at the McDonald Observatory, a closed-loop system had to be implemented to keep the mirror segments aligned during periods of observation. The control system, called the Segment Alignment Maintenance System (SAMS), utilized inductive sensors to measure
Prenatal Diagnosis, 1992
Over a period of 25 months, all antenatal patients were offered a detailed ultrasound scan at 18-... more Over a period of 25 months, all antenatal patients were offered a detailed ultrasound scan at 18-20 weeks&amp;#39; gestation. The lateral cerebral ventricles were scanned for the presence of choroid plexus cysts. Fifty-one patients found to have choroid plexus cysts were offered amniocentesis to exclude chromosomal abnormalities. One pregnancy, in which the only abnormality found was bilateral choroid plexus cysts, was terminated after trisomy 18 was detected on amniocentesis at 19 weeks. The other 50 pregnancies had normal fetal outcomes. The significance of the isolated finding of choroid plexus cysts is reviewed.
British Medical Journal, 1993
Sickle cell disease is listed in the manufacturers' data sheets in the United Kingdom as a co... more Sickle cell disease is listed in the manufacturers' data sheets in the United Kingdom as a contraindication to the use of most combined contraceptive pills; the result is confused advice on family planning to a group of women who are at substantial risk from both planned and unplanned pregnancy. A study in north London on the use of contraceptives by
Laser Radar Technology and Applications IV, 1999
ABSTRACT The Video Guidance Sensor (VGS), part of NASA's Automated Rendezvous and Capture... more ABSTRACT The Video Guidance Sensor (VGS), part of NASA's Automated Rendezvous and Capture program, was flown on Shuttle mission STS-95 in October of 1998 to orbitally test the functional characteristics of the VGS. This was the second flight of the VGS (the first flight was in 1997 on STS-87), and this time long-range tracking data was gathered during the experiment. The flight experiment sensor was designed to operate from 1.5 meter range out to 110 meter range, with a field-of-view of 16 X 21 degrees. The VGS tracked its target at a 5 Hz rate and returned 6-degree-of-freedom information on the target's position and attitude relative to the sensor. The VGS was mounted in the Shuttle cargo bay, and its target was mounted on the Spartan spacecraft being carried on this mission. The orbital testing of the VGS included operations with the target on the Shuttle's Remote Manipulator System (RMS) at the start of the 10-day mission, long-range data during the Shuttle rendezvous with the Spartan two days later, and some more RMS operations later in the mission. The data returned from the orbital testing included VGS diagnostics, acquisition, and tracking data, RMS positions, hand-held laser range data, tapes of the data from the VGS video camera, and orbital positioning data from the Spartan and the Shuttle to allow correlation of the VGS data with orbital best-estimate-of-truth data. The Video Guidance Sensor performed well in all phases of the testing, and the VGS is being incorporated into the ground testing of a complete automated rendezvous and docking system. Work on the development of the next generation VGS is continuing
Laser Radar Technology and Applications II, 1997
ABSTRACT The video guidance sensor is a key element of an automatic rendezvous and docking progra... more ABSTRACT The video guidance sensor is a key element of an automatic rendezvous and docking program administered by NASA. The system sues laser illumination of passive target in the field of view of an on-board camera and processes the video image to determine the relative position and attitude between the target and the sensor. Theoretical predictions and evaluations, and laboratory measurements and test are presented for the lasers, target components, camera system, signal processor, and a solar simulator. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints
This paper attempts to elucidate possible relationships between three multifaceted constructs: ps... more This paper attempts to elucidate possible relationships between three multifaceted constructs: psychopathy, impulsiveness and violence. A recently developed and validated quadripartite violence typology is described which parses violence into two motivationally distinct types according to whether it is appetitively or aversively driven. Nested within each type are 2 sub-types which depend on whether the violence is impulsive or premeditated/controlled. An attempt is then made to link each type and subtype of violence with, firstly, psychopathy as viewed through the prism of the Triarchic Psychopathy Model (TPM) which parses psychopathy into the three phenotypic components of Meanness, Boldness and Disinhibition; and secondly, impulsiveness parsed using the UPPS model into Urgency, (lack of) Perseverance, (lack of) Premeditation, and Sensation seeking. It is suggested that violence that is appetitively driven and controlled/premeditated (motivated by a desire for self-gratification) is related to Boldness; that violence that is appetitively driven and impulsive (motivated by a desire for excitement) is related to the combination of Boldness and Meanness; and that violence that is aversively driven and impulsive (motivated by a desire to protect oneself from a perceived and immediate threat) is related to the combination of Meanness and Disinhibition. It remains unclear whether, or how, the fourth violence type motivated by a desire for vengeance relates to the triarchic psychopathy components. While the suggested relationships are hypothetical, they provide a platform for empirical verification in future studies.
Ten years ago the author advanced a novel hypothesis that proposed a causal link between childho... more Ten years ago the author advanced a novel hypothesis that proposed a causal link between childhood conduct disorder (CD) and early alcohol abuse in the genesis of adult antisocial behavior. In the context of antecedent CD, progressive and accelerating use of alcoholand other drugs in adolescence was said to result in increasing disinhibition and progressive misuse of alcohol. Exposure of the vulnerable adolescent brain to excessive amounts of alcohol and other substances putatively results in structural and functional changes in the brain, particularly in those areas involved in emotional self- regulation. As a consequence, such individuals emerge into adulthood as emotionally impulsive and at high risk of serious antisocial conduct.
Evidence is here reviewed that supports several propositions. arising from this hypothesis: 1. The transition from childhood conduct disorder (CD) to adult antisocial behavior is mediated and moderated by early alcohol abuse. 2. Emotional impulsiveness is a core feature of severe personality disorder. 3. Severe personality disorder and emotional impulsiveness are associated with severe criminal violence. 4. Reoffending in patients with personality disorders is associated with severe drug and alcohol abuse, adult antisocial personality with severe CD, and severe borderline personality disorder. 5. Emotional impulsiveness as seen in severe personality disorder commonly manifests in anger. 6. An emotionally impulsive brain can be trained to be less impulsive.
Laser Radar Technology and Applications IV, 1999
ABSTRACT The Video Guidance Sensor is a key component of NASA's Automated Rendezvous &... more ABSTRACT The Video Guidance Sensor is a key component of NASA's Automated Rendezvous & Capture Program. The Video Guidance Sensor Uses laser illumination of a passive target in the field of view of an on-board camera and signal processor to determine the relative position and attitude between the target and sensor. The Video Guidance Sensor flew on space shuttle mission STS-95 in November of 1998 and was a marked success. Comparisons of experimental results from that mission and theoretical models predicting the optical performance will be discussed.
Laser Radar Technology and Applications III, 1998
ABSTRACT NASA's Marshall Space Flight Center flew on the STS-87 mission an active sensor ... more ABSTRACT NASA's Marshall Space Flight Center flew on the STS-87 mission an active sensor system, the Video Guidance Sensor (VGS), to demonstrate its functioning in space and to collect performance data. The VGS was designed to provide near-range sensor data as part of an automatic rendezvous and docking system. The sensor determines the relative positions and attitudes between the active sensor and the passive target. The VGS uses laser diodes to illuminate retro-reflectors in the target, a solid-state camera to detect the return from the target, and a frame grabber and digital signal processor to convert the video information into the relative positions and attitudes. The system is designed to operate with the target within a relative azimuth of +/- 9.5 degrees and a relative elevation of +/- 7.5 degrees. The system will acquire and track the target within that field-of-view anywhere from 1.5 meters to 110 meters range, and is designed to acquire at relative attitudes of +/- 10 degrees in pitch and yaw and at any roll angle. The data is output from the sensor at 5 Hz, and the target and sensor software have been designed to permit two independent sensors to operate simultaneously (in order to allow for redundancy). The data from the flight experiment includes raw video data from the VGS camera, relative position and attitude measurements from the VGS to the target, independent hand-held laser ranges from the Shuttle Aft Flight Deck to the target, and Remote Manipulator System position data to correlate with the VGS data. The experiment was quite successful and returned much useful information. The experience gained from the design and flight of this experiment will lead to improved video sensors in the future.
Laser Radar Technology and Applications III, 1998
ABSTRACT The Video Guidance Sensor was flown on STS-87 in November of 1997 and is the key element... more ABSTRACT The Video Guidance Sensor was flown on STS-87 in November of 1997 and is the key element of an automatic rendezvous and docking program under development by NASA Marshall Space Flight Center. The system used laser illumination of a passive target in the field of view of an on-board camera and processed the video image to determine the relative position and attitude between the target and the sensor. Comparisons of mission results with theoretical models are discussed.
Transplantation proceedings, 2006
The aim of the current study was to clarify whether recurrence of hepatitis C (HCV) infection aff... more The aim of the current study was to clarify whether recurrence of hepatitis C (HCV) infection affects biliary complications after liver transplantation (OLT), with special reference to late biliary anastomotic strictures (LBAS). We reviewed 665 consecutive adult OLT recipients with a choledochocholedochostomy without T-tube placement between 1990 and 2005. Biliary anastomotic stricture was confirmed by ERCP. The LBAS was defined as stricture that occurred 30 days or more after OLT. Recurrence of HCV was diagnosed by histological examination using liver biopsy specimen and confirmed by the presence of HCV-RNA. Early HCV recurrence was defined as recurrence that occurred within 6 months after OLT; LBAS occurred in 54 patients (8% of total). Mean duration from OLT to occurrence of LBAS was 6.9 months (1-44 months). Patients with HCV infection had higher occurrence of LBAS than did non-HCV patients (11% vs 5%, P = .0093). Among HCV patients, those with early HCV recurrence had exclusive...
Transplantation, Jan 15, 2007
Liver transplantation (LT) from controlled donation after cardiac death (DCD) donors has increase... more Liver transplantation (LT) from controlled donation after cardiac death (DCD) donors has increased steadily during the past decade because of the donor shortage in the United States. Although early reports of LT from DCD donors provided evidence for acceptable outcomes, long-term graft and patient survival rates from these procedures have been reviewed only recently. From February 1990 to June 2006, 1209 LTs were performed from donation after brain death (DBD) donors, and 24 were performed from DCD donors at our institution. Detailed review of donor and recipient characteristics, and survival rates were evaluated in the two groups. One- and 3-year patient survival was similar in both groups, (DCD 86.8%, 81.7% vs. DBD 84.0%, 76.0%, respectively; P=0.713). Graft survival appeared inferior in the DCD group compared with the DBD group at 1 year (69.1% vs. 78.7%) and 3 years (58.6% vs. 70.2%), but there was no statistical difference (P=0.082). There were no significant differences in hep...
Progress in transplantation (Aliso Viejo, Calif.), 2008
Signed donor cards clearly demonstrate the donor's intention to donate organs after death. In... more Signed donor cards clearly demonstrate the donor's intention to donate organs after death. In many states, this donation cannot be rescinded by the next of kin, and organs can be recovered from the donor even if the family objects. The family usually does not object if the donor has signed an organ donor card, especially if the donor had discussed the issue with the family. In some situations, however, the family objects to donation despite the signed organ donor card. If the organ procurement organization pursues donation, adverse publicity and even legal action are possible. It can be a challenge for organ procurement personnel to deal with families who object to donation in the face of a signed organ donor card in a manner that will lead to successful organ recovery without adverse consequences. This article describes 4 cases where the donor had a signed organ donor card but the family initially objected to donation. Ultimately organs were recovered from 3 of these donors.
Transplantation, 2002
The results of kidney transplantation have improved markedly over the last three decades. Despite... more The results of kidney transplantation have improved markedly over the last three decades. Despite this, patients still lose grafts and die. We sought to determine whether the causes of graft loss and death have changed over the last 30 years. We reviewed patients who underwent transplantation or who died between January 1, 1970 and December 31, 1999. We compared the causes of graft loss or death for three decades: 1970 to 1979, 1980 to 1989, and 1990 to 1999. From January 1, 1970 to December 31, 1999, we performed 2501 kidney transplantations in 2225 patients. For the three periods, 210, 588, and 383 patients lost their grafts, respectively. Graft survival increased substantially. Graft loss occurred later after transplantation, with 36.0% losing grafts in the first year during 1970 to 1970, 22.8% during 1980 to 1989, and 11.4% during 1990 to 1999. Death with a functioning graft increased from 23.8% for 1970 to 1979 to 37.5% for 1990 to 1999. Concomitantly, rejection as a cause of graft loss fell from 65.7% for 1970 to 1979 to 44.6% for 1990 to 1999. Approximately two thirds of the patients who died after transplantation died with a functioning graft and one third died after returning to dialysis. Cardiac disease as a cause of death increased from 9.6% for 1970 to 1979 to 30.3% for 1990 to 1999. Deaths from cancer and stroke also increased significantly over the three decades from 1.2% and 2.4%, respectively, for 1970 to 1979, to 13.2% and 8.0%, respectively, for 1990 to 1999. The causes of graft loss and death have changed over the last three decades. By better addressing the main causes of death, cardiac disease, and stroke with better prevention, graft loss due to death with a functioning graft will be reduced.
2008 IEEE Aerospace Conference, 2008
The exploration systems architecture defines missions that require rendezvous, proximity operatio... more The exploration systems architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in low earth orbit (LEO) and in low lunar orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&amp;amp;amp;amp;amp;amp;amp;amp;amp;D). The crewed missions may also perform rendezvous and docking operations and may require different
2008 IEEE Aerospace Conference, 2008
ABSTRACT In May 2007 the first US-sponsored fully autonomous rendezvous and capture was successfu... more ABSTRACT In May 2007 the first US-sponsored fully autonomous rendezvous and capture was successfully performed by DARPA's Orbital Express (OE) mission. For the following three months, the Boeing ASTRO spacecraft and the Ball Aerospace NEXTSat performed multiple rendezvous and docking maneuvers to demonstrate some of the technologies needed for satellite servicing. MSFC's advanced video guidance sensor (AVGS) was a near-field proximity operations sensor integrated into ASTRO's Autonomous Rendezvous and Capture Sensor System (ARCSS), which provided relative state knowledge to the ASTRO GN&C system. AVGS was one of the primary docking sensors included in ARCSS. This paper provides an overview of the AVGS sensor that flew on orbital express, a summary of the AVGS ground testing, and a discussion of AVGS performance on-orbit for OE. The AVGS is a laser-based system that is capable of providing bearing at midrange distances and full six degree- of-freedom (6-DOF) knowledge at near ranges. The sensor fires lasers of two different wavelengths to illuminate retro- reflectors on the long range target (LRT) and the Short Range Target (SRT) mounted on NEXTSat. The retro- reflector filters allow one laser wavelength to pass through and be reflected, while blocking the other wavelength. Subtraction of one return image from the other image removes extraneous light sources and reflections from anything other than the corner cubes on the LRT and SRT. The very bright spots that remain in the subtracted image are processed to provide bearing or 6-DOF relative state information. AVGS was operational during the Orbital Express unmated scenarios and the sensor checkout operations. The OE unmated scenarios ranged from 10 meters to 7 kilometers ending in either a docking or a free-flyer capture. When the target was pointed toward the AVGS and in the AVGS operating range and field-of-view (i.e. along the approach corridor of the NEXTSat), the AVGS provided full 6-DOF measurements. The AVGS p- erformed very well during the sensor check-out operations, effectively tracking beyond its 10-degree Pitch and Yaw limit-specifications. AVGS also provided excellent performance during the unmated operations, effectively tracking its targets, and showing good agreement between the SRT and LRT data. The AVGS consistently exceeded the tracking range expectations for both the SRT and LRT. During the approach to re-mate in scenario 3-1 recovery the AVGS began tracking the LRT at 150 m, well beyond the OE specified operational range of 120 meters, and functioned as the primary sensor for the autonomous rendezvous and docking. For all scenarios, the AVGS was used while ASTRO was in the approach corridor to NEXTSat, and during close proximity operations and docking.
Advanced Telescope and Instrumentation Control Software II, 2002
The software development for an upgrade to the Hobby-Eberly Telescope (HET) was done in LabVIEW. ... more The software development for an upgrade to the Hobby-Eberly Telescope (HET) was done in LabVIEW. In order to improve the performance of the HET at the McDonald Observatory, a closed-loop system had to be implemented to keep the mirror segments aligned during periods of observation. The control system, called the Segment Alignment Maintenance System (SAMS), utilized inductive sensors to measure
Prenatal Diagnosis, 1992
Over a period of 25 months, all antenatal patients were offered a detailed ultrasound scan at 18-... more Over a period of 25 months, all antenatal patients were offered a detailed ultrasound scan at 18-20 weeks&amp;#39; gestation. The lateral cerebral ventricles were scanned for the presence of choroid plexus cysts. Fifty-one patients found to have choroid plexus cysts were offered amniocentesis to exclude chromosomal abnormalities. One pregnancy, in which the only abnormality found was bilateral choroid plexus cysts, was terminated after trisomy 18 was detected on amniocentesis at 19 weeks. The other 50 pregnancies had normal fetal outcomes. The significance of the isolated finding of choroid plexus cysts is reviewed.
British Medical Journal, 1993
Sickle cell disease is listed in the manufacturers' data sheets in the United Kingdom as a co... more Sickle cell disease is listed in the manufacturers' data sheets in the United Kingdom as a contraindication to the use of most combined contraceptive pills; the result is confused advice on family planning to a group of women who are at substantial risk from both planned and unplanned pregnancy. A study in north London on the use of contraceptives by
Laser Radar Technology and Applications IV, 1999
ABSTRACT The Video Guidance Sensor (VGS), part of NASA's Automated Rendezvous and Capture... more ABSTRACT The Video Guidance Sensor (VGS), part of NASA's Automated Rendezvous and Capture program, was flown on Shuttle mission STS-95 in October of 1998 to orbitally test the functional characteristics of the VGS. This was the second flight of the VGS (the first flight was in 1997 on STS-87), and this time long-range tracking data was gathered during the experiment. The flight experiment sensor was designed to operate from 1.5 meter range out to 110 meter range, with a field-of-view of 16 X 21 degrees. The VGS tracked its target at a 5 Hz rate and returned 6-degree-of-freedom information on the target's position and attitude relative to the sensor. The VGS was mounted in the Shuttle cargo bay, and its target was mounted on the Spartan spacecraft being carried on this mission. The orbital testing of the VGS included operations with the target on the Shuttle's Remote Manipulator System (RMS) at the start of the 10-day mission, long-range data during the Shuttle rendezvous with the Spartan two days later, and some more RMS operations later in the mission. The data returned from the orbital testing included VGS diagnostics, acquisition, and tracking data, RMS positions, hand-held laser range data, tapes of the data from the VGS video camera, and orbital positioning data from the Spartan and the Shuttle to allow correlation of the VGS data with orbital best-estimate-of-truth data. The Video Guidance Sensor performed well in all phases of the testing, and the VGS is being incorporated into the ground testing of a complete automated rendezvous and docking system. Work on the development of the next generation VGS is continuing
Laser Radar Technology and Applications II, 1997
ABSTRACT The video guidance sensor is a key element of an automatic rendezvous and docking progra... more ABSTRACT The video guidance sensor is a key element of an automatic rendezvous and docking program administered by NASA. The system sues laser illumination of passive target in the field of view of an on-board camera and processes the video image to determine the relative position and attitude between the target and the sensor. Theoretical predictions and evaluations, and laboratory measurements and test are presented for the lasers, target components, camera system, signal processor, and a solar simulator. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints